a 1 2 rearrangement or 1 2 migration or 1 2 shift or whitmore 1 2 shift is an organic reaction where a substituent moves from one atom to another atom in a chemical compound in a 1 2 shift the movement involves two adjacent atoms but moves over larger distances are possible in the example below the substituent r moves from carbon atom c 2 to c 3 1 2 shift the rearrangement is intramolecular and the starting compound and reaction product are structural isomers the 1 2 rearrangement belongs to a broad class of chemical reactions called rearrangement reactions a rearrangement involving a hydrogen atom is called a 1 2 hydride shift if the substituent being rearranged is an alkyl group it is named according to the alkyl group s anion i e 1 2 methanide shift 1 2 ethanide shift etc
the 1 3 dipolar cycloaddition is a chemical reaction between a 1 3 dipole and a dipolarophile to form a five membered ring the earliest 1 3 dipolar cycloadditions were described in the late 19 th century to the early 20 th century following the discovery of 1 3 dipoles mechanistic investigation and synthetic application were established in the 1960 s primarily through the work of rolf huisgen hence the reaction is sometimes referred to as the huisgen cycloaddition this term is often used to specifically describe the 1 3 dipolar cycloaddition between an organic azide and an alkyne to generate 1 2 3 triazole currently 1 3 dipolar cycloaddition is an important route to the regio and stereoselective synthesis of five membered heterocycles and their ring opened acyclic derivatives x
the 1 center problem or minimax or minmax location problem is a classical combinatorial optimization problem in operations research of facilities location type in its most general case the problem is stated as follows given a set of n demand points a space of feasible locations of a facility and a function to calculate the transportation cost between a facility and any demand point find a location of the facility which minimizes the maximum facility demand point transportation cost the simple special case when the feasible locations and demand points are in the plane with euclidean distance as transportation cost planar minmax euclidean facility location problem euclidean 1 center problem in the plane etc it is also known as the smallest circle problem its generalization to n dimensional euclidean spaces is known as the smallest enclosing ball problem a further generalization weighted euclidean facility location is when the set of weights is assigned to demand points and the transportation cost is the sum of the products of distances by the corresponding weights another special case the closest string problem arises when the inputs are strings and their distance is measured using hamming distance there are numerous particular cases of the problem depending on the choice of the locations both of demand points and facilities as well as the distance function
the 100 prisoners problem is a mathematical problem in probability theory and combinatorics in this problem 100 numbered prisoners to survive must find their own numbers in one of 100 drawers the rules state that each prisoner may open only 50 drawers and cannot communicate with other prisoners at first glance the situation appears hopeless — but a clever strategy offers the prisoners a realistic chance of survival danish computer scientist peter bro miltersen first proposed the problem in 2003
the 10 in 40 type 41 naval gun was a 40 calibre elswick ordnance company pattern r naval gun designed in the 1890 s for export it was sold to italy argentina and japan in small numbers
12 5 is pain of salvation s first live album it was released in 2004 and was recorded from a concert in the band s home town of eskilstuna sweden on 12 may 12 5 2003 it was an unplugged show meaning that there were only acoustic instruments i e no electric guitars grand piano and harpsichord instead of synthesizers it features songs from all the band s albums to that date except one hour by the concrete lake
13 q deletion syndrome is a rare genetic disease caused by the deletion of some or all of the large arm of human chromosome 13 it causes intellectual disability and congenital malformations that affect a variety of organ systems
17 β hydroxysteroid dehydrogenase iii deficiency is a rare disorder of sexual development affecting testosterone biosynthesis by 17 β hydroxysteroid dehydrogenase iii 17 β hsd iii which can produce impaired virilization traditionally termed male pseudohermaphroditism of genetically male infants and children and excessive virilization of female adults it is an autosomal recessive condition and is one of the few disorders of sexual development that can affect the primary and or secondary sex characteristics of both males and females
17 q 21 31 microdeletion syndrome koolen de vries syndrome is a rare genetic disorder caused by a deletion of a segment of chromosome 17 which contains six genes this deletion syndrome was discovered independently in 2006 by three different research groups
there is a drastic decline in the number of ships visiting new zealand from the previous year an economic depression starts in new south wales as a result of the escalation of war in europe and the consequent reduction in the number of convicts being transported in march news of the boyd massacre reaches port jackson and a punitive expedition is sent to new zealand and bombards the village of the incorrectly blamed chief te pahi after this the few whaling ships possibly only 5 that later head for new zealand usually prefer to avoid landing especially in the bay of islands sealing in foveaux strait declines as the rookeries are exhausted with the discovery of campbell island at the beginning of the year and macquarie island in the middle of the year by the same sealing ship sealers transfer their attention there if they stop off in new zealand it is usually in foveaux strait
the 1858 bradford sweets poisoning was the arsenic poisoning of more than 200 people in bradford england when sweets accidentally made with arsenic were sold from a market stall twenty one victims died as a result the event contributed to the passage of the pharmacy act 1868 in the united kingdom and legislation regulating the adulteration of foodstuffs
the fourth cholera pandemic of the 19 th century began in the ganges delta of the bengal region and traveled with muslim pilgrims to mecca in its first year the epidemic claimed 30 000 of 90 000 mecca pilgrims cholera spread throughout the middle east and was carried to russia europe africa and north america in each case spreading from port cities and along inland waterways the pandemic reached northern africa in 1865 and spread to sub saharan africa killing 70 000 in zanzibar in 1869 – 70 cholera claimed 90 000 lives in russia in 1866 the epidemic of cholera that spread with the austro prussian war 1866 is estimated to have taken 165 000 lives in the austrian empire including 30 000 each in hungary and belgium and 20 000 in the netherlands in london in june 1866 a localized epidemic in the east end claimed 5 596 lives just as the city was completing construction of its major sewage and water treatment systems see london sewerage system the east end section was not quite complete epidemiologist william farr identified the east london water company as the source of the contamination farr made use of prior work by john snow and others pointing to contaminated drinking water as the likely cause of cholera in an 1854 outbreak in the same year the use of contaminated canal water in local water works caused a minor outbreak at ystalyfera in south wales workers associated with the company and their families were most affected and 119 died in 1867 italy lost 113 000 lives and 80 000 died of the disease in algeria outbreaks in north america in the 1870 s killed some 50 000 americans as cholera spread from new orleans along the mississippi river and to ports on its tributaries
the 1888 eruption of mount bandai was a major volcanic eruption which occurred during the meiji period of the empire of japan the eruption occurred on july 15 1888 and pyroclastic flows buried villages on the northern foot of the mountain and devastated the eastern part of bandai region fukushima prefecture north of tokyo at least 477 people were killed and hundreds more were injured and rendered homeless in what became the worst volcanic disaster in recent japanese history the eruption had many similarities to the 1980 eruption of mount st helens in the united states
18 p is a genetic condition caused by a deletion of all or part of the short arm the p arm of chromosome 18 it occurs in about 1 of every 50 000 births
the 1904 pictorial 4 d lake taupo invert is a postage stamp error considered to be the rarest new zealand stamp the centre vignette is inverted in relation to the outer frame the stamp was discovered in a schoolboy album in 1930 and no other copy has been found since then the 4 d stamp depicts lake taupo in new zealand s north island it was part of the first pictorial series originally issued in 1898 but reissued in different colours and sizes in 1899 and 1900 the same design was used for a 1 d value issued in 1898 the sole example is used postmarked picton 1904
the 1924 los angeles pneumonic plague outbreak began october 30 1924 and was declared fully contained on november 13 1924 it represented the first time plague had emerged in southern california previously plague outbreaks had arisen in san francisco and nearby oakland marking the first time plague had emerged in california the los angeles outbreak began on october 30 lasted two weeks and killed 30 people public health officials credited the lessons learned from the san francisco outbreak coupled with swiftly implemented measures including hospitalization of the sick and all their contacts a neighborhood quarantine and a large scale rat eradication program with saving lives
the 1929 30 sm sarja season was cancelled cause of a bad winter in finland as there was no safe and good ice to play on as a result the entire season was cancelled
the 1941 1942 sm sarja season was cancelled cause of the continuation war
the luxembourgish general strike of 1942 was a manifestation of passive resistance when luxembourg was occupied by nazi germany during world war ii the strikes opposed a directive that conscripted young luxembourgers into the wehrmacht a nationwide general strike originating in wiltz paralysed the country and led to the occupying german authorities responding violently by sentencing 21 strikers to death
the 1943 1944 sm sarja season was stopped mid season cause of the continuation war this would be the last sm sarja sm liiga season which had to be cancelled pre or mid season
the 1951 pont saint esprit mass poisoning also known as le pain maudit was a mass poisoning on 15 august 1951 in the small town of pont saint esprit in southern france more than 250 people were involved including 50 persons interned in asylums and 7 deaths a foodborne illness was suspected and among these it was originally believed to be a case of cursed bread pain maudit most academic sources accept ergot poisoning as the cause of the epidemic while a few theorize other causes such as poisoning by mercury mycotoxins or nitrogen trichloride fringe theorists have speculated that the united states central intelligence agency cia intentionally poisoned the population in order to test a deliriant incapacitating agent during the cold war
the 1951 usaf resolution test chart is a resolution test pattern conforming to mil std 150 a standard set by us air force in 1951 it is still widely accepted to test the resolution of optical imaging systems such as microscopes cameras and image scanners although mil std 150 a was cancelled on october 16 2006 the pattern consists of groups of three bars small ronchi rulings with dimensions from big to small the largest bar the imager cannot discern is the limitation of its resolving power
the 1952 commonwealth prime ministers economic conference was an emergency meeting of the heads of government of the commonwealth of nations it was called by the british government of sir winston churchill and held in the united kingdom in december 1952 as a follow up to a commonwealth finance minister s conference held in january 1952 the conference was held in the context of british economic and military decline and the united states surging role in the world the principal topic of the conference was the convertibility and liquidity of pound sterling into american dollars and british concerns that non sterling commonwealth countries were building up sterling balances for the purpose of conversion into american dollars the future of the pound sterling area and the alleviation of commonwealth trade restrictions and imperial preference particularly in the light of the surging american economy and the desire of commonwealth countries such as australia for american investment in order for economic development to occur against british concerns that american economic dominance threatened britain s economic position this discussion was necessary as the commonwealth with the exception of canada had a common pool of gold and dollar reserves little was accomplished in the economic discussion with the final communique being described as an agreement in platitudes british concerns at being excluded from the anzus military treaty between australia new zealand and the united states were also a topic and were addressed by a communique issued by the prime ministers supporting britain s demand for a voice in anzus in addition commonwealth prime ministers after months of discussion on whether the newly ascended queen elizabeth ii should have a uniform royal styles and titles throughout the commonwealth or whether realms should adopt their own styles and titles it was agreed that each member of the commonwealth should use for its own purposes a form of the royal style and titles which suits its own particular circumstances but retains a substantial element which is common to all and agreed to pass appropriate legislation in their respective parliaments the prime ministers also agreed to proclaim the new queen elizabeth ii head of the commonwealth in succession of her late father george vi
the 1955 hawaiian submarine eruption was a submarine eruption that occurred 90 km 56 mi northeast of necker island on august 20 1955 steaming water water discoloration and an eruption column took place during the eruption a possible pumice raft was also witnessed the eruption originated about 4 km 2 5 mi below sea level from an unnamed submarine volcano the eruption produced a column of smoke several meters high it is probably the westernmost historical eruption within the hawaiian islands another but less certain submarine eruption may have occurred 60 km 37 mi northwest of oahu on may 22 1956
the 1963 syrian coup d état referred to by the syrian government as the 8 march revolution arabic ثورة الثامن من آذار ‎ ‎ was the successful seizure of power in syria by the military committee of the syrian regional branch of the arab socialist ba ath party the planning and the unfolding conspiracy was inspired by the iraqi regional branch s successful military coup the coup was planned by the military committee rather than the ba ath party s civilian leadership but michel aflaq the leader of the party consented to the conspiracy the leading members of the military committee throughout the planning process and in the immediate aftermath of taking power were muhammad umran salah jadid and hafez al assad the committee enlisted the support of two nasserists rashid al qutayni and muhammad al sufi and the independent ziad al hariri the coup was originally planned for 7 march but was postponed one day after the government discovered where the conspirators were planning to assemble
the 1965 6 6 british home championship was a cause of great excitement as it supplied spectators and commentators a view of england prior to their contesting the football 1966 fifa world cup on home soil at which they were one of the favorites none of the other home nations had qualified for the world cup and so were determined to spoil england s preparation leading to some very dramatic and heavily contested matches particularly england s final game in glasgow the england team began with a subdued goalless draw with the welsh side whilst northern ireland national football team beat scotland 3 – 2 in a close fought game at home both england and scotland improved in their second games england beating a tough irish side at home 2 – 1 whilst the scots put four goals past the struggling welsh wales suffered further in their final match of the series losing 1 – 4 at home to the irish who claimed a surprise second place in the tournament england and scotland then played a thrilling game in glasgow which england finally won 4 – 3 to take the title of british champions a title they would add to at the world cup three months later
the 1966 chicago west side riot was a public disorder that occurred between july 12 and 15 in chicago illinois after a man was arrested for opening a fire hydrant black residents took to the streets in anger and looted and burned various stores throughout the west side until the arrival of 1 200 national guardsmen on july 15 violence quickly subsided and most of the troops were sent home on july 20
the 1967 detroit riot also known as the 12 th street riot was a violent public disorder that turned into a civil disturbance in detroit michigan it began in the early morning hours of sunday july 23 1967 the precipitating event was a police raid of an unlicensed after hours bar then known as a blind pig just north of the corner of 12 th street today rosa parks boulevard and clairmount avenue on the city s near west side police confrontations with patrons and observers on the street evolved into one of the deadliest and most destructive riots in the history of the united states lasting five days and surpassing the violence and property destruction of detroit s 1943 race riot to help end the disturbance governor george w romney ordered the michigan army national guard into detroit and president lyndon b johnson sent in both the 82 nd and 101 st airborne divisions the result was 43 dead 1 189 injured over 7 200 arrests and more than 2 000 buildings destroyed the scale of the riot was surpassed in the united states only by the 1863 new york city draft riots during the u s civil war and the 1992 los angeles riots the riot was prominently featured in the news media with live television coverage extensive newspaper reporting and extensive stories in time and life magazines the staff of the detroit free press won the 1968 pulitzer prize for general local reporting for its coverage
the 1967 newark riots were a major civil disturbance that occurred in the city of newark new jersey between july 12 and july 17 1967 the six days of rioting looting and destruction left 26 dead and hundreds injured
the 1968 detroit riot was a civil disturbance that occurred between april 4 – 5 1968 in detroit michigan following the assassination of martin luther king jr less than a year after the violent unrest of 1967 areas of 12 th street present day rosa parks boulevard again erupted in chaos simultaneously with 110 other us cities following king s assassination michigan governor george w romney ordered the national guard into detroit one person was killed and gangs tossed objects at cars and smashed storefront windows with three dozen fires being set
the 1968 kham duc c 130 shootdown was the loss of a united states air force lockheed c 130 b hercules aircraft during the battle of kham duc on may 12 1968 all 155 people on board were killed at the time it was the deadliest aircraft crash in history the aircraft commanded by major bernard l butcher was participating in the evacuation of south vietnamese civilians from the kham duc campsite the c 130 approached the kham duc airstrip from the south and managed to land despite taking hits from opposing north vietnamese forces as soon as it landed approximately 149 south vietnamese rushed onto the aircraft once the aircraft was full major butcher proceeded to take off in a northward direction unaware that the north vietnamese were concentrated in that area according to eyewitness reports the aircraft under intense enemy mortar and small arms fire shook violently out of control crashed into a nearby ravine less than a mile from the end of the airstrip and burned killing all of the south vietnamese evacuees and the aircraft s crew of six with 155 fatalities this incident along with the civilian crash of viasa flight 742 in venezuela the following year held the highest death toll of any aircraft crash commercial or military in the history of aviation that remained so until the mid air collision of all nippon airways flight 58 and a fighter jet over japan in 1971 killing 162 to date the kham duc crash along with the crash of a usaf lockheed c 5 galaxy aircraft seven years later remain jointly the deadliest aviation accidents incidents on vietnamese soil
the 1968 new york city riot was a disturbance sparked by the assassination of martin luther king on april 4 1968 harlem the largest african american neighborhood in manhattan was expected to erupt into looting and violence like it had done a year earlier in which two dozen stores were either burglarized or burned and three people were killed however mayor john lindsay traveled into the heart of the area and stated that he regretted king ’ s wrongful death which led to the calming of residents various businesses were still looted and set afire in harlem and brooklyn although these events were not widespread and very minor when compared to the riots in washington d c baltimore and chicago in which federal troops were needed to quell the disorders
the 1970 memorial park riot was a civil disturbance by alienated white youths that began in royal oak michigan on august 24 1970 and spread to birmingham michigan both primarily white middle class suburbs of detroit the initial conflict resulted from the closure by police of memorial park in royal oak authorities said that the park was being used as a marketplace for the sale of illegal drugs the riot lasted for three days and led to the formation of several youth controlled social service organizations
the chapeltown riots of 1981 took place in the leeds district of chapeltown in west yorkshire england during a time when many other areas of the uk were suffering similar problems such as london birmingham and liverpool the riots unfolded in july 1981 from a background of racial tension inner city poverty poor housing and high unemployment which was rising rapidly as a result of the recession at the time this brought high tension particularly amongst the area s caribbean community culminating in attacks on the local police these weren t to be the last riots in the area in 1987 there was further rioting in chapeltown and in 2001 there was widespread rioting in nearby harehills
the toxteth riots of july 1981 were a civil disturbance in toxteth inner city liverpool which arose in part from long standing tensions between the local police and the black community they followed the brixton riots earlier that year
the 1983 melbourne dust storm was a meteorological phenomenon that occurred during the afternoon of 8 february 1983 throughout much of victoria australia and affected the capital melbourne red soil dust and sand from central and southeastern australia was swept up in high winds and carried southeast through victoria the dust storm was one of the most dramatic consequences of the 1982 83 drought at the time the worst in australian history and is in hindsight viewed as a precursor to the ash wednesday bushfires which were to occur eight days later
the 1984 rajneeshee bioterror attack was the food poisoning of 751 individuals in the dalles oregon through the deliberate contamination of salad bars at ten local restaurants with salmonella a leading group of followers of bhagwan shree rajneesh later known as osho had hoped to incapacitate the voting population of the city so that their own candidates would win the 1984 wasco county elections the incident was the first and single largest bioterrorist attack in united states history the attack is one of only two confirmed terrorist uses of biological weapons to harm humans since 1945 the other being the 2001 anthrax attacks across the usa having previously gained political control of antelope oregon rajneesh s followers who were based in nearby rajneeshpuram sought election to two of the three seats on the wasco county circuit court that were up for election in november 1984 fearing they would not gain enough votes rajneeshpuram officials decided to incapacitate voters in the dalles the largest population center in wasco county the chosen biological agent was salmonella enterica typhimurium which was first delivered through glasses of water to two county commissioners and then on a larger scale at salad bars and in salad dressing as a result of the attack 751 people contracted salmonellosis 45 of whom were hospitalized there were no fatalities although an initial investigation by the oregon public health division and the centers for disease control did not rule out deliberate contamination the agents and fact of contamination were only discovered a year later on february 28 1985 congressman james h weaver gave a speech in the united states house of representatives in which he accused the rajneeshees of sprinkling salmonella culture on salad bar ingredients in eight restaurants at a press conference in september 1985 rajneesh accused several of his followers of participation in this and other crimes including an aborted plan in 1985 to assassinate a united states attorney and he asked state and federal authorities to investigate oregon attorney general david b frohnmayer set up an interagency task force composed of oregon state police and the federal bureau of investigation and executed search warrants in rajneeshpuram a sample of bacteria matching the contaminant that had sickened the town residents was found in a rajneeshpuram medical laboratory two leading rajneeshpuram officials were convicted on charges of attempted murder and served 29 months of 20 year sentences in a minimum security federal prison
the 1998 national league championship series nlcs to determine the champion of major league baseball s national league was played from october 7 to 14 between the east division champion atlanta braves and the west division champion san diego padres the braves entered the playoffs for the seventh straight season with a franchise record 106 regular season wins an offense that hit 215 home runs and a pitching staff made up of greg maddux tom glavine john smoltz denny neagle and kevin millwood to the playoffs however they also carried the baggage of their embarrassing nlcs loss to the florida marlins the previous season in the nlds the braves swept sammy sosa and the chicago cubs after a 76 – 86 season in 1997 san diego stormed out and took control of their division finishing with a 98 – 64 record their best in team history the offense was led by the 50 home run club s newest member greg vaughn and by hall of famer tony gwynn the san diego rotation was anchored by eighteen game winner kevin brown who helped florida defeat atlanta in the 1997 nlcs along with all star andy ashby and the series mvp sterling hitchcock closer trevor hoffman saved an astounding 53 games in the regular season the padres defeated the favored houston astros in four games in the nlds it was the seventh consecutive nlcs appearance for the braves and they would be heavily favored against the padres
the 1999 myanmar embassy siege of 7 october 1999 was the seizure of the burmese embassy in bangkok thailand a group of burmese dissidents from the vigorous burmese student warriors vbsw and allegedly god s army stormed the burmese embassy and held 89 people including embassy staff burmese nationals foreigners and thai citizens all hostages were released unharmed and the hostage takers escorted to the burmese thai border by thai authorities
1 p 36 deletion syndrome also known as monosomy 1 p 36 is a congenital genetic disorder characterized by moderate to severe intellectual disability delayed growth hypotonia seizures limited speech ability malformations hearing and vision impairment and distinct facial features the symptoms may vary depending on the exact location of the chromosomal deletion the condition is caused by a genetic deletion loss of a segment of dna on the outermost band on the short arm p of chromosome 1 it is one of the most common deletion syndromes it is estimated that the syndrome occurs in one in every 5 000 to 10 000 births knowledge of the disorder has increased a great deal over the last decade mainly because more patients have been accurately diagnosed and described in international medical literature
1 q 21 1 deletion syndrome or 1 q 21 1 recurrent microdeletion is a rare aberration of chromosome 1 a human cell has one pair of identical chromosomes on chromosome 1 with the 1 q 21 1 deletion syndrome one chromosome of the pair is not complete because a part of the sequence of the chromosome is missing one chromosome has the normal length and the other is too short in 1 q 21 1 the 1 stands for chromosome 1 the q stands for the long arm of the chromosome and 21 1 stands for the part of the long arm in which the deletion is situated the syndrome is a form of the 1 q 21 1 copy number variations and it is a deletion in the distal area of the 1 q 21 1 part the cnv leads to a very variable phenotype and the manifestations in individuals are quite variable some people who have the syndrome can function in a normal way while others have symptoms of mental retardation and various physical anomalies 1 q 21 1 microdeletion is a very rare chromosomal condition only 46 individuals with this deletion have been reported in medical literature as of august 2011
1 q 21 1 duplication syndrome or 1 q 21 1 recurrent microduplication is a rare aberration of chromosome 1 unique the international rare chromosome disorder group has 57 genetically confirmed registered cases of this duplication worldwide october 2012 in a common situation a human cell has one pair of identical chromosomes on chromosome 1 with the 1 q 21 1 duplication syndrome one chromosome of the pair is over complete because a part of the sequence of the chromosome is duplicated twice or more in 1 q 21 1 the 1 stands for chromosome 1 the q stands for the long arm of the chromosome and 21 1 stands for the part of the long arm in which the duplication is situated next to the duplication syndrome there is also a 1 q 21 1 deletion syndrome while there are two or three copies of a similar part of the dna on a particular spot with the duplication syndrome there is a part of the dna missing with the deletion syndrome on the same spot literature refers to both the deletion and the duplication as the 1 q 21 1 copy number variations cnv the cnv leads to a very variable phenotype and the manifestations in individuals are quite variable some people who have the syndrome can function in a normal way while others have symptoms of mental retardation and various physical anomalies
the 1 st kisei was the birth of a new go tournament since this was the first year of the tournament there was no set challenger or holder from the 2 nd edition on there has been a playoff between challengers at the time it was the highest paying tournament there had ever been and would be until the creation of the ing cup fujisawa hideyuki s win would mark the beginning of a six year defense of the kisei title from 1977 to 1982
2 4 dienoyl coa reductase deficiency is an inborn error of metabolism resulting in defective fatty acid oxidation caused by a deficiency of the enzyme 2 4 dienoyl coa reductase lysine degradation is also affected in this disorder leading to hyperlysinemia the disorder is inherited in an autosomal recessive manner meaning an individual must inherit mutations in nadk 2 located at 5 p 13 2 from both of their parents nadk 2 encodes the mitochondrial nad kinase a defect in this enzyme leads to deficient mitochondrial nicotinamide adenine dinucleotide phosphate levels 2 4 dienoyl coa reductase but also lysine degradation are performed by nadp dependent oxidoreductases explaining how nadk 2 deficiency can lead to multiple enzyme defects 2 4 dienoyl coa reductase deficiency was initially described in 1990 based on a single case of a black female who presented with persistent hypotonia laboratory investigations revealed elevated lysine low levels of carnitine and an abnormal acylcarnitine profile in urine and blood the abnormal acylcarnitine species was eventually identified as 2 trans 4 cis decadienoylcarnitine an intermediate of linoleic acid metabolism the index case died of respiratory failure at four months of age postmortem enzyme analysis on liver and muscle samples revealed decreased 2 4 dienoyl coa reductase activity when compared to normal controls a second case with failure to thrive developmental delay lactic acidosis and severe encephalopathy was reported in 2014 2 4 dienoyl coa reductase deficiency was included as a secondary condition in the american college of medical genetics recommended uniform panel for newborn screening its status as a secondary condition means there was not enough evidence of benefit to include it as a primary target but it may be detected during the screening process or as part of a differential diagnosis when detecting conditions included as primary target despite its inclusion in newborn screening programs in several states for a number of years no cases have been identified via neonatal screening
2 hydroxyglutaric aciduria is a group of rare neurometabolic disorders characterized by the significantly elevated levels of hydroxyglutaric acid in ones urine it is either autosomal recessive or autosomal dominant
2 methylbutyryl coa dehydrogenase deficiency also called 2 methylbutyryl glycinuria or short branched chain acyl coa dehydrogenase deficiency sbcadd is an autosomal recessive metabolic disorder it causes the body to be unable to process the amino acid isoleucine properly initial case reports identified individuals with developmental delay and epilepsy however most cases identified through newborn screening have been asymptomatic
in computer science 2 satisfiability is a computational problem of assigning values to variables each of which has two possible values in order to satisfy a system of constraints on pairs of variables it is a special case of the general boolean satisfiability problem which can involve constraints on more than two variables and of constraint satisfaction problems which can allow more than two choices for the value of each variable but in contrast to those more general problems which are np complete 2 satisfiability can be solved in polynomial time 2 satisfiability is often abbreviated as 2 sat or just 2 sat instances of the 2 satisfiability problem are typically expressed as boolean formulas of a special type called conjunctive normal form 2 cnf or krom formulas alternatively they may be expressed as a special type of directed graph the implication graph which expresses the variables of an instance and their negations as vertices in a graph and constraints on pairs of variables as directed edges both of these kinds of inputs may be solved in linear time either by a method based on backtracking or by using the strongly connected components of the implication graph resolution a method for combining pairs of constraints to make additional valid constraints also leads to a polynomial time solution 2 satisfiability may be applied to geometry and visualization problems in which a collection of objects each have two potential locations and the goal is to find a placement for each object that avoids overlaps with other objects other applications include clustering data to minimize the sum of the diameters of the clusters classroom and sports scheduling and recovering shapes from information about their cross sections in computational complexity theory 2 satisfiability provides an example of an nl complete problem one that can be solved non deterministically using a logarithmic amount of storage and that is among the hardest of the problems solvable in this resource bound the set of all solutions to a 2 satisfiability instance can be given the structure of a median graph but counting these solutions is p complete and therefore not expected to have a polynomial time solution random instances undergo a sharp phase transition from solvable to unsolvable instances as the ratio of constraints to variables increases past 1 a phenomenon conjectured but unproven for more complicated forms of the satisfiability problem a computationally difficult variation of 2 satisfiability finding a truth assignment that maximizes the number of satisfied constraints has an approximation algorithm whose optimality depends on the unique games conjecture and another difficult variation finding a satisfying assignment minimizing the number of true variables is an important test case for parameterized complexity
the 2003 midwest monkeypox outbreak marked the first time monkeypox infection has appeared in the united states and the first time in the western hemisphere beginning in may 2003 a total of 71 cases of human monkeypox were found in five midwestern states including wisconsin 39 cases indiana 16 illinois 12 kansas 1 missouri 2 and ohio 1 the cause of the outbreak was traced to gambian pouched rats imported into the united states by an exotic animal importer in texas the rats were shipped from texas to an illinois distributor who housed them with prairie dogs no deaths were reported no human to human transmission was found all cases involved direct contact with infected prairie dogs electron microscopy and testing by polymerase chain reaction and immunohistochemistry were used to confirm the causative agent was human monkeypox
serena williams successfully defended her title beating her older sister venus williams in the final for the second year in a row 4 – 6 6 – 4 6 – 2 this was the first wimbledon appearance of future world no 1 maria sharapova played in the main draw she would go on to win the title in the following year
the 2005 royal air force hercules shootdown was the loss of a royal air force lockheed c 130 k hercules c 3 serial number xv 179 callsign hilton 22 when it was shot down in iraq probably by sunni insurgents on 30 january 2005 killing all 10 personnel on board at the time the incident was the largest single loss of life suffered by the british military during operation telic the board of inquiry report in december 2005 identified the lack of a fire suppressant system as a contributory factor in september 2006 the british channel 4 news aired an article criticising the ministry of defence for having fitted only one c 130 hercules with a foam fire suppressant system the raf had ordered a retrofit of this system to all front line c 130 aircraft a system which could well have prevented the loss of aircraft xv 179 and its crew
the 2006 mexico dc 9 drug bust was a 2006 arrest that resulted in the seizure of 5 5 tons of cocaine in the mexican city of ciudad del carmen the drugs were smuggled into the country using a mcdonnell douglas dc 9 15 both plane and drugs were seized by mexican authorities according to the united states drug enforcement agency dea it was one of the largest seizures of narcotics in recent mexican history
the 2006 mumbai sweet seawater incident was a strange phenomenon during which residents of mumbai claimed that the water at mahim creek had suddenly turned sweet within hours residents of gujarat claimed that seawater at teethal beach had turned sweet as well this caused a mass hysteria among people who started coming in large numbers to drink the sea water
the western australian gas crisis was a major disruption to natural gas supply in western australia caused by the rupture of a corroded pipeline and subsequent explosion at a processing plant on varanus island off the state s north west coast on 3 june 2008 the plant operated by apache energy which normally supplied a third of the state s gas was shut down for almost two months while a detailed engineering investigation and major repairs were carried out gas supply from the plant partially resumed in late august by mid october gas production was running at two thirds of normal capacity with 85 of full output restored by december 2008 in a state heavily reliant on continuous supply of gas for industrial processing manufacturing residential use and electricity generation the sudden loss of almost 35 of gas supply had immediate social impacts and significant short and long term economic effects many businesses were forced to curtail or cease operations resulting in workers being stood down or forced to take annual leave and the government requested that businesses and householders conserve energy usage an emergency coordination committee of government and industry representatives rationed and redirected remaining gas supply sources when many large gas users switched to diesel for power generation the risk of a shortfall in transport fuel led to the federal government authorising the release of emergency fuel reserves stored at the garden island naval facility the incident raised significant public and political issues related to energy security adequacy of existing infrastructure contingency planning and the role of regulatory agencies the plant took three months to repair although partial supplies were restored within six weeks of the explosion a major investigation was launched by the national offshore petroleum safety authority nopsa with separate investigations conducted by the plant operator and several other government agencies nopsa s report was published on 10 october 2008 and confirmed early suggestions that the explosion was caused by structural failure of the export pipeline due to significant corrosion a senate committee inquiry was established to investigate the economic impacts and the state government s response to the crisis the committee s report was handed down on 3 december 2008
the 2009 turks and caicos islands migrant shipwreck was the loss near the turks and caicos islands of a boat carrying migrants from haiti late on the night of 26 july 2009 sixty five persons are still missing earlier figures of 79 missing migrants were reduced as bodies were recovered at least fifteen corpses have thus far been located the boat spent three days at sea before it capsized one survivor said the craft ended up on a reef while attempting to escape a patrolling police vessel a turks and caicos police sergeant confirmed that the boat hit molasses reef near west caicos of the 124 people who were rescued 102 were male 22 were female several severely injured migrants were helicoptered to a hospital in providenciales many were brought ashore aboard small boats whilst five migrants were located alive and well after seemingly having swum to safety the incident was reported to the united states coast guard by authorities from turks and caicos a spokesperson for the coast guard said they rescued 113 migrants and were assisting in the search for those who were still missing he said they were hopeful of finding more missing migrants alive but that it has been a night and we have not located any additional people a helicopter and a cutter were also sent by the united states an investigation is underway to determine the cause the boat had no motor hubert hughes turks and caicos deputy police commissioner claimed police had not been chasing the boat and only assisted when it became apparent that it had gotten into trouble repatriation of haitians was commenced immediately the incident followed the interception of 124 haitian migrants from what was described as a grossly overloaded boat that was travelling southwest of this incident those migrants were quickly returned to haiti
the 2009 flu pandemic or swine flu was an influenza pandemic and the second of the two pandemics involving h 1 n 1 influenza virus the first of them being the 1918 flu pandemic albeit in a new version first described in april 2009 the virus appeared to be a new strain of h 1 n 1 which resulted when a previous triple reassortment of bird swine and human flu viruses further combined with a eurasian pig flu virus leading to the term swine flu unlike most strains of influenza h 1 n 1 does not disproportionately infect adults older than 60 years this was an unusual and characteristic feature of the h 1 n 1 pandemic even in the case of previously very healthy people a small percentage will develop pneumonia or acute respiratory distress syndrome ards this manifests itself as increased breathing difficulty and typically occurs 3 – 6 days after initial onset of flu symptoms the pneumonia caused by flu can be either direct viral pneumonia or a secondary bacterial pneumonia in fact a november 2009 new england journal of medicine article recommends that flu patients whose chest x ray indicates pneumonia receive both antivirals and antibiotics in particular it is a warning sign if a child and presumably an adult seems to be getting better and then relapses with high fever as this relapse may be bacterial pneumonia
the 2009 refugee crisis in pakistan was the massive displacement of civilians in the khyber pakhtunkhwa of pakistan that was caused by operation black thunderstorm since the beginning of operation black thunderstorm against the taliban over 1 2 million people have been displaced in across pakistan s khyber pakhtunkhwa joined by a further 555 000 pakistanis uprooted by fighting since august 2008 the refugees are known in pakistan as internally displaced persons idps most of the 1 2 million people who have escaped the violence were staying with relatives or friends placing tremendous strain on the country while over 300 000 others are seeking refuge in unhcr supported camps by august 22 1 6 million of 2 2 million returned home as per un estimates
in the year 2010 there was a dramatic increase and prominence in the use of 3 d technology in filmmaking after the success of avatar in the format with releases such as alice in wonderland clash of the titans jackass 3 d all animated films with numerous other titles being released in 3 d formats 20 th century fox celebrated its 75 th anniversary in 2010
a novel strain of escherichia coli o 104 h 4 bacteria caused a serious outbreak of foodborne illness focused in northern germany in may through june 2011 the illness was characterized by bloody diarrhea with a high frequency of serious complications including hemolytic uremic syndrome hus a condition that requires urgent treatment the outbreak was originally thought to have been caused by an enterohemorrhagic ehec strain of e coli but it was later shown to have been caused by an enteroaggregative e coli eaec strain that had acquired the genes to produce shiga toxins present in organic fenugreek sprouts epidemiological fieldwork suggested fresh vegetables were the source of infection the agriculture minister of lower saxony identified an organic farm in bienenbüttel lower saxony germany which produces a variety of sprouted foods as the likely source of the e coli outbreak the farm was shut down although laboratories in lower saxony did not detect the bacterium in produce a laboratory in north rhine westphalia later found the outbreak strain in a discarded package of sprouts from the suspect farm a control investigation confirmed the farm as the source of the outbreak on 30 june 2011 the german bundesinstitut für risikobewertung bfr federal institute for risk assessment an institute of the german federal ministry of food agriculture and consumer protection announced that seeds of organic fenugreek imported from egypt were likely the source of the outbreak in all 3 950 people were affected and 53 died 51 of whom were in germany 800 people suffered hemolytic uremic syndrome hus which can lead to kidney failure a handful of cases were reported in several other countries including switzerland poland the netherlands sweden denmark the uk canada and the usa essentially all affected people had been in germany or france shortly before becoming ill initially german officials made incorrect statements on the likely origin and strain of escherichia coli the german health authorities without results of ongoing tests incorrectly linked the o 104 serotype to cucumbers imported from spain later they recognised that spanish greenhouses were not the source of the e coli and cucumber samples did not contain the specific e coli variant causing the outbreak spain consequently expressed anger about having its produce linked with the deadly e coli outbreak which cost spanish exporters us 200 million per week russia banned the import of all fresh vegetables from the european union from early june until 22 june 2011
the 2011 nabro eruption was an eruption of the nabro stratovolcano in the southern red sea region of eritrea which began on 12 june 2011 after a series of earthquakes the eruption killed seven and possibly a further 31 people and is estimated to be the highest altitude injection of sulfur dioxide so 2 ever observed by satellite the mount pinatubo eruption 20 years earlier emitted ten times more so 2 the ash cloud from the eruption reached altitudes which disrupted airline traffic in the region until the eruption began the volcano had no records of historical eruptions
the 2011 puyehue cordón caulle eruption puˈʝewe was a volcanic eruption that began in the puyehue cordón caulle volcanic complex in chile on 6 june 2011 misleadingly called by media the puyehue eruption – the eruption is actually from the cordón caulle fissure after 51 years of the volcano being inactive at least 3 500 people were evacuated from nearby areas while the ash cloud was blown across cities all around the southern hemisphere including bariloche buenos aires montevideo stanley porto alegre cape town hobart perth adelaide sydney melbourne wellington and auckland port moresby forcing airlines to cancel hundreds of international and domestic flights and causing travel chaos by 18 june the ash cloud had completed its first circle of the globe the chilean civil aviation authority said that the tip of the cloud that has travelled around the world has more or less reached the town of coyhaique about 600 kilometres south of the puyehue cordón caulle an estimated one hundred million tons of ash sand and pumice were ejected – requiring power equivalent to 70 atomic bombs cordón caulle is a volcanic fissure and has erupted many times in recorded history most recently in 1960 following the 1960 valdivia earthquake days earlier whereas the puyehue stratocone has remained dormant
the 2011 vancouver stanley cup riot was a public disturbance that broke out in the downtown core of vancouver british columbia canada on wednesday june 15 2011 the riot happened immediately after the conclusion of the boston bruins win over the vancouver canucks in game seven of the stanley cup finals which won the stanley cup for boston at least 140 people were reported as injured during the incident 1 critically at least 4 people were stabbed 9 police officers were injured and 101 people were arrested that night in july 2015 four years after the riot police finished their investigation and recommended the final charges against two suspects bringing the total to 887 charges laid against 301 people
in november 2010 more than 21 204 people were diagnosed with dengue fever those infected were mainly from punjab pakistan patients were admitted to dedicated wards in government hospitals the severity of the epidemic was greatest in lahore the secretary of the punjab mineral development corporation ataullah siddiqui and ghiasuddin a member of the punjab public service commission died as a result of the dengue fever on 30 september 2011 the punjab mpa mumtaz jajja also died of dengue fever eight chinese engineers were taken ill
the 2011 eruption of grímsvötn was an eruption in grímsvötn iceland s most active volcano which caused disruption to air travel in northwestern europe from 22 – 25 may 2011 the last eruption of grímsvötn was in 2004 with the previous most powerful eruptions in 1783 1873 and 1902 the grímsvötn eruption was the largest eruption in iceland for 50 years
the 2012 kermadec islands eruption was a major undersea volcanic eruption that was produced by the previously little known havre seamount near the l esperance and l havre rocks in the kermadec islands of new zealand the large volume of low density pumice produced by the eruption accumulated as a large area of floating pumice a pumice raft that was originally covering a surface of 400 km ² spread to a continuous float of between 7 500 and 10 000 square miles 19 000 and 26 000 km 2 and within three month dispersed to an area of more than twice the size of new zealand the thickness of the raft may initially have been as high as 3 5 m and was reduced to around 0 5 m within a month three months after the eruption the mass had dispersed into very dilute rafts and ribbons of floating pumice clasts most pumice clasts became waterlogged and sunk to the sea floor while some flocks have stranded in the tonga islands on the northern shores of new zealand and eventually on the eastern coast of australia one year after the eruption
the 2012 – 13 swansea measles epidemic began in november 2012 and was declared over on 3 july 2013 there were a total of 1 219 measles notifications suspected cases in swansea neath port talbot bridgend carmarthenshire ceredigion pembrokeshire and powys with 1 455 measles notifications for the whole of wales 664 of which were in swansea alone a total of 88 people were hospitalised for measles infection during the epidemic one death was reported a 25 year old man suffering from giant cell pneumonia brought on by measles infection died on 18 april 2013 the cost associated with treating the sick and controlling the outbreak exceeded £ 470 000 701 898 some sources linked the outbreak with the mmr vaccine controversy and a campaign in the south wales evening post in the 1990 s against the mmr vaccine as the majority of those who became infected were not immunised as infants during the mmr scare uptake of the mmr vaccine fell from 94 of two year olds in wales in 1995 to 78 by 2003 in the swansea area the uptake fell to 67 5 the south wales evening post was also criticised for appearing to exaggerate the number of confirmed measles cases that occurred during the epidemic in the wake of the outbreak mmr clinics were set up in four hospitals in swansea and neath port talbot and vaccinated over 1 800 people several politicians including welsh first minister carwyn jones urged the public to make sure their children were vaccinated politicians and vaccine experts also called for mandatory vaccinations to be implemented the welsh government opposed mandatory vaccination believing that trust in the mmr vaccine had been regained and could be damaged if it were mandatory hywel dda health board offered the vaccine in april 2013 in the surrounding counties of carmarthen ceredigion and pembrokeshire in a bid to contain the outbreak vaccinations were held in all comprehensive schools in powys there were concerns that the epidemic could spread to london and infect many more people prompting the department of health to set up a mass vaccination campaign targeted at one million school children throughout england the following table shows measles notifications by the nhs health board reported notifications tend to exceed confirmed cases public health wales issued a statement saying measles is one of a number of notifiable diseases doctors in wales have a statutory duty to notify a proper officer of the local authority of suspected cases of measles based on clinical symptoms usually before diagnosis has been confirmed by laboratory testing reported notifications of measles usually far exceed the actual numbers of confirmed cases other rashes are often mistaken for measles
the 2014 peninsula malaysia tornado outbreak malay serangan puting beliung semenanjung malaysia 2014 is a natural phenomenon that took place in the state of kedah and selangor malaysia from 14 october to 12 november 2014
the 2014 – 2015 eruption of bárðarbunga was an eruption in the bárðarbunga volcanic system in iceland that began on august 29 2014 and ended on february 27 2015 the eruption emitted large volumes of sulphur dioxide and impacted air quality in iceland there was no effect on flights outside of the immediate vicinity due to a lack of a significant emission of volcanic ash the eruption took place in the lava field of holuhraun northeast of the bárðarbunga caldera proper
the 2015 texas pool party incident also known as the mckinney pool party was a civil and domestic disturbance that occurred on june 5 2015 at a pool party in a gated mckinney texas community a mckinney police officer was video recorded restraining an unarmed african american fifteen year old girl on the ground he later drew his handgun during the same incident the incident was caught on video and was posted on youtube by another teenage partygoer within hours millions of people had seen the video the officer shown in the video was placed on administrative leave pending an investigation and later resigned the incident sparked protests in mckinney involving hundreds of people
during the 20 th century there was a vast increase in the variety of music that people had access to prior to the invention of mass market gramophone records developed in 1892 and radio broadcasting first commercially done ca 1919 – 20 people mainly listened to music at live classical music concerts or musical theatre shows which were too expensive for many lower income people on early phonograph players a technology invented in 1877 which was not mass marketed until the mid 1890 s or by individuals performing music or singing songs on an amateur basis at home using sheet music which required the ability to sing play and read music which were skills that tended to be limited to middle class and upper class individuals with the mass market availability of gramophone records and radio broadcasts listeners could purchase recordings of or listen on radio to recordings or live broadcasts of a huge variety of songs and musical pieces this enabled a much wider range of the population to listen to performances of classical music symphonies and operas that they would not be able to hear live either due to not being able to afford live concert tickets or because such music was not performed in their region sound recording was also a major influence on the development of popular music genres because it enabled recordings of songs and bands to be inexpensively and widely distributed nationwide or even for some artists worldwide the development of relatively inexpensive reproduction of music via a succession of formats including vinyl records compact cassettes compact discs introduced in 1983 and by the mid 1990 s digital audio recordings and the transmission or broadcast of audio recordings of music performances on radio of video recordings or live performances on television and by the 1990 s of audio and video recordings via the internet using file sharing of digital audio recordings gave individuals from a wide range of socioeconomic classes access to a diverse selection of high quality music performances by artists from around the world the introduction of multitrack recording in 1955 and the use of mixing had a major influence on pop and rock music because it enabled record producers to mix and overdub many layers of instrument tracks and vocals creating new sounds that would not be possible in a live performance the development of sound recording and audio engineering technologies and the ability to edit these recordings gave rise to new subgenres of classical music including the musique concrète 1949 and acousmatic 1955 schools of electronic composition in the 1970 s african american hip hop musicians began to use the record turntable as a musical instrument creating rhythmic and percussive scratching effects by manipulating a vinyl record on the turntable the 20 th century orchestra was far more flexible than its predecessors and used a much wider variety of instruments in beethoven s and felix mendelssohn s time in the 19 th century the orchestra was composed of a fairly standard core of instruments which was very rarely modified as time progressed and as the romantic period saw changes in accepted modification with composers such as berlioz and mahler the 20 th century saw that instrumentation could practically be hand picked by the composer saxophones were used in some 20 th century orchestra scores such as vaughan williams symphonies no 6 and 9 and william walton s belshazzar s feast and many other works as a member of the orchestral ensemble twentieth century orchestras generally include a string section woodwinds brass instruments percussion piano celeste harp s with other instruments called for occasionally such as electric guitar and electric bass the 20 th century saw dramatic innovations in musical forms and styles composers and songwriters explored new forms and sounds that challenged the previously accepted rules of music of earlier periods such as the use of altered chords and extended chords in 1940 s era bebop jazz the development of powerful loud guitar amplifiers and sound reinforcement systems in the 1960 s and 1970 s permitted bands to hold large concerts where even those with the least expensive tickets could hear the show composers and songwriters experimented with new musical styles such as genre fusions e g the late 1960 s fusion of jazz and rock music to create jazz fusion as well composers and musicians used new electric electronic and digital instruments and musical devices in the 1980 s some styles of music such as electronic dance music genres such as house music were created largely with synthesizers and drum machines faster modes of transportation such as jet flight allowed musicians and fans to travel more widely to perform or hear shows which increased the spread of musical styles
22 q 11 2 distal deletion syndrome is a rare genetic condition caused by a tiny missing part of one of the body ’ s 46 chromosomes – chromosome 22 22 q 11 2 distal deletion syndrome appears to be a recurrent genomic disorder distinct from digeorge syndrome dgs 188400 and velocardiofacial syndrome vcfs 192430 the first published description of a person with a 22 q 11 2 distal deletion was in 1999 there have since been hundreds of cases reported worldwide 22 q 11 2 distal deletion syndrome seems to occur equally often in males and females there are reports of people who are unaffected by carrying the deletion and only discovered it after their child was diagnosed it seems that the 22 q 11 2 distal deletion can be silent and it is unknown how many people may have a silent form of this syndrome
22 q 11 2 duplication syndrome is a rare genetic disorder caused by a duplication of a segment at the end of chromosome 22
22 q 13 deletion syndrome spoken as twenty two q one three is a genetic disorder caused by deletions or rearrangements on the q terminal end long arm of chromosome 22 any abnormal genetic variation in the q 13 region that presents with significant manifestations phenotype typical of a terminal deletion should be diagnosed as 22 q 13 deletion syndrome 22 q 13 deletion syndrome is often placed in the more general category of phelan mcdermid syndrome abbreviated pms which includes some mutations and microdeletions the pms name is less precise since there is disagreement among researchers as to which variants belong in the pms category the developmental synaptopathies consortium defines pms as being caused by shank 3 mutations a definition that excludes terminal deletions this latter definition of pms is incompatible with the definition of 22 q 13 deletion syndrome by those who first described 22 q 13 deletion syndrome a prototypical terminal deletion of 22 q 13 can be uncovered by karyotype analysis but many terminal and interstitial deletions are too small the availability of dna microarray technology for revealing multiple genetic problems simultaneously has been the diagnostic tool of choice the falling cost for whole exome sequencing and eventually whole genome sequencing may replace dna microarray technology for candidate evaluation however fluorescence in situ hybridization fish tests remain valuable for diagnosing cases of mosaicism mosaic genetics and chromosomal rearrangements e g ring chromosome unbalanced chromosomal translocation although early researchers sought a monogenic single gene genetic disorder explanation recent studies have not supported that hypothesis see etiology below
2 p 15 16 1 microdeletion is a rare genetic disorder caused by a small deletion in the short arm of human chromosome 2 first described in two patients in 2007 by 2013 only 21 missing reference for the other 17 patients people have been reported as having the disorder in the medical literature
2 q 37 deletion syndrome is a disorder caused by the deletion of a small piece of chromosome 2 2 q 37 deletion syndrome describes a disorder in which one or multiple of 3 sub bands 2 q 37 1 2 q 37 2 and 2 q 37 3 of the last band of one of the chromosome 2 ’ s long arms are deleted the first report of this disorder was in 1989
2 q 37 monosomy is a rare genetic disorder caused by a deletion of a segment at the end of chromosome 2
3 m syndrome alternative names dolichospondylic dysplasia gloomy face syndrome and le merrer syndrome is a rare hereditary growth retardation syndrome the name 3 m originates from the initials of the three authors miller mckusick and malvaux who first reported the syndrome in literature major symptoms of 3 m syndrome are dwarfism facial dysmorphia and skeletal abnormalities no signs of mental retardation are reported 3 m syndrome is thought to be inherited as an autosomal recessive genetic trait
3 methylcrotonyl coa carboxylase deficiency 3 mcc deficiency also known as 3 methylcrotonylglycinuria or bmcc deficiency is an inherited disorder in which the body is unable to process certain proteins properly people with this disorder have inadequate levels of an enzyme that helps break down proteins containing the amino acid leucine this condition affects an estimated 1 in 50 000 individuals worldwide
3 methylglutaconic aciduria mga is used to describe at least five disorders that impair the body s ability to make energy in the mitochondria as a result of this impairment 3 methylglutaconic acid and 3 methylglutaric acid build up and can be detected in the urine 3 methylglutaconic acid is classified as an organic acid the double carboxylic acid functions are the principal cause of the strength of this acid 3 methylglutaconic acid can be detected by the presence of the acid function and the double connection that involves reactivity with some specific substances
3 hydroxyacyl coenzyme a dehydrogenase deficiency hadh deficiency is a rare condition that prevents the body from converting certain fats to energy particularly during fasting normally through a process called fatty acid oxidation several enzymes work in a step wise fashion to metabolize fats and convert them to energy people with 3 hydroxyacyl coenzyme a dehydrogenase deficiency have inadequate levels of an enzyme required for a step that metabolizes groups of fats called medium chain fatty acids and short chain fatty acids for this reason this disorder is sometimes called medium and short chain 3 hydroxyacyl coenzyme a dehydrogenase m schad deficiency
the 3 partition problem is an np complete problem in computer science the problem is to decide whether a given multiset of integers can be partitioned into triples that all have the same sum more precisely given a multiset s of n 3 m positive integers can s be partitioned into m triplets s 1 s 2 … sm such that the sum of the numbers in each subset is equal the subsets s 1 s 2 … sm must form a partition of s in the sense that they are disjoint and they cover s let b denote the desired sum of each subset si or equivalently let the total sum of the numbers in s be m b the 3 partition problem remains np complete when every integer in s is strictly between b 4 and b 2 the 3 partition problem is similar to the partition problem which in turn is related to the subset sum problem in the partition problem the goal is to partition s into two subsets with equal sum in 3 partition the goal is to partition s into m subsets or n 3 subsets not just two subsets with equal sum
3 c syndrome also known as ccc dysplasia craniocerebellocardiac dysplasia or ritscher – schinzel syndrome is a rare condition whose symptoms include heart defects cerebellar hypoplasia and cranial dysmorphism it was first described in the medical literature in 1987 by ritscher and schinzel for whom the disorder is sometimes named
3 d pose estimation is the problem of determining the transformation of an object in a 2 d image which gives the 3 d object the need for 3 d pose estimation arises from the limitations of feature based pose estimation there exist environments where it is difficult to extract corners or edges from an image to circumvent these issues the object is dealt with as a whole through the use of free form contours
3 hydroxyisobutyric aciduria is a disorder of valine metabolism characterised by urinary excretion of 3 hydroxyisobutyric acid
3 q 29 microdeletion syndrome is a rare genetic disorder resulting from the deletion of a segment of chromosome 3 this syndrome was first described in 2005
45 x 46 xy mosaicism also known as x 0 xy mosaicism and mixed gonadal dysgenesis is a rare disorder of sex development in humans associated with sex chromosome aneuploidy and mosaicism of the y chromosome this is called a mosaic karyotype because like tiles in mosaic floors or walls there is more than one type of cell the clinical manifestations are highly variable ranging from partial virilisation and ambiguous genitalia at birth to patients with a completely male or female gonads most individuals with this karyotype have apparently normal male genitalia and a minority with female genitalia with a significant number of individuals showing genital abnormalities or intersex characteristics a significantly higher than normal number of other developmental abnormalities are also found in individuals with x 0 xy mosaicism psychomotor development is normal
46 xx 46 xy is a chimeric genetic disorder caused by having two distinct cell populations within the body the chimerism arises in utero from the combination of an xx zygote and an xy zygote which otherwise would have developed into twins into a single embryo it is not to be confused with mosaicism and hybridism 46 xx 46 xy is typically associated with intersex conditions such as ambiguous genitalia and hermaphroditism 46 xx 46 xy chimerism can be identified during pregnancy by prenatal screening or in early childhood through genetic testing and direct observation
xxxx syndrome also called tetrasomy x quadruple x or 48 xxxx is a rare chromosomal disorder caused by the presence of four x chromosomes instead of two x chromosomes this condition occurs only in females as there are no y chromosomes present tetrasomy x was first described in 1961 and since then approximately 100 cases have been reported worldwide approximately 60 females have been described in medical literature with this condition
xxxxx syndrome also called pentasomy x or 49 xxxxx is a type of aneuploidy an abnormal number of chromosomes which results in the presence of three additional x chromosomes the condition was first described in 1963 it is characterized by severe intellectual disability short stature and abnormalities to the head and face as these features can be seen in other conditions karyotyping must be carried out to confirm diagnosis there have been cases of xxxxx syndrome being misdiagnosed as down syndrome it is an extremely rare condition with no more than 30 patients reported in medical literature the exact incidence is not known but it may be similar to the rate of 1 in 85 000 seen in males with 49 xxxxy syndrome
49 xxxxy syndrome is an extremely rare aneuploidic sex chromosomal abnormality it occurs in approximately 1 out of 85 000 to 100 000 males
the 5 ht 1 a receptor is a subtype of 5 ht receptor that binds the endogenous neurotransmitter serotonin 5 hydroxytryptamine 5 ht it is a g protein coupled receptor gpcr that is coupled to gi go and mediates inhibitory neurotransmission htr 1 a denotes the human gene encoding for the receptor
the mammalian 5 ht 2 a receptor is a subtype of the 5 ht 2 receptor that belongs to the serotonin receptor family and is a g protein coupled receptor gpcr this is the main excitatory receptor subtype among the gpcrs for serotonin 5 ht although 5 ht 2 a may also have an inhibitory effect on certain areas such as the visual cortex and the orbitofrontal cortex this receptor was first noted for its importance as a target of serotonergic psychedelic drugs such as lsd later it came back to prominence because it was also found to be mediating at least partly the action of many antipsychotic drugs especially the atypical ones 5 ht 2 a may be a necessary receptor for the spread of the human polyoma virus called jc virus downregulation of post synaptic 5 ht 2 a receptor is an adaptive process provoked by chronic administration of selective serotonin reuptake inhibitors ssris and classical antipsychotics deceased suicidal and otherwise depressed patients have had more 5 ht 2 a receptors than normal patients these findings suggest that post synaptic 5 ht 2 a overdensity is involved in the pathogenesis of depression
the 5 ht 2 c receptor is a subtype of 5 ht receptor that binds the endogenous neurotransmitter serotonin 5 hydroxytryptamine 5 ht it is a g protein coupled receptor gpcr that is coupled to gq g 11 and mediates excitatory neurotransmission htr 2 c denotes the human gene encoding for the receptor that in humans is located at the x chromosome as males have one copy of the gene and in females one of the two copies of the gene is repressed polymorphisms at this receptor can affect the two sexes to differing extent
the 5 ht 6 receptor is a subtype of 5 ht receptor that binds the endogenous neurotransmitter serotonin 5 hydroxytryptamine 5 ht it is a g protein coupled receptor gpcr that is coupled to gs and mediates excitatory neurotransmission htr 6 denotes the human gene encoding for the receptor
5 α reductase deficiency 5 ard is an autosomal recessive intersex condition caused by a mutation of the 5 α reductase type ii gene
the international 5 5 metre class was created to yield a racing keel boat giving a sailing experience similar to that of the international 6 metre class but at a lower cost the main class regulation is a restriction on a single quantity output from a formula involving the boat s rating length l weight expressed as a displacement d and sail area s the regulation states that the output of this formula must not exceed 5 500 metres there is considerable scope for variations in design while still meeting this restriction and as a result each 5 5 metre boat is unique if the design parameters of a proposed new boat result in a formula output exceeding 5 5 metres then one or more of the parameters must be suitably adjusted performance data gained from testing models towed in a long water tank referred to in yacht design as ship model basin can suggest optimal combinations of parameters the 5 5 metre rule is a variant of the international rule sailing that was established already in 1907 the 5 5 is therefore closely related to larger metre boats such as the 6 mr 8 mr and the 12 mr since 2010 the 5 5 metre is one of the vintage yachting classes at the vintage yachting games
6 pyruvoyltetrahydropterin synthase deficiency is an autosomal recessive disorder that causes malignant hyperphenylalaninemia due to tetrahydrobiopterin deficiency it belongs to the rare diseases it is a recessive disorder that is accompanied by hyperphenylalaninemia commonly reported symptoms are initial truncal hypotonia subsequent appendicular hypertonia bradykinesia cogwheel rigidity generalized dystonia and marked diurnal fluctuation other reported clinical features include difficulty in swallowing oculogyric crises somnolence irritability hyperthermia and seizures chorea athetosis hypersalivation rash with eczema and sudden death have also been reported patients with mild phenotypes may deteriorate if given folate antagonists such as methotrexate which can interfere with a salvage pathway through which dihydrobiopterin is converted into tetrahydrobiopterin via dihydrofolate reductase treatment options include substitution with neurotransmitter precursors levodopa 5 hydroxytryptophan monoamine oxidase inhibitors and tetrahydrobiopterin response to treatment is variable and the long term and functional outcome is unknown to provide a basis for improving the understanding of the epidemiology genotype phenotype correlation and outcome of these diseases their impact on the quality of life of patients and for evaluating diagnostic and therapeutic strategies a patient registry was established by the noncommercial international working group on neurotransmitter related disorders intd
6 phosphogluconate dehydrogenase deficiency 6 pgd deficiency or partial deficiency is an autosomal hereditary disease characterized by abnormally low levels of 6 phosphogluconate dehydrogenase 6 pgd a metabolic enzyme involved in the pentose phosphate pathway it is very important in the metabolism of red blood cells erythrocytes 6 pdg deficiency affects less than 1 of the population and studies suggest that there may be race variant involved in many of the reported cases although it is similar 6 pdg deficiency is not linked to glucose 6 phosphate dehydrogenase deficiency as they are located on different chromosomes however a few people have had both of these metabolic diseases
the 774 – 775 carbon 14 spike is an observed increase of 1 2 in the concentration of carbon 14 isotope in tree rings dated to the years 774 or 775 ce which is about 20 times as high as the normal background rate of variation it was discovered during a study of japanese cedar trees with the year of occurrence determined through dendrochronology a surge in beryllium isotope 10 be detected in antarctic ice cores has also been associated with the 774 – 775 event the event appears to have been global with the same carbon 14 signal found in tree rings from germany russia the united states and new zealand a red crucifix was recorded by the anglo saxon chronicle as appearing in the skies of britain for the year 774 since no supernova remnant has been found for this year it is interpreted as an aurora borealis in china there are no clear references to an aurora in the mid 770 s ce as happened on 762 and comet sightings of the 770 s do not match the expected atmospheric phenomena instead an anomalous thunderstorm was recorded for 775 the signal exhibits a sharp increase of 1 2 followed by a slow decline see figure 1 which is typical for an instant production of carbon 14 in the atmosphere indicating that the event was short in duration the globally averaged production of carbon 14 for this event is calculated as q 1 1 1 5 × 108 atoms cm 2
8 p 23 1 duplication syndrome is a rare genetic disorder caused by a duplication of a region from human chromosome 8 this duplication syndrome has an estimated prevalence of 1 in 64 000 births and is the reciprocal of the 8 p 23 1 deletion syndrome the 8 p 23 1 duplication is associated with a variable phenotype including one or more of speech delay developmental delay mild dysmorphism with prominent forehead and arched eyebrows and congenital heart disease chd
the 993 – 994 carbon 14 spike was a rapid increase in carbon 14 content from tree rings and followed the 774 – 775 carbon 14 spike it may have come from a massive solar storm
9 q 34 deletion syndrome also known as kleefstra syndrome is a rare genetic disorder terminal deletions of chromosome 9 q 34 have been associated with childhood hypotonia a distinctive facial appearance and developmental disability the facial features typically described include arched eyebrows small head circumference midface hypoplasia prominent jaw and a pouting lower lip individuals with this disease may often have speech impediments such as speech delays other characteristics of this disease include epilepsy congenital and urogenetic defects microcephaly corpulence and psychiatric disorders from analysis of chromosomal breakpoints as well as gene sequencing in suggestive cases kleefstra and colleagues identified ehmt 1 as the causative gene this gene is responsible for producing the protein histone methyltransferase which functions to alter histones ultimately histone methyltransferases are important in deactivating certain genes needed for proper growth and development moreover a frameshift missense or nonsense error in the coding sequence of ehmt 1 can result in this condition in an individual
a not b error also known as stage 4 error or perseverative error is a phenomenon uncovered by the work of jean piaget in his theory of cognitive development of children the a not b error is a particular error made by infants during substage 4 of their sensorimotor stage a typical a not b task goes like this an experimenter hides an attractive toy under box a within the baby s reach the baby searches for the toy looks under box a and finds the toy this activity is usually repeated several times always with the researcher hiding the toy under box a then in the critical trial the experimenter moves the toy under box b also within easy reach of the baby babies of 10 months or younger typically make the perseveration error meaning they look under box a even though they saw the researcher move the toy under box b and box b is just as easy to reach this demonstrates a lack of or incomplete schema of object permanence children of 12 months or older typically do not make this error
the a 3 coupling also known as a 3 coupling reaction or the aldehyde alkyne amine reaction is a type of multicomponent reaction involving an aldehyde an alkyne and an amine which react to give a propargyl amine the reaction proceeds via direct dehydrative condensation and requires a metal catalyst typically based on ruthenium copper gold or silver chiral catalyst can be used to give an enantioselective reaction yielding a chiral amine the solvent can be water in the catalytic cycle the metal activates the alkyne to a metal acetylide the amine and aldehyde combine to form an imine which then reacts with the acetylide in an nucleophilic addition the reaction type was independently reported by three research groups in 2001 2002 one report on a similar reaction dates back to 1953
a 3 is a structured problem solving and continuous improvement approach first employed at toyota and typically used by lean manufacturing practitioners it provides a simple and strict approach systematically leading towards problem solving over structured approaches a 3 leads towards problem solving over the structure placed on an iso iso a 3 single sheet paper this is where the process got its name a 3 is also known as sps which stands for systematic problem solving the process is based on the principles of deming s pdca plan do check act
aa amyloidosis is a form of amyloidosis a disease characterized by the abnormal deposition of fibers of insoluble protein in the extracellular space of various tissues and organs in aa amyloidosis the deposited protein is serum amyloid a protein saa an acute phase protein which is normally soluble and whose plasma concentration is highest during inflammation
abcd syndrome is the acronym for albinism black lock cell migration disorder of the neurocytes of the gut and sensorineural deafness it has been found to be caused by mutation in the endothelin b receptor gene ednrb
arterial calcification due to deficiency of cd 73 acdc is a rare genetic disorder that causes calcium buildup in the arteries and joints of the hands and feet and other areas below the waist although patients exhibiting these symptoms have been identified as early as 1914 this disorder had not been studied extensively until recently the identification of the specific acdc gene and mutations occurred in 2011 acdc is caused by a mutation in the nt 5 e gene which prevents calcium removing agents from functioning patients afflicted with this mutation suffer from chronic pain difficulty moving and increased risk of cardiovascular problems in experiments at the molecular level treatment with adenosine or a phosphatase inhibitor reversed and prevented calcification suggesting they could be used as possible treatment methods there is currently no cure for acdc and patients have limited treatment options which focus primarily on removal of blood calcium and improving mobility
acr score is a scale to measure change in rheumatoid arthritis symptoms it is named after the american college of rheumatology different degrees of improvement are referred to as acr 20 acr 50 acr 70 the acr score is more often used in clinical trials than in doctor patient relationships as it allows a common standard between researchers the rheumatoid arthritis severity scale rass is based on sections of the acr scoring system the 2010 acr eular rheumatoid arthritis classification criteria which includes anti ccp testing has been developed to focus on early disease and on features that are associated with persistent or erosive disease
aids related complex or arc was introduced after discovery of the hiv human immunodeficiency virus when the medical community became aware of the inherent difficulties associated with treating patients suffering from an advanced case of hiv which gave rise to the term acquired immune deficiency syndrome aids the necessity for doctors to quickly and accurately understand the special needs of unknown patients suffering from aids in an emergency room situation was addressed with the creation of the term arc arc is a prodromal phase of infection with the human immunodeficiency virus hiv laboratory criteria separating aids related complex arc from aids include elevated or hyperactive b cell humoral immune responses compared to depressed or normal antibody reactivity in aids follicular or mixed hyperplasia in arc lymph nodes leading to lymphocyte degeneration and depletion more typical of aids evolving succession of histopathological lesions such as localization of kaposi s sarcoma signaling the transition to the full blown aids clinical use of this term was widely discontinued by the year 2000 in the united states after having been replaced by modern laboratory criteria
aids related lymphoma describes lymphomas occurring in patients with acquired immunodeficiency syndrome aids a lymphoma is a type of cancer arising from lymphoid cells in aids the incidences of non hodgkin s lymphoma primary cerebral lymphoma and hodgkin s disease are all increased there are three different varieties of aids related lymphoma diffuse large b cell lymphoma b cell immunoblastic lymphoma and burkitt s lymphoma small non cleaved cell lymphoma
aids fatigue is a phenomenon wherein individuals or societies who had been concerned about the impact of hiv or aids become desensitized to the having a strong emotional response to hiv issues after receiving continual messages about the danger over a long period of time
an alpsa anterior labral periosteal sleeve avulsion lesion is an injury at the front of the shoulder associated with shoulder dislocation
amyloid light chain al amyloidosis primary systemic amyloidosis psa or just primary amyloidosis is the most common form of systemic amyloidosis in the us the disease is caused when a person s antibody producing cells do not function properly and produce abnormal protein fibers made of components of antibodies called light chains these light chains come together to form amyloid deposits in different organs which can cause serious damage to these organs abnormal light chains in blood and urine are sometimes referred to as bence jones protein
another syndrome consists of alopecia nail dystrophy ophthalmic complications thyroid dysfunction hypohidrosis ephelides and enteropathy and respiratory tract infections this is an autosomal recessive variant of ectodermal dysplasia
aredyld stands for acral renal ectodermal dysplasia lipoatrophic diabetes aredlyd is categorized as a rare disease meaning it affects fewer than 200 000 people in the american population at any given time it was characterized in 1983 a second case was identified in 1992
the ascii ribbon campaign was an internet phenomenon started in 1998 advocating that email be sent only in plain text because of inefficiencies or dangers of using html email proponents placed ascii art in their signature blocks meant to look like an awareness ribbon along with a message or link to an advocacy site
the as 7007 incident was a major disruption of the internet on april 25 1997 that started with a router operated by autonomous system 7007 mai network services although sometimes incorrectly attributed to the florida internet exchange accidentally leaking a substantial part of its entire route table to the internet creating a routing black hole probably because of a bug in the affected router the routes leaked were deaggregated to 24 prefixes which were more specific than the routes originally present on the internet and had the as path rewritten to 7007 leading the border gateway protocol bgp used by the internet s routers to prefer the leaked routes this was then exacerbated by other problems that prevented the routes from disappearing from other networks routing tables even after the original router that had sent them had been disconnected the combination of these factors resulted in an extended disruption of operations throughout the internet analysis of this event led to major changes in internet service providers bgp operations intended to mitigate the effects of any subsequent similar events
atp hydrolysis is the reaction by which chemical energy that has been stored in the high energy phosphoanhydride bonds in adenosine triphosphate atp is released for example in muscles by producing work in the form of mechanical energy the product is adenosine diphosphate adp and an inorganic phosphate orthophosphate pi adp can be further hydrolyzed to give energy adenosine monophosphate amp and another orthophosphate pi atp hydrolysis is the final link between the energy derived from food or sunlight and useful work such as muscle contraction the establishment of electrochemical gradients across membranes and biosynthetic processes necessary to maintain life the description and typical textbook labeling anhydridic bonds as high energy bonds can be very misleading to students these bonds are in fact relatively weak they do involve high energy electrons but the bonds themselves are quite easy to break as noted below energy is released by the hydrolysis of atp when these weak bonds are broken requiring a small input of energy followed by the formation of new bonds and the release of a larger amount of energy as the total energy of the system is lowered and becomes more stable hydrolysis of the phosphate groups in atp is especially exergonic because the resulting orthophosphate group is greatly stabilized by multiple resonance structures making the products adp and pi much lower in energy than the reactant atp the high negative charge density associated with the three adjacent phosphate units of atp also destabilizes the molecule making it higher in energy hydrolysis relieves some of these electrostatic repulsions liberating useful energy in the process by causing conformational changes in enzyme structure hydrolysis of the terminal phosphoanhydridic bond is a highly exergonic process releasing 30 5 kj mol − 1 energy this reaction can then be coupled with thermodynamically unfavorable reactions to give an overall negative spontaneous δg for the reaction sequence the actual value of δg for atp hydrolysis varies primarily depending on mg 2 concentration and under normal physiologic conditions is actually closer to 50 kj mol − 1 in humans approximately 60 percent of the energy released from the hydrolysis of one mole of atp produces metabolic heat rather than fuel the actual reactions taking place due to the acid base properties of atp adp and inorganic phosphate the hydrolysis of atp has the effect of lowering the ph of the reaction medium under certain conditions high levels of atp hydrolysis can contribute to lactic acidosis
atr 16 syndrome also called alpha thalassemia intellectual disability syndrome is a rare disease characterized by monosomy on part of chromosome 16
av or arteriovenous nicking also known as arteriovenous nipping in the uk is the phenomenon where on examination of the eye a small artery arteriole is seen crossing a small vein venule which results in the compression of the vein with bulging on either side of the crossing this is most commonly seen in eye disease caused by high blood pressure hypertensive retinopathy it is thought that since the arteriole and venule share a common sheath the arteriole s thicker walls push against those of the venule forcing the venule to collapse this makes the venule form an hourglass shape around the arteriole other theories suggest that this results not from compression from the arteriole but from sclerotic thickening or glial cell proliferation at the site where the two vessels cross
av nodal reentrant tachycardia avnrt or atrioventricular nodal reentrant tachycardia is a type of tachycardia fast rhythm of the heart it is a type of supraventricular tachycardia svt meaning that it originates from a location within the heart above the bundle of his av nodal reentrant tachycardia is the most common regular supraventricular tachycardia it is more common in women than men approximately 75 of cases occur in females the main symptom is palpitations treatment may be with specific physical maneuvers medication or rarely synchronized cardioversion frequent attacks may require radiofrequency ablation in which the abnormally conducting tissue in the heart is destroyed avnrt occurs when a reentry circuit forms within or just next to the atrioventricular node the circuit usually involves two anatomical pathways the fast pathway and the slow pathway which are both in the right atrium the slow pathway which is usually targeted for ablation is located inferior and slightly posterior to the av node often following the anterior margin of the coronary sinus the fast pathway is usually located just superior and posterior to the av node these pathways are formed from tissue that behaves very much like the av node and some authors regard them as part of the av node the fast and slow pathways should not be confused with the accessory pathways that give rise to wolff parkinson white syndrome wpw syndrome or atrioventricular reciprocating tachycardia avrt in avnrt the fast and slow pathways are located within the right atrium close to or within the av node and exhibit electrophysiologic properties similar to av nodal tissue accessory pathways that give rise to wpw syndrome and avrt are located in the atrioventricular valvular rings they provide a direct connection between the atria and ventricles and have electrophysiologic properties similar to ventricular myocardium
a calorie is a calorie is a tautology used to convey the speaker s conviction that the concept of the calorie is in fact a sufficient way to describe energy content of food it has been a commonly cited truism since the early 1960 s the tautological phrase means that regardless of the form of food calorie a person consumes whether a carbohydrate protein or fat calorie the energy chemically extracted from the food or the work necessary to burn such a calorie is identical to any other one dietary calorie contains 4184 kilojoules of energy with this knowledge it is easy to assume that all calories have equal value
aagenaes syndrome is a syndrome characterised by congenital hypoplasia of lymph vessels which causes lymphedema of the legs and recurrent cholestasis in infancy and slow progress to hepatic cirrhosis and giant cell hepatitis with fibrosis of the portal tracts the genetic cause is unknown but it is autosomal recessively inherited and the gene is located to chromosome 15 q 1 2 a common feature of the condition is a generalised lymphatic anomaly which may be indicative of the defect being lymphangiogenetic in origin 1 the condition is particularly frequent in southern norway where more than half the cases are reported from but is found in patients in other parts of europe and the u s it is named after oystein aagenaes a norwegian paediatrician it is also called cholestasis lymphedema syndrome cls
aaron s sign is a referred pain felt in the epigastrium upon continuous firm pressure over mcburney s point it is indicative of appendicitis aaron s sign is named for charles dettie aaron an american gastroenterologist
aarskog – scott syndrome is a rare disease inherited as autosomal dominant or x linked and characterized by short stature facial abnormalities skeletal and genital anomalies the aarskog – scott syndrome aas is also known as the aarskog syndrome faciodigitogenital syndrome shawl scrotum syndrome and faciogenital dysplasia
aase syndrome or aase – smith syndrome is a rare inherited disorder characterized by anemia with some joint and skeletal deformities aase syndrome is thought to be an autosomal recessive inherited disorder the genetic basis of the disease is not known the anemia is caused by underdevelopment of the bone marrow which is where blood cells are formed it is named after the american paediatricians jon morton aase and david weyhe smith who characterized it in 1968
abandoned child syndrome is a behavioral or psychological condition that results primarily from the loss of one or both parents or sexual abuse abandonment may be physical the parent is not present in the child s life or emotional the parent withholds affection nurturing or stimulation parents who leave their children with or without good reason can cause psychological damage to the child this damage is reversible but only with appropriate assistance abandoned children may also often suffer physical damage from neglect malnutrition starvation and abuse abandonment experiences and boundary violations are in no way indictments of a child s innate goodness and value instead they reveal the flawed thinking false beliefs and impaired behaviors of those who hurt them still the wounds are struck deep in their young hearts and minds and the very real pain can still be felt today the causes of emotional injury need to be understood and accepted so they can heal until that occurs the pain will stay with them becoming a driving force in their adult lives the abandoned child syndrome is not recognized as a mental disorder in any of the medical manuals such as the icd 10 or the dsm iv neither is it part of the proposed revision of this manual the dsm 5
abarognosis origin greek a not baros weight gnosis knowledge is type of cortical sensory defect consisting of a loss of barognosis the ability to detect the weight of an object held in the hand or to tell the difference in weight between two objects or more succinctly loss of the ability to sense weight this deficit may be caused by damage to the parietal lobe this condition is also known as baragnosis and baroagnosis
an abbott artery is a minor congenital abnormality in which there is an anomalous artery that arises from the posteromedial aspect of the proximal descending aorta its presence is important during the surgical repair of coarctation of the aorta
abdallat – davis – farrage syndrome is a form of phakomatosis a disease of the central nervous system accompanied by skin abnormalities it is characterized by the out of the ordinary pigment of skin that is abnormal to one s genetics or the color perceived on a basis the condition is named after the team of medical professionals who first wrote it up describing the appearance of the syndrome in a family from jordan it was characterized in 1980 by adnan abdallat a jordanian doctor the syndrome is thought to be inherited as an autosomal recessive genetic trait meaning that in order to manifest symptoms a person must inherit a gene for abdallat – davis – farrage syndrome from both parents as it is also autosomal not linked to either of the genes that determine gender it can manifest in both men and women those with only one gene are carriers and they typically manifest no symptoms in the event that a person inherits both genes symptoms usually appear before one year of age
abderhalden – kaufmann – lignac syndrome akl syndrome also called abderhalden lignac kaufmann disease or nephropathic cystinosis is an autosomal recessive renal disorder of childhood comprising cystinosis and renal rickets
abdominal angina is abdominal pain after eating that occurs in individuals with ongoing poor blood supply to their small intestines known as chronic mesenteric ischemia the term angina is used in reference to angina pectoris a similar symptom due to obstruction of the coronary artery the american heritage stedman s medical dictionary defines abdominal angina as intermittent abdominal pain frequently occurring at a fixed time after eating caused by inadequacy of the mesenteric circulation also called intestinal angina
abdominal aortic aneurysm aaa is a localized enlargement of the abdominal aorta such that the diameter is greater than 3 cm or more than 50 larger than normal diameter they usually cause no symptoms except when ruptured occasionally abdominal back or leg pain may occur large aneurysms can sometimes be felt by pushing on the abdomen rupture may result in pain in the abdomen or back low blood pressure or loss of consciousness and often results in death aaas occur most commonly in those over 50 years old in men and among those with a family history additional risk factors include smoking high blood pressure and other heart or blood vessel diseases genetic conditions with an increased risk include marfan syndrome and ehlers danlos syndrome aaas are the most common form of aortic aneurysm about 85 occur below the kidneys with the rest either at the level of or above the kidneys in the united states screening with ultrasound is recommended for males between 65 and 75 years of age with a history of smoking in the united kingdom screening all men over 65 is recommended once an aneurysm is found further ultrasounds are typically done on a regular basis not smoking is the single best way to prevent the disease other methods of prevention include treating high blood pressure treating high blood cholesterol and not being overweight surgery is usually recommended when an aaa s diameter grows to 5 5 cm in males and 5 0 cm in females other reasons for repair include the presence of symptoms and a rapid increase in size more than one centimeter per year repair may be either by open surgery or endovascular aneurysm repair evar as compared to open surgery evar has a lower risk of death in the short term and a shorter hospital stay but may not always be an option there does not appear to be a difference in longer term outcomes between the two with evar there is a higher need for repeat procedures aaas affect between 2 and 8 of males over the age of 65 rates among women are one fourth as high in those with an aneurysm less than 5 5 cm the risk of rupture in the next year is less than 1 among those with an aneurysm between 5 5 and 7 cm the risk is about 10 while for those with an aneurysm greater than 7 cm the risk is about 33 mortality if ruptured is 85 to 90 during 2013 aortic aneurysms resulted in 152 000 deaths up from 100 000 in 1990 in the united states aaas resulted in between 10 000 and 18 000 deaths in 2009
abdominal compartment syndrome occurs when the abdomen becomes subject to increased pressure specific cause of abdominal compartment syndrome is not known although some causes can be sepsis and severe abdominal trauma increasing pressure reduces blood flow to abdominal organs and impairs pulmonary cardiovascular renal and gastro intestinal gi function causing multiple organ dysfunction syndrome and death
abdominal epilepsy also known as autonomic epilepsy is a rare condition most frequently found in children consisting of gastrointestinal gi disturbances caused by epileptiform seizure activity it has been described as a type of temporal lobe epilepsy responsiveness to anticonvulsants can aid in the diagnosis most published medical literature dealing with abdominal epilepsy is in the form of individual case reports a 2005 review article found a total of 36 cases described in the medical literature
an abdominal mass is any localized enlargement or swelling in the human abdomen depending on its location the abdominal mass may be caused by an enlarged liver hepatomegaly enlarged spleen splenomegaly protruding kidney a pancreatic mass a retroperitoneal mass a mass in the posterior of the peritoneum an abdominal aortic aneurysm or various tumours such as those caused by abdominal carcinomatosis and omental metastasis the treatments depend on the cause and may range from watchful waiting to radical surgery
abdominal migraine is a disorder primarily of children which presents with episodes of abdominal pain without an accompanying headache it is difficult to confirm the diagnosis as there are not a set of features that is specific and thus it can take time before the diagnosis is made the condition is rare in adults
abdominal musculature absent with microphthalmia and joint laxity is a rare human disorder characterized mainly by ligamentous laxity small eyes a lack of abdominal muscles and facial anomalies
abdominal obesity also known as central obesity is when excessive abdominal fat around the stomach and abdomen has built up to the extent that it is likely to have a negative impact on health there is a strong correlation between central obesity and cardiovascular disease abdominal obesity is not confined only to the elderly and obese subjects abdominal obesity has been linked to alzheimer s disease as well as other metabolic and vascular diseases visceral and central abdominal fat and waist circumference show a strong association with type 2 diabetes visceral fat also known as organ fat or intra abdominal fat is located inside the peritoneal cavity packed in between internal organs and torso as opposed to subcutaneous fat ‚ which is found underneath the skin and intramuscular fat ‚ which is found interspersed in skeletal muscle visceral fat is composed of several adipose depots including mesenteric epididymal white adipose tissue ewat and perirenal fat an excess of visceral fat is known as central obesity the pot belly or beer belly effect in which the abdomen protrudes excessively this body type is also known as apple shaped ‚ as opposed to pear shaped ‚ in which fat is deposited on the hips and buttocks researchers first started to focus on abdominal obesity in the 1980 s when they realized that it had an important connection to cardiovascular disease diabetes and dyslipidemia abdominal obesity was more closely related with metabolic dysfunctions connected with cardiovascular disease than was general obesity in the late 1980 s and early 1990 s insightful and powerful imaging techniques were discovered that would further help advance the understanding of the health risks associated with body fat accumulation techniques such as computed tomography and magnetic resonance imaging made it possible to categorize mass of adipose tissue located at the abdominal level into intra abdominal fat and subcutaneous fat
abdominal pain also known as stomach pain is a common symptom associated with both temporary non serious disorders and more serious conditions common causes of pain in the abdomen include gastroenteritis and irritable bowel syndrome in a third of cases the exact cause is unclear about 10 of people have a more serious underlying condition such as appendicitis leaking or ruptured abdominal aortic aneurysm diverticulitis or ectopic pregnancy determining the cause can be difficult because many diseases can cause this symptom
an abdominal pregnancy can be regarded as a form of an ectopic pregnancy where the embryo or fetus is growing and developing outside the womb in the abdomen but not in the fallopian tube ovary or broad ligament while rare abdominal pregnancies have a higher chance of maternal mortality perinatal mortality and morbidity compared to normal and ectopic pregnancies but on occasion a healthy viable infant can be delivered because tubal ovarian and broad ligament pregnancies are as difficult to diagnose and treat as abdominal pregnancies their exclusion from the most common definition of abdominal pregnancy has been debated others in the minority are of the view that abdominal pregnancy should be defined by a placenta implanted into the peritoneum
abdominal trauma is an injury to the abdomen it may be blunt or penetrating and may involve damage to the abdominal organs signs and symptoms include abdominal pain tenderness rigidity and bruising of the external abdomen abdominal trauma presents a risk of severe blood loss and infection diagnosis may involve ultrasonography computed tomography and peritoneal lavage and treatment may involve surgery injury to the lower chest may cause splenic or liver injuries
abdominal wall defects are a type of congenital defect that allows the stomach the intestines or other organs to protrude through an unusual opening that forms on the abdomen during the development of the fetus many unexpected changes occur inside the womb specifically the stomach intestines or other organs begin to develop outside the fetus ’ abdomen through the abnormal hole in the abdomen and as development progresses the abdominal wall eventually encloses these organs in some cases of defect either the umbilical opening is too oversized or has developed improperly which allows the organs to remain outside or to squeeze through the abdominal wall there are two main types of abdominal wall defects that result due to the changes during development they are omphalocele and gastroschisis gastroschisis develops when the abdominal wall does not completely close and the organs are present outside of the infant ’ s body omphalocele occurs when some of the organs protrude through the muscles of the abdomen in the area surrounding the umbilical cord omphalocele can be either minor with only some of the organs exposed or severe with most if not all of the abdominal organs being exposed
the abelin reaction is a qualitative reaction for demonstrating the presence of arsphenamine and neoarsphenamine in blood and urine it is named for issak abelin swiss physiologist
abell 2142 or a 2142 is a huge x ray luminous galaxy cluster in the constellation corona borealis it is the result of a still ongoing merger between two galaxy clusters the combined cluster is six million light years across contains hundreds of galaxies and enough gas to make a thousand more it is one of the most massive objects in the universe
the aberdeen hospital is a 24 hour emergency level ii trauma service inpatient outpatient and community based services hospital in new glasgow nova scotia the hospital has been in existence since 1895 it serves approximately 48 000 people in pictou county nova scotia it located at 835 east river road route 348 new glasgow it is operated by pictou county health authority the hospital currently has 104 beds internationally renowned sculptor john wilson donated to the hospital the land on which the glen haven manor was built
the aberfan disaster was the catastrophic collapse of a colliery spoil tip in the welsh village of aberfan near merthyr tydfil that killed 116 children and 28 adults on 21 october 1966 the collapse was caused by the build up of water in the accumulated rock and shale tip which suddenly slid downhill in the form of slurry more than 1 4 million cubic feet 40 000 cu metres of debris covered the village in minutes the classrooms at pantglas junior school were immediately inundated young children and teachers died from impact or suffocation many noted the poignancy of the situation if the disaster had struck a few minutes earlier the children would not have been in their classrooms and if it had struck a few hours later they would have left for the half term holiday rescue efforts were hampered by the large crowd who rushed into the village delaying the arrival of mines rescue workers from merthyr vale colliery the official inquiry blamed the national coal board for extreme negligence and its chairman lord robens for making misleading statements parliament passed new legislation regarding public safety in relation to mines and quarries
aberrant subclavian artery or aberrant subclavian artery syndrome is a rare anatomical variant of the origin of the right or left subclavian artery this abnormality is the most common congenital vascular anomaly of the aortic arch
the aberration of light also referred to as astronomical aberration or stellar aberration is an astronomical phenomenon which produces an apparent motion of celestial objects about their locations dependent on the velocity of the observer aberration causes objects to appear to be angled or tilted towards the direction of motion of the observer compared to when the observer is stationary the change in angle is typically very small on the order of v c where c is the speed of light and v the velocity of the observer in the case of stellar or annual aberration the apparent position of a star to an observer on earth varies periodically over the course of a year as the earth s velocity changes as it revolves around the sun by a maximum angle of approximately 20 arcseconds in right ascension or declination aberration is historically significant because of its role in the development of the theories of light electromagnetism and ultimately the theory of special relativity it was first observed in the late 1600 s by astronomers searching for stellar parallax in order to confirm the heliocentric model of the solar system however it was not understood at the time to be a different phenomenon in 1727 james bradley provided a classical explanation for it in terms of the finite speed of light relative to the motion of the earth in its orbit around the sun which he used to make one of the earliest measurements of the speed of light however bradley s theory was incompatible with 19 th century theories of light and aberration became a major motivation for the aether drag theories of augustin fresnel in 1818 and g g stokes in 1845 and for hendrick lorentz s aether theory of electromagnetism in 1892 the aberration of light together with lorentz s elaboration of maxwell s electrodynamics the moving magnet and conductor problem the negative aether drift experiments as well as the fizeau experiment led albert einstein to develop the theory of special relativity in 1905 which provided a conclusive explanation for the aberration phenomenon the term aberration has historically been used to refer to a number of related phenomena concerning the propagation of light in moving bodies aberration should not be confused with stellar parallax the latter is caused by a change in the positions of relatively nearby objects measured by the moving observer assuming far away objects do not move so they define a reference frame the former is related to light time correction and relativistic beaming although it is often considered separately from these effects the term aberration may also be used to refer to unrelated phenomena in optical systems — optical aberration
abetalipoproteinemia or bassen kornzweig syndrome is a rare autosomal recessive disorder that interferes with the normal absorption of fat and fat soluble vitamins from food it is caused by a mutation in microsomal triglyceride transfer protein resulting in deficiencies in the apolipoproteins b 48 and b 100 which are used in the synthesis and exportation of chylomicrons and vldl respectively it is not to be confused with familial dysbetalipoproteinemia
abhimāna sanskrit अभिमान variously means – pride false prestige desire an impression the conception by self conception from the misconception in hindu philosophy it means – prideful attachment of i sense i e man to think māna too much it also means – identify or identification and also refers to selfish conviction for abhimāna is the function of ahamkara ego as the state of mind which interprets experience as mine the psychological sense of i am experience is ahamkāra which comes about as and when owing to avidya brahman the universal transcendental self is distinguished from the jiva the empirical individual self sanga one ’ s associations mamkāra attachments and moha attractions are the three aspects of abhimāna ego consciousness which produces katrtva the sense agency as the deliberate consciousness of niścaya decision without which there would be no difference between the self and other material objects buddhi intellect which manifests according to vāsanās impressions is deliberate decision अन्तःकरणमेतेषु चक्षुरादिषु वर्ष्मणि अहमित्यभिमानेन तिष्ठत्याभासतेजसा the antahkarana internal organ the mind has its seat in these the eye and other organs of the body identifying itself with them with the sense of i by reflection of the ātman in it – vivekachudamani 105 shankara tells us that the mind or manas dwells in the organs and body as aham ego with abhimāna – अहमित्यभिमानेन in the reflected brightness of the atman as the kartā doer and the bhoktā enjoyer experiencing all three states of consciousness but the atman the witness of everything limited by buddhi is not tainted by anything that buddhi does – अशेषसाक्षी for the taint of action attaches only to the actor the ātman does not act this abhimāna or identification with names and forms dependent on the perishable body as also with the subtle body needs to be given up entirely in order to realize akhanda ānanda inseparable bliss vācaspati miśra explains that it is ahamkāra empirical ego which presides over the objects intuited by the sense organs and then definitely perceived by the mind and that the sense organ intuits the object manas reflects on it ahamkāra appropriates it and finally buddhi intellect resolves which way the intended action must proceed abhimāna is the false sense of i and mine it is because of the emphatic identity abhimāna with one ’ s body etc that there is pramata cognising subject and involvement with pramānas acts or processes of knowing perception inference and the rest owing to functioning of the senses as resulting from avidyā ignorance and resulting in bondage examined from the level of social consciousness ātman or the transcendental consciousness is certainly essential for man ’ s being but upadhis limitations are its accidental parts the self identification with which gives rise to abhimāna identification with the body that makes man a socio spiritual being subjective and objective both and becomes the basis for his adhikāra social and ritual eligibility according to the shudha advaita school of vallabha acharya saguna means – one having the abhimāna of gunas forming part of one ’ s own self the nirguna is one having no abhimāna the lakshmi tantra tells us that ahamkāra which is a cognitive sense is identical with abhimāna and the awareness of the knower in relating time and place to himself is called abhimāna for most people desiring success incidental gains and weighed down by sense of self respect abhimāna is a virtue but for those who are wise and contented it is mere pride associated with arrogance bhoja who outlined the theory of rasa experience of delight attaches great importance to abhimāna or ahankāra ego he states that the rasika who has rasa in him has it because of sringara peak ahamkāra and abhimāna enjoyable as a guna of his atman he uses the term abhimāna in a good sense from ahamkāra rises abhimāna that originates sringāra and from abhimāna rises rati love amorousness and from rati are originated all rasas
abietic acid dermatitis is a contact dermatitis often seen in association with musical instruments
abnormal or discontinuous grain growth also referred to as exaggerated or secondary recrystallisation grain growth is a grain growth phenomenon through which certain energetically favorable grains crystallites grow rapidly in a matrix of finer grains resulting in a bimodal grain size distribution in ceramic materials this phenomena can result in the formation of elongated prismatic acicular or needle like grains in a densified matrix with implications for improved fracture toughness through the impedance of crack propagation
abnormal posturing is an involuntary flexion or extension of the arms and legs indicating severe brain injury it occurs when one set of muscles becomes incapacitated while the opposing set is not and an external stimulus such as pain causes the working set of muscles to contract the posturing may also occur without a stimulus since posturing is an important indicator of the amount of damage that has occurred to the brain it is used by medical professionals to measure the severity of a coma with the glasgow coma scale for adults and the pediatric glasgow coma scale for infants the presence of abnormal posturing indicates a severe medical emergency requiring immediate medical attention decerebrate and decorticate posturing are strongly associated with poor outcome in a variety of conditions for example near drowning victims that display decerebrate or decorticate posturing have worse outcomes than those that do not changes in the condition of the patient may cause him or her to alternate between different types of posturing
in finance an abnormal return is the difference between the actual return of a security and the expected return abnormal returns are sometimes triggered by events events can include mergers dividend announcements company earning announcements interest rate increases lawsuits etc all of which can contribute to an abnormal return events in finance can typically be classified as information or occurrences that have not already been priced by the market
abortion is the ending of pregnancy by removing a fetus or embryo before it can survive outside the uterus an abortion which occurs spontaneously is also known as a miscarriage an abortion may be caused purposely and is then called an or less frequently induced miscarriage the word abortion is often used to mean only induced abortions a similar procedure after the fetus could potentially survive outside the womb is known as a late termination of pregnancy when allowed by local law abortion in the developed world is modern methods use medication or surgery for abortions the drug mifepristone in combination with prostaglandin appears to be as safe and effective as surgery during the first and second trimester of pregnancy birth control such as the pill or intrauterine devices can be used immediately following abortion when performed legally and safely induced abortions do not increase the risk of long term mental or physical problems in contrast unsafe abortions cause 47 000 deaths and 5 million hospital admissions each year the world health organization recommends safe and legal abortions be available to all women around 56 million abortions occur each year in the world with a little under half done unsafely abortion rates changed little between 2003 and 2008 before which they decreased for at least two decades as access to family planning and birth control increased as of 2008 40 of the world s women had access to legal abortions without limits as to reason countries that permit abortions have different limits on how late in pregnancy abortion is allowed since ancient times abortions have been done using herbal medicines sharp tools with force or through other traditional methods abortion laws and cultural or religious views of abortions are different around the world in some areas abortion is legal only in specific cases such as rape problems with the fetus poverty risk to a woman s health or incest in many places there is much debate over the moral ethical and legal issues of abortion those who oppose abortion often maintain that an embryo or fetus is a human with a right to life and may compare abortion to murder those who favor the legality of abortion often hold that a woman has a right to make decisions about her own body
an abortion performed by a physician or other trained health professional who has the consent of the woman or her spouse partner intimate family member or legal representative when she is not able to lend her consent is not punishable in the following cases 1 if it the abortion has been provided to avoid danger to life or health of the pregnant woman and if this danger can not be avoided by other means 2 if the pregnancy is a consequence of a rape of a woman who is suffering from a mental disability taken directly verbatim from the latest guidelines on therapeutic abortion set forth by the ministry of public health 20 november 2014
abortion in uganda is generally illegal however it is permissible if performed by a doctor who believes pregnancy places the woman s life at risk the ugandan ministry of health estimates that as of 2008 26 of all maternal deaths are of abortion related causes this is aggravated by legal socioeconomic and geographical barriers to safe abortion which compel women to use unsafe abortion methods and deter them from seeking post abortion medical care contraception is not commonly used leading to uganda ’ s unmet need for family planning which is the second highest in the world after samoa according to the united nations
aboulomania from greek a – meaning without and boulē meaning will is a mental disorder in which the patient displays pathological indecisiveness it is typically associated with anxiety stress depression and mental anguish and can severely affect one ’ s ability to function socially although many people suffer from indecision it is rarely to the extent of obsession the part of the brain that is tied to making rational choices the prefrontal cortex can hold several pieces of information at any given time this may quickly overwhelm somebody when trying to make decisions regardless of the importance of that decision they come up with reasons that their decisions will turn out badly causing them to over analyze every situation critically in a classic case of paralysis by analysis lack of information valuation difficulty and outcome uncertainty become an obsession
abrasion is the loss of tooth structure by mechanical forces from a foreign element if this force begins at the cementoenamel junction then progression of tooth loss can be rapid since enamel is very thin in this region of the tooth once past the enamel abrasion quickly destroys the softer dentin and cementum structures possible sources of this wearing of tooth are toothbrushes toothpicks floss and any dental appliance frequently set in and removed from the mouth the appearance is commonly described as v shaped when caused by excessive pressure during tooth brushing abrasion is seen at a cervical necks of the teeth as a deep ridge on the buccal or labial surfaces the surface is shiny rather than carious and sometimes the ridge is deep enough to see the pulp chamber within the tooth itself the teeth most commonly affected are premolars and canines
some characteristics of abruzzo – erickson syndrome include deafness protruding ears coloboma a cleft palate or palatal rugosity and short stature it was characterized in 1977
an abscess latin abscessus is a collection of pus that has built up within the tissue of the body signs and symptoms of abscesses include redness pain warmth and swelling the swelling may feel fluid filled when pressed the area of redness often extends beyond the swelling carbuncles and boils are types of abscess that often involve hair follicles with carbuncles being larger they are usually caused by a bacterial infection often many different types of bacteria are involved in a single infection in the united states and many other areas of the world the most common bacteria present is methicillin resistant staphylococcus aureus rarely parasites can cause abscesses and this is more common in the developing world diagnosis of a skin abscess is usually made based on what it looks like and is confirmed by cutting it open ultrasound imaging may be useful in cases in which the diagnosis is not clear in abscesses around the anus computer tomography ct may be important to look for deeper infection standard treatment for most skin or soft tissue abscesses is cutting it open and drainage there does not appear to be any benefit from also using antibiotics for this type of abscess in most people who are otherwise healthy a small amount of evidence supports not packing the cavity that remains with gauze after drainage closing this cavity right after draining it rather than leaving it open may speed healing without increasing the risk of the abscess returning sucking out the pus with a needle is often not sufficient skin abscesses are common and have become more common in recent years risk factors include intravenous drug use with rates reported as high as 65 in this population in 2005 in the united states 3 2 million people went to the emergency department for an abscess in australia around 13 000 people were hospitalized in 2008 with the condition
an abscess of the thymus also known as dubois abscesses is a condition that is one of many possible causes of cysts in the mediastinum it can present with chest pain behind the sternum it can be associated with congenital syphilis although the thymus is usually classified with the immune system thymic diseases are classified with endocrine disorders in icd 9 and icd 10
abscission from the latin ab meaning away and scindere meaning to cut is the shedding of various parts of an organism such as a plant dropping a leaf fruit flower or seed in zoology abscission is the intentional shedding of a body part such as the shedding of a claw husk or the autotomy of a tail to evade a predator in mycology it is the liberation of a fungal spore in cell biology abscission refers to the separation of two daughter cells at the completion of cytokinesis
the abscopal effect is a phenomenon in the treatment of metastatic cancer where localized treatment of a tumor causes not only a shrinking of the treated tumor but also a shrinking of tumors outside the scope of the localized treatment r h mole proposed the term “ abscopal ” ‘ ab ’ away from ‘ scopus ’ target in 1953 to refer to radiation ’ s effects “ at a distance from the irradiated volume but within the same organism ” initially associated with single tumor localized radiation therapy the term has also come to encompass other types of localized treatments such as electroporation and intra tumoral injection of therapeutics while this phenomenon is extremely rare its effect on the cancer can be stunning leading to the disappearance of malignant growths throughout the entire body such success has been described for a variety of cancers including melanoma cutaneous lymphomas and kidney cancer scientists are not certain how the abscopal effect works to eliminate cancer in patients studies in mice suggest that the effect may depend upon activation of the immune system in a case study reported at memorial sloan kettering cancer center in new york city changes in a metastatic melanoma patient ’ s immune system were measured over the course of treatment the team observed changes in tumor directed antibody levels and immune cell populations that occurred at the time of the abscopal effect these findings support the idea that a localized treatment may broadly stimulate the immune system to fight cancer at this time various immune system cells including t cells and dendritic cells are believed to play a primary role effects in tissues adjacent to the irradiated area are bystander effects and are not necessarily mediated by the same mechanisms as abscopal effects
absence seizures are one of several kinds of seizures these seizures are sometimes referred to as petit mal seizures from the french for little illness a term dating from the late 18 th century absence seizures are characterized by a brief loss and return of consciousness generally not followed by a period of lethargy without a notable postictal state
absent adrenal gland is a rare condition where the adrenal gland is absent at birth it should not be confused with adrenal insufficiency or congenital adrenal hyperplasia where the gland is present but may not be functioning adequately due to the absence of adrenal cortex the condition causes extreme symptoms of adrenal insufficiency at birth due to very low levels of aldosterone and cortisol the adrenal medulla can be normally present poorly formed or absent however even so the effects of circulatory catecholamine deficiency are generally mild due to sympathetic nervous system compensation except in episodes of hypoglycemia
absenteeism is a habitual pattern of absence from a duty or obligation traditionally absenteeism has been viewed as an indicator of poor individual performance as well as a breach of an implicit contract between employee and employer it was seen as a management problem and framed in economic or quasi economic terms more recent scholarship seeks to understand absenteeism as an indicator of psychological medical or social adjustment to work
in phonology absolute neutralization is a phenomenon in which a segment of the underlying representation of a morpheme is not realized in any of its phonetic representations surface forms the term was introduced by paul kiparsky 1968 and contrasts with contextual neutralization which is closer to the traditional form of phonological neutralization for example chomsky halle 1968 assume that the underlying representation of the word ellipse contains a final segment e even though this segment is never pronounced but the assumption of this segment in underlying representation explains the exceptional stress pattern of the word i e that of trisyllabic words instead of that of bisyllabic words i e ellípse instead of éllipse the segment e is deleted after the assignment of stress thus the opposition between e and zero the absence of a segment is neutralized
absolute pitch ap widely referred to as perfect pitch is a rare auditory phenomenon characterized by the ability of a person to identify or re create a given musical note without the benefit of a reference tone ap can be demonstrated via linguistic labeling naming a note auditory imagery or sensorimotor responses for example an ap possessor can accurately reproduce a heard tone on their musical instrument without hunting for the correct pitch researchers estimate the occurrence of ap to be 1 in 10 000 people generally absolute pitch implies some or all of the following abilities achieved without a reference tone identify by name individual pitches e g a g c ♯ played on various instruments name the key of a given piece of tonal music reproduce a piece of tonal music in the correct key days after hearing it identify and name all the tones of a given chord or other tonal mass accurately sing a named pitch name the pitches of common everyday sounds such as car horns and alarms people may have absolute pitch along with the ability of relative pitch and relative and absolute pitch work together in actual musical listening and practice but strategies in using each skill vary those with absolute pitch may train their relative pitch but there are no reported cases of an adult obtaining absolute pitch ability through musical training adults who possess relative pitch but do not already have absolute pitch can learn pseudo absolute pitch and become able to identify notes in a way that superficially resembles absolute pitch moreover training pseudo absolute pitch requires considerable motivation time and effort and learning is not retained without constant practice and reinforcement
in mathematics an absolute value is a function which measures the size of elements in a field or integral domain more precisely if d is an integral domain then an absolute value is any mapping x from d to the real numbers r satisfying x ≥ 0 x 0 if and only if x 0 xy x y x y ≤ x y it follows from these axioms that 1 1 and − 1 1 furthermore for every positive integer n n 1 1 n times − 1 − 1 − n times ≤ n note that some authors use the terms valuation norm or magnitude instead of absolute value however the word norm usually refers to a specific kind of absolute value on a field and which is also applied to other vector spaces the classical absolute value is one in which for example 2 2 but many other functions fulfill the requirements stated above for instance the square root of the classical absolute value but not the square thereof
an absorption edge absorption discontinuity or absorption limit is a sharp discontinuity in the absorption spectrum of a substance these discontinuities occur at wavelengths where the energy of an absorbed photon corresponds to an electronic transition or ionization potential when the quantum energy of the incident radiation becomes smaller than the work required to eject an electron from one or other quantum states in the constituent absorbing atom the incident radiation ceases to be absorbed by that state for example incident radiation on an atom of a wavelength that has a corresponding energy just below the binding energy of the k shell electron in that atom cannot eject the k shell electron
in the field of nuclear engineering absorption hardening is the increase in average energy of neutrons in a population by preferential absorption of lower energy neutrons this occurs because absorption cross sections typically increase for lower neutron energies
abstraction of transport protocol connectivity is the ability to connect to various components or services through multiple protocols without code change or addition via change to a standard configuration file connectivity abstraction may be achieved through a service transport protocol implementation
abuse of process is a cause of action in tort arising from one party making a malicious and deliberate misuse or perversion of regularly issued court process civil or criminal not justified by the underlying legal action it is a common law intentional tort it is to be distinguished from malicious prosecution another type of tort that involves misuse of the public right of access to the courts the elements of a valid cause of action for abuse of process in most common law jurisdictions are as follows 1 the existence of an ulterior purpose or motive underlying the use of process and 2 some act in the use of the legal process not proper in the regular prosecution of the proceedings abuse of process can be distinguished from malicious prosecution in that abuse of process typically does not require proof of malice lack of probable cause in procuring issuance of the process or a termination favorable to the plaintiff all of which are essential to a claim of malicious prosecution process as used in this context includes not only the service of process i e an official summons or other notice issued from a court but means any method used to acquire jurisdiction over a person or specific property that is issued under the official seal of a court typically the person who abuses process is interested only in accomplishing some improper purpose that is collateral to the proper object of the process and that offends justice such as an unjustified arrest or an unfounded criminal prosecution subpoenas to testify attachments of property executions on property garnishments and other provisional remedies are among the types of process considered to be capable of abuse
abusive head trauma aht also known as shaken baby syndrome sbs is a constellation of medical findings often referred to as a triad subdural hematoma retinal bleeding and brain swelling which some physicians have used to infer child abuse caused by violent shaking in a majority of cases there is no visible sign of external injury it is a subset of the broader form of child abuse the centers for disease control and prevention identifies sbs as an injury to the skull or intracranial contents of an infant or young child 5 years of age due to inflicted blunt impact and or violent shaking the crown prosecution service for england and wales recommended in 2011 that the term shaken baby syndrome be avoided and the term non accidental head injury nahi be used instead in 2009 the american academy of pediatrics recommended the use of the term abusive head trauma to replace sbs sbs is often fatal and can cause severe brain damage resulting in lifelong disability estimated death rates mortality among infants with sbs range from 15 to 38 the median is 20 – 25 up to half of deaths related to child abuse are reportedly due to shaken baby syndrome nonfatal consequences of sbs include varying degrees of visual impairment including blindness motor impairment e g cerebral palsy and cognitive impairments
academic publishing is the subfield of publishing which distributes academic research and scholarship most academic work is published in academic journal article book or thesis form the part of academic written output that is not formally published but merely printed up or posted on the internet is often called grey literature most scientific and scholarly journals and many academic and scholarly books though not all are based on some form of peer review or editorial refereeing to qualify texts for publication peer review quality and selectivity standards vary greatly from journal to journal publisher to publisher and field to field most established academic disciplines have their own journals and other outlets for publication although many academic journals are somewhat interdisciplinary and publish work from several distinct fields or subfields there is also a tendency for existing journals to divide into specialized sections as the field itself becomes more specialized along with the variation in review and publication procedures the kinds of publications that are accepted as contributions to knowledge or research differ greatly among fields and subfields academic publishing is undergoing major changes as it makes the transition from the print to the electronic format business models are different in the electronic environment since the early 1990 s licensing of electronic resources particularly journals has been very common currently an important trend particularly with respect to journals in the sciences is open access via the internet in open access publishing a journal article is made available free for all on the web by the publisher at the time of publication it is typically made possible after the author pays hundreds or thousands of dollars in publication fees thereby shifting the costs from the reader to the researcher or their funder the internet has facilitated open access self archiving in which authors themselves make a copy of their published articles available free for all on the web
acalculia not to be confused with dyscalculia is an acquired impairment in which patients have difficulty performing simple mathematical tasks such as adding subtracting multiplying and even simply stating which of two numbers is larger acalculia is distinguished from dyscalculia in that acalculia is acquired late in life due to neurological injury such as stroke while dyscalculia is a specific developmental disorder first observed during the acquisition of mathematical knowledge the name comes from the greek a meaning not and latin calculare which means to count
acalvaria is a rare malformation consisting of absence of the calvarial bones dura mater and associated muscles in the presence of a normal skull base and normal facial bones the central nervous system is usually unaffected the presumed pathogenesis of acalvaria is faulty migration of the membranous neurocranium with normal placement of the embryonic ectoderm resulting in absence of the calvaria but an intact layer of skin over the brain parenchyma in other words instead of having a skull cap protecting the brain there is only skin covering it the size of the area that is missing the skull cap can vary from case to case in extreme cases the entire top part of the cranium that is dome shaped may be absent
acanthamoeba infection is a cutaneous condition resulting from acanthamoeba that may result in various skin lesions acanthamoeba strains can also infect human eyes causing acanthamoebic keratitis
acanthamoeba keratitis is a rare disease in which amoebae invade the cornea of the eye it may result in permanent visual impairment or blindness
acanthocheilonemiasis is a rare tropical infectious disease caused by a parasite known as acanthocheilonema perstans it can cause skin rashes abdominal and chest pains muscle and joint pains neurological disorders and skin lumps it is mainly found in africa the parasite is transmitted through the bite of small flies studies show that there are elevated levels of white blood cells acanthocheilonemiasis belongs to a group of parasitic diseases known as filarial disease nematode all of which are classified as neglected tropical diseases filarial disease results when microfilariae which are nematode larvae reach the lymphatic system microfilariae reside in the serous cavities of humans they have a five stage life cycle that includes birth to thousands of live microfilariae within the host i e human body and then translocation via blood meal to the dermis layer of the skin it is here that microfilariae cause major symptoms which are edema and thickening of the skin and underlying connective tissues it can also cause skin rashes abdominal and chest pains muscle myalgia and joint pains neurological disorders and skin lumps in addition it causes spleen and liver enlargement which is called hepatosplenomegaly studies show elevated levels of leukocytes or white blood cells which is referred to as eosinophilia it is mainly found in africa the parasite is transmitted through the bite of small flies a coliroides
acantholysis is the loss of intercellular connections such as desmosomes resulting in loss of cohesion between keratinocytes seen in diseases such as pemphigus vulgaris it is absent in bullous pemphigoid making it useful for differential diagnosis this histological feature is also seen in herpes simplex infections hsv 1 and 2 and varicella zoster infections chicken pox and shingles
linear darier disease also known as acantholytic dyskeratotic epidermal nevus is a cutaneous condition identical to the generalized form of darier s disease acantholytic dyskeratotic epidermal nevus is probably the same disorder
an acanthoma is a skin neoplasm composed of squamous or epidermal cells it is located in the prickle cell layer types of acanthoma include pilar sheath acanthoma a benign follicular tumor usually of the upper lip clear cell acanthoma a benign tumor found most frequently on the legs and degos acanthoma often confused with but unrelated to degos disease
acanthoma fissuratum also known as granuloma fissuratum and spectacle frame acanthoma is a cutaneous condition characterized by local thickening of the skin in response to pressure caused by an eyeglass frame
acanthosis is diffuse epidermal hyperplasia thickening of the skin it implies increased thickness of the malpighian layer stratum basale and stratum spinosum
acanthosis nigricans is a brown to black poorly defined velvety hyperpigmentation of the skin it is usually found in body folds such as the posterior and lateral folds of the neck the armpits groin navel forehead and other areas
acariasis is an infestation with mites
acatalasia also called acatalasemia or takahara s disease is an autosomal recessive peroxisomal disorder caused by a complete lack of catalase
accelerated idioventricular rhythm is ventricular rhythm with a rate of between 40 and 120 beats per minute idioventricular means “ relating to or affecting the cardiac ventricle alone “ and refers to any ectopic ventricular arrythmia accelerated idioventricular arrhythmias are distinguished from ventricular rhythms with rates less than 40 ventricular escape and those faster than 120 ventricular tachycardia though some other references limit to between 60 and 100 beats per minute it is also referred to as aivr and slow ventricular tachycardia it can be present at birth however it is more commonly associated with reperfusion after myocardial injury
accelerated phase chronic myelogenous leukemia is a phase of chronic myelogenous leukemia in which the disease is progressing in this phase 10 to 19 of the cells in the blood and bone marrow are blast cells immature blood cells in the accelerated phase these leukemia cells grow quickly
in futures studies and the history of technology accelerating change is a perceived increase in the rate of technological change throughout history which may suggest faster and more profound change in the future and it may or may not be accompanied by equally profound social and cultural change
acceleration in human development process is the phenomenon which has been registered in many populations around the world this applies equally to the growth of certain anthropometric parameters and the speed of reaching sexual maturity these facts illustrate the results of secular changes in body height and appearance of the first menstruation menarche increases in human stature are a main indicator of improvements in the average health of populations the newest data set for the average height of adult male birth cohorts from the mid nineteenth century to 1980 in 15 european countries was studied in the populations listed during a century average height increased by 11 cm representing a dramatic improvement of this phenomenon it is interesting that the apparent acceleration of body height occurred during the ĝ also in the mid nineteenth century young european women s menarche occurred at the average age of 16 5 years one hundred years later this age was reduced to under 12 years increase in adult height of birth cohorts cm decade
in the fields of physical security and information security access control ac is the selective restriction of access to a place or other resource the act of accessing may mean consuming entering or using permission to access a resource is called authorization locks and login credentials are two analogous mechanisms of access control
an access method is a function of a mainframe operating system that enables access to data on disk tape or other external devices they were introduced in 1963 in ibm os 360 operating system access methods provide an application programming interface api for programmers to transfer data to or from device and could be compared to device drivers in non mainframe operating systems
access to finance is the ability of individuals or enterprises to obtain financial services including credit deposit payment insurance and other risk management services those who involuntarily have no or only limited access to financial services are referred to as the unbanked or underbanked respectively accumulated evidence has shown that financial access promotes growth for enterprises through the provision of credit to both new and existing businesses it benefits the economy in general by accelerating economic growth intensifying competition as well as boosting demand for labor the incomes of those in the lower end of the income ladder will typically rise hence reducing income inequality and poverty the lack of financial access limits the range of services and credits for household and enterprises poor individuals and small enterprises need to rely on their personal wealth or internal resources to invest in their education and businesses which limits their full potential and leading to the cycle of persistent inequality and diminished growth access to finance varies greatly between countries and ranges from about 5 percent of the adult population in papua new guinea and tanzania to 100 percent in the netherlands for a comprehensive list of estimated measures of access to finance across countries see demirgüç kunt beck honohan 2008 pp 190 – 191
an accessory auricle is considered a developmental anomaly resulting from the persistence of a structure which variably recapitulates the normal external ear
accessory breasts also known as polymastia supernumerary breasts or mammae erraticae is the condition of having an additional breast extra breasts may appear with or without nipples or areolae it is a condition and a form of atavism which is most prevalent in male humans and often goes untreated as it is mostly harmless in recent years many affected women have had a plastic surgery operation to remove the additional breasts for purely aesthetic reasons a related condition in which extra nipples form is called supernumerary nipple or polythelia
the accessory nail of the fifth toe is a physical trait of the small toe where a minuscule sixth toenail is present in the outer corner of the nail situated on the smallest toe it is commonly perceived to be especially prevalent amongst han chinese however this is partially due to legend and is not entirely medically proven
injury to the spinal accessory nerve can cause an accessory nerve disorder or spinal accessory nerve palsy which results in diminished or absent function of the sternocleidomastoid muscle and upper portion of the trapezius muscle
accessory pancreas is a small cluster of pancreas cells detached from the pancreas and sometimes found in the wall of the stomach or intestines
an accessory spleen supernumerary spleen splenule or splenunculus is a small nodule of splenic tissue found apart from the main body of the spleen accessory spleens are found in approximately 10 percent of the population and are typically around 1 centimeter in diameter they may resemble a lymph node or a small spleen they form either by the result of developmental anomalies or trauma they are medically significant in that they may result in interpretation errors in diagnostic imaging or continued symptoms after therapeutic splenectomy
in painting accidentalism is the effect produced by accidental lights
in astrophysics accretion is the accumulation of particles into a massive object by gravitationally attracting more matter typically gaseous matter in an accretion disk most astronomical objects such as galaxies stars and planets are formed by accretion processes
a cryptographic accumulator is a one way membership function it answers a query as to whether a potential candidate is a member of a set without revealing the individual members of the set one trivial example is how large composite numbers accumulate their prime factors as it s currently impractical to factor a composite number but relatively easy to divide a specific prime into another number to see if it is one of the factors and or to factor it out new members may be added or subtracted to the set of factors simply by multiplying or factoring out the number respectively more practical accumulators use a quasi commutative hash function where the size number of bits of the accumulator does not grow with the number of members the concept was introduced by j benaloh and m de mare in 1993 the concept has received renewed interest recently due to the proposed zerocoin add on to bitcoin which employs cryptographic accumulators to eliminate trackable linkage in the bitcoin blockchain which would make bitcoin anonymous and untraceable increasing privacy of transactions
acephalgic migraine also called acephalalgic migraine migraine aura without headache amigrainous migraine isolated visual migraine and optical migraine is a neurological syndrome it is a relatively uncommon variant of migraine in which the patient may experience aura nausea photophobia hemiparesis and other migraine symptoms but does not experience headache it is generally classified as an event fulfilling the conditions of migraine with aura with no or minimal headache it is sometimes distinguished from visual only migraine aura without headache also called ocular migraine
aceruloplasminemia is a rare autosomal recessive disorder in which iron gradually accumulates in the retina basal ganglia and other organs iron accumulation in the brain results in neurological problems that generally appear in adulthood and worsen over time aceruloplasminemia has been seen worldwide but its overall prevalence is unknown studies in japan have estimated that approximately 1 in 2 million adults in this population are affected aceruloplasminemia belongs to the group of genetic disorders called neurodegeneration with brain iron accumulation nbia
fractures of the acetabulum occur when the head of the femur is driven into the pelvis this is caused either by a blow on the side or by a blow in the front of the knee usually in a dashboard injury when the femur also may be fractured acetabulum in latin means a cup that holds vinegar collins english dictionary it is a cavity situated on the outer surface of innominate bone innominate bone is confluence of 3 bones the ilium ischium and pubis acetabulum and ball of femur form the hip joint fractures of the acetabulum in young individuals usually occur due to high energy injury like vehicular accident or fall from the height while in old individuals who have osteoporotic fragile bones can occur due to trivial fall the energy is transferred from the femoral head to the acetabulum resulting in the fracture the type of the fracture depends on the position of the limb and the direction of the force causing variety of fractures the credit of classifying these fractures and giving guidelines for surgical management goes to french surgeons robertt judet jean judet and emile letournel who in their landmark paper in 1964 described the column concept of the innominate bone mechanism of injury classification and surgical management of these complex injuries according to them the acetabulum is situated between two columns of innominate bone namely anterior ilio pubic column and posterior ilio ischial column they classified these fractures into elementary simple two part and associated complex three or more part fractures
acetoacetic ester synthesis is a chemical reaction where ethyl acetoacetate is alkylated at the α carbon to both carbonyl groups and then converted into a ketone or more specifically an α substituted acetone this is very similar to malonic ester synthesis acetoacetic ester synthesis
achalasia eɪkəˈleɪʒə a chalasia no relaxation is a failure of smooth muscle fibers to relax which can cause a sphincter to remain closed and fail to open when needed without a modifier achalasia usually refers to achalasia of the esophagus which is also called esophageal achalasia achalasia cardiae cardiospasm and esophageal aperistalsis achalasia can happen at various points along the gastrointestinal tract achalasia of the rectum for instance in hirschsprung s disease esophageal achalasia is an esophageal motility disorder involving the smooth muscle layer of the esophagus and the lower esophageal sphincter les it is characterized by incomplete les relaxation increased les tone and lack of peristalsis of the esophagus inability of smooth muscle to move food down the esophagus in the absence of other explanations like cancer or fibrosis achalasia is characterized by difficulty in swallowing regurgitation and sometimes chest pain diagnosis is reached with esophageal manometry and barium swallow radiographic studies various treatments are available although none cures the condition certain medications or botox may be used in some cases but more permanent relief is brought by esophageal dilatation and surgical cleaving of the muscle heller myotomy the most common form is primary achalasia which has no known underlying cause it is due to the failure of distal esophageal inhibitory neurons however a small proportion occurs secondary to other conditions such as esophageal cancer or chagas disease an infectious disease common in south america achalasia affects about one person in 100 000 per year there is no gender predominance for the occurrence of disease
achard syndrome is a syndrome consisting of arachnodactyly receding lower jaw and joint laxity limited to the hands and feet hypermobility and subluxations of the joints increased lateral excursion of the patellas and other findings reflect the increased ligament laxity it is not clear if it is a distinct entity
achard – thiers syndrome combines the features of adrenogenital syndrome and cushing syndrome it is also known as diabetic bearded woman syndrome diabète des femmes à barbe the disease is named for emile achard and joseph thiers
acheiria əˈkɪəriə is the congenital absence of one or both hands
acheiropodia achp also known as horn kolb syndrome acheiropody and aleijadinhos brazilian type is an autosomal recessive disorder that results in hemimelia a lack of formation of the distal extremities this is a congenital defect which consists of bilateral amputations of the distal upper and lower extremities as well as aplasia of the hands and feet it was first discovered and is prevalent almost exclusively in brazil
an achilles heel is a weakness in spite of overall strength which can actually or potentially lead to downfall while the mythological origin refers to a physical vulnerability idiomatic references to other attributes or qualities that can lead to downfall are common
achilles tendinitis also achilles tenosynovitis or achilles tendinopathy is tendinitis of the achilles tendon generally caused by overuse of the affected limb and is more common among athletes training under less than ideal conditions it should not be confused with xanthoma of the tendon which is the accumulation of cholesterol in patients with familial hypercholesterolemia
achilles tendon rupture is when the achilles tendon breaks the achilles is the most commonly injured tendon rupture can occur while performing actions requiring explosive acceleration such as pushing off or jumping the male to female ratio for achilles tendon rupture varies between 7 1 and 4 1 across various studies
achlorhydria eɪklɔərˈhaɪdriə or hypochlorhydria refers to states where the production of hydrochloric acid in gastric secretions of the stomach and other digestive organs is absent or low respectively it is associated with various other medical problems
the acholia is the lack or absence of bile secretion acholia is an uncommon trouble of the biliary function in the liver bile flow dissipates
achondrogenesis is a number of disorders that are the most severe form of congenital chondrodysplasia malformation of bones and cartilage these conditions are characterized by a small body short limbs and other skeletal abnormalities as a result of their serious health problems infants with achondrogenesis are usually born prematurely are stillborn or die shortly after birth from respiratory failure some infants however have lived for a while with intensive medical support researchers have described at least three forms of achondrogenesis designated as achondrogenesis type 1 a achondrogenesis type 1 b and achondrogenesis type 2 these types are distinguished by their signs and symptoms inheritance pattern and genetic cause other types of achondrogenesis may exist but they have not been characterized or their cause is unknown achondrogenesis type 1 a is caused by a defect in the microtubules of the golgi apparatus in mice a nonsense mutation in the thyroid hormone receptor interactor 11 gene trip 11 which encodes the golgi microtubule associated protein 210 gmap 210 resulted in defects similar to the human disease when their dna was sequenced human patients with achondrogenesis type 1 a also had loss of function mutations in gmap 210 gmap 210 moves proteins from the endoplasmic reticulum to the golgi apparatus because of the defect gmap 210 is not able to move the proteins and they remain in the endoplasmic reticulum which swells up the loss of golgi apparatus function affects some cells such as those responsible for forming bone and cartilage more than others achondrogenesis type 1 b is caused by a similar mutation in slc 26 a 2 which encodes a sulfate transporter
achondrogenesis type 1 b is a severe autosomal recessive skeletal disorder invariable fatal in the perinatal period it is characterized by extremely short limbs a narrow chest and a prominent rounded abdomen the fingers and toes are short and the feet may be rotated inward affected infants frequently have a soft out pouching around the belly button an umbilical hernia or near the groin an inguinal hernia achondrogenesis type 1 b is a rare genetic disorder its incidence is unknown achondrogenesis type 1 b is the most severe condition in a spectrum of skeletal disorders caused by mutations in the slc 26 a 2 gene this gene provides instructions for making a protein that is essential for the normal development of cartilage and for its conversion to bone mutations in the slc 26 a 2 gene disrupt the structure of developing cartilage preventing bones from forming properly and resulting in the skeletal problems characteristic of achondrogenesis type 1 b achondrogenesis type 1 b is inherited in an autosomal recessive pattern which means two copies of the gene in each cell are altered most often the parents of an individual with an autosomal recessive disorder are carriers of one copy of the altered gene but do not show signs and symptoms of the disorder
achondroplasia is a common cause of dwarfism it occurs as a sporadic mutation in approximately 80 of cases associated with advanced paternal age or it may be inherited as an autosomal dominant genetic disorder people with achondroplasia have short stature with an average adult height of 131 centimeters 52 inches for males and 123 centimeters 48 inches for females achondroplastic adults are known to be as short as 62 8 cm 24 7 in if both parents of a child have achondroplasia and both parents pass on the mutant gene then it is very unlikely that the homozygous child will live past a few months of its life the prevalence is approximately 1 in 25 000
achromatopsia achm also known as total color blindness is a medical syndrome that exhibits symptoms relating to at least five conditions the term may refer to acquired conditions such as cerebral achromatopsia also known as color agnosia but it typically refers to an autosomal recessive congenital color vision condition the inability to perceive color and to achieve satisfactory visual acuity at high light levels typically exterior daylight the syndrome is also present in an incomplete form which is more properly defined as dyschromatopsia it is estimated to affect 1 in 40 000 live births worldwide there is some discussion as to whether achromats can see color or not as illustrated in the island of the colorblind by oliver sacks some achromats cannot see color only black white and shades of grey with five different genes currently known to cause similar symptoms it may be that some do see marginal levels of color differentiation due to different gene characteristics with such small sample sizes and low response rates it is difficult to accurately diagnose the typical achromatic conditions if the light level during testing is optimized for them they may achieve corrected visual acuity of 20 100 to 20 150 at lower light levels regardless of the absence of color one common trait is hemeralopia or blindness in full sun in patients with achromatopsia the cone system and fibres carrying color information remain intact this indicates that the mechanism used to construct colors is defective
acid erosion also known as dental erosion is a type of tooth wear it is defined as the irreversible loss of tooth structure due to chemical dissolution by acids not of bacterial origin dental erosion is the most common chronic disease of children ages 5 – 17 although it is only relatively recently that it has been recognised as a dental health problem there is generally widespread ignorance of the damaging effects of acid erosion this is particularly the case with erosion due to fruit juices because they tend to be seen as healthy erosion is found initially in the enamel and if unchecked may proceed to the underlying dentin the most common cause of erosion is by acidic foods and drinks in general foods and drinks with a ph below 5 0 – 5 7 have been known to trigger dental erosion effects numerous clinical and laboratory reports link erosion to excessive consumption of drinks those thought to pose a risk are soft drinks some alcohol and fruit drinks fruit juices such as orange juice which contain citric acid and carbonated drinks such as colas in which the carbonic acid is not the cause of erosion but citric and phosphoric acid additionally wine has been shown to erode teeth with the ph of wine as low as 3 0 – 3 8 other possible sources of erosive acids are from exposure to chlorinated swimming pool water and regurgitation of gastric acids
acidosis is an increased acidity in the blood and other body tissue i e an increased hydrogen ion concentration if not further qualified it usually refers to acidity of the blood plasma acidosis is said to occur when arterial ph falls below 7 35 except in the fetus see below while its counterpart alkalosis occurs at a ph over 7 45 arterial blood gas analysis and other tests are required to separate the main causes the term acidemia describes the state of low blood ph while acidosis is used to describe the processes leading to these states nevertheless the terms are sometimes used interchangeably the distinction may be relevant where a patient has factors causing both acidosis and alkalosis wherein the relative severity of both determines whether the result is a high or a low ph the rate of cellular metabolic activity affects and at the same time is affected by the ph of the body fluids in mammals the normal ph of arterial blood lies between 7 35 and 7 50 depending on the species e g healthy human arterial blood ph varies between 7 35 and 7 45 blood ph values compatible with life in mammals are limited to a ph range between 6 8 and 7 8 changes in the ph of arterial blood and therefore the extracellular fluid outside this range result in irreversible cell damage
acid – base imbalance is an abnormality of the human body s normal balance of acids and bases that causes the plasma ph to deviate out of the normal range 7 35 to 7 45 in the fetus the normal range differs based on which umbilical vessel is sampled umbilical vein ph is normally 7 25 to 7 45 umbilical artery ph is normally 7 18 to 7 38 it can exist in varying levels of severity some life threatening
an acid – base reaction is a chemical reaction that occurs between an acid and a base several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their application in solving related problems these are called acid – base theories for example brønsted – lowry acid – base theory their importance becomes apparent in analyzing acid – base reactions for gaseous or liquid species or when acid or base character may be somewhat less apparent the first of these concepts was provided by the french chemist antoine lavoisier around 1776
acinar adenocarcinoma is a histological subtype of gland forming cancer that is diagnosed when cuboidal and or columnar shaped malignant cells in the neoplastic tissue form acini and tubules it is a common form of cancer occurring in the lung and prostate gland
acinar cell carcinoma of the pancreas also acinar cell carcinoma is a rare malignant exocrine tumour of the pancreas it represents 5 of all exocrine tumours of the pancreas making it the second most common type of pancreatic cancer it is abbreviated acc it typically has a guarded prognosis
acinic cell carcinoma is a malignant tumor representing 2 of all salivary tumors 90 of the time found in the parotid gland 10 intraorally on buccal mucosa or palate the disease presents as a slow growing mass associated with pain or tenderness in 50 of the cases often appears pseudoencapsulated
ackerman syndrome is a familial syndrome of fused molar roots with a single canal taurodontism hypotrichosis full upper lip without a cupid ’ s bow thickened and wide philtrum and occasional juvenile glaucoma it was described by james l ackerman a leon ackerman and a bernard ackerman it can also refer to interstitial granulomatous dermatitis
acne aestivalis also known as mallorca acne is a special form of polymorphous light eruption it is a monomorphous eruption consisting of multiple uniform red papular lesions reported to occur after sun exposure
acne conglobata is a highly inflammatory disease presenting with comedones nodules abscesses and draining sinus tracts this condition generally begins between the ages of 18 and 30 it usually persists for a very long time and often until the patient is around 40 years old although it often occurs where there is already an active acne problem it can also happen to people whose acne has subsided although the cause of this type of acne is unknown it is associated with testosterone and thus appears mainly in men it can be caused by anabolic steroid abuse and sometimes appears in men after stopping testosterone therapy it can also happen to someone who has a tumour that is releasing large amounts of androgens or to people in remission from autoimmune diseases such as leukemia in certain persons the condition may be triggered by exposure to aromatic hydrocarbons or ingestion of halogens
the term acne cosmetica refers to acne caused by or aggravated by cosmetics the mechanism was presumably a chemically induced plugging of the pilosebaceous orifice this became a significant problem for dermatologists in the 1970 s and 1980 s but with the improved formulations produced by cosmetic chemists over the past thirty years a diagnosis of acne cosmetica has become relatively rare daily dermatological practice the terms non comedogenic and non acne i genic appeared on moisturizers and other cosmetic compounds as manufacturers introduced re formulations sometimes associated with claims that the products were oil free or water based although early work produced lists of comedogenic chemicals in various strengths and vehicles it became apparent that one could not predict the actual comedogenicity of a product from its contents rather the finished product itself needed use testing the production of a low grade folliculitis by some components of cosmetic products has led to misdiagnosis on occasion people may not attribute their reactions to their cosmetics at first but may notice worsening symptoms after using certain face makeup sunblock or lip products reactions occur more commonly if applied cosmetics are let to sit and are not stripped after use
acne fulminans also known as acute febrile ulcerative acne is a severe form of the skin disease acne which can occur after unsuccessful treatment for another form of acne acne conglobata the condition is thought to be an immunologically induced disease in which elevated level of testosterone causes a rise in sebum and population of propionibacterium acnes bacteria the increase in the amount of p acnes or related antigens may trigger the immunologic reaction in some individuals and lead to an occurrence of acne fulminans in addition to testosterone isotretinoin may also precipitate acne fulminans possibly related to highly increased levels of p acnes antigens in the patient s immune system acne fulminans is a rare disease over the past several years fewer cases of this disease have occurred possibly because of earlier and better treatment of acne approximately 100 patients with acne fulminans have been described
acne keloidalis nuchae also known as acne keloidalis dermatitis papillaris capillitii folliculitis keloidalis folliculitis keloidis nuchae and nuchal keloid acne is a destructive scarring folliculitis that occurs almost exclusively on the occipital scalp of people of african descent primarily men this is mainly because men often cut their hair very low as opposed to women allowing the hair to prick the occipital scalp and upset it acne keloidalis nuchae most commonly presents itself in individuals aged 13 to 25 the disease is closely related to pseudofolliculitis barbae and both occur frequently in black men in the military where it is so common that services often have widely known protocols for management
acne mechanica is an acneiform eruption that has been observed after repetitive physical trauma to the skin such as rubbing occurring from clothing belts and straps or sports equipment football helmets and shoulder pads
acne medicamentosa commonly referred to as drug induced acne is acne that is caused or aggravated by medication because acne is generally a disorder of the pilosebaceous units caused by hormones the medications that trigger acne medicamentosa most frequently are hormone analogues it is also often caused by corticosteroids in this case it is referred to as steroid acne although the masculinizing hormone testosterone is most often blamed and although men with acne secondary to bodybuilding hormones are seen from time to time the major hormonal medications that causes acne are the progestin analogues present in hormonal contraception other medications can produce acneiform eruptions usually pimply bumps and pustules that look like acne some conditions mimic acne medicamentosa the most common mimic is folliculitis produced by an overgrowth of the malassezia species often secondary to oral or systemic corticosteroids or secondary to broad spectrum antibiotics such as the tetracycline family used in acne this is often misinterpreted as tetracycline resistant acne
acne miliaris necrotica also known as acne varioliformis consists of follicular vesicopustules sometimes occurring as solitary lesions that are usually very itchy
acne vulgaris or simply acne is a long term skin disease that occurs when hair follicles become clogged with dead skin cells and oil from the skin acne is characterized by areas of blackheads whiteheads pimples and greasy skin and may result in scarring the resulting appearance can lead to anxiety reduced self esteem and in extreme cases depression or thoughts of suicide genetics is thought to be the cause in 80 of cases the role of diet and cigarette smoking is unclear and neither cleanliness nor sunlight appear to be involved acne primarily affects skin with a greater number of oil glands including the face upper part of the chest and back during puberty in both sexes acne is often brought on by an increase in androgens such as testosterone excessive growth of the bacteria propionibacterium acnes which is normally present on the skin is often involved many treatment options are available to improve the appearance of acne including lifestyle changes procedures and medications eating fewer simple carbohydrates like sugar may help topical azelaic acid benzoyl peroxide and salicylic acid are commonly used treatments antibiotics and retinoids are available in both topical and oral formulations to treat acne however resistance to antibiotics may develop a number of birth control pills may be useful for preventing acne in women oral isotretinoin is usually reserved for severe acne due to greater potential side effects early and aggressive treatment is advocated by some to lessen the overall long term impact to individuals in 2013 acne was estimated to affect 660 million people globally making it the 8 th most common disease worldwide acne occurs most commonly during adolescence affecting an estimated 80 – 90 of teenagers in the western world lower rates are reported in some rural societies people may also be affected before and after puberty though it becomes less common in adulthood than in adolescence nearly half of people in their twenties and thirties continue to have acne about 4 continue to have difficulties into their forties
acne with facial edema also known as solid facial edema occurs uncommonly and is associated with a peculiar inflammatory edema of the mid third of the face
acneiform eruption refers to a group of dermatoses including acne vulgaris rosacea folliculitis and perioral dermatitis restated acneiform eruptions are follicular eruptions characterized by papules and pustules resembling acne the term acneiform literally refers to an appearance similar to acne the terminology used in this field can be complex and occasionally contradictory some sources consider acne vulgaris part of the differential diagnosis for an acneiform eruption other sources classified acne vulgaris under acneiform eruption mesh explicitly excludes perioral dermatitis from the category of acneiform eruptions though it does group acneiform eruptions and perioral dermatitis together under facial dermatoses
acoustic dispersion is the phenomenon of a sound wave separating into its component frequencies as it passes through a material the phase velocity of the sound wave is viewed as a function of frequency hence separation of component frequencies is measured by the rate of change in phase velocities as the radiated waves pass through a given medium
acoustic emission ae is the phenomenon of radiation of acoustic elastic waves in solids that occurs when a material undergoes irreversible changes in its internal structure for example as a result of crack formation or plastic deformation due to aging temperature gradients or external mechanical forces in particular ae is occurring during the processes of mechanical loading of materials and structures accompanied by structural changes that generate local sources of elastic waves this results in small surface displacements of a material produced by elastic or stress waves generated when the accumulated elastic energy in a material or on its surface is released rapidly the waves generated by sources of ae are of practical interest in the field of structural health monitoring shm quality control system feedback process monitoring and others in shm applications ae is typically used to detect locate and characterise damage
acoustic paramagnetic resonance apr is a phenomenon of resonant absorption of sound by a system of magnetic particles placed in an external magnetic field it occurs when the energy of the sound wave quantum becomes equal to the splitting of the energy levels of the particles the splitting being induced by the magnetic field apr is a variation of electron paramagnetic resonance epr where the acoustic rather than electromagnetic waves are absorbed by the studied sample apr was theoretically predicted in 1952 independently by semen altshuler and alfred kastler and was experimentally observed by w g proctor and w h tanttila in 1955
acoustic phonetics is a subfield of phonetics which deals with acoustic aspects of speech sounds acoustic phonetics investigates properties like the mean squared amplitude of a waveform its duration its fundamental frequency or other properties of its frequency spectrum and the relationship of these properties to other branches of phonetics e g articulatory or auditory phonetics and to abstract linguistic concepts like phones phrases or utterances the study of acoustic phonetics was greatly enhanced in the late 19 th century by the invention of the edison phonograph the phonograph allowed the speech signal to be recorded and then later processed and analyzed by replaying the same speech signal from the phonograph several times filtering it each time with a different band pass filter a spectrogram of the speech utterance could be built up a series of papers by ludimar hermann published in pflügers archiv in the last two decades of the 19 th century investigated the spectral properties of vowels and consonants using the edison phonograph and it was in these papers that the term formant was first introduced hermann also played back vowel recordings made with the edison phonograph at different speeds to distinguish between willis and wheatstone s theories of vowel production further advances in acoustic phonetics were made possible by the development of the telephone industry incidentally alexander graham bell s father alexander melville bell was a phonetician during world war ii work at the bell telephone laboratories which invented the spectrograph greatly facilitated the systematic study of the spectral properties of periodic and aperiodic speech sounds vocal tract resonances and vowel formants voice quality prosody etc on a theoretical level speech acoustics can be modeled in a way analogous to electrical circuits lord rayleigh was among the first to recognize that the new electric theory could be used in acoustics but it was not until 1941 that the circuit model was effectively used in a book by chiba and kajiyama called the vowel its nature and structure this book by japanese authors working in japan was published in english at the height of world war ii in 1952 roman jakobson gunnar fant and morris halle wrote preliminaries to speech analysis a seminal work tying acoustic phonetics and phonological theory together this little book was followed in 1960 by fant acoustic theory of speech production which has remained the major theoretical foundation for speech acoustic research in both the academy and industry fant was himself very involved in the telephone industry other important framers of the field include kenneth n stevens osamu fujimura and peter ladefoged
acoustic radiation pressure is the apparent pressure difference between the average pressure at a surface moving with the displacement of the wave propagation the lagrangian pressure and the pressure that would have existed in the fluid of the same mean density when at rest numerous authors make a distinction between the phenomena of rayleigh radiation pressure and langevin radiation pressure
acoustic resonance is a phenomenon that consists of a given acoustic system amplifying a sound whose frequency matches one of its own natural frequencies of vibration its resonance frequencies the term acoustic resonance is sometimes used to narrow mechanical resonance to the frequency range of human hearing but since acoustics is defined in general terms concerning vibrational waves in matter acoustic resonance can occur at frequencies outside the range of human hearing an acoustically resonant object usually has more than one resonance frequency especially at harmonics of the strongest resonance it will easily vibrate at those frequencies and vibrate less strongly at other frequencies it will pick out its resonance frequency from a complex excitation such as an impulse or a wideband noise excitation in effect it is filtering out all frequencies other than its resonance acoustic resonance is an important consideration for instrument builders as most acoustic instruments use resonators such as the strings and body of a violin the length of tube in a flute and the shape of a drum membrane acoustic resonance is also important for hearing for example resonance of a stiff structural element called the basilar membrane within the cochlea of the inner ear allows hair cells on the membrane to detect sound for mammals the membrane has tapering resonances across its length so that high frequencies are concentrated on one end and low frequencies on the other like mechanical resonance acoustic resonance can result in catastrophic failure of the vibrator the classic example of this is breaking a wine glass with sound at the precise resonant frequency of the glass although this is difficult in practice
acoustic shock is the symptoms a person may experience after hearing an unexpected loud sound the loud sound called an acoustic incident can be caused by feedback oscillation fax tones or signalling tones telemarketers and call centre employees are thought to be most at risk
acousto electric effect is a nonlinear phenomenon of generation of electric current in a piezo electric semiconductor by a propagating acoustic wave the generated electric current is proportional to the intensity of the acoustic wave and to the value of its electron induced attenuation the effect was theoretically predicted in 1953 by parmenter its first experimental observation was reported in 1957 by weinreich and white
acquired c 1 esterase inhibitor deficiency also known as acquired angioedema presents with symptoms indistinguishable from hereditary angioedema but generally with onset after the fourth decade of life c 4 levels are low and c 3 levels are normal
acquired brain injury abi is brain damage caused by events after birth rather than as part of a genetic or congenital disorder such as fetal alcohol syndrome perinatal illness or perinatal hypoxia abi can result in cognitive physical emotional or behavioural impairments that lead to permanent or temporary changes in functioning these impairments result from either traumatic brain injury e g physical trauma due to accidents assaults neurosurgery head injury etc or nontraumatic injury derived from either an internal or external source e g stroke brain tumours infection poisoning hypoxia ischemia encephalopathy or substance abuse abi does not include damage to the brain resulting from neurodegenerative disorders while research has demonstrated that thinking and behavior may be altered in virtually all forms of abi brain injury is itself a very complex phenomenon having dramatically varied effects no two persons can expect the same outcome or resulting difficulties the brain controls every part of human life physical intellectual behavioral social and emotional when the brain is damaged some part of a person s life will be adversely affected consequences of abi often require a major life adjustment around the person s new circumstances and making that adjustment is a critical factor in recovery and rehabilitation while the outcome of a given injury depends largely upon the nature and severity of the injury itself appropriate treatment plays a vital role in determining the level of recovery
acquired cystic kidney disease associated renal cell carcinoma is rare subtype of renal cell carcinoma
an acquired disorder is a medical condition which develops post fetally in contrast with a congenital disorder which is present at birth a congenital disorder may be antecedent to an acquired disorder such as eisenmenger s syndrome the term acquired may also be used to describe permanent or temporary modifications or devices such as a shunt which have been placed or created by a medical professional during palliation or treatment of a medical condition
acquired generalized lipodystrophy also known as lawrence syndrome and lawrence – seip syndrome is a rare skin condition that appears during childhood or adolescence characterized by fat loss affecting large areas of the body particularly the face arms and legs
acquired hemolytic anemia can be divided into immune and non immune mediated forms of hemolytic anemia
acquired idiopathic generalized anhidrosis aiga is characterized by generalized absence of sweating without other autonomic and neurologic dysfunction aiga is classified into 3 subgroups idiopathic pure sudomotor failure ipsf sweat gland failure sgf and sudomotor neuropathy with each subgroup presenting a different pathogenesis
acquired non inflammatory myopathy anim is a neurological disorder primarily affecting skeletal muscle most commonly in the limbs of humans resulting in a weakness or dysfunction in the muscle a myopathy refers to a problem or abnormality with the myofibrils which compose muscle tissue in general non inflammatory myopathies are a grouping of muscular diseases not induced by an autoimmune mediated inflammatory pathway these muscular diseases usually arise from a pathology within the muscle tissue itself rather than the nerves innervating that tissue anim has a wide spectrum of causes which include drugs and toxins nutritional imbalances acquired metabolic dysfunctions such as an acquired defect in protein structure and infections acquired non inflammatory myopathy is a different diagnosis than inflammatory myopathy inflammatory myopathies are a direct result of some type of autoimmune mediated pathway whereas anim is not the result of a dysfunction of the immune system in addition the cause of inflammatory myopathy is relatively unknown whereas many causal agents for anim have been discovered which typically affect the structural integrity and function of the muscle fibers most myopathies are typically first diagnosed and classified as an idiopathic inflammatory myopathy however a diagnosis of anim occurs when the cause of the myopathy is found to not arise from an autoimmune mechanism
acquired progressive lymphangioma also known as benign lymphangioendothelioma is a group of lymphangiomas that occur anywhere in young individuals grow slowly and present as bruise like lesions or erythematous macules
acral lentiginous melanoma is a kind of lentiginous skin melanoma melanoma is a potentially serious skin cancer that arises from pigment cells melanocytes although acral lentiginous melanoma is rare in caucasians and people with lighter skin types it is the most common subtype in people with darker skins acral lentiginous melanoma is observed on the palms soles under the nails and in the oral mucosa it occurs on non hair bearing surfaces of the body which may or may not be exposed to sunlight it is also found on mucous membranes it is the most common form of melanoma diagnosed amongst asian and sub saharan african ethnic groups the average age at diagnosis is between sixty and seventy years
acral necrosis is a symptom common in bubonic plague the striking black discoloration of skin and tissue primarily on the extremities acral is commonly thought to have given rise to the name black death associated both with the disease and the pandemic which occurred in the 14 th century the term in fact came from the figural sense of black that is ghastly lugubrious or dreadful clotting and bleeding beneath the skin cause an area of hemorrhage the presence of red blood cells lying outside of capillaries into the skin and subcutaneous tissue in isolation this is called an ecchymosis or bruise and may be the result of injury or illness however acral necrosis occurs when blood supply is disrupted for prolonged periods blackening and damaging the affected area and surrounding tissue with appropriate medical treatment areas with acral necrosis may be successfully restored to function and lead a normal life untreated cases can lead to death
an acral nevus also known as a melanocytic nevus of acral skin and melanocytic nevus with intraepidermal ascent of cells maniacs is a cutaneous condition characterized by a skin lesion that is usually macular or only slightly elevated and may display uniform brown or dark brown color but often with linear striations
acral persistent papular mucinosis is a skin condition caused by fibroblasts producing abnormally large amounts of mucopolysaccharides characterized by bilaterally symmetrical flesh colored papules localized to the hands and wrists
acrania is a rare congenital disorder that occurs in the human fetus in which the flat bones in the cranial vault are either completely or partially absent the cerebral hemispheres develop completely but abnormally the condition is frequently though not always associated with anencephaly the fetus is said to suffer from acrania if it meets the following criteria the fetus should have a perfectly normal facial bone a normal cervical column but without the fetal skull and a volume of brain tissue equivalent to at least one third of the normal brain size
acroangiodermatitis of mali also known as mali acroangiodermatitis and pseudo kaposi s sarcoma is a rare cutaneous condition often characterized by purplish blue to brown papules and plaques on the medial and lateral malleolus of both legs acroangiodermatitis is a rare skin condition characterised by hyperplasia of pre existing vasculature due to venous hypertension from severe chronic venous stasis it is associated with amputees haemodialysis hd patients with arteriovenous av shunts and patients with paralysed legs hepatitis c chronic venous insufficiency or av malformations avm patients present with itchy painful confluent violaceous or brown black macules papules or plaques usually at the distal lower limbs there may be ulceration and bleeding the histologic features are capillary proliferation and perivascular inflammation involving eosinophils in the dermis with minimal epidermal changes management includes compression therapy wound care and surgical correction of avm dapsone combined with leg elevation and compression and erythromycin for hd patients with av fistulas have also been reported the lesions may persist for years with complications like ulceration bleeding and infection
acrocallosal syndrome also known as acls is a rare autosomal recessive syndrome characterized by corpus callosum agenesis polydactyly multiple dysmorphic features motor and mental retardation and other symptoms the syndrome was first described by albert schinzel in 1979 it is associated with gli 3
acrocephalosyndactylia or acrocephalosyndactyly is the common presentation of craniosynostosis and syndactyly
an acrochordon plural acrochorda also known as a skin tag or fibroepithelial polyp is a small benign tumor that forms primarily in areas where the skin forms creases such as the neck armpit and groin they may also occur on the face usually on the eyelids acrochorda are harmless are typically painless and usually do not grow or change over time though tags up to a half inch long have been seen they are typically the size of a grain of rice the surface of an acrochordon may be smooth or irregular in appearance and is often raised from the surface of the skin on a fleshy stalk called a peduncle microscopically an acrochordon consists of a fibro vascular core sometimes also with fat cells covered by an unremarkable epidermis however tags may become irritated by shaving clothing jewellery or eczema it is believed that skin tags occur from skin rubbing up against skin since they are so often found in skin creases and folds studies have shown existence of low risk hpv 6 and 11 in skin tags hinting at a possible role in its pathogenesis acrochorda have been reported to have a prevalence of 46 in the general population a causal genetic component is thought to exist they also are more common in women than in men rarely they can be associated with the birt – hogg – dubé syndrome acromegaly and polycystic ovary syndrome skin tags may serve as a marker for those people whose carbohydrate metabolism is impaired and for those who may be at risk for diabetes mellitus type 2 although such a link has not been shown elevated blood sugar and insulin increase the incidence of skin tags through an unknown mechanism
acrocyanosis is persistent blue or cyanotic discoloration of the extremities most commonly occurring in the hands although it also occurs in the feet and distal parts of face although described over 100 years ago and not uncommon in practice the nature of this phenomenon is still uncertain the very term acrocyanosis is often applied inappropriately in cases when blue discoloration of the hands feet or parts of the face is noted the principal primary form of acrocyanosis is that of a benign cosmetic condition sometimes caused by a relatively benign neurohormonal disorder regardless of its cause the benign form typically does not require medical treatment a medical emergency would ensue if the extremities experience prolonged periods of exposure to the cold particularly in children and patients with poor general health however frostbite differs from acrocyanosis because pain via thermal nociceptors often accompanies the former condition while the latter is very rarely associated with pain there are also a number of other conditions that affect hands feet and parts of the face with associated skin color changes that need to be differentiated from acrocyanosis raynaud ’ s phenomenon pernio acrorygosis erythromelalgia blue finger syndrome the diagnosis may be challenging in some cases especially when these syndromes co exist acrocyanosis may be a sign of a more serious medical problem such as connective tissue diseases and diseases associated with central cyanosis other causative conditions include infections toxicities antiphospholipid syndrome cryoglobulinemia neoplasms in these cases the observed cutaneous changes are known as secondary acrocyanosis they may have a less symmetric distribution and may be associated with pain and tissue loss
acrodermatitis ac · ro · der · ma · ti · tis is a childhood form of dermatitis selectively affecting the hands and feet and may be accompanied by mild symptoms of fever and malaise it may also be associated with hepatitis b and other viral infections it is a diffuse chronic skin disease usually confined to the limbs seen mainly in women in northern central and eastern europe and characterized initially by an erythematous oedematous pruritic phase followed by sclerosis and atrophy it is caused by infection with borrelia burgdorferi
acrodermatitis chronica atrophicans aca also known as herxheimer disease and primary diffuse atrophy is a skin rash indicative of the third or late stage of european lyme borreliosis aca is a dermatological condition that takes a chronically progressive course and finally leads to a widespread atrophy of the skin involvement of the peripheral nervous system is often observed specifically polyneuropathy this progressive skin process is due to the effect of continuing active infection with the spirochete borrelia afzelii which is the predominant pathophysiology b afzelii may not be the exclusive etiologic agent of aca borrelia garinii has also been detected
acrodermatitis enteropathica is an autosomal recessive metabolic disorder affecting the uptake of zinc characterized by periorificial around the natural orifices and acral in the limbs dermatitis alopecia loss of hair and diarrhea similar features may be present in acquired zinc deficiency this disease also is related to deficiency of zinc due to congenital causes other names for acrodermatitis enteropathica include brandt syndrome danbolt – closs syndrome congenital zinc deficiency
acrodynia is a condition of pain and dusky pink discoloration in the hands and feet most often seen in children chronically exposed to heavy metals especially mercury the word acrodynia is derived from the greek where ακρος means high as in in an extremity and οδυνη means pain as such it might be erroneously used to indicate that a patient has pain in the hands or feet however acrodynia is a disease rather than a symptom the condition is known by a large number of other names including pink disease hydrargyria mercurialism erythredema erythredema polyneuropathy bilderbeck s selter s swift s and swift feer disease
acrodysostosis also known as arkless graham syndrome or maroteaux malamut syndrome is a rare congenital malformation syndrome which involves shortening of the interphalangeal joints of the hands and feet intellectual disability in approximately 90 of affected children and peculiar facies other common abnormalities include short head as measured front to back small broad upturned nose with flat nasal bridge protruding jaw increased bone age intrauterine growth retardation juvenile arthritis and short stature further abnormalities of the skin genitals teeth and skeleton may occur most reported cases have been sporadic but it has been suggested that the condition might be genetically related i e in an autosomal dominant mode of transmission both males and females are affected the disorder has been associated with the older age of parents at the time of conception a prkar 1 a mutation has been identified in acrodysostosis with hormone resistance
acrogeria also known as gottron s syndrome is a cutaneous condition characterized by premature aging more especially in the form of unusually fragile thin skin on the hands and feet distal extremities the prefix acro stems from the greek akros which alludes to extremity tip while the suffix geria comes from the greek gerôn which means elder this is one of the classic congenital premature aging syndromes occurring early in life among which are pangeria werner s syndrome progeria hutchinson – gilford s syndrome and acrogeria gottron s syndrome and was characterized in 1940 onset is in early childhood it progresses over the next few years and then remains stable over time with morphology colour and site remaining constant a bruising tendency has been observed it is believed that gottron syndrome may affect more females than males approximately forty cases have been reported in the medical literature since the discovery of the disorder
acrokeratoelastoidosis of costa also known as keratoelastoidosis marginalis is a familial condition characterized by multiple keratotic papules on the dorsum of the hands and feet palms soles in which electron microscopy shows rarified abnormal elastic tissue it was characterized in 1953 treatments such as liquid nitrogen salicylic acid tretinoin and prednisone have been tried though with limited success
acrokeratosis verruciformis also known as acrokeratosis verruciformis of hopf is a rare autosomal dominant disorder appearing at birth or in early childhood characterized by skin lesions that are small verrucous flat papules resembling warts along with palmoplantar punctate keratoses and pits however sporadic forms whose less than 10 cases have been reported presents at a later age usually after the first decade and generally lack palmoplantar keratoses whether acrokeratosis verruciformis and darier disease are related or distinct entities has been controversial like darier s disease it is associated with defects in the atp 2 a 2 gene however the specific mutations found in the atp 2 a 2 gene in acrokeratosis verruciformis have never been found in darier s disease
acromegaly is a condition that results from excess growth hormone gh after the growth plates have closed the initial symptom is typically enlargement of the hands and feet there may also be enlargement of the forehead jaw and nose other symptoms may include joint pain thicker skin deepening of the voice headaches and problems with vision complications of the disease may include type 2 diabetes sleep apnea and high blood pressure acromegaly is typically due to the pituitary gland producing too much growth hormone in more than 95 of people the excess production is due to a benign tumor known as a pituitary adenoma the condition is not inherited from a person s parents rarely acromegally is due to tumors in other parts of the body diagnosis is by measuring growth hormone after a person has drunk glucose or measuring insulin like growth factor i in the blood after diagnosis medical imaging of the pituitary is carried out to look for an adenoma if excess growth hormone is produced during childhood the result is gigantism treatment option include surgery to remove the tumor medications and radiation therapy surgery is usually the preferred treatment and is most effective when the tumor is smaller in those in whom surgery is not effective medications of the somatostatin analogue or gh receptor antagonist type may be used the effects of radiation therapy are more gradual than that of surgery or medication without treatment those affected live on average 10 years less however with treatment life expectancy is typically normal acromegaly affects about 6 per 100 000 people it is most commonly diagnosed in middle age males and females are affected equally frequently the first medical description of the disorder occurred in 1772 by nicolas saucerotte the term is from greek ἄκρον akron meaning extremity and μέγα mega meaning large
acromesomelic dysplasia is a rare skeletal disorder that causes abnormal bone and cartilage development leading to shortening of the forearms lower legs hands feet fingers and toes five different genetic mutations have been implicated treatment is individualized but is generally aimed at palliating symptoms for example treatment of kyphosis and lumbar hyperlordosis
acroosteolysis is resorption of the distal bony phalanges acroosteolysis has two patterns of resorption in adults diffuse and bandlike the diffuse pattern of resorption has a widely diverse differential diagnosis which includes pyknodysostosis collagen vascular disease and vasculitis raynaud s neuropathy trauma epidermolysis bullosa psoriasis frostbite sarcoidosis hypertrophic osteoarthropathy acromegaly and advanced leprosy the bandlike pattern of resorption may be seen with polyvinyl chloride exposure and hadju cheney syndrome a mnemonic commonly used for acro osteolysis is pinchfo pyknodysostosis psoriasis injury thermal burn frostbite neuropathy diabetes collagen vascular disease scleroderma raynaud s hyperparathyroidism familial hadju cheney progeria occupational polyvinyl exposure acroosteolysis may be associated with minimal skin changes or with ischemic skin lesions that may result in digital necrosis
acropachy or thyroid acropachy refers to a dermopathy associated with graves disease it is characterized by soft tissue swelling of the hands and clubbing of the fingers radiographic imaging of affected extremities typically demonstrates periostitis most commonly the metacarpal bones the exact cause is unknown but it is thought to be caused by stimulating auto antibodies that are implicated in the pathophysiology of graves thyrotoxicosis there is no effective treatment for acropachy since it is closely associated with graves disease it is associated with other manifestations of graves disease such as graves ophthalmopathy and thyroid dermopathy hereditary acropachy also known as isolated congenital nail clubbing may be associated with hpgd
acropectoral syndrome is an autosomal dominant skeletal dysplasia syndrome affecting the hands feet sternum and lumbosacral spine a recently proposed candidate gene for preaxial polydactyly is lmbr 1 encoding a novel transmembrane receptor which may be an upstream regulator of shh the lmbr 1 gene is on human chromosome 7 q 36
acrophobia from the greek ἄκρον ákron meaning peak summit edge and φόβος phóbos fear is an extreme or irrational fear or phobia of heights especially when one is not particularly high up it belongs to a category of specific phobias called space and motion discomfort that share both similar etiology and options for treatment most people experience a degree of natural fear when exposed to heights known as the fear of falling on the other hand those who have little fear of such exposure are said to have a head for heights a head for heights is advantageous for those hiking or climbing in mountainous terrain and also in certain jobs e g steeplejacks or wind turbine mechanics acrophobia sufferers can experience a panic attack in high places and become too agitated to get themselves down safely approximately two percent of the general population suffers from acrophobia with twice as many women affected as men
acropustulosis refers to acrodermatitis with pustular involvement types include pustulosis palmaris et plantaris infantile acropustulosis
acrospiroma also known as hidradenoma is a cutaneous condition primarily occurring in adult women that is a form of benign adnexal neoplasm closely related to poroma
acro – dermato – ungual – lacrimal – tooth adult syndrome is a rare genetic disease adult syndrome is an autosomal dominant form of ectodermal dysplasia a group of disorders that affects the hair teeth nails sweat glands and extremities the syndrome arises from a mutation in the tp 63 gene this disease was previously thought to be a form of ectrodactyly – ectodermal dysplasia – cleft syndrome eec but was classified as a different disease in 1993 by propping and zerres
actinic cheilitis abbreviated to ac also termed actinic cheilosis actinic keratosis of lip solar cheilosis sailor s lip farmer s lip is cheilitis lip inflammation caused by long term sunlight exposure essentially it is a burn and a variant of actinic keratosis which occurs on the lip it is a premalignant condition as it can develop into squamous cell carcinoma a type of mouth cancer
actinic conjunctivitis is an inflammation of the eye contracted from prolonged exposure to actinic ultraviolet rays symptoms are redness and swelling of the eyes most often the condition is caused by prolonged exposure to klieg lights therapeutic lamps or acetylene torches other names for the condition include klieg conjunctivitis eyeburn arc flash welder s conjunctivitis flash keratoconjunctivitis actinic ray ophthalmia x ray ophthalmia and ultraviolet ray ophthalmia
actinic elastosis also known as solar elastosis is an accumulation of abnormal elastin elastic tissue in the dermis of the skin or in the conjunctiva of the eye which occurs as a result of the cumulative effects of prolonged and excessive sun exposure a process known as photoaging
actinic granuloma also known as o brien granuloma is a cutaneous condition characterized histologically by a dermal infiltrate of macrophages
actinic keratosis also called solar keratosis and senile keratosis abbreviated as ak is a pre cancerous patch of thick scaly or crusty skin these growths are more common in fair skinned people and those who are frequently in the sun they usually form when skin gets damaged by ultraviolet uv radiation from the sun or indoor tanning beds aks are considered potentially pre cancerous left untreated they may turn into a type of cancer called squamous cell carcinoma untreated lesions have up to a 20 risk of progression to squamous cell carcinoma so treatment by a dermatologist is recommended development of these growths occurs when skin is constantly exposed to the sun over time they usually appear as thick scaly or crusty areas that often feel dry or rough in fact aks are often felt before they are seen and the texture is often compared to sandpaper they may be dark light tan pink red a combination of all these or have the same color as the surrounding skin an actinic keratosis lesion commonly ranges between 2 and 6 millimeters in size but can grow to be a few centimeters in diameter they often appear on sun exposed areas of the skin such as the face ears neck scalp chest backs of hands forearms or lips because they are related to sun damage on the skin most people who have an ak have more than one often large areas of sun exposed skin are diagnosed with a continuum of multiple clinically visible aks of different sizes and severities typically accompanied by subclinical lesions that become apparent only in biopsies this concept of a skin area showing multiple aks is termed field cancerization diagnosis is suspected clinically on physical exam but can be confirmed by looking at cells from the lesion under a microscope different therapeutic options for ak are available photodynamic therapy pdt is recommended for the treatment of multiple ak lesions and field cancerization it involves the application of a photosensitizer to the skin followed by illumination with a strong light source topical creams may require daily application to affected skin areas over longer time periods cryotherapy is frequently used for single lesions but undesired hypopigmentation may occur at the treatment site by following up with a dermatologist aks can be treated before they turn into skin cancer if skin cancer does develop from an ak lesion it can be caught early with close monitoring at a time when treatment can be curative
actinobacillosis is a zoonotic disease caused by actinobacillus it is more commonly associated with animals than with humans one of the most commons form seen by veterinarians is the mouth actinobacillosis of cattle due to actinobacillus lignieresii the most prominent symptom is the swelling of the tongue that comes out of the mouth and is very hard at palpation wooden tongue actinobacillus suis is an important disease of pigs of all ages and can lead to severe morbidity and sudden death
actinomycosis is a rare infectious bacterial disease caused by actinomyces species about 70 of infections are due to either actinomyces israelii or a gerencseriae infection can also be caused by other actinomyces species as well as propionibacterium propionicus which presents similar symptoms the condition is likely to be polymicrobial aerobic anaerobic infection
activated pi 3 k delta syndrome apds also known as pasli disease is a primary immunodeficiency disease caused by activating gain of function mutations in the pik 3 cd gene which encodes the p 110 δ catalytic subunit of pi 3 kδ apds 2 pasli r 1 is caused by exon skipping mutations in pik 3 r 1 which encodes for the regulatory subunit p 85 α apds and apds 2 patients present with similar symptoms which include increased susceptibility to airway infections bronchiectasis and lymphoproliferation
activated protein c resistance apcr is a hemostatic disorder characterized by a poor anticoagulant response to activated protein c apc this results in an increased risk of venous thrombosis which can cause problems with circulation such as pulmonary embolism the disorder can be acquired or inherited the hereditary form having an autosomal dominant inheritance pattern
active networking is a communication pattern that allows packets flowing through a telecommunications network to dynamically modify the operation of the network active network architecture is composed of execution environments similar to a unix shell that can execute active packets a node operating system capable of supporting one or more execution environments it also consists of active hardware capable of routing or switching as well as executing code within active packets this differs from the traditional network architecture which seeks robustness and stability by attempting to remove complexity and the ability to change its fundamental operation from underlying network components network processors are one means of implementing active networking concepts active networks have also been implemented as overlay networks
in software engineering the active record pattern is an architectural pattern found in software that stores in memory object data in relational databases it was named by martin fowler in his 2003 book patterns of enterprise application architecture the interface of an object conforming to this pattern would include functions such as insert update and delete plus properties that correspond more or less directly to the columns in the underlying database table the active record pattern is an approach to accessing data in a database a database table or view is wrapped into a class thus an object instance is tied to a single row in the table after creation of an object a new row is added to the table upon save any object loaded gets its information from the database when an object is updated the corresponding row in the table is also updated the wrapper class implements accessor methods or properties for each column in the table or view this pattern is commonly used by object persistence tools and in object relational mapping orm typically foreign key relationships will be exposed as an object instance of the appropriate type via a property
the activity selection problem is a combinatorial optimization problem concerning the selection of non conflicting activities to perform within a given time frame given a set of activities each marked by a start time si and finish time fi the problem is to select the maximum number of activities that can be performed by a single person or machine assuming that a person can only work on a single activity at a time a classic application of this problem is in scheduling a room for multiple competing events each having its own time requirements start and end time and many more arise within the framework of operations research
the actual gold weight agw of a bullion coin or bar is the amount of fine pure or intrinsic gold content in troy ounces it is typically used to describe gold or silver coins for example if a certain coin weighed one troy ounce and the alloy contained 1 12 part of non gold metals the actual gold weight would be 11 12 troy ounces
actual malice in united states law is a condition required to establish libel against public officials or public figures and is defined as knowledge that the information was false or that it was published with reckless disregard of whether it was false or not reckless disregard does not encompass mere neglect in following professional standards of fact checking the publisher must entertain actual doubt as to the statement s truth this is the definition in only the united states and came from the landmark 1964 lawsuit new york times co v sullivan which ruled that public officials needed to prove actual malice in order to recover damages for libel this term was not newly invented for the sullivan case but was a term from existing libel law in many jurisdictions proof of actual malice was required in order for punitive damages to be awarded or for other increased penalties since proof of the writer s malicious intentions is hard to provide proof that the writer knowingly published a falsehood was generally accepted as proof of malice under the assumption that only a malicious person would knowingly publish a falsehood in the sullivan case the supreme court adopted this term and gave it constitutional significance at the same time defining it in terms of the proof which had previously been usual actual malice is different from common law malice which indicates spite or ill will it may also differ from actual malice as defined in state libel law as was confirmed in the case of carol burnett v national enquirer inc 1983 also see herbert v lando 1979 441 u s 153 1979 441 u s 153 fn 12 the existence of actual malice may be shown in many ways as a general rule any competent evidence either direct or circumstantial can be resorted to and all the relevant circumstances surrounding the transaction may be shown provided they are not too remote including threats prior or subsequent defamations subsequent statements of the defendant circumstances indicating the existence of rivalry ill will or hostility between the parties facts tending to show a reckless disregard of the plaintiff s rights
in medicine describing a disease as acute denotes that it is of short duration and as a corollary of that of recent onset the quantitation of how much time constitutes short and recent varies by disease and by context but the core denotation of acute is always qualitatively in contrast with chronic which denotes long lasting disease for example in acute leukemia and chronic leukemia in addition acute also often connotes two other meanings sudden onset and severity such as in acute myocardial infarction ami where suddenness and severity are both established aspects of the meaning it thus often connotes that the condition is fulminant as in the ami example but not always as in acute rhinitis which is usually synonymous with the common cold the one thing that acute mi and acute rhinitis have in common is that they are not chronic they can happen again as in recurrent pneumonia that is multiple acute pneumonia episodes but they are not the same case ongoing for months or years unlike chronic obstructive pulmonary disease which is a noncount sense of acute disease refers to the acute phase that is a short course of any disease entity for example in an article on ulcerative enteritis in poultry the author says in acute disease there may be increased mortality without any obvious signs referring to the acute form or phase of ulcerative enteritis
an acute abdomen refers to a sudden severe abdominal pain it is in many cases a medical emergency requiring urgent and specific diagnosis several causes need surgical treatment
acute basophilic leukemia is a rare form of acute myeloid leukemia where blasts are accompanied by abnormal basophils in all stages of differentiation it would most likely be classified as m 0 without electron microscopic confirmation of basophil lineage
acute beryllium poisoning is acute chemical pneumonia resulting from the toxic effect of beryllium in its elemental form or in various chemical compounds and is distinct from berylliosis also called chronic beryllium disease after occupational safety procedures were put into place following the realization that the metal caused berylliosis around 1950 acute beryllium poisoning became extremely rare
acute biphenotypic leukaemia is a form of leukaemia where the lineage is of both lymphoid and myeloid origin it is a subtype of leukemia of ambiguous lineage
acute bronchitis also known as a chest cold is short term inflammation of the bronchi large and medium sized airways of the lungs the most common symptom is a cough other symptoms include coughing up mucus wheezing shortness of breath fever and chest discomfort the infection may last from a few to ten days the cough may persist for several weeks afterwards with the total duration of symptoms usually around three weeks some have symptoms for up to six weeks in more than 90 of cases the cause is a viral infection these viruses may be spread through the air when people cough or by direct contact risk factors include exposure to tobacco smoke dust and other air pollution a small number of cases are due to high levels of air pollution or bacteria such as mycoplasma pneumoniae or bordetella pertussis diagnosis is typically based on a person s signs and symptom the color of the sputum does not indicate if the infection is viral or bacterial determining the underlying organism is typically not needed other causes of similar symptoms include asthma pneumonia bronchiolitis bronchiectasis and copd a chest x ray may be useful to detect pneumonia prevention is by not smoking and avoiding other lung irritants frequent hand washing may also be protective treatment of acute bronchitis typically involves rest paracetamol acetaminophen and nsaids to help with the fever cough medicine has little support for its use and is not recommended in children less than six years of age there is tentative evidence that salbutamol may be useful in those with wheezing however it may result in nervousness antibiotics should generally not be used an exception is when acute bronchitis is due to pertussis tentative evidence supports honey and pelargonium to help with symptoms acute bronchitis is one of the most common diseases about 5 of adults are affected and about 6 of children have at least one episode a year it occurs more often in the winter more than 10 million people in the united states visit a doctor each year for this condition with approximately 70 receiving antibiotics most of which are not needed there are efforts to decrease the use of antibiotics in acute bronchitis
acute cerebellar ataxia of childhood is a childhood condition characterized by an unsteady gait most likely secondary to an autoimmune of postinfectious cause drug induced or paraneoplastic most common virus causing acute cerebellar ataxia are chickenpox virus and epstein barr virus it is a diagnosis of exclusion
the acute chest syndrome is a vaso occlusive crisis of the pulmonary vasculature commonly seen in patients with sickle cell anemia this condition commonly manifests with pulmonary infiltrate on a chest x ray
acute coronary syndrome acs is a syndrome set of signs and symptoms due to decreased blood flow in the coronary arteries such that part of the heart muscle is unable to function properly or dies the most common symptom is chest pain often radiating to the left arm or angle of the jaw pressure like in character and associated with nausea and sweating acute coronary syndrome is usually caused by one of three problems st elevation myocardial infarction stemi 30 non st elevation myocardial infarction nstemi 25 or unstable angina 38 these types are named according to the appearance of the electrocardiogram ecg ekg as non st segment elevation myocardial infarction and st segment elevation myocardial infarction there can be some variation as to which forms of myocardial infarction mi are classified under acute coronary syndrome acs should be distinguished from stable angina which develops during exertion and resolves at rest in contrast with stable angina unstable angina occurs suddenly often at rest or with minimal exertion or at lesser degrees of exertion than the individual s previous angina crescendo angina new onset angina is also considered unstable angina since it suggests a new problem in a coronary artery though acs is usually associated with coronary thrombosis it can also be associated with cocaine use cardiac chest pain can also be precipitated by anemia bradycardias excessively slow heart rate or tachycardias excessively fast heart rate
acute cutaneous lupus erythematosus is a cutaneous condition characterized by a bilateral malar rash also known as a butterfly rash and lesions that tend to be transient and that follow sun exposure
acute decompensated heart failure adhf is a sudden worsening of the signs and symptoms of heart failure which typically includes difficulty breathing dyspnea leg or feet swelling and fatigue adhf is a common and potentially serious cause of acute respiratory distress the condition is caused by severe congestion of multiple organs by fluid that is inadequately circulated by the failing heart an attack of decompensation can be caused by underlying medical illness such as myocardial infarction infection or thyroid disease treatment consists of reducing the fluid level with diuretics and improving heart function with nitrates or levosimendan other treatments such as aquapheresis ultra filtration may also be required
acute disseminated encephalomyelitis adem or acute demyelinating encephalomyelitis is a rare autoimmune disease marked by a sudden widespread attack of inflammation in the brain and spinal cord as well as causing the brain and spinal cord to become inflamed adem also attacks the nerves of the central nervous system and damages their myelin insulation which as a result destroys the white matter it is often triggered after the patient has received a viral infection or perhaps exceedingly rarely specific non routine vaccinations adem s symptoms resemble the symptoms of multiple sclerosis ms so the disease itself is sorted into the classification of the multiple sclerosis borderline diseases however adem has several features that distinguish it from ms unlike ms adem occurs usually in children and is marked with rapid fever although adolescents and adults can get the disease too adem consists of a single flare up whereas ms is marked with several flare ups over a long period of time adem is also distinguished by a loss of consciousness coma and death which is very rare in ms except in severe cases the incidence rate is about 8 per 1 000 000 people per year although it occurs in all ages most reported cases are in children and adolescents with the average age around 5 to 8 years old the mortality rate may be as high as 5 however full recovery is seen in 50 to 75 of cases with increase in survival rates up to 70 to 90 with figures including minor residual disability as well the average time to recover from adem flare ups is one to six months adem produces multiple inflammatory lesions in the brain and spinal cord particularly in the white matter usually these are found in the subcortical and central white matter and cortical gray white junction of both cerebral hemispheres cerebellum brainstem and spinal cord but periventricular white matter and gray matter of the cortex thalami and basal ganglia may also be involved when the patient suffers more than one demyelinating episode of adem the disease is then called recurrent disseminated encephalomyelitis or multiphasic disseminated encephalomyelitis mdem also a fulminant course in adults has been described
acute eosinophilic leukemia ael is a rare subtype of acute myeloid leukemia with 50 to 80 percent of eosinophilic cells in the blood and marrow it can arise de novo or may develop in patients having the chronic form of a hypereosinophilic syndrome patients with acute eosinophilic leukemia have a propensity for developing bronchospasm and heart failure from endomyocardial fibrosis hepatomegaly and splenomegaly are more common than in other variants of aml
acute erythroid leukemia or di guglielmo syndrome is a rare form of acute myeloid leukemia less than 5 of aml cases where the myeloproliferation is of erythroblastic precursors it is defined as type m 6 under the fab classification
acute esophageal necrosis aen also known as gurvits syndrome black esophagus acute necrotizing esophagitis and esophageal infarction is a rare esophageal disorder aen defines itself with dark pigmentation of the esophagus found during an upper gastrointestinal endoscopy pigmentation is usually black friable mucosa the disorder is extremely rare as only 88 patients over a span of 40 years have received this diagnosis specific study of the disorder s mortality rate is mentioned at 31 8 but new research suggests mortality rates vary from 30 50 the exact triggering mechanism for this disorder is still unknown but is likely multifactorial
acute exacerbation of copd also known as acute exacerbations of chronic bronchitis aecb is a sudden worsening of copd symptoms shortness of breath quantity and color of phlegm that typically lasts for several days it may be triggered by an infection with bacteria or viruses or by environmental pollutants typically infections cause 75 or more of the exacerbations bacteria can roughly be found in 25 of cases viruses in another 25 and both viruses and bacteria in another 25 airway inflammation is increased during the exacerbation resulting in increased hyperinflation reduced expiratory air flow and decreased gas exchange as copd progresses exacerbations tend to become more frequent the average being about three episodes per year
acute fatty liver of pregnancy is a rare life threatening complication of pregnancy that occurs in the third trimester or the immediate period after delivery it is thought to be caused by a disordered metabolism of fatty acids by mitochondria in the mother caused by long chain 3 hydroxyacyl coenzyme a dehydrogenase deficiency the condition was previously thought to be universally fatal but aggressive treatment by stabilizing the mother with intravenous fluids and blood products in anticipation of early delivery has improved prognosis
acute flaccid myelitis formerly described as acute flaccid paralysis with anterior myelitis or polio like syndrome is an acute neurologic illness in children with focal limb weakness of unknown etiology enterovirus 68 which as a member of the enterovirus family is related to polio is a leading candidate for the cause of the condition due to the recent emergence of the condition the existing literature about it is tentative and should not be taken as established medical opinion there is no established treatment for the condition or the virus that may cause it
acute generalized exanthematous pustulosis agep also known as pustular drug eruption and toxic pustuloderma is a common cutaneous reaction pattern that in 90 of cases is related to medication administration characterized by a sudden eruption that appears on average five days after the medication is started it is mediated by t cells
acute haemmorrhagic conjunctivitis is the inflammation of the conjunctiva of sudden onset it presents as a reddening of the eye due to the infection of the conjunctiva the conjunctiva is a thin transparent tissue that covers the eye from the corneal limbus to the lid margin many conditions can lead to the inflammation of the conjunctiva they include allergies bacterial infection viral infection etc ghana is a country in sub saharan africa it is a former british colony endowed with rich mineral resources there are many eye conditions that affect its citizens one of them that continues to affect ghanaians every year is the seasonal conjunctivitis it is popularly referred to as apollo every year prior to the rainy season in the country various health warnings are given to remind citizens of the condition
an acute hemolytic transfusion reaction ahtr is a type of transfusion reaction that is associated with hemolysis it occurs very soon after the transfusion and within 24 hrs post transfusion it can occur quickly upon transfusing a few milliliters or up to 1 – 2 hours post transfusion it is also known as an immediate hemolytic transfusion reaction this is a medical emergency as it results from rapid destruction of the donor red blood cells by host antibodies igg igm it is usually related to abo blood group incompatibility the most severe of which often involves group a red cells being given to a patient with group o type blood properdin then binds to complement c 3 in the donor blood facilitating the reaction through the alternate pathway cascade the donor cells also become coated with igg and are subsequently removed by macrophages in the reticuloendothelial system res jaundice and disseminated intravascular coagulation dic may also occur the most common cause is clerical error i e the wrong unit of blood being given to the patient
acute hemorrhagic edema of infancy also known as acute hemorrhagic edema of childhood finkelstein s disease infantile postinfectious iris like purpura and edema medallion like purpura purpura en cocarde avec oedema and seidlmayer syndrome is a skin condition that affects children under the age of two with a recent history of upper respiratory illness a course of antibiotics or both the disease was first described in 1938 by finkelstein and later by seidlmayer as “ seidlmayer cockade purpura ”
acute infectious thyroiditis ait also known as suppurative thyroiditis microbial inflammatory thyroiditis pyrogenic thyroiditis and bacterial thyroiditis the thyroid is normally very resistant to infection due to a relatively high amount of iodine in the tissue as well as high vascularity and lymphatic drainage to the region it is difficult for pathogens to infect the thyroid tissue despite all this a persistent fistula from the piriform sinus may make the left lobe of the thyroid susceptible to infection and abscess formation ait is most often caused by a bacterial infection but can also be caused by a fungal or parasitic infection most commonly in an immunocompromised host
acute intermittent porphyria aip is a rare autosomal dominant metabolic disorder affecting the production of heme the oxygen binding prosthetic group of hemoglobin it is characterized by a deficiency of the enzyme porphobilinogen deaminase acute intermittent porphyria is the second most common form of porphyria porphyria cutanea tarda being the most common its incidence is estimated to be between 5 and 10 in 100 000 but this is likely underestimated because of positive cases not being induced and long periods of latency with an estimation that it is latent in 90 of cases
acute interstitial pneumonitis also known as acute interstitial pneumonia or hamman – rich syndrome is a rare severe lung disease that usually affects otherwise healthy individuals there is no known cause or cure acute interstitial pneumonitis is often categorized as both an interstitial lung disease and a form of acute respiratory distress syndrome ards but it is distinguished from the chronic forms of interstitial pneumonia such as idiopathic pulmonary fibrosis
acute kidney injury aki previously called acute renal failure arf is an abrupt loss of kidney function that develops within 7 days its causes are numerous generally it occurs because of damage to the kidney tissue caused by decreased kidney blood flow kidney ischemia from any cause e g low blood pressure exposure to substances harmful to the kidney an inflammatory process in the kidney or an obstruction of the urinary tract that impedes the flow of urine aki is diagnosed on the basis of characteristic laboratory findings such as elevated blood urea nitrogen and creatinine or inability of the kidneys to produce sufficient amounts of urine aki may lead to a number of complications including metabolic acidosis high potassium levels uremia changes in body fluid balance and effects on other organ systems including death people who have experienced aki may have an increased risk of chronic kidney disease in the future management includes treatment of the underlying cause and supportive care such as renal replacement therapy
acute limb ischaemia ali occurs when there is a sudden lack of blood flow to a limb acute limb ischaemia is caused by embolism or thrombosis or rarely by dissection or trauma thrombosis is usually caused by peripheral vascular disease atherosclerotic disease that leads to blood vessel blockage while an embolism is usually of cardiac origin in the united states ali is estimated to occur in 14 out of every 100 000 people per year with proper surgical care acute limb ischaemia is a highly treatable condition however delayed treatment beyond 6 to 12 hours can result in permanent disability amputation and or death the new latin term ischaemia as written is a british version of the word ischemia and stems from the greek terms ischein to hold and haima blood in this sense ischaemia refers to the inhibition of blood flow to through the limb
acute liver failure is the appearance of severe complications rapidly after the first signs of liver disease such as jaundice and indicates that the liver has sustained severe damage loss of function of 80 – 90 of liver cells the complications are hepatic encephalopathy and impaired protein synthesis as measured by the levels of serum albumin and the prothrombin time in the blood the 1993 classification defines hyperacute as within 1 week acute as 8 – 28 days and subacute as 4 – 12 weeks it reflects the fact that the pace of disease evolution strongly influences prognosis underlying etiology is the other significant determinant of outcome
acute lymphoblastic leukemia also known as acute lymphocytic leukemia or acute lymphoid leukemia all is an acute form of leukemia or cancer of the white blood cells characterized by the overproduction and accumulation of cancerous immature white blood cells known as lymphoblasts in persons with all lymphoblasts are overproduced in the bone marrow and continuously multiply causing damage and death by inhibiting the production of normal cells such as red and white blood cells and platelets in the bone marrow and by spreading infiltrating to other organs all is most common in childhood with a peak incidence at 2 – 5 years of age and another peak in old age the symptoms of all are indicative of a reduced production of functional blood cells because leukemia wastes the resources of the bone marrow that are normally used to produce new functioning blood cells these symptoms can include fever increased risk of infection especially bacterial infections like pneumonia due to neutropenia symptoms of such an infection include shortness of breath chest pain cough vomiting changes in bowel or bladder habits increased tendency to bleed due to thrombocytopenia and signs indicative of anemia including pallor tachycardia high heart rate fatigue and headache about 6 000 cases are reported in the united states every year internationally all is more common in caucasians than in africans it is more common in hispanics and in latin america cure is a realistic goal and is achieved in more than 80 of affected children although only 20 40 of adults are cured acute refers to the relatively short time course of the disease distinguishing it from chronic lymphocytic leukemia which has a potential time course of many years all was one of the first cancers for which an effective chemotherapeutic treatment was developed antifolates like aminopterin and methotrexate were developed in the late 1940 s by sidney farber and yellapragada subbarow at that time a doctor did not need a patient s or parent s consent to try an experimental treatment as the nuremberg code had not yet been signed desperate to save his patients farber initially tried folic acid supplementation as a treatment for all this had disastrous consequences and he likely accelerated the children s deaths
acute megakaryoblastic leukemia amkl is a form of leukemia where a majority of the blasts are megakaryoblastic it is classified under aml m 7 category of the french american british classification the latest who classification 2008 lyon classifies acute myeloid leukemia into distinct subtypes based on clinico pathological and molecular features acute megakaryoblastic leukemia is placed under the aml not otherwise specified subcategory diagnosis requires more than 20 blasts in the marrow peripheral blood with more than 50 demonstrating megakaryocytic derivation by morphology immunophenotypic or electron microscopic studies
acute monocytic leukemia amol or aml m 5 is considered a type of acute myeloid leukemia
acute motor axonal neuropathy aman is a variant of guillain – barré syndrome it is characterized by acute paralysis and loss of reflexes without sensory loss pathologically there is motor axonal degeneration with antibody mediated attacks of motor nerves and nodes of ranvier
acute muscle soreness is the pain felt in muscles during and immediately after strenuous physical exercise the pain appears within a minute of contracting the muscle and disappears within two or three minutes or up to several hours after relaxing it the following causes have been proposed for acute muscle soreness accumulation of chemical end products of exercise in muscle cells such as h tissue edema caused by the shifting of blood plasma into the muscle tissue during contraction muscle fatigue the muscle tires and cannot contract any more acute muscle soreness reflects one form of exercise induced muscle damage the other being delayed onset muscle soreness which appears between 24 and 72 hours after exercise
acute myeloblastic leukemia is a form of myeloid leukemia affecting myeloblasts more specifically it can refer to minimally differentiated acute myeloblastic leukemia m 0 in fab m 9872 3 acute myeloblastic leukemia without maturation m 1 in fab m 9873 3 acute myeloblastic leukemia with maturation m 2 in fab m 9874 3
m 2 is a subtype of aml acute myeloid leukemia it is also known as acute myeloblastic leukemia with maturation
acute myeloid dendritic cell leukemia is an exceedingly rare form of leukemia this form of leukemia represents only about 0 8 of all cases of acute myeloid leukemia dendritic cells function as antigen presenting cells they process antigen material and present it on the surface to other cells of the immune system dendritic cells develop from progenitors in the bone marrow and transform into two subtypes the myeloid dendritic cell and the plasmacytoid dendritic cell leukemic transformation can occur in any of these two cells but transformation of myeloid dendritic cell is less common and it leads to a form of leukemia known as acute myeloid dendritic cell leukemia
acute myeloid leukemia aml also known as acute myelogenous leukemia or acute nonlymphocytic leukemia anll is a cancer of the myeloid line of blood cells characterized by the rapid growth of abnormal white blood cells that accumulate in the bone marrow and interfere with the production of normal blood cells aml is the most common acute leukemia affecting adults and its incidence increases with age although aml is a relatively rare disease accounting for roughly 1 2 of cancer deaths in the united states its incidence is expected to increase as the population ages the symptoms of aml are caused by replacement of normal bone marrow with leukemic cells which causes a drop in red blood cells platelets and normal white blood cells these symptoms include fatigue shortness of breath easy bruising and bleeding and increased risk of infection several risk factors and chromosomal abnormalities have been identified but the specific cause is not clear as an acute leukemia aml progresses rapidly and is typically fatal within weeks or months if left untreated aml has several subtypes treatment and prognosis vary among subtypes aml is cured in 35 – 40 of people less than 60 years old and 5 – 15 more than 60 years old older people who are not able to withstand intensive chemotherapy have an average survival of 5 – 10 months aml is treated initially with chemotherapy aimed at inducing a remission people may go on to receive additional chemotherapy or a hematopoietic stem cell transplant recent research into the genetics of aml has resulted in the availability of tests that can predict which drug or drugs may work best for a particular person as well as how long that person is likely to survive the treatment and prognosis of aml differ from those of chronic myelogenous leukemia cml in part because the cellular differentiation is not the same aml involves higher percentages of dedifferentiated and undifferentiated cells including more blasts myeloblasts monoblasts and megakaryoblasts
acute myelomonocytic leukemia ammol is a form of acute myeloid leukemia that involves a proliferation of cfu gm myeloblasts and monoblasts it is classified under m 4 in the french american british classification fab it is classified under aml not otherwise classified in the who classification translocations have been observed progression from myelodysplastic syndrome has been reported acute myeloblastic leukemia aml is a group of malignant bone marrow neoplasms of myeloidprecursors of white blood cells acute myelomonocytic leukemia aml m 4 is a common type of pediatric aml however the condition is rare and represents approximately 3 of all leukemias during childhood and has an incidence of 1 1 – 1 7 per million per year the symptoms may be aspecific asthenia pallor fever dizziness and respiratory symptoms more specific symptoms are bruises and or excessive bleeding coagulation disorders dic neurological disorders and gingival hyperplasia diagnosticmethods include blood analysis bone marrow aspirate for cytochemical immunological and cytogeneticalanalysis and cerebrospinal fluid csf investigations a characteristic chromosomal abnormalityobserved in aml m 4 is inv 16 treatment includes intensive multidrug chemotherapy and in selected cases allogeneic bone marrow transplantation nevertheless outcome of aml remains poor with anoverall survival of 35 60 children with aml m 4 carrying the inv 16 abnormality have a better prognosis 61 5 year overall survival new therapeutics are required to increase the probability of cure in this serious disorder
acute necrotizing ulcerative gingivitis anug colloquially known as trench mouth is a common non contagious infection of the gums with sudden onset the main features are painful bleeding gums and ulceration of inter dental papillae the sections of gum between adjacent teeth this disease along with necrotizing ulcerative periodontitis np or nup is classified as a necrotizing periodontal disease one of the seven general types of periodontitis the often severe gingival pain that characterizes anug distinguishes it from the more common chronic periodontitis which is rarely painful anug is the acute presentation of necrotizing ulcerative gingivitis nug which is the usual course the disease takes if improperly treated or neglected nug may become chronic and or recurrent the causative organisms are mostly anaerobic bacteria particularly fusobacteria and spirocaete species predisposing factors include poor oral hygiene smoking malnutrition psychological stress and immunosuppression sub optimal functioning of the immune system when the attachments of the teeth to the bone are involved the term nup is used treatment of anug is by debridement although pain may prevent this and antibiotics usually metronidazole in the acute phase and improving oral hygiene to prevent recurrence although the condition has a rapid onset and is debilitating it usually resolves quickly and does no serious harm the synonym trench mouth arose during world war i as many soldiers developed the disease probably because of the poor conditions and extreme psychological stress
acute oak decline is a disease that infects oak trees in the uk it mainly affects mature oak trees of over 50 years old of both britain s native oak species the pedunculate oak quercus robur and the sessile oak quercus petraea the disease is characterised by the trees bleeding or oozing a dark fluid from small lesions or splits in their bark unlike chronic oak decline acute oak decline can lead to the death of trees within 4 to 5 years of symptoms appearing the number of trees affected is thought to number in the low thousands with a higher number of infected trees being found in the midlands it is thought to be caused by a bacterium it is currently not known which species is involved but scientists are actively trying to discover what is responsible at least three genera of bacteria are possibly responsible in some instances the disease is accompanied by insects attacking the trees too particularly the oak splendour beetle agrilus biguttatus these are not thought to be the cause of the disease but rather they are opportunistically taking advantage of already weakened trees such infestations further weaken and can hasten the death of trees
acute pancreatitis or acute pancreatic necrosis is a sudden inflammation of the pancreas it can have severe complications and high mortality despite treatment while mild cases are often successfully treated with conservative measures such as fasting and aggressive intravenous fluid rehydration severe cases may require admission to the intensive care unit or even surgery to deal with complications of the disease process
acute panmyelosis with myelofibrosis apmf it is a poorly defined disorder that arises as either a clonal disorder or following toxic exposure to the bone marrow
acute pericarditis is a type of pericarditis inflammation of the sac surrounding the heart the pericardium usually lasting less than 6 weeks it is by far the most common condition affecting the pericardium
acute posthemorrhagic anemia or acute blood loss anemia is a condition in which a person quickly loses a large volume of circulating hemoglobin acute blood loss is usually associated with an incident of trauma or a severe injury resulting in a large loss of blood it can also occur during or after a surgical procedure
acute proliferative glomerulonephritis is a disorder of the glomeruli glomerulonephritis or small blood vessels in the kidneys it is a common complication of bacterial infections typically skin infection by streptococcus bacteria types 12 4 and 1 impetigo but also after streptococcal pharyngitis for which it is also known as postinfectious or poststreptococcal glomerulonephritis it can be a risk factor for future albuminuria in adults the signs and symptoms of infection may still be present at the time when the kidney problems develop and the terms infection related glomerulonephritis or bacterial infection related glomerulonephritis are also used acute glomerulonephritis resulted in 19 000 deaths in 2013 down from 24 000 deaths in 1990
acute promyelocytic leukemia apml apl is the m 3 subtype of acute myelogenous leukemia aml a cancer of the white blood cells in apl there is an abnormal accumulation of immature granulocytes called promyelocytes the disease is characterized by a chromosomal translocation involving the retinoic acid receptor alpha rarα or rara gene and is distinguished from other forms of aml by its responsiveness to all trans retinoic acid atra also known as tretinoin therapy acute promyelocytic leukemia was first characterized in 1957 by french and norwegian physicians as a hyperacute fatal illness with a median survival time of less than a week today prognoses have drastically improved 10 year survival rates are estimated to be approximately 77 according to one study
acute prostatitis is a serious bacterial infection of the prostate gland this infection is a medical emergency it should be distinguished from other forms of prostatitis such as chronic bacterial prostatitis and chronic pelvic pain syndrome cpps
acute radiation syndrome ars also known as radiation poisoning radiation sickness or radiation toxicity is a collection of health effects that are present within 24 hours of exposure to high amounts of ionizing radiation the radiation causes cellular degradation due to damage to dna and other key molecular structures within the cells in various tissues this destruction particularly because it affects the ability of cells to divide normally in turn causes the symptoms the symptoms can begin within one or two hours and may last for several months the terms refer to acute medical problems rather than ones that develop after a prolonged period the onset and type of symptoms depends on the radiation exposure relatively smaller doses result in gastrointestinal effects such as nausea and vomiting and symptoms related to falling blood counts and predisposition to infection and bleeding relatively larger doses can result in neurological effects and rapid death treatment of acute radiation syndrome is generally supportive with blood transfusions and antibiotics with some more aggressive treatments such as bone marrow transfusions being required in extreme cases similar symptoms may appear months to years after exposure as chronic radiation syndrome when the dose rate is too low to cause the acute form radiation exposure can also increase the probability of developing some other diseases mainly different types of cancers these diseases are sometimes referred to as radiation sickness but they are never included in the term acute radiation syndrome
acute respiratory distress syndrome ards is a medical condition occurring in critically ill patients characterized by widespread inflammation in the lungs ards is not a particular disease rather it is a clinical phenotype which may be triggered by various pathologies such as trauma pneumonia and sepsis the hallmark of ards is diffuse injury to cells which form the alveolar barrier surfactant dysfunction activation of the innate immune response and abnormal coagulation in effect ards results in impaired gas exchange within the lungs at the level of the microscopic alveoli the syndrome is associated with a high mortality rate between 20 and 50 the mortality rate with ards varies widely based on severity the patient s age and the presence of other underlying medical conditions although the terminology of adult respiratory distress syndrome has at times been used to differentiate ards from infant respiratory distress syndrome in neonates international consensus is that acute respiratory distress syndrome is the best moniker because ards can affect those of all ages
acute retinal necrosis arn is a medical inflammatory condition of the eye the condition presents itself as a necrotizing retinitis the inflammation onset is due to certain herpes viruses varicella zoster virus vzv herpes simplex virus hsv 1 and hsv 2 and epstein barr virus ebv people with the condition usually display redness of the eye white or off white colored patches that are patches of retinal necrosis arn can progress into other conditions such as uveitis detachment of the retina and ultimately can lead to blindness the disease was first characterized in 1971 in japan akira urayama and his colleagues had six patients whose cases showed signs of acute necrotizing retinitis retinal arertitis choroiditis and late onset retinal detachment the combination of the conditions was given the name acute retinal necrosis the first reports of arn came about in 1971 it is unclear whether it was previously just reported as something else urayama and his colleagues reported the disease that they saw in six japanese patients since then the disease has been seen in patient s with aid s children and people who are immunocompromised in 1978 young and bird named the disease when presented in both eyes bilateral acute retinal necrosis otherwise known as barn
acute severe asthma also referred to in latin as status asthmaticus or asthmatic status is an acute exacerbation of asthma that does not respond to standard treatments of bronchodilators inhalers and steroids symptoms include chest tightness rapidly progressive dyspnea shortness of breath dry cough use of accessory respiratory muscles labored breathing and extreme wheezing it is a life threatening episode of airway obstruction and is considered a medical emergency complications include cardiac and or respiratory arrest it is characterized histologically by smooth muscle hypertrophy and basement membrane thickening
acute stress reaction also called acute stress disorder psychological shock mental shock or simply shock is a psychological condition arising in response to a terrifying or traumatic event or witnessing a traumatic event it should not be confused with the unrelated circulatory condition of shock or the concept of shock value acute stress reaction may develop into ptsd acute stress response was first described by walter cannon in the 1920 s as a theory that animals react to threats with a general discharge of the sympathetic nervous system the response was later recognized as the first stage of a general adaptation syndrome that regulates stress responses among vertebrates and other organisms
acute tubular necrosis atn is a medical condition involving the death of tubular epithelial cells that form the renal tubules of the kidneys atn presents with acute kidney injury aki and is one of the most common causes of aki common causes of atn include low blood pressure and use of nephrotoxic drugs the presence of muddy brown casts of epithelial cells found in the urine during urinalysis is pathognomonic for atn management relies on aggressive treatment of the factors that precipitated atn e g hydration and cessation of the offending drug because the tubular cells continually replace themselves the overall prognosis for atn is quite good if the cause is corrected and recovery is likely within 7 to 21 days
acytosiosis is a rare genetic disorder
the adam s apple or laryngeal prominence is a feature of the human neck and is the lump or protrusion that is formed by the angle of the thyroid cartilage surrounding the larynx
adam yves is a 1974 x rated film created for gay male audiences the film is notable for the unauthorized use of footage of greta garbo in what turned out to be the legendary actress s final appearance on film set in paris during springtime adam yves is about the french yves marcus giovanni and his pursuit of the american tourist adam michael hardwick the men have a brief affair but a long lasting relationship is prevented by yves insistence that they not share personal information while making the film director peter de rome reportedly stalked greta garbo around new york city where the retired star was living after much searching de rome located her and was able to shoot footage of garbo walking across first avenue the footage was inserted into adam yves and its presence was explained by having adam recalling how he once saw the elusive star the garbo footage was used without the star s knowledge or permission and she was not paid for her appearance
adamantinoma from the greek word adamantinos meaning very hard is a rare bone cancer making up less than 1 of all bone cancers it almost always occurs in the bones of the lower leg and involves both epithelial and osteofibrous tissue the condition was first described by fischer in 1913
the adams decarboxylation is a chemical reaction that involved the decarboxylation of coumarins which have carboxylic acid group in the third position the decarboxylation is achieved by aqueous solution of sodium bisulfite heat and a concentrated solution of sodium hydroxide file adams decarboxylation png
adams – nance syndrome is a medical condition consisting of persistent tachycardia paroxymal hypertension and seizures it is associated with hyperglycinuria dominantly inherited microphthalmia and cataracts it is thought to be caused by a disturbance in glycine metabolism
adams – oliver syndrome aos is a rare congenital disorder characterized by defects of the scalp and cranium cutis aplasia congenita transverse defects of the limbs and mottling of the skin
stokes – adams syndrome alternative eponyms include adams – stokes syndrome gerbezius morgagni adams – stokes syndrome and gerbec morgagni adams – stokes syndrome is a periodic fainting spell in which there is a periodic onset and offset of blockage of heart due to disorder of heart rhythm that may last for seconds hours days or even weeks before the conduction returns named after two irish physicians robert adams 1791 – 1875 and william stokes 1804 – 1877 the first description of the syndrome was published in 1717 by the carniolan physician of slovene descent marko gerbec which was 44 years after its publication quoted by giovanni battista morgagni it is characterised by decrease in cardiac output and loss of consciousness due to a transient arrhythmia for example bradycardia due to complete heart block
in biology an adaptation also called an adaptive trait is a trait with a current functional role in the life of an organism that is maintained and evolved by means of natural selection adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation adaptations enhance the fitness and survival of individuals organisms face a succession of environmental challenges as they grow and develop and are equipped with an adaptive plasticity as the phenotype of traits develop in response to the imposed conditions the developmental norm of reaction for any given trait is essential to the correction of adaptation as it affords a kind of biological insurance or resilience to varying environments
in ocular physiology adaptation is the ability of the eye to adjust to various levels of darkness and light
in software engineering the adapter pattern is a software design pattern that allows the interface of an existing class to be used as another interface it is often used to make existing classes work with others without modifying their source code
the add on factor is the difference between the usable area and the rentable area of an office building expressed as a factor of the rentable area this factor expresses the percentage of floor space for which a tenant pays rent but cannot derive benefit from due to columns corridors elevator shafts stairwells etc within the area leased also called a load factor or partial floor factor or when expressed as a percentage of the net usable area an add on factor
addictive redirects here for other uses see addiction disambiguation and addictive disambiguation addiction is a medical condition characterized by compulsive engagement in rewarding stimuli despite adverse consequences despite the involvement of a number of psychosocial factors a biological process – one which is induced by repeated exposure to an addictive stimulus – is the core pathology that drives the development and maintenance of an addiction the two properties that characterize all addictive stimuli are that they are reinforcing i e they increase the likelihood that a person will seek repeated exposure to them and intrinsically rewarding i e perceived as being positive or desirable addiction is a disorder of the brain s reward system which arises through transcriptional and epigenetic mechanisms and occurs over time from chronically high levels of exposure to an addictive stimulus e g morphine cocaine sexual intercourse gambling etc δfosb a gene transcription factor is a critical component and common factor in the development of virtually all forms of behavioral and drug addictions two decades of research into δfosb s role in addiction have demonstrated that addiction arises and the associated compulsive behavior intensifies or attenuates along with the genetic overexpression of δfosb in the d 1 type medium spiny neurons of the nucleus accumbens due to the causal relationship between δfosb expression and addictions it is used preclinically as an addiction biomarker δfosb expression in these neurons directly and positively regulates drug self administration and through positive reinforcement while decreasing sensitivity to aversion addiction exacts a high toll on individuals and society as a whole through the direct adverse effects of drugs associated healthcare costs long term complications e g lung cancer with smoking tobacco liver cirrhosis with drinking alcohol or meth mouth from intravenous methamphetamine the functional consequences of altered neural plasticity in the brain and the consequent loss of productivity classic hallmarks of addiction include impaired control over substances or behavior preoccupation with substance or behavior and continued use despite consequences habits and patterns associated with addiction are typically characterized by immediate gratification short term reward coupled with delayed deleterious effects long term costs examples of drug and behavioral addictions include alcoholism amphetamine addiction cocaine addiction nicotine addiction opiate addiction food addiction gambling addiction and sexual addiction the only behavioral addiction recognized by the dsm 5 is gambling addiction the term addiction is misused frequently to refer to other compulsive behaviors or disorders particularly dependence in news media
addiction vulnerability is the genetic physiological or psychological predisposition to engage in addictive behaviors a vulnerability to addiction may lead to an increased risk for a substance dependence addictions can arise in both a chemical and a behavioral manner a chemical addiction refers to a physical substance dependence where a behavioral addiction involves a psychological dependence genetics has been shown to account for 40 60 of a person ’ s likelihood to develop an addiction current research is now working toward establishing a comprehensive picture of the neurobiology of addiction vulnerability including all factors at work in propensity for addiction
addison ’ s disease also known as primary adrenal insufficiency is a long term endocrine disorder in which the adrenal glands do not produce enough steroid hormones symptoms generally come on slowly and may include abdominal pain weakness and weight loss darkening of the skin in certain areas may also occur under certain circumstances an adrenal crisis may occur with low blood pressure vomiting lower back pain and loss of consciousness an adrenal crisis can be triggered by stress such as from an injury surgery or infection addison s disease arises from problems with the adrenal gland such that not enough of the steroid hormone cortisol and possibly aldosterone are produced most often due to damage by the body s own immune system in the developed world and tuberculosis in the developing world other causes include certain medications sepsis and bleeding into both adrenal glands secondary adrenal insufficiency is caused by not enough adrenocorticotropic hormone acth produced by the pituitary gland or crh produced by the hypothalamus despite this distinction adrenal crises can happen in all forms of adrenal insufficiency addison s disease is generally diagnosed by blood tests urine tests and medical imaging treatment involves replacing the absent hormones this involves taking a corticosteroid such as hydrocortisone and fludrocortisone these medications are usually taken by mouth lifelong continuous steroid replacement therapy is required with regular follow up treatment and monitoring for other health problems a high salt diet may also be useful in some people if symptoms worsen an injection of corticosteroid is recommended and people should carry a dose with them often large amounts of intravenous fluids with the sugar dextrose are also required without treatment an adrenal crisis can result in death addison ’ s disease affects about 0 9 to 1 4 per 10 000 people in the developed world it occurs most frequently in middle aged females secondary adrenal insufficiency is more common long term outcomes with treatment are typically good it is named after thomas addison a graduate of the university of edinburgh medical school who first described the condition in 1855 the adjective addisonian is used to describe features of the condition as well as people with addison ’ s disease
in number theory an additive function is an arithmetic function f n of the positive integer n such that whenever a and b are coprime the function of the product is the sum of the functions f ab f a f b
addressability is the ability of a digital device to individually respond to a message sent to many similar devices examples include pagers mobile phones and set top boxes for pay tv computer networks are also addressable such as via the mac address on ethernet network cards and similar networking protocols like bluetooth this allows data to be sent in cases where it is impractical or impossible such as with wireless devices to control exactly where or to which devices the message is physically sent in the case of simple hardware devices like the pager the address is simply the electronic serial number and later imei meid in its firmware or physically manufactured into its circuitry in the case of gsm mobile phones it also includes the subscriber identity module which is also present as a smart card on satellite tv receivers or a different pcmcia cablecard for cable tv addressing and encryption are used together for conditional access to different tv channel bundles which a pay tv customer has or has not paid for addressing is also done in software at higher levels such as ip addresses which can be dynamically allocated even physically separate devices are now addressable such as to enforce revocation lists for digital restrictions or to use the former divx dvd video rentals although the latter only used its identity to phone home for billing purposes
adducted thumb syndrome recessive form also known as christian syndrome or craniostenosis arthrogryposis cleft palate is a rare disease affecting multiple systems which causes malformations of the palate thumbs and upper limbs the name christian syndrome derives from joe c christian the first person to describe the condition christian andrews conneally muller syndrome is another term named after the other authors p a andrews p m conneally and jans muller of the original publication it is an autosomal recessive connective tissue disorder characterized by congenital malformations contractures of the thumb and feet a typical facial appearance and normal cognitive development this is caused by mutation in the chst 14 carbohydrate sulfotransferase 14 gene
adducted thumbs syndrome is a condition inherited in an autosomal recessive fashion characterized by arthrogryposis craniosynostosis and myopathy in association with congenital generalized hypertrichosis
adenine phosphoribosyltransferase deficiency also called aprt deficiency or 2 8 dihydroxyadenine urolithiasis is an autosomal recessive metabolic disorder associated with a mutation in the enzyme adenine phosphoribosyltransferase
adenitis is a general term for an inflammation of a gland often it is used to refer to lymphadenitis which is the inflammation of a lymph node
adenocarcinoma ˌædᵻnoʊkɑːrsᵻˈnoʊmə plural adenocarcinomas or adenocarcinomata ˌædᵻnoʊkɑːrsᵻˈnoʊmᵻtə is a type of cancerous tumor that can occur in several parts of the body it is defined as neoplasia of epithelial tissue that has glandular origin glandular characteristics or both adenocarcinomas are part of the larger grouping of carcinomas but are also sometimes called by more precise terms omitting the word where these exist thus invasive ductal carcinoma the most common form of breast cancer is adenocarcinoma but does not use the term in its name — however esophageal adenocarcinoma does to distinguish it from the other common type of esophageal cancer esophageal squamous cell carcinoma several of the most common forms of cancer are adenocarcinomas and the various sorts of adenocarcinoma vary greatly in all their aspects so that few useful generalizations can be made about them in the most specific usage narrowest sense the glandular origin or traits are exocrine endocrine gland tumors such as a vipoma an insulinoma or a pheochromocytoma are typically not referred to as adenocarcinomas but rather are often called neuroendocrine tumors epithelial tissue sometimes includes but is not limited to the surface layer of skin glands and a variety of other tissue that lines the cavities and organs of the body epithelial tissue can be derived embryologically from any of the germ layers ectoderm endoderm or mesoderm to be classified as adenocarcinoma the cells do not necessarily need to be part of a gland as long as they have secretory properties adenocarcinoma is the malignant counterpart to adenoma which is the benign form of such tumors sometimes adenomas transform into adenocarcinomas but most do not well differentiated adenocarcinomas tend to resemble the glandular tissue that they are derived from while poorly differentiated adenocarcinomas may not by staining the cells from a biopsy a pathologist can determine whether the tumor is an adenocarcinoma or some other type of cancer adenocarcinomas can arise in many tissues of the body owing to the ubiquitous nature of glands within the body and more fundamentally to the potency of epithelial cells while each gland may not be secreting the same substance as long as there is an exocrine function to the cell it is considered glandular and its malignant form is therefore named adenocarcinoma
in situ pulmonary adenocarcinoma ais previously called bronchioloalveolar carcinoma bac is a term describing certain variants of lung cancer arising in the distal bronchioles or alveoli that initially exhibit a specific non invasive growth pattern bac is a type of non small cell lung cancer nsclc ais is defined as a small ≤ 3 cm solitary tumour with pure alveolar epithelial appearance lepidic growth lacking any invasion of the interstitium if completely resected the prognosis of surgically treated ais is 100
adenoid hypertrophy or enlarged adenoids is the unusual growth hypertrophy of the adenoid tonsil first described by the danish physician wilhelm meyer 1824 1895 in copenhagen in 1868 he described that a long term adenoid hypertrophy will cause an obstruction of the nasal airways these will lead to a dentofacial growth anomaly that was defined as adenoid facies see long face syndrome there is very little lymphoid tissue in the nasopharynx of young babies humans are born without substantial adenoids the mat of lymphoid tissue called adenoids starts to get sizable during the first year of life just how big the adenoids become is quite variable between individual children
adenoiditis is the inflammation of the adenoid tissue usually caused by an infection adenoiditis is treated using medication antibiotics and or steroids or surgical intervention adenoiditis may produce cold like symptoms however adenoiditis symptoms often persist for ten or more days and often include pus like discharge from nose the infection cause is usually viral however if the adenoiditis is caused by a bacterial infection antibiotics may be prescribed for treatment a steroidal nasal spray may also be prescribed in order to reduce nasal congestion severe or recurring adenoiditis may require surgical removal of the adenoids adenotonsillectomy
an adenoma from greek αδένας adeno gland ώμα oma tumor ˌædᵻˈnoʊmə plural adenomas or adenomata ˌædᵻˈnoʊmᵻtə is a benign tumor of epithelial tissue with glandular origin glandular characteristics or both adenomas can grow from many glandular organs including the adrenal glands pituitary gland thyroid prostate and others some adenomas grow from epithelial tissue in nonglandular areas but express glandular tissue structure as can happen in familial polyposis coli although adenomas are benign over time they may transform to become malignant at which point they are called adenocarcinomas most adenomas do not transform but even while benign they have the potential to cause serious health complications by compressing other structures mass effect and by producing large amounts of hormones in an unregulated non feedback dependent manner causing paraneoplastic syndromes some adenomas are too small to be seen macroscopically but can still cause clinical symptoms
adenoma sebaceum is a misnamed cutaneous disorder consisting of angiofibromas that begin in childhood generally present between 2 – 5 years of age and appear clinically as red papules on the face especially on the nasolabial folds cheek and chin mostly thought to be acne not responding to treatment adenoma sebaceum may at times be associated with tuberous sclerosis gradually the papules become more prominent with time and persist throughout life cosmetic removal by argon or pulse dye laser or scalpel is indicated
the adenomatoid odontogenic tumor is an odontogenic tumor arising from the enamel organ or dental lamina
adenomatoid tumor is a benign mesothelial tumor it generally presents in the genital tract in regions such as the testis and epididymis however it also has been found in the pancreas in the female it has been found in the body of the uterus and the fallopian tube
an adenomyoepithelioma of the breast also adenomyoepithelioma is a rare tumour in the breast composed of glandular elements adeno and myoepithelial cells it is usually benign however there are reports of malignant behaviour the histomorphologic appearance can mimic invasive ductal carcinoma the most common type of invasive breast cancer
adenomyoma is a tumor oma including components derived from glands adeno and muscle my it is a type of complex and mixed tumor
adenomyomatosis is a benign condition characterized by hyperplastic changes of unknown etiology involving the wall of the gallbladder
adenomyosis is a medical condition characterized by the presence of ectopic glandular tissue found in the muscular wall of the uterus myometria the term adenomyosis is derived from the greek terms adeno meaning gland myo meaning muscle and osis meaning condition previously named as endometriosis interna but adenomyosis differs from endometriosis and these two diseases represent two separate entities they are found together in many cases it usually refers to ectopic endometrial tissue the inner lining of the uterus within the myometrium the thick muscular layer of the uterus the term adenomyometritis specifically implies involvement of the uterus the condition is typically found in women between the ages of 35 and 50 but can also be present in younger women patients with adenomyosis often present with painful and or profuse menses dysmenorrhea menorrhagia respectively other possible symptoms are pain during sexual intercourse chronic pelvic pain and irritation of the urinary bladder in adenomyosis basal endometrium penetrates into hyperplastic myometrial fibers therefore unlike functional layer basal layer does not undergo typical cyclic changes with menstrual cycle adenomyosis may involve the uterus focally creating an adenomyoma with diffuse involvement the uterus becomes bulky and heavier
adenosine deaminase deficiency also called ada deficiency or ada scid is an autosomal recessive metabolic disorder that causes immunodeficiency it occurs in fewer than one in 100 000 live births worldwide it accounts for about 15 of all cases of severe combined immunodeficiency scid ada deficiency may be present in infancy childhood adolescence or adulthood age of onset and severity is related to some 29 known genotypes associated with the disorder
adenosine monophosphate deaminase deficiency type 1 also called myoadenylate deaminase deficiency madd is a recessive genetic metabolic disorder that affects approximately 1 – 2 of populations of european descent it appears to be considerably rarer in asian populations the genetic form is caused by a defect in the gene for amp deaminase though there is also an acquired form of amp deficiency
adenosquamous carcinoma is a type of cancer that contains two types of cells squamous cells thin flat cells that line certain organs and gland like cells
adenosquamous lung carcinoma adsqlc is a biphasic malignant tumor arising from lung tissue that is composed of at least 10 by volume each of squamous cell carcinoma sqcc and adenocarcinoma adc cells
adenovirus infections most commonly cause illness of the respiratory system however depending on the infecting serotype they may also cause various other illnesses and presentations
adenylosuccinate lyase deficiency also called adenylosuccinase deficiency is a rare autosomal recessive metabolic disorder characterized by the appearance of succinylaminoimidazolecarboxamide riboside saica riboside and succinyladenosine s ado in cerebrospinal fluid urine and to a lesser extent in plasma these two succinylpurines are the dephosphorylated derivatives of saica ribotide saicar and adenylosuccinate s amp the two substrates of adenylosuccinate lyase adsl which catalyzes an important reaction in the de novo pathway of purine biosynthesis adsl catalyzes two distinct reactions in the synthesis of purine nucleotides both of which involve the β elimination of fumarate to produce either aminoimidazole carboxamide ribotide aicar from saicar or adenosine monophosphate amp from s amp
adermatoglyphia is an extremely rare genetic disorder which causes a person to have no fingerprints there are only four known extended families worldwide which are affected by this condition recently the description of a case of a person from switzerland lacking fingerprints as an isolated finding was published the phenotype was mapped to chromosome 4 q 22 in the splice site of a 3 exon of the gene for smarcad 1 helicase a point mutation was detected it results in a shortened form of the skin specific protein the heterozygous mode of mutation suggests an autosomal dominant mode of inheritance other conditions can cause a lack of fingerprints but unlike them adermatoglyphia has no other side effects mutations in helicases are involved in other rare genetic diseases for instance werner syndrome
adhesions are fibrous bands that form between tissues and organs often as a result of injury during surgery they may be thought of as internal scar tissue that connects tissues not normally connected
adhesive capsulitis also known as frozen shoulder is a painful and disabling disorder of unclear cause in which the shoulder capsule the connective tissue surrounding the glenohumeral joint of the shoulder becomes inflamed and stiff greatly restricting motion and causing chronic pain pain is usually constant worse at night and with cold weather certain movements or bumps can provoke episodes of tremendous pain and cramping the condition is thought to be caused by injury or trauma to the area and may have an autoimmune component risk factors for frozen shoulder include tonic seizures diabetes mellitus stroke accidents lung disease connective tissue diseases thyroid disease and heart disease treatment may be painful and taxing and consists of physical therapy occupational therapy medication massage therapy hydrodilatation or surgery a physician may also perform manipulation under anesthesia which breaks up the adhesions and scar tissue in the joint to help restore some range of motion pain and inflammation can be controlled with analgesics and nsaids people who suffer from adhesive capsulitis usually experience severe pain and sleep deprivation for prolonged periods due to pain that gets worse when lying still and restricted movement positions the condition can lead to depression problems in the neck and back and severe weight loss due to long term lack of deep sleep people who suffer from adhesive capsulitis may have extreme difficulty concentrating working or performing daily life activities for extended periods of time the condition tends to be self limiting and usually resolves over time without surgery most people regain about 90 of shoulder motion over time
adie syndrome ˈeɪdi sometimes known as holmes – adie syndrome or adie s tonic pupil is a neurological disorder characterized by a tonically dilated pupil that reacts slowly to light but shows a more definite response to accommodation i e light near dissociation it is frequently seen in females with absent knee or ankle jerks and impaired sweating it is named after the british neurologist william john adie it is caused by damage to the postganglionic fibers of the parasympathetic innervation of the eye usually by a viral or bacterial infection which causes inflammation and affects the pupil of the eye and the autonomic nervous system
an adipose tissue neoplasm is a neoplasm derived from adipose tissue an example is lipoma
adiposis dolorosa also known as dercum s disease or anders disease is a rare condition characterized by generalized obesity and fatty tumors in the adipose tissue the tumors are normally painful and found in multiples on the extremities the understanding of the cause and mechanism of dercum disease remains unknown possible causes include nervous system dysfunction mechanical pressure on nerves adipose tissue dysfunction and trauma dercum s disease was first described at jefferson medical college by neurologist francis xavier dercum in 1892
adiposogenital dystrophy is a condition which may be caused by tertiary hypogonadism originating from decreased levels in gnrh low levels of gnrh has been associated with defects of the feeding centers of the hypothalamus leading to an increased consumption of food and thus caloric intake
adipsia also known as hypodipsia is a symptom of inappropriately decreased or absent feelings of thirst it involves an increased osmolality or concentration of solute in the urine which stimulates secretion of antidiuretic hormone adh from the hypothalamus to the kidneys this causes the person to retain water and ultimately become unable to feel thirst due to its rarity the disorder has not been the subject of many research studies adipsia may be seen in conditions such as diabetes insipidus and may result in hypernatremia it can occur as the result of abnormalities in the hypothalamus pituitary and corpus callosum as well as following pituitary hypothalamic surgery it is possible for hypothalamic dysfunction which may result in adipsia to be present without physical lesions in the hypothalamus although there are only four reported cases of this there are also some cases of patients experiencing adipsia due to a psychiatric disease in these rare psychogenic cases the patients have normal levels of urine osmolality as well as typical adh activity
an adjustment disorder ad — sometimes called exogenous or reactive or situational depression — occurs when an individual is unable to adjust to or cope with a particular stress or a major life event since people with this disorder normally have symptoms that depressed people do such as general loss of interest feelings of hopelessness and crying this disorder is sometimes known as situational depression unlike major depression the disorder is caused by an outside stressor and generally resolves once the individual is able to adapt to the situation one hypothesis about ad is that it may represent a sub threshold clinical syndrome the condition is different from anxiety disorder which lacks the presence of a stressor or post traumatic stress disorder and acute stress disorder which usually are associated with a more intense stressor common characteristics of ad include mild depressive symptoms anxiety symptoms and traumatic stress symptoms or a combination of the three there are nine types of ad listed in the dsm iii r according to the dsm iv tr there are six types of ad which are characterized by the following predominant symptoms depressed mood anxiety mixed depression and anxiety disturbance of conduct mixed disturbance of emotions and conduct and unspecified however the criteria for these symptoms are not specified in greater detail ad may be acute or chronic depending on whether it lasts more or less than six months according to the dsm iv tr if the ad lasts less than 6 months then it may be considered acute if it lasts more than six months it may be considered chronic moreover the symptoms cannot last longer than six months after the stressor s or its consequences have terminated diagnosis of ad is quite common there is an estimated incidence of 5 – 21 among psychiatric consultation services for adults adult women are diagnosed twice as often as are adult men among children and adolescents girls and boys are equally likely to receive this diagnosis ad was introduced into the psychiatric classification systems almost 30 years ago but similar syndromes were recognized for many years before that
the adler 2 5 litre in german adler 2 5 liter was a sensation when first presented by adler at the berlin motor show early in 1937 although this did not convert into correspondingly sensational sales production got under way in november 1937 seen as a successor for the six cylinder adler diplomat it was an executive sedan saloon featuring a strikingly streamlined body designed by karl jenschke 1899 – 1969 who till 1935 had been the director of engineering with steyr daimler puch jenschke s last creation during his time with steyr had been the steyr 50 which the adler 2 5 litre though larger closely resembled both on account of its uncompromisingly stream lined silhouette and because its launch coincided with germany ’ s first autobahn construction boom the car was popularly known as the autobahn adler the body for the four door fast back saloon came from ambi budd whose berlin based german business made the steel bodies for several of germany ’ s large automakers in the decade before the war the two and four door cabriolet bodies came from karmann of osnabrück
administrative resource is the ability of political candidates and parties to use their official positions or connections to government institutions to influence the outcome of elections the term is widely used in russia and other former ussr countries because the practice is widespread is well known and is openly discussed by public and media in these countries the administrative resource is one of the major factors in most elections similar practices are used to a varying degree all over the world including countries that are usually considered democratic the administrative resource is only one part that determines the election outcome two other major factors are the ideology candidate s agenda and the use of political technologies pr campaign organisation etc among many different ways the administrative resource can be applied are mobilisation of organisational and financial resources the authorities can easily pressure businessmen to fund preferred candidates and parties before russian parliamentary elections the money is often used to create authorities parties based not on a particular ideology but on affiliation with the government and easy access to money the laws can be selectively applied to assist friendly candidates by hindering their competition the authorities can use frequent tax inspections police searches and arrests to punish businessmen who fund the competing candidates the authorities can use the election laws to their advantage for example by creating a pretext for appealing the results later if the unfavourable candidate is winning another option is to stop from voting some groups of people who are likely to vote against the preferred candidate government controlled organisations such as the army prisons hospitals public schools etc can be mobilised for signature collection and other goals they can also pressure their employees and customers for voting for particular candidates and exercise control over votes by housing the polling stations redistribution of budget funds the authorities can bribe the electorate indirectly by repaying pension debts indexing salaries etc the federal government can control governors by measuring donations to their regions controlling the mass media the heads of states or regions can easily create news topics for media getting free publicity and circumventing the limits for tv advertisements imposed on all candidates this method was used with particular effectiveness in russian presidential election 2004 falsifying the election results additional ballots can be introduced under the names of those who didn t vote ballots for wrong candidate can be invalidated by damaging them ballots can be replaced the authorities can also control the staff of the election committees and prevent control by independent observers
an adnexal mass is a lump in tissue of the adnexa of uterus structures closely related structurally and functionally to the uterus such as the ovaries fallopian tubes or any of the surrounding connective tissue adnexal masses can be benign or cancerous and they can be categorized as simple or complex one of the most important factors used to determine the clinical suspicion of malignancy of an adnexal mass is the sonographic appearance of the mass indications that the mass is at a higher risk of being malignant include presence of loculations nodules papillary structures septations size greater than 10 cm
a adrenal adenoma is a benign tumor of the glandular type adenoma in the adrenal gland while some adrenal adenomas do not secrete hormones at all nonfunctional often diagnosed incidentally as incidentalomas some secrete cortisol causing cushing s syndrome aldosterone causing conn s syndrome or androgens causing hyperandrogenism
adrenal crisis also known as addisonian crisis and acute adrenal insufficiency is a medical emergency and potentially life threatening situation requiring immediate emergency treatment it is a constellation of symptoms that indicate severe adrenal insufficiency caused by insufficient levels of the hormone cortisol this may be the result of either previously undiagnosed or untreated addison s disease a disease process suddenly affecting adrenal function such as bleeding from the adrenal glands in waterhouse friderichsen syndrome suddenly stopping intake of glucocorticoids or an intercurrent problem e g infection trauma in fact any form of physical or mental stress in someone known to have addison s disease or congenital adrenal hyperplasia cah
adrenal gland disorders or diseases are conditions that interfere with the normal functioning of the adrenal glands adrenal disorders may cause hyperfunction or hypofunction and may be congenital or acquired the adrenal gland produces hormones that affects growth development and stress and also helps to regulate kidney function there are two parts of the adrenal glands the adrenal cortex and the adrenal medulla the adrenal cortex produces mineralocorticoids which regulate salt and water balance within the body glucocorticoids including cortisol which have a wide number of roles within the body and androgens hormones with testosterone like function the adrenal medulla produces epinephrine adrenaline and norepinephrine noradrenaline disorders of the adrenal gland may affect the production of one or more of these hormones
adrenal insufficiency is a condition in which the adrenal glands do not produce adequate amounts of steroid hormones primarily cortisol but may also include impaired production of aldosterone a mineralocorticoid which regulates sodium conservation potassium secretion and water retention craving for salt or salty foods due to the urinary losses of sodium is common addison s disease and congenital adrenal hyperplasia can manifest as adrenal insufficiency if not treated adrenal insufficiency may result in severe abdominal pains vomiting profound muscle weakness and fatigue depression extremely low blood pressure hypotension weight loss kidney failure changes in mood and personality and shock adrenal crisis an adrenal crisis often occurs if the body is subjected to stress such as an accident injury surgery or severe infection death may quickly follow adrenal insufficiency can also occur when the hypothalamus or the pituitary gland does not make adequate amounts of the hormones that assist in regulating adrenal function this is called secondary or tertiary adrenal insufficiency and is caused by lack of production of acth in the pituitary or lack of crh in the hypothalamus respectively
an adrenal tumor or adrenal mass is any benign or malignant neoplasms of the adrenal gland several of which are notable for their tendency to overproduce endocrine hormones adrenal cancer is the presence of malignant adrenal tumors and includes neuroblastoma adrenocortical carcinoma and some adrenal pheochromocytomas most adrenal pheochromocytomas and all adrenocortical adenomas are benign tumors which do not metastasize or invade nearby tissues but may cause significant health problems by unbalancing hormones
adrenalitis also called adrenitis is the inflammation of one or both adrenal glands which can lead to an insufficiency of epinephrine or norepinephrine types can include but are not limited to xanthogranulomatous adrenalitis autoimmune adrenalitis a major cause of addison s disease hemorrhagic adrenalitis
an adrenergic storm is a sudden and dramatic increase in serum levels of the catecholamines adrenalin and noradrenalin also known as epinephrine and norepinephrine respectively with a less significant increase in dopamine transmission it is a life threatening condition because of extreme tachycardia and hypertension and is especially dire for those with prior heart problems if treatment is prompt prognosis is good typically large amounts of diazepam or other benzodiazepines are administered alongside beta blockers beta blockers are contraindicated in some patients so other anti hypertensive medication such as clonidine may be used it is usually caused by overdose of stimulants especially cocaine but can also arise from improper eating habits while taking monoamine oxidase inhibitors a subarachnoid hemorrhage can also cause an adrenergic storm and catecholamine storm is part of the normal course of rabies infection and is responsible for the severe feelings of agitation terror and dysautonomia present in the pre coma stage of the disease
adrenergic urticaria is a skin condition characterized by an eruption consisting of small 1 5 mm red macules and papules with a pale halo appearing within 10 to 15 min after emotional upset
a adrenocortical adenoma or adrenal cortical adenoma is a benign tumor of the adrenal cortex it can present with cushing s syndrome or primary aldosteronism is a well circumscribed yellow tumour in the adrenal cortex which is usually 2 – 5 cm in diameter the color of the tumour as with adrenal cortex as a whole is due to the stored lipid mainly cholesterol from which the cortical hormones are synthesized these tumors are frequent incidental findings at post mortem examination and appear to have produced no significant metabolic disorder only a very small percentage lead to cushing s syndrome nevertheless these apparently non functioning adenomas are most often encountered in elder obese people there is some debate that they may really represent nodules in diffuse nodular cortical hyperplasia very occasionally a true adrenal cortical adenoma is associated with the clinical manifestations of conn s syndrome and can be shown to be excreting mineralocorticoids
adrenocortical carcinoma also adrenal cortical carcinoma acc and adrenal cortex cancer is an aggressive cancer originating in the cortex steroid hormone producing tissue of the adrenal gland adrenocortical carcinoma is a rare tumor with incidence of 1 – 2 per million population annually adrenocortical carcinoma has a bimodal distribution by age with cases clustering in children under 5 and in adults 30 – 40 years old adrenocortical carcinoma is remarkable for the many hormonal syndromes which can occur in patients with steroid hormone producing functional tumors including cushing s syndrome conn syndrome virilization and feminization adrenocortical carcinoma has often invaded nearby tissues or metastasized to distant organs at the time of diagnosis and the overall 5 year survival rate is only 20 – 35 the widely used angiotensin ii responsive steroid producing cell line h 295 r was originally isolated from a tumor diagnosed as adrenocortical carcinoma
adrenocortical hyperfunction is a condition where there is an overexpression of products of the adrenal cortex when cortisol is overproduced it is called cushing s syndrome when aldosterone is overproduced it is called hyperaldosteronism
adrenoleukodystrophy ˌlu koʊ ˈdis trə fiː also known as x linked adrenoleukodystrophy ald x ald siemerling – creutzfeldt disease or bronze schilder disease is a disease that is linked on the x chromosome it is a result of fatty acid digestive enzymes not breaking up the fats these fats build up in the brain they damage the myelin that surrounds nerves this can cause seizures and hyperactivity it can also cause problems with speaking listening and understanding verbal instructions in more detail it is a disorder of peroxisomal fatty acid beta oxidation which results in the accumulation of very long chain fatty acids in tissues throughout the body the most severely affected tissues are the myelin in the central nervous system the adrenal cortex and the leydig cells in the testes clinically ald is a heterogeneous disorder presenting with several distinct phenotypes and no clear pattern of genotype phenotype correlation as an x linked disorder ald presents most commonly in males however approximately 50 of heterozygote females show some symptoms later in life approximately two thirds of ald patients will present with the childhood cerebral form of the disease which is the most severe form it is characterized by normal development in early childhood followed by rapid degeneration to a vegetative state the other forms of ald vary in terms of onset and clinical severity ranging from adrenal insufficiency to progressive paraparesis in early adulthood this form of the disease is typically known as adrenomyeloneuropathy ald is caused by mutations in abcd 1 a gene located on the x chromosome that codes for ald a peroxisomal membrane transporter protein the exact mechanism of the pathogenesis of the various forms of ald is not known biochemically individuals with ald show very high levels of unbranched saturated very long chain fatty acids particularly cerotic acid 26 0 the level of cerotic acid in plasma does not correlate with clinical presentation treatment options for ald are limited dietary treatment is with lorenzo s oil for the childhood cerebral form stem cell transplant and gene therapy are options if the disease is detected early in the clinical course adrenal insufficiency in ald patients can be successfully treated ald is the most common peroxisomal inborn error of metabolism with an incidence estimated between 1 18 000 and 1 50 000 it does not have a significantly higher incidence in any specific ethnic groups
adson s sign is the loss of the radial pulse in the arm by rotating head to the ipsilateral side with extended neck following deep inspiration it is sometimes used as a sign of thoracic outlet syndrome tos it is named after alfred washington adson
adularescence is an optical phenomenon similar to labradorescence and aventurescence that is produced in gemstones such as moonstones
adult onset still s disease aosd is a rare systemic inflammatory disease characterized by the classic triad of persistent high spiking fevers joint pain and a distinctive salmon colored bumpy rash the disease is considered a diagnosis of exclusion levels of the iron binding protein ferritin may be elevated with this disorder aosd may present in a similar manner to other inflammatory diseases and to autoimmune diseases which must be ruled out before making the diagnosis prognosis is usually favorable but manifestations of the disease affecting the lungs heart or kidney may occasionally cause severe life threatening complications it is treated first with steroids such as prednisone drugs that block the action of interleukin 1 particularly il 1 β are effective treatments
adult onset immunodeficiency syndrome is a provisional name for a newly diagnosed immunodeficiency illness the name is proposed in the first public study to identify the syndrome it appears to be chronic and non contagious affecting mainly people of asian descent aged around 50 cases first started appearing in 2004 primarily in thailand and taiwan
adult t cell leukemia lymphoma atl or atll is a rare cancer of the immune system s own t cells human t cell leukemia lymphotropic virus type 1 htlv 1 is believed to be the cause of it in addition to several other diseases
adult attention deficit hyperactivity disorder also referred to as adult adhd or simply adhd in adults formerly aadd is the neurobiological condition of attention deficit hyperactivity disorder adhd in adults about one third to two thirds of children with symptoms from early childhood continue to demonstrate notable adhd symptoms throughout life three subtypes of adhd are identified in the dsm 5 as predominantly inattentive adhd pi predominantly hyperactive adhd ph combined type adhd c in later life the hyperactive impulsive subtype manifests less frequently the hyperactivity symptoms tend to turn more into inner restlessness starting in adolescence and carrying on in adulthood adult adhd is typically marked by inattentiveness difficulty getting work done procrastination and organizational problems specifically adults with adhd present with persistent difficulties in following directions remembering information concentrating organizing tasks completing work within specified time frames and appearing timely in appointments these difficulties affect several different areas of an adhd adult s life causing emotional social vocational marital legal financial and or academic problems as a result low self esteem is commonly developed however given the right guidance and coaching these traits of adhd could also lead to career success diagnosis of the condition follows after one or several assessment interviews by a clinician including examination of personal history observational evidence from family members or close friends academic reports often going back to school years etc as well as evaluation to diagnose additional possible conditions which often coexist with adhd called comorbidities or comorbid disorders the condition is highly heritable and while its exact causes are not fully known genetic or environmental factors are understood to play a part adhd is a childhood onset condition usually requiring symptoms to have been present before age 12 for a diagnosis children under treatment will migrate to adult health services if necessary as they transit into adulthood however diagnosis of adults involves full examination of their history successful treatment of adhd is usually based on a combination of medication cognitive behavioral therapy and coaching or skills training medium to high intensity physical exercise improved sleep and improved and targeted nutrition are also known to have a positive effect within school and work reasonable accommodations may be put in place to help the individual work more efficiently and productively
adult blaschkitis is a rare inflammatory skin condition presenting as pruritic papules and vesicles along multiple lines of blaschko
the advanced traffic management system atms field is a primary subfield within the intelligent transportation system its domain the atms view is a top down management perspective that integrates technology primarily to improve the flow of vehicle traffic and improve safety real time traffic data from cameras speed sensors etc flows into a transportation management center tmc where it is integrated and processed e g for incident detection and may result in actions taken e g traffic routing dms messages with the goal of improving traffic flow the national its architecture defines the following primary goals andmetrics for its increase transportation system efficiency enhance mobility improve safety reduce fuel consumption and environmental cost increase economic productivity and create an environment for an its market
the adms advanced disaster management simulator is an emergency and disaster management training simulation system designed to train incident commanders first responders and incident command teams in a real time interactive virtual reality vr environment adms was first introduced by environmental tectonics corporation etcc us in 1992 the development of adms was in response to the crash of british airtours flight 28 m at the manchester airport in 1985 in which 55 people died following the accident research indicated that first responder training should include realistic scenarios the first adms system was produced for the uk ministry of defence and delivered to royal air force ’ s raf manston facility since its inception adms has evolved into a modular expandable disaster simulation platform with systems in use worldwide
advanced sleep phase disorder aspd also known as the advanced sleep phase type aspt of circadian rhythm sleep disorder or advanced sleep phase syndrome asps is a condition in which patients feel very sleepy and go to bed early in the evening e g 6 00 – 8 00 p m and wake up very early in the morning e g around 3 00 a m
an adverse drug reaction adr is an injury caused by taking a medication adrs may occur following a single dose or prolonged administration of a drug or result from the combination of two or more drugs the meaning of this expression differs from the meaning of side effect as this last expression might also imply that the effects can be beneficial the study of adrs is the concern of the field known as pharmacovigilance an adverse drug event ade refers to any injury occurring at the time a drug is used whether or not it is identified as a cause of the injury an adr is a special type of ade in which a causative relationship can be shown
in medicine an adverse effect is an undesired harmful effect resulting from a medication or other intervention such as surgery an adverse effect may be termed a side effect when judged to be secondary to a main or therapeutic effect if it results from an unsuitable or incorrect dosage or procedure this is called a medical error and not a complication adverse effects are sometimes referred to as iatrogenic because they are generated by a physician treatment some adverse effects occur only when starting increasing or discontinuing a treatment using a drug or other medical intervention which is contraindicated may increase the risk of adverse effects adverse effects may cause complications of a disease or procedure and negatively affect its prognosis they may also lead to non compliance with a treatment regimen adverse effects of medical treatment resulted in 142 000 deaths in 2013 up from 94 000 deaths in 1990 globally the harmful outcome is usually indicated by some result such as morbidity mortality alteration in body weight levels of enzymes loss of function or as a pathological change detected at the microscopic macroscopic or physiological level it may also be indicated by symptoms reported by a patient adverse effects may cause a reversible or irreversible change including an increase or decrease in the susceptibility of the individual to other chemicals foods or procedures such as drug interactions
adverse reactions to biologic agents such as imatinib occur in more than 80 of patients and can be characterized by edema and pruritus without dermatitis
in aspect and functional programming advice describes a class of functions which modify other functions when the latter are run it is a certain function method or procedure that is to be applied at a given join point of a program the following is taken from a discussion at the mailing list aosd discuss pascal costanza contributed the following the term advice goes back to the term advising as introduced by warren teitelman in his phd thesis in 1966 here is a quote from chapter 3 of his thesis advising is the basic innovation in the model and in the pilot system advising consists of inserting new procedures at any or all of the entry or exit points to a particular procedure or class of procedures the procedures inserted are called advice procedures or simply advice since each piece of advice is itself a procedure it has its own entries and exits in particular this means that the execution of advice can cause the procedure that it modifies to be bypassed completely e g by specifying as an exit from the advice one of the exits from the original procedure or the advice may change essential variables and continue with the computation so that the original procedure is executed but with modified variables finally the advice may not alter the execution or affect the original procedure at all e g it may merely perform some additional computation such as printing a message or recording history since advice can be conditional the decision as to what is to be done can depend on the results of the computation up to that point the principal advantage of advising is that the user need not be concerned about the details of the actual changes in his program nor the internal representation of advice he can treat the procedure to be advised as a unit a single block and make changes to it without concern for the particulars of this block this may be contrasted with editing in which the programmer must be cognizant of the internal structure of the procedure advising found its way into bbn lisp and later into xerox parc s interlisp it also found its way to flavors the first object oriented extension to lisp developed at mit they were subsumed under the notion of method combination see for example aim 602 at since method combination and macros are closely related it s also interesting to note that the first macro system was described in 1963 three years before warren teitelman s phd thesis see aim 57 at
aerobic vaginitis av is a form of vaginitis first described by donders et al in 2002 it is characterized by a more or less severe disruption of the lactobacillary flora along with inflammation atrophy and the presence of a predominantly aerobic microflora composed of enteric commensals or pathogens it can be considered the aerobic counterpart of bacterial vaginosis the lack of acknowledgement of the difference between the two conditions might have led to inaccurate conclusions in several studies in the past the entity that has been described as desquamative inflammatory vaginitis probably corresponds to the more severe forms of aerobic vaginitis
aerophagia var aerophagy is a condition of excessive air swallowing which goes to the stomach aerophagia may also refer to an unusual condition where the primary symptom is excessive flatus belching is not present and the actual mechanism by which air enters the gut is obscure aerophagia in psychiatry is sometimes attributed to nervousness or anxiety
aerosinusitis also called barosinusitis sinus squeeze or sinus barotrauma is a painful inflammation and sometimes bleeding of the membrane of the paranasal sinus cavities normally the frontal sinus it is caused by a difference in air pressures inside and outside the cavities
an aerosol burn is an injury to the skin caused by the pressurized gas within an aerosol spray cooling quickly with the sudden drop in temperature sufficient to cause frostbite to the applied area medical studies have noted an increase of this practice known as frosting in pediatric and teenage patients adiabatic expansion causes the gas with a low boiling temperature to rapidly cool on exit from the aerosol applier according to controlled laboratory experiments the gas from a typical deodorant spray can reduce skin temperature by up to sixty degrees celsius the form of injury is freezing of the skin a type of frostbite it is highly advised for those who suffer from frostbite to seek medical attention in rare cases aerosol induced burns can be severe enough to necessitate skin grafting
affective sensation is a sensation accompanied with a strong compulsion to act on it causing reflex actions such as the scratch reflex gag reflex or the withdrawal reflex affective sensations are transmitted via the spinothalamic tract through the spinal cord sensory processing of the brain interacts with behavioral choices such as decisions to eat or stop eating in healthy individuals and in people with eating disorders taste serves to identify potential nutrients and toxins when subjects tasted a potentially nutritive stimulus the connectivity between the insula and a feeding network including the hypothalamus ventral pallidum and striatum was greater than when tasting a potentially harmful stimulus these results support the existence of an integrated supramodal flavor system in the anterior ventral insula that preferentially communicates with the circuits guiding feeding when the flavor is potentially nutritive affective sensory information is transmitted via the spinothalamic tract the sensation information is then accompanied by a compulsion to act for instance an itch is accompanied by a need to scratch and a painful stimulus makes us want to withdraw from the pain the location of the spinothalamic tract is important clinically due of the characteristic sensory deficits that follow certain spinal cord injuries for instance a unilateral spinal lesion will produce sensory loss of touch pressure vibration and proprioception below the lesion on the same side the pathways for pain and temperature however cross the midline to ascend on the opposite side of the cord therefore diminished sensation of pain below the lesion will be observed on the side opposite the mechanosensory loss and the lesion
the affective spectrum is a spectrum of affective disorders mood disorders it is a grouping of related psychiatric and medical disorders which may accompany bipolar unipolar and schizoaffective disorders at statistically higher rates than would normally be expected these disorders are identified by a common positive response to the same types of pharmacologic treatments they also aggregate strongly in families and may therefore share common heritable underlying physiologic anomalies affective spectrum disorders include attention deficit hyperactivity disorder bipolar disorder body dysmorphic disorder bulimia nervosa and other eating disorders cataplexy dysthymia general anxiety disorder hypersexuality irritable bowel syndrome impulse control disorders kleptomania migraine major depressive disorder obsessive compulsive disorder oppositional defiant disorder panic disorder posttraumatic stress disorder premenstrual dysphoric disorder social anxiety disorder fibromyalgia the following may also be part of the spectrum accompanying affective disorders chronic pain intermittent explosive disorder pathological gambling personality disorder pyromania substance abuse and addiction includes alcoholism trichotillomania also there are now studies linking heart disease many of the terms above overlap the american psychiatric association s definitions of these terms can be found in the diagnostic and statistical manual of mental disorders dsm
in catholic canon law affinity is an impediment to marriage of a couple due to the relationship which either party has as a result of a kinship relationship created by another marriage or as a result of out of marital intercourse the relationships that give rise to the impediment have varied over time marriages and sexual relations between people in an affinity relationship are regarded as incestuous today the relevant principle within the catholic church is that affinity does not beget affinity — i e there is no affinity between one spouse s relatives and the other spouse s relatives canon 109 of the code of canon law of the catholic church provides that affinity is an impediment to the marriage of a couple and is a relationship which arises from a valid marriage even if not consummated and exists between a man and the blood relatives of the woman and between the woman and the blood relatives of the man also affinity is reckoned in such a way that the blood relations of the man are related by affinity to the woman in the same line and the same degree and vice versa
african blackwood dermatitis is a condition characterized by an allergic contact dermatitis associated with a musical instrument made of a particular type of wood
african histoplasmosis is an infection caused by histoplasma duboisii disease has been most often reported in uganda nigeria zaire and senegal in human disease it manifests differently than histoplasmosis caused by histoplasma capsulatum most often involving the skin and bones and rarely involving the lungs
african iron overload also known as bantu siderosis or dietary iron overload is an iron overload disorder first observed among people of african descent in southern africa and central africa dietary iron overload is the consumption of large amount of home brewed beer with high amount of iron content in it preparing beer in iron pots or drums results in high iron content the iron content in home brewed beer is around 46 – 82 mg l compared to 0 5 mg l in commercial beer dietary overload was prevalent in both the rural and urban black african population with the introduction of commercial beer in urban areas the condition has decreased however the condition is still common in rural areas until recently studies have shown that genetics might play a role in this disorder combination of excess iron and functional changes in ferroportin seems to be the probable cause this disorder can be treated with phlebotomy therapy or iron chelation therapy
african tick bite fever is a bacterial infection transmitted by the amblyomma dermacentor or the rhipicephalus family of ticks it is caused by the rickettsia africae bacterium the incubation period of the disease is from 5 to 7 days and symptoms include fever headache and a skin rash the rash is characterized by scant lesions often macular and or vesicular
african trypanosomiasis also known as sleeping sickness is a parasitic disease of humans and other animals it is caused by protozoa of the species trypanosoma brucei there are two types that infect humans trypanosoma brucei gambiense t b g and trypanosoma brucei rhodesiense t b r t b g causes over 98 of reported cases both are usually transmitted by the bite of an infected tsetse fly and are most common in rural areas initially in the first stage of the disease there are fevers headaches itchiness and joint pains this begins one to three weeks after the bite weeks to months later the second stage begins with confusion poor coordination numbness and trouble sleeping diagnosis is via finding the parasite in a blood smear or in the fluid of a lymph node a lumbar puncture is often needed to tell the difference between first and second stage disease prevention of severe disease involves screening the population at risk with blood tests for t b g treatment is easier when the disease is detected early and before neurological symptoms occur treatment of the first stage is with the medications pentamidine or suramin treatment of the second stage involves eflornithine or a combination of nifurtimox and eflornithine for t b g while melarsoprol works for both stages it is typically only used for t b r due to serious side effects without treatment it typically results in death the disease occurs regularly in some regions of sub saharan africa with the population at risk being about 70 million in 36 countries as of 2010 it caused around 9 000 deaths per year down from 34 000 in 1990 an estimated 30 000 people are currently infected with 7000 new infections in 2012 more than 80 of these cases are in the democratic republic of the congo three major outbreaks have occurred in recent history one from 1896 to 1906 primarily in uganda and the congo basin and two in 1920 and 1970 in several african countries other animals such as cows may carry the disease and become infected in which case it is known as nagana
afterimage is a computer graphics effect used by video games the effect takes the bright parts of a rendered image of the scene and then fades in a motion blur style fashion as the scene progresses the result is that bright areas leave a fading trail when the camera is moving afterimage can be used to enhance blooming in some games the process is named light trail
afterload is the pressure in the wall of the left ventricle during ejection in other words it is the end load against which the heart contracts to eject blood afterload is readily broken into components one factor is the aortic pressure the left ventricular muscle must overcome to eject blood the greater the aortic pulmonary pressure the greater the after load on the left right ventricle respectively following laplace s law the tension upon the muscle fibers in the heart wall is the pressure within the ventricle multiplied by the volume within the ventricle divided by the wall thickness this ratio is the other factor in setting the afterload therefore when comparing a normal heart to a heart with a dilated left ventricle if the aortic pressure is the same in both hearts the dilated heart must create a greater tension to overcome the same aortic pressure to eject blood because it has a larger internal radius and volume thus the dilated heart has a greater total load tension on the myocytes i e has a higher afterload this is also true in the eccentric hypertrophy consequent to high intensity aerobic training conversely a concentrically hypertrophied left ventricle may have a lower afterload for a given aortic pressure when contractility becomes impaired and the ventricle dilates the afterload rises and limits output this may start a vicious circle in which cardiac output is reduced as oxygen requirements are increased afterload can also be described as the pressure that the chambers of the heart must generate in order to eject blood out of the heart and thus is a consequence of the aortic pressure for the left ventricle and pulmonic pressure or pulmonary artery pressure for the right ventricle the pressure in the ventricles must be greater than the systemic and pulmonary pressure to open the aortic and pulmonic valves respectively as afterload increases cardiac output decreases cardiac imaging is a somewhat limited modality in defining afterload because it depends on the interpretation of volumetric data
the age of the captain is a nonsensical mathematical word problem which cannot be answered even though there seems to be plenty of information supplied it was given for the first time by gustave flaubert in a letter to his sister caroline in 1841 puisque tu fais de la géométrie et de la trigonométrie je vais te donner un problème un navire est en mer il est parti de boston chargé de coton il jauge 200 tonneaux il fait voile vers le havre le grand mât est cassé il y a un mousse sur le gaillard d ’ avant les passagers sont au nombre de douze le vent souffle n e e l ’ horloge marque 3 heures un quart d ’ après midi on est au mois de mai … on demande l ’ âge du capitaine since you are now studying geometry and trigonometry i will give you a problem a ship sails the ocean it left boston with a cargo of wool it grosses 200 tons it is bound for le havre the mainmast is broken the cabin boy is on deck there are 12 passengers aboard the wind is blowing east north east the clock points to a quarter past three in the afternoon it is the month of may how old is the captain more recently a simpler version has been used to study how students react to word problems a captain owns 26 sheep and 10 goats how old is the captain
age segregation is separation of people based on their age and may be observed in many aspects of some societies examples of institutionalized age segregation include age segregation in schools and age segregated housing there are studies of informal age segregation among adolescents age segregation in schools age grading or graded education is the separation of students into years of education grades forms by approximately the same age in the united states graded education was introduced during 1848 to 1870 age grading in schools has significant impact on age segregation among adolescent peer groups age segregation in the u s was a product of industrialization western formal schooling child labor laws social services agencies and the rise of disciplines such as psychology and education a combination of these caused a shift from family working as a unit to separation of economic activities and childcare emerged some communities have different cultural practices and integrate children into mature activities of the family and community this is common among indigenous american communities
age segregation in schools age grading or graded education is the separation of students into years of education grades forms by approximately the same age in the united states graded education was introduced during 1848 to 1870 age grading in schools has significant impact on age segregation among adolescent peer groups
the ageing of europe also known as the greying of europe is a demographic phenomenon in europe characterised by a decrease in fertility a decrease in mortality rate and a higher life expectancy among european populations
agenesis of the corpus callosum acc is a rare birth defect congenital disorder in which there is a complete or partial absence of the corpus callosum it occurs when the corpus callosum the band of white matter connecting the two hemispheres in the brain fails to develop normally typically during pregnancy the fibers that would otherwise form the corpus callosum become longitudinally oriented within each hemisphere and form structures called probst bundles in addition to agenesis of the corpus callosum other callosal disorders include hypogenesis partial formation dysgenesis malformation of the corpus callosum and hypoplasia underdevelopment of the corpus callosum
ageostrophy is the real condition that works against geostrophic wind or geostrophic currents in the ocean and works against an exact balance between the coriolis force and the pressure gradient force while geostrophic currents or winds come from an equilibrium of a particular system ageostrophy is more often observed because of other forces such as friction or the centrifugal force from curved fluid flow
ageusia əˈɡjuːziə ə gew zee ə is the loss of taste functions of the tongue particularly the inability to detect sweetness sourness bitterness saltiness and umami meaning pleasant savory taste it is sometimes confused with anosmia – a loss of the sense of smell because the tongue can only indicate texture and differentiate between sweet sour bitter salty and umami most of what is perceived as the sense of taste is actually derived from smell true ageusia is relatively rare compared to hypogeusia – a partial loss of taste – and dysgeusia – a distortion or alteration of taste
agglomerates from the latin agglomerare meaning to form into a ball are coarse accumulations of large blocks of volcanic material that contain at least 75 bombs volcanic bombs differ from volcanic blocks in that their shape records fluidal surfaces they may for example have ropy cauliform scoriaceous or folded chilled margins and spindle spatter ribbon ragged or amoeboid shapes globular masses of lava may have been shot from the crater at a time when partly molten lava was exposed and was frequently shattered by sudden outbursts of steam these bombs were viscous at the moment of ejection and by rotation in the air acquired their shape they are commonly 1 to 2 feet 30 to 60 cm in diameter but specimens as large as 12 feet 3 7 m have been observed there is less variety in their composition at any one volcanic centre than in the case of the lithic blocks and their composition indicates the type of magma being erupted agglomerates are typically found near volcanic vents and within volcanic conduits where they may be associated with pyroclastic or intrusive volcanic breccias older pre 1970 publications particularly in scotland referred to any coarse grained volcaniclastic rock as agglomerate which led to debris flow deposits talus deposits and other types of breccia being mistaken for vents agglomerates are typically poorly sorted may contain a fine ash or tuff matrix and vary from matrix to clast support they may be monolithologic or heterolithic and may contain some blocks of various igneous rocks there are various differences between agglomerates and ordinary ash beds or tuffs agglomerates are coarser and less frequently well bedded agglomerates can be non welded or welded such as coarse basaltic spatter they typically form proximally during strombolian eruptions and are common at strongly peralkaline volcanoes some large agglomerate deposits are deposited from pyroclastic density currents during explosive caldera forming eruptions such as at santorini taal and campi flegrei they may be massive to crudely bedded and can attain great thicknesses crystalline masses of a different kind occur in some numbers in certain agglomerates they consist of volcanic minerals very much the same as those formed in the lava but exhibiting certain peculiarities which indicate that they have formed slowly under pressure at considerable depths they bear a resemblance to plutonic igneous rocks but are more correctly to be regarded as agglomerations of crystals formed within the liquid lava as it slowly rose towards the surface and at a subsequent period cast out by violent steam explosions the sanidinites of the eifel belong to this group at vesuvius ascension st vincent and many other volcanoes they form a considerable part of the coarser ash beds their commonest minerals are olivine anorthite hornblende augite biotite and leucite
in database management an aggregate function is a function where the values of multiple rows are grouped together as input on certain criteria to form a single value of more significant meaning or measurement such as a set a bag or a list common aggregate functions include average i e arithmetic mean count maximum nanmean mean ignoring nan values also known as nil or null median minimum mode sum aggregate functions are common in numerous programming languages spreadsheets and relational algebra
aggregation induced emission aie is an abnormal phenomenon for organic luminophores most organic compounds have a planar structure and higher photoemission efficiency in solution than in solid states however some organic luminophores have rotation groups which consume energy after they are excited in solution when these luminophores crystallize and the free rotation of groups is restricted in solid state the photoemission efficiency becomes higher than in solution
aggressive nk cell leukemia is a disease with an aggressive systemic proliferation of natural killer cells nk cells and a rapidly declining clinical course it is also called aggressive nk cell lymphoma
angiomyxoma is a myxoid tumor involving the blood vessels it can affect the vulva and other parts of the pelvis the characteristic feature of this tumor is its frequent local recurrence and it is currently regarded as a non metastasizing benign tumor
aggressive digital papillary adenocarcinoma also known as a digital papillary adenocarcinoma and papillary adenoma is a cutaneous condition characterized by an aggressive malignancy involving the digit between the nailbed and the distal interphalangeal joint spaces
aggressive fibromatosis is a rare condition marked by the presence of desmoid tumors desmoid tumors can arise in virtually any part of the body and are tumors that arise from cells called fibroblasts which are found throughout the body and provide structural support protection to the vital organs and play a critical role in wound healing these tumors tend to occur in women in their thirties but can occur in anyone at any age they can be either relatively slow growing or malignant however aggressive fibromatosis is locally aggressive when they are aggressive they can cause life threatening problems or even death when they compress vital organs such as intestines kidney lungs blood vessels nerves etc most cases are sporadic but some are associated with familial adenomatous polyposis fap approximately 10 of individuals with gardner s syndrome a type of fap with extracolonic features have desmoid tumors histologically they resemble very low grade fibrosarcomas but they are very locally aggressive and tend to recur even after complete resection there is a tendency for recurrence in the setting of prior surgery in one study two thirds of patients with desmoid tumors had a history of prior abdominal surgery risk factors for desmoid disease amongst fap patients include female sex a 3 apc mutation a positive family history and a history of previous abdominal surgery
aggressive lymphoma is a type of lymphoma that grows and spreads quickly and has severe symptoms it is seen frequently in patients who are hiv positive aids related lymphoma also called intermediate grade lymphoma and high grade lymphoma
agility or nimbleness is the ability to change the body s position efficiently and requires the integration of isolated movement skills using a combination of balance coordination speed reflexes strength and endurance agility is the ability to change the direction of the body in an efficient and effective manner and to achieve this requires a combination of balance – the ability to maintain equilibrium when stationary or moving i e not to fall over through the coordinated actions of our sensory functions eyes ears and the proprioceptive organs in our joints static balance – the ability to retain the centre of mass above the base of support in a stationary position dynamic balance – the ability to maintain balance with body movement speed the ability to move all or part of the body quickly strength the ability of a muscle or muscle group to overcome a resistance and lastly coordination – the ability to control the movement of the body in co operation with the body s sensory functions e g in catching a ball ball hand and eye coordination in sports agility is often defined in terms of an individual sport due to it being an integration of many components each used differently specific to all of sorts of different sports sheppard and young 2006 defined agility as a rapid whole body movement with change of velocity or direction in response to a stimulus agility is also an important attribute in many role playing games both computer games and pen and paper or tabletop games such as dungeons dragons agility may affect the character s ability to evade an enemy s attack or land their own move more quickly navigate uneven terrain or engage in stealthy activities such as lockpicking or pickpocketing
agility drills are used in the aim of improving sports agility which is the ability to change direction and accelerate while in motion the ability to change direction while in motion is very important in many sports but especially in team and dual sports for example a footballer running back must be able to quickly change direction when he sees an opponent preparing to tackle him and must be able to quickly change directions when dribbling the ball attempting to get back on defense or when trying to beat an opponent to the ball a tennis player must be able to quickly change directions when moving to a position where the ball is expected to go but instead finds the ball going in a different direction
an aging associated disease is a disease that is most often seen with increasing frequency with increasing senescence essentially aging associated diseases are complications arising from senescence age associated diseases are to be distinguished from the aging process itself because all adult animals age save for a few rare exceptions but not all adult animals experience all age associated diseases aging associated diseases do not refer to age specific diseases such as the childhood diseases chicken pox and measles aging associated disease is used here to mean diseases of the elderly nor should aging associated diseases be confused with accelerated aging diseases all of which are genetic disorders examples of aging associated diseases are atherosclerosis and cardiovascular disease cancer arthritis cataracts osteoporosis type 2 diabetes hypertension and alzheimer s disease the incidence of all of these diseases increases rapidly with aging increases exponentially with age in the case of cancer of the roughly 150 000 people who die each day across the globe about two thirds — 100 000 per day — die of age related causes in industrialized nations the proportion is higher reaching 90
aglossia aglossia congenita is a congential defect resulting in a partial development or complete absence of a tongue aglossiais commonly associated with craniofacial and limb defects adactylia syndrome and is thought to belong to a family of oromandibular limb hypogenesis syndrome or olhs it is believed to be caused by heat induced vascular disruption near the fourth week of embryonic development the first known case was reported in the early 18 th century by a member of the prominent de jussieu family in france and cases to this day remain rare
agnathia also termed hypognathous is absence of a portion or the entirety of one or both jaws it is a very rare condition
agnosia is the inability to process sensory information often there is a loss of ability to recognize objects persons sounds shapes or smells while the specific sense is not defective nor is there any significant memory loss it is usually associated with brain injury or neurological illness particularly after damage to the occipitotemporal border which is part of the ventral stream agnosia only affects a single modality such as vision or hearing
agonal respiration gasping respiration or agonal breathing is an abnormal pattern of breathing and brainstem reflex characterized by gasping labored breathing accompanied by strange vocalizations and myoclonus possible causes include cerebral ischemia extreme hypoxia or even anoxia agonal breathing is an extremely serious medical sign requiring immediate medical attention as the condition generally progresses to complete apnea and heralds death the duration of agonal respiration can be as brief as two breaths or last up to several hours the term is sometimes inaccurately used to refer to labored gasping breathing patterns accompanying organ failure e g liver failure and renal failure sirs septic shock and metabolic acidosis see kussmaul breathing or in general any labored breathing including biot s respirations and ataxic respirations correct usage would restrict the term to the last breaths before death agonal respirations are also commonly seen in cases of cardiogenic shock or cardiac arrest where agonal respirations may persist for several minutes after cessation of heartbeat the presence of agonal respirations in these cases indicates a more favorable prognosis than in cases of cardiac arrest without agonal respirations in an unresponsive pulseless patient in cardiac arrest agonal gasps are not effective breaths agonal respiration occurs in 40 of cardiac arrests experienced outside a hospital environment agonal respiration is not the same as and is unrelated to the phenomenon of death rattle
agoraphobia is an anxiety disorder characterized by symptoms of anxiety in situations where the person perceives the environment to be unsafe with no easy way to get away these situations can include open spaces public transit shopping malls or simply being outside the home being in these situations may result in a panic attack the symptoms occur nearly every time the situation is encountered and lasts for more than six months those affected will go to great lengths to avoid these situations in severe cases people may become unable to leave their homes the cause of agoraphobia is a combination of genetic and environmental factors the condition often runs in families and stressful events such as the death of a parent or being attacked may be a trigger in the dsm 5 agoraphobia is classified as a phobia along with specific phobias and social phobia other conditions that can produce similar symptoms include separation anxiety posttraumatic stress disorder and major depressive disorder those affected are at higher risk of depression and substance use disorder without treatment it is uncommon for agoraphobia to resolve treatment is typically with a type of counselling called cognitive behavioral therapy cbt cbt results in resolution for about half of people agoraphobia affects about 1 7 of adults women are affected about twice as often as men the condition often begins in early adulthood and becomes less common in old age it is rare in children the term agoraphobia is from greek ἀγορά meaning a public square and φοβία phobia meaning fear
agoraphobia without a history of panic disorder also called primary agoraphobia is an anxiety disorder where the sufferer does not meet the dsm 5 criteria for panic disorder agoraphobia typically develops as a result of having panic disorder in a small minority of cases however agoraphobia can develop by itself without being triggered by the onset of panic attacks agoraphobia can be caused by traumatic experiences such as bullying or abuse historically there has been debate over whether agoraphobia without panic genuinely existed or whether it was simply a manifestation of other disorders such as panic disorder general anxiety disorder avoidant personality disorder and social phobia one researcher said out of 41 agoraphobics seen at a clinic during a period of 1 year only 1 fit the diagnosis of agoraphobia without panic attacks and even this particular classification was questionable do not expect to see too many agoraphobics without panic in spite of this earlier skepticism current thinking is that agoraphobia without panic disorder is indeed a valid unique illness which has gone largely unnoticed since its sufferers are far less likely to seek clinical treatment
agranulocytosis also known as agranulosis or granulopenia is an acute condition involving a severe and dangerous leukopenia lowered white blood cell count most commonly of neutrophils causing a neutropenia in the circulating blood it is a severe lack of one major class of infection fighting white blood cells people with this condition are at very high risk of serious infections due to their suppressed immune system in agranulocytosis the concentration of granulocytes a major class of white blood cells that includes neutrophils basophils and eosinophils drops below 500 cells mm ³ of blood
agraphesthesia is a disorder of directional cutaneous kinesthesia or a disorientation of the skin s sensation across its space it is a difficulty recognizing a written number or letter traced on the skin after parietal damage
agraphia is an acquired neurological disorder causing a loss in the ability to communicate through writing either due to some form of motor dysfunction or an inability to spell the loss of writing ability may present with other language or neurological disorders disorders appearing commonly with agraphia are alexia aphasia dysarthria agnosia and apraxia the study of individuals with agraphia may provide more information about the pathways involved in writing both language related and motoric agraphia cannot be directly treated but individuals can learn techniques to help regain and rehabilitate some of their previous writing abilities these techniques differ depending on the type of agraphia agraphia can be broadly divided into central and peripheral categories central agraphias typically involve language areas of the brain causing difficulty spelling or with spontaneous communication and are often accompanied by other language disorders peripheral agraphias usually target motor and visuospatial skills in addition to language and tend to involve motoric areas of the brain causing difficulty in the movements associated with writing central agraphia may also be called aphasic agraphia as it involves areas of the brain whose major functions are connected to language and writing peripheral agraphia may also be called nonaphasic agraphia as it involves areas of the brain whose functions are not directly connected to language and writing typically motor areas the history of agraphia dates to the mid fourteenth century but it was not until the second half of the nineteenth century that it sparked significant clinical interest research in the twentieth century focused primary on aphasiology in patients with lesions from strokes
agrarian structure is the pattern of land area group distribution among landholders agricultural households
agreeableness is a personality trait manifesting itself in individual behavioral characteristics that are perceived as kind sympathetic cooperative warm and considerate in contemporary personality psychology agreeableness is one of the five major dimensions of personality structure reflecting individual differences in cooperation and social harmony people who score high on this dimension are empathetic and altruistic while a low agreeableness score relates to selfish behavior and a lack of empathy those who score very low on agreeableness show signs of dark triad behavior such as manipulation and competing with others rather than cooperating agreeableness is considered to be a superordinate trait meaning that it is a grouping of personality sub traits that cluster together statistically the lower level traits or facets grouped under agreeableness are trust straightforwardness altruism compliance modesty and tender mindedness
the aharonov – bohm effect sometimes called the ehrenberg – siday – aharonov – bohm effect is a quantum mechanical phenomenon in which an electrically charged particle is affected by an electromagnetic potential v a despite being confined to a region in which both the magnetic field b and electric field e are zero the underlying mechanism is the coupling of the electromagnetic potential with the complex phase of a charged particle s wave function and the aharonov – bohm effect is accordingly illustrated by interference experiments the most commonly described case sometimes called the aharonov – bohm solenoid effect takes place when the wave function of a charged particle passing around a long solenoid experiences a phase shift as a result of the enclosed magnetic field despite the magnetic field being negligible in the region through which the particle passes and the particle s wavefunction being negligible inside the solenoid this phase shift has been observed experimentally there are also magnetic aharonov – bohm effects on bound energies and scattering cross sections but these cases have not been experimentally tested an electric aharonov – bohm phenomenon was also predicted in which a charged particle is affected by regions with different electrical potentials but zero electric field but this has no experimental confirmation yet a separate molecular aharonov – bohm effect was proposed for nuclear motion in multiply connected regions but this has been argued to be a different kind of geometric phase as it is neither nonlocal nor topological depending only on local quantities along the nuclear path werner ehrenberg and raymond e siday first predicted the effect in 1949 and similar effects were later published by yakir aharonov and david bohm in 1959 after publication of the 1959 paper bohm was informed of ehrenberg and siday s work which was acknowledged and credited in bohm and aharonov s subsequent 1961 paper subsequently the effect was confirmed experimentally by several authors a general review can be found in peshkin and tonomura 1989
the ahmed mohamed clock incident occurred when a 14 year old boy ahmed mohamed was arrested on september 14 2015 at macarthur high school in irving texas for bringing an alleged hoax bomb to school the incident ignited allegations of racial profiling and islamophobia from media and commentators mohamed had reassembled the parts of a scrapped digital clock in a pencil case and brought it to school to show his teachers his english teacher thought the clock resembled a bomb and she confiscated it and reported him to the school s principal local law enforcement was called and mohamed was questioned by police for an hour and a half after being handcuffed and taken into custody and without being allowed to see his parents he was transported to a juvenile detention facility where he was fingerprinted and his mug shot photograph was taken he was then released to his parents the reason for his arrest was allegedly for purposely trying to cause a bomb scare the case was not pursued further by juvenile justice authorities however mohamed was suspended from school following the incident police determined mohamed had no malicious intent and he was not charged with any crime news of the incident became viral – initially on twitter – with allegations by some commentators that the actions of the school officials and police were due to their stereotyping of mohamed based on his sudanese ancestry and muslim faith after u s president barack obama politicians activists technology company executives and media personalities commented about the incident mohamed was invited to participate in a number of high profile events related to encouraging youth interest in science and technology apart from praise for his ingenuity there was also criticism and accusations that the incident was manufactured and a purposeful hoax on november 23 2015 ahmed s family threatened to sue the city of irving and the school district for civil rights violations and physical and mental anguish unless they received written apologies and compensation of 15 million in late 2015 his family decided to accept a scholarship from the qatar foundation and move to qatar partially because of unevidenced accusations of terrorist links and continued harassment from conspiracy theorists they returned to the dallas area on june 27 2016 saying they missed the relatives who had stayed in the u s and they will return to qatar in the fall
not be confused with aicardi goutières syndrome aicardi syndrome is a rare genetic malformation syndrome characterized by the partial or complete absence of a key structure in the brain called the corpus callosum the presence of retinal abnormalities and seizures in the form of infantile spasms aicardi syndrome is theorized to be caused by a defect on the x chromosome as it has thus far only been observed in girls or in boys with klinefelter syndrome confirmation of this theory awaits the discovery of a causative gene symptoms typically appear before a baby reaches about 5 months of age
aicardi – goutières syndrome ags which is completely distinct from the similarly named aicardi syndrome is a rare usually early onset childhood inflammatory disorder most typically affecting the brain and the skin neurodevelopmental disorder the majority of affected individuals experience significant intellectual and physical problems although this is not always the case the clinical features of ags can mimic those of in utero acquired infection and some characteristics of the condition also overlap with the autoimmune disease systemic lupus erythematosus sle following an original description of eight cases in 1984 the condition was first referred to as aicardi – goutières syndrome ags in 1992 and the first international meeting on ags was held in pavia italy in 2001 ags can occur due to mutations in any one of a number of different genes of which seven have been identified to date namely trex 1 rnaseh 2 a rnaseh 2 b rnaseh 2 c which together encode for the ribonuclease h 2 enzyme complex samhd 1 adar 1 and ifih 1 coding for mda 5 this neurological disease occurs in all populations worldwide although it is almost certainly under diagnosed to date 2014 at least 400 cases of ags are known
ainhum from portuguese pronounced īn yoom ´ i ´ num or ān ´ hum also known as dactylolysis spontanea is a painful constriction of the base of the fifth toe frequently followed by bilateral spontaneous autoamputation a few years later
an air embolism also known as a gas embolism is an embolism or blood vessel blockage caused by one or more bubbles of air or gas in the circulatory system air embolisms may also occur in the xylem of vascular plants especially when suffering from water stress divers can suffer from arterial gas embolisms venous gas embolisms usually get blocked by the lungs and so rarely cause a problem
an air lock is a restriction of or complete stoppage of liquid flow caused by gas trapped in a high point of a liquid filled pipe system the gas being less dense than the liquid rises to any high points when pressure is applied instead of the liquid flowing as it would if the system was full of liquid the system behaves like a series of manometers flushing the system with high flow or pressures can help move the gas away from the highest point or a tap or automatic vent valve can be installed to let the gas out air lock problems often occur when one is trying to recommission a system after it has been deliberately for servicing or accidentally emptied for example a central heating system using a circulating pump to pump water through radiators when filling such a system air is trapped in the radiators this air has to be vented using screw valves built into the radiators depending on the pipe layout if there are any upside down u s in the circuit it will be necessary to vent the highest point s if not air lock may stop flow through that part of the circuit completely note that circulating pumps usually do not generate enough pressure to overcome air locks fig 1 shows a reservoir which feeds a gravity distribution system – for drinking water or irrigation if the ground in which the pipe is laid has high points – such as hi 1 2 etc and low points between them such as lo 1 2 etc then if the pipe is filled from the top and was empty the pipe fills ok as far as hi 1 if the water flow velocity is below the rising velocity of air bubbles ref then water trickles down to the low point lo 2 and traps the remaining air between hi 1 and lo 2 as more water flows down the upward leg lo 2 to hi 2 fills up this exerts a pressure on the trapped air of either h 2 m of water wg water gauge or h 1 whichever is less if h 2 is greater than h 1 then you have a full air lock and the water level in the up leg lo 2 to hi 2 stops at h 1 and no further water can flow if h 1 is greater than h 2 then some water can flow but the full pipe hydraulic head h 3 will not be reached and so flow is much less than expected if there are further undulations then the back pressure effects add together obviously long pipelines over fairly level but undulating land are bound to have many such high and low points to avoid air or gas lock automatic vents are fitted which let air or gas out when above a certain pressure they may also be designed to let air in under vacuum there are many other design considerations for design of water pipeline systems e g the air lock phenomenon can be used in a number of useful ways the diagram to the right shows an s trap this has the properties a that liquid can flow from top 1 to bottom 4 unhindered and b that gas cannot flow through the trap unless it has enough extra pressure to overcome the liquid head of the trap this is usually about 75 to 100 mm of water and prevents foul smelling air coming back from foul water drainage systems via connections to toilets sinks and so on s traps work well unless the drainage water has sand in it which then collects in the u part of the s
air sparging also known as in situ air stripping and in situ volatilization is an in situ remediation technique used for the treatment of saturated soils and groundwater contaminated by volatile organic compounds vocs like petroleum hydrocarbons which is a widespread problem for the ground water and soil health
air stagnation is a phenomenon which occurs when an air mass remains over an area for an extended period due to light winds and lack of precipitation pollutants cannot be cleared from the air either gaseous like ozone or particulate like soot or dust subsidence produced directly under the subtropical ridge can lead to a buildup of particulates in urban areas under the ridge leading to widespread haze if the low level relative humidity rises towards 100 percent overnight fog can form in the united states the national weather service issues an air stagnation advisory when these conditions are likely to occur
airbag dermatitis also known as an airbag burn is caused skin irritation and trauma secondary to the deployment of airbags
aircraft hijacking also known as air piracy or aircraft piracy especially within the special aircraft jurisdiction of the united states and informally as skyjacking is the unlawful seizure of an aircraft by an individual or a group in most cases the pilot is forced to fly according to the orders of the hijackers occasionally however the hijackers have flown the aircraft themselves such as the september 11 attacks in at least three cases the plane was hijacked by the official pilot or co pilot unlike the typical hijackings of land vehicles or ships skyjacking is not usually committed for robbery or theft most aircraft hijackers intend to use the passengers as hostages either for monetary ransom or for some political or administrative concession by authorities various motives have driven such occurrences including demanding the release of certain inmates notably ic 814 highlighting the grievances of a particular community notably af 8969 or political asylum notably et 961 hijackers also have used aircraft as a weapon to target particular locations notably during the september 11 2001 attacks hijackings for hostages commonly produce an armed standoff during a period of negotiation between hijackers and authorities followed by some form of settlement settlements do not always meet the hijackers original demands if the hijackers demands are deemed too great and the perpetrators show no inclination to surrender authorities sometimes employ armed special forces to attempt a rescue of the hostages notably operation entebbe
aircraft upset is a dangerous condition in aircraft operations in which the flight attitude or airspeed of an aircraft is outside the normal bounds of operation for which it is designed this may result in the loss of control loc of the aircraft and sometimes the total loss of the aircraft itself loss of control may be due to turbulent weather pilot disorientation or a system failure the u s nasa aviation safety program defines upset prevention and upset recovery as to prevent loss of control accidents due to aircraft upset after inadvertently entering an extreme or abnormal flight attitude a boeing compiled list determined that 2 051 lives were lost in 22 accidents in the years 1998 – 2007 due to loc accidents ntsb data for 1994 – 2003 count 32 accidents and more than 2 100 lives lost worldwide
in mathematics and especially game theory the airport problem is a type of fair division problem in which it is decided how to distribute the cost of an airport runway among different players who need runways of different lengths the problem was introduced by s c littlechild and g owen in 1973 their proposed solution is 1 divide the cost of providing the minimum level of required facility for the smallest type of aircraft equally among the number of landings of all aircraft 2 divide the incremental cost of providing the minimum level of required facility for the second smallest type of aircraft above the cost of the smallest type equally among the number of landings of all but the smallest type of aircraft continue thus until finally the incremental cost of the largest type of aircraft is divided equally among the number of landings made by the largest aircraft type the authors note that the resulting set of landing charges is the shapley value for an appropriately defined game
airsickness is a sensation which is induced by air travel it is a specific form of motion sickness and is considered a normal response in healthy individuals airsickness occurs when the central nervous system receives conflicting messages from the body including the inner ear eyes and muscles affecting balance and equilibrium the inner ear is particularly important in the maintenance of balance and equilibrium because it contains sensors for both angular rotational and linear motion airsickness is usually a combination of spatial disorientation nausea and vomiting
airway obstruction is a blockage of respiration in the airway it can be broadly classified into being either in the upper airway or lower airway
in mathematics the airy zeta function studied by is a function analogous to the riemann zeta function and related to the zeros of the airy function
there are several akabori amino acid reactions which are named after shiro akabori 1900 – 1992 a japanese chemist in the first reaction an α amino acid is oxidised by heating it with an oxidizing sugar this reaction has been used to synthesize dichlorophthalimido derivatives for the analysis of peptides since the mass spectra of those derivatives are easily recognized file akabori png in the second reaction an α amino acids and esters are reduced by sodium amalgam and ethanolic hcl to give α amino aldehydes this process is conceptually similar to the bouveault – blanc reduction except that is pauses at the aldehyde stage file akabori 2 png
the akahoya eruption was the strongest known volcanic eruption of the kikai caldera in kyūshū japan it ejected about 150 cubic kilometres 36 cu mi of volcanic material giving it a 7 on the volcanic explosivity index the akahoya eruption is one of only six known eruptions reaching that magnitude during the holocene or the last twelve thousand years it dramatically changed vegetation in southern kyūshū archaeologically it has been dated around 7 300 cal bp during the earliest jōmon period but it has also been radiocarbon dated to 6 500 bp
akanye or akanje russian аканье russian pronunciation ˈakənʲjɪ is a phonological phenomenon in slavic languages in which the phoneme o or e is realized as more or less close to a it is a case of vowel reduction the most familiar example is probably russian akanye pronounced but not represented orthographically in the standard language akanye is also found in standard belarusian represented orthographically as well as in northern polissian ukrainian dialects slovene dialects e g lower carniolan dialects some subgroups of the kajkavian dialect of serbo croatian and bulgarian dialects e g the rhodope dialects including the smolyan dialect
akathisia is a movement disorder characterized by a feeling of inner restlessness and a compelling need to be in constant motion as well as by actions such as rocking while standing or sitting lifting the feet as if marching on the spot and crossing and uncrossing the legs while sitting people with akathisia are unable to sit or keep still complain of restlessness fidget rock from foot to foot and pace the term was coined by the czech neuropsychiatrist ladislav haskovec 1866 – 1944 who described the phenomenon in 1901 antipsychotics also known as neuroleptics particularly the first generation antipsychotics may cause akathisia other known causes include side effects of certain medications and nearly any physical dependence inducing drug during drug withdrawal it is also associated with parkinson s disease and related syndromes the term is from greek καθίζειν kathízein – to sit a indicating negation or absence lit inability to sit
akinetopsia greek a for without kine for to move and opsia for seeing also known as cerebral akinetopsia or motion blindness is a neuropsychological disorder in which a patient cannot perceive motion in his or her visual field despite being able to see stationary objects without issue there are varying degrees of akinetopsia from seeing motion as a cinema reel to an inability to discriminate any motion there is currently no effective treatment or cure for akinetopsia
aksharaaabhyasam or akshara abhyaasam or vidyaarambham is a traditional religious function in which the child is given initiation of education so that the child is ready to receive formal education this ritual involves goddess saraswati puja this ritual very common in hindu families of karnataka andhra pradesh and telangana akshara means letters alphabets and abhyasam means practice together they mean the study of practical letters the ceremony is performed by the maternal uncle mothers brothers father paternal uncle along with the family keeping the child in his lap holding the child ’ s right hand forefinger and make the child write the om followed by the panchaakshari mantra namah shivayaah om symbol which is treated as a beejaakshar beeja in sanskrit means the origin gnana saraswati temple in basar telangana is a popular temple where such ceremonies are held in large numbers this ceremony can be performed in temples and at the residence also
alabama rot or idiopathic cutaneous and renal glomerular vasculopathy crgv is a condition often fatal in dogs first identified in the usa in the 1980 s it is believed to be caused by toxins produced by bacteria such as escherichia coli commonly known as e coli this has little if any clinical evidence base the citation is written by a greyhound interest group founder and not backed up by any current scientific evidence pure speculation at best the initial symptoms are skin lesions on the legs chest and abdomen with eventual renal failure in about 25 of cases it was first noted in greyhounds in the us in november 2012 the first cases were identified in the uk in january 2014 the outbreak in england was identified as having the same or similar cause as alabama rot although a wide range of breeds were affected the disease has continued to spread across england with a case being reported as far north as north yorkshire in march 2015 a uk map posted online shows confirmed with post mortem and unconfirmed without post mortem cases of alabama rot since december 2012
alachryma is a disease of the autonomic nervous system where there is a lack of tear production
alacrima refers to an abnormality in tear production that could mean reduced tear production or absent tear production because a lack of tears presents in only in a few rare disorders it aids in diagnosis of these disorders including triple a syndrome and ngly 1 deficiency alacrima can be formally diagnosed through a schirmer s test
alagille syndrome is an autosomal dominant genetic disorder that affects the liver heart kidney and other systems of the body problems associated with the disorder generally become evident in infancy or early childhood the disorder is inherited in an autosomal dominant pattern and the estimated prevalence of alagille syndrome is 1 in every 100 000 live births it is named for daniel alagille
alay or 4 l 4 y anak layangan or anak lebay is an indonesian pop culture phenomenon it is a stereotype describing something tacky and cheesy norak or kampungan the alay culture phenomena spans a wide array of styles in music dress and messaging it has often been compared to that of the jejemon phenomenon originating from the philippines and harajuku from japan although the former emerged much later and the latter was even admired in the west
the albanian revolt of 1910 was reaction to the new centralization policies of the young turk ottoman government in albania it was the first of a series of major uprisings rebels were supported by the kingdom of serbia new taxes levied in the early months of 1910 led to isa boletini s activity to convince albanian leaders who had already been involved in a 1909 uprising to try another revolt against the ottoman empire the albanian attacks on the ottomans in priştine now pristina and ferizovik now ferizaj the killing of the ottoman commander in ipek now peć and the insurgents blocking of the railway to skopje at the kaçanik pass led to the ottoman government s declaration of martial law in the area after two weeks of fierce fighting the albanian forces withdrew to the drenica region whereas the ottoman army took possession of the cities of prizren and yakova now gjakova the ottomans retook ipek on 1 june 1910 and two months later they entered shkodër the reprisals against the albanian population included several summary executions and the burning of many villages and properties many schools were closed and publications in the albanian alphabet which had been approved two years earlier in the congress of monastir were declared illegal journalists and publishers were fined or sentenced to death
albert touraine 1883 – 1961 was a french dermatologist hypohidrotic ectodermal dysplasia or christ siemens touraine syndrome is named for him touraine solente gole syndrome is also named for him
albinism in humans is a congenital disorder characterized by the complete or partial absence of pigment in the skin hair and eyes albinism is associated with a number of vision defects such as photophobia nystagmus and amblyopia lack of skin pigmentation makes for more susceptibility to sunburn and skin cancers in rare cases such as chédiak – higashi syndrome albinism may be associated with deficiencies in the transportation of melanin granules this also affects essential granules present in immune cells leading to increased susceptibility to infection albinism results from inheritance of recessive gene alleles and is known to affect all vertebrates including humans it is due to absence or defect of tyrosinase a copper containing enzyme involved in the production of melanin it is the opposite of melanism unlike humans other animals have multiple pigments and for these albinism is considered to be a hereditary condition characterised by the absence of melanin in particular in the eyes skin hair scales feathers or cuticle while an organism with complete absence of melanin is called an albino an organism with only a diminished amount of melanin is described as leucistic or albinoid the term is from the latin albus white
albinism – deafness syndrome also known as woolf syndrome and ziprkowski – margolis syndrome is a condition characterized by congenital neural deafness and a severe or extreme piebald like phenotype with extensive areas of hypopigmentation a locus at xq 26 3 q 27 i has been suggested it has been suggested that it is a form of waardenburg syndrome type ii
an albino is a type of chess problem in which at some stage in the solution a white pawn beginning on its starting square makes each of its four possible moves one square forward two squares forward capture to the left and capture to the right when a black pawn exhibits similar activity it is instead termed a pickaninny a simple example of an albino is the problem to the right a mate in 2 white moves first and must checkmate black in two moves against any defense it is by camil seneca and was first published in the april 1949 edition of the bulletin ouvrier des echecs the first move of the solution or key is 1 nb 1 this threatens 2 ra 3 black has four ways to defend against this each of which leads to a different move of the white pawn after 1 bb 3 the only move that mates is 2 cxb 3 the pawn captures to the left after 1 bd 3 the only mate is 2 cxd 3 capturing to the right after 1 bb 5 only 2 c 3 will do forward one square 2 c 4 is no good because the b 4 square needs to be covered by the pawn now the white queen has been cut off after 1 bd 5 only 2 c 4 will do 2 c 3 is no good because black could play 2 bb 3 the albino pawn moves need not necessarily be in the post key play of the problem they can instead be tries moves which almost solve a problem but which fail to a single black defense the mate in 2 to the right which combines the albino with a pickaninny is an example it is by lev loshinsky and was published in moskau rostow in 1930 the key is 1 nfd 5 threatening 2 qf 4 with the variations 1 g 5 2 h 8 q 1 rxc 3 rxd 5 2 qf 5 and 1 rd 4 2 qxg 7 f 5 the main point of the problem however is in the albino tries each of which is refuted by a pickaninny defense the relevant variations are 1 exd 3 capture to the left threatens 2 nd 7 fails to 1 gxf 6 capture to the right 1 exf 3 capture to the right threatens 2 qg 5 and 2 f 4 fails to 1 gxh 6 capture to the left 1 e 3 one square forward threatens 2 qf 4 fails to 1 g 5 two squares forward 1 e 4 two squares forward threatens 2 qf 5 fails to 1 g 6 one square forward in each of these cases there are other ways for black to counter white s threat but the pickaninny move is the only one that doesn t give white a new mate for example after 1 exf 3 bg 6 prevents white s threats but is not any good because it allows 2 rxe 6 the nature of the albino theme is such that in orthodox chess there must be at least four variations to show the four different moves of the white pawn however if the rules of circe chess are applied the number of required variations can be reduced to two circe is a chess variant in which captured pieces rather than being removed from the board are returned to their home squares the problem to the right is an example it is by adrian storisteanu and was first published in the british chess magazine in 1977 the problem is a helpmate in 2 which means black moves first and cooperates with white to move to a position where black is in checkmate after white s second move this problem features grasshoppers represented here by inverted queens a fairy chess piece which moves along the same lines as a queen but which must hop over another piece friendly or enemy and land on the square immediately beyond there are two solutions to the problem note that in helpmates black s moves are given first 1 rd 3 c 3 2 gaxc 3 pc 2 cxd 3 ra 8 1 rb 3 c 4 2 gxc 4 pc 2 cxb 3 ra 8 the first solution has the white pawn moving forward one square then after its rebirth on c 2 capturing to the right the second solution has the pawn first moving two squares and then capturing to the left problems like this showing an albino with fewer than four variations are very unusual
albright hereditary osteodystrophy is form of osteodystrophy otherwise known as pseudohypoparathyroidism type 1 a
albuminuria is a pathological condition wherein the protein albumin is abnormally present in the urine it is a type of proteinuria albumin is one type of plasma protein found in the urine in normal subjects and in larger quantity in patients with kidney disease for a number of reasons clinical terminology is changing to focus on albuminuria rather than proteinuria
alcohol related brain damage is the damage that occurs to brain structures or function of the central nervous system as a result of the direct neurotoxic effects of alcohol intoxication or acute withdrawal the frontal lobes are the most damaged region of the brains of alcohol abusers but other regions of the brain are also affected the damage that occurs from heavy drinking high blood alcohol levels causes impairments in judgement and decision making and social skills these brain changes are linked to poor behavioural control and impulsivity which tend to worsen the existing addiction problem the problems of alcoholism are well known such as memory disorders liver disease high blood pressure muscle weakness heart problems anaemia low immune function disorders of the digestive system and pancreatic problems as well as depression unemployment and family problems including child abuse recently attention has been increasingly focused on binge drinking by adolescents and young adults due to neurochemical changes and brain damage which unlike with alcoholism can occur after a relatively short period of time the damage is particularly evident in the corticolimbic region this brain damage increases the risk of abnormalities in mood and cognitive abilities increases the risk of dementia and additionally binge drinkers have an increased risk of developing chronic alcoholism individuals who are impulsive are at high risk of addiction due to impaired behavioural control and increased sensation seeking behaviour alcohol abuse especially during adolescence causes or worsens executive functions in the frontal lobe this brain damage from alcohol actually increases impulsivity and therefore worsens the addictive disorder with prolonged abstinence neurogenesis occurs which can potentially reverse the damage from alcohol abuse
alcohol abuse is a previous psychiatric diagnosis in which there is recurring harmful use of ethanol despite its negative consequences in 2013 it was reclassified as alcohol use disorder alcoholism along with alcohol dependence there are two types of alcohol abuse those who have anti social and pleasure seeking tendencies and those who are anxiety ridden people who are able to go without drinking for long periods of time but are unable to control themselves once they start binge drinking is another form of alcohol abuse according to surveys the heaviest drinkers are the united kingdom s adolescents in 2013 139 000 deaths globally were directly due to alcohol abuse and an additional 384 000 to cirrhosis from excess alcohol consumption
excessive alcohol intake is associated with an elevated risk of alcoholic liver disease ald heart failure some cancers and accidental injury and is a leading cause of preventable death in industrialized countries however extensive research has shown that moderate alcohol intake is associated with health benefits including less cardiovascular disease diabetes hypertension and lower all cause mortality an understanding of the inverse relationship between alcohol consumption and atherosclerosis was understood as early as 1904 the observation of a lower risk of cardiovascular disease cvd in france despite a diet rich in saturated fat was labeled the french paradox while much concerning this paradox remains unclear some have suggested that the higher consumption of red wine in france results in lower cvd although the reduced incidence of cvd disease associated with moderate alcohol consumption is well established many physicians have been wary of promoting the use of alcohol for this benefit considering the many negative effects of excessive alcohol consumption
alcohol dependence is a previous psychiatric diagnosis in which an individual is physically or psychologically dependent upon drinking alcohol in 2013 it was reclassified as alcohol use disorder alcoholism along with alcohol abuse in dsm 5
alcohol flush reaction is a condition in which an individual develops flushes or blotches associated with erythema on the face neck shoulders and in some cases the entire body after consuming alcoholic beverages the reaction is the result of an accumulation of acetaldehyde a metabolic byproduct of the catabolic metabolism of alcohol and is caused by an acetaldehyde dehydrogenase deficiency this syndrome has been associated with an increased risk of esophageal cancer in those who drink it has also been associated with lower than average rates of alcoholism possibly due to its association with adverse effects after drinking alcohol because of the association with asian ancestry alcohol flush reaction has also been referred to by such informal names as asian flush syndrome asian flush and asian glow approximately 36 of east asians japanese chinese and koreans show a characteristic physiological response to drinking alcohol that includes facial flushing nausea and tachycardia
alcohol intoxication is a physiological state that may also include psychological alterations of consciousness induced by the ingestion of ethanol ethyl alcohol commonly known as drinking alcohol or just alcohol or methanol methyl or wood alcohol though with possibly serious side effects from the latter alcohol intoxication is the result of alcohol entering the bloodstream faster than it can be metabolized by the liver which breaks down the ethanol into non intoxicating byproducts some effects of alcohol intoxication such as euphoria and lowered social inhibitions are central to alcohol s desirability as a beverage and its history as one of the world s most widespread recreational drugs despite this widespread use and alcohol s legality in most countries many medical sources tend to describe any level of alcohol intoxication as a form of poisoning due to ethanol s damaging effects on the body in large doses some religions such as some forms of islam or mormonism consider alcohol intoxication to be a sin symptoms of alcohol intoxication include euphoria flushed skin and decreased social inhibition at lower doses with larger doses producing progressively severe impairments of balance muscle coordination ataxia and decision making ability potentially leading to violent or erratic behavior as well as nausea or vomiting from alcohol s disruptive effect on the semicircular canals of the inner ear and chemical irritation of the gastric mucosa sufficiently high levels of blood borne alcohol will cause coma and death from the depressive effects of alcohol upon the central nervous system
the direct oxidation of primary alcohols to carboxylic acids normally proceeds via the corresponding aldehyde which is transformed via an aldehyde hydrate r ch oh 2 by reaction with water before it can be further oxidized to the carboxylic acid often it is possible to interrupt the oxidation of a primary alcohol at the aldehyde level by performing the reaction in absence of water so that no aldehyde hydrate can be formed
alcohol withdrawal syndrome is a set of symptoms that can occur when an individual reduces or stops alcohol consumption after long periods of use prolonged and excessive use of alcohol leads to tolerance and physical dependence the withdrawal syndrome is largely a hyper excitable response of the central nervous system due to lack of alcohol symptoms typical of withdrawal include agitation delirium tremens dts and seizures sedative hypnotics such as alcohol are well known for their ability to cause physiological dependence this dependence is due to alcohol induced neuro adaptation withdrawal is characterized by neuropsychiatric excitability and autonomic disturbances dependence on other sedative hypnotics can increase the severity of the withdrawal syndrome about half of people with alcoholism will develop withdrawal symptoms upon reducing their use of these about three to five percent develop dts or have seizures
alcoholic cardiomyopathy is a disease in which the chronic long term abuse of alcohol i e ethanol leads to heart failure alcoholic cardiomyopathy is a type of dilated cardiomyopathy due to the direct toxic effects of alcohol on heart muscle the heart is unable to pump blood efficiently leading to heart failure it can affect other parts of the body if the heart failure is severe it is most common in males between the ages of 35 50
alcoholic hallucinosis or alcohol related psychosis or alcohol induced psychotic disorder is a complication of alcohol withdrawal in alcoholics descriptions of the condition date back to at least 1907 they can occur during acute intoxication or withdrawal with the potential of having delirium tremens alcohol hallucinosis is a rather uncommon alcohol induced psychotic disorder only being seen in chronic alcoholics who have many consecutive years of severe and heavy drinking during their lifetime alcoholic hallucinosis develops about 12 to 24 hours after the heavy drinking stops suddenly and can last for days it involves auditory and visual hallucinations most commonly accusatory or threatening voices the risk of developing alcoholic hallucinosis is increased by long term heavy alcohol abuse and the use of other drugs
alcoholic hepatitis is hepatitis inflammation of the liver due to excessive intake of alcohol it is usually found in association with fatty liver an early stage of alcoholic liver disease and may contribute to the progression of fibrosis leading to cirrhosis signs and symptoms of alcoholic hepatitis include jaundice ascites fluid accumulation in the abdominal cavity fatigue and hepatic encephalopathy brain dysfunction due to liver failure mild cases are self limiting but severe cases have a high risk of death severe cases may be treated with glucocorticoids
alcoholic liver disease is a term that encompasses the liver manifestations of alcohol overconsumption including fatty liver alcoholic hepatitis and chronic hepatitis with liver fibrosis or cirrhosis it is the major cause of liver disease in western countries although steatosis fatty liver will develop in any individual who consumes a large quantity of alcoholic beverages over a long period of time this process is transient and reversible of all chronic heavy drinkers only 15 – 20 develop hepatitis or cirrhosis which can occur concomitantly or in succession the mechanism behind this is not completely understood 80 of alcohol passes through the liver to be detoxified chronic consumption of alcohol results in the secretion of pro inflammatory cytokines tnf alpha interleukin 6 il 6 and interleukin 8 il 8 oxidative stress lipid peroxidation and acetaldehyde toxicity these factors cause inflammation apoptosis and eventually fibrosis of liver cells why this occurs in only a few individuals is still unclear additionally the liver has tremendous capacity to regenerate and even when 75 of hepatocytes are dead it continues to function as normal
alcoholic lung disease is disease of the lungs caused by excessive alcohol consumption the term alcoholic lung disease is not a generally accepted medical diagnosis and the association between alcohol abuse and acute lung injury remains largely unrecognized even by lung researchers chronic alcohol ingestion impairs multiple critical cellular functions in the lung these cellular impairments lead to increased susceptibility to serious complications from lung disease recent research cites alcoholic lung disease as comparable to liver disease in alcohol related mortality alcoholics have a higher risk of developing acute respiratory distress syndrome ards and experience higher rates of mortality from ards when compared to non alcoholics
alcoholic polyneuropathy a k a alcohol leg is a neurological disorder in which multiple peripheral nerves throughout the body malfunction simultaneously it is defined by axonal degeneration in neurons of both the sensory and motor systems and initially occurs at the distal ends of the longest axons in the body this nerve damage causes an individual to experience pain and motor weakness first in the feet and hands and then progressing centrally alcoholic polyneuropathy is caused primarily by chronic alcoholism however vitamin deficiencies are also known to contribute to its development this disease typically occurs in chronic alcoholics who have some sort of nutritional deficiency treatment may involve nutritional supplementation pain management abstaining from alcohol
alcoholic redirects here for alcoholic beverages see alcoholic beverage for the song by starsailor see alcoholic song alcoholism also known as alcohol use disorder aud is a broad term for any drinking of alcohol that results in problems it was previously divided into two types alcohol abuse and alcohol dependence in a medical context alcoholism is said to exist when two or more of the following conditions is present a person drinks large amounts over a long time period has difficulty cutting down acquiring and drinking alcohol takes up a great deal of time alcohol is strongly desired usage results in not fulfilling responsibilities usage results in social problems usage results in health problems usage results in risky situations withdrawal occurs when stopping and alcohol tolerance has occurred with use risky situations include drinking and driving or having unsafe sex among others alcohol use can affect all parts of the body but particularly affects the brain heart liver pancreas and immune system this can result in mental illness wernicke – korsakoff syndrome an irregular heart beat liver failure and an increase in the risk of cancer among other diseases drinking during pregnancy can cause damage to the baby resulting in fetal alcohol spectrum disorders generally women are more sensitive to alcohol s harmful physical and mental effects than men both environmental factors and genetics are associated with alcoholism with about half the risk attributed to each a person with a parent or sibling with alcoholism is three to four times more likely to be alcoholic themselves environmental factors include social cultural and behavioral influences high stress levels anxiety as well as inexpensive easily accessible alcohol increases risk people may continue to drink partly to prevent or improve symptoms of withdrawal a low level of withdrawal may last for months following stopping medically alcoholism is considered both a physical and mental illness both questionnaires and certain blood tests may detect people with possible alcoholism further information is then collected to confirm the diagnosis prevention of alcoholism is possible by regulating and limiting the sale of alcohol taxing alcohol to increase its cost and providing inexpensive treatment treatment may take several steps because of the medical problems that can occur during withdrawal alcohol detoxification should be carefully controlled one common method involves the use of benzodiazepine medications such as diazepam this can be either given while admitted to a health care institution or occasionally while a person remains in the community with close supervision other addictions or mental illness may complicate treatment after detoxification support such as group therapy or support groups are used to help keep a person from returning to drinking one commonly used form of support is the group alcoholics anonymous the medications acamprosate disulfiram or naltrexone may also be used to help prevent further drinking the world health organization estimates that as of 2010 there were 208 million people with alcoholism worldwide 4 1 of the population over 15 years of age in the united states about 17 million 7 of adults and 0 7 million 2 8 of those age 12 to 17 years of age are affected it is more common among males and young adults becoming less common in middle and old age it is the least common in africa at 1 1 and has the highest rates in eastern europe at 11 alcoholism directly resulted in 139 000 deaths in 2013 up from 112 000 deaths in 1990 a total of 3 3 million deaths 5 9 of all deaths are believed to be due to alcohol it often reduces a person s life expectancy by around ten years in the united states it resulted in economic costs of 224 billion usd in 2006 many terms some insulting and others informal have been used to refer to people affected by alcoholism including tippler drunkard dipsomaniac and souse in 1979 the world health organization discouraged the use of alcoholism due to its inexact meaning preferring alcohol dependence syndrome
an aldol condensation is an organic reaction in which an enol or an enolate ion reacts with a carbonyl compound to form a β hydroxyaldehyde or β hydroxyketone followed by a dehydration to give a conjugated enone aldol condensation overview aldol condensations are important in organic synthesis providing a good way to form carbon – carbon bonds for example the robinson annulation reaction sequence features an aldol condensation the wieland miescher ketone product is an important starting material for many organic syntheses aldol condensations are also commonly discussed in university level organic chemistry classes as a good bond forming reaction that demonstrates important reaction mechanisms in its usual form it involves the nucleophilic addition of a ketone enolate to an aldehyde to form a β hydroxy ketone or aldol aldehyde alcohol a structural unit found in many naturally occurring molecules and pharmaceuticals the aldol reaction the name aldol condensation is also commonly used especially in biochemistry to refer to just the first addition stage of the process — the aldol reaction itself — as catalyzed by aldolases however the aldol reaction is not formally a condensation reaction because it does not involve the loss of a small molecule the reaction between an aldehyde ketone and an aromatic carbonyl compound lacking an alpha hydrogen cross aldol condensation is called the claisen schmidt condensation this reaction is named after two of its pioneering investigators rainer ludwig claisen and j g schmidt who independently published on this topic in 1880 and 1881 an example is the synthesis of dibenzylideneacetone quantitative yields in claisen schmidt reactions have been reported in the absence of solvent using naoh as the base and cycloalkanones benzaldehydes
aldolase a deficiency also called aldoa deficiency or red cell aldolase deficiency is an autosomal recessive metabolic disorder resulting in a deficiency of the enzyme aldolase a which is found predominantly in red blood cells and muscle tissue it may lead to hemolytic anaemia as well as myopathy associated with exercise intolerance and rhabdomyolysis in some cases
the aldol – tishchenko reaction is a tandem reaction involving an aldol reaction and a tishchenko reaction in organic synthesis it is a method to convert aldehydes and ketones into 1 3 hydroxyl compounds the reaction sequence in many examples starts from conversion of a ketone into an enolate by action of lithium diisopropylamide lda the mono ester diol is then converted into the diol by a hydrolysis step with both the acetyl trimethylsilane and propiophenone as reactants the diol is obtained as a pure diastereoisomer aldol – tishchenko reaction starting from acetyl trimethylsilane and acetaldehydealdol – tishchenko reaction starting from propiophenone and acetaldehyde
alexander s band or alexander s dark band is an optical phenomenon associated with rainbows which was named after alexander of aphrodisias who first described it in 200 ad it occurs due to the deviation angles of the primary and secondary rainbows both bows exist due to an optical effect called the angle of minimum deviation the refractive index of water prevents light from being deviated at smaller angles the minimum deviation angle for the primary bow is 137 5 ° light can be deviated up to 180 ° causing it to be reflected right back to the observer light which is deviated at intermediate angles brightens the inside of the rainbow the minimum deviation angle for the secondary bow is about 230 ° the fact that this angle is greater than 180 ° makes the secondary bow an inside out version of the primary its colors are reversed and light which is deviated at greater angles brightens the sky outside the bow between the two bows lies an area of unlit sky referred to as alexander s band light which is reflected by raindrops in this region of the sky cannot reach the observer though it may contribute to a rainbow seen by another observer elsewhere
alexander disease also known as fibrinoid leukodystrophy is a progressive and fatal neurodegenerative disease it is a rare genetic disorder and mostly affects infants and children causing developmental delay and changes in physical characteristics
alexandre luiz goulart commonly known simply as alexandre born july 24 1976 in são joão del rei brazil is a brazilian football player alexandre appearance in two campeonato brasileiro matches for sport club internacional he spent several years playing football for boavista f c and c d nacional in the portuguese liga
alezzandrini syndrome is a very rare syndrome characterized by a unilateral degenerative retinitis followed after several months by ipsilateral vitiligo on the face and ipsilateral poliosis deafness may also be present
algaemia refers to the condition where green algae is found in the blood it has been observed in an immunocompetent patient after removal of a hickman catheter in cows it has been observed to be caused by prototheca blaschkeae in humans it has been observed to be caused by prototheca wickerhamii
an algal bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems and are recognized by the discoloration in the water from their pigments cyanobacteria blooms are often called blue green algae blooms which can injure animals or the ecology are called harmful algal blooms hab and can lead to fish die offs cities cutting off water to residents or states having to close fisheries
the algar – flynn – oyamada reaction is a chemical reaction whereby a chalcone undergoes an oxidative cyclization to form a flavonol the algar – flynn – oyamada reaction
algebraic enumeration is a subfield of enumeration that deals with finding exact formulas for the number of combinatorial objects of a given type rather than estimating this number asymptotically methods of finding these formulas include generating functions and the solution of recurrence relations
algorithmic cooling is a phenomenon in quantum computation in which the processing of certain types of computation results in negative entropy and thus a cooling effect the phenomenon is a result of the connection between thermodynamics and information theory in so far as information is encoded in physical systems it is subject to the laws of thermodynamics certain processes within computation require a change in entropy within the computing system as data must be stored as some kind of ordered structure like a localized charge in a capacitor so the erasure of data by destroying this order must involve an increase in disorder or entropy this means that the erasure of data releases heat this is landauer s principle reversible computing or adiabatic computing is a theoretical type of computing in which data is never erased it just changes state or is marked to be ignored in theory such a system would be able to hide data without releasing heat in the case of quantum entangled data or qubits it is possible for a computation to result in negative entropy actually transferring heat out of the computational system and so cooling it
algorithmic information theory is a subfield of information theory and computer science that concerns itself with the relationship between computation and information according to gregory chaitin it is the result of putting shannon s information theory and turing s computability theory into a cocktail shaker and shaking vigorously
in signal processing and related disciplines aliasing is an effect that causes different signals to become indistinguishable or aliases of one another when sampled it also refers to the distortion or artifact that results when the signal reconstructed from samples is different from the original continuous signal aliasing can occur in signals sampled in time for instance digital audio and is referred to as temporal aliasing aliasing can also occur in spatially sampled signals for instance moiré patterns in digital images aliasing in spatially sampled signals is called spatial aliasing aliasing is generally avoided by applying low pass filters anti aliasing filters to the analog signal before sampling
alice de lusignan countess of surrey 1224 – 9 february 1256 was a uterine half sister of king henry iii of england and the wife of john de warenne 6 th earl of surrey shortly after her arrival in england from france in 1247 her half brother arranged her marriage to the earl which incurred some resentment from the english nobility
alice in wonderland syndrome also known as todd s syndrome or lilliputian hallucinations is a disorienting neurological condition that affects human perception people experience micropsia macropsia pelopsia teleopsia or size distortion of other sensory modalities it is often associated with migraines brain tumors and the use of psychoactive drugs it can also be the initial symptom of the epstein – barr virus see mononucleosis anecdotal reports suggest that the symptoms are fairly common in childhood with many people growing out of them in their teens it appears that aiws is also a common experience at sleep onset and has been known to commonly arise due to a lack of sleep aiws can be caused by abnormal amounts of electrical activity causing abnormal blood flow in the parts of the brain that process visual perception and texture
alien hand syndrome ahs is a rare neurological disorder that causes hand movement without the person being aware of what is happening or having control over the action the afflicted person may sometimes reach for objects and manipulate them without wanting to do so even to the point of having to use the controllable hand to restrain the alien hand while under normal circumstances thought as intent and action can be assumed to be deeply mutually entangled the occurrence of alien hand syndrome can be usefully conceptualized as a phenomenon reflecting a functional disentanglement between thought and action alien hand syndrome is best documented in cases where a person has had the two hemispheres of their brain surgically separated a procedure sometimes used to relieve the symptoms of extreme cases of epilepsy it also occurs in some cases after brain surgery stroke infection tumor aneurysm and specific degenerative brain conditions such as alzheimer s disease and creutzfeldt – jakob disease other areas of the brain that are associated with alien hand syndrome are the frontal occipital and parietal lobes the first known case described in the medical literature appeared in a detailed case report published in german in 1908 by the preeminent german neuro psychiatrist kurt goldstein in this paper goldstein described a right handed woman who had suffered a stroke affecting her left side from which she had partially recovered by the time she was seen however her left arm seemed as though it belonged to another person and performed actions that appeared to occur independent of her will the patient complained of a feeling of strangeness in relationship to the goal directed movements of the left hand and insisted that someone else was moving the left hand and that she was not moving it herself goldstein reported that as a result of this report she was regarded at first as a paranoiac when the left hand grasped an object she could not voluntarily release it the somatic sensibility of the left side was reported to be impaired especially with aspects of sensation having to do with the orienting of the limb some spontaneous movements were noted to occur involving the left hand such as wiping the face or rubbing the eyes but these were relatively infrequent only with significant effort was she able to perform simple movements with the left arm in response to spoken command but these movements were performed slowly and often incompletely even if these same movements had been involuntarily performed with relative ease before while in the abnormal alien control mode based on these remarkable observations goldstein developed a doctrine of motor apraxia in which he discussed the process involved in the generation of voluntary action and interpreted these findings in the context of a proposed central structure organized around the perception and internal representation of the space time continuum encompassing memory will and other higher cognitive processes goldstein maintained that a unified conceptual organization and general gestalt of space time in which all aspects of relevant sensory perception of both the physical body i e via interoception and external space i e via exteroception were integrated was necessary both for object perception as well as for successful goal directed dynamic bodily action in relationship to extrapersonal space and the objects located therein in his classic papers reviewing the wide variety of disconnection syndromes associated with focal brain pathology norman geschwind commented that kurt goldstein was perhaps the first to stress the non unity of the personality in patients with callosal section and its possible psychiatric effects anarchic hand syndrome and alien hand syndrome are two similar but separate disorders in both there are unintended but purposeful and autonomous movements of the upper limb and intermanual conflict anarchic hand is usually diagnosed as opposed to alien hand syndrome because it tends to be more associated with motor impairments as the patients acknowledge the hand as theirs but are frustrated by its unintended actions in alien hand syndrome the individual tends to display more sensory deficits as they dissociate themselves from the hand and its actions frequently remarking on the hand s behaviour as if it does not belong to them
the alkali – silica reaction asr more commonly known as concrete cancer is a reaction which occurs over time in concrete between the highly alkaline cement paste and the reactive non crystalline amorphous silica found in many common aggregates given sufficient moisture this reaction causes the expansion of the altered aggregate by the formation of a swelling gel of calcium silicate hydrate c s h this gel increases in volume with water and exerts an expansive pressure inside the material causing spalling and loss of strength of the concrete finally leading to its failure asr can cause serious cracking in concrete resulting in critical structural problems that can even force the demolition of a particular structure
alkalosis is the result of a process reducing hydrogen ion concentration of arterial blood plasma alkalemia in contrast to acidemia serum ph 7 35 or lower alkalemia occurs when the serum ph is higher than normal 7 45 or higher alkalosis is usually divided into the categories of respiratory alkalosis and metabolic alkalosis or a combined respiratory metabolic alkalosis
alkane metathesis is a class of chemical reaction in which an alkane is rearranged to give a longer or shorter alkane product it is similar to olefin metathesis except that olefin metathesis cleaves and recreates a carbon carbon double bond but alkane methathesis operates on a carbon carbon single bond
alkaptonuria black urine disease black bone disease or alcaptonuria is a rare inherited genetic disorder in which the body cannot process the amino acids phenylalanine and tyrosine which occur in protein it is caused by a mutation in the hgd gene for the enzyme homogentisate 1 2 dioxygenase ec 1 13 11 5 if a person inherits abnormal copies from each parent it is a recessive condition the body accumulates an intermediate substance called homogentisic acid in the blood and tissues homogentisic acid and its oxidated form alkapton are excreted in the urine giving it an unusually dark color the accumulating homogentisic acid causes damage to cartilage ochronosis leading to osteoarthritis and heart valves as well as precipitating as kidney stones and stones in other organs symptoms usually develop in people over thirty years old although the dark discoloration of the urine is present from birth apart from treatment of the complications such as pain relief and joint replacement for the cartilage damage vitamin c has been used to reduce the ochronosis and lowering of the homogentisic acid levels may be attempted with a low protein diet recently the drug nitisinone has been found to suppress homogentisic acid production and research is ongoing as to whether it can improve symptoms alkaptonuria is a rare disease it occurs in one in 250 000 people but is more common in slovakia and the dominican republic
the reaction steps are reversible reactions and the reaction is driven to completion by removal of water by azeotropic distillation molecular sieves or titanium tetrachloride primary amines react through an unstable hemiaminal intermediate which then splits off water alkylimino de oxo bisubstitution secondary amines do not lose water easily because they do not have a proton available and instead they often react further to an aminal reaction of secondary amine with a carbonyl group or when an α carbonyl proton is present to an enamine enamine formation by reaction of amine with carbonyl in acidic environment the reaction product is an iminium salt by loss of water this reaction type is found in many heterocycle preparations for example the povarov reaction and the friedländer synthesis to quinolines because both components are so reactive a molecule does not carry an aldehyde and an amine group at the same time unless the amine group is fitted with a protective group as a further demonstration of reactivity one study explored the properties of an α formyl aziridine which was found to dimerize as an oxazolidine on formation from the corresponding ester by organic reduction with dibal formyl aziridine reactivity iminium ion formation is prohibited in this molecule because the azirine group and the formyl group are said to be orthogonal
alkynation is an addition reaction in organic synthesis where a metal acetylide reacts with a carbonyl group to form an α alkynyl alcohol when the acetylide is formed from acetylene the reaction forms an α ethynyl alcohol this process is often referred to as ethynylation
alkyne metathesis is an organic reaction involving the redistribution of alkyne chemical bonds this reaction is closely related to olefin metathesis metal catalyzed alkyne metathesis was first described in 1968 by bailey et al the bailey system utilized a mixture of tungsten and silicon oxides at temperatures as high as 450 ° c in 1974 mortreux reported the use of a homogeneous catalyst — molybdenum hexacarbonyl at 160 ° c — to observe an alkyne scrambling phenomenon in which an unsymmetrical alkyne equilibrates with its two symmetrical derivatives
an alkyne trimerisation reaction is a 2 2 2 cyclization reaction in which three alkyne molecules react to form an aromatic compound the reaction is pseudo pericyclic since it has not been observed to occur without the assistance of metal catalysis and the metal catalyst assembles the ring stepwise via intermediates which are not directly in between in a geometric sense the starting material and products
the alkyne zipper reaction is an organic reaction which isomerizes an organic compound containing an internal alkyne into a terminal alkyne this was first reported by charles allen brown and ayako yamashita in 1975 the isomerization reaction proceeds for straight chain alkynes and acetylinic alcohols and provides a useful approach for remote functionalization in long chain hydrocarbons the reaction requires a strong base the base used by brown and yamashita was potassium 1 3 diaminopropanide generated in situ by adding potassium hydride to the solvent 1 3 diaminopropane alternative approaches have been investigated due to the expensive and hazardous nature of potassium hydride ethylenediamine has been found to be an unsuitable replacement for 1 3 diaminopropane as an example for the synthesis of 9 decyn 1 ol from 2 decyn 1 ol the lithium salt of 1 3 diaminopropane in the presence of potassium tert butoxide affords yields of approximately 85 ho – ch 2 c ≡ c – ch 2 6 ch 3 → ho ch 2 8 – c ≡ ch
all you need is blood is the name of the first single released by mash up band beatallica a group known for their combination of beatles music and metallica lyrics and riffs the song is a parody of the beatles song all you need is love in the same tradition of the beatles the cover features the members of beatallica holding signs that read the song title in different languages and each track except for the last begins with a musical quote from a different national anthem the maxi single contains fourteen tracks each in a different language except for the last track which is a radio edit of the american english version beatallibangers fans worldwide submitted the lyrics which were used and unedited by the band it was released on may 20 2008 the japanese cd import version which includes a bonus track of the song in japanese was released by sony atv on oct 8 2008 as of oct 2008 beatallica has recorded and released 14 different language versions of this song and they have left the project as an on going endeavor beatallibangers worldwide may submit new language versions directly to the band via their website
the allais paradox is a choice problem designed by maurice allais to show an inconsistency of actual observed choices with the predictions of expected utility theory
allan – herndon – dudley syndrome is a rare x linked inherited disorder of brain development that causes moderate to severe intellectual disability and problems with movement this condition which occurs almost exclusively in males disrupts development from before birth allan – herndon – dudley syndrome which is named eponymously for william allan florence c dudley and c nash herndon results from a mutation of the thyroid hormone transporter mct 8 also referred to as slc 16 a 2 consecutively thyroid hormones are unable to enter the nervous system which depends on thyroid signaling for proper function and development
the allan – robinson reaction is the chemical reaction of o hydroxyaryl ketones with aromatic anhydrides to form flavones or isoflavones if aliphatic anhydrides are used coumarins can also be formed see kostanecki acylation
the allee effect is a phenomenon in biology characterized by a correlation between population size or density and the mean individual fitness often measured as per capita population growth rate of a population or species
allelic heterogeneity is the phenomenon in which different mutations at the same locus cause a similar phenotype these allelic variations can arise as a result of natural selection processes as a result of exogenous mutagens genetic drift or genetic migration many of these mutations take the form of single nucleotide polymorphisms in which a single nucleotide base is altered compared to a consensus sequence they can also exist as copy number variants cnv in which the copies of a gene or dna sequence is different from the population mutated alleles expressing allelic heterogeneity can be classified as adaptive or disadaptive these mutations can occur in the germ line cells somatic cells or in the mitochondrial mutations in germ line cells can be inherited as well as mitochondrial allelic mutations the mitochondrial allelic mutations are inherited maternally typically in the human genome a small amount of allele variants account for 75 of the mutations found at a particular locus within a population other variants found are considered to be rare or exclusive to a single pedigree the online mendelian inheritance of man has a record of over 1000 genes and their associated allelic variants these genes display allelic heterogeneity at their loci and are responsible for distinct disease phenotypes some of these diseases include alkaptonuria albinism achondroplasia and phenylketonuria for example β thalassemia may be caused by several different mutations in the β globin gene allelic heterogeneity should not be confused with locus heterogeneity in which a mutation at a different gene causes a similar phenotype nor should it be confused with phenotypic heterogeneity in which a mutation within the same gene causes a different phenotype other major diseases displaying allelic heterogeneity are allelic mutations in the dystrophin gene which cause duchenne dystrophy and mutations in the cftr gene that are known to causes cystic fibrosis
allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the germination growth survival and reproduction of other organisms these biochemicals are known as allelochemicals and can have beneficial positive allelopathy or detrimental negative allelopathy effects on the target organisms and the community allelochemicals are a subset of secondary metabolites which are not required for metabolism i e growth development and reproduction of the allelopathic organism allelochemicals with negative allelopathic effects are an important part of plant defense against herbivory the production of allelochemicals are affected by biotic factors such as nutrients available and abiotic factors such as temperature and ph allelopathy is characteristic of certain plants algae bacteria coral and fungi allelopathic interactions are an important factor in determining species distribution and abundance within plant communities and are also thought to be important in the success of many invasive plants for specific examples see spotted knapweed centaurea maculosa garlic mustard alliaria petiolata casuarina allocasuarina spp and nutsedge the process by which a plant acquires more of the available resources such as nutrients water or light from the environment without any chemical action on the surrounding plants is called resource competition this process is not negative allelopathy although both processes can act together to enhance the survival rate of the plant species
the allen – millar – trippett rearrangement is a ring expansion reaction in which a cyclic phosphine is transformed into a cyclic phosphine oxide this name reaction first reported in the 1960 s by david w allen ian t millar and stuart trippett occurs by alkylation or acylation of the phosphorus followed by reaction with hydroxide to give a rearranged product the hydroxide first attacks the phosphonium atom followed by collapse to the phosphine oxide with one of the groups migrating off of the phosphorus
allergic bronchopulmonary aspergillosis abpa is a condition characterised by an exaggerated response of the immune system a hypersensitivity response to the fungus aspergillus most commonly aspergillus fumigatus it occurs most often in patients with asthma or cystic fibrosis aspergillus spores are ubiquitous in soil and are commonly found in the sputum of healthy individuals a fumigatus is responsible for a spectrum of lung diseases known as aspergilloses abpa causes airway inflammation leading to bronchiectasis — a condition marked by abnormal dilation of the airways left untreated the immune system and fungal spores can damage sensitive lung tissues and lead to scarring the exact criteria for the diagnosis of abpa are not agreed upon chest x rays and ct scans raised blood levels of ige and eosinophils immunological tests for aspergillus together with sputum staining and sputum cultures can be useful treatment consists of corticosteroids and antifungal medications
allergic conjunctivitis is inflammation of the conjunctiva the membrane covering the white part of the eye due to allergy although allergens differ among patients the most common cause is hay fever symptoms consist of redness mainly due to vasodilation of the peripheral small blood vessels edema swelling of the conjunctiva itching and increased lacrimation production of tears if this is combined with rhinitis the condition is termed allergic rhinoconjunctivitis the symptoms are due to release of histamine and other active substances by mast cells which stimulate dilation of blood vessels irritate nerve endings and increase secretion of tears treatment of allergic conjunctivitis is by avoiding the allergen e g avoiding grass in bloom during hay fever season and treatment with antihistamines either topical in the form of eye drops or systemic in the form of tablets antihistamines medications that stabilize mast cells and non steroidal anti inflammatory drugs nsaids are generally safe and usually effective
allergic contact dermatitis acd is a form of contact dermatitis that is the manifestation of an allergic response caused by contact with a substance the other type being irritant contact dermatitis icd although less common than icd acd is accepted to be the most prevalent form of immunotoxicity found in humans by its allergic nature this form of contact dermatitis is a hypersensitive reaction that is atypical within the population the mechanisms by which these reactions occur are complex with many levels of fine control their immunology centres on the interaction of immunoregulatory cytokines and discrete subpopulations of t lymphocytes
an allergic response is a hypersensitive immune reaction to a substance that normally is harmless or would not cause an immune response in everyone an allergic response may cause harmful symptoms such as itching or inflammation or tissue injury
allergic rhinitis also known as hay fever is a type of inflammation in the nose which occurs when the immune system overreacts to allergens in the air signs and symptoms include a runny or stuffy nose sneezing red itchy and watery eyes and swelling around the eyes the fluid from the nose is usually clear symptom onset is often within minutes following exposure and they can affect sleep the ability to work and the ability to concentrate at school those whose symptoms are due to pollen typically develop symptoms during specific times of the year many people with allergic rhinitis also have asthma allergic conjunctivitis or atopic dermatitis allergic rhinitis is typically triggered by environmental allergens such as pollen pet hair dust or mold inherited genetics and environmental exposures contribute to the development of allergies growing up on a farm and having multiple siblings decreases the risk the underlying mechanism involves ige antibodies attaching to the allergen and causing the release of inflammatory chemicals such as histamine from mast cells diagnosis is usually based on a medical history in combination with a skin prick test or blood tests for allergen specific ige antibodies these tests however are sometimes falsely positive the symptoms of allergies resemble those of the common cold however they often last for more than two weeks and typically do not include a fever exposure to animals in early life might reduce the risk of developing allergies to them later a number of medications may improve symptoms including nasal steroids antihistamines such as diphenhydramine cromolyn sodium and leukotriene receptor antagonists such as montelukast medications are however not sufficient or associated with side effects in many people exposing people to larger and larger amounts of allergen known as allergen immunotherapy is often effective the allergen may be given as injections just under the skin or as a tablet under the tongue treatment typically lasts three to five years after which benefits may be prolonged allergic rhinitis is the type of allergy that affects the greatest number of people in western countries between 10 – 30 of people are affected in a given year it is most common between the ages of twenty and forty the first accurate description is from the 10 th century physician rhazes pollen was identified as the cause in 1859 by charles blackley in 1906 the mechanism was determined by clemens von pirquet the link with hay came about due to an early and incorrect theory that the symptoms were brought about by the smell of new hay
allergies also known as allergic diseases are a number of conditions caused by hypersensitivity of the immune system to something in the environment that usually causes little or no problem in most people these diseases include hay fever food allergies atopic dermatitis allergic asthma and anaphylaxis symptoms may include red eyes an itchy rash runny nose shortness of breath or swelling food intolerances and food poisoning are separate conditions common allergens include pollen and certain food metals and other substances may also cause problems food insect stings and medications are common causes of severe reactions their development is due to both genetic and environmental factors the underlying mechanism involves immunoglobulin e antibodies ige part of the body s immune system binding to an allergen and then to a receptor on mast cells or basophils where it triggers the release of inflammatory chemicals such as histamine diagnosis is typically based on a person s medical history further testing of the skin or blood may be useful in certain cases positive tests however may not mean there is a significant allergy to the substance in question early exposure to potential allergens may be protective treatments for allergies include avoiding known allergens and the use of medications such as steroids and antihistamines in severe reactions injectable adrenaline epinephrine is recommended allergen immunotherapy which gradually exposes people to larger and larger amounts of allergen is useful for some types of allergies such as hay fever and reactions to insect bites its use in food allergies is unclear allergies are common in the developed world about 20 of people are affected by allergic rhinitis about 6 of people have at least one food allergy and about 20 have atopic dermatitis at some point in time depending on the country about 1 – 18 of people have asthma anaphylaxis occurs in between 0 05 – 2 of people rates of many allergic diseases appear to be increasing the word allergy was first used by clemens von pirquet in 1906
cat allergy in humans is an allergic reaction to one or more allergens produced by cats the most common of these allergens are the glycoprotein fel d 1 secreted by the cat s sebaceous glands and fel d 4 which is expressed in saliva an allergic reaction is a histamine reaction that is usually characterized by coughing wheezing chest tightening itching nasal congestion rash watering eyes sneezing chapped lips and similar symptoms in some severe cases reactions may progress rapidly to cause the victim s airway to become inflamed and close up requiring emergency medical attention those with severe life threatening cat allergies face tremendous challenges due to lack of public awareness about anaphylactic cat allergies and do not enjoy the same conscientiousness from the public as those with a food allergy might due to widespread knowledge of allergies to allergens such as nuts or dairy
allochiria from the greek meaning other hand is a neurological disorder in which the patient responds to stimuli presented to one side of their body as if the stimuli had been presented at the opposite side it is associated with spatial transpositions usually symmetrical of stimuli from one side of the body or of the space to the opposite one thus a touch to the left side of the body will be reported as a touch to the right side which is also known as somatosensory allochiria if the auditory or visual senses are affected sounds a person s voice for instance will be reported as being heard on the opposite side to that on which they occur and objects presented visually will be reported as having been presented on the opposite side often patients may express allochiria in their drawing while copying an image allochiria often co occurs with unilateral neglect and like hemispatial neglect the disorder arises commonly from damage to the right parietal lobe allochiria is often confused with alloesthesia also known as false allochiria true allochiria is a symptom of dyschiria and unilateral neglect dyschiria is a disorder in the localization of sensation due to various degrees of dissociation and cause impairment in one side causing the inability to tell which side of the body was touched
allodynia ancient greek άλλος állos other and οδύνη odúnē pain refers to central pain sensitization increased response of neurons following painful often repetitive stimulation allodynia can lead to the triggering of a pain response from stimuli which do not normally provoke pain temperature or physical stimuli can provoke allodynia which may feel like a burning sensation and it often occurs after injury to a site allodynia is different from hyperalgesia an extreme exaggerated reaction to a stimulus which is normally painful
allopurinol hypersensitivity syndrome typically occurs in persons with preexisting kidney failure weeks to months after allopurinol is begun the patient develops a morbilliform eruption
allorecognition is the ability of an individual organism to distinguish its own tissues from those of another it manifests itself in the recognition of antigens expressed on the surface of cells of non self origin allorecognition has been described in nearly all multicellular phyla this article focuses on allorecognition from the standpoint of its significance in the evolution of multicellular organisms for other articles which focus on its importance in medicine molecular biology and so forth the following topics are recommended as well as those in the categories links at the bottom of this page immune system immunology transplant rejection tissue typing major histocompatibility complex mhc the ability to discriminate between self and non self is a fundamental requirement for life at the most basic level even single celled organisms need to be able to distinguish between food and non food to respond appropriately to invading pathogens and to avoid cannibalism in sexually reproducing organisms self non self discrimination is essential to ensuring species specific egg sperm interaction during fertilization hermaphroditic organisms such as annelids and certain plants require recognition mechanisms to prevent self fertilization such functions are all carried out by the innate immune system which employs evolutionarily conserved pattern recognition receptors to eliminate cells displaying nonself markers
an allowance is an amount of money given or allotted usually at regular intervals for a specific purpose in the context of children parents may provide an allowance british english pocket money to their child for their miscellaneous personal spending in the construction industry it may be an amount allocated to a specific item of work as part of an overall contract the person providing the allowance is usually trying to control how or when money is spent by the recipient so that it meets the aims of the person providing the money for example an allowance by a parent might be motivated to teach the child money management and may be unconditional or be tied to completion of chores or achievement of specific grades the person supplying the allowance usually specifies the purpose and may put controls in place to make sure that the money is spent for that purpose only for example a company employee may be given an allowance or per diem to provide for meals and travel when working away from home and may then be required to provide receipts as proof or they are provided with specific non money tokens or vouchers that can be used only for a specific purpose such as a meal voucher
allumwandlung german for complete promotion sometimes abbreviated auw is a chess problem where at some stage in the solution a pawn or sometimes pawns is promoted variously to a queen rook bishop and knight allumwandlung s main requirement is promotion either a white pawn or a black pawn a babson task may appear if both pawns are spotted in an individual problem corresponding one another
an allylic rearrangement or allylic shift is an organic reaction in which the double bond in an allyl chemical compound shifts to the next carbon atom it is encountered in nucleophilic substitution in reaction conditions that favor a sn 1 reaction mechanism the intermediate is a carbocation for which several resonance structures are possible this explains the product distribution or product spread after recombination with nucleophile y this type of process is called an sn 1 substitution alternatively it is possible for nucleophile to attack directly at the allylic position displacing the leaving group in a single step in a process referred to as sn 2 substitution this is likely in cases when the allyl compound is unhindered and a strong nucleophile is used the products will be similar to those seen with sn 1 substitution thus reaction of 1 chloro 2 butene with sodium hydroxide gives a mixture of 2 buten 1 ol and 3 buten 2 ol reaction of 1 chloro 2 butene with sodium hydroxide nevertheless the product in which the oh group is on the primary atom is minor in the substitution of 1 chloro 3 methyl 2 butene the tertiary 2 methyl 3 buten 2 ol is produced in a yield of 85 while that for the primary 3 methyl 2 buten 1 ol is 15 in one reaction mechanism the nucleophile attacks not directly at the electrophilic site but in a conjugate addition over the double bond sn 2 accent reaction mechanism
in psychology alogia greek ἀ “ without ” and λόγος “ speech ” or poverty of speech is a general lack of additional unprompted content seen in normal speech as a symptom it is commonly seen in patients suffering from schizophrenia and is considered as a negative symptom it can complicate psychotherapy severely because of the considerable difficulty in holding a fluent conversation alogia is often considered a form of aphasia which is a general impairment in linguistic ability it often occurs with intellectual disability and dementia as a result of damage to the left hemisphere of the brain people can revert to alogia as a way of reverse psychology or avoiding questions
alopecia areata also known as spot baldness is an autoimmune disease in which hair is lost from some or all areas of the body usually from the scalp due to the body s failure to recognize its own body cells and subsequent destruction of its own tissue often it results in bald spots on the scalp especially in the first stages in 1 – 2 of cases the condition can spread to the entire scalp alopecia totalis or to the entire skin alopecia universalis there are two types 1 scarring alopecia where there is fibrosis inflammation and loss of hair follicles and 2 nonscarring alopecia where the hair shafts are gone but the hair follicles are preserved making this type of alopecia reversible conditions resembling alopecia areata and having a similar cause occur also in other species
alopecia contractures dwarfism mental retardation or acd mental retardation syndrome is a developmental disorder which causes mainly baldness and dwarfism in combination with intellectual disability skeletal anomalies caries and nearsightedness are also typical the acd mental retardation syndrome was first described in 1980 by albert schinzel and only few cases have since been identified in the world at the time dr schinzel made no conclusion of the hereditary pattern of this syndrome but similarities between cases reported by year 2000 seem to suggest autosomal or x linked recessive inheritance or possibly a dominant mutation caused by mosaicism as causes of this syndrome
alopecia is a disease which can affect other animals besides humans development of alopecia in animals is usually the sign of an underlying disease some animals may be genetically predisposed to hair loss while in some it may be caused by hypersensitivity or nutritional factors canine pinnal alopecia is most common in dachshunds but others such as chihuahuas boston terriers whippets and italian greyhounds may also be vulnerable certain skin conditions in animals can also cause loss of fur ferret adrenal disease is extremely common and is the most common cause of alopecia in ferrets typically affecting middle aged specimens between three and seven years old bacterial pyoderma dermatophytosis and parasites can also cause the condition in rabbits dermatophytosis is a prime cause of alopecia in young newly weaned specimens dermatophytosis as a cause of alopecia is common in cats too and in long haired varieties dermatophytic pseudomycetomas may be to blame alopecia areata has been studied on mice in laboratories in horses human contact with the horse and the rubbing of the saddle across the mane can cause patches of hair loss
alopecia mucinosa also known as follicular mucinosis mucinosis follicularis pinkus ’ follicular mucinosis and pinkus ’ follicular mucinosis – benign primary form is a skin disorder that generally presents but not exclusively as erythematous plaques or flat patches without hair primarily on the scalp and face this can also present on the body as a follicular mucinosis and may represent a systemic disease
alopecia totalis is the loss of all skull and facial hair its causes are unclear but believed to be autoimmune
alopecia universalis au or alopecia areata universalis is a medical condition involving loss of all hair including eyebrows and eyelashes it is an advanced form of alopecia areata
alpenglow from german alpenglühen is an optical phenomenon in which a horizontal red glowing band is observed on the horizon opposite to the sun this effect occurs when the sun is just below the horizon alpenglow is easiest to observe when mountains are illuminated but can also be observed when the sky is illuminated through backscattering since the sun is below the horizon there is no direct path for the light to reach the mountain unlike sunset or sunrise the light that causes alpenglow is reflected off airborne snow water or ice particles low in the atmosphere these conditions differentiate between a normal sunrise or sunset and alpenglow although the term may be loosely applied to any sunrise or sunset light seen on the mountains true alpenglow is not direct sunlight and is only observed after sunset or before sunrise in the absence of mountains the aerosols in the eastern portion of the sky can be illuminated in the same way at sunset by the remaining red scattered light straddling the border of the earth s own shadow the terminator this back scattered light produces a red band opposite the sun
alpers disease also called alpers syndrome alpers huttenlocher syndrome ahs progressive sclerosing poliodystrophy and progressive infantile poliodystrophy is a progressive degenerative disease of the central nervous system first recognized by alfons maria jakob a german neuropathologist that occurs mostly in infants and children it is an autosomal recessive disorder caused by certain genetic mutations in the polg gene
alpha aminoadipic and alpha ketoadipic aciduria is an autosomal recessive metabolic disorder characterized by an increased urinary excretion of alpha ketoadipic acid and alpha aminoadipic acid it is caused by mutations in dhtkd 1 which encodes the e 1 subunit of the alpha ketoadipic acid dehydrogenase complex
alpha gal allergy or colloquially meat allergy is a reaction to galactose alpha 1 3 galactose whereby the body is overloaded with immunoglobulin e antibodies on contact with the carbohydrate the alpha gal molecule is found in all mammals apart from old world monkeys and the apes including humans bites from the lone star tick or the chigger which transfer this carbohydrate to the victim have been implicated in the development of this delayed allergic response which is triggered by the consumption of mammalian meat products despite myths to the contrary an alpha gal allergy does not require the afflicted to become a vegetarian as poultry and fish do not trigger a reaction the allergy most often occurs in the central and southern united states which corresponds to the distribution of the lone star tick in the southern united states where the tick is most prevalent allergy rates are 32 higher than elsewhere however as doctors are not required to report the number of patients suffering the alpha gal allergies the true number of affected individuals is unknown
alpha mannosidosis is a lysosomal storage disorder caused by deficient activity of the enzyme alpha d mannosidase in humans it is known to be caused by an autosomal recessive genetic mutation in livestock it is caused by chronic poisoning with swainsonine from locoweed
alpha thalassemia α thalassemia α thalassaemia is a form of thalassemia involving the genes hba 1 and hba 2 alpha thalassemia is due to impaired production of alpha chains from 1 2 3 or all 4 of the alpha globin genes leading to a relative excess of beta globin chains the degree of impairment is based on which clinical phenotype is present how many genes are affected
alpha thalassemia mental retardation syndrome atrx also called alpha thalassemia x linked mental retardation nondeletion type or atr x syndrome is a condition caused by a mutated gene females with this mutated gene have no specific signs or features but may demonstrate skewed x chromosome inactivation hemizygous males tend to be moderately intellectually disabled and have physical characteristics including coarse facial features microcephaly small head size hypertelorism widely spaced eyes a depressed nasal bridge a tented upper lip and an everted lower lip mild or moderate anemia associated with alpha thalassemia is part of the condition it is associated with atrx
alpha 1 antitrypsin deficiency α 1 antitrypsin deficiency a 1 ad is a genetic disorder that causes defective production of alpha 1 antitrypsin a 1 at leading to decreased a 1 at activity in the blood and lungs and deposition of excessive abnormal a 1 at protein in liver cells there are several forms and degrees of deficiency the form and degree depend on whether the sufferer has one or two copies of a defective allele in the literature it has been described as either a recessive or co dominant trait as there is some evidence that smoking heterozygotes are affected severe a 1 at deficiency causes panacinar emphysema or copd in adult life in many people with the condition especially if they are exposed to cigarette smoke the disorder can lead to various liver diseases in a minority of children and adults and occasionally more unusual problems it is treated through avoidance of damaging inhalants and in severe cases by intravenous infusions of the a 1 at protein or by transplantation of the liver or lungs it usually produces some degree of disability and reduces life expectancy
alport syndrome is a genetic disorder affecting around 1 in 50 000 children characterized by glomerulonephritis end stage kidney disease and hearing loss alport syndrome can also affect the eyes though the changes do not usually affect sight except when changes to the lens occur in later life blood in urine is universal proteinuria is a feature as kidney disease progresses the disorder was first identified in a british family by university of edinburgh medical school graduate cecil a alport in 1927 alport syndrome once also had the label hereditary nephritis but this is misleading as there are many other causes of hereditary kidney disease and nephritis alport syndrome is caused by an inherited defect in type iv collagen — a structural material that is needed for the normal function of different parts of the body since type iv collagen is found in the ears eyes and kidneys this explains why alport syndrome affects different seemingly unrelated parts of the body ears eyes kidneys etc
alström syndrome also called alstrom halgren syndrome is a rare genetic disorder caused by mutations in the gene alms 1 it is among the rarest genetic disorders in the world as currently it has only 266 reported cases in medical literature and over 501 known cases in 47 countries it was first described by carl henry alström in sweden in 1959 alstrom syndrome is sometimes confused with bardet biedl syndrome which has similar symptoms bardet biedl syndrome tends to have later onset in its symptoms the likelihood of two carrier parents both passing the gene and therefore having a child affected by the syndrome is 25 with each pregnancy the likelihood of having a child who is only a carrier of the gene is 50 with each pregnancy the likelihood of a child receiving normal genes from both parents and being considered to be genetically normal is 25 the risk for carrying the gene is equivalent for both males and females according to a 2007 article by joy et al published in the orphanet journal of rare diseases alström syndrome as is a rare autosomal recessive disease characterized by multiorgan dysfunction the key features are childhood obesity blindness due to congenital retinal dystrophy and sensorineural hearing loss associated endocrinologic features include hyperinsulinemia early onset type 2 diabetes and hypertriglyceridemia thus as shares several features with the common metabolic syndrome namely obesity hyperinsulinemia and hypertriglyceridemia mutations in the alms 1 gene have been found to be causative for as with a total of 79 disease causing mutations having been described prevalence estimates have ranged from 1 in 10 000 to fewer than 1 in 1 000 000 individuals in the general population
alternaria black spot of canola or grey leaf spot is an ascomycete fungal disease caused by a group of pathogens including alternaria brassicae a alternata and a raphani this pathogen is characterized by dark sunken lesions of various size on all parts of the plant including the leaves stem and pods its primary economic host is canola in its early stages it only affects the plants slightly by reducing photosynthesis however as the plant matures it can cause damage to the seeds and more reducing oil yield as well
alternariosis is an infection by alternaria presenting cutaneously as focal ulcerated papules and plaques treatment with itraconazole has been reported
alternating hemiplegia refers to a form of hemiplegia that has an ipsilateral and contralateral presentation in different parts of the body the disorder is characterized by recurrent episodes of paralysis on one side of the body there are multiple forms of alternating hemiplegia weber s syndrome middle alternating hemiplegia and inferior alternating hemiplegia this type of syndrome can result from a unilateral lesion in the brainstem affecting both upper motor neurons and lower motor neurons the muscles that would receive signals from these damaged upper motor neurons result in spastic paralysis with a lesion in the brainstem this affects the majority of limb and trunk muscles on the contralateral side due to the upper motor neurons decussation after the brainstem the cranial nerves and cranial nerve nuclei are also located in the brainstem making them susceptible to damage from a brainstem lesion cranial nerves iii oculomotor vi abducens and xii hypoglossal are most often associated with this syndrome given their close proximity with the pyramidal tract the location which upper motor neurons are in on their way to the spinal cord damages to these structures produce the ipsilateral presentation of paralysis or palsy due to the lack of cranial nerve decussation aside from the trochlear nerve before innervating their target muscles the paralysis may be brief or it may last for several days many times the episodes will resolve after sleep some common symptoms of alternating hemiplegia are mental impairment gait and balance difficulties excessive sweating and changes in body temperature
alternating hemiplegia of childhood ahc is a rare neurological disorder of uncertain etiology though growing evidence strongly supports mutation of the atp 1 a 3 gene as the primary cause of this disease ahc is named for the transient episodes often referred to as attacks or episodes of hemiplegia from which those with the disorder suffer these hemiplegic attacks can cause anything from mild weakness to complete paralysis on one or both sides of the body and they can vary greatly in duration attacks may also alternate from one side of the body to the other or alternate between affecting one or both sides during a single attack ahc is associated with many symptoms besides hemiplegia and the majority of these become apparent in early infancy ahc typically presents before the age of 18 months normally hemiplegia and other associated symptoms cease completely with sleep but they may recur upon waking the disorder was only recently discovered having first been characterized in 1971 ahc is also extremely rare – approximately 1 in 1 000 000 people have this disorder besides hemiplegia symptoms of the disorder include an extremely broad range of neurological and developmental impairments which are not well understood much of the literature about ahc is purposefully vague in this respect due to a lack of information on the disorder
in linguistics an alternation is the phenomenon of a phoneme or morpheme exhibiting variation in its phonological realization each of the various realizations is called an alternant the variation may be conditioned by the phonological morphological and or syntactic environment in which the morpheme finds itself alternations provide linguists with data that allow them to determine the allophones and allomorphs of a language s phonemes and morphemes and to develop analyses determining the distribution of those allophones and allomorphs
the altiplano de granada granada high plains is a spectrum of landscapes located in the northern part of the granada province within andalucia in southern spain it is made up of two municipal territories baza and huéscar
altitude sickness — also known as acute mountain sickness ams is a pathological effect of high altitude on humans caused by acute exposure to low partial pressure of oxygen at high altitude although minor symptoms such as breathlessness may occur at altitudes of 1 500 metres 5 000 ft ams commonly occurs above 2 400 metres 8 000 ft it presents as a collection of nonspecific symptoms acquired at high altitude or in low air pressure resembling a case of flu carbon monoxide poisoning or a hangover it is hard to determine who will be affected by altitude sickness as there are no specific factors that correlate with a susceptibility to altitude sickness however most people can ascend to 2 400 metres 8 000 ft without difficulty acute mountain sickness can progress to high altitude pulmonary edema hape or high altitude cerebral edema hace which are potentially fatal chronic mountain sickness also known as monge s disease is a different condition that only occurs after very prolonged exposure to high altitude
aluminium toxicity is a problem for patients on haemodialysis the dialysis process does not efficiently remove excess aluminium from the body so it may build up over time aluminium is a potentially toxic metal and aluminium poisoning may lead to mainly three disorders aluminium induced bone disease microcytic anemia and neurological dysfunction encephalopathy such conditions are more prominently observed in patients with chronic renal failure and especially in patients on haemodialysis about 5 – 10 mg of aluminium enters our body daily through different sources like water food occupational exposure to aluminium in industries etc in patients with normal renal function serum aluminium is normally lower than 6 microgram l baseline levels of serum aluminium should be 20 microgram l according to aami standards aluminum levels in the dialysis fluid should be less than 0 01 milligram l
aluminosis is a restrictive lung disease caused by exposure to aluminum bearing dust aluminosis can be detected by using high resolution computed tomography hrct
aluminothermic reactions are exothermic chemical reactions using aluminium as the reducing agent at high temperature the process is industrially useful for production of alloys of iron the most prominent example is the thermite reaction between iron oxides and aluminium to produce iron itself fe 2 o 3 2 al → 2 fe al 2 o 3 this specific reaction is however not relevant to the most important application of aluminothermic reactions the production of ferroalloys for the production of iron a cheaper reducing agent coke is used instead via the carbothermic reaction
alvarez s syndrome is a medical disorder in which the abdomen becomes bloated without any obvious reason such as intestinal gas it may be caused when the muscles of the superior abdominal wall contract and push the contents of the abdomen inferiorly and anteriorly it may be a psychogenic disorder it was discovered by and named for dr walter c alvarez in the late 1940 s
alveolar capillary dysplasia acd also congenital alveolar dysplasia is a very rare congenital malformation involving abnormal development of the capillary vascular system around the alveoli of the lungs it is a rare cause of persistent pulmonary hypertension in infants it also may be a rare cause of pulmonary hypoplasia babies with acd may appear normal at birth but within minutes or hours they develop respiratory distress with persistent pulmonary hypertension acd does not respond to standard therapies that resolve simple pulmonary hypertension the lack of response is an important diagnostic clue
alveolar hydatid disease ahd also known as alveolar echinococcosis alveolar colloid of the liver alveolococcosis multilocular echinococcosis and small fox tapeworm is a form of echinococcosis and is a disease that originates from a parasite although alveolar echinococcosis is rarely diagnosed in humans and is not as widespread as cystic echinococcosis it is also still a serious disease that not only has a significantly high fatality rate but also has the potential to become an emerging disease in many countries
alveolar osteitis is inflammation of the alveolar bone i e the alveolar process of the maxilla or mandible classically this occurs as a postoperative complication of tooth extraction alveolar osteitis usually occurs where the blood clot fails to form or is lost from the socket i e the defect left in the gum when a tooth is taken out this leaves an empty socket where bone is exposed to the oral cavity causing a localized alveolar osteitis limited to the lamina dura i e the bone which lines the socket this specific type of alveolar osteitis is also known as dry socket or less commonly fibrinolytic alveolitis and is associated with increased pain and delayed healing time dry socket occurs in about 0 5 – 5 of routine dental extractions and in about 25 – 30 of extractions of impacted mandibular third molars wisdom teeth which are buried in the bone
alveolar pressure palv is the pressure of air inside the lung alveoli when the glottis is opened and no air is flowing into or out of the lungs alveolar pressure is equal atmospheric pressure zero cmh 2 o
alveolar rhabdomyosarcoma is a type of rhabdomyosarcoma characterized by its appearance which is similar to the alveoli of the lungs it can be associated with a fusion protein between pax 3 and fkhr now known as foxo 1 it can also be associated with pax 7 fkhr
alveolar soft part sarcoma abbreviated asps is a very rare type of soft tissue sarcoma that grows slowly and whose cell of origin is unknown it arises mainly in children and young adults asps can migrate metastasize into other parts of the body typically the lungs and the brain asps is a sarcoma and that indicates that this cancer initially arises from tissue of embryonic mesenchymal origin the fertilized egg divides and redivides forming a sphere early in embryogenesis dimples appear in the poles of the sphere and burrow through the sphere forming an inner passage that will ultimately form the gut malignancies arising from cells that were originally part of the outer layer of the sphere and those that were part of the embryonic tunnel are termed carcinomas malignancies arising from the cells between the outer layer and the inner burrow are termed sarcomas typically asps arises in muscles and deep soft tissue of the thigh or the leg lower extremities but can also appear in the upper extremities hands neck and head while asps is a soft tissue sarcoma it can also spread and grow inside the bones the term alveolar comes from the microscopic pattern visible during the analysis of slides of asps under the microscope in histopathology the tumor cells seem to be arranged in the same pattern as the cells of the small air sacks alveoli in the lungs however this is just a structural similarity asps was first described and characterized in 1952
alzheimer s disease ad also known as just alzheimer s is a chronic neurodegenerative disease that usually starts slowly and gets worse over time it is the cause of 60 to 70 of cases of dementia the most common early symptom is difficulty in remembering recent events short term memory loss as the disease advances symptoms can include problems with language disorientation including easily getting lost mood swings loss of motivation not managing self care and behavioural issues as a person s condition declines they often withdraw from family and society gradually bodily functions are lost ultimately leading to death although the speed of progression can vary the average life expectancy following diagnosis is three to nine years the cause of alzheimer s disease is poorly understood about 70 of the risk is believed to be genetic with many genes usually involved other risk factors include a history of head injuries depression or hypertension the disease process is associated with plaques and tangles in the brain a probable diagnosis is based on the history of the illness and cognitive testing with medical imaging and blood tests to rule out other possible causes initial symptoms are often mistaken for normal ageing examination of brain tissue is needed for a definite diagnosis mental and physical exercise and avoiding obesity may decrease the risk of ad there are no medications or supplements that decrease risk no treatments stop or reverse its progression though some may temporarily improve symptoms affected people increasingly rely on others for assistance often placing a burden on the caregiver the pressures can include social psychological physical and economic elements exercise programmes are beneficial with respect to activities of daily living and can potentially improve outcomes treatment of behavioural problems or psychosis due to dementia with antipsychotics is common but not usually recommended due to there often being little benefit and an increased risk of early death in 2015 there were approximately 48 million people worldwide with ad it most often begins in people over 65 years of age although 4 to 5 of cases are early onset alzheimer s which begin before this it affects about 6 of people 65 years and older in 2010 dementia resulted in about 486 000 deaths it was first described by and later named after german psychiatrist and pathologist alois alzheimer in 1906 in developed countries ad is one of the most financially costly diseases
am fear liath mòr scottish gaelic pronunciation əm fɛɾ ʎiə moːɾ also known as the big grey man of ben macdhui or simply the greyman is the name of a presence or creature which is said to haunt the summit and passes of ben macdui the highest peak of the cairngorms and the second highest peak in scotland and also in the british isles
the amadori rearrangement is an organic reaction describing the acid or base catalyzed isomerization or rearrangement reaction of the n glycoside of an aldose or the glycosylamine to the corresponding 1 amino 1 deoxy ketose the reaction is important in carbohydrate chemistry the reaction mechanism is demonstrated starting from the reaction of d mannose in its closed 1 and open form 2 with ammonia to produce the 1 1 amino alcohol 3 which is unstable and loses water to the glycosylamine again the open imine 5 and the closed form hemiaminal 4 which is the starting point for the actual amadori rearrangement the amadori rearrangement by treatment of the glycosylamine with pyridine and acetic anhydride the imine group rearranges and the intermediate enol in turn rearranges to the ketone in this particular reaction all the alcohol and amino groups are acylated as well the reaction is associated with the maillard reaction in which the reagents are naturally occurring sugars and amino acids recent study is revealed the possibility of amadori rearrangement during interaction between oxidized dextran and gelatine
amalgam tattoo also termed localized argyrosis or focal argyrosis is a grey blue or black area of discoloration on the mucous membranes of the mouth typically on the gums of the lower jaw it is an iatrogenic lesion caused by entry of dental amalgam into the soft tissues it is common painless and benign but it can be mistaken for melanoma
amaurosis greek meaning darkening dark or obscure is vision loss or weakness that occurs without an apparent lesion affecting the eye it may result from either a medical condition or from excess acceleration as in flight the term is the same as the latin gutta serena
amaurosis fugax latin fugax meaning fleeting greek amaurosis meaning darkening dark or obscure is a painless transient monocular or binocular visual loss i e loss of vision in one or both eyes that is not permanent
amber shift is a phenomenon of incandescent lamps in which the perceived warmth or colour temperature of the light sources changes as larger amounts of electric current flow through it
the ambient pressure on an object is the pressure of the surrounding medium such as a gas or liquid which comes into contact with the object
ambiguous loss is a loss that occurs without closure or understanding this kind of loss leaves a person searching for answers and thus complicates and delays the process of grieving and often results in unresolved grief some examples are infertility termination of pregnancy disappearance of a family member death of an ex spouse a family member being physically alive but in a state of cognitive decline due to alzheimer s disease or dementia etc an ambiguous loss can be categorized into two types of loss physical or psychological physical loss and psychological loss differ in terms of what is being grieved for the loss of the physical body or the psychological mind experiencing an ambiguous loss can lead to personal questions such as am i still married to my missing spouse or am i still a child to a parent who no longer remembers me since the grief process in an ambiguous loss is halted it is harder to cope or move on to acceptance from the type of loss experienced there are various types of grief that can occur due to the type of ambiguity experienced and corresponding therapy techniques to address the certain types of grief the overall goal of therapy to cope with ambiguous loss is to overcome the trauma associated with it and restoring resilience
the ambitious card or elevator card is a magic effect in which a playing card seems to return to the top of the deck after being placed elsewhere in the middle of the deck this is a classic effect in card magic and serves as a study subject for students of magic most performing card magicians will have developed their own personal ambitious card routine the effect is often credited to french magician gustav alberti in the mid 19 th century however there is a related idea in ponsin s nouvelle magie blanche devoilée published in 1854 that might precede that
amblyopia also called lazy eye is a disorder of sight due to the eye and brain not working well together it results in decreased vision in an eye that otherwise typically appears normal it is the most common cause of decreased vision in a single eye among children and younger adults the cause of amblyopia can be any condition that interferes with focusing during early childhood this can occur from poor alignment of the eyes an eye being irregularly shaped such that focusing is difficult one eye being more nearsighted or farsighted than the other or clouding of the lens of an eye after the underlying cause is fixed vision is not fully restored as the mechanism also involves the brain amblyopia can be difficult to detect and therefore vision testing is recommended for all children around the ages of four to five early detection improves treatment success eye glasses may be all the treatment needed for some children if this is not sufficient treatments which force the child to use the weaker eye are used this is done by either using a patch or putting atropine in the stronger eye without treatment amblyopia typically persists into adulthood evidence regarding treatments for adults is poor amblyopia was first described in the 1600 s it begins by the age of five in adults the disorder is estimated to affect 1 – 5 of the population while treatment improves vision it does not typically restore it to normal in the affected eye the condition may make people ineligible to be pilots or police officers the word amblyopia is from greek meaning αμβλυωπία blunt vision
amebiasis cutis is a cutaneous condition characterized by ulcers caused by entamoeba histolytica
the ameboma may manifest as a right lower quadrant abdominal mass which may be mistaken for carcinoma tuberculosis crohn s disease actinomycosis or lymphoma
amelanism also known as amelanosis is a pigmentation abnormality characterized by the lack of pigments called melanins commonly associated with a genetic loss of tyrosinase function amelanism can affect fish amphibians reptiles birds and mammals including humans the appearance of an amelanistic animal depends on the remaining non melanin pigments the opposite of amelanism is melanism an overabundance of melanin a similar condition albinism is a hereditary condition characterised in animals by the absence of pigment in the eyes skin hair scales feathers or cuticle this results in an all white animal usually with pink or red eyes
amelanotic melanoma is a type of skin cancer in which the cells do not make melanin they can be pink red purple or of normal skin color hence difficult to recognise it has an asymmetrical shape and an irregular faintly pigmented border their atypical appearance leads to delay in diagnosis the prognosis is poor and the rate of recurrence is high
amelia from greek ἀ lack of plus μέλος plural μέλεα or μέλη limb is the birth defect of lacking one or more limbs it can also result in a shrunken or deformed limb for example a child might be born without an elbow or forearm the term may be modified to indicate the number of legs or arms missing at birth such as tetra amelia for the absence of all four limbs a related term is meromelia which is the partial absence of a limb or limbs
ameloblastic carcinoma is a rare form of odontogenic tumor one that develops in the jawbones from the epithelial cells that generate the tooth enamel symptoms include swelling in the jaw and pain both of which get worse as the cancer grows it is usually treated with surgery chemotherapy has not been proven to be effective
an ameloblastic fibroma is a fibroma of the ameloblastic tissue that is an odontogenic tumor arising from the enamel organ or dental lamina it may be either truly neoplastic or merely hamartomatous an odontoma in neoplastic cases it may be labeled an ameloblastic fibrosarcoma in accord with the terminological distinction that reserves the word fibroma for benign tumors and assigns the word fibrosarcoma to malignant ones it is more common in the first and second decades of life when odontogenesis is ongoing than in later decades in 50 of cases an unerupted tooth is involved histopathology alone is usually not enough to differentiate neoplastic cases from hamartomatous ones because the histology is very similar other clinical and radiographic clues are used to narrow the diagnosis
ameloblastoma from the early english word amel meaning enamel the greek word blastos meaning germ is a rare benign tumor of odontogenic epithelium ameloblasts or outside portion of the teeth during development much more commonly appearing in the lower jaw than the upper jaw it was recognized in 1827 by cusack this type of odontogenic neoplasm was designated as an adamantinoma in 1885 by the french physician louis charles malassez it was finally renamed to the modern name ameloblastoma in 1930 by ivey and churchill while these tumors are rarely malignant or metastatic that is they rarely spread to other parts of the body and progress slowly the resulting lesions can cause severe abnormalities of the face and jaw additionally because abnormal cell growth easily infiltrates and destroys surrounding bony tissues wide surgical excision is required to treat this disorder if an aggressive tumor is left untreated it can obstruct the nasal and oral airways making it impossible to breathe without oropharyngeal intervention
amelogenesis imperfecta ai presents with a rare abnormal formation of the enamel or external layer of the crown of teeth enamel is composed mostly of mineral that is formed and regulated by the proteins in it amelogenesis imperfecta is due to the malfunction of the proteins in the enamel ameloblastin enamelin tuftelin and amelogenin people afflicted with amelogenesis imperfecta have teeth with abnormal color yellow brown or grey this disorder can afflict any number of teeth of both dentitions the teeth have a higher risk for dental cavities and are hypersensitive to temperature changes as well as rapid attrition excessive calculus deposition and gingival hyperplasia
amenorrhoea be amenorrhea ame or amenorrhœa is the absence of a menstrual period in a woman of reproductive age physiological states of amenorrhoea are seen most commonly during pregnancy and lactation breastfeeding the latter also forming the basis of a form of contraception known as the lactational amenorrhoea method outside of the reproductive years there is absence of menses during childhood and after menopause amenorrhoea is a symptom with many potential causes primary amenorrhoea menstruation cycles never starting may be caused by developmental problems such as the congenital absence of the uterus failure of the ovary to receive or maintain egg cells also delay in pubertal development will lead to primary amenorrhoea it is defined as an absence of secondary sexual characteristics by age 14 with no menarche or normal secondary sexual characteristics but no menarche by 16 years of age secondary amenorrhoea menstruation cycles ceasing is often caused by hormonal disturbances from the hypothalamus and the pituitary gland from premature menopause or intrauterine scar formation it is defined as the absence of menses for three months in a woman with previously normal menstruation or nine months for women with a history of oligomenorrhoea
the american folk music revival was a phenomenon in the united states that began during the 1940 s and peaked in popularity in the mid 1960 s its roots went earlier and performers like josh white burl ives woody guthrie lead belly big bill broonzy richard dyer bennet oscar brand jean ritchie john jacob niles susan reed paul robeson and cisco houston had enjoyed a limited general popularity in the 1930 s and 1940 s the revival brought forward styles of american folk music that had in earlier times contributed to the development of country and western jazz and rock and roll music
american tick bite fever also known as rickettsia parkeri infection is a condition that may be characterized by a rash of maculopapules
ametropic amblyopia is a medical condition in which the retina cannot focus on the image of a distant object a condition often described as reduced visual acuity this is due to large uncorrected refractive errors in the patient s optic system of the eyes astigmatism is one of the most frequent causes of ametropic amblyopia
amide reduction is a reaction in organic synthesis where an amide is reduced to either an amine or an aldehyde functional group
amine alkylation amino de halogenation is a type of organic reaction between an alkyl halide and ammonia or an amine the reaction is called nucleophilic aliphatic substitution of the halide and the reaction product is a higher substituted amine the method is widely used in the laboratory but is less important industrially where alkyl halides are not preferred alkylating agents when the amine is a tertiary amine the reaction product is a quaternary ammonium salt in the menshutkin reaction amines and ammonia are generally sufficiently basic to undergo direct alkylation often under mild conditions the reactions are difficult to control because the reaction product a primary amine or a secondary amine are often more nucleophilic than the precursor and will thus preferentially react with the alkylating agent for example reaction of 1 bromooctane with ammonia yields almost equal amounts of the primary amine and the secondary amine therefore for laboratory purposes n alkylation is often limited to the synthesis of tertiary amines a notable exception is the reactivity of alpha halo carboxylic acids that do permit synthesis of primary amines with ammonia intramolecular reactions of haloamines x ch 2 n nh 2 give cyclic aziridines azetidines and pyrrolidines n alkylation is a general and useful route to quaternary ammonium salts from tertiary amines because overalkylation is not possible examples of n alkylation with alkyl halides are the syntheses of benzylaniline 1 benzylindole and azetidine another example is found in the derivatization of cyclen industrially ethylenediamine is produced by alkylation of ammonia with 1 2 dichloroethane
amino acid transport disorders are medical conditions associated with a failure of amino acids to be absorbed from the kidney or intestine an example is hartnup disease
aminoaciduria is the presence of amino acids in the urine small amounts of amino acids are also present in normal urine increased total urine amino acids may result from metabolic disorders chronic liver disease or renal disorders aminoacidurias can be divided into primary and secondary aminoacidurias
aminoacylase 1 deficiency is a rare inborn error of metabolism to date only 21 cases have been described
aminolevulinic acid dehydratase deficiency porphyria also known as doss porphyria and plumboporphyria is a neuropsychiatric condition disease can present during early childhood as well as in adulthood with acute neurologic symptoms that resemble those encountered in acute intermittent porphyria the condition is extremely rare with fewer than 10 cases ever reported ala dehydratase deficiency is a rare cause of hepatic porphyria it is an autosomal recessive disorder that results from inappropriately low levels of the enzyme ala dehydratase alad also called porphobilinogen synthase which is required for normal heme synthesis
amitosis a mitosis is cell proliferation that does not occur by mitosis the mechanism usually identified as essential for cell division in eukaryotes the polyploid macronucleus found in ciliates divides amitotically while normal mitosis results in a precise division of parental alleles amitosis results in a random distribution of parental alleles ploidy levels of 1000 in some species means both parental alleles can be maintained over many generations while species with fewer numbers of each chromosome will tend to become homozygous for one or the other parental allele through a process known as phenotypic or allelic assortment it does not involve maximal condensation of chromatin into chromosomes observable by light microscopy as they line up in pairs along the metaphase plate it does not involve these paired structures being pulled in opposite directions by a mitotic spindle to form daughter cells rather it effects nuclear proliferation without the involvement of chromosomes unsettling for cell biologists who have come to rely on the mitotic figure as reassurance that chromatin is being equally distributed into daughter cells the phenomenon of amitosis even though it is an accepted as occurring in ciliates continues to meet with skepticism about its role in mammalian cell proliferation perhaps because it lacks the reassuring iconography of mitosis of course the relatively recent discovery of copy number variations cnv s in mammalian cells within an organ significantly challenges the age old assumption that every cell in an organism must inherit an exact copy of the parental genome to be functional rather than cnv s resulting from mitosis gone awry some of this variation may arise from amitosis and may be both desirable and necessary furthermore it is well to remember that ciliates possess a mechanism for adjusting copy numbers of individual genes during amitosis of the macronucleus prescott 1994 despite the passage of more than a century since its description by walther flemming more celebrated for describing mitosis and others child 1907 macklin 1914 the process has not received much attention using mitosis in mammalian cells as a search term in the medline data base calls up more than 10 000 studies dealing with mitosis whereas amitosis in mammalian cells retrieves the titles of fewer than 50 papers not surprisingly this absence of data has led many scientists to conclude that amitosis does not exist or is minimally important if any means of proliferation can be deemed minimally important while the war on cancer is not yet won accordingly and despite being very much out of fashion a resurgence of interest in the role of amitosis in mammalian proliferation has been building over the past two to three decades a review of the resulting literature not only affirms the involvement of amitosis in cell proliferation it also explores the existence of more than one amitotic mechanism capable of producing progeny nuclei without the involvement of mitotic chromosomes one form of amitosis involves fissioning a nucleus splitting in two without the involvement of chromosomes and has been reported in placental tissue as well as in cells grown from that tissue in rats ferguson and palm 1976 in human trophoblasts cotte et al 1980 and in mouse trophoblasts kuhn therman and susman 1991 amitosis by fissioning has also been reported in mammalian liver cells david and uerlings 1992 and human adrenal cells magalhaes pignatelli and magalhaes 1991 chen and wan 1986 not only reported amitosis in rat liver but also presented a mechanism for a four stage amitotic process whereby chromatin threads are reproduced and equally distributed to daughter cells as the nucleus splits in two additional examples of non mitotic proliferation and important insights into underlying mechanisms have resulted from extensive work with polyploid cells such cells long acknowledged to exist were once believed simply to be anomalous accumulating research including in the liver duncan et al 2010 now suggests that cells containing multiple copies of the genome are importantly involved in a cell s ability to adapt to its environment a couple of decades of research has shown that polyploid cells are frequently reduced to diploid cells by amitosis zybina et al for instance naturally occurring polyploid placental cells have been shown capable of producing nuclei with diploid or near diploid complements of dna furthermore zybina and her colleagues have demonstrated that such nuclei derived from polyploid placental cells receive one or two copies of a microscopically identifiable region of the chromatin demonstrating that even without the reassuring iconography of identical chromosomes being distributed into identical daughter cells this particular amitotic process results in representative transmission of chromatin studying rat polyploid trophoblasts this research group has shown that the nuclear envelope of the giant nucleus is involved in this subdivision of a highly polyploid nucleus into low ploidy nuclei zybina and zybina polyploid cells are also at the heart of experiments to determine how some cells may survive chemotherapy erenpreisa and colleagues have shown that following treatment of cultured cells with mitosis inhibiting chemicals similar to what is used in some chemotherapy a small population of induced polyploid cells survives eventually this population can give rise to normal diploid cells by formation of polyploid chromatin bouquets that return to an interphase state and separate into several secondary nuclei erenpreisa et al 2011 intriguing phenomena including controlled autophagic degradation of some dna as well as production of nuclear envelope limited sheets accompanies the process erenpreisa et al 2002 since neither of these depolyploidizations involves mitotic chromosomes they conform to the broad definition of amitosis there are also multiple reports of amitosis occurring when nuclei bud out through the plasma membrane of a polyploid cell such a process has been shown to occur in amniotic cells transformed by a virus walen 2002 as well as in mouse embryo fibroblast lines exposed to carcinogens sundaram et al 2004 a similar process called extrusion has been described for mink trophoblasts a tissue in which fissioning is also observed isakova and shilaova 2002 asymmetric cell division has also been described in polyploid giant cancer cells and low eukaryotic cells and reported to occur by the amitotic processes of splitting budding or burst like mechanisms zhang wang and zhang 2012 similarly two different kinds of amitosis have been described in monolayers of ishikawa endometrial cells fleming 2014 an example of amitosis particularly suited to the formation of multiple differentiated nuclei in a reasonably short period of time has been shown to occur during the differentiation of fluid enclosing hemispheres called domes from adherent ishikawa endometrial monolayer cells during an approximately 20 hour period fleming 1995 fleming 1999 aggregates of nuclei from monolayer syncytia become enveloped in mitochondrial membranes forming structures mitonucleons that become elevated as a result of vacuole formation during the initial 6 hours of differentiation fleming 1998 fleming 2015 a over the next 4 or 5 hours chromatin from these aggregated nuclei becomes increasingly pycnotic eventually undergoing karyolysis and karyorrhexis in the now elevated predome structures fleming 2015 b in other systems such changes accompany apoptosis but not in the differentiating ishikawa cells where the processes appear to accompany changes in dna essential for the newly created differentiated dome cells finally the chromatin filaments emerging from these processes form a mass from which dozens of dome nuclei are amitotically generated fleming 2015 c over a period of approximately 3 hours with the apparent involvement of nuclear envelope limited sheets that all of this may be an iceberg tip is suggested by research from walter thilly s laboratory examination of fetal gut 5 to 7 weeks colonic adenomas and adenocarcinomas has revealed nuclei that look like hollow bells encased in tubular syncytia these structures can divide symmetrically by an amitotic nuclear fission process forming new bells or they can fission assymetrically resulting in one of seven other nuclear morphotypes five of which appear to be specific to development since they are rarely observed in adult organisms gostjeva et al 2006 the research that is accumulating about amitosis suggests that such processes are indeed involved in the production of the breathtaking 37 trillion or so cells in humans perhaps particularly during the fetal and embryonic phases of development when the majority of these cells are produced perhaps within the complexity of implantation perhaps when large numbers of cells are being differentiated and perhaps in cancerous cells a word of caution some examples of cell division formerly thought to belong to this non mitotic class such as the division of some unicellular eukaryotes may actually occur by the process of closed mitosis different from open or semi closed mitotic processes all involving mitotic chromosomes and classified by the fate of the nuclear envelope
ammonia poisoning is a common fish disease in new aquariums especially when immediately stocked to full capacity ideally the level of ammonia nh 3 and ammonium compounds i e those containing nh 4 should be zero although trace amounts are generally harmless they can still lead to problems over time understanding the nitrogen cycle is essential for the keeping of any aquatic life the amount of ammonia present is usually accompanied by a rise in ph as ammonia is a base it is stabilized by alkaline water it can cause damage to the gills at a level as small as 0 25 mg l
amnesia from greek meaning forgetfulness from ἀ a meaning without and μνήσις mnesis meaning memory also known as amnesic syndrome is a deficit in memory caused by brain damage disease or psychological trauma amnesia can also be caused temporarily by the use of various sedatives and hypnotic drugs the memory can be either wholly or partially lost due to the extent of damage that was caused there are two main types of amnesia retrograde amnesia and anterograde amnesia retrograde amnesia is the inability to retrieve information that was acquired before a particular date usually the date of an accident or operation in some cases the memory loss can extend back decades while in others the person may lose only a few months of memory anterograde amnesia is the inability to transfer new information from the short term store into the long term store people with this type of amnesia cannot remember things for long periods of time these two types are not mutually exclusive both can occur within a patient at one time case studies such as that of show that both types of amnesia can occur simultaneously case studies also show that amnesia is typically associated with damage to the medial temporal lobe in addition specific areas of the hippocampus the ca 1 region are involved with memory research has also shown that when areas of the diencephalon are damaged amnesia can occur recent studies have shown a correlation between deficiency of rbap 48 protein and memory loss scientists were able to find that mice with damaged memory have a lower level of rbap 48 protein compared to normal healthy mice in people suffering with amnesia the ability to recall immediate information is still retained and they may still be able to form new memories however a severe reduction in the ability to learn new material and retrieve old information can be observed patients can learn new procedural knowledge in addition priming both perceptual and conceptual can assist amnesiacs in the learning of fresh non declarative knowledge amnesic patients also retain substantial intellectual linguistic and social skill despite profound impairments in the ability to recall specific information encountered in prior learning episodes
amnesic shellfish poisoning asp is a human illness caused by consumption of the marine biotoxin called domoic acid this toxin is produced naturally by marine diatoms belonging to the genus pseudo nitzschia and the species nitzschia navis varingica when accumulated in high concentrations by shellfish during filter feeding domoic acid can then be passed on to humans via consumption of the contaminated shellfish although human illness due to domoic acid has only been associated with shellfish the toxin can bioaccumulate in many marine organisms that consume phytoplankton such as anchovies and sardines intoxication by domoic acid in non human organisms is frequently referred to as domoic acid poisoning or dap in mammals including humans domoic acid acts as a neurotoxin causing permanent short term memory loss brain damage and death in severe cases
amnion nodosum are nodules on the fetal surface of the amnion and is frequently present in oligohydramnios the nodules are composed of squamous cell aggregates derived from the vernix caseosa on the fetal skin amnion nodosum and oligohydromnios are associated with pulmonary hypoplasia and renal agenesis amnion nodosum is granules on amnion whereas whitish nodules on the cord suggest a candidial infection
amniotic band constriction also known as amniotic band syndrome adam complex amniotic band sequence congenital constriction bands and pseudoainhum is a congenital disorder caused by entrapment of fetal parts usually a limb or digits in fibrous amniotic bands while in utero
an amniotic fluid embolism afe is a rare childbirth obstetric emergency in which amniotic fluid fetal cells hair or other debris enters the mother s blood stream via the placental bed of the uterus and triggers an allergic like reaction this reaction then results in cardiorespiratory heart and lung collapse and massive hemorrhaging coagulopathy it was first formally characterized in 1941 while it is rare between 1 in 8 000 and 1 in 80 000 deliveries the high mortality makes it the fifth most common cause of maternal mortality in the world in some estimates
amodal perception is the perception of the whole of a physical structure when only parts of it affect the sensory receptors for example a table will be perceived as a complete volumetric structure even if only part of it — the facing surface — projects to the retina it is perceived as possessing internal volume and hidden rear surfaces despite the fact that only the near surfaces are exposed to view similarly the world around us is perceived as a surrounding plenum even though only part of it is in view at any time another much quoted example is that of the dog behind a picket fence in which a long narrow object the dog is partially occluded by fence posts in front of it but is nevertheless perceived as a single continuous object albert bregman noted an auditory analogue of this phenomenon when a melody is interrupted by bursts of white noise it is nonetheless heard as a single melody continuing behind the bursts of noise formulation of the theory is credited to the belgian psychologist albert michotte and fabio metelli an italian psychologist with their work developed in recent years by e s reed and the gestaltists modal completion is a similar phenomenon in which a shape is perceived to be occluding other shapes even when the shape itself is not drawn examples include the triangle that appears to be occluding three disks and an outlined triangle in the kanizsa triangle and the circles and squares that appear in different versions of the koffka cross
amoebiasis also known as amebiasis or entamoebiasis is an infection caused by any of the amoebas of the entamoeba group symptoms are most common upon infection by entamoeba histolytica amoebiasis can present with no mild or severe symptoms symptoms may include abdominal pain mild diarrhoea bloody diarrhea or severe colitis with tissue death and perforation this last complication may cause peritonitis people affected may develop anemia due to loss of blood invasion of the intestinal lining causes amoebic bloody diarrhea or amoebic colitis if the parasite reaches the bloodstream it can spread through the body most frequently ending up in the liver where it causes amoebic liver abscesses liver abscesses can occur without previous diarrhea cysts of entamoeba can survive for up to a month in soil or for up to 45 minutes under fingernails it is important to differentiate between amoebiasis and bacterial colitis the preferred diagnostic method is through faecal examination under microscope but requires a skilled microscopist and may not be reliable when excluding infection this method however may not be able to separate between specific types increased white blood cell count is present in severe cases but not in mild ones the most accurate test is for antibodies in the blood but it may remain positive following treatment prevention of amoebiasis is by separating food and water from faeces and by proper sanitation measures there is no vaccine there are two treatment options depending on the location of the infection amoebiasis in tissues is treated with either metronidazole tinidazole nitazoxanide dehydroemetine or chloroquine while luminal infection is treated with diloxanide furoate or iodoquinoline for treatment to be effective against all stages of the amoeba may require a combination of medications infections without symptoms do not require treatment but infected individuals can spread the parasite to others and treatment can be considered treatment of other entamoeba infections apart from e histolytica is not needed amoebiasis is present all over the world about 480 million people are infected with what appears to be e histolytica and these result in the death of between 40 000 – 110 000 people every year most infections are now ascribed to e dispar e dispar is more common in certain areas and symptomatic cases may be fewer than previously reported the first case of amoebiasis was documented in 1875 and in 1891 the disease was described in detail resulting in the terms amoebic dysentery and amoebic liver abscess further evidence from the philippines in 1913 found that upon ingesting cysts of e histolytica volunteers developed the disease it has been known since 1897 that at least one non disease causing species of entamoeba existed entamoeba coli but it was first formally recognized by the who in 1997 that e histolytica was two species despite this having first been proposed in 1925 in addition to the now recognized e dispar evidence shows there are at least two other species of entamoeba that look the same in humans e moshkovskii and entamoeba bangladeshi the reason these species haven t been differentiated until recently is because of the reliance on appearance
an amoebic brain abscess is a brain abscess caused by amoebas symptoms that accompany this abscess are collections of immune cells and large groupings of pus that gather in the brain this very rare case has only been reported and examined on 216 known occurrences dating back to 1849 diagnosis for this abscess entails numerous medical tests and studies it can be caused by entamoeba histolytica primary amoebic meningoencephalitis and granulomatous amoebic encephalitis can also invade the brain
amoebic dysentery or amebic dysentery is a type of bloody diarrhea caused primarily by the amoeba entamoeba histolytica amoebic dysentery is transmitted through contaminated food and water amoebae spread by forming infective cysts which can be found in stools and spread if whoever touches them does not sanitize their hands there are also free amoebae or trophozoites that do not form cysts however trophozoites do not survive long outside the human gastrointestinal tract and are a purely diagnostic observation trophozoites are the agent responsible for symptoms amoebic dysentery is most common in developing countries although it is occasionally seen in industrialized countries and not just in travellers although it is commonly associated with tropical climates the first documented case was in st petersburg russia amoebic dysentery is often confused with traveler s diarrhea because of the prevalence of both in developing nations in fact most traveller s diarrhea is bacterial or viral in origin liver infection and subsequent amoebic abscesses can occur blood may be present in stool it can be considered equivalent to intestinal amoebiasis
a amoebic liver abscess is a type of liver abscess caused by amebiasis it is the involvement of liver tissue by trophozoites of the organism entamoeba histolytica and of is abscess due to necrosis
amorality is an absence of indifference towards or disregard for morality morality and amorality in humans and animals is a subject of dispute among scientists and philosophers if morality is intrinsic to humanity then amoral human beings either do not exist or are only deficiently human if morality is extrinsic to humanity then amoral human beings can both exist and be fully human and may be amoral either by nature or by choice amoral should not be confused with immoral which refers to an agent doing or thinking something he or she knows or believes to be wrong
amorphosynthesis is a medical condition where the patient is unaware of somatic sensations from one side of the body the left side is most commonly affected this condition is usually a sign of a lesion in the right parietal lobe the patient also shows loss of proprioception and spatial relationships additionally when the somatosensory association area is damaged one loses the ability to recognize a complex object on the opposite side of the body
amotivational syndrome is a psychological condition associated with diminished inspiration to participate in social situations and activities with episodes of apathy caused by an external event situation substance or lack of relationship or lack of or other cause while some have claimed that chronic use of cannabis causes amotivational syndrome in some users empirical studies suggest that there is no such thing as amotivational syndrome per se from a world health organization report the evidence for an amotivational syndrome among adults consists largely of case histories and observational reports e g kolansky and moore 1971 millman and sbriglio 1986 the small number of controlled field and laboratory studies have not found compelling evidence for such a syndrome dornbush 1974 negrete 1983 hollister 1986 i t is doubtful that cannabis use produces a well defined amotivational syndrome it may be more parsimonious to regard the symptoms of impaired motivation as symptoms of chronic cannabis intoxication rather than inventing a new psychiatric syndrome a study done by researchers barnwell earleywine and wilcox also suggests that cannabis use does not cause an amotivational syndrome the e mail survey showed no significant difference in motivation as measured on the apathy evaluation scale between cannabis users and cannabis abstainers other research done by imperial college london has found that long term users of cannabis tend to produce less dopamine a chemical produced by the brain which plays an important role in executive functions motor control motivation arousal reinforcement and reward the research also suggests that users of cannabis which started at a younger age may produce even less dopamine than those that began using later in their life the cannabis users chosen for the study had all experienced psychotic like episodes while using the drug and were selected as such because previous research hypothesizes that positive symptoms of psychosis are linked to excess dopamine production however the researchers found that the opposite was the case in these long term cannabis users because dopamine plays a large role in motivation the research suggests that long term cannabis use may cause amotivational syndrome according to the handbook of clinical psychopharmacology for therapists amotivational syndrome is listed as a possible side effect of ssris in the treatment of clinical depression
amovibility is the condition that applies to roman catholic priests who can be removed from their parish or post by their bishop
amphetamine dependence refers to a state of psychological dependence on a drug in the amphetamine class in individuals with substance use disorder problematic use or abuse with dependence psychotherapy is currently the best treatment option as no pharmacological treatment has been approved tolerance is expected to develop with regular substituted amphetamine use when substituted amphetamines are abused drug tolerance develops rapidly severe withdrawal associated with dependence from recreational substituted amphetamine use can be a difficult for a user to cope with long term use of certain substituted amphetamines particularly methamphetamine can reduce dopamine activity in the brain psychostimulants that increase dopamine and mimic the effects of substituted amphetamines but with lower abuse liability could theoretically be used as replacement therapy in amphetamine dependence however the few studies that used amphetamine bupropion methylphenidate and modafinil as a replacement therapy did not result in less methamphetamine use or craving in 2013 overdose on amphetamine methamphetamine and other compounds implicated in an amphetamine use disorder resulted in an estimated 3 788 deaths worldwide 3 425 – 4 145 deaths 95 confidence
amphistomiasis or paramphistomiasis alternatively spelled amphistomosis or paramphistomosis is a parasitic disease of livestock animals more commonly of cattle and sheep and humans caused by immature helminthic flatworms belonging to the order echinostomida the term amphistomiasis is used for broader connotation implying the disease inflicted by members of echinostomida including the family paramphistomidae gastrodiscidae to be precise the species gastrodiscoides hominis whereas paramphistomiasis is restricted to that of the members of the family paramphistomatidae only g discoides and watsonius watsoni are responsible for the disease in humans while most paramphistomes are responsible in livestock animals and some wild mammals in livestock industry the disease causes heavy economic backlashes due to poor production of milk meat and wool
amplified musculoskeletal pain syndromes are pain syndromes where excessive acute and chronic pain are observed for which no overt primary cause can be found or surmised amplified musculoskeletal pain syndromes include complex regional pain syndrome types i ii formerly known as reflex sympathetic dystrophy rsd fibromyalgia diffuse idiopathic pain also called diffuse amplified pain localized idiopathic pain also called localized amplified pain neuropathic pain reflex neurovascular dystrophy
the amplitude of accommodation is the maximum potential increase in optical power that an eye can achieve in adjusting its focus it refers to a certain range of object distances for which the retinal image is as sharply focussed as possible amplitude of accommodation is measured during routine eye examination the closest that a normal eye can focus is typically about 10 cm for a child or young adult accommodation then decreases gradually with age effectively finishing just after age fifty the average amplitude of accommodation in diopters for a patient of a given age was estimated by hofstetter in 1950 to be 18 5 0 30 patient age in years with the minimum amplitude of accommodation as 15 0 25 age in years and the maximum as 25 0 40 age in years however hofstetter s work was based on data from two early surveys which although widely cited used methodology with considerable inherent error
the ampulla of ductus deferens is an enlargement of the ductus deferens at the fundus of the bladder this structure is seen in some mammalian and squamate species and is sometimes tortuous in shape
amputation is the removal of a limb by trauma medical illness or surgery as a surgical measure it is used to control pain or a disease process in the affected limb such as malignancy or gangrene in some cases it is carried out on individuals as a preventative surgery for such problems a special case is that of congenital amputation a congenital disorder where fetal limbs have been cut off by constrictive bands in some countries amputation of the hands feet or other body parts is or was used as a form of punishment for people who committed crimes amputation has also been used as a tactic in war and acts of terrorism it may also occur as a war injury in some cultures and religions minor amputations or mutilations are considered a ritual accomplishment unlike some non mammalian animals such as lizards that shed their tails salamanders that can regrow many missing body parts and hydras flatworms and starfish that can regrow entire bodies from small fragments once removed human extremities do not grow back unlike portions of some organs such as the liver a transplant or a prosthesis are the only options for recovering the loss in the us the majority of new amputations occur due to complications of the vascular system the blood vessels especially from diabetes between 1988 and 1996 there were an average of 133 735 hospital discharges for amputation per year in the us
amsler sign also known as amsler verrey sign is the name of the diagnostic finding seen in patients with fuchs heterochromic iridocyclitis fhi it is described as presence of blood hyphema in the aspirated vitreous fluid in paracentesis of the anterior chamber and is caused due to iris atrophy usually seen in fhi and exposure of the fragile iris vasculature to the vitreous fluid the sudden change of pressure in the anterior chamber upon suction induced by the paracentesis or during a cataract surgery causes bursting of the fragile superficial iris capillaries resultsing in micro bleeding this is one clinical diagnostic sign of fhi
studies have shown that congenital amusia is a deficit in fine grained pitch discrimination and that 4 of the population suffers from this disorder acquired amusia on the other hand may take several forms patients with brain damage may experience the loss of ability to produce musical sounds while sparing speech much like aphasics lose speech selectively but can sometimes still sing other forms of amusia may affect specific sub processes of music processing current research has demonstrated dissociations between rhythm melody and emotional processing of music and amusia may include impairment of any combination of these skill sets
amyloid cardiomyopathy is heart muscle damage caused by amyloidosis e g familial amyloid cardiomyopathy fac or ttr amyloid cardiomyopathy attr cm
amyloid purpura is a condition marked by bleeding under the skin purpura in some individuals with amyloidosis its cause is unknown but coagulation defects caused by amyloid are thought to contribute
amyloidosis is a rare and serious disease caused by accumulation of proteins in the form of abnormal insoluble fibres known as amyloid fibrils within the extracellular space in the tissues of the body amyloid deposits can be confined to only one part of the body or a single organ system in local amyloidosis or they can be widely distributed in organs and tissues throughout the body in systemic amyloidosis the symptoms of amyloidosis are accordingly highly variable and confirmation of the presence of amyloid in the tissues can be challenging so that diagnosis is often delayed amyloid fibrils are formed by aggregation clumping of normally soluble body proteins and accumulate progressively forming amyloid deposits which disrupt the normal tissue architecture damaging the function of tissues and organs and causing disease in contrast to the normally efficient clearance of abnormal debris from the tissues amyloid deposits are removed very slowly if at all there are many different types of amyloidosis each caused by formation of amyloid fibrils from different soluble precursor proteins in different patients about 30 different proteins are known to form amyloid fibrils in humans and amyloidosis is named and classified according to the identity of the respective fibril protein
amylophagia is a condition involving the compulsive consumption of excessive amounts of purified starch it is a form of pica and is often observed in pregnant women
amyoplasia is a condition characterized by a generalized lack in the newborn of muscular development and growth with contracture and deformity at most joints it is the most common form of arthrogryposis it is characterized by the four limbs being involved and by the replacement of skeletal muscle by dense fibrous and adipose tissue studies involving amyoplasia have revealed similar findings of the muscle tissue due to various causes including that seen in sacral agenesis and amyotropic lateral sclerosis so amyoplasia may also include an intermediate common pathway rather than the primary cause of the contractors
amyotrophic lateral sclerosis als also known as lou gehrig s disease and motor neurone disease mnd is a specific disease that causes the death of neurons which control voluntary muscles some also use the term motor neuron disease for a group of conditions of which als is the most common als is characterized by stiff muscles muscle twitching and gradually worsening weakness due to muscles decreasing in size this results in difficulty in speaking swallowing and eventually breathing the cause is not known in 90 to 95 of cases about 5 – 10 of cases are inherited from a person s parents about half of these genetic cases are due to one of two specific genes the diagnosis is based on a person s signs and symptoms with testing done to rule out other potential causes no cure for als is known a medication called riluzole may extend life by about two to three months non invasive ventilation may result in both improved quality and length of life the disease usually starts around the age of 60 and in inherited cases around the age of 50 the average survival from onset to death is two to four years about 10 survive longer than 10 years most die from respiratory failure in much of the world rates of als are unknown in europe and the united states the disease affects about two people per 100 000 per year descriptions of the disease date back to at least 1824 by charles bell in 1869 the connection between the symptoms and the underlying neurological problems was first described by jean martin charcot who in 1874 began using the term amyotrophic lateral sclerosis it became well known in the united states in the 20 th century when in 1939 it affected the baseball player lou gehrig and later worldwide when physicist stephen hawking diagnosed in 1963 and expected to die within two years became famous in 2014 videos of the ice bucket challenge went viral on the internet and increased public awareness
amyotrophy is progressive wasting of muscle tissues muscle pain is also a symptom it can occur in middle aged males with type 2 diabetes it also occurs with motor neuron disease
an injury to one is an injury to all is a motto popularly used by the industrial workers of the world in his autobiography bill haywood credited david c coates with suggesting a labor slogan for the iww an injury to one is an injury to all the slogan has since been used by a number of labor organizations the slogan reflects the fact that the iww is one big union and organizes skilled and unskilled workers despite the reduced number of organized workers today the slogan is still popular with labor unions and other organizations
an anacoluthon ænəkəˈluːθɒn an ə kə loo thon from the greek anakolouthon from an not and ἀκόλουθος akólouthos following is an unexpected discontinuity in the expression of ideas within a sentence leading to a form of words in which there is logical incoherence of thought anacolutha are often sentences interrupted midway where there is a change in the syntactical structure of the sentence and of intended meaning following the interruption an example is the italian proverb the good stuff – think about it this proverb urges people to make the best choice when anacoluthon occurs unintentionally it is considered to be an error in sentence structure and results in incoherent nonsense however it can be used as a rhetorical technique to challenge the reader to think more deeply or in stream of consciousness literature to represent the disjointed nature of associative thought anacoluthon is very common in informal speech where a speaker might start to say one thing then break off and abruptly and incoherently continue expressing a completely different line of thought when such speech is reported in writing a dash — is often included at the point of discontinuity the listener is expected to ignore the first part of the sentence although in some cases it might contribute to the overall meaning in an impressionistic sense
anagen effluvium is the pathologic loss of anagen or growth phase hairs classically it is caused by radiation therapy to the head and systemic chemotherapy especially with alkylating agents
anal cancer is a cancer malignant tumor which arises from the anus the distal opening of the gastrointestinal tract it is a distinct entity from the more common colorectal cancer anal cancer is typically an anal squamous cell carcinoma that arises near the squamocolumnar junction often linked to human papillomavirus hpv infection it may be keratinizing basaloid or non keratinizing cloacogenic other types of anal cancer are adenocarcinoma lymphoma sarcoma or melanoma from data collected 2004 2010 the relative five year survival rate in the united states is 65 5 though individual rates may vary depending upon the stage of cancer at diagnosis and the response to treatment
anal dysplasia is a pre cancerous condition which occurs when the lining of the anal canal undergoes abnormal changes it can be classified as low grade squamous intraepithelial lesions lsil and high grade squamous intraepithelial lesions hsil most cases are not associated with symptoms but people may notice lumps in and around the anus broken link
an anal fissure or rectal fissure is a break or tear in the skin of the anal canal anal fissures may be noticed by bright red anal bleeding on toilet paper sometimes in the toilet if acute they may cause pain after defecation but with chronic fissures pain intensity is often less anal fissures usually extend from the anal opening and are usually located posteriorly in the midline probably because of the relatively unsupported nature and poor perfusion of the anal wall in that location fissure depth may be superficial or sometimes down to the underlying sphincter muscle
anal fistula plural fistulae or fistula in ano is a chronic abnormal communication between the epithelialised surface of the anal canal and usually the perianal skin an anal fistula can be described as a narrow tunnel with its internal opening in the anal canal and its external opening in the skin near the anus anal fistulae commonly occur in people with a history of anal abscesses they can form when anal abscesses do not heal properly anal fistulae originate from the anal glands which are located between the internal and external anal sphincter and drain into the anal canal if the outlet of these glands becomes blocked an abscess can form which can eventually extend to the skin surface the tract formed by this process is a fistula abscesses can recur if the fistula seals over allowing the accumulation of pus it can then extends to the surface again repeating the process anal fistulae per se do not generally harm but can be very painful and can be irritating because of the drainage of pus it is also possible for formed stools to be passed through the fistula additionally recurrent abscesses may lead to significant short term morbidity from pain and importantly create a starting point for systemic infection treatment in the form of surgery is considered essential to allow drainage and prevent infection repair of the fistula itself is considered an elective procedure which many patients opt for due to the discomfort and inconvenience associated with an actively draining fistula
an anal sac adenocarcinoma is an uncommon and aggressive malignant tumor found in dogs that arises from the apocrine glandular tissue of anal sac the disease exists in cats as well but is much less common in that species they are the second most common cancerous cause of hypercalcaemia high serum calcium in dogs following t cell lymphoma
anal stricture or anal stenosis is a narrowing of the anal canal it can be cause by a number of surgical procedures including hemorrhoid removal and following anorectal wart treatment
analgesic nephropathy is injury to the kidney caused by analgesic medications such as aspirin phenacetin and paracetamol the term usually refers to damage induced by excessive use of combinations of these medications especially combinations that include phenacetin it may also be used to describe kidney injury from any single analgesic medication the specific kidney injuries induced by analgesics are renal papillary necrosis and chronic interstitial nephritis they appear to result from decreased blood flow to the kidney rapid consumption of antioxidants and subsequent oxidative damage to the kidney this kidney damage may lead to progressive chronic kidney failure abnormal urinalysis results high blood pressure and anemia a small proportion of individuals with analgesic nephropathy may develop end stage kidney disease analgesic nephropathy was once a common cause of kidney injury and end stage kidney disease in parts of europe australia and the united states in most areas its incidence has declined sharply since the use of phenacetin fell in the 1970 s and 1980 s
in mathematics an analytic function is a function that is locally given by a convergent power series there exist both real analytic functions and complex analytic functions categories that are similar in some ways but different in others functions of each type are infinitely differentiable but complex analytic functions exhibit properties that do not hold generally for real analytic functions a function is analytic if and only if its taylor series about x 0 converges to the function in some neighborhood for every x 0 in its domain
in mathematics and signal processing an analytic signal is a complex valued function that has no negative frequency components the real and imaginary parts of an analytic signal are real valued functions related to each other by the hilbert transform the analytic representation of a real valued function is an analytic signal comprising the original function and its hilbert transform this representation facilitates many mathematical manipulations the basic idea is that the negative frequency components of the fourier transform or spectrum of a real valued function are superfluous due to the hermitian symmetry of such a spectrum these negative frequency components can be discarded with no loss of information provided one is willing to deal with a complex valued function instead that makes certain attributes of the function more accessible and facilitates the derivation of modulation and demodulation techniques such as single sideband as long as the manipulated function has no negative frequency components that is it is still analytic the conversion from complex back to real is just a matter of discarding the imaginary part the analytic representation is a generalization of the phasor concept while the phasor is restricted to time invariant amplitude phase and frequency the analytic signal allows for time variable parameters
analytical skill is the ability to visualize articulate conceptualize or solve both complex and uncomplicated problems by making decisions that are sensible given the available information such skills include demonstration of the ability to apply logical thinking to breaking complex problems into their component parts in 1999 richards j heuer jr explained that thinking analytically is a skill like carpentry or driving a car it can be taught it can be learned and it can improve with practice but like many other skills such as riding a bike it is not learned by sitting in a classroom and being told how to do it analysts learn by doing to test for analytical skills one might be asked to look for inconsistencies in an advertisement put a series of events in the proper order or critically read an essay usually standardized tests and interviews include an analytical section that requires the examiner to use their logic to pick apart a problem and come up with a solution although there is no question that analytical skills are essential other skills are equally required for instance in systems analysis the systems analyst should focus on four sets of analytical skills systems thinking organizational knowledge problem identification and problem analyzing and solving
aṇaṅku is a phenomenon of sacred power described in ancient tamil literature such as the sangam literature
anaphia also known as tactile anesthesia is a medical symptom in which there is a total or partial absence of the sense of touch anaphia is a common symptom of spinal cord injury and neuropathy
anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death it typically causes more than one of the following an itchy rash throat or tongue swelling shortness of breath vomiting lightheadedness and low blood pressure these symptoms typically come on over minutes to hours common causes include insect bites and stings foods and medications other causes include latex exposure and exercise additionally cases may occur without an obvious reason the mechanism involves the release of mediators from certain types of white blood cells triggered by either immunologic or non immunologic mechanisms diagnosis is based on the presenting symptoms and signs after exposure to a potential allergen the primary treatment of anaphylaxis is epinephrine injection into a muscle intravenous fluids and positioning the person flat additional doses of epinephrine may be required other measures such as antihistamines and steroids are complementary carrying an epinephrine autoinjector and identification regarding the condition is recommended in people with a history of anaphylaxis worldwide 0 05 – 2 of the population is estimated to experience anaphylaxis at some point in life rates appear to be increasing it occurs most often in young people and females of people who go to a hospital with anaphylaxis in the united states about 0 3 die the term comes from the ancient greek ἀνά ana against and the ancient greek φύλαξις phylaxis protection
anaplasia from ancient greek ἀνά ana backward πλάσις plasis formation is a condition of cells in which they have poor cellular differentiation losing the morphological characteristics of mature cells and their orientation with respect to each other and to endothelial cells the term also refers to a group of morphological changes in a cell nuclear pleomorphism altered nuclear cytoplasmic ratio presence of nucleoli high proliferation index that point to a possible malignant transformation loss of structural differentiation especially as seen in most but not all malignant neoplasms sometimes the term also includes an increased capacity for multiplication lack of differentiation is considered a hallmark of aggressive malignancies for example it differentiates leiomyosarcomas from leiomyomas the term anaplasia literally means to form backward it implies dedifferentiation or loss of structural and functional differentiation of normal cells it is now known however that at least some cancers arise from stem cells in tissues in these tumors failure of differentiation rather than dedifferentiation of specialized cells account for undifferentiated tumors anaplastic cells display marked pleomorphism the nuclei are characteristically extremely hyperchromatic darkly stained and large the nuclear cytoplasmic ratio may approach 1 1 instead of the normal 1 4 or 1 6 giant cells that are considerably larger than their neighbors may be formed and possess either one enormous nucleus or several nuclei syncytia anaplastic nuclei are variable and bizarre in size and shape the chromatin is coarse and clumped and nucleoli may be of astounding size more important mitoses are often numerous and distinctly atypical anarchic multiple spindles may be seen and sometimes appear as tripolar or quadripolar forms also anaplastic cells usually fail to develop recognizable patterns of orientation to one another i e they lose normal polarity they may grow in sheets with total loss of communal structures such as gland formation or stratified squamous architecture anaplasia is the most extreme disturbance in cell growth encountered in the spectrum of cellular proliferations
anaplasmosis is a disease caused by a rickettsial parasite of ruminants anaplasma spp the microorganism is gram negative and occurs in the red blood cells it is transmitted by natural means through a number of haematophagous species of ticks anaplasmosis can also be transmitted by the use of surgical dehorning castration and tattoo instruments and hypodermic needles that are not disinfected between uses although the term is often associated with animal infection it is also used to describe infection in humans
anaplastic astrocytoma is a rare who grade iii type of astrocytoma which is a type of cancer of the brain in the united states the annual incidence rate for anaplastic astrocytoma is 0 44 per 100 000 persons
anaplastic large cell lymphoma alcl is a type of non hodgkin lymphoma involving aberrant t cells it is described in detail in the classification of tumors of the hematopoietic and lymphoid tissues edited by experts of the world health organisation who the term anaplastic large cell lymphoma alcl encompasses at least 4 different clinical entities all sharing the same name and histologically have also in common the presence of large pleomorphic cells that express cd 30 and t cell markers two types of alcl present as systemic disease and are considered as aggressive lymphomas while two types present as localized disease and may progress locally its name derives from anaplasia and large cell lymphoma
anaplastic thyroid cancer atc is a form of thyroid cancer which has a very poor prognosis due to its aggressive behavior and resistance to cancer treatments its anaplastic cells have poor differentiation including dedifferentiation
anaplerotic reactions from the greek ἀνά up and πληρόω to fill are chemical reactions that form intermediates of a metabolic pathway examples of such are found in the citric acid cycle tca cycle in normal function of this cycle for respiration concentrations of tca intermediates remain constant however many biosynthetic reactions also use these molecules as a substrate anaplerosis is the act of replenishing tca cycle intermediates that have been extracted for biosynthesis in what are called cataplerotic reactions the tca cycle is a hub of metabolism with central importance in both energy production and biosynthesis therefore it is crucial for the cell to regulate concentrations of tca cycle metabolites in the mitochondria anaplerotic flux must balance cataplerotic flux in order to retain homeostasis of cellular metabolism
anarchy is the condition of a society entity group of people or a single person that rejects hierarchy the term originally meant leaderlessness but in 1840 pierre joseph proudhon adopted the term in his treatise what is property to refer to a new political philosophy anarchism which advocates stateless societies based on voluntary associations in practical terms anarchy can refer to the curtailment or abolition of traditional forms of government
anasarca or extreme generalized edema is a medical condition characterized by widespread swelling of the skin due to effusion of fluid into the extracellular space it is usually caused by liver failure cirrhosis of the liver renal failure disease right sided heart failure as well as severe malnutrition protein deficiency the increase in salt and water retention caused by low cardiac output can also result in anasarca as a long term maladaptive response it can also be created from the administration of exogenous intravenous fluid certain plant derived anticancer chemotherapeutic agents such as docetaxel cause anasarca through a poorly understood capillary leak syndrome in hb barts the high oxygen affinity results in poor oxygen delivery to peripheral tissues resulting in anasarca
anatolia from greek ἀνατολή anatolḗ — east or sun rise in modern turkish anadolu in geography known as asia minor from greek μικρὰ ἀσία mīkrá asía — small asia in modern turkish küçük asya asian turkey anatolian peninsula or anatolian plateau is the westernmost protrusion of asia which makes up the majority of modern day turkey the region is bounded by the black sea to the north the mediterranean sea to the south and the aegean sea to the west the sea of marmara forms a connection between the black and aegean seas through the bosphorus and dardanelles straits and separates anatolia from thrace on the european mainland according to the traditional definition the eastern boundary of the anatolian peninsula is a diagonal line that extends from the gulf of alexandretta on the mediterranean coast of turkey to the shores of artvin province on the eastern black sea coast of the country the mountainous plateau to the east of this line was historically known as the armenian highlands armenia major this region is now named and largely situated within the eastern anatolia region in the far east of turkey and converges with the lesser caucasus — an area that was incorporated in the russian empire region of transcaucasia in the 19 th century thus traditionally anatolia is the territory that comprises approximately the western two thirds of the asian part of turkey since the early 20 th century anatolia is often considered to be synonymous with asian turkey which comprises more than 95 of the country s total land area and its eastern and southeastern borders are widely perceived as turkey s borders with neighboring georgia armenia azerbaijan iran iraq and syria in clockwise direction the ancient inhabitants of anatolia spoke the now extinct anatolian languages which were largely replaced by the greek language starting from classical antiquity and during the hellenistic roman and byzantine periods the turkification of anatolia began under the seljuk empire in the late 11 th century and continued under the ottoman empire between the early 14 th and early 20 th centuries however various non turkic languages continue to be spoken by minorities in anatolia today including kurdish assyrian armenian arabic laz georgian and greek
in entomology anautogeny is a reproductive strategy in which an adult female insect must eat a particular sort of meal generally vertebrate blood before laying eggs in order for her eggs to mature this behavior is most common among dipteran insects such as mosquitoes anautogenous animals often serve as vectors for infectious disease in their hosts because of their contact with hosts blood the opposite trait needing no special food as an adult to successfully reproduce is known as autogeny
ancylostomiasis also anchylostomiasis or ankylostomiasis is a hookworm disease caused by infection with ancylostoma hookworms the name is derived from greek ancylos αγκύλος crooked bent and stoma στόμα mouth ancylostomiasis is also known as miner s anaemia tunnel disease brickmaker s anaemia and egyptian chlorosis helminthiasis may also refer to ancylostomiasis but this term also refers to all other parasitic worm diseases as well in the united kingdom if acquired in the context of working in a mine the condition is eligible for industrial injuries disability benefit it is a prescribed disease b 4 under the relevant legislation § ancylostomiasis is caused when hookworms present in large numbers produce an iron deficiency anemia by sucking blood from the host s intestinal walls
andersen – tawil syndrome also called andersen syndrome and long qt syndrome 7 is a form of long qt syndrome it is a rare genetic disorder and is inherited in an autosomal dominant pattern and predisposes patients to cardiac arrhythmias jervell and lange nielsen syndrome is a similar disorder which is also associated with sensorineural hearing loss
in condensed matter physics anderson localization also known as strong localization is the absence of diffusion of waves in a disordered medium this phenomenon is named after the american physicist p w anderson who was the first one to suggest the possibility of electron localization inside a semiconductor provided that the degree of randomness of the impurities or defects is sufficiently large anderson localization is a general wave phenomenon that applies to the transport of electromagnetic waves acoustic waves quantum waves spin waves etc this phenomenon is to be distinguished from weak localization which is the precursor effect of anderson localization see below and from mott localization named after sir nevill mott where the transition from metallic to insulating behaviour is not due to disorder but to a strong mutual coulomb repulsion of electrons
an androgen dependent condition disease disorder or syndrome is a medical condition that is in part or full dependent on or is sensitive to the presence of androgenic activity in the body known androgen dependent conditions include acne seborrhea androgenic alopecia hirsutism hidradenitis suppurativa precocious puberty in boys hypersexuality paraphilias benign prostatic hyperplasia bph prostate cancer and hyperandrogenism in women such as in polycystic ovary syndrome pcos such conditions may be treated with drugs with antiandrogen actions including androgen receptor antagonists such as cyproterone acetate spironolactone and bicalutamide 5 α reductase inhibitors such as finasteride and dutasteride cyp 17 a 1 inhibitors such as abiraterone acetate gonadotropin releasing hormone gnrh analogues such as leuprolide and cetrorelix and or other antigonadotropins such as megestrol acetate and medroxyprogesterone acetate
androgen induced hermaphroditism is a syndrome resulting from a hermaphroditic birth defect of the genital organs they are induced in the 46 xx gonadally female fetus this occurs when there is too much masculinizing hormone transmitted through the placenta the external genitalia are that of a male if there is an excess of androgens in a male fetus it will give rise to infant hercules syndrome
androgen deficiency also known as hypoandrogenism and androgen deficiency syndrome is a medical condition characterized by not enough androgenic activity in the body
androgen insensitivity syndrome ais is a condition that results in the partial or complete inability of the cell to respond to androgens the unresponsiveness of the cell to the presence of androgenic hormones can impair or prevent the masculinization of male genitalia in the developing fetus as well as the development of male secondary sexual characteristics at puberty but does not significantly impair female genital or sexual development as such the insensitivity to androgens is clinically significant only when it occurs in genetic males i e individuals with a y chromosome or more specifically an sry gene clinical phenotypes in these individuals range from a normal male habitus with mild spermatogenic defect or reduced secondary terminal hair to a full female habitus despite the presence of a y chromosome ais is divided into three categories that are differentiated by the degree of genital masculinization complete androgen insensitivity syndrome cais is indicated when the external genitalia are that of a normal female mild androgen insensitivity syndrome mais is indicated when the external genitalia are that of a normal male and partial androgen insensitivity syndrome pais is indicated when the external genitalia are partially but not fully masculinized androgen insensitivity syndrome is the largest single entity that leads to 46 xy undermasculinized genitalia
the andronov – pontryagin criterion is a necessary and sufficient condition for the stability of dynamical systems in the plane it was derived by aleksandr andronov and lev pontryagin in 1937
androphobia is is an abnormal fear of men a type of specific social phobia the word is from ancient greek ἀνήρ anēr genitive ἀνδρός andros man and φόβος phóbos fear in he past the word androphobia also has been used to refer to fear of crowds of people or mankind androphobia was also used in reference of a distress for a woman who was made uncomfortable at the sight of men from hearing their voices or knowing they are in the house
in mathematics the andré – oort conjecture is an open problem in number theory that generalises the manin – mumford conjecture a prototypical version of the conjecture was stated by yves andré in 1989 and a more general version was conjectured by frans oort in 1995 the modern version is a natural generalisation of these two conjectures
anelli also known as anelletti are small thin rings of pasta they are generally used for soups and pasta salads a smaller version of anelli is anellini which is about one quarter of the size anelli pasta is used in the production of campbell s franco american spaghetti o s
an anembryonic gestation also known as a blighted ovum is a pregnancy in which the very early pregnancy appears normal on an ultrasound scan but as the pregnancy progresses a visible embryo never develops or develops and is reabsorbed in a normal pregnancy an embryo would be visible on an ultrasound by six weeks after the woman s last menstrual period an anembryonic gestation is characterized by a normal appearing gestational sac but the absence of an embryo it likely occurs as a result of early embryonic death with continued development of the trophoblast when small the sac cannot be distinguished from the early normal pregnancy as there may be a yolk sac though a fetal pole is not seen for diagnosis the sac must be of sufficient size that the absence of normal embryonic elements is established the criteria depends on the type of ultrasound exam performed a pregnancy is anembryonic if a transvaginal ultrasound reveals a sac with a mean gestational sac diameter mgd greater than 25 mm and no yolk sac or an mgd 25 mm with no embryo transabdominal imaging without transvaginal scanning may be sufficient for diagnosing early pregnancy failure whenan embryo whose crown – rump length is 15 mm or more has no visible cardiac activity rather than do a transvaginal exam at the time of the initial visit many centers prefer to do only a transabdominal study and offer mothers a follow up ultrasound 10 days later to see if a normal pregnancy subsequently develops anembryonic gestation is one of the causes of miscarriage of a pregnancy several management options exist for anembryonic pregnancies that have not miscarried on their own
anemia also spelled anaemia is usually defined as a decrease in the amount of red blood cells rbcs or hemoglobin in the blood it can also be defined as a lowered ability of the blood to carry oxygen when anemia comes on slowly the symptoms are often vague and may include feeling tired weakness shortness of breath or a poor ability to exercise anemia that comes on quickly often has greater symptoms which may include confusion feeling like one is going to pass out loss of consciousness or increased thirst anemia must be significant before a person becomes noticeably pale additional symptoms may occur depending on the underlying cause there are three main types of anemia that due to blood loss that due to decreased red blood cell production and that due to increased red blood cell breakdown causes of blood loss include trauma and gastrointestinal bleeding among others causes of decreased production include iron deficiency a lack of vitamin b 12 thalassemia and a number of neoplasms of the bone marrow causes of increased breakdown include a number of genetic conditions such as sickle cell anemia infections like malaria and certain autoimmune diseases it can also be classified based on the size of red blood cells and amount of hemoglobin in each cell if the cells are small it is microcytic anemia if they are large it is macrocytic anemia while if they are normal sized it is normocytic anemia diagnosis in men is based on a hemoglobin of less than 130 to 140 g l 13 to 14 g dl while in women it must be less than 120 to 130 g l 12 to 13 g dl further testing is then required to determine the cause certain groups of individuals such as pregnant women benefit from the use of iron pills for prevention dietary supplementation without determining the specific cause is not recommended the use of blood transfusions is typically based on a person s signs and symptoms in those without symptoms they are not recommended unless hemoglobin levels are less than 60 to 80 g l 6 to 8 g dl these recommendations may also apply to some people with acute bleeding erythropoiesis stimulating medications are only recommended in those with severe anemia anemia is the most common disorder of the blood affecting about a quarter of the people globally iron deficiency anemia affects nearly 1 billion in 2013 anemia due to iron deficiency resulted in about 183 000 deaths – down from 213 000 deaths in 1990 it is more common in females than males among children during pregnancy and in the elderly anemia increases costs of medical care and lowers a person s productivity through a decreased ability to work the name is derived from ancient greek ἀναιμία anaimia meaning lack of blood from ἀν an not αἷμα haima blood
anemia of chronic disease or anemia of chronic inflammation is a form of anemia seen in chronic infection chronic immune activation and malignancy these conditions all produce massive elevation of interleukin 6 which stimulates hepcidin production and release from the liver which in turn reduces the iron carrier protein ferroportin so that access of iron to the circulation is reduced other mechanisms may also play a role such as reduced erythropoiesis anemia of chronic inflammation is the preferred term since not all chronic diseases are associated with this form of anemia
anemia of prematurity refers to a form of anemia affecting preterm infants with decreased hematocrit
anemic infarcts also called white infarcts or pale infarcts are white or pale infarcts caused by arterial occlusions and are usually seen in the heart kidney and spleen these are referred to as white because of the lack of hemorrhaging and limited red blood cells accumulation compare to hemorrhagic infarct the tissues most likely to be affected are solid organs which limit the amount of hemorrhage that can seep into the area of ischemic necrosis from adjoining capillary beds the organs typically include single blood supply no dual arterial blood supply or anastomoses the infarct generally results grossly in a wedge shaped area of necrosis with the apex closest to the occlusion and the base at the periphery of the organ the margins will become better defined with time with a narrow rim of congestion attributable to inflammation at the edge of the lesion relatively few extravasated red cells are lysed so the resulting hemosiderosis is limited and results in a progressively more pale area of infarction with time ischemic coagulative necrosis results and fibrosis of the affected area develops from the reparative response beginning at the preserved margins and working its way inwards one exception to coagulative necrosis is the brain which undergoes liquefactive necrosis in response to infarction
anencephaly is the absence of a major portion of the brain skull and scalp that occurs during embryonic development it is a cephalic disorder that results from a neural tube defect that occurs when the rostral head end of the neural tube fails to close usually between the 23 rd and 26 th day following conception strictly speaking the greek term translates as no in head that is totally lacking the inside part of the head i e the brain but it is accepted that children born with this disorder usually only lack a telencephalon the largest part of the brain consisting mainly of the cerebral hemispheres including the neocortex which is responsible for cognition the remaining structure is usually covered only by a thin layer of membrane — skin bone meninges etc are all lacking with very few exceptions infants with this disorder do not survive longer than a few hours or possibly days after their birth
anesthesia dolorosa or anaesthesia dolorosa or deafferentation pain is pain felt in an area usually of the face which is completely numb to touch the pain is described as constant burning aching or severe it can be a side effect of surgery involving any part of the trigeminal system and occurs after 1 – 4 of peripheral surgery for trigeminal neuralgia no effective medical therapy has yet been found several surgical techniques have been tried with modest or mixed results the value of surgical interventions is difficult to assess because published studies involve small numbers of mixed patient types and little long term follow up gasserian ganglion stimulation is stimulation of the gasserian ganglion with electric pulses from a small generator implanted beneath the skin there are mixed reports including some reports of marked some of moderate and some of no improvement further studies of more patients with longer follow up are required to determine the efficacy of this treatment deep brain stimulation was found in one review to produce good results in forty five percent of 106 cases though relief may not be permanent several years of relief may be achieved with this technique mesencephalotomy is the damaging of the junction of the trigeminal tract and the periaqueductal gray in the brain and has produced pain relief in a group of patients with cancer pain but when applied to six anesthesia dolorosa patients no pain relief was achieved and the unpleasant sensation was in fact increased dorsal root entry zone lesioning damaging the point where sensory nerve fibers meet spinal cord fibers produced favorable results in some patients and poor results in others with incidence of ataxia at 40 patient numbers were small follow up was short and existing evidence does not indicate long term efficacy one surgeon treated thirty five patients using trigeminal nucleotomy damaging the nucleus caudalis and reported 66 abolition of allodynia and a marked reduction in or less frequently complete abolition of deep background pain
anetoderma also known as anetoderma maculosa anetoderma maculosa cutis atrophia maculosa cutis and macular atrophy is a localized laxity of the skin with herniation or outpouching resulting from abnormal dermal elastic tissue anetoderma comes in three types primary anetoderma jadassohn – pellizzari anetoderma is a benign condition with focal loss of dermal elastic tissue jadassohn pellizzari is one of two major classifications of primary anetoderma the other being schweninger – buzzi anetoderma the difference between the two is that jadassohn – pellizzari anetoderma is preceded by inflammatory lesions schweninger – buzzi anetoderma is a cutaneous condition characterized by loss of dermal elastic tissue secondary anetoderma familial anetoderma
aneuploidy is the presence of an abnormal number of chromosomes in a cell for example a human cell having 45 or 47 chromosomes instead of the usual 46 it does not include a difference of one or more complete sets of chromosomes which is called euploidy an extra or missing chromosome is a common cause of genetic disorders including some human birth defects some cancer cells also have abnormal numbers of chromosomes aneuploidy originates during cell division when the chromosomes do not separate properly between the two cells different species normally have different numbers of chromosomes from one another and the terms aneuploid and polyploid refer to the chromosome number being different from the usual number for that species chromosome abnormalities are detected in 1 of 160 live human births apart from sex chromosome disorders most cases of aneuploidy result in death of the developing fetus miscarriage the most common extra autosomal chromosomes among live births are 21 18 and 13
an aneurysm is a localized blood filled balloon like bulge in the wall of a blood vessel aneurysms can occur in any blood vessel with examples including aneurysms of the circle of willis in the brain aortic aneurysms affecting the thoracic aorta and abdominal aortic aneurysms aneurysms can also occur within the heart as an aneurysm increases in size the risk of rupture increases a ruptured aneurysm can lead to bleeding aneurysms are a result of a weakened blood vessel wall and can be a result of a hereditary condition or an acquired disease aneurysms can also be a nidus for clot formation thrombosis and embolization the word is from greek ἀνεύρυσμα aneurysma dilation from ἀνευρύνειν aneurynein to dilate
an aneurysm of heart refers to an aneurysm involving cardiac tissue
aneurysm of the aortic sinus also known as the sinus of valsalva is comparatively rare when present it is usually in either the right 65 85 or in the noncoronary 10 30 sinus rarely in the left 5 sinus
aneurysmal bone cyst abbreviated abc is an osteolytic bone neoplasm characterized by several sponge like blood or serum filled generally non endothelialized spaces of various diameters
angel wing also known as airplane wing slipped wing crooked wing and drooped wing is a syndrome that affects primarily aquatic birds such as geese and ducks in which the last joint of the wing is twisted with the wing feathers pointing out laterally instead of lying against the body males develop it more frequently than females it has also been reported in goshawks bustard chicks and psittacine birds budgerigars macaws and conures the syndrome manifests as an incurable anatomical condition which is acquired in young birds due to a high calorie diet especially one high in proteins and or low in vitamin d vitamin e and manganese one or both carpus wrist joints are retarded in their development relative to the rest of the wing for reasons unknown if only one wing is affected it is usually the left one the result is a wrist which is twisted outwards and unable to perform its usual function angel wing symptoms include stripped remiges flight feathers in the wrist area or remiges protruding from wings at odd angles in extreme cases the stripped feathers may resemble sickly blue straws protruding from wings in adult birds the disease is incurable and usually leads to an early death as affected birds are rendered effectively or totally flightless in young birds wrapping the wing and binding it against the bird s flank together with feeding the bird a more nutritionally balanced diet can reverse the damage the theorized causes of angel wing are genetics the excessive intake of carbohydrates and proteins together with insufficient intake of vitamin e low dietary calcium and manganese deficiency angel wing is occasionally observed in waterfowl residing near humans including domestic fowl and the disease can sometimes be observed in areas where geese or ducks are excessively fed bread other examples are not fed bread at all some have refrained from feeding waterfowl white bread popcorn or other human foodstuffs without a noticeable change in the incidence of the deformity duck seed is an alternative for duck feeders
the angeli – rimini reaction is an organic reaction between an aldehyde and the sulfonamide n hydroxybenzenesulfonamide in presence of base forming an hydroxamic acid the angeli rimini reaction the other reaction product is a sulfinic acid the reaction was discovered by the two italian chemists angelo angeli and e rimini and was published in 1896
angelman syndrome as is a neurodevelopmental disorder characterized by severe intellectual and developmental disability sleep disturbance seizures jerky movements especially hand flapping frequent laughter or smiling and usually a happy demeanor as is a classic example of genomic imprinting in that it is caused by deletion or inactivation of genes on the maternally inherited chromosome 15 while the paternal copy which may be of normal sequence is imprinted and therefore silenced the sister syndrome prader – willi syndrome is caused by a similar loss of paternally inherited genes and maternal imprinting as is named after a british pediatrician harry angelman who first described the syndrome in 1965 an older alternative term for as happy puppet syndrome is generally considered pejorative and stigmatizing so it is no longer the accepted term people with as are sometimes referred to as angels both because of the syndrome s name and because of their youthful happy appearance
angina bullosa haemorrhagica abh is a condition of the mucous membranes characterized by the sudden appearance of one or more blood blisters within the oral cavity the lesions which may be caused by mild trauma to the mouth tissues such as hot foods typically rupture quickly and heal without scarring or further discomfort the condition is not serious except in rare cases where a large bulla that does not rupture spontaneously may cause airway obstruction the blisters usually affect the palate or oropharynx and are often long lived to the extent that patients burst them for symptomatic relief
angina pectoris commonly known as angina is the sensation of chest pain pressure or squeezing often due to ischemia of the heart muscle from obstruction or spasm of the coronary arteries while angina pectoris can derive from anemia abnormal heart rhythms and heart failure its main cause is coronary artery disease an atherosclerotic process affecting the arteries feeding the heart the term derives from the latin angere to strangle and pectus chest and can therefore be translated as a strangling feeling in the chest there is a weak relationship between severity of pain and degree of oxygen deprivation in the heart muscle i e there can be severe pain with little or no risk of a myocardial infarction heart attack and a heart attack can occur without pain in some cases angina can be quite severe and in the early 20 th century this was known to be a signal of impending death however given current medical therapies the outlook has improved substantially people with an average age of 62 years who have moderate to severe degrees of angina grading by classes ii iii and iv have a 5 year mortality rate of approximately 8 worsening crescendo angina attacks sudden onset angina at rest and angina lasting more than 15 minutes are symptoms of unstable angina usually grouped with similar conditions as the acute coronary syndrome as these may precede a heart attack they require urgent medical attention and are in general treated in similar fashion to myocardial infarction
an anginal equivalent is a symptom such as shortness of breath dyspnea diaphoresis extreme fatigue or pain at a site other than the chest occurring in a patient at high cardiac risk anginal equivalents are considered to be symptoms of myocardial ischemia anginal equivalents are considered to have the same importance as angina pectoris in patients presenting with elevation of cardiac enzymes or certain ekg changes which are diagnostic of myocardial ischemia
in medicine gastroenterology angiodysplasia is a small vascular malformation of the gut it is a common cause of otherwise unexplained gastrointestinal bleeding and anemia lesions are often multiple and frequently involve the cecum or ascending colon although they can occur at other places treatment may be with colonoscopic interventions angiography and embolization medication or occasionally surgery
angioedema also known as angiooedema quincke s edema and angioneurotic edema is the rapid swelling edema of the dermis subcutaneous tissue mucosa and submucosal tissues it is very similar to urticaria but urticaria commonly known as hives occurs in the upper dermis cases where angioedema progresses rapidly should be treated as a medical emergency as airway obstruction and suffocation can occur epinephrine may be life saving when the cause of angioedema is allergic in the case of hereditary angioedema treatment with epinephrine has not been shown to be helpful
angioimmunoblastic t cell lymphoma aitl sometimes misspelled ailt formerly known as angioimmunoblastic lymphadenopathy with dysproteinemia is a mature t cell lymphoma of blood or lymph vessel immunoblasts characterized by a polymorphous lymph node infiltrate showing a marked increase in follicular dendritic cells fdcs and high endothelial venules hevs and systemic involvement it is also known as immunoblastic lymphadenopathy lukes collins classification and aild type lymphogranulomatosis x t cell lymphoma kiel classification
angiokeratoma is a benign cutaneous lesion of capillaries resulting in small marks of red to blue color and characterized by hyperkeratosis angiokeratoma corporis diffusum refers to fabry s disease but this is usually considered a distinct condition
angiolipoma is a subcutaneous nodule with vascular structure having all other features of a typical lipoma they are commonly painful
angiolymphoid hyperplasia with eosinophilia also known as epithelioid hemangioma histiocytoid hemangioma inflammatory angiomatous nodule intravenous atypical vascular proliferation papular angioplasia inflammatory arteriovenous hemangioma and pseudopyogenic granuloma usually presents with pink to red brown dome shaped dermal papules or nodules of the head or neck especially about the ears and on the scalp it or a similar lesion has been suggested as a feature of igg 4 related skin disease which is the name used for skin manifestations of igg 4 related disease
angiomas are benign tumors derived from cells of the vascular or lymphatic vessel walls endothelium or derived from cells of the tissues surrounding these vessels angiomas are a frequent occurrence as patients age but they might be an indicator of systemic problems such as liver disease they are not commonly associated with malignancy
angioma serpiginosum is characterized by minute copper colored to bright red angiomatous puncta that have a tendency to become papular
angiomatoid fibrous histiocytoma abbreviated afh is a rarely metastasizing tumour that affects children and young adults
angiomatosis is a non neoplastic condition presenting with little knots of capillaries in various organs it consists of many angiomas it is associated with von hippel lindau disease and is a rare genetic multi system disorder characterized by the abnormal growth of tumours in the body symptoms may include headaches problems with balance and walking dizziness weakness of the limbs vision problems and high blood pressure prognosis depends on the size and location of the tumour untreated angiomatosis may lead to blindness and or permanent brain damage death may occur with complications in the kidney or brain these tend to be cavernous hemangiomas which are sharply defined sponge like tumors composed of large dilated cavernous vascular spaces they often appear in von hippel lindau disease bacillary angiomatosis klippel trenaunay weber syndrome sturge weber syndrome
angiomyofibroblastoma is an uncommon benign mesenchymal tumor it occurs almost in the vulvo vaginal area of women but can also be observed in men the gross features of amfb are well circumscribed usually most tumors grow slowly and patients do not feel pain it also has low tendency for local recurrence
angiomyolipomas are the most common benign tumour of the kidney and are composed of blood vessels smooth muscle cells and fat cells angiomyolipomas are strongly associated with the genetic disease tuberous sclerosis in which most individuals will have several angiomyolipomas affecting both kidneys they are also commonly found in women with the rare lung disease lymphangioleiomyomatosis angiomyolipomas are less commonly found in the liver and rarely in other organs whether associated with these diseases or sporadic angiomyolipomas are caused by mutations in either the tsc 1 or tsc 2 genes which govern cell growth and proliferation although regarded as benign angiomyolipomas may grow such that kidney function is impaired or the blood vessels may dilate and burst leading to haemorrhage large angiomyolipoma can be treated with embolisation drug therapy for angiomyolipoma is at the research stage the tuberous sclerosis alliance has recently published guidelines that provide useful information for the diagnosis surveillance and management of angiomyolipomas
angiosarcoma is a cancer of the cells that line the walls of blood vessels or lymphatic vessels the lining of the vessel walls is called the endothelium cancers from the walls of blood vessels are called hemangiosarcomas and cancers from the walls of lymphatic vessels are called lymphangiosarcomas because the cancers are carried by the blood flow or lymphatic flow they can more easily metastisize to distant sites particularly the liver and lungs most tumors of visceral blood and lymphatic vessel walls are cancerous malignant hemangiosarcomas and lymphangiosarcomas of the skin are not common kaposi s sarcoma is a different type of cancer that also involves endothelial type cells angiosarcomas will show signs of hemorrhage and necrosis pathologically tumor cells will show increased nuclear to cytoplasm ratio nuclear hyperchromasia nuclear pleomorphism and high mitotic activity will be observed angiosarcoma of the liver a rare fatal tumor has been seen in workers intensively exposed to the gas vinyl chloride monomer vcm for prolonged periods while working in polyvinyl chloride pvc polymerization plants it has also been associated with individuals exposed to arsenic containing insecticides and thorotrast in dogs hemangiosarcoma is relatively common especially in larger breeds such as golden retrievers and labrador retrievers
angiostrongyliasis is an infection by a nematode from the angiostrongylus genus of kidney and alimentary tract roundworms for example infection with angiostrongylus cantonensis can occur after consuming raw giant african land snails great grey slugs or other mollusks in humans angiostrongylus is the most common cause of eosinophilic meningitis or meningoencephalitis frequently the infection will resolve without treatment or serious consequences but in cases with a heavy load of parasites the infection can be so severe it can cause permanent damage to the cns or death
angle trisection is a classical problem of compass and straightedge constructions of ancient greek mathematics it concerns construction of an angle equal to one third of a given arbitrary angle using only two tools an unmarked straightedge and a compass the problem as stated is generally impossible to solve as shown by pierre wantzel in 1837 however although there is no way to trisect an angle in general with just a compass and a straightedge some special angles can be trisected for example it is relatively straightforward to trisect a right angle that is to construct an angle of measure 30 degrees it is possible to trisect an arbitrary angle by using tools other than straightedge and compass for example neusis construction also known to ancient greeks involves simultaneous sliding and rotation of a marked straightedge which cannot be achieved with the original tools other techniques were developed by mathematicians over the centuries because it is defined in simple terms but complex to prove unsolvable the problem of angle trisection is a frequent subject of pseudomathematical attempts at solution by naive enthusiasts these solutions often involve mistaken interpretations of the rules or are simply incorrect
the anglo german naval arms race of the early 20 th century preceded and was one of the several intertwined causes for world war i there were also other naval buildups in several other countries which were emerging as great powers such as the united states and japan and in south america
there are seven known rings of the anglo saxon period 9 th or 10 th century bearing runic inscriptions the most notable of these are the bramham moor ring found in the 18 th century and the kingmoor ring found 1817 inscribed with a nearly identical magical formula read as ærkriufltkriuriþonglæstæpontol a third ring found before 1824 perhaps identical with a ring found in 1773 at linstock castle in carlisle has a magical inscription of a similar type ery ri uf dol yri þol wles te pote nol the remaining four rings have much shorter inscriptions wheatley hill durham found 1993 now in the british museum late 8 th century inscription h ring ic hatt æ i am called a ring coquet island northumberland found before 1866 now lost inscription þis is this is … cramond edinburgh found 1869 70 now in the national museum of scotland 9 th 10 th century inscription ewor el u thames exchange london found 1989 now in the museum of london inscription fuþni ine
angor animi also referred to as angina animi gairdner s disease and also angina pectoris sine dolore in medicine is a symptom defined as a patient s perception that they are in fact dying most cases of angor animi are found in patients suffering from acute coronary syndrome cardiac related chest pain such as angina it is however occasionally found in patients suffering from other conditions angor animi is differentiated from a fear or desire for death since angor animi refers to a patient s actual and genuine belief that they are in the present act of dying
angourie point is a surf break in the small township of yamba on the north coast of new south wales australia angourie point is an exposed point break that has consistent surf and surf offshore winds are from the southwest groundswells and wind swells are good and the best swell direction is from the east or south east
anguilliformity is a morphological pattern in fishes named for and typified by the eels anguilliform fish have a long slender body and travel by anguilliform motion the caudal fin is often emphasized with the other fins reduced absent or fused with the caudal fin anguilliformity has evolved independently in many groups including among others anguilliformes the eels synbranchiformes the swamp eels clariidae the airbreathing catfishes dipnoi the lungfishes cobitidae the loaches gymnotidae the knifefishes including the electric eel electrophorus electricus
angular cheilitis ac is inflammation of one or both corners of the mouth often the corners are red with skin breakdown and crusting it can also be itchy or painful the condition can last for days to years angular cheilitis is a type of cheilitis inflammation of the lips angular cheilitis can be caused by infection irritation or allergies infections include by the fungi such as candida albicans and bacteria such as staph aureus irritants include poorly fitting dentures licking the lips or drooling mouth breathing resulting in a dry mouth sun exposure overclosure of the mouth smoking and minor trauma allergies may include to substances like toothpaste makeup and food often a number of factors are involved other factors may include poor nutrition or poor immune function diagnosis may be helped by testing for infections and patch testing for allergies treatment for angular cheilitis is typically based on the underlying causes along with the use of a barrier cream frequently an antifungal and antibacterial cream is also tried angular cheilitis is a fairly common problem with estimates that it affects 0 7 of the population it occurs most often in the 30 s to 60 s although is also relatively common in children in the developing world iron and vitamin deficiencies are a common cause
in waveguide design and construction angular misalignment loss is power loss caused by the deviation from optimum angular alignment of the axes of source to waveguide waveguide to waveguide or waveguide to detector the waveguide may be dielectric an optical fiber or metallic angular misalignment loss does not include lateral offset loss and longitudinal offset loss source from federal standard 1037 c
the angular momentum problem is a problem in astrophysics by which the angular momentum of a protoplanetary disk is misappropriated when compared to models during stellar birth the sun and other stars are predicted by models to be rotating considerably faster than they actually are the sun for example only accounts for about 0 3 percent of the total angular momentum of the solar system while about 60 is attributed to jupiter
anhedonia ˌænhiˈdoʊniə an hee doh nee ə greek ἀν an without and ἡδονή hēdonē pleasure is the inability to experience pleasure from activities usually found enjoyable e g exercise hobbies music sexual activities or social interactions while earlier definitions of anhedonia emphasized pleasurable experience more recent models have highlighted the need to consider different aspects of enjoyable behavior such as motivation or desire to engage in activities motivational anhedonia as compared to the level of enjoyment of the activity itself consummatory anhedonia according to william james the term was coined by théodule armand ribot one can distinguish many kinds of pathological depression sometimes it is mere passive joylessness and dreariness discouragement dejection lack of taste and zest and spring professor ribot proposed the name anhedonia to designate this condition the state of anhedonia if i may coin a new word to pair off with analgesia he writes has been very little studied but it exists anhedonia can be a characteristic of mental disorders including mood disorders attention deficit hyperactivity disorder schizoaffective disorder borderline personality disorder schizoid personality disorder dysthymia and schizophrenia for example the 7 th dsm iv criterion for borderline personality disorder chronic feelings of emptiness results indicate that emptiness is negligibly related to boredom is closely related to feeling hopeless pathologically lonely and isolated and is a robust predictor of depression and suicidal ideation but not anxiety or suicide attempts findings are consistent with dsm iv revisions regarding the 7 th criterion for borderline personality disorder in addition findings suggest the emptiness reflects pathologically low positive affect and significant psychiatric distress people affected with schizophrenia often describe themselves as feeling emotionally empty mood disturbances are commonly observed in many psychiatric disorders such as major depressive disorder disturbing mood changes may occur resultant to stressful life events and they are not uncommon during times of physical illness while anhedonia can be a feature of such mood changes they are not mutually inclusive
aniconism is the absence of material representations of the natural and supernatural world in various cultures particularly in the monotheistic abrahamic religions it may extend from only god and deities to saint characters all living beings and everything that exists the phenomenon is generally codified by the religious traditions and as such becomes a taboo when enforced by the physical destruction of images aniconism becomes iconoclasm the word itself derives from greek εικων image with the negative prefix an greek privative alpha and the suffix ism greek ισμος
animal type melanoma is a cutaneous condition and is characterized by nodules and fascicles of epithelioid melanocytes with pleomorphic nuclei and striking hyperpigmentation dendritic cells numerous melanophages and sometimes an inflammatory infiltrate of lymphocytes
animal attacks are a common cause of either human fatalities or injuries the frequency of animal attacks varies with geographical location in the united states a person is more likely to be killed by an animal than they are to die from being hit by lightning animal attacks have been identified as a major public health problem in 1997 it was estimated that up to 2 million animal bites occur each year in the united states injuries caused by animal attacks result in thousands of fatalities worldwide every year all causes of death are reported to the centers for disease control and prevention each year medical injury codes are used to identify specific cases the world health organization uses identical coding though it is unclear whether all countries keep track of fatalities caused by animals
an animal bite is a wound usually lacerations caused by the teeth an animal bite usually results in a break in the skin but also includes contusions from the excessive pressure on body tissue from the bite the contusions can occur without a break in the skin bites can be provoked or unprovoked other bite attacks may be apparently unprovoked biting is a physical action not only describing an attack but it is a normal response in an animal as it eats carries objects softens and prepares food for its young removes ectoparasites from its body surface removes plant seeds attached to its fur or hair scratching itself and grooming other animals animal bites often result in serious infections and mortality animal bites not only include injuries from the teeth of reptiles mammals but fish and amphibians arthropods can also bite and leave injuries
animal coloration is the general appearance of an animal resulting from the reflection or emission of light from its surfaces some animals are brightly coloured while others are hard to see in some species such as the peacock the male has strong patterns conspicuous colours and is iridescent while the female is far less visible there are several separate reasons why animals have evolved colours camouflage enables an animal to remain hidden from view signalling enables an animal to communicate information such as warning of its ability to defend itself aposematism animals also use colour in advertising signalling services such as cleaning to animals of other species to signal sexual status to other members of the same species and in mimicry taking advantage of another species warning coloration some animals use colour to divert attacks by startle deimatic behaviour surprising a predator e g with eyespots or other flashes of colour and possibly by motion dazzle confusing a predator s attack by moving a bold pattern such as zebra stripes rapidly some animals are coloured for physical protection such as having pigments in the skin to protect against sunburn while some frogs can lighten or darken their skin for temperature regulation finally animals can be coloured incidentally for example blood is red because the haem pigment needed to carry oxygen is red animals coloured in these ways can have striking natural patterns animals produce colour in different ways pigments are particles of coloured material chromatophores are cells containing pigment which can change their size to make their colour more or less visible some animals including many butterflies and birds have microscopic structures in scales bristles or feathers which give them brilliant iridescent colours other animals including squid and some deep sea fish can produce light sometimes of different colours animals often use two or more of these mechanisms together to produce the colours and effects they need
animal geography is a subfield of the nature society human environment branch of geography as well as a part of the larger interdisciplinary umbrella of human animal studies has animal geography is defined as the study of “ the complex entangling s of human animal relations with space place location environment and landscape ” or “ the study of where when why and how nonhuman animals intersect with human societies ” recent work advances these perspectives to argue about an ecology of relations in which humans and animals are enmeshed taking seriously the lived spaces of animals themselves and their sentient interactions with not just human but other nonhuman bodies as well the animal geography specialty group of the association of american geographers was founded in 2009 by monica ogra and julie urbanik the animal geography research network was founded in 2011 by daniel allen
animal lead poisoning also known as avian plumbism or avian saturnism for birds is a veterinary condition and pathology caused by increased levels of the heavy metal lead in animal s body lead interferes with a variety of body and natural processes it is toxic to many organs and tissues including the heart bones intestines kidneys and reproductive and nervous systems it mainly affects the haematopoietic system it also affects the sulfhydryl group containing enzymes and also thiol content of erythrocyte it inhibits the enzyme delta amino levaminic acid dehydrogenase enzyme ala which is present in the rbc it is therefore particularly toxic to young animals mainly dogs and cattle as in humans animal lead poisoning may be acute from intense exposure of short duration or chronic from repeat low level exposure over a prolonged period acute intoxication can quickly lead to death
animal navigation is the ability of many animals to find their way accurately without maps or instruments birds such as the arctic tern insects such as the monarch butterfly and fish such as the salmon regularly migrate thousands of miles to and from their breeding grounds and many other species navigate effectively over shorter distances dead reckoning navigating from a known position using only information about one s own speed and direction was suggested by charles darwin in 1873 as a possible mechanism in the 20 th century karl von frisch showed that honey bees can navigate by the sun by the polarization pattern of the blue sky and by the earth s magnetic field of these they rely on the sun when possible william tinsley keeton showed that homing pigeons could similarly make use of a range of navigational cues including the sun earth s magnetic field olfaction and vision ronald lockley demonstrated that a species of small seabird the manx shearwater could orient themselves and fly home at full speed when released far from home provided either the sun or the stars were visible several species of animal can integrate cues of different types to orient themselves and navigate effectively insects and birds are able to combine learned landmarks with sensed direction from the earth s magnetic field or from the sky to identify where they are and so to navigate internal maps are often formed using vision but other senses including olfaction and echolocation may also be used the ability of wild animals to navigate may be adversely affected by products of human activity for example there is evidence that pesticides may interfere with bee navigation and that lights may harm turtle navigation
animal african trypanosomiasis also known as nagana and nagana pest is a disease of vertebrate animals the disease is caused by trypanosomes of several species in the genus trypanosoma such as trypanosoma brucei trypanosoma vivax causes nagana mainly in west africa although it has spread to south america the trypanosomes infect the blood of the vertebrate host causing fever weakness and lethargy which lead to weight loss and anemia in some animals the disease is fatal unless treated the trypanosomes are transmitted by tsetse flies an interesting feature is the remarkable tolerance to nagana pathology shown by some breeds of cattle notably the n dama – a west african bos taurus breed this contrasts with the susceptibility shown by east african bos indicus cattle such as the zebu this disease is the nonhuman animal counterpart of human african trypanosomiasis also known as sleeping sickness
aniridia is the absence of the iris usually involving both eyes it can be congenital or caused by a penetrant injury isolated aniridia is a congenital disorder which is not limited to a defect in iris development but is a panocular condition with macular and optic nerve hypoplasia cataract and corneal changes vision may be severely compromised and the disorder is frequently associated with a number of ocular complications nystagmus amblyopia buphthalmos and cataract aniridia in some individuals occurs as part of a syndrome such as wagr syndrome kidney nephroblastoma wilms tumour genitourinary anomalies and intellectual disability or gillespie syndrome cerebellar ataxia
aniridia ataxia renal agenesis psychomotor retardation is a rare genetic disorder characterized by missing irises of the eye ataxia psychomotor retardation and abnormal kidneys
aniseikonia is an ocular condition where there is a significant difference in the perceived size of images it can occur as an overall difference between the two eyes or as a difference in a particular meridian
anismus or dyssynergic defecation refers to the failure of the normal relaxation of pelvic floor muscles during attempted defecation anismus can occur in both children and adults and in both men and women although it is more common in women it can be caused by physical defects or it can occur for other reasons or unknown reasons anismus that has a behavioral cause could be viewed as having similarities with parcopresis or psychogenic fecal retention symptoms include tenesmus the sensation of incomplete emptying of the rectum after defecation has occurred and constipation retention of stool may result in fecal loading retention of a mass of stool of any consistency or fecal impaction retention of a mass of hard stool this mass may stretch the walls of the rectum and colon causing megarectum and or megacolon respectively liquid stool may leak around a fecal impaction possibly causing degrees of liquid fecal incontinence this is usually termed encopresis or soiling in children and fecal leakage soiling or liquid fecal incontinence in adults anismus is usually treated with dietary adjustments such as dietary fiber supplementation it can also be treated with a type of biofeedback therapy during which a sensor probe is inserted into the person s anal canal in order to record the pressures exerted by the pelvic floor muscles these pressures are visually fed back to the patient via a monitor who can regain the normal coordinated movement of the muscles after a few sessions some researchers have suggested that anismus is an over diagnosed condition since the standard investigations or digital rectal examination and anorectal manometry were shown to cause paradoxical sphincter contraction in healthy controls who did not have constipation or incontinence due to the invasive and perhaps uncomfortable nature of these investigations the pelvic floor musculature is thought to behave differently than under normal circumstances these researchers went on to conclude that paradoxical pelvic floor contraction is a common finding in healthy people as well as in people with chronic constipation and stool incontinence and it represents a non specific finding or laboratory artifact related to untoward conditions during examination and that true anismus is actually rare
anisocoria is a condition characterized by an unequal size of the eyes pupils affecting 20 of the population it can be an entirely harmless condition or a symptom of more serious medical problems
anisocytosis is a medical term meaning that a patient s red blood cells are of unequal size this is commonly found in anemia and other blood conditions false diagnostic flagging may be triggered by an elevated wbc count agglutinated rbcs rbc fragments giant platelets or platelet clumps in addition it is a characteristic feature of bovine blood the red cell distribution width rdw is a measurement of anisocytosis and is calculated as a coefficient of variation of the distribution of rbc volumes divided by the mean corpuscular volume mcv
anisomastia is a medical condition in which there is a severe asymmetry or unequalness in the size of the breasts generally related to a difference in volume in other words when one of the breasts is much larger than the other in contrast to anisomastia a slightly asymmetry of the breasts is common anisomastia may be corrected by surgical breast augmentation or reduction
anisometropia is the condition in which the two eyes have unequal refractive power each eye can be nearsighted myopia farsighted hyperopia or a combination of both which is called antimetropia generally a difference in power of two diopters or more is the accepted threshold to label the condition anisometropia in certain types of anisometropia the visual cortex of the brain will not use both eyes together binocular vision and will instead suppress the central vision of one of the eyes if this occurs often enough during the first 10 years of life while the visual cortex is developing it can result in amblyopia a condition where even when correcting the refractive error properly the person is still not correctable to 20 20 the name is from four greek components an not iso same metr measure ops eye estimated 6 of subjects aged 6 to 18 have anisometropia
an ankle fracture is a break of the ankle bones it is typically diagnosed by x ray treatment is with splinting casting or surgery in children ankle fractures occur in about 1 per 1000 per year
ankyloglossia also known as tongue tie is a congenital oral anomaly that may decrease mobility of the tongue tip and is caused by an unusually short thick lingual frenulum a membrane connecting the underside of the tongue to the floor of the mouth ankyloglossia varies in degree of severity from mild cases characterized by mucous membrane bands to complete ankyloglossia whereby the tongue is tethered to the floor of the mouth
ankylosing hyperostosis is a form of dorsopathy
ankylosing spondylitis as is a type of arthritis in which there is long term inflammation of the joints of the spine typically where the spine joins the pelvis is also affected occasionally other joints such as the shoulders or hips are involved eye and bowel problems may also occur often the symptom of back pain comes and goes stiffness of the affected joints generally worsens over time the cause of ankylosing spondylitis is unknown however it is believed to involve a combination of genetic and environmental factors the underlying mechanism is believed to be autoimmune or autoinflammatory diagnosis is typically based on the symptoms with support from medical imaging and blood tests it is a type of seronegative spondyloarthropathies meaning that the person tests negative for the antibody called rheumatoid factor there is no cure for ankylosing spondylitis treatments can improve symptoms and possibly prevent worsening this may include medication exercise and surgery medications used include nsaids steroids disease modifying antirheumatic drugs such as methotrexate and biologic agents such as infliximab between 0 1 and 1 8 of people are affected onset is typically in young adults males are more often affected than females the condition was first fully described in the late 1600 s by bernard connor however skeletons with ankylosing spondylitis are found in egyptian mummies the word is from greek ankylos meaning stiffening of a joint spondylos meaning vertebra and itis meaning inflammation
ankylosis or anchylosis from greek ἀγκύλος bent crooked is a stiffness of a joint due to abnormal adhesion and rigidity of the bones of the joint which may be the result of injury or disease the rigidity may be complete or partial and may be due to inflammation of the tendinous or muscular structures outside the joint or of the tissues of the joint itself noma — a gangrenous disease still widespread among malnourished children living on the borders of the sahara desert — can cause ankylosis of the maxilla and mandible impairing the ability to speak and eat when the structures outside the joint are affected the term false ankylosis has been used in contradistinction to true ankylosis in which the disease is within the joint when inflammation has caused the joint ends of the bones to be fused together the ankylosis is termed osseous or complete and is an instance of synostosis excision of a completely ankylosed shoulder or elbow may restore free mobility and usefulness to the limb ankylosis is also used as an anatomical term bones being said to ankylose or anchylose when from being originally distinct they coalesce or become so joined together that no motion can take place between them
ann c palmenberg is a professor of virology and biochemistry at the university of wisconsin madison she received her b s from st lawrence university and her ph d from the university of wisconsin madison dr palmenberg has been given numerous awards for her research and involvement within the scientific community such as fellow for the american academy of microbiology news articles have been published about her work within virology including an article in the milwaukee journal sentinel on her findings on the common cold
sophie anne hunt known by the name of anna thillon calcutta or london 1819 torquay 5 may 1903 was an operatic singing sensation in the united states based in san francisco california and then new york new york she performed in the former city s first professional season she had much of her training in france where she studied with marco bordogni giovanni tadolini and claude thomas thillon conductor of the havre philharmonic society whom she married after appearances in the provinces she made her debut at the paris théâtre de la renaissance in 1738 in the title role of albert grisar s lady melvil in 1740 she moved to the opéra comique where she created the roles of catarina in les diamants de la couronne 1841 and casilda in la part du diable 1843 by daniel auber who had a passion for her she made her english debut in 1844 at the london princess s theatre repeating the role of catarina she later sang at the drury lane creating stella in balfe s the enchantress her american career began in 1851 but she retired four years later after her relatively early retirement she lived in the english seaside town of torquay census records and died there a widow at 84 there is no record of any children
annual ryegrass toxicity argt is the poisoning of livestock from toxin contained in bacterially infected annual ryegrass lolium rigidum the toxin is produced by the bacterium rathayibacter toxicus formerly clavibacter toxicus which is carried into the ryegrass by the nematode anguina funesta
annular elastolytic giant cell granuloma also known as giant cell elastophagocytosis meischer s granuloma miescher s granuloma of the face is a cutaneous condition characterized histologically by a dermal infiltrate of macrophages
annular erythema of infancy is a skin condition reported in children roughly six months in age characterized by transitory skin lesions that resolved without treatment within eleven months
fluidisation is a phenomenon whereby solid particulate is placed under certain conditions to cause it to behave like a fluid a fluidized bed is a system conceived to facilitate the fluidisation fluidized beds have a wide range of applications including but not limited to assisting with chemical reactions heat transfer mixing and drying a recent concept devised and patented by outotec an annular fluidized bed consists of a large central nozzle surrounded be a stationary fluidized
annular pancreas is a rare condition in which the second part of the duodenum is surrounded by a ring of pancreatic tissue continuous with the head of the pancreas this portion of the pancreas can constrict the duodenum and block or impair the flow of food to the rest of the intestines it is estimated to occur in 1 out of 12 000 to 15 000 newborns the ambiguity arises from the fact that not all cases are symptomatic
annular pustular psoriasis is a rare variant of pustular psoriasis having an annular or circinate lesion morphology that may appear at the onset of pustular psoriasis with a tendency to spread and form enlarged rings
in organic chemistry annulation from the latin for little ring occasionally annelation is a chemical reaction in which a new ring is constructed on a molecule annulation a intramolecular ring closing b transannulation c cycloaddition examples are the robinson annulation danheiser annulation and certain cycloadditions annular molecules are constructed from side on condensed cyclic segments for example helicenes and acenes in transannulation a bicyclic molecule is created by intramolecular carbon carbon bond formation in a large monocyclic ring an example is the samarium ii iodide induced ketone alkene cyclization of 5 methylenecyclooctanone which proceeds through a ketyl intermediate ketone olefin cyclization
annuloaortic ectasia is a dilation of the proximal ascending aorta and aortic annulus it may cause aortic regurgitation thoracic aortic dissection aneurysm and rupture it is often associated with marfan syndrome it can also be a complication due to tertiary syphilis in tertiary syphilis the aortic root becomes so dilated that the aortic valve becomes incompetent and cor bovinum results
anode break excitation abe is an electrophysiological phenomenon whereby a neuron fires action potentials in response to termination of a hyperpolarizing current when a hyperpolarizing current is applied across a membrane the electrical potential across the membrane falls this fall is followed by a drop in the threshold required for action potential since the threshold is directly linked to the potential across the membrane they rise and fall together abe arises after the hyperpolarizing current is terminated the potential across the cell rises rapidly with the absence of hyperpolarizing stimulus but the action potential threshold stays at its lowered value as a result the potential is suprathreshold sufficient to cause an action potential within the cell
in dentistry anodontia also called anodontia vera is a rare genetic disorder characterized by the congenital absence of all primary or permanent teeth it is associated with the group of skin and nerve syndromes called the ectodermal dysplasias anodontia is usually part of a syndrome and seldom occurs as an isolated entity congenital absence of permanent teeth can present as hypodontia usually missing 1 or 2 permanent teeth or oligodontia that is the congenital absence of more than 6 teeth congenital absence of all wisdom teeth or third molars is relatively common anodontia is the congenital absence of teeth and can occur in some or all teeth partial anodontia or hypodontia involve two dentitions or only teeth of the permanent dentition dorland s 1998 approximately 1 of the population suffers from oligodontia many denominations are attributed to this anomaly partial anodontia hypodontia oligodontia the congenital absence anodontia bilateral aplasia anodontia being the term used in controlled vocabulary medical subject headings mesh from medline which was developed by the united states national library of medicine the congenital absence of at least one permanent tooth is the most common dental anomaly and may contribute to masticator dysfunction speech impairment aesthetic problems and malocclusion shapiro and farrington 1983 absence of lateral incisors represents a major stereotype individuals with this condition are perceived as socially most aggressive compared with people without anodontia shaw 1981
anomalous aortic origin of a coronary artery aaoca from the inappropriate sinus of valsalva with an interarterial intraconal or intramural course is a rare heart defect associated with an increased risk of sudden death in children
anomalous left coronary artery from the pulmonary artery alcapa or bland white garland syndrome or white garland syndrome is a rare congenital anomaly in which the left coronary artery lca branches off the pulmonary artery instead of the aortic sinus after birth the pressure in other coronary arteries namely the rca will have a pressure that exceeds the lca and collateral circulation will increase this ultimately can lead to blood flowing from the rca into the lca retrograde and into the pulmonary artery thus forming a left to right shunt the syndrome is named for edward franklin bland paul dudley white and joseph garland
anomalous pulmonary venous connection or anomalous pulmonary venous drainage or anomalous pulmonary venous return is a congenital defect of the pulmonary veins
the term anomeric effect was introduced in 1958 the name comes from the term used to designate the c 1 carbon of a pyranose the anomeric carbon isomers that differ only in the configuration at the anomeric carbon are called anomers the anomers of glucopyranose are diastereomers with the beta anomer having an oh group pointing up equatorially and the alpha anomer having that oh group pointing down axially the anomeric effect can also be generalized to any cyclohexyl or linear system with the general formula c y c x where y is a heteroatom with one or more lone pairs and x is an electronegative atom or group the magnitude of the anomeric effect is estimated at about 1 – 2 kcal mol in the case of sugars but is different for every molecule in the above case the methoxy group on the cyclohexane ring top prefers the equatorial position however in the tetrahydropyran ring bottom the methoxy group prefers the axial position this is because in the cyclohexane ring y carbon which is not a heteroatom so the anomeric effect is not observed and sterics dominates the observed substituent position in the tetrahydropyran ring y oxygen which is a heteroatom so the anomeric effect contributes and stabilizes the observed substituent position in both cases x ome the anomeric effect is most often observed when y oxygen but can also be seen with other lone pair bearing heteroatoms in the ring such as nitrogen sulfur and phosphorus the exact method by which the anomeric effect causes stabilization is a point of controversy and several hypotheses have been proposed to explain it
anomic aphasia also known as dysnomia nominal aphasia and amnesic aphasia is a type of aphasia where an individual has consistent inability to produce words for things that they want to talk about particularly nouns and verbs anomia is a deficit of expressive language the most pervasive deficit in the aphasias is anomia some level of anomia is seen in all of the aphasias
anonychia is the absence of nails an anomaly which may be the result of a congenital ectodermal defect ichthyosis severe infection severe allergic contact dermatitis self inflicted trauma raynaud phenomenon lichen planus epidermolysis bullosa or severe exfoliative diseases
an anonymous birth is a birth where the mother gives birth to a child without disclosing her identity or where her identity remains unregistered in many countries anonymous births have been legalized for centuries in order to prevent formerly frequent killings of newborn children particularly outside of marriage in an anonymous birth the mother s right of informational self determination severely curtails the children s right to know about their biological ancestry therefore going beyond the concept of a confidential birth where the identity of the mother is registered but remains undisclosed unless the grown up child requests disclosure at a later point
anophthalmia greek ανόφθαλμος without eye is the medical term for the absence of one or both eyes both the globe human eye and the ocular tissue are missing from the orbit the absence of the eye will cause a small bony orbit a constricted mucosal socket short eyelids reduced palpebral fissure and malar prominence genetic mutations chromosomal abnormalities and prenatal environment can all cause anophthalmia anophthalmia is an extremely rare disease and is mostly rooted in genetic abnormalities it can also be associated with other syndromes
an anopsia or anopia is a defect in the visual field if the defect is only partial then the portion of the field with the defect can be used to isolate the underlying cause types of partial anopsia hemianopsia homonymous hemianopsia heteronymous hemianopsia binasal hemianopsia bitemporal hemianopsia superior hemianopia inferior hemianopia quadrantanopia the term anopsia comes from the ancient greek ἀν an un and ὄψις opsis sight
anorchia or anorchism is an xy disorder of sex development in which individuals have both testes absent at birth within a few weeks of fertilization the embryo develops rudimentary gonads testes which produce hormones responsible for the development of the reproductive system if the testes fail to develop within eight weeks the baby will develop female genitalia see swyer syndrome if the testes begin to develop but are lost or cease to function between eight and 10 weeks the baby will have ambiguous genitalia when it is born however if the testes are lost after 14 weeks the baby will have partial male genitalia with the notable absence of gonads tests include observable lack of testes low testosterone levels typical female levels elevated follicle stimulating hormone and luteinizing hormone levels xy karyotype ultrasound or magnetic resonance imaging showing absent gonadal tissue low bone density low anti müllerian hormone levels and surgical exploration for evidence of male gonadal tissue
anorectal abscess also known as an anal rectal abscess or perianal perirectal abscess is an abscess adjacent to the anus it arises from an infection at one of the anal sinuses which leads to inflammation and abscess formation most cases of perianal abscesses are sporadic though there are certain situations which elevate the risk for developing the disease such as diabetes mellitus crohn s disease chronic steroid treatment and others ischiorectal inter and intrasphincteric abscesses have been described
anorectal anomalies are medical problems affecting the structure of the anus and rectum a person with an anorectal problem would have some sort of deformative feature of the anus or rectum collectively known as an anorectal malformation examples of anorectal anomalies include anal stenosis imperforate anus proctitis anal bleeding anal fistula anal cancer anal itching hemorrhoid piles
anorectal disorders are painful but common conditions like hemorrhoids tears fistulas or abscesses that affect the anal region most people experience some form of anorectal disorder during their lifetime primary care physicians can treat most of these disorders however high risk individuals include those with hiv roughly half of whom need surgery to remedy the disorders because these disorders afflict the rectum people are often embarrassed or afraid to confer with a medical professional
anorectal varices are the dilation of collateral submucosal vessels due to backflow in the veins of the rectum typically this occurs due to portal hypertension which shunts venous blood from the portal system through the portosystemic anastomosis present at this site into the systemic venous system this can also occur in the oesophagus causing oesophageal varices and at the level of the umbilicus causing caput medusae between 44 and 78 of patients with portal hypertension get anorectal varices
anorexia is the decreased sensation of appetite while the term in non scientific publications is often used interchangeably with anorexia nervosa many possible causes exist for a decreased appetite some of which may be harmless while others indicate a serious clinical condition or pose a significant risk for example anorexia of infection is part of the acute phase response apr to infection the apr can be triggered by lipopolysaccharides and peptidoglycans from bacterial cell walls bacterial dna double stranded viral rna and viral glycoproteins which can trigger production of a variety of proinflammatory cytokines these can have an indirect effect on appetite by a number of means including peripheral afferents from their sites of production in the body by enhancing production of leptin from fat stores inflammatory cytokines can also signal to the central nervous system more directly by specialized transport mechanisms through the blood – brain barrier via circumventricular organs which are outside the barrier or by triggering production of eicosanoids in the endothelial cells of the brain vasculature ultimately the control of appetite by this mechanism is thought to be mediated by the same factors normally controlling appetite such as neurotransmitters serotonin dopamine histamine norepinephrine corticotropin releasing factor neuropeptide y and α melanocyte stimulating hormone
anorexia nervosa often referred to simply as anorexia is an eating disorder characterized by a low weight fear of gaining weight a strong desire to be thin and food restriction many people with anorexia see themselves as overweight even though they are in fact underweight if asked they usually deny they have a problem with low weight often they weigh themselves frequently eat only small amounts and only eat certain foods some will exercise excessively force themselves to vomit or use laxatives to produce weight loss complications may include osteoporosis infertility and heart damage among others women will often stop having menstrual periods the cause is not known there appear to be some genetic components with identical twins more often affected than non identical twins cultural factors also appear to play a role with societies that value thinness having higher rates of disease additionally it occurs more commonly among those involved in activities that value thinness such as high level athletics modelling and dancing anorexia often begins following a major life change or stress inducing event the diagnosis requires a significantly low weight the severity of disease is based on body mass index bmi in adults with mild disease having a bmi of greater than 17 moderate a bmi of 16 to 17 severe a bmi of 15 to 16 and extreme a bmi less than 15 in children a bmi for age percentile of less than the 5 th percentile is often used treatment of anorexia involves restoring a healthy weight treating the underlying psychological problems and addressing behaviors that promote the problem while medications do not help with weight gain they may be used to help with associated anxiety or depression a number of types of therapy may be useful including an approach where parents assume responsibility for feeding their child known as maudsley family therapy and cognitive behavioral therapy sometimes people require admission to hospital to restore weight evidence for benefit from nasogastric tube feeding however is unclear some people will just have a single episode and recover while others may have many episodes over years many complications improve or resolve with regaining of weight globally anorexia is estimated to affect two million people as of 2013 it is estimated to occur in 0 9 to 4 3 of women and 0 2 to 0 3 of men in western countries at some point in their life about 0 4 of young females are affected in a given year and it is estimated to occur ten times less commonly in males rates in most of the developing world are unclear often it begins during the teen years or young adulthood while anorexia became more commonly diagnosed during the 20 th century it is unclear if this was due to an increase in its frequency or simply better diagnosis in 2013 it directly resulted in about 600 deaths globally up from 400 deaths in 1990 eating disorders also increase a person s risk of death from a wide range of other causes including suicide about 5 of people with anorexia die from complications over a ten year period the term anorexia nervosa was first used in 1873 by william gull to describe this condition anorexia nervosa has the highest mortality rate of any psychiatric disorder with an smr of 5 86
the differential diagnoses of anorexia nervosa an includes various types of medical and psychological conditions which may be misdiagnosed as an in some cases these conditions may be comorbid with an because the misdiagnosis of an is not uncommon for example a case of achalasia was misdiagnosed as an and the patient spent two months confined to a psychiatric hospital a reason for the differential diagnoses that surround an arise mainly because like other disorders it is primarily albeit defensively and adaptive for the individual concerned anorexia nervosa is a psychological disorder characterized by extremely reduced intake of food people suffering from aneroxia nervosa have a low self image and consider themselves overweight common behaviors and signs of someone suffering from an forcing oneself to vigorously exercise even in adverse conditions or when their health does not permit it forcing own self to urinate and excrete waste product from the body using substituted amphetamines stimulants that can reduce appetite to reduce appetite skin turning yellow
anorgasmia is a type of sexual dysfunction in which a person cannot achieve orgasm despite adequate stimulation in males it is most closely associated with delayed ejaculation anorgasmia can often cause sexual frustration anorgasmia is far more common in females 4 7 percent than in males and is especially rare in younger men the problem is greater in women who are post menopause
anosodiaphoria is a condition in which a person who suffers disability due to brain injury seems indifferent to the existence of their handicap anosodiaphoria is specifically used in association with indifference to paralysis it is a somatosensory agnosia or a sign of neglect syndrome it might be specifically associated with defective functioning of the frontal lobe of the right hemisphere joseph babinski first used the term anosodiaphoria in 1914 to describe a disorder of the body schema in which patients verbally acknowledge a clinical problem such as hemiparesis but fail to be concerned about it anosodiaphoria follows a stage of anosognosia in which there may be verbal explicit denial of the illness and after several days to weeks develop the lack of emotional response indifference is different from denial because it implies a lack of caring on the part of the patient whom otherwise acknowledges his or her deficit
anosognosia æˌnɒsɒɡˈnoʊziə æˌnɒsɒɡˈnoʊʒə from ancient greek ἀ a without νόσος nosos disease and γνῶσις gnōsis knowledge is a deficit of self awareness a condition in which a person who suffers some disability seems unaware of the existence of his or her disability it was first named by the neurologist joseph babinski in 1914 anosognosia results from physiological damage to brain structures typically to the parietal lobe or a diffuse lesion on the fronto temporal parietal area in the right hemisphere while this distinguishes the condition from denial which is a psychological defense mechanism attempts have been made at a unified explanation anosognosia is sometimes accompanied by asomatognosia a form of neglect in which patients deny ownership of their limbs
anotia no ear describes a rare congenital deformity that involves the complete absence of the pinna the outer projected portion of the ear and narrowing or absence of the ear canal this contrasts with microtia in which a small part of the pinna is present anotia and microtia may occur unilaterally only one ear affected or bilaterally both ears affected this deformity results in conductive hearing loss deafness
an anovulatory cycle is a menstrual cycle during which the ovaries do not release an oocyte therefore ovulation does not take place however a woman who does not ovulate at each menstrual cycle is not necessarily going through menopause chronic anovulation is a common cause of infertility in addition to the alteration of menstrual periods and infertility chronic anovulation can cause or exacerbate other long term problems such as hyperandrogenism or osteopenia it plays a central role in the multiple imbalances and dysfunctions of polycystic ovary syndrome during the first two years after menarche 50 of the menstrual cycles could be anovulatories it is in fact possible to restore ovulation using appropriate medication and ovulation is successfully restored in approximately 90 of cases the first step is the diagnosis of anovulation the identification of anovulation is not easy contrary to what is commonly believed women undergoing anovulation still have more or less regular periods in general patients only notice that there is a problem once they have started trying to conceive temperature charting is a useful way of providing early clues about anovulation and can help gynaecologists in their diagnosis
an ant mill is an observed phenomenon in which a group of army ants which are blind are separated from the main foraging party lose the pheromone track and begin to follow one another forming a continuously rotating circle the ants will eventually die of exhaustion it has been reproduced in laboratories and has been produced in ant colony simulations the phenomenon is a side effect of the self organizing structure of ant colonies each ant follows the ant in front of it which works until something goes wrong and an ant mill forms an ant mill was first described by william beebe in 1921 who observed a mill 1200 ft in circumference it took each ant 2 5 h to make one revolution similar phenomena have been noted in processionary caterpillars and fish
ant venom is any of or a mixture of irritants and toxins inflicted by ants most ants spray or inject a venom the main constituent of which is formic acid only in the case of subfamily formicinae
in chemistry antagonism is a phenomenon wherein two or more agents in combination have an overall effect that is less than the sum of their individual effects the word is most commonly used in this context in biochemistry and toxicology interference in the physiological action of a chemical substance by another having a similar structure for instance a receptor antagonist is an agent that reduces the response that a ligand produces when the receptor antagonist binds to a receptor on a cell an example of this is the interleukin 1 receptor antagonist the opposite of antagonism is synergy it is a negative type of synergism experiments with different combinations show that binary mixtures of phenolics can lead to either a synergetic antioxidant effect or to an antagonistic effect
antecedent contained deletion acd also called antecedent contained ellipsis is a phenomenon found in contexts containing verb phrase ellipsis and a quantifier the ellipsis appears to be contained inside its antecedent which should result in an infinite regress and thus ungrammaticality the problem arises in phrase structure grammars that take the constituent to be the fundamental unit of syntactic analysis it does not arise if the catena is taken to be the fundamental unit the catena is associated with dependency grammars dgs
the antenna effect more formally plasma induced gate oxide damage is an effect that can potentially cause yield and reliability problems during the manufacture of mos integrated circuits fabs normally supply antenna rules which are rules that must be obeyed to avoid this problem a violation of such rules is called an antenna violation the word antenna is something of a misnomer in this context — the problem is really the collection of charge not the normal meaning of antenna which is a device for converting electromagnetic fields to from electrical currents occasionally the phrase antenna effect is used in this context but this is less common since there are many effects and the phrase does not make clear which is meant figure 1 a shows a side view of a typical net in an integrated circuit each net will include at least one driver which must contain a source or drain diffusion in newer technology implantation is used and at least one receiver which will consist of a gate electrode over a thin gate dielectric see figure 2 for a detailed view of a mos transistor since the gate dielectric is so thin only a few molecules thick a big worry is breakdown of this layer this can happen if the net somehow acquires a voltage somewhat higher than the normal operating voltage of the chip historically the gate dielectric has been silicon dioxide so most of the literature refers to gate oxide damage or gate oxide breakdown as of 2007 some manufacturers are replacing this oxide with various high κ dielectric materials which may or may not be oxides but the effect is still the same once the chip is fabricated this cannot happen since every net has at least some source drain implant connected to it the source drain implant forms a diode which breaks down at a lower voltage than the oxide either forward diode conduction or reverse breakdown and does so non destructively this protects the gate oxide however during the construction of the chip the oxide may not be protected by a diode this is shown in figure 1 b which is the situation while metal 1 is being etched since metal 2 is not built yet there is no diode connected to the gate oxide so if a charge is added in any way to the metal 1 shape as shown by the lightning bolt it can rise to the level of breaking down the gate oxide in particular reactive ion etching of the first metal layer can result in exactly the situation shown the metal on each net is disconnected from the initial global metal layer and the plasma etching is still adding charges to each piece of metal leaky gate oxides although bad for power dissipation are good for avoiding damage from the antenna effect a leaky oxide can prevent a charge from building up to the point of causing oxide breakdown this leads to the somewhat surprising observation that a very thin gate oxide is less likely to be damaged than a thick gate oxide because as the oxide grows thinner the leakage goes up exponentially but the breakdown voltage shrinks only linearly
in obstetrics antepartum haemorrhage aph also prepartum hemorrhage is genital bleeding during pregnancy from the 24 th week sometimes defined as from the 20 th week gestational age to term it can be associated with reduced fetal birth weight in regard to treatment it should be considered a medical emergency regardless of whether there is pain and medical attention should be sought immediately as if it is left untreated it can lead to death of the mother and or fetus
anterior cerebral artery syndrome is a condition whereby the blood supply from the anterior cerebral artery aca is restricted leading to a reduction of the function of the portions of the brain supplied by that vessel the medial aspects of the frontal and parietal lobes basal ganglia anterior fornix and anterior corpus callosum depending upon the area and severity of the occlusion signs and symptoms may vary within the population affected with aca syndrome blockages to the proximal a 1 segment of the vessel produce only minor deficits due to the collateral blood flow from the opposite hemisphere via the anterior communicating artery occlusions distal to this segment will result in more severe presentation of aca syndrome contralateral hemiparesis and hemisensory loss of the lower extremity is the most common symptom associated with aca syndrome
a compartment syndrome is an increased pressure within a muscular compartment that compromises the circulation to the muscles
the anterior cruciate ligament acl is an important internal stabilizer of the knee joint restraining hyperextension anterior cruciate ligament injury occurs when the ligament s biomechanical limits are exceeded over stretched often with a hyperextension mechanism formerly acl injuries occurred most often in a sports contact injury when other structures were frequently involved a particularly severe form of the contact injury is called the unhappy triad or o donaghue s triad and involves the anterior cruciate ligament the medial collateral ligament and the medial meniscus presently acl injury is more commonly a non contact injury such as a dismount from a layup in basketball both forms occur more frequently in athletes than in the general population and are prevalent in alpine skiing association football american football australian rules football basketball rugby professional wrestling martial arts and artistic gymnastics it is also known to be about three times more common in women than men the consequences of the injury depend on how much the stability of the knee is affected and the extent to which other structures have been involved and this can vary on a case by case basis if instability is evident particularly rotatory instability then the menisci will get injured sooner or later setting the scene for progressive degenerative arthritis of the knee
anterior cutaneous nerve entrapment syndrome acnes is a condition that causes chronic pain of the abdominal wall it occurs when terminal branches of the lower thoracic intercostal nerves 7 12 are ‘ entrapped ’ in abdominal muscles causing a severe localized neuropathic pain that is usually experienced at ventral portions of the abdomen it is frequently overlooked and unrecognized although the incidence is estimated to be 1 2000 patients the relative unfamiliarity with this condition often leads to significant diagnosis delays misdiagnosis often resulting in unnecessary diagnostic interventions and futile procedures physicians tend to diagnose these patients with alleged irritable bowel syndrome or functional disorders as symptoms of the condition are not dispositive
anterior interosseous syndrome or kiloh nevin syndrome i is a medical condition in which damage to the anterior interosseous nerve ain a motor branch of the median nerve causes pain in the forearm and a characteristic weakness of the pincer movement of the thumb and index finger most cases of ain syndrome are due to a transient neuritis although compression of the ain can happen trauma to the median nerve have also been reported as a cause of ain syndrome although there is still controversy among upper extremity surgeons ain syndrome is now regarded as a neuritis inflammation of the nerve in most cases this is similar to parsonage – turner syndrome although the exact etiology is unknown there is evidence that it is caused by an immune mediated response studies are limited and no randomized controlled trials have been performed regarding the treatment of ain syndrome while the natural history of ain syndrome is not fully understood studies following patients who have been treated without surgery show that symptoms can resolve starting as late as one year after onset other retrospective studies have shown that there is no difference in outcome in surgically versus nonsurgically treated patients surgical decompression is rarely indicated in ain syndrome indications for considering surgery include a known space occupying lesion that is compressing the nerve a mass and persistent symptoms beyond 1 year of conservative treatment
anterior ischemic optic neuropathy aion is a medical condition involving loss of vision due to damage to the optic nerve from insufficient blood supply aion is generally divided into two types arteritic aion or aaion and non arteritic aion naion or simply aion this article will focus primarily on non arteritic aion
anterior segment dysgenesis asd is a failure of the normal development of the tissues of the anterior segment of the eye it leads to anomalies in the structure of the mature anterior segment associated with an increased risk of glaucoma and corneal opacity peters frequently misspelled peter s anomaly is a specific type of mesenchymal anterior segment dysgenesis in which there is central corneal leukoma adhesions of the iris and cornea and abnormalities of the posterior corneal stroma descemet s membrane corneal endothelium lens and anterior chamber
anterior spinal artery syndrome also known as anterior spinal cord syndrome is a medical condition where the anterior spinal artery the primary blood supply to the anterior portion of the spinal cord is interrupted causing ischemia or infarction of the spinal cord in the anterior two thirds of the spinal cord and medulla oblongata it is characterized by loss of motor function below the level of injury loss of sensations carried by the anterior columns of the spinal cord pain and temperature and preservation of sensations carried by the posterior columns fine touch vibration and proprioception anterior spinal artery syndrome is the most common form of spinal cord infarction
anterior urethral cancer is a disease in which malignant cancer cells are found in the part of the urethra that is closest to the outside of the body
anterograde amnesia is a loss of the ability to create new memories after the event that caused the amnesia leading to a partial or complete inability to recall the recent past while long term memories from before the event remain intact this is in contrast to retrograde amnesia where memories created prior to the event are lost while new memories can still be created both can occur together in the same patient to a large degree anterograde amnesia remains a mysterious ailment because the precise mechanism of storing memories is not yet well understood although it is known that the regions involved are certain sites in the temporal cortex especially in the hippocampus and nearby subcortical regions
an anthelion plural anthelia from late greek ανθηλιος opposite the sun is a rare optical phenomenon appearing on the parhelic circle opposite to the sun as a faint white halo not unlike a sundog how anthelions are formed is disputed walter tape among others has argued they are not separate haloes but simply where various haloes caused by horizontally oriented column shaped ice crystals coincide on the parhelic circle to create a bright spot if this theory is correct anthelia should only appear together with these other haloes however anthelia occur unaccompanied by other plate crystal haloes thus scientists have produced alternative explanations the dutch professor s w visser proposed they form by two exterior light reflections in quadrangular prisms while robert greenler has suggested two interior reflection in column shaped crystals produces the phenomenon while the anthelion area is usually sparse on haloes in a complex display it features various rare optic phenomena flanking the anthelion on the parhelic circle are two 120 ° parhelia and two liljequist parhelia caused by plate crystals the tricker and diffuse arcs are produced in singly oriented column crystals and form an ankh like shape passing through the anthelion wegener arcs occasionally crosses the sky to converge in the anthelion
anthrax is an infection caused by the bacterium bacillus anthracis it can occur in four forms skin inhalation intestinal and injection symptoms begin between one day and two months after contracting the infection the skin form presents with a small blister with surrounding swelling that often turns into a painless ulcer with a black center the inhalation form presents with fever chest pain and shortness of breath the intestinal form presents with nausea vomiting diarrhea or abdominal pain the injection form presents with fever and an abscess at the site of drug injection anthrax is spread by contact with the spores of the bacteria which are often from infectious animal products contact is by breathing eating or through an area of broken skin it does not typically spread directly between people risk factors include people who work with animals or animal products travelers postal workers and military personnel diagnosis can be confirmed based on finding antibodies or the toxin in the blood or by culture of a sample from the infected site anthrax vaccination is recommended for people who are at high risk immunizing animals against anthrax is recommended in areas where previous infections have occurred two months of antibiotics such as doxycycline or ciprofloxacin after exposure can also prevent infection if infection occurs treatment is with antibiotics and possibly antitoxin the type and number of antibiotics used depends on the type of infection antitoxin is recommended for those with widespread infection anthrax among people is most common in africa and central and southern asia it also occurs fairly regularly in southern europe but is uncommon in northern europe and north america globally at least 2 000 cases occur a year with about two cases a year in the united states skin infections represent more than 95 of cases without treatment the risk of death from skin anthrax is 24 for intestinal infection the risk of death is 25 to 75 while in inhaled anthrax despite treatment it is around 50 to 80 until the 20 th century anthrax infections killed hundreds of thousands of people and other animals each year anthrax has been developed as a weapon by a number of countries in plant eating animals infection occurs when they eat or breathe in the spores while grazing carnivores may become infected by eating infected animals
an anthroponotic disease or anthroponosis is an infectious disease in which a disease causing agent carried by humans is transferred to other animals it may cause the same disease or a different disease in other animals since humans do not generally inflict bite wounds on other animals the method of transmissions is always a soft contact such as skin to skin transmission an example is chytridiomycosis which can be spread by humans with the fungus on their skin handling frogs with bare hands the reverse situation a disease transmitted from animals to humans is known as zoonotic it can also be defined as a human to human infection with no animal vector
anthropophobia or anthrophobia literally fear of man from greek άνθρωπος ánthropos man and φόβος phóbos fear also called interpersonal relation phobia or social phobia is pathological fear of people or human company anthropophobia is an extreme pathological form of shyness and timidity being a form of social phobia it may manifest as fears of blushing or meeting others gaze awkwardness and uneasiness when appearing in society etc a specific japanese cultural form is known as taijin kyofusho anthropophobia can be best defined as the fear of people in crowded situations but can also go beyond and leave the person uncomfortable when being around just one person conditions vary depending on the person some cases are mild and can be handled while more serious cases can lead to complete social withdrawal and the exclusive use of written and electronic communication
anti armenian sentiment also known as anti armenianism and armenophobia is a diverse spectrum of negative feelings dislikes fears aversion derision and or prejudice towards armenians armenia and armenian culture modern anti armenianism is usually expressed by opposition to the actions or existence of armenia aggressive denial of the armenian genocide or belief in an armenian conspiracy to fabricate history and manipulate public and political opinion for political gain
anti catholic riots were a phenomenon particularly in the english speaking world which tended to accompany the lifting of legal sanctions against the catholic minority in these countries examples included philadelphia anti catholic riots bath maine anti catholic riot of 1854 gordon riots in london 1969 northern ireland riots
anti french sentiment in the united states is the manifestation of francophobia by americans it signifies a consistent hostility toward the government culture and people of france that employs stereotypes it has a strong relation with inner american political conflicts as french attitudes and status symbols were closely connected with parts of american elites and leaders in some cases anti french sentiment may be driven by xenophobia a general aversion toward foreigners
anti hinduism is a negative perception or religious intolerance against the practice and practitioners of hinduism anti hindu sentiments have been expressed by muslims in pakistan bangladesh malaysia and india leading to significant persecution of hindus in those regions there are also allegations of anti hinduism voiced by members of the hindu diaspora in the west against their host societies notably in the united states where these form part of the so called culture wars with cases such as the california textbook controversy over hindu history
anti nmda n methyl d aspartate receptor encephalitis also termed nmda receptor antibody encephalitis is an acute form of encephalitis that is potentially lethal but has a high probability for recovery with treatment it is caused by an autoimmune reaction primarily against the nr 1 subunit of the nmda receptor different descriptions and syndromal designations for this disease existed in medical literature prior to 2007 but it was then that the disease was officially categorized and named by dr josep dalmau and colleagues movement disorder relapses after herpes simplex virus 1 hsv 1 encephalitis have been hypothesized to be secondary to postviral autoimmunity recently a proportion of patients with hsv 1 encephalitis hse were shown to produce autoantibodies against nmda receptors the condition is associated with tumours mostly teratomas of the ovaries and thus can be considered a paraneoplastic syndrome however there are a substantial number of cases with no detectable tumour and in fact it appears that most patients do not have a tumour
anti russian sentiment or russophobia is a diverse spectrum of negative feelings dislikes fears aversion derision and or prejudice of russia russians and or russian culture a wide variety of mass culture clichés about russia and russians exists many of these stereotypes were developed during the cold war and were used as elements of political war against the soviet union some of these prejudices are still observed in the discussions of the relations with russia negative representation of russia and russians in modern popular culture is also often described as functional as stereotypes about russia may be used for framing reality like creating an image of an enemy or an excuse or an explanation for compensatory reasons decades after the end of the cold war russians are still portrayed as hollywood s go to villains on the other hand russian nationalists and apologists of the politics of russia often use the allegations of russophobia as a form of propaganda to counter the criticism of russia
antianalgesia is the ability of some endogenous chemicals notably cholecystokinin and neuropeptide y to counter the effects of exogenous analgesics such as morphine or endogenous pain inhibiting neurotransmitters modulators such as the endogenous opioids a learned form can be established using methods similar to the learning principle of conditioned inhibition and has been demonstrated in rats
antibiotic candidiasis also known as iatrogenic candidiasis is a candidal infection caused by antibiotic use
in genetics anticipation is a phenomenon whereby as a genetic disorder is passed on to the next generation the symptoms of the genetic disorder become apparent at an earlier age with each generation in most cases an increase of severity of symptoms is also noted anticipation is common in trinucleotide repeat disorders such as huntington s disease and myotonic dystrophy where a dynamic mutation in dna occurs all of these diseases have neurological symptoms prior to the understanding of the genetic mechanism for anticipation it was debated whether anticipation was a true biological phenomenon or whether the earlier age of diagnosis was related to heightened awareness of disease symptoms within a family
anticonvulsant sulfonamide hypersensitivity syndrome is a potentially serious hypersensitivity reaction that can be seen with drugs with an aromatic amine chemical structure such as aromatic anticonvulsants e g diphenylhydantoin phenobarbital phenytoin carbamazepine lamotrigine sulfonamides or other drugs with an aromatic amine procainamide cross reactivity should not occur between drugs with an aromatic amine and drugs without an aromatic amine e g sulfonylureas thiazide diuretics furosemide and acetazolamide therefore these drugs can be safely used in the future the hypersensitivity syndrome is characterized by a skin eruption that is initially morbilliform the rash may also be a severe stevens johnson syndrome or toxic epidermal necrolysis systemic manifestations occur at the time of skin manifestations and include eosinophilia hepatitis and interstitial nephritis however a subgroup of patients may become hypothyroid as part of an autoimmune thyroiditis up to 2 months after the initiation of symptoms this kind of adverse drug reaction is caused by the accumulation of toxic metabolites it is not the result of an ige mediated reaction the risk of first degree relatives ’ developing the same hypersensitivity reaction is higher than in the general population as this syndrome can present secondary to multiple anticonvulsants the general term anticonvulsant hypersensitivity syndrome is favored over the original descriptive term dilantin hypersensitivity syndrome
an anticyclone that is opposite to a cyclone is a weather phenomenon defined by the united states national weather service s glossary as a large scale circulation of winds around a central region of high atmospheric pressure clockwise in the northern hemisphere anti clockwise in the southern hemisphere effects of surface based anticyclones include clearing skies as well as cooler drier air fog can also form overnight within a region of higher pressure mid tropospheric systems such as the subtropical ridge deflect tropical cyclones around their periphery and cause a temperature inversion inhibiting free convection near their center building up surface based haze under their base anticyclones aloft can form within warm core lows such as tropical cyclones due to descending cool air from the backside of upper troughs such as polar highs or from large scale sinking such as the subtropical ridge
antidepressant discontinuation syndrome is a condition that can occur following the interruption dose reduction or discontinuation of antidepressant drugs including selective serotonin re uptake inhibitors ssris or serotonin – norepinephrine reuptake inhibitors snris the symptoms can include flu like symptoms and disturbances in sleep senses movement mood and thinking in most cases symptoms are mild short lived and resolve without treatment more severe cases are often successfully treated by reintroduction of the drug which usually leads to resolution within one day
antidepressant treatment tachyphylaxis adt tachyphylaxis also known as prozac poop out is a medical condition in which progressive or acute tolerance effects are seen following chronic administration of a drug adt tachyphylaxis specifically refers to a sudden decrease in response to selective serotonin reuptake inhibitors ssris which are the most commonly prescribed antidepressants although less commonly prescribed as antidepressants having lost popularity following the introduction of ssris monoamine oxidase inhibitors or maois have also incurred a poop out effect among depressed patients
in mathematics an antihomomorphism is a type of function defined on sets with multiplication that reverses the order of multiplication an antiautomorphism is a bijective antihomomorphism i e an antiisomorphism from a set to itself from being bijective it follows that it has an inverse and that the inverse is also an antiautomorphism
antiphospholipid syndrome or antiphospholipid antibody syndrome aps or apls or often also hughes syndrome is an autoimmune hypercoagulable state caused by antiphospholipid antibodies aps provokes blood clots thrombosis in both arteries and veins as well as pregnancy related complications such as miscarriage stillbirth preterm delivery and severe preeclampsia the diagnostic criteria require one clinical event i e thrombosis or pregnancy complication and two antibody blood tests spaced at least three months apart that confirm the presence of either lupus anticoagulant or anti β 2 glycoprotein i since β 2 glycoprotein i antibodies are a subset of anti cardiolipin antibodies an anti cardiolipin assay can be performed as a less specific proxy antiphospholipid syndrome can be primary or secondary primary antiphospholipid syndrome occurs in the absence of any other related disease secondary antiphospholipid syndrome occurs with other autoimmune diseases such as systemic lupus erythematosus sle in rare cases aps leads to rapid organ failure due to generalised thrombosis this is termed catastrophic antiphospholipid syndrome caps and is associated with a high risk of death antiphospholipid syndrome often requires treatment with anticoagulant medication such as heparin to reduce the risk of further episodes of thrombosis and improve the prognosis of pregnancy warfarin coumadin is not used during pregnancy because it can cross the placenta unlike heparin and is teratogenic
antisocial personality disorder aspd also known as dissocial personality disorder dpd and sociopathy is a personality disorder characterized by a pervasive pattern of disregard for or violation of the rights of others an impoverished moral sense or conscience is often apparent as well as a history of crime legal problems or impulsive and aggressive behavior antisocial personality disorder is the name of the disorder as defined in the diagnostic and statistical manual of mental disorders dsm dissocial personality disorder dpd is the name of a similar or equivalent concept defined in the international statistical classification of diseases and related health problems icd where it states that the diagnosis includes antisocial personality disorder both manuals have similar but not identical criteria for diagnosing the disorder both have also stated that their diagnoses have been referred to or include what is referred to as psychopathy or sociopathy but distinctions have been made between the conceptualizations of antisocial personality disorder and psychopathy with many researchers arguing that psychopathy is a disorder that overlaps with but is distinguishable from aspd
anti synthetase syndrome is a rare medical syndrome associated with interstitial lung disease dermatomyositis and polymyositis and other autoimmune diseases
antithrombin iii deficiency abbreviated atiii deficiency is a deficiency of antithrombin iii it is a rare hereditary disorder that generally comes to light when a patient suffers recurrent venous thrombosis and pulmonary embolism and repetitive intrauterine fetal death iufd inheritance is usually autosomal dominant though a few recessive cases have been noted the disorder was first described by egeberg in 1965 the patients are treated with anticoagulants or more rarely with antithrombin concentrate in kidney failure especially nephrotic syndrome antithrombin is lost in the urine leading to a higher activity of factor ii and factor x and in increased tendency to thrombosis
antley – bixler syndrome also called trapezoidocephaly synostosis syndrome is a rare very severe autosomal recessive congenital disorder characterized by malformations and deformities affecting the majority of the skeleton and other areas of the body
anton – babinski syndrome also known as visual anosognosia is a rare symptom of brain damage occurring in the occipital lobe those who suffer from it are cortically blind but affirm often quite adamantly and in the face of clear evidence of their blindness that they are capable of seeing failing to accept being blind the sufferer dismisses evidence of their condition and employs confabulation to fill in the missing sensory input it is named after gabriel anton and joseph babinski
an antral follicle or secondary follicle is an ovarian follicle during a certain latter stage of folliculogenesis definitions differ in where the shift into an antral follicle occurs in the staging of folliculogenesis with some stating that it occurs when entering the secondary stage and others stating that it occurs when entering the tertiary stage
anxiety aggression driven depression also known as 5 ht related depression is a proposed subtype of major depressive disorder first proposed by the dutch psychiatrist herman m van praag in 1996 van praag has continued to write on this topic in subsequent academic articles
anxiety disorders are a group of mental disorders characterized by feelings of anxiety and fear anxiety is a worry about future events and fear is a reaction to current events these feelings may cause physical symptoms such as a fast heart rate and shakiness there are a number of anxiety disorders including generalized anxiety disorder specific phobia social anxiety disorder separation anxiety disorder agoraphobia and panic disorder the disorder differs by what results in the symptoms people often have more than one anxiety disorder the cause of anxiety disorders is a combination of genetic and environmental factors risk factors include a history of child abuse a family history of mental disorders and poverty they often occur with other mental disorders particularly major depressive disorder personality disorder and substance use disorder to be diagnosed symptoms typically need to be present at least six months be more than would be expected for the situation and decrease functioning other psychiatric and medical problems that may result in similar symptoms including hyperthyroidism heart disease caffeine alcohol or cannabis use and withdrawal from certain drugs without treatment anxiety disorders tend to remain treatment may include lifestyle changes counselling and medications counselling is typically with a type of cognitive behavioural therapy medications such as antidepressants or beta blockers may improve symptoms about 12 of people are affected by an anxiety disorder in a given year they occur about twice as often in females as males and generally begin before the age of 25 the most common are specific phobia which affects nearly 12 and social anxiety disorder which affects 10 at some point in their life they affect those between the ages of 15 and 35 the most and become less common after the age of 55 rates appear to be higher in the united states and europe
an aortic aneurysm is an enlargement dilation of the aorta to greater than 1 5 times normal size they usually cause no symptoms except when ruptured occasionally there may be abdominal back or leg pain they are most commonly located in the abdominal aorta but can also be located in the thoracic aorta aortic aneurysms cause weakness in the wall of the aorta and increase the risk of aortic rupture when rupture occurs massive internal bleeding results and unless treated immediately shock and death can occur screening with ultrasound is indicated in those at high risk prevention is by decreasing risk factors such as smoking treatment is either by open or endovascular surgery aortic aneurysms resulted in about 152 000 deaths in 2013 up from 100 000 in 1990
aortic dissection occurs when a tear in the inside of the aorta causes blood to flow between the layers of the wall of the aorta forcing the layers apart in most cases this is associated with a sudden onset of severe chest or back pain often described as tearing in character there may also be vomiting sweating and lightheadedness other symptoms may result from decreased blood supply to other organs such as stroke or mesenteric ischemia aortic dissection can quickly lead to death as a result of not enough blood flow to the heart or rupture of the aorta aortic dissection is more common in those with a history of high blood pressure a number of connective tissue diseases that affect blood vessel wall strength such as marfan syndrome a bicuspid aortic valve and previous heart surgery major trauma smoking cocaine use pregnancy a thoracic aortic aneurysm inflammation of arteries and abnormal lipid levels also increase the risk the diagnosis is confirmed with medical imaging such as computed tomography magnetic resonance imaging or ultrasound there are two main types stanford type a which involve the first part of the aorta and type b which do not prevention is by blood pressure control and not smoking the treatment of aortic dissection depends on the part of the aorta involved surgery is usually required for dissections that involve the first part of the aorta while those that do not can typically be treated with blood pressure and heart rate lowering unless complications result surgery may be done either by an opening in the chest or by endovascular aneurysm repair carried out from inside the blood vessels aortic dissection is relatively rare occurring at an estimated rate of 3 per 100 000 people every year it is more common in males than females the typical age at diagnosis is 63 with about 10 of cases occurring before 40 without treatment about half of people with type a die within three days and about 10 of people with type b die within a month the first case of aortic dissection described was in the examination of king george ii of great britain following his death in 1760 surgery for aortic dissection was introduced in the 1950 s by michael e debakey
aortic insufficiency ai also known as aortic regurgitation ar is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole from the aorta into the left ventricle as a consequence the cardiac muscle is forced to work harder than normal
central aortic blood pressure cap or casp is the blood pressure at the root of aorta studies have shown the importance of central aortic pressure and its implications in assessing the efficacy of antihypertensive treatment with respect to cardiovascular risk factors the traditional method of measuring blood pressure in the arms has been shown to underestimate the efficacy of drugs such as amlodipine and overestimate the efficacy of those like atenolol a clinical trial demonstrated that different medications for lowering blood pressure have different effects on the central aortic pressure and blood flow characteristics despite producing similar branchial blood pressure readings the study also indicated that the cap is a better independent predictor of cardiovascular and renal outcome
aortic rupture is the rupture or breakage of the aorta the largest artery in the body aortic rupture is a rare extremely dangerous condition the most common cause is an abdominal aortic aneurysm that has ruptured spontaneously aortic rupture is distinct from aortic dissection which is a tear through the inner wall of the aorta that can block the flow of blood through the aorta to the heart or abdominal organs an aortic rupture can be classified according to its cause into one of the following main types traumatic aortic rupture aortic rupture secondary to an aortic aneurysm
aortic stenosis as or aos is the narrowing of the exit of the left ventricle of the heart where the aorta begins such that problems result it may occur at the aortic valve as well as above and below this level it typically gets worse over time symptoms often come on gradually with a decreased ability to exercise often occurring first if heart failure loss of consciousness or heart related chest pain occurs due to as the outcomes are worse loss of consciousness typically occurs with standing or exercise signs of heart failure include shortness of breath especially when lying down at night or with exercise and swelling of the legs thickening of the valve without narrowing is known as aortic sclerosis causes include being born with a bicuspid aortic valve and rheumatic fever a bicuspid aortic valve affects about one to two percent of the population while rheumatic heart disease mostly occurring in the developing world a normal valve however may also harden over the decades risk factors are similar to those of coronary artery disease and include smoking high blood pressure high cholesterol diabetes and being male the aortic valve usually has three leaflets and is located between the left ventricle of the heart and the aorta as typically results in a heart murmur its severity can be divided into mild moderate severe and very severe based on ultrasound of the heart findings aortic stenosis is typically followed using repeated ultrasounds once it has become severe treatment primarily involves valve replacement surgery with transcatheter aortic valve replacement tavr being an option in some who are at high risk from surgery valves may either be mechanical or bioprosthetic with each having risks and benefits another less invasive procedure balloon aortic valvuloplasty bav may result in benefit but this is for only for a few months complications like heart failure may be treated as per normal in those with mild to moderate as in those with severe disease a number of medications should be avoided including ace inhibitors nitroglycerin and some beta blockers nitroprusside or phenylephrine may be used in those with decompensated heart failure depending on the blood pressure aortic stenosis is the most common valvular heart disease in the developed world it affects about 2 of people who are over 65 years of age estimated rates are not known in most of the developing world as of 2014 in those who have symptoms without repair the chance of death at five years is about 50 and at 10 years is about 90 aortic stenosis was first described by french physician lazare rivière in 1663
aortitis is the inflammation of the aortic wall the disorder is potentially life threatening and rare it is reported that there are only 1 – 3 new cases of aortitis per year per million people in the united states and europe aortitis is most common in people 10 to 40 years of age
an aortoenteric fistula is a connection between the aorta and the intestines stomach or esophageus there can be significant blood loss into the intestines resulting in bloody stool and death it is usually secondary to an abdominal aortic aneurysm repair
in medicine aortoiliac occlusive disease also known as leriche s syndrome and leriche syndrome is a form of peripheral artery disease involving the blockage of the abdominal aorta as it transitions into the common iliac arteries
an aortopulmonary septal defect is a group of rare congenital heart disorders that result from errors in the development of the aorticopulmonary septum there are numerous types types include persistent truncus arteriosus double outlet right ventricle transposition of the great vessels tetralogy of fallot
aosaginohi or aosagibi 青鷺火 blue heron fire is a phenomenon illustrated by toriyama sekien in his konjaku gazu zoku hyakki it depicts a night heron with a mysteriously illuminated body folklore built around the phenomenon tells a story of an old black crowned night heron transforming into a yokai the herons feathers fuse into shining scales that give off an iridescent blue light in the dark of night the yokai s breath is also said to release golden powder into the air that collects to form a heat less fiery light though this light eventually dissipates in the wind the harmless creature is said to flee from human contact retaining a normal heron s shyness legend also warns to not confuse the glimmering blue white light with onibi lights
ape hand deformity also known as simian hand is a deformity in humans who cannot move the thumb away from the rest of the hand it is an inability to abduct the thumb abduction of the thumb refers to the specific capacity to orient the thumb perpendicularly to the ventral palmar surface of the hand opposition refers specifically the ability to swing the first metacarpal such that the tip of the thumb may touch the distal end of the 5 th phalanx and if we put the hand on the table as the palm upward the thumb can not point to the sky the ape hand deformity is caused by damage to the proximal median nerve and subsequent loss of opponens pollicis muscle function the name ape hand deformity is misleading as apes have opposable thumbs it can occur with an injury of the median nerve either at the elbow or the wrist impairing the thenar muscles and opponens pollicis muscle ape hand deformity is one aspect of median nerve palsy which is usually caused by deep injuries to the arm forearm and wrist area
apert syndrome is a form of acrocephalosyndactyly a congenital disorder characterized by malformations of the skull face hands and feet it is classified as a branchial arch syndrome affecting the first branchial or pharyngeal arch the precursor of the maxilla and mandible disturbances in the development of the branchial arches in fetal development create lasting and widespread effects in 1906 eugène apert a french physician described nine people sharing similar attributes and characteristics linguistically acro is greek for peak referring to the peaked head that is common in the syndrome cephalo also from greek is a combining form meaning head syndactyly refers to webbing of fingers and toes in embryology the hands and feet have selective cells that die called selective cell death or apoptosis causing separation of the digits in the case of acrocephalosyndactyly selective cell death does not occur and skin and rarely bone between the fingers and toes fuses the cranial bones are affected as well similar to crouzon syndrome and pfeiffer syndrome craniosynostosis occurs when the fetal skull and facial bones fuse too soon in utero disrupting normal bone growth fusion of different sutures leads to different patterns of growth on the skull examples include trigonocephaly fusion of the metopic suture brachycephaly fusion of the coronal suture and lambdoid suture bilaterally dolichocephaly fusion of the sagittal suture plagiocephaly fusion of coronal and lambdoidal sutures unilaterally and oxycephaly or turricephaly fusion of coronal and lambdoid sutures findings for the incidence of the syndrome in the population have varied with estimates as low as 1 birth in 200 000 provided and 160 000 given as an average by older studies a study conducted in 1997 however by the california birth defects monitoring program found an incidence rate of 1 in 80 645 out of almost 2 5 million live births another study conducted in 2002 by the craniofacial center north texas hospital for children found a higher incidence of about 1 in 65 000 live births
in telecommunication aperture to medium coupling loss is the difference between the theoretical antenna gain of a very large antenna such as the antennas in beyond the horizon microwave links and the gain that can be realized in practice note 1 aperture to medium coupling loss is related to the ratio of the scatter angle to the antenna beamwidth note 2 the very large antennas are referred to in wavelengths thus this loss can apply to line of sight systems also
aphakia is the absence of the lens of the eye due to surgical removal a perforating wound or ulcer or congenital anomaly it causes a loss of accommodation far sightedness hyperopia and a deep anterior chamber complications include detachment of the vitreous or retina and glaucoma babies are rarely born with aphakia occurrence most often results from surgery to remove congenital cataracts clouding of the eyes lens which can block light from entering the eye and focusing clearly congenital cataracts usually develop as a result of infection of the fetus or genetic reasons it is often difficult to identify the exact cause of these cataracts especially if only one eye is affected people with aphakia have relatively small pupils and their pupils dilate to a lesser degree
aphalangia is a syndrome with the characteristic absence of the phalanx bone on one or more digits
aphallia is a congenital malformation in which the phallus penis or clitoris is absent it is the female counterpart of penile agenesis and testicular agenesis the word is derived from the greek a for not and phallos for penis it is classified as an intersex condition
aphantasia is the suggested name for a condition where one does not possess a functioning mind s eye and cannot visualize imagery the phenomenon was first described by francis galton in 1880 but remained largely unstudied since interest in the phenomenon renewed after the publication of a study by a team led by prof adam zeman of the university of exeter which also coined the term aphantasia research on the subject is still scarce but further studies are being planned
aphasia is an inability to comprehend and formulate language because of dysfunction in specific brain regions caused either by a cerebral vascular accident cva which is also known as a stroke or head trauma such as with a concussion aphasia can cause impairments in speech and language modalities to be diagnosed with aphasia a person s speech or language must be significantly impaired in one or several of the four communication modalities following acquired brain injury or have significant decline over a short time period progressive aphasia the four communication modalities are auditory comprehension verbal expression reading and writing and functional communication the difficulties of people with aphasia can range from occasional trouble finding words to losing the ability to speak read or write intelligence however is unaffected aphasia also affects visual language such as sign language in contrast the use of formulaic expressions in everyday communication is often preserved one prevalent deficit in the aphasias is anomia which is a deficit in word finding ability the term aphasia implies that one or more communication modalities have been damaged and are therefore functioning incorrectly aphasia does not refer to damage to the brain that results in motor or sensory deficits as it is not related to speech which is the verbal aspect of communicating but rather the individual s language an individual s language is the socially shared set of rules as well as the thought processes that go behind verbalized speech it is not a result of a more peripheral motor or sensory difficulty such as paralysis affecting the speech muscles or a general hearing impairment aphasia is from greek a without phásis φάσις speech the word aphasia comes from the word ἀφασία aphasia in ancient greek which means speechlessness derived from ἄφατος aphatos speechless from ἀ a not un and φημί phemi i speak
in phonetics apheresis əˈfɛrᵻsɪs əˈfɪərᵻsɪs british english aphaeresis is the loss of one or more sounds from the beginning of a word especially the loss of an unstressed vowel thus producing a new form called an aphetism ˈæfɪtɪzᵊm
aphthous stomatitis is a common condition characterized by the repeated formation of benign and non contagious mouth ulcers aphthae in otherwise healthy individuals the informal term canker sores is also used mainly in north america although this may also refer to any mouth ulcer the cause is not completely understood but involves a t cell mediated immune response triggered by a variety of factors different individuals have different triggers which may include nutritional deficiencies local trauma stress hormonal influences allergies genetic predisposition or other factors these ulcers occur periodically and heal completely between attacks in the majority of cases the individual ulcers last about 7 – 10 days and ulceration episodes occur 3 – 6 times per year most appear on the non keratinizing epithelial surfaces in the mouth i e anywhere except the attached gingiva the hard palate and the dorsum of the tongue although the more severe forms which are less common may also involve keratinizing epithelial surfaces symptoms range from a minor nuisance to interfering with eating and drinking the severe forms may be debilitating even causing weight loss due to malnutrition the condition is very common affecting about 20 of the general population to some degree the onset is often during childhood or adolescence and the condition usually lasts for several years before gradually disappearing there is no cure and treatments aim to manage pain reduce healing time and reduce the frequency of episodes of ulceration the term is from from greek αφθα aphtha meaning mouth ulcer
apical dominance is the phenomenon whereby the main central stem of the plant is dominant over i e grows more strongly than other side stems on a branch the main stem of the branch is further dominant over its own side branchlets plant physiology describes apical dominance as the control exerted by the terminal bud and shoot apex over the outgrowth of lateral buds
apicophilicity is the phenomenon in which electronegative substituents of trigonal bipyramidal pentacoordinate compounds prefer to occupy apical positions lap the term apicophilicity was first proposed by earl l muetterties in 1963 for the structural analysis of pentacoordinate phosphorus fluorides by 19 f nmr since the apical bonding of a pentacoordinate typical group 1 2 13 18 element compound consists of a 3 center 4 electron bond in which the electron density is localized on two apical substituents an arrangement in which electronegative substituents occupy apical positions is more stable the apicophilicity of a substituent is defined as the difference in energy between two isomeric structures in which the substituent occupies an apical position and an equatorial position leq experimentally instead of direct measurement of the energy difference which is usually difficult to measure the relative energy barriers for pseudorotation of isomers are used for determination of the apicophilicity scale some experimental and theoretical studies have been made to measure relative apicophilicities for various substituents the apicophilicity of a substituent mainly depends on its electronegativity but some other factors can also have an effect a bulky substituent prefers equatorial positions which are more distant from other substituents a substituent with π bonding ability also prefers equatorial positions the use of multidentate ligands can also control the arrangement of substituents for example a bidentate ligand with a five membered ring structure greatly stabilizes the arrangement in which their two coordination sites occupy an apical and an equatorial position pclf 4 pcl 2 f 3 pcl 3 f 2 pcl 4 f
aplasia from greek a not no plasis molding is defined in general as defective development or congenital absence of an organ or tissue in the field of hematology the term refers to incomplete retarded or defective development or cessation of the usual regenerative process
aplasia cutis congenita also known as cutis aplasia congenital absence of skin and congenital scars is the most common congenital cicatricial alopecia and is a congenital focal absence of epidermis with or without evidence of other layers of the skin it can be associated with johanson blizzard syndrome adams oliver syndrome trisomy 13 and wolf hirschhorn syndrome it can also seen with exposure to methimazole and carbimazole in utero this dermatological manifestation has been linked to peptidase d haploinsufficiency and a deletion in chromosome 19
aplastic anemia is a rare disease in which the bone marrow and the hematopoietic stem cells that reside there are damaged this causes a deficiency of all three blood cell types pancytopenia red blood cells anemia white blood cells leukopenia and platelets thrombocytopenia aplastic refers to inability of the stem cells to generate mature blood cells it is most prevalent in people in their teens and twenties but is also common among the elderly it can be caused by exposure to chemicals drugs radiation immune disease and heredity however in about half the cases the cause is unknown the definitive diagnosis is by bone marrow biopsy normal bone marrow has 30 – 70 blood stem cells but in aplastic anemia these cells are mostly gone and replaced by fat first line treatment for aplastic anemia consists of immunosuppressive drugs typically either anti lymphocyte globulin or anti thymocyte globulin combined with corticosteroids and ciclosporin hematopoietic stem cell transplantation is also used especially for patients under 30 years of age with a related matched marrow donor
apnea of prematurity is defined as cessation of breathing by a premature infant that lasts for more than 20 seconds and or is accompanied by hypoxia or bradycardia apnea is traditionally classified as either obstructive central or mixed obstructive apnea may occur when the infant s neck is hyperflexed or conversely hyperextended it may also occur due to low pharyngeal muscle tone or to inflammation of the soft tissues which can block the flow of air though the pharynx and vocal cords central apnea occurs when there is a lack of respiratory effort this may result from central nervous system immaturity or from the effects of medications or illness many episodes of apnea of prematurity may start as either obstructive or central but then involve elements of both becoming mixed in nature
apneustic respiration a k a apneusis is an abnormal pattern of breathing characterized by deep gasping inspiration with a pause at full inspiration followed by a brief insufficient release accompanying signs and symptoms may include decerebrate posturing fixed dilated pupils coma or profound stupor quadriparesis absent corneal reflex negative oculocephalic reflex and obliteration of the gag reflex
in phonology apocope əˈpɒkəpiː is the loss of one or more sounds from the end of a word and especially the loss of an unstressed vowel
apocrine gland carcinoma is a cutaneous condition characterized by skin lesions which form in the axilla or anogenital regions
an apocrine nevus is an extremely rare cutaneous condition that is composed of hyperplastic mature apocrine glands
apolipoprotein b deficiency also known as familial defective apolipoprotein b 100 is an autosomal dominant disorder resulting from a missense mutation which reduces the affinity of apob 100 for the low density lipoprotein receptor ldl receptor see native ldl apob structure at 37 ° c on youtube this causes impairments in ldl catabolism resulting in increased levels of low density lipoprotein in the blood the clinical manifestations are similar to diseases produced by mutations of the ldl receptor such as familial hypercholesterolemia treatment may include niacin or statin or ezetimibe it is also known as normotriglyceridemic hypobetalipoproteinemia
apolysis ancient greek ἀπόλυσις discharge lit absolution is the separation of the cuticula from the epidermis in arthropods and related groups ecdysozoa since the cuticula of these animals is also the skeletal support of the body and is inelastic it is shed during growth and a new covering of larger dimensions is formed during this process an arthropod becomes dormant for a period of time enzymes are secreted to digest the inner layers of the existing cuticle detaching the animal from the outer cuticle this allows the new cuticle to develop without being exposed to the environmental elements after apolysis ecdysis occurs ecdysis is the actual emergence of the arthropod into the environment and always occurs directly after apolysis the newly emerged animal then hardens and continues its life
an aporime is a problem difficult to resolve and which has never been resolved though it may not be in itself impossible the word is derived from the greek ἄπορον which signifies something very difficult and impracticable being formed from the privative α and πόρος passage when a question was proposed to any of the ancient greek philosophers especially of the sect of academists if he could not give a solution his answer was ἀποροῶ q d i do not conceive it i cannot see through it i am not able to clear it up
aposthia is a rare congenital condition in humans in which the foreskin of the penis is missing toward the end of the nineteenth century e s talbot claimed in medicine that aposthia among jews was evidence for the now discredited lamarckian theory of evolution in his work the variation of animals and plants under domestication charles darwin also mentioned cases of born circumcised babies as conclusive evidence for the now discredited blending inheritance it is likely that the cases he described were actually hypospadias a condition in which the urinary meatus is on the underside of the penis neither condition has been shown to have a higher frequency in jews or muslims
apotemnophilia is a neurological disorder characterized by the intense and long standing desire for amputation of a specific limb or a need to become paralyzed blind or deaf another more recent term for it is body integrity identity disorder biid in which otherwise sane and rational individuals express a strong and specific desire for the amputation of a healthy limb or limbs apotemnophilia has features in common with somatoparaphrenia some apotemnophiles seek surgeons to perform an amputation or purposefully injure a limb in order to force emergency medical amputation a separate definition of apotemnophilia is erotic interest in being or looking like an amputee this separate definition should not be confused with acrotomophilia which is the erotic interest in people who are amputees apotemnophilia was first described in a 1977 article by psychologists gregg furth and john money apotemnophilia two cases of self demand amputation as paraphilia more recently 2008 v s ramachandran david brang and paul d mcgeoch have proposed that it is a neurological disorder caused by an incomplete body image map in the right parietal lobe however the notion of a body image map localized to one area of the brain is not supported by contemporary neuroscience the parietal cortex has widely distributed functional neuronal networks and the prospect that the body image in the brain could be localized to some specific cerebral location has not stood the test of time with our changing views of neural activity and integration from the neuroanatomical point of view there can be no strict localization of the perceived body the study carried out david brang paul mcgeoch and v s ramachandran in 2008 was only able to work with two subjects in 2011 paul mcgeoch et al published the results of an experiment in which they were able to obtain meg images of the parietal lobes for four research subjects three of whom desired amputation mcgeoch and his co researchers concluded that the images suggest that inadequate activation of the right superior parietal lobe spl leads to the unnatural situation in which the sufferers can feel the limb in question being touched without it actually incorporating into their body image with a resulting desire for amputation michael first a psychiatrist at columbia university has pointed out that the theory advanced by ramachandran and his colleagues fails to account for the fact that people who desire amputation of a limb sometimes change their preference as to which limb they would like to have amputated in 2011 a group of researchers at the university of southern california brain and creativity institute proposed an alternative hypothesis these researchers proposed that individuals with biid may have a discrepancy between the commands from the motor cortex to the parietal lobe and from the sensory feedback to the same regions in the parietal lobe this theory was based on the discovery that individuals who desire amputation sometimes experience phantom limbs after amputation
apparent leukonychia is a cutaneous condition characterized by white discoloration of the nail that fades with pressure
apparent life threatening events alte also known as a brief resolved unexplained event brue is when a baby for less than a minute has one or more of bluish skin poor breathing weakness or poor responsiveness by the time they are assessed in a healthcare environment they must be back to normal
apparent mineralocorticoid excess ame is an autosomal recessive disorder causing hypertension high blood pressure and hypokalemia abnormally low levels of potassium the condition responds to glucocorticoid treatment it results from mutations in the hsd 11 b 2 gene which encodes the kidney isozyme of 11 β hydroxysteroid dehydrogenase type 2 in an unaffected individual this isozyme inactivates circulating cortisol to the less active metabolite cortisone the inactivating mutation leads to elevated local concentrations of cortisol in the kidney cortisol at high concentrations can cross react and activate the mineralocorticoid receptor leading to aldosterone like effects in the kidney this is what causes the hypokalemia hypertension and hypernatremia associated with the syndrome other conditions such as liddle s syndrome can mimic the clinical features of ame so diagnosis can be made by calculating the ratio of free urinary cortisol to free urinary cortisone since ame patients create less cortisone the ratio will much be higher than non affected patients alternatively one could differentiate between the two syndromes by administering a potassium sparing diuretic patients with liddle s syndrome will only respond to a diuretic that binds the enac channel whereas those with ame will respond to a diuretic that binds to enac or the mineralcorticoid receptor ame is exceedingly rare with fewer than 100 cases recorded worldwide liquorice consumption may also cause a temporary form of ame due to its ability to block 11 β hydroxysteroid dehydrogenase type 2 in turn causing increased levels of cortisol cessation of licorice consumption will reverse this form of ame
in freshwater or marine systems apparent oxygen utilisation aou is the difference between the measured dissolved oxygen concentration and its equilibrium saturation concentration in water with the same physical and chemical properties such differences typically occur when biological activity acts to change the ambient concentration of oxygen for example primary production liberates oxygen and increases its concentration while respiration consumes it and decreases its concentration consequently the aou of a water sample represents the sum of the biological activity that the sample has experienced since it was last in equilibrium with the atmosphere in shallow water systems e g lakes the full water column is generally in close contact with the atmosphere so oxygen concentrations are typically close to saturation aou values are low in deep water systems e g oceans water can be out of contact with the atmosphere for extremely long periods of time years decades centuries and large aou values are possible
appeal to motive is a pattern of argument which consists in challenging a thesis by calling into question the motives of its proposer it can be considered as a special case of the ad hominem circumstantial argument as such this type of argument may be an informal fallacy a common feature of appeals to motive is that only the possibility of a motive however small is shown without showing the motive actually existed or if the motive did exist that the motive played a role in forming the argument and its conclusion indeed it is often assumed that the mere possibility of motive is evidence enough
the appel reaction is an organic reaction that converts an alcohol into an alkyl chloride using triphenylphosphine and carbon tetrachloride the use of carbon tetrabromide or bromine as a halide source will yield alkyl bromides whereas using carbon tetraiodide methyl iodide or iodine gives alkyl iodides the reaction is credited to and named after rolf appel it had however been described earlier the use of this reaction is becoming less common due to carbon tetrachloride being restricted under the montreal protocol the appel reaction drawbacks to the reaction are the use of toxic halogenating agents and the coproduction of organophosphorus product that must be separated from the organic product the phosphorus reagent can be used in catalytic quantities the corresponding alkyl bromide can also be synthesised by addition of lithium bromide as a source of bromide ions catalytic appel reaction scheme
appendicitis is inflammation of the appendix appendicitis commonly presents with right lower abdominal pain nausea vomiting and decreased appetite however approximately 40 of people do not have these typical signs and symptoms severe complications of a ruptured appendix include widespread painful inflammation of the inner lining of the abdominal wall and sepsis appendicitis is caused by a blockage of the hollow portion of the appendix most commonly by a calcified stone made of feces inflamed lymphoid tissue from a viral infection parasites gallstone or tumors may also cause the blockage this blockage leads to increased pressures in the appendix decreased blood flow to the tissues of the appendix and bacterial growth inside the appendix causing inflammation the combination of inflammation reduced blood flow to the appendix and distention of the appendix causes tissue injury and tissue death if this process is left untreated the appendix may burst releasing bacteria into the abdominal cavity leading to severe abdominal pain and increased complications the diagnosis of appendicitis is largely based on the person s signs and symptoms in cases where the diagnosis cannot be made based on the person s history and physical exam close observation radiographic imaging and laboratory tests can be helpful the two most common imaging tests used are ultrasound and computed tomography ct scan ct scan has been shown to be more accurate than ultrasound in detecting acute appendicitis however ultrasound may be preferred as the first imaging test in children and pregnant women because of the risks associated with radiation exposure from ct scans the standard treatment for acute appendicitis is surgical removal of the appendix this may be done by an open incision in the abdomen laparotomy or through a few smaller incisions with the help of cameras laparoscopy surgery decreases the risk of side effects or death associated with rupture of the appendix antibiotics may be equally effective in certain cases of non ruptured appendicitis it is one of the most common and significant causes of severe abdominal pain that comes on quickly worldwide in 2013 about 16 million cases of appendicitis occurred this resulted in 72 000 deaths globally in the united states appendicitis is the most common cause of acute abdominal pain requiring surgery each year in the united states more than 300 000 people with appendicitis have their appendix surgically removed reginald fitz is credited with being the first person to describe the condition in a paper published in 1886
appendix cancer or appendiceal cancers are rare malignancies of the vermiform appendix gastrointestinal stromal tumors are rare tumors with malignant potential primary lymphomas can occur in the appendix breast cancer colon cancer and tumors of the female genital tract may metastasize to the appendix
appetite is the desire to eat food sometimes due to hunger appealing foods can stimulate appetite even when hunger is absent appetite exists in all higher life forms and serves to regulate adequate energy intake to maintain metabolic needs it is regulated by a close interplay between the digestive tract adipose tissue and the brain appetite has a relationship with every individual s behavior appetitive and consummatory behaviours are the only processes that involve energy intake whereas all other behaviours affect the release of energy when stressed appetite levels may increase and result in an increase of food intake decreased desire to eat is termed anorexia while polyphagia or hyperphagia is increased eating dysregulation of appetite contributes to anorexia nervosa bulimia nervosa cachexia overeating and binge eating disorder
an apple doll is a north american cultural phenomenon where the doll s head is made from dried apples the apple is peeled then carved with the facial features of the doll next the apple is left to dry for several days or weeks when completely dry the apple is positioned on the top of a wire frame which is shaped into the rest of the doll s body the rest of the wire frame is covered up by the doll s clothing which is usually sewn by hand in modern times apple dolls are mostly used as decorations or to display craftsmanship rather than as children s toys because of the different effects drying produces no two dolls are alike
apple scab is a disease of malus trees such as apple trees caused by the ascomycete fungus venturia inaequalis the disease manifests as dull black or grey brown lesions on the surface of tree leaves buds or fruits lesions may also appear less frequently on the woody tissues of the tree fruits and the undersides of leaves are especially susceptible the disease rarely kills its host but can significantly reduce fruit yields and fruit quality affected fruits are less marketable due to the presence of the black fungal lesions
applied ecology is a subfield within ecology which considers the application of the science of ecology to real world usually management questions it is an integrated treatment of the ecological social and biotechnological aspects of natural resource conservation and management it is also called ecological or environmental technology applied ecology typically focuses on geomorphology soils and plant communities as the underpinnings for vegetation and wildlife both game and non game management aspects of applied ecology include agro ecosystem management biodiversity conservation biotechnology conservation biology ecosystem restoration habitat management invasive species management protected areas management rangeland management restoration ecology major journals in the field include journal of applied ecology ecological applications applied ecology and environmental research related organizations include institute for applied ecology usa kazakh agency of applied ecology öko institut institute for applied ecology in germany
in mathematics and computer science apply is a function that applies functions to arguments it is central to programming languages derived from lambda calculus such as lisp and scheme and also in functional languages it has a role in the study of the denotational semantics of computer programs because it is a continuous function on complete partial orders apply is also a continuous function in homotopy theory and indeed underpins the entire theory it allows a homotopy deformation to be viewed as a continuous path in the space of functions likewise valid mutations refactorings of computer programs can be seen as those that are continuous in the scott topology the most general setting for apply is in category theory where it is right adjoint to currying in closed monoidal categories a special case of this are the cartesian closed categories whose internal language is simply typed lambda calculus
apraxia is a motor disorder caused by damage to the brain specifically the posterior parietal cortex in which the individual has difficulty with the motor planning to perform tasks or movements when asked provided that the request or command is understood and he she is willing to perform the task a person with apraxia cannot move his or her lips or tongue to the right place to say sounds correctly because even though the muscles are not weak the messages from the brain to the mouth are disrupted the nature of the brain damage determines the severity
apraxia of speech aos is an acquired oral motor speech disorder affecting an individual s ability to translate conscious speech plans into motor plans which results in limited and difficult speech ability by the definition of apraxia aos affects volitional willful or purposeful movement patterns however aos usually also affects automatic speech individuals with aos have difficulty connecting speech messages from the brain to the mouth aos is a loss of prior speech ability resulting from a brain injury such as a stroke or progressive illness developmental verbal dyspraxia dvd also known as childhood apraxia of speech cas and developmental apraxia of speech das is an inability to utilize motor planning to perform movements necessary for speech during a child s language learning process although the causes differ between aos and dvd the main characteristics and treatments are similar
aprosodia is a neurological condition characterized by the inability of a person to properly convey or interpret emotional prosody prosody in language refers to the ranges of rhythm pitch stress intonation etc these neurological deficits can be the result of damage of some form to the non dominant hemisphere areas of language production the prevalence of aprosodias in individuals is currently unknown as testing for aprosodia secondary to other brain injury is only a recent occurrence
aptery is the anatomical condition of an animal completely lacking any kind of wings an animal with this condition is said to be apterous most animal species belong to and are phylogenetic descendants of apterous taxa these groups are said to be primarily apterous apterous animals which belong to or are phylogenetic descendants of winged taxa are said to be secondarily apterous
in pathology an apudoma is an endocrine tumour that arises from an apud cell from structures such as the ampulla of vater they are derived from neural crest cells the term dates back to at least 1975 because the label apudoma is very general it is preferred to use a more specific term when possible
aquadynia is a variant of aquagenic pruritus and characterized by a widespread burning pain that lasts 15 to 45 minutes after water exposure
aquagenic pruritus is a skin condition characterized by the development of severe intense prickling like epidermal itching without observable skin lesions and evoked by contact with water
aquagenic urticaria also known as water allergy and water urticaria is a rarely diagnosed form of physical urticaria the defining symptom is a painful skin reaction resulting from contact with water it is sometimes described as an allergy although it is not a true histamine releasing allergic reaction like other forms of urticaria this seems to not be affected by different temperatures of water such as cold or hot or chemicals such as fluorine and chlorine since it is reproduced with distilled water and medical saline
aquarium granuloma also known as fish tank granuloma and swimming pool granuloma is a skin condition caused by mycobacterium marinum characterized by a skin lesion that presents roughly three weeks after exposure
aqueductal stenosis is a narrowing of the aqueduct of sylvius which blocks the flow of cerebrospinal fluid csf in the ventricular system blockage of the aqueduct can lead to hydrocephalus specifically as a common cause of congenital and or obstructive hydrocephalus the aqueduct of sylvius is the channel which connects the third ventricle to the fourth ventricle and is the narrowest part of the csf pathway with a mean cross sectional area of 0 5 mm 2 in children and 0 8 mm 2 in adults because of its small size the aqueduct is the most likely place for a blockage of csf in the ventricular system this blockage causes ventricle volume to increase because the csf cannot flow out of the ventricles and cannot be effectively absorbed by the surrounding tissue of the ventricles increased volume of the ventricles will result in higher pressure within the ventricles and cause higher pressure in the cortex from it being pushed into the skull a person may have aqueductal stenosis for years without any symptoms and a head trauma hemorrhage or infection could suddenly invoke those symptoms and worsen the blockage
arachnodactyly spider fingers or achromachia is a condition in which the fingers and toes are abnormally long and slender in comparison to the palm of the hand and arch of the foot also the individual s thumbs tend to also be pulled inwards towards the palm it can be present at birth or develop in later life
arachnoid cysts are cerebrospinal fluid covered by arachnoidal cells and collagen that may develop between the surface of the brain and the cranial base or on the arachnoid membrane one of the three membranes that cover the brain and the spinal cord arachnoid cysts are a congenital disorder and most cases begin during infancy however onset may be delayed until adolescence
arachnoiditis is an inflammatory condition of the arachnoid mater or arachnoid one of the membranes known as meninges that surround and protect the nerves of the central nervous system including the brain and spinal cord the arachnoid can become inflamed because of adverse reactions to chemicals infection from bacteria or viruses as the result of direct injury to the spine chronic compression of spinal nerves complications from spinal surgery or other invasive spinal procedures or the accidental intrathecal injection of steroids intended for the epidural space inflammation can sometimes lead to the formation of scar tissue and adhesion that can make the spinal nerves stick together a condition where such tissue develops in and between the leptomeninges the condition can be extremely painful especially when progressing to adhesive arachnoiditis another form of the condition is arachnoiditis ossificans in which the arachnoid becomes ossified or turns to bone and is thought to be a late stage complication of the adhesive form of arachnoiditis
arachnophobia or arachnephobia is a specific phobia the fear of spiders and other arachnids such as scorpions the word is from from greek ἀράχνη aráchnē meaning spider and φόβος phóbos meaning fear
arago s rotations is an observable phenomenon and effect discovered by françois arago in 1824 in the effect as a copper disc is rotated in its own plane and if a magnetic needle be freely suspended on a pivot over the disc the needle will rotate with the disc on the other hand if the needle is fixed it will tend to retard the motion of the disc
arakawa s syndrome ii is an autosomal dominant metabolic disorder that causes a deficiency of the enzyme tetrahydrofolate methyltransferase affected individuals cannot properly metabolize methylcobalamin a type of vitamin b 12 it is also called methionine synthase deficiency tetrahydrofolate methyltransferase deficiency syndrome and n 5 methylhomocysteine transferase deficiency
arbovirus is a term used to refer to a group of viruses that are transmitted by arthropod vectors the word arbovirus is an acronym arthropod borne virus symptoms of arbovirus infection generally occur 3 – 15 days after exposure to the virus and last 3 or 4 days the most common clinical features of infection are fever headache and malaise but encephalitis and hemorrhagic fever may also occur the word tibovirus tick borne virus is sometimes used to describe viruses transmitted by ticks a superorder within the arthropods
arbovirus encephalitis refers to encephalitis that is caused by arbovirus infection there are many types of arboviral encephalitides found in the united states examples include california encephalitis japanese encephalitis st louis encephalitis tick borne encephalitis west nile fever murray valley encephalitis
an arcanobacterium haemolyticum infection is any of several types of infection with the gram positive bacillus arcanobacterium haemolyticum it can cause an acute pharyngitis and it may cause an exanthem characterized by an erythematous morbilliform or scarlatiniform eruption involving the trunk and extremities
architectural design optimization ado is a subfield of engineering that uses optimization methods to study aid and solve architectural design problems such as optimal floorplan layout design optimal circulation paths between rooms and the like
an archive is an accumulation of historical records or the physical place they are located archives contain primary source documents that have accumulated over the course of an individual or organization s lifetime and are kept to show the function of that person or organization professional archivists and historians generally understand archives to be records that have been naturally and necessarily generated as a product of regular legal commercial administrative or social activities they have been metaphorically defined as the secretions of an organism and are distinguished from documents that have been consciously written or created to communicate a particular message to posterity in general archives consist of records that have been selected for permanent or long term preservation on grounds of their enduring cultural historical or evidentiary value archival records are normally unpublished and almost always unique unlike books or magazines for which many identical copies exist this means that archives are quite distinct from libraries with regard to their functions and organization although archival collections can often be found within library buildings a person who works in archives is called an archivist the study and practice of organizing preserving and providing access to information and materials in archives is called archival science the physical place of storage can be referred to as an archive more usual in the uk an archives more usual in the usa or a repository when referring to historical records or the places they are kept the plural form archives is chiefly used the computing use of the term archive should not be confused with the record keeping meaning of the term
the arctic dipole anomaly is a pressure pattern characterized by high pressure on the arctic regions of north america and a low pressure on the eurasia region this pattern sometimes replaces the arctic oscillation and the north atlantic oscillation it was observed for the first time in the first decade of 2000 s and is perhaps linked to recent climate change the arctic dipole lets more southern winds into the arctic ocean resulting in more ice melting the summer 2007 event played an important role in the record low sea ice extent which was recorded in september the arctic dipole has also been linked to changes in arctic circulation patterns that cause drier winters in northern europe but much wetter winters in southern europe and colder winters in east asia europe and the eastern half of north america
arctic haze is the phenomenon of a visible reddish brown springtime haze in the atmosphere at high latitudes in the arctic due to anthropogenic air pollution a major distinguishing factor of arctic haze is the ability of its chemical ingredients to persist in the atmosphere for an extended period of time compared to other pollutants due to limited amounts of snow rain or turbulent air to displace pollutants from the polar air mass in spring arctic haze can linger for more than a month in the northern atmosphere
arctic sea ice decline is the sea ice loss observed in recent decades in the arctic ocean the intergovernmental panel on climate change ipcc fourth assessment report states that greenhouse gas forcing is largely but not wholly responsible for the decline in arctic sea ice extent a study from 2011 suggested that internal variability enhanced the greenhouse gas forced sea ice decline over the last decades a study from 2007 found the decline to be faster than forecasted by model simulations the ipcc fifth assessment report concluded with high confidence that sea ice continues to decrease in extent and that there is robust evidence for the downward trend in arctic summer sea ice extent since 1979 it has been established that the region is at its warmest for at least 40 000 years and the arctic wide melt season has lengthened at a rate of 5 days per decade from 1979 to 2013 dominated by a later autumn freezeup sea ice changes have been identified as a mechanism for polar amplification
the arcuate uterus is a form of a uterine anomaly or variation where the uterine cavity displays a concave contour towards the fundus normally the uterine cavity is straight or convex towards the fundus on anterior posterior imaging but in the arcuate uterus the myometrium of the fundus dips into the cavity and may form a small septation the distinction between an arcuate uterus and a septate uterus is not standardized
arcus senilis or arcus senilis corneae is a white grey or blue opaque ring in the corneal margin peripheral corneal opacity or white ring in front of the periphery of the iris it is present at birth but then fades however it is quite commonly present in the elderly it can also appear earlier in life as a result of hypercholesterolemia arcus senilis can be confused with the limbus sign which reflects calcium rather than lipid deposits
ardalan – shoja – kiuru syndrome is a clinical syndrome featuring hereditary gelsolin amyloidosis and retinitis pigmentosa this syndrome was first recognized by two iranian physicians mohammad ardalan and mohammadali shoja and finnish neurologist sari kiuru enari in an iranian family hereditary gelsolin amyloidosis has originally been reported by finnish ophthalmologist jouko meretoja and is known as meretoja syndrome or familial amyloidosis finnish type in addition to the classic manifestations of finnish type familial amyloidosis cutis laxa progressive peripheral neuropathy and corneal lattice dystrophy some of the afflicted members of the iranian family have retinitis pigmentosa this feature had not been previously reported with this type of amyloidosis ardalan – shoja – kiuru syndrome or hereditary gelsolin amyloidosis plus retintis pigmentosa has not been found outside this single iranian family
ardclough sedition case was a complaint and threat of prosecution leveled against “ nora j murray ” 1888 – 1955 an irish poet and school teacher during the revolutionary period
one athlete from argentina competed at the 1908 summer olympics in london england it was the second appearance of the nation as another argentinian athlete had previously competed at the 1900 summer olympics
argentine hemorrhagic fever ahf or o higgins disease also known in argentina as mal de los rastrojos stubble disease is a hemorrhagic fever and zoonotic infectious disease occurring in argentina it is caused by the junín virus an arenavirus closely related to the machupo virus causative agent of bolivian hemorrhagic fever its vector is a species of rodent the corn mouse
argillic alteration is hydrothermal alteration of wall rock which introduces clay minerals including kaolinite smectite and illite the process generally occurs at low temperatures and may occur in atmospheric conditions argillic alteration is representative of supergene environments where low temperature groundwater becomes acidic argillic assemblages include kaolinite replacing plagioclase and montmorillonite replacing amphibole and plagioclase orthoclase is generally stable and unaffected argillic grades into phyllic alteration at higher temperatures in an ore deposit hydrothermal system advanced argillic alteration occurs under lower ph and higher temperature conditions kaolinite and dickite occur at lower temperatures whereas pyrophyllite and andalusite occur under high temperature conditions t 300 ° c quartz deposition is common alunite topaz zunyite tourmaline enargite and tennantite may also occur greisen alteration is similar
argininemia also called arginase deficiency is an autosomal recessive urea cycle disorder where a deficiency of the enzyme arginase causes a buildup of arginine and ammonia in the blood ammonia which is formed when proteins are broken down in the body is toxic if levels become too high the nervous system is especially sensitive to the effects of excess ammonia
argininosuccinic aciduria also called argininosuccinic acidemia is an inherited disorder that causes the accumulation of argininosuccinic acid also known as asa in the blood and urine some patients may also have an elevation of ammonia a toxic chemical which can affect the nervous system argininosuccinic aciduria may become evident in the first few days of life because of high blood ammonia or later in life presenting with sparse or brittle hair developmental delay and tremors an infant with argininosuccinic aciduria may seem lethargic or be unwilling to eat have poorly controlled breathing rate or body temperature experience seizures or unusual body movements or go into a coma complications from argininosuccinic aciduria may include developmental delay and mental retardation progressive liver damage skin lesions and brittle hair may also be seen immediate treatment and lifelong management following a strict diet and using appropriate supplements may prevent many of these complications occasionally an individual may inherit a mild form of the disorder in which ammonia accumulates in the bloodstream only during periods of illness or other stress
argon 2 is a key derivation function that was selected as the winner of the password hashing competition in july 2015 it was designed by alex biryukov daniel dinu and dmitry khovratovich from university of luxembourg argon 2 is released under a creative commons cc 0 license and provides two related versions argon 2 d maximizes resistance to gpu cracking attacks argon 2 i is optimized to resist side channel attacks both allow specification by three parameters that control execution time memory required degree of parallelism
in mathematics arg is a function operating on complex numbers visualized in a complex plane it gives the angle between the positive real axis to the line joining the point to the origin shown as φ in figure 1 known as an argument of the point
argyll robertson pupils ar pupils or colloquially prostitute s pupils are bilateral small pupils that reduce in size on a near object i e they accommodate but do not constrict when exposed to bright light i e they do not react to light they are a highly specific sign of neurosyphilis however argyll robertson pupils may also be a sign of diabetic neuropathy in general pupils that accommodate but do not react are said to show light near dissociation i e it is the absence of a miotic reaction to light both direct and consensual with the preservation of a miotic reaction to near stimulus accommodation convergence ar pupils are extremely uncommon in the developed world there is continued interest in the underlying pathophysiology but the scarcity of cases makes ongoing research difficult
argyria or argyrosis from ancient greek ἄργυρος argyros silver is a condition caused by inappropriate exposure to chemical compounds of the element silver or to silver dust the most dramatic symptom of argyria is that the skin turns blue or bluish grey it may take the form of generalized argyria or local argyria generalized argyria affects large areas over much of the visible surface of the body local argyria shows in limited regions of the body such as patches of skin parts of the mucous membrane or the conjunctiva the terms argyria and argyrosis have long been used interchangeably with argyria being used more frequently argyrosis has been used particularly in referring to argyria of the conjunctiva but the usage has never been consistent and cannot be relied on except where it has been explicitly specified
in number theory the lagarias arithmetic derivative or number derivative is a function defined for integers based on prime factorization by analogy with the product rule for the derivative of a function that is used in mathematical analysis remark there are many versions of arithmetic derivatives there are the ones as in this article lagarias arithmetic derivative ihara s arithmetic derivative and buium s arithmetic derivatives
the term arithmetic underflow or floating point underflow or just underflow is a condition in a computer program where the result of a calculation is a number of smaller absolute value than the computer can actually store in memory arithmetic underflow can occur when the true result of a floating point operation is smaller in magnitude that is closer to zero than the smallest value representable as a normal floating point number in the target datatype underflow can in part be regarded as negative overflow of the exponent of the floating point value for example if the exponent part can represent values from − 128 to 127 then a result with a value less than − 128 may cause underflow
in mathematics the arithmetic zeta function is a zeta function associated with a scheme of finite type over integers the arithmetic zeta function generalizes the riemann zeta function and dedekind zeta function to higher dimensions the arithmetic zeta function is one of the most fundamental objects of number theory
arithmomania is a mental disorder that may be seen as an expression of obsessive – compulsive disorder ocd individuals suffering from this disorder have a strong need to count their actions or objects in their surroundings sufferers may for instance feel compelled to count the steps while ascending or descending a flight of stairs or to count the number of letters in words they often feel it is necessary to perform an action a certain number of times to prevent alleged calamities other examples include counting tiles on the floor or ceiling the number of lines on the highway or simply the number of times one breathes or blinks or touching things a certain number of times such as a door knob or a table arithmomania sometimes develops into a complex system in which the sufferer assigns values or numbers to people objects and events in order to deduce their coherence counting may be done aloud or in thought
the arm s length principle alp is the condition or the fact that the parties to a transaction are independent and on an equal footing such a transaction is known as an arm s length transaction it is used specifically in contract law to arrange an agreement that will stand up to legal scrutiny even though the parties may have shared interests e g employer employee or are too closely related to be seen as completely independent e g the parties have familial ties it is also one of the key elements in international taxation as it allows to an adequate allocation of profit taxation rights among countries that conclude double tax conventions through transfer pricing among each other transfer pricing and the arm s length principle was one of the focal points of the base erosion and profit shifting beps project developed by the oecd and endorsed by the g 20
in the racial anthropology of the early 20 th century the armenoid type is a subtype of the caucasian race according to anthropologist carleton coon the countries of the northern part of western asia namely anatolia the caucasus iran and the levant were considered the center of distribution of the armenoid race
in applied mathematics arnold diffusion is the phenomenon of instability of integrable hamiltonian systems the phenomenon is named after vladimir arnold who was the first to publish a result in the field in 1964 more precisely arnold diffusion refers to results asserting the existence of solutions to nearly integrable hamiltonian systems that exhibit a significant change in the action variables
chiari malformation also known as arnold – chiari malformation is a malformation of the skull it consists of a downward displacement of the cerebellar tonsils through the foramen magnum the opening at the base of the skull sometimes causing non communicating hydrocephalus as a result of obstruction of cerebrospinal fluid csf outflow the cerebrospinal fluid outflow is caused by phase difference in outflow and influx of blood in the vasculature of the brain it can cause headaches fatigue muscle weakness difficulty swallowing sometimes accompanied by gagging choking and vomiting dizziness nausea tinnitus impaired coordination neck pain unsteady gait problems with balance poor hand coordination fine motor skills numbness and tingling of the hands and feet and speech problems such as hoarseness less often people with chiari malformation may experience ringing or buzzing in the ears tinnitus weakness slow heart rhythm curvature of the spine scoliosis related to spinal cord impairment abnormal breathing such as central sleep apnea characterized by periods of breathing cessation during sleep and in severe cases paralysis
aromatase deficiency is a condition resulting from insufficient production of the enzyme aromatase which can result in inappropriate virilization of female fetuses and delayed puberty as well as inappropriate virilization of the mother during pregnancy
aromatase excess syndrome aes or aexs also sometimes referred to as familial hyperestrogenism or familial gynecomastia is a rare genetic and endocrine syndrome which is characterized by an overexpression of aromatase the enzyme responsible for the biosynthesis of the estrogen sex hormones from the androgens in turn resulting in excessive levels of circulating estrogens and accordingly symptoms of hyperestrogenism it affects both sexes manifesting itself in males as marked or complete phenotypical feminization with the exception of the genitalia i e no pseudohermaphroditism in whom it fits the definition of a form of intersex and in females as hyperfeminization to date 30 males and 8 females among 15 and 7 families respectively have been described in the medical literature
an aromatic ring current is an effect observed in aromatic molecules such as benzene and naphthalene if a magnetic field is directed perpendicular to the plane of the aromatic system a ring current is induced in the delocalized π electrons of the aromatic ring this is a direct consequence of ampère s law since the electrons involved are free to circulate rather than being localized in bonds as they would be in most non aromatic molecules they respond much more strongly to the magnetic field aromatic ring currents are relevant to nmr spectroscopy as they dramatically influence the chemical shifts of 1 h nuclei in aromatic molecules the effect helps distinguish these nuclear environments and is therefore of great use in molecular structure determination in benzene the ring protons experience deshielding because the induced magnetic field has the same direction as the external field and their chemical shift is 7 3 ppm compared to 5 6 to the vinylic proton in cyclohexene in contrast any proton inside the aromatic ring experiences shielding because both fields are in opposite direction this effect can be observed in cyclooctadecanonaene 18 annulene with 6 inner protons at − 3 ppm the situation is reversed in antiaromatic compounds in the dianion of 18 annulene the inner protons are strongly deshielded at 20 8 ppm and 29 5 ppm with the outer protons significantly shielded with respect to the reference at − 1 1 ppm hence a diamagnetic ring current or diatropic ring current is associated with aromaticity whereas a paratropic ring current signals antiaromaticity a similar effect is observed in three dimensional fullerenes in this case it is called a sphere current
aromatic sulfonation is an organic reaction in which a hydrogen atom on an arene is replaced by a sulfonic acid functional group in an electrophilic aromatic substitution aryl sulfonic acids are used as detergents dye and drugs
arrhinia əˈrɪniə or əˈraɪniə also called nasal agenesis is the congenital partial or complete absence of the nose at birth it is an extremely rare condition with few reported cases in the history of modern medicine it is generally classified as a craniofacial abnormality
arrhythmogenic right ventricular dysplasia arvd is an inherited heart disease arvd is caused by genetic defects of the parts of heart muscle also called myocardium or cardiac muscle known as desmosomes areas on the surface of heart muscle cells which link the cells together the desmosomes are composed of several proteins and many of those proteins can have harmful mutations the disease is a type of nonischemic cardiomyopathy that involves primarily the right ventricle it is characterized by hypokinetic areas involving the free wall of the right ventricle with fibrofatty replacement of the right ventricular myocardium with associated arrhythmias originating in the right ventricle arvd can be found in association with diffuse palmoplantar keratoderma and woolly hair in an autosomal recessive condition called naxos disease because this genetic abnormality can also affect the integrity of the superficial layers of the skin most exposed to pressure stress arvc d is an important cause of ventricular arrhythmias in children and young adults it is seen predominantly in males and 30 – 50 of cases have a familial distribution
the arrow information paradox information paradox for short and occasionally referred to as arrow s disclosure paradox named after kenneth arrow american economist and joint winner of the nobel memorial prize in economics with john hicks is a problem that companies face when managing intellectual property across their boundaries this happens when they seek external technologies for their business or external markets for their own technologies it has implications for the value of technology and innovations as well as their development by more than one firm and for the need for and limitations of patent protection arrow s information paradox theory was set out in a 1962 paper cornell law school professor oskar liivak has written in a paper for a conference at stanford university that arrow s paper has been one of the foundational theoretical pillars of the incentive based theory of patents as arrow ’ s work is thought to rule out a strictly market based solution a fundamental tenet of the paradox is that the customer i e the potential purchaser of the information describing a technology or other information having some value such as facts wants to know the technology and what it does in sufficient detail as to understand its capabilities or have information about the facts or products to decide whether or not to buy it once the customer has this detailed knowledge however the seller has in effect transferred the technology to the customer without any compensation this has been argued to show the need for patent protection if the buyer trusts the seller or is protected via contract then they only need to know the results that the technology will provide along with any caveats for its usage in a given context a problem is that sellers lie they may be mistaken one or both sides overlook side consequences for usage in a given context or some unknown unknown affects the actual outcome discussions of the value of patent rights have taken arrow s information paradox into account in their evaluations the theory has been the basis for many later economic studies these include theories that pre patent innovation can be carried out only by a single firm
arsenic poisoning is a medical condition caused by elevated levels of arsenic in the body the dominant basis of arsenic poisoning is from groundwater that naturally contains high concentrations of arsenic a 2007 study found that over 137 million people in more than 70 countries are probably affected by arsenic poisoning from drinking water
arsenic and many of its compounds are especially potent poisons arsenic disrupts atp production through several mechanisms at the level of the citric acid cycle arsenic inhibits pyruvate dehydrogenase and by competing with phosphate it uncouples oxidative phosphorylation thus inhibiting energy linked reduction of nad mitochondrial respiration and atp synthesis hydrogen peroxide production is also increased which might form reactive oxygen species and oxidative stress these metabolic interferences lead to death from multi system organ failure see arsenic poisoning probably from necrotic cell death not apoptosis a post mortem reveals brick red colored mucosa due to severe hemorrhage although arsenic causes toxicity it can also play a protective role
an arsenical keratosis is a growth of keratin on the skin caused by arsenic which occurs naturally in the earth s crust and is widely distributed in the environment arsenical compounds are used in industrial agricultural and medicinal substances arsenic is also found to be an environmental contaminant in drinking water well water and an occupational hazard for miners and glass workers arsenic may also causes other conditions including bowen s disease cardiovascular diseases developmental abnormalities neurologic and neurobehavioral disorders diabetes hearing loss hematologic disorders and various types of cancer arsenical keratoses may persist indefinitely and some may develop into invasive squamous cell carcinoma metastatic arsenic squamous cell carcinoma and arsenic induced malignancies in internal organs such as the bladder kidney skin liver and colon may result in death
arterial blood is the oxygenated blood in the circulatory system found in the lungs the left chambers of the heart and in the arteries it is bright red in color while venous blood is dark red in color but looks purple through the translucent skin it is the contralateral term to venous blood framed in the cardiac cycle often historically accredited to the wiggers diagram arterial blood has just passed through the lungs and is ready to boost oxygen to sustain the peripheral organs the essential difference between venous and arterial blood is the curve of the oxygen saturation of hemoglobin the difference in the oxygen content of the blood between the arterial blood and the venous blood is known as the arteriovenous oxygen difference
arterial embolism is a sudden interruption of blood flow to an organ or body part due to an embolus adhering to the wall of an artery blocking the flow of blood the major type of embolus being a blood clot thromboembolism sometimes pulmonary embolism is classified as arterial embolism as well in the sense that the clot follows the pulmonary artery carrying deoxygenated blood away from the heart however pulmonary embolism is generally classified as a form of venous embolism because the embolus forms in veins arterial embolism is the major cause of infarction which may also be caused by e g arterial compression rupture or pathological vasoconstriction
arterial tortuosity syndrome ats is a rare congenital connective tissue condition disorder characterized by elongation and generalized tortuosity of the major arteries including the aorta it is associated with hyperextensible skin and hypermobility of joints however symptoms vary depending on the patient because ats is so rare not much is known about the disease it exhibits autosomal recessive inheritance and the responsible gene is located at chromosome 20 q 13 it is associated with glut 10 also known as slc 2 a 10 and tgfbr 2
arteriolosclerosis is a form of cardiovascular disease affecting the small arteries and arterioles types include hyaline arteriolosclerosis and hyperplastic arteriolosclerosis both associated with vessel wall thickening and luminal narrowing that may cause downstream ischemic injury arteriolosclerosis is most often associated with hypertension and or diabetes mellitus the following terms are similar yet distinct in both spelling and meaning and can be easily confused arteriosclerosis arteriolosclerosis and atherosclerosis arteriosclerosis is a general term describing any hardening and loss of elasticity of medium or large arteries from the greek arteria meaning artery and sclerosis meaning hardening arteriolosclerosis is any hardening and loss of elasticity of arterioles small arteries atherosclerosis is a hardening of an artery specifically due to an atheromatous plaque the term atherogenic is used for substances or processes that cause atherosclerosis
arteriosclerosis is the thickening hardening and loss of elasticity of the walls of arteries this process gradually restricts the blood flow to one s organs and tissues and can lead to severe health risks brought on by atherosclerosis which is a specific form of arteriosclerosis caused by the buildup of fatty plaques cholesterol and some other substances in and on the artery walls
arteriosclerosis obliterans is an occlusive arterial disease most prominently affecting the abdominal aorta and the small and medium sized arteries of the lower extremities which may lead to absent dorsalis pedis posterior tibial and or popliteal artery pulses it is characterized by fibrosis of the tunica intima and calcification of the tunica media
an arteriovenous fistula is an abnormal connection or passageway between an artery and a vein it may be congenital surgically created for hemodialysis treatments or acquired due to pathologic process such as trauma or erosion of an arterial aneurysm
arteriovenous malformation avm is an abnormal connection between arteries and veins bypassing the capillary system this vascular anomaly is widely known because of its occurrence in the central nervous system but can appear in any location although many avms are asymptomatic they can cause intense pain or bleeding or lead to other serious medical problems avms are usually congenital and belong to the rasopathies the genetic transmission patterns of avm if any are unknown avm is not generally thought to be an inherited disorder unless in the context of a specific hereditary syndrome
the arteriovenous oxygen difference or a vo 2 diff is the difference in the oxygen content of the blood between the arterial blood and the venous blood it is an indication of how much oxygen is removed from the blood in capillaries as the blood circulates in the body the a vo 2 diff and cardiac output are the main factors that allow variation in the body s total oxygen consumption and are important in measuring vo 2 the a vo 2 diff is usually measured in millilitres of oxygen per 100 millilitres of blood ml 100 ml
arteritic anterior ischemic optic neuropathy aaion or arteritic aion is the cause of vision loss that occurs in temporal arteritis aka giant cell arteritis temporal arteritis is an inflammatory disease of medium sized blood vessels that happens especially with advancing age aaion occurs in about 15 20 percent of patients with temporal arteritis damage to the blood vessels supplying the optic nerves leads to insufficient blood supply ischemia to the nerve and subsequent optic nerve fiber death most cases of aaion result in nearly complete vision loss first to one eye if the temporal arteritis is left untreated the fellow eye will likely suffer vision loss as well within 1 – 2 weeks arteritic aion falls under the general category of anterior ischemic optic neuropathy which also includes non arteritic aion aion is considered an eye emergency immediate treatment is essential to rescue remaining vision an exhaustive review article published in march 2009 described the latest information on arteritic and non arteritic ischemic optic neuropathy both anterior a aion and na aion and posterior a pion na pion and surgical
arteritis is the inflammation of the walls of arteries usually as a result of infection or autoimmune response arteritis a complex disorder is still not entirely understood arteritis may be distinguished by its different types based on the organ systems affected by the disease a complication of arteritis is thrombosis which can be fatal arteritis and phlebitis are forms of vasculitis
arthralgia from greek arthro joint algos pain literally means joint pain it is a symptom of injury infection illnesses in particular arthritis or an allergic reaction to medication according to mesh the term arthralgia should only be used when the condition is non inflammatory and the term arthritis should be used when the condition is inflammatory
arthritis is a term often used to mean any disorder that affects joints symptoms generally include joint pain and stiffness other symptoms may include redness warmth swelling and decreased range of motion of the affected joints in some types other organs are also affected onset can be gradual or sudden there are over 100 types of arthritis the most common forms are osteoarthritis degenerative joint disease and rheumatoid arthritis osteoarthritis usually occurs with age and affects the fingers knees and hips rheumatoid arthritis is an autoimmune disorder that often affects the hands and feet other types include gout lupus fibromyalgia and septic arthritis they are all types of rheumatic disease treatment may include resting the joint and alternating between applying ice and heat weight loss and exercise may also be useful pain medications such as ibuprofen and acetaminophen paracetamol may be used in some a joint replacement may be useful osteoarthritis affects more than 3 8 of people while rheumatoid arthritis affects about 0 24 of people gout affects about 1 to 2 of the western population at some point in their lives in australia and the united states more than 20 of people have a type of arthritis overall the disease becomes more common with age arthritis is a common reason that people miss work and can result in a decreased quality of life the term is from greek arthro meaning joint and itis meaning inflammation
arthrofibrosis from greek arthro joint fibr fibrous and osis abnormality is a complication of injury or trauma where an excessive scar tissue response leads to painful restriction of joint motion with scar tissue forming within the joint and surrounding soft tissue spaces and persisting despite rehabilitation exercises and stretches scarring adhesions has been described in most major joints including knees shoulders hips ankles and wrists as well as spinal vertebrae
arthrogryposis multiplex congenita amc or simply arthrogryposis describes congenital joint contractures in two or more areas of the body it derives its name from greek literally meaning curving of joints arthron joint grȳpōsis late latin form of late greek grūpōsis hooking children born with one or more joint contractures have abnormal fibrosis of the muscle tissue causing muscle shortening and therefore are unable to perform passive extension and flexion in the affected joint or joints amc has been divided into three groups amyoplasia distal arthrogryposis and syndromic amyoplasia is characterized by severe joint contractures and muscle weakness distal arthrogryposis mainly involves the hands and feet types of arthrogryposis with a primary neurological or muscle disease belong to the syndromic group
arthrogryposis – renal dysfunction – cholestasis syndrome also known as arc syndrome is a cutaneous condition caused by a mutation in the vps 33 b gene most of the cases have been survived for infancy recently college of medical sciences in nepal reports a case of arc syndrome in a girl at the age of more than 18 years
an arthropathy is a disease of a joint
arthropod assault is a medical term describing a skin reaction to an insect bite characterized by inflammation and eosinophilic response
many species of arthropods insects arachnids and others regularly or occasionally bite or sting human beings insect saliva contains anticoagulants and enzymes that cause local irritation and allergic reactions insect venoms can be delivered by their stingers which often are modified ovipositors or by their mouthparts insect spider and scorpion venom can cause serious injury or death dipterans account for the majority of insect bites while hymenopterans account for the majority of stings among arachnids spider bites are the most common arthropods bite or sting humans for a number of reasons including feeding or defense arthropods are major vectors of human disease with the pathogens typically transmitted by bites
in immunology the arthus reaction ˌɑːrˈtuːs ˌɑːrˈtjuːs is a type of local type iii hypersensitivity reaction type iii hypersensitivity reactions are immune complex mediated and involve the deposition of antigen antibody complexes mainly in the vascular walls serosa pleura pericardium synovium and glomeruli this reaction is usually encountered in experimental settings following the injection of antigens
the field of articulatory phonetics is a subfield of phonetics in studying articulation phoneticians explain how humans produce speech sounds via the interaction of different physiological structures generally articulatory phonetics is concerned with the transformation of aerodynamic energy into acoustic energy aerodynamic energy refers to the airflow through the vocal tract its potential form is air pressure its kinetic form is the actual dynamic airflow acoustic energy is variation in the air pressure that can be represented as sound waves which are then perceived by the human auditory system as sound
artificial gravity is an acceleration resulting from the application of a force in the context of manned spaceflight artificial gravity may alleviate the adverse health effects of prolonged weightlessness astronauts routinely experience intermittent accelerations caused by the force of a rocket engine however the term artificial gravity usually refers to a sustained normal force provided by a rigid structure in uniform circular motion practical outer space applications of artificial gravity for humans have not yet been built and flown principally because of the large size of the spacecraft required to produce a useful centripetal acceleration comparable to little g
artificial intelligence and law ai and law is a subfield of artificial intelligence ai mainly concerned with applications of ai to legal informatics problems and original research on those problems it is also concerned to contribute in the other direction to export tools and techniques developed in the context of legal problems to ai in general for example theories of legal decision making especially models of argumentation have contributed to knowledge representation and reasoning models of social organization based on norms have contributed to multi agent systems reasoning with legal cases has contributed to case based reasoning and the need to store and retrieve large amounts of textual data has resulted in contributions to conceptual information retrieval and intelligent databases
an artificial neuron is a mathematical function conceived as a model of biological neurons artificial neurons are the constitutive units in an artificial neural network depending on the specific model used they may be called a semi linear unit nv neuron binary neuron linear threshold function or mcculloch – pitts mcp neuron the artificial neuron receives one or more inputs representing dendrites and sums them to produce an output representing a neuron s axon usually the sums of each node are weighted and the sum is passed through a non linear function known as an activation function or transfer function the transfer functions usually have a sigmoid shape but they may also take the form of other non linear functions piecewise linear functions or they are also often monotonically increasing continuous differentiable and bounded the thresholding function is inspired to build logic gates referred to as threshold logic with a renewed interest to build logic circuit resembling brain processing for example new devices such as memristors have been extensively used to develop such logic in the recent times the artificial neuron transfer function should not be confused with a linear system s transfer function
artistic freedom is the extent of freedom of an artist to produce art to his her own insight the extent can deviate to customs in a certain school of art directives of the assigner etc artistic freedom should not be confused to the freedom of art e g kunstfreiheit in germanic countries where it is a constitutional provision to prevent political censorship software patents are often seen as an example of one of these restrictions a related colloquial term is artistic license the distortion of fact alteration of the conventions of grammar or language or rewording of pre existing text made by an artist for artistic effect
arum type refers to the morphology of fungal hyphae living in or around plant root cells forms in arbuscular or tree like fashion branching off dichotomously at predetermined junctions this is a type of mycorrhizal infection whereby the fungus in question invaginates the cell membrane of a plant cell and branches in arbuscular manner arum type growth of hyphae is used in endomycorrhizal symbiosis with a plant often but not always accompanied by intercellular hyphal growth
asbestos related diseases are disorders of the lung and pleura caused by the inhalation of asbestos fibres asbestos related diseases include non malignant disorders such as asbestosis pulmonary fibrosis due to asbestos diffuse pleural thickening pleural plaques pleural effusion rounded atelectasis and malignancies such as lung cancer and malignant mesothelioma people who worked in jobs with high asbestos dust exposure are at the highest risk of developing asbestos related disease however exposure to asbestos may also occur in the worker ’ s home due to dust that has accumulated on the worker s clothing para occupational exposure asbestos related diseases can also occur as a result of non occupational environmental exposure asbestos was extensively used in many building materials therefore large quantities of asbestos still remain in buildings that were built prior to the restriction of asbestos use that applies in many countries the weathering and aging of such buildings may cause asbestos fragments to be released in the air and create a potential hazard anyone who disturbs the asbestos containing material during home maintenance and renovation can be affected although the exact risks are difficult to quantify
asbestosis is a chronic inflammatory and scarring disease affecting the tissue of the lungs people with the condition may experience severe shortness of breath and are at an increased risk for certain cancers including lung cancer and less commonly mesothelioma asbestosis specifically refers to fibrosis within the lung tissue from asbestos and not scarring around the outside of the lungs it is caused by the breathing in and retention of asbestos fibers it usually occurs after high intensity and or long term exposure to asbestos particularly in those individuals working on the production or end use of products containing asbestos and is therefore regarded as an occupational lung disease people with extensive occupational exposure to the mining manufacturing handling or removal of asbestos are at risk of developing asbestosis
ascariasis is a disease caused by the parasitic roundworm ascaris lumbricoides infections have no symptoms in more than 85 of cases especially if the number of worms is small symptoms increase with the number of worms present and may include shortness of breath and fever in the beginning of the disease these may be followed by symptoms of abdominal swelling abdominal pain and diarrhea children are most commonly affected and in this age group the infection may also cause poor weight gain malnutrition and learning problems infection occurs by eating food or drink contaminated with ascaris eggs from feces the eggs hatch in the intestines burrow through the gut wall and migrate to the lungs via the blood there they break into the alveoli and pass up the trachea where they are coughed up and swallowed the larvae then pass through the stomach for a second time into the intestine where they become adult worms ascariasis is classified as a neglected tropical disease as it is a type of soil transmitted helminthiasis these diseases are in turn part of a group of diseases called helminthiasis prevention is by improved sanitation which includes improving access to toilets and proper disposal of feces handwashing with soap appears protective in areas where more than 20 of the population is affected treating everyone at regular intervals is recommended reoccurring infections are common there is no vaccine treatments recommended by the world health organization are the medications albendazole mebendazole levamisole or pyrantel pamoate other effective agents include tribendimidine and nitazoxanide about 0 8 to 1 2 billion people globally have ascariasis with the most heavily affected populations being in sub saharan africa latin america and asia this makes ascariasis the most common form of soil transmitted helminthiasis as of 2010 it caused about 2 700 deaths a year down from 3 400 in 1990 another type of ascaris infects pigs
ascending cholangitis also known as acute cholangitis or simply cholangitis is an infection of the bile duct cholangitis usually caused by bacteria ascending from its junction with the duodenum first part of the small intestine it tends to occur if the bile duct is already partially obstructed by gallstones cholangitis can be life threatening and is regarded as a medical emergency characteristic symptoms include yellow discoloration of the skin or whites of the eyes fever abdominal pain and in severe cases low blood pressure and confusion initial treatment is with intravenous fluids and antibiotics but there is often an underlying problem such as gallstones or narrowing in the bile duct for which further tests and treatments may be necessary usually in the form of endoscopy to relieve obstruction of the bile duct the word is from greek chol bile ang vessel itis inflammation
ascher s syndrome or laffer ascher syndrome is a rare disorder first described in 1920 it is characterized by repeated episodes of lip and eyelid edema and occasionally euthyroid goiter the syndrome generally occurs within the first 20 years of life about 100 cases had been described by 1998
ascites is a gastroenterological term for an accumulation of fluid in the peritoneal cavity that exceeds 25 ml although most commonly due to cirrhosis severe liver disease or metastatic cancer its presence can be a sign of other significant medical problems such as budd – chiari syndrome diagnosis of the cause is usually with blood tests an ultrasound scan of the abdomen and direct removal of the fluid by needle or paracentesis which may also be therapeutic treatment may be with medication diuretics paracentesis or other treatments directed at the cause the term is from greek askítes meaning baglike
an example is along the calaveras fault in hollister california streets crossing the fault in hollister show significant offset and several houses sitting atop the fault are notably twisted yet habitable the city attracts geologists and geology students almost weekly there is also significant aseismic creep along the hayward fault in and north of hayward california but this is insufficient to prevent a substantial earthquake
aseptic meningitis or sterile meningitis is a condition in which the layers lining the brain the meninges become inflamed and a pyogenic bacterial source is not to blame meningitis is diagnosed on a history of characteristic symptoms and certain examination findings e g kernig s sign investigations should show an increase in the number of leukocytes present in the cerebrospinal fluid csf obtained via lumbar puncture normally being fewer than five visible leukocytes per microscopic high power field the term aseptic is frequently a misnomer implying a lack of infection on the contrary many cases of aseptic meningitis represent infection with viruses or mycobacteria that cannot be detected with routine methods while the advent of polymerase chain reaction has increased the ability of clinicians to detect viruses such as enterovirus cytomegalovirus and herpes virus in the csf many viruses can still escape detection additionally mycobacteria frequently require special stains and culture methods that make their detection difficult when csf findings are consistent with meningitis and microbiologic testing is unrevealing clinicians typically assign the diagnosis of aseptic meningitis — making it a relative diagnosis of exclusion aseptic meningitis can result from non infectious causes it is a relatively infrequent side effect of medications and can be an early finding in autoimmune disease there is no formal classification system it is usually by the causative organism if identified aseptic meningitis like non gonococcal urethritis non hodgkin lymphoma and atypical pneumonia merely states what a condition is not not what a condition is terms such as viral meningitis bacterial meningitis fungal meningitis neoplastic meningitis and drug induced aseptic meningitis can provide more information about the condition and without using one of these more specific terms it is difficult to describe treatment options or prognosis
asexuality is the lack of sexual attraction to anyone or low or absent interest in or desire for sexual activity it may be considered the lack of a sexual orientation or one of the variations thereof alongside heterosexuality homosexuality and bisexuality it may also be an umbrella term used to categorize a broader spectrum of various asexual sub identities a study in 2004 placed the prevalence of asexuality at 1 in the british population asexuality is distinct from abstention from sexual activity and from celibacy which are behavioral and generally motivated by factors such as an individual s personal or religious beliefs sexual orientation unlike sexual behavior is believed to be enduring some asexual people engage in sexual activity despite lacking sexual attraction or a desire for sex due to a variety of reasons such as a desire to pleasure themselves or romantic partners or a desire to have children acceptance of asexuality as a sexual orientation and field of scientific research is still relatively new as a growing body of research from both sociological and psychological perspectives has begun to develop while some researchers assert that asexuality is a sexual orientation other researchers disagree various asexual communities have started to form since the advent of the world wide web and social media the most prolific and well known of these communities is the asexual visibility and education network aven which was founded in 2001 by david jay
ash yellows candidatus phytoplasma fraxini is a disease in ash trees caused by phytoplasma a specialized group of bacteria which lack a cell wall and attack the phloem of trees this disease is relatively new so the disease cycle is mostly unknown although it is thought that insect vectors are used as the mode of transmission the disease is difficult to diagnose because some symptoms match those of stressed environmental conditions such as drought flooding or shallow soil when trees become infected they can survive for many years or immediately die depending on the environmental conditions and health of the tree the major symptom of this disease is witches broom which causes branches in tufts unfortunately there are not many strategies for controlling the disease besides avoiding areas where it is more prevalent
asherman syndrome as or fritsch syndrome is a condition characterized by adhesions and or fibrosis of the endometrium particularly but can also affect the myometrium it is often associated with dilation and curettage of the intrauterine cavity a number of other terms have been used to describe the condition and related conditions including intrauterine adhesions iua uterine cervical atresia traumatic uterine atrophy sclerotic endometrium endometrial sclerosis and intrauterine synechiae
ashi magari 足まがり leg turner is a ghostly phenomenon from the folklore of kagawa prefecture on shikoku japan it is a soft thing like a kitten or a wad of cotton which is felt wrapping itself around a person s leg at night impeding the ability to walk while it is not generally visible it is often believed to be the trick of a tanuki
ashman phenomenon also known as ashman beats describes a particular type of wide qrs complex often seen isolated that is typically seen in atrial fibrillation it is more often misinterpreted as a premature ventricular complex it is named for dr richard ashman of new orleans 1890 – 1969 after first being described by gouaux and ashman in 1947
ashta bhairava eight bhairavas are eight manifestations of the hindu god bhairava a ferocious aspect of the god shiva they guard and control the eight directions each bhairava has eight sub bhairavas under him all of the bhairavas are ruled and controlled by maha swarna kala bhairava who is considered the supreme ruler of time of the universe and the chief form of bhairava moola mantra tamil மூல மந்திரம் ஓம் ஸ்ரீம் க்லீம் ஸ்ரீம் சொர்ணப்ரதாயி நமஸ்ரீம் க்லீம் ஸ்ரீம்om sreem kleem sreemswaranaprathaayi namasreem kleem sreem ashta bhairava with their consort vahana mount direction he guards are given below also given the consecrated temples in tamil nadu india where people born on the listed nakshatras get his favours thosa nivarthi remedy for thosam and their lucky stones raasi stone
asian dust also yellow dust yellow sand yellow wind or china dust storms is a meteorological phenomenon which affects much of east asia year round but especially during the spring months the dust originates in the deserts of mongolia northern china and kazakhstan where high speed surface winds and intense dust storms kick up dense clouds of fine dry soil particles these clouds are then carried eastward by prevailing winds and pass over china north and south korea and japan as well as parts of the russian far east sometimes the airborne particulates are carried much further in significant concentrations which affect air quality as far east as the united states since the turn of the 21 st century it has become a serious problem due to the increase of industrial pollutants contained in the dust and intensified desertification in china causing longer and more frequent occurrences as well as in the last few decades when the aral sea of kazakhstan and uzbekistan started drying up due to the diversion of the amu river and syr river following a soviet agricultural program to irrigate central asian deserts mainly for cotton plantations
the askaryan effect is the phenomenon whereby a particle traveling faster than the phase velocity of light in a dense dielectric such as salt ice or the lunar regolith produces a shower of secondary charged particles which contain a charge anisotropy and thus emits a cone of coherent radiation in the radio or microwave part of the electromagnetic spectrum it is similar to the cherenkov effect it is named after gurgen askaryan a soviet armenian physicist who postulated it in 1962 the effect was first observed experimentally in 2000 38 years after its theoretical prediction so far the effect has been observed in silica sand rock salt ice and earth s atmosphere the effect is of primary interest in using bulk matter to detect ultra high energy neutrinos the antarctic impulse transient antenna anita experiment uses antennas attached to a balloon flying over antarctica to detect the askaryan radiation produced as cosmic neutrinos travel through the ice several experiments have also used the moon as a neutrino detector based on detection of the askaryan radiation
aspartylglucosaminuria agu is an inherited disease that is characterized by a decline in mental functioning accompanied by an increase in skin bone and joint issues the disease is caused by a defect in an enzyme known as aspartylglucosaminidase this enzyme plays a significant role in our bodies because it aids in breaking down certain sugars for example oligosaccharides that are attached to specific proteins for example glycoproteins aspartylglucosaminuria itself is characterized as a lysosomal disease because it does deal with inadequate activity in an enzyme s function aspartylglucosaminidase functions to break down glycoproteins these proteins are most abundant in the tissues of the body and in the surfaces of major organs such as the liver spleen thyroid and nerves when glycoproteins are not broken down aspartylglucosaminidase backs up in the lysosomes along with other substances this backup causes progressive damage to the tissues and organs
aspen trunk rot is a fungal disease that causes stem decay heart rot of living aspen trees the pathogen that causes this disease is the fungus phellinus tremulae most of the symptoms of this disease are internal with the only external signs of a diseased aspen being fruiting bodies called conks a single conk found on an aspen can indicate advanced decay of up 82 of the tree volume internal decayed wood of freshly cut aspens is spongy yellow white colored surrounded by black zones of discoloration and contains a distinct wintergreen smell the fungus is spread via airborne spores released from the fruiting body which can infect through dead branches branch stubs or wounds in the tree although no direct management control is known harvesting aspen stands that have been damaged or harvesting stands before decay becomes advanced minimizes tree loss aspen wood is white malleable but strong and heat tolerant and therefore has many commercial uses including matches packing paper lumber plywood pulp and animal beds aspen trees diseased with aspen trunk rot decrease the economic value of the lumber
asperger syndrome as also known as asperger s is a developmental disorder characterized by significant difficulties in social interaction and nonverbal communication along with restricted and repetitive patterns of behavior and interests as a milder autism spectrum disorder asd it differs from other asds by relatively normal language and intelligence although not required for diagnosis physical clumsiness and unusual use of language are common symptoms usually begin before two years old and typically last for a person s entire life the exact cause of asperger s is unknown while it is likely partly inherited the underlying genetics have not been determined conclusively environmental factors are also believed to play a role brain imaging has not identified a common underlying problem the diagnosis of asperger s was removed in the 2013 fifth edition of the diagnostic and statistical manual of mental disorders dsm 5 and people with these symptoms are now included within the autism spectrum disorder along with autism and pervasive developmental disorder not otherwise specified it remains within the tenth edition of the international classification of diseases icd 10 as of 2015 there is no single treatment and the effectiveness of particular interventions is supported by only limited data treatment is aimed at improving poor communication skills obsessive or repetitive routines and physical clumsiness interventions may include social skills training cognitive behavioral therapy physical therapy speech therapy parent training and medications for associated problems such as mood or anxiety most children improve as they grow up but social and communication difficulties usually persist some researchers and people on the autism spectrum have advocated a shift in attitudes toward the view that autism spectrum disorder is a difference rather than a disease that must be treated or cured in 2013 asperger s was estimated to affect 31 million people globally the syndrome is named after the austrian pediatrician hans asperger who in 1944 described children in his practice who lacked nonverbal communication had limited understanding of others feelings and were physically clumsy the modern conception of asperger syndrome came into existence in 1981 and went through a period of popularization it became a standardized diagnosis in the early 1990 s many questions and controversies remain about aspects of the disorder there is doubt about whether it is distinct from high functioning autism hfa partly because of this the percentage of people affected is not firmly established
an aspergilloma also known as a mycetoma or fungus ball is a clump of mold which exists in a body cavity such as a paranasal sinus or an organ such as the lung by definition it is caused by fungi of the genus aspergillus
aspergillosis is the name given to a wide variety of diseases caused by infection by fungi of the genus aspergillus the majority of cases occur in people with underlying illnesses such as tuberculosis or chronic obstructive pulmonary disease copd but with otherwise healthy immune systems most commonly aspergillosis occurs in the form of chronic pulmonary aspergillosis cpa aspergilloma or allergic bronchopulmonary aspergillosis abpa some forms are intertwined for example abpa and simple aspergilloma can progress to cpa other non invasive manifestations include fungal sinusitis both allergic in nature and with established fungal balls otomycosis ear infection keratitis eye infection and onychomycosis nail infection in most instances these are less severe and curable with effective antifungal treatment people with deficient immune systems — such as patients undergoing hematopoietic stem cell transplantation chemotherapy for leukaemia or aids — are at risk of more disseminated disease acute invasive aspergillosis occurs when the immune system fails to prevent aspergillus spores from entering the bloodstream via the lungs without the body mounting an effective immune response fungal cells are free to disseminate throughout the body and can infect major organs such as the heart and kidneys the most frequently identified pathogen is aspergillus fumigatus — a ubiquitous organism that is capable of living under extensive environmental stress it is estimated that most humans inhale thousands of aspergillus spores daily but they do not affect most people ’ s health due to effective immune responses taken together the major chronic invasive and allergic forms of aspergillosis account for around 600 000 deaths annually worldwide
aspermia is the complete lack of semen with ejaculation not to be confused with azoospermia the lack of sperm cells in the semen it is associated with infertility one of the causes of aspermia is retrograde ejaculation which can be brought on by excessive drug use or as a result of prostate surgery it can also be caused by alpha blockers such as tamsulosin and silodosin another cause of aspermia is ejaculatory duct obstruction which may result in a complete lack of or a very low concentration semen oligospermia in which the semen contains only the secretion of accessory prostate glands downstream to the orifice of the ejaculatory ducts aspermia can be caused by androgen deficiency this can be the result of absence of puberty in which the prostate gland and seminal vesicles which are the main sources of semen remain small due to lack of androgen exposure and do not produce seminal fluid or of treatment for prostate cancer such as maximal androgen blockade
asphyxia or asphyxiation is a condition of severely deficient supply of oxygen to the body that arises from abnormal breathing an example of asphyxia is choking asphyxia causes generalized hypoxia which affects primarily the tissues and organs there are many circumstances that can induce asphyxia all of which are characterized by an inability of an individual to acquire sufficient oxygen through breathing for an extended period of time asphyxia can cause coma or death in 2013 about 1 6 million cases of unintentional suffocation occurred the word asphyxia is from ancient greek α without and σφύξις sphyxis squeeze throb of heart
asphyxiating thoracic dysplasia or jeune syndrome is a ciliopathy it is also known as jeune syndrome it was described in 1955 types include jeune syndrome is a rare genetic disorder that affects the way a child ’ s cartilage and bones develop it begins before the child is born jeune syndrome affects the child s rib cage pelvis arms and legs usually problems with the rib cage cause the most serious health problems for children with jeune syndrome their rib cages thorax are smaller and narrower than usual this can keep the child s lungs from developing fully or expanding when the child inhales the child may breathe rapidly and shallowly they may have trouble breathing when they have an upper or lower respiratory infection like pneumonia breathing trouble can range from mild to severe in some children it is not noticeable aside from fast breathing in most children breathing problems are serious about 60 to 70 of children with this condition die from respiratory failure as babies or young children children with jeune syndrome who survive often develop problems with their kidneys another serious feature of jeune syndrome over time they may experience renal failure as a result few children with jeune syndrome live into their teen years children with jeune syndrome have a form of dwarfism they are short in stature and their arms and legs are shorter than most people ’ s another name for jeune syndrome is asphyxiating thoracic dystrophy this diagnosis is grouped with other chest problems called thoracic insufficiency syndrome tis
aspiration pneumonia is bronchopneumonia that develops due to the entrance of foreign materials into the bronchial tree usually oral or gastric contents including food saliva or nasal secretions depending on the acidity of the aspirate a chemical pneumonitis can develop and bacterial pathogens particularly anaerobic bacteria may add to the inflammation
aspirin induced asthma is also termed samter s triad samter s syndrome aspirin exacerbated respiratory disease aerd and recently by an appointed task force of the european academy of allergy and clinical immunology world allergy organization eaaci wao non steroidal anti inflammatory drugs exacerbated respiratory disease n erd the syndrome which eaaci who classifies as one of 5 types of non steroidal anti inflammatory drug hypersensitivity or nsaid hypersensitivity reactions is a medical condition initially defined as consisting of three key features viz asthma respiratory symptoms exacerbated by aspirin and nasal ethmoidal polyposis however the syndrome s symptoms are exacerbated by a large variety of other nsaid besides aspirin the symptoms of respiratory reactions in this syndrome are hypersensitivity reactions to nsaids rather than the typically described true allergic reactions that trigger other common allergen induced asthma rhinitis or hives the nsaid induced reactions do not appear to involve the common mediators of true allergic reactions immunoglobulin e or t cells rather aerd is a type of nsaid induced hypersensitivity syndrome
aspirin poisoning or salicylism is acute or chronic poisoning with aspirin or other salicylates a single overdose may cause acute poisoning continuous usage of an elevated dosage over long periods of time may cause chronic poisoning acute overdose has a mortality rate of 2 chronic overdose is more commonly lethal with a mortality rate as high as 25 chronic overdose may be especially severe in children no antidotes currently exist for aspirin poisoning signs and symptoms may range from mild nausea and vomiting abdominal pain lethargy tinnitus and dizziness to severe such as seizure or cerebral edema depending on the dose consumed toxicity is managed with a number of potential treatments including activated charcoal intravenous dextrose and normal saline sodium bicarbonate and dialysis
asplenia refers to the absence of normal spleen function and is associated with some serious infection risks hyposplenism is used to describe reduced hypo splenic functioning but not as severely affected as with asplenism
asplenia with cardiovascular anomalies also known as ivemark syndrome and right atrial isomerism is an example of a heterotaxy syndrome these uncommon congenital disorders are characterized by defects in the heart spleen and paired organs such as the lungs and kidneys another name is asplenia cardiovascular defect heterotaxy right atrial isomerism is named for its discoverer swedish pathologist biörn ivemark
asset poverty is an economic and social condition that is more persistent and prevalent than income poverty it can be defined as a household ’ s inability to access wealth resources that are sufficient to provide for basic needs for a period of three months basic needs refer to the minimum standards for consumption and acceptable needs wealth resources consist of home ownership other real estate second home rented properties etc net value of farm and business assets stocks checking and savings accounts and other savings money in savings bonds life insurance policy cash values etc wealth is measured in three forms net worth net worth minus home equity and liquid assets net worth consists of all the aspects mentioned above net worth minus home equity is the same except it does not include home ownership in asset calculations liquid assets are resources that are readily available such as cash checking and savings accounts stocks and other sources of savings there are two types of assets tangible and intangible tangible assets most closely resemble liquid assets in that they include stocks bonds property natural resources and hard assets not in the form of real estate intangible assets are simply the access to credit social capital cultural capital political capital and human capital there are trends in the development of asset poverty over time and several factors that cause certain groups to fall into asset poverty more easily than others changes in these factors and structures have occurred over the years but asset poverty is continually higher than other forms of poverty such as income poverty the reason for this difference is that asset poverty accounts for a household ’ s total wealth and not just the current income level it provides a more accurate description of a household ’ s true financial state wealth leads to increased economic security and assets create a form of security during hardship one can use assets to pay for further education better housing or to maintain a certain standard of living after retirement households lacking sufficient assets are forced to live from paycheck to paycheck and face economic hardship when changes in income occur those who lack adequate assets are unable to seek a better lifestyle and improve their quality of life because they lack the financial resources to do so by any measure poverty in the united states is increasing in 2010 the country saw the poverty rate for individuals rise to 15 1 percent the highest level in nearly two decades more than 46 million people now live below the federal poverty line of 22 350 for a family of four however the official poverty rate released annually by the census bureau highlights just one aspect of household finances namely the percentage of people with insufficient income to cover their day to day expenses it does not count the number of families who have insufficient resources – money in the bank or assets such as a home or a car – to meet emergencies or longer term needs when these longer term needs are factored in substantially more people in the united states today are facing a future of limited hope for long term financial security according to the cfed 2013 assets opportunity scorecard 44 percent of households – nearly half of americans – are living in liquid asset poverty these families do not have the savings or other assets to cover basic expenses equivalent to what could be purchased with a poverty level income for three months if a layoff or other emergency leads to loss of income the term asset poverty is also used in a low income poor countries context where the poverty line may be taken at the international standard of 1 25 per day or sometimes 2 per day poor rural families in particular do not receive say 1 each day but rather this is a daily average or corresponds to a yearly average of 365 the asset poor might by chance have income above the poverty line for a time like a month but their level of assets predict they will be poor in an average month
asset price inflation is an economic phenomenon denoting a rise in price of assets as opposed to ordinary goods and services typical assets are financial instruments such as bonds shares and their derivatives as well as real estate and other capital goods although the values of such assets are often casually said to inflate this should not be confused with inflation as a defined term a more accurate description for an increase in the value of a capital asset is appreciation
the assignment problem is one of the fundamental combinatorial optimization problems in the branch of optimization or operations research in mathematics it consists of finding a maximum weight matching or minimum weight perfect matching in a weighted bipartite graph in its most general form the problem is as follows the problem instance has a number of agents and a number of tasks any agent can be assigned to perform any task incurring some cost that may vary depending on the agent task assignment it is required to perform all tasks by assigning exactly one agent to each task and exactly one task to each agent in such a way that the total cost of the assignment is minimized if the numbers of agents and tasks are equal and the total cost of the assignment for all tasks is equal to the sum of the costs for each agent or the sum of the costs for each task which is the same thing in this case then the problem is called the linear assignment problem commonly when speaking of the assignment problem without any additional qualification then the linear assignment problem is meant
assortative mating is a mating pattern and a form of sexual selection in which individuals with similar phenotypes mate with one another more frequently than would be expected under a random mating pattern examples of similar phenotypes include but are not limited to body size skin coloration pigmentation and age assortative mating also referred to as positive assortative mating or homogamy may increase genetic relatedness within the family assortative mating can be contrasted with disassortative mating also known as negative assortative mating or heterogamy in which individuals with dissimilar genotypes and or phenotypes mate with one another more frequently than would be expected under random mating disassortative mating reduces the genetic similarities within the family positive assortative mating occurs more frequently than negative assortative mating in both cases due to the nonrandom mating pattern there is a deviation from the hardy – weinberg principle which states that genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences
astasia abasia refers to the inability to either stand or walk in a normal manner astasia refers to the inability to stand upright unassisted abasia refers to lack of motor coordination in walking the term abasia literally means that the base of gait the lateral distance between the two feet is inconstant or unmeasurable when seen in conversion disorder the gait is bizarre and is not suggestive of a specific organic lesion often the patient sways wildly and nearly falls recovering at the last moment an acquired total inability to stand and walk can be seen in true neurological diseases including stroke parkinson s disease damage to the cerebellum guillain – barré syndrome normal pressure hydrocephalus and many others in normal pressure hydrocephalus for example when the condition remains untreated the patient s gait becomes shortened with frequent shuffling and falls eventually standing sitting and even rolling over in bed become impossible this advanced state is referred to as hydrocephalic astasia abasia
aster yellows is a chronic systemic plant disease caused by a bacterium like organism called a phytoplasma the aster yellows phytoplasma ayp affects 300 species in 38 families of broad leaf herbaceous plants primarily in the aster family as well as important cereal crops such as wheat and barley symptoms are variable and can include phyllody virescence chlorosis stunting and sterility of flowers the aster leafhopper vector macrosteles quadrilineatus moves the aster yellows phytoplasma from plant to plant its economic burden is primarily felt in the carrot daucus carota ssp sativus crop industry as well as the nursery industry no cure is known for plants infected with aster yellows infected plants should be removed immediately to limit the continued spread of the phytoplasma to other susceptible plants however in agricultural settings such as carrot fields some application of chemical insecticides has proven to minimize the rate of infection by killing the vector
astereognosis or tactile agnosia if only one hand is affected is the inability to identify an object by active touch of the hands without other sensory input such as visual or sensory information an individual with astereognosis is unable to identify objects by handling them despite intact elementary tactile proprioceptive and thermal sensation with the absence of vision i e eyes closed an individual with astereognosis is unable to identify what is placed in their hand based on cues such as texture size spatial properties and temperature as opposed to agnosia when the object is observed visually one should be able to successfully identify the object individuals with tactile agnosia may be able to identify the name purpose or origin of an object with their left hand but not their right or vice versa or both hands astereognosis refers specifically to those who lack tactile recognition in both hands in the affected hand s they may be able to identify basic shapes such as pyramids and spheres with abnormally high difficulty but still not tactilely recognize common objects by easily recognizable and unique features such as a fork by its prongs though the individual may report feeling a long metal rod with multiple pointy rods stemming off in uniform direction these symptoms suggest that a very specific part of the brain is responsible for making the connections between tactile stimuli and functions relationships of that stimuli which along with the relatively low impact this disorder has on a person s quality of life helps explain the rarity of reports and research of individuals with tactile agnosia astereognosis is associated with lesions of the parietal lobe or dorsal column or parieto temporo occipital lobe posterior association areas of either the right or left hemisphere of the cerebral cortex despite cross talk between the dorsal and ventral cortices fmri results suggest that those with ventral cortex damage are less sensitive to object 3 d structure than those with dorsal cortex damage unlike the ventral cortex the dorsal cortex can compute object representations thus those with object recognition impairments are more likely to have acquired damage to the dorsal cortex those suffering from alzheimer ’ s disease show a reduction in stereognosis the ability to perceive and recognize the form of an object in the absence of visual and auditory information this supports the notion that astereognosis appears to be an associative disorder in which the connections between tactile information and memory is disturbed while astereogonsis is characterized by the lack of tactile recognition in both hands it seems to be closely related to tactile agnosia impairment connected to one hand tactile agnosia observations are rare and case specific josef gerstmann recounts his experience with patient jh a 34 year old infantryman who suffered a lesion to the posterior parietal lobe due to a gunshot following the injury jh was unable to recognize or identify everyday objects by their meaning origin purpose and use with his left hand using tactile sensation alone his motility performance elementary sensitivity and speech were intact and he lacked abnormalities in brain nerves the majority of all objects jh touched with his left hand went unrecognized but very simple objects i e globes pyramids cube etc were regularly recognized based on form alone for more complex objects his behavior and recognition varied daily based on his tactile resources that changed over time and depended on his fatigue that is jh ’ s ability to recognize depended on his concentration and ability to recognize simple forms and single qualities like size shape etc with further interrogation and greater effort he was able to correctly identify more specific features of an object ie softness rounded or cornered broad or narrow and could even draw a copy of it but he was often left unable to identify the object by name use or origin this behavioral deficit occurred even if jh had handled the object in his fully intact right hand
in astronomy an asterism is any pattern of stars recognized in the earth s night sky it may be part of an official constellation or it may be composed of stars from more than one constellation asterisms are composed of stars which although visible in the same general area of the sky as viewed from earth are located at very different distances from earth at great distances from each other many asterisms are simple shapes composed of a few bright stars making them easy to identify and particularly useful to people who are familiarizing themselves with the night sky in colloquial usage constellation is a synonym of asterism but in astronomy a constellation is an officially recognized area of the sky surrounding certain asterisms for example the asterism known as the big dipper comprises the seven brightest stars in the international astronomical union iau constellation ursa major asterism is the more general term referring to any identified pattern of stars
asterixis also called the flapping tremor or liver flap is a tremor of the hand when the wrist is extended sometimes said to resemble a bird flapping its wings this motor disorder is characterized by an inability to actively maintain a position which is demonstrated by jerking movements of the outstretched hands when bent upward at the wrist the tremor is caused by abnormal function of the diencephalic motor centers in the brain which regulate the muscles involved in maintaining position asterixis is associated with various encephalopathies due especially to faulty metabolism the term derives from the greek a not and stērixis fixed position asterixis is the inability to maintain posture due to a metabolic encephalopathy this can be elicited on physical exam by having the patient extend their arms and bend their hands back with a metabolic encephalopathy the patient is unable to hold their hands back resulting in a “ flapping ” motion consistent with asterixis it can be seen in any metabolic encephalopathy e g chronic renal failure severe congestive heart failure acute respiratory failure and commonly in decompensated liver failure
an asteroid body is a microscopic finding seen within the giant cells of granulomas in diseases such as sarcoidosis and foreign body giant cell reactions there is controversy about what they are composed of traditionally they were thought to be cytoskeletal elements and to consist primarily of vimentin however more recent research suggested that that was incorrect and that they may be composed of lipids arranged into bilayer membranes they were also once thought to be related to centrioles an organelle involved in cell division in eukaryotes
asteroid hyalosis is a degenerative condition of the eye involving small white opacities in the vitreous humor it is known to occur in humans dogs cats and chinchillas clinically these opacities are quite refractile giving the appearance of stars or asteroids shining in the night sky — except that ocular asteroids are often quite mobile ocular asteroids must be distinguished from the more common typical vitreous floaters which are usually fibrillar or cellular condensates the cause of asteroid hyalosis is unknown but it has been associated with diabetes mellitus hypertension hypercholesterolemia and in certain animals tumors of the ciliary body in dogs asteroid hyalosis is considered to be an age related change the asteroid bodies are made up of hydroxylapatite which in turn consists of calcium and phosphates or phospholipids while asteroid hyalosis does not usually severely affect vision the floating opacities can be quite annoying and may interfere significantly with visualization and testing of the retina while treatment of asteroid hyalosis is usually unnecessary vitrectomy may occasionally be indicated for both diagnostic and therapeutic purposes
in medicine asthenization is a condition experienced by astronauts following long term space flight in which following return to earth the astronaut experiences symptoms such as fatigue irritability lack of appetite and sleep disorders the condition s name derives from asthenia which is a medical term denoting a feeling of weakness without actual loss of strength it is suspected to be a psychosomatic effect of the result of overachieving astronauts no longer having a goal after becoming astronauts or potentially a neurological effect of microgravity buzz aldrin the second man to walk on the moon was afflicted with this condition after returning from the moon
asthenozoospermia or asthenospermia is the medical term for reduced sperm motility complete asthenozoospermia that is 100 immotile spermatozoa in the ejaculate is reported at a frequency of 1 of 5000 men causes of complete asthenozoospermia include metabolic deficiencies ultrastructural abnormalities of the sperm flagellum see primary ciliary dyskinesia and necrozoospermia it decreases the sperm quality and is therefore one of the major causes of infertility or reduced fertility in men a method to increase the chance of pregnancy is icsi the percentage of viable spermatozoa in complete asthenozoospermia varies between 0 and 100
asthma is a common long term inflammatory disease of the airways of the lungs it is characterized by variable and recurring symptoms reversible airflow obstruction and bronchospasm symptoms include episodes of wheezing coughing chest tightness and shortness of breath these episodes may occur a few times a day or a few times per week depending on the person they may become worse at night or with exercise asthma is thought to be caused by a combination of genetic and environmental factors environmental factors include exposure to air pollution and allergens other potential triggers include medications such as aspirin and beta blockers diagnosis is usually based on the pattern of symptoms response to therapy over time and spirometry asthma is classified according to the frequency of symptoms forced expiratory volume in one second fev 1 and peak expiratory flow rate it may also be classified as atopic or non atopic where atopy refers to a predisposition toward developing a type 1 hypersensitivity reaction there is no cure for asthma symptoms can be prevented by avoiding triggers such as allergens and irritants and by the use of inhaled corticosteroids long acting beta agonists laba or antileukotriene agents may be used in addition to inhaled corticosteroids if asthma symptoms remain uncontrolled treatment of rapidly worsening symptoms is usually with an inhaled short acting beta 2 agonist such as salbutamol and corticosteroids taken by mouth in very severe cases intravenous corticosteroids magnesium sulfate and hospitalization may be required in 2013 242 million people globally had asthma up from 183 million in 1990 it caused about 489 000 deaths in 2013 most of which occurred in the developing world it often begins in childhood the rates of asthma have increased significantly since the 1960 s asthma was recognized as early as ancient egypt the word asthma is from the greek ἅσθμα ásthma which means panting
astigmatism is a type of refractive error in which the eye does not focus light evenly on the retina this results in distorted or blurred vision at all distances other symptoms can include eyestrain headaches and trouble driving at night if it occurs early in life it can result in amblyopia the cause of astigmatism is unclear it is believed to be partly related to genetic factors the underlying mechanism involves an irregular curvature of the cornea or abnormalities in the lens of the eye diagnosis is by an eye exam three options exist for the treatment glasses contact lenses and surgery glasses are the simplest contact lenses can provide a wider field of vision refractive surgery permanently changes the shape of the eye in europe and asia astigmatism affects between 30 and 60 of adults people of all ages can be affected astigmatism was first reported by thomas young in the early 1800 s
astroblastoma is a rare glial tumor derived from the astroblast a type of cell that closely resembles spongioblastoma and astrocytes astroblastoma cells are most likely found in the supratentorial region of the brain that houses the cerebrum an area responsible for all voluntary movements in the body it also occurs significantly in the frontal lobe parietal lobe and temporal lobe areas where movement language creation memory perception and environmental surroundings are expressed these tumors can be present in major brain areas not associated with the main cerebral hemispheres including the cerebellum optic nerve cauda equina hypothalamus and brain stem the most defining physical symptom of astroblastoma regardless of location is elevated intracranial pressure occurring when cerebrospinal fluid in the subarachnoid space exhibits heavy pressure and decreased blood flow resulting in throbbing headache or nausea for the patient despite widespread localization in the brain astroblastoma is rarely reported in oncological studies accounting for only 0 45 – 2 8 of all brain gliomas since its discovery in 1926 without a doubt astroblastoma remains one of the most challenging and problematic tumors to diagnose and treat among all nervous system cancers
astrocytomas are a type of cancer of the brain they originate in a particular kind of glial cells star shaped brain cells in the cerebrum called astrocytes this type of tumor does not usually spread outside the brain and spinal cord and it does not usually affect other organs astrocytomas are the most common glioma and can occur in most parts of the brain and occasionally in the spinal cord within the astrocytomas there are two broad classes recognized in literature those with narrow zones of infiltration mostly noninvasive tumors e g pilocytic astrocytoma subependymal giant cell astrocytoma pleomorphic xanthoastrocytoma that often are clearly outlined on diagnostic images diffuse zones of infiltration e g high grade astrocytoma anaplastic astrocytoma glioblastoma that share various features including the ability to arise at any location in the cns central nervous system but with a preference for the cerebral hemispheres they occur usually in adults and an intrinsic tendency to progress to more advanced grades people can develop astrocytomas at any age the low grade type is more often found in children or young adults while the high grade type are more prevalent in adults astrocytomas in the base of the brain are more common in young people and account for roughly 75 of neuroepithelial tumors
astrogliosis also known as astrocytosis or referred to as reactive astrocytosis is an abnormal increase in the number of astrocytes due to the destruction of nearby neurons from cns trauma infection ischemia stroke autoimmune responses and neurodegenerative disease in healthy neural tissue astrocytes play critical roles in energy provision regulation of blood flow homeostasis of extracellular fluid homeostasis of ions and transmitters regulation of synapse function and synaptic remodeling astrogliosis changes the molecular expression and morphology of astrocytes causing scar formation and in severe cases inhibition of axon regeneration
an astrophysical jet hereafter jet is a phenomenon often seen in astronomy where streams of matter are emitted along the axis of rotation of a compact object while it is still the subject of ongoing research to understand how jets are formed and powered the two most often proposed origins are dynamic interactions within the accretion disk or a process associated with the compact central object such as a black hole or neutron star when matter is emitted at speeds approaching the speed of light these jets are called relativistic jets because the effects of special relativity become important the largest jets are those from black holes in active galaxies such as quasars and radio galaxies other systems which often contain jets include cataclysmic variable stars x ray binaries and t tauri stars herbig – haro objects are caused by the interaction of jets with the interstellar medium bipolar outflows or jets may also be associated with protostars young forming stars or with evolved post agb stars often in the form of bipolar nebulae many stellar objects with accretion disks have jets although those from super massive black holes are generally the fastest and most active while it is not known exactly how accretion disks would accelerate jets or produce positron electron plasma they are generally thought to generate tangled magnetic fields that cause the jets to accelerate and collimate the hydrodynamics of a de laval nozzle may also give a hint to the mechanisms involved
the asymmetric keck allylation is a chemical reaction that involves the addition of allyl group to an aldehyde
asymmetric addition of alkenylmetals to aldehydes is a chemical reaction in enantioselective synthesis that reacts an alkenylmetal with an aldehyde to give an allyl alcohol figure asymmetric addition of alkenylmetals to aldehydes the stereoselectivity in the reaction is typically controlled by the asymmetric ligands used providing a strategy to introduce controlled asymmetry into the molecule controlled molecular asymmetry or enantioselectivity is crucial for controlling the bioactivity of the synthesized molecules and demanded by drug authorities in drug synthesis in this case the ligands chelate to the transition metal to create a chiral environment which enables the selective formation of a particular enantiomer various transition metals such as zinc nickel chromium and rhodium have been used in this reaction asymmetric addition of alkenylmetals to aldehydes has been widely used in total synthesis of natural product for example the key cyclization step in the total synthesis of r muscone was an intramolecular asymmetric addition of a vinylzinc derivative to an aldehyde using a chiral amino isoborneol ligand figure a asymmetric addition of alkenylzinc to aldehyde in the total synthesis of muscone the reaction used a terminal alkyne a as the substrate which generated alkenylborate reagent b through monohydroboration reaction after transmetalation with diethylzinc the generated alkenylzinc reagent c further reacted with the aldehyde d through exclusive addition to the π face under the control of 3 exo dimethylamino isoborneol daib as a ligand figure b detailed steps for the reaction
asymmetric addition of alkynylzinc compounds to aldehydes is an enantioselective chemical reaction where alkynylzinc reagents react with aldehydes to generate propargyl alcohols propargyl alcohols are versatile precursors to various complex molecules making the asymmetric addition of alkynylzinc compounds to aldehydes a particularly useful method for the synthesis of natural products and pharmaceutical drugs for example carreira and co workers have used this asymmetric reaction for the synthesis of natural product leucascandrolide a one of the first powerfully bioactive metabolites isolated from a calcareous sponge various chiral ligands have been developed for the asymmetric addition of alkynylzinc compounds to aldehydes because of the acidity of the terminal alkynyl proton the alkynylzinc compounds can be generated in situ from reaction of terminal alkynes with alkylzincs or zn otf 2 the first example of catalytic asymmetric addition of alkynylzinc compounds to aldehydes was reported by kenso soai and co workers in 1990 in their experiments chiral amino alcohols and amines a to c in figure examples of ligands used in asymmetric addition of alkynylzinc compounds to aldehydes were used as ligands and the alkynylzinc reagent was prepared from reaction of alkyne with diethylzinc although the yields were high but the highest enantiomeric excess achieved was only 34 with 5 mol ligand loading erick carreira and co workers reported high enantiomeric excess using a chiral amino alcohol n methylephedrine d stoichiometric amount of d was used in their reactions and up to 99 of enantiomeric excess was achieved at room temperature for a broad range of aldehydes in carreira ’ s experiments the alkynylzinc reagent was generated from the reaction of alkyne with zn otf 2 in the presence of an amine base
asymmetric crying facies acf also called cayler cardiofacial syndrome partial unilateral facial paresis and hypoplasia of depressor angula oris muscle is a minor congenital anomaly caused by agenesis or hypoplasia of the depressor anguli oris muscle one of the muscles that control the movements of the lower lip this unilateral facial weakness is first noticed when the infant cries or smiles affecting only one corner of the mouth and occurs on the left side in nearly 80 of cases it is associated with other birth defects in more than 50 of cases when the hypoplasia of the depressor anguli oris muscle is associated with congenital cardiac defects the term cayler cardiofacial syndrome is used cayler syndrome is part of 22 q 11 2 deletion syndrome it was characterized by cayler in 1969
asymmetric hydrogenation is a chemical reaction that adds two atoms of hydrogen preferentially to one of two faces of an unsaturated substrate molecule such as an alkene or ketone the selectivity derives from the manner that the substrate binds to the chiral catalysts in jargon this binding transmits spatial information what chemists refer to as chirality from the catalyst to the target favoring the product as a single enantiomer this enzyme like selectivity is particularly applied to bioactive products such as pharmaceutical agents and agrochemicals a generic asymmetric hydrogenation of n acetyl dehydroaminoacids
asymmetric periflexural exanthem of childhood apec also known as unilateral laterothoracic exanthem is a rare self limited and spontaneously resolving skin rash of the exanthem type with unknown etiology that occurs in children it occurs primarily in the late winter and early spring most common in europe and affecting girls more often than boys it is probably viral but no virus has yet been associated with the condition
asymmetry is the absence of or a violation of symmetry the property of an object being invariant to a transformation such as reflection symmetry is an important property of both physical and abstract systems and it may be displayed in precise terms or in more aesthetic terms the absence of violation of symmetry that are either expected or desired can have important consequences for a system
asymptomatic inflammatory prostatitis is a painless inflammation of the prostate gland where there is no evidence of infection it should be distinguished from the other categories of prostatitis characterised by either pelvic pain or evidence of infection such as chronic bacterial prostatitis acute bacterial prostatitis and chronic pelvic pain syndrome cpps it is a common finding in men with benign prostatic hyperplasia
in mathematics an asymptotic formula for a quantity function or expression depending on natural numbers or on a variable taking real numbers as values is a function of natural numbers or of a real variable whose values are nearly equal to the values of the former when both are evaluated for the same large values of the variable an asymptotic formula for a quantity is a function which is asymptotically equivalent to the former more generally an asymptotic formula is a statement of equality between two functions which is not a true equality but which means the ratio of the two functions approaches 1 as the variable approaches some value usually infinity
asystole also known as flatline is a state of no electrical activity from the heart and therefore no blood flow it results in cardiac arrest asystole is found initially in about 28 of people in cardiac arrest asystole is treated by cardiopulmonary resuscitation cpr combined with an intravenous vasopressor such as epinephrine aka adrenaline sometimes an underlying reversible cause can be detected and treated the so called hs and ts an example of which is hypokalaemia several interventions previously recommended — such as defibrillation known to be ineffective on asystole but previously performed in case the rhythm was actually very fine ventricular fibrillation and intravenous atropine — are no longer part of the routine protocols recommended by most major international bodies asystole may be treated with 1 mg epinephrine by iv every 3 – 5 minutes as needed vasopressin 40 units by iv every 3 – 5 minutes may be used in place of the first and or second doses of epinephrine but doing so does not enhance outcomes survival rates in a cardiac arrest patient with asystole are much lower than a patient with a rhythm amenable to defibrillation asystole is itself not a shockable rhythm out of hospital survival rates even with emergency intervention are less than 2 percent
in a variety of computer languages the function atan 2 is the arctangent function with two arguments the purpose of using two arguments instead of one is to gather information on the signs of the inputs in order to return the appropriate quadrant of the computed angle which is not possible for the single argument arctangent function it also avoids the problems of division by zero for any real number e g floating point arguments x and y not both equal to zero atan 2 y x is the angle in radians between the positive x axis of a plane and the point given by the coordinates x y on it the angle is positive for counter clockwise angles upper half plane y 0 and negative for clockwise angles lower half plane y 0
ataque de nervios spanish pronunciation aˈtake ðe ˈnerβjos portuguese ataque de nervos pronounced ɐˈtaki dʒi ˈneʁvus or ɐˈtakɨ ðɨ ˈneɾvuʃ also known as puerto rican syndrome is a psychological syndrome most associated in the united states with spanish speaking people from the caribbean although commonly identified among all iberian descended cultures ataque de nervios translates into english as attack of nerves although it is used in its common cultural form to refer to a specific pattern of symptoms rather than being a general term for feeling nervous the condition appears in appendix i of the revised fourth edition of the diagnostic and statistical manual of mental disorders dsm iv tr as a culture bound syndrome
ataxia telangiectasia a t also referred to as louis – bar syndrome is a rare neurodegenerative autosomal recessive disease causing severe disability ataxia refers to poor coordination and telangiectasia to small dilated blood vessels both of which are hallmarks of the disease a t affects many parts of the body it impairs certain areas of the brain including the cerebellum causing difficulty with movement and coordination it weakens the immune system causing a predisposition to infection it prevents repair of broken dna increasing the risk of cancer symptoms most often first appear in early childhood the toddler stage when children begin to walk though they usually start walking at a normal age they wobble or sway when walking standing still or sitting and may appear almost as if they are drunk in late pre school and early school age they develop difficulty moving their eyes in a natural manner from one place to the next oculomotor apraxia they develop slurred or distorted speech and swallowing problems some have an increased number of respiratory tract infections ear infections sinusitis bronchitis and pneumonia because not all children develop in the same manner or at the same rate it may be some years before a t is properly diagnosed most children with a t have stable neurologic symptoms for the first 4 – 5 years of life but begin to show increasing problems in early school years a t is caused by a defect in the atm gene which is responsible for managing the cell ’ s response to multiple forms of stress including double strand breaks in dna in simple terms the protein produced by the atm gene recognizes that there is a break in dna recruits other proteins to fix the break and stops the cell from making new dna until the repair is complete
ataxic cerebral palsy is clinically observed in approximately 5 10 of all cases of cerebral palsy making it the least frequent form of cerebral palsy diagnosed ataxic cerebral palsy is caused by damage to cerebellar structures differentiating it from the other two forms of cerebral palsy which are spastic cerebral palsy damage to cortical motor areas and underlying white matter and athetoid cerebral palsy damage to basal ganglia because of the damage to the cerebellum which is essential for coordinating muscle movements and balance patients with ataxic cerebral palsy experience problems in coordination specifically in their arms legs and trunk ataxic cerebral palsy is known to decrease muscle tone the most common manifestation of ataxic cerebral palsy is intention action tremor which is especially apparent when carrying out precise movements such as tying shoe laces or writing with a pencil this symptom gets progressively worse as the movement persists causing the hand to shake as the hand gets closer to accomplishing the intended task the trembling intensifies which makes it even more difficult to complete like all forms of cp there is no cure for ataxic cerebral palsy however there are a number of diverse treatments which together have been used to limit the negative effects of the condition like all forms of cp it is most common for ataxic cerebral palsy to be congenital resulting from errors in the development of the cerebellum and connexins during pregnancy however it is also possible to be acquired via meningitis or even by head trauma although the latter more often leads to one of the many forms of traumatic brain injury which is categorically separate from cerebral palsy as a class
ataxic respiration is an abnormal pattern of breathing characterized by complete irregularity of breathing with irregular pauses and increasing periods of apnea as the breathing pattern deteriorates it merges with agonal respirations it is caused by damage to the medulla oblongata due to strokes or trauma it generally indicates a poor prognosis and usually progresses to complete apnea the term is sometimes used interchangeably with biot s respirations
atelectasis is the collapse or closure of a lung resulting in reduced or absent gas exchange it may affect part or all of a lung it is usually not bilateral it is a condition where the alveoli are deflated down to little or no volume as distinct from pulmonary consolidation in which they are filled with liquid it is a very common finding in chest x rays and other radiological studies it may be caused by normal exhalation or by several medical conditions although frequently described as a collapse of lung tissue atelectasis is not synonymous with a pneumothorax which is a more specific condition that features atelectasis acute atelectasis may occur as a post operative complication or as a result of surfactant deficiency in premature neonates this leads to infant respiratory distress syndrome
ateliosis or ateleiosis is a diagnosis used in the early 1900 s to describe patients with short stature ateliosis literally means failure to achieve perfection and was used to describe proportional dwarfism the term was popularised by hastings gilford who used the term to refer to forms of dwarfism associated with and without sexual maturation ateliosis was reported as early as 1904 in relation to progeria a syndrome of premature aging according to the merriam webster dictionary it is “ dwarfism associated with anterior pituitary deficiencies and marked by essentially normal intelligence and proportions though often retarded sexual development ” the physical characteristics include normal facial features childlike high pitched voice proportioned body and abnormal genitalia their mental development is normal to slightly delayed hastings gilford originated the term to describe patients with continuous youth
atelosteogenesis type ii is a severe disorder of cartilage and bone development it is extremely rare and infants with the disorder are usually stillborn however those who survive birth die soon after from respiratory failure
the athabasca oil sands are large deposits of bitumen or extremely heavy crude oil located in northeastern alberta canada – roughly centred on the boomtown of fort mcmurray these oil sands hosted primarily in the mcmurray formation consist of a mixture of crude bitumen a semi solid rock like form of crude oil silica sand clay minerals and water the athabasca deposit is the largest known reservoir of crude bitumen in the world and the largest of three major oil sands deposits in alberta along with the nearby peace river and cold lake deposits the latter stretching into saskatchewan together these oil sand deposits lie under 141 000 square kilometres 54 000 sq mi of boreal forest and muskeg peat bogs and contain about 1 7 trillion barrels 270 × 109 m 3 of bitumen in place comparable in magnitude to the world s total proven reserves of conventional petroleum the international energy agency iea lists the economically recoverable reserves at 2006 prices and modern unconventional oil production technology to be 178 billion barrels 28 3 × 109 m 3 or about 10 of these deposits these contribute to canada s total proven reserves being the third largest in the world after saudi arabia and venezuela s orinoco belt by 2009 the two extraction methods used were in situ extraction when the bitumen occurs deeper within the ground which will account for 80 percent of oil sands development and surface or open pit mining when the bitumen is closer to the surface only 20 percent of bitumen can be extracted using open pit mining methods which involves large scale excavation of the land with huge hydraulic power shovels and 400 ton heavy hauler trucks surface mining leaves toxic tailings ponds in contrast in situ uses more specialized techniques such as steam assisted gravity drainage sagd eighty percent of the oil sands will be developed in situ which accounts for 97 5 percent of the total surface area of the oil sands region in alberta in 2006 the athabasca deposit was the only large oil sands reservoir in the world which was suitable for large scale surface mining although most of this reservoir can only be produced using more recently developed in situ technology critics contend that government and industry measures taken to reduce environmental and health risks posed by large scale mining operations are inadequate causing unacceptable damage to the natural environment and human welfare objective discussion of the environmental impacts has often been clouded by polarized arguments from industry and from advocacy groups
in the dungeons dragons fantasy roleplaying game an athach is a giant like aberration
athelia is the congenital absence of one or both nipples it is a rare condition it sometimes occurs on one side in children with the poland sequence and on both sides in certain types of ectodermal dysplasia
an atheroma plural atheromata or atheromas is an accumulation of degenerative material in the tunica intima inner layer of artery walls the material consists of mostly macrophage cells or debris containing lipids cholesterol and fatty acids calcium and a variable amount of fibrous connective tissue the accumulated material forms a swelling in the artery wall which may intrude into the channel of the artery narrowing it and restricting blood flow atheroma occurs in atherosclerosis which is one of the three subtypes of arteriosclerosis which are atherosclerosis monckeberg s arteriosclerosis and arteriolosclerosis in the context of heart or artery matters atheromata are commonly referred to as atheromatous plaques it is an unhealthy condition found in most humans veins do not develop atheromata unless surgically moved to function as an artery as in bypass surgery the accumulation swelling is always in the tunica intima between the endothelium lining and the smooth muscle tunica media middle layer of the artery wall while the early stages based on gross appearance have traditionally been termed fatty streaks by pathologists they are not composed of fat cells i e adipose cells but of accumulations of white blood cells especially macrophages that have taken up oxidized low density lipoprotein ldl after they accumulate large amounts of cytoplasmic membranes with associated high cholesterol content they are called foam cells when foam cells die their contents are released which attracts more macrophages and creates an extracellular lipid core near the center to inner surface of each atherosclerotic plaque conversely the outer older portions of the plaque become more calcified less metabolically active and more physically stiff over time
atherosclerosis also known as arteriosclerotic vascular disease or asvd is a specific form of arteriosclerosis in which an artery wall thickens as a result of invasion and accumulation of white blood cells wbcs foam cell and proliferation of intimal smooth muscle cell creating a fibrofatty plaque the accumulation of the white blood cells is termed fatty streaks early on because of the appearance being similar to that of marbled steak these accumulations contain both living active wbcs producing inflammation and remnants of dead cells including cholesterol and triglycerides the remnants eventually include calcium and other crystallized materials within the outermost and oldest plaque the fatty streaks reduce the elasticity of the artery walls however they do not affect blood flow for decades because the artery muscular wall enlarges at the locations of plaque the wall stiffening may eventually increase pulse pressure widened pulse pressure is one possible result of advanced disease within the major arteries atherosclerosis is therefore a syndrome affecting arterial blood vessels due to a chronic inflammatory response of wbcs in the walls of arteries this is promoted by low density lipoproteins ldl plasma proteins that carry cholesterol and triglycerides without adequate removal of fats and cholesterol from the macrophages by functional high density lipoproteins hdl it is commonly referred to as a hardening or furring of the arteries it is caused by the formation of multiple atheromatous plaques within the arteries the plaque is divided into three distinct components 1 the atheroma lump of gruel from greek ἀθήρα athera meaning gruel which is the nodular accumulation of a soft flaky yellowish material at the center of large plaques composed of macrophages nearest the lumen of the artery 2 underlying areas of cholesterol crystals 3 calcification at the outer base of older or more advanced lesions atherosclerosis is a chronic disease that remains asymptomatic for decades atherosclerotic lesions or atherosclerotic plaques are separated into two broad categories stable and unstable also called vulnerable the pathobiology of atherosclerotic lesions is very complicated but generally stable atherosclerotic plaques which tend to be asymptomatic are rich in extracellular matrix and smooth muscle cells on the other hand unstable plaques are rich in macrophages and foam cells and the extracellular matrix separating the lesion from the arterial lumen also known as the fibrous cap is usually weak and prone to rupture ruptures of the fibrous cap expose thrombogenic material such as collagen to the circulation and eventually induce thrombus formation in the lumen upon formation intraluminal thrombi can occlude arteries outright e g coronary occlusion but more often they detach move into the circulation and eventually occlude smaller downstream branches causing thromboembolism apart from thromboembolism chronically expanding atherosclerotic lesions can cause complete closure of the lumen chronically expanding lesions are often asymptomatic until lumen stenosis is so severe usually over 80 that blood supply to downstream tissue s is insufficient resulting in ischemia these complications of advanced atherosclerosis are chronic slowly progressive and cumulative most commonly soft plaque suddenly ruptures see vulnerable plaque causing the formation of a thrombus that will rapidly slow or stop blood flow leading to death of the tissues fed by the artery in approximately five minutes this catastrophic event is called an infarction one of the most common recognized scenarios is called coronary thrombosis of a coronary artery causing myocardial infarction a heart attack the same process in an artery to the brain is commonly called stroke another common scenario in very advanced disease is claudication from insufficient blood supply to the legs atherosclerosis affects the entire artery tree but mostly larger high pressure vessels such as the coronary renal femoral cerebral and carotid arteries these are termed clinically silent because the person having the infarction does not notice the problem and does not seek medical help or when they do physicians do not recognize what has happened
athetoid cerebral palsy or dyskinetic cerebral palsy sometimes abbreviated adcp is a type of cerebral palsy primarily associated with damage like other forms of cp to the basal ganglia in the form of lesions that occur during brain development due to bilirubin encephalopathy and hypoxic ischemic brain injury unlike spastic or ataxic cerebral palsies adcp is characterized by both hypertonia and hypotonia due to the affected individual s inability to control muscle tone clinical diagnosis of adcp typically occurs within 18 months of birth and is primarily based upon motor function and neuroimaging techniques while there are no cures for adcp some drug therapies as well as speech occupational therapy and physical therapy have shown capacity for treating the symptoms classification of cerebral palsy can be based on severity topographic distribution or motor function severity is typically assessed via the gross motor function classification system gmfcs or the international classification of functioning disability and health described further below classification based on motor characteristics classifies cp as occurring from damage to either the corticospinal pathway or extrapyramidal regions athetoid dyskinetic cerebral palsy is a non spastic extrapyramidal form of cerebral palsy spastic cerebral palsy in contrast results from damage to the brain ’ s corticospinal pathways non spastic cerebral palsy is divided into two groups ataxic and dyskinetic dyskinetic cerebral palsy is separated further into two different groups choreoathetoid and dystonic choreo athetotic cp is characterized by involuntary movements most predominantly found in the face and extremities dystonic adcp is characterized by slow strong contractions which may occur locally or encompass the whole body clinically physicians have also classified cerebral palsy according to the topographic distribution of muscle spasticity this method classifies children as diplegic bilateral involvement with leg involvement greater than arm involvement hemiplegic unilateral involvement or quadriplegic bilateral involvement with arm involvement equal to or greater than leg involvement
athetosis is a symptom characterized by slow involuntary convoluted writhing movements of the fingers hands toes and feet and in some cases arms legs neck and tongue movements typical of athetosis are sometimes called athetoid movements lesions to the brain are most often the direct cause of the symptoms particularly to the corpus striatum this symptom does not occur alone and is often accompanied by the symptoms of cerebral palsy as it is often a result of this disease treatments for athetosis are not very effective and in most cases are simply aimed at the uncontrollable movement rather than the cause itself
athlete s foot known medically as tinea pedis is a common skin infection of the feet caused by fungus signs and symptoms often include itching scaling and redness in severe cases the skin may blister athlete s foot fungus may infect any part of the foot but most often grows between the toes the next most common area is the bottom of the foot the same fungus may also affect the nails or the hands it is a member of the group of diseases known as tinea tinea pedis is caused by a number of different fungi these include species of trichophyton epidermophyton and microsporum the condition is typically acquired by coming into contact with infected skin or fungus in the environment common places where the fungi can survive are around swimming pools and in locker rooms they may also be spread from other animals usually diagnosis is made based on signs and symptoms however it can be confirmed either by culture or seeing hyphae using a microscope some methods of prevention include avoiding walking barefoot in public showers keeping the toenails short wearing big enough shoes and changing socks daily when infected the feet should be kept dry and clean and wearing sandals may help treatment can be either with antifungal medication applied to the skin such as clotrimazole or for persistent infections antifungal medication that are taken by mouth such as terbinafine the use of the cream is typically recommended for four weeks athletes foot was first medically described in 1908 globally athlete s foot affects about 15 of the population males are more often affected than females it occurs most frequently in older children or younger adults historically it is believed to have been a rare condition that became more frequent in the 1900 s due to the great use of shoes health clubs war and travel
athletic heart syndrome ahs also known as athlete s heart athletic bradycardia or exercise induced cardiomegaly is a nonpathological condition commonly seen in sports medicine in which the human heart is enlarged and the resting heart rate is lower than normal athlete s heart is common in athletes who routinely exercise more than an hour a day and occurs primarily in endurance athletes though it can occasionally arise in heavy weight trainers the condition is generally considered benign but may occasionally hide a serious medical condition or may even be mistaken for one athlete s heart most often does not have any physical symptoms although an indicator would be a consistently low resting heart rate athletes with ahs often do not realize they have the condition unless they undergo specific medical tests because athlete s heart is a normal physiological adaptation of the body to the stresses of physical conditioning and aerobic exercise people diagnosed with athlete ’ s heart commonly display three signs that would usually indicate a heart condition when seen in a regular person bradycardia cardiomegaly and cardiac hypertrophy bradycardia is a slower than normal heartbeat at around 40 – 60 beats per minute cardiomegaly is the state of an enlarged heart and cardiac hypertrophy the thickening of the muscular wall of the heart specifically the left ventricle which pumps oxygenated blood to the aorta especially during an intensive workout more blood and oxygen are required to the peripheral tissues of the arms and legs in highly trained athletes bodies a larger heart results in higher cardiac output which also allows it to beat more slowly as more blood is pumped out with each beat another sign of athlete s heart syndrome is an s 3 gallop which can be heard through a stethoscope this sound can be heard as the diastolic pressure of the irregularly shaped heart creates a disordered blood flow however if an s 4 gallop is heard the patient should be given immediate attention an s 4 gallop is a stronger and louder sound created by the heart if diseased in any way and is typically a sign of a serious medical condition
athletic pubalgia also called sports hernia hockey hernia hockey groin gilmore s groin or groin disruption is a medical condition of the pubic joint affecting athletes it is a syndrome characterized by chronic groin pain in athletes and a dilated superficial ring of the inguinal canal football and ice hockey players are affected most frequently and both recreational and professional athletes may be affected
athymhormia is a disorder of motivation one of that class of neuro psychiatric conditions marked by abnormalities or deficiencies in motivation symptoms include the loss or reduction of desire and interest toward previous motivations loss of drive and the desire for satisfaction curiosity the loss of tastes and preferences and flat affect in athymhormia however these phenomena are not accompanied by the characterizing features of depression nor by any notable abnormality in intellectual or cognitive function
athymhormic syndrome or psychic akinesia is a rare neurological syndrome characterized by extreme passivity apathy blunted affect and a profound generalized loss of self motivation and conscious thought for example a patient with this syndrome might sustain severe burns on contact with a hot stove due to lacking the will to move away despite experiencing severe pain the existence of such symptoms in patients after damage to certain structures in the brain has been used in support of a physical model of motivation in human beings wherein the limbic loop of the basal ganglia is the initiator of directed action and thought the word athymhormic is derived from the greek greek thumos which means mood or affect and greek horme which means impulse drive or appetite first described by french neurologist dominique laplane in 1982 as pap syndrome french perte d auto activation psychique or loss of psychic autoactivation the syndrome is believed to be due to damage to areas of the basal ganglia or frontal cortex specifically the striatum and globus pallidus responsible for motivation and executive functions it may occur without any preexisting psychiatric condition
the atlanta race riot of 1906 was a mass civil disturbance in atlanta georgia united states which began the evening of september 22 and lasted until september 24 1906 it was characterized at the time by le petit journal and other media outlets as a racial massacre of negroes the death toll of the conflict is to this day unknown and disputed but officially at least 25 african americans along with two confirmed european americans unofficial reports ranged from 10 100 african americans and 2 european americans were killed during the riots according to the atlanta history center some african americans were hanged from lamposts during the actual riot the main cause of the race riot was newspaper publicized rapes of four white women in separate incidents allegedly by african american men
the atlantic equatorial mode or atlantic niño is a quasiperiodic interannual climate pattern of the equatorial atlantic ocean it is the dominant mode of year to year variability that results in alternating warming and cooling episodes of sea surface temperatures accompanied by changes in atmospheric circulation the term atlantic niño comes from its close similarity with the el niño southern oscillation enso that dominates the tropical pacific basin the atlantic niño is not the same as the atlantic meridional interhemispheric mode that consists of a north south dipole and operates more on decadal timescales the equatorial warming and cooling events associated with the atlantic niño are known to be strongly related to atmospheric climate anomalies especially in african countries bordering the gulf of guinea therefore understanding of the atlantic niño or lack thereof has important implications for climate prediction in those regions although the atlantic niño is an intrinsic mode to the equatorial atlantic there may be a tenuous causal relationship between enso and the atlantic niño in some circumstances
the atmospheric dynamo is a pattern of electrical currents that are set up in the earth s ionosphere by multiple effects mostly the sun s solar wind but also the tides of the moon and sun the currents flow in circuits between the poles and the equator but they are not well understood
atmospheric electricity is the pattern of electrical charges in the earth s atmosphere or less commonly that of another planet the normal movement of electric charges among the earth s surface the various layers of the atmosphere and especially the ionosphere taken together are known as the global atmospheric electrical circuit much of the reasoning required to explain these currents lies within the field of electrostatics but also requires understanding of other disciplines within earth science eliminating for the moment consideration of the extremely dense charge populations that exist in the upper reaches of the atmosphere a region called the ionosphere filled with hot dense plasma gas whose ions give the ionosphere its name we note that there is always some amount of unbound positive and negative but net positive electric charge in the atmosphere closest to the surface of the negatively charged earth on a fine day when days are not so fine the net unbound charge that exists in the clouds of thunderstorms can be exceedingly negative the fine day net positive charge sets up an electric field between the negative earth and the net positive charge in the air and this electric field stores electrical energy the positive charge acts by induction on the earth and electromagnetic devices experiments have shown that the intensity of this electric field is greater in the middle of the day than at morning or night and is also greater in winter than in summer in fine weather the potential aka voltage increases with altitude at about 30 volts per foot 100 v m when climbing against the gradient of the electric field this electric field gradient continues up into the atmosphere to a point where the voltage reaches its maximum in the neighborhood of 300 000 volts this occurs at approximately 30 – 50 km above the earth s surface from that point in the atmosphere up to its outer limit nearly 1 000 km the electric field gradient produced in the lower atmosphere either ceases or has reversed global daily cycles with a minimum around 03 ut and peaking roughly 16 hours later were researched by the carnegie institution of washington in the 20 th century this carnegie curve variation has been described as the fundamental electrical heartbeat of the planet the phenomena characterizing atmospheric electricity are of at least three kinds there are thunderstorms which create lightning bolts that instantaneously discharge huge amounts of atmospheric charge to ground in a rapid release of energy stored in the electric field that built up to a particularly extreme degree in the storm clouds there is a related phenomenon of continual electrification re charging of the air in the lower atmosphere a third phenomenon is that of the polar auroras most authorities agree that whatever may be the origin of the net unbound positive charge in the atmosphere the generation of enormous currents flow of electrons negative charges that flow between clouds and ground during a lightning discharge begins with condensation of water vapor within the clouds each minute water droplet moving through the air collects upon its surface a certain amount of negative charge by collecting free electrons as these tiny drops coalesce into larger drops and still larger drops there is a corresponding decrease in the total exposed surface upon which the collected electronic charges can be carried raising the negative voltage as droplets combine this is because an object s potential rises as the electrical capacitance of the object holding the charge is decreased the combined negative electric potential of all the coalescing water drops rises until it overcomes the breakdown voltage of the usually non conductive air and jumps to earth as a lightning bolt the similarity of lightning to the discharge of accumulated electrons developed on an electrical machine was demonstrated by franklin in his memorable kite experiments
atmospheric escape is the loss of planetary atmospheric gases to outer space a number of different mechanisms can be responsible for atmospheric escape operating at different time scales the most prominent is jeans escape named after british astronomer sir james jeans who described the process of atmospheric loss to the molecular kinetic energy
atmospheric instability is a condition where the earth s atmosphere is generally considered to be unstable and as a result the weather is subjected to a high degree of variability through distance and time atmospheric stability is a measure of the atmosphere s tendency to encourage or deter vertical motion and vertical motion is directly correlated to different types of weather systems and their severity in unstable conditions a lifted thing such as a parcel of air will be warmer than the surrounding air at altitude because it is warmer it is less dense and is prone to further ascent in meteorology instability can be described by various indices such as the bulk richardson number lifted index k index convective available potential energy cape the showalter and the vertical totals these indices as well as atmospheric instability itself involve temperature changes through the troposphere with height or lapse rate effects of atmospheric instability in moist atmospheres include thunderstorm development which over warm oceans can lead to tropical cyclogenesis and turbulence in dry atmospheres inferior mirages dust devils steam devils and fire whirls can form stable atmospheres can be associated with drizzle fog increased air pollution a lack of turbulence and undular bore formation
atmospheric pressure sometimes also called barometric pressure is the pressure exerted by the weight of air in the atmosphere of earth or that of another planet in most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point low pressure areas have less atmospheric mass above their location whereas high pressure areas have more atmospheric mass above their location likewise as elevation increases there is less overlying atmospheric mass so that atmospheric pressure decreases with increasing elevation on average a column of air one square centimetre cm 2 0 16 sq in in cross section measured from sea level to the top of the atmosphere has a mass of about 1 03 kilograms 2 3 lb and weight of about 10 1 newtons 2 3 lbf that force across one square centimeter is a pressure of 10 1 n cm 2 or 101 000 n m 2 a column 1 square inch 6 5 cm 2 in cross section would have a weight of about 14 7 lb 6 7 kg or about 65 4 n
atmospheric temperature range is the numerical difference between the minimum and maximum values of temperature observed in a given location during a period of time e g in a given day month year century or the average average of all temperature ranges in a period of time the variation in temperature that occurs from the highs of the day to the cool of nights is called diurnal temperature variation
an atmospheric wave is a periodic disturbance in the fields of atmospheric variables like surface pressure or geopotential height temperature or wind velocity which may either propagate traveling wave or not standing wave atmospheric waves range in spatial and temporal scale from large scale planetary waves rossby waves to minute sound waves atmospheric waves with periods which are harmonics of 1 solar day e g 24 hours 12 hours 8 hours etc are known as atmospheric tides
in quantum mechanics an atomic orbital is a mathematical function that describes the wave like behavior of either one electron or a pair of electrons in an atom this function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom s nucleus the term atomic orbital may also refer to the physical region or space where the electron can be calculated to be present as defined by the particular mathematical form of the orbital each orbital in an atom is characterized by a unique set of values of the three quantum numbers n ℓ and m which respectively correspond to the electron s energy angular momentum and an angular momentum vector component the magnetic quantum number each such orbital can be occupied by a maximum of two electrons each with its own spin quantum number s the simple names s orbital p orbital d orbital and f orbital refer to orbitals with angular momentum quantum number ℓ 0 1 2 and 3 respectively these names together with the value of n are used to describe the electron configurations of atoms they are derived from the description by early spectroscopists of certain series of alkali metal spectroscopic lines as sharp principal diffuse and fundamental orbitals for ℓ 3 continue alphabetically omitting j g h i k … atomic orbitals are the basic building blocks of the atomic orbital model alternatively known as the electron cloud or wave mechanics model a modern framework for visualizing the submicroscopic behavior of electrons in matter in this model the electron cloud of a multi electron atom may be seen as being built up in approximation in an electron configuration that is a product of simpler hydrogen like atomic orbitals the repeating periodicity of the blocks of 2 6 10 and 14 elements within sections of the periodic table arises naturally from the total number of electrons that occupy a complete set of s p d and f atomic orbitals respectively although for higher values of the quantum number n particularly when the atom in question bears a positive charge the energies of certain sub shells become very similar and so the order in which they are said to be populated by electrons e g cr ar 4 s 13 d 5 and cr 2 ar 3 d 4 can only be rationalized somewhat arbitrarily
atonic seizures also called drop seizures akinetic seizures or drop attacks are a type of seizure that consist of a brief lapse in muscle tone that are caused by temporary alterations in brain function the seizures are brief usually less than fifteen seconds they begin in childhood and may persist into adulthood the seizure itself causes no damage but the loss of muscle control can result in indirect damage from falling electroencephalography can be used to confirm diagnosis it is rare and can be indicative of lennox gastaut syndrome see henri gastaut atonic seizures can occur while standing walking or sitting and are often noticeable by a head drop the neck muscles relaxing and damage sometimes results from hitting the face or head as with common epileptic occurrences no first aid is needed post seizure except in the instances where falling injuries have occurred in some cases a person may become temporarily paralyzed in part of his or her body this usually does not last longer than 3 minutes
in medicine atony ˈæˌtoʊ ni also atonia is a condition in which a muscle has lost its strength it is frequently associated with the conditions atonic seizure atonic colon uterine atony gastrointestinal atony occurs postoperatively and choreatic atonia atony can also refer to the paralyzed or extremely relaxed state of skeletal muscles in rapid eye movement sleep rem sleep in most warm blooded animals the term atony comes from the ancient greek ἀτονία atonia slackness debility
atopic dermatitis ad also known as atopic eczema is a type of inflammation of the skin dermatitis it results in itchy red swollen and cracked skin clear fluid may come from the affected areas which often thicken over time the condition typically starts in childhood with changing severity over the years in children under one year of age much of the body may be affected as people get older the back of the knees and front of the elbows are the most common areas affected in adults the hands and feet are the most commonly affected areas scratching worsens symptoms and affected people have an increased risk of skin infections many people with atopic dermatitis develop hay fever or asthma the cause is unknown but believed to involve genetics immune system dysfunction environmental exposures and difficulties with the permeability of the skin if one identical twin is affected there is an 85 chance the other also has the condition those who live in cities and dry climates are more commonly affected exposure to certain chemicals or frequent hand washing makes symptoms worse while emotional stress may make the symptoms worse it is not a cause the disorder is not contagious the diagnosis is typically based on the signs and symptoms other diseases that must be excluded before making a diagnosis include contact dermatitis psoriasis and seborrheic dermatitis treatment involves avoiding things that make the condition worse daily bathing with application of a moisturising cream afterwards applying steroid creams when flares occur and medications to help with itchiness things that commonly make it worse include wool clothing soaps perfumes chlorine dust and cigarette smoke phototherapy may be useful in some people steroid pills or creams based on calcineurin inhibitors may occasionally be used if other measures are not effective antibiotics either by mouth or topically may be needed if a bacterial infection develops dietary changes are only needed if food allergies are suspected atopic dermatitis affects about 20 of people at some point in their lives it is more common in younger children males and females are equally affected many people outgrow the condition atopic dermatitis is sometimes called eczema a term that also refers to a larger group of skin conditions other names include infantile eczema flexural eczema prurigo besnier allergic eczema and neurodermatitis
atopy ˈætəpiː from greek ἀτοπία placelessness or atopic syndrome is a predisposition toward developing certain allergic hypersensitivity reactions atopy may have a hereditary component although contact with the allergen or irritant must occur before the hypersensitivity reaction can develop the term atopy was coined by coca and cooke in 1923 many physicians and scientists use the term atopy for any ige mediated reaction even those that are appropriate and proportional to the antigen but many pediatricians reserve the word atopy for a genetically mediated predisposition to an excessive ige reaction
atransferrinemia also called familial hypotransferrinemia is an autosomal recessive metabolic disorder in which there is an absence of transferrin a plasma protein that transports iron through the blood atransferrinemia is characterized by anemia and hemosiderosis in the heart and liver the iron damage to the heart can lead to heart failure the anemia is typically microcytic and hypochromic the red blood cells are abnormally small and pale atransferrinemia is extremely rare with only eight cases documented worldwide
atresia is a condition in which an orifice or passage in the body is usually abnormally closed or absent examples of atresia include imperforate anus malformation of the opening between the rectum and anus microtia absence of the ear canal or failure of the canal to be tubular or fully formed can be related to microtia a congenital deformity of the pinna or outer ear biliary atresia a condition in newborns in which the common bile duct between the liver and the small intestine is blocked or absent choanal atresia blockage of the back of the nasal passage usually by abnormal bony or soft tissue esophageal atresia which affects the alimentary tract and causes the esophagus to end before connecting normally to the stomach intestinal atresia malformation of the intestine usually resulting from a vascular accident in utero ovarian follicle atresia the degeneration and subsequent resorption of one or more immature ovarian follicles pulmonary atresia malformation of the pulmonary valve in which the valve orifice fails to develop tricuspid atresia a form of congenital heart disease whereby there is a complete absence of the tricuspid valve and consequently an absence of the right atrioventricular connection vaginal atresia a congenital occlusion of the vagina or subsequent adhesion of the walls of the vagina resulting in its occlusion renal agenesis only having one kidney potter sequence congenital decreased size of the kidney leading absolutely no functionality of the kidney usually related to a single kidney
atrial fibrillation af or a fib is an abnormal heart rhythm characterized by rapid and irregular beating often it starts as brief periods of abnormal beating which become longer and possibly constant over time most episodes have no symptoms occasionally there may be heart palpitations fainting shortness of breath or chest pain the disease is associated with an increased risk of heart failure dementia and stroke it is a type of supraventricular tachycardia hypertension and valvular heart disease are the most common alterable risk factors for af other heart related risk factors include heart failure coronary artery disease cardiomyopathy and congenital heart disease in the developing world valvular heart disease often occurs as a result of rheumatic fever lung related risk factors include copd obesity and sleep apnea other factors include excess alcohol intake diabetes mellitus and thyrotoxicosis however half of cases are not associated with one of these risks a diagnosis is made by feeling the pulse and may be confirmed using an electrocardiogram ecg a typical ecg in af shows no p waves and an irregular ventricular rate af is often treated with medications to slow the heart rate to a near normal range known as rate control or to convert the rhythm to normal sinus rhythm known as rhythm control electrical cardioversion can also be used to convert af to a normal sinus rhythm and is often used emergently if the person is unstable ablation may prevent recurrence in some people depending on the risk of stroke either aspirin or anti clotting medications such as warfarin or a novel oral anticoagulant may be recommended while these medications reduce this risk they increase rates of major bleeding atrial fibrillation is the most common serious abnormal heart rhythm in europe and north america as of 2014 it affects about 2 to 3 of the population this is an increase from 0 4 to 1 of the population around 2005 in the developing world about 0 6 of males and 0 4 of females are affected the percentage of people with af increases with age with 0 14 under 50 years old 4 between 60 and 70 years old and 14 over 80 years old being affected a fib and atrial flutter resulted in 112 000 deaths in 2013 up from 29 000 in 1990 the first known report of an irregular pulse was by jean baptiste de sénac in 1749 this was first documented by ecg in 1909 by thomas lewis
atrial flutter afl is an abnormal heart rhythm that occurs in the atria of the heart when it first occurs it is usually associated with a fast heart rate or tachycardia beats over 100 per minute and falls into the category of supra ventricular tachycardias while this rhythm occurs most often in individuals with cardiovascular disease e g hypertension coronary artery disease and cardiomyopathy and diabetes mellitus it may occur spontaneously in people with otherwise normal hearts it is typically not a stable rhythm and frequently degenerates into atrial fibrillation af however it does rarely persist for months to years atrial flutter was first identified as an independent medical condition in 1920 by the british physician sir thomas lewis 1881 – 1945 and colleagues
atrial septal defect asd is a congenital heart defect in which blood flows between the atria upper chambers of the heart normally the atria are separated by a dividing wall the interatrial septum if this septum is defective or absent then oxygen rich blood can flow directly from the left side of the heart to mix with the oxygen poor blood in the right side of the heart or vice versa this can lead to lower than normal oxygen levels in the arterial blood that supplies the brain organs and tissues however an asd may not produce noticeable signs or symptoms especially if the defect is small a shunt is the presence of a net flow of blood through the defect either from left to right or right to left the amount of shunting present if any determines the hemodynamic significance of the asd a right to left shunt typically poses the more dangerous scenario during development of the fetus the interatrial septum develops to separate the left and right atria however a hole in the septum called the foramen ovale allows blood from the right atrium to enter the left atrium during fetal development this opening allows blood to bypass the nonfunctional fetal lungs while the fetus obtains its oxygen from the placenta a layer of tissue called the septum primum acts as a valve over the foramen ovale during fetal development after birth the pressure in the right side of the heart drops as the lungs open and begin working causing the foramen ovale to close entirely in approximately 25 of adults the foramen ovale does not entirely seal in these cases any elevation of the pressure in the pulmonary circulatory system due to pulmonary hypertension temporarily while coughing etc can cause the foramen ovale to remain open this is known as a patent foramen ovale pfo a type of atrial septal defect
atrial tachycardia is a type of heart rhythm problem in which the heart s electrical impulse comes from an ectopic pacemaker that is an abnormally located cardiac pacemaker in the upper chambers atria of the heart rather than from the sinoatrial node the normal origin of the heart s electrical activity atrial tachycardias can exhibit very regular consistent heart rates ranging typically from 140 to 220 beats per minute as with any other form of tachycardia rapid heart beat the underlying mechanism can be either the rapid discharge of an abnormal focus the presence of a ring of cardiac tissue that gives rise to a circle movement reentry or a triggered rapid rhythm due to other pathological circumstances as would be the case with some drug toxicities such as digoxin toxicity atrial tachycardia is a risk factor for atrial fibrillation as the rapid rhythm can trigger or degrade into the lack of a rhythm all atrial tachycardias are by definition supraventricular tachycardias forms of atrial tachycardia atach include multifocal atrial tachycardia mat ectopic atrial tachycardia eat unifocal atrial tachycardia uat and paroxysmal atrial tachycardia pat the taxonomy varies somewhat between users regarding names that mean the same versus those that label subsets the codification of the terms first detected paroxysmal persistent and permanent in the classification of atrial fibrillation should be compared for reference
atrichia with papular lesions aka papular atrichia is a diffuse hair loss caused by an abnormality of the human homologue of the mouse hairless gene it is associated with hr
atrioventricular block av block is a type of heart block in which the conduction between the atria and ventricles of the heart is impaired under normal conditions the sinoatrial node sa node in the atria sets the pace for the heart and these impulses travel down to the ventricles in an av block this message does not reach the ventricles or is impaired along the way the ventricles of the heart have their own pacing mechanisms which can maintain a lowered heart rate in the absence of sa stimulation the causes of pathological av block are varied and include ischaemia infarction fibrosis or drugs and the blocks may be complete or may only impair the signaling between the sa and av nodes certain av blocks can also be found as normal variants such as in athletes or children and are benign strong vagal stimulation may also produce av block the cholinergic receptor types affected are the muscarinic receptors there are three types first degree atrioventricular block pr interval greater than 0 20 sec second degree atrioventricular block type 1 aka mobitz 1 wenckebach progressive prolongation of pr interval with dropped beats the pr interval gets longer and longer finally one beat drops type 2 aka mobitz 2 hay pr interval remains unchanged prior to the p wave which suddenly fails to conduct to the ventricles third degree atrioventricular block no association between p waves and qrs complexes sinus rhythm with acute inferior infarction complicated by type i a v block manifest in the form of 5 4 wenckebach periods r p p r reciprocity sinus rhythm rate 100 min with 3 2 and 2 1 type ii a v block rbbb sinus tachycardia with complete a v block and resulting junctional escape
an atrioventricular fistula is a fistula between an atrium and a ventricle of the heart clinically thrills can be felt on the arm of the patient if palpated at the fistula
atrioventricular reentrant tachycardia atrioventricular reciprocating tachycardia or avrt is a supraventricular tachycardia svt most commonly associated with wolff parkinson white syndrome in which an accessory pathway allows electrical signal from the ventricles to enter the atria and cause premature contraction and repeat stimulation of the atrioventricular node
atrioventricular septal defect avsd or atrioventricular canal defect avcd previously known as common atrioventricular canal cavc or endocardial cushion defect is characterized by a deficiency of the atrioventricular septum of the heart it is caused by an abnormal or inadequate fusion of the superior and inferior endocardial cushions with the mid portion of the atrial septum and the muscular portion of the ventricular septum
atrophia maculosa varioliformis cutis amvc is a condition involving spontaneous scarring specifically depressed scars on the face occurring over a period of months to years it appears to only affect children and young adults is considered to be quite rare normally occurs on the cheeks temple area and forehead and is not well understood nor presently treatable case reports indicate the scars deepen over time but remain relatively superficial and with the frequency of new scar appearance diminishing over time amvc is quite difficult to diagnose for reasons including the depressed box and ice pick scars being very similar to that caused by acne vulgaris a confident diagnosis can be made if such scars recently appeared without present acne and without a history of acne otherwise the correct diagnosis is usually not made and even doing so provides little benefit as there is no treatment it has been suggested in case reports that the condition although rare is likely underreported
atrophic connective tissue panniculitis is a rare condition and often occurs on the upper or lower extremities
atrophic gastritis also known as type a or type b gastritis more specifically is a process of chronic inflammation of the stomach mucosa leading to loss of gastric glandular cells and their eventual replacement by intestinal and fibrous tissues as a result the stomach s secretion of essential substances such as hydrochloric acid pepsin and intrinsic factor is impaired leading to digestive problems the most common are vitamin b 12 deficiency which results in a megaloblastic anemia and malabsorbtion of iron leading to iron deficiency anaemia it can be caused by persistent infection with helicobacter pylori or can be autoimmune in origin those with the autoimmune version of atrophic gastritis are statistically more likely to develop gastric carcinoma hashimoto s thyroiditis and achlorhydria type a gastritis primarily affects the body fundus of the stomach and is more common with pernicious anemia type b gastritis primarily affects the antrum and is more common with h pylori infection
atrophic vaginitis also known as vaginal atrophy vulvovaginal atrophy or urogenital atrophy is an inflammation of the vagina and the outer urinary tract due to the thinning and shrinking of the tissues as well as decreased lubrication these symptoms are due to a lack of the reproductive hormone estrogen the most common cause of vaginal atrophy is the decrease in estrogen which happens naturally during perimenopause and increasingly so in post menopause however this condition can occur in other circumstances that result in decreased estrogen such as breastfeeding and the use of medications intended to decrease estrogen to for example treat endometriosis the symptoms can include vaginal soreness and itching as well as painful intercourse and bleeding after sexual intercourse the shrinkage of the tissues and loss of flexibility can be extreme enough to make intercourse impossible
atrophoderma refers to conditions involving skin atrophy types include follicular atrophoderma linear atrophoderma of moulin atrophoderma of pasini and pierini
atrophodermia vermiculata also known as acne vermoulante acne vermoulanti atrophoderma reticulata symmetrica faciei atrophoderma reticulatum atrophoderma vermiculata atrophoderma vermiculatum atrophodermia reticulata symmetrica faciei atrophodermia ulerythematosa atrophodermie vermiculée des joues avec kératoses folliculaires folliculitis ulerythema reticulata folliculitis ulerythematous reticulata folliculitis ulerythemosa honeycomb atrophy ulerythema acneforme and ulerythema acneiforme presents with erythematous follicular papules on the cheeks in childhood and with time the lesions develop into pit like depressions
atrophy is the partial or complete wasting away of a part of the body causes of atrophy include mutations which can destroy the gene to build up the organ poor nourishment poor circulation loss of hormonal support loss of nerve supply to the target organ excessive amount of apoptosis of cells and disuse or lack of exercise or disease intrinsic to the tissue itself in medical practice hormonal and nerve inputs that maintain an organ or body part are said to have trophic effects a diminished muscular trophic condition is designated as atrophy atrophy is the general physiological process of reabsorption and breakdown of tissues involving apoptosis when it occurs as a result of disease or loss of trophic support due to other disease it is termed pathological atrophy although it can be a part of normal body development and homeostasis as well
attention deficit hyperactivity disorder adhd is a mental disorder of the neurodevelopmental type it is characterized by problems paying attention excessive activity or difficulty controlling behavior which is not appropriate for a person s age these symptoms begin by age six to twelve are present for more than six months and cause problems in at least two settings such as school home or recreational activities in children problems paying attention may result in poor school performance although it causes impairment particularly in modern society many children with adhd have a good attention span for tasks they find interesting despite being the most commonly studied and diagnosed mental disorder in children and adolescents the cause is unknown in the majority of cases the world health organization who estimated that it affected about 39 million people as of 2013 it affects about 5 – 7 of children when diagnosed via the dsm iv criteria and 1 – 2 when diagnosed via the icd 10 criteria rates are similar between countries and depend mostly on how it is diagnosed adhd is diagnosed approximately three times more often in boys than in girls about 30 – 50 of people diagnosed in childhood continue to have symptoms into adulthood and between 2 – 5 of adults have the condition the condition can be difficult to tell apart from other disorders as well as to distinguish from high levels of activity that are still within the normal range adhd management recommendations vary by country and usually involve some combination of counseling lifestyle changes and medications the british guideline only recommends medications as a first line treatment in children who have severe symptoms and for medication to be considered in those with moderate symptoms who either refuse or fail to improve with counseling though for adults medications are a first line treatment canadian and american guidelines recommend that medications and behavioral therapy be used together as a first line therapy except in preschool aged children stimulant medication therapy is not recommended as a first line therapy in preschool aged children in either guideline treatment with stimulants is effective for up to 14 months however its long term effectiveness is unclear adolescents and adults tend to develop coping skills which make up for some or all of their impairments the medical literature has described symptoms similar to adhd since the 19 th century adhd its diagnosis and its treatment have been considered controversial since the 1970 s the controversies have involved clinicians teachers policymakers parents and the media topics include adhd s causes and the use of stimulant medications in its treatment most healthcare providers accept adhd as a genuine disorder in children and adults and the debate in the scientific community mainly centers on how it is diagnosed and treated the condition was officially known as attention deficit disorder add from 1980 to 1987 while before this it was known as hyperkinetic reaction of childhood
attention deficit hyperactivity disorder predominantly inattentive adhd pi formerly attention deficit disorder without hyperactivity is one of the three presentations of attention deficit hyperactivity disorder adhd the term was formally changed in 1994 in the diagnostic and statistical manual of mental disorders fourth edition dsm iv to adhd predominantly inattentive adhd pi the predominantly inattentive subtype is similar to the other presentations of adhd except that it is characterized primarily by problems with inattention or a deficit of sustained attention such as procrastination hesitation and forgetfulness it differs in having fewer or no typical symptoms of hyperactivity or impulsiveness lethargy and fatigue are sometimes reported but adhd pi is a separate condition from the proposed cluster of symptoms known as sluggish cognitive tempo sct
attention span is the amount of concentrated time one can spend on a task without becoming distracted most educators such as psychologists agree that the ability to focus attention on a task is crucial for the achievement of one s goals
attentional blink ab is a phenomenon that reflects the temporal costs in the allocating selective attention the ab is typically measured by using rapid serial visual presentation rsvp tasks where participants often fail to detect a second salient target occurring in succession if it is presented between 180 450 ms after the first one also the ab has been observed using two backward masked targets and auditory stimuli the term attentional blink was first used in 1992 although the phenomenon was probably known before
in physics attenuation in some contexts also called extinction is the gradual loss in intensity of any kind of flux through a medium for instance dark glasses attenuate sunlight lead attenuates x rays and water attenuates both light and sound in electrical engineering and telecommunications attenuation affects the propagation of waves and signals in electrical circuits in optical fibers and in air radio waves electrical attenuators and optical attenuators are commonly manufactured components in this field
attitude polarization also known as belief polarization and polarization effect is a phenomenon in which a disagreement becomes more extreme as the different parties consider evidence on the issue it is one of the effects of confirmation bias the tendency of people to search for and interpret evidence selectively to reinforce their current beliefs or attitudes when people encounter ambiguous evidence this bias can potentially result in each of them interpreting it as in support of their existing attitudes widening rather than narrowing the disagreement between them the effect is observed with issues that activate emotions such as political hot button issues for most issues new evidence does not produce a polarization effect for those issues where polarization is found mere thinking about the issue without contemplating new evidence produces the effect social comparison processes have also been invoked as an explanation for the effect which is increased by settings in which people repeat and validate each other s statements this apparent tendency is of interest not only to psychologists but also to sociologists and philosophers
in epidemiology attributable risk or excess risk is the difference in rate of a condition between an exposed population and an unexposed population attributable risk is mostly calculated in cohort studies where individuals are assembled on exposure status and followed over a period of time investigators count the occurrence of the diseases the cohort is then subdivided by the level of exposure and the frequency of disease is compared between subgroups one is considered exposed and another unexposed the formula commonly used in epidemiology books for attributable risk is ie iu ar where ie incidence in exposed and iu incidence in unexposed once the ar is calculated then the ar percent can be determined the formula for that is 100 ie iu ie population attributable risk par is the reduction in incidence that would be observed if the population were entirely unexposed compared with its current actual exposure pattern the concept was first proposed by levin in 1953
atypical adenomatous hyperplasia is a subtype of pneumocytic hyperplasia in the lung it can be a precursor lesion of in situ adenocarcinoma of the lung bronchioloalveolar carcinoma in prostate tissue biopsy it can be confused for adenocarcinoma of the prostate the needle biopsy rate is less than 1
atypical chronic myeloid leukemia acml is a type of leukemia it is a heterogeneous disorder belonging to the group of myelodysplastic myeloproliferative mds mpn syndromes in acml many clinical features splenomegaly myeloid predominance in the bone marrow with some dysplastic features but without a differentiation block and laboratory abnormalities myeloid proliferation low leukocyte alkaline phosphatase values suggest the diagnosis of chronic myelogenous leukemia cml however the lack of the pathognomonic philadelphia chromosome and of the resulting bcr abl 1 fusion point to a different pathogenetic process since no specific recurrent genomic or karyotypic abnormalities have been identified in acml the molecular pathogenesis of this disease has remained elusive and the outcome dismal median survival 37 months with no improvement over the last 20 years this sharply contrasts with the outcome for cml for which the prognosis was dramatically improved by the development of imatinib as a specific inhibitor of the bcr abl protein and in particular for cml in 2012 setbp 1 was identified as a novel oncogene in acml specific somatic mutations of this gene were discovered in people with acml and related diseases these mutations which are identical to the ones present in sgs as germline mutations impair the degradation of setbp 1 and therefore cause increased cellular levels of the protein
atypical depression or depression with atypical features as it has been known in the dsm iv is depression that shares many of the typical symptoms of the psychiatric syndromes major depression or dysthymia but is characterized by improved mood in response to positive events in contrast people with melancholic depression generally do not experience an improved mood in response to normally pleasurable events atypical depression also features significant weight gain or an increased appetite hypersomnia a heavy sensation in the limbs and interpersonal rejection sensitivity that results in significant social or occupational impairment despite its name atypical depression does not mean it is uncommon or unusual the reason for its name is twofold 1 it was identified with its unique symptoms subsequent to the identification of melancholic depression and 2 its responses to the two different classes of antidepressants that were available at the time were different from melancholic depression i e maois had clinically significant benefits for atypical depression while tricyclics did not atypical depression is two to three times more common in women than in men individuals with atypical features tend to report an earlier age of onset e g while in high school of their depressive episodes which also tend to be more chronic and only have partial remission between episodes younger individuals may be more likely to have atypical features whereas older individuals may more often have episodes with melancholic features atypical depression has high comorbidity of anxiety disorders carries more risk of suicidal behavior and has distinct personality psychopathology and biological traits atypical depression is more common in individuals with bipolar i bipolar ii cyclothymia and seasonal affective disorder depressive episodes in bipolar disorder tend to have atypical features as does depression with seasonal patterns
atypical ductal hyperplasia abbreviated adh is the term used for a benign lesion of the breast that indicates an increased risk of breast cancer the name of the entity is descriptive of the lesion adh is characterized by cellular proliferation hyperplasia within one or two breast ducts and histomorphologic architectural abnormalities i e the cells are arranged in an abnormal or atypical way in the context of a core needle biopsy adh is considered an indication for a breast lumpectomy also known as a surgical excisional biopsy to exclude the presence of breast cancer
atypical facial pain afp also termed atypical facial neuralgia chronic idiopathic facial pain or psychogenic facial pain is a type of chronic facial pain which does not fulfill any other diagnosis there is no consensus as to a globally accepted definition and there is even controversy as to whether the term should be continued to be used both the international headache society ihs and the international association for the study of pain iasp have adopted the term persistent idiopathic facial pain pifp to replace afp in the 2 nd edition of the international classification of headache disorders ichd 2 pifp is defined as persistent facial pain that does not have the characteristics of the cranial neuralgias and is not attributed to another disorder however the term afp continues to be used by the world health organization s 10 th revision of the international statistical classification of diseases and related health problems and remains in general use by clinicians to refer to chronic facial pain that does not meet any diagnostic criteria and does not respond to most treatments the main features of afp are no objective signs negative results with all investigations tests no obvious explanation for the cause of the pain and a poor response to attempted treatments afp has been described variably as a medically unexplained symptom a diagnosis of exclusion a psychogenic cause of pain e g a manifestation of somatoform disorder and as a neuropathy afp is usually burning and continuous in nature and may last for many years depression and anxiety are often associated with afp which are either described as a contributing cause of the pain or the emotional consequences of suffering with unrelieved chronic pain for unknown reasons afp is significantly more common in middle aged or elderly people and in females atypical odontalgia ao also termed phantom tooth pain psychogenic toothache or persistent dentoalveolar pain disorder is very similar in many respects to afp with some sources treating them as the same entity and others describing the former as a sub type of afp generally the term ao may be used where the pain is confined to the teeth or gums and afp when the pain involves other parts of the face as with afp there is a similar lack of standardization of terms and no consensus regarding a globally accepted definition surrounding ao generally definitions of ao state that it is pain with no demonstrable cause which is perceived to be coming from a tooth or multiple teeth and is not relieved by standard treatments to alleviate dental pain depending upon the exact presentation of atypical facial pain and atypical odontalgia it could be considered as craniofacial pain or orofacial pain it has been suggested that in truth afp and ao are umbrella terms for a heterogenous group of misdiagnosed or not yet fully understood conditions and they are unlikely to each represent a single discrete condition
atypical fibroxanthoma of the skin is a low grade malignancy related to malignant fibrous histiocytoma which it resembles histologically
atypical hemolytic uremic syndrome ahus is an extremely rare life threatening progressive disease that frequently has a genetic component in most cases it is caused by chronic uncontrolled activation of the complement system a branch of the body ’ s immune system that destroys and removes foreign particles the disease affects both children and adults and is characterized by systemic thrombotic microangiopathy tma the formation of blood clots in small blood vessels throughout the body which can lead to stroke heart attack kidney failure and death the complement system activation may be due to mutations in the complement regulatory proteins factor h factor i or membrane cofactor protein or is occasionally due to acquired neutralizing autoantibody inhibitors of these complement system components for example anti – factor h antibodies despite the use of supportive care historically an estimated 33 – 40 of patients died or developed end stage renal disease esrd with the first clinical bout of ahus including subsequent relapses a total of approximately two thirds 65 of patients died required dialysis or had permanent renal damage within the first year after diagnosis despite plasma exchange or plasma infusion pe pi
atypical hyperplasia is a benign noncancerous cellular hyperplasia in which cells show some atypia in this condition cells look abnormal under a microscope and are increased in number
atypical lichen myxedematosus also known as intermediate lichen myxedematosus is a skin condition caused by fibroblasts producing abnormally large amounts of mucopolysaccharides
atypical pneumonia also known as walking pneumonia is the type of pneumonia not caused by one of the more traditional pathogens its clinical presentation contrasts to that of typical pneumonia a variety of microorganisms can cause it when it develops independently from another disease it is called primary atypical pneumonia pap the term was introduced in the 1930 sand was contrasted with the bacterial pneumonia caused by streptococcus pneumoniae at that time the best known and most commonly occurring form of pneumonia the distinction was historically considered important as it differentiated those more likely to present with typical respiratory symptoms and lobar pneumonia from those more likely to present with atypical generalized symptoms such as fever headache sweating and myalgia and bronchopneumonia distinction between atypical and typical pneumonia is however medically insufficient for the treatment of pneumonia it is important to know the exact causal organism
atypical polypoid adenomyoma abbreviated apa is a rare uncommon benign tumour of the uterus
atypical pulmonary carcinoid tumour is a subtype of pulmonary carcinoid tumor it is an uncommon low grade malignant lung mass that is most often in the central airways of the lung it is also known as atypical lung carcinoid tumour atypical lung carcinoid or moderately differentiated neuroendocrine carcinoma it is a more aggressive than typical carcinoid tumors nodal metastases in 70 vs 5 the 5 year survival is 49 69 atypical carcinoid tumors have increased mitotic activity 2 10 per 10 hpf nuclear pleomorphism or foci of necrosis
in urologic pathology atypical small acinar proliferation abbreviated asap is a collection of small prostatic glands on prostate biopsy whose significance is uncertain and cannot be determined to be benign or malignant asap generally is not considered a pre malignancy or a carcinoma in situ it is an expression of diagnostic uncertainty and analogous to the diagnosis of ascus atypical squamous cells of undetermined significance on the pap test
atypical teratoid rhabdoid tumor at rt is a rare tumor usually diagnosed in childhood although usually a brain tumor at rt can occur anywhere in the central nervous system cns including the spinal cord about 60 will be in the posterior cranial fossa particularly the cerebellum one review estimated 52 posterior fossa 39 spnet supratentorial primitive neuroectodermal tumors 5 pineal 2 spinal and 2 multi focal in the united states three children per 1 000 000 or around 30 new at rt cases are diagnosed each year at rt represents around 3 of pediatric cancers of the cns around 17 of all pediatric cancers involve the cns it is the most common childhood solid tumor the survival rate for cns tumors is around 60 pediatric brain cancer is the second leading cause of childhood death just after leukemia recent trends suggest that the rate of overall cns tumor diagnosis is increasing by about 2 7 per year as diagnostic techniques using genetic markers improve and are used more often the proportion of at rt diagnoses is expected to increase at rt was only recognized as an entity in 1996 and added to the world health organization who brain tumor classification in 2000 grade iv the relatively recent classification and rarity has contributed to initial misdiagnosis and non optimal therapy this has led to a historically poor prognosis current research is focusing on using chemotherapy protocols that are effective against rhabdomyosarcoma in combination with surgery and radiation therapy recent studies using multi modal therapy have shown significantly improved survival data in 2008 the dana farber cancer institute in boston reported two year overall survival of 53 and event free survival of 70 median age at diagnosis of 26 months in 2013 the medical university of vienna reported five year overall survival of 100 and event free survival of 89 median age at diagnosis of 24 months survival rates can be significantly improved when the correct genetic diagnosis is made at the outset followed with specific multi modal treatment
atypical trigeminal neuralgia atn or type 2 trigeminal neuralgia is a form of trigeminal neuralgia a disorder of the fifth cranial nerve this form of nerve pain is difficult to diagnose as it is rare and the symptoms overlap with several other disorders the symptoms can occur in addition to having migraine headache or can be mistaken for migraine alone or dental problems such as temporomandibular joint disorder musculoskeletal issues or hypochondriasis atn can have a wide range of symptoms and the pain can fluctuate in intensity from mild aching to a crushing or burning sensation and also to the extreme pain experienced with the more common trigeminal neuralgia
atypical tuberous myxedema also known as jadassohn – dosseker syndrome is thought to represent a pure nodular variant of lichen myxedematosus
audio signal processing or audio processing is the intentional alteration of audio signals often through an audio effect or effects unit as audio signals may be electronically represented in either digital or analog format signal processing may occur in either domain analog processors operate directly on the electrical signal while digital processors operate mathematically on the digital representation of that signal
a paracusia or auditory hallucination is a form of hallucination that involves perceiving sounds without auditory stimulus auditory hallucinations need to be distinguished from endaural phenomena in which sounds are heard without any external acoustic stimulation but arise from disorders of the frontal lobe temporal lobe language processing system ear or auditory system a common form of auditory hallucination involves hearing one or more talking voices this may be associated with psychotic disorders and holds special significance in diagnosing these conditions however individuals without any psychiatric disease whatsoever may hear voices there are three main categories into which the hearing of talking voices often fall a person hearing a voice speak one s thoughts a person hearing one or more voices arguing or a person hearing a voice narrating his her own actions these three categories do not account for all types of auditory hallucinations other types of auditory hallucination include exploding head syndrome and musical ear syndrome in the latter people will hear music playing in their mind usually songs they are familiar with this can be caused by lesions on the brain stem often resulting from a stroke also sleep disorders such as narcolepsy tumors encephalitis or abscesses this should be distinguished from the commonly experienced phenomenon of getting a song stuck in one s head reports have also mentioned that it is also possible to get musical hallucinations from listening to music for long periods of time other reasons include hearing loss and epileptic activity
auditory processing disorder apd also known as central auditory processing disorder capd is an umbrella term for a variety of disorders that affect the way the brain processes auditory information individuals with apd usually have normal structure and function of the outer middle and inner ear peripheral hearing however they cannot process the information they hear in the same way as others do which leads to difficulties in recognizing and interpreting sounds especially the sounds composing speech it is thought that these difficulties arise from dysfunction in the central nervous system the american academy of audiology notes that apd is diagnosed by difficulties in one or more auditory processes known to reflect the function of the central auditory nervous system apd can affect both children and adults although the actual prevalence is currently unknown it has been suggested that males are twice as likely to be affected by the disorder as females but there are no good epidemiological studies
the auger effect is a physical phenomenon in which the filling of an inner shell vacancy of an atom is accompanied by the emission of an electron from the same atom when a core electron is removed leaving a vacancy an electron from a higher energy level may fall into the vacancy resulting in a release of energy although most often this energy is released in the form of an emitted photon the energy can also be transferred to another electron which is ejected from the atom this second ejected electron is called an auger electron the effect was first discovered by lise meitner in 1922 pierre victor auger independently discovered the effect shortly after and is credited with the discovery in most of the scientific community upon ejection the kinetic energy of the auger electron corresponds to the difference between the energy of the initial electronic transition into the vacancy and the ionization energy for the electron shell from which the auger electron was ejected these energy levels depend on the type of atom and the chemical environment in which the atom was located auger electron spectroscopy involves the emission of auger electrons by bombarding a sample with either x rays or energetic electrons and measures the intensity of auger electrons that result as a function of the auger electron energy the resulting spectra can be used to determine the identity of the emitting atoms and some information about their environment auger recombination is a similar auger effect which occurs in semiconductors an electron and electron hole electron hole pair can recombine giving up their energy to an electron in the conduction band increasing its energy the reverse effect is known as impact ionization
in music an augmented triad is a triad or chord consisting of two major thirds an augmented fifth the term augmented triad arises from an augmented triad being considered a major chord whose top note fifth is raised or augmented it can be represented by the integer notation 0 4 8
the august curse is a perceived phenomenon in russia in which tragic events are felt to occur unusually often in the month of august many possible explanations have been presented for the phenomenon
an aura is a perceptual disturbance experienced by some with migraines or seizures before either the headache or seizure begins it often manifests as the perception of a strange light an unpleasant smell or confusing thoughts or experiences some people experience aura without a subsequent migraine or seizure see silent migraine auras vary by individual experience some people experience smells lights or hallucinations less known symptoms of the eye include disturbances where the eyes roll in the back of the head caused by photosensitivity a sufferer of this type of aura may experience tearfulness of the eyes and uncontrollable sensations of light followed by reduced symptoms after approximately 20 minutes it is the rarest type of aura when occurring auras allow people who have epilepsy time to prevent injury to themselves and or others the time between the appearance of the aura and the migraine lasts from a few seconds up to an hour the aura can stay with a migraine sufferer for the duration of the migraine depending on the type of aura it can leave the person disoriented and confused it is not uncommon for migraine sufferers to experience more than one type of aura during the migraine most people who have auras have the same type of aura every time auras can also be confused with sudden onset of panic panic attacks or anxiety attacks creating difficulties in diagnosis the differential diagnosis of patients who experience symptoms of paresthesias derealization dizziness chest pain tremors and palpitations can be quite challenging
the aureole effect or water aureole is an optical phenomenon similar to heiligenschein creating sparkling light and dark rays radiating from the shadow of the viewer s head this effect is seen only over a rippling water surface the waves act as lenses to focus and defocus sunlight focused sunlight produces the lighter rays while defocused sunlight produces the darker rays suspended particles in the water help make the aureole effect more pronounced the effect extends a greater angular distance from the viewer s shadow when the viewer is higher above the water and can sometimes be seen from a plane although the focused light ray cones are actually more or less parallel to each other the rays from the aureole effect appear to be radiating from the shadow of the viewer ’ s head due to perspective effects the viewer s line of sight is parallel and lies within the cones so from the viewer s perspective the rays seem to be radiating from the antisolar point within the viewer s shadow as in similar antisolar optical effects such as a glory or heiligenschein each observer will see an aureole effect radiating only from their own head ’ s shadow similarly if a photographer holds their camera at arm s length the aureole effect appearing in the picture will be seen radiating from the shadow of the camera although the photographer would still see it around their head s shadow while taking the picture this happens because the aureole effect always appears directly opposite the sun centered at the antisolar point the antisolar point itself is located within the shadow of the viewer whatever this is the eyes of the viewer or the camera s lens as a matter of fact when aureole effects are photographed from a plane it is possible to tell where the photographer was seated
auricular hypertrichosis hypertrichosis lanuginosa acquisita hypertrichosis pinnae auris is a genetic condition expressed as long and strong hairs growing from the helix of the pinna
auspitz s sign is the appearance of punctate bleeding spots when psoriasis scales are scraped off named after heinrich auspitz this happens because there is thinning of the epidermal layer overlying the tips of the dermal papillae and blood vessels within the papillae are dilated and tortuous which bleed readily when the scale is removed
the australian multicam camouflage uniform amcu is the battledress camouflage pattern for the australian defence force issued in 2014 the amcu replaced the previously used disruptive pattern combat uniform and australian multicam pattern operational combat uniform camouflage patterns
during the australian gold rushes significant numbers of workers both from other areas within australia and from overseas relocated to areas in which gold had been discovered a number of gold finds occurred in australia prior to 1851 but only the gold found from 1851 onwards created gold rushes this is mainly because prior to 1851 the colonial government of new south wales victoria did not become a separate colony until 1 july 1851 and tasmania did not become a separate colony until 1856 had suppressed news of gold finds which it believed would reduce the workforce and destabilise the economy after the california gold rush began in 1848 causing many people to leave australia for california to look for gold there the new south wales government rethought its position and sought approval from the colonial office in england to allow the exploitation of the mineral resources and also offered rewards for the finding of payable gold the first gold rush in australia began in may 1851 after prospector edward hargraves claimed to have discovered payable gold near orange at a site he called ophir hargraves had been to the californian goldfields and had learned new gold prospecting techniques such as panning and cradling hargraves was offered rewards by the colony of new south wales and the colony of victoria before the end of the year the gold rush had spread to many other parts of the state where gold had been found not just to the west but also to the south and north of sydney the australian gold rushes changed the convict colonies into more progressive cities with the influx of free emigrants these hopefuls termed diggers brought new skills and professions contributing to a burgeoning economy the mateship that evolved between these diggers and their collective resistance to authority led to the emergence of a unique national identity although not all diggers found riches on the goldfields many decided to stay and integrate into these communities in july 1851 victoria s first gold rush began on the clunes goldfield in august the gold rush had spread to include the goldfield at buninyong today a suburb of ballarat 45 km 28 m away and by early september 1851 to the nearby goldfield at ballarat then also known as yuille s diggings followed in early september to the goldfield at castlemaine then known as forest creek and the mount alexander goldfield and the goldfield at bendigo then known as bendigo creek in november 1851 gold just as in new south wales was also found in many other parts of the state the victorian gold discovery committee wrote in 1854 the discovery of the victorian goldfields has converted a remote dependency into a country of world wide fame it has attracted a population extraordinary in number with unprecedented rapidity it has enhanced the value of property to an enormous extent it has made this the richest country in the world and in less than three years it has done for this colony the work of in age and made its impulses felt in the most distant regions of the earth when the rush began at ballarat diggers discovered it was a prosperous goldfield lieutenant governor charles la trobe visited the site and watched five men uncover 136 ounces of gold in one day mount alexander was even more rich than ballarat with gold sitting just under the surface the shallowness allowed diggers to easily unearth gold nuggets in 7 months 2 4 million pounds of gold was transported from mount alexander to nearby capital cities the gold rushes caused a huge influx of people from overseas australia s total population more than tripled from 430 000 in 1851 to 1 7 million in 1871 australia first became a multicultural society during the gold rush period between 1852 and 1860 290 000 people migrated to victoria from the british isles 15 000 came from other european countries and 18 000 emigrated from the united states non european immigrants however were unwelcome especially the chinese the chinese were particularly industrious with techniques that differed widely from the europeans this and their physical appearance and fear of the unknown led to them to being persecuted in a racist way that would be regarded as untenable today in 1855 11 493 chinese arrived in melbourne chinese travelling outside of new south wales had to obtain special re entry certificates in 1855 victoria enacted the chinese immigration act 1855 severely limiting the number of chinese passengers permitted on an arriving vessel to evade the new law many chinese were landed in the south east of south australia and travelled more than 400 km across country to the victorian goldfields along tracks which are still evident today in 1885 following a call by the western australian government for a reward for the first find of payable gold a discovery was made at halls creek sparking a gold rush in that state
the australian government debt is the amount owed by the australian federal government the australian office of financial management which is part of the treasury portfolio is the agency which manages the government debt and does all the borrowing on behalf of the australian government australian government borrowings are subject to limits and regulation by the loan council unless if the borrowing is for defence purposes or is a temporary borrowing government debt and borrowings and repayments have national macroeconomic implications and are also used as one of the tools available to the national government in the macroeconomic management of the national economy enabling the government to create or dampen liquidity in financial markets with flow on effects on the wider economy as of 27 february 2014 the gross australian government debt was a 300 63 billion at 15 august 2014 it was a 326 55 billion and at 13 march 2015 it was 361 09 billion an increase of aud 2 05 billion from 6 march 2015 at 22 january 2016 it was a 405 988 billion the government debt fluctuates from week to week depending on government receipts general outlays and large sum outlays australian government debt does not take into account government funds held in reserve within statutory authorities such as the australian government future fund which at 30 september 2015 was valued at a 117 83 billion and the reserve bank of australia nor is the net income of these statutory authorities taken into account for example the future fund net income in 2014 15 was a 15 61 billion which went directly into the fund s reserves also guarantees offered by the government do not figure in the government debt level for example on october 12 2008 in response to the economic crisis of 2008 the government offered to guarantee 100 of all bank deposits this was subsequently reduced to a maximum of 1 million per customer per institution from 1 february 2012 the guarantee was reduced to 250 000 and is ongoing australia s net international investment liability position government debt and private debt was a 922 8 billion at 30 september 2015 an increase of a 18 2 billion 2 on the liability position at 30 june 2015 according to the australian bureau of statistics australia s bond credit rating was rated aaa by all three major credit rating agencies as at december 2012 at the time of the 2015 budget the treasurer discounted any chance of a rating downgrade around two thirds of australian government debt is held by non resident investors a share that has risen since 2009 and remains historically high
austrian syndrome is a medical condition first described by robert austrian in 1957 the classical triad consists of pneumonia endocarditis and meningitis all caused by streptococcus pneumoniae it is associated with alcoholism due to the presence of hyposplenia reduced splenic functioning and can be seen in males between 40 and 60 years old
the authorised capital of a company sometimes referred to as the authorised share capital registered capital or nominal capital particularly in the united states is the maximum amount of share capital that the company is authorised by its constitutional documents to issue allocate to shareholders part of the authorised capital can and frequently does remain unissued the authorised capital can be changed with shareholders approval the part of the authorised capital which has been issued to shareholders is referred to as the issued share capital of the company the device of the authorised capital is used to limit or control the ability of the directors to issue or allot new shares which may have consequences in the control of a company or otherwise alter the balance of control between shareholders such an issue of shares to new shareholders may also shift the profit distribution balance for example if new shares are issued at face value and not at market value the requirement for a company to have a set authorised capital was abolished in australia in 2001 and in the united kingdom it was abolished under the companies act 2006
authorization or authorisation is the function of specifying access rights to resources related to information security and computer security in general and to access control in particular more formally to authorize is to define an access policy for example human resources staff is normally authorized to access employee records and this policy is usually formalized as access control rules in a computer system during operation the system uses the access control rules to decide whether access requests from authenticated consumers shall be approved granted or disapproved rejected resources include individual files or an item s data computer programs computer devices and functionality provided by computer applications examples of consumers are computer users computer programs and other devices on the computer
autism is a neurodevelopmental disorder characterized by impaired social interaction verbal and non verbal communication and restricted and repetitive behavior parents usually notice signs in the first two years of their child s life these signs often develop gradually though some children with autism reach their developmental milestones at a normal pace and then regress the diagnostic criteria require that symptoms become apparent in early childhood typically before age three while autism is highly heritable researchers suspect both environmental and genetic factors as causes in rare cases autism is strongly associated with agents that cause birth defects controversies surround other proposed environmental causes for example the vaccine hypotheses which have since been disproven autism affects information processing in the brain by altering how nerve cells and their synapses connect and organize how this occurs is not well understood in the dsm v it is one of three recognized disorders in the autism spectrum asds the other two being asperger syndrome which lacks delays in cognitive development and language and pervasive developmental disorder not otherwise specified commonly abbreviated as pdd nos which is diagnosed when the full set of criteria for autism or asperger syndrome are not met early speech or behavioral interventions can help children with autism gain self care social and communication skills although there is no known cure there have been reported cases of children who recovered not many children with autism live independently after reaching adulthood though some become successful an autistic culture has developed with some individuals seeking a cure and others believing autism should be accepted as a difference and not treated as a disorder globally autism is estimated to affect 21 7 million people as of 2013 as of 2010 the number of people affected is estimated at about 1 – 2 per 1 000 worldwide it occurs four to five times more often in boys than girls about 1 5 of children in the united states one in 68 are diagnosed with asd as of 2014 a 30 increase from one in 88 in 2012 the rate of autism among adults aged 18 years and over in the united kingdom is 1 1 the number of people diagnosed has been increasing dramatically since the 1980 s partly due to changes in diagnostic practice and government subsidized financial incentives for named diagnoses the question of whether actual rates have increased is unresolved
the term autism spectrum or autism spectrum disorder describes a range of conditions classified as neurodevelopmental disorders in the fifth and most recent revision of the american psychiatric association s diagnostic and statistical manual of mental disorders dsm 5 published in 2013 individuals diagnosed with autism spectrum disorder must present two types of symptoms deficits in social communication and social interaction restricted repetitive patterns of behavior interests or activities the dsm 5 redefined the autism spectrum disorders to encompass the previous dsm iv tr diagnoses of autism asperger syndrome pervasive developmental disorder not otherwise specified pdd nos and childhood disintegrative disorder features of these disorders include social deficits and communication difficulties stereotyped or repetitive behaviors and interests sensory issues and in some cases cognitive delays
autistic enterocolitis is the name of a nonexistent medical condition proposed by discredited british gastroenterologist andrew wakefield when he suggested a link between a number of common clinical symptoms and signs which he contended were distinctive to autism the existence of such an enterocolitis has been dismissed by experts as having not been established wakefield s now retracted and fraudulent report used inadequate controls and suppressed negative findings and multiple attempts to replicate his results have been unsuccessful reviews in the medical literature have found no link between the mmr vaccine and autism or with bowel disease most of wakefield s coauthors later retracted the conclusions of the original paper proposing the hypothesis and the general medical council found wakefield guilty of manipulating patient data and misreporting results his work has been exposed as falsified and described as an elaborate fraud
auto brewery syndrome also known as gut fermentation syndrome is a rare medical condition in which intoxicating quantities of ethanol are produced through endogenous fermentation within the digestive system one gastrointestinal organism saccharomyces cerevisiae a type of yeast has been identified as a pathogen for this condition claims of endogenous fermentation of this type have been used as a defense against drunk driving charges one case went undetected for 20 years it has also been investigated but eliminated as a possible cause of sudden infant death syndrome a variant occurs in persons with liver abnormalities that prevent them from excreting or breaking down alcohol normally patients with this condition can develop symptoms of auto brewery syndrome even when the gut yeast produces a quantity of alcohol that is too small to intoxicate a healthy individual
auto segregation or self segregation is the separation of a religious or ethnic group from the rest of society in a state by the group itself this could also mean inability for a normal social interaction and a form of social exclusion through auto segregation the members of the separate group can establish their own services and maintain their own traditions and customs for example some of the world s uncontacted peoples have preferred not to interact with the rest of the globally integrated human population by remaining in a reserve and in isolation they can preserve their cultures intact as long as they choose and the surrounding states protect them on the other hand some groups self segregate to avoid integrating with other groups either to protect their culture or some may self segregate from others that they consider intellectually and or socially inferior nationalists non racists or racists ultranationalists different hindu castes and other supremacist or ethno centric groups commonly segregate themselves from other communities through various practices like endogamy the apartheid system in south africa was an example of this trend
auto independence is the ability to get around without having to own a car it can also be called carfree mobility an auto independent or carfree society has at least five options of travel these include at least the following 1 a system of buses trains and aircraft for passengers to travel from town to town reliably and safely 2 availability of car rental by the hour or more if the driver has a valid driving license 3 availability of convenient economical fast reliable safe transport without driving oneself 4 safe reliable mass public transit 5 shuttle service in large high traffic areas such as shopping malls and city centers currently many towns in the u s have no public transport and walking and bicycling is not practical because of time and physical constraints where public transportation is available it may not be close enough to access without a car or the schedules are not compatible with the schedule of the rider for long distances e g new york city to chicago personal accommodations of scheduling is not too difficult to go from rockville maryland to alexandria virginia mass transit is not available at all times and not convenient unless the rider is close to the metrorail station going to a destination that is close to another metrorail station if the rider has a car or other means to get to the station of origin s he would still have to find a means to get from the station to the desired destination a ridesharing service with a communication system that could handle the riders requirements fast enough is possible such a ridesharing service would only be attractive to a market if it could assure the ride of quality service airline reservation systems provide this service for air travel because those systems are expensive they have never been adopted by bus companies for interurban travel less expensive systems can be set up if they are limited to a region and a time frame for these systems matching origins and destinations is different from the process for a system to meet the needs of the third designated system above mass public transit could better serve the public if it used the usage data available at its entry and exit gates some public mass transit systems do not keep track of exiting passengers the lack of such data makes it more difficult to determine how to run the trains when the coming and going data is known the scheduling can be more precisely matched to the need public mass transit thinks always in terms of the number of trains to run and not in terms of the precision of timing
text replacement replace as you type or autocorrect is an automatic data validation function commonly found in word processors and text editing interfaces for smartphones and tablet computers its principal purpose is as part of the spell checker to correct common spelling or typing errors saving time for the user it is also used to automatically format text or insert special characters by recognizing particular character usage saving the user from having to use more tedious functions additional options include recognizing words with two initial capital letters e g example and correcting them capitalizing the first letters of sentences and correcting accidental use of caps lock e g example the replacement list for text replacement can also be modified by the user allowing the user to use shortcuts if for example the user is writing an essay on the industrial revolution a replacement key can be set up to replace ir with industrial revolution saving the user time whenever they want to type it for users with the patience this facility can even be used to create a complete keyboard shorthand system along lines similar to those of dutton speedwords but with short forms instantly replaced by full forms some stand alone programs allow global text replacement across the operating system and apply to text typed into any other application the list of terms within the default microsoft autocorrect application in microsoft word can be replaced by words terms expressions etc other than the default set doing so in a wise comprehensive and strategic manner can immensely improve the keyboarding productivity and accuracy in high production work settings to get the most from the autocorrect routine one may best exploit the fact that the most common words typed are the best candidates for which to deploy shortcuts for example using t for the w for with etcetera can maximize the keystroke to production ratio any system such as developing a technique requires a learning curve to achieve mastery but experience in developing a database of expressions has proven that to ensure most effective use of autocorrect shortcuts must be easy to recall for example the threshold of characters in the chosen word is no less than three 3 except when the 2 letter word is within a longer expression e g aamof for as a matter of fact one technique in developing a system of large database of terms is using prefixes and suffixes in the formation of a shortcut for example using the suffix z mnemonic expandz for the asapz to expand to as as soon as possible whether one requires either a robust or moderate exploitation of the autocorrect this feature may be best used by first deleting the default terms that are supplied by the manufacturer those default terms typically include those words most commonly mis typed including those terms e g teh for the invites careless and or thoughtless actions whereas excluding them invites a learning process or greater productivity in a robust exploitation of autocorrect including chemical notation the deployment could transcends the perceived disadvantage of autocorrect the simple use of a shortcut suffix denoting chemical glossaries would be deployed for example using campx for camp and camp ¥ for cyclic adenosine monophosphate and camp ¥ x for c 10 h 12 n 5 o 6 p with corresponding sub script or super script as needed the shortcut campx with camp furthermore if when the full expression was needed the developer could invoke ¥ to be the suffix for chemical notation e g substitute
autofill is a function in some computer applications or programs typically those containing forms which fills in a field automatically most of the time such as in internet explorer and google toolbar the entries depend on the form field s name so as to not enter street names in a last name field or vice versa for this use proposed names for such form fields but in the html 5 specification this rfc is no longer referenced thus leaving the selection of names up to each browser s implementation companies which specialise in autofill are google autofill safari autofill dashlane fillr autofill for mobile compare autotype compare autocomplete
autoimmune inflammatory syndrome induced by adjuvants also known as shoenfeld s syndrome or asia is an alleged autoimmune disorder first proposed by israeli immunologist yehuda shoenfeld in 2011 according to shoenfeld the syndrome includes four conditions post vaccination symptoms macrophagic myofasciitis gulf war syndrome and siliconosis shoenfeld alleges that the syndrome is caused by adjuvants such as silicone tetramethylpentadecane pristane and aluminum however causality is difficult to prove because asia only occurs in a small fraction of patients exposed to these adjuvants shoenfeld has also named sjögren s syndrome as potentially being another facet of asia in 2013 the authors of a textbook on autoimmune diseases concluded that there exists persuasive evidence for asia but noted that several academic and governmental agencies had dismissed the possibility of a link between silicone and autoimmune disease
autoimmune oophoritis is an autoimmune disease caused when the immune system attacks the ovaries
autoimmune autonomic ganglionopathy aag is an extremely rare form of dysautonomia in which the patients immune system produces ganglionic achr antibodies inhibiting ganglionic achr currents and impairing transmission in autonomic ganglia approximately 100 americans are diagnosed with aag each year symptoms onset can be acute subacute or gradual
an autoimmune disease is a condition arising from an abnormal immune response to a normal body part there are at least 80 types of autoimmune diseases nearly any body part can be involved commons symptoms include low grade fever and feeling tired often symptoms come and go the cause is generally unknown some autoimmune diseases run in families such as lupus and certain cases may be triggered by infections or other environmental factors some common autoimmune disease include celiac disease diabetes mellitus type 1 graves disease inflammatory bowel disease multiple sclerosis psoriasis rheumatoid arthritis and systemic lupus erythematosus the diagnosis can be difficult to determine treatment depends on the type and severity of the condition nonsteroidal anti inflammatory drugs nsaids and immunosuppressants are often used intravenous immunoglobulin may also occasionally be used while treatment usually improves symptoms they do not typically cure the disease about 24 million 7 of people in the united states are affected by an autoimmune disease women are more commonly affected than men often they start during adulthood the first autoimmune diseases were described in the early 1900 s
autoimmune encephalitis or autoimmune encephalopathy is a diverse group of neuro psychiatric disorders recognized recently presenting acutely or subacutely with alteration of consciousness cognitive decline seizure abnormal movements associated with systemic autoimmune disorders cns autoimmune disorders and paraneoplastic syndromes pathogenesis is likely to be mediated by antibodies abs to cns proteins the abs are directed against membrane receptors and ion channel associated proteins that are expressed on the surface of neurons in the cns such as n methyl d aspartate receptors and leucine rich glioma inactivated protein and contactin associated protein like that are associated with voltage gated potassium channels the diseases are not invariably cancer related and are therefore different from the classical paraneoplastic neurological diseases that are associated with but not caused by abs to intracellular proteins diagnosis of autoimmune encephalopathy is based on the clinical course serologic evidence of autoimmunity severe but nonspecific slowing on electroencephalography and evidence of intrathecal inflammation in the cerebrospinal fluid and neuroimaging by mri treatment include first line steroids intravenous immunoglobulins ivig and plasma exchange and second line rituximab and cyclophosphamide followed in many cases by steroid sparing agents in the long term
autoimmune enteropathy aie is a rare disorder of the immune system condition that affects infants young children and rarely adults causing severe diarrhea vomiting and other morbidities of the digestive tract aie causes malabsorption of food vitamins and minerals often necessitating replacement fluids and total parenteral nutrition some disorders such as ipex syndrome include autoimmune enteropathy as well as autoimmune pathies of the skin thyroid other glands or kidneys
autoimmune estrogen dermatitis presents as a cyclic skin disorder that may appear eczematous papular bullous or urticarial with pruritus typically present skin eruptions that may be chronic but which are exacerbated premenstrually or occur immediately following menses
autoimmune gastrointestinal dysmotility agid is an autoimmune disease autonomic neuropathy affecting the gastrointestinal organs and digestive system of the body dysmotility is when the strength or coordination of the esophagus stomach or intestines muscles do not work as they should
autoimmune hemolytic anemia or autoimmune haemolytic anaemia aiha occurs when antibodies directed against the person s own red blood cells rbcs cause them to burst lyse leading to insufficient plasma concentration the lifetime of the rbcs is reduced from the normal 100 – 120 days to just a few days in serious cases the intracellular components of the rbcs are released into the circulating blood and into tissues leading to some of the characteristic symptoms of this condition the antibodies are usually directed against high incidence antigens therefore they also commonly act on allogenic rbcs rbcs originating from outside the person themselves e g in the case of a blood transfusion aiha is a relatively rare condition affecting one to three people per 100 000 per year the terminology used in this disease is somewhat ambiguous although mesh uses the term autoimmune hemolytic anemia some sources prefer the term immunohemolytic anemia so drug reactions can be included in this category the national cancer institute considers immunohemolytic anemia autoimmune hemolytic anemia and immune complex hemolytic anemia to all be synonyms
autoimmune hepatitis formerly called lupoid hepatitis is a chronic autoimmune disease of the liver that occurs when the body s immune system attacks liver cells causing the liver to be inflamed common initial symptoms include fatigue or muscle aches or signs of acute liver inflammation including fever jaundice and right upper quadrant abdominal pain individuals with autoimmune hepatitis often have no initial symptoms and the disease is detected by abnormal liver function tests anomalous presentation of human leukocyte antigen hla class ii on the surface of liver cells possibly due to genetic predisposition or acute liver infection causes a cell mediated immune response against the body s own liver resulting in autoimmune hepatitis this abnormal immune response results in inflammation of the liver which can lead to further symptoms and complications such as fatigue and cirrhosis the disease may occur in any ethnic group and at any age but is most often diagnosed in patients between age 40 and 50
autoimmune hypophysitis or lymphocytic hypophysitis is defined as inflammation of the pituitary gland due to autoimmunity
autoimmune inner ear disease aied was first defined by dr brian mccabe in a landmark paper describing an autoimmune loss of hearing the disease results in progressive sensorineural hearing loss snhl that acts bilaterally and asymmetrically and sometimes affects an individual s vestibular system aied is used to describe any disorder in which the inner ear is damaged as a result of an autoimmune response some examples of autoimmune disorders that have presented with aied are cogan s syndrome relapsing polychondritis systemic lupus erythematosus wegener s granulomatosis olyarteritis nodosa sjogren s syndrome and lyme disease research has come to the consensus that aied is the result of antibodies or other immune cells that cause damage to structures of the inner ear such as the cochlea and vestibular system of note aied is the only known snhl that responds to medical treatment but withholding treatment for longer than three months may result in permanent hearing loss and the need for cochlear implant installation although aied has been studied extensively over the past 25 years no clear mechanism of pathogenesis has emerged a recent paper performed a literature review of all relevant articles dating back to 1980 and proposed a mechanism of pathogenesis which includes an inflammatory response and immune cell attack on inner ear structures this response leads to an over activation of other immune cells such as t helper cells resulting in vascular changes and cochlear harm aied appears to be a consequence of damaged sensorineural hearing due to electrochemical disturbances microthrombosis and immune cell deposition additionally self reactive antibodies and t cells contribute to the aforementioned damage research has suggested a valuable next step in uncovering aied pathogenesis is inquiry into the role of interleukin 1 β il 1 β
autoimmune lymphoproliferative syndrome alps also known as canale smith syndrome is a form of lymphoproliferative disorder lpds it affects lymphocyte apoptosis it is a rasopathy it is a rare genetic disorder of abnormal lymphocyte survival caused by defective fas mediated apoptosis normally after infectious insult the immune system down regulates by increasing fas expression on activated b and t lymphocytes and fas ligand on activated t lymphocytes fas and fas ligand interact to trigger the caspase cascade leading to cell apoptosis patients with alps have a defect in this apoptotic pathway leading to chronic non malignant lymphoproliferation autoimmune disease and secondary cancers
autoimmune neutropenia is a form of neutropenia which is most common in infants and young children where the body identifies the neutrophils as enemies and makes antibody to destroy them primary autoimmune neutropenia ain is an autoimmune disease first reported in 1975 that primarily occurs in infancy in autoimmune neutropenia the immune system produces autoantibodies directed against the neutrophilic protein antigens in white blood cells known as granulocytic neutrophils granulocytes segmented neutrophils segs polysegmented neutrophils polys these antibodies destroy granulocytic neutrophils consequently patients with autoimmune neutropenia have low levels of granulocytic neutrophilic white blood cells causing a condition of neutropenia neutropenia causes an increased risk of infection from organisms that the body could normally fight easily who is affected primary autoimmune neutropenia has been reported as early as the second month of life although most cases are diagnosed in children between 5 and 15 months of age girls have a slightly higher risk of developing ain than boys in neutropenia discovered at birth or shortly after birth a diagnosis of allo immune neutropenia from maternal white blood cell antibodies passively transferred to the infant is more likely neutropenia in infants neutropenia is defined by absolute neutrophil counts less than 1000 ul after the first year of life neutropenia is defined by absolute counts less than 1500 ul neutropenia may be primary in which is the only blood abnormality seen in secondary neutropenia other primary conditions occur including other autoimmune diseases infections and malignancies neutropenia is considered chronic when it persists for more than 6 months symptoms and disease course neutropenia which may be discovered on routine blood tests typically causes benign infections even when the condition is severe ear infections otitis media are the most common infection seen in autoimmune neutropenia and typically infection responds to antibiotic treatment alone infections associated with primary ain are usually mild and limited including skin infections such as impetigo gastroenteritis upper respiratory tract infections and ear infections rarely cellulitis and abscesses may occur studies of children studied for up to six years showed that most cases of autoimmune neutropenia resolved spontaneously after a median of 17 months in 80 percent of patients neutropenia persisted for 7 to 24 months diagnosis patients with autoimmune neutropenia are diagnosed on the basis of blood tests showing neutropenia and the presence of granulocyte specific antibodies in some cases tests for granulocyte specific antibodies need to be repeated several times before a positive result is seen bone marrow aspiration if performed is typically normal or it can show increased cell production with a variably diminished number of segmented granulocytes s association with prior parvovirus b 19 has been made but this hasn ’ t been confirmed similar to the platelet deficiency idiopathic thrombocytopenic purpura vaccines are suspected of triggering this disorder treatment treatment consists of corticosteroids to reduce autoantibody production antibiotics to prevent infection and granulocyte colony stimulating factor g csf to temporarily increase neutrophil counts in cases of severe infection or the need for surgery intravenous immunoglobulin therapy may be used
in medicine autoimmune polyendocrine syndromes apss also called autoimmune polyglandular syndromes apss polyglandular autoimmune syndromes pgass or polyendocrine autoimmune syndromes are a heterogeneous group of rare diseases characterized by autoimmune activity against more than one endocrine organ although non endocrine organs can be affected there are three types of aps or in terms that mean the same thing three apss and there are a number of other diseases which have endocrine autoimmunity as one of their features
autoimmune polyendocrine syndrome type 1 aps 1 also known as autoimmune polyendocrinopathy candidiasis – ectodermal dystrophy dysplasia apeced autoimmune polyglandular syndrome type 1 whitaker syndrome or candidiasis hypoparathyroidism – addison s disease syndrome is a subtype of autoimmune polyendocrine syndrome autoimmune polyglandular syndrome in which multiple endocrine glands dysfunction as a result of autoimmunity it is a genetic disorder inherited in autosomal recessive fashion due to a defect in the aire gene autoimmune regulator which is located on chromosome 21 and normally confers immune tolerance
autoimmune polyendocrine syndrome type 2 a form of autoimmune polyendocrine syndrome also known as schmidt s syndrome or aps ii is the most common form of the polyglandular failure syndromes it is heterogeneous and has not been linked to one gene rather patients are at a higher risk when they carry a particular human leukocyte antigen genotype hla dq 2 hla dq 8 and hla dr 4 aps ii affects women to a greater degree than men 75 of cases occur in women features of this syndrome are addison s disease primary hypothyroidism graves disease pernicious anaemia primary hypogonadism less common diabetes mellitus type 1 vitiligo less common coeliac disease myasthenia gravis
autoimmune progesterone dermatitis may appear as urticarial papules deep gyrate lesions papulovesicular lesions an eczematous eruption or as targetoid lesions autoimmune progesterone dermatitis initially manifests with eye symptoms e g burning and progresses into rashes its relapsing remitting pattern in women correspond to the progesterone levels during the menstrual cycle which spike twice a month it is an extremely rare disease only perhaps 50 cases have ever been reported
autoimmune retinopathy is a rare disease in which the patient s immune system attacks proteins in the retina leading to loss of eyesight the disease is poorly understood but may be the result of cancer or cancer chemotherapy
autoimmune thyroiditis or chronic autoimmune thyroiditis is a disease in which the body interprets the thyroid glands and its hormone products t 3 t 4 and tsh as threats therefore producing special antibodies that target the thyroid ’ s cells thereby destroying it it presents with hypothyroidism or hyperthyroidism and the presence or absence of goiters
autoimmunity is the system of immune responses of an organism against its own healthy cells and tissues any disease that results from such an aberrant immune response is termed an autoimmune disease prominent examples include celiac disease diabetes mellitus type 1 sarcoidosis systemic lupus erythematosus sle sjögren s syndrome eosinophilic granulomatosis with polyangiitis hashimoto s thyroiditis graves disease idiopathic thrombocytopenic purpura addison s disease rheumatoid arthritis ra ankylosing spondylitis polymyositis pm and dermatomyositis dm autoimmune diseases are very often treated with steroids the misconception that an individual s immune system is totally incapable of recognizing self antigens is not new paul ehrlich at the beginning of the twentieth century proposed the concept of horror autotoxicus wherein a normal body does not mount an immune response against its own tissues thus any autoimmune response was perceived to be abnormal and postulated to be connected with human disease now it is accepted that autoimmune responses are an integral part of vertebrate immune systems sometimes termed natural autoimmunity normally prevented from causing disease by the phenomenon of immunological tolerance to self antigens autoimmunity should not be confused with alloimmunity
the autokinetic effect also referred to as autokinesis is a phenomenon of visual perception in which a stationary small point of light in an otherwise dark or featureless environment appears to move it was first recorded by a russian officer keeping watch who observed illusory movement of a star near the horizon it presumably occurs because motion perception is always relative to some reference point in darkness or in a featureless environment there is no reference point so the movement of the single point is undefined the direction of the movements does not appear to be correlated with the involuntary eye movements but may be determined by errors between eye position and that specified by efference copy of the movement signals sent to the extraocular muscles several researchers including richard gregory have shown that autokinesis occurs when no eye movements are recorded gregory has suggested that with lack of peripheral information correcting movements that prevent eye movements due to muscle fatigue are wrongly interpreted as movement of the light the amplitude of the movements is also undefined individual observers set their own frames of reference to judge amplitude and possibly direction because the phenomenon is labile it has been used to show the effects of social influence or suggestion on judgements for example if an observer who would otherwise say the light is moving one foot overhears another observer say the light is moving one yard then the first observer will report that the light moved one yard discovery of the influence of suggestion on the autokinetic effect is often attributed to sherif 1935 but it was recorded by adams 1912 if not others alexander von humboldt observed the phenomenon in 1799 while looking at stars with the naked eye but thought it was a real movement of the stars thus he named them sternschwanken i e swinging stars it was not until 1857 that g schweitzer schweitzer 1857 an early german psychologist discovered that it was a subjective phenomenon the us navy started studying this in 1945 in order to explain vertigo experiences related by pilots today this kinetic illusion is categorized as a vestibular induced illusion see vestibular system many sightings of ufos have also been attributed to the autokinetic effect s action on looking at stars or planets
automated theorem proving also known as atp or automated deduction is a subfield of automated reasoning and mathematical logic dealing with proving mathematical theorems by computer programs automated reasoning over mathematical proof was a major impetus for the development of computer science
automatic indexing is the ability for a computer to scan large volumes of documents against a controlled vocabulary taxonomy thesaurus or ontology and use those controlled terms to quickly and effectively index large document depositories as the number of documents exponentially increases with the proliferation of the internet automatic indexing will become essential to maintaining the ability to find relevant information in a sea of irrelevant information
automatic target recognition atr is the ability for an algorithm or device to recognize targets or objects based on data obtained from sensors target recognition was initially done by using an audible representation of the received signal where a trained operator who would decipher that sound to classify the target illuminated by the radar while these trained operators had success automated methods have been developed and continue to be developed that allow for more accuracy and speed in classification atr can be used to identify man made objects such as ground and air vehicles as well as for biological targets such as animals humans and vegetative clutter this can be useful for everything from recognizing an object on a battlefield to filtering out interference caused by large flocks of birds on doppler weather radar possible military applications include a simple identification system such as an iff transponder and is used in other applications such as unmanned aerial vehicles and cruise missiles there has been more and more interest shown in using atr for domestic applications as well research has been done into using atr for border security safety systems to identify objects or people on a subway track automated vehicles and many others
automatic writing or psychography is an alleged psychic ability allowing a person to produce written words without consciously writing the words are claimed to arise from a subconscious spiritual or supernatural source
automaticity ˌɔːtəməˈtɪsᵻti is the ability to do things without occupying the mind with the low level details required allowing it to become an automatic response pattern or habit it is usually the result of learning repetition and practice examples of automaticity are common activities such as walking speaking bicycle riding assembly line work and driving a car the last of these sometimes being termed highway hypnosis after an activity is sufficiently practiced it is possible to focus the mind on other activities or thoughts while undertaking an automatized activity for example holding a conversation or planning a speech while driving a car
automation bias – sometimes referred to by other terms such as automation induced complacency or over reliance on automation – is the propensity for humans to favor suggestions from automated decision making systems and to ignore contradictory information made without automation even if it is correct this bias takes the form of errors of exclusion and inclusion an automation bias of exclusion takes place when humans rely on an automated system that does not inform them of a problem while an error of inclusion arises when humans make choices based on incorrect suggestions relayed by automated systems automation bias has been examined across many research fields some factors leading to an over reliance on automation include inexperience in a task though inexperienced users tend to be most benefited by automated decision support systems lack of confidence in one ’ s own abilities a reflexive trust of the automated system a lack of readily available alternative information or as a way of saving time and effort on complex tasks or high workloads automation bias can be mitigated by the design of automated systems such as reducing the prominence of the display decreasing detail or complexity of information displayed or couching automated assistance as supportive information rather than as directives or commands training on an automated system which includes introducing deliberate errors has been shown to be significantly more effective at reducing automation bias than just informing users that errors can occur however excessive checking and questioning automated assistance can increase time pressures and complexity of tasks thus reducing the benefits of automated assistance so design of an automated decision support system can balance positive and negative effects rather than attempt to eliminate negative effects
in medicine automatism refers to a set of brief unconscious behaviors these typically last for several seconds to minutes or sometimes longer a time during which the subject is unaware of his her actions this type of automatic behaviour often occurs in certain types of epilepsy such as complex partial seizures in those with temporal lobe epilepsy or as a side effect of certain medications such as zolpidem
in mathematics an automorphic function is a function on a space that is invariant under the action of some group in other words a function on the quotient space often the space is a complex manifold and the group is a discrete group
autonoetic consciousness is the human ability to mentally place ourselves in the past in the future or in counterfactual situations and to thus be able to examine our own thoughts our sense of self affects our behavior in the present past and future it relates to how we reflect on our own past behavior how we feel about it and this in turn determines if we do it again p it is episodic memory that deals with self awareness memories of the self p and inward thoughts that may be projected onto future actions of an individual p it was “ proposed by endel tulving for self awareness allowing the rememberer to reflect on the contents of episodic memory ” p moreover autonoetic consciousness involves behaviors such as mental time travel schacter et al 2007 suddendorf and corballis 2007 self projection buckner and carroll 2007 and episodic future thinking atance and o neill 2001 all of which have often been proposed as exclusively human capacities
autonomic dysreflexia ad also known as autonomic hyperreflexia is a potentially life threatening condition which can be considered a medical emergency requiring immediate attention ad occurs most often in individuals with spinal cord injuries with spinal lesions above the t 6 spinal cord level although it has been known to occur in patients with a lesion as low as t 10 acute ad is a reaction of the autonomic involuntary nervous system to overstimulation it is characterized by paroxysmal hypertension the sudden onset of severe high blood pressure associated with throbbing headaches profuse sweating nasal stuffiness flushing of the skin above the level of the lesion slow heart rate anxiety and sometimes by cognitive impairment the sympathetic discharge that occurs is usually in association with spinal cord injury sci or diseases such as multiple sclerosis ad is believed to be triggered by afferent stimuli nerve signals that send messages back to the spinal cord and brain which originate below the level of the spinal cord lesion it is believed that these afferent stimuli trigger and maintain an increase in blood pressure via a sympathetically mediated vasoconstriction in muscle skin and splanchnic gut vascular beds
autophony or tympanophony is the unusually loud hearing of a person s own voice possible causes the occlusion effect caused by an object such as an unvented hearing aid or a plug of ear wax blocking the ear canal and reflecting sound vibration back towards the eardrum serous otitis media open or patulous eustachian tube allowing vocal and or breathing sounds to be conducted into the middle ear superior canal dehiscence which can lead to an abnormally amplified bone conduction of sound into the inner ear persons with superior canal dehiscence syndrome scds typically hear not only their own voice but also heartbeat footsteps chewing intestinal sounds and possibly even the sound of their eye movements when reading
autosave is a function in many computer applications or programs which saves an opened document automatically helping to reduce the risk or impact of data loss in case of a crash or freeze autosaving is typically done either in predetermined intervals or before a complex editing task is begun it has traditionally been seen as a feature to protect documents in an application or system failure crash and autosave backups are often purged whenever the user finishes his or her work an alternative paradigm is to have all changes saved continuously as with pen and paper and all versions of a document available for review this would remove the need for saving documents entirely there are challenges to implementation at the file application and operating system levels for example in microsoft excel 2003 this option is called autorecover and by default saves the document every ten minutes in the temporary file directory restarting excel after crashing prompts the user to save the last recovered version however this does not protect users who mistakenly click no when asked to save their changes if excel closes normally mac os 10 7 lion added an autosave feature that is available to some applications and works in conjunction with time machine like functionality to periodically save all versions of a document this eliminates the need for any manual saving as well as providing versioning support through the same system a version is saved every five minutes during any extended periods of idle time or when the user uses save a version which replaces the former save menu item and takes its command s shortcut saves are made on snapshots of the document date and occur in a separate thread so the user is never paused during this process applications need to be updated to take advantage of this functionality and a number of apple s built in programs were updated with the release autosave cannot be disabled in lion autosave is common in video games many video games have an autosave feature that saves progress during a session for example in an adventure game it may autosave after completing a level or mission or in fighting games it might save after winning a match some games use autosave as the only method of saving data and the player must complete a set amount of the game before saving takes place still another use of autosaving is as an anti cheating device for example in all megaman battle network games except the first the chip trader machines autosave upon giving out a new battle chip so the player can t cheat by soft resetting after each try of the chip trader until the desired chip is received one of the first implementation of this feature appears in the text editor elvis
autosensitization dermatitis or cutaneous autosensitization presents with the development of widespread dermatitis or dermatitis distant from a local inflammatory focus a process referred to as autoeczematization
autosomal dominant cerebellar ataxia adca is a form of spinocerebellar ataxia inherited in an autosomal dominant manner adca is a genetically inherited condition that causes deterioration of the nervous system leading to disorder and a decrease or loss of function to regions of the body degeneration occurs at the cellular level and in certain subtypes results in cellular death cellular death or dysfunction causes a break or faulty signal in the line of communication from the central nervous system to target muscles in the body when there is impaired communication or a lack of communication entirely the muscles in the body do not function correctly muscle control complications can be observed in multiple balance speech and motor or movement impairment symptoms adca is divided into three types and further subdivided into subtypes known as scas spinocerebellar ataxias
autosomal dominant hypophosphatemic rickets adhr is a rare hereditary disease in which excessive loss of phosphate in the urine leads to poorly formed bones rickets bone pain and tooth abscesses adhr is caused by a mutation in the fibroblast growth factor 23 fgf 23 adhr affects men and women equally symptoms may become apparent at any point from childhood through early adulthood blood tests reveal low levels of phosphate hypophosphatemia and inappropriately normal levels of vitamin d occasionally hypophosphatemia may improve over time as urine losses of phosphate partially correct adhr may be lumped in with x linked hypophosphatemia under general terms such as hypophosphatemic rickets hypophospatemic rickets are associated with at least nine other genetic mutations clinical management of hypophospatemic rickets may differ depending on the specific mutations associated with an individual case but treatments are aimed at raising phosphate levels to promote normal bone formation
autosomal dominant nocturnal frontal lobe epilepsy adnfle is an epileptic disorder that causes frequent violent seizures during sleep these seizures often involve complex motor movements such as hand clenching arm raising lowering and knee bending vocalizations such as shouting moaning or crying are also common adnfle is often misdiagnosed as nightmares attacks often occur in clusters and typically first manifest in childhood there are four known loci for adnfle three with known causative genes these genes chrna 4 chrnb 2 and chrna 2 encode various nicotinic acetylcholine receptor α and β subunits
autosomal dominant polycystic kidney disease adpkd autosomal dominant pkd or adult onset pkd is the most prevalent potentially lethal monogenic human disorder it is associated with large interfamilial and intrafamilial variability which can be explained to a large extent by its genetic heterogeneity and modifier genes it is also the most common of the inherited cystic kidney diseases — a group of disorders with related but distinct pathogenesis characterized by the development of renal cysts and various extrarenal manifestations which in case of adpkd include cysts in other organs such as the liver seminal vesicles pancreas and arachnoid membrane as well as other abnormalities such as intracranial aneurysms and dolichoectasias aortic root dilatation and aneurysms mitral valve prolapse and abdominal wall hernias over 50 of patients with adpkd eventually develop end stage kidney disease and require dialysis or kidney transplantation adpkd is estimated to affect at least 1 in every 1000 individuals worldwide making this disease the most common inherited kidney disorder with a diagnosed prevalence of 1 2000 and incidence of 1 3000 1 8000 in a global scale
autosomal recessive cerebellar ataxia type 1 arca 1 is a condition characterized by progressive problems with movement signs and symptoms of the disorder first appear in early to mid adulthood people with this condition initially experience impaired speech dysarthria problems with coordination and balance ataxia or both they may also have difficulty with movements that involve judging distance or scale dysmetria other features of arca 1 include abnormal eye movements nystagmus and problems following the movements of objects with their eyes the movement problems are slowly progressive often resulting in the need for a cane walker or wheelchair
autosomal recessive multiple epiphyseal dysplasia armed also called epiphyseal dysplasia multiple 4 edm 4 multiple epiphyseal dysplasia with clubfoot or – with bilayered patellae is an autosomal recessive congenital disorder affecting cartilage and bone development the disorder has relatively mild signs and symptoms including joint pain scoliosis and malformations of the hands feet and knees some affected individuals are born with an inward and downward turning foot a clubfoot an abnormality of the kneecap called a double layered patella is also relatively common although some people with recessive multiple epiphyseal dysplasia have short stature as adults most are of normal height the incidence is unknown as many cases are not diagnosed due to mild symptoms
autosomal recessive polycystic kidney disease arpkd is the recessive form of polycystic kidney disease it is associated with a group of congenital fibrocystic syndromes mutations in the pkhd 1 chromosomal locus 6 p 12 2 cause arpkd
autotopagnosia from the greek a and gnosis meaning without knowledge topos meaning place and auto meaning oneself autotopagnosia virtually translates to the lack of knowledge about one s own space and is clinically described as such autotopagnosia is a form of agnosia characterized by an inability to localize and orient different parts of the body the psychoneurological disorder has also been referred to as body image agnosia or somatotopagnosia somatotopagnosia has been argued to be a better suited term to describe the condition while autotopagnosia emphasizes the deficiencies in localizing only one s own body parts and orientation somatotopagnosia also considers the inability to orient and recognize the body parts of others or representations of the body e g manikins diagrams typically the cause of autotopagnosia is a lesion found in the parietal lobe of the left hemisphere of the brain however it as also been noted that patients with generalized brain damage present with similar symptoms of autotopagnosia as a concept autotopagnosia has been criticized as nonspecific some claim that this is a manifestation of a greater symptomatic complex of anomia marked by an inability to name things in general — not just parts of the human body
autotype is a function in some computer applications or programs typically those containing forms which fills in a field once you have typed in the first few letters most of the time such as in a web browser the entries that appear in the list depend on the form s name so as to not propose street names in a last name field or vice versa autotype can also refer to automatically determining a peripheral s configuration or a program s variables autotype is defined as a true representation of the original see o e d the term autotype was coined in the late 19 th century and referred to a process for making photographic prints using a carbon process many autotype prints were produced and the process was popular well into the 20 th century particularly since autotype prints are very long lasting it is said that an autotype could last up to 500 years without fading autotype may also refer to halftone printing the term may also apply to the autotype company founded in london in 1868 as the autotype fine art company which was one of the pioneers in the carbon print and autotype reproduction process and which still exists as a supplier of coated films autotype is now part of the platform speciality products group of companies
autumn leaf color is a phenomenon that affects the normally green leaves of many deciduous trees and shrubs by which they take on during a few weeks in the autumn season various shades of red yellow purple black orange pink magenta blue and brown the phenomenon is commonly called autumn colours or autumn foliage in british english and fall colors fall foliage or simply foliage in american english in some areas of canada and the united states leaf peeping tourism is a major contribution to economic activity this tourist activity occurs between the beginning of color changes and the onset of leaf fall usually around september and october in the northern hemisphere and april to may in the southern hemisphere
auxiliary japanese armours are optional armour items worn by the samurai class of feudal japan in addition to the traditional six armour components
the availability factor of a power plant is the amount of time that it is able to produce electricity over a certain period divided by the amount of the time in the period occasions where only partial capacity is available may or may not be deducted where they are the metric is titled equivalent availability factor eaf the availability factor should not be confused with the capacity factor the capacity factor for a period will always be less than the equivalent availability factor for the same period the difference depends on the utilization of the power plant the availability of a power plant varies greatly depending on the type of fuel the design of the plant and how the plant is operated everything else being equal plants that are run less frequently have higher availability factors because they require less maintenance most thermal power stations such as coal geothermal and nuclear power plants have availability factors between 70 and 90 newer plants tend to have significantly higher availability factors but preventive maintenance is as important as improvements in design and technology gas turbines have relatively high availability factors ranging from 80 to 99 gas turbines are commonly used for peaking power plants co generation plants and the first stage of combined cycle plants the availability factor of wind and solar power plants depends on whether periods when the plant is operational but there is no wind or sunlight are counted as available unavailable or disregarded if they are only counted as available during favorable times photovoltaic plants have an availability factor approaching or equal to 100 modern wind turbines also have very high availability factors about 98 however solar and wind plants have relatively low capacity factors wind capacity factors range from 20 – 40 and solar capacity factors in arizona are about 19 this makes wind and solar availability factors much lower if times when sunlight or wind are not available are taken into account
available to promise atp is a business function that provides a response to customer order enquiries based on resource availability it generates available quantities of the requested product and delivery due dates therefore atp supports order promising and fulfillment aiming to manage demand and match it to production plans available to promise functions are it enabled and usually integrated in enterprise management software packages however atp execution may need to be adjusted for the way a certain company operates
in the wireless industry available revenue time art is the amount of user time available from which mobile carriers may generate revenue for example using a wireless mobile device for 60 minutes has enabled the carrier on whose telecommunications network the user s device is operating to generate revenue for 60 minutes revenue is typically generated by billing for services such as sms mobile video mobile tv or other multi media options typical in modern convergent devices
an avalanche boulder tongue is an accumulation of debris produced by snow avalanches well developed avalanche boulder tongue usually develop below avalanche gullies due to successive avalanches over a long time span the avalanche boulder tongues were first intensively investigated by anders rapp in the areas of abisko and kebnekaise in swedish lappland
avalanche breakdown is a phenomenon that can occur in both insulating and semiconducting materials it is a form of electric current multiplication that can allow very large currents within materials which are otherwise good insulators it is a type of electron avalanche the avalanche process occurs when carriers in the transition region are accelerated by the electric field to energies sufficient to create mobile or free electron hole pairs via collisions with bound electrons
avascular necrosis avn also called osteonecrosis bone infarction aseptic necrosis and ischemic bone necrosis is cellular death necrosis of bone components due to interruption of the blood supply without blood the bone tissue dies and the bone collapses if avascular necrosis involves the bones of a joint it often leads to destruction of the joint articular surfaces see osteochondritis dissecans
avellis syndrome is a neurological disorder characterized by a peculiar form of alternating paralysis there is paralysis of the soft palate and vocal cords on one side and loss of pain sensation and temperature sense on the other side including the extremities trunk and neck it usually results from occlusion of the vertebral artery in lesions of the nucleus ambiguous and pyramidal tract horner s syndrome may be associated in the original description the vagus and glossopharyngeal nerves were involved concomitant involvement of the neighbouring cranial nerves was observed later
in gemology aventurescence sometimes called aventurization is an optical reflectance effect seen in certain gems the effect amounts to a metallic glitter arising from minute preferentially oriented mineral platelets within the material these platelets are so numerous that they also influence the material s body colour in aventurine quartz chrome bearing fuchsite produces a green stone and various iron oxides produces a red stone the words aventurine and aventurescence derive from the italian a ventura meaning by chance this is an allusion to the chance discovery of aventurine glass or goldstone at some point in the 18 th century goldstone is still manufactured today as an artificial imitation of later discoveries aventurine quartz and aventurine feldspar sunstone
in computational complexity theory the average case complexity of an algorithm is the amount of some computational resource typically time used by the algorithm averaged over all possible inputs it is frequently contrasted with worst case complexity which considers the maximal complexity of the algorithm over all possible inputs there are three primary motivations for studying average case complexity first although some problems may be intractable in the worst case the inputs which elicit this behavior may rarely occur in practice so the average case complexity may be a more accurate measure of an algorithm s performance second average case complexity analysis provides tools and techniques to generate hard instances of problems which can be utilized in areas such as cryptography and derandomization third average case complexity allows discriminating the most efficient algorithm in practice among algorithms of equivalent based case complexity for instance quicksort average case analysis requires a notion of an average input to an algorithm which leads to the problem of devising a probability distribution over inputs alternatively a randomized algorithm can be used the analysis of such algorithms leads to the related notion of an expected complexity
avian malaria is a parasitic disease of birds
avian vacuolar myelinopathy avm is a fatal neurological disease that affects various waterbirds and raptors it is most common in the bald eagle and american coot and it is known in the killdeer bufflehead northern shoveler american wigeon canada goose great horned owl mallard and ring necked duck avian vacuolar myelinopathy is a newly discovered disease that was first identified in the field in 1994 when dead bald eagles were found near degray lake in arkansas in the united states since then it has spread to four more states and infested multiple aquatic systems including 10 reservoirs the cause of death is lesions on the brain and spinal cord but the exact causative agent is still being investigated by researchers an infectious cyanobacterium is suspected
avocado sunblotch viroid asbv is an important disease affecting avocado trees infections result in lower yields and poorer quality fruit asbv is the smallest known viroid that infects plants and is transmitted by pollen and infected seeds or budwood trees infected with the viroid often show no symptoms other than a reduction in yield by 30 or more however they are still carriers and can pass the disease onto other plants symptoms in more serious infections include depressed longitudinal streaks of yellow in the fruit the fruit may also become red or white in colour symptoms in the leaf are uncommon but include bleached veins and petioles rectangular cracking patterns also occur in the bark of older branches the amount titre of viroid particles present in avocado trees varies a great deal viroids levels can vary by 1000 times between branches on the same tree and by 10000 times between trees infected but symptomless trees have a higher concentration of viroid particles than those showing symptoms symptomless trees also represent a greater danger in terms of spread of the viroid pcr is used to detect infection
avoidant restrictive food intake disorder arfid also previously known as selective eating disorder sed is a type of eating disorder where the consumption of certain foods is limited based on the food s appearance smell taste texture or a past negative experience with the food
avoidant personality disorder avpd also known as anxious personality disorder is a cluster c personality disorder those affected display a pattern of social inhibition feelings of inadequacy and inferiority extreme sensitivity to negative evaluation and avoidance of social interaction despite a strong desire to be close to others individuals with the disorder tend to describe themselves as uneasy anxious lonely unwanted and isolated from others the behavior typically begins by early adulthood and occurs across a variety of situations the cause is unknown it is recognized by the diagnostic and statistical manual of mental disorders people with avoidant personality disorder often consider themselves to be socially inept or personally unappealing and avoid social interaction for fear of being ridiculed humiliated rejected or disliked as the name suggests the main coping mechanism of those with avoidant personality disorder is avoidance of feared stimuli avoidant personality disorder is usually first noticed in early adulthood with both childhood emotional neglect — in particular the rejection of a child by one or both parents — and peer group rejection being associated with an increased risk for its development
avolition as a symptom of various forms of psychopathology is the decrease in the motivation to initiate and perform self directed purposeful activities such activities that appear to be neglected usually include routine activities including hobbies going to work and or school and most notably engaging in social activities a person experiencing avolition may stay at home for long periods of time rather than seeking out work or peer relations
an avulsion fracture is a bone fracture which occurs when a fragment of bone tears away from the main mass of bone as a result of physical trauma this can occur at the ligament due to the application forces external to the body such as a fall or pull or at the tendon due to a muscular contraction that is stronger than the forces holding the bone together generally muscular avulsion is prevented due to the neurological limitations placed on muscle contractions highly trained athletes can overcome this neurological inhibition of strength and produce a much greater force output capable of breaking or avulsing a bone
in medicine an avulsion is an injury in which a body structure is forcibly detached from its normal point of insertion by either trauma or surgery from the latin avellere meaning to tear off the term most commonly refers to a surface trauma where all layers of the skin have been torn away exposing the underlying structures i e subcutaneous tissue muscle tendons or bone this is similar to an abrasion but more severe as body parts such as an eyelid or an ear can be partially or fully detached from the body
awareness is the ability to directly know and perceive to feel or to be of events more broadly it is the state or quality of being conscious of something
axenfeld syndrome also known as axenfeld rieger syndrome or hagedoom syndrome is a rare autosomal dominant disorder which affects the development of the teeth eyes and abdominal region
axial osteomalacia is a rare osteosclerotic disorder characterized by axial skeleton pain coarsening of the trabecular bone pattern on radiographs of the axial but not appendicular skeleton
axillary lymphadenopathy is lymphadenopathy of the axillary lymph nodes
axillary nerve palsy is a neurological condition in which the axillary also called circumflex nerve has been damaged by shoulder dislocation it can cause weak deltoid and sensory loss below the shoulder since this is a problem with just one nerve it is a type of peripheral neuropathy called mononeuropathy of all brachial plexus injuries axillary nerve palsy represents only 3 to 6 of them
axon guidance also called axon pathfinding is a subfield of neural development concerning the process by which neurons send out axons to reach the correct targets axons often follow very precise paths in the nervous system and how they manage to find their way so accurately is being researched
axonotmesis is a disruption of nerve cell axon with wallerian degeneration occurring below and slightly proximal to the site of injury if axons and their myelin sheath are damaged but schwann cells the endoneurium perineurium and epineurium remain intact it is called axonotmesis axonotmesis is usually the result of a more severe crush or contusion than neuropraxia in axonotmesis the proximal section is repaired by creating a sprout with its growth cone but in the distal section occurs axonal degeneration the rate of outgrowth of regenerating nerve fibers is about 1 mm to 2 mm per day so that the recovery of conduction to a target structure depends on not only regrowth into the appropriate endoneurial tube endoneurium but also on the distance involved
ayazi syndrome or chromosome 21 xq 21 deletion syndrome is a syndrome characterized by choroideremia congenital deafness and obesity
an azo coupling is an organic reaction between a diazonium compound and another aromatic compound that produces an azo compound in this electrophilic aromatic substitution reaction the aryldiazonium cation is the electrophile and the activated arene is a nucleophile in most cases including the examples below the diazonium compound is also aromatic
azoospermia is the medical condition of a man when sperm count is equal or less then 15 million ml in his semen it is associated with very low levels of fertility or even sterility but many forms are amenable to medical treatment in humans azoospermia affects about 1 of the male population and may be seen in up to 20 of male infertility situations
azotemia azot nitrogen emia blood condition is a medical condition characterized by abnormally high levels of nitrogen containing compounds such as urea creatinine various body waste compounds and other nitrogen rich compounds in the blood it is largely related to insufficient or dysfunctional filtering of blood by the kidneys it can lead to uremia if not controlled
azukiarai 小豆洗い azuki bean washing or azukitogi 小豆とぎ azuki bean grinding is a ghostly phenomenon in japanese folklore in which a mysterious noise that sounds like azuki beans being washed or ground is heard it usually occurs near a river or other body of water sometimes the creature or spirit responsible amuses itself by singing azuki togou ka hito totte kuou ka shoki shoki will i grind my azuki beans or will i get a person to eat shoki shoki and anyone who approaches will inevitably fall into the water while the perpetrator is seldom seen he is often described as a short statured man of grotesque appearance with a large balding head crooked teeth thin moustache large bulging yellow eyes wearing ragged clothes and bent over a pail washing azuki beans azukiarai is sometimes blamed on a raccoon dog or weasel
the azzopardi phenomenon or azzopardi effect is the presence of dna in necrotic venules it can occur in small cell carcinomas and in some high grade malignant neoplasms the effect is well known in diagnostic surgical pathology the phenomenon is named after the pathologist john g azzopardi azzopardi was able to correctly characterize the effect as due to dna it had been thought previously but incorrectly to be calcium necrosis results in the release of cellular dna which adheres in patches to the walls of blood vessels showing as intensely basophilic material on hematoxylin eosin stain the azzopardi phenomenon is distinguished from the similar basophilic hematoxylin body add refs
b cell chronic lymphocytic leukemia b cll also known as chronic lymphoid leukemia cll is the most common type of leukemia a type of cancer of the white blood cells in adults cll affects b cell lymphocytes which originate in the bone marrow develop in the lymph nodes and normally fight infection by producing antibodies in cll b cells grow in an uncontrolled manner and accumulate in the bone marrow and blood where they crowd out healthy blood cells cll is a stage of small lymphocytic lymphoma sll a type of b cell lymphoma which presents primarily in the lymph nodes cll and sll are considered the same underlying disease just with different appearances cll is a disease of adults most 75 people newly diagnosed with cll are over the age of 50 and the majority are men however in rare cases it can occur in teenagers and occasionally in children some of these may relate to an inherited predisposition most people are diagnosed without symptoms as the result of a routine blood test that returns a high white blood cell count but as it advances cll results in swollen lymph nodes spleen and liver and eventually anemia and infections early cll is not treated and late cll is treated with chemotherapy and monoclonal antibodies dna analysis has distinguished two major types of cll with different survival times cll that is positive for the marker zap 70 has an average survival of 8 years while cll negative for zap 70 has an average survival of more than 25 years many patients especially older ones with slowly progressing disease can be reassured and may not need any treatment in their lifetimes
a b cell leukemia is any of several types of lymphoid leukemia which affect b cells types include with icd o code 9823 3 b cell chronic lymphocytic leukemia small lymphocytic lymphoma 9826 3 acute lymphoblastic leukemia mature b cell type 9833 3 b cell prolymphocytic leukemia 9835 3 9836 3 precursor b lymphoblastic leukemia 9940 3 hairy cell leukemia
the b cell lymphomas are types of lymphoma affecting b cells lymphomas are blood cancers in the lymph nodes they develop more frequently in older adults and in immunocompromised individuals b cell lymphomas include both hodgkin s lymphomas and most non hodgkin lymphomas they are typically divided into low and high grade typically corresponding to indolent slow growing lymphomas and aggressive lymphomas respectively as a generalisation indolent lymphomas respond to treatment and are kept under control in remission with long term survival of many years but are not cured aggressive lymphomas usually require intensive treatments with some having a good prospect for a permanent cure prognosis and treatment depends on the specific type of lymphoma as well as the stage and grade treatment includes radiation and chemotherapy early stage indolent b cell lymphomas can often be treated with radiation alone with long term non recurrence early stage aggressive disease is treated with chemotherapy and often radiation with a 70 90 cure rate late stage indolent lymphomas are sometimes left untreated and monitored until they progress late stage aggressive disease is treated with chemotherapy with cure rates of over 70
b cell prolymphocytic leukemia is a more aggressive but still treatable form of leukemia the malignant b cells are larger than average the name is commonly abbreviated b pll it can involve deletions from chromosome 11 and chromosome 13 it has been suggested that some cases may represent a variant of mantle cell lymphoma it has a relatively poor prognosis
in the mathematical subfield of numerical analysis a b spline or basis spline is a spline function that has minimal support with respect to a given degree smoothness and domain partition any spline function of given degree can be expressed as a linear combination of b splines of that degree cardinal b splines have knots that are equidistant from each other b splines can be used for curve fitting and numerical differentiation of experimental data in the computer aided design and computer graphics spline functions are constructed as linear combinations of b splines with a set of control points
bcg disease is an adverse effect of the bacillus calmette guérin vaccine the vaccine contains living mycobacterium bovis bcg and in bcg disease the bacterium causes a disease in persons vaccinated between 2000 and 2006 several hundred children in finland had serious adverse events from the vaccine including osteitis and osteomyelitis disseminated usually fatal bcg infection arthritis and lymph node abscesses four deaths were registered in the official adverse event register and while in only two cases a clear causal link was considered to be in place two other cases were diagnosed with a disease which in scientific peer reviewed articles case descriptions have been mistakenly first made and afterward have been noticed to be disseminated bcg infections one death with a causal link considered established by the adverse event monitoring agency was vaccinated with pre august 2002 vaccine evans while the three other registered deaths were with the new post august 2002 vaccine bcg vaccine ssi
benta disease is a rare genetic disorder of the immune system benta stands for b cell expansion with nf κb and t cell anergy and is caused by germline heterozygous gain of function mutations in the gene card 11 see omim entry 607210 this disorder is characterized by polyclonal b cell lymphocytosis with onset in infancy splenomegaly lymphadenopathy mild immunodeficiency and increased risk of lymphoma investigators andrew l snow and michael j lenardo at the national institute of allergy and infectious disease at the u s national institutes of health first characterized benta disease in 2012 dr snow s current laboratory at the uniformed services university of the health sciences is now actively studying this disorder
be is pain of salvation s fifth studio album released by insideoutmusic in september 2004 it is a concept album focusing on the existence of god and humankind along with the band it features a nine part orchestra the orchestra of eternity which features prominently throughout the album this is the last album to feature kristoffer gildenlöw on bass the album is the first pain of salvation album to be divided into more than three chapters the band performed it live as a rock opera it was released as be original stage production
be original stage production is swedish progressive metal band pain of salvation s first live dvd and second live cd documenting one of the performances of their 2004 album be in its entirety in eskilstuna sweden on september 12 2003 in contrast to the studio album the orchestra of eternity a nine piece orchestra accompanying the band are given credit on the front cover of the album though they weren t shown on the initial promo release
the nassau street loop also called the nassau loop was a service pattern of the brooklyn – manhattan transit corporation bmt inaugurated in 1931 when the bmt nassau street line was completed providing a physical link that allowed a train to originate in brooklyn run through lower manhattan and return to brooklyn without having to terminate and reverse the direction of the train nassau loop services have not been able to operate since 1967 when the loop line s connection to the manhattan bridge was severed the centre street loop was a similar service proposal that was never completed together they are referred to as the bmt brooklyn loops
in computational complexity theory bpp which stands for bounded error probabilistic polynomial time is the class of decision problems solvable by a probabilistic turing machine in polynomial time with an error probability bounded away from 1 3 for all instances bpp is one of the largest practical classes of problems meaning most problems of interest in bpp have efficient probabilistic algorithms that can be run quickly on real modern machines bpp also contains p the class of problems solvable in polynomial time with a deterministic machine since a deterministic machine is a special case of a probabilistic machine informally a problem is in bpp if there is an algorithm for it that has the following properties it is allowed to flip coins and make random decisions it is guaranteed to run in polynomial time on any given run of the algorithm it has a probability of at most 1 3 of giving the wrong answer whether the answer is yes or no
in computational complexity theory bqp bounded error quantum polynomial time is the class of decision problems solvable by a quantum computer in polynomial time with an error probability of at most 1 3 for all instances it is the quantum analogue of the complexity class bpp in other words there is an algorithm for a quantum computer a quantum algorithm that solves the decision problem with high probability and is guaranteed to run in polynomial time on any given run of the algorithm it has a probability of at most 1 3 that it will give the wrong answer similarly to other bounded error probabilistic classes the choice of 1 3 in the definition is arbitrary we can run the algorithm a constant number of times and take a majority vote to achieve any desired probability of correctness less than 1 using the chernoff bound detailed analysis shows that the complexity class is unchanged by allowing error as high as 1 2 − n − c on the one hand or requiring error as small as 2 − nc on the other hand where c is any positive constant and n is the length of input
bzlf 1 also known as zta eb 1 associated with its product gene zebra is an immediate early viral gene of the epstein – barr virus ebv of the herpes virus family which induces cancers and infects primarily the b cells of 95 of the human population this gene along with others produces the expression of other ebv genes in other stages of disease progression and is involved in converting the virus from the latent to the lytic form
b type inclusions formerly known as guarnieri bodies ɡwɑːrˈnjɛri are cellular features found upon microscopic inspection of epithelial cells of individuals suspected of having poxvirus e g smallpox or vaccinia in cells stained with eosin they appear as pink blobs in the cytoplasm of affected epithelial cells the absence of guarnieri bodies cannot be used as to rule out smallpox however as more sensitive test need to be performed b type inclusions are the sites of viral replication and are found in all poxvirus infected cells unlike a type inclusions which are more strongly eosinophilic and only found in infections with certain poxviruses they are named after the italian physician giuseppe guarnieri
in high energy physics b − l pronounced bee minus ell is the difference between the baryon number b and the lepton number l
baastrup s sign or kissing spine is an orthopedic and radiographic disorder that often occurs in elderly humans it is characterized by enlargement of the posterior spinous projections of the lumbar spine with normal intervertebral disc height and neuroforamina the reason it is referred to as kissing spine is because the posterior spinous processes kiss and touch one another as the individual goes into lumbar extension for example when flat on their stomach the condition has been seen in humans canines particularly with boxer breeds and certain breeds of horses this disorder is named after christian ingerslev baastrup
bab er robb arabic باب الرب is a southern gate exit to the city of marrakech morocco near bab agnaou it leads to the roads that lead to the mountain towns of amizmiz and asni robb is a beverage produced from figs and raspberries
babesiosis is a malaria like parasitic disease caused by infection with babesia a genus of apicomplexa human babesiosis is an uncommon but emerging disease in the northeastern and midwestern united states and parts of europe and sporadic throughout the rest of the world it occurs in warm weather ticks transmit the human strain of babesiosis so it often presents with other tick borne illnesses such as lyme disease after trypanosomes babesia is thought to be the second most common blood parasite of mammals and they can have a major impact on health of domestic animals in areas without severe winters in cattle a major host the disease is known as texas cattle fever redwater or piroplasmosis
babinski – nageotte syndrome sometimes called babinski syndrome is an alternating brainstem syndrome it occurs when there is damage to the dorsolateral or posterior lateral medulla oblongata hence it is also called the alternating medulla oblongata syndrome the rare disorder is caused by damage to a part of the brain medullobulbar transitional area which causes a variety of neurological symptoms some of which affect only one side of the body symptoms include ipsilateral cerebellar ataxia sesnory deficits of the face and horner s syndrome contraleteral there is body hemiplegia and hemianesthesia it was first described in 1902 and later named after the neurologists who initially investigated it joseph babinski and jean nageotte
symmetrical drug related intertriginous and flexural exanthema sdrife more popularly known as baboon syndrome because of its resemblance to the distinctive red buttocks displayed by some male baboon species is a systemic contact dermatitis characterized by well demarcated patches of erythema distributed symmetrically on the buttocks the cause of the syndrome may be drug related i e induced by systemic administration of hydroxyzine penicillin iodinated radio contrast media and others
baby colic also known as infantile colic is defined as episodes of crying for more than three hours a day for more than three days a week for three weeks in an otherwise healthy child often crying occurs in the evening it typically does not result in long term problems the crying can cause frustration for the parents depression following delivery excess visits to the doctor and child abuse the cause of colic is unknown some believe it is due to gastrointestinal discomfort like intestinal cramping diagnosis requires ruling out other possible causes concerning findings include a fever poor activity or a swollen abdomen fewer than 5 of infants with excess crying have an underlying organic disease treatment is generally conservative with little to no role for either medications or alternative therapies extra support for the parents may be useful tentative evidence supports probiotics in those who are breastfeed and hydrolyzed formula in those who are bottlefeed colic affects 10 – 40 of children it is most common at six weeks of age and typically goes away by six months of age it rarely lasts up to one year of age it occurs at the same rate in boys and in girls the first detailed medical description of the problem occurred in 1954
bacillary angiomatosis ba is a form of angiomatosis associated with bacteria of the bartonella genus
bacillary dysentery is a type of dysentery and is a severe form of shigellosis bacillary dysentery is associated with species of bacteria from the enterobacteriaceae family the term is usually restricted to shigella infections shigellosis is caused by one of several types of shigella bacteria three species are associated with bacillary dysentery shigella sonnei shigella flexneri and shigella dysenteriae a study in china indicated that shigella flexneri 2 a was the most common serotype salmonellosis caused by salmonella enterica serovar typhimurium has also been described as a cause of bacillary dysentery though this definition is less common it is sometimes listed as an explicit differential diagnosis of bacillary dysentery as opposed to a cause bacillary dysentery should not be confused with diarrhea caused by a bacterial infection one characteristic of bacillary dysentery is blood in stool which is the result of invasion of the mucosa by the pathogen
bacillary peliosis is a form of peliosis hepatis that has been associated with bacteria in the genus bartonella
back off pattern is a behavioral software design pattern that is used when the software developer wants to reduce the usage of system resources
back pain is pain felt in the back episodes of back pain may be acute sub acute or chronic depending on the duration the pain may be characterized as a dull ache shooting or piercing pain or a burning sensation the pain may radiate into the arms and hands as well as the legs or feet and may include paresthesia tingling with no apparent cause weakness or numbness in the legs and arms the anatomic classification of back pain follows the segments of the spine neck pain cervical middle back pain thoracic lower back pain lumbar or coccydynia tailbone or sacral pain with the lumbar vertebrae area most common for pain the pain may originate from the muscles nerves bones joints or other structures in the vertebral column spine internal structures such as the gallbladder and pancreas may also cause referred pain in the back back pain is common with about nine out of ten adults experiencing it at some point in their life and five out of ten working adults having it every year however it is rare for it to be permanently disabling and in most cases of herniated disks and stenosis rest injections or surgery have similar general pain resolution outcomes on average after one year in the united states acute low back pain is the fifth most common reason for physician visits and causes 40 of missed days off work additionally it is the single leading cause of disability worldwide
background independence is a condition in theoretical physics that requires the defining equations of a theory to be independent of the actual shape of the spacetime and the value of various fields within the spacetime in particular this means that it must be possible not to refer to a specific coordinate system — the theory must be coordinate free in addition the different spacetime configurations or backgrounds should be obtained as different solutions of the underlying equations
a backlash is an adverse reaction to something which has gained popularity prominence or influence although it can sometimes represent a categorical rejection of the idea aesthetic product or fad in question it is usually a reflection of a collective resentment of that thing s ubiquity in culture and media rather than a denial of its existence the term is commonly applied to gender and racial discrimination and religious discrimination against minority groups as well such as in response to certain events or circumstances
backpack palsy bpp — or rucksack palsy or rucksack paralysis — is a type of brachial plexus injury associated with carrying a heavy backpack or similar load with excessive compression of the shoulder areas by straps it is a known hazard for ruckmarching soldiers and for certain outdoor recreationalists hikers trekkers mountaineers etc and certain labors e g those carrying sandbags a particular risk factor is bearing heavy backpack loads without any waist support i e all the weight borne by the shoulders
a backwater valve is a backflow prevention device used to prevent outbound water through a dwelling s drain pipes from re entering back flowing — into a home the valve contains a flap that allows water to exit the home but closes to prevent the back flow into the home backwater valves commonly activate when a city s sewer lines are unable to handle a large amount of falling precipitation this puts homes that are tied into the storm lines at risk of having water back flow into them there is a big difference between backwater valves and backflow preventers a backwater valve prevents raw sewage from backing up into your home through your toilets showers etc a backflow preventer deals with protecting your potable water source from being contaminated by a reverse flow of foul water ex isolating your toilet s flush cistern and water supply from the toilet bowl water itself
bacteremia also bacteraemia is the presence of bacteria in the blood blood is normally a sterile environment so the detection of bacteria in the blood most commonly accomplished by blood cultures is always abnormal bacteria can enter the bloodstream as a severe complication of infections like pneumonia or meningitis during surgery especially when involving mucous membranes such as the gastrointestinal tract or due to catheters and other foreign bodies entering the arteries or veins including during intravenous drug abuse bacteremia can have several consequences the immune response to the bacteria can cause sepsis and septic shock which has a relatively high mortality rate bacteria can also use the blood to spread to other parts of the body which is called hematogenous spread causing infections away from the original site of infection examples include endocarditis or osteomyelitis treatment is with antibiotics and prevention with antibiotic prophylaxis can be given in situations where problems are to be expected
bacterial blight is a disease of barley caused by the bacterial pathogen xanthomonas campestris pv translucens syn x translucens it has been known as a disease since the late 19 th century it has a worldwide distribution
bacterial blight of cotton is a disease affecting the cotton plant resulting from infection by xanthomonas citri pathovar malvacearum xcm bacteria it is the most important bacterial disease on cotton which infects all aerial parts of the host loss due to this disease was estimated for about 10 to 30 on different cultivars
bacterial blight of soybean is a widespread disease caused by pseudomonas syringae pv glycinea
bacterial cold water disease bcwd is a bacterial disease of salmonid fish it is caused by flavobacterium psychrophilum previously classified in the genus cytophaga a gram negative rod shaped bacterium of the family flavobacteriaceae the disease typically occurs at temperatures below 13⁰ c and it can be seen in any area with water temperatures consistently below 15⁰ c salmon are the most commonly affected species this disease is not zoonotic asymptomatic carrier fish and contaminated water provide reservoirs for disease transmission is mainly horizontal but vertical transmission can also occur bcwd may be referred to by a number of other names including cold water disease peduncle disease fit rot tail rot and rainbow trout fry mortality syndrome
bacterial genetics is the subfield of genetics devoted to the study of bacteria bacterial genetics are subtly different from eukaryotic genetics however bacteria still serve as a good model for animal genetic studies one of the major distinctions between bacterial and eukaryotic genetics stems from the bacteria s lack of membrane bound organelles this is true of all prokaryotes while it is a fact that there are prokaryotic organelles they are never bound by a lipid membrane but by a shell of proteins necessitating protein synthesis occur in the cytoplasm like other organisms bacteria also breed true and maintain their characteristics from generation to generation yet at same time exhibit variations in particular properties in a small proportion of their progeny though heritability and variations in bacteria had been noticed from the early days of bacteriology it was not realised then that bacteria too obey the laws of genetics even the existence of a bacterial nucleus was a subject of controversy the differences in morphology and other properties were attributed by nageli in 1877 to bacterial pleomorphism which postulated the existence of a single a few species of bacteria which possessed a protein capacity for a variation with the development and application of precise methods of pure culture it became apparent that different types of bacteria retained constant form and function through successive generations this led to the concept of monomorphism
bacterial kidney disease bkd also known as white boil disease is a systemic infection caused by the bacterium renibacterium salmoninarum the disease affects populations of wild salmonid bkd was originally discovered in the scottish rivers of dee and spey in 1933
bacterial leaf streak bls also known as black chaff is a common bacterial disease of wheat the disease is caused by the bacterial species xanthomonas translucens pv undulosa the pathogen is found globally but is a primary problem in the us in the lower mid south and can reduce yields by up to 40 percent 6 bls is primarily seed borne the disease is transmitted by seed and survives in and on the seed but may also survive in crop residue in the soil in the off season during the growing season the bacteria may transfer from plant to plant by contact but it is primarily spread by rain wind and insect contact the bacteria thrives in moist environments and produces a cream to yellow bacterial ooze which when dry appears light colored and scale like resulting in a streak on the leaves the invasion of the head of wheat causes bands of necrotic tissue on the awns which is called black chaff 14 the disease is not easily managed as there are no pesticides on the market for treatment of the infection there are some resistant cultivars available but no seed treatment exists some integrated pest management ipm techniques may be used to assist with preventing infection although none will completely prevent the disease 2
bacterial pneumonia is a type of pneumonia caused by bacterial infection
bacterial vaginosis bv is a disease of the vagina caused by excessive growth of bacteria common symptoms include increased vaginal discharge that often smells like fish the discharge is usually white or gray in color burning with urination may occur itching is uncommon occasionally there may be no symptoms having bv approximately doubles the risk of infection by a number of other sexually transmitted infections including hiv aids it also increases the risk of early delivery among pregnant women bv is caused by an imbalance of the naturally occurring bacteria in the vagina there is a change in the most common type of bacteria and a hundred to thousandfold increase in total numbers of bacteria present typically bacteria other than lactobacilli become more common risk factors include douching new or multiple sex partners antibiotics and using an intrauterine device among others however it is not considered a sexually transmitted infection diagnosis is suspected based on the symptoms and may be verified by testing the vaginal discharge and finding a higher than normal vaginal ph and large numbers of bacteria bv is often confused with a vaginal yeast infection or infection with trichomonas usually treatment is with an antibiotic such as clindamycin or metronidazole these medications may also be used in the second or third trimesters of pregnancy however the condition often recurs following treatment probiotics may help prevent re occurrence it is unclear if the use of probiotics or antibiotics affects pregnancy outcomes bv is the most common vaginal infection in women of reproductive age the percentage of women affected at any given time varies between 5 and 70 bv is most common in parts of africa and least common in asia and europe in the united states about 30 of women between the ages of 14 and 49 are affected rates vary considerably between ethnic groups within a country while bv like symptoms have been described for much of recorded history the first clearly documented case occurred in 1894
bacterial wilt is a cucurbit disease caused by the pathogen erwinia tracheiphila a gram negative bacterium in the family enterobacteriaceae cucumber and muskmelon plants are most susceptible but squash pumpkins and gourds may also become infected watermelons are immune to the disease
bacterial wilt of carnations is a bacterial disease caused by the plant pathogen burkholderia caryophylli previously named pseudomonas caryophilli the pathogen is a aerobic gram negative bacteria known for only being capable of entering its host through wounds once inside the host it colonizes the vascular system and roots causing symptoms such as internal stem cracking yellowing of the leaves wilting and the development of cankers as a bacterial disease bacterial wilt of carnations can also be characterized by signs such as bacterial streaming and bacterial ooze
in medicine bacteriuria denotes the presence of bacteria in urine but not if the bacteria s presence is due to contamination from urine sample collection
a bad debt is an amount owed to a creditor that is unlikely to be paid and which the creditor is not willing to take action to collect because of various reasons for example due to a company going into liquidation or insolvency there are various technical definitions of what constitutes a bad debt depending on accounting conventions regulatory treatment and the institution provisioning in the usa bank loans with more than ninety days arrears become problem loans accounting sources advise that the full amount of a bad debt be written off to the profit and loss account or a provision for bad debts as soon as it is foreseen
a bad habit is a negative behaviour pattern common examples include procrastination fidgeting overspending stereotyping gossips bullying and nail biting
the baden 9 kreuzer error is a postage stamp error produced by the historical german state of baden in 1851 baden s first postage stamps were issued on 1 may 1851 the 9 kreuzer green stamp was a color misprint of the 9 kreuzer denomination that was printed in green instead of pink the green color was intended for the 6 kreuzer value but apparently the paper sheets were mismatched only three cancelled copies and one unused copy of this error are known but more sheets of paper may have been printed the cancellations recorded have the numbers 4 for achern 41 for ettenheim and 106 for orschweier today mahlberg two of the known copies are on letters
the baeyer – drewson indigo synthesis 1882 is an organic reaction in which indigo is prepared from 2 nitrobenzaldehyde and acetone baeyer drewson indigo synthesis the reaction is classified as an aldol condensation as a practical route to indigo this method was displaced by routes from aniline
the baeyer villiger oxidation also called baeyer villiger rearrangement is an organic reaction that forms an ester from a ketone or a lactone from a cyclic ketone peroxyacids or peroxides are used as the oxidant the reaction is named after adolf baeyer and victor villiger who first reported the reaction in 1899
bagassosis an interstitial lung disease is a type of hypersensitivity pneumonitis attributed to exposure to moldy molasses bagasse
on the commercial transportation mostly with airlines the baggage allowance is the amount of checked or carry on luggage the airline will allow per passenger on some airlines this is the amount that is allowed free of charge in other cases this is the firm limit and carrying additional weight for an extra payment is not an option
the baggio – yoshinari syndrome bys formerly known as the brazilian lyme like disease and brazilian human borreliosis is a disease transmitted by the amblyomma cajennense tick but the organism that causes the infection is still unknown clinical features resemble those of lyme disease ld
bahima disease is a birth defect caused by iron deficiency in infants which are fed exclusively on cow s milk it is characterized by a tower shaped skull dilatation of the diploe and no signs of thalassaemia sickle cell or other haemolytic anaemia it occurs most frequently in the bahima people in ankole uganda from which it derives its name the bahima are a tribe that relies heavily on herding of long horned cattle for survival
the bainbridge reflex also called the atrial reflex is an increase in heart rate due to an increase in central venous pressure increased blood volume is detected by stretch receptors cardiac receptors located in both atria at the venoatrial junctions
bakanae バカナエ pronounced ba ka na eh or bakanae disease 馬鹿苗病 バカナエビョウ bakanae byou from the japanese for foolish seedling is a disease that infects the rice plant it is caused by the fungus gibberella fujikuroi the metabolism of which produces a surplus of gibberellic acid in the plant this acts as a growth hormone causing hypertrophy the afflicted plants which are visibly etiolated and chlorotic are at best infertile with empty panicles producing no edible grains at worst they are incapable of supporting their own weight topple over and die hence foolish seedling disease the earliest known report of bakanae is from 1828 it was first described scientifically in 1898 by japanese researcher shotaro hori who showed that the causative agent was fungal the fungus affects rice crops in asia africa and north america in epidemic cases yield losses may reach up to 20 or more a 2003 publication from the international rice research institute estimated that outbreaks of bakanae caused crop losses that were 20 to 50 in japan 15 in thailand and 3 7 in india
a baker s cyst also known as a popliteal cyst is a benign swelling of the semimembranosus or more rarely some other synovial bursa found behind the knee joint it is named after the surgeon who first described it william morrant baker 1838 – 1896 this is not a true cyst as an open communication with the synovial sac is often maintained
baker s itch is a cutaneous reaction caused by bites of acarus siro the flour mite
the baker – venkataraman rearrangement is the chemical reaction of 2 acetoxyacetophenones with base to form 1 3 diketones the baker venkataraman rearrangement this rearrangement reaction proceeds via enolate formation followed by acyl transfer it is named after the scientists wilson baker and krishnasami venkataraman the baker – venkataraman rearrangement is often used to synthesize chromones and flavones
balamuthia infection is a cutaneous condition resulting from balamuthia that may result in various skin lesions balamuthia mandrillarisis a free living amoeba a single celled living organism found in the environment it is one of the causes of granulomatous amoebic encephalitis gae a serious infection of the brain and spinal cord balamuthia is thought to enter the body when soil containing it comes in contact with skin wounds and cuts or when dust containing it is breathed in or gets in the mouth the balamuthia amoebae can then travel to the brain through the blood stream and cause gae gae is a very rare disease that is usually fatal scientists at the centers for disease control and prevention cdc first discovered balamuthia mandrillaris in 1986 the amoeba was found in the brain of a dead mandrill after extensive research b mandrillaris was declared a new species in 1993 since then more than 200 cases of balamuthia infection have been diagnosed worldwide with at least 70 cases reported in the united states little is known at this time about how a person becomes infected
in biomechanics balance is an ability to maintain the line of gravity vertical line from centre of mass of a body within the base of support with minimal postural sway sway is the horizontal movement of the centre of gravity even when a person is standing still a certain amount of sway is essential and inevitable due to small perturbations within the body e g breathing shifting body weight from one foot to the other or from forefoot to rearfoot or from external triggers e g visual distortions floor translations an increase in sway is not necessarily an indicator of dysfunctional balance so much as it is an indicator of decreased sensorimotor control maintaining balance requires coordination of input from multiple sensory systems including the vestibular somatosensory and visual systems vestibular system sense organs that regulate equilibrium equilibrioception directional information as it relates to head position internal gravitational linear and angular acceleration somatosensory system senses of proprioception and kinesthesia of joints information from skin and joints pressure and vibratory senses spatial position and movement relative to the support surface movement and position of different body parts relative to each other visual system reference to verticality of body and head motion spatial location relative to objects the senses must detect changes of spatial orientation with respect to the base of support regardless of whether the body moves or the base is altered there are environmental factors that can affect balance such as light conditions floor surface changes alcohol drugs and ear infection there are balance impairments associated with aging age related decline in the ability of the above systems to receive and integrate sensory information contributes to poor balance in older adults as a result the elderly are at an increased risk of falls in fact one in three adults aged 65 and over will fall each year in the case of an individual standing quietly upright the limit of stability is defined as the amount of postural sway at which balance is lost and corrective action is required body sway can occur in all planes of motion which make it an increasingly difficult ability to rehabilitate there is strong evidence in research showing that deficits in postural balance is related to the control of medial lateral stability and an increased risk of falling to remain balanced a person standing must be able to keep the vertical projection of their center of mass within their base of support resulting in little medial lateral or anterior posterior sway ankle sprains are one of the most frequently occurring injuries among athletes and physically active people the most common residual disability post ankle sprain is instability along with body sway mechanical instability includes insufficient stabilizing structures and mobility that exceed the physiological limits functional instability involves recurrent sprains or a feeling of giving way of the ankle it is found that nearly 40 of patients with ankle sprains suffer from instability and an increase in body sway injury to the ankle causes a proprioceptive deficit and impaired postural control individuals with muscular weakness occult instability and decreased postural control are more susceptible to ankle injury than those with better postural control balance can be severely affected in individuals with neurological conditions patients who suffer a stroke or a spinal cord injury for example can struggle with this ability it has also been determined that impaired balance is strongly associated with future function and recovery in some cases particularly in stroke patients additionally balance problems have been identified as the strongest predictor of falls another population where balance is severely affected is parkinson s disease patients a study done by nardone and schieppati 2006 showed that individuals with parkinson s disease problems in balance have been related to a reduced limit of stability and an impaired production of anticipatory motor strategies and abnormal calibration balance can also be negatively affected in a normal population through fatigue in the musculature surrounding the ankles knees and hips studies have found however that muscle fatigue around the hips gluteals and lumbar extensors and knees have a greater effect on postural stability sway it is thought that muscle fatigue leads to a decreased ability to contract with the correct amount of force or accuracy as a result proprioception and kinesthetic feedback from joints are altered so that conscious joint awareness may be negatively effected
in banking and accountancy the outstanding balance is the amount of money owed or due that remains in a deposit account balancing the books refers to the primary balance sheet equation of a l oe or assets liabilities plus owner s equity the first balancing of books or of the balance sheet financial statement in accounting is to check iterations test balances to be sure the equation above applies and where assets and liabilities are unequal to equalize them by debiting or crediting owner s equity i e if assets exceed liabilities equity is increased if liabilities exceed assets equity is decreased both in the amount needed to balance the equation in addition to the balance sheet the other primary financial statement the p l or profit and loss statement also is balanced against the balance sheet generally by use of a plug such as imputed interest no balanse økonomi
a balance disorder is a disturbance that causes an individual to feel unsteady for example when standing or walking it may be accompanied by feelings of giddiness or wooziness or having a sensation of movement spinning or floating balance is the result of several body systems working together the visual system eyes vestibular system ears and proprioception the body s sense of where it is in space degeneration or loss of function in any of these systems can lead to balance deficits
the commercial balance or net exports sometimes symbolized as nx is the difference between the monetary value of a nation s exports and imports over a certain period if a country exports a greater value than it imports it is called a trade surplus positive balance or a favourable balance and conversely if a country imports a greater value than it exports it is called a trade deficit negative balance unfavourable balance or informally a trade gap sometimes a distinction is made between a balance of trade for goods vs one for services
in mathematics and computer science a balanced boolean function is a boolean function whose output yields as many 0 s as 1 s over its input set this means that for a uniformly random input string of bits the probability of getting a 1 is 1 2 an example of a balanced boolean function is the function that assigns a 1 to every even number and 0 to all odd numbers likewise the other way around the same applies for functions assigning 1 to all positive numbers and 0 otherwise a boolean function of n bits is balanced if it takes the value 1 with probability 1 ⁄ 2
a balanced field takeoff is a condition where the accelerate stop distance required asdr is equal to the takeoff distance required todr for the aircraft weight engine thrust aircraft configuration and runway condition for a given aircraft weight engine thrust aircraft configuration and runway condition the shortest runway length that complies with safety regulations is the balanced field length the rejected takeoff initial actions speed v 1 or critical engine failure recognition speed vcef is the fastest speed at which the pilot must take the first actions to reject the takeoff rto at speeds below v 1 the aircraft may be brought to a halt before the end of the runway at v 1 the pilot must continue the takeoff even if an emergency is recognized to achieve a balanced field takeoff engine power is selected to provide enough acceleration so that at the lowest possible speed to continue the takeoff the remaining necessary takeoff distance with one engine not working is equal to the remaining necessary accelerate stop distance the balanced field length is the shortest field length at which a balanced field takeoff can be performed factors affecting the balanced field length include the mass of the aircraft – higher mass results in slower acceleration and higher takeoff speed engine thrust – affected by temperature and air pressure but reduced thrust can also be deliberately selected by the pilot density altitude – reduced air pressure or increased temperature increases minimum take off speed aircraft configuration such as wing flap position runway slope and runway wind component runway conditions – a rough or soft field slows acceleration a wet or icy field reduces braking calculation of the balanced field length traditionally involves relying on an expansion program model where the various forces are evaluated as a function of speed and step wise integrated using an estimate for v 1 the process is iterated with different values for the engine failure speed until the accelerate stop and accelerate go distances are equal this process suffers from the inherently slow and repetitive approach which is also subject to round off errors if the speed increment between the steps is not carefully selected which could cause some issues in first principle aircraft performance models provided to airlines for day to day operations alternate approaches using a more mathematically complex but inherently more accurate and faster algebraic integration method have however been developed
in mathematics the generalized polygamma function or balanced negapolygamma function is a function introduced by olivier espinosa aldunate and victor h moll it generalizes the polygamma function to negative and fractional order but remains equal to it for integer positive orders
balanitis is inflammation of the glans penis when the foreskin is also affected it is termed balanoposthitis balanitis on boys still in diapers must be distinguished from redness caused by ammoniacal dermatitis the word is from the greek βάλανος balanos acorn
balanitis circinata also known as circinate balanitis is a dermatologic manifestation of reactive arthritis sometimes also referred to as reiter syndrome comprising a serpiginous annular dermatitis of the glans penis circinate balanitis is the most common cutaneous manifestation of reactive arthritis however circinate balanitis can also occur independently topical corticosteroid therapy is the most commonly used treatment and topical calcineurin inhibitors have also been used successfully reactive arthritis is characterized by nongonococcal urethritis conjunctivitis and arthritis reactive arthritis belongs to the group of arthritides known as the spondyloarthritides there are two main types of reactive arthritis post venereal and post enteric chlamydia trachomatis is felt to be the most common cause of reactive arthritis in general until recently even the terminology for the condition itself was unclear as multiple eponyms and names have been associated with reactive arthritis in recent years a great deal has been learnt about the epidemiology pathophysiology and treatment of reactive arthritis and chlamydia induced reactive arthritis specifically prospective epidemiologic data suggest that chlamydia induced reactive arthritis is underdiagnosed other truths being actively revealed include data suggesting that the pathogen itself i e chlamydia might play an equally important role or perhaps even more important than the host with disease susceptibility asymptomatic chlamydial infections might be a common cause of reactive arthritis and the two variants of reactive arthritis might respond differently to treatment in spite of the congruent clinical presentation however much about this syndrome remains shrouded in mystery recent data has been suggesting that chlamydia induced reactive arthritis might be a common condition that clinicians are simply failing to recognise therefore an emphasis is placed on disease awareness since viable treatment options are emerging
balanitis plasmacellularis also known as balanoposthitis chronica circumscripta plasmacellularis balanitis circumscripta plasmacellularis plasma cell balanitis plasma cell vulvitis vulvitis circumscripta plasmacellularis zoon s balanitis zoon s erythroplasia and zoon s vulvitis is a cutaneous condition characterized by a benign inflammatory skin lesion characterized histologically by a plasma cell infiltrate a similar condition has been described in women i e zoon s vulvitis although its existence is controversial due to the possibility of diagnostic error in many of the cases that have been reported in the medical literature it is named for j j zoon who characterized it in 1952
balanitis xerotica obliterans bxo also known as lichen sclerosus of penis is a dermatological skin condition affecting the male genitalia it was first described by stuhmer in 1928 though earlier reports describe what may have been the same condition bxo commonly occurs on the foreskin and glans penis atrophic white patches appear on the affected area and commonly a whitish ring of indurated hardened tissue usually forms near the tip that may prevent retraction it has been regarded as identical to lichen sclerosus of penis though this may be incorrect it has also been named leukoplakia of penis and kraurosis of penis
balantidiasis is a protozoan infection caused by infection with balantidium coli
bald sea urchin disease is a bacterial disease known to affect several species of sea urchins on mediterranean sea north atlantic and california coastlines research suggests two pathogens are responsible for the disease listonella anguillarum and aeromonas salmonicida infection generally occurs at the site of an existing physical injury the affected area turns green and spines and other appendages are lost if the lesion remains shallow and covers less than 30 of the animal s surface area the animal tends to survive and eventually regenerates any lost tissue however if the damage is more extensive or so deep that the hard inner test is perforated the disease is fatal
in the dungeons dragons fantasy role playing game a balhannoth is an aberration they are horrid hulking aberration that hunt underground they can blend into ceilings using their camouflage and they attack using their tentacles anti magic auras surround them making them particularly dangerous to player characters that are dependent on magic to survive
balkan endemic nephropathy — also called danubian endemic familial nephropathy defn — is a form of interstitial nephritis it was first identified in the 1920 s among several small discrete communities along the danube river and its major tributaries in the modern countries of croatia bosnia and herzegovina serbia romania and bulgaria
the balking pattern is a software design pattern that only executes an action on an object when the object is in a particular state for example if an object reads zip files and a calling method invokes a get method on the object when the zip file is not open the object would balk at the request in the java programming language for example an illegalstateexception might be thrown under these circumstances there are some specialists in this field who think this is more of an anti pattern than a design pattern if an object cannot support its api it should either limit the api so that the offending call is not available or so that the call can be made without limitation it should be created in a sane state not make itself available until it is in a sane state become a facade and answer back an object that is in a sane state
ball lightning is an unexplained atmospheric electrical phenomenon the term refers to reports of luminous spherical objects which vary from pea sized to several meters in diameter though usually associated with thunderstorms it lasts considerably longer than the split second flash of a lightning bolt many early reports say that the ball eventually explodes sometimes with fatal consequences leaving behind the odor of sulfur until the 1960 s most scientists argued that ball lightning was not a real phenomenon but an urban myth despite numerous reports from throughout the world laboratory experiments can produce effects that are visually similar to reports of ball lightning but how these relate to the natural phenomenon remains unclear scientists have proposed many hypotheses about ball lightning over the centuries scientific data on natural ball lightning are scarce owing to its infrequency and unpredictability the presumption of its existence depends on reported public sightings and has therefore produced somewhat inconsistent findings due to inconsistencies and to the lack of reliable data the true nature of ball lightning remains unknown the first ever optical spectrum of what appears to have been a ball lightning event was published in january 2014 and included a video at high frame rate
ball possession is the amount of time a team possesses the ball during a game of football possession is usually expressed as a percentage for example 60 for team a 40 for team b historically dutch clubs especially ajax were famous for dominating ball possession but more recently fc barcelona of the liga santander became the best in maintaining ball possession germany s fc bayern munich came out second xavi hernandez is considered to be the most possessive player in recent years teams that play possession football often try to press their opponents high in the pitch so to recover the ball rapidly as a result the defensive line of team that play possession football is usually place very high in the pitch around the halfway line and not unusually in the opponents half when the team loses the ball the defensive line must move rapidly otherwise the team may be subject to dangerous counter attacks because of their high defensive line supremacy in ball possession is generally seen as desirable and useful by coaches but it is by no means certain that it can guarantee victory for example italian clubs are extremely successful in european football without putting much emphasis on ball possession
baller – gerold syndrome bgs is a rare genetic syndrome that involves premature fusion of the skull bones and malformations of facial forearm and hand bones the symptoms of baller – gerold syndrome overlap with features of a few other genetics disorders rothmund thomson syndrome and rapadilino syndrome the prevalence of bgs is unknown as there have only been a few reported cases but it is estimated to be less than 1 in a million the name baller gerold comes from the researchers baller and gerold who discovered the first three cases
ballon french pronunciation ​ balɔ̃ is the appearance of being lightweight and light footed while jumping it is a desirable aesthetic in ballet and other dance genres making it seem as though a dancer effortlessly becomes airborne floats in the air and lands softly the name is widely thought to be derived from the french word ballon meaning balloon though it has been dubiously claimed that the name was inspired by french ballet danseur claude balon who was known for performing exceptionally light leaps
a balloon carried light effect is a special effect carried by a balloon which can be fixed with a rope to the ground or free flying
balloon cell nevi are a cutaneous condition characterized histologically by large pale polyhedral balloon cells
the balls into bins problem is a classic problem in probability theory that has many applications in computer science the problem involves m balls and n boxes or bins each time a single ball is placed into one of the bins after all balls are in the bins we look at the number of balls in each bin we call this number the load on the bin and ask what is the maximum load on a single bin obviously it is possible to make the load as small as m n by putting each ball into the least loaded bin the interesting case is when the bin is selected at random or at least partially at random
balmer jump or balmer discontinuity is the difference of intensity of the stellar continuum spectrum on both sides of the limit of the balmer series of hydrogen at 364 6 nm it is caused by electrons being completely ionized directly from the second energy level of a hydrogen atom bound free absorption which creates a continuum absorption at wavelengths shorter than 364 6 nm in some cases the balmer discontinuity can show continuum emission usually when the balmer lines themselves are strongly in emission other hydrogen spectral series also show bound free absorption and hence a continuum discontinuity but the balmer jump in the near uv has been the most observed the strength of the continuum absorption and hence the size of the balmer jump depends on temperature and density in the region responsible for the absorption at cooler stellar temperatures the density most strongly affects the strength of the discontinuity and this can be used to classify stars on the basis of their surface gravity and hence luminosity this effect is strongest in a class stars but in hotter stars temperature has a much larger effect on the balmer jump than surface gravity
balo concentric sclerosis is a disease in which the white matter of the brain appears damaged in concentric layers leaving the axis cylinder intact it was described by joszef balo who initially named it leuko encephalitis periaxialis concentrica from the previous definition and it is currently considered one of the borderline forms of multiple sclerosis balo concentric sclerosis is a demyelinating disease similar to standard multiple sclerosis but with the particularity that the demyelinated tissues form concentric layers scientists used to believe that the prognosis was similar to marburg multiple sclerosis but now they know that patients can survive or even have spontaneous remission and asymptomatic cases it is also common that the clinical course is primary progressive but a relapsing remitting course has been reported it seems that the course gets better with prednisone therapy although evidence of this is anecdotal and such conclusions are difficult to accept given that there are cases where patients spontaneously recover whether the patient was on steroid therapy or not
the baltic fleet балтийский флот is the russian federation navy s presence in the baltic sea in previous historical periods it has been part of the navy of imperial russia and later the union of soviet socialist republics soviet union the fleet gained the twice red banner appellation during the soviet period indicating two awards of the order of the red banner it is headquartered in kaliningrad formerly königsberg in east prussia of imperial germany with its main base in baltiysk and another base at kronshtadt in the gulf of finland established 18 may 1703 under czar peter the great the fleet is the oldest russian navy formation
the baltimore bank riot of 1835 in the major port city of maryland was a violent reaction to the failure of the bank of maryland in 1834 thousands of citizens had lost millions of dollars in savings the riot which lasted from 6 – 9 august attacked the homes and property of a number of former directors of the bank who had been accused of financial misconduct and fraud as well as the federal district courthouse located on battle monument square the baltimore bank riot was one of the most violent and destructive events of civic unrest in any american city prior to the civil war rioters destroyed many of the homes of the city s wealthiest and most prominent citizens and much valuable property was smashed or burned but was later restored the authorities were unable to control the violence and effectively surrendered the city to the mob which was actively or passively supported by numerous bystanders the state of maryland later paid 100 000 in compensation to persons who had lost property in the rioting
the schiemann reaction also called the balz – schiemann reaction is a chemical reaction in which anilines 1 are transformed to aryl fluorides 3 via diazonium fluoroborates 2 named after the german chemists günther schiemann and günther balz this reaction is the preferred route to fluorobenzene and some related derivatives including 4 fluorobenzoic acid the reaction is similar to the sandmeyer reaction which converts diazonium salts to other aryl halides
the bamberger rearrangement is the chemical reaction of n phenylhydroxylamines with strong aqueous acid which will rearrange to give 4 aminophenols it is named for the german chemist eugen bamberger 1857 – 1932 the bamberger rearrangement n phenylhydroxylamines are typically synthesized from nitrobenzenes by reduction using rhodium or zinc
bamboo blossom is a natural phenomenon in which the bamboos in a location blossom and become hung with bamboo seeds in china myanmar and india bamboo blossom was traditionally seen as a curse or an indication of a starvation coming
the bamford – stevens reaction is a chemical reaction whereby treatment of tosylhydrazones with strong base gives alkenes it is named for the british chemist william randall bamford and the scottish chemist thomas stevens stevens 1900 – 2000 the usage of aprotic solvents gives predominantly z alkenes while protic solvent gives a mixture of e and z alkenes as an alkene generating transformation the bamford – stevens reaction has broad utility in synthetic methodology and complex molecule synthesis the bamford stevens reaction the treatment of tosylhydrazones with alkyl lithium reagents is called the shapiro reaction
bamforth – lazarus syndrome is a genetic condition that results in thyroid dysgenesis it is due to recessive mutations in forkhead winged helix domain transcription factor fklh 15 or ttf 2 it is associated with foxe 1
banana xanthomonas wilt bxw or banana bacterial wilt bbw or enset wilt is a bacterial disease caused by xanthomonas campestris pv musacearum after being originally identified on a close relative of banana ensete ventricosum in ethiopia in the 1960 s bxw emanated in uganda in 2001 affecting all types of banana cultivars since then bxw has been diagnosed in central and east africa including banana growing regions of rwanda democratic republic of the congo tanzania kenya burundi and uganda of the numerous diseases infecting bananas bxw alongside banana bunchy top virus has been the most devastating in recent years global concern arose over the livelihoods of african banana farmers and the millions relying on bananas as a staple food when the disease was at its worst between the years 2001 and 2005 it was estimated that in central uganda from 2001 and 2004 there was a 30 52 decrease in banana yield due to bxw infection although extensive management of the disease outbreaks has helped reduce the impact of banana xanthomonas wilt even today bxw continues to a pose a real problem to the banana farmer of central and east africa
banana freckle is a disease caused by the fungus guignardia musae telomorph or phyllosticta musarum anamorph generally the causal agent of disease is referred to as guignardia phyllosticta sp there are several different strains of the fungus that exist to infect different banana varieties around the globe symptoms include yellowing of the tissue and formation of small dark brown spots on the leaves and fruit within the spots conidia or pycnidia can be found banana freckle is easily propagated and spread from plant to plant by rain splash and movement of infected tissue or fruit management of the disease consists of cutting out infected leaves the paper bag method fungicide application and proper sanitation techniques this devastating disease is extremely relevant for the major banana exporting countries of the world in the absence of chemical control there is about a 78 yield loss banana freckle disease needs to be carefully monitored in order to prevent further spread of the disease
band keratopathy is a corneal disease derived from the appearance of calcium on the central cornea this is an example of metastatic calcification which by definition occurs in the presence of hypercalcemia
band rejection is a phenomenon in waveform signals where a certain frequency or range of frequencies are lost or removed from a source signal the term band rejection when used in electronic signal processing refers to the deliberate removal of a known frequency range for instance to compensate for a known source of interference such as noise from mains household electricity a specific frequency is removed using a notch filter in most other senses band rejection is the unintentional loss of signal caused by imperfections in the recording storage or reproduction of a waveform
bandemia refers to an excess of band cells immature white blood cells released by the bone marrow into the blood the icd diagnosis code for bandemia is 288 66 it is a signifier of infection or sepsis or inflammation measurement of it can play a role in the approach to appendicitis
the bandwagon effect is a phenomenon whereby the rate of uptake of beliefs ideas fads and trends increases the more that they have already been adopted by others in other words the bandwagon effect is characterized by the probability of individual adoption increasing with respect to the proportion who have already done so as more people come to believe in something others also hop on the bandwagon regardless of the underlying evidence the tendency to follow the actions or beliefs of others can occur because individuals directly prefer to conform or because individuals derive information from others both explanations have been used for evidence of conformity in psychological experiments for example social pressure has been used to explain asch s conformity experiments and information has been used to explain sherif s autokinetic experiment according to this concept the increasing popularity of a product or phenomenon encourages more people to get on the bandwagon too the bandwagon effect explains why there are fashion trends when individuals make rational choices based on the information they receive from others economists have proposed that information cascades can quickly form in which people decide to ignore their personal information signals and follow the behavior of others cascades explain why behavior is fragile — people understand that they are based on very limited information as a result fads form easily but are also easily dislodged such informational effects have been used to explain political bandwagons
bandwidth is the difference between the upper and lower frequencies in a continuous set of frequencies it is typically measured in hertz and may sometimes refer to passband bandwidth sometimes to baseband bandwidth depending on context passband bandwidth is the difference between the upper and lower cutoff frequencies of for example a band pass filter a communication channel or a signal spectrum in the case of a low pass filter or baseband signal the bandwidth is equal to its upper cutoff frequency bandwidth in hertz is a central concept in many fields including electronics information theory digital communications radio communications signal processing and spectroscopy and is one of the determinants of the capacity of a given communication channel a key characteristic of bandwidth is that any band of a given width can carry the same amount of information regardless of where that band is located in the frequency spectrum for example a 3 khz band can carry a telephone conversation whether that band is at baseband as in a pots telephone line or modulated to some higher frequency
bandwidth smearing is a chromatic aberration of the reconstructed image of a celestial body observed by an astronomical interferometer that occurs because of the frequency bandwidth in fourier terms the different frequencies of the bandwidth probe different spatial frequencies which results in a reconstruct map containing elongated radial features it is overcome by going to higher spectral resolutions or in radioastronomy by using different centres of phase for image reconstruction
the banert cascade is an organic reaction in which an nh 1 2 3 triazole is prepared from a propargyl halide or sulfate and sodium azide in a dioxane water mixture at elevated temperatures this cascade reaction is unusual because it consists of two consecutive rearrangement reactions banert cascade the starting material is prepared from propargyl chloride and an aldehyde or ketone such as acetaldehyde in the first step an azido compound is formed in situ in a nucleophilic displacement of chloride by the azide ion a 3 3 sigmatropic reaction takes place between the azide and the alkyne to the allenyl azide this allene rearranges to the triazafulvene in a 6 pi electrocyclization the exocyclic alkene in this intermediate is very electrophilic because the triazole group has a dipole moment of 5 debye the reaction sequence concludes with nucleophilic attack of a second azide ion on this alkene with more double bond rearrangements and proton abstraction from a proton source
bangstad syndrome is a severe inherited congenital disorder associated with abnormalities of the cell membrane it was characterized in 1989
in bluegrass music a banjo roll or roll is an accompaniment pattern played by the banjo that uses a repeating eighth note arpeggio – a broken chord – that by subdividing the beat keeps time each standard roll pattern is a right hand fingering pattern consisting of eight eighth notes which can be played while holding any chord position with the left hand when used as back up the same pattern can be repeated over and over throughout an entire song with chord changes as required or the roll patterns can be combined with one another and with back up licks the roll patterns can also be used to embellish the vamping style of back up especially when the chords are played high these roll patterns can be used as back up for any song played at any tempo the banjo is commonly played in open tunings such as open g as are all of the examples g dgbd allowing rolls to be practiced on all open strings without fretting rolls are a distinguishing characteristic of scruggs style banjo playing with older styles being more melodic the older style of banjo playing has been described as in phrases and with really no connective tissue between four notes and next four notes sorta like a gallop snuffy jenkins was a little like that old sounding choppy banjo rolls serve a variety of functions within an ensemble the bluegrass banjo roll is a subdivided rhythm that by dissolving the metronomic footing of the music completes the uncoupling of rhythm and meter monroe s string band was already congested with accents and with the rhythms those accents redundantly enforced with its unbroken and continuous stream of notes sharply voiced in bright acid tones the banjo roll broke up this congestion bringing about a kind of rhythmic division of labor in which several strata of rhythm were distributed among the instruments this is not to say that the banjo player does not call upon rhythmic accents if he sic did not his music would seem little more than the mechanical ratta tat tat of a machine gun but he always does so in a matrix which is consistently and thoroughly subdivided from which the idea of the subdivided rhythm is never absent and which has by virtue of its african inspired amalgamation to melodic movement an unusual power to impart the idea to other musicians like the bones of the minstrel band whose precision lent articulation to the ensemble the banjo s flowing sinuous twisting ribbon of notes fills the entire length and breadth of the music outlining its rhythmic infrastructure sharpening and brightening its image running within the music like a stream of water now in a broad torrent now in intricate rivulets below ground — the activity of the roll patterns creates a counter melody which enhances the effectiveness of the melody — banjo rolls the basis of the scruggs style pioneered by earl scruggs were undoubtedly based on classic or fingerpicking banjo itself based upon and simultaneous with mid 1860 s parlor style guitar the word roll has different meanings for different kinds of musicians to guitar players a roll is a broken chord to bluegrass banjo players rolls may start at any point in the pattern or in other words on any finger
a bankart lesion is an injury of the anterior inferior glenoid labrum of the shoulder due to anterior shoulder dislocation when this happens a pocket at the front of the glenoid forms that allows the humeral head to dislocate into it it is an indication for surgery and often accompanied by a hill sachs lesion damage to the posterior humeral head the bankart lesion is named after english orthopedic surgeon arthur sydney blundell bankart 1879 – 1951 a bony bankart is a bankart lesion that includes a fracture in of the anterior inferior glenoid cavity of the scapula bone bankart lesion seen at arthroscopy radiograph showing a bony bankart lesion with stationary fragment at the inferior glenoid ct scan showing a bony bankart lesion at the antero inferior glenoid 3 d ct reconstruction of a bankart lesion which occurred post anterior shoulder dislocation this subject s humerus remains mildly superiorly subluxated fracture marked by a black arrow mri of the shoulder after an anterior dislocation showing a hill sachs lesion and labral bankart lesion
bankruptcy tourism is the phenomenon whereby residents of one country move to another jurisdiction in order to declare a personal bankruptcy there before returning to their original country of residence this is done in order facilitate bankruptcy in a new jurisdiction where the insolvency laws are deemed to be more favourable it is most prevalent in europe where eu laws allow the free movement of residents to other eurozone countries once in the new jurisdiction a person seeking bankruptcy must establish their centre of main interests there in order to qualify as a resident and therefore petition for a successful bankruptcy the issue of bankruptcy tourism has gained notoriety in the republic of ireland due to the recession and property crash there resulting in high levels of debt and personal insolvencies however the phenomenon first emerged in the uk in 2009 when it was reported that german and austrian nationals were moving to kent in order to take advantage of bankruptcy laws in england and wales whilst residing close to eurostar for a discussion of how the english courts have sought to tackle the phenomenon of bankruptcy tourism see bankruptcy tourism is now more synonymous with the republic of ireland where it has become a high profile issue with one uk based insolvency solicitor steve thatcher claiming recently that he had recently written off € 1 bn in irish debt for his irish clients in the uk the level of irish debt being written off in the uk has prompted the government there to seek to have eu law amended in order to make it harder for irish residents to move to the uk and take advantage of more lenient bankruptcy laws there where bankruptcy lasts for a period of twelve months but salary instalments can required for up to three years as opposed to twelve years in the republic of ireland though thatcher dismisses the validity of the term bankruptcy tourism and instead calls it bankruptcy emigration as he says people have to emigrate to the uk in order to go bankrupt with the majority of his clients remaining in the uk once their bankruptcy is complete since ireland has reduced the duration of its insolvency procedures and since 2016 has a 1 year bankruptcy procedure as well however access to such procedures may still be restricted due to barriers such as requirement to pay for legal procedures limited size of the debt or if one already went through a procedure before still england and wales have among the shortest and most accessible procedures in the eu and continues attracting bankruptcy tourism in particular among over indebted people with assets
bannayan – riley – ruvalcaba syndrome brrs is a rare overgrowth syndrome and hamartomatous disorder with occurrence of multiple subcutaneous lipomas macrocephaly and hemangiomas the disease is inherited in an autosomal dominant form but sporadic cases have been reported the disease belongs to a family of hamartomatous polyposis syndromes which also includes peutz – jeghers syndrome juvenile polyposis and cowden syndrome mutation of the pten gene underlies this syndrome as well as cowden syndrome proteus syndrome and proteus like syndrome collectively these four syndromes are referred to as pten hamartoma tumor syndromes phts
banner blindness is a phenomenon in web usability where visitors to a website consciously or subconsciously ignore banner like information which can also be called ad blindness or banner noise the term banner blindness was coined by benway and lane as a result of website usability tests where a majority of the test subjects either consciously or unconsciously ignored information that was presented in banners subjects were given tasks to search information on a website the information that was overlooked included both external advertisement banners and internal navigational banners e g quick links the placement of the banners on a web page had little effect on whether or not the subjects noticed them the result of the study contradicted the popular web design guideline that larger colourful and animated elements on a website are more likely to be seen by users however in older experiment by bayles the results showed that users generally noticed web banners this was proven by eye tracking tests and other means the experiment concentrated on how users perceived a single web page and what they could recognise and recall of it afterwards it has been argued that experiments like this without real world tasks have poor methodology and produce poor results other eye tracking tests showed different results pagendarm and schaumburg argued that a possible explanation for the banner blindness phenomenon lay in the way users interacted with websites users tend to either search for specific information or aimlessly browse from one page to the next users have constructed web related cognitive schemata for different tasks on the web when searching for specific information on a website users focus only on the parts of the page where they assume the relevant information will be e g small text and hyperlinks in particular the study of hervet et al shows a new methodological view which must be taken into account they focus on whether participants actually fixated the ads and how their gaze behaviour is related to memory for the ad they investigated whether internet users avoid looking at ads inserted on a non search website using an analysis of eye movements and if the ad content is kept in memory their results show that most participants fixate the ads at least once during their website visit moreover even though the congruency between the ad and the editorial content had no effect on fixation duration on the ad congruent ads were better memorised than incongruent ads later empirical studies focus on e g the role of animation or effects of personalized banner ads lee anh and park find that animations signal the users the existence of ads and lead to ad avoidance behavior but after repetitive exposures they induce positive user attitude through the mere exposure effect results of the study koster et al confirm that personalization enhances recognition for the content of banners while the effect on attention was weaker and partially nonsignificant in contrast overall exploration of web pages and recognition of task relevant information was not influenced the temporal course of fixations revealed that visual exploration of banners typically proceeds from the picture to the logo and finally to the slogan bad marketing and ads that are not correctly targeted make it more likely for consumers to ignore banners that aim at capturing their attention this phenomenon called purposeful blindness shows that consumers can adapt fast and become good at ignoring marketing messages that are not relevant to them it is a byproduct of inattentional blindness large colourful or animated banners and other graphics are in this case ignored usability tests that compared the perception of banners between groups of subjects searching for specific information and subjects aimlessly browsing seem to support this theory see study a similar conclusion can be drawn from the study of ortiz chaves et al dealt with how right side graphic elements in contrast to purely textual in google adwords affect users visual behavior so the study is focused on people that search something the analysis concludes that the appearance of images does not change user interaction with ads in the scientific literature there are also suggestions how to tackle banner blindness zouharova zouhar and smutny present approach using cognitive behavioral assumption on the basis of which banner display strategy is adapted
banti s syndrome also known as banti s disease is a chronic congestive enlargement of the spleen resulting in premature destruction of the red blood cells by the spleen it is named for guido banti
the banzai pipeline or simply pipeline or pipe is a surf reef break located in hawaii off ehukai beach park in pupukea on o ahu s north shore a reef break is an area in the ocean where waves start to break once they reach the shallows of a reef pipeline is notorious for huge waves which break in shallow water just above a sharp and cavernous reef forming large hollow thick curls of water that surfers can tube ride there are three reefs at pipeline in progressively deeper water further out to sea that activate according to the increasing size of approaching ocean swells
barakat syndrome is a rare disease characterized by hypoparathyroidism sensorineural deafness and renal disease and hence also known as hdr syndrome it was first described by amin j barakat et al in 1977
the barber – layden – power effect blp effect or colloquially bleep is a blast wave phenomenon observed in the immediate aftermath of the successful functioning of air delivered high drag ordnance at the target in common with a typical blast wave the flow field can be approximated as a lead shock wave followed by a self similar subsonic flow field the phenomenon appears to adhere to the basic principles of the sedov solution
examples of barbier reactions are the reaction of propargylic bromide with butanal with zinc metal in water barbier reactionwith a substituted alkyne instead of a terminal alkyne the allene product is favoured the intramolecular barbier reaction with samarium ii iodide barbier reaction the reaction of an allyl bromide with formaldehyde in thf with indium powder barbier reactionthe barbier reaction is accompanied by an allylic rearrangement to a terminal alkene or another allyl bromide in a reaction with benzaldehyde and zinc powder in water barbier reactionthe observed diastereoselectivity for this reaction is erythro threo 83 17
barbiturate dependence develops with regular use of barbiturates this in turn may lead to a need for increasing doses of the drug to get the original desired pharmacological or therapeutic effect barbiturate use can lead to both addiction and physical dependence and as such they have a high potential for abuse psychological addiction to barbiturates can develop quickly the gabaa receptor one of barbiturates main sites of action is thought to play a pivotal role in the development of tolerance to and dependence on barbiturates as well as the euphoric high that results from their abuse the mechanism by which barbiturate tolerance develops is believed to be different from that of ethanol or benzodiazepines even though these drugs have been shown to exhibit cross tolerance with each other the management of a physical dependence on barbiturates is stabilisation on the long acting barbiturate phenobarbital followed by a gradual titration down of dose the slowly eliminated phenobarbital lessens the severity of the withdrawal syndrome and reduces the chances of serious barbiturate withdrawal effects such as seizures antipsychotics are not recommended for barbiturate withdrawal or other cns depressant withdrawal states especially clozapine olanzapine or low potency phenothiazines e g chlorpromazine as they lower the seizure threshold and can worsen withdrawal effects if used extreme caution is required
a barbiturate overdose results when a person takes excessive doses of barbiturates symptoms of an overdose typically include sluggishness incoordination difficulty in thinking slowness of speech faulty judgment drowsiness shallow breaths and staggering in severe cases coma and death can result the lethal dosage of barbiturates varies greatly with tolerance and from one individual to another barbiturate overdose with other cns central nervous system depressants such as alcohol opiates or benzodiazepines is even more dangerous due to additive cns and respiratory depressant effects in the case of benzodiazepines barbiturates also increase the binding affinity of the benzodiazepine binding sites thus leading to an exaggerated benzodiazepine effect this makes predicting the effect of combinations difficult and the same dose of the same drugs will not always produce the same degree of sedation and respiratory depression from one day to the next benzodiazepines increase the frequency of chloride channel opening while barbiturates increase the duration that the chloride pore remains open if a normal pore opened once every 30 seconds to pass one chloride ion a benzodiazepine may cause it to open once every ten seconds while a barbiturate may cause it to remain open until three ions have passed through separately both of these increase the effect of the pore threefold but together the channel would allow three ions to pass every 10 seconds this would exponentially increase the effect of the pore ninefold greater than the sum of the two drugs effects
barcoo fever is an illness once common in the australian outback that is now virtually unknown it was characterised by nausea and vomiting exacerbated by the sight or smell of food and unlike the usual gastro intestinal infections by constipation rather than diarrhoea fever and myalgia were also symptoms severe cases developed inanition and even death it was seen in travelers in the outback rather than in cities or towns but occasionally entire settlements were affected such as occurred in toowoomba in 1903 the aboriginal population knew to avoid the ailment by not drinking from certain water sources and by taking water from soaks or pits dug in the dry sandy bed of a stream it is postulated that the disease may be due to ingestion of cyanobacterial blue green algal toxins in particular cylindrospermopsin a toxin from cylindrospermopsis raciborskii and other cyanobacteria which is a hepatotoxin the symptoms of the disease are consistent with a hepatitis or liver disorder and cylindrospermopsis is known to be widespread in inland australian water sources the toxin is not destroyed by boiling and although it would flavor water this flavor would be masked by tea the common beverage in the australian bush provision of safe drinking water sources in australia with the development of bores and covered tanks to collect rainwater explain the demise of a once common illness
bardet – biedl syndrome bbs is a ciliopathic human genetic disorder that produces many effects and affects many body systems it is characterized principally by obesity retinitis pigmentosa polydactyly hypogonadism and renal failure in some cases historically slower mental processing has also been considered a principal symptom but is now not regarded as such
bare metal stent is a stent without a coating or covering as used in covered stents drug eluting stents it is a mesh like tube of thin wire the first stents licensed for use in cardiac arteries were bare metal – often 316 l stainless steel more recent 2 nd generation stents use cobalt chromium alloy the first stents used in gastrointestinal conditions of the esophagus gastroduodenum biliary ducts and colon were plastic bare metal stents were first brought the clinic in the 1990 s drug eluting stents are often preferred over bare metal stents because the latter carry a higher risk of restenosis the growth of tissue into the stent resulting in vessel narrowing
bare lymphocyte syndrome is a condition caused by mutations in certain genes of the major histocompatibility complex or involved with the processing and presentation of mhc molecules it is a form of severe combined immunodeficiency
bargaining power is the relative ability of parties in a situation to exert influence over each other if both parties are on an equal footing in a debate then they will have equal bargaining power such as in a perfectly competitive market or between an evenly matched monopoly and monopsony there are a number of fields where the concept of bargaining power has proven crucial to coherent analysis game theory labour economics collective bargaining arrangements diplomatic negotiations settlement of litigation the price of insurance and any negotiation in general
the two person bargaining problem is a problem of understanding how two agents should cooperate when non cooperation leads to pareto inefficient results it is in essence an equilibrium selection problem many games have multiple equilibria with varying payoffs for each player forcing the players to negotiate on which equilibrium to target solutions to bargaining come in two flavors an axiomatic approach where desired properties of a solution are satisfied and a strategic approach where the bargaining procedure is modeled in detail as a sequential game
the bargellini reaction is a chemical reaction discovered in 1906 by italian chemist guido bargellini 1879 – 1963 the original reaction was a mixture of the reagents phenol chloroform and acetone in the presence of a sodium hydroxide solution prior to bargellini s research the product attributed to this multi component reaction or mcr had been described as a phenol derivative in chemistry texts at the time however bargellini demonstrated that a carboxylic acid derivative was actually the correct structure later organic chemists have used the reaction as a general method of organic synthesis for highly hindered or bulky morpholinones or piperazinones from ketones particularly acetone and either β amino alcohols or diamines
baritosis is a benign type of pneumoconiosis which is caused by long term exposure to barium dust barium has a high radio opacity and the disease may develop after few months of exposure extremely dense discrete small opacities of 2 – 4 mm diameter sometimes of a star like configuration are seen on the radiograph their distribution is uniform when they are very numerous superimposition may give the impression of confluency but this does not seem to occur in reality the hilar lymph nodes can be very opaque but not enlarged after cessation of exposure there is a gradual clearing of the opacities
bark binding is a disease in trees cured by slitting the bark or cutting it along the grain of the tree
the barking dog is an exothermic chemical reaction that results from the ignition of a mixture of carbon disulfide and nitrous oxide it has been known for centuries in 1853 justus von liebig was using the bright blue flash and the distinctive ‘ woof ’ sound of the demonstration to enthrall his students in simple terms the ‘ barking dog ’ reaction is a combustion process in which a fuel carbon disulfide cs 2 reacts with an oxidizing agent nitrous oxide n 2 o producing heat and elemental sulfur the flame front in the reaction is a zone of very hot luminous gas produced by the reactants decomposing 8 n 2 o 4 cs 2 → s 8 4 co 2 8 n 2
barley yellow dwarf is a plant disease caused by the barley yellow dwarf virus and is the most widely distributed viral disease of cereals it affects the economically important crop species barley oats wheat maize triticale and rice
barnette s conjecture is an unsolved problem in graph theory a branch of mathematics concerning hamiltonian cycles in graphs it is named after david w barnette a professor emeritus at the university of california davis it states that every bipartite polyhedral graph with three edges per vertex has a hamiltonian cycle
barodontalgia commonly known as tooth squeeze and previously known as aerodontalgia is a pain in tooth caused by a change in atmospheric pressure the pain usually ceases at ground level the most common victims are scuba divers because in deep dives pressures can increase by several atmospheres and military pilots because of rapid changes in pilots barodontalgia may be severe enough to cause premature cessation of flights most of the available data regarding barodontalgia is derived from high altitude chamber simulations rather than actual flights barodontalgia prevalence was between 0 7 and 2 in the 1940 s and 0 3 in the 1960 s similarly cases of barodontalgia were reported in 0 3 of high altitude chamber simulations in the luftwaffe the rate of barodontalgia was about 1 case per 100 flight years in the israeli air force during world war ii about one tenth of american aircrews had one or more episodes of barodontalgia in a recent study 8 2 of 331 israeli air force aircrews reported at least one episode of barodontalgia barodontalgia is a symptom of dental disease for example inflammatory cyst in the mandible indeed most of the common oral pathologies have been reported as possible sources of barodontalgia dental caries defective tooth restoration pulpitis pulp necrosis apical periodontitis periodontal pockets impacted teeth and mucous retention cysts one exception is barodontalgia manifested as referred pain from barosinusitis or barotitis media the latter two conditions are generated from pressure changes rather than pressure related flare up of pre existing conditions a meta analysis of studies conducted between 2001 and 2010 revealed a rate of 5 episodes 1 000 flight years maxillary and mandibular dentitions were affected equally in flight but in diving maxillary dentition was affected more than the mandibular dentition which can indicate a greater role for maxillary sinus pathology in diving barodontalgia surprisingly despite cabin pressurization the current in flight barodontalgia incidence is similar to the incidence in the first half of the 20 th century also despite the greater fluctuation in divers pressures the weighted incidence of barodontalgia among aircrews is similar to the weighted incidence among divers furthermore contrary to common belief and in contrast to diving conditions the role of facial barotrauma in the etiology of in flight barodontalgia is only minor about one tenth of cases
barognosis or baresthesia is the ability to evaluate the weight of objects or to differentiate objects of different weights by holding or lifting them it is the opposite of baragnosis the inability of evaluating the weight of objects this sensory information is transmitted by the posterior column medial lemniscus pathway of the spinal cord which also carries the sensations of fine touch stereognosis tactile pressure graphesthesia texture recognition kinesthesia two point discrimination proprioception and vibration to test for intact barognosis a set of small objects with the same size and shape but of graduated weight is used a series of different weights can be placed one at a time in the same hand and the patient is asked to identify the comparative weight of the objects i e by saying whether the object is heavier or lighter other methods for testing include different weights being placed in each hand simultaneously or having the patient pick up each weight using a fingertip grip
barotrauma is physical damage to body tissues caused by a difference in pressure between a gas space inside or in contact with the body and the surrounding fluid barotrauma typically occurs when the organism is exposed to a significant change in ambient pressure such as when a scuba diver a free diver or an airplane passenger ascends or descends or during uncontrolled decompression of a pressure vessel but can also be caused by a shock wave whales and dolphins are also vulnerable to barotrauma if exposed to rapid and excessive changes in diving pressures bats can be killed by barotrauma due to lung damage when flying in low pressure regions close to operating wind turbine blades
barraquer – simons syndrome or acquired partial lipodystrophy cephalothoracic lipodystrophy and progressive lipodystrophy is a rare form of lipodystrophy which usually first affects the head and then spreads to the thorax it is named for luis barraquer roviralta 1855 – 1928 a spanish physician and arthur simons 1879 – 1942 a german physician some evidence links it to lmnb 2
barrett s esophagus british english barrett s oesophagus sometimes called barrett syndrome barrett esophagus or columnar epithelium lined lower oesophagus cello refers to an abnormal change metaplasia in the cells of the lower portion of the esophagus it is characterized by the replacement of the normal stratified squamous epithelium lining of the esophagus by simple columnar epithelium with goblet cells which are usually found lower in the gastrointestinal tract the medical significance of barrett s esophagus is its strong association about 0 5 per patient year with esophageal adenocarcinoma a very often deadly cancer because of which it is considered to be a premalignant condition the main cause of barrett s esophagus is thought to be an adaptation to chronic acid exposure from reflux esophagitis the incidence of esophageal adenocarcinoma has increased substantially in the western world in recent years the condition is found in 5 – 15 of patients who seek medical care for heartburn gastroesophageal reflux disease although a large subgroup of patients with barrett s esophagus do not have symptoms diagnosis requires endoscopy more specifically esophagogastroduodenoscopy a procedure in which a fibreoptic cable is inserted through the mouth to examine the esophagus stomach and duodenum and biopsy the cells of barrett s esophagus after biopsy are classified into four general categories nondysplastic low grade dysplasia high grade dysplasia and frank carcinoma high grade dysplasia and early stages of adenocarcinoma can be treated by endoscopic resection and new endoscopic therapies such as radiofrequency ablation whereas advanced stages submucosal are generally advised to undergo surgical treatment nondysplastic and low grade patients are generally advised to undergo annual observation with endoscopy with radiofrequency ablation as a therapeutic option in high grade dysplasia the risk of developing cancer might be at 10 per patient year or greater the condition is named after the australian born british thoracic surgeon norman barrett 1903 – 1979 who described it in 1950
in constrained optimization a field of mathematics a barrier function is a continuous function whose value on a point increases to infinity as the point approaches the boundary of the feasible region of an optimization problem such functions are used to replace inequality constraints by a penalizing term in the objective function that is easier to handle the two most common types of barrier functions are inverse barrier functions and logarithmic barrier functions resumption of interest in logarithmic barrier functions was motivated by their connection with primal dual interior point methods
barrier grid animation also known as picket fence animation and often referred to by the genericized trademark scanimation is an animation effect created by moving a striped acetate overlay across an interlaced image
barrier resilience is an algorithmic optimization problem in computational geometry motivated by the design of wireless sensor networks in which one seeks a path through a collection of barriers often modeled as unit disks that passes through as few barriers as possible
barry cohen born c 1938 is a criminal personal injury civil and qui tam attorney in florida s tampa bay area cohen was hired by the council on american – islamic relations cair to represent the family of ibragim todashev an unarmed chechen shot to death while being questioned by the fbi in relation to the boston marathon bombing he has been characterized as a fighter for his aggressive legal tactics according to the tampa tribune “ the most telling indication of barry ’ s courtroom reputation is this when judges and lawyers need an attorney it is barry they often hire ”
bart syndrome is a genetic disorder characterized by the association of congenital localized absence of skin epidermolysis bullosa lesions of the mouth mucosa and dystrophic nails
barth syndrome bths also known as 3 methylglutaconic aciduria type ii is an x linked genetic disorder the disorder which affects multiple body systems is diagnosed almost exclusively in males it is named after dutch pediatric neurologist peter barth
a bartholin s cyst also known as bartholinitis occurs when a bartholin s gland is blocked and the gland becomes inflamed sizes range from that of a pea to that of an egg and form just within each side of the lower part of the opening of the vagina an abscess may form if the cyst becomes infected in this case it often becomes red and painful when touched a bartholin s cyst is not an infection although it can be caused by an infection inflammation or physical blockage mucus or other impediment to the bartholin s ducts tubes which lead from the glands to the vulva if infection sets in the result is a bartholin s abscess cysts are not sexually transmitted there is no known reason for their development and infection is rare with an abscess a bacterial infection but usually not an std is the cause treatment depends on the severity of symptoms if there are no symptoms no treatment may be needed if a cyst is causing problems drainage is recommended the preferred method of drainage is the insertion of a word catheter for four weeks simple incision and drainage may allow the cyst to reform a surgical procedure known as marsupialization may be used for cysts but should not be used if they are infected if the problems persist the entire gland may be removed removal is sometimes recommended in those older than 40 to ensure cancer is not present antibiotics are not generally needed bartholin s cysts are most likely in women of childbearing age about two percent of women have the problem at some point in their life
bartholin gland carcinoma is an uncommon type of malignancy in the bartholin gland that accounts for 1 of all vulvar malignant neoplasms it is most common in women in their mid 60 s the tumor can become large before a woman is aware of symptoms one of the first symptoms can be dyspareunia in other instances a woman may find a mass or ulcer in the vulva area many clincians assume that an enlarged bartholin gland is malignant in postmenopausal woman until proven otherwise the growth of the tumor can spread to nearby areas such as the ischiorectal fossa and inguinal lymph nodes approximately 50 of bartholin gland carcinomas originate from squamous cell carcinomas another uncommon characteristic of bartholin gland malignancies is that the growth of a lesion originates from the three types of epithelial tissue present in the gland mucinous transitional and squamous
the bartoli indole synthesis also called the bartoli reaction is the chemical reaction of ortho substituted nitroarenes with vinyl grignard reagents to form substituted indoles the bartoli indole synthesis the reaction is unsuccessful without substitution ortho to the nitro group three equivalents of the vinyl grignard reagent are also necessary for good yields this method has become one of the shortest and most flexible routes to 7 substituted indoles the leimgruber batcho indole synthesis gives similar flexibility and regiospecificity to indole derivatives one advantage of the bartoli indole synthesis is the ability to produce indoles substituted on both the carbocyclic ring and the pyrrole ring which is difficult to do with the leimgruber batcho indole synthesis
a barton s fracture is an intra articular fracture of the distal radius with dislocation of the radiocarpal joint there exist two types of barton s fracture dorsal and palmar the latter being more common the barton s fracture is caused by a fall on an extended and pronated wrist increasing carpal compression force on the dorsal rim intra articular component distinguishes this fracture from a smith s or a colles fracture treatment of this fracture is usually done by open reduction and internal fixation with a plate and screws but occasionally the fracture can be treated conservatively
the barton decarboxylation is a radical reaction in which a carboxylic acid is first converted to a thiohydroxamate ester commonly referred to as a barton ester the product is then heated in the presence of a radical initiator and a suitable hydrogen donor to complete the reductive decarboxylation of the initial carboxylic acid using this reaction it is possible to remove a carboxylic acid moiety from an alkyl group and replace it with other functional groups see scheme 1 this reaction is named after its developer the british chemist and nobel laureate sir derek barton 1918 – 1998
the barton reaction also known as the barton nitrite ester reaction is a photochemical reaction that involves the photolysis of an alkyl nitrite to form a δ nitroso alcohol discovered in 1960 the reaction is named for its discoverer nobel laureate sir derek barton barton ’ s nobel prize in chemistry in 1969 was awarded for his work on understanding conformations of organic molecules work which was key to realizing the utility of the barton reaction the barton reaction involves a homolytic ro – no cleavage followed by δ hydrogen abstraction free radical recombination and tautomerization to form an oxime selectivity for the δ hydrogen is a result of the conformation of the 6 membered radical intermediate often the site of hydrogen atom abstraction can be easily predicted this allows the regio and stereo selective introduction of functionality into complicated molecules with high yield due to its then unique ability to derivitize otherwise inert substrates barton used this reaction extensively in the 1960 s to create a number of unnatural steroid analogues while the barton reaction has not enjoyed the popularity or widespread use of many other organic reactions together with the mechanistically similar hofmann – löffler reaction it represents one of the first examples of c h activation chemistry a field which is now the topic of much frontline research in industrial and academic chemistry circles
bartonellosis is an infectious disease produced by bacteria of the genus bartonella bartonella species cause diseases such as carrión ´ s disease trench fever cat scratch disease bacillary angiomatosis peliosis hepatis chronic bacteremia endocarditis chronic lymphadenopathy and neurological disorders
the barton – kellogg reaction is a coupling reaction between a diazo compound and a thioketone through a diazo intermediate forming an alkene the barton – kellogg reaction is also known as barton – kellogg olefination and barton olefin synthesis the barton kellogg reaction this reaction was pioneered by hermann staudinger and the reaction also goes by the name staudinger type diazo thioketone coupling
the barton – mccombie deoxygenation is an organic reaction in which an hydroxy functional group in an organic compound is replaced by a hydrogen to give an alkyl group it is named for the british chemists sir derek harold richard barton 1918 – 1998 and stuart w mccombie the barton mccombie deoxygenation this deoxygenation reaction is a radical substitution in the related barton decarboxylation the reactant is a carboxylic acid
bartter syndrome is a rare inherited defect in the thick ascending limb of the loop of henle it is characterized by low potassium levels hypokalemia increased blood ph alkalosis and normal to low blood pressure there are two types of bartter syndrome neonatal and classic a closely associated disorder gitelman syndrome is milder than both subtypes of bartter syndrome
bart – pumphrey syndrome also known as palmoplantar keratoderma with knuckle pads and leukonychia and deafness is a cutaneous condition characterized by hyperkeratoses knuckle pads over the metacarpophalangeal proximal and distal interphalangeal joints it was characterized in 1967 it can be associated with gjb 2
basal cell carcinoma bcc also known as basalioma or basal cell cancer is the most common skin cancer and one of the most common cancers in the united states while bcc has a very low metastatic risk this tumor can cause significant disfigurement by invading surrounding tissues
basal ganglia disease refers to a group of physical dysfunctions that occur when the group of nuclei in the brain known as the basal ganglia fail to properly suppress unwanted movements or to properly prime upper motor neuron circuits to initiate motor function research indicates that increased output of the basal ganglia inhibits thalamocortical projection neurons proper activation or deactivation of these neurons is an integral component for proper movement if something causes too much basal ganglia output then the thalamocortical projection neurons become too inhibited and one cannot initiate voluntary movement these disorders are known as hypokinetic disorders however a disorder leading to abnormally low output of the basal ganglia leads to relatively no inhibition of the thalamocortical projection neurons this situation leads to an inability to suppress unwanted movements these disorders are known as hyperkinetic disorders currently reasons for abnormal increases or decreases of basal ganglia output are poorly understood one possible factor could be the natural accumulation of iron in the basal ganglia causing neurodegeneration due to its involvement in toxic free radical reactions though motor disorders are the most common associated with the basal ganglia recent research shows that basal ganglia disorders can lead to other dysfunctions such as obsessive compulsive disorder ocd and tourette syndrome
a basaloid follicular hamartoma is a cutaneous condition characterized as distinctive benign adnexal tumor that has several described variants
basic aromatic rings are aromatic rings in which the lone pair of electrons of a ring nitrogen atom is not part of the aromatic system and extends in the plane of the ring this lone pair is responsible for the basicity of these nitrogenous bases similar to the nitrogen atom in amines in these compounds the nitrogen atom is not connected to a hydrogen atom basic aromatic compounds get protonated and form aromatic cations e g pyridinium under acidic conditions typical examples of basic aromatic rings are pyridine or quinoline several rings contain basic as well as non basic nitrogen atoms e g imidazole and purine in non basic aromatic rings the lone pair of electrons of the nitrogen atom is delocalized and contributes to the aromatic pi electron system in these compounds the nitrogen atom is connected to a hydrogen atom examples of non basic nitrogen containing aromatic rings are pyrrole and indole the basic aromatic rings purines and pyrimidines are nucleobases found in dna and rna
basidiobolomycosis is a fungal disease it is caused by basidiobolus ranarum treatment with itraconazole has been described
a basilar skull fracture or basal skull fracture is a fracture of the base of the skull typically involving the temporal bone occipital bone sphenoid bone and or ethmoid bone this type of fracture is rare occurring as the only fracture in just 4 of severe head injury patients such fractures can cause tears in the membranes surrounding the brain or meninges with resultant leakage of the cerebrospinal fluid csf the leaking fluid may accumulate in the middle ear space and dribble out through a perforated eardrum csf otorrhea or into the nasopharynx via the eustachian tube causing a salty taste csf may also drip from the nose csf rhinorrhea in fractures of the anterior skull base yielding a halo sign these signs are characteristic for basilar skull fractures
basketball at the 1936 summer olympics was the first appearance of the sport as an official medal event the tournament was played between 7 august and 14 august 1936 in berlin germany 23 nations entered the competition making basketball the largest tournament of the team sports the international basketball federation which is the governing body of international basketball used the 1936 tournament to experiment with outdoor basketball lawn tennis courts were used for the competition this caused problems when the weather was adverse especially during the final game the medals were awarded by james naismith the inventor of basketball all went to north american teams
basketball at the 1948 summer olympics was the second appearance of the sport as an official medal event a total number of 23 nations entered the competition olympic basketball returned to indoor competition in harringay arena after the disastrous weather conditions of the final game in the 1936 summer olympics
basketball at the 1952 summer olympics was the third appearance of the sport 23 nations entered the competition the top six teams at the 1948 summer olympics qualified automatically as did the 1950 world champion argentina the top two at the 1951 european championships ussr and czechoslovakia and the host country finland thirteen other nations competed in a preliminary round to determine the last six places in the sixteen team olympic tournament basketball
basketball at the 1956 summer olympics was the fourth appearance of the sport in olympic competition fifteen nations an unusually low number for the basketball tournament competed in the event with 174 participants a total number of 56 games of basketball were played the teams were divided into four pools with four teams in three of the pools and only three in the fourth every team played against each other team in its pool once the top two teams from each pool advanced to the quarterfinals where again they were split into pools of four teams again played every other team in their pool with the top two in each advancing to the semifinal and the bottom two entering a pool for 5 th through 8 th places eliminated teams also played in consolation matches with the same structure as the quarterfinals and finals but for 9 th through 15 th places the games were held at the royal exhibition building
basketball at the 1960 summer olympics was the fifth appearance of the sport in olympic competition 16 nations were admitted into the olympic tournament with many others being eliminated in a pre olympic tournament held earlier in the year from 13 to 20 august 1960 at the sports palace at bologna 64 games of basketball were played in the olympic tournament that was held at the sports arena and sports palace both in rome the 16 teams were split up into four groups for the preliminary round each team played every other team in its group once the top two teams in each group advanced to the semifinals in two pools of four while the lower two teams were sent to a consolation semifinal for 9 th through 16 th place in the semifinal each team again played every other team in its pool none of which it had played against previously the top two teams in each of the two semifinals moved on to the final with the lower two teams in each playing in a classification for 5 th through 8 th place the consolation semifinal worked the same way with the top two teams moving into a classification for 9 th through 12 th place and the lower two playing in classification for 13 th through 16 th places for the final each of the four teams had already played against one of the other three in the semifinal the results of those games carried over into the final and each team played the remaining two finalists once even though the teams may have played each other in the preliminary round those results were not carried over the results of that pool determined final ranking each of the classifications worked identically to the final
basopenia or basocytopenia is a form of agranulocytosis associated with a deficiency of basophils one cause is urticaria it has been proposed as an indicator of ovulation it is difficult to detect without flow cytometry because normal levels are so low it can be defined as less than 0 01 x 10 − 9 l
basophilia is a condition where the basophil quantity is abnormally elevated more than 1010 basophils per liter of blood basophilia is associated with pruritis itching due to the basophils release of histamine
in schenkerian analysis the bass arpeggiation de bassbrechung is the bass pattern forming the deep background of tonal musical works it consists in scale steps de stufen i v i each of which may span hundreds of measures of music in the foreground the bass pattern is an arpeggiation in the sense that its middle note v first arises as the fifth of the elaborated chord i of which it is the upper fifth divider it is only when it meets with the passing note scale degree 2 of the fundamental line that v becomes an independent chord within the first one see also schenkerian analysis the arpeggiation of the bass and the divider at the fifth the bass arpeggiation properly speaking consists in the three scale steps i v i exclusively but it may be elaborated at a remote level see schenkerian analysis elaboration of the bass arpeggiation
a bass chorus is an electronic effect used with the electric bass it creates the same shimmering sound as a chorus effect for electric guitar chorus pedals the difference is that bass chorus pedals are modified in various ways to suit the low pitch register of the electric bass while several bass chorus pedal manufacturers have modified the chorus circuit so that it does not affect the lower register others have designed the effect so that it can have an effect on even very low pitches the requirements for a chorus effect using a pedal or effect unit can vary depending on the type of instrument being used bass is a perfect example because it operates at a lower frequency range than a guitar as such a standard multi level chorus can make the sound of the bass notes much thinner this problem can be corrected by either mixing more of the un affected signal into the mix or by increasing the amount of bass frequency chorused in the sound pedals such as the i 90 chorus from bass amplifier manufacturer eden electronics allow the musician to control both of these elements
basso profondo italian deep bass sometimes basso profundo or contrabass is the bass voice subtype with the lowest vocal range while the new grove dictionary of opera defines a typical bass as having a range that is limited to the second e below middle c e 2 operatic basso profondos can be called on to sing low c c 2 such as in the role of baron ochs in der rosenkavalier often choral composers make use of lower notes such as g 1 or even f 1 in such rare cases the choir relies on exceptionally deep ranged basso profondos termed oktavist or octavist who sometimes sing an octave below the bass part
bastar dussehra is the unique cultural trait of chhattisgarh celebrated by the local people of the state with sufficient vigor the festival of dussehra connotes to the supreme power of goddess danteswari during dussera the inhabitants of bastar organizes special worship ceremonies at the danteswari temple of jagadalpur
the bastian – bruns sign or bastian bruns law is the loss of tone and deep tendon reflexes in the lower limbs in the presence of complete transection of the spinal cord above the level of the lumbar enlargement the sign was named after henry charlton bastian and ludwig bruns
bathroom singing also known as singing in the bathroom singing in the bath or singing in the shower is a widespread phenomenon many people sing in the bathroom because the hard wall surfaces often tiles or wooden panels and lack of soft furnishings create an aurally pleasing acoustic environment the multiple reflections from walls enrich the sound of one s voice small dimensions and hard surfaces of a typical bathroom produce various kinds of standing waves reverberation and echoes giving the voice fullness and depth this habit was reported with an attempt of explanations centuries ago for example ibn khaldun in chapter 1 of his muqaddimah writes likewise when those who enjoy a hot bath inhale the air of the bath so that the heat of the air enters their spirits and makes them hot they are found to experience joy it often happens that they start singing as singing has its origin in gladness the bathroom singer is an ironic reference to mediocre or amateur singers jon anderson had tiles installed in the studio to simulate the echo effect of one s vocals in a bathroom this effect was not used only by singers paul simon wrote the main thing about playing the guitar though was that i was able to sit by myself and play and dream and i was always happy doing that i used to go off in the bathroom because the bathroom had tiles so it was a slight echo chamber i d turn on the faucet so that water would run – i like that sound it s very soothing to me – and i d play in the dark hello darkness my old friend i ve come to talk with you again weird al yankovic in fact in 1979 recorded his first single my bologna in the bathroom across from the california polytechnic state university student radio station where he was djing at the time there s more to life than this the fourth track on björk s 1993 album debut was recorded live in the toilets of the milk bar clubnight london
batten disease is an extremely rare and fatal autosomal recessive neurodegenerative disorder that begins in childhood it is the most common form of a group of disorders called the neuronal ceroid lipofuscinoses ncls although batten disease is usually regarded as the juvenile form of ncl or type 3 some physicians use the term batten disease to describe all forms of ncl historically the ncls were classified by age of disease onset as infantile ncl incl late infantile ncl lincl juvenile ncl jncl or adult ncl ancl at least twenty genes have been identified in association with batten disease but juvenile ncl the most prevalent form of batten disease has been linked to mutations in the cln 3 gene
battenburg markings or battenberg markings are a pattern of high visibility markings used primarily on the sides of emergency service vehicles in several european countries australia new zealand and hong kong the name comes from the similarity in appearance to the cross section of a battenberg cake
battered person syndrome is a physical and psychological condition of a person who has suffered usually persistent emotional physical or sexual abuse from another person it is classified as icd 9 code 995 81 battered person syndrome not elsewhere classified nec the condition is the basis for the battered spouse defense that has been used in cases of physically and psychologically abused spouses who have killed their abusers the condition was first researched extensively by lenore e walker who used martin seligman s learned helplessness theory to explain why abused spouses stayed in destructive relationships
the battle of garisi was fought between the georgian and safavid iranian armies at the village of garisi present day tetritsq aro in 1556 or 1558 and resulted in a pyrrhic victory of the georgians this conflict was an immediate consequence of the treaty of amasya signed between the ottoman and safavid empires in 1555 this peace deal left a fragmentized kingdom of georgia divided into spheres of influence the kingdoms of kartli and kakheti and the eastern part of the principality of samtskhe were allotted to the safavids which had already garrisoned the georgian capital of tbilisi luarsab i the indomitable king of kartli refused to recognize the terms of the amasya treaty and continued to worry tbilisi this provoked another iranian expedition the fourth in luarsab ’ s reign the safavid forces the qizilbash placed by shah tahmasp i under the command of shāhverdī khān ziyādoghlū qājār beylerbey of karabakh crossed into kartli in 1556 or 1558 lursab and his son svimon met the invaders at garisi in a pitched battle the georgians managed to beat off the qizilbash but luarsab was killed in action
the battle of seacroft moor on 30 march 1643 was a decisive loss for the parliamentary forces during the first english civil war it took place near seacroft north east of leeds west yorkshire england the battle reportedly turned the cock beck which ran through the battlefield red with the casualties blood for several days
battleshort sometimes battle short is a condition in which some military equipment can be placed so it does not shut down when circumstances would be damaging to the equipment or personnel the origin of the term is to bridge or short the fuses of an electrical apparatus before entering combat so that the fuse blowing will not stop the equipment from operating according to allied ordnance publication aop 38 3 a nato publication a battleshort is the capability to bypass certain safety features in a system to ensure completion of the mission without interruption due to the safety feature it also says examples of bypassed safety features are circuit overload protection and protection against overheating in peaceful situations one would want equipment to shut down so it is not damaged in a battle or emergency where the survival of the vessel or other vehicle is dependent upon the continued operation of the equipment it is sometimes wiser to risk equipment damage than have the equipment shut down when it is needed for example the electrical drives to elevate and traverse the guns of a combat warship may have battleshort fuses which are simply copper bars of the correct size to fit the fuse holders as failure to return fire in a combat situation may cause loss of the ship and crew and damaging or overheating of the electrical motors is a preferable alternative battleshorts have been used in some non combat situations as well including the firing room mission control spaces at nasa during the manned apollo missions — specifically the moon landings
baumol s cost disease or the baumol effect is a phenomenon described by william j baumol and william g bowen in the 1960 s it involves a rise of salaries in jobs that have experienced no increase of labor productivity in response to rising salaries in other jobs that have experienced the labor productivity growth this pattern seemingly goes against the theory in classical economics for which real wage growth is closely tied to labor productivity changes the rise of wages in jobs without productivity gains is from the requirement to compete for employees with jobs that have experienced gains and so can naturally pay higher salaries just as classical economics predicts for instance if the retail sector pays its managers 19 th century style salaries the managers may decide to quit to get a job at an automobile factory where salaries are higher because of high labor productivity thus managers salaries are increased not by labor productivity increases in the retail sector but by productivity and corresponding wage increases in other industries the original study was conducted for the performing arts sector baumol and bowen pointed out that the same number of musicians is needed to play a beethoven string quartet today as was needed in the 19 th century the productivity of classical music performance has not increased on the other hand the real wages of musicians like in all other professions have increased greatly since the 19 th century in a range of businesses such as the car manufacturing sector and the retail sector workers are continually becoming more productive by technological innovations to their tools and equipment in contrast in some labor intensive sectors that rely heavily on human interaction or activities such as nursing education or the performing arts there is little or no growth in productivity over time as with the string quartet example it takes nurses the same amount of time to change a bandage or college professors the same amount of time to mark an essay in 2006 as it did in 1966 as those types of activities rely on the movements of the human body which cannot be engineered to perform more quickly accurately or efficiently in the same way that a machine such as a computer can baumol s cost disease is often used to describe consequences of the lack of growth in productivity in the quaternary sector of the economy and public services such as public hospitals and state colleges since many public administration activities are heavily labor intensive there is little growth in productivity over time because productivity gains come essentially from a better capital technology
bauxite pneumoconiosis also known as shaver s disease corundum smelter s lung bauxite lung or bauxite smelters disease is a progressive form of pneumoconiosis caused by exposure to bauxite fumes which contain aluminium and silica particulates it is typically seen in workers involved in the smelting of bauxite to produce corundum
bayoud disease is an epiphytic fungal disease of date palm the pathogen responsible for the disease is fusarium oxysporum f sp albedinis the disease was first reported from morocco in 1870 the word bayoud is derived from the arabic abiadh white and is a reference to the whitish discoloration of diseased fronds
bazex – dupré – christol syndrome also known as bazex syndrome and follicular atrophoderma and basal cell carcinomas is a very rare condition inherited in an x linked dominant fashion physical findings typically include follicular atrophoderma multiple basal cell carcinomas hypotrichosis and hypohidrosis this condition should not be confused with the unrelated condition acrokeratosis paraneoplastica of bazex which may also be referred to bazex syndrome
bcrypt is a password hashing function designed by niels provos and david mazières based on the blowfish cipher and presented at usenix in 1999 besides incorporating a salt to protect against rainbow table attacks bcrypt is an adaptive function over time the iteration count can be increased to make it slower so it remains resistant to brute force search attacks even with increasing computation power the bcrypt function is the default password hash algorithm for openbsd and other systems including some linux distributions such as suse linux the prefix 2 a or 2 b or 2 y in a hash string in a shadow password file indicates that hash string is a bcrypt hash in modular crypt format the rest of the hash string includes the cost parameter a 128 bit salt base 64 encoded as 22 characters and 184 bits of the resulting hash value base 64 encoded as 31 characters the cost parameter specifies a key expansion iteration count as a power of two which is an input to the crypt algorithm for example the shadow password record 2 a 10 n 9 qo 8 uloickgx 2 zmrzomyeijzagcfl 7 p 92 ldgxad 68 ljzdl 17 lhwy specifies a cost parameter of 10 indicating 210 key expansion rounds the salt is n 9 qo 8 uloickgx 2 zmrzomye and the resulting hash is ijzagcfl 7 p 92 ldgxad 68 ljzdl 17 lhwy per standard practice the user s password itself is not stored there are implementations of bcrypt for c c java javascript perl php python ruby nodejs and other languages
beare – stevenson cutis gyrata syndrome is a rare genetic disorder characterized by craniosynostosis premature fusion of certain bones of the skull sometimes resulting in a characteristic cloverleaf skull further growth of the skull is prevented and therefore the shape of the head and face is abnormal and a specific skin abnormality called cutis gyrata characterized by a furrowed and wrinkled appearance particularly in the face and on the palms and soles of the feet thick dark velvety areas of skin acanthosis nigricans are sometimes found on the hands and feet and in the groin additional signs and symptoms of beare – stevenson cutis gyrata syndrome can include a blockage of the nasal passages choanal atresia overgrowth of the umbilical stump and abnormalities of the genitalia and anus the medical complications associated with this condition are often severe and may well be life threatening in infancy or early childhood
in acoustics a beat is an interference pattern between two sounds of slightly different frequencies perceived as a periodic variation in volume whose rate is the difference of the two frequencies when tuning instruments that can produce sustained tones beats can readily be recognized tuning two tones to a unison will present a peculiar effect when the two tones are close in pitch but not identical the difference in frequency generates the beating the volume varies like in a tremolo as the sounds alternately interfere constructively and destructively as the two tones gradually approach unison the beating slows down and may become so slow as to be imperceptible
beau s lines are deep grooved lines that run from side to side on the fingernail or the toenail they may look like indentations or ridges in the nail plate this condition of the nail was named by a french physician joseph honoré simon beau 1806 – 1865 who first described it in 1846 beau s lines are horizontal going across the nail and should not be confused with vertical ridges going from the bottom cuticle of the nail out to the fingertip these vertical lines are usually a natural consequence of aging and are harmless beau s lines should also be distinguished from muehrcke s lines of the fingernails while beau s lines are actual ridges and indentations in the nail plate muehrcke lines are areas of hypopigmentation without palpable ridges they affect the underlying nail bed and not the nail itself beau s lines should also be distinguished from mees lines of the fingernails which are areas of discoloration in the nail plate there are several causes of beau s lines it is believed that there is a temporary cessation of cell division in the nail matrix this may be caused by an infection or problem in the nail fold where the nail begins to form or it may be caused by an injury to that area some other reasons for these lines include trauma coronary occlusion hypocalcaemia and skin disease they may be a sign of systemic disease or may also be caused by an illness of the body as well as drugs used in chemotherapy or malnutrition beau s lines can also be seen one to two months after the onset of fever in children with kawasaki disease human nails grow at a rate which varies with many factors age sex and the finger or toe in question as well as nutrition however typically in healthy populations fingernails grow at about 0 1 mm day and toenails at about 0 05 mm day with this in mind the date of the stress causing beau s lines and other identifiable marks on nails can be estimated as the nail grows out the ridge visibly moves upwards toward the nail edge when the ridge reaches the nail edge the fingertips can become quite sore due to the mis shapen nail pressing into the flesh deeper than usual exposing the sensitive nail bed the quick at the nail edge a researcher found beau s lines in the fingernails of two of six divers following a deep saturation dive to a pressure equal to 305 meters of sea water and in six of six divers following a similar dive to 335 meters they have also been seen in ötzi the ice man
beauty whitewash is a phenomenon in the intersection of fashion industry digital photography mass media marketing and advertising it describes a situation when the skin tone of black or latina women less often of men – when depicted in magazine covers advertisements commercials music videos etc – is digitally retouched to appear whiter probably the most cited and notorious example of beauty whitewashing is a l oreal advertising campaign featuring beyoncé knowles other examples include celebrities halle berry brandy mariah carey rihanna freida pinto jennifer lopez tyra banks leona lewis jennifer hudson gabourey sidibe and queen latifah among others reasons for doing so are believed to be marketing more specifically appealing to the white ethnicity which is generally in most cases the strongest target group for whichever advertisement that is and which creates certain beauty ideal or standard in concert with being on the same wibe with the target audience the extent of beauty whitewash may vary for example the same picture on a magazine cover would have a different extent of brightening the skin tone depending on the country where the magazine is sold beauty whitewash seems to be a part of conforming to those ideals or distorted images thereof – accompanying signs of which could be straightening of otherwise naturally curvy hair or excessive strive to become slender even for naturally thicker body constitution not scarsely resulting to eating disorders beauty whitewash is therefore criticized for distorting the perception of reality exuding a twisted sense of beauty and not lastly having a bad influence on young girls
becker muscular dystrophy is an x linked recessive inherited disorder characterized by slowly progressive muscle weakness of the legs and pelvis it is a type of dystrophinopathy this is caused by mutations in the dystrophin gene which encodes the protein dystrophin becker muscular dystrophy is related to duchenne muscular dystrophy in that both result from a mutation in the dystrophin gene
becker s nevus also known as becker s melanosis becker s pigmentary hamartoma nevoid melanosis and pigmented hairy epidermal nevus is a skin disorder predominantly affecting males the nevus generally first appears as an irregular pigmentation melanosis or hyperpigmentation on the torso or upper arm though other areas of the body can be affected and gradually enlarges irregularly becoming thickened and often hairy hypertrichosis the nevus is due to an overgrowth of the epidermis pigment cells melanocytes and hair follicles this form of nevus was first documented in 1948 by american dermatologist samuel william becker 1894 – 1964
becker s sign or becker s phenomenon is the presence of visible through an ophthalmoscope pulsation of retinal arteries found in patients with aortic insufficiency or graves disease the sign was named after otto heinrich enoch becker
beckwith – wiedemann syndrome ˈbɛkˌwɪθ ˈviːdə mən abbreviated bws is an overgrowth disorder usually present at birth characterized by an increased risk of childhood cancer and certain congenital features beckwith syndrome can also cause child behavior problems common features used to define bws are macroglossia large tongue macrosomia above average birth weight and length midline abdominal wall defects omphalocele exomphalos umbilical hernia diastasis recti ear creases or ear pits neonatal hypoglycemia low blood sugar after birth hepatoblastoma
a bed bug can individually and collectively cause a number of health effects including skin rashes psychological effects and allergic symptoms bed bug bites or cimicosis may lead to a range of skin manifestations from no visible effects to prominent blisters diagnosis involves both finding bed bugs and the occurrence of compatible symptoms treatment involves the elimination of the insect but is otherwise symptomatic because infestation of human habitats has been on the increase in developed countries bed bug bites and related conditions have been on the rise as well since the 1980 s – 1990 s the exact causes of this resurgence remain unclear it is variously ascribed to greater foreign travel more frequent exchange of second hand furnishings among homes a greater focus on control of other pests resulting in neglect of bed bug countermeasures and increasing resistance to pesticides bed bugs have been known human parasites for thousands of years
bednar s aphthae is a type of oral ulceration mouth ulcers which occurs in infants the lesions are located on the palate and are caused by trauma no treatment is required since the lesions heal within a few days the condition was first described in 1850 by the austrian physician alois bednar 1816 1888
a bee sting is a sting from a bee honey bee bumblebee sweat bee etc the stings of most of these species can be quite painful and are therefore keenly avoided by many people bee stings differ from insect bites and the venom or toxin of stinging insects is quite different therefore the body s reaction to a bee sting may differ significantly from one species to another the most aggressive stinging insects are vespid wasps including bald faced hornets and other yellow jackets and hornets especially the asian giant hornet all of these insects aggressively defend their nests in people with insect sting allergy a bee sting may trigger a dangerous anaphylactic reaction that is potentially deadly honey bee stings release pheromones that prompt other nearby bees to attack
beech bark disease is a disease that causes mortality and defects in beech trees in the eastern united states and europe in north america the disease results when the beech scale insect cryptococcus fagisuga attacks the bark creating a wound later two different fungi neonectria faginata previously nectria coccinea var faginata and neonectria ditissima previously nectria galligena common to north america can invade the tree through the wound causing a canker to form in subsequent years new cankers will continue to form ultimately leading to the death of the tree in europe n coccinea is the primary fungus causing the infection infection in european trees occurs in the same manner as it does in north american trees though the disease still appears in europe it is less serious today than it once was
beet vascular necrosis and rot is a soft rot disease caused by the bacterium pectobacterium carotovorum subsp betavasculorum which has also been known as pectobacterium betavasculorum and erwinia carotovora subsp betavasculorum it was classified in the genus erwinia until genetic evidence suggested that it belongs to its own group however the name erwinia is still in use as such the disease is sometimes called erwinia rot today it is a very destructive disease that has been reported across the united states as well as in egypt symptoms include wilting and black streaks on the leaves and petioles it is usually not fatal to the plant but in severe cases the beets will become hollowed and unmarketable the bacteria is a generalist species which rots beets and other plants by secreting digestive enzymes that break down the cell wall and parenchyma tissues the bacteria thrive in warm and wet conditions but cannot survive long in fallow soil however it is able to persist for long periods of time in the rhizosphere of weeds and non host crops while it is difficult to eradicate there are cultural practices that can be used to control the spread of the disease such as avoiding injury to the plants and reducing or eliminating application of nitrogen fertilizer
in software engineering behavioral design patterns are design patterns that identify common communication patterns between objects and realize these patterns by doing so these patterns increase flexibility in carrying out this communication examples of this type of design pattern include chain of responsibility pattern command objects are handled or passed on to other objects by logic containing processing objects command pattern command objects encapsulate an action and its parameters externalize the stack turn a recursive function into an iterative one that uses a stack interpreter pattern implement a specialized computer language to rapidly solve a specific set of problems iterator pattern iterators are used to access the elements of an aggregate object sequentially without exposing its underlying representation mediator pattern provides a unified interface to a set of interfaces in a subsystem memento pattern provides the ability to restore an object to its previous state rollback null object pattern designed to act as a default value of an object observer pattern aka publish subscribe or event listener objects register to observe an event that may be raised by another object weak reference pattern de couple an observer from an observable protocol stack communications are handled by multiple layers which form an encapsulation hierarchy scheduled task pattern a task is scheduled to be performed at a particular interval or clock time used in real time computing single serving visitor pattern optimise the implementation of a visitor that is allocated used only once and then deleted specification pattern recombinable business logic in a boolean fashion state pattern a clean way for an object to partially change its type at runtime strategy pattern algorithms can be selected on the fly template method pattern describes the program skeleton of a program visitor pattern a way to separate an algorithm from an object
behr syndrome is characterized by the association of early onset optic atrophy with spinocerebellar degeneration resulting in ataxia pyramidal signs peripheral neuropathy and developmental delay although it is an autosomal recessive disorder heterozygotes may still manifest much attenuated symptoms autosomal dominant inheritance also being reported in a family recently a variant of opa 1 mutation with phenotypic presentation like behr syndrome is also described some reported cases have been found to carry mutations in the opa 1 opa 3 or c 12 orf 65 genes which are known causes of pure optic atrophy or optic atrophy complicated by movement disorder
in statistics the behrens – fisher problem named after walter ulrich behrens and ronald fisher is the problem of interval estimation and hypothesis testing concerning the difference between the means of two normally distributed populations when the variances of the two populations are not assumed to be equal based on two independent samples
behçet s disease is a rare immune mediated small vessel systemic vasculitis that often presents with mucous membrane ulceration and ocular problems the disease was named in 1937 after the turkish dermatologist hulusi behçet who first described the triple symptom complex of recurrent oral aphthous ulcers genital ulcers and uveitis – a disease of the eye as a systemic disease it can also involve visceral organs such as the gastrointestinal tract pulmonary musculoskeletal cardiovascular and neurological systems this syndrome can be fatal due to ruptured vascular aneurysms or severe neurological complications
belgium competed at the 1900 summer olympics in paris france it was the first appearance of the european nation belgium was represented in france by 78 athletes all of them male who competed in 11 disciplines they comprised 95 entries in 28 events
belgium competed at the 1908 summer olympics in london england it was the second appearance of the european nation which had previously competed at the 1900 summer olympics
bell s palsy is a type of facial paralysis that results in an inability to control the facial muscles on the affected side symptoms can vary from mild to severe they may include muscle twitching weakness or total loss of the ability to move one or rarely both sides of the face other symptoms include drooping of the eyelid a change in taste pain around the ear and increased sensitivity to sound typically symptoms come on over 48 hours the cause of bell s palsy is unknown risk factors include diabetes and a recent upper respiratory tract infection it results from a dysfunction of cranial nerve vii the facial nerve many believe that this is due to a viral infection that results in swelling diagnosis is based on a person s appearance and ruling out other possible causes other conditions that can cause facial weakness include brain tumor stroke ramsay hunt syndrome and lyme disease the condition normally gets better by itself with most achieving normal or near normal function corticosteroids have been found to improve outcomes while antiviral medications may be of a small additional benefit the eye should be protected from drying up with the use of eye drops or an eyepatch surgery is generally not recommended often signs of improvement begin within 14 days with complete recovery within six months a few may not recover completely or have a recurrence of symptoms bell s palsy is the most common cause of one sided facial nerve paralysis 70 it occurs in 1 to 4 per 10 000 people per year about 1 5 of people are affected at some point in their life it most commonly occurs in people between ages 15 and 60 males and females are affected equally it is named after scottish surgeon charles bell 1774 – 1842 who first described the connection of the facial nerve to the condition
a bell pattern is a rhythmic pattern often a key pattern also known as a guide pattern phrasing referent timeline or asymmetrical timeline struck on an idiophone in most cases a metal bell such as an agogô gankoqui or cowbell or a hollowed piece of wood or wooden claves in contemporary music bell patterns are also played on the metal shell of the timbales and drum kit cymbals
a bellman equation named after its discoverer richard bellman also known as a dynamic programming equation is a necessary condition for optimality associated with the mathematical optimization method known as dynamic programming it writes the value of a decision problem at a certain point in time in terms of the payoff from some initial choices and the value of the remaining decision problem that results from those initial choices this breaks a dynamic optimization problem into simpler subproblems as bellman s principle of optimality prescribes the bellman equation was first applied to engineering control theory and to other topics in applied mathematics and subsequently became an important tool in economic theory though the basic concepts of dynamic programming are prefigured in john von neumann and oskar morgenstern s theory of games and economic behavior and abraham wald s sequential analysis almost any problem which can be solved using optimal control theory can also be solved by analyzing the appropriate bellman equation however the term bellman equation usually refers to the dynamic programming equation associated with discrete time optimization problems in continuous time optimization problems the analogous equation is a partial differential equation which is usually called the hamilton – jacobi – bellman equation
the belt of venus or venus s girdle is an atmospheric phenomenon seen at sunrise and sunset shortly after sunset or shortly before sunrise the observer is or is very nearly surrounded by a pinkish glow or anti twilight arch that extends roughly 10 ° – 20 ° above the horizon it is similar to alpenglow as they both are caused by backscattering of reddened sunlight the only difference is that alpenglow is characterized by afterglow and is a red horizontal band visible just after sunset or before sunrise due to direct illumination of clouds and aerosols low in the atmosphere whereas the belt of venus is a rosy pinkish arch visible long after sunset or long before sunrise caused by backscattering of refracted sunlight due to fine dust particles high in the atmosphere in a way the belt of venus is a true alpenglow visible at twilight near the anti solar point often the glow is separated from the horizon by a dark layer the earth s shadow or dark segment the arch s light pink color is due to backscattering of reddened light from the rising or setting sun a very similar effect can be seen during a total solar eclipse the zodiacal light which is caused by reflection of sunlight from the interplanetary dust in the solar system is also a similar phenomenon the name of the phenomenon alludes to the cestus a girdle or breast band of the ancient greek goddess aphrodite customarily equated with the roman goddess venus
the belt problem is a mathematics problem which requires finding the length of a crossed belt that connects two circular pulleys with radius r 1 and r 2 whose centers are separated by a distance p the solution of the belt problem requires trigonometry and the concepts of the bitangent line the vertical angle and congruent angles
ben jacob s bacteria are two pattern forming social bacteria strains the paenibacillus dendritiformis and the paenibacillus vortex discovered in the early 1990 s by eshel ben jacob these bacteria are widely known for their ability to generate large colonies with the number of bacteria exceeding many folds the number of people on earth with highly complex organization
the ben franklin effect is a proposed psychological phenomenon a person who has performed a favor for someone is more likely to do another favor for that person than they would be if they had received a favor from that person an explanation for this would be that we internalize the reason that we helped them was because we liked them the opposite case is also believed to be true namely that we come to hate a person whom we did wrong to we de humanize them to justify the bad things we did to them
the benary reaction is an organic reaction in 1931 erich bénary discovered that β n n dialkylamino vinyl ketones reacted with grignard reagents in a 1 4 addition to give α β unsaturated ketones α β unsaturated aldehydes and α β unsaturated esters as well as poly unsaturated ketones and aldehydes after hydrolysis of the reaction intermediate and elimination of a dialkylated amine mechanism of the benary reaction
a bending moment is the reaction induced in a structural element when an external force or moment is applied to the element causing the element to bend the most common or simplest structural element subjected to bending moments is the beam the example shows a beam which is simply supported at both ends simply supported means that each end of the beam can rotate therefore each end support has no bending moment the ends can only react to the shear load other beams can have both ends fixed therefore each end support has both bending moment and shear reaction loads beams can also have one end fixed and one end simply supported the simplest type of beam is the cantilever which is fixed at one end and is free at the other end neither simple or fixed in reality beam supports are usually neither absolutely fixed nor absolutely rotating freely the internal reaction loads in a cross section of the structural element can be resolved into a resultant force and a resultant couple for equilibrium the moment created by external forces and external moments must be balanced by the couple induced by the internal loads the resultant internal couple is called the bending moment while the resultant internal force is called the shear force if it is transverse to the plane of element or the normal force if it is along the plane of the element the bending moment at a section through a structural element may be defined as the sum of the moments about that section of all external forces acting to one side of that section the forces and moments on either side of the section must be equal in order to counteract each other and maintain a state of equilibrium so the same bending moment will result from summing the moments regardless of which side of the section is selected if clockwise bending moments are taken as negative then a negative bending moment within an element will cause sagging and a positive moment will cause hogging it is therefore clear that a point of zero bending moment within a beam is a point of contraflexure — that is the point of transition from hogging to sagging or vice versa moments and torques are measured as a force multiplied by a distance so they have as unit newton metres n · m or pound foot or foot pound ft · lb the concept of bending moment is very important in engineering particularly in civil and mechanical engineering and physics
benedikt syndrome also called benedikt s syndrome or paramedian midbrain syndrome is a rare type of posterior circulation stroke of the brain with a range of neurological symptoms affecting the midbrain cerebellum and other related structures
benign cephalic histiocytosis also known as histiocytosis with intracytoplasmic worm like bodies and not to be confused with neonatal cephalic pustulosis is a rare cutaneous condition affecting boys and girls equally characterized by skin lesions that initially present on the head in all cases often the cheeks eyelids forehead and ears
benign familial infantile epilepsy bfie also known as benign familial infantile seizures bfis or benign familial infantile convulsions bfic is an epilepsy syndrome affected children who have no other health or developmental problems develop seizures during infancy these seizures have focal origin within the brain but may then spread to become generalised seizures the seizures may occur several times a day often grouped in clusters over one to three days followed by a gap of one to three months treatment with anticonvulsant drugs is not necessary but they are often prescribed and are effective at controlling the seizures this form of epilepsy resolves after one or two years and appears to be completely benign the eeg of these children between seizures is normal the brain appears normal on mri scan a family history of epilepsy in infancy distinguishes this syndrome from the non familial classification see benign infantile epilepsy though the latter may be simply sporadic cases of the same genetic mutations the condition is inherited with an autosomal dominant transmission there are several genes responsible for this syndrome on chromosomes 2 16 and 19 it is generally described as idiopathic meaning that no other neurological condition is associated with it or causes it however there are some forms that are linked to neurological conditions one variant known as infantile convulsions and choreoathetosis icca forms an association between bfie and paroxysmal kinesigenic choreoathetosis and has been linked to the prrt 2 gene on chromosome 16 an association with some forms of familial hemiplegic migraine fhm has also been found benign familial infantile epilepsy is not genetically related to benign familial neonatal epilepsy bfne which occurs in neonates however a variation with seizure onset between two days and seven months called benign familial neonatal – infantile seizures bfnis has been described which is due to a mutation in the scn 2 a gene
benign familial neonatal seizures bfns formerly called benign familial neonatal convulsions bfnc is a rare autosomal dominant inherited form of seizures it manifests in newborns normally within the first 7 days of life as tonic clonic seizures infants are otherwise normal between attacks and develop without incident attacks normally spontaneously cease within the first 15 weeks of life lifetime susceptibility to seizures is increased as 16 of those diagnosed with bfne earlier in life will go on to have seizures versus a 2 lifetime risk for the general population there are three known genetic causes of bfne two being the voltage gated potassium channels kcnq 2 bfnc 1 and kcnq 3 bfnc 2 and the third being a chromosomal inversion bfnc 3 there is no obvious correlation between most of the known mutations and clinical variability seen in bfne
benign fasciculation syndrome bfs is a neurological disorder characterized by fasciculation twitching of various voluntary muscles in the body the twitching can occur in any voluntary muscle group but is most common in the eyelids arms legs and feet even the tongue may be affected the twitching may be occasional or may go on nearly continuously usually intentional movement of the involved muscle causes the fasciculations to cease immediately but they may return once the muscle is at rest again
benign fibrous histiocytomas also known as dermal dendrocytoma dermatofibroma fibrous dermatofibroma fibrous histiocytoma fibroma simplex nodular subepidermal fibrosis and sclerosing hemangioma are benign skin growths
benign hereditary chorea bhc also known as benign familial chorea is a rare autosomal dominant neurogenetic syndrome it typically presents in childhood with isolated chorea unlike other neurogenetic causes of chorea such as huntington s disease bhc is not progressive and not associated with cognitive decline or psychiatric problems in the vast majority of cases bhc is caused by a single nucleotide insertion mutation in titf 1 which encodes thyroid transcription factor 1 ttf 1 this gene is also known as nk 2 homeobox 1 nkx 2 1 in some cases additional developmental abnormalities of lung and thyroid tissue are found in bhc leading to the suggested alternative name brain lung thyroid syndrome
benign hypertension or benign essential hypertension are historical terms that are considered misleading and have fallen out of use see history of hypertension the terminology persists in the international classification of disease icd 9 which dates from the 1970 s but is still used in the usa icd 9 is due to be replaced in usa by icd 10 cm on october 1 2015
benign infantile epilepsy bie also known as benign infantile seizures bis is an epilepsy syndrome of which several forms have been described the international league against epilepsy ilae classify two main forms of the syndrome familial and nonfamilial though several other forms have been described in the academic literature affected children who have no other health or developmental problems develop seizures during infancy these seizures have focal origin within the brain but may then spread to become generalised seizures the seizures may occur several times a day often grouped in clusters over one to three days followed by a gap of one to three months treatment with anticonvulsant drugs is not necessary but they are often prescribed and are effective at controlling the seizures this form of epilepsy resolves after one or two years and appears to be completely benign the eeg of these children between seizures is normal the brain appears normal on mri scan the familial and nonfamilial forms have overlapping features and the presence of a family history of infantile seizures may be the only distinguishing criterion the nonfamiliar form has a larger range of the onset of seizures from three to twenty months with most occurring between five and six months there is no difference between the sexes with benign familial infantile epilepsy the seizures onset from four to eight months of age some cases of nonfamilial benign infantile seizures occur during a case of mild gastroenteritis called benign infantile seizures associated with mild gastroenteritis bis with mg the seizures only occur during this illness and no not recur infection with rotavirus is the most common cause although children with benign infantile epilepsy typically have a normal eeg between seizures some infants have been found to have a characteristic abnormal eeg during sleep called benign infantile focal epilepsy with midline spikes and waves during sleep these infants have few seizures and there may often be a family history
benign lymphoepithelial lesion is a type of benign enlargement of the parotid and or lacrimal glands this pathologic state is sometimes but not always associated with sjögren s syndrome
a benign melanocytic nevus also known as a banal nevus common acquired melanocytic nevus mole nevocellular nevus and nevocytic nevus is a cutaneous condition characterised by well circumscribed round or ovoid lesions generally measuring from 2 to 6 mm in diameter
benign neonatal hemangiomatosis is a cutaneous condition in infants characterized by multiple cutaneous lesions without evident visceral hemangiomas
benign neonatal sleep myoclonus bnsm is the occurrence of myoclonus jerky movements during sleep it is not associated with seizures occurs in the first few weeks of life usually resolves in first 2 – 3 months of life often worries parents because they appear like seizures but they are not features that can help distinguish this condition from seizures include the myoclonic movements only occur during sleep when baby is woken up the myoclonic movements stop normal eeg normal neurological examination normal developmental examination the myoclonic jerks occur during non rem sleep
benign paroxysmal positional vertigo bppv is a disorder arising from a problem in the inner ear symptoms are repeated brief periods of vertigo with movement that is of a spinning sensation caused by changes in the position of the head this can occur with turning in bed or changing position each episode of vertigo typically lasts less than one minute nausea is commonly associated bppv is one of the most common causes of vertigo bppv can result from a head injury or simply occur among those who are older a specific cause is often not found the underlying mechanism involves a small calcified otolith moving around loose in the inner ear it is a type of balance disorder along with labyrinthitis and ménière s disease diagnosis is typically made when the dix hallpike maneuver results in nystagmus a specific movement pattern of the eyes and other possible causes have been ruled out in typical cases medical imaging is not needed bppv is often treated with a number of simple movements such as the epley maneuver or brandt daroff exercises medications may be used to help with nausea there is tentative evidence that betahistine may help with the vertigo but its use is not generally needed bppv is not a serious condition typically it resolves in one to two weeks it however may recur in some people the first medical description of the condition occurred in 1921 by robert barany about 2 4 of people are affected at some point in time among those who live until their 80 s 10 have been affected bbpv affects females twice as often as males onset is typically in the person s 50 s to 70 s
benign paroxysmal torticollis bpt is a rare medical disorder affecting infants
benign paroxysmal vertigo of childhood is an uncommon disorder which presents with recurrent episodes of dizziness the presentation is usually between the ages of 2 years and 7 years of age and is characterised by short episodes of vertigo of sudden onset when the child appears distressed and unwell he or she may cling to something or someone for support the episode lasts only minutes and resolves suddenly and completely it is a self limiting condition and usually resolves after about eighteen months although many go on to experience migrainous vertigo or vertiginous migraine when older benign paroxysmal vertigo of childhood is a migrainous phenomenon with more than 50 of those affected having a family history of migraine affecting a first degree relative it has no relationship to benign paroxysmal positional vertigo which is a different condition entirely
benign prostatic hyperplasia bph also called benign enlargement of the prostate bep or bpe is a noncancerous increase in size of the prostate bph involves hyperplasia of prostatic stromal and epithelial cells resulting in the formation of large fairly discrete nodules in the transition zone of the prostate when sufficiently large the nodules impinge on the urethra and increase resistance to flow of urine from the bladder this is commonly referred to as obstruction although the urethral lumen is no less patent only compressed resistance to urine flow requires the bladder to work harder during voiding possibly leading to progressive hypertrophy instability or weakness atony of the bladder muscle bph involves hyperplasia an increase in the number of cells rather than hypertrophy a growth in the size of individual cells but the two terms are often used interchangeably even among urologists although prostate specific antigen levels may be elevated in these patients because of increased organ volume and inflammation due to urinary tract infections bph does not lead to cancer or increase the risk of cancer adenomatous prostatic growth is believed to begin at approximately age 30 an estimated 50 of men have histologic evidence of bph by age 50 and 75 by age 80 in 40 – 50 of these men bph becomes clinically significant bph was one of the ten most prominent and costly diseases in men older than 50 years of age in a study in the united states
benign symmetric lipomatosis also known as benign symmetric lipomatosis of launois – bensaude madelung s disease multiple symmetric lipomatosis and cephalothoracic lipodystrophy is a cutaneous condition characterized by extensive symmetric fat deposits in the head neck and shoulder girdle area the german surgeon otto wilhelm madelung was the first to give a detailed description of the disorder this condition is very rare with an estimated incidence rate of 1 in 25 000 and affects males up to 30 times more frequently than females the cause of the disease remains unknown but there is a strong correlation with alcohol abuse abstinence from alcohol prevents disease progression defects in the adrenergic stimulated lipolysis and accumulation of embryological brown fat has also been reported cosmetic disfigurement due to the fat deposition in the cervicothoracic region results in a pseudoathletic appearance this resembles the italian statue warrior of capestrano and carvings of queen of punt egypt traditionally the treatment is mainly surgical consisting of the removal of the lipomas although recent study has proposed liposuction and phosphatidylcholine injection as possible alternatives
a benign tumor is a mass of cells tumor that lacks the ability to invade neighboring tissue or metastasize these characteristics are required for a tumor to be defined as cancerous and therefore benign tumors are non cancerous also benign tumors generally have a slower growth rate than malignant tumors and the tumor cells are usually more differentiated cells have normal features benign tumors are typically surrounded by an outer surface fibrous sheath of connective tissue or remain with the epithelium common examples of benign tumors include moles and uterine fibroids although benign tumors will not metastasize or locally invade tissues some types may still produce negative health effects the growth of benign tumors produces a mass effect that can compress tissues and may cause nerve damage reduction of blood to an area of the body ischaemia tissue death necrosis and organ damage the mass effect of tumors are more prominent if the tumor is within an enclosed space such as the cranium respiratory tract sinus or inside bones tumors of endocrine tissues may overproduce certain hormones especially when the cells are well differentiated examples include thyroid adenomas and adrenocortical adenomas although most benign tumors are not life threatening many types of benign tumors have the potential to become cancerous malignant through a process known as tumour progression for this reason and other possible negative health effects some benign tumors are removed by surgery
benjamin syndrome or benjamin anemia is a type of multiple congenital anomaly mental retardation mca mr syndrome it is characterized by hypochromic anemia with mental deficiency and various craniofacial and other anomalies it can also include heart murmur dental caries and splenic tumors it was first described in the medical literature in 1911 symptoms include megalocephaly external ear deformities dental caries micromelia hypoplastic bone deformities hypogonadism hypochromic anemia with occasional tumors and mental retardation
bennett fracture is a fracture of the base of the first metacarpal bone which extends into the carpometacarpal cmc joint this intra articular fracture is the most common type of fracture of the thumb and is nearly always accompanied by some degree of subluxation or frank dislocation of the carpometacarpal joint
bently nevada is a condition monitoring instrumentation company providing services for sensors systems and monitoring machinery vibration the offerings are primarily intended for assessing the mechanical condition of rotating equipment found in machinery intensive industries such as oil and gas production hydrocarbon processing electric power generation pulp paper water and wastewater treatment mining and the like bently was a privately held us corporation between 1961 and 2002 during which time it pioneered the eddy current proximity probe a sensor that revolutionized the measurement of vibration in high speed turbomachinery by allowing the direct observation of the rotating shaft the company also performed significant research in the field of rotordynamics furthering knowledge of machinery malfunctions such as shaft cracks and fluid induced instabilities its research also helped refine the equations used to describe vibratory behavior in rotordynamic systems the company was acquired by ge energy in february 2002 and continues to design manufacture and market these products and services using the bently nevada name
the benzilic acid rearrangement is the rearrangement reaction of benzil with potassium hydroxide to benzilic acid first performed by justus liebig in 1838 this reaction type is displayed by 1 2 diketones in general the reaction product is an α hydroxy – carboxylic acid scheme 1 benzilic acid rearrangement certain acyloins also rearrange in this fashion this diketone reaction is related to other rearrangements the corresponding keto aldehyde one alkyl group replaced by hydrogen rearranges in a cannizzaro reaction the corresponding 1 2 diol reacts in a pinacol rearrangement
benzodiazepine dependence or benzodiazepine addiction is when one has developed one or more of either tolerance withdrawal symptoms drug seeking behaviors such as continued use despite harmful effects and maladaptive pattern of substance use according to the dsm iv in the case of benzodiazepine dependence however the continued use seems to be associated with the avoidance of unpleasant withdrawal reaction rather than from the pleasurable effects of the drug benzodiazepine dependence develops with long term use even at low therapeutic doses without the described dependence behavior addiction or what is sometimes referred to as psychological dependence includes people misusing or craving the drug not to relieve withdrawal symptoms but to experience its euphoric or intoxicating effects it is important to distinguish between addiction and drug abuse of benzodiazepines and normal physical dependence on benzodiazepines the increased gabaa inhibition caused by benzodiazepines is counteracted by the body s development of tolerance to the drug s effects the development of tolerance occurs as a result of neuroadaptations which result in decreased gaba inhibition and increased excitability of the glutamate system these adaptations occur as a result of the body trying to overcome the central nervous system depressant effects of the drug to restore homeostasis when benzodiazepines are stopped these neuroadaptations are unmasked leading to hyper excitability of the nervous system and the appearance of withdrawal symptoms therapeutic dose dependence is the largest category of people dependent on benzodiazepines these individuals typically do not escalate their doses to high levels or abuse their medication smaller groups include patients escalating their dosage to higher levels and drug misusers as well it is unclear exactly how many people illicitly abuse benzodiazepines tolerance develops within days or weeks to the anticonvulsant hypnotic muscle relaxant and after 4 months there is little evidence that benzodiazepines retain their anxiolytic properties some authors however disagree and feel that benzodiazepines retain their anxiolytic properties long term benzodiazepine treatment may remain necessary in certain clinical conditions dependence and misuse of benzodiazepines have been of concern since 2002 based on findings in the us from the treatment episode data set teds an annual compilation of patient characteristics in substance abuse treatment facilities in the united states admissions due to primary tranquilizer including but not limited to benzodiazepine type drug use increased 79 from 1992 to 2002 thus the dawn and teds data sets demonstrate clearly that the misuse of these sedative hypnotics is on the rise and cause for concern numbers of benzodiazepine prescriptions have been declining due primarily to concerns of dependence in the short term benzodiazepines can be effective drugs for acute anxiety or insomnia with longer term use other therapies both pharmacological and psychotherapeutic become more effective this is in part due to the greater effectiveness over time of other forms of therapy and also due to the eventual development of pharmacological benzodiazepine tolerance
benzodiazepine overdose describes the ingestion of one of the drugs in the benzodiazepine class in quantities greater than are recommended or generally practiced death as a result of taking an excessive dose of benzodiazepines alone is uncommon versus combined drug intoxication but does occasionally happen deaths after hospital admission are considered to be low however combinations of high doses of benzodiazepines with alcohol barbiturates opioids or tricyclic antidepressants are particularly dangerous and may lead to severe complications such as coma or death the most common symptoms of overdose include central nervous system cns depression and intoxication with impaired balance ataxia and slurred speech severe symptoms include coma and respiratory depression supportive care is the mainstay of treatment of benzodiazepine overdose there is an antidote flumazenil but its use is controversial as benzodiazepines are one of the most highly prescribed classes of drugs they are commonly used in self poisoning by drug overdose the various benzodiazepines differ in their toxicity since they produce varying levels of sedation in overdose a 1993 british study of deaths during the 1980 s found flurazepam and temazepam more frequently involved in drug related deaths causing more deaths per million prescriptions than other benzodiazepines flurazepam now rarely prescribed in the united kingdom and australia had the highest fatal toxicity index of any benzodiazepine 15 0 followed by temazepam 11 9 versus benzodiazepines overall 5 9 taken with or without alcohol an australian 1995 study found oxazepam less toxic and less sedative and temazepam more toxic and more sedative than most benzodiazepines in overdose an australian study 2004 of overdose admissions between 1987 and 2002 found alprazolam which happens to be the most prescribed benzodiazepine in the u s by a large margin to be more toxic than diazepam and other benzodiazepines they also cited a review of the annual reports of the american association of poison control centers national data collection system which showed alprazolam was involved in 34 fatal deliberate self poisonings over 10 years 1992 – 2001 compared with 30 fatal deliberate self poisonings involving diazepam in a new zealand study 2003 of 200 deaths zopiclone a benzodiazepine receptor agonist had similar overdose potential as benzodiazepines
benzodiazepine use disorder also called misuse or abuse is the use of benzodiazepines without a prescription often for recreational purposes which poses risks of dependence withdrawal and other long term effects benzodiazepines are one of the more common prescription drugs used recreationally when used recreationally benzodiazepines are usually administered orally but sometimes they are taken intranasally or intravenously recreational use produces effects similar to alcohol intoxication in tests in pentobarbital trained rhesus monkeys benzodiazepines produced effects similar to barbiturates in a 1991 study triazolam had the highest self administration rate in cocaine trained baboons among the five benzodiazepines examined alprazolam bromazepam chlordiazepoxide lorazepam triazolam a 1985 study found that triazolam and temazepam maintained higher rates of self injection than a variety of other benzodiazepines a 1991 study indicated that diazepam in particular had a greater abuse liability among people who were drug abusers than did many of the other benzodiazepines some of the available data also suggested that lorazepam and alprazolam are more diazepam like in having relatively high abuse liability while oxazepam halazepam and possibly chlordiazepoxide are relatively low in this regard a 1991 – 1993 british study found that the hypnotics flurazepam and temazepam were more toxic than average benzodiazepines in overdose a 1995 study found that temazepam is more rapidly absorbed and oxazepam is more slowly absorbed than most other benzodiazepines benzodiazepines have been abused both orally and intravenously different benzodiazepines have different abuse potential the more rapid the increase in the plasma level following ingestion the greater the intoxicating effect and the more open to abuse the drug becomes the speed of onset of action of a particular benzodiazepine correlates well with the ‘ popularity ’ of that drug for abuse the two most common reasons for preference were that a benzodiazepine was ‘ strong ’ and that it gave a good ‘ high ’ according to dr chris ford former clinical director of substance misuse management in general practice among drugs of abuse benzodiazepines are often seen as the bad guys by drug and alcohol workers illicit users of benzodiazepines have been found to take higher methadone doses as well as showing more hiv hcv risk taking behaviour greater poly drug use higher levels of psychopathology and social dysfunction however there is only limited research into the adverse effects of benzodiazepines in drug misusers and further research is needed to demonstrate whether this is the result of cause or effect
benzodiazepine withdrawal syndrome — often abbreviated to benzo withdrawal — is the cluster of symptoms that emerge when a person who has taken benzodiazepines either medically or recreationally and has developed a physical dependence undergoes dosage reduction or discontinuation development of physical dependence and or addiction and the resulting withdrawal symptoms some of which may last for years may result from either drug seeking behaviors or from taking the medication as prescribed benzodiazepine withdrawal is characterized by sleep disturbance irritability increased tension and anxiety panic attacks hand tremor sweating difficulty with concentration confusion and cognitive difficulty memory problems dry retching and nausea weight loss palpitations headache muscular pain and stiffness a host of perceptual changes hallucinations seizures psychosis and suicide see signs and symptoms section below for full list further these symptoms are notable for the manner in which they wax and wane and vary in severity from day to day or week by week instead of steadily decreasing in a straightforward monotonic manner it is a potentially serious condition and is complex and often protracted in time course long term use defined as daily use for at least three months is not desirable because of the associated increased risk of dependence dose escalation loss of efficacy increased risk of accidents and falls particularly for the elderly as well as cognitive neurological and intellectual impairments use of short acting hypnotics while being effective at initiating sleep worsen the second half of sleep due to withdrawal effects nevertheless long term users of benzodiazepines should not be forced to withdraw against their will benzodiazepine withdrawal can be severe and can provoke life threatening withdrawal symptoms such as seizures particularly with abrupt or overly rapid dosage reduction from high doses or long time users a severe withdrawal response can nevertheless occur despite gradual dose reduction or from relatively low doses in short time users even after a single large dose in animal models a minority of individuals will experience a protracted withdrawal syndrome whose symptoms may persist at a sub acute level for months or years after cessation of benzodiazepines the likelihood of developing a protracted withdrawal syndrome can be minimized by a slow gradual reduction in dosage chronic exposure to benzodiazepines causes neural adaptations that counteract the drug s effects leading to tolerance and dependence despite taking a constant therapeutic dose long term use of benzodiazepines may lead to the emergence of withdrawal like symptoms particularly between doses when the drug is discontinued or the dosage reduced withdrawal symptoms may appear and remain until the body reverses the physiological adaptations these rebound symptoms may be identical to the symptoms for which the drug was initially taken or may be part of discontinuation symptoms in severe cases the withdrawal reaction may exacerbate or resemble serious psychiatric and medical conditions such as mania schizophrenia and especially at high doses seizure disorders failure to recognize discontinuation symptoms can lead to false evidence for the need to take benzodiazepines which in turn leads to withdrawal failure and reinstatement of benzodiazepines often to higher doses awareness of the withdrawal reactions individualized taper strategies according to withdrawal severity the addition of alternative strategies such as reassurance and referral to benzodiazepine withdrawal support groups all increase the success rate of withdrawal
the benzoin condensation is a reaction often called a condensation reaction for historical reasons between two aromatic aldehydes particularly benzaldehyde the reaction is catalyzed by a nucleophile such as the cyanide anion or an n heterocyclic carbene the reaction product is an aromatic acyloin with benzoin as the parent compound an early version of the reaction was developed in 1832 by justus von liebig and friedrich woehler during their research on bitter almond oil the catalytic version of the reaction was developed by nikolay zinin in the late 1830 s and the reaction mechanism for this organic reaction was proposed in 1903 by a j lapworth
benzylpenicillin inn aan ban also known as penicillin g usan is a narrow spectrum penicillin antibiotic that is given intravenously or intramuscularly as a treatment for syphilis meningitis endocarditis pneumonia lung abscesses and septicaemia in children penicillin g is typically given by injection parenterally bypassing the intestines because it is unstable in the highly acidic stomach because the drug is given parenterally higher tissue concentrations of penicillin g can be achieved than is possible with phenoxymethylpenicillin these higher concentrations translate to increased antibacterial activity it is on the world health organization s list of essential medicines a list of the most important medications needed in a basic health system
berdon syndrome also called megacystis microcolon intestinal hypoperistalsis syndrome mmih syndrome is an autosomal recessive fatal genetic disorder affecting newborns in a 2011 study of 227 children with the syndrome the oldest survivor was 24 years old the ann arbor news reported a five year old survivor at the end of 2015 it is more prevalent in females 7 females to 3 males and is characterized by constipation and urinary retention microcolon giant bladder megacystis intestinal hypoperistalis hydronephrosis and dilated small bowel the pathological findings consist of an abundance of ganglion cells in both dilated and narrow areas of the intestine it is a familial disturbance of unknown aetiology walter berdon et al in 1976 first described the condition in five female infants two of whom were sisters all had marked dilatation of the bladder and some had hydronephrosis and the external appearance of prune belly the infants also had microcolon and dilated small intestines
the bergman cyclization or bergman reaction or bergman cycloaromatization is an organic reaction and more specifically a rearrangement reaction taking place when an enediyne is heated in presence of a suitable hydrogen donor scheme 1 it is the most famous and well studied member of the general class of cycloaromatization reactions it is named for the american chemist robert george bergman b 1942 the reaction product is a derivative of benzene scheme 1 bergman cyclization the reaction proceeds by a thermal reaction or pyrolysis above 200 ° c forming a short lived and very reactive para benzyne biradical species it will react with any hydrogen donor such as 1 4 cyclohexadiene which converts to benzene when quenched by tetrachloromethane the reaction product is a 1 4 dichlorobenzene and with methanol the reaction product is benzyl alcohol when the enyne moiety is incorporated into a 10 membered hydrocarbon ring e g cyclodeca 3 ene 1 5 diyne in scheme 2 the reaction taking advantage of increased ring strain in the reactant is possible at the much lower temperature of 37 ° c scheme 2 bergman reaction of cyclodeca 3 ene 1 5 diyne naturally occurring compounds such as calicheamicin contain the same 10 membered ring and are found to be cytotoxic these compounds generate the diradical intermediate described above which can cause single and double stranded dna cuts there are novel drugs which attempt to make use of this property including monoclonal antibodies such as mylotarg a biradical mechanism is also proposed for the formation of certain biomolecules found in marine sporolides that have a chlorobenzene unit as part of their structure in this mechanism a halide salt provides the halogen a model reaction with the enediyene cyclodeca 1 5 diyn 3 ene lithium bromide as halogen source and acetic acid as hydrogen source in dmso at 37 ° c supports the theory bergman cyclization with capture by lithium bromide the reaction is found to be first order in enediyne with the formation of p benzyne a as the rate limiting step the halide ion then donates its two electrons in the formation of a new br c bond and radical electron involved is believed to shuttle over a transient c 1 c 4 bond forming the anion intermediate b the anion is a powerful base stripping protons even from dmso to final product the dibromide or dihydrogen product tetralin never form as reported in nature chemistry scientists from ibm research and ciqus at the university of santiago de compostela demonstrated a reversible bergman cyclisation for the first time using an atomic force microscope when learning about the demonstration bergman commented when we first reported this reaction i had no idea that it would be biologically relevant or that the reaction could someday be visualized at the molecular level
bergmann gliosis is hyperplasia of bergmann glia in the cerebellum due to purkinje cell death as may occur in a hypoxic ischemic insult or peritumoral compression
beriberi refers to a cluster of symptoms caused primarily by thiamine vitamin b 1 deficiency beriberi has conventionally been divided into three separate entities relating to the body system mainly involved peripheral nervous system or cardiovascular or age of person like infantile beriberi is one of several thiamine deficiency related conditions which may occur concurrently including wernicke s encephalopathy mainly affecting the central nervous system korsakoff s syndrome amnesia with additional psychiatric manifestations and wernicke korsakoff syndrome with both neurologic and psychiatric symptoms historically beriberi has been common in regions where what is variously referred to as polished or white rice forms a major part of the diet which has its husk removed to extend its shelf life and palatability but has the side effect of removing the primary source of thiamine it was not known until the end of the 19 th century that polishing rice was associated with beriberi
berk – tabatznik syndrome is a condition with an unknown cause that shows symptoms of short stature congenital optic atrophy and brachytelephalangy this condition is extremely rare with only two cases being found
berlin s edema commotio retinae is a common condition caused by blunt injury to the eye it is characterized by decreased vision in the injured eye a few hours after the injury under examination the retina appears opaque and white in colour in the periphery but the blood vessels are normally seen this whitening is indicative of cell damage which occurs in the retinal pigment epithelium and outer segment layer of photoreceptors damage to the outer segment often results in photoreceptor death through uncertain mechanisms usually there is no leakage of fluid and therefore it is not considered a true edema the choroidal fluorescence in fluorescent angiography is absent visual acuity ranges from 20 20 to 20 400 the prognosis is excellent except in case of complications of choroidal rupture hemorrhage or pigment epithelial damage but damage to the macula will result in poorer recovery the outcome can be worsened in the case of retinal detachment atrophy or hyperplasia visual field defects can occur in late cases cystoid macular edema sometimes develops which can further lead to macular destruction commotio retinae is usually self limiting and there is no treatment as such it usually resolves in 3 4 weeks without any complications and sequelae
bernard – soulier syndrome bss also called hemorrhagiparous thrombocytic dystrophy is a rare autosomal recessive coagulopathy bleeding disorder that causes a deficiency of glycoprotein ib gpib the receptor for von willebrand factorthe incidence of bss is estimated to be less than 1 case per million persons based on cases reported from europe north america and japan bss is a giant platelet disorder meaning that it is characterized by abnormally large platelets
the bernthsen acridine synthesis is the chemical reaction of a diarylamine heated with a carboxylic acid or acid anhydride and zinc chloride to form a 9 substituted acridine the bernthsen acridine synthesis using zinc chloride one must heat the reaction to 200 270 ° c for 24 hrs the use of polyphosphoric acid will give acridine products at a lower temperature but also with decreased yields
berserk llama syndrome or berserk male syndrome as it is more pronounced in males is a psychological condition suffered by human raised llamas and alpacas that can cause them to exhibit dangerously aggressive behavior toward humans the term has been overused however and is sometimes inappropriately applied to llamas with aggressive personalities that are not truly berserk the condition is a result of the llama imprinting on its human handlers to such a degree that it considers them to be fellow llamas imprinting can be caused by bottle feeding and by isolation from other llamas adult male inter llama interaction can be rough including chest ramming and biting and they are strongly territorial male llamas suffering from this condition become dangerous when this behavior is directed toward humans and they usually have to be euthanised female llamas can also suffer from berserk llama syndrome but their behavior is usually limited to spitting and difficult handling berserk llama syndrome can be prevented in males through castration before puberty
the berth allocation problem also known as the berth scheduling problem is a np complete problem in operations research regarding the allocation of berth space for vessels in container terminals vessels arrive over time and the terminal operator needs to assign them to berths to be served loading and unloading containers as soon as possible different factors affect the berth and time assignment of each vessel among models found in the literature there are four most frequently observed cases 1 a discrete vs continuous berthing space 2 b static vs dynamic vessel arrivals 3 c static vs dynamic vessel handling times and 4 d variable vessel arrivals in the discrete problem the quay is viewed as a finite set of berths in the continuous problem vessels can berth anywhere along the quay and the majority of research deals with the former case in the static arrival problem all vessels are already at the port whereas in the dynamic only a portion of the vessels to be scheduled are present the majority of the published research in berth scheduling considers the latter case in the static handling time problem vessel handling times are considered as input whereas in the dynamic they are decision variables finally in the last case the vessel arrival times are considered as variables and are optimized technical restrictions such as berthing draft and inter vessel and end berth clearance distance are further assumptions that have been adopted in some of the studies dealing with the berth allocation problem bringing the problem formulation closer to real world conditions introducing technical restrictions to existing berth allocation models is rather straightforward and it may increase the complexity of the problem but simplify the use of metaheuristics decrease in the feasible space some of the most notable objectives addressed in the literature are 1 minimization of vessel total service times waiting and handling times 2 minimization of early and delayed departures 3 optimization of vessel arrival times 4 optimization of emissions and fuel consumption problems have been formulated as single and multi objective as well as single and bi level
bertielliasis is the infection of bertiella a cestode tapeworm parasite that primarily infects nonhuman primates rodents and australian marsupials occasionally human infections have been documented by one of two species bertiella studeri or bertiella mucronata these infections present with symptoms similar to most tapeworm cases and are frequently misdiagnosed bertiella transmission is through oribatid mites that are present in the soil of problem areas and can be easily prevented by avoiding contact with nonhuman primates rodents and soil in these areas
the bertrand paradox is a problem within the classical interpretation of probability theory joseph bertrand introduced it in his work calcul des probabilités 1889 as an example to show that probabilities may not be well defined if the mechanism or method that produces the random variable is not clearly defined
berylliosis or chronic beryllium disease cbd is a chronic allergic type lung response and chronic lung disease caused by exposure to beryllium and its compounds a form of beryllium poisoning it is distinct from acute beryllium poisoning which became rare following occupational exposure limits established around 1950 berylliosis is an occupational lung disease the condition is incurable but symptoms can be treated
beryllium granulomas is a skin condition caused by granulomatous inflammation of the skin which may follow accident laceration usually in the occupational setting
β hydride elimination is a reaction in which an alkyl group bonded to a metal centre is converted into the corresponding metal bonded hydride and an alkene the alkyl must have hydrogens on the β carbon for instance butyl groups can undergo this reaction but methyl groups cannot the metal complex must have an empty or vacant site cis to the alkyl group for this reaction to occur the β hydride elimination can either be a vital step in a reaction or an unproductive side reaction the shell higher olefin process relies on β hydride elimination to produce α olefins which are used to produce detergents illustrative of a sometimes undesirable β hydride elimination β hydride elimination in ziegler – natta polymerization results in polymers of decreased molecular weight in the case of nickel and palladium catalyzed couplings of aryl halides with alkyl grignard reagents the β hydride elimination can lower the yield the production of branched polymers from ethylene relies on chain walking a key step of which is β hydride elimination in some cases β hydride elimination is the first in a series of steps for instance in the synthesis of ruhcl co pph 3 3 from ruthenium trichloride triphenylphosphine and 2 methoxyethanol an intermediate alkoxide complex undergoes a β hydride elimination to form the hydride ligand and the pi bonded aldehyde which then is later converted into the carbonyl carbon monoxide ligand
beta ketothiolase deficiency is a rare autosomal recessive metabolic disorder in which the body cannot properly process the amino acid isoleucine or the products of lipid breakdown the typical age of onset for this disorder is between 6 months and 24 months
beta mannosidosis also called lysosomal beta mannosidase deficiency is a disorder of oligosaccharide metabolism caused by decreased activity of the enzyme beta mannosidase this enzyme is coded for by the gene manba located at 4 q 22 25 beta mannosidosis is inherited in an autosomal recessive manner affected individuals appear normal at birth and can have a variable clinical presentation infantile onset forms show severe neurodegeneration while some children have intellectual disability hearing loss and angiokeratomas are common features of the disease however because it is so rare the full phenotype associated with the disease is not fully understood beta mannosidosis was identified as a neurodegenerative disorder in goats in 1981 five years before the first case was described in a human patient the initial patient described in 1986 had a complex phenotype and was later found to have both beta mannosidosis and sanfilippo syndrome patients have been described with a wide spectrum of clinical presentations from infants and children with intellectual disability to adults who present with isolated skin findings angiokeratomas most cases are identified in the first year of life with respiratory infections hearing loss and intellectual disability affected patients with beta mannosidosis differ from those affected with other lysosomal storage disorders in the absence of coarse facies organomegaly and dysostosis multiplex because of its rarity and non specific clinical findings beta mannosidosis can go undiagnosed until adulthood where it can present with intellectual disability and behavioral problems including aggression a diagnosis of beta mannosidosis is suspected based on the patients clinical presentation urine testing to identify abnormal oligosaccharides is a useful screening test and enzymatic analysis or molecular testing can be used for confirmation currently there is no treatment for individuals affected with beta mannosidosis
beta dispersion is the phenomenon associated with the ability of a biological cell membrane to filter out low frequency currents and allow high frequency currents to pass through it was originally hypothesized by rudolf höber in 1910
beta scission is an important reaction in the chemistry of thermal cracking of hydrocarbons and the formation of free radicals free radicals are formed upon splitting the carbon carbon bond free radicals are extremely reactive and short lived when a free radical in a polymer chain undergoes a beta scission the free radical breaks two carbons away from the charged carbon producing an olefin ethylene and a primary free radical which has two fewer carbon atoms in organic synthesis beta scission can be used to direct multistep radical transformations for example beta scission of a weak c s bond was used to favor one of two equilibrating radicals in metal free conversion of phenols to aromatic esters and acids via c o transposition
beta thalassemias β thalassemias are a group of inherited blood disorders they are forms of thalassemia caused by reduced or absent synthesis of the beta chains of hemoglobin that result in variable outcomes ranging from severe anemia to clinically asymptomatic individuals global annual incidence is estimated at 1 in 100 000 beta thalassemias are caused by mutations in the hbb gene on chromosome 11 inherited in an autosomal recessive fashion the severity of the disease depends on the nature of the mutation hbb blockage over time leads to decreased beta chain synthesis the body s inability to construct new beta chains leads to the underproduction of hba reductions in hba available overall to fill the red blood cells in turn leads to microcytic anemia microcytic anemia ultimately develops in respect to inadequate hbb for sufficient red blood cell functioning due to this factor the patient may require blood transfusions to make up for the blockage in the beta chains repeated blood transfusions can lead to build up of iron overload ultimately resulting in iron toxicity this iron toxicity can cause various problems including myocardial siderosis and heart failure leading to the patient ’ s death
bethlem myopathy is an autosomal dominant myopathy classified as a congenital form of muscular dystrophy that is caused by a mutation in one of the three genes coding for type vi collagen these include col 6 a 1 col 6 a 2 and col 6 a 3
the betti reaction is a chemical addition reaction of aldehydes primary aromatic amines and phenols producing α aminobenzylphenols overview of the betti reaction the betti reaction is a special case of the mannich reaction
betweenness is an algorithmic problem in order theory about ordering a collection of items subject to constraints that some items must be placed between others it has applications in bioinformatics but was shown to be np complete by
a bezoar ˈbiːzɔər is a mass found trapped in the gastrointestinal system though it can occur in other locations a pseudobezoar is an indigestible object introduced intentionally into the digestive system there are several varieties of bezoar some of which have inorganic constituents and others organic the term has both a modern medical scientific and a traditional usage
bezold s abscess is an abscess in the sternocleidomastoid muscle where pus from a mastoiditis escapes into the sternocleidomastoid it is a rare complication of acute otitis media
bhaskar – jagannathan syndrome is an extremely rare genetic disorder and there is a limited amount of information related to it similar or related medical conditions are arachnodactyly aminoaciduria congenital cataracts cerebellar ataxia and delayed developmental milestones
bi curious is a phenomenon in which people of a heterosexual or homosexual identity who while showing some curiosity for a relationship or sexual activity with a person of the sex they do not favor distinguish themselves from the bisexual label the term is sometimes used to describe a broad continuum of sexual orientation between heterosexuality and bisexuality such continuums include mostly heterosexual or mostly homosexual but these can be self identified without identifying as bisexual the terms heteroflexible and homoflexible are also applied to bi curiosity though some authors distinguish heteroflexibility as lacking the wish to experiment with sexuality implied by the bi curious label the term bi curious implies that the individual has either no or limited homosexual experience in the case of heterosexual individuals or no or limited heterosexual experience in the case of homosexual people but may continue to self identify as bi curious if they do not feel they have adequately explored these feelings or if they do not wish to identify as bisexual
in statistics the bias or bias function of an estimator is the difference between this estimator s expected value and the true value of the parameter being estimated an estimator or decision rule with zero bias is called unbiased otherwise the estimator is said to be biased in statistics bias is an objective statement about a function and while not a desired property it is not pejorative unlike the ordinary english use of the term bias bias can also be measured with respect to the median rather than the mean expected value in which case one distinguishes median unbiased from the usual mean unbiasedness property bias is related to consistency in that consistent estimators are convergent and asymptotically unbiased hence converge to the correct value though individual estimators in a consistent sequence may be biased so long as the bias converges to zero see bias versus consistency all else equal an unbiased estimator is preferable to a biased estimator but in practice all else is not equal and biased estimators are frequently used generally with small bias when a biased estimator is used the bias is also estimated a biased estimator may be used for various reasons because an unbiased estimator does not exist without further assumptions about a population or is difficult to compute as in unbiased estimation of standard deviation because an estimator is median unbiased but not mean unbiased or the reverse because a biased estimator reduces some loss function particularly mean squared error compared with unbiased estimators notably in shrinkage estimators or because in some cases being unbiased is too strong a condition and the only unbiased estimators are not useful further mean unbiasedness is not preserved under non linear transformations though median unbiasedness is see for example the sample variance is an unbiased estimator for the population variance but its square root the sample standard deviation is a biased estimator for the population standard deviation these are all illustrated below
in statistics and machine learning the bias – variance tradeoff or dilemma is the problem of simultaneously minimizing two sources of error that prevent supervised learning algorithms from generalizing beyond their training set the bias is error from erroneous assumptions in the learning algorithm high bias can cause an algorithm to miss the relevant relations between features and target outputs underfitting the variance is error from sensitivity to small fluctuations in the training set high variance can cause overfitting modeling the random noise in the training data rather than the intended outputs the bias – variance decomposition is a way of analyzing a learning algorithm s expected generalization error with respect to a particular problem as a sum of three terms the bias variance and a quantity called the irreducible error resulting from noise in the problem itself this tradeoff applies to all forms of supervised learning classification regression function fitting and structured output learning it has also been invoked to explain the effectiveness of heuristics in human learning
bicipital tenosynovitis is tendinitis or inflammation of the tendon and sheath lining of the biceps muscle it is often the result of many years of small tears or other degenerative changes in the tendon first manifesting in middle age but can be due to a sudden injury calcification of the tendon and osteophytes bone spurs in the intertubercular groove can be apparent on x rays the condition which can also occur in dogs is commonly treated with physical therapy and cortisone and or surgery
bickerstaff s encephalitis is a rare inflammatory disorder of the central nervous system first described by edwin bickerstaff in 1951 it may also affect the peripheral nervous system and has features in common with both miller fisher syndrome and guillain – barré syndrome
a bicornuate uterus or bicornate uterus from the latin cornū meaning horn commonly referred to as a heart shaped uterus is a uterus composed of two horns separated by a septum in humans a bicornuate uterus is a type of uterine malformation but in some other mammalian species including rodents and pigs it is normal
bicultural identity is the condition of being oneself regarding the combination of two cultures the term can also be defined as biculturalism which is the presence of two different cultures in the same country or region as a general term culture involves the behaviors and belief characteristics of a particular social ethnic or age group within culture we have cultural effects which are the shared behaviors and customs we learn from the institutions around us an example of a cultural effect would be how an individual ’ s personality is strongly influenced by the biological and social norms he is exposed to another cultural effect would be that in some societies it would be more acceptable to dress or act in a certain way in regards to bicultural identity an individual may face conflict assimilating into both cultures or finding a balance between both an individual may face challenges assimilating into the whole collective culture similarly an individual may face difficulty balancing their identity within themselves due to the influence of both of their cultures bicultural identity also may have positive effects on the individual in terms of the additional knowledge they acquire from belonging to more than one culture furthermore with the growing number of racial minorities in american society individuals that identify with more than one culture may have more linguistic ability
a bicuspid aortic valve bav is a disease usually congenital in nature of the aortic valve in which two of the aortic valvular leaflets fuse during development resulting in a valve that is bicuspid instead of the normal tricuspid configuration normally the mitral valve bicuspid valve is the only cardiac valve that is bicuspid and this is situated between the left atrium and left ventricle cardiac valves play a crucial role in ensuring the unidirectional flow of blood from the atrium to the ventricles or from the ventricle to the aorta or pulmonary trunk
bidirectional texture function btf is a 6 dimensional function depending on planar texture coordinates x y as well as on view and illumination spherical angles in practice this function is obtained as a set of several thousand color images of material sample taken during different camera and light positions the btf is a representation of the appearance of texture as a function of viewing and illumination direction it is an image based representation since the geometry of the surface is unknown and not measured btf is typically captured by imaging the surface at a sampling of the hemisphere of possible viewing and illumination directions btf measurements are collections of images the term btf was first introduced in and similar terms have since been introduced including bssrdf and sbrdf spatial brdf sbrdf has a very similar definition to btf i e btf is also a spatially varying brdf to cope with a massive btf data with high redundancy many compression methods were proposed application of the btf is in photorealistic material rendering of objects in virtual reality systems and for visual scene analysis e g recognition of complex real world materials using bidirectional feature histograms or 3 d textons biomedical and biometric applications of the btf include recognition of skin texture
the bid – offer spread also bid – ask bid ask buy sell buy – sell in the case of a market maker is the difference between the prices quoted either by a single market maker or in a limit order book for an immediate sale bid and an immediate purchase offer for securities stocks futures contracts options or currency pairs the size of the bid offer spread in a security is one measure of the liquidity of the market and of the size of the transaction cost if the spread is 0 then it is a frictionless asset
the biefeld – brown effect is an electrical effect that produces an ionic wind that transfers its momentum to surrounding neutral particles the effect was named by inventor thomas townsend brown who claimed that he did a series of experiments with professor of astronomy paul alfred biefeld a former teacher of brown who brown claimed was his mentor and co experimenter at denison university in ohio the phenomenon was also given the name electrogravitics by brown based on his belief this was an electricity gravity phenomenon the effect is more widely referred to as electrohydrodynamics ehd or sometimes electro fluid dynamics a counterpart to the well known magnetohydrodynamics extensive research was performed during the 1950 s and 1960 s on the use of this electric propulsion effect during the publicized era of the united states gravity control propulsion research 1955 – 1974 there is renewed focus on the biefield – brown effect with the spread in interest in high voltage powered experimental flying devices known as ionocraft or lifters
bienfang s test is a clinical test used in the diagnosis of ocular myasthenia gravis it is used in conjunction with other examination techniques such as cogan ’ s lid twitch test or enhancement of blepharoptosis from prolonged upward gaze it is a simple quick and non invasive test for ocular myasthenia gravis that can be performed not only by ophthalmologists or neurologists but also by other physicians evaluating patients with ptosis diplopia or other symptoms of myasthenia gravis
bier spots are small light macules usually found on the arms and legs of young adults in which the intervening skin may seem erthematous but blanches with pressure so that these light macules disappear this is a benign physiologic vascular anomaly of no significance clinically
bietti s crystalline dystrophy bcd also called bietti crystalline corneoretinal dystrophy is a rare autosomal recessive eye disease named after dr g b bietti bcd is a rare disease and appears to be more common in people with asian ancestry
bifascicular block is a conduction abnormality in the heart where two of the three main fascicles of the his purkinje system are blocked most commonly it refers to a combination of right bundle branch block rbbb and either left anterior fascicular block lafb or left posterior fascicular block lpfb with the former being more common some authors consider left bundle branch block lbbb to be a technical bifascicular block since the block occurs above the bifurcation of the left anterior and left posterior fascicles of the left bundle branch
a bifid penis or double penis is a rare congenital defect where two genital tubercles develop historically males born with a bifid penis often underwent sex reassignment surgery due to the difficulty of penile reconstruction they were raised as girls and often had reconstructive surgery to make them phenotypically female coupled with female hormone replacement therapy however in recent years this practice has fallen under heavy scrutiny due to both a high frequency of sexual dysfunction in gender converted children and more advanced penile reconstruction techniques many male marsupials naturally have a bifid penis with left and right prongs that they insert into multiple vaginal canals simultaneously
a bifid rib bifurcated rib or sternum bifidum is a congenital abnormality of the rib cage and associated muscles and nerves which occurs in about 1 2 of humans bifid ribs occur in up to 8 4 of samoans the sternal end of the rib is cleaved into two it is usually unilateral bifid ribs are usually asymptomatic and are often discovered incidentally by chest x ray effects of this neuroskeletal anomaly can include respiratory difficulties neurological difficulties limitations and limited energy from the stress of needing to compensate for the neurophysiological difficulties another association is with odontogenic keratocysts okc aka keratocystic odontogenic tumor who terminology of the jaw which may behave aggressively and have a high propensity to recur when treated with simple enucleation and curettage when seen together the patient is likely to have nevoid basal cell carcinoma syndrome aka gorlin goltz syndrome and should be evaluated with this in mind
bifurcation is a judge s ability in law to divide a trial into two parts so as to render a judgment on a set of legal issues without looking at all aspects frequently civil cases are bifurcated into separate liability and damages proceedings criminal trials are also often bifurcated into guilt and sentencing phases especially in capital cases in divorce cases some states allow bifurcation that permits a divorce case to be finalized with certain aspects such as property to be dealt with after dissolution some states permit bifurcation some do not allow it and some state statutes do not address the issue in arbitration bifurcation can be used to get past certain issues that might otherwise stall negotiations concluding certain points that are agreed upon while working on a solution to whatever problem initiated the need for bifurcation
bigeminal pulse is a medical condition easily confused with pulsus alternans similar features between bigeminal pulse and pulsus alternans are strong peak and weak peak however unlike pulsus alternans the weak beat in bigeminal pulse occurs prematurely early thus not followed a pause as it is in pulsus alternans but occurs close to normal strong beat
the biginelli reaction is a multiple component chemical reaction that creates 3 4 dihydropyrimidin 2 1 h ones 4 from ethyl acetoacetate 1 an aryl aldehyde such as benzaldehyde 2 and urea 3 it is named for the italian chemist pietro biginelli the biginelli reaction this reaction was developed by pietro biginelli in 1891 the reaction can be catalyzed by brønsted acids and or by lewis acids such as copper ii trifluoroacetate hydrate and boron trifluoride several solid phase protocols utilizing different linker combinations have been published dihydropyrimidinones the products of the biginelli reaction are widely used in the pharmaceutical industry as calcium channel blockers antihypertensive agents and alpha 1 a antagonists
in the mathematical theory of functions of one or more complex variables and also in complex algebraic geometry a biholomorphism or biholomorphic function is a bijective holomorphic function whose inverse is also holomorphic
in mathematics a bijection bijective function or one to one correspondence is a function between the elements of two sets where each element of one set is paired with exactly one element of the other set and each element of the other set is paired with exactly one element of the first set there are no unpaired elements in mathematical terms a bijective function f x → y is a one to one injective and onto surjective mapping of a set x to a set y a bijection from the set x to the set y has an inverse function from y to x if x and y are finite sets then the existence of a bijection means they have the same number of elements for infinite sets the picture is more complicated leading to the concept of cardinal number a way to distinguish the various sizes of infinite sets a bijective function from a set to itself is also called a permutation bijective functions are essential to many areas of mathematics including the definitions of isomorphism homeomorphism diffeomorphism permutation group and projective map
bilateral frontoparietal polymicrogyria bfpp is a genetic disorder with autosomal recessive inheritance that causes a cortical malformation our brain has folds in the cortex to increase surface area called gyri and patients with polymicrogyri have an increase number of folds and smaller folds than usual polymicrogyria is defined as a cerebral malformation of cortical development in which the normal gyral pattern of the surface of the brain is replaced by an excessive number of small fused gyri separated by shallow sulci and abnormal cortical lamination from ongoing research mutation in gpr 56 a member of the adhesion g protein coupled receptor gpcr family results in bfpp these mutations are located in different regions of the protein without any evidence of a relationship between the position of the mutation and phenotypic severity it is also found that gpr 56 plays a role in cortical pattering
bilateral hilar lymphadenopathy is a bilateral enlargement of the lymph nodes of pulmonary hila it is a radiographic term that describes the enlargement of mediastinal lymph nodes and is most commonly identified by a chest x ray
bile acid malabsorption known also as bile acid diarrhea is a cause of several gut related problems the main one being chronic diarrhea it has also been called bile acid induced diarrhea cholerheic or choleretic enteropathy and bile salt malabsorption it can result from malabsorption secondary to gastrointestinal disease or be a primary disorder associated with excessive bile acid production treatment with bile acid sequestrants is often effective
biliary atresia also known as extrahepatic ductopenia progressive obliterative cholangiopathy or kotb disease is a childhood disease of the liver in which one or more bile ducts are abnormally narrow blocked or absent it can be congenital or acquired as a birth defect in newborn infants it has an incidence of one in 10 000 – 15 000 live births in the united states and a prevalence of one in 16 700 in the british isles biliary atresia is most common in east asia with a frequency of one in 5 000 the causes of biliary atresia are not well understood congenital biliary atresia has been associated with certain genes while acquired biliary atresia is thought to be a result of an autoimmune inflammatory response possibly due to a viral infection of the liver soon after birth the only effective treatments are surgeries such as the kasai procedure and liver transplantation
biliary colic also known as a gallbladder attack is when pain occurs due to a gallstone temporarily blocking the bile duct typically the pain is in the right upper part of the abdomen and it can radiate to the shoulder pain usually lasts from one to a few hours often it occurs after eating a heavy meal or during the night repeated attacks are common gallstone formation occurs from the precipitation of crystals that aggregate to form stones the most common form is cholesterol gallstones other forms include calcium bilirubin pigment and mixed gallstones other conditions that produce similar symptoms include appendicitis stomach ulcers pancreatitis and gastroesophageal reflux disease treatment for gallbladder attacks is typically surgery to remove the gallbladder this can be either done through several small incisions or through a single larger incision surgery is typically done under general anesthesia in those who are unable to have surgery medication to try to dissolve the stones or shock wave lithotripsy may be tried in the developed world 10 15 of adults have gallstones of those with gallstones biliary colic occurs in 1 4 each year nearly 30 of people have further problems related to gallstones in the year following an attack about 15 of people with biliary colic eventually develop inflammation of the gallbladder if not treated other complications include inflammation of the pancreas
biliary dyskinesia is a disorder of some component of biliary part of the digestive system in which bile physically can not move normally in the proper direction through the tubular biliary tract it most commonly involves abnormal biliary tract peristalsis muscular coordination within the gallbladder in response to dietary stimulation of that organ to squirt the liquid bile through the common bile duct into the duodenum ineffective peristaltic contraction of that structure produces postprandial after meals right upper abdominal pain cholecystodynia and almost no other problem when the dyskinesia is localized at the biliary outlet into the duodenum just as increased tonus of that outlet sphincter of oddi the backed up bile can cause pancreatic injury with abdominal pain more toward the upper left side in general biliary dyskinesia is the disturbance in the coordination of peristaltic contraction of the biliary ducts and or reduction in the speed of emptying of the biliary tree into the duodenum normally the downstream gallbladder stores and concentrates the bile which originates in liver hepatocyte cells and is released into the microscopic component of the biliary system by the liver through aggregating tubules of increasing diameter the bile leaves the liver and reaches the upstream proximal component of the common bile duct apparently the common bile duct beyond distal to the gallbladder tends to normally have a greater tone so that the bile backs up into the gallbladder when bile enters the duodenum the first part of the small intestine it aids in digesting the fat within food leaving the stomach when the bile can not be properly propelled from the not mechanically obstructed gallbladder or can not flow out of the end of the common bile duct properly there is a state of biliary dyskinesia so biliary dyskinesia is a dynamically functional not fixed mechanical obstructive pain producing disorder obstruction by a stone or tumor is a static mechanical obstruction and tends to produce a more intense pain known as biliary colic failure of the biliary sphincter of oddi can be distinguished from failure of the pancreatic sphincter
biliary fever is an illness of the liver affecting horses dogs and cats this is currently the most common infectious disease of dogs in southern africa it is also known as tick bite fever or bosluiskoors in afrikaans it is caused by a tiny parasite babesia canis which is introduced into the body by a tick bite this parasite then enters and destroys red blood cells biliary in dogs has a lot in common with malaria in man except that in the latter a mosquito is the vector
a biliary fistula is a type of fistula in which bile flows along an abnormal connection from the bile ducts into nearby hollow structure types of biliary fistula include bilioenteric fistula abnormal connection to small bowel usually duodenum thoracobiliary fistula abnormal connection to pleural space or bronchus rare these may be contrasted to a bile leak in which bile escapes the bile ducts through a perforation or faulty surgical anastomosis into the abdominal cavity damage to a bile duct may result in a leak which may eventually become a biliary fistula
biliary injury bile duct injury is the traumatic damage of the bile ducts it is most commonly an iatrogenic complication of cholecystectomy — surgical removal of gall bladder but can also be caused by other operations or by major trauma the risk of biliary injury is more during laparoscopic cholecystectomy than during open cholecystectomy biliary injury may lead to several complications and may even cause death if not diagnosed in time and managed properly ideally biliary injury should be managed at a center with facilities and expertise in endoscopy radiology and surgery
biliary pruritus is caused by chronic liver disease with obstructive jaundice characterized by a severe generalized itchy sensation
biliary pseudolithiasis refers to an unusual complication of ceftriaxone where the drug complexes with calcium and mimics gallstones it is reversed when ceftriaxone administration is stopped it was first described in 1988 by schaad et al as reversible ceftriaxone associated biliary pseudolithiasis
biliary reflux bile reflux or duodenogastric reflux is a condition that occurs when bile flows upward refluxes from the duodenum into the stomach and esophagus biliary reflux can be confused with acid reflux also known as gastroesophageal reflux disease gerd while bile reflux involves fluid from the small intestine flowing into the stomach and esophagus acid reflux is backflow of stomach acid into the esophagus these conditions are often related and differentiating between the two can be difficult bile is a digestive fluid made by the liver stored in the gallbladder and discharged into duodenum after food is ingested to aid in the digestion of fat normally the pyloric sphincter prevents bile from entering the stomach when the pyloric sphincter is damaged or fails to work correctly bile can enter the stomach and then be transported into the esophagus as in gastric reflux the presence of small amounts of bile in the stomach is relatively common and usually asymptomatic but excessive refluxed bile causes irritation and inflammation
biliary sludge refers to a viscous mixture of small particles derived from bile these sediments consist of cholesterol crystals calcium salts calcium bilirubinate mucin and other materials
in mathematics a bilinear map is a function combining elements of two vector spaces to yield an element of a third vector space and is linear in each of its arguments matrix multiplication is an example
in mathematics a bilinear program is a nonlinear optimization problem whose objective or constraint functions are bilinear an example is the pooling problem
bilious fever was a medical diagnosis often used for any fever that exhibited the symptom of nausea or vomiting in addition to an increase in internal body temperature and strong diarrhea bilious means the condition was thought to arise from disorders of bile the two types of which were two of the four humours of traditional galenic medicine in 200 a d the term is obsolete and no longer used but was used by medical practitioners in the 18 th and 19 th centuries often cited as a cause on death certificates president lincoln s son willie was said to have died from bilious fever modern diagnoses for the same symptoms would include a wide range of conditions and infections
in medicine bilirubinuria is an abnormality in which conjugated bilirubin is detected in the urine the term biliuria is very similar but more general it refers to the presence of any bile pigment in the urine
the bill in lemon is an effect in which a magician requests a currency note from a spectator and makes the note vanish then proceeding to slice a lemon open to show the note inside variations include the coin in orange and more generally something in fruit
in telecommunications bill shock is the negative reaction a subscriber can experience if their phone bill has unexpected charges bill shock can happen when for example a user grossly overuses data applications without an appropriate data plan or uses a mobile device while roaming whether domestically or internationally without understanding the voice or data roaming charges involved bill shock can generically be used as a term for the surprise an individual receives on any bill that has an amount higher than expected pending to be paid other examples of bill shock have been noted in credit card bills rental bills and utility bills the use of non geographic telephone numbers in the united kingdom has also been a major cause of bill shock pollster yougov found that 49 of mobile users have been surprised to see how much they have been charged for calling non geographic numbers and 90 believe organisations should make the cost of these calls clearer according to ofcom uk consumers paid around £ 1 9 billion for calls to non geographic numbers in 2009
billet reading or the envelope trick is a mentalist effect in which a performer pretends to use clairvoyance to read messages on folded papers or inside sealed envelopes it is a widely performed standard of the mentalist craft since the middle of the 19 th century billet is the french term for note or letter referring to the rectangular shape of the paper
bilocation or sometimes multilocation is an alleged psychic or miraculous ability wherein an individual or object is located or appears to be located in two distinct places at the same time the concept has been used in a wide range of historical and philosophical systems ranging from early greek philosophy to modern religious stories occultism and magic
a bimalleolar fracture is a fracture of the ankle that involves the lateral malleolus and the medial malleolus studies have shown that bimalleolar fractures are more common in women people over 60 years of age and patients with existing comorbidities
binary distribution is the presence of two or more very large and dominant cities in a country
binasal hemianopsia or binasal hemianopia is the medical description of a type of partial blindness where vision is missing in the inner half of both the right and left visual field it is associated with certain lesions of the eye and of the central nervous system such as congenital hydrocephalus
binder s syndrome binder syndrome maxillo nasal dysplasia is a developmental disorder primarily affecting the anterior part of the maxilla and nasal complex nose and jaw it is a rare disorder and the causes are unclear hereditary and vitamin d deficiency during embryonic growth have been researched as possible causes the characteristics of the syndrome are typically visible the syndrome involves hypoplasia of variable severity of cartilaginous nasal septum and premaxilla it includes complete total absence of the anterior nasal spine there are also associated anomalies of muscle insertions of the upper lip and the nasal floor and of the cervical spine affected individuals typically have an unusually flat underdeveloped midface midfacial hypoplasia with an abnormally short nose and flat nasal bridge they have an underdeveloped upper jaw relatively protruding lower jaw with anterior mandibular vertical excess and a class iii skeletal and dental reverse overjet profile they have a small frontal sinus and global facial imbalance treatment is encouraged as early as possible with posteroanterior traction on the maxilla and at about age 8 reinsertion of the nasolabial muscles onto the anterior border of the cartilaginous system many who have a severe case of the disorder undergo plastic surgery or orthodontic treatment for cosmetic reasons
binge drinking or heavy episodic drinking is a modern epithet for drinking alcoholic beverages with an intention of becoming intoxicated by heavy consumption of alcohol over a short period of time it is a style of drinking that is popular in several countries worldwide and overlaps somewhat with social drinking since it is often done in groups the degree of intoxication however varies between and within various cultures that engage in this practice a binge on alcohol can occur over hours last up to several days or in the event of extended abuse even weeks due to the long term effects of alcohol misuse binge drinking is considered to be a major public health issue binge drinking is associated with a profound social harm economic costs as well as increased disease burden binge drinking is more common in males during adolescence and young adulthood heavy regular binge drinking is associated with adverse effects on neurologic cardiac gastrointestinal hematologic immune musculoskeletal organ systems as well as increasing the risk of alcohol induced psychiatric disorders a us based review of the literature found that up to one third of adolescents binge drink with six percent reaching the threshold of having an alcohol related substance use disorder approximately one in 25 women binge drinks during pregnancy which can lead to fetal alcohol syndrome and fetal alcohol spectrum disorders binge drinking during adolescence is associated with traffic accidents and other types of accidents violent behavior as well as suicide the more often a child or adolescent binge drinks and the younger they are the more likely that they will develop an alcohol use disorder including alcoholism a large number of adolescents who binge drink also consume other psychotropic substances binge drinking causes brain damage faster and more severely than chronic drinking alcoholism the neurotoxic insults are due to very large amounts of glutamate which are released and over stimulate the brain as a binge finishes this results in excitotoxicity a process which damages or kills neurons brain cells each binge drinking episode immediately insults the brain repeat episodes result in accumulating harm the developing adolescent brain is thought to be particularly susceptible to the neurotoxic effects of binge drinking with some evidence of brain damage occurring from drinking more than 10 or 11 drinks once or twice per month
binge eating is a pattern of disordered eating which consists of episodes of uncontrollable eating it is sometimes a symptom of binge eating disorder or compulsive overeating disorder during such binges a person rapidly consumes an excessive quantity of food a diagnosis of binge eating is associated with feelings of loss of control
binge eating disorder bed is characterized by binge eating without subsequent purging episodes the disorder was first described in 1959 by psychiatrist and researcher albert stunkard as night eating syndrome nes the term binge eating was coined to describe the same binging type eating behavior but without the exclusive nocturnal component binge eating is one of the most prevalent eating disorders among adults though there tends to be less media coverage and research about the disorder in comparison to anorexia nervosa and bulimia nervosa previously considered a topic for further research exploration binge eating disorder was included in the eating disorders section of the dsm 5 in 2013 bed is present in 0 8 of male u s adults and 1 6 of female u s adults in a given year
the bingel reaction in fullerene chemistry is a fullerene cyclopropanation reaction to a methanofullerene first discovered by c bingel in 1993 with the bromo derivative of diethyl malonate in the presence of a base such as sodium hydride or dbu the preferred double bonds for this reaction on the fullerene surface are the shorter bonds at the junctions of two hexagons 6 6 bonds and the driving force is relief of steric strain the reaction is of importance in the field of chemistry because it allows the introduction of useful extensions to the fullerene sphere these extensions alter their properties for instance solubility and electrochemical behavior and therefore widen the range of potential technical applications
bing – neel syndrome bns is an extremely rare neurologic complication of waldenström macroglobulinemia wm it was first described in 1936 by jens bing and axel valdemar neel who observed a case of 2 women 56 and 39 years old presenting with rapid neurodegeneration in the setting of hyperglobulinemia it involves central nervous system infiltration by neoplastic lymphoplasmacytoid and plasma cells with or without cerebrospinal fluid csf hyperglobulinemia this increases blood viscosity which impairs its circulation through small brain and eye blood vessels patients with bns can be classified into group a and group b based on the presence of these cells within the brain parenchyma leptomeninges dura and or the csf symptoms include episodes of confusion slurred speech headache fatigue ataxia memory problems nausea vomiting and extremity numbness complete blood count electrolytes and liver enzymes are normal in patients with bing – neel syndrome diagnosis can include lumbar puncture and magnetic resonance imaging mri of the brain and spinal cord treatment involves central nervous system penetrating chemotherapy some significant improvement has been shown in patients as a result of cranial radiation treatment preceding a brief course of intrathecal chemotherapy in arkansas a patient was treated with intrathecal chemotherapy with several cycles of systemic chemotherapy followed by autologous stem cell supported high dose therapy transplant the patient discontinued all treatment in 2009 and was still asymptomatic by the time a follow up report was published in 2013
binocular dysphoria is a hypothesized condition where the brain adapts to an alternative way of perceiving depth cues 3 d films televisions virtual reality headsets and other devices simulate the experience of three dimensions through stereoscopic techniques presenting slightly different images to the left and right eyes through stereo vision the primary cue for human depth perception the brain interprets the images as being in three dimensions however current technology does not allow the displays to simulate the many other cues to depth perception so most viewers ignore those cues while viewing 3 d displays virtual reality researcher mark pesce argues citing research in japan britain and america that there is an adjustment period after watching simulated 3 d during which vision is impaired and that overconsumption of 3 d content could lead to increased risk of accidents or even permanent impairment pesce says that an unreleased product safety study by sega led the company to cancel the release of a head mounted display for the sega genesis in the mid 1990 s at present there is no peer reviewed evidence of this condition
binocular rivalry is a phenomenon of visual perception in which perception alternates between different images presented to each eye when one image is presented to one eye and a very different image is presented to the other also known as dichoptic presentation instead of the two images being seen superimposed one image is seen for a few moments then the other then the first and so on randomly for as long as one cares to look for example if a set of vertical lines is presented to one eye and a set of horizontal lines to the same region of the retina of the other sometimes the vertical lines are seen with no trace of the horizontal lines and sometimes the horizontal lines are seen with no trace of the vertical lines at transitions brief unstable composites of the two images may be seen for example the vertical lines may appear one at a time to obscure the horizontal lines from the left or from the right like a traveling wave switching slowly one image for the other binocular rivalry occurs between any stimuli that differ sufficiently including simple stimuli like lines of different orientation and complex stimuli like different alphabetic letters or different pictures such as of a face and of a house very small differences between images however might yield singleness of vision and stereopsis binocular rivalry has been extensively studied in the last century in recent years neuroscientists have used neuroimaging techniques and single cell recording techniques to identify neural events responsible for the perceptual dominance of a given image and for the perceptual alternations
binswanger s disease also known as subcortical leukoencephalopathy is a form of small vessel vascular dementia caused by damage to the white brain matter white matter atrophy can be caused by many circumstances including chronic hypertension as well as old age this disease is characterized by loss of memory and intellectual function and by changes in mood these changes encompass what are known as executive functions of the brain it usually presents between 54 and 66 years of age and the first symptoms are usually mental deterioration or stroke it was described by otto binswanger in 1894 and alois alzheimer first used the phrase binswanger s disease in 1902 however olszewski is credited with much of the modern day investigation of this disease which began in 1962
binucleated cells are cells that contain two nuclei this type of cell is most commonly found in cancer cells and may arise from a variety of causes binucleation can be easily visualized through staining and microscopy in general binucleation has negative effects on cell viability and subsequent mitosis they also occur physiologically in hepatocytes chondrocytes and in fungi dikaryon
biochemical oxygen demand bod also called biological oxygen demand is the amount of dissolved oxygen needed i e demanded by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period the bod value is most commonly expressed in milligrams of oxygen consumed per litre of sample during 5 days of incubation at 20 nbsp ° c and is often used as a surrogate of the degree of organic pollution of water bod can be used as a gauge of the effectiveness of wastewater treatment plants it is listed as a conventional pollutant in the u s clean water act bod is similar in function to chemical oxygen demand cod in that both measure the amount of organic compounds in water however cod is less specific since it measures everything that can be chemically oxidized rather than just levels of biodegradable organic matter
bioconcentration is the accumulation of a chemical in or on an organism when the source of chemical is solely water bioconcentration is a term that was created for use in the field of aquatic toxicology bioconcentration can also be defined as the process by which a chemical concentration in an aquatic organism exceeds that in water as a result of exposure to a waterborne chemical there are several ways in which to measure and assess bioaccumulation and bioconcentration these include octanol water partition coefficients kow bioconcentration factors bcf bioaccumulation factors baf and biota sediment accumulation factor bsaf each of these can be calculated using either empirical data or measurements as well as from mathematical models one of these mathematical models is a fugacity based bcf model developed by don mackay bioconcentration factor can also be expressed as the ratio of the concentration of a chemical in an organism to the concentration of the chemical in the surrounding environment the bcf is a measure of the extent of chemical sharing between an organism and the surrounding environment in surface water the bcf is the ratio of a chemical s concentration in an organism to the chemical s aqueous concentration bcf is often expressed in units of liter per kilogram ratio of mg of chemical per kg of organism to mg of chemical per liter of water bcf can simply be an observed ratio or it can be the prediction of a partitioning model a partitioning model is based on assumptions that chemicals partition between water and aquatic organisms as well as the idea that chemical equilibrium exists between the organisms and the aquatic environment in which it is found
biodilution is the decrease in concentration of an element or pollutant with an increase in trophic level this effect is primarily caused by the observed trend that an increase in algal biomass will reduce the overall concentration of a pollutant per cell which ultimately contributes to a lower dietary input to grazers and higher level aquatic organisms the primary elements and pollutants of concern are heavy metals such as mercury cadmium and lead these toxins have been shown to bioaccumulate up a food web in some cases metals such as mercury can biomagnify this is a major concern since methylmercury the most toxic mercury species can be found in high concentrations in human consumed fish and other aquatic organisms persistent organic pollutants such as carcinogenic polycyclic aromatic hydrocarbons and alkylphenols have also shown to biodilute in the marine environment numerous studies have linked lower mercury concentrations in zooplankton found in eutrophic nutrient rich and highly productive as compared to oligotrophic low nutrient aquatic environments nutrient enrichment mainly phosphorus and nitrogen reduce the input of mercury and other heavy metals into aquatic food webs through this biodilution effect primary producers such as phytoplankton uptake these heavy metals and accumulate them into their cells the higher the population of phytoplankton the less concentrated these pollutants will be in their cells once consumed by primary consumers such as zooplankton these phytoplankton bound pollutants are incorporated into the consumer ’ s cells higher phytoplankton biomass means a lower concentration of pollutants accumulated by the zooplankton and so on up the food web this effect causes an overall dilution of the original concentration up the food web that is the concentration of a pollutant will be lower in the zooplankton than the phytoplankton in a high bloom condition although most biodilution studies have been on freshwater environments biodilution has been shown to occur in the marine environment as well the northwater polynya located in baffin bay was found to have a negative correlation of cadmium lead and nickel with an increase in trophic level cadmium and lead are both non essential metals that will compete for calcium within an organism which is detrimental for organism growth most studies measure bioaccumulation and biodilution using the δ 15 n isotope of nitrogen the δ 15 n isotopic signature is enriched up the food web a predator will have a higher δ 15 n as compared to its prey this trend allows the tropic position of an organism to be derived coupled to the concentration of a specific pollutant such as mercury the concentration verses trophic position can be accessed while most heavy metals bioaccumulate under certain conditions heavy metals and organic pollutants have the potential to biodilute making a higher organism less exposed to the toxin
biofouling or biological fouling is the accumulation of microorganisms plants algae or animals on wetted surfaces such accumulation is referred to as epibiosis when the host surface is another organism and the relationship is not parasitic antifouling is the ability of specifically designed materials and coatings to remove or prevent biofouling by any number of organisms on wetted surfaces since biofouling can occur almost anywhere water is present biofouling poses risks to a wide variety of objects such as medical devices and membranes as well as to entire industries such as paper manufacturing food processing underwater construction and desalination plants specifically the buildup of biofouling on marine vessels poses a significant problem in some instances the hull structure and propulsion systems can be damaged the accumulation of biofoulers on hulls can increase both the hydrodynamic volume of a vessel and the hydrodynamic friction leading to increased drag of up to 60 the drag increase has been seen to decrease speeds by up to 10 which can require up to a 40 increase in fuel to compensate with fuel typically comprising up to half of marine transport costs antifouling methods are estimated to save the shipping industry around 60 billion per year increased fuel use due to biofouling contributes to adverse environmental effects and is predicted to increase emissions of carbon dioxide and sulfur dioxide between 38 and 72 by 2020 a variety of antifouling methods have historically been implemented to combat biofouling recently scientists have begun researching antifouling methods inspired by living organisms this type of design imitation is known as biomimicry
biohydrometallurgy is a subfield within hydrometallurgy which includes aspects of biotechnology
bioimage informatics is a subfield of bioinformatics and computational biology it focuses on the use of computational techniques to analyze bioimages especially cellular and molecular images at large scale and high throughput the goal is to obtain useful knowledge out of complicated and heterogeneous image and related metadata automated microscopes are able to collect large amounts of images with minimal intervention this has led to a data explosion which absolutely requires automatic processing additionally and surprisingly for several of these tasks there is evidence that automated systems can perform better than humans in addition automated systems are unbiased unlike human based analysis whose evaluation may even unconsciously be influenced by the desired outcome there has been an increasing focus on developing novel image processing computer vision data mining database and visualization techniques to extract compare search and manage the biological knowledge in these data intensive problems
biomagnetism is the phenomenon of magnetic fields produced by living organisms it is a subset of bioelectromagnetism in contrast organisms use of magnetism in navigation is magnetoception and the study of the magnetic fields effects on organisms is magnetobiology the word biomagnetism has also been used loosely to include magnetobiology further encompassing almost any combination of the words magnetism cosmology and biology such as magnetoastrobiology the origin of the word biomagnetism is unclear but seems to have appeared several hundred years ago linked to the expression animal magnetism the present scientific definition took form in the 1970 s when an increasing number of researchers began to measure the magnetic fields produced by the human body the first valid measurement was actually made in 1963 but the field of research began to expand only after a low noise technique was developed in 1970 today the community of biomagnetic researchers does not have a formal organization but international conferences are held every two years with about 600 attendees most conference activity centers on the meg magnetoencephalogram the measurement of the magnetic field of the brain
biomanipulation is the deliberate alteration of an ecosystem by adding or removing species especially predators
biopitting is a geologic phenomenon that occurs when small pits are created in rock as a result of the bioerosion induced by different organisms and or microorganisms for example fungi bacteria algae lichens this phenomenon occurs when the organisms grow on or near the surface of rocks
biorientation is the phenomenon whereby microtubules emanating from different microtubule organizing centres mtocs attach to kinetochores of sister chromatids this results in the sister chromatids moving to opposite poles of the cell during cell division and thus results in both daughter cells having the same genetic information kinetochores link the chromosomes to the mitotic spindle doing so relies on intricate interactions between microtubules and kinetochores it has been shown that in fission yeast microtubule attachment can make frequent erroneous attachments early in mitosis which are then often corrected prior to anaphase onset by a system which uses protein kinase to affect kinetochore microtubules ktmts in the absence of astriction between sister chromatids proper biorientation allows correct chromosomal segregation in cell division although this process is not well understood high resolution imaging of live mouse oocytes has revealed that chromosomes form an intermediate chromosomal configuration called the prometaphase belt which occurs prior to biorientation kitajima et al estimate that about 90 of chromosomes require correction of the kinetochore microtubule attachments using aurora kinase prior to obtaining correct biorientation this suggests a possible cause for the elevated frequency of abnormal chromosome counts aneuploidy in mammals several methods are postulated by which chromosomes biorient when they are located far from the pole with which they need to connect one mechanism involves the kinetchore meeting microtubules from the distal pole another method described is based on observations that the kinetochore of one pole oriented chromosome attaches to kinetochore fibers of an already bioriented chromosome these two mechanisms possibly work in concert certain chromosomes may biorient via encounters with microtubules from distal poles which is then followed by kinetochore fibers that speed up biorientation with already oriented chromosomes researchers have detached grasshopper spermatocytes from spindle fibers and moved them away from the metaphase plate via micromanipulation several chromosomes instantly bioriented as deduced from the observation that upon reattachment the chromosomes moved to the metaphase plate without moving to the poles
biostasis is the ability of an organism to tolerate environmental changes without having to actively adapt to them the word is also used as a synonym for cryostasis or cryonics it is found in organisms that live in habitats that may encounter unfavourable living conditions e g drought freezing a change in ph pressure or temperature insects undergo diapause which allows them to survive winter and other events diapause may be obligatory required for the insect to survive or facultative the insect is able to undergo change before the initiating event arrives medical biostasis can be put to use in humans to help repair brain damage depending on where medicine is in the next decade medical biostasis procedures can be performed by trauma surgeons by 2026
biot s respiration is an abnormal pattern of breathing characterized by groups of quick shallow inspirations followed by regular or irregular periods of apnea it is named for camille biot who characterized it in 1876
biotic stress is stress that occurs as a result of damage done to plants by other living organisms such as bacteria viruses fungi parasites beneficial and harmful insects weeds and cultivated or native plants not to be confused with abiotic stress which is the negative impact of non living factors on the organisms in a specific environment such as sunlight wind salinity over watering and drought the types of biotic stresses imposed on a plant depend on both geography and climate and on the host plant and its ability to resist particular stresses although there are many kinds of biotic stress the majority of plant diseases are caused by fungi biotic stress remains a broadly defined term and those who study it face many challenges such as the greater difficulty in controlling biotic stresses in an experimental context compared to abiotic stress the damage caused by these various living and nonliving agents can appear very similar even with close observation accurate diagnosis can be difficult for example browning of leaves on an oak tree caused by drought stress may appear similar to leaf browning caused by oak wilt a serious vascular disease or the browning cause by anthracnose a fairly minor leaf disease
biotin deficiency is a rare nutritional disorder which can become serious even fatal if allowed to progress untreated it can occur in people of any age ancestry or gender biotin is part of the b vitamin family biotin deficiency rarely occurs among healthy people because the daily requirement of biotin is low many foods provide adequate amounts of it intestinal bacteria synthesize small amounts of it and the body effectively scavenges and recycles it from bodily waste however deficiencies can be caused by consuming raw egg whites over a period of months to years egg whites contain high levels of avidin a protein that binds biotin strongly when cooked avidin is partially denatured and binding to biotin is reduced however one study showed that 30 40 of the avidin activity was still present in the white after frying or boiling hence excessive cooked egg white consumption could possibly cause biotin deficiency genetic disorders such as biotinidase deficiency multiple carboxylase deficiency and holocarboxylase synthetase deficiency can also lead to inborn or late onset forms of biotin deficiency in all cases – dietary genetic or otherwise – supplementation with biotin is the primary method of treatment
biotinidase deficiency is an autosomal recessive metabolic disorder in which biotin is not released from proteins in the diet during digestion or from normal protein turnover in the cell this situation results in biotin deficiency biotin also called vitamin b 7 is an important water soluble nutrient that aids in the metabolism of fats carbohydrates and proteins biotin deficiency can result in behavioral disorders lack of coordination learning disabilities and seizures biotin supplementation can alleviate and sometimes totally arrest such symptoms
bipartite patella also known as patella bipartita is a condition where the patella or kneecap is composed of two separate bones instead of fusing together in early childhood the bones of the patella remain separated the condition occurs in approximately 1 – 2 of the population and is nine times more likely to occur in males than females it is often asymptomatic and most commonly diagnosed as an incidental finding with about 2 of cases becoming symptomatic
a biphasic disease is a disease which has two distinct phases
bipolar ii disorder bp ii pronounced type two bipolar disorder is a bipolar spectrum disorder see also bipolar disorder characterized by at least one episode of hypomania and at least one episode of major depression diagnosis for bipolar ii disorder requires that the individual must never have experienced a full manic episode unless it was caused by an antidepressant medication otherwise one manic episode meets the criteria for bipolar i disorder hypomania is a sustained state of elevated or irritable mood that is less severe than mania and does not significantly impact quality of life unlike mania hypomania is not associated with psychosis the hypomanic episodes associated with bipolar ii disorder must last for at least four days commonly depressive episodes are more frequent and more intense than hypomanic episodes additionally when compared to bipolar i disorder type ii presents more frequent depressive episodes and shorter intervals of well being the course of bipolar ii disorder is more chronic and consists of more frequent cycling than the course of bipolar i disorder finally bipolar ii is associated with a greater risk of suicidal thoughts and behaviors than bipolar i or unipolar depression although bipolar ii is commonly perceived to be a milder form of type i this is not the case types i and ii present equally severe burdens bipolar ii is difficult to diagnose patients usually seek help when they are in a depressed state because the symptoms of hypomania are often mistaken for high functioning behavior or simply attributed to personality patients are typically not aware of their hypomanic symptoms as a result they are unable to provide their doctor with all the information needed for an accurate assessment these individuals are often misdiagnosed with unipolar depression of all individuals initially diagnosed with major depressive disorder between 40 and 50 will later be diagnosed with either bp i or bp ii substance abuse disorders which have high co morbidity with bp ii and periods of mixed depression may also make it more difficult to accurately identify bp ii despite the difficulties it is important that bp ii individuals be correctly assessed so that they can receive the proper treatment antidepressant use in the absence of mood stabilizers is correlated with worsening bp ii symptoms
bipolar i disorder bp i pronounced type one bipolar disorder is a bipolar spectrum disorder characterized by the occurrence of at least one manic or mixed episode most patients also at other times have one or more depressive episodes and all experience a hypomanic stage before progressing to full mania it is a type of bipolar disorder and conforms to the classic concept of manic depressive illness which can include psychosis during mood episodes the difference with bipolar ii disorder is that the latter requires that the individual must never have experienced a full manic or mixed manic episode only less severe hypomanic episode s
bipolar disorder formerly manic depression is a mental disorder with periods of depression and periods of elevated mood the elevated mood is significant and is known as mania or hypomania depending on its severity or whether symptoms of psychosis are present during mania an individual behaves or feels abnormally energetic happy or irritable individuals often make poorly thought out decisions with little regard to the consequences the need for sleep is usually reduced during manic phases during periods of depression there may be crying a negative outlook on life and poor eye contact with others the risk of suicide among those with the illness is high at greater than 6 percent over 20 years while self harm occurs in 30 – 40 percent other mental health issues such as anxiety disorders and substance use disorder are commonly associated the causes are not clearly understood but both environmental and genetic factors play a role many genes of small effect contribute to risk environmental factors include a history of childhood abuse and long term stress it is divided into bipolar i disorder if there is at least one manic episode and bipolar ii disorder if there are at least one hypomanic episode and one major depressive episode in those with less severe symptoms of a prolonged duration the condition cyclothymic disorder may be present if due to drugs or medical problems it is classified separately other conditions that may present in a similar manner include attention deficit hyperactivity disorder personality disorders schizophrenia and substance use disorder as well as a number of medical conditions medical testing is not required for a diagnosis however blood tests or medical imaging can be done to rule out other problems treatment commonly includes psychotherapy as well as medications such as mood stabilizers and antipsychotics examples of mood stabilizers that are commonly used include lithium and anticonvulsants treatment in hospital against a person s consent may be required at times as people may be a risk to themselves or others yet refuse treatment severe behavioral problems may be managed with short term antipsychotics or benzodiazepines in periods of mania it is recommended that antidepressants be stopped if antidepressants are used for periods of depression they should be used with a mood stabilizer electroconvulsive therapy ect may be helpful for those who do not respond to other treatments if treatments are stopped it is recommended that this be done slowly many individuals have financial social or work related problems due to the illness these difficulties occur a quarter to a third of the time on average the risk of death from natural causes such as heart disease is twice that of the general population this is due to poor lifestyle choices and the side effects from medications about 3 percent of people in the us are estimated to have bipolar disorder at some point in their life lower rates of around 1 percent are found in other countries the most common age at which symptoms begin is 25 rates appear to be similar in females as males the economic costs of the disorder has been estimated at 45 billion for the united states in 1991 a large proportion of this was related to a higher number of missed work days estimated at 50 per year people with bipolar disorder often face problems with social stigma
bipolar disorder bd in children or pediatric bipolar disorder pbd is a condition that affects mood and energy it is characterized by extreme changes in mood that range from depressive lows to manic highs it has been a controversial diagnosis with big differences in how commonly it is diagnosed across clinics and countries until the 1990 s bipolar disorder was thought to be rare in children and adolescents there has been a rapid increase in research on the topic but training and clinical practice lag behind identifying bd in youth is challenging because while adults with bd often have distinct periods of depression and mania that last for weeks months or longer youth diagnosed with bd frequently have depressive and manic symptoms that occur daily and sometimes simultaneously either as rapid shifts or periods of high energy negative mood comorbid disorders are common which makes determining what symptoms are signs of bd and which are due to other disorders e g depression adhd disruptive behavior problems crucial both for accurate diagnosis and effective treatment
bipolar disorder not otherwise specified bd nos is a diagnosis for bipolar disorder bd when it does not fall within the other established sub types bipolar disorder nos is sometimes referred to as subthreshold bipolar disorder
bipolar electrochemistry is a phenomenon in electrochemistry based on the polarization of conducting objects in electric fields indeed this polarization generates a potential difference between the two extremities of the substrate that is equal to the electric field value multiplied by the size of the object if this potential difference is important enough then redox reactions can be generated at the extremities of the object oxidations will occur at one extremity coupled simultaneously to reductions at the other extremity in a simple experimental setup consisting of a platinum wire in a weighing boat containing a ph indicator solution a 30 v voltage across two electrodes will cause water reduction at one end of the wire the cathode and a ph increase oh − formation and water oxidation at the anodic end and a ph decrease the poles of the bipolar electrode also align themselves with the applied electric field
in mathematics the birch and swinnerton dyer conjecture describes the set of rational solutions to equations defining an elliptic curve it is an open problem in the field of number theory and is widely recognized as one of the most challenging mathematical problems the conjecture was chosen as one of the seven millennium prize problems listed by the clay mathematics institute which has offered a 1 000 000 prize for the first correct proof it is named after mathematicians bryan birch and peter swinnerton dyer who developed the conjecture during the first half of the 1960 s with the help of machine computation as of 2016 only special cases of the conjecture have been proved the conjecture relates arithmetic data associated to an elliptic curve e over a number field k to the behaviour of the hasse – weil l function l e s of e at s 1 more specifically it is conjectured that the rank of the abelian group e k of points of e is the order of the zero of l e s at s 1 and the first non zero coefficient in the taylor expansion of l e s at s 1 is given by more refined arithmetic data attached to e over k
the birch reduction is an organic reaction which is particularly useful in synthetic organic chemistry the reaction was reported in 1944 by the australian chemist arthur birch 1915 – 1995 working in the dyson perrins laboratory in the university of oxford building on earlier work by wooster and godfrey in 1937 it converts aromatic compounds having a benzenoid ring into a product 1 4 cyclohexadienes in which two hydrogen atoms have been attached on opposite ends of the molecule it is the organic reduction of aromatic rings in liquid ammonia with sodium lithium or potassium and an alcohol such as ethanol and tert butanol this reaction is quite unlike catalytic hydrogenation which usually reduces the aromatic ring all the way to a cyclohexane the original reaction reported by arthur birch in 1944 utilized sodium and ethanol subsequently a l wilds noted that better yields result with lithium also the use of t butyl alcohol has become common the reaction is one of the main organic reactions utilized in all types of syntheses the birch reduction an example is the reduction of naphthalene naphthalene birch reduction several reviews have been published
bird skyscraper collisions are a problem in urban areas several major cities like toronto in canada and new york city in the united states have programs to abate this such as toronto s fatal light awareness program flap and new york city s lights out new york a program of new york city audubon an environmental organization according to flap between one and nine million birds die each year in the city from hitting skyscrapers due to mistaking reflective windows for open sky or being drawn to lights at night
bird fallout or migration fallout is the phenomenon resulting from severe weather preventing migratory birds from reaching their destination this can occur while birds are traveling south or returning to their breeding grounds due to the distance travelled birds will not have enough energy to continue flight when encountering high winds this exhaustion results in a large amount of birds resting in one area this may be extremely stressful on the birds as well as the surrounding ecology bird fallout isn ’ t particularly common as it stems from the chance event of severe winds found in inclement weather due to the rare occurrence of a migratory fallout as well as the abundance of birds resting in a single location it is a sought after event for birders
bird fancier s lung is a type of hypersensitivity pneumonitis caused by bird droppings the lungs become inflamed with granuloma formation bird fancier s lung bfl also called bird breeder s lung and pigeon breeder s lung is a subset of hypersensitivity pneumonitis hp this disease is caused by the exposure to avian proteins present in the dry dust of the droppings and sometimes in the feathers of a variety of birds birds such as pigeons parakeets cockatiels shell parakeets budgerigars parrots turtle doves turkeys and chickens have been implicated people who work with birds or own many birds are at risk bird hobbyists and pet store workers may also be at risk
birdshot chorioretinopathy is a rare form of bilateral posterior uveitis affecting the eye it causes severe progressive inflammation of both the choroid and retina affected individuals are almost exclusively caucasian and usually diagnosed in the fourth to sixth decade of their lives
the birmingham riot of 1963 was a civil disorder in birmingham alabama that was provoked by bombings on the night of may 11 1963 the bombings targeted black leaders of the birmingham campaign a mass protest for racial justice bombed were the parsonage of rev a d king brother of martin luther king jr and a motel owned by a g gaston where king and his team had stayed martin luther king jr was a leader of the birmingham civil rights campaign which had been conducted that spring with large non violent demonstrations and mass arrest of schoolchildren who were demonstrating witnesses saw birmingham police place bombs at the parsonage which was partially destroyed all the family escaped the bombings were probably planned and carried out by members of the ku klux klan since the 1950 s kkk members in birmingham had used bombings against civil rights leaders and blacks who started to move into good neighborhoods after the attacks blacks in the area began to riot because of the police involvement and were repressed severely by the birmingham police department the united states government intervened with federal troops for the first time to control black violence it was the first time the government had used military troops independently of enforcing a court injunction this federal action was considered controversial by governor wallace and other alabama whites the bombings and police response were a pivotal event that contributed to president kennedy s decision to propose civil rights legislation to achieve relief of injustice it was passed under president lyndon b johnson as the civil rights act of 1964
birth trauma bt refers to damage of the tissues and organs of a newly delivered child often as a result of physical pressure or trauma during childbirth the term also encompasses the long term consequences often of a cognitive nature of damage to the brain or cranium medical study of birth trauma dates to the 16 th century and the morphological consequences of mishandled delivery are described in renaissance era medical literature birth injury occupies a unique area of concern and study in the medical canon in icd 10 birth trauma occupied 49 individual codes p 10 р 15 however there are often clear distinctions to be made between brain damage caused by birth trauma and that induced by intrauterine asphyxia it is also crucial to distinguish between birth trauma and birth injury birth injuries encompass any systemic damages incurred during delivery hypoxic toxic biochemical infection factors etc but birth trauma focuses largely on mechanical damage caput succedaneum subcutaneous hemorrhages small subperiostal hemorrhages hemorrhages along the displacements of cranial bones intradural bleedings subcapsular haematomas of liver are among the more commonly reported birth injuries birth trauma on the other hand encompasses the enduring side effects of physical birth injuries including the ensuing compensatory and adaptive mechanisms and the development of pathological processes pathogenesis after the damage
a birthmark is a congenital benign irregularity on the skin which is present at birth or appears shortly after birth usually in the first month they can occur anywhere on the skin birthmarks are caused by overgrowth of blood vessels melanocytes smooth muscle fat fibroblasts or keratinocytes dermatologists divide birthmarks into two types pigmented birthmarks caused by excess skin pigment cells include moles café au lait spots and mongolian spots vascular birthmarks also called red birthmarks are caused by increased blood vessels and include macular stains salmon patches hemangiomas and port wine stains a little over 1 in 10 babies have a vascular birthmark present by age 1 several birthmark types are part of the group of skin lesions known as nevi or naevi which means birthmarks in latin the exact cause of most birthmarks is unknown but they are thought to occur as a result of a localized imbalance in factors controlling the development and migration of skin cells in addition it is known that vascular birthmarks are not hereditary
birt – hogg – dubé syndrome bhd also hornstein – birt – hogg – dubé syndrome hornstein – knickenberg syndrome and fibrofolliculomas with trichodiscomas and acrochordons is a human autosomal dominant genetic disorder that can cause susceptibility to kidney cancer renal and pulmonary cysts and noncancerous tumors of the hair follicles called fibrofolliculomas the symptoms seen in each family are unique and can include any combination of the three symptoms fibrofolliculomas are the most common manifestation found on the face and upper trunk in over 80 of people with bhd over the age of 40 pulmonary cysts are equally common 84 but only 24 of people with bhd eventually experience a collapsed lung spontaneous pneumothorax kidney tumors both cancerous and benign occur in 14 – 34 of people with bhd the associated kidney cancers are often rare hybrid tumors any of these conditions that occurs in a family can indicate a diagnosis of birt – hogg – dubé syndrome though it is only confirmed by a genetic test for a mutation in the flcn gene which codes for the protein folliculin though its function is not fully understood it appears to be a tumor suppressor gene that restricts cell growth and division versions of flcn have been found in other animals including fruit flies german shepherds rats and mice the disease was discovered in 1977 but the connection with flcn was not elucidated until 2002 after kidney cancer collapsed lungs and pulmonary cysts were all definitively connected to bhd birt – hogg – dubé syndrome can manifest similarly to other diseases which must be ruled out when making a diagnosis these include tuberous sclerosis which causes skin lesions similar to fibrofolliculomas and von hippel lindau disease which causes hereditary kidney cancers once diagnosed people with bhd are treated preventatively with monitoring of kidneys and lungs using medical imaging fibrofolliculomas can be removed surgically and pneumothorax and kidney cancer are treated according to the normal standard of care
the bischler – möhlau indole synthesis is a chemical reaction that forms a 2 aryl indole from an α bromo acetophenone and excess aniline it is named after august bischler and richard möhlau the bischler möhlau indole synthesis in spite of its long history this classical reaction has received relatively little attention in comparison with other methods for indole synthesis perhaps owing to the harsh reaction conditions that it requires recently milder methods have been developed including the use of lithium bromide as a catalyst and an improved procedure involving the use of microwave irradiation
the bischler – napieralski reaction is an intramolecular electrophilic aromatic substitution reaction that allows for the cyclization of β arylethylamides or β arylethylcarbamates it was first discovered in 1893 by august bischler and bernard napieralski in affiliation with basle chemical works and the university of zurich the reaction is most notably used in the synthesis of dihydroisoquinolines which can be subsequently oxidized to isoquinolines
bismuthia is a rare dermatological condition that results from the prolonged use of bismuth much more rarely than with silver bismuth may produce a generalized persistent skin discoloration resembling argyria this is known as bismuthia the conjunctivae and oral mucosa as well as skin are commonly afflicted by the condition pigment granules are evenly scattered through the dermis producing a blue or bluish gray skin color by the scattering phenomenon it is extremenly rare and as a consequence is poorly understood by modern medicine special stains and spectroscopic methods must be utilized for identification of skin pigments affected by bismuth usually bismuth produces a black line due to bismuth sulfide along the gums near the teeth similar to a lead line this is not likely to occur if the gum is edentulous or the gum and the teeth normal it is more common when gingivitis and carious teeth are present bismuth excess may cause stomatitis on even rarer occasions bismuth has been reported to cause pigmentation of the vagina and cervix
bisphosphonate associated osteonecrosis of the jaw often abbreviated as bon bonj or bon of the jaw also called bisphosphonate related osteonecrosis of the jaw bronj pronounced brɒndʒ or bisphosphonate induced osteonecrosis of the jaw bionj is osteonecrosis of the jaw in a person with a history of bisphosphonate use who undergoes subsequent dental surgery it may lead to surgical complication in the form of impaired wound healing following oral and maxillofacial surgery periodontal surgery or endodontic therapy a correlation between history of bisphosphonate use and osteonecrosis of the jaw after later surgery was detected in the oral medicine fields for several years before the exact nature of the relationship etiology pathogenesis could begin to be understood and it is still not entirely clear although it has been nicknamed bis phossy jaw based on its similarity with phossy jaw there is no known prevention for bisphosphonate associated osteonecrosis of the jaw avoiding the use of bisphosphonates is not a viable prevention on a general population basis because the drugs have more benefit throughout the population preventing osteoporotic fractures and treating bone cancers than harm bronj
in digital transmission bit slip is the loss or gain of a bit or bits caused by clock drift – variations in the respective clock rates of the transmitting and receiving devices one cause of bit slippage is overflow of a receive buffer that occurs when the transmitter s clock rate exceeds that of the receiver this causes one or more bits to be dropped for lack of storage capacity one way to maintain timing between transmitting and receiving devices is to employ an asynchronous protocol such as start stop alternatively bit slip can be prevented by using a self clocking signal such as a signal modulated using oqpsk or using a line coding such as manchester encoding another cause is losing count as on a hard drive if a hard drive encounters a long string of 0 s without any 1 s or a string of 1 s without 0 s it may lose track of the frame between fields and suffer bit slip when a pulse of n consecutive zero bits are sent clock drift may cause the hardware to apparently detect n 1 zero bits or n 1 zero bits — both kinds of errors are called bit slip thus one prevents long strings without change via such devices as run length limited codes many communication systems use linear feedback shift register scrambling to prevent long strings of 0 s or other symbol including vsat 1000 base t etc while a scrambler makes the losing count type of bit slip error occur far less often when bit slip errors do occur perhaps for other reasons scramblers have the property of expanding small errors that add or lose a single bit into a much longer burst of errors the optimized cipher feedback mode ocfb the statistical self synchronization mode and the one bit cfb mode also expand small bit slip errors into a longer burst of errors but eventually recover and produce the correct decrypted plaintext a bit slip error when using any other block cipher mode of operation generally results in complete corruption of the rest of the message
a bitcrusher is a lo fi low fidelity digital audio effect which produces a distortion by the reduction of the resolution or bandwidth of digital audio data the resulting quantization noise may produce a “ warmer ” sound impression or a harsh one depending on the amount of reduction
bitemporal hemianopsia aka bitemporal heteronymous hemianopsia or bitemporal hemianopia is the medical description of a type of partial blindness where vision is missing in the outer half of both the right and left visual field it is usually associated with lesions of the optic chiasm the area where the optic nerves from the right and left eyes cross near the pituitary gland
bitot s spots are the buildup of keratin located superficially in the conjunctiva which are oval triangular or irregular in shape these spots are a sign of vitamin a deficiency and are associated with conjunctival xerosis in 1863 pierre bitot 1822 1888 a french physician first described these spots in ancient egypt this was treated with animal liver which is where vitamin a is stored
bitter pit is a disorder in apple fruits now believed to be induced by calcium deficiency it occurs less commonly in pears the disease was probably first reported in germany where it was known as stippen it was also known as baldwin spot and blotchy cork in north america the name bitter pit was first used by cobb in australia in 1895 the disease has been shown as non pathological and is now known as a disorder when it occurs on the tree it is known as tree pit it may also occur in storage when it is known as storage pit
a bjerrum defect is a crystallographic defect which is specific to ice and which is partly responsible for the electrical properties of ice it was first proposed by niels bjerrum in 1952 in order to explain the electrical polarization of ice in an electric field a hydrogen bond normally has one proton but a hydrogen bond with a bjerrum defect will have either two protons d defect or no proton l defect the unfavorable defect strain is resolved when a water molecule pivots about an oxygen atom to produce hydrogen bonds with single protons dislocations of ice ih along a slip plane create pairs of bjerrum defects one d defect and one l defect nonpolar molecules such as methane can form clathrate hydrates with water especially under high pressure although there is no hydrogen bonding of water molecules when methane is the guest molecule of the clathrate guest host hydrogen bonding often forms with guest molecules in clathrates of many larger organic molecules such as pinacolone and tetrahydrofuran in such cases the guest host hydrogen bonds result in the formation of l type bjerrum defect in the clathrate lattice oxygen atoms in alcohol or carbonyl functional groups and nitrogen atoms in amine functional groups in the guest molecules lead to transient hydrogen bonds and misoriented water molecules in the hydrate lattice
björnstad syndrome is an autosomal recessive congenital condition involving pili torti and nerve deafness and hair abnormalities it was first characterized in 1965 in oslo by prof roar theodor bjørnstad 1908 – 2002 it has been mapped to bcs 1 l hearing dissabilities related to björnstad syndrome are congenital and the severity of the deafness varies from person to person pili torti is recognized in early childhood and is characterised by twisted hair shafts and brittle hair
black band disease is a disease when corals develop a black band it is characterized by complete tissue degradation due to a pathogenic microbial consortium the mat is present between apparently healthy coral tissue and freshly exposed coral skeleton
black dog syndrome or big black dog syndrome is a disputed phenomenon in which black dogs are passed over for adoption in favor of lighter colored animals animal shelters often use the term bbd or big black dog to describe the type of larger dark colored mixed breed said to be typically passed over by adopters
the black drop effect is an optical phenomenon visible during a transit of venus and to a lesser extent a transit of mercury
a black eye periorbital hematoma or shiner is bruising around the eye commonly due to an injury to the face rather than to the eye the name is given due to the color of bruising the so called black eye is caused by bleeding beneath the skin and around the eye sometimes a black eye could get worse if not referring to a doctor after a few months indicating a more extensive injury even a skull fracture particularly if the area around both eyes is bruised raccoon eyes or if there has been a prior head injury although most black eye injuries are not serious bleeding within the eye called a hyphema is serious and can reduce vision and damage the cornea in some cases abnormally high pressure inside the eyeball ocular hypertension can also result
black foot disease is a grapevine trunk disease it is caused by fungi in the genus cylindrocarpon c fasciculare c pseudofasciculare c destructans c macrodidymum and c obtusisporum occurrence of grapevine trunk disease pathogens in rootstock mother plants in south africa
black gill disease is a disease of crustaceans
black hairy tongue bht also termed lingua villosa nigra refers to a condition of the tongue where the filiform papillae elongate with black or brown discoloration giving a black and hairy appearance the appearance may be alarming but it is a harmless condition predisposing factors include smoking xerostomia dry mouth soft diet poor oral hygiene and certain medications management is by improving oral hygiene especially scraping or brushing the tongue
black heel and palm also known as calcaneal petechiae chromidrose plantaire post traumatic punctate intraepidermal hemorrhage tache noir and talon noir is a skin condition characterized by a sudden shower of minute black punctate macules occurring most often on the posterior edge of the plantar surface of one or both heels
the black hole information paradox is a puzzle resulting from the combination of quantum mechanics and general relativity calculations suggest that physical information could permanently disappear in a black hole allowing many physical states to devolve into the same state this is controversial because it violates a commonly assumed tenet of science — that in principle complete information about a physical system at one point in time should determine its state at any other time a fundamental postulate of quantum mechanics is that complete information about a system is encoded in its wave function up to when the wave function collapses the evolution of the wave function is determined by a unitary operator and unitarity implies that information is conserved in the quantum sense
black leaf is a physiological plant disorder that affects some grape varieties such as concord it is essentially a potassium deficiency that causes the leaves on a vine to turn purple and eventually black as chlorophyll is lost for wine growers this lack of chlorophyll inhibits the vine s ability to transmit sugar to the grape leaving the resulting grapes with a low brix count that may be less than ideal for wine making
black piedra is a form of piedra caused by piedraia hortae terbinafine has been used in the treatment
black point kernel smudge or just smudge is a fungal disease that affects wheat barley and rye it is caused by various species of alternaria fusarium and helminthosporium and possibly other fungal genera the fungus forms after the seeds have set but while they are still green and it is potentiated by high humidity infected areas are brown to black in color and as the disease spreads the kernels may become shriveled occasionally the infected areas have a reddish tinge some authorities make a distinction between black point and smudge for them the disease is black point from initial infection until more than half of the kernel is infected or when the disease has entered into the seed s crease
black pox is a symptom of smallpox that is caused by bleeding under the skin which makes the skin look charred or black it was more common in adults this symptom usually indicates that a patient with smallpox is going to die a doctor who encountered black pox stated that doctors separate black pox into two forms — flat smallpox and hemorrhagic smallpox in a case of flat smallpox the skin remains smooth and doesn t pustulate but it darkens until it looks charred and it can slip or fall off the body in sheets sometimes all of it causing instant death though that is very rare in hemorrhagic smallpox black unclotted blood oozes or runs from the mouth and other body orifices black pox is close to one hundred percent fatal if any sign of it appears in the body the victim will almost certainly die in the hemorrhagic cases the virus destroys the linings of the throat the stomach the intestines the rectum and the vagina and these membranes disintegrate fatal smallpox can destroy the body s entire skin — both the exterior skin and the interior skin that lines the passages of the body
grape black rot is a fungal disease caused by an ascomycetous fungus guignardia bidwellii that attacks grape vines during hot and humid weather “ grape black rot originated in eastern north america but now occurs in portions of europe south america and asia it can cause complete crop loss in warm humid climates but is virtually unknown in regions with arid summers ” 4 the name comes from the black fringe that borders growing brown patches on the leaves the disease also attacks other parts of the plant “ all green parts of the vine the shoots leaf and fruit stems tendrils and fruit the most damaging effect is to the fruit ” 3 grape black rot affects many grape growers throughout the united states therefore it is important to understand the disease life cycle and environmental conditions to best manage the disease once infection takes place different methods are available to control the disease
black sigatoka is a leaf spot disease of banana plants caused by the ascomycete fungus mycosphaerella fijiensis morelet also known as black leaf streak it was discovered in 1963 and named for its similarities with the yellow sigatoka which is caused by mycosphaerella musicola mulder which was itself named after the sigatoka valley in fiji where an outbreak of this disease reached epidemic proportions from 1912 to 1923 according to new terminology the sigatoka disease complex is a cluster of three closely related fungi yellow sigatoka pseudocercospora musae eumusae leaf spot pseudocercospora eumusae and black sigatoka pseudocercospora fijiensis plants with leaves damaged by the disease may have up to 50 lower yield of fruit and control can take up to 50 sprays a year
blackheart is a non parasitic disease of the fruit of cultivated plants such as tomatoes that causes them to rot from the inside external signs of the disease may or may not be present the internal blackening develops in plants exposed to environmental pathology such as drought conditions or poor soil
blackleg black quarter quarter evil or quarter ill latin gangraena emphysematosa is an infectious bacterial disease most commonly caused by clostridium chauvoei a gram positive bacterial species it is seen in livestock all over the world usually affecting cattle sheep and goats it has been seen occasionally in farmed bison and deer the acute nature of the disease makes successful treatment difficult but an effective vaccine is available to provide animals with protective immunity
blackleg is a plant disease of potato caused by pectolytic bacteria that can result in stunting wilting chlorosis of leaves necrosis of several tissues a decline in yield and at times the death of the potato plant the term “ blackleg ” originates from the typical blackening and decay of the lower stem portion or “ leg of the plant blackleg in potatoes is most commonly caused by pectobacterium atrosepticum older synonym erwinia carotovora subsp astroseptica a gram negative nonsporulating facultative anaerobe that is also associated with soft rot of potatoes while other bacterial species such as pectobacterium carotovorum and dickeya dadantii can exhibit symptoms similar to blackleg of potato these pathogens exhibit broader host ranges are present in different climates and typically are more associated with soft rot diseases
a drug related blackout is a phenomenon caused by the intake of any substance or medication in which short term and long term memory creation is impaired therefore causing a complete inability to recall the past blackouts can be caused by any substance but are most frequently associated with gabaergic drugs blackouts are frequently described as having effects similar to that of anterograde amnesia in which the subject cannot recall any events after the event that caused amnesia research on alcohol blackouts was begun by e m jellinek in the 1940 s using data from a survey of alcoholics anonymous aa members he came to believe that blackouts would be a good determinant of alcoholism however there are conflicting views whether this is true the negative psychological effects of an alcohol related blackout are often worsened by those who suffer from anxiety disorders impairment of the liver will also allow more alcohol to reach the brain and hasten the individual s blackout the term blackout can also refer to a complete loss of consciousness or syncope diabetes cause it sometimes also
blackwater fever is a complication of malaria infection in which rbcs burst in the bloodstream hemolysis releasing hemoglobin directly into the blood vessels and into the urine frequently leading to kidney failure the disease was first linked to malaria by the sierra leonean physician dr john farrell easmon in his 1884 pamphlet entitled the nature and treatment of blackwater fever easmon coined the name blackwater fever and was the first to successfully treat such cases following the publication of his pamphlet
bladder augmentation is a surgical alteration of the urinary bladder it involves removing strips of tissue from the intestinal tract and adding this to the tissue of the bladder this has two intended results increased bladder volume and a reduced percentage of the bladder involved in contraction that in turn results in lower internal pressures in the bladder during urination risks of bladder augmentation include incomplete voiding of the bladder post surgery resulting in the patient having to undergo intermittent catheterisation or an indwelling catheter acute intestinal obstruction due to adhesions some years after surgery and in extremely rare cases cancers of the intestinal tissue within the bladder
bladder cancer is any of several types of cancer arising from the epithelial lining i e the urothelium of the urinary bladder rarely the bladder is involved by non epithelial cancers such as lymphoma or sarcoma but these are not ordinarily included in the colloquial term bladder cancer it is a disease in which abnormal cells multiply without control in the bladder the most common type of bladder cancer recapitulates the normal histology of the urothelium and is known as transitional cell carcinoma or more properly urothelial cell carcinoma five year survival rates in the united states are around 77 bladder cancer is the 9 th leading cause of cancer with 430 000 new cases and 165 000 deaths occurring in 2012
bladder cancer in cats and dogs usually is transitional cell carcinoma tcc which arises from the epithelial cells that line the bladder less often in these animals cancer of the urinary bladder is squamous cell carcinoma adenocarcinoma or rhabdomyosarcoma
bladder exstrophy also known as ectopia vesicae is a congenital anomaly that exists along the spectrum of the exstrophy epispadias complex and most notably involves protrusion of the urinary bladder through a defect in the abdominal wall its presentation is variable often including abnormalities of the bony pelvis pelvic floor and genitalia the underlying embryologic mechanism leading to bladder exstrophy is unknown though it is thought to be in part due to failed reinforcement of the cloacal membrane by underlying mesoderm
bladder outlet obstruction or boo is a urological condition where the urine flow from the urinary bladder through the urethra is impeded
bladder sphincter dyssynergia also known as detrusor sphincter dysynergia dsd the ics standard terminology agreed 1998 and neurogenic detrusor overactivity ndo is a consequence of a neurological pathology such as spinal injury or multiple sclerosis which disrupts central nervous system regulation of the micturition urination reflex resulting in dyscoordination of the detrusor muscles of the bladder and the male or female external urethral sphincter muscles in normal lower urinary tract function these two separate muscle structures act in synergistic coordination but in this neurogenic disorder the urethral sphincter muscle instead of relaxing completely during voiding dyssynergically contracts causing the flow to be interrupted and the bladder pressure to rise
a bladder stone is a stone found in the urinary bladder
blain was an animal disease of unknown etiology that was well known in the eighteenth and nineteenth centuries it is unclear whether it is still extant or what modern disease it corresponds to according to ephraim chambers eighteenth century cyclopaedia or an universal dictionary of arts and sciences blain was a distemper in the archaic eighteenth century sense of the word meaning disease occurring in animals consisting in a bladder growing on the root of the tongue against the wind pipe which at length swelling stops the wind it was thought to occur by great chafing and heating of the stomach blain is also mentioned in cattle their breeds management and diseases published in 1836 where it is also identified as gloss anthrax w c spooner s 1888 book the history structure economy and diseases of the sheep also identifies blain as being the same as gloss anthrax modern scholarship suggests that gloss anthrax was not the same disease as modern day anthrax but instead could have been foot and mouth disease or a viral infection with a secondary fusobacterium necrophorum infection it has also been suggested that it may have been due to a variant strain of true anthrax that is no longer in existence other sources also report epizootics known as blain or black blain in the 13 th and 14 th centuries but it is not clear if the disease involved was the same as gloss anthrax
the blaise ketone synthesis named after edmond e blaise is the chemical reaction of acid chlorides with organozinc compounds to give ketones the blaise ketone synthesis the reaction also works with organocuprates reviews have been written
the blaise reaction is an organic reaction that forms a β ketoester from the reaction of zinc metal with a α bromoester and a nitrile the reaction was first reported by edmond blaise 1872 1939 in 1901 the final intermediate is a metaloimine which is then hydrolyzed to give the desired β ketoester the blaise reaction bulky aliphatic esters tend to give higher yields steven hannick and yoshito kishi have developed an improved procedure it has been noted that free hydroxyl groups can be tolerated in the course of this reaction which is surprising for reactions of organometallic halides
the blanc chloromethylation also called the blanc reaction is the chemical reaction of aromatic rings with formaldehyde and hydrogen chloride catalyzed by zinc chloride or other lewis acid to form chloromethyl arenes the reaction was discovered by gustave louis blanc 1872 1927 in 1923 the reaction is performed with care as like most chloromethylation reactions it produces highly carcinogenic bis chloromethyl ether as a by product the blanc chloromethylation
in complex analysis the blaschke product is a bounded analytic function in the open unit disc constructed to have zeros at a finite or infinite sequence of prescribed complex numbers a 0 a 1 inside the unit disc blaschke products were introduced by wilhelm blaschke they are related to hardy spaces
a blast injury is a complex type of physical trauma resulting from direct or indirect exposure to an explosion blast injuries occur with the detonation of high order explosives as well as the deflagration of low order explosives these injuries are compounded when the explosion occurs in a confined space
a blast wave in fluid dynamics is the pressure and flow resulting from the deposition of a large amount of energy in a small very localised volume the flow field can be approximated as a lead shock wave followed by a self similar subsonic flow field in simpler terms a blast wave is an area of pressure expanding supersonically outward from an explosive core it has a leading shock front of compressed gases the blast wave is followed by a blast wind of negative pressure which sucks items back in towards the center the blast wave is harmful especially when one is very close to the center or at a location of constructive interference high explosives which detonate generate blast waves
blastic nk cell lymphoma is a type of lymphoma it is a cutaneous condition characterized by multiple rapidly expanding plaques it is positive for cd 4 and cd 56 it does not appear to be associated with epstein – barr virus
blastocystosis refers to a medical condition caused by infection with blastocystis blastocystis is a protozoal single celled parasite that inhabits the gastrointestinal tracts of humans and other animals many different types of blastocystis exist and they can infect humans farm animals birds rodents amphibians reptiles fish and even cockroaches
a blastoma is a type of cancer more common in children that is caused by malignancies in precursor cells often called blasts examples are nephroblastoma medulloblastoma and retinoblastoma the suffix blastoma is used to imply a tumor of primitive incompletely differentiated or precursor cells e g chondroblastoma is composed of cells resembling the precursor of chondrocytes blastomas usually occur in children
blastomycosis also known as north american blastomycosis blastomycetic dermatitis and gilchrist s disease is a fungal infection of humans and other animals notably dogs and occasionally cats caused by the organism blastomyces dermatitidis endemic to portions of north america blastomycosis causes clinical symptoms similar to histoplasmosis the disease occurs in several endemic areas the most important of which is in eastern north america particularly in the western and northern periphery of the great lakes basin extending eastward along the south shore of the st lawrence river valley and southward in the territory spanned by the central appalachian mountains in the east to the mississippi river valley in the west sporadic cases have been reported in continental africa the arabian peninsula and the indian subcontinent
blastomycosis like pyoderma also known as pyoderma vegetans is a cutaneous condition characterized by larger verrucous plaques with elevated borders and multiple pustules occurring
in 1985 edward blau a pediatrician in marshfield wisconsin reported a family that over four generations had granulomatous inflammation of the skin eyes and joints the condition was transmitted as an autosomal dominant trait in the same year jabs et al reported a family that over two generations had granulomatous synovitis uveitis and cranial neuropathies the condition was transmitted in an autosomal dominant fashion in 1981 malleson et al reported a family that had autosomal dominant synovitis camptodactyly and iridocyclitis one member died of granulomatous arteritis of the heart and aorta in 1982 rotenstein reported a family with granulomatous arteritis rash iritis and arthritis transmitted as an autosomal dominant trait over three generations then in 1990 pastores et al reported a kindred with a phenotype very similar to what blau described and suggested that the condition be called blau syndrome bs they also pointed out the similarities in the families noted above to bs but also pointed out the significant differences in the phenotypes in 1996 tromp et al conducted a genome wide search using affected and non affected members of the original family a marker d 16 s 298 gave a maximum lod score of 3 75 and put the bs susceptibility locus within the 16 p 12 q 21 interval hugot et al found a susceptibility locus for crohn disease a granulomatous inflammation of the bowel on chromosome 16 close to the locus for bs based on the above information blau suggested in 1998 that the genetic defect in bs and crohn disease might be the same or similar finally in 2001 miceli richard et al found the defect in bs to be in the nucleotide binding domain of card 15 nod 2 they commented in their article that mutations in card 15 had also been found in crohn disease confirmation of the defect in bs being in the card 15 gene was made by wang et al in 2002 using the bs family and others with that information the diagnosis of bs was not only determined by phenotype but now by genotype early onset sarcoidosis is bs without a family history bs has been diagnosed in patients who have not only the classic triad but granuloma in multiple organs treatment has included the usual anti inflammatory drugs such as adrenal glucocorticoids anti metabolites and also biological agents such as anti tnf and infliximab all with varying degrees of success the elucidation that the gene defect in bs involves the card 15 nod 2 gene has stimulated many investigators to define how this gene operates as part of the innate immune system that responds to bacterial polysaccharides such as muramyl dipeptide to induce signaling pathways that induce cytokine responses that protect the organism in bs the genetic defect seems to lead to over expression and poor control of the inflammatory response leading to widespread granulomatous inflammation and tissue damage this reference provides an excellent review of not only the clinical aspects of bs but also the presumed pathogenetic mechanisms brought about by the gene defect unanswered questions are what is the stimulus that activates the aberrant immune response and if found could more precise therapy be used and what is the relationship to the specific gene defect and the phenotype list of cutaneous conditions
bleach bypass also known as skip bleach or silver retention is an optical effect which entails either the partial or complete skipping of the bleaching function during the processing of a color film by doing this the silver is retained in the emulsion along with the color dyes the result is a black and white image over a color image the images usually have reduced saturation and exposure latitude along with increased contrast and graininess it usually is used to maximum effect in conjunction with a one stop underexposure
in cell biology a bleb is a bulge or protrusion of the plasma membrane of a cell human bioparticulate or abscess with an internal environment similar to that of a simple cell characterized by a spherical bulky morphology it is characterized by the decoupling of the cytoskeleton from the plasma membrane degrading the internal structure of the cell allowing the flexibility required to allow the cell to separate into individual bulges or pockets of the intercellular matrix most commonly blebs are seen in apoptosis programmed cell death but are also seen in other non apoptotic functions blebbing or zeiosis is the formation of blebs
in medicine a bleb is a blister often hemispherical filled with serous fluid blebs can form in a number of tissues due to different pathologies including frostbitten tissues and as a cause of spontaneous pneumothorax in ophthalmology blebs may be formed intentionally in the treatment of glaucoma in such treatments functional blebs facilitate the circulation of aqueous humor the blockage of which will lead to increase in eye pressure use of collagen matrix wound modulation device such as ologen during glaucoma surgery is known to produce vascular and functional blebs which are positively correlated with treatment success rate in the lungs a bleb is a collection of air within the layers of the visceral pleura in breasts a bleb is a milk blister also known as blocked nipple pore nipple blister or “ milk under the skin ”
bleeding also known as hemorrhaging or haemorrhaging is blood escaping from the circulatory system bleeding can occur internally where blood leaks from blood vessels inside the body or externally either through a natural opening such as the mouth nose ear urethra vagina or anus or through a break in the skin hypovolemia is a massive decrease in blood volume and death by excessive loss of blood is referred to as exsanguination typically a healthy person can endure a loss of 10 – 15 of the total blood volume without serious medical difficulties by comparison blood donation typically takes 8 – 10 of the donor s blood volume the stopping or controlling of bleeding is called hemostasis and is an important part of both first aid and surgery
in medicine hematology bleeding diathesis h a emorrhagic diathesis is an unusual susceptibility to bleed hemorrhage mostly due to hypocoagulability in turn caused by a coagulopathy a defect in the system of coagulation several types are distinguished ranging from mild to lethal also bleeding diathesis can be caused by thinning of the skin or impaired wound healing
blepharitis blɛfərˈaɪtᵻs blef ər eye tis is a common eye condition characterized by chronic inflammation of the eyelid usually where eyelashes grow resulting in inflamed irritated itchy and reddened eyelids a number of diseases and conditions can lead to blepharitis it can be caused by the oil glands at the base of the eyelashes becoming clogged a bacterial infection allergies or other conditions the severity and course can vary onset can be acute resolving without treatment within 2 – 4 weeks this can be greatly reduced with lid hygiene but more generally is a long standing chronic inflammation of varying severity it may be classified as seborrhoeic staphylococcal mixed posterior or meibomitis or parasitic it usually does not cause permanent damage
blepharochalasis is an inflammation of the eyelid that is characterized by exacerbations and remissions of eyelid edema which results in a stretching and subsequent atrophy of the eyelid tissue leading to the formation of redundant folds over the lid margins it typically affects only the upper eyelids and may be unilateral as well as bilateral
blepharophimosis is a condition where the patient has bilateral ptosis with reduced lid size vertically and horizontally the nasal bridge is flat and there is hypoplastic orbital rim both the vertical and horizontal palpebral fissures eyelid opening are shortened vignes 1889 probably first described this entity a dysplasia of the eyelids
blepharophimosis ptosis epicanthus inversus syndrome or bpes is a rare disease characterized by the conditions it is named after blepharophimosis ptosis and epicanthus inversus
blepharophyma is chronic swelling of eyelids mainly due to sebaceous gland hyperplasia
blepharospasm is any abnormal contraction or twitch of the eyelid in most cases symptoms last for a few days then disappear without treatment but sometimes the twitching is chronic and persistent causing lifelong challenges in those rare cases the symptoms are often severe enough to result in functional blindness the person s eyelids feel like they are clamping shut and will not open without great effort people have normal eyes but for periods of time are effectively blind due to their inability to open their eyelids in contrast the reflex blepharospasm is due to any pain in and around the eye it is of two types essential and reflex blepharospasm the benign essential blepharospasm is a focal dystonia — a neurological movement disorder involving involuntary and sustained contractions of the muscles around the eyes the term essential indicates that the cause is unknown but fatigue stress or an irritant are possible contributing factors although there is no cure botulinum toxin injections may help temporarily a surgical procedure known as myectomy may also be useful it is a fairly rare disease affecting only one in every 20 000 people in the united states the word is from greek βλέφαρον blepharon eyelid and σπασμός spasmos spasm an uncontrolled muscle contraction
blind loop syndrome bls commonly referred to in the literature as small intestinal bacterial overgrowth sibo or bacterial overgrowth syndrome bos is a state that occurs when the normal bacterial flora of the small intestine proliferates to numbers that cause significant derangement to the normal physiological processes of digestion and absorption in some cases of blind loop syndrome overgrowth of pathogenic non commensal bacteria has also been noted it has long been understood that from birth and throughout life large amounts of bacteria reside symbiotically within animal gastrointestinal tracts such as the human gastrointestinal tract the understanding of this gut flora has even led to novel treatments for bowel irregularity that utilize so called probiotics or good bacteria that aid in normal digestion the problem of bls arises when the bacterial colonies residing in the upper gastrointestinal tract begin to grow out of control or are altered in their makeup thereby creating a burden on the normal physiological processes occurring in the small intestine this results in problems inclusive of but not restricted to vitamin b 12 deficiency fat malabsorption and steatorrhea fat soluble vitamin deficiencies and intestinal wall injury
blind signal separation also known as blind source separation is the separation of a set of source signals from a set of mixed signals without the aid of information or with very little information about the source signals or the mixing process this problem is in general highly underdetermined but useful solutions can be derived under a surprising variety of conditions much of the early literature in this field focuses on the separation of temporal signals such as audio however blind signal separation is now routinely performed on multidimensional data such as images and tensors which may involve no time dimension whatsoever
blindsight is the ability of people who are cortically blind due to lesions in their striate cortex also known as primary visual cortex or v 1 to respond to visual stimuli that they do not consciously see the majority of studies on blindsight are conducted on patients who have the blindness on only one side of their visual field following the destruction of the striate cortex patients are asked to detect localize and discriminate amongst visual stimuli that are presented to their blind side often in a forced response or guessing situation even though they don t consciously recognise the visual stimulus research shows that blind patients achieve a higher accuracy than would be expected from chance alone type 1 blindsight is the term given to this ability to guess — at levels significantly above chance — aspects of a visual stimulus such as location or type of movement without any conscious awareness of any stimuli type 2 blindsight occurs when patients claim to have a feeling that there has been a change within their blind area — e g movement — but that it was not a visual percept blindsight challenges the common belief that perceptions must enter consciousness to affect our behavior it shows that our behavior can be guided by sensory information of which we have no conscious awareness it may be thought of as a converse of the form of anosognosia known as anton – babinski syndrome in which there is full cortical blindness along with the confabulation of visual experience
in the formulation of food products the bliss point is the amount of an ingredient such as salt sugar or fat which optimizes palatability pioneering work on the bliss point was carried out by american market researcher and psychophysicist howard moskowitz known for his successful work in product creation and optimization for foods ranging from spaghetti sauce to soft drinks moskowitz describes the bliss point as that sensory profile where you like food the most the bliss point for salt sugar or fat is a range within which perception is that there is neither too much nor too little but the just right amount of saltiness sweetness or richness the human body has evolved to favor foods delivering these tastes the brain responds with a reward in the form of a jolt of endorphins remembers what we did to get that reward and makes us want to do it again an effect run by the neurotransmitter dopamine combinations of sugar fat and salt act synergistically and are more rewarding than any one alone in food product optimization the goal is to include two or three of these nutrients at their bliss point
a blister is a small pocket of lymph within the upper layers of the skin typically caused by forceful rubbing friction burning freezing chemical exposure or infection most blisters are filled with a clear fluid either serum or plasma however blisters can be filled with blood known as blood blisters or with pus if they become infected the word blister entered english in the 14 th century it came from the middle dutch bluyster and was a modification of the old french blostre which meant a leprous nodule — a rise in the skin due to leprosy in dermatology today the words vesicle and bulla refer to blisters of smaller or greater size respectively
blister beetle dermatitis is a cutaneous condition that occurs after contact with any of several types of beetles including those from the meloidae and oedemeridae families blister beetles secrete an irritant called cantharidin a vesicant that can get onto humans if they touch the beetles the term blister beetle dermatitis is also occasionally and inappropriately used as a synonym for paederus dermatitis a somewhat different dermatitis caused by contact with pederin an irritant in the hemolymph of a different group of beetles the rove beetles
blistering distal dactylitis is a cutaneous condition characterized by tense superficial bullae occurring on a tender erythematous base over the volar fat pad of the phalanx of a finger or thumb
bloch oscillation is a phenomenon from solid state physics it describes the oscillation of a particle e g an electron confined in a periodic potential when a constant force is acting on it it was first pointed out by bloch and zener while studying the electrical properties of crystals in particular they predicted that the motion of electrons in a perfect crystal under the action of a constant electric field would be oscillatory instead of uniform while in natural crystals this phenomenon is extremely hard to observe due to the scattering of electrons by lattice defects it has been observed in semiconductor superlattices and in different physical systems such as cold atoms in an optical potential and ultrasmall josephson junctions
blocks in meteorology are large scale patterns in the atmospheric pressure field that are nearly stationary effectively “ blocking ” or redirecting migratory cyclones they are also known as blocking highs or blocking anticyclones these blocks can remain in place for several days or even weeks causing the areas affected by them to have the same kind of weather for an extended period of time e g precipitation for some areas clear skies for others in the northern hemisphere extended blocking occurs most frequently in the spring over the eastern pacific and atlantic oceans
in radio and wireless communications in general blocking is a condition in a receiver in which an off frequency signal generally further off frequency than the immediately adjacent channel causes the signal of interest to be suppressed blocking rejection is the ability of a receiver to tolerate an off frequency signal and avoid blocking a good automatic gain control design is part of achieving good blocking rejection
a blood blister is a type of blister that forms when subdermal tissues and blood vessels are damaged without piercing the skin it consists of a pool of lymph blood and other body fluids trapped beneath the skin if punctured it suppurates a dark fluid sometimes the fluids are cut off from the rest of the body and dry up leaving behind dead cell material inside the blister with a texture like putty some blood blisters can be extremely painful due to bruising where the blister occurred there are also blood blister like aneurysms as these are known to be located in the supraclinoid internal carotid artery and have been recognized as having unique pathological and clinical features
the blood hammer phenomenon is a sudden increase of the upstream blood pressure in a blood vessel especially artery or arteriole when the bloodstream is abruptly blocked by vessel obstruction the term blood hammer was introduced in cerebral hemodynamics by analogy with the hydraulic expression water hammer already used in vascular physiology to designate an arterial pulse variety the water hammer pulse complete understanding of the relationship between mechanical parameters in vascular occlusions is a critical issue which can play an important role in the future diagnosis understanding and treatment of vascular diseases
in medicine when referring to human feces blood in stool looks different depending on 1 how early it enters the intestines and thus how much digestive action it has been exposed to and on 2 how much there is a little bit more than a little or a lot this is why bright red blood in the stool has different clinical significance and a different name than brown or black blood in the stool thus the term can refer either to melena with more blackish appearance originating from upper gastrointestinal bleeding or to hematochezia with more red color originating from lower gastrointestinal bleeding the term blood in stool is usually not used to describe fecal occult blood which refers to blood that is not visible and thus is found only after chemical testing is performed in infants the apt test can be used to distinguish fetal hemoglobin from maternal blood
blood pressure bp is the pressure exerted by circulating blood upon the walls of blood vessels when used without further specification blood pressure usually refers to the arterial pressure in the systemic circulation blood pressure is usually expressed in terms of the systolic maximum pressure over diastolic minimum pressure and is measured in millimeters of mercury mmhg it is one of the vital signs along with respiratory rate heart rate oxygen saturation and body temperature normal resting systolic diastolic blood pressure in an adult is approximately 120 mmhg 80 mmhg abbreviated 120 80 mmhg blood pressure varies depending on situation activity and disease states it is regulated by the nervous and endocrine systems blood pressure that is low due to a disease state is called hypotension and pressure that is consistently high is hypertension both have many causes which can range from mild to severe both may be of sudden onset or of long duration long term hypertension is a risk factor for many diseases including heart disease stroke and kidney failure long term hypertension is more common than long term hypotension in western countries long term hypertension often goes undetected because of infrequent monitoring and the absence of symptoms
blood rain or red rain is a phenomenon in which blood is perceived to fall from the sky in the form of rain cases have been recorded since homer s iliad composed approximately 8 th century bc and are widespread before the 17 th century it was generally believed that the rain was actually blood literature mirrors cult practice in which the appearance of blood rain was considered a bad omen it was used as a tool foreshadowing events but while some of these may be literary devices some occurrences are historic there is now a scientific consensus that the blood rain phenomenon is caused by aerial spores of green microalgae trentepohlia annulata recorded instances of blood rain usually cover small areas the duration can vary sometimes lasting only a short time others several days by the 17 th century explanations for the phenomenon had moved away from the supernatural and attempted to provide natural reasons in the 19 th century blood rains were scientifically examined and theories that dust gave the water its red colour gained ground today the dominant theories are that the rain is caused by red dust suspended in the water rain dust or by the presence of micro organisms alternative explanations include sunspots and aurorae
blood squirt blood spurt blood spray blood gush or blood jet is the effect when an artery a blood vessel in the human body or other organism s body is cut blood pressure causes the blood to bleed out at a rapid intermittent rate in a spray or jet coinciding with the beating of the heart rather than the slower but steady flow of venous bleeding also known as arterial bleeding arterial spurting or arterial gushing the amount of blood loss can be copious occur very rapidly and can lead to death
blood stasis syndrome or blood stagnation chinese xue yu is an important underlying pathology of many disease processes according to traditional chinese medicine described in tcm theory as a slowing or pooling of the blood due to disruption of heart qi it is often understood in biomedical terms in terms of hematological disorders such as hemorrhage congestion thrombosis and local ischemia microclots and tissue changes
the blood sugar concentration or blood glucose level is the amount of glucose sugar present in the blood of a human or animal the body naturally tightly regulates blood glucose levels as a part of metabolic homeostasis with some exceptions glucose is the primary source of energy for the body s cells and blood lipids in the form of fats and oils are primarily a compact energy store glucose is transported from the intestines or liver to body cells via the bloodstream and is made available for cell absorption via the hormone insulin produced by the body primarily in the pancreas glucose levels are usually lowest in the morning before the first meal of the day termed the fasting level and rise after meals for an hour or two by a few millimolar blood sugar levels outside the normal range may be an indicator of a medical condition a persistently high level is referred to as hyperglycemia low levels are referred to as hypoglycemia diabetes mellitus is characterized by persistent hyperglycemia from any of several causes and is the most prominent disease related to failure of blood sugar regulation intake of alcohol causes an initial surge in blood sugar and later tends to cause levels to fall also certain drugs can increase or decrease glucose levels
bloom sometimes referred to as light bloom or glow is a computer graphics effect used in video games demos and high dynamic range rendering hdrr to reproduce an imaging artifact of real world cameras the effect produces fringes or feathers of light extending from the borders of bright areas in an image contributing to the illusion of an extremely bright light overwhelming the camera or eye capturing the scene
bloom syndrome often abbreviated as bs in literature also known as bloom torre machacek syndrome is a rare autosomal recessive disorder characterized by short stature predisposition to the development of cancer and genomic instability bs is caused by mutations in the blm gene leading to mutated dna helicase protein formation cells from a person with bloom syndrome exhibit a striking genomic instability that includes excessive crossovers between homologous chromosomes and sister chromatid exchanges sces the condition was discovered and first described by new york dermatologist dr david bloom in 1954
blount s disease is a growth disorder of the tibia shin bone that causes the lower leg to angle inward resembling a bowleg it is also known as tibia vara it is named after walter putnam blount 1900 – 1992 an american pediatric orthopedic surgeon it has also been known as mau nilsonne syndrome after c mau and h nilsonne who published early case reports of the condition
a blowout is a rapid loss of inflation pressure of a pneumatic tire leading to an explosion the primary cause for this is encountering an object that cuts or tears the structural components of the tire to the point where the structure is incapable of containing the pressurized air with the escaping pressurized air adding to further tear through the tire structure it is also fairly common for tread separations to be termed “ blowouts ” even those where the inflation pressure is not compromised because of this confusion the term is rarely used by experts in tire failures where the term impact damage is more frequently used tire blowouts have been a concern since the dawn of the motoring age first generation automotive tires suffered from frequent problems until technology developed
blue onion zwiebelmuster is a fine china tableware pattern for dishware originally manufactured by meissen porcelain since the 18 th century but copied by other companies since the late 19 th century as well
blue baby syndrome refers to at least two situations that lead to cyanosis in infants cyanotic heart disease and methemoglobinemia the most common cyanotic heart defects include transposition of the great arteries tetralogy of fallot persistent truncus arteriosus tricuspid atresia and total anomalous pulmonary venous return
blue balls is a slang term for the condition of temporary fluid congestion vasocongestion in the testicles accompanied by testicular pain caused by prolonged sexual arousal in the human male without ejaculation the term is thought to have originated in the united states first appearing in 1916 some urologists call the condition epididymal hypertension the condition is not experienced by all males
the blue bottle experiment is a chemical reaction an aqueous solution containing glucose sodium hydroxide methylene blue and some air is shaken in a closed bottle it turns from colorless to blue and then decolorizes again after a while with further shaking the cycle can be repeated several times this experiment is a classic chemistry demonstration and can be used in laboratory courses as a general chemistry experiment the reaction will work with other reducing sugars besides glucose and also with other reducing dyes the aqueous solution in the classical reaction contains glucose sodium hydroxide and methylene blue in the first step the enolate of glucose is formed the next step is a redox reaction of the enolate with methylene blue the glucose is oxidized to gluconic acid which in alkaline solution is in the sodium gluconate form methylene blue is reduced to colorless leucomethylene blue if there is enough available oxygen leucomethylene blue is then re oxidized to methylene blue and the blue color of the solution is restored the availability of oxygen is increased by shaking the solution when the solution comes to rest glucose reduction of the redox dye again takes the upper hand and the color of the solution disappears the reaction is first order in glucose methylene blue and hydroxide ion and zero order in oxygen other glucose oxidation products besides sodium gluconate that are reported are d arabino hexos 2 ulose glucosone the anion of d arabinonate after splitting of a formate anion and finally arabinonic acid
blue diaper syndrome is a rare autosomal recessive metabolic disorder characterized in infants by bluish urine stained diapers it is also known as drummond s syndrome and hypercalcemia it is caused by a defect in tryptophan absorption bacterial degradation of unabsorbed tryptophan in the intestine leads to excessive indole production and thus to indicanuria which on oxidation to indigo blue causes a peculiar bluish discoloration of the diaper indoluria symptoms typically include digestive disturbances fever and visual problems some may also develop disease due to the incomplete breakdown of tryptophan it was characterized in 1964 and is associated with the x linked sex gene since this syndrome is x linked the chance for a child to receive normal genes from both parents and be genetically normal for that particular trait is 25 if an individual receives one normal gene and one gene for the disease the person will be a carrier for the disease but usually will not show symptoms carrier females usually do not display symptoms of the disorder because it is usually the x chromosome with the abnormal gene that is “ turned off ” one can do genetic testing to see if their child will get this syndrome but most do not find out until they see the symptoms mentioned below
the blue field entoptic phenomenon or scheerer s phenomenon after the german ophthalmologist richard scheerer who first drew clinical attention to it in 1924 is the appearance of tiny bright dots nicknamed blue sky sprites moving quickly along squiggly lines in the visual field especially when looking into bright blue light such as the sky the dots are short lived visible for a second or less and traveling short distances along seemingly random curvy paths some of them follow the same path as predecessors the dots may be elongated along the path like tiny worms the speed of the dots varies in sync with the pulse they briefly accelerate at each heart beat the dots appear in the central field of view within 10 to 15 degrees from the fixation point the left and right eye see different dots someone looking with both eyes sees a mixture most people are able to see this phenomenon in the sky although it is rather weak and many people do not notice it until asked to pay attention the dots are highly conspicuous against a monochromatic blue background 430 nm instead of the sky
blue mold is a downy mildew disease of tobacco that is caused by peronospora tabacina a fungus like protist in the family peronosporaceae blue mold can cause severe damage to susceptible tobacco plants in many parts of the world since it is an obligate parasite it must have living tobacco tissue in order to grow although tobacco remains the primary host for this disease other hosts including pepper plants and eggplants can also be reservoirs the term blue mold may also be applied to penicillium roqueforti a mold used in producing the taste and characteristic blue green inclusions in roquefort and other blue cheeses a powdery mildew disease of hops has sometimes been erroneously called blue mold it is caused by sphaerotheca humuli a fungus in the order erysiphales this hops disease became epidemic in the new york state hops industry in 1909 ultimately leading to the abandonment of the crop in the northeastern usa
blue nails or more formally azure lunula are characterized by a blue discoloration of the lunulae seen in argyria and cases of hepatolenticular degeneration wilson s disease also having been reported in hemoglobin m disease and hereditary acrolabial telangiectases in wilson s disease the blue color involves the lunula most intense pigmentation and fades proximally in argyria the nail is permanently pigmented a slate blue color and is most evident in the lunula minocycline and zidovudine can also turn the nail plate blue gray
blue nevus also known as blue neuronevus dermal melanocytoma and nevus bleu is a type of melanocytic nevus the blue colour is caused by the pigment being deeper in the skin than in ordinary nevi in principle they are harmless but they can sometimes be mimicked by malignant lesions i e some melanomas can look like a blue nevus
blue rubber bleb nevus syndrome or brbns or blue rubber bleb syndrome or blue rubber bleb nevus or bean syndrome is a rare disorder that consists mainly of abnormal blood vessels affecting the gastrointestinal tract it was characterized by william bean in 1958 brbns is caused by somatic mutations in the tek tie 2 gene
blueberry muffin baby is the characteristic distributed purpura occurring as a result of extramedullary hematopoiesis found in infants the purpura are often generalized but occur more often on the trunk head and neck the name is from the superficial similarity to a blueberry muffin
blueberry shoestring virus bbssv is a viral disease that is commonly transmitted by the aphid vector illinoia pepperi the blueberry shoestring virus disease is very prominent in highbush and lowbush blueberry plants in the northeastern and upper midwest of the united states symptoms can vary significantly depending on the environment but the most common disease symptoms are reddish streaking on young stems reduced vigor and strap shaped leaves the blueberry shoestring virus disease can be managed by eliminating the aphid vector through the use of biological chemical or cultural controls in severe cases the disease leads to an extensive loss of yield and marketable fruit
bluetongue disease is a non contagious insect borne viral disease of ruminants mainly sheep and less frequently cattle goats buffalo deer dromedaries and antelope it is caused by the bluetongue virus btv the virus is transmitted by the midge culicoides imicola culicoides variipennis and other culicoids
blunt trauma blunt injury non penetrating trauma or blunt force trauma refers to physical trauma to a body part either by impact injury or physical attack the latter is usually referred to as blunt force trauma the term refers to the initial trauma from which develops more specific types such as contusions abrasions lacerations and or bone fractures blunt trauma is contrasted with penetrating trauma in which an object such as a bullet enters the body
blurred vision is an ocular symptom
boanthropy is a psychological disorder in which a human believes himself or herself to be a bovine
bob bellemore is a known presence in rhode island s ice hockey and baseball communities he is a former standout goaltender and baseball player for providence college in the national collegiate athletic association he has also served as the goaltending coach for the national hockey league s new jersey devils
bobble head doll syndrome is a rare neurological movement disorder in which patients usually children around age 3 begin to bob their head and shoulders forward and back or sometimes side to side involuntarily in a manner reminiscent of a bobblehead doll the syndrome is related to cystic lesions and swelling of the third ventricle in the brain symptoms of bobble head doll syndrome are diverse but can be grouped into two categories physical and neurological the most common form of treatment is surgical implanting of a shunt to relieve the swelling of the brain
boden s mate is a checkmating pattern in chess characterized by bishops on two criss crossing diagonals for example bishops on a 6 and f 4 delivering mate to a king on c 8 with possible flight squares for the king being occupied by friendly pieces most often the checkmated king has castled queenside and is mated on c 8 or c 1 many variants on the mate are seen for example a king on e 8 checkmated by bishops on g 6 and a 3 and a king on f 1 checkmated by bishops on h 3 and b 6 often the mate is immediately preceded by a sacrifice that opens up the diagonal on which the bishop delivers checkmate the mate is named for samuel boden who played a famous early example of it in schulder – boden london 1853 however it had been known previously from the game horwitz – popert hamburg 1844
the bodroux – chichibabin aldehyde synthesis is a chemical reaction whereby a grignard reagent is converted to an aldehyde one carbon longer bodroux chichibabin aldehyde synthesis reaction of a grignard reagent with triethyl orthoformate gives an acetal which can be hydrolyzed to an aldehyde for example the synthesis of n hexanal
body dysmorphic disorder bdd is a mental disorder characterized by an obsessive preoccupation that some aspect of one s own appearance is severely flawed and warrants exceptional measures to hide or fix it in bdd s delusional variant the flaw is imagined if the flaw is actual its importance is severely exaggerated either way one s thoughts about it are pervasive and intrusive occupying up to several hours a day the dsm 5 categorizes bdd in the obsessive – compulsive spectrum and distinguishes it from anorexia nervosa a fairly common mental disorder estimated to affect up to 2 4 of the population bdd usually starts during adolescence and affects men and women roughly equally the bdd subtype muscle dysmorphia perceiving the body as too small affects mostly males besides thinking about it one repetitively checks and compares the perceived flaw and can adopt unusual routines to avoid social contact that exposes it fearing the stigma of vanity one usually hides the preoccupation commonly unsuspected even by psychiatrists bdd has been greatly underdiagnosed severely impairing quality of life via educational and occupational dysfunction and social isolation bdd involves especially high rates of suicidal ideation and suicide attempts
body fat redistribution bfr syndrome sometimes called fat derangement is a medical condition characterized by fat loss or occasionally fat gain often in the cheeks or face bfr most often occurs in hiv aids patients undergoing antiretroviral therapy
body flex is a lack of rigidity in a motor vehicle s chassis it is often something to be avoided by car manufacturers as higher levels of body flex is a sign of structural weakness and means that the vehicle s suspension cannot work as efficiently the body takes up some of the slack rather than the parts of the car which were specifically designed for this purpose a chassis that flexes may be prone to fatigue and further softening with use will eventually result in failure cars of a sporting nature are therefore often very stiff while convertibles or cabriolets are not often considered to be good candidates for high performance sports cars because of their lack of a rigid roof although for some time body flex was a result of attempts to keep a car s weight down makers such as audi the a 8 and jaguar with the 2003 xj 8 have employed the use of aluminium in chassis production to get around this obstacle ensuring the weight of these cars and their level of body flex can both be kept to a minimum typically the stiffness of the body is measured in torsion the body is supported at the spring caps at the rear and then a torque is applied to the front spring caps via a long beam and a fulcrum values achieved range from 1 000 lb · ft 1 400 n · m per degree for pre war racing cars up to 25 000 lb · ft 33 900 n · m per degree for some modern production vehicles
body hopping is the fictional ability and desire to possess people in quick succession a body hopper can transfer quickly from one physical body to another physical body with little or no resistance and few conditions on moving on to a new body and usually without getting stuck in said body for a long period of time
body identification is a subfield of forensic science wherein investigators need to identify a body forensic literally for the courts purposes are served by rigorous scientific forensic identification techniques but these are generally preceded by simply asking bystanders or other persons for the victim s name if a body is not badly decomposed or damaged two persons or one who knew the deceased well should visually confirm the identity authorities will also compare supportive documents such as driver s license passport or other authoritative photo id before accepting a personal identification with which to further their investigative and or forensic purposes of course any formal investigation should reality check additional forensic and scientific evidence to reinforce or question the supposed identity of the victim reliable identification becomes increasingly difficult as time passes
body image is a person s perception of the aesthetics or sexual attractiveness of their own body the phrase body image was first coined by the austrian neurologist and psychoanalyst paul schilder in his book the image and appearance of the human body 1935 human society has at all times placed great value on beauty of the human body but a person s perception of their own body may not correspond to society s standards the concept of body image is used in a number of disciplines including psychology medicine psychiatry psychoanalysis philosophy and cultural and feminist studies the term is also often used in the media across these disciplines and media there is no consensus definition a person s body image is thought to be in part a product of their personal experiences personality and various social and cultural forces a person s sense of their own physical appearance usually in relation to others or in relation to some cultural ideal can shape their body image a person s perception of their appearance can be different from how others actually perceive them research suggests that exposure to mass media depicting the thin ideal body may be linked to body image disturbance in women this meta analysis examined experimental and correlational studies testing the links between media exposure to body dissatisfaction internalization of the thin ideal and eating behaviors and beliefs with a sample of 77 studies that yielded 141 effect sizes effects for some outcome variables were moderated by publication year and study design the findings support the notion that exposure to media images depicting the thin ideal body is related to body image concerns for women a 2007 report by the american psychological association found that a culture wide sexualization of girls and women was contributing to increased female anxiety associated with body image similar findings associated with body image were found by an australian government senate standing committee report on the sexualization of children in the media however other scholars have expressed concern that these claims are not based on solid data body image can have a wide range of psychological effects and physical effects throughout history it has been extremely difficult for people to live up to the standards of society and what they believe the ideal body is there are many factors that lead to a person ’ s body image some of these include family dynamics mental illness biological predispositions and environmental causes for obesity or malnutrition and cultural expectations e g media and politics people who are both underweight and overweight can have poor body image however because people are constantly told and shown the cosmetic appeal of weight loss and are warned about the risks of obesity those who are normal or overweight on the bmi scale have higher risks of poor body image this is something that can lead to a change in a person s body image often people who have a low body image will try to alter their bodies in some way such as by dieting or undergoing cosmetic surgery
body integrity identity disorder biid also referred to as amputee identity disorder is a psychological disorder in which an otherwise healthy individual feels that they are meant to be disabled transability an almost identical disorder is medically recognized by the american psychiatric association s dsm 5 but biid is not biid is related to xenomelia the dysphoric feeling that one or more limbs of one s body do not belong to one s self biid is typically accompanied by the desire to amputate one or more healthy limbs it also includes the desire for other forms of disability as in the case of a woman who intentionally blinded herself biid can be associated with apotemnophilia sexual arousal based on the image of one s self as an amputee the cause of biid is unknown one hypothesis states that it results from a neurological failing of the brain s inner body mapping function located in the right parietal lobe to incorporate the affected limb in its understanding of the body s physical form
body odor or bo is present in animals including humans and its intensity can be influenced by many factors behavioral patterns survival strategies body odor has a strong genetic basis both in animals and humans but it can be also strongly influenced by various diseases and psychological conditions body odor is generally considered to be an unpleasant odor among many human cultures
human body shape is a complex phenomenon with sophisticated detail and function the general shape or figure of a person is defined mainly by the molding of skeletal structures as well as the distribution of muscles and fat skeletal structure grows and changes only up to the point at which a human reaches adulthood and remains essentially the same for the rest of his or her life growth is usually completed between the ages of 13 and 18 at which time the epiphyseal plates of long bones close allowing no further growth see human skeleton
the body size species richness distribution is a pattern observed in the way taxa are distributed over large spatial scales the number of species that exhibit small body size generally far exceed the number of species that are large bodied macroecology has long sought to understand the mechanisms that underlie the patterns of biodiversity such as the body size species richness pattern this pattern was first observed by hutchinson and macarthur 1959 and it appears to apply equally well to a broad range of taxa from birds and mammals to insects bacteria may 1978 brown and nicoletto 1991 and deep sea gastropods mcclain 2004 nonetheless its ubiquity remains undecided most studies focus on the distribution of taxonomic fractions of largely non interacting species such as birds or mammals this article is primarily based on those data
bodybuilding supplements are dietary supplements specifically marketed to those involved in bodybuilding weightlifting and athletics among the most widely used are vitamins protein branched chain amino acids bcaa glutamine essential fatty acids meal replacement products creatine weight loss products and testosterone boosters supplements are sold either as single ingredient preparations or in the form of stacks proprietary blends of various supplements marketed as offering synergistic advantages while many bodybuilding supplements are also consumed by the general public their salience and frequency of use may differ when used specifically by bodybuilders they may be marketed as a product to replace meals enhance weight gain promote weight loss or improve athletic performance annual sales of sport nutrition products in the us is over 2 7 billion us according to consumer reports
boehm syndrome is a symptom specific map dot fingerprint dystrophy of the cornea the epithelium is separated from the stroma by a membrane in map dot fingerprint dystrophy this membrane develops abnormally exhibiting a map like appearance or perhaps opaque dots sometimes lines are formed that resemble small fingerprints in some cases this irregular structure can lead to painful epithelial erosions
boerenbont is a traditional pattern used on pottery from the netherlands translated from dutch boer means farmer and bont refers to a mixture of colors the distinctive floral pattern is hand painted with simple brush strokes of red yellow green and blue currently manufactured by royal boch in belgium the pattern originated as a local craft made by farmers ’ wives in the 19 th century according to the royal boch website a variety of patterns have followed the path of dutch merchants all over the world from sumatra to zanzibar via goa it remains a popular pattern today
esophageal rupture is a rupture of the esophageal wall iatrogenic causes account for approximately 56 of esophageal perforations usually due to medical instrumentation such as an endoscopy or paraesophageal surgery in contrast the term boerhaave s syndrome is reserved for the 10 of esophageal perforations which occur due to vomiting spontaneous perforation of the esophagus most commonly results from a full thickness tear in the esophageal wall due to a sudden increase in intraesophageal pressure combined with relatively negative intrathoracic pressure caused by straining or vomiting effort rupture of the esophagus or boerhaave s syndrome other causes of spontaneous perforation include caustic ingestion pill esophagitis barrett s esophagus infectious ulcers in patients with aids and following dilation of esophageal strictures in most cases of boerhaave s syndrome the tear occurs at the left postero lateral aspect of the distal esophagus and extends for several centimeters the condition is associated with high morbidity and mortality and is fatal without treatment the occasionally nonspecific nature of the symptoms may contribute to a delay in diagnosis and a poor outcome spontaneous effort rupture of the cervical esophagus leading to localized cervical perforation may be more common than previously recognized and has a generally benign course preexisting esophageal disease is not a prerequisite for esophageal perforation but it contributes to increased mortality this condition was first documented by the 18 th century physician herman boerhaave after whom it is named a related condition is mallory weiss syndrome which is only a mucosal tear in case of iatrogenic perforation common site is cervical esophagus just above the upper sphincter where as spontaneous rupture as seen in boerhaave s syndrome perforation commonly occurs in the lower 1 3 rd of esophagus
bogart – bacall syndrome bbs is a voice disorder that is caused by abuse or overuse of the vocal cords people who speak or sing outside their normal vocal range can develop bbs symptoms are chiefly an unnaturally deep or rough voice or dysphonia and vocal fatigue the people most commonly afflicted are those who speak in a low pitched voice particularly if they have poor breath and vocal control the syndrome can affect both men and women in 1988 an article was published describing a discrete type of vocal dysfunction which results in men sounding like humphrey bogart and women sounding like lauren bacall bbs is now the medical term for an ongoing hoarseness that often afflicts actors singers or tv radio voice workers who routinely speak in a very low pitch treatment usually involves voice therapy by a speech language pathologist
bogoliubov causality condition is a causality condition for scattering matrix s matrix in axiomatic quantum field theory the condition was introduced in axiomatic quantum field theory by nikolay bogolyubov in 1955
the bohr effect is a physiological phenomenon first described in 1904 by the danish physiologist christian bohr stating that haemoglobin s oxygen binding affinity see oxygen – haemoglobin dissociation curve is inversely related both to acidity and to the concentration of carbon dioxide that is an increase in blood co 2 concentration which leads to a decrease in blood ph will result in haemoglobin proteins releasing their load of oxygen conversely a decrease in carbon dioxide provokes an increase in ph which results in hemoglobin picking up more oxygen since carbon dioxide reacts with water to form carbonic acid an increase in co 2 results in a decrease in blood ph
bohring – opitz syndrome bos is a medical syndrome characterised by characteristic craniofacial appearance fixed contractures of the upper limbs abnormal posture feeding difficulties intellectual disability small size at birth and failure to thrive some of these features are shared with other genetic syndromes genetically de novo truncating mutations in asxl 1 have been shown to account for approximately 50 of bohring – opitz syndrome cases bohring opitz syndrome is an extremely rare genetic syndrome there are fewer than 60 cases in the world this syndrome is diagnosed by genetic testing and is a mutation in the asxl 1 gene the leading cause of death is respiratory infections children with bos can have feeding difficulties recurring respiratory infections sleep apnea developmental delay failure to thrive abnormal hair density and length wilm ’ s tumors brain abnormalities silent aspiration and the list goes on to find out more about bohring opitz syndrome please visit the website bohring opitz syndrome and www bos foundation org bohring – opitz syndrome is sometimes also called oberklaid – danks syndrome
a boil also called a furuncle is a deep folliculitis infection of the hair follicle it is most commonly caused by infection by the bacterium staphylococcus aureus resulting in a painful swollen area on the skin caused by an accumulation of pus and dead tissue boils which are expanded are basically pus filled nodules individual boils clustered together are called carbuncles most human infections are caused by coagulase positive s aureus strains notable for the bacteria s ability to produce coagulase an enzyme that can clot blood almost any organ system can be infected by s aureus
bolivian hemorrhagic fever bhf also known as black typhus or ordog fever is a hemorrhagic fever and zoonotic infectious disease originating in bolivia after infection by machupo virus bhf was first identified in 1963 as an ambisense rna virus of the arenaviridae family by a research group led by karl johnson the mortality rate is estimated at 5 to 30 percent due to its pathogenicity machupo virus requires biosafety level four conditions the highest level in february and march 2007 some 20 suspected bhf cases 3 fatal were reported to the el servicio departamental de salud sedes in beni department bolivia and in february 2008 at least 200 suspected new cases 12 fatal were reported to sedes in november 2011 a sedes expert involved in a serosurvey to determine the extent of machupo virus infections in the department after the discovery of a second confirmed case near the departmental capital of trinidad in november 2011 expressed concern about expansion of the virus distribution outside the endemic zone in mamoré and iténez provinces
bond softening is an effect of reducing the strength of a chemical bond by strong laser fields to make this effect significant the strength of the electric field in the laser light has to be comparable with the electric field the bonding electron feels from the nuclei of the molecule such fields are typically in the range of 1 – 10 v å which corresponds to laser intensities 1013 – 1015 w cm 2 nowadays these intensities are routinely achievable from table top ti sapphire lasers
a bone cyst or geode is a type of cyst that can present itself in the jaw or on other locations in the body types include unicameral bone cyst simple bone cyst aneurysmal bone cyst traumatic bone cyst
bone density or bone mineral density bmd is the amount of bone mineral in bone tissue the concept is of mass of mineral per volume of bone relating to density in the physics sense although clinically it is measured by proxy according to optical density per square centimeter of bone surface upon imaging bone density measurement is used in clinical medicine as an indirect indicator of osteoporosis and fracture risk it is measured by a procedure called densitometry often performed in the radiology or nuclear medicine departments of hospitals or clinics the measurement is painless and non invasive and involves low radiation exposure measurements are most commonly made over the lumbar spine and over the upper part of the hip the forearm may be scanned if the hip and lumbar spine are not accessible there is a statistical association between poor bone density and higher probability of fracture fractures of the legs and pelvis due to falls are a significant public health problem especially in elderly women leading to much medical cost inability to live independently and even risk of death bone density measurements are used to screen people for osteoporosis risk and to identify those who might benefit from measures to improve bone strength
bone disease refers to the medical conditions which affect the bone
a bone fracture sometimes abbreviated frx or fx fx or is a medical condition in which there is a damage in the continuity of the bone a bone fracture can be the result of high force impact or stress or a minimal trauma injury as a result of certain medical conditions that weaken the bones such as osteoporosis bone cancer or osteogenesis imperfecta where the fracture is then properly termed a pathologic fracture although broken bone and bone break are common colloquialisms for a bone fracture break is not a formal orthopedic term
bone marrow suppression or myelotoxicity adjective myelotoxic or myelosuppression is the decrease in production of cells responsible for providing immunity leukocytes carrying oxygen erythrocytes and or those responsible for normal blood clotting thrombocytes bone marrow suppression is a serious side effect of chemotherapy and certain drugs affecting the immune system such as azathioprine the risk is especially high in cytotoxic chemotherapy for leukemia non steroidal anti inflammatory drugs in some rare instances may also cause bone marrow suppression the decrease in blood cell counts does not occur right at the start of chemotherapy because the drugs do not destroy the cells already in the bloodstream these are not dividing rapidly instead the drugs affect new blood cells that are being made by the bone marrow when myelosuppression is severe it is called myeloablation because the bone marrow is the manufacturing center of blood cells the suppression of bone marrow activity causes a deficiency of blood cells this condition can rapidly lead to life threatening infection as the body cannot produce leukocytes in response to invading bacteria and viruses as well as leading to anaemia due to a lack of red blood cells and spontaneous severe bleeding due to deficiency of platelets parvovirus b 19 inhibits erythropoiesis by lytically infecting rbc precursors in the bone marrow and is associated with a number of different diseases ranging from benign to severe in immunocompromised patients b 19 infection may persist for months leading to chronic anemia with b 19 viremia due to chronic marrow suppression thiazide diuretics can also lead to bone marrow suppression as an adverse effect
bone pain also known medically by is pain coming from a bone it occurs as a result of a wide range of diseases and or physical conditions and may severely impair the quality of life for patients who suffer from it bone pain belongs to the class of deep somatic pain often experienced as a dull pain that cannot be localized accurately by the patient this is in contrast with the pain which is mediated by superficial receptors in e g the skin bone pain can have several possible causes ranging from extensive physical stress to serious diseases such as cancer for many years it has been known that bones are innervated with sensory neurons yet their exact anatomy remained obscure due to the contrasting physical properties of bone and neural tissue more recently it is becoming clear what types of nerves innervated which sections of bone the periosteal layer of bone tissue is highly pain sensitive and an important cause of pain in several disease conditions causing bone pain like fractures osteoarthritis etc however in certain diseases the endosteal and haversian nerve supply seems to play an important role e g in osteomalacia osteonecrosis and other bone diseases thus there are several types of bone pain each with many potential sources or origins of cause
bone resorption is resorption of bone tissue that is the process by which osteoclasts break down the tissue in bones and release the minerals resulting in a transfer of calcium from bone tissue to the blood the osteoclasts are multi nucleated cells that contain numerous mitochondria and lysosomes these are the cells responsible for the resorption of bone osteoclasts are generally present on the outer layer of bone just beneath the periosteum attachment of the osteoclast to the osteon begins the process the osteoclast then induces an infolding of its cell membrane and secretes collagenase and other enzymes important in the resorption process high levels of calcium magnesium phosphate and products of collagen will be released into the extracellular fluid as the osteoclasts tunnel into the mineralized bone osteoclasts are also prominent in the tissue destruction commonly found in psoriatic arthritis and other rheumatology related disorders the human body is in a constant state of bone remodeling bone remodelling is a process which maintains bone strength and ion homeostatis by replacing discrete parts of old bone with newly synthesized packets of proteinaceous matrix bone is resorbed by osteoclasts and is deposited by osteoblasts in a process called ossification osteocyte activity also plays a key role in this process conditions that result in a decrease in bone mass can either be caused by an increase in resorption or a decrease in ossification during childhood bone formation exceeds resorption but as the aging process occurs resorption exceeds formation bone resorption rates are much higher in post menopausal older women due to estrogen deficiency related with menopause common treatments include drugs that increase bone mineral density bisphosphonates rankl inhibitors serms — selective oestrogen receptor modulators hormone replacement therapy and calcitonin are some of the common treatments light weight bearing exercise also tends to eliminate the negative effects of bone resorption
bone spavin is a bony growth within the lower hock joint of horse or cattle it is caused by osteoarthritis and the degree of lameness that results can be serious enough to end a horse s competitive career
a bone tumor also spelled bone tumour is a neoplastic growth of tissue in bone abnormal growths found in the bone can be either benign noncancerous or malignant cancerous average five year survival in the united states after being diagnosed with bone and joint cancer is 67
bonnet – dechaume – blanc syndrome also known as wyburn mason syndrome is a rare congential arteriovenous malformation of the brain retina or facial nevi the syndrome has a number of possible symptoms and can affect the skin bones kidneys muscles and gastrointestinal tract when the syndrome affects the brain people can experience severe headaches seizures acute stroke meningism and progressive neurological deficits due to acute or chronic ischaemia caused by arteriovenous shunting as for the retina the syndrome causes retinocephalic vascular malformations that tend to be present with intracranial hemorrhage and lead to decreased visual acuity proptosis pupillary defects optic atrophy congestion of bulbar conjunctiva and visual field defects retinal lesions can be unilateral and tortuous and symptoms begin to appear in the second and third decades of life the syndrome can present cutaneous lesions or skin with different texture thickness and color usually on the face the facial features caused by the syndrome vary from slight discoloration to extensive nevi and angiomas of the skin in some cases the frontal and maxillary sinus can present problems in the subject due to the syndrome there have only been 52 reported cases of patients with bonnet – dechaume – blanc syndrome as of 2012 symptoms are rarely noticed in children and the syndrome is often diagnosed in late childhood or early adulthood when visual impairment is noticed fluorescein angiography is commonly used to diagnose the syndrome there have been several methods in treating patients who display bonnet – dechaume – blanc syndrome however which method seems to work the most is within argument patients with intracranial lesions have been treated with surgical intervention and in some cases this procedure has been successful other treatments include embolization radiation therapy and continued observation with limited research on bonnet – dechaume – blanc syndrome researchers have focused on the clinical and radiological findings rather than how to manage this rare and non heritable syndrome
in the physics of superfluidity a boojum is a geometric pattern on the surface of one of the phases of superfluid helium 3 whose motion can result in the decay of a supercurrent a boojum can result from a monopole singularity in the bulk of the liquid being drawn to and then pinned on a surface although superfluid helium 3 only exists within a few thousandths of a degree of absolute zero boojums have also been observed forming in various liquid crystals which exist at a far broader range of temperatures the boojum was named by david mermin of cornell university in 1976 he was inspired by lewis carroll s poem the hunting of the snark as in the poem the appearance of a boojum can cause something in this case the supercurrent to softly and suddenly vanish away other less whimsical names had already been suggested for the phenomenon but mermin was persistent after an exchange of letters that mermin describes as both lengthy and hilarious the editors of physical review letters agreed to his terminology research using the term boojum in a superfluid context was first published in 1977 and the term has since gained widespread acceptance in broader areas of physics its russian phonetic equivalent is budzhum which is also well accepted by physicists the plural of the term is boojums a word initially disliked by mermin who at first used booja but one which is defined unambiguously by carroll in his poem
book store shoplifting is a problem for book sellers and has sometimes led stores to keep certain volumes behind store counters shoplifters at book stores also known as book shops may be either amateur or professional thieves professionals target high priced books and books that are easily resold such as college textbooks in addition to shoplifting thievery also has been due to pilfering by shipping personnel and burglary book stores also are victimized by thefts of merchandise and other items aside from books at vroman s bookstore in pasadena california someone attempted to steal a security camera at the boulder bookshop in boulder colorado prints hung in the bathroom and plants have been stolen
a boolean valued function sometimes called a predicate or a proposition is a function of the type f x → b where x is an arbitrary set and where b is a boolean domain i e a generic two element set for example b 0 1 whose elements are interpreted as logical values for example 0 false and 1 true in the formal sciences mathematics mathematical logic statistics and their applied disciplines a boolean valued function may also be referred to as a characteristic function indicator function predicate or proposition in all of these uses it is understood that the various terms refer to a mathematical object and not the corresponding semiotic sign or syntactic expression in formal semantic theories of truth a truth predicate is a predicate on the sentences of a formal language interpreted for logic that formalizes the intuitive concept that is normally expressed by saying that a sentence is true a truth predicate may have additional domains beyond the formal language domain if that is what is required to determine a final truth value
in mathematics and logic a finitary boolean function or switching function is a function of the form ƒ bk → b where b 0 1 is a boolean domain and k is a non negative integer called the arity of the function in the case where k 0 the function is essentially a constant element of b every k ary boolean function can be expressed as a propositional formula in k variables x 1 … xk and two propositional formulas are logically equivalent if and only if they express the same boolean function there are 22 k k ary functions for every k
in computer science the boolean satisfiability problem sometimes called propositional satisfiability problem and abbreviated as satisfiability or sat is the problem of determining if there exists an interpretation that satisfies a given boolean formula in other words it asks whether the variables of a given boolean formula can be consistently replaced by the values true or false in such a way that the formula evaluates to true if this is the case the formula is called satisfiable on the other hand if no such assignment exists the function expressed by the formula is false for all possible variable assignments and the formula is unsatisfiable for example the formula a and not b is satisfiable because one can find the values a true and b false which make a and not b true in contrast a and not a is unsatisfiable sat is one of the first problems that was proven to be np complete this means that all problems in the complexity class np which includes a wide range of natural decision and optimization problems are at most as difficult to solve as sat there is no known algorithm that efficiently solves each sat problem and it is generally believed that no such algorithm exists yet this belief has not been proven mathematically and resolving the question whether sat has a polynomial time algorithm is equivalent to the p versus np problem which is a famous open problem in the theory of computing nevertheless today s heuristical sat algorithms are able to solve problem instances involving tens of thousands of variables and formulas consisting of millions of symbols which is sufficient for many practical sat problems from e g artificial intelligence circuit design and automatic theorem proving
boomerang dysplasia is a lethal form of osteochondrodysplasia known for a characteristic congenital feature in which bones of the arms and legs are malformed into the shape of a boomerang death usually occurs in early infancy due to complications arising from overwhelming systemic bone malformations osteochondrodysplasias are skeletal disorders that cause malformations of both bone and cartilage
the boord olefin synthesis is an organic reaction forming alkenes from ethers carrying a halogen atom 2 carbons removed from the oxygen atom β halo ethers using a metal such as magnesium or zinc the reaction discovered by cecil e boord in 1930 is a classic named reaction with high yields and broad scope the boord olefin synthesis the reaction type is an elimination reaction with magnesium forming an intermediate grignard reagent the alkoxy group is a poor leaving group and therefore an e 1 cb elimination reaction mechanism is proposed the original publication describes the organic synthesis of the compound isoheptene in several steps boord synthesis of isoheptene 1930 in a 1931 publication the scope is extended to 1 4 dienes with magnesium replaced by zinc see also barbier reaction in the first part of the reaction the allyl grignard acts as a nucleophile in nucleophilic aliphatic substitution boord diene synthesis 1931
borderline lepromatous leprosy is a skin condition with numerous symmetrical skin lesions
borderline leprosy is a cutaneous skin condition with numerous skin lesions that are red irregularly shaped plaques
borderline personality disorder bpd also known as emotionally unstable personality disorder is a long term pattern of abnormal behavior characterized by unstable relationships with other people unstable sense of self and unstable emotions there is often an extreme fear of abandonment frequent dangerous behavior a feeling of emptiness and self harm symptoms may be brought on by seemingly normal events the behavior typically begins by early adulthood and occurs across a variety of situations substance abuse depression and eating disorders are commonly associated with bpd about 10 of those with bpd die by suicide bpd s causes are unclear but seem to involve genetic brain environment and social factors it occurs about five times more often in a person who has an affected close relatives adverse life events also appear to play a role the underlying mechanism appears to involve the frontolimbic network of neurons bpd is recognized by the diagnostic and statistical manual of mental disorders dsm as personality disorder along with nine other such disorders diagnosis is based on the symptoms while a medical exam may be done to rule out other problems the condition must be differentiated from an identity problem or substance use disorders among other possibilities borderline personality disorder is typically treated with therapy such as cognitive behavioral therapy cbt another type dialectical behavior therapy dbt has been found to reduce the risk of suicide therapy may occur one on one or in a group while medications do not cure bpd they may be used to help with the associated symptoms some people require care in hospital about 1 6 of people have bpd in a given year females are diagnosed about three times as often as males it appears to become less common among older people up to half of people improve over a ten year period people affected typically use a high amount of healthcare resources there is an ongoing debate about the naming of the disorder especially the suitability of the word borderline
borderline tuberculoid leprosy is a cutaneous condition similar to tuberculoid leprosy except the skin lesions are smaller and more numerous
in mathematics borel isomorphism is a bijective borel function from one polish space to another polish space clarification a subset of the domain is borel if and only if its image under the borel isomorphism is borel borel isomorphisms are closed under composition and under taking of inverses the set of borel isomorphisms from a polish space to itself clearly forms a group under composition borel isomorphisms on polish spaces are analogous to homeomorphisms on topological spaces both are bijective and closed under composition and a homeomorphism and its inverse are both continuous instead of both being borel measurable
borna disease is an infectious neurological syndrome of warm blooded animals caused by borna disease viruses 1 and 2 bodv 1 2 both of which are members of the species mammalian 1 bornavirus bodv 1 an 2 cause abnormal behaviour and fatality borna disease viruses 1 and 2 are neurotropic viruses and members of the bornaviridae family within the mononegavirales order although borna disease viruses 1 and 2 are mainly seen as the causative agent of borna disease in horses and other animals they are also controversially discussed as human infectious agents and therefore as potentialzoonotic agents the role of bodv 1 and 2 in human illness is controversial and it is yet to be established whether bodv 1 or 2 cause any overt disease in humans however correlative evidence exists linking bodv 1 2 infection with neuropsychiatric disorders such as bipolar disorder
bornholm disease or epidemic pleurodynia or epidemic myalgia is a disease caused by the coxsackie b virus or other viruses it is named after the danish island of bornholm where early cases occurred
boron deficiency is a pathology which may occur in animals due to a lack of boron a report given by e wayne johnson et al at the 2005 alan d leman swine conference suggests that boron deficiency produces osteochondrosis in swine that is correctable by addition of 50 ppm of boron to the diet the amount of boron required by animals and humans is not yet well established
boron deficiency is a common deficiency of the micronutrient boron in plants it is the most widespread micronutrient deficiency around the world and causes large losses in crop production and crop quality boron deficiency affects vegetative and reproductive growth of plants resulting in inhibition of cell expansion death of meristem and reduced fertility plants contain boron both in a water soluble and insoluble form in intact plants the amount of water soluble boron fluctuates with the amount of boron supplied while insoluble boron does not the appearance of boron deficiency coincides with the decrease of water insoluble boron it appears that the insoluble boron is the functional form while the soluble boron represents the surplus boron is essential for the growth of higher plants the primary function of the element is to provide structural integrity to the cell wall in plants other functions likely include the maintenance of the plasma membrane and other metabolic pathways
the borrmann effect or borrmann – campbell effect after gerhard borrmann and herbert n campbell is the anomalous increase in the intensity of x rays transmitted through a crystal when it is being set up for bragg reflection the borrmann effect — a dramatic increase in transparency to x ray beams — is observed when x rays satisfying bragg s law diffract through a perfect crystal the minimization of absorption seen in the borrmann effect has been explained by noting that the electric field of the x ray beam approaches zero amplitude at the crystal planes thus avoiding the atoms
metal catalyzed c – h borylation reactions are transition metal catalyzed organic reactions that produce an organoboron compound through functionalization of aliphatic and aromatic c – h bonds and are therefore useful reactions for carbon – hydrogen bond activation metal catalyzed c – h borylation reactions utilize transition metals to directly convert a c – h bond into a c – b bond this route can be advantageous compared to traditional borylation reactions by making use of cheap and abundant hydrocarbon starting material limiting prefunctionalized organic compounds reducing toxic byproducts and streamlining the synthesis of biologically important molecules boronic acids and boronic esters are common boryl groups incorporated into organic molecules through borylation reactions boronic acids are trivalent boron containing organic compounds that possess one alkyl substituent and two hydroxyl groups similarly boronic esters possess one alkyl substituent and two ester groups boronic acids and esters are classified depending on the type of carbon group r directly bonded to boron for example alkyl alkenyl alkynyl and aryl boronic esters the most common type of starting materials that incorporate boronic esters into organic compounds for transition metal catalyzed borylation reactions have the general formula ro 2 b b or 2 for example bis pinacolato diboron b 2 pin 2 and bis catecholato diborane b 2 cat 2 are common boron sources of this general formula b 2 pin 2 and b 2 cat 2 the boron atom of a boronic ester or acid is sp 2 hybridized possessing a vacant p orbital enabling these groups to act as lewis acids the c – b bond of boronic acids and esters are slightly longer than typical c – c single bonds with a range of 1 55 1 59 å the lengthened c – b bond relative to the c – c bond results in a bond energy that is also slightly less than that of c – c bonds 323 kj mol for c – b vs 358 kj mol for c – c the carbon – hydrogen bond has a bond length of about 1 09 å and a bond energy of about 413 kj mol the c – b bond is therefore a useful intermediate as a bond that replaces a typically unreactive c – h bond organoboron compounds are organic compounds containing a carbon boron bond organoboron compounds have broad applications for chemical synthesis because the c – b bond can easily be converted into a c – x x br cl c – o c – n or c – c bond because of the versatility of the c – b bond numerous processes have been developed to incorporate them into organic compounds organoboron compounds are traditionally synthesized from grignard reagents through hydroboration or diboration reactions borylation provides an alternative
the bosch reaction is a chemical reaction between carbon dioxide and hydrogen that produces elemental carbon graphite water and a 10 return of invested heat it is named after the german chemist carl bosch this reaction requires the introduction of iron as a catalyst and requires a temperature level of 530 730 degrees celsius the overall reaction is as follows co 2 g 2 h 2 g → c s 2 h 2 o g the above reaction is actually the result of two reactions the first reaction the reverse water gas shift reaction is a fast one co 2 h 2 → co h 2 o the second reaction controls the reaction rate co h 2 → c h 2 o the overall reaction produces 2 3 × 103 joules for every gram of carbon dioxide reacted at 650 ° c reaction temperatures are in the range of 450 to 600 ° c the reaction can be accelerated in the presence of an iron cobalt or nickel catalyst ruthenium also serves to speed up the reaction together with the sabatier reaction the bosch reaction is studied as a way to remove carbon dioxide and to generate clean water aboard a space station the reaction is also used to produce graphite for radiocarbon dating with accelerator mass spectrometry the bosch reaction is being investigated for use in maintaining space station life support though the bosch reaction would present a completely closed hydrogen and oxygen cycle which only produces atomic carbon as waste difficulties in maintaining its higher required temperature and properly handling carbon deposits mean that significantly more research will be required before a bosch reactor can become a reality one problem is that the production of elemental carbon tends to foul the catalyst s surface which is detrimental to the reaction s efficiency
boston exanthem disease is a cutaneous condition that first occurred as an epidemic in boston in 1951 it is caused by echovirus 16 the disease tends to afflict children more often than adults although some adults can become infected and the symptoms have never been fatal it shows some clinical similarity to rubella and human herpesvirus 6
the bosworth fracture is a rare fracture of the distal fibula with an associated fixed posterior dislocation of the proximal fibular fragment which becomes trapped behind the posterior tibial tubercle the injury is caused by severe external rotation of the ankle the ankle remains externally rotated after the injury making interpretation of x rays difficult which can lead to misdiagnosis and incorrect treatment the injury is most commonly treated by open reduction internal fixation as closed reduction is made difficult by the entrapment of the fibula behind the tibia the entrapment of an intact fibula behind the tibia was described by ashhurst and bromer in 1922 who attributed the description of the mechanism of injury to huguier s 1848 publication the injury involving fibular fracture with posterior dislocation was described by david m bosworth in 1947
the botryoid odontogenic cyst is a variant of the lateral periodontal cyst it is more often found in middle aged and older adults and the teeth more likely affected are mandibular lower canines and premolars on radiographs the cyst appears grape like often patients with this condition are symptomatic
botryomycosis also known as bacterial pseudomycosis is a rare chronic granulomatous bacterial infection that affects the skin and sometimes the viscera botryomycosis has been known to affect humans horses cattle swine dogs and cats it can occur in recently castrated horses if proper hygiene is not followed and the end of the spermatic chord becomes infected with s aureus
bot canker of oak is a disease on stems branches and twigs of oak trees in europe and north america the casual agent of bot canker of oak is the fungus botryosphaeria corticola bot canker of oak causes lesions and cankers on a wide range of oaks in europe and most recently live oaks in north america some infections were formerly attributed to botryosphaeria stevensii but most likely represent infections by botryosphaeria corticola botryosphaeria corticola is distinguishable from botryosphaeria stevensii via its rdna sequencing
bottle shock or bottle sickness is a temporary condition of wine characterized by muted or disjointed fruit flavors it often occurs immediately after bottling or when wines usually fragile wines are given an additional dose of sulfur in the form of sulfur dioxide or sulfite solution or if they are subject to other forms of handling and transport after a few weeks the condition usually disappears
in engineering a bottleneck is a phenomenon by which the performance or capacity of an entire system is severely limited by a single component the component is sometimes called a bottleneck point the term is metaphorically derived from the neck of a bottle where the flow speed of the liquid is limited by its neck formally a bottleneck lies on a system s critical path and provides the lowest throughput bottlenecks are usually avoided by system designers also a great amount of effort is directed at locating and tuning them bottleneck may be for example a processor a communication link a data processing software etc
the bottleneck traveling salesman problem bottleneck tsp is a problem in discrete or combinatorial optimization it is stated as follows find the hamiltonian cycle in a weighted graph which minimizes the weight of the most weighty edge of the cycle the problem is known to be np hard the decision problem version of this for a given length x is there a hamiltonian cycle in a graph g with no edge longer than x is np complete in an asymmetric bottleneck tsp there are cases where the weight from node a to b is different from the weight from b to a e g travel time between two cities with a traffic jam in one direction euclidean bottleneck tsp or planar bottleneck tsp is the bottleneck tsp with the distance being the ordinary euclidean distance the problem still remains np hard however many heuristics work better if the graph is a metric space then there is an efficient approximation algorithm that finds a hamiltonian cycle with maximum edge weight being no more than twice the optimum
in the technical analysis of security prices a bottom is a chart pattern where prices reach a low then a lower low and then a higher low according to some technical analysis theories the first low signifies the pressure from selling was greater than the pressure from buying the second lower low suggests that selling still had more pressure than the buying the third higher low suggests that buying pressure will not let prices fall as low as the previous low this turning point from selling pressure to buying pressure is called a bottom
botulism is a rare and potentially fatal illness caused by a toxin produced by the bacterium clostridium botulinum the disease begins with weakness trouble seeing feeling tired and trouble speaking this may then be followed by weakness of the arms chest muscles and legs the disease does not usually affect consciousness or cause a fever botulism can be spread several different ways the bacterial spores which cause it are common in both soil and water they produce the botulinum toxin when exposed to low oxygen levels and certain temperatures foodborne botulism happens when food containing the toxin is eaten infant botulism happens when the bacteria develops in the intestines and releases the toxin this typically only occurs in children less than six months old as protective mechanisms develop after that time wound botulism is found most often among those who inject street drugs in this situation spores enter a wound and in the absence of oxygen release the toxin it is not passed directly between people the diagnosis is confirmed by finding the toxin or bacteria in the person in question prevention is primarily by proper food preparation the toxin though not the organism is destroyed by heating it to more than 85 ° c 185 ° f for longer than 5 minutes honey can contain the organism and for this reason honey should not be fed to children under 12 months treatment is with an antitoxin in those who lose their ability to breathe on their own mechanical ventilation may be necessary for months antibiotics may be used for wound botulism death occurs in 5 to 10 of people botulism can affect many other animals the word is from latin botulus meaning sausage
bouffée délirante refers to a sudden outburst of aggression and during the episode the person may see or hear things that aren t really there it also involves marked confusion and psychomotor excitement this syndrome may also cause visual and auditory hallucinations or paranoia bouffée délirante is a culture bound syndrome which is common in west africa and haiti
as distinct from the demarcation problem or boundary problem in the philosophy of science boundary problem in spatial analysis is a geographical phenomenon as one of the four major issues that interfere with an accurate estimation of the statistical parameter the four issues include the boundary problem as well as the scale problem pattern problem or spatial autocorrelation and modifiable areal unit problem barber 1988 the boundary problem occurs because of the loss of neighbors in analyses that depend on the values of the neighbors while geographic phenomena are measured and analyzed within a specific unit identical spatial data can appear either dispersed or clustered depending on the boundary placed around the data in analysis with point data dispersion is evaluated as dependent of the boundary in analysis with areal data statistics should be interpreted based upon the boundary in geographical research two types of areas are taken into consideration in relation to the boundary an area surrounded by fixed natural boundaries e g coastlines or streams outside of which neighbors do not exist henley 1981 or an area included in a larger region defined by arbitrary artificial boundaries e g an air pollution boundary in modeling studies or an urban boundary in population migration haining 1990 in an area isolated by the natural boundaries the spatial process discontinues at the boundaries in contrast if a study area is delineated by the artificial boundaries the process continues beyond the area if a spatial process in an area occurs beyond a study area or has an interaction with neighbors outside artificial boundaries the most common approach is to neglect the influence of the boundaries and assume that the process occurs at the internal area however such an approach leads to a significant model misspecification problem upton and fingleton 1985 that is for measurement or administrative purposes geographic boundaries are drawn but the boundaries per se can bring about different spatial patterns in geographic phenomena besr 2002 it has been reported that the difference in the way of drawing the boundary significantly affects identification of the spatial distribution and estimation of the statistical parameters of the spatial process cressie 1992 fotheringham and rogerson 1993 griffith 1983 martin 1987 the difference is largely based on the fact that spatial processes are generally unbounded or fuzzy bounded leung 1987 but the processes are expressed in data imposed within boundaries for analysis purposes miller 1999 although the boundary problem was discussed in relation to artificial and arbitrary boundaries the effect of the boundaries also occurs according to natural boundaries as long as it is ignored that properties at sites on the natural boundary such as streams are likely to differ from those at sites within the boundary martin 1989 the boundary problem occurs with regard not only to horizontal boundaries but also to vertically drawn boundaries according to delineations of heights or depths pineda 1993 for example biodiversity such as the density of species of plants and animals is high near the surface so if the identically divided height or depth is used as a spatial unit it is more likely to find fewer number of the plant and animal species as the height or depth increases figure 1 boundary problem urban sprawl in central florida an evaluation by land cover analysis with raster datasets vs an evaluation by population density bounded in the census tract figure 2 boundary problem horizontal boundaries figure 3 boundary problem vertical boundaries
in harmonic analysis in mathematics a function of bounded mean oscillation also known as a bmo function is a real valued function whose mean oscillation is bounded finite the space of functions of bounded mean oscillation bmo is a function space that in some precise sense plays the same role in the theory of hardy spaces hp that the space l ∞ of essentially bounded functions plays in the theory of lp spaces it is also called john – nirenberg space after fritz john and louis nirenberg who introduced and studied it for the first time
in mathematical analysis a function of bounded variation also known as a bv function is a real valued function whose total variation is bounded finite the graph of a function having this property is well behaved in a precise sense for a continuous function of a single variable being of bounded variation means that the distance along the direction of the y axis neglecting the contribution of motion along x axis traveled by a point moving along the graph has a finite value for a continuous function of several variables the meaning of the definition is the same except for the fact that the continuous path to be considered cannot be the whole graph of the given function which is a hypersurface in this case but can be every intersection of the graph itself with a hyperplane in the case of functions of two variables a plane parallel to a fixed x axis and to the y axis functions of bounded variation are precisely those with respect to which one may find riemann – stieltjes integrals of all continuous functions another characterization states that the functions of bounded variation on a compact interval are exactly those f which can be written as a difference g − h where both g and h are bounded monotone in the case of several variables a function f defined on an open subset ω of ℝn is said to have bounded variation if its distributional derivative is a vector valued finite radon measure one of the most important aspects of functions of bounded variation is that they form an algebra of discontinuous functions whose first derivative exists almost everywhere due to this fact they can and frequently are used to define generalized solutions of nonlinear problems involving functionals ordinary and partial differential equations in mathematics physics and engineering we have the following chains of inclusions for functions over a compact subset of the real line continuously differentiable ⊆ lipschitz continuous ⊆ absolutely continuous ⊆ bounded variation ⊆ differentiable almost everywhere
boutonneuse fever also called mediterranean spotted fever fièvre boutonneuse kenya tick typhus indian tick typhus marseilles fever or african tick bite fever is a fever as a result of a rickettsial infection caused by the bacterium rickettsia conorii and transmitted by the dog tick rhipicephalus sanguineus boutonneuse fever can be seen in many places around the world although it is endemic in countries surrounding the mediterranean sea this disease was first described in tunisia in 1910 by conor and bruch and was named boutonneuse french for spotty due to its papular skin rash characteristics
boutonniere deformity is a deformed position of the fingers or toes in which the joint nearest the knuckle the proximal interphalangeal joint or pip is permanently bent toward the palm while the farthest joint the distal interphalangeal joint or dip is bent back away pip flexion with dip hyperextension it is commonly caused by injury or by an inflammatory condition like rheumatoid arthritis or genetic conditions like ehlers danlos syndrome
the bouveault aldehyde synthesis also known as the bouveault reaction is a one pot substitution reaction that replaces an alkyl or aryl halide with a formyl group using a n n disubstituted formamide for primary alkyl halides this produces the homologous aldehyde one carbon longer for aryl halides this produces the corresponding carbaldehyde bouveault aldehyde synthesis is an example of a formylation reaction the bouveault aldehyde synthesis
the bouveault – blanc reduction is a chemical reaction in which an ester is reduced to primary alcohols using absolute ethanol and sodium metal the bouveault blanc reduction this reaction is an inexpensive and large scale alternative to lithium aluminium hydride reduction of esters
bovine ephemeral fever bef also known as three day sickness is an arthropod vector borne disease of cattle and is caused by bovine ephemeral fever virus befv a member of the genus ephemerovirus in the family rhabdoviridae befv forms a bullet or cone shaped virions that consist of a negative single stranded rna genome with a lipid envelope and 5 structural proteins the envelope glycoprotein g contains type specific and neutralizing antigenic sites theres has been recent evidence which demonstrated that befv induces apoptosis in several cell lines it was however shown that apoptosis could be blocked by the caspase inhibitor z vad fmk indicating that befv induces caspase dependent apoptosis in cultured cells
bovine malignant catarrhal fever bmcf is a fatal lymphoproliferative disease caused by a group of ruminant gamma herpes viruses including alcelaphine herpes virus 1 alhv 1 and ovine herpes virus 2 ovhv 2 these viruses cause inapparent infection in their reservoir hosts sheep with ovhv 2 and wildebeest with alhv 1 but are usually fatal in cattle and other ungulates such as deer antelope and buffalo bmcf is an important disease where reservoir and susceptible animals mix there is a particular problem with bali cattle in indonesia bison in the usa and in pastoralist herds in eastern and southern africa disease outbreaks in cattle are usually sporadic although infection of up to 40 of a herd has been reported the reasons for this are unknown some species appear to be particularly susceptible for example pére davids deer bali cattle and bison with many deer dying within 48 hours of the appearance of the first symptoms and bison within three days in contrast post infection cattle will usually survive a week or more
bovine papular stomatitis is a disease caused by a virus of the family poxviridae and the genus parapoxvirus it occurs worldwide in cattle symptoms include reddish raised sometimes ulcerative lesions on the lips muzzle and in the mouth it usually occurs before the age of two years reinfection is possible because of the short duration of immunity clinically the disease is mild but its importance lies in the need to differentiate it from foot and mouth disease there have been reports of both lesions on the hands of milkers and similar infections in sheep and goats as well as humans
bovine prolapsed uterus is a condition usually caused by strain during calving the uterus is prolapsed and creates a condition which can be fatal if not promptly treated generally accepted treatment is to wrap the uterus in clean moist warm cloth until veterinarian assistance arrives long term treatment is described in bovine surgery and lameness by a david weaver guy st jean and adrian steiner blackwell publishing 2005 oxford uk
bovine spongiform encephalopathy bse commonly known as mad cow disease is a fatal neurodegenerative disease encephalopathy in cattle that causes a spongy degeneration of the brain and spinal cord bse has a long incubation period of 2 5 to 5 years usually affecting adult cattle at a peak age onset of four to five years all breeds being equally susceptible bse is caused by a misfolded protein — a prion in the united kingdom the country worst affected by an epidemic in 1986 – 1998 more than 180 000 cattle were infected and 4 4 million slaughtered during the eradication program the disease may be most easily transmitted to humans by eating food contaminated with the brain spinal cord or digestive tract of infected carcasses however the infectious agent although most highly concentrated in nervous tissue can be found in virtually all tissues throughout the body including blood in humans it is known as new variant creutzfeldt – jakob disease vcjd or nvcjd and by june 2014 it had killed 177 people in the united kingdom and 52 elsewhere between 460 000 and 482 000 bse infected animals had entered the human food chain before controls on high risk offal were introduced in 1989 a british and irish inquiry into bse concluded the epizootic was caused by cattle which are normally herbivores being fed the remains of other cattle in the form of meat and bone meal mbm which caused the infectious agent to spread the cause of bse may be from the contamination of mbm from sheep with scrapie that were processed in the same slaughterhouse the epidemic was probably accelerated by the recycling of infected bovine tissues prior to the recognition of bse the origin of the disease itself remains unknown the infectious agent is distinctive for the high temperatures at which it remains viable over 600 ° c about 1100 ° f this contributed to the spread of the disease in the united kingdom which had reduced the temperatures used during its rendering process another contributory factor was the feeding of infected protein supplements to very young calves
bovine viral diarrhea bvd or bovine viral diarrhoea uk english and previously referred to as bovine virus diarrhoea bvd is a significant economic disease of cattle which is endemic in the majority of countries throughout the world the causative agent bovine viral diarrhea virus bvdv is a member of the pestivirus genus of the family flaviviridae bvd infection results in a wide variety of clinical signs due to its immunosuppressive effects as well as having a direct effect on respiratory disease and fertility in addition bvd infection of a susceptible dam during a certain period of gestation can result in the production of a persistently infected pi fetus pi animals recognise intra cellular bvd viral particles as ‘ self ’ and shed virus in large quantities throughout life they represent the cornerstone of the success of bvd as a disease
tendinitis tendonitis is inflammation of a tendon many times the tendon tissue is torn a bowed tendon is a horseman s term for a tendon after a horse has sustained an injury that caused the tendon fibers to be torn and then healed with bowed appearance
bowel infarction results from restricted blood supply to the bowel most often due to bowel obstruction or occlusion of one of the mesenteric arteries bowel obstruction is most often caused by intestinal adhesions which frequently form after abdominal surgeries or by chronic infections such as diverticulitis hepatitis and inflammatory bowel disease the condition is difficult to diagnose properly as the symptoms may resemble those of other bowel disorders patients who have undergone extensive resection of the small bowel may develop malabsorption indicating the need for dietary supplements volvulus is a rare but life threatening cause of bowel infarction which requires immediate medical attention central abdominal pain which is resistant to narcotic analgesia may be an indication of bowel infarction
bowel obstruction also known as intestinal obstruction is a mechanical or functional obstruction of the intestines which prevents the normal movement of the products of digestion either the small bowel or large bowel may be affected symptoms include abdominal pain vomiting bloating and not passing gas mechanical obstruction is the cause of about 5 to 15 of cases of severe abdominal pain of sudden onset requiring admission to hospital causes of bowel obstruction include adhesions hernias volvulus endometriosis inflammatory bowel disease appendicitis tumors diverticulitis ischemic bowel tuberculosis and intussusception small bowel obstructions are most often due to adhesions and hernias while large bowel obstructions are most often due to tumors and volvulus the diagnosis may be made on plain x rays however ct scan is more accurate ultrasound or mri may help in the diagnosis of children or pregnant women the condition may be treated conservatively or with surgery typically intravenous fluids are given a tube is placed through the nose into the stomach to decompress the intestines and pain medications are given antibiotics are often given in small bowel obstruction about 25 require surgery complications may include sepsis bowel ischemia and bowel perforation about 2 5 million cases of or bowel obstruction occurred in 2013 which resulted in 236 000 deaths both sexes are equally affected and the condition can occur at any age bowel obstruction has been documented throughout history with cases detailed in the ebers papyrus of 1550 bc and by hippocrates
bowen s disease bd also known as squamous cell carcinoma in situ is a neoplastic skin disease it can be considered as an early stage or intraepidermal form of squamous cell carcinoma it was named after john t bowen erythroplasia of queyrat is a particular type of squamous cell carcinoma in situ which can arise on the glans or prepuce in males and vulva in females and may be induced by human papilloma virus it is reported to occur in corneoscleral limbus
bowenoid papulosis is a cutaneous condition characterized by the presence of pigmented verrucous papules on the body of the penis they are associated with human papillomavirus the causative agent of genital warts the lesions have a typical dysplastic histology and are generally considered benign although a small percentage will develop malignant characteristics it is considered as a pre malignant condition other terms used to describe the condition are erythroplasia of queyrat squamous cell carcinoma in situ and bowen ’ s disease the term bowenoid papulosis was coined in 1977 by kopf and bart and is named after dermatologist john templeton bowen the term “ intraepithelial neoplasia ” defines a premalignant intraepithelial change on the vulva it is termed vin vulvar or vulval intraepithelial neoplasia on the penis pin penile intraepithelial neoplasia and on or around the anus ain anal intraepithelial neoplasia the terminology has been very confusing and it is now recommended that the terms bowen ’ s disease erythroplasia of queyrat and bowenoid papulosis should not be used for lesions in the anogenital area however dermatologists still recognize a distinct clinical variant bowenoid papulosis characterized by discrete papules in a younger age group and a tendency for spontaneous regression additionally some authorities believe that erythroplasia of queyrat and bowen ’ s disease remain useful terms in men epidemiology it may occur at any age the incidence in young women is rising
bowen – conradi syndrome bcs or bwcns is a disease in humans that can affect children the disease is due to an autosomal recessive abnormality of the emg 1 gene which plays a role in small ribosomal subunit ssu assembly the preponderance of diagnoses has been in north american hutterite children but bwcns can affect other population groups bwcns is a ribosomopathy a d 86 g mutation of emg 1 destroys an ecorv restriction endonuclease site in the most highly conserved region of the protein skeletal dysmorphology is seen and severe prenatal and postnatal growth failure usually leads to death by one year of age
a bowie knife pronounced ˈbuːiː boo ee or ˈboʊ iː bow ee is a pattern of fixed blade fighting knife created by james black in the early 19 th century for jim bowie who had become famous for his use of a large knife at a duel known as the sandbar fight since the first incarnation the bowie knife has come to incorporate several recognizable and characteristic design features although in common usage the term refers to any large sheath knife with a crossguard and a clip point the knife pattern is still popular with collectors in addition to various knife manufacturing companies there are hundreds of custom knife makers producing bowies and variations
in toss juggling the box is a juggling pattern for 3 objects most commonly balls or bean bags two balls are dedicated to a specific hand with vertical throws and the third ball is thrown horizontally between the two hands its siteswap is 4 2 x 2 x 4 the box pattern can be seen as a synchronous shower which direction is changed at every throw the half box is similar but asynchronous with siteswap 441
boxer s fracture is a colloquial term for a fracture of one of the metacarpal bones of the hand classically the fracture occurs transversely across the neck of the bone after the patient strikes an object with a closed fist alternate terms include scrapper s fracture or bar room fracture as these are colloquial terms texts and medical dictionaries do not universally agree on precise meanings various authorities state that a boxer s fracture means a break in specifically the second metacarpal bone or third metacarpal bone with bar room fracture being specific to the fourth metacarpal bone or fifth metacarpal bone though some writers assert that boxer s fracture and bar room fracture are distinct terms representing injuries to different bones this distinction seems to have been lost over time and most medical professionals now describe any metacarpal fracture as a boxer s fracture
boxer cardiomyopathy also known as boxer arrhythmogenic right ventricular cardiomyopathy is a disease of the myocardium primarily affecting boxer dogs it is characterized by the development of ventricular tachyarrhythmias resulting in syncope and sudden cardiac death myocardial failure and congestive heart failure are uncommon manifestations of the disease
boxwood blight also known as box blight or boxwood leaf drop is a widespread fungal disease affecting boxwoods caused by cylindrocladium buxicola also called c pseudonaviculatum
the boyland – sims oxidation is the chemical reaction of anilines with alkaline potassium persulfate which after hydrolysis forms ortho hydroxyl anilines the boyland sims oxidation the ortho isomer is formed predominantly however the para sulfate is formed in small amounts with certain anilines
the brachial plexus is a network of nerves that conducts signals from the spinal cord which is housed in the spinal canal of the vertebral column or spine to the shoulder arm and hand these nerves originate in the fifth sixth seventh and eighth cervical c 5 – c 8 and first thoracic t 1 spinal nerves and innervate the muscles and skin of the chest shoulder arm and hand brachial plexus injuries or lesions are caused by damage to those nerves brachial plexus injuries or lesions can occur as a result of shoulder trauma tumours or inflammation the rare parsonage turner syndrome causes brachial plexus inflammation without obvious injury but with nevertheless disabling symptoms but in general brachial plexus lesions can be classified as either traumatic or obstetric obstetric injuries may occur from mechanical injury involving shoulder dystocia during difficult childbirth traumatic injury may arise from several causes the brachial plexus may be injured by falls from a height on to the side of the head and shoulder whereby the nerves of the plexus are violently stretched the brachial plexus may also be injured by direct violence or gunshot wounds by violent traction on the arm or by efforts at reducing a dislocation of the shoulder joint
brachioradial pruritus sometimes abbreviated brp is an intense itching sensation of the arm usually between the wrist and elbow of either or both arms the itch can be so intense that sufferers will scratch their own skin to a bleeding condition the condition is becoming increasingly common presenting in patients who are usually fair skinned and middle aged and indulge in golf tennis outdoor table tennis sailing or other leisure outdoor activities in sunny climates the cause is not known although there are a few lines of thought on what causes it no cure has been found many different medications and types of topical creams have been experimented with but none seem to make any difference the only thing that seems to help most sufferers is the application of ice to the area until the itch is diminished
brachycephalic syndrome is a pathological condition affecting short nosed dogs and cats which leads to severe respiratory distress there are four different anatomical abnormalities that contribute to the disease all of which occur more commonly in brachycephalic breeds an elongated soft palate stenotic nares a hypoplastic trachea and everted laryngeal saccules a condition which occurs secondarily to the other abnormalities because all of these components make it more difficult to breathe in situations of exercise stress or heat an animal with these abnormalities may be unable to take deep or fast enough breaths to blow off carbon dioxide this leads to distress and further increases respiratory rate and heart rate creating a vicious circle that can quickly lead to a life threatening situation dogs experiencing a crisis situation due to brachycephalic syndrome typically benefit from oxygen cool temperatures sedatives and in some cases more advanced medical intervention including intubation
brachycephaly from greek roots meaning short and head is the shape of a skull shorter than typical for its species it is perceived as a desirable trait in some domesticated dog and cat breeds such as pugs and can be normal or abnormal in other animal species in humans the cephalic disorder is known as flat head syndrome and results from premature fusion of the coronal sutures see craniosynostosis or from external deformation see plagiocephaly the coronal suture is the fibrous joint that unites the frontal bone with the two parietal bones of the skull the parietal bones form the top and sides of the skull this feature can be seen in down syndrome in anthropology human populations have been characterized as either dolichocephalic long headed mesaticephalic moderate headed or brachycephalic short headed the usefulness of the cephalic index was questioned by giuseppe sergi who argued that cranial morphology provided a better means to model racial ancestry the incidence of brachycephaly in people has increased since the advent of sudden infant death syndrome recommendations for parents to keep their babies on their backs it is considered a cosmetic problem many pediatricians remain unaware of the issue and possible treatments treatments include regular prone repositioning of babies tummy time there are also cases of brachycephaly associated with plagiocephaly this deformity occurs when there is a combination of brachycephaly and plagiocephaly present brachycephaly with plagiocephaly is positional and has become more prevalent since the back to sleep campaign the back to sleep campaign began in 1994 as a way to educate parents caregivers and health care providers about ways to reduce the risk for sudden infant death syndrome sids the campaign was named for its recommendation to place healthy babies on their backs to sleep placing babies on their backs to sleep reduces the risk for sids also known as cot death or crib death this campaign has been successful in promoting infant back sleeping and other risk reduction strategies to parents family members child care providers health professionals and all other caregivers of infants at a cost of increasing the incidence of this deformation of the head brachycephaly also describes a developmentally normal type of skull with a high cephalic index such as in snub nosed breeds of dog such pugs and bulldogs or cats such as the persian exotic and himalayan
brachydactyly greek βραχύς short plus δάκτυλος finger is a medical term which literally means shortness of the fingers and toes digits the shortness is relative to the length of other long bones and other parts of the body brachydactyly is an inherited usually dominant trait it most often occurs as an isolated dysmelia but can also occur with other anomalies as part of many congenital syndromes nomograms for normal values of finger length as a ratio to other body measurements have been published in clinical genetics the most commonly used index of digit length is the dimensionless ratio of the length of the 3 rd middle finger to the hand length both are expressed in the same units centimeters for example and are measured in an open hand from the fingertip to the principal creases where the finger joins the palm and where the palm joins the wrist a nomogram can be found in the appendix of jones ed smith s recognizable patterns of human malformation 5 th edition philadelphia saunders 1997
brachymetatarsia or hypoplastic metatarsal is a condition in which there is one or more abnormally short or overlapping toes metatarsals this condition may result due to a congenital defect or it may be an acquired condition it most frequently involves the fourth metatarsal if it involves the first metatarsal the condition is known as morton s syndrome treatment is via a number of differing surgical procedures
brachyptery is an anatomical condition in which an animal has very reduced wings such animals or their wings may be described as brachypterous brachypterous wings generally are not functional as organs of flight and often seem to be totally functionless and vestigial in some species however wings that are vestigial in the sense of not retaining any function related to flight may have other functions such as organs of aposematic display in some orthoptera and phasmatodea brachyptery occurs commonly among insects an insect species might evolve towards brachyptery in reducing its flight muscles with their associated energy demands or in avoiding the hazards of flight in windy conditions on oceanic islands in which flying insects are prone to drowning brachyptery also is common in ectoparasitic insects that have no use for wings and inquiline insects with socially parasitic life strategies that do not require functional wings in some species of insects brachyptery occurs in some members say in only one gender or only some castes whereas fully functional wings occur in macropterous individuals other forms of brachyptery may depend on the temperature at which the insect grew and developed in winter for example some species grow reduced wings whereas in summer they grow fully developed wings that are adequate for migration the extreme form of brachyptery in which no wings grow at all such as in fleas or worker ants is called aptery
bradford s law is a pattern first described by samuel c bradford in 1934 that estimates the exponentially diminishing returns of searching for references in science journals one formulation is that if journals in a field are sorted by number of articles into three groups each with about one third of all articles then the number of journals in each group will be proportional to 1 n n ² there are a number of related formulations of the principle in many disciplines this pattern is called a pareto distribution as a practical example suppose that a researcher has five core scientific journals for his or her subject suppose that in a month there are 12 articles of interest in those journals suppose further that in order to find another dozen articles of interest the researcher would have to go to an additional 10 journals then that researcher s bradford multiplier bm is 2 i e 10 5 for each new dozen articles that researcher will need to look in bm times as many journals after looking in 5 10 20 40 etc journals most researchers quickly realize that there is little point in looking further different researchers have different numbers of core journals and different bradford multipliers but the pattern holds quite well across many subjects and may well be a general pattern for human interactions in social systems like zipf s law to which it is related we do not have a good explanation for why it works but knowing that it does is very useful for librarians what it means is that for each specialty it is sufficient to identify the core publications for that field and only stock those very rarely will researchers need to go outside that set however its impact has been far greater than that armed with this idea and inspired by vannevar bush s famous article as we may think eugene garfield at the institute for scientific information in the 1960 s developed a comprehensive index of how scientific thinking propagates his science citation index sci had the effect of making it easy to identify exactly which scientists did science that had an impact and which journals that science appeared in it also caused the discovery which some did not expect that a few journals such as nature and science were core for all of hard science the same pattern does not happen with the humanities or the social sciences the result of this is pressure on scientists to publish in the best journals and pressure on universities to ensure access to that core set of journals on the other hand the set of core journals may vary more or less strongly with the individual researchers and even more strongly along schools of thought divides there is also a danger of over representing majority views if journals are selected in this fashion bradford s law is also known as bradford s law of scattering and as the bradford distribution this law or distribution in bibliometrics can be applied to the world wide web
bradley s regress is a philosophical problem concerning the nature of relations it is named after f h bradley who discussed the problem in his 1893 book appearance and reality it bears a close kinship to the issue of the unity of the proposition
brain abscess or cerebral abscess is an abscess caused by inflammation and collection of infected material coming from local ear infection dental abscess infection of paranasal sinuses infection of the mastoid air cells of the temporal bone epidural abscess or remote lung heart kidney etc infectious sources within the brain tissue the infection may also be introduced through a skull fracture following a head trauma or surgical procedures brain abscess is usually associated with congenital heart disease in young children it may occur at any age but is most frequent in the third decade of life
brain damage or brain injury bi is the destruction or degeneration of brain cells brain injuries occur due to a wide range of internal and external factors a common category with the greatest number of injuries is traumatic brain injury tbi following physical trauma or head injury from an outside source and the term acquired brain injury abi is used in appropriate circles to differentiate brain injuries occurring after birth from injury due to a disorder or congenital malady in general brain damage refers to significant undiscriminating trauma induced damage while neurotoxicity typically refers to selective chemically induced neuron damage
brain death is the complete and irreversible loss of brain function including involuntary activity necessary to sustain life brain death is one of the two ways of determination of death according to the uniform determination of death act of the united states the other way of determining death being irreversible cessation of circulatory and respiratory functions it differs from persistent vegetative state in which some autonomic functions remain the australia and new zealand intensive care society anzics states that the determination of brain death requires that there is unresponsive coma the absence of brain stem reflexes and the absence of respiratory centre function in the clinical setting in which these findings are irreversible in particular there must be definite clinical or neuro imaging evidence of acute brain pathology e g traumatic brain injury intracranial haemorrhage hypoxic encephalopathy consistent with the irreversible loss of neurological function brain death is used as an indicator of legal death in many jurisdictions but it is defined inconsistently various parts of the brain may keep living when others die and the term brain death has been used to refer to various combinations for example although a major medical dictionary says that brain death is synonymous with cerebral death death of the cerebrum the us national library of medicine medical subject headings mesh system defines brain death as including the brainstem the distinctions can be important because for example in someone with a dead cerebrum but a living brainstem the heartbeat and ventilation can continue unaided whereas in whole brain death which includes brain stem death only life support equipment would keep those functions going patients classified as brain dead can have their organs surgically removed for organ donation though not everyone agrees with this practice preferring to limit organ donation to those individuals who have suffered the death of all of their brain and the death of their cardiac and respiratory systems biological or full death however if one limits the criteria to those individuals procuring viable organs can become much more difficult
brain herniation is a potentially deadly side effect of very high pressure within the skull that occurs when a part of the brain is squeezed across structures within the skull the brain can shift across such structures as the falx cerebri the tentorium cerebelli and even through the foramen magnum the hole in the base of the skull through which the spinal cord connects with the brain herniation can be caused by a number of factors that cause a mass effect and increase intracranial pressure icp these include traumatic brain injury intracranial hemorrhage or brain tumor herniation can also occur in the absence of high icp when mass lesions such as hematomas occur at the borders of brain compartments in such cases local pressure is increased at the place where the herniation occurs but this pressure is not transmitted to the rest of the brain and therefore does not register as an increase in icp because herniation puts extreme pressure on parts of the brain and thereby cuts off the blood supply to various parts of the brain it is often fatal therefore extreme measures are taken in hospital settings to prevent the condition by reducing intracranial pressure or decompressing draining a hematoma which is putting local pressure on a part of the brain
brain ischemia aka cerebral ischemia cerebrovascular ischemia is a condition in which there is insufficient blood flow to the brain to meet metabolic demand this leads to poor oxygen supply or cerebral hypoxia and thus to the death of brain tissue or cerebral infarction ischemic stroke it is a sub type of stroke along with subarachnoid hemorrhage and intracerebral hemorrhage ischemia leads to alterations in brain metabolism reduction in metabolic rates and energy crisis there are two types of ischemia focal ischemia which is confined to a specific region of the brain and global ischemia which encompasses wide areas of brain tissue the main symptoms involve impairments in vision body movement and speaking the causes of brain ischemia vary from sickle cell anemia to congenital heart defects symptoms of brain ischemia can include unconsciousness blindness problems with coordination and weakness in the body other effects that may result from brain ischemia are stroke cardiorespiratory arrest and irreversible brain damage an interruption of blood flow to the brain for more than 10 seconds causes unconsciousness and an interruption in flow for more than a few minutes generally results in irreversible brain damage in 1974 hossmann and zimmermann demonstrated that ischemia induced in mammalian brains for up to an hour can be at least partially recovered accordingly this discovery raised the possibility of intervening after brain ischemia before the damage becomes irreversible
a brain metastasis is a cancer that has metastasized spread to the brain from another location in the body as primary cancer treatments such as surgery radiation therapy and chemotherapy have become more effective in the past few decades people with cancer are living longer after initial treatment than ever before however brain metastases still occur in many patients months or even years after their original cancer treatment brain metastases have a poor prognosis for cure but modern treatments are allowing patients to live months and sometimes years after the diagnosis
brain morphometry is a subfield of both morphometry and the brain sciences concerned with the measurement of brain structures and changes thereof during development aging learning disease and evolution since autopsy like dissection is generally impossible on living brains brain morphometry starts with noninvasive neuroimaging data typically obtained from magnetic resonance imaging or mri for short these data are born digital which allows researchers to analyze the brain images further by using advanced mathematical and statistical methods such as shape quantification or multivariate analysis this allows researchers to quantify anatomical features of the brain in terms of shape mass volume e g of the hippocampus or of the primary versus secondary visual cortex and to derive more specific information such as the encephalization quotient grey matter density and white matter connectivity gyrification cortical thickness or the amount of cerebrospinal fluid these variables can then be mapped within the brain volume or on the brain surface providing a convenient way to assess their pattern and extent over time across individuals or even between different biological species the field is rapidly evolving along with neuroimaging techniques — which deliver the underlying data — but also develops in part independently from them as part of the emerging field of neuroinformatics which is concerned with developing and adapting algorithms to analyze those data
brain stem death is a clinical syndrome defined by the absence of reflexes with pathways through the brain stem the “ stalk ” of the brain which connects the spinal cord to the mid brain cerebellum and cerebral hemispheres in a deeply comatose ventilator dependent patient identification of this state carries a very grave prognosis for survival cessation of heartbeat often occurs within a few days although it may continue for weeks or even months if intensive support is maintained in the united kingdom the formal diagnosis of brain stem death by the procedure laid down in the official code of practice permits the diagnosis and certification of death on the premise that a person is dead when consciousness and the ability to breathe are permanently lost regardless of continuing life in the body and parts of the brain and that death of the brain stem alone is sufficient to produce this state this concept of brain stem death is also accepted as grounds for pronouncing death for legal purposes in india and trinidad tobago elsewhere in the world the concept upon which the certification of death on neurological grounds is based is that of permanent cessation of all function in all parts of the brain whole brain death with which the reductionist united kingdom concept should not be confused the united states president s council on bioethics made it clear in its white paper of december 2008 that the united kingdom concept and clinical criteria are not considered sufficient for the diagnosis of death in the united states of america
a brain stem tumor is a tumor in the part of the brain that connects to the spinal cord the brain stem
brain stimulation reward bsr is a phenomenon in which direct stimulation of regions of the brain through either electrical or chemical means is rewarding and can serve as an operant reinforcer the stimulation activates the reward system and establishes response habits similar to those established by natural rewards such as food and water bsr experiments soon demonstrated that stimulation of the lateral hypothalamus and other regions of the brain associated with natural reward was both rewarding as well as drive inducing electrical brain stimulation and intracranial drug injections are among the most powerful rewards because they activate the reward circuitry directly rather than through the peripheral nerves bsr has been found in all vertebrates tested including humans and it has provided a useful tool for understanding how natural rewards are processed by the brain as well as the anatomical structures and the neurochemistry associated with the brain s reward system intracranial self stimulation icss is the operant conditioning method used to create the bsr response
a brain tumor or intracranial neoplasm occurs when abnormal cells form within the brain there are two main types of tumors malignant or cancerous tumors and benign tumors cancerous tumors can be divided into primary tumors that start within the brain and secondary tumors that have spread from somewhere else known as brain metastasis tumors all types of brain tumors may produce symptoms that vary depending on the part of the brain involved these symptoms may include headaches seizures problem with vision vomiting and mental changes the headache is classically worse in the morning and goes away with vomiting more specific problems may include difficulty in walking speaking and with sensation as the disease progresses unconsciousness may occur the cause of most brain tumors is unknown uncommon risk factors include inherited neurofibromatosis exposure to vinyl chloride epstein – barr virus and ionizing radiation the evidence for mobile phones is not clear the most common types of primary tumors in adults are meningiomas usually benign and astrocytomas such as glioblastomas in children the most common type is a malignant medulloblastoma diagnosis is usually by medical examination along with computed tomography or magnetic resonance imaging this is then often confirmed by a biopsy based on the findings the tumors are divided into different grades of severity treatment may include some combination of surgery radiation therapy and chemotherapy anticonvulsant medication may be needed if seizures occur dexamethasone and furosemide may be used to decrease swelling around the tumor some tumors grow gradually requiring only monitoring and possibly needing no further intervention treatments that use a person s immune system are being studied outcome varies considerably depending on the type of tumor and how far it has spread at diagnosis glioblastomas usually have poor outcomes while meningiomas usually have good outcomes the average five year survival rate for brain cancer in the united states is 33 secondary or metastatic brain tumors are more common than primary brain tumors with about half of metastases coming from lung cancer primary brain tumors occur in around 250 000 people a year globally making up less than 2 of cancers in children younger than 15 brain tumors are second only to acute lymphoblastic leukemia as a cause of cancer in australia the average economic cost of a case of brain cancer is 1 9 million the greatest of any type of cancer
brainerd diarrhea is a sudden onset watery explosive diarrhea that lasts for months and does not respond to antibiotics the cause of brainerd diarrhea is unknown brainerd diarrhea was first described in brainerd minnesota in 1983 it has been associated with the consumption of raw milk and untreated water of the ten outbreaks reported since 1983 nine have been in the u s the characteristics of each outbreak have been similar to that caused by an infectious agent although a comparatively large outbreak 117 patients occurred in 1996 in fannin county texas the largest outbreak 122 patients was the original one in brainerd mn there have been no secondary cases reported in any of the outbreaks suggesting that the causative agent cannot be passed from person to person but boiling water appears to inactivate the brainerd agent although there is no treatment available the disease does appear to resolve itself although this process takes months if not years
a brainstem glioma is a cancerous glioma tumor in the brainstem around 75 are diagnosed in children and young adults under the age of twenty but have been known to affect older adults as well brainstem gliomas start in the brain or spinal cord tissue and typically spread throughout the nervous system
a brainstem stroke syndrome is a condition involving a stroke of the brainstem because of their location they often involve impairment both of the cranial nuclei and of the long tracts a person may have vertigo dizziness and severe imbalance without the hallmark of most strokes – weakness on one side of the body the symptoms of vertigo dizziness or imbalance usually occur together dizziness alone is not a sign of stroke brainstem stroke can also cause diplopia slurred speech and decreased level of consciousness a more serious outcome is locked in syndrome
in the automotive industry brake by wire technology is the ability to control brakes through electrical means it can be designed to supplement ordinary service brakes or it can be a standalone brake system this technology is widely used on all hybrid and battery electric vehicles including the toyota prius brake by wire is also common in the form of the electric park brake which is now widely used on mainstream vehicles the technology replaces traditional components such as the pumps hoses fluids belts and vacuum servos and master cylinders with electronic sensors and actuators drive by wire technology in automotive industry replaces the traditional mechanical and hydraulic control systems with electronic control systems using electromechanical actuators and human machine interfaces such as pedal and steering feel emulators some x by wire technologies have been already installed on commercial vehicles such as steer by wire and throttle by wire brake by wire technology has been widely commercialized with the introduction of battery electric vehicles and hybrid vehicles the most widely used application by toyota in the high volume prius was preceded by the gm ev 1 the rav 4 ev and other evs where the technology is required for regenerative braking ford general motors and most other manufacturers use the same general design with the exception of honda who designed a notably different design
branch retinal artery occlusion brao is a rare retinal vascular disorder in which one of the branches of central retinal artery is obstructed
branch retinal vein occlusion brvo is a common retinal vascular disease of the elderly it is caused by the occlusion of one of the branches of central retinal vein
a branchial cleft cyst is a congenital epithelial cyst that arises on the lateral part of the neck usually due to failure of obliteration of the second branchial cleft or failure of fusion of the second and third branchial arches in embryonic development less commonly the cysts can develop from the first third or fourth clefts
branchio oculo facial syndrome bofs is a disease that arises from a mutation in the tfap 2 a gene it is a rare autosomal dominant disorder that starts to affect a child s development before birth symptoms of this condition include skin abnormalities on the neck deformities of the ears and eyes and other distinctive facial features such a cleft lip along with slow growth mental retardation and premature graying of hair
branchio oto renal syndrome bor also known as branchiootorenal syndrome or bor syndrome is an autosomal dominant genetic disorder involving the kidneys ears and neck it often has also been described as melnick fraser syndrome
brand awareness is a key consideration in consumer behaviour and advertising strategy brand awareness refers to the extent to which customers are able to recall or recognise a brand the consumer s ability to recognise a brand is central to purchasing decision making awareness does not necessarily mean that the consumer must be able to recall a specific brand name but he or she must be able to recall enough distinguishing features for purchasing to proceed for instance if a consumer asks her friend to buy her some gum in a blue pack the friend would be expected to know which gum to buy even though neither friend can recall the precise brand name at the time
a brand blunder is an error associated with the branding of a product especially a new product in a new market reasons for such slips include the lack of understanding of the language culture and consumer attitudes in the new market there are numerous examples of brand blunders in marketing history there are also numerous urban legends surrounding brand blunders where there is little evidence of an actual blunder
braxton hicks contractions also known as prodromal labor or practice contractions or false labor are sporadic uterine contractions that sometimes start around six weeks into a pregnancy however they are not usually felt until the second trimester or third trimester of pregnancy
braxy is an inflammatory disease in the abomasal lining of sheep caused by the bacterium clostridium septicum aka bacillus septicus followed by rapid death braxy is often brought on by a change from succulent food to dry or icy food it is usually seen in young sheep in particular those not protected with a clostridial vaccine the mutton affected with this disease can also be referred to as braxy a vaccine against braxy was developed by prof john russell greig at the moredun research institute in scotland
brazilian hemorrhagic fever bzhf is an infectious disease caused by the sabiá virus an arenavirus the sabiá virus is one of the arenoviruses from south america to cause hemorrhagic fever it shares a common progenitor with the junin virus machupo virus tacaribe virus and guanarito virus it is an enveloped rna virus and is highly infectious and lethal very little is known about this disease but it is thought to have be transmitted by the excreta of rodents there have only been three documented infections of the sabiá virus only one of which occurred naturally and the other two cases occurred in the clinical setting the only naturally occurring case was in 1990 when a female agricultural engineer who was staying in the neighborhood of jardim sabiá near são paulo brazil contracted the disease she presented with hemorrhagic fever and died her autopsy showed liver necrosis a virologist who was studying the woman s disease contracted the virus but survived ribavirin was not given in these first two cases four years later in 1994 a researcher was exposed to the virus in a level 3 biohazard facility at yale university when a centrifuge bottle cracked leaked and released aerosolized virus particle he was successfully treated with ribavirin ribavirin is thought to be effective in treating the illness similar to other arenaviruses compared to the patients who did not receive ribavirin the patient who was treated with it had a shorter and less severe clinical course symptomatic control such as fluids to address dehydration and bleeding may also be required the sabiá virus is a biosafety level 4 pathogen this virus has also been implicated as a means for bioterrorism as it can be spread through aerosols
brazilian purpuric fever bpf is an illness of children caused by the bacterium haemophilus influenzae biogroup aegyptius which is ultimately fatal due to sepsis bpf was first recognized in the são paulo state of brazil in 1984 at this time young children between the ages of 3 months and 10 years were contracting a strange illness which was characterized by high fever and purpuric lesions on the body these cases were all fatal and originally thought to be due to meningitis it was not until the autopsies were conducted that the cause of these deaths was confirmed to be infection by h influenzae aegyptius although bpf was thought to be confined to brazil other cases occurred in australia and the united states during 1984 – 1990
breach of contract is a legal cause of action in which a binding agreement or bargained for exchange is not honored by one or more of the parties to the contract by non performance or interference with the other party s performance if the party does not fulfill his contractual promise or has given information to the other party that he will not perform his duty as mentioned in the contract or if by his action and conduct he seems to be unable to perform the contract he is said to breach the contract breach of contract is a type of civil wrong
in locksmithing a break in the pins is a separation in one or more sections of the pin used to encode the lock for a specific key or set of keys in a master keying system
a breakthrough infection is an infection caused by the live virus in a vaccine or simply a vaccinated individual becoming sick with the same illness that the vaccine is meant to prevent often the infection in the vaccinated individual is milder than if contracted naturally a breakthrough infection can be especially dangerous in locations where herd immunity exists there are many theories which attempt to explain the causes of breakthrough infections such as antibody interference or vaccine compromise due to mishandling
breast atrophy is the normal or spontaneous atrophy or shrinkage of the breasts breast atrophy commonly occurs in women during menopause when estrogen levels decrease it can also be caused by hypoestrogenism and or hyperandrogenism in women in general such as in antiestrogen treatment for breast cancer in polycystic ovary syndrome pcos and in malnutrition such as that associated with eating disorders like anorexia nervosa or with chronic disease it can also be an effect of weight loss in the treatment of gynecomastia in males and macromastia in women and in hormone replacement therapy hrt for trans men breast atrophy may be a desired effect examples of treatment options for breast atrophy depending on the situation when appropriate can include estrogens antiandrogens and proper nutrition or weight gain
breast cancer is cancer that develops from breast tissue signs of breast cancer may include a lump in the breast a change in breast shape dimpling of the skin fluid coming from the nipple or a red scaly patch of skin in those with distant spread of the disease there may be bone pain swollen lymph nodes shortness of breath or yellow skin risk factors for developing breast cancer include being female obesity lack of physical exercise drinking alcohol hormone replacement therapy during menopause ionizing radiation early age at first menstruation having children late or not at all older age and family history about 5 – 10 of cases are due to genes inherited from a person s parents including brca 1 and brca 2 among others breast cancer most commonly develops in cells from the lining of milk ducts and the lobules that supply the ducts with milk cancers developing from the ducts are known as ductal carcinomas while those developing from lobules are known as lobular carcinomas in addition there are more than 18 other sub types of breast cancer some cancers such as ductal carcinoma in situ develop from pre invasive lesions the diagnosis of breast cancer is confirmed by taking a biopsy of the concerning lump once the diagnosis is made further tests are done to determine if the cancer has spread beyond the breast and which treatments it may respond to the balance of benefits versus harms of breast cancer screening is controversial a 2013 cochrane review stated that it is unclear if mammographic screening does more good or harm a 2009 review for the us preventive services task force found evidence of benefit in those 40 to 70 years of age and the organization recommends screening every two years in women 50 to 74 years old the medications tamoxifen or raloxifene may be used in an effort to prevent breast cancer in those who are at high risk of developing it surgical removal of both breasts is another preventative measure in some high risk women in those who have been diagnosed with cancer a number of treatments may be used including surgery radiation therapy chemotherapy hormonal therapy and targeted therapy types of surgery vary from breast conserving surgery to mastectomy breast reconstruction may take place at the time of surgery or at a later date in those in whom the cancer has spread to other parts of the body treatments are mostly aimed at improving quality of life and comfort outcomes for breast cancer vary depending on the cancer type extent of disease and person s age survival rates in the developed world are high with between 80 and 90 of those in england and the united states alive for at least 5 years in developing countries survival rates are poorer worldwide breast cancer is the leading type of cancer in women accounting for 25 of all cases in 2012 it resulted in 1 68 million cases and 522 000 deaths it is more common in developed countries and is more than 100 times more common in women than in men
a breast cyst is a fluid filled sac within the breast one breast can have one or more breast cysts they are often described as round or oval lumps with distinct edges in texture a breast cyst usually feels like a soft grape or a water filled balloon but sometimes a breast cyst feels firm breast cysts can be painful and may be worrisome but are generally benign they are most common in pre menopausal women in their 30 s or 40 s they usually disappear after menopause but may persist or reappear when using hormone therapy they are also common in adolescents breast cysts can be part of fibrocystic disease the pain and swelling is usually worse in the second half of the menstrual cycle or during pregnancy treating breast cysts is usually not necessary unless they are painful or cause discomfort in most cases the discomfort they cause may be alleviated by draining the fluid from the cyst the cysts form as a result of the growth of the milk glands and their size may range from smaller than a pea to larger than a ping pong ball small cysts cannot be felt during a physical examination and some large cysts feel like lumps however most cysts regardless of their size cannot be identified during physical exams breast cysts are not to be confused with milk cysts galactoceles which usually appear during weaning
breast diseases can be classified either with disorders of the integument or disorders of the reproductive system a majority of breast diseases are noncancerous breast awareness is a goal of the breast health movement rather than promoting the largely ineffective formally structured breast self examinations breast awareness promotes informal familiarity with the normal state of a woman s breasts
breast eczema also known as nipple eczema may affect the nipples areolae or surrounding skin with eczema of the nipples being of the moist type with oozing and crusting in which painful fissuring is frequently seen especially in nursing mothers it will often occur in pregnancy even without breast feeding persisting eczema of the nipple in the middle aged and elderly needs to be discussed with a doctor as a rare type of breast cancer called paget s disease can cause these symptoms
breast engorgement occurs in the mammary glands due to expansion and pressure exerted by the synthesis and storage of breast milk engorgement usually happens when the breasts switch from colostrum to mature milk often referred to as when the milk comes in however engorgement can also happen later if lactating women miss several nursings and not enough milk is expressed from the breasts it can be exacerbated by insufficient breastfeeding and or blocked milk ducts when engorged the breasts may swell throb and cause mild to extreme pain engorgement may lead to mastitis inflammation of the breast and untreated engorgement puts pressure on the milk ducts often causing a plugged duct the woman will often feel a lump in one part of the breast and the skin in that area may be red and or warm if it continues unchecked the plugged duct can become a breast infection at which point she may have fever or flu like symptoms
breast hematoma is a collection of blood within the breast it arises from internal bleeding hemorrhage and may arise due to trauma breast injury or surgery or due to a non traumatic cause
hypertrophy of the breast macromastia and gigantomastia is a rare medical condition of the breast connective tissues the indication is a breast weight that exceeds approximately 3 of the total body weight there are varying definitions of what is considered to be excessive breast tissue that is the expected breast tissue plus extraordinary breast tissue ranging from as little as 0 6 kilograms 1 3 lb up to 2 5 kilograms 5 5 lb with most physicians defining macromastia as excessive tissue of over 1 5 kilograms 3 3 lb some resources distinguish between macromastia greek macro large mastos breast where excessive tissue is less than 2 5 kg and gigantomastia greek gigantikos giant where excessive tissue is more than 2 5 kg the enlargement can cause muscular discomfort and over stretching of the skin envelope which can lead in some cases to ulceration hypertrophy of the breast tissues might be caused by increased histologic sensitivity to certain hormones such as female sex hormones prolactin and growth factors or an abnormally elevated hormone s level in the blood or both breast hypertrophy is a benign progressive enlargement which can occur in both breasts bilateral or only in one breast unilateral it was first scientifically described in 1648
breast lumps are localized swellings that feel different from the surrounding breast tissue it is a symptom sign for a variety of conditions as approximately 10 of breast lumps ultimately lead to a diagnosis of breast cancer it is important for women with a breast lump to receive appropriate evaluation
breast pain also known as breast tenderness mastodynia mammalgia and mastalgia from the greek μαστός mastos breast and ἄλγος algos pain is a medical symptom pain and discomfort may range from minor to severely incapacitating breast pain during lactation or after weaning is not included into this definition but is usually classified as breast engorgement or mastitis
breastfeeding difficulties refers to problems that arise from breastfeeding the feeding of an infant or young child with milk from a woman s breasts although babies have a sucking reflex that enables them to suck and swallow milk and although human breast milk is usually the best source of nourishment for human infants there are circumstances under which breastfeeding can be problematic or even in rare instances contraindicated difficulties can arise both in connection with the act of breastfeeding and with the health of the nursing infant
breath holding spells are the occurrence of episodic apnea in children possibly associated with loss of consciousness and changes in postural tone breath holding spells occur in approximately 5 of the population with equal distribution between males and females they are most common in children between 6 and 18 months and usually not present after 5 years of age they are unusual before 6 months of age a positive family history can be elicited in 25 of cases they may be confused with a seizure disorder they are sometimes observed in response to frustration during disciplinary conflict
breathability is the ability of a fabric to allow moisture vapor to be transmitted through the material
a breech birth occurs when a baby is born bottom first instead of head first around 3 5 of pregnant women at term 37 – 40 weeks pregnant will have a breech baby most babies in the breech position are born by a caesarean section because it is seen as safer than being born vaginally as most breech babies are delivered by caesarean section in developed countries doctors and midwives may lose the skills required to safely assist a women giving birth to a breech baby vaginally delivering all breech babies by caesarean section in developing countries may be very difficult to implement or even impossible as there are not always resources available to provide this service
in cellular automata such as conway s game of life a breeder is a pattern that exhibits quadratic growth by generating multiple copies of a secondary pattern each of which then generates multiple copies of a tertiary pattern
brenner tumors are an uncommon subtype of the surface epithelial stromal tumor group of ovarian neoplasms the majority are benign but some can be malignant they are most frequently found incidentally on pelvic examination or at laparotomy brenner tumours very rarely can occur in other locations including the testes
the breskens pocket was a pocket of fortified german resistance against the canadian first army in the battle of the scheldt during the second world war it was chiefly situated on the southern shore of the scheldt estuary in the southern netherlands near the belgian border it was named after the town of breskens which was later freed from german occupation during operation switchback
brewer infarcts are a histological finding found in renal disease they can indicate pyelonephritis they are named after george emerson brewer
bride price best called bridewealth also known as bride token is money property or other form of wealth paid by a groom or his family to the parents of the woman he has just married or is just about to marry bride price can be compared to dowry which is paid to the groom or used by the bride to help establish the new household and dower which is property settled on the bride herself by the groom at the time of marriage some cultures may practice both dowry and bride price simultaneously many cultures practiced bride pricing prior to existing records
the bridge of las tres fuentes the three fountains is a bridge pattern by disciples of gustave eiffel originally constructed in iron in the 20 th century it was covered with concrete it is near gil marquez almonaster la real
the bridge pattern is a design pattern used in software engineering which is meant to decouple an abstraction from its implementation so that the two can vary independently the bridge uses encapsulation aggregation and can use inheritance to separate responsibilities into different classes when a class varies often the features of object oriented programming become very useful because changes to a program s code can be made easily with minimal prior knowledge about the program the bridge pattern is useful when both the class and what it does vary often the class itself can be thought of as the abstraction and what the class can do as the implementation the bridge pattern can also be thought of as two layers of abstraction when there is only one fixed implementation this pattern is known as the pimpl idiom in the c world the bridge pattern is often confused with the adapter pattern in fact the bridge pattern is often implemented using the class adapter pattern e g in the java code below variant the implementation can be decoupled even more by deferring the presence of the implementation to the point where the abstraction is utilized
bridging loss is the loss at a given frequency that results when an impedance is connected across a transmission line it is expressed as the ratio in decibels of the signal power delivered to a given point in a system downstream from the bridging point prior to bridging to the signal power delivered to the given point after bridging source from federal standard 1037 c and from mil std 188
the bridgman effect named after p w bridgman also called the internal peltier effect is a phenomenon that occurs when an electric current passes through an anisotropic crystal there is an absorption or liberation of heat because of the non uniformity in current distribution
brief reactive psychosis referred to in the dsm iv tr as brief psychotic disorder with marked stressor s is the psychiatric term for psychosis which can be triggered by an extremely stressful event in the life of an individual typically such brief psychoses last from a day to a month only with the delusions speech disorders and hallucinations eventually yielding to a return to normal functioning
bright s disease is a historical classification of kidney diseases that would be described in modern medicine as acute or chronic nephritis it was characterized by edema the presence of albumin in the urine and was frequently accompanied by high blood pressure hypertension
brill – zinser disease is a delayed relapse of epidemic typhus caused by rickettsia prowazekii after a patient contracts epidemic typhus from the fecal matter of an infected louse pediculus humanus the rickettsia can remain latent and reactivate months or years later with symptoms similar to or even identical to the original attack of typhus including a maculopapular rash this reactivation event can then be transmitted to other individuals through fecal matter of the louse vector and form the focus for a new epidemic of typhus
bristleworm stings are a cutaneous condition caused by contact with bristleworms in which an allergic or irritant reaction may result
the british agricultural revolution was the unprecedented increase in agricultural production in britain due to increases in labour and land productivity between the mid 17 th and late 19 th centuries agricultural output grew faster than the population over the century to 1770 and thereafter productivity remained among the highest in the world this increase in the food supply contributed to the rapid growth of population in england and wales from 5 5 million in 1700 to over 9 million by 1801 though domestic production gave way increasingly to food imports in the nineteenth century as population more than tripled to over 32 million the rise in productivity accelerated the decline of the agricultural share of the labour force adding to the urban workforce on which industrialization depended the agricultural revolution has therefore been cited as a cause of the industrial revolution however historians continue to dispute when exactly such a revolution took place and of what it consisted rather than a single event g e mingay states that there were a profusion of agricultural revolutions one for two centuries before 1750 another emphasising the century after 1650 a third for the period 1750 1880 and a fourth for the middle decades of the nineteenth century this has led more recent historians to argue that any general statements about the agricultural revolution are difficult to sustain one important change in farming methods was the move in crop rotation to turnips and clover in place of fallow turnips can be grown in winter and are deep rooted allowing them to gather minerals unavailable to shallow rooted crops clover fixes nitrogen from the atmosphere into a form of fertiliser this permitted the intensive arable cultivation of light soils on enclosed farms and provided fodder to support increased livestock numbers whose manure added further to soil fertility
the british invasion was a phenomenon that occurred in the mid 1960 s when rock and pop music acts from the united kingdom as well as other aspects of british culture became popular in the united states and significant to the rising counterculture on both sides of the atlantic pop and rock groups such as the beatles the dave clark five the kinks the rolling stones herman s hermits the animals and the who were at the forefront of the invasion
the british pediatric association classification of diseases is a system of diagnostic codes used for pediatrics an extension to icd 9 was published in 1979 an extension to icd 10 has also been published it is the basis for the u s centers for disease control and prevention s six digit codes for reportable congenital conditions these are also known as the cdc bpa codes this system is in turn is the basis for the texas disease index
the british debate over veils began in october 2006 when the mp and government minister jack straw wrote in his local newspaper the lancashire evening telegraph that while he did not want to be prescriptive he preferred talking to women who did not wear a niqab face veil as he could see their face and asked women who were wearing such items to remove them when they spoke to him making clear that they could decline his request and that a female member of staff was in the room straw said he told the newspaper this information to open a debate on the subject and not because of the upcoming deputy leader election in the labour party straw was foreign secretary at the time of the iraq war and since 1979 had been the member of parliament for the constituency of blackburn where at least one quarter of the population are muslim straw later stated that he would like to see the veil abolished altogether adding that he was worried about implications of separateness straw s views were met with a mixed response with some agreeing to the idea of a debate some arguing that muslim women should not wear veils in the united kingdom and some such as the newspaper the daily express calling for the veil to be banned others were opposed to straw s intervention and some accused him of encouraging prejudice in 2010 jack straw publicly apologised over his 2006 comments stating if i had realised the scale of publicity that they his comments received in october 2006 i wouldn ’ t have made them and i am sorry that it has caused problems and i offer that apology
broadcast encryption is the cryptographic problem of delivering encrypted content e g tv programs or data on dvds over a broadcast channel in such a way that only qualified users e g subscribers who have paid their fees or dvd players conforming to a specification can decrypt the content the challenge arises from the requirement that the set of qualified users can change in each broadcast emission and therefore revocation of individual users or user groups should be possible using broadcast transmissions only and without affecting any remaining users as efficient revocation is the primary objective of broadcast encryption solutions are also referred to as revocation schemes rather than directly encrypting the content for qualified users broadcast encryption schemes distribute keying information that allows qualified users to reconstruct the content encryption key whereas revoked users find insufficient information to recover the key the typical setting considered is that of a unidirectional broadcaster and stateless users i e users do not keep bookmarking of previous messages by the broadcaster which is especially challenging in contrast the scenario where users are supported with a bi directional communication link with the broadcaster and thus can more easily maintain their state and where users are not only dynamically revoked but also added joined is often referred to as multicast encryption the problem of practical broadcast encryption has first been formally studied by amos fiat and moni naor in 1994 since then several solutions have been described in the literature including combinatorial constructions one time revocation schemes based on secret sharing techniques and tree based constructions in general they offer various trade offs between the increase in the size of the broadcast the number of keys that each user needs to store and the feasibility of an unqualified user or a collusion of unqualified users being able to decrypt the content luby and staddon have used a combinatorial approach to study the trade offs for some general classes of broadcast encryption algorithms a particularly efficient tree based construction is the subset difference scheme which is derived from a class of so called subset cover schemes the subset difference scheme is notably implemented in the aacs for hd dvd and blu ray disc encryption a rather simple broadcast encryption scheme is used for the css for dvd encryption the problem of rogue users sharing their decryption keys or the decrypted content with unqualified users is mathematically insoluble traitor tracing algorithms aim to minimize the damage by retroactively identifying the user or users who leaked their keys so that punitive measures legal or otherwise may be undertaken in practice pay tv systems often employ set top boxes with tamper resistant smart cards that impose physical restraints on a user learning their own decryption keys some broadcast encryption schemes such as aacs also provide tracing capabilities
broadcast radiation is the accumulation of broadcast and multicast traffic on a computer network extreme amounts of broadcast traffic constitute a broadcast storm a broadcast storm can consume sufficient network resources so as to render the network unable to transport normal traffic a packet that induces such a storm is occasionally nicknamed a chernobyl packet
broadening top is technical analysis chart pattern describing trends of stocks commodities currencies and other assets
a brodie abscess is a subacute osteomyelitis which may persist for years before converting to a frank osteomyelitis classically this may present after conversion as a draining abscess extending from the tibia out through the shin occasionally acute osteomyelitis may be contained to a localized area and walled off by fibrous and granulation tissue this is termed as brodie s abscess most frequent causative organism is staphylococcus aureus
brody myopathy is a genetic disease it can be associated with atp 2 a 1 it was characterized in 1969
the broken escalator phenomenon also known as the walker effect is the sensation of losing balance or dizziness reported by some people when stepping onto an escalator which is not working it is said that there is a brief odd sensation of imbalance despite full awareness that the escalator is not going to move it has been shown that this effect causes people to step inappropriately fast onto a moving platform that is no longer moving even when this is obvious to the participant even though subjects are fully aware that the platform or escalator is not moving now parts of their brains still act on previous experience gained when it was moving and so misjudge how to step onto it thus this effect demonstrates the separateness of the declarative and procedural functions of the brain
bromine number is the amount of bromine in grams absorbed by 100 grams 3 5 oz of a sample the number indicates the degree of unsaturation the bromine number is useful as a measure of aliphatic unsaturation in gasoline samples the california arb in its motor vehicle fuels compliance assistance program indicated that every unit of bromine number is equivalent to twice the percentage point of olefin content in gasoline so a gasoline with bromine number 30 would have an olefin content of not more than 15 vol one refinery compiled a year s worth of data on bromine number and the corresponding olefin content of gasoline the data showed that the bromine number of gasoline is about 2 4 times the olefin content a gasoline with bromine number of 30 would then have an olefin content of about 12 5 percent by volume which is slightly lower than arb s assumption but still is higher than the carfg maximum limit of 10 percent by volume the bromine number is usually determined by electrochemical titration where bromine is generated in situ with the redox process of potassium bromide and bromate in an acidic solution using a mercury catalyst to ensure the complete bromination of all olefins it is similar to i 2 value and useful for oils containing fatty acids with conjugated system of double bonds it can be calculated as an equivalent i 2 value by multiplying result by atomic weight of i 2 divided by atomic weight of br 2 that is 126 9 79 9
bromism is the syndrome which results from the long term consumption of bromine usually through bromide based sedatives such as potassium bromide and lithium bromide bromism was once a very common disorder being responsible for 5 to 10 of psychiatric hospital admissions bromism is now an uncommon disorder because bromide was withdrawn from clinical use in many countries and was severely restricted in others high levels of bromide chronically impair the membrane of neurons which progressively impairs neuronal transmission leading to toxicity known as bromism bromide has an elimination half life of 9 to 12 days which can lead to excessive accumulation doses of 0 5 to 1 gram per day of bromide can lead to bromism historically the therapeutic dose of bromide is about 3 to 5 grams of bromide thus explaining why chronic toxicity bromism was once so common while significant and sometimes serious disturbances occur to neurologic psychiatric dermatological and gastrointestinal functions death is rare from bromism bromide is still occasionally used in for epilepsy treatments in some countries bromism is caused by a neurotoxic effect on the brain which results in somnolence psychosis seizures and delirium bromism has also been caused by excessive soda consumption due to the presence of brominated vegetable oil leading to headache fatigue ataxia memory loss and eventually inability to walk in one case
bromoderma also known as bromoderma tuberosum is a dermatological condition characterized by an eruption of papules and pustules on the skin it is caused by hypersensitivity to bromides such as those found in certain drugs there is at least one reported case of bromoderma caused by excessive consumption of a soft drink containing brominated vegetable oil
bronchiectasis is a disease in which there is permanent enlargement of parts of the airways of the lung symptoms typically include a chronic cough productive of mucus other symptoms include shortness of breath coughing up blood and chest pain wheezing and nail clubbing may also occur those with the disease often get frequent lung infections bronchiectasis may result from a number of infective and acquired causes including pneumonia tuberculosis immune system problems and cystic fibrosis cystic fibrosis eventually results in severe bronchiectasis in nearly all cases the cause in 10 50 of those without cystic fibrosis is unknown the mechanism of disease is breakdown of the airways due to an excessive inflammatory response involved bronchi become enlarged and thus less able to clear secretions these secretions increase the amount of bacteria in the lungs result in airway blockage and further breakdown of the airways it is classified as an obstructive lung disease along with chronic obstructive pulmonary disease and asthma the diagnosis is suspect based on a person s symptoms and confirmed using computed tomography sputum cultures may be useful to determine treatment in those who have acute worsening and at least once a year worsening may occur due to infection and in these cases antibiotics are recommended typical antibiotics used include amoxicillin erythromycin or doxycycline antibiotics may also be used to prevent worsening of disease airway clearance techniques a type of physiotherapy are recommended medications to dilate the airways may be useful in some but the evidence is not very good the use of inhaled steroids have not been found to be useful surgery while commonly done has not been well studied lung transplantation may be an option in those with very severe disease while the disease may cause significant health problems most people with the disease do well the disease affects between 1 per 1000 to 1 per 250 000 adults the disease is more common in women and increases as people age it became less common in since the 1950 s with the introduction of antibiotics it is more common among certain ethnic groups such as indigenous people it was first described by rene laennec in 1819 the economic costs in the united states are estimated at 630 million per year
bronchiolitis is inflammation of the bronchioles the smallest air passages of the lungs it usually occurs in children less than two years of age with the majority being aged between three and six months it presents with coughing wheezing and shortness of breath which can cause some children difficulty in feeding this inflammation is usually caused by respiratory syncytial virus 70 of cases and is much more common in the winter months treatment is typically supportive with oxygen monitoring fluid and nutrition perhaps by gastric tube or intravenously the use of nebulized hypertonic saline is controversial with some reviews finding benefits and other not there is insufficient evidence to support treatment with antibiotics surfactant chest physiotherapy or bronchodilators nebulized epinephrine bronchiolitis is common with up to one third of children being affected in their first year of life
bronchiolitis obliterans bo is a disease that results in obstruction of the smallest airways of the lungs bronchioles due to inflammation symptoms include a dry cough shortness of breath wheezing and feeling tired these symptoms generally get worse over weeks to months it is not related to organizing pneumonia causes include breathing in toxic fumes respiratory infections connective tissue disorder or following a bone marrow or heart lung transplant symptoms may not occur until two to eight weeks following toxic exposure or infection the underlying mechanism involves inflammation that results in scar tissue formation diagnosis is by ct scan pulmonary function tests or lung biopsy a chest x ray is often normal while the disease is not reversible treatments can slow further worsening this may include the use of corticosteroids or immunosuppressive medication a lung transplant maybe tried outcomes are often poor with most people dying in months to years bronchiolitis obliterans is rare in the general population it affects about 75 of people by ten years following a lung transplant and up to 10 of people who have received a bone marrow transplant from someone else the condition was first clearly described in 1981 prior descriptions occurred as early as 1956
bronchiolitis obliterans organizing pneumonia boop also known as cryptogenic organizing pneumonia is a form of non infectious pneumonia more specifically boop is an inflammation of the bronchioles bronchiolitis and surrounding tissue in the lungs it is often a complication of an existing chronic inflammatory disease such as rheumatoid arthritis dermatomyositis or it can be a side effect of certain medications such as amiodarone boop was first described by gary epler in 1985 some authors have recommended the use of an alternate name cryptogenic organizing pneumonia cop to reduce confusion with bronchiolitis obliterans a distinct and unrelated disease the clinical features and radiological imaging resemble infectious pneumonia however diagnosis is suspected after there is no response to multiple antibiotics and blood and sputum cultures are negative for organisms
bronchitis is inflammation of the bronchi large and medium sized airways in the lungs symptoms include coughing up mucus wheezing shortness of breath and chest discomfort bronchitis is divided into two types acute and chronic acute bronchitis is also known as a chest cold acute bronchitis usually has a cough that lasts around three weeks in more than 90 of cases the cause is a viral infection these viruses may be spread through the air when people cough or by direct contact risk factors include exposure to tobacco smoke dust and other air pollution a small number of cases are due to high levels of air pollution or bacteria such as mycoplasma pneumoniae or bordetella pertussis treatment of acute bronchitis typically involves rest paracetamol acetaminophen and nsaids to help with the fever chronic bronchitis is defined as a productive cough that lasts for three months or more per year for at least two years most people with chronic bronchitis have chronic obstructive pulmonary disease copd tobacco smoking is the most common cause with a number of other factors such as air pollution and genetics playing a smaller role treatments include quitting smoking vaccinations rehabilitation and often inhaled bronchodilators and steroids some people may benefit from long term oxygen therapy or lung transplantation acute bronchitis is one of the most common diseases about 5 of adults are affected and about 6 of children have at least one episode a year in 2010 copd affects 329 million people or nearly 5 of the global population in 2013 it resulted in 2 9 million deaths up from 2 4 million deaths in 1990
bronchoconstriction is the constriction of the airways in the lungs due to the tightening of surrounding smooth muscle with consequent coughing wheezing and shortness of breath
bronchodilation is the dilation of the airways in the lungs due to the relaxation of surrounding smooth muscle it is the opposite of bronchoconstriction
bronchogenic cysts are small solitary cysts or sinuses most typically located in the region of the suprasternal notch or over the manubrium
bronchomalacia is a term for weak cartilage in the walls of the bronchial tubes often occurring in children under six months bronchomalacia means ‘ floppiness ’ of some part of the bronchi patients present with noisy breathing and or wheezing there is collapse of a main stem bronchus on exhalation if the trachea is also involved the term tracheobronchomalacia tbm is used if only the upper airway the trachea is involved it is called tracheomalacia tm there are two types of bronchomalacia primary bronchomalacia is due to a deficiency in the cartilaginous rings secondary bronchomalacia may occur by extrinsic compression from an enlarged vessel a vascular ring or a bronchogenic cyst though uncommon idiopathic of unknown cause tracheobronchomalacia has been described in older adults
a bronchopleural fistula bpf is a fistula between the pleural space and the lung it can develop following pneumonectomy post traumatically or with certain types of infection it may also develop when large airways are in communication with the pleural space following a large pneumothorax or other loss of pleural negative pressure especially during positive pressure mechanical ventilation on imaging the diagnosis is suspected indirectly on radiograph increased gas in the pneumonectomy operative bed or new gas within a loculated effusion are highly suggestive of the diagnosis infectious causes include tuberculosis actinomyces israelii nocardia and blastomyces dermatitidis malignancy and trauma can also result in the abnormal communication
bronchopulmonary dysplasia bpd formerly chronic lung disease of infancy is a chronic lung disorder of infants and children first described in 1967 it is more common in infants with low birth weight and those who receive prolonged mechanical ventilation to treat respiratory distress syndrome rds it results in significant morbidity and mortality the definition of bpd has continued to evolve since then primarily due to changes in the population such as more survivors at earlier gestational ages and improved neonatal management including surfactant antenatal glucocorticoid therapy and less aggressive mechanical ventilation currently the description of bpd includes the grading of its severity into mild moderate and severe this correlates with the infant s maturity growth and overall severity of illness the new system offers a better description of underlying pulmonary disease and its severity
bronchospasm or a bronchial spasm is a sudden constriction of the muscles in the walls of the bronchioles it is caused by the release degranulation of substances from mast cells or basophils under the influence of anaphylatoxins it causes difficulty in breathing which can be very mild to severe bronchospasms appear as the feature of asthma chronic bronchitis and anaphylaxis bronchospasms are a possible side effect of some drugs pilocarpine which is used to treat illness resulting from the ingestion of deadly nightshade as well as other things beta blockers used to treat hypertension a paradoxical result of using laba drugs to treat copd and other drugs bronchospasms can present as a sign of giardiasis bronchospasms are one of several conditions associated with cold housing some of the things that can cause bronchospasms are consuming foods taking medicines allergic responses to insects and fluctuating hormone levels particularly in women a few of the more common allergens are foods such as eggs milk peanuts walnuts tree and other nuts fish especially shellfish soy and wheat insect bites and stings especially bee stings and other medicines especially penicillin and its derivatives the overactivity of the bronchioles muscle is a result of exposure to a stimulus which under normal circumstances would cause little or no response the resulting constriction and inflammation causes a narrowing of the airways and an increase in mucus production this reduces the amount of oxygen that is available to the individual causing breathlessness coughing and hypoxia bronchospasms are a serious potential complication of placing a breathing tube during general anesthesia when the airways spasm or constrict in response to the irritating stimulus of the breathing tube it is difficult to maintain the airway and the patient can become apneic
the brook rearrangement in organic chemistry is a rearrangement reaction in which an organosilyl group switches position with a hydroxyl proton over a carbon to oxygen covalent bond under the influence of a base it is named for the canadian chemist adrian gibbs brook 1924 – 2013 the reaction product is a silyl ether the brook rearrangement the silyl substituents can be aliphatic methyl or aromatic phenyl and the alcohol is secondary or tertiary with aliphatic or aryl groups the base is an amine sodium hydroxide an organolithium reagent or an alkali metal alloy such as sodium potassium when the reactant is a silylmethanol the reaction is a 1 2 brook rearrangement but rearrangements over larger carbon skeletons are also possible
brooke – fordyce syndrome is a condition characterized by multiple trichoepitheliomas
the brookings effect is a meteorological phenomenon that affects the southern coast of oregon in which dry adiabatic heating increases the temperature of a mass of air as it travels down slope it can occur at any time of the year producing temperatures near the chetco river mouth which are up to 40 ° f 22 ° c higher than without the air movement it is the same phenomenon as the santa ana winds on july 8 2008 brookings recorded a high temperature of 108 ° f 42 ° c at the airport this was not only the highest recorded temperature in the town s history but also the highest recorded in oregon on that day the crescent city airport approximately 30 miles south recorded a high temperature of 68 ° f 20 ° c that day temperatures in inland oregon throughout the willamette valley reached temperatures into the mid nineties the brookings effect remained very strong and localized until july 13 2008 when high temperatures in brookings dropped to 61 ° f 16 ° c which is about seven degrees lower than average during the month this report contradicts the common idea that the brookings effect is a chinook wind as moisture does not appear to play a role in the moist adiabatic cooling of air on the windward side of a mountain range followed by dry adiabatic warming on the lee side in contrast the brookings effect resembles a santa ana wind common in southern california in the autumn and winter in nearly every event observed the brookings effect occurs when there is a high pressure ridge off the pacific northwest coast or in the great basin depending on the time of year and often a cutoff low in southern to central california causing a northerly to easterly wind in the brookings area studies have shown that the north to south orientation of the chetco river mouth and the town of brookings plays a large role in the high temperatures recorded and the reason the effect is localized during most of the year a sea breeze sets up along the coastline with prevailing surface winds from the northwest the heart of brookings with its orientation is protected from this maritime flow and the warm dry down sloping winds that are funneled down the coastal range into the deep chetco river gorge can reach the coast uninfluenced by the effects of the pacific during the brookings effect there is a strong correlation between the observed temperature in brookings and the 850 millibar temperature the temperature at approximately 5 000 feet 1 500 m in medford oregon as is determined by the weather balloon sensing equipment launched twice a day medford located inland of brookings is located in a valley surrounded by the oregon coast range the siskiyou mountains and the cascade mountains the surface temperature in medford is often influenced by the mountains but the 850 millibar temperature well off the surface is about even with the mountain ridges in the area and therefore unaffected mesoscale easterly flow at this level will cause the same air mass to move westward toward brookings and studies show that high pressure induced atmospheric subsidence causes the air mass to flow down the slopes of the coastal range the chetco river gorge which is very deep in some places works as a funnel to bring the parcel to the coast often in the winter temperatures in medford may peak near 40 ° f 4 ° c while temperatures in brookings will reach the upper 70 s 25 ° c due to the effect causing brookings to live up to its banana belt reputation
brown s syndrome is a rare form of strabismus characterized by limited elevation of the affected eye the disorder may be congenital existing at or before birth or acquired brown syndrome is caused by a malfunction of the superior oblique muscle causing the eye to have difficulty moving up particularly during adduction when eye turns towards the nose harold w brown first described the disorder in 1950 and initially named it the superior oblique tendon sheath syndrome
brown séquard syndrome also known as brown séquard s hemiplegia brown séquard s paralysis hemiparaplegic syndrome hemiplegia et hemiparaplegia spinalis or spinal hemiparaplegia is caused by damage to one half of the spinal cord resulting in paralysis and loss of proprioception on the same or ipsilateral side as the injury or lesion and loss of pain and temperature sensation on the opposite or contralateral side as the lesion it is named after physiologist charles édouard brown séquard who first described the condition in 1850
the brown willy effect is a meteorological phenomenon that sometimes occurs across the south west peninsula of britain it leads to heavy showers developing over the high ground of bodmin moor in cornwall england which then often travel a considerable distance downwind of their place of origin it is named after the hill brown willy the highest point on the moor and in cornwall as a whole it is thought that the boscastle flood of 2004 was caused by a particularly extreme example of the effect
brown atrophy of the heart is atrophy of the heart muscle or myocardium commonly found in the elderly it is described as brown because fibers become pigmented by intracellular lipofuscin deposits mostly around the cell nucleus a type of lipochrome granule it has no known effect on function and is described as being expected or normal in aging other types of brown atrophy include brown atrophy of neuronia and brown atrophy of the liver
brown clustering is a hard hierarchical agglomerative clustering problem based on distributional information it is typically applied to text grouping words into clusters that are assumed to be semantically related by virtue of their having been embedded in similar contexts
brown induration is fibrosis and hemosiderin pigmentation of the lungs due to long standing pulmonary congestion chronic passive congestion
the brown ocean effect is an observed weather phenomenon where tropical cyclones which are commonly expected to lose energy when they make landfall instead maintain strength or intensify over land surfaces while these systems are highly common in the united states and china the national oceanic and atmospheric administration noaa names australia the most conducive environment after 30 years of research in australia such storm systems are called agukabams one source of the brown ocean effect has been identified as the large amount of latent heat that can be released from extremely wet soils a 2013 nasa study found that from 1979 2008 45 of 227 tropical storms either gained or maintained strength after making landfall the press release stated the land essentially mimics the moisture rich environment of the ocean where the storm originated originally countless research devoted to extratropical cyclones storms that first derive energy from the warm ocean waters and later from the conjecture of various air masses explained the intensification of storms after landfall however as research into these storms persists anderson and shepherd the two leading scientists behind the nasa study discovered that some of these storms were not transitioning from warm core to cold core but were actually maintaining their warm core dynamics while ultimately outputting a greater measure of rainfall in order for the brown ocean effect to take place three land conditions must be met first the lower level of the atmosphere mimics a tropical atmosphere with minimal variation in temperature second soils in the vicinity of the storms need to contain ample moisture finally evaporation of the soil moisture releases latent heat which the team found must measure at least 70 watts averaged per square meter storm systems impacted by the brown ocean effect gave rise to a new sub category of tropical storm type called tropical cyclone maintenance and intensification event or tcmi another study concluded that latent surface heat flux from land surfaces actually have the potential to be larger than from the ocean albeit for brief periods only anderson and shepherd are also examining the effects of climate change on tcmis looking into the potential intensification of these storms due to increase or decrease in the degree of wetness and dryness in areas susceptible to these systems
brown patch is a turfgrass disease that is caused by the rhizoctonia species fungus this turfgrass disease is most common brown patch can be found in all of the cool season turfgrasses found in the united states brown patch is most devastating to bentgrass agrostis sp ryegrass lolium sp annual bluegrass poa annua and tall fescue festuca arundinacea brown patch is also found in kentucky bluegrass poa pratensis and fine fescue festuca sp but this is rare or does minimal damage brown patch is known as a foliar disease so it does not have any effect on the crown or roots of the turf plant
the brown tumor is a bone lesion that arises in settings of excess osteoclast activity such as hyperparathyroidism it is not a true neoplasm as the term tumor suggests however it may mimic a true neoplasm brown tumours are radiolucent on x ray
brownfield status is a condition within certain legal exclusions and additions of real property the expansion redevelopment or reuse of which may be complicated by the presence or potential presence of a hazardous substance pollutant or contaminant which may include petroleum hydrocarbon releases brownfield status generally means there are use or development restrictions on the site in town planning brownfield land is an area of land previously used or built upon as opposed to greenfield land which has never been built upon brownfield status is a legal designation which places restrictions conditions or incentives on redevelopment
in aviation a brownout or brown out is an in flight visibility restriction due to dust or sand in the air in a brownout the pilot cannot see nearby objects which provide the outside visual references necessary to control the aircraft near the ground this can cause spatial disorientation and loss of situational awareness leading to an accident pilots have compared landing during brownouts to parallel parking an automobile with one s eyes closed the brownout phenomenon causes accidents during helicopter landing and take off operations in arid desert terrain intense blinding dust clouds stirred up by the helicopter rotor downwash during near ground flight causes significant flight safety risks from aircraft and ground obstacle collisions and dynamic rollover due to sloped and uneven terrain brownouts have claimed more helicopters in recent military operations than all other threats combined there are several factors which affect the probability and severity of brownout rotor disk loading rotor configuration soil composition wind approach speed and angle countermeasures to prevent brownout related accidents include site preparation pilot technique synthetic vision systems also known as see and remember upgraded horizontal situation indicator with improved symbology aerodynamics such as the winged rotor on the agustawestland eh 101 non visual displays of position and orientation data derived from suitable sensors such as tactile situational awareness systems tsas providing information to the pilot through the sense of touch using tactors
brown vialetto van laere syndrome bvvl sometimes known as brown s syndrome is a rare degenerative disorder often initially characterized by progressive sensorineural deafness the syndrome most often affects children adolescents and young adults as knowledge of bvvl grows some adult patients have now been diagnosed there is no known cure however with prompt treatment the prognosis may be positive with some patients stabilizing and even minor improvements noted in certain cases
brucellosis is a highly contagious zoonosis caused by ingestion of unpasteurized milk or undercooked meat from infected animals or close contact with their secretions brucella species are small gram negative nonmotile nonspore forming rod shaped coccobacilli bacteria they function as facultative intracellular parasites causing chronic disease which usually persists for life four species infect humans b abortus b canis b melitensis and b suis b abortus is less virulent than b melitensis and is primarily a disease of cattle b canis affects dogs b melitensis is the most virulent and invasive species it usually infects goats and occasionally sheep b suis is of intermediate virulence and chiefly infects pigs symptoms include profuse sweating and joint and muscle pain brucellosis has been recognized in animals and humans since the 20 th century
brugada syndrome brs is a genetic disease that is characterised by abnormal electrocardiogram ecg findings and an increased risk of sudden cardiac death it is named for the spanish cardiologists pedro brugada josep brugada and ramon brugada it is the major cause of sudden unexplained death syndrome suds also known as sudden adult death syndrome sads and is the most common cause of sudden death in young men without known underlying cardiac disease in thailand and laos although the ecg findings of brugada syndrome were first reported among survivors of cardiac arrest in 1989 it was only in 1992 that the brugada brothers recognized it as a distinct clinical entity causing sudden death by causing ventricular fibrillation a potentially lethal arrhythmia in the heart
a bruise or contusion is a type of hematoma of tissue in which capillaries and sometimes venules are damaged by trauma allowing blood to seep hemorrhage or extravasate into the surrounding interstitial tissues bruises which do not blanch under pressure can involve capillaries at the level of skin subcutaneous tissue muscle or bone bruises are not to be confused with other similar looking lesions primarily distinguished by their diameter or causation these lesions include petechia 3 mm result from numerous and diverse etiologies such as adverse reactions from medications such as warfarin straining asphyxiation platelet disorders and diseases such as cytomegalovirus purpura 3 mm to 1 cm classified as palpable purpura or non palpable purpura and indicates various pathologic conditions such as thrombocytopenia and ecchymosis 1 cm caused blood dissecting through tissue planes and settled in an area remote from the site of trauma or pathology such as periorbital ecchymosis i e raccoon eyes arising from a basilar skull fracture or from a neuroblastoma as a type of hematoma a bruise is always caused by internal bleeding into the interstitial tissues which does not break through the skin usually initiated by blunt trauma which causes damage through physical compression and deceleration forces trauma sufficient to cause bruising can occur from a wide variety of situations including accidents falls and surgeries disease states such as insufficient or malfunctioning platelets other coagulation deficiencies or vascular disorders such as venous blockage associated with severe allergies can lead to the formation of purpura which is not to be confused with trauma related bruising contusion if the trauma is sufficient to break the skin and allow blood to escape the interstitial tissues the injury is not a bruise but instead a different variety of hemorrhage called bleeding however such injuries may be accompanied by bruising elsewhere bruises often induce pain but small bruises are not normally dangerous alone sometimes bruises can be serious leading to other more life threatening forms of hematoma such as when associated with serious injuries including fractures and more severe internal bleeding the likelihood and severity of bruising depends on many factors including type and healthiness of affected tissues minor bruises may be easily recognized in people with light skin color by characteristic blue or purple appearance idiomatically described as black and blue in the days following the injury
bruit english ˈbruːi from french noise or vascular murmur is the abnormal sound generated by turbulent flow of blood in an artery due to either an area of partial obstruction or a localized high rate of blood flow through an unobstructed artery the bruit may be heard auscultated by pressing a stethoscope to the skin over the turbulent flow and listening most bruits occur only in systole so the bruit is intermittent and its frequency dependent on the heart rate anything increasing the blood flow velocity such as fever anemia or hyperthyroidism can increase the amplitude of the bruit
brunner syndrome is a rare genetic disorder associated with a mutation in the maoa gene it is characterized by lower than average iq typically about 85 problematic impulsive behavior such as arson hypersexuality and violence sleep disorders and mood swings it was identified in fourteen males from one family in 1993 it has since been discovered in two additional families
bruno otto fleischer 2 may 1874 – 26 march 1965 was a german doctor kayser fleischer rings and fleischer rings are named for him
bruns apraxia or frontal ataxia is a gait apraxia found in patients with bilateral frontal lobe disorders it is characterised by an inability to initiate the process of walking despite the power and coordination of the legs being normal when tested in the seated or lying position the gait is broad based with short steps with a tendency to fall backwards it was originally described in patients with frontal lobe tumours but is now more commonly seen in patients with cerebrovascular disease it is named after ludwig bruns
bruxism is excessive teeth grinding or jaw clenching it is an oral parafunctional activity i e it is unrelated to normal function such as eating or talking bruxism is a common problem reports of prevalence range from 8 – 31 in the general population several symptoms are commonly associated with bruxism including hypersensitive teeth aching jaw muscles headaches tooth wear damage to dental restorations e g crowns and fillings and damage to teeth however it may cause minimal symptoms and therefore people may not be aware of the condition there are two main types of bruxism that which occurs during sleep sleep bruxism and that which occurs during wakefulness awake bruxism dental damage may be similar in both types but the symptoms of sleep bruxism tend to be worse on waking and improve during the course of the day and the symptoms of awake bruxism may not be present at all on waking and then worsen over the day the causes of bruxism are not completely understood but probably involve multiple factors awake bruxism is thought to have different causes from sleep bruxism and is more common in females whereas males and females are affected in equal proportions by sleep bruxism several treatments are in use although there is little evidence of robust efficacy for any particular treatment
bubble hair deformity is an abnormality of the hair shaft it is characterized by rows of bubbles seen microscopically within localized areas of brittle hair
bubonic plague is one of three types of bacterial infection caused by yersinia pestis three to seven days after exposure to the bacteria flu like symptoms develop this includes fever headaches and vomiting swollen and painful lymph nodes occur in the area closest to where the bacteria entered the skin occasionally the swollen lymph nodes may break open the three types of plague are the result of the route of infection bubonic plague septicemic plague and pneumonic plague bubonic plague is mainly spread by infected fleas from small animals it may also result from exposure to the body fluids from a dead plague infected animal in the bubonic form of plague the bacteria enter through the skin through a flea bite and travel via the lymphatic vessels to a lymph node causing it to swell diagnosis is by finding the bacteria in the blood sputum or fluid from lymph nodes prevention is through public health measures such as not handling dead animals in areas where plague is common vaccines have not been found to be very useful for plague prevention several antibiotics are effective for treatment including streptomycin gentamicin and doxycycline without treatment it results in the death of 30 to 90 of those infected death if it occurs is typically within ten days with treatment the risk of death is around 10 globally in 2013 there were about 750 documented cases which resulted in 126 deaths the disease is most common in africa plague is believed to be the cause of the black death that swept through asia europe and africa in the 14 th century and killed an estimated 50 million people this was about 25 to 60 of the european population because the plague killed so many of the working population wages rose due to the demand for labor some historians see this as a turning point in european economic development the term bubonic plague is derived from the greek word βουβών meaning groin the term buboes is also used to refer to the swollen lymph nodes
buccal bifurcation cyst is an inflammatory odontogenic cyst of the paradental cysts family that typically appears in the buccal bifurcation region of the mandibular first molars in the second half of the first decade of life infected cysts may be associated with pain
a buccal exostosis also termed alveolar exostosis is an exostosis bone prominence on the buccal surface cheek side of the alveolar ridge of the maxilla or mandible some consider them a variation of normal anatomy rather than a disease
the bucherer carbazole synthesis is a chemical reaction used to synthesize carbazoles from naphthols and aryl hydrazines using sodium bisulfite the reaction is named after hans theodor bucherer the bucherer carbazole synthesis
the bucherer – bergs reaction is the chemical reaction of carbonyl compounds aldehydes or ketones or cyanohydrins with ammonium carbonate and potassium cyanide to give hydantoins the reaction is named after hans theodor bucherer overall reaction the bucherer bergs reaction
in egyptian mythology buchis also spelt bakh and bakha was the manifestation of the deification of ka power life force of the war god montu worshipped in the region of hermonthis a wild bull was chosen and said to be the buchis incarnation of montu in which role it was worshipped as such over time the criteria for choosing the bull became more rigid fixing themselves on what had been simply the general appearance of bulls in the region being a white body and black face when these bulls or their mothers died they were mummified and placed in a special cemetery known as the bucheum the mothers of these bulls were considered aspects of hathor the mother of these deities eventually the bakha was identified as a form of the apis and consequently became considered an incarnation of osiris the last burial of a buchis bull in the bucheum at hermonthis occurred in 340 a d the worship of the bull in this form lasted until about 362 ad when it was destroyed by rising christianity in the roman empire
in mathematics buchsbaum rings are noetherian local rings such that every system of parameters is a weak sequence a sequence of the maximal ideal is called a weak sequence if for all they were introduced by jürgen stückrad and wolfgang vogel and are named after david buchsbaum every cohen – macaulay local ring is a buchsbaum ring
the buchwald – hartwig amination is a chemical reaction used in organic chemistry for the synthesis of carbon – nitrogen bonds via the palladium catalyzed cross coupling of amines with aryl halides although pd catalyzed c n couplings were reported as early as 1983 credit for its development is typically assigned to stephen l buchwald and john f hartwig whose publications between 1994 and the late 2000 s established the scope of the transformation the reaction s synthetic utility stems primarily from the shortcomings of typical methods nucleophilic substitution reductive amination etc for the synthesis of aromatic c – n bonds with most methods suffering from limited substrate scope and functional group tolerance the development of the buchwald – hartwig reaction allowed for the facile synthesis of aryl amines replacing to an extent harsher methods the goldberg reaction nucleophilic aromatic substitution etc while significantly expanding the repertoire of possible c – n bond formation over the course of its development several generations of catalyst systems have been developed with each system allowing greater scope in terms of coupling partners and milder conditions allowing virtually any amine to be coupled with a wide variety of aryl coupling partners because of the ubiquity of aryl c n bonds in pharmaceuticals and natural products the reaction has gained wide use in synthetic organic chemistry finding application in many total syntheses and the industrial preparation of numerous pharmaceuticals several reviews have been published
in buddhism buddhahood sanskrit बुद्धत्व buddhatva pali बुद्धत्त buddhatta or बुद्धभाव buddhabhāva is the condition or rank of a buddha ˈbuːdə or ˈbʊdə sanskrit pronunciation ˈbud̪d̪ʱə pali sanskrit for awakened one the goal of mahayana s bodhisattva path is samyaksambuddhahood so that one may benefit all sentient beings by teaching them the path of cessation of dukkha this contrasts with the goal of hinayana path where the goal is arhatship
budd – chiari syndrome is a condition caused by occlusion of the hepatic veins that drain the liver it presents with the classical triad of abdominal pain ascites and liver enlargement the formation of a blood clot within the hepatic veins can lead to budd – chiari syndrome it occurs in 1 out of a million individuals the syndrome can be fulminant acute chronic or asymptomatic
the buffalo riot of 1862 was a civil disturbance on the afternoon of august 12 1862 by irish and german stevedores against local dock bosses the rioters demanded increased pay and prevented others from working at the old rates they initially overpowered police seriously injuring the chief of police and other officers but were forced to surrender after police opened fire wounding two although the mayor had called for the new york state militia police arrested the ringleaders before the militia was needed
bufferbloat is high latency in packet switched networks caused by excess buffering of packets bufferbloat can also cause packet delay variation also known as jitter as well as reduce the overall network throughput when a router or switch is configured to use excessively large buffers even very high speed networks can become practically unusable for many interactive applications like voice over ip voip online gaming and even ordinary web surfing some communications equipment manufacturers placed overly large buffers in some of their network products in such equipment bufferbloat occurs when a network link becomes congested causing packets to become queued in buffers for too long in a first in first out queuing system overly large buffers result in longer queues and higher latency but do not improve network throughput the bufferbloat phenomenon was initially described as far back as in 1985 it gained more widespread attention starting in 2009
in strategy computer games of both the turn based and real time varieties a build order is a linear pattern of production research and resource management aimed at achieving a specific and specialized goal they are analogous to chess openings in that a player will have a specific order of play in mind however the amount the build order the strategy around which the build order is built or even which build order is then used varies on the skill ability and other factors such as how aggressive or defensive each player is often the name of a build order usually reflects two key aspects therein the desired goal of the entire build order the key management decisions involved in the build order evidence of this can be found in the following examples six pool rush starcraft – six pool being the management decision build a spawning pool immediately after reaching supply level 6 rush implying production of zerglings quickly 4 warpgates push starcraft ii wings of liberty – opening in which the goal is to have a warpgate and 4 gateways and then push attack the enemy rule of ten warhammer 40 000 dawn of war – ten being the desired production goal of infantry units oranos 4 30 age of mythology the titans – 4 30 being the desired time to reach tech level 2 4 es company of heroes 4 es standing for 4 engineers and a sniper a unique american opening fast armored car company of heroes – the objective being to get an armored car before the opponent has reached the same tech level riflestall company of heroes – the objective being to use the power and flexibility of riflemen squads to hold off the opponent before pulling out higher tech units piospam company of heroes – the objective being to produce large numbers of pioneers and nothing else until higher tier expansion first generic start by creating a new economic base prioritizing your economy output rather than defensive or offensive units this is usually easily countered if your opponent if going for an early aggression build order strategy computer games typically offer a player many choices in which structures to build units to train and which technologies to research each technology that a player researches will open up more options but may or may not depending on the computer game the player is playing close off the paths to other options a tech tree is the representation of all possible paths of research a player can take analysis of the tech tree leads to specific paths that a player can take to optimally advance specific strategic or tactical goals these optimized paths are build orders for example a player who plans to launch an attack by air may only build the structures necessary to construct air units and may research only the technologies which enhance the capabilities of air units the order in which to build those structures and research those technologies is known as a build order the same player could instead choose a slightly different build order that goes for air units but also creates a small ground defense army – this would be a more defensive less risky choice at the expense of having maximum airspace power as you can see in the list above build orders are usually used to determine how a player will start the game which is why they are often miscalled openings there are many reasons for this a flawed game start could mean that you lose the game early on so it is important to have resilient openings how you start a match most often than not narrows the middle and late game options so the very first few choices alone dictate your future options middle and late game choices require you to study the current situation so not only are they harder to plan ahead but then one also has more time to think while on the very beginning it is more advantageous to have a fixed plan and execute it as fast and precisely as possible build orders can also plan ahead for late game scenarios but that is less common build orders often involve significant timing issues this applies to both turn based and real time strategy games in turn based games specific buildings and technologies will take a specific number of turns to complete a build order may involve waiting until specific turns to begin building the next building or researching the next technology in real time strategy games timing may be even more crucial to execute an optimal rush a player will not only have to know exactly what to build or research but also when to do so if the build order is altered in any way the units or structures may not be produced as quickly the delay may mean the difference between a game win and a game loss experienced players of strategy games will memorize build orders as it gives them a significant advantage over players who are not familiar with build orders this is particularly important in games where there is a resource cap such as food in the warcraft series or supply in the starcraft series as a player must know how much remaining supply they have to work with for a given build order since the game mechanics will not permit players to build past this limit without additional resource structures the build order and the timing of new construction must be implemented in a very precise manner build orders involve all forms of resource management including unit production and control the loss of a unit or the overproduction of another may delay or change the course of a build order complex build orders that involve a combination of key units may fail completely due to improper unit control despite correct development of buildings and technology research in professional and competitive tournaments it is implicit that before a match each player will have studied his opponent s recent public games in order to prepare an appropriate build order to defeat his style since both players understand that each side will be doing this it can create interesting situations – for example a defense oriented player could pretend to be using his traditional strategy to fool his opponent while instead creating an offensive force in a hard to spot position this makes competitive strategy gaming as much a guessing of what your opponent is trying to do as it is on focusing on your own strategy in order to win this sort of play is often called mind games by narrators and commentators and it often happens that a bad read on an opponent s intentions is enough to lose a match
in single point cutting of metals a built up edge bue is an accumulation of material against the rake face that seizes to the tool tip separating it from the chip
bulbar palsy refers to impairment of function of the cranial nerves ix x xi and xii which occurs due to a lower motor neuron lesion either at nuclear or fascicular level in the medulla oblongata or from lesions of the lower cranial nerves outside the brainstem in contrast pseudobulbar palsy describes impairment of function of cranial nerves ix xii due to upper motor neuron lesions of the corticobulbar tracts in the mid pons for clinically evident dysfunction to occur such lesions must be bilateral as these cranial nerve nuclei receive bilateral innervation bulbar palsy is an assortment of signs and symptoms not the name of a precise disease
bulbar urethral necrosis is a problem that can occur after a pelvic fracture associated urethral distraction defect pfudd
bulimia nervosa also known as simply bulimia is an eating disorder characterized by binge eating followed by purging binge eating refers to eating a large amount of food in a short amount of time purging refers to the attempts to get rid of the food consumed this may be done by vomiting or taking laxatives other efforts to lose weight may include the use of diuretics stimulants water fasting or excessive exercise most people with bulimia are at a normal weight the forcing of vomiting may result in thickened skin on the knuckles and breakdown of the teeth bulimia is frequently associated with other mental disorders such as depression anxiety and problems with drugs or alcohol there is also a higher risk of suicide and self harm bulimia is more common among those who have a close relative with the condition the percentage risk that is estimated to be due to genetics is between 30 and 80 other risk factors for the disease include psychological stress cultural pressure to attain a certain body type poor self esteem and obesity living in a culture that promotes dieting and having parents that worry about weight are also risks diagnosis is based on a person s medical history however this is difficult as people are usually secretive about their binge eating and purging habits furthermore the diagnosis of anorexia nervosa takes precedence over that of bulimia other similar disorders include binge eating disorder kleine levin syndrome and borderline personality disorder cognitive behavioral therapy is the primary treatment for bulimia antidepressants of the selective serotonin reuptake inhibitors ssri or tricyclic antidepressant class may have a modest benefit while outcomes with bulimia are typically better than in those of anorexia the risk of death among those affected is higher than that of the general population at 10 years after receiving treatment about 50 of people are fully recovered globally bulimia was estimated to affect 6 5 million people in 2013 about 1 of young women have bulimia at a given point in time and about 2 to 3 of women have the condition at some point in their lives the condition is less common in the developing world bulimia is about nine times more likely to occur in women than men among women rates are highest in young adults bulimia was named and first described by the british psychiatrist gerald russell in 1979
bulk foods are food items offered in large quantities which can be purchased in large bulk lots or transferred from a bulk container into a smaller container for purchase bulk foods may be priced less compared to packaged foods because they re typically packaged in large generic bulk containers and packaging for grocery outlets which utilizes lesser natural resources additionally less packaging is congruent with the environmental conservation of natural resources and sustainability one study found a 96 reduction in packaging used for bulk foods compared to packaged foods
bullet time also known as adrenaline time focus time frozen time the big freeze dead time flow motion slowing your roll dead eye or time slice is a visual effect or visual impression of detaching the time and space of a camera or viewer from that of its visible subject it is a depth enhanced simulation of variable speed action and performance found in films broadcast advertisements and realtime graphics within video games and other special media it is characterized both by its extreme transformation of time slow enough to show normally imperceptible and unfilmable events such as flying bullets and space by way of the ability of the camera angle — the audience s point of view — to move around the scene at a normal speed while events are slowed this is almost impossible with conventional slow motion as the physical camera would have to move impossibly fast the concept implies that only a virtual camera often illustrated within the confines of a computer generated environment such as a virtual world or virtual reality would be capable of filming bullet time types of moments technical and historical variations of this effect have been referred to as time slicing view morphing temps mort french dead time and virtual cinematography the term bullet time is a registered trademark of warner bros formally established in march 2005 in connection with the video game the matrix online the term had first been used within the original script of the 1999 film the matrix and later in reference to the slow motion effects in the 2001 video game max payne in the years since the introduction of the term during the matrix films it has become a commonly applied expression in popular culture
bullous drug reaction also known as a bullous drug eruption generalized bullous fixed drug eruption and multilocular bullous fixed drug eruption most commonly refers to a drug reaction in the erythema multiforme group these are uncommon reactions to medications with an incidence of 0 4 to 1 2 per million person years for toxic epidermal necrolysis and 1 2 to 6 0 per million person years for stevens – johnson syndrome the primary skin lesions are large erythemas faintly discernible even after confluence most often irregularly distributed and of a characteristic purplish livid color at times with flaccid blisters
bullous impetigo is a cutaneous condition that characteristically occurs in the newborn and is caused by a bacterial infection presenting with bullae it can be caused by exfoliative toxin a the phyogenic superficial infection can be divided into two other subdivisions impetigo and non bullous impetigo bullous impetigo is caused by staphylococcus aureus which produces exfoliative toxins whereas non bullous impetigo is caused by either staphylococcus aureus or streptococcus pyogenes thirty percent of all impetigo cases are related to bullous impetigo bullous impetigo in newborns children or adults who are immunocompromised and or are experiencing renal failure can develop into a more severe and generalized form called staphylococcal scalded skin syndrome ssss the mortality rate is less than 3 for infected children but up to 60 in adults
bullous keratopathy is a pathological condition in which small vesicles or bullae are formed in the cornea due to endothelial dysfunction in a healthy cornea endothelial cells keeps the tissue from excess fluid absorption pumping it back into the aqueous humor when affected by some reason such as fuchs dystrophy or a trauma during cataract removal endothelial cells suffer mortality or damage the corneal endothelial cells normally do not undergo mitotic cell division and cell loss results in permanent loss of function when endothelial cell counts drop too low the pump starts failing to function and fluid moves anterior into the stroma and epithelium the excess fluid precipitates swelling of the cornea as fluid accumulates between the basal epithelium cells blister like formations form bullae and they undergo painful ruptures releasing their fluid content to the surface these characteristic malformations disrupt vision and create pain sensations treatment can include hyperosmotic eye drops to reduce swelling 5 sodium chloride bandage contact lenses to reduce discomfort glaucoma medications to reduce the flow of fluid into the cornea and surgical procedures to replace the damaged tissue
bullous lymphedema is a skin condition that usually occurs with poorly controlled edema related to heart failure and fluid overload and compression results in healing
bullous pemphigoid is an acute or chronic autoimmune skin disease involving the formation of blisters more appropriately known as bullae at the space between the skin layers epidermis and dermis it is classified as a type ii hypersensitivity reaction with the formation of anti hemidesmosome antibodies
bullous small vessel vasculitis also known as bullous variant of small vessel vasculitis is a cutaneous condition in which patients with small vessel vasculitis will develop superimposed vesicles and bullae especially on the distal extremities
the bullwhip effect is a distribution channel phenomenon in which forecasts yield supply chain inefficiencies it refers to increasing swings in inventory in response to shifts in customer demand as one moves further up the supply chain the concept first appeared in jay forrester s industrial dynamics 1961 and thus it is also known as the forrester effect the bullwhip effect was named for the way the amplitude of a whip increases down its length the further from the originating signal the greater the distortion of the wave pattern in a similar manner forecast accuracy decreases as one moves upstream along the supply chain for example many consumer goods have fairly consistent consumption at retail but this signal becomes more chaotic and unpredictable as you move away from consumer purchasing behavior in the 1990 s hau lee a professor of engineering and management science at stanford university helped incorporate the concept into supply chain vernacular using a story about volvo suffering a glut in green cars sales and marketing developed a program to move the excess inventory while successful in generating the desired market pull manufacturing didn t know about the promotional plans instead they read the increase in sales as an indication of growing demand for green cars and ramped up production research indicates a fluctuation in point of sale demand of five percent will be interpreted by supply chain participants as a change in demand of up to forty percent much like cracking a whip a small flick of the wrist a shift in point of sale demand can cause a large motion at the end of the whip manufacturer s response
bumblefoot ulcerative pododermatitis is a bacterial infection and inflammatory reaction on the feet of birds and rodents this infection is much more likely to occur in captive animals than in those in the wild it is caused by staphylococcus bacteria
a bumper fracture is a fracture of the lateral tibial plateau caused by a forced valgus applied to the knee this causes the lateral part of the distal femur and the lateral tibial plateau to come into contact compressing the tibial plateau and causing the tibia to fracture the name of the injury is because it was described as being caused by the impact of a car bumper on the lateral side of the knee while the foot is planted on the ground although this mechanism is only seen in about 25 of tibial plateau fractures fracture of the neck of the fibula may also be found and associated injury to the medial collateral ligament or cruciate ligaments occurs in about 10 of cases
bumping is a phenomenon in chemistry where homogenous liquids boiled in a test tube or other container will superheat and upon nucleation rapid boiling will expel the liquid from the container in extreme cases the container may be broken
a bundle branch block is a defect of the bundle branches or fascicles in the electrical conduction system of the heart
a bunion is a deformity of the joint connecting the big toe to the foot it is characterized by medial deviation of the first metatarsal bone and lateral deviation of the hallux big toe often erroneously described as an enlargement of bone or tissue around the joint at the bottom of the big toe known as the metatarsophalangeal joint there is disagreement among medical professionals about the cause of bunions some see them as primarily caused by the long term use of shoes particularly tight fitting shoes with pointed toes others believe that the problem stems from genetic factors that are exacerbated by shoe use bunions occur when pressure is applied to the side of the big toe hallux forcing it inwards towards and sometimes under or over the other toes angulation as pressure is applied the tissues surrounding the joint may become swollen and tender in a survey of people from cultures that do not wear shoes no cases of bunions were found lending credence to the hypothesis that bunions are caused by ill fitting shoes the bump itself is partly due to the swollen bursal sac or an osseous bony anomaly on the metatarsophalangeal joint the larger part of the bump is a normal part of the head of the first metatarsal bone that has tilted sideways to stick out at its distal far end
the bunsen reaction is a chemical reaction that describes water sulfur dioxide and iodine reacting to form sulfuric acid and hydrogen iodide 2 h 2 o so 2 i 2 → h 2 so 4 2 hi this reaction is the first step in the sulfur iodine cycle to produce hydrogen the products separate into two aqueous layers with the sulfuric acid floating on top and a mixture of hydrogen iodide and unreacted iodine on the bottom while the two layers are generally considered immiscible small amounts of sulfuric acid may still remain in the hydrogen iodide layer and vice versa this can lead to unwanted side reactions one of which precipitates out sulfur a potential obstruction to the reaction vessel the reaction is named after robert bunsen who discovered it in 1853 a similar reaction is the basis for karl fischer titration note that at sufficiently high temperatures concentrated h 2 so 4 may react with hi giving i 2 so 2 and h 2 o which reverses the reaction many chemical processes are reversible reactions such as ammonia production from n 2 and h 2 and removing the desired product will shift equilibrium to the right of the equation favoring reaction products as per the le chatelier principle
bunter beds are sandstone deposits containing rounded pebbles they can be found in warwickshire cheshire staffordshire nottinghamshire yorkshire devon and dorset in england they are thought to be alluvial deposits and judging from the rounding of the mainly quartzite pebbles to have resulted from prolonged transportation in a large and turbulent river resulting in powerful abrasion the deposits in the english midlands are thought to have been transported in this way northwards from brittany france this supposed river has been called the budleighensis after the devon village of budleigh salterton a site where such deposits were discovered the depositions took place in the lower triassic period some newer conglomerates e g near ryton in warwickshire are thought to have arisen during the ice age by reworking and southward transportation of older deposits by ice flows the pebbles also called cobbles which can be used as gravel as ballast or as cobblestones are mainly milky white quartzite but can vary in colour and composition including some that are hard reddish coloured sandstone the sandstone in which these pebbles are deposited can be used for building or as an aggregate for cement or concrete the name bunter derives from the german term buntsandstein bunt meaning variegated or colourful referring to the colour of the sandstone deposit which varies from reddish to greenish this sandstone is widespread across central europe notably in the black forest and odenwald region of germany as well as the vosges mountains in northeastern france the sandstone can be hard enough for building yet easy enough to work resulting in bridges castles cathedrals and churches constructed of reddish sandstone throughout the relevant areas of europe e g germany luxembourg switzerland alsace in france denmark poland the land under which these beds lie is generally very well drained creating heathlike conditions because of the drainage the soil tends to be of low fertility a notable area in britain that has these characteristics is cannock chase a designated area of outstanding natural beauty aonb the long shingle tombolo of chesil beach in dorset and the raised beach of portland dorset are partly composed of bunter pebbles as yet no fully satisfactory and universally accepted geological explanation has been formulated to explain their precise origin and mode of transport as each proposed theory has its difficulties
buphthalmos plural buphthalmoses is enlargement of the eyeball and is most commonly seen in infants and young children it is sometimes referred to as buphthalmia plural buphthalmias it usually appears in the newborn period or the first 3 months of life and in most cases indicates the presence of congenital infantile glaucoma which is a disorder in which elevated pressures within the eye lead to structural eye damage and vision loss
bur oak blight bob is a fungal disease that is relatively new to the plant pathogen landscape bob started to appear in midwestern states in the 1990 s the first few diagnoses pointed to a common fungus tubakia dryina as the culprit however upon further research bob was said to be caused by a new unnamed species of tubakia later named ‘ ’ tubakia iowensis t c harr d mcnew sp nov ‘ ’ bob has severe symptoms and is a serious new problem amidst the plant pathology world
buried penis also known as hidden penis is a congenital or acquired condition in which the penis is partially or completely hidden below the surface of the skin it can lead to obstruction of urinary stream poor hygiene soft tissue infection phimosis and inhibition of normal sexual function congenital causes are often due to maldevelopment of penile shaft skin whereas acquired conditions include morbid obesity overlaying abdominal fat or penile injury adults with a buried penis will either live with their condition or undergo weight loss programs however weight loss programs are slow and often do not unbury the penis furthermore poor hygiene from pooling of urine can lead to soft tissue infection patients will eventually need definitive reconstructive surgery and more urgent surgery if infection is present surgeons who manage this condition are either reconstructive urologic surgeons or plastic surgeons
in mathematics the burkhardt quartic is a quartic threefold in 4 dimensional projective space studied by burkhardt with the maximum possible number of 45 nodes the equations defining the burkhardt quartic become simpler if it is embedded in p 5 rather than p 4 in this case it can be defined by the equations σ 1 σ 4 0 where σi is the ith elementary symmetric function of the coordinates x 0 x 1 x 2 x 3 x 4 x 5 of p 5 the automorphism group of the burkhardt quartic is the burkhardt group u 4 2 psp 4 3 a simple group of order 25920 which is isomorphic to a subgroup of index 2 in the weyl group of e 6
burkitt lymphoma also known as burkitt s tumor burkitt s lymphoma or malignant lymphoma burkitt s type is a cancer of the lymphatic system particularly b lymphocytes found in the germinal center it is named after denis parsons burkitt a surgeon who first described the disease in 1958 while working in equatorial africa
a burl american english or bur or burr uk english is a tree growth in which the grain has grown in a deformed manner it is commonly found in the form of a rounded outgrowth on a tree trunk or branch that is filled with small knots from dormant buds
a burn is a type of injury to skin or other tissues caused by heat cold electricity chemicals friction or radiation most burns are due to heat from hot liquids solids or fire females in many areas of the world have a higher risk related to the more frequent use of open cooking fires or unsafe cook stoves alcoholism and smoking are other risk factors burns can also occur as a result of self harm or violence between people burns that affect only the superficial skin layers are known as superficial or first degree burns they appear red without blisters and pain typically lasts around three days when the injury extends into some of the underlying skin layer it is a partial thickness or second degree burn blisters are frequently present and they are often very painful healing can require up to eight weeks and scarring may occur in a full thickness or third degree burn the injury extends to all layers of the skin often there is no pain and the burn area is stiff healing typically does not occur on its own a fourth degree burn additionally involves injury to deeper tissues such as muscle tendons or bone the burn is often black and frequently leads to loss of the burned part burns are generally preventable treatment depends on the severity of the burn superficial burns may be managed with little more than simple pain medication while major burns may require prolonged treatment in specialized burn centers cooling with tap water may help pain and decrease damage however prolonged cooling may result in low body temperature partial thickness burns may require cleaning with soap and water followed by dressings it is not clear how to manage blisters but it is probably reasonable to leave them intact if small and drain them if large full thickness burns usually require surgical treatments such as skin grafting extensive burns often require large amounts of intravenous fluid due to capillary fluid leakage and tissue swelling the most common complications of burns involve infection tetanus toxoid should be given if not up to date in 2013 fire and heat resulted in 35 million injuries this resulted in about 2 9 million hospitalizations and 238 000 dying most deaths due to burns occur in the developing world particularly in southeast asia while large burns can be fatal treatments developed since 1960 have improved outcomes especially in children and young adults in the united states approximately 96 of those admitted to a burn center survive their injuries burns occur at similar frequencies in men and women the long term outcome is related to the size of burn and the age of the person affected
burn scar contracture refers to the tightening of the skin after a second or third degree burn when skin is burned the surrounding skin begins to pull together resulting in a contracture it needs to be treated as soon as possible because the scar can result in restriction of movement around the injured area
in the archaeology of neolithic europe the burned house horizon is the geographical extent of the phenomenon of intentionally burned settlements this was a widespread and long lasting tradition in what is now southeastern and eastern europe lasting from as early as 6 500 bce the beginning of the neolithic to as late as 2000 bce the end of the chalcolithic and the beginning of the bronze age a notable representative of this tradition is the cucuteni trypillian culture which was centered on the burned house horizon both geographically and temporally there is a consensus in the study of neolithic and eneolithic europe that the majority of burned houses were intentionally set alight although the reasons behind why house burning was practiced are still debated the evidence seems to support that it occurred in such a way as to indicate it was highly unlikely to have been as a result of accidental cause if these regularly occurring burnings in which the entire settlement is destroyed were deliberate then there has still been a debate about why this happened however in recent years the consensus has begun to gel around the domicide theory supported by tringham stevanovic and others cucuteni trypillian settlements were completely burned every 75 – 80 years leaving behind successive layers consisting mostly of large amounts of rubble from the collapsed wattle and daub walls this rubble was mostly ceramic material that had been created as the raw clay used in the daub of the walls became vitrified from the intense heat that would have turned it a bright orange color during the conflagration that destroyed the buildings much the same way that raw clay objects are turned into ceramic products during the firing process in a kiln moreover the sheer amount of fired clay rubble found within every house of a settlement indicates that a fire of enormous intensity would have raged through the entire community to have created the volume of material found
burning feet syndrome also known as grierson gopalan syndrome is a medical condition that causes severe burning and aching of the feet hyperesthesia and vasomotor changes of the feet that lead to excessive sweating it can even affect the eyes causing scotoma and amblyopia the condition occurs more frequently in women and usually manifests itself when a person is between twenty and forty years old
burning mouth syndrome bms is the complaint of a burning sensation in the mouth where no underlying dental or medical cause can be identified and no signs found in the mouth burning mouth syndrome may also comprise subjective xerostomia a dry mouth sensation where no cause can be found such as reduced salivary flow oral paraesthesia e g tingling and altered taste or smell dysgeusia and dysosmia a burning sensation in the mouth can be a symptom of another disease when local or systemic factors are found to be implicated and this is not considered to be burning mouth syndrome which is a syndrome of medically unexplained symptoms the international association for the study of pain defines burning mouth syndrome as a distinctive nosological entity characterized by unremitting oral burning or similar pain in the absence of detectable mucosal changes and burning pain in the tongue or other oral mucous membranes and the international headache society defines it as an intra oral burning sensation for which no medical or dental cause can be found
burnside butler syndrome also known as 15 q 11 2 bp 1 bp 2 microdeletion is a congenital disorder caused by microdeletion of dna sequences it is associated with a number of developmental and psychiatric disorders
burrknot is a tree disorder which is caused by formation of adventitious root primordia although previously classified as disease is now classified as a disorder as it is no longer believed to be pathogenic first looks like a smooth orange bulge growing from the stem or a branch later multiple adventitious roots form
bursitis is the inflammation of one or more bursae small sacs of synovial fluid in the body they are lined with a synovial membrane that secretes a lubricating synovial fluid there are more than 150 bursae in the human body the bursae rest at the points where internal functionaries such as muscles and tendons slide across bone healthy bursae create a smooth almost frictionless functional gliding surface making normal movement painless when bursitis occurs however movement relying on the inflamed bursa becomes difficult and painful moreover movement of tendons and muscles over the inflamed bursa aggravates its inflammation perpetuating the problem muscle can also be stiffened
a burst fracture is a type of traumatic spinal injury in which a vertebra breaks from a high energy axial load e g traffic collisions or falls from a great height or high speed and some kinds of seizures with sharps of vertebra penetrating surrounding tissues and sometimes the spinal canal the burst fracture is categorized by the severity of the deformity the severity of spinal canal compromise the degree of loss of vertebral body height and the degree of neurologic deficit burst fractures are considered more severe than compression fractures because long term neurological damage can follow the neurologic deficits can reach their full extent immediately or can progress for a prolonged time
a burst lobe is an intracranial hemorrhage affecting a brain lobe part of the cerebral hemispheres and characterized by an intracerebral hemorrhage in continuity with a subdural hemorrhage on a ct scan it is shown as an irregular area of increased density which is blood clot this is surrounded by a low density area of oedema
burst suppression is an electroencephalography eeg pattern that is characterized by periods of high voltage electrical activity alternating with periods of no activity in the brain the pattern is found in patients with inactivated brain states such as from general anesthesia coma or hypothermia this pattern can be physiological as during early development or pathological as in diseases such as ohtahara syndrome
the burstein – moss effect is the phenomenon of which the apparent band gap of a semiconductor is increased as the absorption edge is pushed to higher energies as a result of all states close to the conduction band being populated this is observed for a degenerate electron distribution such as that found in some degenerate semiconductors and is known as a burstein – moss shift the effect occurs when the electron carrier concentration exceeds the conduction band edge density of states which corresponds to degenerate doping in semiconductors in nominally doped semiconductors the fermi level lies between the conduction and valence bands as the doping concentration is increased electrons populate states within the conduction band which pushes the fermi level higher in energy and in the case of degenerate level of doping the fermi level lies inside the conduction band the apparent band gap of a semiconductor can be measured using transmission reflection spectroscopy in the case of a degenerate semiconductor an electron from the top of the valence band can only be excited into conduction band above the fermi level which now lies in conduction band since all the states below the fermi level are occupied states pauli s exclusion principle forbids excitation into these occupied states thus we observe an increase in the apparent band gap apparent band gap actual band gap moss burstein shift as shown in the figure also we have negative burstein shifts which are due to the interactions terms created by adding the extra charges through doping 2 file mbshift for wiki jpg
buruli ulcer also known as the bairnsdale ulcer searls ulcer or daintree ulcer is an infectious disease caused by mycobacterium ulcerans the early stage of the infection is characterised by a painless nodule or area of swelling this nodule can turn into an ulcer the ulcer may be larger inside than at the surface of the skin and can be surrounded by swelling as the disease worsens bone can be infected buruli ulcers most commonly affect the arms or legs fever is uncommon m ulcerans releases a toxin known as mycolactone which decreases immune system function and results in tissue death bacteria from the same family also cause tuberculosis and leprosy m tuberculosis and m leprae respectively how the disease is spread is not known sources of water may be involved in the spread as of 2013 there is no effective vaccine if people are treated early antibiotics for eight weeks are effective in 80 the treatment often includes the medications rifampicin and streptomycin clarithromycin or moxifloxacin are sometimes used instead of streptomycin other treatments may include cutting out the ulcer after the infection heals the area typically has a scar buruli ulcers occurs most commonly in rural sub saharan africa especially cote d ivoire but can also occur in asia the western pacific and the americas cases have occurred in more than 32 countries about five to six thousand cases occur every year the disease also occurs in a number of animals other than humans albert ruskin cook was the first to describe buruli ulcers in 1897
buschke – ollendorff syndrome also known as dermatofibrosis lenticularis disseminata is a rare genetic disorder associated with lemd 3 it is believed to be inherited in an autosomal dominant manner it is named for abraham buschke and helene ollendorff curth who described it in a 45 year old woman its frequency is almost 1 case per every 20 000 people and is equally found in both males and females
business process customization is a function in process management software such as erp oa and itil to allow enterprises to customize their work flows in different software in order to make the software adapt to companies ’ existing work flows
busy line interrupt also known as emergency breakthrough is a function on land line telephones that allows a caller to interrupt a phone conversation of another caller especially one who does not have call waiting much like long distance calling before the late 90 s busy line interrupt is a service provided for instance to allow people to contact a family member in the event of an emergency if the receiving party s line is busy and the news cannot wait the service is not free and is charged whether or not the calling party can reach the person on the other end as the phone just might be off the hook for privacy reasons or the line might be connected to the internet for this reason it is usually only used in cases of emergencies as noted above in the early 1990 s reports were surfacing that phone phreakers were having success in manipulating the line interruption function with signaling tones and equipment that emulated the telephone operator s it was claimed to be possible to eavesdrop on any engaged telephone line by number
busy override is a function of the private branch exchange that allows the calling party to override the busy signal on the called party in order to break into the ongoing conversation before breaking in most pbx announce the incoming call by a distinctive sound signal or tone but in most cases this can be disabled by software the busy override function was originally intended to allow the called party to receive a high priority implying that the call is very important and should be handled first the same feature is often provided for toll long distance operators
butcher s wart is a cutaneous condition with a prevalence of 8 5 to 23 8 among butchers and other meat handling professions caused by a small group of viruses that infect the skin an association with human papillomavirus 7 has been suggested
butt rot is a disease of plants mostly trees caused by fungi the fungus attacks the moist poorly protected undersurface of tree trunk s thickest part the butt above the root as opposed to top where the end of the stem makes contact with the soil it may affect the roots as well causing a disease known as root rot it then moves up into the interior of the plant producing a roughly conical column of dead rotted plant matter up to one and a half meters long in severe cases such an infection is likely to impair the transport properties of the xylem tissue found at the center of the stem it also weakens the stem and makes the plant more vulnerable to toppling one particularly virulent species of fungus associated with butt rot is serpula himantioides
butterflies in the stomach is the physical sensation in humans of a fluttery feeling in the stomach caused by a reduction of blood flow to the organ this is as a result of the release of adrenaline in the fight or flight response which causes increased heart rate and blood pressure consequently sending more blood to the muscles
the butterfly effect is the phenomenon in chaos theory whereby a minor change in circumstances can cause a large change in outcome the butterfly metaphor was created by edward norton lorenz to emphasize the inherent unpredictable results of small changes in the initial conditions of certain physical systems the concept was taken up by popular culture and interpreted to mean that each event could be explained by some small cause or that small events have a rippling effect that causes much larger events to take place
byssinosis also called brown lung disease or monday fever is an occupational lung disease caused by exposure to cotton dust in inadequately ventilated working environments byssinosis commonly occurs in workers who are employed in yarn and fabric manufacture industries it is now thought that the cotton dust directly causes the disease and some believe that the causative agents are endotoxins that come from the cell walls of gram negative bacteria that grow on the cotton although bacterial endotoxin is a likely cause the absence of similar symptoms in workers in other industries exposed to endotoxins makes this uncertain of the 81 byssinosis related fatalities reported in the united states between 1990 and 1999 48 included an occupation in the yarn thread and fabric industry on the victim s death certificate this disease often occurred in the times of the industrial revolution most commonly young girls working in mills or other textile factories would be afflicted with this disease in the united states from 1996 to 2005 north carolina accounted for about 37 of all deaths caused by byssinosis with 31 followed by south carolina 8 and georgia 7 the term brown lung is a misnomer as the lungs of affected individuals are not brown
the bystander effect or bystander apathy is a social psychological phenomenon that refers to cases in which individuals do not offer any means of help to a victim when other people are present the probability of help is inversely related to the number of bystanders in other words the greater the number of bystanders the less likely it is that any one of them will help several variables help to explain why the bystander effect occurs these variables include ambiguity cohesiveness and diffusion of responsibility
the radiation induced bystander effect bystander effect is the phenomenon in which unirradiated cells exhibit irradiated effects as a result of signals received from nearby irradiated cells in november 1992 hatsumi nagasawa and john b little first reported this radiobiological phenomenon there is evidence that targeted cytoplasmic irradiation results in mutation in the nucleus of the hit cells cells that are not directly hit by an alpha particle but are in the vicinity of one that is hit also contribute to the genotoxic response of the cell population similarly when cells are irradiated and the medium is transferred to unirradiated cells these unirradiated cells show bystander responses when assayed for clonogenic survival and oncogenic transformation this is also attributed to the bystander effect the demonstration of a bystander effect in 3 d human tissues and more recently in whole organisms have clear implication of the potential relevance of the non targeted response to human health this effect may also contribute to the final biological consequences of exposure to low doses of radiation however there is currently insufficient evidence at hand to suggest that the bystander effect promotes carcinogenesis in humans at low doses note that the bystander effect is not the same as the abscopal effect the abscopal effect is a phenomenon where the response to radiation is seen in an organ site distant to the irradiated organ area that is the responding cells are not juxtaposed with the irradiated cells t cells and dendritic cells have been implicated to be part of the mechanism in suicide gene therapy the bystander effect is the ability of the transfected cells to transfer death signals to neighboring tumor cells
bálint s syndrome is an uncommon and incompletely understood triad of severe neuropsychological impairments inability to perceive the visual field as a whole simultanagnosia difficulty in fixating the eyes oculomotor apraxia and inability to move the hand to a specific object by using vision optic ataxia it was named in 1909 for the austro hungarian neurologist and psychiatrist rezső bálint who first identified it bálint s syndrome occurs most often with an acute onset as a consequence of two or more strokes at more or less the same place in each hemisphere therefore it occurs rarely the most frequent cause of complete bálint s syndrome is said by some to be sudden and severe hypotension resulting in bilateral borderzone infarction in the occipito parietal region more rarely cases of progressive bálint s syndrome have been found in degenerative disorders such as alzheimer s disease or certain other traumatic brain injuries at the border of the parietal and the occipital lobes of the brain lack of awareness of this syndrome may lead to a misdiagnosis and resulting inappropriate or inadequate treatment therefore clinicians should be familiar with bálint s syndrome and its various etiologies
located at the pereira family home at calle real 5 bélmez de la moraleda jaén andalusia spain the bélmez faces have been responsible for bringing large numbers of sightseers to bélmez the phenomenon is considered by some parapsychologists the best documented and without doubt the most important paranormal phenomenon in the 20 th century various faces have appeared and disappeared at irregular intervals since 1971 and have been frequently photographed by the local newspapers and curious visitors many bélmez residents believe that the faces were not made by human hand some paranormal investigators believe that it is a thoughtographic phenomenon subconsciously produced by the deceased former owner of the house maría gómez cámara skeptical researchers have performed extensive tests on the faces and believe that fakery has been involved and the images have been applied with lead paint the faces are dismissed as a hoax and it has been suspected that the pereira family may have perpetrated the hoax for financial gain
the böckenförde dilemma german böckenforde diktum is a problem dilemma which claims that in secular states there are obstacles to creation of social capital the dilemma is named after german constitutional judge ernst wolfgang böckenförde
börjeson forssman lehmann syndrome bfls is a rare genetic disease that causes intellectual disability obesity and growth defects
büchi s problem also known as the n squares problem is an open problem from number theory named after the swiss mathematician julius richard büchi it asks whether there is a positive integer m such that every sequence of m or more integer squares whose second difference is constant and equal to 2 is necessarily a sequence of squares of the form x i 2 i 1 2 m for some integer x in 1983 douglas hensley observed that büchi s problem is equivalent to the following does there exist a positive integer m such that for all integers x and a the quantity x n 2 a cannot be a square for more than m consecutive values of n unless a 0
the buchner – curtius – schlotterbeck reaction is the reaction of aldehydes or ketones with aliphatic diazoalkanes to form homologated ketones it was first described by eduard buchner and theodor curtius in 1885 and later by fritz schlotterbeck in 1907 two german chemists also preceded schlotterbeck in discovery of the reaction hans von pechmann in 1895 and viktor meyer in 1905 the reaction has since been extended to the synthesis of β keto esters from the condensation between aldehydes and diazo esters the general reaction scheme is as follows the reaction yields two possible carbonyl compounds i and ii along with an epoxide iii the ratio of the products is determined by the reactant used and the reaction conditions
neutral b meson oscillations or b – b oscillations is one of the manifestations of the neutral particle oscillation a fundamental prediction of the standard model of particle physics it is the phenomenon of b mesons changing or oscillating between their matter and antimatter forms before their decay the bs meson can exist as either a bound state of a strange antiquark and a bottom quark or a strange quark and bottom antiquark the oscillations in the neutral b sector are analogous to the phenomena that produces long and short lived neutral kaons bs – bs mixing was observed by the cdf experiment at fermilab in 2006 and by lhcb at cern in 2011
c value is the amount in picograms of dna contained within a haploid nucleus e g a gamete or one half the amount in a diploid somatic cell of a eukaryotic organism in some cases notably among diploid organisms the terms c value and genome size are used interchangeably however in polyploids the c value may represent two or more genomes contained within the same nucleus greilhuber et al have suggested some new layers of terminology and associated abbreviations to clarify this issue but these somewhat complex additions are yet to be used by other authors
the c 10 k problem is the problem of optimising network sockets to handle a large number of clients at the same time the name c 10 k is a numeronym for concurrently handling ten thousand connections note that concurrent connections are not the same as requests per second though they are similar handling many requests per second requires high throughput processing them quickly while high number of concurrent connections requires efficient scheduling of connections the problem of socket server optimisation has been studied because a number of factors must be considered to allow a web server to support many clients this can involve a combination of operating system constraints and web server software limitations according to the scope of services to be made available and the capabilities of the operating system as well as hardware considerations such as multi processing capabilities a multi threading model or a single threading model can be preferred concurrently with this aspect which involves considerations regarding memory management usually operating system related strategies implied relate to the very diverse aspects of the i o management
a c 2 error is a read error of a compact disc c 2 errors can to a degree be recovered by the hardware error detection and correction scheme a cd drive can have extraction errors when the data on the disc is not readable due to scratches or smudges the drive can compensate by supplying a best guess of what the missing data was then supplying the missing data c 2 error correction is an analysis over many interleaved frames an improvement over c 1 error correction which analyzed just one frame resulting in more accurate data correction c 2 error correction codes are also used by the digital audio tape dat format some copy protection schemes add false c 2 errors to discs to discourage copying
in molecular biology a ccaat box also sometimes abbreviated a caat box or cat box is a distinct pattern of nucleotides with ggccaatct consensus sequence that occur upstream by 60 100 bases to the initial transcription site the caat box signals the binding site for the rna transcription factor and is typically accompanied by a conserved consensus sequence it is an invariant dna sequence at about minus 70 base pairs from the origin of transcription in many eukaryotic promoters genes that have this element seem to require it for the gene to be transcribed in sufficient quantities it is frequently absent from genes that encode proteins used in virtually all cells this box along with the gc box is known for binding general transcription factors both of these consensus sequences belong to the regulatory promoter full gene expression occurs when transcription activator proteins bind to each module within the regulatory promoter protein specific binding is required for the ccaat box activation these proteins are known as ccaat box binding proteins ccaat box binding factors a ccaat box is a feature frequently found before eukaryote coding regions but is not found in prokaryotes
cadasil cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy is the most common form of hereditary stroke disorder and is thought to be caused by mutations of the notch 3 gene on chromosome 19 the disease belongs to a family of disorders called the leukodystrophies the most common clinical manifestations are migraine headaches and transient ischemic attacks or strokes which usually occur between 40 and 50 years of age although mri is able to detect signs of the disease years prior to clinical manifestation of disease
canadian disruptive pattern cadpat french dessin de camouflage canadien dcamc is the computer generated digital camouflage pattern currently used by the canadian forces cf cadpat is designed to reduce the likelihood of detection by night vision devices
camfak syndrome or camak syndrome is an acronym used to describe a rare inherited neurologic disease characterized by peripheral and central demyelination of nerves similar to that seen in cockayne syndrome the name camfak comes from the first letters of the characteristic findings of the disease cataracts microcephaly failure to thrive and kyphoscoliosis the disease may occur with or without failure to thrive and arthrogryposis
cd 25 deficiency or interleukin 2 receptor alpha deficiency is an immunodeficiency disorder associated with mutations in the interleukin 2 receptor alpha cd 25 il 2 ra gene the mutations cause expression of a defective α chain or complete absence thereof an essential part of high affinity interleukin 2 il 2 receptors the result is a syndrome described as ipex like or a scid in one patient deficiency of cd 25 on cd 4 lymphocytes caused significantly impaired sensitivity to il 2 this was demonstrated by a lack of measurable response in anti inflammatory interleukin 10 il 10 secretion to low dose il 2 incubation greatly reduced il 10 secretion compared to healthy humans results in a syndrome comparable to ipex syndrome a type of autoimmunity which is caused by foxp 3 transcription factor dysfunction in addition to ipex like symptoms cd 25 deficiency increases susceptibility to viral infections and possibly fungal and bacterial infections as il 2 is an important inducer of lymphocyte proliferation the absence of highly sensitive il 2 receptors may also significantly hinder activation and clonal expansion of cd 8 and cd 4 lymphocytes and nk cells one case also reported the absence of cd 1 a mhc like glycoprotein involved in the presentation of lipid antigens to t cells in a cd 25 deficient patient furthermore chronic upregulation of anti apoptotic bcl 2 in thymocytes was also described possibly allowing autoreactive t cells to escape deletion
cd 30 cutaneous t cell lymphoma also known as primary cutaneous anaplastic large cell lymphoma is a cutaneous skin condition characterized by solitary or localized skin lesions that have a tendency to ulcerate
charge syndrome formerly known as charge association is a rare syndrome caused by a genetic disorder first described in 1979 the acronym charge came into use for newborn children with the congenital features of coloboma of the eye heart defects atresia of the nasal choanae retardation of growth and or development genital and or urinary abnormalities and ear abnormalities and deafness these features are no longer used in making a diagnosis of charge syndrome but the name remains about two third of cases are due to a chd 7 mutation charge syndrome occurs only in 0 1 – 1 2 per 10 000 live births as of 2009 it was the leading cause of congenital deafblindness in the us
congenital hemidysplasia with ichthyosiform erythroderma and limb defects also known as child syndrome is a genetic disorder with onset at birth seen almost exclusively in females the disorder is related to cpdx 2 and also has skin and skeletal abnormalities distinguished by a sharp midline demarcation of the ichthyosis with minimal linear or segmental contralateral involvement the acronym was introduced in 1980
the cia invert is a one dollar value postage stamp error issued by the united states postal service it is one stamp from the americana series that were produced between 1975 and 1981 the 1 colonial rushlight holder stamp was first issued on july 2 1979 and one pane of 100 stamps was issued with the dark brown the last color printed though it covers much of the stamp inverted the lamp candle holder candle outline and text are inverted relative to the flame about 95 copies have been accounted for the scott catalogue number is 1610 c this was the first united states stamp issued with a major design element printed upside down since the dag hammarskjöld invert error of 1962 as these 1 stamps were printed in sheets of 400 three additional panes of 100 stamps certainly existed at one time but no trace of these has so far been discovered when the one known pane of this invert was discovered in the spring of 1986 it had already been on sale at the mclean virginia post office for some time without anyone noticing the error indeed five of its one hundred stamps had been sold by unsuspecting clerks and the portion of the selvage bearing the plate number was no longer attached in this incomplete form the pane was purchased by an employee of the cia who had been sent to the post office to buy stamps for the agency the purchaser failed at first to notice that the flames were inverted relative to the candle holder and lettering only several days later was the error discovered by a cia employee who needed a 1 stamp for an agency mailing once this man had shared his information with eight colleagues the nine decided to acquire the error stamps for themselves purchasing 95 normal 1 stamps the group exchanged these for the cia ’ s inverts they then revealed their find to an annandale virginia stamp dealer ike snyder who referred them to a new jersey stamp specialist jacques c schiff jr eventually the group struck a deal with schiff each of the nine employees kept a single inverted stamp schiff paid a reported 25 000 for which he received a block of 85 inverts along with a single stamp that had been damaged initially schiff shielded the members of the group from scrutiny announcing that the fourteen stamps from the sheet not sold to him had all been used on cia mailings however after the true story surfaced in the mass media revealed by the new york times and cbs news the stamp became known as the cia invert and the agency was obliged to make its own investigation ultimately the cia demanded that the nine employees return their inverts to the agency stating anyone who failed to comply would be terminated four returned their stamps and kept their jobs four refused and were fired while the ninth claimed that he had lost his stamp and remained a cia employee stamp catalogs list its price as only 15 000 one tenth of the inverted jenny that is valued at 150 000 despite the fact that about the same number of each stamp exist a block of four stamps sold in 2004 for 60 000 reproductions have been sold on ebay
cmv polyradiculomyelopathy pram is one of the five distinct neurological syndromes caused by cmv in hiv aids it causes subacute ascending lower extremity weakness with paresthesias and radicular pain hyporeflexia or areflexia and urinary retention it has been suggested that cmv polyradiculomyelopathy should be treated with both ganciclovir and foscarnet in patients who develop the disease while taking either of these drugs
cns demyelinating autoimmune diseases are autoimmune diseases which primarily affect the central nervous system examples include diffuse cerebral sclerosis of schilder acute disseminated encephalomyelitis acute hemorrhagic leukoencephalitis multiple sclerosis though etiology is unknown it is sure that immune system is involved transverse myelitis neuromyelitis optica
coach syndrome is a rare autosomal recessive disorder characterised by cerebellar vermis hypoplasia oligophrenia developmental delay mental retardation ataxia coloboma and hepatic fibrosis the vermis hypoplasia falls in a spectrum of mid hindbrain malformation called the molar tooth sign mts making coach a joubert syndrome related disorder jsrd due to mutation in the gene tmem 67 in majority of cases renal insufficiency was also found in some cases
cpu time or process time is the amount of time for which a central processing unit cpu was used for processing instructions of a computer program or operating system as opposed to for example waiting for input output i o operations or entering low power idle mode the cpu time is measured in clock ticks or seconds often it is useful to measure cpu time as a percentage of the cpu s capacity which is called the cpu usage cpu time and cpu usage have two main uses the first use is to quantify the overall busyness of the system when the cpu usage is above 70 the user may experience lag such high cpu usage indicates insufficient processing power either the cpu needs to be upgraded or the user experience reduced for example by switching to lower resolution graphics or reducing animations the second use with the advent of multi tasking is to quantify how the processor is shared between computer programs high cpu usage by a single program may indicate that it is highly demanding of processing power or that it may malfunction for example it has entered an infinite loop cpu time allows to measure how much processing power a single program requires eliminating interference such as time executed waiting for input or being suspended to allow other programs to run in contrast elapsed real time or simply real time or wall clock time is the time taken from the start of a computer program until the end as measured by an ordinary clock elapsed real time includes i o time and all other types of waits incurred by the program
crest syndrome also known as the limited cutaneous form of systemic sclerosis lcssc is a multisystem connective tissue disorder the acronym crest refers to the five main features calcinosis raynaud s phenomenon esophageal dysmotility sclerodactyly and telangiectasia it is associated with detectable antibodies against centromeres a component of the cell nucleus and usually spares the kidneys a feature more common in the related condition systemic scleroderma if the lungs are involved it is usually in the form of pulmonary arterial hypertension
cachexia from greek κακός kakos bad and ἕξις hexis condition or wasting syndrome is loss of weight muscle atrophy fatigue weakness and significant loss of appetite in someone who is not actively trying to lose weight the formal definition of cachexia is the loss of body mass that cannot be reversed nutritionally even if the affected patient eats more calories lean body mass will be lost indicating a primary pathology is in place cachexia is seen in patients with cancer aids coeliac disease chronic obstructive pulmonary disease multiple sclerosis rheumatoid arthritis congestive heart failure tuberculosis familial amyloid polyneuropathy mercury poisoning acrodynia and hormonal deficiency it is a positive risk factor for death meaning if the patient has cachexia the chance of death from the underlying condition is increased dramatically it can be a sign of various underlying disorders when a patient presents with cachexia a doctor will generally consider the possibility of adverse drug reactions cancer metabolic acidosis certain infectious diseases e g tuberculosis aids chronic pancreatitis and some autoimmune disorders cachexia physically weakens patients to a state of immobility stemming from loss of appetite asthenia and anemia and response to standard treatment is usually poor cachexia includes sarcopenia as a part of its pathology
cadang cadang is a disease caused by coconut cadang cadang viroid cccvd a lethal viroid of coconut cocos nucifera anahaw livistona rotundifolia buri corypha utan and african oil palm elaeis guineensis the name cadang cadang comes from the word gadang gadang that means dying in bicol it was originally reported on san miguel island in the philippines in 1927 1928 by 1962 all but 100 of 250 000 palms on this island had died from the disease indicating an epidemic every year one million coconut palms are killed by cccvd and over 30 million coconut palms have been killed since cadang cadang has been discovered cccvd directly affects the production of copra a raw material for coconut oil and animal feed total losses of about 30 million palms and annual yield losses of about 22 000 tons of copra have been attributed to cadang cadang disease in the philippines
the cadiot – chodkiewicz coupling in organic chemistry is a coupling reaction between a terminal alkyne and a haloalkyne catalyzed by a copper i salt such as copper i bromide and an amine base the reaction product is a di acetylene or di alkyne the reaction mechanism involves deprotonation by base of the acetylenic proton followed by formation of a copper i acetylide a cycle of oxidative addition and reductive elimination on the copper center then creates a new carbon carbon bond related couplings are the glaser coupling and the eglinton coupling
in the 1950 s and 1960 s industrial exposure to cadmium was high but as the toxic effects of cadmium became apparent industrial limits on cadmium exposure have been reduced in most industrialized nations and many policy makers agree on the need to reduce exposure further while working with cadmium it is important to do so under a fume hood to protect against dangerous fumes brazing fillers which contain cadmium should be handled with care serious toxicity problems have resulted from long term exposure to cadmium plating baths buildup of cadmium levels in the water air and soil has been occurring particularly in industrial areas environmental exposure to cadmium has been particularly problematic in japan where many people have consumed rice that was grown in cadmium contaminated irrigation water this phenomenon is known under the name itai itai disease food is another source of cadmium plants may only contain small or moderate amounts in non industrial areas but high levels may be found in the liver and kidneys of adult animals the daily intake of cadmium through food varies by geographic region intake is reported to be approximately 8 to 30 μg in europe and the united states versus 59 to 113 μg in various areas of japan cigarettes are also a significant source of cadmium exposure although there is generally less cadmium in tobacco than in food the lungs absorb cadmium more efficiently than the stomach aside from tobacco smokers people who live near hazardous waste sites or factories that release cadmium into the air have the potential for exposure to cadmium in air however numerous state and federal regulations in the united states control the amount of cadmium that can be released to the air from waste sites and incinerators so that properly regulated sites are not hazardous the general population and people living near hazardous waste sites may be exposed to cadmium in contaminated food dust or water from unregulated releases or accidental releases numerous regulations and use of pollution controls are enforced to prevent such releases workers can be exposed to cadmium in air from the smelting and refining of metals or from the air in plants that make cadmium products such as batteries coatings or plastics workers can also be exposed when soldering or welding metal that contains cadmium approximately 512 000 workers in the united states are in environments each year where a cadmium exposure may occur regulations that set permissible levels of exposure however are enforced to protect workers and to make sure that levels of cadmium in the air are considerably below levels thought to result in harmful effects artists who work with cadmium pigments which are commonly used in strong oranges reds and yellows can easily accidentally ingest dangerous amounts particularly if they use the pigments in dry form as with chalk pastels or in mixing their own paints some sources of phosphate in fertilizers contain cadmium in amounts of up to 100 mg kg which can lead to an increase in the concentration of cadmium in soil for example in new zealand nickel cadmium batteries are one of the most popular and most common cadmium based products and this soil can be mined for use in them an experiment during the early 1960 s involving the spraying of cadmium over norwich has recently been declassified by the uk government as documented in a bbc news article in february 2010 cadmium was found in an entire line of wal mart exclusive miley cyrus jewelry the charms were tested at the behest of the associated press and were found to contain high levels of cadmium wal mart did not stop selling the jewelry until may 12 because it would be too difficult to test products already on its shelves on june 4 cadmium was detected in the paint used on promotional drinking glasses for the movie shrek forever after sold by mcdonald s restaurants triggering a recall of 12 million glasses
cesarean delivery on maternal request cdmr is a caesarean section birth requested by the pregnant woman without a medical reason
caffeine induced anxiety disorder is an anxiety disorder that can be present in people susceptible to panic attacks and anxiety consumption of caffeine has long been linked to anxiety caffeine induced anxiety disorder however almost exclusively occurs in people who already have an anxiety disorder for these people they are more prone to the psychological effects of caffeine and are at greater risk of a panic attack after ingesting non trivial amounts of caffeine the effects of caffeine and the symptoms of anxiety both increase activity within the sympathetic nervous system caffeine has been linked to the aggravation and maintenance of anxiety disorders and the initiation of panic or anxiety attacks in those who are already predisposed to such phenomena caffeine usage surpassing 200 mg has been shown to increase the likelihood for anxiety and panic attacks in a population excessive amounts of caffeine can result in symptoms from general anxiety to obsessive compulsive and phobic symptoms anxiety symptoms caused by caffeine are often mistaken for serious mental disorders including bipolar disorder and schizophrenia leaving patients medicated for the wrong issue
caffeine induced sleep disorder is a psychiatric disorder that results from overconsumption of the stimulant caffeine when caffeine is consumed immediately before bedtime or continuously throughout the day sleep onset may be delayed total sleep time reduced normal stages of sleep altered and the quality of sleep decreased caffeine reduces slow wave sleep in the early part of the sleep cycle and can reduce rapid eye movement sleep later in the cycle caffeine increases episodes of wakefulness and high doses in the late evening can increase sleep onset latency in elderly people there is an association between use of medication containing caffeine and difficulty in falling asleep the specific criteria for this disorder in the fourth version of the diagnostic and statistical manual of mental disorders dsm iv include that there must be a significant inability to sleep which is caused entirely by the physiological effects of caffeine as proven by an examination if sleeping issues can be accounted for due to a breathing related sleep disorder narcolepsy a circadian rhythm sleep disorder or a mental disorder then caffeine induced sleep disorder is not the cause this condition causes a notable impairment in functioning in sufferers excessive ingestion of caffeine can lead to a state of intoxication this period of intoxication is characterized by restlessness agitation excitement rambling thought or speech and even insomnia even doses of caffeine relating to just one cup of coffee can increase sleep latency and decrease the quality of sleep especially in non rem deep sleep a dose of caffeine taken in the morning can have these effects the following night so one of the main practices of sleep hygiene a person can do is to cease the consumption of caffeine
caffeine s mechanism of action is somewhat different from that of cocaine and the substituted amphetamines caffeine blocks adenosine receptors a and a 2 a adenosine is a by product of cellular activity and stimulation of adenosine receptors produces feelings of tiredness and the need to sleep caffeine s ability to block these receptors means the levels of the body s natural stimulants dopamine and norepinephrine continue at higher levels
café au lait spots or café au lait macules are flat pigmented birthmarks the name café au lait is french for coffee with milk and refers to their light brown color they are also called giraffe spots or coast of maine spots they are caused by a collection of pigment producing melanocytes in the epidermis of the skin these spots are typically permanent and may grow or increase in number over time café au lait spots are often harmless but may be associated with syndromes such as neurofibromatosis type 1 and mccune albright syndrome
the calaveras skull was a human skull found by miners in calaveras county california which was purported to prove that humans mastodons and elephants had coexisted in california it was later revealed to be a hoax coincidentally calaveras is the spanish word for skulls
calcaneal fracture is a fracture of the calcaneus it is usually caused by a fall from height when one lands on their feet these fractures represent approximately 2 of all fractures but 60 of tarsal bone fractures the name lover s fracture is derived from the fact that a lover may jump from great heights while trying to escape from the lover s spouse
a calcaneal spur or heel spur is a small osteophyte bone spur located on the calcaneus heel bone calcaneal spurs are typically detected by a radiological examination x ray when a foot bone is exposed to constant stress calcium deposits build up on the bottom of the heel bone generally this has no effect on a person s daily life however repeated damage can cause these deposits to pile up on each other causing a spur shaped deformity called a calcaneal or heel spur obese people flatfooted people and people who often wear high heeled shoes are most susceptible to heel spurs an inferior calcaneal spur is located on the inferior aspect of the calcaneus and is typically a response to plantar fasciitis over a period but may also be associated with ankylosing spondylitis typically in children a posterior calcaneal spur develops on the back of the heel at the insertion of the achilles tendon an inferior calcaneal spur consists of a calcification of the calcaneus which lies superior to the plantar fascia at the insertion of the plantar fascia a posterior calcaneal spur is often large and palpable through the skin and may need to be removed as part of the treatment of insertional achilles tendonitis these are also generally visible to the naked eye
calcareous dinoflagellate cysts or calcareous dinocysts are dinoflagellate cysts produced by a group of peridinoid dinoflagellates called calcareous dinoflagellates
calcific tendinitis is a form of tendinitis a disorder characterized by deposits of hydroxyapatite a crystalline calcium phosphate in any tendon of the body but most commonly in the tendons of the rotator cuff shoulder causing pain and inflammation the condition is related to and may cause adhesive capsulitis frozen shoulder
calcification is the accumulation of calcium salts in a body tissue it normally occurs in the formation of bone but calcium can be deposited abnormally in soft tissue causing it to harden calcifications may be classified on whether there is mineral balance or not and the location of the calcification calcification may also refer to the processes of normal mineral deposition in biological systems such as the formation of stromatolites or mollusc shells see mineralization biology or biomineralization
the calcifying epithelial odontogenic tumor also known as a pindborg tumor or ceot is an odontogenic tumor first recognized by the danish pathologist jens jørgen pindborg in 1955 it was previously described as an adenoid adamantoblastoma unusual ameloblastoma and a cystic odontoma like other odontogenic neoplasms it is thought to arise from the epithelial element of the enamel origin it is a typically benign and slow growing but invasive neoplasm
the calcifying odotogenic cyst or the gorlin cyst now known in the who classification of tumours as the calcifying cystic odontogenic tumor is a benign odontogenic tumor of cystic type most likely to affect the anterior areas of the jaws it is most common in people in their second to third decades but can be seen at almost any age on radiographs the calcifying odontogenic cyst appears as a unilocular radiolucency dark area in one third of cases an impacted tooth is involved microscopically there are many cells that are described as ghost cells enlarged eosinophilic epithelial cells without nuclei
calcinosis is the formation of calcium deposits in any soft tissue
calcinosis cutis or cutaneous calcification is a type of calcinosis wherein calcium deposits form in the skin a variety of factors can result in this condition the most common source is dystrophic calcification which occurs in soft tissue as a response to injury in addition calcinosis is seen in limited cutaneous systemic sclerosis also known as crest syndrome the c in crest in dogs calcinosis cutis is found in young large breed dogs and is thought to occur after a traumatic injury
calciothermic reactions are metallothermic reduction reactions more generally thermic chemical reactions which use calcium metal as the reducing agent at high temperature calcium is one of the most potent reducing agents available usually drawn as the strongest oxidic reductant in ellingham diagrams though the lanthanides best it in this respect in oxide processes on the other hand this trend does not continue to other compounds that are non oxides and for instance lanthanum is produced by the calciothermic reduction of the chloride calcium being a more potent reducing agent than lanthanum involving chlorides calciothermic processes are used in the extraction of metals such as uranium zirconium and thorium from oxide ores an interesting way of performing calciothermic reductions is by in situ generated metallic calcium dissolved in molten calcium chloride as shown in the ffc cambridge process
calciphylaxis or calcific uremic arteriolopathy cua is a syndrome of vascular calcification thrombosis and skin necrosis it is seen mostly in patients with stage 5 chronic kidney disease but can occur in the absence of renal failure it results in chronic non healing wounds and is usually fatal calciphylaxis is a rare but serious disease believed to affect 1 4 of all dialysis patients calciphylaxis is one type of extraskeletal calcification similar extraskeletal calcifications are observed in some patients with hypercalcemic states including patients with milk alkali syndrome sarcoidosis primary hyperparathyroidism and hypervitaminosis d
calcium channel blocker toxicity is the taking of too much of the medications known as calcium channel blockers ccbs either by accident or on purpose this often causes a slow heart rate and low blood pressure this can progress to the heart stopping altogether some ccbs can also cause a fast heart rate as a result of the low blood pressure other symptoms may include nausea vomiting sleepiness and shortness of breath symptoms usually occur in the first six hours but with some forms of the medication may not start until 24 after hours there are a number of treatments that may be useful these include efforts to reduce absorption of the drug including activated charcoal taken by mouth if given shortly after the ingestion or whole bowel irrigation if an extended release formula was taken efforts to cause vomiting are not recommended medications to treat the toxic effects include intravenous fluids calcium gluconate glucagon high dose insulin vasopressors and lipid emulsion extracorporeal membrane oxygenation may also be an option more than ten thousand cases of calcium channel blocker toxicity were reported in the united states in 2010 along with beta blockers and digoxin calcium channel blockers have one of the highest rates of death in overdose these medications first became available in the 1970 s and 1980 s they are one of the few types of medication in which one pill can result in the death of a child
calcium ca deficiency is a plant disorder that can be caused by insufficient calcium in the growing medium but is more frequently a product of low transpiration of the whole plant or more commonly the affected tissue plants are susceptible to such localized calcium deficiencies in low or non transpiring tissues because calcium is not transported in the phloem this may be due to water shortages which slow the transportation of calcium to the plant poor uptake of calcium through the stem or too much nitrogen in the soil
a calciumopathy is a disease caused by disruption to the use of calcium within a cell to a large extent a calciumopathy is a type of channelopathy or a disease caused by disturbed function of ion channel subunits or the proteins that regulate them calciumopathies also include dysfunctions of regulatory pathways and mitochondria many calciumopathies are complex polygenic diseases clues to their understanding are coming from the rarer monogenic forms of common symptoms such as seizures ataxia and migraine
a calculus plural calculi often called a stone is a concretion of material usually mineral salts that forms in an organ or duct of the body formation of calculi is known as lithiasis ˌlɪˈθaɪəsᵻs stones can cause a number of medical conditions some common principles below apply to stones at any location but for specifics see the particular stone type in question calculi are not to be confused with gastroliths
a calibrated orifice is a restriction that is deliberately placed into a system of pipes to set the flow rate through the system the orifice may be designed to produce proportional flow as in the jet in a carburetor or choked flow as in a filtering bypass in a closed industrial cooling system which might be designed to pass a particular flow rate through a filter assembly to maintain cleanliness of a closed loop fluid system many pressure gauges also use an orifice also called a restrictor to limit the flow into a gauge since the pressure is even throughout the system allowing only a small portion of the flow into the actual gauge allows it to be in parallel with the pressure circuit and still measure accurately it also prevents or minimizes damage to the gauge during pressure surges at start up or due to any spikes in the system pressure
the california genocide is a term used to describe the decrease in the indigenous population of california due to violence relocation and starvation as a result of the u s occupation of california the indigenous population of california under spanish rule dropped from 300 000 prior to 1769 to 250 000 in 1834 after mexico won its independence from spain and after the secularization of the coastal missions by the mexican government in 1834 the indigenous population suffered a much more drastic decrease in population the period immediately following the u s conquest of california has been characterized by numerous sources as a genocide under us sovereignty after 1848 the indian population plunged from perhaps 150 000 to 30 000 in 1870 and reached its nadir of 16 000 in 1900
for astronomy and calendar studies the callippic cycle or calippic is a particular approximate common multiple of the year specifically the tropical year and the synodic month that was proposed by callippus during 330 bc it is a period of 76 years as an improvement of the 19 year metonic cycle a century before callippus meton discovered the cycle of 19 years that counted 6 940 days which exceeds 235 lunations by almost a third of a day and 19 tropical years by four tenths of a day it implicitly gave the solar year a duration of 6940 ⁄ 19 365 1 ⁄ 4 1 ⁄ 76 days 365 d 6 h 18 min 56 s but callippus knew that the duration of the year was more closely 365 1 ⁄ 4 days 365 d 6 h so he multiplied the 19 year cycle by 4 to obtain an integer number of days and then omitted 1 day from the last 19 year cycle thus he computed a cycle of 76 years that consists of 940 lunations and 27 759 days and has been named the callippic cycle for him although the cycle s error has been computed as one full day in 553 years or 4 95 parts per million in actuality 27 759 days in 76 years has a mean year of exactly 365 1 ⁄ 4 days which relative to the mean northward equinoctial year is about 11 minutes too long per year in other words the cycle drifts another day late per 130 10 ⁄ 11 years which is considerably worse than the drift of the unrounded metonic cycle if the callippic cycle is considered as closer to its unrounded length of 27 758 3 ⁄ 4 days based on 940 lunations then its accuracy is essentially the same as the unrounded metonic cycle within a few seconds per year if it is considered as 940 lunations less one day then the callippic mean year will be shortened by 1 ⁄ 76 of a day 18 minutes 57 seconds making it grossly too short and it will also grossly drift ahead with respect to the mean lunar cycle at the rate of 1 ⁄ 940 of a day 1 minute 31 seconds per lunar month if the cycle length is truncated to 27 758 days then the mean year is 365 days 5 hours 41 minutes 3 seconds or almost 8 minutes too brief per year and it will drift ahead of the mean lunar cycle by about 3 ⁄ 4 ⁄ 940 day 1 minute 9 seconds per lunar month altogether the purported accuracy of this cycle is not impressive but it is of historical interest the first year of the first callippic cycle began at the summer solstice of 330 bc 28 june in the proleptic julian calendar and was subsequently used by later astronomers in ptolemy s almagest for example he cites almagest vii 3 h 25 observations by timocharis during the 47 th year of the first callippic cycle 283 bc when on the eighth of anthesterion the pleiades star cluster was occulted by the moon the callippic calendar originally used the names of months from the attic calendar although later astronomers such as hipparchus preferred other calendars including the egyptian calendar also hipparchus invented his own hipparchic calendar cycle as an improvement upon the callippic cycle ptolemy s almagest provided some conversions between the callippic and egyptian calendars such as that anthesterion 8 47 th year of the first callippic period was equivalent to day 29 of the month of athyr during year 465 of nabonassar however the original complete form of the callippic calendar is no longer known
callous ulcer is a chronic nonhealing ulcer with hard indurated base and inelastic margins it usually contains unhealthy pale granulation tissue it may last for months to years and does not show any tendency to heal
a callus or callosity is a toughened area of skin which has become relatively thick and hard in response to repeated friction pressure or other irritation rubbing that is too frequent or forceful will cause blisters rather than allow calluses to form since repeated contact is required calluses are most often found on feet because of frequent walking calluses are generally not harmful but may sometimes lead to other problems such as skin ulceration or infection
camelpox is a disease of camels caused by a virus of the family poxviridae subfamily chordopoxvirinae and the genus orthopoxvirus it causes skin lesions and a generalized infection approximately 25 of young camels that become infected will die from the disease while infection in older camels is generally more mild although rare the infection may spread to the hands of those that work closely with camels camelpox is endemic throughout the middle east africa and asia
a cameo role or cameo appearance ˈkæmioʊ often shortened to just cameo is a brief appearance or voice part of a known person in a work of the performing arts typically unnamed or appearing as themselves these roles are generally small many of them non speaking ones and are commonly either appearances in a work in which they hold some special significance such as actors from an original movie appearing in its remake or renowned people making uncredited appearances short appearances by celebrities film directors politicians athletes or musicians are common a crew member of the show or movie playing a minor role can be referred to as a cameo as well such as alfred hitchcock s frequently performed cameos
camera coverage in filmmaking and video production is the amount of footage shot and different camera angles used to capture a scene when in the post production process the more camera coverage means that there is more footage for the film editor to work with in assembling the final cut
camisa disease or vohwinkel variant with ichthyosis is the variant form of vohwinkel syndrome characterized by ichthyosis and normal hearing it is associated with loricrin it was characterized in 1984 and 1988
campomelic dysplasia cmd is a rare genetic disorder characterized by bowing of the long bones and many other skeletal and extraskeletal features it is frequently lethal in the neonatal period due to respiratory insufficiency but the severity of the disease is variable and some patients survive into adulthood the name is derived from the greek roots campo or campto meaning bent and melia meaning limb an unusual aspect of the disease is that up to two thirds of affected 46 xy genotypic males display a range of disorders of sexual development dsd and genital ambiguities or may even develop as normal phenotypic females as in complete 46 xy sex reversal an atypical form of the disease with absence of bowed limbs is called prosaically acampomelic campomelic dysplasia acd and is found in about 10 of patients particularly those surviving the neonatal period
the camps quinoline synthesis also known as the camps cyclization is a chemical reaction whereby an o acylaminoacetophenone is transformed into two different hydroxyquinolines products a and b using hydroxide ion the camps quinoline synthesis the relative proportions of the hydroxyquinolines a and b produced are dependent upon the reaction conditions and structure of the starting material although the reaction product is commonly depicted as a quinoline the enol form it is believed that the keto form predominates in both the solid state and in solution making the compound a quinolone an example of the camps reaction is given below camps quinoline synthesis
camptocormia also known as bent spine syndrome bss is a symptom of a multitude of diseases that is most commonly seen in the elderly it is identified by an abnormal thoracolumbar spinal flexion which is a bending of the lower muscles of the back occurring in a standing position in order to be classified as bss the anterior flexion the lower back bending must be of 45 degrees anteriorly this classification differentiates it from a similar syndrome known as kyphosis although camptocormia is a symptom of many diseases there are two common origins neurological and muscular camptocormia is treated by alleviating the underlying condition causing it through theraputic measures or lifestyle changes
camptodactyly is a medical condition that causes one or more fingers to be permanently bent it involves fixed flexion deformity of the proximal interphalangeal joints the fifth finger is always affected camptodactyly can be caused by a genetic disorder in that case it is an autosomal dominant trait that is known for its incomplete genetic expressivity this means that when a person has the genes for it the condition may appear in both hands one or neither a linkage scan proposed that the chromosomal locus of camptodactyly was 3 q 11 2 q 13 12
camptodactyly arthropathy coxa vara pericarditis syndrome is a rare genetic condition due to a mutation in the gene proteoglycan 4 prg 4 a chondroitin sulfate proteoglycan that acts as a lubricant for the cartilage surfaces this gene is also known as lubricin this condition is inherited as an autosomal recessive
campylobacteriosis is an infection by the campylobacter bacterium most commonly c jejuni it is among the most common bacterial infections of humans often a foodborne illness it produces an inflammatory sometimes bloody diarrhea or dysentery syndrome mostly including cramps fever and pain
camurati – engelmann disease ced is a very rare autosomal dominant genetic disorder that causes characteristic anomalies in the skeleton it is a form of dysplasia patients typically have heavily thickened bones especially along the shafts of the long bones called diaphyseal dysplasia the skull bones may be thickened so that the passages through the skull that carry nerves and blood vessels become narrowed possibly leading to sensory deficits blindness or deafness this disease often appears in childhood and is considered to be inherited however some patients have no previous history of ced within their family the disease is slowly progressive and while there is no cure there is treatment it is named for m camurati and g engelmann camurati – engelmann disease is also known as engelmann disease ed engelmann syndrome es camurati – engelmann syndrome ces or progressive diaphyseal dysplasia pdd which are the most common alternative names of the disease other names include osteopathia hyperostotica scleroticans and multiplex infantalis
canadian import duties is the amount of tax or tariff paid while importing goods into canada the canada border services agency collects the tariff on all imported goods according to the north american free trade agreement there is no duty to be paid if the goods are for personal use and the goods are marked as made in the united states canada or mexico or the goods are not marked or labelled to indicate that they were made anywhere other than in the united states canada or mexico canadians also have to pay the federal goods and services tax and in most provinces provincial sales tax on the imported goods
the canadian government debt commonly called the public debt or the national debt is the amount of money owed by the government of canada to holders of canadian treasury security in 2013 this number stood at cad 1 2 trillion across federal and provincial governments with the total gdp somewhere around cad 1 8 trillion canada s overall debt gdp ratio is around 66 gross debt is the national debt plus intragovernmental debt obligations or debt held by trust funds types of securities sold by the government include treasury bills notes bonds tips canada savings bonds and provincial government securities the annual government deficit is the difference between government receipts and spending
canalicular adenoma is a type of benign salivary gland tumor that occurs most often in minor salivary glands in addition to pleomorphic adenoma the two are the most common tumors of the upper lip
canavan disease also called canavan van bogaert bertrand disease is an autosomal recessive degenerative disorder that causes progressive damage to nerve cells in the brain and is one of the most common degenerative cerebral diseases of infancy it is caused by a deficiency of the enzyme aminoacylase 2 and is one of a group of genetic diseases referred to as a leukodystrophies it is characterized by degeneration of myelin in the phospholipid layer insulating the axon of a neuron and is associated with a gene located on human chromosome 17
cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body not all tumors are cancerous benign tumors do not spread to other parts of the body possible signs and symptoms include a lump abnormal bleeding prolonged cough unexplained weight loss and a change in bowel movements while these symptoms may indicate cancer they may have other causes over 100 cancers affect humans tobacco use is the cause of about 22 of cancer deaths another 10 is due to obesity poor diet lack of physical activity and drinking alcohol other factors include certain infections exposure to ionizing radiation and environmental pollutants in the developing world nearly 20 of cancers are due to infections such as hepatitis b hepatitis c and human papillomavirus hpv these factors act at least partly by changing the genes of a cell typically many genetic changes are required before cancer develops approximately 5 – 10 of cancers are due to inherited genetic defects from a person s parents cancer can be detected by certain signs and symptoms or screening tests it is then typically further investigated by medical imaging and confirmed by biopsy many cancers can be prevented by not smoking maintaining a healthy weight not drinking too much alcohol eating plenty of vegetables fruits and whole grains vaccination against certain infectious diseases not eating too much processed and red meat and avoiding too much sunlight exposure early detection through screening is useful for cervical and colorectal cancer the benefits of screening in breast cancer are controversial cancer is often treated with some combination of radiation therapy surgery chemotherapy and targeted therapy pain and symptom management are an important part of care palliative care is particularly important in people with advanced disease the chance of survival depends on the type of cancer and extent of disease at the start of treatment in children under 15 at diagnosis the five year survival rate in the developed world is on average 80 for cancer in the united states the average five year survival rate is 66 in 2012 about 14 1 million new cases of cancer occurred globally not including skin cancer other than melanoma it caused about 8 2 million deaths or 14 6 of human deaths the most common types of cancer in males are lung cancer prostate cancer colorectal cancer and stomach cancer in females the most common types are breast cancer colorectal cancer lung cancer and cervical cancer if skin cancer other than melanoma were included in total new cancers each year it would account for around 40 of cases in children acute lymphoblastic leukaemia and brain tumors are most common except in africa where non hodgkin lymphoma occurs more often in 2012 about 165 000 children under 15 years of age were diagnosed with cancer the risk of cancer increases significantly with age and many cancers occur more commonly in developed countries rates are increasing as more people live to an old age and as lifestyle changes occur in the developing world the financial costs of cancer were estimated at 1 16 trillion us dollars per year as of 2010
cancer related fatigue is a subjective symptom of fatigue that is experienced by nearly all cancer patients among patients receiving cancer treatment other than surgery it is essentially universal fatigue is a normal and expected side effect of most forms of chemotherapy radiation therapy and biotherapy on average cancer related fatigue is more severe more distressing and less likely to be relieved by rest than fatigue experienced by healthy people it can range from mild to severe and may be either temporary or a long term effect fatigue may be a symptom of the cancer or it may be the result of treatments for the cancer
similarly to humans cancer is the leading cause of death among older cats it is caused by uncontrolled cell growth and affects a wide range of cell types and organs in the body feline cancer initially manifests as a lump or bump on any parts of the body it rapidly grows in the affected cell attaches itself to the tissue under the skin in that area and depending on the tumour it can spread to other parts of the body although cancer accounts for approximately 50 of feline deaths each year it can be successfully treated if diagnosed early while the causes of cancer in cats are unknown feline leukemia virus is suspected to be a prime contributor other factors suspected to increase rates of feline cancer include toxins from the environment second hand smoking excessive grooming or licking parts of the body that have been in contact with an environmental toxin cancer can be detected early on by observing for certain signs and symptoms common diagnosing methods include physical examination x rays ultrasounds cytology blood tests urine tests and nuclear scans depending on the type of cancer and its level of progress surgery radiation chemotherapy or immunotherapy may be utilized to treat for cancer although research has been slow for causes and treatment of feline cancers there have been advancements in radiation therapy as well as newer and improved chemotherapy procedures
similarly to humans cancer is the leading cause of death among older dogs it accounts for approximately 50 of deaths each year but can be successfully treated if diagnosed early the medical science that studies cancer in animals is called veterinary oncology and veterinarians that specialize in cancer diagnosis and treatment are called veterinary oncologists as with people dogs can get various kinds of cancer cancer in dogs is one of the leading cause of deaths in dogs but it can be successfully treated
cancer of unknown primary origin cup occult cancer is a term used to describe a cancer that is determined to be at the metastatic stage at the time of diagnosis but a primary tumor cannot be identified a diagnosis of cup requires a clinical picture consistent with metastatic disease and one or more biopsy results inconsistent with a primary tumor cup is found in about 3 to 5 of all people diagnosed with invasive cancer and carries a poor prognosis in most 80 to 85 of those circumstances the other 15 to 20 of patients however have a relatively long survival with appropriate treatment
a cancer syndrome or family cancer syndrome is a genetic disorder in which inherited genetic mutations in one or more genes predispose the affected individuals to the development of cancers and may also cause the early onset of these cancers cancer syndromes often show not only a high lifetime risk of developing cancer but also the development of multiple independent primary tumors many of these syndromes are caused by mutations in tumor suppressor genes genes that are involved in protecting the cell from turning cancerous other genes that may be affected are dna repair genes oncogenes and genes involved in the production of blood vessels angiogenesis common examples of inherited cancer syndromes are hereditary breast ovarian cancer syndrome and hereditary non polyposis colon cancer lynch syndrome
candidal intertrigo is an infection of the skin by candida albicans more specifically located between intertriginous folds of adjacent skin
candidal onychomycosis is an infection of the nail plate by fungus caused by candida in one study candida parapsilosis was the most common species candida albicans is also a common agent
candidiasis is a fungal infection due to any type of candida a type of yeast when it affects the mouth it is commonly called thrush signs and symptoms include white patches on the tongue or other areas of the mouth and throat other symptoms may include soreness and problems swallowing when it affects the vagina it is commonly called a yeast infection signs and symptoms include genital itching burning and sometimes a white cottage cheese like discharge from the vagina less commonly the penis may be affected resulting in itchiness very rarely the infection may become invasive spreading throughout the body resulting in fevers along with other symptoms depending on the parts of the body affected more than 20 types of candida can cause infection with candida albicans being the most common infections of the mouth are most common among children less than one month old the elderly and those with weak immune systems conditions that result in a weak immune system include hiv aids the medications used after organ transplantation diabetes and the use of corticosteroids other risks include dentures and following antibiotic therapy vaginal infections occur more commonly during pregnancy in those with weak immune systems and following antibiotic use risk for widespread infection includes being in an intensive care unit following surgery low birth weight infants and those with weak immune systems efforts to prevent infections of the mouth include the use of chlorhexidine mouth wash in those with poor immune function and washing out the mouth following the use of inhaled steroids little evidence supports probiotics for either prevention or treatment even among those with frequent vaginal infections for infections of the mouth treatment with topical clotrimazole or nystatin is usually effective oral or intravenous fluconazole itraconazole or amphotericin b may be used if these do not work a number of topical antifungal medications may be used for vaginal infections including clotrimazole in those with widespread disease an echinocandin such as caspofungin or micafungin is used a number of weeks of intravenous amphotericin b may be used as an alternative in certain groups at very high risk antifungal medications may be used preventatively infections of the mouth occur in about 6 of babies less than a month old about 20 of those receiving chemotherapy for cancer and 20 of those with aids also develop the disease about three quarters of women have at least one yeast infection at some time during their lives widespread disease is rare except in those who have risk factors
candidid is a skin condition an id reaction similar to dermatophytids
in radiology canga s bead symptom is the irregular appearance of uterus and nodular structures in tuba uterina observed in patients with genital tuberculosis it is named for serif canga 1906 1993 a turkish gynecologist in 1971
canine epileptoid cramping syndrome cecs also known as spike s disease also known as border terrier s disease is a hereditary canine disease with similarities to canine epilepsy and is often associated with border terriers cecs is a recently recognized problem which is theorised as being a metabolic neurological or muscle disorder but the cause has not yet been identified in 2015 a study came to the conclusion that canine epileptoid cramping syndrome in border terrier s is a gluten sensitive movement disorder triggered and perpetuated by gluten and thus responsive to a gluten free diet
canine cognitive dysfunction ccd is a disease prevalent in dogs that exhibit symptoms of dementia or alzheimer s disease shown in humans ccd creates pathological changes in the brain that slow the mental functioning of dogs resulting in loss of memory motor function and learned behaviors from training early in life in the dog ’ s brain a protein by the name of beta amyloid accumulates creating protein deposits called plaques as the dog ages nerve cells die and cerebrospinal fluid fills the empty space left by the dead nerve cells canine cognitive dysfunction takes effect in older dogs mostly after 10 years of age although there is no known cause of ccd genetic factors have been shown to contribute to the occurrence of this disease
canine degenerative myelopathy also known as chronic degenerative radiculomyelopathy is an incurable progressive disease of the canine spinal cord that is similar in many ways to amyotrophic lateral sclerosis als onset is typically after the age of 7 years and it is seen most frequently in the german shepherd dog pembroke welsh corgi and boxer dog though the disorder is strongly associated with a gene mutation in sod 1 that has been found in 43 breeds as of 2008 including the wire fox terrier chesapeake bay retriever rhodesian ridgeback and cardigan welsh corgi progressive weakness and incoordination of the rear limbs are often the first signs seen in affected dogs with progression over time to complete paralysis myelin is an insulating sheath around neurons in the spinal cord one proposed cause of degenerative myelopathy is that the immune system attacks this sheath breaking it down this results in a loss of communication between nerves in lower body of the animal and the brain
discoid lupus erythematosus dle is an uncommon autoimmune disease of the basal cell layer of the skin it occurs in humans and cats more frequently occurring in dogs it does not progress to systemic lupus erythematosus sle in dogs sle can also have skin symptoms but it appears that the two are either separate diseases or dle is a mild form of sle dle in dogs differs from sle in humans in that plasma cells predominate histologically instead of t lymphocytes because worsening of symptoms occurs with increased ultraviolet light exposure sun exposure most likely plays a role in dle although certain breeds see below are predisposed after pemphigus foliaceus dle is the second most common autoimmune skin disease in dogs
canine distemper sometimes termed hardpad disease in canine is a viral disease that affects a wide variety of animal families including domestic and wild species of dogs coyotes foxes pandas wolves ferrets skunks raccoons and large cats as well as pinnipeds some primates and a variety of other species it was long believed that animals in the family felidae including many species of large cat as well as domestic cats were resistant to canine distemper until some researchers reported the prevalence of cdv infection in large felids it is now known that both large felidae and domestic cats can be infected usually through close housing with dogs or possibly blood transfusion from infected cats but such infections appear to be self limiting and largely without symptoms in canines distemper impacts several body systems including the gastrointestinal and respiratory tracts and the spinal cord and brain with common symptoms that include high fever eye inflammation and eye nose discharge labored breathing and coughing vomiting and diarrhea loss of appetite and lethargy and hardening of nose and footpads the viral infection can be accompanied by secondary bacterial infections and can present eventual serious neurological symptoms canine distemper is caused by a single stranded rna virus of the family paramyxoviridae the same family of the viruses that causes measles mumps and bronchiolitis in humans the disease is highly contagious via inhalation and fatal 50 of the time despite extensive vaccination in many regions it remains a major disease of dogs and is the leading cause of infectious disease death in dogs
follicular dysplasia is a genetic disease of dogs causing alopecia or hair loss it is caused by hair follicles that are misfunctioning due to structural abnormality there are several types some affecting only certain breeds diagnosis is achieved through a biopsy and treatment is rarely successful certain breeds such as the mexican hairless dog and chinese crested dog are bred specifically for alopecia
canine leishmaniasis leesh ma nigh ah sis is a zoonotic disease see human leishmaniasis caused by leishmania parasites transmitted by the bite of an infected phlebotomine sandfly canine leishmaniasis was first identified in europe in 1903 and in 1940 40 of all dogs in rome were determined to be positive for leishmaniasis traditionally thought of as a disease only found near the mediterranean basin 2008 research claims new findings are evidence that canine leishmaniasis is currently expanding in continental climate areas of northwestern italy far from the recognized disease endemic areas along the mediterranean coasts cases of leishmaniasis began appearing in north america in 2000 and as of 2008 leishmania positive foxhounds have been reported in 22 u s states and two canadian provinces
canine pancreatitis is inflammation of the pancreas that can occur in two very different forms acute pancreatitis is sudden while chronic pancreatitis is characterized by recurring or persistent form of pancreatic inflammation cases of both can be considered mild or severe
canine transmissible venereal tumors ctvts also called transmissible venereal tumors tvts canine transmissible venereal sarcoma ctvs sticker tumors and infectious sarcoma is a histiocytic tumor of the external genitalia of the dog and other canines and is transmitted from animal to animal during mating it is one of only four known transmissible cancers another is devil facial tumor disease a cancer which occurs in tasmanian devils the tumor cells are themselves the infectious agents and the tumors that form are not genetically related to the host dog although the genome of a ctvt is derived from a canid probably a dog wolf or coyote it is now essentially living as a unicellular asexually reproducing but sexually transmitted pathogen sequence analysis of the genome suggests it diverged from canids over 6 000 years ago possibly much earlier the most recent estimates of its time of origin place date it to about 11 000 years ago however the most recent common ancestor of extant tumors is more recent it probably originated 200 to 2 500 years ago canine tvts were initially described by russian veterinarian m a novinsky 1841 – 1914 in 1876 when he demonstrated that the tumor could be transplanted from one dog to another by infecting them with tumor cells
canna rust is a fungal disease of canna caused by puccinia thaliae symptoms include yellow to tan spots on the plant s leaves and stems yellow spore producing structures called pustules are produced on the lower abaxial leaf surface and these are the signs of the disease spots on the upper leaf surface coalesce and turn to brown to black as the disease progresses the infected leaves eventually become dry and prematurely fall
cannabinoid hyperemesis syndrome is characterized by recurrent nausea vomiting and crampy abdominal pain these symptoms have been reported to be improved temporarily by taking a hot shower or bath or more fully by stopping the use of cannabis the syndrome was described by allen and colleagues 2004 and sontineni and colleagues 2009 who offer simplified clinical diagnostic criteria a subsequent larger study reported a case series of 98 subjects with cannabinoid hyperemesis syndrome confirming the earlier reported findings
cannabis use disorder or cannabis dependence is defined in the fifth revision of the diagnostic and statistical manual of mental disorders dsm 5 as the continued use of cannabis despite clinically significant impairment ranging from mild to severe cannabis is one of the most widely used drugs in the world in the united states 49 of people have used cannabis although physical addiction has not been proven an estimated 9 of those who use cannabis develop dependence in the us as of 2013 cannabis is the most commonly identified illicit substance used by people admitted to treatment facilities demand for treatment for cannabis use disorder increased internationally between 1995 and 2002
the cannizzaro reaction named after its discoverer stanislao cannizzaro is a chemical reaction that involves the base induced disproportionation of an aldehyde lacking a hydrogen atom in the alpha position file cannizzaro reaction benzaldehyde svg cannizzaro first accomplished this transformation in 1853 when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash potassium carbonate more typically the reaction would be conducted with sodium or potassium hydroxide 2 c 6 h 5 cho koh → c 6 h 5 ch 2 oh c 6 h 5 cook the oxidation product is a salt of a carboxylic acid and the reduction product is an alcohol
a canonical model is a design pattern used to communicate between different data formats a form of enterprise application integration it is intended to reduce costs and standardize on agreed data definitions associated with integrating business systems a canonical model is any model that is canonical in nature i e a model which is in the simplest form possible based on a standard application integration eai solution most organizations also adopt a set of standards for message structure and content message payload the desire for consistent message payload results in the construction of an enterprise or business domain canonical model common view within a given context often the term canonical model is used interchangeably with integration strategy and often entails a move to a message based integration methodology a typical migration from point to point canonical data model an enterprise design pattern which provides common data naming definition and values within a generalized data framework adoption of a comprehensive enterprise interfacing to message based integration begins with a decision on the middleware to be used to transport messages between endpoints often this decision results in the adoption of an enterprise service bus esb or enterprise application integration eai solution most organizations also adopt a set of standards for message structure and content message payload the desire for consistent message payload results in the construction of an enterprise form of xml schema built from the common model objects thus providing the desired consistency and re usability while ensuring data integrity
canonical protocol is a design pattern applied within the service orientation design paradigm which attempts to make services within a service inventory interoperable with each other by standardizing the communication protocols used by the services this eliminates the need for bridging communication protocols when services use different communication protocols
in software engineering canonical schema is a design pattern applied within the service orientation design paradigm which aims to reduce the need for performing data model transformation when services exchange messages that reference the same data model
the cant of a railway track or camber of a road also referred to as superelevation cross slope or cross fall is the rate of change in elevation height between the two rails or edges this is normally greater where the railway or road is curved raising the outer rail or the outer edge of the road providing a banked turn thus allowing vehicles to maneuver through the curve at higher speeds than would otherwise be possible if the surface was flat or level
canter time canter timing or canter rhythm is a two beat regular rhythmic pattern of a musical instrument or in dance steps within 3 4 time music the term is borrowed from the canter horse gait which sounds three hoof beats followed by a pause i e 3 accents in 4 4 time in waltz dances it may mark the 1 st and the 4 th eighths of the measure producing a 2 4 time overlay beat over the 3 4 time in other words when a 3 4 measure is cued as 1 2 3 the canter rhythm marks 1 and this rhythm is the basis of the canter waltz in modern ballroom dancing an example is canter pivot in viennese waltz in vals a 3 4 style of tango the canter rhythm is also known as medio galope which actually means canter in spanish and may accent beats 1 and 2 of the 3 4 measure
cantú syndrome is a rare condition characterized by hypertrichosis osteochondrodysplasia and cardiomegaly less than 50 cases have been described in the literature a majority of the cases is associated with a mutation in the abcc 9 gene that codes for the abcc 9 protein
capability management is a high level integrative management function with particular application in the context of defence
capacitance is the ability of a body to store an electrical charge a material with a large capacitance holds more electric charge at a given voltage than one with low capacitance any object that can be electrically charged exhibits capacitance however the concept is particularly important for understanding the operations of the capacitor one of the three fundamental electronic components along with resistors and inductors the si unit of capacitance is the farad symbol f named after the english physicist michael faraday a 1 farad capacitor when charged with 1 coulomb of electrical charge has a potential difference of 1 volt between its plates
the capacitor plague was a problem related to a higher than expected failure rate of non solid aluminum electrolytic capacitors between 1999 and 2007 especially those from some taiwanese manufacturers due to faulty electrolyte composition that caused corrosion accompanied by gas generation often rupturing the case of the capacitor from the build up of pressure high failure rates occurred in many well known brands of electronics and was particularly evident in motherboards video cards and power supplies of personal computers leading to premature failure of these devices
capacity loss or capacity fading is a phenomenon observed in rechargeable battery usage where the amount of charge a battery can deliver at the rated voltage decreases with use in 2003 it was reported the typical range of capacity loss in lithium ion batteries after 500 charging and discharging cycles varied from 12 4 to 24 1 giving an average capacity loss per cycle range of 0 025 – 0 048 per cycle
capacity utilization or capacity utilisation is the extent to which an enterprise or a nation actually uses its installed productive capacity it is the relationship between output that is actually produced with the installed equipment and the potential output which could be produced with it if capacity was fully used
capgras delusion is a disorder in which a person holds a delusion that a friend spouse parent or other close family member or pet has been replaced by an identical looking impostor the capgras delusion is classified as a delusional misidentification syndrome a class of delusional beliefs that involves the misidentification of people places or objects usually not in conjunction it can occur in acute transient or chronic forms cases in which patients hold the belief that time has been warped or substituted have also been reported the delusion most commonly occurs in patients diagnosed with paranoid schizophrenia but has also been seen in patients suffering from brain injury and dementia it presents often in individuals with a neurodegenerative disease particularly at an older age it has also been reported as occurring in association with diabetes hypothyroidism and migraine attacks in one isolated case the capgras delusion was temporarily induced in a healthy subject by the drug ketamine it occurs more frequently in females with a female male ratio of 3 2
capillariasis is a disease caused by nematodes in the capillaria genus the two principal forms of the disease are intestinal capillariasis caused by capillaria philippinensis hepatic capillariasis caused by capillaria hepatica
capillaritis is a non existent term that refers to a state where the capillaries are inflamed it may occur in the lungs as pulmonary capillaritis or in the skin as pigmented purpuric dermatosis on the legs starts out as little brownish dots and can cause achiness mild capillaritis clears up within 3 – 4 months
capillary action sometimes capillarity capillary motion or wicking is the ability of a liquid to flow in narrow spaces without the assistance of or even in opposition to external forces like gravity the effect can be seen in the drawing up of liquids between the hairs of a paint brush in a thin tube in porous materials such as paper and plaster in some non porous materials such as sand and liquefied carbon fiber or in a cell it occurs because of intermolecular forces between the liquid and surrounding solid surfaces if the diameter of the tube is sufficiently small then the combination of surface tension which is caused by cohesion within the liquid and adhesive forces between the liquid and container wall act to propel the liquid
a capillary hemangioma also known as an infantile hemangioma strawberry hemangioma and strawberry nevus is the most common variant of hemangioma which appears as a raised red lumpy area of flesh anywhere on the body though 83 occur on the head or neck area these marks occur in about 10 of all births and usually appear between one and four weeks after birth it may grow rapidly before stopping and slowly fading some are gone by the age of 2 about 60 by 5 years and 90 – 95 by 9 years capillary hemangioma is a vascular anomaly capillary hemangiomas occur 5 times more often in female infants than in males and mostly in caucasian populations additionally low birthweight infants have a 26 chance of developing a hemangioma it is the most common tumor of orbit and periorbital areas in childhood it may occur in the skin subcutaneous tissues and mucous membranes of oral cavities and lips as well as in the liver spleen and kidneys while this birthmark may be alarming in appearance physicians generally counsel that it be left to disappear on its own unless it is in the way of vision or blocking the nostrils
capillary leak syndrome also known as systemic capillary leak syndrome scls or clarkson ’ s disease is an extremely rare medical condition characterized by self reversing episodes during which the endothelial cells which line the capillaries are thought to separate for a few days allowing for a leakage of fluid from the circulatory system to the interstitial space resulting in a dangerous hypotension low blood pressure hemoconcentration and hypoalbuminemia it is a life threatening illness because each episode has the potential to cause damage to or the failure of vital organs due to limited perfusion it is often misdiagnosed as polycythemia polycythemia vera or sepsis
capital appreciation is an increase in the price or value of assets it may refer to appreciation of company stocks or bonds held by an investor an increase in land valuation or other upward revaluation of fixed assets capital appreciation may occur passively and gradually without the investor taking any action it is distinguished from a capital gain which is the profit achieved by selling an asset capital appreciation may or may not be shown in financial statements if it is shown by revaluation of the asset the increase is said to be recognized once the asset is sold the appreciation since the date of initially buying the asset becomes a realized gain when the term is used in reference to stock valuation capital appreciation is the goal of an investor seeking long term growth it is growth in the principal amount invested but not necessarily an increase in the current income from the asset in the context of investment in a mutual fund capital appreciation refers to a rise in the value of the securities in a portfolio which contributes to the growth in net asset value a capital appreciation fund is a fund for which it is its primary goal and accordingly invests in growth stocks
capital intensity is the amount of fixed or real capital present in relation to other factors of production especially labor at the level of either a production process or the aggregate economy it may be estimated by the capital to labor ratio such as from the points along a capital labor isoquant
capital loss is the difference between a lower selling price and a higher purchase price resulting in a financial loss for the seller
capital requirement also known as regulatory capital or capital adequacy is the amount of capital a bank or other financial institution has to hold as required by its financial regulator this is usually expressed as a capital adequacy ratio of equity that must be held as a percentage of risk weighted assets these requirements are put into place to ensure that these institutions do not take on excess leverage and become insolvent capital requirements govern the ratio of equity to debt recorded on the liabilities and equity side of a firm s balance sheet they should not be confused with reserve requirements which govern the assets side of a bank s balance sheet — in particular the proportion of its assets it must hold in cash or highly liquid assets
caplan s syndrome or caplan disease or rheumatoid pneumoconiosis is a combination of rheumatoid arthritis ra and pneumoconiosis that manifests as intrapulmonary nodules which appear homogenous and well defined on chest x ray
caprine arthritis encephalitis cae is a lentiviral infection of goats which may lead to chronic disease of the joints and on rare occasions encephalitis the symptoms of this disease are varied mature goats can develop arthritis and find walking painful the knee joints may be inflamed and swollen and the goats will slowly lose condition in some cases they will not be able to stand as of 2012 there is no known cure goats which test positive for the disease are typically separated from the rest of the herd
caprivi sometimes called the caprivi strip in german caprivizipfel caprivi panhandle okavango strip or okavango panhandle and formerly known as itenge is a narrow protrusion of namibia eastwards from the kavango region about 450 km 280 mi between botswana to the south and angola and zambia to the north caprivi is bordered by the okavango kwando chobe and zambezi rivers its largest settlement is the town of katima mulilo it went through a civil war from 1994 – 1999 the strip is administratively divided between the eastern zambezi region and the western kavango east region
in anatomy capsulitis is inflammation of a capsule types include adhesive capsulitis of shoulder plica syndrome which is an inflammation of the articular capsule of the knee joint
in telecommunications the capture effect or fm capture effect is a phenomenon associated with fm reception in which only the stronger of two signals at or near the same frequency or channel will be demodulated the capture effect is defined as the complete suppression of the weaker signal at the receiver limiter if it has one where the weaker signal is not amplified but attenuated when both signals are nearly equal in strength or are fading independently the receiver may switch from one to the other and exhibit picket fencing the capture effect can occur at the signal limiter or in the demodulation stage for circuits that do not require a signal limiter some types of radio receiver circuits have a stronger capture effect than others the measurement of how well a receiver can reject a second signal on the same frequency is called the capture ratio for a specific receiver it is measured as the lowest ratio of the power of two signals that will result in the suppression of the smaller signal amplitude modulation or am radio transmission is not subject to this effect this is one reason that the aviation industry and others have chosen to use am for communications rather than fm allowing multiple signals to be broadcast on the same channel phenomena similar to the capture effect are described in am when offset carriers of different strengths are present in the passband of a receiver for example the aviation glideslope vertical guidance clearance beam is sometimes described as a capture effect system even though it operates using am signals
caput medusae also known as palm tree sign is the appearance of distended and engorged superficial epigastric veins which are seen radiating from the umbilicus across the abdomen the name caput medusae latin for head of medusa originates from the apparent similarity to medusa s head which had venomous snakes in place of hair it is also a syndrome of portal hypertension it is caused by the paraumbilical veins which carries oxygenated blood from mother to fetus in utero and normally closes within one week of birth becoming re canalised due to portal hypertension caused by liver failure
caput succedaneum is a neonatal condition involving a serosanguinous subcutaneous extraperiosteal fluid collection with poorly defined margins caused by the pressure of the presenting part of the scalp against the dilating cervix tourniquet effect of the cervix during delivery it involves bleeding below the scalp and above the periosteum
carbamoyl phosphate synthetase i deficiency cps i deficiency is an autosomal recessive metabolic disorder that causes ammonia to accumulate in the blood due to a lack of the enzyme carbamoyl phosphate synthetase i ammonia which is formed when proteins are broken down in the body is toxic if the levels become too high the nervous system is especially sensitive to the effects of excess ammonia
carbene dimerization is a type of organic reaction in which two carbene or carbenoid precursors react in a formal dimerization to an alkene this reaction is often considered an unwanted side reaction but it is also investigated as a synthetic tool in this reaction type either the two carbenic intermediates react or a carbenic intermediate reacts with a carbene precursor an early pioneer was christoph grundmann reporting on a carbene dimerisation in 1938 in the domain of persistent carbenes the wanzlick equilibrium describes an equilibrium between a carbene and its alkene a reoccurring substrate is a diazo compound and more specifically an alpha carbonyl diazo compound for example ethyl diazoacetate is converted to diethyl maleate using the ruthenium catalyst chloro cyclopentadienyl bis triphenylphosphine ruthenium carbene dimerization baratta 1997 grubbs catalyst is also effective in this reaction type the active intermediate is a transition metal carbene complex a diazo cross coupling reaction has also been reported between ethyl diazoacetate and methyl phenyldiazoacetate using the rhodium catalyst rh 2 opiv 4 a direct metal carbene dimerization has been used in the synthesis of novel polyalkynylethenes
in carbohydrate chemistry carbohydrate acetalisation is an organic reaction and a very effective means of providing a protecting group the example below depicts the acetalisation reaction of d ribose 1 with acetone or 2 2 dimethoxypropane as the acetalisation reagent the reaction is under thermodynamic reaction control and results in the pentose 2 the latter reagent in itself is an acetal and therefore the reaction is actually a cross acetalisation file carbohydrateacetalisation png kinetic reaction control results from 2 methoxypropene as the reagent d ribose in itself is a hemiacetal and in equilibrium with the pyranose 3 in aqueous solution ribose is 75 pyranose and 25 furanose and a different acetal 4 is formed
carbometalation is an organometallic reaction involving the nucleophilic addition to alkenes and alkynes of a diverse range of organometallic reagents such as organolithium compounds organocopper compounds and grignard reagents according to the following general alkyne scheme carbometalation the addition can yield the cis or trans isomer and with unsymmetrical alkynes the organometallic compound can add in two different way thus control of regioselectivity is important in a follow up step the sensitive metalalkenyl group is replaced by an electrophile e
carbon leakage occurs when there is an increase in carbon dioxide emissions in one country as a result of an emissions reduction by a second country with a strict climate policy carbon leakage may occur for a number of reasons if the emissions policy of a country raises local costs then another country with a more relaxed policy may have a trading advantage if demand for these goods remains the same production may move offshore to the cheaper country with lower standards and global emissions will not be reduced if environmental policies in one country add a premium to certain fuels or commodities then the demand may decline and their price may fall countries that do not place a premium on those items may then take up the demand and use the same supply negating any benefit there is no consensus over the magnitude of long term leakage effects this is important for the problem of climate change carbon leakage is one type of spill over effect spill over effects can be positive or negative for example emission reductions policy might lead to technological developments that aid reductions outside of the policy area carbon leakage is defined as the increase in co 2 emissions outside the countries taking domestic mitigation action divided by the reduction in the emissions of these countries it is expressed as a percentage and can be greater or less than 100 carbon leakage may occur through changes in trading patterns and that is sometimes measured as the balance of emissions embodied in trade beet
carbon monoxide poisoning occurs after too much inhalation of carbon monoxide co carbon monoxide is a toxic gas but being colorless odorless tasteless and initially non irritating it is very difficult for people to detect carbon monoxide is a product of incomplete combustion of organic matter due to insufficient oxygen supply to enable complete oxidation to carbon dioxide co 2 it is often produced in domestic or industrial settings by motor vehicles that run on gasoline diesel methane or other carbon based fuels and from tools gas heaters and cooking equipment that are powered by carbon based fuels such as propane butane and charcoal exposure at 100 ppm or greater can be dangerous to human health symptoms of mild acute poisoning include lightheadedness confusion headache vertigo and flu like effects larger exposures can lead to significant toxicity of the central nervous system and heart and death after acute poisoning long term sequelae often occur carbon monoxide can also have severe effects on the fetus of a pregnant woman chronic exposure to low levels of carbon monoxide can lead to depression confusion and memory loss carbon monoxide mainly causes adverse effects in humans by combining with hemoglobin to form carboxyhemoglobin hbco in the blood this prevents hemoglobin from carrying oxygen to the tissues effectively reducing the oxygen carrying capacity of the blood leading to hypoxia additionally myoglobin and mitochondrial cytochrome oxidase are thought to be adversely affected carboxyhemoglobin can revert to hemoglobin but the recovery takes time because the hbco complex is fairly stable treatment of poisoning largely consists of administering 100 oxygen or providing hyperbaric oxygen therapy although the optimum treatment remains controversial oxygen works as an antidote as it increases the removal of carbon monoxide from hemoglobin in turn providing the body with normal levels of oxygen the prevention of poisoning is a significant public health issue domestic carbon monoxide poisoning can be prevented by early detection with the use of household carbon monoxide detectors carbon monoxide poisoning is the most common type of fatal poisoning in many countries historically it was also commonly used as a method to commit suicide usually by deliberately inhaling the exhaust fumes of a running car engine modern automobiles even with electronically controlled combustion and catalytic converters can still produce levels of carbon monoxide which will kill if enclosed within a garage or if the tailpipe is obstructed for example by snow and exhaust gas cannot escape normally carbon monoxide poisoning has also been speculated as a possible cause of apparent haunted houses symptoms such as delirium and hallucinations may have led people suffering poisoning to think they have seen ghosts or to believe their house is haunted
carbon stains are a skin condition characterized by a discoloration of the skin from embedded carbon usually occurring in children from accidents with firearms or firecrackers or from a puncture wound by a pencil which may leave a permanent black mark of embedded graphite easily mistaken for metastatic melanoma
carbonatation is a chemical reaction in which calcium hydroxide reacts with carbon dioxide and forms insoluble calcium carbonate ca oh 2 co 2 → caco 3 h 2 o the process of forming a carbonate is sometimes referred to as carbonation although this term usually refers to the process of dissolving carbon dioxide in water
carbon – hydrogen bond functionalization c – h functionalization is a type of reaction in which a carbon – hydrogen bond is cleaved and replaced with a carbon x bond where x is usually carbon oxygen or nitrogen the term usually implies that a transition metal is involved in the c h cleavage process reactions classified by the term typically involve the hydrocarbon first to react with a metal catalyst to create an organometallic complex in which the hydrocarbon is coordinated to the inner sphere of a metal either via an intermediate alkane or arene complex or as a transition state leading to a m − c intermediate the intermediate of this first step known as c h activation and sometimes used interchangeably with c h functionalization can then undergo subsequent reactions to produce the functionalized product important to this definition is the requirement that during the c – h cleavage event the hydrocarbyl species remains associated in the inner sphere and under the influence of m while many mechanisms for a variety of c h activations are still unknown many of them fall under three general categories i oxidative addition in which a metal center inserts into a carbon hydrogen bond which cleaves the bond and oxidizes the metal producing an intermediate that can undergo reductive elimination to yield the organometallic reactive intermediate ii electrophilic activation which reacts similarly to oxidative addition but differs in that it produces the organometallic reactive intermediate through an oxidative transition state instead of an intermediate and iii σ bond metathesis which proceeds through a four centered transition state in which bonds break and form in concerted fashion the target hydrocarbon bond breaks as the carbon bonds to the metal and the hydrogen bonds to one of the metal ’ s ligands which causes bond breakage between the ligand and the metal c – h bonds which are traditionally considered unreactive can be cleaved by coordination much research has been devoted to the design and synthesis of new reagents and catalysts that can effect c – h activation c h activation chemistry has the potential to transform the chemical world through the development of novel synthetic methods c h activation could enable the conversion of cheap and abundant alkanes into valuable functionalized organic compounds and the efficient structural editing of already complex molecules i e natural product synthesis selective activation of a specific c h bond poses a great challenge in addition to a high bond dissociation energy c h bonds have very low polarity because to these two elements have similar electronegativities
carboxylation in chemistry is a chemical reaction in which a carboxylic acid group is introduced in a substrate the opposite reaction is decarboxylation
a carbuncle is a cluster of boils draining pus onto the skin it is usually caused by bacterial infection most commonly with staphylococcus aureus or streptococcus pyogenes which can turn lethal however the presence of a carbuncle is actually a sign that the immune system is active and fighting the infection responsible for the carbuncle the infection is contagious and may spread to other areas of the body or other people those living in the same residence may develop carbuncles at the same time
carburetor icing or carb icing is an icing condition which can affect any carburetor under certain atmospheric conditions the problem is most notable in certain realms of aviation carburetor icing occurs when there is humid air and the temperature drop in the venturi causes the water vapor to freeze the venturi effect can drop the ambient air temperature by 30 40 degrees f therefore carburetor icing often occurs when the outside air temperature is in the 60 70 degree f range unfortunately the warm air temperature often causes pilots to overlook the possibility of carb icing the ice will form on the surfaces of the carburetor throat further restricting it this may increase the venturi effect initially but eventually restricts airflow perhaps even causing a complete blockage of air to the carburetor the engine begins to run more rich as ice formation increases without intervention carb heat or leaning this can only continue until the mixture is outside of the chemically correct range for combustion icing may also cause jamming of the mechanical parts of the carburetor such as the throttle typically a butterfly valve while it applies to all carburetors carburetor icing is of particular concern in association with piston powered aircraft especially small single engine light aircraft aircraft powered by carbureted engines are equipped with carburetor heat systems to overcome the icing problem in cars carburetor icing can occasionally be a nuisance the inlet manifold and parts of the carburetor often have warm water from the cooling system or exhaust gas circulating through them to combat this problem motorcycles can also suffer from carburetor icing although some engine designs are more susceptible to it than others air cooled engines may be more prone to icing due to the absence of warm coolant circulating through the engine
carcinoid also carcinoid tumor is a slow growing type of neuroendocrine tumor originating in the cells of the neuroendocrine system in some cases metastasis may occur carcinoid tumors of the midgut jejunum ileum appendix and cecum are associated with carcinoid syndrome
carcinoid syndrome is a paraneoplastic syndrome comprising the signs and symptoms that occur secondary to carcinoid tumors the syndrome includes flushing and diarrhea and less frequently heart failure and bronchoconstriction it is caused by endogenous secretion of mainly serotonin and kallikrein
carcinoma is a type of cancer that develops from epithelial cells specifically a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body and that generally arises from cells originating in the endodermal or ectodermal germ layer during embryogenesis carcinomas occur when the dna of a cell is damaged or altered and the cell begins to grow uncontrollably and become malignant it is from the greek καρκίνωμα karkinoma meaning sore ulcer or cancer itself derived from karkinos crab
carcinoma ex pleomorphic adenoma abbreviated ca ex pa is a type of cancer typically found in the parotid gland it arises from the benign tumour pleomorphic adenoma its prognosis depends on the stage early tumour have essentially a benign behaviour
carcinoma in situ cis also known as in situ neoplasm is a group of abnormal cells while they are a form of neoplasm there is disagreement over whether cis should be classified as cancer this controversy also depends on the exact cis in question i e cervical skin breast some authors do not classify them as cancer however recognizing that they can potentially become cancer others classify certain types as a non invasive form of cancer the term pre cancer has also been used these abnormal cells grow in their normal place thus in situ from latin for in its place for example carcinoma in situ of the skin also called bowen s disease is the accumulation of dysplastic epidermal cells within the epidermis only that has failed to penetrate into the deeper dermis for this reason cis will usually not form a tumor rather the lesion is flat in the skin cervix etc or follows the existing architecture of the organ in the breast lung etc exceptions include cis of the colon polyps the bladder preinvasive papillary cancer or the breast ductal carcinoma in situ or lobular carcinoma in situ many forms of cis have a high probability of progression into cancer and therefore removal may be recommended however progression of cis is known to be highly variable and not all cis becomes invasive cancer in the tnm classification carcinoma in situ is reported as tisn 0 m 0 stage 0
carcinosarcomas are malignant tumors that consist of a mixture of carcinoma or epithelial cancer and sarcoma or mesenchymal connective tissue cancer carcinosarcomas are rare tumors and can arise in diverse organs such as the skin salivary glands lungs the esophagus pancreas colon uterus and ovaries four main hypotheses have been proposed for the cellular origins of carcinosarcoma based largely on the pathology of the disease first the collision tumor hypothesis which proposes the collision of two independent tumors resulting in a single neoplasm based on the observation that skin cancers and superficial malignant fibrous histiocytomas are commonly seen in patients with sun damaged skin second the composition hypothesis which suggests that the mesenchymal component represents a pseudosarcomatous reaction to the epithelial malignancy third the combination hypothesis which suggests that both the epithelial and mesenchymal components of the tumor arise from a common pluripotential stem cell that undergoes divergent differentiation and fourth the conversion divergence hypothesis which argues that the sarcomatous component of the tumor represents a metaplastic sarcomatous transformation of the epithelial component despite the remaining uncertainty on the mechanisms that generate these tumors recent immunohistochemical ultrastructural and molecular genetic studies suggest and favor the notion of monoclonality in carcinosarcoma in addition identical p 53 and kras mutations have been identified in both epithelial and mesenchymal components of carcinosarcoma findings that suggest an early alteration in the histogenesis of the tumor with late transformation or degeneration of the epithelial component into the sarcomatous component
carcinosis or carcinomatosis is disseminated cancer forms of metastasis whether used generally or in specific patterns of spread
cardiac arrest is a sudden stop in effective blood flow due to the failure of the heart to contract effectively symptoms include loss of consciousness and abnormal or absent breathing some people may have chest pain shortness of breath or nausea before this occurs if not treated within minutes death usually occurs the most common cause of cardiac arrest is coronary artery disease less common causes include major blood loss lack of oxygen very low potassium heart failure and intense physical exercise a number of inherited disorders may also increase the risk including long qt syndrome the initial heart rhythm is most often ventricular fibrillation the diagnosis is confirmed by finding no pulse while a cardiac arrest may be caused by heart attack or heart failure these are not the same prevention includes not smoking physical activity and maintaining a healthy weight treatment for cardiac arrest is immediate cardiopulmonary resuscitation cpr and if a shockable rhythm is present defibrillation among those who survive targeted temperature management may improve outcomes an implantable cardiac defibrillator may be placed to reduce the chance of death from recurrence in the united states cardiac arrest outside of hospital occurs in about 13 per 10 000 people per year 326 000 cases in hospital cardiac arrest occurs in an additional 209 000 cardiac arrest becomes more common with age it affects males more often than females the percentage of people that survive with treatment is about 8 many who survive have significant disability
cardiac arrhythmia also known as cardiac dysrhythmia or irregular heartbeat is a group of conditions in which the heartbeat is irregular too fast or too slow a heart rate that is too fast – above 100 beats per minute in adults – is called tachycardia and a heart rate that is too slow – below 60 beats per minute – is called bradycardia many types of arrhythmia have no symptoms when symptoms are present these may include palpitations or feeling a pause between heartbeats more seriously there may be lightheadedness passing out shortness of breath or chest pain while most types of arrhythmia are not serious some predispose a person to complications such as stroke or heart failure others may result in cardiac arrest there are four main types of arrhythmia extra beats supraventricular tachycardias ventricular arrhythmias and bradyarrhythmias extra beats include premature atrial contractions and premature ventricular contractions supraventricular tachycardias include atrial fibrillation atrial flutter and paroxysmal supraventricular tachycardia ventricular arrhythmias include ventricular fibrillation and ventricular tachycardia arrhythmias are due to problems with the electrical conduction system of the heart arrhythmias may occur in children however the normal range for the heart rate is different and depends on age a number of tests can help with diagnosis including an electrocardiogram ecg and holter monitor most arrhythmias can be effectively treated treatments may include medications medical procedures such as a pacemaker and surgery medications for a fast heart rate may include beta blockers or agents that attempt to restore a normal heart rhythm such as procainamide this later group may have more significant side effects especially if taken for a long period of time pacemakers are often used for slow heart rates those with an irregular heartbeat are often treated with blood thinners to reduce the risk of complications those who have severe symptoms from an arrhythmia may receive urgent treatment with a jolt of electricity in the form of cardioversion or defibrillation arrhythmia affects millions of people in europe and north america as of 2014 atrial fibrillation affects about 2 to 3 of the population atrial fibrillation and atrial flutter resulted in 112 000 deaths in 2013 up from 29 000 in 1990 sudden cardiac death is the cause of about half of deaths due to cardiovascular disease or about 15 of all deaths globally about 80 of sudden cardiac death is the result of ventricular arrhythmias arrhythmias may occur at any age but are more common among older people
cardiac asthma is a medical diagnosis of wheezing coughing or shortness of breath due to congestive heart failure it is known as cardiac asthma because the symptoms mimic ordinary asthma one study found that patients with cardiac asthma represented one third of congestive heart failure in elderly patients depending on severity it may be classified as a medical emergency as it can be a symptom of acute heart failure leading to the buildup of fluids in the lungs pulmonary edema as well as within and around the airways the distinction between true asthma and cardiac asthma is especially important because some treatments for true asthma including inhalers may actually worsen cardiac asthma and cause severe heart arrhythmias true asthma in contrast is caused by the inflammation and eventual narrowing down of airways this is what causes the breathing difficulties that are characteristic to asthma true asthma has nothing to do with fluid in the lungs or heart disease or even the heart failure which is so associated with cardiac asthma
a cardiac fibroma is a rare benign tumor of the heart that occurs primarily in children it is most commonly located in the interventricular septum or left ventricular wall symptoms depend on the size of the tumor its location relative to the conduction system and whether it obstructs blood flow symptomatic cardiac fibromas may be treated by surgical resection it is associated with gorlin syndrome
an atrial myxoma is a benign tumor of the heart most commonly found within the left and then the right atria on the interatrial septum
a cardiac shunt is a pattern of blood flow in the heart that deviates from the normal circuit of the circulatory system it may be described as right left left right or bidirectional or as systemic to pulmonary or pulmonary to systemic the direction may be controlled by left and or right heart pressure a biological or artificial heart valve or both the presence of a shunt may also affect left and or right heart pressure either beneficially or detrimentally
cardiac tamponade also known as pericardial tamponade is when fluid in the pericardium the sac around the heart builds up and results in compression of the heart onset may be rapid or more gradual symptoms typically include those of cardiogenic shock including shortness of breath weakness lightheadedness and cough other symptoms may relate to the underlying cause common causes include cancer kidney failure chest trauma and pericarditis other causes include connective tissue diseases hypothyroidism aortic rupture and following cardiac surgery in africa tuberculosis is a relatively common cause diagnosis may be suspected based on low blood pressure jugular venous distension pericardial rub or quiet heart sounds the diagnosis may be further supported by specific electrocardiogram ecg changes chest x ray or an ultrasound of the heart if fluid increases slowly the pericardial sac can expand to contain more than 2 liters however if the increase is rapid as little as 200 ml can result in tamponade when tamponade results in symptoms drainage is necessary this can be done by pericardiocentesis surgery to create a pericardial window or a pericardiectomy drainage may also be necessary to rule out infection or cancer other treatments may include the use of dobutamine or in those with low blood volume intravenous fluids those with few symptoms and no worrisome features can often be closely followed the frequency of tamponade is unclear one estimate from the united states places it at 2 per 10 000 per year
in mathematics a cardinal function or cardinal invariant is a function that returns cardinal numbers
in pathology a cardinal sign or cardinal symptom is the primary or major clinical sign symptom by which a diagnosis is made a cluster of signs or symptoms are often combined pathognomonic to better diagnose a specific disease or syndrome
cardiofaciocutaneous syndrome cfc is an extremely rare and serious genetic disorder it is characterized by the following distinctive facial appearance unusually sparse brittle curly scalp hair a range of skin abnormalities from dermatitis to thick scaly skin over the entire body generalized ichthyosis heart malformations congenital or appearing later especially an obstruction of the normal flow of blood from the lower right ventricle of the heart to the lungs valvar pulmonary stenosis delayed growth foot abnormalities extra toe or fusion of two or more toes
cardiogenic shock is a life threatening medical condition resulting from an inadequate circulation of blood due to primary failure of the ventricles of the heart to function effectively as this is a type of circulatory shock there is insufficient perfusion of tissue to meet the demands for oxygen and nutrients cardiogenic shock is a largely irreversible condition and as such is more often fatal than not the condition involves increasingly more pervasive cell death from oxygen starvation hypoxia and nutrient starvation e g low blood sugar because of this it may lead to cardiac arrest or circulatory arrest which is an abrupt stopping of cardiac pump function as well as stopped respiration and a loss of consciousness cardiogenic shock is defined by sustained low blood pressure with tissue hypoperfusion despite adequate left ventricular filling pressure signs of tissue hypoperfusion include low urine production 30 ml hour cool extremities and altered level of consciousness treatment of cardiogenic shock depends on the cause if cardiogenic shock is due to a heart attack attempts to open the heart s arteries may help an intra aortic balloon pump or left ventricular assist device may improve matters until this can be done medications that improve the heart s ability to contract positive inotropes may help however it is unclear which is best norepinephrine may be better if the blood pressure is very low whereas dopamine or dobutamine may be more useful if only slightly low
cardiomegaly is a medical condition in which the heart is enlarged it is more commonly referred to as an enlarged heart the causes of cardiomegaly may vary many times this condition results from high blood pressure hypertension or coronary artery disease an enlarged heart may not pump blood effectively resulting in congestive heart failure cardiomegaly may improve over time but many people with an enlarged heart need lifelong treatment with medications having an immediate family member who has or had cardiomegaly may indicate that a person is more susceptible to getting this condition cardiomegaly is not a disease but rather a condition that can result from a host of other diseases such as obesity or coronary artery disease recent studies suggest that cardiomegaly is associated with a higher risk of sudden cardiac death scd
cardiomyopathy is a group of diseases that affect the heart muscle early on there may be few or no symptoms others may have shortness of breath feel tired or have swelling of the legs due to heart failure an irregular heart beat may occur as well as fainting those affected are at an increased risk sudden cardiac death types of cardiomyopathy include hypertrophic cardiomyopathy dilated cardiomyopathy restrictive cardiomyopathy arrhythmogenic right ventricular dysplasia and broken heart syndrome in hypertrophic cardiomyopathy the heart muscle enlarges and thickens in dilated cardiomyopathy the ventricles enlarge and weaken in restrictive cardiomyopathy the ventricle stiffens the cause is frequently unknown hypertrophic cardiomyopathy is often and dilated cardiomyopathy in a third of cases is inherited from a person s parents dilated cardiomyopathy may also result from alcohol heavy metals coronary heart disease cocaine use and viral infections restrictive cardiomyopathy may be caused by amyloidosis hemochromatosis and some cancer treatments broken heart syndrome is caused by extreme emotional or physical stress treatment depends on the type of cardiomyopathy and the degree of symptoms treatments may include lifestyle changes medications or surgery in 2013 cardiomyopathy and myocarditis affected 7 9 million people hypertrophic cardiomyopathy affects about 1 in 500 people while dilated cardiomyopathy affects 1 in 2 500 they resulted in 443 000 deaths up from 294 000 in 1990 arrhythmogenic right ventricular dysplasia is more common in young people
cardiorenal syndrome crs is an umbrella term used in the medical field that defines disorders of the heart and kidneys whereby “ acute or chronic dysfunction in one organ may induce acute or chronic dysfunction of the other ” the heart and the kidneys are involved in maintaining hemodynamic stability and organ perfusion through an intricate network these two organs communicate with one another through a variety of pathways in an interdependent relationship in a 2004 report from national heart lung and blood institute crs was defined as a condition where treatment of congestive heart failure is limited by decline in kidney function this definition has since been challenged repeatedly but there still remains little consensus over a universally accepted definition for crs at a consensus conference of the acute dialysis quality initiative adqi the crs was classified into five subtypes primarily based upon the organ that initiated the insult as well as the acuity of disease
cardiovascular disease cvd is a class of diseases that involve the heart or blood vessels cardiovascular disease includes coronary artery diseases cad such as angina and myocardial infarction commonly known as a heart attack other cvds are stroke hypertensive heart disease rheumatic heart disease cardiomyopathy heart arrhythmia congenital heart disease valvular heart disease carditis aortic aneurysms peripheral artery disease and venous thrombosis the underlying mechanisms vary depending on the disease in question coronary artery disease stroke and peripheral artery disease involve atherosclerosis this may be caused by high blood pressure smoking diabetes lack of exercise obesity high blood cholesterol poor diet and excessive alcohol consumption among others high blood pressure results in 13 of cvd deaths while tobacco results in 9 diabetes 6 lack of exercise 6 and obesity 5 rheumatic heart disease may follow untreated strep throat it is estimated that 90 of cvd is preventable prevention of atherosclerosis is by decreasing risk factors through healthy eating exercise avoidance of tobacco smoke and limiting alcohol intake treating high blood pressure and diabetes is also beneficial treating people who have strep throat with antibiotics can decrease the risk of rheumatic heart disease the effect of the use of aspirin in people who are otherwise healthy is of unclear benefit the united states preventive services task force recommends against its use for prevention in women less than 55 and men less than 45 years old however in those who are older it is recommends in some individuals treatment of those who have cvd improves outcomes cardiovascular diseases are the leading cause of death globally this is true in all areas of the world except africa together they resulted in 17 3 million deaths 31 5 in 2013 up from 12 3 million 25 8 in 1990 deaths at a given age from cvd are more common and have been increasing in much of the developing world while rates have declined in most of the developed world since the 1970 s coronary artery disease and stroke account for 80 of cvd deaths in males and 75 of cvd deaths in females most cardiovascular disease affects older adults in the united states 11 of people between 20 and 40 have cvd while 37 between 40 and 60 71 of people between 60 and 80 and 85 of people over 80 have cvd the average age of death from coronary artery disease in the developed world is around 80 while it is around 68 in the developing world disease onset is typically seven to ten years earlier in men as compared to women
cardiovascular drift cvd cvdrift is the phenomenon where some cardiovascular responses begin a time dependent change or drift after around 10 minutes of exercise in a warm or neutral environment without an increase in workload it is characterised by decreases in mean arterial pressure and stroke volume and a parallel increase in heart rate it has been shown that a reduction in stroke volume due to dehydration is almost always due to the increase in internal temperature it is influenced by many factors most notably the ambient temperature internal temperature hydration and the amount of muscle tissue activated during exercise to promote cooling blood flow to the skin is increased resulting in a shift in fluids from blood plasma to the skin tissue this results in a decrease in pulmonary arterial pressure and reduced stroke volume in the heart to maintain cardiac output at reduced pressure the heart rate must be increased effects of cardiovascular drift are mainly focused around a higher rpe rate of perceived effort that is a person will feel like they are expending more energy when they are not this creates a mental block that can inhibit performance greatly prevention or minimization of cardiovascular drift includes consistently replacing fluids and maintaining electrolyte imbalance during exercise acclimatization to the environment in which one is performing and weight training to supplement cardiovascular efforts
cardiovascular fitness is the ability of the heart blood cells and lungs to supply oxygen rich blood to the working muscle tissues and the ability of the muscles to use oxygen to produce energy for movement this type of fitness is a health related component of physical fitness that is brought about by sustained physical activity a person ’ s ability to deliver oxygen to the working muscles is affected by many physiological parameters including heart rate stroke volume cardiac output and maximal oxygen consumption understanding the relationship between cardiorespiratory endurance training and other categories of conditioning requires a review of changes that occur with increased aerobic or anaerobic capacity as aerobic anaerobic capacity increases general metabolism rises muscle metabolism is enhanced hemoglobin rises buffers in the bloodstream increase venous return is improved stroke volume is improved and the blood bed becomes more able to adapt readily to varying demands each of these results of cardiovascular fitness cardiorespiratory conditioning will have a direct positive effect on muscular endurance and an indirect effect on strength and flexibility to facilitate optimal delivery of oxygen to the working muscles the person needs to train or participate in activities that will build up the energy stores needed for sport this is referred to as metabolic training metabolic training is generally divided into two types aerobic and anaerobic
carditis is the inflammation of the heart or its surroundings the plural of carditis is carditides it is usually studied and treated by specifying it as pericarditis is the inflammation of the pericardium myocarditis is the inflammation of the heart muscle endocarditis is the inflammation of the endocardium pancarditis is the inflammation of the entire heart the epicardium the myocardium and the endocardium reflux carditis refers to a possible outcome of esophageal reflux also known as gerd and involves inflammation of the esophagus stomach mucosa
caregiver burden is the stress which is perceived by caregivers due to the home care situation this subjective burden is one of the most important predictors for negative outcomes of the care situation – for the caregivers themselves as well as for the one who requires care caregivers are all persons who support and help a person in need of care regularly because of personal – not professional – reasons that means every kind of help and support it doesn ’ t need to be health care in the narrow sense the caregiver doesn ’ t need to be akin with the person they support often friends neighbors or acquaintances provide support too
caregiver syndrome or caregiver stress is a condition of exhaustion anger rage or guilt that results from unrelieved caring for a chronically ill dependent the term is often used by healthcare professionals but it is not listed in the diagnostic and statistical manual of mental disorders almost 66 million americans are providing care to those who are ill aged and or disabled for an average of 39 2 hours per week over 13 million caregivers are also caring for their own children as well caregiver syndrome is acute when caring for an individual with behavioral difficulties such as fecal incontinence memory issues sleep problems wandering dementia and aggression typical symptoms of the caregiver include fatigue insomnia stomach complaints and so on with the most common symptom being depression roughly 70 of caregivers suffer from depression due to the deterioration both physical and mental of these caregivers health professionals have given this condition a name caregiver syndrome or caregiver fatigue
carlin – type gold deposits are sediment hosted disseminated gold deposits these deposits are characterized by invisible typically microscopic and or dissolved gold in pyrite and arsenopyrite this dissolved kind of gold is called invisible gold as it can only be found through chemical analysis the deposit is named after the carlin mine the first large deposit of this type discovered in the carlin trend nevada
carney complex and its subsets lamb syndrome and name syndrome are autosomal dominant conditions comprising myxomas of the heart and skin hyperpigmentation of the skin lentiginosis and endocrine overactivity it is distinct from carney s triad approximately 7 of all cardiac myxomas are associated with carney complex
carnitine acylcarnitine translocase deficiency is a rare autosomal recessive metabolic disorder that prevents the body from converting long chain fatty acids into energy particularly during periods without food carnitine a natural substance acquired mostly through the diet is used by cells to process fats and produce energy people with this disorder have a faulty enzyme that prevents long chain fatty acids from being transported into the innermost part of the mitochondria for processing
carnitine palmitoyltransferase ii deficiency cpt ii is an autosomal recessively inherited genetic metabolic disorder characterized by an enzymatic defect that prevents long chain fatty acids from being transported into the mitochondria for utilization as an energy source the adult myopathic form of this disease was first characterized in 1973 by dimauro and dimauro it is the most common inherited disorder of lipid metabolism affecting the skeletal muscle of adults cpt ii deficiency is also the most frequent cause of hereditary myoglobinuria symptoms of this disease are commonly provoked by prolonged exercise or periods without food
carnitine palmitoyltransferase i deficiency is a rare metabolic disorder that prevents the body from converting certain fats called long chain fatty acids into energy particularly during periods without food carnitine a natural substance acquired mostly through the diet is used by cells to process fats and produce energy people with this disorder have a faulty enzyme carnitine palmitoyltransferase i that prevents these long chain fatty acids from being transported into the mitochondria to be broken down
carnosinemia also called carnosinase deficiency or aminoacyl histidine dipeptidase deficiency is a rare autosomal recessive metabolic disorder caused by a deficiency of carnosinase a dipeptidase a type of enzyme that splits dipeptides into their two amino acid constituents carnosine is a dipeptide composed of beta alanine and histidine and is found in skeletal muscle and cells of the nervous system this disorder results in an excess of carnosine in the urine cerebrospinal fluid csf blood and nervous tissue neurological disorders associated with a deficiency of carnosinase and the resulting carnosinemia carnosine in the blood are common
a carnosity is a medical condition defined by any abnormal fleshy excrescence or tuberosity carnosity comes from the word carnose which means a buildup of flesh the carnosity disease started back in 1884 in middle europe it has led to more than 50 000 deaths worldwide
caroli disease is a rare inherited disorder characterized by dilation of the intrahepatic bile ducts there are two types of caroli disease the most common being the simple or isolated case where the bile ducts are widened by ectasia the second more complex cause is commonly known as caroli syndrome this complex form is also linked with portal hypertension and congenital hepatic fibrosis the differences between the causes of the two cases have not yet been discovered caroli disease is also associated with liver failure and polycystic kidney disease the disease affects about 1 in 1 000 000 people with more reported cases of caroli syndrome than of caroli disease caroli disease also is known as communicating cavernous ectasia or congenital cystic dilatation of the intrahepatic biliary tree caroli disease is distinct from other diseases that cause ductal dilatation caused by obstruction in that it is not one of the many choledochal cyst derivatives
carotenemia or carotenaemia xanthaemia is the presence of the orange pigment carotene in the blood from excessive intake of carrots or other vegetables containing the pigment resulting in increased serum carotenoids carotenoids are lipid soluble compounds that include alpha and beta carotene beta cryptoxanthin lycopene lutein and zeaxanthin the primary serum carotenoids are beta carotene lycopene and lutein serum levels of carotenoids vary between region ethnicity and sex in the healthy population all are absorbed by passive diffusion from the gastrointestinal tract and are then partially metabolized in the intestinal mucosa and liver to vitamin a from there they are transported in the plasma into the peripheral tissues carotenoids are eliminated via sweat sebum urine and gastrointestinal secretions carotenoids contribute to normal appearing human skin color and are a significant component of physiologic ultraviolet photoprotection an excess of carotenoids being eliminated via sweat may cause a marked orange discoloration of the outermost skin layer this benign and reversible condition – which is most easily observed in light skinned people and may be mistaken for jaundice – is known as carotenosis or carotenoderma carotenemia most commonly occurs in vegetarians and young children carotenemia is more easily appreciated in light complexioned people and it may present chiefly as an orange discolouration of the palms and the soles in more darkly pigmented persons carotenemia does not cause selective orange discoloration of the conjunctival membranes over the sclerae whites of the eyes and thus is usually easy to distinguish from the yellowing of the skin and conjunctiva caused by bile pigments in states of jaundice carotenoderma is deliberately caused by beta carotenoid treatment of certain photo sensitive dermatitis diseases such as erythropoietic protoporphyria where beta carotene is prescribed in quantities which discolor the skin these high doses of beta carotene have been found to be harmless in studies though cosmetically displeasing to some in a recent meta analysis of these treatments however the effectiveness of the treatment has been called into question
a carotid cavernous fistula ccf results from an abnormal communication between the arterial and venous systems within the cavernous sinus in the skull it is a type of arteriovenous fistula as arterial blood under high pressure enters the cavernous sinus the normal venous return to the cavernous sinus is impeded and this causes engorgement of the draining veins manifesting most dramatically as a sudden engorgement and redness of the eye of the same side
carotid artery dissection is a separation of the layers of the artery wall supplying oxygen bearing blood to the head and brain and is the most common cause of stroke in young adults in vascular medicine dissection is a blister like de lamination between the outer and inner walls of a blood vessel generally originating with a partial leak in the inner lining
carotid stenosis is a narrowing or constriction of the inner surface lumen of the carotid artery usually caused by atherosclerosis
carotidynia is a syndrome characterized by unilateral one sided tenderness of the carotid artery near the bifurcation it was first described in 1927 by temple fay the most common cause of carotidynia may be migraine and then it is usually self correcting common migraine treatments may help alleviate the carotidynia symptoms recent histological evidence has implicated an inflammatory component of carotidynia but studies are limited carotid arteritis is a much less common cause of carotidynia but has much more serious consequences it is a form of giant cell arteritis which is a condition that usually affects arteries in the head due to this serious condition possibly causing carotidynia and the possibility that neck pain is related to some other non carotidynia and serious condition the case should be investigated by a medical doctor because carotidynia can be caused by numerous causes biousse and bousser in 1994 recommended the term not be used in the medical literature however recent mri and ultrasound studies have supported the existence of a differential diagnosis of carotidynia consistent with fay s characterization
carpal tunnel syndrome cts is a medical condition due to compression of the median nerve as it travels through the wrist at the carpal tunnel the main symptoms are pain numbness and tingling in the thumb index finger middle finger and the thumb side of the ring fingers symptoms typically start gradually and during the night pain may extend up the arm weak grip strength may occur and after a long period of time the muscles at the base of the thumb may waste away in more than half of cases both sides are affected risk factors include obesity repetitive wrist work pregnancy and rheumatoid arthritis there is tentative evidence that hypothyroidism increases the risk it is unclear if diabetes plays a role the use of birth control pills does not affect the risk types of work that are associated include computer work work with vibrating tools and work that requires a strong grip diagnosis is suspected based on signs symptoms and specific physical tests and may be confirmed with electrodiagnostic tests if muscle wasting at the base of the thumb is present the diagnosis is likely being physically active can decrease the risk of developing cts symptoms can be improved by wearing a wrist splint or with corticosteroid injections taking nsaids or gabapentin does not appear to be useful surgery to cut the transverse carpal ligament is effective with better results at a year compared to non surgical options further splinting after surgery is not needed evidence does not support magnet therapy about 5 of people in the united states have carpal tunnel syndrome it usually begins in adulthood and women are more commonly affected than men up to 33 of people may improve without specific treatment over approximately a year carpal tunnel syndrome was first fully described after world war ii
carpellody is a plant disorder that results in misshapen fruits caused by abnormal development of the ovule bearing part of the flower in angiosperms it is commonly called cat face and is specific to papayas some fruits resemble female fruits but the disorder can cause severely deformed fruits with deep longitudinal ridges fruits are generally more rounded and are unmarketable because of their small size and poor eye appeal
the carpenter s rule problem is a discrete geometry problem which can be stated in the following manner can a simple planar polygon be moved continuously to a position where all its vertices are in convex position so that the edge lengths and simplicity are preserved along the way a closely related problem is to show that any polygon can be convexified that is continuously transformed preserving edge distances and avoiding crossings into a convex polygon both problems were successfully solved by
carpenter syndrome also called acrocephalopolysyndactyly type ii is an extremely rare autosomal recessive congenital disorder characterized by craniofacial malformations obesity and syndactyly it was first characterized in 1909
carpometacarpal cmc osteoarthritis oa also known as trapeziometacarpal osteoarthritis or osteoarthritis at the base of the thumb is a reparitive joint disease affecting the first carpometacarpal joint cmc 1 this joint is formed by the trapezium bone of the wrist and the first metacarpal bone of the thumb because of its relative instability this joint is a frequent site for osteoarthritis carpometacarpal osteoarthritis cmc oa of the thumb occurs when the cushioning cartilage of the joint surfaces wears away resulting in damage of the joint the main complaint of patients is pain pain at the base of the thumb occurs when moving the thumb and might eventually persist at rest other symptoms include stiffness swelling and loss of strength of the thumb treatment options include conservative and surgical therapies
oroya fever or carrion s disease is an infectious disease produced by bartonella bacilliformis infection it is named after daniel alcides carrión
the carroll rearrangement is a rearrangement reaction in organic chemistry and involves the transformation of a β keto allyl ester into a α allyl β ketocarboxylic acid this organic reaction is accompanied by decarboxylation and the final product is a γ δ allylketone the carroll rearrangement is an adaptation of the claisen rearrangement and effectively a decarboxylative allylation
the carstache is a viral sensation first noticed spring of 2010 revolving around people placing a fake plushy mustache on their cars trucks and other automotive vehicles the carstache is a jumbo novelty mustache that attaches quickly and easily to the grille of most cars and trucks following the path of the truck nuts an accessory that gained popularity in the late 90 s the carstache was produced and distributed on the internet soon after its release the carstache went viral trending on services such as twitter and google news search
cartilage – hair hypoplasia chh also known as mckusick type metaphyseal chondrodysplasia is a rare genetic disorder it is a highly pleiotropic disorder that clinically manifests by form of short limbed dwarfism due to skeletal dysplasia variable level of immunodeficiency and predisposition to malignancies in some cases it was first reported in 1965 by mckusick et al actor verne troyer is affected with this form of dwarfism as was actor billy barty who was renowned for saying the name of my condition is cartilage hair syndrome hypoplasia but you can just call me billy
in mathematics the casas alvero conjecture is an open problem about polynomials which have factors in common with their derivatives proposed by eduardo casas alvero in 2001
in toss juggling a cascade is the simplest juggling pattern achievable with an odd number of props the simplest juggling pattern is the three ball cascade this is therefore the first pattern that most jugglers learn balls or other props follow a horizontal figure eight or hourglass figure pattern above the hands in siteswap each throw in a cascade is notated using the number of balls thus a three ball cascade is 3 in the cascade an object is always thrown from a position near the body s midline in an arc passing underneath the preceding throw and toward the other side of the body where it is caught and transported again toward the body s midline for the next throw as a result the balls travel along the figure eight path that is characteristic of the cascade — in the cascade the crossing of the balls between the hands demands that one hand catches at the same rate that the other hand throws synchronization the hands also take turns coupled oscillation
case hardening is a weathering phenomenon of rock surface induration it is observed commonly in felsic alkaline rocks such as nepheline syenite phonolite and trachyte pyroclastic rocks as pyroclastic flow deposit fine air fall deposits and vent filling pyroclastic deposits sedimentary rocks as sandstone and mudstone
casegoods are items of furniture that are built with interior compartments for storage it is an american english term for wooden furniture designed for storage such as cupboards chests of drawers etc a synonym is case furniture casegoods generally refers to furniture made of hard materials such as wood metal glass or plastic examples of casegoods include chests chest of drawers dresser bookshelves and cabinets the term casegoods is sometimes used to refer to commercial use furniture such as beds and sideboards that would be used in a hotel dormitory or student accommodation the same terminology would not generally be used when referring to domestic furniture casegoods are one of the three classifications of furniture the others being upholstery and occasional upholstery refers to furniture that has fabric or leather and padding stretched over a frame occasional furniture includes coffee tables end tables nesting tables ottomans and accent stools
caseous lymphadenitis cla is an infectious disease caused by the bacterium corynebacterium pseudotuberculosis found mostly in goats and sheep that at present has no cure it manifests itself predominantly in the form of large pus filled cysts on the neck sides and udders of goats and sheep the disease is spread mostly from an animal coming in contact with pus from a burst cyst on an infected animal but the disease is highly contagious and is thought to also be spread by coughing or even by flies studies have found cl incidence in commercial goat herds as high as 30
cash collection is a function of accounts receivable it is the recovery of cash from a business or individual with which you have issued an invoice unpaid invoices are considered outstanding invoices are always issued with terms of payment these terms vary widely from cash terms meaning that the invoice is due immediately to many forms of credit terms for example 30 days from date of invoice invoices which remain unpaid for periods longer than their terms indicate are considered overdue it is the aim of the cash collection function of a business to collect monies for all outstanding invoices before they become overdue and to mediate payment arrangements to ensure that invoiced debts do not become doubtful or bad
the cash value of an insurance contract also called the cash surrender value or surrender value is the cash amount offered to the policyowner by the issuing life carrier upon cancellation of the contract this term is normally used with a life insurance or life annuity contract to receive the cash value the policyholder surrenders their rights to future benefits under the policy cash values are usually associated with whole life insurance or endowment life insurance and other forms of permanent life insurance the contract determines for each possible cancellation date the related cash value if the investment of premiums is contractually made in an individual account the cash value is the value of the investments in that account at any particular time minus a surrender charge such cash value credited to an individual account during the tenure of the policy keeps growing with every payment of premium it also increments due to interest credited the policyholder may also be able to use the cash value as collateral on a loan the cash value will often be similar or even equal to the reserve to be held by the insurance company for the net obligations from the contract as such the amount is usually invested and earns investment income for the insurance company which is to some extent forwarded to policyholders of participating contracts since often initial premiums are not invested but covering initial costs associated with selling the contract up front or front end fee the amount available may be significantly lower than the sum of premiums paid for some time initially even zero later interest credited might compensate that initial loss the value of the investment is often subject to a surrender charge in determining the cash value a surrender charge offsets the costs associated with selling the contract and allows these contracts to be sold with little or no up front fees surrender charges are imposed when a contract is cancelled within a set time frame any cancellation after that time frame are not subject to a surrender charge typically surrender charges decrease on an annual schedule until they disappear altogether
caspase 8 deficiency state ceds is a very rare genetic disorder of the immune system it is caused by mutations in the casp 8 gene that encodes the protein caspase 8 the disorder is characterized by splenomegaly and lymphadenopathy in addition to recurrent sinopulmonary infections recurrent mucocutaneous herpesvirus or other viral infections and hypogammaglobulinemia investigators in the laboratory of dr michael lenardo at the national institutes of health described this condition in two siblings from a consanguineous family in 2002 and several more affected family members have since been identified
cassava brown streak virus disease cbsd is a damaging disease of cassava plants and is especially troublesome in east africa it was first identified in 1936 in tanzania and has spread to other coastal areas of east africa from kenya to mozambique recently it was found that two distinct viruses are responsible for the disease cassava brown streak virus cbsv and ugandan cassava brown streak virus ucbsv both have ss rna genomes belong to the genus ipomovirus in the family potyviridae and produce generally similar symptoms in infected plants root rot renders the cassava tuber inedible resulting in severe loss of economic value therefore current research focuses on achieving cultivars that do not develop the necrotic rot this disease is considered to be the biggest threat to food security in coastal east africa and around the eastern lakes
the caster angle or castor angle is the angular displacement of the steering axis from the vertical axis of a steered wheel in a car motorcycle bicycle or other vehicle measured in the longitudinal direction it is the angle between the pivot line in a car an imaginary line that runs through the center of the upper ball joint to the center of the lower ball joint and vertical car racers sometimes adjust caster angle to optimize their car s handling characteristics in particular driving situations
a casting defect is an undesired irregularity in a metal casting process some defects can be tolerated while others can be repaired otherwise they must be eliminated they are broken down into five main categories gas porosity shrinkage defects mold material defects pouring metal defects and metallurgical defects
castle thunder is a sound effect that consists of the sound of a loud thunderclap during a rainstorm it was originally recorded for the 1931 film frankenstein and has since been used in dozens of films television programs and commercials
castleman disease also known as giant or angiofollicular lymph node hyperplasia lymphoid hamartoma angiofollicular lymph node hyperplasia is a group of uncommon lymphoproliferative disorders that share common lymph node histological features that may be localized to a single lymph node unicentric or occur systemically multicentric it is named after benjamin castleman multicentric castleman disease mcd involves hyperactivation of the immune system excessive release of proinflammatory chemicals cytokines proliferation of immune cells b cells and t cells and multiple organ system dysfunction castleman disease must be distinguished from other disorders that can demonstrate castleman like lymph node features including reactive lymph node hyperplasia autoimmune disorders and malignancies while not officially considered a cancer the overgrowth of lymphocytes with this disease is similar to lymphoma and more research is needed to search for small populations of neoplastic cells castleman disease is a focus of intense ongoing research
the castro – stephens coupling is a cross coupling reaction between a copper i acetylide and an aryl halide forming a disubstituted alkyne and a copper i halide the reaction was discovered in 1963 by university of california riverside chemists castro and stephens and is used as a tool in the organic synthesis of organic compounds the reaction has similarities with the much older rosenmund – von braun synthesis 1916 between aryl halides and copper i cyanide and was itself modified in 1973 with as the sonogashira coupling by adding a palladium catalyst and preparing the organocopper compound in situ allowing copper to also be used catalytically a typical reaction is the coupling of iodobenzene with the copper acetylide of phenylacetylene in refluxing pyridine to diphenylacetylene application of castro – stephens coupling with phenyliodine unlike the sonogashira coupling the castro – stephens coupling can produce heterocyclic compounds when a nucleophilic group is ortho to the aryl halide although this typically requires use of dmf as solvent application of castro stephens coupling with o iodobenzoic acid to produce an isocoumarin
a casualty loss is a type of tax loss that is a sudden unexpected or unusual event damage or loss resulting from progressive deterioration of property through a steadily operating cause would not be a casualty loss “ other casualty ” are events similar to “ fire storm or shipwreck ” it is generally held that wherever force is applied to property which the owner taxpayer is either unaware of because of the hidden nature of such application or is powerless to act to prevent the same because of the suddenness thereof or some other disability and damage results in the united states tax deductions are allowed for casualty losses under 26 u s c § 165 which allows deductions for losses sustained during the taxable year and not compensated for by insurance or otherwise such deductions are limited under 26 u s c § 165 h 2 to the amount personal casualty losses exceed personal casualty gains plus 10 percent of the adjusted gross income of the individual within the taxable year additionally under 26 u s c § 165 h 1 individual taxpayers are only allowed to include losses to the extent they exceed 100 for each casualty in addition the deduction is limited to those losses sustained during the taxable year and not compensated by insurance or otherwise
cat scratch disease csd is a common and usually benign infectious disease caused by the bacterium bartonella henselae it is most commonly found in children following a scratch or bite from a cat within about one to two weeks
cat eye syndrome ces or schmid – fraccaro syndrome is a rare condition caused by the short arm p and a small section of the long arm q of human chromosome 22 being present three trisomic or four times tetrasomic usually 3 times instead of the usual two times the term cat eye syndrome was coined because of the particular appearance of the vertical colobomas in the eyes of some patients however over half of the ces patients in the literature do not present with this trait there is no significant reduction in life expectancy in patients who are not afflicted with one of ces life threatening abnormalities
catalan charts catalan maps or catalan portolans are a subtype of the medieval period 1300 – 1500 portolan chart portolan charts are a type of map generated by using a mariner s compass and direct observation to determine the shape and location of coastlines and ports the term portolan means pertaining to ports and harbors and should not be confused with relating to portugal sometimes they are referred to as catalan type portolans or simply catalan portolans two primary subgroups of medieval period portolan maps exist the italian and the catalan while both the italian and catalan maps derive from the same common source readings from a compass combined with direct observation there are several differences both in terms of style and in content
catalepsy from greek κατάληψις seizing grasping is a nervous condition characterized by muscular rigidity and fixity of posture regardless of external stimuli as well as decreased sensitivity to pain
the catalina eddy also called the coastal eddy is a localized weather phenomenon that occurs in the bight of california the mostly convex portion of the southern california coast running from point conception to san diego the catalina eddy leads to the june gloom that is so much a part of the late spring and early summer weather in southern california the eddy gets its name from santa catalina island the channel island closest to the los angeles long beach area the center of an eddy is often located above or near the island while a catalina eddy can develop at any time of the year it is most common between april and september and peaks in june during these months upper level northwesterly flow along the california coast is directed onshore by the channel islands when the flow is blocked by the mountains that ring the los angeles basin to the east and north a counterclockwise vortex is created as temperatures drop after sunset the marine layer deepens and coastal stratus clouds thicken while the vortex is relatively small rarely more than 100 miles 160 km in diameter it can extend into inland valleys and even into the southwestern mojave desert a very strong catalina eddy can be as deep as 6000 feet 1 8 km a catalina eddy is rarely prolonged as the heat over the deserts causes air to rise the resulting pressure gradient and increase in the normal onshore winds causes the vortex to dissipate the result is the common local weather forecast calling for late night and early morning low clouds and fog followed by afternoon sunshine and sea breezes
catalysis kəˈtælᵻsᵻs is the increase in the rate of a chemical reaction due to the participation of an additional substance called a catalyst ˈkætəlᵻst with a catalyst reactions occur faster because they require less activation energy furthermore since they are not consumed in the catalyzed reaction catalysts can continue to act repeatedly often only tiny amounts are required in principle
epilepsy is a chronic neurological condition characterized by recurrent seizures catamenial epilepsy is a subset of epilepsy which includes women whose seizures are exacerbated by their menstrual cycle women with catamenial epilepsy are unusually sensitive to endogenous hormonal changes this seizure exacerbation has a statistically significant positive correlation to serum estradiol estrogen levels and ratios since at least the greek times there has been documented study of women with epilepsy and its correlation to the menstrual cycle these patterns can easily be seen by charting out menses against seizure occurrence and type
catamenial pneumothorax is a condition of collapsed lung pneumothorax occurring in conjunction with menstrual periods catamenial refers to menstruation believed to be caused primarily by endometriosis of the pleura the membrane surrounding the lung
cataphylaxis is the deterioration of the natural defense system of the body due to an infection
cataplexy is a sudden and transient episode of muscle weakness accompanied by full conscious awareness typically triggered by emotions such as laughing crying or terror it is the cardinal symptom of narcolepsy with cataplexy affecting roughly 70 of people who have narcolepsy and is caused by an autoimmune destruction of the neurotransmitter hypocretin also called orexin which regulates arousal and wakefulness cataplexy without narcolepsy is rare and the cause is unknown the term cataplexy originates from the greek κατά kata meaning down and πλῆξις plēxis meaning stroke
in electromagnetics the catapult effect is a phenomenon occurring when a current is passed through two wires connected by a loose wire in a magnetic field the loose wire is then catapulted horizontally away from the magnetic field this occurs due to the magnetic forces acting in the wires and in the magnetic field itself
a cataract is a clouding of the lens in the eye leading to a decrease in vision it can affect one or both eyes often it develops slowly symptoms may include faded colors blurry vision halos around light trouble with bright lights and trouble seeing at night this may result in trouble driving reading or recognizing faces poor vision may also result in an increased risk of falling and depression cataracts are the cause of half of blindness and 33 of visual impairment worldwide cataracts are most commonly due to aging but may also occur due to trauma or radiation exposure be present from birth or occur following eye surgery for other problems risk factors include diabetes smoking tobacco prolonged exposure to sunlight and alcohol either clumps of protein or yellow brown pigment may be deposited in the lens reducing the transmission of light to the retina at the back of the eye diagnosis is by an eye examination prevention includes wearing sunglasses and not smoking early on the symptoms may be improved with eyeglasses if this does not help surgery to remove the cloudy lens and replace it with an artificial lens is the only effective treatment surgery is only needed if the cataracts are causing problems surgery generally results in an improved quality of life cataract surgery is not easily available in many countries which is especially true for women those living in rural areas and those who cannot read about 20 million people globally are blind due to cataracts it is the cause of about 5 of blindness in the united states and nearly 60 of blindness in parts of africa and south america blindness from cataracts occurs in about 10 to 40 per 100 000 children in the developing world and 1 to 4 per 100 000 children in the developed world cataracts become more common with age more than half the people in the united states had cataracts by the age of 80
the cataract microcornea syndrome is the association of congenital cataract and microcornea
the cataracts of the nile are shallow lengths or white water rapids of the nile river between aswan and khartoum where the surface of the water is broken by many small boulders and stones jutting out of the river bed as well as many rocky islets in some places these stretches are punctuated by whitewater and are perhaps well characterized as rapids while at others the water flow is smoother but still shallow
catarrh kəˈtɑːr or catarrhal inflammation is inflammation of the mucous membranes in one of the airways or cavities of the body usually with reference to the throat and paranasal sinuses it can result in a thick exudate of mucus and white blood cells caused by the swelling of the mucous membranes in the head in response to an infection it is a symptom usually associated with the common cold pharyngitis and chesty coughs but it can also be found in patients with adenoiditis otitis media sinusitis or tonsillitis the phlegm produced by catarrh may either discharge or cause a blockage that may become chronic the word catarrh was widely used in medicine since before the era of medical science which explains why it has various senses and in older texts may be synonymous with or vaguely indistinguishable from common cold nasopharyngitis pharyngitis rhinitis or sinusitis the word is no longer as widely used in american medical practice mostly because more precise words are available for any particular pathosis indeed to the extent that it is still used it is no longer viewed nosologically as a disease entity but instead as a symptom a sign or a syndrome of both the term catarrh is found in medical sources from the united kingdom the word has also been common in the folk medicine of appalachia where medicinal plants have been used to treat the inflammation and drainage associated with the condition
a catastrophic illness is a severe illness requiring prolonged hospitalization or recovery examples would include coma cancer leukemia heart attack or stroke these illnesses usually involve high costs for hospitals doctors and medicines and may incapacitate the person from working creating a financial hardship they are the type intended to be covered by high deductible health plans research indicates that the unusual economic environment of the delivery of catastrophic illness care encourages the use of innovative therapies medicare contains a benefit for catastrophic illness
for a description of catastrophic injuries that do not apply to the central nervous system see major trauma a catastrophic injury is a severe injury to the spine spinal cord or brain and may also include skull or spinal fractures this is a subset of the definition for the legal term catastrophic injury which is based on the definition used by the american medical association the national center for catastrophic sport injury research in the united states classifies catastrophic injuries based on the three outcomes associated with them fatality those causing permanent severe functional disability and those causing severe head or neck trauma with no permanent disability a fatal injury may be a direct result of trauma sustained during an activity or may occur indirectly indirect nonfatal catastrophic injury may occur as a result of systemic failure from exertion during an activity such as from cardiovascular conditions heat illness exertional hyponatremia or dehydration or a complication to a nonfatal injury indirect fatalities are usually caused by cardiovascular conditions such as hypertrophic cardiomyopathy and coronary artery disease fatal injury may reveal an unknown underlying anatomical or physiological abnormality individuals with certain anatomical anomalies should not participate in some activities for example contact sports are contraindicated for individuals with an anomalous odontoid process as any violent impact may result in a catastrophic injury this is because a malformed odontoid process may lead to instability between the atlas and axis the c 1 and c 2 cervical vertebrae those with atlanto occipital fusion should also avoid contact sports
a catastrophic kill k kill or complete kill is damage inflicted on an armored vehicle that amounts to complete destruction of the vehicle rendering it both permanently non functional and unrepairable the term knocked out refers to a vehicle which has been damaged to the point of inoperability and abandoned by its crew but is not obviously beyond the point of repair while a knocked out vehicle may be later determined to be irreparable and written off a k kill is more obvious and usually involves the destruction of the vehicle by fire and or explosion among tank crewmen it is also commonly known as a brew up coined from the british world war ii term for lighting a fire in order to brew tea the expression arose because british troops used an old petrol tin with holes punched in the side as a makeshift stove on which to brew their tea the flames licking out of the holes in the side of the tin resembled a burning tank and thus the expression was coined typically a catastrophic kill results in the ignition of any fuel the vehicle may be carrying as well as the detonation cooking off or sympathetic detonation of its ammunition a catastrophic kill does not necessarily preclude the survival of the vehicle s crew although most historical casualties in armored warfare were the result of k kills this type of kill is also associated with the jack in the box effect where a tank s turret is blown skyward due to the overpressure of an ammunition explosion some tank designs employ blow off panels channeling such explosions outside of the vehicle turning an otherwise catastrophic kill into a firepower kill
catatonia is a state of neurogenic motor immobility and behavioral abnormality manifested by stupor it was first described in 1874 by karl ludwig kahlbaum in die katatonie oder das spannungsirresein catatonia or tension insanity in the fifth edition of the diagnostic and statistical manual of mental disorders catatonia is not recognized as a separate disorder but is associated with psychiatric conditions such as schizophrenia catatonic type bipolar disorder post traumatic stress disorder depression and other mental disorders narcolepsy as well as drug abuse or overdose or both it may also be seen in many medical disorders including infections such as encephalitis autoimmune disorders focal neurologic lesions including strokes metabolic disturbances alcohol withdrawal and abrupt or overly rapid benzodiazepine withdrawal it can be an adverse reaction to prescribed medication it bears similarity to conditions such as encephalitis lethargica and neuroleptic malignant syndrome there are a variety of treatments available benzodiazepines are a first line treatment strategy electro convulsive therapy is also sometimes used there is growing evidence for the effectiveness of nmda antagonists for benzodiazepine resistant catatonia antipsychotics are sometimes employed but require caution as they can worsen symptoms and have serious adverse effects
catatumbo lightning spanish relámpago del catatumbo is an atmospheric phenomenon in colombia and venezuela it occurs only over the mouth of the catatumbo river where it empties into lake maracaibo it originates from a mass of storm clouds at a height of more than 1 km and occurs during 140 to 260 nights a year 10 hours per day and up to 280 times per hour it occurs over and around lake maracaibo typically over the bog area formed where the catatumbo river flows into the lake catatumbo lightning changes its frequency along the year and it is different from year to year for example it ceased from january to march 2010 apparently due to drought temporarily raising fears that it might have been extinguished permanently
catecholaminergic polymorphic ventricular tachycardia cpvt also called familial polymorphic ventricular tachycardia fpvt or catecholamine induced polymorphic ventricular tachycardia is a disorder characterized by an abnormal heart rhythm arrhythmia thought to affect as many as one in ten thousand people it is estimated to cause 15 of all unexplained sudden cardiac deaths in young people first recognized in 1975 this condition is due to mutations in genes encoding a calcium channel or proteins related to this channel all mutated proteins participate in the regulation of calcium ion flow in and out of the sarcoplasmatic reticulum of cardiac cells therefore reduced electrical stability of cardiomyocytes may cause the heart to enter a life threatening state of ventricular arrhythmia as response to the natural release of catecholamines from nerve endings on the heart muscle and from the adrenal glands into the circulation this rhythm disturbance prevents the heart from pumping blood appropriately ventricular tachycardia may self terminate or degenerate into ventricular fibrillation causing sudden death unless immediate cardiopulmonary resuscitation is applied
in mathematics categorical algebra is a subfield of algebra that approaches algebra from the categorical point of view for example the study of a symmetric monoidal category as an algebraic object might be considered as a part of categorical algebra it is closely related to homotopical algebra in the recent years the field has been experiencing a turbulent change due to the infusion of topological ideas
a category mistake or category error or categorical mistake or mistake of category is a semantic or ontological error in which things belonging to a particular category are presented as if they belong to a different category or alternatively a property is ascribed to a thing that could not possibly have that property an example is the metaphor time crawled which if taken literally is not just false but a category mistake to show that a category mistake has been committed one must typically show that once the phenomenon in question is properly understood it becomes clear that the claim being made about it could not possibly be true
catel – manzke syndrome is a rare genetic disorder characterized by distinctive abnormalities of the index fingers the classic features of pierre robin syndrome occasionally with additional physical findings pierre robin syndrome refers to a sequence of abnormalities that may occur as a distinct syndrome or as part of another underlying disorder pierre robin syndrome is characterized by an unusually small jaw micrognathia downward displacement or retraction of the tongue glossoptosis and incomplete closure of the roof of the mouth cleft palate it is also linked to hyper mobility syndrome
the catfish effect is the effect that a strong competitor has in causing the weak to better themselves actions done to actively apply this effect for example by the human resource department in an organization are termed catfish management in norway live sardines are several times more expensive than frozen ones and are valued for better texture and flavor it was said that only one ship could bring live sardine home and the shipmaster kept his method a secret after he died people found that there was one catfish in the tank the catfish keeps swimming and the sardines try to avoid this predator this increased level of activity keeps the sardines active instead of becoming sedentary according to vince from catfish the movie in human resource management this is a method used to motivate a team so that each member feels strong competition thus keeping up the competitiveness of the whole team
cathodoluminescence is an optical and electromagnetic phenomenon in which electrons impacting on a luminescent material such as a phosphor cause the emission of photons which may have wavelengths in the visible spectrum a familiar example is the generation of light by an electron beam scanning the phosphor coated inner surface of the screen of a television that uses a cathode ray tube cathodoluminescence is the inverse of the photoelectric effect in which electron emission is induced by irradiation with photons
catholic campus ministry is the presence and ministry or service of the roman catholic church on the campus of a school college or university it may include the setting up of clubs groups and organizations as well as the animating of liturgies retreats recollections and the handling of religion classes workshops and seminars some examples of catholic campus ministries include newman club newman apostolate and catholic student association
in the dungeons dragons fantasy roleplaying game the catoblepas kəˈtoʊblᵻpəs or kæˈtɒblᵻpəs is an aberration
cauda equina syndrome ces is a serious neurologic condition in which damage to the cauda equina causes loss of function of the lumbar plexus nerve roots of the spinal canal below the termination conus medullaris of the spinal cord ces is a lower motor neuron lesion
caudal regression syndrome or sacral agenesis or hypoplasia of the sacrum is a congenital disorder in which there is abnormal fetal development of the lower spine — the caudal partition of the spine it occurs at a rate of approximately one per 25 000 live births
cauliflower ear is a condition that occurs when the external portion of the ear is hit and develops a blood clot or other collection of fluid under the perichondrium this separates the cartilage from the overlying perichondrium that supplies its nutrients causing it to die and resulting in the formation of fibrous tissue in the overlying skin as a result the outer ear becomes permanently swollen and deformed resembling a cauliflower the condition is common in martial arts like boxing mixed martial arts or wrestling and in full contact sports such as rugby union football
causal reasoning is the process of identifying causality the relationship between a cause and its effect the study of causality extends from ancient philosophy to contemporary neuropsychology assumptions about the nature of causality may be shown to be functions of a previous event preceding a later one the first known protoscientific study of cause and effect occurred in aristotle s physics
in linguistics causative alternation is a cross linguistic phenomenon in which certain verbs that express a change of state or a change of degree can be used transitively or intransitively a causatively alternating verb such as open has both a transitive meaning i opened the door and an intransitive meaning the door opened when causatively alternating verbs are used transitively they are called causatives since in the transitive use of the verb the subject is causing the action denoted by the intransitive version when causatively alternating verbs are used intransitively they are referred to as anticausatives or inchoatives because the intransitive variant describes a situation in which the theme participant in this case the door undergoes a change of state becoming for example opened
in law medicine and statistics cause of death is a term which refers to an official determination of conditions resulting in a human s death in modern times such determinations usually become an essential data point of an official death certificate
parkinson s disease pd is a degenerative disorder of the central nervous system most people with pd have idiopathic parkinson s disease having no specific known cause a small proportion of cases however can be attributed to known genetic factors other factors such as environmental toxins herbicides pesticides and fungicides have been associated with the risk of developing pd but no causal relationships have been proven
the causes of poverty include changing trends in a country ’ s economy lack of education high divorce rate which causes feminization of poverty having a culture of poverty overpopulation epidemic diseases such as aids and malaria and environmental problems such as lack of rainfall the united states reduced poverty in the elderly with the creation of the social security program almost 50 percent of people in the world today live on less than 2 50 per day the poverty rate among seniors in the united states is at 9 percent as of 2010 in 1960 the official poverty rate among the elderly was 35 percent the netherlands offers a universal pension and leads the world with a 1 7 percent poverty rate among the elderly extreme poverty may affect the lifespan and the lack of money via some type of pension system increases the poverty rate among the elderly worldwide extreme weather may be a cause of poverty in many countries drought rainfall and flooding are some of the biggest causes of poverty by weather when natural disasters do not gain media attention raising money becomes more difficult this is made worse when governments spend money in the capitals instead of the poorest areas which need it most tony blair in a bbc discussion states that the cause of poverty is inequality of opportunity
caustic embrittlement is the phenomenon in which the material of a boiler becomes brittle due to the accumulation of caustic substances
a cave in is a collapse of a geologic formation mine or structure which may occur during mining or tunneling geologic structures prone to spontaneous cave ins include alvar tsingy and other limestone formations but can also include lava tubes and a variety of other subsurface rock formations glacier caves and other ice formations are very prone to collapse from exposure to warm temperatures or running water in mining the term roof fall is used to refer to a many types of collapses ranging from the fall of a single flake of shale to collapses that form sink holes that reach to the surface however roof falls in mining are not all accidental in longwall mining and retreat mining miners systematically remove all support from under large areas of the mine roof allowing it to settle just beyond the work area the goal in such mining methods is not to prevent roof fall and the ensuing surface subsidence but rather to control it
cavernous hemangioma also called cavernous angioma cavernoma or cerebral cavernous malformation ccm when referring to presence in the brain is a type of blood vessel malformation or hemangioma where a collection of dilated blood vessels form a benign tumor because of this malformation blood flow through the cavities or caverns is slow additionally the cells that form the vessels do not form the necessary junctions with surrounding cells also the structural support from the smooth muscle is hindered causing leakage into the surrounding tissue it is the leakage of blood known as a hemorrhage from these vessels that causes a variety of symptoms known to be associated with this disease
a cavernous liver haemangioma or hepatic haemangioma is a benign tumour of the liver composed of hepatic endothelial cells it is the most common liver tumour and is usually asymptomatic and diagnosed incidentally on radiological imaging liver haemangiomas are thought to be congenital in origin several subtypes exist including the giant hepatic haemangioma which can cause significant complications
cavernous sinus thrombosis cst is the formation of a blood clot within the cavernous sinus a cavity at the base of the brain which drains deoxygenated blood from the brain back to the heart the cause is usually from a spreading infection in the nose sinuses ears or teeth staphylococcus aureus and streptococcus are often the associated bacteria cavernous sinus thrombosis symptoms include decrease or loss of vision chemosis exophthalmos bulging eyes headaches and paralysis of the cranial nerves which course through the cavernous sinus this infection is life threatening and requires immediate treatment which usually includes antibiotics and sometimes surgical drainage
cavernous venous malformations present as rounded bright red or deep purple spongy nodules occurring chiefly on the head and neck and may involve both the skin and the mucous membranes it can be associated with krit 1 ccm 2 or pdcd 10
caviar tongue also termed sublingual varicosities or sublingual varices is a condition characterized by purplish venous ectasias commonly found on the ventral undersurface of the tongue after the age of fifty it is normal for there to be veins visible underneath the tongue partly because the mucous membrane is so thin and translucent in this region but where these vessels become dilated and tortuous they may appear round and black like caviar
cavitary pneumonia is a disease in which the normal lung architecture is replaced by a cavity in a healthy lung oxygen transport occurs at the level of the alveoli each of which has an average size of 0 1 mm these air spaces can become enlarged by a number of processes bacterial infection tuberculosis fungal infection vasculitis granulomatosis with polyangiitis collagen vascular disease sjögren s syndrome or granulomatous disease sarcoidosis
in the brain the cavum veli interpositi cvi is a condition in which the cistern of the velum interpositum becomes dilated the phenomenon usually occurs in newborns axial mr ct show a triangular shaped cerebrospinal fluid csf space between the lateral ventricles on sagittal images cvi can appear as a slit like linear to round ovoid csf collection below the fornices and above the 3 rd ventricle there are usually no associated abnormalities although larger lesions may cause an obstructive hydrocephalus no treatment is usually necessary
cecal bascule is a cause of large bowel obstruction where there is folding of the cecum anteriorly over the ascending colon it is differentiated from cecal volvulus which is caused by rotational torsion of the cecum or ascending colon along its own axis in cecal bascule the base of the cecum folds anteriorly over the ascending colon creating a flap valve obstructing emptying of the cecum the condition can be complicated by necrosis or organ perforation before the diagnosis is made particularly if the ileocecal valve is competent preventing retrograde decompression of the cecum into the ileum
celebrity worship syndrome cws is an obsessive addictive disorder in which a person becomes overly involved with the details of a celebrity s personal life psychologists have indicated that though many people obsess over film television sport and pop stars the only common factor between them is that they are all figures in the public eye
a celestial event is an astronomical phenomenon of interest that involves one or more celestial bodies examples of celestial events include the cyclical phases of the moon solar and lunar eclipses transits and occultations planetary oppositions and conjunctions meteor showers and comet flybys
celibacy syndrome japanese セックスしない症候群 sekkusu shinai shōkōgun is a syndrome not recognized by any medical or psychological body rather it is a media hypothesis claiming that a growing number of japanese adults have lost interest in sexual activity and have also lost interest in romantic love dating and marriage the theory has been reported by unknown members of japan s media according to journalist abigail haworth of the guardian following the report the theory gained wide spread attention in english media outlets in 2013 and was subsequently refuted by several journalists and bloggers
cell potency is a cell s ability to differentiate into other cell types the more cell types a cell can differentiate into the greater its potency potency is also described as the gene activation potential within a cell which like a continuum begins with totipotency to designate a cell with the most differentiation potential pluripotency multipotency oligopotency and finally unipotency potency is taken from the latin term potens which means having power
cell sorting is the ability to separate cells according to their properties these properties can be described as intracellular inside the cell or extracellular outside the cell intracellular processes can include dna rna and protein molecule interaction whereas extracellular physical properties include size shape morphology and surface protein expression
cello scrotum is a hoax medical condition originally published as a brief case report in the british medical journal in 1974 as its name suggests it was purportedly an affliction of the scrotum affecting male players of the cello
cellulite also known as adiposis edematosa dermopanniculosis deformans status protrusus cutis gynoid lipodystrophy and orange peel syndrome is the herniation of subcutaneous fat within fibrous connective tissue that manifests topographically as skin dimpling and nodularity often on the pelvic region specifically the buttocks lower limbs and abdomen cellulite is a secondary sex characteristic occurring in most postpubescent females a review gives a prevalence of 85 98 of women indicating that it is physiologic rather than pathologic it can result from a complex combination of factors ranging from hormones to heredity
cellulitis is a bacterial infection involving the inner layers of the skin it specifically affects the dermis and subcutaneous fat signs and symptoms include an area of redness which increases in size over a couple of days the borders of the area of redness are generally not sharp and the skin may be swollen while the redness often turns white when pressure is applied this is not always the case the area of infection is usually painful lymphatic vessels may occasionally be involved and the person may have a fever and feel tired the legs and face are the most common site involved though cellulitis can occur on any part of the body the leg is typically affected following a break in the skin other risk factors include obesity leg swelling and old age for face infections a break in the skin beforehand is not usually the case the bacteria most commonly involved are streptococci and staphylococcus aureus in contrast to cellulitis erysipelas is a bacterial infection involving the more superficial layers of the skin presents with an area of redness with well defined edges and more often is associated with fever more serious infections such as an underlying bone infection or necrotizing fasciitis should be ruled out diagnosis is usually based on the presenting signs and symptoms with cell culture rarely being possible treatment with antibiotics taken by mouth such as cephalexin amoxicillin or cloxacillin is often used in those who are seriously allergic to penicillin erythromycin or clindamycin may be used when methicillin resistant s aureus mrsa is a concern doxycycline or trimethoprim sulfamethoxazole may in addition be recommended concern is related to the presence of pus or previous mrsa infections steroids may speed recovery in those on antibiotics elevating the infected area may be useful as may pain killers around 95 of people are better after seven to ten days of treatment potential complications include abscess formation bacterial skin infections affected about 155 million people and cellulitis occurred in about 37 million people in 2013 this is about two of every 1000 people per year cellulitis in 2013 resulted in about 30 000 deaths worldwide in the united kingdom cellulitis was the reason for 1 6 of admissions to hospital
celtic mazes are straight line spiral patterns that have been drawn all over the world since prehistoric times the patterns originate in early celtic developments in stone and metal work and later in medieval insular art prehistoric spiral designs date back to gavrinis c 3500 bce the straight line spirals of celtic labyrinths originated in chevrons and lozenges and are drawn by the celts using a connect the dots method celtic labyrinths are found among carvings at camonica valley occupied by the celts early in the first millennium most older than the one knossos or classical style example found there the mythology associated with the labyrinths also suggest celtic origin for example the labyrinths containing eyes or a figure with horns and a snake about its waist imply the deity cernunnos lastly celtic examples resembling the cretan model but featuring path line reversal the path of one is traceable as the line of the other suggest celtic pre knowledge of their construction methods of constructing classical labyrinths from figure with serpent through waist and ocular spiral may be demonstrated
a cementicle is a small spherical or ovoid calcified mass embedded within or attached to the cementum layer on the root surface of a tooth or lying free within the periodontal ligament they tend to occur in elderly individuals there are 3 types free cementicle not attached to cementum attached sessile cementicle attached to the cementum surface also termed exocementosis embedded interstitial cementicle with advancing age the cementum thickens and the cementicle may become incorporated into the cementum layer they may be visible on a radiograph x ray they may appear singly or in groups and are most commonly found at the tip of the root their size is variable but generally they are small about 0 2 mm 0 3 mm in diameter cementicles are usually acellular and may contain either fibrillar or afibrillar cementum or a mixture of both cementicles are the result of dystrophic calcification but the reason why this takes place is unclear cementicles are thought to form when calcification occurs around a nidus a precipitating center around this nidus they slowly enlarge by further deposition of calcium salts examples of how cementicles are thought to form include calcification due to degenerative changes in the epithelial cell rests of malassez calcification of thrombosed blocked capillaries in the periodontal ligament i e a phlebolith microtrauma to sharpey s fibres causes small spicules of cementum or alveolar bone to splinter into the periodontal membrane some do not consider these as true cementicles
cemento osseous dysplasia cod is a benign condition of the jaws that may arise from the fibroblasts of the periodontal ligaments it is most common in african american females the three types are periapical cemental dysplasia common in blacks focal cemento osseous dysplasia caucasians and florid cemento osseous dysplasia blacks periapical occurs most commonly in the mandibular anterior teeth while focal appears predominantly in the mandibular posterior teeth and florid in both maxilla and mandible in multiple quadrants
cementoblastoma or benign cementoblastoma is a relatively rare benign neoplasm of the cementum of the teeth it is derived from ectomesenchyme of odontogenic origin less than 0 69 – 8 of all odontogenic tumors
cementoma is an odontogenic tumor of cementum it usually occurs after root development is finished found predominantly in african american women older than 40 it is found most commonly in the mandible in the region of the lower molar teeth it causes distortion of surrounding areas but is a usually painless growth at least initially considerable thickening of the cementum can often be observed a periapical form is also recognized
cenani – lenz syndactylism also known as cenani – lenz syndrome or cenani – syndactylism is an autosomal recessive congenital malformation syndrome involving both upper and lower extremities
céngkok old orthography chengkok are patterns played by the elaborating instruments in the javanese gamelan they are melodic formula that lead to a sèlèh following the rules of the pathet of the piece the most elaborate cengkok repertoire is that of the gendér barung the gambang and siter on the other hand do not have such formalized sets of cengkok and therefore may vary more from performer to performer most cengkok derive from the vocal repertoire and many have names that originally came from lyrics like the well known ayu kuning they may incorporate pre existent melodic patterns through a process of centonization
in statistics engineering economics and medical research censoring is a condition in which the value of a measurement or observation is only partially known for example suppose a study is conducted to measure the impact of a drug on mortality rate in such a study it may be known that an individual s age at death is at least 75 years but may be more such a situation could occur if the individual withdrew from the study at age 75 or if the individual is currently alive at the age of 75 censoring also occurs when a value occurs outside the range of a measuring instrument for example a bathroom scale might only measure up to 300 pounds 140 kg if a 350 lb 160 kg individual is weighed using the scale the observer would only know that the individual s weight is at least 300 pounds 140 kg the problem of censored data in which the observed value of some variable is partially known is related to the problem of missing data where the observed value of some variable is unknown censoring should not be confused with the related idea truncation with censoring observations result either in knowing the exact value that applies or in knowing that the value lies within an interval with truncation observations never result in values outside a given range values in the population outside the range are never seen or never recorded if they are seen note that in statistics truncation is not the same as rounding
a centipede bite is an injury resulting from the action of a centipede s forcipules pincer like appendages that pierce the skin and inject venom into the wound such a wound is not technically a bite as the forcipules are modified first pair of legs rather than true mouthparts clinically the wound is viewed as a cutaneous condition characterized by paired hemorrhagic marks that form a chevron shape caused by the large paired forcipules of the centipede the centipede s venom causes pain and swelling in the area of the bite and may cause other reactions throughout the body the majority of bites are not life threatening to humans and present the greatest risk to children and those who develop allergic reactions
central cord syndrome ccs is the most common form of cervical spinal cord injury it is characterized by loss of motion and sensation in arms and hands it usually results from trauma which causes damage to the neck leading to major injury to the central grey matter of the spinal cord the syndrome is more common in people over the age of 50 because osteoarthritis in the neck region causes weakening of the vertebrae ccs most frequently occurs among older persons with cervical spondylosis however it also may occur in younger individuals ccs is the most common incomplete spinal cord injury syndrome it accounts for approximately 9 of traumatic scis after an incomplete injury the brain still has the capacity to send and receive some signals below the site of injury sending and receiving of signals to and from parts of the body is reduced not entirely blocked ccs gives a greater motor loss in the upper limbs than in the lower limbs with variable sensory loss it was first described by schneider in 1954 it is generally associated with favorable prognosis for some degree of neurological and functional recovery however factors such as age preexisting conditions and extent of injury will affect the recovery process
central core disease ccd also known as central core myopathy is an autosomal dominant congenital myopathy inborn muscle disorder it was first described by shy and magee in 1956 it is characterized by the appearance of the myofibril under the microscope
central facial palsy colloquially referred to as central seven is a symptom or finding characterized by paralysis or paresis of the lower half of one side of the face it usually results from damage to upper motor neurons of the facial nerve the facial motor nucleus has dorsal and ventral divisions that contain lower motor neurons supplying the muscles of the upper and lower face respectively the dorsal division receives bilateral upper motor neuron input i e from both sides of the brain while the ventral division receives only contralateral input i e from the opposite side of the brain thus lesions of the corticobulbar tract between the cerebral cortex and pons and the facial motor nucleus destroy or reduce input to the ventral division but ipsilateral input i e from the same side to the dorsal division is retained as a result central facial palsy is characterized by hemiparalysis or hemiparesis of the contralateral muscles of facial expression but not the muscles of the forehead
central giant cell granuloma cgcg is a benign condition of the jaws it is twice as likely to affect women and is more likely to occur in 20 to 40 year old people central giant cell granulomas are more common in the mandible and often cross the midline
central hypoventilation syndrome chs is a respiratory disorder that results in respiratory arrest during sleep chs can either be congenital cchs or acquired ahcs later in life it is fatal if untreated it is also known by ondine s curse achs can develop as a result of severe injury or trauma to the brain or brainstem congenital cases are very rare and involves a failure of autonomic control of breathing in 2006 there were only about 200 known cases worldwide as of 2008 only 1000 total cases were known the diagnosis may be delayed because of variations in the severity of the manifestations or lack of awareness in the medical community particularly in milder cases however as there have been cases where asymptomatic family members also were found to have cchs it may be that these figures only reflect those found to require mechanical ventilation in all cases episodes of apnea occur in sleep but in a few patients at the most severe end of the spectrum apnea also occurs while awake although rare cases of long term untreated cchs have been reported and are termed late onset cchs lo cchs cases that go undiagnosed until later life and middle age although the symptoms are usually obvious in retrospect there have however even been cases of lo cchs where family members found to have it have been asymptomatic again lack of awareness in the medical community may cause such a delay cchs susceptibility is not known to be affected by gender
central nervous system cavernous hemangioma is a cavernous hemangioma that arises in the central nervous system cns it can be considered to be a variant of hemangioma and is characterized by grossly large dilated blood vessels and large vascular channels less well circumscribed and more involved with deep structures with a single layer of endothelium and an absence of neuronal tissue within the lesions these thinly walled vessels resemble sinusoidal cavities filled with stagnant blood blood vessels in patients with cerebral cavernous malformations ccm can range from a few millimeters to several centimeters in diameter most lesions occur in the brain but any organ may be involved
a central nervous system cyst is a cyst that primarily presents in the tissue of the central nervous system examples include choroid plexus cyst arachnoid cyst porencephaly
central nervous system diseases also known as central nervous system disorders are disorders of the structure or function of either the spinal cord e g a myelopathy or brain e g an encephalopathy both of which are part of the central nervous system
central nervous system fatigue or central fatigue is a form of fatigue that is associated with changes in the synaptic concentration of neurotransmitters within the central nervous system cns including the brain and spinal cord which affects exercise performance and muscle function and cannot be explained by peripheral factors that affect muscle function in healthy individuals central fatigue can occur from prolonged exercise and is associated with neurochemical changes in the brain primarily involving serotonin 5 ht noradrenaline and dopamine central fatigue plays an important role in endurance sports and also highlights the importance of proper nutrition in endurance athletes
a central nervous system viral disease is a viral infection that affects the central nervous system an example is poliomyelitis other examples include members of the polyomavirus family
central neurocytoma abbreviated cnc is an extremely rare ordinarily benign intraventricular brain tumour that typically forms from the neuronal cells of the septum pellucidum the majority of central neurocytomas grow inwards into the ventricular system forming interventricular neurocytomas this leads to two primary symptoms of cncs blurred vision and increased intracranial pressure treatment for a central neurocytoma typically involves surgical removal with an approximate 1 in 5 chance of recurrence central neurocytomas are classified as a grade ii tumor under the world health organization s classification of tumors of the nervous system
central neurogenic hyperventilation cnh is an abnormal pattern of breathing characterized by deep and rapid breaths at a rate of at least 25 breaths per minute increasing irregularity of this respiratory rate generally is a sign that the patient will enter into coma cnh is unrelated to other forms of hyperventilation like kussmaul s respirations cnh is the human body s response to reduced carbon dioxide levels in the blood this reduction in carbon dioxide is caused by contraction of cranial arteries from damage caused by lesions in the brain stem however the mechanism by which cnh arises as a result from these lesions is still very poorly understood current research has yet to provide an effective means of treatment for the rare number of patients who are diagnosed with this condition
the central odontogenic fibroma is a rare benign odontogenic tumor it is more common in adults with the average age being 40 it is twice as likely to affect women than men it is usually found either in the anterior maxilla or the posterior mandible radiographically it presents with either radiolucency or mixed radiolucency opaque the simple type is characterized by delicate fibrillar stroma of collagen containing fibroblasts the who type is characterized by more mature fibrillar stroma of collagen treatment is by surgical removal
central ossifying fibroma is a benign neoplasm that may arise from the fibroblasts of the periodontal ligaments it is more likely to affect women in their third and fourth decades central ossifying fibromas are more common in the mandible around premolars and molars
central pain syndrome is a neurological condition caused by damage or malfunction in the central nervous system cns which causes a sensitization of the pain system the extent of pain and the areas affected are related to the cause of the injury
central pontine myelinolysis cpm also known as osmotic demyelination syndrome or central pontine demyelination is a neurological disease caused by severe damage of the myelin sheath of nerve cells in the brainstem more precisely in the area termed the pons predominately of iatrogenic etiology it is characterized by acute paralysis dysphagia difficulty swallowing and dysarthria difficulty speaking and other neurological symptoms central pontine myelinolysis was first described by adams et al in 1958 as a clinicopathological entity the original paper described four cases with fatal outcomes and the findings on autopsy the aetiology was not known then but the authors suspected the cause to be either a toxin or a nutritional deficiency ‘ central pontine ’ indicated the site of the lesion and ‘ myelinolysis ’ was used to emphasise that myelin was affected preferentially compared to the other neuronal elements the authors intentionally avoided the term ‘ demyelination ’ to describe the condition in order to differentiate the pathology of this condition from multiple sclerosis and other neuroinflammatory disorders in which myelin loss is associated with inflammation it can also occur outside the pons the term osmotic demyelination syndrome is similar to central pontine myelinolysis but also includes areas outside the pons central pontine myelinolysis presents most commonly as a complication of treatment of patients with profound life threatening hyponatremia low sodium it occurs as a consequence of a rapid rise in serum tonicity following treatment in individuals with chronic severe hyponatremia who have made intracellular adaptations to the prevailing hypotonicity hyponatremia should be corrected at a rate of no more than 8 12 mmol l of sodium per day to prevent central pontine myelinolysis although less common it may also present in patients with a history of chronic alcoholism or other conditions related to decreased liver function in these cases the condition is often unrelated to correction of sodium or electrolyte imbalance
central retinal artery occlusion crao is a disease of the eye where the flow of blood through the central retinal artery is blocked occluded there are several different causes of this occlusion the most common is carotid artery atherosclerosis
the central retinal vein is the venous equivalent of the central retinal artery and like that blood vessel it can suffer from occlusion central retinal vein occlusion also crvo similar to that seen in ocular ischemic syndrome since the central retinal artery and vein are the sole source of blood supply and drainage for the retina such occlusion can lead to severe damage to the retina and blindness due to ischemia restriction in blood supply and edema swelling it can also cause glaucoma nonischemic crvo is the milder form of the disease it may progress to the more severe ischemic type
central serous retinopathy csr also known as central serous chorioretinopathy csc or cscr is an eye disease which causes visual impairment often temporary usually in one eye when the disorder is active it is characterized by leakage of fluid under the retina that has a propensity to accumulate under the central macula this results in blurred or distorted vision metamorphopsia a blurred or gray spot in the central visual field is common when the retina is detached reduced visual acuity may persist after the fluid has disappeared the disease is considered idiopathic but mostly affects white males in the age group 20 to 50 and occasionally other groups the condition is believed to be exacerbated by stress or corticosteroid use
central sleep apnea csa or central sleep apnea syndrome csas is a sleep related disorder in which the effort to breathe is diminished or absent typically for 10 to 30 seconds either intermittently or in cycles and is usually associated with a reduction in blood oxygen saturation csa is usually due to an instability in the body s feedback mechanisms that control respiration central sleep apnea can also be an indicator of arnold – chiari malformation
central venous pressure cvp is the blood pressure in the venae cavae near the right atrium of the heart cvp reflects the amount of blood returning to the heart and the ability of the heart to pump the blood back into the arterial system cvp is often a good approximation of right atrial pressure rap although the two terms are not identical as a pressure differential can sometimes exist between the venae cavae and the right atrium cvp and rap can differ when arterial tone is altered this can be graphically depicted as changes in the slope of the venous return plotted against right atrial pressure where central venous pressure increases but right atrial pressure stays the same vr cvp − rap cvp has been and often still is used as a surrogate for preload and changes in cvp in response to infusions of intravenous fluid have been used to predict volume responsiveness i e whether more fluid will improve cardiac output however there is increasing evidence that cvp whether as an absolute value or in terms of changes in response to fluid does not correlate with ventricular volume i e preload or volume responsiveness and so should not be used to guide intravenous fluid therapy nevertheless cvp monitoring is a useful tool to guide hemodynamic therapy the cardiopulmonary baroreflex responds to an increase in cvp by decreasing systemic vascular resistance while increasing heart rate and ventricular contractility in dogs
centre line cl thrust is an absence of asymmetrical thrust from an aircraft for example a boeing 757 has a wide distance between engine 1 and engine 2 if it were to sustain an engine failure in the 1 engine the asymmetrical thrust would cause the plane to yaw on the vertical axis to the left but on cl thrust airplanes this is not the case the following aircraft are all classified by the faa as cl thrust aircraft t 37 t 38 f 14 f 15 eagle f 18 f 22
centrifugal abdominal lipodystrophy also known as centrifugal lipodystrophy lipodystrophia centrifugalis abdominalis infantalis is a skin condition characterized by areas of subcutaneous fat loss that slowly enlarge
centrilobular necrosis refers to the necrosis of the centrilobular tissue of the hepatic lobule the centrilobular zone of the lobule is most prone to metabolic toxins such as those generated in alcoholic hepatitis
centrofacial lentiginosis is a cutaneous condition characterized by lentigines on the nose and adjacent cheeks
centronuclear myopathies cnm are a group of congenital myopathies where cell nuclei are abnormally located in skeletal muscle cells in cnm the nuclei are located at a position in the center of the cell instead of their normal location at the periphery symptoms of cnm include severe hypotonia hypoxia requiring breathing assistance and scaphocephaly among centronuclear myopathies the x linked myotubular myopathy form typically presents at birth and is thus considered a congenital myopathy however some centronuclear myopathies may present later in life
cephalic disorders from the greek word κεφάλη meaning head are congenital conditions that stem from damage to or abnormal development of the budding nervous system cephalic means head or head end of the body cephalic disorders are not necessarily caused by a single factor but may be influenced by hereditary or genetic conditions nutritional deficiencies or by environmental exposures during pregnancy such as medication taken by the mother maternal infection or exposure to radiation such disorders are more common in areas of the former soviet union affected by nuclear waste disposal problems such as the area around the mayak plant in chelyabinsk russia some cephalic disorders occur when the cranial sutures the fibrous joints that connect the bones of the skull join prematurely most cephalic disorders are caused by a disturbance that occurs very early in the development of the fetal nervous system the human nervous system develops from a small specialized plate of cells on the surface of the embryo early in development this plate of cells forms the neural tube a narrow sheath that closes between the third and fourth weeks of pregnancy to form the brain and spinal cord of the embryo four main processes are responsible for the development of the nervous system cell proliferation the process in which nerve cells divide to form new generations of cells cell migration the process in which nerve cells move from their place of origin to the place where they will remain for life cell differentiation the process during which cells acquire individual characteristics and cell death a natural process in which cells die damage to the developing nervous system is a major cause of chronic disabling disorders and sometimes death in infants children and even adults the degree to which damage to the developing nervous system harms the mind and body varies enormously many disabilities are mild enough to allow those afflicted to eventually function independently in society others are not some infants children and adults die others remain totally disabled and an even larger population is partially disabled functioning well below normal capacity throughout life the national institute of neurological disorders and stroke ninds is currently conducting and supporting research on normal and abnormal brain and nervous system development
a cephalic presentation or head presentation or head first presentation is a situation at childbirth where the fetus is in a longitudinal lie and the head enters the pelvis first the most common form of cephalic presentation is the vertex presentation where the occiput is the leading part the part that first enters the birth canal all other presentations are abnormal malpresentations which are either more difficult to deliver or not deliverable by natural means
a cephalhaematoma british english or cephalhematoma american english is a hemorrhage of blood between the skull and the periosteum of a newborn baby secondary to rupture of blood vessels crossing the periosteum because the swelling is subperiosteal its boundaries are limited by the individual bones in contrast to a caput succedaneum
cephalo pelvic disproportion exists when the capacity of the pelvis is inadequate to allow the fetus to negotiate the birth canal this may be due to a small pelvis a nongynecoid pelvic formation a large fetus an unfavorable orientation of the fetus or a combination of these factors certain medical conditions may distort pelvic bones such as rickets or a pelvic fracture and lead to cpd transverse diagonal measurement has been proposed as a predictive method
cerebellar abiotrophy ca also referred to as the cerebellar cortical abiotrophy cca is a genetic neurological disease in animals best known to affect certain breeds of horses dogs and cats it can also develop in human beings it develops when the neurons known as purkinje cells located in the cerebellum of the brain begin to die off these cells affect balance and coordination they have a critical role to play in the brain the purkinje layer allows communication between the granular and molecular cortical layers in the cerebellum put simply without purkinje cells an animal loses its sense of space and distance making balance and coordination difficult people with damage to the cerebellum can experience symptoms like unsteady gait poor muscle control and trouble speaking or swallowing abiotrophy means the loss of a vital nutritive factor the exact cause of cerebellar abiotrophy is not known but it is thought to be due to an intrinsic metabolic defect in most cases the purkinje neurons begin to die off shortly after the animal is born and the condition is noticeable when the animal is less than six months old though sometimes the onset of symptoms is gradual and the animal is much older before the owner or caretaker notices a problem ca cannot be prevented other than by selective breeding to avoid the gene and it cannot be cured genetic testing can detect carriers in addition to dogs and horses there also have been cases of cerebellar abiotrophy in siamese and domestic shorthair cats in angus polled hereford charolais and holstein friesian cattle merino and wiltshire sheep and yorkshire pigs
cerebellar agenesis is a rare condition in which a brain develops without the cerebellum the cerebellum controls smooth movement and when it does not develop the rest of the brain must compensate which it cannot do completely the condition is not fatal on its own but people born without a cerebellum experience severe developmental delays language deficits and neurological abnormalities as children with cerebellar agenesis get older their movements usually improve it can co exist with other severe malformations of the central nervous system like anencephaly holoprosencephaly and microencephaly the condition was first reported in 1831 10 cases had been reported as of 1998 agenesis of one half or another part of the cerebellum is more common than complete agenesis cerebellar agenesis can be caused by mutations in the ptf 1 a gene
cerebellar ataxia is a form of ataxia originating in the cerebellum
cerebellar cognitive affective syndrome ccas also called schmahmann s syndrome is a condition that follows from lesions damage to the cerebellum of the brain this syndrome described by dr jeremy schmahmann and his colleagues refers to a constellation of deficits in the cognitive domains of executive function spatial cognition language and affect resulting from damage to the cerebellum impairments of executive function include problems with planning set shifting abstract reasoning verbal fluency and working memory and there is often perseveration distractibility and inattention language problems include dysprosodia agrammatism and mild anomia deficits in spatial cognition produce visual – spatial disorganization and impaired visual – spatial memory personality changes manifest as blunting of affect or disinhibited and inappropriate behavior these cognitive impairments result in an overall lowering of intellectual function ccas challenges the traditional view of the cerebellum being responsible solely for regulation of motor functions it is now thought that the cerebellum is responsible for monitoring both motor and nonmotor functions the nonmotor deficits described in ccas are believed to be caused by dysfunction in cerebellar connections to the cerebral cortex and limbic system
cerebellar hypoplasia is a heterogeneous group of disorder of cerebellar maldevelopment presenting as early onset non progressive ataxia hypotonia and motor learning disability various causes has been incriminated like hereditary metabolic toxic and viral agents first reported by crouzon in 1929 in 1940 an unclaimed body came for dissection in london hospital and was discovered to have no cerebellum this unique case was appropriately named human brain without a cerebellum and was used every year in the department of anatomy at cambridge university in a neuroscience course for medical students
cerebellar hypoplasia is a disorder found in cats and dogs in which the cerebellum is not completely mature at birth
cerebellar stroke syndrome is a condition in which the circulation to the cerebellum is impaired due to a lesion of the superior cerebellar artery anterior inferior cerebellar artery or the posterior inferior cerebellar artery cardinal signs include vertigo headache vomiting and ataxia cerebellar strokes account for only 2 3 of the 600 000 strokes that occur each year in the united states they are far less common than strokes which occur in the cerebral hemispheres in recent years mortality rates have decreased due to advancements in health care which include earlier diagnosis through mri and ct scanning advancements have also been made which allow earlier management for common complications of cerebellar stroke such as brainstem compression and hydrocephalus research is still needed in the area of cerebellar stroke management however it has been proposed that several factors may lead to poor outcomes in individuals who suffer from cerebellar stroke these factors include 1 declining levels of consciousness 2 new signs of brainstem involvement 3 progressing hydrocephalus 4 stroke to the midline of the cerebellum aka the vermis
the cerebellopontine angle is the anatomic space between the cerebellum and the pons filled with cerebrospinal fluid this is a common site for the growth of acoustic neuromas or schwannomas a distinct neurologic syndrome of deficits occurs due to the anatomic proximity of the cerebellopontine angle to specific cranial nerves indications include unilateral hearing loss 85 speech impediments disequilibrium tremors or other loss of motor control
cerebral amyloid angiopathy caa also known as congophilic angiopathy is a form of angiopathy in which amyloid deposits form in the walls of the blood vessels of the central nervous system the term congophilic is used because the presence of the abnormal aggregations of amyloid can be demonstrated by microscopic examination of brain tissue after application of a special stain called congo red the amyloid material is only found in the brain and as such the disease is not related to other forms of amyloidosis
a cerebral arteriovenous malformation avm is an abnormal connection between the arteries and veins in the brain
cerebral contusion latin contusio cerebri a form of traumatic brain injury is a bruise of the brain tissue like bruises in other tissues cerebral contusion can be associated with multiple microhemorrhages small blood vessel leaks into brain tissue contusion occurs in 20 – 30 of severe head injuries a cerebral laceration is a similar injury except that according to their respective definitions the pia arachnoid membranes are torn over the site of injury in laceration and are not torn in contusion the injury can cause a decline in mental function in the long term and in the emergency setting may result in brain herniation a life threatening condition in which parts of the brain are squeezed past parts of the skull thus treatment aims to prevent dangerous rises in intracranial pressure the pressure within the skull contusions are likely to heal on their own without medical intervention
cerebral dysgenesis – neuropathy – ichthyosis – keratoderma syndrome also known as cednik syndrome is a cutaneous condition caused by mutation in the snap 29 gene
cerebral edema or cerebral oedema is excess accumulation of fluid in the intracellular or extracellular spaces of the brain
cerebral hypoxia is a form of hypoxia reduced supply of oxygen specifically involving the brain when the brain is completely deprived of oxygen it is called cerebral anoxia there are four categories of cerebral hypoxia they are in order of severity diffuse cerebral hypoxia dch focal cerebral ischemia cerebral infarction and global cerebral ischemia prolonged hypoxia induces neuronal cell death via apoptosis resulting in a hypoxic brain injury cases of total oxygen deprivation are termed anoxia which can be hypoxic in origin reduced oxygen availability or ischemic in origin oxygen deprivation due to a disruption in blood flow brain injury as a result of oxygen deprivation either due to hypoxic or anoxic mechanisms are generally termed hypoxic anoxic injuries hai hypoxic ischemic encephalopathy hie is a condition that occurs when the entire brain is deprived of an adequate oxygen supply but the deprivation is not total while hie is associated in most cases with oxygen deprivation in the neonate due to birth asphyxia it can occur in all age groups and is often a complication of cardiac arrest
a cerebral infarction is a type of ischemic stroke resulting from a blockage in the blood vessels supplying blood to the brain it can be atherothrombotic or embolic stroke caused by cerebral infarction should be distinguished from two other kinds of stroke cerebral hemorrhage and subarachnoid hemorrhage a cerebral infarction occurs when a blood vessel that supplies a part of the brain becomes blocked or leakage occurs outside the vessel walls this loss of blood supply results in the death of tissue in that area cerebral infarctions vary in their severity with one third of the cases resulting in death
a cerebral laceration is a type of traumatic brain injury that occurs when the tissue of the brain is mechanically cut or torn the injury is similar to a cerebral contusion however according to their respective definitions the pia arachnoid membranes are torn over the site of injury in laceration and are not torn in contusion lacerations require greater physical force to cause than contusions but the two types of injury are grouped together in the icd 9 and icd 10 classification systems
cerebral salt wasting syndrome csws is a rare endocrine condition featuring a low blood sodium concentration and dehydration in response to trauma injury or the presence of tumors in or surrounding the brain this form of low blood sodium is due to excessive sodium excretion from the normally functioning kidney due to a disorder of the cerebrum of the brain the condition was initially described in 1950 half a century later aetiology and management of csws remains controversial one problem is that there is no diagnostic test for csws
in medicine cerebral softening encephalomalacia is a localized softening of the brain substance due to hemorrhage or inflammation three varieties distinguished by their color and representing different stages of the morbid process are known respectively as red yellow and white softening
cerebral vasculitis or central nervous system vasculitis sometimes the word angiitis is used instead of vasculitis is vasculitis inflammation of the blood vessel wall involving the brain and occasionally the spinal cord it affects all of the vessels very small blood vessels capillaries medium size blood vessels arterioles and venules or large blood vessels arteries and veins if blood flow in a vessel with vasculitis is reduced or stopped the parts of the body that receive blood from that vessel begins to die it may produce a wide range of neurological symptoms such as headache skin rashes feeling very tired joint pains difficulty moving or coordinating part of the body changes in sensation and alterations in perception thought or behavior as well as the phenomena of a mass lesion in the brain leading to coma and herniation some of its signs and symptoms may resemble multiple sclerosis 10 have associated bleeding in the brain
cerebral venous sinus thrombosis cvst is the presence of acute thrombosis a blood clot in the dural venous sinuses which drain blood from the brain symptoms may include headache abnormal vision any of the symptoms of stroke such as weakness of the face and limbs on one side of the body and seizures the diagnosis is usually by computed tomography ct cat scan or magnetic resonance imaging mri employing radiocontrast to demonstrate obstruction of the venous sinuses by thrombus treatment is with anticoagulants medication that suppresses blood clotting and rarely thrombolysis enzymatic destruction of the blood clot given that there is usually an underlying cause for the disease tests may be performed to look for these the disease may be complicated by raised intracranial pressure which may warrant surgical intervention such as the placement of a shunt
cerebritis is an infection of the brain that normally leads to the formation of an abscess within the brain itself it is the inflammation of the cerebrum a structure within the brain which performs a number of important functions including most of the things which people associate with being human such as memory and speech it is also defined as a purulent nonencapsulated parenchymal infection of brain which is characterized by nonspecific features on ct ill defined low density area with peripheral enhancement and cannot reliably be distinguished from neoplasms cerebritis usually occurs as a result of an underlying condition which causes the inflammation of the brain tissue it is commonly found in patients with lupus lupus cerebritis may occur in adults and children the duration of the central nervous system involvement may vary from a few minutes as in classic migraine or a transient ischemic attack to years as in dementia resulting neurological deficits may be transient or permanent occasionally resulting in death
cerebroretinal microangiopathy with calcifications and cysts crmcc is a rare genetic disorder which affects multiple organs its hallmarks are widespread progressive calcifications cysts and abnormalities of the white matter of the brain usually occurring together with abnormalities of the blood vessels of the retina additional features include poor prenatal growth preterm birth anemia osteopenia and bone fractures and gastrointestinal bleeding it is caused by compound heterozygous mutations in the conserved telomere maintenance component 1 ctc 1 gene but its exact pathophysiology is still not well understood cerebroretinal microangiopathy with calcifications and cysts is alternatively known as the coats plus syndrome a reference to its most typical ocular phenotype
a cerebrospinal fluid leak csfl is a medical condition where the cerebrospinal fluid in the brain leaks out of the dura mater this can be due to a spontaneous cerebrospinal fluid leak or result from different causes such as a lumbar puncture or physical trauma while high csf pressure can make lying down unbearable low csf pressure due to a leak is often relieved somewhat by lying flat on the back
csf rhinorrhoea refers to the drainage of cerebrospinal fluid through the nose measures of csf components such as glucose have been used in the past but are neither sensitive nor specific beta 2 transferrin however has been shown to have a high positive predictive value it has also been noted to be characterized by unilateral discharge it is a sign of basal skull fracture management includes watchful waiting leaks often stop spontaneously if this does not occur then neurosurgical closure is necessary to prevent the spread of infection to the meninges other signs of basal skull fracture includes csf otorrhoea drainage of csf through the ear it can have devastating complications in some patients as the communication between the nasal cavity and the cerebrospinal fluid and cns can result in bacterial infections of the cns that can have catastrophic effects on the patient csf rhinorrhoea can also be a symptom of a pituitary adenoma spontaneous csf rhinorrhea the most common congenital or acquired defect in the skull base bones anterior cranial fossa at the spontaneous nasal liquorrhea localized in following formation sphenoid sinus 43 ethmoid bone 29 cribriform plate 29
cerebrotendineous xanthomatosis or cerebrotendinous xanthomatosis ctx also called cerebral cholesterosis is an autosomal recessive form of xanthomatosis it falls within a group of genetic disorders called the leukodystrophies
a cerebrovascular disease is a vascular disease of the cerebral circulation arteries supplying oxygen to the brain are affected resulting in one of a number of cerebrovascular diseases most commonly this is a stroke or mini stroke and sometimes can be a hemorrhagic stroke any of these can result in vascular dementia hypertension high blood pressure is the most important contributing cause because it damages the blood vessel lining exposing collagen where platelets aggregate to initiate a repair if maintained hypertension can change the structure of blood vessels narrow deformed blood pressure affects blood flow in narrowed vessels causing ischemic stroke a rise in blood pressure can cause tearing of vessels leading to intracranial hemorrhage a stroke usually presents with an abrupt onset of a neurologic deficit attributable to a focal vascular lesion the neurologic symptoms manifest within seconds because neurons lack glycogen so energy failure is rapid
the cerium anomaly in geochemistry is the phenomenon whereby cerium ce concentration is either depleted or enriched in a rock relative to the other rare earth elements rees a ce anomaly is said to be negative if ce is depleted relative to the other rees and is said to be positive if ce is enriched relative to the other rees cerium is a rare earth element lanthanide characterized by two different redox states iii and iv contrary to other lanthanide elements which are only trivalent with the notable exception of eu 2 ce 3 can be oxidized by atmospheric oxygen o 2 to ce 4 under alkaline conditions the cerium anomaly relates to the decrease in solubility which accompanies the oxidation of ce iii to ce iv under reducing conditions ce 3 is relatively soluble while under oxidizing conditions ceo 2 precipitates sediments deposited under oxic or anoxic conditions can preserve on the long term the geochemical signature of ce 3 or ce 4 upon reserve that no early diagenetic transformation altered it cerium can occur in nature as a 3 or 4 ion and is a compatible element at 4 valency in zircon and less commonly in silica thomas et al 2003 state that “ terrestrial zircons commonly show a positive ce anomaly due to the incorporation of ce 4 into zircon which is because ce 4 has the same charge and a similar ionic radius than zr 4 ce 4 0 97 å zr 4 0 84 å ” as such ce 4 is incorporated into zircon much easier than the larger ce 3 ionic radius 1 143 å this shows that both ce 3 and ce 4 are present and that the ce 4 being compatible in zircon is causing the anomaly
ceruminous adenocarcinoma is a malignant neoplasm derived from ceruminous glands of the external auditory canal this tumor is rare with several names used in the past synonyms have included cylindroma ceruminoma ceruminous adenocarcinoma not otherwise specified nos ceruminous adenoid cystic carcinoma acc and ceruminous mucoepidermoid carcinoma
a ceruminous adenoma also known as adenoma of the ceruminous gland and ceruminoma is a benign glandular neoplasm which arises from the ceruminous glands located within the external auditory canal these glands are found within the outer one third to one half of the external auditory canal more common along the posterior surface therefore the tumor develops within a very specific location
cervical agenesis is a congenital disorder of the female genital system that manifests itself in the absence of a cervix the connecting structure between the uterus and vagina milder forms of the condition in which the cervix is present but deformed and nonfunctional are known as cervical atresia or cervical dysgenesis
cervical cancer is a cancer arising from the cervix it is due to the abnormal growth of cells that have the ability to invade or spread to other parts of the body early on typically no symptoms are seen later symptoms may include abnormal vaginal bleeding pelvic pain or pain during sexual intercourse while bleeding after sex may not be serious it may also indicate the presence of cervical cancer human papillomavirus hpv infection appears to be involved in the development of more than 90 of cases most people who have had hpv infections however do not develop cervical cancer other risk factors include smoking a weak immune system birth control pills starting sex at a young age and having many sexual partners but these are less important cervical cancer typically develops from precancerous changes over 10 to 20 years about 90 of cervical cancer cases are squamous cell carcinomas 10 are adenocarcinoma and a small number are other types diagnosis is typically by cervical screening followed by a biopsy medical imaging is then done to determine whether or not the cancer has spread hpv vaccines protect against between two and seven high risk strains of this family of viruses and may prevent up to 90 of cervical cancers as a risk of cancer still exists guidelines recommend continuing regular pap smears other methods of prevention include having few or no sexual partners and the use of condoms cervical cancer screening using the pap smear or acetic acid can identify precancerous changes which when treated can prevent the development of cancer treatment of cervical cancer may consist of some combination of surgery chemotherapy and radiotherapy five year survival rates in the united states are 68 outcomes however depend very much on how early the cancer is detected worldwide cervical cancer is both the fourth most common cause of cancer and the fourth most common cause of death from cancer in women in 2012 an estimated 528 000 cases of cervical cancer occurred with 266 000 deaths this is about 8 of the total cases and total deaths from cancer about 70 of cervical cancers occur in developing countries in low income countries it is the most common cause of cancer death in developed countries the widespread use of cervical screening programs has dramatically reduced rates of cervical cancer in medical research the most famous cell line known as hela was developed from cervical cancer cells of a woman named henrietta lacks
cervical ectropion or cervical eversion is a condition in which the central endocervical columnar epithelium protrudes out through the external os of the cervix and onto the vaginal portion of the cervix undergoes squamous metaplasia and transforms to stratified squamous epithelium although not an abnormality it is indistinguishable from early cervical cancer therefore further diagnostic studies e g pap smear biopsy must be performed for a differential diagnosis
a cervical fracture commonly called a broken neck is a catastrophic fracture of any of the seven cervical vertebrae in the neck examples of common causes in humans are traffic collisions and diving into shallow water abnormal movement of neck bones or pieces of bone can cause a spinal cord injury resulting in loss of sensation paralysis or death
cervical incompetence or cervical insufficiency is a medical condition in which a pregnant woman s cervix begins to dilate widen and efface thin before her pregnancy has reached term definitions of cervical incompetence vary but one that is frequently used is the inability of the uterine cervix to retain a pregnancy in the absence of the signs and symptoms of clinical contractions or labor or both in the second trimester cervical incompetence may cause miscarriage or preterm birth during the second and third trimesters another sign of cervical incompetence is funneling at the internal orifice of the uterus which is a dilation of the cervical canal at this location in a woman with cervical incompetence dilation and effacement of the cervix may occur without pain or uterine contractions in a normal pregnancy dilation and effacement occurs in response to uterine contractions cervical incompetence occurs because of weakness of the cervix which is made to open by the growing pressure in the uterus as pregnancy progresses if the responses are not halted rupture of the membranes and birth of a premature baby can result according to statistics provided by the mayo clinic cervical incompetence is relatively rare in the united states occurring in only 1 – 2 of all pregnancies but it is thought to cause as many as 20 — 25 of miscarriages in the second trimester
cervical intraepithelial neoplasia cin also known as cervical dysplasia and cervical interstitial neoplasia is the potentially premalignant transformation and abnormal growth dysplasia of squamous cells on the surface of the cervix cin is not cancer and is usually curable most cases of cin remain stable or are eliminated by the host s immune system without intervention however a small percentage of cases progress to become cervical cancer usually cervical squamous cell carcinoma scc if left untreated the major cause of cin is chronic infection of the cervix with the sexually transmitted human papillomavirus hpv especially the high risk hpv types 16 or 18 over 100 types of hpv have been identified about a dozen of these types appear to cause cervical dysplasia and may lead to the development of cervical cancer other types cause warts the earliest microscopic change corresponding to cin is dysplasia of the epithelial or surface lining of the cervix which is essentially undetectable by the woman cellular changes associated with hpv infection such as koilocytes are also commonly seen in cin cin is usually discovered by a screening test the papanicolau or pap smear the purpose of this test is to detect potentially precancerous changes pap smear results may be reported using the bethesda system an abnormal pap smear result may lead to a recommendation for colposcopy of the cervix during which the cervix is examined under magnification a biopsy is taken of any abnormal appearing areas cervical dysplasia can be diagnosed by biopsy
a cervical polyp is a common benign polyp or tumour on the surface of the cervical canal they can cause irregular menstrual bleeding but often show no symptoms treatment consists of simple removal of the polyp and prognosis is generally good about 1 of cervical polyps will show neoplastic change which may lead to cancer they are most common in post menarche pre menopausal women who have been pregnant
a cervical pregnancy is an ectopic pregnancy that has implanted in the uterine endocervix such a pregnancy typically aborts within the first trimester however if it is implanted closer to the uterine cavity a so called cervico isthmic pregnancy it may continue longer placental removal in a cervical pregnancy may result in major hemorrhage
a cervical rib in humans is an extra rib which arises from the seventh cervical vertebra sometimes known as neck ribs their presence is a congenital abnormality located above the normal first rib a cervical rib is estimated to occur in 0 6 1 in 150 people to 0 8 of the population people may have a cervical rib on the right left or both sides most cases of cervical ribs are not clinically relevant and do not have symptoms cervical ribs are generally discovered incidentally however they vary widely in size and shape and in rare cases they may cause problems such as contributing to thoracic outlet syndrome because of pressure on the nerves that may be caused by the presence of the rib a cervical rib represents a persistent ossification of the c 7 lateral costal element during early development this ossified costal element typically becomes re absorbed failure of this process results in a variably elongated transverse process or complete rib that can be anteriorly fused with the t 1 first rib below on imaging cervical ribs can be distinguished because their transverse processes are directed inferolaterally whereas those of the adjacent thoracic spine are directed anterolaterally
cervical spinal stenosis is a bone disease involving the narrowing of the spinal canal at the level of the neck it is frequently due to chronic degeneration but may also be congenital treatment is frequently surgical
cervical spine disorders are illnesses that affect the cervical spine which is made up of the upper first seven vertebrae encasing and shielding the spinal cord this fragment of the spine starts from the region above the shoulder blades and ends by supporting and connecting the skull the cervical spine contains many different anatomic compositions including muscles bones ligaments and joints all of these structures have nerve endings that can detect painful problems when they occur such nerves supply muscular control and sensations to the skull and arms while correspondingly providing our bodies with flexibility and motion 1 however if the cervical spine is injured it can cause many minor or traumatic problems and although these injuries vary specifically they are more commonly known as cervical spine disorders as a whole 1
cervicitis is inflammation of the uterine cervix cervicitis in women has many features in common with urethritis in men and many cases are caused by sexually transmitted infections death may occur non infectious causes of cervicitis can include intrauterine devices contraceptive diaphragms and allergic reactions to spermicides or latex condoms the condition is often confused with vaginismus which is a much simpler condition and easily rectified with simple exercises
cervicogenic headache is a type of headache characterised by chronic hemicranial pain referred to the head from either the cervical spine or soft tissues within the neck
cetacean stranding is a phenomenon in which cetaceans strand themselves on land usually on a beach beached whales often die due to dehydration collapsing under their own weight or drowning when high tide covers the blowhole several explanations of the stranding have been proposed
chafing refers to the irritation of skin caused by repetitive friction usually generated through skin to skin contact of multiple body parts chafing is usually contracted in the inner thighs and inner glutes armpits and nipples can also develop chafing although it is less common
chagas disease also known as american trypanosomiasis is a tropical parasitic disease caused by the protozoan trypanosoma cruzi it is spread mostly by insects known as triatominae or kissing bugs the symptoms change over the course of the infection in the early stage symptoms are typically either not present or mild and may include fever swollen lymph nodes headaches or local swelling at the site of the bite after 8 – 12 weeks individuals enter the chronic phase of disease and in 60 – 70 it never produces further symptoms the other 30 to 40 of people develop further symptoms 10 to 30 years after the initial infection including enlargement of the ventricles of the heart in 20 to 30 leading to heart failure an enlarged esophagus or an enlarged colon may also occur in 10 of people t cruzi is commonly spread to humans and other mammals by the blood sucking kissing bugs of the subfamily triatominae these insects are known by a number of local names including vinchuca in argentina bolivia chile and paraguay barbeiro the barber in brazil pito in colombia chinche in central america and chipo in venezuela the disease may also be spread through blood transfusion organ transplantation eating food contaminated with the parasites and by vertical transmission from a mother to her fetus diagnosis of early disease is by finding the parasite in the blood using a microscope chronic disease is diagnosed by finding antibodies for t cruzi in the blood prevention mostly involves eliminating kissing bugs and avoiding their bites other preventative efforts include screening blood used for transfusions a vaccine has not been developed as of 2013 early infections are treatable with the medication benznidazole or nifurtimox medication nearly always results in a cure if given early but becomes less effective the longer a person has had chagas disease when used in chronic disease medication may delay or prevent the development of end – stage symptoms benznidazole and nifurtimox cause temporary side effects in up to 40 of people including skin disorders brain toxicity and digestive system irritation it is estimated that 7 to 8 million people mostly in mexico central america and south america have chagas disease as of 2013 in 2006 chagas was estimated to result in 12 500 deaths per year most people with the disease are poor and most people with the disease do not realize they are infected large scale population movements have increased the areas where chagas disease is found and these include many european countries and the united states these areas have also seen an increase in the years up to 2014 the disease was first described in 1909 by carlos chagas after whom it is named it affects more than 150 other animals
a chagoma is an inflammatory nodule at the bite site of the reduviid bug which transmits chagas disease not to be confused with romana s sign which is periorbital soft tissue and lymphoid swelling which occurs when the t cruzi protozoan that causes chagas disease enters through the conjunctiva
in object oriented design the chain of responsibility pattern is a design pattern consisting of a source of command objects and a series of processing objects each processing object contains logic that defines the types of command objects that it can handle the rest are passed to the next processing object in the chain a mechanism also exists for adding new processing objects to the end of this chain in a variation of the standard chain of responsibility model some handlers may act as dispatchers capable of sending commands out in a variety of directions forming a tree of responsibility in some cases this can occur recursively with processing objects calling higher up processing objects with commands that attempt to solve some smaller part of the problem in this case recursion continues until the command is processed or the entire tree has been explored an xml interpreter might work in this manner this pattern promotes the idea of loose coupling
in phonology a chain shift is a phenomenon in which several sounds move stepwise along a phonetic scale the sounds involved in a chain shift can be ordered into a chain in such a way that after the change is complete each phoneme ends up sounding like what the phoneme before it in the chain sounded like before the change the rules making up a chain shift are said to be in counterfeeding order for example if in some language the three vowel phonemes æ ɛ e undergo a change so they became respectively ɛ e i those three changes would constitute a chain shift and could be summarized as æ → ɛ → e → i a drag chain or pull chain is a chain shift in which the phoneme at the leading edge of the chain changes first in this example the chain shift would be a pull chain if e changed to i first opening up a space at the position of e which ɛ then moved to fill a push chain is a chain shift in which the phoneme at the end of the chain moves first in this example if æ moved toward ɛ creating a crowding effect and causing ɛ to move toward e and so forth
chain transfer is a polymerization reaction by which the activity of a growing polymer chain is transferred to another molecule p • xr → px r • chain transfer reactions reduce the average molecular weight of the final polymer chain transfer can be either introduced deliberately into a polymerization by use of a chain transfer agent or it may be an unavoidable side reaction with various components of the polymerization chain transfer reactions occur in most forms of addition polymerization including radical polymerization ring opening polymerization coordination polymerization and cationic as well as anionic addition polymerization iupac definitions chain transfer in a chain polymerization chemical reaction occurringduring a chain polymerization in which an active center is transferredfrom a growing macromolecule or oligomer molecule to another moleculeor to another site on the same molecule chain transfer agent substance able to react with a chain carrier by areaction in which the original chain carrier is deactivated and a new chaincarrier is generated chain transfer reactions are usually categorized by the nature of the molecule that reacts with the growing chain transfer to chain transfer agent chain transfer agents have at least one weak chemical bond which therefore facilitates the chain transfer reaction common chain transfer agents include thiols especially ddm and halocarbons such as carbon tetrachloride chain transfer agents are sometimes called modifiers or regulators transfer to monomer chain transfer to monomer may take place in which the growing polymer chain abstracts an atom from unreacted monomer existing in the reaction medium because by definition polymerization reactions only take place in the presence of monomer chain transfer to monomer determines the theoretical maximum molecular weight that can be achieved by a given monomer chain transfer to monomer is especially significant in cationic addition polymerization and ring opening polymerization transfer to polymer chain transfer may take place with an already existing polymer chain especially under conditions in which much polymer is present this often occurs at the end of a radical polymerization when almost all monomer has been consumed branched polymers are formed as monomer adds to the new radical site which is located along the polymer backbone the properties of low density polyethylene are critically determined by the amount of chain transfer to polymer that takes place transfer to solvent in solution polymerization the solvent can act as a chain transfer agent unless the solvent is chosen to be inert very low molecular weight polymers oligomers can result
chalazion is a cyst in the eyelid due to a blocked oil gland they are typically in the middle of the eyelid red and non painful they tend to come on gradually over a few weeks a chalazion may occur following a stye or from hardened oils blocking the gland the blocked gland is usually the meibomian gland but can also be the gland of zeis a stye and cellulitis may appear similar a stye however is usually more sudden in onset painful and occurs at the edge of the eyelid cellulitis is also typically painful treatment is typically initially with warm compresses if this is not effective injecting steroids into the lesion maybe tried if large incision and drainage maybe recommended while relatively common the frequency of the condition is unknown the term is from the greek khalazion meaning small hailstone
chalicosis greek χάλιξ gravel sometimes called flint disease is a form of pneumoconiosis affecting the lungs or bronchioles found chiefly among stonecutters the disease is caused by the inhalation of fine particles of stone
chamber pressure firearms is the pressure exerted by a cartridge case s outside walls on the inside of a firearm s chamber when the cartridge is fired it is generally expressed in psi pounds per square inch or copper units of pressure
a chameleon oil pattern is a pattern of oil on a bowling lane it is used by the professional bowlers association in tournament play among others a typical chameleon pattern is 43 feet long it forces players to play in a specific zone on the lane because of the way the oil is layered in strips the lane conditions dictate where the bowler should play this is considered a retro approach to pattern designing use of a chameleon pattern results in a large range of scores low to high as does the bowlers approach to the pattern no one bowling style is most effective on this type of lane because there can be multiple starting points that dictate how much the ball will spin and thus how much curvature its path will have this oil pattern is named after the chameleon because like a chameleon which can change its color repeatedly so too must a bowler be able to change his style of play
the chan – lam coupling reaction – also known as the chan – evans – lam coupling as chan evans and lam published their work back to back in tetrahedron letters – is a cross coupling reaction between an aryl boronic acid and an alcohol or an amine to form the corresponding secondary aryl amines or aryl ethers respectively the chan – lam coupling is catalyzed in the presence of copper ii species and may be conducted in air at room temperature this is in contrast to the buchwald – hartwig coupling which relies on the use of expensive noble metal catalysts palladium non generalizable ligands and a basic species for deprotonation of the n h and o h bonds in this regard the chan – lam coupling has several benefits over other c n and c o coupling reactions because motifs containing aryl c n and c o bonds are frequently found in pharmaceuticals the chan – lam coupling has seen a great deal of application often stoichiometric copper is used as only a small amount of the copper proceeds to a catalytically active species the mechanism which is still rather controversial is shown in the below figure chan – lam coupling it is presently unknown whether the chan lam coupling proceeds through a copper ii to copper 0 catalytic cycle or if it proceeds through a copper ii copper iii copper i process and then in the presence of ambient air oxygen if this copper i species is then recycled to copper 0 restarting the cycle nevertheless the catalytic cycle is characterized by de facto i ligand exchange ii transmetallation iii reductive elimination and iv oxidation a recent example of the chan – lam coupling to synthesize biologically active compounds is shown below reaction example of chan – lam coupling compound 1 a pyrrolic amine is coupled with aryl boronic ester 2 to afford product 3 which is then carried forward to the biologically active target 4 the nitrile group of 2 does not poison the cu oac 2 used and pyridine is the ligand used for the reaction though the reaction is characterized by a lengthy duration three days it was carried out at room temperature in ambient air and resulted in a net 93 yield
the chan rearrangement is a chemical reaction that involves rearranging an acyloxy acetate 1 in the presence of a strong base to a 2 hydroxy 3 keto ester 2 the chan rearrangement this procedure was rediscovered and employed in the holton taxol total synthesis
a chance fracture is a flexion injury of the spine first described by g q chance in 1948 it consists of a compression injury to the anterior portion of the vertebral body and a transverse fracture through the posterior elements of the vertebra and the posterior portion of the vertebral body it is caused by violent forward flexion causing distraction injury to the posterior elements the most common site at which chance fractures occur is the thoracolumbar junction t 12 l 2 and midlumbar region in pediatric population this fracture initially became known as a seat belt injury due to its association with the sudden forward flexion that occurs when one is involved in a head on automobile collision while being restrained by a lap belt with the advent of both lap and shoulder belts in the 1980 s chance fractures have become less common especially now that lap belt only seat belts have been almost entirely phased out up to 50 of chance fractures have associated intraabdominal injuries injuries associated with chance fractures include contusions and or lacerations of the pancreas duodenum and mesentery
a chancre ˈʃæŋkər shang kər is a painless ulceration sore most commonly formed during the primary stage of syphilis this infectious lesion forms approximately 21 days after the initial exposure to treponema pallidum the gram negative spirochaete bacterium yielding syphilis chancres transmit the sexually transmissible disease of syphilis through direct physical contact these ulcers usually form on or around the anus mouth penis and vagina chancres may diminish between four and eight weeks without the application of medication chancres as well as being painless ulcerations formed during the primary stage of syphilis are associated with the african trypanosomiasis sleeping sickness surrounding the area of the tsetse fly bite
chancroid also known as soft chancre and ulcus molle is a bacterial sexually transmitted infection characterized by painful sores on the genitalia chancroid is known to spread from one individual to another solely through sexual contact
chandler s disease also called osteochondritis dissecans is a rare condition in which spontaneous osteonecrosis of the femoral head in an adult is analogous to legg calve perthes syndrome in children this disease is caused when blood flow is reduced to the part of a bone near a joint
change blindness is a perceptual phenomenon that occurs when a change in a visual stimulus is introduced and the observer does not notice it for example observers often fail to notice major differences introduced into an image while it flickers off and on again people s poor ability to detect changes has been argued to reflect fundamental limitations of human attention change blindness has become a highly researched topic and some have argued that it may have important practical implications in areas such as eyewitness testimony and distractions while driving
change deafness is a perceptual phenomenon that occurs when under certain circumstances a physical change in an auditory stimulus goes unnoticed by the listener there is uncertainty regarding the mechanisms by which changes to auditory stimuli go undetected though scientific research has been done to determine the levels of processing at which these consciously undetected auditory changes are actually encoded an understanding of the mechanisms underlying change deafness could offer insight on issues such as the completeness of our representation of the auditory environment the limitations of the auditory perceptual system and the relationship between the audtitory system and memory the phenomenon of change deafness is thought to be related to the interactions between high and low level processes that produce conscious experiences of auditory soundscapes
channel iron deposits cid are iron rich fluvial sedimentary deposits of possible miocene age occupying meandering palaeochannels in the early to mid cenozoic hamerlsey palaeosurface of western australia examples are also known from kazakhstan the deposits are anomalously high in iron for deterital material and exclude detrital iron deposits typified by scree of hematitic banded iron formations and accumulations of currently forming maghemite pisolite alluvials cids are a major source of cheap high grade iron ore exploited primarily in the pilbara and murchison regions of western australia
one of several short channel effects in mosfet scaling channel length modulation clm is a shortening of the length of the inverted channel region with increase in drain bias for large drain biases the result of clm is an increase in current with drain bias and a reduction of output resistance channel length modulation occurs in all field effect transistors not just mosfets to understand the effect first the notion of pinch off of the channel is introduced the channel is formed by attraction of carriers to the gate and the current drawn through the channel is nearly a constant independent of drain voltage in saturation mode however near the drain the gate and drain jointly determine the electric field pattern instead of flowing in a channel beyond the pinch off point the carriers flow in a subsurface pattern made possible because the drain and the gate both control the current in the figure at the right the channel is indicated by a dashed line and becomes weaker as the drain is approached leaving a gap of uninverted silicon between the end of the formed inversion layer and the drain the pinch off region as the drain voltage increases its control over the current extends further toward the source so the uninverted region expands toward the source shortening the length of the channel region the effect called channel length modulation because resistance is proportional to length shortening the channel decreases its resistance causing an increase in current with increase in drain bias for a mosfet operating in saturation the effect is more pronounced the shorter the source to drain separation the deeper the drain junction and the thicker the oxide insulator in the weak inversion region the influence of the drain analogous to channel length modulation leads to poorer device turn off behavior known as drain induced barrier lowering a drain induced lowering of threshold voltage in bipolar devices a similar increase in current is seen with increased collector voltage due to base narrowing known as the early effect the similarity in effect upon the current has led to use of the term early effect for mosfets as well as an alternative name for channel length modulation
channelopathies are diseases caused by disturbed function of ion channel subunits or the proteins that regulate them these diseases may be either congenital often resulting from a mutation or mutations in the encoding genes or acquired often resulting from autoimmune attack on an ion channel there are a large number of distinct dysfunctions known to be caused by ion channel mutations the genes for the construction of ion channels are highly conserved amongst mammals and one condition hyperkalemic periodic paralysis was first identified in the descendants of impressive a registered quarter horse see aqha website the channelopathies of human skeletal muscle include hyper and hypokalemic high and low potassium blood concentrations periodic paralysis myotonia congenita and paramyotonia congenita channelopathies affecting synaptic function are a type of synaptopathy
chaos days german chaostage was an annual punk manifestation often violent held in hanover germany starting in 1982 and reviving in the mid 1990 s chaos tage was a west german punk scene phenomenon which began in the mid 1980 s in hanover and wuppertal and consisted of meetings of punks from all over the country the reason for these meetings were a plan of the police to register and build up reference data of everyone who was deemed a punk this included taking pictures of each individual the most well known chaos days took place in hanover in 1994 and 1995 and resulted in huge riots and the destruction of cars and buildings a whole supermarket was damaged and alcoholic beverages were stolen by punks these chaos days were the main topic of tv debates and newspapers for several weeks popular bands like wizo spontaneously played a show there and terrorgruppe wrote a now classic song about it wochenendticket named after a train ticket that most punks used in order to get to hanover from all across the country chaos days usachaos days were organized in the united states in 1995 and 1996 to be held in the san francisco bay area during the same period of time as the german chaos days chaos days usa were criticized for the same reasons as the german chaos days critics claimed that chaos days had no social value
in mathematics particularly in the fields of nonlinear dynamics and the calculus of variations the chaplygin problem is an isoperimetric problem with a differential constraint specifically the problem is to determine what flight path an airplane in a constant wind field should take in order to encircle the maximum possible area the airplane is assumed to be constrained to move in a plane moving at a constant airspeed v and the wind is assumed to move in a constant direction with speed w the solution of the problem is that the airplane should travel in an ellipse whose eccentricity is w v
character amnesia is a phenomenon whereby experienced speakers of some east asian languages forget how to write chinese characters previously well known to them the phenomenon is specifically tied to prolonged and extensive use of input methods such as those that use romanizations of characters and is documented to be a significant issue in china and japan modern technology such as mobile phones and computers allows users to enter chinese characters using their phonetic transcription without knowing how to write them by hand whether or not the phenomenon is as widespread or troubling as some have claimed is the subject of debate
in mathematics more specifically in group theory the character of a group representation is a function on the group that associates to each group element the trace of the corresponding matrix the character carries the essential information about the representation in a more condensed form georg frobenius initially developed representation theory of finite groups entirely based on the characters and without any explicit matrix realization of representations themselves this is possible because a complex representation of a finite group is determined up to isomorphism by its character the situation with representations over a field of positive characteristic so called modular representations is more delicate but richard brauer developed a powerful theory of characters in this case as well many deep theorems on the structure of finite groups use characters of modular representations
in the field of mathematics known as convex analysis the characteristic function of a set is a convex function that indicates the membership or non membership of a given element in that set it is similar to the usual indicator function and one can freely convert between the two but the characteristic function as defined below is better suited to the methods of convex analysis
dyslexia is a disorder characterised by problems with the visual notation of speech which in most languages of european origin are problems with alphabet writing systems which have a phonetic construction examples of these issues can be problems speaking in full sentences problems correctly articulating rs and ls as well as ms and ns mixing up sounds in multi syllabic words ex aminal for animal bisghetti for spaghetti hekalopter for helicopter hangaberg for hamburger ageen for magazine etc problems of immature speech wed and gween instead of red and green the characteristics of dyslexia have been identified mainly from research in languages with alphabetic writing systems primarily english however many of these characteristic may be transferable to other types of writing systems the causes of dyslexia are not agreed upon although the consensus of neuroscientists believe dyslexia is a phonological processing disorder and that dyslexics have reading difficulties because they are unable to see or hear a word break it down to discrete sounds and then associate each sound with letter s that make up the word some researchers believe that a subset of dyslexics have visual deficits in addition to deficits in phoneme processing but this view is not universally accepted in any case there s no evidence that dyslexics literally see letters backward or in reverse order within words
charcot – marie – tooth disease cmt is one of the hereditary motor and sensory neuropathies a group of varied inherited disorders of the peripheral nervous system characterised by progressive loss of muscle tissue and touch sensation across various parts of the body currently incurable this disease is the most commonly inherited neurological disorder and affects approximately 1 in 2 500 people cmt was previously classified as a subtype of muscular dystrophy
in digital electronics charge sharing is an undesirable signal integrity phenomenon observed most commonly in the domino logic family of digital circuits the charge sharing problem occurs when the charge which is stored at the output node in the phase is shared among the output or junction capacitances of transistors which are in the evaluation phase charge sharing may degrade the output voltage level or even cause erroneous output value
charley horse is a popular colloquial term in canada and the united states for painful involuntary spasms or cramps in the leg muscles typically lasting anywhere from a few seconds to about a day it is less likely to refer to a bruise on an arm or leg and a bruising of the quadriceps muscle of the anterior or lateral thigh or contusion of the femur that commonly results in a haematoma and sometimes several weeks of pain and disability in this latter sense such an injury is known as dead leg in australia it is also known as a corked thigh or corky it often occurs in contact sports such as football when an athlete suffers a knee blunt trauma to the lateral quadriceps causing a haematoma or temporary paresis and antalgic gait as a result of pain another term jolly horse is used to describe simple painful muscle cramps in the leg or foot especially those that follow strenuous exercise the term can also be used to refer to cramps in the foot muscles these muscle cramps can have many possible causes directly resulting from high or low ph or substrate concentrations in the blood including hormonal imbalances dehydration low levels of magnesium potassium or calcium although the evidence has been mixed side effects of medication or more seriously diseases such as amyotrophic lateral sclerosis and neuropathy they are also a common complaint during pregnancy
a chart pattern or price pattern is a pattern within a chart when prices are graphed in stock and commodity markets trading chart pattern studies play a large role during technical analysis when data is plotted there is usually a pattern which naturally occurs and repeats over a period chart patterns are used as either reversal or continuation signals
the effect can be likened to the sheen off a spool of silk the luminous streak of reflected light is always perpendicular to the direction of the fibres for a gemstone to show this effect best it must be cut en cabochon with the fibers or fibrous structures parallel to the base of the finished gem the best finished specimens show a single sharply defined band of light that moves across the stone when it is rotated chatoyant stones of lesser quality display a banded effect as is typical with cat s eye varieties of quartz faceted stones do not show the effect well gem species known for this phenomenon include the aforementioned quartz chrysoberyl beryl especially var aquamarine charoite tourmaline labradorite selenite feldspar apatite moonstone thomsonite and scapolite amongst others glass optical cable can also display chatoyancy if properly cut and has become a popular decorative material in a variety of vivid colors the term cat s eye when used by itself as the name of a gemstone refers to a cat s eye chrysoberyl it is also used as an adjective which indicates the chatoyance phenomenon in another stone e g cat s eye aquamarine
chauffeur s fracture is a type of fracture of the forearm specifically the radial styloid process the injury is typically caused by compression of the scaphoid bone of the hand against the styloid process of the distal radius it can be caused by falling onto an outstretched hand foosh treatment is often open reduction and internal fixation which is surgical realignment of the bone fragments and fixation with pins screws or plates the name originates from early chauffeurs who sustained these injuries when the car back fired while the chauffeur was hand cranking to start the car the back fire forced the crank backward into the chauffeur s palm and produced the characteristic styloid fracture it is also known as a backfire fracture for the same reason or a hutchinson fracture
in number theory chebyshev s bias is the phenomenon that most of the time there are more primes of the form 4 k 3 than of the form 4 k 1 up to the same limit this phenomenon was first observed by chebyshev in 1853
a check is a condition in chess shogi and xiangqi that occurs when a player s king or general in xiangqi is under threat of capture on their opponent s next turn a king so threatened is said to be in check a player must get out of check if possible by interposing a piece between the threatening piece and the king capturing the threatening piece or moving the king to a square where it is no longer in check if the player cannot move out of check the game ends in checkmate and the player loses players cannot make any move that puts their own king in check
a check also checker brit chequer is a pattern of modified stripes consisting of crossed horizontal and vertical lines forming squares
in fluid mechanics the cheerios effect is the phenomenon that occurs when floating objects that don t normally float attract one another wetting an example of the cheerios effect is when breakfast cereal clumps together or clings to the sides of a bowl of milk it is named after the common breakfast cereal cheerios and is due to surface tension the same effect governs the behavior of bubbles on the surface of soft drinks
cheilitis is inflammation of the lips this inflammation may include the perioral skin the skin around the mouth the vermilion border and or the labial mucosa the skin and the vermilion border are more commonly involved as the mucosa is less affected by inflammatory and allergic reactions it is a general term and there are many recognized types and different causes cheilitis can be either acute or chronic most cheilitis is caused by exogenous factors such as dryness chapping and acute sun exposure patch testing may identify allergens that cause cheilitis
cheiralgia paraesthetica is a neuropathy of the hand generally caused by compression or trauma to the superficial branch of the radial nerve the area affected is typically on the back or side of the hand at the base of the thumb near the anatomical snuffbox but may extend up the back of the thumb and index finger and across the back of the hand symptoms include numbness tingling burning or pain since the nerve branch is sensory there is no motor impairment it may be distinguished from de quervain syndrome because it is not dependent on motion of the hand or fingers the most common cause is thought to be constriction of the wrist as with a bracelet or watchband hence reference to wristwatch neuropathy it is especially associated with the use of handcuffs and is therefore commonly referred to as handcuff neuropathy other injuries or surgery in the wrist area can also lead to symptoms including surgery for other syndromes such as de quervain s the exact etiology is unknown as it is unclear whether direct pressure by the constricting item is alone responsible or whether edema associated with the constriction also contributes symptoms commonly resolve on their own within several months when the constriction is removed nsaids are commonly prescribed in some cases surgical decompression is required the efficacy of cortisone and laser treatment is disputed permanent damage is possible this neuropathy was first identified by robert wartenberg in a 1932 paper recent studies have focused on handcuff injuries due to the legal liability implications but these have been hampered by difficulties in followup particularly as large percentages of the study participants have been inebriated when they were injured diagnostically it is often subsumed into compression neuropathy of the radial nerve as a whole e g icd 9 354 3 but studies and papers continue to use the older term to distinguish it from more extensive neuropathies originating in the forearm
cheletropic reactions also known as chelotropic reactions are a type of pericyclic reaction a pericyclic reaction is one that involves a transition state with a cyclic array of atoms and an associated cyclic array of interacting orbitals a reorganization of σ and π bonds occurs in this cyclic array specifically cheletropic reactions are a subclass of cycloadditions the key distinguishing feature of cheletropic reactions is that on one of the reagents both new bonds are being made to the same atom a few examples are shown to the right in the first case the single atom is the carbonyl carbon that ends up in carbon monoxide the end result is making two new bonds to one atom the first two examples are known as cheletropic extrusions because a small stable molecule is given off in the reaction the driving force for these reactions is often the entropic benefit of gaseous evolution e g co or n 2
chelonitoxism is a type of food poisoning from eating marine turtles it is considered rare hawksbill turtle meat is one source of the biotoxin as well as green sea turtle chelonia mydas chelontoxism can be deadly and there is no known antidote sea turtle is a traditional food in the outer micronesian islands symptoms include nausea vomiting dysphagia and abdominal pain severe cases can induce coma and multiorgan problems children are especially susceptible and the toxins have been reported to transfer via breastfeeding
a chemical burn occurs when living tissue is exposed to a corrosive substance such as a strong acid or base chemical burns follow standard burn classification and may cause extensive tissue damage the main types of irritant and or corrosive products are acids bases oxidizers reducing agents solvents and alkylants additionally chemical burns can be caused by some types of chemical weapons e g vesicants such as mustard gas and lewisite or urticants such as phosgene oxime chemical burns may need no source of heat occur immediately on contact not be immediately evident or noticeable be extremely painful diffuse into tissue and damage structures under skin without immediately apparent damage to skin surface
the chemical chameleon is a redox reaction well known from classroom demonstrations that exploits the dramatic color changes associated with the various oxidation states of manganese glauber reported the first description of the production of potassium permanganate when he noted that manganese dioxide as the mineral pyrolusite could be reacted at high temperatures with alkali to obtain a material that dissolved in water to give a green solution which slowly shifted to a violet red this process similar to that still used in the production of potassium permanganate oxidized manganese dioxide to potassium manganate which acidified by carbon dioxide absorbed from the air oxidized further to purple potassium permanganate the chemical chameleon reaction shows the process in reverse by reducing violet potassium permanganate first to green potassium manganate and eventually to brown manganese dioxide kmno 4 violet → k 2 mno 4 green → mno 2 brown yellow suspension blue potassium hypomanganate may also form as an intermediate the reaction proceeds in alkaline conditions under the influence of a reducing agent sodium hydroxide potassium hydroxide and ammonium hydroxide can be used to alkalize the permanganate solution while a variety of reducing agents can be used sugars being common a similar demonstration involves soaking paper in alkalized permanganate solution which produces the same color changes as the paper is oxidized and the permanganate reduced
chemical colitis is a type of colitis an inflammation of the large intestine or colon caused by the introduction of harsh chemicals to the colon by an enema or other procedure chemical colitis can resemble ulcerative colitis infectious colitis and pseudomembranous colitis endoscopically prior to 1950 hydrogen peroxide enemas were commonly used for certain conditions this practice will often result in chemical colitis soap enemas may also cause chemical colitis harsh chemicals such as compounds used to clean colonoscopes are sometimes accidentally introduced into the colon during colonoscopy or other procedures this can also lead to chemical colitis chemical colitis may trigger a flare of ulcerative colitis or crohn s colitis symptoms of colitis are assessed using the simple clinical colitis activity index
chemical decomposition analysis or breakdown is the separation of a chemical compound into elements or simpler compounds it is sometimes defined as the exact opposite of a chemical synthesis chemical decomposition is often an undesired chemical reaction the stability that a chemical compound ordinarily has is eventually limited when exposed to extreme environmental conditions like heat radiation humidity or the acidity of a solvent the details of decomposition processes are generally not well defined as a molecule may break up into a host of smaller fragments chemical decomposition is exploited in several analytical techniques notably mass spectrometry traditional gravimetric analysis and thermogravimetric analysis a broader definition of the term decomposition also includes the breakdown of one phase into two or more phases there are three broad types of decomposition reactions thermal electrolytic and catalytic
aspiration pneumonitis or chemical pneumonitis is inflammation of the lung caused by aspirating or inhaling irritants it is sometimes called a chemical pneumonia though it is not infectious there are two general types of chemical pneumonitis acute and chronic irritants capable of causing chemical pneumonitis include vomitus barium used in gastro intestinal imaging chlorine gas among other pulmonary agents ingested gasoline or other petroleum distillates ingested or skin absorbed pesticides gases from electroplating smoke and others it may also be caused by the use of inhalants mendelson s syndrome is a type of chemical pneumonitis mineral oil should not be given internally to young children pets or anyone with a cough hiatus hernia or nocturnal reflux because it can cause complications such as lipoid pneumonia due to its low density it is easily aspirated into the lungs where it cannot be removed by the body in children if aspirated the oil can work to prevent normal breathing resulting in death of brain cells and permanent paralysis and or retardation signs and symptoms of chemical pneumonitis include acute cough difficulty breathing abnormal lung sounds wet gurgling sounding breaths chest pain tightness or burning chronic persistent cough shortness of breath increased susceptibility to respiratory illness symptoms of chronic chemical pneumonitis may or may not be present and can take months or years to develop to the point of noticeability
chemical specificity is the ability of a protein s binding site to bind specific ligands the fewer ligands a protein can bind the greater its specificity specificity describes the strength of binding between a given protein and ligand this relationship can be described by a dissociation constant which characterizes the balance between bound and unbound states for the protein ligand system in the context of a single enzyme and a pair of binding molecules the two ligands can be compared as stronger or weaker ligands for the enzyme on the basis of their dissociation constants a lower value corresponds to a stronger binding specificity for a set of ligands is unrelated to the ability of an enzyme to catalyze a given reaction with the ligand as a substrate if a given enzyme has a high chemical specificity this means that the set of ligands to which it binds is limited such that neither binding events nor catalysis can occur at an appreciable rate with additional molecules an example of a protein ligand pair whose binding activity can be described as highly specific is the antibody antigen system conversely an example of a protein ligand system that can bind substrates and catalyze multiple reactions effectively is the cytochrome p 450 system which can be considered a promiscuous enzyme due to its broad specificity for multiple ligands
the chemical traffic light is the reaction of the changing in color of the solution which also related to the blue bottle experiment one of the early formula consists of glucose sodium hydroxide indigo carmine and water another formula consists of indigo carmine dye ascorbic acid vitamin c sodium bicarbonate sodium chloride copper ii sulfate sodium hydroxide and water by doing so chemical waste and the level of corrosive is reduced the amount of solid chemicals dissolved in the experiment could be reduced from 60 grams to 6 grams and the ph could be lowered from 13 to 3 which is easier to neutralize the ph to 7 by adding baking soda before disposal also it is safer and the reactions also occur faster and are easier to perform at first all chemicals are added together and the color appears yellow after shaking the color turns green and then changes to red after it is left untouched when further observed the color turns back to yellow which is why the solution is called the chemical traffic light this reaction can be repeated many times but it needs additional oxygen or indigo carmine
chemotherapy induced acral erythema also known as palmar plantar erythrodysesthesia palmoplantar erythrodysesthesia or hand foot syndrome is reddening swelling numbness and desquamation skin sloughing or peeling on palms of the hands and soles of the feet and occasionally on the knees elbows and elsewhere that can occur after chemotherapy in patients with cancer hand foot syndrome is also rarely seen in sickle cell disease these skin changes usually are well demarcated acral erythema typically disappears within a few weeks after discontinuation of the offending drug
chemotherapy induced hyperpigmentation is caused by many chemotherapeutic agents especially the antibiotics bleomycin and daunorubicin and the alkylating agents cyclophosphamide and busulfan
chemo tropism is the growth of organisms or parts of an organism including individual cells such as bacteria and plants navigated by chemical stimulus from outside of the organism or organisms part the response of the organism or organism part is termed ‘ positive ’ if the growth is towards the stimulus or ‘ negative ’ if the growth is away from the stimulus an example of chemo tropic movement can be seen during the growth of the pollen tube where growth is always towards the ovules it can be also written that conversion of flower into fruit is the example of chemo tropism fertilization of flowers by pollen is achieved because the ovary releases chemicals that produce a positive chemo tropic response from the developing pollen tube an example of positive and negative chemo tropism is shown by a plant ’ s roots the roots grow towards useful minerals displaying positive chemo tropism and grow away from harmful acids displaying negative chemo tropism another example of chemo tropic movement of includes the growth of individual neuronal cell axons in response to extra cellular signals which guide the developing axon to innervate the correct target tissue also the addition of atmospheric nitrogen also called nitrogen fixation is an example of chemo tropism chemo tropism is different from chemotaxis the major difference being that chemo tropism is related to growth while chemotaxis is related to locomotion
cherry eye is a disorder of the nictitating membrane nm also called the third eyelid present in the eyes of dogs and cats cherry eye is most often seen in young dogs under the age of two common misnomers include adenitis hyperplasia adenoma of the gland of the third eyelid however cherry eye is not caused by hyperplasia neoplasia or primary inflammation in many species the third eyelid plays an essential role in vision by supplying oxygen and nutrients to the eye via tear production normally the gland can evert without detachment cherry eye results from a defect in the retinaculum which is responsible for anchoring the gland to the periorbita this defect causes the gland to prolapse and protrude from the eye as a red fleshy mass problems arise as sensitive tissue dries out and is subjected to external trauma exposure of the tissue often results in secondary inflammation swelling or infection if left untreated this condition can lead to keratoconjunctivitis sicca kcs and other complications
cherry angiomas also known as campbell de morgan spots or senile angiomas are cherry red papules on the skin containing an abnormal proliferation of blood vessels they are the most common kind of angioma they are called campbell de morgan spots after the nineteenth century british surgeon campbell de morgan who first noted and described them the frequency of cherry angiomas increases with age
cherry leaf spot is a fungal disease which infects cherries and plums sweet and sour cherries are susceptible to the disease however leaf spot is much more prevalent in sour cherries the variety of sour cherries that is the most susceptible are the english morello cherries this is considered a serious disease in the midwest new england states and canada it has also been estimated to infect 80 percent of orchards in the eastern states it must be controlled yearly to avoid a significant loss of the crop if not controlled properly the disease can dramatically reduce yields by nearly 100 percent the disease is also known as “ yellow leaf ” or “ shothole disease ” to cherry growers due to the characteristic yellowing leaves and shot holes present in the leaves upon severe infection
cherubism is a rare genetic disorder that causes prominence in the lower portion in the face the name is derived from the temporary chubby cheeked resemblance to putti often confused with cherubs in renaissance paintings
chess equipment are the tangible items required to play a game of chess to have an over the board otb chess tournament the equipment required includes chess pieces chessboard chess clock and table a chess player playing a game of online chess correspondence chess computer chess or non tournament chess may choose their own preferred configuration of chess equipment
a chest injury is any form of physical injury to the chest including the ribs heart and lungs chest injuries account for 25 of all deaths from traumatic injury typically chest injuries are caused by blunt mechanisms such as motor vehicle collisions or penetrating mechanisms such as stabbings
chest pain in children is the pain felt in the chest by infants children and adolescents in most cases the pain is not associated with the heart it is primarily identified by the observance or report of pain by the infant child or adolescent by reports of distress by parents or caregivers chest pain is not uncommon in children many children are seen in ambulatory clinics emergency departments and hospitals and cardiology clinics most often there is a benign cause for the pain for most children some have conditions that are serious and possibly life threatening chest pain in pediatric patients requires careful physical examination and a detailed history that would indicate the possibility of a serious cause studies of pediatric chest pain are sparse it has been difficult to create evidence based guidelines for evaluation
chevron nail also known as a herringbone nail is a rare transient fingernail ridge pattern seen in children a ridge arising from the proximal nailfold and converging in a v shaped pattern towards the midpoint distally the nail growth pattern has no known association with medical problems and tends to resolve by early adulthood
chewiness is the mouthfeel sensation of labored chewing due to sustained elastic resistance from the food foods typically considered chewy include caramel rare steak and chewing gum chewiness is empirically measured by the metrics of chew count and chew rate
cheyne – stokes respiration ˈtʃeɪnˈstoʊks is an abnormal pattern of breathing characterized by progressively deeper and sometimes faster breathing followed by a gradual decrease that results in a temporary stop in breathing called an apnea the pattern repeats with each cycle usually taking 30 seconds to 2 minutes it is an oscillation of ventilation between apnea and hyperpnea with a crescendo diminuendo pattern and is associated with changing serum partial pressures of oxygen and carbon dioxide cheyne – stokes respiration and periodic breathing are the two regions on a spectrum of severity of oscillatory tidal volume the distinction lies in what is observed at the trough of ventilation cheyne – stokes respiration involves apnea since apnea is a prominent feature in their original description while periodic breathing involves hypopnea abnormally small but not absent breaths these phenomena can occur during wakefulness or during sleep where they are called the central sleep apnea syndrome csas it may be caused by damage to respiratory centers or by physiological abnormalities in chronic heart failure and is also seen in newborns with immature respiratory systems and in visitors new to high altitudes
the chicago union stock yards fire occurred from december 22 to december 23 1910 and resulted in the deaths of twenty one chicago fire department firemen until september 11 2001 it was the deadliest building collapse in american history in terms of firefighter fatalities although the texas city disaster of 1947 killed more firefighters overall it remains the worst such incident in chicago history
chickenpox also known as varicella is a highly contagious disease caused by the initial infection with varicella zoster virus vzv the disease results in a characteristic skin rash that forms small itchy blisters which eventually scab over it usually starts on the chest back and face then spreads to the rest of the body other symptoms may include fever feeling tired and headaches symptoms usually last five to ten days complications may occasionally include pneumonia inflammation of the brain or bacterial infections of the skin among others the disease is often more severe in adults than children symptoms begin ten to twenty one days after exposure to the virus chickenpox is an airborne disease which spreads easily through the coughs and sneezes of an infected person it may be spread from one to two days before the rash appears until all lesions have crusted over it may also spread through contact with the blisters those with shingles may spread chickenpox to those who are not immune through contact with the blisters the disease can usually be diagnosed based on the presenting symptom however in unusual cases may be confirmed by polymerase chain reaction pcr testing of the blister fluid or scabs testing for antibodies may be done to determine if a person is or is not immune people usually only get the disease once although reinfections by the virus occur these reinfections usually do not cause any symptoms the varicella vaccine has resulted in a decrease in the number of cases and complications from the disease it protects about 70 to 90 percent of people from disease with a greater benefit for severe disease routine immunization of children is recommended in many countries immunization within three days of exposure may improve outcomes in children treatment of those infected may include calamine lotion to help with itching keeping the fingernails short to decrease injury from scratching and the use of paracetamol acetaminophen to help with fevers for those at increased risk of complications antiviral medication such as aciclovir are recommended chickenpox occurs in all parts of the world as of 2013 140 million cases of chickenpox and herpes zoster occurred before routine immunization the number of cases occurring each year was similar to the number of people born since immunization the number of infections in the united states has decreased nearly 90 in 2013 chickenpox resulted in 7 000 deaths globally – down from 8 900 in 1990 death occurs in about 1 per 60 000 cases chickenpox was not separated from smallpox until the late 19 th century in 1888 its connection to shingles was determined the first documented use of the term chicken pox was in 1658 various explanations have been suggested for the use of chicken in the name one being the relative mildness of the disease
a chief visionary officer cvo is an executive function in a company like ceo or coo the title is sometimes used to formalize a high level advisory position and other times used to define a higher ranking position than that held by the ceo in some cases the cvo is added to the ceo title for ceo cvo status much in the same way that people with multiple university degrees list them after their names the cvo is expected to have a broad and comprehensive knowledge of all matters related to the business of the organization as well as the vision required to steer its course into the future the person in charge must have the core competencies of every executive and the visionary ideas to move the company forward defining corporate strategies and working plans the role has expanded to include formalizing the company ’ s strategic planning processes forging new working relationships and synergies across the organization and establishing greater transparency and accountability for those people carrying out the company ’ s strategy companies add cvos or consider doing so sometimes interchangeable with cso chief strategy officer to their management teams for several reasons changes to the business landscape — complex organizational structures rapid globalization new regulations the struggle to innovate — make it more difficult for ceos to be on top of everything even in areas as important as strategy execution and vision direction strategy development has become a continuous process and successful execution depends on rapid and effective decision making further as harvard business school professor joseph l bower has noted iron fisted control of execution often eludes the top team ’ s grasp as line executives seek to define strategy on their own terms see bower and clark g gilbert ’ s “ how managers ’ everyday decisions create — or destroy — your company ’ s strategy ” february 2007 einar stefferud co founder and cvo of first virtual holdings in 1994 is usually recognized as the first cvo another early cvo was tim roberts of broadband investment group roberts said he invented the title to recognize the visionary attributes needed to integrate a complex business with many diverse aspects roberts chose the title to define his role in the organization and didn t intend the designation to proliferate across the corporate world in the way that it has
a chignon is a temporary swelling left on an infant s head after a ventouse suction cap has been used to deliver him or her it is not a sign of serious injury and may take as little as two hours or as long as two weeks to disappear
chikungunya is an infection caused by the chikungunya virus symptoms include the fever and joint pain these typically occur two to twelve days after exposure other symptoms may include headache muscle pain joint swelling and a rash most people are better within a week however occasionally the joint pain may last for months the risk of death is around 1 in 1 000 the very young old and those with other health problems are at risk of more severe disease the virus is spread between people by two types of mosquitos aedes albopictus and aedes aegypti they mainly bite during the day the virus may circulate within a number of animals including birds and rodents diagnosis is by either testing the blood for the virus s rna or antibodies to the virus the symptoms can be mistaken for those of dengue fever and zika fever after a single infection it is believed most people become immune the best means of prevention is overall mosquito control and the avoidance of bites in areas where the disease is common this may be partly achieved by decreases mosquitoes access to water and with the use of insect repellent and mosquito nets there is no vaccine and no specific treatment as of 2016 recommendations include rest fluids and medications to help with fever and joint pain while the disease typically occurs in africa and asia outbreaks have been reported in europe and the americas since the 2000 s in 2014 more than a million suspected cases occurred in 2014 it was occurring in florida in the continental united states but as of 2016 there was no further locally acquired cases the disease was first identified in 1952 in tanzania the term is from the kimakonde language and means to become contorted
chilaiditi syndrome is a rare condition when pain occurs due to transposition of a loop of large intestine usually transverse colon in between the diaphragm and the liver visible on plain abdominal x ray or chest x ray normally this causes no symptoms and this is called chilaiditi s sign the sign can be permanently present or sporadically this anatomical variant is sometimes mistaken for the more serious condition of having air under the diaphragm pneumoperitoneum which is usually an indication of bowel perforation possibly leading to surgical interventions chilaiditi syndrome refers only to complications in the presence of chilaiditi s sign these include abdominal pain torsion of the bowel transverse colon volvulus or shortness of breath
chilblain lupus erythematosus also known as chilblain lupus erythematosus of hutchinson is a chronic unremitting form of lupus erythematosus with the fingertips rims of ears calves and heels affected especially in women
chilblains ˈtʃɪlbleɪnz — also known as pernio and perniosis — is a medical condition that occurs when a predisposed individual is exposed to cold and humidity causing tissue damage it is often confused with frostbite and trench foot damage to capillary beds in the skin causes redness itching inflammation and sometimes blisters chilblains can be reduced by keeping the feet and hands warm in cold weather and avoiding extreme temperature changes chilblains can be idiopathic spontaneous and unrelated to another disease but may also be a manifestation of another serious medical condition that needs to be investigated a history of chilblains is suggestive of a connective tissue disease such as lupus chilblains in infants together with severe neurologic disease and unexplained fevers can be seen in aicardi – goutières syndrome a rare inherited condition
a child bone fracture is a medical condition in which a bone of a child a person younger than the age of 18 is cracked or broken about 15 of all injuries in children are fracture injuries bone fractures in children are different from adult bone fractures because a child ’ s bones are still growing also more consideration needs to be taken when a child fractures a bone since it will affect the child in his or her growth
child labor in bolivia is a widespread phenomenon a 2014 document on the worst forms of child labor released by the u s department of labor estimated that approximately 20 2 of children between the ages of 7 and 14 or 388 541 children make up the labor force in bolivia indigenous children are more likely to be engaged in labor than children who reside in urban areas the activities of child laborers are diverse however the majority of child laborers are involved in agricultural labor and this activity varies between urban and rural areas bolivia has ratified the united nations convention on the rights of the child in 1990 bolivia has also ratified the international labour organization ’ s minimum age convention 1973 138 and the ilo ’ s worst forms of child labor convention 182 in july 2014 the bolivian government passed the new child and adolescent code which lowered the minimum working age to ten years old given certain working conditions the new code stipulates that children between the ages of ten and twelve can legally work given they are self employed while children between 12 and 14 may work as contracted laborers as long as their work does not interfere with their education and they work under parental supervision
child psychopathology refers to the scientific study of mental disorders in children and adolescents oppositional defiant disorder attention deficit hyperactivity disorder and autism spectrum disorder are examples of psychopathology that are typically first diagnosed during childhood mental health providers who work with children and adolescents are informed by research in developmental psychology clinical child psychology and family systems lists of child and adult mental disorders can be found in the international statistical classification of diseases and related health problems 10 th edition icd 10 published by the world health organization who and in the diagnostic and statistical manual of mental disorders fifth edition dsm 5 published by the american psychiatric association apa in addition the diagnostic classification of mental health and developmental disorders of infancy and early childhood dc 0 3 r is used in assessing mental health and developmental disorders in children up to age five
child sexual abuse accommodation syndrome csaas is a syndrome proposed by roland c summit in 1983 to describe how he believed sexually abused children responded to ongoing sexual abuse summit described how children try to resolve the experience of sexual abuse in relation to the effects of disclosure in real life he posited five stages 1 secrecy 2 helplessness 3 entrapment and accommodation 4 delayed disclosure 5 retraction according to mary de young csaas featured heavily in the day care sex abuse hysteria of the 1980 s and 1990 s because it purports to explain both delayed disclosures and withdrawals of false allegation of child sexual abuse de young argued that csaas is used to justify any statement made by a child as an indication that sexual abuse had occurred because immediate disclosure could be an indication of abuse but also delayed disclosure withdrawal and sustained denial margaret shiu wrote in 2009 that there is empirical evidence to support both the scientific validity of csaas and the tendency for sexually abused children to recant their allegations of csa child sexual abuse shiu concluded that it is therefore time for courts to stop doubting the scientific validity of csaas
child sexual abuse is a major problem in india this page is a compilation of statistics and major incidents and policy developments around the issue of child sexual abuse in india
childbirth also known as labour and delivery is the ending of a pregnancy by one or more babies leaving a woman s uterus in 2015 there were about 135 million births globally about 15 million were born before 37 weeks of gestation while between 3 and 12 were born after 42 weeks in the developed world most deliveries occur in hospital while in the developing world most births take place at home with the support of a traditional birth attendant the most common way of childbirth is a vaginal delivery it involves three stages of labour the shortening and opening of the cervix descent and birth of the baby and the pushing out of the placenta the first stage typically lasts twelve to nineteen hours the second stage twenty minutes to two hours and the third stage five to thirty minutes the first stage begins with crampy abdominal or back pains that last around half a minute and occur every ten to thirty minutes the crampy pains become stronger and closer together over time during the second stage pushing with contractions may occur in the third stage delayed clamping of the umbilical cord is generally recommended a number of methods can help with pain such as relaxation techniques opioids and spinal blocks most babies are born head first however about 4 are born feet or buttock first known as breech during labour a women can generally eat and move around as she likes pushing is not recommended during the first stage or during delivery of the head and enemas are not recommended while making a cut to the opening of the vagina is common known as an episiotomy it is generally not needed in 2012 about 23 million deliveries occurred by a surgical procedure known as caesarean section caesarean sections may be recommended for twins signs of distress in the baby or breech position this method of delivery can take longer to heal from each year complications from pregnancy and childbirth result in about 500 000 maternal deaths 7 million women have serious long term problems and 50 million women have health negative outcomes following delivery most of these occur in the developing world specific complications include obstructed labour postpartum bleeding eclampsia and postpartum infection complications in the baby include birth asphyxia
childhood absence epilepsy cae also known as pyknolepsy is an idiopathic generalized epilepsy which occurs in otherwise normal children the age of onset is between 4 – 10 years with peak age between 5 – 7 years children have absence seizures which although brief 4 – 20 seconds they occur frequently sometimes in the hundreds per day the absence seizures of cae involve abrupt and severe impairment of consciousness mild automatisms are frequent but major motor involvement early in the course excludes this diagnosis the eeg demonstrates characteristic typical 3 hz spike wave discharges prognosis is excellent in well defined cases of cae with most patients growing out of their epilepsy
juvenile arthritis also known as childhood arthritis ja is any form of arthritis or arthritis related conditions which affects individuals under the age of 16 juvenile arthritis is a chronic autoimmune disease affecting approximately 294 000 – 250 000 children and teens making juvenile arthritis one of the most common childhood diseases in the us three classifications of juvenile arthritis exist — juvenile rheumatoid arthritis jra juvenile chronic arthritis jca and juvenile idiopathic arthritis jia of which juvenile rheumatoid arthritis is the most common three main types of jra exist and classification is based upon symptoms number of joints involved and the presence of antibodies in the blood polyarticular arthritis is the first type of arthritis which affects about 30 – 40 of children with arthritis and is more common in girls than boys typically five or more joints are affected usually smaller joints such as the hands and feet but many also affect the hips neck shoulders and jaw oligoarticular pauciarticular arthritis can be early or late onset and is the second type of arthritis affecting about 50 of children with juvenile arthritis this type affects fewer than four joints usually the large joints such as knees ankles or wrists and may cause eye inflammation in girls with positive anti nuclear antibodies ana girls younger than eight are more likely to develop this type of arthritis systemic is the final classification of jra where 10 – 20 of children boys and girls equally are affected with limited movement swelling and pain in at least one joint a common symptom of this type of arthritis is a high spiking fever of 103 ° f 39 4 ° c or higher lasting for weeks or months and a rash of pale red spots on the chest thighs or other parts of the body may also be visible in most cases juvenile arthritis is caused by the body attacking its own healthy cells and tissues causing the joint to become inflamed and stiff once the joint has become inflamed and stiff damage is done to the joint and the growth of the joint may by changed or impaired early diagnosis and treatment by a paediatric rheumatologist or a rheumatologist can help manage inflammation relieve pain and prevent joint damage careful examination laboratory tests blood and urine and x rays may be some of the tests conducted by a doctor the treatment of juvenile arthritis may include medications therapy splints and in severe cases surgery these treatments are focused on reducing swelling relieving pain and maintaining full movement of joints children are encouraged to be involved in extra curricular activities physical activity when possible and to live a normal life
childhood blindness is an important cause contributing to the burden of blindness blindness in children can be defined as a visual acuity of 3 60 in the eye with better vision of a child under 16 years of age this generally means that the child cannot see something three feet about one meter away that another child could see if it was 60 feet about 20 meters away
childhood cancer also known as pediatric cancer is cancer in a child in the united states an arbitrarily adopted standard of the ages used are 0 – 14 years inclusive that is up to 14 years 11 9 months of age however the definition of childhood cancer sometimes includes young adults between 15 – 19 years old pediatric oncology is the branch of medicine concerned with the diagnosis and treatment of cancer in children worldwide it is estimated that childhood cancer has an incidence of more than 175 000 per year and a mortality rate of approximately 96 000 per year in developed countries childhood cancer has a mortality of approximately 20 of cases in low resource settings on the other hand mortality is approximately 80 or even 90 in the world s poorest countries in many developed countries the incidence is slowly increasing as rates of childhood cancer increased by 0 6 per year between 1975 and 2002 in the united states and by 1 1 per year between 1978 and 1997 in europe
childhood cataract is cataract that occurs at birth or in childhood it may be congenital or acquired
some common childhood onset chronic illnesses are cystic fibrosis cerebral palsy juvenile diabetes juvenile rheumatoid arthritis and cancer chronic illness is often a risk factor for developing psychopathologies due to the psychological toll it takes on the children and their developing brains approximately 10 million children in the united states suffer from a childhood onset chronic illness
the childhood disintegrative disorder cdd also known as heller s syndrome and disintegrative psychosis is a rare condition characterized by late onset of developmental delays — or stunning reversals — in language social function and motor skills researchers have not been successful in finding a cause for the disorder cdd has some similarity to autism and is sometimes considered a low functioning form of it in may 2013 the term cdd along with other types of autism was fused into a single diagnostic term called autism spectrum disorder under the new dsm 5 manual therefore cdd is now also called regressive autism being that this term can now refer to any type of autism spectrum disorder that involves regression including cdd cdd was originally described by austrian educator theodor heller 1869 – 1938 in 1908 35 years before leo kanner and hans asperger described autism heller had previously used the name dementia infantilis for the syndrome an apparent period of fairly normal development is often noted before a regression in skills or a series of regressions in skills the age at which this regression can occur varies but typically after 3 years of normal development the regression can be so dramatic that the child may be aware of it and may in its beginning even ask vocally what is happening to her him some children describe or appear to be reacting to hallucinations but the most obvious symptom is that skills apparently attained are lost many children are already somewhat delayed when the disorder becomes apparent but these delays are not always obvious in young children this has been described by many writers as a devastating condition affecting both the family and the individual s future as is the case with all pervasive developmental disorder categories there is considerable controversy about the right treatment for cdd
childhood gender nonconformity cgn is a phenomenon in which prepubescent children do not conform to expected gender related sociological or psychological patterns or identify with the opposite sex gender typical behavior among those who exhibit the phenomenon includes but is not limited to a propensity to cross dress refusal to take part in activities conventionally thought suitable for the gender and the exclusive choice of play mates of the opposite sex multiple studies have correlated childhood gender nonconformity with eventual homosexuality in these studies a majority of those who identify as gay or lesbian self report being gender nonconforming as children the therapeutic community is currently divided on the proper response to childhood gender nonconformity one study suggested that childhood gender nonconformity is heritable
childhood leukemia is a type of leukemia usually acute lymphocytic leukemia all and a type of childhood cancer the cure rate of childhood leukemia is generally higher than adult leukemia approaching 90 although some side effects of treatment last into adulthood the older aggressive treatments of cranial irradiation and anthracyclines such as doxorubicin caused increased risk of solid tumors heart failure growth retardation and cognitive defects leukemia is a hematological malignancy or a cancer of the blood it develops in the bone marrow the soft inner part of bones where new blood cells are made when a child has leukemia the bone marrow produces white blood cells that do not mature correctly normal healthy cells only reproduce when there is enough space for them the body will regulate the production of cells by sending signals of when to stop production when a child has leukemia the cells do not respond to the signals telling them when to stop and when to produce cells regardless of the available space
childhood obesity is a condition where excess body fat negatively affects a child s health or well being as methods to determine body fat directly are difficult the diagnosis of obesity is often based on bmi due to the rising prevalence of obesity in children and its many adverse health effects it is being recognized as a serious public health concern the term overweight rather than obese is often used in children as it is less stigmatizing
childhood rhabdomyosarcoma is a cancer that develops out of the cells that form skeletal muscles these cells are called rhabdomyoblasts this type of malignant cancer is seen most commonly in children and adolescents this is most commonly seen in the head and neck however it can be found almost anywhere in the body
childhood tumor syndrome is a condition characterized by axillary freckling neurofibromas and or cns gliomas
childlessness is the term for people men and women having no children childlessness may have personal social and or political significance
children in jail in the philippines is a significant problem according to amnesty international over 50 000 children in the philippines have been arrested and detained since 1995 torture rape and other forms of cruel and inhumane treatment are a part of everyday life for those children while they re incarcerated most are charged with minor crimes such as petty theft sniffing solvents and vagrancy
the impressive frigate chile was built 1840 in bordeaux france by order of the chilean government but without building supervision the use of poorly dried timber that had been felled outside the normal winter season was the main cause of rot damage she saw little active service after the first voyage to callao the crew was reduced to 50 from 300 men and 1841 she should be disarmed for reasons of economy but because of the tensions between perú and bolivia after the war of the confederation see battle of ingavi she was refitted again during the time the frigate was commanded by roberto simpson francisco hudson was employed on board in 1847 she was damaged by a fire on board of a neighboring salpeter ship and she beached in valparaíso as she attempted to exit the harbor after a few years she was relegated to the role of pontoon and later as training ship for the nautical school of the chilean navy until 1858
chilote school of religious imagery — spanish escuela chilota de imaginería religiosa — is an artistic and cultural manifestation that was developed during the 17 th century on the basis of the circular movement of evangelizing established by the jesuit missionaries and reaches its climax in the late 19 th century its character of school lies in that these sculptures shape a type that altered the typical archetypal of american and spanish baroque imagery as a product of cultural syncretism and miscegenation the works of this school was developed locally and are characterized by the combination and adaptation of european latin american and indigenous features this artistic expression differs from peninsular quiteña or cuzqueña artistic production it can appreciate remarkable differences in technique materials and style
chimney sweep s cancer also called soot wart is a squamous cell carcinoma of the skin of the scrotum it has the distinction of being the first reported form of occupational cancer and was initially identified by percivall pott in 1775 it was initially noticed as being prevalent amongst chimney sweeps
the people s republic of china competed at the 1984 summer olympics in los angeles united states it was the first appearance at the summer games for prc after its symbolic presence at the summer games in 1952 during which the dispute between roc and prc had started over the name of china and resulted in withdrawing all its athletes by roc since then until these games the communist prc boycotted the games due to the taiwan s presence as the republic of china in 1984 the republic of china competed as chinese taipei and the prc competed as china 215 competitors 132 men and 83 women took part in 105 events in 19 sports the first gold medal to be awarded at the los angeles olympics was also the first ever medal to be won by an athlete from china when xu haifeng won the 50 m pistol event li ning won also 6 medals in gymnastics 3 gold 2 silver and 1 bronze earning him the nickname prince of gymnasts in china
chinese foreign marriages in mainland china are a recent phenomenon and as china globalises will become increasingly common from the founding of the people ’ s republic of china prc in 1949 until the early 1990 s chinese foreign marriages were seen as outside the norm while data from the prc ’ s ministry of civil affairs indicates that the number of couples registering a chinese foreign marriage in mainland china was almost ten times greater in 2010 than in 1979 the figures for registered chinese foreign marriages are still relatively small compared to couples registered in a domestic marriage the data also suggests that most chinese foreign marriages are intra national rather than international in character an article published by elaine jeffreys and wang pan ‘ chinese foreign marriage in mainland china ’ in the university nottingham ’ s china policy institute blog notes that “ the most common type of chinese foreign marriage registered in mainland china until the late 2000 s was between a mainland chinese woman and a man from hong kong macao or taiwan ” the article also reveals that these types of marriages are more common in chinese women than they are in men the article states “ over 8 000 women registered such a marriage in 1979 that figure rose to nearly 68 000 women in 2001 declining to below 40 000 in 2010 less than in the mid 1990 s the proportion of men from mainland china registering a marriage with a foreign bride in mainland china is low 250 men in 1979 rising to a peak of around 20 000 men in 2005 and declining to less than 12 000 in 2010 ”
the chinese opening often chinese fuseki japanese 中国流布石 chūgokuryū fuseki chinese 中国流布局 zhōngguóliú bùjú is an opening pattern in the game of go it refers to the placement of black 1 black 3 and black 5 at the start of the game and so depending on white s plays is a complex of whole board go openings it is distinguished by rapid development on the side rather than making a corner enclosure it has a fairly long history originally used by japanese player hajime yasunaga and introduced to chinese go at a later stage but the chinese player chen zude pioneered it in top level play the chinese style became very popular in japan from about 1970 onwards and has by go standards a thoroughly researched theory it has two variants high with 5 in the diagram on the fourth line and low as depicted there is also a so called mini chinese fuseki an attack against the opponent s corner and placement of a stone midway between the attacking stone and a friendly corner these are now amongst the most important patterns in go opening theory
a chip famine is a phenomenon in the integrated circuit chip industry that appears approximately every four years where demand for silicon chips outstrips supply
chlamydia infection often simply known as chlamydia is a sexually transmitted infection caused by the bacterium chlamydia trachomatis most people who are infected have no symptoms when symptoms do develop this can take a few weeks following infection to occur symptoms in women may include vaginal discharge or burning with urination symptoms in men may include discharge from the penis burning with urination or pain and swelling of one or both testicles the infection can spread to the upper genital tract in women causing pelvic inflammatory disease which may result in future infertility or ectopic pregnancy repeated infections of the eyes that go without treatment can result in trachoma a common cause of blindness in the developing world chlamydia can be spread during vaginal anal or oral sex and can be passed from an infected mother to her baby during childbirth the eye infections may also be spread by personal contact flies and contaminated towels in areas with poor sanitation chlamydia trachomatis only occurs in humans diagnosis is often by screening which is recommended yearly in sexually active women under the age of twenty five others at higher risk and at the first prenatal visit testing can be done on the urine or a swab of the cervix vagina or urethra rectal or mouth swabs are required to diagnose infections in those areas prevention is by not having sex using condoms or having sex with only one other person who is not infected chlamydia can be cured by antibiotics with typically either azithromycin or doxycycline being used erythromycin or azithromycin is recommended in babies and during pregnancy sexual partners should also be treated and the infected people advised not to have sex for seven days and until symptom free gonorrhea syphilis and hiv should be tested for in those who have been infected following treatment people should be tested again after three months chlamydia is one of the most common sexually transmitted infections worldwide affecting about 4 2 of women and 2 7 of men in 2013 about 141 million new cases occurred globally in the united states about 1 4 million cases were reported in 2014 infections are most common among those between the ages of 15 and 25 and are more common in women than men in 2013 infections resulted in about 1 100 deaths the word chlamydia is from the greek χλαμύδα meaning cloak
chloracne is an acne like eruption of blackheads cysts and pustules associated with over exposure to certain halogenated aromatic compounds such as chlorinated dioxins and dibenzofurans the lesions are most frequently found on the cheeks behind the ears in the armpits and groin region the condition was first described in german industrial workers in 1897 by siegfried bettmann and was initially believed to be caused by exposure to chlorine hence the name chloracne it was only in the mid 1950 s that chloracne was associated with aromatic hydrocarbons the substances that may cause chloracne are now collectively known as chloracnegens chloracne is particularly linked to toxic exposure to dioxins byproducts of many chemical processes including the manufacture of herbicides such as agent orange — so much so that it is considered a clinical sign of dioxin exposure the severity and onset of chloracne may follow a typical asymptotic dose response relationship curve
chlorine gas poisoning is illness resulting from the effects of exposure to chlorine beyond the threshold limit value
chloroplast capture is an evolutionary phenomenon that an inter species hybridization and subsequent backcrossing genetic exchanges would yield a plant with new genetic combination for instance 1 species a s having chloroplast genome a and nuclear genome aa pollen is hybridize backcross to species b s b and bb ovule then 1 st hybrid f 1 with chloroplast genome b and nuclear genome a 50 and b 50 comes 2 species a s pollen is again hybridize backcross to f 1 s ovule then 2 nd hybrid f 2 with chloroplast genome b and nuclear genome a 75 and b 25 comes 3 species a s pollen is again hybridize backcross to f 2 s ovule then 3 rd hybrid f 3 with chloroplast genome b and nuclear genome a 87 5 and b 12 5 comes 4 after some generations a plant with new genetic combination chloroplast genome b and nuclear genome a will rise
in botany chlorosis is a condition in which leaves produce insufficient chlorophyll as chlorophyll is responsible for the green color of leaves chlorotic leaves are pale yellow or yellow white the affected plant has little or no ability to manufacture carbohydrates through photosynthesis and may die unless the cause of its chlorophyll insufficiency is treated although some chlorotic plants such as the albino arabidopsis thaliana mutant ppi 2 are viable if supplied with exogenous sucrose chlorosis is derived from the greek khloros meaning greenish yellow pale green pale pallid or fresh in viticulture the most common symptom of poor nutrition in grapevines is the yellowing of grape leaves caused by chlorosis and the subsequent loss of chlorophyll this is often seen in vineyard soils that are high in limestone such as the italian wine region of barolo in the piedmont the spanish wine region of rioja and the french wine regions of champagne and burgundy in these soils the grapevine often struggles to pull sufficient levels of iron which is a needed component in the production of chlorophyll
choanal atresia is a congenital disorder where the back of the nasal passage choana is blocked usually by abnormal bony or soft tissue membranous due to failed recanalization of the nasal fossae during fetal development
a choice function selector selection is a mathematical function f that is defined on some collection x of nonempty sets and assigns to each set s in that collection some element f s of s in other words f is a choice function for x if and only if it belongs to the direct product of x
in firearms a choke is a tapered constriction of a shotgun barrel s bore at the muzzle end chokes are almost always used with modern hunting and target shotguns to improve performance its purpose is to shape the spread of the shot in order to gain better range and accuracy chokes are implemented as either screw in chokes selected for particular applications or as fixed permanent chokes integral to the shotgun barrel chokes may be formed at the time of manufacture either as part of the barrel by squeezing the end of the bore down over a mandrel or by threading the barrel and screwing in an interchangeable choke tube chokes may also be formed even after a barrel is manufactured by increasing the diameter of the bore inside a barrel creating what is called a jug choke or by installing screw in chokes within a barrel however implemented a choke typically consists of a conical section that smoothly tapers from the bore diameter down to the choke diameter followed by a cylindrical section of the choke diameter briley manufacturing one maker of interchangeable shotgun chokes uses a conical portion about 3 times the bore diameter in length so that the shot is gradually squeezed down with minimal deformation the cylindrical section is shorter usually 0 6 to 0 75 inches 15 to 19 mm the use of interchangeable chokes allows tuning the performance of a given combination of shotgun and shotshell to achieve a desired level of performance
choke is a condition in horses in which the esophagus is blocked usually by food material although the horse is still able to breathe it is unable to swallow and may become severely dehydrated a secondary condition aspiration pneumonia may also develop if food material and saliva accumulate in the pharynx spilling into the trachea and into the lungs choke is one of the top 10 emergencies received by equine veterinarians the condition is seen in other equidae like mules and donkeys
choked flow is a compressible flow effect the parameter that becomes choked or limited is the fluid velocity choked flow is a fluid dynamic condition associated with the venturi effect when a flowing fluid at a given pressure and temperature passes through a restriction such as the throat of a convergent divergent nozzle or a valve in a pipe into a lower pressure environment the fluid velocity increases at initially subsonic upstream conditions the conservation of mass principle requires the fluid velocity to increase as it flows through the smaller cross sectional area of the restriction at the same time the venturi effect causes the static pressure and therefore the density to decrease downstream beyond the restriction choked flow is a limiting condition where the mass flow will not increase with a further decrease in the downstream pressure environment while upstream pressure is fixed note that the limited parameter is velocity and thus mass flow can be increased with increased upstream pressure increased fluid density for homogeneous fluids the physical point at which the choking occurs for adiabatic conditions is when the exit plane velocity is at sonic conditions i e at a mach number of 1 at choked flow the mass flow rate can be increased only by increasing density upstream and at the choke point the choked flow of gases is useful in many engineering applications because the mass flow rate is independent of the downstream pressure and depends only on the temperature and pressure and hence the density of the gas on the upstream side of the restriction under choked conditions valves and calibrated orifice plates can be used to produce a desired mass flow rate
in the dungeons dragons fantasy roleplaying game the choker is an aberration it can be used by dungeon masters as an enemy or ally of the player characters
choking is the mechanical obstruction of the flow of air from the environment into the lungs choking prevents breathing and can be partial or complete with partial choking allowing some although inadequate flow of air into the lungs prolonged or complete choking results in asphyxia which leads to anoxia and is potentially fatal oxygen stored in the blood and lungs can keep a person alive for several minutes after breathing stops choking can be caused by physical obstruction of the airway by a foreign body respiratory diseases that involve obstruction of the airway compression of the laryngopharynx larynx or vertebrate trachea in strangulation laryngospasm a temporary closing of the vocal cords which simulates the feeling of choking obstruction of the airway can occur at the level of the pharynx or the trachea foods that can adapt their shape to that of the pharynx such as bananas marshmallows or gelatinous candies can be a danger not just for children but for persons of any age choking due to a foreign object resulted in 162 000 deaths in 2013 up from 140 000 deaths in 1990
cholangiocarcinoma or bile duct cancer is a form of cancer that is composed of mutated epithelial cells or cells showing characteristics of epithelial differentiation that originate in the bile ducts which drain bile from the liver into the small intestine other biliary tract cancers include gallbladder cancer and cancer of the ampulla of vater cholangiocarcinoma is a relatively rare neoplasm that is classified as an adenocarcinoma a cancer that forms glands or secretes significant amounts of mucins it has an annual incidence rate of 1 – 2 cases per 100 000 in the western world but rates of cholangiocarcinoma have been rising worldwide over the past few decades prominent signs and symptoms of cholangiocarcinoma include abnormal liver function tests abdominal pain jaundice and weight loss other symptoms such as generalized itching fever and changes in color of stool or urine may also occur the disease is diagnosed through a combination of blood tests imaging endoscopy and sometimes surgical exploration with confirmation obtained after a pathologist examines cells from the tumor under a microscope known risk factors for cholangiocarcinoma include primary sclerosing cholangitis an inflammatory disease of the bile ducts infection with the parasitic liver flukes opisthorchis viverrini or clonorchis sinensis some congenital liver malformations and exposure to thorotrast thorium dioxide a chemical formerly used in medical imaging however most people with cholangiocarcinoma have no identifiable risk factors cholangiocarcinoma is considered to be an incurable and rapidly lethal cancer unless both the primary tumor and any metastases can be fully removed by surgery no potentially curative treatment exists except surgery but most people have advanced stage disease at presentation and are inoperable at the time of diagnosis people with cholangiocarcinoma are generally managed though not cured with chemotherapy radiation therapy and other palliative care measures these are also used as additional therapies after surgery in cases where resection has apparently been successful or nearly so
cholangiosarcoma is a tumor of the connective tissues of the bile ducts primary risk factors for cholangiosarcoma are primary sclerosing cholangitis and infection by clonorchis sinensis a fluke found in undercooked fish
cholecystitis is inflammation of the gallbladder symptoms include right upper abdominal pain nausea vomiting and occasionally fever often acute cholecytitis is proceeded by gallbladder attacks the pain however lasts longer than is typical in a gallbladder attack without appropriate treatment recurrent episodes of cholecystitis are common acute cholecystitis may be complicated by gallstone pancreatitis common bile duct stones or inflammation of the common bile duct more than 90 of the time acute cholecystitis is from blockage of the bile duct by a gallstone risk factors for gallstones include birth control pills pregnancy a family history of gallstones obesity diabetes liver disease or rapid weight loss occasionally acute cholecystitis occur as a result of vasculitis chemotherapy or during recovery from major trauma or burns cholecystitis is suspected based on symptoms and laboratory testing abdominal ultrasound is then typically used to confirm the diagnosis treatment is usually with laparoscopic gallbladder removal within 24 hours if possible taking pictures of the bile ducts during the surgery is recommended the routine use of antibiotics is controversial they are recommended if surgery cannot occur in a timely manner or if the case is complicated if there are also stones in the common bile duct these can either be removed before surgery by ercp or during surgery in those unable to have surgery gallbladder drainage may be tried about 10 15 of adults in the developed world have gallstones women more commonly have stones than men and they occur more commonly after the age of 40 certain ethnic groups are more often affected with for example 48 of american indians having gallstones of those with stones 1 4 have biliary colic each year of those with biliary colic about 20 without treatment develop acute cholecystitis once the gallbladder is removed outcomes are generally good without treatment chronic cholecystitis may occur the word is from greek cholecyst meaning gallbladder and itis meaning inflammation
choledochal cysts aka bile duct cyst are congenital conditions involving cystic dilatation of bile ducts they are uncommon in western countries but not as rare in east asian nations like japan and china
cholemia is a condition caused by the presence of excess bile in the blood its symptoms can include somnolence drowsiness and in extreme cases coma it is often a sign of liver disease
cholera is an infection of the small intestine by some strains of the bacterium vibrio cholerae symptoms may range from none to mild to severe the classic symptom is large amounts of watery diarrhea that lasts a few days vomiting and muscle cramps may also occur diarrhea can be so severe that it leads within hours to severe dehydration and electrolyte imbalance this may result in sunken eyes cold skin decreased skin elasticity and wrinkling of the hands and feet the dehydration may result in the skin turning bluish symptoms start two hours to five days after exposure cholera is caused by a number of types of vibrio cholerae with some types producing more severe disease than others it is spread mostly by unsafe water and unsafe food that has been contaminated with human feces containing the bacteria undercooked seafood is a common source humans are the only animal affected risk factors for the disease include poor sanitation not enough clean drinking water and poverty there are concerns that rising sea levels will increase rates of disease cholera can be diagnosed by a stool test a rapid dipstick test is available but is not as accurate prevention involves improved sanitation and access to clean water cholera vaccines that are given by mouth provide reasonable protection for about six months they have the added benefit of protecting against another type of diarrhea caused by e coli the primary treatment is oral rehydration therapy — the replacement of fluids with slightly sweet and salty solutions rice based solutions are preferred zinc supplementation is useful in children in severe cases intravenous fluids such as ringer s lactate may be required and antibiotics may be beneficial testing to see which antibiotic the cholera is susceptible to can help guide the choice cholera affects an estimated 3 – 5 million people worldwide and causes 58 000 – 130 000 deaths a year as of 2010 while it is currently classified as a pandemic it is rare in the developed world children are mostly affected cholera occurs as both outbreaks and chronically in certain areas areas with an ongoing risk of disease include africa and south east asia while the risk of death among those affected is usually less than 5 it may be as high as 50 among some groups who do not have access to treatment historical descriptions of cholera are found as early as the 5 th century bc in sanskrit the study of cholera by john snow between 1849 and 1854 led to significant advances in the field of epidemiology
cholestasis is a condition where bile cannot flow from the liver to the duodenum the two basic distinctions are an obstructive type of cholestasis where there is a mechanical blockage in the duct system that can occur from a gallstone or malignancy and metabolic types of cholestasis which are disturbances in bile formation that can occur because of genetic defects or acquired as a side effect of many medications
cholestatic pruritus is the sensation of itch due to nearly any liver disease but the most commonly associated entities are primary biliary cirrhosis primary sclerosing cholangitis obstructive choledocholithiasis carcinoma of the bile duct cholestasis also see drug induced pruritus and chronic hepatitis c viral infection and other forms of viral hepatitis
cholesteatoma is a destructive and expanding growth consisting of keratinizing squamous epithelium in the middle ear and or mastoid process although cholesteatomas are not classified as either tumors or cancers they can still cause significant problems because of their erosive and expansile properties resulting in the destruction of the bones of the middle ear ossicles as well as their possible spread through the base of the skull into the brain they are also often infected and can result in chronically draining ears
cholesterol embolism often cholesterol crystal embolism or atheroembolism sometimes blue toe or purple toe syndrome or trash foot or warfarin blue toe syndrome occurs when cholesterol is released usually from an atherosclerotic plaque and travels as an embolus in the bloodstream to lodge as an embolism causing an obstruction in blood vessels further away most commonly this causes skin symptoms usually livedo reticularis gangrene of the extremities and sometimes renal failure problems with other organs may arise depending on the site at which the cholesterol crystals enter the bloodstream when the kidneys are involved the disease is referred to as atheroembolic renal disease aerd the diagnosis usually involves biopsy removing a tissue sample from an affected organ cholesterol embolism is treated by removing the cause and giving supportive therapy statin drugs have been found to improve the prognosis
in surgical pathology strawberry gallbladder more formally cholesterolosis of the gallbladder and gallbladder cholesterolosis is a change in the gallbladder wall due to excess cholesterol the name strawberry gallbladder comes from the typically stippled appearance of the mucosal surface on gross examination which resembles a strawberry cholesterolosis results from abnormal deposits of cholesterol esters in macrophages within the lamina propria foam cells and in mucosal epithelium the gallbladder may be affected in a patchy localized form or in a diffuse form the diffuse form macroscopically appears as a bright red mucosa with yellow mottling due to lipid hence the term strawberry gallbladder it is not tied to cholelithiasis gallstones or cholecystitis inflammation of the gallbladder
cholinergic urticaria cu is a type of physical urticarias or hives that appears when a person is sweating
choluria is the presence of bile in urine choluria is a common symptom of liver diseases such as hepatitis and cirrhosis it can be described as dark or brown urine often referred to as the color of coca cola choluria is usually manifested when serum bilirubin is higher than 1 5 mg dl the presence of choluria is a useful symptom to distinguish if somebody presenting with jaundice has liver disease direct hyperbilirubinemia or hemolysis indirect hyperbilirubinemia in the first case patients have choluria due to excess conjugated direct bilirubin in blood which is eliminated by kidneys hemolysis on the contrary is characterized by unconjugated indirect bilirubin which is bound to albumin and thus not eliminated in urine
chondritis is inflammation of cartilage it takes several forms osteochondritis costochondritis relapsing polychondritis among them costochondritis is notable for feeling like a heart attack
chondroblastoma is a rare benign locally aggressive bone tumor that typically affects the epiphyses or apophyses of long bones it is thought to arise from an outgrowth of immature cartilage cells chondroblasts from secondary ossification centers originating from the epiphyseal plate or some remnant of it chondroblastoma is very uncommon accounting for only 1 2 of all bone tumors it affects mostly children and young adults with most patients being in the second decade of life or less than 20 years of age chondroblastoma shows a predilection towards the male sex with a ratio of male to female patients of 2 1 the most commonly affected site is the femur followed by the humerus and tibia less commonly affected sites include the talus and calcaneus of the foot and flat bones
calcium pyrophosphate dihydrate cppd crystal deposition disease also known as pseudogout and pyrophosphate arthropathy is a rheumatologic disorder with varied symptoms and signs arising from the accumulation of crystals of calcium pyrophosphate dihydrate in the connective tissues the alternative names emphasize particular aspects of the clinical or radiographic findings the knee joint is the most commonly affected
chondrodermatitis nodularis chronica helicis also known as chondrodermatitis nodularis helicis is a small nodular tender chronic inflammatory lesion occurring on the helix of the ear occurring most often in men
chondrodysplasia blomstrand also known as blomstrand s lethal chondrodysplasia is a rare disorder caused by mutation of the parathyroid hormone receptor resulting in the absence of a functioning pthr 1 it results in ossification of the endocrine system and intermembraneous tissues and advanced skeletal maturation
chondrodysplasia punctata is a clinically and genetically diverse group of rare diseases first described by erich conradi 1882 – 1968 that share the features of stippled epiphyses and skeletal changes types include rhizomelic chondrodysplasia punctata 215100 222765 600121 x linked recessive chondrodysplasia punctata 302950 conradi hünermann syndrome 302960 autosomal dominant chondrodysplasia punctata 118650
chondrodystrophy literally cartilage maldevelopment refers to a skeletal disorder caused by one of myriad genetic mutations that can affect the development of cartilage as a very general term it is only used in the medical literature when a more precise description of the condition is unavailable
chondroid lipomas are deep seated firm yellow tumors that characteristically occur on the legs of women they exhibit a characteristic translocation t 11 16 with a resulting c 11 orf 95 mkl 2 fusion oncogene
a chondroma is a benign cartilaginous tumor which is encapsulated with a lobular growing pattern tumor cells chondrocytes cartilaginous cells resemble normal cells and produce the cartilaginous matrix amorphous basophilic material characteristic features of this tumor include the vascular axes within the tumor which make the distinction with normal hyaline cartilage based upon location a chondroma can be described as an enchondroma or ecchondroma enchondroma tumor grows within the bone and expands it ecchondroma grows outward from the bone and this is rare treatment best left alone if it causes fractures enchondroma or is unsightly it should be removed by curettage and the defect filled with bone graft
chondromalacia patellae also known as cmp is inflammation of the underside of the patella and softening of the cartilage chondromalacia patellae is a term sometimes treated synonymously with patellofemoral pain syndrome however there is general consensus that patellofemoral pain syndrome is a term that applies only to individuals without cartilage damage thereby distinguishing it from chondromalacia patellae a condition characterized by softening of the patellar articular cartilage the cartilage under the kneecap is a natural shock absorber and overuse injury and many other factors can cause increased deterioration and breakdown of the cartilage the cartilage is no longer smooth and therefore movement and use is painful while it often affects young individuals engaged in active sports it also afflicts older adults who overwork their knees
chondromyxoid fibroma is a type of cartilaginous tumor most cases are characterised by grm 1 gene fusion or promoter swapping it can be associated with a translocation at t 1 5 p 13 p 13 a chondromyxoid fibroma cmf is an extremely rare benign cartilaginous neoplasm which accounts for 1 bone tumours
in medicine chondropathy refers to a disease of the cartilage it is frequently divided into 5 grades with 0 2 defined as normal and 3 4 defined as diseased
chondrosarcoma is a cancer composed of cells derived from transformed cells that produce cartilage chondrosarcoma is a member of a category of tumors of bone and soft tissue known as sarcomas about 30 of skeletal system cancers are chondrosarcomas it is resistant to chemotherapy and radiotherapy unlike other primary bone cancers that mainly affect children and adolescents chondrosarcoma can present at any age it more often affects the axial skeleton than the appendicular skeleton
silver leaf is a fungal disease of trees caused by the fungus plant pathogen chondrostereum purpureum it attacks most species of the rose family rosaceae particularly the genus prunus the disease is progressive and often fatal the common name is taken from the progressive silvering of leaves on affected branches it is spread by airborne spores landing on freshly exposed sapwood for this reason cherries and plums are pruned in summer when spores are least likely to be present and when disease is visible silver leaf can also happen on poming fruits like apples and pears plums are especially vulnerable in the past the name stereum purpureum pers was widely used for this fungus but according to modern taxonomy it is only distantly related to stereum actually belonging to order polyporales whereas stereum is in order russulales
chopart s fracture – dislocation is a dislocation of the mid tarsal talonavicular and calcaneocuboid joints of the foot often with associated fractures of the calcaneus cuboid and navicular
a chorangioma is a non neoplastic hamartoma like growth in the placenta consisting of blood vessels
chorangiosis is a placental pathology characterized by an abundance of blood vessels within the chorionic villi
chordee ˈkɔːrdiː is a condition in which the head of the penis curves downward or upward at the junction of the head and shaft of the penis the curvature is usually most obvious during erection but resistance to straightening is often apparent in the flaccid state as well in many cases but not all chordee is associated with hypospadias this is not the same condition as peyronie s disease which involves curvature of the shaft of the penis most commonly due to injury during adult life
chorditis is the inflammation of vocal cords vocal folds usually as a result of voice abuse but sometimes because of cancer
chordoma is a rare slow growing neoplasm thought to arise from cellular remnants of the notochord the evidence for this is the location of the tumors along the neuraxis the similar immunohistochemical staining patterns and the demonstration that notochordal cells are preferentially left behind in the clivus and sacrococcygeal regions when the remainder of the notochord regresses during fetal life
chore division is a fair division problem in which the divided resource is undesirable so that each participant wants to get as little as possible it is the mirror image of the fair cake cutting problem in which the divided resource is desirable so that each participant wants to get as much as possible both problems have heterogeneous resources meaning that the resources are nonuniform in cake division cakes can have edge corner and middle pieces along with different amounts of frosting whereas in chore division there are different chore types and different amounts of time needed to finish each chore similarly both problems assume that the resources are divisible chores can be infinitely divisible because the finite set of chores can be partitioned by chore or by time for example a load of laundry could be partitioned by the number of articles of clothing and or by the amount of time spent loading the machine the problems differ however in the desirability of the resources the chore division problem was introduced by martin gardner in 1978 chore division is often called fair division of bads in contrast to the more common problem called fair division of goods another name is dirty work problem the same resource can be either good or bad depending on the situation for example suppose the resource to be divided is the back yard of a house in a situation of dividing inheritance this yard would be considered good since each heir would like to have as much land as possible so it is a cake cutting problem but in a situation of dividing house chores such as lawn mowing this yard would be considered bad since each child would probably like to have as little land as possible to mow so it is a chore cutting problem some results from fair cake cutting can be easily translated to the chore cutting scenario for example the divide and choose procedure works equally well in both problems one of the partners divides the resource to two parts that are equal in his eyes and the other partner chooses the part that is better in his eyes the only difference is that better means larger in cake cutting and smaller in chore cutting however not all results are so easy to translate more details are given below
chorea or choreia occasionally is an abnormal involuntary movement disorder one of a group of neurological disorders called dyskinesias the term chorea is derived from the greek word χορεία dance see choreia as the quick movements of the feet or hands are comparable to dancing the term hemichorea refers to chorea of one side of the body such as chorea of one arm but not both analogous to hemiballismus
chorea acanthocytosis chac also called choreoacanthocytosis is a rare hereditary disease caused by a mutation of the gene that directs structural proteins in red blood cells it belongs to a group of four diseases characterized under the name neuroacanthocytosis when a patient s blood is viewed under a microscope some of the red blood cells appear thorny these thorny cells are called acanthocytes other effects of the disease may include epilepsy behaviour changes muscle degeneration and neuronal degradation similar to huntington s disease the average age of onset of symptoms is 35 years the disease is incurable and inevitably leads to premature death some more information about chorea acanthocytosis is that it is a very complex autosomal recessive adult onset neurodegenerative disorder it often shows itself as a mixed movement disorder in which chorea tics dystonia and even parkinsonism may appear as a symptom this disease is also characterized by the presence of a few different movement disorders including chorea dystonia etc chorea acanthocytosis is considered an autosomal recessive disorder although a few cases with autosomal dominant inheritance have been noted
chorea gravidarum is a rare type of chorea which presents with involuntary abnormal movement characterized by abrupt brief nonrhythmic nonrepetitive movement of any limb often associated with nonpatterned facial grimaces it is a complication of pregnancy which can be associated with eclampsia and its effects upon the basal ganglia it is not an etiologically or pathologically distinct morbid entity but a generic term for chorea of any cause starting during pregnancy it is associated with history of sydenham s chorea it mostly occurs in young patients the average age is 22 years recently there has been a decline in incidence which is probably the result of a decline in rheumatic fever rf which was a major cause of chorea gravidarum before the use of antibiotics for streptococcal pharyngitis
chorioamnionitis also known as intra amniotic infection iai is an inflammation of the fetal membranes amnion and chorion due to a bacterial infection it typically results from bacteria ascending into the uterus from the vagina and is most often associated with prolonged labor the risk of developing chorioamnionitis increases with each vaginal examination that is performed in the final month of pregnancy including during labor 3
choriocarcinoma is a malignant trophoblastic cancer usually of the placenta it is characterized by early hematogenous spread to the lungs it belongs to the malignant end of the spectrum in gestational trophoblastic disease gtd it is also classified as a germ cell tumor and may arise in the testis or ovary
chorioretinitis is an inflammation of the choroid thin pigmented vascular coat of the eye and retina of the eye it is a form of posterior uveitis if only the choroid is inflamed not the retina the condition is termed choroiditis the ophthalmologist s goal in treating these potentially blinding conditions is to eliminate the inflammation and minimize the potential risk of therapy to the patient
choroid glomus are enlargements of the choroid plexus located in the atria of the lateral ventricles they are commonly calcified in adults and can easily be seen as a bright tufts on ct imaging their main purpose is for the secretion of cerebrospinal fluid csf
a choroid plexus carcinoma is a type of choroid plexus tumor
choroid plexus cysts cpcs are cysts that occur within choroid plexus of the brain the brain contains pockets or spaces called ventricles with a spongy layer of cells and blood vessels called the choroid plexus this is in the middle of the fetal brain the choroid plexus has the important function of producing cerebrospinal fluid the fluid produced by the cells of the choroid plexus fills the ventricles and then flows around the brain and the spinal cord to provide a cushion of fluid around these structures cpcs can form within this structure and come from fluid trapped within this spongy layer of cells much like a soap bubble or a blister cpcs are often called soft signs or fetal ultrasound markers because some studies have found a weak association between cpcs and fetal chromosome abnormalities it is believed that many adults have one or more tiny cpcs the fetal brain may create these cysts as a normal part of development they are temporary and usually are gone by the 32 nd week of pregnancy cpcs are a rare cause of intermittent hydrocephalus this is caused by a blockage of foramina within the ventricular drainage system of the central nervous system cns which can lead to expansion of the ventricles compressing the brain the cranial cavity cannot expand to accommodate the increase in fluid volume and possibly causing damage
choroid plexus papilloma also known as papilloma of choroid plexus is a rare benign neuroepithelial intraventricular who grade i lesion found in the choroid plexus it leads to increased cerebrospinal fluid production thus causing increased intracranial pressure and hydrocephalus choroid plexus papilloma occurs in the lateral ventricles of children and in the fourth ventricle of adults this is unlike most other pediatric tumors and adult tumors in which the locations of the tumors is reversed in children brain tumors are usually found in the infratentorial region and in adults brain tumors are usually found in the supratentorial space the relationship is reversed for choroid plexus papillomas
a choroidal fissure cyst is a cyst at the level of the choroidal fissure of the brain they are usually asymptomatic and do not require treatment
choroideremia kɒˌrɔɪdᵻˈriːmi ə chd is a rare x linked recessive inherited disorder giving rise to retinal disease and eventual blindness resulting from degeneration of the choriocapillaris of the choroid and of the retinal pigment epithelium of the retina the disease results in progressive loss of vision almost exclusively in males in childhood night blindness is the most common first symptom as the disease progresses vision loss results frequently starting as an irregular ring that gradually expands both in toward central vision and out toward the extreme periphery progression continues throughout the individual s life where both the rate of change and the degree of visual loss are variable among those affected even within the same family the affected tissues include the retinal pigment epithelium rpe which is the pigmented cell layer just outside the neurosensory retina that nourishes retinal visual cells the rpe overlies the retinal visual cells and is firmly attached to the underlying choroid where degeneration of the capillary lamina of choroid choriocapillaris is also observed photoreceptors of the rpe convert light into the electrical impulses that are transferred to the brain where the images seen as a result are constructed the vessels of the choriocapillaris provide oxygen and nutrients to the rpe and photoreceptor cells in the early stages of chd the choroid and the retinal pigment epithelium begin to deteriorate after which loss of photoreceptor occurs leading to loss of vision at a molecular level the root cause of the disease is mutation leading to loss of a specific rab escort protein 1 rep 1 which with its partner rep 2 are responsible for prenylation of rab proteins where the link between the build up of unprenylated rab proteins and the developing blindness is not yet known medical approaches to the disease have resulted in the application of a diagnostic test for chd and 2014 saw the onset of clinical trials for gene therapies using viral vector borne rp 1 gene constructs aimed at protection of cells not yet lost to the disease in these early clinical studies patients have consistently shown improvements during the course of study persistence data are in the process of being gathered
the chorzów factory case french affaire relative à l usine de chorzów was a case heard before the permanent court of international justice in 1927 it was an early authority in international law that established a number of precedents in international law
christian liturgy is a pattern for worship used whether recommended or prescribed by a christian congregation or denomination on a regular basis although the term liturgy is used to mean public worship in general the byzantine rite uses the term divine liturgy to denote the eucharistic service
christian population growth is the population growth of the global christian community according to 2011 pew research center survey there are 2 18 billion christians around the world in 2010 more than three times as much from the 600 million recorded in 1910 according to a 2015 pew research center study by 2050 the christian population is expected to be 2 9 billion protestantism is one of the most dynamic religious movements in the contemporary world from 1960 to 2000 the global growth of the number of reported evangelicals grew three times the world s population rate and twice that of islam
christmas eve procession is one of the main characteristic manifestations of the maltese christmas celebrations it origins is from over 86 years ago by st george preca 1880 1962 he had no pretensions of instituting something on a large scale his only intention was to instill a truly christian spirit in commemorating the birth of christ
christmas creep is a merchandising phenomenon in which merchants and retailers exploit the commercialized status of christmas by introducing christmas themed merchandise or decorations before the traditional start of the holiday shopping season which in the united states is on the day after thanksgiving the term was first used in the mid 1980 s
a christophany is an appearance or non physical manifestation of christ traditionally the term refers to visions of christ after his ascension such as the bright light of the damascus christophany also following the example of justin martyr who identified the angel of the lord with the logos some appearances of angels in the hebrew bible are also identified by some christians as preincarnate appearances of christ
in optics chromatic aberration ca also called chromatic distortion and spherochromatism is an effect resulting from dispersion in which there is a failure of a lens to focus all colors to the same convergence point it occurs because lenses have different refractive indices for different wavelengths of light the refractive index of transparent materials decreases with increasing wavelength in degrees unique to each chromatic aberration manifests itself as fringes of color along boundaries that separate dark and bright parts of the image because each color in the optical spectrum cannot be focused at a single common point since the focal length f of a lens is dependent on the refractive index n different wavelengths of light will be focused on different positions
in mathematics chromatic homotopy theory is a subfield of stable homotopy theory that studies complex oriented cohomology theories from the chromatic point of view which is based on quillen s work relating cohomology theories to formal groups in this picture theories are classified in terms of their chromatic levels i e the heights of the formal groups that define the theories via the landweber exact functor theorem typical theories it studies include complex k theory elliptic cohomology morava k theory and tmf
chromatin bridge is a mitotic occurrence that forms when telomeres of sister chromatids fuse together and fail to completely segregate into their respective daughter cells because this event is most prevalent during anaphase the term anaphase bridge is often used as a substitute after the formation of individual daughter cells the dna bridge connecting homologous chromosomes remains fixed as the daughter cells exit mitosis and re enter interphase the chromatin bridge becomes known as an interphase bridge these phenomenon are usually visualized using the laboratory techniques of staining and fluorescence microscopy
chrome peel is a condition which occurs when the chrome coating of a wheel usually that of an automobile disintegrates in the area where the tire is bound to the wheel gradually the air escapes and a slow leak of pressure from the tire occurs a common cause is failure to thoroughly clean the inside of the wheel and tire after the usage of emergency tire inflation applications such as fix a flat under certain conditions technicians may be able to slow down the process by sanding down or smoothing out the target area of the wheel but eventually the chrome peels even more and the tire loses pressure again re chroming the wheel or replacing it altogether is more often advised
chromhidrosis also referred to as colored sweat is a rare condition characterized by the secretion of colored sweat it is caused by the deposition of lipofuscin in the sweat glands cases of red blue green yellow pink and black sweat have been reported usually chromhidrosis affects the apocrine glands mainly on the face and underarms a limited number of treatment options exist including regular application of capsaicin cream and prolonged relief may be provided by botulinum toxin treatment chromogenic pigments produced by bacteria corynebacterium in particular are implicated in this condition but their exact role still requires careful microbiological elucidation chromhidrosis of the eccrine glands is rare it occurs mainly after the ingestion of certain dyes or drugs
chromium deficiency is a disorder that results from an insufficient dietary intake of chromium it is an uncommon condition clear cases of deficiency have been observed in hospital patients who were fed defined liquid diets intravenously for long periods of time
chromium toxicity refers to the fact that chromium is toxic water insoluble chromium iii compounds and chromium metal are not considered a health hazard while the toxicity and carcinogenic properties of chromium vi have been known for a long time an investigation into hexavalent chromium release into drinking water was the basis of the true story of erin brockovich dramatised as erin brockovich film because of the specific transport mechanisms only limited amounts of chromium iii enter the cells several in vitro studies indicated that high concentrations of chromium iii in the cell can lead to dna damage acute oral toxicity ranges between 1900 and 3300 µg kg the proposed beneficial effects of chromium iii and its use in dietary supplements yielded some controversial results but recent reviews suggest that moderate uptake of chromium iii through dietary supplements poses no risk the world health organization recommended maximum allowable concentration in drinking water for chromium vi is 0 05 milligrams per litre hexavalent chromium is also one of the substances whose use is restricted by the european restriction of hazardous substances directive the ld 50 for chromium vi ranges between 50 and 150 mg kg in the body chromium vi is reduced by several mechanisms to chromium iii already in the blood before it enters the cells the chromium iii is excreted from the body whereas the chromate ion is transferred into the cell by a transport mechanism one by which sulfate and phosphate ions also enter the cell the acute toxicity of chromium vi is due to its strong oxidative properties after it reaches the bloodstream it damages blood cells by oxidation reactions hemolysis and subsequently kidney and liver failure are the results of this damage aggressive dialysis can improve the situation the carcinogenity of chromate dust has been known for a long time and in 1890 the first publication described the elevated cancer risk of workers in a chromate dye company three mechanisms have been proposed to describe the genotoxicity of chromium vi the first mechanism includes highly reactive hydroxyl radicals and other reactive radicals which are byproducts of the reduction of chromium vi to chromium iii the second process includes the direct binding of chromium v produced by reduction in the cell and chromium iv compounds to the dna the last mechanism attributes the genotoxicity to the binding to the dna of the end product of the chromium iii reduction chromium salts chromates are also the cause of allergic reactions in some people chromates are often used to manufacture among other things leather products paints cement mortar and anti corrosives contact with products containing chromates can lead to allergic contact dermatitis and irritant dermatitis resulting in ulceration of the skin sometimes referred to as chrome ulcers this condition is often found in workers that have been exposed to strong chromate solutions in electroplating tanning and chrome producing manufacturers in some parts of russia pentavalent chromium was reported as one of the causes of premature dementia
chromobacteriosis infections are a cutaneous condition caused by chromobacteria characterized by fluctuating abscesses
chromoblastomycosis also known as chromomycosis cladosporiosis fonseca s disease pedroso s disease phaeosporotrichosis or verrucous dermatitis is a long term fungal infection of the skin and subcutaneous tissue a chronic subcutaneous mycosis the infection occurs most commonly in tropical or subtropical climates often in rural areas it can be caused by many different types of fungi which become implanted under the skin often by thorns or splinters chromoblastomycosis spreads very slowly it is rarely fatal and usually has a good prognosis but it can be very difficult to cure the several treatment options include medication and surgery
in genetics chromosomal polymorphism is a condition where one species contains members with varying chromosome counts or shapes polymorphism is a general concept in biology where more than one version of a trait is present in a population in some cases of differing counts the difference in chromosome counts is the result of a single chromosome undergoing fission where it splits into two smaller chromosomes or two undergoing fusion where two chromosomes join to form one this condition has been detected in many species trichomycterus davisi for example is an extreme case where the polymorphism was present within a single chimeric individual it has also been studied in alfalfa shrews brazilian rodents and an enormous variety of other animals and plants in one instance it has been found in a human another process resulting in differing chromosomal counts is polyploidy this results in cells which contain multiple copies of complete chromosome sets possessing chromosomes of varying shapes is generally the result of a chromosomal translocation or chromosomal inversion in a translocation genetic material is transferred from one chromosome to another either symmetrically or asymmetrically a robertsonian translocation in an inversion a segment of a chromosome is flipped end for end
in genetics a chromosomal rearrangement is a type of chromosome abnormality involving a change in the structure of the native chromosome such changes may involve several different classes of events like deletions duplications inversions and translocations usually these events are caused by a breakage in the dna double helices at two different locations followed by a rejoining of the broken ends to produce a new chromosomal arrangement of genes different from the gene order of the chromosomes before they were broken structural chromosomal abnormalities are estimated to occur in around 0 5 of newborn infants some chromosomal regions are more prone to rearrangement than others and thus are the source of genetic diseases and cancer this instability is usually due to the propensity of these regions to misalign during dna repair exacerbated by defects of the appearance of replication proteins like fen 1 or pol δ that ubiquitously affect the integrity of the genome complex chromosomal rearrangements ccr are rarely seen in the general population and are defined as structural chromosomal rearrangements with at least three breakpoints with exchange of genetic material between two or more chromosomes some forms of campomelic dysplasia for example result from ccrs it is possible that speciation frequently occurs when a population becomes fixed for one or more chromosomal rearrangements that reduce fitness when they are heterozygous this theory is lacking in theoretical support because mutations that cause a large reduction in fitness can only be fixed through genetic drift in small inbred populations and the effects of chromosomal rearrangements on fitness are unpredictable and vary greatly in plant and animal species however a potential mechanism that could promote speciation is that rearrangements reduce gene flow more by suppressing recombination and extending the effects of linked isolation genes than by reducing fitness
in genetics a chromosome translocation is a chromosome abnormality caused by rearrangement of parts between nonhomologous chromosomes a gene fusion may be created when the translocation joins two otherwise separated genes it is detected on cytogenetics or a karyotype of affected cells translocations can be balanced in an even exchange of material with no genetic information extra or missing and ideally full functionality or unbalanced where the exchange of chromosome material is unequal resulting in extra or missing genes translocations can be reciprocal balanced or unbalanced or nonreciprocal balanced or unbalanced
chromosome 5 q deletion syndrome chromosome 5 q monosomy 5 q syndrome is an acquired hematological disorder characterized by loss of part of the long arm q arm band 5 q 33 1 of human chromosome 5 in bone marrow myelocyte cells this chromosome abnormality is most commonly associated with the myelodysplastic syndrome it should not be confused with partial trisomy 5 q though both conditions have been observed in the same family this should not be confused with the germ line cri du chat 5 p deletion syndrome which is a deletion of the short arm of the 5 th chromosome
chromothripsis is the phenomenon by which up to thousands of clustered chromosomal rearrangements occur in a single event in localised and confined genomic regions in one or a few chromosomes and is known to be involved in both cancer and congenital diseases it occurs through one massive genomic rearrangement during a single catastrophic event in the cell s history it is believed that for the cell to be able to withstand such a destructive event the occurrence of such an event must be the upper limit of what a cell can tolerate and survive the chromothripsis phenomenon opposes the conventional theory that cancer is the gradual acquisition of genomic rearrangements and somatic mutations over time the simplest model as to how these rearrangements occur is through the simultaneous fragmentation of distinct chromosomal regions breakpoints show a non random distribution and then subsequent imperfect reassembly by dna repair pathways or aberrant dna replication mechanisms chromothripsis occurs early in tumour development and leads to cellular transformation by loss of tumour suppressors and oncogene amplifications but recently it has been found that chromothripsis can be curative a woman who had whim warts hypogammaglobulinemia infections and myelokathexis syndrome an extremely rare autosomal dominant combined immunodeficiency disease found her symptoms disappeared during her 30 s after chromothrypsis of chromosome 2 deleted the disease allele chromothripsis is a neologism that comes from the greek words chromo which means color and represents chromosomes because they are strongly stained by particular dyes and thripsis which means shattering into pieces
chronesthesia or mental time travel is a mental ability first hypothesized by endel tulving in the 1980 s this refers to the ability to be aware of one s past or future while many may describe it as uniquely human others now argue that this ability can transcend to include non human animals such as birds the mechanisms of mental time travel are not yet fully understood since there is a level of obscurity and complexity when trying to measure if or when someone underwent mental time travel or not however studies have been conducted to map out areas of the brain that may be responsible for mental time travel
chronic actinic dermatitis also known as actinic reticuloid chronic photosensitivity dermatitis persistent light reactivity and photosensitive eczema is a condition where a subject s skin becomes inflamed due to a reaction to sunlight or artificial light patients often suffer from other related conditions of the skin that cause dermatitis in response to a variety of stimuli e g flowers sunscreens cosmetics etc diagnosis can occur at any age ranging from soon after birth to adulthood a gp may refer a patient to a dermatologist if the condition is not showing clear symptoms and a variety of tests usually completed at a hospital can then determine the exact nature and cause of the patient s condition reactions which vary depending on the severity of the case include rashes flared bumpy patches affected areas being extremely hot to touch and outbreaks shortly or within 24 hours after direct or indirect exposure to uva and or uvb light the skin most likely reacts on the upper chest hands and face however it is not unlikely for reactions to happen all over the body the patient may feel burning stinging or throbbing sensations in these areas which causes mild yet uncomfortable pain
chronic allograft nephropathy abbreviated can and also known as sclerosing chronic allograft nephropathy is the leading cause of kidney transplant failure and happens month to years after the transplant
chronic atrophic rhinitis is a chronic inflammation of nose characterised by atrophy of nasal mucosa including the glands turbinate bones and the nerve elements supplying the nose chronic atrophic rhinitis may be primary and secondary special forms of chronic atrophic rhinitis are rhinitis sicca anterior and ozaena
chronic bacterial prostatitis is a bacterial infection of the prostate gland it should be distinguished from other forms of prostatitis such as acute bacterial prostatitis and chronic pelvic pain syndrome cpps
chronic cerebrospinal venous insufficiency ccsvi or ccvi is a term developed by italian researcher paolo zamboni in 2008 to describe compromised flow of blood in the veins draining the central nervous system zamboni hypothesized that it played a role in the cause or development of multiple sclerosis ms zamboni also devised a procedure which was termed by the media as liberation procedure or liberation therapy involving venoplasty or stenting of certain veins in an attempt to improve blood flow within the medical community both the procedure and ccsvi itself have been met with skepticism zamboni s first published research was neither blinded nor did it have a comparison group zamboni also did not disclose his financial ties to esaote the manufacturer of the ultrasound specifically used in ccsvi diagnosis the liberation procedure has been criticized for possibly resulting in serious complications and deaths while its benefits have not been proven the united states food and drug administration states that it is not clear if ccsvi exists as a clinical entity and that these treatments may cause more harm research on ccsvi has been fast tracked but researchers have been unable to confirm whether ccsvi has a role in causing ms this has raised serious objections to the hypothesis of ccsvi originating multiple sclerosis additional research investigating the ccsvi hypothesis is underway a 2013 study found that ccsvi is equally rare in people with and without ms while narrowing of the cervical veins is equally common
a chronic condition is a human health condition or disease that is persistent or otherwise long lasting in its effects or a disease that comes with time the term chronic is often applied when the course of the disease lasts for more than three months common chronic diseases include arthritis asthma cancer copd diabetes and viral diseases such as hepatitis c and hiv aids in medicine the opposite of chronic is acute a chronic course is further distinguished from a recurrent course recurrent diseases relapse repeatedly with periods of remission in between the non communicable diseases are also usually lasting medical conditions but are separated by their non infectious causes in contrast some chronic diseases such as hiv aids are caused by transmissible infections in the united states 25 of adults have at least two chronic conditions chronic diseases constitute a major cause of mortality with the world health organization who attributing 38 million deaths a year to non communicable diseases
chronic deciduitis also plasma cell deciduitis is a type of long lasting inflammation that arises in pregnancy and affects the endometrial stromal tissue decidua it is associated with preterm labour the diagnosis rests primarily on the presence of plasma cells
chronic diarrhea of infancy also called toddler s diarrhea is a common condition typically affecting children between ages 6 – 30 months usually resolving by age 4 symptoms include multiple loose bowel movements per day sometimes with undigested food visible normal growth with no evidence of malnutrition and no evidence blood in the stool or infection the condition may be related to irritable bowel syndrome
chronic disease in northern ontario is a population health problem the population in northern ontario experiences worse outcomes on a number of important health indicators including higher rates of chronic disease compared to the population in the rest of ontario romanow 2002
chronic eosinophilic leukemia cel is a disease in which too many eosinophils a type of white blood cell are found in the bone marrow blood and other tissues cel may stay the same for many years or it may progress quickly to acute leukemia it is generally caused by overactivation of the oncogene pdgfra through a chromosome translocation event though a highly rare disease cel is extremely manageable with the use of gleevec which suppresses the oncogenic effects of pdgfra
chronic fatigue syndrome cfs is a medical condition characterized by long term fatigue and other symptoms that limit a person s ability to carry out ordinary daily activities quality of life of persons with cfs can be compromised biological genetic infectious and psychological mechanisms have been proposed but the cause is not understood the fatigue of cfs is not due to ongoing exertion is not much relieved by rest and is not due to any other medical condition diagnosis is based on a person s signs and symptoms evidence suggests that cognitive behavioral therapy and a gradual increase in activity suited to individual capacity can be beneficial in some cases the medication rintatolimod may be useful for certain people estimates of the number of people with the condition vary from 7 to 3 000 per 100 000 adults about one million americans and a quarter of a million people in the uk have cfs fatigue is a common symptom in many illnesses but the fatigue experienced by persons with cfs is comparatively rare cfs occurs more often in women than men and is less common among children and adolescents there is agreement that cfs has a negative effect on health happiness and productivity but there is also controversy over many aspects of the disorder physicians researchers and patient advocates promote different names and diagnostic criteria while evidence for proposed causes and treatments is often contradictory or of low quality
chronic functional abdominal pain cfap or functional abdominal pain syndrome faps is the ongoing presence of abdominal pain for which there is no known medical explanation it is quite similar to but less common than irritable bowel syndrome ibs and many of the same treatments for ibs can also be of benefit to those with cfap the fundamental difference between ibs and cfap is that in cfap unlike in ibs there is no change in bowel habits such as constipation or diarrhea bowel dysfunction is a necessary diagnostic criterion of ibs cfap is characterized by chronic pain with no physical explanation or findings no structural infectious or mechanical causes can be found it is theorized that cfap is a disorder of the nervous system where normal nociceptive nerve impulses are amplified like a stereo system turned up too loud resulting in pain this visceral hypersensitivity may be a stand alone cause of cfap or cfap may result from the same type of brain gut nervous system disorder that underlies ibs as with ibs low doses of antidepressants have been found useful in controlling the pain of cfap
chronic gastritis is a chronic inflammation of the gastric mucosa
chronic granulomatous disease cgd also known as bridges – good syndrome chronic granulomatous disorder and quie syndrome is a diverse group of hereditary diseases in which certain cells of the immune system have difficulty forming the reactive oxygen compounds most importantly the superoxide radical due to defective phagocyte nadph oxidase used to kill certain ingested pathogens this leads to the formation of granulomata in many organs cgd affects about 1 in 200 000 people in the united states with about 20 new cases diagnosed each year this condition was first discovered in 1950 in a series of 4 boys from minnesota and in 1957 was named a fatal granulomatosus of childhood in a publication describing their disease the underlying cellular mechanism that causes chronic granulomatous disease was discovered in 1967 and research since that time has further elucidated the molecular mechanisms underlying the disease bernard babior made key contributions in linking the defect of superoxide production of white blood cells to the etiology of the disease in 1986 the x linked form of cgd was the first disease for which positional cloning was used to identify the underlying genetic mutation
chronic hallucinatory psychosis is a psychosis subtype classified under other nonorganic psychosis by the icd 10 chapter v mental and behavioural disorders other abnormal mental symptoms in the early stages are as a rule absent the patient is most usually quiet and orderly with a good memory it has often been a matter of the greatest difficulty to decide under which heading of the recognized classifications individual members of this group should be placed as the hallucinations give rise to slight depression some might possibly be included under melancholia in others paranoia may develop others again might be swept into the widespread net of dementia praecox this state of affairs cannot be regarded as satisfactory for they are not truly cases of melancholia paranoia dementia praecox or any other described affection this disease as its name suggests is a hallucinatory case for it is its main feature these may be of all senses but auditory hallucinations are the most prominent at the beginning the patient may realize that the hallucination is a morbid phenomenon and unaccountable they may claim to hear a voice speaking though there is no one in the flesh actually doing so such a state of affairs may last for years and possibly though rarely for life and the subject would not be deemed insane in the ordinary sense of the word it s probable however that this condition forms the first stage of the illness which eventually develops on definite lines what usually happens is the patient seeks an explanation for the hallucinations as none is forthcoming he she tries to account for their presence and the result is a delusion and most frequently a delusion of persecution also it needs to be noted that the delusion is a comparatively late arrival and is the logical result of the hallucinations
chronic inflammatory demyelinating polyneuropathy cidp is an acquired immune mediated inflammatory disorder of the peripheral nervous system the disorder is sometimes called chronic relapsing polyneuropathy crp or chronic inflammatory demyelinating polyradiculoneuropathy because it involves the nerve roots cidp is closely related to guillain – barré syndrome and it is considered the chronic counterpart of that acute disease its symptoms are also similar to progressive inflammatory neuropathy an asymmetrical variant of cidp is known as lewis sumner syndrome
chronic inflation is an economic phenomenon occurring when a country experiences high inflation for a prolonged period of time several years or decades due to undue expansion or increase of the money supply in countries with chronic inflation inflation expectations become built in and it becomes extremely difficult to reduce the inflation rate not to be confused with hyperinflation
chronic kidney disease ckd also known as chronic renal disease is progressive loss in kidney function over a period of months or years the symptoms of worsening kidney function are not specific and might include feeling generally unwell and experiencing a reduced appetite often chronic kidney disease is diagnosed as a result of screening of people known to be at risk of kidney problems such as those with high blood pressure or diabetes and those with a bloodline relative with ckd this disease may also be identified when it leads to one of its recognized complications such as cardiovascular disease anemia pericarditis or renal osteodystrophy the latter included in the novel term ckd mbd ckd is a long term form of kidney disease thus it is differentiated from acute kidney disease acute kidney injury in that the reduction in kidney function must be present for over 3 months ckd is an internationally recognized public health problem affecting 5 – 10 of the world population chronic kidney disease is identified by a blood test for creatinine which is a breakdown product of muscle metabolism higher levels of creatinine indicate a lower glomerular filtration rate and as a result a decreased capability of the kidneys to excrete waste products creatinine levels may be normal in the early stages of ckd and the condition is discovered if urinalysis testing of a urine sample shows the kidney is allowing the loss of protein or red blood cells into the urine to fully investigate the underlying cause of kidney damage various forms of medical imaging blood tests and sometimes a kidney biopsy removing a small sample of kidney tissue are employed to find out if a reversible cause for the kidney malfunction is present previous professional guidelines classified the severity of ckd in five stages with stage 1 being the mildest and usually causing few symptoms and stage 5 being a severe illness with poor life expectancy if untreated stage 5 ckd is often called end stage kidney disease end stage renal disease or end stage kidney failure and is largely synonymous with the now outdated terms chronic renal failure or chronic kidney failure and usually means the patient requires renal replacement therapy which may involve a form of dialysis but ideally constitutes a kidney transplant recent international guidelines reclassified ckd based on cause glomerular filtration rate category g 1 g 2 g 3 a g 3 b g 4 and g 5 and albuminuria category a 1 a 2 a 3 screening of at risk people is important because treatments exist that delay the progression of ckd if an underlying cause of ckd such as vasculitis or obstructive nephropathy blockage to the drainage system of the kidneys is found it may be treated directly to slow the damage in more advanced stages treatments may be required for anemia and kidney bone disease also called renal osteodystrophy secondary hyperparathyroidism or chronic kidney disease – mineral bone disorder ckd mbd chronic kidney disease resulted in 956 000 deaths in 2013 up from 409 000 deaths in 1990
chronic kidney disease – mineral and bone disorder ckd mbd is one of the many complications associated with chronic kidney disease it represents a systemic disorder of mineral and bone metabolism due to ckd manifested by either one or a combination of the following abnormalities of calcium phosphorus phosphate parathyroid hormone or vitamin d metabolism abnormalities in bone turnover mineralization volume linear growth or strength vascular or other soft tissue calcification ckd mbd explains at least in part the high morbidity and mortality of ckd patients linking kidney and bone disease with cardiovascular complications it is a matter of discussion whether ckd mbd may be considered a real syndrome or not ckd mbd broadens the old concept of renal osteodystrophy which now should be restricted to describing the bone pathology associated with ckd thus renal osteodystrophy is currently considered one measure of the skeletal component of the systemic disorder of ckd – mbd that is quantifiable by histomorphometry of bone biopsy
chronic leukemia is an increase of abnormal white blood cells it differs from acute leukemia and is categorized as myelogenous or lymphocytic chronic leukemia may refer to chronic myelogenous leukemia chronic lymphocytic leukemia hairy cell leukemia
chronic mountain sickness cms or monge s disease is a disease in which the proportion of blood volume that is occupied by red blood cells increases polycythemia and there is an abnormally low level of oxygen in the blood hypoxemia cms can develop during extended time living at a high altitude the most frequent symptoms of cms are headache dizziness tinnitus breathlessness palpitations sleep disturbance fatigue anorexia mental confusion cyanosis and dilation of veins cms was first described in 1925 by carlos monge while acute mountain sickness is experienced shortly after ascent to high altitude chronic mountain sickness may develop after many years of living at high altitude in medicine high altitude is defined as over 2500 metres 8200 ft but most cases of cms occur at over 3000 m 10000 ft recently it has been correlated with increased expression of the genes anp 32 d and senp 1
chronic mucocutaneous candidiasis is an immune disorder of t cells it is characterized by chronic infections with candida that are limited to mucosal surfaces skin and nails however it can also be associated with other types of infections such as human papilloma virus an association with chromosome 2 has been identified types include
chronic myelogenous or myeloid or myelocytic leukemia cml also known as chronic granulocytic leukemia cgl is a cancer of the white blood cells it is a form of leukemia characterized by the increased and unregulated growth of predominantly myeloid cells in the bone marrow and the accumulation of these cells in the blood cml is a clonal bone marrow stem cell disorder in which a proliferation of mature granulocytes neutrophils eosinophils and basophils and their precursors is found it is a type of myeloproliferative disease associated with a characteristic chromosomal translocation called the philadelphia chromosome cml is now largely treated with targeted drugs called tyrosine kinase inhibitors tkis which have led to dramatically improved long term survival rates since the introduction of the first such agent in 2001 these drugs have revolutionized treatment of this disease and allow most patients to have a good quality of life when compared to the former chemotherapy drugs in western countries cml accounts for 15 20 of all adult leukemias and 14 of leukemias overall including the pediatric population
chronic myelomonocytic leukaemia cmml is a type of leukaemia which are cancers of the blood forming cells of the bone marrow in adults blood cells are formed in the bone marrow by a process that is known as haematopoiesis in cmml there are increased numbers of monocytes and immature blood cells blasts in the peripheral blood and bone marrow as well as abnormal looking cells dysplasia in at least one type of blood cell cmml shows characteristics of a myelodysplastic syndrome mds a disorder that produces abnormal looking blood cells and a myeloproliferative disorder mpd a disorder characterised by the overproduction of blood cells for this reason cmml was reclassified as a mds mpn overlap disorder in 2002 for a diagnosis of cmml the world health organisation who states that the blood monocyte count must be 1 x 109 l no philadelphia chromosome or mutations in the pdgfra or pdgfrb gene should be present the blast count must be 20 and dysplasia of at least one lineage of myeloid blood cell should be present azacitidine is a drug used to treat cmml and is approved by the food and drug administration fda and the european medicines agency stem cell transplant is also used to treat cmml and involves the transplantation of donor haematopoietic stem cells into the recipient blood transfusion and erythropoietin are used to treat disease associated anaemia
chronic neutrophilic leukemia cnl is a rare myeloproliferative neoplasm that features a persistent neutrophilia in peripheral blood myeloid hyperplasia in bone marrow hepatosplenomegaly and the absence of the philadelphia chromosome or a bcr abl fusion gene
chronic obstructive pulmonary disease copd is a type of obstructive lung disease characterized by long term poor airflow the main symptoms include shortness of breath and cough with sputum production copd typically worsens over time eventually walking up stairs or carrying things will be difficult chronic bronchitis and emphysema are older terms used for different types of copd the term chronic bronchitis is still used to define a productive cough that is present for at least three months each year for two years tobacco smoking is the most common cause of copd with a number of other factors such as air pollution and genetics playing a smaller role in the developing world one of the common sources of air pollution is poorly vented heating and cooking fires long term exposure to these irritants causes an inflammatory response in the lungs resulting in narrowing of the small airways and breakdown of lung tissue the diagnosis is based on poor airflow as measured by lung function tests in contrast to asthma the airflow reduction does not improve much with the use of a bronchodilator most cases of copd can be prevented by reducing exposure to risk factors this includes decreasing rates of smoking and improving indoor and outdoor air quality while treatment can slow worsening there is no cure copd treatments include stopping smoking vaccinations respiratory rehabilitation and often inhaled bronchodilators and steroids some people may benefit from long term oxygen therapy or lung transplantation in those who have periods of acute worsening increased use of medications and hospitalization may be needed as of 2013 copd affects 329 million people or nearly 5 percent of the global population it typically occurs in people over the age of 40 males and females are affected equally commonly in 2013 it resulted in 2 9 million deaths up from 2 4 million deaths in 1990 more than 90 of these deaths occur in the developing world the number of deaths is projected to increase further because of higher smoking rates and an aging population in many countries it resulted in an estimated economic cost of 2 1 trillion in 2010
chronic pain is pain that lasts a long time in medicine the distinction between acute and chronic pain is sometimes determined by an arbitrary interval of time since onset the two most commonly used markers being 3 months and 6 months since onset though some theorists and researchers have placed the transition from acute to chronic pain at 12 months others apply acute to pain that lasts less than 30 days chronic to pain of more than six months duration and subacute to pain that lasts from one to six months a popular alternative definition of chronic pain involving no arbitrarily fixed duration is pain that extends beyond the expected period of healing epidemiological studies have found that 10 1 to 55 2 of people in various countries have chronic pain chronic pain may originate in the body or in the brain or spinal cord it is difficult to treat and is often handled by a pain management team some people with chronic pain benefit from opioid treatment and others do not some are harmed by the treatment various nonopioid medicines are also used depending on whether the pain originates from tissue damage or is neuropathic psychological treatments including cognitive behavioral therapy and acceptance and commitment therapy have been shown effective for improving quality of life in those with chronic pain severe chronic pain is associated with increased 10 year mortality particularly from heart disease and respiratory disease people with chronic pain tend to have higher rates of depression anxiety sleep disturbances and neuroticism these are correlations and it is often not clear which factor causes another chronic pain may contribute to decreased physical activity due to fear of exacerbating pain often resulting in weight gain pain intensity pain control and resiliency to pain are influenced by different levels and types of social support that a person with chronic pain receives
chronic pancreatitis is a long standing inflammation of the pancreas that alters the organ s normal structure and functions it can present as episodes of acute inflammation in a previously injured pancreas or as chronic damage with persistent pain or malabsorption it is a disease process characterized by irreversible damage to the pancreas as distinct from reversible changes in acute pancreatitis
chronic paroxysmal hemicrania cph also known as sjaastad syndrome is a severe debilitating unilateral headache usually affecting the area around the eye it normally consists of multiple severe yet short headache attacks affecting only one side of the cranium it is more commonly diagnosed in women than in men but unlike a migraine has no neurological symptoms associated with it cph headaches are treated through the use of non steroidal anti inflammatory drugs with indomethacin found to be usually effective in eliminating symptoms paroxysmal hemicrania is classified by the frequency and duration of attacks experienced by patients episodic paroxysmal hemicrania attacks occur at least twice a year and last anywhere from seven days to a year with pain free periods of a month or longer separating them chronic paroxysmal hemicrania attacks occur over the course of more than a year without remission or with remissions lasting less than a month
chronic periodontitis is a common disease of the oral cavity consisting of chronic inflammation of the periodontal tissues that is caused by accumulation of profuse amounts of dental plaque
chronic poverty is a phenomenon whereby an individual or group is in a state of poverty over extended period of time while determining both the implicit poverty line and the duration needed to be considered long term is debated the identification of this kind of poverty is considered important because it may require different policies than those needed for addressing transient poverty
chronic progressive external ophthalmoplegia cpeo also known as progressive external ophthalmoplegia peo is a type of eye disorder characterized by slowly progressive inability to move the eyes and eyebrows it is often the only feature of mitochondrial disease in which case the term cpeo may be given as the diagnosis in other people suffering from mitochondrial disease cpeo occurs as part of a syndrome involving more than one part of the body such as kearns sayre syndrome occasionally cpeo may be caused by conditions other than mitochondrial diseases
chronic progressive lymphedema or cpl is a disease that resembles scratches it has been identified in shire clydesdale and belgian horses as well as a small number of gypsy vanners it is characterized by lymphedema and symptoms include progressive swelling thickening skin and lesions on the lower leg the disease is most likely caused by a malfunctioning lymphatic system and a compromised immune system with quite possibly a genetic component no cure is available yet only treatment has helped keep it under control for some scientists at uc davis center for equine health are continuing research on the disease with the interest cooperation and financial support from ayrshire farms of upperville virginia
chronic nonbacterial prostatitis or chronic prostatitis chronic pelvic pain syndrome cp cpps is a pelvic pain condition in men and should be distinguished from other forms of prostatitis such as chronic bacterial prostatitis and acute bacterial prostatitis this condition was formerly known as prostatodynia painful prostate
aspergillosis is an infection caused by the fungus aspergillus aspergillosis describes a large number of diseases involving both infection and growth of fungus as well as allergic responses aspergillosis can occur in a variety of organs both in humans and animals the most common sites of infection are the respiratory apparatus lungs sinuses and these infections can be invasive e g – ipa non invasive e g allergic pulmonary aspergillosis abpa chronic pulmonary and aspergilloma e g chronic cavitary semi invasive severe asthma with fungal sensitisation safs chronic pulmonary aspergillosis cpa is a long term aspergillus infection of the lung and aspergillus fumigatus is almost always the species responsible for this illness patients fall into several groups as listed below those with an aspergilloma which is a ball of fungus found in a single lung cavity which may improve or disappear or change very little over a few years aspergillus nodule chronic cavitary pulmonary aspergillosis ccpa where cavities are present in the lungs but not necessarily with a fungal ball aspergilloma chronic fibrosing pulmonary aspergillosis this may develop where pulmonary aspergillosis remains untreated and chronic scarring of the lungs occurs unfortunately scarring of the lungs does not improve most patients with cpa have or have had an underlying lung disease the most common diseases include tuberculosis atypical mycobacterium infection stage iii fibrocystic pulmonary sarcoidosis abpa lung cancer copd and emphysema asthma and silicosis
chronic recurrent multifocal osteomyelitis crmo multifocal because it can erupt in different sites primarily bones osteomyelitis because it is very similar to that disease but appears to be without any infection also known as chronic recurring multifocal osteomyelitis is a rare condition 1 1 000 000 in which the bones have lesions inflammation and pain its definition is evolving many doctors and articles described crmo as an autoimmune disease that has symptoms similar to osteomyelitis but without the infection some doctors thought crmo was related to sapho syndrome cutting edge research now classifies crmo as an inherited autoinflammatory disease but have yet to isolate the exact gene responsible for it some specialists believe they have discovered a link between crmo with a rare allele of marker d 18 s 60 resulting in a haplotype relative risk hrr of 18 other experts found that mutations in lpin 2 cause a syndromic form of chronic recurrent multifocal osteomyelitis known as majeed syndrome while mutations in pstpip 2 cause a murine form of the disorder the roles played by lpin 2 and the human homolog of pstpip 2 pstpip 2 in the etiology of chronic recurrent multifocal osteomyelitis are uncertain but are currently being investigated the professional theories seem to be moving in the direction of an inherited gene
chronic relapsing inflammatory optic neuropathy crion sometimes called chronic relapsing inflammatory optic neuritis is a form of recurrent optic neuritis that is steroid responsive patients typically present with pain associated with visual loss crion is a diagnosis of exclusion and other demyelinating autoimmune and systemic causes should be ruled out early recognition is crucial given risks for severe visual loss and because it is treatable with immunosuppressive treatment such as steroids relapse that occurs after reducing or stopping steroids is a characteristic feature
a chronic scar keratosis also known as a chronic cicatrix keratosis is a precancerous skin lesion that arises within a long standing scar
chronic sclerosing sialadenitis is a chronic long lasting inflammatory condition affecting the salivary gland relatively rare in occurrence this condition is benign but presents as hard indurated and enlarged masses that are clinically indistinguishable from salivary gland neoplasms or tumors it is now regarded as a manifestation of igg 4 related disease involvement of the submandibular glands is also known as küttner s tumor named after hermann küttner 1870 – 1932 a german oral and maxillofacial surgeon who reported four cases of submandibular gland lesions for the first time in 1896
chronic solvent induced encephalopathy cse is a condition induced by long term exposure to organic solvents typically in the workplace that lead to a wide variety of persisting sensorimotor polyneuropathies and neurobehavioral deficits even after solvent exposure has been removed this syndrome can also be referred to as psycho organic syndrome organic solvent syndrome chronic painter s syndrome occupational solvent encephalopathy solvent intoxication toxic solvent syndrome painters disease psycho organic syndrome chronic toxic encephalopathy and neurasthenic syndrome the multiple names of solvent induced syndromes combined with inconsistency in research methods makes referencing this disease difficult and its catalog of symptoms vague
chronic superficial keratitis csk also known as pannus or uberreiter ’ s disease is an inflammatory condition of the cornea in dogs particularly seen in the german shepherd dog
chronic traumatic encephalopathy cte is a progressive degenerative disease found in people who have had a severe blow or repeated blows to the head the disease was previously called dementia pugilistica dp i e punch drunk as it was initially found in those with a history of boxing cte has been most commonly found in professional athletes participating in american football rugby ice hockey boxing professional wrestling stunt performing bull riding rodeo and other contact sports who have experienced repeated concussions or other brain trauma its presence in domestic violence is also being investigated it can affect high school athletes especially american football players following few years of activity it is a form of tauopathy
chronic undermining burrowing ulcer also known as meleney gangrene or meleney s ulcer is a cutaneous condition that is a postoperative progressive bacterial gangrene it is seen in immunocompromised individuals mostly after post abdominal surgery and rapidly spreads to involve a large area
chronic venous insufficiency cvi is a medical condition in which the veins cannot pump enough blood back to the heart the most common cause of cvi is superficial venous reflux which is a treatable condition as functional venous valves are required to provide for efficient blood return from the lower extremities this condition typically affects the legs if the impaired vein function causes significant symptoms such as swelling and ulcer formation it is referred to as chronic venous disease cvi includes varicose veins and superficial venous reflux hidden varicose veins it is sometimes called chronic peripheral venous insufficiency and should not be confused with post thrombotic syndrome in which the deep veins have been damaged by previous deep vein thrombosis most cases of cvi can be improved with treatments to the superficial venous system or stenting the deep system varicose veins for example can now be treated by local anesthetic endovenous surgery the prevalence of cvi is far higher in women than in men the tampere study which examined the epidemiology of varicose veins in a large cohort of 3284 men and 3590 women demonstrated that the prevalence of varicose veins in men and women was 18 and 42 respectively the condition has been known since ancient times and hippocrates used bandaging to treat it
chronic vesiculobullous hand eczema presents with lesions that may be hyperkeratotic scaling and fissures and the dyshidrosiform pattern may be recognized only during exacerbations females outnumber males by 3 1 and there is a tendency for the pruritic 1 to 2 mm vesicles to be most pronounced at the sides of the fingers
chronic wasting disease cwd is a transmissible spongiform encephalopathy tse of mule deer white tailed deer elk or wapiti and moose elk in europe as of 2016 cwd had only been found in members of the deer family first recognized as a clinical wasting syndrome in 1967 in mule deer in a wildlife research facility in northern colorado usa it was identified as a tse in 1978 and has spread to free ranging and captive populations in 23 us states and two canadian provinces cwd is typified by chronic weight loss leading to death no relationship is known between cwd and any other tse of animals or people although reports in the popular press have been made of humans being affected by cwd a study by the centers for disease control and prevention suggests m ore epidemiologic and laboratory studies are needed to monitor the possibility of such transmissions the epidemiological study further concluded a s a precaution hunters should avoid eating deer and elk tissues known to harbor the cwd agent e g brain spinal cord eyes spleen tonsils lymph nodes from areas where cwd has been identified
chronic wound pain is a condition described as unremitting disabling and recalcitrant pain experienced by individuals with various types of chronic wounds chronic wounds such as venous leg ulcers arterial ulcers diabetic foot ulcers pressure ulcers and malignant wounds can have an enormous impact on an individual ’ s quality of life with pain being one of the most distressing symptoms the pain experienced by individuals with chronic wounds can be acute or chronic acute wound pain is intermittent and exacerbated by manipulation of the wound during procedures such as dressing changes or debridement chronic wound pain is present for six months or more and occurs without any manipulation of the wound chronic wound pain is persistent and exists at rest persistent pain is used interchangeably or to replace the term chronic pain intermittent or continuous pain that is present for three months or more is considered as persistent pain persistent pain is also referred to as neuropathic pain depending on the sensation associated with neuropathic pain it may be considered as acute or chronic acute neuropathic pain is associated with burning squeezing throbbing shooting or electric shock sensations that resolve neuropathic sensations such as numbness tingling and prickling are considered as chronic neuropathic pain chronic neuropathic pain may be intermittent or continuous and may remain unresolved post tissue healing
chrysanthemum white rust is a disease of plants caused by the fungus puccinia horiana that infects species of the genus chrysanthemum
chrysiasis gk chrysos gold osis condition of is a dermatological condition induced by the parenteral administration of gold salts usually for the treatment of rheumatoid arthritis such treatment has been superseded as the best practice for treating the disease because of numerous side effects and monitoring requirements their limited efficacy and very slow onset of action similar to silver a gold preparation used parenterally for a long period may rarely produce a permanent skin pigmentation especially if the skin is exposed to sunlight or artificial ultraviolet radiation the skin s pigmentation in this condition has been described as uniformly gray grayish purple slate gray or grayish blue and is usually limited to exposed portions of the body it may involve the conjunctivae over the scleras but usually not the oral mucosa location of pigment predominantly in the upper dermis leads to the blue component of skin color through the scattering phenomenon it is much less likely to be deposited in the nails and hair chrysiasis was said to have been much more common when medicines containing traces of gold were used for treatment of tuberculosis commonplace forms of treatment nearly fifty years ago treatments containing gold traces were also used to treat cases of rheumatoid arthritis but because the dose used for tuberculosis was higher than for arthritis it has not afflicted many subscribing to such treatments gold can be identified in the skin chemically by light microscopy electron microscopy and spectroscopy there is no way to reverse or treat chrysiasis
chrysomyxa weirii commonly known as weir ’ s cushion rust is a disease of spruce trees it is mostly a cosmetic problem causing yellowish spotting and banding on spruce needles but in some cases can cause severe premature defoliation weir ’ s cushion rust can also disfigure and reduce growth of spruce trees by targeting the tender needles of newly emerging shoots this disease is spread by wind and water splash and can further infect the spruce it currently resides on or a neighboring spruce unlike other rust diseases c weirii is autoecious only infecting spruce trees c weirii is also microcyclic producing only two of the five possible spore stages common in rust fungi trees affected by weir ’ s cushion rust usually have obvious symptoms but if treated correctly the disease can be managed
chtonobdella limbata is a species of blood sucking leech found in new south wales australia it occurs in moist forest areas being noticeable after rain often encountered on the forest floor or on low foliage a hungry leech is responsive to light or movement
the chugaev elimination is a chemical reaction that involves the elimination of water from alcohols to produce alkenes the intermediate is a xanthate it is named for its discoverer the russian chemist lev aleksandrovich chugaev 1873 1922 who first reported the reaction sequence in 1899 in the first step a xanthate salt is formed out of the alkoxide and carbon disulfide cs 2 with the addition of iodomethane the alkoxide is transformed into a methyl xanthate at about 200 ° c the alkene is formed by an intramolecular elimination in a 6 membered cyclic transition state the hydrogen atom is removed from the carbon atom β to the xanthate oxygen in a syn elimination the side product decomposes to carbonyl sulfide ocs and methanethiol the chugaev elimination is similar in mechanism to other thermal elimination reactions such as the cope elimination and ester pyrolysis xanthates typically undergo elimination from 120 to 200 ° c while esters typically require 400 to 500 ° c and amine oxides routinely react between 80 to 160 ° c
the churches of chiloé in chile s chiloé archipelago are a unique architectural phenomenon in the americas and one of the most prominent styles of chilota architecture unlike classical spanish colonial architecture the churches of chiloé are made entirely in native timber with extensive use of wood shingles the churches were built from materials to resist chiloé archipelago s humid and rainy oceanic climate built in the 18 th and 19 th centuries when chiloé archipelago was still a part of the spanish crown possessions the churches represent the fusion of european jesuit culture and local native peoples skill and traditions an excellent example of mestizo culture the churches of chiloé were designated unesco world heritage sites since 2000 the university of chile fundación cultural iglesias de chiloé and other institutions have led efforts to preserve these historic structures and to publicize them for their unique qualities
churning is an encryption function used to scramble downstream user data of the atm passive optical network system defined by the itu g 983 1 standard the standard states that churning offers a low level of protection for data confidentiality cryptanalysis had shown that the churning cipher is robustly weak
in the dungeons dragons fantasy roleplaying game the chuul is a large pale yellow lobster like aberration with a set of nasty pincers and paralytic tentacles
chyloderma is swelling of the scrotum resulting from chronic lymphatic obstruction obstruction may be caused by a nematode such as wuchereria bancrofti this condition is also known as lymphscrotum or elephantiasis scroti
chylomicron retention disease is a disorder of fat absorption it is associated with sar 1 b mutations in sar 1 b prevent the release of chylomicrons in the circulation which leads to nutritional and developmental problems it is a rare autosomal recessive disorder with around 40 cases reported worldwide since it is recessive parents usually do not express symptoms without functional chylomicrons certain fat soluble vitamins such as vitamin d and vitamin e cannot be absorbed chylomicrons have a crucial role in fat absorption and transport thus deficiency in chylomicron functioning reduces available levels of dietary fats and fat soluble vitamins
a chylothorax or chyle leak is a type of pleural effusion it results from lymph formed in the digestive system called chyle accumulating in the pleural cavity due to either disruption or obstruction of the thoracic duct in people on a normal diet this effusion can be identified by its turbid milky white appearance since chyle contains high levels of triglycercides it is important to distinguish chylothorax from pseudochylothorax pleural effusions high in cholesterol which has a similar appearance but is caused by more chronic inflammatory processes and has a different treatment
chyluria also called chylous urine is a medical condition involving the presence of chyle in the urine stream which results in urine appearing milky white it is a condition that is more prevalent among people of africa and the indian subcontinent chyluria appearance is irregular and intermittent it may last several days weeks or even months there are several factors that trigger chyluria recurrence
chytridiomycosis is an infectious disease in amphibians caused by the chytrid batrachochytrium dendrobatidis a nonhyphal zoosporic fungus chytridiomycosis has been linked to dramatic population declines or even extinctions of amphibian species in western north america central america south america eastern australia and dominica and montserrat in the caribbean much of the new world is also at risk of the disease arriving within the coming years the fungus is capable of causing sporadic deaths in some amphibian populations and 100 mortality in others no effective measure is known for control of the disease in wild populations various clinical signs are seen by individuals affected by the disease a number of options are possible for controlling this disease causing fungus though none has proved to be feasible on a large scale the disease has been proposed as a contributing factor to a global decline in amphibian populations that apparently has affected about 30 of the amphibian species of the world
chédiak – higashi syndrome is a rare autosomal recessive disorder that arises from a mutation of a lysosomal trafficking regulator protein which leads to a decrease in phagocytosis the decrease in phagocytosis results in recurrent pyogenic infections partial albinism and peripheral neuropathy it occurs in humans cattle blue persian cats australian blue rats mice mink foxes and the only known captive albino orca
cicatricial pemphigoid also known as mucous membrane pemphigoid mmp benign mucosal pemphigoid benign mucous membrane pemphigoid ocular pemphigus and scarring pemphigoid is a rare chronic autoimmune subepithelial blistering disease characterized by erosive skin lesions of the mucous membranes and skin that results in scarring of at least some sites of involvement cicatricial pemphigoid has been referred to by a variety of designations based largely on its site of involvements with examples of such terminology including desquamative gingivitis ocular pemphigus and benign mucous membrane pemphigoid however currently such designations are thought to be confusing or somewhat misleadings e g pemphigus in this context is a misnomer and this disorder is hardly benign given the extent of morbidity it can cause
cigar cells also referred to as pencil cells are red blood cells that are cigar or pencil shaped on peripheral blood smear cigar cells are commonly associated with hereditary elliptocytosis however they may also be seen in iron deficiency anemia and other pathological states that decrease red blood cell turnover and or production in the case of iron deficiency anemia microcytosis and hypochromia would also be expected
the cigarette smokers problem is a concurrency problem in computer science originally described in 1971 by suhas patil
ciguatera is a foodborne illness caused by eating certain reef fish whose flesh is contaminated with a toxin made by dinoflagellates such as gambierdiscus toxicus which live in tropical and subtropical waters these dinoflagellates adhere to coral algae and seaweed where they are eaten by herbivorous fish which in turn are eaten by larger carnivorous fish this is called biomagnification gambierdiscus toxicus is the primary dinoflagellate responsible for the production of a number of similar polyether toxins including ciguatoxin maitotoxin gambieric acid and scaritoxin as well as the long chain alcohol palytoxin other dinoflagellates that may cause ciguatera include prorocentrum spp ostreopsis spp coolia monotis thecadinium spp and amphidinium carterae predator species near the top of the food chain in tropical and subtropical waters are most likely to cause ciguatera poisoning although many other species cause occasional outbreaks of toxicity ciguatoxin is odourless tasteless and cannot be removed by conventional cooking researchers suggest that ciguatera outbreaks caused by warm climatic conditions propelled the migratory voyages of polynesians between 1000 and 1400
ciliary body melanoma is a type of cancer arising from the coloured part uvea of the eye about 12 of uveal melanoma arise from the ciliary body
ciliated cyst of the vulva also known as cutaneous müllerian cyst and paramesonephric mucinous cyst of the vulva is a cutaneous condition characterized by a cyst of the vulva
a ciliopathy is a genetic disorder of the cellular cilia or the cilia anchoring structures the basal bodies or of ciliary function although ciliopathies are usually considered to involve proteins that localize to motile and or immotile primary cilia or centrosomes it is possible for ciliopathies to be associated with proteins such as xpnpep 3 which localizes to mitochondria but is believed to affect ciliary function through proteolytic cleavage of ciliary proteins significant advances in understanding the importance of cilia were made beginning in the mid 1990 s however the physiological role that this organelle plays in most tissues remains elusive additional studies of how ciliary dysfunction can lead to such severe disease and developmental pathologies is a subject of current research
cinchonism or quinism is a pathological condition caused by an overdose of quinine or quinidine or their natural source cinchona bark quinine is medically used to treat malaria in much smaller amounts quinine is an ingredient of tonic drinks acting as a bittering agent cinchonism can occur from therapeutic doses of quinine either from one or several large doses quinidine class 1 a anti arrhythmic can also cause cinchonism symptoms to develop with as little as a single dose
circadian rhythm sleep disorders crsd a family of sleep disorders affect among other bodily processes the timing of sleep people with circadian rhythm sleep disorders are unable to go to sleep and awaken at the times commonly required for work and school as well as social needs they are generally able to get enough sleep if allowed to sleep and wake at the times dictated by their body clocks the quality of their sleep is usually normal unless they also have another sleep disorder humans like most living organisms have various biological rhythms circadian rhythms often referred to as the body clock or the biological clock control processes that re occur daily e g body temperature alertness and hormone secretion as well as sleep timing due to the circadian clock sleepiness does not continuously increase throughout the day a person s desire and ability to fall asleep is influenced both by the length of time since the person woke from an adequate sleep and by internal circadian rhythms thus a person s body is ready for sleep and for wakefulness at relatively specific times of the day sleep researcher yaron dagan states that t hese disorders can lead to harmful psychological and functional difficulties and are often misdiagnosed and incorrectly treated due to the fact that doctors are unaware of their existence
circassian nationalism is the desire among circassians to reestablish an independent circassian state with the contours of the former circassia before its russian conquest it is often classified as national revival because many themes involve the repatriation of diaspora circassians and the revitalization of the adyghe language
the circe effect is a phenomenon proposed by william jencks seen in chemistry and biochemistry where in order to speed up a reaction the ground state of the substrate is destabilized by an enzyme
circle packing in an equilateral triangle is a packing problem in discrete mathematics where the objective is to pack n unit circles into the smallest possible equilateral triangle optimal solutions are known for n 13 and for any triangular number of circles and conjectures are available for n 28 a conjecture of paul erdős and norman oler states that if n is a triangular number then the optimal packings of n − 1 and of n circles have the same side length that is according to the conjecture an optimal packing for n − 1 circles can be found by removing any single circle from the optimal hexagonal packing of n circles this conjecture is now known to be true for n ≤ 15 minimum solutions for the side length of the triangle a closely related problem is to cover the equilateral triangle with a given number of circles having as small a radius as possible
circle packing in a right isosceles triangle is a packing problem where the objective is to pack n unit circles into the smallest possible isosceles right triangle minimum solutions lengths shown are length of leg are shown in the table below solutions to the equivalent problem of maximizing the minimum distance between n points in an isosceles right triangle are known to be optimal for n 8 in 2011 a heuristic algorithm found 18 improvements on previously known optima the smallest of which was for n 13
circuit breaker is a design pattern in modern software development circuit breaker is used to detect failures and encapsulates logic of preventing a failure to reoccur constantly during maintenance temporary external system failure or unexpected system difficulties
in theoretical computer science the circuit satisfiability problem also known as circuit sat circuitsat csat etc is the decision problem of determining whether a given boolean circuit has an assignment of its inputs that makes the output true
a circulatory collapse is defined as a general or specific failure of the circulation either cardiac or peripheral in nature although the mechanisms causes and clinical syndromes are different the pathogenesis is the same the circulatory system fails to maintain the supply of oxygen and other nutrients to the tissues and to remove the carbon dioxide and other metabolites from them the failure may be hypovolemic distributive a common cause of this could be shock or trauma from injury or surgery a general failure is one that occurs across a wide range of locations in the body such as systemic shock after the loss of a large amount of blood collapsing all the circulatory systems in the legs a specific failure can be traced to a particular point such as a clot cardiac circulatory collapse affects the vessels of the heart such as the aorta and is almost always fatal it is sometimes referred to as acute circulatory failure peripheral circulatory collapse involves outlying arteries and veins in the body and can result in gangrene organ failure or other serious complications this form is sometimes called peripheral vascular failure shock or peripheral vascular shutdown a milder or preliminary form of circulatory collapse is circulatory insufficiency
a circumhorizontal arc is an optical phenomenon that belongs to the family of ice halos formed by the refraction of sun or moonlight in plate shaped ice crystals suspended in the atmosphere typically in cirrus or cirrostratus clouds in its full form the arc has the appearance of a large brightly spectrum coloured band running parallel to the horizon located far below the sun or moon the distance below the sun or moon is twice as far as the common 22 degree halo red is the uppermost colour often when the halo forming cloud is small or patchy only fragments of the arc are seen as with all halos it can be caused by the sun as well as but much more rarely by the moon other currently accepted names for the circumhorizontal arc are circumhorizon arc or lower symmetric 46 ° plate arc the misleading term fire rainbow is sometimes used to describe this phenomenon although it is neither a rainbow nor related in any way to fire the term apparently coined in 2006 may originate in the occasional appearance of the arc as flames in the sky when it occurs in fragmentary cirrus clouds
circumostomy eczema frequently occurs after an ileostomy or colostomy in which there is eczematization or autosensitization of the surrounding skin
circumvallate placenta is a placental disease in which the fetal membranes chorion and amnion double back on the fetal side around the edge of the placenta after delivery a circumvallate placenta has a thick ring of membranes on its fetal surface complete circumvallate placenta occurs in approximately 1 of pregnancies it is diagnosed prenatally by medical ultrasonography although one 1997 study of prenatal ultrasounds found that of the normal placentas 35 were graded as probably or definitely circumvallate by at least one sonologist and all sonologists misgraded the case of complete circumvallation as normal the condition is associated with perinatal complications such as placental abruption oligohydramnios abnormal cardiotocography preterm birth and miscarriage
the circumzenithal arc also called the circumzenith arc cza upside down rainbow and the bravais arc is an optical phenomenon similar in appearance to a rainbow but belonging to the family of halos arising from refraction of sunlight through ice crystals generally in cirrus or cirrostratus clouds rather than from raindrops the arc is located at a considerable distance approximately 46 ° above the sun and at most forms a quarter of a circle centered on the zenith it has been called a smile in the sky its first impression being that of an upside down rainbow the cza is one of the brightest and most colorful members of the halo family its colors ranging from violet on top to red at the bottom are purer than those of a rainbow because there is much less overlap in their formation the intensity pattern distribution along the circumzenithal arc requires consideration of several effects fresnel s reflection transmission amplitudes atmospheric attenuation chromatic dispersion i e the width of the arc azimuthal angular dispersion ray bundling and geometrical constraints in effect the cza is brightest when the sun is at about 20 ° contrary to public awareness the cza is not a rare phenomenon but it tends to be overlooked since it occurs so far overhead it is worthwhile to look out for it when sun dogs are visible since the same type of ice crystals that cause them plate shaped hexagonal prisms in horizontal orientation are responsible for the cza
cirrhosis is a condition in which the liver does not function properly due to long term damage typically the disease comes on slowly over months or years early on there are often no symptoms as the disease worsens a person may become tired weak itchy have swelling in the lower legs develop yellow skin bruise easily have fluid build up in the abdomen or develop spider like blood vessels on the skin the fluid build up in the abdomen may become spontaneously infected other complications include hepatic encephalopathy bleeding from dilated veins in the esophagus or dilated stomach veins and liver cancer hepatic encephalopathy results in confusion and possibly unconsciousness cirrhosis is most commonly caused by alcohol hepatitis b hepatitis c and non alcoholic fatty liver disease typically more than two or three drinks per day over a number of years is required for alcoholic cirrhosis to occur non alcoholic fatty liver disease is due to a number of reasons including being overweight diabetes high blood fats and high blood pressure a number of less common causes include autoimmune hepatitis primary biliary cirrhosis hemochromatosis certain medications and gallstones cirrhosis is characterized by the replacement of normal liver tissue by scar tissue these changes lead to loss of liver function diagnosis is based on blood testing medical imaging and liver biopsy some causes of cirrhosis such as hepatitis b can be prevented by vaccination treatment partly depends on the underlying cause the goal is often to prevent worsening and complications avoiding alcohol is recommended hepatitis b and c may be treatable with antiviral medications autoimmune hepatitis may be treated with steroid medications ursodiol may be useful if the disease is due to blockage of the bile ducts other medications may be useful for complications such as swelling hepatic encephalopathy and dilated esophageal veins in severe cirrhosis a liver transplant may be an option cirrhosis resulted in 1 2 million deaths in 2013 up from 0 8 million deaths in 1990 of these alcohol caused 384 000 hepatitis c caused 358 000 and hepatitis b caused 317 000 in the united states more men die of cirrhosis than women the first known description of the condition is by hippocrates in the 5 th century bce the word cirrhosis is from greek κίρρωσις kirrhos κιρρός yellowish and osis ωσις meaning condition
a cirsoid aneurysm is the dilation of a group of blood vessels due to congenital malformations with av arterio venous shunting cirsoid means resembling a varix sometimes a minor traumatic episode such as a fall or bump on the head can lead to the formation of a cirsoid aneurysm often these are trivial traumatic episodes cirsoid aneurysm in general is a hemangioma of an artery it most commonly occurs over the head usually the superficial temporal artery and also it s branches it can also occur in places where medium vessels lie over bones without much intervening tissues between them and the skin the superficial temporal artery is the most commonly involved artery
the cistern of great cerebral vein quadrigeminal cistern ambient cistern is a dilation of the subarachnoid space between the splenium of the corpus callosum and the superior surface of the cerebellum it extends between the layers of the tela chorioidea of the third ventricle and contains the great cerebral vein and the pineal gland
citrullinemia is an autosomal recessive urea cycle disorder that causes ammonia and other toxic substances to accumulate in the blood since the substances also accumulate in the urine the disorder can also be called citrullinuria two forms of citrullinemia have been described both having different signs and symptoms and are caused by mutations in different genes citrullinemia belongs to a class of genetic diseases called urea cycle disorders the urea cycle is a sequence of chemical reactions taking place in the liver these reactions process excess nitrogen generated when protein is used for energy by the body to make urea which is excreted by the kidneys
citrullinemia type i ctln 1 also known as arginosuccinate synthetase deficiency is a rare disease caused by a deficiency in argininosuccinate synthetase an enzyme involved in excreting excess nitrogen from the body there are mild and severe forms of the disease which is one of the urea cycle disorders
citrus black spot is a fungal disease caused by guignardia citricarpa this ascomycete fungus affects citrus plants throughout subtropical climates causing a reduction in both fruit quantity and quality symptoms include both fruit and leaf lesions the latter being critical to inter tree dispersal strict regulation and management is necessary to control this disease since there are currently no citrus varieties that are resistant
citrus canker is a disease affecting citrus species caused by the bacterium xanthomonas axonopodis infection causes lesions on the leaves stems and fruit of citrus trees including lime oranges and grapefruit while not harmful to humans canker significantly affects the vitality of citrus trees causing leaves and fruit to drop prematurely a fruit infected with canker is safe to eat but too unsightly to be sold the disease which is believed to have originated in southeast asia is extremely persistent when it becomes established in an area citrus groves have been destroyed in attempts to eradicate the disease brazil and the united states are currently suffering from canker outbreaks
citrus exocortis is a disease of citrus plants caused by the citrus exocortis viroid cevd it can causes stunted growth and reduced yields in affected plants the disease is also sometimes called scalybutt cevd can also infect tomato plants the resulting disease is sometimes called tomato bunchy top disease
citrus greening disease chinese 黃龍病 pinyin huánglóngbìng literally yellow dragon disease or hlb is a disease of citrus caused by a vector transmitted pathogen the causative agents are motile bacteria candidatus liberibacter spp the disease is vectored and transmitted by the asian citrus psyllid diaphorina citri kuwayama and the african citrus psyllid trioza erytreae del guercio also known as the two spotted citrus psyllid it has also been shown to be graft transmissible three different types of hlb are currently known the heat tolerant asian form and the heat sensitive african and american forms the disease was first described in 1929 and first reported in china in 1943 the african variation was first reported in 1947 in south africa where it is still widespread
the citrus stubborn disease is a plant disease affecting species in the genus citrus spiroplasma citri a mollicute bacterium species is the causative agent of the disease it is present in the phloem of the affected plant and transmitted by several leafhoppers including circulifer tenellus beet leafhopper and scaphytopius nitridus in citrus growing regions of california and arizona and circulifer haematoceps in the mediterranean region the host most notably affected is sweet orange but the bacterium can also infect weeds such as periwinkle vinca rosea and london rocket sisymbrium irio yellowed plants of chinese cabbage and pak choi brassica rapa can be infected by s citri in the wild shortpod mustard hirschfeldia incana infested by the beet leafhopper circulifer tenellus can prove to be an important reservoir of infection s citri can also be transmitted to china aster callistephus chinensis shasta daisy leucanthemum × superbum red clover trifolium pratense and radish raphanus sativus by the leafhopper scaphytopius nitridus the bacterium has also been shown to experimentally infect white clover trifolium repens using euscelis plebejus as a vector symptoms on citrus trees are variable but typically include small size with upright position fruits harvested from citrus trees with severe symptoms of citrus stubborn disease can be acorn shaped or lopsided
the city of wellington by election was held on 9 march 1898 to decide the next member for that electorate in parliament the contest was caused by resignation of robert stout and was won by former mayor of wellington john duthie
civet zibeth zibet zibetum also known as civet musk is the glandular secretion produced by both sexes of the civet cat viverridae
civil death latin civiliter mortuus is the loss of all or almost all civil rights by a person due to a conviction for a felony or due to an act by the government of a country that results in the loss of civil rights it is usually inflicted on persons convicted of crimes against the state or adults determined by a court to be legally incompetent because of mental disability in medieval europe felons lost all civil rights upon their conviction this civil death often led to actual death since anyone could kill and injure a felon with impunity under the holy roman empire a person declared civilly dead was referred to as vogelfrei ‘ free as a bird ’ and could even be killed since they were completely outside the law historically outlawry that is declaring a person as an outlaw was a common form of civil death in the us the disenfranchisement of felons has been called a form of civil death as has being subjected to collateral consequences in general
a civil wrong or wrong is a cause of action under the law of the governing body tort breach of contract and breach of trust are types of civil wrong something that amounts to a civil wrong is said to be wrongful a wrong involves the violation of a right because wrong and right are complementary terms a statement that an act complained of is legally wrongful as regards the party complaining implicitly includes a statement that the act complained of prejudicially affects the party complaining in some legal right the law that relates to civil wrongs is part of the branch of the law that is called the civil law a civil wrong is capable of being followed by what are called civil proceedings it is a misnomer to describe a civil wrong as a civil offence the law of england recognised the concept of a wrong before it recognised the distinction between civil wrongs and crimes which distinction was developed during the thirteenth century
claim clubs also called actual settlers associations or squatters clubs were a nineteenth century phenomenon in the american west usually operating within a confined local jurisdiction these pseudo governmental entities sought to regulate land sales in places where there was little or no legal apparatus to deal with land related quarrels of any size some claim clubs sought to protect squatters while others defended early land owners in the twentieth century sociologists suggested that claim clubs were a pioneer adaptation of democratic bodies on the east coast including town halls
the term clairvoyance klerˈvɔɪəns from french clair meaning clear and voyance meaning vision is the alleged ability to gain information about an object person location or physical event through extrasensory perception any person who is claimed to have some such ability is said accordingly to be a clairvoyant klerˈvɔɪənt one who sees clearly claims for the existence of paranormal and psychic abilities such as clairvoyance have not been supported by scientific evidence published in high impact factor peer reviewed journals parapsychology explores this possibility but the existence of the paranormal is not accepted by the scientific community parapsychology including the study of clairvoyance is an example of pseudoscience
the claisen rearrangement not to be confused with the claisen condensation is a powerful carbon – carbon bond forming chemical reaction discovered by rainer ludwig claisen the heating of an allyl vinyl ether will initiate a 3 3 sigmatropic rearrangement to give a γ δ unsaturated carbonyl the claisen rearrangement discovered in 1912 the claisen rearrangement is the first recorded example of a 3 3 sigmatropic rearrangement many reviews have been written
it was promulgated in the 16 th century by the council of trent in the decree called tametsi prior to that time an unwitnessed exchange of marriage vows was deplored but valid the decree was enforced only in those regions where it could be proclaimed in the vernacular the witnesses must be the parish priest or another priest with permission either from the parish priest or the local ordinary and the other two witnesses must be capable of giving witness to the marriage vows it was later modified by the decree ne temere to require specific priests such as the local pastor of the couple s residence further modifications provided that the priest was not necessary if one of the marrying parties was in danger of death or if the vows could not be exchanged before a priest in a reasonable amount of time
in hydrodynamics the clapotis from french lapping of water is a non breaking standing wave pattern caused for example by the reflection of a traveling surface wave train from a near vertical shoreline like a breakwater seawall or steep cliff the resulting clapotic wave does not travel horizontally but has a fixed pattern of nodes and antinodes these waves promote erosion at the toe of the wall and can cause severe damage to shore structures the term was coined in 1877 by french mathematician and physicist joseph valentin boussinesq who called these waves ‘ le clapotis ’ meaning ‘ ’ the lapping in the idealized case of full clapotis where a purely monotonic incoming wave is completely reflected normal to a solid vertical wall the standing wave height is twice the height of the incoming waves at a distance of one half wavelength from the wall in this case the circular orbits of the water particles in the deep water wave are converted to purely linear motion with vertical velocities at the antinodes and horizontal velocities at the nodes the standing waves alternately rise and fall in a mirror image pattern as kinetic energy is converted to potential energy and vice versa in his 1907 text naval architecture cecil peabody described this phenomenon at any instant the profile of the water surface is like that of a trochoidal wave but the profile instead of appearing to run to the right or left will grow from a horizontal surface attain a maximum development and then flatten out till the surface is again horizontal immediately another wave profile will form with its crests where the hollows formerly were will grow and flatten out etc if attention is concentrated on a certain crest it will be seen to grow to its greatest height die away and be succeeded in the same place by a hollow and the interval of time between the successive formations of crests at a given place will be the same as the time of one of the component waves
in mathematics especially in the fields of group theory and representation theory of groups a class function is a function on a group g that is constant on the conjugacy classes of g in other words it is invariant under the conjugation map on g such functions play a basic role in representation theory
the classical limit or correspondence limit is the ability of a physical theory to approximate or recover classical mechanics when considered over special values of its parameters the classical limit is used with physical theories that predict non classical behavior
obesity is a medical condition in which excess body fat has accumulated to the extent that it has an adverse effect on health relative weight and body mass index bmi are nearly identical and are reasonable estimates of body fatness as measured by percentage body fat however bmi does not account for the wide variation in body fat distribution and may not correspond to the same degree of fatness or associated health risk in different individuals and populations other measurements of fat distribution include the waist – hip ratio and body fat percentage normal weight obesity is a condition of having normal body weight but high body fat percentages with the same health risks of obesity
pneumonia can be classified in several ways most commonly by where it was acquired hospital versus community but may also by the area of lung affected or by the causative organism there is also a combined clinical classification which combines factors such as age risk factors for certain microorganisms the presence of underlying lung disease or systemic disease and whether the person has recently been hospitalized
the classification of transsexual people and people with other gender atypicalities has been done since the mid 1960 s in medicine and psychiatry terms such as heterosexual and homosexual have been based on a person s sex assignment at birth which has prompted the increased use of androphilia and gynephilia to avoid terminological confusion in social and political contexts classification is often relative to one s desired sex
claude s syndrome is a form of brainstem stroke syndrome characterized by the presence of an ipsilateral oculomotor nerve palsy contralateral hemiparesis contralateral ataxia and contralateral hemiplegia of the lower face tongue and shoulder claude s syndrome affects occulomotor nerve red nucleus and brachium conjunctivum
claudication literally limping latin is a medical term usually referring to impairment in walking or pain discomfort or tiredness in the legs that occurs during walking and is relieved by rest the perceived level of pain from claudication can be mild to extremely severe claudication is most common in the calves but it can also affect the feet thighs hips buttocks or arms the word claudication comes from the latin claudicare meaning to limp claudication that appears after a short amount of walking may sometimes be described by us medical professionals by the number of typical city street blocks the patient can walk before the onset of claudication thus one block claudication refers to claudication that appears after walking one block two block claudication appears after walking two blocks etc
the clave is a rhythmic pattern used as a tool for temporal organization in afro cuban music it is present in a variety of genres such as abakuá music rumba conga son mambo salsa songo timba and afro cuban jazz the five stroke clave pattern represents the structural core of many afro cuban rhythms the clave pattern originated in sub saharan african music traditions where it serves essentially the same function as it does in cuba in ethnomusicology clave is also known as a key pattern guide pattern phrasing referent timeline or asymmetrical timeline the clave pattern is also found in the african diaspora musics of haitian vodou drumming afro brazilian music african american music which is known as hambone and also found in louisiana voodoo drumming as well as afro uruguayan music candombe the clave or known in the united states as hambone pattern is used in north american popular music as a rhythmic motif or simply a form of rhythmic decoration
a clavicle fracture is a bone fracture in the clavicle or collarbone it is often caused by a fall onto an outstretched upper extremity a fall onto a shoulder or a direct blow to the clavicle many research projects are underway regarding the medical healing process of clavicle fractures
clay shoveler s fracture is a stable fracture through the spinous process of a vertebra occurring at any of the lower cervical or upper thoracic vertebrae classically at c 6 or c 7 in australia in the 1930 s men digging deep ditches tossed clay 10 to 15 feet above their heads using long handled shovels instead of separating the sticky clay would sometimes stick to the shovel the worker would hear a pop and feel a sudden pain between the shoulder blades unable to continue working the mechanism of injury is believed to be secondary to muscle pull and reflex with force transmission through the supraspinous ligaments the tremendous force pulls on the spinous process producing an avulsion fracture the fracture is diagnosed by plain film examination
a cleaning event is a phenomenon whereby dust is removed from solar panels particularly ones on mars by the action of wind the term cleaning event is used on several nasa webpages generally the term is used in reference to the fact that martian winds have blown dust clear off the solar panels of probes on mars increasing their energy output the term started being used in 2004 as the mars exploration rovers solar panels started to benefit from these events the rovers were expected to last about 90 sols martian days on mars after which dust would cover their solar panels and reduce solar power to levels too low for the rovers to operate however power levels went back up due to the cleaning events caused by the winds in the martian atmosphere periodic cleaning events have allowed the mer rovers to operate far longer than the planned 3 months while spirit rover finally ceased operation in 2011 opportunity rover remains active as of 2016 more than 12 years after landing cleaning events can either be rapid such as overnight or over many days where solar power slowly goes up for example the mer a spirit rover on april 18 2009 and april 28 2009 the power output of the solar arrays were increased by cleaning events the power output of spirit s solar arrays increased from 223 watt hours per day on march 31 2009 to 372 watt hours per day on april 29 2009 other factors that affect solar power output include the opacity of the martian atmosphere and martian seasonal changes the materials adherence experiment had a glass plate that allowed the dust to be cleared off and protected a gallium arsenide photo cell it was part of the mars pathfinder program in the 1990 s
clear cell adenocarcinoma cca of the vagina or cervix is a rare adenocarcinoma cancer often linked to diethylstilbestrol des a drug which was prescribed in the mistaken belief that it prevented miscarriage and ensured a healthy pregnancy
clear cell sarcoma formerly known as malignant melanoma of the soft parts is a rare form of cancer called sarcoma it is known to occur mainly in the soft tissues and dermis rare forms were thought to occur in the gastrointestinal tract before they were discovered to be different and redesignated as gnet recurrence is common it has been associated with both ewsr 1 atf 1 and ewsr 1 creb 1 fusion transcripts clear cell sarcoma of the soft tissues in adults is not related to the pediatric tumor known as clear cell sarcoma of the kidney
clear cell acanthoma also known as acanthome cellules claires of degos and civatte degos acanthoma and pale cell acanthoma is a benign clinical and histological lesion initially described as neoplastic which some authors now regard as a reactive dermatosis it usually presents as a moist solitary firm brown red well circumscribed 5 mm to 2 cm nodule or plaque on the lower extremities of middle aged to elderly individuals the lesion has a crusted scaly peripheral collarette and vascular puncta on the surface it is characterized by slow growth and may persist for years the clinical differential diagnosis includes dermatofibroma inflamed seborrheic keratosis pyogenic granuloma basal cell carcinoma squamous cell carcinoma verruca vulgaris psoriatic plaque and melanoma
clear cell papillary renal cell carcinoma abbreviated ccprcc and also known as clear cell tubulopapillary renal cell carcinoma is a rare subtype of renal cell carcinoma rcc that has microscopic morphologic features of papillary renal cell carcinoma and clear cell renal cell carcinoma yet is pathologically distinct based on molecular changes and immunohistochemistry
the clear cell renal cell carcinoma ccrcc is a type of renal cell carcinoma
cleft lip and cleft palate also known as orofacial cleft is a group of conditions that includes cleft lip cl cleft palate cp and both together clp a cleft lip contains an opening in the upper lip that may extend into the nose the opening may be on one side both sides or in the middle a cleft palate is when the roof of the mouth contains an opening into the nose these disorders can result in feeding problems speech problems hearing problems and frequent ear infections less than half the time the condition is associated with other disorders cleft lip and palate are the result of tissues of the face not joining properly during development as such they are a type of birth defect the cause is unknown in most cases risk factors include smoking during pregnancy diabetes obesity an older mother and certain medications such as some used to treat seizures cleft lip and cleft palate can often be diagnosed during pregnancy with an ultrasound exam a cleft lip or palate can be successfully treated with surgery this is often done in the first few months of life for cleft lip and before eighteen months for cleft palate speech therapy and dental care may also be needed with appropriate treatment outcomes are good cleft lip and palate occurs in about 1 to 2 per 1000 births in the developed world cl is about twice as common in males as females while cp without cl is more common in females in 2013 it resulted in about 3 300 deaths globally down from 7 600 deaths in 1990 the condition was formerly known as a hare lip because of its resemblance to a hare or rabbit but that term is now generally considered to be offensive
cleft lip and or palate is a congenital abnormality that is seen frequently around the world on average about 1 in every 500 750 live births result in a cleft hardin jones karnell peterson falzone 2001 furthermore in the u s the prevalence for cleft lip with or without cleft palate cl p is 2 2 to 11 7 per 10 000 births cleft palate alone cp results in a prevalence rate of 5 5 to 6 6 per 10 000 births forrester merz 2004 cleft of the lip palate or both is one of the most common congenital abnormalities and has a birth prevalence rate ranging from 1 1000 to 2 69 1000 amongst different parts of the world mcleod saeed arana urioste 2004
cleidocranial dysostosis also called cleidocranial dysplasia is congenital disorder that mostly affects the development of bones and teeth there is typically either poorly developed or no collarbones which often allows the shoulders to be brought close together the front of the skull often does not close under later and those affected are short other symptoms may include a prominent forehead wide set eyes abnormal teeth and a flat nose symptoms can vary between people however intelligence is typically normal the condition is either inherited from a person s parents or occurs as a new mutation it is inherited in an autosomal dominant manner it is due to a defect in the runx 2 gene which is involved in bone formation other conditions that can produce similar symptoms include mandibuloacral dysplasia pyknodysostosis osteogenesis imperfecta and hajdu cheney syndrome treatment includes supportive measures such as a device to protect the skull and dental care it affects about one per million people males and females are equally commonly affected modern descriptions of the condition date to at least 1896 the term is from cleido meaning collarbone cranial meaning head and dysostosis meaning formation of abnormal bone
clemmensen reduction is a chemical reaction described as a reduction of ketones or aldehydes to alkanes using zinc amalgam and hydrochloric acid this reaction is named after erik christian clemmensen a danish chemist the clemmensen reduction the clemmensen reduction is particularly effective at reducing aryl alkyl ketones such as those formed in a friedel crafts acylation with aliphatic or cyclic ketones zinc metal reduction is much more effective the substrate must be unreactive to the strongly acidic conditions of the clemmensen reduction acid sensitive substrates should be reacted in the wolff kishner reduction which utilizes strongly basic conditions a further milder method is the mozingo reduction the oxygen atom is lost in the form of one molecule of water however the reaction is not suitable for substances sensitive to acids also cooh group can t be reduced by this method cooh group can be reduced by treating it with soda lime and then heating in spite of the antiquity of this reaction the mechanism of the clemmensen reduction remains obscure due to the heterogeneous nature of the reaction mechanistic studies are difficult and only a handful of studies have been disclosed proposal mechanisms invoke organozinc intermediates possibly zinc carbenoids either as discrete species or with the organic fragment bound to the metal surface however the corresponding alcohol is not believed to be an intermediate since subjection of alcohols to clemmensen conditions generally does not afford the alkane product
a clerical error is an error on the part of an office worker often a secretary or personal assistant it is a phrase which can also be used as an excuse to deflect blame away from specific individuals such as high powered executives and instead redirect it to the more anonymous clerical staff a clerical error in a legal document is called a scrivener s error
in chemical synthesis click chemistry more commonly called tagging is a class of biocompatible reactions intended primarily to join substrates of choice with specific biomolecules click chemistry is not a single specific reaction but describes a way of generating products that follows examples in nature which also generates substances by joining small modular units in general click reactions usually join a biomolecule and a reporter molecule click chemistry is not limited to biological conditions the concept of a click reaction has been used in pharmacological and various biomimetic applications however they have been made notably useful in the detection localization and qualification of biomolecules click reactions occur in one pot are not disturbed by water generate minimal and inoffensive byproducts and are spring loaded — characterized by a high thermodynamic driving force that drives it quickly and irreversibly to high yield of a single reaction product with high reaction specificity in some cases with both regio and stereo specificity these qualities make click reactions particularly suitable to the problem of isolating and targeting molecules in complex biological environments in such environments products accordingly need to be physiologically stable and any byproducts need to be non toxic for in vivo systems by developing specific and controllable bioorthogonal reactions scientists have opened up the possibility of hitting particular targets in complex cell lysates recently scientists have adapted click chemistry for use in live cells for example using small molecule probes that find and attach to their targets by click reactions despite challenges of cell permeability bioorthogonality background labeling and reaction efficiency click reactions have already proven useful in a new generation of pulldown experiments in which particular targets can be isolated using for instance reporter molecules which bind to a certain column and fluorescence spectrometry in which the fluorophore is attached to a target of interest and the target quantified or located more recently novel methods have been used to incorporate click reaction partners onto and into biomolecules including the incorporation of unnatural amino acids containing reactive groups into proteins and the modification of nucleotides these techniques represent a part of the field of chemical biology in which click chemistry plays a fundamental role by intentionally and specifically coupling modular units to various ends the term click chemistry was coined by k barry sharpless in 1998 and was first fully described by sharpless hartmuth kolb and m g finn of the scripps research institute in 2001
a climate oscillation or climate cycle is any recurring cyclical oscillation within global or regional climate and is a type of climate pattern these fluctuations in atmospheric temperature sea surface temperature precipitation or other parameters can be quasi periodic often occurring on inter annual multi annual decadal multidecadal century wide millennial or longer timescales they are not perfectly periodic and a fourier analysis of the data does not give a sharp spectrum a prominent example is the el niño southern oscillation involving sea surface temperatures along a stretch of the equatorial central and east pacific ocean and the western coast of tropical south america but which affects climate worldwide records of past climate conditions are recovered through geological examination of proxies found in glacier ice sea bed sediment tree ring studies or otherwise
clinical attachment loss cal is the predominant clinical manifestation and determinant of periodontal disease
clinical vampirism more commonly called renfield s syndrome or renfield syndrome is an obsession with drinking blood the earliest formal presentation of clinical vampirism to appear in the psychiatric literature with the psychoanalytic interpretation of two cases was contributed by richard l vanden bergh and john f kelley in 1964 as the authors point out brief and sporadic reports of blood drinking behaviors associated with sexual pleasure have appeared in the psychiatric literature at least since 1892 with the work of austrian forensic psychiatrist richard von krafft ebing many medical publications concerning clinical vampirism can be found in the literature of forensic psychiatry with the unusual behavior reported as one of many aspects of extraordinary violent crimes the behavior has never gained official recognition by the psychiatric profession and is not found in any edition of the international classification of diseases or the diagnostic and statistical manual of mental disorders however in the more colorful era in the history of psychiatry that predated the 1980 s rise of the coded categories of supposedly theory neutral mental disorders in dsm and icd the psychiatric literature was fertile ground for the flourishing of case history reports of uncommon psychiatric syndromes or extraordinary disorders of human behavior that included not only clinical vampirism but also lycanthropy possession stigmata and other unusual phenomena
clinodactyly ˈklaɪnˌoʊdæktɪli from the ancient greek κλίνειν klínein meaning to bend and δάκτυλος dáktulos meaning digit is a medical term describing the curvature of a digit a finger or toe in the plane of the palm most commonly the fifth finger the little finger towards the adjacent fourth finger the ring finger it is a fairly common isolated anomaly which often goes unnoticed but also occurs in combination with other abnormalities in many genetic syndromes
clitic climbing is a phenomenon first identified in romance languages in which a pronominal object of an embedded infinitive appears attached to the matrix verb pronominal objects in romance languages are typically expressed as clitics the following italian example illustrates the phenomenon the object pronoun lo a clitic is attached to the infinitive in the embedded or subordinate clause in 1 a in 1 b the clitic has climbed to the main or matrix clause and is attached to the matrix verb there is no discernible difference in meaning between the two forms clitic climbing is found in almost all romance languages it is notably absent in french
in linguistics clitic doubling or pronominal reduplication is a phenomenon by which clitic pronouns appear in verb phrases together with the full noun phrases that they refer to as opposed to the cases where such pronouns and full noun phrases are in complementary distribution clitic doubling is found in many languages including albanian aromanian macedonian bulgarian degema greek persian romanian somali italian and spanish the conditions on clitic doubling vary from language to language generally depending on well known properties of the objects along the animacy hierarchy allowing requiring or forbidding clitic doubling for different kinds of objects in this regard clitic doubling for objects can be viewed as a species of differential object marking
clitoral erection is a physiological phenomenon where the clitoris becomes enlarged and firm clitoral erection is the result of a complex interaction of psychological neural vascular and endocrine factors and is usually though not exclusively associated with sexual arousal
clitoromegaly or macroclitoris is an abnormal enlargement of the clitoris that is mostly congenital or acquired though deliberately induced clitoris enlargement as a form of female genital body modification is achieved through various uses of anabolic steroids including testosterone and may also be referred to as clitoromegaly clitoromegaly is not the same as normal enlargement of the clitoris seen during sexual arousal
cloacal exstrophy ec is a severe birth defect wherein much of the abdominal organs the bladder and intestines are exposed it often causes the splitting of both male and female genitalia specifically the penis and clitoris respectively and the anus is occasionally sealed cloacal exstrophy is a rare birth defect present in 1 200 000 pregnancies and 1 400 000 live births it is caused by a defect of the ventral body wall — mesodermal migration is inhibited and folding fails
clock angle problems are a type of mathematical problem which involve finding the angles between the hands of an analog clock
clock synchronization is a topic in computer science and engineering that aims to coordinate otherwise independent clocks even when initially set accurately real clocks will differ after some amount of time due to clock drift caused by clocks counting time at slightly different rates there are several problems that occur as a result of clock rate differences and several solutions some being more appropriate than others in certain contexts
clonal interference is a phenomenon in the population genetics of organisms with significant linkage disequilibrium especially asexually reproducing organisms it occurs when two or more different beneficial mutations arise independently in different individuals prior to or in the absence of genetic recombination the mutations cannot be combined into a single more fit genotype but instead compete against each other this typically leads to the loss of one of them confirming that the fate of an advantageous mutation can be determined by other mutations present in the same population in organisms with sexual reproduction two beneficial mutations arising in different organisms can be combined in a descendant this allows evolution to proceed more rapidly a phenomenon known as the hill robertson effect clonal interference is named because an asexual lineage clone with a beneficial mutation which would likely be fixed if it occurred alone may fail to be fixed or even be lost if another beneficial mutation lineage arises in the same population the multiple clones interfere with each other this can also occur in cancer and pre cancer cell lineages within a patient
clonal seborrheic keratosis is a common benign cutaneous condition characterized by a skin lesion with a dull or lackluster surface and with round loosely packed nests of cells seen histologically
clonorchiasis is an infectious disease caused by the chinese liver fluke clonorchis sinensis and two related species clonorchiasis is a known risk factor for the development of cholangiocarcinoma a neoplasm of the biliary system symptoms of opisthorchiasis caused by opisthorchis viverrini and by opisthorchis felineus are indistinguishable from clonorchiasis caused by clonorchis sinensis so the disease by these three parasites should be referred as clonorchiasis
closed head injury is a type of traumatic brain injury in which the skull and dura mater remain intact closed head injuries are the leading cause of death in children under 4 years old and the most common cause of physical disability and cognitive impairment in young people overall closed head injuries and other forms of mild traumatic brain injury account for about 75 of the estimated 1 7 million brain injuries that occur annually in the united states brain injuries such as closed head injuries may result in lifelong physical cognitive or psychological impairment and thus are of utmost concern with regards to public health
the closest pair of points problem or closest pair problem is a problem of computational geometry given n points in metric space find a pair of points with the smallest distance between them the closest pair problem for points in the euclidean plane was among the first geometric problems which were treated at the origins of the systematic study of the computational complexity of geometric algorithms a naive algorithm of finding distances between all pairs of points in a space of dimension d and selecting the minimum requires o dn 2 time it turns out that the problem may be solved in o n log n time in a euclidean space or lp space of fixed dimension d in the algebraic decision tree model of computation the o n log n algorithm is optimal the optimality follows from the observation that the element uniqueness problem with the lower bound of ω n log n for time complexity is reducible to the closest pair problem checking whether the minimal distance is 0 after the solving of the closest pair problem answers the question whether there are two coinciding points in the computational model which assumes that the floor function is computable in constant time the problem can be solved in o n log log n time if we allow randomization to be used together with the floor function the problem can be solved in o n time
in theoretical computer science closest string is the name of an np hard computational problem which tries to find the geometrical center of a set of input strings to understand the word center it is necessary to define a distance between two strings usually this problem is studied with the hamming distance in mind
clostridial necrotizing enteritis cne also called enteritis necroticans and pigbel is an often fatal type of food poisoning caused by a β toxin of clostridium perfringens type c it occurs in some developing countries but was also documented in germany following world war ii the toxin is normally inactivated by certain proteolytic enzymes and by normal cooking but when these protections are impeded the disease emerges
clostridium difficile infection cdi is a symptomatic infection due to the spore forming bacterium clostridium difficile symptoms include watery diarrhea fever nausea and abdominal pain it makes up about 20 of cases of antibiotic associated diarrhea complications may include pseudomembranous colitis toxic megacolon perforation of the colon and sepsis clostridium difficile infection is spread by bacterial spores found within feces surfaces may become contaminated with the spores with further spread occurring via the hands of healthcare workers risk factors for infection include antibiotic or proton pump inhibitors use hospitalization other health problems and older age diagnosis is by stool culture or testing for the bacteria s dna or toxins if a person tests positive but has no symptoms it is known as c difficile colonization rather than an infection prevention is by limiting antibiotic use hand washing and terminal room cleaning in hospital discontinuation of antibiotics may result in resolution of symptoms within three days in about 20 of those infected often the antibiotics metronidazole vancomycin or fidaxomicin will cure the infection retesting after treatment as long as the symptoms have resolved is not recommended as the person may remain colonized recurrence have been reported in up to 25 of people there is tentative evidence that fecal microbiota transplantation and probiotics may decrease the risk of recurrence c difficile infections occur in all areas of the world about 453 000 cases occurred in the united states in 2011 resulting in 29 000 deaths rates of disease globally have increased between 2001 and 2016 women are more often affected than men the bacteria was discovered in 1935 and found to be disease causing in 1978 in the united states healthcare acquired infections increase cost of care by 1 5 billion usd each year
cloud suck is a phenomenon commonly known in paragliding and hang gliding where pilots experience significant lift due to a thermal under the base of cumulus clouds especially towering cumulus and cumulonimbus the vertical extent of a cumulus cloud is a good indicator of the strength of lift beneath it and the potential for cloud suck cloud suck commonly occurs in low pressure weather and in humid conditions cloud suck is typically associated with an increase in thermal updraft velocity near cloud base as a parcel of air lifted in a thermal rises it also cools and water vapour will eventually condense to form a cloud if the parcel rises above the lifted condensation level as the water vapour condenses it releases its latent heat of vaporization thereby increasing the buoyancy of the parcel the updraft is amplified by this latent heat release paraglider pilots have reported being unable to descend in strong cloud suck even after bringing their canopies into deep spiral which would normally result in a rapid vertical descent cloud suck is especially dangerous for paraglider pilots whose maximum speed is less than 30 knots because storm clouds cumulonimbus can expand and develop rapidly over a large area with accompanying large areas of strong lift on 14 february 2007 while practising for a paragliding contest in australia polish borngerman team pilot ewa wiśnierska cieślewicz was sucked into a cumulonimbus cloud climbing at up to 20 m per second 4 000 feet per minute to an altitude of 9 946 m 32 600 feet she lost consciousness due to hypoxia but regained consciousness after 30 minutes to an hour and landed still covered in ice after a three and a half hour flight chinese paraglider pilot he zhongpin died after he was sucked into the same storm system and struck by lightning at 5900 m 19 000 feet his body was found the next day 15 km 9 3 mi from his last known position prior to entering the cloud in 2014 italian paraglider paolo antoniazzi 66 years old retired army general died after being sucked by a thunderstorm compared with hang gliders and paragliders sailplanes have much higher top speeds often over 250 km h and can easily escape powerful cumulonimbus clouds by flying away quickly or by using very effective air brakes a sailplane also has the added benefit of the pilot being able to put the sailplane into a spin to descend rapidly without over speeding cloud suck is also a concern for powered aircraft but usually not a lethal hazard except in extreme weather situations the uss shenandoah the first rigid airship built in the united states and the first in the world to be inflated with helium was lost in a cloud suck accident associated with a squall line at about 6 00 am on 3 september 1925 near ava in northern noble county ohio the shenandoah was suddenly caught in a violent updraft while at an altitude of 2 100 feet rising at the rate of a meter a second at about 6 200 feet the ascent was checked but the ship began to descend when halfway to the ground it was hit by another updraft and began to rise rapidly at an even faster rate ultimately the keel snapped and the ship broke up while still more than a mile above the ground shenandoah s commanding officer and 13 other officers and men were killed twenty nine members of the crew survived the break up although some received serious injuries
a cloudburst is an extreme amount of precipitation in a short period of time sometimes accompanied by hail and thunder that is capable of creating flood conditions a cloudburst can suddenly dump large amounts of water e g 25 mm of precipitation corresponds to 25000 metric tons km 2 1 inch corresponds to 72 300 short tons over one square mile however cloudbursts are infrequent as they occur only via orographic lift or occasionally when a warm air parcel mixes with cooler air resulting in sudden condensation at times a large amount of runoff from higher elevations is mistakenly conflated with a cloudburst the term cloudburst arose from the notion that clouds were akin to water balloons and could burst resulting in rapid precipitation though this idea has since been disproven the term remains in use
clouston s hidrotic ectodermal dysplasia also known as alopecia congenita with keratosis palmoplantaris clouston syndrome fischer – jacobsen – clouston syndrome hidrotic ectodermal dysplasia keratosis palmaris with drumstick fingers and palmoplantar keratoderma and clubbing is caused by mutations in a connexin gene gjb 6 or connexin 30 characterized by scalp hair that is wiry brittle and pale often associated with patchy alopecia
club foot or clubfoot also called congenital talipes equinovarus ctev is a congenital deformity involving one foot or both the affected foot appears to have been rotated internally at the ankle without treatment people with club feet often appear to walk on their ankles or on the sides of their feet however with treatment the vast majority of patients recover completely during early childhood and are able to walk and participate in athletics just as well as patients born without ctev it is a relatively common birth defect occurring in about one in every 1 000 live births approximately half of people with clubfoot have it affect both feet which is called bilateral club foot in most cases it is an isolated disorder of the limbs it occurs in males twice as frequently as in females a condition of the same name appears in some non human animals particularly horses though in that particular case it is more akin to stepping en pointe than sideways
clubbed thumb is a misnomer for stub by thumb known clinically as brachydactyly type d or bdd bdd is a harmless genetic trait characterized by the last bone of one or both thumbs being short and round with an accompanying short and wide nail bed they derive from the dogon tribe residing in africa digital clubbing however is a clinical sign associated with a number of diseases
clubroot is a common disease of cabbages broccoli cauliflower brussels sprouts radishes turnips stocks wallflowers and other plants belonging to the family brassicaceae cruciferae it is caused by plasmodiophora brassicae which was once considered a slime mold but is now put in the group phytomyxea it is the first phytomyxea for which the genome has been sequenced it has as many as thirteen races gall formation or distortion takes place on latent roots and gives the shape of a club or spindle in the cabbage such attacks on the roots cause undeveloped heads or a failure to head at all followed often by decline in vigor or by death it is an important disease affecting an estimated 10 of the total cultured area worldwide historical reports of clubroot date back to the 13 th century in europe in the late 19 th century a severe epidemic of clubroot destroyed large proportions of the cabbage crop in st petersburg the russian scientist mikhail woronin eventually identified the cause of clubroot as a plasmodiophorous organism in 1875 and gave it the name plasmodiophora brassicae in 18 th 19 th and early 20 th century britain clubroot was sometimes called finger and toe fingers and toes anbury or ambury these last two also meaning a soft tumor on a horse the potential of cultural practices to reduce crop losses due to clubroot is limited and chemical treatments to control the fungus are either banned due to environmental regulations or are not cost effective breeding of resistant cultivars therefore is a promising alternative
cluster algebras are a class of commutative rings introduced by fomin and zelevinsky a cluster algebra of rank n is an integral domain a together with some subsets of size n called clusters whose union generates the algebra a and which satisfy various conditions
cluster headache ch is a neurological disorder characterized by recurrent severe headaches on one side of the head typically around the eye there are often accompanying autonomic symptoms during the headache such as eye watering nasal congestion and swelling around the eye typically confined to the side of the head with the pain cluster headache belongs to a group of primary headache disorders classified as the trigeminal autonomic cephalalgias or tacs cluster headache is named after the demonstrated grouping of headache attacks occurring together cluster individuals typically experience repeated attacks of excruciatingly severe unilateral headache pain cluster headache attacks often occur periodically spontaneous remissions may interrupt active periods of pain though about 10 – 15 of chronic ch never remit the cause of cluster headache has not been identified while there is no known cure cluster headaches can sometimes be prevented and acute attacks treated recommended treatments for acute attacks include oxygen or a fast acting triptan primary recommended prevention is verapamil steroids may be used as a transitional treatment and may prevent attack recurrence until preventative treatments take effect the condition affects approximately 0 2 of the general population and men are more commonly affected than women by a ratio of about 2 5 1 to 3 5 1
in natural language processing and information retrieval cluster labeling is the problem of picking descriptive human readable labels for the clusters produced by a document clustering algorithm standard clustering algorithms do not typically produce any such labels cluster labeling algorithms examine the contents of the documents per cluster to find a labeling that summarize the topic of each cluster and distinguish the clusters from each other
clutch performance in sports is the phenomenon of athletes under pressure often in the last minutes of a game to summon strength concentration and whatever else necessary to succeed to perform well and perhaps change the outcome of the game it occurs in basketball hockey football and other sports the opposite is choking failing to perform as needed when under pressure it is a phenomenon that is studied in psychology and in the more specialized area of sport psychology the term gained popularity due to repetitive use among sports commentators particularly baseball announcers consequently a portion of the academic literature is focused on baseball more specifically on clutch hitting and addresses the academic issue of whether it exists or not
cluttering also called tachyphemia or tachyphrasia is a speech and communication disorder characterized by a rapid rate of speech erratic rhythm and poor syntax or grammar making speech difficult to understand
coagulopathy also called a bleeding disorder is a condition in which the blood ’ s ability to coagulate form clots is impaired this condition can cause a tendency toward prolonged or excessive bleeding bleeding diathesis which may occur spontaneously or following an injury or medical and dental procedures of note coagulopathies are sometimes erroneously referred to as clotting disorders a clotting disorder is a predisposition to clot formation thrombus also known as a hypercoagulable state or thrombophilia
a coal ball is a type of concretion varying in shape from an imperfect sphere to a flat lying irregular slab coal balls were formed in carboniferous period swamps and mires when peat was prevented from being turned into coal by the high amount of calcite surrounding the peat the calcite caused it to be turned into stone instead as such despite not actually being made of coal the coal ball owes its name to its similar origins as well as its similar shape with actual coal coal balls often preserve a remarkable record of the microscopic tissue structure of carboniferous swamp and mire plants which would otherwise have been completely destroyed their unique preservation of carboniferous plants makes them valuable to scientists who cut and peel the coal balls to research the geological past in 1855 two english scientists joseph dalton hooker and edward william binney made the first scientific description of coal balls in england and the initial research on coal balls was carried out in europe north american coal balls were discovered and identified in 1922 coal balls have since been found in other countries leading to the discovery of hundreds of species and genera coal balls may be found in coal seams across north america and eurasia north american coal balls are more widespread both stratigraphically and geologically than those in europe the oldest known coal balls date from the namurian stage of the carboniferous they were found in germany and on the territory of former czechoslovakia
coal workers pneumoconiosis cwp also known as black lung disease or black lung is caused by long exposure to coal dust it is common in coal miners and others who work with coal it is similar to both silicosis from inhaling silica dust and to the long term effects of tobacco smoking inhaled coal dust progressively builds up in the lungs and cannot be removed by the body this leads to inflammation fibrosis and in worse cases necrosis coal workers pneumoconiosis severe state develops after the initial milder form of the disease known as anthracosis anthrac — coal carbon this is often asymptomatic and is found to at least some extent in all urban dwellers due to air pollution prolonged exposure to large amounts of coal dust can result in more serious forms of the disease simple coal workers pneumoconiosis and complicated coal workers pneumoconiosis or progressive massive fibrosis or pmf more commonly workers exposed to coal dust develop industrial bronchitis clinically defined as chronic bronchitis i e productive cough for 3 months per year for at least 2 years associated with workplace dust exposure the incidence of industrial bronchitis varies with age job exposure and smoking in nonsmokers who are less prone to develop bronchitis than smokers studies of coal miners have shown a 16 to 17 incidence of industrial bronchitis in 2013 cwp resulted in 25 000 deaths down from 29 000 deaths in 1990
coarctation of the aorta coa or coao also called aortic narrowing is a congenital condition whereby the aorta is narrow usually in the area where the ductus arteriosus ligamentum arteriosum after regression inserts the word “ coarctation ” means narrowing coarctations are most common in the aortic arch the arch may be small in babies with coarctations other heart defects may also occur when coarctation is present typically occurring on the left side of the heart when a patient has a coarctation the left ventricle has to work harder since the aorta is narrowed the left ventricle must generate a much higher pressure than normal in order to force enough blood through the aorta to deliver blood to the lower part of the body if the narrowing is severe enough the left ventricle may not be strong enough to push blood through the coarctation thus resulting in lack of blood to the lower half of the body physiologically its complete form is manifested as interrupted aortic arch
coats ’ disease also known as exudative retinitis or retinal telangiectasis sometimes spelled coates disease is a rare congenital nonhereditary eye disorder causing full or partial blindness characterized by abnormal development of blood vessels behind the retina coats disease can also fall under glaucoma it can have a similar presentation to that of retinoblastoma
cobalt poisoning is intoxication caused by excessive levels of cobalt in the body cobalt is an essential element for health in animals in minute amounts as a component of vitamin b 12 a deficiency of cobalt which is very rare is also potentially lethal leading to pernicious anemia
cobb syndrome is a rare congenital disorder characterized by visible skin lesions with underlying spinal angiomas or arteriovenous malformations avms the skin lesions of cobb syndrome typically are present as port wine stains or angiomas but reports exist of angiokeratomas angiolipomas and lymphangioma circumscriptum the intraspinal lesions may be angiomas or avms and occur at levels of the spinal cord corresponding to the affected skin dermatomes they may in turn produce spinal cord dysfunction and weakness or paralysis the disorder was first described by berenbruch in 1890 but became widely known only after cobb s report in 1915 cobb syndrome is thought to be more common in males and have no racial predilection but only a few dozen cases are known it is believed to be due to a sporadic mutation since parents of affected children usually have no evidence of the disease
the presence of a bezoar is a relatively infrequent disorder that affects the gastrointestinal system it consists of a solid and formed mass trapped in the gastrointestinal system usually in the stomach these can also form in other locations gastric phytobezoars are a form of intestinal blockage and are seen in those with poor gastric motility the preferred treatment of bezoars includes different therapies and or fragmentation to avoid surgery phytobezoars are most common and consist of undigested lignin cellulose tannins celery pumpkin skin grape skins prunes raisins vegetables and fruits phytobezoars can form after eating persimmons and pineapples these are more difficult to treat and are referred to as diospyrobezoars coca cola has been proposed for the treatment of gastric phytobezoars in about 50 of cases studied coca cola alone was found to be effective in gastric phytobezoar dissolution unfortunately this treatment can result in the potential of developing small bowel obstruction in a minority of cases necessitating surgical intervention it is one of many other stomach disorders that can have similar symptoms
cocaine dependence is a psychological desire to use cocaine regularly cocaine overdose may result in cardiovascular and brain damage such as constricting blood vessels in the brain causing strokes and constricting arteries in the heart causing heart attacks the use of cocaine creates euphoria and high amounts of energy if taken in large unsafe doses it is possible to cause mood swings paranoia insomnia psychosis high blood pressure a fast heart rate panic attacks cognitive impairments and drastic changes in personality the symptoms of cocaine withdrawal also known as comedown or crash range from moderate to severe dysphoria depression anxiety psychological and physical weakness pain and compulsive cravings
cocaine intoxication refers to the immediate and deleterious effects of cocaine on the body although cocaine intoxication and cocaine dependence can be present in the same individual these syndromes present with different symptoms
coccidioidomycosis kɒkˌsɪdiɔɪdoʊmaɪˈkoʊsɪs kok sid ee oy doh my koh sis commonly known as cocci valley fever as well as california fever desert rheumatism and san joaquin valley fever is a mammalian fungal disease caused by coccidioides immitis or coccidioides posadasii it is endemic in certain parts of arizona california nevada new mexico texas utah and northern mexico c immitis is a dimorphic saprophytic fungus that grows as a mycelium in the soil and produces a spherule form in the host organism it resides in the soil in certain parts of the southwestern united states most notably in california and arizona it is also commonly found in northern mexico and parts of central and south america c immitis is dormant during long dry spells then develops as a mold with long filaments that break off into airborne spores when it rains the spores known as arthroconidia are swept into the air by disruption of the soil such as during construction farming or an earthquake windstorms may also cause epidemics far from endemic areas in december 1977 a windstorm in an endemic area around arvin ca led to several hundred cases including deaths in non endemic areas hundreds of miles away coccidioidomycosis is a common cause of community acquired pneumonia in the endemic areas of the united states infections usually occur due to inhalation of the arthroconidial spores after soil disruption the disease is not contagious in some cases the infection may recur or become chronic
coccidiosis is a parasitic disease of the intestinal tract of animals caused by coccidian protozoa the disease spreads from one animal to another by contact with infected feces or ingestion of infected tissue diarrhea which may become bloody in severe cases is the primary symptom most animals infected with coccidia are asymptomatic but young or immunocompromised animals may suffer severe symptoms and death while coccidia can infect a wide variety of animals including humans birds and livestock they are usually species specific one well known exception is toxoplasmosis caused by toxoplasma gondii humans may first encounter coccidia when they acquire a young puppy or kitten that is infected other than t gondii the infectious organisms are canine and feline specific and are not contagious to humans unlike the zoonotic diseases
coccydynia is a medical term meaning pain in the coccyx or tailbone area usually brought on by sitting too abruptly
a coccyx fracture is a fracture of the coccyx commonly called a broken tailbone the coccyx is located at the base of the spine under the sacrum it is the last section of the ape vertebral column most commonly in humans it comprises 3 to 5 fused or more rarely separate vertebrae and is approximately 4 to 10 cm in length the coccyx is attached to the sacrum by a fibrocartilaginous joint called the sacrococcygeal symphysis allowing for some but little movement
cock s peculiar tumour is a sebaceous cyst linked growth that can resemble a squamous cell carcinoma the name is given after a 19 th century english surgeon edward cock the proliferating cyst is usually solitary but it often arises from a simple trichilemmal cysts in the hair follicle epithelium and these are multiple in 70 of cases they are most commonly found on the scalp where the proliferating trichilemmal cyst will grow to a large size and ulcerate chronic inflammation can cause the cyst to take the form of a granuloma this granuloma mimics a squamous cell carcinoma both clinically and histologically and these ulcerating solitary cysts are called cock s peculiar tumour chronic inflammation causes the cyst to take the form of a granuloma this granuloma mimics a squamous cell tumour hence it is a misnomer it is not a tumour but looks like a tumour the most common sites are the ones where one can find hairs these are scalp and scrotum
cockayne syndrome cs also called neill dingwall syndrome is a rare fatal autosomal recessive neurodegenerative disorder characterized by growth failure impaired development of the nervous system abnormal sensitivity to sunlight photosensitivity eye disorders and premature aging failure to thrive and neurological disorders are criteria for diagnosis while photosensitivity hearing loss eye abnormalities and cavities are other very common features problems with any or all of the internal organs are possible it is associated with a group of disorders called leukodystrophies which are conditions characterized by degradation of neurological white matter the underlying disorder is a defect in a dna repair mechanism unlike other defects of dna repair patients with cs are not predisposed to cancer or infection cockayne syndrome is a rare but destructive disease usually resulting in death within the first or second decade of life the mutation of specific genes in cockayne syndrome is known but the widespread effects and its relationship with dna repair is yet to be well understood it is named after english physician edward alfred cockayne 1880 – 1956 who first described it in 1936 and re described in 1946 neill dingwall syndrome was named after mary m dingwall and catherine a neill these women described the case of two brothers with cockayne syndrome and asserted it was the same disease described by cockayne in their article the women contributed to the symptoms of the disease through their discovery of calcifications in the brain they also compared cockayne syndrome to what is now known as hutchinson – gilford progeria syndrome hgps then called progeria due to the advanced aging that characterizes both disorders
cockscomb cervix is the condition wherein as the name suggests the cervix of the uterus is shaped like a cockscomb about one third of women born to diethylstilbestrol treated mothers i e in utero exposure develop a cockscomb cervix enlarged folds or ridges of cervical stroma fibrous tissues and epithelium constitute a cockscomb cervix similarly cockscomb polyps lining the cervix are usually considered or grouped into the same overarching description it is in and of itself considered a benign abnormality its presence however is usually indicative of des exposure and as such women who experience these abnormalities should be aware of their increased risk of associated pathologies
the cocktail party effect is the phenomenon of being able to focus one s auditory attention on a particular stimulus while filtering out a range of other stimuli much the same way that a partygoer can focus on a single conversation in a noisy room this effect is what allows most people to tune into a single voice and tune out all others it may also describe a similar phenomenon that occurs when one may immediately detect words of importance originating from unattended stimuli for instance hearing one s name in another conversation
in mathematics in the branch of differential geometry the cocurvature of a connection on a manifold is the obstruction to the integrability of the vertical bundle
in distributed computing code mobility is the ability for running programs code or objects to be migrated or moved from one machine or application to another this is the process of moving mobile code across the nodes of a network as opposed to distributed computation where the data is moved it is common practice in distributed systems to require the movement of code or processes between parts of the system instead of data examples of code mobility include scripts downloaded over a network for example javascript vbscript java applets activex controls flash animations shockwave movies and xtras and macros embedded within microsoft office documents
a code of silence is a condition in effect when a person opts to withhold what is believed to be vital or important information voluntarily or involuntarily the code of silence is usually either kept because of threat of force or danger to oneself or being branded as a traitor or an outcast within the unit or organization as the experiences of the police whistleblower frank serpico illustrates police are known to have a well developed blue code of silence the code of silence was famously practiced in irish american neighborhoods in boston massachusetts such as charlestown south boston and somerville dan goldberg and danny ben moshe won australia ’ s most prestigious journalism award the walkley documentary award for “ code of silence ” which covers the fight for an investigation into allegations of child sex abuse at yeshivah college an all male orthodox jewish school it portrays the experiences of an orthodox jewish father and his son after the son breaks the code of silence in melbourne s orthodox community and goes public with his story of being sexually abused as a student an orthodox jewish concept of mesirah forbids jews from reporting crimes to civil authorities and keeping them with the jewish community instead a more famous example of the code of silence is omertà italian omertà from the latin humilitas humility or modesty the mafia code of silence
coeliac disease also spelled celiac disease is an autoimmune disorder affecting primarily the small intestine that occurs in people who are genetically predisposed classic symptoms include gastrointestinal problems such as chronic diarrhoea abdominal distention malabsorption loss of appetite and among children failure to grow normally this often begins between six months and two years of age non classic symptoms are the most common especially in people older than two years there may be mild or absent gastrointestinal symptoms a wide number of symptoms involving any part of the body or no obvious symptoms coeliac disease was first described in childhood however it may develop at any age it is associated with other autoimmune diseases such as diabetes mellitus type 1 and thyroiditis among others coeliac disease is caused by a reaction to gluten which are various proteins found in wheat and in other grains such as barley and rye moderate quantities of oats free of contamination with other gluten containing grains are usually tolerated but problems may depend on the type consumed upon exposure to gluten an abnormal immune response may lead to the production of several different autoantibodies that can affect a number of different organs in the small bowel this causes an inflammatory reaction and may produce shortening of the villi lining the small intestine villous atrophy this affects the absorption of nutrients frequently leading to anaemia diagnosis is typically made by a combination of blood antibody tests and intestinal biopsies helped by specific genetic testing making the diagnosis is not always straightforward frequently the autoantibodies in the blood are negative and many people have only minor intestinal changes with normal villi people may have severe symptoms and be investigated for years before a diagnosis is achieved increasingly the diagnosis is being made in people without symptoms as a result of screening while the disease is caused by a permanent intolerance to wheat proteins it is usually classified as different from the other forms of wheat allergy the only known effective treatment is a strict lifelong gluten free diet which leads to recovery of the intestinal mucosa improves symptoms and reduced risk of developing complications in most people if untreated it may result in cancers such as intestinal lymphoma and a slight increased risk of early death rates vary between different regions of the world from as few as 1 in 300 to as many as 1 in 40 with an average of between 1 in 100 and 1 in 170 people in developed countries it is estimated that five out of six cases 83 remain undiagnosed usually because of non classic minimal or absent complaints coeliac disease is slightly more common in women than in men the term coeliac is from the greek κοιλιακός koiliakós abdominal and was introduced in the 19 th century in a translation of what is generally regarded as an ancient greek description of the disease by aretaeus of cappadocia
coenurosis a k a caenurosis and coenuriasis gid or sturdy in the vernacular is a parasitic infection that develops in the intermediate hosts of some tapeworm species taenia multiceps t serialis t brauni or t glomerata and are caused by the coenurus the larval stage of these worms this disease occurs mainly in sheep and other ungulates but occasionally can occur in humans too by accidental ingestion of worms eggs adult worms of these species develop in the small intesine of the definitive hosts dogs foxes and other canids causing a disease from the group of taeniasis humans cannot be definitive hosts for these species of tapeworms
coenurosis is a parasitic infection that results when humans ingest the eggs of dog tapeworm species taenia multiceps t serialis t brauni or t glomerata it is important to distinguish that there is a very significant difference between intestinal human tapeworm infection and human coenurosis humans are the definitive hosts for some tapeworm species the most common being t saginata and t solium pork and beef tapeworms this means that these species can develop into full grown reproductively capable adult worms within the human body people infected with these species have a tapeworm infection in contrast the four species that cause human coenurosis can only grow into mature reproductively capable worms inside their definitive hosts canids such as dogs wolves foxes and coyotes humans who ingest eggs from any of these four species of taenia become intermediate hosts or places where the eggs can mature into larvae but not into adult worms when humans ingest these eggs the eggs develop into tapeworm larvae that group within cysts known as coenuri which can be seen in the central nervous system muscles and subcutaneous tissues of infected humans people with coenurosis do not develop a tapeworm infection because the larvae of coenurosis causing parasites cannot develop into worms inside of humans
coenzyme q 10 deficiency is a deficiency of coenzyme q 10 it can be associated with coq 2 aptx pdss 2 pdss 1 cabc 1 and coq 9 some forms may be more treatable than other mitochondrial diseases
in mathematics a coercive function is a function that grows rapidly at the extremes of the space on which it is defined depending on the contextdifferent exact definitions of this idea are in use
in physics a coffee ring is a pattern left by a puddle of particle laden liquid after it evaporates the phenomenon is named for the characteristic ring like deposit along the perimeter of a spill of coffee it is also commonly seen after spilling red wine the mechanism behind the formation of these and similar rings is known as the coffee ring effect or in some instances the coffee stain effect or simply ring stain
coffin – lowry syndrome is a genetic disorder that is x linked dominant and which causes severe mental problems sometimes associated with abnormalities of growth cardiac abnormalities kyphoscoliosis as well as auditory and visual abnormalities
coffin – siris syndrome is a rare genetic disorder that causes developmental delays and absent fifth finger and toe nails synonyms include dwarfism onychodysplasia fifth digit syndrome mental retardation with hypoplastic 5 th fingernails and toenails and short stature onychodysplasia there had been 31 reported cases by 1991 the numbers of occurrence since then has grown and is reported to be around 80 the differential includes nicolaides – baraitser syndrome
cogan syndrome is a rare disorder characterized by recurrent inflammation of the front of the eye the cornea and often fever fatigue and weight loss episodes of dizziness and hearing loss it can lead to deafness or blindness if untreated the classic form of the disease was first described by d g cogan in 1945
cognitive bias in animals is a pattern of deviation in judgment whereby inferences about other animals and situations may be affected by irrelevant information or emotional states it is sometimes said that animals create their own subjective social reality from their perception of the input in humans for example an optimistic or pessimistic bias might affect ones answer to the question is the glass half empty or half full to explore cognitive bias one might train an animal to expect that a positive event follows one stimulus and that a negative event follows another stimulus for example on many trials if the animal presses lever a after a 20 hz tone it gets a highly desired food but a press on lever b after a 10 hz tone yields bland food the animal is then offered both levers after an intermediate test stimulus e g a 15 hz tone the hypothesis is that the animal s mood will bias the choice of levers after the test stimulus if positive it will tend to choose lever a if negative it will tend to choose lever b the hypothesis is tested by manipulating factors that might affect mood – for example the type of housing the animal is kept in cognitive biases have been shown in a wide range of species including rats dogs rhesus macaques sheep chicks starlings and honeybees
cognitive deficit or cognitive impairment is an inclusive term to describe any characteristic that acts as a barrier to the cognition process the term may describe deficits in global intellectual performance as with intellectual disabilities it may describe specific deficits in cognitive abilities learning disorders dyslexia or it may describe drug induced cognitive memory impairment such as that seen with alcohol glucocorticoids and the benzodiazepines it usually refers to a durable characteristic as opposed to altered level of consciousness which may be acute and reversible cognitive deficits may be congenital or caused by environmental factors such as brain injuries neurological disorders or mental illness
in psychology cognitive dissonance is the mental stress or discomfort experienced by an individual who holds two or more contradictory beliefs ideas or values at the same time performs an action that is contradictory to their beliefs ideas or values or is confronted by new information that conflicts with existing beliefs ideas or values leon festinger s theory of cognitive dissonance focuses on how humans strive for internal consistency an individual who experiences inconsistency tends to become psychologically uncomfortable and is motivated to try to reduce this dissonance as well as actively avoid situations and information likely to increase it
cognitive distortions are exaggerated or irrational thought patterns that are believed to perpetuate the effects of psychopathological states especially depression and anxiety psychiatrist aaron t beck laid the groundwork for the study of these distortions and his student david d burns continued research on the topic most notably burns 1989 book the feeling good handbook presented information on these thought patterns along with a proposal of how to eliminate them cognitive distortions are thoughts that cognitive therapists believe cause individuals to perceive reality inaccurately these thinking patterns often are said to reinforce negative thoughts or emotions cognitive distortions tend to interfere with the way a person perceives an event because the way a person feels intervenes with how they think these distorted thoughts can feed negative emotions and lead an individual affected by cognitive distortions towards an overall negative outlook on the world and consequently a depressive or anxious mental state
object recognition is the ability to perceive an object s physical properties such as shape colour and texture and apply semantic attributes to the object which includes the understanding of its use previous experience with the object and how it relates to others regardless of an objects position or illumination humans possess the ability to effectively identify and label an object humans are one of the few species that possess the ability of invariant visual object recognition both “ front end ” and “ back end ” processing are required for a species to be able to recognize objects at varying distances angles lighting etc …
a cognitive shift is a psychological phenomenon most often experienced by individuals when undergoing new experiences including religious experiences using psychedelic drugs or suffering from mental disorders such as schizophrenia or bipolar disorder also known as manic depressive syndrome during a cognitive shift one experiences a change in how their conscious mind and unconscious mind communicate with each other the result can be a wide range of feelings from euphoria to panic
cognitive slippage is a symptom of several psychiatric diseases and mental disorders associated with cognition and formal thought disorders it is not associated with a lower level of intelligence it is manifested in patterns of speech where categories and lists become overly broad as concepts unrelated at first glance become related through tangential connections an example of cognitive slippage might be as follows list some types of cars let s see there s ford chevrolet toyota japan rising sun hiroshima atomic bomb enola gay oh and miata the inclusion of extraneous items in the listing is evidence of the cognitive slippage while the concepts such as toyota japan rising sun etc are all related the relation is no longer defined by the initial prompt the cognitive slippage however causes the inability to disregard these extraneous connections and results in patterns of speech and association as seen here in contrast another disorder of speech word salad is even more disorganized than the loose associations of cognitive slippage cognitive slippage is characterized as the mildest symptom of individuals with schizophrenia schizophrenia is a psychiatric illness that affects every aspect of a patient s life
cohen syndrome also known as pepper syndrome or cervenka syndrome named after michael cohen william pepper and jaroslav cervenka who researched the illness is a genetic disorder
coil noise or coil whine is a phenomenon in electronics which produces undesirable audible sound in magnetic resonance imaging coil noise is that part of total system noise attributed to the receiving coil due to its non zero temperature
in polymer physics the coil – globule transition is the collapse of a macromolecule from an expanded coil state through an ideal coil state to a collapsed globule state or vice versa the coil – globule transition is of importance in biology due to the presence of coil globule transitions in biological macromolecules such as proteins and dna it is also analogous with the swelling behavior of a crosslinked polymer gel and is thus of interest in biomedical engineering for controlled drug delivery a particularly prominent example of a polymer possessing a coil globule transition of interest in this area is that of poly n isopropylacrylamide pnipaam
the coin problem also referred to as the frobenius coin problem or frobenius problem after the mathematician ferdinand frobenius is a mathematical problem that asks for the largest monetary amount that cannot be obtained using only coins of specified denominations for example the largest amount that cannot be obtained using only coins of 3 and 5 units is 7 units the solution to this problem for a given set of coin denominations is called the frobenius number of the set there is an explicit formula for the frobenius number when there are only two different coin denominations x and y xy − x − y if the number of coin denominations is three or more no explicit formula is known but for any fixed number of coin denominations there is an algorithm computing the frobenius number in polynomial time in the logarithms of the coin denominations forming an input no known algorithm is polynomial time in the number of coin denominations and the general problem where the number of coin denominations may be as large as desired is np hard
in parasitology coinfection ˌkoʊɪnˈfɛkʃən is the simultaneous infection of a host by multiple pathogen species in virology coinfection includes simultaneous infection of a single cell by two or more virus particles an example is the coinfection of liver cells with hepatitis b virus and hepatitis d virus which can arise incrementally by initial infection followed by superinfection global prevalence or incidence of coinfection among humans is unknown but it is thought to be commonplace sometimes more common than single infection coinfection with helminths affects around 800 million people worldwide coinfection is of particular human health importance because pathogen species can interact within the host the net effect of coinfection on human health is thought to be negative interactions can have either positive or negative effects on other parasites under positive parasite interactions disease transmission and progression are enhanced and this is also known as syndemism negative parasite interactions include microbial interference when one bacterial species suppresses the virulence or colonisation of other bacteria such as pseudomonas aeruginosa suppressing pathogenic staphylococcus aureus colony formation the general patterns of ecological interactions between parasite species are unknown even among common coinfections such as those between sexually transmitted infections however network analysis of a food web of coinfection in humans suggests that there is greater potential for interactions via shared food sources than via the immune system a globally common coinfection involves tuberculosis and hiv in some countries up to 80 of tuberculosis patients are also hiv positive the potential for dynamics of these two infectious diseases to be linked has been known for decades other common examples of coinfections are aids which involves coinfection of end stage hiv with opportunistic parasites and polymicrobial infections like lyme disease with other diseases
a colambre is a wine skin whose origin comes from the 16 th century in spanish it is known as bota a word used by cervantes in don quixote on the other hand lord colambre is the main character of the absentee a novel written in english in the 18 th century by maria edgeworth
for the infectious disease see common cold for other uses see cold disambiguation cold is the presence of low temperature especially in the atmosphere in common usage cold is often a subjective perception a lower bound to temperature is absolute zero defined as 0 00 k on the kelvin scale an absolute thermodynamic temperature scale this corresponds to − 273 15 ° c on the celsius scale − 459 67 ° f on the fahrenheit scale and 0 00 ° r on the rankine scale since temperature relates to the thermal energy held by an object or a sample of matter which is the kinetic energy of the random motion of the particle constituents of matter an object will have less thermal energy when it is colder and more when it is hotter if it were possible to cool a system to absolute zero all motion of the particles in a sample of matter would cease and they would be at complete rest in this classical sense the object would be described as having zero thermal energy microscopically in the description of quantum mechanics however matter still has zero point energy even at absolute zero because of the uncertainty principle
cold air damming or cad is a meteorological phenomenon that involves a high pressure system anticyclone accelerating equatorward east of a north south oriented mountain range due to the formation of a barrier jet behind a cold front associated with the poleward portion of a split upper level trough initially a high pressure system moves poleward of a north south mountain range once it sloshes over poleward and eastward of the range the flow around the high banks up against the mountains forming a barrier jet which funnels cool air down a stretch of land east of the mountains the higher the mountain chain the deeper the cold air mass becomes lodged to its east and the greater impediment it is within the flow pattern and the more resistant it becomes to intrusions of milder air as the equatorward portion of the system approaches the cold air wedge persistent low cloudiness such as stratus and precipitation such as drizzle develop which can linger for long periods of time as long as ten days the precipitation itself can create or enhance a damming signature if the poleward high is relatively weak if such events accelerate through mountain passes dangerously accelerated mountain gap winds can result such as the tehuantepecer and santa ana winds these events are seen commonly in the northern hemisphere across central and eastern north america south of the alps in italy and near taiwan and korea in asia events in the southern hemisphere have been noted in south america east of the andes
cold agglutinin disease is an autoimmune disease characterized by the presence of high concentrations of circulating antibodies usually igm directed against red blood cells it is a form of autoimmune hemolytic anemia specifically one in which antibodies only bind red blood cells at low body temperatures typically 28 31 ° c it was first described in 1957
the cold drop spanish gota fría is a weather phenomenon often occurring in the spanish autumn it is experienced particularly along the western mediterranean and as such most frequently affects the east coast of spain it is a closed upper level low which has become completely displaced cut off from basic westerly current and moves independently of that current cutoff lows may remain nearly stationary for days or on occasion may move westward opposite to the prevailing flow aloft i e retrogression the term is also used to describe the meteorological phenomenon associated in spain it appears when a front of very cold polar air a jet stream advances slowly over western europe at high altitude normally 5 – 9 km or 3 – 5 5 mi
cold inflation pressure is the inflation pressure of tires before the car is driven and the tires warmed up recommended cold inflation pressure is displayed on the owner s manual and on the placard or sticker attached to the vehicle door edge pillar glovebox door or fuel filler flap drivers are encouraged to make sure their tires are adequately inflated as suboptimal tire pressure can greatly reduce fuel economy increase emissions increased wear on the edges of the tire surface and can lead to premature failure of the tire excessive pressure on the other hand may lead to impact breaks decrease braking performance and cause uneven wear i e greater wear on the center part of the tire surface tire pressure is commonly measured in psi in the imperial and us customary systems bar which is deprecated but accepted for use with si or the kilopascal kpa which is an si unit ambient temperature affects the cold tire pressure absolute cold tire pressure gauge pressure plus atmospheric pressure varies directly with the absolute temperature measured in kelvins from physics the ideal gas law states that pv nrt where p is absolute pressure t is absolute temperature kelvin v is the volume assumed to be relatively constant in the case of a tire and nr is constant for a given number of molecules of gas to understand this assume the tire was filled when it was 300 kelvin 80 degrees fahrenheit if the temperature varies 10 i e by 30 kelvin also 30 celsius degrees or 54 fahrenheit degrees the pressure varies 10 so if the tire was filled at 80 f to 32 psi or 47 psi absolute when we add atmospheric pressure the change would be 4 7 psi for this 30 celsius degree change or 16 psi per celsius degree or 1 psi per fahrenheit degree or 1 psi for every 10 fahrenheit degrees using si units that would be 1 1 kpa per kelvin hence for a tire filled to 32 psi the approximation usually made is that within the range of normal atmospheric temperatures and pressures tire pressure increases 1 psi for each 10 fahrenheit degree increase in temperature or conversely decreases 1 psi for each 10 fahrenheit degree decrease in temperature andin si units tire pressure increases 1 1 kpa for each 1 celsius degree increase in temperature or conversely decreases 1 1 kpa for each 1 celsius degree decrease in temperature for tires that need inflation greater than 32 psi it might be easier to use a rule of thumb of 2 pressure change for a change of 10 degrees fahrenheit from the table below one can see that these are only approximations
cold sensitivity or cold intolerance is unusual discomfort felt by some people when in a cool environment there is much variation in the sensitivity to cold experienced by different people with some putting on many layers of clothing while others in the same environment feel comfortable in one layer cold sensitivity may be a symptom of hypothyroidism anemia fibromyalgia or vasoconstriction according to article sauna there may also be differences in people in the expression of uncoupling proteins thus affecting their amount of thermogenesis mental activity may also play a factor in perceived temperature
cold start is a potential problem in computer based information systems which involve a degree of automated data modelling specifically it concerns the issue that the system cannot draw any inferences for users or items about which it has not yet gathered sufficient information
cold urticaria essentially meaning cold hives is an allergy where hives urticaria or large red welts form on the skin after exposure to a cold stimulus the welts are usually itchy and often the hands and feet will become itchy and swollen as well hives vary in size from about 7 mm in diameter to as big as about 27 mm diameter or larger the disease is classified as chronic when hives appear for longer than 6 weeks they can last for life though their course is often unpredictable this disorder or perhaps two disorders with the same clinical manifestations can be inherited familial cold urticaria or acquired primary acquired cold urticaria the acquired form is most likely to occur between ages 18 – 25 although it can occur as early as 5 years old in some cases
a cold wave known in some regions as a cold snap is a weather phenomenon that is distinguished by a cooling of the air specifically as used by the u s national weather service a cold wave is a rapid fall in temperature within a 24 hour period requiring substantially increased protection to agriculture industry commerce and social activities the precise criterion for a cold wave is determined by the rate at which the temperature falls and the minimum to which it falls this minimum temperature is dependent on the geographical region and time of year in the united states a cold spell is defined as the national average high temperature dropping below 18 ° f − 8 ° c
colic from greek κολικός kolikos relative to the colon or cholic is a form of pain that starts and stops abruptly it occurs due to muscular contractions of a hollow tube colon ureter gall bladder etc in an attempt to relieve an obstruction by forcing content out it may be accompanied by vomiting and sweating types include baby colic a condition usually in infants characterized by incessant crying renal colic a pain in the flank characteristic of kidney stones biliary colic blockage by a gallstone of the common bile duct or cystic duct horse colic a potentially fatal condition experienced by horses caused by intestinal displacement or blockage devon colic an affliction caused by lead poisoning painter s colic or lead poisoning
colitis pl colitides is an inflammation of the colon colitis may be acute and self limited or chronic i e persistent and broadly fits into the category of digestive diseases in a medical context the label colitis without qualification is used if the cause of the inflammation in the colon is undetermined for example colitis may be applied to crohn s disease at a time when the diagnosis is unknown or the context is clear for example an individual with ulcerative colitis is talking about their disease with a physician who knows the diagnosis
collaboration horizontale collaboration féminine or collaboration sentimentale the french adjective sentimentale can be translated as pertaining to a romantic relationship was the supposed sexual intercourse that some french women had with members of the german invasion force after the battle of france in 1940 this started to be considered a form of collaboration ca june 6 1944 the start of la libération after the war throughout france women accused of collaboration were shaved bald in many of the ca 20 000 cases the women in question had only performed professional services for the occupying germans rather than being engaged in sexual relationships with them collaboration horizontale is believed to have produced 200 000 french babies with german fathers since 2009 germany offers these children of the other bank of the rhine citizenship after french foreign minister bernard kouchner had lobbied for their recognition
collagen induced arthritis cia is a condition induced in mice or rats to study rheumatoid arthritis cia is induced in mice by injecting them with an emulsion of complete freund s adjuvant and type ii collagen in rats only one injection is needed mice are normally injected twice
collagenous colitis is an inflammatory bowel disease affecting the colon specifically with peak incidence in the 5 th decade of life affecting women more than men its clinical presentation involves watery diarrhea in the absence of rectal bleeding it is often classified under the umbrella entity microscopic colitis that it shares with a related condition lymphocytic colitis
collagenous fibroma also known as desmoplastic fibroblastoma is a slow growing deep set benign fibrous tumor usually located in the deep subcutis fascia aponeurosis or skeletal muscle of the extremities limb girdles or head and neck regions
collagenous spherulosis also mucinous spherulosis and simply spherulosis is a benign finding in breast pathology it is almost always an incidental finding though it is occasionally associated with calcifications which may lead to a biopsy
collapsible flow is a phenomenon that occurs in steady flow in tubes with significant distensibility or the capability of swelling or stretching under conditions of lower internal pressure relative to pressure outside the tube such conditions occur rarely in industrial applications but are very common in biological studies such as blood flow in veins and air flow in lungs when a flow is driven through a deformable channel or tube interactions between fluid mechanical and elastic forces can lead to a variety of biologically significant phenomena including nonlinear pressure drop flow rate relations wave propagation and the generation of instabilities understanding the physical origin and nature of these phenomena remains a significant experimental analytical and computational challenge involving unsteady flows at low or high reynolds numbers large amplitude fluid structure interactions free surface flows and intrinsically 2 d or 3 d motion whereas frequently the internal flow involves a single fluidphase albeit often of a complex biological fluid such as blood in many instances the presence of two or more distinct flowing phases is of primary importance as is the case for air liquid flows in peripheral lung airways for example
in medicine collateralization also vessel collateralization and blood vessel collateralization is the growth of a blood vessel or several blood vessels that serve the same end organ or vascular bed as another blood vessel that cannot adequately supply that end organ or vascular bed sufficiently coronary collateralization is considered a normal response to hypoxia and may be induced under some circumstances by exercise it is considered to be protective collateral or anastomotic blood vessels also exist even when blood supply is adequate to an area and these blood vessels are often taken advantage of in surgery some notable areas where this occurs include the abdomen rectum knee shoulder and head
collecting duct carcinoma cdc also known as bellini duct carcinoma is a type of kidney cancer that originates in the papillary duct of the kidney it is rare accounting for 1 3 of all kidney cancers it is also recently described a 2002 review found just 40 case reports worldwide previously due to its location cdc was commonly diagnosed as renal cell carcinoma or a subtype of renal cell carcinoma however cdc does not respond well to chemotherapy drugs used for renal cell carcinoma and progresses and spreads more quickly
a collective trauma is a traumatic psychological effect shared by a group of people of any size up to and including an entire society traumatic events witnessed by an entire society can stir up collective sentiment often resulting in a shift in that society s culture and mass actions well known collective traumas include the holocaust the armenian genocide slavery in the united states the atomic bombings of hiroshima and nagasaki the trail of tears the assassination of john f kennedy in the united states the ms estonia in sweden the september 11 2001 attacks in the united states and various others collective traumas have been shown to play a key role in group identity formation see law of common fate during world war ii a us submarine the uss puffer ss 268 came under several hours of depth charge attack by a japanese surface vessel until the ship became convinced the submarine had somehow escaped psychological studies later showed that crewmen transferred to the submarine after the event were never accepted as part of the team later us naval policy was changed so that after events of such psychological trauma the crew would be dispersed to new assignments rehabilitation of survivors becomes extremely difficult when entire nation has experienced such severe traumas as war genocide torture massacre etc treatment is hardly effective when everybody is traumatized trauma remains chronic and would reproduce itself as long as social causes are not addressed and perpetrators continue to enjoy impunity the whole society may suffer from an everlasting culture of pain 1 during liberation war in algeria the algerian psychiatrist frantz omar fanon found his practice of treatment of native algerians ineffective due to the continuation of the horror of a colonial war he emphasized about the social origin of traumas joined the liberation movement and urged oppressed people to purge themselves of their degrading traumas through their collective liberation struggle he made the following remarks in his letter of resignation as the head of the psychiatry department at the blida joinville hospital in algeria if psychiatry is the medical technique that aims to enable man no longer to be a stranger to his environment i owe it to myself to affirm that the arab permanently an alien in his own country lives in a state of absolute depersonalization 2 inculcation of horror and anxiety through widespread torture massacre genocide and similar coercive measures has happened frequently in human history there are plenty of examples in our modern history tyrants have always used their technique of “ psychological artillery in an attempt to cause havoc and confusion in the minds of people and hypnotize them with intimidation and cynicism the result is a collective trauma that will pass through generations there is no magic formula of rehabilitation collective trauma can be alleviated through cohesive and collective efforts such as recognition remembrance solidarity communal therapy and massive cooperation
a colles fracture is a fracture of the distal radius in the forearm with dorsal posterior and radial displacement of the wrist and hand the fracture is sometimes referred to as a dinner fork or bayonet deformity due to the shape of the resultant forearm colles fractures are often seen in people with osteoporosis
the collie sub basin is a pocket of permian sedimentary rocks with an area of 225 km ² enclosed within much older archean rocks of the yilgarn craton near the town of collie in southwestern western australia once considered a unique basin this area along with the smaller wilga and boyup sub basins to the south are now classified as outliers of the perth basin separated from the main area by ancient earth movements and erosion the collie sub basin contains significant coal reserves currently being mined mainly for electricity generation
collie eye anomaly cea is a congenital inherited bilateral eye disease of dogs which affects the retina choroid and sclera it can be a mild disease or cause blindness cea is caused by a simple autosomal recessive gene defect there is no treatment
the collins oxidation is an organic reaction for the oxidation of primary alcohols to aldehydes it is distinguished from other chromium oxide based oxidations by the use of collins reagent a complex of chromium vi oxide with pyridine in dichloromethane
a colloid cyst is a cyst containing gelatinous material in the brain it is almost always found just posterior to the foramen of monro in the anterior aspect of the third ventricle originating from the roof of the ventricle because of its location it can cause obstructive hydrocephalus and increased intracranial pressure a colloid cysts represent 0 5 1 of intracranial tumors symptoms can include headache vertigo memory deficits diplopia behavioral disturbances and in extreme cases sudden death intermittency of symptoms is characteristic of this lesion untreated pressure caused by these cysts can result in brain herniation colloid cyst symptoms have been associated with 4 variables cyst size cyst imaging characteristics ventricular size and patient age the developmental origin is unclear though they may be of endodermal origin which would explain the mucin producing ciliated cell type these cysts can be surgically resected and opinion is divided about the advisability of this
colloid nodules also known as adenomatous nodules or colloid nodular goiter are benign noncancerous enlargement of thyroid tissue although they may grow large and there may be more than one they are not malignant and they will not spread beyond the thyroid gland colloid nodules are the most common kind of thyroid nodule
colloid vibration current is an electroacoustic phenomenon that arises when ultrasound propagates through a fluid that contains ions and either solid particles or emulsion droplets the pressure gradient in an ultrasonic wave moves particles relative to the fluid this motion disturbs the double layer that exists at the particle fluid interface the picture illustrates the mechanism of this distortion practically all particles in fluids carry a surface charge this surface charge is screened with an equally charged diffuse layer this structure is called the double layer ions of the diffuse layer are located in the fluid and can move with the fluid fluid motion relative to the particle drags these diffuse ions in the direction of one or the other of the particle s poles the picture shows ions dragged towards the left hand pole as a result of this drag there is an excess of negative ions in the vicinity of the left hand pole and an excess of positive surface charge at the right hand pole as a result of this charge excess particles gain a dipole moment these dipole moments generate an electric field that in turn generates measurable electric current this phenomenon is widely used for measuring zeta potential in concentrated colloids
colluvium filled bedrock hollows are the cause of many shallow earth landslides in steep mountainous terrain they can form as a u or a v shaped trough as local bedrock variations reveal areas in the bedrock which are more prone to weathering than other locations on the slope as the weathered bedrock turns to soil there is a greater elevation difference between the soil level and the hard bedrock with the introduction of water and the thick soil there is less cohesion and the soil flows out in a landslide with every landslide more bedrock is scoured out and the hollow becomes deeper after time colluvium fills the hollow and the sequence starts again
a coloboma from the greek koloboma meaning defect is a hole in one of the structures of the eye such as the iris retina choroid or optic disc the hole is present from birth and can be caused when a gap called the choroid fissure which is present during early stages of prenatal development fails to close up completely before a child is born the classical description in medical literature is of a key hole shaped defect a coloboma can occur in one eye unilateral or both eyes bilateral most cases of coloboma affect only the iris people with coloboma may have no vision problems or may be blind depending on severity it affects less than one in every 10 000 births
coloboma of optic nerve is a rare defect of the optic nerve that causes moderate to severe visual field defects
see also history of perth western australia this article details the colonial town plans that guided the development of the initial perth town site in the swan river colony this is now the central city area of the perth metropolitan region the 1829 town plan of perth western australia was an elongated grid pattern that reflected the urban planning principles of the day and was typical of colonial williamsburg 1699 and the edinburgh new town 1768 the plan expressed enlightenment principles and the ideal of a town conceived as the seat of power within a large and productive agricultural hinterland it has remained relatively unchanged to the present day
colony collapse disorder ccd is the phenomenon that occurs when the majority of worker bees in a colony disappear and leave behind a queen plenty of food and a few nurse bees to care for the remaining immature bees and the queen while such disappearances have occurred throughout the history of apiculture and were known by various names disappearing disease spring dwindle may disease autumn collapse and fall dwindle disease the syndrome was renamed colony collapse disorder in late 2006 in conjunction with a drastic rise in the number of disappearances of western honey bee apis mellifera colonies in north america european beekeepers observed similar phenomena in belgium france the netherlands greece italy portugal and spain switzerland and germany albeit to a lesser degree and the northern ireland assembly received reports of a decline greater than 50 colony collapse disorder causes significant economic losses because many agricultural crops although no staple foods worldwide are pollinated by western honey bees according to the agriculture and consumer protection department of the food and agriculture organization of the united nations the worth of global crops with honey bee s pollination was estimated to be close to 200 billion in 2005 shortages of bees in the us have increased the cost to farmers renting them for pollination services by up to 20 in the six years leading up to 2013 more than 10 million beehives were lost often to ccd nearly twice the normal rate of loss several possible causes for ccd have been proposed but no single proposal has gained widespread acceptance among the scientific community suggested causes include infections with varroa and acarapis mites malnutrition various pathogens genetic factors immunodeficiencies loss of habitat changing beekeeping practices or a combination of factors a large amount of speculation has surrounded a family of pesticides called neonicotinoids as having caused ccd
in computer graphics and 3 d rendering color bleeding is the phenomenon in which objects or surfaces are colored by reflection of colored light from nearby surfaces color bleeding the transfer of color between nearby objects or caused by the colored reflection of indirect light this is a visible effect that appears when a scene is rendered with radiosity or full global illumination or can otherwise be simulated by adding colored lights to a 3 d scene
color blindness also known as color vision deficiency is the decreased ability to see color or differences in color color blindness can make some educational activities difficult buying fruit picking clothing and reading traffic lights can also be more challenging problems however are generally minor and most people adapt people with total color blindness may also have decreased visual acuity and be uncomfortable in bright environments the most common cause of color blindness is a fault in the development of one or more of the three sets of color sensing cones in the eye males are more likely to be color blind than females as the genes responsible for the most common forms of color blindness are on the x chromosome as females have two x chromosomes a defect in one is typically compensated for by the other while males only have one x chromosome color blindness can also result from physical or chemical damage to the eye optic nerve or parts of the brain diagnosis is typically with the ishihara color test however a number of other testing methods also exist there is no cure for color blindness diagnosis may allow a person s teacher to change their method of teaching to accommodate the decreased ability to recognize color special lenses may help people with red green color blindness when under bright conditions there are also mobile apps that can help people identify colors red green color blindness is the most common form followed by blue yellow color blindness and total color blindness red green color blindness affects up to 8 of males and 0 5 of females of northern european descent the ability to see color also decreases in old age being color blind may make people ineligible for certain jobs in certain countries this may include pilot train driver and armed forces the effect of color blindness on artistic ability however is controversial the ability to draw appears to be unchanged and a number of famous artists are believed to have been color blind
color confinement often simply called confinement is the phenomenon that color charged particles such as quarks cannot be isolated singularly and therefore cannot be directly observed quarks by default clump together to form groups or hadrons the two types of hadrons are the mesons one quark one antiquark and the baryons three quarks the constituent quarks in a group cannot be separated from their parent hadron and this is why quarks currently cannot be studied or observed in any more direct way than at a hadron level
color mapping is a function that maps transforms the colors of one source image to the colors of another target image a color mapping may be referred to as the algorithm that results in the mapping function or the algorithm that transforms the image colors color mapping is also sometimes called color transfer or when grayscale images are involved brightness transfer function btf
in chemistry a color reaction or colour reaction is a chemical reaction that is used to transform colorless chemical compounds into colored derivatives which can be detected visually or with the aid of a colorimeter the concentration of a colorless solution cannot normally be determined with a colorimeter the addition of a color reagent leads to a color reaction and the absorbance of the colored product can then be measured with a colorimeter a change in absorbance in the ultraviolet range cannot be detected by eye but can be measured by a suitably equipped colorimeter a special colorimeter is required because standard colorimeters cannot operate below a wavelength of 400 nanometers it is also necessary to use fused quartz cuvettes because glass is opaque to ultraviolet
color superconductivity is a phenomenon predicted to occur in quark matter if the baryon density is sufficiently high well above nuclear density and the temperature is not too high well below 1012 kelvin color superconducting phases are to be contrasted with the normal phase of quark matter which is just a weakly interacting fermi liquid of quarks in theoretical terms a color superconducting phase is a state in which the quarks near the fermi surface become correlated in cooper pairs which condense in phenomenological terms a color superconducting phase breaks some of the symmetries of the underlying theory and has a very different spectrum of excitations and very different transport properties from the normal phase
color vision is the ability of an organism or machine to distinguish objects based on the wavelengths or frequencies of the light they reflect emit or transmit colors can be measured and quantified in various ways indeed a person s perception of colors is a subjective process whereby the brain responds to the stimuli that are produced when incoming light reacts with the several types of cone cells in the eye in essence different people see the same illuminated object or light source in different ways
in mathematics a complex function is a function with the complex numbers see the imaginary numbers and the complex plane as both its domain and codomain the complex color wheel method assigns a color to each point of the complex plane
the colorado state tartan is the scottish tartan pattern officially adopted by the u s state of colorado to represent the state in various functions and occasions
colorado tick fever ctf also called mountain tick fever american tick fever and american mountain tick fever is a viral infection coltivirus transmitted from the bite of an infected rocky mountain wood tick dermacentor andersoni it should not be confused with the bacterial tick borne infection rocky mountain spotted fever the type species of the genus coltivirus colorado tick fever virus ctfv infects haemopoietic cells particularly erythrocytes which explains how the virus is transmitted by ticks and also accounts for the incidence of transmission by blood transfusion
the colorectal adenoma is a benign glandular tumor of the colon and the rectum it is a precursor lesion of the colorectal adenocarcinoma colon cancer some morphological variants have been described tubular adenoma tubulovillous adenoma villous adenoma sessile serrated adenoma ssa
colorectal cancer crc also known as bowel cancer is the development of cancer from the colon or rectum parts of the large intestine it is due to the abnormal growth of cells that have the ability to invade or spread to other parts of the body signs and symptoms may include blood in the stool a change in bowel movements weight loss and feeling tired all the time most colorectal cancers are due to old age and lifestyle factors with only a small number of cases due to underlying genetic disorders some risk factors include diet obesity smoking and lack of physical activity dietary factors that increase the risk include red and processed meat as well as alcohol another risk factor is inflammatory bowel disease which includes crohn s disease and ulcerative colitis some of the inherited genetic disorders that can cause colorectal cancer include familial adenomatous polyposis and hereditary non polyposis colon cancer however these represent less than 5 of cases it typically starts as a benign tumor often in the form of a polyp which over time becomes cancerous bowel cancer may be diagnosed by obtaining a sample of the colon during a sigmoidoscopy or colonoscopy this is then followed by medical imaging to determine if the disease has spread screening is effective for preventing and decreasing deaths from colorectal cancer screening is recommended starting from the age of 50 to 75 during colonoscopy small polyps may be removed if found if a large polyp or tumor is found a biopsy may be performed to check if it is cancerous aspirin and other non steroidal anti inflammatory drugs decrease the risk their general use is not recommended for this purpose however due to side effects treatments used for colorectal cancer may include some combination of surgery radiation therapy chemotherapy and targeted therapy cancers that are confined within the wall of the colon may be curable with surgery while cancer that has spread widely are usually not curable with management focusing on improving quality of life and symptoms five year survival rates in the united states are around 65 this however depends on how advanced the cancer is whether or not all the cancer can be removed with surgery and the person s overall health globally colorectal cancer is the third most common type of cancer making up about 10 of all cases in 2012 there were 1 4 million new cases and 694 000 deaths from the disease it is more common in developed countries where more than 65 of cases are found it is less common in women than men
a colorectal polyp is a polyp fleshy growth occurring on the lining of the colon or rectum untreated colorectal polyps can develop into colorectal cancer colorectal polyps are often classified by their behaviour i e benign vs malignant and or etiology e g as a consequence of inflammatory bowel disease they may be benign e g hyperplastic polyp pre malignant e g tubular adenoma or malignant e g colorectal adenocarcinoma
colored fire is a common pyrotechnic effect used in stage productions fireworks and by fire performers the world over generally the color of a flame may be red orange blue yellow or white and is dominated by blackbody radiation from soot and steam when additional chemicals are added to the fuel burning their atomic emission spectra can affect the frequencies of visible light radiation emitted in other words the flame will appear a different color dependent upon the chemical additives flame coloring is also a good way to demonstrate how chemicals change when subjected to heat and how they also change the matter around them to color their flames pyrotechnicians will generally use metal salts specific combinations of fuels and co solvents are required in order to dissolve the necessary chemicals color enhancers usually chlorine donors are frequently added too the most common of which is polyvinyl chloride a practical use of colored fire is the flame test where metal cations are tested by placing the sample in a flame and analyzing the color produced
color – flavor locking cfl is a phenomenon that is expected to occur in ultra high density strange matter a form of quark matter the quarks form cooper pairs whose color properties are correlated with their flavor properties in a one to one correspondence between three color pairs and three flavor pairs according to the standard model of particle physics the color flavor locked phase is the highest density phase of three flavor matter
colour sided is a colour pattern of domesticated cattle it is sometimes called lineback it consists of a dark body colour with white finching along the spine white under the belly and often white also over the tail head and legs the ears nose and feet are generally dark the pattern may occur in many breeds but some breeds are consistently colour sided including english longhorn cattle irish moiled cattle randall cattle riggit galloway cattle and lineback cattle the dark colour may be any solid colour such as black red or brindle an extreme pale form of the colour sided pattern is where the darker colour is restricted to the ears nose and feet leaving most of the animal white this is found for example in white park british white and some irish moiled cattle
colour banding is a problem of inaccurate colour presentation in computer graphics in 24 bit colour modes 8 bits per channel is usually considered sufficient to render images in rec 709 or srgb however in some cases there is a risk of producing abrupt changes between shades of the same colour for instance displaying natural gradients like sunsets dawns or clear blue skies can show minor banding colour banding is more noticeable with fewer bits per pixel bpp at 16 – 256 colours 4 – 8 bpp where not every shade can be shown because there are insufficient bits to represent them possible solutions include the introduction of dithering and increasing the number of bits per colour channel
colpocephaly is a cephalic disorder involving the disproportionate enlargement of the occipital horns of the lateral ventricles and is usually diagnosed early after birth due to seizures it is a nonspecific finding and is associated with multiple neurological syndromes including agenesis of the corpus callosum chiari malformation lissencephaly and microcephaly although the exact cause of colpocephaly is not known yet it is commonly believed to occur as a result of neuronal migration disorders during early brain development intrauterine disturbances perinatal injuries and other central nervous system disorders individuals with colpocephaly have various degrees of motor disabilities visual defects spasticity and moderate to severe intellectual disability no specific treatment for colpocephaly exists but patients may undergo certain treatments to improve their motor function or intellectual disability
columnaris also referred to as cottonmouth is a symptom of disease in fish which results from an infection caused by the gram negative aerobic rod shaped bacterium flavobacterium columnare it was previously known as bacillus columnaris chondrococcus columnaris cytophaga columnaris and flexibacter columnaris the bacteria are ubiquitous in fresh water and cultured fish reared in ponds or raceways are the primary concern – with disease most prevalent in air temperatures above 12 – 14 ° c it is often mistaken for a fungal infection the disease is highly contagious and the outcome is often fatal it is not zoonotic
coma blisters are a cutaneous condition characterized by tense bullae at sites of maximal pressure
a comb is a fleshy growth or crest on the top of the head of gallinaceous birds such as turkeys pheasants and domestic chickens its alternative name cockscomb spelling variations abound is because combs are generally larger on males than on females a male gallinaceous bird is called a cock there can be several fleshy protuberances on the heads and throats of gallinaceous birds i e comb wattle ear lobes and nodules which collectively are called caruncles however in turkeys caruncle refers specifically to the fleshy nodules on the head and throat chicken combs are most commonly red but may be black or dark purple in breeds such as silkies or sebrights but in other species the color may vary from light grey to deep blue or red turkey combs can vary in color from bright red to blue the comb may be a reliable indicator of health or vigor and is used for mate assessment in some poultry species
combat readiness is a condition of the armed forces and their constituent units and formations warships aircraft weapon systems or other military technology and equipment to perform during combat military operations or functions consistent with the purpose for which they are organized or designed or the managing of resources and personnel training in preparation for combat most armed forces maintain varying levels of readiness by the troops to engage in combat due to economic considerations which vary from minutes to months in modern armed forces troops designated special forces are usually those kept at the highest state of readiness for combat and are often alerted only a few hours before being committed to combat where time is of the essence in military action being initiated the troops such as pilots of interceptor aircraft may be kept in constant state of combat readiness
combat stress reaction csr is a term used within the military to describe acute behavioral disorganization seen by medical personnel as a direct result of the trauma of war also known as combat fatigue or battle neurosis it has some overlap with the diagnosis of acute stress reaction used in civilian psychiatry it is historically linked to shell shock and can sometimes precurse post traumatic stress disorder combat stress reaction is an acute reaction that includes a range of behaviors resulting from the stress of battle that decrease the combatant s fighting efficiency the most common symptoms are fatigue slower reaction times indecision disconnection from one s surroundings and inability to prioritize combat stress reaction is generally short term and should not be confused with acute stress disorder post traumatic stress disorder or other long term disorders attributable to combat stress although any of these may commence as a combat stress reaction in world war i shell shock was considered a psychiatric illness resulting from injury to the nerves during combat the horrors of trench warfare meant that about 10 of the fighting soldiers were killed compared to 4 5 during world war ii and the total proportion of troops who became casualties killed or wounded was 56 whether a shell shock sufferer was considered wounded or sick depended on the circumstances when faced with the phenomenon of a minority of soldiers mentally breaking down there was an expectation that the root of this problem lay in character of the individual soldier not because of what they experienced on the front lines during the war these sorts of attitudes helped fuel the main argument that was accepted after the war and going forward that there was a social root to shell shock that consisted of soldiers finding the only way allowed by the military to show weakness and get out of the front claiming that their mental anguish constituted a legitimate medical diagnosis as a disease the large proportion of world war i veterans in the european population meant that the symptoms were common to the culture
the combes quinoline synthesis is a chemical reaction which was first reported by combes in 1888 it involves the condensation of unsubstituted anilines 1 with β diketones 2 to form substituted quinolines 4 after an acid catalyzed ring closure of an intermediate schiff base 3 further studies and reviews of the combes quinoline synthesis and its variations have been published by alyamkina et al bergstrom and franklin born and johnson and mathews the combes quinoline synthesis is often used to prepare the 2 4 substituted quinoline backbone and is unique in that it uses a β diketone substrate which is different from other quinoline preparations such as the conrad limpach synthesis and the doebner reaction the combes quinoline synthesis
a combination reaction also known as a synthesis reaction is a reaction where two or more elements or compounds reactants combine to form a single compound product such reactions may be represented by equations of the following form x y → xy combination reactions can involve different types of reactants there is no specific number of reactants in a combination reaction combination reactions are usually exothermic because when the bond forms between the reactants heat is released for example barium metal and fluorine gas will combine in a highly exothermic reaction to form the salt barium fluoride ba f 2 → baf 2 another example is magnesium oxide combining with carbon dioxide to produce magnesium carbonate mgo co 2 → mgco 3 another example is iron combining with sulphur to produce iron ii sulfide fe s → fes when a combination reaction occurs between a metal and a non metal the product is an ionic solid an example could be lithium reacting with sulphur to give lithium sulphide when magnesium burns in air the atoms of the metal combine with the gas oxygen to produce magnesium oxide this specific combination reaction produces the bright flame generated by flares
a combination tone also called resultant or subjective tone is a psychoacoustic phenomenon of an additional tone or tones that are artificially perceived when two real tones are sounded at the same time their discovery is credited to the violinist giuseppe tartini although he was not the first see sorge and so are also called tartini tones there are two types of combination tones sum tones whose frequencies are found by adding the frequencies of the real tones and difference tones whose frequencies are the difference between the frequencies of the real tones combination tones are heard when two pure tones i e tones produced by simple harmonic sound waves having no overtones differing in frequency by about 50 cycles per second or more sound together at sufficient intensity combination tones can also be produced electronically by combining two signals in a circuit that has nonlinear distortion such as an amplifier subject to clipping or a ring modulator
combined drug intoxication cdi also known as multiple drug intake mdi or lethal polydrug polypharmacy intoxication is an unnatural cause of human death cdi is often confused with drug overdose but it is a completely different phenomenon it is distinct in that it is due to the simultaneous use of multiple drugs whether the drugs are prescription over the counter recreational or some other combination alcohol can exacerbate the symptoms and may directly contribute to increased severity of symptoms the reasons for toxicity vary depending on the mixture of drugs usually most victims die after using two or more drugs in combination that suppress breathing and the low blood oxygen level causes brain death the cdi mdi phenomenon seems to be becoming more common in recent years in december 2007 according to dr john mendelson a pharmacologist at the california pacific medical center research institute deaths by combined drug intoxication were relatively rare one in several million though they appeared then to be on the rise in july 2008 the associated press and cnn reported on a medical study showing that over two decades from 1983 to 2004 such deaths have soared it has also become a prevalent risk for older patients
combined hyperlipidemia or aemia also known as multiple type hyperlipoproteinemia is a commonly occurring form of hypercholesterolemia elevated cholesterol levels characterised by increased ldl and triglyceride concentrations often accompanied by decreased hdl on lipoprotein electrophoresis a test now rarely performed it shows as a hyperlipoproteinemia type iib it is the most commonly inherited lipid disorder occurring in around one in 200 persons in fact almost one in five individuals who develop coronary heart disease before the age of 60 have this disorder the elevated triglyceride levels 5 mmol l are generally due to an increase in very low density lipoprotein vldl a class of lipoproteins prone to cause atherosclerosis
combined immunodeficiencies or combined immunity deficiency are immunodeficiency disorders that involve multiple components of the immune system including both humoral immunity and cell mediated immunity this category includes conditions such as bare lymphocyte syndrome as well as severe combined immunodeficiency icd 9 divides immune deficiencies into three categories humoral 279 0 cell mediated 279 1 and combined 279 2 however icd 10 does not include a category for cell mediated immune dysfunction antibody is d 80 and combined is d 81 thus grouping t cell mediated conditions with combined conditions
combined small cell lung carcinoma or c sclc and rarely rendered as small cell lung carcinoma is a form of multiphasic lung cancer that is diagnosed by a pathologist when a malignant tumor arising from transformed cells originating in lung tissue contains a component of small cell lung carcinoma sclc admixed with one or more components of non small cell lung carcinoma nsclc
combustion kəmˈbʌs tʃən or burning is a high temperature exothermic redox chemical reaction between a fuel and an oxidant usually atmospheric oxygen that produces oxidized often gaseous products in a mixture termed as smoke combustion in a fire produces a flame and the heat produced can make combustion self sustaining combustion is often a complicated sequence of elementary radical reactions solid fuels such as wood first undergo endothermic pyrolysis to produce gaseous fuels whose combustion then supplies the heat required to produce more of them combustion is often hot enough that light in the form of either glowing or a flame is produced a simple example can be seen in the combustion of hydrogen and oxygen into water vapor a reaction commonly used to fuel rocket engines this reaction releases 242 kj mol of heat and reduces the enthalpy accordingly at constant temperature and pressure 2 h 2 g o 2 g → 2 h 2 o g combustion of an organic fuel in air is always exothermic because the double bond in o 2 is much weaker than other double bonds or pairs of single bonds and therefore the formation of the stronger bonds in the combustion products co 2 and h 2 o results in the release of energy the bond energies in the fuel play only a minor role since they are similar to those in the combustion products e g the sum of the bond energies of ch 4 is nearly the same as that of co 2 the heat of combustion is approximately 418 kj per mole of o 2 used up in the combustion reaction and can be estimated from the elemental composition of the fuel uncatalyzed combustion in air requires fairly high temperatures complete combustion is stoichiometric with respect to the fuel where there is no remaining fuel and ideally no remaining oxidant thermodynamically the chemical equilibrium of combustion in air is overwhelmingly on the side of the products however complete combustion is almost impossible to achieve since the chemical equilibrium is not necessarily reached or may contain unburnt products such as carbon monoxide hydrogen and even carbon soot or ash thus the produced smoke is usually toxic and contains unburned or partially oxidized products any combustion at high temperatures in atmospheric air which is 78 percent nitrogen will also create small amounts of several nitrogen oxides commonly referred to as nox since the combustion of nitrogen is thermodynamically favored at high but not low temperatures since combustion is rarely clean flue gas cleaning or catalytic converters may be required by law fires occur naturally ignited by lightning strikes or by volcanic products combustion fire was the first controlled chemical reaction discovered by humans in the form of campfires and bonfires and continues to be the main method to produce energy for humanity usually the fuel is carbon hydrocarbons or more complicated mixtures such as wood that contains partially oxidized hydrocarbons the thermal energy produced from combustion of either fossil fuels such as coal or oil or from renewable fuels such as firewood is harvested for diverse uses such as cooking production of electricity or industrial or domestic heating combustion is also currently the only reaction used to power rockets combustion is also used to destroy incinerate waste both nonhazardous and hazardous oxidants for combustion have high oxidation potential and include atmospheric or pure oxygen chlorine fluorine chlorine trifluoride nitrous oxide and nitric acid for instance hydrogen burns in chlorine to form hydrogen chloride with the liberation of heat and light characteristic of combustion although usually not catalyzed combustion can be catalyzed by platinum or vanadium as in the contact process
a comedo is a clogged hair follicle pore in the skin keratin skin debris combines with oil to block the follicle a comedo can be open blackhead or closed by skin whitehead and occur with or without acne the word comedo comes from the latin comedere meaning to eat up and was historically used to describe parasitic worms in modern medical terminology it is used to suggest the worm like appearance of the expressed material the chronic inflammatory condition that usually includes both comedones and inflamed papules and pustules pimples is called acne infection causes inflammation and the development of pus whether or not a skin condition classifies as acne depends on the amount of comedones and infection comedones should not be confused with sebaceous filaments comedo type ductal carcinoma in situ dcis is not related to the skin conditions discussed here dcis is a non invasive form of breast cancer but comedo type dcis may be more aggressive and so may be more likely to become invasive
comedocarcinoma is one kind of breast cancer which is most commonly very early stage which demonstrates central necrosis it is a usually a type of ductal carcinoma in situ comedo carcinomas are usually non infiltrating and intraductal tumors however there have been accounts of comedocarcinoma which has then diversified into other cell types and developed into infiltrating invasive ductal carcinoma recurrence and survival rates differ for invasive breast cancer which has originated as comedocarcinoma compared with other types of cancer cells the duct will have characteristic necrotic tissue with calcification that feels cord like squeezing the duct will yield inspissated material that is cheese like and similar in consistency to toothpaste comedocarcinoma has also been described as a histopathological type of sebaceous carcinoma
comedown or crashing is the deterioration in mood that happens as a psychoactive drug is cleared from the blood and thus the cerebral circulation the improvement and deterioration of mood euphoria and dysphoria are represented in the cognitive schema as high and low elevations thus after the drug has elevated the mood a state known as a high there follows a period of coming back down such a comedown down low crash can happen to anyone as a transient symptom but in people who are dependent on the drug especially those addicted to it it is an early symptom of withdrawal and thus can be followed by others various drug classes most especially stimulants and opioids are subject to crashing a milder analogous mood cycle can happen even with blood sugar levels thus sugar highs and sugar lows which is especially relevant to people with diabetes mellitus and to parents and teachers dealing with children s behavior
in object oriented programming the command pattern is a behavioral design pattern in which an object is used to encapsulate all information needed to perform an action or trigger an event at a later time this information includes the method name the object that owns the method and values for the method parameters four terms always associated with the command pattern are command receiver invoker and client a command object knows about receiver and invokes a method of the receiver values for parameters of the receiver method are stored in the command the receiver then does the work an invoker object knows how to execute a command and optionally does bookkeeping about the command execution the invoker does not know anything about a concrete command it knows only about command interface both an invoker object and several command objects are held by a client object the client decides which commands to execute at which points to execute a command it passes the command object to the invoker object using command objects makes it easier to construct general components that need to delegate sequence or execute method calls at a time of their choosing without the need to know the class of the method or the method parameters using an invoker object allows bookkeeping about command executions to be conveniently performed as well as implementing different modes for commands which are managed by the invoker object without the need for the client to be aware of the existence of bookkeeping or modes
in the united states commercial finance is the function of offering loans to businesses commercial financing is generally offered by a bank or other lender most commercial banks offer commercial financing and the loans are either secured by business assets or alternatively can be unsecured where the lender relies of the cash flows of the business to repay the facility assets used to collatoralize commercial finance loans include real estate receivables from invoices equipment or supplies while qualifying for financing is generally easier for large well established companies some small businesses can qualify for commercial financing from the small business administration sba the sba may provide either financing or insure a lender who takes a risk on a smaller company to provide commercial finance businesses can also seek the assistance of commercial finance advisors in the structuring and sourcing of commercial finance these are known as independent financial advisers or commercial finance brokers
in karl marx s critique of political economy commodity fetishism is the perception of the social relationships involved in production not as relationships among people but as economic relationships among the money and commodities exchanged in market trade as such commodity fetishism transforms the subjective abstract aspects of economic value into objective real things that people believe have intrinsic value the theory of commodity fetishism is presented in the first chapter of capital critique of political economy 1867 at the conclusion of the analysis of the value form of commodities to explain that the social organization of labor is mediated through market exchange the buying and the selling of commodities goods and services hence in a capitalist society social relations between people — who makes what who works for whom the production time for a commodity et cetera — are perceived as economic relations among objects that is how valuable a given commodity is when compared to another commodity therefore the market exchange of commodities masks obscures the true economic character of the human relations of production between the worker and the capitalist karl marx explained the philosophic concepts underlying commodity fetishism thus as against this the commodity form and the value relation of the products of labour within which it appears have absolutely no connection with the physical nature of the commodity and the material relations arising out of this it is nothing but the definite social relation between men themselves which assumes here for them the fantastic form of a relation between things in order therefore to find an analogy we must take flight into the misty realm of religion there the products of the human brain appear as autonomous figures endowed with a life of their own which enter into relations both with each other and with the human race so it is in the world of commodities with the products of men s hands i call this the fetishism which attaches itself to the products of labour as soon as they are produced as commodities and is therefore inseparable from the production of commodities — karl marx capital volume i
a commodity pathway diversion is the ability of an object to move in and out of the commodity state over the course of its use life diversions can occur when an object is removed from its commodity pathway for its protection and preservation or when a previously removed object is commoditized through reentry into the commodity pathway after having gained value through its absence it is important to note that diversion is an integrated part of the commodity pathway
common bile duct stone also known as choledocholithiasis is the presence of gallstones in the common bile duct thus choledocho lithiasis this condition causes jaundice and liver cell damage and requires treatment by cholecystectomy and or ercp
common bunt also known as stinking smut and covered smut is a disease of both spring and winter wheats it is caused by two very closely related fungi tilletia tritici syn tilletia caries and t laevis syn t foetida
common cold also known simply as a cold is a viral infectious disease of the upper respiratory tract that primarily affects the nose the throat sinuses and voice box may also be affected signs and symptoms may begin less than two days following exposure they include coughing sore throat runny nose sneezing headache and fever people usually recover in seven to ten days some symptoms may last up to three weeks in those with other health problems pneumonia may occasionally develop well over 200 virus strains are implicated in the cause of the common cold the rhinoviruses are the most common they spread through the air during close contact with infected people and indirectly through contact with objects in the environment followed by transfer to the mouth or nose risk factors include going to daycare not sleeping well and psychological stress symptoms are mostly due to the body s immune response to the infection rather than to tissue destruction by the viruses themselves people with influenza often show similar symptoms as people with a cold though symptoms are usually more severe in the former there is no vaccine for the common cold the primary methods of prevention are hand washing not touching the eyes nose or mouth with unwashed hands and staying away from other sick people some evidence supports the use of face masks no cure for the common cold exists but the symptoms can be treated nonsteroidal anti inflammatory drugs nsaids such as ibuprofen may help with pain antibiotics should not be used evidence does not support a benefit from cough medicines the common cold is the most frequent infectious disease in humans the average adult gets two to four colds a year while the average child may get six to eight they occur more commonly during the winter these infections have been with humanity since ancient times
common equity is the amount that all common shareholders have invested in a company most importantly this includes the value of the common shares themselves however it also includes retained earnings and additional paid in capital
common root rot is a fungal disease of barley caused by cochliobolus sativus fusarium culmorum and f graminearum
common root rot is a disease of wheat caused by one or more fungi cochliobolus sativus fusarium culmorum and f graminearum are the most common pathogens responsible for common root rot
common scab is a plant disease of root and tuber crops caused by a small number of streptomyces species specifically s scabies s acidiscabies s turgidiscabies and others common scab mainly affects potato solanum tuberosum but can also cause disease on radish raphanus sativus parsnip pastinaca sativa beet beta vulgaris and carrot daucus carota this plant disease is found wherever these vegetables are grown common scab symptoms are variable and can range from surface russeting to deep pits in root and tuber vegetables this disease does not usually affect yields but it can greatly reduce quality of the harvested vegetables and make them unsuitable for sale root and tuber vegetables are susceptible to infection by streptomyces species as soon as the root or tuber forms but because this disease only affects root and tubers the symptoms are not usually noted until harvest dry soils increase disease incidence and severity therefore proper irrigation can aid in control of this disease common scab is suppressed if the soil ph is lower than 5 2 although scab lesions may still form in low ph soils due to physiological stresses or s acidiscabies
common seborrheic keratosis also known as basal cell papilloma and solid seborrheic keratosis is a common benign cutaneous condition characterized by a skin lesion with a dull or lackluster surface
common sense is a basic ability to perceive understand and judge things that is shared by common to nearly all people and can reasonably be expected of nearly all people without need for debate the everyday understanding of common sense derives from philosophical discussion involving several european languages related terms in other languages include latin sensus communis greek κοινὴ αἴσθησις koinē aísthēsis and french bon sens but these are not straightforward translations in all contexts similarly in english there are different shades of meaning implying more or less education and wisdom good sense is sometimes seen as equivalent to common sense and sometimes not common sense has at least two specifically philosophical meanings one is a capability of the animal soul greek psukhē proposed by aristotle which enables different individual senses to collectively perceive the characteristics of physical things such as movement and size which all physical things have in different combinations allowing people and other animals to distinguish and identify physical things this common sense is distinct from basic sensory perception and from human rational thinking but cooperates with both the second special use of the term is roman influenced and is used for the natural human sensitivity for other humans and the community just like the everyday meaning both of these refer to a type of basic awareness and ability to judge that most people are expected to share naturally even if they can not explain why all these meanings of common sense including the everyday one are inter connected in a complex history and have evolved during important political and philosophical debates in modern western civilisation notably concerning science politics and economics the interplay between the meanings has come to be particularly notable in english as opposed to other western european languages and the english term has become international in modern times the term common sense has frequently been used for rhetorical effect sometimes pejorative and sometimes appealed to positively as an authority it can be negatively equated to vulgar prejudice and superstition or on the contrary it is often positively contrasted to them as a standard for good taste and as the source of the most basic axioms needed for science and logic this began with descartes criticism of it and what came to be known as the dispute between rationalism and empiricism in the opening line of one of his most famous books discourse on method descartes established the most common modern meaning and its controversies when he stated that everyone has a similar and sufficient amount of common sense bon sens but it is rarely used well therefore a skeptical logical method described by descartes needs to be followed and common sense should not be overly relied upon in the ensuing 18 th century enlightenment common sense came to be seen more positively as the basis for modern thinking it was contrasted to metaphysics which was like cartesianism associated with the ancien régime thomas paine s polemical pamphlet common sense 1776 has been described as the most influential political pamphlet of the 18 th century affecting both the american and french revolutions today the concept of common sense and how it should best be used remains linked to many of the most perennial topics in epistemology and ethics with special focus often directed at the philosophy of the modern social sciences
common variable immunodeficiency cvid is an immune disorder characterized by recurrent infections and low antibody levels specifically in immunoglobulin ig types igg igm and iga generally symptoms include high susceptibility to foreign invaders chronic lung disease and inflammation and infection of the gastrointestinal tract however symptoms vary greatly between people cvid is a lifelong disease the origins of cvid is poorly understood current research points to deletions in particular genetic markers encoding cell surface proteins and cytokine receptors such as cd 19 cd 20 cd 21 and cd 80 as a likely cause a deletion is a mutation in which part of the chromosome is lost during dna replication additionally the disease is defined by t cell defects namely reduced proliferative capacity the disease is hard to diagnose taking on average 6 – 7 years after onset cvid is a primary immunodeficiency treatment options are limited and usually include lifelong immunoglobulin replacement therapy this therapy is thought to help reduce bacterial infections this treatment alone is not wholly effective and many people still experience other symptoms like lung disease and noninfectious inflammatory symptoms cvid was first diagnosed over 60 years ago and since has emerged as the predominant class of primary antibody deficiencies cvid is formally diagnosed by levels of igg and iga more than two standard deviations from the norm and no other cause for hypogammaglobulinemia an abnormally low level of immunoglobulins in the blood it is thought to affect between 1 in 25 000 to 1 in 50 000 people worldwide
commotio cordis latin agitation of the heart is an often lethal disruption of heart rhythm that occurs as a result of a blow to the area directly over the heart the precordial region at a critical time during the cycle of a heart beat causing cardiac arrest it is a form of ventricular fibrillation v fib not mechanical damage to the heart muscle or surrounding organs and not the result of heart disease the fatality rate is about 65 it can sometimes but not always be reversed by defibrillation commotio cordis occurs mostly in boys and young men average age 15 usually during sports most often baseball often despite a chest protector it is most often caused by a projectile but can also be caused by the blow of an elbow or other body part being less developed the thorax of an adolescent is likely more prone to this injury given the circumstances the phenomenon was confirmed experimentally in the 1930 s with research in anaesthetized rabbits cats and dogs
communal reinforcement is a social phenomenon in which a concept or idea is repeatedly asserted in a community regardless of whether sufficient empirical evidence has been presented to support it over time the concept or idea is reinforced to become a strong belief in many people s minds and may be regarded by the members of the community as fact often the concept or idea may be further reinforced by publications in the mass media books or other means of communication the phrase millions of people can t all be wrong is indicative of the common tendency to accept a communally reinforced idea without question which often aids in the widespread acceptance of factoids a very similar term to this term is community reinforcement which is a behavioral method to stop drug addiction
a communication disorder is any disorder that affects an individual s ability to comprehend detect or apply language and speech to engage in discourse effectively with others the delays and disorders can range from simple sound substitution to the inability to understand or use one s native language
in telecommunication communications survivability is the ability of communications systems to continue to operate effectively under adverse conditions though portions of the system may be damaged or destroyed various methods may be used to maintain communications services such as using alternate routing different transmission media or methods redundant equipment and sites and equipment that are radiation hardened
community based management cbm is a bottom up approach of organization which can be facilitated by an upper government or ngo structure but it aims for local stakeholder participation in the planning research development management and policy making for a community as a whole the decentralization of managing tactics enables local people to deal with the unique social political and ecological problems their community might face and find solutions ideal to their situation overwhelming national or local economic political and social pressures can affect the efficiency of cbm as well as its long term application cbm varies across spatial and temporal scales to reflect the ever changing distinctive physical and or human environment it is acting within while the specifics of each practice might differ existing research maintains that community based management when implemented properly is incredibly beneficial not only for the health of the environment but also for the well being of the stakeholders
community resilience is the sustained ability of a community to utilize available resources e g energy communication food etc to respond to withstand and recover from adverse situations e g economic collapse to global catastrophic risks this allows for the evolution and growth of a community after disaster strikes communities that are resilient are able to minimize any disaster making the return to normal life as effortless as possible by implementing a community resilience plan a community can come together and overcome any disaster while rebuilding physically and economically
the comondú complex is an archaeological pattern dating from the late prehistoric period in northern baja california sur and southern baja california it is associated with the historic cochimí people of the peninsula the complex was defined on the basis of investigations at rock shelters near the town of san jose de comondú by archaeologist william c massey beginning in the late 1940 s it has been recognized at sites extending from the sierra de la giganta west of loreto in the south to bahía de los ángeles in the north a key characteristic of the comondú complex is the presence of small comondú triangular and comondú serrated projectile points these points reflect the introduction of the bow and arrow into the peninsula perhaps around 500 1000 ce largely supplanting the earlier atlatl and dart other traits include grinding basins and slicks manos tubular stone pipes coiled basketry and square knot netting the region s great mural rock art may also be associated with the comondú complex
in medicine comorbidity is the presence of one or more additional diseases or disorders co occurring with that is concomitant or concurrent with a primary disease or disorder in the countable sense of the term a comorbidity plural comorbidities is each additional disorder or disease the additional disorder may be a behavioral or mental disorder the term can indicate either a condition existing simultaneously but independently with another condition or a related medical condition the latter sense of the term causes some overlap with the concept of complications for example in longstanding diabetes mellitus the extent to which coronary artery disease is an independent comorbidity versus a diabetic complication is not easy to measure because both diseases are quite multivariate and there are likely aspects of both simultaneity and consequence the same is true of intercurrent diseases in pregnancy in other examples the true independence or relation is not ascertainable because syndromes and associations are often identified long before pathogenetic commonalities are confirmed and in some examples before they are even hypothesized in psychiatric diagnoses it has been argued in part that this use of imprecise language may lead to correspondingly imprecise thinking and this usage of the term comorbidity should probably be avoided however in many medical examples such as comorbid diabetes mellitus and coronary artery disease it makes little difference which word is used as long as the medical complexity is duly recognized and addressed
comparative criminal justice is a subfield of the study of criminal justice that compares justice systems worldwide such study can take a descriptive historical or political approach it studies the similarities and differences in structure goals punishment and emphasis on rights as well as the history and political stature of different systems it is common to broadly categorize the functions of a criminal justice system into policing adjudication i e courts and corrections although other categorization schemes exist comparativists study the four different types of societies their methods of enforcement and their different types of punishment such as capital punishment and imprisonment within these societies they study different types of legal tradition and analyze the issues they solve and create they use their information in order to learn effective ways of enforcing laws and to identify and solve problems that may arise within a system due to its methods
comparative economic systems is the subfield of economics dealing with the comparative study of different systems of economic organization such as capitalism socialism feudalism and the mixed economy it is widely held to be founded by the economist calvin bryce hoover comparative economics therefore consisted mainly of comparative economic systems analysis before 1989 but switched substantially its efforts to comparison of the economic effects of the transition experience from socialism to capitalism
compartment syndrome is increased pressure within one of the body s compartments which contains muscles and nerves compartment syndrome most commonly occurs in compartments in the leg or arm there are two main types of compartment syndrome acute and chronic acute compartment syndrome occurs after a traumatic injury such as a car crash the trauma causes a severe high pressure in the compartment which results in insufficient blood supply to muscles and nerves acute compartment syndrome is a medical emergency that requires surgery to correct if untreated the lack of blood supply leads to permanent muscle and nerve damage and can result in the loss of function of the limb chronic exertional compartment syndrome is an exercise induced condition in which the pressure in the muscles increases to extreme levels during exercise the pressure creates a decrease in blood flow to the affected area which leads to a deprivation of oxygen to the muscles the symptoms are a sensation of extreme tightness in the affected muscles followed by a burning sensation if exercise is continued chronic exertional compartment syndrome usually occurs in athletes who participate in repetitive impact sports such as running
the establishment and spread of infectious diseases is a complex phenomenon with many interacting factors e g the environment in which the pathogen and hosts are situated the population s it is exposed to and the intra and inter dynamics of the population it is exposed to the role of mathematical epidemiology is to model the establishment and spread of pathogens a predominant method of doing so is to use the notion of abstracting the population into compartments under certain assumptions which represent their health status with respect to the pathogen in the system one of the cornerstone works to achieve success in this method was done by kermack and mckendrick in the early 1900 s these models are known as compartmental models in epidemiology and serve as a base mathematical framework for understanding the complex dynamics of these systems which hope to model the main characteristics of the system these compartments in the simplest case can stratify the population into two health states susceptible to the infection of the pathogen often denoted by s and infected by the pathogen given the symbol i the way that these compartments interact is often based upon phenomenological assumptions and the model is built up from there these models are usually investigated through ordinary differential equations which are deterministic but can also be viewed in more realistic stochastic framework for example the gillespie model to push these basic models to further realism other compartments are often included most notably the recovered removed immune compartment denoted r once one is able to model an infectious pathogen with compartmental models one can predict the various properties of the pathogen spread for example the prevalence total number of infected from the epidemic and the duration of the epidemic also one can understand how different situations may affect the outcome of the epidemic e g what is the best technique for issuing a limited number of vaccines in a given population
compassion fatigue also known as secondary traumatic stress sts is a condition characterized by a gradual lessening of compassion over time it is common among individuals that work directly with trauma victims such as therapists paid and unpaid nurses teachers psychologists police officers first responders animal welfare workers health unit coordinators and anyone who helps out others especially family members relatives and other informal caregivers of patients suffering from a chronic illness it was first diagnosed in nurses in the 1950 s sufferers can exhibit several symptoms including hopelessness a decrease in experiences of pleasure constant stress and anxiety sleeplessness or nightmares and a pervasive negative attitude this can have detrimental effects on individuals both professionally and personally including a decrease in productivity the inability to focus and the development of new feelings of incompetency and self doubt journalism analysts argue that the media has caused widespread compassion fatigue in society by saturating newspapers and news shows with often decontextualized images and stories of tragedy and suffering this has caused the public to become cynical or become resistant to helping people who are suffering
the light compensation point is the amount of light intensity on the light curve where the rate of photosynthesis exactly matches the rate of respiration at this point the uptake of co 2 through photosynthetic pathways is exactly matched to the respiratory release of carbon dioxide and the uptake of o 2 by respiration is exactly matched to the photosynthetic release of oxygen in assimilation terms at compensation point the net carbon dioxide assimilation is zero leaves release co 2 by photorespiration and day respiration but co 2 is also converted into carbohydrate by photosynthesis assimilation is therefore the difference in the rate of these processes at a normal partial pressure of co 2 338 mbar in 1980 there is an irradiation at which the net assimilation of co 2 is zero for instance in the early morning and late evenings the compensation point may be reached as photosynthetic activity decreases and respiration increases therefore the partial pressure of co 2 at the compensation point also known as gamma is a function of irradiation the irradiation dependence of the compensation point is explained by the rubp ribulose 1 5 bisphosphate concentration when the acceptor rubp is in saturated concentration gamma is independent of irradiation however at low irradiation only a small fraction of the sites on rubp carboxylase oxygenase enzyme rubisco have the electron acceptor rubp this decreases the photosynthetic activity and therefore affects gamma the intracellular concentration of co 2 affects the rates of photosynthesis and photo respiration at higher carbon dioxide concentrations the photosynthesis rate is higher while at low co 2 concentrations photo respiration is higher
compensatory growth is a type of regenerative growth that can take place in a number of human organs after the organs are either damaged removed or cease to function additionally increased functional demand can also stimulate this growth in tissues and organs the growth can be a result of increased cell size compensatory hypertrophy or an increase in cell division compensatory hyperplasia or both for instance if one kidney is surgically removed the cells of other kidney divide at an increased rate eventually the remaining kidney can grow until its mass approaches the combined mass of two kidneys along with the kidneys compensatory growth has also been characterized in a number of other tissues and organs including the adrenal glands the heart muscles the liver the lungs the pancreas beta cells and acinar cells the mammary gland the spleen where bone marrow and lymphatic tissue undergo compensatory hypertrophy and assumes the spleen function during spleen injury the testicles the thyroid gland a large number of growth factors and hormones are involved with compensatory growth but the exact mechanism is not fully understood and probably varies between different organs nevertheless angiogenic growth factors which control the growth of blood vessels are particularly important because blood flow significantly determines the maximum growth of an organ compensatory growth may also refer to the accelerated growth following a period of slowed growth particularly as a result of nutrient deprivation
compensatory growth known as catch up growth and compensatory gain is an accelerated growth of an organism following a period of slowed development particularly as a result of nutrient deprivation the growth may be with respect to weight or length or height in humans for example oftentimes the body weights of animals who experience nutritional restriction will over time become similar to those of animals who did not experience such stress it is possible for high compensatory growth rates to result in overcompensation where the organism exceeds normal weight and often has excessive fat deposition an organism can recover to normal weight without additional time sometimes when the nutrient restriction is severe the growth period is extended to reach the normal weight if the nutrient restriction is severe enough the organism may have permanent stunted growth where it does not ever reach normal weight usually in animals complete recovery from carbohydrate and protein restriction occurs compensatory growth has been observed in a number of organisms including humans other species of mammals birds reptiles fish plants especially grasses and young tree seedlings and saplings fungi microbes and damselflies
competence is the ability of an individual to do a job properly a competency is a set of defined behaviors that provide a structured guide enabling the identification evaluation and development of the behaviors in individual employees the term competence first appeared in an article authored by r w white in 1959 as a concept for performance motivation in 1970 craig c lundberg defined the concept in planning the executive development program the term gained traction when in 1973 david mcclelland wrote a seminal paper entitled testing for competence rather than for intelligence it has since been popularized by richard boyatzis and many others such as t f gilbert 1978 who used the concept in relationship to performance improvement its use varies widely which leads to considerable misunderstanding competence has appeared in varied countries and varied scientific contexts with different meanings klarsfeld 2000 some scholars see competence as a combination of practical and theoretical knowledge cognitive skills behavior and values used to improve performance or as the state or quality of being adequately or well qualified having the ability to perform a specific role for instance management competency might include systems thinking and emotional intelligence and skills in influence and negotiation competency is also used as a more general description of the requirements of human beings in organizations and communities competency is sometimes thought of as being shown in action in a situation and context that might be different the next time a person has to act in emergencies competent people may react to a situation following behaviors they have previously found to succeed to be competent a person would need to be able to interpret the situation in the context and to have a repertoire of possible actions to take and have trained in the possible actions in the repertoire if this is relevant regardless of training competency would grow through experience and the extent of an individual to learn and adapt competency has different meanings and remains one of the most diffuse terms in the management development sector and the organizational and occupational literature competencies are also what people need to be successful in their jobs job competencies are not the same as job task competencies include all the related knowledge skills abilities and attributes that form a person ’ s job this set of context specific qualities is correlated with superior job performance and can be used as a standard against which to measure job performance as well as to develop recruit and hire employees competencies and competency models may be applicable to all employees in an organization or they may be position specific identifying employee competencies can contribute to improved organizational performance they are most effective if they meet several critical standards including linkage to and leverage within an organization ’ s human resource system core competencies differentiate an organization from its competition and create a company ’ s competitive advantage in the marketplace an organizational core competency is its strategic strength competencies provide organizations with a way to define in behavioral terms what it is that people need to do to produce the results that the organization desires in a way that is in keep with its culture by having competencies defined in the organization it allows employees to know what they need to be productive when properly defined competencies allows organizations to evaluate the extent to which behaviors employees are demonstrating and where they may be lacking for competencies where employees are lacking they can learn this will allow organizations to know potentially what resources they may need to help the employee develop and learn those competencies competencies can distinguish and differentiate your organization from your competitors while two organizations may be alike in financial results the way in which the results were achieve could be different based on the competencies that fit their particular strategy and organizational culture lastly competencies can provide a structured model that can be used to integrate management practices throughout the organization competencies that align their recruiting performance management training and development and reward practices to reinforce key behaviors that the organization values
the balance of competing goods is a philosophical problem involving the acknowledgement of multiple social values that may at times conflict with one another the 20 th century philosopher martha nussbaum invokes aristotle in her discussions of the problem writing that t he aristotelian agent scrutinizes each valuable alternative seeking out its distinct nature she is determined to acknowledge the precise sort of value or goodness present in each of competing alternatives seeing each value so to speak as a separate jewel in the crown valuable in its own right which does not cease to be separately valuable just because the contingencies of the situation sever it from other goods and it loses out in an overall rational choice and that aristotle saw that the values that are constitutive of a good human life are plural and incommensurable nussbaum has argued that immanuel kant and thomas aquinas were mistaken when they dismissed conflicts of obligation as illogical michael jinkins citing isaiah berlin sees both plato and aristotle as endorsing the concept of a singular overwhelming social good and machiavelli s works as seminal discussions of competing social goods the issue has arisen in the medical professions since patients may not necessarily rank their potential cures above their other values
compile time function execution or compile time function evaluation or general constant expressions is the ability of a compiler that would normally compile a function to machine code and execute it at run time to execute the function at compile time this is possible if the arguments to the function are known at compile time and the function does not make any reference to or attempt to modify any global state is a pure function if the value of only some of the arguments are known the compiler may still be able to perform some level of compile time function execution partial evaluation possibly producing more optimized code than if no arguments were known
complement dependent cytotoxicity cdc is a function of the complement system it is the processes in the immune system that kill pathogens by damaging their membranes without the involvement of antibodies or cells of the immune system there are three main processes all three insert one or more membrane attack complexes mac into the pathogen which cause lethal colloid osmotic swelling ie cdc it is one of the mechanisms by which antibodies or antibody fragments have an antitumor effect
in computational complexity theory the complement of a decision problem is the decision problem resulting from reversing the yes and no answers equivalently if we define decision problems as sets of finite strings then the complement of this set over some fixed domain is its complement problem for example one important problem is whether a number is a prime number its complement is to determine whether a number is a composite number a number which is not prime here the domain of the complement is the set of all integers exceeding one there is a turing reduction from every problem to its complement problem the complement operation is an involution meaning it undoes itself or the complement of the complement is the original problem one can generalize this to the complement of a complexity class called the complement class which is the set of complements of every problem in the class if a class is called c its complement is conventionally labelled co c notice that this is not the complement of the complexity class itself as a set of problems which would contain a great deal more problems a class is said to be closed under complement if the complement of any problem in the class is still in the class because there are turing reductions from every problem to its complement any class which is closed under turing reductions is closed under complement any class which is closed under complement is equal to its complement class however under many one reductions many important classes especially np are believed to be distinct from their complement classes although this has not been proven the closure of any complexity class under turing reductions is a superset of that class which is closed under complement the closure under complement is the smallest such class if a class is intersected with its complement we obtain a possibly empty subset which is closed under complement every deterministic complexity class dspace f n dtime f n for all f n is closed under complement because one can simply add a last step to the algorithm which reverses the answer this doesn t work for nondeterministic complexity classes because if there exist both computation paths which accept and paths which reject and all the paths reverse their answer there will still be paths which accept and paths which reject — consequently the machine accepts in both cases some of the most surprising complexity results shown to date showed that the complexity classes nl and sl are in fact closed under complement whereas before it was widely believed they were not see immerman – szelepcsényi theorem the latter has become less surprising now that we know sl equals l which is a deterministic class every class which is low for itself is closed under complement
complement 2 deficiency is a type of complement deficiency caused by any one of several different alterations in the structure of complement component 2 it has been associated with an increase in infections it can present similarly to systemic lupus erythematosus sle
complement 3 deficiency is a genetic condition affecting complement component 3 it can cause systemic lupus erythematosus like symptoms it can lead to an increase in pyogenic infections from encapsulated bacteria
complement 4 deficiency is a genetic condition affecting complement component 4 it can present with lupus like symptoms
complement deficiency is an immunodeficiency of absent or suboptimal functioning of one of the complement system proteins because there are redundancies in the immune system many complement disorders are never diagnosed some studies estimated that less than 10 are identified hypocomplementemia may be used more generally to refer to decreased complement levels while secondary complement disorder is to low complement levels that are not directly due to a genetic cause but secondary to another medical condition
complete androgen insensitivity syndrome cais is a condition that results in the complete inability of the cell to respond to androgens the unresponsiveness of the cell to the presence of androgenic hormones prevents the masculinization of male genitalia in the developing fetus as well as the development of male secondary sexual characteristics at puberty but does not significantly impair female genital or sexual development as such the insensitivity to androgens is only clinically significant when it occurs in genetic males i e individuals with a y chromosome or more specifically an sry gene all affected individuals are phenotypically female they develop a normal female habitus despite the presence of a y chromosome cais is one of the three categories of androgen insensitivity syndrome ais since ais is differentiated according to the degree of genital masculinization complete androgen insensitivity syndrome cais when the external genitalia is that of a normal female mild androgen insensitivity syndrome mais when the external genitalia is that of a normal male and partial androgen insensitivity syndrome pais when the external genitalia is partially but not fully masculinized androgen insensitivity syndrome is the largest single entity that leads to 46 xy undermasculinization
in mathematics a complex valued function sometimes referred to as complex function is a function whose values are complex numbers in other words it is a function that assigns a complex number to each member of its domain this domain does not necessarily have any structure related to complex numbers most important uses of such functions and are explicated below a vector space and a commutative algebra of functions over complex numbers can be defined in the same way as for real valued functions also any complex valued function f on an arbitrary set x can be considered as an ordered pair of two real valued functions ref imf or alternatively as a real valued function φ on x × 0 1 the disjoint union of two copies of x such that for any x re f x f x 0 imf x f x 1 some properties of complex valued functions such as measurability and continuity are nothing more than corresponding properties of real valued functions
a complex is a core pattern of emotions memories perceptions and wishes in the personal unconscious organized around a common theme such as power or status primarily a psychoanalytic term it is found extensively in the works of carl jung and sigmund freud an example of a complex would be as follows if you had a leg amputated when you were a child this would influence your life in profound ways even if you overcame the physical handicap you may have many thoughts emotions memories feelings of inferiority triumphs bitterness and determinations centering on that one aspect of your life if these thoughts were troubling and pervasive jung might say you had a complex about the leg complex existence is widely agreed upon in the area of depth psychology a branch of psychology that insists the most significant parts of your personality are derived from your unconscious it is a way of mapping the psyche and are crucial theoretical items in therapy complexes are believed by carl jung and sigmund freud to influence an individual s attitude and behavior
a mixed tumor is a tumor derived from one cell type that has divergent differentiation examples include pleomorphic adenoma and mixed müllerian tumor
complex contagion is the phenomenon in social networks in which multiple sources of exposure to an innovation are required before an individual adopts the change of behavior it differs from simple contagion in that unlike a disease it may not be possible for the innovation to spread after only one incident of contact with an infected neighbor the spread of complex contagion across a network of people may depend on many social and economic factors for instance how many of one s friends adopt the new idea as well as how many of them cannot influence the individual as well as their own disposition in embracing change
complex partial status epilepticus cpse is one of the non convulsive forms of status epilepticus a rare form of epilepsy defined by its recurrent nature cpse is characterized by seizures involving long lasting stupor staring and unresponsiveness sometimes this is accompanied by motor automatisms such as eye twitching
complex regional pain syndrome crps also known as reflex sympathetic dystrophy rsd is a long term condition that often worsens with time it is characterized by severe pain and sensitivity swelling and changes in the skin it may initially affect one limb and then spread throughout the body 35 of people report symptoms throughout their whole body the cause of crps is unknown though crps is associated with dysregulation of the central nervous system and autonomic nervous system resulting in multiple functional loss impairment and disability precipitating factors include injury and surgery although there are cases where no injury had occurred at the original site crps is not caused by psychological factors yet the constant pain and reduced quality of life has been known to cause psychological problems such as increased depression and anxiety although research does not reveal support for specific personality or psychopathology predictors of the condition crps is associated with psychosocial effects including impaired social and occupational function it is classified as an amplified musculoskeletal pain syndrome treatment is complicated involving medications physical and occupational therapy psychological treatments and neuromodulation and is often unsatisfactory especially if delayed
complex vertebral malformation or cvm is a lethal hereditary syndrome found in holstein cattle cvm is responsible for malformed calves that are either spontaneously aborted or die shortly after birth it is caused by a missense mutation in the slc 35 a 3 gene since the mutant form of the gene is recessive only individuals carrying two copies of the faulty gene homozygous individuals are affected heterozygous individuals those who carry one copy of the faulty gene and one copy of the normal gene have no symptoms but may still pass the disease on to their offspring
in computer science the complexity function of a string a finite or infinite sequence of letters from some alphabet is the function that counts the number of distinct factors substrings of consecutive symbols from that string more generally the complexity function of a language a set of finite words over an alphabet counts the number of distinct words of given length
compliance is the ability of a hollow organ vessel to distend and increase volume with increasing transmural pressure or the tendency of a hollow organ to resist recoil toward its original dimensions on application of a distending or compressing force it is the reciprocal of elastance hence elastance is a measure of the tendency of a hollow organ to recoil toward its original dimensions upon removal of a distending or compressing force
the compliance problem is a problem in contractarian ethics it states that it is in the individuals best interest to agree to contracts but not to comply to them thomas hobbes first outlined the compliance problem in the leviathan with the character called the foole his suggested solution was political coercion and oppression david gauthier is the current leading philosopher on the compliance problem his suggested solution includes the theory of minimax relative concession
in psychiatry complicated grief disorder cgd is a proposed disorder for those who are significantly and functionally impaired by prolonged grief symptoms for at least one month after six months of bereavement it is distinguished from non impairing grief and other disorders such as major depressive disorder and posttraumatic stress disorder this disorder has been reviewed by the dsm 5 work groups who have decided that it be called persistent complex bereavement disorder and placed it in the chapter on conditions for further study in the new dsm 5
the complications of diabetes mellitus are far less common and less severe in people who have well controlled blood sugar levels conversely some genes appear to provide protection against diabetic complications as evidenced by the absence of complications in a subset of long term diabetes survivors wider health problems accelerate the deleterious effects of diabetes these include smoking elevated cholesterol levels obesity high blood pressure and lack of regular exercise
complications of pregnancy are health problems that are caused by pregnancy there is no clear distinction between complications of pregnancy and symptoms and discomforts of pregnancy however the latter do not significantly interfere with activities of daily living or pose any significant threat to the health of the mother or baby still in some cases the same basic feature can manifest as either a discomfort or a complication depending on the severity for example mild nausea may merely be a discomfort morning sickness but if severe and with vomiting causing water electrolyte imbalance it can be classified as a pregnancy complication hyperemesis gravidarum in the immediate postpartum period 87 to 94 of women report at least one health problem long term health problems persisting after 6 months postpartum are reported by 31 of women severe complications of pregnancy are present in 1 6 of mothers in the us and in 1 5 of mothers in canada the relationship between age and complications of pregnancy are now being researched with greater impetus in 2013 complications of pregnancy resulted globally in 293 000 deaths down from 377 000 deaths in 1990 the most common causes include maternal bleeding complications of abortion high blood pressure of pregnancy maternal sepsis and obstructed labor
a component cause of a disease is an event required for the disease to develop given a disease or medical condition there is a causality chain of events from the first event to the appearance of the clinical disease a cause of a disease event is an event that preceded the disease event in a disease causal chain without this antecedent event the disease event either would not have occurred at all or would not have occurred until some later time however no specific event is sufficient by itself to produce disease hence such an event is a component of a sufficient cause see also sufficient cause of the disease rothman and greenland
composite entity is a java ee software design pattern and it is used to model represent and manage a set of interrelated persistent objects rather that representing them as individual fine grained entity beans and also a composite entity bean represents a graph of objects
composite odontoma is a rare defect in humans in which a benign tumor forms in the mouth generally as a result of the abnormal growth of a single tooth causing additional teeth to form within the tumor most cases have been found in the upper jaw of patients unchecked growth of the tumor can make swallowing and eating difficult and can also lead to grotesque facial swelling in most cases surgery is required to remove the extra teeth and tumorous tissue prior to 2014 the maximum recorded number of teeth removed in such an operation was 37 however in july 2014 ashiq gavai a 17 year old boy in india suffered from an extreme case of composite odontoma in his lower jaw which required the removal of more than 232 teeth altogether the surgery was performed by dr sunanda dhiware at sir j j hospital in mumbai india
in software engineering the composite pattern is a partitioning design pattern the composite pattern describes that a group of objects is to be treated in the same way as a single instance of an object the intent of a composite is to compose objects into tree structures to represent part whole hierarchies implementing the composite pattern lets clients treat individual objects and compositions uniformly
compound heterozygosity in medical genetics is the condition of having two heterogeneous recessive alleles at a particular locus that can cause genetic disease in a heterozygous state that is an organism is a compound heterozygote when it has two recessive alleles for the same gene but with those two alleles being different from each other for example both alleles might be mutated but at different locations compound heterozygosity reflects the diversity of the mutation base for many autosomal recessive genetic disorders mutations in most disease causing genes have arisen many times this means that many cases of disease arise in individuals who have two unrelated alleles who technically are heterozygotes but both the alleles are defective these disorders are often best known in some classic form such as the homozygous recessive case of a particular mutation that is widespread in some population in its compound heterozygous forms the disease may have lower penetrance because the mutations involved are often less deleterious in combination than for a homozygous individual with the classic symptoms of the disease as a result compound heterozygotes often become ill later in life with less severe symptoms although compound heterozygosity as a cause of genetic disease had been suspected much earlier widespread confirmation of the phenomenon was not feasible until the 1980 s when polymerase chain reaction techniques for amplification of dna made it cost effective to sequence genes and identify polymorphic alleles
a compound nevus is a type of mole formed by groups of nevus cells found in the epidermis and dermis the two main layers of tissue that make up the skin
compression arthralgia is pain in the joints caused by exposure to high ambient pressure at a relatively high rate of compression experienced by underwater divers also referred to in the us navy diving manual as compression pains compression arthralgia has been recorded as deep aching pain in the knees shoulders fingers back hips neck and ribs pain may be sudden and intense in onset and may be accompanied by a feeling of roughness in the joints onset commonly occurs around 60 msw meters of sea water and symptoms are variable depending on depth compression rate and personal susceptibility intensity increases with depth and may be aggravated by exercise compression arthralgia is generally a problem of deep diving particularly deep saturation diving where at sufficient depth even slow compression may produce symptoms peter b bennett et al showed that the use of trimix could reduce the symptoms fast compression descent may produce symptoms as shallow as 30 msw saturation divers generally compress much more slowly and symptoms are unlikely at less than around 90 msw at depths beyond 180 m even very slow compression may produce symptoms spontaneous improvement may occur over time at depth but this is unpredictable and pain may persist into decompression they may be distinguished from decompression sickness as they are present before starting decompression and resolve with decreasing pressure the opposite of decompression sickness the pain may be sufficiently severe to limit the diver s capacity for work and may also limit travel rate and depth of downward excursions
a compressor stall is a local disruption of the airflow in a gas turbine or turbocharger compressor it is related to compressor surge which is a complete disruption of the flow through the compressor stalls range in severity from a momentary power drop occurring so quickly it is barely registered on engine instruments to a complete loss of compression surge necessitating a reduction in the fuel flow to the engine stall was a common problem on early jet engines with simple aerodynamics and manual or mechanical fuel control units but has been virtually eliminated by better design and the use of hydromechanical and electronic control systems such as full authority digital engine controls modern compressors are carefully designed and controlled to avoid or limit stall within an engine s operating range
comproportionation or symproportionation is a chemical reaction where two reactants each containing the same element but with a different oxidation number will form a product in which the elements involved reach the same oxidation number for example an element a in the oxidation states 0 and 2 can comproportionate to the state 1 it is opposite to disproportionation where two or more atoms of the same element originally having the same oxidation state react with other chemical s or themselves to give different oxidation numbers
in the context of casinos comps are complimentary items and services given out by casinos to encourage players to gamble the amount of comps that a player is given usually depends on what game they play how much they bet and how long they play most casinos have casino hosts who are responsible for giving out free items and contacting players to bring them back to the casino pit bosses can also award comps at table games most casinos now require a player to have a player s club or similar card so that their play can be tracked and comps awarded most casinos give away promotional merchandise or swag just for standing in line
compton down is an extent of high ground near compton west sussex where there was an admiralty semaphore station the semaphore station was built at compton down in 1821 and it operated on the semaphore line from london to portsmouth between 1822 and 1847 the hill to the east of compton on which the semaphore was built is now known as telegraph hill the high ground to the west of compton retains the name of compton down both hills rise to above 500 feet 150 m
compucell 3 d is a three dimensional c software problem solving environment for simulations of biocomplexity problems integrating multiple mathematical morphogenesis models these include the cellular potts model cpm which can model cell clustering growth division death adhesion and volume and surface area constraints as well as partial differential equation solvers for modeling reaction diffusion of external chemical fields and cell type automata for differentiation by integrating these models compucell 3 d enables modeling of cellular reactions to external chemical fields such as secretion or resorption and responses such as chemotaxis and haptotaxis compucell 3 d is conducive for experimentation and testing biological models by providing a flexible and extensible package with many different levels of control high level steering is possible through compucellplayer an interactive gui built upon qt threads which execute in parallel with the computational back end functionality such as zooming rotation playing and pausing simulations setting colors and viewing cross sections is available through the player with a sample screenshot shown below extending the back end is possible through an xml based domain specific language biologo which after lexical analysis and generation transparently converts to c extensions which can be compiled and dynamically loaded at runtime the back end uses object oriented design patterns which contribute to extensibility reducing coupling between independently operating modules optional functionality can be encapsulated through plugins which are dynamically loaded at runtime through an xml configuration file reference compucell 3 d can model several different phenomena including avian limb development in vitro capillary development adhesion driven cell sorting dictyostelium discoideum and fluid flows the framework is accessible from the compucell 3 d website
compulsive hoarding also known as hoarding disorder is a pattern of behavior that is characterized by excessive acquisition and an inability or unwillingness to discard large quantities of objects that cover the living areas of the home and cause significant distress or impairment compulsive hoarding behavior has been associated with health risks impaired functioning economic burden and adverse effects on friends and family members when clinically significant enough to impair functioning hoarding can prevent typical uses of space enough so that it can limit activities such as cooking cleaning moving through the house and sleeping it can also put the individual and others at risk of fires falling poor sanitation and other health concerns compulsive hoarders may be aware of their irrational behavior but the emotional attachment to the hoarded objects far exceeds the motive to discard the items researchers have only recently begun to study hoarding and it was first defined as a mental disorder in the 5 th edition of the dsm in 2013 it was not clear whether compulsive hoarding is a separate isolated disorder or rather a symptom of another condition such as ocd but the current dsm lists hoarding disorder as both a mental disability and a possible symptom for ocd prevalence rates have been estimated at 2 to 5 in adults though the condition typically manifests in childhood with symptoms worsening in advanced age at which point collected items have grown excessive and family members who would otherwise help to maintain and control the levels of clutter either die or move away hoarding appears to be more common in people with psychological disorders such as depression anxiety and attention deficit hyperactivity disorder adhd other factors often associated with hoarding include alcohol dependence paranoid schizotypal and avoidance traits in 2008 a study was conducted to determine if there is a significant link between hoarding and interference in occupational and social functioning hoarding behavior is often severe because hoarders do not recognize it as a problem it is much harder for behavioral therapy to treat successfully compulsive hoarders with poor insight about their disorder results show that hoarders were significantly less likely to see a problem in a hoarding situation than a friend or a relative might this is independent of ocd symptoms as people with ocd are often very aware of their disorder the opposite condition is compulsive decluttering
a compulsory purchase order cpo is a legal function in the united kingdom and ireland that allows certain bodies which need to obtain land or property to do so without the consent of the owner it may be enforced if a proposed development is considered one for public betterment for example when building motorways where a land owner does not want to sell similarly if town councils wish to develop a town centre they may issue compulsory purchase orders in ireland cpos became quite common due to the massive road upgrade programme under the national development plan cpos are also used for rail projects if one objects to the issuing of a cpo one may appeal to the high court compensation is available to ensure that the person is restored as far as possible to the same position that they were in before the land and property were compulsorily purchased so that the person is left in the same financial position after the cpo as they were in before the process in the united kingdom most orders are made as subordinate legislation under powers given to local authorities in existing legislation e g an order for road works is made under the highways act 1980 whilst the powers are strong the authority must demonstrate that the taking of the land is necessary and there is a compelling case in the public interest owners or occupiers can challenge this and their objection will be heard by an independent inspector compensation rights usually include the value of the property costs of acquiring and moving to a new property and sometimes additional payments costs of professional advice regarding compensation are usually reimbursed by the authority so that people affected by a compulsory purchase order can seek advice from a solicitor and a surveyor and expect to be reimbursed
computability is the ability to solve a problem in an effective manner it is a key topic of the field of computability theory within mathematical logic and the theory of computation within computer science the computability of a problem is closely linked to the existence of an algorithm to solve the problem the most widely studied models of computability are the turing computable and μ recursive functions and the lambda calculus all of which have computationally equivalent power other forms of computability are studied as well computability notions weaker than turing machines are studied in automata theory while computability notions stronger than turing machines are studied in the field of hypercomputation
computational informatics is a subfield of informatics that emphasizes issues in the design of computing solutions rather than its underlying infrastructure computational informatics can also be interpreted as the use of computational methods in the information sciences
algorithmic topology or computational topology is a subfield of topology with an overlap with areas of computer science in particular computational geometry and computational complexity theory a primary concern of algorithmic topology as its name suggests is to develop efficient algorithms for solving topological problems using topological methods from computable topology to solve algorithmic problems from other fields
computer literacy is the ability to use computers and related technology efficiently with a range of skills covering levels from elementary use to programming and advanced problem solving computer literacy can also refer to the comfort level someone has with using computer programs and other applications that are associated with computers another valuable component is understanding how computers work and operate computer literacy may be distinguished from computer programming which is design and coding of computer programs rather than familiarity and skill in their use
computer vision syndrome cvs is a condition resulting from focusing the eyes on a computer or other display device for protracted uninterrupted periods of time some symptoms of cvs include headaches blurred vision neck pain redness in the eyes fatigue eye strain dry eyes irritated eyes double vision vertigo dizziness polyopia and difficulty refocusing the eyes these symptoms can be further aggravated by improper lighting conditions i e glare or bright overhead lighting or air moving past the eyes e g overhead vents direct air from a fan
in linear algebra the computation of the permanent of a matrix is a problem that is known to be more difficult than the computation of the determinant of a matrix despite the apparent similarity of the definitions the permanent is defined similarly to the determinant as a sum of products of sets of matrix entries that lie in distinct rows and columns however where the determinant weights each of these products with a ± 1 sign based on the parity of the set the permanent weights them all with a 1 sign while the determinant can be computed in polynomial time by gaussian elimination the permanent cannot in computational complexity theory a theorem of valiant states that computing permanents is p hard and even p complete for matrices in which all entries are 0 or 1 this puts the computation of the permanent in a class of problems believed to be even more difficult to compute than np it is known that computing the permanent is impossible for logspace uniform acc 0 circuits the development of both exact and approximate algorithms for computing the permanent of a matrix is an active area of research
concealed ovulation or hidden estrus in a species is the lack of any perceptible change in an adult female for instance a change in appearance or scent when she is in heat and near ovulation some examples of such changes are swelling and redness of the genitalia in baboons and bonobos pan paniscus and pheromone release in the feline family in contrast the females of humans and a few other species have few external signs of fecundity making it difficult for a mate to consciously deduce by means of external signs only whether or not a female is near ovulation in humans adult women s fertility peaks for a few days during each monthly cycle human females actually experience a wide range of menstrual cycle lengths and frequencies so the notion of a monthly cycle is better considered an average or shorthand therefore the frequency and length of fertility the time when a woman can become pregnant is highly variable between women and for each woman over the course of her lifespan humans are considered to have concealed ovulation because there is no outward physiological sign either to a woman herself or to others that ovulation or biological fertility is occurring knowledge of the fertility cycle learned through experience or from educational sources can allow a women to estimate her own level of fertility at a given time fertility awareness whether other humans in particular potential reproductive partners assumed to be men can detect fertility in women through behavioral or invisible biological cues is highly debated scientists and laypersons are interested in this question because it has implications for human social behavior and could theoretically offer biological explanations for some human sexual behavior however the science here is weak due to a relatively small number of studies several small studies have found that fertile women compared to women in infertile portions of the menstrual cycle or using hormonal contraception appear more attractive to men it has also been suggested that a woman s voice may become more attractive to men during this time two small studies of monogamous human couples found that women initiated sex significantly more frequently when fertile but male initiated sex occurred at a constant rate without regard to the woman s phase of menstrual cycle it may be that a woman s awareness of men s courtship signals increases during her highly fertile phase due to an enhanced olfactory awareness of chemicals specifically found in men s body odor analyses of data provided by the post 1998 u s demographic and health surveys found no variation in the occurrence of coitus in the menstrual phases except during menstruation itself this is contrary to other studies which have found female sexual desire and extra pair copulations epc s to increase during the midfollicular to ovulatory phases that is the highly fertile phase these findings of differences in woman initiated versus man initiated sex are likely caused by the woman ’ s subconscious awareness of her ovulation cycle because of hormone changes causing her to feel increased sexual desire contrasting with the man ’ s inability to detect ovulation because of its being “ hidden ” in 2008 researchers announced the discovery in human semen of hormones usually found in ovulating women they theorized that follicle stimulating hormone luteinising hormone and estradiol may encourage ovulation in women exposed to semen these hormones are not found in the semen of chimpanzees suggesting this phenomenon may be a human male counter strategy to concealed ovulation in human females other researchers are skeptical that the low levels of hormones found in semen could have any effect on ovulation one group of authors has theorized that concealed ovulation and menstruation were key factors in the development of symbolic culture in early human society
in the study of inhaled anesthetics the concentration effect is the increase in the rate that the fa alveolar concentration fi inspired concentration ratio rises as the alveolar concentration of that gas is increased in simple terms the higher the concentration of gas administered the faster the alveolar concentration of that gas approaches the inspired concentration in modern practice is only relevant for nitrous oxide since other inhaled anesthetics are delivered at much lower concentrations due to their higher potency
concentric hypertrophy is a hypertrophic growth of a hollow organ without overall enlargement in which the walls of the organ are thickened and its capacity or volume is diminished sarcomeres are added in parallel as for example occurs in hypertrophic cardiomyopathy in the heart concentric hypertrophy is related to increased pressure overload of the heart often due to hypertension and or aortic stenosis the consequence is a decrease in ventricular compliance and diastolic dysfunction followed eventually by ventricular failure and systolic dysfunction laplace s law for a sphere states wall stress t is proportionate to the product of the transmural pressure p and cavitary radius r and inversely proportionate to wall thickness w in response to the pressure overload left ventricular wall thickness markedly increases — while the cavitary radius remains relatively unchanged these compensatory changes termed concentric hypertrophy reduce the increase in wall tension observed in aortic stenosis
a concept over a domain x is a total boolean function over x a concept class is a class of concepts concept class is a subject of computational learning theory
a concerted reaction is a chemical reaction in which all bond breaking and bond making occurs in a single step reactive intermediates or other unstable high energy intermediates are not involved concerted reaction rates tend not to depend on solvent polarity ruling out large buildup of charge in the transition state the reaction is said to progress through a concerted mechanism as all bonds are formed and broken in concert pericyclic reactions the sn 2 reaction and some rearrangements such as the claisen rearrangement are concerted reactions the rate of the sn 2 reaction is second order overall due to the reaction being bimolecular i e there are two molecular species involved in the rate determining step the reaction does not have any intermediate steps only a transition state this means that all the bond making and bond breaking takes place in a single step in order for the reaction to occur both molecules must be situated correctly
conchobar an abaidh ó cellaigh king of uí maine chief of the name died 1403 following a lengthy period of stable rule from c 1349 to 1402 under the kings william buidhe and his son maelsechlainn conchobar s reign was the first of two successive short reigns though it is unclear if succession disputes were the cause of it conchobar was a son of maelsechlainn and nickname an abaidh because he was an abbot at an ui maine monastery the annals of the four masters report his death as follows conor anabaidh the son of melaghlin o kelly lord of hy many the serpent of his tribe and of all the irish people died after extreme unction and penance and was interred in the monastery of st john the baptist in tir many
concrescence is a condition of teeth where the cementum overlying the roots of at least two teeth join together the cause can sometimes be attributed to trauma or crowding of teeth surgical separation of the teeth may be necessary if one is to be extracted
concussion also known as minor head trauma is the most common type of traumatic brain injury it is typically defined as a head injury with a temporary loss of brain function symptoms include a variety of physical cognitive and emotional symptoms which may not be recognized if subtle a variety of signs accompany concussion including headache feeling in a fog and emotional changeability physical signs such as loss of consciousness or amnesia behavioral changes such as irritability cognitive impairment such as slowed reaction times or sleep disturbances fewer than 10 of sports related concussions among children are associated with loss of consciousness common causes include sports injuries bicycle accidents car accidents and falls the latter two being the most frequent causes among adults in addition to a blow to the head concussion may be caused by acceleration forces without a direct impact and on the battlefield mtbi is a potential consequence of nearby explosions it is not clear exactly what damage is done and how the symptoms are caused but stretching of axons and changes in ion channels are involved cellular damage has reportedly been found in concussed brains but it may have been due to artifacts from the studies it is currently thought that structural and neuropsychiatric factors may both be responsible for the effects of concussion treatment involves monitoring as well as physical and cognitive rest reduction of such activities as school work playing video games and text messaging symptoms usually resolve within three weeks though they may persist or complications may occur the rate at which concussion occurs is not accurately known but is estimated to be more than 6 per 1 000 people those who have had one concussion seem more susceptible to another especially if the new injury occurs before symptoms from the previous concussion have completely resolved there is also a negative progressive process in which smaller impacts cause the same symptom severity repeated concussions may increase the risk in later life for dementia parkinson s disease or depression
a condensation reaction is a chemical reaction in which two molecules or moieties often functional groups combine to form a larger molecule together with the loss of a small molecule possible small molecules that are lost include water hydrogen chloride methanol or acetic acid but most commonly in a biological reaction it is water when two separate molecules react the condensation is termed intermolecular a simple example is the condensation of two amino acids to form the peptide bond characteristic of proteins this reaction example is the opposite of hydrolysis which splits a chemical entity into two parts through the action of the polar water molecule which itself splits into hydroxide and hydrogen ions hence energy is required to form chemical bonds via condensation if the union is between atoms or groups of the same molecule the reaction is termed intramolecular condensation and in many cases leads to ring formation an example is the dieckmann condensation in which the two ester groups of a single diester molecule react with each other to lose a small alcohol molecule and form a β ketoester product
condensing osteitis is a periapical inflammatory disease that results from a reaction to a dental related infection this causes more bone production rather than bone destruction in the area most common site is near the root apices of premolars and molars the lesion appears as a radiopacity in the periapical area hence the sclerotic reaction the sclerotic reaction results from good patient immunity and a low degree of virulence of the offending bacteria the associated tooth may be carious or contains a large restoration and is usually associated with a non vital tooth
autism spectrum disorders asd including asperger syndrome are developmental disorders that begin in early childhood persist throughout adulthood and affect three crucial areas of development communication social interaction and restricted patterns of behavior there are many conditions comorbid to autism spectrum disorders such as fragile x syndrome and epilepsy in medicine and in psychiatry comorbidity is the presence of one or more additional conditions co occurring with the primary one or the effect of such additional disorders about 10 – 15 of autism cases have an identifiable mendelian single gene condition chromosome abnormality or other genetic syndrome and asd is associated with several genetic disorders perhaps due to an overlap in genetic causes distinguishing between asds and other diagnoses can be challenging because the traits of asds often overlap with symptoms of other disorders and the characteristics of asds make traditional diagnostic procedures difficult
conduct disorder cd is a mental disorder diagnosed in childhood or adolescence that presents itself through a repetitive and persistent pattern of behavior in which the basic rights of others or major age appropriate norms are violated these behaviors are often referred to as antisocial behaviors it is often seen as the precursor to antisocial personality disorder which is not diagnosed until the individual is 18 years old conduct disorder is estimated to affect 51 1 million people globally as of 2013
conduction aphasia also called associative aphasia is a relatively rare form of aphasia an acquired language disorder it is characterized by intact auditory comprehension fluent yet paraphasic speech production but poor speech repetition they are fully capable of understanding what they are hearing but show significant difficulty repeating phrases particularly as the phrases increase in length and complexity and as they stumble over words they are attempting to pronounce patients will display frequent errors during spontaneous speech such as substituting or transposing sounds they will also be aware of their errors and will show significant difficulty correcting them shallice and warrington 1970 were able to differentiate two variants ofthis constellation the reproduction and the repetition type these authors suggested an exclusive deficit of auditory verbal short termmemory in repetition conduction aphasia whereas the other variant was assumed to reflect disrupted phonological encoding mechanism afflicting confrontation tasks such as repetition reading and naming in a similar manner typical lesion location for conduction aphasia is on the supramarginal gyrus of the parietal lobe posterior to the primary sensory cortex and just above wernicke s area the classical explanation for conduction aphasia is that of a disconnection between the brain areas responsible for speech comprehension wernicke s area and speech production broca s area due specifically to damage to the arcuate fasciculus a deep white matter tract recent research has challenged this notion on the basis that patients with conduction aphasia more often have lesions in the supramarginal gyrus or deep parietal matter however conduction aphasia remains a controversial topic from the understanding of its neurologic foundations
conductive hearing loss occurs when there is a problem conducting sound waves anywhere along the route through the outer ear tympanic membrane eardrum or middle ear ossicles this type of hearing loss may occur in conjunction with sensorineural hearing loss mixed hearing loss or alone
conductor clashing is the phenomenon where conductors come in contact with one another during high wind speeds or gusts
conduplicato corpore is a condition that occurs during birth if the fetus is quite small and the pelvis is large spontaneous delivery may occur despite persistence of the abnormal lie in such cases the fetus is compressed with the head forced against the abdomen a portion of the thoracic wall below the shoulder thus becomes the most dependent part appearing at the vulva the head and thorax then pass through the pelvic cavity at the same time and the fetus which is doubled upon itself conduplicato corpore is expelled such a mechanism is obviously possible only in the case of very small infant and occasionally when the second preterm fetus in a twin pregnancy is born
condylar resorption also called idiopathic condylar resorption icr and condylysis is a temporomandibular joint disorder in which one or both of the mandibular condyles are broken down in a bone resorption process this disorder is nine times more likely to be present in females than males and is more common among teenagers
condylomata lata occurs in about one third of secondary syphilis patients and is characterized by painless mucosal and warty erosions which are flat velvety moist and broad base in nature they tend to develop in warm moist sites of the genitals and perineum these lesions hold a high accumulation of spirochetes and are highly infectious complete resolution of the lesions is spontaneous and occurs after a few days to many weeks where it is either resolved completely or enters the tertiary phase defined by a latent state
a cone dystrophy is an inherited ocular disorder characterized by the loss of cone cells the photoreceptors responsible for both central and color vision the most common symptoms of cone dystrophy are vision loss age of onset ranging from the late teens to the sixties sensitivity to bright lights and poor color vision therefore patients see better at dusk visual acuity usually deteriorates gradually but it can deteriorate rapidly to 20 200 later in more severe cases it drops to counting fingers vision color vision testing using color test plates hrr series reveals many errors on both red green and blue yellow plates the pathogenesis of cone dystrophy has yet to be elucidated it appears that the dystrophy is primary since subjective and objective abnormalities of cone function are found before ophthalmoscopic changes can be seen however the retinal pigment epithelium rpe rapidly becomes involved leading to a retinal dystrophy primarily involving the macula the histological examination of the eyes of one such patient showed that the outer nuclear layer of cones and rods had disappeared completely whereas the rpe showed pronounced pigment changes there was also atrophy of the temporal disc the fundus exam via ophthalmoscopy is essentially normal early on in cone dystrophy and definite macular changes usually occur well after visual loss fluorescein angiography fa is a useful adjunct in the workup of someone suspected to have cone dystrophy as it may detect early changes in the retina that are too subtle to be seen by ophthalmoscope for example fa may reveal areas of hyperfluorescence indicating that the rpe has lost some of its integrity allowing the underlying fluorescence from the choroid to be more visible these early changes are usually not detected during the ophthalmoscopic exam the most common type of macular lesion seen during ophthalmoscopic examination has a bull ’ s eye appearance and consists of a doughnut like zone of atrophic pigment epithelium surrounding a central darker area in another less frequent form of cone dystrophy there is rather diffuse atrophy of the posterior pole with spotty pigment clumping in the macular area rarely atrophy of the choriocapillaris and larger choroidal vessels is seen in patients at an early stage the inclusion of fluorescein angiography in the workup of these patients is important since it can help detect many of these characteristic ophthalmoscopic features in addition to the retinal findings temporal pallor of the optic disc is commonly observed as expected visual field testing in cone dystrophy usually reveals a central scotoma in cases with the typical bull ’ s eye appearance there is often relative central sparing because of the wide spectrum of fundus changes and the difficulty in making the diagnosis in the early stages electroretinography erg remains the best test for making the diagnosis abnormal cone function on the erg is indicated by a reduced single flash and flicker response when the test is carried out in a well lit room photopic erg the relative sparing of rod function in cone dystrophy is evidenced by a normal scotopic erg i e when the test is carried out in the dark in more severe or longer standing cases the dystrophy involves a greater proportion of rods with resultant subnormal scotopic records since cone dystrophy is hereditary and can be asymptomatic early on in the disease process erg is an invaluable tool in the early diagnosis of patients with positive family histories cone dystrophy in general usually occurs sporadically hereditary forms are usually autosomal dominant and instances of autosomal recessive and x linked inheritance also occur in the differential diagnosis other macular dystrophies as well as the hereditary optic atrophies must be considered fluorescent angiography erg and color vision tests are important tools to help facilitate diagnosis in early stages
in psychiatry confabulation verb confabulate is a disturbance of memory defined as the production of fabricated distorted or misinterpreted memories about oneself or the world without the conscious intention to deceive individuals who confabulate present incorrect memories ranging from subtle alterations to bizarre fabrications and are generally very confident about their recollections despite contradictory evidence
a confabulation also known as a false degraded or corrupted memory is a stable pattern of activation in an artificial neural network or neural assembly that does not correspond to any previously learned patterns the same term is also applied to the nonartificial neural mistake making process leading to a false memory confabulation
in artificial intelligence the confederate effect is the phenomenon of a human being considered a machine from their textual discourse during practical turing tests staged in the loebner prize for artificial intelligence it is the reverse of the eliza effect which sherry turkle states is our more general tendency to treat responsive computer programs as more intelligent than they really are and the cause to very small amounts of interactivity causing humans to project own complexity onto the undeserving object in the first loebner prize for artificial intelligence in 1991 which deployed restricted conversational one to one turing imitation games each interrogator chatted to one artificial conversational entity ace at a time a female confederate or hidden human about william shakespeare the phenomenon was seen in the university of surrey 2003 loebner prize for artificial intelligence when both hidden humans one male and one female were each ranked as machine by at least one judge judge 7 and judge 9 ranked the female confederate 2 as 1 00 definitely a machine the male confederate 1 was ranked 1 00 definitely a machine by judge 4 and judge 9 the gender of these two hidden humans were incorrectly identified male considered female woman considered man in independent transcript analysis gender blurring phenomenon see shah henry 2005
a confidential birth is a birth where the mother gives birth to a child without her identity being disclosed by the authorities in many countries confidential births have been legalized for centuries in order to prevent formerly frequent killings of newborn children particularly outside of marriage in a confidential birth the mother s right of informational self determination suspends the children s right to know about their biological ancestry until she changes her mind or until the grown up child requests disclosure at a later point the alternative concept of an anonymous birth where the mother doesn t disclose her identity to the authorities at all or where her identity remains infinitely undisclosed goes beyond this
in cultural and social studies configurations are patterns of behaviour movement → movement culture and thinking which research observes when analysing different cultures and or historical changes the term “ configurations ” is mostly used by comparative anthropological studies and by cultural history configurational analysis became a special method by the stuttgart school of historical behaviour studies during the 1970 s and later by body culture studies in denmark configurational analysis is marked by its distance towards the history of ideas and intentions which are conceived as mainstreams in historical studies configurations of human behaviour and movement have attracted special attention in the framework of phenomenology → phenomenology philosophy and particularly in materialist phenomenology
confiscation from the latin confiscatio joining to the fiscus i e transfer to the treasury is a legal seizure by a government or other public authority the word is also used popularly of spoliation under legal forms or of any seizure of property as punishment or in enforcement of the law
confluent and reticulated papillomatosis of gougerot and carteaud also known as confluent and reticulated papillomatosis crp carp familial cutaneous papillomatosis and familial occurrence of confluent and reticulated papillomatosis is an uncommon but distinctive acquired ichthyosiform dermatosis characterized by persistent dark scaly papules and plaques that tend to be localized predominantly on the central trunk
in mathematics a conformal map is a function that preserves angles locally in the most common case the function has a domain and an image in the complex plane more formally a map f u → v with u v ⊆ ℂn is called conformal or angle preserving at a point u 0 if it preserves oriented angles between curves through u 0 with respect to their orientation i e not just the magnitude of the angle conformal maps preserve both angles and the shapes of infinitesimally small figures but not necessarily their size or curvature the conformal property may be described in terms of the jacobian derivative matrix of a coordinate transformation if the jacobian matrix of the transformation is everywhere a scalar times a rotation matrix then the transformation is conformal conformal maps can be defined between domains in higher dimensional euclidean spaces and more generally on a riemannian or semi riemannian manifold
congenital absence of the vas deferens cavd is a condition in which the vasa deferentia reproductive organs fail to form properly prior to birth it may either be unilateral cuavd or bilateral cbavd
congenital adrenal hyperplasia cah are any of several autosomal recessive diseases resulting from mutations of genes for enzymes mediating the biochemical steps of production of mineralocorticoids glucocorticoids or sex steroids from cholesterol by the adrenal glands steroidogenesis most of these conditions involve excessive or deficient production of sex steroids and can alter development of primary or secondary sex characteristics in some affected infants children or adults
11 β hydroxylase deficient congenital adrenal hyperplasia 11 β oh cah is an uncommon form of congenital adrenal hyperplasia cah resulting from a defect in the gene encoding the enzyme steroid 11 β hydroxylase which mediates the final step of cortisol synthesis in the adrenal 11 β oh cah results in hypertension due to excessive mineralocorticoid effects it also causes excessive androgen production both before and after birth and can virilize a genetically female fetus or a child of either sex
congenital adrenal hyperplasia due to 21 hydroxylase deficiency 21 oh cah in all its forms accounts for over 95 of diagnosed cases of congenital adrenal hyperplasia and cah in most contexts refers to 21 hydroxylase deficiency an overview of the other types of cah is presented in the main article
congenital afibrinogenemia is a rare genetically inherited blood disorder in which the blood does not clot normally due to the lack of fibrinogen a blood protein necessary for coagulation this disorder is autosomal recessive meaning that two unaffected parents can have a child with the disorder the lack of fibrinogen expresses itself with excessive and at times uncontrollable bleeding
congenital amegakaryocytic thrombocytopenia camt is a rare inherited disorder
congenital amputation is birth without a limb or limbs or without a part of a limb or limbs it is known to be caused by blood clots forming in the fetus while in utero vascular insult and from amniotic band syndrome fibrous bands of the amnion that constrict foetal limbs to such an extent that they fail to form or actually fall off due to missing blood supply congenital amputation can also occur due to maternal exposure to teratogens during pregnancy
specific birth defects which can occur but certainly are not limited to the following list may include such congenital anomalies of spine or vertebral anomalies as fused ribs or missing vertebrae particularly in the spinal region some patients that have fused ribs must undergo replacement of the ribs with titanium ribs if their ribcages do not grow with the rest of the body the titanium ribs may have to be replaced multiple times throughout a patient ’ s lifetime if the sacral vertebrae are missing it generally causes no ill effect on the patient vertebral anomalies is associated with an increased incidence of some other specific anomalies as well together being called the vacterl association v vertebral anomalies a anal atresia c cardiovascular anomalies t tracheoesophageal fistula e esophageal atresia r renal kidney and or radial anomalies l limb defects
congenital anomaly of the genitalia is a medical term referring to any physical abnormality of the male or female internal or external genitalia present at birth this is a broad category of conditions some common and some rare
congenital bilateral perisylvian syndrome cbps is a rare neurological disease characterized by paralysis of certain facial muscles and epileptic seizures
congenital cartilaginous rest of the neck also known as a cervical accessory tragus and wattle is a cutaneous condition characterized by branchial arch remnants that are considered to be the cervical variant of accessory tragus
the term congenital cataract refers to a lens opacity present at birth congenital cataracts cover a broad spectrum of severity whereas some lens opacities do not progress and are visually insignificant others can produce profound visual impairment congenital cataracts may be unilateral or bilateral they can be classified by morphology presumed or defined genetic etiology presence of specific metabolic disorders or associated ocular anomalies or systemic findings
congenital chloride diarrhea ccd also congenital chloridorrhea or darrow gamble syndrome is a genetic disorder due to an autosomal recessive mutation on chromosome 7 the mutation is in downregulated in adenoma dra a gene that encodes a membrane protein of intestinal cells the protein belongs to the solute carrier 26 family of membrane transport proteins more than 20 mutations in the gene are known to date a rare disease ccd occurs in all parts of the world but is more common in some populations with genetic founder effects most notably in finland
beals syndrome congenital contractural arachnodactyly beals hecht syndrome is a rare congenital connective tissue disorder beals syndrome has only recently been described as a syndrome distinct from marfan s syndrome it was characterized in 1972 it is associated with fbn 2 it is caused by a mutation in fbn 2 gene on chromosome 5 q 23 contractures of varying degrees at birth mainly involving the large joints are present in all affected children elbows knees and fingers are most commonly involved the contractures may be mild and tend to reduce in severity but residual camptodactyly always remains present the arm span exceeds body height but the discrepancy may be underestimated due to contractures of elbows and fingers the same holds for the lower body portion with knee contractures the most serious complication in cca is scoliosis and sometimes kyphoscoliosis mandating surgery
congenital contractural arachnodactyly ca is a non lethal autosomal recessive genetic disorder in cattle an autosomal recessive defect is a disease caused by the presence of two recessive mutant genes on an autosome ca is classified as a heritable disorder of connective tissue specifically a disorder of the endomysium and perimysium the defect in the muscle connective tissue results in a reduced range of elastic extension ca is also known as fawn calf syndrome ca is predominately associated with angus cattle however it has also been detected in other angus associated breeds such as murray greys ca was first identified in victoria australia in 1998 however it has now been discovered in many other countries ca calves are almost always born alive most being able to walk and suckle on their mother s teat leading to their survival in the early stages although around 20 of ca calves die soon after birth differences in phenotypes are not normally noticeable and the weight of new born ca calves are seen to be normal this means that ca is not always recognised ca is caused by a specific error in the dna this means it can be passed on from parents to offspring any cattle known to carry any category one genetic condition such as ca cannot be registered with cattle societies the carriers of category 1 defects are all identifiable in the australian angus database ca calves that survive are exposed to joint dislocation and early onset of arthritis this is a result of their flexible joint laxity although ca is not as severe as other genetic diseases in cattle such as mannosidosis ma arthrogryposis multiplex am ca is nonetheless a cause of calf deaths in herds where prevalence of the ca mutation in the herd is high and carrier sires are still being used diagnosis of ca can be made with a physical examination of new born calves this should be done in the first 24 hours after birth preferably done by a veterinarian or experienced breeder despite the variations between severe and non severe cases ca is easily diagnosed in a live new born calf both males and females can be affected the following symptoms are observed congenital proximal limb contracture congenital distal limb hyperextension congenital kyphosis and significant postnatal improvement in these clinical signs as the calf grows and matures ca is not a difficult diagnosis however it requires careful physical examination of the calf followed by constant observation for improvement additional signs are present in the calves ca causes but can be more difficult to identify especially in mild cases these include abnormal long leg bones resulting in a tall stature loose jointedness poor muscling and knee knocking to prevent cattle being affected by ca sires should be pedigree analysed to minimise the chance of the mutation if ca is identified in a herd other bloodlines which have tested negative for ca should be purchased some predominant angus sires identified with ca are rambo 465 t of jrs te mania kelp k 207 bon view bando 598 saf 598 bando 5175 and boyd on target 1083
congenital cutaneous candidiasis previously known as beck ibrahim disease is a skin condition in newborn babies caused by premature rupture of membranes together with a birth canal infected with candida albicans
congenital cytomegalovirus infection refers to a condition where cytomegalovirus is transmitted in the prenatal period human cytomegalovirus is one of the vertically transmitted infections that lead to congenital abnormalities others are toxoplasmosis rubella and herpes simplex
congenital diaphragmatic hernia cdh is a birth defect of the diaphragm the most common type of cdh is a bochdalek hernia other types include morgagni hernia diaphragm eventration and central tendon defects of the diaphragm malformation of the diaphragm allows the abdominal organs to push into the chest cavity hindering proper lung formation cdh is a life threatening pathology in infants and a major cause of death due to two complications pulmonary hypoplasia and pulmonary hypertension experts disagree on the relative importance of these two conditions with some focusing on hypoplasia others on hypertension newborns with cdh often have severe respiratory distress which can be life threatening unless treated appropriately
a congenital disorder also known as a congenital disease deformity birth defect or anomaly is a condition existing at or before birth regardless of cause of these disorders those characterized by structural deformities are termed congenital anomalies and involve defects in a developing fetus birth defects vary widely in cause and symptoms any substance that causes birth defects is known as a teratogen some disorders can be detected before birth through prenatal diagnosis screening birth defects may be the result of genetic or environmental factors this includes errors of morphogenesis infection epigenetic modifications on a parental germline or a chromosomal abnormality the outcome of the disorder will depend on complex interactions between the pre natal deficit and the post natal environment animal studies indicate that the mother s and likely the father s diet vitamin intake and glucose levels prior to ovulation and conception have long term effects on fetal growth and adolescent and adult disease animal studies have shown that paternal exposures prior to conception and during pregnancy result in increased risk of certain birth defects and cancers this research suggests that paternal food deprivation germ line mutations alcohol use chemical mutagens age smoking habits and epigenetic alterations can affect birth outcomes however the relationship between offspring health and paternal exposures age and lifestyle are still relatively weak this is likely because paternal exposures and their effects on the fetus are studied far less extensively than maternal exposures birth defects are present in about 3 of newborns in usa congenital anomalies resulted in about 632 000 deaths per year in 2013 down from 751 000 in 1990 the type with the greatest numbers of deaths are congenital heart disease 323 000 followed by neural tube defects 69 000
a congenital disorder of glycosylation previously called carbohydrate deficient glycoprotein syndrome is one of several rare inborn errors of metabolism in which glycosylation of a variety of tissue proteins and or lipids is deficient or defective congenital disorders of glycosylation are sometimes known as cdg syndromes they often cause serious sometimes fatal malfunction of several different organ systems especially the nervous system muscles and intestines in affected infants the most common subtype is cdg ia also referred to as pmm 2 cdg where the genetic defect leads to the loss of phosphomannomutase 2 the enzyme responsible for the conversion of mannose 6 phosphate into mannose 1 phosphate
congenital disorder of glycosylation type iic or leukocyte adhesion deficiency 2 lad 2 is a type of leukocyte adhesion deficiency attributable to the absence of neutrophil sialyl lewisx a ligand of p and e selectin on vascular endothelium it is associated with slc 35 c 1 this disorder was discovered in two unrelated israeli boys 3 and 5 years of age each the offspring of consanguineous parents both had severe mental retardation short stature a distinctive facial appearance and the bombay hh blood phenotype and both were secretor and lewis negative they both had had recurrent severe bacterial infections similar to those seen in patients with lad 1 including pneumonia peridontitis otitis media and localized cellulitis similar to that in patients with lad 1 their infections were accompanied by pronounced leukocytosis 30 000 to 150 000 mm 3 but an absence of pus formation at sites of recurrent cellulitis in vitro studies revealed a pronounced defect in neutrophil motility because the genes for the red blood cell h antigen and for the secretor status encode for distinct α 1 2 fucosyltransferases and the synthesis of sialyl lewisx requires an α 1 3 fucosyltransferase it was postulated that a general defect in fucose metabolism is the basis for this disorder it was subsequently found that gdp l fucose transport into golgi vesicles was specifically impaired and then missense mutations in the gdp fucose transporter cdna of three patients with lad 2 were discovered thus gdp fucose transporter deficiency is a cause of lad 2
inborn errors of amino acid metabolism are metabolic disorders which impair the synthesis and degradation of amino acids types include alkaptonuria aspartylglucosaminuria methylmalonic acidemia maple syrup urine disease homocystinuria tyrosinemia trimethylaminuria hartnup disease biotinidase deficiency ornithine carbamoyltransferase deficiency carbamoyl phosphate synthase i deficiency disease citrullinemia hyperargininemia hyperhomocysteinemia hypermethioninemia hyperlysinemias nonketotic hyperglycinemia propionic acidemia hyperprolinemia
congenital distal spinal muscular atrophy is caused by a mutation of the trpv 4 gene found on the 12 q 23 12 q 24 1 the mutation causes an affected individual to have lower levels of trpv 4 expression this deficiency can lead to abnormal osmotic regulation congenital dsma is genetically heterogeneous meaning a mutation on this gene can cause a plethora of other phenotypically related or phenotypically unrelated diseases depending on the region that is mutated
congenital dyserythropoietic anemia cda is a rare blood disorder similar to the thalassemias cda is one of many types of anemia characterized by ineffective erythropoiesis and resulting from a decrease in the number of red blood cells rbcs in the body and a less than normal quantity of hemoglobin in the blood
congenital dyserythropoietic anemia type i cda i is a disorder of blood cell production particularly ofthe production of erythroblasts which are the precursors of the red blood cells rbcs
congenital dyserythropoietic anemia type ii cda ii or hereditary erythroblastic multinuclearity with positive acidified serum lysis test hempas is a rare genetic anemia in humans characterized by hereditary erythroblastic multinuclearity with positive acidified serum lysis test
congenital dyserythropoietic anemia type iii cda iii is a rare autosomal dominant disorder characterized by macrocytic anemia bone marrow erythroid hyperplasia and giant multinucleate erythroblasts new evidence suggests that this may be passed on recessively as well
congenital dyserythropoietic anemia type iv cda iv has been described with typical morphologic features of cda ii but a negative acidified serum test
the congenital epulis is a proliferation of cells on the upper jaw at birth this is more commonly found in female babies the cause of this type of epulis is unknown
congenital erosive and vesicular dermatosis is a cutaneous condition characterized by generalized erosions vesicles crusting and ‘ scalded skin like ’ erythematous areas affecting up to 75 of the body surface area
congenital estrogen deficiency is a genetic condition by which the body is unable to produce or use estrogens conditions include aromatase deficiency a condition where the enzyme aromatase is absent and androgens are not converted to estrogens estrogen insensitivity syndrome a condition where the estrogen receptor is defective and estrogen are not biologically active
congenital fibrosis of the extraocular muscles or cfeom is a class of rare genetic disorders affecting one or more of the muscles that move the eyeballs individuals with cfeom have varying degrees of ophthalmoplegia an inability to move the eyes in one or more directions and ptosis the condition is present from birth and non progressive runs in families and usually affects both eyes similarly in the most common form the superior recti are dysfunctional and the inferior recti lacking proper opposition pull the eyes down forcing the head to be tilted upward in order to see straight ahead there are three types of cfeom numbered 1 3 cfeom 1 the most common type is now known to be caused by one of several mutations in the kif 21 a gene while cfeom 2 is caused by mutations in the phox 2 a gene cfeom 3 is caused by mutations in the tubb 3 gene cfeom was first named in 1956 although papers describing conditions now known or assumed to be cfeom appear in the medical literature as early as 1840 due to its rarity it has been independently cited numerous times under many different names
for acquired fourth nerve palsy see fourth nerve palsy congenital fourth nerve palsy is a condition present at birth characterized by a vertical misalignment of the eyes due to a weakness or paralysis of the superior oblique muscle other names for fourth nerve palsy include superior oblique palsy and trochlear nerve palsy when looking to the right left the nerve muscle isn t strong enough or is too long and the eye drifts up
congenital generalized lipodystrophy also known as berardinelli – seip syndrome is an extremely rare autosomal recessive skin condition characterized by an extreme scarcity of fat in the subcutaneous tissues only 250 cases of the condition have been reported and it is estimated that it occurs in 1 in 10 million people worldwide
congenital hearing loss is a hearing loss present at birth it can include hereditary hearing loss or hearing loss due to other factors present either in utero prenatal or at the time of birth
congenital heart defect chd also known as a congenital heart anomaly or congenital heart disease is a problem in the structure of the heart that is present at birth signs and symptoms depend on the specific type of problem symptoms can vary from none to life threatening when present they may include rapid breathing bluish skin poor weight gain and feeling tired it does not cause chest pain most congenital heart problems do not occur with other diseases complications that can result from heart defects include heart failure the cause of a congenital heart defect is often unknown certain cases may be due to infections during pregnancy such as rubella use of certain medications or drugs such as alcohol or tobacco parents being closely related or poor nutritional status or obesity in the mother having a parent with a congenital heart defect is also a risk factor a number of genetic conditions are associated with heart defects including down syndrome turner syndrome and marfan syndrome congenital heart defects are divided into two main groups cyanotic heart defects and non cyanotic heart defects depending on whether the child has the potential to turn bluish in color the problems may involve the interior walls of the heart the heart valves or the large blood vessels that lead to and from the heart congenital heart defects are partly preventable through rubella vaccination the adding of iodine to salt and the adding of folic acid to certain food products some defects do not need treatment other may be effectively treated with catheter based procedures or heart surgery occasionally a number of operations may be needed occasionally heart transplantation is required with appropriate treatment outcomes even with complex problems are generally good heart defects are the most common birth defect in 2013 they were present in 34 3 million people globally they affect between 4 and 75 per 1 000 live births depending upon how they are diagnosed about 6 to 19 per 1 000 cause a moderate to severe degree of problems congenital heart defects are the leading cause of birth defect related deaths in 2013 they resulted in 323 000 deaths down from 366 000 deaths in 1990
congenital hemolytic anemia or hereditary hemolytic anemia refers to hemolytic anemia which is primarily due to congenital disorders
congenital hepatic fibrosis is an inherited fibrocystic liver disease associated with proliferation of interlobular bile ducts within the portal areas and fibrosis that do not alter hepatic lobular architecture the fibrosis would affect resistance in portal veins leading to portal hypertension
congenital hyperinsulinism is a medical term referring to a variety of congenital disorders in which hypoglycemia is caused by excessive insulin secretion congenital forms of hyperinsulinemic hypoglycemia can be transient or persistent mild or severe these conditions are present at birth and most become apparent in early infancy the severe forms can cause obvious problems in the first hour of life but milder forms may not be detected until adult years mild cases can be treated by frequent feedings more severe cases can be controlled by medications that reduce insulin secretion or effects
congenital hypertrophy of the lateral fold of the hallux is a rare cutaneous condition of unknown pathology that present to newborns the condition was first described by martinet et al in 1984 this sometimes painful condition involves an overgrowth of the soft tissue that can partially cover the nail plate the condition usually effects both extremities and the condition can later reverse spontaneously
congenital hypothyroidism ch is a condition of thyroid hormone deficiency present at birth approximately 1 in 4000 newborn infants has a severe deficiency of thyroid function while even more have mild or partial degrees if untreated for several months after birth severe congenital hypothyroidism can lead to growth failure and permanent intellectual disability treatment consists of a daily dose of thyroid hormone thyroxine by mouth because the treatment is simple effective and inexpensive nearly all of the developed world practices newborn screening to detect and treat congenital hypothyroidism in the first weeks of life
congenital ichthyosiform erythroderma cie also known as nonbullous congenital ichthyosiform erythroderma is a rare type the ichthyosis family of skin diseases which occurs in 1 in 200 000 to 300 000 births
congenital insensitivity to pain cip also known as congenital analgesia is one or more rare conditions in which a person cannot feel and has never felt physical pain the conditions described here are separate from the hsan group of disorders which have more specific signs and etiology it is an extremely dangerous condition
congenital insensitivity to pain with anhidrosis cipa also called hereditary sensory and autonomic neuropathy type iv is an extremely rare inherited disorder of the nervous system which prevents the sensation of pain heat cold or any real nerve related sensations including feeling the need to urinate however patients can still feel pressure cipa is the fourth type of hereditary sensory and autonomic neuropathy hsan known as hsan iv it is also referred to as hsan type iv a person with cipa cannot feel pain or differentiate even extreme temperatures anhidrosis means the body does not sweat and congenital indicates that the condition is present from birth
congenital nasolacrimal duct obstruction cldo is the condition in which a tear duct has failed to open at the time of birth around 6 of infants have cldo usually experiencing a persistent watery eye even when not crying the condition is also known as dacryostenosis if a secondary infection occurs dacryocystitis purulent yellow green discharge may be present
congenital lactic acidosis cla is a rare disease caused by mutations in mitochondrial dna mtdna that affect the ability of cells to use energy and cause too much lactic acid to build up in the body a condition called lactic acidosis
congenital limb deformities are congenital musculoskeletal disorders which primarily affect the upper and lower limbs an example is polydactyly
congenital lip pits also known as congenital sinus of the lower lip lip sinus and midline sinus of the upper lip is a congenital disorder characterized by the presence of pits and possibly associated fistulas in the lips they are often hereditary and may occur alone or in association with cleft lip and palate termed van der woude syndrome they are divided into three types based on their location commissural upper lip lower lip in some cases commissural pits have been reported in combination with preauricaluar pits lip pits are harmless and do not usually require any treatment although in some reported cases surgical excision has been used
congenital lobar emphysema cle also known as congenital lobar overinflation and infantile lobar emphysema is a neonatal condition associated with enlarged air spaces in the lungs of newborn children it is usually diagnosed around the time of birth or in the first 6 months of life occurring more often in boys than girls cle affects the upper lung lobes more than the lower lobes and the left lung more often than the right lung although cle may be caused by abnormal development of airways bronchi for example or compression of airways by nearby tissues no cause is identified in half of cases
congenital malformations of the dermatoglyphs are a cutaneous condition divided into four main categories based on the appearance of the dermal ridges of which they are composed 1 ridge aplasia 2 ridge hypoplasia 3 ridge dissociation and 4 ridges off the end
the congenital melanocytic nevus is a type of melanocytic nevus or mole found in infants at birth this type of birthmark occurs in an estimated 1 of infants worldwide it is located in the area of the head and neck 15 of the time
congenital muscular dystrophies are autosomal recessively inherited muscle diseases they are a group of heterogeneous disorders characterized by muscle weakness which is present at birth and the different changes on muscle biopsy that ranges from myopathic to overtly dystrophic due to the age at which the biopsy takes place
congenital myasthenic syndrome cms is an inherited neuromuscular disorder caused by defects of several types at the neuromuscular junction the effects of the disease are similar to lambert eaton syndrome and myasthenia gravis the difference being that cms is not an autoimmune disorder
congenital myopathy is a very broad term for any muscle disorder present at birth this defect primarily affects skeletal muscle fibres and causes muscular weakness and or hypotonia congenital myopathies account for one of the top neuromuscular disorders in the world today comprising approximately 6 in 100 000 live births every year as a whole congenital myopathies can be broadly classified as follows a distinctive abnormality in skeletal muscle fibres on the cellular level observable via light microscope symptoms of muscle weakness and hypotonia is a congenital disorder meaning it occurs during development and symptoms present themselves at birth or in early life is a genetic disorder
congenital nephrotic syndrome is an inherited disorder characterized by protein in the urine and swelling of the body
congenital pulmonary airway malformation cpam formerly known as congenital cystic adenomatoid malformation ccam is a congenital disorder of the lung similar to bronchopulmonary sequestration in cpam usually an entire lobe of lung is replaced by a non working cystic piece of abnormal lung tissue this abnormal tissue will never function as normal lung tissue the underlying cause for cpam is unknown it occurs in approximately 1 in every 30 000 pregnancies in most cases the outcome of a fetus with cpam is very good in rare cases the cystic mass grows so large as to limit the growth of the surrounding lung and cause pressure against the heart in these situations the cpam can be life threatening for the fetus cpam can be separated into five types based on clinical and pathologic features cpam type 1 is the most common with large cysts and a good prognosis cpam type 2 with medium sized cysts often has a poor prognosis owing to its frequent association with other significant anomalies other types are rare
congenital rubella syndrome crs can occur in a developing fetus of a pregnant woman who has contracted rubella usually in the first trimester if infection occurs 0 – 28 days before conception the infant has a 43 risk of being affected if the infection occurs 0 – 12 weeks after conception the risk increases to 51 if the infection occurs 13 – 26 weeks after conception the risk is 23 of the infant being affected by the disease infants are not generally affected if rubella is contracted during the third trimester or 26 – 40 weeks after conception problems rarely occur when rubella is contracted by the mother after 20 weeks of gestation and continues to disseminate the virus after birth it was discovered in 1941 by australian norman mcalister gregg the molecular basis for the causation of congenital rubella syndrome are not yet completely clear but in vitro studies with cell lines showed that rubella virus has an apoptotic effect on certain cell types there is evidence for a p 53 dependent mechanism
congenital self healing reticulohistiocytosis also known as hashimoto – pritzker disease and hashimoto – pritzker syndrome is a condition that is a self limited form of langerhans cell histiocytosis
congenital stenosis of vena cava is a congenital anomaly in which the superior vena cava or inferior vena cava has an aberrant interruption or coarctation in some cases it can be asymptomatic
congenital syphilis is syphilis present in utero and at birth and occurs when a child is born to a mother with syphilis untreated early syphilis infections results in a high risk of poor pregnancy outcomes including saddle nose lower extremity abnormalities miscarriages premature births stillbirths or death in neonates some infants with congenital syphilis have symptoms at birth but many develop symptoms later babies exposed in utero can have deformities delays in development or seizures along with many other problems such as rash fever hepatosplenomegaly anemia and jaundice newborns will typically not develop a primary syphilitic chancre but may present with signs of secondary syphilis i e generalized body rash often these babies will develop syphilitic rhinitis snuffles the mucus from which is laden with the t pallidum bacterium and therefore highly infectious rarely the symptoms of syphilis go unseen in infants so that they develop the symptoms of latent syphilis including damage to their bones teeth eyes ears and brain
congenital tufting enteropathy is an inherited disorder of the small intestine that presents with intractable diarrhea in young children
congestive hepatopathy also known as nutmeg liver and chronic passive congestion of the liver is liver dysfunction due to venous congestion usually due to congestive heart failure the gross pathological appearance of a liver affected by chronic passive congestion is speckled like a grated nutmeg kernel the dark spots represent the dilated and congested hepatic venules and small hepatic veins the paler areas are unaffected surrounding liver tissue when severe and longstanding hepatic congestion can lead to fibrosis if congestion is due to right heart failure it is called cardiac cirrhosis
conic optimization is a subfield of convex optimization that studies a class of structured convex optimization problems called conic optimization problems a conic optimization problem consists of minimizing a convex function over the intersection of an affine subspace and a convex cone the class of conic optimization problems is a subclass of convex optimization problems and it includes some of the most well known classes of convex optimization problems namely linear and semidefinite programming
conidiobolomycosis is a fungal disease it is caused by conidiobolus coronatus or conidiobolus incongruus
conjoined twins are identical twins joined in utero an extremely rare phenomenon the occurrence is estimated to range from 1 in 49 000 births to 1 in 189 000 births with a somewhat higher incidence in southeast asia africa and brazil approximately half are stillborn and an additional one third die within 24 hours most live births are female with a ratio of 3 1 most stillborns are male two contradicting theories exist to explain the origins of conjoined twins the more generally accepted theory is fission in which the fertilized egg splits partially the other theory no longer believed to be the basis of conjoined twinning is fusion in which a fertilized egg completely separates but stem cells which search for similar cells find like stem cells on the other twin and fuse the twins together conjoined twins share a single common chorion placenta and amniotic sac although these characteristics are not exclusive to conjoined twins as there are some monozygotic but non conjoined twins who also share these structures in utero the most famous pair of conjoined twins was chang and eng bunker thai อิน จัน in chan 1811 – 1874 thai brothers born in siam now thailand they traveled with p t barnum s circus for many years and were labeled as the siamese twins chang and eng were joined by a band of flesh cartilage and their fused livers at the torso in modern times they could have been easily separated due to the brothers fame and the rarity of the condition the term siamese twins came to be used as a synonym for conjoined twins
in abstract algebra a conjugacy class sum or simply class sum is a function defined for each conjugacy class of a finite group g as the sum of the elements in that conjugacy class the class sums of a group form a basis for the center of the associated group algebra
conjugate gaze palsies are neurological disorders affecting the ability to move both eyes in the same direction these palsies can affect gaze in a horizontal upward or downward direction these entities overlap with ophthalmoparesis and ophthalmoplegia
concretion in the palpebral conjunctiva is called conjunctival concretion that is a or a cluster small hard yellowish white calcified matter superficially buried beneath the palpebral conjunctiva most of concretions in the eye form in the palpebral conjunctiva which is a clear membrane to surround the inside of the eyelid less can be located in the cornea and retina
conjunctival squamous cell carcinoma conjunctival scc and corneal intraepithelial neoplasia comprise what are called ocular surface squamous cell neoplasias scc is the most common malignancy of the conjunctiva in the us with a yearly incidence of 1 2 8 per 100 000 risk factors for the disease are exposure to sun specifically occupational exposure to uvb and light colored skin other risk factors include radiation smoking hpv arsenic and exposure to polycyclic hydrocarbons conjunctival scc is often asymptomatic at first but it can present with the presence of a growth red eye pain itching burning tearing sensitivity to light double vision and decreased vision spread of conjunctival scc can occur in 1 21 of cases with the first site of spread being the regional lymph nodes mortality for conjunctival scc ranges from 0 8 diagnosis is often made by biopsy as well as ct in the case of invasive scc treatment of conjunctival scc is usually surgical excision followed by cryotherapy after this procedure conjunctival scc can recur 8 40 of the time radiation treatment topical mitomycin c and removal of the contents of the orbit or exenteration are other methods of treatment close follow up is recommended because the average time to recurrence is 8 – 22 months
conjunctivitis also known as pink eye is inflammation of the outermost layer of the white part of the eye and the inner surface of the eyelid it makes the eye appear pink or reddish there may also be pain burning scratchiness or itchiness the affected eye may have increased tears or be stuck shut in the morning swelling of the white part of the eye may also occur itching of the eye is more common in cases due to allergies conjunctivitis can affect one or both eyes the most common infectious causes are viral followed by bacterial the viral infection may occur along with other symptoms of a common cold viral and bacterial cases are easily spread between people allergies to pollen or animal hair is also a common cause diagnosis is often based on signs and symptoms occasionally a sample of the discharge is sent for culture prevention is partly by handwashing treatment depends on the underlying cause in the majority of viral cases there is no specific treatment most cases due to a bacterial infection will also resolve without treatment however antibiotics can shorten the illness those who wear contact lens and those with either gonorrhea or chlamydia as the cause should be treated allergic cases can be treated with antihistamine or mast cell inhibitor drops about 3 to 6 million people get conjunctivitis each year in the united states in adults viral causes are more common while in children bacterial causes are more common typically people get better in one or two weeks if there is visual loss significant pain sensitivity to light signs of herpes or a person is not improving after a week further diagnosis and treatment may be required conjunctivitis in a newborn known as neonatal conjunctivitis may also require specific treatment
connecticut repertory theatre crt at the storrs campus of the university of connecticut is the professional theatre run by the department of dramatic arts a part of the school of fine arts although a part of a university the crt is a major presence in the theatre world and sells more than twelve thousand tickets each year crt offers a subscription series of six plays and musicals each year — two in the 116 seat studio theatre two in the 240 seat nafe katter theatre and two in the 485 seat harriet s jorgensen theatre productions range from dramas such as the children s hour by lillian hellman to more light hearted fare such as the odd couple by neil simon prominent theatre personalities who have appeared in crt productions include actors kim hunter judy kaye and aleta mitchell directors james warwick and larry carpenter choreographer tony stevens and designer dennis parichy the new york times said of the crt theater lovers desperately seeking a touch of class to assuage the ache of tony fallout should drive to the university of connecticut at storrs for an essential restorative by the connecticut repertory theater crt and the department of dramatic arts also run the internationally renowned puppet arts program
the connecting stalk is a yolk sac diverticulum it is derived from extraembryonic mesoderm eventually it forms the umbilical cord
a connective tissue disease is any disease that has the connective tissues of the body as a target of pathology connective tissue is any type of biological tissue with an extensive extracellular matrix that supports binds together and protects organs these tissues form a framework or matrix for the body and are composed of two major structural protein molecules collagen and elastin there are many different types of collagen protein in each of the body s tissues elastin has the capability of stretching and returning to its original length — like a spring or rubber band elastin is the major component of ligaments tissues that attach bone to bone and skin in patients with connective tissue disease it is common for collagen and elastin to become injured by inflammation many connective tissue diseases feature abnormal immune system activity with inflammation in tissues as a result of an immune system that is directed against one s own body tissues autoimmunity diseases in which inflammation or weakness of collagen tends to occur are also referred to as collagen diseases collagen vascular diseases can be but are not necessarily associated with collagen and blood vessel abnormalities and that are autoimmune in nature see also vasculitis connective tissue diseases can have strong or weak inheritance risks and can also be caused by environmental factors
a connective tissue neoplasm connective tissue tumor is a neoplasm arising from the tissues of the connective tissue not all tumors in the connective tissue are of the connective tissue
a connective tissue nevus also known as a collagenoma elastoma and shagreen patch may be present at birth or appear within the first few years is elevated soft to firm varying from 0 5 to several centimeters in diameter and may be grouped linear or irregularly distributed
conorenal syndrome also called mainzer saldino syndrome or saldino mainzer disease is a collection of medical conditions that seem to have a common genetic cause
a conoscopic interference pattern or interference figure is a pattern of birefringent colours crossed by dark bands or isogyres which can be produced using a geological petrographic microscope for the purposes of mineral identification and investigation of mineral optical and chemical properties the figures are produced by optical interference when diverging light rays travel through an optically non isotropic substance that is one in which the substance s refractive index varies in different directions within it the figure can be thought of as a map of how the birefringence of a mineral would vary with viewing angle away from perpendicular to the slide where the central colour is the birefringence seen looking straight down and the colours further from the centre equivalent to viewing the mineral at ever increasing angles from perpendicular the dark bands correspond to positions where optical extinction apparent isotropy would be seen in other words the interference figure presents all possible birefringence colours for the mineral at once viewing the interference figure is a foolproof way to determine if a mineral is optically uniaxial or biaxial if the figure is aligned correctly use of a sensitive tint plate in conjunction with the microscope allows the user to determine mineral optic sign and optic angle
conradi – hünermann syndrome also known as conradi – hünermann – happle syndrome happle syndrome and x linked dominant chondrodysplasia punctata is a type of chondrodysplasia punctata it is associated with the gene ebp gene and affects between one in 100 000 and one in 200 000 babies
in computer programming cons ˈkɒnz or ˈkɒns is a fundamental function in most dialects of the lisp programming language cons constructs memory objects which hold two values or pointers to values these objects are referred to as cons cells conses non atomic s expressions natses or cons pairs in lisp jargon the expression to cons x onto y means to construct a new object with cons i x i i y i the resulting pair has a left half referred to as the car the first element or content of address register and a right half the second element or content of decrement register referred to as the cdr it is loosely related to the object oriented notion of a constructor which creates a new object given arguments and more closely related to the constructor function of an algebraic data type system the word cons and expressions like to cons onto are also part of a more general functional programming jargon sometimes operators that have a similar purpose especially in the context of list processing are pronounced cons a good example is the operator in ml scala f and elm or the operator in haskell which adds an element to the beginning of a list
conscientiousness is the personality trait of being careful or vigilant conscientiousness implies a desire to do a task well conscientious people are efficient and organized as opposed to easy going and disorderly they exhibit a tendency to show self discipline act dutifully and aim for achievement they display planned rather than spontaneous behavior and they are generally organized and dependable they have a more functional anterior cingulate cortex acc than the average person it is manifested in characteristic behaviors such as being neat and systematic also including such elements as carefulness thoroughness and deliberation the tendency to think carefully before acting conscientiousness is one of the five traits of the five factor model of personality and is an aspect of what has traditionally been referred to as having character conscientious individuals are generally hard working and reliable they are also likely to be conformists when taken to an extreme they may also be workaholics perfectionists and compulsive in their behavior people who score low on conscientiousness tend to be laid back less goal oriented and less driven by success they also are more likely to engage in antisocial and criminal behavior
the consideration of future consequences cfc is a personality trait defined as the extent to which individuals consider the potential future outcomes of their current behaviour and the extent to which they are influenced by the imagined outcomes individuals who score highly on a measure such as the consideration of future consequences scale typically focus on the future implications of their behaviour whereas those low on cfc typically focus more on their immediate needs and concerns
in mathematics the constant problem is the problem of deciding if a given expression is equal to zero
constitutional symptoms refers to a group of symptoms that can affect many different systems of the body examples include weight loss fevers fevers of unknown origin hyperhidrosis generalized hyperhidrosis chronic pain fatigue dyspnea and malaise other examples include chills night sweats and decreased appetite generally they are very nonspecific with a vast number of diseases and conditions as potential cause thereby requiring further evaluation for any diagnosis
constitutionality is the condition of acting in accordance with an applicable constitution the status of a law a procedure or an act s accordance with the laws or guidelines set forth in the applicable constitution when one of these laws procedures or acts directly violates the constitution it is unconstitutional all the rest are considered constitutional until challenged and declared otherwise
the focal point of the communicative constitution of organizations is that “ organization is an effect of communication not its predecessor ” this approach also referred to as the cco perspective posits that elements of communication rather than being fixed in advance are reflexively constituted within the act of communication itself
in mathematics a constraint is a condition of an optimization problem that the solution must satisfy there are several types of constraints — primarily equality constraints inequality constraints and integer constraints the set of candidate solutions that satisfy all constraints is called the feasible set
constraint satisfaction problems csps are mathematical problems defined as a set of objects whose state must satisfy a number of constraints or limitations csps represent the entities in a problem as a homogeneous collection of finite constraints over variables which is solved by constraint satisfaction methods csps are the subject of intense research in both artificial intelligence and operations research since the regularity in their formulation provides a common basis to analyze and solve problems of many seemingly unrelated families csps often exhibit high complexity requiring a combination of heuristics and combinatorial search methods to be solved in a reasonable time the boolean satisfiability problem sat the satisfiability modulo theories smt and answer set programming asp can be roughly thought of as certain forms of the constraint satisfaction problem examples of simple problems that can be modeled as a constraint satisfaction problem include eight queens puzzle map coloring problem crosswords sudoku futoshiki kakuro cross sums numbrix hidato and many other logic puzzles these are often provided with tutorials of asp boolean sat and smt solvers in the general case constraint problems can be much harder and may not be expressible in some of these simpler systems real life examples include automated planning and resource allocation
constriction ring syndrome crs also known or misnamed as adam complex amniotic band sequence amniotic band syndrome amniotic disruption complex amniochorionic mesoblastic fibrous strings congenital amputation constriction band syndrome congenital constriction bands streeter bands tissue bands is a congenital disorder with unknown etiology because of the unknown etiology there are many different and sometimes wrong names see etiology it is a malformation due to intrauterine bands or rings that give deep grooves in most commonly distal extremities like fingers and toes in rare cases the constriction ring can form around other parts of the fetus and cause amputation or even intrauterine death see types and classification the anatomy proximal to the site of constriction or amputation is developmentally normal crs can be associated with other malformations with club foot being most common see also types and classification the precise configuration of the bands lymphedema and character of the amputations are not predictable and vary with each individual patient also more than one extremity is usually affected and it is rare for only one ring to present as an isolated malformation with no other manifestation of this syndrome
constrictive pericarditis is a medical condition characterized by a thickened fibrotic pericardium limiting the heart s ability to function normally in many cases the condition continues to be difficult to diagnose and therefore benefits from a good understanding of the underlying cause
in complexity theory a time constructible function is a function f from natural numbers to natural numbers with the property that f n can be constructed from n by a turing machine in the time of order f n the purpose of such a definition is to exclude functions that do not provide an upper bound on the runtime of some turing machine
consumer capitalism is a theoretical economic and social political condition in which consumer demand is manipulated in a deliberate and coordinated way on a very large scale through mass marketing techniques to the advantage of sellers this theory is controversial it suggests manipulation of consumer demand so potent that it has a coercive effect amounts to a departure from free market capitalism and has an adverse effect on society in general according to one source the power of such manipulation is not straightforward it depends upon a new kind of individualism projective individualism where persons use consumer capitalism to project the kind of person who they want to be some use the phrase as shorthand for the broader idea that the interests of other non business entities governments religions the military educational institutions are intertwined with corporate business interests and that those entities also participate in the management of social expectations through mass media
the term consumer revolution refers to the period from approximately 1600 to 1750 in england in which there was a marked increase in the consumption and variety of luxury goods and products by individuals from different economic and social backgrounds the consumer revolution marked a departure from the traditional mode of life that was dominated by frugality and scarcity to one of increasingly mass consumption in society
contact dermatitis is a type of inflammation of the skin it results from either exposure to allergens allergic contact dermatitis or irritants irritant contact dermatitis phototoxic dermatitis occurs when the allergen or irritant is activated by sunlight diagnosis of allergic contact dermatitis can often be supported by patch testing
contact granuloma also known as a contact ulcer is a condition where an ulcer is found in the vocal folds on the mucous membrane of the posterior third of the vocal cord vocal process where the vocal ligament attaches the most common cause of the condition is sustained periods of increased pressure on the vocal folds and is commonly seen in people who use their voice excessively such as singers john mayer for example gastroesophageal reflux disease is also thought to be a contributing factor in the development of contact ulcers
a contact high is a psychological phenomenon that occurs in otherwise sober people and animals who come into contact with someone who is under the influence of drugs it involves a supposed transfer of the physiological state of intoxication a glossary of drug users language from the 1970 s describes the term as a psychogenic trip without taking drugs by being close to somebody while he or she is on drugs the term is often incorrectly used to describe the high obtained by inhaling the smoke of other marijuana smokers in alexander shulgin s pihkal book under the 2 c i entry a notable reaction is observed in a participant who takes a placebo existing in an environment with other people who are under the drug s influence the participant wrote that he had absorbed the ambience of the folks who had actually imbibed the material
contagious bovine pleuropneumonia cbpp also known as lung plague is a contagious bacterial disease that afflicts the lungs of cattle buffalo zebu and yaks it is caused by the bacterium mycoplasma mycoides mycoides and the symptoms are pneumonia and inflammation of the lung membranes the incubation period is 20 to 123 days it was particularly widespread in the united states in 1879 affecting herds from several states the outbreak was so severe that it resulted in a trade embargo by the british government blocking u s cattle exports to britain and canada this prompted the united states to establish the bureau of animal industry set up in 1884 to eradicate the disease which it succeeded in doing louis willems a belgian doctor began pioneering work in the 1850 s on animal inoculation against the disease the bacteria are widespread in africa the middle east southern europe as well as parts of asia it is an airborne species and can travel up to several kilometres in the right conditions
contagious caprine pleuropneumonia ccpp is a cause of major economic losses to goat producers in africa asia and the middle east disease is caused by members of the mycoplasma genus usually mycoplasma capricolum subsp capricolum but sometimes by m mycoides subsp capri or m mycoides subsp mycoides it is extremely contagious with very high morbidity and mortality rates causing an interstitial fibrinous pleuropneumonia in infected goats infection is spread by close contact aerosol therefore overcrowding and confinement increases disease incidence stress factors such as malnutrition and long transport can also predispose animals to disease goats are the only species affected therefore the disease is not a zoonosis there is no age breed or sex predilection but clinical signs are often worse in younger animals
a contagious shooting is a sociological phenomenon observed in military and police personnel in the united states in which one person firing on a target can induce others to begin shooting often the subsequent shooters will not know why they are firing this is defined as officers firing because others are doing so or according to professor eugene j o donnell of john jay college cops shoot because other cops shoot while commonly accepted in popular culture and police jargon there has been yet no scientific evidence to prove the existence of a contagious shooting dynamic which o donnell said was a debatable notion additionally a former cia employee and fbi firearms instructor observed it in training consistently in every class officers would shoot at their target upon hearing others shoot even when their particular target board did not contain the called target he suggests that one reason it occurs is because of muscle memory t he targets turn or the whistle blows and all the officers shoot together until a cease fire signal is given o donnell partially reinforces this saying that in classic cases involving contagious shooting a gun was shot before any officers fired and thus the officers involved began shooting because of fear or because of the sound of a colleague firing
contaminated haemophilia blood products were a serious public health problem in the late 1970 s through 1985 these products caused large numbers of haemophiliacs to become infected with hiv and hepatitis c the companies involved included alpha therapeutic corporation institut mérieux which then became rhone poulenc rorer inc and is now part of sanofi bayer corporation and its cutter biological division baxter international and its hyland pharmaceutical division estimates range from 6 000 to 10 000 haemophiliacs in the united states becoming infected with hiv factor viii is a protein that helps the clotting of blood which haemophiliacs due to the genetic nature of their condition are unable to produce themselves by injecting themselves with it hemophiliacs can stop bleeding or prevent bleeding from starting some use it as often as three times a week
contamination is the presence of an unwanted constituent contaminant or impurity in a material physical body natural environment workplace etc
in digital circuits the contamination delay denoted as tcd is the minimum amount of time from when an input changes until any output starts to change its value this change in value does not imply that the value has reached a stable condition the contamination delay only specifies that the output rises or falls to 50 of the voltage level for a logic high the circuit is guaranteed not to show any output change in response to an input change before tcd time units calculated for the whole circuit have passed the determination of the contamination delay of a combined circuit requires identifying the shortest path of contamination delays from input to output and by adding each tcd time along this path for a sequential circuit such as two d flip flops connected in series the contamination delay of the first flip flop must be factored in to avoid violating the hold time constraint of the second flip flop receiving the output from the first flip flop here the contamination delay is the amount of time needed for a change in the flip flop clock input to result in the initial change at the flip flop output q if there is insufficient delay from the output of one flip flop to the input of the next the input may change before the hold time has passed because the second flip flop is still unstable its data would then be contaminated every path from an input to an output can be characterized with a particular contamination delay well balanced circuits will have similar speeds for all paths through a combinational stage so the minimum propagation time is close to the maximum this corresponding maximum time is the propagation delay the condition of data being contaminated is called a race
a contiguous gene syndrome cgs also known as a contiguous gene deletion syndrome is a clinical phenotype caused by a chromosomal abnormality such as a deletion or duplication that removes several genes lying in close proximity to one another on the chromosome the combined phenotype of the patient is a combination of what is seen when any individual has disease causing mutations in any of the individual genes involved in the deletion while it can be caused by deleted material on a chromosome it is not strictly speaking the same entity as a segmental aneuploidy syndrome a segmental aneuploidy syndrome is a subtype of cgs that regularly recur usually due to non allelic homologous recombination between low copy repeats in the region most cgs involve the x chromosome and affect male individuals one of the earliest and most famous examples of a cgs involves a male patient with duchenne muscular dystrophy dmd chronic granulomatous disease cgd retinitis pigmentosa and intellectual disability when it was discovered that an x chromosome deletion specifically xp 21 was the underlying cause of all of these features researchers were able to use this information to clone the genes responsible for dmd and cgd one of those more common cgs involves a deletion on the x chromosome near xp 21 that encompasses dmd causing duchenne muscular dystrophy nrob 1 causing x linked adrenal hypoplasia congenita and gk causing glycerol kinase deficiency these patients will have all the common features of each individual disease resulting in a very complex phenotype deletions near the distal tip of the p arm of the x chromosome are also a frequent cause of cgs in addition to the previously described cgs that occur on the x chromosome two other common syndromes are langer giedion syndrome caused by deletions of trps 1 and ext 1 on 8 q 24 and wagr syndrome caused by deletions on 11 q 13 encompassing pax 6 and wt 1
continental germanic mythology is a subtype of germanic paganism as practiced in parts of central europe during the 6 th to 8 th centuries a period of christianization it continued in the legends and middle high german epics of the middle ages traces of these stories with the sacred elements largely removed may be found throughout european folklore and fairy tales
continental collision is a phenomenon of the plate tectonics of earth that occurs at convergent boundaries continental collision is a variation on the fundamental process of subduction whereby the subduction zone is destroyed mountains produced and two continents sutured together continental collision is known only to occur on earth continental collision is not an instantaneous event but may take several tens of millions of years before the faulting and folding caused by collisions stops the collision between india and asia has been going on for about 50 million years already and shows no signs of abating collision between east and west gondwana to form the east african orogen took about 100 million years from beginning 610 ma to end 510 ma collision between gondwana and laurasia to form pangea occurred in a relatively brief interval about 50 million years long
continuous distillation a form of distillation is an ongoing separation in which a mixture is continuously without interruption fed into the process and separated fractions are removed continuously as output streams distillation is the separation or partial separation of a liquid feed mixture into components or fractions by selective boiling or evaporation and condensation the process produces at least two output fractions these fractions include at least one volatile distillate fraction which has boiled and been separately captured as a vapor condensed to a liquid and practically always a bottoms or residuum fraction which is the least volatile residue that has not been separately captured as a condensed vapor an alternative to continuous distillation is batch distillation where the mixture is added to the unit at the start of the distillation distillate fractions are taken out sequentially in time one after another during the distillation and the remaining bottoms fraction is removed at the end because each of the distillate fractions are taken out at different times only one distillate exit point location is needed for a batch distillation and the distillate can just be switched to a different receiver a fraction collecting container batch distillation is often used when smaller quantities are distilled in a continuous distillation each of the fraction streams is taken simultaneously throughout operation therefore a separate exit point is needed for each fraction in practice when there are multiple distillate fractions the distillate exit points are located at different heights on a fractionating column the bottoms fraction can be taken from the bottom of the distillation column or unit but is often taken from a reboiler connected to the bottom of the column each fraction may contain one or more components types of chemical compounds when distilling crude oil or a similar feedstock each fraction contains many components of similar volatility and other properties although it is possible to run a small scale or laboratory continuous distillation most often continuous distillation is used in a large scale industrial process
in theoretical computer science the continuous knapsack problem also known as the fractional knapsack problem is an algorithmic problem in combinatorial optimization in which the goal is to fill a container the knapsack with fractional amounts of different materials chosen to maximize the value of the selected materials it resembles the classic knapsack problem in which the items to be placed in the container are indivisible however the continuous knapsack problem may be solved in polynomial time whereas the classic knapsack problem is np hard it is a classic example of how a seemingly small change in the formulation of a problem can have a large impact on its computational complexity
continuous obsolescence or perpetual revolution is a phenomenon where industry trends or other items that do not immediately correspond to technical needs mandate a continual readaptation of a system such work does not increase the usefulness of the system but is required for the system to continue fulfilling its functions
a muscle contracture is a permanent shortening of a muscle or joint it is usually in response to prolonged hypertonic spasticity in a concentrated muscle area such as is seen in the tightest muscles of people with conditions like spastic cerebral palsy contractures are essentially muscles or tendons that have remained too tight for too long thus becoming shorter once they occur it is often argued that they cannot be stretched or exercised away they must be released with orthopedic surgery most of the physical therapy occupational therapy and other exercise regimens targeted towards people with spasticity focuses on trying to prevent contractures from happening in the first place however research on sustained traction of connective tissue in approaches such as adaptive yoga has demonstrated that contracture can be reduced at the same time that tendency toward spasticity is addressed contractures can also be due to ischemia as in volkmann s contracture excessive matrix metalloproteinase and myofibroblast accumulation in the wound margins can result in contracture
in medicine a contraindication is a condition or factor that serves as a reason to withhold a certain medical treatment due to the harm that it would cause the patient contraindication is the opposite of indication which is a reason to use a certain treatment some contraindications are absolute meaning that there are no reasonable circumstances for undertaking a course of action for example children and teenagers with viral infections should not be given aspirin because of the risk of reye s syndrome and a person with an anaphylactic food allergy should never eat the food to which they are allergic similarly a person with hemochromatosis should not be administered iron preparations other contraindications are relative meaning that the patient is at higher risk of complications but these risks may be outweighed by other considerations or mitigated by other measures for example a pregnant woman should normally avoid getting x rays but the risk may be outweighed by the benefit of diagnosing and then treating a serious condition such as tuberculosis relative contraindications may also be referred to as cautions such as in the british national formulary
contrast induced nephropathy is defined as either a greater than 25 increase of serum creatinine or an absolute increase in serum creatinine of 0 5 mg dl after using iodine contrast agent without another clear cause for kidney injury despite extensive speculation the actual occurrence of contrast induced nephropathy in other patient populations has not been demonstrated in the literature
in music and musical form contrast is the difference between parts or different instrument sounds the three types of contrast are rhythmic contrast melodic contrast and harmonic contrast procedures of contrast include stratification juxtaposition and interpolation procedures of connection include gradation amalgamation and dissolution contrast is not only a way of addinginterest but is essential to the aesthetic illusion of dramatic resolution of conflict
contrast is the difference in luminance or colour that makes an object or its representation in an image or display distinguishable in visual perception of the real world contrast is determined by the difference in the color and brightness of the object and other objects within the same field of view the human visual system is more sensitive to contrast than absolute luminance we can perceive the world similarly regardless of the huge changes in illumination over the day or from place to place the maximum contrast of an image is the contrast ratio or dynamic range
a control premium is an amount that a buyer is sometimes willing to pay over the current market price of a publicly traded company in order to acquire a controlling share in that company if the market perceives that a public company s profit and cash flow is not being maximized capital structure is not optimal or other factors that can be changed are impacting the company s share price an acquirer may be willing to offer a premium over the price currently established by other market participants a discount for lack of control sometimes referred to as a minority discount reflects the reduction in value from a firm s perceived optimal or intrinsic value when cash flow or other factors prevent optimal value from being reached
control reversal is an adverse effect on the controllability of aircraft the flight controls reverse themselves in a way that is not intuitive so pilots may not be aware of the situation and therefore provide the wrong inputs in order to roll to the left for instance they have to push the control stick to the right the opposite of the normal direction
using controlled language in machine translation poses several problems in an automated translation the first step in order to understand the controlled language is to know what it is and to distinguish between natural language and controlled language the main problem in machine translation is a linguistic problem language is ambiguous and the system tries to model a language on lexical and grammatical way in order to solve this problem there are a lot of alternatives e g a glossary related with the text ’ s topic can be used
chronic fatigue syndrome cfs is an illness with a long history of controversy for years many professionals within the medical community did not recognize cfs as a true condition nor was there agreement on its prevalence there has been much disagreement over the pathophysiology of chronic fatigue syndrome how it should be diagnosed and how to treat it the diagnosis is controversial and its etiology is still not fully understood alternative names to describe the condition s have been used over time throughout the world patient groups have criticized the name chronic fatigue syndrome saying it trivializes the illness a major divide still exists as to whether funding should be directed towards biomedical or psychological research
in the field of fluid dynamics a convection cell is the phenomenon that occurs when density differences exist within a body of liquid or gas these density differences result in rising and or falling currents which are the key characteristics of a convection cell when a volume of fluid is heated it expands and becomes less dense and thus more buoyant than the surrounding fluid the colder denser part of the fluid descends to settle below the warmer less dense fluid and this causes the warmer fluid to rise such movement is called convection and the moving body of liquid is referred to as a convection cell this particular type of convection where a horizontal layer of fluid is heated from below is known as rayleigh bénard convection convection usually requires a gravitational field but in microgravity experiments thermal convection has been observed without gravitational effects fluids are generalized as materials that exhibit the property of flow however this behavior is not unique to liquids fluid properties can also be observed in gases and even in particulate solids such as sand gravel and larger objects during rock slides a convection cell is most notable in the formation of clouds with its release and transportation of energy as air moves along the ground it absorbs heat loses density and moves up into the atmosphere when it is forced into the atmosphere which has a lower air pressure it cannot contain as much fluid as at a lower altitude so it releases its moist air producing rain in this process the warm air is cooled it gains density and falls towards the earth and the cell repeats the cycle convection cells can form in any fluid including the earth s atmosphere where they are called hadley cells boiling water soup where the cells can be identified by the particles they transport such as grains of rice the ocean or the surface of the sun the size of convection cells is largely determined by the fluid s properties convection cells can even occur when the heating of a fluid is uniform
in meteorology convective available potential energy cape sometimes simply available potential energy ape is the amount of energy a parcel of air would have if lifted a certain distance vertically through the atmosphere cape is effectively the positive buoyancy of an air parcel and is an indicator of atmospheric instability which makes it very valuable in predicting severe weather it is a form of fluid instability found in thermally stratified atmospheres in which a colder fluid overlies a warmer one as explained below when an air mass is unstable the element of the air mass that is displaced upwards is accelerated by the pressure differential between the displaced air and the ambient air at the higher altitude to which it was displaced this usually creates vertically developed clouds from convection due to the rising motion which can eventually lead to thunderstorms it could also be created by other phenomena such as a cold front even if the air is cooler on the surface there is still warmer air in the mid levels that can rise into the upper levels however if there is not enough water vapor present there is no ability for condensation thus storms clouds and rain will not form
convective overshoot is a phenomenon of convection carrying material beyond an unstable region of the atmosphere into a stratified stable region overshoot is caused by the momentum of the convecting material which carries the material beyond the unstable region
convergence insufficiency or convergence disorder is a sensory and neuromuscular anomaly of the binocular vision system characterized by a reduced ability of the eyes to turn towards each other or sustain convergence
conversion disorder cd is a diagnostic category previously used in some psychiatric classification systems it is sometimes applied to patients who present with neurological symptoms such as numbness blindness paralysis or fits which are not consistent with a well established organic cause and which cause significant distress it is thought that these symptoms arise in response to stressful situations affecting a patient s mental health or an ongoing mental health condition such as depression conversion disorder was retained in dsm 5 but given the subtitle functional neurological symptom disorder the new criteria cover the same range of symptoms but remove the requirements for a psychological stressor to be present and for feigning to be disproved the theory of conversion disorder stems from ancient egypt and was formerly known as hysteria the concept of conversion disorder came to prominence at the end of the 19 th century when the neurologists jean martin charcot and sigmund freud and psychologist pierre janet focused their studies on the subject before their studies people with hysteria were often believed to be malingering the term conversion has its origins in freud s doctrine that anxiety is converted into physical symptoms though previously thought to have vanished from the west in the 20 th century some research has suggested that conversion disorder is as common as ever icd 10 classifies conversion disorder as a dissociative disorder while dsm iv classifies it as a somatoform disorder
in computer science specifically formal languages convolution sometimes referred to as zip is a function which maps a tuple of sequences into a sequence of tuples
a convulsion is a medical condition where body muscles contract and relax rapidly and repeatedly resulting in an uncontrolled shaking of the body because a convulsion is often a symptom of an epileptic seizure the term convulsion is sometimes used as a synonym for seizure however not all epileptic seizures lead to convulsions and not all convulsions are caused by epileptic seizures convulsions are also consistent with an electric shock and improper enriched air scuba diving for non epileptic convulsions see non epileptic seizures the word fit is sometimes used to mean a convulsion or epileptic seizure
the conway base 13 function is a function created by british mathematician john h conway as a counterexample to the converse of the intermediate value theorem in other words even though conway s function f is not continuous if f a f b and an arbitrary value x is chosen such that f a x f b a point c lying between a and b can always be found such that f c x in fact this function is even stronger than this it takes on every real value in each interval on the real line
conway s puzzle or blocks in a box is a packing problem using rectangular blocks named after its inventor mathematician john conway it calls for packing thirteen 1 × 2 × 4 blocks one 2 × 2 × 2 block one 1 × 2 × 2 block and three 1 × 1 × 3 blocks into a 5 × 5 × 5 box
cooks syndrome is a hereditary disorder which is characterized in the hands by bilateral nail hypoplasia on the thumb index finger and middle finger absence of fingernails anonychia on the ring finger and little finger lengthening of the thumbs and bulbousness of the fingers in the feet it is characterized by absence of toenails and absence hypoplasia of the distal phalanges in the second study of this disorder it was found that the intermediate phalanges proximal phalanges and metacarpals were unaffected the disorder was first described by cooks et al in 1985 after being discovered in two generations of one family it was proposed that the inheritance of the disorder is autosomal dominant a second family this with three affected generations confirmed that the inheritance of the disorder is autosomal dominant although several genetic disorders exist which can cause anonychia and onychodystrophy such disorders often cause other anomalies such as deafness mental retardation and defects of the hair eyes and teeth cooks syndrome is not known to cause any such anomalies in 1999 a pair of siblings was found with brachydactyly type b because the disorder primarily affected the nails and distal phalanges the research group concluded that brachydactyly type b and cooks syndrome are the same disorder however in 2007 a 2 year old girl was found with symptoms consistent with both brachydactyly type b and cooks syndrome it was found that the two syndromes were distinct clinically radiologically and genetically
the cook – heilbron thiazole synthesis is the chemical reaction of α aminonitriles with carbon disulfide to form 5 amino 2 mercapto thiazoles it is named after alan h cook and sir ian morris heilbron the cook heilbron thiazole synthesis
in biology and psychology the coolidge effect is a phenomenon seen in mammalian species whereby males and to a lesser extent females exhibit renewed sexual interest if introduced to new receptive sexual partners even after cessation of sex with prior but still available sexual partners the evolutionary benefit to this phenomenon is that a male can fertilize multiple females the male may be reinvigorated repeatedly for successful insemination of multiple females
coolie itch is a cutaneous condition caused by rhizoglyphus parasiticus characterized by an intense pruritus it is found in india on tea plantations and causes sore feet rhizoglyphus parasiticus is a type of mite
cooperativeness is a personality trait concerning the degree to which a person is generally agreeable in their relations with other people as opposed to aggressively self centred and hostile it is one of the character dimensions in cloninger s temperament and character inventory cloninger described it as relating to individual differences in how much people identify with and accept others cloninger s research found that low cooperativeness is associated with all categories of personality disorder cooperativeness is conceptually similar to and strongly correlated with agreeableness in the five factor model of personality
cooperativity is a phenomenon displayed by systems involving identical or near identical elements which act dependently of each other relative to a hypothetical standard non interacting system in which the individual elements are acting independently one manifestation of this is enzymes or receptors that have multiple binding sites where the affinity of the binding sites for a ligand is apparently increased positive cooperativity or decreased negative cooperativity upon the binding of a ligand to a binding site for example when an oxygen atom binds to one of hemoglobin s four binding sites the affinity to oxygen of the three remaining available binding sites increases i e oxygen is more likely to bind to a hemoglobin bound to one oxygen than to an unbound hemoglobin this is referred to as cooperative binding we also see cooperativity in large chain molecules made of many identical or nearly identical subunits such as dna proteins and phospholipids when such molecules undergo phase transitions such as melting unfolding or unwinding this is referred to as subunit cooperativity however the definition of cooperativity based on apparent increase or decrease in affinity to successive ligand binding steps is problematic as the concept of energy must always be defined relative to a standard state when we say that the affinity is increased upon binding of one ligand it is empirically unclear what we mean since a non cooperative binding curve is required to rigorously define binding energy and hence also affinity a much more general and useful definition of positive cooperativity is a process involving multiple identical incremental steps in which intermediate states are statistically underrepresented relative to a hypothetical standard system null hypothesis where the steps occur independently of each other likewise a definition of negative cooperativity would be a process involving multiple identical incremental steps in which the intermediate states are overrepresented relative to a hypothetical standard state in which individual steps occur independently these latter definitions for positive and negative cooperativity easily encompass all processes which we call cooperative including conformational transitions in large molecules such as proteins and even psychological phenomena of large numbers of people which can act independently of each other or in a co operative fashion
coordination failure is the electoral problem resulting from competition between two or more candidates or political parties from the same or approximate location in the political ideological spectrum or space against an opposing candidate or political party from the other side of the political ideological spectrum or space the resulting fragmentation of political support may result in electoral defeat coordination failures and thus political calculations attempting to avoid them appear most frequently in elections involving executives and representatives from single member districts coordination failure in a game theoretic context is a state of affairs in which agents inability to coordinate their behavior choices leads to an outcome equilibrium that leaves all agents worse off than in an alternative situation that is also an equilibrium this can occur due to lack of information inefficiencies or differing expectations
cooties is a fictional childhood disease used in the united states of america and canada as a rejection term and an infection tag game such as humans vs zombies it is similar to the british dreaded lurgi and to terms used in the nordic countries in italy and in new zealand a child is said to catch cooties through close contact with an infected person or from an opposite sex child of a similar age
the cope reaction or cope elimination developed by arthur c cope is an elimination reaction of the n oxide of a tertiary amine to form an alkene and a hydroxylamine the reaction mechanism involves an intramolecular 5 membered cyclic transition state leading to a syn elimination product an ei pathway this organic reaction gives the same result as the hofmann elimination but the base is a part of the leaving group the amine oxide is prepared by oxidation of the corresponding amine with an oxidant such as mcpba the actual elimination just requires heat cope reaction an application is a synthesis of methylenecyclohexane synthesis of methylenecyclohexane piperidines are resistant to an intramolecular cope reaction but with pyrrolidine and with rings of size 7 and larger the reaction product is an unsaturated hydroxyl amine this result is consistent with the 5 membered cyclic transition state intramolecular cope reaction
copigmentation is a phenomenon where pigmentation due to anthocyanidins is reinforced by the presence of other colorless flavonoids known as cofactors or “ copigments ” this occurs by the formation of a non covalently linked complex
copper free click chemistry is a bioorthogonal reaction first developed by carolyn bertozzi as an activated variant of an azide alkyne huisgen cycloaddition based on the work by fokin and sharpless et al unlike the cuaac cu free click chemistry has been modified to be bioorthogonal by eliminating a cytotoxic copper catalyst allowing reaction to proceed quickly and without live cell toxicity it was developed as a faster alternative to the staudinger ligation with the first generation producing rate constants over 63 times faster although the reaction produces a regioisomeric mixture of triazoles the lack of regioselectivity in the reaction is not a major concern for its applications in bioorthogonal chemistry more regiospecific and less bioorthogonal requirements are best served by the traditional huisgen cycloaddition especially given the low yield and synthetic difficulty compared to the addition of a terminal alkyne of synthesizing a strained cyclooctyne the incredible bioorthogonality of the reaction has allowed the cu free click reaction to be applied within cultured cells live zebrafish and mice
copper beaten skull is a phenomenon wherein intense intracranial pressure disfigures the internal surface of the skull the name comes from the fact that the inner skull has the appearance of having been beaten with a ball peen hammer such as is often used by coppersmiths the condition is most common in children
copper toxicity also called copperiedus refers to the consequences of an excess of copper in the body copperiedus can occur from eating acid foods cooked in uncoated copper cookware or from exposure to excess copper in drinking water or other environmental sources
copra itch is a skin condition that occurs on persons handling copra who are subject to tyrophagus longior mite bites
copurification in a chemical or biochemical context is the physical separation by chromatography or other purification technique of two or more substances of interest from other contaminating substances for substances to co purify usually implies that these substances attract each other to form a non covalent complex such as in a protein complex however when fractionating mixtures especially mixtures containing large numbers of components for example a cell lysate it is possible by chance that some components may copurify even though they don t form complexes in this context the term copurification is sometimes used to denote when two biochemical activities or some other property are isolated together after purification but it is not certain if the sample has been purified to homogeneity i e contains only one molecular species or one molecular complex hence these activities or properties are likely but not guaranteed to reside on the same molecule or in the same molecular complex
the term copyright abolition movements refers to movements to abolish copyright specifically those that espouse the repeal of the statute of anne and all subsequent law made in its support michele boldrin and david k levine economists at washington university have suggested that copyrights and patents are a net loss for the economy because of the way they reduce competition in the free market they refer to copyrights and patents as intellectual monopolies akin to industrial monopolies and they advocate phasing out and eventually abolishing them
cor triatriatum or triatrial heart is a congenital heart defect where the left atrium cor triatriatum sinistrum or right atrium cor triatriatum dextrum is subdivided by a thin membrane resulting in three atrial chambers hence the name cor triatriatum represents 0 1 of all congenital cardiac malformations and may be associated with other cardiac defects in as many as 50 of cases the membrane may be complete or may contain one or more fenestrations of varying size cor triatrium sinistrum is more common in this defect there is typically a proximal chamber that receives the pulmonic veins and a distal true chamber located more anteriorly where it empties into the mitral valve the membrane that separates the atrium into two parts varies significantly in size and shape it may appear similar to a diaphragm or be funnel shaped bandlike entirely intact imperforate or contain one or more openings fenestrations ranging from small restrictive type to large and widely open in the pediatric population this anomaly may be associated with major congenital cardiac lesions such as tetralogy of fallot double outlet right ventricle coarctation of the aorta partial anomalous pulmonary venous connection persistent left superior vena cava with unroofed coronary sinus ventricular septal defect atrioventricular septal endocardial cushion defect and common atrioventricular canal rarely asplenia or polysplenia has been reported in these patients in the adult cor triatriatum is frequently an isolated finding cor triatriatum dextrum is extremely rare and results from the complete persistence of the right sinus valve of the embryonic heart the membrane divides the right atrium into a proximal upper and a distal lower chamber the upper chamber receives the venous blood from both vena cavae and the lower chamber is in contact with the tricuspid valve and the right atrial appendage the natural history of this defect depends on the size of the communicating orifice between the upper and lower atrial chambers if the communicating orifice is small the patient is critically ill and may succumb at a young age usually during infancy to congestive heart failure and pulmonary edema if the connection is larger patients may present in childhood or young adulthood with a clinical picture similar to that of mitral stenosis cor triatriatum may also be an incidental finding when it is nonobstructive the disorder can be treated surgically by removing the membrane dividing the atrium
coral bleaching is the loss of intracellular endosymbionts symbiodinium also known as zooxanthellae from coral either through expulsion or loss of algal pigmentation the corals that form the structure of the great reef ecosystems of tropical seas depend upon a symbiotic relationship with algae like unicellular flagellate protozoa that are photosynthetic and live within their tissues zooxanthellae give coral its coloration with the specific color depending on the particular clade above average sea water temperatures caused by global warming have been identified as a leading cause for coral bleaching worldwide some scientists consider bleaching a poorly understood type of stress related to high irradiance environmental factors like sediments harmful chemicals and freshwater and high or low water temperatures this stress causes corals to expel their zooxanthellae which leads to a lighter or completely white appearance hence the term bleached bleaching has been attributed to a defense mechanism in corals this is called the adaptive bleaching hypothesis from a 1993 paper by robert buddemeier and daphne fautin bleached corals continue to live but the algae provide the coral with 90 of its energy after expelling the algae the coral begins to starve
coral cuts are a severe type of skin injury that may occur from the cuts of coral skeletons
coral dermatitis is a cutaneous condition caused by injury from the exoskeleton of certain corals
cord colitis syndrome is a diarrheal illness in recipients of umbilical cord blood transplant it causes a granulomatous inflammation of the upper and lower gastrointestinal tract and responds to antimicrobial treatment including metronidazole it was first described in 2011 in 2013 a sequencing study identified a newly discovered bacterium called bradyrhizobium enterica in biopsy samples from two patients that this bacterium is responsible for this syndrome can be suggested but not yet confirmed
corectopia is the displacement of the eye s pupil from its normal central position it may be associated with high myopia or ectopia lentis among other conditions medical or surgical intervention may be indicated for the treatment of corectopia in some cases
the corey – house synthesis also called the corey – posner – whitesides – house reaction and other permutations is an organic reaction that involves the reaction of a lithium dialkyl cuprate with an alkyl halide to form a new alkane an organic copper compound and a lithium halide r 2 culi r x → r r rcu lix
the corey – itsuno reduction also known as the corey – bakshi – shibata cbs reduction is a chemical reaction in which an achiral ketone is enantioselectively reduced to produce the corresponding chiral non racemic alcohol the oxazaborolidine reagent which mediates the enantioselective reduction of ketones was previously developed by the laboratory of itsuno and thus this transformation may more properly be called the itsuno corey oxazaborolidine reduction the cbs reduction in 1981 itsuno and coworkers first reported the use of chiral alkoxy amine borane complexes in reducing achiral ketones to chiral alcohols enantioselectively and in high yield several years later in 1987 e j corey and coworkers developed the reaction between chiral amino alcohols and borane bh 3 generating oxazaborolidine products which were shown to rapidly catalyze the enantioselective reduction of achiral ketones in the presence of bh 3 • thf the cbs reduction has since been utilized by organic chemists as a reliable method for the asymmetric reduction of achiral ketones notably it has found prominent use not only in a number of natural product syntheses but has been utilized on large scale in industry see scope below several reviews have been published
the corey – kim oxidation is an oxidation reaction used to synthesise aldehydes and ketones from primary and secondary alcohols it is named for american chemist and nobel laureate elias james corey and korean american chemist choung un kim the corey – kim oxidation although the corey – kim oxidation possesses the distinctive advantage over swern oxidation of allowing an operation above – 25 ° c it is not so commonly used due to issues with selectivity in substrates susceptible to chlorination by n chlorosuccinimide
in organic chemistry the corey – link reaction is a name reaction that converts a 1 1 1 tricholoro 2 keto structure into a 2 aminocarboxylic acid an alpha amino acid or other acyl functional group with control of the chirality at the alpha position the reaction is named for e j corey and john link who first reported the reaction sequence
a corn or clavus plural clavi or clavuses is a distinctively shaped callus of dead skin that usually occurs on thin or glabrous hairless and smooth skin surfaces especially on the dorsal surface of toes or fingers they can sometimes occur on the thicker palmar or plantar skin surfaces corns form when the pressure point against the skin traces an elliptical or semi elliptical path during the rubbing motion the center of which is at the point of pressure gradually widening if there is constant stimulation of the tissue producing the corns even after the corn is surgically removed the skin may continue to grow as a corn
corn maize allergy is a type of food allergy it can be a difficult allergy to manage particularly in the united states due to the high number of food products which contain various forms of corn such as corn starch modified food starch vinegar and vanilla extract among many others however it is an allergy that often goes unrecognized
grey leaf spot gls is a foliar fungal disease that affects maize also known as corn there are two fungal pathogens that cause gls which are cercospora zeae maydis and cercospora zeina symptoms seen on corn include leaf lesions discoloration chlorosis and foliar blight the fungus survives in debris of topsoil and infects healthy crop via asexual spores called conidia environmental conditions that best suit infection and growth include moist humid and warm climates poor airflow low sunlight overcrowding improper soil nutrient and irrigation management and poor soil drainage can all contribute to the propagation of the disease management techniques include crop resistance crop rotation residue management use of fungicides and weed control the purpose of disease management is to prevent the amount of secondary disease cycles as well as to protect leaf area from damage prior to grain formation corn grey leaf spot is an important disease of corn production in the united states economically significant throughout the midwest and mid atlantic regions however it is also prevalent in africa central america china europe india mexico the philippines northern south america and southeast asia the teleomorph sexual phase of cercospora zeae maydis is assumed to be mycosphaerella sp
corn smut is a plant disease caused by the pathogenic fungus ustilago maydis that causes smut on maize and teosinte the fungus forms galls on all above ground parts of corn species and is known in mexico as the delicacy huitlacoche it is eaten usually as a filling in quesadillas and other tortilla based foods and soups
cornea verticillata also called fleischer vortex vortex keratopathy or whorl keratopathy is a condition characterised by corneal deposits at the level of the basal epithelium forming a faint golden brown whorl pattern it is seen in fabry disease or in case of prolonged amiodarone intake
corneal cerebellar syndrome also known as der kaloustian jarudi khoury syndrome is an autosomally resessive disease that was first described in 1985 three cases are known all are sisters in the same family
corneal abrasion is a medical condition involving the loss of the surface epithelial layer of the eye s cornea
corneal hydrops or corneal rupture is an uncommon complication seen in people with advanced keratoconus or other corneal ectatic disorders and is characterized by stromal edema due to leakage of aqueous humor through a tear in descemet s membrane although a hydrops usually causes increased scarring of the cornea occasionally it will benefit a patient by creating a flatter cone aiding the fitting of contact lenses corneal transplantation is not usually indicated during corneal hydrops
corneal neovascularization is the excessive ingrowth of blood vessels from the limbal vascular plexus into the cornea caused by deprivation of oxygen from the air
corneal ulcer or ulcerative keratitis is an inflammatory or more seriously infective condition of the cornea involving disruption of its epithelial layer with involvement of the corneal stroma it is a common condition in humans particularly in the tropics and the agrarian societies in developing countries children afflicted by vitamin a deficiency are at high risk for corneal ulcer and may become blind in both eyes which may persist lifelong in ophthalmology a corneal ulcer usually refers to having an infectious etiology while the term corneal abrasion refers more to physical abrasions
a corneal ulcer or ulcerative keratitis is an inflammatory condition of the cornea involving loss of its outer layer it is very common in dogs and is sometimes seen in cats in veterinary medicine the term corneal ulcer is a generic name for any condition involving the loss of the outer layer of the cornea and as such is used to describe conditions with both inflammatory and traumatic causes
cornelia de lange syndrome cdls is a very rare genetic disorder present from birth but not always diagnosed at birth it causes a range of physical cognitive and medical challenges and affects both sexes equally the syndrome is named after dutch pediatrician cornelia catharina de lange who described it it is often termed bushy syndrome and is also known as amsterdam dwarfism it is a genetic disorder that can lead to severe developmental anomalies it affects the physical and intellectual development of a child exact incidence is unknown but it is estimated at 1 in 10 000 to 30 000
the cornell gorge suicides were a phenomenon of suicides at cornell university in the 1970 s the 1990 s and during the 2009 2010 school year with the suicide method being jumping from the bridges into the gorges
corneodermatosseous syndrome also known as cdo syndrome is an autosomal dominant condition with onset in infancy characterized by corneal dystrophy photophobia diffuse palmoplantar keratoderma distal onycholysis skeletal abnormalities with brachydactyly short stature and medullary narrowing of digits
a corner route is a pattern run by a receiver in american football where the receiver runs up the field and then turns at approximately a 45 degree angle heading away from the quarterback towards the sideline usually the pass is used when the defensive back is playing towards the inside shoulder of the receiver thus creating a one on one vertical matchup the corner route is less likely to be intercepted when compared to the slant route because it is thrown away from the middle of the field the pass is used frequently in the west coast offensive scheme where quick accurate throwing is key the pass may also be used closer to the goal line in what is called a fade the quarterback will lob the ball over a beaten defender to a wide receiver at the back corner of the end zone
in organic chemistry the cornforth rearrangement is a rearrangement reaction of a 4 acyloxazole in which the group attached to an acyl on position 4 and the substituent on position 5 of an oxazole ring exchange places it was first reported in 1949 and is named for john cornforth cornforth rearrangement overall reaction
the coromuel wind is a weather phenomenon unique to the la paz area of the baja california peninsula and adjoining gulf of california occurring primarily in the late spring and summer it is a south to south west wind that typically starts late in the afternoon or early evening and blows throughout the night into the mid morning it has a rapid onset and can be very strong especially in the bay of la paz the basic mechanism of the coromuel winds is fairly clear the winds are created when the cool marine air from the pacific side of the peninsula are drawn over the desert to the relatively warmer side of the gulf of california it only occurs in the la paz area because this is the only place on the peninsula that does not have a spine of mountains blocking such an air flow the winds receive their name after samuel cromwell a sailor from the 19 th century believed to be a pirate he visited la paz often and according to legend hid one of his biggest treasures on the beach that carries his name since natives could not pronounce his surname they called him coromuel
coronal rain is a phenomenon that occurs in the sun s corona it occurs when hot plasma in the corona cools and condenses in strong magnetic fields usually associated with regions that produce solar flares the plasma is attracted to the magnetic fields where it condenses and slowly falls back to the solar surface
coronary artery aneurysm is an abnormal dilatation of part of the coronary artery
coronary artery anomalies or malformation of coronary vessels are congenital abnormalities in the coronary anatomy of the heart by definition these abnormalities are variants of anatomy occurring in less than 1 of the general population they are often found in combination with other congenital heart defects many coronary anomalies don t cause symptoms and are recognized only at the time of autopsy they can be associated with sudden death the real risk of death or the best way to treat these patients is not yet known the congenital heart surgeons society has started a long term ongoing study called anomalous aortic origin of a coronary artery aaoca to identify the best way to treat this defect
coronary artery disease cad also known as ischemic heart disease ihd is a group of diseases that includes stable angina unstable angina myocardial infarction and sudden cardiac death it is within the group of cardiovascular diseases of which it is the most common type a common symptom is chest pain or discomfort which may travel into the shoulder arm back neck or jaw occasionally it may feel like heartburn usually symptoms occur with exercise or emotional stress last less than a few minutes and get better with rest shortness of breath may also occur and sometimes no symptoms are present the first sign is occasionally a heart attack other complications include heart failure or an irregular heartbeat risk factors include high blood pressure smoking diabetes lack of exercise obesity high blood cholesterol poor diet and excessive alcohol among others other risks include depression the underlying mechanism involves atherosclerosis of the arteries of the heart a number of tests may help with diagnoses including electrocardiogram cardiac stress testing coronary computed tomographic angiography and coronary angiogram among others prevention is by eating a healthy diet regular exercise maintaining a healthy weight and not smoking sometimes medication for diabetes high cholesterol or high blood pressure are also used there is limited evidence for screening people who are at low risk and do not have symptoms treatment involves the same measures as prevention additional medications such as antiplatelets including aspirin beta blockers or nitroglycerin may be recommended procedures such as percutaneous coronary intervention pci or coronary artery bypass surgery cabg may be used in severe disease in those with stable cad it is unclear if pci or cabg in addition to the other treatments improve life expectancy or decreases heart attack risk in 2013 cad was the most common cause of death globally resulting in 8 14 million deaths 16 8 up from 5 74 million deaths 12 in 1990 the risk of death from cad for a given age has decreased between 1980 and 2010 especially in developed countries the number of cases of cad for a given age has also decreased between 1990 and 2010 in the united states in 2010 about 20 of those over 65 had cad while it was present in 7 of those 45 to 64 and 1 3 of those 18 to 45 rates are higher among men than women of a given age
a coronary artery dissection also known as spontaneous coronary artery dissection or scad is a rare sometimes fatal traumatic condition with eighty percent of cases affecting women the coronary artery develops a tear causing blood to flow between the layers which forces them apart early studies of the disease placed mortality rates at around 70 but more recent data indicate this figure may be closer to 18
coronary artery ectasia is a rare disease that occurs in only 0 3 4 9 of people in north america coronary artery ectasia is characterized by the enlargement of a coronary artery to 1 5 times or more than its normal diameter the disease is commonly asymptomatic and is normally discovered when performing tests for other conditions such as coronary artery disease stable angina and other acute coronary syndromes coronary artery ectasia occurs 4 times more frequently in males than in females and in people who have risk factors for heart disease such as smokers while the disease is commonly found in patients with atherosclerosis and coronary artery disease it can occur by itself and in both cases it can cause health problems the disease can cause the heart tissue to be deprived of blood and die due to decreased blood flow and blockages due to blood clots or spasms of the blood vessel this blood flow disruption can cause permanent damage to the muscle if the deprivation is prolonged coronary artery ectasia also increases the chance of developing large weak spots in the affected coronary arteries or aneurysms that can rupture and result in death the damage can result in angina which is pain in the chest and is a common complaint in these patients
coronary flow reserve cfr is the maximum increase in blood flow through the coronary arteries above the normal resting volume its measurement is often used in medicine to assist in the treatment of conditions affecting the coronary arteries and to determine the efficacy of treatments used
a coronary occlusion is the partial or complete obstruction of blood flow in a coronary artery this condition may cause a heart attack in some patients coronary occlusion causes only mild pain tightness or vague discomfort which may be ignored the myocardium is however damaged according to the nicholas and alexandra book tsar nicholas ii of russia suffered a coronary occlusion right before he was toppled from his throne during the russian revolution in 1917
coronary steal with its symptoms termed coronary steal syndrome or cardiac steal syndrome is a phenomenon where an alteration of circulation patterns lead to a reduction in the blood directed to the coronary circulation it is caused when there is narrowing of the coronary arteries and a coronary vasodilator is used – stealing blood away from those parts of the heart this happens as a result of the narrowed coronary arteries being always maximally dilated to compensate for the decreased upstream blood supply thus dilating the resistance vessels in the coronary circulation causes blood to be shunted away from the coronary vessels supplying the ischemic zones creating more ischemia
coronary thrombosis is the formation of a blood clot inside a blood vessel of the heart this blood clot restricts blood flow within the heart it is associated with narrowing of blood vessels subsequent to clotting the condition is considered as a type of ischaemic heart disease thrombosis in the heart can lead to a myocardial infarction coronary thrombosis and myocardial infarction are sometimes used as synonyms although this is technically inaccurate as the thrombosis refers to the blocking of blood vessels while the infarction refers to the tissue death due to the consequent loss of blood flow to the heart tissue the heart contains many connecting blood vessels and depending upon the location of the thrombosis the infarction may cause no symptoms coronary thrombosis can be a complication associated with drug eluting stents
corporate foresight is an ability that includes any structural or cultural element that enables the company to detect discontinuous change early interpret the consequences for the company and formulate effective responses to ensure the long term survival and success of the company
corporate travel management ctm is the function of managing a company ’ s strategic approach to travel travel policy the negotiations with all vendors day to day operation of the corporate travel program traveler safety and security credit card management and travel and expenses t e data management ctm should not be confused with the work of a traditional travel agency while agencies provide the day to day travel services to corporate clients they are the implementing arm of what the corporation has negotiated and put forth in policy in other words ctm decides on the class of service which employees are allowed to fly negotiates corporate fares rates with airlines and hotels and determines how corporate credit cards are to be used the agency on the other hand makes the actual reservation within the parameters given by the corporation for many companies t e costs represent the second highest controllable annual expense exceeded only by salary and benefits and is commonly higher than it or real estate costs t e costs are not only limited to travel airline rail hotel car rental ferry boat etc but include all costs incurred during travel such as staff and client meals taxi fares gratuities client gifts supplies office supplies and services etc furthermore this area often includes meeting management traveler safety and security as well as credit card and overall travel data management the management of these costs are usually handled by the corporate travel manager a function which may be part of the finance hr procurement or administrative services department
a corpus luteum cyst is a type of ovarian cyst which may rupture about the time of menstruation and take up to three months to disappear entirely a corpus luteum cyst rarely occurs at age 50 because eggs are no longer being produced in menopausal women corpus luteum cysts may contain blood and other fluids the physical shape of a corpus luteum cyst may appear as an enlargement of the ovary itself rather than a distinct mass like growth on the surface of the ovary
clustering is the problem of partitioning data points into groups based on their similarity correlation clustering provides a method for clustering a set of objects into the optimum number of clusters without specifying that number in advance
in latin and greek poetry correption kərˈrɛpʃən latin correptiō korˈreptɪoː a shortening is the shortening of a long vowel at the end of one word before a short vowel at the beginning of the next vowels next to each other in neighboring words are in hiatus homer uses correption in dactylic hexameter ἄνδρα μοι ἔννεπε μοῦσα πολύτροπον ὃς μάλα πολλὰπλάγχθη ἐπεὶ τροίης ἱερὸν πτολίεθρον ἔπερσε · — odyssey 1 2 tell me o muse of the man of many devices who wandered fullmany ways after he had sacked the sacred citadel of troy — translation by a t murray here the sequence η ε in bold must be pronounced as ε ε to preserve the long — short — short syllable weight sequence of a dactyl thus the scansion of the second line is thus πλαγχ θε ε πει τροι ης ι ε ρον πτο λι εθ ρο νε περ σε
corrosion fatigue is fatigue in a corrosive environment it is the mechanical degradation of a material under the joint action of corrosion and cyclic loading nearly all engineering structures experience some form of alternating stress and are exposed to harmful environments during their service life the environment plays a significant role in the fatigue of high strength structural materials like steel aluminum alloys and titanium alloys materials with high specific strength are being developed to meet the requirements of advancing technology however their usefulness depends to a large extent on the degree to which they resist corrosion fatigue the effects of corrosive environments on the fatigue behavior of metals were studied as early as 1930 the phenomenon should not be confused with stress corrosion cracking where corrosion such as pitting leads to the development of brittle cracks growth and failure the only requirement for corrosion fatigue is that the sample be under tensile stress
corruption in afghanistan is a widespread and growing problem in afghan society afghanistan ranks 174 of 176 in transparency international s 2012 corruption perceptions index and is routinely named as one of the world s five most corrupt countries north korea and somalia were ranked as equally corrupt in opinion surveys of afghans noted the asia foundation in a 2012 report corruption is consistently singled out as a problem one of the recent major corruption cases was the 2010 – 13 kabul bank financial scandal involving mahmood karzai and others close to president hamid karzai the kabul bank scandal crisis investigation and trial involved sherkhan farnood khalilullah fruzi mohammed fahim and other insiders who were allegedly spending the bank s us 1 billion for their personal lavish living style as well as lending money under the table to family friends and those close to president hamid karzai and mahmood karzai as of october 2012 the government only recovered 180 million of the 980 million fraudulent loans a u n survey listed corruption and insecurity as the two issues of greatest concern to afghans as of 2012 the new york times has written that in afghanistan corruption can no longer be described as a cancer on the system it is the system the u s agency for international development stated in 2009 that corruption in afghanistan had become pervasive entrenched systemic and by all accounts now unprecedented in scale and reach in a 2011 survey by the asia foundation afghans said corruption was their third biggest problem 21 after insecurity 35 and unemployment 23 in 2010 and 2011 they said corruption was their second most important reason for feeling pessimistic about afghanistan 16 in 2011 and 27 in 2010 in 2011 they identified administrative corruption as the government s second most important failure 25 this marked an improvement over 2010 when the figure was 30 in afghanistan today corruption most often takes the form of demanding and offering bribes both in the private and public sectors and on large and small scales there are also many other major forms of corruption including nepotism graft and illegal land transfers the us special inspector general for afghan reconstruction sigar has estimated that over half of the nation s annual customs revenue is lost to graft in a 2015 article parag r dharmavarapu noted that while afghanistan ’ s gdp had quintupled since 2002 the society remained riddled with corruption what is extremely disconcerting about corruption in afghanistan wrote dharmavarapu is not simply the number or value of bribes that take place instead it is the endemic nature of corruption within the afghan government routinely noted dharmavarapu police officers extort goods from shopkeepers levy taxes on vehicles at highway checkpoints and impose fines on individuals unable to produce proper identification documents some police officers turn a blind eye to or even collude with criminals and insurgents while mid to high level police officials collaborate with criminals in smuggling kidnapping for ransom and other illegal activities collecting thousands of dollars in the process top police officials have siphoned millions of dollars from international donors to their own pockets the most common types of corruption in afghanistan according to dharmavarapu are petty bribery – asking for small gifts baksheesh in exchange for special treatment or favors position buying – awarding opportunities in the police force judiciary or civil service based on bribes as opposed to merit nepotism clientelism – awarding positions based on personal relationship kinship networks rather than merit offering and asking for preferential treatment – this includes giving bribes to expedite the processing of business documents or access to government owned land grand corruption – corruption that involves political elites on a large scale national police and law enforcement graft according to the high office of oversight and anti corruption hooac corruption is rampant in the north of the country particularly balkh province which borders neighboring uzbekistan a country with similar corruption problems one of the worst manifestations of graft is illegal land grabbing shamsullah javed hooac head for the northern zone in an exclusive interview with pajhwok afghan news explained that in balkh there are three kinds of encroachment on land one government department seizing the property of another security forces occupying government land and individuals taking unlawful possession of people s land he revealed that 52 out of 60 housing schemes in balkh were executed illegally government servants from top to bottom are involved in the scourge some people whose interests are hurt by investigations into corruption cases are creating problems for us javed said investigative journalist sibel edmonds has undertaken efforts as a journalist and whistleblower to raise awareness about corruption in afghanistan and waste fraud and abuse involving billions of dollars of u s taxpayers money lost to corruption and corrupt officials in afghanistan following the u s intervention the great challenge to afghanistan s future isn t the taliban or the pakistani safe havens or even an incipiently hostile pakistan gen john r allen told a u s senate foreign relations subcommittee in 2014 the existential threat to the long term viability of modern afghanistan is corruption he stated that the insurgency criminal patronage networks and drug traffickers had formed an unholy alliance
corruption in albania is a serious problem albania ranked 113 th of 176 countries in the 2012 corruption perceptions index tied with ethiopia guatemala niger and timor leste published by transparency international corruption is still considered one of the most problematic factors for establishing business in albania
corruption in angola is a pervasive phenomenon hindering economic growth and government sponsored liberalization programs
political corruption in armenia is a widespread and growing problem in armenian society
corruption in brazil is a pervasive social problem in the 2015 corruption perceptions index brazil tied with bosnia and herzegovina burkina faso india thailand tunisia and zambia ranking 76 th among 168 countries corruption was cited among many issues that provoked the 2013 protests in brazil
corruption in colombia is a pervasive problem at all levels of government colombia currently ranks 83 rd of 168 in the corruption perceptions index of 2015 tied with benin china liberia and sri lanka different factors have contributed to political corruption in colombia including drug trafficking guerrilla and paramilitary conflict weak surveillance and regulation from institutions threats and harassment to whistle blowers and a widespread apathy from society to address unethical behavior
corruption in haiti is a serious problem in 2015 haiti ranked 161 out of the 177 countries measured on transparency international s corruption perception index the lowest ranking in the caribbean region on the corruption perception index haiti ranked 163 in 2014 and 164 in 2013 corruption is a severe and widespread problem in all levels of government although there has been some progress since 2008 when haiti was rated the world s fourth most corrupt country there remains much room for improvement corruption in haiti according to the heritage foundation s 2015 index of economic freedom inundates all parts of haitian society robert klitgaard an expert on the subject wrote in 2010 that corruption in haiti is not the activity of a few rogue officials or politicians but is more like organized crime with corrupt procurement deals arising through collusion and kleptocratic racket in a january 2012 article peter worthington stated that haiti s dependency on foreign aid and corrupt legacy have hurt the nation s development more that the growing trend of educated haitians emigrating between 1984 and 2009 foreigners contributed over 2 6 billion to relieve poverty in haiti but thanks largely to corruption their efforts had little impact several journalists investigating corruption in haiti have been killed or fled into exile
extensive corruption among kuwait s high level government officials is a problem resulting in political tensions between the government and the public
corruption in mauritius is a widespread and growing problem in cables leaked from the us embassy the problem with corruption was referred to as pervasive and ingrained the independent commission against corruption icac investigates offenses and can confiscate the proceeds of corruption and money laundering in 2008 the director of the mauritius customs service stated that stated that during a meeting on april 11 2008 with government officials including the financial secretary of the ministry of finance and economic development and deputy commissioner of police he was told in no uncertain terms that he should remain quiet about the alleged corruption because if it were to become public it could bring down the current government of mauritius in 2013 dutch dredging group boskalis has been fined the equivalent of € 1000 by a court in mauritius for making illicit payments to a port official in february 2016 the outgoing united states ambassador to mauritius stated that there is so much turmoil at the independent commission against corruption that it has lost its credibility in april 2016 the independent commission against corruption opened an investigation in the recruitment of the director of the independent broadcasting authority mauritius in april 2016 the independent commission against corruption recommended formal proceedings against the former minister of the environment in may 2016 the representative of cisco system filed suit against the national computer board and executives of the mauritius qualifications authority it was alleged that a bribe is required for all government projects
political corruption is a persistent phenomenon in nigeria president muhammadu buhari defined corruption as the greatest form of human right violation since the creation of modern public administration in the country there have been cases of official misuse of funds and resources the rise of public administration and the discovery of oil and natural gas are two major events seen to have led to the increase in corrupt practices in the country the government has tried to contain corruption through the enactment of laws and the enforcement of integrity systems but success has been slow in coming in 2012 nigeria was estimated to have lost over 400 billion to corruption since independence
corruption in north korea is a widespread and growing problem in north korean society north korea is ranked 175 out of 177 countries in transparency international s 2013 corruption perceptions index tied with somalia and afghanistan strict rules and draconian punishments imposed by the regime for example against accessing foreign media or for modifying radio or television receivers to access foreign media are commonly evaded by offering bribes to the police informing on colleagues and family members has become less common main article north korea north korea ’ s state media admitted widespread corruption in north korea when laying out the accusations against jang sung taek after his execution in december 2013 the statement mentions bribery deviation of materials selling resources and land securing funds and squandering money for private use by organizations under his control
both grand and petty corruption are serious problems in tanzania yet various comprehensive laws are in place to prevent corruption it is largely due to a weak internal control and low or non compliance with anti corruption regulations within different government agencies for instance public procurement taxation and customs service are areas that are prone to corruption foreign companies have identified that corruption within those sectors poses potential obstacles for doing business in tanzania as bribery is often demanded it is also believed that the existing large informal sector amount 48 1 of gdp is associated with cumbersome business registration process which have created opportunities for corruption
corruption is a widespread and growing problem in ukrainian society in 2015 s transparency international corruption perceptions index ukraine was ranked 130 th out of the 167 countries investigated tied with paraguay and the comoros back in 2007 ukraine had taken 118 th place 179 countries investigated that year ernst young in 2012 put ukraine among the three most corrupted nations of the world together with colombia and brazil united states diplomats have described ukraine under presidents kuchma and yushchenko as a kleptocracy according to wikileaks cables
corruption in uzbekistan is a serious problem there are laws in place to prevent corruption but the enforcement is very weak low prosecution rates of corrupt officials is another contributing factor to the rampant corruption in uzbekistan it is not a criminal offense for a non public official to influence the discretion of a public official the judicial system faces severe functional deficits due to limited resources and corruption in uzbekistan corruption is present at virtually every level of society business and government it is also one of the world s most corrupt countries and among the contributory factors is its possessing the second largest economy in central asia its large reserves of natural gas and its geographical position between the rival powers of the so called cold war ii on transparency international s 2013 corruption perceptions index uzbekistan stood at 168 th place out of 177 countries and territories surveyed and 166 th out of 174 on the 2014 index “ graft and bribery among low and mid level officials are part of everyday life and are sometimes even transparent ” states freedom house which adds that the ubiquity of corruption helps to “ limit equality of opportunity ” a 2015 report by amnesty international quotes a businessman who was arrested and tortured in 2011 as saying that corruption in uzbekistan is a “ cancer that had spread everywhere ”
cortical blindness is the total or partial loss of vision in a normal appearing eye caused by damage to the brain s occipital cortex cortical blindness can be acquired or congenital and may also be transient in certain instances acquired cortical blindness is most often caused by loss of blood flow to the occipital cortex from either unilateral or bilateral posterior cerebral artery blockage ischemic stroke and by cardiac surgery in most cases the complete loss of vision is not permanent and the patient may recover some of their vision cortical visual impairment congenital cortical blindness is most often caused by perinatal ischemic stroke encephalitis and meningitis rarely a patient with acquired cortical blindness may have little or no insight that they have lost vision a phenomenon known as anton – babinski syndrome cortical blindness and cortical visual impairment cvi which refers to the partial loss of vision caused by cortical damage are both classified as subsets of neurological visual impairment nvi nvi and its three subtypes — cortical blindness cortical visual impairment and delayed visual maturation — must be distinguished from ocular visual impairment in terms of their different etiologies and structural foci the brain and the eye respectively one diagnostic marker of this distinction is that the pupils of individuals with cortical blindness will respond to light whereas those of individuals with ocular visual impairment will not
cortical deafness is a rare form of sensorineural hearing loss caused by damage to the primary auditory cortex cortical deafness is an auditory disorder where the patient is unable to hear sounds but has no apparent damage to the anatomy of the human ear see auditory system which can be thought of as the combination of auditory verbal agnosia and auditory agnosia patients with cortical deafness cannot hear any sounds that is they are not aware of sounds including non speech voices and speech sounds although patients appear and feel completely deaf they can still exhibit some reflex responses such as turning their head towards a loud sound cortical deafness is caused by bilateral cortical lesions in the primary auditory cortex located in the temporal lobes of the brain the ascending auditory pathways are damaged causing a loss of perception of sound inner ear functions however remains intact cortical deafness is most often cause by stroke but can also result from brain injury or birth defects more specifically a common cause is bilateral embolic stroke to the area of heschl s gyri cortical deafness is extremely rare with only twelve reported cases each case has a distinct context and different rates of recovery it is thought that cortical deafness could be a part of a spectrum of an overall cortical hearing disorder in some cases patients with cortical deafness have had recovery of some hearing function resulting in partial auditory deficits such as auditory verbal agnosia this syndrome might be difficult to distinguish from a bilateral temporal lesion such as described above
cortical desmoid also called tug lesion or periosteal desmoid is an irregularity of the distal femoral cortex caused by repetitive stress at the attachment of the adductor magnus aponeurosis it is most commonly seen in adolescents and is usually asymptomatic it is a benign and self limiting lesion
focal cortical dysplasia fcd is a congenital abnormality of brain development where the neurons in an area of the brain failed to migrate in the proper formation in utero focal cortical dysplasia is a common cause of intractable epilepsy in children and is a frequent cause of epilepsy in adults there are several subtypes of fcd including type 1 a 1 b 2 a 2 b 3 a 3 b and 3 c each with distinct histopathological features all forms of focal cortical dysplasia lead to disorganization of the normal structure of the cerebral cortex type 1 fcd exhibits subtle alterations in cortical lamination type 2 a fcd exhibits neurons that are larger than normal that are called cytomegalic dysmorphic neurons cdn fcd type 2 b exhibits complete loss of laminar structure and the presence of cdn and enlarged cells are called balloon cells bc for their large elliptical cell body shape laterally displaced nucleus and lack of dendrites or axons the developmental origin of balloon cells is currently believed to be derived from neuronal or glial progenitor cells balloon cells are similar in structure to giant cells in the disorder tuberous sclerosis complex recent studies have demonstrated that fcd types 2 a and 2 b result from somatic mutations in genes that encode components of the mammalian target of rapamycin mtor pathway causative gene mutations for types 1 and 3 have not been identified the mtor pathway regulates a number of functions in the brain including establishment of cell size cell motility and differentiation gene mutations associated with fcd 2 a and fcd 2 b include mtor pi 3 kca akt 3 and depdc 5 mutations in these genes lead to enhanced mtor pathway signaling at critical periods in brain development some recent evidence may suggest a role for in utero infection with certain viruses such as cytomegalovirus and human papilloma virus seizures in fcd are likely causes by abnormal circuitry induced by the presence of cdns and bcs these abnormal cell types generate abnormal electrical signals which spread out to affect other parts of the cerebral cortex medication is used to treat the seizures that may arise due to cortical dysplasia epilepsy surgery to remove areas of fcd is a viable treatment option for appropriate candidates
corticobasal degeneration cbd or corticobasal ganglionic degeneration cbgd is a rare progressive neurodegenerative disease involving the cerebral cortex and the basal ganglia cbd symptoms typically begin in people from 50 – 70 years of age and the average disease duration is six years it is characterized by marked disorders in movement and cognitive dysfunction and is classified as one of the parkinson plus syndromes clinical diagnosis is difficult as symptoms of cbd are often similar to those of other disorders such as parkinson s disease pd progressive supranuclear palsy psp and dementia with lewy bodies dlb due to the various clinical presentations associated with cbd a final diagnosis can only be made upon neuropathologic examination patients who are suffering from this disorder can learn more about cbd and reach out to others with the same condition for support through the foundation for psp cbd and related brain diseases also known as curepsp
the cortisol awakening response car is an increase of about 50 in cortisol levels occurring 20 – 30 minutes after awakening in the morning in some people this rise is superimposed upon the late night rise in cortisol which occurs before awakening while its purpose is uncertain it may be linked to the hippocampus preparation of the hypothalamic pituitary adrenal axis hpa in order to face anticipated stress
in mathematics coset enumeration is the problem of counting the cosets of a subgroup h of a group g given in terms of a presentation as a by product one obtains a permutation representation for g on the cosets of h if h has a known finite order coset enumeration gives the order of g as well for small groups it is sometimes possible to perform a coset enumeration by hand however for large groups it is time consuming and error prone so it is usually carried out by computer coset enumeration is usually considered to be one of the fundamental problems in computational group theory the original algorithm for coset enumeration was invented by john arthur todd and h s m coxeter various improvements to the original todd – coxeter algorithm have been suggested notably the classical strategies of v felsch and hlt haselgrove leech and trotter a practical implementation of these strategies with refinements is available at the ace website the knuth – bendix algorithm also can perform coset enumeration and unlike the todd – coxeter algorithm it can sometimes solve the word problem for infinite groups the main practical difficulties in producing a coset enumerator are that it is difficult or impossible to predict how much memory or time will be needed to complete the process if a group is finite then its coset enumeration must terminate eventually although it may take arbitrarily long and use an arbitrary amount of memory even if the group is trivial depending on the algorithm used it may happen that making small changes to the presentation that do not change the group nevertheless have a large impact on the amount of time or memory needed to complete the enumeration these behaviours are a consequence of the unsolvability of the word problem for groups a gentle introduction to coset enumeration is given in rotman s text on group theory more detailed information on correctness efficiency and practical implementation can be found in the books by sims and holt et al
the cosmic age problem is a historical problem in astronomy concerning the age of the universe the problem was that at various times in the 20 th century some objects in the universe were estimated to be older than the time elapsed since the big bang as estimated from measurements of the expansion rate of the universe known as the hubble constant denoted h 0 this is more correctly called the hubble parameter since it generally varies with time since around 1997 – 2003 the problem is believed to be solved by most cosmologists modern measurements give an accurate age of the universe of 13 8 billion years and recent age estimates for the oldest objects are either younger than this or consistent allowing for measurement uncertainties
a cosmology episode is a sudden loss of meaning followed eventually by a transformative pivot which creates the conditions for revised meaning in the wake of the 1962 cuban missile crisis the vietnam war the 1977 tenerife airport disaster the 1984 bhopal chemical disaster and the relatively sudden insertion of personal computers into the workplace organizational scholar karl e weick coined the term cosmology episode as follows in 1985 representations of events normally hang together sensibly within the set of assumptions that give them life and constitute a cosmos rather than its opposite a chaos sudden losses of meaning that can occur when an event is represented electronically in an incomplete cryptic form are what i call a cosmology episode representations in the electronic world can become chaotic for at least two reasons the data in these representations are flawed and the people who manage those flawed data have limited processing capacity these two problems interact in a potentially deadly vicious circle the concept of cosmology episodes evolved significantly between 1985 and 1993 when weick published his now classic reanalysis of norman maclean s study of the mann gulch wildland firefighting disaster in 1949 in the 1993 article weick positions cosmology episodes within a constructivist ontology he links the term to a variety of similar concepts and he provides a better developed definition than he was able to provide in 1985 first weick makes it clear that cosmology episodes occur within a constructivist ontology of the world rather than the more familiar objectivist and subjectivist ontologies the basic idea of sensemaking is that reality is an ongoing accomplishment that emerges from efforts to create order and make retrospective sense of what occurs sensemaking emphasizes that people try to make things rationally accountable to themselves and others thus in the words of morgan frost and pondy 1983 24 individuals are not seen as living in and acting out their lives in relations to a wider reality so much as creating and sustaining images of a wider reality in part to rationalize what they are doing they realize their reality by reading into their situation patterns of significant meaning second weick clarifies the key phrase sudden loss of meaning by linking it to related ideas described by other organizational scholars minimal organizations such as we find in the crew at mann gulch are susceptible to sudden losses of meaning which have been variably described as fundamental surprises reason 1990 or as events that are inconceivable lanir 1989 hidden westrum 1982 or incomprehensible perrow 1984 each of these labels points to the low probability that the event could occur which is why it is meaningless but these explanations say less about the astonishment of the perceiver and even less about the perceiver s inability to rebuild some sense of what is happening third weick expands his 1985 definition sudden losses of meaning — to a more nuanced description cosmology refers to a branch of philosophy often subsumed under metaphysics that combines rational speculation and scientific evidence to understand the universe as a totality of phenomena cosmology is the ultimate macro perspective directed at issues of time space change and contingency as they relate to the origin and structure of the universe integrations of these issues however are not just the handiwork of philosophers others also must make their peace with these issues as reflected in what they take for granted people including those who are smokejumpers act as if events cohere in time and space and that change unfolds in an orderly manner these everyday cosmologies are subject to disruption and when they are severely disrupted i call this a cosmology episode weick 1985 51 52 a cosmology episode occurs when people suddenly and deeply feel that the universe is no longer a rational orderly system
cost of goods available for sale is the maximum amount of goods or inventory that a company can possibly sell during this fiscal year it has the formula beginning inventory at the start of this year purchases within this year production within this year cost of goods available for sale notice that purchases and production might not be the same throughout the year since purchase cost and production cost might vary during the year but at the end the total cost of purchases and production are added to beginning inventory cost to give cost of goods available for sale alternatively the costs of goods available for sales can be computed from the costs of sales costs of goods available for sale ending inventory inventory write downs costs of sales
costello syndrome also called faciocutaneoskeletal syndrome or fcs syndrome is a rare genetic disorder that affects many parts of the body it is characterized by delayed development and delayed mental progression distinctive facial features unusually flexible joints and loose folds of extra skin especially on the hands and feet heart abnormalities are common including a very fast heartbeat tachycardia structural heart defects and overgrowth of the heart muscle hypertrophic cardiomyopathy infants with costello syndrome may be large at birth but grow more slowly than other children and have difficulty feeding later in life people with this condition have relatively short stature and many have reduced levels of growth hormones it is a rasopathy beginning in early childhood people with costello syndrome have an increased risk of developing certain cancerous and noncancerous tumors small growths called papillomas are the most common noncancerous tumors seen with this condition they usually develop around the nose and mouth or near the anus the most frequent cancerous tumor associated with costello syndrome is a soft tissue tumor called a rhabdomyosarcoma other cancers also have been reported in children and adolescents with this disorder including a tumor that arises in developing nerve cells neuroblastoma and a form of bladder cancer transitional cell carcinoma costello syndrome was discovered by dr jack costello a new zealand paediatrician in 1977 he is credited with first reporting the syndrome in the australian paediatric journal volume 13 no 2 in 1977
costochondritis also known as chest wall pain costosternal syndrome or costosternal chondrodynia is an acute and often temporary inflammation of the costal cartilage the structure that connects each rib to the sternum at the costosternal joint the condition is a common cause of chest pain though costochondritis often resolves on its own it can be a recurring condition that has little or no signs of onset costochondritis symptoms can be similar to the chest pain associated with a heart attack unexplained chest pain is considered a medical emergency until life threatening cardiac issues can be ruled out severe cases of costal cartilage inflammation that also involve painful swelling are sometimes referred to as tietze s syndrome a term sometimes used interchangeably with costochondritis however some physicians view costochondritis and tietze s syndrome as separate disease states due to the absence of costal cartilage swelling in costochondritis treatment options are quite limited and usually involve a combination of rest analgesics or anti inflammatory medications cases with persistent discomfort may be managed with cortisone injections or surgery may be indicated if the condition is severe individuals with costochondritis are typically instructed to avoid strenuous physical activity to prevent the onset of an attack
cotard delusion is a rare mental illness in which the affected person holds the delusional belief that he or she is already dead does not exist is putrefying or has lost his or her blood or internal organs statistical analysis of a hundred patient cohort indicates that the denial of self existence is a symptom present in 69 of the cases of cotard s syndrome yet paradoxically 55 of the patients present delusions of immortality in 1880 the neurologist jules cotard described the condition as le délire des négations the delirium of negation a psychiatric syndrome of varied severity a mild case is characterized by despair and self loathing while a severe case is characterized by intense delusions of negation and chronic psychiatric depression the case of mademoiselle x describes a woman who denied the existence of parts of her body and of her need to eat she said that she was condemned to eternal damnation and therefore could not die a natural death in the course of suffering the delirium of negation mademoiselle x died of starvation the cotard delusion is not included in the diagnostic and statistical manual of mental disorders dsm in the tenth edition of the international statistical classification of diseases and related health problems icd 10 of the world health organization code f 22 identifies the cotard delusion as a disease of human health
cotton fever is a condition that is often associated with intravenous drug use specifically with the use of cotton to filter drugs like heroin it has been established that the condition derives from an endotoxin released by the bacteria pantoea agglomerans which colonizes cotton plants not from the cotton itself a condition very similar to cotton fever was described in the early 1940 s among cotton farm workers the term cotton fever was coined in 1975 after the syndrome was recognized in intravenous drug users however some sources have attributed the symptoms of cotton fever with sepsis occasioned by unsafe and unsanitary drug injection practices this is borne out by the fact that cotton fever symptoms have occurred among all intravenous drug users with various filter materials utilized
cotton wool spots are an abnormal finding on funduscopic exam of the retina of the eye they appear as fluffy white patches on the retina they are caused by damage to nerve fibers and are a result of accumulations of axoplasmic material within the nerve fiber layer there is reduced axonal transport and hence backlog and accumulation of intracellular products within the nerves because of the ischemia this then causes the nerve fibers to be damaged by swelling in the surface layer of the retina a 1981 analysis concluded that in most instances cotton wool spots do not represent the whole area of ischaemic inner retina but merely reflect the obstruction of axoplasmic flow in axons crossing into much larger ischaemic areas associated findings include microvascular infarcts and hemorrhages the appearance of cotton wool spots may decrease over time abundant cotton wool spots are seen in malignant hypertension diabetes and hypertension are the two most common diseases that cause these spots and the best treatment would be to treat the underlying disease in diabetes they are one of the hallmarks of pre proliferative retinopathy more rarely hiv and purtscher s retinopathy can also lead to the appearance of cotton wool spots another condition in which cotton wool spots are found is central retinal vein occlusion
coturnism is an illness featuring muscle tenderness and rhabdomyolysis muscle cell breakdown after consuming quail usually common quail coturnix coturnix from which the name derives that have fed on poisonous plants
in computer science the count distinct problem also known in applied mathematics as the cardinality estimation problem is the problem of finding the number of distinct elements in a data stream with repeated elements this is a well known problem with numerous applications the elements might represent ip addresses of packets passing through a router unique visitors to a web site elements in a large database motifs in a dna sequence or elements of rfid sensor networks
the counter majoritarian difficulty sometimes counter majoritarian dilemma is a perceived problem with judicial review of legislative or popularly created laws as the term suggests some oppose or see a problem with the judicial branch s ability to invalidate overrule or countermand laws that reflect the will of the majority the counter majoritarian difficulty is often raised in discussions of united states constitutional law particularly in discussing the powers of the three branches of the federal government of the united states
in quantum mechanics counterfactual definiteness cfd is the ability to speak meaningfully of the definiteness of the results of measurements that have not been performed i e the ability to assume the existence of objects and properties of objects even when they have not been measured the term counterfactual definiteness is used in discussions of physics calculations especially those related to the phenomenon called quantum entanglement and those related to the bell inequalities the single adjective counterfactual may also appear in physics discussions where it is frequently treated as a noun the word counterfactual does not mean characterized by being opposed to fact instead it is used to characterize values that could have been measured but for one reason or another were not
the country of origin effect coe also known as the made in image and the nationality bias is a psychological effect describing how consumers attitudes perceptions and purchasing decisions are influenced by products country of origin labeling since 1965 it has been extensively studied by researchers
country changing is a phenomenon in the figure skating world in which skaters change the country they represent in competition there are many different reasons why competitors switch countries but it mostly comes down to maximizing the possibility of being able to compete at the world figure skating championships and the winter olympic games a skater who cannot do that representing their home country often looks for another one because spots to worlds and the olympics are allotted by country not by skater a skater can hope to transfer to a new country and have a better chance of becoming national champion being sent to worlds and qualifying for a spot in the olympics
a county seat war is an american phenomenon that occurred mainly in the old west as it was being settled although similar incidents elsewhere such as in southeastern ohio have also been recorded as new towns sprang up and county lines were drawn there was intense competition for the status and tax benefits bestowed by becoming a county seat these wars often involved nothing more than lining up at the ballot box but sometimes partisans for a particular town would resort to voter fraud intimidation or violence
a coup d état ˌkuː deɪˈtɑː french ku deta sometimes translated as blow of state or hit of state but the literal translation is stroke of the state – as in the swiping or stroke of a sword plural coups d état pronounced like the singular form also known simply as a coup ˌkuː putsch or an overthrow is the illegal and overt seizure of a state by the military or other elites within the state apparatus
the coup of 18 fructidor year v was a seizure of power by members of the french directory on 4 september 1797 when their opponents the royalists were gaining strength howard g brown professor of history at binghamton university stresses the turn toward dictatorship and the failure of liberal democracy under the directory blaming it on chronic violence ambivalent forms of justice and repeated recourse to heavy handed repression
coupling loss also known as connection loss is the loss that occurs when energy is transferred from one circuit circuit element or medium to another coupling loss is usually expressed in the same units — such as watts or decibels — as in the originating circuit element or medium coupling loss in fiber optics refers to the power loss that occurs when coupling light from one optical device or medium to another see also optical return loss coupling losses can result from a number of factors in electronics see coupling electronics impedance mismatch between coupled components results in a reflection of a portion of the energy at the interface likewise in optical systems where there is a change in index of refraction most commonly at a fiber air interface a portion of the energy is reflected back into the source component another major source of optical coupling loss is geometrical as an example two fibers coupled end to end may not be precisely aligned with the result that the two cores overlap somewhat light exiting the source fiber at a portion of its core that is not aligned with the core of the receiving fiber will not in general be coupled into the second fiber while some such light will be coupled into the second fiber it is not likely to be efficiently coupled nor will it generally travel in an appropriate mode in the second fiber similarly even for two perfectly aligned cores where there is a gap of any significant distance between the two fibers there will be some geometric loss due to spread of the beam some percentage of the light rays exiting the source fiber face will not intersect the second fiber within its entrance cone
coupon leverage or leverage factor is the amount by which a reference rate is multiplied to determine the floating interest rate payable by an inverse floater some debt instruments leverage the particular effects of interest rate changes most commonly in inverse floaters as an example an inverse floater with a multiple may pay interest at the rate or coupon of 22 percent minus the product of 2 times the 1 month london interbank offered rate libor the coupon leverage is 2 in this example and the reference rate is the 1 month libor
in mathematics the courant – friedrichs – lewy cfl condition is a necessary condition for convergence while solving certain partial differential equations usually hyperbolic pdes numerically by the method of finite differences it arises in the numerical analysis of explicit time integration schemes when these are used for the numerical solution as a consequence the time step must be less than a certain time in many explicit time marching computer simulations otherwise the simulation will produce incorrect results the condition is named after richard courant kurt friedrichs and hans lewy who described it in their 1928 paper
couvade syndrome also called sympathetic pregnancy is a proposed condition in which a partner experiences some of the same symptoms and behavior of an expectant mother these most often include minor weight gain altered hormone levels morning nausea and disturbed sleep patterns in more extreme cases symptoms can include labor pains postpartum depression and nosebleeds the labor pain symptom is commonly known as sympathy pain couvade syndrome is not recognized as a real syndrome by many medical professionals its source is a matter of debate some believe it to be a psychosomatic condition while others believe it may have biological causes relating to hormone changes
couvelaire uterus also known as uteroplacental apoplexy is a life threatening condition in which loosening of the placenta abruptio placentae causes bleeding that penetrates into the uterine myometrium forcing its way into the peritoneal cavity
the coventry bedworth urban area has a population of 359 262 according to the 2011 census which is an increase of 3 from the 2001 census figure of 348 068 this makes it the 17 th largest conurbation in the england and wales by population it is also one of the most densely populated the largest settlement is coventry population 325 949 which is within the west midlands county bedworth population 30 648 and binley woods population 2 665 are the other main parts of the conurbation and both lie in the county warwickshire in the districts of nuneaton and bedworth and the borough of rugby respectively there are no other towns in the conurbation there is a very small amount of green belt between the coventry bedworth urban area and the nuneaton urban area in the north however with the development of industrial and retail units in south nuneaton the two conurbations are virtually connected and also between coventry and kenilworth a larger area of green belt exists between coventry and the greater west midlands urban area which extends to about 5 miles
the covering problem of rado is an unsolved problem in geometry concerning covering planar sets by squares it was formulated in 1928 by tibor radó and has been generalized to more general shapes and higher dimensions by richard rado
in combinatorics and computer science covering problems are computational problems that ask whether a certain combinatorial structure covers another or how large the structure has to be to do that covering problems are minimization problems and usually linear programs whose dual problems are called packing problems the most prominent examples of covering problems are the set cover problem which is equivalent to the hitting set problem and its special cases the vertex cover problem and the edge cover problem
covering sickness or dourine french from the arabic darina meaning mangy said of a female camel feminine of darin meaning dirty is a disease of horses and other members of the family equidae the disease is caused by trypanosoma equiperdum which belongs to an important genus of parasitic protozoa and is the only member of the genus that is spread through sexual intercourse the occurrence of dourine is notifiable in the european union under legislation from the oie there currently is no vaccine and although clinical signs can be treated there is no cure
joachim bodamer created the term prosopagnosia in 1947 which is a disorder where individuals have an inability to recognize faces of people individuals with this disorder do not have the ability to overtly recognize faces but discoveries have been made showing that people with this disorder have the ability to covertly recognize faces covert facial recognition is the unconscious recognition of familiar faces by people with prosopagnosia the individuals who express this phenomenon are unaware that they are recognizing the faces of people they have seen before there are two types of prosopagnosia congenital and acquired congential prosopagnosia is an inability to recognize faces without a history of brain damage while acquired prosopagnosia is caused by damage to the right occipital temporal region of the brain in the 1950 s it was theorized that the right cerebral hemisphere was involved in facial recognition and in the 1960 s this theory was supported by many experiments although the ability for overt facial recognition is inhibited in patients with prosopagnosia there have been many studies done which show that some of these individuals may have the ability to recognize familiar faces covertly these experiments have used behavioral and physiological measures in order to demonstrate covert facial recognition a common physiological measure that is used is the measure of autonomic activity by using skin conductance responses scr which show a larger response in individuals with prosopagnosia who are shown pictures of familiar faces compared to pictures of unfamiliar faces
cowaramup bombora also known as cowie bombie or simply cow bombie is a big wave open ocean surf break found on the south west coast of western australia it is located 2 kilometres offshore west of gracetown which is near the town of margaret river world renowned for its surf and is 265 km south of the capital city perth the break first came to the world ’ s attention back in 2007 when local damon eastaugh won the big wave award after riding a wave estimated to be more than 50 feet it doesn t break often requiring huge swells from the southern ocean but these can produce very large waves often in excess of 40 ft with some contending for the biggest wave in australia at over 60 ft its name comes from cowaramup the name of the small local townsite and bombora an indigenous australian term for an area of large sea waves breaking over a shallow area cow bombie is also the name of an award winning shiraz grown locally in margaret river and named after the break the break was featured in the 2013 documentary series storm surfers 3 d which described it as on its day the tallest wave in australia where tom carroll survived a near death wipeout while surfing with ross clarke jones it also featured in the 2011 documentary film fighting fear in 2011 western australian surfer damien warr won the oakley biggest wave award for his ride on cow bombie in february 2015 jarryd foster 27 won the oakley biggest wave award for his ride on cow bombie mick corbett was also a 2015 finalist for the same award with his cow bombie ride on 26 june 2015 australian surfer felicity palmateer 22 became the first woman to surf cow bombie on 2 march 2016 the oakley big wave awards 2015 2016 were announced with two of the three major awards coming from cow bombie zac haynes won biggest paddle in and justin holland won biggest wave in australian waters finishing 2 nd and 3 rd respectively for ride of the year all three contenders for biggest wave were at cow bombie
cowardice is a trait wherein fear and excess self concern override doing or saying what is right good and of help to others or oneself in a time of need — it is the opposite of courage as a label cowardice indicates a failure of character in the face of a challenge many military codes of justice proscribe cowardice in combat as a crime punishable by death note the phrase shot at dawn as an opposite of an action or trait that many existing and formerly extant cultures demand cowardice rates as a character flaw that many societies and their representatives stigmatize and or punish
cowden syndrome also known as cowden s disease and multiple hamartoma syndrome is a rare autosomal dominant inherited disorder characterized by multiple non cancerous tumor like growths called hamartomas which typically are found in the skin mucous membranes mouth nasal membranes gi tract thyroid gland and breast tissue while the hamartomas are benign people with cowden syndrome are at increased risk of certain forms of cancer including breast thyroid uterus endometrial and kidney cancers cowden syndrome is associated with mutations in pten a tumor suppressor gene that cause the pten protein not to work properly leading to hyperactivity of the mtor pathway these mutations lead to characteristic features including macrocephaly intestinal hamartomatous polyps benign skin tumors multiple trichilemmomas papillomatous papules and acral keratoses and dysplastic gangliocytoma of the cerebellum lhermitte duclos disease in addition there is a predisposition to breast carcinoma follicular carcinoma of the thyroid and endometrial carcinoma
cowhide is the natural unbleached skin and hair of a cow it retains the original coloring of the animal cowhides are a product of the food industry from cattle other cows are killed specifically for their skin cowhide can also be processed into a leather which can be used to make such things as shoes wallets leather jackets and belts
cowpox is an infectious disease caused by the cowpox virus the virus part of the orthopoxvirus family is closely related to the vaccinia virus the virus is zoonotic meaning that it is transferable between species such as from animal to human the transferral of the disease was first observed in dairymaids who touched the udders of infected cows and consequently developed the signature pustules on their hands cowpox is more commonly found in animals other than bovines such as rodents cowpox is similar to but much milder than the highly contagious and often deadly smallpox disease its close resemblance to the mild form of smallpox and the observation that dairymaids were immune from smallpox inspired the first smallpox vaccine created and administered by english physician edward jenner the word “ vaccination ” coined by jenner in 1796 is derived from the latin root vaccinus meaning of or from the cow once vaccinated a patient develops antibodies that make him her immune to cowpox but they also develop immunity to the smallpox virus or variola virus the cowpox vaccinations and later incarnations proved so successful that in 1980 the world health organization announced that smallpox was the first disease to be eradicated by vaccination efforts worldwide other orthopox viruses remain prevalent in certain communities and continue to infect humans such as the cowpox virus cpxv in europe vaccinia in brazil and monkeypox virus in central and west africa
coxa valga is a deformity of the hip where the angle formed between the head and neck of the femur and its shaft is increased usually above 135 degrees it is caused by a slipped epiphysis of the femoral head the differential diagnosis includes neuromuscular disorders i e cerebral palsy spinal dysraphism poliomyelitis skeletal dysplasias and juvenile idiopathic arthritis
coxa vara is a deformity of the hip whereby the angle between the head and the shaft of the femur is reduced to less than 120 degrees this results in the leg being shortened and the development of a limp it is commonly caused by injury such as a fracture it can also occur when the bone tissue in the neck of the femur is softer than normal causing it to bend under the weight of the body this may either be congenital or the result of a bone disorder the most common cause of coxa vara is either congenital or developmental other common causes include metabolic bone diseases e g paget s disease of bone post perthes deformity osteomyelitis and post traumatic due to improper healing of a fracture between the greater and lesser trochanter shepherd s crook deformity is a severe form of coxa vara where the proximal femur is severely deformed with a reduction in the neck shaft angle beyond 90 degrees it is most commonly a sequela of osteogenesis imperfecta pagets disease osteomyelitis tumour and tumour like conditions e g fibrous dysplasia coxa vara can happen in cleidocranial dysostosis
crabtree hot springs is a geological phenomenon in lake county california about 25 miles 40 km north of upper lake it is located on private property and closed to the public it lies at an elevation of 2 257 feet 688 m there is a cluster of four natural hot springs at this location in an isolated narrow winding steep walled canyon on the north bank of the rice fork of the eel river about one fourth mile downriver from its junction with salt creek three of the hot springs are aligned in one area at a large swimming hole while the fourth hot spring is about 60 feet 18 m back upriver the temperature of the hottest spring is 106 ° f 41 ° c with a flow rate of about 10 us gallons 38 l per minute
crack closure is a phenomenon in fatigue loading during which the crack remains in a closed position even though some external tensile force is acting on the material during this process the crack opens only at stress above a particular stress this is due to factors such as plastic deformation or phase transformation during crack propagation corrosion of crack surfaces presence of fluids in the crack or roughness at cracked surfaces this provides a longer life for fatigued material than expected by slowing the crack growth rate the crack closure effect helps explain a wide range of fatigue data it has become the default interpretation of load ratio effects it is used in almost all fatigue life prediction models however it is virtually impossible to predict the effects of crack closure experimentally δk δkmax δkmin δkeffective δkmax – kopening δkeffective ≤ δk
crack tip opening displacement ctod is the displacement at the original crack tip and the 90 ° intercept lefm linear elastic fracture mechanics is not valid this assumption was proven when a unique relationship between ctod and the j integral was established
cracked tooth syndrome abbreviated to cts and also termed cracked cusp syndrome split tooth syndrome or incomplete fracture of posterior teeth is where a tooth has incompletely cracked but no part of the tooth has yet broken off sometimes it is described as a greenstick fracture the symptoms are very variable making it a notoriously difficult condition to diagnose
cradle cap is a yellowish patchy greasy scaly and crusty skin rash that occurs on the scalp of recently born babies it is usually not itchy and does not bother the baby cradle cap most commonly begins sometime in the first 3 months similar symptoms in older children are more likely to be dandruff than cradle cap the rash is often prominent around the ear the eyebrows or the eyelids it may appear in other locations as well where it is called seborrhoeic dermatitis rather than cradle cap some countries use the term pityriasis capitis for cradle cap it is extremely common with about half of all babies affected most of them have a mild version of the disorder severe cradle cap is rare
cramp rings are rings anciently worn as a cure for cramp and falling sickness or epilepsy the legend is that the first one was presented to edward the confessor by a pilgrim on his return from jerusalem its miraculous properties being explained to the king at his death it passed into the keeping of the abbot of westminster by whom it was used medically and was known as st edwards ring from that time the belief grew that the successors of edward inherited his powers and that the rings blessed by them worked cures hence arose the custom for the successive sovereigns of england each year on good friday formally to bless a number of cramp rings a service was held prayers and psalms were said and holy water which had been blessed in the name of the father son and holy ghost was poured over the rings which were always of gold or silver and made from the metal that the king offered to the cross on good friday the ceremony survived to the reign of mary i but the belief in the curative powers of similar circlets of sacred metal has lingered on even to the present day
cramp fasciculation syndrome cfs is a rare peripheral nerve hyperexcitability disorder it is more severe than the related and common disorder known as benign fasciculation syndrome it causes fasciculations cramps pain fatigue and muscle stiffness similar to those seen in neuromyotonia another related condition patients with cfs like those with neuromyotonia may also experience paresthesias most cases of cramp fasciculation syndrome are idiopathic cramp fasciculation syndrome is diagnosed by clinical examination and electromyography emg fasciculation is the only abnormality if any seen with emg cramp fasciculation syndrome is a chronic condition treatment options include anti seizure medications such as carbamazepine immunosuppressive drugs and plasmapheresis
cranial nerve disease is an impaired functioning of one of the twelve cranial nerves although it could theoretically be considered a mononeuropathy it is not considered as such under mesh it is possible for a disorder of more than one cranial nerve to occur at the same time if a trauma occurs at a location where many cranial nerves run together such as the jugular fossa a brainstem lesion could also cause impaired functioning of multiple cranial nerves but this condition would likely also be accompanied by distal motor impairment a neurological examination can test the functioning of individual cranial nerves and detect specific impairments
craniodiaphyseal dysplasia also known as cdd or lionitis is an extremely rare autosomal recessive bone disorder that causes calcium to build up in the skull disfiguring the facial features and reducing life expectancy these calcium deposits decrease the size of cranial foramina and can also decrease the hole in the cervical spinal canal in the few cases recorded most of the sufferers died in childhood the underlying genetics are uncertain
craniofacial abnormalities are congenital musculoskeletal disorders which primarily affect the cranium and facial bones they are associated with the development of the pharyngeal arches approximately 5 of the uk or usa population present with dentofacial deformities requiring orthognathic surgery jaw surgery and orthodontics brace therapy as a part of their definitive treatment
craniomandibular osteopathy also known as lion s jaw is a developmental disease in dogs causing extensive bony changes in the mandible and skull in this disease a cyclical resorption of normal bone and replacement by immature bone occurs along the inner and outer surfaces of the affected bones it usually occurs between the ages of 3 and 8 months breeds most commonly affected include the west highland white terrier scottish terrier cairn terrier and boston terrier it is rare in large breed dogs but it has been reported symptoms include firm swelling of the jaw drooling pain and difficulty eating it is an inherited disease especially in westies in which it has been recognized as an autosomal recessive trait canine distemper has also been indicated as a possible cause as has e coli infection which could be why it is seen occasionally in large breed dogs growth of lesions will usually stop around the age of one year and possibly regress this timing coincides with the normal completion of endochondral bone growth and ossification if the disease is extensive especially around the tympanic bulla middle ear then the prognosis is guarded a similar disease seen in young bullmastiffs is known as calvarial hyperostotic syndrome it is also similar to human infantile cortical hyperostosis it is characterized by irregular progressive bony proliferation and thickening of the cortical bone of the calvaria which is part of the skull asymmetry of the lesions may occur which makes it different from craniomandibular osteopathy symptoms include painful swelling of the skull fever and lymph node swelling in most cases it is self limiting
craniometaphyseal dysplasia autosomal dominant is a disorder is a rare skeletal disorder that results from a heterozygous mutation in human homologous of progress in ankylosis gene ankh abnormal bone overgrowth occurs from the beginning of a child s life as well as throughout their lifetime resulting in the narrowing of the cranial formania this leads to cranial nerve and facial features compression in addition this disorder is located on the 5 p chomsome
craniopagus twins are conjoined twins who are fused at the cranium this condition occurs in about 10 20 babies in every million births in the united states among this small group cephalic conjoining or craniopagus twinning represents the rarest of congenital abnormalities only accounting for 2 6 of all conjoined twins additionally conjoined twins are genetically identical and always share the same sex the union in craniopagus twins may occur on any portion of the calvarium but does not include either the face or the foramen magnum the thorax and abdomen are separate and each twin has its own ubilicus and umbilical cord the union may involve the entire diameter of the head or only a small portion this suggests that although there are many different kinds of variabilities already known in the scientific community there are an infinite amount of variations that can occur most of these variations are based on the rotation of one twin s skull to the other and in fact the different phenotypic sub groups of craniopagus twins are based on all these rotational conformations each of these factors rotation spot of union affect the development of the brain the vascular system within the brain and overall wellness of life both of the twins have outside the womb relatively few craniopagus twins survive the perinatal period approximately 40 of conjoined twins are stillborn and an additional 33 die within the immediate perinatal period usually from organ abnormalities and failure however 25 of craniopagus twins survive and can be considered for a surgical separation and several attempts occur yearly worldwide in the last half century the many advances in medicine including brain imaging neuro anaesthesia and neurosurgical techniques have proven that a successful outcome is possible following separation of total craniopagus twins
craniopharyngioma is a type of brain tumor derived from pituitary gland embryonic tissue that occurs most commonly in children but also in men and women in their 50 s and 60 s people may present with bitemporal inferior quadrantanopia leading to bitemporal hemianopsia as the tumor may compress the optic chiasm it has a point prevalence of approximately 2 100 000 craniopharyngiomas are also known as rathke pouch tumors hypophyseal duct tumors or adamantinomas
cranioschisis greek κρανιον kranion skull and schisis σχίσις split is a developmental birth defect involving the skull in this disease the cranium fails to close completely especially at the occipital region thus the brain is exposed to the amnios and eventually degenerates causing anencephaly
craniosynostosis from cranio cranium syn together ostosis relating to bone is a condition in which one or more of the fibrous sutures in an infant skull prematurely fuses by turning into bone ossification thereby changing the growth pattern of the skull because the skull cannot expand perpendicular to the fused suture it compensates by growing more in the direction parallel to the closed sutures sometimes the resulting growth pattern provides the necessary space for the growing brain but results in an abnormal head shape and abnormal facial features in cases in which the compensation does not effectively provide enough space for the growing brain craniosynostosis results in increased intracranial pressure leading possibly to visual impairment sleeping impairment eating difficulties or an impairment of mental development combined with a significant reduction in iq craniosynostosis occurs in one in 2000 births craniosynostosis is part of a syndrome in 15 to 40 of the patients but it usually occurs as an isolated condition
craniosynostosis – anal anomalies – porokeratosis syndrome also known as cap syndrome is a cutaneous condition inherited in an autosomal recessive fashion
craniotabes is softening or thinning of the skull in infants and children which may be normally present in newborns it is seen mostly in the occipital and parietal bones the bones are soft and when pressure is applied they will collapse underneath it when the pressure is relieved the bones will usually snap back into place the term cranio tabes is derived from the latin words cranium for skull and tabes for wasting any condition that affects bone growth most notably rickets from vitamin d deficiency marasmus syphilis or thalassemia can cause craniotabes if present during a time of rapid skull growth most especially during gestation and infancy it can be a normal feature in premature infants it is the first sign in children and infants with rickets
cranio – lenticulo – sutural dysplasia clsd or boyadjiev jabs syndrome is a neonatal infancy disease caused by a disorder in the 14 th chromosome it is an autosomal recessive disorder meaning that both recessive genes must be inherited from each parent in order for the disease to manifest itself the disease causes a significant dilation of the endoplasmic reticulum in fibroblasts of the host with clsd due to the distension of the endoplasmic reticulum export of proteins such as collagen from the cell is disrupted the production of sec 23 a protein is involved in the pathway of exporting collagen the copii pathway but a missense mutation causes and underproduction of sec 23 a which inhibits the pathway affecting collagen secretion this decrease in collagen secretion can lead to the bone defects that are also characteristic of the disease such as skeletal dysplasia and under ossification decreased collagen in clsd affected individuals contributes to improper bone formation because collagen is a major protein in the extracellular matrix and contributes to its proper mineralization in bones it has also been hypothesized that there are other defects in the genetic code besides sec 23 a that contribute to the disorder
crankcase dilution is a phenomenon of internal combustion engines in which unburned diesel or gasoline accumulates in the crankcase excessively rich fuel mixture or incomplete combustion allows a certain amount of fuel to pass down between the pistons and cylinder walls and dilute the engine oil it is more common in situations where fuel is injected at a very high pressure such asating oil from the cylinder walls travel past the piston rings and collect in the oil pan thus increasing wear and also diluting the lubricating oil since the less volatile components of the fuel will have the greatest tendency to condense the degree of crankcase oil dilution is directly related to the end volatility temperatures of the mixture
craquelure french craquelé italian crettatura is the fine pattern of dense cracking formed on the surface of materials either as part of the process of ageing or of their original formation or production the term is most often used to refer to tempera or oil paintings where it is a sign of age that is also sometimes induced in forgeries and ceramics where it is often deliberate and usually called crackle it can also develop in old ivory carvings and painted miniatures on an ivory backing are prone to craquelure
crashworthiness is the ability of a structure to protect its occupants during an impact this is commonly tested when investigating the safety of aircraft and vehicles depending on the nature of the impact and the vehicle involved different criteria are used to determine the crashworthiness of the structure crashworthiness may be assessed either prospectively using computer models e g ls dyna msc dytran madymo or experiments or retrospectively by analyzing crash outcomes several criteria are used to assess crashworthiness prospectively including the deformation patterns of the vehicle structure the acceleration experienced by the vehicle during an impact and the probability of injury predicted by human body models injury probability is defined using criteria which are mechanical parameters e g force acceleration or deformation that correlate with injury risk a common injury criterion is the head impact criterion hic crashworthiness is assessed retrospectively by analyzing injury risk in real world crashes often using regression or other statistical techniques to control for the myriad of confounders that are present in crashes
when going through withdrawal craving is a psychological urge to administer a discontinued medication or recreational drug
a crawl space vent is a penetration in the wall of a building which allows air to circulate from the crawl space beneath the building to the exterior
a crayfish party is a traditional summertime eating and drinking celebration in the nordic countries the tradition originated in sweden where a crayfish party is called a kräftskiva the tradition has also spread to finland via its swedish speaking population a similar tradition exists in the baltic countries in particular in lithuania and latvia crayfish parties are generally held during august a tradition that started because crayfish harvesting in sweden was for most of the 20 th century legally limited to late summer today the kräftpremiär date in early august has no legal significance dining is traditionally outdoors but in practice the party is often driven indoors by bad weather or aggressive mosquitoes customary party accessories are comical paper hats paper tablecloths paper lanterns often depicting the man in the moon and bibs a rowdy atmosphere prevails amid noisy eating and traditional drinking songs snapsvisa the alcohol consumption is often high especially when compared to the amount of food actually eaten it is considered customary to suck the juice out of the crayfish before shelling it akvavit and other kinds of snaps are served as well as beer the crayfish are boiled in salt water and seasoned with fresh dill – preferably crown dill harvested after the plant has flowered – then served cold and eaten with one ’ s fingers bread mushroom pies surströmming strong västerbotten cheese salads and other dishes are served buffet style
crazing is the phenomenon that produces a network of fine cracks on the surface of a material for example in a glaze layer crazing frequently precedes fracture in some glassy thermoplastic polymers crazing occurs in regions of high hydrostatic tension or in regions of very localized yielding which leads to the formation of interpenetrating microvoids and small fibrils if an applied tensile load is sufficient these bridges elongate and break causing the microvoids to grow and coalesce as microvoids coalesce cracks begin to form
creatine transporter defect ctd is an x linked disorder of creatine metabolism caused by defective transport of creatine into the brain the condition was initially described in reports in 2001 hemizygous males with this condition show intellectual disability speech delay seizures and behavioural abnormalities heterozygous females can have varying symptoms ctd is caused by mutations in the slc 6 a 8 gene located at the xq 28 short arm of the sex chromosome clinically it resembles the two other forms of cerebral creatine deficiencies ccd s l arginine glycine amidinotransferase deficiency and guanidinoacetate methyltransferase deficiency
in software engineering creational design patterns are design patterns that deal with object creation mechanisms trying to create objects in a manner suitable to the situation the basic form of object creation could result in design problems or in added complexity to the design creational design patterns solve this problem by somehow controlling this object creation creational design patterns are composed of two dominant ideas one is encapsulating knowledge about which concrete classes the system uses another is hiding how instances of these concrete classes are created and combined creational design patterns are further categorized into object creational patterns and class creational patterns where object creational patterns deal with object creation and class creational patterns deal with class instantiation in greater details object creational patterns defer part of its object creation to another object while class creational patterns defer its object creation to subclasses five well known design patterns that are parts of creational patterns are the abstract factory pattern which provides an interface for creating related or dependent objects without specifying the objects concrete classes builder pattern which separates the construction of a complex object from its representation so that the same construction process can create different representations factory method pattern which allows a class to defer instantiation to subclasses prototype pattern which specifies the kind of object to create using a prototypical instance and creates new objects by cloning this prototype singleton pattern which ensures that a class only has one instance and provides a global point of access to it
a creative work is a manifestation of creative effort including fine artwork sculpture paintings writing literature filmmaking and musical composition creative works have in common a degree of arbitrariness such that it is improbable that two people would independently create the same work at its base creative work involves two main steps — having an idea and then turning that idea into a reality the term is frequently u copyright
creativity is a phenomenon whereby something new and somehow valuable is formed the created item may be intangible such as an idea a scientific theory a musical composition or a joke or a physical object such as an invention a literary work or a painting scholarly interest in creativity involves many definitions and concepts pertaining to a number of disciplines psychology cognitive science education philosophy particularly philosophy of science technology theology sociology linguistics business studies songwriting and economics covering the relations between creativity and general intelligence mental and neurological processes personality type and creative ability creativity and mental health the potential for fostering creativity through education and training especially as augmented by technology the maximisation of creativity for national economic benefit and the application of creative resources to improve the effectiveness of teaching and learning
a credit limit is the maximum amount of credit that a financial institution or other lender will extend to a debtor for a particular line of credit sometimes called a credit line line of credit or a tradeline for example it is the most that a credit card company will allow a card holder to take out at once on a credit card this limit is based on a variety of factors ranging from an individual s ability to make interest payments an organization s cashflow or ability to repay the credit card debt and is an obligation of the consumer to pay just like all other parts of the balance
crenated tongue also called scalloped tongue pie crust tongue lingua indentata or crenulated tongue is a descriptive term for the appearance of the tongue when there are indentations along the lateral borders the sides as the result of compression of the tongue against the adjacent teeth the oral mucosa in the area of crenation is usually of normal color but there may be erythema redness if exposed to a high degree of friction or pressure crenated tongue is usually asymptomatic and harmless it is not a disease as such but usually results from habits where the tongue is pressed against the lingual surfaces the side facing the tongue of the dental arches or from any cause of macroglossia enlarged tongue which in itself has many causes such as down syndrome where crenation is caused by parafunctional habits there may also be associated bruxism linea alba or morsicatio buccarum
creola bodies are a histopathologic finding indicative of asthma found in a patient s sputum they are ciliated columnar cells sloughed from the bronchial mucosa of a patient with asthma other common findings in the sputum of asthma patients include charcot leyden crystals curschmann s spirals and eosinophils and excessive amounts of sputum in a study by yoshihara et al 60 of pediatric asthmatic patients demonstrating acute symptoms were found to have creola bodies in their sputum these patients had increased levels of neutrophil mediated cytokine activity concluding that epithelial damage is associated with a locally enhanced chemotactic signal for and activity of neutrophils but not eosinophils during acute exacerbations of paediatric asthma
the crespi effect leo p aul crespi 1916 – 2008 is a behavioural phenomenon observed in rats in a repeatedly carried out task such as finding food in a maze the running speed of the rat is proportional to the size of the reward it obtained on the previous trial the more food reward that was given to it last time upon completion of the task the faster it will run when attempting to complete the same task the effect also works in reverse it is important to note that the size of the reward has little or no influence on the speed of learning but that it does have an influence on the performance of tasks already learned
cretinism is a condition of severely stunted physical and mental growth due to untreated congenital deficiency of thyroid hormone congenital hypothyroidism usually due to maternal hypothyroidism
creutzfeldt – jakob disease cjd is a degenerative neurological disease that is incurable and invariably fatal cjd is at times called a human form of mad cow disease bovine spongiform encephalopathy or bse however given that bse is believed to be the cause of variant creutzfeldt – jakob disease vcjd in humans the two are often confused cjd is caused by an infectious agent called a prion prions are misfolded proteins that replicate by converting their properly folded counterparts in their host to the same misfolded structure they possess cjd causes the brain tissue to degenerate rapidly and as the disease destroys the brain the brain develops holes and the texture changes to resemble that of a kitchen sponge
cri du chat syndrome also known as chromosome 5 p deletion syndrome 5 p − said minus syndrome or lejeune ’ s syndrome is a rare genetic disorder due to a missing part deletion of chromosome 5 its name is a french term cat cry or call of the cat referring to the characteristic cat like cry of affected children it was first described by jérôme lejeune in 1963 the condition affects an estimated 1 in 50 000 live births across all ethnicities and is more common in females by a 4 3 ratio
the criegee rearrangement is a rearrangement reaction named after rudolf criegee
crigler – najjar syndrome or cns is a rare inherited disorder affecting the metabolism of bilirubin a chemical formed from the breakdown of the heme in red blood cells the disorder results in a form of nonhemolytic jaundice which results in high levels of unconjugated bilirubin and often leads to brain damage in infants the disorder is inherited in an autosomal recessive manner this syndrome is divided into types i and ii with the latter sometimes called arias syndrome these two types along with gilbert s syndrome dubin – johnson syndrome and rotor syndrome make up the five known hereditary defects in bilirubin metabolism unlike gilbert s syndrome only a few hundred cases of cns are known
crime analysis is a law enforcement function that involves systematic analysis for identifying and analyzing patterns and trends in crime and disorder information on patterns can help law enforcement agencies deploy resources in a more effective manner and assist detectives in identifying and apprehending suspects crime analysis also plays a role in devising solutions to crime problems and formulating crime prevention strategies quantitative social science data analysis methods are part of the crime analysis process though qualitative methods such as examining police report narratives also play a role
organized crime in el salvador is a serious problem that has brought tragedy to many places sufficient efforts to understand or deal with this phenomenon in this small central american country have not been made there are an estimated 25 000 gang members at large in el salvador with another 9 000 in prison the most well known gangs called maras in colloquial salvadoran spanish are mara salvatrucha and their rivals calle 18 maras are hunted by death squads including sombra negra newer rivals also include the rising mara the rebels 13 criminal youth gangs run lives in el salvador with an estimation of at least 60 000 young people belonging to gangs today el salvador experiences some of the highest murder rates in the latin america it is also considered an epicenter of the gang crisis along with guatemala and honduras as of march 2012 el salvador has seen a 40 drop in crime due to what the salvadoran government called a gang truce in early 2012 there were on average of 16 killings per day but in late march that number dropped to fewer than five per day and on april 14 2012 for the first time in over three years there were no killings in the country overall there were 411 killings in the month of january 2012 but in march the number was 188 more than a 40 reduction in crime all of this has been happening while crime in neighboring honduras has risen to an all time high
crimean – congo hemorrhagic fever cchf is a widespread tick borne viral disease that is endemic in africa the balkans the middle east and asia the virus is a member of the bunyaviridae family of rna viruses it is a zoonotic disease carried by several domestic and wild animals while clinical disease is rare in infected animals it is severe in infected humans with a mortality rate of 10 40 outbreaks of illness are usually attributable to hyalomma tick bites or contact with infected animals or people
criminal transmission of hiv is the intentional or reckless infection of a person with the human immunodeficiency virus hiv this is often conflated in laws and in discussion with criminal exposure to hiv which does not require the transmission of the virus and often as in the cases of spitting and biting does not include a realistic means of transmission some countries or jurisdictions including some areas of the u s have enacted laws expressly to criminalize hiv transmission or exposure charging those accused with criminal transmission of hiv others including the united kingdom charge the accused under existing laws with such crimes as murder fraud canada manslaughter attempted murder or assault
in applied mathematics and astrodynamics in the theory of dynamical systems a crisis is the sudden appearance or disappearance of a strange attractor as the parameters of a dynamical system are varied this global bifurcation occurs when a chaotic attractor comes into contact with an unstable periodic orbit or its stable manifold as the orbit approaches the unstable orbit it will diverge away from the previous attractor leading to a qualitatively different behaviour crises can produce intermittent behaviour grebogi ott romeiras and yorke distinguished between three types of crises the first type a boundary or an exterior crisis the attractor is suddenly destroyed as the parameters are varied in the postbifurcation state the motion is transiently chaotic moving chaotically along the former attractor before being attracted to a fixed point periodic orbit quasiperiodic orbit another strange attractor or diverging to infinity in the second type of crisis an interior crisis the size of the chaotic attractor suddenly increases the attractor encounters an unstable fixed point or periodic solution that is inside the basin of attraction in the third type an attractor merging crisis two or more chaotic attractors merge to form a single attractor as the critical parameter value is passed note that the reverse case sudden appearance shrinking or splitting of attractors can also occur the latter two crises are sometimes called explosive bifurcations while crises are sudden as a parameter is varied the dynamics of the system over time can show long transients before orbits leave the neighbourhood of the old attractor typically there is a time constant τ for the length of the transient that diverges as a power law τ ≈ p − pc γ near the critical parameter value pc the exponent γ is called the critical crisis exponent there also exist systems where the divergence is stronger than a power law so called super persistent chaotic transients
a crisis plan is the physical manifestation of crisis management with respect to the creation of a real document digital or otherwise outlining a personal or organizational reaction to crisis examples of a crisis plan could include a map of evacuation routes an outline of a personal wellness recovery action a list of emergency supplies a cpr manual or a corporate disaster contingency plan a crisis plan could be stored or generated in digital form and be represented through the deployment of such as a smart phone app usb key pdf file format or various other translations of a literal document every crisis is different and individual plans vary by necessity crisis plan implementation for emergency situations is assisted by modern technology there are numerous apps available for smart phones and other mobile technology platforms that promote enhanced crisis plan implementation and situational awareness one example is the cpr choking app for iphone and ipad developed in part by the university of washington and king county ems
crispiness or crispness is the gustatory sensation of brittleness in the mouth such that the food item shatters immediately upon mastication crispiness differs from crunchiness in that a crunchy food continues to provide its material sensation after a few chews on the other hand a crispy food quickly loses the taut equilibrium of its material such as a tightly wrapped sausage a delicately wrapped item is usually crisp unlike such food items as loosely or unwrapped unfresh fruit or a wax coated cheese it is possible for a food to be crispy crunchy or both
crisscross heart is a type of congenital heart defect where the right atrium is closely associated with the left ventricle in space and the left atrium is closely associated with the right ventricle although it is classified as a defect the criss cross is more of a spatial anomaly than a functional one and it is possible for the heart to have relatively normal functioning
in psychometrics criterion or concrete validity is the extent to which a measure is related to an outcome criterion validity is often divided into concurrent and predictive validity concurrent validity refers to a comparison between the measure in question and an outcome assessed at the same time in standards for educational psychological tests it states concurrent validity reflects only the status quo at a particular time predictive validity on the other hand compares the measure in question with an outcome assessed at a later time although concurrent and predictive validity are similar it is cautioned to keep the terms and findings separated concurrent validity should not be used as a substitute for predictive validity without an appropriate supporting rationale an example of concurrent validity is a comparison of the scores of the clep college algebra exam with course grades in college algebra to determine the degree to which scores on the clep are related to performance in a college algebra class an example of predictive validity is a comparison of scores on the sat with first semester grade point average gpa in college this assesses the degree to which sat scores are predictive of college performance
critical closing pressure is the internal pressure at which a blood vessel collapses and closes completely if blood pressure falls below critical closing pressure then the vessels collapse this happens during the measurement of blood pressure with a sphygmomanometer at resting state the arterial critical closing pressure is 20 mmhg critical closing pressure in arteries is higher than the mean vascular filling pressure that develops after death 7 mmhg therefore arteries collapse after death then fill up with air once the dissection begins in severe haemorrhage blood loss leads to a significant reduction in pressure this combined with activity in the sympathetic autonomic nerves supplying smooth muscle leads to vasoconstriction to the extent that the vessels may collapse this occurs at the critical closing pressure closing off blood supply to tissues which can lead to toxic shock
critical code studies ccs is an emerging academic subfield related to software studies digital humanities cultural studies computer science human computer interface and the diy do it yourself maker culture its primary focus is on the cultural significance of computer code without excluding or focusing solely upon the code s functional purpose as introduced by mark c marino critical code studies electronic book review critical code studies was initially a method by which scholars can read and explicate code the way we might explicate a work of literature but the concept also draws upon espen aarseth s conception of a cybertext as a mechanical device for the production and consumption of verbal signs cybertext 21 arguing that in order to understand a digital artifact we must also understand the constraints and capabilities of the authoring tools used by the creator of the artifact as well as the memory storage and interface required for the user to experience the digital artifact evidence that ccs has gained momentum since 2006 include an article by matthew kirschenbaum in the chronicle of higher education ccs sessions at the modern language association in 2011 that were packed with attendees several academic conferences devoted wholly to critical code studies and a book devoted to the explication of a single line of computer code titled 10 print chr 205 5 rnd 1 goto 10 montfort et al mit press
critical illness polyneuropathy cip and critical illness myopathy cim are overlapping syndromes of diffuse symmetric flaccid muscle weakness occurring in critically ill patients and involving all extremities and the diaphragm with relative sparing of the cranial nerves cip and cim have similar symptoms and presentations and are often distinguished largely on the basis of specialized electrophysiologic testing or muscle and nerve biopsy the causes of cip and cim are unknown though they are thought to be a possible neurological manifestation of systemic inflammatory response syndrome corticosteroids and neuromuscular blocking agents which are widely used in intensive care may contribute to the development of cip and cim as may elevations in blood sugar which frequently occur in critically ill patients cip was first described by charles f bolton in a series of five patients combined cip and cim was first described by nicola latronico in a series of 24 patients
a critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction the critical mass of a fissionable material depends upon its nuclear properties specifically the nuclear fission cross section its density its shape its enrichment its purity its temperature and its surroundings the concept is important in nuclear weapon design
critical opalescence is a phenomenon which arises in the region of a continuous or second order phase transition originally reported by charles cagniard de la tour in 1823 in mixtures of alcohol and water its importance was recognised by thomas andrews in 1869 following his experiments on the liquid gas transition in carbon dioxide many other examples have been discovered since the phenomenon is most commonly demonstrated in binary fluid mixtures such as methanol and cyclohexane as the critical point is approached the sizes of the gas and liquid region begin to fluctuate over increasingly large length scales as the density fluctuations become of a size comparable to the wavelength of light the light is scattered and causes the normally transparent liquid to appear cloudy tellingly the opalescence does not diminish as one gets closer to the critical point where the largest fluctuations can reach even centimetre proportions confirming the physical relevance of smaller fluctuations in 1908 the polish physicist marian smoluchowski became the first to ascribe the phenomenon of critical opalescence to large density fluctuations in 1910 albert einstein showed that the link between critical opalescence and rayleigh scattering is quantitative
a criticality accident is an uncontrolled nuclear chain reaction it is sometimes referred to as a critical excursion or a critical power excursion and represents the unintentional assembly of a critical mass of a given fissile material such as enriched uranium or plutonium in an unprotected environment a critical or supercritical fission reaction one that is sustained in power or increasing in power generally only occurs inside reactor cores and occasionally within test environments a criticality accident occurs when the same reaction is achieved unintentionally and in an unsafe environment though dangerous and frequently lethal to humans within the immediate area the critical mass formed is still incapable of producing a nuclear detonation of the type seen in fission bombs as the reaction lacks the many engineering elements that are necessary to induce explosive supercriticality the heat released by the nuclear reaction will typically cause the fissile material to expand so that the nuclear reaction becomes subcritical again within a few seconds in the history of atomic power development 60 criticality accidents have occurred including 22 in collections of fissile materials located in process environments outside of a nuclear reactor or critical experiments assembly although process accidents occurring outside of reactors are characterized by a large release of radiation the release is localized and has caused fatal radiation exposure only to persons very near to the event less than 1 metre resulting in 14 fatalities no criticality accidents have resulted in nuclear explosions
cro magnon 1 is a fossilized human skull of the sub species homo sapiens sapiens it was discovered with other cro magnon specimens in les eyzies france by louis lartet in 1868 it is dated to 27 680 ± 270 before present bp the cranial cavity measures 1600 cubic centimeters cm 3 the capacity of a modern adult human s cranial cavity is 1200 1700 cm 3
croatia rediviva ča kaj što – baštinski dani is a croatian poetical manifestation gathering poets of all croatian dialects functioning as literary languages the founder of the festival is the croatian poet physician and ambassador drago štambuk he is also the author of the wall of poetry zid od versi at the central square in selca onto which plates of the wreathed poets poetae oliveati are mounted with engraved year of the wreathing name of the poet and a few verses carved into the bračian marble the principal idea of the festival is that of the threefoldness of the croatian language and the idea of koinéisation mixing of all three croatian dialects čakavian kajkavian and štokavian as an expression of language commonness organisers of the manifestation are the association hrvatski sastanak 1888 and the croatian writers association the festival is held annually in the picturesque village of selca at the island of brač usually in mid july even though there were cases where it was held much earlier such as the first one which was held on holy saturday march 30 1991 every poet reads his own verses in one of the three croatian literary idioms at the main stone covered square of stjepan radić in front of numerous interested admirers of the croatian literary word the pinnacle of the festival is the election of the most successful poet who is crowned with the wreath of olive leaves the decision is made by a three member jury composed of the founder and earlier wreathees oliveati the crowned poet poeta oliveatus and the founder then choose the verses that shall be engraved into the marble plate and mounted onto the wall of poetry of the central selcan square right in front of the church of the christ the king the versified plate is of white brač marble every five years the founder edits and publishes the selection of the poems of the wreathed poets that were read during the festivals of the period entitled maslinov vijenac the olive wreath so far three titles have been published 1996 2001 and 2005
crohn s disease is a type of inflammatory bowel disease ibd that may affect any part of the gastrointestinal tract from mouth to anus signs and symptoms often include abdominal pain diarrhea which may be bloody if inflammation is severe fever and weight loss other complications may occur outside the gastrointestinal tract and include anemia skin rashes arthritis inflammation of the eye and feeling tired the skin rashes may be due to infections as well as pyoderma gangrenosum or erythema nodosum bowel obstruction also commonly occurs and those with the disease are at greater risk of bowel cancer crohn s disease is caused by a combination of environmental immune and bacterial factors in genetically susceptible individuals it results in a chronic inflammatory disorder in which the body s immune system attacks the gastrointestinal tract possibly directed at microbial antigens while crohn s is an immune related disease it does not appear to be an autoimmune disease in that the immune system is not being triggered by the body itself the exact underlying immune problem is not clear however it may be an immunodeficiency state about half of the overall risk is related to genetics with more than 70 genes found to be involved tobacco smokers are two times more likely to develop crohn s disease than nonsmokers it also often begins after gastroenteritis diagnosis is based on a number of findings including biopsy and appearance of the bowel wall medical imaging and description of the disease other conditions that can present similarly include irritable bowel syndrome and behçet s disease there are no medications or surgical procedures that can cure crohn s disease treatment options help with symptoms maintain remission and prevent relapse in those newly diagnosed a corticosteroid may be used for a brief period of time to quickly improve the disease with another medication such as either methotrexate or a thiopurine used to prevent recurrence an important part of treatment is the stopping of smoking among those who do one in five people with the disease are admitted to hospital each year and half of those with the disease will require surgery for the disease at some point over a ten year period while surgery should be used as little as possible it is necessary to address some abscesses certain bowel obstructions and cancers checking for bowel cancer via colonoscopy is recommended every few years starting eight years after the disease has begun crohn s disease affects about 3 2 per 1 000 people in europe and north america it is less common in asia and africa it has historically been more common in the developed world rates have however been increasing particularly in the developing world since the 1970 s inflammatory bowel disease resulted in 35 000 deaths in 2010 and those with crohn s disease have a slightly reduced life expectancy it tends to start in the teens and twenties although it can occur at any age males and females are equally affected the disease was named after gastroenterologist burrill bernard crohn who in 1932 together with two other colleagues at mount sinai hospital in new york described a series of patients with inflammation of the terminal ileum of the small intestine the area most commonly affected by the illness
crome syndrome is a rare disease defined by various symptoms including epilepsy intellectual disability eye and kidney problems it usually causes death in 4 to 8 months
cronkhite – canada syndrome is a rare syndrome characterized by multiple polyps of the digestive tract it is sporadic i e it does not seem to be a hereditary disease and it is currently considered acquired and idiopathic i e cause remains unknown about two thirds of patients are of japanese descent and the male to female ratio is 2 1 it was characterized in 1955
a crop circle or crop formation is a pattern created by flattening a crop usually a cereal the term was first coined in the early nineteen eighties by colin andrews crop circles have been described as all falling within the range of the sort of thing done in hoaxes by taner edis professor of physics at truman state university although obscure natural causes or alien origins of crop circles are suggested by fringe theorists there is no scientific evidence for such explanations and human causes are consistent for all crop circles the number of crop circles has substantially increased from the 1970 s to current times there has been little scientific study of them circles in the united kingdom are not spread randomly across the landscape but appear near roads areas of medium to dense population and cultural heritage monuments such as stonehenge or avebury in 1991 two hoaxers bower and chorley took credit for having created many circles throughout england after one of their circles was described by a circle investigator as impossible to be made by human hand formations are usually created overnight although some are reported to have appeared during the day in contrast to crop circles or crop formations archaeological remains can cause cropmarks in the fields in the shapes of circles and squares but they do not appear overnight and they are always in the same places every year
crop milk is a secretion from the lining of the crop of parent birds that is regurgitated to young birds it is found among all pigeons and doves where it is referred to as pigeon milk an analog to crop milk is also secreted from the esophagus of flamingos and some penguins
cross dominance also known as mixed handedness mixed dominance or increased hand efficiency is a motor skill manifestation where a person favors one hand for some tasks and the other hand for others for example a cross dominant person might write with the left hand but throw mainly with the right one it can also refer to mixed laterality which refers to a person favoring eyes ears feet or hands on one side of the body a person who is cross dominant can also be stronger on the opposite side of the body that they favor for example a right handed person can be stronger on the left side cross dominance can often be a problem when shooting or in activities that require aim although athletes can still achieve success in sports that require accuracy like passing in american football and shooting in basketball overall being mixed handed seems to result in better performance than being strongly handed for sports such as basketball ice hockey and field hockey what these sports have in common is that they require active body movements and also an ability to respond to either side the situation is reversed for racquet sports such as tennis individuals with crossed hand eye preference seem to be much better at gymnastics running and basketball because of the way in which congruent and crossed sided individuals position their bodies — stanley coren the left hander syndrome chapter 3
cross language information retrieval clir is a subfield of information retrieval dealing with retrieving information written in a language different from the language of the user s query for example a user may pose their query in english but retrieve relevant documents written in french to do so most of clir systems use translation techniques clir techniques can be classified into different categories based on different translation resources dictionary based clir techniques parallel corpora based clir techniques comparable corpora based clir techniques machine translator based clir techniques the first workshop on clir was held in zürich during the sigir 96 conference workshops have been held yearly since 2000 at the meetings of the cross language evaluation forum clef the term cross language information retrieval has many synonyms of which the following are perhaps the most frequent cross lingual information retrieval translingual information retrieval multilingual information retrieval the term multilingual information retrieval refers to clir in general but it also has a specific meaning of cross language information retrieval where a document collection is multilingual google search had a cross language search feature that was removed in 2013
cross phase modulation xpm is a nonlinear optical effect where one wavelength of light can affect the phase of another wavelength of light through the optical kerr effect
cross presentation is the ability of certain antigen presenting cells to take up process and present extracellular antigens with mhc class i molecules to cd 8 t cells cytotoxic t cells cross priming the result of this process describes the naive cytotoxic cd 8 t cell stimulation this process is necessary for immunity against most tumors and against viruses that do not readily infect antigen presenting cells or impair dendritic cell normal function it is also required for induction of cytotoxic immunity by vaccination with protein antigens for example tumour vaccination cross presentation is of particular importance because it permits the presentation of exogenous antigens which are normally presented by mhc ii on the surface of infected dendritic cells to be also presented by mhc i without infecting the dendritic cell cross presentation allows the dendritic cell to avoid using the endogenous proteasomal processing pathway which otherwise would divert cellular resources away from mhc ii presentation processes that present exogenous antigens after infection such a diversion could functionally impair the dendritic cell
cross species transmission cst is the phenomenon of transfer of viral infection from one species usually a similar species to another often seen in emerging viruses where one species transfers to another which in turn transfers to humans examples include hiv aids sars ebola swine flu rabies and bird flu the exact mechanism that facilitates the transfer is unknown however it is believed that viruses with a rapid mutation rate are able to overcome host specific immunological defenses this can occur between species that have high contact rates it can also occur between species with low contact rates but usually through an intermediary species bats for example are mammals and can directly transfer rabies to humans through bite and also through aerosolization of bat salvia and urine which are then absorbed by human mucous membranes in the nose mouth and eyes similarity between species for example transfer between mammals is believed to be facilitated by similar immunological defenses other factors include geographic area intraspecies behaviours and phylogenetic relatedness virus emergence relies on two factors initial infection and sustained transmission
cross tolerance is a phenomenon that occurs when tolerance to the effects of a certain drug produces tolerance to another drug it often happens between two drugs with similar functions or effects – for example acting on the same cell receptor or affecting the transmission of certain neurotransmitters cross tolerance has been observed with pharmaceutical drugs such as anti anxiety agents and illicit substances and sometimes the two of them together often a person who uses one drug can be tolerant to a drug that has a completely different function this phenomenon allows one to become tolerant to a drug that they have never even used before
cross education is a neurophysiological phenomenon where an increase in strength is witnessed within an untrained limb following unilateral strength training in the opposite contralateral limb cross education can also be seen in the transfer of skills from one limb to the other
cross – mckusick – breen syndrome also known as cross syndrome hypopigmentation and microphthalmia and oculocerebral hypopigmentation syndrome is an extremely rare disorder characterized by white skin blond hair with yellow gray metallic sheen small eyes with cloudy corneas jerky nystagmus gingival fibromatosis and severe mental and physical retardation it was characterized in 1967
crossbite is a form of malocclusion where a tooth or teeth has a more buccal or lingual position that is the tooth is either closer to the cheek or to the tongue than its corresponding antagonist tooth in the upper or lower dental arch in other words crossbite is a lateral misalignment of the dental arches
in rail transport the crossing sequence is a pattern 2 long 1 short 1 long each about 2 seconds for the long 1 second each for the short spaces sounded by a locomotive horn or whistle as the train approaches and passes a grade crossing
crossmodal perception or cross modal perception is perception that involves interactions between two or more different sensory modalities examples include synesthesia sensory substitution and the mcgurk effect in which vision and hearing interact in speech perception crossmodal perception crossmodal integration and crossmodal plasticity of the human brain are increasingly studied in neuroscience to gain a better understanding of the large scale and long term properties of the brain a related research theme is the study of multisensory perception and multisensory integration
in humans the crotch is the bottom of the pelvis the region of the body where the legs join the torso and is often considered to include the groin and genitals this definition also applies to clothing where the crotch includes the area of a pair of trousers or shorts where the legs join together the bottom of the crotch defines one end of the inseam
croup also known as laryngotracheobronchitis is a type of respiratory infection that is usually caused by a virus the infection leads to swelling inside the wind pipe which interferes with normal breathing and produces the classic symptoms of barking cough stridor and a hoarse voice fever and runny nose may also be present these symptoms may be mild moderate or severe often it starts or is worse at night it normally lasts one to two days croup can be caused by a number of viruses including parainfluenza and influenza virus rarely is it due to a bacterial infection croup is typically diagnosed based on signs and symptoms after potentially more severe causes such as epiglottitis or an airway foreign body have been ruled out further investigations — such as blood tests x rays and cultures — are usually not needed many cases of croup are preventable by immunization for influenza and diphtheria croup is usually treated with a single dose of steroids by mouth in more severe cases inhaled epinephrine may also be used hospitalization is required in one to five percent of cases croup is a relatively common condition that affects about 15 of children at some point it most commonly occurs between 6 months and 5 years of age but may rarely be seen in children as old as fifteen it is slightly more common in males than females it occurs most often in autumn before vaccination croup was frequently caused by diphtheria and was often fatal this cause is now very rare in the western world due to the success of the diphtheria vaccine
crouzon syndrome is an autosomal dominant genetic disorder known as a branchial arch syndrome specifically this syndrome affects the first branchial or pharyngeal arch which is the precursor of the maxilla and mandible since the branchial arches are important developmental features in a growing embryo disturbances in their development create lasting and widespread effects this syndrome is named after octave crouzon a french physician who first described this disorder he noted the affected patients were a mother and her daughter implying a genetic basis first called craniofacial dysostosis the disorder was characterized by a number of clinical features this syndrome is caused by a mutation in the fibroblast growth factor receptor ii located on chromosome 10 breaking down the name craniofacial refers to the skull and face and dysostosis refers to malformation of bone now known as crouzon syndrome the characteristics can be described by the rudimentary meanings of its former name what occurs is that an infant s skull and facial bones while in development fuse early or are unable to expand thus normal bone growth cannot occur fusion of different sutures leads to different patterns of growth of the skull examples include trigonocephaly fusion of the metopic suture brachycephaly fusion of the coronal suture dolichocephaly fusion of the sagittal suture plagiocephaly unilateral premature closure of lambdoid and coronal sutures oxycephaly fusion of coronal and lambdoidal sutures kleeblattschaedel premature closure of all sutures
crouzonodermoskeletal syndrome is a disorder characterized by the premature joining of certain bones of the skull craniosynostosis during development and a skin condition called acanthosis nigricans some of the signs and symptoms of crouzonodermoskeletal syndrome are similar to those seen with crouzon syndrome they include prematurely fused skull bones which affect the shape of the head and face wide set bulging eyes due to shallow eye sockets eyes that do not point in the same direction strabismus a small beaked nose and an underdeveloped upper jaw people with these conditions are generally of normal intelligence several features distinguish crouzonodermoskeletal syndrome from crouzon syndrome people with crouzonodermoskeletal syndrome have acanthosis nigricans a skin condition characterized by thick dark velvety skin in body folds and creases including the neck and underarms in addition subtle changes may be seen in the bones of the spine vertebrae noncancerous growths called cementomas may develop in the jaw during young adulthood crouzonodermoskeletal syndrome is rare the condition is seen in about 1 per million people
crowding is a perceptual phenomenon where the recognition of objects or graphemes presented away from the fovea is impaired by the presence of other neighbouring objects sometimes called flankers it has been suggested that crowding occurs due to mandatory integration of the crowded objects by a texture processing neural mechanism crowding deficits have been specifically found in neuropsychiatric disorders such as schizophrenia and autism and may have profound clinical implications in these disorders if objects remain within your visual field over time then priming psychology begins to occur and the objects become less cluttered
the crowe sign or crowe s sign is the presence of axillary armpit freckling in people with neurofibromatosis type i von recklinghausen s disease these freckles occur in up to 30 of people with the disease and their presence is one of seven diagnostic criteria for neurofibromatosis freckles can also be present in the intertriginous area in neurofibromatosis such as the inguinal fold submamillary areas and nape of the neck this medical sign is named after frank w crowe july 2 1919 april 29 1987 an american physician who practiced dermatology in boise idaho in 1956 crowe et al recognised the autosomal dominant heredity of neurofibromatosis and the use of 6 or more café au lait spots to diagnose the condition in 1964 crowe published work on the use of axillary freckling in its diagnosis which is now referred to as the crowe sign he noticed that axillary freckles are present in about 20 30 of patients with neurofibromatosis but he did not see any in patients who did not have neurofibromatosis axillary freckling also occurs in other disease processes that closely resemble nf 1 such as legius syndrome cafe au lait spots axillary freckling and macrocephaly without lisch nodules neurofibromas or cns tumors and homozygous hnpcc mutations cafe au lait spots axillary freckling and cutaneous neurofibromas in the setting of hereditary non polyposis colon cancer also known as lynch syndrome seen with family history of hnpcc and consanguinity
crown flash is a rare but observed phenomenon involving the brightening of a thunderhead crown followed by the appearance of aurora like streamers emanating into the clear atmosphere the current hypothesis is that sunlight is reflecting off or refracting through tiny ice crystals above the crown of a cumulonimbus cloud these ice crystals are aligned by the strong electro magnetic effects around the cloud so the effect may appear as a tall streamer or pillar of light when the electro magnetic field is disturbed by lightning flashes within the cloud the ice crystals are re orientated causing the light pattern to shift very rapidly and appear to dance in a strikingly mechanical fashion the effect may also sometimes known as a leaping sundog as with sundogs the observer would have to be in a specific position to see the effect which is not a self generated light such as seen in a lightning strike but rather a changing reflection refraction of the sunlight mentioned in nature in 1971 and in a letter to nature slightly earlier in the same year this phenomenon is regarded as rare and not well documented recently several youtube videos have emerged that appear to document this phenomenon
crown shyness is a phenomenon observed in some tree species in which the crowns of fully stocked trees do not touch each other forming a canopy with channel like gaps it is also known as canopy disengagement canopy shyness or intercrown spacing the phenomenon is most prevalent among trees of the same species but also occurs between trees of different species there exist many hypotheses as to why crown shyness is an adaptive behavior though prominent research suggest that it might inhibit spread of leaf eating insect larvae
crown sprouting is the ability of a plant to regenerate its shoot system after destruction usually by fire by activating dormant vegetative structures to produce regrowth from the root crown the junction between the root and shoot portions of a plant these dormant structures take the form of lignotubers or basal epicormic buds plant species that can accomplish crown sprouting are called crown resprouters distinguishing them from stem or trunk resprouters and like them are characteristic of fire prone habitats such as chaparral in contrast to plant fire survival strategies that decrease the flammability of the plant or by requiring heat to germinate crown sprouting allows for the total destruction of the above ground growth crown sprouting plants typically have extensive root systems in which they store nutrients allowing them to survive during fires and sprout afterwards early researchers suggested that crown sprouting species might lack species genetic diversity however research on gondwanan shrubland suggests that crown sprouting species have similar genetic diversity to seed sprouters some genera such as arctostaphylos and ceanothus have species that are both resprouters and not both adapted to fire california buckeye aesculus californica is an example of a western united states tree which can regenerate from its root crown after a fire event but can also regenerate by seed
crunchiness is the sensation of muffled grinding of a foodstuff crunchiness differs from crispness in that a crisp item is quickly atomized while a crunchy one offers sustained granular resistance to jaw action while crispness is difficult to maintain crunchiness is difficult to overcome crunchy foods are associated with freshness
a crus fracture is a fracture the lower legs bones meaning either or both of the tibia and fibula
a crush injury is injury by an object that causes compression of the body this form of injury is common following a natural disaster or after some form of trauma from a deliberate attack common concerns after an injury of this type are rhabdomyolysis and crush syndrome
crush syndrome also traumatic rhabdomyolysis or bywaters syndrome or ground beef blood gbb is a medical condition characterized by major shock and renal failure after a crushing injury to skeletal muscle crush injury is compression of extremities or other parts of the body that causes muscle swelling and or neurological disturbances in the affected areas of the body while crush syndrome is localized crush injury with systemic manifestations cases occur commonly in catastrophes such as earthquakes to victims that have been trapped under fallen or moving masonry victims of crushing damage present some of the greatest challenges in field medicine and may be among the few situations where a physician is needed in the field the most drastic response to crushing under massive objects may be field amputation even if it is possible to extricate the patient without amputation appropriate physiological preparation is mandatory where permissive hypotension is the standard for prehospital care fluid loading is the requirement in crush syndrome
in baking a crust is the outer hard skin of bread or the shell of a pie generally it is made up of at least shortening or another fat water flour and salt it may also include milk sugar or other ingredients that contribute to the taste or texture an egg or milk wash can be used to decorate the outside as well as coarse sugar a crust contributes to a pastry the ratio of ingredients and mixing method determines the texture of the crust if the flour is not well mixed with the shortening then water can bind to the available flour causing the gluten protein matrix to become over developed this would result in a tough crust as opposed to a flaky crust which is more desirable depending on the type of pastry the crust can be baked before it is filled or in baked baked together with the filling in pies two different types of crust exist one crust pie and two crust pie a two crust pie can have either a complete upper crust a lattice top or any of a variety of other decorative tops
cruveilhier – baumgarten disease or pégot cruveilhier – baumgarten disease is a rare medical condition in which the umbilical or paraumbilical veins are distended with an abdominal wall bruit the cruveilhier baumgarten bruit and palpable thrill portal hypertension with splenomegaly hypersplenism and oesophageal varices with a normal or small liver it was first described by pégot in 1833 and then by jean cruveilhier 1835 and paul clemens von baumgarten 1907 armstrong et al 1942 and steinburg and galambos 1967 described two different types of the condition cruveilhier baumgarten syndrome liver cirrhosis or portal hypertension is the cause of the distension of the paraumbilical veins i e an acquired condition in which the veins reopen due to high portal pressure cruveilhier – baumgarten disease the distension of the paraumbilical veins is due to failure of umbilical vein closure with little or no evidence of liver disease found on liver biopsy i e a congenital patency of the umbilical vein leading to portal hypertension
a cry break is a vocal break in a tone or note in a song it is characteristic in the singing tone of hank williams where a note seems to break and start over again there are notes that the singer sounds near to the point of starting to cry it is a technique that is used in country singing songs that deal with the issues of sorrow and loss are likely to contain cry breaks train whistles may also be played in this manner evoking the same emotions
crying is the shedding of tears in response to an emotional state the act of crying has been defined as a complex secretomotor phenomenon characterized by the shedding of tears from the lacrimal apparatus without any irritation of the ocular structures a related medical term is lacrimation which also refers to non emotional shedding of tears crying is also known as weeping wailing whimpering and bawling for crying to be described as sobbing it usually has to be accompanied by a set of other symptoms such as slow but erratic inhalation occasional instances of breath holding and muscular tremor a neuronal connection between the lacrimal gland tear duct and the areas of the human brain involved with emotion has been established there is debate among scientists over whether or not humans are the only animals that produce tears in response to emotional states charles darwin wrote in the expression of the emotions in man and animals that the keepers of indian elephants in the london zoo told him that their charges shed tears in sorrow tears produced during emotional crying have a chemical composition which differs from other types of tears they contain significantly greater quantities of the hormones prolactin adrenocorticotropic hormone leu enkephalin and the elements potassium and manganese
cryofibrinogenemia is defined by the presence of circulating cold insoluble complexes of fibrin fibrinogen fibronectin and fibrin split products with albumin immunoglobulins and plasma proteins that precipitate from the patient s plasma in the cold
cryofibrinogenemic purpura is a skin condition that manifests as painful purpura with slow healing ulcerations and edema of both feet during winter months
cryoglobulinemia or cryoglobulinaemia is a medical condition in which the blood contains large amounts of cryoglobulins – proteins mostly immunoglobulins themselves that become insoluble at reduced temperatures this should be contrasted with cold agglutinins which cause agglutination of red blood cells cryoglobulins typically precipitate at temperatures below normal body temperature 37 ° c and will dissolve again if the blood is heated the precipitated clump can block blood vessels and cause toes and fingers to become gangrenous cryoglobulinemia can be associated with various diseases such as multiple myeloma and hepatitis c infection cryoglobulins usually consist of igm directed against the fc region of igg
cryoglobulinemic purpura is a skin condition characterized by purpura and occurring most frequently in multiple myeloma and macroglobulinemia
cryoglobulinemic vasculitis is a skin condition presenting in roughly 15 of people with a circulating cryoprecipitable protein
cryoplanation also known as cryoplanation terraces is the alteration of a terrestrial surface by intense frost action that effectively reduces slope steepness and lowers mountain and hill peaks cryoplanation is a variant of pediplanation that is restricted to cold climates all the cryoplanation surfaces that exists at present date to the quaternary the term cryoplanation was introduced by kirk bryan in 1946 and it is a type of frost weathering that often modifies the landscape into terraces these terraces are called cryoplanation terraces czudek described cryoplanation terraces as gently inclined or nearly horizontal bedrock cut benches on slopes spurs and on broad interfluves that are formed by the parallel retreat of steeper slope segments under periglacial conditions additionally with the effect of cryoplanation on the landscape the vegetation on these frost altered terraces is also reshaped the vegetation tends to be uniquely uniform both laterally and vertically the results of this unique freeze thaw cycle are customarily found in arctic periglacial regions of eastern siberia and alaska they may also be found in areas that currently or have sometime in the past experienced intense seasonal freezing or permafrost the concept has been questioned according to hall and andré the theory has caused confusion because of “ the almost complete absence of actual data from active cryoplanation terraces ” it is judged that cryoplanation is unlikely to produce any large surfaces
cryopyrin associated periodic syndrome caps is a spectrum of autoinflammatory syndromes including familial cold autoinflammatory syndrome fcas formerly termed familial cold induced urticaria the muckle wells syndrome mws and neonatal onset multisystem inflammatory disease nomid also called chronic infantile neurologic cutaneous and articular syndrome or cinca they share many clinical features these syndromes are associated with mutations in nlrp 3 the gene encoding cryopyrin this is a component of the interleukin 1 inflammasome and mutations lead to unregulated production of interleukin 1 β monoclonal antibodies against interleukin 1 β such as canakinumab other interleukin 1 binding proteins such as rilonacept or interleukin 1 receptor antagonist for example anakinra can be used to treat these disorders
this article is about animals that are difficult to detect for the genus of grasses see crypsis genus for animals whose existence is not scientifically recognized see cryptid in ecology crypsis is the ability of an animal to avoid observation or detection by other animals it may be a predation strategy or an antipredator adaptation methods include camouflage nocturnality subterranean lifestyle and mimicry crypsis can involve visual olfactory with pheromones or auditory concealment when it is visual the term cryptic coloration effectively a synonym for animal camouflage is sometimes used but many different methods of camouflage are employed by animals
crypt is the library function which is used to compute a password hash that can be used to store user account passwords while keeping them relatively secure a passwd file the output of the function is not simply the hash – it is a text string which also encodes the salt usually the first two characters are the salt itself and the rest is the hashed result and identifies the hash algorithm used defaulting to the traditional one explained below this output string is what is meant for putting in a password record which may be stored in a plain text file more formally crypt provides cryptographic key derivation functions for password validation and storage on unix systems
cryptic pregnancy is a condition in which a pregnant woman is unaware of her pregnancy until reaching labour reasons the woman may be unaware of the pregnancy may include the woman being on weight affecting medication having regular menstrual bleeding a lack of symptoms of pregnancy and the fetus being unusually small cryptic pregnancy is in contrast to denial of pregnancy where the woman is subconsciously aware of her pregnancy but denies its existence it is estimated that 1 in 450 doesn t know her pregnancy status until week 20 or later more than halfway through the pregnancy and 1 in 2 500 is oblivious until she actually goes into labor
in histology cryptitis refers to inflammation of an intestinal crypt cryptitis is a non specific histopathologic finding that is seen in several conditions e g inflammatory bowel disease diverticular disease radiation colitis infectious colitis
crypto protestantism is an historical phenomenon that occurred on the territory of the habsburg empire it describes the attempt made after the protestant reformation to regain for catholicism parts of the empire that had become protestant the protestants in the areas that were re catholicised by force strove to retain their own confession inwardly while they outwardly pretended to accept catholicism with the 1782 edict of tolerance protestantism was again permitted and from that time on the protestants could live their faith openly once more
cryptococcosis also known as cryptococcal disease is a potentially fatal fungal disease it is caused by one of two species cryptococcus neoformans and cryptococcus gattii these were all previously thought to be subspecies of c neoformans but have now been identified as distinct species cryptococcosis is believed to be acquired by inhalation of the infectious propagule from the environment although the exact nature of the infectious propagule is unknown the leading hypothesis is the basidiospore created through sexual or asexual reproduction
a cryptogenic disease is a disease of which the cause is unknown it may be used in a particular case when the nature of the patient s condition is known but the cause has not been found e g cryptogenic stroke the word cryptogenic also appears in the names of some disease entities when the situation is sufficiently common to be considered a diagnosis in its own right e g cryptogenic fibrosing alveolitis cryptogenic idiopathic and primary may all be used in both these senses but cryptogenic is more likely to be used where there is presumed to be a simple cause but this happens to have eluded discovery cryptogenic is used in this technical sense in the description of epilepsy syndromes although the distinction has now been officially abandoned
a cryptographic hash function is a special class of hash function that has certain properties which make it suitable for use in cryptography it is a mathematical algorithm that maps data of arbitrary size to a bit string of a fixed size a hash function which is designed to also be a one way function that is a function which is infeasible to invert the only way to recreate the input data from an ideal cryptographic hash function s output is to attempt a brute force search of possible inputs to see if they produce a match bruce schneier has called one way hash functions the workhorses of modern cryptography the input data is often called the message and the output the hash value or hash is often called the message digest or simply the digest the ideal cryptographic hash function has four main properties it is quick to compute the hash value for any given message it is infeasible to generate a message from its hash value except by trying all possible messages a small change to a message should change the hash value so extensively that the new hash value appears uncorrelated with the old hash value it is infeasible to find two different messages with the same hash value cryptographic hash functions have many information security applications notably in digital signatures message authentication codes macs and other forms of authentication they can also be used as ordinary hash functions to index data in hash tables for fingerprinting to detect duplicate data or uniquely identify files and as checksums to detect accidental data corruption indeed in information security contexts cryptographic hash values are sometimes called digital fingerprints checksums or just hash values even though all these terms stand for more general functions with rather different properties and purposes
cryptomenorrhea or cryptomenorrhoea also known as hematocolpos is a condition where menstruation occurs but is not visible due to an obstruction of the outflow tract specifically the endometrium is shed but a congenital obstruction such as a vaginal septum or on part of the hymen retains the menstrual flow a patient with cryptomenorrhea will appear to have amenorrhea but will experience cyclic menstrual pain the condition is surgically correctable the patient usually presents at the age of puberty when the commencement of menstruation blood gets collected in the vagina and gives rise to symptoms
cryptophasia is a phenomenon of a language developed by twins identical or fraternal that only the two children could understand the word has its roots from crypto meaning secret and phasia meaning speech most linguists associate cryptophasia with idioglossia which is any language used by only one or very few people cryptophasia also differs from idioglossia on including mirrored actions like twin walk and identical mannerisms while sources claim that twins and children from multiple births develop this ability perhaps because of more interpersonal communication between themselves than with the parents there is inadequate scientific proof to verify these claims
cryptophthalmos is a rare congenital anomaly in which the skin is continuous over the eyeball with absence of eyelids it is classified into three types complete incomplete and abortive failure of eyelid separation can be associated with maldevelopment of the underlying cornea and microphthalmia cryptophthalmos usually occurs on both sides and occurs in association with other multiple malformations collectively referred to as fraser syndrome
cryptorchidism is the absence of one or both testes from the scrotum it is the most common birth defect of the male genitals about 3 of full term and 30 of premature infant boys are born with at least one undescended testis however about 80 of cryptorchid testes descend by the first year of life the majority within three months making the true incidence of cryptorchidism around 1 overall cryptorchidism may develop after infancy sometimes as late as young adulthood but that is exceptional cryptorchidism is distinct from monorchism the condition of having only one testicle the condition may occur on one or both sides it more commonly affects the right testis a testis absent from the normal scrotal position may be 1 anywhere along the path of descent from high in the posterior retroperitoneal abdomen just below the kidney to the inguinal ring 2 in the inguinal canal 3 ectopic having wandered from the path of descent usually outside the inguinal canal and sometimes even under the skin of the thigh the perineum the opposite scrotum or the femoral canal 4 undeveloped hypoplastic or severely abnormal dysgenetic 5 missing also see anorchia about two thirds of cases without other abnormalities are unilateral most of the other third involve both testes in 90 of cases an undescended testis can be felt in the inguinal canal in a small minority of cases missing testes may be found in the abdomen or appear to be nonexistent truly hidden undescended testes are associated with reduced fertility increased risk of testicular germ cell tumors and psychological problems when the boy is grown undescended testes are also more susceptible to testicular torsion and subsequent infarction and inguinal hernias without intervention an undescended testicle will usually descend during the first year of life but to reduce these risks undescended testes can be brought into the scrotum in infancy by a surgical procedure called an orchiopexy although cryptorchidism nearly always refers to congenital absence or maldescent a testis observed in the scrotum in early infancy can occasionally reascend move back up into the inguinal canal a testis which can readily move or be moved between the scrotum and canal is referred to as retractile the word is from the greek κρυπτός kryptos meaning hidden ὄρχις orchis meaning testicle cryptorchidism hypospadias testicular cancer and poor semen quality make up the syndrome known as testicular dysgenesis syndrome
cryptosporidiosis also known as crypto is a parasitic disease caused by cryptosporidium a genus of protozoan parasites in the phylum apicomplexa it affects the distal small intestine and can affect the respiratory tract in both immunocompetent i e individuals with a normal functioning immune system and immunocompromised e g persons with hiv aids individuals resulting in watery diarrhea with or without an unexplained cough in immunocompromised individuals the symptoms are particularly severe and can be fatal it is primarily spread through the fecal oral route often through contaminated water recent evidence suggests that it can also be transmitted via fomites in respiratory secretions cryptosporidium is the organism most commonly isolated in hiv positive patients presenting with diarrhea despite not being identified until 1976 it is one of the most common waterborne diseases and is found worldwide the parasite is transmitted by environmentally hardy microbial cysts oocysts that once ingested exist in the small intestine and result in an infection of intestinal epithelial tissue
cryptotia is the condition where an ear appears to have its upper portion buried underneath the side of the head the condition also involves underdeveloped scapha and antihelical crura cryptotia is also known as buried ear or hidden ear
crysodavarious cry sod a various also commonly known as crysod crysodavarious is an infection at the top of the throat adjacent to the tonsils crysodavarious can be caused from many different things e g irritants of certain types however crysodavarious is often called from a lack ofmoisture to the mouth this can also indicate dehydration but only in some cases crysodavarious was first discovered in 1923 by phillepe watson charmichael a spanish doctor who made his discovery whilst practicing in venezuela crysodavarious can come in many forms but commonly lasts about one half a daybut in some severe cases it can last up to 3 days in severe cases crysodavarious can result swelling and the area may become inflamed
crystal arthropathy is a class of joint disorder called arthropathy that is characterized by accumulation of tiny crystals in one or more joints polarizing microscopy and application of other crystallographic techniques have improved identification of different microcrystals including monosodium urate calcium pyrophosphate dihydrate calcium hydroxyapatite and calcium oxalate types include
crystalloluminescence is the effect of luminescence produced during crystallization the abstract of an article by b p chandra v kalia and s c datt of rani durgavati university jabulpur india entitled crystalloluminescence a new tool to determine the critical size of a crystal nucleus states there is a time lag between the achievement of supersaturation in a solution and the appearance of crystalloluminescence flashes from crystal nuclei the incubation time of crystalloluminescence decreases systematically with the concentration of the solution a new method based on crystalloluminescence measurements is proposed for the determination of the critical size of the crystal nucleus
cubehash is a cryptographic hash function submitted to the nist hash function competition by daniel j bernstein cubehash has a 128 byte state uses wide pipe construction and is arx based message blocks are xored into the initial bits of a 128 byte state which then goes through an r round bijective transformation between blocks the initial nist proposal cubehash 8 1 required about 200 cycles per byte after clarifications from nist the author changed the proposal to cubehash 16 32 which is approximately 16 times faster than cubehash 8 1 easily catching up to both sha 256 and sha 512 on the reference platform while still maintaining a comfortable security margin cubehash advanced to the second round of the competition but was not chosen as one of the 5 finalists the author tuned the parameters further since
cubitus valgus is a medical deformity in which the forearm is angled away from the body to a greater degree than normal when fully extended a small degree of cubitus valgus known as the carrying angle is acceptable and occurs in the general population when present at birth it can be an indication of turner syndrome or noonan syndrome it can also be acquired through fracture or other trauma the physiological cubitus valgus varies from 3 ° to 29 ° women usually have a more pronounced cubitus valgus than men the deformity can also occur as a complication of fracture of the lateral condyle of the humerus which may lead to tardy delayed ulnar nerve palsy the opposite condition is cubitus varus 736 02
cubitus varus varus means a deformity of a limb in which part of it is deviated towards the midline of the body is a common deformity in which the extended forearm is deviated towards midline of the body cubitus varus is often referred to as gunstock deformity due to the crooked nature of the healing the opposite condition is cubitus valgus
cuerito is pig skin pork rind from mexican cuisine venezuelan cuisine and spanish cuisine cuero is the spanish language word for leather or hide so cueritos means little leathers they are usually pickled in vinegar cueritos de vinagre and can be made with a spicy sauce the vinegar can be seasoned with pineapple dulce macho piloncillo cloves peppercorns chile de arbol and oregano there are also family recipes cueritos are used to make a type of cemita and can be used in other dishes like tostadas cueritos are sometimes served in a glass with strips of the pickled pork rind alongside a slaw of cabbage cucumber lime and chile sauce the mexican street food antojito known as tostilocos are made by slicing nacho flavored tostito chips vertically and topping them with cucumber cueritos lime juice valentina hot sauce chamoy tajín seasoning chile powder salt and japanese peanuts peanuts encased in a crunchy brown flour shell in acatlán hidalgo the feast in honor of the archangel michael is held from the 20 29 of september with religious events traditional dances and traditional foods such as cueritos made with chili pepper sauce and varieties of pulque pickling differentiates cueritos from chicharron which is fried pork skin in spain the chicharrón is the rind with fat still attached and cuerito is a rind with no fat attached in mexico chicharron is the cuerito or pig skin fried to a crisp like cracklings in the southern states and cueritos is soft deep fat fried pig skin chopped and used for tacos in mexico natural un cured cueritos usually the thick pig skin without the fat attached are always combined with macisa solid or thick meat in carnitas which is deep fat fried pig parts sold for tacos the tacos are served with a choice of meats chopped in 1 or 2 soft corn tortillas covered with chopped cilantro and onion and the choice of a hot chili sauce in every public market most carnecerias meat stores or many restaurants or other places that serve tacos the mexican equivalent of hot dogs or hamburgers
cultural bias is the phenomenon of interpreting and judging phenomena by standards inherent to one s own culture the phenomenon is sometimes considered a problem central to social and human sciences such as economics psychology anthropology and sociology some practitioners of the aforementioned fields have attempted to develop methods and theories to compensate for or eliminate cultural bias cultural bias occurs when people of a culture make assumptions about conventions including conventions of language notation proof and evidence they are then accused of mistaking these assumptions for laws of logic or nature numerous such biases exist concerning cultural norms for color location of body parts mate selection concepts of justice linguistic and logical validity acceptability of evidence and taboos
cultural humility is the “ ability to maintain an interpersonal stance that is other oriented or open to the other in relation to aspects of cultural identity that are most important to the person ” cultural humility is different from other culturally based training ideals because it focuses on self humility rather than achieving a state of knowledge or awareness cultural humility was formed in the physical healthcare field and adapted for therapists and social workers to increase the quality of their interactions with clients and community members
the culture of albania is the pattern of human activity and symbolism associated with albania and its people it has been shaped by the geography and profound history of albania
the culture of lahore is a manifestation of the lifestyle festivals literature music language politics cuisine and socio economic conditions of its people it is characterised by the blending of south asian middle eastern central asian and western influences lahore s culture is unique it is sometimes referred as the cultural capital or the heart of pakistan the city was a seat of the mughal empire and the sikh empire as well as the capital of punjab in mahmud ghaznavi s 11 th century empire and in the british empire presently it is the capital of the punjab province of pakistan
the culture of northern cyprus is the pattern of human activity and symbolism associated with northern cyprus and turkish cypriots it features significant elements influenced by or developed upon the culture of turkey but combines these elements with a unique cypriot approach and local traditions in common with greek cypriots as well as several other influences such as the british and contemporary western cultures
the culture of the united kingdom is influenced by the uk s history as a developed island country a liberal democracy and a major power its predominantly christian religious life and its composition of four countries — england northern ireland scotland and wales — each of which has distinct customs cultures and symbolism the wider culture of europe has also influenced british culture and humanism protestantism and representative democracy developed from broader western culture british literature music cinema art theatre comedy media television philosophy architecture and education are important aspects of british culture the united kingdom is also prominent in science and technology producing world leading scientists e g isaac newton and charles darwin and inventions sport is an important part of british culture numerous sports originated in the country including football the uk has been described as a cultural superpower and london has been described as a world cultural capital the industrial revolution which started in the uk had a profound effect on the socio economic and cultural conditions of the world as a result of the british empire significant british influence can be observed in the language law culture and institutions of a geographically wide assortment of countries including australia canada india the republic of ireland new zealand nigeria pakistan south africa the united states and english speaking caribbean nations these states are sometimes collectively known as the anglosphere and are among britain s closest allies in turn the empire also influenced british culture particularly british cuisine the cultures of england scotland wales and northern ireland are diverse and have varying degrees of overlap and distinctiveness
in the domain of technical analysis of market prices a cup and handle or cup with handle formation is a chart pattern consisting of a drop in the price and a rise back up to the original value followed a smaller drop and a rise past the previous peak it is interpreted as an indication of bullish sentiment in the market and possible further price increases the cup part of the pattern should be fairly shallow with a rounded or flat bottom not a v shaped one and ideally reach to the same price at the upper end of both sides the drop of the handle part should retrace about 30 to 50 of the rise at the end of the cup for stock prices the pattern may span from a few weeks to a few years but commonly the cup lasts from 1 to 6 months while the handle should only last for 1 to 4 weeks the cup and handle formation was defined by william o neil
a curl route also called a hitch or hook sometimes a button hook is a pattern run by a receiver in american football where the receiver appears to be running a fly pattern but after a set amount of steps or yards will quickly stop and turn around looking for a pass this generally works best when the defending corner or safety commits himself to guarding the fly and is unable to stop quickly enough to defend the pass a curl out on the sideline is often referred to as a comeback route the curl is a pattern used frequently by the west coast offensive scheme where quick and accurate passes are favored this route can also be used in what is called a screen where while the receiver is receiving the pass one or more linemen tight ends or running backs will run in the direction of the receiver in order to block the initial pursuing defenders so that the receiver has time and space to be able to run after the catch
curling s ulcer stress ulcer or a curling ulcer is an acute gastritis erosion resulting as a complication from severe burns when reduced plasma volume leads to ischemia and cell necrosis sloughing of the gastric mucosa the condition was first described in 1823 and named for a doctor thomas blizard curling who observed ten such patients in 1842 these stress ulcers actually shallow multiple erosions were once a common complication of serious burns presenting in over 10 of cases and especially common in child burn victims they result in perforation and hemorrhage more often than other forms of intestinal ulceration and had correspondingly high mortality rates at least 80 a similar condition involving elevated intracranial pressure is known as cushing s ulcer
the currarino syndrome also currarino triad is an inherited congenital disorder where 1 the sacrum the fused vertebrae forming the back of the pelvis is not formed properly 2 there is a mass in the presacral space in front of the sacrum and 3 there are malformations of the anus or rectum it can also cause an anterior meningocele or a presacral teratoma presacral teratoma usually is considered to be a variant of sacrococcygeal teratoma however the presacral teratoma that is characteristic of the currarino syndrome may be a distinct kind
currency depreciation is the loss of value of a country s currency with respect to one or more foreign reference currencies typically in a floating exchange rate system it is most often used for the unofficial decrease of the exchange rate due to market forces though sometimes it appears interchangeably with devaluation its opposite an increase of value of a currency is currency appreciation the depreciation of a country s currency refers to a decrease in the value of that country s currency for instance if the canadian dollar depreciates relative to the euro the exchange rate the canadian dollar price of euros rises it takes more canadian dollars to purchase 1 euro 1 eur 1 5 cad → 1 eur 1 7 cad when the canadian dollar depreciates relative to the euro canadian goods become more competitive in countries in the eurozone because their price when exchanged to euro will be lower the result will be an increase in canadian exports on the other hand european sellers that denominate their goods and services in euros will be less competitive because european products denominated in euros will be more expensive in canada in the financial market a currency s depreciation decreases the value of foreign investments in the country denominated in the local currency as more of an investor s currency would be required when the investment is repatriated similarly a currency depreciation will impact the book value of a business conducted in the depreciating country by a foreign corporation as well as its rate of return in relation to the head corporation s currency a foreign corporation would consider a foreign exchange hedge to protect itself from this foreign exchange risk the appreciation of a country s currency refers to an increase in the value of that country s currency continuing with the cad eur example if the canadian dollar appreciates relative to the euro the exchange rate falls it takes fewer canadian dollars to purchase 1 euro 1 eur 1 5 cad → 1 eur 1 4 cad when the canadian dollar appreciates relative to the euro the canadian dollar becomes less competitive this will lead to larger imports of european goods and services and lower exports of canadian goods and services
currency war also known as competitive devaluations is a condition in international affairs where countries seek to gain a trade advantage over other countries by causing the exchange rate of their currency to fall in relation to other currencies as the exchange rate of a country s currency falls exports become more competitive in other countries and imports into the country become more expensive both effects benefit the domestic industry and thus employment which receives a boost in demand from both domestic and foreign markets however the price increases for import goods as well as in the cost of foreign travel are unpopular as they harm citizens purchasing power and when all countries adopt a similar strategy it can lead to a general decline in international trade harming all countries historically competitive devaluations have been rare as countries have generally preferred to maintain a high value for their currency countries have generally allowed market forces to work or have participated in systems of managed exchanges rates an exception occurred when a currency war broke out in the 1930 s when countries abandoned the gold standard during the great depression and used currency devaluations in an attempt to stimulate their economies since this effectively pushes unemployment overseas trading partners quickly retaliated with their own devaluations the period is considered to have been an adverse situation for all concerned as unpredictable changes in exchange rates reduced overall international trade according to guido mantega former brazilian minister for finance a global currency war broke out in 2010 this view was echoed by numerous other government officials and financial journalists from around the world other senior policy makers and journalists suggested the phrase currency war overstated the extent of hostility with a few exceptions such as mantega even commentators who agreed there had been a currency war in 2010 generally concluded that it had fizzled out by mid 2011 states engaging in possible competitive devaluation since 2010 have used a mix of policy tools including direct government intervention the imposition of capital controls and indirectly quantitative easing while many countries experienced undesirable upward pressure on their exchange rates and took part in the ongoing arguments the most notable dimension of the 2010 – 11 episode was the rhetorical conflict between the united states and china over the valuation of the yuan in january 2013 measures announced by japan which were expected to devalue its currency sparked concern of a possible second 21 st century currency war breaking out this time with the principal source of tension being not china versus the us but japan versus the eurozone by late february concerns of a new outbreak of currency war had been mostly allayed after the g 7 and g 20 issued statements committing to avoid competitive devaluation after the european central bank launched a fresh programme of quantitative easing in january 2015 there was once again an intensification of discussion about currency war
the current solar income of the earth or an ecozone or ecoregion or any area is the amount of solar energy that falls on it as sunlight this is thought important in some branches of green economics as the ultimate measure of renewable energy buckminster fuller first described the concept in his 1970 paper cosmic costing contrasting the photosynthesis on which natural capital and sustainable infrastructural capital depend with the chemosynthesis of extracting and using fossil fuels paul hawken is a more recent advocate of the concept and views it as central to his notion of a restorative economy it remains a popular notion among those who believe that toxic waste and maintenance problems of direct solar energy devices can ultimately be overcome or that yields of passive or biological means of gathering and using this energy as biofuels can be made to approximate those of fossil fuels
currumbin alley is a surf break at currumbin on the gold coast in queensland australia the alley is one of the more famous breaks on the gold coast along with superbank and burleigh heads among others waves wrap around the point and towards the creek it is exposed to perfect beginners conditions towards the creek and some right handers towards the point there s also a great wave just across the channel called lacey s lane the alley marks the mouth of currumbin creek
the curse of rocky colavito is a phenomenon that supposedly prevents the cleveland indians baseball team from winning be it the world series the american league pennant reaching postseason play or even getting into a pennant race its origin is traced back to the unpopular trade of right fielder rocky colavito for harvey kuenn in 1960
cushing s disease is a cause of cushing s syndrome characterised by increased secretion of adrenocorticotropic hormone acth from the anterior pituitary secondary hypercortisolism this is most often as a result of a pituitary adenoma specifically pituitary basophilism or due to excess production of hypothalamus crh corticotropin releasing hormone tertiary hypercortisolism hypercorticism that stimulates the synthesis of cortisol by the adrenal glands pituitary adenomas are responsible for 80 of endogenous cushing s syndrome when excluding cushing s syndrome from exogenously administered corticosteroids this should not be confused with ectopic cushing syndrome or exogenous steroid use
cushing s syndrome is a collection of signs and symptoms due to prolonged exposure to cortisol signs and symptoms may include high blood pressure abdominal obesity but with thin arms and legs reddish stretch marks a round red face a fat lump between the shoulders weak muscles weak bones acne and fragile skin that heals poorly women may have more hair and irregular menstruation occasionally there may be changes in mood headaches and a chronic feeling of tiredness cushing s syndrome is caused by either excessive cortisol like medication such as prednisone or a tumor that either produces or results in the production of excessive cortisol by the adrenal glands cases due to a pituitary adenoma are known as cushing s disease it is the second most common cause of cushing s syndrome after medication a number of other tumors may also cause cushing s some of these are associated with inherited disorders such as multiple endocrine neoplasia type 1 and carney complex diagnosis requires a number of steps the first step is to check the medications a person takes the second step is to measure levels of cortisol in the urine saliva or in the blood after taking dexamethasone if this test is abnormal the cortisol may be measured late at night if the cortisol remains high a blood test for acth may be done to determine if the pituitary is involved most cases can be treated and cured if due to medications these can often be slowly stopped if caused by a tumor it may be treated by a combination of surgery chemotherapy and or radiation if the pituitary was affected other medications may be required to replace its lost function with treatment life expectancy is usually normal some in whom surgery is unable to remove the entire tumor have an increased risk of death about two to three people per million are affected each year it most commonly affects people who are 20 to 50 years of age women are affected three times more often than men a mild degree of overproduction of cortisol without obvious symptoms however is more common cushing s syndrome was first described by harvey cushing in 1932 cushing s syndrome may also occur in other animals including cats dogs and horses
a cushing ulcer named after harvey cushing is a gastric ulcer associated with elevated intracranial pressure it is also called von rokitansky cushing syndrome apart from in the stomach ulcers may also develop in the proximal duodenum and distal esophagus
custom in law is the established pattern of behavior that can be objectively verified within a particular social setting a claim can be carried out in defense of what has always been done and accepted by law related is the idea of prescription a right enjoyed through long custom rather than positive law customary law also consuetudinary or unofficial law exists where 1 a certain legal practice is observed and 2 the relevant actors consider it to be law opinio juris most customary laws deal with standards of community that have been long established in a given locale however the term can also apply to areas of international law where certain standards have been nearly universal in their acceptance as correct bases of action in example laws against piracy or slavery see hostis humani generis in many though not all instances customary laws will have supportive court rulings and case law that has evolved over time to give additional weight to their rule as law and also to demonstrate the trajectory of evolution if any in the interpretation of such law by relevant courts
customer success is the function at a company responsible for managing the technical and business relationships between a vendor and its customers with the intent of 1 maximizing the value that customers generate from the solutions they acquired from the vendor by making them as profitable and productive as possible and 2 maximizing the value the vendor can in turn derive from the customers resulting in sustainable corporate profits and growth customer success is an emerging but critical role in a company s success the function is most commonly used in the software world and most prevalent among software as a service saas companies because customer success is a nascent fast emerging field of business its organizational alignment and activities are still evolving there is still a large amount of variance with respect to its scope of responsibilities reporting structure terminology used for describing its activities metrics used for measuring its performance and more while deviations exist in the specifics of the function it always refers to the management of the relations between the vendor and the customers after the initial sale however successful companies do not only reorganize their teams between the pre and post sale and rename the post sale team customer success but also instill a culture of customer centricity in decision making and goals in fact the explosive growth of the saas economy fuels an increase not only in the importance of the customer success function but also in the scope of its appeal and relevance in the industry as put in the book customer success how innovative companies are reducing churn and growing recurring revenue customer success is really three different but closely related concepts 1 an organization 2 a discipline and 3 a philosophy
customer attrition also known as customer churn customer turnover or customer defection is the loss of clients or customers banks telephone service companies internet service providers pay tv companies insurance firms and alarm monitoring services often use customer attrition analysis and customer attrition rates as one of their key business metrics along with cash flow ebitda etc because the cost of retaining an existing customer is far less than acquiring a new one companies from these sectors often have customer service branches which attempt to win back defecting clients because recovered long term customers can be worth much more to a company than newly recruited clients companies usually make a distinction between voluntary churn and involuntary churn voluntary churn occurs due to a decision by the customer to switch to another company or service provider involuntary churn occurs due to circumstances such as a customer s relocation to a long term care facility death or the relocation to a distant location in most applications involuntary reasons for churn are excluded from the analytical models analysts tend to concentrate on voluntary churn because it typically occurs due to factors of the company customer relationship which companies control such as how billing interactions are handled or how after sales help is provided when companies are measuring their customer turnover they typically make the distinction between gross attrition and net attrition gross attrition is the loss of existing customers and their associated recurring revenue for contracted goods or services during a particular period net attrition is gross attrition plus the addition or recruitment of similar customers at the original location financial institutions often track and measure attrition using a weighted calculation called recurring monthly revenue or rmr in the 2000 s there are also a number of business intelligence software programs which can mine databases of customer information and analyze the factors that are associated with customer attrition such as dissatisfaction with service or technical support billing disputes or a disagreement over company policies more sophisticated predictive analytics software use churn prediction models that predict customer churn by assessing their propensity of risk to churn since these models generate a small prioritized list of potential defectors they are effective at focusing customer retention marketing programs on the subset of the customer base who are most vulnerable to churn
customer reference program crp also referred to as a customer reference programme outside of the usa is a business function frequently found in large business to business organizations customer reference program managers are responsible for gathering and fulfilling requests for references to help sales people obtain new clients and provide proof of customer success stories for industry analysts and the media
the cut and restore rope trick is a magic effect in which the performer cuts a piece of rope usually tied into a knot which then appears to be magically restored sometimes the trick is done with a piece of string a handkerchief or a turban instead of an actual rope
cutaneous b cell lymphomas constitute a group of diseases that occur less commonly than cutaneous t cell lymphoma and are characterized histologically by b cells that appear similar to those normally found in germinal centers of lymph nodes conditions included in this group are diffuse large b cell lymphoma primary cutaneous follicular lymphoma primary cutaneous marginal zone lymphoma intravascular large b cell lymphoma plasmacytoma plasmacytosis
cutaneous t cell lymphoma ctcl is a class of non hodgkin lymphoma which is a type of cancer of the immune system unlike most non hodgkin lymphomas which are generally b cell related ctcl is caused by a mutation of t cells the malignant t cells in the body initially migrate to the skin causing various lesions to appear these lesions change shape as the disease progresses typically beginning as what appears to be a rash which can be very itchy and eventually forming plaques and tumors before metastasizing to other parts of the body
cutaneous actinomycosis is a chronic disease that affects the deep subcutaneous tissue of the skin caused by an anaerobic gram positive filamentous type of bacteria in the genus actinomyces invasion of the soft tissue leads to the formation of abnormal channels leading to the skin surface external sinus tracts that discharge pale yellow sulfur granules this disease is uncommon and has non specific clinical features making it difficult to diagnose cervicofacial pulmonary thoracic and gastrointestinal forms exist yet cervicofacial disease accounts for two thirds of reported infections
cutaneous amoebiasis refers to a form of amoebiasis that presents primarily in the skin it can be caused by acanthamoeba or entamoeba histolytica when associated with acanthamoeba it is also known as cutaneous acanthamoebiasis it is also known as amoebiasis cutis balamuthia mandrillaris has been described as entering through the skin and it can have cutaneous expression
cutaneous ciliated cysts are a cutaneous condition characterized by solitary cysts located on the legs of females
cutaneous columnar cysts are a cutaneous condition a group of different cysts lined by columnar epithelium types of cysts included in this group are bronchogenic cyst branchial cyst thyroglossal duct cyst cutaneous ciliated cyst median raphe cyst
a cutaneous condition is any medical condition that affects the integumentary system — the organ system that encloses the body and includes skin hair nails and related muscle and glands the major function of this system is as a barrier against the external environment conditions of the human integumentary system constitute a broad spectrum of diseases also known as dermatoses as well as many nonpathologic states like in certain circumstances melanonychia and racquet nails while only a small number of skin diseases account for most visits to the physician thousands of skin conditions have been described classification of these conditions often presents many nosological challenges since underlying etiologies and pathogenetics are often not known therefore most current textbooks present a classification based on location for example conditions of the mucous membrane morphology chronic blistering conditions etiology skin conditions resulting from physical factors and so on clinically the diagnosis of any particular skin condition is made by gathering pertinent information regarding the presenting skin lesion s including the location such as arms head legs symptoms pruritus pain duration acute or chronic arrangement solitary generalized annular linear morphology macules papules and color red blue brown black white yellow the diagnosis of many conditions often also requires a skin biopsy which yields histologic information that can be correlated with the clinical presentation and any laboratory data
cutaneous diphtheria is an infection of the skin by corynebacterium diphtheriae it is also known as desert sore
cutaneous focal mucinosis is a skin condition characterized by a solitary nodule or papule
cutaneous horns also known by the latin name cornu cutaneum are unusual keratinous skin tumors with the appearance of horns or sometimes of wood or coral formally this is a clinical diagnosis for a conical projection above the surface of the skin they are usually small and localized but can in very rare cases be much larger although often benign they can also be malignant or premalignant
cutaneous larva migrans abbreviated clm is a skin disease in humans caused by the larvae of various nematode parasites of the hookworm family ancylostomatidae the most common species causing this disease in the americas is ancylostoma braziliense these parasites live in the intestines of dogs cats and wild animals and should not be confused with other members of the hookworm family for which humans are definitive hosts namely ancylostoma duodenale and necator americanus colloquially called creeping eruption due to its presentation the disease is also somewhat ambiguously known as ground itch or in some parts of the southern usa sandworms as the larvae like to live in sandy soil another vernacular name is plumber s itch the medical term clm literally means wandering larvae in the skin
cutaneous leishmaniasis also known as oriental sore tropical sore chiclero ulcer chiclero s ulcer or aleppo boil is the most common form of leishmaniasis affecting humans it is a skin infection caused by a single celled parasite that is transmitted by the bite of a phlebotomine sandfly there are about twenty species of leishmania that may cause cutaneous leishmaniasis this disease is considered to be a zoonosis an infectious disease that is naturally transmissible from vertebrate animals to humans with the exception of leishmania tropica — which is often an anthroponotic disease an infectious disease that is naturally transmissible from humans to vertebrate animals
cutaneous lupus mucinosis also known as papular and nodular mucinosis in lupus erythematosus papular and nodular mucinosis of gold and papulonodular mucinosis in lupus erythematosus is a cutaneous condition characterized by lesions that present as asymptomatic skin colored at times reddish 0 5 – 2 cm papules and nodules
cutaneous lymphoid hyperplasia also known as borrelial lymphocytoma lymphadenosis benigna cutis lymphocytoma cutis pseudolymphoma pseudolymphoma of spiegler and fendt sarcoidosis of spiegler and fendt spiegler – fendt lymphoid hyperplasia and spiegler – fendt sarcoid refers to a groups of benign cutaneous disorders characterized by collections of lymphocytes macrophages and dendritic cells in the skin conditions included in this groups are cutaneous lymphoid hyperplasia with nodular pattern a condition of the skin characterized by a solitary or localized cluster of asymptomatic erythematous to violaceous papules or nodules cutaneous lymphoid hyperplasia with bandlike and perivascular patterns a condition of the skin characterized by skin lesions that clinically resemble mycosis fungoides jessner lymphocytic infiltrate of the skin also known as benign lymphocytic infiltration of the skin jessner lymphocytic infiltration of the skin jessner – kanof lymphocytic infiltration of the skin and lymphocytic infiltrate of jessner is a cutaneous condition characterized by a persistent papular and plaque like skin eruption which can occur on the neck face and back and may re occur this is an uncommon skin disease and is a benign collection of lymph cells its cause is not known and can be hereditary it is named for max jessner it is thought to be equivalent to lupus erythematosus tumidus
cutaneous meningioma also known as heterotopic meningeal tissue and rudimentary meningocele is a developmental defect and results from the presence of meningocytes outside the calvarium
cutaneous perforating disorders include the following acquired perforating dermatosis acquired perforating collagenosis kyrle disease perforating folliculitis
a cutaneous sinus of dental origin is where a dental infection drains onto the surface of the skin of the face or neck this is uncommon as usually dental infections drain into the mouth typically forming a parulis gumboil cutaneous sinuses of dental origin tend to occur under the chin or mandible without elimination of the source of the infection the lesion tends to have a relapsing and remitting course with healing periods and periods of purulent discharge cutaneous sinus tracts may result in fibrosis and scarring whcich may cause cosmetic concern sometimes minor surgery is carried out to remove the residual lesion
cutaneous small vessel vasculitis also known as cutaneous leukocytoclastic angiitis cutaneous leukocytoclastic vasculitis cutaneous necrotizing venulitis and hypersensitivity angiitis is inflammation of small blood vessels usually post capillary venules in the dermis characterized by palpable purpura it is the most common vasculitis seen in clinical practice leukocytoclasis refers to the damage caused by nuclear debris from infiltrating neutrophils in and around the vessels subtypes of small vessel vasculitis include iga vasculitis henoch schönlein purpura acute hemorrhagic edema of infancy urticarial vasculitis cryoglobulinemic vasculitis erythema elevatum diutinum granuloma faciale
in film and video a cutaway shot is the interruption of a continuously filmed action by inserting a view of something else it is usually although not always followed by a cut back to the first shot when the cutaway avoids a jump cut the cutaway shot does not necessarily contribute any dramatic content of its own but is used to help the editor assemble a longer sequence for this reason editors choose cutaway shots related to the main action such as another action or object in the same location for example if the main shot is of a man walking down an alley possible cutaways may include a shot of a cat on a nearby dumpster or a shot of a person watching from a window overhead similarly a cutaway scene is the interruption of a scene with the insertion of another scene generally unrelated or only peripherally related to the original scene the interruption is usually quick and is usually although not always ended by a return to the original scene the effect is of commentary to the original scene frequently comic in nature
cuterebriasis is a parasitic disease affecting rodents lagomorphs hares rabbits pikas felines and canines the etiologic agent is the larval development of bot flies within the cuterebra or trypoderma genera which occurs obligatorily in rodents and lagomorphs respectively felines and canines serve as accidental hosts but research suggests only by trypoderma spp entrance into the body by first instar larva occurs via mucous membranes of natural orifices or open wounds as opposed to direct dermic penetration
cutis laxa also known as chalazoderma dermatochalasia dermatolysis dermatomegaly generalized elastolysis generalized elastorrhexis or pachydermatocele is a group of rare connective tissue disorders in which the skin becomes inelastic and hangs loosely in folds
cutis marmorata telangiectatica congenita or cmtc is a rare congenital vascular disorder that usually manifests in affecting the blood vessels of the skin the condition was first recognised and described in 1922 by cato van lohuizen a dutch pediatrician whose name was later adopted in the other common name used to describe the condition van lohuizen syndrome cmtc is also used synonymously with congenital generalized phlebectasia nevus vascularis reticularis congenital phlebectasia livedo telangiectatica congenital livedo reticularis and van lohuizen syndrome it should not be confused with the more general term cutis marmorata which refers to livedo reticularis caused by cold
cutis rhomboidalis nuchae is a cutaneous condition of the posterior neck characterized by deep furrowing of the skin
cutis verticis gyrata cvg is a superficial medical condition usually associated with thickening of the scalp the condition was first reported by alibert in 1837 who called it cutis sulcata a clinical description of the condition was provided by robert in 1843 and was named by unna in 1907 it has also been called robert unna syndrome bulldog scalp corrugated skin cutis verticis plicata and pachydermia verticis gyrata sufferers show visible folds ridges or creases on the surface of the top of the scalp the number of folds can vary from 2 to roughly 10 and are typically soft and spongy these folds cannot be corrected with pressure the condition typically affects the central and rear regions of the scalp but sometimes can involve the entire scalp hair loss can occur over time where the scalp thickens though hair within any furrows remains normal thus far due to the apparent rarity of the condition limited research exists and causes are as yet undetermined what is known is that the condition is not exclusively congenital
cutting is the separation of a physical object into two or more portions through the application of an acutely directed force implements commonly used for cutting are the knife and saw or in medicine and science the scalpel and microtome however any sufficiently sharp object is capable of cutting if it has a hardness sufficiently larger than the object being cut and if it is applied with sufficient force even liquids can be used to cut things when applied with sufficient force see water jet cutter
in operations research the cutting stock problem is the problem of cutting standard sized pieces of stock material such as paper rolls or sheet metal into pieces of specified sizes while minimizing material wasted it is an optimization problem in mathematics that arises from applications in industry in terms of computational complexity the problem is an np hard problem reducible to the knapsack problem the problem can be formulated as an integer linear programming problem
cyanide poisoning occurs when a living organism is exposed to a compound that produces cyanide ions cn − when dissolved in water common poisonous cyanide compounds include hydrogen cyanide gas and the crystalline solids potassium cyanide and sodium cyanide the cyanide ion halts cellular respiration by inhibiting the enzyme cytochrome c oxidase found in the mitochondria
a cyanohydrin reaction is an organic chemical reaction by an aldehyde or ketone with a cyanide anion or a nitrile to form a cyanohydrin this nucleophilic addition is a reversible reaction but with aliphatic carbonyl compounds equilibrium is in favor of the reaction products the cyanide source can be potassium cyanide sodium cyanide or trimethylsilyl cyanide with aromatic aldehydes such as benzaldehyde the benzoin condensation is a competing reaction the reaction is used in carbohydrate chemistry as a chain extension method for example that of d xylose
cyanosis is the appearance of a blue or purple coloration of the skin or mucous membranes due to the tissues near the skin surface having low oxygen saturation based on lundsgaard and van slyke s work it is classically described as occurring if 5 0 g dl of deoxyhemoglobin or greater is present this was based on an estimate of capillary saturation based on a mean of arterial versus peripheral venous blood gas measurements since estimation of hypoxia is usually now based either on arterial blood gas measurement or pulse oximetry this is probably an overestimate with evidence that levels of 2 0 g dl of deoxyhemoglobin may reliably produce cyanosis since however the presence of cyanosis is dependent upon there being an absolute quantity of deoxyhemoglobin the bluish color is more readily apparent in those with high hemoglobin counts than it is with those with anemia also the bluer color is more difficult to detect on deeply pigmented skin when signs of cyanosis first appear such as on the lips or fingers intervention should be made within 3 – 5 minutes because a severe hypoxia or severe circulatory failure may have induced the cyanosis the name cyanosis literally means the blue disease or the blue condition it is derived from the color cyan which comes from kyanós the greek word for blue
computer crime or cybercrime in canada is an evolving international phenomenon people and businesses in canada and other countries may be affected by computer crimes that may or may not originate within the borders of their country from a canadian perspective computer crime may be considered to be defined by the council of europe – convention on cybercrime november 23 2001 canada contributed and is a signatory to this international of criminal offences involving the use of computers offences against the confidentiality integrity and availability of computer data and systems computer related offences content related offences offences related to infringements of copyright and related rights and ancillary liability canada is also a signatory to the additional protocol to the convention on cybercrime concerning the criminalization of acts of a racist and xenophobic nature committed through computer systems january 28 2003 as of july 25 2008 canada had not yet ratified the convention on cybercrime or the additional protocol to the convention on cybercrime concerning the criminalization of acts of a racist and xenophobic nature committed through computer systems
cybersectarianism is the phenomenon of new religious movements and other groups using the internet for text distribution recruitment and information sharing
cyclaneusma needle cast is a fungal disease that is apart of the phylum ascomycota it infects plants that are of pine classification after infection by cyclaneusma most pines do not display symptoms until 10 months after the initial infection symptoms include needles developing yellow spots horizontal brown bands around the needles swelling of needles and off white fruiting bodies formed on infected needles because cyclaneusma is an ascomycete it produces two spore types an asexual conidiomata and sexual ascomycota spore controlling cyclaneusma has presented a challenge as the disease can survive on both living and dead needles during the winter months effective management methods include planting new pines in non shaded well drainable soil as well as spraying fungicide cyclaneusma needle cast is an important fungal disease because it directly impacts the commercial value of decorative pines as well as lumber
in many valued logic with linearly ordered truth values cyclic negation is a unary truth function that takes a truth value n and returns n − 1 as value if n is not the lowest value otherwise it returns the highest value for example let the set of truth values be 0 1 2 let denote negation and let p be a variable ranging over truth values for these choices if p 0 then p 2 and if p 1 then p 0 cyclic negation was originally introduced by the logician and mathematician emil post
cyclic neutropenia or cyclical neutropenia is a form of neutropenia a white blood cell deficiency that tends to occur every three weeks and lasts three to six days at a time due to changing rates of cell production by the bone marrow cyclic neutropenia is the result of autosomal dominantly inherited mutations in ela 2 the gene encoding neutrophil elastase and is estimated to occur in 1 in 1 million individuals worldwide treatment includes g csf and usually improves after puberty
cyclic nucleotide – gated ion channels or cng channels are ion channels that function in response to the binding of cyclic nucleotides cng channels are nonselective cation channels that are found in the membranes of various tissue and cell types and are significant in sensory transduction as well as cellular development their function can be the result of a combination of the binding of cyclic nucleotides cgmp and camp and either a depolarization or a hyperpolarization event initially discovered in the cells that make up the retina of the eye cng channels have been found in many different cell types across both the animal and the plant kingdoms cng channels have a very complex structure with various subunits and domains that play a critical role in their function cng channels are significant in the function of various sensory pathways including vision and olfaction as well as in other key cellular functions such as hormone release and chemotaxis
in combinatorial mathematics cyclic sieving is a phenomenon by which evaluating a generating function for a finite set at roots of unity counts symmetry classes of objects acted on by a cyclic group
cyclic succession is a pattern of vegetation change in which in a small number of species tend to replace each other over time in the absence of large scale disturbance observations of cyclic replacement have provided evidence against traditional clementsian views of an end state climax community with stable species compositions cyclic succession is one of several kinds of ecological succession a concept in community ecology when used narrowly ‘ cyclic succession ’ refers to processes not initiated by wholesale exogenous disturbances or long term physical changes in the environment however broader cyclic processes can also be observed in cases of secondary succession in which regular disturbances such as insect outbreaks can ‘ reset ’ an entire community to a previous stage these examples differ from the classic cases of cyclic succession discussed below in that entire species groups are exchanged as opposed to one species for another on geologic time scales climate cycles can result in cyclic vegetation changes by directly altering the physical environment
cyclic vomiting syndrome us english or cyclical vomiting syndrome uk english cvs is a chronic functional condition of unknown etiology characterised by recurring attacks of intense nausea vomiting and sometimes abdominal pain headaches or migraines cvs typically develops during childhood usually between ages 3 and 7 although it often remits during adolescence it can persist into adult life
a cycloaddition is a pericyclic chemical reaction in which two or more unsaturated molecules or parts of the same molecule combine with the formation of a cyclic adduct in which there is a net reduction of the bond multiplicity the resulting reaction is a cyclization reaction many but not all cycloadditions are concerted as a class of addition reaction cycloadditions permit carbon – carbon bond formation without the use of a nucleophile or electrophile cycloadditions can be described using two systems of notation an older but still common notation is based on the size of linear arrangements of atoms in the reactants it uses parentheses i j … where the variables are the numbers of linear atoms in each reactant the product is a cycle of size i j … in this system the standard diels alder reaction a 4 2 cycloaddition the 1 3 dipolar cycloaddition is a 3 2 cycloaddition and cyclopropanation of a carbene with an alkene a 2 1 cycloaddition a more recent iupac preferred notation uses square brackets to indicate the number of electrons rather than carbon atoms involved in the formation of the product in the i j … notation the standard diels alder reaction is a 4 2 cycloaddition the 1 3 dipolar cycloaddition is 4 2
cyclopia also cyclocephaly or synophthalmia is a rare form of holoprosencephaly and is a congenital disorder birth defect characterized by the failure of the embryonic prosencephalon to properly divide the orbits of the eye into two cavities its incidence is 1 in 16 000 in born animals and 1 in 200 in miscarried fetuses
cycloplegia is paralysis of the ciliary muscle of the eye resulting in a loss of accommodation because of the paralysis of the ciliary muscle the curvature of the lens can no longer be adjusted to focus on nearby objects this results in similar problems as those caused by presbyopia in which the lens has lost elasticity and can also no longer focus on close by objects cycloplegia with accompanying mydriasis dilation of pupil is usually due to topical application of muscarinic antagonists such as atropine and cyclopentolate
cyclosporiasis is a disease caused by infection with cyclospora cayetanensis a pathogenic protozoan transmitted by feces or feces contaminated food and water outbreaks have been reported due to contaminated fruits and vegetables it is not spread from person to person but can be a hazard for travelers as a cause of diarrhea
cyclothymia ˌsaɪkloʊˈθaɪmiə also called cyclothymic disorder is a type of chronic mood disorder widely considered to be a more chronic but milder or subthreshold form of bipolar disorder cyclothymia is characterized by numerous mood swings with periods of hypomanic symptoms that do not meet criteria for a hypomanic episode alternating with periods of mild or moderate symptoms of depression that do not meet criteria for a major depressive episode an individual with cyclothymia may feel stable at a baseline level but experience a noticeable shift to an emotional high during subthreshold hypomanic episodes of elation or euphoria with symptoms similar to those of mania but less severe and often cycle to emotional lows with moderate depressive symptoms to meet the diagnostic criteria for cyclothymia a person must experience this alternating pattern of emotional highs and lows for a period of at least two years with no more than two consecutive symptom free months for children and adolescents the duration must be at least one year while diagnosis of cyclothymia is becoming more common it is not as frequent as that of bipolar disorder diagnosis of cyclothymia entails the absence of any major depressive episode manic episode or mixed episode which would qualify the individual for diagnosis of other mood disorders when a major episode manifests after an initial diagnosis of cyclothymia the individual may qualify for a diagnosis of bipolar i or bipolar ii disorder although estimates vary greatly 15 – 50 of cases of cyclothymia later advance to the diagnostic criteria for bipolar i and or bipolar ii disorder with cyclothymic features although the emotional highs and lows of cyclothymia are less extreme than those of bipolar disorder the symptomatology longitudinal course family history and treatment response of cyclothymia are consistent with bipolar spectrum lifetime prevalence of cyclothymic disorder is 0 4 – 1 frequency appears similar in men and women though women more often seek treatment people with cyclothymia during periodic hypomania euphoria tend to feel an inflated self worth self confidence and elation often with rapid speech racing thoughts not much need to sleep increased aggression and impulsive behavior showing little regard for consequences of decisions — but may sometimes be somewhat fully or hyper productive for a period of several days at a time
cyclotropia is a form of strabismus in which compared to the correct positioning of the eyes there is a torsion of one eye or both about the eye s visual axis consequently the visual fields of the two eyes appear tilted relative to each other the corresponding latent condition – a condition in which torsion occurs only in the absence of appropriate visual stimuli – is called cyclophoria cyclotropia is often associated with other disorders of strabism can result in double vision and can cause other symptoms in particular head tilt in some cases subjective and objective cyclodeviation may result from surgery for oblique muscle disorders if the visual system cannot compensate for it cyclotropia and rotational double vision cyclodiplopia may result the role of cyclotropia in vision disorders is not always correctly identified in several cases of double vision once the underlying cyclotropia was identified the condition was solved by surgical cyclotropia correction conversely artificially causing cyclotropia in cats leads to reduced vision acuity resulting in a defect similar to strabismic amblyopia
a variant of eccrine spiradenoma which can be multiple on the scalp and can coalesce to form a turban tumour in pathology a cylindroma is a tumour with nests of cells that resemble a cylinder in cross section types include dermal eccrine cylindroma a benign tumour of the skin adenoid cystic carcinoma a malignant tumour of the salivary gland
a cyst is a closed sac having a distinct membrane and division compared to the nearby tissue hence it is a cluster of cells that have grouped together to form a sac not unlike the manner in which water molecules group together forming a bubble however the distinguishing aspect of a cyst is that the cells forming the shell of such a sac are distinctly abnormal in both appearance and behaviour when compared to all surrounding cells for that given location it may contain air fluids or semi solid material a collection of pus is called an abscess not a cyst once formed a cyst may sometimes resolve on its own when a cyst fails to resolve it may need to be removed by surgery but this will depend on what type of cyst it is and where in the body it has formed some cysts are neoplastic and are thus called cystic tumors many types are not neoplastic some are dysplastic or metaplastic pseudocysts are similar to cysts having a sac filled with fluid but lack an epithelial lining
cystadenocarcinoma is a malignant form of a cystadenoma and is a malignant neoplasm derived from glandular epithelium in which cystic accumulations of retained secretions are formed the neoplastic cells manifest varying degrees of anaplasia and invasiveness and local extension and metastases occur cystadenocarcinomas develop frequently in the ovaries where pseudomucinous and serous types are recognized similar tumor histology has also been reported in the pancreas although it is a considerably rarer entity it is the most common malignant ovarian tumor contains complex multi loculated cyst but with exuberant solid areas in places it usually presents with omental metastases which cause ascites
cystadenoma or cystoma is a type of cystic adenoma when malignant it is called cystadenocarcinoma
cystathioninuria also called cystathionase deficiency is an autosomal recessive metabolic disorder that results in an excess of cystathionine in the urine it is associated with a congenital dysfunction of the enzyme cystathionase or acquired deficiency of vitamin b 6 which is essential for the function of this enzyme the latter is usually related to an overall deficiency of all the b complex vitamins
congenital cystic eye also known as cce or cystic eyeball is an extremely rare ocular malformation where the eye fails to develop correctly in utero and is replaced by benign fluid filled tissue its incidence is unknown due to the very small number of cases reported an audit by duke elder of the medical literature from 1880 to 1963 discovered only 28 cases the term was coined in 1937 by the renowned ophthalmologist ida mann embryologically the defect is thought to occur around day 35 of gestation when the vesicle fails to invaginate dysgenesis of the vesicle later in development may result in coloboma a separate and less severe malformation of the ocular structures cce is almost always unilateral but at least 2 cases of bilateral involvement have been described patients may also present with skin appendages attached to the skin surrounding the eyes association with intracranial anomalies has been reported treatment of cce is usually by enucleation followed by insertion of an ocular implant and prosthesis
cystic fibrosis cf is a genetic disorder that affects mostly the lungs but also the pancreas liver kidneys and intestine long term issues include difficulty breathing and coughing up mucus as a result of frequent lung infections other signs and symptoms include sinus infections poor growth fatty stool clubbing of the fingers and toes and infertility in males among others different people may have different degrees of symptoms cf is inherited in an autosomal recessive manner it is caused by the presence of mutations in both copies of the gene for the cystic fibrosis transmembrane conductance regulator cftr protein those with a single working copy are carriers and otherwise mostly normal cftr is involved in production of sweat digestive fluids and mucus when cftr is not functional secretions which are usually thin instead become thick the condition is diagnosed by a sweat test and genetic testing screening of infants at birth takes place in some areas of the world no cure for cystic fibrosis is known lung infections are treated with antibiotics which may be given intravenously inhaled or by mouth sometimes the antibiotic azithromycin is used long term inhaled hypertonic saline and salbutamol may also be useful lung transplantation may be an option if lung function continues to worsen pancreatic enzyme replacement and fat soluble vitamin supplementation are important especially in the young airway clearance techniques such as chest physiotherapy have some short term benefit but long term effects are unclear the average life expectancy is between 42 and 50 years in the developed world lung problems are responsible for death in 80 of people with cystic fibrosis cf is most common among people of northern european ancestry and affects about one out of every 3 000 newborns about one in 25 people is a carrier it is least common in africans and asians it was first recognized as a specific disease by dorothy andersen in 1938 with descriptions that fit the condition occurring at least as far back as 1595 the name cystic fibrosis refers to the characteristic fibrosis and cysts that form within the pancreas
cystic fibrosis related diabetes cfrd is diabetes specifically caused by cystic fibrosis a genetic condition cystic fibrosis related diabetes mellitus cfrd develops with age and the median age at diagnosis is 21 years
a cystic hygroma also known as cystic lymphangioma and macrocystic lymphatic malformation is an often congenital multiloculated lymphatic lesion that can arise anywhere but is classically found in the left posterior triangle of the neck and armpits this is the most common form of lymphangioma it contains large cyst like cavities containing lymph a watery fluid that circulates throughout the lymphatic system microscopically cystic hygroma consists of multiple locules filled with lymph in the depth the locules are quite big but they decrease in size towards the surface cystic hygromas are benign but can be disfiguring it is a condition which usually affects children very rarely it can present in adulthood cystic hygroma is also known as lymphatic malformation currently the medical field prefers to use the term lymphatic malformation because the term cystic hygroma means water tumor lymphatic malformation is more commonly used now because it is a sponge like collection of abnormal growth that contains clear lymphatic fluid the fluid collects within the cysts or channels usually in the soft tissue cystic hygromas occur when the lymphatic vessels that make up the lymphatic system are not formed properly there are two types of lymphatic malformations they are macrocystic lymphatic malformations large cysts and microcystic small cysts a person may have only one kind of the malformation or can have a mixture of both macro and micro cysts cystic hygroma can be associated with a nuchal lymphangioma or a fetal hydrops additionally it can be associated with turner syndrome or with noonan syndrome a lethal version of this condition is known as cowchock wapner kurtz syndrome that in addition to cystic hygroma includes cleft palate and lymphedema a condition of localized edema and tissue swelling caused by a compromised lymphatic system
cystic kidney disease refers to a wide range of hereditary developmental and acquired conditions with the inclusion of neoplasms with cystic changes over 40 classifications and subtypes have been identified depending on the disease classification the presentation of disease may be from birth or much later into adult life cystic disease may involve one or both kidneys and may or may not occur in the presence of other anomalies a higher incidence of cystic kidney disease is found in the male population and prevalence increases with age renal cysts have been reported in more than 50 of patients over the age of 50 typically cysts grow up to 2 88 mm annually and cause related pain and or hemorrhage of the cystic kidney diseases the most common is polycystic kidney disease having two prevalent sub types autosomal recessive and autosomal dominant polycystic kidney disease autosomal recessive polycystic kidney disease arpkd is primarily diagnosed in infants and young children autosomal dominant polycystic kidney disease adpkd is most often diagnosed in adulthood another example of cystic kidney disease is medullary sponge kidney
a cystic nephroma also known as multilocular cystic nephroma mixed epithelial stromal tumour mest and renal epithelial stromal tumour rest is a type of rare benign kidney tumour
cystic tumour of the atrioventricular nodal region is a very rare tumour of the heart in the region of the atrioventricular node it is also known as mesothelioma of the atrioventricular node
cystica profunda is a rare disease of the gut lining it is characterized by formation of mucin cysts in the muscle layers of the gut lining and it can occur anywhere along the gastrointestinal tract when the condition occurs in the stomach it may be termed gastritis cystica profunda and in the small intestine enteritis cystica profunda when it occurs in the colon it is termed colitis cystica profunda colitis cystica profunda is benign but it may mimic a tumor when it occurs in the rectum it may be termed colitis cystica profunda or termed proctitis cystica profunda some consider this synonymous or closely related to solitary rectal ulcer syndrome a consequence of internal rectal intussusception it can have benign columnar epithelium and mucosal cysts deep to the muscularis mucosa on microscopy hence it can be mistaken for an invasive adenocarcinoma
cysticercosis is a tissue infection caused by the young form of the pork tapeworm people may have little or no symptoms for years in some cases particularly in asia solid lumps of between one and two centimetres may develop under the skin after months or years these lumps can become painful and swollen and then resolve a specific form called neurocysticercosis which affects the brain can give neurological symptoms in developing countries this is one of the most common causes of seizures cysticercosis is usually acquired by eating food or drinking water that has tapeworm eggs in it among foods uncooked vegetables are the major source the tapeworm eggs are present in the feces of a person infected with the adult worms a condition known as taeniasis taeniasis in the strict sense is a different disease and is due to eating cysts in poorly cooked pork people who live with someone with the tapeworm have a greater risk of getting cysticercosis the diagnosis can be made by aspiration of a cyst taking pictures of the brain with computer tomography ct or magnetic resonance imaging mri are most useful for the diagnosis of disease in the brain an increased number of a type of white blood cell called eosinophils in the cerebral spinal fluid and blood is also an indicator infection can be effectively prevented by personal hygiene and sanitation this includes cooking pork well proper toilets and sanitary practices and improved access to clean water treating those with taeniasis is important to prevent spread treating the disease when it does not involve the nervous system may not be required treatment of those with neurocysticercosis may be with the medications praziquantel or albendazole these may be required for long periods of time steroids for anti inflammation during treatment and anti seizure medications may also be required surgery is sometimes done to remove the cysts the pork tapeworm is particularly common in asia sub saharan africa and latin america in some areas it is believed that up to 25 of people are affected in the developed world it is very uncommon worldwide as of 2010 it caused about 1 200 deaths up from 700 in 1990 cysticercosis also affects pigs and cows but rarely causes symptoms as most do not live long enough the disease has occurred in humans throughout history it is one of the neglected tropical diseases
cysticercosis cutis is a cutaneous condition caused by taenia solium
cystinosis is a lysosomal storage disease characterized by the abnormal accumulation of the amino acid cystine it is a genetic disorder that typically follows an autosomal recessive inheritance pattern cystinosis is the most common cause of fanconi syndrome in the pediatric age group fanconi syndrome occurs when the function of cells in renal tubules are impaired leading to abnormal amounts of carbohydrates and amino acids in the urine excessive urination and low blood levels of potassium and phosphates cystinosis was the first documented genetic disease belonging to the group of lysosomal transport defect disorders it is a rare autosomal recessive disorder resulting from accumulation of free cystine in lysosomes eventually leading to intracellular crystal formation throughout the body cystinosis is caused by mutations in the ctns gene that codes for cystinosin the lysosomal membrane specific transporter for cystine intracellular metabolism of cystine as it happens with all amino acids requires its transport across the cell membrane after degradation of endocytosed protein to cystine within lysosomes it is normally transported to the cytosol but if there is a defect in the carrier protein cystine is accumulated in lysosomes as cystine is highly insoluble when its concentration in tissue lysosomes increase its solubility is immediately exceeded and crystalline precipitates are formed in almost all organs and tissues however the progression of the disease is not related to the presence of crystals in target tissues although tissue damage might depend on cystine accumulation the mechanisms of tissue damage are not fully understood increased intracellular cystine profoundly disturbs cellular oxidative metabolism and glutathione status leading to altered mitochondrial energy metabolism autophagy and apoptosis cystinosis is usually treated with cysteamine which is prescribed to decrease intralysosomal cystine accumulation however the recent discovery of new pathogenic mechanisms and the development of an animal model of the disease may open possibilities for the development of new treatment modalities to improve long term prognosis
cystinuria is an inherited autosomal recessive disease that is characterized by high concentrations of the amino acid cystine in the urine leading to the formation of cystine stones in the kidneys ureter and bladder it is a type of aminoaciduria
a cystocele ˈsɪstəsiːl sis tə seel is a medical condition that occurs when the tough fibrous wall between a woman s bladder and her vagina the pubocervical fascia is torn by childbirth allowing the bladder to herniate into the vagina urethroceles often occur with cystoceles
a cyst is a pathological epithelial lined cavity that fills with fluid or soft material and usually grows from internal pressure generated by fluid being drawn into the cavity from osmosis hydrostatic pressure the bones of the jaws the mandible and maxilla are the bones with the highest prevalence of cysts in the human body this is due to the abundant amount of epithelial remnants that can be left in the bones of the jaws the enamel of teeth is formed from ectoderm the precursor germ layer to skin and mucosa and so remnants of epithelium can be left in the bone during odontogenesis tooth development the bones of the jaws develop from embryologic processes which fuse together and ectodermal tissue may be trapped along the lines of this fusion this resting epithelium also termed cell rests is usually dormant or undergoes atrophy but when stimulated may form a cyst the reasons why resting epithelium may proliferate and undergo cystic transformation are generally unknown but inflammation is thought to be a major factor the high prevalence of tooth impactions and dental infections that occur in the bones of the jaws is also significant to explain why cysts are more common at these sites cysts that arise from tissue s that would normally develop into teeth are referred to as odontogenic cysts other cysts of the jaws are termed non odontogenic cysts non odontogenic cysts form from tissues other than those involved in tooth development and consequently may contain structures such as epithelium from the nose as the cyst grows from hydraulic pressure it causes the bone around it to resorb and may cause movement of teeth or other vital structures such as nerves and blood vessels or resorb the roots of teeth most cysts do not cause any symptoms and are discovered on routine dental radiographs some cysts may not require any treatment but if treatment is required it usually involves some minor surgery to partially or completely remove the cyst in a one or two stage procedure
cytokine release syndrome is a common immediate complication occurring with the use of anti t cell antibody infusions such as atg okt 3 and tgn 1412 but also with the cd 20 antibody rituximab severe cases are known as cytokine storms the pathogenesis is that the antigens bind to the t cell receptor activating the t cells before they are destroyed the cytokines released by the activated t cells produce a type of systemic inflammatory response similar to that found in severe infection characterised by hypotension pyrexia and rigors the patient feels very unwell as if in a high fever – indeed the cytokine release syndrome is effectively a type of non infective fever deaths due to cytokine release syndrome with okt 3 muromonab cd 3 have been reported and it can cause life threatening pulmonary edema if the patient is fluid overloaded however if treated appropriately it is usually not dangerous just extremely unpleasant for the patient the effect is greatly reduced by using low dose okt 3 e g 2 mg instead of 5 mg slow infusion instead of rapid injection intravenous administration of an anti histamine such as chlorphenamine and a corticosteroid such as hydrocortisone prior to starting the atg okt 3 infusion with further doses of anti histamine and steroid given during the infusion if necessary acetaminophen 500 mg by mouth 1 hour before infusion to prevent fever moreover it is recommended that any overhydration to be corrected before the administration of the first dose either by dialysis or with intravenous furosemide to prevent the possible development of pulmonary oedema
a cytokine storm also known as cytokine cascade and hypercytokinemia is a potentially fatal immune reaction consisting of a positive feedback loop between cytokines and white blood cells with highly elevated levels of various cytokines
cytomegalic inclusion body disease cibd is a series of signs and symptoms caused by cytomegalovirus infection toxoplasmosis or other rare infections such as herpes or rubella viruses it can produce massive calcification of the central nervous system and often the kidneys cytomegalic inclusion body disease is the most common cause of congenital abnormalities in the united states it can also cause pneumonia and other diseases in immunocompromised patients such as those with hiv aids or recipients of organ transplants
cytomegalovirus from the greek cyto cell and megalo large is a genus of viruses in the order herpesvirales in the family herpesviridae in the subfamily betaherpesvirinae humans and monkeys serve as natural hosts there are currently eight species in this genus including the type species human herpesvirus 5 hhv 5 diseases associated with hhv 5 include glandular fever and pneumonia it is typically abbreviated as cmv the species that infects humans is commonly known as human cmv hcmv or human herpesvirus 5 hhv 5 and is the most studied of all cytomegaloviruses within herpesviridae cmv belongs to the betaherpesvirinae subfamily which also includes the genera muromegalovirus and roseolovirus hhv 6 and hhv 7 it is related to other herpesviruses within the subfamilies of alphaherpesvirinae that includes herpes simplex viruses hsv 1 and 2 and varicella zoster virus vzv and the gammaherpesvirinae subfamily that includes epstein – barr virus all herpesviruses share a characteristic ability to remain latent within the body over long periods although they may be found throughout the body cmv infections are frequently associated with the salivary glands in humans and other mammals other cmv viruses are found in several mammal species but species isolated from animals differ from hcmv in terms of genomic structure and have not been reported to cause human disease
cytomegalovirus colitis also known as cmv colitis is an inflammation of the colon causesthe infection is spread by saliva urine respiratory droplets sexual contact and blood transfusions most people are exposed to the virus in their lifetime but it usually produces mild or no symptoms in healthy people however serious cmv infections can occur in people with weakened immune systems this includes patients receiving chemotherapy for cancer and patients on immune suppressing medicines following an organ transplant in rare instances more severe cmv infection involving the gi tract has been reported in people with a healthy immune system
cytomegalovirus esophagitis is a form of esophagitis associated with cytomegalovirus it is likely to present with a single deep ulcer as opposed to the multiple shallow ulcers seen in herpes esophagitis
cytomegalovirus retinitis also known as cmv retinitis is an inflammation of the retina of the eye that can lead to blindness caused by human cytomegalovirus it occurs predominantly in people whose immune system has been compromised 15 40 of those infected with aids there are different types of retinitis such as retinitis pigmentosa causes tunnel vision
cytoplasmic incompatibility ci is a phenomenon that results in sperm and eggs being unable to form viable offspring the effect arises from changes in the gamete cells caused by intracellular parasites like wolbachia which infect a wide range of insect species as the reproductive incompatibility is caused by bacteria that reside in the cytoplasm of the host cells it is referred to as cytoplasmic incompatibility in 1971 janice yen and a ralph barr of ucla demonstrated the etiologic relationship of wolbachia infection and cytoplasmic incompatibility in culex mosquitos when they found that eggs were killed when the sperm of wolbachia infected males fertilized infection free eggs
cytorrhysis refers to the permanent and irreparable damage to the cell wall after the complete collapse of a plant cell due to the loss of internal positive pressure hydraulic turgor pressure positive pressure within a plant cell is required to maintain the upright structure of the cell wall desiccation relative water content of less than or equal to 10 resulting in cellular collapse occurs when the ability of the plant cell to regulate turgor pressure is compromised due to certain environmental stressors water continues to diffuse out of the cell after the point of zero turgor pressure where internal cellular pressure is equal to the external atmospheric pressure has been reached generating negative pressure within the cell that negative pressure pulls the center of the cell inward until the cell wall can no longer withstand the strain the inward pressure causes the majority of the collapse to occur in the central region of the cell pushing the organelles within the remaining cytoplasm against the cell walls unlike plasmolysis a phenomenon that does not occur in nature the plasma membrane maintains its connections with the cell wall both during and after cellular collapse cytorrhysis of plant cells can be induced in laboratory settings if they are placed in a hypertonic solution where the size of the solutes in the solution inhibit flow through the pores in the cell wall matrix polyethylene glycol is an example of a solute with a high molecular weight that is used to induce cytorrhysis under experimental conditions environmental stressors which can lead to occurrences of cytorrhysis in a natural setting include intense drought freezing temperatures and pathogens such as the rice blast fungus magnaporthe grisea
in mathematics a càdlàg french continue à droite limite à gauche rcll “ right continuous with left limits ” or corlol continuous on the right limit on the left function is a function defined on the real numbers or a subset of them that is everywhere right continuous and has left limits everywhere càdlàg functions are important in the study of stochastic processes that admit or even require jumps unlike brownian motion which has continuous sample paths the collection of càdlàg functions on a given domain is known as skorokhod space two related terms are càglàd standing for continue à gauche limite à droite the left right reversal of càdlàg and càllàl for continue à l un limite à l ’ autre continuous on one side limit on the other side for a function which is interchangeably either càdlàg or càglàd at each point of the domain
cœur en sabot french for clog shaped heart is a radiological sign seen most commonly in patients with tetralogy of fallot a cyanotic congenital heart disease it is a radiological term to describe the following findings in the x ray the cardiac size is normal or mildly enlarged the left cardiac border shows uplifted apex outermost lower most point of the heart at the left side denoting right ventricular enlargement exaggerated cardiac waist which means that the pulmonary segment is small and concave suggesting infundibular pulmonary stenosis echocardiography has been used for confirmation and differentiation of congenital heart diseases
d glyceric acidemia a k a d glyceric aciduria is an inherited disease in the category of inborn errors of metabolism it is caused by a mutation in the gene glyctk which encodes for the enzyme glycerate kinase
d bifunctional protein deficiency officially called 17 β hydroxysteroid dehydrogenase iv deficiency is an autosomal recessive peroxisomal fatty acid oxidation disorder peroxisomal disorders are usually caused by a combination of peroxisomal assembly defects or by deficiencies of specific peroxisomal enzymes the peroxisome is an organelle in the cell similar to the lysosome that functions to detoxify the cell peroxisomes contain many different enzymes such as catalase and their main function is to neutralize free radicals and detoxify drugs such as alcohol for this reason peroxisomes are ubiquitous in the liver and kidney d bp deficiency is the most severe peroxisomal disorder often resembling zellweger syndrome characteristics of the disorder include neonatal hypotonia and seizures occurring mostly within the first month of life as well as visual and hearing impairment other symptoms include severe craniofacial disfiguration psychomotor delay and neuronal migration defects most onsets of the disorder begin in the gestational weeks of development and most affected individuals die within the first two years of life
the dash diet dietary approaches to stop hypertension is a dietary pattern promoted by the u s based national heart lung and blood institute part of the national institutes of health nih an agency of the united states department of health and human services to prevent and control hypertension the dash diet is rich in fruits vegetables whole grains and low fat dairy foods includes meat fish poultry nuts and beans and is limited in sugar sweetened foods and beverages red meat and added fats in addition to its effect on blood pressure it is designed to be a well balanced approach to eating for the general public dash is recommended by the united states department of agriculture usda as one of its ideal eating plans for all americans the dash diet is based on nih studies that examined three dietary plans and their results none of the plans were vegetarian but the dash plan incorporated more fruits and vegetables low fat or nonfat dairy beans and nuts than the others studied the dash diet reduced systolic blood pressure by 6 mm hg and diastolic blood pressure by 3 mm hg in patients with high normal blood pressure formerly called pre hypertension those with hypertension dropped by 11 and 6 mm hg respectively these changes in blood pressure occurred with no changes in body weight the dash dietary pattern is adjusted based on daily caloric intake ranging from 1 600 to 3 100 dietary calories the dash diet was further tested and developed in the optimal macronutrient intake trial for heart health omniheart diet the dash and dash sodium trials demonstrated that a carbohydrate rich diet that emphasizes fruits vegetables and low fat dairy products and that is reduced in saturated fat total fat and cholesterol substantially lowered blood pressure and low density lipoprotein cholesterol omniheart demonstrated that partial replacement of carbohydrate with either protein about half from plant sources or with unsaturated fat mostly monounsaturated fat can further reduce blood pressure low density lipoprotein cholesterol and coronary heart disease risk in january 2016 dash was named the number 1 for best diets overall and for healthy eating tied number 2 for diabetes and ranked number 3 for heart health out of 38 diets tested in the us news world report s annual “ best diets ” rankings
dlco or tlco diffusing capacity or transfer factor of the lung for carbon monoxide co is the extent to which oxygen passes from the air sacs of the lungs into the blood commonly it refers to the test used to determine this parameter it was introduced in 1909
dna damage is an alteration in the chemical structure of dna such as a break in a strand of dna a base missing from the backbone of dna or a chemically changed base such as 8 ohdg damage to dna that occurs naturally can result from metabolic or hydrolytic processes metabolism releases compounds that damage dna including reactive oxygen species reactive nitrogen species reactive carbonyl species lipid peroxidation products and alkylating agents among others while hydrolysis cleaves chemical bonds in dna naturally occurring oxidative dna damages arise at least 10 000 times per cell per day in humans and 50 000 times or more per cell per day in rats as documented below dna damage is distinctly different from mutation although both are types of error in dna dna damage is an abnormal chemical structure in dna while a mutation is a change in the sequence of standard base pairs dna damage and mutation have different biological consequences while most dna damages can undergo dna repair such repair is not 100 efficient un repaired dna damages accumulate in non replicating cells such as cells in the brains or muscles of adult mammals and can cause aging also see dna damage theory of aging in replicating cells such as cells lining the colon errors occur upon replication of past damages in the template strand of dna or during repair of dna damages these errors can give rise to mutations or epigenetic alterations both of these types of alteration can be replicated and passed on to subsequent cell generations these alterations can change gene function or regulation of gene expression and possibly contribute to progression to cancer
the dna damage theory of aging proposes that aging is a consequence of unrepaired accumulation of naturally occurring dna damages damage in this context is a dna alteration that has an abnormal structure although both mitochondrial and nuclear dna damage can contribute to aging nuclear dna is the main subject of this analysis nuclear dna damage can contribute to aging either indirectly by increasing apoptosis or cellular senescence or directly by increasing cell dysfunction in humans and other mammals dna damage occurs frequently and dna repair processes have evolved to compensate in estimates made for mice on average approximately 1 500 to 7 000 dna lesions occur per hour in each mouse cell or about 36 000 to 160 000 per cell per day in any cell some dna damage may remain despite the action of repair processes the accumulation of unrepaired dna damage is more prevalent in certain types of cells particularly in non replicating or slowly replicating cells such as cells in the brain skeletal and cardiac muscle
dna fragmentation is the separation or breaking of dna strands into pieces it can be done intentionally by laboratory personnel or by cells or can occur spontaneously spontaneous or accidental dna fragmentation is fragmentation that gradually accumulates in a cell it can be measured by e g the comet assay the degree of dna fragmentation can predict outcomes for in vitro fertilization ivf and its expansion intracytoplasmic sperm injection icsi the sperm chromatin dispersion test scd and tunel assay are both effective in detecting sperm dna damage using bright field microscopy the scd test appears to be more sensitive than the tunel assay its main units of measurement is the dna fragmentation index dfi a dfi of 20 or more significantly reduces the success rates after icsi dna fragmentation was first documented by williamson in 1970 when he observed discrete oligomeric fragments occurring during cell death in primary neonatal liver cultures he described the cytoplasmic dna isolated from mouse liver cells after culture as characterized by dna fragments with a molecular weight consisting of multiples of 135 kda this finding was consistent with the hypothesis that these dna fragments were a specific degradation product of nuclear dna
a dna repair deficiency disorder is a medical condition due to reduced functionality of dna repair dna repair defects can cause both an accelerated aging disease and an increased risk of cancer
door deafness onychdystrophy osteodystrophy and mental retardation syndrome is a genetic disease which is inherited in an autosomal recessive fashion door syndrome is characterized by mental retardation sensorineural deafness abnormal nails and phalanges of the hands and feet and variable seizures a similar deafness onychodystrophy syndrome is transmitted as an autosomal dominant trait and has no mental retardation some authors have proposed that it may be the same as eronen syndrome but since both disorders are extremely rare it is hard to make a determination
dt manie is a linguistical problem in dutch spelling created by the first official modern dutch spelling rules published in 1954 for the netherlands and for flanders
the time correction dut 1 sometimes also written dut is the difference between universal time ut 1 which is defined by earth s rotation and coordinated universal time utc which is defined by a network of precision atomic clocks dut 1 ut 1 − utc utc is maintained via leap seconds such that dut 1 remains within the range − 0 9 s dut 1 0 9 s the reason for this correction is partly that the rate of rotation of the earth is not constant due to tidal braking and the redistribution of mass within the earth including its oceans and atmosphere and partly because the si second as now used for utc was already when adopted a little shorter than the current value of the second of mean solar time forecast values of dut 1 are published by iers bulletin a weekly updated values of dut 1 with 0 1 s precision are broadcast by several time signal services including wwv and msf these services transmit one pulse per second of some sort to represent positive dut 1 values from 0 1 to 0 8 seconds the pulses sent during seconds 1 through 8 are emphasized in some way generally by transmitting a double pulse the number of emphasized pulses gives the value of dut 1 negative dut 1 values from − 0 1 to − 0 8 seconds are similarly represented by emphasizing pulses 9 through 16 for example a dut 1 value of − 0 4 would be transmitted by emphasizing pulses 9 through 12 the russian time signal rwm transmits an additional correction dut 1 in 0 02 s increments positive values of dut 1 from 0 02 to 0 08 s are encoded by emphasizing pulses 21 through 24 negative values are encoded by emphasizing pulses 31 through 34 the actual value of dut 1 is approximated by the sum of the transmitted dut 1 dut 1 the longwave rbu time signal also transmits dut 1
da costa s syndrome which was colloquially known as soldier s heart is a syndrome with a set of symptoms that are similar to those of heart disease though a physical examination does not reveal any physiological abnormalities in modern times da costa s syndrome is considered the manifestation of an anxiety disorder and treatment is primarily behavioral involving modifications to lifestyle and exercise the condition was named after jacob mendes da costa who investigated and described the disorder during the american civil war it is also variously known as cardiac neurosis chronic asthenia effort syndrome functional cardiovascular disease neurocirculatory asthenia primary neurasthenia subacute asthenia and irritable heart
dacryoadenitis is inflammation of the lacrimal glands the tear producing glands
dacryocystitis is an infection of the lacrimal sac secondary to obstruction of the nasolacrimal duct at the junction of lacrimal sac the term derives from the greek dákryon tear cysta sac and itis inflammation it causes pain redness and swelling over the inner aspect of the lower eyelid and epiphora when nasolacrimal duct obstruction is secondary to a congenital barrier it is referred to as dacrocystocele it is most commonly caused by staphylococcus aureus and streptococcus pneumoniae the most common complication is corneal ulceration frequently in association with s pneumoniae the mainstays of treatment are oral antibiotics warm compresses and relief of nasolacrimal duct obstruction by dacryocystorhinostomy
dactylitis or sausage digit is inflammation of an entire digit a finger or toe and can be painful the word dactyl comes from the greek word daktylos meaning finger in its medical term it refers to both the fingers and the toes
daentl townsend siegel syndrome is a very rare disorder characterized by blue sclerae kidney malfunction thin skin and hydrocephalus it was first identified by d l daentl et al in 1978 daentl townsend siegel syndrome is also known as hydrocephalus blue sclera nephropathy and familial nephrosis hydrocephalus thin skin blue sclerae syndrome
the dag hammarskjöld invert is a 4 cent value postage stamp error issued on 23 october 1962 by the united states postal service then known as the post office department one year after the death of dag hammarskjöld secretary general of the united nations in an airplane crash the stamp showing the yellow background inverted relative to the image and text is also known as the day s folly after postmaster general j edward day who ordered the intentional reprinting of the yellow invert commenting the post office department is not running a jackpot operation the stamp reprint was in effect a deliberate error produced by the post office department to avoid creating a rarity it was decided to reprint 40 million of the inverted stamps after the discovery of the error so there would be no rarity factor in the inverted stamp and to prevent people profiting from the postal service s mistake the reprints were issued to the public on 16 november and described as a special printing the black brown and yellow commemorative stamp with yellow background correctly printed has a scott catalogue number of 1203 but the inverted error is numbered 1204 the catalogue value of the invert is worth little more than the normal the stamp printed on giori press in plates of 200 was designed by herbert sanborn and engraved by c a brooks 121 440 000 normal stamps were printed and 40 270 000 of the inverted reprint were produced it has not been recorded how many original invert stamps were produced and it is virtually impossible to tell a reprint from an original unless it has a clear early date but an invert error on a first day cover proving that stamp was from the original printing and not from the reprint was sold in 2005 for us 3 500 the finder of the discovery sheet a new jersey jeweler named leonard sherman obtained a court injunction against the reprinting but it came too late to stop production he did however receive an affidavit from the then post office department that his was the original sheet in 1987 sherman donated his sheet to the american philatelic society because the reprint dashed his hopes of owning a valuable stamp error mad magazine later commemorated the affair by printing a parody stamp that looked similar to the real issue but put a crying sherman in place of hammarskjold with money flying away from him
dahlberg borer newcomer syndrome is a rare autosomal x linked recessive genetic condition characterized by a prolapse of the bicuspid valve progressive kidney failure congenital lymphedema hypoparathyroidism and very short end bones of fingers treatment for this condition is based on its symptoms these treatments may include manual lymphatic drainage consumption of beta blockers or anticoagulants for the bicuspid valve prolapse and vitamin d or calcium carbonate tablets for the hypoparathyroidism this condition is also known as lymphedema hypoparathyroidism syndrome hypoparathyroidism lymphedema syndrome and simply dahlberg syndrome
daily light integral dli is the amount of par received each day as a function of light intensity instantaneous light μmol · m − 2 · s − 1 and duration day it is expressed as moles of light mol per square meter m − 2 per day d − 1 or mol · m − 2 · d − 1 moles per day the daily light integral dli is a measure of the amount of light received in a single day in a particular area for example the number of moles of photosynthetically active radiation par photons received during a single day in a square meter or mol · m − 2 · d − 1 another example is the total solar radiation received during a single day in a square meter or w · m − 2 depending on the application or research question the time integral of incident light may be a more useful tool than the instantaneous incident light dli varies depending on latitude time of year and cloud cover and ranges from 5 60 mol · m − 2 · d − 1 in the united states for par in greenhouses or growth chambers dli values are typically much lower which can affect the shoot root ratio morphology and the timing of flowering on a sunny winter day in the middle latitudes a plant receives about 9 moles day if it is cloudy the dli drops to 3 moles day in the summer the dli for a sunny day is about 26 moles day and 12 moles day for a cloudy day each type of plant has a different dli range for optimal growth dli is directly correlated with plant quality and a minimum amount of light is required for marketable plants measuring dli over a growing season and comparing it to results can help a grower decide which varieties work for his or her location example calculation dli mol m 2 day average light intensity μmol m 2 s · time in seconds 1 000 000 dli mol m 2 day par · h · 3600 1 000 000 see also daily ppf can be calculated directly from the instantaneous ppf from the following equation μmol m − 2 s − 1 multiplied by 86 400 and divided by 106 mol m − 2 d − 1 so 1 μmol m − 2 s − 1 0 0864 mol m − 2 d − 1 with continuous light and 2100 μmol m − 2 s − 1 90 72 mol m − 2 d − 1 with 12 hours light
the dakin oxidation or dakin reaction is an organic redox reaction in which an ortho or para hydroxylated phenyl aldehyde 2 hydroxybenzaldehyde or 4 hydroxybenzaldehyde or ketone reacts with hydrogen peroxide in base to form a benzenediol and a carboxylate overall the carbonyl group is oxidized and the hydrogen peroxide is reduced the dakin oxidation which is closely related to the baeyer villiger oxidation is not to be confused with the dakin west reaction though both are named after henry drysdale dakin
the dakin – west reaction is a chemical reaction that transforms an amino acid into a keto amide using an acid anhydride and a base typically pyridine it is named for henry drysdale dakin 1880 – 1952 and randolph west 1890 – 1949 of special note the keto amide product is always racemic however in 2016 schreiner and coworkers reported the first asymmetric variant of this reaction the dakin – west reaction with pyridine as a base and solvent refluxing conditions are required however with the addition of 4 dimethylaminopyridine dmap as a catalyst the reaction can take place at room temperature with some acids this reaction can take place even in the absence of an α amino group this reaction should not be confused with the dakin reaction
structural dampness is the presence of unwanted moisture in the structure of a building either the result of intrusion from outside or condensation from within the structure a high proportion of damp problems in buildings are caused by condensation rain penetration or rising damp
damping capacity is the ability of a material to absorb energy by converting mechanical energy into heat
damping off or damping off is a horticultural disease or condition caused by a number of different pathogens that kill or weaken seeds or seedlings before or after they germinate it is most prevalent in wet and cool conditions
dancing mania also known as dancing plague choreomania st john s dance and historically st vitus dance was a social phenomenon that occurred primarily in mainland europe between the 14 th and 17 th centuries it involved groups of people dancing erratically sometimes thousands at a time the mania affected men women and children who danced until they collapsed from exhaustion one of the first major outbreaks was in aachen in the holy roman empire in 1374 and it quickly spread throughout europe one particularly notable outbreak occurred in strasbourg in 1518 also in the holy roman empire affecting thousands of people across several centuries dancing mania was not an isolated event and was well documented in contemporary reports it was nevertheless poorly understood and remedies were based on guesswork generally musicians accompanied dancers to help ward off the mania but this tactic sometimes backfired by encouraging more to join in there is no consensus among modern day scholars as to the cause of dancing mania the several theories proposed range from religious cults being behind the processions to people dancing to relieve themselves of stress and put the poverty of the period out of their minds it is however thought to have been a mass psychogenic illness in which the occurrence of similar physical symptoms with no known physical cause affect a large group of people as a form of social influence
dandruff is the shedding of dead skin cells from the scalp as skin cells die a small amount of flaking is normal about 487 000 cells cm 2 get released normally after detergent treatment some people however experience an unusually large amount of flaking either chronically or as a result of certain triggers up to 800 000 cells cm 2 which can also be accompanied by redness and irritation dandruff is a common scalp disorder affecting almost half of the population at the post pubertal age and of any sex and ethnicity it often causes itching it has been well established that keratinocytes play a key role in the expression and generation of immunological reactions during dandruff formation the severity of dandruff may fluctuate with season as it often worsens in winter dandruff is rare before puberty peaks in the teens and early twenties and declines with age thereafter most cases of dandruff can be easily treated with specialized shampoos there is however no true cure those affected by dandruff find that it can cause social or self esteem problems indicating treatment for both psychological and physiological reasons
dandy – walker syndrome dws is a rare group of congenital human brain malformations there are three subtypes which affect multiple organs to varying degrees but the fundamental abnormalities involve the cerebellum which controls muscle coordination the adjacent fourth ventricle is often affected which can alter the flow of cerebrospinal fluid increase intracranial pressure and lead to multiple other brain function problems the degree of disability varies but is typically lifelong treatment may involve physical therapy special education or surgical placement of a cerebral shunt it is named for walter dandy and arthur earl walker
the dangling else is a problem in computer programming in which an optional else clause in an if – then – else statement results in nested conditionals being ambiguous formally the reference context free grammar of the language is ambiguous meaning there is more than one correct parse tree in many programming languages one may write conditionally executed code in two forms the if then form and the if then else form – the else clause is optional if a then sif b then s 1 else s 2 this gives rise to an ambiguity in interpretation when there are nested statements specifically whenever an if then form appears as s 1 in an if then else form if a then if b then s else s 2 in this example s is unambiguously executed when a is true and b is true but one may interpret s 2 as being executed when a is false thus attaching the else to the first if or when a is true and b is false thus attaching the else to the second if in other words one may see the previous statement as either of the following expressions if a then if b then s else s 2 orif a then if b then s else s 2 the dangling else problem dates to algol 60 and has been resolved in various ways in subsequent languages in lr parsers the dangling else is the archetypal example of a shift reduce conflict
the danheiser annulation or danheiser tms cyclopentene annulation is an organic reaction of an α β unsaturated ketone and a trialkylsilylallene e g trimethylsilyl or triisopropylsilyl in the presence of a lewis acid to give a trialkylsilylcyclopentene in a regiocontrolled annulation file danheiserannulation 03 png
the danheiser benzannulation is a chemical reaction used in organic chemistry to generate highly substituted phenols in a single step it is named after its inventor dr rick danheiser
danon disease or glycogen storage disease type iib is a metabolic disorder danon disease is an x linked lysosomal and glycogen storage disorder associated with hypertrophic cardiomyopathy skeletal muscle weakness and intellectual disability
darier s disease dar also known as darier disease darier – white disease dyskeratosis follicularis and keratosis follicularis is an autosomal dominant disorder discovered by french dermatologist ferdinand jean darier darier s is characterized by dark crusty patches on the skin sometimes containing pus the crusty patches are also known as keratotic papules keratosis follicularis or dyskeratosis follicularis mild forms of the disease are the most common consisting solely of skin rashes that flare up under certain conditions such as high humidity high stress or tight fitting clothes even in mild forms short stature combined with poorly formed fingernails containing vertical striations are diagnostic
the darién gap spanish región del darién or tapón del darién is a break in the pan american highway consisting of a large swath of undeveloped swampland and forest within panama s darién province in central america and the northern portion of colombia s chocó department in south america it measures just over 160 km 99 mi long and about 50 km 31 mi wide roadbuilding through this area is expensive and the environmental cost is high political consensus in favor of road construction has not emerged consequently there is no road connection through the darién gap connecting north america with south america and it is the missing link of the pan american highway the geography of the darién gap on the colombian side is dominated primarily by the river delta of the atrato river which creates a flat marshland at least 80 km 50 mi wide half of this being swampland the serranía del baudó range extends along colombia s pacific coast and extends into panama the panamanian side in sharp contrast is a mountainous rainforest with terrain reaching from 60 m 200 ft in the valley floors to 1 845 m 6 053 ft at the tallest peak cerro tacarcuna in the serranía del darién
in electronics industry dark silicon is the amount of circuitry of an integrated circuit that cannot be powered on at the nominal operating voltage for a given thermal design power tdp constraint this is a challenge in the era of nanometer semiconductor nodes where transistor scaling and voltage scaling are no longer in line with each other resulting in the failure of dennard scaling this discontinuation of dennard scaling has led to sharp increases in power densities that hamper powering on all the transistors simultaneously at the nominal voltage while keeping the chip temperature in the safe operating range according to recent studies researchers from different groups have projected that at 8 nm technology nodes the amount of dark silicon may reach up to 50 80 depending upon the processor architecture cooling technology and application workloads dark silicon may be unavoidable even in server workloads with abundance of inherent client request level parallelism
dartitis pronounced dart eye tis is a condition which can affect darts players and severely damage their performance it can be compared to the yips an expression used to describe apparent loss of fine motor skills without any explanation the term is used in reference to players who struggle with some kind of psychological problem with their technique and or release of their darts the most famous case of dartitis was in 1986 when five times world champion eric bristow revealed he was having problems with the release of his darts bristow managed to make a partial recovery from the condition and even managed to regain the number one position in the world rankings
darwin s tubercle or auricular tubercle is a congenital ear condition which often presents as a thickening on the helix at the junction of the upper and middle thirds
a darwinian puzzle is a trait that appears to reduce the fitness of individuals that possess it such traits attract the attention of evolutionary biologists several human traits pose challenges to evolutionary thinking as they are relatively prevalent but are associated with lower reproductive success through reduced fertility and or longevity some of the classic examples include left handedness menopause and mental disorders these traits are also found in animals a peacock shows an example of a trait that may reduce its fitness the bigger the tail the easier it is seen by predators and it also may hinder the movement of the peacock darwin in fact solved this puzzle by explaining the peacock s tail as evidence of sexual selection a bigger tail confers evolutionary fitness on the male by allowing it to attract more females than other males with shorter tails the phrase darwinian puzzle itself is rare and of unclear origin it s typically talked about in the context of animal behavior
the darzens reaction also known as the darzens condensation or glycidic ester condensation is the chemical reaction of a ketone or aldehyde with an α haloester in the presence of base to form an α β epoxy ester also called a glycidic ester this reaction was discovered by the organic chemist auguste george darzens in 1904
data administration or data resource management is an organizational function working in the areas of information systems and computer science that plans organizes describes and controls data resources data resources are usually as stored in databases under a database management system or other software such as electronic spreadsheets in many smaller organizations data administration is performed occasionally or is a small component of the database administrator ’ s work in the context of information systems development data administration ideally begins at system conception ensuring there is a data dictionary to help maintain consistency avoid redundancy and model the database so as to make it logical and usable by means of data modeling including database normalization techniques
data center predictive modeling dcpm is the ability to forecast the performance of a data center into the future be it its energy use energy efficiency performance of the myriad pieces of equipment even cost an important part of forecasting data center performance is the use of computational fluid dynamics cfd to quantify the airflow and temperatures that would occur if physical changes were made to the data center space the use of cfd moves dcpm from a probabilistic type of forecasting to a physics based one the term dcpm has been in use since june 2011 and was adopted by romonet to differentiate dcpm from data center infrastructure management dcim which only tracks the present performance of the elements of a data center another example of the same technology was presented in russia by institute of applied mathematical research karelian research centre russian academy of sciences the technology is developed since 2011 under support of fasie and rfbr
data literacy is the ability to read create and communicate data as information and has been formally described in varying ways discussion of the skills inherent to data literacy and possible instructional methods have emerged as data collection becomes routinized and talk of data analysis and big data has become commonplace in the news business government and society in countries across the world
data loss is an error condition in information systems in which information is destroyed by failures or neglect in storage transmission or processing information systems implement backup and disaster recovery equipment and processes to prevent data loss or restore lost data data loss is distinguished from data unavailability which may arise from a network outage although the two have substantially similar consequences for users data unavailability is temporary while data loss may be permanent data loss is also distinct from data breach incident where data falls into the wrong hands although the term data loss has been used in those incidents
in software engineering the data mapper pattern is an architectural pattern it was named by martin fowler in his 2003 book patterns of enterprise application architecture the interface of an object conforming to this pattern would include functions such as create read update and delete that operate on objects that represent domain entity types in a data store a data mapper is a data access layer that performs bidirectional transfer of data between a persistent data store often a relational database and an in memory data representation the domain layer the goal of the pattern is to keep the in memory representation and the persistent data store independent of each other and the data mapper itself the layer is composed of one or more mappers or data access objects performing the data transfer mapper implementations vary in scope generic mappers will handle many different domain entity types dedicated mappers will handle one or a few
data mining is an interdisciplinary subfield of computer science it is the computational process of discovering patterns in large data sets involving methods at the intersection of artificial intelligence machine learning statistics and database systems the overall goal of the data mining process is to extract information from a data set and transform it into an understandable structure for further use aside from the raw analysis step it involves database and data management aspects data pre processing model and inference considerations interestingness metrics complexity considerations post processing of discovered structures visualization and online updating data mining is the analysis step of the knowledge discovery in databases process or kdd the term is a misnomer because the goal is the extraction of patterns and knowledge from large amounts of data not the extraction mining of data itself it also is a buzzword and is frequently applied to any form of large scale data or information processing collection extraction warehousing analysis and statistics as well as any application of computer decision support system including artificial intelligence machine learning and business intelligence the book data mining practical machine learning tools and techniques with java which covers mostly machine learning material was originally to be named just practical machine learning and the term data mining was only added for marketing reasons often the more general terms large scale data analysis and analytics – or when referring to actual methods artificial intelligence and machine learning – are more appropriate the actual data mining task is the automatic or semi automatic analysis of large quantities of data to extract previously unknown interesting patterns such as groups of data records cluster analysis unusual records anomaly detection and dependencies association rule mining this usually involves using database techniques such as spatial indices these patterns can then be seen as a kind of summary of the input data and may be used in further analysis or for example in machine learning and predictive analytics for example the data mining step might identify multiple groups in the data which can then be used to obtain more accurate prediction results by a decision support system neither the data collection data preparation nor result interpretation and reporting is part of the data mining step but do belong to the overall kdd process as additional steps the related terms data dredging data fishing and data snooping refer to the use of data mining methods to sample parts of a larger population data set that are or may be too small for reliable statistical inferences to be made about the validity of any patterns discovered these methods can however be used in creating new hypotheses to test against the larger data populations
data theft is a growing phenomenon primarily caused by system administrators and office workers with access to technology such as database servers desktop computers and a growing list of hand held devices capable of storing digital information such as usb flash drives ipods and even digital cameras since employees often spend a considerable amount of time developing contacts and confidential and copyrighted information for the company they work for they may feel they have some right to the information and are inclined to copy and or delete part of it when they leave the company or misuse it while they are still in employment alternatively an employee may choose to deliberately abuse trusted access to information for the purpose of exposing misconduct by the employer from the perspective of the society such an act of whistleblowing can be seen as positive and is in certain situations protected by law in some jurisdictions such as the usa while most organizations have implemented firewalls and intrusion detection systems very few take into account the threat from the average employee that copies proprietary data for personal gain or use by another company a common scenario is where a sales person makes a copy of the contact database for use in their next job typically this is a clear violation of their terms of employment notable acts of data theft by a self proclaimed whistleblower have been done by chelsea manning edward snowden and hervé falciani
data thinking is the generic mental pattern observed during the processes of picking a subject to start with identifying its parts or components organizing and describing them in an informative fashion that is relevant to what motivated and initiated the whole processes the term was created by mario faria and rogerio panigassi in 2013 when they were writing a book about data science data analytics data management and how data practitioners were able to achieve their goals mario faria is one of the first chief data officers in the world
database administration is the function of managing and maintaining database management systems dbms software mainstream dbms software such as oracle ibm db 2 and microsoft sql server need ongoing management as such corporations that use dbms software often hire specialized it information technology personnel called database administrators or dbas
in linguistics dative shift is a pattern in which the subcategorization of a verb can take on two alternating forms in the oblique dative od form the verb takes a noun phrase np and a prepositional phrase pp the second of which is not an argument john gave np a book pp to mary in the double object construction doc form the verb takes two noun phrases both of which are arguments john gave np mary np a book
david after dentist is an internet phenomenon which started when david devore jr s father posted a video on the internet of his reaction to anesthesia after he had been given oral surgery as of 3 march 2016 it has been viewed over 132 million times on youtube
the electromagnetic dawn chorus is a phenomenon that occurs most often at or shortly after dawn local time with the proper radio equipment dawn chorus can be converted to sounds that resemble birds dawn chorus by coincidence the electromagnetic dawn chorus is believed to be generated by a doppler shifted cyclotron interaction between anisotropic distributions of energetic 40 kev electrons and ambient background vlf noise these energetic electrons are generally injected into the inner magnetosphere at the onset of the substorm expansion phase dawn choruses occur more frequently during magnetic storms this phenomenon also occurs during aurorae when it is termed an auroral chorus
the dawn phenomenon sometimes called the dawn effect is an early morning usually between 2 a m and 8 a m increase in blood sugar glucose relevant to people with diabetes it is different from chronic somogyi rebound in that dawn phenomenon is not associated with nocturnal hypoglycemia the dawn phenomenon can be managed in many patients by avoiding carbohydrate intake at bedtime adjusting the dosage of medication or insulin switching to a different medication or by using an insulin pump to administer extra insulin during early morning hours in most of the cases there is no need to change insulin dosing of patients who encounter the dawn phenomenon
degrazia gallery in the sun historic district is the artistic manifestation and architecture constructed by ettore degrazia the property is a series of buildings scattered throughout a natural desert setting built in tucson near the intersection of swan road and skyline the property is now a museum open to the public construction began in 1951 with the open air mission in the sun followed by a series of other expressionistic adobe buildings the gallery museum was constructed in 1965 with details including cactus flooring exposed wood beams rafters and unique artistic finishes the gallery replaced the first degrazia building constructed in 1944 on the corner of prince and campbell road artists and friends who spent time at the new gallery included thomas hart benton olaf wieghorst jack van ryder pete martinez and ross santee in 2006 the 10 acre 40 000 m 2 property now a museum of degrazia s work was listed on the national register of historic places
the demayo reaction is a photochemical reaction in which the enol of a 1 3 diketone reacts with an alkene or another species with a c c bond and the resulting cyclobutane ring undergoes a retro aldol reaction to yield a 1 5 diketone the demayo reaction the net effect is to add the two carbon atoms in the c c double bond between the two carbonyl groups of the diketone it is thus useful in syntheses both as a relatively selective way to join two parts of a molecule and as a way to apply the more developed chemistry of 1 3 diketone synthesis to 1 5 diketones the first part is a 2 2 cycloaddition the ensuing retro aldol cleavage is favored by the relative instability of the cyclobutane ring
desanctis – cacchione syndrome is an extremely rare disorder characterized by the skin and eye symptoms of xeroderma pigmentosum xp occurring in association with microcephaly progressive mental retardation retarded growth and sexual development deafness choreoathetosis ataxia and quadriparesis
de barsy syndrome is a rare autosomal recessive genetic disorder symptoms include cutis laxa loose hanging skin as well as other eye musculoskeletal and neurological abnormalities it is usually progressive manifesting side effects that can include clouded corneas cataracts short stature dystonia or progeria premature aging it was first described in 1967 by de barsy et al and as of 2011 there have been 27 cases reported worldwide the genes that cause de barsy syndrome have not been identified yet although several studies have narrowed down the symptoms cause a study by reversade et al has shown that a mutation in pycr 1 the genetic sequence that codes for mitochondrial enzymes that break down proline are prevalent in cases of autosomal recessive cutis laxa arcl a condition very similar to de barsy syndrome a study by leao teles et al has shown that de barsy syndrome may be related to mutations in atp 6 v 0 a 2 gene known as atp 6 v 0 a 2 cdg by the new naming system alternative names for de barsy syndrome include corneal clouding cutis laxa mental retardation cutis laxa growth deficiency syndrome de barsy – moens – diercks syndrome and progeroid syndrome of de barsy
de garengeot s hernia is a rare subtype of an incarcerated femoral hernia this eponym may be used to describe the incarceration of the vermiform appendix within a femoral hernia akopian and alexander named this hernia after the 18 th century parisian surgeon rene jacques croissant de garengeot he is quoted in the surgical literature as the first to describe this situation in 1731 although the surgeon s full last name is croissant de garengeot for linguistic convenience it has been suggested to abbreviate this eponym to de garengeot similar as with the situation of an amyand s hernia the true nature of the incarcerated tissue is rarely diagnosed preoperatively patients present clinically similar to other incarcerated femoral herniae treatment consists of an appendicectomy and hernia repair laparoscopic options are described
de musset s sign is a condition in which there is rhythmic nodding or bobbing of the head in synchrony with the beating of the heart in general as a result of aortic insufficiency whereby blood from the aorta regurgitates into the left ventricle due to a defect in the aortic valve the nodding is an indication that the systolic pulse is being felt by the patient because of the increased pulse pressure resulting from the aortic insufficiency the condition was named after the french poet alfred de musset
de quervain s thyroiditis can also be known as subacute granulomatous thyroiditis or giant cell thyroiditis males and females of all ages may be affected it is a member of the group of thyroiditis conditions known as resolving thyroiditis
de quervain syndrome french pronunciation ​ də kɛʁvɛ̃ also known as blackberry thumb texting thumb gamer s thumb washerwoman s sprain radial styloid tenosynovitis de quervain disease de quervain s tenosynovitis de quervain s stenosing tenosynovitis mother s wrist or mommy thumb is a tenosynovitis of the sheath or tunnel that surrounds two tendons that control movement of the thumb
de vivo disease is an autosomal dominant developmental disorder associated with a deficiency of glut 1 also known as glucose transporter type 1 deficiency syndrome glut 1 ds
in discrete time control theory the dead beat control problem consists of finding what input signal must be applied to a system in order to bring the output to the steady state in the smallest number of time steps for an nth order linear system it can be shown that this minimum number of steps will be at most n depending on the initial condition provided that the system is null controllable that it can be brought to state zero by some input the solution is to apply feedback such that all poles of the closed loop transfer function are at the origin of the z plane for more information about transfer functions and the z plane see z transform therefore the linear case is easy to solve by extension a closed loop transfer function which has all poles of the transfer function at the origin is sometimes called a dead beat transfer function for nonlinear systems dead beat control is an open research problem see nesic reference below dead beat controllers are often used in process control due to their good dynamic properties they are a classical feedback controller where the control gains are set using a table based on the plant system order and normalized natural frequency the deadbeat response has the following characteristics 1 zero steady state error 2 minimum rise time 3 minimum settling time 4 less than 2 overshoot undershoot 5 very high control signal output
the dead rabbits riot was a two day civil disturbance in new york city resulting from what was originally a small scale street fight between members of the dead rabbits and the bowery boys into a citywide gang war which lasted from july 4 – 5 1857 taking advantage of the disorganized state of the city s police force brought about by the conflict between the municipal and metropolitan police the fighting would spiral into widespread looting and damage of property by gangsters and other criminals from all parts of the city it is estimated that between 800 and 1 000 gang members took part in the riots along with several hundred others who used the disturbance to loot the bowery area it was the largest disturbance since the astor place riot in 1849 and the biggest scene of gang violence unsurpassed until the new york draft riots of 1863 order was restored only by the new york state militia supported by detachments of city police under major general charles w sandford
dead arm sometimes grape canker is a disease of grapes caused by a deep seated wood rot of the arms or trunk of the grapevine as the disease progresses over several years one or more arms may die hence the name deadarm eventually the whole vine will die in the 1970 s dead arm was identified as really being two diseases caused by two different fungi eutypa lata and phomopsis viticola syn cryptosporella viticola
in poker dead money is the amount of money in the pot other than the equal amounts bet by active remaining players in that pot examples of dead money include money contributed to the pot by players who have folded a dead blind posted by a player returning to a game after missing blinds or an odd chip left in the pot from a previous deal for example eight players each ante 1 one player opens for 2 and gets two callers making the pot total 14 three players are now in the pot having contributed 3 each for 9 live money the remaining 5 representing the antes of the players who folded is dead money the amount of dead money in a pot affects the pot odds of plays or rules of thumb that are based on the number of players the term dead money is also used in a derogatory sense to refer to money put in the pot by players who are still legally eligible to win it but who are unlikely to do so because they are unskilled increasing the expected return of other players this can also be applied to the player himself let s invite john every week he s dead money the term dead money also applies in tournaments when many casual players enter events with virtually no chance of winning
in economics a deadweight loss also known as excess burden or allocative inefficiency is a loss of economic efficiency that can occur when equilibrium for a good or service is not achieved or is not achievable causes of deadweight loss can include monopoly pricing in the case of artificial scarcity externalities taxes or subsidies and binding price ceilings or floors including minimum wages the term deadweight loss may also be referred to as the excess burden of monopoly or taxation
deaf blindness is the condition of little or no useful sight and little or no useful hearing educationally individuals are considered to be deaf blind when the combination of their hearing and sight loss causes such severe communication and other developmental and educational needs that they require significant and unique adaptations in their educational programs helen keller was one such individual
deamidation is a chemical reaction in which an amide functional group is removed from an organic compound in biochemistry the reaction is important in the degradation of proteins because it damages the amide containing side chains of the amino acids asparagine and glutamine in the biochemical deamidation reaction the side chain of an asparagine attacks the following peptide group in black at top right of figure forming a symmetric succinimide intermediate in red the symmetry of the intermediate results in two products of its hydrolysis either aspartate in black at left or in isoaspartate which is a beta amino acid in green at bottom right this process is considered a deamidation because the amide in the asparagine side chain is replaced by a carboxylate group however a similar reaction can occur in aspartate side chains yielding a partial conversion to isoaspartate
the dear enemy effect or dear enemy recognition is an ethological phenomenon in which two neighbouring territorial animals become less aggressive toward one another once territorial borders are well established as territory owners become accustomed to their neighbours they expend less time and energy on defensive behaviors directed toward one another however aggression toward unfamiliar neighbours remains the same some authors have suggested the dear enemy effect is territory residents displaying lower levels of aggression toward familiar neighbours compared to unfamiliar individuals who are non territorial floaters the dear enemy effect has been observed in a wide range of animals including mammals birds reptiles amphibians fish and invertebrates the behavioural effect can be modulated by factors such as the location of the familiar and unfamiliar animal the season and the presence of females the dear enemy effect is the converse of the nasty neighbour effect in which some species are more aggressive towards their neighbours than towards unfamiliar strangers
death spiral is a condition of the insurance market in which costs rapidly increase as a result of changes in the covered population it is the result of adverse selection in insurance policies in which lower risk policy holders choose to change policies or be uninsured the term is found in the academic literature at least as early as cutler and zeckhauser s 1998 paper adverse selection in health insurance which refers explicitly to an adverse selection death spiral
in medicine debility is being weak or feeble
debt lag is a condition which results from overuse of one ’ s credit card or other forms of credit while travelling the debt itself can refer to the amount spent in the lead up to travelling during the trip and any unexpected costs which come about from that trip such as cross currency conversion fees and foreign atm access charges the condition of debt lag may last months or even years after a person ’ s trip is complete as long as the debt accrued within the travel period is still outstanding it is recommended that sufferers of debt lag seek treatment as soon as possible to avoid paying exorbitant fees in interest charges the term debt lag is similar to jet lag in that both have to do with travel however travellers can be affected by debt lag without leaving their time zone jet lag refers to the condition sustained by the body after rapid long distance travel which requires days of adjustment upon return debt lag works in much the same way as it refers to a traveller ’ s need to adjust upon return as well except it is more directly related to the traveller ’ s financial situation than their biological one
debt overhang is the condition of an organization for example a business government or family that has existing debt so great that it cannot easily borrow more money even when that new borrowing is actually a good investment that would more than pay for itself this problem emerges for example if a company has a new investment project with positive net present value npv but cannot capture the investment opportunity due to an existing debt position i e the face value of the existing debt is bigger than the expected payoff hence the equity holders will be reluctant to invest in such a project because most of the benefits will be reaped by the debt holders in addition debt holders will not finance the firm if the company cannot convince the debt holders that the project will not fail the situation emerges if existing debtholders of a company can be expected to lay claim to part of the profits of the new project and this renders the npv of the project when undertaken by this company negative
the debus radziszewski imidazole synthesis is an organic reaction used for the synthesis of imidazoles from a dicarbonyl an aldehyde and ammonia the dicarbonyl component is commonly glyoxal but can also include various 1 2 diketones and ketoaldehydes the method is used commercially to produce several imidazoles the process is an example of a multicomponent reaction the reaction can be viewed as occurring in two stages in the first stage the dicarbonyl and ammonia condense to give an diimine shown with unusual orientation of n h groups debus radziszewski imidazole synthesis part i in the second stage this diimine condenses with the aldehyde debus radziszewski imidazole synthesis part i this reaction is named after heinrich debus and bronisław leonard radziszewski a modification of this general method where one equivalent of ammonia is replaced by an amine affords n substituted imidazoles in good yields arduengo imidazoles
decalage on a fixed wing aircraft is the angle difference between the upper and lower wings of a biplane i e the acute angle contained between the chords of the wings in question the decalage is said to be positive when the upper wing has a higher angle of incidence than the lower wing and negative when higher wing s angle of incidence is lower than the angle of incidence of the lower wing positive decalage results in greater lift from the upper wing than the lower wing the difference increasing with the amount of decalage in real life the biplane top wing is usually rigged with less angle of incidence i e negative decalage causing the airstream separation and ensuing loss of lift stall occur first on the lower wing providing the biplane with extra margin of stability in stall decalage angle can also refer to the difference in angle of the chord line of the wing and the chord line of the horizontal stabilizer this is different from the angle of incidence which refers to the angle of the wing cord to the longitudinal axis of the fuselage without reference to the horizontal stabilizer file decalage jpg
decapitation from latin caput capitis meaning head is the complete separation of the head from the body in humans and most other animals death will always result from such an injury since severing the head deprives all other organs of the involuntary functions that are essential for the body to function while the brain itself is deprived of oxygenated blood the term beheading refers to the act of deliberately decapitating a person either as a means of murder or execution it may be accomplished for example with an axe sword knife or by other more sophisticated means such as a guillotine an executioner who carries out executions by beheading is called a headsman accidental decapitation can be the result of an explosion car or industrial accident improperly administered execution by hanging or other violent injury suicide by decapitation is rare but not unknown the national laws of saudi arabia yemen and qatar permit beheading but in practice saudi arabia is the only country that continues to behead its offenders regularly as a punishment for crime less commonly decapitation can also refer to the removal of the head from a body that is already dead this might be done to take the head as a trophy for public display to make the deceased more difficult to identify for cryonics or for other more esoteric reasons
decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide co 2 usually decarboxylation refers to a reaction of carboxylic acids removing a carbon atom from a carbon chain the reverse process which is the first chemical step in photosynthesis is called carboxylation the addition of co 2 to a compound enzymes that catalyze decarboxylations are called decarboxylases or the more formal term carboxy lyases ec number 4 1 1
decarboxylative cross coupling reactions are chemical reactions in which a stable substituted carboxylic acid is reacted with a halide r – x r aryl alkyl etc in the presence of a metal catalyst base and oxidant to form a new carbon carbon bond with loss of carbon dioxide decarboxylative cross coupling general reaction scheme a significant advantage of this reaction is that it uses relatively inexpensive carboxylic acids or their salts and is far less air and moisture sensitive in comparison to typical cross coupling organometallic reagents furthermore the carboxylic acid moiety is a common feature of natural products and can also be prepared by relatively benign air oxidations additional benefits include the broad tolerance of functional groups as well as the capacity to avoid the use of strong bases an important elementary step in this reaction is protodecarboxylation or metallation to first convert the c – cooh bond to a c – h or c – m bond respectively
in decision theory a decision rule is a function which maps an observation to an appropriate action decision rules play an important role in the theory of statistics and economics and are closely related to the concept of a strategy in game theory in order to evaluate the usefulness of a decision rule it is necessary to have a loss function detailing the outcome of each action under different states
the decolonization of asia was the gradual growth of independence movements on the asian continent leading ultimately to the retreat of foreign powers and the creation of a number of nation states in the region a number of events were catalysts for this shift most importantly the second world war prior to world war ii some countries such as the philippines during 1898 had proclaimed independence from spain
in medicine decompensation is the functional deterioration of a previously working structure or system decompensation may occur due to fatigue stress illness or old age when a system is compensated it is able to function despite stressors or defects decompensation describes an inability to compensate for these deficiencies it is a general term commonly used in medicine to describe a variety of situations
decompression sickness dcs also known as divers disease the bends or caisson disease describes a condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurisation dcs most commonly refers to problems arising from underwater diving decompression i e during ascent but may be experienced in other depressurisation events such as working in a caisson flying in an unpressurised aircraft and extravehicular activity from spacecraft since bubbles can form in or migrate to any part of the body dcs can produce many symptoms and its effects may vary from joint pain and rashes to paralysis and death individual susceptibility can vary from day to day and different individuals under the same conditions may be affected differently or not at all the classification of types of dcs by its symptoms has evolved since its original description over a hundred years ago exposure to dcs on diving can be managed through proper decompression procedures and contracting it is now uncommon its potential severity has driven much research to prevent it and divers universally use dive tables or dive computers to limit their exposure and to control their ascent speed if dcs is contracted it is treated by hyperbaric oxygen therapy in a recompression chamber if treated early there is a significantly higher chance of successful recovery dcs is a subset of decompression illness dci which includes both dcs and arterial gas embolism age
in object oriented programming the decorator pattern also known as wrapper an alternative naming shared with the adapter pattern is a design pattern that allows behavior to be added to an individual object either statically or dynamically without affecting the behavior of other objects from the same class the decorator pattern is often useful for adhering to the single responsibility principle as it allows functionality to be divided between classes with unique areas of concern
in marketing the decoy effect or asymmetric dominance effect is the phenomenon whereby consumers will tend to have a specific change in preference between two options when also presented with a third option that is asymmetrically dominated an option is asymmetrically dominated when it is inferior in all respects to one option but in comparison to the other option it is inferior in some respects and superior in others in other words in terms of specific attributes determining preferability it is completely dominated by i e inferior to one option and only partially dominated by the other when the asymmetrically dominated option is present a higher percentage of consumers will prefer the dominating option than when the asymmetrically dominated option is absent the asymmetrically dominated option is therefore a decoy serving to increase preference for the dominating option the decoy effect is also an example of the violation of the independence of irrelevant alternatives axiom of decision theory
decreolization is a phenomenon whereby over time a creole language reconverges with one of the standard languages from which it originally derived first proposed by keith whinnom at the 1968 mona conference the concept has come under fire in recent years from such linguists as bickerton and rickford since at its inception it sought to overturn long held elements of the theory of creole continua
in mathematics in particular the study of abstract algebra a dedekind – hasse norm is a function on an integral domain that generalises the notion of a euclidean function on euclidean domains
in an insurance policy the deductible is the amount of expenses that must be paid out of pocket before an insurer will pay any expenses in general usage the term deductible may be used to describe one of several types of clauses that are used by insurance companies as a threshold for policy payments deductibles are typically used to deter the large number of claims that a consumer can be reasonably expected to bear the cost of by restricting its coverage to events that are significant enough to incur large costs the insurance firm expects to pay out slightly smaller amounts much less frequently incurring much higher savings as a result insurance premiums are typically cheaper when they involve higher deductibles for example health insurance companies offer plans with high premiums and low deductibles or plans with low premiums and high deductibles one plan may have a premium of 1 087 a month with a 6 000 deductible while a competitive plan may have a premium of 877 a month with a 12 700 deductible the consumer with the 6 000 deductible will have to pay 6 000 in health care costs before the insurance plan pays anything the consumer with the 12 700 deductible will have to pay 12 700 deductibles are normally provided as clauses in an insurance policy that dictate how much of an insurance covered expense is borne by the policyholder they are normally quoted as a fixed quantity and are a part of most policies covering losses to the policy holder the insurer then becomes liable for claimable expenses that exceed this amount subject to the maximum sum claimable indicated in the contract depending on the policy the deductible may apply per covered incident or per year for policies where incidents are not easy to delimit health insurance for example the deductible is typically applied per year several deductibles can be set by the insurer based on the cause of the claim for example a single housing insurance policy may contain multiple deductible amounts for loss or damage arising from theft fire natural calamities evacuation etc there are also deductible reimbursement programs that reimburse a deductible in the event of an automobile home boat yacht or health insurance claim
deep dermatophytosis is a rare condition in which dermatophytes invades the deep dermis subcutis or even internal organs the known causes of this condition are caused by primary or secondary immunodeficiency which includes organ tranplant recipients maglignant conditionds e g leukemia hiv infection it is also associated with asthma atopic dermatitis and diabetes recently it has been proven that deficiency in the nf κb signaling pathways the nonsense mutation of card 9 complex caspase recruitment domain containing protein 9 are susceptible for chronic fungal infection thus also susceptible for deep dermatophytosis
deep vein thrombosis or deep venous thrombosis dvt is the formation of a blood clot thrombus within a deep vein most commonly the legs nonspecific signs may include pain swelling redness warmness and engorged superficial veins pulmonary embolism a potentially life threatening complication is caused by the detachment embolization of a clot that travels to the lungs together dvt and pulmonary embolism constitute a single disease process known as venous thromboembolism post thrombotic syndrome another complication significantly contributes to the health care cost of dvt in 1856 german pathologist rudolf virchow postulated the interplay of three processes resulting in venous thrombosis now known as virchow s triad a decreased blood flow rate venous stasis increased tendency to clot hypercoagulability and changes to the blood vessel wall dvt formation typically begins inside the valves of the calf veins where the blood is relatively oxygen deprived which activates certain biochemical pathways several medical conditions increase the risk for dvt including cancer trauma and antiphospholipid syndrome other risk factors include older age surgery immobilization as with bed rest orthopedic casts and sitting on long flights combined oral contraceptives pregnancy the postnatal period and genetic factors those genetic factors include deficiencies with antithrombin protein c and protein s the mutation of factor v leiden and the property of having a non o blood type individuals suspected of having dvt may be assessed using a clinical prediction rule such as the wells score a d dimer test may also be used to assist with excluding the diagnosis because of its high sensitivity or to signal a need for further testing diagnosis is most commonly done with ultrasound of the suspected veins prevention options for at risk individuals include early and frequent walking calf exercises anticoagulants aspirin graduated compression stockings and intermittent pneumatic compression anticoagulation is the standard treatment typical medications include low molecular weight heparin or a vitamin k antagonist wearing graduated compression stockings appears to reduce the risk of post thrombotic syndrome the rate of dvts increases from childhood to old age in adulthood about one in 1000 adults is affected per year
a deep water blackout is a loss of consciousness caused by cerebral hypoxia on ascending from a deep freedive or breath hold dive typically of ten metres or more when the swimmer does not necessarily experience an urgent need to breathe and has no other obvious medical condition that might have caused it victims typically black out close to the surface usually within the top three metres sometimes even as they break surface and have often been seen to approach the surface without apparent distress only to sink away it is quite rare for blackouts to occur while at the bottom or in the early stages of ascent divers who drown in these stages are usually found to have inhaled water indicating that they were conscious and succumbed to an uncontrollable urge to breathe rather than blacking out victims are usually established practitioners of deep breath hold diving are fit strong swimmers and have not experienced problems before survivors of deep water blackout are typically puzzled as to why they blacked out breath hold diving is often referred to elsewhere as dynamic apnoea diving or free diving blackout may also be referred to as a syncope medicine or fainting
defalcation is misappropriation of funds by a person trusted with its charge also the act of misappropriation or an instance thereof the term is more specifically used by the united states bankruptcy code to describe a category of acts that taint a particular debt such that it cannot be discharged in bankruptcy the united states supreme court addressed the issue in 2013 holding that defalcation in the context of the u s bankruptcy code requires proof of a culpable state of mind … involving knowledge of or gross recklessness in respect to the improper nature of the relevant fiduciary behavior in accounting terminology especially with respect to the area of audit defalcation means a misappropriation of assets or theft of assets by employees or officers of a corporation defalcation occurs when a debtor commits a bad act while acting in a fiduciary capacity the classic example of defalcation is when a trustee recklessly invests trust funds and loses the money if the beneficiary wins a judgment against the trustee and the trustee files for bankruptcy the debt the judgment cannot be discharged in bankruptcy because the debt was the result of a defalcation defalcation for example applies when a debtor is acting in a fiduciary capacity to constitute a defalcation the conduct involves a degree of culpability that is greater than negligence but the act does not need to rise to the level of a fraud under common law defalcation requires a showing of conscious behavior or extreme recklessness the term is used in legal proceedings other than bankruptcy to refer more generally to embezzlement it is often used in the context of the title insurance business a title agent who misuses funds intended to be used to close insured transactions is said to be involved in a defalcation many title insurers have their own defalcation units
defatting is the chemical dissolving of dermal lipids from the skin on contact with defatting agents this can result in water loss from the affected area and cause the whitening and drying of the skin which may result in cracking secondary infection and chemical irritant contact dermatitis
defaunation is the loss of animals from ecological communities the growth of the human population combined with advances in harvesting technologies has led to more intense and efficient exploitation of the environment this has resulted in the depletion of large vertebrates from ecological communities creating what has been termed empty forest defaunation differs from extinction it includes both the disappearance of species and declines in abundance defaunation effects were first implied at the symposium of plant animal interactions at the university of campinas brazil in 1988 in the context of neotropical forests since then the term has gained broader usage in conservation biology as a global phenomenon
a defense wound or self defense wound is an injury received by the victim of an attack while trying to defend against the assailant defensive wounds are often found on the hands and forearms where the victim has raised them to protect the head and face or to fend off an assault but may also be present on the feet and legs where a victim attempts defense while lying down and kicking out at the assailant the appearance and nature of the wound varies with the type of weapon used and the location of the injury and may present as a laceration abrasion contusion or bone fracture where a victim has time to raise hands or arms before being shot by an assailant the injury may also present as a gunshot wound severe laceration of the palmar surface of the hand or partial amputation of fingers may result from the victim grasping the blade of a weapon during an attack in forensic pathology the presence of defense wounds is highly indicative of homicide and also proves that the victim was at least initially conscious and able to offer some resistance during the attack defense wounds may be classified as active or passive a victim of a knife attack for example would receive active defense wounds from grasping at the knife s blade and passive defense wounds on the back of the hand if it was raised up to protect the face
a defensive war is one of the causes that justify war by the criteria of the just war tradition it means a war where at least one nation is mainly trying to defend itself from another as opposed to a war where both sides are trying to invade and conquer each other
deference also called submission or passivity is the condition of submitting to the espoused legitimate influence of one s superior or superiors deference implies a yielding or submitting to the judgment of a recognized superior out of respect or reverence deference has been studied extensively by political scientists sociologists and psychologists
in medicine a deficiency is a lack or shortage of a functional entity by less than normal or necessary supply or function
deficiency of the interleukin 1 – receptor antagonist dira is a rare autosomal recessive genetic autoinflammatory syndrome resulting from mutations in il 1 rn the gene encoding the interleukin 1 receptor antagonist the mutations result in an abnormal protein that is not secreted exposing the cells to unopposed interleukin 1 activity this results in sterile multifocal osteomyelitis bone inflammation in multiple places periostitis inflammation of the membrane surrounding the bones and pustulosis due to skin inflammation from birth dira is a newly discovered autoinflammatory disease children with the disorder display a constellation of serious and potentially fatal symptoms that include swelling of bone tissue bone pain and deformity inflammation of the periosteum a layer of connective tissue around bone and a rash that can span from small individual pustules to extensive pustulosis that covers most of the patient ’ s body most of the children begin to have symptoms from birth to 2 weeks of age children with dira have inherited mutations in il 1 rn a gene that encodes a protein known as il 1 receptor antagonist il 1 ra il 1 ra binds to the same cell receptors as the inflammatory protein il 1 and blocks its inflammatory actions without il 1 ra the children ’ s bodies cannot control systemic inflammation that can be caused by il 1 although mutations that cause dira are rare as many as 2 5 percent of the population of northwest puerto rico are carriers since dira is recessively inherited these data suggest that it may be present in about 1 in 6 300 births in this population mutations may also be more common in individuals of dutch descent most patients with dira respond well to anakinra the same drug previously mentioned for nomid treatment a synthetic form of human il 1 ra
deficit spending is the amount by which spending exceeds revenue over a particular period of time also called simply deficit or budget deficit the opposite of budget surplus the term may be applied to the budget of a government private company or individual government deficit spending is a central point of controversy in economics as discussed below
in economics deflation can be described as a decrease in the general price level of goods and services or currency appreciation with respect to the same goods and services deflation occurs when the inflation rate falls below 0 a negative inflation rate inflation reduces the real value of money over time conversely deflation increases the real value of money – the currency of a national or regional economy this allows one to buy more goods and services than before with the same amount of money economists generally believe that deflation is a problem in a modern economy because it may increase the real value of debt especially if unpredictable and may aggravate recessions and lead to a deflationary spiral deflation is distinct from disinflation a slow down in the inflation rate i e when inflation declines to a lower rate but is still positive
deforestation is one of the main causes of climate change it is the second largest anthropogenic source of carbon dioxide to the atmosphere after fossil fuel combustion deforestation and forest degradation contribute to atmospheric greenhouse gas emissions through combustion of forest biomass and decomposition of remaining plant material and soil carbon it used to account for more than 20 of carbon dioxide emissions but it ’ s currently somewhere around the 10 mark by 2008 deforestation was 12 of total co 2 or 15 if peatlands are included these proportions are likely to have fallen since given the continued rise of fossil fuel use averaged over all land and ocean surfaces temperatures warmed roughly 1 53 ° f 0 85 ° c between 1880 and 2012 according to the intergovernmental panel on climate change in the northern hemisphere 1983 to 2012 were the warmest 30 year period of the last 1400 years
deforestation in haiti is a severe environmental problem haitians burn wood charcoal for 60 of their domestic energy production in 1923 over 60 of haiti s land was forested in 2006 less than 2 of the land was forested this estimate has been challenged as incorrect and a product of cultural bias by researchers conducting actual research and the true basis for this 2 estimate is unknown a better estimate is 32 and much of the impetus for earlier estimates of 2 were likely biased researchers attempting to characterize the independent black republic of haiti as overpopulated and ignorant in recent times this 2 estimate that has no basis in scientific literature has been used repeatedly by non profit and charities to solicit donations and characterise haiti and haitians as either ignorant or hopeless instead evidence points to the widespread use of charcoal by haitians to be a source of reforestation as economically and environmentally adept haitians use long held practices to protect and regenerate the first resources to create a sustainable source for coal
a deformity dysmorphism or dysmorphic feature is a major abnormality in the shape of a body part or organ compared to the normal shape of that part
degeneration is deterioration in the medical sense generally it is the change from a higher to a lower form more specifically it is the change of tissue to a lower or less functionally active form true degeneration when there is actual chemical change of the tissue itself infiltration when the change consists of the deposit of abnormal matter in the tissues degenerative disease
degeneration of one or more intervertebral disc s of the spine often called degenerative disc disease ddd or degenerative disc disorder is a pathologic process of certain pathology that may cause acute or chronic low back or neck pain the typical radiographic findings in ddd are black discs disc space narrowing vacuum disc end plate sclerosis and osteophyte formation ddd can greatly affect the sufferer s quality of life disc degeneration is a disease of micro macro trauma and of aging and though for most people is not a problem in certain individuals a degenerated disc can cause severe chronic pain if left untreated
degos disease also called malignant atrophic papulosis is a rare vasculopathy that affects the lining of the medium and small veins and arteries resulting in occlusion blockage of the vessel and tissue infarction the blood vessels affected include those supplying the skin gastrointestinal tract and central nervous system this can result in bowel ischemia mesenteric ischemia or ischemic colitis chronic skin lesions ocular lesions strokes spinal lesions mononeuritis multiplex epilepsy headaches or cognitive disorders pleural or pericardial effusions are also reported there are fewer than 50 living patients at present known worldwide and fewer than 200 reported in medical literature the outcome of this disease can be fatal with a median survival of 2 to 3 years although some appear to have a benign form degos acanthoma which affects only the skin laparoscopy may be an effective means of screening those with cutaneous lesions to determine if systemic disease is present treatment options are limited and until recently consisted mainly of antiplatelet drugs or anticoagulants or immunosuppressants with few reports of prolonged survival more recently eculizumab and treprostinil have been employed response to eculizumab is often immediate and dramatic but has been of limited duration in all so treated treprostinil use has been reported to result in clearing of gastrointestinal and cns findings as well as clearing of cutaneous lesions but reports are limited treprostinil may be more effective than other vasodilators because it may also increase the population of circulating endothelial cells allowing angiogenesis there are suggestions that degos disease is not a separate disorder but the final result of several vascular systemic disorders
in telecommunication degradation is the loss of quality of an electronic signal which may be categorized as either graceful or catastrophic and has the following meanings 1 the deterioration in quality level or standard of performance of a functional unit 2 in communications a condition in which one or more of the required performance parameters fall outside predetermined limits resulting in a lower quality of service there are several forms and causes of degradation in electric signals both in the time domain and in the physical domain including runt pulse voltage spike jitter wander swim drift glitch ringing crosstalk antenna effect not the same antenna effect as in ic manufacturing and phase noise degradation usually refers to reduction in quality of an analog or digital signal when a signal is being transmitted or received it undergoes changes which are undesirable these changes are called degradation degradation is usually caused by 1 weather or environmental conditions 2 terrain 3 other signals 4 faulty or poor quality equipment
in graph theory the degree diameter problem is the problem of finding the largest possible graph g in terms of the size of its vertex set v of diameter k such that the largest degree of any of the vertices in g is at most d the size of g is bounded above by the moore bound for 1 k and 2 d only the petersen graph the hoffman singleton graph and maybe a graph of diameter k 2 and degree d 57 attain the moore bound in general the largest degree diameter graphs are much smaller in size than the moore bound
in the mathematical subject of geometric group theory a dehn function named after max dehn is an optimal function associated to a finite group presentation which bounds the area of a relation in that group that is a freely reduced word in the generators representing the identity element of the group in terms of the length of that relation see pp 79 – 80 in the growth type of the dehn function is a quasi isometry invariant of a finitely presented group the dehn function of a finitely presented group is also closely connected with non deterministic algorithmic complexity of the word problem in groups in particular a finitely presented group has solvable word problem if and only if the dehn function for a finite presentation of this group is recursive see theorem 2 1 in the notion of a dehn function is motivated by isoperimetric problems in geometry such as the classic isoperimetric inequality for the euclidean plane and more generally the notion of a filling area function that estimates the area of a minimal surface in a riemannian manifold in terms of the length of the boundary curve of that surface
dehydration refers to a deficit of total body water with an accompanying disruption of metabolic processes dehydration is also a cause for hypernatremia the term dehydration is distinct from hypovolemia loss of blood volume particularly plasma dehydration occurs when free water loss exceeds free water intake usually due to exercise or disease but also due to high environmental temperature mild dehydration can be also be caused by immersion diuresis and this may increase risk of decompression sickness in divers most people can tolerate a three to four percent decrease in total body water without difficulty or adverse health effects a five to eight percent decrease can cause fatigue and dizziness loss of over ten percent of total body water can cause physical and mental deterioration accompanied by severe thirst death occurs at a loss of between fifteen and twenty five percent of the body water mild dehydration is characterized by thirst and general discomfort and is usually resolved with oral rehydration
dehydrogenation is a chemical reaction that involves the removal of hydrogen from a molecule it is the reverse of hydrogenation dehydrogenation is an important reaction because it converts alkanes which are relatively inert and thus low valued to olefins which are reactive and thus more valuable alkenes are precursors to aldehydes alcohols polymers and aromatics dehydrogenation processes are used extensively to produce aromatics and styrene in the petrochemical industry such processes are highly endothermic and require temperatures of 500 ° c and above dehydrogenation also converts saturated fats to unsaturated fats enzymes that catalyze dehydrogenation are called dehydrogenases
dehydrohalogenation is an chemical reaction that involves removal of elimination of a hydrogen halide from a substrate the reaction is usually associated with the synthesis of alkenes but it has wider applications
dejerine – roussy syndrome or thalamic pain syndrome is a condition developed after a thalamic stroke a stroke causing damage to the thalamus ischemic strokes and hemorrhagic strokes can cause lesioning in the thalamus the lesions usually present in one hemisphere of the brain most often cause an initial lack of sensation and tingling in the opposite side of the body weeks to months later numbness can develop into severe and chronic pain that is not proportional to an environmental stimulus called dysaesthesia or allodynia as initial stroke symptoms numbness and tingling dissipate an imbalance in sensation causes these later syndromes characterizing dejerine – roussy syndrome although some treatments exist they are often expensive chemically based invasive and only treat patients for some time before they need more treatment called refractory treatment
dejerine – sottas disease also known as dejerine – sottas syndrome dejerine – sottas neuropathy progressive hypertrophic interstitial polyneuropathy of childhood and onion bulb neuropathy and hereditary motor and sensory polyneuropathy type iii and charcot – marie – tooth disease type 3 is a hereditary neurological disorder characterised by damage to the peripheral nerves and resulting progressive muscle wasting the condition is caused by mutations in a various genes and currently has no known cure the disorder is named for joseph jules dejerine and jules sottas french neurologists who first described it
delay is an audio effect which records an input signal to an audio storage medium and then plays it back after a period of time the delayed signal may either be played back multiple times or played back into the recording again to create the sound of a repeating decaying echo delay effects range from a subtle echo effect to a pronounced blending of previous sounds with new sounds delay effects can be created using tape loops an approach developed in the 1940 s and 1950 s analog effects units which were introduced in the 1970 s digital effects pedals introduced in 1984 and audio software plugins developed in the 2000 s
delayed blisters are a cutaneous condition observed weeks to months after the initial healing of second degree thermal burns donor sites of split thickness skin grafts and recipient sites of split thickness skin grafts
delayed ejaculation also called retarded ejaculation or inhibited ejaculation is a man s inability for or persistent difficulty in achieving orgasm despite typical sexual desire and sexual stimulation generally a man can reach orgasm within a few minutes of active thrusting during sexual intercourse whereas a man with delayed ejaculation either does not have orgasms at all or cannot have an orgasm until after prolonged intercourse which might last for 30 – 45 minutes or more in most cases delayed ejaculation presents the condition in which the man can climax and ejaculate only during masturbation but not during sexual intercourse it is the least common of the male sexual dysfunctions and can result as a side effect of some medications in one survey 8 of men reported being unable to achieve orgasm over a 2 month period or longer in the previous year
delayed gratification or deferred gratification is the ability to resist the temptation for an immediate reward and wait for a later reward generally delayed gratification is associated with resisting a smaller but more immediate reward in order to receive a larger or more enduring reward later a growing body of literature has linked the ability to delay gratification to a host of other positive outcomes including academic success physical health psychological health and social competence a person s ability to delay gratification relates to other similar skills such as patience impulse control self control and willpower all of which are involved in self regulation broadly self regulation encompasses a person s capacity to adapt the self as necessary to meet demands of the environment delaying gratification is the reverse of delay discounting which is the preference for smaller immediate rewards over larger but delayed rewards and refers to the fact that the subjective value of reward decreases with increasing delay to its receipt it is theorized that the ability to delay rewards is under the control of the cognitive affective personality system caps several factors can affect a person s ability to delay gratification cognitive strategies such as the use of distracting or cool thoughts can increase delay ability as can neurological factors such as strength of connections in the frontal striatal pathway behavioral researchers have focused on the contingencies that govern choices to delay reinforcement and have studied how to manipulate those contingencies in order to lengthen delay age plays a role too children under 5 years old demonstrate a marked lack of delayed gratification ability and most commonly seek immediate gratification a very small difference between males and females suggest that females may be better at delaying rewards the ability to wait or seek immediate reinforcement is related to avoidance related behaviors such as procrastination and to other clinical diagnoses such as anxiety attention deficit hyperactivity disorder and depression sigmund freud the father of psychoanalytic theory discussed the ego s role in balancing the immediate pleasure driven desires of the id with the morality driven choices of the superego funder and block expanded psychoanalytic research on the topic and found that impulsivity or a lack of ego control has a stronger effect on one s ability to delay rewards if a reward is more desirable finally environmental and social factors play a role for example delay is affected by the self imposed or external nature of a reward contingency by the degree of task engagement required during the delay by early mother child relationship characteristics by a person s previous experiences with unreliable promises of rewards e g in poverty and by contemporary sociocultural expectations and paradigms research on animals comprises another body of literature describing delayed gratification characteristics that are not as easily tested in human samples such as ecological factors affecting the skill
a delayed hemolytic transfusion reaction is a type of transfusion reaction this can occur one to four weeks after the transfusion one way this can occur is if a person without a kidd blood antigen receives a kidd antigen in a transfusion a hemolytic reaction can occur between 3 and 14 days as a result of a secondary immune response with a drop in hemoglobin level fever jaundice or hemoglobinuria
delayed milestone also called developmental delays is used to describe the condition where a child does not reach one of these stages at the expected age however in most cases a wide variety of ages can be considered normal and not a cause for medical concern milestones are often measured using percentiles and for many milestones a value between the 5 th and 95 th percentile does not require intervention though values towards the edges of that range can be associated with other medical conditions it is not possible to treat it has been suggested that measurement of posture sway may be an early indicator
delayed onset muscle soreness doms also called muscle fever is the pain and stiffness felt in muscles several hours to days after unaccustomed or strenuous exercise the soreness is felt most strongly 24 to 72 hours after the exercise it is thought to be caused by eccentric lengthening exercise which causes microtrauma to the muscle fibers after such exercise the muscle adapts rapidly to prevent muscle damage and thereby soreness if the exercise is repeated delayed onset muscle soreness is one symptom of exercise induced muscle damage the other is acute muscle soreness which appears during and immediately after exercise
puberty is described as delayed puberty with exceptions when an organism has passed the usual age of onset of puberty with no physical or hormonal signs that it is beginning puberty may be delayed for several years and still occur normally in which case it is considered constitutional delay of growth and puberty a variation of healthy physical development delay of puberty may also occur due to malnutrition many forms of systemic disease or to defects of the reproductive system hypogonadism or the body s responsiveness to sex hormones
delayed sleep phase disorder dspd also known as delayed sleep phase syndrome or delayed sleep phase type and in the 2014 revision of the international classification of sleep disorders iscd 3 delayed sleep wake phase disorder is a chronic dysregulation of a person s circadian rhythm biological clock compared to the general population and relative to societal norms the disorder affects the timing of sleep peak period of alertness the core body temperature rhythm and hormonal and other daily cycles people with dspd generally fall asleep some hours after midnight and have difficulty waking up in the morning people with dspd probably have a circadian period significantly longer than 24 hours depending on the severity the symptoms can be managed to a greater or lesser degree but no cure is known affected people often report that while they do not get to sleep until the early morning they do fall asleep around the same time every day unless they have another sleep disorder such as sleep apnea in addition to dspd patients can sleep well and have a normal need for sleep however they find it very difficult to wake up in time for a typical school or work day if they are allowed to follow their own schedules e g sleeping from 3 00 am to 12 00 noon their sleep is improved and they may not experience excessive daytime sleepiness attempting to force oneself onto daytime society s schedule with dspd has been compared to constantly living with jet lag dspd has in fact been referred to as social jet lag the syndrome usually develops in early childhood or adolescence an adolescent version may disappear in late adolescence or early adulthood otherwise dspd is a lifelong condition prevalence among adults equally distributed among women and men is around 0 15 or three in 2 000 prevalence among adolescents is as much as 7 – 16 dspd was first formally described in 1981 by elliot d weitzman and others at montefiore medical center it is responsible for 7 – 10 of patient complaints of chronic insomnia however since many doctors are unfamiliar with the condition it often goes untreated or is treated inappropriately dspd is often misdiagnosed as primary insomnia or as a psychiatric condition dspd can be treated or helped in some cases by careful daily sleep practices light therapy dark therapy and medications such as melatonin and modafinil provigil the former is a natural neurohormone partly responsible for the human body clock at its most severe and inflexible dspd is a disability a chief difficulty of treating dspd is in maintaining an earlier schedule after it has been established as the patient s body has a strong tendency to reset the sleeping schedule to its intrinsic late times people with dspd may improve their quality of life by choosing careers that allow late sleeping times rather than forcing themselves to follow a conventional 9 to 5 work schedule
in software engineering the delegation pattern is a design pattern in object oriented programming that allows object composition to achieve the same code reuse as inheritance in the example below using the kotlin programming language the class window delegates the area call to its internal rectangle object its delegate class rectangle val width int val height int fun area width height class window val bounds rectangle delegation fun area bounds area some languages have special support for delegation built in in delegation an object handles a request by delegating to a second object the delegate the delegate is a helper object but with the original context with language level support for delegation this is done implicitly by having a href mediawiki index php title self computer science class mw redirect title self computer science self a in the delegate refer to the original sending object not the delegate receiving object in the delegate pattern this is instead accomplished by explicitly passing the original object to the delegate as an argument to a method note that delegation is often used loosely to refer to the distinct concept of forwarding where the sending object simply uses the corresponding member on the receiving object evaluated in the context of the receiving object not the original object
delirium or acute confusional state is an organically caused decline from a previously attained baseline level of cognitive function it is typified by fluctuating course attentional deficits and generalized severe disorganization of behavior it typically involves other cognitive deficits changes in arousal hyperactive hypoactive or mixed perceptual deficits altered sleep wake cycle and psychotic features such as hallucinations and delusions delirium itself is not a disease but rather a clinical syndrome a set of symptoms it may result from an underlying disease over consumption of alcohol from drugs administered during treatment of a disease withdrawal from drugs or from any number of health factors delirium may be difficult to diagnose without the proper establishment of the baseline mental function of a patient delirium may be caused by a disease process outside the brain that nonetheless affects the brain such as infection urinary tract infection pneumonia or drug effects particularly anticholinergics or other cns depressants benzodiazepines and opioids although hallucinations and delusions are sometimes present in delirium these are not required for the diagnosis and the symptoms of delirium are clinically distinct from those induced by psychosis or hallucinogens with the exception of deliriants delirium must by definition be caused by an organic process i e a physically identifiable structural functional or chemical problem in the brain see organic brain syndrome and thus fluctuations of mentation due to changes in purely psychiatric processes or diseases such as sudden psychosis from schizophrenia or bipolar disorder are by definition not termed delirium like its components inability to focus attention mental confusion and various impairments in awareness and temporal and spatial orientation delirium is the common manifestation of new organic brain dysfunction for any reason delirium requires both a sudden change in mentation and an organic cause for this thus without careful assessment and history delirium can easily be confused with a number of psychiatric disorders or long term organic brain syndromes because many of the signs and symptoms of delirium are conditions also present in dementia depression and psychosis delirium may newly appear on a background of mental illness baseline intellectual disability or dementia without being due to any of these problems treatment of delirium requires treating the underlying cause in some cases temporary or palliative or symptomatic treatments are used to comfort the person or to allow other care for example a person who without understanding is trying to pull out a ventilation tube that is required for survival delirium is probably the single most common acute disorder affecting adults in general hospitals it affects 10 20 of all hospitalized adults and 30 40 of elderly who are hospitalized and up to 80 of those in icu among those requiring critical care delirium is a risk for death within the next year antipsychotics are not supported for the treatment or prevention of delirium among those who are in hospital however when delirium is caused by alcohol or sedative hypnotic withdrawal benzodiazepines are typically used
delirium tremens dts is a rapid onset of confusion usually caused by withdrawal from alcohol when it occurs it is often three days into the withdrawal symptoms and lasts for two to three days people may also see or hear things other people do not physical effects may include shaking shivering irregular heart rate and sweating occasionally a very high body temperature or seizures may result in death alcohol is one of the most dangerous drugs to experience withdrawal from delirium tremens typically only occurs in people with a high intake of alcohol for more than a month a similar syndrome may occur with benzodiazepine and barbiturate withdrawal withdrawal from stimulants such as cocaine does not have major medical complications in a person with delirium tremens it is important to rule out other associated problems such as electrolyte abnormalities pancreatitis and alcoholic hepatitis prevention is by treating withdrawal symptoms if delirium tremens occurs aggressive treatment improves outcomes treatment in a quiet intensive care unit with sufficient light is often recommended benzodiazepines are the medication of choice with diazepam lorazepam chlordiazepoxide and oxazepam all commonly used they should be given until a person is lightly sleeping the antipsychotic haloperidol may also be used the vitamin thiamine is recommended mortality without treatment is between 15 and 40 currently death occurs in about 1 to 4 of cases about half of people with alcoholism will develop withdrawal symptoms upon reducing their use of these three to five percent develop dts or have seizures the name delirium tremens was first used in 1813 however the symptoms were well described since the 1700 s the word delirium is latin for going off the furrow a plowing metaphor it is also called shaking frenzy and saunders sutton syndrome include barrel fever blue horrors bottleache bats drunken horrors elephants gallon distemper quart mania pink spiders among others
delta beta thalassemia is a form of thalassemia and is autosomal recessive in terms of heredity it is associated with hemoglobin subunit delta
delusional disorder is a mental illness in which the patient presents with delusions but with no accompanying prominent hallucinations thought disorder mood disorder or significant flattening of affect delusions are a specific symptom of psychosis delusions can be bizarre or non bizarre in content non bizarre delusions are fixed false beliefs that involve situations that could potentially occur in real life examples include being followed or poisoned apart from their delusions people with delusional disorder may continue to socialize and function in a normal manner and their behavior does not generally seem odd or bizarre however the preoccupation with delusional ideas can be disruptive to their overall lives for the diagnosis to be made auditory and visual hallucinations cannot be prominent though olfactory or tactile hallucinations related to the content of the delusion may be present to be diagnosed with a delusional disorder the delusion s cannot be due to the effects of a drug medication or general medical condition and delusional disorder cannot be diagnosed in an individual previously properly diagnosed with schizophrenia a person with delusional disorder may be high functioning in daily life recent and comprehensive metaanalyses of scientific studies point to an association between a deterioration in aspects of iq in psychotic patients in particular perceptual reasoning according to german psychiatrist emil kraepelin patients with delusional disorder remain coherent sensible and reasonable the diagnostic and statistical manual of mental disorders dsm defines six subtypes of the disorder characterized as erotomanic believes that someone is in love with them grandiose believes that they are the greatest strongest fastest richest and or most intelligent person ever jealous believes that the love partner is cheating on them persecutory delusions that the person or someone to whom the person is close is being malevolently treated in some way somatic believes that they have a disease or medical condition and mixed i e having features of more than one subtype delusions also occur as symptoms of many other mental disorders especially the other psychotic disorders the dsm iv and psychologists generally agree that personal beliefs should be evaluated with great respect to cultural and religious differences since some cultures have widely accepted beliefs that may be considered delusional in other cultures
delusional parasitosis also known as delusional infestation or ekbom s syndrome is a delusional disorder in which individuals incorrectly believe they are infested with parasites insects or bugs whereas in reality no such infestation is present individuals with delusional parasitosis usually report tactile hallucinations known as formication a sensation resembling insects crawling on or under the skin delusional parasitosis is a mental disorder characterized by a fixed false belief that a skin infestation exists which is in contrast to cases of actual parasitosis such as scabies and infestation with demodex in which a skin infestation is present and identifiable by a physician through physical examination or laboratory tests morgellons is poorly understood but appears to be a form of this condition the alternative name ekbom s syndrome was named after swedish neurologist karl axel ekbom who published seminal accounts of the disease in 1937 and 1938 it is differentiated from willis ekbom disease wed another name for restless legs syndrome
demand vacuum in economics and marketing is the effect created by consumer demand on the supply chain the term refers to an analogy whereby consumer demand for a product or service creates a vacuum at the end of the supply chain which pulls the product through the chain by causing the suppliers to provide more product the marketing strategy of pull strategy aims to create a demand vacuum through advertising and promotion to the consumer this is to be compared with push strategy that tries to push the product through the supply chain by promoting the product to sellers and encouraging them to carry it
dementia also known as senility is a broad category of brain diseases that cause a long term and often gradual decrease in the ability to think and remember that is great enough to affect a person s daily functioning other common symptoms include emotional problems problems with language and a decrease in motivation a person s consciousness is usually not affected a dementia diagnosis requires a change from a person s usual mental functioning and a greater decline than one would expect due to aging these diseases also have a significant effect on a person s caregivers the most common type of dementia is alzheimer s disease which makes up 50 to 70 of cases other common types include vascular dementia 25 lewy body dementia 15 and frontotemporal dementia less common causes include normal pressure hydrocephalus parkinson s disease syphilis and creutzfeldt – jakob disease among others more than one type of dementia may exist in the same person a small proportion of cases run in families in the dsm 5 dementia was reclassified as a neurocognitive disorder with various degrees of severity diagnosis is usually based on history of the illness and cognitive testing with medical imaging and blood work used to rule out other possible causes the mini mental state examination is one commonly used cognitive test efforts to prevent dementia include trying to decrease risk factors such as high blood pressure smoking diabetes and obesity screening the general population for the disorder is not recommended there is no cure for dementia cholinesterase inhibitors such as donepezil are often used and may be beneficial in mild to moderate disorder overall benefit however may be minor for people with dementia and those who care for them many measures can improve their lives cognitive and behavioral interventions may be appropriate educating and providing emotional support to the caregiver is important exercise programs are beneficial with respect to activities of daily living and potentially improve outcomes treatment of behavioral problems with antipsychotics is common but not usually recommended due to the little benefit and side effects including an increased risk of death globally dementia affects 36 million people about 10 of people develop the disorder at some point in their lives it becomes more common with age about 3 of people between the ages of 65 – 74 have dementia 19 between 75 and 84 and nearly half of those over 85 years of age in 2013 dementia resulted in about 1 7 million deaths up from 0 8 million in 1990 as more people are living longer dementia is becoming more common in the population as a whole for people of a specific age however it may be becoming less frequent at least in the developed world due to a decrease in risk factors it is one of the most common causes of disability among the old it is believed to result in economic costs of 604 billion usd a year people with dementia are often physically or chemically restrained to a greater degree than necessary raising issues of human rights social stigma against those affected is common
dementia praecox a premature dementia or precocious madness is a chronic deteriorating psychotic disorder characterized by rapid cognitive disintegration usually beginning in the late teens or early adulthood schizophrenia is the new word describing this disease the term was first used in 1891 by arnold pick 1851 – 1924 a professor of psychiatry at charles university in prague his brief clinical report described the case of a person with a psychotic disorder resembling hebephrenia german psychiatrist emil kraepelin 1856 – 1926 popularised it in his first detailed textbook descriptions of a condition that eventually became a different disease concept and relabeled as schizophrenia kraepelin reduced the complex psychiatric taxonomies of the nineteenth century by dividing them into two classes manic depressive psychosis and dementia praecox this division commonly referred to as the kraepelinian dichotomy had a fundamental impact on twentieth century psychiatry though it has also been questioned the primary disturbance in dementia praecox is a disruption in cognitive or mental functioning in attention memory and goal directed behaviour kraepelin contrasted this with manic depressive psychosis now termed bipolar disorder and also with other forms of mood disorder including major depressive disorder he eventually concluded that it was not possible to distinguish his categories on the basis of cross sectional symptoms kraepelin viewed dementia praecox as a progressively deteriorating disease from which no one recovered however by 1913 and more explicitly by 1920 kraepelin admitted that while there may be a residual cognitive defect in most cases the prognosis was not as uniformly dire as he had stated in the 1890 s still he regarded it as a specific disease concept that implied incurable inexplicable madness
dementia pugilistica dp is a type of chronic traumatic encephalopathy cte a neurodegenerative disease with features of dementia dp may affect amateur or professional boxers wrestlers as well as athletes in other sports who suffer concussions dp is also called chronic boxer s encephalopathy traumatic boxer ’ s encephalopathy boxer s dementia chronic traumatic brain injury associated with boxing ctbi b and punch drunk syndrome dp was historically considered equivalent to cte but is now considered a subtype of cte the condition is caused by repeated concussive and sub concussive blows blows that are below the threshold of force necessary to cause concussion or both because of the concern that boxing may cause dp there is a movement among medical professionals to ban the sport medical professionals have called for such a ban since as early as the 1950 s symptoms and signs of dp develop progressively over a long latent period sometimes amounting to decades with the average time of onset being about 12 to 16 years after the start of a career in boxing the condition is thought to affect around 15 to 20 of professional boxers
dementia with lewy bodies dlb is a type of dementia that gradually worsens over time additional symptoms may include fluctuations in alertness seeing things that other people do not slowness of movement trouble walking and rigidity excessive movement during sleep and mood changes such as depression are also common the cause is unknown there is typically no family history among those affected the underlying mechanism involves the buildup of lewy bodies clumps of alpha synuclein protein in neurons it is classified as a neurodegenerative disorder a diagnosis may be suspected based on symptom with blood tests and medical imaging done to rule out other possible causes the differential diagnosis includes parkinson s and alzheimer s there is no cure for dlb treatments try to improve mental psychiatric and motor symptoms acetylcholinesterase inhibitors such as donepezil may provide some benefit some motor problems may improve with levodopa antipsychotics even for hallucination should generally be avoided due to side effects dlb is the most common cause of dementia after alzheimer s and vascular dementia it typically begins after the age of 50 about 0 1 of those over 65 are affected males appear to be more commonly affected than females in the late part of the disease people may depend entirely on others for their care life expectancy following diagnosis is around 8 years the abnormal deposits that cause the disease were discovered in 1912 by frederic lewy
the demjanov rearrangement is the chemical reaction of primary amines with nitrous acid to give rearranged alcohols it involves substitution by a hydroxyl group with a possible ring expansion it is named after the russian chemist nikolai jakovlevich demjanov dem anov demianov 1861 – 1938
demodex mite bite is a cutaneous condition caused by infestation by demodex folliculorum
demodicosis also called demodectic mange or red mange is caused by a sensitivity to and overpopulation of demodex canis as the animal s immune system is unable to keep the mites under control demodex is a genus of mite in the family demodicidae demodex canis occurs naturally in the hair follicles of most dogs in low numbers around the face and other areas of the body in most dogs these mites never cause problems however in certain situations such as an underdeveloped or impaired immune system intense stress or malnutrition the mites can reproduce rapidly causing symptoms in sensitive dogs that range from mild irritation and hair loss on a small patch of skin to severe and widespread inflammation secondary infection and in rare cases can be a life threatening condition small patches of demodicosis often correct themselves over time as the dog s immune system matures although treatment is usually recommended
as of 2005 alaska has an estimated population of 663 661 which is an increase of 5 906 or 0 9 from the prior year and an increase of 36 730 or 5 9 since the year 2000 this includes a natural increase since the last census of 36 590 people 53 132 births minus 16 542 deaths and an increase due to net migration of 1 181 people into the state immigration from outside the united states resulted in a net increase of 5 800 people and migration within the country produced a net loss of 4 619 people more than half of the state s population lives in anchorage juneau and fairbanks with two fifths in anchorage alone as of 1 january 2012 alaska had a population of 731 449 with a population of 710 231 according to the 2010 u s census alaska is the 47 th most populous and least densely populated state for purposes of the federal census the state is divided into artificial divisions defined geographically by the united states census bureau for statistical purposes only the center of population of alaska is located approximately 64 37 kilometers 40 00 mi east of anchorage at 61 288254 n latitude 148 716968 w longitude in 2006 alaska had a larger percentage of tobacco smokers than the national average with 24 of alaskan adults smoking
as of 2009 arizona had a population of 6 343 million which is an increase of 213 311 or 3 6 from the prior year and an increase of 1 035 686 or 20 2 since the year 2000 this includes a natural increase since the last census of 297 928 people that is 564 062 births minus 266 134 deaths and an increase due to net migration of 745 944 people into the state immigration from outside the united states resulted in a net increase of 204 661 people and migration within the country produced a net increase of 541 283 people new population figures for the year ending july 1 2006 indicate that arizona is the fastest growing state in the united states with 3 6 population growth since 2005 exceeding the growth of the previous leader nevada the most recent population estimates released by the us census put the population at 6 828 065 in 2015 the population density of the state is 45 2 people per square mile in 2010 there were an estimated 460 000 illegal immigrants in the state these constituted an estimated 7 9 of the population the center of population of arizona is located in maricopa county which contains over 61 of arizona s population
as of july 1 2006 the united states commonwealth of kentucky had an estimated population of 4 206 074 which is an increase of 33 466 or 0 8 from the prior year and an increase of 164 586 or 4 1 since the year 2000 this includes a natural increase since the last census of 77 156 people that is 287 222 births minus 210 066 deaths and an increase due to net migration of 59 604 people into the state immigration from outside the united states resulted in a net increase of 27 435 people and migration within the country produced a net increase of 32 169 people as of 2004 kentucky s population included about 95 000 foreign born 2 3 the population density of the state is 101 7 people per square mile kentucky s total population has grown during every decade since records began however during most decades of the 20 th century there was also net out migration from kentucky since 1900 rural kentucky counties have experienced a net loss of over 1 million people from migration while urban areas have experienced a slight net gain the center of population of kentucky is located in washington county in the city of willisburg
the united states census bureau estimates that the population of louisiana was 4 670 724 on july 1 2015 a 3 03 increase since the 2010 united states census as of july 2005 prior to the landfall of hurricanes katrina and rita louisiana has an estimated population of 4 670 724 which is an increase of 21 048 or 0 4 from the prior year and an increase of 137 352 or 3 03 since 2010 this includes a natural increase since the last census of 129 889 people that is 350 818 births minus 220 929 deaths and a decrease due to net migration of 69 373 people out of the state immigration from outside the united states resulted in a net increase of 20 174 people and migration within the country produced a net loss of 89 547 people the population density of the state is 104 9 people per square mile the center of population of louisiana is located in pointe coupee parish in the city of new roads according to the 2000 u s census 14 7 of the population aged 5 and older speak french or cajun french at home while 1 5 speak spanish
according to the u s census bureau as of 2015 the state of oklahoma has an estimated population of 3 911 338 which is an increase of 159 987 or 4 26 since the year 2010 oklahoma is the 28 th most populous state in the united states
the demographics of venezuela are the condition and overview of venezuela s peoples demographic topics include basic education health and population statistics as well as identified racial and religious affiliations the venezuelan people comprise a combination of heritages the historically present amerindians spanish colonists and african slaves have all contributed to varying degrees later waves of european groups italians portuguese and germans migrated to venezuela in the 20 th century influencing many aspects of venezuelan life including its culture language food and music about 51 6 of the population is mestizo while 43 6 are white of european ancestry and or middle eastern ancestry another 3 7 is black african while 2 7 is of full amerindian ancestry and 1 0 other races principally asian people three amerindian tribes located in the country are the wayuu located in the west in zulia state and the timoto cuicas also in the west in mérida state in the andes about 85 of the population live in urban areas in the northern portion of the country and currently resides in the urban conglomerations caracas maracay maracaibo valencia etc that are concentrated in venezuela s northern coastal mountain strip nearly half of venezuela s geographic area lies south of the orinoco river however this region contains only 5 of the venezuelan population the world factbook 2011 estimate puts venezuela s total population at 27 635 743 inhabitants additionally over the past five years venezuelan society s general age structure has been trending towards the homologous structure found in cuba western europe japan and other healthy and rapidly aging societies notably there has been a significant increase in the proportion and gross numbers of elderly venezuelans aged 65 and up as well as a corresponding drop in the total fertility
a demyelinating disease is any disease of the nervous system in which the myelin sheath of neurons is damaged this damage impairs the conduction of signals in the affected nerves in turn the reduction in conduction ability causes deficiency in sensation movement cognition or other functions depending on which nerves are involved some demyelinating diseases are caused by genetics some by infectious agents some by autoimmune reactions and some by unknown factors organophosphates a class of chemicals which are the active ingredients in commercial insecticides such as sheep dip weed killers and flea treatment preparations for pets etc will also demyelinate nerves neuroleptics can also cause demyelination demyelinating diseases are traditionally classified in two kinds demyelinating myelinoclastic diseases and demyelinating leukodystrophic diseases in the first group a normal and healthy myelin is destroyed by a toxic chemical or autoimmune substance in the second group myelin is abnormal and degenerates the second group was denominated dysmyelinating diseases by poser in the most known example multiple sclerosis there is good evidence that the body s own immune system is at least partially responsible acquired immune system cells called t cells are known to be present at the site of lesions other immune system cells called macrophages and possibly mast cells as well also contribute to the damage some demyelinating diseases are caused by genetics some by infectious agents some by autoimmune reactions some by exposure to chemical agents and some by unknown factors vitamin b 12 deficiency can cause demyelination
in phonetics denasalization is the loss of nasal airflow in a nasal sound such as a nasal consonant or a nasal vowel that may be due to speech pathology but also occurs when the sinuses are blocked from a common cold in which case it is called a nasal voice the latter is not a linguistic term the symbol in the extended ipa is ⟨ ◌ ͊ ⟩ when one speaks with a cold the nasal passages still function as a resonant cavity so a denasalized nasal m͊ does not sound like a voiced oral stop b and a denasalized vowel a͊ does not sound like an oral vowel a however there are cases of historical or allophonic denasalization that have produced oral stops in some languages with nasal vowels such as paicĩ nasal consonants may only occur before nasal vowels but before oral vowels prenasalized stops are found this allophonic variation is likely to be from a historical process of partial denasalization similarly several languages around puget sound underwent a process of denasalization about one century ago except in special speech registers such as baby talk the nasals m n became the voiced stops b d it appears from historical records that there was an intermediate stage when the stops were prenasalized stops ᵐb ⁿd or poststopped nasals mᵇ nᵈ something similar is currently happening with word initial nasals in korean in some contexts m is neither m nor b but m͊
a dendritic spine or spine is a small membranous protrusion from a neuron s dendrite that typically receives input from a single axon at the synapse dendritic spines serve as a storage site for synaptic strength and help transmit electrical signals to the neuron s cell body most spines have a bulbous head the spine head and a thin neck that connects the head of the spine to the shaft of the dendrite the dendrites of a single neuron can contain hundreds to thousands of spines in addition to spines providing an anatomical substrate for memory storage and synaptic transmission they may also serve to increase the number of possible contacts between neurons
denervation is any loss of nerve supply regardless of the cause if the nerves lost to denervation are part of the neuronal communication to a specific function in the body then altered or a loss of physiological functioning can occur denervation can be caused by injury or be a symptom of a disorder like als and post polio syndrome additionally it can be a useful surgical technique to alleviate major negative symptoms such as in renal denervation denervation can have many harmful side effects such as increased risk of infection and tissue dysfunction
denervation supersensitivity is the sharp increase of sensitivity of post synaptic membranes to a chemical transmitter after denervation it is a compensatory change mechanism cause of denervative supersentivity is unknown part of answer is that the number of receptors in the post synaptic membrane of effector cells increases when norepinephrine or acetylcholine is no longer released at synapse aprocess called upregulation of receptor therefore when a dose of hormone is now injected into the circulatory blood the effector reaction is vastly enhanced
dengue fever is a mosquito borne tropical disease caused by the dengue virus symptoms typically begin three to fourteen days after infection this may include a high fever headache vomiting muscle and joint pains and a characteristic skin rash recovery generally takes two to seven days in a small proportion of cases the disease develops into the life threatening dengue hemorrhagic fever resulting in bleeding low levels of blood platelets and blood plasma leakage or into dengue shock syndrome where dangerously low blood pressure occurs dengue is spread by several species of mosquito of the aedes type principally a aegypti the virus has five different types infection with one type usually gives lifelong immunity to that type but only short term immunity to the others subsequent infection with a different type increases the risk of severe complications a number of tests are available to confirm the diagnosis including detecting antibodies to the virus or its rna a novel vaccine for dengue fever has been approved in three countries but it is not yet commercially available prevention is by reducing mosquito habitat and limiting exposure to bites this may be done by getting rid of or covering standing water and wearing clothing that covers much of the body treatment of acute dengue is supportive and includes giving fluid either by mouth or intravenously for mild or moderate disease for more severe cases blood transfusion may be required about half a million people require admission to hospital a year nonsteroidal anti inflammatory drug nsaids such as ibuprofen should not be used dengue has become a global problem since the second world war and is common in more than 110 countries each year between 50 and 528 million people are infected and approximately 10 000 to 20 000 die the earliest descriptions of an outbreak date from 1779 its viral cause and spread were understood by the early 20 th century apart from eliminating the mosquitoes work is ongoing for medication targeted directly at the virus
dengue virus denv is the cause of dengue fever it is a mosquito borne single positive stranded rna virus of the family flaviviridae genus flavivirus five serotypes of the virus have been found all of which can cause the full spectrum of disease nevertheless scientists are finding their understanding of dengue virus may be simplistic as rather than distinct antigenic groups there appears to be a continuum this same study identified 47 strains of dengue virus additionally coinfection with and lack of rapid tests for zika virus and chikungunya complicate matters in real world infections its genome is about 11000 bases of positive sense single stranded rna ssrna that codes for three structural proteins capsid protein c membrane protein m envelope protein e and seven nonstructural proteins ns 1 ns 2 a ns 2 b ns 3 ns 4 a ns 4 b ns 5 it also includes short non coding regions on both the 5 and 3 ends
dennie – marfan syndrome is a syndrome in which there is association of spastic paraplegia of the lower limbs and mental retardation in children with congenital syphilis both sexes are affected and the onset of the disease can be acute or insidious with slow progression from weakness to quadriplegia epilepsy cataract and nystagmus may be also be found the syndrome was described by charles clayton dennie in 1929 and antoine marfan in 1936
dens evaginatus is a condition found in teeth where the outer surface appears to form an extra bump or cusp premolars are more likely to be affected than any other tooth this may be seen more frequently in asians but almost exclusively in down syndrome the pulp of the tooth may extend into the dens evaginatus there is a risk of the dens evaginatus chipping off in normal function hence this condition requires monitoring as the tooth can lose its blood and nerve supply as a result and may need root canal treatment
dens invaginatus also known as dens in dente tooth within a tooth is a condition found in teeth where the outer surface folds inward there are coronal and radicular forms with the coronal form being more common dens invaginatus is a malformation of teeth most likely resulting from an infolding of the dental papilla during tooth development or invagination of all layer of the enamel organ in dental papillae affected teeth show a deep infolding of enamel and dentine starting from the foramen coecum or even the tip of the cusps and which may extend deep into the root teeth most affected are maxillary lateral incisors and bilateral occurrence is not uncommon the malformation shows a broad spectrum of morphologic variations and frequently results in early pulp necrosis root canal therapy may present severe problems because of the complex anatomy of the teeth aetiology prevalence classification and therapeutic considerations including root canal therapy apical surgery and prevention of pulpal involvement are reviewed etiology 1 increased localised pressure 2 focal growth retardation and stimulation types 1 coronal 2 radicular types type 1 that is confined to the crowntype 2 extend below cej and ends in a blind sac that may or may not communicate with adjacent dental pulptype 3 extend to the root and perforate in the apex or lateral radicular area without communicating the pulp
dent s disease or dent disease is a rare x linked recessive inherited condition that affects the proximal renal tubules of the kidney it is one cause of fanconi syndrome and is characterized by tubular proteinuria excess calcium in the urine formation of calcium kidney stones nephrocalcinosis and chronic kidney failure dent s disease is often used to describe an entire group of familial disorders including x linked recessive nephrolithiasis with kidney failure x linked recessive hypophosphatemic rickets and both japanese and idiopathic low molecular weight proteinuria about 60 of patients have mutations in the clcn 5 gene dent 1 which encodes a kidney specific chloride proton antiporter and 15 of patients have mutations in the ocrl 1 gene dent 2
a dental abscess also termed a dentoalveolar abscess tooth abscess or root abscess is a localized collection of pus associated with a tooth the most common type of dental abscess is a periapical abscess and the second most common is a periodontal abscess in a periapical abscess usually the origin is a bacterial infection that has accumulated in the soft often dead pulp of the tooth this can be caused by tooth decay broken teeth or extensive periodontal disease or combinations of these factors a failed root canal treatment may also create a similar abscess a dental abscess is a type of odontogenic infection although commonly the latter term is applied to an infection which has spread outside the local region around the causative tooth
dental avulsion is the complete displacement of a tooth from its socket in alveolar bone owing to trauma the treatment for permanent teeth consists of replantation immediately if possible deciduous teeth should not be replanted due to the risk of damaging the permanent tooth germ immediate replantation ensures the best possible prognosis but is not always possible since more serious injuries may be present studies have shown that teeth that are protected in a physiologically ideal media can be replanted within 15 minutes to one hour after the accident with good prognosis the success of delayed replantation depends on the vitality of the cells remaining on the root surface in normal conditions a tooth is connected to the socket by means of the periodontal ligament when a tooth is knocked out that ligament stretches and splits in half maintaining the vitality of the cells that remain attached to the root surface is the key to success following replantation years ago it was thought that the key to maintaining root cell vitality was keeping the knocked out tooth wet thus giving rise to storage media recommendations such as water the mouth and milk recent research has shown that one of the key elements for maintaining vitality is storing the tooth in an environment that closely resembles the original socket environment this environment is one that has the proper osmolality cell pressure ph nutritional metabolites and glucose there are scientifically designed storage media that provide this environment these storage media are now available in retail products use of devices that incorporate the ideal storage media and protective apparatuses have increased the success rate of replanted knocked out teeth to over 90 when used within sixty minutes of the accident
dental barotrauma is a condition in which barometric pressure changes in the external environment cause damage to the dentition the problem can occur owing to a miniature void within a filled tooth it is technically difficult to completely prevent void spaces occurring when placing a filling and carrying out root canal treatment according to boyle s law when the external pressure rises or falls the trapped air within the void will attempt to expand or contract the stresses this places on the tooth structure can cause pain or rarely fracturing of the tooth structure typically this is seen in scuba divers or aviators who experience pressure changes in the course of their activity identifying the pain during a pressure change is a diagnostic indicator for the clinician treatment involves removing the void space by carefully replacing the offending restoration repeating the endodontic treatment or removing the tooth
dental caries also known as tooth decay cavities or caries is a breakdown of teeth due to activities of bacteria the cavities may be a number of different colors from yellow to black symptoms may include pain and difficulty with eating complications may include inflammation of the tissue around the tooth tooth loss and infection or abscess formation the cause of caries is bacterial breakdown of the hard tissues of the teeth enamel dentin and cementum this occurs due to acid made from food debris or sugar on the tooth surface simple sugars in food are these bacteria s primary energy source and thus a diet high in simple sugar is a risk factor if mineral breakdown is greater than build up from sources such as saliva caries results risk factors include conditions that result in less saliva such as diabetes mellitus sjogren s syndrome and some medications medications that decrease saliva production include antihistamines and antidepressants caries is also associated with poverty poor cleaning of the mouth and receding gums resulting in exposure of the roots of the teeth prevention includes regular cleaning of the teeth a diet low in sugar and small amounts of fluoride brushing the teeth twice per day and flossing between the teeth once a day is recommended by many fluoride may be from water salt or toothpaste among other sources treating a mother s dental caries may decrease the risk in her children by decreasing the numbers of certain bacteria screening can result in earlier detection depending on the extent of destruction various treatments can be used to restore the tooth to proper function or the tooth may be removed there is no known method to grow back large amounts of tooth the availability of treatment is often poor in the developing world paracetamol acetaminophen or ibuprofen may be taken for pain worldwide approximately 2 43 billion people 36 of the population have dental caries in their permanent teeth the world health organization estimates that nearly all adults have dental caries at some point in time in baby teeth it affects about 620 million people or 9 of the population they have become more common in both children and adults in recent years the disease is most common in the developed world due to greater simple sugar consumption and less common in the developing world caries is latin for rottenness
dental fluorosis also termed mottled enamel is an extremely common disorder characterized by hypomineralization of tooth enamel caused by ingestion of excessive fluoride during enamel formation it appears as a range of visual changes in enamel causing degrees of intrinsic tooth discoloration and in some cases physical damage to the teeth the severity of the condition is dependent on the dose duration and age of the individual during the exposure the very mild and most common form of fluorosis is characterized by small opaque paper white areas scattered irregularly over the tooth covering less than 25 of the tooth surface in the mild form of the disease these mottled patches can involve up to half of the surface area of the teeth when fluorosis is moderate all of the surfaces of the teeth are mottled and teeth may be ground down and brown stains frequently disfigure the teeth severe fluorosis is characterized by brown discoloration and discrete or confluent pitting brown stains are widespread and teeth often present a corroded looking appearance people with fluorosis are relatively resistant to dental caries tooth decay caused by bacteria although they may be of cosmetic concern in moderate to severe fluorosis teeth are physically damaged
dental subluxation is a traumatic injury in which the tooth has increased mobility i e is loosened but has not been displaced from its original site in the jawbone
dentatorubral pallidoluysian atrophy drpla is an autosomal dominant spinocerebellar degeneration caused by an expansion of a cag repeat encoding a polyglutamine tract in the atrophin 1 protein it is also known as haw river syndrome and naito oyanagi disease although this condition was perhaps first described by smith et al in 1958 and several sporadic cases have been reported from western countries this disorder seems to be very rare except in japan there are at least eight neurodegenerative diseases that are caused by expanded cag repeats encoding polyglutamine polyq stretches see trinucleotide repeat disorder the expanded cag repeats create an adverse gain of function mutation in the gene products of these diseases drpla is most similar to huntington s disease
a dentigerous cyst or follicular cyst is an odontogenic cyst thought to be of developmental origin associated with the crown of an unerupted or partially erupted tooth the cyst cavity is lined by epithelial cells derived from the reduced enamel epithelium of the tooth forming organ regarding its pathogenesis it has been suggested that the pressure exerted by an erupting tooth on the follicle may obstruct venous flow inducing accumulation of exudate between the reduced enamel epithelium and the tooth crown in addition to the developmental origin some authors have suggested that periapical inflammation of non vital deciduous teeth in proximity to the follicles of unerupted permanent successors may be a factor for triggering this type of cyst formation histologically a normal dental follicle is lined by enamel epithelium whereas a dentigerous cyst is lined by non keratinized stratified squamous epithelium since the dentigerous cyst develops from follicular epithelium it has more potential for growth differentiation and degeneration than a radicular cyst occasionally the wall of a dentigerous cyst may give rise to a more ominous mucoepidermoid carcinoma due to the tendency for dentigerous cysts to expand rapidly they may cause pathological fractures of jaw bones on fine needle aspiration thin straw colored fluid is seen the usual radiographic appearance is that of a well demarcated radiolucent lesion attached at an acute angle to the cervical area of an unerupted tooth the border of the lesion may be radiopaque the radiographic differentiation between a dentigerous cyst and a normal dental follicle is based merely on size radiographically a dentigerous cyst should always be differentiated from a normal dental follicle dentigerous cysts are the most common cysts with this radiographic appearance radiographically the cyst appears unilocular with well defined margins and often sclerotic borders but sometimes it may be multilocular in appearance and may also have a continuous cystic membrane infected cysts show ill defined margins follicular space more than 3 mm is to be considered a dentigerous cyst radiographically there are three types of dentigerous cyst namely the central type lateral type and the circumferential type the most common location of dentigerous cysts are the mandibular 3 rd molars and the maxillary canines and they rarely involve deciduous teeth and are occasionally associated with odontomes a dentigerous cyst is often treated by excision of the cyst along with the extraction of the assosciated tooth in case of a large cyst marsupialization is done
dentin dysplasia is a genetic disorder of teeth commonly exhibiting an autosomal dominant inheritance it is characterized by presence of normal enamel but atypical dentin with abnormal pulpal morphology there are two types type i is the radicular type and type ii is the coronal type in the radicular type the roots of teeth are shorter than normal and the pulp chamber may be nearly gone the pulp chamber is sometimes described as having a crescent shaped appearance in the coronal type the pulps are enlarged and are described as having a thistle tube appearance in permanent dentition in the deciduous dentition coronal dentin dysplasia bears a resemblance to dentinogenesis imperfecta type ii radiographic features type 1 roots are short blunt and conical in deciduous teeth pulp chambers and root canals are completely obliterated while in permanent they may be crescent shaped type 2 the pulp chamber of the deciduous teeth become completely obliterated the permanent teeth displays large pulp chamber in the coronal portion of the tooth referred to as thistle tube appearance pulp stones may be found histologic features type 1 normal dentinal tubule formation is blocked and new dentin forms around obstacles known as lava flowing around boulders
dentin hypersensitivity abbreviated to dh or dhs and also termed sensitive dentin dentin sensitivity cervical sensitivity and cervical hypersensitivity is dental pain which is sharp in character and of short duration arising from exposed dentin surfaces in response to stimuli typically thermal evaporative tactile osmotic chemical or electrical and which cannot be ascribed to any other dental disease a degree of dentin sensitivity is normal but pain is not usually experienced in everyday activities like drinking a cooled drink therefore although the terms dentin sensitivity and sensitive dentin are used interchangeably to refer to dental hypersensitivity the latter term is the most accurate
dentinogenesis imperfecta di is a genetic disorder of tooth development this condition is a type of dentin dysplasia that causes teeth to be discolored most often a blue gray or yellow brown color and translucent giving teeth an opalescent sheen teeth are also weaker than normal making them prone to rapid wear breakage and loss these problems can affect both primary deciduous teeth and permanent teeth this condition is inherited in an autosomal dominant pattern which means one copy of the altered gene in each cell is sufficient to cause the disorder dentinogenesis imperfecta affects an estimated 1 in 6 000 to 8 000 people
there is a lack of dental care in rural alaska because many alaska natives live in rural villages most of which are only accessible by boat or bush plane there are many programs to help alaska natives understand the importance of dental care while helping them to receive the professional care and guidance that is needed there are many problem issues within the rural alaska native population such as tooth disease to help with these health issues there are dentists as well as dental therapist aides who travel to these villages to perform care these programs are funded by the united states federal government and the alaska native corporations
dentomandibular sensorimotor dysfunction is a medical condition involving the mandible lower jaw upper three cervical neck vertebrae and the surrounding muscle and nerve areas there is a concentrated nerve center in this area called the trigeminal nucleus this major pathway of nerves controls pain signals from the teeth face head and neck and carries them to the brain dentomandibular sensorimotor dysfunction refers to a condition in which an individual experiences chronic pain or stiffness from these nerve inputs as a result of dental force imbalances
denture related stomatitis also termed denture sore mouth denture stomatitis chronic atrophic candidiasis candida associated denture induced stomatitis and denture associated erythematous stomatitis is a common condition where mild inflammation and redness of the oral mucous membrane occurs beneath a denture in about 90 of cases candida species are involved which are normally a harmless component of the oral microbiota in many people denture related stomatitis is the most common form of oral candidiasis a yeast infection of the mouth it is more common in elderly people and in those who wear a complete upper denture a denture which replaces all the upper teeth worn by someone with no natural teeth in their upper jaw denture related stomatitis is more likely to develop when the denture is left constantly in the mouth rather than removing it during sleep and when the denture is not cleaned regularly
the denver convergence vorticity zone dcvz is an orographically induced atmospheric phenomenon characterized by convergent winds east of the denver metropolitan area typically 50 to 100 km in length and oriented in a north south direction this meteorological feature was subject to academic scrutiny following a large outbreak of denver area tornadoes in 1981 and has been used to explain the propensity of the area to spawn landspout misocyclone and supercell mesocyclone tornadoes the dcvz is often associated with the denver cyclone effect although the denver cyclone is considered a distinct atmospheric phenomenon by some scientists
denys – drash syndrome dds or drash syndrome is a rare disorder or syndrome characterized by gonadal dysgenesis nephropathy and wilms tumor
deoxygenation is a chemical reaction involving the removal of oxygen atoms from a molecule the term also refers to the removal molecular oxygen o 2 from gases and solvents a step in air free technique and gas purifiers as applied to organic compounds deoxygenation is a component of fuels production as well a type of reaction employed in organic synthesis e g of pharmaceuticals
in software engineering dependency injection is a software design pattern that implements inversion of control for resolving dependencies a dependency is an object that can be used a service an injection is the passing of a dependency to a dependent object a client that would use it the service is made part of the client s state passing the service to the client rather than allowing a client to build or find the service is the fundamental requirement of the pattern dependency injection allows a program design to follow the dependency inversion principle the client delegates the responsibility of providing its dependencies to external code the injector the client is not allowed to call the injector code it is the injecting code that constructs the services and calls the client to inject them this means the client code does not need to know about the injecting code the client does not need to know how to construct the services the client does not need to know which actual services it is using the client only needs to know about the intrinsic interfaces of the services because these define how the client may use the services this separates the responsibilities of use and construction there are three common means for a client to accept a dependency injection setter interface and constructor based injection setter and constructor injection differ mainly by when they can be used interface injection differs in that the dependency is given a chance to control its own injection all require that separate construction code the injector take responsibility for introducing a client and its dependencies to each other
dependency theory is a subfield of database theory which studies implication and optimization problems related to logical constraints commonly called dependencies on databases the best known class of such dependencies are functional dependencies which form the foundation of keys on database relations another important class of dependencies are the multivalued dependencies a key algorithm in dependency theory is the chase and much of the theory is devoted to its study
dependent personality disorder dpd formerly known as asthenic personality disorder is a personality disorder that is characterized by a pervasive psychological dependence on other people this personality disorder is a long term condition in which people depend on others to meet their emotional and physical needs with only a minority achieving normal levels of independence the cause of dependent personality disorder is unknown ta study in 2012 estimated that between 55 and 72 of the risk of the condition is inherited from one s parents the difference between a dependent personality and a dependent personality disorder is somewhat subjective which makes diagnosis sensitive to cultural influences such as gender role expectations
in population dynamics depensation is the effect on a population such as a fish stock whereby due to certain causes a decrease in the breeding population mature individuals leads to reduced production and survival of eggs or offspring the causes may include predation levels rising per offspring given the same level of overall predator pressure or the allee effect particularly the reduced likelihood of finding a mate although depensation is often considered in relation to the population being harvested especially fish the actual level of harvesting by definition is not part of depensation
depersonalization disorder dpd also known as depersonalization derealization syndrome is a mental disorder in which the person has persistent or recurrent feelings of depersonalization and or derealization symptoms can be classified as either depersonalization or derealization depersonalization is described as feeling disconnected or estranged from one s body thoughts or emotions individuals experiencing depersonalization may report feeling as if they are an outside observer of their own thoughts or body and often report feeling a loss of control over their thoughts or actions in some cases individuals may be unable to accept their reflection as their own or they may have out of body experiences while depersonalization is a sense of detachment from one s self derealization is described as detachment from one s surroundings individuals experiencing derealization may report perceiving the world around them as foggy dreamlike surreal or visually distorted in addition to these depersonalization derealization disorder symptoms the inner turmoil created by the disorder can result in depression self harm low self esteem anxiety attacks panic attacks phobias etc it can also cause a variety of physical symptoms including chest pain blurry vision visual snow nausea and the sensation of pins and needles in one s arms or legs depersonalization derealization disorder is thought to be caused largely by severe traumatic lifetime events including childhood abuse accidents natural disasters war torture and bad drug experiences it is unclear whether genetics play a role however there are many neurochemical and hormonal changes in individuals with depersonalization disorder the disorder is typically associated with cognitive disruptions in early perceptual and attentional processes diagnostic criteria for depersonalization derealization disorder includes among other symptoms persistent or recurrent feelings of detachment from one s mental or bodily processes or from one s surroundings a diagnosis is made when the dissociation is persistent and interferes with the social and or occupational functions of daily life however accurate descriptions of the symptoms are hard to provide due to the subjective nature of depersonalization derealization and person s ambiguous use of language when describing these episodes in the dsm 5 it was combined with derealization disorder and renamed to depersonalization derealization disorder ddpd in the dsm 5 it remains classified as a dissociative disorder while in the icd 10 it is called depersonalization derealization syndrome and classified as a neurotic disorder although the disorder is an alteration in the subjective experience of reality it is not a form of psychosis as the person maintains the ability to distinguish between their own internal experiences and the objective reality of the outside world during episodic and continuous depersonalization the person can distinguish between reality and fantasy in other words their grasp on reality remains stable at all times while depersonalization derealization disorder was once considered rare lifetime experiences with the disorder occur in approximately 1 – 2 of the general population the chronic form of this disorder has a reported prevalence of 0 8 to 1 9 while these numbers may seem small depersonalization derealization experiences have been reported by a majority of the general population with varying degrees of intensity while brief episodes of depersonalization or derealization can be common in the general population the disorder is only diagnosed when these symptoms cause significant distress or impair social occupational or other important areas of functioning
depression storage capacity in soil science is the ability of a particular area of land to retain water in its pits and depressions thus preventing it from flowing depression storage capacity along with infiltration capacity is one of the main factors involved in horton overland flow whereby water volume surpasses both infiltration and depression storage capacity and begins to flow horizontally across land possibly leading to flooding and soil erosion the study of land s depression storage capacity is important in the fields of geology ecology and especially hydrology
depressive personality disorder also known as melancholic personality disorder is a controversial psychiatric diagnosis that denotes a personality disorder with depressive features originally included in the american psychiatric association s dsm ii depressive personality disorder was removed from the dsm iii and dsm iii r recently it has been reconsidered for reinstatement as a diagnosis depressive personality disorder is currently described in appendix b in the dsm iv tr as worthy of further study although no longer listed as a personality disorder the diagnosis is included under the section “ personality disorder not otherwise specified ” while depressive personality disorder shares some similarities with mood disorders such as dysthymia it also shares many similarities with personality disorders including avoidant personality disorder some researchers argue that depressive personality disorder is sufficiently distinct from these other conditions so as to warrant a separate diagnosis
depth perception is the visual ability to perceive the world in three dimensions 3 d and the distance of an object depth sensation is the corresponding term for animals since although it is known that animals can sense the distance of an object because of their ability to move accurately or to respond consistently according to that distance it is not known whether they perceive it in the same subjective way that humans do depth perception arises from a variety of depth cues these are typically classified into binocular cues that are based on the receipt of sensory information in three dimensions from both eyes and monocular cues that can be represented in just two dimensions and observed with just one eye binocular cues include stereopsis eye convergence disparity and yielding depth from binocular vision through exploitation of parallax monocular cues include size distant objects subtend smaller visual angles than near objects grain size and motion parallax
depurination is a chemical reaction of purine deoxyribonucleosides deoxyadenosine and deoxyguanosine and ribonucleosides adenosine or guanosine in which the β n glycosidic bond is hydrolytically cleaved releasing a nucleic base adenine or guanine respectively the second product of depurination of deoxyribonucleosides and ribonucleosides is sugar 2 ’ deoxyribose and ribose respectively more complex compounds containing nucleoside residues nucleotides and nucleic acids also suffer from depurination deoxyribonucleosides and their derivatives are substantially more prone to depurination than their corresponding ribonucleoside counterparts loss of pyrimidine bases cytosine and thymine occurs by a similar mechanism but at a substantially lower rate when depurination occurs with dna it leads to the formation of apurinic site and results in an alteration of the structure studies estimate that as many as 5 000 purines are lost this way each day in a typical human cell in cells one of the main causes of depurination is the presence of endogenous metabolites undergoing chemical reactions apurinic sites in double stranded dna are efficiently repaired by portions of the base excision repair ber pathway depurinated bases in single stranded dna undergoing replication can lead to mutations because in the absence of information from the complementary strand ber can add an incorrect base at the apurinic site resulting in either a transition or transversion mutation depurination is known to play a major role in cancer initiation hydrolytic depurination is one of the principal forms of damage to ancient dna in fossil or subfossil material since the base remains unrepaired this results in both loss of information the base sequence and difficulties in recovery and in vitro replication of the damaged molecule by the polymerase chain reaction
dequeísmo is a phenomenon in spanish grammar considered wrong in prescriptive works it is using de que instead of que as the complementizer introducing a verbal complement clause it can be seen as the opposite of queísmo which involves using que when de que is to be used for example me dijo de que estaba cansado he told me that he was tired is a case of dequeísmo since the prescriptive construction is me dijo que estaba cansado dequeísmo is considered peculiar to less educated speakers most likely as an instance of hypercorrection in the attempt to avoid queísmo or perhaps a conflation with the reflexive use which can sometimes be quite superficially similar me alegro de que seáis felices grammatically normal with a reflexive verb i am pleased me alegra de que seáis felices prescriptively incorrect non reflexive dequeísmo usually me alegra que seáis felices it pleases me
in psychiatry derailment also loosening of association asyndesis asyndetic thinking knight s move thinking or entgleisen is a thought disorder characterized by discourse consisting of a sequence of unrelated or only remotely related ideas the frame of reference often changes from one sentence to the next in a mild manifestation this thought disorder is characterized by slippage of ideas further and further from the point of a discussion derailment can often be manifestly caused by intense emotions such as euphoria or hysteria some of the synonyms given above loosening of association asyndetic thinking are used by some authors to refer just to a loss of goal discourse that sets off on a particular idea wanders off and never returns to it a related term is tangentiality — it refers to off the point oblique or irrelevant answers given to questions in some studies on creativity knight s move thinking while it describes a similarly loose association of ideas it is not considered a mental disorder or the hallmark of one it is sometimes used as a synonym for lateral thinking
derbices or derbikes persian دربیک ‌ ها ‎ ‎ were a small pocket of tribal people located at or around hyrcania which is an area located in the northern borders of the iranian plateau most of what history can recount of this tribe is from the writings of ctesias led by their leader amoraeus derbices led a rebellion against cyrus the great causing the mortal wounding of the king they are however eventually defeated by cyrus and incorporated into the persian empire it is critical to note that the account of derbices is basically the work of ctesias and offers one of the plausible versions by which cyrus the great is killed other plausible accounts include that of herodotus which revolves around the massagatae and various other versions including one by xenophon which states cyrus the great actually died peacefully at his palace regardless this article and derbices by association makes sense in the context of historical reportings of ctesias which according to at least a few historians is the most credible version along with that of herodotus since he cteias had been a long while in persia as a doctor
derealization or derealisation sometimes abbreviated as dr is an alteration in the perception or experience of the external world so that it seems unreal other symptoms include feeling as though one s environment is lacking in spontaneity emotional colouring and depth it is both a dissociative symptom of many conditions such as psychiatric and neurological disorders and a standalone disorder see below derealization is a subjective experience of unreality of the outside world while depersonalization is sense of unreality in one s personal self although most authors currently regard derealization surroundings and depersonalization self as independent constructs many do not want to separate derealization from depersonalization the main reason for this is nosological because these symptoms often co occur but there is another more philosophical reason the idea that the phenomenological experience of self others and world is one continuous whole thus feelings of unreality may blend in and the person may puzzle over deciding whether it is the self or the world that feels unreal to them chronic derealization may be caused by occipital – temporal dysfunction these symptoms are common in the population with a lifetime prevalence of up to 5 and 31 – 66 at the time of a traumatic event
dermabrasion is a type of surgical skin planing typically performed in a professional medical setting by a dermatologist or plastic surgeon trained specifically in this procedure dermabrasion has been practiced for many years before the advent of lasers and involves the controlled deeper abrasion wearing away of the upper to mid layers of the skin with any variety of strong abrasive devices including a wire brush diamond wheel or fraise sterilized sandpaper salt crystals or other mechanical means dermabrasion should not be confused with microdermabrasion which is a newer and non surgical cosmetic procedure performed by non physician personnel nurses estheticians medical assistants and most recently untrained individuals in their homes dermabrasion procedures are surgical invasive procedures that typically require a local anaesthetic often they are performed in surgical suites or in professional medical centers since the procedure can typically remove the top to deeper layers of the epidermis and extend into the reticular dermis there is always minor skin bleeding the procedure carries risks of scarring skin discoloration infections and facial herpes virus cold sore reactivation in aggressive dermabrasion cases there is often tremendous skin bleeding and spray during the procedure that has to be controlled with pressure afterward the skin is normally very red and raw looking depending on the level of skin removal with dermabrasion it takes an average of 7 – 30 days for the skin to fully heal re epithelialize often this procedure was performed for deeper acne scarring and deep surgical scars dermabrasion is rarely practiced currently and there are very few doctors who are trained and still perform this surgery dermabrasion has largely been replaced all over the world by newer and somewhat simpler technologies including lasers co 2 or erbium yag laser laser technologies carry the advantage of little to no bleeding and are often less operator dependent than dermabrasion the purpose of surgical dermabrasion is to help diminish the appearance of deeper scars and skin imperfections often the goal is to smooth the skin and in the process remove small scars as from acne uneven skin tone from scars or birthmarks sun damage tattoos age spots stretch marks or fine wrinkles dermabrasion is a mechanical surgical skin planing method which has remained popular partially because it may afford an overall lower cost affordable and may provide similar superior results as newer laser method for certain skin conditions
in dermatologic pathology a dermal cylindroma also dermal eccrine cylindroma and less specifically cylindroma is a benign adnexal tumor which occurs on the scalp and forehead multiple cylindromas may grow together in a hat like configuration sometimes referred to as a turban tumor cylindromas are uncommon dysplasias of skin appendages
dermal dendrocyte hamartoma is characterized by a rounded medallion like lesion on the upper trunk in which there is a proliferation of fusiform cd 34 factor xiiia positive cells in the mid and reticular dermis
dermatitis also known as eczema is a group of diseases that results in inflammation of the skin these diseases are characterized by itchiness red skin and a rash in cases of short duration there may be small blisters while in long term cases the skin may become thickened the area of skin involved can vary from small to the entire body dermatitis is a group of skin conditions that includes atopic dermatitis allergic contact dermatitis irritant contact dermatitis and stasis dermatitis the exact cause of dermatitis is often unclear cases are believed to often involve a combination of irritation allergy and poor venous return the type of dermatitis is generally determined by the person s history and the location of the rash for example irritant dermatitis often occurs on the hands of people who frequently get them wet allergic contact dermatitis however can occur following brief exposures to specific substances to which a person is sensitive treatment of atopic dermatitis is typically with moisturizers and steroid creams the steroid creams should generally be of mid to high strength and used for less than two weeks at a time as side effects can occur antibiotics may be required if there are signs of skin infection contact dermatitis is typically treated by avoiding the allergen or irritant antihistamines may be used to help with sleep and to decrease nighttime scratching dermatitis was estimated to affect 334 million people globally in 2013 atopic dermatitis is the most common type and generally starts in childhood in the united states it affects about 10 30 of people contact dermatitis is two times more common in females than males allergic contact dermatitis affects about 7 of people at some point in time irritant contact dermatitis is common especially among people who do certain jobs however exact rates are unclear
dermatitis gangrenosa also known as gangrene of the skin is a cutaneous condition caused by infection by clostridium resulting in a necrosis and sloughing of the skin
dermatitis herpetiformis dh or duhring s disease is a chronic blistering skin condition characterised by blisters filled with a watery fluid despite its name dh is neither related to nor caused by herpes virus the name means that it is a skin inflammation having an appearance similar to herpes dh was first described by louis adolphus duhring in 1884 a connection between dh and coeliac disease was recognised in 1967 although the exact causal mechanism is not known dh is a specific manifestation of coeliac disease the age of onset is usually about 15 40 but dh can also affect children and the elderly men and women are equally affected estimates of dh prevalence vary from 1 in 400 to 1 in 10000 it is most common in patients of northern european northern indian ancestry and is associated with the hla dq 2 haplotype along with coeliac disease and gluten sensitivity
dermatitis repens also known as acrodermatitis continua acrodermatitis perstans pustular acrodermatitis acrodermatitis continua of hallopeau acrodermatitis continua suppurativa hallopeau hallopeau s acrodermatitis hallopeau s acrodermatitis continua and dermatitis repens crocker is a rare sterile pustular eruption of the fingers and toes that slowly extends proximally
dermatochalasis is a medical condition defined as an excess of skin in the upper or lower eyelid also known as baggy eyes it may be either an acquired or a congenital condition it is generally treated with blepharoplasty
dermatofibrosarcoma protuberans dfsp is a very rare tumor it is a rare neoplasm of the dermis layer of the skin and is classified as a sarcoma there is only about one case per million per year dfsp is a fibrosarcoma more precisely a cutaneous soft tissue sarcoma in many respects the disease behaves as a benign tumor but in 2 – 5 of cases it can metastasize so it should be considered to have malignant potential it occurs most often in adults in their thirties it has been described congenitally in children and the elderly it accounts for approximately 2 – 6 of soft tissue sarcoma cancers
dermatographic urticaria also known as dermographism dermatographism or skin writing is a skin disorder and one of the most common types of urticaria affecting 4 – 5 of the population
a dermatomycosis is a skin disease caused by a fungus this excludes dermatophytosis examples of dermatomycoses are tinea and cutaneous candidiasis
dermatomyositis dm is a connective tissue disease related to polymyositis pm that is characterized by inflammation of the muscles and the skin while dm most frequently affects the skin and muscles it is a systemic disorder that may also affect the joints the esophagus the lungs and the heart in the united states the incidence of dm is estimated at 5 5 cases per million people
dermatopathia pigmentosa reticularis dpr also known as dermatopathia pigmentosa reticularis hyperkeratotica et mutilans dermatopathia pigmentosa reticularis hypohidotica et atrophica and dermatopathic pigmentosa reticularis is a rare autosomal dominant congenital disorder that is a form of ectodermal dysplasia dermatopathia pigmentosa reticularis is composed of the triad of generalized reticulate hyperpigmentation noncicatricial alopecia and onychodystrophy
in pathology dermatopathic lymphadenopathy also dermatopathic lymphadenitis is lymph node pathology due to skin disease
dermatophytids are fungus free disseminated skin lesions resulting from induced sensitization in patients with ringworm infections the most common dermatophytid is an inflammation in the hands resulting from a fungus infection of the feet dermatophytids normally disappear when the primary ringworm infection is treated dermatophytids may resemble erythema nodosum
dermatophytosis also known as ringworm is a fungal infection of the skin typically it results in a red itchy scaly circular rash hair loss may occur in the area affected symptoms begin four to fourteen days after exposure multiple areas can be affected at a given time about 40 types of fungi can cause ringworm they are typically of the trichophyton microsporum or epidermophyton type risk factors include using public showers contact sports such as wrestling excessive sweating contact with animals obesity and poor immune function ringworm can spread from other animals or between people diagnosis is often based on the appearance and symptoms it may be confirmed by either culturing or looking at a skin scraping under a microscope prevention is by keeping the skin dry not walking barefoot in public and not sharing personal items treatment is typically with antifungal creams such as clotrimazole or miconazole if the scalp is involved antifungals by mouth such as fluconazole may be needed up to 20 of the population may be infected by ringworm at any given time infections of the groin are more common in males while infections of the scalp and body occur equally in both sexes infections of the scalp are most common in children while infections of the groin are most common in the elderly description of ringworm date back to ancient history
dermatopolymyositis also called pm dm is a family of myositis disorders that includes polymyositis and dermatomyositis
dermatoses of pregnancy are the inflammatory skin diseases that are specific to women while they are pregnant while some use the term polymorphic eruption of pregnancy to cover these this term is a synonym used in the uk for pruritic urticarial papules and plaques of pregnancy which is the commonest of these skin conditions skin diseases seen during pregnancy include
dermatosis neglecta is a skin condition in which accumulation of sebum keratin sweat dirt and debris leads to a localized patch of skin discoloration or a wart like plaque it is caused by inadequate hygiene of a certain body part usually due to some form of disability or a condition that is associated with pain or increased sensitivity to touch hyperesthesia or immobility dermatosis neglecta typically develops several months after a disability or other affliction leads to improper cleaning patients may deny that negligence is the cause of the lesion even though it completely resolves on vigorous rubbing with alcohol swabs or water and soap which provides both diagnosis and treatment recognizing the diagnosis avoids unnecessary skin biopsies examples of case reports from the literature include a man who avoided washing the skin area surrounding an artificial pacemaker out of fear it might be damaged a woman who didn t clean the right side of her chest due to hyperesthesia following an amputation for breast cancer mastectomy a girl who was afraid to wash the area around an abdominal scar and a man with multiple fractures shoulder dislocation and radial nerve palsy which significantly reduced his mobility
dermatosis papulosa nigra dpn is a condition of many small benign skin lesions on the face a condition generally presenting on dark skinned individuals dpn is extremely common affecting up to 30 of black people in the us from a histological perspective dpn resembles seborrheic keratoses the condition may be cosmetically undesirable to some patients they should not be confused for leser trélat sign a sudden explosion of lesions due to a growing tumor
dermatothlasia is a cutaneous neurosis characterized by a person s uncontrollable desire to rub or pinch him herself to form bruised areas on the skin sometimes as a defense against pain elsewhere
dermocystidium is a genus of cyst forming parasitic protists of fish which are the causative agents of dermocystidiosis
a dermoid cyst is a teratoma of a cystic nature that contains an array of developmentally mature solid tissues it frequently consists of skin hair follicles and sweat glands while other commonly found components include clumps of long hair pockets of sebum blood fat bone nails teeth eyes cartilage and thyroid tissue as dermoid cysts grow slowly and contain mature tissue this type of cystic teratoma is nearly always benign in those rare cases wherein the dermoid cyst is malignant a squamous cell carcinoma usually develops in adults while infants and children usually present with an endodermal sinus tumor
dermoid sinus is a thought to be a genetic skin condition in dogs it is also known as pilonidal sinus however unlike pilonidal sinus in humans the dermoid sinus in dogs is a neural tube defect dermoid sinus is sometimes also confused with dermoid cyst a teratoma a dermoid sinus is rare in dogs and cats it can appear as single or multiple lumps on the dorsal midline the sinus is caused in the embryonic stage of development in normal development the neural tube from which the spine develops separates from the skin in the case of a dermoid sinus this separation has not fully taken place the result is that in some cases the dermoid sinus remains connected to the animal s spinal cord in other cases the sinus terminates in a blind sac that is less dangerous to remove histologically the dermoid sinus contains hair follicles sebaceous glands and sweat glands if the sinus becomes infected it can result in meningitis and myelitis symptoms of which are spinal pain rigidity and fever in serious cases the condition can be life threatening the dermoid sinus gene is believed by some to be recessive meaning that the animal must receive one defective gene from each parent in order to develop the condition where one parent carries the gene and the other does not the offspring remain carriers and can continue to pass the defective gene on to their offspring in turn others believe that the dermoid sinus condition is more appropriately characterized as polygenic involving multiple genes in any case because of the genetic nature of this potentially dangerous condition most breeders and veterinarians advise against breeding animals that have a dermoid sinus or have a parent that is known to carry the gene surgical excision is the only remedy for this condition with veterinary surgeons removing abnormal tissue and closing any connections to the spine in some cases regrowth of the sinus occurs a variety of tests such as a myelogram or a fistulogram may be undertaken to determine how deep the sinus goes other more basic tests such as a complete blood count biochemical profile and urinalysis can be performed to determine if infection or other problems exist computed tomography scans and magnetic resonance imaging may be undertaken to determine if neurological signs exist as a result of the sinus breeds known to be affected include rhodesian ridgeback and thai ridgeback in which it is hereditary kerry blue terriers shih tzus and boxers
dermoodontodysplasia is dental problems trichodysplasia and nail and skin problems
the description experience gap is a phenomenon in experimental behavioral studies of decision making the gap refers to the observed differences in people ’ s behavior depending on whether their decisions are made towards clearly outlined and described outcomes and probabilities or whether they simply experience the alternatives without having any prior knowledge of the consequences of their choices in both described and experienced choice tasks the experimental task usually involves selecting between one of two possible choices that lead to certain outcomes the outcome could be a gain or a loss and the probabilities of these outcomes vary of the two choices one is probabilistically safer than the other the other choice then offers a comparably improbable outcome the specific payoffs or outcomes of the choices in terms of the magnitude of their potential gains and losses varies from study to study
a description error or selection error is an error or more specifically a human error that occurs when a person performs the correct action on the wrong object due to insufficient specification of an action which would have led to a desired result this commonly happens when similar actions lead to different results a typical example is a panel with rows of identical switches where it is easy to carry out a correct action flip a switch on a wrong switch due to their insufficient differentiation this error can be very disorienting and usually causes a brief loss of situation awareness or automation surprise if noticed right away but much worse if it goes unnoticed it could cause more serious problems so allowances such as clearly highlighting a selected item should be made in interaction design donald norman describes the subject in his book the design of everyday things there he describes how user centered design can help account for human limitations that can lead to errors like description errors james reason also covers the subject in his book human error
desert dᵻˈzɜːrt in philosophy is the condition of being deserving of something whether good or bad
the desert night camouflage pattern is a two color grid camouflage pattern used by the united states military during the gulf war it was designed to aid soldiers in concealment from older generation enemy night vision devices nvds the pattern is now considered obsolete due to the increase in capability of foreign night vision devices during the first gulf war clothing sets in this pattern were issued to us troops as an over jacket with a removable insulating liner and over pants both being designed to be worn over the issued six color desert battle dress uniform during nighttime operations no night specific pattern has been created to replace this gear for nighttime use in a desert environment as advancements in infrared reflectance technology in first the desert camouflage uniform and finally the marine corps combat utility uniform and army combat uniform have eliminated the need for a separate nighttime overgarment
in a general sense the design load is the maximum amount of something a system is designed to handle or the maximum amount of something that the system can produce which are very different meanings for example a crane with a design load of 20 tons is designed to be able to lift loads that weigh 20 tons or less however when a failure could be catastrophic such as a crane dropping its load or collapsing entirely a factor of safety is necessary as a result the crane should lift about 2 to 5 tons at the most in structural design a design load is greater than the load which the system is expected to support this is because engineers incorporate a safety factor in their design in order to ensure that the system will be able to support at least the expected loads called specified loads despite any problems with construction materials etc that go unnoticed during construction a heater would have a general design load meaning the maximum amount of heat it can produce a bridge would have a specified load with the design load being determined by engineers and applied as a theoretical load intended to ensure the actual real world capacity of the specified load
designer stubble is a short growth of a man s facial hair that became popular in the 1980 s this style was worn and reinvented by singer george michael and actor don johnson and was adopted by many others several companies manufacture beard trimmers designed to maintain designer stubble which is also known as five o clock shadow
sexual desire discrepancy sdd is the difference between one s desired frequency of sexual intercourse and the actual frequency of sexual intercourse within a relationship among couples seeking sex therapy problems of sexual desire are the most commonly reported dysfunctions yet have historically been the most difficult to treat successfully sexual satisfaction in a relationship has a direct relationship with overall relationship satisfaction and relationship well being sexual desire and sexual frequency do not stem from the same domains sexual desire characterizes an underlying aspect of sexual motivation and is associated with romantic feelings while actual sexual activity and intercourse is associated with the development and advancement of a given relationship thus together sexual desire and sexual frequency can successfully predict the stability of a relationship while higher individual sexual desire discrepancies among married individuals may undermine overall relationship well being higher sdd scores for females may be beneficial for romantic relationships because those females have high levels of passionate love and attachment to their partner studies suggest that women with higher levels of desire relative to that of their partners may experience fewer relationship adjustment problems than women with lower levels of desire relative to their partners empirical evidence has shown that sexual desire is a factor that heavily influences couple satisfaction and relationship continuity which has been one of the main reasons for the interest in this research domain of human sexuality
desmin related myofibrillar myopathy is a subgroup of the myofibrillar myopathy diseases and is the result of a mutation in the gene that codes for desmin which prevents it from forming protein filaments instead forming aggregates of desmin and other proteins throughout the cell
in medicine desmoplasia is the growth of fibrous or connective tissue it is also called desmoplastic reaction to emphasize that it is secondary to an insult desmoplasia may occur around a neoplasm causing dense fibrosis around the tumor or scar tissue adhesions within the abdomen after abdominal surgery desmoplasia is usually only associated with malignant neoplasms which can evoke a fibrosis response by invading healthy tissue invasive ductal carcinomas of the breast often have a scirrhous stellate appearance caused by desmoplastic formations
in medicine a desmoplastic fibroma is a benign fibrous tumor of bone affecting children and young adults potentially resulting in cortical bone destruction it can also occur in the hand a famous occurrence of this particular form of the disease involved italo australian riccardo torresan in 2011 with 18 cm of femur needing to be removed with the now widely recognized method of aggressive curettage being employed
desmoplastic melanoma also known as a neurotropic melanoma or spindled melanoma is a rare cutaneous condition characterized by a deeply infiltrating type of melanoma with an abundance of fibrous matrix it usually occurs in the head and neck region of older people with sun damaged skin diagnosis can be difficult as it has a similar appearance to sclerosing melanocytic nevi as well as some nonmelanocytic skin lesions such as scars fibromas or cysts desmoplastic melanomas tend to recur locally with distant metastasis being less common
desmoplastic small round cell tumor is an aggressive and rare cancer that primarily occurs as masses in the abdomen other areas affected may include the lymph nodes the lining of the abdomen diaphragm spleen liver chest wall skull spinal cord large intestine small intestine bladder brain lungs testicles ovaries and the pelvis reported sites of metatastic spread include the liver lungs lymph nodes brain skull and bones the tumor is classified as a soft tissue sarcoma it is considered a childhood cancer that predominantly strikes boys and young adults the disease rarely occurs in females but when it does the tumors can be mistaken for ovarian cancer in dogs mast cell tumors are the most frequent round cell tumor
a desmoplastic trichoepithelioma is a cutaneous condition characterized by a solitary firm skin lesion on the face
desmosterolosis is a defect in cholesterol biosynthesis it results in an accumulation of desmosterol it has been associated with 24 dehydrocholesterol reductase
despeciation is the loss of a unique species of animal due to its combining with another previously distinct species it is the opposite of speciation and is much more rare it is similar to extinction in that there is a loss of a unique species but without the associated loss of a biological lineage
desquamation from latin desquamare meaning to scrape the scales off a fish also called skin peeling is the shedding of the outermost membrane or layer of a tissue such as the skin
desquamative gingivitis dg is an erythematous red desquamatous shedding and ulcerated appearance of the gums it is a descriptive term and can be caused by several different disorders
desquamative interstitial pneumonia is a form of idiopathic interstitial pneumonia featuring elevated levels of macrophages its name is derived from the former belief that these macrophages were pneumocytes that had desquamated it is associated with patients with a history of smoking treatment with methylprednisolone has been reported
the destruction of country houses in ireland was a phenomenon of the irish revolutionary period 1919 – 1923 which saw approximately 275 country houses deliberately burned down blown up or otherwise destroyed by the irish republican army ira the vast majority of the houses known in ireland as big houses belonged the anglo irish aristocracy of the protestant ascendancy although the houses of some roman catholic unionists and or suspected informers were also targeted although the practice by the ira of destroying country houses began in the irish war of independence most of the buildings were destroyed during the irish civil war 1922 – 23 today most of the targeted buildings are in ruins or have been demolished some were restored by their owners albeit often smaller in size or were later rebuilt and are now used for other purposes
the destruction of country houses in 20 th century britain was a phenomenon brought about by a change in social conditions during which a large number of country houses of varying architectural merit were demolished collectively termed by several authors the lost houses the final chapter in the history of these often now forgotten houses has been described as a cultural tragedy the british nobility had been demolishing their country houses since the 15 th century when comfort replaced fortification as an essential need for many demolishing and rebuilding their country homes became a lifelong hobby in particular during the 18 th century when it became fashionable to take the grand tour and return home with art treasures supposedly brought from classical civilizations during the 19 th century many houses were enlarged to accommodate the increasing armies of servants needed to create the famed country house lifestyle less than a century later this often meant they were of an unmanageable size in the early 20 th century the demolition accelerated while rebuilding largely ceased the demolitions were not confined to england but spread throughout britain by the end of the century even some of the new country houses by lutyens had been demolished there were a number of reasons social political and most importantly financial in rural areas of britain the loss of the country houses and their estates was tantamount to a social revolution well into the 20 th century it was common for the local squire to provide large scale employment housing and patronage to the local school church and a cottage hospital the big house was the bedrock of rural society since 1900 1 200 country houses have been demolished in england in scotland the figure is proportionally higher there 378 architecturally important country houses have been destroyed 200 of these since 1945 included in the destruction were works by robert adam including balbardie house and the monumental hamilton palace one firm charles brand of dundee demolished at least 56 country houses in scotland in the 20 years between 1945 and 1965 in england it has been estimated that one in six of all country houses were demolished during the 20 th century
the destruction of sites associated with early islam is an ongoing phenomenon that has occurred mainly in the hejaz region of western saudi arabia particularly around the holy cities of mecca and medina the demolition has focused on mosques burial sites homes and historical locations associated with the islamic prophet muhammad and many of the founding personalities of early islamic history in saudi arabia many of the demolitions have officially been part of the continued expansion of the masjid al haram at mecca and the prophet s mosque in medina and their auxiliary service facilities in order to accommodate the ever increasing number of muslims performing the pilgrimage hajj
desulfonylation reactions are chemical reactions leading to the removal of a sulfonyl group from organic compounds as the sulfonyl functional group is electron withdrawing methods for cleaving the sulfur carbon bonds of sulfones are typically reductive in nature olefination or replacement with hydrogen may be accomplished using reductive desulfonylation methods
detachment old french de from and at tach joining with a stake under international law is the formal permanent separation of and loss of sovereignty over some territory to another geo political entity either adjacent or non contiguous after world war i alsace and lorraine were a formal detachment from germany more often detachment occurs as a process within a country for example the creation of the federal district of columbia resulted from a detachment of territory from the state of maryland the removal of territory from a city or special district is a detachment within a country detachment is governed by the laws of the supervening entity detachment can be considered the opposite or reverse of annexation
in linguistics determiner spreading ds is the appearance of more than one determiner associated with a noun phrase usually marking an adjective as well as the noun itself the extra determiner has been called an adjectival determiner typical examples involve multiple occurrences of the definite article or definiteness marking such as is found in modern greek 1 determiner spreading in greek is not obligatory and it contrasts with a non spreading example 2 researchers have tried to elucidate the nature of the difference both syntactically and semantically between these two kinds of structures one widely accepted conclusion is that the determiner spreading structure requires a kind of focus usually contrastive on the adjective so that 1 is appropriate as where i bought the red dress not the blue one would be and that the adjective in question must be intersective so no determiner spreading is possible in the equivalent of the former minister greek o proigoumenos o ipurgos and that loose compounds cannot participate in this 3 when determiner spreading involves the definite article such noun phrases are sometimes called polydefinites determiner spreading is also found in albanian and in certain germanic varieties in some dialects of swedish it has also been reported to occur with the indefinite article
determining the number of clusters in a data set a quantity often labeled k as in the k means algorithm is a frequent problem in data clustering and is a distinct issue from the process of actually solving the clustering problem for a certain class of clustering algorithms in particular k means k medoids and expectation – maximization algorithm there is a parameter commonly referred to as k that specifies the number of clusters to detect other algorithms such as dbscan and optics algorithm do not require the specification of this parameter hierarchical clustering avoids the problem altogether the correct choice of k is often ambiguous with interpretations depending on the shape and scale of the distribution of points in a data set and the desired clustering resolution of the user in addition increasing k without penalty will always reduce the amount of error in the resulting clustering to the extreme case of zero error if each data point is considered its own cluster i e when k equals the number of data points n intuitively then the optimal choice of k will strike a balance between maximum compression of the data using a single cluster and maximum accuracy by assigning each data point to its own cluster if an appropriate value of k is not apparent from prior knowledge of the properties of the data set it must be chosen somehow there are several categories of methods for making this decision
developmental coordination disorder dcd also known as developmental dyspraxia or quite simply dyspraxia is a chronic neurological disorder beginning in childhood that can affect planning of movements and co ordination as a result of brain messages not being accurately transmitted to the body developmental coordination disorder is diagnosed in the absence of other neurological impairments like cerebral palsy muscular dystrophy multiple sclerosis or parkinson s disease it affects 5 to 6 percent of school aged children this disorder progresses to adulthood therefore making it a lifelong condition
developmental disability is a diverse group of chronic conditions that are due to mental or physical impairments developmental disabilities cause individuals living with them many difficulties in certain areas of life especially in language mobility learning self help and independent living developmental disabilities can be detected early on and do persist throughout an individual s lifespan developmental disability that affects all areas of a child s development is sometimes referred to as global developmental delay most common developmental disabilities fragile x syndrome fxs is thought to cause autism and intellectual disability usually among boys down syndrome is a condition in which people are born with an extra copy of chromosome 21 normally a person is born with two copies of chromosome 21 however if they are born with down syndrome they have an extra copy of this chromosome this extra copy affects the development of the body and brain causing physical and mental challenges for the individual pervasive developmental disorders pdd are a group of developmental disabilities that can cause significant social communication and behavioral challenges fetal alcohol spectrum disorders fasd are a group of conditions that can occur in a person whose mother drank alcohol during pregnancy fasds are 100 preventable if a woman does not drink alcohol during pregnancy cerebral palsy cp is a group of disorders that affect a person ’ s ability to move and maintain balance and posture cp is the most common motor disability in childhood intellectual disability also sometimes proscriptively known as mental retardation is defined as an iq below 70 along with limitations in adaptive functioning and onset before the age of 18 years
developmental disorders is a group of psychiatric conditions originating in childhood that involve serious impairment in different areas there are several ways of using this term the most narrow concept is used in the category specific disorders of psychological development in the icd 10 these disorders comprise language disorders learning disorders motor disorders and autism spectrum disorders in broader definitions adhd is included and the term used is neurodevelopmental disorders yet others include antisocial behavior and schizophrenia that begins in childhood and continues through life however these two latter conditions are not as stable as the other developmental disorders and there is not the same evidence of a shared genetic liability developmental disorders are present from early life they usually improve as the child grows older but they also entail impairments that continue through adult life there is a strong genetic component and more males are afflicted than females
a deviancy amplification spiral also called deviance amplification is a media hype phenomenon defined by media critics as a cycle of increasing numbers of reports on a category of antisocial behaviour or some other undesirable event leading to a moral panic
in financial mathematics a deviation risk measure is a function to quantify financial risk and not necessarily downside risk in a different method than a general risk measure deviation risk measures generalize the concept of standard deviation
the devil s footprints were a phenomenon that occurred in february 1855 around the exe estuary in east devon and south devon england after a heavy snowfall trails of hoof like marks appeared overnight in the snow covering a total distance of some 40 to 100 miles the footprints were so called because some people believed that they were the tracks of satan as they were allegedly made by a cloven hoof many theories have been put forward to explain the incident and some aspects of its veracity have also been called into question
devil facial tumour disease dftd is an aggressive non viral transmissible parasitic cancer among tasmanian devils the first official case of dftd was described in 1996 in australia in the subsequent decade the disease ravaged tasmania s wild devils with estimates of decline ranging from 20 to as much as 50 of the devil population across over 65 of the state affected high density populations suffer up to 100 mortality in 12 – 18 months the disease has mainly been concentrated in tasmania s eastern half visible signs of dftd begin with lesions and lumps around the mouth these develop into cancerous tumours that may spread from the face to the entire body devils usually die within six months from organ failure secondary infection or metabolic starvation as the tumours interfere with feeding dftd affects males and females equally at present the population has dwindled by 70 since 1996 as of 2010 80 of population is infected the most plausible route of transmission is through biting particularly when canine teeth come into direct contact with the diseased cells other modes of transmission include but are not limited to the ingesting of an infected carcass or the sharing of food both of which involve an allogeneic transfer of cells between unrelated individuals six females have been found with a partial immunity breeding in captivity has begun in an attempt to save the population
devon colic was a condition that affected people in the english county of devon during parts of the 17 th and 18 th centuries before it was discovered to be lead poisoning the first written account of the colic comes from 1655 symptoms began with severe abdominal pains and the condition was occasionally fatal cider is the traditional drink of devonians and the connection between the colic and cider drinking had been observed for many years the condition was commonly attributed to the acidity of the beverage william musgrave s publication de arthritide symptomatica 2 nd edn 1715 included the first scientific description of devonshire colic – it was later referred to by john huxham and sir george baker however the precise cause was not discovered until the 1760 s when dr george baker put forward the hypothesis that poisoning from lead in cider was to blame he observed that the symptoms of the colic were similar to those of lead poisoning he pointed out that lead was used in the cider making process both as a component of the cider presses and in the form of lead shot which was used to clean them he also conducted chemical tests to demonstrate the presence of lead in devon apple juice the publication of his results met with some hostile reaction from cider manufacturers keen to defend their product once baker s conclusions became accepted and the elimination of lead from the cider presses was undertaken the colic declined by 1818 baker s son reported that it was hardly known to exist in devon
the dew point depression t td is the difference between the temperature and dew point temperature at a certain height in the atmosphere for a constant temperature the smaller the difference the more moisture there is and the higher the relative humidity in the lower troposphere more moisture small dew point depression results in lower cloud bases and lifted condensation levels lcl lcl height is an important factor modulating severe thunderstorms one example concerns tornadogenesis with tornadoes most likely if the dew point depression is 20 ° f 11 ° c or less and the likelihood of large intense tornadoes increasing as dew point depression decreases lcl height also factors in downburst and microburst activity conversely instability is increased when there is a mid level dry layer large dew point depression known as a dry punch which is favorable for convection if the lower layer is buoyant as it measures moisture content in the atmosphere the dew point depression is also an important indicator in agricultural and forest meteorology particularly in predicting wildfires
a dewbow is an optical effect similar to a rainbow where the dewdrops reflect and disperse sunlight producing all the colours in the visible spectrum
dexippus of cos also called dioxippus 4 th century bc a greek physician of cos who was one of the pupils of the celebrated hippocrates and lived in the 4 th century bc hecatomnus prince of caria 385 377 bc sent for him to cure his sons mausolus and pixodarus of a dangerous illness which he undertook to do upon condition that hecatomnus should cease from waging war against his country he wrote some medical works of which nothing but the titles remain he was blamed by erasistratus for his excessive severity in restricting the quantity of drink allowed to his patients he is quoted by plutarch and aulus gellius in the controversy that was maintained among some of the ancient physicians as to whether the drink passed down the windpipe or the gullet
dextro transposition of the great arteries d transposition of the great arteries dextro tga or d tga sometimes also referred to as complete transposition of the great arteries is a birth defect in the large arteries of the heart the primary arteries the aorta and the pulmonary artery are transposed it is called a cyanotic congenital heart defect chd because the newborn infant turns blue from lack of oxygen in segmental analysis this condition is described as ventriculoarterial discordance with atrioventricular concordance or just ventriculoarterial discordance d tga is often referred to simply as transposition of the great arteries tga however tga is a more general term which may also refer to levo transposition of the great arteries l tga another term commonly used to refer to both d tga and l tga is transposition of the great vessels tgv although this term might have an even broader meaning than tga
dextrocardia from latin dexter meaning right and greek kardia meaning heart is a rare congenital defect in which the apex of the heart is located on the right side of the body there are two main types of dextrocardia dextrocardia of embryonic arrest also known as isolated dextrocardia and dextrocardia situs inversus dextrocardia situs inversus is further divided
dhat syndrome sanskrit धातु दोष iast dhātu doṣa is a condition found in the cultures of the indian subcontinent in which male patients report that they suffer from premature ejaculation or impotence and believe that they are passing semen in their urine the condition has no known organic etiology in traditional hindu spirituality semen is described as a vital fluid the discharge of this vital fluid either through sex or masturbation is associated with marked feelings of anxiety and dysphoria often the patient describes the loss of a whitish fluid while passing urine at other times marked feelings of guilt associated with what the patient assumes is excessive masturbation are noted this is based on an old hindu belief that it takes forty drops of blood to create a drop of bone marrow and forty drops of bone marrow to create a drop of sperm many doctors view dhat as a folk diagnostic term used in india to refer to anxiety and hypochondriacal concerns associated with the discharge of semen with discoloration of the urine and feelings of weakness and exhaustion dhat is thought to be a culture bound syndrome similar to jiryan south east asia prameha sri lanka and shen k uei china dhat syndrome might be related to other post orgasmic diseases such as post coital tristesse pct postorgasmic illness syndrome pois and sexual headache
the di pi methane rearrangement is a photochemical reaction of a molecular entity that contains two π systems separated by a saturated carbon atom a 1 4 diene or an allyl substituted aromatic ring to form an ene or aryl substituted cyclopropane the rearrangement reaction formally amounts to a 1 2 shift of one ene group in the diene or the aryl group in the allyl aromatic analog and bond formation between the lateral carbons of the non migrating moiety di pi methane rearrangement
digeorge syndrome also known as 22 q 11 2 deletion syndrome is a syndrome caused by the deletion of a small segment of chromosome 22 digeorge syndrome is the most common microdeletion syndrome characterized by low copy repeats and the deletion occurs near the middle of the chromosome at a location designated 22 q 11 2 — signifying its location on the long arm of one of the pair of chromosomes 22 on region 1 band 1 sub band 2 the inheritance pattern is autosomal dominant and it has a prevalence estimated at 1 4000 the syndrome was described in 1968 by the pediatric endocrinologist angelo digeorge 22 q 11 deletion is also associated with truncus arteriosus and tetralogy of fallot it is a common but ill understood genetic disorder resulting in medical complications cognitive impairment and brain morphologic changes the complex medical care of patients needs a multidisciplinary approach to improve the function of many organ systems
diabetes mellitus in cats is a chronic disease that affects carbohydrate metabolism due to either an insufficient insulin response or insulin resistance like diabetes in humans it is characterized by chronically high blood glucose diabetes strikes 1 in 400 cats though recent veterinary studies note that it has become increasingly common symptoms in cats are similar to those in humans diabetes in cats occurs less frequently than in dogs 80 95 of diabetic cats experience something similar to type 2 diabetes but are generally severely insulin dependent by the time symptoms are diagnosed the condition is treatable and treated properly the cat can experience a normal life expectancy in type 2 cats prompt effective treatment may lead to in which the cat no longer needs injected insulin untreated the condition leads to increasingly weak legs in cats and eventually malnutrition ketoacidosis and or dehydration and death
diabetes mellitus is a disease in which the beta cells of the endocrine pancreas either stop producing insulin or can no longer produce it in enough quantity for the body s needs the condition is commonly divided into two types depending on the origin of the condition type 1 diabetes sometimes called juvenile diabetes is caused by destruction of the beta cells of the pancreas the condition is also referred to as insulin dependent diabetes meaning exogenous insulin injections must replace the insulin the pancreas is no longer capable of producing for the body s needs dogs can have insulin dependent or type 1 diabetes research finds no type 2 diabetes in dogs because of this there is no possibility the permanently damaged pancreatic beta cells could re activate to engender a remission as may be possible with some feline diabetes cases where the primary type of diabetes is type 2 there is another less common form of diabetes diabetes insipidus which is a condition of insufficient antidiuretic hormone or resistance to it this most common form of diabetes strikes 1 in 500 dogs the condition is treatable and need not shorten the animal s life span or interfere with quality of life if left untreated the condition can lead to cataracts increasing weakness in the legs neuropathy malnutrition ketoacidosis dehydration and death diabetes mainly affects middle age and older dogs but there are juvenile cases the typical canine diabetes patient is middle age female and overweight at diagnosis the number of dogs diagnosed with diabetes mellitus has increased three fold in thirty years in survival rates from almost the same time only 50 survived the first 60 days after diagnosis and went on to be successfully treated at home currently diabetic dogs receiving treatment have the same expected lifespan as non diabetic dogs of the same age and gender
diabetes insipidus di is a condition characterized by excessive thirst and excretion of large amounts of severely dilute urine with reduction of fluid intake having no effect on the concentration of the urine there are different types of di each with a different set of causes the most common type in humans is the neurological form called central di cdi which involves a deficiency of arginine vasopressin avp also known as antidiuretic hormone adh the second common type of di is nephrogenic diabetes insipidus ndi which is due to kidney or nephron dysfunction caused by an insensitivity of the kidneys or nephrons to adh di can also be gestational or caused by alcohol or some types of drug abuse di should not be confused with nocturia although they have a common name diabetes mellitus and diabetes insipidus are two entirely separate conditions with unrelated mechanisms both cause large amounts of urine to be produced polyuria however diabetes insipidus is either a problem with the production of antidiuretic hormone central diabetes insipidus or kidney s response to antidiuretic hormone nephrogenic diabetes insipidus whereas diabetes mellitus causes polyuria via a process called osmotic diuresis due to the high blood sugar leaking into the urine and taking excess water along with it the number of new cases of diabetes insipidus each year is 3 in 100 000 diabetes insipidus usually starts in childhood or early adulthood and affects men more commonly than women the term diabetes is derived from the greek word meaning siphon
diabetes mellitus dm commonly referred to as diabetes is a group of metabolic diseases in which there are high blood sugar levels over a prolonged period symptoms of high blood sugar include frequent urination increased thirst and increased hunger if left untreated diabetes can cause many complications acute complications can include diabetic ketoacidosis nonketotic hyperosmolar coma or death serious long term complications include heart disease stroke chronic kidney failure foot ulcers and damage to the eyes diabetes is due to either the pancreas not producing enough insulin or the cells of the body not responding properly to the insulin produced there are three main types of diabetes mellitus type 1 dm results from the pancreas s failure to produce enough insulin this form was previously referred to as insulin dependent diabetes mellitus iddm or juvenile diabetes the cause is unknown type 2 dm begins with insulin resistance a condition in which cells fail to respond to insulin properly as the disease progresses a lack of insulin may also develop this form was previously referred to as non insulin dependent diabetes mellitus niddm or adult onset diabetes the primary cause is excessive body weight and not enough exercise gestational diabetes is the third main form and occurs when pregnant women without a previous history of diabetes develop high blood sugar levels prevention and treatment involve maintaining a healthy diet regular physical exercise a normal body weight and avoiding use of tobacco control of blood pressure and maintaining proper foot care are important for people with the disease type 1 dm must be managed with insulin injections type 2 dm may be treated with medications with or without insulin insulin and some oral medications can cause low blood sugar weight loss surgery in those with obesity is sometimes an effective measure in those with type 2 dm gestational diabetes usually resolves after the birth of the baby as of 2015 an estimated 415 million people had diabetes worldwide with type 2 dm making up about 90 of the cases this represents 8 3 of the adult population with equal rates in both women and men as of 2014 trends suggested the rate would continue to rise diabetes at least doubles a person s risk of early death from 2012 to 2015 approximately 1 5 to 5 0 million deaths each year resulted from diabetes the global economic cost of diabetes in 2014 was estimated to be us 612 billion in the united states diabetes cost 245 billion in 2012
diabetes mellitus and deafness dad or maternally inherited diabetes and deafness midd is a subtype of diabetes which is caused from a point mutation at position 3243 in human mitochondrial dna which consists of a circular genome this affects the gene encoding trnaleu because mitochondrial dna is contributed to the embryo by the oocyte and not by spermatozoa this disease is inherited from maternal family members only as indicated by the name midd is characterized by diabetes and sensorineural hearing loss
diabetes mellitus type 1 also known as type 1 diabetes is a form of diabetes mellitus in which not enough insulin is produced the lack of insulin results in high blood sugar levels the classical symptoms are frequent urination increased thirst increased hunger and weight loss additional symptoms may include blurry vision feeling tired and poor healing symptoms typically develop over a short period of time the cause of type 1 diabetes is unknown it however is believed to involve a combination of genetic and environmental factors risk factors include having a family member with the condition the underlying mechanism involves an autoimmune destruction of the insulin producing beta cells in the pancreas diabetes is diagnosed by testing the level of sugar or a 1 c in the blood type 1 diabetes may be distinguished from type 2 by autoantibody testing there is no way to prevent type 1 diabetes treatment with insulin is typically required for survival insulin therapy is usually given by injection just under the skin but can also be delivered by an insulin pump a diabetic diet and exercise are an important part of management untreated diabetes can cause many complications complications of relatively rapid onset include diabetic ketoacidosis and nonketotic hyperosmolar coma long term complications include heart disease stroke kidney failure foot ulcers and damage to the eyes furthermore complications may arise from low blood sugar caused by excessive insulin treatment type 1 diabetes makes up an estimated 5 – 10 of all diabetes cases the number of people affected globally is unknown although it is estimated that about 80 000 children develop the disease each year within the united states the number of people affected is estimated at one to three million rates of disease vary widely with approximately 1 new case per 100 000 per year in east asia and latin america and around 30 new cases per 100 000 per year in scandinavia and kuwait it typically begins in children and young adults
diabetes mellitus type 2 also known as type 2 diabetes is a long term metabolic disorder that is characterized by high blood sugar insulin resistance and relative lack of insulin common symptoms include increased thirst frequent urination and unexplained weight loss symptoms may also include increased hunger feeling tired and sores that do not heal often symptoms come on slowly long term complications from high blood sugar include heart disease strokes diabetic retinopathy which can result in blindness kidney failure and poor blood flow in the limbs which may lead to amputations the sudden onset of hyperosmolar hyperglycemic state may occur however ketoacidosis is uncommon type 2 diabetes primarily occurs as a result of obesity and not enough exercise some people are more genetically at risk than others type 2 diabetes makes up about 90 of cases of diabetes with the other 10 due primarily to diabetes mellitus type 1 and gestational diabetes in diabetes mellitus type 1 there is an absolute lack of insulin due to breakdown of islet cells in the pancreas diagnosis of diabetes is by blood tests such as fasting plasma glucose oral glucose tolerance test or a 1 c type 2 diabetes is partly preventable by staying a normal weight exercising regularly and eating properly treatment involves exercise and dietary changes if blood sugar levels are not adequately lowered the medication metformin is typically recommended many people may eventually also require insulin injections in those on insulin routinely checking blood sugar levels is advised however this may not be needed in those taking pills bariatric surgery often improves diabetes in those who are obese rates of type 2 diabetes have increased markedly since 1960 in parallel with obesity as of 2013 there were approximately 368 million people diagnosed with the disease compared to around 30 million in 1985 typically it begins in middle or older age although rates of type 2 diabetes are increasing in young people type 2 diabetes is associated with a ten year shorter life expectancy diabetes was one of the first diseases described the importance of insulin in the disease was determined in the 1920 s
diabetic angiopathy is a form of angiopathy associated with diabetes mellitus while not exclusive the two most common forms are diabetic retinopathy and diabetic nephropathy whose pathophysiologies are largely identical
a diabetic bulla also known as bullosis diabeticorum and bullous eruption of diabetes mellitus is a cutaneous condition characterized by a noninflammatory spontaneous painless blister often in acral locations peripheral body parts such as feet toes hands fingers ears or nose seen in diabetic patients
diabetic cardiomyopathy is a disorder of the heart muscle in people with diabetes it can lead to inability of the heart to circulate blood through the body effectively a state known as heart failure with accumulation of fluid in the lungs pulmonary edema or legs peripheral edema most heart failure in people with diabetes results from coronary artery disease and diabetic cardiomyopathy is only said to exist if there is no coronary artery disease to explain the heart muscle disorder
diabetic cheiroarthropathy is a cutaneous condition characterized by thickened skin and limited joint mobility of the hands and fingers leading to flexion contractures a condition associated with diabetes mellitus and it is observed in roughly 30 of diabetic patients with longstanding disease limited joint mobility or ljm is a complication of type 1 diabetes it was one of the earliest known complications first documented in 1974
diabetic coma is a reversible form of coma found in people with diabetes mellitus it is a medical emergency three different types of diabetic coma are identified 1 severe low blood sugar in a diabetic person 2 diabetic ketoacidosis usually type 1 advanced enough to result in unconsciousness from a combination of a severely increased blood sugar level dehydration and shock and exhaustion 3 hyperosmolar nonketotic coma usually type 2 in which an extremely high blood sugar level and dehydration alone are sufficient to cause unconsciousness in most medical contexts the term diabetic coma refers to the diagnostical dilemma posed when a physician is confronted with an unconscious patient about whom nothing is known except that they have diabetes an example might be a physician working in an emergency department who receives an unconscious patient wearing a medical identification tag saying diabetic paramedics may be called to rescue an unconscious person by friends who identify them as diabetic brief descriptions of the three major conditions are followed by a discussion of the diagnostic process used to distinguish among them as well as a few other conditions which must be considered an estimated 2 to 15 percent of diabetics will suffer from at least one episode of diabetic coma in their lifetimes as a result of severe hypoglycemia
diabetic dermadromes constitute a group of cutaneous conditions commonly seen in people with diabetes with longstanding disease conditions included in this group are acral dry gangrene carotenosis diabetic dermopathy diabetic bulla diabetic cheiroarthropathy malum perforans necrobiosis lipoidica limited joint mobility is observed in roughly 30 of people with diabetes with longstanding disease scleredema waxy skin is observed in roughly 50
diabetic dermopathy also known as shin spots is a type of skin lesion usually seen in people with diabetes mellitus it is characterized by dull red papules that progress to well circumscribed small round atrophic hyperpigmented skin lesions usually on the shins it is the most common of several diabetic skin conditions being found in up to 30 of diabetics similar lesions can occasionally be found in non diabetics usually following trauma or injury to the area however 4 lesions strongly suggests diabetes
a diabetic foot is a foot that exhibits any pathology that results directly from diabetes mellitus or any long term or chronic complication of diabetes mellitus presence of several characteristic diabetic foot pathologies such as infection diabetic foot ulcer and neuropathic osteoarthropathy is called diabetic foot syndrome due to the peripheral nerve dysfunction associated with diabetes diabetic neuropathy patients have a reduced ability to feel pain this means that minor injuries may remain undiscovered for a long while people with diabetes are also at risk of developing a diabetic foot ulcer research estimates that the lifetime incidence of foot ulcers within the diabetic community is around 15 and may become as high as 25 in diabetes peripheral nerve dysfunction can be combined with peripheral artery disease pad causing poor blood circulation to the extremities diabetic angiopathy around half of patients with a diabetic foot ulcer have co existing pad where wounds take a long time to heal infection may set in and lower limb amputation may be necessary foot infection is the most common cause of non traumatic amputation in people with diabetes
diabetic foot ulcer is a major complication of diabetes mellitus and probably the major component of the diabetic foot wound healing is an innate mechanism of action that works reliably most of the time a key feature of wound healing is stepwise repair of lost extracellular matrix ecm that forms the largest component of the dermal skin layer but in some cases certain disorders or physiological insult disturbs the wound healing process diabetes mellitus is one such metabolic disorder that impedes the normal steps of the wound healing process many studies show a prolonged inflammatory phase in diabetic wounds which causes a delay in the formation of mature granulation tissue and a parallel reduction in wound tensile strength treatment of diabetic foot ulcers should include blood sugar control removing dead tissue from the wound dressings and removing pressure from the wound through techniques such as total contact casting surgery in some cases may improve outcomes hyperbaric oxygen therapy may also help but is expensive it occurs in 15 of people with diabetes and precedes 84 of all diabetes related lower leg amputations
diabetic hypoglycemia is a low blood glucose level occurring in a person with diabetes mellitus it is one of the most common types of hypoglycemia seen in emergency departments and hospitals according to the national electronic injury surveillance system all injury program neiss aip and based on a sample examined between 2004 and 2005 an estimated 55 819 cases 8 0 of total admissions involved insulin and severe hypoglycemia is likely the single most common event in general hypoglycemia occurs when a treatment to lower the elevated blood glucose of diabetes inaccurately matches the body s physiological need and therefore causes the glucose to fall to a below normal level
diabetic ketoacidosis dka is a potentially life threatening complication in people with diabetes mellitus it happens predominantly in those with type 1 diabetes but it can occur in those with type 2 diabetes under certain circumstances dka results from a shortage of insulin in response the body switches to burning fatty acids and producing acidic ketone bodies that cause most of the symptoms and complications dka may be the first symptom of previously undiagnosed diabetes but it may also occur in people known to have diabetes as a result of a variety of causes such as intercurrent illness or poor compliance with insulin therapy vomiting dehydration deep gasping breathing confusion and occasionally coma are typical symptoms dka is diagnosed with blood and urine tests it is distinguished from other rarer forms of ketoacidosis by the presence of high blood sugar levels treatment involves intravenous fluids to correct dehydration insulin to suppress the production of ketone bodies treatment for any underlying causes such as infections and close observation to prevent and identify complications dka is a medical emergency and without treatment it can lead to death dka was first described in 1886 until the introduction of insulin therapy in the 1920 s it was almost universally fatal it now carries a mortality of less than 1 with adequate and timely treatment
diabetic myonecrosis is a rare complication of diabetes it is caused by infarcted muscle tissue usually in the thigh
diabetic nephropathy or diabetic kidney disease is a progressive kidney disease caused by damage to the capillaries in the kidneys glomeruli it is characterized by nephrotic syndrome and diffuse scarring of the glomeruli it is due to longstanding diabetes mellitus and is a prime reason for dialysis in many developed countries it is classified as a small blood vessel complication of diabetes
diabetic neuropathies are nerve damaging disorders associated with diabetes mellitus these conditions are thought to result from diabetic microvascular injury involving small blood vessels that supply nerves vasa nervorum in addition to macrovascular conditions that can culminate in diabetic neuropathy relatively common conditions which may be associated with diabetic neuropathy include third nerve palsy mononeuropathy mononeuropathy multiplex diabetic amyotrophy a painful polyneuropathy autonomic neuropathy and thoracoabdominal neuropathy
diabetic retinopathy ˌrɛtnˈɑpəθi also known as diabetic eye disease is when damage occurs to the retina due to diabetes it can eventually lead to blindness it is an ocular manifestation of diabetes a systemic disease which affects up to 80 percent of all patients who have had diabetes for 20 years or more despite these intimidating statistics research indicates that at least 90 of these new cases could be reduced if there were proper and vigilant treatment and monitoring of the eyes the longer a person has diabetes the higher his or her chances of developing diabetic retinopathy each year in the united states diabetic retinopathy accounts for 12 of all new cases of blindness it is also the leading cause of blindness for people aged 20 to 64 years
diadochokinesia or diadochokinesis is the ability to make antagonistic movements in quick succession alternately bringing a limb into opposite positions as of flexion and extension or of pronation and supination speech language pathology defines it as the speed necessary to stop a determined motor impulse and substitute it with its opposite the relative timing of this kind of movements is also called alternate motion rates amr or sequential motor rates smr loss of ability dysdiadochokinesia is characteristic of cerebellar diseases many clinical tests may be employed to test for such disturbances alternating movements patient is told e g to pronate and supinate his hands in rapid succession holding forearms vertically in cerebellar diseases the movements are irregular and inaccurate in case of the pyramidal tract lesion the motion may be slowed or incomplete stewart holmes rebound sign patient tries to flex the elbow against applied resistance when physician s grip is suddenly released the patient should be able to deter it from rebounding with cerebellar disease the forearm may sway in several cycles the patient may even strike himself if not guarded number of instrumental techniques can be used to investigate speech motor skills such as imaging movement transduction and point tracking
a diagnosis of exclusion per exclusionem is a diagnosis of a medical condition reached by a process of elimination which may be necessary if presence cannot be established with complete confidence from history examination or testing such elimination of other reasonable possibilities is a major component in performing a differential diagnosis the largest category of diagnosis by exclusion is seen among psychiatric disorders where the presence of physical or organic disease must be excluded as a prerequisite for making a functional diagnosis diagnosis by exclusion tends to occur where scientific knowledge is scarce specifically where the means to verify a diagnosis by an objective method is absent as a specific diagnosis cannot be confirmed a fall back position is to exclude that group of known causes that may cause a similar clinical presentation
diagnostic substitution is a phenomenon in which one label for a condition becomes replaced with another causing an apparent decrease in the rate of the first condition and increase in the rate of the second
the diamond cubic crystal structure is a repeating pattern of 8 atoms that certain materials may adopt as they solidify while the first known example was diamond other elements in group 14 also adopt this structure including α tin the semiconductors silicon and germanium and silicon germanium alloys in any proportion
diamond – blackfan anemia dba also known as blackfan diamond anemia inherited pure red cell aplasia and as inherited erythroblastopenia is a congenital erythroid aplasia that usually presents in infancy dba causes low red blood cell counts anemia without substantially affecting the other blood components the platelets and the white blood cells which are usually normal this is in contrast to shwachman – bodian – diamond syndrome in which the bone marrow defect results primarily in neutropenia and fanconi anemia where all cell lines are affected resulting in pancytopenia a variety of other congenital abnormalities may also occur in dba
diaphragmatic hernia is a defect or hole in the diaphragm that allows the abdominal contents to move into the chest cavity treatment is usually surgical the following types of diaphragmatic hernia exist congenital diaphragmatic hernia morgagni s hernia bochdalek hernia hiatal hernia iatrogenic diaphragmatic hernia traumatic diaphragmatic hernia
diaphragmatic rupture also called diaphragmatic injury or tear is a tear of the diaphragm the muscle across the bottom of the ribcage that plays a crucial role in respiration most commonly acquired diaphragmatic tears result from physical trauma diaphragmatic rupture can result from blunt or penetrating trauma and occurs in about 5 of cases of severe blunt trauma to the trunk diagnostic techniques include x ray computed tomography and surgical techniques such as laparotomy diagnosis is often difficult because signs may not show up on x ray or signs that do show up appear similar to other conditions signs and symptoms included chest and abdominal pain difficulty breathing and decreased lung sounds when a tear is discovered surgery is needed to repair it injuries to the diaphragm are usually accompanied by other injuries and they indicate that more severe injury may have occurred the outcome often depends more on associated injuries than on the diaphragmatic injury itself since the pressure is higher in the abdominal cavity than the chest cavity rupture of the diaphragm is almost always associated with herniation of abdominal organs into the chest cavity which is called a traumatic diaphragmatic hernia this herniation can interfere with breathing and blood supply can be cut off to organs that herniate through the diaphragm damaging them
diarrhea also spelled diarrhoea is the condition of having at least three loose or liquid bowel movements each day it often lasts for a few days and can result in dehydration due to fluid loss signs of dehydration often begin with loss of the normal stretchiness of the skin and irritable behaviour this can progress to decreased urination loss of skin color a fast heart rate and a decrease in responsiveness as it becomes more severe loose but non watery stools in babies who are breastfed however may be normal the most common cause is an infection of the intestines due to either a virus bacteria or parasite a condition known as gastroenteritis these infections are often acquired from food or water that has been contaminated by stool or directly from another person who is infected it may be divided into three types short duration watery diarrhea short duration bloody diarrhea and if it lasts for more than two weeks persistent diarrhea the short duration watery diarrhea may be due to an infection by cholera although this is rare in the developed world if blood is present it is also known as dysentery a number of non infectious causes may also result in diarrhea including hyperthyroidism lactose intolerance inflammatory bowel disease a number of medications and irritable bowel syndrome in most cases stool cultures are not required to confirm the exact cause prevention of infectious diarrhea is by improved sanitation clean drinking water and hand washing with soap breastfeeding for at least six months is also recommended as is vaccination against rotavirus oral rehydration solution ors which is clean water with modest amounts of salts and sugar is the treatment of choice zinc tablets are also recommended these treatments have been estimated to have saved 50 million children in the past 25 years when people have diarrhea it is recommended that they continue to eat healthy food and babies continue to be breastfed if commercial ors are not available homemade solutions may be used in those with severe dehydration intravenous fluids may be required most cases however can be managed well with fluids by mouth antibiotics while rarely used may be recommended in a few cases such as those who have bloody diarrhea and a high fever those with severe diarrhea following travelling and those who grow specific bacteria or parasites in their stool loperamide may help decrease the number of bowel movements but is not recommended in those with severe disease about 1 7 to 5 billion cases of diarrhea occur per year it is most common in developing countries where young children get diarrhea on average three times a year total deaths from diarrhea are estimated at 1 26 million in 2013 – down from 2 58 million in 1990 in 2012 it was the second most common cause of deaths in children younger than five 0 76 million or 11 frequent episodes of diarrhea are also a common cause of malnutrition and the most common cause in those younger than five years of age other long term problems that can result include stunted growth and poor intellectual development
diaschisis from greek διάσχισις meaning shocked throughout is a sudden loss or change of function in a portion of the brain connected to a distant but damaged brain area the site of the originally damaged area and of the diaschisis are connected to each other by neurons the loss of the damaged structure disrupts the function of the remaining intact systems and causes a physiological imbalance the injury is produced by an acute focal disturbance in an area of the brain from traumatic brain injury or stroke for example some function may be restored with gradual readjustment of the intact but suppressed areas through intervention and the brain s natural neuroplasticity the term diaschisis was coined by constantin von monakow in 1914 currently the term diaschisis is used to describe a depression of regional neuronal metabolism and cerebral blood flow caused by dysfunction in an anatomically separate but functionally related neuronal region von monakow s concept of neurophysical changes in distant brain tissue to the focal lesion led to a widespread clinical interest doctors were interested in how diaschisis could describe the signs and symptoms of brain lesions that could not be explained the areas of the brain are connected by vast organized neuronal pathways that allow one area of the brain to influence other areas more distal to it understanding these dense pathways helps to link a lesion causing brain damage in one area of the brain to degeneration in a more distal brain area a focal lesion causes damage that also disturbs the structural and functional connectivity to the brain areas distal to the lesion the primary mechanism of diaschisis is functional deafferentation which is the loss of the input of information from the part of the brain that is now damaged the decrease in information and neural firing to the distal brain area causes those synaptic connections to weaken and initiates a change in the structural and functional connectivity around that area this leads to diaschisis diaschisis is also influenced by many other factors including stoke brain swelling and neuroanatomical disconnection the severity of these factors is manifested in altered neuronal excitability hypo metabolism and hypo perfusion there are two types of diaschisis the first is focal diaschisis which refers to the remote neurophysiological changes that are caused by a focal lesion based on von monakow s definition the second type of diaschisis is non focal diaschisis and it focuses on the changes in the strength and direction of neural pathways and connectivity between brain areas this type of diaschisis has only been a topic in recent study as a result of the advancement of brain imaging tools and technology these new tools allow for better understanding of the organization of the brain connectivity and further investigation into new types of diaschisis like non focal or connectional diascisis this new type of diaschisis relates much more closely to clinical findings
in pathology diastasis is the separation of parts of the body that are normally joined together such as the separation of certain abdominal muscles during pregnancy or of adjacent bones without fracture
diastasis recti also known as abdominal separation is commonly defined as a gap of roughly 2 7 cm or greater between the two sides of the rectus abdominis muscle this condition has no associated morbidity or mortality the distance between the right and left rectus abdominis muscles is created by the stretching of the linea alba a connective collagen sheath created by the aponeurosis insertions of the transverse abdominis internal oblique and external oblique diastasis of this muscle occurs principally in two populations newborns and pregnant women it is also known to occur in men in the newborn the rectus abdominis is not fully developed and may not be sealed together at midline diastasis recti is more common in premature and black newborns in pregnant or postpartum women the condition is caused by the stretching of the rectus abdominis by the growing uterus it is more common in multiparous women due to repeated episodes of stretching when the defect occurs during pregnancy the uterus can sometimes be seen bulging through the abdominal wall beneath the skin women are more susceptible to develop diastasis recti when over the age of 35 high birth weight of child multiple birth pregnancy and multiple pregnancies additional causes can be attributed to excessive abdominal exercises after the first trimester of pregnancy
diastasis symphysis pubis is the separation of normally joined pubic bones as in the dislocation of the bones without a fracture
diastematomyelia occasionally diastomyelia is a congenital disorder in which a part of the spinal cord is split usually at the level of the upper lumbar vertebra diastematomyelia is a rare congenital anomaly that results in the splitting of the spinal cord in a longitudinal sagittal direction females are affected much more commonly than males this condition occurs in the presence of an osseous bone cartilaginous or fibrous septum in the central portion of the spinal canal which then produces a complete or incomplete sagittal division of the spinal cord into two hemicords when the split does not reunite distally to the spur the condition is referred to as a diplomyelia or true duplication of the spinal cord
diastolic heart failure and diastolic dysfunction refer to the decline in performance of one usually the left ventricle or both left and right ventricles during diastole diastole is the cardiac cycle phase during which the heart is relaxing and filling with incoming blood that is being returned from the body through the inferior ivc and superior svc venae cavae to the right atrium and from lungs through pulmonary veins to the left atrium in diastolic failure if the patient has symptoms there is a pathologic cause inducing them diastolic dysfunction can be found when doing a doppler echocardiography in an apparently healthy patient mainly in an elderly person
diastrophic dysplasia dtd is an autosomal recessive dysplasia which affects cartilage and bone development diastrophism is a general word referring to a twisting diastrophic dysplasia is due to mutations in the slc 26 a 2 gene affected individuals have short stature with very short arms and legs and joint problems that restrict mobility
in medicine and allied fields diathesis from greek διάθεσις is a hereditary or constitutional predisposition to a disease or other disorder atopic diathesis is a predisposition to develop one or more of hay fever allergic rhinitis bronchial asthma or atopic dermatitis
dicarboxylic aminoaciduria is a rare form of aminoaciduria 1 35 000 births which is an autosomal recessive disorder of urinary glutamate and aspartate due to genetic errors related to transport of these amino acids mutations resulting in a lack of expression of the slc 1 a 1 gene a member of the solute carrier family are found to cause development of dicarboxylic aminoaciduria in humans slc 1 a 1 encodes for eaat 3 which is found in the neurons intestine kidney lung and heart eaat 3 is part of a family of high affinity glutamate transporters which transport both glutamate and aspartate across the plasma membrane
dichromacy di meaning two and chroma meaning color is the state of having two types of functioning color receptors called cone cells in the eyes organisms with dichromacy are called dichromats dichromats can match any color they see with a mixture of no more than two pure spectral lights by comparison trichromats require three pure spectral lights to match all colors that they can perceive and tetrachromats require four dichromacy in humans is a color vision defect in which one of the three basic color mechanisms is absent or not functioning it is hereditary and sex linked predominantly affecting males dichromacy occurs when one of the cone pigments is missing and color is reduced to two dimensions
dichromatism or polychromatism is a phenomenon where a material or solution s hue is dependent on both the concentration of the absorbing substance and the depth or thickness of the medium traversed in most substances which are not dichromatic only the brightness and saturation of the colour depend on their concentration and layer thickness examples of dichromatic substances are pumpkin seed oil bromophenol blue and resazurin when the layer of pumpkin seed oil is less than 0 7 mm thick the oil appears bright green and in layer thicker than this it appears bright red the phenomenon is related to both the physical chemistry properties of the substance and the physiological response of the human visual system to colour this combined physicochemical – physiological basis was first explained in 2007
in analytic number theory the dickman function or dickman – de bruijn function ρ is a special function used to estimate the proportion of smooth numbers up to a given bound it was first studied by actuary karl dickman who defined it in his only mathematical publication and later studied by the dutch mathematician nicolaas govert de bruijn
didactic organisation is the ability of neurons within a network to impart their pattern of synaptic connectivity and or response properties to other neurons the term didactic is used because this kind of influence is unidirectional each individual instance of didactic organisation between two connected neurons does not involve a bidirectional transfer of connectivity or response property information between them
the diderot effect is a social phenomenon related to consumer goods that comprises two ideas the first posits that goods purchased by consumers will be cohesive to their sense of identity and as a result will be complementary to one another the second states that the introduction of a new possession that is deviant from the consumer s current complementary goods can result in a process of spiraling consumption the term was coined by anthropologist and scholar of consumption patterns grant mccracken in 1988 and is named after the french philosopher denis diderot 1713 – 1784 who first described the effect in an essay the term has become common in discussions of sustainable consumption and green consumerism in regard to the process whereby a purchase or gift creates dissatisfaction with existing possessions and environment provoking a potentially spiraling pattern of consumption with negative environmental psychological and social impacts
die swell also known as extrudate swell or barus effect is a common phenomenon in polymer processing die swell occurs in instances of polymer extrusion in which a stream of polymeric material is forced through a die a specialized tool in manufacturing to shape or cut polymeric materials die swell is an instance where a polymer stream is compressed by entrance into a die and is followed by a partial recovery or “ swell ” back to the former shape and volume of the polymer after exiting the die hence the term die swell die swell is a phenomenon directly related to entropy and the relaxation of the polymer within the flow stream initially a flow stream has a constant rate before entering the die and the polymers within the stream occupy a roughly spherical conformation maximizing entropy extrusion through the die causes an increase in flow rate through the polymer flow stream as the polymer spends time inside the die and is subject to the much increased flow rate the polymers lose the spherical shape becoming longer due to the increased flow rate physical entanglements may relax if the time scale of the polymer within the die is long enough when the polymer stream leaves the die the remaining physical entanglements cause the polymers in the die stream to regain a portion of its former shape and spherical volume in order to return to the roughly spherical conformation that maximizes entropy the disentanglement of polymer chains is a kinetic process and so the longer the die is the more time is given for the physical entanglements within the polymer stream to disentangle with a longer die and a slower polymer flow stream less pronounced die swell will be observed this is due to the longer die providing a longer time period for polymer when subject to the increase flow rate to disentangle this characteristic relaxation time determines the length of time the polymer must spend inside the die to minimize die swell die swell illustration
the dieckmann condensation is the intramolecular chemical reaction of diesters with base to give β ketoesters it is named after the german chemist walter dieckmann 1869 – 1925 the equivalent intermolecular reaction is the claisen condensation the dieckmann condensation
diel vertical migration also known as diurnal vertical migration is a pattern of movement used by some organisms such as copepods living in the ocean and in lakes the migration occurs when organisms move up to the epipelagic zone at night and return to the mesopelagic zone of the oceans or to the hypolimnion zone of lakes during the day the word diel comes from the latin dies day and means a 24 hour period it is referred to as the greatest migration in the world in terms of biomass
dielectrophoresis or dep is a phenomenon in which a force is exerted on a dielectric particle when it is subjected to a non uniform electric field this force does not require the particle to be charged all particles exhibit dielectrophoretic activity in the presence of electric fields however the strength of the force depends strongly on the medium and particles electrical properties on the particles shape and size as well as on the frequency of the electric field consequently fields of a particular frequency can manipulate particles with great selectivity this has allowed for example the separation of cells or the orientation and manipulation of nanoparticles and nanowires furthermore a study of the change in dep force as a function of frequency can allow the electrical or electrophysiological in the case of cells properties of the particle to be elucidated
the diels – alder reaction is an organic chemical reaction specifically a 4 2 cycloaddition between a conjugated diene and a substituted alkene commonly termed the dienophile to form a substituted cyclohexene system it was first described by otto diels and kurt alder in 1928 for which work they were awarded the nobel prize in chemistry in 1950 the diels – alder reaction is particularly useful in synthetic organic chemistry as a reliable method for forming 6 membered systems with good control over regio and stereochemical properties the underlying concept has also been applied to other π systems such as carbonyls and imines to furnish the corresponding heterocycles known as the hetero diels – alder reaction diels – alder reactions can be reversible under certain conditions the reverse reaction is known as the retro diels – alder reaction the reaction discovered by diels and alder in 1928
diencephalic syndrome diencephalic syndrome of emaciation or russell s syndrome is a rare neurological disorder seen in infants and children and characterised by failure to thrive and severe emaciation despite normal or slightly decreased caloric intake locomotor hyperactivity and euphoria less commonly it may involve skin pallor without anaemia hypoglycaemia and hypotension the syndrome is a rare but potentially fatal cause of failure to thrive in children failure to thrive presents on average at 7 months of age of note the syndrome is not associated with developmental delay there may be associated hydrocephalus diencephalic syndrome was first described by russell in 1951 it is usually caused by a brain tumor such as a low grade glioma or astrocytoma located in the hypothalamic optic chiasmatic region it is not yet understood how diencephalic syndrome causes the effects on appetite and metabolism which are seen though inappropriately high growth hormone release has been proposed as has excessive β lipotropin secretion and overall increased metabolic demand it is treated with nutritional optimisation while the underlying lesion is treated with chemotherapy surgery or radiotherapy
dientamoebiasis is a medical condition caused by infection with dientamoeba fragilis a single cell parasite that infects the lower gastrointestinal tract of humans it is an important cause of traveler s diarrhea chronic abdominal pain chronic fatigue and failure to thrive in children
diesel engine runaway is a rare condition affecting diesel engines in which the engine draws extra fuel from an unintended source and overspeeds at higher and higher rpm until destroyed by mechanical failure or bearing seizure through lack of lubrication
dieseling or engine run on is a condition that can occur in spark plug ignited gasoline powered internal combustion engines whereby the engine keeps running for a short period after being turned off due to the engine kicking back upon shutdown drawing fuel through the carburetor into the engine and igniting it without a spark dieseling is so named because it is similar in effect to how diesel engines operate by firing without a spark the ignition source of a diesel engine is the heat generated by the compression of the air in the cylinder rather than a spark as in gasoline engines the dieseling phenomenon occurs not just because the compression ratio is sufficient to cause auto ignition of the fuel but also because a hot spot inside the cylinder spark plug electrode combustion chamber valve edge or even excess carbon starts combustion an automobile engine that is dieseling will typically sputter then gradually stop this is normally seen in carbureted engines with many miles on them dieseling is not nearly as common as it once was because it most commonly occurs in engines equipped with carburetors the vast majority of vehicles manufactured after 1987 are fuel injected the injectors and high pressure fuel pump immediately cease supplying fuel to the cylinders when the ignition is switched off if the injector is damaged or dirty a small amount of fuel can enter the chamber and be ignited causing a sputter or two after the engine is switched off until the mass market introduction of fuel injection the industry s remedy for dieseling was to install an electric solenoid into the fuel supply circuit of the carburetor energized by the ignition coil primary wire when activated the solenoid would open and allow fuel to flow normally out of the float bowl through the fuel metering jets and into the engine when deactivated the solenoid would close and prevent fuel from being drawn through the jets and into the engine this provided a simple adequate solution to the dieseling problem dieseling in the sense of engine run on and disregarding combustible gaseous mixtures via the air intake can also occur in diesel engines when the piston or seals fail due to overheating admitting engine oil into the cylinder a structurally failing diesel engine will often accelerate when the throttle is released even after fuel injection is switched off some carbureted engines have low pressure fuel pumps they are typically designed only to overcome a loss of suction in the fuel line near the engine due to fuel evaporation in hot weather to supply sufficient fuel to maintain stoichiometric combustion under heavy load with wide open throttle or a combination of the two fuel demand is low at idle and there is more than enough manifold vacuum to draw sufficient fuel for combustion even if the fuel pump is switched off gasoline engines that are much smaller than the typical automotive engine are usually carbureted for economic and engineering reasons dieseling can occur in such engines these engines include those installed in small generators mopeds scooters small motorcycles all terrain vehicles and most lawn and garden power tools
a diet coke and mentos eruption alternately diet coke and mentos geyser or mentos eruption is a reaction between the carbonated beverage diet coke and mentos mints that causes the beverage to spray out of its container the gas released by the candies creates an eruption that pushes most of the liquid up and out of the bottle lee marek and marek s kid scientists were the first to demonstrate the experiment on television in 1999 steve spangler s televised demonstration of the eruption in 2005 went viral on youtube launching a chain of several other diet coke and mentos experiment viral videos
dieulafoy s lesion exulceratio simplex dieulafoy is a medical condition characterized by a large tortuous arteriole most commonly in the stomach wall submucosal that erodes and bleeds it can present in any part of the gastrointestinal tract it can cause gastric hemorrhage but is relatively uncommon it is thought to cause less than 5 of all gastrointestinal bleeds in adults it was named after french surgeon paul georges dieulafoy who described this condition in his paper exulceratio simplex leçons 1 3 in 1898 it is also called caliber persistent artery or aneurysm of gastric vessels however unlike most other aneurysms these are thought to be developmental malformations rather than degenerative changes
in calculus a branch of mathematics a differentiable function of one real variable is a function whose derivative exists at each point in its domain as a result the graph of a differentiable function must have a non vertical tangent line at each point in its domain be relatively smooth and cannot contain any breaks bends or cusps more generally if x 0 is a point in the domain of a function f then f is said to be differentiable at x 0 if the derivative f ′ x 0 exists this means that the graph of f has a non vertical tangent line at the point x 0 f x 0 the function f may also be called locally linear at x 0 as it can be well approximated by a linear function near this point
in mathematics differential rings differential fields and differential algebras are rings fields and algebras equipped with finitely many derivations which are unary functions that are linear and satisfy the leibniz product rule a natural example of a differential field is the field of rational functions c t in one variable over the complex numbers where the derivation is the differentiation with respect to t differential algebra refers also to the area of mathematics consisting in the study of these algebraic objects and their use for an algebraic study of the differential equations differential algebra was introduced by joseph ritt
in mathematics differential calculus is a subfield of calculus concerned with the study of the rates at which quantities change it is one of the two traditional divisions of calculus the other being integral calculus the primary objects of study in differential calculus are the derivative of a function related notions such as the differential and their applications the derivative of a function at a chosen input value describes the rate of change of the function near that input value the process of finding a derivative is called differentiation geometrically the derivative at a point is the slope of the tangent line to the graph of the function at that point provided that the derivative exists and is defined at that point for a real valued function of a single real variable the derivative of a function at a point generally determines the best linear approximation to the function at that point differential calculus and integral calculus are connected by the fundamental theorem of calculus which states that differentiation is the reverse process to integration differentiation has applications to nearly all quantitative disciplines for example in physics the derivative of the displacement of a moving body with respect to time is the velocity of the body and the derivative of velocity with respect to time is acceleration the derivative of the momentum of a body equals the force applied to the body rearranging this derivative statement leads to the famous f ma equation associated with newton s second law of motion the reaction rate of a chemical reaction is a derivative in operations research derivatives determine the most efficient ways to transport materials and design factories derivatives are frequently used to find the maxima and minima of a function equations involving derivatives are called differential equations and are fundamental in describing natural phenomena derivatives and their generalizations appear in many fields of mathematics such as complex analysis functional analysis differential geometry measure theory and abstract algebra
in mathematics the differential coefficient of a function f x is what is now called its derivative df x dx the not necessarily constant multiplicative factor or coefficient of the differential dx in the differential df x a coefficient is usually a constant quantity but the differential coefficient of f is a constant function only if f is a linear function when f is not linear its differential coefficient is a function call it f ′ derived by the differentiation of f hence the modern term derivative the older usage is now rarely seen early editions of silvanus p thompson s calculus made easy use the older term in his 1998 update of this text martin gardner lets the first use of differential coefficient stand along with thompson s criticism of the term as a needlessly obscure phrase that should not intimidate students and substitutes derivative for the remainder of the book
differential object marking dom is a linguistic phenomenon that is present in more than 300 languages the term was coined by georg bossong in languages where dom is active direct objects are divided in two different classes depending on different meanings and in most dom languages only one of the classes receives a marker the other being unmarked but there are languages like finnish where both types of objects are marked with different endings
differential sticking is a problem that occurs when drilling a well with a greater well bore pressure than formation pressure as is usually the case the drill pipe is pressed against the wellbore wall so that part of its circumference will see only reservoir pressure while the rest will continue to be pushed by wellbore pressure as a result the pipe becomes stuck to the wall and can require millions of pounds of force to remove which may prove impossible in many cases the drilling fluid mud weight is reduced thus relieving the pressure difference and releasing the stuck pipe string should this option be unavailable as in sour gas wells a specialty fishing company is called to retrieve the stuck pipe or fish many options exist once a fishing company is on site oil or nitrogen may be pumped down the well or the fish may be washed over using a carbide shoe on a string of washpipe jarring is not usually attempted with differential sticking due to the massive amount of pressure that holds the pipe in place
differentiated service is a design pattern for business services and software in which the service varies automatically according to the identity of the consumer and or the context in which the service is used sometimes known as smart service or context aware service
the diffie – hellman problem dhp is a mathematical problem first proposed by whitfield diffie and martin hellman in the context of cryptography the motivation for this problem is that many security systems use mathematical operations that are fast to compute but hard to reverse for example they enable encrypting a message but reversing the encryption is difficult if solving the dhp were easy these systems would be easily broken
diffraction in time is a phenomenon associated with the quantum dynamics of suddenly released matter waves initially confined in a region of space it was introduced in 1952 by marcos moshinsky with the shutter problem a matter wave beam stopped by an absorbing shutter exhibits an oscillatory density profile during its propagation after removal of the shutter whenever this propagation is accurately described by the time dependent schrödinger equation the transient wave functions resemble the solutions that appear for the intensity of light subject to fresnel diffraction by a straight edge for this reason the transient phenomenon was dubbed diffraction in time and has since then been recognised as ubiquitous in quantum dynamics the experimental confirmation of this phenomenon was only achieved about half a century later in the group of ultracold atoms directed by jean dalibard
diffuse idiopathic pulmonary neuroendocrine cell hyperplasia dipnech is diffuse parenchymal lung disease which often presents with symptoms of cough and shortness of breath the pathological definition published by the world health organization is “ a generalized proliferation of scattered single cells small nodules neuroendocrine bodies or linear proliferations of pulmonary neuroendocrine pne cells that may be confined to the bronchial and bronchiolar epithelium ” the true prevalence of this disease is not known to date just under 200 cases have been reported in the literature however with an increase in recognition of this disease by radiologists and pulmonologists the number of cases has been increasing dipnech predominantly affects middle aged women with slowly progressive lung obstruction dipnech is usually discovered in one of two ways 1 as an unexpected finding following a lung surgery or 2 by evaluation of a patient in a pulmonary clinic with longstanding unexplained symptoms
diffuse alveolar damage is a histological pattern in lung disease it is seen in acute respiratory distress syndrome ards transfusion related acute lung injury trali and acute interstitial pneumonia aip
diffuse axonal injury dai is a brain injury in which damage in the form of extensive lesions in white matter tracts occurs over a widespread area dai is one of the most common and devastating types of traumatic brain injury and is a major cause of unconsciousness and persistent vegetative state after severe head trauma it occurs in about half of all cases of severe head trauma and may be the primary damage that occurs in concussion the outcome is frequently coma with over 90 of patients with severe dai never regaining consciousness those who do wake up often remain significantly impaired dai can occur in every degree of severity from very mild or moderate to very severe concussion may be a milder type of diffuse axonal injury
diffuse esophageal spasm des is a condition characterized by uncoordinated contractions of the esophagus which may cause difficulty swallowing dysphagia or regurgitation in some cases it may causes symptoms such as chest pain similar to heart disease the cause of des remains unknown certain abnormalities on x ray imaging are commonly observed in des such as a corkscrew or rosary bead esophagus although these findings are not unique to this condition specialized testing called manometry can be performed to evaluate the motor function of the esophagus which can help identify abnormal patterns of muscle contraction within the esophagus that are suggestive of des the treatment of des consists primarily of medications such as acid suppressing agents like proton pump inhibitors calcium channel blockers or nitrates in only extremely rare cases surgery may be considered people with des have higher incidences of gastroesophageal reflux disease gerd and anxiety
diffuse idiopathic skeletal hyperostosis dish is a non inflammatory spondyloarthropathy of the spine it is characterized by spiny ankylosis and enthesopathy ossification of the ligaments and entheses it most commonly affects the thoracic and thoraco lumbar spine but involvement is variable and can include the entire spine the disc spaces facet and sacroiliac joints remain unaffected diagnosis requires confluent ossification of at least four contiguous vertebral bodies classically advanced disease may have melted candle wax appearance along the spine on radiographic studies the calcification and ossification is most common on the right side of the spine in people with dextrocardia and situs inversus this calcification occurs on the left side which confirms the role of the descending thoracic aorta in preventing the physical manifestations of dish on one side of the spine
diffuse infantile fibromatosis is a condition affecting infants during the first 3 years of life it is usually confined to the muscles of the arms neck and shoulder area there is a multicentric infiltration of muscle fibers with fibroblasts resembling those seen in aponeurotic fibromas
diffuse infiltrative lymphocytosis syndrome occurs in hiv positive patients with low cd 4 counts it is similar to sjögren s syndrome with painless parotid and submandibular swelling and sicca symptoms the syndrome typically improves with haart
a diffuse intrinsic pontine glioma dipg is a tumour located in the pons middle of the brain stem the brain stem is the bottommost portion of the brain connecting the cerebrum with the spinal cord the majority of brain stem tumours occur in the pons and are diffusely infiltrating they grow amidst the nerves and therefore cannot be surgically removed glioma is a general name for any tumour that arises from the supportive tissue called glia which help keep the neurons in place and functioning well the brain stem contains all of the afferent incoming neurons within the spinal cord as well as important structures involved in eye movements and in face and throat muscle control and sensation
diffuse lamellar keratitis dlk is a sterile inflammation of the cornea which may occur after refractive surgery such as lasik its incidence has been estimated to be 1 in 500 patients though this may be as high as 32 in some cases
diffuse large b cell lymphoma dlbcl or dlbl is a cancer of b cells a type of white blood cell responsible for producing antibodies it is the most common type of non hodgkin lymphoma among adults with an annual incidence of 7 – 8 cases per 100 000 people per year this cancer occurs primarily in older individuals with a median age of diagnosis at approximately 70 years of age though it can also occur in children and young adults in rare cases dlbcl is an aggressive tumor which can arise in virtually any part of the body and the first sign of this illness is typically the observation of a rapidly growing mass sometimes associated with fever weight loss and night sweats the causes of diffuse large b cell lymphoma are not well understood usually dlbcl arises from normal b cells but it can also represent a malignant transformation of other types of lymphoma or leukemia an underlying immunodeficiency is a significant risk factor infection with epstein – barr virus has also been found to contribute to the development of some subgroups of dlbcl diagnosis of dlbcl is made by removing a portion of the tumor through a biopsy and then examining this tissue using a microscope usually a hematopathologist makes this diagnosis several subtypes of dlbcl have been identified each having a different clinical presentation and prognosis however the usual treatment for each of these is chemotherapy often in combination with an antibody targeted at the tumor cells through these treatments more than half of patients with dlbcl can be cured and the overall five year survival rate for older adults is around 58
diffuse myelinoclastic sclerosis sometimes referred to as schilder s disease is a very infrequent neurodegenerative disease that presents clinically as pseudotumoural demyelinating lesions that make its diagnosis difficult it usually begins in childhood affecting children between 5 and 14 years old but cases in adults are possible this disease is considered one of the borderline forms of multiple sclerosis because some authors consider them different diseases and others ms variants other diseases in this group are neuromyelitis optica nmo balo concentric sclerosis and marburg multiple sclerosis
diffuse panbronchiolitis dpb is an inflammatory lung disease of unknown cause it is a severe progressive form of bronchiolitis an inflammatory condition of the bronchioles small air passages in the lungs the term diffuse signifies that lesions appear throughout both lungs while panbronchiolitis refers to inflammation found in all layers of the respiratory bronchioles those involved in gas exchange dpb causes severe inflammation and nodule like lesions of terminal bronchioles chronic sinusitis and intense coughing with large amounts of sputum production the disease is believed to occur when there is susceptibility or a lack of immune system resistance to dpb causing bacteria or viruses caused by several genes that are found predominantly in individuals of east asian descent the highest incidence occurs among japanese people followed by koreans dpb occurs more often in males and usually begins around age 40 it was recognized as a distinct new disease in the early 1960 s and was formally named diffuse panbronchiolitis in 1969 if left untreated dpb progresses to bronchiectasis an irreversible lung condition that involves enlargement of the bronchioles and pooling of mucus in the bronchiolar passages daily treatment of dpb with macrolide antibiotics such as erythromycin eases symptoms and increases survival time but the disease currently has no known cure the eventual result of dpb can be respiratory failure and heart problems
diffuse proliferative nephritis dpn or glomerulonephritis dpgn is a type of glomerulonephritis that is the most serious form of renal lesions in sle and is also the most common occurring in 35 to 60 of patients most of the glomeruli show endothelial and mesangial proliferation affecting the entire glomerulus leading to diffuse hypercellularity of the glomeruli producing in some cases epithelial crescents that fill bowman s space when extensive immune complexes create an overall thickening of the capillary wall resembling rigid wire loops on routine light microscopy electron microscopy reveals electron dense subendothelial immune complexes between endothelium and basement membrane immune complexes can be visualized by staining with fluorescent antibodies directed against immunoglobulins or complement resulting in a granular fluorescent staining pattern in due course glomerular injury gives rise to scarring glomerulosclerosis most of these patients have hematuria with moderate to severe proteinuria hypertension and renal insufficiency
diffuse unilateral subacute neuroretinitis dusn is a rare condition that occurs in otherwise healthy often young patients and is due to the presence of a subretinal nematode
diffusion controlled or diffusion limited reactions are reactions that occur so quickly that the reaction rate is the rate of transport of the reactants through the reaction medium usually a solution as quickly as the reactants encounter each other they react the process of chemical reaction can be considered as involving the diffusion of reactants until they encounter each other in the right stoichiometry and form an activated complex which can form the product species the observed rate of chemical reactions is generally speaking the rate of the slowest or rate determining step in diffusion controlled reactions the formation of products from the activated complex is much faster than the diffusion of reactants and thus the rate is governed by collision frequency diffusion control is rare in the gas phase where rates of diffusion of molecules are generally very high diffusion control is more likely in solution where diffusion of reactants is slower due to the greater number of collisions with solvent molecules reactions where the activated complex forms easily and the products form rapidly are most likely to be limited by diffusion control examples are those involving catalysis and enzymatic reactions heterogeneous reactions where reactants are in different phases are also candidates for diffusion control one classical test for diffusion control is to observe whether the rate of reaction is affected by stirring or agitation if so then the reaction is almost certainly diffusion controlled under those conditions
diffusion of responsibility is a sociopsychological phenomenon whereby a person is less likely to take responsibility for action or inaction when others are present considered a form of attribution the individual assumes that others either are responsible for taking action or have already done so the phenomenon tends to occur in groups of people above a certain critical size and when responsibility is not explicitly assigned it rarely occurs when the person is alone and diffusion increases with groups of three or more
digestion chambers are a histologic finding in nerves that are undergoing wallerian degeneration
digestive system neoplasms are tumors which affect the digestive system types include esophageal cancer gastric cancer small intestinal cancer colorectal cancer anal cancer
in electronics a digital to analog converter dac d a d – a d 2 a or d to a is a device that converts a digital signal into an analog signal an analog to digital converter adc performs the reverse function there are several dac architectures the suitability of a dac for a particular application is determined by six main parameters physical size power consumption resolution maximum sampling frequency accuracy and cost due to the complexity and the need for precisely matched components all but the most specialized dacs are implemented as integrated circuits ics digital to analog conversion can degrade a signal so a dac should be specified that has insignificant errors in terms of the application dacs are commonly used in music players to convert digital data streams into analog audio signals they are also used in televisions and mobile phones to convert digital video data into analog video signals which connect to the screen drivers to display monochrome or color images these two applications use dacs at opposite ends of the speed resolution trade off the audio dac is a low speed high resolution type while the video dac is a high speed low to medium resolution type discrete dacs would typically be extremely high speed low resolution power hungry types as used in military radar systems very high speed test equipment especially sampling oscilloscopes may also use discrete dacs
digital camouflage is a type of camouflage pattern combining micro and macro patterns often though not necessarily with a pixellated look created with computer assistance the function is to provide military camouflage over a range of distances or equivalently over a range of scales in the manner of fractals not all multiscale patterns are pixellated and not all pixellated patterns work at different scales so being pixelated does not of itself guarantee improved performance the root of the modern digital camouflage patterns can be traced back to 1930 s experiments in europe for the german and soviet armies modern digital patterns date to the 1970 s with work by u s army officer timothy o neill for armor camouflage later followed by canadian development of cadpat and then with us work led by o neill which created marpat
digital continuity is the ability to maintain the digital information of a creator in such a way that the information will continue to be available as needed despite changes in digital technology it focuses on making sure that information is complete available and therefore usable activities involved with managing digital continuity include information management information risk assessment and managing technical environments including file format conversion digital continuity management is particularly important to organisations that have a duty to maintain accountability and to act transparently and legally such as government and infrastructure companies digital continuity is also an important issue for organisations responsible for maintaining repositories of information in digital form over time such as archives and libraries
digitally controlled impedance is a function for controlling impedance in fpgas series resistance to match line impedance parallel resistance to avoid reflection
digoxin poisoning also known as digoxin toxicity is a type of poisoning that may occur in people who take too much of the drug digoxin in a short period of time or in those who accumulate high levels of digoxin in their blood during long term treatment digoxin derived from foxglove plants of the genus digitalis is a medication prescribed to people with heart failure and or atrial fibrillation
dihydropyrimidine dehydrogenase deficiency dpd deficiency is an autosomal recessivemetabolic disorder in which there is absent or significantly decreased activity of dihydropyrimidine dehydrogenase an enzyme involved in the metabolism of uracil and thymine individuals with this condition may develop life threatening toxicity following exposure to 5 fluorouracil 5 fu a chemotherapy drug that is used in the treatment of cancer beside 5 fu widely prescribed oral fluoropyrimidine capecitabine xeloda could put dpd deficient patients at risk of experiencing severe or lethal toxicities as well
diktyoma or ciliary body medulloepithelioma or teratoneuroma is a rare tumor arising from primitive medullary epithelium in the ciliary body of the eye almost all diktyomas arise in the ciliary body although rarely they may arise from the optic nerve head or retina the name diktyoma comes from its characteristic findings on histology
dilaceration is a developmental disturbance in shape of teeth it refers to an angulation or a sharp bend or curve in the root or crown of a formed tooth
dilated cardiomyopathy dcm is a condition in which the heart becomes enlarged and cannot pump blood efficiently the decreased heart function can affect the lungs liver and other body systems dcm is one of the cardiomyopathies a group of diseases that affect primarily the heart muscle different cardiomyopathies have different causes and affect the heart in different ways in dcm a portion of the myocardium is dilated often without any obvious cause left or right ventricular systolic pump function of the heart is impaired leading to progressive heart enlargement via ventricular hypertrophy and ventricular dilation a process called ventricular remodeling dilated cardiomyopathy is the most common form of non ischemic cardiomyopathy it occurs more frequently in men than in women and is most common between the ages of 20 and 60 years about one in three cases of congestive heart failure chf is due to dilated cardiomyopathy dilated cardiomyopathy also occurs in children
a dilated pore also known as a dilated pore of winer is a cutaneous condition characterized by a solitary prominent open comedo on the face or upper trunk of an individual they can occur on either young or elderly individuals they are benign however they can be considered unsightly the only curative method of removal is a punch excision usually 1 – 3 mm lasers and other superficial means of removal have proven to be ineffective
in methods of abortion dilation and evacuation d e also sometimes called dilation and extraction is the dilation of the cervix and surgical evacuation of the contents of the uterus it is a method of abortion as well as a therapeutic procedure used after miscarriage to prevent infection by ensuring that the uterus is fully evacuated in various health care centers it may be called by different names d e dilation and evacuation erpoc evacuation of retained products of conception top or stop surgical termination of pregnancy d e normally refers to a specific second trimester procedure however some sources use the term d e to refer more generally to any procedure that involves the processes of dilation and evacuation which includes the first trimester procedures of manual and electric vacuum aspiration
the dim effect is a natural phenomenon named by brett c ratcliffe in which nature is said to mimic art the dim effect occurs when the following events occur in sequence 1 an element of nature never seen before and assumed not to exist is represented synthetically 2 the same element is discovered to actually exist in nature entirely without human intervention the dim effect is named after a 3 d animated character dim the rhinoceros beetle from the film a bug s life
in mathematics specifically set theory a dimensional operator on a set e is a function from the subsets of e to the subsets of e
in music a diminished triad also known as the minor flatted fifth m ♭ 5 is a triad consisting of two minor thirds above the root — if built on c a diminished triad would have a c an e ♭ and a g ♭ it resembles a minor triad with a lowered flattened fifth it can be represented by the integer notation 0 3 6 in the common practice period the diminished triad is considered dissonant or unstable because the dissonant diminished fifth symmetrically divides the octave the lack of tonal center or stability possession of a leading tone and the dominant function give the chord drive
in economics diminishing returns is the decrease in the marginal incremental output of a production process as the amount of a single factor of production is incrementally increased while the amounts of all other factors of production stay constant the law of diminishing returns states that in all productive processes adding more of one factor of production while holding all others constant ceteris paribus will at some point yield lower incremental per unit returns the law of diminishing returns does not imply that adding more of a factor will decrease the total production a condition known as negative returns though in fact this is common a common sort of example is adding more people to a job or assembling a car on a factory floor at some point adding more workers causes problems such as workers getting in each other s way or frequently finding themselves waiting for access to a part in all of these processes producing one more unit of output per unit of time will eventually cost increasingly more due to inputs being used less and less effectively the law of diminishing returns is a fundamental principle of economics it plays a central role in production theory
the dimroth rearrangement is a rearrangement reaction taking place with certain 1 2 3 triazoles where endocyclic and exocyclic nitrogen atoms switch place this organic reaction was discovered in 1909 by otto dimroth dimroth rearrangement with r a phenyl group the reaction takes place in boiling pyridine for 24 hours this type of triazole has an amino group in the 5 position after ring opening to a diazo intermediate c c bond rotation is possible with 1 3 migration of a proton certain 1 alkyl 2 iminopyrimidines also display this type of rearrangement pyrimidine dimroth in the first step is an addition reaction of water followed by ring opening of the hemiaminal to the aminoaldehyde followed by ring closure
in mathematics dini s criterion is a condition for the pointwise convergence of fourier series introduced by dini
in computer science the dining philosophers problem is an example problem often used in concurrent algorithm design to illustrate synchronization issues and techniques for resolving them it was originally formulated in 1965 by edsger dijkstra as a student exam exercise presented in terms of computers competing for access to tape drive peripherals soon after tony hoare gave the problem its present formulation
diogenes syndrome also known as senile squalor syndrome is a disorder characterized by extreme self neglect domestic squalor social withdrawal apathy compulsive hoarding of garbage or animals and lack of shame sufferers may also display symptoms of catatonia the condition was first recognized in 1966 and designated diogenes syndrome by clark et al the name derives from diogenes of sinope an ancient greek philosopher a cynic and an ultimate minimalist who allegedly lived in a large jar in athens not only did he not hoard but he actually sought human company by venturing daily to the agora therefore this eponym is considered to be a misnomer other possible terms are senile breakdown plyushkin s syndrome after a character from gogol s novel dead souls social breakdown and senile squalor syndrome frontal lobe impairment may play a part in the causation orrell et al 1989
diphallia penile duplication pd diphallic terata or diphallasparatus is a rare developmental abnormality in which a male infant is born with two penises the first reported case was by johannes jacob wecker in 1609 its occurrence is 1 in 5 5 million boys in the united states when diphallia is present it is usually accompanied by renal vertebral hindgut anorectal or other congenital anomalies there is also a higher risk of spina bifida infants born with pd and its related conditions have a higher death rate from various infections associated with their more complex renal or colorectal systems it is thought diphallia occurs in the fetus between the 23 rd and 25 th days of gestation when an injury chemical stress or malfunctioning homeobox genes hamper proper function of the caudal cell mass of the fetal mesoderm as the urogenital sinus separates from the genital tubercle and rectum to form the penis
diphtheria is an infection caused by the bacterium corynebacterium diphtheriae signs and symptoms may vary from mild to severe they usually start two to five days after exposure symptoms often come on fairly gradually beginning with a sore throat and fever in severe cases a grey or white patch develops in the throat this can block the airway and create a barking cough as in croup the neck may swell in part due to large lymph nodes a form of diphtheria that involves the skin eyes or genitals also exists complications may include myocarditis inflammation of nerves kidney problems and bleeding problems due to low blood platelets myocarditis may result in an abnormal heart rate and inflammation of the nerves may result in paralysis diphtheria is usually spread between people by direct contact or through the air it may also be spread by contaminated objects some people carry the bacteria without having symptoms but can still spread the disease to others there are three main types of c diphtheriae causing different severities of disease the symptoms are due to a toxin produced by the bacteria diagnosis can often be made based on the appearance of the throat with confirmation by culture previous infection may not prevent against future infection a vaccine known as diphtheria toxoid is effective for prevention and available in a number of formulations three or four doses given along with tetanus toxoid and acellular pertussis vaccine are recommended during childhood further doses are recommended every ten years protection can be verified by measuring the antitoxin level in the blood treatment is with the antibiotic erythromycin or penicillin g these antibiotics may also be used for prevention in those who have been exposed to the infection a surgical procedure known as a tracheostomy is sometimes needed to open the airway in severe cases in 2013 4 700 cases were officially reported down from nearly 100 000 in 1980 it is believed however that about a million cases occurred per year before the 1980 s it currently occurs most often in sub saharan africa india and indonesia in 2013 it resulted in 3 300 deaths down from 8 000 deaths in 1990 in areas where it is still common children are most affected it is rare in the developed world due to widespread vaccination in the united states 57 cases were reported between 1980 and 2004 death occurs in between 5 and 10 of those affected the disease was first described in the 5 th century bc by hippocrates the bacterium was discovered in 1882 by edwin klebs
diphyllobothriasis is the infection caused by tapeworms of the diphyllobothrium genus commonly diphyllobothrium latum
diplacusis also known as diplacusis binauralis or inter aural pitch difference ipd is a type of hearing disorder that is the perception of a single auditory stimulus as two separate sounds which may differ in pitch or in time it is typically though not exclusively experienced as a secondary symptom of sensorineural hearing loss although not all patients with sensory neural hearing loss may experience diplacusis or tinnitus onset is usually spontaneous and can occur at the time of an acoustic trauma or in the midst of an ear infection sufferers may experience the effect permanently or it may resolve on its own treatment includes a full medical examination as well as an audiological examination that may explain the nature of the problem if needed amplification may relieve the symptoms of diplacusis therapy in helping the patient understand the cause of the symptom and tinnitus retraining may provide some relief in at least some cases amplification makes no difference and there is no treatment other than waiting for natural resolution
diploblasty is a condition of the blastula in which there are two primary germ layers the ectoderm and endoderm diploblastic organisms are organisms which develop from such a blastula and include cnidaria and ctenophora formerly grouped together in the phylum coelenterata but later understanding of their differences resulted in their being placed in separate phyla the endoderm allows them to develop true tissue this includes tissue associated with the gut and associated glands the ectoderm on the other hand gives rise to the epidermis the nervous tissue and if present nephridia simpler animals such as sea sponges have one germ layer and lack true tissue organization all the more complex animals from flat worms to humans are triploblastic with three germ layers a mesoderm as well as ectoderm and endoderm the mesoderm allows them to develop true organs groups of diploblastic animals alive today include jellyfish corals sea anemones and comb jellies
diploid triploid mosaicism dtm is a chromosome disorder individuals with diploid triploid syndrome have some cells with three copies of each chromosome for a total of 69 chromosomes called triploid cells and some cells with the usual 2 copies of each chromosome for a total of 46 chromosomes called diploid cells having two or more different cell types is called mosaicism diploid triploid mosaicism can be associated with truncal obesity body facial asymmetry weak muscle tone hypotonia delays in growth mild differences in facial features fusion or webbing between some of the fingers and or toes syndactyly and irregularities in the skin pigmentation intellectual disabilities may be present but are highly variable from person to person ranging from mild to more severe the chromosome disorder is usually not present in the blood a skin biopsy or analyzing cells in the urine is needed to detect the triploid cells people usually have 46 chromosomes in the cells in the body chromosomes are the microscopically small structures in the nucleus of the body ’ s cells that carry genetic information in people with diploid triploid mosaicism two populations of cells co exist some cells called diploid have 46 chromosomes other cells called triploid have an extra set of 23 chromosomes making 69 in all triploidy is not the same as trisomy in trisomy there is an extra copy of just one chromosome making a total of 47 down ’ s syndrome is an example of trisomy with an extra copy of chromosome 21 in triploidy there is an extra copy of each of the 23 chromosomes making a total of 69 there are thought to be over 60 people living with this disorder all over the world it may not be a rare as we think as more and more cases are being diagnosed yearly the oldest living diagnosed is well in their 30 s the children with it are happy fun loving social kids and life expectancy seems to be getting longer and longer early intervention is the key although they can have a lot of physical needs they are full of joy and love the information out there about dtm is outdated it is not a death sentence other names for diploid triploid mosaic 1 diploidy triploidy 2 2 n 3 n mixoploidy 3 triploidy mosaicism 4 diploid triploid mosaicism 5 dtm 6 mosaic triploid
diplophonia also known as diphthongia is a phenomenon in which a voice is perceived as being produced with two concurrent pitches diplophonia is a result of vocal fold vibrations that are quasi periodic in nature it has been reported from old days but there are no uniform interpretation of established mechanisms it has been established that diplophonia can be caused by various vocal fold pathologies such as vocal folds polyp vocal fold nodule recurrent laryngeal nerve paralysis or vestibular fold hypertrophy
diplopia commonly known as double vision is the simultaneous perception of two images of a single object that may be displaced horizontally vertically diagonally i e both vertically and horizontally or rotationally in relation to each other it is usually the result of impaired function of the extraocular muscles eoms where both eyes are still functional but they cannot converge to target the desired object problems with eoms may be due to mechanical problems disorders of the neuromuscular junction disorders of the cranial nerves iii iv and vi that stimulate the muscles and occasionally disorders involving the supranuclear oculomotor pathways or ingestion of toxins diplopia can be one of the first signs of a systemic disease particularly to a muscular or neurological process and it may disrupt a person ’ s balance movement and or reading abilities
diplopodia is a congenital anomaly in tetrapods that involves duplication of elements of the foot on the hind limb it comes from the greek roots diplo double and pod foot diplopodia is often found in conjunction with other structural abnormalities and can be lethal it is more extreme than polydactyly the presence of extra digits
the dipygus deformity is a severe congenital deformity where the body axis forks left and right partway along the torso with the posterior end pelvis and legs duplicated myrtle corbin was a dipygus she married and had 5 children in human cases the inner two of the four hindquarters develop much smaller than normal this is a type of teras catadidymum monster twinned below another sort of deformity with extra legs can happen from a degenerated conjoined twin as may have happened with frank lentini with his third leg
in mathematics a dirac spectrum named after paul dirac is the spectrum of eigenvalues of a dirac operator on a riemannian manifold with a spin structure the isospectral problem for the dirac spectrum asks whether two riemannian spin manifolds have identical spectra the dirac spectrum depends on the spin structure in the sense that there exists a riemannian manifold with two different spin structures that have different dirac spectra
direct labour cost variance is the difference between the standard cost for actual production and the actual cost in production there are two kinds of labour variances labour rate variance is the difference between the standard cost and the actual cost paid for the actual number of hours labour efficiency variance is the difference between the standard labour hour that should have been worked for the actual number of units produced and the actual number of hours worked when the labour hours are valued at the standard rate
in variance analysis accounting direct material price variance is the difference between the standard cost and the actual cost for the actual quantity of material purchased it is one of the two components the other is direct material usage variance of direct material total variance
in variance analysis accounting direct material total variance is the difference between the actual cost of actual number of units produced and its budgeted cost in terms of material direct material total variance can be divided into two components the direct material price variance the direct material usage variance
in variance analysis direct material usage efficiency quantity variance is the difference between the standard quantity of materials that should have been used for the number of units actually produced and the actual quantity of materials used valued at the standard cost per unit of material it is one of the two components the other is direct material price variance of direct material total variance
directed attention fatigue daf is a neurological phenomenon that results from overuse of the brain ’ s inhibitory attention mechanisms which handle incoming distractions while maintaining focus on a specific task the greatest threat to a given focus of attention is competition from other stimuli that can cause a shift in focus this is because one maintains focus on a particular thought by inhibiting all potential distractions and not by strengthening that central mental activity directed attention fatigue occurs when a particular part of the brain ’ s global inhibitory system is overworked due to the suppression of increasing numbers of stimuli this temporary condition is not a clinical illness or a personality disorder it is rather a temporary fatigue of the inhibitory mechanisms in the brain according to inhibition theory it is natural for one to alternate between periods of attention and distraction although one ’ s efforts may involve very different tasks each incoming stimulus calls upon the same directed attention mechanism
in mathematics the dirichlet beta function also known as the catalan beta function is a special function closely related to the riemann zeta function it is a particular dirichlet l function the l function for the alternating character of period four
in mathematics the dirichlet or first type boundary condition is a type of boundary condition named after peter gustav lejeune dirichlet 1805 – 1859 when imposed on an ordinary or a partial differential equation it specifies the values that a solution needs to take on along the boundary of the domain the question of finding solutions to such equations is known as the dirichlet problem in engineering applications a dirichlet boundary condition may also be referred to as a fixed boundary condition
in mathematics the dirichlet conditions are sufficient conditions for a real valued periodic function f to be equal to the sum of its fourier series at each point where f is continuous moreover the behavior of the fourier series at points of discontinuity is determined as well it is the midpoint of the values of the discontinuity these conditions are named after peter gustav lejeune dirichlet the conditions are f must be absolutely integrable over a period f must have a finite number of extrema in any given bounded interval i e there must be a finite number of maxima and minima in the interval f must have a finite number of discontinuities in any given bounded interval however the discontinuity cannot be infinite these three conditions are satisfied if f is a function of bounded variation over a period
in mathematics a dirichlet problem is the problem of finding a function which solves a specified partial differential equation pde in the interior of a given region that takes prescribed values on the boundary of the region the dirichlet problem can be solved for many pdes although originally it was posed for laplace s equation in that case the problem can be stated as follows given a function f that has values everywhere on the boundary of a region in rn is there a unique continuous function u twice continuously differentiable in the interior and continuous on the boundary such that u is harmonic in the interior and u f on the boundary this requirement is called the dirichlet boundary condition the main issue is to prove the existence of a solution uniqueness can be proved using the maximum principle
dirofilariasis is an infection by parasites in the dirofilaria genus it can be caused by dirofilaria immitis dirofilaria repens dirofilaria tenuis
a dirty thunderstorm also volcanic lightning is a weather phenomenon that is related to the production of lightning in a volcanic plume a famous image of the phenomenon was photographed by carlos gutierrez and occurred in chile above the chaiten volcano it circulated widely on the internet other instances have been reported above alaska s mount augustine volcano iceland s eyjafjallajökull volcano and mount etna in sicily italy
disability is an impairment that may be physical cognitive intellectual mental sensory developmental or some combination of these that results in restrictions on an individual s ability to participate in what is considered normal in their everyday society a disability may be present from birth or occur during a person s lifetime disabilities is an umbrella term covering impairments activity limitations and participation restrictions an impairment is a problem in body function or structure an activity limitation is a difficulty encountered by an individual in executing a task or action while a participation restriction is a problem experienced by an individual in involvement in life situations thus disability is a complex phenomenon reflecting an interaction between features of a person ’ s body and features of the society in which he or she lives — world health organization disabilities disability is a contested concept with different meanings for different communities it may be used to refer to physical or mental attributes that some institutions particularly medicine view as needing to be fixed the medical model it may refer to limitations imposed on people by the constraints of an ableist society the social model or the term may serve to name a social identity claimed by people with disabilities the discussion over disability s definition arose out of disability activism in the u s and u k in the 1970 s which challenged how medical conceptions of human variation dominated popular discourse about disabilities and how these were reflected in common terminology e g handicapped cripple debates about proper terminology and their implied politics continue in disability communities and the academic field of disability studies in many countries the law requires that disabilities documented by a healthcare provider in order to assess which citizens qualify for disability benefits
in medical terminology disarticulation is the separation of two bones at their joint either naturally by way of injury or by a surgeon during amputation
a disaster is a serious disruption of the functioning of a community or a society involving widespread human material economic or environmental losses and impacts which exceeds the ability of the affected community or society to cope using its own resources in contemporary academia disasters are seen as the consequence of inappropriately managed risk these risks are the product of a combination of both hazards and vulnerability hazards that strike in areas with low vulnerability will never become disasters as in the case of uninhabited regions developing countries suffer the greatest costs when a disaster hits – more than 95 percent of all deaths caused by hazards occur in developing countries and losses due to natural hazards are 20 times greater as a percentage of gdp in developing countries than in industrialized countries
disaster convergence is the phenomenon of individuals or groups moving towards a disaster stricken area convergers have many reasons for heading towards a disaster area kendra and wachtendorf 2002 identified seven distinct categories of convergers these categories are mourners the anxious returners the curious the helpers the exploiters and the supporters
a disc protrusion is a disease condition which can occur in some vertebrates including humans in which the outermost layers of the anulus fibrosus of the intervertebral discs of the spine are intact but bulge when one or more of the discs are under pressure many disk abnormalities seen on mri that are loosely referred to herniation are actually just incidental findings these may be unrelated to any symptoms and are just bulges of the annulus fibrosus jensen and colleagues in an mri study of the lumbar spine in 98 asymptomatic adults found that in more than half there was a symmetrical extension of a disc or discs beyond the margins of the interspace bulging in 27 percent there was a focal or asymmetrical extension of the disc beyond the margin of the interspace protrusion and in only 1 percent was there more extreme extension of the disc extrusion or sequestration these findings emphasize the importance of using precise terms in describing the imaging abnormalities and evaluating them strictly in the context of the patient s symptoms a disc protrusion may progress to a spinal disc herniation a condition in which there is a tear in the anulus fibrosus
discernment is the ability to obtain sharp perceptions or to judge well or the activity of so doing in the case of judgment discernment can be psychological or moral in nature in the sphere of judgment discernment involves going past the mere perception of something and making nuanced judgments about its properties or qualities considered as a virtue a discerning individual is considered to possess wisdom and be of good judgement especially so with regard to subject matter often overlooked by others
discitis or diskitis is an infection in the intervertebral disc space that affects different age groups in adults it can lead to severe consequences such as sepsis or epidural abscess but can also spontaneously resolve especially in children under 8 years of age discitis occurs post surgically in approximately 1 2 percent of patients after spinal surgery
a disclination is a line defect in which rotational symmetry is violated in analogy with dislocations in crystals the term disinclination for liquid crystals first used by f c frank and since then has been modified to its current usage disclination it is a defect in the orientation of director whereas a dislocation is a defect in positional order
discoid lupus erythematosus dle is a chronic skin condition of sores with inflammation and scarring favoring the face ears and scalp and at times on other body areas these lesions develop as a red inflamed patch with a scaling and crusty appearance the center areas may appear lighter in color with a rim darker than the normal skin discoid lupus erythematosus can be divided into localized generalized and childhood discoid lupus erythematosus
the discounted payback period is the amount of time that it takes to cover the cost of a project by adding positive discounted cash flow coming from the profits of the project the advantage of using the discounted payback period over the payback period is that it takes into account time value of money
discoverability is the ability of something especially a piece of content or information to be found discoverability is a concern in library and information science many aspects of digital media software and web development and in marketing since a thing cannot be used if people cannot find it or don t understand what it s for metadata or information about information such as a book s title a product s description or a website s keywords affects how discoverable something is organizing information by putting it into alphabetical order or including it in a search engine is an example of how to improve discoverability discoverability is related to but different from accessibility and usability other qualities that affect the usefulness of a piece of information
a discrepancy function is a mathematical function which describes how closely a structural model conforms to observed data larger values of the discrepancy function indicate a poor fit of the model to data in general the parameter estimates for a given model are chosen so as to make the discrepancy function for that model as small as possible there are several basic types of discrepancy functions including maximum likelihood ml generalized least squares gls and ordinary least squares ols which are considered the classical discrepancy functions discrepancy functions all meet the following basic criteria they are non negative i e always greater than or equal to zero they are zero only if the fit is perfect i e if the model and parameter estimates perfectly reproduce the observed data the discrepancy function is a continuous function of the elements of s the sample covariance matrix and σ θ the reproduced estimate of s obtained by using the parameter estimates and the structural model in order for maximum likelihood to meet the first criterion it is used in a revised form as the deviance
discrete papular lichen myxedematosus is a skin condition caused by fibroblasts producing abnormally large amounts of mucopolysaccharides characterized by the occurrence of waxy flesh colored papules
in numerical analysis computational physics and simulation discretization error or truncation error is the error inherent in discretization it results from the fact that a function of a continuous variable is represented in the computer by a finite number of evaluations for example on a lattice discretization error can usually be reduced by using a more finely spaced lattice with an increased computational cost whenever continuous data is discretized there is always some amount of discretization error the goal is to reduce the amount to a level considered negligible for the modeling purposes at hand
a disease is a particular abnormal condition a disorder of a structure or function that affects part or all of an organism the study of disease is called pathology which includes the causal study of etiology disease is often construed as a medical condition associated with specific symptoms and signs it may be caused by external factors such as pathogens or it may be caused by internal dysfunctions particularly of the immune system such as an immunodeficiency or a hypersensitivity including allergies and autoimmunity in humans disease is often used more broadly to refer to any condition that causes pain dysfunction distress social problems or death to the person afflicted or similar problems for those in contact with the person in this broader sense it sometimes includes injuries disabilities disorders syndromes infections isolated symptoms deviant behaviors and atypical variations of structure and function while in other contexts and for other purposes these may be considered distinguishable categories diseases can affect people not only physically but also emotionally as contracting and living with a disease can alter the affected person s perspective on life death due to disease is called death by natural causes there are four main types of disease infectious diseases deficiency diseases genetic diseases both hereditary and non hereditary and physiological diseases diseases can also be classified as communicable and non communicable the deadliest diseases in humans are coronary artery disease blood flow obstruction followed by cerebrovascular disease and lower respiratory infections
disease informatics is the application of information science in defining the diseases with least error identifying most of the targets to combat a cluster of diseases disease causal chain and designing a holistic solution health strategy to the problem
the disease model of addiction describes an addiction as a disease with biological neurological genetic and environmental sources of origin the traditional medical model of disease requires only that an abnormal condition be present that causes discomfort dysfunction or distress to the individual afflicted the contemporary medical model attributes addiction in part to changes in the brain s mesolimbic pathway the medical model also takes into consideration that such disease may be the result of other biological psychological or sociological entities despite an incomplete understanding of the mechanisms of these entities the common biomolecular mechanisms underlying all forms of addiction – creb and δfosb – were reviewed by eric j nestler in a 2013 review
the modern disease theory of alcoholism states that problem drinking is sometimes caused by a disease of the brain characterized by altered brain structure and function the american medical association ama declared that alcoholism was an illness in 1956 in 1991 the ama further endorsed the dual classification of alcoholism by the international classification of diseases under both psychiatric and medical sections
in medicine disequilibrium refers to an impaired sense of equilibrioception it is one of the causes of dizziness
disinflation is a decrease in the rate of inflation – a slowdown in the rate of increase of the general price level of goods and services in a nation s gross domestic product over time it is the opposite of reflation disinflation occurs when the increase in the “ consumer price level ” slows down from the previous period when the prices were rising if the inflation rate is not very high to start with disinflation can lead to deflation – decreases in the general price level of goods and services for example if the annual inflation rate for the month of january is 5 and it is 4 in the month of february the prices disinflated by 1 but are still increasing at a 4 annual rate again if the current rate is 1 and it is – 2 for the following month prices disinflated by 3 i e 1 – 2 and are decreasing at a 2 annual rate
disinhibited attachment disorder of childhood dad according to the international classification of diseases icd 10 is defined as a particular pattern of abnormal social functioning that arises during the first five years of life and that tends to persist despite marked changes in environmental circumstances e g diffuse nonselectively focused attachment behaviour attention seeking and indiscriminately friendly behaviour poorly modulated peer interactions depending on circumstances there may also be associated emotional or behavioural disturbance – f 94 2 of the icd 10 disinhibited attachment disorder is a subtype of the icd 10 category f 94 disorders of social functioning with onset specific to childhood and adolescence the other subtype of f 94 is reactive attachment disorder of childhood rad – f 94 1 synonymous or similar disorders include affectionless psychopathy and institutional syndrome within the icd 10 category scheme disinhibited attachment disorder specifically excludes asperger syndrome f 84 5 hospitalism in children f 43 2 and hyperkinetic disorders f 90
disinhibited social engagement disorder dsed or disinhibited attachment disorder of childhood is an attachment disorder that consists of a pattern of behavior in which a child actively approaches and interacts with unfamiliar adults and which significantly impairs young children ’ s abilities to relate interpersonally to adults and peers for example sitting on the lap of a stranger or peer or leaving with a stranger dsed is exclusively a childhood disorder and is not diagnosed before the age of nine months or after the age of five infants and very young children are at risk if they receive inconsistent or insufficient care from a primary caregiver
in psychology disinhibition is a lack of restraint manifested in disregard for social conventions impulsivity and poor risk assessment disinhibition affects motor instinctual emotional cognitive and perceptual aspects with signs and symptoms similar to the diagnostic criteria for mania hypersexuality hyperphagia and aggressive outbursts are indicative of disinhibited instinctual drives
disjunctive cognition is a common phenomenon in dreams first identified by psychoanalyst mark blechner in which two aspects of cognition do not match each other the dreamer is aware of the disjunction yet that does not prevent it from remaining the most frequent disjunction is between appearance and identity such as i knew it was my mother even though it didn t look like her the dreamer recognizes a character s identity even though the appearance does not match the identity such dreams are usually not experienced as bizarre despite the fact that such a statement in waking life would be considered psychotic in waking life most people would assume that they misidentified the person and correct for it but not in dreams disjunctive cognition can also involve time perception it is quite common to dream that as an adult one goes back to a time and place of one s childhood in this case the perceived age of the dreamer is disjunctive with the setting of the dream it is much less common to perceive the opposite dreaming of oneself as a child where the time and place are that of one s adulthood however it is common to dream of other people whom one knew at an earlier age appearing in the present this is especially frequent in the dreams of people who have lost close relatives for example aharon appelfeld reported i dreamed about my parents they had not aged since we were together sixty three years ago in prague and their faces expressed amazement that i had grown older we were briefly united in mutual astonishment and i knew that i had something important to tell them but as in every profound dream i could not get the words out blechner calls disjunctive cognitions the commonplace bizarreness of dreamlife some things that happen in dreams feel bizarre to the dreamer but disjunctive cognitions usually do not another commonplace bizarreness of dreams is the interobject in which the dreamer sees something between two objects as in i dreamt of something between a swimming pool and an aqueduct or between a cell phone and a baby disjunctive cognitions reveal much about how the brain is organized blechner has suggested that whenever disjunctive cognitions occur the two aspects of cognition that are disjunctive are handled in different parts of the brain whose mutual integration is suppressed or shifted during sleep disjunctive cognitions between what the person looks like and who the person is suggest two brain systems for those aspects of perception this is supported by research in neuropsychology and neurobiology for example some people who have suffered strokes or other brain damage have a syndrome known as prosopagnosia a prosopagnosic man may look at his wife of 50 years see all of her features clearly and yet not recognize who she is in such people the process of seeing is intact but the process of facial recognition is damaged there is also the phenomenon of capgras syndrome in which a person may feel that a close relative is actually an impostor the features of the relative are recognizable but the person s identity is not and there is also fregoli delusion in which a person may mistakenly identify strangers as people he actually knows in all of these syndromes there is a disjunction between the appearance and perceived identity of the person neurobiological research has identified separate areas of the brain responsible for recognizing faces in humans identifying unfamiliar faces activates one region of the brain the fusiform face area while recognizing familiar faces also activates another area of the brain in the lateral midtemporal cortex a similar division of function is found in macaque monkeys such findings indicate that the process of recognizing faces may be achieved by special parts of the brain that are different from the brain areas involved in analyzing the general visual features of things since the brain has separate systems for deciding what a person looks like and who the person is this division of labor may be responsible not only for disjunctive cognitions but also the phenomenon of transference in psychoanalytic treatment patients frequently experience transference in which the psychoanalyst is perceived to be very much like someone from the patient s past as in disjunctive cognitions of dreams the patient may feel you look like dr x but you feel like my mother the separate areas of the brain involved in telling us what the person looks like and who the person is may give a neurobiological basis for transference the phenomenon in which we know who a person is yet we react emotionally to that person as if they are someone else
the term disk space is an amount of computer storage space on random access memory devices such as on a hard drive floppy or usb flash drive disk space units are commonly measured in large numbers of bytes such as kilobytes megabytes and gigabytes with each unit 1024 times larger than the previous unit the term originated in the 1950 s for the storage area on a hard disk drive which internally had disk shaped platters to rotate quickly as storage devices have been created in other shapes the term disk space has still been used to refer to areas of permanent storage on various storage devices the total disk space can span multiple devices such as areas on an array of disk drives the broader term storage space is so widely used that it can be mistaken for property storage as with items stored in a closet or storage bin hence the term disk space has remained in use even when the storage devices are no longer shaped like disks when storage of data is not permanent then the common term memory space is often used instead
a dislocated shoulder occurs when the humerus separates from the scapula at the shoulder joint glenohumeral joint the shoulder joint has the greatest range of motion of any joint at the cost of low joint stability and it is therefore particularly susceptible to subluxation partial dislocation and dislocation approximately half of major joint dislocations seen in emergency departments involve the shoulder
in materials science a dislocation is a crystallographic defect or irregularity within a crystal structure the presence of dislocations strongly influences many of the properties of materials the theory describing the elastic fields of the defects was originally developed by vito volterra in 1907 but the term dislocation to refer to a defect on the atomic scale was coined by g i taylor in 1934 some types of dislocations can be visualized as being caused by the termination of a plane of atoms in the middle of a crystal in such a case the surrounding planes are not straight but instead they bend around the edge of the terminating plane so that the crystal structure is perfectly ordered on either side the analogy with a stack of paper is apt if half a piece of paper is inserted in a stack of paper the defect in the stack is only noticeable at the edge of the half sheet the two primary types of dislocations are edge dislocations and screw dislocations mixed dislocations are intermediate between these mathematically dislocations are a type of topological defect sometimes called a soliton dislocations behave as stable particles they can move around but maintain their identity two dislocations of opposite orientation can cancel when brought together but a single dislocation typically cannot disappear on its own
acquired hip dislocation has the highest incidence rate immediately after hip replacement surgery and continues to have a high level for possibility of incidence throughout the first three months following the surgery following a primary total hip replacement surgery 3 9 of patients experience hip dislocation during the twenty six postoperative weeks following a revision total hip replacement surgery approximately 14 4 of patients experience hip dislocation during the twenty six postoperative weeks the incidence of hip dislocation following hip replacement surgery greatly depends on patient surgical and hip implant factors preoperative hip range is the most likely the most influential contribution as to whether a hip is able to remain stable or not because hip stability greatly depends on hip range of motion it is crucial for a hip ’ s postoperative range of motion to fall within a certain range in order to ensure maximum stability following partial or total hip replacement surgery patients with 115 degrees or greater of combined preoperative adduction internal rotation and adduction as well as a posterior approach experienced hip dislocation at a considerably higher frequency than patients who had less than 115 degrees of combined hip range of motion in addition to the degrees of range of motion a patient possesses post surgery size of the femoral head is another large contributing factor to the stability of the hip high preoperative motion in combination with a posterior approach and femoral head size that is less than 32 mm had the highest hip dislocation rate in general the larger the head of the femur post surgery the less likely a patient is to experience dislocation this is because during the replacement surgery a patient ’ s “ ball and socket ” of the femur head and hip socket are changed and no longer fit together in the perfect way they did prior to surgery when a femur head is smaller than 32 mm post surgery the looser the “ ball ” femur head fits inside the hip “ socket ” therefore increasing the likelihood for the femur to slip and slide out of the socket causing hip dislocation
dislocations occur when two bones that originally met at the joint detach dislocations should not be confused with subluxation subluxation is when the joint is still partially attached to the bone when a person has a dislocated jaw it is difficult to open and close the mouth dislocation can occur following a series of events if the jaw locks while open or unable to close if the jaw is dislocated it may cause an extreme headache or inability to concentrate when the muscle s alignment is out of sync a pain will occur due to unwanted rotation of the jaw if the pain remains constant it may require surgery to realign the jaw depending on the severity of the jaw s dislocation pain relief such as paracetamol may assist to alleviate the initial chronic pain if the pain relief is taken for an extended period of time it may negatively affect the person while talking eating drinking etc
disorder of written expression is a type of learning disability in which a person ’ s writing ability falls substantially below normally expected range based on the individual ’ s age educational background and measured intelligence poor writing skills must interfere significantly with academic progress or daily activities that involves written expression spelling grammar handwriting punctuation word usage etc this disorder is also generally concurrent with disorders of reading and or mathematics as well as disorders related to behavior since it is so often associated with other learning disorders and mental problems it is uncertain whether it can appear by itself the prevalence of disorder of written expression is estimated to be of a similar frequency to other learning disorders between 3 5 a diagnosis can be made based on results of several assessments
in the study of stochastic processes in mathematics a disorder problem or quickest detection problem formulated by kolmogorov is the problem of using ongoing observations of a stochastic process to detect as soon as possible when the probabilistic properties of the process have changed this is a type of change detection problem an example case is to detect the change in the drift parameter of a wiener process
disorders of calcium metabolism occur when the body has too little or too much calcium the serum level of calcium is closely regulated within a fairly limited range in the human body in a healthy physiology extracellular calcium levels are maintained within a tight range through the actions of parathyroid hormone vitamin d and the calcium sensing receptor disorders in calcium metabolism can lead to hypocalcemia decreased plasma levels of calcium or hypercalcemia elevated plasma calcium levels
disorders of consciousness are organic mental disorders in which there is impairment of the ability to maintain awareness of self and environment and to respond to environmental stimuli dysfunction of the cerebral hemispheres or brain stem reticular formation may result in this condition consciousness is the state of awareness of self and environment and responsiveness to external stimulation and inner need unconsciousness is a state of unawareness of self and environment or a suspension of those mental activities by which people are made aware of themselves and their environment coupled always with a diminished responsiveness to environmental stimuli and remain behaviorally unresponsive to all external stimuli sleep is a recurrent reversible physiologic form of reduced consciousness in which the responsiveness of brain systems responsible for cognitive function is globally reduced so that the brain does not respond readily to environmental stimuli a key difference between sleep and coma is that sleep is intrinsically reversible on sufficient stimulation to a normal waking state in contrast if patients with pathologic alterations of consciousness can be awakened at all they rapidly fall back into a sleep like state when stimulation ceases disorder of consciousness leading to acute confusional state and coma are one of the commonest neurological emergency in clinical practice over last century there are long list of causes leading to alteration of consciousness classical approach to reach the final diagnosis depends on systematic approach
disorders of sex development dsd sometimes referred to as disorders of sex differentiation or differences of sex development are medical conditions involving the reproductive system more specifically these terms refer to congenital conditions in which development of chromosomal gonadal or anatomical sex is atypical the term has been controversial the world health organization and many medical journals still reference dsds as intersex traits or conditions the council of europe and inter american commission on human rights have called for a review of medical classifications that unnecessarily medicalize intersex traits
disorganized schizophrenia also known as hebephrenia is a subtype of schizophrenia although it is not recognized in the latest version of the diagnostic and statistical manual of mental disorders disorganized schizophrenia is thought to be an extreme expression of the disorganization syndrome that has been hypothesized to be one aspect of a three factor model of symptoms in schizophrenia the other factors being reality distortion involving delusions and hallucinations and psychomotor poverty lack of speech lack of spontaneous movement and various aspects of blunting of emotion
disparagement in united states trademark law is a statutory cause of action that permits a party to petition the trademark trial and appeal board ttab of the patent and trademark office pto to cancel a trademark registration that may disparage or falsely suggest a connection with persons living or dead institutions beliefs or national symbols or bring them into contempt or disrepute unlike claims regarding the validity of the mark a disparagement claim can be brought at any time subject to equitable defenses such as laches
disparity of worship or disparity of cult disparitas cultus is a diriment impediment in roman catholic canon law a reason why a marriage can not be validly contracted without a dispensation stemming from one person being certainly baptized and the other certainly not baptized the reasons for this impediment is that the marriage will not be a sacrament with one spouse unbaptized that the unbaptized person s views on marriage may be incompatible with the catholic views and that such a marriage may hinder the practice of religion on part of the catholic spouse and any children disparity of worship does not affect the marriage of a catholic or baptized non catholic with one whose baptism even after careful investigation concerning the baptismal ceremony or its validity remains doubtful neither does it in any way influence the marriage of two who after diligent examination are still considered doubtfully baptized a marriage between a catholic and a baptized non catholic is a mixed marriage though sometimes referred to by this term the permission of the bishop is required merely to make the union licit the marriage is valid but illicit without it disparity of worship can be dispensed for grave reasons and on the promises usually written from the spouses the unbaptized not to interfere with the spouse s practice of religion or the raising of the children in religion the catholic to practice the catholic religion and raise the children in it
in optics dispersion is the phenomenon in which the phase velocity of a wave depends on its frequency media having this common property may be termed dispersive media sometimes the term chromatic dispersion is used for specificity although the term is used in the field of optics to describe light and other electromagnetic waves dispersion in the same sense can apply to any sort of wave motion such as acoustic dispersion in the case of sound and seismic waves in gravity waves ocean waves and for telecommunication signals propagating along transmission lines such as coaxial cable or optical fiber in optics one important and familiar consequence of dispersion is the change in the angle of refraction of different colors of light as seen in the spectrum produced by a dispersive prism and in chromatic aberration of lenses design of compound achromatic lenses in which chromatic aberration is largely cancelled uses a quantification of a glass s dispersion given by its abbe number v where lower abbe numbers correspond to greater dispersion over the visible spectrum in some applications such as telecommunications the absolute phase of a wave is often not important but only the propagation of wave packets or pulses in that case one is interested only in variations of group velocity with frequency so called group velocity dispersion gvd
contrast in visual perception is the difference in appearance of two or more parts of a field seen simultaneously or successively hence brightness contrast lightness contrast color contrast simultaneous contrast successive contrast etc contrast in physics is a quantity intended to correlate with the perceived brightness contrast usually defined by one of a number of formulae see below which involve e g the luminances of the stimuli considered for example δl l near the luminance threshold known as weber contrast or lh ll for much higher luminances a contrast can also be due to differences of chromaticity specified by colorimetric characteristics e g the color difference δe cie 1976 ucs visual information is always contained in some kind of visual contrast thus contrast is an essential performance feature of electronic visual displays the contrast of electronic visual displays depends on the electrical driving analog or digital input signal on the ambient illumination and on the direction of observation i e viewing direction
display lag is a phenomenon associated with some types of liquid crystal displays lcds like smartphones and computers and nearly all types of high definition televisions hdtvs it refers to latency or lag measured by the difference between the time there is a signal input and the time it takes the input to display on the screen this lag time has been measured as high as 68 ms or the equivalent of 3 4 frames on a 60 hz display display lag is not to be confused with pixel response time currently the majority of manufacturers do not include any specification or information about display latency on the screens they produce
in object oriented programming the dispose pattern is a design pattern for resource management in this pattern a resource is held by an object and released by calling a method – usually called close dispose free release or similar – which releases any resources the object is holding onto many languages offer language constructs to avoid having to call the dispose method explicitly in common situations the dispose pattern is primarily used in languages whose runtime environment have automatic garbage collection see motivation below and thus may be styled as manual resource management in languages with automatic memory management
dispositional affect similar to mood is a personality trait or overall tendency to respond to situations in stable predictable ways this trait is expressed by the tendency to see things in a positive or negative way people with high positive affectivity tend to perceive things through pink lens while people with high negative affectivity tend to perceive things through black lens the level of dispositional affect affects the sensations and behavior immediately and most of the time in unconscious ways and its effect can be prolonged between a few weeks to a few months research shows that there is a correlation between dispositional affect both positive and negative and important aspects in psychology and social science such as personality culture decision making negotiation psychological resilience and coping with stressful life events that is why this topic is important both in social psychology research and organizational psychology research
disruptive pattern camouflage uniform dpcu also nicknamed auscam or jelly bean camo is a five colour military camouflage pattern used by the australian defence force it was developed and tested during the late 1970 s and early 1980 s the dpcu will be replaced by the australian multicam camouflage uniform amcu which uses an australian multi camouflage pattern based on multicam
disruptive mood dysregulation disorder dmdd is a mental disorder in children and adolescents characterized by a persistently irritable or angry mood and frequent temper outbursts that are disproportionate to the situation and significantly more severe than the typical reaction of same aged peers the symptoms of dmdd resemble those of attention deficit hyperactivity disorder adhd oppositional defiant disorder odd anxiety disorders and childhood bipolar disorder dmdd first appeared as a disorder in the diagnostic and statistical manual of mental disorders fifth edition dsm 5 in 2013 and is classified as a depressive disorder treatments include medication to manage mood symptoms as well as individual and family therapy to address emotion regulation skills children with dmdd are at risk for developing depression and anxiety later in life
dissecting cellulitis of the scalp also known as dissecting scalp cellulitis dissecting folliculitis of the scalp perifolliculitis capitis abscedens et suffodiens of hoffman perifolliculitis abscedens et suffodiens or folliculitis abscedens et suffodiens is an inflammatory condition of the scalp that can lead to scarring alopecia which begins with deep inflammatory nodules primarily over occiput that progresses to coalescing regions of boggy scalp boggy tissue has a high fluid level that results in a spongy feeling isotretinoin proves to be the medicine of choice for the treatment of the disease
in medical pathology a dissection is a tear within the wall of a blood vessel which allows blood to separate the wall layers by separating a portion of the wall of the artery a layer of the tunica intima or tunica media a dissection creates two lumens or passages within the vessel the native or true lumen and the false lumen created by the new space within the wall of the artery
in geometry a dissection problem is the problem of partitioning a geometric figure such as a polytope or ball into smaller pieces that may be rearranged into a new figure of equal content in this context the partitioning is called simply a dissection of one polytope into another it is usually required that the dissection use only a finite number of pieces the bolyai – gerwien theorem states that any polygon may be dissected into any other polygon of the same area it is not true however that any polyhedron has a dissection into any other polyhedron of the same volume this process is possible however for any two honeycombs such as cube in three dimension and any two zonohedra of equal volume in any dimension a dissection into triangles of equal area is called an equidissection most polygons cannot be equidissected and those that can often have restrictions on the possible numbers of triangles for example monsky s theorem states that there is no odd equidissection of a square
disseminated coccidioidomycosis also known as coccidioidal granuloma is a systemic infection with coccidioides immitis in which 15 20 of people develop skin lesions
disseminated disease refers to a diffuse disease process generally either infectious or neoplastic the term may sometimes also characterize connective tissue disease a disseminated infection for example has extended beyond its origin or nidus and involved the bloodstream to seed other areas of the body similarly one can view metastatic cancer as a disseminated infection in that it has extended into the bloodstream or into the lymphatic system and thus seeded distant sites a process known as metastasis disseminated disease often contrasts localized disease
disseminated intravascular coagulation dic also known as disseminated intravascular coagulopathy or less commonly as consumptive coagulopathy is a pathological process characterized by the widespread activation of the clotting cascade that results in the formation of blood clots in the small blood vessels throughout the body this leads to compromise of tissue blood flow and can ultimately lead to multiple organ damage in addition as the coagulation process consumes clotting factors and platelets normal clotting is disrupted and severe bleeding can occur from various sites dic does not occur by itself but only as a complicating factor from another underlying condition usually in those with a critical illness the combination of widespread loss of tissue blood flow and simultaneous bleeding leads to an increased risk of death in addition to that posed by the underlying disease dic can be overt and severe in some cases but milder and insidious in others the diagnosis of dic depends on the findings of characteristic laboratory tests and clinical background treatment is mainly geared towards the underlying condition
disseminated superficial actinic porokeratosis dsap is a non contagious skin condition with apparent genetic origin in the sart 3 gene it most often presents in sun exposed areas of the body some dsap cases have been reported in patients with acute immune compromised situations particularly in the elderly for those with sun damaged skin the lesions usually begin to appear in the patient s 20 s and increase in number and visibility in the 40 s or 50 s commonly though not always the number and visibility of lesions is in direct proportion to the amount of sun damage to the affected area lesions generally are characterized by an irregularly shaped thread like ring that is usually the size of a pencil eraser though lesions vary and may be half or double that size the thread like ring is very thin much like fabric thread for sewing and raised such that it is both palpable and visible the interior of the ring may be rough like sandpaper or smooth the interior is often discolored though colors vary from patient to patient lesions due to their vascular nature can also vary according to body temperature environmental temperatures and other external stimuli the internal ring color is most often reddish purplish pink or brown some patients report itching and irritation associated with the condition and many report no notable sensation although no known hormonal link has been found dsap occurs more commonly in women a study in 2000 was done on a chinese family in which a locus for a gene was located
dissent aversion is the judicial phenomenon that implies that judges do not like dissenting opinions nor do they like to dissent themselves a common example is as follows on a panel of three judges only one feels strongly about the decision one of the two remaining may side with the first judge leaving the third judge with the option of dissenting on an issue they do not feel strongly about or siding with the majority judges dislike dissent for many reasons dissent aversion can come from these sources it frays collegiality judges have to work together in the future it magnifies the majority opinion it is additional work it detracts from the significance of their own majority opinions dissent is more frequent in us federal courts of appeals where the number of judges is higher according to some research this is because the larger the court the less frequently judges must work with each other and accordingly have less incentive to extend courtesy and favors
in phonology particularly within historical linguistics dissimilation is a phenomenon whereby similar consonants or vowels in a word become less similar for example when a r sound occurs before another in the middle of a word in rhotic dialects of english the first tends to drop out as in beserk for berserk supprise for surprise paticular for particular and govenor for governor – this does not affect the pronunciation of government which has only one r but english government tends to be pronounced goverment dropping out the first n an example where a relatively old case of phonetic dissimilation has been artificially undone in the spelling is english colonel whose standard pronunciation is kərnəl in english it was formerly spelt coronel and is a borrowing from french coronnel which arose as a result of dissimilation from italian colonnello
dissociated sensory loss is a pattern of neurological damage caused by a lesion to a single tract in the spinal cord which involves selective loss of fine touch and proprioception without loss of pain and temperature or vice versa understanding the mechanisms behind these selective lesions requires a brief discussion of the anatomy involved loss of pain and temperature are due to damage to the lateral spinothalamic tracts which cross the central part of the cord close to the level where they enter it and travel up the spinal column on the opposite side to the one they innervate i e they ascend contralaterally note that a lesion of the lateral spinothalamic tract at a given level will not result in sensory loss for the dermatome of the same level this is due to the fibers of the tract of lissauer which transmit the neuron one or two levels above the affected segment thus bypassing the segmental lesion on the contralateral side loss of fine touch and proprioception are due to damage to the dorsal columns which do not cross the cord until the brainstem and so travel up the column on the same side to the one they innervate i e they ascend ipsilaterally this means that a lesion of the dorsal columns will cause loss of touch and proprioception below the lesion and on the same side as it while a lesion of the spinothalamic tracts will cause loss of pain and temperature below the lesion and on the opposite side to it dissociated sensory loss always suggests a focal lesion within the spinal cord or brainstem the location of cord lesions affects presentation for instance a central lesion such as that of syringomyelia will knock out second order neurons of the spinothalamic tract as they cross the centre of the cord and will cause loss of pain and temperature without loss of fine touch or proprioception other causes of dissociated sensory loss include diabetes mellitus syringomyelia brown séquard syndrome lateral medullary syndrome aka wallenberg s syndrome anterior spinal artery thrombosis tangier disease subacute combined degeneration multiple sclerosis tabes dorsalis friedreich s ataxia or other spinocerebellar degeneration
dissociated vertical deviation dvd is an eye condition which occurs in association with a squint typically infantile esotropia the exact cause is unknown although it is logical to assume it is from faulty innervation of eye muscles
dissociative disorders dd are conditions that involve disruptions or breakdowns of memory awareness identity or perception people with dissociative disorders use dissociation a defense mechanism pathologically and involuntarily dissociative disorders are thought to primarily be caused by psychological trauma the dissociative disorders listed in the american psychiatric association s dsm 5 are as follows dissociative identity disorder formerly multiple personality disorder the alternation of two or more distinct personality states with impaired recall among personality states in extreme cases the host personality is unaware of the other alternating personalities however the alternate personalities are aware of all the existing personalities this category now includes the old derealization disorder category dissociative amnesia formerly psychogenic amnesia the temporary loss of recall memory specifically episodic memory due to a traumatic or stressful event it is considered the most common dissociative disorder amongst those documented this disorder can occur abruptly or gradually and may last minutes to years depending on the severity of the trauma and the patient dissociative fugue formerly psychogenic fugue is now subsumed under the dissociative amnesia category it is described as reversible amnesia for personal identity usually involving unplanned travel or wandering sometimes accompanied by the establishment of a new identity this state is typically associated with stressful life circumstances and can be short or lengthy depersonalization disorder periods of detachment from self or surrounding which may be experienced as unreal lacking in control of or outside of self while retaining awareness that this is only a feeling and not a reality the old category of dissociative disorder not otherwise specified is now split into two other specified dissociative disorder and unspecified dissociative disorder these categories are used for forms of pathological dissociation that do not fully meet the criteria of the other specified dissociative disorders or if the correct category has not been determined both dissociative amnesia and dissociative fugue usually emerge in adulthood and rarely occur after the age of 50 the icd 10 classifies conversion disorder as a dissociative disorder while the dsm iv classifies it as a somatoform disorder
dissociative disorder not otherwise specified ddnos is a mental health diagnosis for pathological dissociation that matches the dsm iv criteria for a dissociative disorder but does not fit the full criteria for any of the specifically identified subtypes which include depersonalization disorder dissociative amnesia dissociative fugue and dissociative identity disorder the international statistical classification of diseases and related health problems icd 10 refers to the diagnosis as dissociative disorder unspecified examples of ddnos include ganser s syndrome disorders similar to dissociative identity disorder chronic dissociative states as a result of being exposed to coercive persuasion and derealization unaccompanied by depersonalization ddnos is the most common dissociative disorder and is diagnosed in 40 of dissociative disorder cases it is often co morbid with other mental illnesses such as complex posttraumatic stress disorder major depressive disorder personality disorders substance abuse disorders and eating disorders
dissociative identity disorder did previously known as multiple personality disorder mpd is a mental disorder characterized by at least two distinct and relatively enduring identities or dissociated personality states that alternately show in a person s behavior accompanied by memory impairment for important information not explained by ordinary forgetfulness these symptoms are not accounted for by substance abuse seizures other medical conditions nor by imaginative play in children diagnosis is often difficult as there is considerable comorbidity with other mental disorders malingering should be considered if there is possible financial or forensic gain as well as factitious disorder if help seeking behavior is prominent did is one of the most controversial psychiatric disorders with no clear consensus on diagnostic criteria or treatment research on treatment efficacy has been concerned primarily with clinical approaches and case studies dissociative symptoms range from common lapses in attention becoming distracted by something else and daydreaming to pathological dissociative disorders no systematic empirically supported definition of dissociation exists it is not the same as schizophrenia although neither epidemiological surveys nor longitudinal studies have been conducted it is generally believed that did rarely resolves spontaneously symptoms are said to vary over time in general the prognosis is poor especially for those with comorbid disorders there are few systematic data on the prevalence of did the international society for the study of trauma and dissociation states that the prevalence is between 1 and 3 in the general population and between 1 and 5 in inpatient groups in europe and north america did is diagnosed more frequently in north america than in the rest of the world and is diagnosed three to nine times more often in females than in males the prevalence of did diagnoses increased greatly in the latter half of the 20 th century along with the number of identities often referred to as alters claimed by patients increasing from an average of two or three to approximately 16 did is also controversial within the legal system where it has been used as a rarely successful form of the insanity defense the 1990 s showed a parallel increase in the number of court cases involving the diagnosis dissociative disorders including did have been attributed to disruptions in memory caused by trauma and other forms of stress but research on this hypothesis has been characterized by poor methodology so far scientific studies usually focusing on memory have been few and the results have been inconclusive an alternative hypothesis for the cause of did is as a by product of techniques employed by some therapists especially those using hypnosis and disagreement between the two positions is characterized by intense debate did became a popular diagnosis in the 1970 s 80 s and 90 s but it is unclear if the actual rate of the disorder increased if it was more recognized by health care providers or if sociocultural factors caused an increase in therapy induced iatrogenic presentations the unusual number of diagnoses after 1980 clustered around a small number of clinicians and the suggestibility characteristic of those with did support the hypothesis that did is therapist induced the unusual clustering of diagnoses has also been explained as due to a lack of awareness and training among clinicians to recognize cases of did
distal 18 q is a genetic condition caused by a deletion of genetic material within one of the two copies of chromosome 18 the deletion involves the distal section of 18 q and typically extends to the tip of the long arm of chromosome 18
distal trisomy 10 is a rare chromosomal disorder that causes slow postnatal growth and severe intellectual disability humans like all sexually reproducing species have somatic cells that are in diploid 2 n state meaning that n represent the number of chromosomes and 2 the number of their copies in humans there are 23 chromosomes but there are two sets of them one from mother and one from father totaling in 46 that are arranged according to their size function and genes they carry each cell is supposed to have two of each but sometimes due to mutations or malfunctions during cell division mistakes are made that cause serious health problems one such error is the cause of distal trisomy 10 q disorder each chromosome has two arms labeled p for petite or short and q for long if both arms are equal in length the chromosome is said to be metacentric if arms lengths are unequal chromosome is said to be submetacentric and if p arm is so short that is hard to observe but still present then the chromosome is acrocentric in distal trisomy 10 q disorder end or distal portion of the q long arm of the chromosome number 10 appears to be present three times rather than two times as it is supposed to be this extra arm results in chromosome 10 trisomy meaning that three arms are present depending on the length of the aberrant arm the severity can vary from case to case often the source of this chromosomal error is a translocation in one of the parents sometimes it occurs spontaneously in which case it is termed de novo this syndrome has a large range of outcomes depending on how much chromosomal material is involved outcomes include very slow postnatal growth hypotonia lack of coordination skills and mild to severe cases of intellectual disability digestive issues and heart and kidney problems individuals with this disorder can also be distinguished by their facial features number of support groups do exist in the united states where affected families can meet and discuss problems they encounter possible treatments and can find emotional support
distal intestinal obstruction syndrome dios involves obstruction of the distal part of the small intestines by thickened intestinal content and occurs in about 20 of mainly adult individuals with cystic fibrosis dios was previously known as meconium ileus equivalent a name which highlights its similarity to the intestinal obstruction seen in newborn infants with cystic fibrosis dios tends to occur in older individuals with pancreatic insufficiency individuals with dios may be predisposed to constipation
distal muscular dystrophy or distal myopathy is a group of disorders characterized by onset in the hands or feet many types involve dysferlin but it has been suggested that not all cases do types include dysf is also associated with limb girdle muscular dystrophy type 2 b distal muscular dystrophy is a type of muscular dystrophy that affects the muscles of the extremities the hands feet lower arms or lower legs the cause of this dystrophy is very hard to determine because it can be a mutation in any of at least eight genes and not all are known yet these mutations can be inherited from one parent autosomal dominant or from both parents autosomal recessive along with being able to inherit the mutated gene distal muscular dystrophy has slow progress therefore the patient may not know that they have it until they are in their late 40 ’ s or 50 ’ s there are eight known types of distal muscular dystrophy they are welander ’ s distal myopathy finnish tibial distal myopathy miyoshi distal myopathy nonaka distal myopathy gowers laing distal myopathy hereditary inclusion body myositis type 1 distal myopathy with vocal cord and pharyngeal weakness and zasp related myopathy all of these affect different regions of the extremities and can show up as early as 5 years of age to as late as 50 years old doctors are still trying to determine what causes these mutations along with effective treatments
a distal radius fracture is a common bone fracture of the radius in the forearm because of its proximity to the wrist joint this injury is often called a wrist fracture treatment is usually with immobilization although surgery is sometimes needed for complex fractures specific types of distal radius fractures are colles fracture smith s fracture barton s fracture chauffeur s fracture so called because the crank used to start old cars often kicked back and broke the chauffeurs wrists with a particular pattern most of these names are applied to specific patterns of distal radius fracture but confusion exists because colles fracture is used for example by the us national library of medicine as a generic term for distal radius fracture
distal renal tubular acidosis drta or type 1 renal tubular acidosis rta is the classical form of rta being the first described distal rta is characterized by a failure of acid secretion by the alpha intercalated cells of the cortical collecting duct of the distal nephron this failure of acid secretion may be due to a number of causes and it leads to an inability to acidify the urine to a ph of less than 5 3
distal spinal muscular atrophy type 1 dsma 1 also known as spinal muscular atrophy with respiratory distress type 1 smard 1 distal hereditary motor neuronopathy type 6 dhmn 6 and severe infantile axonal neuronopathy with respiratory failure sianrf — is a rare neuromuscular disorder involving death of motor neurons in the spinal cord which leads to a generalized progressive atrophy of body muscles the condition is caused by a genetic mutation in the ighmbp 2 gene and is inherited in an autosomal recessive manner there is no known cure to dsma 1 and research of the disorder is still in early stages due to low incidence and high mortality rates
distal spinal muscular atrophy type 2 dsma 2 also known as jerash type distal hereditary motor neuropathy hmn j — is a very rare childhood onset genetic disorder characterised by progressive muscle wasting affecting lower and subsequently upper limbs the disorder has been described in arab inhabitants of jerash region in jordan as well as in a chinese family the condition is linked to a genetic mutation in the sigmar 1 gene on chromosome 19 locus 19 p 13 3 and is likely inherited in an autosomal recessive manner
distal subungual onychomycosis is an infection of the nail plate by fungus primarily involving the distal nail plate
a distichia is an eyelash that arises from an abnormal spot on the eyelid this abnormality attributed to a genetic mutation is known to affect dogs and humans distichiae the abnormal eyelash usually exit from the duct of the meibomian gland at the eyelid margin they are usually multiple and sometimes more than one arises from a duct they can affect either the upper or lower eyelid and are usually bilateral the lower eyelids of dogs usually have no eyelashes distichiae usually cause no symptoms because the lashes are soft but they can irritate the eye and cause tearing squinting inflammation and corneal ulcers and scarring treatment options include manual removal electrolysis electrocautery cryotherapy and surgery
distorted vision is a symptom with several different possible causes
distortion is the alteration of the original shape or other characteristic of something such as an object image sound or waveform distortion is usually unwanted and so engineers strive to eliminate distortion or minimize it in some situations however distortion may be desirable the important signal processing operation of heterodyning is based on nonlinear mixing of signals to cause intermodulation distortion is also used as a musical effect particularly with electric guitars the addition of noise or other outside signals hum interference is not deemed distortion though the effects of quantization distortion are sometimes deemed noise a quality measure that explicitly reflects both the noise and the distortion is the signal to noise and distortion sinad ratio
in telecommunication distortion limited operation is the condition prevailing when distortion of a received signal rather than its attenuated amplitude or power limits performance under stated operational conditions and limits note distortion limited operation is reached when the system distorts the shape of the waveform beyond specified limits for linear systems distortion limited operation is equivalent to bandwidth limited operation
distributed artificial intelligence dai is a subfield of artificial intelligence research dedicated to the development of distributed solutions for complex problems regarded as requiring intelligence dai is closely related to and a predecessor of the field of multi agent systems
in software engineering a distributed design pattern is a design pattern focused on distributed computing problems
distributed source coding dsc is an important problem in information theory and communication dsc problems regard the compression of multiple correlated information sources that do not communicate with each other by modeling the correlation between multiple sources at the decoder side together with channel codes dsc is able to shift the computational complexity from encoder side to decoder side therefore provide appropriate frameworks for applications with complexity constrained sender such as sensor networks and video multimedia compression see distributed video coding one of the main properties of distributed source coding is that the computational burden in encoders is shifted to the joint decoder
distributive shock is a medical condition in which abnormal distribution of blood flow in the smallest blood vessels results in inadequate supply of blood to the body s tissues and organs it is one of four categories of shock a condition where there is not enough oxygen carrying blood to meet the metabolic needs of the cells which make up the body s tissues and organs distributive shock is different from the other three categories of shock in that it occurs even though the output of the heart is at or above a normal level the most common cause is sepsis leading to type of distributive shock called septic shock a condition that can be fatal
the distributive tendency is the propensity of the united states congress to lean towards distributive politics especially to gain political support and credit claim through the distributive tendency congress ’ bills evolve over the drafting process to become more broad and reaching with their benefits legislation that follows the distributive tendency has benefits that flow to many districts and can come in many forms though in current day they are often monetary the distributive tendency is a form of distributive politics a political science term that describes the spreading of benefits across different areas interests and constituencies in one piece of legislation the term was “ first coined for nineteenth century land policies but easily extended to include most contemporary public land and resource policies rivers and harbors programs defense procurement and r d labor business and agricultural ‘ clientele ’ services and the traditional tariff in fact during the nineteenth century a majority of policies devised by the federal government were distributive to be considered distributive a piece of legislation should be disaggregable universal and omnibus distributive politics is in contrast to regulatory and redistributive programs the distributive tendency is related to distributive politics distributive benefits distributive policy and distributive legislation and is closely linked with logrolling and pork barrel legislation
district of columbia home rule is the ability of residents of the district of columbia to govern their local affairs as the federal capital the constitution grants the united states congress exclusive jurisdiction over the district in all cases whatsoever at certain times and presently since 1973 congress has allowed certain powers of government to be carried out by locally elected officials however congress maintains the power to overturn local laws and exercises greater oversight of the city than exists for any u s state furthermore the district s elected government exists at the pleasure of congress and could theoretically be revoked at any time a separate yet related controversy is the district s lack of voting representation in congress the city s unique status creates a situation where d c residents do not have full control over their local government nor do they have voting representation in the body that has full control
the dsm v classifies enuresis as an elimination disorder and as such it may be defined as the involuntary or voluntary elimination of urine into inappropriate places a patient must be of at least a developmental level equivalent to the chronological age of a 5 year old in order to be diagnosed with enuresis in other words it is not abnormal for a child below the age of 5 the patient must either experience a frequency of inappropriate voiding at least twice a week for a period of at least 3 consecutive months or experience clinically significant distress or impairment in social occupational or other important areas of functioning in order to be diagnosed with enuresis these symptoms must not be due to any underlying medical condition e g a child who wets the bed because their kidneys produce too much urine is not suffering from enuresis they re suffering from kidney disease which is causing the inappropriate urination as well these symptoms must not be due exclusively to the direct physiological effect of a substance such as a diuretic or antipsychotic
in statistics and information geometry divergence or a contrast function is a function which establishes the distance of one probability distribution to the other on a statistical manifold the divergence is a weaker notion than that of the distance in particular the divergence need not be symmetric that is in general the divergence from p to q is not equal to the divergence from q to p and need not satisfy the triangle inequality
divergent evolution is the accumulation of differences between groups which can lead to the formation of new species usually a result of diffusion of the same species to different and isolated environments which blocks the gene flow among the distinct populations allowing differentiated fixation of characteristics through genetic drift and natural selection primarily diffusion the basis of molecular division can be seen in some higher level characters of structure and function that are readily observable in organisms for example the vertebrate limb is one example of divergent evolution the limb in many different species has a common origin but has diverged somewhat in overall structure and function alternatively divergent evolution can be applied to molecular biology characteristics this could apply to a pathway in two or more organisms or cell types for example this can apply to genes and proteins such as nucleotide sequences or protein sequences that derive from two or more homologous genes both orthologous genes resulting from a speciation event and paralogous genes resulting from gene duplication within a population can be said to display divergent evolution because of the latter it is possible for divergent evolution to occur between two genes within a species in the case of divergent evolution similarity is due to the common origin such as divergence from a common ancestral structure or function has not yet completely obscured the underlying similarity in contrast convergent evolution arises when there are some sort of ecological or physical drivers toward a similar solution even though the structure or function has arisen independently such as different characters converging on a common similar solution from different points of origin this includes analogous structures
diversion colitis is an inflammation of the colon which can occur as a complication of ileostomy or colostomy often occurring within the year following the surgery it also occurs frequently in a neovagina created by colovaginoplasty with varying delay after the original procedure despite the presence of a variable degree of inflammation the most suggestive histological feature remains the prominent lymphoid aggregates a foul smelling mucous rectal discharge may develop from the inflamed mucosa of the distal unused colon the diagnosis cannot be safely reached without knowing the clinical story in many milder cases after ileostomy or colostomy diversion colitis is left untreated and disappears naturally if treatment is required possible treatments include short chain fatty acid irrigation steroid enemas and mesalazine
according to surveys and studies done in the 2000 s there is a lack of diversity in librarianship librarianship is the management organisasion collecting and preserving of information often in libraries the 2003 us census showed that hispanic people had the lowest proportion of librarians in their population while american indians had the lowest number of librarians most librarian jobs were occupied by elderly caucasian males library associations affected by this lack of ethnic diversity have put several measures in place to attempt to correct this issue it has been suggested that the lack of diversity in librarianship is because most people are not aware of the job opportunities in the librarianship sector others suggest that a lack of diversity in university graduates makes it harder for there to be diversity in librarianship as the job is often held by people who hold university degrees
diversity of tactics is a phenomenon wherein a social movement makes periodic use of force for disruptive or defensive purposes stepping beyond the limits of nonviolence but also stopping short of total militarization it also refers to the theory which asserts this to be the most effective strategy of civil disobedience for social change diversity of tactics may promote nonviolent tactics or armed resistance or a range of methods in between depending on the level of repression the political movement is facing it sometimes claims to advocate for forms of resistance that maximize respect for life
diverticulitis is a digestive disease in which pouches within the large bowel wall become inflamed symptoms typically include lower abdominal pain of a sudden onset onset however may also occur over a few days in north america and europe pain is usually on the left side while in asia it is often on the right there may also be fever nausea diarrhoea or constipation or blood in the stool repeated attacks may occur the cause is uncertain risk factors may include obesity lack of exercise smoking a family history of the disease and nonsteroidal anti inflammatory drugs nsaid the role of dietary fiber is unclear having pouches in the large intestine that are not inflamed is known as diverticulosis inflammation occurs in between 10 and 25 at some point in time and is due to a bacterial infection diagnosis may be made by blood tests ct scan colonoscopy or lower gastrointestinal series the differential diagnosis includes irritable bowel syndrome while avoiding nuts and seeds has historically been recommended an association between eating these foods and diverticulitis has not been found and therefore avoiding these foods is no longer recommended mesalazine and rifaximin appear useful for preventing attacks in those with diverticulosis for mild diverticulitis antibiotics by mouth and a liquid diet is recommended for severe cases intravenous antibiotics hospital admission and complete bowel rest may be recommended probiotics are of unclear use complications such as abscess formation fistula formation and perforation of the colon may require surgery the disease is common in the western world and uncommon in africa and asia in the western world about 35 of people have diverticulosis while it affects less than 1 of those in rural africa the disease becomes more frequent with age being particularly common in those over the age of 50 it has also becoming more common in all parts of the world in 2003 in europe it resulted in about 13 000 deaths costs associated with diverticular disease are around 2 4 billion a year in the united states as of 2013
diverticulosis is the condition of having diverticula in the colon that are not inflamed these are outpockets of the colonic mucosa and submucosa through weaknesses of muscle layers in the colon wall they typically cause no symptoms diverticular disease occurs when diverticula become inflamed known as diverticulitis or bleed they typically occur in the sigmoid colon which is a common place for increased pressure the left side is more commonly affected in the united states while the right side is more commonly affected in asia diagnosis is often during routine colonoscopy or as an incidental finding during ct scan it is common in western countries with about half of those over the age of 60 in canada and the united states affected this is uncommon before the age of 40 and increases in incidence after that age rates are lower in africa which has been attributed to a shorter life expectancy and poor healthcare access the lower rate has also been attributed to high fiber
a diverticulum plural diverticula is the medical or biological term for an outpouching of a hollow or a fluid filled structure in the body depending upon which layers of the structure are involved they are described as being either true or false in medicine the term usually implies the structure is not normally present however in the embryonic stage some normal structures begin development as a diverticulum arising from another structure
diving disorders or diving related medical conditions are conditions associated with underwater diving and include both conditions unique to underwater diving and those that also occur during other activities this second group further divides into conditions caused by exposure to ambient pressures significantly different from surface atmospheric pressure and a range of conditions caused by general environment and equipment associated with diving activities
diving medicine also called undersea and hyperbaric medicine uhb is the diagnosis treatment and prevention of conditions caused by humans entering the undersea environment it includes the effects on the body of pressure on gases the diagnosis and treatment of conditions caused by marine hazards and how relationships of a diver s fitness to dive affect a diver s safety hyperbaric medicine is a corollary field associated with diving since recompression in a hyperbaric chamber is used as a treatment for two of the most significant diving related illnesses decompression sickness and arterial gas embolism diving medicine deals with medical research on issues of diving the prevention of diving disorders treatment of diving accidents and diving fitness the field includes the effect of breathing gases and their contaminants under high pressure on the human body and the relationship between the state of physical and psychological health of the diver and safety in diving accidents it is common for multiple disorders to occur together and interact with each other both causatively and as complications diving medicine is a branch of occupational medicine and sports medicine and an important part of diver education
in christian theology divinization deification making divine or theosis is the transforming effect of divine grace the spirit of god or the atonement of christ it literally means to become more divine more like god or take upon a divine nature
a division 7 a dividend in the australian tax system is an amount treated by the australian tax office ato as an assessable dividend of a shareholder of a private company that attempts to make a tax free distributions of profits to the shareholder or an associate of the shareholder division 7 a applies to payments loans and debts forgiven on or after 4 december 1997 however it may also apply to loans in place before this date where the amount of the loan is increased or its term extended on or after 4 december 1997 division 7 a applies to debts forgiven on or after 4 december 1997 regardless of when the debt was created
the division of labour is the separation of tasks in any economic system so that participants may specialize individuals organizations and nations are endowed with or acquire specialized capabilities and either form combinations or trade to take advantage of the capabilities of others in addition to their own specialized capabilities may include equipment or natural resources in addition to skills and training and complex combinations of such assets are often important as when multiple items of specialized equipment and skilled operators are used to produce a single product the division of labour is the motive for trade and the source of economic interdependence because of the large amount of labour saved by giving workers specialized tasks in industrial revolution era factories some classical economists as well as some mechanical engineers such as charles babbage were proponents of division of labour also having workers perform single or limited tasks eliminated the long training period required to train craftsmen who were replaced with lesser paid but more productive unskilled workers historically an increasing division of labour is associated with the growth of total output and trade the rise of capitalism and the increasing complexity of industrialised processes the concept and implementation of division of labour has been observed in ancient sumerian mesopotamian culture where assignment of jobs in some cities coincided with an increase in trade and economic interdependence division of labour generally also increases both producer and individual worker productivity in contrast to division of labour division of work refers to the division of a large task contract or project into smaller tasks — each with a separate schedule within the overall project schedule division of labour instead refers to the allocation of tasks to individuals or organizations according to the skills and or equipment those people or organizations possess often division of labour and division of work are both part of the economic activity within an industrial nation or organization
in mathematics and specifically in number theory a divisor function is an arithmetic function related to the divisors of an integer when referred to as the divisor function it counts the number of divisors of an integer it appears in a number of remarkable identities including relationships on the riemann zeta function and the eisenstein series of modular forms divisor functions were studied by ramanujan who gave a number of important congruences and identities these are treated separately in the article ramanujan s sum a related function is the divisor summatory function which as the name implies is a sum over the divisor function
divya drishti hindi दिव्य दृष्टि or the divine eye sight also known as yoga drishti refers to divine perception which is intuitive perception or cognition that carries with it an intrinsic certainty and conviction it is a spiritual attainment which according to patanjali enables the yogi to communicate with heavenly bodies this divine vision is gained by the practice of neti that balances the flow of prana shakti in ida pingala and sushmana and uplifts the higher mental faculties which awaken the chakras and kundalini and even enables the yogi to see into the past and future uttitha padma āsana the raised lotus posture makes one develop divya drishti opens the heart center and cures respiratory disorders in the bhagavad gita krishna tells arjuna न तु मां शक्यसे द्रष्टुमनेनैव स्वचक्षुषा दिव्यं ददामि ते चक्षुः पश्य मे योगमैश्वरम् but surely you cannot see me with these human eyes of yours therefore i vouchsafe to you the divine eye with this you behold my divine power of yoga bhagavad gita xi 8 krishna invited arjuna to observe the cosmic body or viraj and behold as concentrated within that body in the person of krishna the entire creation and all that is desired to be seen when arjuna failed to see that divine form krishna bestowed the gift of divine vision – दिव्यं चक्षुः thus endowed arjuna saw an undisguised reality he could otherwise not see what he then saw was अद्भुतदर्शनम् many a wonderful sight divine in essence transcendent and all effulgent the sight which has never been seen before arjuna saw the power of creating diversity in the universe a similar gift had been bestowed on sanjaya by sage vyasa the vedic seers have spoken about the wondrous eyes of lord vishnu the ever open watchful divine eyes whose power of sight is not restricted by space and time rishi medhātithih kānvah states that तद्विष्णोः परमं पदं सदा पश्यन्ति सूरयः दिवीव चक्षुराततम् rig veda i xxii 20 the learned practitioners of dharma do in the brightness of the all revealing sun clearly see the wide spread eyes of the lord the mighty all surveying sole witness and in the process with the aid of knowledge also see him at all times ensconced as the atman
dizziness is an impairment in spatial perception and stability because the term dizziness is imprecise it can refer to vertigo presyncope disequilibrium or a non specific feeling such as giddiness or foolishness one can induce dizziness by engaging in disorientating activities such as spinning vertigo is the sensation of spinning or having one s surroundings spin about them many people find vertigo very disturbing and often report associated nausea and vomiting it represents about 25 of cases of occurrences of dizziness disequilibrium is the sensation of being off balance and is most often characterized by frequent falls in a specific direction this condition is not often associated with nausea or vomiting presyncope is lightheadedness muscular weakness and feeling faint as opposed to a syncope which is actually fainting non specific dizziness is often psychiatric in origin it is a diagnosis of exclusion and can sometimes be brought about by hyperventilation a stroke is the cause of isolated dizziness in 0 7 of people who present to the emergency room
in a loading dock one problem to overcome is the problem of bridging the gap between a truck and the dock or warehouse floor not all trucks are the same height and the height of the trailer floor within a truck can vary according to how heavily the truck is laden thus there is not only a gap to bridge but a height difference to overcome various devices are employed in order to achieve this dock plates dock levellers dock boards and various forms of lift these devices vary in construction suitability to dock conditions cost of installation and loading capacity dock levellers and lifts are generally permanent fixtures at each door of a dock dock plates and dock boards are generally by contrast portable and not fixed either to dock or truck dock plates and dock boards are simply metal ramps bridging the gaps between dock and truck dock plates are generally made out of aluminium whilst dock boards are generally made out of steel aluminium dock plates are thus more suitable for lighter loads such as handcarts and dollies whereas steel dock boards are more suitable for heavier motorized equipment such as fork lift trucks and electric pallet trucks another difference between dock plates and dock boards in addition to their load bearing capabilities is their construction dock plates are simple flat plates whereas dock boards have curbs bolted or welded to the edge of the board run off is prevented by a simple painted yellow strip along the edge of a dock plate whereas it is the curbs also generally painted yellow that prevent run off on dock boards these curbs are also where the higher weight capacities of dock boards come from run off is thus a significant risk on dock plates since the yellow strip is not a particularly effective mechanism for preventing it both dock plates and dock boards have a diamond pattern embossed onto their upper surfaces to prevent wheel slip as carts and vehicles travel up and down the incline similarly they both have locking t bar legs that extend down into the gap between truck and dock to secure them they are both portable but dock boards are heavier than dock plates the latter may be carried by hand and are generally fitted with handles for doing so the former usually require a fork lift in order to place and remove them and are generally fitted with either loops or chains used for attaching the dock board to the forks of the fork lift dock levellers are as mentioned fixed to the dock they comprise a simple metal plate called a lip that is raised from a stowed position and then lowered onto the back of the truck lip can be hinged or telescopic type they are operated either manually via a simple pull chain or hydraulically most common with an electric pump driving a piston to lift the plate and another one to move the lip dock levellers are more expensive devices than the comparatively light weight dock plates and dock boards the most common form of dock leveller is the recessed or pit dock leveller as the name suggests this type of leveller is contained in a recess or pit beneath the dock door and floor surface dock levelers are stronger than dock plates and have similar ranges to dock boards making them suitable not only for motorized fork lift trucks but also for master conveyors for which neither dock plates or dock boards are suitable safety also is very high for this kind of product safety rules as en 1398 european standard specifies the safety requirements for design construction installation maintenance and testing of dock levellers and for safety components on dock levellers note edge of dock levelers have fixed positions which have restricted ranges making them unsuitable for nonstandard dock heights because they carry heavy motorized equipment the grade of the incline has to be shallow the greater the height differential between truck and dock that a dock leveller can compensate for the longer the leveller itself has to be moreover the grade of the incline must not be so great that the vehicles cannot climb it a height differential of between 7 and 8 inches generally requires a 6 foot long 1 8 m leveller for an electric palette carrier a height differential of between 17 and 18 inches generally requires a 12 foot long 3 7 m leveller for a petrol engined fork lift truck anyway the lip has to be considered in the length of the leveller as it is part of it a telescopic lip 20 or 40 inches can help to reduce the length of the leveller to 10 feet dock levellers and indeed dock plates and dock boards are used where a building has a truck level door i e a door with a floor level roughly at the same height as the floor of the truck s trailer some buildings only have drive in doors i e doors at the same level as the ground outside of the building suitable for driving directly into the building for loading docks with drive in doors and also albeit rarely for loading docks with truck level doors a lift is sometimes employed other less common devices employed when bridging the gap between truck and dock are truck levellers these are hydraulic lifts positioned beneath the rear wheels of the truck that are used to raise and lower the truck so that it is level with the loading dock edge the problems with truck levellers that make them rarely employed are twofold first they cause the truck interior to be at an incline which causes loading and unloading difficulties second they are expensive to maintain since they require being below ground level and open to the air proper drainage and protection against the weather recessed dock levellers also have problems of exposure to the weather however because they are recessed into the dock which is above ground level they do not have as great a problem with drainage equally because they are recessed into the dock they extend partially back from the dock edge a dock leveller can be installed so that it extends inside the loading dock door and thus inside the building protecting it from the weather
document classification or document categorization is a problem in library science information science and computer science the task is to assign a document to one or more classes or categories this may be done manually or intellectually or algorithmically the intellectual classification of documents has mostly been the province of library science while the algorithmic classification of documents is mainly in information science and computer science the problems are overlapping however and there is therefore interdisciplinary research on document classification the documents to be classified may be texts images music etc each kind of document possesses its special classification problems when not otherwise specified text classification is implied documents may be classified according to their subjects or according to other attributes such as document type author printing year etc in the rest of this article only subject classification is considered there are two main philosophies of subject classification of documents the content based approach and the request based approach
the doebner reaction is the chemical reaction of an aniline with an aldehyde and pyruvic acid to form quinoline 4 carboxylic acids the doebner reaction
the doebner – miller reaction is the organic reaction of an aniline with α β unsaturated carbonyl compounds to form quinolines scheme 1 the doebner miller reaction this reaction is also known as the skraup doebner von miller quinoline synthesis and is named after the czech chemist zdenko hans skraup 1850 – 1910 and the germans oscar döbner doebner 1850 – 1907 and wilhelm von miller 1848 – 1899 when the α β unsaturated carbonyl compound is prepared in situ from two carbonyl compounds via an aldol condensation the reaction is known as the beyer method for quinolines the reaction is catalyzed by lewis acids such as tin tetrachloride and scandium iii triflate and brønsted acids such as p toluenesulfonic acid perchloric acid amberlite and iodine
doege – potter syndrome dps is a paraneoplastic syndrome in which hypoglycemia is associated with solitary fibrous tumors the hypoglycemia is the result of the tumors producing insulin like growth factor 2 the syndrome was first described in 1930 by karl walter doege 1867 – 1932 a german american physician and by roy pilling potter 1879 – 1968 an american radiologist working independently the full term doege – potter syndrome was infrequently used until the publication of a 2000 article using the eponym dps is rare as of 1976 less than one hundred cases were described with a malignancy rate of 12 – 15 actual rates of hypoglycemia associated with a fibrous tumor are quite rare a 1981 study of 360 solitary fibrous tumors of the lungs found that only 4 caused hypoglycemia and are linked to large tumours with high rates of mitosis removal of the tumor will normally resolve the symptoms tumors causing dps tend to be quite large in one case a 3 kg 6 6 lb 23 × 21 × 12 cm 9 1 × 8 3 × 4 7 in mass was removed sufficiently large to cause a collapsed lung in x rays they appear as a single mass with visible defined borders appearing at the edges of the lungs or a fissure dividing the lobes of the lungs similar hypoglycemic effects have been related to mesenchymal tumors
in organic chemistry the doering – laflamme allene synthesis is a reaction of alkenes that converts them to allenes by insertion of a carbon atom this name reaction is named for william von eggers doering and a co worker who first reported it the reaction is a two stage process in which first the alkene is reacted with dichlorocarbene or dibromocarbene to form a dihalocyclopropane this intermediate is then reacted with a reducing metal such as sodium or magnesium or with an organolithium reagent either approach converts the dihalogenated carbon to a carbene or carbenoid like structure the resulting cyclopropylcarbene rearranges to form the allene product the electronic nature of the carbene intermediate is not entirely understood several different mechanisms for its electrocyclic rearrangement have been studied
a dog leg gearbox is a manual transmission shift pattern distinguished by an up over up shift between first and second gear the layout derives its name from a dog s hind leg with its sharp angles dog leg gearboxes have fallen out of fashion primarily because most manual performance cars now have six speed gearboxes which are unsuited to the dog leg layout
dog bites or dog attacks are attacks on humans by feral or domestic dogs with the close association of dogs and humans in daily life largely as pets dog bites – with injuries from very minor to significant – are extremely common dogs also pose danger from their claws and can be powerful enough to knock people down there is considerable debate on whether or not certain breeds of dogs are inherently more prone to commit attacks causing serious injury i e so driven by instinct and breeding that under certain circumstances they are exceedingly likely to attempt or commit dangerous attacks regardless of the breed of the dog it is recognized that the risk of dangerous dog attacks can be greatly increased by human actions such as neglect or fight training or inactions as carelessness in confinement and control significant dog bites affect tens of millions of people globally each year it is estimated that two percent of the us population from 4 5 – 4 7 million people are bitten by dogs each year most bites occur in children in the 1980 s and 1990 s the us averaged 17 fatalities per year while in the 2000 s this has increased to 26 77 of dog bites are from the pet of family or friends and 50 of attacks occur on the dog owner s property animal bites most of which are from dogs are the reason for 1 of visits to an emergency department in the united states attacks on the serious end of the spectrum have become the focus of increasing media and public attention in the late 20 th and early 21 st centuries
dog pox is an infection of canines which may be caused by the canine herpes virus and can result in symptoms ranging from no symptoms to inflammation of the respiratory or digestive tract to skin inflammation and lesions over 60 of adult male dogs exhibit lesions as a result of this infection because of the variance in the symptoms it is often mistaken for allergies however the infection can be severe in puppies even causing death
dogger bank itch is a cutaneous condition characterized by a long lasting dermatitis caused by exposure to the sea chervil alcyonidium diaphanum a bryozoan the disease common in fishermen who work in the north sea has been recognized by the danish workman s compensation act since 1939
dolichocephaly derived from the ancient greek δολιχός meaning long is a condition where the head is longer than would be expected relative to its width the skulls of neanderthals show a marked dolichocephaly compared to other humans past or present in humans scaphocephaly is a form of dolichocephaly dolicocephalic dog breeds such as german shepherd dogs have an elongated nose this makes them vulnerable to fungal diseases of the nose such as aspergillosis in human the anierior posterior diameter length of dolichocephaly head is more than transverse diameter width it has an incidence of 1 in every 4200 babies it can present be in cases of sensenbrenner syndrome crouzon syndrome sotos syndrome as well as marfan syndrome although dolichocephaly may be associated with some other abnormalities alone it is just a normal variation unless symptomatic it is nothing to worry about early diagnosis can be made by x ray or ultrasonography treatment is not essential
in medicine a dolichocolon word derived from ancient greek dolichos the long distance in running and colon is an abnormally long large intestine it should not be confused with an abnormally wide large intestine which is called a megacolon dolichocolon may predispose to abnormal rotation see volvulus and interposition between the diaphragm and the liver see chilaiditi syndrome it is more commonly seen in the elderly some psychiatric patients or in institutionalised individuals it is not however a part of normal aging the exact cause remains unknown dolichocolon is often an incidental finding on abdominal x rays or colonoscopy it is not by itself a disease and as such requires no treatment
dolichol kinase deficiency is a cutaneous condition caused by a mutation in the dolichol kinase gene it is also known as congenital disorder of glycosylation 1 m
dolichostenomelia is a human condition or habitus in which the limbs are unusually long the name is derived from ancient greek dolichos long steno short narrow close melia of the limbs it is a common feature of several kinds of hereditary disorders which affect connective tissue such as marfan syndrome and homocystinuria
the dolly zoom is an in camera effect that appears to undermine normal visual perception the effect is achieved by zooming a zoom lens to adjust the angle of view often referred to as field of view or fov while the camera dollies moves toward or away from the subject in such a way as to keep the subject the same size in the frame throughout in its classic form the camera angle is pulled away from a subject while the lens zooms in or vice versa thus during the zoom there is a continuous perspective distortion the most directly noticeable feature being that the background appears to change size relative to the subject the visual appearance for the viewer is that either the background suddenly grows in size and detail and overwhelms the foreground or the foreground becomes immense and dominates its previous setting depending on which way the dolly zoom is executed as the human visual system uses both size and perspective cues to judge the relative sizes of objects seeing a perspective change without a size change is a highly unsettling effect often with strong emotional impact the effect was first conceived by romanian cinematographer sergiu huzum but was first used by irmin roberts a paramount second unit cameraman in alfred hitchcock s film vertigo in addition to vertigo the shot has been used in many films including goodfellas road to perdition jaws body double the island of dr moreau josie and the pussycats and mike and dave need wedding dates
domain inventory is a design pattern applied within the service orientation design paradigm whose application enables creating pools of services which correspond to different segments of the enterprise instead of creating a single enterprise wide pool of services this design pattern is usually applied when it is not possible to create a single inventory of services for whole of the enterprise by following the same design standards across the different segments of the enterprise the domain inventory design pattern by thomas erl asks how can services be delivered to maximize recomposition when enterprise wide standardization is not possible and is discussed as part of this podcast
domestic energy consumption or domestic consumption of energy is the total amount of energy used in a house for household work the amount of energy used per household varies widely depending on the standard of living of the country the climate and the age and type of residence in the united states as of 2008 in an average household in a temperate climate the yearly use of household energy can be composed as follows this equates to an average instantaneous power consumption of 2 kw at any given time households in different parts of the world will have differing levels of consumption based on latitude and technology
domestic violence also named domestic abuse battering or family violence is a pattern of behavior which involves violence or other abuse by one person against another in a domestic setting such as in marriage or cohabitation intimate partner violence is violence by a spouse or partner in an intimate relationship against the other spouse or partner domestic violence can take place in heterosexual and same sex family relationships and can involve violence against children in the family or in some u s states violence against a roommate domestic violence can take a number of forms including physical verbal emotional economic religious and sexual abuse which can range from subtle coercive forms to marital rape and to violent physical abuse such as female genital mutilation and acid throwing that results in disfigurement or death domestic murders include stoning bride burning honor killings and dowry deaths globally the victims of domestic violence are overwhelmingly women and women tend to experience more severe forms of violence however it has been shown in the united states that women are the primary perpetrators in non reciprocal cases in some countries domestic violence is often seen as justified particularly in cases of actual or suspected infidelity on the part of the woman and is legally permitted research has also shown there to be a direct and significant correlation between a country s level of gender equality and actual rates of domestic violence domestic violence is among the most underreported crimes worldwide for both men and women men face additional gender related barriers in reporting due to social stigmas regarding male victimization and an increased likelihood of being overlooked by healthcare providers domestic violence occurs when the abuser believes that abuse is acceptable justified or unlikely to be reported it may produce intergenerational cycles of abuse in children and other family members who may feel that such violence is acceptable or condoned very few people recognize themselves as abusers or victims because they may consider their experiences as family disputes that just got out of control awareness perception definition and documentation of domestic violence differs widely from country to country domestic violence often happens in the context of forced or child marriage in abusive relationships there may be a cycle of abuse during which tensions rise and an act of violence is committed followed by a period of reconciliation and calm victims of domestic violence may be trapped in domestic violent situations through isolation power and control cultural acceptance lack of financial resources fear shame or to protect children as a result of abuse victims may experience physical disabilities chronic health problems mental illness limited finances and poor ability to create healthy relationships victims may experience psychological problems such as post traumatic stress disorder children who live in a household with violence often show psychological problems from an early age such as dysregulated aggression which may later contribute to continuing the legacy of abuse when they reach adulthood
domestic violence in argentina is a serious problem since the 1990 s onwards the government of argentina has taken steps to address this problem yet the policies of argentina have been criticized for being weak primarily due to focusing on civil rather than criminal dealing with this form of violence and for stressing conciliation between the victim and perpetrator the policy dealing with domestic violence has also been made more difficult due to the decentralized nature of the country argentina being a decentralized federal state with 23 provinces has led to significant variation between provincial policies on domestic violence with women across the country having differing levels of protection
domestic violence in bolivia is a pervasive and underreported problem according to the center for the information and development of women cidem 70 percent of women suffer some form of abuse cidem noted that their 2006 statistics did not reflect the full magnitude of the problem of violence against women and that a great number of women did not report the aggression they faced on a daily basis the most exhaustive national survey on domestic violence conducted by the national statistical institute in 2003 showed 64 percent of women were the target of some form of emotional physical or sexual abuse from their partner
domestic violence in chile locally referred to as violencia intrafamiliar is a prevalent problem domestic violence describes violence by an intimate partner or other family members regardless of the place the violence occurs
domestic violence in china involves violence or abuse by intimate partners or family members against one another intimate partner violence ipv by the man is the most common type of domestic violence in china a 2005 american journal of public health report found that 1 out of 5 chinese women had experienced physical violence from their partner in the past year although china acknowledged that domestic violence was a problem in the 1930 s it has only become a visible issue in the past few decades due to economic and social changes in the 1980 s domestic violence is legally defined in article 2 of the domestic violence law of 2015 as physical psychological or other infractions between family members effected through the use of methods such as beatings restraints maiming restrictions on physical liberty as well as recurrent verbal abuse or intimidation although the legal definition is confined to family members domestic violence can also occur between unmarried lgbt and other domestic couples
domestic violence in kenya is a problem as in many parts of africa there is a deep cultural belief in kenya that it is socially acceptable to hit a woman to discipline a spouse
domestic violence in lithuania is a pervasive social problem the law on protection against domestic violence came into force in 2011 in the four months after the law took effect lithuanian police received over 10 000 reports of domestic violence and initiated 3 300 investigations
domestic violence in nigeria is a problem as in many parts of africa there is a deep cultural belief in nigeria that it is socially acceptable to hit a woman to discipline a spouse domestic violence is widespread and shows no signs of lessening in nigeria the cleen foundation reports 1 in every 3 respondents admitting to being a victim of domestic violence the survey also found a nationwide increase in domestic violence in the past 3 years from 21 in 2011 to 30 in 2013 a cleen foundation ’ s 2012 national crime and safety survey demonstrated that 31 of the national sample confessed to being victims of domestic violence domestic violence takes many forms including physical sexual emotional and mental traditionally domestic violence is committed against females common forms of violence against women in nigeria are rape acid attacks molestation wife beating and corporal punishment the nigerian government has taken legal proceedings to prosecute men or abuse their women in several states there is currently a push in nigeria for federal laws concerning domestic violence and for a stronger national response and support for domestic violence issues
domestic violence in pakistan is an endemic social problem according to a study carried out in 2009 by human rights watch it is estimated that between 70 and 90 percent of women in pakistan have suffered some form of abuse an estimated 5000 women are killed per year from domestic violence with thousands of others maimed or disabled the majority of victims of violence have no legal recourse law enforcement authorities do not view domestic violence as a crime and usually refuse to register any cases brought to them given the very few women s shelters in the country victims have limited ability to escape from violent situations
domestic violence in panama is a serious problem and remains underreported domestic violence including spousal rape psychological physical and economic abuse are criminalized panama enacted ley no 38 del 2001 against domestic violence in 2013 the country enacted law 82 typifying femicide and violence against women ley 82 tipifica el femicidio y la violencia contra las mujeres a comprehensive law against violence against women the integrated national system for criminal statistics siec reported 1 283 cases of domestic violence from january through june 2013 statistics for january through september from the panamanian observatory against gender based violence showed that of the 47 women who died violently 30 died as a result of domestic violence
domestic violence in peru is a problem abuses are aggravated by insensitivity on the part of law enforcement and judicial authorities toward female victims
domestic violence in saudi arabia is a problem as in many parts of asia there is a deep cultural belief in saudi arabia that it is socially acceptable to hit a woman to discipline a spouse
domestic violence in uganda is a problem as it is in many parts of africa there is a deep cultural belief in uganda that it is socially acceptable to hit a woman to discipline her
domestic violence within lesbian relationships is the pattern of violent and coercive behavior in a female same sex relationship where a lesbian or other non heterosexual woman seeks to control the thoughts beliefs or conduct of her female intimate partner in the case of multiple forms of domestic partner abuse it is also referred to as lesbian battering although domestic violence is widely known as a heterosexual issue it is a significant factor within lesbian relationships as well
doming is a phenomenon found on some crt televisions in which parts of the shadow mask become heated in televisions that exhibit this behavior it tends to occur in high contrast scenes in which there is a largely dark scene with one or more localized bright spots as the electron beam hits the shadow mask in these areas it heats unevenly the shadow mask warps due to the heat differences which causes the electron gun to hit the wrong colored phosphors and incorrect colors to be displayed in the affected area
a domino effect or chain reaction is the cumulative effect produced when one event sets off a chain of similar events the term is best known as a mechanical effect and is used as an analogy to a falling row of dominoes it typically refers to a linked sequence of events where the time between successive events is relatively small it can be used literally an observed series of actual collisions or metaphorically causal linkages within systems such as global finance or politics
donnai – barrow syndrome is a genetic disorder first described by dian donnai and margaret barrow in 1993 it is associated with lrp 2 it is an inherited genetic disorder that affects many parts of the body
donohue syndrome also known as leprechaunism is an extremely rare and severe genetic disorder leprechaunism derives its name from the fact that people with the disease often have elfin features and are smaller than usual affected individuals have an insulin receptor with greatly impaired functionality
donor fatigue is a phenomenon in which people no longer donate to charities although they have in the past on a larger scale it can also refer to a slowness to act on the part of the international community or any other donor base in response to a humanitarian crisis or call to action
dopamine responsive dystonia drd also known as hereditary progressive dystonia with diurnal fluctuation segawa s disease or segawa s dystonia is a genetic movement disorder which usually manifests itself during early childhood at around ages 5 – 8 years variable start age characteristic symptoms are increased muscle tone dystonia such as clubfoot and parkinsonian features typically absent in the morning or after rest but worsening during the day and with exertion children with drd are often misdiagnosed as having cerebral palsy the disorder responds well to treatment with levodopa
dopamine beta hydroxylase deficiency is a condition involving inadequate dopamine beta hydroxylase it is characterized by increased amounts of serum dopamine and the absence of nor epinephrine and epinephrine dopamine is released in place of nor epinephrine as a false neurotransmitter this condition is sometimes referred to as norepinephrine deficiency dopamine beta hydroxylase deficiency belongs to the rare diseases it is a recessive disorder
dopamine dysregulation syndrome dds is a dysfunction of the reward system observed in some individuals taking dopaminergic medications for an extended length of time it can occur in subjects with parkinson s disease pd due to a long exposure to dopamine replacement therapy drt it is characterized by self control problems such as addiction to medication gambling or sexual behavior
the word dord is a notable error in lexicography an accidental creation or ghost word of the g and c merriam company s staff in the second 1934 edition of its new international dictionary in which the term is defined as density philip babcock gove an editor at merriam webster who became editor in chief of webster s third new international dictionary wrote a letter to the journal american speech fifteen years after the error was caught in which he explained why dord was included in that dictionary on july 31 1931 austin m patterson webster s chemistry editor sent in a slip reading d or d cont density this was intended to add density to the existing list of words that the letter d can abbreviate the slip somehow went astray and the phrase d or d was misinterpreted as a single run together word dord this was a plausible mistake because headwords on slips were typed with spaces between the letters making d or d look very much like d o r d a new slip was prepared for the printer and a part of speech assigned along with a pronunciation the would be word got past proofreaders and appeared on page 771 of the dictionary around 1934 on february 28 1939 an editor noticed dord lacked an etymology and investigated soon an order was sent to the printer marked plate change imperative urgent in 1940 bound books began appearing without the ghost word but with a new abbreviation although inspection of printed copies well into the 1940 s show dord still present the non word dord was excised and the definition of the adjacent entry doré furnace was expanded from a furnace for refining dore bullion to a furnace in which dore bullion is refined to close up the space gove wrote that this was probably too bad for why shouldn t dord mean density the entry dord was not removed until 1947
the zeppelin d i or zeppelin lindau d i or zeppelin d i do as named in german documents was also sometimes referred postwar as the dornier d i or dornier zeppelin d i for the designer was a single seat all metal stressed skin monocoque cantilever wing biplane fighter developed by claude dornier while working for luftschiffbau zeppelin at their lindau facility it was too late to see service with the german air force luftstreitkräfte during world war one
the dory rips is a phenomenon involving extreme tidal agitation of waters located in the bay of fundy off the headland of cape d or in nova scotia canada the phenomenon occurs at the entrance to the minas basin which is known for the globe s highest tides the turbulence does not result from a simple rip tide but rather from the collision of three opposed tidal currents whose violence is enhanced by the presence of a subsurface reef that forces the water upward the powerful incoming tidal current loops back and collides with itself while another current coursing in semicircular fashion around advocate bay slams into the collision point at a 90 degree angle
dose dumping is a phenomenon of drug metabolism in which environmental factors can cause the premature and exaggerated release of a drug this can greatly increase the concentration of a drug in the body and thereby produce adverse effects or even drug induced toxicity dose dumping is most commonly seen in drugs taken by mouth and digested in the gastrointestinal tract around the same time patients take their medication they can also ingest other substances like fatty meals or alcohol that increase drug delivery the substances may act on the drug s capsule to speed up drug release or they may stimulate the body s absorptive surfaces to increase the rate of drug uptake dose dumping is a disadvantage found in extended release dosage form in general drug companies try to avoid drugs with significant dose dumping effects such drugs are prone to problems and are often pulled from the market such was the case with the pain medication palladone once daily formulation due to its dose dumping effects when taken with alcohol
dot gain or tonal value increase is a phenomenon in offset lithography and some other forms of printing which causes printed material to look darker than intended it is caused by halftone dots growing in area between the original printing film and the final printed result in practice this means that an image that has not been adjusted to account for dot gain will appear too dark when it is printed dot gain calculations are often an important part of a cmyk color model
in software engineering a double chance function is a software design pattern with a strong application in cross platform and scalable development consider a graphics api with functions to drawpoint drawline and drawsquare it is easy to see that drawline can be implemented solely in terms of drawpoint and drawsquare can in turn be implemented through four calls to drawline if you were porting this api to a new architecture you would have a choice implement three different functions natively taking more time to implement but likely resulting in faster code or write drawpoint natively and implement the others as described above using common cross platform code an important example of this approach is the x 11 graphics system which can be ported to new graphics hardware by providing a very small number of device dependent primitives leaving higher level functions to a hardware independent layer the double chance function is an optimal method of creating such an implementation whereby the first draft of the port can use the fast to market slow to run version with a common drawpoint function while later versions can be modified as slow to market fast to run where the double chance pattern scores high is that the base api includes the self supporting implementation given here as part of the null driver and all other implementations are extensions of this consequently the first port is in fact the first usable implementation one typical implementation in c could be class cbasegfxapi virtual void drawpoint int x int y 0 abstract concept for the null driver virtual void drawline int x 1 int y 1 int x 2 int y 2 drawpoint repeated virtual void drawsquare int x 1 int y 1 int x 2 int y 2 drawline repeated class coriginalgfxapi public cbasegfxapi virtual void drawpoint int x int y the only necessary native calls virtual void drawline int x 1 int y 1 int x 2 int y 2 if this function exists a native drawline routine will be used otherwise the base implementation is run class cnewgfxapi public cbasegfxapi virtual void drawpoint int x int y the only necessary for native calls note that the cbasegfxapi drawpoint function is never used per se as any graphics call goes through one of its derived classes so a call to cnewgfxapi drawsquare would have its first chance to render a square by the cnewgfxapi class if no native implementation exists then the base class is called at which point the virtualization takes over and means that cnewgfxapi drawline is called this gives the cnewgfxapi class a “ second chance ” to use native code if any is available with this method it is theoretically possible to build an entire 3 d engine applying software rasterizing using only one native function in the form of drawpoint with other functions being implemented as and when time permits in practise this would be hopelessly slow but it does demonstrate the possibilities for double chance functions
in software engineering double checked locking also known as double checked locking optimization is a software design pattern used to reduce the overhead of acquiring a lock by first testing the locking criterion the lock hint without actually acquiring the lock only if the locking criterion check indicates that locking is required does the actual locking logic proceed the pattern when implemented in some language hardware combinations can be unsafe at times it can be considered an anti pattern it is typically used to reduce locking overhead when implementing lazy initialization in a multi threaded environment especially as part of the singleton pattern lazy initialization avoids initializing a value until the first time it is accessed
in basketball a double is the accumulation of a double digit number total in one of five statistical categories — points rebounds assists steals and blocked shots — in a game multiple players usually score double digit points in any given basketball game the double nomenclature is usually reserved for when a player has double digit totals in more than one category a double double is the accumulation of a double digit number total in two of the five categories in a game the most common double double combination is points rebounds followed by points assists since the 1983 – 84 season tim duncan leads the national basketball association nba in the points rebounds combination with 840 and john stockton leads the points assists combination with 714 a triple double is the accumulation of a double digit number total in three of the five categories in a game the most common way to achieve a triple double is through points rebounds and assists oscar robertson leads the all time nba list with 181 and is the only player ever to average a triple double for a season lebron james leads the list among active players with 42 a quadruple double is the accumulation of a double digit number total in four of the five categories in a game this has occurred five times in the nba a quintuple double is the accumulation of a double digit number total in all five categories in a game two quintuple doubles have been recorded by high school girls but none have occurred in college or professional games a similar accomplishment is the five by five which is the accumulation of at least five points five rebounds five assists five steals and five blocks in a game in the nba only hakeem olajuwon and andrei kirilenko have accumulated multiple five by fives since the 1984 – 85 season
double aortic arch daa is a relatively rare congenital cardiovascular malformation daa is an anomaly of the aortic arch in which two aortic arches form a complete vascular ring that can compress the trachea and or esophagus most commonly there is a larger dominant right arch behind and a smaller hypoplastic left aortic arch in front of the trachea esophagus the two arches join to form the descending aorta which is usually on the left side but may be right sided or in the midline in some cases the end of the smaller left aortic arch closes left atretic arch and the vascular tissue becomes a fibrous cord although in these cases a complete ring of two patent aortic arches is not present the term ‘ vascular ring ’ is the accepted generic term even in these anomalies the symptoms are related to the compression of the trachea esophagus or both by the complete vascular ring diagnosis can often be suspected or made by chest x ray barium esophagram or echocardiography computed tomography ct or magnetic resonance imaging mri show the relationship of the aortic arches to the trachea and esophagus and also the degree of tracheal narrowing bronchoscopy can be useful in internally assessing the degree of tracheomalacia treatment is surgical and is indicated in all symptomatic patients in the current era the risk of mortality or significant morbidity after surgical division of the lesser arch is low however the preoperative degree of tracheomalacia has an important impact on postoperative recovery in certain patients it may take several months up to 1 – 2 years for the obstructive respiratory symptoms wheezing to disappear
double counting in accounting is an error whereby a transaction is counted more than once for whatever reason but in social accounting it also refers to a conceptual problem in social accounting practice when the attempt is made to estimate the new value added by gross output or the value of total investments
double diffusive convection is a fluid dynamics phenomenon that describes a form of convection driven by two different density gradients which have different rates of diffusion convection in fluids is driven by density variations within them these density variations may be caused by gradients in the composition of the fluid or by differences in temperature through thermal expansion thermal and compositional gradients can often diffuse with time reducing their ability to drive the convection and requiring that gradients in other regions of the flow exist in order for convection to continue a common example of double diffusive convection is in oceanography where heat and salt concentrations exist with different gradients and diffuse at differing rates an effect that affects both of these variables is the input of cold freshwater from an iceberg double diffusive convection is important in understanding the evolution of a number of systems that have multiple causes for density variations these include convection in the earth s oceans as mentioned above in magma chambers and in the sun where heat and helium diffuse at differing rates two quite different types of fluid motion exist — and therefore are classified accordingly — depending on whether the stable stratification is provided by the density affecting component with the lowest or the highest molecular diffusivity if the stratification is provided by the component with the lower molecular diffusivity for example in case of a stable salt stratified ocean perturbed by a thermal gradient due to an iceberg the stratification is called to be of diffusive type see external link below otherwise it is of finger type occurring frequently in oceanographic studies as salt fingers these long fingers of rising and sinking water occur when hot saline water lies over cold fresh water of a higher density a perturbation to the surface of hot salty water results in an element of hot salty water surrounded by cold fresh water this element loses its heat more rapidly than its salinity because the diffusion of heat is faster than of salt this is analogous to the way in which just unstirred coffee goes cold before the sugar has diffused to the top because the water becomes cooler but remains salty it becomes denser than the fluid layer beneath it this makes the perturbation grow and causes the downward extension of a salt finger as this finger grows additional thermal diffusion accelerates this effect
the double feature also known as a double bill was a motion picture industry phenomenon in which theatre managers would exhibit two films for the price of one supplanting an earlier format in which one feature film and various short subject reels would be shown
a double inlet left ventricle dilv or single ventricle is a congenital heart defect appearing in 5 in 100 000 newborns where both the left atrium and the right atrium feed into the left ventricle the right ventricle is hypoplastic or does not exist
double outlet right ventricle dorv is a form of congenital heart disease where both of the great arteries connect in whole or in part to the right ventricle rv in some cases it is found that this occurs on the left side of the heart rather than the right side
a double sunset is a rare astro geographical phenomenon in which the sun sets twice on the same evening from a specific place the phenomenon is traditionally associated with the town of leek in staffordshire from where it is viewed on and around the summer solstice in good weather the occurrence was first recorded in writing in 1686 by dr robert plot in his book the natural history of stafford shire although it has been argued that the first people to witness the spectacle may well have been danish settlers from the great army which invaded england in the ninth century the traditional site for observing the phenomenon was the churchyard of saint edward the confessor from a particular point in which the whole of the sun set on the summit of the cloud a millstone grit hill six miles to the northwest the sun partially reappeared from the cloud s steep northern slope and soon afterwards set for a second and final time on the horizon the spectacle was last reliably witnessed and filmed from the churchyard in 1977 but is no longer visible from the location because of tree interference it is however still observable from leek on and around the summer solstice from the road to pickwood hall off milltown way and from lowe hill on the outskirts of the town better viewing points though are from the a 523 above rudyard reservoir and woodhouse green both of which are nearer to the cloud and therefore enable a larger proportion of the sun to reappear further double sunsets were discovered by the writer jeff kent in 1997 from three places in west derbyshire observed against the limestone reef knolls chrome hill parkhouse hill and thorpe cloud the chrome hill phenomenon is observed from glutton bridge for a short period around the summer solstice the sun sets just to the southwest of the summit of the hill begins to re emerge almost immediately afterwards from its steep northeastern slope before fully reappearing and later sets for a second and final time at the foot of the hill the parkhouse hill occurrence is visible from nearby glutton grange in late march early april and september the sun sets just to the south of the summit of the hill begins to re emerge almost immediately afterwards from its steep northern slope before fully reappearing and later sets for a second and final time at the foot of the hill the thorpe cloud event is viewed from the top of nearby lin dale on and around the summer solstice and perhaps beyond the sun sets on the summit of the hill partially reappears from its steep northern slope and sets for a second and final time shortly afterwards
double top and double bottom are reversal chart patterns observed in the technical analysis of financial trading markets of stocks commodities currencies and other assets
doubling the cube also known as the delian problem is an ancient geometric problem given the edge of a cube the problem requires the construction of the edge of a second cube whose volume is double that of the first using only the tools of a compass and straightedge as with the related problems of squaring the circle and trisecting the angle doubling the cube is now known to be impossible the egyptians indians and particularly the greeks were aware of the problem and made many futile attempts at solving what they saw as an obstinate but soluble problem however the nonexistence of a solution was finally proven by pierre wantzel in 1837 in algebraic terms doubling a unit cube requires the construction of a line segment of length x where x 3 2 in other words x 3 √ 2 this is because a cube of side length 1 has a volume of 13 1 and a cube of twice that volume a volume of 2 has a side length of the cube root of 2 the impossibility of doubling the cube is therefore equivalent to the statement that 3 √ 2 is not a constructible number this is a consequence of the fact that the coordinates of a new point constructed by a compass and straightedge are roots of polynomials over the field generated by the coordinates of previous points of no greater degree than a quadratic this implies that the degree of the field extension generated by a constructible point must be a power of 2 the field extension generated by 3 √ 2 however is of degree 3
doucas and kapetanakis pigmented purpura is a skin condition characterized by scaly and eczematous patches which also have petechiae and hemosiderin staining it is also known as eczematoid purpura or eczematoid like purpura it was characterized in 1953
the dove pan is a classic magic effect in which a magician produces a dove from an empty pan the illusion continues to be performed by professional and amateur magicians the effect consists of a shallow pan made of brass or aluminium and a matching lid which has a very deep rim or shoulder all around that fits inside the pan when closed the pan is usually no more than ten inches in diameter and roughly 2 3 inches deep dove pans are a common item at magicians supply stores in presentation the magician demonstrates that the pan is empty and then fills it with a small quantity of a volatile liquid which is ignited often the magician will place other items in the pan e g cracking an egg into it before setting the fuel on fire to extinguish the fire the magician slams the lid onto the pan when the magician removes the lid a dove flies from the pan which is shown to be otherwise empty
the dowd – beckwith ring expansion reaction is an organic reaction in which a cyclic β keto ester is expanded by up to 4 carbons in a free radical ring expansion reaction through an α alkylhalo substituent the radical initiator system is based on aibn and tributyltin hydride the cyclic β keto ester can be obtained through a dieckmann condensation the original reaction consisted of a nucleophilic aliphatic substitution of the enolate of ethyl cyclohexanone 2 carboxylate with 1 4 diiodobutane and sodium hydride followed by ring expansion to ethyl cyclodecanone 6 carboxylate a side reaction is organic reduction of the iodoalkane dowd – beckwith ring expansion gif
down syndrome ds or dns also known as trisomy 21 is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21 it is typically associated with physical growth delays characteristic facial features and mild to moderate intellectual disability the average iq of a young adult with down syndrome is 50 equivalent to the mental age of an 8 or 9 year old child but this can vary widely the parents of the affected individual are typically genetically normal the extra chromosome occurs by random chance the risk increases from less than 0 1 in 20 year old mothers to 3 in those age 45 there is no known behavioral activity or environmental factor that changes the risk down syndrome can be identified during pregnancy by prenatal screening followed by diagnostic testing or after birth by direct observation and genetic testing since the introduction of screening pregnancies with the diagnosis are often terminated regular screening for health problems common in down syndrome is recommended throughout the person s life there is no cure for down syndrome education and proper care have been shown to improve quality of life some children with down syndrome are educated in typical school classes while others require more specialized education some individuals with down syndrome graduate from high school and a few attend post secondary education in adulthood about 20 in the united states do paid work in some capacity with many requiring a sheltered work environment support in financial and legal matters is often needed life expectancy is around 50 to 60 years in the developed world with proper health care down syndrome is one of the most common chromosome abnormalities in humans it occurs in about one per 1000 babies born each year in 2013 down syndrome was present in 8 5 million individuals and resulted in 36 000 deaths down from 43 000 deaths in 1990 it is named after john langdon down the british doctor who fully described the syndrome in 1866 some aspects of the condition were described earlier by jean étienne dominique esquirol in 1838 and édouard séguin in 1844 the genetic cause of down syndrome — an extra copy of chromosome 21 — was identified by french researchers in 1959
downstep is a phenomenon in language where when two syllables have the same tone for example both have high tone or both have mid tone the second syllable is lower in pitch than the first two main kinds of downstep can be distinguished the first more usually called automatic downstep downdrift or catathesis occurs when high and low tones come in the sequence h l l h then the second high tone tends to be lower than the first because of the intervening low toned syllable this phenomenon is common in african languages it has also been argued that it is this same phenomenon which causes english sentences such as i really believe ebenezer was a dealer in magnesium or i bought blueberries bayberries raspberries mulberries and brambleberries if these sentences are pronounced with a falling intonation to fall gradually in pitch with each accented syllable here underlined slightly lower than the last downstep proper or non automatic downstep on the other hand is a phenomenon found especially in west african languages such as igbo when of two high tones in succeeding syllables that is in the sequence h h the second is lower than the first in such languages when two high tones come one after the other either they are at the same height or if there is a downstep the second one is lower the second high tone is also lower than the preceding one if there is an intervening low in the sequence h l h as described above thus the high tones in a simple sentence tend to descend downwards from the beginning to the end of the sentence in a series of steps a phenomenon known as tone terracing the symbol for this second kind of downstep in the international phonetic alphabet is a superscript down arrow ↓ it is common to see a superscript exclamation mark used instead due to typographic constraints it has been shown that in most if not all cases of downstep proper the lowering of the second high tone is caused because an intervening low toned syllable has dropped out i e what was formerly h l h has become h h this missing low toned syllable creates what is known as a floating tone an example occurs in bambara a language spoken in mali in this language the definite article is a floating low tone with a noun in isolation it docks to the preceding vowel turning a high tone into a falling tone however when it occurs between two high tones it downsteps the following tone japanese pitch accent may be compared to this about 80 of japanese words have an evenly rising pitch something like french which carries over onto a following unstressed grammatical particle however about 20 of words have a drop in pitch between syllables or before a grammatical particle an example is in isolation like this the first word has a high low pitch whereas the second and third are homonyms with a low high pitch the first syllable is only low when the word is said in isolation however all three are distinct when followed by the nominative particle ga
the doyle – kirmse reaction is an organic reaction in which in the original scope an allyl sulfide reacts with trimethylsilyldiazomethane to form the homoallyl sulfide compound the reaction was first reported by w kirmse in 1968 and modified by m p doyle in 1981 doyle kirmse reaction the kirmse protocol required a copper salt the reaction type is nucleophilic addition of sulfur to a metal carbene formed from the diazoalkane followed by a stevens like rearrangement doyle expanded the scope of the reaction to include diazo compounds such as ethyl diazoacetate allyl amines and allyl halides with rhodium catalysts such as hexadecacarbonylhexarhodium an example is the reaction of ethyl diazoacetate with allyl iodide doyle diazo compound reaction the reaction can also be catalyzed by iron palladium and silver modifications using other carbenes are reported e g 2 furyl carbenoids with use of certain propargyl sulfides the reaction product is an allene
dracunculiasis also called guinea worm disease gwd is an infection by the guinea worm a person becomes infected when they drink water that contains water fleas infected with guinea worm larvae initially there are no symptoms about one year later the person develops a painful burning feeling as the female worm forms a blister in the skin usually on the lower limb the worm then comes out of the skin over the course of a few weeks during this time it may be difficult to walk or work it is very uncommon for the disease to cause death in humans the only known cause is dracunculus medinensis the worm is about one to two millimeters wide and an adult female is 60 to 100 centimeters long males are much shorter at 12 – 29 mm or 0 47 – 1 14 in outside of humans the young form can survive up to three weeks during which they must be eaten by water fleas to continue to develop the larva inside water fleas may survive up to four months thus in order for the disease to remain in an area it must occur each year in humans a diagnosis of the disease can usually be made based on the signs and symptoms of the disease prevention is by early diagnosis of the disease followed by keeping the person from putting the wound in drinking water to decrease spread of the parasite other efforts include improving access to clean water and otherwise filtering water if it is not clean filtering through a cloth is often enough contaminated drinking water may be treated with a chemical called temefos to kill the larva there is no medication or vaccine against the disease the worm may be slowly removed over a few weeks by rolling it over a stick the ulcers formed by the emerging worm may get infected by bacteria pain may continue for months after the worm has been removed in 2015 there were 22 reported cases of the disease and in the first half of 2016 there were 7 confirmed cases this is down from an estimated 3 5 million cases in 1986 it only exists in 4 countries in africa down from 20 countries in the 1980 s it will likely be the first parasitic disease to be globally eradicated guinea worm disease has been known since ancient times it is mentioned in the egyptian medical ebers papyrus dating from 1550 bc the name dracunculiasis is derived from the latin affliction with little dragons while the name guinea worm appeared after europeans saw the disease on the guinea coast of west africa in the 17 th century other dracunculus species are known to infect various mammals but do not appear to infect humans dracunculiasis is classified as a neglected tropical disease because dogs may also become infected the eradication program is monitoring and treating dogs as well
in engineering draft is the amount of taper for molded or cast parts perpendicular to the parting line it can be measured in degrees or mm mm in in consider the fabrication of a hollow plastic box without lid once the plastic has hardened around the mold the mold must be removed as the plastic hardens it may contract slightly by tapering the sides of the mold by an appropriate draft angle for instance 2 ° two degrees the mold will be easier to remove this is a practice that is used in applicable cases when working with fiberglass if the mold is to be removed from the top the box should taper in towards the bottom such that measuring the bottom internal dimension will yield a smaller length and width than measuring the top from which the mold is extracted by specifying the opening length and width a draft angle and a depth it is not necessary to specify the dimensions for the internal surface as these may be calculated from the above the manufacture of a part that incorporates zero or negative angles may require a mold that can be separated into two or more parts in order to release the casting
in fluid dynamics drag crisis is a phenomenon in which drag coefficient drops off suddenly as reynolds number increases this has been well studied for round bodies like spheres and cylinders the drag coefficient of a sphere will change rapidly from about 0 5 to 0 2 at a reynolds number in the range of 300000 this corresponds to the point where the flow pattern changes leaving a narrower turbulent wake the behaviour is highly dependent on small differences in the condition of the surface of the sphere
a drainage basin or catchment basin is an extent or an area of land where all surface water from rain melting snow or ice converges to a single point at a lower elevation usually the exit of the basin where the waters join another body of water such as a river lake reservoir estuary wetland sea or ocean thus if a tributary stream joins a brook that in turn joins a small river which is a tributary of a larger river there is a series of successively larger and lower elevation drainage basins for instance the missouri and ohio rivers are within their own drainage basins and also within the drainage basin of the mississippi river other terms used to describe drainage basins are catchment catchment area drainage area river basin and water basin in north america the term watershed is commonly used to mean a drainage basin though in other english speaking countries it is used only in its original sense to mean a drainage divide the former meaning an area the latter the high elevation perimeter of that area drainage basins drain into other drainage basins in a hierarchical pattern with smaller sub drainage basins combining into larger drainage basins in closed endorheic drainage basins the water converges to a single point inside the basin known as a sink which may be a permanent lake a dry lake or a point where surface water is lost underground the drainage basin includes all the streams and rivers that convey the water towards the sink as well as the land surfaces from which water drains into those channels the drainage basin acts as a funnel by collecting all the water within the area covered by the basin and channelling it to a single point each drainage basin is separated topographically from adjacent basins by a perimeter the drainage divide making up a succession of higher geographical features such as a ridge hill or mountains forming a barrier drainage basins are similar but not identical to hydrologic units which are drainage areas delineated so as to nest into a multi level hierarchical drainage system hydrologic units are defined to allow multiple inlets outlets or sinks in a strict sense all drainage basins are hydrologic units but not all hydrologic units are drainage basins
in geomorphology drainage systems also known as river systems are the patterns formed by the streams rivers and lakes in a particular drainage basin they are governed by the topography of the land whether a particular region is dominated by hard or soft rocks and the gradient of the land geomorphologists and hydrologists often view streams as being part of drainage basins a drainage basin is the topographic region from which a stream receives runoff throughflow and groundwater flow the number size and shape of the drainage basins found in an area vary and the larger the topographic map the more information on the drainage basin is available
drama theory is one of the problem structuring methods in operations research it is based on game theory and adapts the use of games to complex organisational situations accounting for emotional responses that can provoke irrational reactions and lead the players to redefine the game in a drama emotions trigger rationalizations that create changes in the game and so change follows change until either all conflicts are resolved or action becomes necessary the game as redefined is then played drama theory was devised by professor nigel howard in the early 90 s and since then has been turned to defense political health industrial relations and commercial applications drama theory is an extension of howard s metagame analysis work developed at the university of pennsylvania in the late 1960 s and presented formally in his book paradoxes of rationality published by mit press metagame analysis was originally used to advise on the strategic arms limitation talks salt
drapetomania was a conjectural mental illness that in 1851 american physician samuel a cartwright hypothesized to cause black slaves to flee captivity it has since been debunked as pseudoscience and part of the edifice of scientific racism
dravet syndrome also known as severe myoclonic epilepsy of infancy smei is a type of epilepsy with seizures that are often triggered by hot temperatures or fever it often begins around six months of age
draw limit is a restriction on number of games drawn in a season it was an administrative measure in league football competitions that was implemented in the soviet union by the football federation of the soviet union in 1978 1988 the reason for such measure was to fight match fixing as well as increase the entertainment and intensity of the national championship the limit provided that over certain set number of allowed draws no points were awarded for any additional drawn games for example if the federation set the draw limit at 10 for a given championship points were awarded to teams only for the first 10 drawn games and none for any additional
in automotive engineering drawbar pull is the amount of horizontal force available to a vehicle at the drawbar for accelerating or pulling a load drawbar pull is a function of velocity and in general decreases as the speed of the vehicle increases due both to increasing resistance and decreasing transmission gear ratios drawbar pull is the difference between tractive effort available and tractive effort required to overcome resistance at a specified speed drawbar pull data for a vehicle is usually determined by measuring the amount of available tractive force using a dynamometer and then combining that data with coastdown data to obtain the available drawbar pull force at each speed
dream telepathy is the purported ability to communicate telepathically with another person while one is dreaming the first person in modern times to document telepathic dreaming was sigmund freud in the 1940 s it was the subject of the eisenbud pederson krag fodor ellis controversy named after the preeminent psychoanalysts of the time who were involved jule eisenbud geraldine pederson krag nandor fodor and albert ellis there is no scientific evidence that dream telepathy is a real phenomenon parapsychological experiments into dream telepathy have not produced replicable results
dressler syndrome is a secondary form of pericarditis that occurs in the setting of injury to the heart or the pericardium the outer lining of the heart it consists of fever pleuritic pain pericarditis and or a pericardial effusion dressler syndrome is also known as postmyocardial infarction syndrome and the term is sometimes used to refer to post pericardiotomy pericarditis it was first characterized by william dressler at maimonides medical center in 1956 it should not be confused with the dressler s syndrome of haemoglobinuria named for lucas dressler who characterized it in 1854
in the dungeons and dragons roleplaying game a drider is an aberration that was formerly a drow dark elf driders are centaur like creatures in the game appearing as drow from the waist up with their lower portions replaced by the abdomen and legs of immense spiders they are most commonly found in the underdark
drift migration is the phenomenon in which migrating birds are blown off course by the winds while they are in flight it is more likely to happen to birds heading south in autumn because the large numbers of inexperienced young birds are less able to compensate than the adults heading north in spring drift is assisted by disorientating conditions such as mist or drizzle and can result in large numbers of birds arriving together in an area in which they are not normally seen in the uk this is called a fall while in the u s it is known as a fallout though in the latter case it need not involve vagrant birds an example would be an east wind in september blowing scandinavian migrants such as bluethroats wrynecks and the continental race of robin onto the east coast of england and scotland leading to temporary concentrations of these species at headlands like spurn
the driver scheduling problem dsp is type of problem in operations research and theoretical computer science the dsp consists of selecting a set of duties assignments for the drivers or pilots of vehicles e g buses trains boats or planes involved in the transportation of passengers or goods this very complex problem involves several constraints related to labour and company rules and also different evaluation criteria and objectives being able to solve this problem efficiently can have a great impact on costs and quality of service for public transportation companies there is a large number of different rules that a feasible duty might be required to satisfy such as minimum and maximum stretch duration minimum and maximum break duration minimum and maximum work duration minimum and maximum total duration maximum extra work duration maximum number of vehicle changes minimum driving duration of a particular vehicle operations research has provided optimization models and algorithms that lead to efficient solutions for this problem among the most common models proposed to solve the dsp are the set covering and set partitioning models spp scp in the spp model each work piece task is covered by only one duty in the scp model it is possible to have more than one duty covering a given work piece in both models the set of work pieces that needs to be covered is laid out in rows and the set of previously defined feasible duties available for covering specific work pieces is arranged in columns the dsp resolution based on either of these models is the selection of the set of feasible duties that guarantees that there is one spp or more scp duties covering each work piece while minimizing the total cost of the final schedule
dromomania also travelling fugue is an uncontrollable psychological urge to wander people with this condition spontaneously depart from their routine travel long distances and take up different identities and occupations in the common english vernacular this is often rendered simply as wanderlust directly from the german although dromomania does imply a psychological compulsion usually on one s own and often without one s conscious knowledge rather than a more generalised desire to travel the most famous case was that of jean albert dadas a bordeaux gas fitter dadas would suddenly set out on foot and reach cities as far away as prague vienna or moscow with no memory of his travels a medical student philippe tissie wrote about dadas in his doctoral dissertation in 1887 jean martin charcot presented a similar case he called automatisme ambulatoire french for ambulatory automatism or walking around without being in control of one s own actions more generally the term is sometimes used to describe people who have a strong emotional or even physical need to be constantly traveling and experiencing new places often at the expense of their normal family work and social lives
in music a drone is a harmonic or monophonic effect or accompaniment where a note or chord is continuously sounded throughout most or all of a piece the word drone is also used to refer to any part of a musical instrument that is just used to produce such an effect as is the archaic term burden bourdon or burdon such as the drone pipe of a bagpipe the pedal point in an organ or the lowest course of a lute burden also refers to a part of a song that is repeated at the end of each stanza such as the chorus or refrain the term comes from the french bourdon a staff or a pipe made in the form of a staff the drone does not take its name from the bee it is a far older word sharing an indo european root dhran to drone to hum with the sanskrit dhran the greek thren os and the english thrum drum and dream
drooling also known as salivation driveling dribbling slobbering or in a medical context sialorrhea is the flow of saliva outside the mouth drooling can be caused by excess production of saliva inability to retain saliva within the mouth incontinence of saliva or problems with swallowing dysphagia or odynophagia frequent and harmless cases are a numbed mouth from either orajel or when going to the dentist office isolated drooling in healthy infants and toddlers is normal and is unlikely to be a sign of either disease or complications it may be associated with teething drooling in infants and young children may be exacerbated by upper respiratory infections and nasal allergies some people with drooling problems are at increased risk of inhaling saliva food or fluids into the lungs mainly if drooling is secondary to a neurological problem however if the body s normal reflex mechanisms such as gagging and coughing are not impaired this is not life threatening
in graphic design a drop shadow is a visual effect consisting of a drawing element which looks like the shadow of an object giving the impression that the object is raised above the objects behind it the drop shadow is often used for elements of a graphical user interface such as windows or menus and for simple text the text label for icons on desktops in many desktop environments has a drop shadow as this effect effectively distinguishes the text from any colored background it may be in front of a simple way of drawing a drop shadow of a rectangular object is to draw a gray or black area underneath and offset from the object in general a drop shadow is a copy in black or gray of the object drawn in a slightly different position realism may be increased by 1 darkening the colors of the pixels where the shadow casts instead of making them gray this can be done with alpha blending the shadow with the area it is cast on 2 softening the edges of the shadow this can be done by adding gaussian blur to the shadow s alpha channel before blending
a dropout is a momentary loss of signal in a communications system usually caused by noise propagation anomalies or system malfunctions for analog signals a dropout is frequently gradual and partial depending on the cause for digital signals dropouts are more pronounced usually being sudden and complete due to the cliff effect in mobile telephony a dropout of more than a few seconds will result in a dropped call
in electronics the dropout voltage of a voltage regulator is the smallest possible difference between the input voltage and output voltage to remain inside the regulator s intended operating range for example a regulator with 5 volt output and 2 volt dropout voltage rating will only output 5 volts if the input voltage is above 7 volts 7 volt input 5 volt output 2 volt dropout if the input falls below 7 volts the output will fail to regulate to 5 volts dropout voltage can be as high as 2 volts for a general purpose integrated circuit regulator such as the 78 xx series but a low dropout regulator may have a dropout of less than 100 mv at full load dropout voltage will vary depending on the load on the regulator usually increasing under higher load due to the internal resistance of the regulator s pass transistor and circuitry dropout voltage also varies with respect to temperature dropout voltage is usually specified over a range of loads and temperatures dropout voltage and quiescent current determine the efficiency of the voltage regulator lower dropout voltage improves efficiency
the drought in the northeast region of brazil is a natural phenomenon resulting from lack of rain in the aforementioned region of brazil which has high temperatures with low rainfall during the year
drowning is defined as respiratory impairment from being in or under a liquid it is further classified by outcome into death ongoing health problems and no ongoing health problems using the term near drowning to refer to those who survive is no longer recommended drowning itself is quick and silent although it may be preceded by distress which is more visible generally in the early stages of drowning very little water enters the lungs a small amount of water entering the trachea causes a muscular spasm that seals the airway and prevents the passage of both air and water until unconsciousness occurs this means a person drowning is unable to shout or call for help or seek attention as they cannot obtain enough air the instinctive drowning response is the final set of autonomic reactions in the 20 – 60 seconds before sinking underwater and to the untrained eye can look similar to calm safe behavior lifeguards and other persons trained in rescue learn to recognize drowning people by watching for these movements in 2013 there were about 1 7 million cases of drowning unintentional drowning is the third leading cause of unintentional injury resulting in death worldwide in 2013 it was estimated to have resulted in 368 000 deaths down from 545 000 deaths in 1990 of these deaths 82 000 occurred in children less than five years old it accounts for 7 of all injury related deaths excluding those due to natural disasters with 91 of these deaths occurring in low income and middle income countries drowning occurs more frequently in males and the young the rate of drowning in populations around the world varies widely according to their access to water the climate and the national swimming culture
a drug eluting stent des is a peripheral or coronary stent a scaffold placed into narrowed diseased peripheral or coronary arteries that slowly releases a drug to block cell proliferation this prevents fibrosis that together with clots thrombi could otherwise block the stented artery a process called restenosis the stent is usually placed within the peripheral or coronary artery by an interventional cardiologist or interventional radiologist during an angioplasty procedure drug eluting stents in current clinical use were approved by the fda after clinical trials showed they were statistically superior to bare metal stents for the treatment of native coronary artery narrowings having lower rates of major adverse cardiac events usually defined as a composite clinical endpoint of death myocardial infarction repeat intervention because of restenosis the first drug eluting stents to be approved in europe and the u s were coated with paclitaxel or an mtor inhibitor such as sirolimus
drug induced angioedema is a known complication of the use of angiotensin converting enzyme ace inhibitors angiotensin ii antagonists arbs and angiotensin neprilysin inhibitor lcz 969 the angioedema appears to be dose dependent as it may resolve with decreased dose some common ace inhibitors are benazepril lotensin captopril capoten enalapril vasotec lisinopril prinivil zestril ramipril altace some common arbs are candesartan atacand losartan cozaar olmesartan benicar valsartan diovan angioedema presents itself as an abrupt onset of non pitting non itchy swelling that involves the mucosal layers some common locations of angioedema are the face particularly the lips and around the eyes hands and feet and genitalia a rare yet serious complication is one inside the abdomen the symptom usually being severe stomach upset which is much less obvious than the other locations the chance of drug induced angioedema is extremely uncommon however as studies show incidence of less than 1 the reason this adverse effect may occur is due to the build up of bradykinin a vasodilator this causes blood vessels to dilate and allow for fluid buildup in the mucosal surfaces
drug induced autoimmune hemolytic anemia is a form of hemolytic anemia in some cases a drug can cause the immune system to mistakenly think the body s own red blood cells are dangerous foreign substances antibodies then develop against the red blood cells the antibodies attach to red blood cells and cause them to break down too early drugs that can cause this type of hemolytic anemia include cephalosporins a class of antibiotics – most common cause dapsone levodopa levofloxacin methyldopa nitrofurantoin nonsteroidal anti inflammatory drugs nsaids phenazopyridine pyridium quinidine penicillin in high doses can induce immune mediated hemolysis via the hapten mechanism in which antibodies are targeted against the combination of penicillin in association with red blood cells complement is activated by the attached antibody leading to the removal of red blood cells by the spleen the drug itself can be targeted by the immune system e g by ige in a type i hypersensitivity reaction to penicillin rarely leading to anaphylaxis
drug induced fever is a symptom of an adverse drug reaction wherein the administration of drugs intended to help a patient causes a hypermetabolic state resulting in fever the drug may interfere with heat dissipation peripherally increase the rate of metabolism evoke a cellular or humoral immune response mimic endogenous pyrogen or damage tissues
drug induced keratoderma is a cutaneous condition characterized by a hornlike skin texture
drug induced lipodystrophy is a cutaneous condition that presents as one or multiple depressed areas i e indentations usually on the proximal extremities ranging from under a few centimeters to greater than 20 cm in diameter
drug induced lupus erythematosus dil or dile is an autoimmune disorder similar to systemic lupus erythematosus sle caused by chronic use of certain drugs these drugs cause an autoimmune response the body attacks its own cells producing symptoms similar to those of sle there are 38 known medications to cause dil but there are three that report the highest number of cases hydralazine procainamide and isoniazid while the criteria for diagnosing dil has not been thoroughly established symptoms of dil typically present as muscle pain and joint pain generally the symptoms recede after discontinuing use of the drugs
drug induced nonautoimmune hemolytic anemia is a form of hemolytic anemia non immune drug induced hemolysis can occur via oxidative mechanisms this is particularly likely to occur when there is an enzyme deficiency in the antioxidant defense system of the red blood cells an example is where antimalarial oxidant drugs like primaquine damage red blood cells in glucose 6 phosphate dehydrogenase deficiency in which the red blood cells are more susceptible to oxidative stress due to reduced nadph production consequent to the enzyme deficiency some drugs cause rbc red blood cell lysis even in normal individuals these include dapsone and sulfasalazine non immune drug induced hemolysis can also arise from drug induced damage to cell volume control mechanisms for example drugs can directly or indirectly impair regulatory volume decrease mechanisms which become activated during hypotonic rbc swelling to return the cell to a normal volume the consequence of the drugs actions are irreversible cell swelling and lysis e g ouabain at very high doses
drug induced skin disorders may take on many different appearances one of the most common being a change in the color or pigmentation of the skin
drug induced pruritus is itchiness of the skin caused by medication a pruritic reaction that is generalized
drug induced pseudolymphoma results from exposure to medications which results in cutaneous inflammatory patterns that resemble lymphoma most frequently mycosis fungoides
drug induced purpura is a skin condition that may be related to platelet destruction vessel fragility interference with platelet function or vasculitis
drug induced thrombocytopenic purpura is a skin condition result from a low platelet count due to drug induced anti platelet antibodies caused by drugs such as heparin sulfonamines digoxin quinine and quinidine
drug induced urticaria occurs by immunologic and nonimmunologic mechanisms urticaria most commonly caused by aspirin and nsaids
drug related gingival hyperplasia is a cutaneous condition characterized by enlargement of the gums noted during the first year of drug treatment there are three drug classes that are associated with this condition namely anticonvulsants such as phenyotoin and phenobartibal calcium channel blocker such as amlopidine nifedipine and verapamil and ciclosporin an immunosuppressant although the mechanism of drug related gingival hyperplasia is not well understood some risk factors for the condition include the duration of drug use and poor oral hygiene in most cases alternative drugs are given in order to avoid this side effect
a drug allergy is an allergy to a drug most commonly a medication medical attention should be sought immediately if an allergic reaction is suspected an allergic reaction will not occur on the first exposure to a substance the first exposure allows the body to create antibodies and memory lymphocyte cells for the antigen however drugs often contain many different substances including dyes which could cause allergic reactions this can cause an allergic reaction on the first administration of a drug for example a person who developed an allergy to a red dye will be allergic to any new drug which contains that red dye a drug allergy is different from an intolerance a drug intolerance which is often a milder non immune mediated reaction does not depend on prior exposure most people who believe they are allergic to aspirin are actually suffering from a drug intolerance
in medicine a drug eruption is an adverse drug reaction of the skin most drug induced cutaneous reactions are mild and disappear when the offending drug is withdrawn these are called simple drug eruptions however more serious drug eruptions may be associated with organ injury such as liver or kidney damage and are categorized as complex drugs can also cause hair and nail changes affect the mucous membranes or cause itching without outward skin changes
the term drug overdose or simply overdose or od describes the ingestion or application of a drug or other substance in quantities greater than are recommended or generally practiced an overdose may result in a toxic state or death
drug withdrawal is the group of symptoms that occur upon the abrupt discontinuation or decrease in intake of medications or recreational drugs in order to experience the symptoms of withdrawal one must have first developed a physical or mental dependence this happens after consuming one or more substances for a certain period of time which is both dose dependent and varies based upon the drug consumed for example prolonged use of an anti depressant is most likely to cause a much different reaction when discontinued than the repeated use of an opioid such as heroin withdrawal symptoms from opiate abuse such as heroin morphine include anxiety sweating vomiting and diarrhea alcohol abuse withdrawal symptoms include irritability fatigue shaking sweating and nausea withdrawal from nicotine brings on irritability fatigue insomnia headache and difficulty concentrating symptoms and body response to the absence can vary from mild discomfort or to the return of previous underlying medical problems and their respective symptoms many legal and unrestricted chemicals and or substances available without prescriptions and over the counter can cause withdrawal effects when users stop consuming them even if taken as directed the route of administration whether intravenous intramuscular oral or otherwise can also play a role in determining the severity of withdrawal symptoms there are different stages of withdrawal as well generally a person will start to feel bad crash or come down progress to feeling worse hit a plateau and then the symptoms begin to dissipate however withdrawal from certain drugs benzodiazepines alcohol glucocorticoids can be fatal while it is seldom fatal to the user withdrawal from opiates and some other drugs can cause miscarriage due to fetal withdrawal the term cold turkey is used to describe the sudden cessation use of a substance and the ensuing physiologic manifestations the symptoms from withdrawal may be even more dramatic when the drug has masked prolonged malnutrition disease chronic pain infections common in intravenous drug use or sleep deprivation conditions that drug abusers often suffer as a secondary consequence of the drug many drugs including alcohol suppress appetite while simultaneously consuming any money that might have been spent on food when the drug is removed the discomforts return in force and are sometimes confused with addiction withdrawal symptoms
a drum beat or drum pattern is a rhythmic pattern or repeated rhythm establishing the meter and groove through the pulse and subdivision played on drum kits and other percussion instruments as such a beat consists of multiple drum strokes occurring over multiple musical beats while the term drum beat may also refer to a single drum stroke which may occupy more or less time than the current pulse many drum beats define or are characteristic of specific music genres many basic drum beats establish the pulse through alternating bass on the on beats and snare drums on the off beats strokes while establishing the subdivision on the ride cymbal thus its name or hi hat this establishes a quarter note pulse in quad duple time each measure is formed from two groups of two quarter note pulses each pulse divided into two eighth notes this establishes a quarter note pulse in triple time each measure is formed from three quarter note pulses each divided into two eighth notes this establishes a dotted quarter note pulse in duple time each measure is formed from two dotted quarter note pulses each pulse divided into three eighth notes compound triple meter is equivalent to simple duple meter with triplets on every beat this establishes a dotted quarter note pulse in triple time each measure is formed from three dotted quarter note pulses each pulse divided into three eighth notes a fill is played in between the regular strokes of a pattern and or signals the end of a phrase since a phrase is multiple measures long a fill signaling the end of one would come at the end of the last in a series of repeated measures in double and half time patterns the pulse and ride are either doubled or halved respectively occurring twice or half as often a blast beat drum pattern features all drums on the eighth note subdivision or variants with one or more drum s pattern displaced by a sixteenth note this resembles a combination of double time bass snare pattern and original time ride pattern despite the difference in notation there is no difference in interonset intervals and this pattern is nearly identical to the first simple duple pattern except for the second onbeat being divided into two eighth notes and of course the second backbeat being delayed an eighth note the heavy metal gallop named for a horse s canter is based on a bass drum pattern of one eighth followed by two sixteenths
drusen singular druse are tiny yellow or white accumulations of extracellular material that build up between bruch s membrane and the retinal pigment epithelium of the eye the presence of a few small hard drusen is normal with advancing age and most people over 40 have some hard drusen however the presence of larger and more numerous drusen in the macula is a common early sign of age related macular degeneration amd
dry eye syndrome des also known as keratoconjunctivitis sicca kcs is the condition of having dry eyes other associated symptoms include irritation redness discharge and easily fatigued eyes blurred vision may also occur the symptoms can range from mild and occasional to severe and continuous scarring of the cornea may occur in some cases without treatment dry eye occurs when either the eye does not produce enough tears or when the tears evaporate too quickly this can result from meibomian gland dysfunction allergies pregnancy sjogren s syndrome vitamin a deficiency lasik surgery and certain medications such as antihistamines some blood pressure medication hormone replacement therapy and antidepressants chronic conjunctivitis such as from tobacco smoke exposure or infection may also lead to the condition diagnosis is mostly based on the symptoms though a number of other tests may be used treatment depends on the underlying cause artificial tears are the usual first line treatment wrap around glasses that fit close to the face may decrease tear evaporation stopping or changing certain medications may help the medication ciclosporin or steroid eye drops may be used in some cases another opinion is lacrimal plugs that prevent tears from draining from the surface of the eye dry eyes occasionally makes wearing contact lenses impossible dry eye syndrome is a common eye disease it affects 5 34 of people to some degree depending on the population looked at among older people it affects up to 70 in china it affects about 17 of people the phrase keratoconjunctivitis sicca means dryness of the cornea and conjunctiva in latin
dryness is a medical condition in which there is local or more generalized decrease in normal lubrication of the skin or mucous membranes examples of local dryness include dry mouth dry eyes dry skin and vaginal dryness these often have specific causes and treatments it is possible to have dry eyes without any other signs or symptoms but this usually causes a syndrome of eye symptoms called keratoconjunctivitis sicca more generalized dryness can be caused by e g dehydration that is more general loss of body fluids anticholinergic drugs and sjögren syndrome
dubois sign is a medical finding of shortness of the little finger in congenital syphilis
dual role transvestism is the formal diagnosis used by psychologists and physicians to describe people who wear clothes of the opposite sex to experience being the opposite sex temporarily but don t have a sexual motive or want gender reassignment surgery the international classification of diseases icd 10 list three diagnostic criteria for dual role transvestism f 64 1 a person who is diagnosed with dual role transvestism should not receive a diagnosis of transvestic fetishism f 65 1
dual diagnosis also called co occurring disorders cod is the condition of suffering from a mental illness and a comorbid substance abuse problem there is considerable debate surrounding the appropriateness of using a single category for a heterogeneous group of individuals with complex needs and a varied range of problems the concept can be used broadly for example depression and alcoholism or it can be restricted to specify severe mental illness e g psychosis schizophrenia and substance misuse disorder e g cannabis abuse or a person who has a milder mental illness and a drug dependency such as panic disorder or generalized anxiety disorder and is dependent on opioids diagnosing a primary psychiatric illness in substance abusers is challenging as drug abuse itself often induces psychiatric symptoms thus making it necessary to differentiate between substance induced and pre existing mental illness those with co occurring disorders face complex challenges they have increased rates of relapse hospitalization homelessness and hiv and hepatitis c infection compared to those with either mental or substance use disorders alone the cause of co occurring disorders is unknown although there are several theories
representational insight is the ability to detect and mentally represent the relation between a symbol and its referent whether or not a child gains this insight depends on the similarity between the symbol and its referent the level of information provided about the relationship between the symbol and the referent and a child s prior experience with symbols an essential part of representational insight is dual representation or the existence of multiple mental representations of a single symbolic entity judy deloache coined this term after conducting many studies in which young children would watch an experimenter hide a toy in a model room and were then asked to retrieve a similar but larger toy from a larger room
a dual therapy stent is a coronary artery stent that combines the technology of a bioengineered stent and a drug eluting stent to both accelerate endothelial coverage healing of the vessel and to block cell proliferation thereby reducing the risk of restenosis the combo dual therapy stent orbusneich is the only dual therapy stent available today it combines the genous endothelial progenitor cell capture technology with an antiproliferative biodegradable sirolimus drug elution the combo stent has received ce mark approval in europe and was shown to be as effective as a paclitaxel eluting stent in controlling neointimal hyperplasia
duane radial ray syndrome is a rare disorder that affects the eyes and causes abnormalities of bones in the arms and hands
duane syndrome is a congenital rare type of strabismus most commonly characterized by the inability of the eye to move outwards the syndrome was first described by ophthalmologists jakob stilling 1887 and siegmund türk 1896 and subsequently named after alexander duane who discussed the disorder in more detail in 1905 other names for this condition include duane s retraction syndrome eye retraction syndrome retraction syndrome congenital retraction syndrome and stilling türk duane syndrome
duarte galactosemia also known as duarte variant galactosemia dg or biochemical variant galactosemia is an inherited condition associated with diminished ability to metabolize galactose due to a partial deficiency of the enzyme galactose 1 phosphate uridylyltransferase duarte galactosemia dg is estimated to affect close to one in 4 000 infants born in the united states dg is considered by most healthcare professionals to be clinically mild it differs from classic galactosemia in that patients with duarte galactosemia have partial galt deficiency whereas patients with classic galactosemia have complete or almost complete galt deficiency dg and the possible outcomes associated with this condition are currently not well understood due to regional variations in newborn screening nbs protocols some infants with dg are identified by nbs but others are not in addition of the infants who are diagnosed most are clinically healthy as babies and toddlers resulting in early discharge from follow up many healthcare professionals believe that dg does not negatively impact development however some reports have indicated that children with dg may be at increased risk for some developmental problems
dubin – johnson syndrome djs is a rare autosomal recessive benign disorder that causes an isolated increase of conjugated bilirubin in the serum classically the condition causes a black liver due to the deposition of a pigment similar to melanin this condition is associated with a defect in the ability of hepatocytes to secrete conjugated bilirubin into the bile and is similar to rotor syndrome it is usually asymptomatic but may be diagnosed in early infancy based on laboratory tests no treatment is usually needed
dubowitz syndrome is a rare genetic disorder characterized by microcephaly growth retardation and a characteristic facial appearance small round triangular shaped with a pointed receding chin a broad wide tipped nose and wide set eyes with drooping eyelids symptoms vary among patients but other characteristics include a soft high pitched voice partial webbing of fingers and toes palate deformations genital abnormalities eczema hyperactivity preference for concrete thinking over abstract language difficulties and aversion to crowds the pathogenesis of the disease is yet to be identified and no medical tests can definitively diagnose the disease the main method of diagnosis is through identification of facial phenotype since it was first described in 1965 by english physician victor dubowitz over 140 cases have been reported worldwide although the majority of cases have been reported from the united states germany and russia the disorder appears to affect both genders and all ethnicities equally
duchenne muscular dystrophy dmd is a severe type of muscular dystrophy the symptom of muscle weakness usually begin around the age of four in boys and worsens quickly typically muscle loss occurs first in the upper legs and pelvis followed by those of the upper arms this can result in trouble standing up most are unable to walk by the age of twelve affected muscles may look larger due to increased fat content scoliosis is also common some may have intellectual disability females with a single copy of the defective gene may show mild symptoms the disorder is x linked recessive about two thirds of cases are inherited from a person s parents while one third of cases are due to a new mutation it is caused by a mutation in the gene for the protein dystrophin dystrophin is important to maintain the muscle fiber cell membrane genetic testing can often make the diagnosis at birth those affected also have a high level of creatine kinase in their blood there is no cure for muscular dystrophy physical therapy braces and corrective surgery may help with some symptoms assisted ventilation may be required in those with weakness of breathing muscles medications used include steroids to slow muscle degeneration anticonvulsants to control seizures and some muscle activity and immunosuppressants to delay damage to dying muscle cells duchenne muscular dystrophy affects about one in 5 000 males at birth it is the most common type of muscular dystrophy the average life expectancy is 26 however with excellent care some may live into their 30 s or 40 s gene therapy as a treatment is in the early stages of study in humans
duck plague also known as duck viral enteritis is a worldwide disease caused by duck herpesvirus 1 anatid herpesvirus 1 of the family herpesviridae that causes acute disease with high mortality rates in flocks of ducks geese and swans it is spread both vertically and horizontally — through contaminated water and direct contact migratory waterfowl are a major factor in the spread of this disease as they are often asymptomatic carriers of disease the incubation period is three to seven days dve is not zoonotic
ducking is an audio effect commonly used in radio and pop music especially dance music in ducking the level of one audio signal is reduced by the presence of another signal in radio this can typically be achieved by lowering ducking the volume of a secondary audio track when the primary track starts and lifting the volume again when the primary track is finished a typical use of this effect in a daily radio production routine is for creating a voice over a foreign language original sound is dubbed and ducked by a professional speaker reading the translation ducking becomes active as soon as the translation starts in music the ducking effect is applied in more sophisticated ways where a signal s volume is delicately lowered by another signal s presence ducking here works through the use of a side chain gate in other words one track is made quieter the ducked track whenever another the ducking track gets louder this may be done with a gate with its ducking function engaged or by a dedicated ducker a typical application is to achieve an impression similar to the pumping effect the difference between ducking and side chain pumping is that in ducking the attenuation is by a specific range while side chain compression creates variable attenuation ducking may be used in place of mirrored equalization to combat masking for example with the bass guitar ducked under the kick drum resembling subtle side chain pumping a ducking system may be created where one track ducks another which ducks another and so on examples include portishead s biscuit used most often to turn down the music when the dj speaks ducking may be used to combat the muffling and distancing effect of reverb and delay the ducker is inserted into the reverb and delay line and keyed to a dry track to duck its own reverb and delay so that when the dry track exceeds the ducker s threshold by reaching a certain amplitude the reverb and delay are attenuated clear examples include céline dion s the power of love where the reverb and delay become audible when dion pauses and adele s cold shoulder
duct ectasia of the breast or mammary duct ectasia or plasma cell mastitis is a condition in which the lactiferous duct becomes blocked or clogged this is the most common cause of greenish discharge mammary duct ectasia can mimic breast cancer it is a disorder of peri or post menopausal age duct ectasia syndrome is a synonym for nonpuerperal mastitis but the term has also been occasionally used to describe special cases of fibrocystic diseases mastalgia or as a wastebasket definition of benign breast disease correlation of duct widening with the classical symptoms of duct ectasia syndrome is unclear however duct widening was recently very strongly correlated with noncyclic breast pain duct diameter is naturally variable subject to hormonal interactions duct ectasia syndrome in the classical meaning is associated with additional histological changes
ductal carcinoma is a type of tumor that primarily presents in the ducts of a gland types include mammary ductal carcinoma in situ invasive ductal carcinoma pancreatic ductal carcinoma
ductal carcinoma in situ dcis also known as intraductal carcinoma is a pre cancerous or non invasive cancerous lesion of the breast dcis is classified as stage 0 it rarely produces symptoms or a breast lump one can feel and is usually detected through screening mammography in dcis abnormal cells are found in the lining of one or more milk ducts in the breast in situ means in place and refers to the fact that the abnormal cells have not moved out of the mammary duct and into any of the surrounding tissues in the breast pre cancerous refers to the fact that it has not yet become an invasive cancer in some cases dcis may become invasive and spread to other tissues but there is no way of determining which lesions will remain stable without treatment and which will go on to become invasive dcis encompasses a wide spectrum of diseases ranging from low grade lesions that are not life threatening to high grade i e potentially highly aggressive lesions dcis has been classified according to the architectural pattern of the cells solid cribriform papillary and micropapillary tumor grade high intermediate and low grade and the presence or absence of comedo histology dcis can be detected on mammograms by examining tiny specks of calcium known as microcalcifications since suspicious groups of microcalcifications can appear even in the absence of dcis a biopsy may be necessary for diagnosis about 20 – 30 of those who do not receive treatment develop breast cancer it is the most common type of pre cancer in women there is some disagreement as to whether for statistical purposes it should be counted as a cancer some include dcis when calculating breast cancer statistics while others do not
in materials science ductility is a solid material s ability to deform under tensile stress this is often characterized by the material s ability to be stretched into a wire malleability a similar property is a material s ability to deform under compressive stress this is often characterized by the material s ability to form a thin sheet by hammering or rolling both of these mechanical properties are aspects of plasticity the extent to which a solid material can be plastically deformed without fracture also these material properties are dependent on temperature and pressure investigated by percy williams bridgman as part of his nobel prize winning work on high pressures ductility and malleability are not always coextensive – for instance while gold has high ductility and malleability lead has low ductility but high malleability the word ductility is sometimes used to encompass both types of plasticity
the duff reaction or hexamine aromatic formylation is a formylation reaction used in organic chemistry for the synthesis of benzaldehydes with hexamine as the formyl carbon source it is named after james cooper duff who was a chemist at the college of technology birmingham around 1920 – 1950 the electrophilic species in this electrophilic aromatic substitution reaction is the iminium ion ch 2 nr 2 the initial reaction product is an iminium which is hydrolyzed to the aldehyde see mechanism below the reaction requires strongly electron donating substituents on the aromatic ring such as in a phenol formylation occurs ortho to the electron donating substituent preferentially unless the ortho positions are blocked in which case the formylation occurs para examples are the synthesis of 3 5 di tert butylsalicylaldehyde duff reaction 3 5 di tert butylsalicylaldehyde and the synthesis of syringaldehyde duff reaction syringaldehyde
dukes disease named after clement dukes also known as fourth disease or filatov dukes disease after nil filatov is an exanthem it is distinguished from measles or forms of rubella though it was considered as a form of viral rash although dukes identified it as a separate entity it is thought not to be different from scarlet fever caused by exotoxin producing streptococcus pyogenes after keith powell proposed equating it with the condition currently known as staphylococcal scalded skin syndrome in 1979 it was never associated with a specific pathogen and the terminology is no longer in use however mysterious rash of unknown cause in school children often gives rise to the question whether it can be dukes disease
dunnigan type familial partial lipodystrophy abbreviated as fpld is a rare monogenic form of insulin resistance characterized by loss of subcutaneous fat from the extremities trunk and gluteal region fpld recapitulates the main metabolic attributes of the insulin resistance syndrome including central obesity hyperinsulinemia glucose intolerance and diabetes usually type 2 dyslipidemia hypertension and early endpoints of atherosclerosis it can also result in hepatic steatosis fpld results from mutations in lmna gene which is the gene that encodes nuclear lamins a and c
duodenal atresia also known as duodenojejunal atresia is the congenital absence or complete closure of a portion of the lumen of the duodenum it causes increased levels of amniotic fluid during pregnancy polyhydramnios and intestinal obstruction in newborn babies radiography shows a distended stomach and distended duodenum which are separated by the pyloric valve a finding described as the double bubble sign treatment includes suctioning out any fluid that is trapped in the stomach providing fluids intravenously and surgical repair of the intestinal closure
duodenal cancer is a cancer in the beginning section of the small intestine it is relatively rare compared to gastric cancer and colorectal cancer its histology is usually adenocarcinoma familial adenomatous polyposis fap gardner syndrome lynch syndrome muir torre syndrome celiac sprue puetz jeghers crohn s disease and juvenile polyposis syndrome are risk factors for developing this cancer the duodenum is the first part of the small intestine it is located between the stomach and the jejunum after foods combine with stomach acid they descend into the duodenum where they mix with bile from the gall bladder and digestive juices from the pancreas
duodenitis is inflammation of the duodenum it may persist acutely or chronically
on an ethernet connection a duplex mismatch is a condition where two connected devices operate in different duplex modes that is one operates in half duplex while the other one operates in full duplex the effect of a duplex mismatch is a link that operates inefficiently duplex mismatch may be caused by manually setting two connected network interfaces at different duplex modes or by connecting a device that performs autonegotiation to one that is manually set to a full duplex mode
duplicated ureter or duplex collecting system is a congenital condition in which the ureteric bud the embryological origin of the ureter splits or arises twice resulting in two ureters draining a single kidney it is the most common renal abnormality occurring in approximately 1 of the population the additional ureter may result in a ureterocele or an ectopic ureter
duplicity is the error committed when the charge known as a count on an indictment describes two different offences an indictment may contain more than one count but each count must allege only one offence so that the defendant and the jury can know precisely what offences he or she is accused of if a count is poorly drafted so that it alleges two offences it is said to be duplicitous a duplicitous count is defective and must be quashed by the judge unless the judge permits the count to be amended so that it only alleges one offence or is split into two counts if a duplicitous count is not noticed until after the defendant has been convicted on it the verdict may well be void this is a completely different situation from when two different counts each allege the same offence which is sometimes wrongly referred to as duplicity
dupuytren s contracture also known as dupuytren s disease or by the slang term viking disease is a flexion contracture of the hand due to a palmar fibromatosis in which the fingers bend towards the palm and cannot be fully extended straightened it is an inherited proliferative connective tissue disorder that involves the hand s palmar fascia it is named after baron guillaume dupuytren the surgeon who described an operation to correct the affliction dupuytren s contracture is treated with procedures to help straighten the fingers but this does not cure the underlying disease contractures often return or involve other fingers according to one study the ring finger is the finger most commonly affected followed by the middle and little fingers the thumb and index finger are only rarely affected dupuytren s contracture progresses slowly and is often accompanied by some aching and itching in patients with this condition the palmar fascia palmar aponeurosis thickens and shortens so that the tendons connected to the fingers cannot move freely the palmar fascia becomes hyperplastic and contracts incidence increases after age 40 at this age men are affected more often than women beyond 80 the gender distribution is about even in the united kingdom about 20 of people over 65 have some form of the disease
a dural arteriovenous fistula davf is an abnormal direct connection fistula between a meningeal artery and a meningeal vein or dural venous sinus in cases where there are multiple fistulas the related term dural arteriovenous malformation davm is used
a dust storm is a meteorological phenomenon common in arid and semi arid regions dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface particles are transported by saltation and suspension a process that moves soil from one place and deposits it in another drylands around north africa and the arabian peninsula are the main terrestrial sources of airborne dust also with some contributions from iran pakistan and india into the arabian sea and china s significant storms deposit dust in the pacific it has been argued that recently poor management of the earth s drylands such as neglecting the fallow system are increasing dust storms size and frequency from desert margins and changing both the local and global climate and also impacting local economies the term sandstorm is used most often in the context of desert sandstorms especially in the sahara desert or places where sand is a more prevalent soil type than dirt or rock when in addition to fine particles obscuring visibility a considerable amount of larger sand particles are blown closer to the surface the term dust storm is more likely to be used when finer particles are blown long distances especially when the dust storm affects urban areas
the dutch national flag problem dnf is a computer science programming problem proposed by edsger dijkstra the flag of the netherlands consists of three colors red white and blue given balls of these three colors arranged randomly in a line the actual number of balls does not matter the task is to arrange them such that all balls of the same color are together and their collective color groups are in the correct order the solution to this problem is of interest for designing sorting algorithms in particular variants of the quicksort algorithm that must be robust to repeated elements need a three way partitioning function that groups items less than a given key red equal to the key white and greater than the key blue several solutions exist that have varying performance characteristics tailored to sorting arrays with either small or large numbers of repeated elements
dwarfism occurs when an organism is short in stature from a medical condition that caused slow growth in humans dwarfism is sometimes defined as an adult height of less than 4 feet 10 inches 58 in 147 cm dwarfism can be caused by more than 300 medical conditions such that the symptoms of individuals with dwarfism vary greatly disproportionate dwarfism is characterized by one or more body parts being relatively large or small in comparison to those of an average sized adult with growth variations in specific areas in cases of proportionate dwarfism the body appears normally proportioned but is unusually small low muscle tone is common but intelligence and lifespan are usually normal treatment depends on the underlying cause those with bone growth disorders can sometimes be treated with surgery some hormone disorders can be treated with hormone replacement therapy before the child s growth plates fuse individual accommodations such as specialized furniture are often used by people with dwarfism many support groups provide services to aid individuals and the discrimination they may face in addition to the medical aspect of the condition there are also social aspects for a person with dwarfism height discrimination can lead to ridicule in childhood and discrimination in adulthood in the united kingdom united states canada australia and other english speaking countries some people with dwarfism prefer to be called little people historically the term midget was used to describe proportionate dwarfs however this term is now regarded as offensive by some
dwarfism in chickens is an inherited condition found in chickens consisting of a significant delayed growth resulting in adult individuals with a distinctive small size in comparison with normal specimens of the same breed or population the affected birds show no signs of dwarfism in the first weeks of age differences in size due to dwarfism appear slow and progressively along the growing stage poultry breeders begin to distinguish gradually dwarfs from normal birds by their shortest shanks and smallest body size depending on the breed most types of dwarfism in chickens begin to be recognized when the birds reach 8 – 10 weeks of age but classification is more precise when the chickens are five months old or more at this point differences between normal and dwarf sibs is evident in all males and in 98 of the females dwarfs chickens reach sexual maturity and reproduce normally dwarfism in chickens has been found to be controlled by several simple genetic factors some types are autosomic while others are sex linked but when poultry breeders make reference to dwarf chickens they usually refer implicitly to sex linked recessive dwarfism due to the recessive gene dw located on the z chromosome as sex linked dwarf broiler breeder hens can bring about normal sized broiler chickens sex linked recessive dwarfism found application in poultry industry since the last decades of the 20 th century these hens require less food and less housing space their feed intake do not need to be restricted they also have more tolerance to heat see so the use of sex linked dwarf broiler female parent stocks helps to save costs and to improve animal welfare and economic efficiency in european broiler industry see but in spite of the proven advantages of raising dwarf breeder hens their use is not generalized in broiler industry
in the military dwell time is the amount of time that service members spend in their home station between deployments to war zones or to dependent restricted tours dwell time is designed to allow service members a mental and physical break from combat and to give them time with their families it is an important component of long term military readiness
the dynamic convex hull problem is a class of dynamic problems in computational geometry the problem consists in the maintenance i e keeping track of the convex hull for the dynamically changing input data i e when input data elements may be inserted deleted or modified problems of this class may be distinguished by the types of the input data and the allowed types of modification of the input data
dynamic hyperinflation is a phenomenon that occurs when a new breath begins before the lung has reached the static equilibrium volume
dynamic problems in computational complexity theory are problems stated in terms of the changing input data in the most general form a problem in this category is usually stated as follows given a class of input objects find efficient algorithms and data structures to answer a certain query about a set of input objects each time the input data is modified i e objects are inserted or deleted problems of this class have the following measures of complexity space the amount of memory space required to store the data structure initialization time time required for the initial construction of the data structure insertion time time required for the update of the data structure when one more input element is added deletion time time required for the update of the data structure when an input element is deleted query time time required to answer a query other operations specific to the problem in question the overall set of computations for a dynamic problem is called a dynamic algorithm many algorithmic problems stated in terms of fixed input data called static problems in this context and solved by static algorithms have meaningful dynamic versions
in astrophysics dynamical friction sometimes called gravitational drag is loss of momentum and kinetic energy of moving bodies through gravitational interactions with surrounding matter in space it was first discussed in detail by subrahmanyan chandrasekhar in 1943
a dyotropic reaction from the greek dyo meaning two in organic chemistry is a type of organic reaction and more specifically a pericyclic valence isomerization in which two sigma bonds simultaneously migrate intramolecularly the reaction type is of some relevance to organic chemistry because it can explain how certain reactions occur and because it is a synthetic tool in the synthesis of organic molecules for example in total synthesis it was first described by manfred t reetz in 1971 dyotropic rearrangement in a type i reaction two migrating groups interchange their relative positions and a type ii reaction involves migration to new bonding sites without positional interchange
dysacusis is a hearing impairment characterized by difficulty in processing details of sound due to distortion in frequency or intensity but not primarily a loss of the ability to perceive sound the term is sometimes used to describe pain or discomfort due to sound a condition also known as auditory dysesthesia
in psychiatry dysaesthesia aethiopica was an alleged mental illness described by american physician samuel a cartwright in 1851 which proposed a theory for the cause of laziness among slaves today dysaesthesia aethiopica is considered an example of pseudoscience and part of the edifice of scientific racism
dysarthria is a motor speech disorder resulting from neurological injury of the motor component of the motor speech system and is characterized by poor articulation of phonemes cf aphasia a disorder of the content of language in other words it is a condition in which problems effectively occur with the muscles that help produce speech often making it very difficult to pronounce words it is unrelated to any problem with understanding cognitive language any of the speech subsystems respiration phonation resonance prosody and articulation can be affected leading to impairments in intelligibility audibility naturalness and efficiency of vocal communication dysarthria that has progressed to a total loss of speech is referred to as anarthria neurological injury due to damage in the central or peripheral nervous system may result in weakness paralysis or a lack of coordination of the motor speech system producing dysarthria these effects in turn hinder control over the tongue throat lips or lungs for example swallowing problems dysphagia are also often present in those with dysarthria dysarthria does not include speech disorders from structural abnormalities such as cleft palate and must not be confused with apraxia of speech which refers to problems in the planning and programming aspect of the motor speech system just as the term articulation can mean either speech or joint movement so is the combining form of arthr the same in the terms dysarthria dysarthrosis and arthropathy the term dysarthria is conventionally reserved for the speech problem and is not used to refer to arthropathy whereas dysarthrosis has both senses but usually refers to arthropathy cranial nerves that control the muscles relevant to dysarthria include the trigeminal nerve s motor branch v the facial nerve vii the glossopharyngeal nerve ix the vagus nerve x and the hypoglossal nerve xii the term is from ancient greek δυσ dys hard difficult bad and ἄρθρωσις arthrosis articulation
dysautonomia is a term for a group of diseases that include postural orthostatic tachycardia syndrome pots multiple system atrophy autonomic failure and autonomic neuropathy in these conditions the autonomic nervous system ans does not work properly dysautonomia is most often a type of neuropathy affecting the nerves that carry information from the brain and spinal cord to the heart bladder intestines sweat glands pupils and blood vessels although it has many causes not all of which classify as neuropathic the diagnosis is achieved through functional testing of the autonomic nervous system focusing on the organ system affected investigations may be performed to identify underlying disease processes that may have led to the development of symptoms or autonomic neuropathy symptomatic treatment is available for many symptoms associated with dysautonomia and some disease processes can be treated directly
dysbarism refers to medical conditions resulting from changes in ambient pressure various activities are associated with pressure changes scuba diving is the most frequently cited example but pressure changes also affect people who work in other pressurized environments for example caisson workers and people who move between different altitudes
dyscalculia ˌdɪskælˈkjuːli ə is difficulty in learning or comprehending arithmetic such as difficulty in understanding numbers learning how to manipulate numbers and learning facts in mathematics it is generally seen as a specific developmental disorder dyscalculia can occur in people from across the whole iq range often higher than average and involving difficulties with time measurement and spatial reasoning estimates of the prevalence of dyscalculia range between 3 and 6 of the population a quarter of children with dyscalculia have adhd mathematical disabilities can occur as the result of some types of brain injury in which case the proper term acalculia is to distinguish it from dyscalculia which is of innate genetic or developmental origin dyscalculia has been associated with female children who have turner syndrome people who have spina bifida and has also been associated with children who have adhd
dyschromatosis symmetrica hereditaria also known as reticulate acropigmentation of dohi and symmetrical dyschromatosis of the extremities is a rare autosomally inherited dermatosis it is characterized by progressively pigmented and depigmented macules often mixed in a reticulate pattern concentrated on the dorsal extremities it presents primarily in the japanese but has also been found to affect individuals from europe india and the caribbean
dyschromatosis universalis hereditaria is a rare genodermatosis characterized by reticulate hyper and hypo pigmentated macules in a generalized distribution both autosomal dominant and recessive inheritance have been reported with the disorder
dyschromia refers to an alteration of the color of the skin or nails hyperchromia can refer to hyperpigmentation and hypochromia can refer to hypopigmentation dyschromatoses involve both hyperpigmented and hypopigmented macules
dyschronometria is a condition of cerebellar dysfunction in which an individual cannot accurately estimate the amount of time that has passed i e distorted time perception it is associated with cerebellar ataxia when the cerebellum has been damaged and does not function to its fullest ability lesions to the cerebellum can cause dyssynergia dysmetria dysdiadochokinesia dysarthria and ataxia of stance and gait dyschronometria can result from autosomal dominant cerebellar ataxia adca
dysembryoplastic neuroepithelial tumour commonly abbreviated dnt or dnet is a type of brain tumor most commonly found in the temporal lobe dnts have been classified as benign tumours these are glioneuronal tumours comprising both glial and neuron cells and often have ties to focal cortical dysplasia varying subclasses of dnts have been presently identified with dispute existing in the field on how to properly group these classes the identification of possible genetic markers to these tumours is currently underway with dnts often causing epileptic seizures surgical removal is a common treatment providing high rates of success
dysentery is a type of gastroenteritis that results in diarrhea with blood other symptoms may include fever abdominal pain and a feeling of incomplete defecation it is caused by a number of types of infection such as bacteria viruses parasitic worms or protozoa the mechanism is an inflammatory disorder of the intestine especially of the colon
dysferlinopathy is an autosomal recessive neuromuscular disorder caused by a deficiency of functional dysferlin protein due to mutations in the dysferlin gene dysferlinopathy is characterized by progressive muscle wasting and is most often clinically diagnosed as limb girdle muscular dystrophy type 2 b lgmd 2 b or miyoshi muscular dystrophy 1 mmd 1 a type of distal muscular dystrophy depending on the initial pattern of muscle involvement at diagnosis dysferlinopathy is a rare disease the exact incidence of which has not yet been determined
a dysfunctional epiglottis is when the epiglottis the flap that separates the trachea from the esophagus stops working correctly this causes food to mistakenly go down the trachea when swallowing and also saliva this condition can get more serious over time
dysfunctional uterine bleeding dub or abnormal uterine bleeding aub is abnormal genital tract bleeding based in the uterus and found in the absence of demonstrable structural or organic disease it is usually due to hormonal disturbances reduced levels of progesterone cause low levels of prostaglandin f 2 alpha and cause menorrhagia abnormally heavy flow increased levels of tissue plasminogen activator tpa a fibrinolytic enzyme lead to more fibrinolysis diagnosis must be made by exclusion since organic pathology must first be ruled out aub can be classified as ovulatory or anovulatory depending on whether ovulation is occurring or not it is usually a menstrual disorder although abnormal bleeding from the uterus is possible outside of menstruation some sources state that the term dysfunctional implies a hormonal mechanism use of the term abnormal uterine bleeding is preferred in today s medicine
dysgammaglobulinemia is a type of immune disorder characterized by a reduction in some types of gamma globulins it is distinguished from hypogammaglobulinemia which is a reduction in all types of gamma globulins hyper igm syndrome can be considered a form of dysgammaglobulinemia because it results from a failure of transformation from igm production to production of other antibodies and so the condition can be interpreted as a reduction of the other types
a dysgerminoma is a type of germ cell tumor it usually is malignant and usually occurs in the ovary a tumor of the identical histology but not occurring in the ovary may be described by an alternate name seminoma in the testis or germinoma in the central nervous system or other parts of the body dysgerminoma accounts for less than 1 of ovarian tumors overall dysgerminoma usually occurs in adolescence and early adult life about 5 occur in pre pubertal children dysgerminoma is extremely rare after age 50 dysgerminoma occurs in both ovaries in 10 of patients and in a further 10 there is microscopic tumor in the other ovary abnormal gonads due to gonadal dysgenesis and androgen insensitivity syndrome have a high risk of developing a dysgerminoma most dysgerminomas are associated with elevated serum lactic dehydrogenase ldh which is sometimes used as a tumor marker
dysgraphia is a deficiency in the ability to write primarily handwriting but also coherence dysgraphia is a transcription disability meaning that it is a writing disorder associated with impaired handwriting orthographic coding orthography the storing process of written words and processing the letters in those words and finger sequencing the movement of muscles required to write it often overlaps with other learning disabilities such as speech impairment attention deficit disorder or developmental coordination disorder in the diagnostic and statistical manual of mental disorders dsm iv dysgraphia is characterized as a learning disability in the category of written expression when one ’ s writing skills are below those expected given a person ’ s age measured through intelligence and age appropriate education the dsm is not clear in whether or not writing refers only to the motor skills involved in writing or if it also includes orthographic skills and spelling the word dysgraphia comes from the greek words dys meaning impaired and γραφία graphía meaning writing by hand there are at least two stages in the act of writing the linguistic stage and the motor expressive praxic stage the linguistic stage involves the encoding of auditory and visual information into symbols for letters and written words this is mediated through the angular gyrus which provides the linguistic rules which guide writing the motor stage is where the expression of written words or graphemes is articulated this stage is mediated by exner ’ s writing area of the frontal lobe people with dysgraphia can often write on some level and may experience difficulty with other fine motor skills such as tying shoes however dysgraphia does not affect all fine motor skills people with dysgraphia often have unusual difficulty with handwriting and spelling which in turn can cause writing fatigue they may lack basic grammar and spelling skills for example having difficulties with the letters p q b and d and often will write the wrong word when trying to formulate their thoughts on paper the disorder generally emerges when the child is first introduced to writing adults teenagers and children alike are all subject to dysgraphia dysgraphia should be distinguished from agraphia which is an acquired loss of the ability to write resulting from brain injury stroke or progressive illness
dyshidrosis is a type of dermatitis that is characterized by itchy blisters on the palms of the hands and bottoms of the feet the blister are generally one to two millimeters in size and heal over three weeks redness is not usually present they however often recur repeated attacks may result in fissures and skin thickening the cause is unknown trigger may include allergens physical or mental stress frequent hand washing or metals diagnosis is typically based on what it looks like and the symptoms allergy testing and culture may be done to rule out other problems other conditions that produce similar symptoms include pustular psoriasis and scabies avoiding triggers may be useful as may a barrier cream treatment is generally with steroid cream high strength steroid creams may be required for the first week or two antihistamines may be used to help with the itch if this is not effective steroid pills tacrolimus or psoralen plus ultraviolet a puva may be tried about 1 in 2 000 people are affected in sweden males and females appear to be affected equally the first description was in 1873 the name comes from the word dyshidrotic meaning difficult sweating as problems with sweating was once believed to be the cause
dyskeratosis congenita dkc also called zinsser cole engman syndrome is a rare progressive congenital disorder with a highly variable phenotype the entity was classically defined by the triad of abnormal skin pigmentation nail dystrophy and leukoplakia of the oral mucosa but these components do not always occur dkc is characterized by short telomeres some of the manifestations resemble premature aging similar to progeria the disease initially mainly affects the skin but a major consequence is progressive bone marrow failure which occurs in over 80 causing early mortality
dyskinesia refers to a category of movement disorders that are characterized by involuntary muscle movements including movements similar to tics or chorea and diminished voluntary movements dyskinesia can be anything from a slight tremor of the hands to an uncontrollable movement of the upper body or lower extremities discoordination can also occur internally especially with the respiratory muscles and it often goes unrecognized dyskinesia is a symptom of several medical disorders that are distinguished by their underlying cause
dyslalia means difficulties in talking due to structural defects in speech organs it does not include speech impairment due to neurological or other factors
dyslexia also known as reading disorder is characterized by trouble with reading despite normal intelligence different people are affected to varying degrees problems may include difficulties in spelling words reading quickly writing words sounding out words in the head pronouncing words when reading aloud and understanding what one reads often these difficulties are first noticed at school when someone who previously could read loses their ability it is known as alexia the difficulties are involuntary and people with this disorder have a normal desire to learn dyslexia is believed to be caused by both genetic and environmental factors some cases run in families it often occurs in people with attention deficit hyperactivity disorder adhd and is associated with similar difficulties with numbers it may begin in adulthood as the result of a traumatic brain injury stroke or dementia the underlying mechanisms of dyslexia are problems within the brain s language processing dyslexia is diagnosed through a series of tests of memory spelling vision and reading skills dyslexia is separate from reading difficulties caused by hearing or vision problems or by insufficient teaching treatment involves adjusting teaching methods to meet the person s needs while not curing the underlying problem it may decrease the degree of symptoms treatments targeting vision are not effective dyslexia is the most common learning disability and occurs in all areas of the world it affects 3 – 7 of the population however up to 20 may have some degree of symptoms while dyslexia is more often diagnosed in men it has been suggested that it affects men and women equally some believe that dyslexia should be best considered as a different way of learning with both benefits and downsides
dyslipidemia is an abnormal amount of lipids e g triglycerides cholesterol and or fat phospholipids in the blood in developed countries most dyslipidemias are hyperlipidemias that is an elevation of lipids in the blood this is often due to diet and lifestyle prolonged elevation of insulin levels can also lead to dyslipidemia likewise increased levels of o glcnac transferase ogt may cause dyslipidemia
dysmelia from gr δυσ dys bad μέλ ος mél os limb eng suff ia is a congenital disorder of a limb resulting from a disturbance in embryonic development
dysmenorrhea also known as dysmenorrhoea painful periods or menstrual cramps is pain during menstruation it usually begins around the time that menstruation begins symptoms typically last less than three days the pain is usually in the pelvis or lower abdomen other symptoms may include back pain diarrhea or nausea in young women painful periods often occur without an underlying problem in older women it is more often due to an underlying issues such as uterine fibroids adenomyosis or endometriosis it is more common among those with heavy periods irregular periods whose periods started before twelve years of age or who have a low body weight a pelvic exam in those who are sexually active and ultrasound may be useful to help in diagnosis conditions that should be ruled out include ectopic pregnancy pelvic inflammatory disease interstitial cystitis and chronic pelvic pain dysmenorrhea occurs less often in those who exercise regularly and those who have children early in life treatment may include the use of a heating pad medications that may help include nsaids such as ibuprofen hormonal birth control and the iud with progestogen taking vitamin b or magnesium may help evidence for yoga acupuncture and massage is insufficient surgery may be useful if certain underlying problems are present dysmenorrhea is estimated to occur in 20 to 90 of women of reproductive age it is the most common menstrual disorder typically it starts within a year of the first menstrual period when there is no underlying cause often the pain improves with age or following having a child
dysmetria english wrong length refers to a lack of coordination of movement typified by the undershoot or overshoot of intended position with the hand arm leg or eye it is a type of ataxia it is sometimes described as an inability to judge distance or scale hypermetria and hypometria refer respectively to overshooting and undershooting the intended position
a dysmorphic feature is a difference of body structure it can be an isolated finding in an otherwise normal individual or it can be related to a congenital disorder genetic syndrome or birth defect dysmorphology is the study of dysmorphic features their origins and proper nomenclature one of the key challenges in identifying and describing dysmorphic features is the use and understanding of specific terms between different individuals clinical geneticists and pediatricians are usually those most closely involved with the identification and description of dysmorphic features as most are apparent during childhood dysmorphic features can vary from isolated mild anomalies such as clinodactyly or synophrys to severe congenital anomalies such as heart defects and holoprosencephaly in some cases dysmorphic features are part of a larger clinical picture sometimes known as a sequence syndrome or association recognizing the patterns of dysmorphic features is an important part of a geneticist s diagnostic process as many genetic disease present with a common collection of features there are several commercially available databases that allow clinicians to input their observed features in a patient to generate a differential diagnosis these databases are not infallible as they require on the clinician to provide their own experience particularly when the observed clinical features are general a male child with short stature and hypertelorism could have several different disorders as these findings are not highly specific however a finding such as 2 3 toe syndactyly is raises the index of suspicion for smith lemli opitz syndrome dysmorphic features are invariably present from birth although some are not immediately apparent upon visual inspection they can be divided into groups based on their origin including malformations abnormal development disruptions damage to previously normal tissue deformations damage caused by an outside physical force and dysplasias abnormal growth or organization within a tissue
dysmorphopsia in a broad sense is a condition which causes the person affected to be unable to correctly perceive objects it is a visual distortion used to denote a variant of metamorphopsia in which lines appear wavy these illusions may be restricted to certain visuals areas or may affect the entire visual field it has been associated with meningioma tumors and bilateral lateral occipital corital damage e g after carbon monoxide poisoning or drug abuse
dysorthography is a specific dysgraphic disorder of spelling which accompanies dyslexia by a direct consequence of the phonological disorder
dysosmia is a disorder described as any qualitative alteration or distortion of the perception of smell qualitative alterations differ from quantitative alterations which include anosmia and hyposmia dysosmia can be classified as either parosmia also called troposmia or phantosmia parosmia refers to a distortion in the perception of an odorant odorants smell different from what one remembers phantosmia refers to the perception of an odor when there ’ s no actual odorant present the etiology of dysosmia still remains a theory it is typically considered a neurological disorder and clinical associations with the disorder have been made most cases are described as idiopathic and the main antecedents related to parosmia are urtis head trauma and nasal and paranasal sinus disease dysosmia tends to go away on its own but there are options for treatment for patients that want immediate relief
a dysostosis is a disorder of the development of bone in particular affecting ossification examples include craniofacial dysostosis klippel feil syndrome and rubinstein taybi syndrome it is one of the two categories of constitutional disorders of bone the other being osteochondrodysplasia when the disorder involves the joint between two bones the term synostosis is often used
dyspareunia is painful sexual intercourse due to medical or psychological causes the pain can primarily be on the external surface of the genitalia or deeper in the pelvis upon deep pressure against the cervix it can affect a small portion of the vulva or vagina or be felt all over the surface understanding the duration location and nature of the pain is important in identifying the causes of the pain there are numerous physical psychological and social relationship causes that can contribute to pain during sexual encounters commonly multiple underlying causes contribute to the pain the pain can be acquired or congenital symptoms of dyspareunia may also occur after menopause diagnosis is typically by physical examination and a medical history treatment is determined by the underlying causes many women experience relief when physical causes are identified and treated even when the pain can be reproduced during a physical examination the possible role of psychological factors in either causing or maintaining the pain must be acknowledged and dealt with in treatment globally dyspareunia has been estimated to affect between 8 21 of women at some point in their lives
dysphagia lusoria or bayford autenrieth dysphagia is abnormal condition characterized by difficulty in swallowing caused by aberrant right subclavian artery it was discovered by david bayford in 1761 and first reported in a paper by the same in 1787
dysplastic nails are a cutaneous condition and may be a subtle finding of ridging flaking or poor growth of the nails or more diffuse with nearly complete loss of nails this condition may be seen in a number of syndromes including dyskeratosis congenita and nail – patella syndrome
a dysplastic nevus or atypical mole is a nevus mole whose appearance is different from that of common moles in 1992 the nih recommended that the term dysplastic nevus be avoided in favor of the term atypical mole an atypical mole may also be referred to as an atypical melanocytic nevus atypical nevus b k mole clark s nevus dysplastic melanocytic nevus or nevus with architectural disorder dysplastic nevi often grow to larger than ordinary moles and may have irregular and indistinct borders their color may not be uniform and may range from light pink to very dark brown they usually begin as flat but parts may raise above the skin surface see abcde and ugly duckling characteristics below dysplastic nevi can be found anywhere but are most common on the trunk in men and on the calves in women
dysplastic nevus syndrome also known as atypical mole syndrome ams familial atypical multiple mole – melanoma fammm syndrome familial melanoma syndrome and b k mole syndrome is a cutaneous condition described in certain families and characterized by unusual nevi and multiple inherited melanomas
dyssemia is a difficulty with receptive and or expressive nonverbal communication the word comes from the greek roots dys difficulty and semia signal the term was coined by psychologists marshall duke and stephen nowicki in their 1992 book helping the child who doesn t fit in to decipher the hidden dimensions of social rejection these difficulties go beyond problems with body language and motor skills dyssemic persons exhibit difficulties with the acquisition and use of nonverbal cues in interpersonal relationships a classic set of studies by albert mehrabian showed that in face to face interactions 55 percent of the emotional meaning of a message is expressed through facial postural and gestural means and 38 percent of the emotional meaning is transmitted through the tone of voice only seven percent of the emotional meaning is actually expressed with words dyssemia represents the social dysfunction aspect of nonverbal learning disorder
dysthymia dɪsˈθaɪmiə dis thy mee ə from ancient greek δυσθυμία bad state of mind sometimes also called neurotic depression dysthymic disorder or chronic depression is a mood disorder consisting of the same cognitive and physical problems as in depression with less severe but longer lasting symptoms the concept was coined by robert spitzer as a replacement for the term depressive personality in the late 1970 s according to the fourth edition of the diagnostic and statistical manual of mental disorders published in 1994 dsm iv dysthymia is a serious state of chronic depression which persists for at least two years one year for children and adolescents dysthymia is less acute and severe than major depressive disorder as dysthymia is a chronic disorder sufferers may experience symptoms for many years before it is diagnosed if diagnosis occurs at all as a result they may believe that depression is a part of their character so they may not even discuss their symptoms with doctors family members or friends dysthymia often co occurs with other mental disorders a double depression is the occurrence of episodes of major depression in addition to dysthymia switching between periods of dysthymic moods and periods of hypomanic moods is indicative of cyclothymia which is a mild variant of bipolar disorder in the dsm 5 dysthymia is replaced by persistent depressive disorder pdd this new condition includes both chronic major depressive disorder and the previous dysthymic disorder the reason for this change is that there was no evidence for meaningful differences between these two conditions
dystonia is a neurological movement disorder syndrome in which sustained or repetitive muscle contractions result in twisting and repetitive movements or abnormal fixed postures the movements may resemble a tremor dystonia is often intensified or exacerbated by physical activity and symptoms may progress into adjacent muscles the disorder may be hereditary or caused by other factors such as birth related or other physical trauma infection poisoning e g lead poisoning or reaction to pharmaceutical drugs particularly neuroleptics treatment must be highly customized to the needs of the individual and may include oral medications chemodenervation botulinum neurotoxin injections physical therapy and or other supportive therapies and or surgical procedures such as deep brain stimulation
dystrophic calcification dc is the calcification occurring in degenerated or necrotic tissue as in hyalinized scars degenerated foci in leiomyomas and caseous nodules this occurs as a reaction to tissue damage including as a consequence of medical device implantation dystrophic calcification can occur even if the amount of calcium in the blood is not elevated a systemic mineral imbalance would elevate calcium levels in the blood and all tissues and cause metastatic calcification basophilic calcium salt deposits aggregate first in the mitochondria and progressively throughout the cell these calcifications are an indication of previous microscopic cell injury it occurs in areas of cell necrosis in which activated phosphatases bind calcium ions to phospholipids in the membrane calcification can occur in dead or degenerated tissue
dystrophic calcinosis cutis is a cutaneous condition characterized by calcification of the skin resulting from the deposition of calcium and phosphorus and occurs in a preexisting skin lesion of inflammatory process
déjà vu ˌdeɪʒɑː ˈvuː french pronunciation ​ de ʒa vy from french literally already seen is the phenomenon of having the strong sensation that an event or experience currently being experienced has already been experienced in the past déjà vu is a feeling of familiarity and déjà vécu the feeling of having already lived through something is a feeling of recollection scientific approaches reject the explanation of déjà vu as precognition or prophecy but rather explain it as an anomaly of memory which creates a distinct impression that an experience is being recalled this explanation is supported by the fact that the sense of recollection at the time is strong in most cases but that the circumstances of the previous experience when where and how the earlier experience occurred are uncertain or believed to be impossible two types of déjà vu are suggested to exist the pathological type of déjà vu usually associated with epilepsy and the non pathological which is a characteristic of healthy people and psychological phenomena a 2004 survey concluded that approximately two thirds of the population have had déjà vu experiences other studies confirm that déjà vu is a common experience in healthy individuals with between 31 and 96 of individuals reporting it déjà vu experiences that are unusually prolonged or frequent or in association with other symptoms such as hallucinations may be an indicator of neurological or psychiatric illness
the e 1 cb elimination reaction is a type of elimination reaction which occurs under basic conditions where a particularly poor leaving group such as oh or or and an acidic hydrogen eliminate to form an additional bond e 1 cb is a two step process first a base abstracts the most acidic proton to generate a stabilized anion the lone pair of electrons on the anion then moves to the neighboring atom thus expelling the leaving group and forming double or triple bond the name of the mechanism e 1 cb stands for elimination unimolecular conjugate base elimination refers to the fact that the mechanism is an elimination reaction and will lose two substituents unimolecular refers to the fact that the rate determining step of this reaction only involves one molecular entity finally conjugate base refers to the formation of the carbanion intermediate which is the conjugate base of the starting material
east syndrome is a syndrome consisting of epilepsy ataxia a movement disorder sensorineural deafness deafness because of problems with the hearing nerve and salt wasting renal tubulopathy salt loss caused by kidney problems the tubulopathy renal tubule abnormalities in this condition predispose to hypokalemic low potassium metabolic alkalosis with normal blood pressure hypomagnesemia low blood levels of magnesium may also be present east syndrome is also called sesame syndrome as a syndrome of seizures sensorineural deafness ataxia intellectual disability mental retardation and electrolyte imbalances it is an autosomal recessive genetic disorder caused by mutations in the kcnj 10 gene as discovered by bockenhauer and co workers the kcnj 10 gene encodes the k channel kir 4 allowing k to flow into a cell rather than out and is present in the brain ear and kidney
eem syndrome or ectodermal dysplasia ectrodactyly and macular dystrophy syndrome is an autosomal recessive congenital malformation disorder affecting tissues associated with the ectoderm skin hair nails teeth and also the hands feet and eyes
the elsa moot court competition emc ² on wto law is a simulated hearing in the world trade organization wto dispute settlement system participating teams represent both the complainant and respondent parties to the case by presenting oral submissions in front of a panel emc ² panels consist of wto law experts and are referred to as panellist the competition provides students with the opportunity to put theory into practice thereby completing formal legal education the wto which was established in 1995 is based on the old general agreement on tariffs and trade and creates a system for efficiently regulating international trade despite the controversies the present structure looks to promote and enhance international trade for years to come the aim of the competition is both to encourage further development on the subject matter in the curriculum of academic institutions and also to contribute to the ongoing discussion about globalisation in the context of the wto agreements
in computational complexity theory eqp sometimes called qp which stands for exact quantum polynomial time is the class of decision problems solvable by a quantum computer which outputs the correct answer with probability 1 and runs in polynomial time it is the quantum analogue of the complexity class p in other words there is an algorithm for a quantum computer a quantum algorithm that solves the decision problem exactly and is guaranteed to run in polynomial time
erdl pattern also known as leaf pattern is a camouflage pattern developed by the united states army at its engineer research development laboratories erdl in 1948 it was not issued to elite reconnaissance and special operations units until early 1967 during the vietnam war the pattern consists of four colors printed in an interlocking pattern
the eurion constellation also known as omron rings or doughnuts is a pattern of symbols incorporated into a number of banknote designs worldwide since about 1996 it is added to help imaging software detect the presence of a banknote in a digital image such software can then block the user from reproducing banknotes to prevent counterfeiting using colour photocopiers research shows that the eurion constellation is used for colour photocopiers but probably not used in computer software it has been reported that adobe photoshop will not allow editing of an image of a banknote but this is believed due to a different unknown digital watermark rather than the eurion constellation
eagle syndrome also termed stylohyoid syndrome styloid syndrome styloid stylohyoid syndrome or styloid – carotid artery syndrome is a rare condition characterized by sudden sharp nerve like pain in the jaw bone and joint back of the throat and base of the tongue triggered by swallowing moving the jaw or turning the neck named for the doctor who first described it in 1937 the condition is caused by an elongated or misshapen styloid process the slender pointed piece of bone just below the ear and or calcification of the stylohyoid ligament which interferes with the functioning of neighboring regions in the body giving rise to pain
eales disease is a type of obliterative vasculopathy also known as angiopathia retinae juvenilis periphlebitis retinae primary perivasculitis of the retina is an ocular disease characterized by inflammation and possible blockage of retinal blood vessels abnormal growth of new blood vessels neovascularization and recurrent retinal and vitreal hemorrhages eales disease with a characteristic clinical picture fluorescein angiographic finding and natural course and is considered a specific disease entity
ear disease is a subfield of otolaryngology addressing the pathology of the ear two of the major categories are otitis and hearing disorders however not all hearing disorders are due to structures of the ear
ear eczema is an eczema of the ear that may involve the helix postauricular fold and external auditory canal with the most frequently affected site being the external canal where it is often a manifestation of seborrheic dermatitis or allergic contact dermatitis
ear pain also known as otalgia or earache is pain in the ear primary ear pain is pain that originates inside the ear referred ear pain is pain that originates from outside the ear ear pain is not always associated with ear disease it may be caused by several other conditions such as impacted teeth sinus disease inflamed tonsils infections in the nose and pharynx throat cancer and occasionally as a sensory aura that precedes a migraine
early onset alzheimer s disease also called early onset alzheimer s or early onset ad is alzheimer s disease diagnosed before the age of 65 it is an uncommon form of alzheimer s accounting for only 5 10 of all alzheimer s cases approximately 13 of the cases of early onset alzheimer s are where a genetic predisposition leads to the disease the other incidences of early onset alzheimer s however share the same traits as the late onset form of alzheimer s disease and little is understood about how it starts non familial early onset alzheimer s can develop in people who are in their thirties or forties but that is extremely rare the majority of people with early onset alzheimer s are in their fifties or early sixties
the early 2000 s recession was a decline in economic activity which mainly occurred in developed countries the recession affected the european union during 2000 and 2001 and the united states in 2002 and 2003 the uk canada and australia avoided the recession while russia a nation that did not experience prosperity during the 1990 s in fact began to recover from said situation japan s 1990 s recession continued this recession was predicted by economists because the boom of the 1990 s accompanied by both low inflation and low unemployment slowed in some parts of east asia during the 1997 asian financial crisis the recession in industrialized countries wasn t as significant as either of the two previous worldwide recessions some economists in the united states object to characterizing it as a recession since there were no two consecutive quarters of negative growth
the early paleoeskimo is one of three distinct periods of human occupation recognized by archaeologists in the eastern north american arctic the others being the late paleoeskimo and the thule dates for these occupations vary according to specific geographic region and cultural historical perspective but it is generally agreed that the first the early paleoeskimo spans roughly 4500 before present bp to 28 2300 bp
early childhood caries ecc also known as baby bottle caries baby bottle tooth decay and bottle rot is a disease characterized by severe decay in the teeth of infants or young children early childhood caries is a very common bacterial infection it occurs in all areas of the world in the us rates are highest in minority and rural populations at times infecting over 70 of the children ecc occurs more often in children from the lower end of the socioeconomic scale a large body of scientific evidence indicates that ecc is an infectious and transmissible disease with streptococcus mutans the primary microbiological agent in the disease the disease process begins with the transmission of the bacteria to the child usually from the primary caretaker caretakers with untreated dental disease present a very high risk to their children
early myoclonic encephalopathy eme is an epilepsy syndrome where myoclonic seizures develop in the neonatal period after several months the seizure pattern may develop to infantile spasms west syndrome various genetic and metabolic disorders are responsible the seizures are resistant to treatment the neurology is very abnormal and patients often do not live beyond one year
an earnings surprise or unexpected earnings in accounting is the difference between the reported earnings and the expected earnings of an entity measures of a firm s expected earnings in turn include analysts forecasts of the firm s profit and mathematical models of expected earnings based on the earnings of previous accounting periods
the earth pyramids in south tyrol are a special natural phenomenon that comes about in particular terrain usually after a landslide or an unhinging of the earth the main cause of the formation of earth pyramids is the continuous alternation of periods of torrential rain anddrought these phenomena in particularly friable terrain over the years increasingly erode the ground and form such earth pyramids usually the pyramids are formed in terrain very well sheltered from wind so that they cannot be damaged by it moreover the life of the earth pyramids is strongly dependent on the climate which reigns during the time in which it is shaped by the rock that covers it there are several earth pyramids that can be safely visited among the most famous and admired thefollowing are the most outstanding the earth pyramids of ritten a plateau above bolzano which are divided into three distinct groups near the villages klobenstein oberbozen and unterinn the earth pyramids of platten near percha in the puster valley other less famous earth pyramids are in terenten puster valley in mölten in jenesien near bolzano in the hinterland of merano in tirol kuens and riffian in karneid and steinegg one of its hamlets in neustift in the rigger valley in segonzano in the cembra valley
earth tide also known as body tide or bodily tides or land tides is the displacement of the solid earth s surface caused by the gravity of the moon and sun its main component has meter level amplitude at periods of about 12 hours and longer the largest body tide constituents are semi diurnal but there are also significant diurnal semi annual and fortnightly contributions though the gravitational forcing causing earth tides and ocean tides is the same the responses are quite different
an earthquake light is an unusual luminous aerial phenomenon that reportedly appears in the sky at or near areas of tectonic stress seismic activity or volcanic eruptions skeptics maintain that there is no evidence of earthquake lights
earwax also known as cerumen is a yellowish waxy substance secreted in the ear canal of humans and other mammals it protects the skin of the human ear canal assists in cleaning and lubrication and also provides some protection from bacteria fungi insects and water earwax consists of shed skin cells hair and the secretions of the ceruminous and sebaceous glands of the outside ear canal major components of earwax are long chain fatty acids both saturated and unsaturated alcohols squalene and cholesterol excess or compacted cerumen can press against the eardrum or block the outside ear canal or hearing aids potentially causing hearing loss
in sewing and patternmaking ease is the amount of room a garment allows the wearer beyond the measurements of their body for example if a man has a 40 inch chest measurement a jacket with a 40 inch chest would be very tight and would constrict movement an ease of 3 or 4 inches might be added to the pattern making a 43 44 inch chest or more to enhance comfort or style ease is not generally included in sizing measurements to use the example again a man with a 40 inch chest will likely buy a jacket advertised as size 40 but the actual measurements of the garment will almost always be somewhat larger ease is most important for woven garments cut on the straight or crossgrain allowing little or no stretch a sloper pattern or block pattern is a simple pattern with very little or no ease made for the purpose of fitting the body accurately from which more finished or stylized patterns may be developed
east coast fever theileriosis is a disease of cattle sheep and goats caused by the protozoan parasite theileria parva the term excludes diseases caused by other theileria such as tropical theileriosis also known as mediterranean theileriosis caused by t annulata and human theileriosis caused by t microti
the east – west schism also called the great schism and the schism of 1054 was the break of communion between what are now the eastern orthodox and catholic churches which has lasted since the 11 th century it is not to be confused with the western schism which is also sometimes called the great schism the ecclesiastical differences and theological disputes between the greek east and latin west pre dated the formal rupture that occurred in 1054 prominent among these were the issues of the source of the holy spirit whether leavened or unleavened bread should be used in the eucharist the bishop of rome s claim to universal jurisdiction and the place of the see of constantinople in relation to the pentarchy in 1053 the first step was taken in the process which led to formal schism the ecumenical patriarch of constantinople michael i cerularius ordered the closure of all latin churches in constantinople in response to the greek churches in southern italy having been forced to either close or conform to latin practices according to the historian j b bury cerularius purpose in closing the latin churches was to cut short any attempt at conciliation in 1054 the papal legate sent by leo ix traveled to constantinople for purposes that included refusing to cerularius the title of ecumenical patriarch and insisting that he recognize the pope s claim to be the head of all the churches the main purpose of the papal legation was to seek help from the byzantine emperor in view of the norman conquest of southern italy and to deal with recent attacks by leo of ohrid against the use of unleavened bread and other western customs attacks that had the support of cerularius historian axel bayer says the legation was sent in response to two letters one from the emperor seeking assistance in arranging a common military campaign by the eastern and western empires against the normans and the other from cerularius on the refusal of cerularius to accept the demand the leader of the legation cardinal humbert of silva candida o s b excommunicated him and in return cerularius excommunicated humbert and the other legates this was only the first act in a centuries long process that eventually became a complete schism the validity of the western legates act is doubtful since leo had died and cerularius excommunication applied only to the legates personally still the church split along doctrinal theological linguistic political and geographical lines and the fundamental breach has never been healed with each side sometimes accusing the other of having fallen into heresy and of having initiated the division the crusades the massacre of the latins in 1182 the west s retaliation in the sacking of thessalonica in 1185 the capture and siege of constantinople in 1204 and the imposition of latin patriarchs made reconciliation more difficult establishing latin hierarchies in the crusader states meant that there were two rival claimants to each of the patriarchal sees of antioch constantinople and jerusalem making the existence of schism clear several attempts at reconciliation did not bear fruit in 1965 pope paul vi and the ecumenical patriarch of constantinople athenagoras i nullified the anathemas of 1054 although this nullification of measures taken against a few individuals was essentially a goodwill gesture and did not constitute any sort of reunion contacts between the two sides continue every year a delegation from each joins in the other s celebration of its patronal feast saints peter and paul 29 june for rome and saint andrew 30 november for constantinople and there have been a number of visits by the head of each to the other the efforts of the ecumenical patriarchs towards reconciliation with the catholic church have often been the target of sharp criticism from some fellow orthodox
eating disorders are mental disorders defined by abnormal eating habits that negatively affect a person s physical or mental health they include binge eating disorder where people eat a large amount in a short period of time anorexia nervosa where people eat very little and thus have a low body weight bulimia nervosa where people eat a lot and then try to rid themselves of the food pica where people eat non food items rumination disorder where people regurgitate food avoidant restrictive food intake disorder where people have a lack of interest in food and a group of other specified feeding or eating disorders anxiety disorders depression and substance abuse are common among people with eating disorders these disorders do not include obesity the cause of eating disorders is not clear both biological and environmental factors appear to play a role cultural idealization of thinness is believed to contribute eating disorders affect about 12 percent of dancers those who have experienced sexual abuse are also more likely to develop eating disorders some disorders such as pica and rumination disorder occur more often in people with intellectual disabilities only one eating disorder can be diagnosed at a given time treatment can be effective for many eating disorders this typically involves counselling a proper diet a normal amount of exercise and the reduction of efforts to eliminate food hospitalization is occasionally needed medications may be used to help with some of the associated symptoms at five years about 70 of people with anorexia and 50 of people with bulimia recover recovery from binge eating disorder is less clear and estimated at 20 to 60 both anorexia and bulimia increase the risk of death in the developed world binge eating disorder affects about 1 6 of women and 0 8 of men in a given year anorexia affects about 0 4 and bulimia affects about 1 3 of young women in a given year during the entire life up to 4 of women have anorexia 2 have bulimia and 2 have binge eating disorder anorexia and bulimia occur nearly ten times more often in females than males typically they begin in late childhood or early adulthood rates of other eating disorders are not clear rates of eating disorders appear to be lower in less developed countries
eating disorder not otherwise specified ednos is an eating disorder that does not meet the criteria for anorexia nervosa bulimia nervosa or binge eating individuals with ednos usually fall into one of three groups sub threshold symptoms of anorexia or bulimia mixed features of both disorders or extremely atypical eating behaviors that are not characterized by either of the other established disorders people with ednos have similar symptoms and behaviors to those with anorexia and bulimia and can face the same dangerous risks ednos is the most prevalent eating disorder about 60 of adults treated for eating disorders are diagnosed with ednos ednos occurs in all genders
eating mucus is the act of extracting nasal mucus with one s finger rhinotillexis and the succeeding action of ingesting the mucus from the nose picking mucophagy nasal mucus is also termed as boogers snot bogeys dried nasal mucus mucus secretion and other related terms including comerse los mocos to eat one s snot mucophagy is a common behavior in children however this action is condemned in most cultures and societies which try to prevent development of the habit and attempt to break it if already established mucophagy is a source of mockery and entertainment in the media thus confirming the social scorn previously mentioned
ebola virus disease evd also known as ebola hemorrhagic fever ehf or simply ebola is a viral hemorrhagic fever of humans and other primates caused by ebolaviruses signs and symptoms typically start between two days and three weeks after contracting the virus with a fever sore throat muscular pain and headaches then vomiting diarrhea and rash usually follow along with decreased function of the liver and kidneys at this time some people begin to bleed both internally and externally the disease has a high risk of death killing between 25 and 90 percent of those infected with an average of about 50 percent this is often due to low blood pressure from fluid loss and typically follows six to sixteen days after symptoms appear the virus spreads by direct contact with body fluids such as blood of an infected human or other animals this may also occur through contact with an item recently contaminated with bodily fluids spread of the disease through the air between primates including humans has not been documented in either laboratory or natural conditions semen or breast milk of a person after recovery from evd may carry the virus for several weeks to months fruit bats are believed to be the normal carrier in nature able to spread the virus without being affected by it other diseases such as malaria cholera typhoid fever meningitis and other viral hemorrhagic fevers may resemble evd blood samples are tested for viral rna viral antibodies or for the virus itself to confirm the diagnosis control of outbreaks requires coordinated medical services alongside a certain level of community engagement the medical services include rapid detection of cases of disease contact tracing of those who have come into contact with infected individuals quick access to laboratory services proper healthcare for those who are infected and proper disposal of the dead through cremation or burial samples of body fluids and tissues from people with the disease should be handled with special caution prevention includes limiting the spread of disease from infected animals to humans this may be done by handling potentially infected bushmeat only while wearing protective clothing and by thoroughly cooking it before eating it it also includes wearing proper protective clothing and washing hands when around a person with the disease no specific treatment or vaccine for the virus is available although a number of potential treatments are being studied supportive efforts however improve outcomes this includes either oral rehydration therapy drinking slightly sweetened and salty water or giving intravenous fluids as well as treating symptoms the disease was first identified in 1976 in two simultaneous outbreaks one in nzara and the other in yambuku a village near the ebola river from which the disease takes its name evd outbreaks occur intermittently in tropical regions of sub saharan africa between 1976 and 2013 the world health organization reports a total of 24 outbreaks involving 1 716 cases the largest outbreak to date was the epidemic in west africa which occurred from december 2013 to january 2016 with section ebola virus epidemic in west africa cases cases and section ebola virus epidemic in west africa deaths deaths section ebola virus epidemic in west africa caserefs it was declared no longer an emergency on 29 march 2016
ebola virus disease or simply ebola is a disease of humans and other primates caused by ebolaviruses there is no cure or specific treatment that is currently approved treatment is primarily supportive in nature
ebstein s anomaly is a congenital heart defect in which the septal and posterior leaflets of the tricuspid valve are displaced towards the apex of the right ventricle of the heart
an ecchondroma is a type of chondroma that is subperiosteal a proliferation is known as ecchondrosis
an ecchymosis is a subcutaneous spot of bleeding from extravasation of blood with diameter larger than 1 centimetre 0 39 in it is similar to and sometimes indistinguishable from a hematoma commonly called a bruise though the terms are not interchangeable in careful usage specifically bruises are caused by trauma whereas ecchymoses which are the same as the spots of purpura except larger are not necessarily caused by trauma often being caused by pathophysiologic cell function a broader definition of ecchymosis is the escape of blood into the tissues from ruptured blood vessels the term also applies to the subcutaneous discoloration resulting from seepage of blood within the contused tissue
eccrine carcinoma also known as a syringoid carcinoma is a rare cutaneous condition characterized by a plaque or nodule on the scalp trunk or extremities
eccrine mucinosis is a cutaneous condition characterized by mucinosis and described in hiv infected patients
an eccrine nevus is an extremely rare cutaneous condition that histologically is characterized by an increase in size or number of eccrine secretory coils
echinococcosis also called hydatid disease hydatidosis or echinococcal disease is a parasitic disease of tapeworms of the echinococcus type the two main types of the disease are cystic echinococcosis and alveolar echinococcosis less common forms include polycystic echinococcosis and unicystic echinococcosis the disease often starts without symptoms and this may last for years the symptoms and signs that occur depend on the cyst s location and size alveolar disease usually begins in the liver but can spread to other parts of the body such as the lungs or brain when the liver is affected the person may have abdominal pain weight loss and turn slightly yellow from jaundice lung disease may cause pain in the chest shortness of breath and coughing the disease is spread when food or water that contains the eggs of the parasite is eaten or by close contact with an infected animal the eggs are released in the stool of meat eating animals that are infected by the parasite commonly infected animals include dogs foxes and wolves for these animals to become infected they must eat the organs of an animal that contains the cysts such as sheep or rodents the type of disease that occurs in people depends on the type of echinococcus causing the infection it is a type of worm infection and is a neglected tropical disease diagnosis is usually by ultrasound though computer tomography ct or magnetic resonance imaging mri may also be used blood tests looking for antibodies against the parasite may be helpful as may biopsy prevention of cystic disease is by treating dogs that may carry the disease and vaccination of sheep treatment is often difficult the cystic disease may be drained through the skin followed by medication sometimes this type of disease is just watched the alveolar type often needs surgery followed by medications the medication used is albendazole which may be needed for years the alveolar disease may result in death the disease occurs in most areas of the world and currently affects about one million people in some areas of south america africa and asia up to 10 of the certain populations are affected in 2010 it caused about 1200 deaths down from 2000 in 1990 the economic cost of the disease is estimated to be around 3 billion usd a year it is classified as a neglected tropical disease and belongs to the group of diseases known as helminthiasis it can affect other animals such as pigs cows and horses
echo park colorado is a remote river bottom surrounded by canyon walls on the green river just downstream from the confluence with the yampa river and across the stream from the dramatic southern end of steamboat rock in dinosaur national monument it was first mapped and given its name by the powell geographic expedition in 1869 a proposed dam at echo park turned into a nationwide environmental controversy in the early 1950 s the sierra club and other conservationist groups helped forge a compromise in congress that eliminated the echo park dam from the colorado river storage project act of 1956
echogenicity misspelled sometimes as echogenecity is the ability to bounce an echo e g return the signal in ultrasound examinations in other words echogenicity is higher when the surface bouncing the sound echo reflects increased sound waves tissues that have higher echogenicity are called hyperechogenic and are usually represented with lighter colors on images in medical ultrasonography in contrast tissues with lower echogenicity are called hypoechogenic and are usually represented with darker colors areas that lack echogenicity are called anechogenic and are usually displayed as completely dark
echolalia also known as echologia or echophrasia is defined as the unsolicited repetition of vocalizations made by another person by the same person is called palilalia in its profound form it is automatic and effortless it is one of the echophenomena closely related to echopraxia the automatic repetition of movements made by another person both are subsets of imitative behavior whereby sounds or actions are imitated without explicit awareness echolalia may be an immediate reaction to a stimulus or may be delayed the word echolalia is derived from the greek ἠχώ meaning echo or to repeat and λαλιά laliá meaning speech or talk of onomatopoeic origin from the verb λαλέω laléo meaning to talk
the echoplex is a tape delay effect first made in 1959 designed by mike battle the echoplex set a standard for the effect in the 1960 s — it is still regarded as the standard by which everything else is measured it was used by some of the most notable guitar players of the era original echoplexes are highly sought after
eclampsia is the onset of seizures convulsions in a woman with pre eclampsia pre eclampsia is a disorder of pregnancy in which there is high blood pressure and either large amounts of protein in the urine or other organ dysfunction onset may be before during or after delivery most often it is during the second half of pregnancy the seizures are of the tonic – clonic type and typically last about a minute following the seizure there is typically either a period of confusion or coma complications include aspiration pneumonia cerebral hemorrhage kidney failure and cardiac arrest preeclampsia and eclampsia are part of a larger group of conditions known as hypertensive disorders of pregnancy recommendations for prevention include aspirin in those at high risk calcium supplementation in areas with low intake and treatment of prior hypertension with medications exercise during pregnancy may also be useful the use of intravenous or intramuscular magnesium sulfate improves outcomes in those with eclampsia and is generally safe this is true in both the developed and developing world breathing may need to be supported other treatments may include blood pressure medications such as hydralazine and emergency delivery of the baby either vaginally or by cesarean section pre eclampsia is estimated to affect about 5 of deliveries while eclampsia affects about 1 4 of deliveries in the developed world rates are about 1 in 2 000 deliveries due to improved medical care hypertensive disorders of pregnancy are one of the most common causes of death in pregnancy they resulted in 29 000 deaths in 2013 – down from 37 000 deaths in 1990 around one percent of women with eclampsia die the word eclampsia is from the greek term for lightning the first known description of the condition was by hippocrates in the 5 th century bce
ecocide is the extensive damage to destruction of or loss of ecosystem s of a given territory whether by human agency or by other to such an extent that peaceful enjoyment by the inhabitants of that territory has been or will be severely diminished
ecological competence is the ability of an organism often a pathogen to survive and compete in new habitats in the case of plant pathogens it is also their ability to survive between growing seasons for example peanut clump virus can survive in the spores of its fungal vector until a new growing season begins and it can proceed to infect its primary host again if a pathogen does not have ecological competence it is likely to become extinct
ecological inheritance is the physical consequence of niche construction passed down through generations through ancestral organisms this differs from genetic inheritance because it depends on each generation to sustain the efforts towards environmental modifications of previous generations
ecological light pollution is the effect of artificial light on individual organisms and on the structure of ecosystems as a whole the effect that artificial light has upon organisms is highly variable and ranges from beneficial e g increased ability for predator species to observe prey to immediately fatal e g moths that are attracted to incandescent lanterns and are killed by the heat it is also possible for light at night to be both beneficial and damaging for a species as an example humans benefit from using indoor artificial light to extend the time available for work and play but the light disrupts the human circadian rhythm and the resulting stress is damaging to health through the various effects that light pollution has on individual species the ecology of regions is affected in the case where two species occupy an identical niche the population frequency of each species may be changed by the introduction of artificial light if they are not equally affected by light at night for example some species of spiders avoid lit areas while other species are happy to build their spider web directly on a lamp post since lamp posts attract many flying insects the spiders that don t mind light gain an advantage over the spiders that avoid it and consequently become more common changes in these species frequencies can then have knock on effects as the interactions between these species and others in the ecosystem are affected and food webs are altered these ripple effects can eventually affect even diurnal plants and animals as an example changes in the activity of night active insects can change the survival rates of night blooming plants which may provide food or shelter for diurnal animals the introduction of artificial light at night is one of the most drastic anthropogenic changes to the earth comparable to toxic pollution land use change and climate change due to increases in the concentration of green house gases
ecological literacy also referred to as ecoliteracy is the ability to understand the natural systems that make life on earth possible to be ecoliterate means understanding the principles of organization of ecological communities i e ecosystems and using those principles for creating sustainable human communities the term was coined by american educator david w orr and physicist fritjof capra in the 1990 s thereby a new value entered education the “ well being of the earth ” an ecologically literate society would be a sustainable society which did not destroy the natural environment on which they depend ecological literacy is a powerful concept as it creates a foundation for an integrated approach to environmental problems advocates champion eco literacy as a new educational paradigm emerging around the poles of holism systems thinking sustainability and complexity ecoliteracy concerns understanding the principles of organisation of ecosystems and their potential application to understanding how to build a sustainable human society it combines the sciences of systems and ecology in drawing together elements required to foster learning processes toward a deep appreciation of nature and our role in it systems thinking is the recognition of the world as an integrated whole rather than a collection of individual elements within systems thinking basic principles of organization become more important than the analysis of various components of the system in isolation ecological literacy and systems thinking implies a recognition of the manner in which all phenomenon are part of networks that define the way that element functions systems thinking is necessary to understand complex interdependence of ecological systems social systems and other systems on all levels according to fritjof capra “ in the coming decades the survival of humanity will depend on our ecological literacy – our ability to understand the basic principles of ecology and to live accordingly this means that ecoliteracy must become a critical skill for politicians business leaders and professionals in all spheres and should be the most important part of education at all levels – from primary and secondary schools to colleges universities and the continuing education and training of professionals ” david w orr has stated that the goal of ecological literacy is “ built on the recognition that the disorder of ecosystems reflects a prior disorder of mind making it a central concern to those institutions that purport to improve minds in other words the ecological crisis is in every way a crisis of education all education is environmental education … by what is included or excluded we teach the young that they are part of or apart from the natural world ” he also emphasizes that ecoliteracy does not only require mastery of subject matter but the creation of meaningful connections between head hands and heart as well others have reiterated the urgent importance of ecological literacy in today s world where young people are faced with escalating environmental challenges including climate change depletion of resources and environmentally linked illnesses this generation will require leaders and citizens who can think ecologically understand the interconnectedness of human and natural systems and have the will ability and courage to act — michael k stone with an understanding of ecological literacy perceptions naturally shift the need to protect the ecosystems is not simply a belief held by environmentalists it is a biological imperative for survival over the time this value will become a basic principle for prioritizing thought and action in a sustainable society in the face of the increasing capacity of industrial systems to destroy habitats and the climate system the explicit declaration of the principles of ecological literacy – and the resulting awareness of the importance of living within the ecological carrying capacity of the earth is increasingly necessary whether ecoliteracy can address the infamous value action gap is unclear
ecological yield is the harvestable population growth of an ecosystem it is most commonly measured in forestry sustainable forestry is defined as that which does not harvest more wood in a year than has grown in that year within a given patch of forest however the concept is also applicable to water soil and any other aspect of an ecosystem which can be both harvested and renewed — called renewable resources the carrying capacity of an ecosystem is reduced over time if more than the amount which is renewed refreshed or regrown or rebuilt is consumed ecosystem services analysis calculates the global yield of the earth s biosphere to humans as a whole this is said to be greater in size than the entire human economy however it is more than just yield but also the natural processes that increase biodiversity and conserve habitat which result in the total value of these services yield of ecological commodities like wood or water useful to humans is only a part of it very often an ecological yield in one place offsets an ecological load in another greenhouse gas released in one place for instance is fairly evenly distributed in the atmosphere and so greenhouse gas control can be achieved by creating a carbon sink literally anywhere else ecocide is thought by some green economists to be accelerated by debt instruments which demand a yield greater than the ecological capacity to renew this is a major question in monetary reform
in finance mainly for financial services firms economic capital is the amount of risk capital assessed on a realistic basis which a firm requires to cover the risks that it is running or collecting as a going concern such as market risk credit risk legal risk and operational risk it is the amount of money which is needed to secure survival in a worst case scenario firms and financial services regulators should then aim to hold risk capital of an amount equal at least to economic capital typically economic capital is calculated by determining the amount of capital that the firm needs to ensure that its realistic balance sheet stays solvent over a certain time period with a pre specified probability therefore economic capital is often calculated as value at risk the balance sheet in this case would be prepared showing market value rather than book value of assets and liabilities the first accounts of economic capital date back to the ancient phoenicians who took rudimentary tallies of frequency and severity of illnesses among rural farmers to gain an intuition of expected losses in productivity these calculations were advanced by correlations to climate change political outbreak and birth rate change the concept of economic capital differs from regulatory capital in the sense that regulatory capital is the mandatory capital the regulators require to be maintained while economic capital is the best estimate of required capital that financial institutions use internally to manage their own risk and to allocate the cost of maintaining regulatory capital among different units within the organization
an economic expansion is an increase in the level of economic activity and of the goods and services available it is a period of economic growth as measured by a rise in real gdp the explanation of fluctuations in aggregate economic activity between economic expansions and contractions is one of the primary concerns of macroeconomics typically an economic expansion is marked by an upturn in production and utilization of resources economic recovery and prosperity are two successive phases of expansion expansion may be caused by factors external to the economy such as weather conditions or technical change or by factors internal to the economy such as fiscal policies monetary policies the availability of credit interest rates regulatory policies or other impacts on producer incentives global conditions may influence the levels of economic activity in various countries economic contraction and expansion relate to the overall output of all goods and services while the terms inflation and deflation refer to increasing and decreasing prices of commodities goods and services in relation to the value of money expansion means enlarging the scale of a company the ways of expansion include internal expansion and integration internal expansion means a company enlarges its scale through opening branches inventing new products or developing new businesses integration means a company enlarges its scale through taking over or merging with other companies
economic freedom or economic liberty is the ability of members of a society to undertake economic actions this is a term used in economic and policy debates as well as in the philosophy of economics one approach to economic freedom comes from classical liberal and libertarian traditions emphasizing free markets free trade and private property under free enterprise another approach to economic freedom extends the welfare economics study of individual choice with greater economic freedom coming from a larger in some technical sense set of possible choices other conceptions of economic freedom include freedom from want and the freedom to engage in collective bargaining the free market viewpoint defines economic liberty as the freedom to produce trade and consume any goods and services acquired without the use of force fraud or theft this is embodied in the rule of law property rights and freedom of contract and characterized by external and internal openness of the markets the protection of property rights and freedom of economic initiative there are several indices of economic freedom that attempt to measure free market economic freedom empirical studies based on these rankings have found higher living standards economic growth income equality less corruption and less political violence to be correlated with higher scores on the country rankings it has been argued that the economic freedom indices conflate together unrelated policies and policy outcomes to conceal negative correlations between economic growth and economic freedom in some subcomponents
economic growth is the increase in the inflation adjusted market value of the goods and services produced by an economy over time it is conventionally measured as the percent rate of increase in real gross domestic product or real gdp usually in per capita terms growth is usually calculated in real terms – i e inflation adjusted terms – to eliminate the distorting effect of inflation on the price of goods produced measurement of economic growth uses national income accounting since economic growth is measured as the annual percent change of gross domestic product gdp it has all the advantages and drawbacks of that measure the rate of economic growth refers to the geometric annual rate of growth in gdp between the first and the last year over a period of time implicitly this growth rate is the trend in the average level of gdp over the period which implicitly ignores the fluctuations in the gdp around this trend an increase in economic growth caused by more efficient use of inputs such as labor productivity physical capital energy or materials is referred to as intensive growth gdp growth caused only by increases in the amount of inputs available for use increased population new territory is called extensive growth
economic inequality is the difference found in various measures of economic well being among individuals in a group among groups in a population or among countries economic inequality is sometimes called income inequality wealth inequality or the wealth gap economists generally focus on economic disparity in three metrics wealth income and consumption the issue of economic inequality is relevant to notions of equity equality of outcome and equality of opportunity economic inequality varies between societies historical periods economic structures and systems the term can refer to cross sectional distribution of income or wealth at any particular period or to changes of income and wealth over longer periods of time there are various numerical indices for measuring economic inequality a widely used index is the gini coefficient but there are also many other methods some studies say economic inequality is a social problem e g too much inequality can be destructive because it might hinder long term growth too much income equality is also destructive since it decreases the incentive for productivity and the desire to take on risks and create wealth
the economic lot scheduling problem elsp is a problem in operations management and inventory theory that has been studied by a large number of researchers for more than 50 years the term was first used in 1958 by professor jack d rogers of berkeley who extended the economic order quantity model to the case where there are several products to be produced on the same machine so that one must decide both the lot size for each product and when each lot should be produced the method illustrated by jack d rogers draws on a 1956 paper from welch w evert the elsp is a mathematical model of a common issue for almost any company or industry planning what to manufacture when to manufacture and how much to manufacture
materialism adj materialistic is the importance a consumer attaches to acquiring and consuming material goods also called acquisitiveness is often associated with a value system which regards social status as being determined by affluence see conspicuous consumption as well as the belief that possessions can provide happiness environmentalism can be considered a competing orientation to materialism materialism can be considered a pragmatic form of enlightened self interest based on a prudent understanding of the character of capitalist society however studies have found that it is also associated with self destructive behavior and depression
economic mobility is the ability of an individual family or some other group to improve or lower their economic status — usually measured in income economic mobility is often measured by movement between income quintiles economic mobility may be considered a type of social mobility which is often measured in change in income
the economic principle of satiation is the effect whereby the more of a good one possesses the less one is willing to give up in order to get more of it this effect is caused by diminishing marginal utility the effect whereby the consumer gains less utility per unit of a product the more units of a product he or she consumes for example if someone buys a can of cola they will enjoy it if they then buy a second one they will enjoy it less and so forth it can continue to the point where drinking a can of cola becomes a negative experience and beyond
economic security or financial security is the condition of having stable income or other resources to support a standard of living now and in the foreseeable future it includes probable continued solvency predictability of the future cash flow of a person or other economic entity such as a country employment security or job security financial security more often refers to individual and family money management and savings economic security tends to include the broader effect of a society s production levels and monetary support for non working citizens
ecthyma is a variation of impetigo presenting at a deeper level of tissue it is usually associated with group a beta hemolytic streptococcus abbreviated gas
ecthyma gangrenosum is an infection of the skin typically caused by pseudomonas aeruginosa it is often seen in immunocompromised patients such as those with neutropenia ecthyma gangrenosum presents as a round or oval lesion 1 0 to 15 cm in diameter with a halo of erythema a necrotic center is usually present with a surrounding erythematous edge representing where the organism invaded blood vessels and caused infarctions these ulcerative lesions are single or multiple and heal with scar formation although sepsis resulting from other gram negative bacteria can also cause this condition
ectodermal dysplasia is not a single disorder but a group of syndromes all deriving from abnormalities of the ectodermal structures more than 150 different syndromes have been identified despite some of the syndromes having different genetic causes the symptoms are sometimes very similar diagnosis is usually by clinical observation often with the assistance of family medical histories so that it can be determined whether transmission is autosomal dominant or recessive worldwide around 7 000 people have been diagnosed with an ectodermal dysplasia condition some ed conditions are only present in single family units and derive from very recent mutations ectodermal dysplasias can occur in any race but are much more prevalent in caucasians than any other group and especially in fair caucasians ectodermal dysplasias are described as heritable conditions in which there are abnormalities of two or more ectodermal structures such as the hair teeth nails sweat glands salivary glands cranial facial structure digits and other parts of the body
ectodermal dysplasia with corkscrew hairs is a skin condition with salient features including exaggerated pili torti scalp keloids follicular plugging keratosis pilaris xerosis eczema palmoplantar keratoderma syndactyly onchodysplasia and conjunctival neovascularization
ectogenesis from the greek ecto outer and genesis is the growth of an organism in an artificial environment outside the body in which it would normally be found such as the growth of an embryo or fetus outside the mother s body or the growth of bacteria outside the body of a host the term was coined by british scientist j b s haldane in 1924
ectomesenchymoma is a rare fast growing tumor of the nervous system or soft tissue that occurs mainly in children although cases have been reported in patients up to age 60 ectomesenchymomas may form in the head and neck abdomen perineum scrotum or limbs also called malignant ectomesenchymoma malignant ectomesenchymoma mem is a rare tumor of soft tissues or the cns which is composed of both neuroectodermal elements represented by ganglion cells and or well differentiated or poorly differentiated neuroblastic cells such as ganglioneuroma ganglioneuroblastoma neuroblastoma peripheral primitive neuroectodermal tumors – pnet and one or more mesenchymal neoplastic elements usually rhabdomyosarcoma the most accepted theory suggests that this tumor arises from remnants of migratory neural crest cells and thus from the ectomesenchyme
an ectoparasitic infestation is a parasitic disease caused by organisms that live primarily on the surface of the host examples scabies crab louse pubic lice pediculosis head lice lernaeocera branchialis cod worm
in medicine an ectopia ɛkˈtoʊpiə is a displacement or malposition of an organ or other body part which is then referred to as ectopic ɛkˈtɒpɪk most ectopias are congenital but some may happen later in life
ectopia cordis greek away out of place latin heart is a congenital malformation in which the heart is abnormally located either partially or totally outside of the thorax the ectopic heart can be found along a spectrum of anatomical locations including the neck chest or abdomen in most cases the heart protrudes outside the chest through a split sternum
ectopia lentis is a displacement or malposition of the eye s crystalline lens from its normal location a partial dislocation of a lens is termed lens subluxation or subluxated lens a complete dislocation of a lens is termed lens luxation or luxated lens
ectopic beat or cardiac ectopy is a disturbance of the cardiac rhythm frequently related to the electrical conduction system of the heart in which beats arise from fibers or group of fibers outside the region in the heart muscle ordinarily responsible for impulse formation i e the sinoatrial node an ectopic beat can be further classified as either a premature ventricular contraction or a premature atrial contraction some patients describe this experience as a flip or a jolt in the chest or a heart hiccups while others report dropped or missed beats ectopic beats are more common during periods of stress or debility they may also be triggered by consumption of some food like alcohol strong cheese or chocolate it is a form of cardiac arrhythmia in which ectopic foci within either ventricular or atrial myocardium or from finer branches of the electric transduction system cause additional beats of the heart some medications may worsen the phenomenon
ectopic calcification is a pathologic deposition of calcium salts in tissues or bone growth in soft tissues this can be a symptom of hyperphosphatemia formation of osseous tissue in soft tissues such as the lungs eyes arteries or other organs is known as ectopic calcification dystrophic calcification or ectopic ossification
ectopic enamel is an abnormality in the shape of teeth it is tooth enamel that is found in an unusual location such as at the root of a tooth
ectopic pregnancy also known as eccyesis or tubal pregnancy is a complication of pregnancy in which the embryo attaches outside the uterus signs and symptoms classically include abdominal pain and vaginal bleeding less than 50 percent of women have both of these symptoms the pain may be described as sharp dull or crampy pain may also spread to the shoulder if bleeding into the abdomen has occurred severe bleeding may result in a fast heart rate fainting or shock with very rare exceptions the fetus is unable to survive risk factors for ectopic pregnancy include pelvic inflammatory disease often due to chlamydia infection tobacco smoking prior tubal surgery a history of infertility and the use of assisted reproductive technology those who have previously had an ectopic pregnancy are at much higher risk of having another one most ectopic pregnancies 90 occur in the fallopian tube which are known as tubal pregnancies implantation can also occur on the cervix ovaries or within the abdomen detection of ectopic pregnancy is typically by blood tests for human chorionic gonadotropin hcg and ultrasound this may require testing on more than one occasion ultrasound works best when performed from within the vagina other causes of similar symptoms include miscarriage ovarian torsion and acute appendicitis prevention is by decreasing risk factors such as chlamydia infections through screening and treatment while some ectopic pregnancies will resolve without treatment this approach has not been well studied as of 2014 the use of the medication methotrexate works as well as surgery in some cases specifically it works well when the beta hcg is low and the size of the ectopic is small surgery is still typically recommended if the tube has ruptured there is a fetal heartbeat or the person s vital signs are unstable the surgery may be laparoscopic or through a larger incision known as a laparotomy outcomes are generally good with treatment the rate of ectopic pregnancy is about 1 and 2 that of live births in developed countries though it may be as high as 4 among those using assisted reproductive technology it is the most common cause of death during the first trimester at approximately 10 of the total in the developed world outcomes have improved while in the developing world they often remain poor the risk of death among those in the developed world is between 0 1 and 0 3 percent while in the developing world it is between one and three percent the first known description of an ectopic pregnancy is by albucasis in the 11 th century the word ectopic means out of place
salivary gland tissue which is located in sites other than the normal location is variously described as aberrant accessory ectopic heterotopic or salivary gland choristoma
a ectopic testis is a testicle that although not an undescended testicle has taken a non standard path through the body and ended up in an unusual location the positions of the ectopic testis may be in the lower part of the abdomen front of thigh femoral canal skin of penis or behind the scrotum the testis is usually developed and accompanied by an indirect inguinal hernia it may be divorced from the epididymis which may lie in the scrotum
ectopic thymus is a condition where thymus tissue is found in an abnormal location it can be associated with failure of descent it can also be associated with failure of involution
ectopic ureter or ureteral ectopia is a medical condition where the ureter rather than terminating at the urinary bladder terminates at a different site in males this site is usually the urethra in females this is usually the urethra or vagina it can be associated with renal dysplasia frequent urinary tract infections and urinary incontinence usually continuous drip incontinence ectopic ureters are found in 1 of every 2000 – 4000 patients and can be difficult to diagnose but are most often seen on ct scans ectopic ureter is commonly a result of a duplicated renal collecting system a duplex kidney with 2 ureters in this case usually one ureter drains correctly to the bladder with the duplicated ureter presenting as ectopic
ectrodactyly split hand cleft hand derived from the greek ektroma abortion and daktylos finger involves the deficiency or absence of one or more central digits of the hand or foot and is also known as split hand split foot malformation shfm the hands and feet of people with ectrodactyly are often described as claw like and may include only the thumb and one finger usually either the little finger ring finger or a syndactyly of the two with similar abnormalities of the feet it is a rare form of a congenital disorder in which the development of the hand is disturbed it is a type i failure of formation – longitudinal arrest the central ray of the hand is affected and usually appears without proximal deficiencies of nerves vessels tendons muscles and bones in contrast to the radial and ulnar deficiencies the cleft hand appears as a v shaped cleft situated in the centre of the hand the digits at the borders of the cleft might be syndactilyzed and one or more digits can be absent in most types the thumb ring finger and little finger are the less affected parts of the hand the incidence of cleft hand varies from 1 in 90 000 to 1 in 10 000 births depending on the used classification cleft hand can appear unilateral or bilateral and can appear isolated or associated with a syndrome split hand foot malformation shfm is characterized by underdeveloped or absent central digital rays clefts of hands and feet and variable syndactyly of the remaining digits shfm is a heterogeneous condition caused by abnormalities at one of multiple loci including shfm 1 shfm 1 at 7 q 21 q 22 shfm 2 xq 26 shfm 3 fbxw 4 dactylin at 10 q 24 shfm 4 tp 63 at 3 q 27 and shfm 5 dlx 1 and dlx 2 at 2 q 31 shfm 3 is unique in that it is caused by submicroscopic tandem chromosome duplications of fbxw 4 dactylin shfm 3 is considered isolated ectrodactyly and does not show a mutation of the tp 63 gene
ectrodactyly – ectodermal dysplasia – cleft syndrome or eec and also referred to as eec syndrome also known as split hand – split foot – ectodermal dysplasia – cleft syndrome is a rare form of ectodermal dysplasia an autosomal dominant disorder inherited as an genetic trait eec is characterized by the triad of ectrodactyly ectodermal dysplasia and facial clefts other features noted in association with eec include vesicoureteral reflux recurrent urinary tract infections obstruction of the nasolacrimal duct decreased pigmentation of the hair and skin missing or abnormal teeth enamel hypoplasia absent punctae in the lower eyelids photophobia occasional cognitive impairment and kidney anomalies and conductive hearing loss
ectromelia is a congenital condition where long bones are missing or underdeveloped examples include amelia hemimelia phocomelia sirenomelia
ectropion is a medical condition in which the lower eyelid turns outwards it is one of the notable aspects of newborns exhibiting congenital harlequin type ichthyosis but ectropion can occur due to any weakening of tissue of the lower eyelid the condition can be repaired surgically ectropion is also found in dogs as a genetic disorder in certain breeds
eczema herpeticum is a rare but severe disseminated infection that generally occurs at sites of skin damage produced by for example atopic dermatitis burns long term usage of topical steroids or eczema it is also known as kaposi varicelliform eruption pustulosis varioliformis acute and kaposi juliusberg dermatitis some sources reserve the term eczema herpeticum when the cause is due to human herpes simplex virus and the term kaposi varicelliform eruption to describe the general presentation without specifying the virus this condition is most commonly caused by herpes simplex virus type 1 or 2 but may also be caused by coxsackievirus a 16 or vaccinia virus it appears as numerous umbilicated vesicles superimposed on healing atopic dermatitis it is often accompanied by fever and lymphadenopathy eczema herpeticum can be life threatening in babies
eczema vaccinatum is a rare severe adverse reaction to smallpox vaccination it is characterized by serious local or disseminated umbilicated vesicular crusting skin rashes in the face neck chest abdomen upper limbs and hands caused by widespread infection of the skin in people with previous diagnosed skin conditions such as eczema or atopic dermatitis even if the conditions are not active at the time other signs and symptoms include fever and facial and supraglottic edema the condition may be fatal if severe and left untreated survivors are likely to have some scarring pockmarks smallpox vaccine should not be given to patients with a history of eczema because of the danger of transmission of vaccinia it also should not be given to people in close contact with anyone who has active eczema and who has not been vaccinated people with other skin diseases such as atopic dermatitis burns impetigo or herpes zoster also have an increased risk of contracting eczema vaccinatum and should not be vaccinated against smallpox eczema is also associated with increased complications related to other vesiculating viruses such as chickenpox this is called eczema herpeticum
eczematid like purpura of doucas and kapetanakis is a medical term for a lymphocytic capillaritis of unknown cause lesions consist of erythematous and purpuric macules which usually begin around the ankles coalesce and spread to involve the whole legs and sometimes the trunk and upper extremities the lesions are extremely pruritic and occasionally lichenified after prolonged scratching
edema or oedema is an abnormal accumulation of fluid in the interstitium located beneath the skin and in the cavities of the body which can cause severe pain clinically edema manifests as swelling the amount of interstitial fluid is determined by the balance of fluid homeostasis and the increased secretion of fluid into the interstitium or the impaired removal of the fluid can cause the condition the word is from greek οἴδημα oídēma meaning swelling
edema blisters also known as edema bulla hydrostatic bulla and stasis blister are a cutaneous condition that develop in patients with an acute exacerbation of chronic edema particularly of the lower extremities and in the setting of anasarca
edentulism is the condition of being toothless to at least some degree in organisms such as humans that naturally have dentition it is the result of tooth loss loss of some teeth results in partial edentulism whereas loss of all teeth results in complete edentulism persons who have lost teeth are either partially or completely edentulous edentate whereas those who have not lost teeth can be called dentate by comparison for example a scientific study may include a partially edentulous group and a healthy dentate control group organisms that never possessed teeth can also be described as edentulous such as members of the former zoological classification order of edentata which included anteaters and sloths all of which possess no anterior teeth and either no or poorly developed posterior teeth in naturally dentate species edentulism is more than just the simple presence or absence of teeth it is biochemically complex because the teeth jaws and oral mucosa are not static objects they are dynamic changing over time processes such as bone remodeling loss and gain of bone tissue in the jaws and inflammation of soft tissue in response to the oral microbiota are clinically important for edentulous people for example bone resorption in the jaw is frequently how the teeth were able to detach in the first place the jaw in an edentulous area undergoes further resorption even after the teeth are gone and insertion of dental implants can elicit new bone formation leading to osseointegration meanwhile bacteria and yeasts of the oral cavity and the immune system of their host create an immensely complicated and constantly changing interplay that presents clinically as gingivitis caries stomatitis and other periodontal pathology
an edge case is a problem or situation that occurs only at an extreme maximum or minimum operating parameter for example a stereo speaker might noticeably distort audio when played at its maximum rated volume even in the absence of other extreme settings or conditions an edge case can be expected or unexpected in engineering the process of planning for and gracefully addressing edge cases can be a significant task and one that may be overlooked or underestimated non trivial edge cases can result in a failure of the object being engineered that may not have been imagined during the design phase or anticipated as possible during normal use for this reason attempts to formalize good engineering practices often incorporate information about dealing with edge cases
an edit conflict is a computer problem where multiple editors cannot all edit the same item during a short time period the problem is encountered on wikis or distributed data systems an edit conflict occurs when a shared document is being edited by more than one person at the same time and the attempted changes are treated as incompatible with each other one person attempts to edit the document but upon trying to save the new version another person has already modified the document in the intervening time period thus causing a difference between the attempted edit and the already made edit that must be resolved manually and causing an edit conflict error message computer writer gary b shelly notes that many wiki systems will block the contributor who is attempting to edit the page from being able to do so until the contributor currently editing the page saves changes or remains idle on the page for an extended period of time the problem can occur when working on heavily edited articles on wikipedia such as those about a current event or a person suddenly in the news as well as other high traffic pages if a significant amount of new text is involved the editor who receives an edit conflict error message can cut and paste the new text into a word processor or similar program for further editing or can paste that text directly into a newer version of the target document simple copyediting can be done directly on the newer version and then saved edit conflicts can also arise when two or more editors are working on google sites or when two or more users simultaneously edit the same file in a revision control system which does not have file locking
educational inequality is the difference in the learning results or efficacy experienced by students coming from different groups educational efficacy is most often measured by grades gpa scores test scores drop out rates college entrance statistics and college completion rates much of educational inequality is attributed to economic disparities that often falls along racial lines and much modern conversation about educational equity conflates the two showing how they are inseparable from residential location and more recently language educational inequality between white students and minority students continues to perpetuate social and economic inequality throughout the world there have been continuous attempts to reform education at all levels with different causes that are deeply rooted in history society and culture this inequality is difficult to eradicate although difficult education is vital to society ’ s movement forward it promotes “ citizenship identity equality of opportunity and social inclusion social cohesion as well as economic growth and employment ” and for these reasons equality is widely promoted unequal educational outcomes are attributed to several variables including family of origin gender and social class achievement earnings health status and political participation also contribute to educational inequality within the united states and other countries family background in harvard s civil rights project lee and orfield identify family background as the most influential factor in student achievement a correlation exists between the academic success of parents with the academic success of their children only 11 of children from the bottom fifth earn a college degree while 80 of the top fifth earn one linked with resources white students tend to have more educated parents than students from minority families this translates to a home life that is more supportive of educational success this often leads to them receiving more at home help have more books in their home attend more libraries and engage in more intellectually intensive conversations children then enter school at different levels poor students are behind in verbal memory vocabulary math and reading achievement and have more behavior problems this leads to their placement in different level classes that tracks them these courses almost always demand less from their students creating a group that is conditioned to lack educational drive these courses are generally non college bound and are taught by less qualified teachers also family background influences cultural knowledge and perceptions middle class knowledge of norms and customs allows students with this background to better navigate the school system parents from this class and above also have social networks that prove to be more beneficial than networks based in lower classes these connections may help students gain access to the right schools activities etc additionally children from poorer families who are often minorities come from families that distrust institutions america s history of racism and discrimination has created a perceived and or existent ceiling on opportunities for many poor and minority citizens this ceiling muffles academic inspirations and muffles growth the recent and drastic increase of latino immigrants has created another major factor in educational inequality as more and more students come from families where english is not spoken at home they often struggle with overcoming a language barrier in addition to simply learning subjects they more frequently lack assistance at home because it is common for the parents to not understand the work that is in english furthermore research reveals summer months as crucial time for the educational development of children students from disadvantaged families experience greater losses in skills during summer vacation students from lower socioeconomic classes come disproportionately from single parent homes and dangerous neighborhoods 15 of white children are raised in single parent homes and 10 of asian children are 27 of latinos are raised in single parent homes and 54 of african american children are less resources less parental attention and more stress all influence the performance of children in school gender throughout the world educational achievement varies by gender the exact relationship differs across cultural and national contexts female disadvantage obstacles preventing females ability to receive a quality education include traditional attitudes towards gender roles poverty geographical isolation gender based violence and early marriage and pregnancy throughout the world there is an estimated 7 million more girls than boys out of school this girls gap is concentrated in several countries including somalia afghanistan togo the central african republic and democratic republic of the congo in the democratic republic of the congo girls are outnumbered two to one socialized gender roles affect females access to education for example in nigeria children are socialized into their specific gender role as soon as their parents know their gender men are the preferred gender and are encouraged to engage in computer and scientific learning while the women learn domestic skills these gender roles are deep rooted within the state however with the increase of westernized education within nigeria there has been a recent increase in women having the ability to receive an equal education there is still much to be changed though nigeria still needs policies that encourage educational attainment for men and women based on merit rather than gender females are shown to be at risk of being attacked in at least 15 countries attacks can occur because individuals within those countries do not believe women should receive an education attacks include kidnappings bombings torture rape and murder in somalia girls have been abducted in colombia the democratic republic of the congo and libya students were reported to have been raped and harassed in pakistan and afghanistan schools and busses have been bombed and gassed early marriage effects females ability to receive an education the gap separating men and women in the job market remains wide in many countries whether in the north or the south with marginal variables between most countries women have a lower employment rate are unemployed longer are paid less and have less secure jobs young women particularly suffer double discrimination first for being young in the difficult phase of transition between training and working life in an age group that has on an average twice the jobless rate or older workers and are at the mercy of employers who exploit them under the pretext of enabling them to acquire professional experience secondly they are discriminated against for being women and are more likely to be offered low paying or low status jobs discrimination is still very much in evidence and education and training policies specially targeting young women are needed to restore a balance although young women are increasingly choosing typically male ’ professions they remain over represented in traditionally female jobs such as secretaries nurses and under represented in jobs with responsibility and the professions in early grades boys and girls perform equally in mathematics and science but boys score higher on advanced mathematics assessments such as the sat college entrance examination girls are also less likely to participate in class discussions and more likely to be silent in the classroom some believe that females have a way of thinking and learning that is different than males belenky and colleagues 1986 conducted research which found that there was an inconsistency between the kind of knowledge appealing to women and the kind of knowledge being taught in most educational institutions another researcher gilligan 1982 found that the knowledge appealing to females was caring interconnection and sensitivity to the needs of others while males found separation and individualism appealing females are more field dependent or group oriented than males which could explain why they may experience problems in schools that primarily teach using an individualistic learning environment males also earn more than women at every educational level in part because of their occupations if both a male and female possess the same professional degree the male will more than likely receive a larger salary than a female this pattern progresses and widens from a person with a high school diploma to a person possessing a doctoral degree
edwards syndrome also known as trisomy 18 is a genetic disorder caused by the presence of all or part of a third copy of chromosome 18 many parts of the body are affected babies are often born small and have heart defects other features include a small head small jaw clenched fists with overlapping fingers and severe intellectual disability most cases of edwards syndrome occur due to problems during the formation of the reproductive cells or during early development the rate of disease increases with the mother s age rarely cases may be inherited from a person s parents occasionally not all cells have the extra chromosome known as mosaic trisomy and symptoms in these cases may be less severe ultrasound can increase suspicion for the condition which can be confirmed by amniocentesis treatment is supportive after having one child with the condition the risk of having a second is typically around one percent it is the second most frequent condition due to a third chromosome at birth after down syndrome edwards syndrome occurs in around one in 5 000 live births most babies born with the condition are female many of those affected die before birth survival beyond a year of life is around 7 5 it is named after john hilton edwards who first described the syndrome in 1960
effacement is the shortening or thinning of a tissue it can refer to cervical effacement it can also refer to a process occurring in podocytes in nephrotic syndrome in histopathology it refers to the near obliteration of a tissue as in the normal parenchyma of tissues in the case of some cancers
the amount of heat energy received at any location on the globe is a direct effect of sun angle on climate as the angle at which sunlight strikes the earth varies by location time of day and season due to the earth s orbit around the sun and the earth s rotation around its tilted axis seasonal change in the angle of sunlight caused by the tilt of the earth s axis is the basic mechanism that results in warmer weather in summer than in winter change in day length is another factor see also season
the effective marginal tax rate emtr is the combined effect on a person s earnings of income tax and the withdrawal of means testing of state welfare benefits the emtr is the percentage of an extra unit of income extra dollar euro yen etc that the recipient loses due to income taxes payroll taxes and any decline in tax credits and welfare entitlements calculating the emtr is typically very dependent on individual circumstances and involves a consideration of welfare withdrawal rules income tax laws low income tax offsets tax rebates and the individuals tax and welfare status as such tables showing emtrs are rarely published the net effect however is generally a higher effective marginal rate of tax than that suggested by income tax tables
the effects of long term benzodiazepine use include drug dependence as well as the possibility of adverse effects on cognitive function physical health and mental health benzodiazepines are generally effective when used therapeutically in the short term most of the problems associated with benzodiazepines result from their long term use there are significant physical mental and social risks associated with the long term use of benzodiazepines although anxiety can temporarily increase as a withdrawal symptom there is evidence that a reduction or withdrawal from benzodiazepines can lead in the long run to a reduction in anxiety symptoms due to these increasing physical and mental symptoms from long term use of benzodiazepines slowly withdrawing from benzodiazepines is recommended for many long term users not everyone however experiences problems with long term use some of the symptoms that could possibly occur as a result of a withdrawal from benzodiazepines after long term use include emotional clouding flu like symptoms nausea headaches dizziness irritability lethargy sleep problems memory impairment personality changes aggression depression social deterioration as well as employment difficulties while others never have any side effects from long term benzodiazepine use one should never abruptly stop using this medicine and should wean themself down to a lower dose under doctor supervision while benzodiazepines are highly effective in the short term adverse effects in some people associated with long term use including impaired cognitive abilities memory problems mood swings and overdoses when combined with other drugs may make the risk benefit ratio unfavourable while others experience no ill effects in addition benzodiazepines have reinforcing properties in some individuals and thus are considered to be addictive drugs especially in individuals that have a drug seeking behavior in addition a physical dependence can develop after a few weeks or months of use many of these adverse effects of long term use of benzodiazepines begin to show improvements three to six months after withdrawal other concerns about the effects of long term benzodiazepine use in some include dose escalation benzodiazepine abuse tolerance and benzodiazepine dependence and benzodiazepine withdrawal problems both physiological tolerance and dependence can lead to a worsening of the adverse effects of benzodiazepines increased risk of death has been associated with long term use of benzodiazepines in several studies however other studies have not found increased mortality due to conflicting findings in studies regarding benzodiazepines and increased risks of death including from cancer further research in long term use of benzodiazepines and mortality risk has been recommended most of the research has been conducted in prescribed users of benzodiazepines even less is known about the mortality risk of illicit benzodiazepine users the long term use of benzodiazepines is controversial and has generated significant controversy within the medical profession views on the nature and severity of problems with long term use of benzodiazepines differ from expert to expert and even from country to country some experts even question whether there is any problem with the long term use of benzodiazepines
the eruption of the eyjafjallajökull volcano in iceland on 19 april 2010 affected the economic political and cultural activities in europe and across the world there is a extensive air travel disruption caused by the closure of airspace over many countries affecting the travel arrangements of hundreds of thousands of people in europe and elsewhere sporting entertainment and many other events were cancelled delayed or disrupted when individuals or teams were unable to travel to their destination the state funeral of minute proportions on 18 april 2010 was affected as some national leaders were unable to attend including barack obama stephen harper angela merkel and nicolas sarkozy
effeminacy is the manifestation of traits in a boy or man that are more often associated with feminine nature behavior mannerism style or gender roles rather than with masculine nature behavior mannerisms style or roles it is a term frequently applied to womanly behavior demeanor style clothing and appearance displayed by a boy or man typically used implying criticism or ridicule of this behavior as opposed to for example merely describing a man as feminine which can be non judgmental the term effeminate is most often used by people who subscribe to the widespread view that males should display masculine traits and behaviors generally the description is applied to individuals but may be used to describe entire societies as an inflammatory allegation until the modern period effeminacy in the western tradition referred to a complicated intersection of both social or civic and sexual identities typically associated with women the ancient greeks for example described whole societies as effeminate malakia if they were characterized by a slavish deferential or autocratic political culture here it was the form of sexual relationships but not the fact of homosexual relations which were not uncommon among greek citizens who were men that was critical to the sexual dimension of the term and among early modern partisans of the republican tradition the term might be applied to those who were preoccupied with womanly concerns such as the accouterments of appearance which were often associated with trappings of nobility or aristocratic aspirations such as ostentatious dress decadence in consumption habits and rigid adherence to the proprieties or manners of social hierarchy the reach of this civic understanding may be best illustrated in the work of early feminist and republican thinkers such as mary wollstonecraft who described as effeminate the behavior of women who refused to embrace a more active presence in public life since the 18 th century the civic dimension of gender identity has been eclipsed by the sexual dimension of gender identity and today effeminacy has often been considered a vice indicative of other negative character traits and often involving a pejorative insinuation of homosexual tendencies in boys or men in other societies by contrast effeminate boys or men may be considered a distinct human gender third gender and may have a special social function as is the case of two spirits in some native american groups furthermore some see effeminacy to be a characteristic or trait part of a particular person s gender role and in this sense would not be considered a vice or indicative of any other characteristics an effeminate boy or man is similar to a fop or a dandy though these tend to be archaic identities that are taken on by the individual rather than insulting labels
efficiency is the often measurable ability to avoid wasting materials energy efforts money and time in doing something or in producing a desired result in a more general sense it is the ability to do things well successfully and without waste in more mathematical or scientific terms it is a measure of the extent to which input is well used for an intended task or function output it often specifically comprises the capability of a specific application of effort to produce a specific outcome with a minimum amount or quantity of waste expense or unnecessary effort efficiency of course refers to very different inputs and outputs in different fields and industries efficiency is very often confused with effectiveness in general efficiency is a measurable concept quantitatively determined by the ratio of useful output to total input effectiveness is the simpler concept of being able to achieve a desired result which can be expressed quantitatively but doesn t usually require more complicated mathematics than addition efficiency can often be expressed as a percentage of the result that could ideally be expected for example if no energy were lost due to friction or other causes in which case 100 of fuel or other input would be used to produce the desired result this does not always apply not even in all cases in which efficiency can be assigned a numerical value e g not for specific impulse a common but confusing way of distinguishing between efficiency and effectiveness is the saying efficiency is doing things right while effectiveness is doing the right things this saying indirectly emphasizes that the selection of objectives of a production process is just as important as the quality of that process this saying popular in business however obscures the more common sense of effectiveness which would should produce the following mnemonic efficiency is doing things right effectiveness is getting things done this makes it clear that effectiveness for example large production numbers can also be achieved through inefficient processes if for example workers are willing or used to working longer hours or with greater physical effort than in other companies or countries or if they can be forced to do so similarly a company can achieve effectiveness for example large production numbers through inefficient processes if it can afford to use more energy per product for example if energy prices or labor costs or both are lower than for its competitors for example one may measure how directly two objects are communicating downloading music directly from a computer to a mobile device is more efficient than using a mobile device s microphone to record music sounds that come from a computer s speakers efficiency is often measured as the ratio of useful output to total input which can be expressed with the mathematical formula r p c where p is the amount of useful output product produced per the amount c cost of resources consumed this may correspond to a percentage if products and consumables are quantified in compatible units and if consumables are transformed into products via a conservative process for example in the analysis of the energy conversion efficiency of heat engines in thermodynamics the product p may be the amount of useful work output while the consumable c is the amount of high temperature heat input due to the conservation of energy p can never be greater than c and so the efficiency r is never greater than 100 and in fact must be even less at finite temperatures
efficient cake cutting is a problem in economics and computer science it involves a heterogenous resource such as a cake with different toppings or a land with different coverings that is assumed to be divisible it is possible to cut arbitrarily small pieces of it without destroying their value the resource has to be divided among several partners who have different preferences over different parts of the cake i e some people prefer the chocolate toppings some prefer the cherries some just want as large a piece as possible etc the division should be pareto efficient most often efficiency is studied in connection with fairness and the goal is to find a division which satisfies both efficiency and fairness criteria
a volcanic eruption is effusive when low viscosity magma usually basaltic in composition is released from the earth s crust in an effusive eruption gas escaped the magma as it erupts and forms lava that flows downhill continuously this type of lava flow can build shield volcanoes which are numerous in hawaii eruptions of basaltic magma often transition between effusive and explosive eruption patterns the behavior of these eruptions is largely dependent on the permeability of the magma and the magma ascent rate for an effusive eruption to occur magma must be permeable enough to allow the expulsion of gas bubbles contained within it if the magma is not above a certain permeability threshold it cannot degas and will erupt explosively additionally at a certain threshold fragmentation within the magma can cause an explosive eruption this threshold is governed by the reynolds number a dimensionless number in fluid dynamics that is directly proportional to fluid velocity eruptions will be effusive if the magma has a low ascent velocity at higher magma ascent rates the fragmentation within the magma passes a threshold and results in explosive eruptions silicic magma also exhibits this transition between effusive and explosive eruptions but the fragmentation mechanism differs the 1912 novarupta eruption and the 2003 stromboli eruption both exhibited a transition between explosive and effusive eruption patterns effusive basalt lava flows cool to either of two forms ʻaʻā or pāhoehoe andesite lava typically forms blocky lava flows dacite lava flows often form steep sided mounds called lava domes due to their greater viscosity
the efimov effect is an effect in the quantum mechanics of few body systems predicted by the russian theoretical physicist v n efimov in 1970 efimov ’ s effect is where three identical bosons interact with the prediction of an infinite series of excited three body energy levels when a two body state is exactly at the dissociation threshold one corollary is that there exist bound states called efimov states of three bosons even if the two particle attraction is too weak to allow two bosons to form a pair a three particle efimov state where the two body sub systems are unbound are often depicted symbolically by the borromean rings this means that if one of the particles is removed the remaining two fall apart in this case the efimov state is also called a borromean state
egg allergy is a type of food allergy it is a hypersensitivity to dietary substances from the yolk or whites of eggs causing an overreaction of the immune system which may lead to severe physical symptoms for millions of people around the world egg allergy appears mainly but not exclusively in children in fact it is the second most common food allergy in children it is usually treated with an exclusion diet and vigilant avoidance of foods that may be contaminated with egg the most severe allergy reaction is called anaphylaxis and is an emergency requiring immediate attention and treatment with epinephrine the asthma and allergy foundation of america estimates that most children outgrow egg allergy by the age of five but some people remain allergic for a lifetime
egg drop syndrome is a viral disease of birds notably chickens ducks geese and swans the phrase egg drop refers to the drop in egg production which is how the disease is usually detected clinical signs being unreliable the disease results in thin shelled or shell less eggs being laid
ego dystonic sexual orientation is an ego dystonic mental disorder characterized by having a sexual orientation or an attraction that is at odds with one s idealized self image causing anxiety and a desire to change one s orientation or become more comfortable with one s sexual orientation it describes not innate sexual orientation itself but a conflict between the sexual orientation one wishes to have and the sexual orientation one actually possesses
egocentric predicament a term coined by ralph barton perry in an article journal of philosophy 1910 is the problem of not being able to view reality outside of our own perceptions all worldly knowledge takes the form of mental representations that our mind examines in different ways direct contact with reality cannot be made outside of our own minds therefore we cannot be sure reality even exists this means that we are each limited to our own perceptual world and views solipsism is an extension of this which assumes that only one s own mind is sure to exist since 1710 when george berkeley broached in his fashion the problem of the egocentric predicament denying the existence of material substance except as ideas in the minds of perceivers and thus asserting a problematical relation with reality hence has this thesis proved a stumbling block samuel johnson is well known for his refutation of bishop berkeley s immaterialism his claim that matter did not actually exist but only seemed to exist during a conversation with boswell johnson powerfully stomped a nearby stone and proclaimed of berkeley s theory i refute it thus both perry s concept and the term he used influenced american philosopher everett w hall to create the solecism the categorio centric predicament to express the impossibility of seeing the world outside the categories imposed by one s native language and conceptual scheme after we came out of the church we stood talking for some time together of bishop berkeley s ingenious sophistry to prove the non existence of matter and that every thing in the universe is merely ideal i observed that though we are satisfied his doctrine is not true it is impossible to refute it i never shall forget the alacrity with which johnson answered striking his foot with mighty force against a large stone till he rebounded from it i refute it thus “ ” boswell s life of samuel johnson there ought to be something wrong with it but it appears invulnerable even as it is absurd what is really wrong with it although it is not at all easy to reconcile egocentric predicament with our role in this figmental universe when those experiences include pain or pleasure this may or may not a common question that may arise what is the nature of the universe questioning whether or not one s observations are real may pose a serious obstacle in life which may prove impossible to overcome for some observation in itself is a complex riddle unsolved by our own kind being the reason behind this supposed diseased state of mind
ehlers – danlos syndrome eds is a group of genetic connective tissue disorders symptoms can vary from mildly loose joints to life threatening complications such as aortic dissection chronic pain or early osteoarthritis may also occur eds is caused by a defect in the structure production or processing of collagen or proteins that interact with collagen the collagen in connective tissue helps tissues resist deformation collagen is an important contributor to the physical strength of tissue abnormal collagen renders these structures more elastic in some cases it can be life threatening people with joint pain may be misdiagnosed with hypochondriasis depression chronic fatigue syndrome or other conditions there may be poor knowledge about eds among practitioners there is no cure for eds treatment is supportive including close monitoring of the digestive excretory and particularly the cardiovascular systems physical therapy bracing and corrective surgery may help with injuries and pain that tend to develop in certain types of eds although extra caution and special practices are advised to prevent permanent damage eds is a long term disease eds affects about 1 in 5 000 people globally excess mobility was first described by hippocrates in 400 bc the syndrome is named after two physicians edvard ehlers from denmark and henri alexandre danlos from france who described it at the turn of the 20 th century
heartwater also known as cowdriosis nintas and ehrlichiosis is a tick borne rickettsial disease of domestic and wild ruminants it is caused by ehrlichia ruminantium formerly cowdria ruminantium an intracellular gram negative coccal bacterium also referred to as rickettsia ruminantium the disease is spread by bont ticks which are members of the genus amblyomma affected mammals include cattle sheep goats antelope and buffalo but the disease has the biggest economic impact on cattle production in affected areas the disease ’ s name is derived from the fact that fluid can collect around the heart or in the lungs of infected animals the disease is common in sub saharan africa and some of the west indian islands it was first identified in sheep in south africa in the 1830 s and had reached the caribbean by 1980 the ticks which carry the disease occur in africa and the caribbean and feed on a wide variety of vertebrate hosts in the caribbean at least the cattle egret has been implicated in the spread of heartwater since it colonized the islands in the 1950 s animals often acquire the disease when moved on to heartwater infected grazing cowdriosis is notifiable to the world organisation for animal health
ehrlichiosis is a tickbornebacterial infection caused by bacteria of the family anaplasmataceae genera ehrlichia and anaplasma these obligate intracellular bacteria infect and kill white blood cells the average reported annual incidence is on the order of 2 3 cases per million people
ehrlichiosis ˌɛərlᵻkiˈoʊsᵻs also known as canine rickettsiosis canine hemorrhagic fever canine typhus tracker dog disease and tropical canine pancytopenia is a tick borne disease of dogs usually caused by the organism ehrlichia canis ehrlichia canis is the pathogen of animals humans can become infected by e canis and other species after tick exposure german shepherd dogs are thought to be susceptible to a particularly severe form of the disease other breeds generally have milder clinical signs cats can also be infected
ehrlichiosis ewingii infection is an infectious disease caused by an intracellular bacteria ehrlichia ewingii the infection is transmitted to humans by the tick amblyomma americanum this tick can also transmit ehrlichia chaffeensis the bacteria that causes human monocytic ehrlichiosis hme
eidetic memory aɪˈdɛtɪk sometimes called photographic memory is an ability to vividly recall images from memory after only a few instances of exposure with high precision for a brief time after exposure without using a mnemonic device although the terms eidetic memory and photographic memory may be used interchangeably they are also distinguished with eidetic memory referring to the ability to view memories like photographs for a few minutes and photographic memory referring to the ability to recall page or text numbers or similar in great detail in the case of distinguishing the concepts eidetic memory has been documented while photographic memory is a popular culture myth that has never been demonstrated to exist eidetic images occur in a small number of children and generally are not found in adults the word eidetic comes from the greek word εἶδος pronounced êːdos eidos seen
the eifeler regel eifel rule is a linguistic phenomenon originally documented in the dialects of the eifel region in the far west of germany during the late 19 th century the rule describes a phonological process in the languages which causes the deletion of final n in certain contexts and may be reflected in spelling more generally called n apocope it appears to varying extents in all dialects of the western group of high german including west central german notably luxembourgish colognian and hessian high franconian and alemannic and excludes all dialects of the eastern group such as austro bavarian and the colonial dialects east of the elbe saale line including standard german and yiddish n apocope is a linguistic change originating in speech during the middle high german period
in linear algebra the eigengap of a linear operator is the difference between two successive eigenvalues where eigenvalues are sorted in ascending order the davis – kahan theorem named after chandler davis and william kahan uses the eigengap to show how eigenspaces of an operator change under perturbation in spectral clustering the eigengap is often referred to as the spectral gap although the spectral gap may often be defined in a broader sense than that of the eigengap
the eight queens puzzle is the problem of placing eight chess queens on an 8 × 8 chessboard so that no two queens threaten each other thus a solution requires that no two queens share the same row column or diagonal the eight queens puzzle is an example of the more general n queens problem of placing n non attacking queens on an n × n chessboard for which solutions exist for all natural numbers n with the exception of n 2 and n 3
eiken syndrome is a rare autosomal bone dysplasia with a skeletal phenotype which has been described in a unique consanguineous family where it segregates as a recessive trait
the einstein – de haas effect or the richardson effect after owen willans richardson is a physical phenomenon delineated by albert einstein and wander johannes de haas in the mid 1910 s that exposes a relationship between magnetism angular momentum and the spin of elementary particles wander johannes de haas son rowan de haas was also a major contributor to the theory applying its principles to the engineering industry specifically rowan s contributions had a transformative effect on the steel manufacturing industry in the early 20 th century
eisenmenger s syndrome or es eisenmenger s reaction eisenmenger physiology or tardive cyanosis is defined as the process in which a long standing left to right cardiac shunt caused by a congenital heart defect typically by a ventricular septal defect atrial septal defect or less commonly patent ductus arteriosus causes pulmonary hypertension and eventual reversal of the shunt into a cyanotic right to left shunt because of the advent of fetal screening with echocardiography early in life the incidence of heart defects progressing to eisenmenger s has decreased eisenmenger s syndrome in a pregnant mother can cause serious complications though successful delivery has been reported maternal mortality ranges from 30 to 60 and may be attributed to fainting spells thromboembolism hypovolemia hemoptysis or preeclampsia most deaths occur either during or within the first weeks after delivery pregnant women with eisenmenger syndrome should be hospitalized after the 20 th week of pregnancy or earlier if clinical deterioration occurs
ejaculatory duct obstruction edo is a congenital or acquired pathological condition which is characterized by the obstruction of one or both ejaculatory ducts thus the efflux of most constituents of semen is not possible it is a cause of male infertility and or pelvic pain ejaculatory duct obstruction must not be confused with an obstruction of the vas deferens
the el farol bar problem is a problem in game theory based on a bar in santa fe new mexico it was created in 1994 by w brian arthur the problem without the name of el farol bar was formulated and solved dynamically six years earlier by b a huberman and t hogg in the ecology of computation studies in computer science and artificial intelligence north holland publisher page 99 1988 the problem is as follows there is a particular finite population of people every thursday night all of these people want to go to the el farol bar however the el farol is quite small and it s no fun to go there if it s too crowded so much so in fact that the preferences of the population can be described as follows if less than 60 of the population go to the bar they ll all have a better time than if they stayed at home if more than 60 of the population go to the bar they ll all have a worse time than if they stayed at home unfortunately it is necessary for everyone to decide at the same time whether they will go to the bar or not they cannot wait and see how many others go on a particular thursday before deciding to go themselves on that thursday one aspect of the problem is that no matter what method each person uses to decide if they will go to the bar or not if everyone uses the same pure strategy it is guaranteed to fail if everyone uses the same deterministic method then if that method suggests that the bar will not be crowded everyone will go and thus it will be crowded likewise if that method suggests that the bar will be crowded nobody will go and thus it will not be crowded often the solution to such problems in game theory is to permit each player to use a mixed strategy where a choice is made with a particular probability in the case of the single stage el farol bar problem there exists a unique symmetric nash equilibrium mixed strategy where all players choose to go to the bar with a certain probability that is a function of the number of players the threshold for crowdedness and the relative utility of going to a crowded or an uncrowded bar compared to staying home there are also multiple nash equilibria where one or more players use a pure strategy but these equilibria are not symmetric several variants are considered in game theory evolving by herbert gintis in some variants of the problem the people are allowed to communicate with each other before deciding to go to the bar however they are not required to tell the truth
elaidinization is a chemical reaction which alters the orientation of double bonds from cis to trans it is most often performed on fats and oils to increase both the melting point and the shelf life without reducing the degree of unsaturation the typical product of elaidinization is trans fat
in physics elasticity from greek ἐλαστός ductible is the ability of a body to resist a distorting influence or stress and to return to its original size and shape when the stress is removed solid objects will deform when forces are applied on them if the material is elastic the object will return to its initial shape and size when these forces are removed the physical reasons for elastic behavior can be quite different for different materials in metals the atomic lattice changes size and shape when forces are applied energy is added to the system when forces are removed the lattice goes back to the original lower energy state for rubbers and other polymers elasticity is caused by the stretching of polymer chains when forces are applied perfect elasticity is an approximation of the real world and few materials remain purely elastic even after very small deformations in engineering the amount of elasticity of a material is determined by two types of material parameter the first type of material parameter is called a modulus which measures the amount of force per unit area stress needed to achieve a given amount of deformation the units of modulus are pascals pa or pounds of force per square inch psi also lbf in 2 a higher modulus typically indicates that the material is harder to deform the second type of parameter measures the elastic limit the limit can be a stress beyond which the material no longer behaves elastic and deformation of the material will take place if the stress is released the material will elastically return to a permanent deformed shape instead of the original shape when describing the relative elasticities of two materials both the modulus and the elastic limit have to be considered rubbers typically have a low modulus and tend to stretch a lot that is they have a high elastic limit and so appear more elastic than metals high modulus and low elastic limit in everyday experience of two rubber materials with the same elastic limit the one with a lower modulus will appear to be more elastic
elasto capillarity is the ability of capillary force to deform an elastic material from the viewpoint of mechanics elastocapillarity phenomena essentially involve competition between the elastic strain energy in the bulk and the energy on the surfaces interfaces in the modeling of these phenomena some challenging issues are among others the exact characterization of energies at the micro scale the solution of strongly nonlinear problems of structures with large deformation and moving boundary conditions and instability of either solid structures or droplets films the capillary forces are generally negligible in the analysis of macroscopic structures but often play a significant role in many phenomena at small scales
elastofibroma also called elastofibroma dorsi is an ill defined fibroelastic tumor like condition made up of enlarged and irregular elastic fibers
elastosis perforans serpiginosa is a unique perforating disorder characterized by transepidermal elimination of elastic fibers and distinctive clinical lesions which are serpiginous in distribution and can be associated with specific diseases
elbow dysplasia is a condition involving multiple developmental abnormalities of the elbow joint in the dog specifically the growth of cartilage or the structures surrounding it these abnormalities known as primary lesions give rise to osteoarthritic processes elbow dysplasia is a common condition of certain breeds of dogs most primary lesions are related to osteochondrosis which is a disease of the joint cartilage and specifically osteochondritis dissecans ocd or od the separation of a flap of cartilage on the joint surface other common causes of elbow dysplasia included ununited anconeal process uap and fragmented or ununited medial coronoid process fcp or fmcp osteochondritis dissecans is difficult to diagnose clinically as the animal may only exhibit an unusual gait consequently ocd may be masked by or misdiagnosed as other skeletal and joint conditions such as hip dysplasia the problem develops in puppyhood although often subclinically and there may be pain or stiffness discomfort on extension or other compensating characteristics diagnosis generally depends on x rays arthroscopy or mri scans while cases of ocd of the stifle go undetected and heal spontaneously others are exhibited in acute lameness surgery is recommended once the animal has been deemed lame before then non surgical control is usually used
the elbs persulfate oxidation is the organic reaction of phenols with alkaline potassium persulfate to form para diphenols the elbs persulfate oxidation several reviews have been published
the elbs reaction is an organic reaction describing the pyrolysis of an ortho methyl substituted benzophenone to condensed polyaromatic the reaction is named after its inventor the german chemist karl elbs also responsible for the elbs oxidation the reaction was published in 1884 elbs however did not correctly interpret the reaction product due to a lack of knowledge about naphthalene structure
an electric potential also called the electric field potential or the electrostatic potential is the amount of electric potential energy that a unitary point electric charge would have if located at any point in space and is equal to the work done by an external agent in carrying a unit of positive charge from the arbitrarily chosen reference point usually infinity to that point without any acceleration according to theoretical electromagnetics electric potential is a scalar quantity denoted by v equal to the electric potential energy of any charged particle at any location measured in joules divided by the charge of that particle measured in coulombs by dividing out the charge on the particle a remainder is obtained that is a property of the electric field itself this value can be calculated in either a static time invariant or a dynamic varying with time electric field at a specific time in units of joules per coulomb j c − 1 or volts v the electric potential at infinity is assumed to be zero a generalized electric scalar potential is also used in electrodynamics when time varying electromagnetic fields are present but this can not be so simply calculated the electric potential and the magnetic vector potential together form a four vector so that the two kinds of potential are mixed under lorentz transformations
electric shock is the physiological reaction or injury caused by electric current passing through the human body typically the expression is used to describe an injurious exposure to electricity it occurs upon contact of a human body part with any source of electricity that causes a sufficient current through the skin muscles or hair very small currents can be imperceptible larger current passing through the body may make it impossible for a shock victim to let go of an energized object still larger currents can cause fibrillation of the heart and damage to tissues death caused by an electric shock is called electrocution an electrical injury has many consequences to a body as the electrical currents can travel through the nervous system and burn out tissue in patches along the way this can leave bizarre symptoms anywhere on the body and may lead to complex regional pain syndrome wiring or other metalwork which is at a hazardous voltage which can constitute a risk of electric shock is called live as in live wire shocks can be caused by direct or indirect contact contact with an exposed conductive part under fault conditions is called indirect contact iec requires certain degrees of ingress protection against direct contact indirect contact protections can be achieved by earthed equipotential bonding and automatic disconnection of supply by using residual current devices for example
electric sonic amplitude is an electroacoustic phenomenon that is the reverse to colloid vibration current it occurs in colloids emulsions and other heterogeneous fluids under the influence of an oscillating electric field this field moves particles relative to the liquid which generates ultrasound electric sonic amplitude was experimentally discovered by oja and co authors in early 1980 s it is also widely used for characterizing zeta potential in dispersions and emulsions there is review of the theory of this effect its experimental verification and multiple applications published by hunter
electrical alternans is an electrocardiographic phenomenon of alternation of qrs complex amplitude or axis between beats and a possible wandering base line it is seen in cardiac tamponade and severe pericardial effusion and is thought to be related to changes in the ventricular electrical axis due to fluid in the pericardium as the heart essentially wobbles in the fluid filled pericardial sac this phenomenon was also redemonstrated in the literature by osman md and jehangir md in a patient with percardial temponade from a malignant pericardial effusion the echocardiogram of the heart demonstrated the characteristic swinging along with alternating voltage on the ecg generally electrical alternans can be seen with tamponade and narrow av junctional reenterant tachycardia with an accessory pathway such as wpw syndrome a similar phenomenon pseudo alternans can be seen in bigeminal pvc in the pr interval alternans pre excitation and alternans bundle branch block for the most part however the most serious condition to rule out is tamponade electrical alternans with sinus tachycardia is a highly specific sign for large pericardial effusion this is due to the swinging motion of the heart in the pericardial cavity causing a beat to beat variation in qrs axis and amplitude patients with cardiac tamponade and hemodynamic compromise should have emergency pericardiocentesis
electrical mobility is the ability of charged particles such as electrons or protons to move through a medium in response to an electric field that is pulling them the separation of ions according to their mobility in gas phase is called ion mobility spectrometry in liquid phase it is called electrophoresis
in electrical engineering treeing is an electrical pre breakdown phenomenon in solid insulation it is a damaging process due to partial discharges and progresses through the stressed dielectric insulation in a path resembling the branches of a tree treeing of solid high voltage cable insulation is a common breakdown mechanism and source of electrical faults in underground power cables
electricity provider switching is the ability of power consumers to have an option — or the power to choose — their electricity provider in a deregulated electricity market as permitted by a state public utilities governing body
electroadhesion is the electrostatic effect of astriction between two surfaces subjected to an electrical field applications include the retention of paper on plotter surfaces astrictive robotic prehension electrostatic grippers etc clamping pressures in the range of 0 5 to 1 5 n cm 2 0 8 to 2 3 psi have been claimed an electroadhesive pad consists of conductive electrodes placed upon a polymer substrate when alternate positive and negative charges are induced on adjacent electrodes the resulting electric field sets up opposite charges on the surface that the pad touches and thus causes electrostatic adhesion between the electrodes and the induced charges in the touched surface material electroadhesion can be loosely divided into two basic forms that which concerns the prehension of electrically conducting materials where the general laws of capacitance hold d e ε and that used with electrically insulating subjects where the more advanced theory of electrostatics d e ε p applies
the electrocaloric effect is a phenomenon in which a material shows a reversible temperature change under an applied electric field it is often considered to be the physical inverse of the pyroelectric effect it should not be confused with the thermoelectric effect specifically the peltier effect in which a temperature difference occurs when a current is driven through an electric junction with two dissimilar conductors the underlying mechanism of the effect is not fully established in particular different textbooks give conflicting explanations however as with any isolated adiabatic temperature change the effect comes from the voltage raising or lowering the entropy of the system the magnetocaloric effect is an analogous but better known and understood phenomenon electrocaloric materials were the focus of significant scientific interest in the 1960 s and 1970 s but were not commercially exploited as the electrocaloric effects were insufficient for practical applications the highest response being 2 5 degrees celsius under an applied potential of 750 volts in march 2006 it was reported in the journal science that thin films of the material pzt a mixture of lead titanium oxygen and zirconium showed the strongest electrocalorific response yet reported with the materials cooling down by as much as 12 k 12 ° c for an electric field change of 480 kv cm at an ambient temperature of 220 ° c 430 ° f the device structure consisted of a thin film pzt on top of a much thicker substrate but the figure of 12 k represents the cooling of the thin film only the net cooling of such a device would be lower than 12 k due to the heat capacity of the substrate to which it is attached along the same lines in 2008 it was shown that a ferroelectric polymer can also achieve 12 k of cooling nearer room temperature with these new larger responses practical applications may be more likely such as in computer cooling
electrochromism is the phenomenon displayed by some materials of reversibly changing colour by using bursts of charge to cause electrochemical redox reactions in electrochromic materials various types of materials and structures can be used to construct electrochromic devices depending on the specific applications transition metal oxides are a large family of materials possessing various interesting properties in the field of electrochromism among them tungsten oxide wo 3 has been the most extensively studied material used in the production of electrochromic windows or smart glass and more recently electrochromic displays on paper substrate as anti counterfeiting systems integrated on packaging nio materials have been widely studied as counter electrodes for complementary electrochromic devices in particular smart windows the world leading institutions on nio efforts include national renewable energy laboratory and uppsala university another example of an electrochromic material is polyaniline which can be formed either by the electrochemical or chemical oxidation of aniline if an electrode is immersed in hydrochloric acid which contains a small concentration of aniline then a film of polyaniline can be grown on the electrode depending on the oxidation state polyaniline can either be pale yellow or dark green black other electrochromic materials that have found technological application include the viologens and polyoxotungstates as the color change is persistent and energy need only be applied to affect a change electrochromic materials are used to control the amount of light and heat allowed to pass through windows smart windows one popular application is in the automobile industry where it is used to automatically tint rear view mirrors in various lighting conditions viologen is used in conjunction with titanium dioxide tio 2 in the creation of small digital displays it is hoped that these displays will replace liquid crystal displays as the viologen which is typically dark blue has a high contrast compared to the bright white of the titania thereby providing the display high visibility ice 3 high speed trains use electrochromatic glass panels between the passenger compartment and the driver s cabin the standard mode is clear and can be switched by the driver to frosted translucent mainly to conceal unwanted sights from passengers view for example in the case of human obstacles electrochromic windows are used in the boeing 787 dreamliner in 2014 cnrs french national centre for scientific research researchers in bordeaux have resulted in reducing the number of layers of classic architecture from 7 layer to 4 and also 3 layer structures
electrohydrodynamic droplet deformation is a phenomenon that occurs when liquid droplets suspended in a second immiscible liquid are exposed to an oscillating electric field under these conditions the droplet will periodically deform between prolate and oblate ellipsoidal shapes the characteristic frequency and magnitude of the deformation is determined by a balance of electrodynamic hydrodynamic and capillary stresses acting on the droplet interface this phenomenon has been studied extensively both mathematically and experimentally because of the complex fluid dynamics that occur characterization and modulation of electrodynamic droplet deformation is of particular interest for engineering applications because of the growing need to improve the performance of complex industrial processes e g two phase cooling crude oil demulsification the primary advantage of using oscillatory droplet deformation to improve these engineering processes is that the phenomenon does not require sophisticated machinery or the introduction of heat sources this effectively means that improving performance via oscillatory droplet deformation is simple and in no way diminishes the effectiveness of the existing engineering system
electroluminescence el is an optical phenomenon and electrical phenomenon in which a material emits light in response to the passage of an electric current or to a strong electric field this is distinct from black body light emission resulting from heat incandescence from a chemical reaction chemiluminescence sound sonoluminescence or other mechanical action mechanoluminescence
an electromagnetic four potential is a relativistic vector function from which the electromagnetic field can be derived it combines both an electric scalar potential and a magnetic vector potential into a single four vector as measured in a given frame of reference and for a given gauge the first component of the electromagnetic four potential is the electric scalar potential and the other three components make up the magnetic vector potential while both the scalar and vector potential depend upon the frame the electromagnetic four potential is lorentz covariant like other potentials many different electromagnetic four potentials correspond to the same electromagnetic field depending upon the choice of gauge in this article index notation and the minkowski metric − − − will be used see also ricci calculus covariance and contravariance of vectors and raising and lowering indices for more details on notation formulae are given in si units and gaussian cgs units
electromagnetic interference emi also called radio frequency interference rfi when in the radio frequency spectrum is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction electrostatic coupling or conduction the disturbance may degrade the performance of the circuit or even stop it from functioning in the case of a data path these effects can range from an increase in error rate to a total loss of the data both man made and natural sources generate changing electrical currents and voltages that can cause emi automobile ignition systems cell phones thunderstorms the sun and the northern lights emi frequently affects am radios it can also affect cell phones fm radios and televisions emi can be used intentionally for radio jamming as in electronic warfare
in telecommunication electromagnetic survivability is the ability of a system subsystem or equipment to resume functioning without evidence of degradation following temporary exposure to an adverse electromagnetic environment the system subsystem or equipment performance may be degraded during exposure to the adverse electromagnetic environment but the system will not experience permanent damage such as component burnout that will prevent proper operation when the adverse electromagnetic environment is removed
electromagnetically induced grating eig is an optical interference phenomenon where an interference pattern is used to build a dynamic spatial diffraction grating in matter eigs are dynamically created by light interference on optically resonant materials and rely on population inversion and or optical coherence properties of the material they were first demonstrated with population gratings on atoms eigs can be used for purposes of atomic molecular velocimetry to probe the material optical properties such as coherence and population life times and switching and routing of light related but different effects are thermally induced gratings and photolithography gratings
the electron cloud effect is a phenomenon that occurs in particle accelerators and reduces the quality of the particle beam
the electron refractive effect or electron induced permittivity modification eipm is an electro optic effect observed in some crystals and amorphous materials such as chalcogenide glasses and oxides where the permittivity reduces or increases when the material is illuminated by high energy electrons typically from an transmission electron microscope or scanning electron microscope the effect is non linear and reversible the effect was observed by n normand and o normand who observed that the permittivity of chalcogenide glass increased by as much as 5 when irradiated with an electron gun in the 30 kev range they also noticed that the change was accompanied by a change in the thickness of the film recently san roman alerigi anjum and ooi demonstrated that the permittivity of chalcogenide thin films could also be reduced by as much as 50 when the sample was illuminated by 300 kev electrons moreover they also demonstrated that the electron induced permittivity modification was reversible
in physics chemistry and electronic engineering an electron hole is the lack of an electron at a position where one could exist in an atom or atomic lattice it is different from the positron which is an actual particle of antimatter see also dirac sea if an electron is excited into a higher state it leaves a hole in its old state this meaning is used in auger electron spectroscopy and other x ray techniques in computational chemistry and to explain the low electron electron scattering rate in crystals metals semiconductors in crystals electronic band structure calculations lead to an effective mass for the electrons which typically is negative at the top of a band the negative mass is an unintuitive concept and in these situations a more familiar picture is found by considering a positive charge with a positive mass
electron precipitation also called energetic electron precipitation or eep is an atmospheric phenomenon that occurs when previously trapped electrons enter the earth s atmosphere thus creating communications interferences and other disturbances electrons are trapped in the van allen radiation belt by earth s magnetic fields and begin to spiral around field lines in the radiation belt they may remain there for an indefinite period of time in some cases years when broadband very low frequency vlf waves propagate the radiation belts the electrons exit the radiation belt and precipitate or travel into the ionosphere a region of earth s atmosphere where the electrons will collide with ions electron precipitation is regularly linked to ozone depletion it is often caused by lighting strikes or vlf transmitters
electron wake is the disturbance left after a high energy charged particle passesthrough condensed matter or plasma ions passing through can introduce periodic oscillations in the crystal lattice or plasma wave with the characteristic frequency of the crystal or plasma frequency interactions of the field created by these oscillations with the charged particle field alternate from constructive interference to destructive interference producing alternating waves of electric field and displacement the frequency of the wake field is determined by the nature of the penetrated matter and the period of the wake field is directly proportional to the speed of the incoming charged particle the amplitude of the first wake wave is the most important as it produces a braking force on the charged particle eventually slowing it down wake fields also can capture and guide lightweight ions or positrons in the direction perpendicular to the wake the larger the speed of the original charged particle the larger the angle between the initial particle s velocity and the captured ion s velocity
e hr is a function of hr that is concerned with the use management and regulation of electronic information and processes within an organization e hr is different from e hrm electronic human resource management and hris human resource information system which are uses of technology more specifically e hrm is a system that allows management and employees access to human resource related information and services through an organization s intranet or web portal hris refers to enterprise resource planning software that streamlines human resource functions such as payroll in contrast e hr is a function of human resources that requires cross functional knowledge and collaboration between multiple departments most notably human resources and information technology
electronic oscillation is the continuous recurrence of the same electrical periodic waveform the recurrence may be in the form of a varying voltage or a varying current the waveform may be sinusoidal or some other shape when its magnitude is plotted against the duration of its cycle electronic oscillation may be intentionally caused as in devices designed as oscillators or it may be the result of unintentional positive feedback from the output of an electronic device to its input the latter appears often in feedback amplifiers such as operational amplifiers that do not have sufficient gain or phase margins in this case the oscillation often interferes with or compromises the amplifier s intended function and is known as parasitic oscillation
electronic process of law or electronic lawsuit is an up to date phenomenon concerning the use of computer programs in courts and public departments in sue activities it is a theme of worldwide scope in portugal it is known as the concept of processo eletrônico in india known as electronic judicial resource management in france it is called dématerialisation du processus judiciaire it is a polissemic expression related to interdisciplinarity between the information technologies and branches of law that govern the lawsuits that take place in departments of public administration more specifically the control follow up searches and practices of juridical acts helped by computer systems its universal definition can be found in various sources
in organic chemistry an electrophilic addition reaction is an addition reaction where in a chemical compound a π bond is broken and two new σ bonds are formed the substrate of an electrophilic addition reaction must have a double bond or triple bond the driving force for this reaction is the formation of an electrophile x that forms a covalent bond with an electron rich unsaturated c c bond the positive charge on x is transferred to the carbon carbon bond forming a carbocation during the formation of the c x bond electrophilic addition mechanism in step 2 of an electrophilic addition the positively charged intermediate combines with y that is electron rich and usually an anion to form the second covalent bond step 2 is the same nucleophilic attack process found in an sn 1 reaction the exact nature of the electrophile and the nature of the positively charged intermediate are not always clear and depend on reactants and reaction conditions in all asymmetric addition reactions to carbon regioselectivity is important and often determined by markovnikov s rule organoborane compounds give anti markovnikov additions electrophilic attack to an aromatic system results in electrophilic aromatic substitution rather than an addition reaction
electrophilic aromatic substitution sear is an organic reaction in which an atom that is attached to an aromatic system usually hydrogen is replaced by an electrophile some of the most important electrophilic aromatic substitutions are aromatic nitration aromatic halogenation aromatic sulfonation and acylation and alkylating friedel – crafts reactions
electrophilic substitution reactions are chemical reactions in which an electrophile displaces a functional group in a compound which is typically but not always a hydrogen atom electrophilic aromatic substitution reactions are characteristic of aromatic compounds and are important ways of introducing functional groups onto benzene rings the other main type of electrophilic substitution reaction is an electrophilic aliphatic substitution reaction
electroreception is the biological ability to perceive natural electrical stimuli it has been observed almost exclusively in aquatic or amphibious animals since salt water is a much better conductor than air the currently known exceptions being echidnas cockroaches and bees electroreception is used in detecting objects and for electrocommunication
elejalde syndrome also known as griscelli syndrome type 1 is a rare autosomal recessive syndrome consisting of moderate pigment dilution profound primary neurologic defects no immune defects and hair with metallic silvery sheen it is associated with myo 5 a
in mathematics an elementary function is a function of one variable which is the composition of a finite number of arithmetic operations – × ÷ exponentials logarithms constants and solutions of algebraic equations a generalization of nth roots the elementary functions include the trigonometric and hyperbolic functions and their inverses as they are expressible with complex exponentials and logarithms it follows directly from the definition that the set of elementary functions is closed under arithmetic operations and composition it is also closed under differentiation it is not closed under limits and infinite sums importantly the elementary functions are not closed under integration as shown by liouville s theorem see nonelementary integral the liouvillian functions are defined as the elementary functions and recursively the integrals of the liouvillian functions some elementary functions such as roots logarithms or inverse trigonometric functions are not entire functions and may be multivalued elementary functions were introduced by joseph liouville in a series of papers from 1833 to 1841 an algebraic treatment of elementary functions was started by joseph fels ritt in the 1930 s
elephantiasis is a symptom of a variety of diseases where parts of a person s body swell to massive proportions some conditions that have this symptom include elephantiasis nostras due to longstanding chronic lymphangitis elephantiasis tropica or lymphatic filariasis caused by a number of parasitic worms particularly wuchereria bancrofti nonfilarial elephantiasis or podoconiosis an immune disease affecting the lymph vessels elephantiasis grade 4 lymphedema genital elephantiasis end result of lymphogranuloma venereum proteus syndrome the genetic disorder of the so called elephant man
elephantiasis nostras is a cutaneous condition a final hypertrophic fibrosis following longstanding chronic lymphangitis
elevated alkaline phosphatase describes the situation where the levels of alkaline phosphatase alp exceed the reference range this group of enzymes has a low substrate specificity and catalyzes the hydrolysis of phosphate esters in an acidic environment the major function of alkaline phosphatase is transporting across cell membranes alkaline phosphatases are present in many human tissues including bone intestine kidney liver placenta and white blood cells damage to these tissues causes the release of alp into the bloodstream elevated levels can be detected through a blood test elevated alkaline phosphate is associated with certain medical conditions or syndromes e g hyperphosphatasia with mental retardation syndrome hpmrs it serves as a significant indication for certain medical conditions diseases and syndromes if the reason for alkaline phosphatase is unknown isoenzyme studies using electrophoresis can confirm the source of the alp heat stability also distinguishes bone and liver isoenzymes bone burns liver lasts
elevated alpha fetoprotein refers to a state where alpha fetoprotein levels are outside of the reference range there are two categories of afp tests tests performed on serum blood plasma and tests performed on amniotic fluid tests performed on serum are further categorized by the reason for performing the test maternal serum adult tumor marker and pediatric tumor marker
in medicine the presence of elevated transaminases commonly the transaminases alanine transaminase alt and aspartate transaminase ast may be an indicator of liver damage other terms employed include transaminasemia and transaminitis although some sources consider the latter pathologically meaningless normal ranges for both alt and ast are 8 40 u l with mild transaminesemia noted to the upward numerical limit of 250 u l drug induced increases such as that found with the use of anti tuberculosis agents such as isoniazid are limited typically to below 100 u l for either alt or ast cirrhosis of the liver or fulminant liver failure secondary to hepatitis commonly reach values for both alt and ast in the 1000 u l range elevated transaminases that persist less than six months are termed acute in nature and those values that persist for six months or more are termed chronic in nature
elevational diversity gradient edg is an ecological pattern where trends in biodiversity occur at different elevations the edg states that species richness tends to increase as elevation increases up to a certain point creating a diversity bulge at middle elevations there have been multiple hypotheses proposed for explaining the edg none of which accurately describe the phenomenon in full a similar pattern known as the latitudinal diversity gradient describes an increase in biodiversity from the poles to the equator while the edg generally follows the ldg i e high elevations in tropical regions have greater biodiversity than high elevations in temperate regions the ldg does not account for elevational changes
elevenses pronunciation ᵻˈlɛvənzᵻz is a short break taken at around 11 a m to consume a drink or snack of some sort the name and details vary between countries
elfshot or elf shot is a medical condition described in anglo saxon medical texts notably wið færstice and believed to be caused by invisible elves shooting invisible arrows at a person or animal causing sudden shooting pains localised to a particular area of the body modern dignoses might include rheumatism arthritis muscle stitches or cramps similar concepts existed in other northern european cultures belief or at least references to elfshot persisted into the 20 th century also in scotland though more modern elves seem to have concentrated their attentions on animals in rural areas country folk would sometimes find small arrowheads the remains of neolithic or mesolithic flints or naturally occurring spear shaped stones the prevention or curing of elfshot comes from using a charm against the sudden stitch the three plants used in the cure are feverfew red nettles and waybread all have vaguely spear shaped leaves which may have suggested their use as a remedy for pains attributed to elf arrows
in most organic elimination reactions at least one hydrogen is lost to form the double bond the unsaturation of the molecule increases it is also possible that a molecule undergoes reductive elimination by which the valence of an atom in the molecule decreases by two though this is more common in inorganic chemistry an important class of elimination reactions is those involving alkyl halides with good leaving groups reacting with a lewis base to form an alkene elimination may be considered the reverse of an addition reaction when the substrate is asymmetric regioselectivity is determined by zaitsev s rule or through hofmann elimination if the carbon with the most substituted hydrogen is inaccessible
in complex analysis an elliptic function is a meromorphic function that is periodic in two directions just as a periodic function of a real variable is defined by its values on an interval an elliptic function is determined by its values on a fundamental parallelogram which then repeat in a lattice such a doubly periodic function cannot be holomorphic as it would then be a bounded entire function and by liouville s theorem every such function must be constant in fact an elliptic function must have at least two poles counting multiplicity in a fundamental parallelogram as it is easy to show using the periodicity that a contour integral around its boundary must vanish implying that the residues of all simple poles must cancel historically elliptic functions were first discovered by niels henrik abel as inverse functions of elliptic integrals and their theory was improved by carl gustav jacobi these in turn were studied in connection with the problem of the arc length of an ellipse whence the name derives jacobi s elliptic functions have found numerous applications in physics and were used by jacobi to prove some results in elementary number theory a more complete study of elliptic functions was later undertaken by karl weierstrass who found a simple elliptic function in terms of which all the others could be expressed besides their practical use in the evaluation of integrals and the explicit solution of certain differential equations they have deep connections with elliptic curves and modular forms
ellis – van creveld syndrome also called chondroectodermal dysplasia or mesoectodermal dysplasia but see nomenclature section below is a rare genetic disorder of the skeletal dysplasia type
elm yellows is a plant disease of elm trees that is spread by leafhoppers or by root grafts elm yellows also known as elm phloem necrosis is very aggressive with no known cure elm yellows occurs in the eastern united states and southern ontario in canada it is caused by phytoplasmas which infect the phloem inner bark of the tree similar phytoplasmas also known confusingly as elm yellows also occur in europe infection and death of the phloem effectively girdles the tree and stops the flow of water and nutrients the disease affects both wild growing and cultivated trees
an email loop is an infinite loop phenomenon resulting from mail servers scripts or email clients that generate automatic replies or responses if one such automatic response triggers another automatic response on the other side an email loop is created the process can continue until one mailbox is full or reaches its mail sending limit in theory the email loop could last indefinitely email loops may be caused accidentally or maliciously causing denial of service although rare email loops involving more than two participants can also occur email loops are not as common today as in the past due to changes to email software both on the client side and the server side that prevent automatic replies to vacation responses and bounced mail responses
derivative 22 syndrome or der 22 is a rare disorder associated with multiple congenital anomalies including profound mental retardation preauricular skin tags or pits and conotruncal heart defects it can occur in offspring of carriers of the constitutional chromosomal translocation t 11 22 q 23 q 11 owing to a 3 1 meiotic malsegregation event resulting in partial trisomy of chromosomes 11 and 22 an unbalanced translocation between chromosomes 11 22 is described as emanuel syndrome it was characterized in 1980
embedment is a phenomenon in mechanical engineering in which the surfaces between mechanical members of a loaded joint embed it can lead to failure by fatigue as described below and is of particular concern when considering the design of critical fastener joints
an embolism is the lodging of an embolus a blockage causing piece of material inside a blood vessel the embolus may be a blood clot thrombus a fat globule a bubble of air or other gas gas embolism or foreign material an embolism can cause partial or total blockage of blood flow in the affected vessel such a blockage a vascular occlusion may affect a part of the body distant from where the embolus originated an embolism in which the embolus is a piece of thrombus is called a thromboembolism thrombosis the process of thrombus formation often leads to thromboembolism an embolism is usually a pathologic event that is part of illness or injury sometimes it is created intentionally for a therapeutic reason such as to stop bleeding or to kill a cancerous tumor by stopping its blood supply such therapy is called embolization
embrittlement is a loss of ductility of a material making it brittle various materials have different mechanisms of embrittlement hydrogen embrittlement is the effect of hydrogen absorption on some metals and alloys sulfide stress cracking is the embrittlement caused by absorption of hydrogen sulfide liquid metal embrittlement lme is the embrittlement caused by liquid metals metal induced embrittlement mie is the embrittlement caused by diffusion of atoms of metal either solid or liquid into the material neutron radiation causes embrittlement of some materials neutron induced swelling and buildup of wigner energy this is a process especially important for neutron moderators and nuclear reactor vessels see ductility the primary embrittlement mechanism of plastics is gradual loss of plasticizers usually by overheating or aging the primary embrittlement mechanism of asphalt is by oxidation which is most severe in warmer climates asphalt pavement embrittlement can lead to various forms of cracking patterns including longitudinal transverse and block hexagonal asphalt oxidation is related to polymer degradation as these materials bear similarities in their chemical composition
embryo quality is the ability of an embryo to perform successfully in terms of conferring a high pregnancy rate and or resulting in a healthy person embryo profiling is the estimation of embryo quality by qualification and or quantification of various parameters estimations of embryo quality guides the choice in embryo selection in in vitro fertilization in general embryo profiling for prediction of pregnancy rates focuses mainly on visual profiles and short term biomarkers including expression of rna and proteins preferably in the surroundings of embryos to avoid any damage to them on the other hand embryo profiling for health prediction puts more focus on the genome and where there is a risk of a genetic disorder it more often involves cell sampling from the embryo for preimplantation genetic diagnosis
embryocardia is a condition in which the two heart sounds s 1 and s 2 that produce the typical lubb dubb sound of the heart becomes indistinguishable and equally spaced thus the normal lubb dubb rhythm of the heart becomes a tic toc rhythm resembling the heart sounds of a fetus this condition is observed in myocarditis
embryonal carcinoma is a relatively uncommon type of germ cell tumour that occurs in the ovaries and testes
embryonal rhabdomyosarcoma erms is a rare histological form of cancer of connective tissue wherein the mesenchymally derived malignant cells resemble the primitive developing skeletal muscle of the embryo it is the most common soft tissue sarcoma occurring in children
emergence delirium sometimes referred to as agitated emergence emergence agitation emergence excitement or postanesthetic excitement is a condition in which emergence from general anesthesia is accompanied by psychomotor agitation some see a relation to pavor nocturnus while other see a relation to the excitement stage of anesthesia
an emergency exit in a structure is a special exit for emergencies such as a fire the combined use of regular and special exits allows for faster evacuation while it also provides an alternative if the route to the regular exit is blocked by fire etc it is usually a strategically located e g in a stairwell hallway or other likely place outward opening door with a crash bar on it and with exit signs leading to it the name is a reference to when they are frequently used however a fire exit can also be a main doorway in or out a fire escape is a special kind of emergency exit mounted to the outside of a building
emergency rations are items of food and drink that a person stores and relies on in case of an emergency emergency food supplies can be purchased for camping trips or wilderness adventures these supplies are meant to last for several days many people also purchase long shelf life emergency food in case of natural disasters or other emergency situations the food can come in the form of a powder freeze dried smoked or salted the rations are to help people survive until help arrives and are often carried while hill walking or mountaineering because of the risk of being stranded by an accident in some organised events such as ten tors it is obligatory to carry emergency rations emergency rations are often carried by camping enthusiasts especially back pack campers who are more likely to be far from food supplies emergency foodstuffs are usually high in caloric content and sometimes also in nutritional content typical emergency foodstuffs are high calorie foods such as candy bars nutritional bars energy or sports bars hard bread or biscuit dried meat such as jerky and dried fruit if water is available rations with little water content are lighter to carry emergency rations are generally carried on the person by people on foot in case of becoming lost or separated from normal food supplies water or other drinks are carried if water is not readily available from the environment
an emerging infectious disease eid is an infectious disease whose incidence has increased in the past 20 years and could increase in the near future emerging infections account for at least 12 of all human pathogens eids are caused by newly identified species or strains e g severe acute respiratory syndrome hiv aids that may have evolved from a known infection e g influenza or spread to a new population e g west nile fever or to an area undergoing ecologic transformation e g lyme disease or be reemerging infections like drug resistant tuberculosis nosocomial hospital acquired infections such as methicillin resistant staphylococcus aureus are emerging in hospitals and extremely problematic in that they are resistant to many antibiotics of growing concern are adverse synergistic interactions between emerging diseases and other infectious and non infectious conditions leading to the development of novel syndemics many emerging diseases are zoonotic an animal reservoir incubates the organism with only occasional transmission into human populations
the emerson effect is the increase in the rate of photosynthesis after chloroplasts are exposed to light of wavelength 670 nm red light and 700 nm far red light when simultaneously exposed to light of both wavelengths the rate of photosynthesis is far higher than the sum of the red light and far red light photosynthesis rates the effect was early evidence that two photosystems processing different wavelengths cooperate in photosynthesis
emery – dreifuss muscular dystrophy is a condition that mainly affects muscles used for movement such as skeletal muscles and also affects the cardiac muscle it is named after alan eglin h emery and fritz e dreifuss
emigration from colombia is a migratory phenomenon that has been taking place in colombia since the early 20 th century
emigration from mexico is a migratory phenomenon that has been taking place in mexico since the early 20 th century
emigration from moldova is a mass phenomenon having a significant impact on the country s demographics and economy
emigration from uruguay is a migratory phenomenon that has been taking place in uruguay since the early 20 th century
emigration from the united states is a complex demographic phenomenon existing for decades and having a number of reasons the process is the reverse of the immigration to the united states for the first centuries of its existence the us benefited from its low population density and had attracted large masses of immigrants and it continues to be a net immigration country the united states does not keep track of emigration and counts of americans abroad are thus only available courtesy of statistics kept by the destination countries
the emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an atom or molecule making a transition from a high energy state to a lower energy state the photon energy of the emitted photon is equal to the energy difference between the two states there are many possible electron transitions for each atom and each transition has a specific energy difference this collection of different transitions leading to different radiated wavelengths make up an emission spectrum each element s emission spectrum is unique therefore spectroscopy can be used to identify the elements in matter of unknown composition similarly the emission spectra of molecules can be used in chemical analysis of substances
“ … a condition exhibiting one or more of the following characteristics over a long period of time and to a marked degree that adversely affects a child ’ s educational performance the classification is often given to students that need individualized behavior supports to receive a free and appropriate public education but would not be eligible for an individualized education program under another disability category of the individuals with disabilities education act idea
emotional conflict is the presence of different and opposing emotions relating to a situation that has recently taken place or is in the process of being unfolded they may be accompanied at times by a physical discomfort especially when a functional disturbance has become associated with an emotional conflict in childhood and in particular by tension headaches expressing a state of inner tension or caused by an unconscious conflict for c g jung emotional conflicts and the intervention of the unconscious are the classical features of medical psychology equally freud s concept of emotional conflict as amplified by anna freud erikson and others is central in contemporary theories of mental disorder in children particularly with respect to the development of psychoneurosis
emotional granularity is an individual s ability to differentiate between the specificity of their emotions an individual with high emotional granularity would be able to discriminate between their emotions that all fall within the same level of valence and arousal labeling their experiences with discrete emotion words someone with low emotional granularity would report their emotions in global terms usually of pleasure or displeasure it is unknown whether these differences of granularity among individuals stem from an inability of some to verbally label the discrete emotions they feel inside or whether some people are simply unaware of the distinctions between specific emotions
emotional self regulation it can also be defined as extrinsic and intrinsic processes responsible for monitoring evaluating and modifying emotional reactions emotion self regulation belongs to the broader set of emotion regulation processes which includes the regulation of one s own feelings and the regulation of other people s feelings emotional regulation is a complex process that involves initiating inhibiting or modulating one s state or behavior in a given situation – for example the subjective experience feelings cognitive responses thoughts emotion related physiological responses for example heart rate or hormonal activity and emotion related behavior bodily actions or expressions functionally emotional regulation can also refer to processes such as the tendency to focus one s attention to a task and the ability to suppress inappropriate behavior under instruction emotional regulation is a highly significant function in human life every day people are continually exposed to a wide variety of potentially arousing stimuli inappropriate extreme or unchecked emotional reactions to such stimuli could impede functional fit within society therefore people must engage in some form of emotion regulation almost all of the time generally speaking emotional dysregulation has been defined as difficulties in controlling the influence of emotional arousal on the organization and quality of thoughts actions and interactions individuals who are emotionally dysregulated exhibit patterns of responding in which there is a mismatch between their goals responses and or modes of expression and the demands of the social environment for example there is a significant association between emotion dysregulation and symptoms of depression anxiety eating pathology and substance abuse higher levels of emotion regulation are likely to be related to both high levels of social competence and the expression of socially appropriate emotions
empathy in chickens is the reaction of a mother hen in response to her observation of adverse conditions imposed upon her chicks the biotechnology and biological research council s animal welfare initiative defines and recognizes that hens possess a fundamental capacity to empathise these empathetic responses in animals are well documented and are usually discussed along with issues related to cognition the difference between animal cognition and animal emotion is recognized by ethicists the specific emotional attribute of empathy in chickens has not been only investigated in terms of its existence but it has applications that have resulted in the designed reduction of stress in farm raised poultry
in medicine emperipolesis is the presence of an intact cell within the cytoplasm of another cell it is derived from greek em is inside peri is around polemai is wander about emperipolesis is an uncommon biological process and can be physiological or pathological it is related to peripolesis which is the attachment of one cell to another emperipolesis is unlike phagocytosis in which the engulfed cell is killed by the lysosomal enzymes of the macrophage instead the engulfed cell remains viable within the other and can exit at any time without causing structural or functional abnormalities in either cell
in telecommunications emphasis is the intentional alteration of the amplitude vs frequency characteristics of the signal to reduce adverse effects of noise in a communication system or recording system typically prior to some process such as transmission over cable or recording to phonograph record or tape the input frequency range most susceptible to noise is boosted this is referred to as pre emphasis pre the process the signal will undergo later when the signal is received or retrieved from recording the reverse transformation is applied de emphasis so that the output accurately reproduces the original input any noise added by transmission or record playback to the frequency range previously boosted is now attenuated in the de emphasis stage the whole system of pre emphasis and de emphasis is called emphasis the high frequency signal components are emphasized to produce a more equal modulation index for the transmitted frequency spectrum and therefore a better signal to noise ratio for the entire frequency range emphasis is commonly used in lp records and fm broadcasting
symptoms of emphysematous cystitis include air in the bladder wall altered mental status severe abdominal pain weakness dark urine dysuria fever lethargy vomiting as well as white blood cells and bacteria in the urine mccabe where some patients may be asymptomatic others may present with septic shock de baets baert symptoms can vary greatly from patient to patient which makes the disease difficult to diagnose in some cases of emphysematous cystitis patients don ’ t even claim to have any urinary symptoms mokabberi urinary symptoms can include blood in the urine increased urinary frequency urgency occasional incontinence difficulty voiding and burning sensation emphysematous cystitis is often indicated in patients who display pneumaturia bobba in some cases emphysematous cystitis can cause thickening of the bladder wall weerakkody clinical subcutaneous emphysema is a rare complication of emphysematous cystitis that has a poor prognosis ahmed ramadan blake
in statistics an empirical distribution function is the distribution function associated with the empirical measure of a sample this cumulative distribution function is a step function that jumps up by 1 n at each of the n data points the empirical distribution function estimates the cumulative distribution function underlying of the points in the sample and converges with probability 1 according to the glivenko – cantelli theorem a number of results exist to quantify the rate of convergence of the empirical distribution function to the underlying cumulative distribution function
empty nose syndrome ens is a rare clinical syndrome in which people who have clear nasal passages experience a range of symptoms most commonly feelings of nasal obstruction nasal dryness and crusting and a sensation of being unable to breathe people who experience ens have usually undergone a turbinectomy removal or reduction of turbinates structures inside the nose or other surgical procedures that interfere with turbinates the overall incidence is unknown but it appears to occur in a small percentage of those who undergo nasosinal procedures it appears to be a health care caused condition but its existence as a medical condition cause diagnosis and management are controversial no one disputes that people with the symptoms suffer a great deal
empty sella syndrome abbreviated ess is where the pituitary gland shrinks or becomes flattened filling the sella turcica or turkish saddle with cerebrospinal fluid on imaging instead of the normal pituitary ess can be found in the radiological workup of pituitary disorders or as an incidental finding when imaging the brain
enamel hypoplasia is a defect of the teeth in which the enamel is hard but thin and deficient in amount caused by defective enamel matrix formation with a deficiency of vitamin d in the body usually the condition involves part of the tooth having a pit in it in some cases the natural enamel crown has a hole in it and in extreme cases the tooth has no enamel which doesn t mean the tooth doesn t exist because dentin is also a component of teeth
an enamel pearl is a condition of teeth where enamel is found on locations where enamel is not supposed to be such as on a root surface they are found usually in the area between roots which is called a furcation of molars enamel pearls are not common in teeth with a single root the most common location of enamel pearl is the furcation areas of the maxillary and mandibular third molar roots the enamel pearls are formed essentially from the hertwig s epithelial root sheath after the initiation of the formation of dentin in the root area of the tooth the root sheath disintegrates and moves away from the root surface so that the cells of the dental sac can come in contact of predentin to differentiate into cementoblasts and start deposition of cementum however if the cells of epithelial root sheath remain adherent to predentin they may differentiate into fully functional ameloblasts and deposit enamel such droplets of enamel are called enamel pearls
enanthem or enanthema is a rash small spots on the mucous membranes it is characteristic of patients with smallpox measles chicken pox and roseola infantum it can also indicate hypersensitivity enanthema can present with viral exanthema
enantiostasis is the ability of an open system especially a living organism to maintain and conserve its metabolic and physiological functions in response to variations in an unstable environment estuarine organisms typically undergo enantiostasis in order to survive with constantly changing salt concentrations the australian nsw board of studies defines the term in its biology syllabus as the maintenance of metabolic and physiological functions in response to variations in the environment enantiostasis is not a form of classical homeostasis meaning standing at a similar level which focused on maintenance of internal body conditions such as ph oxygen levels and ion concentrations rather than maintaining homeostatic stable ideal conditions enantiostasis involves maintaining only functionality in spite of external fluctuations however it can be considered a type of homeostasis in a broader context because functions are kept relatively consistent the term enantiostasis was proposed by mangum and towle it is derived from the greek ἐναντίος enantio opposite opposing over against and στάσις stasis to stand posture an example of an organism which undergoes enantiostasis in an estuary environment includes the oxygen binding effectiveness of hemocyanin in the blue crab callinectes sapidus varies according to the concentration of two factors calcium ion concentration and hydrogen ion concentration when these concentrations are varied in the same direction they have a counterbalancing effect to stabilize oxygen binding at low ionic concentrations the crab increases its internal ph decreasing the hydrogen ion concentration to allow the hemocyanin to continue to function efficiently
encephalitis is a sudden onset inflammation of the brain encephalitis with meningitis is known as meningoencephalitis symptoms include headache fever confusion drowsiness and fatigue further symptoms include seizures or convulsions tremors hallucinations stroke and memory problems in 2013 encephalitis was estimated to have resulted in 77 000 deaths down from 92 000 in 1990 the word is from ancient greek ἐγκέφαλος enképhalos brain composed of ἐν en in and κεφαλή kephalé head and the medical suffix itis inflammation
encephalitis lethargica or von economo disease is an atypical form of encephalitis also known as sleepy sickness distinct from tsetse fly transmitted sleeping sickness it was first described in 1917 by the neurologist constantin von economoand the pathologist jean rené cruchet the disease attacks the brain leaving some victims in a statue like condition speechless and motionless between 1915 and 1926 an epidemic of encephalitis lethargica spread around the world nearly five million people were affected a third of whom died in the acute stages many of those who survived never returned to their pre existing aliveness they would be conscious and aware yet not fully awake they would sit motionless and speechless all day in their chairs totally lacking energy impetus initiative motive appetite affect or desire they registered what went on about them without active attention and with profound indifference they neither conveyed nor felt the feeling of life they were as insubstantial as ghosts and as passive as zombies awakenings oliver sacks p 14 no recurrence of the epidemic has since been reported though isolated cases continue to occur
encephalocele sometimes known as cranium bifidum is a neural tube defect characterized by sac like protrusions of the brain and the membranes that cover it through openings in the skull these defects are caused by failure of the neural tube to close completely during fetal development encephaloceles cause a groove down the middle of the skull or between the forehead and nose or on the back side of the skull the severity of encephalocele varies depending on its location
encephalopathy ɛnˌsɛfəˈlɒpəθi means disorder or disease of the brain in modern usage encephalopathy does not refer to a single disease but rather to a syndrome of overall brain dysfunction this syndrome can have many different organic and inorganic causes
an enchondroma is a cartilage cyst found in the bone marrow typically enchondroma is discovered on an x ray scan enchondromas have a characteristic appearance on magnetic resonance imaging mri as well they have also been reported to cause increased uptake on pet examination
enchondromatosis is a form of osteochondrodysplasia characterized by a proliferation of enchondromas ollier disease can be considered a synonym for enchondromatosis maffucci syndrome is enchondromatosis with hemangiomatosis
encopresis from the ancient greek ἐγκόπρησις egkóprēsis also known as paradoxical diarrhea is voluntary or involuntary fecal soiling in children who have usually already been toilet trained persons with encopresis often leak stool into their undergarments this term is usually applied to children and where the symptom is present in adults it is more commonly known as fecal leakage fl fecal soiling or fecal seepage
in computing end of file commonly abbreviated eof is a condition in a computer operating system where no more data can be read from a data source the data source is usually called a file or stream in general the eof is either determined when the reader returns null as seen in java s bufferedreader or sometimes people will manually insert an eof character of their choosing to signal when the file has ended in the c standard library the character reading functions such as getchar return a value equal to the symbolic value macro eof to indicate that an end of file condition has occurred the actual value of eof is system dependent but is commonly 1 such as in glibc and is unequal to any valid character code block reading functions return the number of bytes read and if this is fewer than asked for then the end of file was reached or an error occurred checking of errno or dedicated function such as ferror is often required to determine which
endaural phenomena are sounds that are heard without any external acoustic stimulation endaural means in the ear phenomena include transient ringing in the ears that sound like sine tones white noise like sounds and subjective tinnitus endaural phenomena need to be distinguished from otoacoustic emissions in which a person s ear emits sounds the emitter typically cannot hear the sounds made by his or her ear endaural phenomena also need to be distinguished from auditory hallucinations which are sometimes associated with psychosis
endemic goitre is a type of goitre that is associated with dietary iodine deficiency some inland areas where soil and water lacks in iodine compounds and consumption of marine foods is low are known for higher incidence of goitre in such areas goitre is said to be endemic this type of goitre is easily preventable in most developed countries regulations have been put into force by health policy institutions requiring salt flour or water to be fortified with iodine treatment of endemic goitre is medical with iodine and thyroxine preparations surgery is only necessary in cases where complicated by significant compression of nearby structures
the enders samp ramp hydrazone alkylation reaction is an asymmetric carbon carbon bond formation reaction facilitated by pyrrolidine chiral auxiliaries it was pioneered by e j corey and d enders in 1976 and was further developed by d enders and his group this method is usually a three step sequence the first step is to form the hydrazone between s 1 amino 2 methoxymethylpyrrolidine samp or r 1 amino 2 methoxymethylpyrrolidine ramp and a ketone or aldehyde afterwards the hydrazone is deprotonated by lithium diisopropylamide lda to form an azaenolate which reacts with alkyl halides or other suitable electrophiles to give alkylated hydrazone species with the simultaneous generation of a new chiral center finally the alkylated ketone or aldehyde can be regenerated by ozonolysis or hydrolysis enders samp ramp hydrazone alkylation reaction this reaction is a useful technique for asymmetric α alkylation of ketones and aldehydes which are common synthetic intermediates for medicinally interesting natural products and other related organic compounds these natural products include c 10 demethyl arteannuin b the structural analog of antimalarial artemisinin the polypropionate metabolite denticulatin a and b isolated from siphonaria denticulata zaragozic acid a a potent inhibitor of sterol synthesis and epothilone a and b which have been proven to be very effective anticancer drugs
ending inventory is the amount of inventory a company has in stock at the end of its fiscal year it is closely related with ending inventory cost which is the amount of money spent to get these goods in stock it should be calculated at the lower of cost or market
endocapillary proliferative glomerulonephritis is a form of glomerulonephritis that can be associated with nephritis it may be associated with parvovirus b 19
endocardial fibroelastosis efe is a rare heart disorder usually occurring in children two years old and younger it may also be considered a reaction to stress not necessarily a specific disease it should not be confused with endomyocardial fibrosis
endocarditis is an inflammation of the inner layer of the heart the endocardium it usually involves the heart valves other structures that may be involved include the interventricular septum the chordae tendineae the mural endocardium or the surfaces of intracardiac devices endocarditis is characterized by lesions known as vegetations which is a mass of platelets fibrin microcolonies of microorganisms and scant inflammatory cells in the subacute form of infective endocarditis the vegetation may also include a center of granulomatous tissue which may fibrose or calcify there are several ways to classify endocarditis the simplest classification is based on cause either infective or non infective depending on whether a microorganism is the source of the inflammation or not regardless the diagnosis of endocarditis is based on clinical features investigations such as an echocardiogram and blood cultures demonstrating the presence of endocarditis causing microorganisms signs and symptoms include fever chills sweating malaise weakness anorexia weight loss splenomegaly flu like feeling cardiac murmur heart failure petechia of anterior trunk janeway s lesions etc
an endocrine bone disease is a bone disease associated with a disorder of the endocrine system an example is osteitis fibrosa cystica
endocrine diseases are disorders of the endocrine system the branch of medicine associated with endocrine disorders is known as endocrinology
an endocrine gland neoplasm is a neoplasm affecting one or more glands of the endocrine system examples include adrenal tumor pituitary adenoma the most common form is thyroid cancer condition such as pancreatic cancer or ovarian cancer can be considered endocrine tumors or classified under other systems pinealoma is often grouped with brain tumors because of its location
endodermal sinus tumor est also known as yolk sac tumor yst is a member of the germ cell tumor group of cancers it is the most common testicular tumor in children under 3 and is also known as infantile embryonal carcinoma this age group has a very good prognosis in contrast to the pure form typical of infants adult endodermal sinus tumors are often found in combination with other kinds of germ cell tumor particularly teratoma and embryonal carcinoma while pure teratoma is usually benign endodermal sinus tumor is malignant
endogenous regeneration in the brain is the ability of cells to engage in the repair and regeneration process while the brain has a limited capacity for regeneration endogenous neural stem cells as well as numerous pro regenerative molecules can participate in replacing and repairing damaged or diseased neurons and glial cells another benefit that can be achieved by using endogenous regeneration could be avoiding an immune response from the host
endolymphatic hydrops is a disorder of the inner ear it consists of an excessive build up of the endolymph fluid which fills the hearing and balance structures of the inner ear endolymph fluid which is partly regulated by the endolymph sac flows through the inner ear and is critical to the function of all sensory cells in the inner ear in addition to water endolymph fluid contains salts such as sodium potassium chloride and other electrolytes if the inner ear is damaged by disease or injury the volume and composition of the endolymph fluid can change causing the symptoms of endolymphatic hydrops
endometrial cancer is a cancer that arises from the endometrium the lining of the uterus or womb it is the result of the abnormal growth of cells that have the ability to invade or spread to other parts of the body the first sign is most often vaginal bleeding not associated with a menstrual period other symptoms include pain with urination or sexual intercourse or pelvic pain endometrial cancer occurs most commonly after menopause approximately 40 of cases are related to obesity endometrial cancer is also associated with excessive estrogen exposure high blood pressure and diabetes whereas taking estrogen alone increases the risk of endometrial cancer taking both estrogen and progesterone in combination as in most birth control pills decreases the risk between two and five percent of cases are related to genes inherited from the parents endometrial cancer is sometimes loosely referred to as uterine cancer although it is distinct from other forms of uterine cancer such as cervical cancer uterine sarcoma and trophoblastic disease the most frequent type of endometrial cancer is endometrioid carcinoma which accounts for more than 80 of cases endometrial cancer is commonly diagnosed by endometrial biopsy or by taking samples during a procedure known as dilation and curettage a pap smear is not typically sufficient to show endometrial cancer regular screening in those at normal risk is not called for the leading treatment option for endometrial cancer is abdominal hysterectomy the total removal by surgery of the uterus together with removal of the fallopian tubes and ovaries on both sides called a bilateral salpingo oophorectomy in more advanced cases radiation therapy chemotherapy or hormone therapy may also be recommended if the disease is diagnosed at an early stage the outcome is favorable and the overall five year survival rate in the united states is greater than 80 in 2012 endometrial cancers occurred in 320 000 women and caused 76 000 deaths this makes it the third most common cause of death in cancers which only affect women behind ovarian and cervical cancer it is more common in the developed world and is the most common cancer of the female reproductive tract in developed countries rates of endometrial cancer have risen in a number of countries between the 1980 s and 2010 this is believed to be due to the increasing number of elderly people and increasing rates of obesity
endometrial hyperplasia is a condition of excessive proliferation of the cells of the endometrium or inner lining of the uterus most cases of endometrial hyperplasia result from high levels of estrogens combined with insufficient levels of the progesterone like hormones which ordinarily counteract estrogen s proliferative effects on this tissue this may occur in a number of settings including obesity polycystic ovary syndrome estrogen producing tumours e g granulosa cell tumour and certain formulations of estrogen replacement therapy endometrial hyperplasia is a significant risk factor for the development or even co existence of endometrial cancer so careful monitoring and treatment of women with this disorder is essential
endometrial intraepithelial neoplasia ein is a premalignant lesion of the uterine lining that predisposes to endometrioid endometrial adenocarcinoma it is composed of a collection of abnormal endometrial cells arising from the glands that line the uterus which have a tendency over time to progress to the most common form of uterine cancer — endometrial adenocarcinoma endometrioid type
an endometrial polyp or uterine polyp is a mass in the inner lining of the uterus they may have a large flat base sessile or be attached to the uterus by an elongated pedicle pedunculated pedunculated polyps are more common than sessile ones they range in size from a few millimeters to several centimeters if pedunculated they can protrude through the cervix into the vagina small blood vessels may be present particularly in large polyps
an endometrial stromal nodule is a noninfiltrative circumscribed proliferation of endometrial stromal cells and is a benign subtype of endometrial stromal tumor the appearance of the cells is identical to normal endometrial stromal cells this can only be differentiated from low grade endometrial stromal sarcoma by confirming lack of infiltration the differential includes cellular leiomyoma diagnosis may be aided by immunostaining endometrial stromal nodules are positive for cd 10 leiomyomas are positive for caldesmon and desmin and sometimes cd 10
endometrial stromal sarcoma is a malignant subtype of endometrial stromal tumor arising from the stroma connective tissue of the endometrium rather than the glands there are three grades for endometrial stromal tumors as follows it was previously known as endolymphatic stromal myosis because of diffuse infiltration of myometrial tissue or the invasion of lymphatic channels
endometrial stromal tumors are a group of stromal tumors of the uterus of low to high grade of malignity
endometrioid tumors are a class of tumor characterized by a resemblance to endometrium endometrial carcinoma and over a third of cases have focal squamous differentiation
endometriosis is a disease in which tissue that normally grows inside the uterus grows outside it the main symptoms are pelvic pain and infertility nearly half of those affected have chronic pelvic pain while in 70 pain occurs during menstruation pain during sex is also common infertility occurs in up to half of women affected less common symptoms include urinary or bowel symptoms about 25 of women have no symptoms endometriosis can have both social and psychological effects the cause is not entirely clear risk factors include having a family history of the condition most often the ovaries fallopian tubes and tissue around the uterus and ovaries are affected however in rare cases it may also occur in other parts of the body the areas of endometriosis bleed each month resulting in inflammation and scarring the growths due to endometriosis are not cancer diagnosis is usually based on symptoms in combination with medical imaging biopsy is the most sure method of diagnosis other causes of similar symptoms include pelvic inflammatory disease irritable bowel syndrome interstitial cystitis and fibromyalgia tentative evidence suggests that the use of combined oral contraceptives reduces the risk of endometriosis exercise and avoiding large amounts of alcohol may also be preventative there is no cure for endometriosis but a number of treatments may improve symptoms this may include pain medication hormonal treatments or surgery the recommended pain medication is usually an nsaid such as naproxen taking the active component of the birth control pill continuously or using an intrauterine device with progestogen may also be useful gonadotropin releasing hormone agonist may improve the ability of those who are infertile to get pregnant surgical removal of endometriosis may be used to treat those whose symptoms are not manageable with other treatments endometriosis is estimated to occur in roughly 6 – 10 of women it is most common in those in their thirties and forties however can begin in girls as early as 8 years old it results in few deaths with this being estimated at 200 globally in 2013 endometriosis was first determined to be a separate condition in the 1920 s before that time endometriosis and adenomyosis were considered together it is unclear who first described the disease
an endometrioma endometrioid cyst endometrial cyst or chocolate cyst of ovary is a condition related to endometriosis
endometritis is inflammation of the endometrium the inner lining of the uterus pathologists have traditionally classified endometritis as either acute or chronic acute endometritis is characterized by the presence of microabscesses or neutrophils within the endometrial glands while chronic endometritis is distinguished by variable numbers of plasma cells within the endometrial stroma the most common cause of endometritis is infection symptoms include lower abdominal pain fever and abnormal vaginal bleeding or discharge caesarean section prolonged rupture of membranes and long labor with multiple vaginal examinations are important risk factors treatment is usually with broad spectrum antibiotics the term endomyometritis is sometimes used to specify inflammation of the endometrium and the myometrium
endometrosis from greek ἔνδον endos inside ancient greek μέτρα metra womb und ancient greek ωσις osis disease is a chronic degenerative disease of the endometrium in domestic species that is clinically and economically important because of limits in fertility endometrosis can be confirmed only by histological examination after endometrial biopsy the disease may occur in female pets of all ages but is more frequently in older age the causes and pathogenesis of endometrosis are widely unknown affected horses tend to miscarriages underdeveloped foal and metritis the changes in the endometrium are widely irreversible an effective treatment is not known there is no relationship between endometrosis and the human disease endometriosis
endophthalmitis is an inflammation of the internal coats of the eye it is a possible complication of all intraocular surgeries particularly cataract surgery with possible loss of vision and the eye itself infectious aetiology is the most common and various bacteria and fungi have been isolated as the cause of the endophthalmitis other causes include penetrating trauma allergic reaction and retained intraocular foreign bodies intravitreal injections expose patients to the risk of endophthalmitis but with an incidence rate usually less than 05
in gynecology endosalpingiosis is a condition in which fallopian tube like epithelium is found outside the fallopian tube it is unknown what causes this condition it is generally accepted that the condition develops from transformation of coelomic tissue it is often an incidental finding and is not usually associated with any pathology
endotheliitis is an immune response within the endothelium in blood vessels in which they become inflamed the condition can cause oedema of the surrounding tissue including the stroma and can cause iritis and pain if it is within the cornea it can result in permanent loss of vision the condition can be caused by a number of factors such as mumps and cytomegalovirus under certain circumstances
an endotype is a subtype of a condition which is defined by a distinct functional or pathobiological mechanism this is distinct from a phenotype which is any observable characteristic or trait of a disease such as morphology development biochemical or physiological properties or behavior without any implication of a mechanism it is envisaged that patients with a specific endotype present themselves within phenotypic clusters of diseases one example is asthma which is considered to be a syndrome consisting of a series of endotypes this is related to the concept of disease entity
endurance also related to sufferance resilience constitution fortitude and hardiness is the ability of an organism to exert itself and remain active for a long period of time as well as its ability to resist withstand recover from and have immunity to trauma wounds or fatigue it is usually used in aerobic or anaerobic exercise the definition of long varies according to the type of exertion – minutes for high intensity anaerobic exercise hours or days for low intensity aerobic exercise training for endurance can have a negative impact on the ability to exert strength unless an individual also undertakes resistance training to counteract this effect when a person is able to accomplish or withstand a higher amount of effort than their original capabilities their endurance is increasing which to many personnel indicates progress in looking to improve ones endurance they may slowly increase the amount of repetitions or time spent if higher repetitions are taken rapidly muscle strength improves while less endurance is gained increasing endurance has been proven to release endorphins resulting in a positive mind the act of gaining endurance through physical activity has been shown to decrease anxiety depression and stress or any chronic disease in total although a greater endurance can assist the cardiovascular system it does not imply that any cardiovascular disease can be guaranteed to improve the major metabolic consequences of the adaptations of muscle to endurance exercise are a slower utilization of muscle glycogen and blood glucose a greater reliance on fat oxidation and less lactate production during exercise of a given intensity the term stamina is sometimes used synonymously and interchangeably with endurance endurance may also refer to an ability to keep going through a tough situation involving hardship stress etc see patience
the ene reaction also known as the alder ene reaction is a chemical reaction between an alkene with an allylic hydrogen the ene and a compound containing a multiple bond the enophile in order to form a new σ bond with migration of the ene double bond and 1 5 hydrogen shift the product is a substituted alkene with the double bond shifted to the allylic position this transformation is a group transfer pericyclic reaction and therefore usually requires highly activated substrates and or high temperatures nonetheless the reaction is compatible with a wide variety of functional groups that can be appended to the ene and enophile moieties also many useful lewis acid catalyzed ene reactions have been developed which can afford high yields and selectivities at significantly lower temperatures making the ene reaction a useful c – c forming tool for the synthesis of complex molecules and natural products
in relativistic classical field theories of gravitation particularly general relativity an energy condition is one of various alternative conditions which can be applied to the matter content of the theory when it is either not possible or desirable to specify this content explicitly the hope is then that any reasonable matter theory will satisfy this condition or at least will preserve the condition if it is satisfied by the starting conditions in general relativity energy conditions are often used and required in proofs of various important theorems about black holes such as the no hair theorem or the laws of black hole thermodynamics
energy density is the amount of energy stored in a given system or region of space per unit volume or mass though the latter is more accurately termed specific energy often only the useful or extractable energy is measured which is to say that chemically inaccessible energy such as rest mass energy is ignored in cosmological and other general relativistic contexts however the energy densities considered are those that correspond to the elements of the stress – energy tensor and therefore do include mass energy as well as energy densities associated with the pressures described in the next paragraph energy per unit volume has the same physical units as pressure and in many circumstances is a synonym for example the energy density of a magnetic field may be expressed as and behaves as a physical pressure and the energy required to compress a compressed gas a little more may be determined by multiplying the difference between the gas pressure and the external pressure by the change in volume in short pressure is a measure of the enthalpy per unit volume of a system a pressure gradient has a potential to perform work on the surroundings by converting enthalpy until equilibrium is reached
energy in zimbabwe is a serious problem for the country mainly extensive use of firewood leads to deforestation and the electricity production capacity is too low for the current level of consumption
energy poverty is lack of access to modern energy services it refers to the situation of large numbers of people in developing countries whose well being is negatively affected by very low consumption of energy use of dirty or polluting fuels and excessive time spent collecting fuel to meet basic needs it is inversely related to access to modern energy services although improving access is only one factor in efforts to reduce energy poverty energy poverty is distinct from fuel poverty which focuses solely on the issue of affordability according to the energy poverty action initiative of the world economic forum access to energy is fundamental to improving quality of life and is a key imperative for economic development in the developing world energy poverty is still rife nearly 1 6 billion people still have no access to electricity according to the international energy agency iea as a result of this situation a new un initiative has been launched to coincide with the designation of 2012 as the international year for sustainable energy for all which has a major focus on reducing energy poverty duke university has launched a research project on household energy and health where work on energy poverty in india is listed
energy rate density is the amount of energy per unit time per unit mass in cgs metric units erg s g in mks units joule s kg it is terminologically but not always numerically equivalent to power density when measured in si units of w kg regardless of the units used energy rate density describes the flow of energy through any system of given mass and has been proposed as a measure of system complexity energy rate density is actually a general term that is equivalent to more specialized terms used by many different disciplinary scientists for example in astronomy it is called the luminosity to mass ratio the inverse of the mass luminosity ratio in physics the power density in geology the specific radiant flux where “ specific ” denotes per unit mass in biology the specific metabolic rate and in engineering the power to weight ratio interdisciplinary researchers prefer to use the general term energy rate density not only to stress the intuitive notion of energy flow in contrast to more colloquial connotations of the word power but also to unify its potential application among all the natural sciences as in the cosmology of cosmic evolution this term has in recent years gained many diverse applications in various disciplines including history cosmology economics philosophy and behavioral biology
the energy value of coal or the fuel content is the amount of potential energy in coal that can be converted into actual heating ability the value can be calculated and compared with different grades of coal or even other materials materials of different grades will produce differing amounts of heat for a given mass while chemistry provides methods of calculating the heating value of a certain amount of a substance there is a difference between this theoretical value and its application to real coal the grade of a sample of coal does not precisely define its chemical composition so calculating the actual usefulness of coal as a fuel requires determining its proximate and ultimate analysis see chemical composition below
in conventional classical music theory the english cadence is a distinctive contrapuntal pattern particular to the authentic or perfect cadence described as archaic or old fashioned sounding this pattern is so named because of its use primarily by english composers of the high renaissance and restoration periods the hallmark of this device is the dissonant augmented octave compound augmented unison produced by a false relation between the split seventh scale degree popular with english composers in the sixteenth and seventeenth centuries but named in the twentieth century the english cadence is a type of full close featuring the blue seventh against the dominant chord which in c would be b ♭ and g – b ♮ – d
large vestibular aqueduct also known as enlarged vestibular aqueduct syndrome is a syndromic form of hearing loss caused by enlargement of the vestibular aqueduct in the inner ear it is one of the most common inner ear deformities which results in hearing loss during childhood
enolase deficiency is a rare genetic disorder of glucose metabolism partial deficiencies have been observed in several caucasian families the deficiency is transmitted through an autosomal dominant inheritance pattern the gene for enolase 1 has been localized to chromosome 1 in humans enolase deficiency like other glycolytic enzyme deficiences usually manifests in red blood cells as they rely entirely on anaerobic glycolysis enolase deficiency is associated with a spherocytic phenotype and can result in hemolytic anemia which is responsible for the clinical signs of enolase deficiency
enophthalmos is the posterior displacement of the eyeball within the orbit due to changes in the volume of the orbit bone relative to its contents the eyeball and orbital fat or loss of function of the orbitalis muscle it should not be confused with its opposite exophthalmos which is the anterior displacement of the eye it may be a congenital anomaly or be acquired as a result of trauma such as in a blowout fracture of the orbit horner s syndrome apparent enophthalmos due to ptosis marfan syndrome duane s syndrome silent sinus syndrome or phthisis bulbi
in statistical mechanics the ensemble average is defined as the mean of a quantity that is a function of the microstate of a system the ensemble of possible states according to the distribution of the system on its micro states in this ensemble since the ensemble average is dependent on the ensemble chosen its mathematical expression varies from ensemble to ensemble however the mean obtained for a given physical quantity doesn t depend on the ensemble chosen at the thermodynamic limit grand canonical ensemble is an example of open system
enteric duplication cysts sometimes simply called duplication cysts are rare congenital malformations of the gastrointestinal tract they most frequently occur in the small intestine particularly the ileum but can occur anywhere along the gastrointestinal tract they may be cystic or tubular in conformation the condition of having duplication cysts has been called intestinal duplication
enteric neuropathy is a degenerative neuromuscular condition of the digestive system in simple terms the gut stops functioning due to degradation of the nerves and muscles the condition affects all parts of the digestive tract there is no known cure or treatment for enteric neuropathy at this time it is only possible to work on symptom management the name enteric neuropathy only seems to be used for diagnosis within the uk the most common name worldwide for this condition is intestinal pseudoobstruction
enteric redmouth disease or simply redmouth disease is a bacterial infection of freshwater and marine fish caused by the pathogen yersinia ruckeri it is primarily found in rainbow trout oncorhynchus mykiss and other cultured salmonids the disease is characterized by subcutaneous hemorrhaging of the mouth fins and eyes it is most commonly seen in fish farms with poor water quality redmouth disease was first discovered in idaho rainbow trout in the 1950 s the disease does not infect humans
enteritis is inflammation of the small intestine it is most commonly caused by food or drink contaminated with pathogenic microbes but may have other causes such as nsaids cocaine radiation therapy as well as autoimmune conditions like crohn s disease and coeliac disease symptoms include abdominal pain cramping diarrhoea dehydration and fever related diseases include inflammation of the stomach gastritis and large intestine colitis duodenitis jejunitis and ileitis are subtypes of enteritis which are only localised to a specific part of the small intestine inflammation of both the stomach and small intestine is referred to as gastroenteritis inflammation of related organs of the gastrointestinal system are gastritisstomach gastroenteritisstomach and small intestine colitislarge intestine enterocolitislarge and small intestine
an enterocele or enterocoele is a protrusion of the small intestines and peritoneum into the vaginal canal it may be treated transvaginally or by laparoscopy an enterocele may also obstruct the rectum leading to symptoms of obstructed defecation
enterocolitis or coloenteritis is an inflammation of the digestive tract involving enteritis of the small intestine and colitis of the colon it may be caused by various infections with bacteria viruses fungi parasites or other causes common clinical manifestations of enterocolitis are frequent diarrheal defecations with or without nausea vomiting abdominal pain fever chills alteration of general condition general manifestations are given by the dissemination of the infectious agent or its toxins throughout the body or – most frequently – by significant losses of water and minerals the consequence of diarrhea and vomiting among the etiologic agents of acute enterocolitis are bacteria salmonella shigella escherichia coli campylobacter etc viruses enteroviruses rotaviruses norwalk virus adenoviruses fungi candidiasis especially in immunosuppressed patients or who have previously received prolonged antibiotic treatment parasites giardia lamblia with high frequency of infestation in the population but not always with clinical manifestations balantidium coli blastocystis homnis cryptosporidium diarrhea in people with immunosuppression entamoeba histolytica produces the amebian dysentery common in tropical areas
enteroenteric circulation is the secretion back into the intestines of substances previously taken up from it it occurs when there is a negative relative concentration of substance in theintestines making it passively diffuse from the mesenteric circulation into the intestinal lumen and is trapped examples of toxins that exhibit enteroenteric circulation include theophylline phenobarbital and phenytoin administration of activated charcoal inhibits the enteroenteric circulation of such substances and is therefore useful in overdose or intoxication
enteroinvasive escherichia coli eiec is a type of pathogenic bacteria whose infection causes a syndrome that is identical to shigellosis with profuse diarrhea and high fever eiec are highly invasive and they use adhesin proteins to bind to and enter intestinal cells they produce no toxins but severely damage the intestinal wall through mechanical cell destruction it is closely related to shigella after the e coli strain penetrates through the epithelial wall the endocytosis vacuole gets lysed the strain multiplies using the host cell machinery and extends to the adjacent epithelial cell in addition the plasmid of the strain carries genes for a type iii secretion system that is used as the virulent factor although it is an invasive disease the invasion usually does not pass the submucosal layer the similar pathology to shigellosis may be because both strains of bacteria share some virulent factors the invasion of the cells can trigger a mild form of diarrhea or dysentery often mistaken for dysentery caused by shigella species the illness is characterized by the appearance of blood and mucus in the stools of infected individuals or a condition called colitis dysentery caused by eiec usually occurs within 12 to 72 hours following the ingestion of contaminated food the illness is characterized by abdominal cramps diarrhea vomiting fever chills and a generalized malaise dysentery caused by this organism is generally self limiting with no known complications enterovirulent classes of e coli are referred to as the eec group enterovirulent e coli 1 enteroinvasive e coli eiec invades passes into the intestinal wall to produce severe diarrhea 2 enterohemorrhagic e coli ehec a type of ehec e coli 0157 h 7 can cause bloody diarrhea and hemolytic uremic syndrome anemia and kidney failure 3 enterotoxigenic e coli etec produces a toxin that acts on the intestinal lining and is the most common cause of traveler s diarrhea 4 enteropathogenic e coli epec can cause diarrhea outbreaks in newborn nurseries 5 enteroaggregative e coli eaggec can cause acute and chronic long lasting diarrhea in children it is currently unknown what foods may harbor eiec but any food contaminated with human feces from an ill individual either directly or via contaminated water could cause disease in others outbreaks have been associated with hamburger meat and unpasteurized milk
an enterolith is a mineral concretion or calculus formed anywhere in the gastrointestinal system enteroliths are uncommon and usually incidental findings but once found they require at a minimum watchful waiting if there is evidence of complications they must be removed an enterolith may form around a nidus a small foreign object such as a seed pebble or piece of twine that serves as an irritant in this respect an enterolith forms by a process similar to the creation of a pearl an enterolith is not to be confused with a gastrolith which helps digestion
enteropathy refers to any pathology of the intestine although enteritis specifically refers to an inflammation of the intestine and is thus a more specific term than enteropathy the two phrases are sometimes used interchangeably
enteropathy associated t cell lymphoma eatl also enteropathy type t cell lymphoma ettl is a type of t cell lymphoma that affects the small intestine it is the most common primary gastrointestinal t cell lymphoma arising from the t cells that are found between the cells that line the small intestinal brush border cells or small intestinal epithelial cells these cancerous t cells are a possible consequence of refractory cases of coeliac disease or in chronic untreated cases in genetically susceptible individuals
enterotoxemia is an infection by clostridium perfringens which affects several types of domesticated animals but is not known to affect humans it is also known as overeating disease and can kill the animals within two hours the disease is far more frequent in sheep than in any other animal species it caused enormous economical losses before vaccination programs were implemented it is sometimes known as pulpy kidney enlarged gall bladder sheep inflamed intestinal lymph nodes sheep
enterotoxigenic escherichia coli etec is a type of escherichia coli and one of the leading bacterial causes of diarrhea in the developing world as well as the most common cause of travelers diarrhea insufficient data exist but conservative estimates suggest that each year about 157 000 deaths occur mostly in children from etec a number of pathogenic isolates are termed etec but the main hallmarks of this type of bacteria are expression of one or more enterotoxins and presence of fimbriae used for attachment to host intestinal cells
enterprise information integration eii is the ability to support a unified view of data and information for an entire organization in a data virtualization application of eii a process of information integration using data abstraction to provide a unified interface known as uniform data access for viewing all the data within an organization and a single set of structures and naming conventions known as uniform information representation to represent this data the goal of eii is to get a large set of heterogeneous data sources to appear to a user or system as a single homogeneous data source
enterprise interoperability is the ability of an enterprise — a company or other large organization — to functionally link activities such as product design supply chains manufacturing in an efficient and competitive way the research in interoperability of enterprise practised in is various domains itself enterprise modelling ontologies information systems architectures and platforms which it is a question of positioning
in the domain of the service orientation design paradigm the enterprise inventory is a design pattern by thomas erl that answers the question how can services be delivered to maximize recomposition the application of this pattern results in a standardized enterprise wide service inventory that fosters repeated service composition
enthesitis is inflammation of the entheses the sites where tendons or ligaments insert into the bone it is also called enthesopathy or any pathologic condition involving the entheses the entheses are any point of attachment of skeletal muscles to the bone where recurring stress or inflammatory autoimmune disease can cause inflammation or occasionally fibrosis and calcification one of the primary entheses involved in inflammatory autoimmune disease is at the heel particularly the achilles tendon it is associated with hla b 27 arthropathies like ankylosing spondylitis psoriatic arthritis and reactive arthritis symptoms include multiple points of tenderness at the heel tibial tuberosity iliac crest and other tendon insertion sites
in medicine an enthesopathy refers to a disorder involving the attachment of a tendon or ligament to a bone this site of attachment is known as the entheses if the condition is known to be inflammatory it can more precisely be called an enthesitis
in complex analysis an entire function also called an integral function is a complex valued function that is holomorphic over the whole complex plane typical examples of entire functions are polynomials and the exponential function and any sums products and compositions of these such as the trigonometric functions sine and cosine and their hyperbolic counterparts sinh and cosh as well as derivatives and integrals of entire functions such as the error function if an entire function f z has a root at w then f z z − w is an entire function on the other hand neither the natural logarithm nor the square root is an entire function nor can they be continued analytically to an entire function a transcendental entire function is an entire function that is not a polynomial
entity abstraction is a design pattern applied within the service orientation design paradigm which provides guidelines for designing reusable services whose functional contexts are based on business entities
entity component system ecs is an architectural pattern that is mostly used in game development an ecs follows the composition over inheritance principle that allows greater flexibility in defining entities where every object in a game s scene is an entity e g enemies bullets vehicles etc every entity consists of one or more components which add additional behavior or functionality therefore the behavior of an entity can be changed at runtime by adding or removing components this eliminates the ambiguity problems of deep and wide inheritance hierarchies that are difficult to understand maintain and extend common ecs approaches are highly compatible and often combined with data oriented design techniques
entomophthoramycosis or entomophthoromycosis is a mycosis caused by entomophthorales examples include basidiobolomycosis and conidiobolomycosis
detrainment is the opposite effect when the air from a convective cloud usually at its top is injected in the environment
entropia is pain of salvation s first studio album it is a concept album concerning the story of a family in a fictional society that is torn apart by a war the title is a portmanteau of entropy from thermodynamics the measure of disorder present in a system and utopia the ideal society this is the only album to feature daniel magdic on guitar
entropion is a medical condition in which the eyelid usually the lower lid folds inward it is very uncomfortable as the eyelashes constantly rub against the cornea and irritate it entropion is usually caused by genetic factors this is different from when an extra fold of skin on the lower eyelid causes lashes to turn in towards the eye epiblepharon in epiblepharons the eyelid margin itself is in the correct position but the extra fold of skin causes the lashes to be misdirected entropion can also create secondary pain of the eye leading to self trauma scarring of the eyelid or nerve damage the upper or lower eyelid can be involved and one or both eyes may be affected when entropion occurs in both eyes this is known as bilateral entropion repeated cases of trachoma infection may cause scarring of the inner eyelid which may cause entropion in human cases this condition is most common to people over 60 years of age
in thermodynamics the entropy of mixing is the increase in the total entropy when several initially separate systems of different composition each in a thermodynamic state of internal equilibrium are mixed without chemical reaction by the thermodynamic operation of removal of impermeable partition s between them followed by a time for establishment of a new thermodynamic state of internal equilibrium in the new unpartitioned closed system in general the mixing may be constrained to occur under various prescribed conditions in the customarily prescribed conditions the materials are each initially at a common temperature and pressure and the new system may change its volume while being maintained at that same constant temperature pressure and chemical component masses the volume available for each material to explore is increased from that of its initially separate compartment to the total common final volume the final volume need not be the sum of the initially separate volumes so that work can be done on or by the new closed system during the process of mixing as well as heat being transferred to or from the surroundings because of the maintenance of constant pressure and temperature the internal energy of the new closed system is equal to the sum of the internal energies of the initially separate systems the reference values for the internal energies should be specified in a way that is constrained to make this so maintaining also that the internal energies are respectively proportional to the masses of the systems for concision in this article the term ideal material is used to refer to an ideal gas mixture or an ideal solution in a process of mixing of ideal materials the final common volume is the sum of the initial separate compartment volumes there is no heat transfer and no work is done the entropy of mixing is entirely accounted for by the diffusive expansion of each material into a final volume not initially accessible to it on the mixing of non ideal materials the total final common volume may be different from the sum of the separate initial volumes and there may occur transfer of work or heat to or from the surroundings also there may be a departure of the entropy of mixing from that of the corresponding ideal case that departure is the main reason for interest in entropy of mixing these energy and entropy variables and their temperature dependences provide valuable information about the properties of the materials on a molecular level the entropy of mixing is of interest because it is a macroscopic variable that provides information about constitutive molecular properties in ideal materials intermolecular forces are the same between every pair of molecular kinds so that a molecule feels no difference between other molecules of its own kind and of those of the other kind in non ideal materials there may be differences of intermolecular forces or specific molecular effects between different species even though they are chemically non reacting the entropy of mixing provides information about constitutive differences of intermolecular forces or specific molecular effects in the materials the statistical concept of randomness is used for statistical mechanical explanation of the entropy of mixing mixing of ideal materials is regarded as random at a molecular level and correspondingly mixing of non ideal materials may be non random
enuresis from the ancient greek ἐνούρησις enoúrēsis is a repeated inability to control urination use of the term is usually limited to describing individuals old enough to be expected to exercise such control involuntary urination is also known as urinary incontinence
environmental degradation is the deterioration of the environment through depletion of resources such as air water and soil the destruction of ecosystems and the extinction of wildlife it is defined as any change or disturbance to the environment perceived to be deleterious or undesirable as indicated by the i pat equation environmental impact i or degradation is caused by the combination of an already very large and increasing human population p continually increasing economic growth or per capita affluence a and the application of resource depleting and polluting technology t environmental degradation is one of the ten threats officially cautioned by the high level panel on threats challenges and change of the united nations the united nations international strategy for disaster reduction defines environmental degradation as the reduction of the capacity of the environment to meet social and ecological objectives and needs environmental degradation is of many types when natural habitats are destroyed or natural resources are depleted the environment is degraded efforts to counteract this problem include environmental protection and environmental resources management
environmental dependency syndrome is a syndrome where the affected individual relies on environmental cues in order to accomplish goals or tasks it is a disorder in personal autonomy that is influenced by individual psychological traits and can be helped through the intervention of other people for example adults diagnosed with attention deficit hyperactivity disorder have relied on special coaches to provide cues at appropriate times helping them to make decisions about how to prioritize and order tasks
in epidemiology environmental diseases are diseases that can be directly attributed to environmental factors as distinct from genetic factors or infection apart from the true monogenic genetic disorders environmental diseases may determine the development of disease in those genetically predisposed to a particular condition stress physical and mental abuse diet exposure to toxins pathogens radiation and chemicals found in almost all personal care products and household cleaners are possible causes of a large segment of non hereditary disease if a disease process is concluded to be the result of a combination of genetic and environmental factor influences its etiological origin can be referred to as having a multifactorial pattern there are many different types of environmental disease including lifestyle disease such as cardiovascular disease diseases caused by substance abuse such as alcoholism and smoking related disease disease caused by physical factors in the environment such as skin cancer caused by excessive exposure to ultraviolet radiation in sunlight disease caused by exposure to toxic or irritant chemicals in the environment such as toxic metals
environmental enteropathy also known as tropical enteropathy or environmental enteric dysfunction eed is a condition or subclinical disorder believed to be due to frequent intestinal infections there are often minimal acute symptoms there may be chronic problems with absorbing nutrients which may result in malnutrition and growth stunting in children it may be the chronic form of tropical sprue which is usually brief and presents with diarrhea environmental enteropathy results in a number of changes in the intestines including smaller villi larger crypts called crypt hyperplasia increased permeability and inflammatory cell build up within the intestines these changes result in poor absorption of food vitamins and minerals – or modest malabsorption
an environmental error is an error in calculations that are being a part of observations due to environment any experiment performing anywhere in the universe has its surroundings from which we cannot eliminate our system the study of environmental effects has primary advantage of being able us to justify the fact that environment has impact on experiments and feasible environment will not only rectify our result but also amplify it
environmental factor or ecological factor or ecofactor is any factor abiotic or biotic that influences living organisms abiotic factors include ambient temperature amount of sunlight and ph of the water soil in which an organism lives biotic factors would include the availability of food organisms and the presence of conspecifics competitors predators and parasites
the concept of environmental space is the amount of any particularresource that can be consumed by a country without threatening the continuedavailability of that resource assuming that everyone in the world isentitled to an equal share the weakness of the concept is that it requirescalculating the maximum sustainable consumption rate of each differentresource globally this rate could be set by either the maximum sustainableyield say for forests or fisheries or the assimilative capacity of theenvironment e g for co 2 or chlorine but both quantities are very difficult to determine so the environmental space has rather large error limits and is therefore hard to defend in policy discussions a further difficulty isthat there is a different environmental space for each kind of resource and as they each necessarily have different units of measure they cannot beadded to get an overall environmental space for all the resources consumed by a country theidea of environmental space was promoted quite strongly by friends of the earth europe in themid 1990 s but it is rarely used now because of the aforementioned difficulties and has essentially been superseded by ecological footprint the advantage of the ecological footprint is that every kind of resource use is converted to a land area basis so that they can be added to produce an overall figure fora country allowing comparisons to be made
an enyne metathesis is an organic reaction taking place between an alkyne and an alkene with a metal carbene catalyst forming a butadiene this reaction is a variation of olefin metathesis the general scheme is given by scheme 1 scheme 1 enyne metathesis when the reaction is intramolecular in an enyne it is called ring closing enyne metathesis or rceym scheme 2 scheme 2 ring closing enyne metathesis with y representing oxygen or nitrogen and n an integer the reaction was first described in 1985 with the conversion of biphenyl 3 1 to a phenanthrene in scheme 3 scheme 3 enyne metathesis 1985 the carbene is a tungsten carbonyl when used in stoichiometric amounts 1 equivalent yields 41 of the phenanthrene 3 2 and when used in catalytic amounts phenanthrene 3 3 the stereoselectivity of this reaction is large with the metal atom exclusively adding to one of the alkyne carbon atoms in the initial reaction step
enzymatic interesterification eie is the catalytic reaction that occurs when an enzyme is introduced into oil and rearranges the fatty acids on the glycerol backbone of a triglyceride triglycerides are either liquid or solid at room temperature the rearrangement of the fatty acids that occurs with enzymatic interesterification provides structure and functionality to triglycerides at room temperature this process adjusts the melting properties increasing functionality and plasticity in food production applications one of five different ways of altering melting property profiles enzymatic interesterification is unlike the more widely used partial hydrogenation method in that it produces no trans fatty acids and lowers saturated fat content
enzyme catalysis is the increase in the rate of a chemical reaction by the active site of a protein the protein catalyst enzyme may be part of a multi subunit complex and or may transiently or permanently associate with a cofactor e g adenosine triphosphate catalysis of biochemical reactions in the cell is vital due to the very low reaction rates of the uncatalysed reactions at room temperature and pressure a key driver of protein evolution is the optimization of such catalytic activities via protein dynamics the mechanism of enzyme catalysis is similar in principle to other types of chemical catalysis by providing an alternative reaction route the enzyme reduces the energy required to reach the highest energy transition state of the reaction the reduction of activation energy ea increases the amount of reactant molecules that achieve a sufficient level of energy such that they reach the activation energy and form the product as with other catalysts the enzyme is not consumed during the reaction as a substrate is but is recycled such that a single enzyme performs many rounds of catalysis
enzyme promiscuity is the ability of an enzyme to catalyse a fortuitous side reaction in addition to its main reaction although enzymes are remarkably specific catalysts they can often perform side reactions in addition to their main native catalytic activity these promiscuous activities are usually slow relative to the main activity and are under neutral selection despite ordinarily being physiologically irrelevant under new selective pressures these activities may confer a fitness benefit therefore prompting the evolution of the formerly promiscuous activity to become the new main activity an example of this is the atrazine chlorohydrolase atza encoded from pseudomonas sp adp which evolved from melamine deaminase tria encoded which has very small promiscuous activity towards atrazine a man made chemical
an eolith from greek eos dawn and lithos stone is a chipped flint nodule eoliths were once thought to have been artifacts the earliest stone tools but are now believed to be naturally produced by geological processes such as glaciation the first eoliths were collected in kent by benjamin harrison an amateur naturalist and archaeologist in 1885 though the name eolith wasn t coined until 1892 by j allen browne harrison s discoveries were published by sir joseph prestwich in 1891 and eoliths were generally accepted to have been crudely made tools dating from the pliocene further discoveries of eoliths in the early 20 th century – in east anglia by j reid moir and in continental europe by aimé louis rutot and h klaatsch – were taken to be evidence of human habitation of those areas before the oldest known fossils indeed the english finds helped to secure acceptance of the hoax remains of piltdown man because eoliths were so crude concern began to be raised that they were indistinguishable from the natural processes of erosion marcellin boule a french archaeologist published an argument against the artifactual status of eoliths in 1905 and samuel hazzledine warren provided confirmation of boule s view after carrying out experiments on flints although the debate continued for about three decades more and more evidence was discovered that suggested a purely natural origin for eoliths this together with the discovery of genuine early lower pleistocene oldowan tools in east africa made support for the artifact theory difficult to sustain
eosinopenia is a form of agranulocytosis where the number of eosinophil granulocytes is lower than expected leukocytosis with eosinopenia can be a predictor of bacterial infection it can be induced by stress reactions cushing s syndrome or the use of steroids pathological causes include burns and acute infections
eosinophilia is a condition in which the eosinophil count in the peripheral blood exceeds 4 5 × 108 l 450 µl eosinophils usually account for less than 7 of the circulating leukocytes a marked increase in non blood tissue eosinophil count noticed upon histopathologic examination is diagnostic for tissue eosinophilia several causes are known with the most common being some form of allergic reaction or parasitic infection diagnosis of eosinophilia is via a complete blood count cbc but diagnostic procedures directed at the underlying cause vary depending on the suspected condition s an absolute eosinophil count is not generally needed if the cbc shows marked eosinophilia the location of the causal factor can be used to classify eosinophilia into two general types extrinsic in which the factor lies outside of the eosinophil cell lineage and intrinsic eosinophilia which denotes etiologies within the eosiniphil cell line specific treatments are dictated by the causative condition though in idiopathic eosinophilia the disease may be controlled with corticosteroids eosinophilia is not a disorder rather only a sign unless it is idiopathic
eosinophilia – myalgia syndrome ems is an incurable and sometimes fatal flu like neurological condition linked to the ingestion of the dietary supplement l tryptophan the risk of developing ems increases with larger doses of tryptophan and increasing age some research suggests that certain genetic polymorphisms may be related to the development of ems the presence of eosinophilia is a core feature of ems along with unusually severe myalgia muscle pain
eosinophilic bronchitis is a type of airway inflammation due to excessive mast cell recruitment and activation in the superficial airways as opposed to the smooth muscles of the airways as seen in asthma it often results in a chronic cough lung function tests are usually normal inhaled corticosteroids are often an effective treatment
eosinophilic cellulitis also known as wells syndrome from george crichton wells who first described it is a skin condition characterized by plaques that resemble cellulitis eosinophilic cellulitis is of unknown etiology though it is suspected to have an allergic and or autoimmune component there are documented cases of it being caused by flea and other insect bites and it has been seen in conjunction with churg strauss disease though many cases are considered idiopathic in addition it has also been reported in a case of igg 4 related disease it is included in the raredisease org database typical treatment is with prednisone
eosinophilic cystitis is a rare condition where eosinophiles are present in the bladder wall signs and symptoms are similar to a bladder infection its cause is not entirely clear however may be linked to food allergies infections and medications among others
eosinophilic esophagitis eosinophilic oesophagitis also known as allergic oesophagitis is an allergic inflammatory condition of the esophagus that involves eosinophils a type of white blood cell symptoms are swallowing difficulty food impaction and heartburn eosinophilic esophagitis eoe was first described in children but also occurs in adults the condition is not well understood but food allergy may play a significant role the treatment may consist of removal of known or suspected triggers and medication to suppress the immune response in severe cases it may be necessary to stretch the esophagus with an endoscopy procedure
eosinophilic fasciitis ˌiːəˌsɪnəˈfɪlɪk ˌfæʃiˈaɪtᵻs ˌiːoʊ ˌfæsi also known as shulman s syndrome is a form of fasciitis the inflammatory diseases that affect the fascia the connective tissues surrounding muscles blood vessels and nerves unlike other diseases in that category it is limited to the arms and legs and usually resolves itself although some cases require corticosteroids and some cases are associated with aplastic anemia the presentation of eosinophilic fasciitis is similar to scleroderma or systemic sclerosis however unlike scleroderma it affects the fascia not the skin dermis the characteristic and severe effects of scleroderma and systemic sclerosis such as raynaud s syndrome involvement of the extremities prominent small blood vessels telangiectasia and visceral changes such as swallowing problems are absent it was first characterized in 1974 and it is not yet known whether it is actually a distinct condition or just a different presentation however it remains used for diagnostic purposes several cases have been reported after strenuous exercise
eosinophilic folliculitis also known as eosinophilic pustular folliculitis and sterile eosinophilic pustulosis is an itchy rash with an unknown cause that is most common among individuals with hiv though it can occur in hiv negative individuals where it is known by the eponym ofuji disease ef consists of itchy red bumps papules centered on hair follicles and typically found on the upper body sparing the abdomen and legs the name eosinophilic folliculitis refers to the predominant immune cells associated with the disease eosinophils and the involvement of the hair follicles
eosinophilic gastroenteritis eg is a rare and heterogeneous condition characterized by patchy or diffuse eosinophilic infiltration of gastrointestinal gi tissue first described by kaijser in 1937 presentation may vary depending on location as well as depth and extent of bowel wall involvement and usually runs a chronic relapsing course it can be classified into mucosal muscular and serosal types based on the depth of involvement any part of the gi tract can be affected and isolated biliary tract involvement has also been reported the stomach is the organ most commonly affected followed by the small intestine and the colon
eosinophilic granulomatosis with polyangiitis egpa also known as churg strauss syndrome css or allergic granulomatosis is a rare autoimmune condition that causes inflammation of small and medium sized blood vessels vasculitis in persons with a history of airway allergic hypersensitivity atopy it usually manifests in three stages the early prodromal stage is marked by airway inflammation almost all patients experience asthma and or allergic rhinitis the second stage is characterized by abnormally high numbers of eosinophils hypereosinophilia which causes tissue damage most commonly to the lungs and the digestive tract the third stage consists of vasculitis which can eventually lead to cell death and can be life threatening this condition is now called eosinophilic granulomatosis with polyangiitis to remove all eponyms from the vasculitides to facilitate the transition it was referred to as eosinophilic granulomatosis with polyangiitis churg strauss for a period of time starting in 2012 prior to this it was known as churg strauss syndrome named after drs jacob churg and lotte strauss who in 1951 first published about the syndrome using the term allergic granulomatosis to describe it it is a type of systemic necrotizing vasculitis effective treatment of egpa requires suppression of the immune system with medication this is typically glucocorticoids followed by other agents such as cyclophosphamide or azathioprine
eosinophilic pneumonia ep is a disease in which an eosinophil a type of white blood cell accumulates in the lung these cells cause disruption of the normal air spaces alveoli where oxygen is extracted from the atmosphere several different kinds of eosinophilic pneumonia exist and can occur in any age group the most common symptoms include cough fever difficulty breathing and sweating at night ep is diagnosed by a combination of characteristic symptoms findings on a physical examination by a health provider and the results of blood tests and x rays prognosis is excellent once most ep is recognized and treatment with corticosteroids is begun
eosinophilic pustular folliculitis of infancy also known as eosinophilic pustular folliculitis in infancy infantile eosinophilic pustular folliculitis and neonatal eosinophilic pustular folliculitis is a cutaneous condition characterized by recurrent pruritic crops of follicular vesiculopustular lesions
eosinophilic ulcer of the oral mucosa also known as eosinophilic ulcer of the tongue riga – fede disease and traumatic eosinophilic granuloma is a condition characterized by an ulcer with an indurated and elevated border the lesion might be tender fast growing and the patient often not be aware of any trauma in the area
eosinophilic vasculitis is a cutaneous condition characterized by an inflammation of blood vessels and the presence of eosinophils
eosinophiluria is the abnormal presence of eosinophils in the urine it can be measured by detecting levels of eosinophil cationic protein
eparchaean unconformity is located in andhra pradesheparchaean unconformityeparchaean unconformityeparchaean unconformity is located in indiaeparchaean unconformityeparchaean unconformity eparchaean unconformity tirupati hills is a major discontinuity of stratigraphic significance that represents a period of remarkable serenity in the geological history of the earth it is seen at the steep natural slopes road scars and ravines in the tirupati – tirumala ghat road in chittoor district of andhra pradesh india in 2001 the geological survey of india gsi declared the unconformity to be one of the 26 “ geological monuments of india ” gsi s commemoration document published on the occasion of the 150 years anniversary celebration provides an insight into the formation of the subcontinent the orogeny the paleoenvironment and the exotic collection of paleo flora and fauna the details provided for the eparchaean unconformity monument indicate that this feature forms the boundary surface between proterozoic nagari quartzites and archaean granite the time gap between the formation of the two units is at least 500 ma at this location the boundary is between sedimentary rocks of the cudappah supergroup 1600 million years in age and archaean rocks comprising granites gneisses and dolerite dykes that are more than 2100 million years old this unconformity gives an indication of the enormous time gap in the creation of the earth ’ s crust
an ependymal tumor is a type of brain tumor that begins in cells lining the spinal cord central canal fluid filled space down the center or the ventricles fluid filled spaces of the brain ependymal tumors may also form in the choroid plexus tissue in the ventricles that makes cerebrospinal fluid also called ependymoma
ependymoma is a tumor that arises from the ependyma a tissue of the central nervous system usually in pediatric cases the location is intracranial while in adults it is spinal the common location of intracranial ependymoma is the fourth ventricle rarely ependymoma can occur in the pelvic cavity syringomyelia can be caused by an ependymoma ependymomas are also seen with neurofibromatosis type ii
ephemeralization a term coined by r buckminster fuller is the ability of technological advancement to do more and more with less and less until eventually you can do everything with nothing that is an accelerating increase in the efficiency of achieving the same or more output products services information etc while requiring less input effort time resources etc fuller s vision was that ephemeralization will result in ever increasing standards of living for an ever growing population despite finite resources the concept has been embraced by those who argue against malthusian philosophy fuller uses henry ford s assembly line as an example of how ephemeralization can continuously lead to better products at lower cost with no upper bound on productivity fuller saw ephemeralization as an inevitable trend in human development the progression was from compression to tension to visual to abstract electrical i e nonsensorial radiation such as radio waves x rays etc length measurement technologies in human development for example started with a compressive measure such as a ruler the compressive technique reached an upper limit with a rod for longer measures a tensive measure such as a string or rope was used this reached an upper limit with sagging of the string next was a surveyor ’ s telescope visual this reached an upper limit with curvature of the earth next was radio triangulation abstract electrical the technological progression is a continuing increase in length measuring ability per pound of instrument with no apparent upper limit according to fuller
ephialtes lit jumping on you is an anxiety disorder identified as such by john bond in 1753 along with other authors of those times in his treatise incubus the famous greek physician galen in the 2 nd century ad had already named nightmares ephialtes the idea of an incubus as a causative factor in nightmares stemmed from the belief that some spirit or ghostly person crept in during the night and lay upon the sleeper so as to constrict the chest and breathing — leading to a sense of suffocation side by side with a terrifying dream of being either crushed or in the case of a woman sexually violated by the male incubus or ephialtes sleepers thus set upon feel they are about to die — but as bond who was himself prone to nightmares stated as soon as they shake off that vast oppression they are affected with a strong palpitation great anxiety languour and uneasiness – which symptoms gradually abate and are succeeded by the pleasing reflection of having escaped such imminent danger p 3
epiblepharon is characterised by a congenital horizontal fold of skin near the margin of the upper or lower eyelid caused by the abnormal insertion of muscle fibres this extra fold of skin redirects the lashes into a vertical position where they may contact the globe this is found most commonly in asian individuals especially children
epicondylitis is a type of musculoskeletal disorder that refers to an inflammation of an epicondyle types include lateral epicondylitis also known as tennis elbow medial epicondylitis also known as golfer s elbow also thrower s elbow
epidemic dropsy is a form of edema of extremities due to poisoning by argemone mexicana mexican prickly poppy epidemic dropsy is a clinical state resulting from use of edible oils adulterated with argemone mexicana seed oil sanguinarine and dihydrosanguinarine are two major toxic alkaloids of argemone oil which cause widespread capillary dilatation proliferation and increased capillary permeability when mustard oil is adulterated deliberately as in most cases or accidentally with argemone oil proteinuria specifically loss of albumin occurs with a resultant edema as would occur in nephrotic syndrome other major symptoms are bilateral pitting edema of extremities headache nausea loose bowels erythema glaucoma and breathlessness leakage of the protein rich plasma component into the extracellular compartment leads to the formation of edema the haemodynamic consequences of this vascular dilatation and permeability lead to a state of relative hypovolemia with a constant stimulus for fluid and salt conservation by the kidneys illness begins with gastroenteric symptoms followed by cutaneous erythema and pigmentation respiratory symptoms such as cough shortness of breath and orthopnoea progressing to frank right sided congestive cardiac failure are seen mild to moderate anaemia hypoproteinaemia mild to moderate renal azotemia retinal haemorrhages and glaucoma are common manifestations there is no specific therapy removal of the adulterated oil and symptomatic treatment of congestive cardiac failure and respiratory symptoms along with administration of antioxidants and multivitamins remain the mainstay of treatment epidemic dropsy occurs as an epidemic in places where use of mustard oil from the seeds of brassica juncea commonly known as indian mustard as cooking medium is common
epidemic polyarthritis is an outdated term that was formerly used to refer to polyarthritis caused by two mosquito borne viruses endemic to australasia barmah forest virus which causes barmah forest fever ross river virus rrv which causes ross river fever
epidemic typhus also called camp fever jail fever hospital fever ship fever famine fever putrid fever petechial fever epidemic louse borne typhus and louse borne typhus is a form of typhus so named because the disease often causes epidemics following wars and natural disasters the causative organism is rickettsia prowazekii transmitted by the human body louse pediculus humanus humanus
the epidemiology of depression has been studied across the world depression is a major cause of morbidity worldwide as the epidemiology has shown lifetime prevalence varies widely from 3 in japan to 17 in the us in most countries the number of people who would suffer from depression during their lives falls within an 8 – 12 range in north america the probability of having a major depressive episode within any year long period is 3 – 5 for males and 8 – 10 for females
pneumonia is a common illness affecting approximately 450 million people a year and occurring in all parts of the world it is a major cause of death among all age groups resulting in 4 million deaths 7 of the worlds yearly total rates are greatest in children less than five and adults older than 75 years of age it occurs about five times more frequently in the developing world versus the developed world viral pneumonia accounts for about 200 million cases
epidermodysplasia verruciformis ev also called lewandowsky lutz dysplasia colloquially known as tree man illness is an extremely rare autosomal recessive genetic hereditary skin disorder associated with a high risk of carcinoma of the skin it is characterized by abnormal susceptibility to human papillomaviruses hpvs of the skin the resulting uncontrolled hpv infections result in the growth of scaly macules and papules particularly on the hands and feet it is typically associated with hpv types 5 and 8 which are found in about 80 of the normal population as asymptomatic infections although other types may also contribute the condition usually has an onset of between the ages of one and 20 but can occasionally present in middle age it is named after the physicians who first documented it felix lewandowsky and wilhelm lutz
an epidermoid cyst is a benign cyst usually found on the skin the cyst develops out of ectodermal tissue histologically it is made of a thin layer of squamous epithelium
epidermolysis bullosa eb is a group of inherited connective tissue diseases that cause blisters in the skin and mucosal membranes with an incidence of 20 per million newborns in the united states it is a result of a defect in anchoring between the epidermis and dermis resulting in friction and skin fragility its severity ranges from mild to lethal the condition was brought to public attention in 2004 in the uk through the channel 4 documentary the boy whose skin fell off chronicling the life and death of jonny kennedy an englishman with eb in the united states the same could be said of the hbo documentary my flesh and blood from 2003 butterfly children is a term often used to describe younger patients because the skin is said to be as fragile as a butterfly ’ s wings cotton wool babies or in south america as crystal skin children
epidermolysis bullosa acquisita is a chronic subepidermal blistering disease associated with autoimmunity to type vii collagen within anchoring fibril structures that are located at the dermoepidermal junction
epidermolysis bullosa dystrophica or dystrophic eb deb is an inherited disease affecting the skin and other organs butterfly children is the term given to those born with the disease as their skin is seen to be as delicate and fragile as that of a butterfly
epidermolysis bullosa simplex ebs is a disorder resulting from mutations in the genes encoding keratin 5 or keratin 14 blister formation of ebs occurs at the dermoepidermal junction sometimes ebs is called epidermolytic
epidermolytic acanthomas are a cutaneous condition characterized by discrete keratotic papules in adults
epidermolytic hyperkeratosis also known as bullous congenital ichthyosiform erythroderma bullous ichthyosiform erythroderma or bullous congenital ichthyosiform erythroderma brocq is a rare ichthyosis skin disease affecting around 1 in 250 000 people it involves the clumping of keratin filaments
epididymitis is a medical condition characterized by discomfort or pain of the epididymis a curved structure at the back of the testicle in which sperm matures and is stored epididymitis is usually characterized as either acute or chronic if acute the onset of testicular pain is often accompanied by inflammation redness and warmth in the scrotum if chronic pain may be the only symptom in either form testicular pain in one or both testes can vary from mild to severe and one or both epididymides may noticeably swell inflame and or harden indurate the pain is often cyclical and may last from less than an hour to several days epididymitis is the most frequent cause of acute onset scrotal pain in adults in contrast with men who have testicular torsion the cremasteric reflex elevation of the testicle in response to stroking the upper inner thigh is not altered if the diagnosis is not entirely clear from the patient s history and physical examination a doppler ultrasound scan can confirm increased flow of blood to the affected epididymis whereas torsion is characterized by ischemia if the inflammation spreads to the testicle the condition may be reclassified as epididymo orchitis or orchiepididymitis the swelling from epididymitis may stretch along the inguinal canal and may appear similar to that of a hernia particularly an inguinal hernia it may be distinguished from these however in that with the exception of an incarcerated indirect inguinal hernia inguinal hernias generally are not painful and the swelling they produce often disappears upon lying down neither is the case with epididymitis also hernias are not episodic whereas epididymitis frequently is
epidural or extradural hematoma haematoma also known as an epidural hemorrhage is a type of traumatic brain injury tbi in which a buildup of blood occurs between the dura mater the tough outer membrane of the central nervous system and the skull the spinal cord is also covered by a layer of dura mater so epidural bleeds may also occur in the spinal column often due to trauma the condition is potentially deadly because the buildup of blood may increase pressure in the intracranial space compress delicate brain tissue and cause brain shift the condition is present in one to three percent of head injuries around 15 20 of epidural hematomas are fatal
an epigastric hernia is a type of hernia which may develop in the epigastrium upper central part of the abdomen epigastric hernias usually appear in adults unlike the benign diastasis recti epigastric hernia may trap fat and other tissues inside the opening of the hernia causing pain and tissue damage
in the last few years chemical alterations in the genome have become more evident and these alterations can be critical in the development of malignancy this alteration process is referred to as epigenetics patino et al 2008 epigenetics is the term used to refer to stable changes in dna that affect gene expression but do not involve changes in the underlying nucleotide sequence of the organism patino et al 2008 the mechanisms by which epigenetics occur involve hypo and hypermethylation of dna histone modifications by acetylation methylation and phosphorylation and posttranslational modifications which include rna silencing these modifications can cause different expression patterns to occur which can result in alterations to cells some of these alterations could result in the formation of cancerous cells or various other dangerous changes in cell function among many other outcomes when paired together cancerous cells are not formed from just one change
depression is a serious behavioral disorder causing long lasting feelings of sadness and loss of interest one form of depression is major depressive disorder mdd in which symptoms of depression are present most days a week for 2 weeks or longer depression affects a large aspect of day to day activities such as thought process sleep and appetite it can be accompanied by anxiety and decreased energy according to the world health organization depression affects about 350 million people worldwide and is the major cause of disability depression can be caused by the interaction of environmental and genetic factors these factors include epigenetic modification of the genome in which there is a persistent change in gene expression without a change in the actual dna sequence
epiglottitis is inflammation of the epiglottis — the flap at the base of the tongue that keeps food from going into the trachea windpipe symptoms are usually rapid in onset and include trouble swallowing which can result in drooling changes to the voice fever and an increased breathing rate as the epiglottis is in the upper airway swelling can interfere with breathing people may lean forward in an effort to open the airway as the condition worsens stridor and bluish skin may occur epiglottitis was historically mostly caused by infection by h influenzae type b with vaccination it is now more often caused by other bacteria other possible causes include burns and trauma to the area the most accurate way to make the diagnosis is to look directly at the epiglottis x rays of the neck from the side may show a thumbprint sign but the lack of this sign does not mean the condition is absent an effective vaccine the hib vaccine has been available since the 1980 s the antibiotic rifampin may also be used to prevent the disease among those who have been exposed to the disease and are at high risk the most important part of treatment involves securing the airway which is often done by endotracheal intubation intravenous antibiotics such as ceftriaxone and possibly vancomycin or clindamycin is then given corticosteroids are also typically used with appropriate treatment the risk of death among children with the condition is about one percent and among adults is seven percent with the use of the hib vaccine the number of cases of epiglottitis has decreased by more than 95 while historically young children were mostly affected it is now more common among older children and adults in the united states it affects about 1 3 per 100 000 children a year in adults between 1 and 4 per 100 000 are affected a year it occurs more commonly in the developing world
epilepsia partialis continua also called kojevnikov s or kozhevnikov s epilepsia is a rare type of brain disorder in which a patient experiences recurrent motor epileptic seizures that are focal hands and face and recur every few seconds or minutes for extended periods days or years
epilepsy is a group of neurological diseases characterized by epileptic seizures epileptic seizures are episodes that can vary from brief and nearly undetectable to long periods of vigorous shaking these episodes can result in physical injuries including occasionally broken bones in epilepsy seizures tend to recur and have no immediate underlying cause isolated seizures that are provoked by a specific cause such as poisoning are not deemed to represent epilepsy people with epilepsy in some areas of the world experience stigma due to the condition the cause of most cases of epilepsy is unknown although some people develop epilepsy as the result of brain injury stroke brain tumors infections of the brain and birth defects known genetic mutations are directly linked to a small proportion of cases epileptic seizures are the result of excessive and abnormal nerve cell activity in the cortex of the brain the diagnosis involves ruling out other conditions that might cause similar symptoms such as fainting and determining if another cause of seizures is present such as alcohol withdrawal or electrolyte problems this may be partly done by imaging the brain and performing blood tests epilepsy can often be confirmed with an electroencephalogram eeg but a normal test does not rule out the condition epilepsy that occurs as a result of other issues may be preventable seizures are controllable with medication in about 70 of cases inexpensive options are often available in those whose seizures do not respond to medication then surgery neurostimulation or dietary changes may be considered not all cases of epilepsy are lifelong and many people improve to the point that treatment is no longer needed as of 2013 about 22 million people have epilepsy nearly 80 of cases occur in the developing world in 2013 it resulted in 116 000 deaths up from 112 000 deaths in 1990 epilepsy is more common in older people in the developed world onset of new cases occurs most frequently in babies and the elderly in the developing world onset is more common in older children and young adults due to differences in the frequency of the underlying causes about 5 – 10 of people will have an unprovoked seizure by the age of 80 and the chance of experiencing a second seizure is between 40 and 50 in many areas of the world those with epilepsy either have restrictions placed on their ability to drive or are not permitted to drive until they are free of seizures for a specific length of time the word epilepsy is from ancient greek ἐεπιλαμβάνειν to seize possess or afflict
epilepsy intellectual disability in females also known as pcdh 19 gene related epilepsy or epileptic encephalopathy early infantile 9 eiee 9 is a rare type of epilepsy that affects predominately females and is characterized by clusters of brief seizures which start in infancy or early childhood and is occasionally accompanied by varying degrees of cognitive impairment the striking pattern of onset seizures at a young age genetic testing and laboratory results potential developmental delays or developmental regression and associated disorders eases diagnosis the national institutes of health office and rare disease research characterizes pcdh 19 gene related epilepsy as a rare disorder although formal epidemiologic data is not available results from diagnostic screenings indicate that approximately 1 out of 10 girls who have seizure onset before five years of age may have pcdh 19 mutations
an epileptic seizure colloquially a fit is a brief episode of signs or symptoms due to abnormal excessive or synchronous neuronal activity in the brain the outward effect can vary from uncontrolled jerking movement tonic clonic seizure to as subtle as a momentary loss of awareness absence seizure diseases of the brain characterized by an enduring predisposition to generate epileptic seizures are collectively called epilepsy seizures can also occur in people who do not have epilepsy for various reasons including brain trauma drug use elevated body temperature hypoglycemia low blood sugar levels and hypoxia low levels of oxygen to the brain additionally there are a number of conditions that look like epileptic seizures but are not a first seizure generally does not require long term treatment with anti seizure medications unless there is a specific problem on either electroencephalogram or brain imaging 5 – 10 of people who live to 80 years old have at least one epileptic seizure and the chance of experiencing a second seizure is between 40 and 50 about 50 of patients with an unprovoked apparent first seizure have had other minor seizures so their diagnosis is epilepsy epilepsy affects about 1 of the population currently and affected about 4 of the population at some point in time most of those affected — nearly 80 — live in developing countries
epileptic spasms infantile spasms juvenile spasms or west syndrome is an uncommon to rare epileptic disorder in infants children and adults it is named after the english physician william james west 1793 – 1848 who first described it in an article published in the lancet in 1841 the original case actually described his own son james edwin west 1840 – 1860 other names for it are generalized flexion epilepsy infantile epileptic encephalopathy infantile myoclonic encephalopathy jackknife convulsions massive myoclonia and salaam spasms the term infantile spasms can be used to describe the specific seizure manifestation in the syndrome but is also used as a synonym for the syndrome itself west syndrome in modern usage is the triad of infantile spasms a pathognomonic eeg pattern called hypsarrhythmia and developmental regression although the international definition requires only two out of these three elements the syndrome is age related generally occurring between the third and the twelfth month generally manifesting around the fifth month there are various causes polyetiology the syndrome is often caused by an organic brain dysfunction whose origins may be prenatal perinatal caused during birth or postnatal
an epiphenomenon plural epiphenomena is a secondary phenomenon that occurs alongside or in parallel to a primary phenomenon the word has two senses one that connotes known causation and one that connotes absence of causation or reservation of judgment about it
epiploic appendagitis ea is an uncommon benign non surgical self limiting inflammatory process of the epiploic appendices other older terms for the process include appendicitis epiploica and appendagitis but these terms are used less now in order to avoid confusion with acute appendicitis epiploic appendices are small fat filled sacs or finger like projections along the surface of the upper and lower colon and rectum they may become acutely inflamed as a result of torsion twisting or venous thrombosis the inflammation causes pain often described as sharp or stabbing located on the left right or central regions of the abdomen there is sometimes nausea and vomiting the symptoms may mimic those of acute appendicitis diverticulitis or cholecystitis the pain is characteristically intense during after defecation or micturition espec in the segmoid type due to the effect of traction on the pedicle of the lesion caused by straining and emptying of the bowel and bladder initial lab studies are usually normal ea is usually diagnosed incidentally on ct scan which is performed to exclude more serious conditions although it is self limiting epiploic appendagitis can cause severe pain and discomfort it is usually thought to be best treated with an anti inflammatory and a moderate to severe pain medication depending on the case as needed surgery is not recommended in nearly all cases sand and colleagues however recommend laparascopic surgery to excise the inflamed appendage in most cases in order to prevent recurrence
epiretinal membrane is a disease of the eye in response to changes in the vitreous humor or more rarely diabetes it is also called macular pucker sometimes as a result of immune system response to protect the retina cells converge in the macular area as the vitreous ages and pulls away in posterior vitreous detachment pvd pvd can create minor damage to the retina stimulating exudate inflammation and leucocyte response these cells can form a transparent layer gradually and like all scar tissue tighten to create tension on the retina which may bulge and pucker e g macular pucker or even cause swelling or macular edema often this results in distortions of vision that are clearly visible as bowing ← → when looking at lines on chart paper or an amsler grid within the macular area or central 1 0 degree of visual arc usually it occurs in one eye first and may cause binocular diplopia or double vision if the image from one eye is too different from the image of the other eye the distortions can make objects look different in size usually larger macropsia especially in the central portion of the visual field creating a localized or field dependent aniseikonia that cannot be fully corrected optically with glasses partial correction often improves the binocular vision considerably though in the young under 50 years of age these cells occasionally pull free and disintegrate on their own but in the majority of sufferers over 60 years of age the condition is permanent the underlying photoreceptor cells rod cells and cone cells are usually not damaged unless the membrane becomes quite thick and hard so usually there is no macular degeneration
episcleritis is a benign self limiting inflammatory disease affecting part of the eye called the episclera the episclera is a thin layer of tissue that lies between the conjunctiva and the connective tissue layer that forms the white of the eye sclera episcleritis is a common condition and is characterized by the abrupt onset of mild eye pain and redness there are two types of episcleritis one where the episclera is diffusely affected diffuse episcleritis and the other where nodules are present in the episclera nodular episcleritis most cases have no identifiable cause although a small fraction of cases are associated with various systemic diseases often people with episcleritis experience it recurrently treatment focuses on decreasing discomfort and includes lubricating eye drops more severe cases may be treated with topical corticosteroids or oral anti inflammatory medications nsaids
episodic ataxia ea is an autosomal dominant disorder characterized by sporadic bouts of ataxia severe discoordination with or without myokymia continuous muscle movement there are seven types recognised but the majority are due to two recognized entities ataxia can be provoked by stress startle or heavy exertion such as exercise symptoms can first appear in infancy there are at least 6 loci for ea of which 4 are known genes some patients with ea also have migraine or progressive cerebellar degenerative disorders symptomatic of either familial hemiplegic migraine or spinocerebellar ataxia some patients respond to acetazolamide though others do not
episodic dyscontrol syndrome eds or sometimes just dyscontrol is a pattern of abnormal episodic and frequently violent and uncontrollable social behavior in the absence of significant provocation it can result from limbic system diseases disorders of the temporal lobe or abuse of alcohol or other psychoactive substances eds may affect children or adults
episodic tremor and slip ets is a seismological phenomenon observed in some subduction zones these events are characterized by non earthquake seismic rumbling or tremor and slow slip along the plate interface slow slip events are distinguished from earthquakes by their propagation speed and focus in slow slip events there is an apparent reversal of crustal motion although the fault motion remains consistent with the direction of subduction ets events themselves are imperceptible to human beings and do not cause damage
an epispadias is a rare type of malformation of the penis in which the urethra ends in an opening on the upper aspect the dorsum of the penis it can also develop in females when the urethra develops too far anteriorly it occurs in around 1 in 120 000 male and 1 in 500 000 female births
epistasis is the phenomenon of the effect of one gene being dependent on the presence of one or more modifier genes the genetic background thus epistatic mutations have different effects in combination than individually it was originally a concept from genetics but is now used in biochemistry computational biology and evolutionary biology it arises due to interactions either between genes or within them leading to non additive effects epistasis has a large influence on the shape of evolutionary landscapes which leads to profound consequences for evolution and evolvability of phenotype traits
epistemic modal logic is a subfield of modal logic that is concerned with reasoning about knowledge while epistemology has a long philosophical tradition dating back to ancient greece epistemic logic is a much more recent development with applications in many fields including philosophy theoretical computer science artificial intelligence economics and linguistics while philosophers since aristotle have discussed modal logic and medieval philosophers such as ockham and duns scotus developed many of their observations it was c i lewis who created the first symbolic and systematic approach to the topic in 1912 it continued to mature as a field reaching its modern form in 1963 with the work of kripke
epithelial myoepithelial carcinoma abbreviated emca is a rare malignant tumour that typically arises in a salivary gland and consists of both an epithelial and myoepithelial component they are predominantly found in the parotid glandand represent approximately 1 of salivary gland tumours
epithelial basement membrane dystrophy ebmd also known as map dot fingerprint dystrophy and cogans s microcystic dystrophy is a disorder of the eye that can cause pain and dryness it is sometimes included in the group of corneal dystrophies it diverges from the formal definition of corneal dystrophy in being in most cases non familial it also has a fluctuating course while for a typical corneal dystrophy the course is progressive when it is considered part of this group it is the most common type of corneal dystrophy
epithelial dysplasia a term becoming increasingly referred to as intraepithelial neoplasia is the sum of various disturbances of epithelial proliferation and differentiation as seen microscopically individual cellular features of dysplasia are called epithelial atypia
the hertwig epithelial root sheath hers or epithelial root sheath is a proliferation of epithelial cells located at the cervical loop of the enamel organ in a developing tooth hertwig epithelial root sheath initiates the formation of dentin in the root of a tooth by causing the differentiation of odontoblasts from the dental papilla the root sheath eventually disintegrates with the periodontal ligament but residual pieces that do not completely disappear are seen as epithelial cell rests of malassez erm these rests can become cystic presenting future periodontal infections
epithelioid cell histiocytoma is a rare skin condition that is considered to be a variant of a dermatofibroma
epithelioid hemangioendothelioma ehae is a rare tumor first characterized by sharon weiss and franz enzinger that both clinically and histologically is intermediate between angiosarcoma and hemangioma however a distinct disease defining genetic alteration recently described for ehe indicates that it is an entirely separate entity from both angiosarcoma and hemangioma ehe is a soft tissue sarcoma and is generally considered a vascular cancer insofar as the ‘ lesional ’ cells have surface markers typical of endothelial cells cells lining the interior of blood vessels ehe was originally described as occurring most commonly in the veins of the extremities arms and legs and two organs the liver and lungs it has since been described in organs throughout the body in addition to liver and lungs bones and skin have been the most frequent organs before the initial description of weiss the tumor had been reported under a variety of other names including histiocytoid hemangioendothelioma intravascular bronchoalveolar tumor in the lung and sclerosing cholangiocarcinoma in the lung and liver common sites of metastatic tumor it was most likely to be confused with carcinoma a far more common type of tumor ehe typically occurs in the 20 40 age range although the overall age range involved is much broader and a modest predilection for females over males it often has an indolent course and many affected people have survived for decades with multi organ disease 1 601 the extent and number of organs involved apparently has little effect on longevity
epithelioid sarcoma is a rare soft tissue sarcoma arising from mesenchymal tissue and characterized by epithelioid like features it accounts for less than 1 of all soft tissue sarcomas it was first clearly characterized by f m enzinger in 1970 it commonly presents itself in the distal limbs fingers hands forearms or feet of young adults as a small soft mass or a series of bumps a proximal version has also been described frequently occurring in the upper extremities rare cases have been reported in the pelvis vulva penis and spine histologically epithelioid sarcoma forms nodules with central necrosis surrounded by bland polygonal cells with eosinophilic cytoplasm and peripheral spindling epithelioid sarcomas typically express vimentin cytokeratins epithelial membrane antigen and cd 34 whereas they are usually negative for s 100 desmin and fli 1 they typically stain positive for ca 125 epithelioid sarcoma most commonly strikes young adults yet no age group is immune the disease has a tendency to develop local recurrences and metastasis thereafter to regional lymph nodes lung bone brain and other locations including the scalp generally speaking epithelioid sarcoma has a high rate of relapse after initial treatment and tends to recur locally at or near the original tumor site epithelioid sarcoma also demonstrates lymphatic spread in 22 48 of cases and metastasis in 21 63 of cases these events as well as advanced stage progression and grade aggressiveness are predictive of an overall worse outcome the overall five year survival rate for epithelioid sarcoma is anywhere from 25 to 78 importantly the 10 year and 15 year survival rate drops off significantly associated with a more positive outcome are younger age female vs male sex distal vs proximal location smaller tumor size and negative margins upon tumor resection
epithelioma is an abnormal growth of the epithelium which is the layer of tissue that covers the surfaces of organs and other structures of the body
epithelioma cuniculatum also known as carcinoma cuniculatum and ackerman tumor is a skin lesion a type of verrucous carcinoma that may occur on the sole of the foot
epizootic hemorrhagic disease ehd is a hemorrhagic disease of white tailed deer odocoileus virginianus caused by an infection of a virus from the genus orbivirus shope et al 1960 howarth et al 2001 it is an infectious and sometimes fatal virus that is characterized by extensive hemorrhages and is found throughout the united states it is important for deer hunters farmers farm property owners and livestock owners to have knowledge about ehd because of the seriousness of this disease its ability to cause large scale outbreaks in wild ruminants and its ability to affect livestock and the production industry ehd in white tailed deer michigan wildlife disease manual epizootic hemorrhagic disease has been found in some domestic ruminants and many species of deer including white tailed deer mule deer and pronghorn antelope cfsph 2006 seropositive black tailed deer fallow deer red deer wapiti and roe deer have also been found which essentially means that they were exposed to the disease at some time in the past but may not be involved in transmission outbreaks of ehd have been reported in cattle although it is rare for them to develop disease or die sheep may develop clinical signs however this is also rare howarth et al 2001 epizootic hemorrhagic disease is often called bluetongue however this is incorrect bluetongue virus is closely related to ehd and has similar clinical signs but it is a different disease bluetongue is a serious disease in cattle as well as other ruminants and can have a significant effect on international trade testing at animal health laboratories is necessary to distinguish between the viruses that cause bluetongue and ehd
epizootic lymphangitis is a contagious lymphangitis disease of horses and mules caused by the fungus histoplasma farciminosum cattle are also susceptible but more resistant to the disease than equids see also glanders and equine lymphangitis
epizootic ulcerative syndrome eus is a disease caused by the water mould aphanomyces invadans it infects many freshwater and brackish fish species in the asia pacific region and australia the disease is most commonly seen when there are low temperature and heavy rainfall in tropical and sub tropical waters it may also be referred to as mycotic granulomatosis mg and red spot disease rsd
in econometrics and time series analysis the epps effect named after t w epps is the phenomenon that the empirical correlation between the returns of two different stocks decreases as the sampling frequency of data increases the phenomenon is caused by non synchronous asynchronous trading and discretization effects however a current study shows that the effect originates in investors herd behaviour
epstein – barr virus positive dlbcl of the elderly is a type of large b cell lymphoma recognized in the who 2008 classification it is usually cd 20 positive and has clonal immunoglobulin gene rearrangement
there are several forms of epstein – barr virus infection infectious mononucleosis nasopharyngeal carcinoma and burkitt s lymphoma can all be caused by the epstein – barr virus
epulis plural epulides is any tumor like enlargement i e lump situated on the gingival or alveolar mucosa the word literally means on the gingiva and describes only the location of the mass and has no further implications on the nature of the lesion there are three types fibromatous ossifying and acanthomatous the related term parulis commonly called a gumboil refers to a mass of inflamed granulation tissue at the opening of a draining sinus on the alveolus over or near to the root of an infected tooth another closely related term is gingival enlargement which tends to be used where the enlargement is more generalized over the whole gingiva rather than a localized mass
epulis fissuratum also termed inflammatory fibrous hyperplasia denture induced fibrous inflammatory hyperplasia denture injury tumor denture epulis denture induced granuloma and granuloma fissuratum is a benign hyperplasia of fibrous connective tissue which develops as a reactive lesion to chronic mechanical irritation produced by the flange of a poorly fitting denture more simply epulis fissuratum is where excess folds of firm tissue form inside the mouth as a result of rubbing on the edge of dentures that do not fit well it is a harmless condition and does not represent oral cancer treatment is by simple surgical removal of the lesion and also by adjustment of the denture or provision of a new denture it is a closely related condition to inflammatory papillary hyperplasia but the appearance and location differs
in two body keplerian orbital mechanics the equation of the center is the angular difference between the actual position of a body in its elliptical orbit and the position it would occupy if its motion were uniform in a circular orbit of the same period it is defined as the difference true anomaly ν minus mean anomaly m and is typically expressed a function of mean anomaly m and orbital eccentricity e
equatorial plasma bubbles are an ionospheric phenomenon near the earth s geomagnetic equator at night time they affect radio waves by causing varying delays they degrade the performance of gps different times of the year and location have different frequencies of occurrence in northern australia the most common times are february to april and august to october when a plasma bubble is expected every night plasma bubbles have dimensions around 100 km plasma bubbles form after dark when the sun stops ionising the ionosphere the ions recombine forming a lower density layer this layer can rise through the more ionised layers above via convection which makes a plasma bubble the bubbles are turbulent with irregular edges an equatorial plasma bubble could have affected the battle of shah i kot by disabling communications from a communications satellite to a helicopter
equestrian perniosis is a skin condition that presents on the lateral thighs of women equestrians who ride on cold damp days
equilibrium isotope fractionation is the partial separation of isotopes between two or more substances in chemical equilibrium equilibrium fractionation is strongest at low temperatures and along with kinetic isotope effects forms the basis of the most widely used isotopic paleothermometers or climate proxies d h and 18 o 16 o records from ice cores and 18 o 16 o records from calcium carbonate it is thus important for the construction of geologic temperature records isotopic fractionations attributed to equilibrium processes have been observed in many elements from hydrogen d h to uranium 238 u 235 u in general the light elements especially hydrogen boron carbon nitrogen oxygen and sulfur are most susceptible to fractionation and their isotopes tend to be separated to a greater degree than heavier elements
equine atypical myopathy also known as atypical myoglobinuria or eam is a mortal disease of horses equidae characterized by acute rhabdomyolysis it is believed to be caused by the ingestion of the seeds or young shoots of acer pseudoplatanus in europe and acer negundo in america eam has a high mortality rate and numerous fatalities have occurred
equine exertional rhabdomyolysis er also known as tying up azoturia or monday morning disease is a syndrome that damages the muscle tissue in horses it is usually due to overfeeding a horse carbohydrates and appears to have a genetic link
equine gastric ulcer syndrome egus is a common cause of colic and decreased performance in horses horses form ulcers in the mucosa of the stomach leading to pain decreased appetite weight loss and behavioral changes treatment generally involves reducing acid production of the stomach and dietary management unlike some animals however stomach rupture is rare and the main goal of treating is to reduce pain and improve performance of animals used for showing or racing
equine infectious anemia or equine infectious anaemia eia also known by horsemen as swamp fever is a horse disease caused by a retrovirus and transmitted by bloodsucking insects the virus eiav is endemic in the americas parts of europe the middle and far east russia and south africa the virus is a lentivirus like human immunodeficiency virus hiv like hiv eia can be transmitted through blood milk and body secretions transmission is primarily through biting flies such as the horse fly and deer fly the virus survives up to 4 hours in the carrier contaminated surgical equipment and recycled needles and syringes and bits can transmit the disease mares can transmit the disease to their foals via the placenta the risk of transmitting the disease is greatest when an infected horse is ill as the blood levels of the virus are then highest
equine influenza horse flu is the disease caused by strains of influenza a that are enzootic in horse species equine influenza occurs globally previously caused by two main strains of virus equine 1 h 7 n 7 and equine 2 h 3 n 8 the oie now considers h 7 n 7 strains likely to be extinct since these stains have not been isolated for over 20 years predominant international circulating h 3 n 8 strains are florida sublineage of the american lineage clade 1 predominates in the americas and clade 2 in europe elton and cullinane 2013 paillot 2014 slater et al 2013 the disease has a nearly 100 infection rate in an unvaccinated horse population with no prior exposure to the virus while equine influenza is historically not known to affect humans impacts of past outbreaks have been devastating due to the economic reliance on horses for communication postal service military cavalry and general transportation in modern times though the ramifications of equine influenza are most clear in the horse racing industry
equine lymphangitis is an inflammation or swelling associated with impairment of the lymphatic system particularly in a limb in horses it is most commonly a bacterial infection although bacterial culture may be negative often referred to as fat big leg disease it is sometimes known as weed or monday morning disease not to be confused with the more common usage of mmd referring to exertional rhabdomyolysis or azoturia this article refers mainly to sporadic lymphangitis ulcerative lymphangitis is referred to in passing as it is managed in a similar manner epizootic lymphangitis is similar to glanders but caused by the fungus histoplasma farciminosum
equine multinodular pulmonary fibrosis is a chronic lung disease of horses there is evidence that the disease is caused by infection with a gammaherpesvirus equine herpesvirus 5 the disease affects adult usually older horses causing weight loss and reduced ability to exercise as a result of the formation of nodular lesions in the lungs
equine polysaccharide storage myopathy epsm pssm epssm is an inheritable glycogen storage disease of horses that causes exertional rhabdomyolysis it is most commonly associated with heavy horse breeds and the american quarter horse while incurable pssm can be managed with appropriate diet and exercise there are currently 2 subtypes known as type 1 pssm and type 2 pssm
equine protozoal myeloencephalitis epm is a disease caused by the apicomplexan parasite sarcocystis neurona that affects the central nervous system of horses
proximal enteritis also known as anterior enteritis or duodenitis proximal jejunitis dpj is inflammation of the duodenum and upper jejunum it produces a functional stasis of the affected intestine ileus and hypersecretion of fluid into the lumen of that intestine this leads to large volumes of gastric reflux dehydration low blood pressure and potentially shock although the exact cause is not yet definitively known proximal enteritis requires considerable supportive care
equine recurrent periodic uveitis moon blindness recurrent iridocyclitis is an acute nongranulomatous inflammation of the uveal tract of the eye occurring commonly in horses of all breeds worldwide the causative factor is not known but several pathogeneses have been suggested it is the most common cause of blindness in horses in some breeds a genetic factor may be involved
shivers or equine shivering is a rare progressive neuromuscular disorder of horses it is characterized by muscle tremors difficulty holding up the hind limbs and an unusual gait when the horse is asked to move backwards shivers is poorly understood and no effective treatment is available at this time
equine viral arteritis eva is a disease of horses caused by an rna virus of the genus arterivirus the virus which causes eva was first isolated from horses in ohio in 1953 but the disease has afflicted equine animals worldwide for centuries it has been more common in some breeds of horses in the united states but there is no breed “ immunity ” in the uk it is a notifiable disease there is no known human hazard
an equinovalgus is a deformity of the human foot it may be a flexible deformity or a fixed deformity equino means plantarflexed as in standing on one s toes and valgus means that the base of the heel is rotated away from the midline of the foot eversion and abduction of foot this means that the patient is placing his her weight on the medial border of the foot and the arch of the foot is absent which distorts the foot s normal shape mainly occurs due to tightness of plantar flexors calf muscles and peroneus group of muscles
the equioscillation theorem concerns the approximation of continuous functions using polynomials when the merit function is the maximum difference uniform norm its discovery is attributed to chebyshev
in accounting and finance equity is the difference between the value of the assets and the cost of the liabilities of something owned for example if someone owns a car worth 15 000 but owes 5 000 on a loan against that car the car represents 10 000 equity equity can be negative if liability exceeds assets in an accounting context shareholders equity or stockholders equity shareholders funds shareholders capital or similar terms represents the equity of a company as divided among shareholders of common or preferred stock negative shareholders equity is often referred to as a shareholders deficit for purposes of liquidation during bankruptcy ownership equity is the equity which remains after all liabilities have been paid
equity of condition in tax law and governmental spending is the economic condition often arbitrary that political leaders believe a person should be in after governmental social engineering and redistribution of wealth the award or redistribution of wealth to the recipients overrides substantially any natural right of the producers of the wealth to keep the fruits of their labor the award of wealth in a socialist economy may be extensive with a proscribed level of benefits for food housing health education recreation welfare etcetera — and have little or no relation to the citizen ’ s productivity e g before tax income the result however is that economic productivity and the standard of living can be lessened in a socialist economy due to disincentive to production equity of condition in a mixed economy such as the united states can be nebulous and ever changing governmental subsidies and tax deductions may be extended for political reasons and a political leader may never provide comprehensive economic rationale for his particular fiscal policy actions the cost of the benefits is merely shifted to a discriminated portion of the tax base benefits may also be illusory to recipients because further political manipulation of the tax code by political leaders can nullify the recipients ’ original gains
in telecommunication equivalent pulse code modulation noise pcm is the amount of thermal noise power on a frequency division multiplexing fdm or wire channel necessary to approximate the same judgment of speech quality created by quantizing noise in a pcm channel note 1 the speech quality judgment is based on comparative tests note 2 generally 33 5 dbrnc ± 2 5 db is considered the approximate equivalent pcm noise of a 7 bit pcm system
in algebraic number theory an equivariant artin l function is a function associated to a finite galois extension of global fields created by packaging together the various artin l functions associated with the extension each extension has many traditional artin l functions associated with it corresponding to the characters of representations of the galois group by contrast each extension has a unique corresponding equivariant l function equivariant l functions have become increasingly important as a wide range of conjectures and theorems in number theory have been developed around them among these are the brumer – stark conjecture the coates sinnott conjecture and a recently developed equivariant version of the main conjecture in iwasawa theory
in mathematics more specifically in topology the equivariant stable homotopy theory is a subfield of equivariant topology that studies a spectrum with group action instead of a space with group action as in stable homotopy theory the field has become more active recently because of its connection to algebraic k theory
erb s palsy or erb – duchenne palsy is a paralysis of the arm caused by injury to the upper group of the arm s main nerves specifically the severing of the upper trunk c 5 – c 6 nerves these form part of the brachial plexus comprising the ventral rami of spinal nerves c 5 – c 8 and thoracic nerve t 1 these injuries arise most commonly but not exclusively from shoulder dystocia during a difficult birth depending on the nature of the damage the paralysis can either resolve on its own over a period of months necessitate rehabilitative therapy or require surgery
erdheim – chester disease also known as erdheim – chester syndrome or polyostotic sclerosing histiocytosis is a rare disease characterized by the abnormal multiplication of a specific type of white blood cells called histiocytes or tissue macrophages technically this disease is termed a non langerhans cell histiocytosis usually onset is in middle age the disease involves an infiltration of lipid laden macrophages multinucleated giant cells an inflammatory infiltrate of lymphocytes and histiocytes in the bone marrow and a generalized sclerosis of the long bones
in mathematics the erdős – burr conjecture is a problem concerning the ramsey number of sparse graphs the conjecture is named after paul erdős and stefan burr and is one of many conjectures named after erdős it states that the ramsey number of graphs in any sparse family of graphs should grow linearly in the number of vertices of the graph in 2015 a proof of the conjecture was announced by choongbum lee
in graph theory the erdős – faber – lovász conjecture is an unsolved problem about graph coloring named after paul erdős vance faber and lászló lovász who formulated it in 1972 it says if k complete graphs each having exactly k vertices have the property that every pair of complete graphs has at most one shared vertex then the union of the graphs can be colored with k colors
in the mathematical discipline of graph theory the erdős – pósa theorem named after paul erdős and lajos pósa states that there is a function f k such that for each positive integer k every graph either contains k vertex disjoint circuits or it has a feedback vertex set of f k vertices that intersects every circuit furthermore f k o k log k in the sense of big o notation because of this theorem circuits are said to have the erdős – pósa property the theorem claims that for any finite number k there is an appropriate least value f k with the property that every graph with no k vertex disjoint circuits all circuits can be covered by f k vertices this generalized an unpublished result of béla bollobás which states that f 2 3 obtained the bounds c 1 k log k f k c 2 k log k for the general case the result suggests that although there are infinitely many different graphs with no k disjoint circuits they split into finitely many simply describable classes for the case k 2 gave a complete characterization proved f 3 6 and 9 ≤ f 4 ≤ 12
erectile dysfunction ed or impotence is sexual dysfunction characterized by the inability to develop or maintain an erection of the penis during sexual activity in humans a penile erection is the hydraulic effect of blood entering and being retained in sponge like bodies within the penis the process is most often initiated as a result of sexual arousal when signals are transmitted from the brain to nerves in the penis the most important organic causes of impotence are cardiovascular disease and diabetes neurological problems for example trauma from prostatectomy surgery hormonal insufficiencies hypogonadism and drug side effects psychological impotence is where erection or penetration fails due to thoughts or feelings psychological reasons rather than physical impossibility this is somewhat less frequent but can often be helped notably in psychological impotence there is a strong response to placebo treatment erectile dysfunction can have severe psychological consequences as it can be tied to relationship difficulties and masculine self image besides treating the underlying causes such as potassium deficiency or arsenic contamination of drinking water the first line treatment of erectile dysfunction consists of a trial of pde 5 inhibitor drugs the first of which was sildenafil or viagra in some cases treatment can involve prostaglandin tablets in the urethra injections into the penis a penile prosthesis a penis pump or vascular reconstructive surgery
an erection clinically penile erection or penile tumescence is a physiological phenomenon in which the penis becomes firmer engorged and enlarged penile erection is the result of a complex interaction of psychological neural vascular and endocrine factors and is often associated with sexual arousal or sexual attraction although erections can also be spontaneous the shape angle and direction of an erection varies considerably in humans physiologically erection is triggered by the parasympathetic division of the autonomic nervous system ans causing nitric oxide a vasodilator levels to rise in the trabecular arteries and smooth muscle of the penis the arteries dilate causing the corpora cavernosa of the penis and to a lesser extent the corpora spongiosum to fill with blood simultaneously the ischiocavernosus and bulbospongiosus muscles compress the veins of the corpora cavernosa restricting the egress and circulation of this blood erection subsides when parasympathetic activity reduces to baseline as an autonomic nervous system response an erection may result from a variety of stimuli including sexual stimulation and sexual arousal and is therefore not entirely under conscious control erections during sleep or upon waking up are known as nocturnal penile tumescence npt absence of nocturnal erection is commonly used to distinguish between physical and psychological causes of erectile dysfunction and impotence a penis which is partly but not fully erect is sometimes known as a semi erection clinically partial tumescence a penis which is not erect is typically referred to as being flaccid or soft
erethism or erethism mercurialis is a neurological disorder which affects the whole central nervous system as well as a symptom complex derived from mercury poisoning this is also sometimes known as the mad hatter disease historically this was common among old england felt hatmakers who used mercury to stabilize the wool in a process called felting where hair was cut from a pelt of an animal such as a rabbit the industrial workers were exposed to the mercury vapors giving rise to the expression “ mad as a hatter ” some believe that the character the mad hatter in lewis carroll s alice in wonderland is an example of someone suffering from erethism but the origin of this account is unclear the character was almost certainly based on theophilus carter an eccentric furniture dealer who was well known to carroll it is commonly characterized through behavioral changes such as irritability low self confidence depression apathy shyness and timidity and in some extreme cases with prolonged exposure to mercury vapors delirium personality changes and memory loss occur as a result people with erethism find it difficult to interact socially with others with behaviors similar to that of a social phobia although most of the effects of erethism are neurological some physical problems arise as well including a decrease in physical strength “ headaches general pain and tremors after exposure to metallic mercury ” as well as irregular heartbeat it has been documented that “ the tremor in the hands can be so severe that the victim is unable to hold a glass of water without spilling its contents ” the primary risk factor for erethism is long term exposure to mercury vapors and gasses at high levels one group at risk for mercury poisoning is industrial workers and those exposed to high levels of mercury residing naturally in the environment erethism is not as serious an issue as it was back before acceptable working condition regulations were enforced preventing mercury levels from getting too high limits the amount available for inhalation there is a risk of mercury poisoning in the home in some cases exposure to mercury vapor may stem from cultural and religious reasons where mercury is sprinkled on the floor of a home or car burned in a candle or mixed with perfume due to widespread use and popular concern the risk of toxicity from dental amalgam has been exhaustively investigated to date no convincing evidence of toxicity has been found one treatment of mercury poisoning was to admit fresh air to the patient by having him go outside daily as much as possible stimulants such as ammonia have also been documented to help restore pulse to a normal rhythm for a more comprehensive reading of treatment see mercury poisoning treatment section
ergotism pron ˈɜːrɡətˌɪzəm ur gət iz əm is the effect of long term ergot poisoning traditionally due to the ingestion of the alkaloids produced by the claviceps purpurea fungus that infects rye and other cereals and more recently by the action of a number of ergoline based drugs it is also known as ergotoxicosis ergot poisoning and saint anthony s fire ergot poisoning is a proposed explanation of bewitchment
erondu – cymet syndrome is a syndrome caused by a translocation on the 21 st chromosome the genetic karyotype for people with this condition is 46 xy inv 21 q 11 2 q 22 1 findings in these patients include hypotension hypoxemia seizures and impairment of cognitive ability patients with this condition may have persistent left superior vena cava that drains into the left atrium as well as pulmonary arteriovenous malformations erondu – cymet syndrome was discovered in 2006 by ugochi erondu and tyler cymet
erosio interdigitalis blastomycetica is a skin condition caused by a candida albicans infection characterized by an oval shaped area of macerated white skin on the web between and extending onto the sides of the fingers
erosion corrosion also known as impingement damage is the combined effect of corrosion and erosion caused by rapid flowing turbulent water it is probably the second most common cause of copper tube failures behind type 1 pitting which is also known as cold water pitting of copper tube copper water tubescopper tubes have been used to distribute drinking water within buildings for many years and hundreds of miles are installed throughout europe every year the long life of copper when exposed to natural waters is a result of its thermodynamic stability its high resistance to reacting with the environment and the formation of insoluble corrosion products that insulate the metal from the environment the corrosion rate of copper in most drinkable waters is less than 2 5 µm year at this rate a 15 mm tube with a wall thickness of 0 7 mm would last for about 280 years in some soft waters the general corrosion rate may increase to 12 5 µm year but even at this rate it would take over 50 years to perforate the same tube
erotic asphyxiation or breath control play is the intentional restriction of oxygen to the brain for the purposes of sexual arousal this sexual practice is variously called asphyxiophilia autoerotic asphyxia hypoxyphilia the term autoerotic asphyxiation is used when the act is done by a person to themselves colloquially a person engaging in the activity is sometimes called a gasper the erotic interest in asphyxiation is classified as a paraphilia in the diagnostic and statistical manual of the american psychiatric association
erotomania is a type of delusional disorder where the affected person believes that another person is in love with him or her this belief is usually applied to someone with higher status or a famous person but can also be applied to a complete stranger erotomanic delusions often occur in patients with schizophrenia and other psychotic disorders but can also occur during a manic episode in the context of bipolar i disorder during an erotomanic delusion the patient believes that a secret admirer is declaring his or her affection for the patient often by special glances signals telepathy or messages through the media usually the patient then returns the perceived affection by means of letters phone calls gifts and visits to the unwitting recipient even though these advances are unexpected and often unwanted any denial of affection by the object of this delusional love is dismissed by the patient as a ploy to conceal the forbidden love from the rest of the world erotomania is also called de clérambault s syndrome after the french psychiatrist gaëtan gatian de clérambault 1872 – 1934 who published a comprehensive review paper on the subject les psychoses passionelles in 1921 the term erotomania is often mistakenly confused with obsessive love obsession with unrequited love or hypersexuality
erotophilia is a personality trait which assesses an individual s disposition to respond to sexual cues in either a positive or negative manner it is measured on a continuous scale ranging from erotophobia to erotophilia erotophobes tend to score higher on authoritarianism and need for achievement have more traditional sex roles experience more sex guilt and have more negative reactions to masturbation and homosexuality than erotophiles erotophilic individuals tend to masturbate and fantasize more frequently think about sex more often have sexual intercourse for the first time at an earlier age have more past sexual experiences and have a greater number of intercourse partners than erotophobic individuals erotophiles are also more likely to engage in breast self examinations schedule regular gynecological visits and engage in preventative behaviors regarding sexually transmitted diseases e g more frequent condom use
the error floor is a phenomenon encountered in modern iterated sparse graph based error correcting codes like ldpc codes and turbo codes when the bit error ratio ber is plotted for conventional codes like reed – solomon codes under algebraic decoding or for convolutional codes under viterbi decoding the ber steadily decreases in the form of a curve as the snr condition becomes better for ldpc codes and turbo codes there is a point after which the curve does not fall as quickly as before in other words there is a region in which performance flattens this region is called the error floor region the region just before the sudden drop in performance is called the waterfall region error floors are usually attributed to low weight codewords in the case of turbo codes and trapping sets or near codewords in the case of ldpc codes
eruptive hypomelanosis is a novel paraviral exanthem suspected to be related to viral infections most patients are young children aged two to ten most children develop prodromal symptoms similar to common cold or influenza small monomorphous and hypopigmented macules then erupt there could be systemic manifestations like pharyngitis or enlargement of lymph nodes most children with eruptive hypomelanosis develop no complications the epidemiology aetiology clinical manifestations complication infectivity and management of eruptive hypomelanosis leave much space to be investigated
eruptive pseudoangiomatosis is a cutaneous condition characterized by the sudden appearance of 2 to 4 mm blanchable red papules it can appear in children or adults the papules appear similar to hemangiomas hence the name viruses found in patients include echovirus 25 and 32 coxsackie b epstein barr virus and cytomegalovirus
eruptive vellus hair cysts or evhc are small lesions that occur most often in the chest wall abdomen and extremities often with a crusted surface evhc may occur randomly or it can be inherited as an autosomal dominant trait the condition affects males and females equally and sporadic cases usually appear at 4 – 18 years of age the cysts appear similar clinically to steatocystoma multiplex as well as acneiform eruptions and milia therapeutic techniques that are safe and effective are rare with incision and drainage being the primary form of treatment when sporadic regression does not occur
erysipelas ɛrᵻˈsɪpələs greek ἐρυσίπελας red skin also known as ignis sacer holy fire and st anthony s fire in some countries is an acute infection typically with a skin rash usually on any of the legs and toes face arms and fingers it is an infection of the upper dermis and superficial lymphatics usually caused by beta hemolytic group a streptococcus bacteria on scratches or otherwise infected areas erysipelas is more superficial than cellulitis and is typically more raised and demarcated
in humans erysipelothrix rhusiopathiae infections most commonly present in a mild cutaneous form known as erysipeloid or fish poisoning e rhusiopathiae can cause an indolent cellulitis more commonly in individuals who handle fish and raw meat it gains entry typically by abrasions in the hand bacteremia and endocarditis are uncommon but serious sequelae due to the rarity of reported human cases e rhusiopathiae infections are frequently misidentified at presentation
erysipeloid of rosenbach is a cutaneous condition most frequently characterized by a purplish marginated swelling on the hands
erythema from the greek erythros meaning red is redness of the skin or mucous membranes caused by hyperemia increased blood flow in superficial capillaries it occurs with any skin injury infection or inflammation examples of erythema not associated with pathology include nervous blushes
erythema ab igne eai also known as hot water bottle rash fire stains laptop thigh granny s tartan and toasted skin syndrome is a skin condition caused by long term exposure to heat infrared radiation prolonged thermal radiation exposure to the skin can lead to the development of reticulated erythema hyperpigmentation scaling and telangiectasias in the affected area some people may complain of mild itchiness and a burning sensation but often unless a change in pigmentation is seen it can go unnoticed
erythema anulare centrifugum eac also known as deep gyrate erythema erythema perstans palpable migrating erythema and superficial gyrate erythema is a descriptive term for a class of skin lesion presenting redness erythema in a ring form anulare that spreads from a center centrifugum it was first described by darier in 1916 many different terms have been used to classify these types of lesions and it is still controversial on what exactly defines eac some of the types include annular erythema deep and superficial erythema perstans erythema gyratum perstans erythema gyratum repens darier erythema deep gyrate erythema and erythema figuratum perstans
erythema chronicum migrans new latin literally chronic migrating redness refers to the rash often though not always seen in the early stage of lyme disease it can appear anywhere from one day to one month after a tick bite this rash does not represent an allergic reaction to the bite but rather an actual skin infection with the lyme bacteria borrelia burgdorferi sensu lato erythema migrans is the only manifestation of lyme disease in the united states that is sufficiently distinctive to allow clinical diagnosis in the absence of laboratory confirmation it is a pathognomonic sign a physician identified rash warrants an instant diagnosis of lyme disease and immediate treatment without further testing even by the strict criteria of the centers for disease control and prevention such target lesions bull s eye rashes are characteristic of borrelia infections and no other pathogens are known that cause this form of rash a similar condition called southern tick associated rash illness stari produces a similar rash pattern although it develops more quickly and is smaller the associated infectious agent has not been determined antibiotic treatment resolves the illness quickly this erythema is also sometimes called erythema migrans or em however a less common meaning of the term erythema migrans is a mucosal condition of the tongue also called geographic tongue
erythema dyschromicum perstans also known as ashy dermatosis and dermatosis cinecienta is a skin condition with age of onset almost always before 40 years old characterized by skin lesions that are usually symmetrical and generalized
erythema elevatum diutinum is a form of vasculitis it has been described as a paraneoplastic syndrome
erythema gyratum repens also known as gammel s disease is a figurate erythema that is rapidly moving and usually a marker of underlying cancer usually from the lung
bazin disease or erythema induratum is a panniculitis on the back of the calves it was formerly thought to be a reaction to the tuberculum bacillus it is now considered a panniculitis that is not associated with a single defined pathogen it occurs mainly in women but is very rare now
erythema marginatum is a type of erythema redness of the skin or mucous membranes involving pink rings on the torso and inner surfaces of the limbs which come and go for as long as several months it is found primarily on extensor surfaces an association with bradykinin has been proposed in the case of hereditary angioedema
erythema multiforme is a skin condition of unknown cause it is a type of erythema possibly mediated by deposition of immune complexes mostly igm bound complexes in the superficial microvasculature of the skin and oral mucous membrane that usually follows an infection or drug exposure it is an uncommon disorder with peak incidence in the second and third decades of life the disorder has various forms or presentations which its name reflects multiforme multiform from multi formis target lesions are a typical manifestation two types one mild to moderate and one severe are recognized erythema multiforme minor and erythema multiforme major
erythema multiforme major also known as erythema multiforme majus is a form of rash with skin loss or epidermal detachment the term erythema multiforme majus is sometimes used to imply a bullous blistering presentation according to some sources there are two conditions included on a spectrum of this same disease process stevens – johnson syndrome sjs toxic epidermal necrolysis ten which described by alan lyell and previously called lyell syndrome 5 in this view em major sjs and ten are considered a single condition distinguished by degree of epidermal detachment however a consensus classification separates erythema multiforme minor erythema multiforme major and sjs ten as three separate entities
erythema redness multiforme em is usually a reaction of the skin and mucous membranes that occurs suddenly it appears as a symmetrical rash and may include the mucous membrane lesions this means that the body is sensitive to something that causes the skin and mucous membranes to react the more common mild form is refer to as em minor it consists of a skin rash that involve no more than one mucosal surface the sudden onset will progress rapidly as symmetrical lesions with circular color changes in some or all of the lesions rash will spread towards center or trunk of the body evenly distributed bumps on the skin become classic iris or target lesions they have bright red borders and small white bumps in the center the cause of em appears to be a highly sensitive reaction that can be triggered by a variety of causes the causes can include bacterial viral or chemical products such as antibiotics specifically penicillins or cephalosporins this reaction is an allergic reaction and is in no way contagious erythema multiforme minus is sometimes divided into papular and vesiulobullous forms
erythema nodosum en is an inflammatory condition characterised by inflammation of the fat cells under the skin resulting in tender red nodules or lumps that are usually seen on both shins it can be caused by a variety of conditions and typically resolves spontaneously within 30 days it is common in young people between 12 – 20 years of age
erythema toxicum neonatorum also known as erythema toxicum urticaria neonatorum and toxic erythema of the newborn is a common rash in neonates it appears in up to half of newborns carried to term usually between day 2 – 5 after birth it does not occur outside the neonatal period erythema toxicum is characterized by blotchy red spots on the skin with overlying white or yellow papules or pustules these lesions may be few or numerous the eruption typically resolves within first two weeks of life and frequently individual lesions will appear and disappear within minutes or hours it is a benign condition thought to cause no discomfort to the baby
erythrasma is a skin disease that causes brown scaly skin patches it is caused by the gram positive bacterium corynebacterium minutissimum it is prevalent among diabetics and the obese and in warm climates it is worsened by wearing occlusive clothing
erythrocyanosis crurum is a skin condition a variant of acrocyanosis caused by chronic exposure to cold
erythrocyte rosetting or e rosetting is a phenomenon seen through a microscope where red blood cells erythrocytes are arranged around a central cell to form a cluster that looks like a flower the red blood cells surrounding the cell form the petal while the central cell forms the stigma of the flower shape this formation occurs due to an immunological reaction between an epitope on the central cells surface and a receptor or antibody on a red blood cell the presence of e rosetting can be used as a test for t cells although more modern tests such as immunohistochemistry are available may be caused by plasmodium in malaria
erythroderma also known as exfoliative dermatitis dermatitis exfoliativa is an inflammatory skin disease with erythema and scaling that affects nearly the entire cutaneous surface in icd 10 a distinction is made between exfoliative dermatitis at l 26 and erythroderma at l 53 9
erythroid dysplasia is a condition in which immature red blood cells erythroid cells in the bone marrow are abnormal in size shape organization and or number erythroid dysplasia may be caused by vitamin deficiency or chemotherapy or it may be a sign of refractory anemia which is a myelodysplastic syndrome also called erythrodysplasia
erythrokeratodermia variabilis also known as erythrokeratodermia figurata variabilis keratosis extremitatum progrediens keratosis palmoplantaris transgrediens et progrediens mendes da costa syndrome mendes da costa type erythrokeratodermia and progressive symmetric erythrokeratoderma is a rare autosomal dominant disorder that usually presents at birth or during the first year of life to date it is thought to be caused by mutations in genes encoding for connexin channels proteins in the epidermis leading to the misregulation of homeostasis in keratinocytes one type is characterized by generalized persistent brown hyperkeratosis with accentuated skin markings while a second type is localized with involvement that is limited in extent and characterized by sharply demarcated hyperkeratotic plaques it can be associated with gjb 3 and gjb 4 it was characterized in 1925
erythrokeratodermia with ataxia also known as giroux – barbeau syndrome is a condition characterized by erythematous hyperkeratotic plaques with fine white attached scales distributed almost symmetrically on the extremities
erythromelalgia formerly known as mitchell s disease after silas weir mitchell acromelalgia red neuralgia or erythermalgia is a rare vascular peripheral pain disorder in which blood vessels usually in the lower extremities or hands are episodically blocked frequently on and off daily then become hyperemic and inflamed there is severe burning pain in the small fiber sensory nerves and skin redness the attacks are periodic and are commonly triggered by heat pressure mild activity exertion insomnia or stress erythromelalgia may occur either as a primary or secondary disorder i e a disorder in and of itself or a symptom of another condition secondary erythromelalgia can result from small fiber peripheral neuropathy of any cause polycythemia vera essential thrombocytosis hypercholesterolemia mushroom or mercury poisoning and some autoimmune disorders primary erythromelalgia is caused by mutation of the voltage gated sodium channel α subunit gene scn 9 a in 2004 erythromelalgia became the first human disorder in which it has been possible to associate an ion channel mutation with chronic neuropathic pain when its pathophysiology was initially published in the journal of medical genetics conversely in december 2006 a university of cambridge team reported an scn 9 a mutation that resulted in a complete lack of pain sensation in a pakistani street performer and some of his family members he felt no pain walked on hot coals and stabbed himself to entertain crowds
erythromelanosis follicularis faciei et colli is an erythematous pigmentary disease involving the follicles characterized by a reddish brown sharply demarcated symmetrical discoloration involving the preauricular and maxillary regions
erythroplakia or erythroplasia is a clinical term to describe any erythematous red area on a mucous membrane that cannot be attributed to any other pathology the term erythroplasia was coined by louis queyrat to describe a precancerous red lesion of the penis this gave rise to the term erythoplasia of queyrat depending upon the context this term may refer specifically to carcinoma in situ of the glans penis or vulva appearing as a red patch or may be used as a synonym of erythroplasia on other mucous membrane or transitional sites it mainly effects the glans penis the head of the penis although uncommonly it may present on the mucous membranes of the larynx and rarely the mouth or the anus erythroplakia is analogous to the term leukoplakia which describes white patches together these are the 2 traditionally accepted types of premalignant lesion in the mouth when a lesion contains both red and white areas the term speckled leukoplakia or eyrthroleukoplakia is used although erythroplakia is much less common than leukoplakia erythroplakia carries a significantly higher risk of containing dysplasia or carcinoma in situ and of eventually transforming into invasive squamous cell carcinoma a type of oral cancer
erythroplasia of queyrat is a squamous cell carcinoma in situ of the glans penis head of the penis or inner prepuce foreskin in males and the vulvae in females it mainly occurs in uncircumcised males over the age of 40 erythroplasia of queyrat may also occur on the anal mucosa or the oral mucosa some sources state that this condition is synonymous with bowen s disease however generally speaking bowen s disease refers to carcinoma in situ of any location on the skin such as the lower leg like bowen s disease erythroplasia of queyrat is associated with human papillomavirus 16 and is a precursor for invasive squamous cell carcinoma it is named for french dermatologist louis queyrat 1856 1933 who was head of the dermatology service of l hôpital ricord a venereal hospital in paris now hôpital cochin
erythropoietic porphyria is a type of porphyria associated with erythropoietic cells in erythropoietic porphyrias the enzyme deficiency occurs in the red blood cells there are three types x linked sideroblastic anemia or x linked dominant erythropoietic protoporphyria associated with alas 2 aminolevulinic acid synthase has also been described x linked dominant erythropoietic protoporphyria xdepp is caused by a gain of function mutation in the alas 2 5 aminolevulinate synthase gene the very first enzyme in the heme biosynthetic pathway the mutation is caused by a frameshift mutation caused by one of two deletions in the alas 2 exon 11 either c 1706 1709 delagtg or c 1699 1700 delat this alters the 19 th and 20 th residues of the c terminal domain thereby altering the 2 ° structure of the enzyme the delat mutation only occurred in one family studied whereas the delagtg mutation occurred in several genetically distinct families the delagtg causes a loss of an a helix which is replaced by a ß sheet previously known mutations in the alas 2 resulted in a loss of function mutation causing x linked sideroblastic anemia erythropoietic protoporphyria epp has similar symptoms as x linked dominant erythropoietic protoporphyria but the mutation occurs as a loss of function in the fech ferrochelatase enzyme the very last enzyme in the pathway all individuals studied presented symptoms without mutations in the fech enzyme the patterns of inheritance led the researchers to conclude the mutation must come from an enzyme on the x chromosome with alas 2 being the most likely candidate x linked dominant erythropoietic protoporphyria is distinct from epp in that there is no overload of fe 2 ions additionally unlike the other condition the arises out of a mutation of the alas 2 gene there is no anemia xdepp is characterized by a buildup of protoporphyrin ix caused by in increased level of function in the alas 2 enzyme because there is a buildup of proporphyrin ix with no malfunction of the fech enzyme all the available fe 2 is used in the production of heme causing the fech enzyme to use zn 2 in its place causing a buildup of zinc protoporphyrin ix x linked dominant erythropoietic protoporphyria is a relatively mild version of porphyria with the predominate symptom being extreme photo sensitivity causing severe itching and burning of the skin due to the buildup of protoporphyrin ix one possible treatment was discovered when treating an individual with supplemental iron for a gastric ulcer levels of free protoporphyrin decreased significantly as there was iron available for the fech to produce heme levels of zn protoporphyrin however did not decrease
erythropoietic protoporphyria epp is a form of porphyria which varies in severity and can be very painful it arises from a deficiency in the enzyme ferrochelatase leading to abnormally high levels of protoporphyrin in the erythrocytes plasma skin and liver the severity varies significantly from individual to individual a clinically similar form of porphyria known as x linked dominant protoporphyria was identified in 2008
erythrotelangiectatic rosacea also known as erythematotelangiectatic rosacea and vascular rosacea is characterized by prominent history of prolonged over ten minutes flushing reaction to various stimuli such as emotional stress hot drinks alcohol spicy foods exercise cold or hot weather or hot baths and showers
esca is a grape disease of mature grapevines it is a type of grapevine trunk disease the fungi phaeoacremonium aleophilum phaeomoniella chlamydospora and fomitiporia mediterranea are associated with the disease
escape reflex a kind of escape response is a simple reflectory reaction in response to stimuli indicative of danger that initiates an escape motion of an animal escape reflexes control the seemingly chaotic motion of a cockroach running from under the foot when one tries to squash it in higher animals examples of escape reflex include the withdrawal reflex e g the withdrawal of a hand in response to a pain stimulus sensory receptors in the stimulated body part send signals to the spinal cord along a sensory neuron within the spine a reflex arc switches the signals straight back to the muscles of the arm effectors via an intermediate neuron interneuron and then a motor neuron the muscle contracts there often is an opposite response of the opposite limb because this occurs automatically and independently in the spinal cord not the brain the brain only becomes aware of the response after it has taken place escape reflex arcs have a high survival value enabling organisms to take rapid action to avoid potential danger various animals may have specialized escape reflex circuits
escape response escape reaction or escape behaviour is a possible reaction in response to stimuli indicative of danger in particular it initiates an escape motion of an animal in the cases of reflectory reactions the escape response may also be called escape reflex the term is also used in a more general setting avoiding of unpleasant or dangerous situations studying escape reactions has a number of practical applications fish breeding insect repellent design preventing aircraft bird collisions etc
an eschar ˈɛskɑːr greek eschara is a slough or piece of dead tissue that is cast off from the surface of the skin particularly after a burn injury but also seen in gangrene ulcer fungal infections necrotizing spider bite wounds spotted fevers and exposure to cutaneous anthrax the term eschar is not interchangeable with scab an eschar contains necrotic tissue whereas a scab is composed of dried blood and exudate black eschars are most commonly attributed to anthrax which may be contracted through herd animal exposure but can also be obtained from pasteurella multocida exposure in cats and rabbits a newly identified human rickettsial infection r parkeri rickettsiosis can be differentiated from rocky mountain spotted fever by the presence of an eschar at the site of inoculation eschar is sometimes called a black wound because the wound is covered with thick dry black necrotic tissue eschar may be allowed to slough off naturally or it may require surgical removal debridement to prevent infection especially in immunocompromised patients e g if a skin graft is to be conducted if eschar is on a limb it is important to assess peripheral pulses of the affected limb to make sure blood and lymphatic circulation is not compromised if circulation is compromised an escharotomy or surgical incision through the eschar may be indicated an escharotic is a substance that causes tissue to die and slough off examples include acids alkalis carbon dioxide metallic salts and sanguinarine as well as certain medicines like imiquimod escharotics known as black salves containing ingredients such as zinc chloride and sanguinarine containing bloodroot extracts were traditionally used in herbal medicine as topical treatments for localised skin cancers but often cause scarring and can potentially cause serious injury and disfigurement consequently escharotic salves are very strictly regulated in most western countries and while some prescription medicines are available with this effect unauthorized sales are illegal some prosecutions have been pursued over unlicensed sales of escharotic products such as cansema
the eschenmoser fragmentation first published in 1967 is the chemical reaction of α β epoxyketones 1 with aryl sulfonylhydrazines 2 to give alkynes 3 and carbonyl compounds 4 this reaction is named after the swiss chemist albert eschenmoser who devised it in collaboration with an industrial research group around günther ohloff in firmenich for the production of muscone and related macrocyclic musks hence the reaction is also known as eschenmoser – ohloff fragmentation in the same year i e 1967 masato tanabe et al of sri international published an article detailing the reaction and thus some also refer to it as the eschenmoser – tanabe fragmentation the eschenmoser fragmentation several examples exist in the literature and the reaction is also carried out on industrial scale
the eschenmoser sulfide contraction is an organic reaction first described by albert eschenmoser for the synthesis of 1 3 dicarbonyl compounds from a thioester the method requires a base and a tertiary phosphine the method is of some relevance to organic chemistry and has been notably applied in the vitamin b 12 total synthesis eschenmoser sulfur contraction svg a base abstracts the labile hydrogen atom in the thioester a sulfide anion is formed through an episulfide intermediate which is removed by the phosphine eschenmoser sulfur contraction mechanism
escherichia coli o 157 h 7 is a serotype of the bacterial species escherichia coli and is one of the shiga toxin – producing types of e coli it is a cause of disease typically foodborne illness of the colonic escherichiosis type through consumption of contaminated and raw food including raw milk infection with this type of pathogenic bacteria may lead to hemorrhagic diarrhea and to kidney failure these have been reported to cause the deaths of children younger than five years of age of elderly patients and of patients whose immunologies are otherwise compromised transmission is via the fecal – oral route and raw milk from goats sheep and cattle and most illness has been through distribution of contaminated raw leaf green vegetables undercooked meat and raw milk
the eschweiler – clarke reaction also called the eschweiler – clarke methylation is a chemical reaction whereby a primary or secondary amine is methylated using excess formic acid and formaldehyde reductive amination reactions such as this one will not produce quaternary ammonium salts but instead will stop at the tertiary amine stage it is named for the german chemist wilhelm eschweiler 1860 – 1936 and the british chemist hans thacher clarke 1887 1972 the eschweiler – clark reaction
esocid lymphosarcoma is a tumor found in northern pike and muskellunge in north america and europe it is described as an infectious disease of probable viral origin external signs of tumors include protruding growths on the flank fins and head that are several centimeters in diameter and have irregular surfaces tumors can also occur on internal organs including muscle kidney liver and heart the color of the tumor can be whitish gray red or pink the tumors are very soft and upon maturity can rupture and appear as dead tissue
esophageal atresia or oesophageal atresia is a congenital medical condition birth defect which affects the alimentary tract it causes the esophagus to end in a blind ended pouch rather than connecting normally to the stomach it comprises a variety of congenital anatomic defects that are caused by an abnormal embryological development of the esophagus it is characterized anatomically by a congenital obstruction of the esophagus with interruption of the continuity of the esophageal wall
esophageal cancer or oesophageal cancer is cancer arising from the esophagus — the food pipe that runs between the throat and the stomach symptoms often include difficulty in swallowing and weight loss other symptoms may include pain when swallowing a hoarse voice enlarged lymph nodes glands around the collarbone a dry cough and possibly coughing up or vomiting blood the two main sub types of the disease are esophageal squamous cell carcinoma often abbreviated to escc which is more common in the developing world and esophageal adenocarcinoma eac which is more common in the developed world a number of less common types also occur squamous cell carcinoma arises from the epithelial cells that line the esophagus adenocarcinoma arises from glandular cells present in the lower third of the esophagus often where they have already transformed to intestinal cell type a condition known as barrett s esophagus causes of the squamous cell type include tobacco alcohol very hot drinks poor diet and chewing betel nut the most common causes of the adenocarcinoma type are smoking tobacco obesity and acid reflux the disease is diagnosed by biopsy done by an endoscope a fiberoptic camera prevention includes stopping smoking and eating a healthy diet treatment is based on the cancer s stage and location together with the person s general condition and individual preferences small localized squamous cell cancers may be treated with surgery alone with the hope of a cure in most other cases chemotherapy with or without radiation therapy is used along with surgery larger tumors may have their growth slowed with chemotherapy and radiation therapy in the presence of extensive disease or if the affected person is not fit enough to undergo surgery palliative care is often recommended outcomes are related to the extent of the disease and other medical conditions but generally tend to be fairly poor as diagnosis is often late five year survival rates are around 13 to 18 as of 2012 esophageal cancer is the eighth most common cancer globally with 456 000 new cases during the year it caused about 400 000 deaths that year up from 345 000 in 1990 rates vary widely among countries with about half of all cases occurring in china it is around three times more common in men than in women
esophageal candidiasis is an opportunistic infection of the esophagus by candida albicans the disease usually occurs in patients in immunocompromised states including post chemotherapy and in aids however it can also occur in patients with no predisposing risk factors and is more likely to be asymptomatic in those patients it is also known as candidal esophagitis or monilial esophagitis
esophageal diseases can derive from congenital conditions or they can be acquired later in life many people experience a burning sensation in their chest occasionally caused by stomach acids refluxing into the esophagus normally called heartburn extended exposure to heartburn may erode the lining of the esophagus leading potentially to barrett s esophagus which is associated with an increased risk of adenocarcinoma most commonly found in the distal one third of the esophagus some people also experience a sensation known as globus esophagus where it feels as if a ball is lodged in the lower part of the esophagus the following are additional diseases and conditions that affect the esophagus acute esophageal necrosis achalasia barrett s esophagus chagas disease caustic injury to the esophagus esophageal atresia and tracheoesophageal fistula esophageal cancer esophageal varices esophageal web esophagitis gerd hiatus hernia killian – jamieson diverticulum mallory weiss syndrome neurogenic dysphagia schatzki s ring zenker s diverticulum boerhaave syndrome diffuse esophageal spasm esophageal dysphagia
an esophageal food bolus obstruction or steakhouse syndrome is a medical emergency caused by the obstruction of the esophagus by an ingested foreign body it is usually associated with diseases that narrow the lumen of the esophagus such as eosinophilic esophagitis schatzki rings peptic strictures webs or cancers of the esophagus rarely it can be seen in disorders of the movement of the esophagus such as nutcracker esophagus while some esophageal food boli can pass by themselves or with the assistance of medications some require the use of endoscopy to push the obstructing food into the stomach or remove it from the esophagus
esophageal intramucosal pseudodiverticulosis is a rare condition wherein the wall of the esophagus develops numerous small outpouchings pseudodiverticulae individuals with the condition typically develop difficulty swallowing the outpouchings represent the ducts of submucosal glands of the esophagus it typically affects individuals in their sixth and seventh decades of life while it is associated with certain chronic conditions particularly alcoholism diabetes and gastroesophageal reflux disease the cause of the condition is unknown treatment involves medications to treat concomitant conditions such as reflux such as proton pump inhibitors and esophageal spasm and dilation of strictures in the esophagus
an esophageal motility disorder is any medical disorder causing difficulty in swallowing regurgitation of food and a spasm type pain which can be brought on by an allergic reaction to certain foods the most prominent one is dysphagia it is a part of crest syndrome refers to the five main features calcinosis raynaud s phenomenon esophageal dysmotility sclerodactyly and telangiectasia
esophageal spasm or oesophageal spasm is a disorder of esophageal motility the esophagus is an organ in vertebrates which consists of a fibromuscular tube through which food passes aided by peristalsis contractions from the upper esophageal sphincter to the stomach through waves of co ordinated muscle contraction or peristalsis there are two types of esophageal spasm diffuse esophageal spasm des where there is unco ordinated esophageal contractions where several sections of the esophagus can contract at once nutcracker esophagus ne also known as hypertensive peristalsis where the contractions are co ordinated but with an excessive amplitude both conditions can be linked with gastroesophageal reflux disease when the co ordinated muscle contraction are irregular or uncoordinated this condition may be called diffuse esophageal spasm these spasms can prevent food from reaching the stomach where food gets stuck in the esophagus at other times the co ordinated muscle contraction is very powerful which is called nutcracker esophagus these contractions move food through the esophagus but can cause severe pain
an esophageal stent is a stent tube placed in the esophagus to keep a blocked area open so the patient can swallow soft food and liquids esophageal stents may be self expandable metallic stents or made of plastic or silicone and may be used in the treatment of esophageal cancer a 2007 study showed no difference in the quality of palliation between plastic and metal stents but a novel polyester mesh stent caused more complications especially migration as of 2009 covered self expanding metal stents were the only fda approved to be placed permanently occasionally these stents may be placed as part of a clinical trial or as off label use to repair esophageal leaks or fistulae they are placed using the guidance of fluoroscopy x ray and endoscopy usually they are left in for less than four weeks
a benign esophageal stricture or peptic stricture is a narrowing or tightening of the esophagus that causes swallowing difficulties
in medicine gastroenterology esophageal varices or oesophageal varices are extremely dilated sub mucosal veins in the lower third of the esophagus they are most often a consequence of portal hypertension commonly due to cirrhosis patients with esophageal varices have a strong tendency to develop bleeding esophageal varices are diagnosed with endoscopy
esophageal webs are thin membranes located in the middle or upper esophagus
esophagitis or oesophagitis is inflammation of the esophagus it may be acute or chronic acute esophagitis can be catarrhal or phlegmonous whereas chronic esophagitis may be hypertrophic or atrophic
esophoria is a condition characterised by inward deviation of the eye usually due to extra ocular muscle imbalance causes include refractive errors divergence insufficiency convergence excess this can be due to nerve muscle congenital or mechanical anomalies unlike esotropia fusion is possible and therefore diplopia is uncommon
esotropia is a form of strabismus in which one or both eyes turns inward the condition can be constantly present or occur intermittently and can give the affected individual a cross eyed appearance it is the opposite of exotropia esotropia is sometimes erroneously called “ lazy eye ” which describes the condition of amblyopia — a reduction in vision of one or both eyes that is not the result of any pathology of the eye and cannot be resolved by the use of corrective lenses amblyopia can however arise as a result of esotropia occurring in childhood in order to relieve symptoms of diplopia or double vision the child s brain will ignore or “ suppress ” the image from the esotropic eye which when allowed to continue untreated will lead to the development of amblyopia treatment options for esotropia include glasses to correct refractive errors see accommodative esotropia below the use of prisms and or orthoptic exercises and or eye muscle surgery the term is from greek eso meaning inward and trope meaning a turning
essential dermatitis is an idiopathic inflammation of the skin that does not fit the picture of other well defined conditions such as atopic or contact dermatitis and is a diagnosis of exclusion
essential thrombocytosis et also known as essential thrombocythemia essential thrombocythaemia primary thrombocytosis is a rare chronic blood disorder characterised by the overproduction of platelets by megakaryocytes in the bone marrow it may albeit rarely develop into acute myeloid leukaemia or myelofibrosis it is one of four myeloproliferative disorders disorders characterised by increased production of a particular line of blood cell
essential tremor et also referred to as benign tremor familial tremor or idiopathic tremor is the most common movement disorder its cause is unknown it typically involves a tremor of the arms hands or fingers but sometimes involving the head vocal cords or other body parts during voluntary movements such as eating and writing it is distinct from parkinson s disease — and often misdiagnosed as such — although some individuals have both conditions essential tremor is commonly described as an action tremor i e it intensifies when one tries to use the affected muscles or postural tremor i e present with sustained muscle tone rather than a resting tremor such as is seen in parkinson ’ s which is usually not included among its symptoms
the essex lopresti fracture is a fracture of the radial head with concomitant dislocation of the distal radio ulnar joint and disruption of the interosseous membrane the injury is named after peter essex lopresti who described it in 1951
ester pyrolysis in organic chemistry is a vacuum pyrolysis reaction converting esters containing a β hydrogen atom into the corresponding carboxylic acid and the alkene the reaction is an ei elimination examples are the synthesis of acrylic acid from ethyl acrylate at 590 ° c the synthesis of 1 4 pentadiene from 1 5 pentanediol diacetate at 575 ° c or the construction of a cyclobutene framework at 700 ° c an example of ester pyrolosis ethyl acrylate decomposes into acrylic acid and ethene ethylene gas at 590 ° c
esthesioneuroblastoma is a rare form of cancer involving the nasal cavity it can cause loss of vision and taste it is often considered synonymous with olfactory neuroblastoma and is believed to arise from the olfactory epithelium but the exact tissue of origin is not yet well characterized it is associated with trisomy 8 it was first characterized in 1924
an estrogen dependent condition disease disorder or syndrome is a medical condition that is in part or full dependent on or is sensitive to the presence of estrogenic activity in the body known estrogen dependent conditions include mastodynia breast pain tenderness breast fibroids mammoplasia macromastia breast hypertrophy gynecomastia breast cancer precocious puberty in girls melasma menorrhagia endometriosis endometrial hyperplasia adenomyosis uterine fibroids uterine cancers e g endometrial cancer ovarian cancer and hyperestrogenism in males such as in certain conditions like cirrhosis and klinefelter s syndrome such conditions may be treated with drugs with antiestrogen actions including selective estrogen receptor modulators serms such as tamoxifen and clomifene estrogen receptor antagonists such as fulvestrant aromatase inhibitors such as anastrozole and exemestane gonadotropin releasing hormone gnrh analogues such as leuprolide and cetrorelix and or other antigonadotropins such as danazol gestrinone megestrol acetate and medroxyprogesterone acetate
estrogen insensitivity syndrome eis or estrogen resistance is a form of congenital estrogen deficiency caused by a defective estrogen receptor er specifically erα thus estrogens cannot be recognized and initiate their biological action congenital estrogen deficiency can also be caused by a defect in the aromatase enzyme in humans the condition is very rare and only two cases have been described one male and one female
estuarine acidification is a decrease in the ph of coastal marine ecosystems specifically those of estuaries ph change in estuaries is more complicated than in the open ocean due to direct impacts from land run off and coastal current dynamics ocean acidification is the ongoing decrease in the ph of the earth s oceans caused by the absorption of carbon dioxide co 2 from the atmosphere 0 1 units over the last century the ocean absorbs 30 40 of all co 2 emitted to the atmosphere this increase in aqueous carbon dioxide causes a decline in the ph of the ocean surface as carbon dioxide combines with water it releases protons hydrogen ions based on the following equation co 2 h 2 o ↔ h 2 co 3 ↔ hco 3 h ↔ co 3 2 h
in the dungeons dragons fantasy role playing game the ethereal filcher is a bizarre aberration
ethmocephaly is a type of cephalic disorder caused by holoprosencephaly ethmocephaly is the least common facial anomaly it consists of a proboscis separating narrow set eyes with an absent nose and microphthalmia abnormal smallness of one or both eyes cebocephaly another facial anomaly is characterized by a small flattened nose with a single nostril situated below incomplete or underdeveloped closely set eyes the least severe in the spectrum of facial anomalies is the median cleft lip also called premaxillary agenesis although the causes of most cases of holoprosencephaly remain unknown some may be due to dominant or chromosome causes such chromosomal anomalies as trisomy 13 and trisomy 18 have been found in association with holoprosencephaly or other neural tube defects genetic counseling and genetic testing such as amniocentesis is usually offered during a pregnancy if holoprosencephaly is detected the recurrence risk depends on the underlying cause if no cause is identified and the fetal chromosomes are normal the chance to have another pregnancy affected with holoprosencephaly is about 6 there is no treatment for holoprosencephaly and the prognosis for individuals with the disorder is poor most of those who survive show no significant developmental gains for children who survive treatment is symptomatic it is possible that improved management of diabetic pregnancies may help prevent holoprosencephaly however there is no means of primary prevention
ethoxylation is a chemical reaction in which ethylene oxide adds to alcohols and phenols the process converts the group roh into r oc 2 h 4 noh where n ranges from 1 to as high as 10 such compounds are called alcohol ethoxylates alcohol ethoxlates are often converted to related species called ethoxysulfates alcohol ethoxylates and ethoxysulfates are surfactants used widely in cosmetic and other commercial products the process is of great industrial significance with more than 2 000 000 metric tons various ethoxylates produced worldwide 1994
ethylene glycol poisoning is poisoning caused by drinking ethylene glycol early symptoms include intoxication vomiting and abdominal pain later symptoms may include a decreased level of consciousness headache and seizures long term outcomes may include kidney failure and brain damage toxicity and death may occur even after drinking a small amount ethylene glycol is a colorless odorless sweet liquid commonly found in antifreeze it may be drank accidental or purposefully in an attempt to cause death when broken down by the body it results in glycolic acid and oxalic acid which cause most of the toxicity the diagnosis may be suspected when calcium oxalate crystals are seen in the urine or when acidosis or an increased osmol gap is present in the blood diagnosis may be confirmed by measuring ethylene glycol levels in the blood however many hospitals do not have the ability to perform this test early treatment increases the chance of a good outcome treatment consists of stabilizing the person followed by the use of an antidote the prefered antidote is fomepizole with ethanol used if this is not avaliable hemodialysis may also be used in those where there is organ damage or a high degree of acidosis other treatments may include sodium bicarbonate thiamine and magnesium more than 5000 cases of poisoning occur in the united states each year those affected are often adults and male deaths from ethylene glycol have been reported as early as 1930 an outbreak of deaths in 1937 due to a medication mixed in ethylene glycol resulted in the food drug and cosmetic act of 1938 in the united states which mandated evidence of safety before new medications could be sold antifreeze products sometimes have a substance to make it bitter added to discourage drinking by children and other animals but this has not been found to be effective
ethylmalonic encephalopathy ee is a rare autosomal recessive inborn error of metabolism patients affected with ee are typically identified shortly after birth with symptoms including diarrhea petechiae and seizures the genetic defect in ee is thought to involve an impairment in the degradation of sulfide intermediates in the body hydrogen sulfide then builds up to toxic levels ee was initially described in 1994 most cases of ee have been described in individuals of mediterranean or arabic origin
the euclidean shortest path problem is a problem in computational geometry given a set of polyhedral obstacles in a euclidean space and two points find the shortest path between the points that does not intersect any of the obstacles in two dimensions the problem can be solved in polynomial time in a model of computation allowing addition and comparisons of real numbers despite theoretical difficulties involving the numerical precision needed to perform such calculations these algorithms are based on two different principles either performing a shortest path algorithm such as dijkstra s algorithm on a visibility graph derived from the obstacles or in an approach called the continuous dijkstra method propagating a wavefront from one of the points until it meets the other in three and higher dimensions the problem is np hard in the general case but there exist efficient approximation algorithms that run in polynomial time based on the idea of finding a suitable sample of points on the obstacle edges and performing a visibility graph calculation using these sample points there are many results on computing shortest paths which stays on a polyhedral surface given two points s and t say on the surfaceof a convex polyhedron the problem is to compute a shortest path that never leaves the surface and connects s with t this is a generalization of the problem from 2 dimension but it is much easier than the 3 dimensional problem also there are variations of this problem where the obstacles are weighted i e one can go through an obstacle but it incursan extra cost to go through an obstacle the standard problem is the special case where the obstacles have infinite weight this istermed as the weighted region problem in the literature
eul yong ta hangul 을용타 hanja 乙容打 is a south korean internet phenomenon used to describe the incident when south korean footballer lee eul yong slapped chinese forward li yi in the back of his head in a match against china in december 2003 or to describe the slap itself the incident led to over 200 parodies in south korea eul yong ta derives its name from lee eul yong who was carded for slapping li yi in the head and ta 打 which means strike or blow in hanja the term would roughly translate as eul yong strike or eul yong smash in english
in number theory euler s totient function counts the positive integers up to a given integer n that are relatively prime to n it is written using the greek letter phi as φ n or ϕ n and may also be called euler s phi function it can be defined more formally as the number of integers k in the range 1 ≤ k ≤ n for which the greatest common divisor gcd n k 1 the integers k of this form are sometimes referred to as totatives of n for example the totatives of n 9 are the six numbers 1 2 4 5 7 and 8 they are all relatively prime to 9 but the other three numbers in this range 3 6 and 9 are not because gcd 9 3 gcd 9 6 3 and gcd 9 9 9 therefore φ 9 6 as another example φ 1 1 since for n 1 the only integer in the range from 1 to n is 1 itself and gcd 1 1 1 euler s totient function is a multiplicative function meaning that if two numbers m and n are relatively prime then φ mn φ m φ n this function gives the order of the multiplicative group of integers modulo n the group of units of the ring z nz it also plays a key role in the definition of the rsa encryption system
eumycetoma is a chronic granulomatous fungal disease of humans affecting mainly the limbs and sometimes the abdominal and chest walls or the head mycetoma pedis mycetoma of the foot the most common form of mycetoma is known widely as the madura foot the infection is endemic in africa india and the central and south americas
eurocurrency is deposits in banks that are located outside the borders of the country that issue the currency the deposit is denominated in for example a deposit denominated in japanese yen held in a brazilian bank is a eurocurrency deposit likewise a deposit denominated in us dollars held in a singapore bank is a eurocurrency deposit or more specifically or more clearly a eurodollar deposit eurocurrency is the currency of any country held on deposit in europe outside its home market used as a source of short or medium term finance especially in international trade because of easy convertibility eurocurrency does not have to involve either the euro currency or the eurozone today the eurocurrency and eurobond markets are active because they avoid domestic interest rate regulations reserve requirements and other barriers to the free flow of capital
eurodollars are time deposits denominated in u s dollars at banks outside the united states and thus are not under the jurisdiction of the federal reserve consequently such deposits are subject to much less regulation than similar deposits within the u s the term was originally coined for u s dollars in european banks but it expanded over the years to its present definition — a u s dollar denominated deposit in tokyo or beijing would be likewise deemed a eurodollar deposit there is no connection with the euro currency or the eurozone more generally the euro prefix can be used to indicate any currency held in a country where it is not the official currency for example euroyen or even euroeuro
the european public hearing on european conscience and crimes of totalitarian communism 20 years after was a european public hearing organised by the czech presidency of the european union in the european parliament on 18 march 2009 the hearing was described by the presidency as the third step towards the establishment of a european platform of memory and conscience to support the activities of institutions engaged in reconciling with totalitarian regimes in europe the hearing was hosted by the deputy prime minister for european affairs alexandr vondra and the permanent representative of the czech republic to the european union milena vicenová on behalf of the czech presidency of the council of the european union in cooperation with meps supporting the prague declaration the first session chaired by tunne kelam mep included speeches by pavel žáček director institute for the study of totalitarian regimes emmanuel crabit european commission directorate general of justice freedom and security emanuelis zingeris chairman international commission for the evaluation of the crimes of the nazi and soviet occupation regimes in lithuania marius oprea institute for the investigation of communist crimes in romania hans altendorf office of the federal commissioner for the stasi records vasil kadrinov hannah arendt center nicolas werth institute for contemporary history cnrs and camilla andersson institute for information on the crimes of communism the second session chaired by jana hybášková mep included speeches by alexandr vondra deputy prime minister for european affairs of the czech republic ján figeľ european commissioner for education alejo vidal quadras mep vice president of the european parliament jan zahradil mep lászló tökés mep and sandra kalniete former european commissioner the conclusions called for the establishment of the platform of european memory and conscience and supported the proclamation of the european day of remembrance for victims of stalinism and nazism the hearing was followed by a resolution of the european parliament on european conscience and totalitarianism of 2 april 2009
the europium anomaly is the phenomenon whereby the europium eu concentration in a mineral is either enriched or depleted relative to some standard commonly a chondrite or mid ocean ridge basalt morb in geochemistry a europium anomaly is said to be positive if the eu concentration in the mineral is enriched relative to the other rare earth elements rees and is said to be negative if eu is depleted relative to the other rees while all lanthanides form relatively large trivalent 3 ions eu and cerium ce have additional valences europium forms 2 ions and ce forms 4 ions leading to chemical reaction differences in how these ions can partition versus the 3 rees in the case of eu its reduced divalent 2 cations are similar in size and carry the same charge as ca 2 an ion found in plagioclase and other minerals while eu is an incompatible element in its trivalent form eu 3 in an oxidizing magma it is preferentially incorporated into plagioclase in its divalent form eu 2 in a reducing magma where it substitutes for calcium ca 2 enrichment or depletion is generally attributed to europium s tendency to be incorporated into plagioclase preferentially over other minerals if a magma crystallizes stable plagioclase most of the eu will be incorporated into this mineral causing a higher than expected concentration of eu in the mineral versus other ree in that mineral a positive anomaly the rest of the magma will then be relatively depleted in eu with a concentration of eu lower than expected versus the concentrations of other rees in that magma if the eu depleted magma is then separated from its plagioclase crystals and subsequently solidifies its chemical composition will display a negative eu anomaly because the eu is locked up in the plagioclase left in the magma chamber conversely if a magma accumulates plagioclase crystals before solidification its rock composition will display a relatively positive eu anomaly a well known example of the eu anomaly is seen on the moon ree analyses of the moon s light colored lunar highlands show a large positive eu anomaly due to the plagioclase rich anorthosite comprising the highlands the darker lunar mare consisting mainly of basalt shows a large negative eu anomaly this has led geologists to speculate as to the genetic relationship between the lunar highlands and mare it is possible that much of the moon s eu was incorporated into the earlier plagioclase rich highlands leaving the later basaltic mare strongly depleted in eu
eustrongylidosis is a parasitic disease that mainly affects wading birds worldwide however the parasite ’ s complex indirect life cycle involves other species such as aquatic worms and fish moreover this disease is zoonotic which means the parasite can transmit disease from animals to humans eustrongylidosis is named after the causative agent eustrongylides and typically occurs in eutrophicated waters where concentrations of nutrients and minerals are high enough to provide ideal conditions for the parasite to thrive and persist because eutrophication has become a common issue due to agricultural runoff and urban development cases of eustrongylidosis are becoming prevalent and hard to control eustrongylidosis can be diagnosed before or after death by observing behavior clinical signs and performing fecal flotations and necropsies methods to control eustrongylidosis include preventing eutrophication and providing hosts with uninfected food sources in aquaculture farms parasites are known to be indicators of environmental health and stability and should therefore be studied further to better understand the parasite ’ s life cycle and how it affects predator prey interactions and improve conservation efforts
the opisthobranchia represent one of the more prominent gastropod lineages that have undergone euthyneury
euthyroid sick syndrome ess sick euthyroid syndrome ses thyroid allostasis in critical illness tumours uremia and starvation tacitus non thyroidal illness syndrome ntis or low t 3 low t 4 syndrome is a state of adaptation or dysregulation of thyrotropic feedback control where the levels of t 3 and or t 4 are at unusual levels but the thyroid gland does not appear to be dysfunctional this condition is often seen in starvation critical illness or patients in intensive care unit the most common hormone pattern in sick euthyroid syndrome is a low total and unbound t 3 levels with normal t 4 and tsh levels
eutypella canker is a plant disease caused by the fungal pathogen eutypella parasitica this disease is capable of infecting many species of maple trees and produces a large distinguishable canker on the main trunk of the tree infection and spread of the disease is accomplished with the release of ascospores from perithecia therefore the best way to manage the eutypella canker is to remove trees that have been infected if infected it can decrease the quality of wood cut for lumber and can thus have a negative economic impact
in some programming languages eval is a function which evaluates a string as though it were an expression and returns a result in others it executes multiple lines of code as though they had been included instead of the line including the eval the input to eval is not necessarily a string it may be structured representation of code such as an abstract syntax tree like lisp forms or of special type such as code as in python the analog for a statement is exec which executes a string or code in other format as if it were a statement in some languages such as python both are present while in other languages only one of either eval or exec is eval and apply are instances of meta circular evaluators interpreters of a language that can be invoked within the language itself
an evaluation function also known as a heuristic evaluation function or static evaluation function is a function used by game playing programs to estimate the value or goodness of a position in the minimax and related algorithms the evaluation function is typically designed to prioritize speed over accuracy the function looks only at the current position and does not explore possible moves therefore static
evans syndrome is an autoimmune disease in which an individual s antibodies attack their own red blood cells and platelets both of these events may occur simultaneously or one may follow on from the other its overall pathology resembles a combination of autoimmune hemolytic anemia and immune thrombocytopenic purpura autoimmune hemolytic anemia is a condition in which the red blood cells that normally carry oxygen and carbon dioxide are destroyed by an autoimmune process immune thrombocytopenic purpura is a condition in which platelets are destroyed by an autoimmune process platelets are a component of blood that contribute to the formation of blood clots in the body to prevent bleeding the syndrome was first described in 1951 by r s evans and colleagues
in mathematics an evasive boolean function ƒ of n variables is a boolean function for which every decision tree algorithm has running time of exactly n consequently every decision tree algorithm that represents the function has at worst case a running time of n
the event driven messaging is a design pattern applied within the service orientation design paradigm in order to enable the service consumers which are interested in events that occur within the periphery of a service provider to get notifications about these events as and when they occur without resorting to the traditional inefficient polling based mechanism
event driven architecture eda also known as message driven architecture is a software architecture pattern promoting the production detection consumption of and reaction to events an event can be defined as a significant change in state for example when a consumer purchases a car the car s state changes from for sale to sold a car dealer s system architecture may treat this state change as an event whose occurrence can be made known to other applications within the architecture from a formal perspective what is produced published propagated detected or consumed is a typically asynchronous message called the event notification and not the event itself which is the state change that triggered the message emission events do not travel they just occur however the term event is often used metonymically to denote the notification message itself which may lead to some confusion this architectural pattern may be applied by the design and implementation of applications and systems which transmit events among loosely coupled software components and services an event driven system typically consists of event emitters or agents event consumers or sinks and event channels emitters have the responsibility to detect gather and transfer events an event emitter does not know the consumers of the event it does not even know if a consumer exists and in case it exists it does not know how the event is used or further processed sinks have the responsibility of applying a reaction as soon as an event is presented the reaction might or might not be completely provided by the sink itself for instance the sink might just have the responsibility to filter transform and forward the event to another component or it might provide a self contained reaction to such event event channels are conduits in which events are transmitted from event emitters to event consumers the knowledge of the correct distribution of events is exclusively present within the event channel the physical implementation of event channels can be based on traditional components such as message oriented middleware or point to point communication which might require a more appropriate transactional executive framework building applications and systems around an event driven architecture allows these applications and systems to be constructed in a manner that facilitates more responsiveness because event driven systems are by design more normalized to unpredictable and asynchronous environments event driven architecture can complement service oriented architecture soa because services can be activated by triggers fired on incoming events this paradigm is particularly useful whenever the sink does not provide any self contained executive soa 2 0 evolves the implications soa and eda architectures provide to a richer more robust level by leveraging previously unknown causal relationships to form a new event pattern this new business intelligence pattern triggers further autonomous human or automated processing that adds exponential value to the enterprise by injecting value added information into the recognized pattern which could not have been achieved previously
everyday aesthetics is a recent subfield of philosophical aesthetics focusing on everyday events settings and activities in which the faculty of sensibility is saliently at stake alexander baumgarten established aesthetics as a discipline and defined it as scientia cognitionis sensitivae the science of sensory knowledge in his foundational work aesthetica 1750 this field has been dedicated since then to the clarification of fine arts beauty and taste only marginally referring to the aesthetics in design crafts urban environments and social practice until the emergence of everyday aesthetics during the ‘ 90 s as other subfields like environmental aesthetics or the aesthetics of nature everyday aesthetics also attempts to countervail aesthetics almost exclusive focus on the philosophy of art
evolutionary biology is the subfield of biology that studies the evolutionary processes that produced the diversity of life on earth starting from a single origin of life these processes include the descent of species and the origin of new species the discipline emerged through what julian huxley called the modern evolutionary synthesis of the 1930 s of understanding from several previously unrelated fields of biological research including genetics ecology systematics and palaeontology current research has widened to cover the genetic architecture of adaptation molecular evolution and the different forces that contribute to evolution including not only natural selection but sexual selection genetic drift and biogeography the newer field of evolutionary developmental biology evo devo investigates how embryonic development is controlled thus creating a wider synthesis that integrates developmental biology with the fields covered by the earlier evolutionary synthesis
in computer science evolutionary computation is a subfield of artificial intelligence more particularly soft computing that can be defined by the type of algorithms it is concerned with these algorithms called evolutionary algorithms are based on adopting darwinian principles hence the name technically they belong to the family of trial and error problem solvers and can be considered global optimization methods with a metaheuristic or stochastic optimization character distinguished by the use of a population of candidate solutions rather than just iterating over one point in the search space the application of recombination and evolutionary strategies makes them less prone to get stuck in local optima than alternative methods evolutionary computation uses iterative progress such as growth or development in a population this population is then selected in a guided random search using parallel processing to achieve the desired end such processes are often inspired by biological mechanisms of evolution as evolution can produce highly optimised processes and networks it has many applications in computer science
evolutionary informatics is a subfield of informatics addressing the practice of information processing in and the engineering of information systems for the study of biological evolution as well as the study of information in evolutionary systems natural and artificial
evolutionary musicology is a subfield of biomusicology that grounds the psychological mechanisms of music perception and production in evolutionary theory it covers vocal communication in non human animal species theories of the evolution of human music and cross cultural human universals in musical ability and processing
an evolutionary radiation is an increase in taxonomic diversity or morphological disparity due to adaptive change or the opening of ecospace radiations may affect one clade or many and be rapid or gradual where they are rapid and driven by a single lineage s adaptation to their environment they are termed adaptive radiations caribbean anoline lizards are a particularly interesting example of an adaptive radiation
evolutionary suicide is an evolutionary phenomenon in which the process of adaptation causes the population to become extinct for example individuals might be selected to switch from eating mature plants to seedlings and thereby deplete their food plant s population selection on individuals can theoretically produce adaptations that threaten the survival of the population much of the research on evolutionary suicide has used the mathematical modeling technique adaptive dynamics in which genetic changes are studied together with population dynamics this allows the model to predict how population density will change as a given trait invades the population evolutionary suicide has also been referred to as darwinian extinction runaway selection to self extinction or evolutionary collapse the idea is similar in concept to the tragedy of the commons or the tendency of the rate of profit to fall many adaptations have apparently negative effects on population dynamics for example infanticide by male lions or the production of toxins by bacteria however empirically establishing that an extinction event was unambiguously caused by the process of adaptation is not a trivial task
ewing s sarcoma or ewing sarcoma ˈjuːɪŋ is a malignant small round blue cell tumor it is a rare disease in which cancer cells are found in the bone or in soft tissue the most common areas in which it occurs are the pelvis the femur the humerus the ribs and clavicle collar bone since a common genetic locus is responsible for a large percentage of ewing s sarcoma and primitive neuroectodermal tumors these are sometimes grouped together in a category known as the ewing family of tumors the diseases are however considered to be different peripheral primitive neuroectodermal tumours are generally not associated with bones while ewing sarcomas are most commonly related to bone ewing s sarcoma occurs most frequently in teenagers and young adults with a male female ratio of 1 6 1 although usually classified as a bone tumour ewing s sarcoma can have characteristics of both mesodermal and ectodermal origin making it difficult to classify james ewing 1866 – 1943 first described the tumour establishing that the disease was separate from lymphoma and other types of cancer known at that time
the exabit is a multiple of the unit bit for digital information or computer storage the prefix exa symbol e is defined in the international system of units si as a multiplier of 1018 1 quintillion short scale and therefore 1 exabit 1018 bits 1000000000000000000 bits 1000 petabits the exabit has the unit symbol ebit or eb the exabit is closely related to the exbibit a unit multiple derived from the binary prefix exbi of the same order of magnitude which is equal to 260 bits 1152921504606846976 bits or approximately 15 larger than the exabit
the exabyte is a multiple of the unit byte for digital information the prefix exa indicates multiplication by the sixth power of 1000 1018 in the international system of units si therefore one exabyte is one quintillion bytes short scale the symbol for the exabyte is eb 1 eb 10006 bytes 1018 bytes 1000000000000000000 b 1000 petabytes 1 millionterabytes 1 billiongigabytes a related unit the exbibyte using a binary prefix is equal to 10246 260 bytes about 15 larger
an exanthem or exanthema from greek ἐξάνθημα exánthēma a breaking out is a widespread rash usually occurring in children an exanthem can be caused by toxins drugs or microorganisms or can result from autoimmune disease it can be contrasted with an enanthem
exanthematic pustular psoriasis is a cutaneous condition characterized by an acute eruption of small pustules abruptly appearing and disappearing in a few days it usually follows an infection or may occur as a result of administration of specific medications
the exbibit is a multiple of the bit a unit of digital information storage prefixed by the standards based multiplier exbi symbol ei a binary prefix meaning 260 the unit symbol of the exbibit is eibit 1 exbibit 260 bits 1152921504606846976 bits 1024 pebibits the exbibit is closely related to the exabit the corresponding unit using the metric prefix exa which is 1018 bits 1000000000000000000 bits
the exbibyte is a multiple of the unit byte for digital information it is a member of the set of units with binary prefixes defined by the international electrotechnical commission iec its unit symbol is eib the prefix exbi symbol ei represents multiplication by 260 therefore 1 exbibyte 260 bytes 1152921504606846976 bytes 1024 pebibytes the exbibyte is closely related to the exabyte eb the corresponding unit in the decimal system of multiples which is defined as 1018 bytes 1000000000000000000 bytes it follows that one exbibyte 1 eib is approximately equal to 1 15 eb
exceptional circumstances are the conditions required to grant additional powers to a government or government leader so as to alleviate or mitigate unforeseen or unconventional hardship the term is most commonly used in australia where it has been applied in various contexts most recognisably in relation to special consideration policies for students and drought relief payments for farmers known as exceptional circumstances relief payments or ecrp
exceptionalism is the perception that a country society institution movement individual or time period is exceptional i e unusual or extraordinary in some way although the idea appears to have developed with respect to an era today the term is particularly applied to national or regional exceptionalism other uses are rarer in the present day
in microeconomics an excess demand function is a function expressing excess demand for a product — the excess of quantity demanded over quantity supplied — in terms of the product s price and possibly other determinants it is the product s demand function minus its supply function in a pure exchange economy the excess demand is the sum of all agents demands minus the sum of all agents initial endowments a product s excess supply function is the negative of the excess demand function — it is the product s supply function minus its demand function in most cases the first derivative of excess demand with respect to price is negative meaning that a higher price leads to lower excess demand the price of the product is said to be the equilibrium price if it is such that the value of the excess demand function is zero that is when the market is in equilibrium meaning that the quantity supplied equals the quantity demanded in this situation it is said that the market clears if the price is higher than the equilbrium price excess demand will normally be negative meaning that there is a surplus positive excess supply of the product and not all of it being offered to the marketplace is being sold if the price is lower than the equilbrium price excess demand will normally be positive meaning that there is a shortage walras law implies that for every price vector the price – weighted total excess demand is 0 whether or not the economy is in general equilibrium this implies that if there is excess demand for one commodity there must be excess supply for another commodity
excess ovarian androgen release syndrome also known as ovarian saha syndrome is a cutaneous condition usually seen in young women between the ages of 16 and 20
excessive daytime sleepiness eds is characterized by persistent sleepiness and often a general lack of energy even during the day after apparently adequate or even prolonged nighttime sleep eds can be considered as a broad condition encompassing several sleep disorders where increased sleep is a symptom or as a symptom of another underlying disorder like narcolepsy sleep apnea or a circadian rhythm disorder some persons with eds including those with hypersomnias like narcolepsy and idiopathic hypersomnia are compelled to nap repeatedly during the day fighting off increasingly strong urges to sleep during inappropriate times such as while driving while at work during a meal or in conversations as the compulsion to sleep intensifies the ability to complete tasks sharply diminishes often mimicking the appearance of intoxication during occasional unique and or stimulating circumstances a person with eds can sometimes remain animated awake and alert for brief or extended periods of time eds can affect the ability to function in family social occupational or other settings a proper diagnosis of the underlying cause and ultimately treatment of symptoms and or the underlying cause can help mitigate such complications
in physics the exchange interaction with an exchange energy and exchange term is a quantum mechanical effect that only occurs between identical particles despite sometimes being called an exchange force in analogy to classical force it is not a true force as it lacks a force carrier the effect is due to the wave function of indistinguishable particles being subject to exchange symmetry that is either remaining unchanged symmetric or changing its sign antisymmetric when two particles are exchanged both bosons and fermions can experience the exchange interaction for fermions it is sometimes called pauli repulsion and related to the pauli exclusion principle for bosons the exchange interaction takes the form of an effective attraction that causes identical particles to be found closer together as in bose – einstein condensation the exchange interaction alters the expectation value of the distance when the wave functions of two or more indistinguishable particles overlap it increases for fermions or decreases for bosons the expectation value of the distance between identical particles as compared to distinguishable particles among other consequences the exchange interaction is responsible for ferromagnetism and for the volume of matter it has no classical analogue exchange interaction effects were discovered independently by physicists werner heisenberg and paul dirac in 1926
excited delirium is a controversial proposed condition that manifests as a combination of delirium psychomotor agitation anxiety hallucinations speech disturbances disorientation violent and bizarre behaviour insensitivity to pain elevated body temperature and superhuman strength excited delirium is sometimes called excited delirium syndrome if it results in sudden death usually via cardiac or respiratory arrest an outcome that is sometimes associated with the use of physical control measures including police restraint
excoriated acne also known as picker s acne or acne excoriée des jeunes filles is a mild acne accompanied by extensive excoriations
excoriation disorder also known as dermatillomania skin picking disorder neurotic excoriation acne excoriee pathologic skin picking psp compulsive skin picking csp or psychogenic excoriation is a mental disorder characterized by the repeated urge to pick at one s own skin often to the extent that damage is caused research has suggested that the urge to pick is similar to a body focused repetitive behavior but others have argued that for some the condition is more akin to a substance abuse disorder the two main strategies for treating this condition are pharmacological and behavioral intervention
software execution patterns or execution models are software patterns that address issues related to lower level support of application execution including strategies for executing streams of tasks and for the definition of building blocks to support task synchronization as such execution pattern is an umbrella term for workflow patterns and or concurrency patterns to a certain extent also distributed design patterns belong to this class
in psychology and neuroscience executive dysfunction or executive function deficit is a disruption to the efficacy of the executive functions which is a group of cognitive processes that regulate control and manage other cognitive processes executive dysfunction can refer to both neurocognitive deficits and behavioural symptoms it is implicated in numerous psychopathologies and mental disorders as well as short term and long term changes in non clinical executive control executive dysfunction is not the same as dysexecutive syndrome a term coined by alan baddeley to describe a common pattern of dysfunction in executive functions such as deficiencies in planning abstract thinking flexibility and behavioural control this group of symptoms usually resulting from brain damage tend to occur together however the existence of dysexecutive syndrome is controversial
exencephaly is a type of cephalic disorder wherein the brain is located outside of the skull this condition is usually found in embryos as an early stage of anencephaly as an exencephalic pregnancy progresses the neural tissue gradually degenerates the prognosis for infants born with exencephaly is extremely poor it is rare to find an infant born with exencephaly as most cases that are not early stages of anencephaly are usually stillborn those infants who are born with the condition usually die within hours or minutes
exercise associated hyponatremia or eah is a fluid electrolyte disorder caused by a decrease in sodium levels hyponatremia during or up to 24 hours after prolonged physical activity this disorder can develop when marathon runners or endurance event athletes drink more fluid usually water or sports drinks than their kidneys can excrete this excess water can severely dilute the level of sodium in the blood needed for organs especially the brain to function properly the incidence of eah in athletes has increased in recent years especially in the united states as marathon races and endurance events have become more popular a recent study showed 13 of the boston 2002 marathon runners experienced eah most cases were mild eight deaths from eah have been documented since 1985
exercise induced asthma or e i a occurs when the airways narrow as a result of exercise the preferred term for this condition is exercise induced bronchoconstriction eib exercise does not cause asthma but is frequently an asthma trigger
exercise induced collapse eic is a genetic syndrome predominantly occurring in mixed breed dogs related to several retriever breeds as well as purebred labrador retrievers but also seen in chesapeake bay retrievers and curly coated retrievers boykin spaniels cocker spaniels german wire haired pointers old english sheepdogs bouvier des flanders pembroke welsh corgis and clumber spaniels verified 2015 by laboklin in the uk the syndrome was first positively identified by dna in boykin spaniels in 2010 it is believed before this many owners had misdiagnosed eic episodes as heat stroke affected dogs show signs of muscle weakness loss of coordination severe marked increase in body temperature and life threatening collapse when participating in strenuous exercise or activity affected dogs can tolerate mild to moderate exercise but just 5 to 20 minutes of strenuous activity or even extreme excitement such as that seen in field trials or hunt tests can induce weakness or collapse dogs affected with eic usually cannot continue with intense retriever training but can live normal lives as house pets as noted by the umn a few affected dogs have died during exercise or while resting immediately after an episode of exercise induced collapse so an affected dog s exercise should always be stopped at the first hint of incoordination or wobbliness eic is being observed with increasing frequency either from the genetics becoming more widespread or from previously misdiagnosed cases being correctly identified now that there is evidence in the form of a dna test dogs that have eic are prone to mild to severe collapse that can range from dragging of the hind legs to complete collapse most affected dogs have been from field trial breedings signs become apparent in young dogs as they enter heavy training which is usually between 5 months and 7 years of age as stated in the initial umn study in 2007 dogs of either sex can be affected dogs with this condition are always normal at rest and are usually described as being extremely fit prime athletic specimens of their breed nervous system cardiovascular and musculoskeletal examinations are unremarkable as is routine blood analysis at rest and during an episode of collapse through grants from the akc chf a patented dna test was developed by the university of mn ofa www offa org provides a public database for those dogs that are dna tested the umn vbs genetics lab is also investigating cases of atypical collapse and also border collie collapse where the dog is a carrier or clear of the disease on the dna test but continues to exhibit signs of the eic disease
exercise intolerance is a condition of inability or decreased ability to perform physical exercise at the expected level or duration of someone with a specific physical condition it also includes experiences of unusually severe post exercise pain fatigue nausea vomiting or other negative effects exercise intolerance is not a disease or syndrome in and of itself but a primary symptom of chronic diastolic heart failure since there are many possible specific reasons why exercise could be inhibited this is a rather slippery term for instance the patient may experience unusual breathlessness dyspnea muscle pain myalgia tachypnoea abnormally rapid breathing tachycardia having a heart rate that exceeds the normal range or increasing muscle weakness while exercising or may after exercise experience severe headache nausea dizziness occasional muscle cramps or extreme fatigue in most cases the specific reason that exercise is not tolerated is of considerable significance when trying to isolate the cause down to a specific disease dysfunctions involving the pulmonary cardiovascular or neuromuscular systems have been frequently found to be associated with exercise intolerance with behavioural causes also playing a part in it
exocrine cancer is a disease in which malignant cancer cells are found in the tissues of the pancreas also called pancreatic cancer
exocrine pancreatic insufficiency epi is the inability to properly digest food due to a lack of digestive enzymes made by the pancreas epi is found in humans afflicted with cystic fibrosis and shwachman diamond syndrome and is common in dogs epi is caused by a progressive loss of the pancreatic cells that make digestive enzymes loss of digestive enzymes leads to maldigestion and malabsorption of nutrients from normal digestive processes chronic pancreatitis is the most common cause of epi in humans and cats in dogs the most common cause is by pancreatic acinar atrophy arising as a result of genetic conditions a blocked pancreatic duct or prior infection
exonumia are numismatic items such as tokens medals or scrip other than coins and paper money this includes good for tokens badges counterstamped coins elongated coins encased coins souvenir medallions tags wooden nickels and other similar items it is related to numismatics concerned with coins which have been legal tender and many coin collectors are also exonumists besides the above strict definition others extend it to include non coins which may or may not be legal tenders such as cheques credit cards and similar paper these can also be considered notaphily or scripophily
exophoria is a form of heterophoria in which there is a tendency of the eyes to deviate outward during examination when the eyes are dissociated the visual axes will appear to diverge away from one another
exophthalmos also called exophthalmus exophthalmia proptosis or exorbitism is a bulging of the eye anteriorly out of the orbit exophthalmos can be either bilateral as is often seen in graves disease or unilateral as is often seen in an orbital tumor complete or partial dislocation from the orbit is also possible from trauma or swelling of surrounding tissue resulting from trauma in the case of graves disease the displacement of the eye is due to abnormal connective tissue deposition in the orbit and extraocular muscles which can be visualized by ct or mri if left untreated exophthalmos can cause the eyelids to fail to close during sleep leading to corneal dryness and damage another possible complication would be a form of redness or irritation called superior limbic keratoconjunctivitis where the area above the cornea becomes inflamed as a result of increased friction when blinking the process that is causing the displacement of the eye may also compress the optic nerve or ophthalmic artery leading to blindness
an exostosis plural exostoses is the formation of new bone on the surface of a bone exostoses can cause chronic pain ranging from mild to debilitatingly severe depending on the shape size and location of the lesion it is most commonly found in places like the ribs where small bone growths form but sometimes larger growths can grow on places like the ankles knees shoulders elbows and hips very rarely are they on the skull they normally form on the bones of joints and can grow upwards for example if an extra bone formed on the ankle it might grow up to the shin when used in the phrases cartilaginous exostosis or osteocartilaginous exostosis it is considered synonymous with osteochondroma some sources consider the terms to mean the same thing even without qualifiers but this interpretation is not universal
an exothermic reaction is a chemical reaction that releases energy by light or heat it is the opposite of an endothermic reaction expressed in a chemical equation reactants → products energy
exotic ungulate encephalopathy is a transmissible spongiform encephalopathy tse or prion disease identified in infected organs of zoo animals this subgroup of the tses in captive animals was identified in zoo animals in great britain including species of greater kudu nyala gemsbok the common eland arabian and scimitar oryx an ankole watusi cow and an american bison studies indicate that transmission likely occurred via the consumption of feed supplemented with meat and bone meal although some animals died after the british ban on ground offal in animal feed all animals died during the 1990 s with the last death occurring in 1998
exotropia is a form of strabismus where the eyes are deviated outward it is the opposite of esotropia people with exotropia often experience crossed diplopia intermittent exotropia is a fairly common condition sensory exotropia occurs in the presence of poor vision infantile exotropia sometimes called congenital exotropia is seen during the first year of life and is less common than essential exotropia which usually becomes apparent several years later the brain s ability to see three dimensional objects depends on proper alignment of the eyes when both eyes are properly aligned and aimed at the same target the visual portion of the brain fuses the forms into a single image when one eye turns inward outward upward or downward two different pictures are sent to the brain this causes loss of depth perception and binocular vision there have also been some reports of people that can control their afflicted eye the term is from greek exo meaning outward and trope meaning a turning
expandable water toys or grow in water toys often called grow monsters are novelty items made from a superabsorbent polymer they are toys that expand up to 500 of their original mass or volume after putting them into water for several days also it shrinks with saltwater they are made from polymers that can absorb and retain extremely large amounts of a liquid relative to their own mass
in decision theory and quantitative policy analysis the expected value of including uncertainty eviu is the expected difference in the value of a decision based on a probabilistic analysis versus a decision based on an analysis that ignores uncertainty
in decision theory the expected value of sample information evsi is the expected increase in utility that a decision maker could obtain from gaining access to a sample of additional observations before making a decision the additional information obtained from the sample may allow them to make a more informed and thus better decision thus resulting in an increase in expected utility evsi attempts to estimate what this improvement would be before seeing actual sample data hence evsi is a form of what is known as preposterior analysis
expenditure incidence is the effect of government expenditure upon the distribution of private incomes this is commonly contrasted with benefit incidence as an approach to planning and measuring the effect of a government spending programme a pioneering analysis of this was made by the economist richard musgrave in his major work the theory of public finance establishing the differential effect of expenditure in this way is difficult because the effect of differing policies upon taxation and overall expenditure must be normalised and it is hard to model and measure the flows of money which result an analysis will commonly be structured in three stages 1 definition of the government programmes or budgetary expenditures and the corresponding database of monetary values 2 determining the measures of income the size of economic unit such as the individual family or community the timescale of analysis such as annual or lifetime the well being and externalities which arise from the expenditure 3 the resulting effects upon income distribution as a result of the expenditure are then calculated these will typically be presented graphically as a lorenz curve or in the form of an index such as the gini coefficient
expiratory apnea is a voluntary condition performed by a patient during a doctor s examination by breathing out and then holding one s breath it gets easier for the doctor to perform an auscultation of the heart with a stethoscope
an explanandum a latin term is a sentence describing a phenomenon that is to be explained and the explanans is the sentences adduced as explanations of that phenomenon for example one person may pose an explanandum by asking why is there smoke and another may provide an explanans by responding because there is a fire in this example smoke is the explanandum and fire is the explanans
explanation modules used in expert systems is a function that enables the knowledge worker to understand why the information explained and concluded by the domain expert is viable while consulting the information provided by the expert system the explanation module elucidates why the expert system reached its conclusion explanation modules are mostly used in training seminars as audiences are interested in learning how problems in the expert system are solved
explanatory power is the ability of a hypothesis or theory to effectively explain the subject matter it pertains to the opposite of explanatory power is explanatory impotence in the past various criteria or measures for explanatory power have been proposed in particular one hypothesis theory or explanation can be said to have more explanatory power than another about the same subject matter if more facts or observations are accounted for if it changes more surprising facts into a matter of course following peirce if more details of causal relations are provided leading to a high accuracy and precision of the description if it offers greater predictive power i e if it offers more details about what we should expect to see and what we should not if it depends less on authorities and more on observations if it makes fewer assumptions if it is more falsifiable i e more testable by observation or experiment following popper recently david deutsch proposed that the correct hypothesis or theory the one that stands out among all possible explanations is that specific explanation that is hard to vary by this expression he intends to state that the correct theory i e the true explanation provides specific details which fit together so tightly that it is impossible to change any one detail without affecting the whole theory
exploding head syndrome ehs is a benign condition in which a person hears loud imagined noises such as a bomb exploding a gunshot or a cymbal crash or experiences an explosive feeling when falling asleep or waking up these noises have a sudden onset are typically brief in duration and are often jarring for the sufferer exploding head syndrome is classified as a parasomnia and a sleep related dissociative disorder by the 2005 international classification of sleep disorders and is an unusual type of auditory hallucination in that it occurs in people who are not fully awake neither the cause nor the mechanism of exploding head syndrome is known as of 2015 there had not been sufficient studies conducted to make conclusive statements about prevalence nor who tends to suffer ehs it was previously thought that ehs was a rare syndrome occurring primarily in older i e 50 years individuals females and those suffering from sleep paralysis however a study in 2015 has shown that ehs affects more younger people than thought reporting that nearly one in five interviewed college students had experienced ehs at least once statistics from the study did not show that ehs was more frequent in females but instead found that more than one third of those who had ehs also experienced isolated sleep paralysis furthermore the study found that some subjects experienced exploding head syndrome to such a degree that it significantly impacted their lives case reports of ehs have been published since at least 1876 which silas weir mitchell described as sensory discharges in a patient the phrase exploding head syndrome was coined in a 1920 report by the welsh physician and psychiatrist robert armstrong jones a detailed description of the syndrome was given by british neurologist john m s pearce in 1989
an explosion is a rapid increase in volume and release of energy in an extreme manner usually with the generation of high temperatures and the release of gases supersonic explosions created by high explosives are known as detonations and travel via supersonic shock waves subsonic explosions are created by low explosives through a slower burning process known as deflagration when caused by a man made device such as an exploding rocket or firework the audible component of an explosion is referred to as its report which can also be used as a verb e g the rocket reported loudly upon impact
an exponent is a phonological manifestation of a morphosyntactic property in non technical language it is the expression of one or more grammatical properties by sound there are several kinds of exponents identity affixation reduplication internal modification subtraction
in mathematics the exponential integral ei is a special function on the complex plane it is defined as one particular definite integral of the ratio between an exponential function and its argument
in photography exposure is the amount of light per unit area the image plane illuminance times the exposure time reaching a photographic film or electronic image sensor as determined by shutter speed lens aperture and scene luminance exposure is measured in lux seconds and can be computed from exposure value ev and scene luminance in a specified region in photographic jargon an exposure generally refers to a single shutter cycle for example a long exposure refers to a single protracted shutter cycle to capture enough low intensity light whereas a multiple exposure involves a series of relatively brief shutter cycles effectively layering a series of photographs in one image for the same film speed the accumulated photometric exposure hv should be similar in both cases
exposure latitude is the extent to which a light sensitive material can be overexposed or underexposed and still achieve an acceptable result this measure is used for digital and analogue processes i e optical microlithography or photography
expressive aphasia non fluent aphasia is characterized by the loss of the ability to produce language spoken or written a person with expressive aphasia will exhibit effortful speech speech may only include important content words and leave out insignificant words like the this is known as telegraphic speech the person may still be understood but sentences will not be grammatical in very severe forms of expressive aphasia a person may only speak using single word utterances it is one subset of a larger family of disorders known collectively as aphasia expressive aphasia differs from dysarthria which is typified by a patient s inability to properly move the muscles of the tongue and mouth to produce speech expressive aphasia also differs from apraxia of speech which is a motor disorder characterized by an inability to create and sequence motor plans for speech comprehension is typically only mildly to moderately impaired in expressive aphasia due to difficulty understanding complex grammar this contrasts with receptive aphasia which is distinguished by a patient s inability to comprehend language or speak with appropriately meaningful words expressive aphasia is also known as broca s aphasia in clinical neuropsychology and agrammatic aphasia in cognitive neuropsychology and is caused by acquired damage to the anterior regions of the brain including but not limited to the left posterior inferior frontal gyrus or inferior frontal operculum also described as broca s area brodmann area 44 and brodmann area 45 expressive aphasia is also a symptom of some migraine attacks
expressive language disorder is a communication disorder in which there are difficulties with verbal and written expression it is a specific language impairment characterized by an ability to use expressive spoken language that is markedly below the appropriate level for the mental age but with a language comprehension that is within normal limits there can be problems with vocabulary producing complex sentences and remembering words and there may or may not be abnormalities in articulation as well as present speech production very often someone will have difficulty remembering things this memory problem is only disturbing for speech non verbal or non linguistically based memory will be unimpaired an example of a child with expressive language disorder can be seen here expressive language disorder affects work and schooling in many ways it is usually treated by specific speech therapy and usually cannot be expected to go away on its own expressive language disorder can be further classified into two groups developmental expressive language disorder and acquired expressive language disorder developmental expressive language disorder currently has no known cause is first observed when a child is learning to talk is more common in boys than girls and is much more common than the acquired form of the disorder acquired expressive language disorder is caused by specific damage to the brain by a stroke traumatic brain injury or seizures care must be taken to distinguish expressive language disorder from other communication disorders sensory motor disturbances intellectual disability and or environmental deprivation see dsm iv tr criterion d these factors affect a person s speech and writing to certain predictable extents and with certain differences careful diagnosis is also important because atypical language development can be a secondary characteristic of other physical and developmental problems that may first manifest as language problems
extended female sexuality is where the female of a species mates when infertile in most species the female only engages in copulation when she is fertile however extended sexuality has been documented in old world primates pair bonded birds and some insects such as carrion beetles extended sexuality is most prominent in human females who exhibit no change in copulation rate across the ovarian cycle although this behaviour incurs costs to females such as energy and time many researchers have proposed reasons for its existence these hypotheses include the male assistance hypothesis which proposes that females gain non genetic benefits such as food and shelter in exchange for sexual access a sub hypothesis of this is hrdy s proposing extended female sexuality as an adaptive process aiming to creating paternity confusion in males alternative hypotheses classified as male driven claim that extended female sexuality occurs due to male adaptations resulting from an inability to detect fertility status in females or to dampen immune responses against sperm finally spuhler s hypothesis suggests that the behaviour may have arisen as an incidental effect of larger adrenal glands in humans
external bacterial infection is a condition found in fish
external compression headache is caused by any type of headwear this includes headwear that places pressure on the head — including tight hats helmets headbands headphones and goggles it is not known why some people are more sensitive than others to this type of pressure external compression headaches can affect anyone who uses headwear the headaches are more common among people who have migraines it is believed to affect about four percent of the population it is also referred to as swim goggle headache these headaches can be brought on by such innocuous sources as wearing a halter top presses against the neck earplugs presses against the jaw and inner ear or wearing even a tiny hair clip compresses the scalp there is no known preventative treatment except to avoid the offending trigger however once symptoms arise and the trigger is removed triptan type migraine treatment is effective
the external debt is the amount of debt a country owes to foreign or international creditors the debtors can be the government corporations or citizens of that country the estimated philippines foreign debt under the aquino administration in early 2016 was 70 us 70 billion external debt was aprox 70 billion in early 2016 the public debt is the total amount of debt a central government or country owes it is also known as national debt the debtors can be the government corporations or citizens of that country the estimated philippines public debt under the aquino administration in 2016 was 163 934 972 678 public debt was 163 934 972 678 in early 2016 public debt per person 1 515 28 population 109 805 464 public debt as gdp 45 8 total annual debt change 8 4
external inhibition is the observed decrease of the response of a conditioned reaction when an external distracting stimulus that was not part of the original conditioned response set is introduced this effect was first observed in pavlov ’ s classical conditioning studies where the dogs would salivate less conditioned response when presented with the sound of the tuning fork conditioned stimulus in the distracting context of a passing truck external stimulus external inhibition is important for its main principle in classical conditioning where a conditioned response may decrease in magnitude after the external stimulus is introduced this is especially advantageous for when trying to disassociate conditioned stimulus and responses a practical example is where students who become anxious conditioned response upon standing in front of the class to give a presentation conditioned stimulus may feel less anxiety if their friends were sitting in front of the student presenting external stimulus the positive association of speaking to friends may distract the student from associating speaking to the entire class with anxiety
externalizing disorders are mental disorders characterized by externalizing behaviors maladaptive behaviors directed toward an individual s environment which cause impairment or interference in life functioning in contrast to individuals with internalizing disorders who internalize keep inside their maladaptive emotions and cognitions such feelings and thoughts are externalized manifested outside in behavior in individuals with externalizing disorders externalizing disorders are often specifically referred to as disruptive behavior disorders attention deficit hyperactivity disorder oppositional defiant disorder and conduct disorder or conduct problems which occur in childhood externalizing disorders however are also manifested in adulthood for example alcohol and substance related disorders and antisocial personality disorder are adult externalizing disorders externalizing psychopathology is associated with antisocial behavior which is different from and often confused for asociality
extinction is a neurological disorder that impairs the ability to perceive multiple stimuli of the same type simultaneously extinction is usually caused by damage resulting in lesions on one side of the brain those who are affected by extinction have a lack of awareness in the contralesional side of space towards the left side space following a right lesion and a loss of exploratory search and other actions normally directed toward that side
the extinction cross is an optical phenomenon that is seen when trying to extinguish a laser beam or non planar white light using crossed polarizers ideally crossed 90 ° rotated polarizers block all light since light which is polarized along the polarization axis of the first polarizer is perpendicular to the polarization axis of the second when the beam is not perfectly collimated however a characteristic fringing pattern is produced
an extinction event also known as a mass extinction or biotic crisis is a widespread and rapid decrease in the biodiversity on earth such an event is identified by a sharp change in the diversity and abundance of multicellular organisms it occurs when the rate of extinction increases with respect to the rate of speciation because the majority of diversity and biomass on earth is microbial and thus difficult to measure recorded extinction events affect the easily observed biologically complex component of the biosphere rather than the total diversity and abundance of life extinction occurs at an uneven rate based on the fossil record the background rate of extinctions on earth is about two to five taxonomic families of marine animals every million years marine fossils are mostly used to measure extinction rates because of their superior fossil record and stratigraphic range compared to land organisms the great oxygenation event was probably the first major extinction event since the cambrian explosion five further major mass extinctions have significantly exceeded the background extinction rate the most recent and debatably best known the cretaceous – paleogene extinction event which occurred approximately 66 million years ago ma was a large scale mass extinction of animal and plant species in a geologically short period of time in addition to the five major mass extinctions there are numerous minor ones as well and the ongoing mass extinction caused by human activity is sometimes called the sixth extinction mass extinctions seem to be a mainly phanerozoic phenomenon with extinction rates low before large complex organisms arose estimates of the number of major mass extinctions in the last 540 million years range from as few as five to more than twenty these differences stem from the threshold chosen for describing an extinction event as major and the data chosen to measure past diversity
an extracapsular fracture is a bone fracture near a joint but still located outside the joint capsule examples of extracapsular fractures are intertrochanteric and subtrochanteric hip fractures
extramammary paget ’ s disease empd also extramammary paget disease is a rare slow growing usually noninvasive intraepithelial in the skin adenocarcinoma outside the mammary gland and includes paget s disease of the vulva and the extremely rare paget s disease of the penis
extranodal nk t cell lymphoma nasal type which was known as angiocentric lymphoma in the real classification and also as nasal type nk lymphoma nk t cell lymphoma and polymorphic malignant midline reticulosis is a cutaneous condition which in korea is reported to be the most common form of cutaneous lymphoma after mycosis fungoides extranodal nk t cell lymphoma is a type of lymphoma it is called extranodal to emphasize that the location is typically not in the lymph node and is sometimes further qualified as nasal type the nasal cavity nasopharynx and upper aerodigestive tract are often involved although extranasal presentations do occur skin gastrointestinal tract eye testis lung soft tissue there is a strong association with epstein – barr virus the nccn guidelines recommend either high dose radiotherapy alone for stage i without high risk features or concurrent chemoradiotherapy for stage i and ii with either of two regimens l asparaginase containing regimens have been used in advanced stage disease
extraordinary magnetoresistance emr is a geometrical magnetoresistance effect discovered in 2000 where the change in electrical resistance upon the application of a large magnetic field can be greater than 1 000 000 at room temperature orders of magnitude greater than other magnetoresistance effects such as gmr and cmr the effect occurs in semiconductor metal hybrid systems when a transverse magnetic field is applied without a magnetic field the system is in a low resistance state with most of the current flow directed through the metallic region upon the application of a large magnetic field the system switches to a state of much higher electrical resistance due to the hall angle approaching 90 ° with the current flow inside the metallic region dramatically reduced the effect is influenced greatly by the system geometry with an enhancement of over four orders of magnitude shown to be possible with an alternative branched geometry since the emr effect occurs at room temperature and does not rely on magnetic materials it has many possible benefits for applications including in the read heads of future hard disk drives
extraordinary optical transmission eot is the phenomenon of greatly enhanced transmission of light through a subwavelength aperture in an otherwise opaque metallic film which has been patterned with a regularly repeating periodic structure generally when light of a certain wavelength falls on a subwavelength aperture it is diffracted isotropically in all directions evenly with minimal far field transmission this is the understanding from classical aperture theory as described by bethe in eot however the regularly repeating structure enables much higher transmission efficiency to occur up to several orders of magnitude greater than that predicted by classical aperture theory it was first described in 1998 this phenomenon that was fully analyzed with a microscopic scattering model is partly attributed to the presence of surface plasmon resonances and constructive interference a surface plasmon sp is a collective excitation of the electrons at the junction between a conductor and an insulator and is one of a series of interactions between light and a metal surface called plasmonics currently there is experimental evidence of eot out of the optical range analytical approaches also predict eot on perforated plates with a perfect conductor model holes can somewhat emulate plasmons at other regions of the electromagnetic spectrum where they do not exist then the plasmonic contribution is a very particular peculiarity of the eot resonance and should not be taken as the main contribution to the phenomenon more recent work has shown a strong contribution from overlapping evanescent wave coupling which explains why surface plasmon resonance enhances the eot effect on both sides of a metallic film at optical frequencies but accounts for the terahertz range transmission simple analytical explanations of this phenomenon have been elaborated emphasizing the similarity between arrays of particles and arrays of holes and establishing that the phenomenon is dominated by diffraction
between the inner surface of the general layer of the fascia which lines the interior of the abdominal and pelvic cavities and the peritoneum there is a considerable amount of connective tissue termed the extraperitoneal fat or subperitoneal connective tissue
extrapulmonary restriction is a type of restrictive lung disease indicated by decreased alveolar ventilation with accompanying hypercapnia it is characterized as an inhibition to the drive to breathe or an ineffective restoration of the drive to breathe extrapulmonary restriction can be caused by central and peripheral nervous system dysfunctions over sedation or trauma such as a broken rib
extrapyramidal symptoms eps also known as extrapyramidal side effects epse are drug induced movement disorders that include acute and tardive symptoms these symptoms include dystonia continuous spasms and muscle contractions akathisia motor restlessness parkinsonism characteristic symptoms such as rigidity bradykinesia slowness of movement and tremor and tardive dyskinesia irregular jerky movements antipsychotics are often discontinued due to inefficacy and intolerable side effects such as extrapyramidal symptoms since it is difficult to measure extrapyramidal symptoms rating scales are commonly used to assess the severity of movement disorders the simpson angus scale sas barnes akathisia rating scale bars abnormal involuntary movement scale aims and extrapyramidal symptom rating scale esrs are rating scales frequently used for such assessment and are not weighted for diagnostic purposes
extraskeletal chondroma also known as chondroma of soft parts is a cutaneous condition a rare benign tumor of mature cartilage
extraterritorial income exclusion under the u s internal revenue code is the amount excluded from a taxpayer s gross income for certain transactions that generate foreign trading gross receipts in general foreign trading gross receipts include gross receipts from the sale exchange lease rental or other disposition of qualifying foreign trade property foreign trading gross receipts also include receipts from certain services provided in connection with such property as well as engineering and architectural services for construction projects outside the united states extraterritorial income is the gross income of the taxpayer attributable to foreign trading gross receipts the taxpayer reports all of its extraterritorial income on its tax return the taxpayer uses form 8873 to calculate its exclusion from income that is qualifying foreign trade income
extraterritorial jurisdiction etj is the legal ability of a government to exercise authority beyond its normal boundaries any authority can claim etj over any external territory they wish however for the claim to be effective in the external territory except by the exercise of force it must be agreed either with the legal authority in the external territory or with a legal authority which covers both territories when unqualified etj usually refers to such an agreed jurisdiction or it will be called something like claimed etj the phrase may also refer to a country s laws extending beyond its boundaries in the sense that they may authorise the courts of that country to enforce their jurisdiction against parties appearing before them in respect of things that they did outside that country this does not depend on the co operation of other countries since the affected people are within the relevant country or their case is being heard by a court of that country for example many countries have laws which give their criminal courts jurisdiction to try prosecutions for piracy or terrorism committed outside their national boundaries sometimes such laws only apply to nationals of that country and sometimes they may apply to anyone
extratropical cyclones sometimes called mid latitude cyclones or wave cyclones are low pressure areas which along with the anticyclones of high pressure areas drive the weather over much of the earth extratropical cyclones are capable of producing anything from cloudiness and mild showers to heavy gales thunderstorms blizzards and tornadoes these types of cyclones are defined as large scale synoptic low pressure weather systems that occur in the middle latitudes of the earth in contrast with tropical cyclones they produce rapid changes in temperature and dew point along broad lines about the center of the cyclone called weather fronts
extravasation is the leakage of intravenously iv infused potentially damaging medications into the extravascular tissue around the site of infusion the leakage can occur through brittle veins in the elderly through previous venipuncture access or through direct leakage from wrongly positioned venous access devices when the leakage is not of harmful consequence it is known as infiltration extravasation of medication during intravenous therapy is an adverse event related to therapy that depending on the medication amount of exposure and location can potentially cause serious injury and permanent harm such as tissue necrosis milder consequences of extravasation include irritation characterized by symptoms of pain and inflammation with the clinical signs of warmth erythema or tenderness
according to bratton and kacmar s article the dark side of impression management extreme careerism is the propensity to pursue career advancement power and prestige through any positive or negative non performance based activity that is deemed necessary these non performance based activities are activities in which an employee can easily manipulate the people whom he is trying to impress extreme careerism has become increasingly common in the business and organisational world in the 1990 s and 2000 s in the united states seventeen additional workdays have been added to the calendar since 1994
exudative hyponychial dermatitis is a nail toxicity common during chemotherapy for breast cancer especially if docetaxel is the chemotherapeutic regimen
eye neoplasms can affect all parts of the eye and can be a benign tumor or a malignant tumor cancer eye cancers can be primary starts within the eye or metastatic cancer spread to the eye from another organ the two most common cancers that spread to the eye from another organ are breast cancer and lung cancer other less common sites of origin include the prostate kidney thyroid skin colon and blood or bone marrow
eye strain also known as asthenopia is an eye condition that manifests itself through nonspecific symptoms such as fatigue pain in or around the eyes blurred vision headache and occasional double vision symptoms often occur after reading computer work or other close activities that involve tedious visual tasks when concentrating on a visually intense task such as continuously focusing on a book or computer monitor the ciliary muscle tightens this can cause the eyes to get irritated and uncomfortable giving the eyes a chance to focus on a distant object at least once an hour usually alleviates the problem a crt computer monitor with a low refresh rate 70 hz or a crt television can cause similar problems because the image has a visible flicker aging crts also often go slightly out of focus and this can cause eye strain lcds do not go out of focus but are also susceptible to flicker if the backlight for the lcd uses pwm for dimming this causes the backlight to turn on and off for shorter intervals as the display becomes dimmer creating noticeable flickering which causes eye fatigue a page or photograph with the same image twice slightly displaced from a printing mishap or a camera moving during the shot as in this image can cause eye strain by the brain misinterpreting the image fault as diplopia and trying in vain to adjust the sideways movements of the two eyeballs to fuse the two images into one the word is from greek asthen opia ασθεν ωπία
eyelid dermatitis is commonly related to atopic dermatitis or allergic contact dermatitis volatile substances tosylamide epoxy hardeners insect sprays and lemon peel oil may be implicated with many cases of eyelid contact dermatitis being caused by substances transferred by the hands to the eyelids
eyespot is an important fungal disease of wheat caused by the necrotrophic fungus tapesia yallundae syn pseudocercosporella herpotrichoides w type anamorph oculimacula yallundae and tapesia acuformis syn pseudocercosporella herpotrichoides r type anamorph oculimacula acuformis it is also called strawbreaker eyespot is more severe where wheat is grown continuously and when the weather is cool and moist treating crops against eyespot with fungicide costs millions to farmers and is complicated by the pathogen becoming resistant to the more commonly used fungicides severe cases of the disease can reduce yield by up to 40 it is most common in temperate regions such as north and south america europe australia new zealand and africa
in anatomy an eyestalk sometimes spelled as eye stalk or known as an ommatophore is a protrusion that extends the eye away from the body giving the eye a better field of vision it is a common feature in nature and frequently appears in fiction
eype mouth is a natural break in a line of sea cliffs on the jurassic coast world heritage site in west dorset on the south coast of england the small river eype drains into the sea at this point eype means a steep place in old english the village of eype divided into the settlements lower and higher eype lies just upstream of the rivermouth which is reached by a single narrow lane which runs down through lower eype to a shingle beach with car park the coast to the west of the rivermouth is a noted site for rare beetles two species found here are unknown elsewhere in britain sphaerius acaroides lives in mud and at plant roots at the edge of standing freshwater pools on the site this species is particularly noteworthy in that it is the only british representative of the suborder myxophaga the weevil sitona gemellatus occurs on the site being found at the roots of leguminous plants although this species has been recorded in similar habitat at sidmouth devon it has not been recorded from there recently other rare beetles found at this site include the tiger beetle cicindela germanica the ground beetle drypta dentata and the weevil baris analis
faces syndrome is a syndrome of unique facial features anorexia cachexia eye and skin anomalies
fg syndrome fgs also known as opitz – kaveggia syndrome is a rare genetic syndrome caused by one or more recessive genes located on the x chromosome and causing physical anomalies and developmental delays first reported by opitz and kaveggia in 1974 its major clinical features include intellectual disability hyperactivity hypotonia low muscle tone and a characteristic facial appearance including macrocephaly an abnormally large head
the fabella sign is displacement of the fabella that is seen in cases of synovial effusion and popliteal fossa masses the fabella is a sesamoid bone located inside the gastrocnemius lateral head tendon on the posterior side of the knee in about 25 of people it can thus serve as a surrogate radio opaque marker of the posterior border of the knee s synovium on a lateral radiograph of the knee an increase in the distance from the fabella to the femur or to the tibia can be suggestive of fluid or of a mass within the synovial fossa this is of particular use in radiographic detection of knee effusions as the cause for the effusion may obscure the subcutaneous planes on x ray that can also be used to determine presence of effusion or effusion size
fabry disease ˈfɑːbri also known as fabry s disease anderson fabry disease angiokeratoma corporis diffusum and alpha galactosidase a deficiency is a rare genetic lysosomal storage disease inherited in an x linked manner fabry disease can cause a wide range of systemic symptoms it is a form of sphingolipidosis as it involves dysfunctional metabolism of sphingolipids the disease is named after one of its discoverers johannes fabry june 1 1860 – june 29 1930
the facade pattern or façade pattern is a software design pattern commonly used with object oriented programming the name is by analogy to an architectural facade a facade is an object that provides a simplified interface to a larger body of code such as a class library a facade can make a software library easier to use understand and test since the facade has convenient methods for common tasks make the library more readable for the same reason reduce dependencies of outside code on the inner workings of a library since most code uses the facade thus allowing more flexibility in developing the system wrap a poorly designed collection of apis with a single well designed api the facade design pattern is often used when a system is very complex or difficult to understand because the system has a large number of interdependent classes or its source code is unavailable this pattern hides the complexities of the larger system and provides a simpler interface to the client it typically involves a single wrapper class which contains a set of members required by client these members access the system on behalf of the facade client and hide the implementation details
face validity is the extent to which a test is subjectively viewed as covering the concept it purports to measure it refers to the transparency or relevance of a test as it appears to test participants in other words a test can be said to have face validity if it looks like it is going to measure what it is supposed to measure for instance if a test is prepared to measure whether students can perform multiplication and the people to whom it is shown all agree that it looks like a good test of multiplication ability this demonstrates face validity of the test face validity is often contrasted with content validity and construct validity some people use the term face validity to refer only to the validity of a test to observers who are not expert in testing methodologies for instance if a test is designed to measure whether children are good spellers and parents are asked whether the test is a good test this measures the face validity of the test if an expert is asked instead some people would argue that this does not measure face validity this distinction seems too careful for most applications generally face validity means that the test looks like it will work as opposed to has been shown to work
facet cyst or postoperative synovial facet cysts is the cyst of lumbar intraspinal synovial joint and ganglion the cause of facet cysts is not well known
facet joint arthrosis is an intervertebral disc disorder the facet joints or zygapophyseal joints are synovial cartilage covered joints that limit the movement of the spine and preserve segmental stability in the event of hypertrophy of the vertebrae painful arthrosis can occur the lumbar facet arthrosis syndrome was described in a 1987 article by s m eisenstein and c r parry of witwatersrand university
facet syndrome is a syndrome in which the facet joints synovial diarthroses from c 2 to s 1 cause back pain
facial eczema fe is a disease that mainly affects ruminants such as cattle sheep deer goats and south american camelids alpaca llamas it is caused by the fungus pithomyces chartarum that under favorable conditions can rapidly disseminate in pastures the fungus requires warm humid weather with night time temperatures of over 13 ° c 55 ° f for several days and litter at the bottom of the sward pithomyces chartarum occurs worldwide but is a problem predominantly where farm animals are intensively grazed especially in new zealand the spores of the fungus release the mycotoxin sporidesmin in the gastrointestinal tract causing a blockage in the bile ducts that leads to injury of the liver bile chlorophyll and other waste products consequently build up in the bloodstream causing photo sensitivity of the skin especially that exposed to direct sunlight this in turn causes severe skin irritation that the animal attempts to relieve by rubbing its head against available objects resulting in peeling of the skin the large family of fungi that produce mycotoxins of which sporidesmin is one live mainly on ryegrasses and can cause significant problems in grazing animals sporidesmin can lower an animals immunity and affect total production in farm animals and when taken in larger quantities can result in death the clinical symptoms of fe are distressing restlessness frequent urination shaking persistent rubbing of the head against objects e g fences trees etc drooping and reddened ears swollen eyes and avoidance of sunlight by seeking shade exposed areas of skin develop weeping dermatitis and scabs that can become infected and attractive to blow fly causing myiasis
facial nerve paralysis is a common problem that involves the paralysis of any structures innervated by the facial nerve the pathway of the facial nerve is long and relatively convoluted and so there are a number of causes that may result in facial nerve paralysis the most common is bell s palsy an idiopathic disease that may only be diagnosed by exclusion
facial trauma also called maxillofacial trauma is any physical trauma to the face facial trauma can involve soft tissue injuries such as burns lacerations and bruises or fractures of the facial bones such as nasal fractures and fractures of the jaw as well as trauma such as eye injuries symptoms are specific to the type of injury for example fractures may involve pain swelling loss of function or changes in the shape of facial structures facial injuries have the potential to cause disfigurement and loss of function for example blindness or difficulty moving the jaw can result although it is seldom life threatening facial trauma can also be deadly because it can cause severe bleeding or interference with the airway thus a primary concern in treatment is ensuring that the airway is open and not threatened so that the patient can breathe depending on the type of facial injury treatment may include bandaging and suturing of open wounds administration of ice antibiotics and pain killers moving bones back into place and surgery when fractures are suspected radiography is used for diagnosis treatment may also be necessary for other injuries such as traumatic brain injury which commonly accompany severe facial trauma in developed countries the leading cause of facial trauma used to be motor vehicle accidents but this mechanism has been replaced by interpersonal violence however auto accidents still predominate as the cause in developing countries and are still a major cause elsewhere thus prevention efforts include awareness campaigns to educate the public about safety measures such as seat belts and motorcycle helmets and laws to prevent drunk and unsafe driving other causes of facial trauma include falls industrial accidents and sports injuries
facility management or facilities management or fm is a management discipline concerned with the integration of processes within an organization to maintain and develop agreed services which support and improve the effectiveness of its primary activities
facioscapulohumeral muscular dystrophy fshmd fshd or fsh — originally named landouzy dejerine — is a usually autosomal dominant inherited form of muscular dystrophy md that initially affects the skeletal muscles of the face facio scapula scapulo and upper arms humeral fshd is the third most common genetic disease of skeletal muscle orpha net lists the prevalence as 4 100 000 while a 2014 population based study in the netherlands reported a significantly higher prevalence of 12 in 100 000 symptoms may develop in early childhood and are usually noticeable in the teenage years with 95 of affected individuals manifesting disease by age 20 years a progressive skeletal muscle weakness usually develops in other areas of the body as well often the weakness is asymmetrical life expectancy can be threatened by respiratory insufficiency and up to 20 of affected individuals become severely disabled requiring use of a wheel chair or mobility scooter in a dutch study approximately 1 of patients required nocturnal or diurnal ventilatory support non muscular symptoms frequently associated with fshd include subclinical sensorineural hearing loss and retinal telangiectasia in more than 95 of known cases the disease is associated with contraction of the d 4 z 4 repeat in the 4 q 35 subtelomeric region of chromosome 4 seminal research published in august 2010 now shows the disease requires a second mechanism which for the first time provides for its underlying genetics the second mechanism is a toxic gain of function of the dux 4 gene which is the first time in genetic research that a dead gene has been found to wake up and cause disease building on the 2010 unified theory of fshd researchers in 2014 published the first proposed pathophysiology definition of the disease and four viable therapeutic targets for possible intervention points
factitial lymphedema also known as hysterical edema is a skin condition produced by wrapping an elastic bandage cord or shirt around an extremity and or holding the extremity in a dependent and immobile state
factitious dermatitis also known as dermatitis artefacta is a form of factitious disorder in which patients will intentionally feign symptoms and produce signs of disease in an attempt to assume the patient role it is also self inflicted skin damage most commonly from prolonged deliberate scratching but sometimes by means of sharp instruments or another agency
factitious diarrhea is a condition in which a person deliberately produces diarrhea most commonly by surreptitious laxative abuse these people tend to have persistent and unexplained watery diarrhea that is high in volume and frequency and despite extensive evaluation the cause may remain unknown many cases may mimic inflammatory bowel disease or malabsorption syndromes bowel movements are generally about 10 to 20 a day and may be especially associated with nocturnal movements factitious diarrhea is most often seen in men and sometimes women of high socioeconomic status and many are employed in the medical field melanosis coli is a frequent find in long standing factitious diarrhea it demonstrates hyperpigmentation of the colon with white lymph nodes showing through on colonoscopy an alternative means of diagnosis is by detecting pigment in macrophages of the lamina propria
a factitious disorder is a condition in which a person acts as if they have an illness by deliberately producing feigning or exaggerating symptoms factitious disorder imposed on another is a condition in which a person deliberately produces feigns or exaggerates the symptoms of someone in his or her care münchausen syndrome a severe form of factitious disorder was the first kind identified and was for a period the umbrella term for all such disorders people with this condition may produce symptoms by contaminating urine samples taking hallucinogens injecting themselves with fecal material to produce an abscess and other similar behaviour they might be motivated to perpetrate factitious disorders either as a patient or by proxy as a caregiver to gain any variety of benefits including attention nurturing sympathy and leniency that are seen as not obtainable any other way in contrast somatic symptom disorders though also diagnoses of exclusion are characterized by multiple somatic complaints that are not produced intentionally
factor i deficiency also known as fibrinogen deficiency is a rare inherited bleeding disorder related to fibrinogen function in the blood coagulation cascade it is typically subclassified into three distinct disorders afibrinogenemia hypofibrinogenemia or dysfibrinogenemia afibrinogenemia is defined as a lack of fibrinogen in the blood clinically 20 mg deciliter of plasma the frequency of this disorder is estimated at between 0 5 and 2 per million hypofibrinogenemia is defined as a partial deficiency of fibrinogen clinically 20 – 80 mg deciliter of plasma estimated frequency varies from 0 5 to 3 per million dysfibrinogenemia is defined as malfunctioning or non functioning fibrinogen in the blood albeit at normal concentrations 200 – 400 mg deciliter of plasma hypodysfibrinogenemia is a partial deficiency of fibrinogen that is also malfunctioning estimated frequency varies from 1 to 3 per million within the united states afibrinogenemia accounts for 24 of all inherited abnormalities of fibrinogen while hypofibrinogenemia and dysfibrinogenemia account for 38 each
factor v leiden thrombophilia is a genetic disorder of blood clotting factor v leiden is a variant mutated form of human factor v one of several substances that helps blood clot that causes an increase in blood clotting hypercoagulability with this mutation the anticoagulant protein secreted that stops factor v from causing inappropriate clotting is inhibited leading to an increased tendency to form dangerous abnormal blood clots factor v leiden is the most common hereditary hypercoagulability prone to clotting disorder amongst ethnic europeans it is named after the dutch city leiden where it was first identified in 1994 by prof r bertina et al
factor xiii deficiency occurs exceedingly rarely causing a severe bleeding tendency the incidence is one in a million to one in five million people with higher incidence in areas with consanguineous marriage such as iran that has the highest global incidence of the disorder most are due to mutations in the a subunit gene located on chromosome 6 p 25 p 24 this mutation is inherited in an autosomal recessive fashion deficiency of factor xiii leads to defective cross linking of fibrin and vulnerability to late re bleeds when the primary hemostatic plug is overwhelmed bleeding tendencies similar to hemophiliacs develop such as hemarthroses and deep tissue bleeding as factor xiii is composed of two subunit protein a and b for which the genes are located on different chromosomes administration of recombinant a subunit improves clot stability and is becoming a therapeutic option for patients with this condition
the aging of natural and artificial polymeric materials is a natural phenomenon in metals glass minerals and other inorganic materials the main environmental parameters influencing the degradation of polymeric materials is daylight combined with the effects of temperature moisture and oxygen these act as the main parameters of stress for outdoor weathering
in object oriented programming oop a factory is an object for creating other objects – formally a factory is a function or method that returns objects of a varying prototype or class from some method call which is assumed to be new more broadly a subroutine that returns a new object may be referred to as a factory as in factory method or factory function this is a basic concept in oop and forms the basis for a number of related software design patterns
in class based programming the factory method pattern is a creational pattern that uses factory methods to deal with the problem of creating objects without having to specify the exact class of the object that will be created this is done by creating objects by calling a factory method — either specified in an interface and implemented by child classes or implemented in a base class and optionally overridden by derived classes — rather than by calling a constructor
factory seconds also known as factory rejects or simply seconds are retail items which through minor fault of manufacture are sold to the public for a reduced rate rather than being discarded such goods are often resold at this lower rate after failing the factory s quality inspection being returned to the manufacturer s factory by the original retailer or less frequently being returned to the retailer or wholesaler by the customer the amount of damage or fault in the manufacture which may constitute an item being resold as a second varies widely in clothing for example it may simply refer to a single pulled thread or mis sewn seam whereas in a set of items such as crockery it may mean there is one piece missing from the set generally an item listed as a factory second will have failed quality inspection for cosmetic rather than functional reasons such items are often heavily discounted but may not have as all encompassing a warranty or guarantee as a full quality item for example the product may be non returnable discount stores often rely on the sale of factory seconds as a major part of their trade
in audio engineering a fade is a gradual increase or decrease in the level of an audio signal the term can also be used for film cinematography or theatre lighting in much the same way see fade filmmaking and fade lighting a recorded song may be gradually reduced to silence at its end fade out or may gradually increase from silence at the beginning fade in fading out can serve as a recording solution for pieces of music that contain no obvious ending both fades and cross fades are very valuable since they allow the engineer to quickly and easily make sure that the beginning and the end of any audio region is smooth in order to not have any prominent glitches it is necessary that there is a clear section of silence prior to the audio fade ins and out can also be used to change the characteristics of a sound for example a fade in is used to soften the attack especially in vocals where very plosive ‘ b ’ ‘ d ’ and ‘ p ’ sounds can occur it can also be used to soften up the attack of the drum and or percussion instruments a cross fade can be manipulated through its rates and coefficients in order to create different styles of fading almost every fade is different this means that the fade parameters must be adjusted according to the individual needs of the mix though relatively rare songs can fade out then fade back in some examples of this are helter skelter and strawberry fields forever by the beatles suspicious minds by elvis presley rambling on by procol harum some girls are bigger than others by the smiths thank you by led zeppelin it s only money pt 2 by argent and future by paramore
in stage lighting a fade is a gradual increase or decrease of the intensity of light projected onto the stage the term fade in refers to gradually changing the lighting level from complete darkness to a predetermined lighting level a fade out also known as fade to black refers to gradually decreasing the intensity of light until none is shining on the stage a crossfade is when lighting levels are gradually altered from one setting to another a fade in is sometimes called a build and where this terminology is used a fade is understood to be a fade out increasing lighting intensities that are not black is referred to as a fade up similarly decreasing lighting intensities to a level above black is referred to as a fade down cross fades are accomplished by executing fade ups and or fade downs in nearly all theatrical lighting designs multiple lighting instruments are used to illuminate the stage at any one time a cue refers to the recorded state of illumination for the entire stage at that time the intensity of the lighting instruments are often altered with a single crossfade altering the lighting state of the stage the lighting instruments are altered from a dimmer board or lighting control panel operated by a lighting technician the dimmer board now referred to as the lighting console especially with newer digital control systems like dmx uses a serial data stream to control multiple groups called universes of 512 dmx addresses to control compatible fixtures including dimmers via different methods leading to a single twisted pair of wires connected to the fixtures dmx consoles are largely computerized thus allowing digital process control from multiple input devices and synchronization via midi smpte etc the terms fade in fade out and fade to black were borrowed by hollywood and are used in the formal structure of screenplays
the fading affect bias more commonly known as fab is a psychological phenomenon in which information regarding negative emotions tends to be forgotten more quickly than that associated with pleasant emotions although there have been some contradictory findings regarding the presence of fab it has been largely found to be real
idiopathic basal ganglia calcification also known as fahr disease is a rare genetically dominant inherited neurological disorder characterized by abnormal deposits of calcium in areas of the brain that control movement through the use of ct scans calcifications are seen primarily in the basal ganglia and in other areas such as the cerebral cortex
failed back syndrome or post laminectomy syndrome is a condition characterized by persistent pain following back surgeries failed back syndrome fbs also called failed back surgery syndrome fbss refers to chronic back and or leg pain that occurs after back spinal surgery usually after laminectomy it is characterized as a chronic pain syndrome multiple factors can contribute to the onset or development of fbs contributing factors include but are not limited to residual or recurrent spinal disc herniation persistent post operative pressure on a spinal nerve altered joint mobility joint hypermobility with instability scar tissue fibrosis depression anxiety sleeplessness and spinal muscular deconditioning an individual may be predisposed to the development of fbs due to systemic disorders such as diabetes autoimmune disease and peripheral blood vessels vascular disease common symptoms associated with fbs include diffuse dull and aching pain involving the back and or legs abnormal sensibility may include sharp pricking and stabbing pain in the extremities the term post laminectomy syndrome is used by some doctors to indicate the same condition as failed back syndrome the treatments of post laminectomy syndrome include physical therapy low force specific chiropractic care microcurrent electrical neuromuscular stimulator minor nerve blocks transcutaneous electrical nerve stimulation tens behavioral medicine non steroidal anti inflammatory nsaid medications membrane stabilizers antidepressants spinal cord stimulation and intrathecal morphine pump use of epidural steroid injections may be minimally helpful in some cases the targeted anatomic use of a potent anti inflammatory anti tnf therapeutics is being investigated the number of spinal surgeries varies around the world the united states and the netherlands report the highest number of spinal surgeries while the united kingdom and sweden report the fewest recently there have been calls for more aggressive surgical treatment in europe see infra success rates of spinal surgery vary for many reasons
fair division is the problem of dividing a set of goods or resources between several people who have an entitlement to them such that each person receives his her due share this problem arises in various real world settings auctions divorce settlements electronic spectrum and frequency allocation airport traffic management or exploitation of earth observation satellites this is an active research area in mathematics economics especially social choice theory game theory dispute resolution and more the central tenet of fair division is that such a division should be performed by the players themselves maybe using a mediator but certainly not an arbiter as only the players really know how they value the goods there are many different kinds of fair division problems depending on the nature of goods to divide the criteria for fairness the nature of the players and their preferences and other criteria for evaluating the quality of the division the mathematical fair division problem is an idealization of those real life problems the theory of fair division provides explicit criteria for various different types of fairness its aim is to provide procedures algorithms to achieve a fair division or prove their impossibility and study the properties of such divisions both in theory and in real life
a fall line or fall zone is the geomorphologic break that demarcates the border between an upland region of relatively hard crystalline basement rock and a coastal plain of softer sedimentary rock a fall line is typically prominent when crossed by a river for there will often be rapids or waterfalls many times a fall line will recede upstream as the river cuts out the uphill dense material often forming “ c ” shaped waterfalls because of these features riverboats typically cannot travel any farther inland without portaging unless locks are built there on the other hand the rapid change in elevation of the water and the resulting energy release makes the fall line a good location for water mills grist mills and sawmills because of the need for a river port leading to the ocean and a ready supply of water power settlements often develop where rivers cross a fall line
falling out is a culture bound syndrome primarily reported in the southern united states and the caribbean it is described as a constricted consciousness as a psychological response to anxiety and specific stressors sudden collapse characterizes episodes of falling out whether without warning or preceded by dizziness and a spinning sensation the individual suffering from symptoms of falling out can usually hear and understand what is going on around them falling out is not treated as an illness unless it becomes disabling it is often seen as a normal response to stressful situations funerals or when a person receives shocking information
falling is the second leading cause of accidental death worldwide and is a major cause of personal injury especially for the elderly falls in older adults are an important class of preventable injuries builders electricians miners and painters are occupations with high rates of fall injuries about 155 million new cases of a significant fall occurred in 2013 these unintentional falls resulted in 556 000 deaths up from 341 000 deaths in 1990
the falling cat problem is a problem that consists of explaining the underlying physics behind the observation of the cat righting reflex that is how a free falling body cat can change its orientation such that it is able to right itself as it falls to land on its feet irrespective of its initial orientation and without violating the law of conservation of angular momentum although amusing and trivial to pose the solution of the problem is not as straightforward as its statement would suggest the apparent contradiction with the law of conservation of angular momentum is resolved because the cat is not a rigid body but instead is permitted to change its shape during the fall owing to the cat s flexible backbone and non functional collar bone the behavior of the cat is thus typical of the mechanics of deformable bodies
a falling scream is a sound effect used mostly in animation and live action movies when an object falls down with great speed it is generally described as a long continuous whistle from the dropping point which gets louder in mid flight then dies out at the point of impact it often demonstrates the doppler effect
primary fallopian tube cancer pftc often just tubal cancer is a malignant neoplasm that originates from the fallopian tube
fallopian tube obstruction is a major cause of female infertility blocked fallopian tubes are unable to let the ovum and the sperm converge thus making fertilization impossible fallopian tubes are also known as oviducts uterine tubes and salpinges singular salpinx
falls in older adults are a significant cause of morbidity and mortality and are an important class of preventable injuries the cause of falling in old age is often multifactorial and may require a multidisciplinary approach both to treat any injuries sustained and to prevent future falls falls include dropping from a standing position or from exposed positions such as those on ladders or stepladders the severity of injury is generally related to the height of the fall the state of the ground surface onto which the victim falls is also important harder surfaces causing more severe injury falls can be prevented by ensuring that carpets are tacked down that objects like electric cords are not in one s path that hearing and vision are optimized dizziness is minimized alcohol intake is moderated and that shoes have low heels or rubber soles
false brinelling is damage caused by fretting with or without corrosion that causes imprints that look similar to brinelling but are caused by a different mechanism brinell damage is characterized by permanent material deformation without loss of material and occurs during one load event whereas false brinelling is characterized by material wear or removal and occurs over an extended time from vibration and light loads the basic cause of false brinelling is that the design of the bearing does not have a method for redistribution of lubricant without large rotational movement of all bearing surfaces in the raceway lubricant is pushed out of a loaded region during small oscillatory movements and vibration where the bearings surfaces repeatedly do not move very far without lubricant wear is increased when the small oscillatory movements occur again it is possible for the resulting wear debris to oxidize and form an abrasive compound which further accelerates wear
false diffusion is a type of error observed when the upwind scheme is used to approximate the convection term in convection – diffusion equations the more accurate central difference scheme can be used for the convection term but for grids with cell peclet number more than 2 the central difference scheme is unstable and the simpler upwind scheme is often used the resulting error from the upwind differencing scheme has a diffusion like appearance in two or three dimensional co ordinate systems and is referred as false diffusion false diffusion errors in numerical solutions of convection diffusion problems in two and three dimensions arise from the numerical approximations of the convection term in the conservation equations over the past 20 years many numerical techniques have been developed to solve convection diffusion equations and none are problem free but false diffusion is one of the most serious problems and a major topic of controversy and confusion among numerical analysts
false loose smut is a fungal disease of barley caused by ustilago nigra this fungus is very similar to u nuda the cause of loose smut and was first distinguished from it in 1932
false memory is the psychological phenomenon in which a person recalls a memory that did not actually occur false memory is often considered in legal cases regarding childhood sexual abuse this phenomenon was initially investigated by psychological pioneers pierre janet and sigmund freud freud wrote the aetiology of hysteria where he discussed repressed memories of childhood sexual trauma in their relation to hysteria elizabeth loftus has since her debuting research project in 1974 been a lead researcher in memory recovery and false memories false memory syndrome recognizes false memory as a prevalent part of one s life in which it affects the person s mentality and day to day life false memory syndrome differs from false memory in that the syndrome is heavily influential in the orientation of a person s life while false memory can occur without this significant effect the syndrome takes effect because the person believes the influential memory to be true however its research is controversial and the syndrome is excluded from identification as a mental disorder and therefore is also excluded from the diagnostic and statistical manual of mental disorders false memory is an important part of psychological research because of the ties it has to a large number of mental disorders such as ptsd
in medical statistics false positives and false negatives are concepts analogous to type i and type ii errors in statistical hypothesis testing where a positive result corresponds to rejecting the null hypothesis and a negative result corresponds to not rejecting the null hypothesis the terms are often used interchangeably but there are differences in detail and interpretation
false pregnancy phantom pregnancy or hysterical pregnancy — officially called pseudocyesis in humans and pseudopregnancy in other mammals — is the appearance of clinical or subclinical signs and symptoms associated with pregnancy when the organism is not actually pregnant clinically false pregnancy is most common in veterinary medicine particularly in dogs and mice false pregnancy in humans is less common and may sometimes be purely psychological it is generally believed that false pregnancy is caused by changes in the endocrine system of the body leading to the secretion of hormones that cause physical changes similar to those during pregnancy some men experience the same illnesses as a woman would experience while pregnant when their partner is pregnant see couvade syndrome possibly caused by pheromones that increase estrogen prolactin and cortisol levels
in computer science false sharing is a performance degrading usage pattern that can arise in systems with distributed coherent caches at the size of the smallest resource block managed by the caching mechanism when a system participant attempts to periodically access data that will never be altered by another party but that data shares a cache block with data that is altered the caching protocol may force the first participant to reload the whole unit despite a lack of logical necessity the caching system is unaware of activity within this block and forces the first participant to bear the caching system overhead required by true shared access of a resource by far the most common usage of this term is in modern multiprocessor cpu caches where memory is cached in lines of some small power of two word size e g 64 aligned contiguous bytes if two processors operate on independent data in the same memory address region storable in a single line the cache coherency mechanisms in the system may force the whole line across the bus or interconnect with every data write forcing memory stalls in addition to wasting system bandwidth false sharing is an inherent artifact of automatically synchronized cache protocols and can also exist in environments such as distributed file system or databases but current prevalence is limited to ram caches
false vivipary is an abnormal condition found in many types of plants in which a plantlet is produced where the flower should appear it is not a completely understood topic but some say it could be caused by a hormonal mistake the plantlet which appears can be rooted and grown like normal plants this abnormal behavior can occasionally be seen in many types of carnivorous plants
familial mediterranean fever fmf also known as armenian disease is a hereditary inflammatory disorder fmf is an autoinflammatory disease caused by mutations in mefv a gene which encodes a 781 – amino acid protein denoted pyrin while all ethnic groups are susceptible to fmf it usually occurs in people of mediterranean origin — including sephardic jews armenians arabs greeks and italians the disorder has been given various names including familial paroxysmal polyserositis periodic peritonitis recurrent polyserositis benign paroxysmal peritonitis periodic disease or periodic fever reimann periodic disease or reimann s syndrome siegal cattan mamou disease and wolff periodic disease note that periodic fever can also refer to any of the periodic fever syndromes
familial adenomatous polyposis fap is an inherited condition in which numerous adenomatous polyps form mainly in the epithelium of the large intestine while these polyps start out benign malignant transformation into colon cancer occurs when they are left untreated three variants are known to exist fap and attenuated fap originally called hereditary flat adenoma syndrome are caused by apc gene defects on chromosome 5 while autosomal recessive fap or myh associated polyposis is caused by defects in the mutyh gene on chromosome 1 of the three fap itself is the most severe and most common although for all three the resulting colonic polyps and cancers are confined to the colon wall and removal can greatly reduce the spread of cancer the root cause of fap is understood to be a genetic mutation — a flaw in the body s tumour suppressor genes that prevent development of tumours the flaw allows numerous cells of the intestinal wall to develop into potentially cancerous polyps when they would usually reach the end of their life inevitably one or more will eventually progress and give rise to cancer 7 risk by age 21 rising to 87 by age 45 and 93 by age 50 the flawed genes do not trigger cancer but rather they reduce the body s ability to protect against the risk of aged cells becoming cancerous even with the flawed gene it may still take time before a cell actually does develop that is cancerous as a result and the gene may in some cases still partially operate to control tumours therefore cancer from fap takes many years to develop and is almost always an adult onset disease the second form of fap known as attenuated familial adenomatous polyposis has the apc gene functional but slightly impaired it is therefore somewhat able to operate as usual attenuated fap still presents a high 70 lifetime risk of cancer as estimated but typically presents with far fewer polyps typically 30 rather than the hundreds or thousands usually found in fap and arises at an age when fap is usually no longer considered likely — typically between 40 and 70 years old average 55 rather than the more usual 30 s upward because it has far fewer polyps options for management may be different the third variant autosomal recessive familial adenomatous polyposis or myh associated polyposis is also milder and as its name suggests requires both parents to be carriers to manifest the condition in some cases fap can manifest higher in the colon than usual for example the ascending colon or proximal to the splenic flexure or in the gastric or duodenal tracts where they show no symptoms until cancer is present and greatly advanced apc mutations have been linked to certain other cancers such as thyroid cancer as the mutation causing fap is genetic it can be inherited hereditarily from either parent and passed to children a genetic blood test of the apc gene exists that can determine whether it is deficient and therefore can predict the possibility of fap individuals at risk due to family links or genetic testing are usually offered routine monitoring of the intestinal tract every 1 – 5 years for life from early adulthood to detect the slow forming polyps and act if found before they can pose a threat international polyposis registries exists that track known cases of fap or apc gene defects for research and clinical purposes mutation of apc also occurs commonly in incident cases of colorectal carcinoma emphasizing its importance in this form of cancer
the familial amyloid neuropathies or familial amyloidotic neuropathies neuropathic heredofamilial amyloidosis familial amyloid polyneuropathy are a rare group of autosomal dominant diseases wherein the autonomic nervous system and or other nerves are compromised by protein aggregation and or amyloid fibril formation
familial atrial fibrillation is an autosomal dominant heart condition that causes disruptions in the heart s normal rhythm this condition is characterized by uncoordinated electrical activity in the heart s upper chambers the atria which causes the heartbeat to become fast and irregular
familial cirrhosis is a form of cirrhosis that is a keratin disease this particular type of cirrhosis is inherited and the liver scarring is not caused by any obvious disease process damage progresses until function becomes impaired current cirrhosis treatment is aimed at managing complications as well as chronic poor health related to liver damage treatments include abstinence from alcohol nutritional supplement identification of any identifiable disease process management of portal hypertension and liver transplantation it is associated with krt 8 and krt 18
familial dysautonomia fd sometimes called riley – day syndrome and hereditary sensory and autonomic neuropathy type iii hsan iii is a disorder of the autonomic nervous system which affects the development and survival of sensory sympathetic and some parasympathetic neurons in the autonomic and sensory nervous system resulting in variable symptoms including insensitivity to pain inability to produce tears poor growth and labile blood pressure episodic hypertension and postural hypotension people with fd have frequent vomiting crises pneumonia problems with speech and movement difficulty swallowing inappropriate perception of heat pain and taste as well as unstable blood pressure and gastrointestinal dysmotility fd does not affect intelligence originally reported by conrad milton riley and richard lawrence day in 1949 fd is one example of a group of disorders known as hereditary sensory and autonomic neuropathies hsan all hsan are characterized by widespread sensory dysfunction and variable autonomic dysfunction caused by incomplete development of sensory and autonomic neurons the disorders are believed to be genetically distinct from each other
familial dysbetalipoproteinemia or type iii hyperlipoproteinemia also known as remnant hyperlipidemia remnant hyperlipoproteinaemia broad beta disease and remnant removal disease is a condition characterized by increased total cholesterol and triglyceride levels and decreased hdl levels
familial encephalopathy with neuroserpin inclusion bodies fenib is a progressive disorder of the nervous system that is characterized by a loss of intellectual functioning dementia and seizures at first affected individuals may have difficulty sustaining attention and concentrating their judgment insight and memory become impaired as the condition progresses over time they lose the ability to perform the activities of daily living and most people with this condition eventually require comprehensive care the signs and symptoms of familial encephalopathy with neuroserpin inclusion bodies vary in their severity and age of onset in severe cases the condition causes seizures and episodes of sudden involuntary muscle jerking or twitching myoclonus in addition to dementia these signs can appear as early as a person s teens less severe cases are characterized by a progressive decline in intellectual functioning beginning in a person s forties or fifties mutations in the serpini 1 gene cause familial encephalopathy with neuroserpin inclusion bodies the serpini 1 gene provides instructions for making a protein called neuroserpin this protein is found in nerve cells where it plays a role in the development and function of the nervous system neuroserpin helps control the growth of nerve cells and their connections with one another which suggests that this protein may be important for learning and memory mutations in the gene result in the production of an abnormally shaped unstable version of neuroserpin abnormal neuroserpin proteins can attach to one another and form clumps called neuroserpin inclusion bodies or collins bodies within nerve cells these clumps disrupt the cells normal functioning and ultimately lead to cell death progressive dementia results from this gradual loss of nerve cells in certain parts of the brain researchers believe that a buildup of related potentially toxic substances in nerve cells may also contribute to the signs and symptoms of this condition this condition is inherited in an autosomal dominant pattern which means one copy of the altered gene in each cell is sufficient to cause the disorder in many cases an affected person has a parent with the condition
familial exudative vitreoretinopathy fevr pronounced fever is a genetic eye disorder affecting the growth and development of blood vessels in the retina of the eye this disease can lead to visual impairment and sometimes complete blindness in one or both eyes fevr is characterized by exudative leakage and hemorrhage of the blood vessels in the retina along with incomplete vascularization of the peripheral retina and can easily be confused with retinopathy of prematurity in premature infants the disease process often leads to retinal folds tears and detachments although fevr is a genetic condition it does not affect other parts of the body types include
familial hemiplegic migraine fhm is an autosomal dominant classical migraine subtype that typically includes weakness of half the body which can last for hours days or weeks it can be accompanied by other symptoms such as ataxia coma and paralysis there is clinical overlap in some fhm patients with episodic ataxia type 2 and spinocerebellar ataxia type 6 benign familial infantile epilepsy and alternating hemiplegia of childhood there are 3 known loci for fhm fhm 1 which accounts for approximately 50 of fhm patients is caused by mutations in a gene coding for the p q type calcium channel α subunit cacna 1 a fhm 1 is also associated with cerebellar degeneration fhm 2 which accounts for 25 of fhm cases is caused by mutations in the na k atpase gene atp 1 a 2 fhm 3 is a rare subtype of fhm and is caused by mutations in a sodium channel α subunit coding gene scn 1 a these three subtypes do not account for all cases of fhm suggesting the existence of at least one other locus fhm 4 many of the non familial cases of hemiplegic migraine sporadic hemiplegic migraine are also caused by mutations at these loci a fourth gene that has been associated with this condition is the proline rich transmembrane protein 2 prrt 2 an axonal protein associated with the exocytosis complex a fifth gene associated with this condition is slc 4 a 4 which encodes the electrogenic nahco 3 cotransporter nbce 1
familial hyperaldosteronism is a group of inherited conditions in which the adrenal glands which are small glands located on top of each kidney produce too much of the hormone aldosterone excess aldosterone causes the kidneys to retain more salt than normal which in turn increases the body s fluid levels and causes high blood pressure people with familial hyperaldosteronism may develop severe high blood pressure often early in life without treatment hypertension increases the risk of strokes heart attacks and kidney failure there are other forms of hyperaldosteronism that are not inherited familial hyperaldosteronism is categorized into three types distinguished by their clinical features and genetic causes in familial hyperaldosteronism type i hypertension generally appears in childhood to early adulthood and can range from mild to severe this type can be treated with steroid medications called glucocorticoids so it is also known as glucocorticoid remediable aldosteronism gra in familial hyperaldosteronism type ii hypertension usually appears in early to middle adulthood and does not improve with glucocorticoid treatment in most individuals with familial hyperaldosteronism type iii the adrenal glands are enlarged up to six times their normal size these affected individuals have severe hypertension that starts in childhood the hypertension is difficult to treat and often results in damage to organs such as the heart and kidneys rarely individuals with type iii have milder symptoms with treatable hypertension and no adrenal gland enlargement this condition is inherited in an autosomal dominant pattern which means one copy of the altered gene in each cell is sufficient to cause the disorder the various types of familial hyperaldosteronism have different genetic causes it is unclear how common these diseases are all together they appear to make up less than 1 of cases of hyperaldosteronism
familial hypercholesterolemia abbreviated fh also spelled familial hypercholesterolaemia is a genetic disorder characterized by high cholesterol levels specifically very high levels of low density lipoprotein ldl bad cholesterol in the blood and early cardiovascular disease since individuals with fh underlying body biochemistry is slightly different their high cholesterol levels are less responsive to the kinds of cholesterol control methods which are usually more effective in people without fh such as dietary modification and statin tablets nevertheless treatment including higher statin doses is usually effective many people have mutations in the ldlr gene that encodes the ldl receptor protein which normally removes ldl from the circulation or apolipoprotein b apob which is the part of ldl that binds with the receptor mutations in other genes are rare people who have one abnormal copy are heterozygous of the ldlr gene may develop cardiovascular disease prematurely at the age of 30 to 40 having two abnormal copies being homozygous may cause severe cardiovascular disease in childhood heterozygous fh is a common genetic disorder inherited in an autosomal dominant pattern occurring in 1 500 people in most countries homozygous fh is much rarer occurring in 1 in a million births heterozygous fh is normally treated with statins bile acid sequestrants or other lipid lowering agents that lower cholesterol levels new cases are generally offered genetic counseling homozygous fh often does not respond to medical therapy and may require other treatments including ldl apheresis removal of ldl in a method similar to dialysis and occasionally liver transplantation
familial hypertriglyceridemia is an autosomal dominant condition occurring in approximately 1 of the population triglyceride levels but not cholesterol are elevated as a result of excess hepatic production of vldl or heterozygous lpl deficiency the condition is associated with premature coronary disease though treatment sometimes differs from hypercholesterolemia affected individuals are at risk for chylomicronemia syndrome characterized by elevated chylomicrons in the blood they are also at risk of pancreatitis especially when triglyceride levels exceed 1000 mg dl
familial hypocalciuric hypercalcemia is a condition that can cause hypercalcemia a serum calcium level typically above 10 2 mg dl it is also known as familial benign hypocalciuric hypercalcemia fbhh where there is usually a family history of hypercalcemia which is mild a urine calcium to creatinine ratio 0 01 and urine calcium 200 mg day
familial isolated vitamin e deficiency is a rare autosomal recessive neurodegenerative disease symptoms are similar to those of friedreich ataxia
familial male limited precocious puberty often abbreviated as fmpp also known as familial sexual precocity or gonadotropin independent testotoxicosis is a form of gonadotropin independent precocious puberty in which boys experience early onset and progression of puberty signs of puberty can develop as early as an age of 1 year the spinal length in boys may be short due to a rapid advance in epiphyseal maturation it is an autosomal dominant condition with a mutation of the luteinizing hormone lh receptor treatment is with drugs that suppress gonadal steroidogenesis such as cyproterone acetate ketoconazole spironolactone and testolactone alternatively the combination of the androgen receptor antagonist bicalutamide and the aromatase inhibitor anastrozole may be used
familial multiple intestinal atresia is an inherited disorder where atresia occurs at multiple locations throughout the small and large intestines it presents at birth and the prognosis is very poor with almost all those diagnosed with this condition dying with one month it may be associated with combined immunodeficiency
familial partial lipodystrophy also known as köbberling – dunnigan syndrome is an autosomal dominant skin condition characterized by the loss of subcutaneous fat familial partial lipodystrophy also refers to a rare condition in which there is a loss of subcutaneous fat in the upper section of the body face to trunk however the lower half of the body remains unaffected type 1 is believed to be underdiagnosed
familial progressive hyperpigmentation is characterized by patches of hyperpigmentation present at birth which increase in size and number with age this is a genetic disease however the gene that accounts for this spotty darkening of the skin has yet to be discovered although rare the congenital disease is most prevalent among populations originating from china
familial renal amyloidosis or familial visceral amyloidosis or hereditary amyloid nephropathy is a form of amyloidosis primarily presenting in the kidney it is associated with fibrinogen alpha chain apolipoprotein a 1 and lysozyme it is also known as ostertag type after b ostertag who characterized it in 1932 and 1950
familial renal disease is an uncommon cause of renal failure kidney failure in dogs and cats most causes are breed related familial and some are inherited some are congenital present at birth renal dysplasia is a type of familial renal disease characterized by abnormal cellular differentiation of renal tissue dogs and cats with renal disease caused by these diseases have the typical symptoms of renal failure including weight loss loss of appetite depression and increased water consumption and urination a list of familial renal diseases by dog and cat breeds is found below
familial thoracic aortic aneurysm also referred to as familial aortic dissection or cystic medial necrosis of aorta is an autosomal dominant disorder of large arteries there is an association between familial thoracic aortic aneurysm marfan syndrome and massive baclofen overdose as well as other hereditary connective tissue disorders
photographical manipulation is the alteration of a photograph the u s national press photographers association nppa digital manipulation code of ethics states “ as journalists we believe the guiding principle of our profession is accuracy therefore we believe it is wrong to alter the content of a photograph in any way that deceives the public as photojournalists we have the responsibility to document society and to preserve its images as a matter of historical record it is clear that the emerging electronic technologies provide new challenges to the integrity of photographic images in light of this we the national press photographers association reaffirm the basis of our ethics accurate representation is the benchmark of our profession we believe photojournalistic guidelines for fair and accurate reporting should be the criteria for judging what may be done electronically to a photograph altering the editorial content is a breach of the ethical standards recognized by the nppa ”
in message oriented middleware solutions fan out is a messaging pattern used to model an information exchange that implies the delivery or spreading of a message to one or multiple destinations possibly in parallel and not halting the process that executes the messaging to wait for any response to that message also fan out in software construction means the number of classes used by a certain class or the number of methods called by a certain method
the fan effect is a psychological phenomenon under the branch of cognitive psychology where recognition times or error rate for a particular concept increases as more information about the concept is acquired the word fan refers to the number of associations correlated with the concept
fanconi anaemia fa is a rare genetic disease among those affected the majority develop cancer most often acute myelogenous leukemia and 90 develop bone marrow failure the inability to produce blood cells by age 40 about 60 – 75 of people have congenital defects commonly short stature abnormalities of the skin arms head eyes kidneys and ears and developmental disabilities around 75 of people have some form of endocrine problem with varying degrees of severity fa is the result of a genetic defect in a cluster of proteins responsible for dna repair treatment with androgens and hematopoietic blood cell growth factors can help bone marrow failure temporarily but the long term treatment is bone marrow transplant if a donor is available because of the genetic defect in dna repair cells from people with fa are sensitive to drugs that treat cancer by dna crosslinking such as mitomycin c the typical age of death was 30 years in 2000 fa occurs in about 1 per 130 000 births with a slightly higher frequency in ashkenazi jews in israel and afrikaners in south africa the disease is named after the swiss pediatrician who originally described this disorder guido fanconi it should not be confused with fanconi syndrome a kidney disorder also named after fanconi
fanconi syndrome or fanconi s syndrome english fɑːnˈkoʊni fæn is a syndrome of inadequate reabsorption in the proximal renal tubules of the kidney the syndrome can be caused by various underlying congenital or acquired diseases by toxicity for example from toxic heavy metals or by adverse drug reactions it results in various small molecules of metabolism being passed into the urine instead of being reabsorbed from the tubular fluid for example glucose amino acids uric acid phosphate and bicarbonate fanconi syndrome affects the proximal tubules namely the proximal convoluted tubule pct which is the first part of the tubule to process fluid after it is filtered through the glomerulus and the proximal straight tubule pars recta which leads to the descending limb of the loop of henle different forms of fanconi syndrome can affect different functions of the proximal tubule and result in different complications the loss of bicarbonate results in type 2 or proximal renal tubular acidosis the loss of phosphate results in the bone diseases rickets and osteomalacia even with adequate vitamin d and calcium levels because phosphate is necessary for bone development in children and even for ongoing bone metabolism in adults
in physics a fano resonance is a type of resonant scattering phenomenon that gives rise to an asymmetric line shape interference between a background and a resonant scattering process produces the asymmetric line shape it is named after italian american physicist ugo fano who gave a theoretical explanation for the scattering line shape of inelastic scattering of electrons from helium however ettore majorana was the first to discover this phenomenon because it is a general wave phenomenon examples can be found across many areas of physics and engineering
far sightedness also known as hyperopia is a condition of the eye where light focuses behind instead of on the retina this causes close objects to be blurry while far objects may appear normal as the disease worsens objects at all distances may be blurry other symptoms may include headaches and eye strain people with hyperopia can also experience accommodative dysfunction binocular dysfunction amblyopia and strabismus the cause is an imperfection in the eye often when the eyeball is too short or the lens cannot become round enough causing the eye to not have enough power to see close or nearby objects it is a type of refractive error correction is usually achieved by the use of convex corrective lenses for near objects the eye has to accommodate even more depending on the amount of hyperopia and the age of the person which directly relates to the eye s accommodative ability the symptoms can be different far sightedness primarily affects young children with rates of 8 at 6 years and 1 at 15 years
far east scarlet like fever or scarlatinoid fever is an infectious disease caused by the gram negative bacillus yersinia pseudotuberculosis in japan it is called izumi fever
farber disease also known as farber s lipogranulomatosis ceramidase deficiency fibrocytic dysmucopolysaccharidosis and lipogranulomatosis is an extremely rare 80 cases reported worldwide to this day autosomal recessive lysosomal storage disease marked by a deficiency in the enzyme ceramidase that causes an accumulation of fatty material sphingolipids leading to abnormalities in the joints liver throat tissues and central nervous system normally the enzyme ceramidase breaks down fatty material in the body ’ s cells in farber disease the gene responsible for making this enzyme is mutated hence the fatty material is never broken down and instead accumulates in various parts of the body leading to the signs and symptoms of this disorder
the farm to retail price spread is the difference between the farm price and the retail price of food reflecting charges for processing shipping and retailing farm goods sometimes called the marketing spread the current spread accounts for about three fourths of the retail price for a market basket of foods according to usda the farm value varies for each type of food for example in 2004 it accounted for about 35 of the retail cost of eggs compared to about 19 for fresh fruit and vegetables and about 6 for cereal and bakery products
farmer s lung not to be confused with silo filler s disease is a hypersensitivity pneumonitis induced by the inhalation of biologic dusts coming from hay dust or mold spores or other agricultural products it results in a type iii hypersensitivity inflammatory response and can progress to become a chronic condition which is considered potentially dangerous while inhaled allergens often provoke the creation of ige antibodies that circulate in the bloodstream these types of immune response are most often initiated by exposure to thermophilic actinomycetes most commonly saccharopolyspora rectivirgula which generates igg type antibodies following a subsequent exposure igg antibodies combine with the inhaled allergen to form immune complexes in the walls of the alveoli in the lungs this causes fluid protein and cells to accumulate in the alveolar wall which slows blood gas interchange and compromises the function of the lung
in medicine fasciitis ˌfæʃiˈaɪtɪs is an inflammation of the fascia which is the connective tissue surrounding muscles blood vessels and nerves in particular it often involves one of the following diseases necrotizing fasciitis plantar fasciitis eosinophilic fasciitis paraneoplastic fasciitis
fasciolopsiasis results from an infection by the trematode fasciolopsis buski the largest intestinal fluke of humans up to 7 5 cm in length
fasciolosis also known as fascioliasis fasciolasis distomatosis and liver rot is a parasitic worm infection caused by the common liver fluke fasciola hepatica as well as by fasciola gigantica the disease is a plant borne trematode zoonosis and is classified as a neglected tropical disease ntd it affects humans but its main host is ruminants such as cattle and sheep the disease progresses through four distinct phases an initial incubation phase of between a few days up to three months with little or no symptoms an invasive or acute phase which may manifest with fever malaise abdominal pain gastrointestinal symptoms urticaria anemia jaundice and respiratory symptoms the disease later progresses to a latent phase with less symptoms and ultimately into a chronic or obstructive phase months to years later in the chronic state the disease causes inflammation of the bile ducts gall bladder and may cause gall stones as well as fibrosis while chronic inflammation is connected to increased cancer rates it is unclear whether fasciolosis is associated with increased cancer risk up to half of those infected display no symptoms and diagnosis is difficult because the worm eggs are often missed in fecal examination the methods of detection are through fecal examination parasite specific antibody detection or radiological diagnosis as well as laparotomy in case of a suspected outbreak it may be useful to keep track of dietary history which is also useful for exclusion of differential diagnoses fecal examination is generally not helpful because the worm eggs can seldom be detected in the chronic phase of the infection eggs appear in the feces first between 9 – 11 weeks post infection the cause of this is unknown and it is also difficult to distinguish between the different species of fasciola as well distinguishing them from echinostomes and fasciolopsis most immunodiagnostic tests detect infection with very high sensitivity and as concentration drops after treatment it is a very good diagnostic method clinically it is not possible to differentiate from other liver and bile diseases radiological methods can detect lesions in both acute and chronic infection while laparotomy will detect lesions and also occasionally eggs and live worms because of the size of the parasite as adult f hepatica 20 – 30 × 13 mm 0 79 – 1 18 × 0 51 inches or adult f gigantica 25 – 75 × 12 mm fasciolosis is a big concern the amount of symptoms depend on how many worms and what stage the infection is in the death rate is significant in both sheep and cattle but generally low among humans treatment with triclabendazole has been highly effective against the adult worms as well as various developing stages praziquantel is not effective and older drugs such as bithionol are moderately effective but also cause more side effects secondary bacterial infection causing cholangitis has also been a concern and can be treated with antibiotics and toxaemia may be treated with prednisolone humans are infected by eating watergrown plants primarily wild grown watercress in europe or morning glory in asia infection may also occur by drinking contaminated water with floating young fasciola or when using utensils washed with contaminated water cultivated plants do not spread the disease in the same capacity human infection is rare even if the infection rate is high among animals especially high rates of human infection have been found in bolivia peru and egypt and this may be due to consumption of certain foods no vaccine is available to protect people against fasciola infection preventative measures are primarily treating and immunization of the livestock which are required to host the live cycle of the worms veterinary vaccines are in development and their use is being considered by a number of countries on account of the risk to human health and economic losses resulting from livestock infection other methods include using molluscicides to decrease the number of snails that act as vectors but it is not practical educational methods to decrease consumption of wild watercress and other waterplants has been shown to work in areas with a high disease burden in some areas of the world where fascioliasis has been found endemic special control programs are in place or have been planned the types of control measures depend on the setting such as epidemiologic ecologic and cultural factors strict control of the growth and sale of watercress and other edible water plants is important individual people can protect themselves by not eating raw watercress and other water plants especially from endemic grazing areas travelers to areas with poor sanitation should avoid food and water that might be contaminated tainted vegetables grown in fields that might have been irrigated with polluted water should be thoroughly cooked as should viscera from potentially infected animals fascioliasis occurs in europe africa the americas as well as oceania recently worldwide losses in animal productivity due to fasciolosis were conservatively estimated at over us 3 2 billion per annum fasciolosis is now recognized as an emerging human disease the world health organization who has estimated that 2 4 million people are infected with fasciola and a further 180 million are at risk of infection
as there were many different manifestations of fascism especially during the interwar years there were also many different symbols of fascist movements fascist symbolism typically involved nationalist imagery
western style fast food in china is a recent phenomenon dating back only to october 1987 when kentucky fried chicken still the most popular fast food chain in china established its first outlet in beijing kfc was later followed by mcdonalds which remains china s number two foreign fast food option in addition to american style fast food china has many local options including a slew of restaurants that attempt to imitate fast food particularly kfc
a fast radio burst frb is a high energy astrophysical phenomenon manifested as a transient radio pulse lasting only a few milliseconds these are bright unresolved broadband millisecond flashes found in parts of the sky outside the milky way the component frequencies of each burst are delayed by different amounts of time depending on the wavelength this delay is described by a value referred to as a dispersion measure fast radio bursts have dispersion measures which are much larger than expected for a source inside the milky way and consistent with propagation through an ionized plasma the origin of fast radio bursts is not known it is conjectured to be extragalactic because of the anomalously high value of pulse dispersion observed some have speculated that these signals might be signs of extraterrestrial intelligence fast radio bursts are named by the date the signal was recorded as yymmdd for example one on 26 june 2011 would be called frb 110626 the first frb found was frb 010621 on 19 january 2015 astronomers at australia s national science agency csiro reported from parkes that a fast radio burst had been observed for the first time live
a fat finger error is a keyboard input error in the financial markets such as the stock market or foreign exchange market whereby an order to buy or sell is placed of far greater size than intended for the wrong stock or contract at the wrong price or with any number of other input errors automated systems within trading houses may catch fat finger errors before they reach the market or such orders may be cancelled before they can be fulfilled the larger the order the more likely it is to be cancelled as it may be an order larger than the amount of stock available in the market fat finger errors are a product of the electronic processing of orders which requires details to be input using keyboards before trading was computerised erroneous orders were known as out trades which could be cancelled before proceeding erroneous orders placed using computers may be harder or impossible to cancel
a fat embolism is a type of embolism that is often caused by physical trauma such as fracture of long bones soft tissue trauma and burns
fat necrosis is a form of necrosis characterized by the action upon fat by digestive enzymes in fat necrosis the enzyme lipase releases fatty acids from triglycerides the fatty acids then complex with calcium to form soaps these soaps appear as white chalky deposits it is usually associated with trauma of the pancreas or acute pancreatitis it can also occur in the breast the salivary glands and neonates after a traumatic delivery
in computing a fatal error or fatal exception error is an error that causes a program to abort and may therefore return the user to the operating system when this happens data that the program was processing may be lost a fatal error is usually distinguished from a fatal system error colloquially referred to in the ms windows operating systems by the error message it produces as a blue screen of death a fatal error occurs typically in any of the following cases an illegal instruction has been attempted invalid data or code has been accessed an operation is not allowed in the current ring or cpu mode a program attempts to divide by zero only for integers with the ieee floating point standard this creates an infinity instead in some systems such as mac os x and microsoft windows a fatal error causes the operating system to create a log entry or to save an image core dump of the process
fatal familial insomnia ffi is an extremely rare autosomal dominant inherited prion disease of the brain it is almost always caused by a mutation to the protein prpc but can also develop spontaneously in patients with a non inherited mutation variant called sporadic fatal insomnia sfi ffi has no known cure and involves progressively worsening insomnia which leads to hallucinations delirium and confusional states like that of dementia the average survival span for patients diagnosed with ffi after the onset of symptoms is 18 months the mutated protein called prpsc has been found in just 40 families worldwide affecting about 100 people if only one parent has the gene the offspring have a 50 risk of inheriting it and developing the disease with onset usually around middle age it is essential that a potential patient be tested if they wish to avoid passing ffi on to their children the first recorded case was an italian man who died in venice in 1765
a fatberg is a congealed lump of fat sanitary items wet wipes and similar items found in sewer systems which do not break down like toilet paper such deposits are officially referred to by this term by authorities at thames water in london uk while fatbergs are problematic clogs in city sewer systems they have also been identified as a source of fuel specifically biogas this was also discussed on the first episode of the television show kevin mccloud s man made home on 23 september 2012 where mccloud is seen making biodiesel for a lamp out of london city sewer fatbergs
a broad classification for genetic disorders that result from an inability of the body to produce or utilize one enzyme that is required to oxidize fatty acids the enzyme can be missing or improperly constructed resulting in it not working this leaves the body unable to produce energy within the liver and muscles from fatty acid sources the body s primary source of energy is glucose however when all the glucose in the body has been expended a normal body digests fats individuals with a fatty acid metabolism disorder are unable to metabolize this fat source for energy halting bodily processes most individuals with a fatty acid metabolism disorder are able to live a normal active life with simple adjustments to diet and medications if left undiagnosed many complications can arise when in need of glucose the body of a person with a fatty acid metabolism disorder will still send fats to the liver the fats are broken down to fatty acids the fatty acids are then transported to the target cells but are unable to be broken down resulting in a build up of fatty acids in the liver and other internal organs fatty acid metabolism disorders are sometimes classified with the lipid metabolism disorders but in other contexts they are considered a distinct category
fatty liver also known as fatty liver disease fld or hepatic steatosis is a reversible condition wherein large vacuoles of triglyceride fat accumulate in liver cells via the process of steatosis i e abnormal retention of lipids within a cell despite having multiple causes fatty liver can be considered a single disease that occurs worldwide in those with excessive alcohol intake and the obese with or without effects of insulin resistance the condition is also associated with other diseases that influence fat metabolism when this process of fat metabolism is disrupted the fat can accumulate in the liver in excessive amounts thus resulting in a fatty liver it is difficult to distinguish alcoholic fld from nonalcoholic fld and both show microvesicular and macrovesicular fatty changes at different stages accumulation of fat may also be accompanied by a progressive inflammation of the liver hepatitis called steatohepatitis by considering the contribution by alcohol fatty liver may be termed alcoholic steatosis or nonalcoholic fatty liver disease nafld and the more severe forms as alcoholic steatohepatitis part of alcoholic liver disease and non alcoholic steatohepatitis nash
fault tolerant messaging or failover abstraction is the ability to transparently “ failover ” a call or request from one service transport protocol to another upon failure with no changes to the functional code or business logic implementation in elemenope this ability to “ failover ” is achieved via dispatcher failover dfo configuration the elemenope framework has the ability to configure multiple nested failover chains a typical use of the dfo functionality is the failover from a synchronous service transport protocol to an asynchronous service transport protocol for instance when an xml rpc service is down the messages may be failed over to an asynchronous jms queue implementation for processing when the service is available
in geology a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock mass movement large faults within the earth s crust result from the action of plate tectonic forces with the largest forming the boundaries between the plates such as subduction zones or transform faults energy release associated with rapid movement on active faults is the cause of most earthquakes a fault plane is the plane that represents the fracture surface of a fault a fault trace or fault line is the intersection of a fault plane with the ground surface a fault trace is also the line commonly plotted on geologic maps to represent a fault since faults do not usually consist of a single clean fracture geologists use the term fault zone when referring to the zone of complex deformation associated with the fault plane the two sides of a non vertical fault are known as the hanging wall and footwall by definition the hanging wall occurs above the fault plane and the footwall occurs below the fault this terminology comes from mining when working a tabular ore body the miner stood with the footwall under his feet and with the hanging wall hanging above him
fault detection isolation and recovery fdir is a subfield of control engineering which concerns itself with monitoring a system identifying when a fault has occurred and pinpointing the type of fault and its location two approaches can be distinguished a direct pattern recognition of sensor readings that indicate a fault and an analysis of the discrepancy between the sensor readings and expected values derived from some model in the latter case it is typical that a fault is said to be detected if the discrepancy or residual goes above a certain threshold it is then the task of fault isolation to categorize the type of fault and its location in the machinery fault detection and isolation fdi techniques can be broadly classified into two categories these include model based fdi and signal processing based fdi
the faun latin faunus ancient greek φαῦνος phaunos pronounced pʰaynos is a mythological half human – half goat from the head to the waist being human but with the addition of goat horns manifestation of forest and animal spirits that would help or hinder humans at whim they are often associated with the satyrs of greek mythology
favid of favus latin for honeycomb is a disease usually affecting the scalp but occurring occasionally on any part of the skin and even at times on mucous membranes the word “ favid ” is more used than french word “ favus ” which is close to the latin etymology
in gambling and economics the favourite longshot bias is an observed phenomenon where on average bettors tend to overvalue long shots and undervalue favourites that is in a horse race where one horse is given odds of 2 to 1 and another 100 to 1 the true odds might for example be 1 5 to 1 and 300 to 1 respectively betting on the long shot is therefore a much worse proposition than betting on the favourite in the long run losing 5 by betting on the favourite but losing 40 on longshots is not uncommon various theories exist to explain why people willingly bet on such losing propositions such as risk loving behavior risk averse behavior or simply inaccurate estimation as presented by sobel and raines
favre – racouchot syndrome also known as favre – racouchot disease and nodular cutaneous elastosis with cysts and comedones is a disorder consisting of multiple open comedones that occurs in skin damaged by sunlight especially under and lateral of the eyes the comedones are widened openings for hair follicles and sebaceous glands filled with material
fazio – londe disease fld also called progressive bulbar palsy of childhood is an very rare inherited motor neuron disease of children and young adults and is characterized by progressive paralysis of muscles innervated by cranial nerves
fear potentiated startle fps is a reflexive physiological reaction to a presented stimulus and is an indicator of the fear reaction in an organism the fps response can be elicited in the face of any threatening stimulus e g any object person or situation that would cause someone to experience feelings of fear but it can also be elicited by a neutral stimulus as a result of fear conditioning a process that occurs when a benign stimulus comes to evoke fear and anxiety upon being paired with a traumatic or fear provoking event the stimulus in question is usually of auditory e g loud noise or visual e g bright light nature and startle response measures include eyeblink rates and pulse heart rate the negative impact of heightened fps in the face of neutral stimuli can be treated pharmacologically using psychotropic medications that are typically used to reduce anxiety in humans recent literature moreover has implicated increased fps responses as a correlate in posttraumatic stress disorder ptsd and other anxiety disorders
feather plucking sometimes termed feather picking feather damaging behaviour or pterotillomania is a maladaptive behavioural disorder commonly seen in captive birds which chew bite or pluck their own feathers with their beak resulting in damage to the feathers and occasionally the skin it is especially common among psittaciformes with an estimated 10 of captive parrots exhibiting the disorder the areas of the body that are mainly pecked or plucked are the more accessible regions such as the neck chest flank inner thigh and ventral wing area contour and down feathers are generally identified as the main target although in some cases tail and flight feathers are affected although feather plucking shares characteristics with feather pecking commonly seen in commercial poultry the two behaviours are currently considered to be distinct as in the latter the birds peck at and pull out the feathers of other individuals feather plucking has characteristics that are similar to trichotillomania an impulse control disorder in humans and hair pulling which has been reported in mice guinea pigs rabbits sheep and muskox dogs and cats leading to suggestions for a comparative psychology approach to alleviating these problems
feather pecking is a behavioural problem that occurs most frequently amongst domestic hens reared for egg production although it does occur in other poultry such as pheasants turkeys ducks and is sometimes seen in farmed ostriches feather pecking occurs when one bird repeatedly pecks at the feathers of another two levels of severity are recognised gentle and severe gentle feather pecking is considered to be normal investigatory behaviour where the feathers of the recipient are hardly disturbed and therefore does not represent a problem in severe feather pecking however the feathers of the recipient are grasped pulled at and sometimes removed this is painful for the receiving bird and can lead to trauma of the skin or bleeding which in turn can lead to cannibalism and death feather pecking is one of the major problems facing the egg industry in non cagesystems and is set to become an even greater issue with the eu legislation council directive 1999 74 ec ban on the keeping of laying hens in barren battery cages which came into force in 2012 and the prospect of a ban on beak trimming see below reducing feather pecking without resorting to beak trimming is an important goal for the poultry industry
feather pillow dermatitis is a rash caused by bites of the psoroptidae species of mite
sweet s syndrome ss or acute febrile neutrophilic dermatosis is a skin disease characterized by the sudden onset of fever an elevated white blood cell count and tender red well demarcated papules and plaques that show dense infiltrates by neutrophil granulocytes on histologic examination the syndrome was first described in 1964 by robert douglas sweet it was also known as gomm button disease in honour of the first two patients sweet diagnosed with the condition
febrile non hemolytic transfusion reaction is a type of transfusion reaction that is associated with fever but not directly with hemolysis it is most commonly caused by antibodies directed against donor leukocytes and hla antigens this is in contrast to transfusion associated acute lung injury in which the donor plasma has antibodies directed against the recipient hla antigens mediating the characteristic lung damage alternatively fnhtr can be mediated by pre formed cytokines in the donor plasma as a consequence of white blood cell breakdown it is abbreviated fnhtr acetaminophen has been used in treatment and leukoreduction of future transfusions is sometimes performed
a febrile seizure also known as a fever fit or febrile convulsion is a seizure associated with a high body temperature but without any serious underlying health issue they most commonly occur in children between the ages of 6 months and 5 years most seizures are less than five minutes in duration and the child is completely back to normal within sixty minutes of the event febrile seizures may run in families the diagnosis involves verifying that there is not an infection of the brain there are no metabolic problems and there have not been prior seizures that have occurred without a fever there are two types of febrile seizures simple febrile seizures and complex febrile seizures simple febrile seizures involve an otherwise healthy child who has at most one tonic clonic seizure lasting less than 15 minutes in a 24 hour period blood testing imaging of the brain or an electroencephalogram eeg is typically not needed for the diagnosis examination to determine the source of the fever is recommended in otherwise healthy looking children a lumbar puncture is not necessarily required neither anti seizure medication nor anti fever medication are recommended in an effort to prevent further simple febrile seizures in the few cases that last greater than five minutes a benzodiazepine such as lorazepam or midazolam may be used outcomes are generally excellent with similar academic achievements to other children and no change in the risk of death for those with simple seizures there is tentative evidence that children have a slight increased risk of epilepsy at 2 febrile seizures affect two to ten percent of children before the age of five they are more common in boys than girls after a single febrile seizure there is a 15 to 70 chance of another one
the february 13 1979 windstorm is a natural phenomenon that took place on february 13 1979 in pacific canada and the united states during the early morning of february 13 1979 an intense wave cyclone moved across southern vancouver island british columbia south of the low center a strong atmospheric pressure gradient was carried across washington with associated high winds with a cold airflow moving toward the northeast interacting with the high terrain of the olympic mountains a lee low developed east of the olympics the mesoscale low caused a particularly intense pressure gradient to develop across the kitsap peninsula region
a fecal impaction is a solid immobile bulk of human feces that can develop in the rectum as a result of chronic constipation a related term is fecal loading which refers to a large volume of stool in the rectum of any consistency
fecal incontinence fi also called faecal incontinence bowel incontinence anal incontinence accidental bowel leakage or in some forms encopresis is a lack of control over defecation leading to involuntary loss of bowel contents — including flatus gas liquid stool elements and mucus or solid feces fi is a sign or a symptom not a diagnosis incontinence can result from different causes and might occur with either constipation or diarrhea continence is maintained by several inter related factors and usually there is more than one deficiency of these mechanisms for incontinence to develop the most common causes are thought to be immediate or delayed damage from childbirth complications from prior anorectal surgery especially involving the anal sphincters or hemorrhoidal vascular cushions and altered bowel habits e g caused by irritable bowel syndrome crohn s disease ulcerative colitis food intolerance or constipation with overflow incontinence an estimated 2 2 of community dwelling adults are affected fecal incontinence has three main consequences local reactions of the perianal skin and urinary tract including maceration softening and whitening of skin due to continuous moisture urinary tract infections or decubitus ulcers pressure sores a financial expense for individuals due to cost of medication and incontinence products and loss of productivity employers days off and medical insurers and society generally health care costs unemployment and an associated decrease in quality of life there is often reduced self esteem shame humiliation depression a need to organize life around easy access to bathroom and avoidance of enjoyable activities fi is an example of a stigmatized medical condition which creates barriers to successful management people may be too embarrassed to seek medical help and attempt to self manage the symptom in secrecy from others fi is one of the most psychologically and socially debilitating conditions in an otherwise healthy individual but it is generally treatable management may be achieved through an individualized mix of dietary pharmacologic and surgical measures health care professionals are often poorly informed about treatment options and may fail to recognize the effect of fi
fecal occult blood fob refers to blood in the feces that is not visibly apparent unlike other types of blood in stool such as melena or hematochezia a fecal occult blood test fobt checks for hidden occult blood in the stool feces newer tests look for globin dna or other blood factors including transferrin while conventional stool guaiac tests look for heme
fecal vomiting also called feculent vomiting and stercoraceous vomiting is a kind of vomiting wherein the material vomited is of fecal origin it is a common symptom of gastrojejunocolic fistula and intestinal obstruction in the ileum fecal vomiting is often accompanied by an odor of feces on the breath and other gastrointestinal symptoms including abdominal pain abdominal distension dehydration and diarrhea in severe cases of bowel obstruction or constipation such as those related to clozapine treatment fecal vomiting has been identified as a cause of death fecal vomiting occurs when the bowel is obstructed for some reason and intestinal contents cannot move normally peristaltic waves occur in an attempt to decompress the intestine and the strong contractions of the intestinal muscles push the contents backwards through the pyloric sphincter into the stomach where they are then vomited fecal vomiting can also occur in cats
fecaluria is the presence of feces in the urine
fecolith also called a fecaloma or faecaloma is an extreme form of fecal impaction often characterized by calcification the term fecalith literally means a stone made of feces lith stone it is a hardening of feces into lumps of varying size and may occur anywhere in the intestinal tract but is typically found in the colon it is also called appendicolith when it occurs in the appendix and is sometimes concomitant with appendicitis they can also obstruct diverticuli
federated architecture fa is a pattern in enterprise architecture that allows interoperability and information sharing between semi autonomous de centrally organized lines of business lobs information technology systems and applications architecture areas of concern organisational architecture business architecture process architecture information architecture this is an approach to the coordinated sharing and exchange of information which is organized by models which are describing common concepts and behavior the pattern emphasizes a controlled sharing and exchange of information among autonomous components by communication via messages highest possible autonomy shall be given to the different cooperating components in return they are expected to adhere to common models by using defined interfaces
a feed additive is a food supplements for farm animals that cannot get enough nutrients from regular meals that the farmers provide and include vitamins amino acids fatty acids and minerals in some cases if an animal does not have some specific nutrition in its diet it may not grow properly the nutritional values of animal feeds are influenced not only by their nutrient content but also by many other factors these include feed presentation hygiene digestibility and effect on intestinal health even with all of the benefits of higher quality feed most of a farm animal s diet still consists of maize wheat and soybean meal because of the higher costs of quality feed
feingold syndrome also called oculodigitoesophagoduodenal syndrome is a rare autosomal dominant hereditary disorder it is named after murray feingold an american physician who first described the syndrome in 1975 until 2003 at least 79 patients have been reported worldwide
the feist – benary synthesis is an organic reaction between α halogen ketones and β dicarbonyl compounds to produce substituted furan compounds this condensation reaction is catalyzed by amines such as ammonia and pyridine the first step in the ring synthesis is related to the knoevenagel condensation in the second step the enolate displaces an alkyl halogen in a nucleophilic aliphatic substitution feist benary synthesis a recent modification is the enantioselective interrupted feist benary reaction with a chiral auxiliary based on the cinchona alkaloid quinine based in the presence of proton sponge to the hydroxydihydrofuran this type of alkaloids is also used in asymmetric synthesis in the ad mix the alkaloid is protonated throughout the reaction and transfers its chirality by interaction of the acidic ammonium hydrogen with the dicarbonyl group of ethyl bromopyruvate in a 5 membered transition state interrupted feist benary reaction
in ancient roman culture felicitas from the latin adjective felix fruitful blessed happy lucky is a condition of divinely inspired productivity blessedness or happiness felicitas could encompass both a woman s fertility and a general s luck or good fortune the divine personification of felicitas was cultivated as a goddess although felicitas may be translated as good luck and the goddess felicitas shares some characteristics and attributes with fortuna the two were distinguished in roman religion fortuna was unpredictable and her effects could be negative as the existence of an altar to mala fortuna bad luck acknowledges felicitas however always had a positive significance she appears with that focus on aspects of her divine power felicitas had a temple in rome as early as the mid 2 nd century bc and during the republican era was honored at two official festivals of roman state religion on july 1 in conjunction with juno and october 9 as fausta felicitas felicitas continued to play an important role in imperial cult and was frequently portrayed on coins as a symbol of the wealth and prosperity of the roman empire her primary attributes are the caduceus and cornucopia the english word felicity derives from felicitas
the felicity effect is an effect observed during acoustic emission in a structure undergoing repeated mechanical loading it negates the effect of emission silence in the structure that is often observed from the related kaiser effect at high loads a material demonstrating the felicity effect gives off acoustic emission at a lower load than one previously reached in an increasing load cycle regime
feline acne is a problem seen in cats primarily involving the formation of blackheads accompanied by inflammation on the cat s chin and surrounding areas in many cases symptoms are mild and the disease does not require treatment more severe cases however may respond slowly to treatment and seriously detract from the health and appearance of the cat feline acne can affect cats of any age sex or breed sebaceous glands are mostly found in the skin of the chin base of the tail eyelids lips prepuce and scrotum they are connected to the hair follicles in acne the follicles become clogged with black sebaceous material forming comedones also known as blackheads these comedones can become irritated swollen and infected leading to pustules the cats may experience itching and discomfort due to swelling and bacterial growth inside infected glands secondary fungal infections species malassezia may also occur other conditions that can cause similar appearing conditions include skin mites ringworm yeast infection or auto immune diseases such as eosinophilic granuloma complex rodent ulcers
feline asthma is a common allergic respiratory disease in cats affecting at least one percent of all adult cats worldwide it is a chronic progressive disease for which there is no cure common symptoms include wheezing coughing labored breathing and potentially life threatening bronchoconstriction there is conjecture that the disease is becoming more common due to increased exposure to industrial pollutants
feline hyperesthesia syndrome also known as rolling skin disease is a rare illness in domestic cats that causes episodes of agitation self mutilation and a characteristic rippling of the skin when touched it is often described as a seizure disorder but the cause is unknown
feline infectious anemia fia is an infectious disease found in felines causing anemia and other symptoms the disease is caused by a variety of infectious agents most commonly mycoplasma haemofelis which used to be called haemobartonella haemobartonella and eperythrozoon species were reclassified as mycoplasmas coinfection often occurs with other infectious agents including feline leukemia virus felv feline immunodeficiency virus fiv ehrlichia species anaplasma phagocytophilum and candidatus mycoplasma haemominutum
feline infectious peritonitis fip is a fatal incurable disease that affects cats it is caused by feline infectious peritonitis virus fipv which is a mutation of feline enteric coronavirus fecv feline coronavirus fcov experts do not agree on the specifics of genetic changes that produce the fipv the mutated virus has the ability to invade and grow in certain white blood cells namely macrophages the immune system s response causes an intense inflammatory reaction in the containing tissues this disease is generally fatal however its incidence rate is roughly 1 in 5 000 for households with one or two cats a nasally administered vaccine for fip is available but controversial and it is not proven to be highly effective an experimental polyprenyl immunostimulant is being manufactured by sass and sass and tested by dr al legendre who described survival over 1 year in three cats diagnosed with fip and treated with the medicine in one case study a female cat diagnosed with dry fip has survived 26 months from the date of definitive diagnosis
feline tooth resorption tr is a syndrome in cats characterized by resorption of the tooth by odontoclasts cells similar to osteoclasts tr has also been called feline odontoclastic resorption lesion forl neck lesion cervical neck lesion cervical line erosion feline subgingival resorptive lesion feline caries or feline cavity it is one of the most common diseases of domestic cats affecting up to two thirds trs have been seen more recently in the history of feline medicine due to the advancing ages of cats but 800 year old cat skeletons have shown evidence of this disease purebred cats especially siamese and persians may be more susceptible trs clinically appear as erosions of the surface of the tooth at the gingival border they are often covered with calculus or gingival tissue it is a progressive disease usually starting with loss of cementum and dentin and leading to penetration of the pulp cavity resorption continues up the dentinal tubules into the tooth crown the enamel is also resorbed or undermined to the point of tooth fracture resorbed cementum and dentin is replaced with bone like tissue
feline panleukopenia virus fpv also known as feline infectious enteritis feline parvoviral enteritis feline ataxia feline distemper or cat plague is a viral infection affecting cats both domesticated and wild feline species it is caused by feline parvovirus a close relative of both type 2 canine parvovirus and mink enteritis once contracted it is highly contagious and can be fatal to the affected cat the name panleukopenia comes from the low white blood cell count leucocytes exhibited by affected animals
feline spongiform encephalopathy is a disease that affects the brains of felines it is caused by proteins called prions
feline viral rhinotracheitis fvr is an upper respiratory or pulmonary infection of cats caused by feline herpesvirus 1 of the family herpesviridae it is also commonly referred to as feline influenza feline coryza and feline pneumonia but as these terms describe other very distinct collections of respiratory symptoms they are misnomers for the condition viral respiratory diseases in cats can be serious especially in catteries and kennels causing one half of the respiratory diseases in cats fvr is the most important of these diseases and is found worldwide the other important cause of feline respiratory disease is feline calicivirus fvr is very contagious and can cause severe disease including death from pneumonia in young kittens it can cause flat chested kitten syndrome but most evidence for this is anecdotal all members of the felidae family are susceptible to fvr in fact fhv 1 has caused a fatal encephalitis in lions in germany
felty s syndrome also called felty syndrome is characterized by the combination of rheumatoid arthritis splenomegaly and neutropenia the condition is more common in those aged 50 – 70 years and is more prevalent in females than males and more in caucasians than those of african descent it is a deforming but inactive disease and seropositive for rf
female artist s novel is a literary subtype of kunstlerroman which can be defined as a literary procedure which deals with the main female protagonist ’ s growing to maturity and gaining experience and independence as an artist namely a writer based on the major assumptions of kunstlerroman female artist ’ s novel works as a portrayal of a woman ’ s artistic struggle as she acquires artistic freedom and masters the artistic craft of being a writer and gaining literary dexterity the scope of the genre is deeply rooted in the main assumptions of kunstlerroman where the growth of the character is displayed from one s youth to adulthood and deals with one s emotional and personal development on the way to artistic fulfillment as opposed to kunstlerroman female artist s novel focuses only on a female writer who besides being a capable artist and creator of her own reality is often to perform many social roles simultaneously e g the role of a wife a mother home guardian etc to meet expectations the society imposes on her the genre itself is more gendered due to its focus on a female position
female athlete triad is a syndrome in which eating disorders or low energy availability amenorrhoea oligomenorrhoea and decreased bone mineral density osteoporosis and osteopenia are present also known simply as the triad this condition is seen in females participating in sports that emphasize leanness or low body weight the triad is a serious illness with lifelong health consequences and can potentially be fatal
a female genital disease is a condition that affects the female reproductive system
female genital prolapse or vaginal prolapse or pelvic organ prolapse is characterized by a portion of the vaginal canal protruding prolapsing from the opening of the vagina the condition usually occurs when the pelvic floor collapses as a result of childbirth or heavy lifting which can tear soft tissues i e herniating fascia membranes so that the vaginal wall collapses resulting in cystocele rectocele or both remediation typically involves dietary and lifestyle changes physical therapy or surgery
female hysteria was a once common medical diagnosis reserved exclusively for women which is today no longer recognized by medical authorities as a medical disorder its diagnosis and treatment were routine for many hundreds of years in western europe hysteria of both genders was widely discussed in the medical literature of the nineteenth century women considered to have it exhibited a wide array of symptoms including faintness nervousness sexual desire insomnia fluid retention heaviness in the abdomen shortness of breath irritability loss of appetite for food or sex and a tendency to cause trouble in extreme cases the woman might be forced to enter an insane asylum or to undergo surgical hysterectomy
female infertility refers to infertility in female humans it affects an estimated 48 million women with the highest prevalence of infertility affecting people in south asia sub saharan africa north africa middle east and central eastern europe and central asia infertility is caused by many sources including nutrition diseases and other malformations of the uterus infertility affects women from around the world and the cultural and social stigma surrounding it varies
female sexual arousal disorder fsad is a disorder characterized by a persistent or recurrent inability to attain sexual arousal or to maintain arousal until the completion of a sexual activity the diagnosis can also refer to an inadequate lubrication swelling response normally present during arousal and sexual activity the condition should be distinguished from a general loss of interest in sexual activity and from other sexual dysfunctions such as the orgasmic disorder anorgasmia and hypoactive sexual desire disorder which is characterized as a lack or absence of sexual fantasies and desire for sexual activity for some period of time although female sexual dysfunction is currently a contested diagnostic it has become more common in recent years to use testosterone off label based drugs to treat fsad while drug companies are technically not allowed to market these drugs for off label uses sharing the information with doctors at cme conferences has proved to be an effective way to navigate around the fda approval process
feminist political theory is a diverse subfield of feminist theory working towards three main goals 1 to understand and critique the role of gender in how political theory is conventionally construed 2 to re frame and re articulate conventional political theory in light of feminist issues especially gender equality and 3 to support political science presuming and pursuing gender equality feminist political theory encompasses a broad scope of approaches it overlaps with related areas including feminist jurisprudence feminist legal theory feminist political philosophy female centered empirical research in political science and feminist research methods feminist method for use in political science the social sciences indeed one scholar notes that insofar as almost all versions of feminism involve demonstrating the ways in which politics understood as power relations is present in our everyday lives one could reasonably describe feminist theory as a whole as a kind of political philosophy what frequently distinguishes feminist political theory from feminism broadly is the specific examination of the state and its role in the reproduction or redressing of gender inequality in addition to being broad and multidisciplinary the field is relatively new inherently innovative and still expanding the stanford encyclopedia of philosophy explains that feminist political philosophy serves as a field for developing new ideals practices and justifications for how political institutions and practices should be organized and reconstructed
a femoral fracture is a bone fracture that involves the femur
a hernia is caused by the protrusion of a viscus in the case of groin hernias an intraabdominal organ through a weakness in the containing wall this weakness may be inherent as in the case of inguinal femoral and umbilical hernias on the other hand the weakness may be caused by surgical incision through the muscles of the abdominal thoracic wall hernias occurring through these are called incisional hernias femoral hernias occur just below the inguinal ligament when abdominal contents pass through a naturally occurring weakness called the femoral canal femoral hernias are a relatively uncommon type accounting for only 3 of all hernias while femoral hernias can occur in both males and females almost all of them develop in women because of the wider bone structure of the female pelvis femoral hernias are more common in adults than in children those that do occur in children are more likely to be associated with a connective tissue disorder or with conditions that increase intra abdominal pressure seventy percent of pediatric cases of femoral hernias occur in infants under the age of one a reducible femoral hernia occurs when a femoral hernia can be pushed back into the abdomen either spontaneously or with manipulation but most likely spontaneously this is the most common type of femoral hernia and is usually painless an irreducible femoral hernia occurs when a femoral hernia becomes stuck in the femoral canal this can cause pain and a feeling of illness an obstructed femoral hernia occurs when a part of the intestine becomes intertwined with the hernia causing an intestinal obstruction the obstruction may grow and the hernia can become increasingly painful vomiting may also result a strangulated femoral hernia occurs when a femoral hernia blocks blood supply to part of the bowel the loop of bowel loses its blood supply strangulation can happen in all hernias but is more common in femoral and inguinal hernias due to their narrow necks nausea vomiting and severe abdominal pain may occur with a strangulated hernia this is a medical emergency a strangulated intestine can result in necrosis tissue death followed by gangrene tissue decay this is a life threatening condition requiring immediate surgery a femoral hernia may be either reducible or irreducible and each type can also present as either or both obstructed or strangulated the term incarcerated femoral hernia is sometimes used but may have different meanings to different authors and physicians for example sometimes the hernia can get stuck in the canal and is called an irreducible or incarcerated femoral hernia the term incarcerated is sometimes used to describe an obstructed hernia that is irreducible but not strangulated thus an irreducible obstructed hernia can also be called an incarcerated one incarcerated hernia a hernia that cannot be reduced may lead to bowel obstruction but is not associated with vascular compromise however the term incarcerated seems to always imply that the femoral hernia is at least irreducible
femur fibula ulna syndrome ffu syndrome or femur fibula ulna complex is a very rare syndrome characterized by abnormalities of the femur thigh bone fibula calf bone and the ulna forearm bone there have been suggestions that ffu complex may be the same as proximal femoral focal deficiency pffd although authors are currently in disagreement over whether or not the disorders are in fact separate the breadth of the abnormality and number of limbs involved is considered sporadic although upper limbs are more affected than lower limbs and right side malformation is more prevalent than the left the condition was first noted by lenz and feldman in 1977
fenbendazole hoechst brand names panacur and safe guard intervet panacur and panacur rabbit is a broad spectrum benzimidazole anthelmintic used against gastrointestinal parasites including giardia roundworms hookworms whipworms the taenia genus of tapeworms but not effective against dipylidium caninum a common dog tapeworm pinworms aelurostrongylus paragonimiasis strongyles and strongyloides and can be administered to sheep cattle horses fish dogs cats rabbits and seals drug interactions may occur if salicylanilides like dibromsalan and niclosamide are co administered abortions in cattle and death in sheep have been reported
fenite is a metasomatic alteration associated particularly with carbonatite intrusions and created very rarely by advanced carbon dioxide alteration carbonation of felsic and mafic rocks fenite alteration is known but restricted in distribution around high temperature metamorphic talc carbonates generally in the form of an aureole around ultramafic rocks such examples include biotite rich zones amphibolite calcite scapolite alteration and other unusual skarn assemblages the process is called fenitization the type locality for fenite is the fen complex norwegian fensfeltet in nome telemark norway
in the field of unconventional superconductivity a fermi arc is a phenomenon visible in the pseudogap state of a superconductor seen in momentum space part of the space exhibits a gap in the density of states like in a superconductor this starts at the antinodal points and spreads through momentum space when lowering the temperature until everywhere is gapped and the sample is superconducting the area in momentum space that remains ungapped is called the fermi arc
in physics or engineering education a fermi problem fermi quiz fermi question fermi estimate or order estimation is an estimation problem designed to teach dimensional analysis approximation and such a problem is usually a back of the envelope calculation the estimation technique is named after physicist enrico fermi as he was known for his ability to make good approximate calculations with little or no actual data fermi problems typically involve making justified guesses about quantities and their variance or lower and upper bounds
the fermion doubling problem is a problem that is encountered when naively trying to put fermionic fields on a lattice it consists in the appearance of spurious states such that one ends up having 2 d fermionic particles with d the number of discretized dimensions for each original fermion in order to solve this problem several strategies are in use such as wilson fermions and staggered fermions
the fernandez reaction is a reaction that occurs to signal a positive result in the lepromin skin test for leprosy the reaction occurs in the skin at the site of injection if the body possesses antibodies to the dharmendra antigen one of the antigens found in mycobacterium leprae the bacteria that causes leprosy the reaction occurs via a delayed type hypersensitivity mechanism this reaction occurs within 48 hours of injection of lepromin and is seen in both lepromatous and tuberculoid forms of leprosy in contrast the mitsuda reaction occurs 5 – 6 weeks after injection of lepromin and is only seen in patients with the tuberculoid form of leprosy not the lepromatous form in which the body does not mount a strong response against the bacterium in terms of mechanism of action and appearance the reaction is similar to the tuberculin reaction of a positive mantoux test for tuberculosis
in electrical engineering the ferranti effect is an increase in voltage occurring at the receiving end of a long transmission line above the voltage at the sending end this occurs when the line is energized but there is a very light load or the load is disconnected the capacitive line charging current produces a voltage drop across the line inductance that is in phase with the sending end voltages considering the line resistance as negligible therefore both line inductance and capacitance are responsible for this phenomenon the ferranti effect will be more pronounced the longer the line and the higher the voltage applied the relative voltage rise is proportional to the square of the line length the ferranti effect is much more pronounced in underground cables even in short lengths because of their high capacitance it was first observed during the installation of underground cables in sebastian ziani de ferranti s 10 000 volt distribution system in 1887 in general practice we know that for all electrical systems current flows from the region of higher potential to the region of lower potential to compensate for the electrical potential difference that exists in the system in all practical cases the sending end voltage is higher than the receiving end so current flows from the source or the supply end to the load but sir s z ferranti in the year 1890 came up with an astonishing theory about medium distance transmission line or long distance transmission lines suggesting that in case of light loading or no load operation of transmission system the receiving end voltage often increases beyond the sending end voltage leading to a phenomena known as ferranti effect in power system
the ferrier carbocyclization or ferrier ii reaction is an organic reaction that was first reported by the carbohydrate chemist robert j ferrier in 1979 it is a metal mediated rearrangement of enol ether pyrans to cyclohexanones typically this reaction is catalyzed by mercury salts specifically mercury ii chloride several reviews have been published
the ferrier rearrangement is an organic reaction that involves a nucleophilic substitution reaction combined with an allylic shift in a glycal a 2 3 unsaturated glycoside it was discovered by the carbohydrate chemist robert j ferrier a typical ferrier rearrangement
ferroelasticity is a phenomenon in which a material may exhibit a spontaneous strain in ferroics ferroelasticity is the mechanical equivalent of ferroelectricity and ferromagnetism when stress is applied to a ferroelastic material a phase change will occur in the material from one phase to an equally stable phase either of different crystal structure e g cubic to tetragonal or of different orientation a twin phase this stress induced phase change results in a spontaneous strain in the material the shape memory effect and superelasticity are manifestations of ferroelasticity nitinol nickel titanium a common ferroelastic alloy can display either superelasticity or the shape memory effect at room temperature depending on the nickel titanium ratio
a dy pl ferruginous bodies is a histopathologic finding in interstitial lung disease suggestive of significant asbestos exposure asbestosis asbestos exposure is associated with occupations such as shipbuilding roofing plumbing and construction they appear as small brown nodules in the septum of the alveolus ferruginous bodies are typically indicative of asbestos inhalation when the presence of asbestos is verified they are called asbestos bodies in this case they are fibers of asbestos coated with an iron rich material derived from proteins such as ferritin and hemosiderin ferruginous bodies are believed to be formed by macrophages that have phagocytosed and attempted to digest the fibers
the fertile eunuch syndrome is a cause of hypogonadotropic hypogonadism caused by a lutheinizing hormone deficiency it is characterized by hypogonadism with spermatogenesis pasqualini and bur published the first case of eunuchoidism with preserved spermatogenesis in 1950 in la revista de la asociación médica argentina the hypoandrogenism with spermatogenesis syndrome included a eunuchoidism b testis with normal spermatogenesis and full volume with mature spermatozoids in a high proportion of seminiferous tubes and undifferentiated and immature leydig cells c full functional compensation through the administration of chorionic gonadotropin hormone while hcg is administered d total urinary gonadotrophins within normal limits e this definition implies the normal activity of the pituitary and the absence of congenital malformations in general in describing five other similar cases in 1953 mc cullagh al coined the term fertile eunuch introducing it in the english literature unfortunately this term is incorrect and should not be employed indeed these patients are not really eunuchs moreover as it will be explained later they are not usually fertile if not treated a first step in the understanding of the physiopathology of pasqualini syndrome was the absence of lutheinizing hormone lh in plasma and urine of patients the second breakthrough was the functional and genetic studies that validated the hypothesis of a functional deficit of lh in these men inactivating lh mutations will then also be described in some women different groups demonstrated in these cases a lh with varying degrees of immunological activity but biologically inactive in most of the patients due to one or more inactivating mutations in the lhb gene finally the full comprehension of pasqualini syndrome allowed to reverse the hypoandrogenic phenotype and to restore fertility in these patients through the use of chorionic gonadotropin and the modern in vitro fertility techniques
foetal maternal haemorrhage is the loss of fetal blood cells into the maternal circulation it takes place in normal pregnancies as well as when there are obstetric or trauma related complications to pregnancy normally the maternal circulation and the foetal circulation are kept from direct contact with each other with gas and nutrient exchange taking place across a membrane in the placenta made of two layers the syncytiotrophoblast and the cytotrophoblast foetal maternal haemorrhage occurs when this membrane ceases to function as a barrier and foetal cells may come in contact with and enter the maternal vessels in the decidua endometrium
fetal adenocarcinoma fa of the lung is a rare subtype of pulmonary adenocarcinoma that exhibits tissue architecture and cell characteristics that resemble fetal lung tissue upon microscopic examination it is currently considered a variant of solid adenocarcinoma with mucin production
fetal alcohol spectrum disorders fasds are a group of conditions that can occur in a person whose mother drank alcohol during pregnancy problems may include an abnormal appearance short height low body weight small head size poor coordination low intelligence behavior problems and problems with hearing or seeing those affected are more likely to have trouble in school legal problems participate in high risk behaviors and have trouble with alcohol or other drugs the most severe form of the condition is known as fetal alcohol syndrome fas other types include partial fetal alcohol syndrome pfas alcohol related neurodevelopmental disorder arnd and alcohol related birth defects arbd fetal alcohol spectrum disorders are caused by drinking alcohol during pregnancy surveys from the united states have found about 10 of pregnant women have drunk alcohol in the last month and 20 to 30 drank at some point during the pregnancy about 4 7 of north american women who are pregnant have alcoholism the risk of problems depends on the amount consumed and the frequency of consumption as well as when during pregnancy the alcohol is consumed other risk factors include an older mother smoking and poor diet there is no known safe amount or safe time to drink during pregnancy while drinking small amounts of alcohol does not cause abnormalities in the face it may cause behavioral issues alcohol crosses the blood brain barrier and both directly and indirectly affects a developing baby diagnosis is based on signs and symptoms in the person fetal alcohol spectrum disorders are preventable by avoiding alcohol medical organizations recommend no alcohol during pregnancy for this reason while the condition is permanent treatment can improve outcomes interventions may include parent child interaction therapy efforts to modify child behavior and possibly medications fasd is estimated to affect between 2 and 5 of people in the united states and western europe fas is believed to occur in between 0 2 and 9 per 1000 live births in the united states in south africa some populations have rates as high as 9 the negative effects of alcohol have been described since ancient times the lifetime cost per child with fas was 2 000 000 in 2002 the term fetal alcohol syndrome was first used in 1973
fetal aortic stenosis is a disorder that occurs when the fetus ’ aortic valve does not fully open during development the aortic valve is a one way valve that is located between the left ventricle and the aorta keeping blood from leaking back into the ventricle it has three leaflets that separate when the ventricle contracts to allow blood to move from the ventricle to the aorta these leaflets come together when the ventricle relaxes since the valve does not open properly in aortic stenosis there is a decrease in the forward movement of blood into the aorta fetal aortic stenosis impairs left ventricular development which can lead to hypoplastic left heart syndrome if untreated hlhs is lethal as a result of the inability of the left heart to pump enough blood to sustain normal organ function in fetal life this is condition is manageable because the ductus arteriosus acts as a bypass and supports the delivery of oxygenated blood to the systemic circulation however the ductus arteriosus closes during the first few days of life resulting in systemic circulation failure in babies born with aortic valve stenosis
fetal disease refers to disorders originating in utero examples include hydrops fetalis and chorioamnionitis
in medicine obstetrics the term fetal distress refers to the presence of signs in a pregnant woman — before or during childbirth — that suggest that the fetus may not be well because of its lack of precision the term is eschewed in modern american obstetrics
fetal hydantoin syndrome also called fetal dilantin syndrome is a group of defects caused to the developing fetus by exposure to the teratogenic effects of phenytoin or carbamazepine dilantin is the brand name of the drug phenytoin sodium in the united states commonly used in the treatment of epilepsy it may also be called congenital hydantoin syndrome fetal hydantoin syndrome dilantin embryopathy or phenytoin embryopathy association with ephx 1 has been suggested
rhabdomyoma is a benign mesenchymal tumor of skeletal muscle separated into two major categories based on site cardiac and extracardiac they are further separated by histology fetal myxoid and cellular juvenile intermediate and adult types genital types are recognized but are often part of either the fetal or juvenile types the fetal type is thought to recapitulate immature skeletal muscle at about week six to ten of gestational development
fetal thrombotic vasculopathy is a chronic disorder characterized by thrombosis in the fetus leading to vascular obliteration and hypoperfusion it is associated with cerebral palsy and stillbirth
fetal viability or foetal viability is the ability of a fetus to survive outside the uterus
fetal warfarin syndrome dysmorphism due to warfarin warfarin embryopathy is a condition associated with administration of warfarin during pregnancy associated conditions include hypoplasia of nasal bridge laryngomalacia pectus carinatum congenital heart defects ventriculomegaly agenesis of the corpus callosum stippled epiphyses telebrachydactyly and growth retardation it is also known as disaia syndrome the symptoms are nasal hypoplasia depressed nasal bridge deep groove between nostril and nasal tip stippling of uncalcified epiphyses during first year mild hypoplasia of nails shortened fingers low birth weight significant intellectual disability seizures reduced muscle tone widely spaced nipples deafness and feeding difficulty
generally a foul or unpleasant odor in medical contexts fetor refers to an unpleasant odor emanating from an individual specific types include fetor oris another term for halitosis fetor hepaticus uremic fetor body odor rectal fetor
fetor hepaticus or foetor hepaticus see spelling differences also known as breath of the dead or hepatic foetor is a condition seen in portal hypertension where portosystemic shunting allows thiols to pass directly into the lungs it is a late sign in liver failure and is one of the clinical features of hepatic encephalopathy other possible causes are the presence of ammonia and ketones in the breath the breath has a sweet fecal smell to it the compound dimethyl sulfide has been associated with it raising the possibility of an objective noninvasive measure of liver failure furthermore the volatile dimethyl sulfide is thought by some researchers to be the main contributor to the odor of fetor hepaticus a secondary form of trimethylaminuria is also associated with liver failure and it has been suggested that that trimethylamine is also a contributor to the odor of fetor hepaticus foetor hepaticus is sometimes often associated with an acid base disorder such as diabetic ketoacidosis or isopropyl alcohol intoxication
fetus in fetu or foetus in foetu is a developmental abnormality in which a mass of tissue resembling a fetus forms inside the body there are two theories of origin concerning fetus in fetu one theory is that the mass begins as a normal fetus but becomes enveloped inside its twin the other theory is that the mass is a highly developed teratoma fetus in fetu is estimated to occur in 1 in 500 000 live births
fever of unknown origin fuo pyrexia of unknown origin puo or febris e causa ignota febris e c i refers to a condition in which the patient has an elevated temperature fever but despite investigations by a physician no explanation has been found if the cause is found it is usually a diagnosis of exclusion that is by eliminating all possibilities until only one explanation remains and taking this as the correct one
in lisp programming languages a fexpr is a function whose operands are passed to it without being evaluated when a fexpr is called only the body of the fexpr is evaluated no other evaluations take place except when explicitly initiated by the fexpr in contrast when an ordinary lisp function is called the operands are evaluated automatically and only the results of these evaluations are provided to the function and when a traditional lisp macro is called the operands are passed in unevaluated but whatever result the macro function returns is automatically evaluated
the upper and lower fezouata formations of morocco are burgess shale type deposits dating to the lower ordovician filling an important preservational window between the common cambrian lagerstätten and the late ordovician soom shale in the fossilized fauna were numerous organisms previously thought to have died out after the mid cambrian
in chess the fianchetto italian fiaŋˈkɛtto little flank is a pattern of development wherein a bishop is developed to the second rank of the adjacent knight file the knight pawn having been moved one or two squares forward the fianchetto is a staple of many hypermodern openings whose philosophy is to delay direct occupation of the center with the plan of undermining and destroying the opponent s central outpost it also regularly occurs in indian defences the fianchetto is less common in open games 1 e 4 e 5 but the king s bishop is sometimes fianchettoed by black in the spanish game or by white in an uncommon variation of the vienna game one of the major benefits of the fianchetto is that it often allows the fianchettoed bishop to become more active because the bishop is placed on one of the two longest diagonals either h 1 a 8 or a 1 h 8 it controls the maximum possible number of squares and can become a powerful offensive weapon however a fianchettoed position also presents some opportunities for the opposing player if the fianchettoed bishop can be exchanged the squares the bishop was formerly protecting will become weak see hole and can form the basis of an attack particularly if the fianchetto was performed on the kingside therefore exchanging the fianchettoed bishop should not be done lightly especially if the enemy bishop of the same colour is still on the board
a fibrin ring granuloma also known as doughnut granuloma is a histopathological finding that is characteristic of q fever on hematoxylin eosin staining the fibrin ring granuloma consists of a central lipid vacuole usually washed out during fixing and staining leaving only an empty hole surrounded by a dense red fibrin ring and epithelioid macrophages fibrin ring granulomas may also be seen in hodgkin s disease and infectious mononucleosis
primary fibrinogenolysis is a medical condition that appears with abnormal production of fibrinogen fibrin degradation products fdp degradation of coagulation factors v viii ix xi and or degradation of the fibrin present in any pre existing localized thrombi and hemostatic clots
fibrinolysis syndrome also known as defibrinating syndrome is characterized by an acute hemorrhagic state brought about by inability of the blood to clot with massive hemorrhages into the skin producing blackish purplish swellings and sloughing
fibroadenomas of the breast are benign tumors characterized by an admixture of stromal and epithelial tissue since both fibroadenomas and breast cancer can appear as similar lumps it is currently recommended to perform ultrasound analyses and possibly tissue sampling with subsequent histopathologic analysis in order to perform diagnosis unlike typical lumps from breast cancer fibroadenomas are easy to move with clearly defined edges fibroadenomas are sometimes called breast mice or a breast mouse owing to their high mobility in the breast
fibrocartilaginous mesenchymoma of bone is fcmb is an extremely rare tumor first described in 1984 fewer than 20 cases have been reported with patient ages spanning from 9 to 25 years though a case in a male infant aged 1 year and 7 months has been reported quick growth and bulky size are remarkable features of this tumor
fibrochondrogenesis is a rare autosomal recessive form of osteochondrodysplasia causing abnormal fibrous development of cartilage and related tissues it is a lethal rhizomelic malformations which result in short underdeveloped limbs form of dwarfism exhibiting both skeletal dysplasia malformations of bone and fibroblastic dysplasia abnormal development of fibroblasts specialized cells that make up fibrous connective tissue which plays a role in the formation of cellular structure and promotes healing of damaged tissues death caused by complications of fibrochondrogenesis occurs in infancy
fibrocystic breasts or fibrocystic breast disease or fibrocystic breast condition commonly referred to as fbc is a condition of breast tissue affecting an estimated 30 60 of women and at least 50 of women of childbearing age some studies indicate that the lifetime prevalence of fbc may be as high as 70 to 90 it is characterized by noncancerous breast lumps which can sometimes cause discomfort often periodically related to hormonal influences from the menstrual cycle
fibrodysplasia ossificans progressiva fop is an extremely rare connective tissue disease the disease is caused by a mutation of the body s repair mechanism which causes fibrous tissue including muscle tendon and ligament to be ossified spontaneously or when damaged in many cases injuries can cause joints to become permanently frozen in place surgical removal of the extra bone growths has been shown to cause the body to repair the affected area with even more bone
fibroepithelial neoplasms or tumors are biphasic tumors this means they consist of epithelial tissue and stromal or mesenchymal tissue they may be benign or malignant examples include brenner tumor of the ovary fibroadenoma of the breast phyllodes tumor of the breast
fibrolamellar hepatocellular carcinoma fhcc is a rare form of hepatocellular carcinoma hcc that typically affects young adults and is characterized under the microscope by laminated fibrous layers interspersed between the tumour cells approximately 200 new cases are diagnosed worldwide each year
fibromas or fibroid tumors or fibroids are benign tumors that are composed of fibrous or connective tissue they can grow in all organs arising from mesenchyme tissue the term fibroblastic or fibromatous is used to describe tumors of the fibrous connective tissue when the term fibroma is used without modifier it is usually considered benign with the term fibrosarcoma reserved for malignant tumors
fibroma of tendon sheath is a benign tumor that presents as a small subcutaneous nodule that slowly increases in size the tumors often have a multinodular growth pattern with individual nodules being composed of bland slender spindle shaped cells myofibroblasts in a dense fibrous matrix ” a common microscopic finding is the presence of elongated slit like blood vessels the lesions nearly always arise in the distal portions of the extremities they often occur on the fingers hands toes or feet although they are benign they may recur in up to 40 of cases although they may be regarded as a tumor of the skin the lesions arise from tendons and aponeuroses in superficial sites and are therefore properly classified as in the category soft tissue tumor the biological nature of fibroma of tendon sheath is not known but the category appears to comprise a number of different pathologic processes it is considered that about one third of the lesions in this category may be acral variants of the entity nodular fasciitis
the term fibromatosis refers to a group of benign soft tissue tumors which have certain characteristics in common including absence of cytologic and clinical malignant features a histology consistent with proliferation of well differentiated fibroblasts an infiltrative growth pattern and aggressive clinical behavior with frequent local recurrence
fibromatosis colli also known as sternomastoid tumor of infancy is a benign proliferation of fibrous tissue infiltrating the lower third of the sternocleidomastoid scm and is the most common cause of neonatal torticollis the mass also known as a hematoma of the sternocleidomastoid is firm and hard on palpation but is neither tender nor inflamed the mass is easily diagnosed using ultrasound where it is found within the scm and enlarges the muscle the lesion is self limiting and benign usually resolving with time and physical therapy rarely does it need to be removed surgically surgery is performed on patients in whom torticollis persists for 1 year
fibromuscular dysplasia fmd is a non atherosclerotic non inflammatory disease of the blood vessels that causes abnormal growth within the wall of an artery fmd has been found in nearly every arterial bed in the body however the most common arteries affected are the renal and carotid arteries there are various types of fmd with multi focal fibroplasia being the most common focal previously known as intimal and adventitial are less common forms of the disease fmd predominantly affects middle aged women but has been found in men and people of all ages pediatric cases of fmd are vastly different from that of the adult population the prevalence of fmd is not known although the disease was initially thought to be rare recent studies have suggested that fmd may be underdiagnosed
fibromyalgia fm is a medical condition characterised by chronic widespread pain and a heightened pain response to pressure other symptoms include feeling tired to a degree that normal activities are affected sleep problems and troubles with memory some people also report restless legs syndrome bowel or bladder problems numbness and tingling and sensitivity to noise lights or temperature fibromyalgia is frequently associated with depression anxiety and posttraumatic stress disorder other types of chronic pain are also frequently present the cause of fibromyalgia is unknown but believed to involve a combination of genetic and environmental factors with half the risk attributed to each the condition runs in families and many genes are believed to be involved environmental factors may include psychological stress trauma and certain infections the pain appears to result from processes in the central nervous system and the condition is referred to as a central sensitization syndrome fibromyalgia is recognized as a disorder by the us national institutes of health and the american college of rheumatology there is no specific diagnostic test diagnosis involves first ruling out other potential causes and verifying that a set number of symptoms are present the treatment of fibromyalgia can be difficult recommendations often include getting enough sleep exercising regularly and eating a healthy diet cognitive behavioral therapy may also be helpful the medications duloxetine milnacipran or pregabalin may be used use of opioid pain medication is controversial with some stating their use is poorly supported by evidence and others saying that weak opioids may be reasonable if other medications are not effective dietary supplements also lack evidence to support their use while fibromyalgia can last a long time it does not result in death or tissue damage fibromyalgia is estimated to affect 2 – 8 of the population females are affected about twice as often as males rates appear similar in different areas of the world and among different cultures fibromyalgia was first defined in 1990 with updated criteria in 2011 there is controversy about the classification diagnosis and treatment of fibromyalgia while some feel the diagnosis of fibromyalgia may negatively affect a person other research finds it to be beneficial the term fibromyalgia is from new latin fibro meaning fibrous tissues greek μυώ myo muscle and greek άλγος algos pain thus the term literally means muscle and connective tissue pain
fibropapillomatosis fp is a disease specific to sea turtles the condition is characterized by benign epithelial tumours on the surface of biological tissues a herpesvirus is believed to be the causative agent of the disease while turtle leeches are suspected mechanical vectors transmitting the disease to other individuals the disease is thought to have a multifactorial etiology including a tumour promoting phase that is possibly caused by biotoxins or contaminants fp exists all over the world but it is most prominent in warmer climates affecting up to 50 70 of some populations
fibrosarcoma fibroblastic sarcoma is a malignant mesenchymal tumour derived from fibrous connective tissue and characterized by the presence of immature proliferating fibroblasts or undifferentiated anaplastic spindle cells in a storiform pattern it is usually found in males aged 30 to 40 it originates in fibrous tissues of the bone and invades long or flat bones such as femur tibia and mandible it also involves periosteum and overlying muscle
fibrosclerosis of the breast is most frequently used to mean sclerosing lobular adenosis of the breast it is not well known if it is related to non sclerosing adenosis of the breast which is normally classified as fibrocystic breast changes and unlike this it is believed to be correlated with an elevated risk of breast cancer
fibrosing colonopathy is a disease that arises in patients with cystic fibrosis treated with enteric coated pancreatic enzyme supplements the disease is associated with high dose of these supplements the clinical presentation of fibrosing colonopathy is non specific abdominal pain distension vomiting and constipation are frequentfeatures and have led initially to confusion with distal intestinal obstruction syndrome in some instances the clinical and radiological features were suggestive of crohn s disease or inflammatory colitis
fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process this can be a reactive benign or pathological state in response to injury this is called scarring and if fibrosis arises from a single cell line this is called a fibroma physiologically fibrosis acts to deposit connective tissue which can obliterate the architecture and function of the underlying organ or tissue fibrosis can be used to describe the pathological state of excess deposition of fibrous tissue as well as the process of connective tissue deposition in healing defined by the pathological accumulation of extracellular matrix ecm proteins fibrosis results in scarring and thickening of the affected tissue it is in essence an exaggerated wound healing response which interferes with normal organ function
fibrothorax is diffuse fibrosis of the pleural space surrounding the lungs it can have several causes including hemothorax pleural effusion and tuberculosis it may also be induced by exposure to certain substances as with asbestos induced diffuse pleural fibrosis idiopathic fibrothorax may also occur in fibrothorax scar tissue is formed around the visceral pleura following inflammation due to pleural effusion or other pathology the scar tissue lies in a sheet between the pleura then fuses with the parietal pleura and the chest wall over time generally the course of years the fibrotic scar tissue slowly tightens which results in the contraction of the entire hemithorax and leaves the ribs immobilized within the chest the lung is compressed and unable to expand making it vulnerable to collapse at the microscopic level the scar tissue is composed of collagen fibers deposited in a basket weave pattern the treatment for fibrothorax is decortication the surgical removal of the fibrous layer of scar tissue however since many of the diseases and conditions resulting in fibrothorax are treatable prevention remains the preferred method of managing fibrothorax pleural fibrosis calcification dense pleural fibrosis with focal calcification seen here is the end result of organization of intrapleural inflammatory exudate empyema most likely accompanying a remote episode of pneumonia
fibrous ankylosis is a fibrous connective tissue process which results in decreased range of motion symptoms present as bony ankylosis in which osseous tissue fuses two bones together reducing mobility which is why fibrous ankylosis is also known as false ankylosis pathology may be the result of trauma disease chronic inflammation or surgery some research suggests fibrous ankylosis may precede the development of bony ankylosis
fibrous dysplasia is a disorder where normal bone and marrow is replaced with fibrous tissue resulting in formation of bone that is weak and prone to expansion as a result most complications result from fracture deformity functional impairment and pain disease occurs along a broad clinical spectrum ranging from asymptomatic incidental lesions to severe disabling disease disease can affect one bone monostotic or multiple polyostotic and may occur in isolation or in combination with cafe au lait skin macules and hyperfunctioning endocrinopathies termed mccune albright syndrome more rarely fibrous dysplasia may be associated with intramuscular myxomas termed mazabraud s syndrome fibrous dysplasia is very rare and there is no known cure fibrous dysplasia is not a form of cancer
a fibrous tissue neoplasm is a tumor derived primarily from fibrous connective tissue an example is fibroma
fibular hemimelia or longitudinal fibular deficiency is the congenital absence of the fibula and it is the most common congenital absence of long bone of the extremities it is the shortening of the fibula at birth or the complete lack thereof in humans the disorder can be noted by ultrasound in utero to prepare for amputation after birth or complex bone lengthening surgery the amputation usually takes place at six months with removal of portions of the legs to prepare them for prosthetic use the other treatments which include repeated corrective osteotomies and leg lengthening surgery are costly and associated with residual deformity
fiddler s neck sometimes referred to as a violin hickey is an occupational disease that affects violin and viola players it is a cutaneous condition usually characterized by redness thickening and inflammation on the left side of the neck below the angle of the jaw where the instrument is held acne like lesions and cysts may form at the site due to foreign body reactions and infections may also occur due to poor hygiene the primary causes of fiddler s neck are constant friction and local pressure it is well known among professional orchestra musicians but is not well recognized by dermatologists and a red mark on the left side of the neck under the jaw functions as an identifying sign of a violinist or violist in public without seeing the instrument although the presence of fiddler s neck is sometimes used as an indicator of a violinist s skill or battle scars from constant practice many violinists never develop fiddler s neck due to differences in skin sensitivity playing habits and the materials used in the construction of the instrument an accomplished professional player could practice hard their whole life and never develop fiddler s neck
field capacity is the amount of soil moisture or water content held in the soil after excess water has drained away and the rate of downward movement has decreased this usually takes place 2 – 3 days after rain or irrigation in pervious soils of uniform structure and texture the physical definition of field capacity expressed symbolically as θfc is the bulk water content retained in soil at − 33 j kg or − 0 33 bar of hydraulic head or suction pressure the term originated from israelson and west and frank veihmeyer and arthur hendrickson veihmeyer and hendrickson realized the limitation in this measurement and commented that it is affected by so many factors that precisely it is not a constant for a particular soil yet it does serve as a practical measure of soil water holding capacity field capacity improves on the concept of moisture equivalent by lyman briggs veihmeyer hendrickson proposed this concept as an attempt to improve water use efficiency for farmers in california during 1949 field capacity is characterized by measuring water content after wetting a soil profile covering it to prevent evaporation and monitoring the change soil moisture in the profile water content when the rate of change is relatively small is indicative of when drainage ceases and is called field capacity it is also termed drained upper limit dul lorenzo a richards and weaver found that water content held by soil at a potential of − 33 kpa or − 0 33 bar correlate closely with field capacity − 10 kpa for sandy soils
the field of view is the extent of the observable world that is seen at any given moment in case of optical instruments or sensors it is a solid angle through which a detector is sensitive to electromagnetic radiation
in first person video games the field of view or field of vision abbreviated fov is the extent of the observable game world that is seen on the display at any given moment it is typically measured as an angle although whether this angle is the horizontal vertical or diagonal component of the field of view varies from game to game the fov in a video game may change depending on the aspect ratio of the rendering resolution in computer games and modern game consoles the fov normally increases with a wider aspect ratio of the rendering resolution
in mathematics the field trace is a particular function defined with respect to a finite field extension l k which is a k linear map from l onto k
erythema infectiosum or fifth disease is one of several possible manifestations of infection by parvovirus b 19 the disease is also referred to as slapped cheek syndrome slapcheek slap face or slapped face the name fifth disease comes from its place on the standard list of rash causing childhood diseases which also includes measles 1 st scarlet fever 2 nd rubella 3 rd and dukes disease 4 th though the last is no longer widely accepted as distinct
the fight or flight response also called hyperarousal or the acute stress response is a physiological reaction that occurs in response to a perceived harmful event attack or threat to survival it was first described by walter bradford cannon his theory states that animals react to threats with a general discharge of the sympathetic nervous system preparing the animal for fighting or fleeing more specifically the adrenal medulla produces a hormonal cascade that results in the secretion of catecholamines especially norepinephrine and epinephrine the hormones estrogen testosterone and cortisol as well as the neurotransmitters dopamine and serotonin also affect how organisms react to stress this response is recognized as the first stage of the general adaptation syndrome that regulates stress responses among vertebrates and other organisms
figurate erythema is a form of erythema that presents in a ring or an arc shape an example is erythema marginatum
filamentation is the anomalous growth of certain bacteria such as e coli in which cells continue to elongate but do not divide no septa formation the cells that result from elongation without division have multiple chromosomal copies bacterial filamentation is often observed as a result of bacteria responding to various stresses including dna damage or inhibition of replication this may happen for example while responding to extensive dna damage through the sos response system nutritional changes may also cause bacterial filamentation some of the key genes involved in filamentation in e coli include sula and mincd the following genes have been connected to virulence using the g mellonella infection model bcr 1 flo 8 kem 1 suv 3 and tec 1 these genes are required for biofilm development from filamentation filamentation properties are argued to be necessary in virulence the biofilm of bacteria is also connected to the organism ’ s virulence filamentation is a survival strategy that protects bacteria from stressors such as host effectors and protist predators the strategy of filamentation is known to protect bacteria from antibiotic medicines taken by the host
filariasis or philariasis is a parasitic disease caused by an infection with roundworms of the filarioidea type these are spread by blood feeding black flies and mosquitoes this disease belongs to the group of diseases called helminthiases eight known filarial nematodes use humans as their definitive hosts these are divided into three groups according to the niche within the body they occupy lymphatic filariasis is caused by the worms wuchereria bancrofti brugia malayi and brugia timori these worms occupy the lymphatic system including the lymph nodes in chronic cases these worms lead to the syndrome of elephantiasis subcutaneous filariasis is caused by loa loa the eye worm mansonella streptocerca and onchocerca volvulus these worms occupy the subcutaneous layer of the skin in the fat layer l loa causes loa loa filariasis while o volvulus causes river blindness serous cavity filariasis is caused by the worms mansonella perstans and mansonella ozzardi which occupy the serous cavity of the abdomen the adult worms which usually stay in one tissue release early larval forms known as microfilariae into the host s bloodstream these circulating microfilariae can be taken up with a blood meal by the arthropod vector in the vector they develop into infective larvae that can be transmitted to a new host individuals infected by filarial worms may be described as either microfilaraemic or amicrofilaraemic depending on whether microfilariae can be found in their peripheral blood filariasis is diagnosed in microfilaraemic cases primarily through direct observation of microfilariae in the peripheral blood occult filariasis is diagnosed in amicrofilaraemic cases based on clinical observations and in some cases by finding a circulating antigen in the blood
file spanning is the ability to package a single file or data stream into separate files of a specified size this task implies the ability to re combine the package files back into the original file or data stream this is useful when saving large files onto smaller volumes or breaking large files up into smaller files for network messages of limited size email newsgroups it also allows the creation of parity files such as parity archive par to verify and restore missing or corrupted package files another advantage with this is coping with filesize limits on some file systems of removable media or coping with volume size limits of things like floppy disks sometimes the file spanning process is hidden as a secondary operation such as with file archivers in this case many smaller files are first packaged into a data stream and then repackaged into a multi file archive
filicollosis is a parasitic disease of ducks geese and other waterbirds caused by filicollis anatis a species of acanthocephala of the polymorphidae family the disease is endemic in europe and asia
the filmography on immigration in italy is a phenomenon started with the arrival of the first migratory flows in italy since the 1990 s
in functional programming filter is a higher order function that processes a data structure usually a list in some order to produce a new data structure containing exactly those elements of the original data structure for which a given predicate returns the boolean value true
fin rot is a symptom of disease or the actual disease in fish this is a disease which is most often observed in aquaria and aquaculture but can also occur in natural populations fin rot can be the result of a bacterial infection pseudomonas fluorescens which causes a ragged rotting of the fin or as a fungal infection which rots the fin more evenly and is more likely to produce a white edge sometimes both types of infection are seen together infection is commonly brought on by bad water conditions injury poor diet stress or as a secondary infection in a fish which is already stressed by other disease fin rot starts at the edge of the fins and destroys more and more tissue until it reaches the fin base if it does reach the fin base the fish will never be able to regenerate the lost tissue at this point the disease may begin to attack the fish s body this is called advanced fin and body rot fin rot is common in bettas due to poor water conditions in pet stores
financial integration is a phenomenon in which financial markets in neighboring regional and or global economies are closely linked together various forms of actual financial integration include information sharing among financial institutions sharing of best practices among financial institutions sharing of cutting edge technologies through licensing among financial institutions firms borrow and raise funds directly in the international capital markets investors directly invest in the international capital markets newly engineered financial products are domestically innovated and originated then sold and bought in the international capital markets rapid adaption copycat of newly engineered financial products among financial institutions in different economies cross border capital flows and foreign participation in the domestic financial markets because of financial market imperfections financial integration in neighboring regional and or global economies is therefore imperfect for example the imperfect financial integration can stem from the inequality of the marginal rate of substitutions of different agents in addition to financial market imperfections legal restrictions can also hinder financial integration therefore financial integration can also be achieved from the elimination of restrictions pertaining to cross border financial operations to allow a financial institutions to operate freely b permit businesses to directly raise funds or borrow and c equity and bond investors to invest across the state line with fewer or without imposing any restrictions however it is important to note that many of the legal restrictions exist because of the market imperfections that hinder financial integration legal restrictions are sometimes second best devices for dealing with the market imperfections that limit financial integration consequently removing the legal restrictions can make the world economy become worse off in addition financial integration of neighboring regional and or global economies can take place through a formal international treaty which the governing bodies of these economies agree to cooperate to address regional and or global financial disturbances through regulatory and policy responses the extent to which financial integration is measured includes gross capital flows stocks of foreign assets and liabilities degree of co movement of stock returns degree of dispersion of world wide real interest rates and financial openness
financial literacy is the ability to understand how money works in the world how someone manages to earn or make it how that person manages it how he she invests it turn it into more and how that person donates it to help others more specifically it refers to the set of skills and knowledge that allows an individual to make informed and effective decisions with all of their financial resources raising interest in personal finance is now a focus of state run programs in countries including australia canada japan the united states and the uk the organization for economic co operation and development oecd started an inter governmental project in 2003 with the objective of providing ways to improve financial education and literacy standards through the development of common financial literacy principles in march 2008 the oecd launched the international gateway for financial education which aims to serve as a clearinghouse for financial education programs information and research worldwide in the uk the alternative term financial capability is used by the state and its agencies the financial services authority fsa in the uk started a national strategy on financial capability in 2003 the us government also established its financial literacy and education commission in 2003
the financial result is the difference between earnings before interest and taxes and earnings before taxes it is determined by the earning or the loss which results from financial affairs
finching is a colour pattern of cattle occurring in many unrelated breeds cattle with finching are said to be finched or finch backed finching consists of a white or pale stripe along the spine it may join to a white head as in hereford cattle continue over the tail as in gloucester and pinzgau cattle or it may form part of another colour sided pattern for example in lineback english longhorn texas longhorn speckle park and irish moiled cattle in some breeds such as jersey cattle and heck cattle finching occurs mainly in bulls forming a cream or white stripe along the spine of a black brown animal – this is thought to have been the colour pattern of the bulls of the wild ancestor of domesticated cattle the aurochs
finger agnosia first defined in 1924 by josef gerstmann is the loss in the ability to distinguish name or recognize the fingers not only with the patient s own fingers but also the fingers of others and drawing and other representations of fingers it is one of a tetrad of symptoms in gerstmann syndrome although it is also possible for finger agnosia to exist on its own without any other disorders usually lesions to the left angular gyrus and posterior parietal areas can lead to finger agnosia
the finkelstein reaction named after the german chemist hans finkelstein is an sn 2 reaction substitution nucleophilic bimolecular reaction that involves the exchange of one halogen atom for another halide exchange is an equilibrium reaction but the reaction can be driven to completion by exploiting the differential solubility of halide salts or by using a large excess of the halide salt r x x ′ − ⇌ r x ′ x − the classic finkelstein reaction entails the conversion of an alkyl chloride or an alkyl bromide to an alkyl iodide by treatment with a solution of sodium iodide in acetone sodium iodide is soluble in acetone and sodium chloride and sodium bromide are not the reaction is driven toward products by mass action due to the precipitation of the insoluble salt for example bromoethane can be converted to iodoethane ch 3 ch 2 br acetone nai acetone → ch 3 ch 2 i acetone nabr s alkyl halides differ greatly in the ease with which they undergo the finkelstein reaction the reaction works well for primary except for neopentyl halides and exceptionally well for allyl benzyl and α carbonyl halides secondary halides are far less reactive vinyl aryl and tertiary alkyl halides are unreactive below some relative rates of reaction nai in acetone at 60 ° in modern usage the definition of the reaction has been expanded to include the conversion of alcohols to alkyl halides by first converting the alcohol to a sulfonate ester tosylates or mesylates are usually used and then performing the substitution the example below is from a synthesis of chrysochlamic acid
a finnish heritage disease is a genetic disease or disorder that is significantly more common in people whose ancestors were ethnic finns natives of finland and sweden meänmaa and russia karelia and ingria about 40 rare diseases are regarded as finnish heritage diseases the diseases are not restricted to finns they are genetic diseases with far wider distribution in the world but due to founder effects and genetic isolation they are more common in finns within finland these diseases are more common in the east and north consistent with their higher association with ethnic finns than with ethnic swedes the finnish disease heritage does not extend to other ethnic groups in the region the sámi and karelians other than finnish karelians it is attributed to a population bottleneck among ancestors of modern finns estimated to have occurred about 4000 years ago presumably when populations practicing agriculture and animal husbandry arrived in finland in finland about one in five persons carries a gene defect associated with at least one finnish heritage disease and about one in 500 children born is affected most of the gene defects are autosomal recessives so that if both the mother and father carry the same defect the chance that their child will have the associated disease is 1 in 4 the molecular genetics of many of these diseases have been determined enabling genetic testing prenatal testing and counseling this has raised questions of bioethics and eugenics
fire blight also written fireblight is a contagious disease affecting apples pears and some other members of the family rosaceae it is a serious concern to apple and pear producers under optimal conditions it can destroy an entire orchard in a single growing season the causal pathogen is erwinia amylovora a gram negative bacterium in the family enterobacteriaceae pears are the most susceptible but apples loquat crabapples quinces hawthorn cotoneaster pyracantha raspberry and some other rosaceous plants are also vulnerable the disease is believed to be indigenous to north america from where it spread to most of the rest of the world fire blight is not believed to be present in australia though it might possibly exist there it has been a major reason for a long standing embargo on the importation of new zealand apples to australia japan was likewise believed to be without the disease but it was discovered in pears grown in northern japan japanese authorities are however still denying its existence and the japanese scientist who discovered it is believed to have committed suicide after his name was leaked to affected farmers in europe it is listed as a quarantine disease and has been spreading along hawthorn crataegus hedges planted alongside railways motorways and main roads
fire breather s pneumonia also known as fire breather s lung or fire eater s lung is a distinct type of exogenous — that is originating outside the body — lipoid pneumonia chemical pneumonitis that results from inhalation or aspiration of hydrocarbons of different types such as lamp oil accidental inhalation of hydrocarbon fuels can occur during fire breathing fire eating or other fire performance and may lead to pneumonitis symptoms can vary significantly among individuals ranging from asymptomatic to a severe life threatening disease onset usually occurs within hours though symptoms may not appear for several days lipoid pneumonia is a rare condition but is an occupational hazard of fire performers
fire prevention is a function of many fire departments the goal of fire prevention is to educate the public to take precautions to prevent potentially harmful fires and be educated about surviving them it is a proactive method of reducing emergencies and the damage caused by them many fire departments have a fire prevention officer in the general sense of preventing harmful fires many aspects are discussed in the articles fire protection and fire safety national work on best practices is in the vision 2020 program
a fire regime is the pattern frequency and intensity of the bushfires and wildfires that prevail in an area it is an integral part of fire ecology and renewal for certain types of ecosystems if fires are too frequent plants may be killed before they have matured or before they have set sufficient seed to ensure population recovery if fires are too infrequent plants may mature senesce and die without ever releasing their seed
firestop pillows are passive fire protection items used for firestopping holes in wall or floor assemblies required to have a fire resistance rating the products must be used in accordance with a valid certification listing subject to listing and approval use and compliance
a black hole firewall is a hypothetical phenomenon where an observer that falls into an old black hole encounters high energy quanta at or near the event horizon the firewall phenomenon was proposed in 2012 by ahmed almheiri donald marolf joseph polchinski and james sully as a possible solution to an apparent inconsistency in black hole complementarity the proposal is sometimes referred to as the amps firewall an acronym for the names of the authors of the 2012 paper the use of a firewall to resolve this inconsistency remains controversial as of 2013 with high energy physicists divided as to the solution to the paradox
the firing squad synchronization problem is a problem in computer science and cellular automata in which the goal is to design a cellular automaton that starting with a single active cell eventually reaches a state in which all cells are simultaneously active it was first proposed by john myhill in 1957 and published with a solution in 1962 by edward moore
first degree atrioventricular block av block or pr prolongation is a disease of the electrical conduction system of the heart in which the pr interval is lengthened beyond 0 20 seconds in first degree av block the impulse conducting from atria to ventricles through the atrioventricular node av node is delayed and travels slower than normal it has a prevalence in the normal young adult population of 0 65 1 1 and the incidence is 0 13 per 1000 persons
the first pass effect also known as first pass metabolism or presystemic metabolism is a phenomenon of drug metabolism whereby the concentration of a drug is greatly reduced before it reaches the systemic circulation it is the fraction of drug lost during the process of absorption which is generally related to the liver and gut wall notable drugs that experience a significant first pass effect are imipramine morphine propranolol buprenorphine diazepam midazolam pethidine cimetidine lidocaine and nitroglycerin after a drug is swallowed it is absorbed by the digestive system and enters the hepatic portal system it is carried through the portal vein into the liver before it reaches the rest of the body the liver metabolizes many drugs sometimes to such an extent that only a small amount of active drug emerges from the liver to the rest of the circulatory system this first pass through the liver thus greatly reduces the bioavailability of the drug the four primary systems that affect the first pass effect of a drug are the enzymes of the gastrointestinal lumen gut wall enzymes bacterial enzymes and hepatic enzymes in drug design drug candidates may have good druglikeness but fail on first pass metabolism because it is biochemically selective alternative routes of administration like suppository intravenous intramuscular inhalational aerosol transdermal and sublingual avoid the first pass effect because they allow drugs to be absorbed directly into the systemic circulation drugs with high first pass effect have a considerably higher oral dose than sublingual or parenteral dose there is marked individual variation in the oral dose due to differences in the extent of first pass metabolism oral bioavailability is apparently increased in patients with severe liver diseases like cirrhosis it is also increased if another drug competing with it in first pass metabolism given concurrently eg propranolol and chlorpromazine
fis phenomenon is a phenomenon of child language acquisition that demonstrates that perception of phonemes occurs earlier than the ability of the child to produce those phonemes it is also illustrative of a larger theme in child language acquisition that skills in linguistic comprehension generally precede corresponding skills in linguistic production the name comes from an incident reported in 1960 by j berko and r brown a child referred to his inflatable plastic fish as a fis however when adults asked him is this your fis he rejected the statement when he was asked is this your fish he responded yes my fis this shows that although the child could not produce the phoneme ʃ he could perceive it as being different from the phoneme s in some cases the sounds produced by the child are actually acoustically different but not significantly enough for others to distinguish since the language in question does not make such contrasts
fiscal sustainability or public finance sustainability is the ability of a government to sustain its current spending tax and other policies in the long run without threatening government solvency or defaulting on some of its liabilities or promised expenditures there is no consensus among economists on a precise operational definition for fiscal sustainability rather different studies use their own often similar definitions many countries and research institutes have published reports which assess the sustainability of fiscal policies based on long run projections of country s public finances see for example and these assessments attempt to determine whether an adjustment to current fiscal policies that is required to reconcile projected revenues with projected expenditures the size of the required adjustment is given with measures such as the fiscal gap
the fischer – hepp rearrangement is a rearrangement reaction in which an aromatic n nitroso or nitrosamine converts to a carbon nitroso compound fischer hepp rearrangement this organic reaction was first described by the german chemist otto philipp fischer 1852 – 1932 and eduard hepp june 11 1851 – june 18 1917 in 1886 and is of importance because para no secondary anilines cannot be prepared in a direct reaction the rearrangement reaction takes place by reacting the nitrosamine precursor with hydrochloric acid the chemical yield is generally good under these conditions but often much poorer if a different acid is used the exact reaction mechanism is unknown but there is evidence suggesting an intramolecular reaction
fish eye disease is a genetic disorder involving a deficiency in lecithin — cholesterol acyltransferase lcat metabolism while lcat metabolism in familial lcat deficiency is fully inactive patients with fish eye disease only have a partial deficiency of lcat carlson and philipson found that the disease was named so because the cornea of the eye was so opaque or cloudy with dots of cholesterol that it resembled a boiled fish the disorder is inherited in an autosomal recessive manner therefore both copies of the gene in each cell must have a mutation if an individual only carry one copy of the mutated gene they typically do not show symptoms fish eye disease is characterized by abnormalities like visual impairment plaques of fatty material and dense opacification it is uncertain if lcat deficiencies are linked to coronary artery disease
fish acute toxicity syndrome fats is a set of common chemical and functional responses in fish resulting from a short term acute exposure to a lethal concentration of a toxicant a chemical or material that can produce an unfavorable effect in a living organism by definition modes of action are characterized by fats because the combination of common responses that represent each fish acute toxicity syndrome characterize an adverse biological effect therefore toxicants that have the same mode of action elicit similar sets of responses in the organism and can be classified by the same fish acute toxicity syndrome
dropsy is the buildup of fluid inside the body cavity or tissues of a fish as a symptom rather than a disease it can indicate a number of underlying diseases including bacterial infections parasitic infections or liver dysfunction
in statistical classification the fisher kernel named after ronald fisher is a function that measures the similarity of two objects on the basis of sets of measurements for each object and a statistical model in a classification procedure the class for a new object whose real class is unknown can be estimated by minimising across classes an average of the fisher kernel distance from the new object to each known member of the given class the fisher kernel was introduced in 1998 it combines the advantages of generative statistical models like the hidden markov model and those of discriminative methods like support vector machines generative models can process data of variable length adding or removing data is well supported discriminative methods can have flexible criteria and yield better results
a fishing weir fish weir fishgarth or kiddle is an obstruction placed in tidal waters or wholly or partially across a river to direct the passage of fish a weir may be used to trap fish such as salmon as they attempt to swim upstream or eels as they migrate downstream alternatively fish weirs can be used to channel fish to a particular location such as to a fish ladder weirs were traditionally built from wood or stones the use of fishing weirs as fish traps dates back prior to the emergence of modern humans and have since been used by many societies across the world
fissure of the nipple also known as jogger s nipple is a condition that can be caused by friction that can result in soreness dryness or irritation to or bleeding of one or both nipples during or following running or other physical exercise this condition is also experienced by women who breastfeed and by surfers who do not wear rash guards
fissured tongue also known as scrotal tongue lingua plicata plicated tongue and furrowed tongue is a benign condition characterized by deep grooves fissures in the dorsum of the tongue although these grooves may look unsettling the condition is usually painless some individuals may complain of an associated burning sensation it is a relatively common condition with a prevalence of between 6 8 and 11 found amongst children the prevalence of the condition increases significantly with age occurring in 40 of the population after the age of 40
a fistula is an abnormal anastomosis that is an abnormal connection between two hollow spaces technically two epithelialized surfaces such as blood vessels intestines or other hollow organs fistulas are usually caused by injury or surgery but they can also result from an infection or inflammation fistulas are generally a disease condition but they may be surgically created for therapeutic reasons in botany the term is most common in its adjectival forms where it is used in binomial names to refer to species that are distinguished by hollow or tubular structures monarda fistulosa for example has tubular flowers eutrochium fistulosum has a tubular stem and allium fistulosum has hollow or tubular leaves
fitness culture is a sociocultural phenomenon which refers to the culture surrounding physical exercises it is usually associated with gym culture as doing physical exercises in locations such as gyms wellness centres and health clubs is a popular activity an international survey found that more than 27 of world total adult population attends fitness centres and that 61 of regular exercisers are currently doing gym type activities
fitz hugh – curtis syndrome is a rare complication of pelvic inflammatory disease pid named after the two physicians thomas fitz hugh jr and arthur hale curtis who first reported this condition in 1934 and 1930 respectively it involves liver capsule inflammation leading to the creation of adhesions
fitzsimmons – guilbert syndrome is an extremely rare genetic disease characterized by a slowly progressive spastic paraplegia skeletal anomalies of the hands and feet with brachydactyly type e cone shaped epiphyses abnormal metaphyseal – phalangeal pattern profile sternal anomaly pectus carinatum or excavatum dysarthria and mild intellectual deficit
fixed drug reactions are common and so named because they recur at the same site with each exposure to a particular medication medications inducing fixed drug eruptions are usually those taken intermittently drugs causing fixed drug eruptions 1 fluconazole 2 ciprofloxacin 3 doxycycline 4 clarithromycin 5 nsaids 6 trimethoprim 7 cotrimoxazole 8 phenytoin 9 cetirizine 10 pseudoephedrine
flaccid dysarthria is a motor speech disorder resulting from damage to peripheral nervous system cranial or spinal nerves or lower motor neuron system the damage affects the respiratory phonatory resonatory and articulatory components of speech and causes weakness hypotonia and diminished reflexes causes flaccid dysarthria is caused when damage occurs to the motor unit one or more cranial or spinal nerves processes that can cause this include congenital disorders demyelinating disorders infectious inflammatory degenerative disorders metabolic neoplastic traumatic vascular diseases flaccid paralysis
flaccid paralysis ˈflæksɪd pəˈræləsɪs is a clinical manifestation characterized by weakness or paralysis and reduced muscle tone without other obvious cause e g trauma this abnormal condition may be caused by disease or by trauma affecting the nerves associated with the involved muscles for example if the somatic nerves to a skeletal muscle are severed then the muscle will exhibit flaccid paralysis when muscles enter this state they become limp and cannot contract this condition can become fatal if it affects the respiratory muscles posing the threat of suffocation
flacherie literally flaccidness is a disease of silkworms caused by silkworms eating infected or contaminated mulberry leaves flacherie infected silkworms look weak and can die from this disease silkworm larvae that are about to die from flacherie are a dark brown there are two kinds of flacherie essentially infectious viral flacherie and noninfectious touffee flacherie both are technically a lethal diarrhea bouffée flacherie is caused by heat waves bouffée means sudden heat spell in french viral flacherie is ultimately caused by infection with bombyx mori infectious flacherie virus bmifv iflaviridae bombyx mori densovirus bmdnv parvoviridae or bombyx mori cypovirus 1 bmcpv 1 reoviridae this either alone or in combination with bacterial infection destroys the gut tissue bacterial pathogens contributing to infectious flaccherie are serratia marcescens and species of streptococcus and staphylococcus in the form known as thatte roga louis pasteur who began his studies on silkworm diseases in 1865 was the first one able to recognize that mortality due to viral flacherie was caused by infection priority however was claimed by antoine béchamp richard gordon described the discovery the french silk industry was meanwhile plummeting from a 130 million to an 8 million francs annual income because the silkworms had all caught pébrine black pepper disease … he pasteur went south from paris to alais and rewarded them by discovering the silkworm epidemic to be inflicted by some sort of living microbe … pasteur threw in another disease flâcherie silkworm diarrhoea the cures for both were culling the insects which showed the peppery spots — the peasants bottled the silkworm moths in brandy for display to the experts — and rigorous hygiene of the mulberry leaf
flail chest is a life threatening medical condition that occurs when a segment of the rib cage breaks due to trauma and becomes detached from the rest of the chest wall two of the symptoms of flail chest are chest pain and shortness of breath it occurs when multiple adjacent ribs are broken in multiple places separating a segment so a part of the chest wall moves independently the number of ribs that must be broken varies by differing definitions some sources say at least two adjacent ribs are broken in at least two places some require three or more ribs in two or more places the flail segment moves in the opposite direction to the rest of the chest wall because of the ambient pressure in comparison to the pressure inside the lungs it goes in while the rest of the chest is moving out and vice versa this so called paradoxical breathing is painful and increases the work involved in breathing flail chest is usually accompanied by a pulmonary contusion a bruise of the lung tissue that can interfere with blood oxygenation often it is the contusion not the flail segment that is the main cause of respiratory problems in people with both injuries surgery to fix the fractures appears to result in better outcomes
flame cutting is a destructive phenomenon that occurs in some firearms usually revolvers as a result of hot gases under high pressure the most common manifestation is on the underside of a revolver top strap where the hot high velocity gases released when a round is fired begin to cut through just above and in front of the cylinder in most cases this is self limiting eventually the depth of the cut will place the undamaged material far enough away that the heat and pressure of the gas will have dissipated to harmless levels this limiting tends to occur before structural integrity is compromised
flame lift off in oil fired pressure jet burners is an unwanted condition in which the flame and burner become separated this condition is most commonly created by excessive combustion air and often results in the loss of flame as the photo electric cell fails to register the light of the flame this in turn results in a safety lockout of the control box
flame rectification is a phenomenon in which a flame can act as an electrical rectifier the effect is commonly described as being caused by the greater mobility of electrons relative to that of positive ions within the flame and the asymmetric nature of the electrodes used to detect the phenomenon this effect is used by rectification flame sensors to detect the presence of flame the rectifying effect of the flame on an ac voltage allows the presence of flame to be distinguished from a resistive leakage path one experimental study has suggested that the effect is caused by the ionization process occurring mostly at the base of the flame making it more difficult for the electrode further from the base of the flame to attract positive ions from the burner yet leaving the electron current largely unchanged with distance because of the greater mobility of the electron charge carriers
flammability is the ability of a substance to burn or ignite causing fire or combustion the degree of difficulty required to cause the combustion of a substance is quantified through fire testing internationally a variety of test protocols exist to quantify flammability the ratings achieved are used in building codes insurance requirements fire codes and other regulations governing the use of building materials as well as the storage and handling of highly flammable substances inside and outside of structures and in surface and air transportation for instance changing an occupancy by altering the flammability of the contents requires the owner of a building to apply for a building permit to make sure that the overall fire protection design basis of the facility can take the change into account
flanging ˈflændʒɪŋ is an audio effect produced by mixing two identical signals together one signal delayed by a small and gradually changing period usually smaller than 20 milliseconds this produces a swept comb filter effect peaks and notches are produced in the resulting frequency spectrum related to each other in a linear harmonic series varying the time delay causes these to sweep up and down the frequency spectrum a flanger is an effects unit that creates this effect in some cases the two signals will become so close that it almost fades away to oblivion called sucking air it has also been called the darth vader effect part of the output signal is usually fed back to the input a re circulating delay line producing a resonance effect which further enhances the intensity of the peaks and troughs the phase of the fed back signal is sometimes inverted producing another variation on the flanging sound
flap back or blowback is a phenomenon affecting the rotor of a helicopter as it overcomes dissymmetry of lift through flapping in forward flight rotor blades experience more lift as they rotate forward this increased lift is a result of an increased relative speed causing the blade to flap up and decrease its angle of attack as the blade continues to rotate it achieves its maximum upflapping displacement over the nose of the aircraft and maximum downflapping displacement over the tail this results in the rotor disk being tilted to the rear and is referred to as flap back as if the rotor disk had flapped or tilted back or as if it had been blown back by the relative wind the effect is more pronounced at higher airspeeds but more easily recognized as the aircraft accelerates to translational lift airspeeds from a hover flap back results in a slowing of the aircraft and the pilot counters the effect by applying forward input to the cyclic control
flaser beds are a sedimentary bi directional bedding pattern created when a sediment is exposed to intermittent flows leading to alternating sand and mud layers while flaser beds typically form in tidal environments they can rarely form in fluvial conditions on point bars or in ephemeral streams individual sand ripples are created which are later infilled by mud during quieter flow periods these mud drapes are typically a minor constituent of the deposit they can consolidate within three hours protecting the underlying layer from erosion flaser bedding typically forms in high energy environments
flash blindness is visual impairment during and following exposure to a light flash of extremely high intensity it may last for a few seconds to a few minutes for example in everyday life the subject of a flash photograph can be temporarily flash blinded the bright light overwhelms the eye and only gradually fades a bright spot or spots may be seen for many minutes this phenomenon is leveraged in non lethal weapons such as flash grenades and laser dazzlers
flash burn is any burn injury caused by intense flashes of light high voltage electric current or strong thermal radiation these may originate from for example a sufficiently large bleve a thermobaric weapon explosion or a nuclear blast of sufficient magnitude damage to the eye s caused by ultraviolet rays is known as photokeratitis
flash suppression is a phenomenon of visual perception in which an image presented to one eye is suppressed by a flash of another image presented to the other eye to observe flash suppression a small image is first presented to one eye for about a second while a blank field is presented to the other eye then a different small image is abruptly shown flashed to the other second eye at the location corresponding to the image to the first eye the image to the first eye disappears even though it is still presented and only the new image is perceived the new image to the second eye suppresses perception of the image to the first for example if a vehicle is shown to the left eye for 1 second and then a face is abruptly flashed to the right eye the observer consciously sees first a vehicle and then a face note that the face is seen while the picture of the car is still present if the order of presentation is reversed the order of percept is reversed the phenomenon of flash suppression seemed to have been known since the 19 th century the phenomena was described by mcdougall in 1901 p 598 and utilized for an eeg experiment by lansing in 1964 in 1984 jeremy wolfe characterized flash suppression in a systematic psychophysics study flash suppression is an example of perceptual illusions that render a highly visible image invisible and that are used to study the mechanisms of conscious and non conscious visual processing koch 2004 related perceptual illusions include backward masking binocular rivalry motion induced blindness and motion induced interocular suppression the brain basis of flash suppression has been studied using microelectrode recordings in the visual brain of the macaque monkey logothetis 1998 and in the human medial temporal lobe kreiman koch fried 2002
a flashback or involuntary recurrent memory is a psychological phenomenon in which an individual has a sudden usually powerful re experiencing of a past experience or elements of a past experience these experiences can be happy sad exciting or any other emotion one can consider the term is used particularly when the memory is recalled involuntarily and or when it is so intense that the person relives the experience unable to fully recognize it as memory and not something that is happening in real time
flat chested kitten syndrome fcks is a disorder in cats wherein kittens develop a compression of the thorax chest ribcage caused by vertebral malformation in mild cases the underside of the chest becomes flattened hence the name of the condition in extreme cases the entire thorax is flattened looking as if the kitten has been stepped on the kitten will appear to go from normal to flat in the space of about 2 – 3 hours and will usually then stabilise fcks is most frequently caused by collapsed lungs and not as formerly believed by a muscle spasm in the intercostal muscles there are numerous causes for lung collapse and therefore numerous causes for fcks one possible cause for flat chestedness that develops soon after birth is atelectasis causes of atelectasis include insufficient attempts at respiration by the newborn bronchial obstruction or absence of surfactant a substance secreted by alveoli that coats the lungs and prevents the surfaces from sticking together lack of surfactant reduces the surface area available for effective gas exchange causing lung collapse if severe there can be many reasons for atelectasis in kittens but probably the commonest cause is prematurity newborn atelectasis would not be unusual in a very large litter of kittens such as 10 where the size of the litter may lead all the kittens to be small and mildly underdeveloped unlike human babies kittens are born very immature blind deaf the intestinal tract not fully developed etc so even slight prematurity may tip them over the edge from being viable to non viable many fcks kittens may have fallen just the wrong side of this boundary in their development at the time of birth further if a kitten does not scream or open its lungs well enough at birth even if it is fully mature and has sufficient surfactant it may end up with atelectasis patches of atelectasis in the lungs mean that part of a lung is not operating properly if the kitten goes to sleep and its respiratory rate drops the patches of atelectasis can slowly expand until large areas of the lung collapse and cannot be reinflated good advice to any breeder therefore would be to ensure that kittens cry loudly when they are born to make sure that the airways are clear but also that the lungs expand as fully as possible this was the reason newborn babies were always held upside down immediately after birth so that any residual fluid drains downwards and smacked to make them cry strongly some kittens suffer from congenital secondary atelectasis which presents shortly after birth there have been no reports of kittens born flat primary atelectasis hyaline membrane disease is a type of respiratory distress syndrome of the newborn in which there is formation of a hyaline like membrane lining the terminal respiratory passages and this may also be a rarer cause of fcks pressure from outside the lung from fluid or air can cause atelectasis as well as obstruction of lung air passages by mucus resulting from various infections and lung diseases – which may explain the development of fcks in older kittens e g 10 days old who are not strong enough to breathe through even a light mucus or who may have inhaled milk during suckling tumors and inhaled objects possible if bedding contains loose fluff can also cause obstruction or irritation of the airway leading to lung collapse and secondary atelectasis in an older cat the intercostal muscles are so well developed and the ribs rigid enough that the ribcage will not flatten if the lung collapses in kittens the bones are much more flexible and the tendons and muscles more flaccid allowing movement of the thorax into abnormal positions other causes of lung collapse can include diaphragmatic hernia or diaphragmatic spasm breeders report the position of the gut and thorax as appearing to be like a stalled hiccup diaphragmatic spasm is easily checked by pinching the phrenic nerve in the neck between the fingertips kittens with this type of fcks will improve almost immediately but may require repeated pinching to prevent the spasm from recurring
flat feet also called pes planus or fallen arches is a postural deformity in which the arches of the foot collapse with the entire sole of the foot coming into complete or near complete contact with the ground some individuals an estimated 20 – 30 of the general population have an arch that simply never develops in one foot unilaterally or both feet bilaterally there is a functional relationship between the structure of the arch of the foot and the biomechanics of the lower leg the arch provides an elastic springy connection between the forefoot and the hind foot this association safeguards so that a majority of the forces incurred during weight bearing of the foot can be dissipated before the force reaches the long bones of the leg and thigh in pes planus the head of the talus bone is displaced medially and distal from the navicular as a result the spring ligament and the tendon of the tibialis posterior muscle are stretched so much so that the individual with pes planus loses the function of the medial longitudinal arch mla if the mla is absent or nonfunctional in both the seated and standing positions the individual has “ rigid ” flatfoot if the mla is present and functional while the individual is sitting or standing up on their toes but this arch disappears when assuming a foot flat stance the individual has “ supple ” flatfoot this latter condition can be correctable with well fitting arch supports three studies see citations below in military section of military recruits have shown no evidence of later increased injury or foot problems due to flat feet in a population of people who reach military service age without prior foot problems however these studies cannot be used to judge possible future damage from this condition when diagnosed at younger ages they also cannot be applied to persons whose flat feet are associated with foot symptoms or certain symptoms in other parts of the body such as the leg or back possibly referable to the foot
in manufacturing and mechanical engineering flatness is an important geometric condition for workpieces and tools in the manufacture of precision parts and assemblies especially where parts will be required to be connected across a surface area in an air tight or liquid tight manner flatness is a critical quality of the manufactured surfaces such surfaces are usually machined or ground to achieve the required degree of flatness high definition metrology such as digital holographic interferometry of such a surface to confirm and ensure that the required degree of flatness has been achieved is a key step in such manufacturing processes flatness may be defined in terms of least squares fit to a plane statistical flatness worst case or overall flatness the distance between the two closest parallel planes within two parts that are flat to about 1 helium light band hlb can be wrung together which means they will cling to each other when placed in contact this phenomenon is commonly used with gage blocks geometric dimensioning and tolerancing has provided geometrically defined quantitative ways of defining flatness operationally
the flatness problem also known as the oldness problem is a cosmological fine tuning problem within the big bang model of the universe such problems arise from the observation that some of the initial conditions of the universe appear to be fine tuned to very special values and that small deviations from these values would have extreme effects on the appearance of the universe at the current time in the case of the flatness problem the parameter which appears fine tuned is the density of matter and energy in the universe this value affects the curvature of space time with a very specific critical value being required for a flat universe the current density of the universe is observed to be very close to this critical value since the total density departs rapidly from the critical value over cosmic time the early universe must have had a density even closer to the critical density departing from it by one part in 1062 or less this leads cosmologists to question how the initial density came to be so closely fine tuned to this special value the problem was first mentioned by robert dicke in 1969 the most commonly accepted solution among cosmologists is cosmic inflation the idea that the universe went through a brief period of extremely rapid expansion in the first fraction of a second after the big bang along with the monopole problem and the horizon problem the flatness problem is one of the three primary motivations for inflationary theory
flavescence dorée from french flavescence yellowing and dorée golden is a bacterial disease of the vine with the potential to threaten vineyards the bacterial agent has recently been named candidatus phytoplasma vitis and its vector is the leafhopper scaphoideus titanus infection may kill young vines and greatly reduce the productivity of old vines it is classified as a phytoplasma disease belonging to the group generically termed grapevine yellows occurrences are in sporadic epidemics and varieties vary in their sensitivity to it there is no cure for the moment and the way to manage its spread is by uprooting of infected plants
flea borne spotted fever is a condition characterized by a rash of maculopapules or furuncles it is caused by rickettsia felis
the diagnosis of flea allergy dermatitis is complicated by the grooming habits of pets cats in particular are very efficient at grooming out fleas often removing any evidence of infestation fleas begin biting within 5 minutes of finding a host and there are no flea treatments that kill fleas before biting occurs pets that develop fad have an allergic response to flea saliva injected during flea feeding the itch associated with just one flea bite persists long after that flea is gone and leads to significant self trauma the approach with a flea allergic pet is to reduce flea numbers in the environment and on the affected pet environmental flea control includes using flea foggers or bombs vacuuming and treating pet bedding by washing on a hot cycle over 60 degrees celsius in the washing machine the current on pet treatment recommended by veterinary dermatologists is spinosad comfortis monthly and nitenpyram capstar or generics every 48 hours until improvement in some cases secondary bacterial or yeast infections will also need treatment before the itching subsides many pets who have fad may also have other allergies such as allergies to food contact allergies and atopic dermatitis
fleischer s syndrome is an extremely rare congenital anomaly characterized by displacement of the nipples occasional polymastia and hypoplasia of both kidneys
fleischer rings are pigmented rings in the peripheral cornea resulting from iron deposition in basal epithelial cells in the form of hemosiderin they are usually yellowish to dark brown and may be complete or broken they are named for bruno fleischer fleischer rings are indicative of keratoconus a degenerative corneal condition that causes the cornea to thin and change to a conic shape
flemish immigration to wallonia was an important phenomenon in the history of belgium kas deprez wrote flanders was poor and backward in the 19 th century it hardly took part in the first industrial revolution flemings migrated to wallonia amongst other areas to escape from the poverty at home yves quairiaux published the figures of the census from 1866 to 1910 which allow to understand the importance of this phenomenon
flesh fly is a popular fly pattern used by rainbow trout anglers in western alaska this particular fly fishing pattern is designed to mimic a chunk of rotten salmon flesh washing down stream the pattern is usually tied using white or off white rabbit hair
flexible product development is the ability to make changes in the product being developed or in how it is developed even relatively late in development without being too disruptive consequently the later one can make changes the more flexible the process is the less disruptive the change is the greater the flexibility flexibility is important because the development of a new product naturally involves change from what came before it change can be expected in what the customer wants and how the customer might use the product in how competitors might respond and in the new technologies being applied in the product or in its manufacturing process the more innovative a new product is the more likely it is that the development team will have to make changes during development flexible development counteracts the tendencies of many contemporary management approaches to plan a project completely at its outset and discourage change thereafter these include six sigma which aims to drive variation out of a process lean which acts to drive out waste and traditional project management and phased development systems including the popular phase – gate model which encourage upfront planning and following the plan although these methodologies have strengths their side effect is encouraging rigidity in a process that needs flexibility to be effective especially for truly innovative products for more mature product categories flexibility techniques are not only overly expensive but often unwise consequently flexibility techniques must be used with discretion for instance only in the portions of a product likely to undergo change when applied to the development of software products these methods are commonly known as agile software development however agile software methods generally rely on special characteristics of the software medium especially object technologies which are not available to non software products consequently flexible product development draws from some of the roots of agile software development but tends to use other tools and approaches that apply beyond the software medium flexible development uses several techniques to keep the cost of change low and to make decisions at the last responsible moment these techniques include modular architectures to encapsulate change experimentation and iteration to sample results and check them out with the customer frequently set based design to build and maintain options and emergent processes that develop during a project in response to its needs
a flexion teardrop fracture is a fracture of the anteroinferior aspect of a cervical vertebral body due to flexion of the spine along with vertical axial compression a teardrop fracture is usually associated with a spinal cord injury often a result of displacement of the posterior portion of the vertebral body into the spinal canal
a flight to liquidity is a financial market phenomenon occurring when investors sell what they perceive to be less liquid or higher risk investments and purchase more liquid investments instead such as us treasuries usually flight to liquidity quickly results in panic leading to a crisis for example after the russian government defaulted on its government bonds gkos in 1998 many investors sold european and japanese government bonds and purchased on the run us treasuries instead the most recently issued treasuries known as “ on the run ” have larger trading volumes that is more liquidity than treasury issues that have been superseded known as “ off the run ” this widened the spread between off the run and on the run us treasuries which ultimately led to the 1998 collapse of the long term capital management hedge fund
a flight to quality is a financial market phenomenon occurring when investors sell what they perceive to be higher risk investments and purchase safer investments such as us treasuries or gold this is considered a sign of fear in the marketplace as investors seek less risk in exchange for lower profits flight to quality is usually accompanied by an increase in demand for assets that are government backed and a decline in demand for assets backed by private agents
the flight endurance record is the longest amount of time an aircraft of a particular category spent in flight without landing it can be a solo event or multiple people can take turns piloting the aircraft as long as all pilots remain in the aircraft the limit initially was the amount of fuel that could be stored for the flight but aerial refueling extended that parameter due to safety concerns the fédération aéronautique internationale fai no longer recognizes new records for the duration of manned airplane or glider flights and has never recognized any duration records for helicopters
in aviation and aviation meteorology a flight level fl is defined as a vertical altitude at standard pressure nominally expressed in hundreds of feet the pressure is computed assuming an international standard sea level pressure datum of 1013 25 hpa 29 92 inhg and therefore is not necessarily the same as the aircraft s actual altitude either above mean sea level or above ground level
flinch was a vertigo comics horror anthology it ran 16 issues from june 1999 until january 2001 and featured the talents of jim lee bill willingham frank quitely and many others rumors of being canceled seemed to plague the book throughout its printing tim truman said of the series the best art i ve done in any single comics story is on the brer hoodoo short story i did with joe for vertigo s flinch anthology issue 11 won a horror writers association bram stoker award for red romance by joe r lansdale
flinders island spotted fever is a condition characterized by a rash in approximately 85 of cases it is associated with rickettsia honei
flint fields german feuersteinfelder are large natural deposits of flint they are found in numerous jurassic and cretaceous beds across the whole of europe such deposits may be found in aachen lousberg kleinkems schernfeld osterberg bei pfünz baiersdorf abensberg arnhofen and lengfeld as well as the german island of rügen
a flip page effect is a software gui effect that visually shows a representation of a newspaper book or leaflet as virtual paper pages that can be turned manually this effect was originally introduced as a flipping book effect in macromedia flash applications in the late 1990 s but has been evolving rapidly ever since flash applications or shockwave flash files have the swf file extension which is commonly pronounced swif hence the alternate name swiflet using the swif and the let from leaf booklet in combination flip page effects can be used both online and offline and are usually created automatically from text files such as microsoft word documents or adobe pdf format there are many solutions that help create flip page effects automatically some offer only the online version of the effects such as 3 d issue issuu and epageview and epaperflip or both versions online and offline such as pressmo and flippingbook
in project management float or slack is the amount of time that a task in a project network can be delayed without causing a delay to subsequent tasks free float project completion date total float total float is associated with the path if a project network chart diagram has 4 non critical paths then that project would have 4 total float values the total float of a path is the combined free float values of all activities in a path the total float represents the schedule flexibility and can also be measured by subtracting early start dates from late start dates of path completion float is core to critical path method with the total floats of noncritical activities key to computing the critical path drag of an activity i e the amount of time it is adding to the project s duration
floaters are deposits of various size shape consistency refractive index and motility within the eye s vitreous humour which is normally transparent at a young age the vitreous istransparent but as one ages imperfections gradually develop the common type of floater which is present in most persons eyes is due to degenerative changes of the vitreous humour the perception of floaters is known as myodesopsia or less commonly as myodaeopsia myiodeopsia or myiodesopsia they are also called muscae volitantes latin flying flies or mouches volantes from the french floaters are visible because of the shadows they cast on the retina or refraction of the light that passes through them and can appear alone or together with several others in one s visual field they may appear as spots threads or fragments of cobwebs which float slowly before the observer s eyes as these objects exist within the eye itself they are not optical illusions but are entoptic phenomena they are not to be confused with visual snow although these two conditions may co exist
the floating body effect is the effect of dependence of the body potential of a transistor realized by the silicon on insulator soi technology on the history of its biasing and the carrier recombination processes the transistor s body forms a capacitor against the insulated substrate the charge accumulates on this capacitor and may cause adverse effects for example opening of parasitic transistors in the structure and causing off state leakages resulting in higher current consumption and in case of dram in loss of information from the memory cells it also causes the history effect the dependence of the threshold voltage of the transistor on its previous states in analog devices the floating body effect is known as the kink effect one countermeasure to floating body effect involves use of fully depleted devices the insulator layer in fd devices is significantly thinner than the channel depletion width the charge and thus also the body potential of the transistors is therefore fixed however the short channel effect is worsened in the fd devices the body may still charge up if both source and drain are high and the architecture is unsuitable for some analog devices that require contact with the body hybrid trench isolation is another approach while floating body effect presents a problem in soi dram chips it is exploited as the underlying principle for z ram and t ram technologies for this reason the effect is sometimes called the cinderella effect in the context of these technologies because it transforms a disadvantage into an advantage amd and hynix licensed z ram but as of 2008 had not put it into production another similar technology and z ram competitor developed at toshiba and refined at intel is floating body cell fbc
the floating match on card is a classic close up magic effect
floating – harbor syndrome also known as pelletier – leisti syndrome is a rare disease with fewer than 50 cases described in the literature it is usually diagnosed in early childhood and is characterized by the triad of proportionate short stature with delayed bone age characteristic facial appearance and delayed speech development although its cause is unknown it is thought to result from genetic mutation and diagnosis is established by the presence of a heterozygous srcap mutation in those with clinical findings of fhs
flock worker s lung is an occupational lung disease caused by exposure to flock small fibers that are glued to a backing in order to create a specific texture people who work in flocking are at risk of inhaling the small fibers which causes interstitial lung disease the disease was initially described in 1998 when a group of workers at a flocking plant developed interstitial lung disease of unknown etiology
a floor limit is the amount of money above which credit card transactions must be authorized the limit can vary from store to store floor limits have become less significant as credit cards started being processed electronically and all transactions are typically authorized
a floor loan refers to the minimum amount of money that a lender is willing to lend in order to enable the builder to begin the construction of a building that is to be occupied by tenants the term is thus closely associated with mortgage and property loans the rest of the loan s balance is given to the builder upon the achievement of certain milestones related to the sale or lease of its residential space for example a bank may advance 80 of the balance of a property loan to the builder and release the remaining 20 upon the successful construction lease or sale of the building s residential units
floppy eyelid syndrome is a disease whose most prominent features often include floppy upper eyelids that can be easily everted as well as papillary conjunctivitis it is often associated with patients with high body mass index and obstructive sleep apnea floppy eyelid syndrome is thought to revolve around the upregulation of elastin degrading enzymes as well as mechanical factors these can cause instability of the eyelid scaffold resulting in the malposition of the eyelid
floppy trunk syndrome abbreviated fts also known as flaccid trunk paralysis is a condition that causes trunk paralysis in african bush elephants initially observed in 1989 the syndrome primarily affected bull elephants in several select regions in zimbabwe afflicted elephants exhibit paralysis in their trunk often having to adapt to feed the loss of their trunks prehensile abilities results in malnutrition and possibly death the condition is a result of degeneration of nerves in the trunk and is suggested to be a result of either heavy metals or toxins there is debate over whether the condition is reversible
florid cutaneous papillomatosis also known as the schwartz burgess syndrome is an obligate paraneoplastic syndrome fcp begins as the sudden onset of numerous cutaneous papillomas that are clinically indistinguishable from viral warts the papillomas range from 1 to 3 mm in diameter may spread to involve the entire body including the face pruritus which may sometimes precede the onset of fcp is evident in the affected regions in about half of patients evaluation of a skin biopsy clearly distinguishes fcp from viral warts fcp is associated with underlying cancer of the breast bladder ovary uterus prostate and lung other associated underlying malignancies include squamous cell carcinomas and lymphomas such as non hodgkin s lymphoma fcp is sometimes seen together with other signs of internal cancer especially malignant acanthosis nigricans tripe palms leser – trélat sign and hypertrichosis lanuginosa acquisita fcp tends to improve in association with surgical or chemotherapeutic therapy of the underlying internal cancer a recurrence or exacerbation of fcp may be linked with tumor regrowth or metastatic spread
florida keratopathy florida spots is an eye condition characterized by the presence of multiple spots within both corneas it is most commonly seen in dogs and cats but is also rarely seen in horses and birds in the united states florida keratopathy is found in animals in the southeastern part of the country in other parts of the world it is confined to tropics and subtropics and it is known as tropical keratopathy florida keratopathy appears as multiple cloudy opacities in the stromal layer of the cornea the spots appear concentrated at the center and become more diffuse at the periphery they can range in size from one to eight millimeters there are no other symptoms and there is no response to treatment with either anti inflammatory or antimicrobial drugs histological analysis of affected corneas has found acid fast staining organisms suggesting florida keratopathy may be caused by a type of mycobacterium there is a strong suspicion that it is induced by repeated stings of wasmannia auropunctata to the eyes the little fire ant an invasive species
flotation of flexible objects is a phenomenon in which the bending of a flexible material allows an object to displace a greater amount of fluid than if it were completely rigid this ability to displace more fluid translates directly into an ability to support greater loads giving the flexible structure an advantage over a similarly rigid one inspiration to study the effects of elasticity are taken from nature where plants and animals living at the water surface have evolved to take advantage of the load bearing benefits elasticity imparts
flow shop scheduling problems are a class of scheduling problems with a workshop or group shop in which the flow control shall enable an appropriate sequencing for each job and for processing on a set of machines or with other resources 1 2 m in compliance with given processing orders especially the maintaining of a continuous flow of processing tasks is desired with a minimum of idle time and a minimum of waiting time flow shop scheduling is a special case of job shop scheduling where there is strict order of all operations to be performed on all jobs flow shop scheduling may apply as well to production facilities as to computing designs a special type of flow shop scheduling problem is the permutation flow shop scheduling problem in which the processing order of the jobs on the resources is the same for each subsequent step of processing
the flowering desert spanish desierto florido is a climatic phenomenon that occurs in the atacama desert chile the phenomenon consists of the blossoming of a wide variety of flowers between the months of september and november in years when rainfall is unusually high normally the region receives less than 12 mm 0 47 in of rain a year the blossoming occurs when the unusual level of rainfall reach the seeds and bulbs that have been in a latent or dormant state and causes them to germinate and flower in early spring it is accompanied by the proliferation of insects birds and small species of lizard at its height the phenomenon can be seen from just south of the city of vallenar to just north of the city of copiapó throughout the coastal valleys and chilean coast range from september to november climatically the event is related to the el niño phenomenon a band of anomalously warm ocean water temperatures that occasionally develops off the western coast of south america which can lead to an increase in evaporation and therefore precipitation the flowering desert is a popular tourist attraction with tourists visiting the phenomenon from various points around the southern atacama including huasco vallenar la serena copiapó and caldera
in united states federal milk marketing orders the fluid differential or class i differential is the amount added to the base price of milk to determine a region ’ s minimum price for milk used for fluid drinking purposes
fluid pipes are a phenomenon driven by surface tension when a pure water jet impinges on a reservoir capillary waves are excited and propagate up the jet at the same speed that the jet falls
fluorescence anisotropy is the phenomenon where the light emitted by a fluorophore has unequal intensities along different axes of polarization early pioneers in the field include aleksander jablonski gregorio weber and andreas albrecht the principles of fluorescence polarization and some applications of the method are presented in lakowicz s book
fluorescence intermittency or blinking is the phenomenon of random switching between on bright and off dark states of the emitter under its continuous excitation it is a common property of the nanoscale emitters molecular fluorophores colloidal quantum dots related to the competition between the radiative and non radiative relaxation pathways the peculiar feature of such blinking in most cases is the power law in contrast to exponential statistics of the on and off time distributions meaning that the measurements of the time averaged intensity of a single emitter is not reproducible in different experiments and implying a complex dynamics of the involved process in other words in one experiment the emitter can blink frequently while in another it may stay on or off for almost entire length of the experiment even for extremely long measurement times
blinking colloidal nanocrystals is a phenomenon observed during studies of single colloidal nanocrystals that show that they randomly turn their photoluminescence on and off even under continuous light illumination this has also been described as luminescence intermittency similar behavior has been observed in crystals made of other materials for example porous silicon also exhibits this affect
although safe and good for dental health at low concentrations sustained consumption of large amounts of soluble fluoride salts is dangerous referring to a common salt of fluoride sodium fluoride naf the lethal dose for most adult humans is estimated at 5 to 10 g which is equivalent to 32 to 64 mg kg elemental fluoride kg body weight ingestion of fluoride can produce gastrointestinal discomfort at doses at least 15 to 20 times lower 0 2 – 0 3 mg kg or 10 to 15 mg for a 50 kg person than lethal doses although helpful for dental health in low dosage chronic exposure to fluoride in large amounts interferes with bone formation in this way the most widespread examples of fluoride poisoning arise from consumption of ground water that is abnormally fluoride rich
fluorination with aminosulfuranes is a chemical reaction that transforms oxidized organic compounds into organofluorine compounds aminosulfuranes selectively exchange hydroxyl groups for fluorine but are also capable of converting carbonyl groups halides silyl ethers and other functionality into organofluorides
fluoride or fluorine deficiency is a disorder which may cause increased dental caries or tooth decay is the breakdown of dental tissues by the acidic products released by the bacterial fermentation of dietary carbohydrates and possibly osteoporosis a bone disorder which leads to a decrease in bone mass and an increase in bone fragility due to a lack of fluoride in the diet however there are anti osteoporotic functional food ingredients that can help decrease the risk of osteoporosis fractures in terms of dietary sources fish and tea are considered natural sources of fluoride as well as tap water that has been fluoridated the extent to which the condition truly exists and its relationship to fluoride poisoning has given rise to some controversy fluorine is not considered to be an essential nutrient but the importance of fluorides for preventing tooth decay is well recognized although the effect is predominantly topical prior to 1981 the effect of fluorides was thought to be largely systemic and preeruptive requiring ingestion fluoride is considered essential in the development and maintenance of teeth by the american dental hygienists association fluoride is also essential as it incorporates into the teeth to form and harden teeth enamels so that the teeth are more acid resistant as well as more resistant to cavity forming bacteria caries inhibiting effects of fluoride were first seen in 1902 when fluoride in high concentrations was found to stain teeth and prevent tooth decay fluoride salts particularly sodium fluoride naf are used in the treatment and prevention of osteoporosis symptoms such as fractured hips in the elderly or brittle and weak bones are caused due to fluorine deficiency in the body fluoride stimulates bone formation and increases bone density however bone with excess fluoride content has an abnormal structure resulting in increased fragility thus fluoride therapy results in large increases in bone mineral density but the effect on fracture rates while positive is small disputes over the essentiality of fluorine date back to the 19 th century when fluorine was observed in teeth and bones in 1973 a trial found reduced reproduction in mice fed fluorine deficient diets but a subsequent investigation determined that this was due to reduced iron absorption
fluosol is an artificial blood which is milky in color its main ingredients are perfluorodecalin or perfluorotributylamine in fluosol da and fluosol 43 respectively perfluorochemicals suspended in an albumin emulsion it was developed in japan and first tested in the united states in nov 1979 its recipients being individuals who refused blood transfusions on religious grounds fluosol serves as a dissolving medium for oxygen in order to load sufficient amounts of oxygen into it patients must breathe pure oxygen by mask or must be in a hyperbaric chamber while initially promising for therapy of heart attack carbon monoxide poisoning and sickle cell anemia research also indicates that fluosol may depress the patient s immune system given its low viscosity it could be used in cases of stenosis fluosol is the only blood substitute approved to date by the u s food and drug administration fda for medical use in the circulatory system new drug application n 860909 1989 the fda and eight other countries approved fluosol not for the use of reducing the amount of allogenic blood units transfused but for use during cardiac angioplasty this procedure was noted to reduce the mycoardial oxygenation leading to st segment elevation on ecgs angina and reduced ejection fraction use of fluosol reduced these symptoms and allowed for longer cardiac antiplasty times from 1989 to 1992 fluosol was used in more than 40 000 human subjects due to difficulty with the emulsion storage of fluosol use frozen storage and rewarming its popularity declined and its production ended fluosol is associated with a reduction in ischemic complications and with an increase in pulmonary edema and congestive heart failure
flux pinning is the phenomenon where a superconductor is pinned in space above a magnet the superconductor must be a type ii superconductor because type i superconductors cannot be penetrated by magnetic fields the act of magnetic penetration is what makes flux pinning possible at higher magnetic fields above hc 1 and below hc 2 the superconductor allows magnetic flux to enter in quantized packets surrounded by a superconducting current vortex see quantum vortex these sites of penetration are known as flux tubes the number of flux tubes per unit area is proportional to the magnetic field with a constant of proportionality equal to the magnetic flux quantum on a simple 76 millimeter diameter 1 micrometer thick disk next to a magnetic field of 350 oe there are approximately 100 billion flux tubes that hold 70 000 times the superconductor s weight at lower temperatures the flux tubes are pinned in place and cannot move this pinning is what holds the superconductor in place thereby allowing it to levitate this phenomenon is closely related to the meissner effect though with one crucial difference — the meissner effect shields the superconductor from all magnetic fields causing repulsion unlike the pinned state of the superconductor disk which pins flux and the superconductor in place
a fly route also called a streak route or go route is a pattern run by a receiver in american football where the receiver runs straight upfield towards the endzone the goal of the pattern is to outrun any defensive backs and get behind them catching an undefended pass while running untouched for a touchdown generally the fastest receiver on the team or any receiver faster than the man covering him would be the one to run these routes when run down the sidelines a fly can be called a fade route fly patterns can also be used to clear out space for other receivers generally a fly pattern will draw the attention of both the cornerback assigned to the receiver as well as over the top help from a safety this can create a large gap in coverage allowing another receiver to run a shorter route but then gain many yards after the catch because the safety committed to the deep man the famed hail mary play generally involves between three and five receivers all running fly routes in order to have the most chance of one of them catching the ball and scoring or at least gaining significant yardage
the flyby anomaly is an unexpected energy increase during earth flybys of spacecraft this anomaly has been observed as shifts in the s band and x band doppler and ranging telemetry taken together it causes a significant unaccounted velocity increase of up to 13 mm s during flybys numerically larger discrepancies 400 – 1000 m have been observed at least in one flyby near against space surveillance network ssn radars
flying squirrel typhus is a condition characterized by a rash of early macules and later maculopapules the flying squirrel glaucomys volans can transmit epidemic typhus apart from humans flying squirrels are the only currently known reservoir for rickettsia prowazekii
the flynn effect is the substantial and long sustained increase in both fluid and crystallized intelligence test scores measured in many parts of the world from roughly 1930 to the present day when intelligence quotient iq tests are initially standardized using a sample of test takers by convention the average of the test results is set to 100 and their standard deviation is set to 15 or 16 iq points when iq tests are revised they are again standardized using a new sample of test takers usually born more recently than the first again the average result is set to 100 however when the new test subjects take the older tests in almost every case their average scores are significantly above 100 test score increases have been continuous and approximately linear from the earliest years of testing to the present for the raven s progressive matrices test subjects born over a 100 year period were compared in des moines united states and separately in dumfries scotland improvements were remarkably consistent across the whole period in both countries this effect of an apparent increase in iq has also been observed in various other parts of the world though the rates of increase vary there are numerous proposed explanations of the flynn effect as well as some skepticism about its implications similar improvements have been reported for other cognitions such as semantic and episodic memory recent research suggests that the flynn effect may have ended in at least a few developed nations possibly allowing national differences in iq scores to determine if the flynn effect continues in nations with lower average national iqs
flynn – aird syndrome is a rare hereditary neurological disease that is inherited in an autosomal dominant fashion the syndrome involves defects in the nervous auditory skeletal visual and endocrine systems and encompasses numerous symptoms bearing striking similarity to other known syndromes of neuroectodermal nature such as werner syndrome cockayne syndrome and refsum syndrome the onset of flynn – aird syndrome typically occurs between ten and twenty years of age however the earliest case was diagnosed at age seven as the syndrome progresses initial symptoms tend to intensify and new symptoms become apparent unlike related syndromes and despite the intensity of symptoms in the disease progression flynn – aird syndrome does not appear to shorten life expectancy the disease is characterized by early onset dementia ataxia muscle wasting skin atrophy and eye abnormalities in addition patients have the potential of developing a number of other related symptoms such as cataracts retinitis pigmentosa myopia nearsightedness dental caries peripheral neuropathy peripheral nerve damage deafness and cystic bone changes this syndrome was first discovered in the early 1950 s by american neurologists p flynn and robert b aird who analyzed one family lineage inheritance pattern of this disease
in computer programming flyweight is a software design pattern a flyweight is an object that minimizes memory use by sharing as much data as possible with other similar objects it is a way to use objects in large numbers when a simple repeated representation would use an unacceptable amount of memory often some parts of the object state can be shared and it is common practice to hold them in external data structures and pass them to the flyweight objects temporarily when they are used a classic example usage of the flyweight pattern is the data structures for graphical representation of characters in a word processor it might be desirable to have for each character in a document a glyph object containing its font outline font metrics and other formatting data but this would amount to hundreds or thousands of bytes for each character instead for every character there might be a reference to a flyweight glyph object shared by every instance of the same character in the document only the position of each character in the document and or the page would need to be stored internally another example is string interning in other contexts the idea of sharing identical data structures is called hash consing
foam lines are accumulations of foam with trapped insects exuvia etc found on the surface of freshwater water courses or bodies lines appear as individual islands of foam that accumulate against obstructions shorelines etc foam lines have some characteristics in common with sea foam from the marine environment which may form lines of spume as the tides rise and fall
the foamy bark canker is a disease affecting oak trees in california caused by the fungus geosmithia pallida and spread by the western oak bark beetle pseudopityopthorus pubipennis this disease is only seen through the symbiosis of the bark beetles and the fungal pathogen the bark beetles target oak trees and bore holes through the peridermal tissues making tunnels within the phloem the fungal spores are brought into these tunnels by the beetles and begin to colonize the damaged cells inside the tunnels symptoms of the developing fungus include wet discoloration seeping from the beetle entry holes as the fungus begins to consume phloem and likely other tissues if bark is removed necrosis of the phloem can be observed surrounding the entry hole s as the disease progresses a reddish sap and foamy liquid oozes from entry holes thus giving the disease the name foamy bark canker eventually after the disease has progressed the tree dies this disease is important because of its detrimental effects on oak trees and its ability to spread to several new californian counties in just a couple years
focal and diffuse brain injury are ways to classify brain injury focal injury occurs in a specific location while diffuse injury occurs over a more widespread area it is common for both focal and diffuse damage to occur as the result of the same event many traumatic brain injuries have aspects of both focal and diffuse injury focal injuries are commonly associated with an injury in which the head strikes or is struck by an object diffuse injuries are more often found in acceleration deceleration injuries in which the head does not necessarily contact anything but brain tissue is damaged because tissue types with varying densities accelerate at different rates in addition to physical trauma other types of brain injury such as stroke can also produce focal and diffuse injuries there may be primary and secondary brain injury processes
focal dermal hypoplasia also known as goltz syndrome is a form of ectodermal dysplasia it is a multisystem disorder characterized primarily by skin manifestations to the atrophic and hypoplastic areas of skin which are present at birth these defects manifest as yellow pink bumps on the skin and pigmentation changes the disorder is also associated with shortness of stature and some evidence suggests that it can cause epilepsy
focal dystonia is a neurological condition that affects a muscle or group of muscles in a specific part of the body causing involuntary muscular contractions and abnormal postures for example in focal hand dystonia the fingers either curl into the palm or extend outward without control in musicians the condition is referred to as musician s focal dystonia or simply musician s dystonia in sports it is commonly referred to as the yips
focal facial dermal dysplasia ffdd is a rare genetically heterogeneous group of disorders that are characterized by congenital bilateral scar like facial lesions with or without associated facial anomalies it is characterized by hairless lesions with fingerprint like puckering of the skin especially at the temples due to alternating bands of dermal and epidermal atrophy this condition is also known as brauer syndrome hereditary symmetrical aplastic nevi of temples bitemporal aplasia cutis congenita bitemporal aplasia cutis congenita omim 136500 and setleis syndrome facial ectodermal dysplasia omim 227260
focal hyperhidrosis is a condition characterized by excessive or profuse sweating in certain body regions it is also referred to as primary hyperhidrosis unlike its counterpart that is generalized or secondary hyperhidrosis it is idiopathic in nature or is not associated with an underlying condition typical regions of excessive sweating include the underarms palms soles groin and craniofacial face scalp areas sweating patterns are typically bilateral or symmetric and rarely occur in just one palm or one underarm night sweats or sweating while sleeping is also rare the onset of focal hyperhidrosis is usually before the age of 25 years this is in contrast to generalized hyperhidrosis which tends to occur in an older age group evidence demonstrates that a positive family history is also present the condition occurs in approximately 3 of the general population prevalence among men and woman is relatively the same profuse sweating is present mostly in the underarms followed by the feet palms and facial region focal hyperhidrosis can have a significant impact on quality of life individuals can be affected from a social psychological emotional and professional perspective the condition has been referred to as the silent handicap for this reason the canadian hyperhidrosis advisory committee has published a comprehensive set of guidelines which outlines key aspects of treatment related to this condition topical hyperhidrosis gels containing aluminum chloride hexahydrate are usually first choice treatments for this condition in addition to topical antiperspirants main active ingredients usually being aluminum or zirconium salts treatment options include iontophoresis hands feet onabotulinumtoxina botox injections underarms hands feet and other localized areas electromagnetic microwave energy thermolysis of underarm sweat glands laser assisted removal of the sweat glands underarms other local procedures such as liposuction and curettage of the sweat glands underarms oral prescription medications anticholinergics and endoscopic thoracic sympathectomy surgery hands
focal nodular hyperplasia fnh is a benign tumor of the liver hepatic tumor which is the second most prevalent tumor of the liver the first is hepatic hemangioma it is usually asymptomatic rarely grows or bleeds and has no malignant potential this tumour was once often resected because it was difficult to distinguish from hepatic adenoma but with modern multiphase imaging is usually now diagnosed by strict imaging criteria and not resected
focal palmoplantar and gingival keratosis is a rare autosomal dominant disease whose clinical features and in particular pathologic alterations and molecular etiology remain to be well defined
focal proliferative nephritis is a type of glomerulonephritis seen in 20 to 35 of cases of lupus nephritis classified as type iii as the name suggests lesions are seen in less than half of the glomeruli typically one or two foci within an otherwise normal glomerulus show swelling and proliferation of endothelial and mesangial cells infiltration by neutrophils and or fibrinoid deposits with capillary thrombi focal glomerulonephritis is usually associated with only mild microscopic hematuria and proteinuria a transition to a more diffuse form of renal involvement is associated with more severe disease
focal segmental glomerulosclerosis fsgs is a cause of nephrotic syndrome in children and adolescents as well as a leading cause of kidney failure in adults it is also known as focal glomerular sclerosis or focal nodular glomerulosclerosis it accounts for about a sixth of the cases of nephrotic syndrome minimal change disease mcd is by far the most common cause of nephrotic syndrome in children mcd and primary fsgs may have a similar cause
focus recovery from a defocused image is an ill posed problem since it loses the component of high frequency most of the methods for focus recovery are based on depth estimation theory the linear canonical transform lct gives a scalable kernel to fit many well known optical effects using lcts to approximate an optical system for imaging and inverting this system theoretically permits recovery of a defocused image
in computing focus stealing is a mode error produced when a program not in focus e g minimized or operating in background places a window in the foreground and redirects all keyboard input to that window this is considered to be an annoyance or hazard to some users because the program may steal the focus while their attention is not on the computer screen such as when typing while reading copy to the side this will cause everything typed after the window appeared to be lost or worse the typed input may cause an unintended effect in the newly focused window on slow computers users are sometimes not even alerted to this behavior in time because the associated window is only actually displayed several seconds after the actual focus change happened
fog is a visible mass consisting of cloud water droplets or ice crystals suspended in the air at or near the earth s surface fog can be considered a type of low lying cloud and is heavily influenced by nearby bodies of water topography and wind conditions in turn fog has affected many human activities such as shipping travel and warfare
a fog bow is a similar phenomenon to a rainbow however as its name suggests it appears as a bow in fog rather than rain because of the very small size of water droplets that cause fog — smaller than 0 05 millimeters 0 0020 in — the fog bow has only very weak colors with a red outer edge and bluish inner edge in many cases when the droplets are very small fog bows appear white and are therefore sometimes called white rainbows this lack of color is a feature of a fog bow which distinguishes it from a glory which has multiple pale colored rings caused by diffraction when the droplets forming it are almost all of the same size the fog bow can have multiple inner rings or supernumeraries that are more strongly colored than the main bow according to nasa the fogbow s lack of colors is caused by the smaller water drops so small that the wavelength of light becomes important diffraction smears out colors that would be created by larger rainbow water drops a fog bow seen in clouds typically from an aircraft looking downwards is called a cloud bow mariners sometimes call fog bows sea dogs
fogging in photography is the deterioration in the quality of the image caused either by extraneous light or the effects of a processing chemical
foix – alajouanine syndrome is a disorder caused by an arteriovenous malformation of the spinal cord the patients present with symptoms indicating spinal cord involvement paralysis of arms and legs numbness and loss of sensation and sphincter dysfunction and pathological examination reveals disseminated nerve cell death in the spinal cord and abnormally dilated and tortuous vessels situated on the surface of the spinal cord surgical treatment can be tried in some cases if surgical intervention is contraindicated corticosteroids may be used the condition is named after charles foix and théophile alajouanine
foix – chavany – marie syndrome also known as bilateral anterior opercular syndrome is a partial paralysis of the face pharynx and jaw caused by bilateral damage to a specific region of the brain the operculum it is named for those who in 1926 first described the condition — charles foix jean alfred émile chavany and julien marie — in a paper published in the revue neurologique as a characteristic there is no paralysis of upper or lower limbs and those affected can still make involuntary movement like smiling eating or blinking eyes
folate deficiency is a low level of folic acid in the body also known as vitamin b 9 it is involved in adenosine guanine and thymidine synthesis part of dna synthesis signs of folate deficiency are often subtle anemia is a late finding in folate deficiency and folate deficiency anemia is the term given for this medical condition characterized by the appearance of large sized abnormal red blood cells megaloblasts which form when there are inadequate stores of folic acid within the body
folie à deux fɒˈli ə ˈduː french pronunciation ​ fɔli a dø french for madness of two or shared psychosis is a psychiatric syndrome in which symptoms of a delusional belief and hallucinations are transmitted from one individual to another the same syndrome shared by more than two people may be called folie à trois folie à quatre folie en famille or even folie à plusieurs madness of many recent psychiatric classifications refer to the syndrome as shared psychotic disorder dsm iv 297 3 and induced delusional disorder f 24 in the icd 10 although the research literature largely uses the original name this disorder is not in the current dsm dsm v the disorder was first conceptualized in 19 th century french psychiatry by charles lasègue and jean pierre falret and so also known as lasègue falret syndrome
follicle stimulating hormone fsh insensitivity or ovarian insensitivity to fsh in females also referable to as ovarian follicle hypoplasia or granulosa cell hypoplasia in females is a rare autosomal recessive genetic and endocrine syndrome affecting both females and males with the former presenting with much greater severity of symptomatology it is characterized by a resistance or complete insensitivity to the effects of follicle stimulating hormone fsh a gonadotropin which is normally responsible for the stimulation of estrogen production by the ovaries in females and maintenance of fertility in both sexes the condition manifests itself as hypergonadotropic hypogonadism decreased or lack of production of sex steroids by the gonads despite high circulating levels of gonadotropins reduced or absent puberty lack of development of secondary sexual characteristics resulting in sexual infantilism if left untreated amenorrhea lack of menstruation and infertility in females whereas males present merely with varying degrees of infertility and associated symptoms e g decreased sperm production a related condition is luteinizing hormone lh insensitivity termed leydig cell hypoplasia when it occurs in males which presents with similar symptoms to those of fsh insensitivity but with the symptoms in the respective sexes reversed i e hypogonadism and sexual infantilism in males and merely problems with fertility in females however males also present with feminized or ambiguous genitalia also known as pseudohermaphroditism whereas ambiguous genitalia does not occur in females with fsh insensitivity despite their similar causes lh insensitivity is considerably more common in comparison to fsh insensitivity
follicular atrophoderma is a skin condition consisting of follicular indentations without hairs notably occurring on extensor surfaces of the hands legs and arms
the follicular cyst of ovary or graafian follicle cyst or follicular cyst is a type of functional simple cyst and is the most common type of ovarian cyst
follicular hybrid cyst also known as a hybrid cyst is a cutaneous condition characterized by a cyst composed of several adnexal components
follicular hyperplasia or reactive follicular hyperplasia or lymphoid nodular hyperplasia is a type of lymphoid hyperplasia it is caused by a stimulation of the b cell compartment it is caused by an abnormal proliferation of secondary follicles and occurs principally in the cortex without broaching the lymph node capsule the follicles are cytologically polymorphous are often polarized and vary in size and shape follicular hyperplasia must be distinguished from follicular lymphoma bcl 2 protein is expressed in neoplastic follicles but not reactive follicles
follicular lymphoma is a type of blood cancer it is the most common of the indolent slow growing non hodgkin s lymphomas and the second most common form of non hodgkin s lymphomas overall it is defined as a lymphoma of follicle center b cells centrocytes and centroblasts which has at least a partially follicular pattern it is positive for the b cell markers cd 10 cd 19 cd 22 and usually cd 20 but almost always negative for cd 5 there are several synonymous and obsolete terms for this disease such as cb cc lymphoma centroblastic and centrocytic lymphoma nodular lymphoma and brill symmers disease
follicular thyroid cancer or follicular thyroid carcinoma accounts for 15 of thyroid cancer and occurs more commonly in women over 50 years of age thyroglobulin tg can be used as a tumor marker for well differentiated follicular thyroid cancer follicular cells are the thyroid cells responsible for the production and secretion of thyroid hormones
folliculitis is the infection and inflammation of one or more hair follicles the condition may occur anywhere on the skin with the exception of the palms of the hands and soles of the feet the rash may appear as pimples that come to white tips on the face chest back arms legs and head
folliculitis decalvans is an inflammation of the hair follicle that leads to bogginess or induration of involved parts of the scalp along with pustules erosions crusts and scale it begins at a central point and spreads outward leaving scarring sores and due to the inflammation hair loss in its wake no permanent cure has been found for this condition but there is promise in a regimen of dual therapy with rifampin 300 mg twice daily and clindamycin 300 mg twice daily this new treatment can be used to control the condition and tests have indicated that after 3 to 5 months long uninterrupted courses of treatment many patients have seen limited to no recurrence
a folliculosebaceous apocrine hamartoma also known as follicular apocrine hamartoma is a benign proliferation of the folliculosebaceous apocrine unit
in a marching band follow the leader is a visual effect in which one band member follows the next the move can be from side to side front to back or diagonal advanced follow the leader movements may have bézier curves follow the leader can also refer to a children s game where one child plays the leader and leads others around a playground or an area making repetitive actions that the others subsequently follow
a food allergy is an abnormal immune response to food the signs and symptoms may range from mild to severe they may include itchiness swelling of the tongue vomiting diarrhea hives trouble breathing or low blood pressure this typically occurs within minutes to several hours of exposure when the symptoms are severe it is known as anaphylaxis food intolerance and food poisoning are separate conditions common foods involved include cow s milk peanuts eggs shellfish tree nuts wheat rice and fruit the common allergies in a region vary depending on the country risk factors include a family history of allergies vitamin d deficiency obesity and high levels of cleanliness allergies occur when immunoglobulin e ige part of the body s immune system binds to food molecules it is usually a protein in the food that is the problem this triggers the release of inflammatory chemicals such as histamine diagnosis is usually based on a medical history elimination diet skin prick test blood tests for food specific ige antibodies or oral food challenge early exposure to potential allergens may be protective management primarily involves avoiding the food in question and having a plan if exposure occurs this plan may include giving adrenaline epinephrine and wearing medical alert jewelry the benefits of allergen immunotherapy for food allergies is unclear and thus not recommended as of 2015 some types of food allergies among children resolve with age including that to milk eggs and soy while others such as to nuts and shellfish typically do not in the developed world about 4 to 8 of people have at least one food allergy they are more common in children than adults and appear to be increasing in frequency male children appear to be more commonly affected than females some allergies more commonly develop early in life while others typically develop in later life in developed countries a large proportion of people believe they have food allergies when they actually do not have them
a food craving also called selective hunger is an intense desire to consume a specific food and is different from normal hunger it may or may not be related to specific hunger the drive to consume particular nutrients that is well studied in animals in studies of food cravings chocolate and chocolate confectioneries almost always top the list of foods people say they crave this craving is referred to as chocoholism
food intolerance or non allergic food hypersensitivity is a detrimental reaction often delayed to a food beverage food additive or compound found in foods that produces symptoms in one or more body organs and systems but generally refers to reactions other than food allergy food allergies are immune reactions involving mast cells in which food triggers release of mast cell mediators such as histamine when the food allergen binds to pre formed ige antibodies already bound to the mast cell this mechanism causes allergies to typically give immediate reaction a few minutes to a few hours to foods there are numerous causes for other types of food sensitivities most of which in contrast to food allergies cause delayed hypersensitivity reactions to the food food intolerances can be classified according to their mechanism intolerance can result from the absence of specific chemicals or enzymes needed to digest a food substance as in hereditary fructose intolerance it may be a result of an abnormality in the body s ability to absorb nutrients as occurs in fructose malabsorption food intolerance reactions can occur to naturally occurring chemicals in foods as in salicylate sensitivity drugs sourced from plants such as aspirin can also cause these kinds of reactions finally it may be the result of non ige mediated immune responses
food security is a condition related to the supply of food and individuals access to it concerns over food security have existed throughout history there is evidence of granaries being in use over 10 000 years ago with central authorities in civilizations including ancient china and ancient egypt being known to release food from storage in times of famine at the 1974 world food conference the term food security was defined with an emphasis on supply food security they said is the availability at all times of adequate world food supplies of basic foodstuffs to sustain a steady expansion of food consumption and to offset fluctuations in production and prices later definitions added demand and access issues to the definition the final report of the 1996 world food summit states that food security exists when all people at all times have physical and economic access to sufficient safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life household food security does not exists when all members at all times have access to plentiful food for an active healthy life individuals who are food secure do not live in hunger or fear of starvation food insecurity on the other hand is a situation of limited or uncertain availability of nutritionally adequate and safe foods or limited or uncertain ability to acquire acceptable foods in socially acceptable ways according to the united states department of agriculture usda food security incorporates a measure of resilience to future disruption or unavailability of critical food supply due to various risk factors including droughts shipping disruptions fuel shortages economic instability and wars in the years 2011 2013 an estimated 842 million people were suffering from chronic hunger the food and agriculture organization of the united nations or fao identified the four pillars of food security as availability access utilization and stability the united nations un recognized the right to food in the declaration of human rights in 1948 and has since noted that it is vital for the enjoyment of all other rights the 1996 world summit on food security declared that food should not be used as an instrument for political and economic pressure according to the international centre for trade and sustainable development failed agriculture market regulation and the lack of anti dumping mechanisms cause much of the world s food scarcity and malnutrition
fool s growth is a problem in macro economical econometric models based on gdp when these assume economic growth measured in marked trade prices while the output value to citizens drop this problem introduces a substantial error in political choice theory and can easily lead to failures by assumption as some good is taken for granted while ignoring the costs elsewhere the essential problem is that the commercial profit is measured and included in the concept of growth whereas the value to the end consumer is not therefore these models are biased towards policies that favor commercial profit over creating overall value the consequences of a fool s growth mistake are policies that for instance promote anti competitive e g monopolies lock in e g bad standards that prevent innovation or value destructive political investments
foolishness is the lack or failure of wisdom and of making proper careful choices in this sense it differs from stupidity which is the lack of intelligence an act of foolishness is called folly foolish talk is called stultiloquence foolishness and wisdom are contrasted in paul s letter to the corinthians he condemns intellectual arrogance and advocates a humble attitude of foolishness in which it is then possible to learn plato likewise said he is the wisest man who knows himself to be ill equipped for the study of wisdom but paul makes a distinction between wisdom and the reason of the greeks
foot and mouth disease or hoof and mouth disease aphthae epizooticae is an infectious and sometimes fatal viral disease that affects cloven hoofed animals including domestic and wild bovids the virus causes a high fever for approximately two to six days followed by blisters inside the mouth and on the feet that may rupture and cause lameness foot and mouth disease fmd has severe implications for animal farming since it is highly infectious and can be spread by infected animals through aerosols through contact with contaminated farming equipment vehicles clothing or feed and by domestic and wild predators its containment demands considerable efforts in vaccination strict monitoring trade restrictions and quarantines and occasionally the killing of animals susceptible animals include cattle water buffalo sheep goats pigs antelope deer and bison it has also been known to infect hedgehogs and elephants llamas and alpacas may develop mild symptoms but are resistant to the disease and do not pass it on to others of the same species in laboratory experiments mice rats and chickens have been successfully infected by artificial means but they are not believed to contract the disease under natural conditions humans are very rarely infected the virus responsible for the disease is a picornavirus the prototypic member of the genus aphthovirus infection occurs when the virus particle is taken into a cell of the host the cell is then forced to manufacture thousands of copies of the virus and eventually bursts releasing the new particles in the blood the virus is genetically highly variable which limits the effectiveness of vaccination
a foot deformity is a disorder of the foot that can be congenital or acquired such deformities can include hammer toe club foot flat feet pes cavus etc
foot drop is a gait abnormality in which the dropping of the forefoot happens due to weakness irritation or damage to the common fibular nerve including the sciatic nerve or paralysis of the muscles in the anterior portion of the lower leg it is usually a symptom of a greater problem not a disease in itself it is characterized by inability or impaired ability to raise the toes or raise the foot from the ankle dorsiflexion foot drop may be temporary or permanent depending on the extent of muscle weakness or paralysis and it can occur in one or both feet in walking the raised leg is slightly bent at the knee to prevent the foot from dragging along the ground foot drop can be caused by nerve damage alone or by muscle or spinal cord trauma abnormal anatomy toxins or disease toxins include organophosphorus compounds which have been used as pesticides and as a chemical agent in warfare the poison can lead to further damage to the body such as a neurodegenerative disorder called organophosphorus induced delayed polyneuropathy this disorder causes loss of function of the motor and sensory neuropathways in this case foot drop could be the result of paralysis due to neurological dysfunction diseases that can cause foot drop include direct hit to posterolateral neck of fibula stroke amyotrophic lateral sclerosis als or lou gehrig s disease muscular dystrophy charcot marie tooth disease multiple sclerosis cerebral palsy hereditary spastic paraplegia guillain – barré syndrome and friedreich s ataxia it may also occur as a result of hip replacement surgery or knee ligament reconstruction surgery
foot rot or infectious pododermatitis is a hoof infection commonly found in sheep goats and cattle as the name suggests it rots away the foot of the animal more specifically the area between the two toes of the affected animal it is extremely painful and contagious it can be treated with a series of medications but if not treated the whole herd can become infected the cause of the infection in cattle are two species of anaerobic bacteria bacteria that can grow without oxygen fusobacterium necrophorum and bacteroides melaninogenicus both bacteria are common to the environment in which cattle live and fusobacterium is present in the rumen and fecal matter of the cattle in sheep the fusobacterium necrophorum first invades the interdigital skin following damage to the skin and causes interdigital lesions and slight inflammation the second stage of the disease is marked by the invasion of the foot by the foot rot bacterium dichelobacter nodosus a gram negative anaerobe usually there is an injury to the skin between the hooves that allows the bacteria to infect the animal another cause of foot rot may be high temperatures or humidity causing the skin between the hooves to crack and let the bacteria infect the foot this is one of the reasons foot rot is such a major problem in the summer foot rot is easily identifiable by its appearance and foul odor treatment is usually with an antibiotic medication and preventing injury to the feet is the best way to prevent foot rot the disease is different in cattle and sheep and cross infection is not thought to occur
foot voting is the ability of people to vote with their feet by leaving situations they do not like or going to situations they believe to be more beneficial it has been described as a tool for enhancing political freedom the ability of the people to choose the political regime under which they wish to live
a forbush decrease is a rapid decrease in the observed galactic cosmic ray intensity following a coronal mass ejection cme it occurs due to the magnetic field of the plasma solar wind sweeping some of the galactic cosmic rays away from earth the term forbush decrease was named after the american physicist scott e forbush who studied cosmic rays in the 1930 s and 1940 s
in neuropsychiatry a forced normalization is a specific phenomenon landolt concluded that forced normalization fn is “ the phenomenon characterized by the fact that with the occurrence of psychotic states the electroencephalography becomes more normal or entirely normal as compared with previous and subsequent eeg findings ” fn as described by landolt was therefore an electrophysiological phenomenon with the eeg at its helm tellenbach ’ s description of “ alternative psychosis ” or the reciprocal relationship between abnormal mental states and seizures differed from landolt ’ s in its clinical rather than eeg description subsequently this concept was refined by wolf who suggested that the term “ paradoxical normalization ” was more appropriate and closer to what landolt intended wherein both epileptic processes – subcortical and restricted – and inhibitory processes are active at the same time
in electrical engineering forced outage is the shutdown condition of a power station transmission line or distribution line when the generating unit is unavailable to produce power due to unexpected breakdown forced outage can be caused by equipment failures disruption in the power plant fuel supply chain operator error etc
in a system of differential equations used to describe a time dependent process a forcing function is a function that appears in the equations and is only a function of time not of any of the other variables in effect it is a constant for each value of t in the more general case any nonhomogeneous source function in any variable can be described as a forcing function and the resulting solution can often be determined using a superposition of linear combinations of the homogeneous solutions and the forcing term
in geology a forebulge is a flexural bulge in front of a load on the lithosphere this load causes the lithosphere to flex by depressing the plate beneath it because of the flexural rigidity of the lithosphere the area around the load is uplifted by a height that is 4 of that of the depression under the load this load and resulting flexure place stress on the mantle causing it to flow into the area around the loaded area the subsidence of the area under the load and the uplift of the forebulge continue until the load is in isostatic equilibrium a process which takes on the order of ten to twenty thousand years because of the coupling with the mantle the rate of forebulge formation and collapse is controlled by mantle viscosity
in statistics a forecast error is the difference between the actual or real and the predicted or forecast value of a time series or any other phenomenon of interest since the forecast error is derived from the same scale of data comparisons between the forecast errors of different series can only be made when the series are on the same scale in simple cases a forecast is compared with an outcome at a single time point and a summary of forecast errors is constructed over a collection of such time points here the forecast may be assessed using the difference or using a proportional error by convention the error is defined using the value of the outcome minus the value of the forecast in other cases a forecast may consist of predicted values over a number of lead times in this case an assessment of forecast error may need to consider more general ways of assessing the match between the time profiles of the forecast and the outcome if a main application of the forecast is to predict when certain thresholds will be crossed one possible way of assessing the forecast is to use the timing error — the difference in time between when the outcome crosses the threshold and when the forecast does so when there is interest in the maximum value being reached assessment of forecasts can be done using any of the difference of times of the peaks the difference in the peak values in the forecast and outcome the difference between the peak value of the outcome and the value forecast for that time point forecast error can be a calendar forecast error or a cross sectional forecast error when we want to summarize the forecast error over a group of units if we observe the average forecast error for a time series of forecasts for the same product or phenomenon then we call this a calendar forecast error or time series forecast error if we observe this for multiple products for the same period then this is a cross sectional performance error reference class forecasting has been developed to reduce forecast error combining forecasts has also been shown to reduce forecast error
forecast verification is a subfield of the climate atmospheric and ocean sciences dealing with validating verifying as well as determining the predictive power of prognostic model forecasts because of the complexity of these models forecast verification goes a good deal beyond simple measures of statistical association or mean error calculations
foreign accent syndrome is a rare medical condition in which patients develop speech patterns that are perceived as a foreign accent that is different from their native accent without having acquired it in the perceived accent s place of origin foreign accent syndrome usually results from a stroke but can also develop from head trauma migraines or developmental problems the condition was first reported in 1907 and between 1941 and 2009 there were sixty two recorded cases its symptoms result from distorted articulatory planning and coordination processes and although popular news articles commonly attempt to identify the closest regional accent speakers suffering from foreign accent syndrome acquire neither a specific foreign accent nor any additional fluency in a foreign language despite an unconfirmed news report in 2010 that a croatian speaker had gained the ability to speak fluent german after emergence from a coma there has been no verified case where a patient s foreign language skills have improved after a brain injury there have been a few reported cases of children and siblings picking up the new accent from someone with foreign accent syndrome
there is a significant amount of foreign aid to sudan including a large amount of relief aid from international organizations to alleviate the effects of civil wars in the south and in darfur amounts vary according to the intensity of the conflicts and rainfall patterns both of which affect food production much aid is channeled through the united nations which sought to raise us 225 million for its programs in 2003 – 04
a foreign body or sometimes known as fb latin corpus alienum is any object originating outside the body in machinery it can mean any unwanted intruding object most references to foreign bodies involve propulsion through natural orifices into hollow organs foreign bodies can be inert or irritating if they irritate they will cause inflammation and scarring they can bring infection into the body or acquire infectious agents and protect them from the body s immune defenses they can obstruct passageways either by their size or by the scarring they cause some can be toxic with sufficient force as in firing of bullets a foreign body can become lodged into nearly any tissue
foreign body aspiration is when a foreign body to enter the airways and causes choking a foreign body in the bronchi usually causes a cough
the foreign body granuloma is a response of biological tissue to any foreign material in the tissue tissue encapsulation of an implant is part of this an infection around a splinter is part of this too the presence of the implant changes the healing response and this is called the foreign body reaction fbr fbr consists of protein adsorption macrophages multinucleated foreign body giant cells macrophage fusion fibroblasts and angiogenesis it can be caused by beryllium
one of the most common locations for a foreign body is the alimentary tract it is possible for foreign bodies to enter the tract from the mouth or from the rectum the objects most commonly swallowed by children are coins meat impaction is more common in adults swallowed objects are more likely to lodge in the esophagus or stomach than in the pharynx or duodenum
foresight is the ability to predict or the action of predicting what will happen or what is needed in the future studies suggest that much of human daily thought is directed towards potential future events because of this and its role in human control on the planet the nature and evolution of foresight is an important topic in psychology recent neuroscientific developmental and cognitive studies have identified many commonalities to the human ability to recall past episodes science magazine selected new evidence for such commonalities one of the top ten scientific breakthroughs of 2007 however there are fundamental differences between mentally travelling through time into the future i e foresight versus mentally travelling through time into the past i e episodic memory
the forest vegetation simulator fvs is a forest growth and yield model developed by the united states forest service and is used by natural resource managers and researchers fvs is calibrated for specific geographic areas and uses a host of simulation models to forecast forest composition and structure fvs uses current forest inventory data to describe initial stand conditions and requires a description of the inventory design stand attributes and a list of individual tree information extensions to fvs are available to assess the effects of forest insects and diseases fire and forest carbon
forest dieback also waldsterben a german loan word is a condition in trees or woody plants in which peripheral parts are killed either by pathogens parasites or due to conditions like acid rain and drought two of the nine tipping points for major climate changes forecast for the next century are directly related to forest diebacks phomopsis azadirachtae is a fungus of the phomopsis genus that has been identified as the fungus responsible for dieback of azadirachta indica neem in india
a form constant is one of several geometric patterns which are recurringly observed during hallucinations and altered states of consciousness
in elementary particle physics and mathematical physics in particular in effective field theory a form factor is a function that encapsulates the properties of a certain particle interaction without including all of the underlying physics but instead providing the momentum dependence of suitable matrix elements it is further measured experimentally in confirmation or specification of a theory — see experimental particle physics
formability is the ability of a given metal workpiece to undergo plastic deformation without being damaged the plastic deformation capacity of metallic materials however is limited to a certain extent at which point the material could experience tearing or fracture breakage processes affected by the formability of a material include rolling extrusion forging rollforming stamping and hydroforming
in philosophy a formal fallacy also called deductive fallacy is a pattern of reasoning rendered invalid by a flaw in its logical structure that can neatly be expressed in a standard logic system for example propositional logic an argument that is formally fallacious is always considered wrong a formal fallacy is contrasted with an informal fallacy which may have a valid logical form and yet be unsound because one or more premises are false the presence of a formal fallacy in a deductive argument does not imply anything about the argument s premises or its conclusion both may actually be true or even more probable as a result of the argument but the deductive argument is still invalid because the conclusion does not follow from the premises in the manner described by extension an argument can contain a formal fallacy even if the argument is not a deductive one for instance an inductive argument that incorrectly applies principles of probability or causality can be said to commit a formal fallacy fallacious arguments usually have the deceptive appearance of being good arguments recognizing fallacies in everyday arguments may be difficult since arguments are often embedded in rhetorical patterns that obscure the logical connections between statements informal fallacies may also exploit the emotional intellectual or psychological weaknesses of the audience having the capability to recognize fallacies in arguments is one way to reduce the likelihood of such occurrences argumentation theory provides a different approach to understanding and classifying fallacies in this approach an argument is regarded as an interactive protocol between individuals that attempts to resolve their disagreements the protocol is regulated by certain rules of interaction and violations of these rules are fallacies such fallacies are used in many forms of modern communications where the intention is to influence behavior and change beliefs examples in the mass media today include but are not limited to propaganda advertisements politics newspaper editorials and opinion based “ news ” shows
format is a function in common lisp that can produce formatted text using a format string similar to the printf format string it provides more functionality than printf allowing the user to output numbers in english apply certain format specifiers only under certain conditions iterate over data structures and output in a tabular format this functionally originates in mit s lisp machine lisp where it was based on multics ioa
in medicine a forme fruste french “ crude or unfinished form ” pl formes frustes is an atypical or attenuated manifestation of a disease or syndrome with the implications of incompleteness partial presence or aborted state the context is usually one of a well defined clinical or pathological entity which the case at hand almost — but not quite — fits an opposite term in medicine forme pleine — seldom used by english speaking physicians — means the complete or full blown form of a disease
fort darnet like fort hoo was built on the recommendations of the 1859 royal commission on an island covering the inner navigable channel of the river medway kent originally designed for two tiers of guns mounted in a circle with a boom strung between them there were many problems with subsidence and after extensive cost overruns the forts were completed in 1871 with one tier and 11 guns a mixture of 9 inch and 7 inch rifled muzzle loaders and no boom the forts were never used in anger and were disarmed before the first world war in the second world war the fort was used as observation posts with platforms and pillboxes built on top the fort is still in fair condition however the magazine level seems to have been deliberately flooded to minimise access and vandalism the island can be freely visited by boat though the landing is muddy
foster – kennedy syndrome also known as gowers – paton – kennedy syndrome kennedy s phenomenon or kennedy s syndrome refers to a constellation of findings associated with tumors of the frontal lobe although foster – kennedy syndrome is equated with kennedy syndrome it should not be confused with kennedy disease which is named for william r kennedy pseudo foster – kennedy syndrome is defined as one sided optic atrophy with papilledema in the other eye but with the absence of a mass
fouling is the accumulation of unwanted material on solid surfaces to the detriment of function the fouling materials can consist of either living organisms biofouling or a non living substance inorganic or organic fouling is usually distinguished from other surface growth phenomena in that it occurs on a surface of a component system or plant performing a defined and useful function and that the fouling process impedes or interferes with this function other terms used in the literature to describe fouling include deposit formation encrustation crudding deposition scaling scale formation slagging and sludge formation the last six terms have a more narrow meaning than fouling within the scope of the fouling science and technology and they also have meanings outside of this scope therefore they should be used with caution fouling phenomena are common and diverse ranging from fouling of ship hulls natural surfaces in the marine environment marine fouling fouling of heat transfer components through ingredients contained in the cooling water or gases and even the development of plaque or calculus on teeth or deposits on solar panels on mars among other examples this article is primarily devoted to the fouling of industrial heat exchangers although the same theory is generally applicable to other varieties of fouling in the cooling technology and other technical fields a distinction is made between macro fouling and micro fouling of the two micro fouling is the one which is usually more difficult to prevent and therefore more important
foundation is a skin coloured makeup applied to the face to create an even uniform colour to the complexion to cover flaws and sometimes to change the natural skintone some foundations also function as a moisturizer sunscreen astringent or base layer for more complex cosmetics foundation applied to the body is generally referred to as body painting
in population genetics the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population it was first fully outlined by ernst mayr in 1942 using existing theoretical work by those such as sewall wright as a result of the loss of genetic variation the new population may be distinctively different both genotypically and phenotypically from the parent population from which it is derived in extreme cases the founder effect is thought to lead to the speciation and subsequent evolution of new species in the figure shown the original population has nearly equal numbers of blue and red individuals the three smaller founder populations show that one or the other color may predominate founder effect due to random sampling of the original population a population bottleneck may also cause a founder effect though it is not strictly a new population the founder effect occurs when a small group of migrants that is not genetically representative of the population from which they came establish in a new area in addition to founder effects the new population is often a very small population so shows increased sensitivity to genetic drift an increase in inbreeding and relatively low genetic variation this can be observed in the limited gene pools of icelanders ashkenazi jews faroe islanders easter islanders and those native to pitcairn island another example is the remarkably high deaf population of martha s vineyard which resulted in the development of martha s vineyard sign language
the fountain is a juggling pattern that is the method most often used for juggling an even number of objects in a fountain each hand juggles separately and the objects are not thrown between the hands to illustrate this it can be seen that in the most common fountain pattern where four balls are juggled each hand juggles two balls independently as crego states in the fountain pattern each hand throws balls straight up into the air and each ball is caught in the same hand that throws it a fountain can be synchronous or asynchronous in a synchronous fountain both hands throw at the same time while in an asynchronous fountain the hands alternate throws the fountain pattern can be stably performed in two ways one can perform the fountain with different frequencies for the two hands but that coordination is difficult because of the tendency of the limbs to synchronize the fountain is juggled in either a circular fashion or in columns the circular method means that the balls juggled travel in a circle like motion with the jugglers hands throwing the ball from a point close to their body centre line and catching the ball further away from their body centre line this circle motion is called outside circles and is the fountain pattern shown in the animation this circle method can be reversed to create an inside circle pattern whereby throws are from a position away from the body midline and catches are closer to the body midline in the columns method the balls all travel vertically up and down in their own column and are caught from where they are thrown the fountain is used for juggling even numbers of objects because other patterns which alternate between hands such as the cascade do not work well for even numbers of objects
fountain syndrome is an autosomal recessive congenital disorder characterized by mental retardation deafness skeletal abnormalities and a coarse face with full lips the abnormal swelling of the cheeks and lips are due to the excessive accumulation of body fluids under the skin the deafness is due to malformation of the cochlea structure within the inner ear
four stroking is an operating condition of two stroke engines where they instead begin to fire every four strokes or more rather than every two strokes this firing is uneven noisy and may even in cases where it doesn t occur normally damage the engine if allowed to continue unabated however in some circumstances four stroking is normal when idling most two stroke engines will four stroke as well as when letting off the throttle four stroking will also occur in a correctly adjusted two stroke engine at full throttle without load in the latter case this happens because the air fuel mixture becomes overly rich and prevents the engine from running faster the engine is intentionally constructed by the manufacturer for this to happen as a too lean mixture will cause the engine to over rev as well as overheat and in engines running on premixed fuel a too lean mixture will cause poor lubrication running the engine at full throttle without load is not normally done in most applications but in a chain saw the full throttle mixture is actually adjusted for the engine to four stroke at a given rpm set by the manufacturer this is done by adjusting the high rpm screw on the carburetor while the engine runs at full throttle until the correct rpm level can be read on a tachometer
four wave mixing fwm is an intermodulation phenomenon in non linear optics whereby interactions between two or three wavelengths produce two or one new wavelengths it is similar to the third order intercept point in electrical systems four wave mixing can be compared to the intermodulation distortion in standard electrical systems it is a parametric nonlinear process in that the energy of the incoming photons is conserved fwm is a phase sensitive process in that the efficiency of the process is strongly affected by phase matching conditions
in the mythological cycle of early irish literature the four treasures or jewels of the tuatha dé danann are four magical items which the mythological tuatha dé danann are supposed to have brought with them from the four island cities murias falias gorias and findias when they arrived in ireland
four on the floor or four to the floor is a rhythm pattern used in disco and electronic dance music it is a steady uniformly accented beat in 4 4 time in which the bass drum is hit on every beat 1 2 3 4 in common time this was popularized in the disco music of the 1970 sand the term four on the floor was widely used in that era it originated with the pedal operated drum kit bass drum many styles of electronic dance music particularly those that are derived from house and techno use this beat as an important part of the rhythmic structure sometimes the term is used to refer to a 4 4 uniform drumming pattern for any drum a form of four on the floor is also used in jazz drumming instead of hitting the bass drum in a pronounced and therefore easily audible fashion it is usually struck very lightly referred to as feathering so that the sound of the drum is felt instead of heard by the listener typically this is combined with a ride cymbal and hi hat in syncopation when a string instrument makes the rhythm rhythm guitar banjo all four beats of the measure are played by identical downstrokes in reggae drumming the bass drum usually hits on the third beat but sometimes drummers play four on the floor sly dunbar from sly robbie was one of the reggae drummers that played mostly in this style also carlton barrett from bob marley the wailers played four on the floor on several hits by the wailers like is this love and exodus in reggae four on the floor usually goes by the hand with a low end and powerful bassline four on the floor can be found in more modern reggae derivative styles like dancehall while it is less common to find it in roots reggae
fournier gangrene is a type of necrotizing fasciitis or gangrene affecting the perineum it commonly occurs in elderly men but itcan also occur in women and children it is more likely to occur in those with diabetes alcoholics or those who are immune compromised it was first described by baurienne in 1764 and is named after a french venereologist jean alfred fournier following five cases he presented in clinical lectures in 1883
in the fictional world of middle earth the fourth age and the ages that preceded it are time periods from j r r tolkien s universe of middle earth described in his fantasy writings because most of his fiction concerning middle earth deals with earlier ages there is relatively little material on the ages that followed the third age the fourth age followed the defeat of sauron and the destruction of his one ring but did not officially begin until after the bearers of the three rings left middle earth for valinor the uttermost west some events of the first centuries of the fourth age can be gleaned from the appendices in the lord of the rings and follow below
the fourth heart sound or s 4 is a rare extra heart sound that occurs immediately before the normal two lub dub heart sounds s 1 and s 2 it occurs just after atrial contraction and immediately before the systolic s 1 and is caused by the atria contracting forcefully in an effort to overcome an abnormally stiff or hypertrophic ventricle this produces a rhythm classically compared to the cadence of the word tennessee one can also use the phrase a stiff wall to help with the cadence a s 4 stiff s 1 wall s 2 as well as the pathology of the s 4 sound
fourth cranial nerve palsy also known as trochlear nerve palsy is a condition affecting cranial nerve 4 iv the trochlear nerve which is one of the cranial cranial nerves that causes weakness or paralysis to the superior oblique muscle superior oblique muscle that it innervates this condition often causes vertical or near vertical double vision as the weakened muscle prevents the eyes from moving in the same direction together because the fourth cranial nerve is the thinnest and has the longest intracranial course of the cranial nerves it is particularly vulnerable to traumatic injury to compensate for the double vision resulting from the weakness of the superior oblique patients characteristically tilt their head down and to the side opposite the affected muscle when present at birth it is known as congenital fourth nerve palsy
foville s syndrome is caused by the blockage of the perforating branches of the basilar artery in the region of the brainstem known as the pons structures affected by the infarct are the pprf nuclei of cranial nerves vi and vii corticospinal tract medial lemniscus and the medial longitudinal fasciculus
fowler noll vo is a non cryptographic hash function created by glenn fowler landon curt noll and kiem phong vo the basis of the fnv hash algorithm was taken from an idea sent as reviewer comments to the ieee posix p 1003 2 committee by glenn fowler and phong vo in 1991 in a subsequent ballot round landon curt noll improved on their algorithm in an email message to landon they named it the fowler noll vo or fnv hash
fowlpox is the worldwide disease of poultry caused by viruses of the family poxviridae and the genus avipoxvirus the viruses causing fowlpox are distinct from one another but antigenically similar possible hosts including chickens turkeys quail canaries pigeons and many other species of birds there are two forms of the disease the first is spread by biting insects especially mosquitoes and wound contamination and causes lesions on the comb wattles and beak birds affected by this form usually recover within a few weeks the second form is spread by inhalation of the virus and causes a diphtheritic membrane to form in the mouth pharynx larynx and sometimes the trachea the prognosis for this form is poor
fox – fordyce disease or apocrine miliaria is a chronic blockage of the sweat gland ducts with a secondary non bacterial inflammatory response to the secretions and cellular debris in the cysts hidradenitis is very similar but tends to have a secondary bacterial infection so that pus draining sinuses are formed it is a very devastating skin disease that does not have universally curative treatments many that have this disease avoid sweat inducing activities and prefer swimming as their mode of exercise
a fractal is a natural phenomenon or a mathematical set that exhibits a repeating pattern that displays at every scale it is also known as expanding symmetry or evolving symmetry if the replication is exactly the same at every scale it is called a self similar pattern an example of this is the menger sponge fractals can also be nearly the same at different levels this latter pattern is illustrated in the fractals also include the idea of a detailed pattern that repeats itself fractals are different from other geometric figures because of the way in which they scale doubling the edge lengths of a polygon multiplies its area by four which is two the ratio of the new to the old side length raised to the power of two the dimension of the space the polygon resides in likewise if the radius of a sphere is doubled its volume scales by eight which is two the ratio of the new to the old radius to the power of three the dimension that the sphere resides in but if a fractal s one dimensional lengths are all doubled the spatial content of the fractal scales by a power that is not necessarily an integer this power is called the fractal dimension of the fractal and it usually exceeds the fractal s topological dimension as mathematical equations fractals are usually nowhere differentiable an infinite fractal curve can be conceived of as winding through space differently from an ordinary line still being a 1 dimensional line yet having a fractal dimension indicating it also resembles a surface the mathematical of fractals have been traced throughout the years as a formal path of published works starting in the 17 th century with notions of recursion then moving through increasingly rigorous mathematical treatment of the concept to the study of continuous but not differentiable functions in the 19 th century by the seminal work of bernard bolzano bernhard riemann and karl weierstrass and on to the coining of the word fractal in the 20 th century with a subsequent burgeoning of interest in fractals and computer based modelling in the 20 th century the term fractal was first used by mathematician benoît mandelbrot in 1975 mandelbrot based it on the latin frāctus meaning broken or fractured and used it to extend the concept of theoretical fractional dimensions to geometric patterns in nature there is some disagreement amongst authorities about how the concept of a fractal should be formally defined mandelbrot himself summarized it as beautiful damn hard increasingly unuseful that s fractals the general consensus is that theoretical fractals are infinitely self similar iterated and detailed mathematical constructs having fractal dimensions of which many examples have been formulated and studied in great depth fractals are not limited to geometric patterns but can also describe processes in time fractal patterns with various degrees of self similarity have been rendered or studied in images structures and sounds and found in and fractals are of particular relevance in the field of chaos theory since the graphs of most chaotic processes are fractal fractals are also observed from space here
fractional distillation is the separation of a mixture into its component parts or fractions separating chemical compounds by their boiling point by heating them to a temperature at which one or more fractions of the compound will vaporize it uses distillation to fractionate generally the component parts have boiling points that differ by less than 25 ° c from each other under a pressure of one atmosphere if the difference in boiling points is greater than 25 ° c a simple distillation is typically used
in physics fractionalization is the phenomenon whereby the quasiparticles of a system cannot be constructed as combinations of its elementary constituents one of the earliest and most prominent examples is the fractional quantum hall effect where the constituent particles are electrons but the quasiparticles carry fractions of the electron charge fractionalization can be understood as deconfinement of quasiparticles that together are viewed as comprising the elementary constituents in the case of spin – charge separation for example the electron can be viewed as a bound state of a spinon and a chargon which under certain conditions can become free to move separately
a fracture is the separation of an object or material into two or more pieces under the action of stress the fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid if a displacement develops perpendicular to the surface of displacement it is called a normal tensile crack or simply a crack if a displacement develops tangentially to the surface of displacement it is called a shear crack slip band or dislocation fracture strength or breaking strength is the stress when a specimen fails or fractures the word fracture is often applied to bones of living creatures i e a bone fracture or to crystalline materialss such as gemstones or metal sometimes individual crystals fracture without the structure actually separating into two or more pieces depending on the substance a fracture reduces strength most substances or inhibits transmission of waves such as light optical crystals a detailed understanding of how fracture occurs in materials may be assisted by the study of fracture mechanics
fracture blisters occur on skin overlying a fractured bone and fractures complicated by the development of overlying blisters remain a clinical dilemma in orthopedics fracture blisters are tense vesicles or bullae that arise on markedly swollen skin directly overlying a fracture fracture blisters pop up in trauma patients occasionally a fracture blister typically occurs near fractures where the skin has little subcutaneous tissue between it and bone these include elbows knees ankles and wrists they tend to complicate fracture management because they interfere with splinting casting and incision planning for open reduction procedures they can appear anytime within a few hours of injury to 2 – 3 weeks later these blisters are thought to be caused by shearing forces applied at the time of injury there are two types described based on their color clear fluid and hemorrhagic the difference lies in the level of the shear clear fluid blisters have separated within the epidermis and hemorrhagic blisters separate at the dermal epidermal junction the clinical difference is healing time clear blisters take about 12 days and hemorrhagic blisters heal in about 16 days the decision to pop the blisters in order to treat the fracture or wait for them to heal first usually hinges on the preferences of the orthopaedic surgeon as there is a lack of data on what treatment is ideal waiting delays care an average of 7 days and longer for tibial plateau and calcaneal fractures operating immediately anecdotally increases wound infection rates
fragile x associated tremor ataxia syndrome fxtas is a late onset neurodegenerative disorder associated with problems of movement memory and the autonomic nervous system it is related to the disease fragile x syndrome although fxtas is a clinically distinct syndrome in fragile x syndrome fxs the fragile x mental retardation 1 gene fmr 1 is silenced in fxtas fmr 1 is overexpressed and interferes with brain function both fxs and fxtas are caused by a trinucleotide repeat expansion in fmr 1 this cgg repeat expansion is smaller in fxtas the disease only occurs in individuals with a fragile x premutation it most often occurs in men but can present in women there is no cure for fxtas but several of the symptoms can be managed with medication
fragile x syndrome fxs is a genetic disorder symptoms often include mild to moderate intellectual disability physical features may include a long and narrow face large ears flexible fingers and large testicles about a third of people have features of autism such as problems with social interactions and delayed speech hyperactivity is common and seizures occur in about 10 males are usually more affected than females fragile x syndrome is typically due to the expansion of the cgg triplet repeat within the fragile x mental retardation 1 fmr 1 gene on the x chromosome this results in a failure to express the fragile x mental retardation protein fmrp which is required for normal neural development depending on the length of the cgg repeat an allele may be classified as normal unaffected by the syndrome a premutation at risk of fragile x associated disorders or full mutation usually affected by the syndrome a diagnosis of fragile x syndrome is made through genetic testing to determine the number of cgg repeats testing for premutation carriers may allow for genetic counseling there is no medication that has a benefit specifically for fragile x syndrome medications are commonly used to treat symptoms of attention deficit and hyperactivity anxiety and aggression supportive management is important in optimizing functioning in individuals with fragile x syndrome and may involve speech therapy occupational therapy and individualized educational and behavioral programs fragile x syndrome occurs in about 1 in 4 000 males and 1 in 8 000 females the first complete dna sequence of the repeat expansion in someone with the full mutation was generated by scientists in 2012 using smrt sequencing
the fragile base class problem is a fundamental architectural problem of object oriented programming systems where base classes superclasses are considered fragile because seemingly safe modifications to a base class when inherited by the derived classes may cause the derived classes to malfunction the programmer cannot determine whether a base class change is safe simply by examining in isolation the methods of the base class one possible solution is to make instance variables private to their defining class and force subclasses to use accessors to modify superclass states a language could also make it so that subclasses can control which inherited methods are exposed publicly these changes prevent subclasses from relying on implementation details of superclasses and allow subclasses to expose only those superclass methods that are applicable to themselves another alternative solution could be to have an interface instead of superclass the fragile base class problem has been blamed on open recursion dynamic dispatch of methods on a href mediawiki index php title this computer programming title this computer programming this a with the suggestion that invoking methods on this default to closed recursion static dispatch early binding rather than open recursion dynamic dispatch late binding only using open recursion when it is specifically requested external calls not using this would be dynamically dispatched as usual
in computer storage fragmentation is a phenomenon in which storage space is used inefficiently reducing capacity or performance and often both the exact consequences of fragmentation depend on the specific system of storage allocation in use and the particular form of fragmentation in many cases fragmentation leads to storage space being wasted and in that case the term also refers to the wasted space itself for other systems e g the fat file system the space used to store given data e g files is the same regardless of the degree of fragmentation from none to extreme there are three different but related forms of fragmentation external fragmentation internal fragmentation and data fragmentation which can be present in isolation or conjunction fragmentation is often accepted in return for improvements in speed or simplicity occur for other resources such as processors see below
in physics a fragmentation function is a probability function it is used to find the probability density or distribution of fragmented mesons in hadron hadron collisions it is important in the physics of deep inelastic scattering
fragmentation of memory is a memory disorder in which the patient is unable to attach memories to specific locations or times the impaired person can remember events but cannot pinpoint when the events happened either absolutely or in relation to other events this can occur even for relatively recent events the impaired person usually suffers from physical damage to or underdevelopment of the hippocampus this may be due to a genetic disorder or be the result of trauma such as post traumatic stress disorder brain dysfunction often has other related consequences such as oversensitivity to some stimuli impulsiveness lack of direction in life occasional aggressiveness a distorted perception of oneself and impaired ability to empathize with others which is usually masked there is frequently a link between dissociative disorders and memory fragmentation fragmentation of memory is common in two dissociative disorders dissociative or psychogenic amnesia is not to be confused with general amnesia in which the sufferer is unable to recall whole periods of time perhaps of several years duration in the dissociative version there is failure to recall specific events usually involving memories pertaining to the trauma itself in particular the disorder also relates to the emotional state of the mind upon experiencing trauma so that at times while the person will be able to remember the specifics of the events date time location people involved etc the strong emotional ties to the experience become fragmented in the creation of the memory dissociative fugue normally revolves around a specific journey taken by the person suffering from the disorder they can travel great distances and have no recollection of having done so these unremembered trips are usually the result of the individual trying to escape an unbearable situation and many times while traveling the person unknowingly suffers some degree of identity distortion or even assumes a completely new identity one of the unique characteristics of this disorder is that upon completing the trip the sufferer normally remembers it and all the details associated with it but while the events are happening s he has no recollection of time passing or where s he physically is
frailty is a common geriatric syndrome that embodies an elevated risk of catastrophic declines in health and function among older adults frailty is a condition associated with ageing and it has been recognized for centuries as described by shakespeare in as you like it the sixth age shifts into the lean and slipper ’ d pantaloon with spectacles on nose and pouch on side his youthful hose well sav ’ d a world too wide for his shrunk shank … the shrunk shank is a result of loss of muscle with aging it is also a marker of a more widespread syndrome of frailty with associated weakness slowing decreased energy lower activity and when severe unintended weight loss as a population ages a central focus of geriatricians and public health practitioners is to understand and then beneficially intervene on the factors and processes that put elders at such risk especially the increased vulnerability to stressors e g extremes of heat and cold infection injury or even changes in medication that characterizes many older adults
fraley syndrome is a condition where the superior infundibulum of the upper calyx of the kidney is obstructed by the crossing renal upper or middle section artery branch causing distension and dilatation of the calyx and presenting clinically as haematuria and nephralgia ipsilateral flank pain the condition was first described by urologist elwin e fraley in 1966 and can be treated surgically which might be necessary in symptomatic disease another possible cause for similar hydronephrosis is megacalicosis for which surgery is considered inappropriate
in the reception of framed data a frame slip is the loss of synchronization between a received frame and the receiver clock signal causing a frame misalignment event and resulting in the loss of the data contained in the received frame a frame slip should not be confused with a dropped frame where synchronization is not lost as in the case of buffer overflow for example
franceschetti – klein syndrome also known as mandibulofacial dysostosis is a syndrome that includes palpebral antimongoloid fissures hypoplasia of the facial bones macrostomia vaulted palate malformations of both the external and internal ear buccal auricular fistula abnormal development of the neck with stretching of the cheeks accessory facial fissures and skeletal deformities it is sometimes equated with treacher collins syndrome
francis 1 st is an american sterling silver tableware pattern introduced in 1906 named after king francis i of france
frank s sign or frank sign is a diagonal ear lobe crease elc extending diagonally from the tragus across the lobule to the rear edge of the auricle the sign is named after dr sanders t frank it has been hypothesised that frank s sign is indicative of cardiovascular disease and or diabetes some studies have described frank s sign as a marker of cardiovascular disease but not linked to the severity of the condition in contrast other studies have rebutted any association between frank s sign and coronary artery disease in diabetics there have also been reported cases of frank s sign assisting in the diagnosis of cerebral infarctions a link between frank s sign and premature aging and the loss of dermal and vascular fibers has also been hypothesized however researchers do agree that these creases have no predictive value in native american indian and asian patients some studies have focused upon bilateral elc
the frank – caro process also called cyanamide process is the nitrogen fixation reaction of calcium carbide with nitrogen gas in a reactor vessel at about 1 000 ° c the reaction is exothermic and self sustaining once the reaction temperature is reached originally the reaction took place in large steel cylinders with an electrical resistance element providing initial heat to start the reaction modern production uses rotating ovens the synthesis produces a solid mixture of calcium cyanamide cacn 2 and carbon cac 2 n 2 → cacn 2 c
frank ter haar syndrome fths also known as ter haar syndrome is a rare disease characterized by abnormalities that affect bone heart and eye development children born with the disease usually die very young
fraser syndrome also known as meyer schwickerath s syndrome fraser françois syndrome or ullrich feichtiger syndrome is an autosomal recessive congenital disorder fraser syndrome is named for the geneticist george r fraser who first described the syndrome in 1962
frasier syndrome is a urogenital anomaly associated with the wt 1 wilms tumor 1 gene gene it was first characterized in 1964
freckles sometimes called ephelides singular ephelis are clusters of concentrated melaninized cells which are most easily visible on people with a fair complexion freckles do not have an increased number of the melanin producing cells melanocytes but instead have melanocytes that overproduce melanin granules melanosomes changing the coloration of the outer skin cells called keratinocytes as such freckles are different from lentigines and moles
in mathematics the fredholm determinant is a complex valued function which generalizes the determinant of a matrix it is defined for bounded operators on a hilbert space which differ from the identity operator by a trace class operator the function is named after the mathematician erik ivar fredholm fredholm determinants have had many applications in mathematical physics the most celebrated example being gábor szegő s limit formula proved in response to a question raised by lars onsager and c n yang on the spontaneous magnetization of the ising model
free living amoebae or fla in the amoebozoa group are important causes of disease in humans and animals naegleria fowleri is sometimes included in the group free living amoebae and it causes a condition traditionally called primary amoebic meningoencephalitis however naegleria is now considered part of the excavata not the amoebozoa and is considered to be much more closely related to leishmania and trypanosoma
free radical addition is an addition reaction in organic chemistry involving free radicals the addition may occur between a radical and a non radical or between two radicals the basic steps with examples of the free radical addition also known as radical chain mechanism are initiation by a radical initiator a radical is created from a non radical precursor chain propagation a radical reacts with a non radical to produce a new radical species chain termination two radicals react with each other to create a non radical species free radical reactions depend on a reagent having a relatively weak bond allowing it to homolyse to form radicals often with heat or light reagents without such a weak bond would likely proceed via a different mechanism an example of an addition reaction involving aryl radicals is the meerwein arylation
free running sleep is a sleep pattern that is not adjusted entrained to the 24 hour cycle in nature nor to any artificial cycle it occurs as the sleep disorder non 24 hour sleep wake disorder or artificially as part of experiments used in the study of circadian and other rhythms in biology study subjects are shielded from all time cues often by a constant light protocol by a constant dark protocol or by the use of light dark conditions to which the organism cannot entrain such as the ultrashort protocol of one hour dark and two hours light also limited amounts of food may be made available at short intervals so as to avoid entrainment to mealtimes subjects are thus forced to live by their internal circadian clocks
in telecommunication free space path loss fspl is the loss in signal strength of an electromagnetic wave that would result from a line of sight path through free space usually air with no obstacles nearby to cause reflection or diffraction it is defined in standard definitions of terms for antennas ieee std 145 1983 as the loss between two isotropic radiators in free space expressed as a power ratio usually it is expressed in db although the ieee standard does not say that so it assumes that the antenna gain is a power ratio of 1 0 or 0 db it does not include any loss associated with hardware imperfections or the effects of any antenna gains a discussion of these losses may be found in the article on link budget the fspl is rarely used standalone but rather as a part of the friis transmission equation which includes the gain of antennas
in economics free entry is a condition in which firms can freely enter the market for an economic good by establishing production and beginning to sell the product in most markets this condition is present only in the long run free entry is part of the perfect competition assumption that there are an unlimited number of buyers and sellers in a market in conditions in which there is not a natural monopoly caused by unlimited economies of scale free entry prevents any existing firm from maintaining a monopoly which would restrict output and charge a higher price than a multi firm market would free entry is usually accompanied by free exit under which condition firms that are incurring losses such as would happen if there are too many firms producing the product so that each is producing too little to be at its minimum efficient scale can readily leave the market however exiting a market may involve abandonment costs
free variation in linguistics is the phenomenon of two or more sounds or forms appearing in the same environment without a change in meaning and without being considered incorrect by native speakers
free will is the ability to choose between different possible courses of action it is closely linked to the concepts of responsibility praise guilt sin and other judgments which apply only to actions that are freely chosen it is also connected with the concepts of advice persuasion deliberation and prohibition traditionally only actions that are freely willed are seen as deserving credit or blame there are numerous different concerns about threats to the possibility of free will varying by how exactly it is conceived which is a matter of some debate some conceive free will to be the capacity to make choices in which the outcome has not been determined by past events determinism suggests that only one course of events is possible which is inconsistent with the existence of such free will this problem has been identified in ancient greek philosophy and remains a major focus of philosophical debate this view that conceives free will to be incompatible with determinism is called incompatibilism and encompasses both metaphysical libertarianism the claim that determinism is false and thus free will is at least possible and hard determinism the claim that determinism is true and thus free will is not possible it also encompasses hard incompatibilism which holds not only determinism but also its negation to be incompatible with free will and thus free will to be impossible whatever the case may be regarding determinism in contrast compatibilists hold that free will is compatible with determinism some compatibilists even hold that determinism is necessary for free will arguing that choice involves preference for one course of action over another requiring a sense of how choices will turn out compatibilists thus consider the debate between libertarians and hard determinists over free will vs determinism a false dilemma different compatibilists offer very different definitions of what free will even means and consequently find different types of constraints to be relevant to the issue classical compatiblists considered free will nothing more than freedom of action considering one free of will simply if had one counterfactually wanted to do otherwise one could have done otherwise without physical impediment contemporary compatibilists instead identify free will as a psychological capacity such as to direct one s behavior in a way responsive to reason and there are still further different conceptions of free will each with their own concerns sharing only the common feature of not finding the possibility of determinism a threat to the possibility of free will
freeman – sheldon syndrome fss also termed distal arthrogryposis type 2 a da 2 a craniocarpotarsal dysplasia or dystrophy cranio carpo tarsal syndrome windmill vane hand syndrome or whistling face syndrome was originally described by freeman and sheldon in 1938 freeman – sheldon syndrome is a rare form of multiple congenital contracture mcc syndromes arthrogryposes and is the most severe form of distal arthrogryposis da
freezer burn is a condition that occurs when frozen food has been damaged by dehydration and oxidation due to air reaching the food it is generally caused by food not being securely wrapped in air tight packaging freezer burn appears as grayish brown leathery spots on frozen food and occurs when air reaches the food s surface and dries the product color changes result from chemical changes in the food s pigment freezer burn does not make the food unsafe it merely causes dry spots in foods provided that the freezer burns are removed before cooking the food remains usable and edible
freezing behavior or the freeze response is a reaction to specific stimuli most commonly observed in prey animals when a prey animal has been caught and completely overcome by the predator it may still be possible for the prey to escape by feigning death so that the predator stops the attack studies typically assess a conditioned freezing behavior response to stimuli that typically or innately do not cause fear such as a tone or shock freezing behavior is most easily characterized by changes in blood pressure and lengths of time in crouching position but it also is known to cause changes such as shortness of breath increased heart rate sweating or choking sensation however since it is difficult to measure these sympathetic responses to fear stimuli studies are typically confined to simple crouching times a response to stimuli typically is said to be a fight or flight but is more completely described as fight flight or freeze in addition freezing is observed to occur before or after a fight or flight response
the fregoli delusion or the delusion of doubles is a rare disorder in which a person holds a delusional belief that different people are in fact a single person who changes appearance or is in disguise the syndrome may be related to a brain lesion and is often of a paranoid nature with the delusional person believing themselves persecuted by the person they believe is in disguise a person with the fregoli delusion can also inaccurately recall places objects and events this disorder can be explained by associative nodes the associative nodes serve as a biological link of information about other people with a particular familiar face to the patient this means that for any face that is similar to a recognizable face to the patient the patient will recall that face as the person they know the fregoli delusion is classed both as a monothematic delusion since it only encompasses one delusional topic and as a delusional misidentification syndrome dms a class of delusional beliefs that involves misidentifying people places or objects like capgras delusion psychiatrists believe it is related to a breakdown in normal face perception
freiberg disease also known as a freiberg infraction is a form of avascular necrosis in the metatarsal it generally develops in the second metatarsal but can occur in any metatarsal physical stress causes repeated microfractures where the middle of the metatarsal meets the growth plate these restrict circulation to the end of the metatarsal causing the necrosis it is an uncommon condition occurring most often in young women athletes and those with abnormally long metatarsals approximately 80 of those diagnosed are women initial treatment is generally 4 – 6 weeks of limited activity often with crutches or orthotics in rare cases surgery is necessary to reduce the bone mass of the metatarsal the condition was first described by dr alfred h freiberg in 1914 he initially thought the condition was caused by acute physical trauma which is why it was initially called an infraction
fremitus is a vibration transmitted through the body in common medical usage it usually refers to assessment of the lungs by either the vibration intensity felt on the chest wall tactile fremitus and or heard by a stethoscope on the chest wall with certain spoken words vocal fremitus although there are several other types
french migration to the united kingdom is a phenomenon that has occurred at various points in history the norman conquest of england by william the conqueror in 1066 resulted in the arrival of french aristocracy while in the 16 th and 17 th centuries protestant huguenots fled religious persecution to east london other waves but less likely to have put down permanent roots are associated with monasticism particularly post conquest benedictines and cistercians aristocracy fleeing the french revolution expulsion of religious orders by third republic france and current economic migrants seeking employment opportunities not necessarily open to their british counterparts in france the 2011 uk census recorded 137 862 french born people living in the uk almost half of these were resident in the capital london many more british people have french ancestry french remains the foreign language most learned by britons it has traditionally been spoken as a second language by the country s educated classes and its popularity is reinforced by the close geographical proximity between great britain and france
french school holidays are the periods when schools in france and all the pupils in them have a holiday the dates are fixed nationally by the ministry of education for a period of three years holiday dates are given as a saturday date after classes as some schools have lessons on saturday mornings and return on a monday morning the fixed dates can lead to over crowding in tourist resorts such as the mediterranean coast and the ski resorts and price increases and availability problems in travel and accommodations to alleviate this problem holiday schedules for the winter and spring holidays in february and april respectively are staggered by dividing the country into three zones nevertheless the synchronized school holiday schedules still cause some crowding effects as families head to popular holiday locations especially in the summer at the beginning and end of the months in july and august when the traffic jams are a regular feature of the news bulletins
a frenkel defect is a type of defect in crystalline solids wherein an atom is displaced from its lattice position to an interstitial site creating a vacancy at the original site and an interstitial defect at the new location within the same element without any changes in chemical properties
frenulectomy of the penis is a surgical procedure for cutting and removal of the frenulum of prepuce of penis to correct a condition known as frenulum breve this condition prevents the full retraction of the foreskin with or without an erection it is a simple and normally painless procedure that is performed in a urologist s office first the physician applies a local anesthetic such as lidocaine prilocaine cream on the frenulum and surrounding area in half hour he checks to see if the patient has any feeling there if not he proceeds with the procedure otherwise he may recommend that it be performed in a hospital with stronger anesthesia once the frenulum is cut the physician applies stitches to close the wound the patient is given a prescription for pain killers to take in case there is pain afterwards but usually the only discomfort is from the pricking of the stitches on the foreskin once the stitches are removed in about a week normal sexual activity can resume
frenuloplasty is the surgical alteration of a frenulum when its presence restricts range of motion between interconnected tissues two of the common sites for a frenuloplasty are frenuloplasty of tongue frenuloplasty of prepuce of penis
frenulum breve or short frenulum is a condition in which the frenulum of the penis which is an elastic band of tissue under the glans penis that connects to the foreskin and helps contract it over the glans is too short and thus restricts the movement of the foreskin the frenulum should normally be sufficiently long and supple to allow for the full retraction of the foreskin so that it lies smoothly back on the shaft of the erect penis the penile frenulum is comparable to the tongue s frenulum between the tongue s lower surface and the lower jaw or the frenulum between the upper lip and the outside of the upper gum
frequency agility is the ability of a radar system to quickly shift its operating frequency to account for atmospheric effects jamming mutual interference with friendly sources or to make it more difficult to locate the radar broadcaster through radio direction finding the term can also be applied to other fields including lasers or traditional radio transceivers using frequency division multiplexing but it remains most closely associated with the radar field and these other roles generally use the more generic term frequency hopping
in computer science frequent subtree mining is the problem of finding all patterns in a given database whose support a metric related to its number of occurrences in other subtrees is over a given threshold it is a more general form of the maximum agreement subtree problem
a freudian slip also called parapraxis is an error in speech memory or physical action that is interpreted as occurring due to the interference of an unconscious subdued wish or internal train of thought the concept is part of classical psychoanalysis classical examples of parapraxes involve slips of the tongue and of the pen but psychoanalytic theory also embraces misreadings mishearings temporary forgettings and the mislaying and losing of objects
frey s syndrome also known as baillarger ’ s syndrome dupuy ’ s syndrome auriculotemporal syndrome or frey baillarger syndrome is a rare neurological disorder resulting from damage to or near the parotid glands responsible for making saliva and from damage to the auriculotemporal nerve often from surgery the symptoms of frey s syndrome are redness and sweating on the cheek area adjacent to the ear see focal hyperhidrosis they can appear when the affected person eats sees dreams thinks about or talks about certain kinds of food which produce strong salivation observing sweating in the region after eating a lemon wedge may be diagnostic
friction blisters are a skin condition that may occur at sites of combined pressure and friction and may be enhanced by heat moisture or cotton socks friction blisters are characterized by vesicles or bullae
in fluid flow friction loss or skin friction is the loss of pressure or “ head ” that occurs in pipe or duct flow due to the effect of the fluid s viscosity near the surface of the pipe or duct in mechanical systems such as internal combustion engines the term refers to the power lost in overcoming the friction between two moving surfaces a different phenomenon
the friedländer synthesis is a chemical reaction of 2 aminobenzaldehydes with ketones to form quinoline derivatives it is named after german chemist paul friedländer 1857 – 1923 the friedländer synthesis this reaction has been catalyzed by trifluoroacetic acid toluenesulfonic acid iodine and lewis acids several reviews have been published
the friedman – savage utility function is the utility function postulated in the theory that milton friedman and leonard j savage put forth in their 1948 paper they argued that the curvature of an individual s utility function differs based upon the amount of wealth the individual has this variably curving utility function would thereby explain why an individual is risk loving when he has more wealth e g by playing the lottery and risk averse when he is poorer e g by buying insurance the function has been used widely including in the field of economic history to explain why social gambling did not necessarily mean that society had gone gambling mad
friedreich s ataxia is an autosomal recessive inherited disease that causes progressive damage to the nervous system it manifests in initial symptoms of poor coordination such as gait disturbance it can also lead to scoliosis heart disease and diabetes but does not affect cognitive function the disease progresses until a wheelchair is required for mobility its incidence in the general population is roughly 1 in 50 000 the particular genetic mutation expansion of an intronic gaa triplet repeat in the fxn gene leads to reduced expression of the mitochondrial protein frataxin over time this deficiency causes the aforementioned damage as well as frequent fatigue due to effects on cellular metabolism the ataxia of friedreich s ataxia results from the degeneration of nervous tissue in the spinal cord in particular sensory neurons essential through connections with the cerebellum for directing muscle movement of the arms and legs the spinal cord becomes thinner and nerve cells lose some of their myelin sheath the insulating covering on some nerve cells that helps conduct nerve impulses the condition is named after the german physician nikolaus friedreich who first described it in the 1860 s
the friendship paradox is the phenomenon first observed by the sociologist scott l feld in 1991 that most people have fewer friends than their friends have on average it can be explained as a form of sampling bias in which people with greater numbers of friends have an increased likelihood of being observed among one s own friends in contradiction to this most people believe that they have more friends than their friends have the same observation can be applied more generally to social networks defined by other relations than friendship for instance most people s sexual partners have had on the average a greater number of sexual partners than they have
the fries rearrangement named for the german chemist karl theophil fries is a rearrangement reaction of a phenolic ester to a hydroxy aryl ketone by catalysis of lewis acids it involves migration of an acyl group of phenolic ester to benzene ring the reaction is ortho and para selective and one of the two products can be favoured by changing reaction conditions such as temperature and solvent
friese freedom or freedom of the frisians frisian fryske frijheid dutch friese vrijheid was the absence of feudalism and serfdom in frisia the area that was originally inhabited by the frisians historical frisia included the modern provinces of friesland and groningen and the area of west friesland in the netherlands and east friesland in germany during the period of frisian freedom the area did not have a sovereign lord who owned and administered the land the freedom of the frisians developed in the context of ongoing disputes over the rights of local nobility
frisson french for shiver is a sensation somewhat like shivering usually caused by stimuli it is typically expressed as an overwhelming emotional response combined with piloerection goosebumps stimuli that produce a response are specific to the individual frisson is of short duration usually no more than 4 – 5 seconds usually pleasurable typical stimuli include loud passages of music and passages that violate some level of musical expectation it has been shown that during frisson the skin of the lower back flexes and shivers rise upward and inward from the shoulders up the neck and may extend to the cheeks and scalp the face may become flush hair follicles experience piloerection this frequently occurs in a series of waves moving up the back in rapid succession the frissoner usually feels the experience as involuntary it has been shown that some experiencing musical frisson report reduced excitement when under administration of naloxone an opioid receptor antagonist suggesting musical frisson gives rise to endogenous opioid peptides similar to other pleasurable experiences frisson may be enhanced by the amplitude of the music and the temperature of the environment cool listening rooms and movie theaters may enhance the experience
the fritsch – buttenberg – wiechell rearrangement named for paul ernst moritz fritsch 1859 – 1913 wilhelm paul buttenberg and heinrich g wiechell is a chemical reaction whereby a 1 1 diaryl 2 bromo alkene rearranges to a 1 2 diaryl alkyne by reaction with a strong base such as an alkoxide the fritsch buttenberg wiechell rearrangement this rearrangement is also possible with alkyl substituents
frog skin is a battledress camouflage pattern with mottle and disruptive coloration to blend into the environment similar to a frog s crypsis skin
in the dungeons dragons fantasy role playing game the froghemoth is a type of aberration
froin s syndrome – coexistence of xanthochromia high protein level and marked coagulation of cerebrospinal fluid csf it is caused by meningeal irritation e g during spinal meningitis and csf flow blockage by tumour mass or abscess stagnation of the csf within the thecal sac facilitates exudation from the tumour itself and activation of coagulation factors clinical test formerly used for evaluation of spinal stenosis was queckenstedt s maneuver nowadays an magnetic resonance imaging is applied it often shows the prolongation of t 1 and t 2 signal in csf caudal to a level of block phenomenon named after georges froin 1874 – 1932 a french physician who first described it
frontal lobe disorder is an impairment of the frontal lobe that occurs due to disease or head trauma the frontal lobe of the brain plays a key role in higher mental functions such as motivation planning social behaviour and speech production a frontal lobe syndrome can be caused by a range of conditions including head trauma tumours degenerative diseases neurosurgery and cerebrovascular disease frontal lobe impairment can be detected by recognition of typical clinical signs use of simple screening tests and specialist neurological testing
frontal lobe epilepsy or fle is a neurological disorder that is characterized by brief recurring seizures that arise in the frontal lobes of the brain often while the patient is sleeping it is the second most common type of epilepsy after temporal lobe epilepsy tle and is related to the temporal form by the fact that both forms are characterized by the occurrence of partial focal seizures partial seizures occurring in the frontal lobes can occur in one of two different forms either simple partial seizures that do not affect awareness or memory or complex partial seizures that affect awareness or memory either before during or after a seizure the symptoms and clinical manifestations of frontal lobe epilepsy can differ depending on which specific area of the frontal lobe is affected the onset of a seizure may be hard to detect since the frontal lobes contain and regulate many structures and functions about which relatively little is known due to the lack of knowledge surrounding the functions associated with the frontal lobes seizures occurring in these regions of the brain may produce unusual symptoms which can often be misdiagnosed as a psychiatric disorder non epileptic seizure or a sleep disorder during the onset of a seizure the patient may exhibit abnormal body posturing sensorimotor tics or other abnormalities in motor skills in some cases uncontrollable laughing or crying may occur during a seizure afflicted persons may or may not be aware that they are behaving in an abnormal manner depending on the patient and type of seizure a brief period of confusion known as a postictal state may sometimes follow a seizure occurring in the frontal lobes however these postictal states are often undetectable and generally do not last as long as the periods of confusion following seizures that occur in the temporal lobes there are many different causes of frontal lobe epilepsy ranging from genetics to head trauma that result in lesions in the frontal lobes although frontal lobe epilepsy is often misdiagnosed tests such as prolonged eeg monitoring and or a mri scan of the frontal lobes can be administered in order to reveal the presence of a tumor or vascular malformation unlike most epileptic eegs the abnormalities in fle eegs precede the physical onset of the seizure and aid in localization of the seizure s origin medications such as anti epileptic drugs can typically control the onset of seizures however if medications are ineffective the patient may undergo surgery to have focal areas of the frontal lobe removed
frontonasal dysplasia fnd also known as median cleft face syndrome frontonasal dysostosis frontonasal malformation or tessier cleft number 0 14 is a congenital malformation of the midface for the diagnosis of fnd a patient should present at least two of the following characteristics hypertelorism an increased distance between the eyes a wide nasal root vertical midline cleft of the nose and or upper lip cleft of the wings of the nose malformed nasal tip encephalocele an opening of the skull with protrusion of the brain or v shaped hair pattern on the forehead the cause of fnd remains unknown fnd seems to be sporadic random and multiple environmental factors are suggested as possible causes for the syndrome however in some families multiple cases of fnd were reported which suggests a genetic cause of fnd
frontotemporal dementia ftd is the clinical presentation of frontotemporal lobar degeneration which is characterized by progressive neuronal loss predominantly involving the frontal and or temporal lobes and typical loss of over 70 of spindle neurons while other neuron types remain intact it was first described by arnold pick in 1892 and was originally called pick s disease a term now reserved for pick disease one specific type of frontotemporal dementia second only to alzheimer s disease ad in prevalence ftd accounts for 20 of young onset dementia cases signs and symptoms typically manifest in late adulthood more commonly between the ages of 55 and 65 approximately equally affecting men and women common signs and symptoms include significant changes in social and personal behavior apathy blunting of emotions and deficits in both expressive and receptive language currently there is no cure for ftd but there are treatments that help alleviate symptoms
frontotemporal dementia and parkinsonism linked to chromosome 17 ftdp 17 is an autosomal dominant neurodegenerative disorder and parkinson plus syndrome which has three cardinal features behavioral and personality changes cognitive impairment and motor symptoms ftdp 17 was defined during the international consensus conference in ann arbor michigan in 1996
frontotemporal lobar degeneration ftld is a pathological process that occurs in frontotemporal dementia it is characterized by atrophy in the frontal lobe and temporal lobe of the brain with sparing of the parietal and occipital lobes common proteinopathies that are found in ftld include the accumulation of tau proteins and tardbps mutations in the c 9 orf 72 gene have been established as a major genetic contribution of ftld although defects in the grn and mapt genes are also associated with it
frostbite or cold burn is the medical condition in which localized damage is caused to skin and other tissues due to freezing frostbite is most likely to happen in body parts farthest from the heart and those with large exposed areas the initial stages of frostbite are sometimes called frostnip
frosting is a decorative effect named after its resemblance to the appearance of frost it involves making very small marks in a surface so that it appears matt rather than polished and in glass opaque rather than optically transparent it is often used for glass for bathrooms and toilets but may be used on many materials and created by many processes
in fructose bisphosphatase deficiency there is not enough fructose bisphosphatase for gluconeogenesis to occur correctly glycolysis the breakdown of glucose will still work as it does not use this enzyme
fructose malabsorption formerly named dietary fructose intolerance dfi is a digestive disorder in which absorption of fructose is impaired by deficient fructose carriers in the small intestine s enterocytes this results in an increased concentration of fructose in the entire intestine occurrence in patients identified to be suffering symptoms of irritable bowel syndrome is not higher than occurrence in the normal population however due to the similarity in symptoms patients with fructose malabsorption often fit the profile of those with irritable bowel syndrome in some cases fructose malabsorption may be caused by several diseases which cause an intestinal damage such as celiac disease fructose malabsorption is not to be confused with hereditary fructose intolerance a potentially fatal condition in which the liver enzymes that break up fructose are deficient
a fruit allergy is a food allergy fruit allergies make up about ten percent of all food related allergies
the fruta del norte deposit is the largest gold deposits in ecuador and a world class discovery the deposit is located in the south east of the country in zamora chinchipe province details of the deposit can be found at originally named by bart wilson who worked with a regional team led by hendrik schloemann and initiated by keith barron of aurelian resources fdn was one of many anomalies that resulted from this regional program steve leary aurelian project manager later looked at the work done and was responsible for drilling the first successful hole on the target aurelian experienced a stock explosion once the preliminary findings were announced the company was taken over by kinross all exploration in the country was soon halted by ecuadorian presidential decree kinross negotiated unsuccessfully for a number of years with the government and in 2014 sold the project to lundin gold inc
fryns syndrome is an autosomal recessive multiple congenital anomaly syndrome that is usually lethal in the neonatal period fryns 1987 reviewed the syndrome
fuchs dystrophy pronounced fooks dis trə fe also known as fuchs corneal endothelial dystrophy or fced is a slowly progressing corneal dystrophy that usually affects both eyes and is slightly more common in women than in men although doctors can often see early signs of fuchs dystrophy in people in their 30 s and 40 s the disease rarely affects vision until people reach their 50 s and 60 s the condition was first described by austrian ophthalmologist ernst fuchs 1851 – 1930 after whom it is named in 1910 fuchs first reported 13 cases of central corneal clouding loss of corneal sensation and the formation of epithelial bullae which he labeled ‘ dystrophia epithelialis corneae ’ it was characterized by late onset slow progression decreased visual acuity in the morning lack of inflammation diffuse corneal opacity intense centrally and roughened epithelium with vesicle like features a shift to the understanding of fuchs ’ corneal endothelial dystrophy fced as primarily a disease of the corneal endothelium resulted after a number of observations in the 1920 s crystal like features of the endothelium were noted by kraupa in 1920 who suggested that the epithelial changes were dependent on the endothelium using a slit lamp vogt described the excrescences associated with fcd as drop like in appearance in 1921 in 1924 graves then provided an extremely detailed explanation of the endothelial elevations visible with slit lamp biomicroscopy a patient with unilateral epithelial dystrophy and bilateral endothelial changes was described by the friedenwalds in 1925 subsequent involvement of the second eye led them to emphasize that endothelial changes preceded epithelial changes as only a subset of patients with endothelial changes proceeded to epithelial involvement graves stated on 19 october 1925 to the new york academy of medicine that “ fuchs ’ epithelial dystrophy may be a very late sequel to severer cases of the deeper affection ”
the fuchs spot or sometimes forster fuchs retinal spot is a degeneration of the macula in case of high myopia it is named after the two persons who first described it ernst fuchs who described a pigmented lesion in 1901 and forster who described subretinal neovascularisation in 1862 the size of the spots are proportionate to the severity of the pathological myopia
fucosidosis is a rare lysosomal storage disorder in which the fuca 1 gene experiences mutations that severely reduce or stop the activity of the alpha l fucosidase enzyme the result is a buildup of complex sugars in parts of the body which leads to death fucosidosis is one of nine identified glycoprotein storage diseases the gene encoding the alpha fucosidase fuca 1 was found to be located to the short arm of chromosome 1 p 36 p 34 by carrit and co workers in 1982
a fuel element failure is a rupture in a nuclear reactor s fuel cladding that allows the nuclear fuel or fission products either in the form of dissolved radioisotopes or hot particles to enter the reactor coolant or storage water the de facto standard nuclear fuel is uranium dioxide or a mixed uranium plutonium dioxide this has a higher melting point than the actinide metals uranium dioxide resists corrosion in water and provides a stable matrix for many of the fission products however to prevent fission products such as the noble gases from leaving the uranium dioxide matrix and entering the coolant the pellets of fuel are normally encased in tubes of a corrosion resistant metal alloy normally zircaloy for water cooled reactors those elements are then assembled into bundles to allow good handling and cooling as the fuel fissions the radioactive fission products are also contained by the cladding and the entire fuel element can then be disposed of as nuclear waste when the reactor is refueled if however the cladding is damaged those fission products which are not immobile in the uranium dioxide matrix can enter the reactor coolant or storage water and can be carried out of the core into the rest of the primary cooling circuit increasing contamination levels there in the eu some work has been done in which fuel is overheated in a special research reactor named phebus during these experiments the emissions of radioactivity from the fuel are measured and afterwards the fuel is subjected to post irradiation examination pie to discover more about what happened to it it can be seen that the fuel has failed mechanically and has formed a pool near the bottom of the bundle the bottom of the bundle did not melt
fuel starvation and fuel exhaustion sometimes referred to as fuel depletion are problems that can affect internal combustion engines fuelled by either diesel kerosene petroleum or any other combustible liquid or gas if no fuel is available for an engine to burn it cannot function all modes of transport powered by such engines can be affected by this problem but the consequences are most significant when it occurs to aircraft in flight
fugue is a cryptographic hash function submitted by ibm to the nist hash function competition it was designed by shai halevi william e hall and charanjit s jutla fugue takes an arbitrary length message and compresses it down to a fixed bit length either 224 256 384 or 512 bits the hash functions for the different output lengths are called fugue 224 fugue 256 fugue 384 and fugue 512 the authors also describe a parametrized version of fugue a weak version of fugue 256 is also described using this parameterized version the selling point of fugue is the authors claimed proof that a wide range of current attack strategies based on differential cryptanalysis cannot be efficient against fugue it is also claimed to be competitive with the nist hash function sha 256 in both software and hardware efficiency achieving up to 36 2 cycles per byte on an intel family 6 model 15 xeon 5150 and up to 25 cycles per byte on an intel core 2 processor t 7700 on 45 nm core 2 processors e g t 9400 fugue 256 runs at 16 cycles per byte using sse 4 1 instructions on the newer westmere architectures 32 nm e g core i 5 fugue 256 runs at 14 cycles byte fugue s design starts from the hash function grindahl and like grindahl uses the s box from aes but it replaces the 4 × 4 column mixing matrix with a 16 × 16 super mix operation which greatly improves diffusion the super mix operation is however only slightly more computationally expensive to implement than the aes mixing strategy
dissociative fugue formerly fugue state or psychogenic fugue is a dsm 5 dissociative disorder it is a rare psychiatric disorder characterized by reversible amnesia for personal identity including the memories personality and other identifying characteristics of individuality the state is usually short lived ranging from hours to days but can last months or longer dissociative fugue usually involves unplanned travel or wandering and is sometimes accompanied by the establishment of a new identity it is no longer its own classification or diagnosis as it was in the dsm iv but is now a facet of dissociative amnesia according to the dsm 5 after recovery from fugue previous memories usually return intact because of this there is not normally any treatment necessary for people who have been in fugue states additionally an episode of fugue is not characterized as attributable to a psychiatric disorder if it can be related to the ingestion of psychotropic substances to physical trauma to a general medical condition or to other psychiatric conditions such as dissociative identity disorder delirium or dementia fugues are usually precipitated by a stressful episode and upon recovery there may be amnesia for the original stressor dissociative amnesia
the fujimoto – belleau reaction is a chemical reaction that forms cyclic α substituted α β unsaturated ketones from enol lactones the reaction is named after the two chemists george i fujimoto and bernard belleau the fujimoto belleau reaction the reaction is a grignard reaction followed by a h shift an enol keto tautomerisation and an aldol addition reaction the last step is an elimination aldol condensation reaction with an e 1 cb mechanism mechanism of the reaction
in mathematics fujita s conjecture is a problem in the theories of algebraic geometry and complex manifolds unsolved as of 2013 it is named after takao fujita who formulated it in 1985 in complex manifold theory the conjecture states that for a positive holomorphic line bundle l on a compact complex manifold m with canonical line bundle k then lmk is spanned by sections when m ≥ n 1 and is very ample when m ≥ n 2 where n is the complex dimension of m
in taiwan fukan chinese 副刊 pinyin fùkān pe̍h ōe jī hù khan are literary supplements in newspapers
in computational chemistry the fukui function or frontier function is a function that describes the electron density in a frontier orbital as a result of a small change in the total number of electrons the condensed fukui function or condensed reactivity indicator is the same idea but applied to an atom within a molecule rather than a point in three dimensional space the fukui function allows one to predict using density functional theory where the most electrophilic and nucleophilic sites of a molecule are
fukuyama congenital muscular dystrophy fcmd is a rare autosomal recessive form of muscular dystrophy weakness and breakdown of muscular tissue mainly described in japan but also identified in turkish and ashkenazi jewish patients fifteen cases were first described on 1960 by fukuyama fcmd mainly affects the brain eyes and muscles in particular the disorder affects development of the skeletal muscles leading to weakness and deformed appearances and brain development is blunted affecting cognitive functioning as well as social skills in 1995 the disorder was linked to mutations in a gene coding for the protein fukutin the fcmd gene fukuyama congenital muscular dystrophy is the second most prevalent form of muscular dystrophy in japan one out of every 90 people in japan is a heterozygous carrier
the fukuyama coupling is a coupling reaction taking place between a thioester and an organozinc halide in the presence of a palladium catalyst the reaction product is a ketone this reaction was discovered by tohru fukuyama et al in 1998 advantages are high chemoselectivity mild reaction conditions and the use of less toxic reagents fukuyama coupling one advantage of this method is that the reaction stops at the ketone and does not proceed to a tertiary alcohol in addition the protocol is compatible with functional groups such as ketones acetates sulfides aromatic bromides chlorides and aldehydes original fukuyama 1998 reaction the reaction interrupted has been used in the synthesis of biotin biotin total synthesis this reaction was preceded by the conceptually related fukuyama reduction
the fukuyama indole synthesis is a versatile tin mediated chemical reaction that results in the formation of 2 3 disubstituted indoles a practical one pot reaction that can be useful for the creation of disubstituted indoles most commonly tributyltin hydride is utilized as the reducing agent with azobisisobutyronitrile aibn as a radical initiator triethylborane can also be used as a radical initiator the reaction can begin with either an o isocyanostyrene or a 2 alkenylthioanilide derivative both forming the indole through radical cyclization via an alpha stannoimidoyl radical the r group can be a range of both basic and acidic sensitive functional groups such as esters thp ethers and beta lactams in addition the reaction is not stereo specific in that both the cis and trans isoform can be used to obtain the desired product fukuyama indole synthesis with either starting material
the fukuyama reduction is an organic reaction and an organic reduction in which a thioester is reduced to an aldehyde by a silyl hydride in presence of a catalytic amount of palladium this reaction was invented in 1990 by tohru fukuyama in the original scope of the reaction the silyl hydride was triethylsilane and the catalyst palladium on carbon the fukuyama reduction fukuyama reductions are used for the conversion of carboxylic acids as thioester precursor to aldehydes which is considered a difficult procedure because of the ease of secondary reduction to an alcohol
full spectrum light is light that covers the electromagnetic spectrum from infrared to near ultraviolet or all wavelengths that are useful to plant or animal life in particular sunlight is considered full spectrum even though the solar spectral distribution reaching earth changes with time of day latitude and atmospheric conditions full spectrum is not a technical term when applied to an electrical light bulb but rather a marketing term implying that the product emulates natural light products marketed as full spectrum may produce light throughout the entire spectrum but actually do not produce an even spectral distribution and may not even differ substantially from lights not marketed as full spectrum
fumarase deficiency or fumaric aciduria also known as polygamist down s is an autosomal recessive metabolic disorder characterized by a deficiency of the enzyme fumarate hydratase which is indicated by a buildup of fumaric acid in the urine
in mathematical analysis and applications in geometry applied mathematics engineering and natural sciences a function of a real variable is a function whose domain is the real numbers ℝ more specifically the subset of ℝ for which the function is defined the output also called the value of the function could be anything simple examples include a single real number or a vector of real numbers the function is vector valued vector valued functions of a single real variable occur widely in applied mathematics and physics particularly in classical mechanics of particles as well as phase paths of dynamical systems but we could also have a matrix of real numbers as the output the function is matrix valued and so on the output could also be other number fields such as complex numbers quaternions or even more exotic hypercomplex numbers
in mathematical analysis and applications in geometry applied mathematics engineering natural sciences and economics a function of several real variables or real multivariate function is a function with more than one argument with all arguments being real variables this concept extends the idea of a function of a real variable to several variables the input variables take real values while the output also called the value of the function may be real or complex however the study of the complex valued functions may be easily reduced to the study of the real valued functions by considering the real and imaginary parts of the complex function therefore unless explicitly specified only real valued functions will be considered in this article the domain of a function of several variables is the subset of ℝn for which the function is defined as usual the domain of a function of several real variables is supposed to contain an open subset of ℝn
in some programming languages function overloading or method overloading is the ability to create multiple methods of the same name with different implementations calls to an overloaded function will run a specific implementation of that function appropriate to the context of the call allowing one function call to perform different tasks depending on context for example dotask and dotask object o are overloaded methods to call the latter an object must be passed as a parameter whereas the former does not require a parameter and is called with an empty parameter field a common error would be to assign a default value to the object in the second method which would result in an ambiguous call error as the compiler wouldn t know which of the two methods to use another appropriate example would be a print object o method in this case one might like the method to be different when printing for example text or pictures the two different methods may be overloaded as print text object t print image object p if we write the overloaded print methods for all objects our program will print we never have to worry about the type of the object and the correct function call again the call is always print something
in computational complexity theory a function problem is a computational problem where a single output of a total function is expected for every input but the output is more complex than that of a decision problem that is it isn t just yes or no
functional disconnection is the disintegrated function in the brain in the absence of anatomical damage in distinction to physical disconnection of the cerebral hemispheres by surgical resection trauma or lesion the concept was first coined by gerry leisman and sroka solsi and bornstein applications have included alexia without agraphia dyslexia persistent vegetative state and minimally conscious state as well as autistic spectrum disorders functional disconnection is not a medically recognized condition
a functional disorder is a medical condition that impairs the normal function of a bodily process but where every part of the body looks completely normal under examination dissection or even under a microscope this stands in contrast to a structural disorder in which some part of the body can be seen to be abnormal or a psychosomatic disorder in which symptoms are caused by psychological or psychiatric illness definitions vary somewhat between fields of medicine generally the mechanism that causes a functional disorder is unknown poorly understood or occasionally unimportant for treatment purposes the brain or nerves are often believed to be involved it is common that a person with one functional disorder will have others
functional gastrointestinal disorders fgid include a number of separate idiopathic disorders which affect different parts of the gastrointestinal tract and involve visceral hypersensitivity and impaired gastrointestinal motility heightened mast cell activation is a common factor among all fgids that contributes to visceral hypersensitivity as well as epithelial neuromuscular and motility dysfunction
functional neurological symptom disorder fnsd is a condition in which patients experience neurological symptoms such as weakness movement disorders sensory symptoms and blackouts the brain of a patient with functional neurological symptom disorder is structurally normal but functions incorrectly in broad terms there is a problem with the patient s central nervous system which is not sending and receiving signals correctly other terms for functional neurological symptom disorder represent changing ideas and attitudes to these disorders and include functional neurological disorder fnd conversion disorder and psychogenic movement disorder non epileptic seizures the cause of functional neurological disorders is considered to be multifactorial which means many different factors can contribute to the development of the disorder with greater understanding of the brain most diseases including functional neurological disorders should be thought of as having biological psychological and social components the biopsychosocial disease model functional neurological disorders are common in neurological services accounting for up to one third of outpatient neurology clinic attendances and associated with as much physical disability and distress as other neurological disorders the diagnosis is made based on positive signs and symptoms in the history and examination during consultation of a neurologist see below assessment demonstrates that normal function of the nervous system is possible the best evidence for treatment for functional neurological disorders from recent studies suggest that physiotherapy and or psychological therapy can both be helpful depending on the individual patient physiotherapy is particularly helpful for patients with motor symptoms weakness gait disorders movement disorders and tailored cognitive behavioural therapy has the best evidence in patients with dissociative non epileptic attacks
a functional symptom is a medical symptom in an individual which is very broadly conceived as arising from a problem in nervous system functioning and not due to a structural or pathologically defined disease cause functional symptoms are increasingly viewed within a framework in which psychological physiological and biological factors should be considered to be relevant historically there has often been fierce debate about whether certain problems are predominantly related to an abnormality of structure disease or function abnormal nervous system functioning and what are at one stage posited to be functional symptoms are sometimes later reclassified as organic as investigative techniques improve thus on finding itself unable to discover effective treatments or physiological causes for symptoms the medical profession in explaining to itself these limitations of its own power over nature is of course subject to a temptation to minimize the explanatory role played by the many gaps in its own current scientific understanding and instead to grope for theories of psychosomatic aetiology to account for the physical symptoms that it cannot otherwise explain and cannot cure to caricature this reasoning i can t cure you you must be mad it is well established that psychosomatic symptoms are a real phenomenon so this potential explanation is often plausible not always easily refutable and can be reassuring at least for the doctor sometimes it is correct for example symptoms associated with migraine epilepsy schizophrenia multiple sclerosis stomach ulcers chronic fatigue syndrome lyme disease and many other conditions have all tended historically at first to be explained largely as physical manifestations of the sufferer s psychological state of mind until such time as new physiological knowledge is eventually gained at this point a part of the earlier reliance on psychological explanations often evaporates taking a long historical view doctors being human there seems little reason to suppose that this historical pattern of eventual correloction of earlier psychological misattribution of symptoms is yet become a thing of the past another specific example is functional constipation which may have psychological or psychiatric causes however one type of apparently functional constipation anismus may have a neurological physical basis whilst misdiagnosis of functional symptoms does occur in neurology for example this appears to occur no more frequently than of other neurological or psychiatric syndromes although in order to be quantified misdiagnosis has to be recognized as such which can be problematic in such a challenging field as medicine a common trend is to see functional symptoms and syndromes such as fibromyalgia irritable bowel syndrome and functional neurological symptoms such as functional weakness as symptoms in which both biological and psychological factors are relevant without one necessarily being dominant
functional weakness is weakness of an arm or leg due to the nervous system not working properly it is not caused by damage or disease of the nervous system patients with functional weakness experience symptoms of limb weakness which can be disabling and frightening such as problems walking or a ‘ heaviness ’ down one side dropping things or a feeling that a limb just doesn ’ t feel normal or ‘ part of them ’ functional weakness may also be described as dissociative motor disorder and less helpfully as conversion disorder to the patient and the doctor it often looks as if there has been a stroke or have symptoms of multiple sclerosis however unlike these conditions with functional weakness there is no permanent damage to the nervous system which means that it can get better or even go away completely the diagnosis should usually be made by a consultant neurologist so that other neurological causes can be excluded the diagnosis should be made on the basis of positive features in the history and the examination such as hoover s sign it is dangerous to make the diagnosis simply because tests are normal neurologists usually diagnose wrongly about 5 of the time which is the same for many other conditions many patients with functional weakness suffer from not being believed although psychological factors can be important they are not exclusively so and the problem is not made up or imagined patients with functional weakness are as disabled and distressed by their symptoms as patients with multiple sclerosis treatment involves understanding and believing the diagnosis and gradually restoring nervous system function with graded exercise learning how to manage symptoms of fatigue and pain when present and treatment of associated symptoms of worry or low mood if present hypnosis may also be useful
a functioning tumor is a tumor that is found in endocrine tissue and makes hormones chemicals that travel in the bloodstream and control the actions of other cells or organs
fundic gland polyposis is a medical syndrome where the fundus and the body of the stomach develop many polyps the condition has been described both in patients with familial adenomatous polyposis fap and attenuated variants afap and in patients in whom it occurs sporadically
fungal folliculitis also known as majocchi granuloma is a skin condition characterized by a deep pustular type of tinea circinata resembling a carbuncle or kerion
a fungal keratitis is an inflammation of the eye s cornea called keratitis that results from infection by a fungal organism keratomycosis is the greek terminology equivalent of fungal keratitis it is the fungal infection of the cornea the anterior part of the eye which covers the pupil those experiencing these symptoms are typically advised to immediately visit the appropriate eyecare professional
fungal meningitis refers to meningitis caused by a fungal infection one form of fungal meningitis is cryptococcal meningitis patients treated for cancer or chronic illnesses where treatments and or the disease itself compromise the patient s immune system are particularly vulnerable most common in aids patients cryptococcal fungal meningitis cases have increased globally during the past decade national health data estimates the incidence to be approximately 1 500 cases annually in the u s
fungal pneumonia is an infection of the lungs by fungi it can be caused by either endemic or opportunistic fungi or a combination of both case mortality in fungal pneumonias can be as high as 90 in immunocompromised patients though immunocompetent patients generally respond well to anti fungal therapy
fungal sinusitis is the inflammation of the lining mucosa of the paranasal sinuses it occurs in people with reduced immunity the maxillary sinus is the most commonly involved fungus responsible are aspergillus fumigatus 90 aspergillus flavus and aspergillus niger fungal sinusitis occurs most commonly in middle aged populations diabetes mellitus is the most common risk factor involved
a fungating lesion is a skin lesion that fungates that is becomes like a fungus in its appearance or growth rate it is marked by ulcerations breaks on the skin or surface of an organ and necrosis death of living tissue and that usually has a bad smell this kind of lesion may occur in many types of cancer including breast cancer melanoma and squamous cell carcinoma and especially in advanced disease the characteristic malodorous smell is caused by dimethyl trisulfide it is usually not literally a fungal infection but rather a neoplastic growth with necrosing portions
fungemia or fungaemia is the presence of fungi or yeasts in the blood the most common type also known as candidemia candedemia or systemic candidiasis is caused by candida species but infections by other fungi including saccharomyces aspergillus and cryptococcus are also called fungemia it is most commonly seen in immunosuppressed or immunocompromised patients with severe neutropenia cancer patients or in patients with intravenous catheters it has been suggested the otherwise immunocompetent patients taking infliximab may be at a higher risk for fungemia diagnosis is difficult as routine blood cultures have poor sensitivity
funisitis is inflammation of the connective tissue of the umbilical cord which may cause abortion it is typically preceded by vasculitis of the umbilical artery or veins and may be the result of chorioamnionitis
in dentistry a furcation defect is bone loss usually a result of periodontal disease affecting the base of the root trunk of a tooth where two or more roots meet bifurcation or trifurcation the extent and configuration of the defect are factors in both diagnosis and treatment planning a tooth with a furcation defect typically possessed a more diminished prognosis owing to the difficulty of rendering the furcation area free from periodontal pathogens for this reason surgical periodontal treatment may be considered to either close the furcation defect with grafting procedures or allow greater access to the furcation defect for improved oral hygiene
a furnace roller can be used in many applications for example in steel manufacturing one common problem is heat loss due to water cooling of roller i e cooling of furnace higher power needed new technology has open up an opportunity to save money and down time usage of material that can withstand high temperature oxidation
fusariosis is an infection seen in neutropenic patients and is a significant opportunistic pathogen in patients with hematologic malignancy it is associated with infections with fusarium species such as fusarium proliferatum
fusarium ear blight also called feb fusarium head blight fhb or scab is a fungal disease in plants it is responsible for the most common damaging disease that affects golf course grass
fusarium patch is a disease in turf grass settings called pink snow mold microdochium patch or fusarium patch microdochium nivale is the pathogen that causes this disease in many cool season turf grass species in north america the white pink mycelium on infected leaf blades is a distinguishing characteristic of the microdochium nivale pathogen fusarium patch is considered economically important in the turf grass industry because of its tendency to cause significant injury to golf greens thereby decreasing putting surface quality dissimilar from other snow molds such as gray snow mold microdochium nivale does not need snow cover to cause widespread infection
fusarium wilt is a common vascular wilt fungal disease exhibiting symptoms similar to verticillium wilt the pathogen that causes fusarium wilt is fusarium oxysporum f oxysporum the species is further divided into forma specialis based on host plant
fusebox funk is a powerhouse 6 piece funk hip hop phenomenon hailing from jacksonville fl fusebox funk has thrilled tens of thousands of fans at clubs and festivals across the country since their debut in 2001 featuring a full horn section 3 vocalists and one of the tightest rhythm sections in the region fusebox funk is guaranteed to be a standout at any venue or festival and can appeal to any type of audience the group features a plethora of talent including gold record artist j dash on keys and vocals
the fused grid is a street network pattern first proposed in 2002 and subsequently applied in calgary alberta 2006 and stratford ontario 2004 it represents a synthesis of two well known and extensively used network concepts the grid and the radburn pattern derivatives of which are found in most city suburbs both concepts were self conscious attempts to organize urban space for habitation the grid was conceived and applied in the pre automotive era of cities starting circa 2000 bc and prevailed until about 1900 ad the radburn pattern emerged in 1929 about thirty years following the invention of the internal combustion engine powered automobile and in anticipation of its eventual dominance as a means for mobility and transport both these patterns appear throughout north america fused refers to a systematic recombination of the essential characteristics of each of these two network patterns
the fåhræus effect is the decrease in average concentration of red blood cells in human blood as the diameter of the glass tube in which it is flowing decreases in other words in blood vessels with diameters less than 500 micrometers the hematocrit decreases with decreasing capillary diameter the fåhræus effect definitely influences the fåhræus – lindqvist effect which describes the dependence of apparent viscosity of blood on the capillary size but the former is not the only cause of the latter
gapo syndrome is a rare autosomal recessive disorder that causes severe growth retardation and has been observed fewer than 30 times before 2011 gapo is an acronym that encompasses the predominant traits of the disorder growth retardation alopecia pseudoanodontia teeth failing to emerge from the gums and worsening optic atrophy in some subjects other common symptoms include premature aging large prominent foreheads and delayed bone aging gapo syndrome typically results in premature death around age 30 40 due to interstitial fibrosis and atherosclerosis
in molecular biology a gc box is a distinct pattern of nucleotides found in the promoter region of some eukaryotic genes upstream of the tata box and approximately 110 bases upstream from the transcription initiation site it has a consensus sequence gggcgg which is position dependent and orientation independent the gc elements are bound by transcription factors and have similar functions to enhancers
the gm 1 gangliosidoses are caused by a deficiency of beta galactosidase with resulting abnormal storage of acidic lipid materials in cells of the central and peripheral nervous systems but particularly in the nerve cells
gm 2 gangliosidosis ab variant is a rare autosomal recessive metabolic disorder that causes progressive destruction of nerve cells in the brain and spinal cord it has a similar pathology to sandhoff disease and tay sachs disease the three diseases are classified together as the gm 2 gangliosidoses because each disease represents a distinct molecular point of failure in the activation of the same enzyme beta hexosaminidase ab variant is caused by a failure in the gene that makes an enzyme cofactor for beta hexosaminidase called the gm 2 activator
the gm 2 gangliosidoses are a group of three related genetic disorders that result from a deficiency of the enzyme beta hexosaminidase this enzyme catalyzes the biodegradation of fatty acid derivatives known as gangliosides the diseases are better known by their individual names beta hexosaminidase is a vital hydrolytic enzyme found in the lysosomes that breaks down lipids when beta hexosaminidase is no longer functioning properly the lipids accumulate in the nervous tissue of the brain and cause problems gangliosides are made and biodegraded rapidly in early life as the brain develops except in some rare late onset forms the gm 2 gangliosidoses are fatal all three disorders are rare in the general population tay sachs disease has become famous as a public health model because an enzyme assay test for tsd was discovered and developed in the late 1960 s and early 1970 s providing one of the first mass screening tools in medical genetics it became a research and public health model for understanding and preventing all autosomal genetic disorders tay sachs disease ab variant and sandhoff disease might easily have been defined together as a single disease because the three disorders are associated with failure of the same metabolic pathway and have the same outcome classification and naming for many genetic disorders reflects history because most diseases were first observed and classified based on biochemistry and pathophysiology before genetic diagnosis was available however the three gm 2 gangliosidoses were discovered and named separately each represents a distinct molecular point of failure in a subunit that is required for activation of the enzyme
gms syndrome is a syndrome characterised by goniodysgenesis intellectual disability and short stature
gracile syndrome is a very rare autosomal recessive genetic disorder one of the finnish heritage diseases it is caused by mutation in bcs 1 l gene that occurs in 1 out of 1 500 000 live births gracile is an acronym for growth retardation amino aciduria amino acids in the urine cholestasis iron overload lactic acidosis and early death other names for this syndrome include finnish lethal neonatal metabolic syndrome flnms lactic acidosis finnish with hepatic hemosiderosis and fellman syndrome
grik 4 glutamate receptor ionotropic kainate 4 is a kainate receptor subtype belonging to the family of ligand gated ion channels which is encoded by the grik 4 gene
the gabriel synthesis is a chemical reaction that transforms primary alkyl halides into primary amines traditionally the reaction uses potassium phthalimide the reaction is named after the german chemist siegmund gabriel the gabriel reaction has been generalized to include the alkylation of sulfonamides and imides followed by deprotection to obtain amines see alternative gabriel reagents the alkylation of ammonia is often an unselective and inefficient route to amines in the gabriel method phthalimide anion is employed as a surrogate of h 2 n −
the gabriel – colman rearrangement is the chemical reaction of a saccharin or phthalimido ester with a strong base such as an alkoxide to form substituted isoquinolines this rearrangement a ring expansion is seen to be general if there is an enolizable hydrogen on the group attached to the nitrogen since it is necessary for the nitrogen to abstract a hydrogen to form the carbanion that will close the ring as shown in the case of the general example below x is either co or so 2 gabriel colman rearrangement overall reaction
gaffkaemia gaffkemia in american english is a bacterial disease of lobsters caused by the gram positive lactic acid bacterium aerococcus viridans var homari
in financial accounting a gain is the increase in owner s equity resulting from something other than the day to day earnings from recurrent operations and are not associated with investments or withdrawals typical gains refer to nontypical and nonrecurring transactions for instance gain on sale of land change in a stock ’ s market price a gift or a chance discovery
gait is the pattern of movement of the limbs of animals including humans during locomotion over a solid substrate most animals use a variety of gaits selecting gait based on speed terrain the need to maneuver and energetic efficiency different animal species may use different gaits due to differences in anatomy that prevent use of certain gaits or simply due to evolved innate preferences as a result of habitat differences while various gaits are given specific names the complexity of biological systems and interacting with the environment make these distinctions fuzzy at best gaits are typically classified according to footfall patterns but recent studies often prefer definitions based on mechanics the term typically does not refer to limb based propulsion through fluid mediums such as water or air but rather to propulsion across a solid substrate by generating reactive forces against it which can apply to walking while underwater as well as on land due to the rapidity of animal movement simple direct observation is rarely sufficient to give any insight into the pattern of limb movement in spite of early attempts to classify gaits based on footprints or the sound of footfalls it wasn t until eadweard muybridge and étienne jules marey began taking rapid series of photographs that proper scientific examination of gaits could begin
a galactocele also lacteal cyst or milk cyst is a retention cyst containing milk or a milky substance that is usually located in the mammary glands it is caused by a protein plug that blocks off the outlet it is seen in lactating women on cessation of lactation once lactation has ended the cyst should resolve on its own without intervention a galactocele does not cause infection as the milk within is sterile and has no outlet for which to become contaminated attempts to drain the cyst are unsuccessful because the protein plug remains intact and milk production continues it presents as a large soft fluctuating lump in the lower part of breast it is not usually painful treatment is by aspiration of the contents or by excision of the cyst antibiotics are given to prevent infection galactocele may be associated with oral contraceptive use
galactokinase deficiency also known as galactosemia type 2 or galk deficiency is an autosomal recessive metabolic disorder marked by an accumulation of galactose and galactitol secondary to the decreased conversion of galactose to galactose 1 phosphate by galactokinase the disorder is caused by mutations in the galk 1 gene located on chromosome 17 q 24 galactokinase catalyzes the first step of galactose phosphorylation in the leloir pathway of intermediate metabolism galactokinase deficiency is one of the three inborn errors of metabolism that lead to hypergalactosemia the disorder is inherited as an autosomal recessive trait unlike classic galactosemia which is caused by deficiency of galactose 1 phosphate uridyltransferase galactokinase deficiency does not present with severe manifestations in early infancy its major clinical symptom is the development of cataracts during the first weeks or months of life as a result of the accumulation in the lens of galactitol a product of an alternative route of galactose utilization the development of early cataracts in homozygous affected infants is fully preventable through early diagnosis and treatment with a galactose restricted diet some studies have suggested that depending on milk consumption later in life heterozygous carriers of galactokinase deficiency may be prone to presenile cataracts at 20 – 50 years of age
galactorrhea also spelled galactorrhoea galacto rrhea or lactorrhea lacto rrhea is the spontaneous flow of milk from the breast unassociated with childbirth or nursing galactorrhea is reported to occur in 5 – 32 of women much of the difference in reported incidence can be attributed to different definitions of galactorrhea although frequently benign it may be caused by serious underlying conditions and should be properly investigated galactorrhea also occurs in males newborn infants and adolescents of both sexes
galactose 1 phosphate uridylyltransferase deficiency also called galactosemia type 1 classic galactosemia or galt deficiency is the most common type of galactosemia an inborn error of galactose metabolism caused by a deficiency of the enzyme galactose 1 phosphate uridylyltransferase it is an autosomal recessive metabolic disorder that can cause liver disease and death if untreated treatment of galactosemia is most successful if initiated early and includes dietary restriction of lactose intake because early intervention is key galactosemia is included in newborn screening programs in many areas on initial screening which often involves measuring the concentration of galactose in blood classic galactosemia may be indistinguishable from other inborn errors of galactose metabolism including galactokinase deficiency and galactose epimerase deficiency further analysis of metabolites and enzyme activities are needed to identify the specific metabolic error
galactose epimerase deficiency also known as gale deficiency galactosemia iii and udp galactose 4 epimerase deficiency is a rare autosomal recessive form of galactosemia associated with a deficiency of the enzyme galactose epimerase
galactosemia british galactosaemia is a rare genetic metabolic disorder that affects an individual s ability to metabolize the sugar galactose properly galactosemia follows an autosomal recessive mode of inheritance that confers a deficiency in an enzyme responsible for adequate galactose degradation friedrich goppert 1870 – 1927 a german physician first described the disease in 1917 with its cause as a defect in galactose metabolism being identified by a group led by herman kalckar in 1956 its incidence is about 1 per 60 000 births for people of european ancestry in other populations the incidence rate differs galactosaemia is about one hundred times more common 1 480 births within the irish traveller population
a galactosemic cataract is cataract which is associated with the consequences of galactosemia
galactosialidosis is a lysosomal storage disease this condition is rare and most cases have been in the juvenile adult group of patients an infantile form has been described
the galeazzi fracture is a fracture of the radius with dislocation of the distal radioulnar joint it classically involves an isolated fracture of the junction of the distal third and middle third of the radius with associated subluxation or dislocation of the distal radio ulnar joint the injury disrupts the forearm axis joint
galen partners is a leading growth equity late stage venture capital firm that invests in high growth healthcare firms already generating revenue and focuses on healthcare technology enabled services medical devices and specialty pharmaceutical companies founded in 1990 by the late william r grant galen has raised nearly 1 billion through five funds and has invested in more than 70 companies since inception in 2006 the company relocated its headquarters from new york city ’ s rockefeller center to stamford connecticut
the culture of galicia is the patterns of human activity and symbolism associated with the galicia region of spain and the galician people
gallbladder cancer is a relatively uncommon cancer it has peculiar geographical distribution being common in central and south america central and eastern europe japan and northern india it is also common in certain ethnic groups e g native american indians and hispanics if it is diagnosed early enough it can be cured by removing the gallbladder part of the liver and associated lymph nodes most often it is found after symptoms such as abdominal pain jaundice and vomiting occur and it has spread to other organs such as the liver it is a rare cancer that is thought to be related to gallstones building up which also can lead to calcification of the gallbladder a condition known as porcelain gallbladder porcelain gallbladder is also rare some studies indicate that people with porcelain gallbladder have a high risk of developing gallbladder cancer but other studies question this the outlook is poor for recovery if the cancer is found after symptoms have started to occur with a 5 year survival rate close to 3
gallbladder diseases are diseases involving the gallbladder gallstones may develop in the gallbladder as well as elsewhere in the biliary tract if gallstones in the gallbladder are symptomatic surgical removal of the gallbladder known as cholecystectomy may be indicated gallstones form when the tenuous balance of solubility of biliary lipids tips in favor of precipitation of cholesterol unconjugated bilirubin or bacterial degradation products of biliary lipids for cholesterol gallstones metabolic alterations in hepatic cholesterol secretion combine with changes in gallbladder motility and intestinal bacterial degradation of bile salts to destabilize cholesterol carriers in bile and produce cholesterol crystals for black pigment gallstones changes in heme metabolism or bilirubin absorption lead to increased bilirubin concentrations and precipitation of calcium bilirubinate in contrast mechanical obstruction of the biliary tract is the major factor leading to bacterial degradation and precipitation of biliary lipids in brown pigment stones about 104 million new cases of gallbladder and biliary disease occurred in 2013
gallbladder polyps are growths or lesions resembling growths polypoid lesions in the wall of the gallbladder true polyps are abnormal accumulations of mucous membrane tissue that would normally be shed by the body the main types of polypoid growths of the gallbladder include cholesterol polyp cholesterosis cholesterosis with fibrous dysplasia of gallbladder adenomyomatosis hyperplastic cholecystosis and adenocarcinoma
galli – galli disease is a rare inherited condition that has close resemblance clinically to dowling degos disease but is histologically distinct characterized by skin lesions that are 1 to 2 mm slightly keratotic red to dark brown papules which are focally confluent in a reticulate pattern the disease is also characterized by slowly progressive and disfiguring reticulate hyperpigmentation of the flexures clinically and histopathologically diagnostic for dowling degos disease but also associated with suprabasal nondyskeratotic acantholysis
a gallop rhythm refers to a usually abnormal rhythm of the heart on auscultation it includes three or four sounds thus resembling the sounds of a gallop the normal heart rhythm contains two audible heart sounds called s 1 and s 2 that give the well known lub dub rhythm they are caused by the closing of valves in the heart a gallop rhythm contains another sound called s 3 or s 4 dependent upon where in the cycle this added sound comes it can also contain both of these sounds forming a quadruple gallop and in situations of very fast heart rate can produce a summation gallop where s 3 and s 4 occur so close as to be indistinguishable
galloway mowat syndrome is a very rare autosomal recessive genetic disorder consisting of a variety of features including hiatal hernia microcephaly and nephrotic syndrome
a gallstone is a stone formed within the gallbladder out of bile components the term cholelithiasis may refer to the presence of stones in the gallbladder or to the diseases caused by gallstones most people with gallstones about 80 never have symptoms in 1 – 4 of those with gallstones a crampy pain in the right upper part of the abdomen known as biliary colic occurs each year complications of gallstones include inflammation of the gallbladder inflammation of the pancreas and liver inflammation symptoms of these complications may include pain of more than five hours duration fever yellowish skin vomiting or tea color urine risk factors for gallstones include birth control pills pregnancy a family history of gallstones obesity diabetes liver disease or rapid weight loss gallstones are formed in the gallbladder typically from either cholesterol or bilirubin gallstones may be suspected based on symptoms diagnosis is then typically confirmed by ultrasound complications may be detected on blood tests prevention is by maintaining a healthy weight and eating a proper diet if there are no symptoms treatment is usually not needed in those who are having gallbladder attacks surgery to remove the gallbladder is typically recommended this can be either done through several small incisions or through a single larger incision surgery is typically done under general anesthesia in those who are unable to have surgery medication to try to dissolve the stones or shock wave lithotripsy may be tried in the developed world 10 – 15 of adults have gallstones rates in many parts of africa however are as low as 3 gallbladder and biliary related diseases occurred in about 104 million people 1 6 in 2013 and they resulted in 106 000 deaths women more commonly have stones than men and they occur more commonly after the age of 40 certain ethnic groups have gallstones more often than others for example 48 of american indians have gallstones once the gallbladder is removed outcomes are generally good
the proposed galore creek mine is one of the largest undeveloped gold deposits in canada and in the world the deposit is located in the north west of the country in british columbia the mine has estimated reserves of 10 7 million oz of gold and 183 1 million oz of silver
galton s problem named after sir francis galton is the problem of drawing inferences from cross cultural data due to the statistical phenomenon now called autocorrelation the problem is now recognized as a general one that applies to all nonexperimental studies and to experimental design as well it is most simply described as the problem of external dependencies in making statistical estimates when the elements sampled are not statistically independent asking two people in the same household whether they watch tv for example does not give you statistically independent answers the sample size n for independent observations in this case is one not two once proper adjustments are made that deal with external dependencies then the axioms of probability theory concerning statistical independence will apply these axioms are important for deriving measures of variance for example or tests of statistical significance
galvani potential also called galvani potential difference or inner potential difference δφ delta phi in electrochemistry is the electric potential difference between two points in the bulk of two phases these phases can be two different solids e g two metals joined together or a solid and a liquid e g a metal electrode submerged in an electrolyte generally the galvani potential difference is measurable only when the two phases have identical chemical composition the galvani potential is named after luigi galvani
galvanic urticaria has been described after exposure to a galvanic electrical device used to treat hyperhidrosis
gamasoidosis is a cutaneous condition that occurs after contact with canaries pigeons and poultry caused by two genera of mites including ornithonyssus and dermanyssus
in the dungeons dragons fantasy role playing game the gambado is a type of aberration
gamekeeper s thumb also known as skier s thumb or ucl tear is a type of injury to the ulnar collateral ligament ucl of the thumb the ucl is torn at or in some cases even avulsed from its insertion site into the proximal phalanx of the thumb in the vast majority approximately 90 of cases this condition is commonly observed among gamekeepers and scottish fowl hunters as well as athletes such as volleyballers it also occurs among people who sustain a fall onto an outstretched hand
a gamma wave is a pattern of neural oscillation in humans with a frequency between 25 and 100 hz though 40 hz is typical according to a popular theory gamma waves may be implicated in creating the unity of conscious perception the binding problem however there is no agreement on the theory as a researcher suggests whether or not gamma wave activity is related to subjective awareness is a very difficult question which cannot be answered with certainty at the present time
a gamow bag pronounced gam off is an inflatable pressure bag large enough to accommodate a person inside a patient can be placed inside the bag which is sealed and inflated with a foot pump within minutes the effective altitude can be decreased by 1000 to as much as 3000 meters 3281 to 9743 feet depending on the elevation the bag is pressurized to 105 220 mm pressure gradient is regulated by pop off valves set to the target pressure it is primarily used for treating severe cases of altitude sickness high altitude cerebral edema and high altitude pulmonary edema like office based hyperbaric medicine the gamow bag uses increased partial pressure of oxygen for therapy of hypobaric injury but it has the advantage of being portable for field use patients typically are treated in 1 hour increments and then are reevaluated the gamow bag was named after its inventor dr igor gamow son of george gamow dr gamow originally designed a predecessor to the gamow bag called the bubble to study the effect of high altitude on stamina and performance in athletes dr gamow later re designed the bubble into a bag that could be used in the high altitude wilderness
gang presence in the united states military is a phenomenon in which members of american street gangs such as the crips latin kings aryan brotherhood and many others either join the united states armed forces or are recruited to join the gangs while already in the military
a gangliocytic paraganglioma abbreviated gp is a rare tumour that is typically found in the duodenum and consists of three components 1 ganglion cells 2 epithelioid cells paraganglioma like and 3 spindle cells schwannoma like
ganglioglioma is a rare slow growing primary central nervous system cns tumor which most frequently occurs in the temporal lobes of children and young adults
a ganglion cyst is a soft tissue lump that may occur in any joint but most often occurs on around or near joints and tendons in the hands or feet these cysts are caused by leakage of fluid from the joint into the surrounding tissue
ganglioneuroblastoma is a variant of neuroblastoma that is surrounded by ganglion cells it can be difficult to diagnose nodular ganglioneuroblastoma can be divided by prognosis
ganglioneuroma is a rare and benign tumor of the autonomic nerve fibers arising from neural crest sympathogonia which are completely undifferentiated cells of the sympathetic nervous system however ganglioneuromas themselves are fully differentiated neuronal tumors that do not contain immature elements ganglioneuromas most frequently occur in the abdomen however these tumors can grow anywhere sympathetic nervous tissue is found other common locations include the adrenal gland paraspinal retroperitoneum posterior mediastinum head and neck
gangliosidosis is a sub category of sphingolipidosis that contains two different types of lipid storage disorders caused by the accumulation of lipids known as gangliosides there are two distinct genetic causes of the disease both are autosomal recessive and affect males and females equally
gangrene or gangrenous necrosis is a type of necrosis caused by a critically insufficient blood supply this potentially life threatening condition may occur after an injury or infection or in people suffering from any chronic health problem affecting blood circulation the primary cause of gangrene is reduced blood supply to the affected tissues which results in cell death diabetes and long term smoking increase the risk of suffering from gangrene gangrene is not a communicable disease it does not spread from person to person the types of gangrene differ in symptoms and include dry gangrene wet gangrene gas gangrene internal gangrene and necrotizing fasciitis treatment depends on the underlying cause and can include resection debridement or in severe cases amputation of the affected body parts antibiotics revascularization via a vascular bypass or angioplasty or hyperbaric oxygen therapy it can rarely include medical therapy to stop vascular spasm or the production of cold induced vascular obstruction by cold precipitated cryoglobulins
ganguru is an out growth to vijayawada in krishna district of the indian state of andhra pradesh it forms a part of vijayawada urban agglomeration and is located in penamaluru mandal of vijayawada revenue division
ganser syndrome is a rare dissociative disorder previously classified as a factitious disorder it is characterized by nonsensical or wrong answers to questions or doing things incorrectly other dissociative symptoms such as fugue amnesia or conversion disorder often with visual pseudohallucinations and a decreased state of consciousness it is also sometimes called nonsense syndrome balderdash syndrome syndrome of approximate answers pseudodementia hysterical pseudodementia or prison psychosis this last name prison psychosis is sometimes used because the syndrome occurs most frequently in prison inmates where it may represent an attempt to gain leniency from prison or court officials ganser is an extremely rare variation of dissociative disorder it is a reaction to extreme stress and the patient thereby suffers from approximation or giving absurd answers to simple questions the syndrome can sometimes be diagnosed as merely malingering but it is more often defined as dissociative disorder symptoms include a clouding of consciousness somatic conversion symptoms confusion stress loss of personal identity echolalia and echopraxia the psychological symptoms generally resemble the patient s sense of mental illness rather than any recognized category individuals also give approximate answers to simple questions for example how many legs are on a cat to which the subject may respond three the syndrome may occur in persons with other mental disorders such as schizophrenia depressive disorders toxic states paresis alcohol use disorders and factitious disorders eeg data does not suggest any specific organic cause
the ganzfeld effect from german for “ complete field ” or perceptual deprivation is a phenomenon of perception caused by exposure to an unstructured uniform stimulation field the effect is the result of the brain amplifying neural noise in order to look for the missing visual signals the noise is interpreted in the higher visual cortex and gives rise to hallucinations it has been most studied with vision by staring at an undifferentiated and uniform field of colour the visual effect is described as the loss of vision as the brain cuts off the unchanging signal from the eyes the result is seeing black an apparent sense of blindness a flickering ganzfeld causes geometrical patterns and colors to appear and this is the working principle for mind machines and the dreamachine the ganzfeld effect can also elicit hallucinatory percepts in many people in addition to an altered state of consciousness ganzfeld induction in multiple senses is called multi modal ganzfeld this is usually done by wearing ganzfeld goggles in addition to headphones with a uniform stimulus a related effect is sensory deprivation although in this case a stimulus is minimized rather than unstructured hallucinations that appear under prolonged sensory deprivation are similar to elementary percepts caused by luminous ganzfeld and include transient sensations of light flashes or colours hallucinations caused by sensory deprivation can like ganzfeld induced hallucinations turn into complex scenes the effect is a component of a ganzfeld experiment a technique used in the field of parapsychology
in the dungeons dragons fantasy role playing game the garbug is a type of aberration
the garden house riot was a civil disturbance at the garden house hotel in cambridge on friday 13 february 1970 it was the only serious disturbance in cambridge in the period around the widespread 1968 student protests the event has been described as a marking a watershed in student protest in the uk
gardner syndrome also known as gardner s syndrome or familial colorectal polyposis is an autosomal dominant form of polyposis characterized by the presence of multiple polyps in the colon together with tumors outside the colon the extracolonic tumors may include osteomas of the skull thyroid cancer epidermoid cysts fibromas as well as the occurrence of desmoid tumors in approximately 15 of affected individuals desmoid tumors are fibrous tumors which usually occur in the tissue covering the intestines and may be provoked by surgery to remove the colon the countless polyps in the colon predispose to the development of colon cancer if the colon is not removed the chance of colon cancer is considered to be very significant polyps may also grow in the stomach duodenum spleen kidneys liver mesentery and small bowel in a small number of cases polyps have also appeared in the cerebellum cancers related to gardner syndrome commonly appear in the thyroid liver and kidneys the number of polyps increases with age and hundreds to thousands of polyps can develop in the colon the syndrome was first described in 1951 there is no cure at this time and in its more advanced forms it is considered a terminal diagnosis with a life expectancy of 35 – 45 years treatments are surgery and palliative care although some chemotherapy has been tried with limited success
garlic allergy or allergic contact dermatitis to garlic is a common inflammatory skin condition caused by contact with garlic oil or dust it mostly affects people who cut and handle fresh garlic such as chefs and presents on the tips of the thumb index and middle fingers of the non dominant hand which typically hold garlic bulbs during the cutting the affected fingertips show an asymmetrical pattern of fissure as well as thickening and shedding of the outer skin layers which may progress to second or third degree burn of injured skin garlic dermatitis is similar to the tulip dermatitis and is induced by a combined mechanical and chemical action whereas the former mechanism acts via skin rubbing which progresses into damage the major cause of the latter is the chemical diallyl disulfide dads together with related compounds allyl propyl disulfide and allicin these chemicals occur in oils of plants of the genus allium including garlic onion and leek garlic allergy has been known since at least 1950 it is not limited to hand contact but can also be induced with different symptoms by inhaling garlic dust or ingesting raw garlic though the latter cases are relatively rare dads penetrates through most types of commercial gloves and thus wearing gloves while handling garlic has proven inefficient against the allergy treatment includes avoiding any contact with garlic oil or vapors as well as medication such as administering acitretin 25 mg day orally or applying psoralen and ultraviolet light to the affected skin area over a period of 12 weeks puva therapy
garre s sclerosing osteomyelitis is a type of chronic osteomyelitis also called proliferative periostitis periostitis ossificans and garré s sclerosing osteomyelitis it is a rare disease it mainly affects children and young adults it is associated with a low grade infection which may be due to dental caries cavities in the teeth the body of the mandible may show irregular lucent opaque changes with subperiosteal opaque layering along inferior border it is a chronic osteomyelitis with subperiosteal bone and collagen deposition it was first described by the swiss surgeon carl garré
garrod s pads also known as violinist s pads are a cutaneous condition characterized by calluses on the dorsal aspect of the interphalangeal joints i e the back side of the finger joints they are often seen in violin viola and cello players along with fiddler s neck and other dermatologic conditions peculiar to string musicians although garrod ’ s pads are conventionally described as appearing on the proximal interphalangeal joint rimmer spielvogel document an instance on the distal interphalangeal joint of a cellist garrod s pads are named after archibald garrod who first documented them in 1904 in association with dupuytren s contracture h a bird described them as an incidental finding in a professional violinist and proposed that they arise in such cases due to repeated extreme tension of the extensor tendons over the interphalangeal joints bird noted that violin players use the left hand for a markedly different task than the right hand with the extensor tendons in the left hand subjected to considerable tension and that garrod ’ s pads only arise on the left hand in such cases this unilateral finding differentiates the occupational hazard of garrod ’ s pads from more significant disorders among violinists and violists garrod ’ s pads apparently arise as a protective mechanism for the skin and subcutaneous tissues above the tendons bird notes that they do not protect against external trauma unlike most calluses patients with dupuytren s contracture are four times more likely to have coexisting garrod s pads
in medicine garrod s tetrad is a term named for british physician archibald garrod who introduced the phrase inborn errors of metabolism in a lecture in 1908 the tetrad comprises four inherited metabolic diseases albinism alkaptonuria cystinuria and pentosuria
the garshelis effect is the effect wherein a circumferentially magnetized rod of ferromagnetic magnetostrictive material generates a net axial magnetic field in response to an applied torque
a gartner s duct cyst sometimes incorrectly referred to as vaginal inclusion cyst is a benign vaginal cystic lesion that arises from the vestigial remnant of a mesonephric duct wolffian duct or gartner s duct they are typically small asymptomatic cysts that occur along the lateral walls of the vagina following the course of the duct they can however enlarge to substantial proportions and be mistaken for urethral diverticulum or other structures there is a small association between gartner s duct cysts and metanephric urinary anomalies such as ectopic ureter ipsilateral renal hypoplasia
gas stokers strike of 1873 was a serious political disturbance in the industrial south eastern districts of victorian london involving trade unionists striking to assert their rights the reaction of the radical liberal ministry and the court case that preceded it proved a landmark in british industrial relations law the shifting sands of the constitution and changing rights of workers informed the passage a decade later of third reform act enfranchising working men for the first time even the most enlightened manchester liberal capitalists were hostile to trade unionists during the downturn of the early 1870 s cabinet ministers william harcourt forster hughes and a j mundella were major participants in legislation to reform trade unionism laws in 1873 in 1872 henry james the employment minister drafted a new piece of trade union law
gas depletion is the decline in natural gas production of a well gas field or geographic area
a gas evolution reaction is a chemical reaction in which one of the end products is a gas such as oxygen or carbon dioxide is produced see also oxygen evolution acid base reactions are a specific type of gas evolution reaction there are also gas evolution reactions that are formed by the mixing of two aqueous solutions these reactions are a sub type of double replacement or double displacement reactions most of gas evolution reactions are done in a fume chamber because some of the gases are very poisonous when inhaled while other gases are explosive
gas gangrene also known as clostridial myonecrosis and myonecrosis is a bacterial infection that produces gas in tissues in gangrene this deadly form of gangrene usually is caused by clostridium perfringens bacteria it is a medical emergency about 1000 cases of gas gangrene occur yearly in the united states myonecrosis is a condition of necrotic damage specific to muscle tissue it is often seen in infections with c perfringens or any of myriad soil borne anaerobic bacteria bacteria cause myonecrosis by specific exotoxins these microorganisms are opportunistic and in general enter the body through significant skin breakage gangrenous infection by soil borne bacteria was common in the combat injuries of soldiers well into the 20 th century because of nonsterile field surgery and the basic nature of care for severe projectile wounds other causes of myonecrosis include envenomation by snakes of the bothrops genus family viperidae ischemic necrosis caused by vascular blockage e g diabetes type ii tumours that block or hoard blood supply and disseminated intravascular coagulation or other thromboses
gas volume corrector device for calculating summing and determining increments of gas volume measured by gas meter if it were operating base conditions for this purpose uses as input the gas volume measured by the gas meter and other parameters such as gas pressure and temperature it is used for the settlement of trade wholesale gas there are two types of gas volume correctors type 1 gas volume corrector with specific types of transducers for pressure and temperature or temperature only this type of gas volume corrector is powered by battery type 2 a device that converts separate transmitters with external temperature and pressure or temperature only and for separate calculator which may be approved separately this type of gas volume corrector is powered by mains
in sailing gaskets are lengths of rope or fabric used to hold a stowed sail in place in modern use the term is usually restricted to square rigged ships the equivalent items on yachts being referred to by the more prosaic sail ties on most ships gaskets are made of rope they are attached to the top of the yard and left loose would hang behind the sail gaskets should never be left dangling however so when the sail is set they are brought around underneath the yard and up the back of it and then tied to the jackstay metal rod where they originated alternatively longer gaskets particularly the clew gaskets described below can be secured using a gasket coil when the sail is to be stowed it is first folded and bagged neatly within itself pulled onto the top of the yard and then the gaskets are brought round over it and secured to the jackstay to hold it in place gaskets should be tied with a slippery hitch to enable them to be let off quickly though if the yard is large there may only be enough rope to form a clove hitch when the gasket is brought round it most ships are equipped with clew gaskets at the outer ends of the yards these do not pass around the sail but through a shackle or ring on the blocks of the sheet pulled tight and secured to the jackstay or the yard s lift this takes the load off the clewline and sail and should allow the blocks to be lifted higher dragging the sail down less and enabling a neater stow
gasoline gallon equivalent gge or gasoline equivalent gallon geg is the amount of alternative fuel it takes to equal the energy content of one liquid gallon of gasoline gge allows consumers to compare the energy content of competing fuels against a commonly known fuel — gasoline gge also compares gasoline to fuels sold as a gas natural gas propane hydrogen and electricity in 1994 the us national institute of standards and technology nist defined gasoline gallon equivalent gge means 5 660 pounds of natural gas compressed natural gas cng for example is a gas rather than a liquid it can be measured by its volume in standard cubic feet ft ³ volume at atmospheric conditions by its weight in pounds lb or by its energy content in joules j or british thermal units btu or kilowatt hours kw · h it is difficult to compare the cost of gasoline with other fuels if they are sold in different units gge solves this one gge of cng and one gge of electricity have exactly the same energy content as one gallon of gasoline cng sold at filling stations is priced in dollars per gge using gge to compare fuels for use in an internal combustion engine is only the first part of the equation whose bottom line is useful work in the context of gge a real world kind of useful work is miles per gallon mpg as advertised by motor vehicle manufacturers substituting one fuel for another in a given engine may start and may do useful work however getting optimum efficiency from each fuel – engine combination requires adjusting the mix of air and fuel this can be a manual adjustment using tools and test instruments or done automatically in computer controlled fuel injected and multi fuel vehicles fine tuning of the optimum fuel – air mix may be facilitated by using a supercharger or turbocharger in battery or electric vehicles calculating efficiency of useful work begins with the charge – discharge rate of the battery pack generally 80 to 90 next is the conversion of potential energy btu of the charge to distance traveled under power see table below translating retail electricity costs for a gge in btu note that throughout this article gallon refers to the us gallon of approximately 3 8 litres as opposed to the imperial gallon of approximately 4 5 litres
gastric antral vascular ectasia gave is an uncommon cause of chronic gastrointestinal bleeding or iron deficiency anemia the condition is associated with dilated small blood vessels in the antrum or the last part of the stomach the dilated vessels result in intestinal bleeding it is also called watermelon stomach because streaky long red areas that are present in the stomach may resemble the markings on watermelon the condition was first discovered in 1952 and reported in the literature in 1953 watermelon disease was first diagnosed by wheeler et al in 1979 and definitively described in four living patients by jabbari et al only in 1984 as of 2011 the cause and pathogenesis are still not known however there are several competing hypotheses as to various causes
gastric dilatation volvulus also known as twisted stomach gastric torsion and gdv is a medical condition in which the stomach becomes overstretched and rotated by excessive gas content the word bloat is often used as a general term to cover gas distension without twisting and is often a normal change after eating or with aerophagia it is sometimes used incorrectly to indicate gastric torsion gastric dilatation volvulus always involves the twisting of the stomach and is a life threatening condition that requires prompt treatment the condition occurs commonly in domesticated animals especially certain dog breeds deep chested breeds are especially at risk mortality rates in dogs range from 10 to 60 percent even with treatment with surgery the mortality rate is 15 to 33 percent
gastric dumping syndrome or rapid gastric emptying is a condition where ingested foods pass through the stomach very rapidly and enter the small intestine largely undigested it happens when the small intestine expands too quickly due to the presence of hyperosmolar having increased osmolarity contents from the stomach this causes symptoms due to the fluid shift into the gut lumen with plasma volume contraction and acute intestinal distention early dumping begins concurrently within 15 to 30 minutes from ingestion of a meal symptoms of early dumping include nausea vomiting bloating cramping diarrhea dizziness and fatigue late dumping happens one to three hours after eating symptoms of late dumping include weakness sweating and dizziness many people have both types the syndrome is most often associated with gastric bypass roux en y surgery rapid loading of the small intestine with hypertonic stomach contents can lead to rapid entry of water into the intestinal lumen osmotic diarrhea distension of the small bowel leading to crampy abdominal pain and hypovolemia can result in addition people with this syndrome often suffer from low blood sugar or hypoglycemia because the rapid dumping of food triggers the pancreas to release excessive amounts of insulin into the bloodstream this type of hypoglycemia is referred to as alimentary hypoglycemia
primary gastric lymphoma lymphoma that originates in the stomach itself is an uncommon condition accounting for less than 15 of gastric malignancies and about 2 of all lymphomas however the stomach is a very common extranodal site for lymphomas lymphomas originating somewhere else with metastasis to stomach it is also the most common source of lymphomas in the gastrointestinal tract
gastric mucosal restitution is an alteration in the morphology organization of cells in response to gastric damage it contributes to the reformation of the gastric mucosal barrier
gastric outlet obstruction often abbreviated as goo is a medical condition where there is an obstruction at the level of the pylorus which is the outlet of the stomach individuals with gastric outlet obstruction will often have recurrent vomiting of food that has accumulated in the stomach but which cannot pass into the small intestine due to the obstruction the stomach often dilates to accommodate food intake and secretions causes of gastric outlet obstruction include both benign causes such as peptic ulcer disease affecting the area around the pylorus as well as malignant causes such as gastric cancer causation related to ulcers may involve severe pain which the patient may interpret as a heart condition attack treatment of the condition depends upon the underlying cause it can involve antibiotic treatment when h pylori is related to an ulcer endoscopic therapies such as dilation of the obstruction with balloons or the placement of self expandable metallic stents other medical therapies or surgery to resolve the obstruction
gastric varices are dilated submucosal veins in the stomach which can be a life threatening cause of bleeding in the upper gastrointestinal tract they are most commonly found in patients with portal hypertension or elevated pressure in the portal vein system which may be a complication of cirrhosis gastric varices may also be found in patients with thrombosis of the splenic vein into which the short gastric veins which drain the fundus of the stomach flow the latter may be a complication of acute pancreatitis pancreatic cancer or other abdominal tumours as well as hepatitis c gastric varices and associated bleeding are a potential complication of schistosomiasis resulting from portal hypertension patients with bleeding gastric varices can present with bloody vomiting hematemesis dark tarry stools melena or rectal bleeding the bleeding may be brisk and patients may soon develop shock treatment of gastric varices can include injection of the varices with cyanoacrylate glue or a radiological procedure to decrease the pressure in the portal vein termed transjugular intrahepatic portosystemic shunt or tips treatment with intravenous octreotide is also useful to shunt blood flow away from the stomach s circulation more aggressive treatment including splenectomy or surgical removal of the spleen or liver transplantation may be required in some cases
gastric volvulus or volvulus of stomach is a twisting of all or part of the stomach by more than 180 degrees with obstruction of the flow of material through the stomach variable loss of blood supply and possible tissue death the twisting can occur around the long axis of the stomach this is called organoaxial or around the axis perpendicular to this called mesenteroaxial obstruction is more likely in organoaxial twisting than with mesenteroaxial while the latter is more associated with ischemia about one third of the cases are associated with a hiatus hernia treatment is surgical the classic triad borchardt s triad of gastric volvulus described by borchardt in 1904 consists of severe epigastric pain retching without vomiting inability to pass a nasogastric tube and reportedly occurs in 70 of cases sometimes severe pain at the top of left shoulder this may be due to internal bleeding irritating the diaphragm upon respiration
a gastrinoma is a tumor in the pancreas or duodenum that secretes excess of gastrin leading to ulceration in the duodenum stomach and the small intestine there is hypersecretion of the hcl acid into the duodenum which causes the ulcers excessive hcl acid production also causes hyperperistalsis and inhibits the activity of lipase causing severe diarrhea it is frequently the source of the gastrin in zollinger ellison syndrome it is usually found in the duodenum although it may arise in the stomach or pancreas those occurring in the pancreas have a greater potential for malignancy most gastrinomas are found in the gastrinoma triangle this is bound by the junction of cystic and common bile ducts junction of the second and third parts of the duodenum and the junction of the neck and body of the pancreas
gastritis is inflammation of the lining of the stomach it may occur as a short episode or may be of a long duration the most common symptom is upper abdominal pain other symptoms include nausea and vomiting bloating loss of appetite and heartburn others may have no symptoms complications may include bleeding stomach ulcers and stomach tumors when due to autoimmune problems low red blood cells due to not enough vitamin b 12 may occur a condition known as pernicious anemia common causes include infection with helicobacter pylori and use of nsaids less common causes include alcohol smoking cocaine severe illness autoimmune problems radiation therapy and crohn disease among others endoscopy a type of x ray known as an upper gastrointestinal series blood tests and stool tests may help with diagnosis the symptoms of gastritis may be a presentation of a myocardial infarction other conditions with similar symptoms include inflammation of the pancreas gallbladder problems and peptic ulcer disease prevention is by avoiding things that cause the disease treatment includes medications such as antacids h 2 blockers or proton pump inhibitors during an acute attack drinking viscous lidocaine may help if gastritis is due to nsaids these may be stopped if h pylori is present it may be treated with a combination of antibiotics such as amoxicillin and clarithromycin for those with pernicious anemia vitamin b 12 supplements are recommended either by mouth or by injection people are usually advised to avoid foods that bother them gastritis is believed to affect about half of people in 2013 there were approximately 90 million new cases of the disease as people get older the disease becomes more common it along with a similar condition in the first part of the intestines known as duodenitis resulted in 60 000 deaths in 2013 h pylori was first discovered in 1981 by barry marshall and robin warren
gastrocutaneous syndrome is a rare autosomal dominant cutaneous condition characterized by multiple lentigines
gastroenteritis also known as infectious diarrhea is inflammation of the gastrointestinal tract that involves the stomach and small intestine signs and symptoms include some combination of diarrhea vomiting and abdominal pain fever lack of energy and dehydration may also occur this typically lasts less than two weeks it is unrelated to influenza though it has been called the stomach flu gastroenteritis can be due to infections by viruses bacteria parasites and fungus the most common cause is viruses in children rotavirus is the most common cause of severe disease in adults norovirus and campylobacter are common transmission may occur due to eating improperly prepared foods drinking contaminated water or through close contact with an individual who is infected testing to confirm the diagnosis is typically not needed prevention includes hand washing with soap drinking clean water proper disposal of human waste and breastfeeding babies instead of using formula the rotavirus vaccine is recommended in children treatment involves getting enough fluids for mild or moderate cases this can typically be achieved by drinking oral rehydration solution a combination of water salts and sugar in those who are breast fed continued breastfeeding is recommended for more severe cases intravenous fluids may be needed fluids may also be given by a nasogastric tube zinc supplementation is recommended in children antibiotics are generally not needed it is estimated that three to five billion cases of gastroenteritis resulting in 1 4 million deaths occur globally each year children and those in the developing world are most commonly affected as of 2011 in those below age five there were about 1 7 billion cases resulting in 0 7 million deaths in the developing world children less than two years of age frequently get six or more infections a year it is less common in adults partly due to the development of immunity
gastroenterocolitis is a condition characterized by inflammation of the stomach small intestines and colon
gastroesophageal reflux disease gerd also known as acid reflux is a long term condition where stomach contents come back up into the esophagus resulting in either symptoms or complications symptoms include the taste of acid in the back of the mouth heartburn bad breath chest pain vomiting breathing problems and wearing away of the teeth complications include esophagitis esophageal strictures and barrett s esophagus risk factors include obesity pregnancy smoking hiatus hernia and taking certain medicines medications involved include antihistamines calcium channel blockers antidepressants and sleeping medication it is due to poor closure of the lower esophageal sphincter the junction between the stomach and the esophagus diagnosis among those who do not improve with simply measures may involve gastroscopy upper gi series esophageal ph monitoring or esophageal manometry treatment is typically via lifestyle changes medications and sometimes surgery lifestyle changes include not lying down for three hours after eating losing weight avoiding certain foods and stopping smoking medications include antacid h 2 receptor blockers proton pump inhibitors and prokinetics surgery may be an option in those who do not improve with other measures in the western world between 10 and 20 of the population are affected by gerd gastroesophageal reflux ger once in awhile without significant symptoms or complications is more common the condition was first described in 1935 by asher winkelstein the classic symptoms had been described earlier in 1925
gastrointestinal bleeding gi bleed also known as gastrointestinal hemorrhage is all forms of bleeding in the gastrointestinal tract from the mouth to the rectum when there is significant blood loss over a short time symptoms may include vomiting red blood vomiting black blood bloody stool or black stool small amounts of bleeding over a long time may cause iron deficiency anemia resulting in feeling tired or heart related chest pain other symptoms may include abdominal pain shortness of breath pale skin or passing out sometimes in those with small amounts of bleeding no symptoms may be present bleeding is typically divided into two main types upper gastrointestinal bleeding and lower gastrointestinal bleeding causes of upper gi bleeds include peptic ulcer disease esophageal varices due to liver cirrhosis and cancer among others causes of lower gi bleeds include hemorrhoids cancer and inflammatory bowel disease among others diagnosis typically begins with a medical history and physical examination along with blood tests small amounts of bleeding may be detected by fecal occult blood test endoscopy of the lower and upper gastrointestinal track may locate the area of bleeding medical imaging may be useful in cases that are not clear initial treatment focuses on resuscitation which may include intravenous fluids and blood transfusions often blood transfusions are not recommended unless the hemoglobin is less than 70 or 80 g l treatment with proton pump inhibitors octreotide and antibiotics may be considered in certain cases if other measures are not effective an esophageal balloon may be attempted in those with persumed esophageal varices endoscopy of the esophagus stomach and duodenum or endoscopy of the large bowel are generally recommended within 24 hours and may allow treatment as well as diagnosis an upper gi bleed is more common than lower gi bleed an upper gi bleed occurs in 50 to 150 per 100 000 adults per year a lower gi bleed is estimated to occur in 20 to 30 per 100 000 per year it results in about 300 000 hospital admissions a year in the united states risk of death from a gi bleed is between 5 and 30 risk of bleeding is more common in males and increases with age
gastrointestinal cancer refers to malignant conditions of the gastrointestinal tract gi tract and accessory organs of digestion including the esophagus stomach biliary system pancreas small intestine large intestine rectum and anus the symptoms relate to the organ affected and can include obstruction leading to difficulty swallowing or defecating abnormal bleeding or other associated problems the diagnosis often requires endoscopy followed by biopsy of suspicious tissue the treatment depends on the location of the tumor as well as the type of cancer cell and whether it has invaded other tissues or spread elsewhere these factors also determine the prognosis overall the gi tract and the accessory organs of digestion pancreas liver gall bladder are responsible for more cancers and more deaths from cancer than any other system in the body there is significant geographic variation in the rates of different gastrointestinal cancers
gastrointestinal diseases refer to diseases involving the gastrointestinal tract namely the esophagus stomach small intestine large intestine and rectum and the accessory organs of digestion the liver gallbladder and pancreas
gastrointestinal intraepithelial neoplasia gin or giin also known as digestive epithelial dysplasia is abnormal growth cellular dysplasia of digestive epithelial cells in the digestive mucosa gastrointestinal intraepithelial neoplasia is the potentially premalignant transformation since 2000 they are classified according to the vienna classification
a gastrointestinal neuroectodermal tumor is a neuroectodermal tumor that appears in the gastrointestinal system
gastrointestinal perforation also known as ruptured bowel is a hole in the wall of part of the gastrointestinal tract the gastrointestinal tract includes the esophagus stomach small intestine and large intestine symptoms include severe abdominal pain and tenderness when the hole is in the stomach or early part of the small intestine the onset of pain is typically sudden while with a hole in the large intestine onset may be more gradual the pain is usually constant in nature sepsis with an increased heart rate increased breathing rate fever and confusion may occur the cause can include trauma such as from a knife wound eating a sharp object or a medical procedure such as colonoscopy bowel obstruction such as from a volvulus colon cancer or diverticulitis stomach ulcers ischemic bowel and a number of infections including c difficile a hole allows intestinal contents to enter the abdominal cavity the entry of bacteria results in a condition known as peritonitis or in the formation of an abscess a hole in the stomach can also lead to a chemical peritonitis due to gastric acid a ct scan is typically the preferred method of diagnosis however free air from a perforation can often be seen on plain x ray perforation anywhere along the gastrointestinal tract typically requires emergency surgery in the form of an exploratory laparotomy this is usually carried out along with intravenous fluids and antibiotics a number of different antibiotics may be used such as piperacillin tazobactam or the combination of ciprofloxacin and metronidazole occasionally the hole can be sewn closed while other times a bowel resection is required even with maximum treatment the risk of death can be as high as 50 a hole from a stomach ulcer occurs in about 1 per 10 000 people per year while one from diverticulitis occurs in about 0 4 per 10 000 people per year
gastrointestinal stromal tumors gists are the most common mesenchymal neoplasms of the gastrointestinal tract gists arise in the smooth muscle pacemaker interstitial cell of cajal or similar cells they are defined as tumors whose behavior is driven by mutations in the kit gene 85 pdgfra gene 10 or braf kinase rare 95 of gists stain positively for kit cd 117 most 66 occur in the stomach and gastric gists have a lower malignant potential than tumors found elsewhere in the gi tract
a gastrojejunocolic fistula is a disorder of the human gastrointestinal tract it may form between the transverse colon and the upper jejunum after a billroth ii surgical procedure the billroth procedure attaches the jejunum to the remainder of the stomach fecal matter thereby passes improperly from the colon to the stomach and causes halitosis
gastroparesis gp gastro from ancient greek γαστήρ gaster stomach and πάρεσις paresis partial paralysis also called delayed gastric emptying is a medical condition consisting of a paresis partial paralysis of the stomach resulting in food remaining in the stomach for an abnormally long time normally the stomach contracts to move food down into the small intestine for additional digestion the vagus nerve controls these contractions gastroparesis may occur when the vagus nerve is damaged and the muscles of the stomach and intestines do not properly function food then moves slowly or stops moving through the digestive tract
in medicine gastroptosis is the abnormal downward displacement of the stomach it is not a life threatening condition the condition frequently causes digestive symptoms and constipation and is much more prominent in women than men
gastroschisis represents a congenital defect characterised by a defect in the anterior abdominal wall through which the abdominal contents freely protrude there is no overlying sac or peritoneum and the size of the defect is usually less than 4 centimetres 1 6 in the abdominal wall defect is located at the junction of the umbilicus and normal skin and is almost always to the right of the umbilicus the defect occurs 5 – 8 weeks after conception most likely due to a disruption of the bloodsupply to the developing abdominal wall widespread use of antenatal ultrasound examination and maternal serum alpha fetoprotein msafp screening has made the detection of gastroschisis possible in the second trimester of pregnancy omphalocele is another congenital birth defect but it involves the umbilical cord itself and the organs remain enclosed in visceral peritoneum with omphalocele the defect is usually much larger than in gastroschisis
the gattermann reaction also known as the gattermann aldehyde synthesis is a chemical reaction in which aromatic compounds are formylated by hydrogen cyanide in the presence of a friedel – crafts catalyst e g alcl 3 it is named for the german chemist ludwig gattermann and is similar to the friedel crafts reaction the reaction can be simplified by replacing the hcn alcl 3 combination with zinc cyanide although it is also highly toxic zn cn 2 is a solid making it safer to work with than gaseous hcn additionally because the reaction uses hcl zn cn 2 also supplies the reaction with zncl 2 in situ where it acts as a lewis acid catalyst examples of zn cn 2 being used in this way include the synthesis of 2 hydroxy 1 nafthaldehyde and mesitaldehyde
gaucher s disease or gaucher disease ɡoʊˈʃeɪ gd is a genetic disorder in which glucocerebroside a sphingolipid also known as glucosylceramide accumulates in cells and certain organs the disorder is characterized by bruising fatigue anemia low blood platelet count and enlargement of the liver and spleen and is caused by a hereditary deficiency of the enzyme glucocerebrosidase also known as glucosylceramidase which acts on glucocerebroside when the enzyme is defective glucocerebroside accumulates particularly in white blood cells and especially in macrophages mononuclear leukocytes glucocerebroside can collect in the spleen liver kidneys lungs brain and bone marrow manifestations may include enlarged spleen and liver liver malfunction skeletal disorders or bone lesions that may be painful severe neurological complications swelling of lymph nodes and occasionally adjacent joints distended abdomen a brownish tint to the skin anemia low blood platelet count and yellow fatty deposits on the white of the eye sclera persons seriously affected may also be more susceptible to infection some forms of gaucher s disease may be treated with enzyme replacement therapy the disease is caused by a recessive mutation in the gba gene located on chromosome 1 and affects both males and females about one in 100 people in the united states are carriers of the most common type of gaucher disease the carrier rate among ashkenazi jews is 8 9 while the birth incidence is one in 450 gaucher s disease is the most common of the lysosomal storage diseases it is a form of sphingolipidosis a subgroup of lysosomal storage diseases as it involves dysfunctional metabolism of sphingolipids the disease is named after the french physician philippe gaucher who originally described it in 1882
in algebra in the theory of polynomials a subfield of ring theory gauss s lemma is either of two related statements about polynomials with integer coefficients the first result states that the product of two primitive polynomials is primitive a polynomial with integer coefficients is called primitive if the greatest common divisor of its coefficients is 1 the second result states that if a non constant polynomial with integer coefficients is irreducible over the integers then it is also irreducible if it is considered as a polynomial over the rationals this second statement is a consequence of the first see proof below the first statement and proof of the lemma is in article 42 of carl friedrich gauss s disquisitiones arithmeticae 1801 this statements have several generalizations described below
in mathematics the gauss circle problem is the problem of determining how many integer lattice points there are in a circle centred at the origin and with radius r the first progress on a solution was made by carl friedrich gauss hence its name
geminal halide hydrolysis is an organic reaction the reactants are geminal dihalides with a water molecule or a hydroxide ion the reaction yields ketones from secondary halides or aldehydes from primary halides
gender hci is a subfield of human computer interaction that focuses on the design and evaluation of interactive systems for humans with emphasis on differences in how males and females interact with computers
gender and judaism is an emerging subfield at the intersection of gender studies and jewish studies gender studies centers on interdisciplinary research on the phenomenon of gender it focuses on cultural representations of gender and people s lived experience jewish studies is a field that looks at jews and judaism through such disciplines as history anthropology literary studies linguistics and sociology
gender and security sector reform is an emerging subfield of security sector reform ssr that is both practical and conceptual ssr generally is a comprehensive framework within which all or part of a state s security sector undergoes a process of transformation in order to bring it more into line with principles such as democratic oversight good governance and the rule of law the overall objectives of ssr programmes – as defined both by the state in question and any international donors supporting the process – tend to include improving service delivery enhancing local ownership and ensuring the sustainability of security sector institutions as gender specific approaches take into account the specific needs of men women boys and girls through gender mainstreaming and by promoting the equal participation of people of all genders in decision making processes states and international organisations increasingly consider them to be a necessary component of ssr programmes
health is the general condition of a person s mind and body usually indicating the state of being free from illness injury or pain the world health organization who has defined health as a state of complete physical mental and social well being and not merely the absence of disease or infirmity identified by the 2012 world development report as one of two key human capital endowments health can influence an individual ’ s ability to reach his or her full potential in society yet while gender equality has made the most progress in areas such as education and labor force participation health inequality between men and women continues to plague many societies today while both males and females face health disparities girls and women experience a majority of health disparities this comes from the fact that many cultural ideologies and practices have structured society in a way whereby women are more vulnerable to abuse and mistreatment making them more prone to illnesses and early death women are also restricted from receiving many opportunities such as education and paid labor that can help improve their accessibility to better health care resources
gender dysphoria or gender identity disorder gid is the dysphoria distress a person experiences as a result of the sex and gender they were assigned at birth there is evidence suggesting that people who identify with a gender different from the one they were assigned at birth may do so not just due to psychological or behavioral causes but also biological ones related to their genetics or exposure to hormones before birth estimates of the prevalence of gender dysphoria or gid range from a lower bound of 1 2000 or about 0 05 in the netherlands and belgium to 0 5 of massachusetts adults to 1 2 of new zealand high school students these numbers are based on those who identify as transgender it is estimated that about 0 005 to 0 014 of males and 0 002 to 0 003 of females would be diagnosed with gender dysphoria based on current diagnostic criteria research indicates people who transition in adulthood are up to three times more likely to be male assigned at birth but that among people transitioning in childhood the sex ratio is close to 1 1 gid is classified as a disorder by the icd 10 cm and dsm 5 called gender dysphoria some transgender people and researchers support declassification of gid because they say the diagnosis pathologizes gender variance reinforces the binary model of gender and can result in stigmatization of transgender individuals the official reclassification as gender dysphoria in the dsm 5 may help resolve some of these issues because the term gender dysphoria applies only to the discontent experienced by some persons resulting from gender identity issues the american psychiatric association publisher of the dsm 5 states that gender nonconformity is not in itself a mental disorder the critical element of gender dysphoria is the presence of clinically significant distress associated with the condition the current main psychiatric approaches to treatment for persons diagnosed with gid are psychotherapy or to support the individual s preferred gender through hormone therapy gender expression and role or surgery
gender dysphoria in children or gender identity disorder in children gidc is a formal diagnosis used by psychologists and physicians to describe children who experience significant discontent gender dysphoria with their biological sex assigned gender or both gidc was formalized in the third revision of the diagnostic and statistical manual of mental disorders dsm iii in 1980 and primarily referenced gender non conforming behaviors gidc remained in the dsm from 1980 to 2013 when it was replaced with the diagnosis of gender dysphoria in the fifth revision dsm 5 in an effort to diminish the stigma attached to gender variance while maintaining a diagnostic route to gender affirming medical interventions such as hormone therapy and surgery controversy surrounding the pathologization and treatment of cross gender identity and behaviors particularly in children has been evident in the literature since the 1980 s proponents of more widespread gidc diagnoses argue that therapeutic intervention helps children be more comfortable in their bodies and can prevent adult gender identity disorder opponents say that the equivalent therapeutic interventions with gays and lesbians titled conversion or reparative therapy have been strongly questioned or declared unethical by the american psychological association american psychiatric association american association of social workers and american academy of pediatrics the world professional association for transgender health wpath states that treatment aimed at trying to change a person s gender identity and expression to become more congruent with sex assigned at birth is no longer considered ethical critics also argue that the gidc diagnosis and associated therapeutic interventions rely on the assumption that an adult transsexual identity is undesirable challenging this assumption along with the lack of clinical data to support outcomes and efficacy gender identity disorder in children is more heavily linked with adult homosexuality than adult transsexualism according to limited studies the majority of children diagnosed with gid cease to desire to be the other sex by puberty with most growing up to identify as gay or lesbian with or without therapeutic intervention
the gender paradox is a sociolinguistic phenomenon first observed by william labov in which women conform more closely than men to sociolinguistic norms that are overtly prescribed but conform less than men when they are not specifically the paradox arises from sociolinguistic data showing that women are more likely to use prestige forms and avoid stigmatized variants than men for a majority of linguistic variables but that they are also more likely to lead language change by using innovative forms of variables
the european commission defines the gender pay gap as the average difference between men s and women s aggregate hourly earnings the wage gap is due to a variety of causes such as differences in education choices differences in preferred job and industry differences in the types of positions held by men and women differences in the type of jobs men typically go into as opposed to women especially highly paid high risk jobs differences in amount of work experience difference in length of the work week and breaks in employment these factors resolve 60 to 75 of the pay gap depending on the source various explanations for the remaining 25 to 40 have been suggested including women s lower willingness and ability to negotiate salaries or else due to discrimination according to the european commission direct discrimination only explains a small part of gender wage differences in the united states the average female s unadjusted annual salary has been cited as 78 of that of the average male however multiple studies from oecd aauw and the us department of labor have found that pay rates between males and females varied by 5 – 6 6 or females earning 94 cents to every dollar earned by their male counterparts when wages were adjusted to different individual choices made by male and female workers in college major occupation working hours and maternal paternal leave the remaining 6 of the gap has been speculated to originate from deficiency in salary negotiating skills and sexual discrimination in the uk the aggregate gender pay gap has continued to close and as of 2012 the gap officially dropped below 10 for full time workers the aggregate gender pay gap can also be viewed as a generational sliding scale with females between 55 – 65 with the largest disparity 18 and females between the ages of 25 – 35 with the smallest disparity 6
australia has a persistent gender pay gap since 1990 the gender pay gap remained within a narrow range of between 15 and 18 in november 2015 the australian gender pay gap was 17 21 however it has been noted that some of this gap could be down to differing career choices between the genders as this is an aggregate figure with some sources citing an actual pay gap for equal work of below 3
the gender pay gap in new zealand is the difference in the average hourly wages of men and women in new zealand it is calculated using the median hourly wage paid to full time male and female workers an economic indicator of gender inequality a gender pay gap suggests a failure to ensure the principles of pay equality and equal pay for equal work
cancer is a disease characterized by uncontrolled cell growth and proliferation for cancer to develop genes regulating cell growth and differentiation must be altered these mutations are then maintained through subsequent cell divisions and are thus present in all cancerous cells gene expression profiling is a technique used in molecular biology to query the expression of thousands of genes simultaneously in the context of cancer gene expression profiling has been used to more accurately classify tumors the information derived from gene expression profiling often helps in predicting the patient ’ s clinical outcome
gene gating is a phenomenon by which transcriptionally active genes are brought next to nuclear pore complexes npcs so that nascent transcripts can quickly form mature mrna associated with export factors gene gating was first hypothesised by günter blobel in 1985 it has been shown to occur in saccharomyces cerevisiae caenorhabditis elegans drosophila melanogaster as well as mammalian model systems the proteins that consitute the npcs known as nucleoporins have been shown to play a role in dna binding and mrna transport making gene gating possible in addition gene gating is orchestrated by two protein complexes spt ada gcn 5 acetyltransferase saga and transcription – export complex 2 trex 2 complex saga is a chromatin remodeling complex responsible for activating the transcription of certain inducible genes the saga complex binds to gene promoters and also interacts with the trex 2 complex in turn the trex 2 complex interacts with the npc thus favouring the relocation of actively transcribed genes to the periphery of the cell nucleus in contrast the rest of the periphery i e those parts not associated with npcs is transcriptionally silent heterochromatin
the genealogy of musical genres is the pattern of musical genres that have contributed to the development of new genres genealogical charts or family trees of musical genres show how new genres have emerged from existing genres and how multiple genres have contributed to a new genre since music can be endlessly broken down into smaller and smaller categories a genealogical chart will usually focus on one major genre and its different strains for instance jazz is considered to be a genre with many subgenres including new orleans jazz ragtime swing bebop free jazz and latin jazz how these developed out of one another is shown in a genealogical chart often with major figures or innovators of each subgenre a genealogy of genres may also incorporate several major genres such as jazz rock and roll and folk music the image accompanying this article shows how numerous cuban musical styles have developed out of many other genres including some from europe africa the us latin america and other caribbean countries while focusing on cuban music the image also shows the genealogy of many popular music genres since the 18 th century the family tree of music can also be explored by starting at the article for your favourite genre and clicking on the items in the stylistic origins subgenres derivative forms and fusion genres sections of the genre infobox
generación de la ruptura breakaway generation was a reaction of the post world war ii generation of mexican artists against the established mexican school of painting more commonly called mexican muralism it began with the criticisms of josé luis cuevas in the early 1950 s followed by others who thought the established art had become dogmatic formulaic and nationalistic and the artists too deferential to the government this new generation of artists was not bound by a particular artistic style but was more interested in personal rather than social issues and influenced by a number of international trends in art such as abstract expressionism early reaction to them was strong and negative but by the end of the 1950 s they had succeeded in having their art shown in the major venues of mexico the generación de la ruptura had influence on other arts in mexico such as literature but it did not end the production of murals in mexico with social and nationalist purposes
the general group problem solving ggps model is a problem solving methodology in which a group of individuals will define the desired outcome identify the gap between the current state and the target and generate ideas for closing the gap by brainstorming the end result is list of actions needed to achieve the desired results
general paresis also known as general paralysis of the insane or paralytic dementia is a severe neuropsychiatric disorder classified as an organic mental disorder and caused by the chronic meningoencephalitis that leads to cerebral atrophy in late stage syphilis degenerative changes are associated primarily with the frontal and temporal lobar cortex the disease affects approximately 7 of infected individuals it prevails among men gpi was originally considered to be a type of madness due to a dissolute character when first identified in the 18 th century then the cause effect connection with syphilis was discovered in the late 1880 s subsequently the discovery of penicillin and its use in the treatment of syphilis rendered paresis curable and avoidable prior to that paresis was inevitably fatal unless another terminating illness intervened and accounted for as much as 25 of the primary diagnosis for residents in public psychiatric hospitals
generalized epilepsy also known as primary generalized epilepsy or idiopathic epilepsy is a form of epilepsy characterised by generalised seizures with no apparent cause generalized seizures as opposed to partial seizures are a type of seizure that impairs consciousness and distorts the electrical activity of the whole or a larger portion of the brain which can be seen for example on electroencephalography eeg generalized epilepsy is primary because the epilepsy is the originally diagnosed condition itself as opposed to secondary epilepsy which occurs as a symptom of a diagnosed condition
tonic – clonic seizures formerly known as grand mal seizures are a type of generalized seizure that affects the entire brain tonic – clonic seizures are the seizure type most commonly associated with epilepsy and seizures in general though it is a misconception that they are the only type tonic – clonic seizures can be induced deliberately in electroconvulsive therapy
generalized anxiety disorder gad is an anxiety disorder characterized by excessive uncontrollable and often irrational worry that is apprehensive expectation about events or activities this excessive worry often interferes with daily functioning as individuals with gad typically anticipate disaster and are overly concerned about everyday matters such as health issues money death family problems friendship problems interpersonal relationship problems or work difficulties individuals often exhibit a variety of physical symptoms including fatigue fidgeting headaches nausea numbness in hands and feet muscle tension muscle aches difficulty swallowing excessive stomach acid buildup stomach pain vomiting diarrhea bouts of breathing difficulty difficulty concentrating trembling twitching irritability agitation sweating restlessness insomnia hot flashes rashes and inability to fully control the anxiety icd 10 these symptoms must be consistent and ongoing persisting at least six months for a formal diagnosis of gad standardized rating scales such as gad 7 can be used to assess severity of gad symptoms gad is the most common cause of disability in the workplace in the united states in a given year approximately two percent of american adults and european adults experience gad globally about 4 are affected at some point in their life gad is seen in women twice as much as men gad is also common in individuals with a history of substance abuse and a family history of the disorder once gad develops it may become chronic but can be managed or eliminated with proper treatment
in applied mathematics the maximum generalized assignment problem is a problem in combinatorial optimization this problem is a generalization of the assignment problem in which both tasks and agents have a size moreover the size of each task might vary from one agent to the other this problem in its most general form is as follows there are a number of agents and a number of tasks any agent can be assigned to perform any task incurring some cost and profit that may vary depending on the agent task assignment moreover each agent has a budget and the sum of the costs of tasks assigned to it cannot exceed this budget it is required to find an assignment in which all agents do not exceed their budget and total profit of the assignment is maximized
generalized epilepsy with febrile seizures plus gefs is a syndromic autosomal dominant disorder where afflicted individuals can exhibit numerous epilepsy phenotypes gefs can persist beyond early childhood i e 6 years of age gefs is also now believed to encompass three other epilepsy disorders severe myoclonic epilepsy of infancy smei which is also known as dravet s syndrome borderline smei smeb and intractable epilepsy of childhood iec there are at least six types of gefs delineated by their causative gene known causative genes are the sodium channel α subunit genes scn 1 a an associated β subunit scn 1 b and a gabaa receptor γ subunit gene gabrg 2 and there is another gene related with calcium channel the pcdh 19 which is also known as epilepsy female with mental retardation penetrance for this disorder is estimated at approximately 60
generalized eruptive histiocytoma also known as eruptive histiocytoma and generalized eruptive histiocytosis is a rare cutaneous condition characterized by widespread erythematous essentially symmetrical papules particularly involving the trunk and proximal extremities
generalized erythema is a skin condition that may be caused by medications bacterial toxins or viral infections
in computational complexity theory generalized geography is a well known pspace complete problem
generalized granuloma annulare is a skin condition of unknown cause tending to affect women in the fifth and sixth decades presenting as a diffuse but symmetrical papular or annular eruption of more than ten skin lesions and often hundreds
generalized hyperhidrosis is excessive sweating that may be induced by febrile diseases vigorous exercise or a hot humid environment such as a tropical milieu
generalized lentiginosis is a cutaneous condition that will occasionally present without other associated abnormalities it may be caused by carney complex leopard syndrome or peutz – jeghers syndrome
lymph nodes or glands or nodes or lymphoid tissue are nodular bodies located throughout the body but clustering in certain areas such as the armpit back of the neck and the groin they are part of the lymphatic system the lymphatic system is part of the body s immune surveillance system blood contains fluid and blood cells the fluid which may contain suspended foreign material such as bacteria and viruses seeps through blood vessel walls into the tissues where it bathes the body cells and exchanges substances with them some of this fluid is then taken up by lymphatic vessels and passed back to the heart where it is again mixed with the blood on its way the fluid passes through the lymph nodes if nodes detect something foreign passing through them such as a bacterium or a cancer cell they will swell up this is called lymphadenopathy or swollen glands usually this is localised for example an infected spot on the scalp will cause lymph nodes in the neck on that same side to swell up but when it is in two or more regions it is called generalized lymphadenopathy usually this is in response to a body wide infectious disease such as influenza and will go away once the person has recovered but sometimes it can persist long term even when there is no obvious cause of disease this is then called persistent generalized lymphadenopathy pgl
generalized pustular psoriasis gpp is an extremely rare type of psoriasis that can present in a variety of forms unlike the most general and common forms of psoriasis gpp usually covers the entire body and with pus filled blisters rather than plaques gpp can present at any age but is rarer in young children it can appear with or without previous psoriasis conditions or history and can reoccur in periodic episodes
in mathematics a semi infinite programming sip problem is an optimization problem with a finite number of variables and an infinite number of constraints the constraints are typically parameterized in a generalized semi infinite programming gsip problem the feasible set of the parameters depends on the variables
generalized vaccinia is a cutaneous condition that occurs 6 – 9 days after vaccination characterized by a generalized eruption of skin lesions and caused by the vaccinia virus
the generation effect is a phenomenon where information is better remembered if it is generated from one s own mind rather than simply read researchers have struggled to account for why generated information is better recalled than read information but no single explanation has been sufficient
a generation gap or generational gap is a difference of opinions between one generation and another regarding beliefs politics or values in today s usage generation gap often refers to a perceived gap between younger people and their parents and or grandparents
generation gap is a software design pattern documented by john vlissides that treats automatically generated code differently than code that was written by a developer modifications should not be made to generated code as they would be overwritten if the code generation process was ever re run such as during recompilation vlissides proposed creating a subclass of the generated code which contains the desired modification
generation loss is the loss of quality between subsequent copies or transcodes of data anything that reduces the quality of the representation when copying and would cause further reduction in quality on making a copy of the copy can be considered a form of generation loss file size increases are a common result of generation loss as the introduction of artifacts may actually increase the entropy of the data through each generation
generic case complexity is a subfield of computational complexity theory that studies the complexity of computational problems on most inputs generic case complexity is a way of measuring the complexity of a computational problem by neglecting a small set ofunrepresentative inputs and considering worst case complexity on the rest small is defined in terms of asymptotic density the apparent efficacy of generic case complexity is because for a wide variety of concrete computational problems the most difficult instances seem to be rare typical instances are relatively easy this approach to complexity originated in combinatorial group theory which has a computational tradition going back to the beginning of the last century the notion of generic complexity was introduced in a 2003 paper where authors showed that for a large class of finitely generated groups the generic time complexity of some classical decision problems from combinatorial group theory namely the word problem conjugacy problem and membership problem are linear a detailed introduction of generic case complexity can be found in the surveys
a genetic disorder is a genetic problem caused by one or more abnormalities in the genome especially a condition that is present from birth congenital most genetic disorders are quite rare and affect one person in every several thousands or millions genetic disorders may be hereditary passed down from the parents genes in other genetic disorders defects may be caused by new mutations or changes to the dna in such cases the defect will only be passed down if it occurs in the germ line the same disease such as some forms of cancer may be caused by an inherited genetic condition in some people by new mutations in other people and mainly by environmental causes in other people whether when and to what extent a person with the genetic defect or abnormality will actually suffer from the disease is almost always affected by the environmental factors and events in the person s development some types of recessive gene disorders confer an advantage in certain environments when only one copy of the gene is present
genetic gain is the amount of increase in performance that is achieved through artificial genetic improvement programs this is usually used to refer to the increase after one generation has passed
genetic heterogeneity is a phenomenon in which a single phenotype or genetic disorder may be caused by any one of a multiple number of alleles or non allele locus mutations this is in contrast to pleiotropy where a single gene may cause multiple phenotypic expressions or disorders genetic heterogeneity describes genetic variation from the normal population clinically genetic heterogeneity refers to diseases that result from multiple gene abnormalities multiple gene abnormalities are seen in disorders such as autism cystic fibrosis and retinitis pigmentosa
genetic load is the difference between the fitness of an average genotype in a population and the fitness of some reference genotype which may be either the best present in a population or may be the theoretically optimal genotype the average individual taken from a population with a low genetic load will generally when grown in the same conditions have more surviving offspring genetic load can also be seen as reduced fitness at the population level compared to what the population would have if all individuals had the reference high fitness genotype high genetic load may put a population in danger of extinction
genetic variability vary liable to or capable of change is the ability i e capability of a biological system – individual and population – that is changing over time the base of the genetic variability is genetic variation of different biological systems in space genetic variability is a measure of the tendency of individual genotypes in a population to vary from one another also variability is different from genetic diversity which is the amount of variation seen in a particular population the variability of a trait describes how much that trait tends to vary in response to environmental and genetic influences genetic variability in a population is important for biodiversity because without variability it becomes difficult for a population to adapt to environmental changes and therefore makes it more prone to extinction variability is an important factor in evolution as it affects an individual s response to environmental stress and thus can lead to differential survival of organisms within a population due to natural selection of the most fit variants genetic variability also underlies the differential susceptibility of organisms to diseases and sensitivity to toxins or drugs — a fact that has driven increased interest in personalized medicine given the rise of the human genome project and efforts to map the extent of human genetic variation such as the hapmap project
down syndrome is a chromosomal abnormality characterized by the presence of an extra copy of genetic material on the 21 st chromosome either in whole trisomy 21 or part such as due to translocations the effects of the extra copy varies greatly from individual to individual depending on the extent of the extra copy genetic background environmental factors and random chance down syndrome can occur in all human populations and analogous effects have been found in other species such as chimpanzees and mice recently researchers have been able to create transgenic mice with most of human chromosome 21 in addition to their normal chromosomes a typical human karyotype is shown here every chromosome has two copies in the bottom right there are chromosomal differences between males xy and females xx which do not concern us a typical human karyotype is designated as 46 xx or 46 xy indicating 46 chromosomes with an xx arrangement for females and 46 chromosomes with an xy arrangement for males for this section we will use females for the karyotype designation 46 xx
cancer is a genetic disorder in which the normal control of cell growth is lost cancer genetics is now one of the fastest expanding medical specialties at the molecular level cancer is caused by mutation s in dna which result in aberrant cell proliferation most of these mutations are acquired and occur in somatic cells however some people inherit mutation s in the germline the mutation s occur in two classes of cellular genes oncogenes and tumor suppressor genes transformation of proto oncogene to oncogene is the result of gain in function through over expression of the gene or duplication such as amplification to produce increased onco protein activation or formation of fusion gene by translocation alteration of the gene product to produce transforming proteins
geniculate ganglionitis or geniculate neuralgia gn also called nervus intermedius neuralgia is a rare disorder that involves severe pain deep in the ear that may spread to the ear canal outer ear mastoid or eye regions gn may also occur in combination with trigeminal or glossopharyngeal neuralgia the pain of gn is sharp shooting or burning and can last for hours painful attacks can be triggered by cold noise swallowing or touch but triggers are usually unique to the sufferer other related symptoms that may be experienced include increased salivation bitter taste tinnitus and vertigo this disorder usually occurs in young to middle aged adults and more commonly in women geniculate neuralgia may be caused by compression of somatic sensory branch of cranial nerve vii which goes through the nervus intermedius in sufferers of gn signals sent along these nerves are altered and interpreted by the geniculate ganglion a structure in the brain as gn pain gn may also develop following herpes zoster oticus ramsay hunt syndrome where cold sores occur on the ear drum or ear this may also be associated with facial paresis weakness tinnitus vertigo and deafness
geniospasm is movement disorder of the mentalis muscle it is a benign genetic disorder linked to chromosome 9 q 13 q 21 where there are episodic involuntary up and down movements of the chin and lower lip the movements consist of rapid fluttering or trembling at about 8 hz superimposed onto a once per three seconds movement of higher amplitude and occur symmetrically in the v shaped muscle the tongue and buccal floor muscles may also be affected but to a much lesser degree the movements are always present but extreme episodes may be precipitated by stress concentration or emotion and commence in early childhood the condition is extremely rare and in a study in 1999 only 23 families in the world were known to be affected although it may be under reported inheritance is aggressively autosomal dominant in at least two studies the condition appeared spontaneously in the families the condition responds very well to regular botulinus toxin injections into the mentalis muscle which paralyse the muscle but cause no impairment of facial expression or speech
genital herpes is a genital infection caused by the herpes simplex virus hsv most individuals carrying herpes are unaware they have been infected and many will never suffer an outbreak which involves blisters similar to cold sores while there is no cure for herpes over time symptoms are increasingly mild and outbreaks are decreasingly frequent when symptomatic the typical manifestation of a primary infection is clusters of genital sores consisting of inflamed papules and vesicles on the outer surface of the genitals resembling cold sores these usually appear 4 – 7 days after sexual exposure to hsv for the first time genital hsv 1 infection recurs at rate of about one sixth of that of genital hsv 2 hsv has been classified into two distinct categories hsv 1 and hsv 2 although genital herpes was previously caused primarily by hsv 2 genital hsv 1 infections are increasing and now cause up to 80 of infections in 2013 about 1 1 billion people 15 9 had asymptomatic genital herpes and 47 million new cases of genital herpes occurred a 1998 study indicated it was the most common sexually transmitted infection by the number of cases
genital warts are symptoms of a contagious sexually transmitted disease caused by some types of human papillomavirus hpv warts are the most easily recognized symptom of genital hpv infection about 90 of those who contract hpv will not develop genital warts and the remaining 10 who are infected can transmit the virus hpv types 6 and 11 are most frequently the cause of genital warts it is spread through direct skin to skin contact usually during oral genital or anal sex with an infected partner while some types of hpv cause cervical cancer and anal cancers these are not the same types of hpv that cause genital warts the some hpv vaccines includes coverage for types 6 and 11 and therefore can prevent genital warts it is also possible to be infected with different types of hpv either at the same or different times although estimates of the number of new cases a year vary hpv is so common that nearly all sexually active people will get it at some point in their lives a condyloma acuminatum is a single genital wart and condylomata acuminata are multiple genital warts the word roots mean pointed wart from greek κόνδυλος knuckle greek ωμα oma disease and latin acuminatum pointed although similarly named it is not the same as condyloma latum which is a complication of secondary syphilis
in 2012 it was shown that mutations in the gene kat 6 b cause the syndrome
genitourinary amoebiasis or renal amoebiasis is a rare complication to amoebic liver abscess which in turn is a complication of amoebiasis it is believed to result from liver abscesses breaking open whereupon the amoebas spread through the blood to the new locale genital involvement is thought to result from fistula formation from the liver or through rectocolitis the involvement causes lesions which exude a high degree of pus
genocopy is a trait that is a phenotypic copy of a genetic trait but is caused by a different genotype a genotype at one locus that produces a phenotype that at some levels of resolution is indistinguishable from that produced by another genotype two types of elliptocytosis that are genocopies of each other but are distinguished by the fact that one is linked to the rh blood group locus and the other is not the way to distinguish a recessive genocopy from a phenotype caused by a different allele would be by carrying out a test cross breeding the two together if they f 1 hybrid segregates 1 2 1 then we can determine that it was a genocopy
genodermatoses are inherited genetic skin conditions often grouped into three categories chromosomal single gene and polygenetic
genome size is the total amount of dna contained within one copy of a single genome it is typically measured in terms of mass in picograms trillionths 10 − 12 of a gram abbreviated pg or less frequently in daltons or as the total number of nucleotide base pairs typically in megabases millions of base pairs abbreviated mb or mbp one picogram equals 978 megabases in diploid organisms genome size is used interchangeably with the term c value an organism s complexity is not directly proportional to its genome size some single cell organisms have much more dna than humans see junk dna and c value enigma
genomic imprinting is the epigenetic phenomenon by which certain genes are expressed in a parent of origin specific manner if the allele inherited from the father is imprinted it is thereby silenced and only the allele from the mother is expressed if the allele from the mother is imprinted then only the allele from the father is expressed forms of genomic imprinting have been demonstrated in fungi plants and animals as of 2014 there are about 150 imprinted genes known in the mouse and about half that in humans genomic imprinting is an inheritance process independent of the classical mendelian inheritance it is an epigenetic process that involves dna methylation and histone methylation without altering the genetic sequence these epigenetic marks are established imprinted in the germline sperm or egg cells of the parents and are maintained through mitotic cell divisions in the somatic cells of an organism appropriate imprinting of certain genes is important for normal development human diseases involving genomic imprinting include angelman syndrome and prader – willi syndrome
genu recurvatum is a deformity in the knee joint so that the knee bends backwards in this deformity excessive extension occurs in the tibiofemoral joint genu recurvatum is also called knee hyperextension and back knee this deformity is more common in women and people with familial ligamentous laxity hyperextension of the knee may be mild moderate or severe the normal range of motion rom of the knee joint is from 0 to 135 degrees in an adult full knee extension should be no more than 10 degrees in genu recurvatum back knee normal extension is increased the development of genu recurvatum may lead to knee pain and knee osteoarthritis
genu valgum commonly called knock knee is a condition in which the knees angle in and touch one another when the legs are straightened individuals with severe valgus deformities are typically unable to touch their feet together while simultaneously straightening the legs the term originates from the latin genu knee and valgus which actually means bent outwards but in this case it is used to describe the distal portion of the knee joint which bends outwards and thus the proximal portion seems to be bent inwards for citation and more information on uses of the words valgus and varus please visit the internal link to varus mild genu valgum is diagnosed when a person standing upright with the feet touching also shows the knees touching it can be seen in children from ages 2 to 5 and is often corrected naturally as children grow however the condition may continue or worsen with age particularly when it is the result of a disease such as rickets or obesity idiopathic genu valgum is a form that is either congenital or has no known cause other systemic conditions may be associated such as schnyder crystalline corneal dystrophy an autosomal dominant condition frequently reported with hyperlipidemia
genu varum also called bow leggedness bandiness bandy leg and tibia vara is a physical deformity marked by outward bowing of the lower leg in relation to the thigh giving the appearance of an archer s bow usually medial angulation of both femur and tibia is involved
in mathematics — specifically in differential geometry — a geodesic map or geodesic mapping or geodesic diffeomorphism is a function that preserves geodesics more precisely given two pseudo riemannian manifolds m g and n h a function φ m → n is said to be a geodesic map if φ is a diffeomorphism of m onto n and the image under φ of any geodesic arc in m is a geodesic arc in n and the image under the inverse function φ − 1 of any geodesic arc in n is a geodesic arc in m
geodynamics is a subfield of geophysics dealing with dynamics of the earth it applies physics chemistry and mathematics to the understanding of how mantle convection leads to plate tectonics and geologic phenomena such as seafloor spreading mountain building volcanoes earthquakes faulting and so on it also attempts to probe the internal activity by measuring magnetic fields gravity and seismic waves as well as the mineralogy of rocks and their isotopic composition methods of geodynamics are also applied to exploration of other planets
geographic tongue also known by several other terms is an inflammatory condition of the mucous membrane of the tongue usually on the dorsal surface it is a common condition affecting approximately 2 – 3 of the general population it is characterized by areas of smooth red depapillation loss of lingual papillae which migrate over time the name comes from the map like appearance of the tongue with the patches resembling the islands of an archipelago the cause is unknown but the condition is entirely benign importantly it does not represent oral cancer and there is no curative treatment uncommonly geographic tongue may cause a burning sensation on the tongue for which various treatments have been described with little formal evidence of efficacy
the geology of british columbia is a function of its location on the leading edge of the north american continent the mountainous physiography and the diversity of rock types and ages hint at the complex geology which is still undergoing revision despite a century of exploration and mapping the country s most prominent geological features are mountain ranges including the north american cordillera which stretches from southern mexico to alaska
a geomagnetic storm is a temporary disturbance of the earth s magnetosphere caused by a solar wind shock wave and or cloud of magnetic field that interacts with the earth s magnetic field the increase in the solar wind pressure initially compresses the magnetosphere the solar wind s magnetic field interacts with the earth ’ s magnetic field and transfers an increased energy into the magnetosphere both interactions cause an increase in plasma movement through the magnetosphere driven by increased electric fields inside the magnetosphere and an increase in electric current in the magnetosphere and ionosphere during the main phase of a geomagnetic storm electric current in the magnetosphere creates a magnetic force that pushes out the boundary between the magnetosphere and the solar wind the disturbance in the interplanetary medium that drives the storm may be due to a solar coronal mass ejection cme or a high speed stream co rotating interaction region or cir of the solar wind originating from a region of weak magnetic field on the sun ’ s surface the frequency of geomagnetic storms increases and decreases with the sunspot cycle cme driven storms are more common during the maximum of the solar cycle while cir driven storms are more common during the minimum of the solar cycle several space weather phenomena tend to be associated with or are caused by a geomagnetic storm these include solar energetic particle sep events geomagnetically induced currents gic ionospheric disturbances that cause radio and radar scintillation disruption of navigation by magnetic compass and auroral displays at much lower latitudes than normal in 1989 a geomagnetic storm energized ground induced currents that disrupted electric power distribution throughout most of the province of quebec and caused aurorae as far south as texas
geomagnetically induced currents gic affecting the normal operation of long electrical conductor systems are a manifestation at ground level of space weather during space weather events electric currents in the magnetosphere and ionosphere experience large variations which manifest also in the earth s magnetic field these variations induce currents gic in conductors operated on the surface of earth electric transmission grids and buried pipelines are common examples of such conductor systems gic can cause problems such as increased corrosion of pipeline steel and damaged high voltage power transformers gic are one possible consequence of geomagnetic storms which may also affect geophysical exploration surveys and oil and gas drilling operations
geomelophagia is an unusual pica medical eating disorder in iron deficiency anemia and is characterized by abnormal ingestion of raw potatoes
in classical and quantum mechanics the geometric phase pancharatnam – berry phase named after s pancharatnam and sir michael berry pancharatnam phase or most commonly berry phase is a phase difference acquired overthe course of a cycle when a system is subjected to cyclic adiabatic processes which results from the geometrical properties of the parameter space of the hamiltonian the phenomenon was first discovered in 1956 and rediscovered in 1984 it can be seen in the aharonov – bohm effect and in the conical intersection of potential energy surfaces in the case of the aharonov – bohm effect the adiabatic parameter is the magnetic field enclosed by two interference paths and it is cyclic in the sense that these two paths form a loop in the case of the conical intersection the adiabatic parameters are the molecular coordinates apart from quantum mechanics it arises in a variety of other wave systems such as classical optics as a rule of thumb it can occur whenever there are at least two parameters characterizing a wave in the vicinity of some sort of singularity or hole in the topology two parameters are required because either the set of nonsingular states will not be simply connected or there will be nonzero holonomy waves are characterized by amplitude and phase and both may vary as a function of those parameters the geometric phase occurs when both parameters are changed simultaneously but very slowly adiabatically and eventually brought back to the initial configuration in quantum mechanics this could involve rotations but also translations of particles which are apparently undone at the end one might expect that the waves in the system return to the initial state as characterized by the amplitudes and phases and accounting for the passage of time however if the parameter excursions correspond to a loop instead of a self retracing back and forth variation then it is possible that the initial and final states differ in their phases this phase difference is the geometric phase and its occurrence typically indicates that the system s parameter dependence is singular its state is undefined for some combination of parameters to measure the geometric phase in a wave system an interference experiment is required the foucault pendulum is an example from classical mechanics that is sometimes used to illustrate the geometric phase this mechanics analogue of the geometric phase is known as the hannay angle
geophotography also geo photography or geological photography is a subfield of geology that involves the use of photography or other imaging techniques in the visible or near visible e g ultraviolet infrared spectrum to realistically record objects features and processes of geological significance ultimately geophotography is motivated by a scientific comprehension or question and serves to accomplish a specific useful goal in furthering the understanding of the aspect of geology that it addresses however crossover does occur from documentary to more artistic styles as geology is broadly the study of the earth and often entails the study of large scale features such as mountains and mountain belts there is significant overlap between geophotography and landscape photography especially
geopotential function is a function that at each point is equal to a constant minus the energy that would be acquired by a unit mass in falling from rest at infinity to the point in question the gradient of the geopotential function which can be obtained by vector calculus yields the earth s gravitational field
george vanden bempde earlier johnstone 29 may 1720 – 29 april 1792 3 rd marquess of annandale succeeded james johnstone 2 nd marquess of annandale on his death in 1730 but in practice from 1733 and enjoyed that title from then to his own death whereupon the title became extinct his change of surname from johnstone to vanden bempde was a condition of receiving an inheritance from john vanden bempde and was confirmed by an act of parliament of 1744
geotrichosis is a mycosis caused by geotrichum candidum the lungs are the primary organ affected but other systems can be involved
gephyrophobia is the anxiety disorder or specific phobia characterized by the fear of bridges as a result sufferers of gephyrophobia may avoid routes that will take them over bridges some possible explanations of gephyrophobia may be the fear of the structural integrity of the bridges itself or the fear that the bridge will collapse if they try to cross it dr michael liebowitz founder of the anxiety disorders clinic at the new york state psychiatric institute says it s not an isolated phobia but usually part of a larger constellation it s people who get panic attacks you get light headed dizzy your heart races you become afraid that you ll feel trapped the new york state thruway authority will lead gephyrophobiacs over the tappan zee bridge a driver can call the authority in advance and arrange for someone to drive the car over the bridge for them the authority performs the service about six times a year the maryland transportation authority offers a similar service for crossing the chesapeake bay bridge the mackinac bridge authority which oversees the mackinac bridge which connects michigan ’ s upper and lower peninsulas will drive one s car across its span for any needy gephyrophobiacs some thousand drivers take advantage of this free program each year the term gephyrophobia comes from greek γέφυρα gephura meaning bridge and φόβος phobos fear
geriatric trauma refers to a traumatic injury that occurs to an elderly person the three prevailing causes of traumatic death in the elderly are falls which account for 40 of traumatic death in this age group traffic collisions and burns
a germ cell tumor gct is a neoplasm derived from germ cells germ cell tumors can be cancerous or non cancerous tumors germ cells normally occur inside the gonads ovary and testis germ cell tumors that originate outside the gonads may be birth defects resulting from errors during development of the embryo
the letter monopoly german briefmonopol was a condition created after the german postgesetz law was changed in 2005 — 2007 to allow an exclusive license to the german post office deutsche post for the transport of letters and catalog deliveries of up to 50 grams from the previous 100 grams this limit only applied to a portion of the postal market in a service industry of some 1 000 providers but it created a monopoly the letter monopoly was often justified by the provision of universal service by the state but some german cities wanted it to be abolished
germinal matrix hemorrhage is a bleeding into the subependymal germinal matrix with or without subsequent rupture into the lateral ventricle
a germinoma is a type of germ cell tumor which is not differentiated upon examination it may be benign or malignant
germline mosaicism also called gonadal mosaicism is a type of genetic mosaicism where more than one set of genetic information is found specifically within the gamete cells somatic mosaicism a type of genetic mosaicism found in somatic cells and germline mosaicism can be present at the same time or individually depending on when the conditions occur when the mosaicism is only found in the gametes and not in any somatic cells it is referred to as pure germline mosaicism germline mosaicism can be caused either by a mutation that occurs after conception or by epigenetic regulation alterations to dna such as methylation that do not involve changes in the dna coding sequence a mutation in an allele acquired by a somatic cell early in it s development can be passed on to its daughter cells including those that later specialize to gametes it can also be caused by a sporadic mutation in a gamete cell if the germline mosaicism causing mutation occurs in the somatic cell it never results in pure germline mosaicism because it will be present in somatic cells as well
gerodermia osteodysplastica go also called geroderma osteodysplasticum and walt disney dwarfism is a rare autosomal recessive connective tissue disorder included in the spectrum of cutis laxa syndromes usage of the name walt disney dwarfism is attributed to the first known case of the disorder documented in a 1950 journal report in which the authors described five affected members from a swiss family as having the physical appearance of dwarves from a walt disney film the terms geroderma or gerodermia can be used interchangeably with osteodysplastica or osteodysplasticum with the term hereditaria sometimes appearing at the end
gerstmann syndrome is a neuropsychological disorder that is characterized by a constellation of symptoms that suggests the presence of a lesion in a particular area of the brain it should not be confused with gerstmann sträussler scheinker syndrome which is a transmissible spongiform encephalopathy destruction to the inferior parietal lobule of the dominant hemisphere results in gerstmann s syndrome it is named for josef gerstmann
gerstmann – sträussler – scheinker syndrome gss is a very rare usually familial fatal neurodegenerative disease that affects patients from 20 to 60 years in age though exclusively heritable this extremely rare disease is classified with the transmissible spongiform encephalopathies tse due to the causative role played by prnp the human prion protein the exact incidence of gss is unknown but is estimated to be between 1 and 10 per 100 million familial cases are associated with autosomal dominant inheritance gerstmann – sträussler – scheinker disease gss is an extremely rare neurogenetic brain disorder it is always inherited and is found in only a few families all over the world ninds ¶ 1 the trait is an autosomal dominant trait caused by a gene mutation it is also in a group of hereditary prion protein diseases or also known as tses many symptoms are associated with gss such as progressive ataxia pyramidal signs and even adult onset dementia they progress more as the disease progresses farlow et al nov 1989
gestaltzerfall german for shape decomposition refers to a type of visual agnosia and is psychological phenomenon where delays in recognition are observed when a complex shape is stared at for a while as the shape seems to decompose into its constituting parts with regards to kanji a study has shown that delays are most significant when the characters are of the same size when characters to recognize are of different sizes delays are observed only when they are of different patterns the phenomenon was first described and named by c faust in 1947 as a symptom of the bilateral region of the parieto occipital sulcus after a through and through bullet wound of this region afterwards when the concerned person stared at a truck for a while the truck seemed to decompose into its motor chassis driver cab and the person could only focus on one of these parts until he shortly closed his eyes or looked away which reset the shape to the complete truck again the characteristics of orthographic satiation as opposed to semantic satiation is that meaning remains intact it was suggested that this is different from semantic satiation and from stimulus familiarization effect because orthographic satiation occurs after the perceivers have access to the lexical meaning
gestational choriocarcinoma is a malignant trophoblastic tumour arising from any gestational event during pregnancy in the reproductive female women with gestational choriocarcinoma may present with abnormal vaginal bleeding persistent markedly elevated βhcg or a history of prior pregnancy most patients develop gestational choriocarcinoma shortly after gestational anomalies but pathology may occur after a long latency of years it may occur during pregnancy often it happens after a growth of some sort in the womb pregnancy tumor mole cyst
gestational diabetes also known as gestational diabetes mellitus gdm is when a woman without diabetes develops high blood sugar levels during pregnancy gestational diabetes generally results in few symptoms however it does increase the risk of pre eclampsia depression and requiring a caesarean section babies born to mothers with poorly treated gestational diabetes are at increased risk of being too large having low blood sugar after birth and jaundice if untreated it can also result in a stillbirth long term children are at higher risk of being overweight and developing type 2 diabetes gestational diabetes is caused by not enough insulin in the setting of insulin resistance risk factors include being overweight previously having gestational diabetes a family history of type 2 diabetes and having polycystic ovarian syndrome diagnosis is by blood tests for those at normal risk screening is recommended between 24 and 28 weeks gestation for those at high risk testing may occur at the first prenatal visit prevention is by maintaining a healthy weight and exercising before pregnancy gestational diabetes is a treated with a diabetic diet exercise and possibly insulin injections most women are able to manage their blood sugar with a diet and exercise blood sugar testing among those who are affected is often recommended four times a day breastfeeding is recommended as soon as possible after birth gestational diabetes affects 3 – 9 of pregnancies depending on the population studied it is especially common during the last third of pregnancy it affects 1 of those under the age of 20 and 13 of those over the age of 44 a number of ethnic groups including asians american indians indigenous australians and pacific islanders are at higher risk in 90 of people gestational diabetes will resolve after the baby is born women however are at an increased risk of developing type 2 diabetes
gestational hypertension or pregnancy induced hypertension pih is the development of new hypertension in a pregnant woman after 20 weeks gestation without the presence of protein in the urine or other signs of preeclampsia hypertension is defined as having a blood pressure greater than 140 90 mm hg
gestational pemphigoid or pemphigoid gestationis pg is a dermatosis of pregnancy being an autoimmune blistering skin disease that occurs during pregnancy typically in the second or third trimester and or immediately following pregnancy it was originally called herpes gestationis because of the blistering appearance although it is not associated with the herpes virus
gestational incidental thrombocytopenia is a condition that commonly affects pregnant women thrombocytopenia is defined as the drop in platelet count from the normal range of 150 000 – 400 000 μl to a count lower than 150 000 μl there is still ongoing research to determine the reason for the lowering of platelet count in women with a normal pregnancy some researchers speculate the cause to be dependent on dilution decreased production of platelets or an increased turnover event although women with normal pregnancy experience a low platelet count women experiencing a continuous drop in platelet will be diagnosed with thrombocytopenia and women with levels greater than 70 000 µl will be diagnosed with gestational thrombocytopenia thrombocytopenia affects approximately 7 10 of pregnant women and of the 7 10 within that population approximately 70 80 have gestational thrombocytopenia gestational thrombocytopenia is a disorder similar to immune thrombocytopenia itp and is difficult to differentiate between the two disorders therefore a medical history is conducted to because a diagnostic test is unavailable
gestational trophoblastic disease gtd is a term used for a group of pregnancy related tumours these tumours are rare and they appear when cells in the womb start to proliferate uncontrollably the cells that form gestational trophoblastic tumours are called trophoblasts and come from tissue that grows to form the placenta during pregnancy there are several different types of gtd hydatidiform moles are benign in most cases but sometimes may develop into invasive moles or in rare cases into choriocarcinoma which is likely to spread quickly but which is very sensitive to chemotherapy and has a very good prognosis gestational trophoblasts are of particular interest to cell biologists because like cancer these cells invade tissue the uterus but unlike cancer they sometimes know when to stop gtd can simulate pregnancy because the uterus may contain fetal tissue albeit abnormal this tissue may grow at the same rate as a normal pregnancy and produces chorionic gonadotropin a hormone which is measured to monitor fetal well being while gtd overwhelmingly affects women of child bearing age it may rarely occur in postmenopausal women
getopt is a c library function used to parse command line options it is also the name of a unix program for parsing command line arguments in shell scripts
the gewald reaction is an organic reaction involving the condensation of a ketone or aldehyde when r 2 h with a α cyanoester in the presence of elemental sulfur and base to give a poly substituted 2 amino thiophene the gewald reaction the reaction is named after the german chemist karl gewald born 1930
ghon s complex is a lesion seen in the lung that is caused by tuberculosis the lesions consist of a calcified focus of infection and an associated lymph node these lesions are particularly common in children and can retain viable bacteria so are sources of long term infection and may be involved in reactivation of the disease in later life in countries where cow milk infected with mycobacterium bovis has been eliminated due to culling of infected cows and pasteurization primary tuberculosis is usually caused by mycobacterium tuberculosis and almost always begins in the lungs typically the inhaled bacilli implant in the distal airspaces of the lower part of the upper lobe or the upper part of the lower lobe usually close to the pleura as sensitization develops a 1 to 1 5 cm area of gray white inflammation with consolidation emerges known as the ghon focus in most cases the center of this focus undergoes caseous necrosis tubercle bacilli either free or within phagocytes drain to the regional nodes which also often caseate this combination of parenchymal lung lesion and nodal involvement is referred to as the ghon complex during the first few weeks there is also lymphatic and hematogenous dissemination to other parts of the body in approximately 95 of cases development of cell mediated immunity controls the infection
a ghon focus is a primary lesion usually subpleural often in the mid to lower zones caused by mycobacterium bacilli tuberculosis developed in the lung of a nonimmune host usually a child it is named for anton ghon 1866 – 1936 an austrian pathologist it is a small area of granulomatous inflammation only detectable by chest x ray if it calcifies or grows substantially see tuberculosis radiology typically these will heal but in some cases especially in immunosuppressed patients it will progress to miliary tuberculosis so named due to the granulomas resembling millet seeds on a chest x ray the classical location for primary infection is surrounding the lobar fissures either in the upper part of the lower lobe or lower part of the upper lobe if the ghon focus also involves infection of adjacent lymphatics and hilar lymph nodes it is known as the ghon s complex or primary complex when a ghon s complex undergoes fibrosis and calcification it is called a ranke complex
ghosal hematodiaphyseal dysplasia is a metabolic disorder it is associated with diaphyseal dysplasia and refractory anemia it is associated with a deficiency of thromboxane a synthase which produces thromboxane a 2 it was characterized in 1988
gianotti – crosti syndrome english dʒəˈnɒti ˈkrɔːsti also known as infantile papular acrodermatitis papular acrodermatitis of childhood and papulovesicular acrolocated syndrome is a reaction of the skin to a viral infection hepatitis b virus and epstein – barr virus are the most frequently reported pathogens other incriminated viruses are hepatitis a virus hepatitis c virus cytomegalovirus coxsackievirus adenovirus enterovirus rotavirus rubella virus hiv and parainfluenza virus it is named for ferdinando gianotti and agostino crosti
giant cell arteritis gca also called temporal arteritis cranial arteritis or horton disease is an inflammatory disease of blood vessels most commonly involving large and medium arteries of the head predominantly the branches of the external carotid artery the most serious complication is occlusion of the ophthalmic artery which is a branch of the internal carotid it can create a medical emergency which can cause irreversible ischemia and blindness if not treated promptly gca is treated with glucocorticoids steroids which reduce the inflammation and prevent occlusion no other drugs are effective or contribute to the effect of glucocorticoids gca is a form of vasculitis it typically causes inflammation of the network of small vessels vasa vasorum that supplies the larger arteries gca affects arteries of the head and neck including the three arteries that branch out from the arch of the ascending aorta and their branches — the thoracic aorta the axillary arteries the vertebral arteries and further on in the head in the ophthalmic and external carotid arteries the temporal and occipital arteries it can cause occlusion of the arteries and ischemia gca is diagnosed with biopsy of the temporal artery while the clinical presentation patient characteristics and blood test markers of inflammation can raise suspicion only a temporal artery biopsy can give definite diagnosis some cases may not involve the temporal artery and distinguishing between a false negative and the absence of gca is difficult the terms giant cell arteritis and temporal arteritis are sometimes used interchangeably because of the frequent involvement of the temporal artery however it can involve other large vessels such as the aorta in giant cell aortitis giant cell arteritis of the temporal artery is referred to as temporal arteritis and is also known as cranial arteritis and horton s disease the name giant cell arteritis reflects the type of inflammatory cell involved as seen on a biopsy
giant cell carcinoma of the lung gccl is a rare histological form of large cell lung carcinoma a subtype of undifferentiated lung cancer traditionally classified within the non small cell lung carcinomas nsclc the characteristic feature of this highly lethal malignancy is the distinctive light microscopic appearance of its extremely large cells which are bizarre and highly pleomorphic and which often contain more than one huge misshapen pleomorphic nucleus syncytia which result from cell fusion although it is common in the lung cancer literature to refer to histologically mixed tumors containing significant numbers of malignant giant cells as giant cell carcinomas technically a diagnosis of giant cell carcinoma should be limited strictly to neoplasms containing only malignant giant cells i e pure giant cell carcinoma aside from the great heterogeneity seen in lung cancers especially those occurring among tobacco smokers the considerable variability in diagnostic and sampling techniques used in medical practice the high relative proportion of individuals with suspected gccl who do not undergo complete surgical resection and the near universal lack of complete sectioning and pathological examination of resected tumor specimens prevent high levels of quantitative accuracy
giant cell fibroma is a type of fibroma not associated with trauma or irritation it can occur at any age and on a mucous membrane surface the most common oral locations are on the gingiva of the mandible tongue and palate it is a localized reactive proliferation of fibrous connective tissue giant cell fibroma gcf is a benign non neoplastic lesion first described by weathers and callihan 1974 it occurs in the first three decades of life and predominates in females houston 1982 bakos 1992 clinically the gcf presents as an asymptomatic papillary and pedunculated lesion the most predominant location is the mandibular gingiva houston 1982 bakos 1992 histologically the gcf is distinctive consisting of fibrous connective tissue without inflammation and covered with stratified squamous hyperplastic epithelium the most characteristic histological feature is the presence of large spindle shaped and stellate shaped mononuclear cells and multinucleated cells these cells occur in a variety of lesions such as the fibrous papule of the nose ungual fibroma acral fibrokeratoma acral angiofibroma and desmoplastic fibroblastoma swan 1988 pitt et al 1993 karabela bouropoulou et al 1999 jang et al 1999 despite many studies the nature of the stellated multinucleate and mononuclear cell is not clear weathers and campbell 1974 regezi et al 1987 odell et al 1994 magnusson and rasmusson 1995
giant cell reticulohistiocytoma also known as solitary reticulohistiocytoma and solitary reticulohistiocytosis is a cutaneous condition characterized by a solitary skin lesion
giant cell tumor of the bone gctob is a relatively uncommon tumor of the bone it is characterized by the presence of multinucleated giant cells osteoclast like cells malignancy in giant cell tumor is uncommon and occurs in about 2 of all cases however if malignant degeneration does occur it is likely to metastasize to the lungs giant cell tumors are normally benign with unpredictable behavior it is a heterogeneous tumor composed of three different cell populations the giant cell tumour stromal cells gctsc constitute the neoplastic cells which are from an osteoblastic origin and are classified based on expression of osteoblast cell markers such as alkaline phosphatase and osteocalcin in contrast the mononuclear histiocytic cells mnhc and multinucleated giant cell mngc fractions are secondarily recruited and comprise the non neoplastic cell population they are derived from an osteoclast monocyte lineage determined primarily by expression of cd 68 a marker for monocytic precursor cells in most patients the tumors are slow to develop but may recur locally in as many as 50 of cases
giant cell tumor of the tendon sheath also known as giant cell synovioma and localized nodular tenosynovitis is a firm lesion measuring 1 to 3 cm in diameter and is most commonly attached to the tendons of the fingers hands and wrists with a predilection for the flexor surfaces giant cell tumor of tendon sheaths most often affect the wrist and fingers of males and females from the ages of 20 50 these tumors are typically painless and can cause cortical erosion surgery to remove the tumor is a common treatment though the tumors tend to recur
giant axonal neuropathy is a rare autosomal recessive neurological disorder that causes disorganization of neurofilaments neurofilaments form a structural framework that helps to define the shape and size of neurons and are essential for normal nerve function
giant axonal neuropathy with curly hair is an autosomal recessive condition due to mutations in gigaxonin
giant cell lichenoid dermatitis is a cutaneous condition usually drug associated entity characterized by a lichenoid dermatitis with a granulomatous infiltrate composed of histiocytes and multinucleated giant cells
giant condyloma acuminatum also known as a buschke – löwenstein tumor and giant condyloma of buschke – löwenstein tumor is a rare cutaneous condition characterized by an aggressive wart like growth that is a verrucous carcinoma it is attributed to human papillomavirus
giant magnetoresistance gmr is a quantum mechanical magnetoresistance effect observed in thin film structures composed of alternating ferromagnetic and non magnetic conductive layers the 2007 nobel prize in physics was awarded to albert fert and peter grünberg for the discovery of gmr the effect is observed as a significant change in the electrical resistance depending on whether the magnetization of adjacent ferromagnetic layers are in a parallel or an antiparallel alignment the overall resistance is relatively low for parallel alignment and relatively high for antiparallel alignment the magnetization direction can be controlled for example by applying an external magnetic field the effect is based on the dependence of electron scattering on the spin orientation the main application of gmr is magnetic field sensors which are used to read data in hard disk drives biosensors microelectromechanical systems mems and other devices gmr multilayer structures are also used in magnetoresistive random access memory mram as cells that store one bit of information in literature the term giant magnetoresistance is sometimes confused with colossal magnetoresistance of ferromagnetic and antiferromagnetic semiconductors which is not related to the multilayer structure
giant platelet disorders are rare disorders featuring abnormally large platelets thrombocytopenia and a tendency to bleeding giant platelets cannot stick adequately to an injured blood vessel walls resulting in abnormal bleeding when injured giant platelet disorder occurs for inherited diseases like bernard soulier syndrome gray platelet syndrome and may hegglin anomaly
a giant solitary trichoepithelioma is a cutaneous condition characterized by a skin lesion that may be up to several centimeters in diameter
giardiasis popularly known as beaver fever is a zoonotic parasitic disease caused by the flagellate protozoan giardia lamblia also sometimes called giardia intestinalis and giardia duodenalis the giardia organism inhabits the digestive tract of a wide variety of domestic and wild animal species as well as humans it is one of the most common pathogenic parasitic infections in humans worldwide in 2013 there were about 280 million people worldwide with symptomatic giardiasis
in the dungeons dragons fantasy role playing game a gibbering mouther is a horrific aberration which feeds on the bodily fluids and sanity of its victims it resembles a writhing mass of grey flesh covered with dozens of randomly placed eyes and mouths of different sizes and shapes
the gibibit is a multiple of the bit a unit of information prefixed by the standards based multiplier gibi symbol gi a binary prefix meaning 230 the unit symbol of the gibibit is gibit 1 gibibit 230 bits 1073741824 bits 1 024 mebibits the gibibit is closely related to the gigabit the corresponding unit using the metric prefix giga which is 109 bits
the gibibyte is a multiple of the unit byte for digital information the binary prefix gibi means 230 therefore one gibibyte is equal to 1073741824 bytes 1024 mebibytes the unit symbol for the gibibyte is gib it is a member of the set of units with binary prefixes defined by the international electrotechnical commission iec the gibibyte is very closely related to the gigabyte gb the gb is defined by the iec as 109 bytes 1000000000 bytes 1 gib ≈ 1 074 gb 1024 gibibytes are equal to one tebibyte in the context of computer memory gigabyte and gb are customarily used to mean 10243 230 bytes although not in the context of data transmission and not necessarily in the context of hard drive size the word gibibyte was coined in 1998 binary prefixes are increasingly used in technical literature and open source software and are a component of the international system of quantities
the gigabit is a multiple of the unit bit for digital information or computer storage the prefix giga symbol g is defined in the international system of units si as a multiplier of 109 1 billion short scale and therefore 1 gigabit 109 bits 1000000000 bits the gigabit has the unit symbol gbit or gb using the common byte size of 8 bits 1 gbit is equal to 125 megabytes mb or approximately 119 mebibytes mib the gigabit is closely related to the gibibit a unit multiple derived from the binary prefix gibi symbol gi of the same order of magnitude which is equal to 230 bits 1073741824 bits or approximately 7 larger than the gigabit
the gigabyte ˈɡɪɡəbaɪt gig ə byt or ˈdʒɪɡəbaɪt is a multiple of the unit byte for digital information the prefix giga means 109 in the international system of units si therefore one gigabyte is 1000000000 bytes the unit symbol for the gigabyte is gb this definition is used in all contexts of science engineering business and many areas of computing including hard drive solid state drive and tape capacities as well as data transmission speeds however the term is also used in some fields of computer science and information technology to denote 1073741824 10243 or 230 bytes particularly for sizes of ram the use of gigabyte is thus ambiguous for semiconductor ram the gigabyte denotes 1073741824 bytes for hard drive capacities as described and marketed by the drive manufacturers the gigabyte denotes 1000000000 bytes but when a 500 gb drive s capacity is displayed by for example microsoft windows it is reported as 465 gb where gb then means 1073741824 bytes to address this ambiguity the binary prefixes are standardized in the international system of quantities each binary prefix denoting an integer power of 1024 with these prefixes a memory module that is labeled as having the size 1 gb is designated as 1 gib one gibibyte
gigantism also known as giantism from greek γίγας gigas giant plural γίγαντες gigantes is a condition characterized by excessive growth and height significantly above average in humans this condition is caused by over production of growth hormone in childhood resulting in people between 7 feet 2 13 m and 9 feet 2 75 m in height
the phenomenon is important in the biology of ectothermic megafauna such as large turtles and aquatic reptiles like ichthyosaurs and mosasaurs gigantotherms though almost always ectothermic generally have a body temperature similar to that of endotherms it has been suggested that the larger dinosaurs would have been gigantothermic rendering them virtually homeothermic
gilbert s syndrome gs is a common genetic liver disorder found in 3 12 of the population it produces elevated levels of unconjugated bilirubin in the bloodstream hyperbilirubinemia but this normally has no serious consequences although mild jaundice may appear under conditions of exertion or stress the cause of this hyperbilirubinemia is the reduced activity of the enzyme glucuronyltransferase which conjugates bilirubin and a few other lipophilic molecules conjugation renders the bilirubin water soluble after which it is excreted in bile into the duodenum there are a number of variants of the gene for the enzyme so the genetic basis of the condition is complex
gillespie syndrome also called aniridia cerebellar ataxia and mental deficiency is a rare genetic disorder the disorder is characterized by partial aniridia meaning that part of the iris is missing ataxia motor and coordination problems and in most cases intellectual disability it is heterogeneous inherited in either an autosomal dominant or autosomal recessive manner gillespie syndrome was first described by american ophthalmologist fredrick gillespie in 1965
gillette syndrome is the social disruption that can occur in a community due to rapid population growth such disruptions usually include increased crime degraded mental health weakened social and community bonds abnormally high costs of living and other social problems gillette syndrome is most relevant to boomtowns that are growing rapidly due to nearby natural resource extraction such as coal mining or natural gas drilling psychologist eldean kohrs coined the term gillette syndrome in an attempt to describe the social impacts of rapid coal mining development on the boomtown of gillette wyoming
gimbal lock is the loss of one degree of freedom in a three dimensional three gimbal mechanism that occurs when the axes of two of the three gimbals are driven into a parallel configuration locking the system into rotation in a degenerate two dimensional space the word lock is misleading no gimbal is restrained all three gimbals can still rotate freely about their respective axes of suspension nevertheless because of the parallel orientation of two of the gimbals axes there is no gimbal available to accommodate rotation along one axis
the gingival cyst of the adult is a cyst of the odontogenic epithelium which arises from the rest cells of the dental lamina it is most common in the mandible near the canines and premolars middle aged adults are more likely to be affected it appears as a swelling on attached gingiva or interdental papilla gingival cyst of the adult is the soft tissue counterpart of the developmental lateral periodontal cyst
the gingival cyst of the newborn is a cyst that arises from the rest cells of the dental lamina it usually presents as a white papule 1 2 mm in diameter on the maxillary upper alveolar ridge of newborns no treatment is necessary
a gingival disease is a disorder primarily affecting the gingiva an example is gingivitis
gingival enlargement also termed gingival overgrowth hypertrophic gingivitis gingival hyperplasia or gingival hypertrophy and sometimes abbreviated to go is an increase in the size of the gingiva gums it is a common feature of gingival disease gingival enlargement can be caused by a number of factors including inflammatory conditions and the side effects of certain medications the treatment is based on the cause a closely related term is epulis denoting a localized tumor i e lump on the gingiva
gingival fibroma is a cutaneous condition that may be observed with another condition tuberous sclerosis
gingival fibromatosis with hypertrichosis is a cutaneous condition characterized by dark terminal hairs on the peripheral face central back and extremities it is a rasopathy
gingivitis inflammation of the gum tissue is a non destructive disease that occurs around the teeth the most common form of gingivitis and the most common form of periodontal disease overall is in response to bacterial biofilms also called plaque that is attached to tooth surfaces termed plaque induced gingivitis while some cases of gingivitis never progress to periodontitis data indicate that periodontitis is always preceded by gingivitis gingivitis is reversible with good oral hygiene however in the absence of treatment or if not controlled gingivitis can progress to periodontitis where the inflammation results in tissue destruction and alveolar bone resorption which can ultimately lead to tooth loss
gitelman syndrome is an autosomal recessive kidney disorder characterized by hypokalemic metabolic alkalosis with hypocalciuria and hypomagnesemia it is caused by loss of function mutations of the thiazide sensitive sodium chloride symporter also known as ncc ncct or tsc located in the distal convoluted tubule gitelman syndrome was formerly considered a subset of bartter syndrome until the distinct genetic and molecular bases of these disorders were identified bartter syndrome is also an autosomal recessive hypokalemic metabolic alkalosis but it derives from a mutation to the nkcc 2 found in the thick ascending limb of the loop of henle
the glabella in humans is the skin between the eyebrows and above the nose it also refers to the underlying bone which is slightly depressed and joins the two superciliary ridges it is a cephalometric landmark that is just superior to the nasion
a glacial stream is a channelized accumulation of liquid water which flow in a channel formed by a glacier depending on where they flow they can be classified into supraglacial englacial and subglacial streams
sediments deposited into lakes that have come from glaciers are called glaciolacustrine deposits these lakes include ice margin lakes or other types formed from glacial erosion or deposition sediments in the bedload and suspended load are carried into lakes and deposited the bedload is deposited at the lake margin while the suspended load is deposited all over the lake bed
glanders from middle english glaundres or old french glandres both meaning glands latin malleus german rotz also known as equinia farcy and malleus is an infectious disease that occurs primarily in horses mules and donkeys it can be contracted by other animals such as dogs cats goats and humans it is caused by infection with the bacterium burkholderia mallei usually by ingestion of contaminated feed or water signs of glanders include the formation of nodular lesions in the lungs and ulceration of the mucous membranes in the upper respiratory tract the acute form results in coughing fever and the release of an infectious nasal discharge followed by septicaemia and death within days in the chronic form nasal and subcutaneous nodules develop eventually ulcerating death can occur within months while survivors act as carriers glanders is endemic in africa asia the middle east and central and south america it has been eradicated from north america australia and most of europe through surveillance and destruction of affected animals and import restrictions b mallei is able to infect humans so is classed as a zoonotic agent transmission occurs by direct contact with infected animals and entry is through skin abrasions nasal and oral mucosal surfaces or by inhalation the mallein test is a sensitive and specific clinical test for glanders mallein atcvet code qi 05 ar 01 who a protein fraction of the glanders organism b mallei is injected intradermopalpebrally or given by eye drop in infected animals the eyelid swells markedly in 1 to 2 days glanders has not been reported in the united states since 1945 except in 2000 when an american lab researcher suffered from accidental exposure it is a notifiable disease in the uk although it has not been reported there since 1928
the glandular odontogenic cyst is a rare odontogenic cyst in 85 of cases it is found in the mandible especially in anterior areas it is more common in adults in their fifth and sixth decades on radiographs it can appear as a unilocular or multilocular radiolucency dark area since the glandular odontogenic cyst can range in size treatment can be as simple as enucleation and curettage to en bloc resection of the affected jaw
in glandular rosacea men with thick sebaceous skin predominate a disease in which the papules are edematous the pustules often 0 5 to 1 0 cm in size with nodulocystic lesions often present
glanzmann s thrombasthenia is an abnormality of the platelets it is an extremely rare coagulopathy bleeding disorder due to a blood abnormality in which the platelets contain defective or low levels of glycoprotein iib iiia gpiib iiia which is a receptor for fibrinogen as a result no fibrinogen bridging of platelets to other platelets can occur and the bleeding time is significantly prolonged
glare is difficulty seeing in the presence of bright light such as direct or reflected sunlight or artificial light such as car headlamps at night because of this some cars include mirrors with automatic anti glare functions glare is caused by a significant ratio of luminance between the task that which is being looked at and the glare source factors such as the angle between the task and the glare source and eye adaptation have significant impacts on the experience of glare
the glaser coupling is a type of coupling reaction it is by far the oldest acetylenic coupling and is based on cuprous salts like copper i chloride or copper i bromide and an additional oxidant like oxygen the base in its original scope is ammonia the solvent is water or an alcohol the reaction was first reported by carl andreas glaser in 1869
the glass delusion is an external manifestation of a psychiatric disorder recorded in europe mainly in the late middle ages and early modern period 15 th to 17 th centuries people feared that they were made of glass “ and therefore likely to shatter into pieces ” one famous early sufferer was king charles vi of france who refused to allow people to touch him and wore reinforced clothing to protect himself from accidental “ shattering ”
the glass house effect or ghe is the resulting phenomenon brought on by an awareness that one is subject to ubiquitous surveillance in corporate environments the transparency is considered a good idea as it is believed this discourages corporate crime and other misfeasance the glass house effect can induce an overwhelming sense of hopelessness brought on those subject to such uncontrolled observation in such circumstances solitude is conspicuously absent and privacy is considered a thoughtcrime the messages conveyed to the subject in such an environment usually involve some variation on the notion of catch 22 such as 1 there is no place to hide nor should you want to 2 any exhibited avoidance behavior is considered a threat and an invitation for additional scrutiny
glassy cell carcinoma of the cervix also glassy cell carcinoma is a rare aggressive malignant tumour of the uterine cervix the tumour gets its name from its microscopic appearance its cytoplasm has a glass like appearance
glaucoma is a group of eye diseases which result in damage to the optic nerve and vision loss the most common type is open angle glaucoma with less common types including closed angle glaucoma and normal tension glaucoma open angle glaucoma develops slowly over time and there is no pain side vision may begin to decrease followed by central vision resulting in blindness if not treated closed angle glaucoma can present gradually or suddenly the sudden presentation may involve severe eye pain blurred vision mid dilated pupil redness of the eye and nausea vision loss from glaucoma once it has occurred is permanent risk factors for glaucoma include increased pressure in the eye a family history of the condition migraines high blood pressure and obesity for eye pressures a value of greater than 21 mmhg or 2 8 kpa is often used with higher pressures leading to a greater risk however some may have high eye pressure for years and never develop damage conversely optic nerve damage may occur with normal pressure known as normal tension glaucoma the mechanism of open angle glaucoma is believed to be slow exit of aqueous humor through the trabecular meshwork while in closed angle glaucoma the iris blocks the trabecular meshwork diagnosis is by a dilated eye examination often the optic nerve shows an abnormal amount of cupping if treated early it is possible to slow or stop the progression of disease with medication laser treatment or surgery the goal of these treatments is to decrease eye pressure a number of different classes of glaucoma medication are available laser treatments may be effective in both open angle and closed angle glaucoma a number of types of glaucoma surgeries may be used in people who do not respond sufficiently to other measures treatment of closed angle glaucoma is a medical emergency about eleven to sixty seven million people have glaucoma globally the disease affects about two million people in the united states it occurs more commonly among older people closed angle glaucoma is more common in women glaucoma has been called the silent thief of sight because the loss of vision usually occurs slowly over a long period of time worldwide glaucoma is the second leading cause of blindness after cataracts the word glaucoma is from ancient greek glaukos which means blue green or gray in english the word was used as early as 1587 but did not become commonly used until after 1850 when the development of the ophthalmoscope allowed people to see the optic nerve damage
gleich s syndrome or episodic angioedema with eosinophilia is a rare disease in which the body swells up episodically angioedema associated with raised antibodies of the igm type and increased numbers of eosinophil granulocytes a type of white blood cells in the blood eosinophilia it was first described in 1984 its cause is unknown but it is unrelated to capillary leak syndrome which may cause similar swelling episodes and eosinophilia myalgia syndrome which features eosinophilia but alternative symptoms moreover it is not a form of hypereosinophilic syndrome as there is no evidence that it leads to organ damage some studies have shown that edema attacks are associated with degranulation release of enzymes and mediators from eosinophils and others have demonstrated antibodies against endothelium cells lining blood vessels in the condition gleich syndrome has a good prognosis attack severity may improve with steroid treatment
the glider is a pattern that travels across the board in conway s game of life it was first discovered by richard k guy in 1970 while john conway s group was attempting to track the evolution of the r pentomino gliders are the smallest spaceships and they travel diagonally at a speed of c 4 the glider is often produced from randomly generated starting configurations john conway has remarked that he wishes he hadn t called it the glider the game was developed before computers and after seeing it animated he feels the glider looks more like an ant walking across the plane
glioblastoma multiforme gbm also known as glioblastoma and grade iv astrocytoma is the most common and most aggressive cancer that begins within the brain signs and symptoms are initially non specific they may include headaches personality changes nausea and symptoms similar to those of a stroke worsening of symptoms is often rapid this can progress to unconsciousness the cause of most cases is unclear uncommon risk factors include genetic disorders such as neurofibromatosis and li fraumeni syndrome and previous radiation therapy glioblastomas represent 15 of brain tumors they can either start from normal brain cells or develop from an already existing low grade astrocytoma the diagnosis is typically made by a combination of ct scan mri scan and tissue biopsy there is no clear way to prevent the disease typically treatment involves surgery after which chemotherapy and radiation therapy are used the medication temozolomide is frequently used as part of chemotherapy high dose steroids may be used to help reduce swelling and decrease symptoms it is unclear whether trying to remove all or simply most of the cancer is better despite maximum treatment the cancer usually recurs the most common length of survival following diagnosis is 12 to 15 months with less than 3 to 5 of people surviving longer than five years without treatment survival is typically 3 months about 3 per 100 000 people develop the disease a year it most often begins around 64 years of age and occurs more commonly in males than females immunotherapy is being studied in glioblastoma with promising results
a glioma is a type of tumor that starts in the brain or spine it is called a glioma because it arises from glial cells the most common site of gliomas is the brain gliomas make up about 30 of all brain and central nervous system tumors and 80 of all malignant brain tumors
gliomatosis cerebri infiltrative diffuse astrocytosis is a rare primary brain tumor it is commonly characterized by diffuse infiltration of the brain with neoplastic glial cells that affect various areas of the cerebral lobes these malignancies consist of infiltrative threads that spread quickly and deeply into the surrounding brain tissue or into multiple parts of the brain simultaneously making them very difficult to remove with surgery or treat with radiation gliomatosis cerebi behaves like a malignant tumor that is very similar to glioblastoma while gliomatosis cerebri can occur at any age it is generally found in the third and fourth decades of life
gliosarcoma is a rare type of glioma a cancer of the brain that comes from glial or supportive brain cells as opposed to the neural brain cells gliosarcoma is a malignant cancer and is defined as a glioblastoma consisting of gliomatous and sarcomatous components it is estimated that approximately 2 1 of all glioblastomas are gliosarcomas although most gliomas rarely show metastases outside the cerebrum gliosarcomas have a propensity to do so most commonly spreading through the blood to the lungs and also liver and lymph nodes gliosarcomas have an epidemiology similar to that of glioblastomas with the average age of onset being 54 years and males being affected twice as often as females they are most commonly present in the temporal lobe
a glitch is a sudden increase up to 1 part in 106 in the rotational frequency of a rotation powered pulsar which usually decreases steadily due to braking provided by the emission of radiation and high energy particles it is unknown whether they are related to the timing noise which all pulsars exhibit following a glitch is a period of gradual recovery where the observed periodicity slows to a period close to that observed before the glitch these gradual recovery periods have been observed to last from days to years currently only multiple glitches of the crab and vela pulsars have been observed and studied extensively
the general signs and or symptoms of global aphasia include the inability to comprehend speech the inability to form speech and the inability to repeat the speech one has heard also reading and writing are very difficult for individuals with global aphasia global aphasia can be more severe in some patients than others while one patient may not be able to speak at all another patient may be able to make a few small utterances it is most common for the onset of global aphasia to occur after a stroke
global labor arbitrage is an economic phenomenon where as a result of the removal of or disintegration of barriers to international trade jobs move to nations where labor and the cost of doing business such as environmental regulations is inexpensive and or impoverished labor moves to nations with higher paying jobs two common barriers to international trade are tariffs politically imposed and the costs of transporting goods across oceans with the advent of the internet the decrease of the costs of telecommunications and the possibility of near instantaneous document transfer the barriers to the trade of intellectual work product which is essentially any kind of work that can be performed on a computer such as computer programming or that makes use of a college education have been greatly reduced often a prosperous nation such as the united states will remove its barriers to international trade integrating its labor market with those of nations with a lower cost of labor such as india china and mexico resulting in a shifting of jobs from the prosperous nation to the developing one the end result is an increase in the supply of labor relative to the demand for labor which means a decrease in costs
in mathematical physics global hyperbolicity is a certain condition on the causal structure of a spacetime manifold that is a lorentzian manifold this is relevant to einstein s theory of general relativity and potentially to other metric gravitational theories
the globe effect sometimes called the rolling ball effect or the spinning globe effect is an optical phenomenon that occurs with visual optical instruments in particular binoculars and telescopes that are designed to be free of distortion when these instruments are panned the moving image appears to roll over a curved convex surface in 1949 horst koehler at zeiss jena suggested adding some pincushion distortion to the optical design to eliminate the globe effect august sonnefeld conducted experiments with volunteers which supported the claim that a supplementary distortion could improve the imaging of visual optical instruments since that time most binocular manufacturers have followed zeiss s example and added pincushion distortion to their optical design the origin of the globe effect initially remained unclear after its discovery in the first half of the past century koehler speculated about an unnatural perspective generated by the binocular while panning over a three dimensional scenery thereby ignoring the fact that the globe effect was observable at the night sky as well where perspective distortions were absent recently the globe effect has been linked to the peculiar properties of human visual perception which adds a certain amount of barrel distortion to the visual field the amount of barrel distortion is subject to individual differences which explains the fact that the perceived intensity of the globe effect varies significantly between different observers an alternative approach for explaining the globe effect comes from the technical journalist and optics specialist walter e schön he states that the observed effect is in fact not that of a rolling globe but that of a vertically rotating cylinder the globe shape of the illusion seen by most observers is only because the field of view through the optical device is circular this illusion of a rotating cylinder during panning is caused by the horizontal movement of the image being due to the angular magnification of the device faster and more uniform with less parallax compared to the naked eye and also not corresponding to the felt rotational speed of the observer s head when the brain tries to integrate these conflicting signals it creates the perception that the image is moving slower at the left and right edges than in the middle giving the illusion of a rotating cylinder
globe rupture is an ophthalmologic condition when the integrity of the outer membranes of the eye are disrupted by blunt or penetrating trauma usually resulting from a full thickness injury to the cornea or sclera it may also result from damage caused by chemicals such as strong acids hydrochloric acid sulfuric acid hydrofluoric acid etc or industrial chemicals such as lewisite during a globe rupture the outer membranes of the eye are completely or partially compromised and the vitreous and or aqueous humour drain through the site of the rupture causing the eye to deflate if not treated swiftly destruction of the affected eye usually results in many cases globe ruptures are untreatable without enucleating the affected eye socket and replacing the eye with an ocular prosthesis
the globulomaxillary cyst is a cyst that appears between a maxillary lateral incisor and the adjacent canine it exhibits as an inverted pear shaped radiolucency on radiographs or x ray films the globulomaxillary cyst often causes the roots of adjacent teeth to diverge this cyst should not be confused with a nasopalatine cyst the developmental origin has been disputed today most literature agree based on overwhelming evidence that the cyst is predominantly of tooth origin odontogenic demonstrating findings consistent with periapical cysts odontogenic keratocysts or lateral periodontal cysts
globus pharyngis also known as globus sensation globus or somewhat outdatedly globus hystericus commonly referred to as having a lump in one s throat is the persistent sensation of having phlegm a pill or some other sort of obstruction in the throat when there is none swallowing can be performed normally so it is not a true case of dysphagia but it can become quite irritating one may also feel mild chest pain or even severe pain with a clicking sensation when swallowing
glomangiosarcoma is a low grade tumor of the soft tissue they rarely metastasize but metastases are possible it is also known as malignant glomus tumor positive staining for vimentin has been reported
glomerulocystic kidney disease gckd is a cystic disorder of the kidneys gckd involves cystic dilation of bowman s capsule it can occur with or without congenital abnormality
glomeruloid hemangioma is a distinctive vascular neoplasm first described in 1990 when found to be associated with crow fukase syndrome and castleman s disease
glomerulonephritis gn also known as glomerular nephritis is a term used to refer to several kidney diseases usually affecting both kidneys many of the diseases are characterised by inflammation either of the glomeruli or of the small blood vessels in the kidneys hence the name but not all diseases necessarily have an inflammatory component as it is not strictly a single disease its presentation depends on the specific disease entity it may present with isolated hematuria and or proteinuria blood or protein in the urine or as a nephrotic syndrome a nephritic syndrome acute kidney injury or chronic kidney disease they are categorized into several different pathological patterns which are broadly grouped into non proliferative or proliferative types diagnosing the pattern of gn is important because the outcome and treatment differs in different types primary causes are intrinsic to the kidney secondary causes are associated with certain infections bacterial viral or parasitic pathogens drugs systemic disorders sle vasculitis or diabetes
glomerulonephrosis is a non inflammatory disease of the kidney nephrosis presenting primarily in the glomerulus a glomerulopathy it can be contrasted to glomerulonephritis which implies inflammation it can be caused by diethylnitrosamine
a glomus tumor also known as a solitary glomus tumor solid glomus tumor or glomangioma is a rare benign neoplasm arising from the glomus body and mainly found under the nail on the fingertip or in the foot they account for less than 2 of all soft tissue tumors glomus tumors were first described by hoyer in 1877 while the first complete clinical description was given by masson in 1924 histologically glomus tumors are made up of an afferent arteriole anastomotic vessel and collecting venule glomus tumors are modified smooth muscle cells that control the thermoregulatory function of dermal glomus bodies as stated above these lesions should not be confused with paragangliomas which were formerly also called glomus tumors in now antiquated clinical usage glomus tumors do not arise from glomus cells but paragangliomas do familial glomangiomas have been associated with a variety of deletions in the glmn glomulin gene and are inherited in an autosomal dominant manner with incomplete penetrance
a glory is an optical phenomenon that resembles an iconic saint s halo about the shadow of the observer s head caused by light of the sun or more rarely the moon interacting with the tiny water droplets that make up mist or clouds the glory consists of one or more concentric successively dimmer rings each of which is red on the outside and bluish towards the centre due to its appearance the phenomenon is sometimes mistaken for a circular rainbow but the latter has a much larger diameter and is caused by different physical processes the cause of the glory remains a matter of scholarly debate
glossitis can mean soreness of the tongue or more usually inflammation with depapillation of the dorsal surface of the tongue loss of the lingual papillae leaving a smooth and erythematous reddened surface sometimes specifically termed atrophic glossitis in a wider sense glossitis can mean inflammation of the tongue generally glossitis is often caused by nutritional deficiencies and may be painless or cause discomfort glossitis usually responds well to treatment if the cause is identified and corrected tongue soreness caused by glossitis is differentiated from burning mouth syndrome where there is no identifiable change in the appearance of the tongue and there are no identifiable causes
glossoptosis is a medical condition and abnormality which refers to the downward displacement or retraction of the tongue it may cause non fusion of hard palate causing cleft palate it is one of the features of pierre robin sequence and down syndrome
in operations research the glove problem also known as the condom problem is an optimization problem used as an example that the cheapest capital cost often leads to dramatic increase in operational time but that the shortest operational time need not be given by the most expensive capital cost
a glucagonoma is a rare tumor of the alpha cells of the pancreas that results in the overproduction of the hormone glucagon alpha cell tumors are commonly associated with glucagonoma syndrome though similar symptoms are present in cases of pseudoglucagonoma syndrome in the absence of a glucagon secreting tumor
glucocorticoid remediable aldosteronism gra also describable as aldosterone synthase hyperactivity is an autosomal dominant disorder in which the increase in aldosterone secretion produced by acth is no longer transient it is a cause of primary hyperaldosteronism
glucose 6 phosphate dehydrogenase deficiency g 6 pd deficiency also known as favism after the fava bean is an x linked recessive inborn error of metabolism that predisposes to hemolysis spontaneous destruction of red blood cells and resultant jaundice in response to a number of triggers such as certain foods illness or medication it is particularly common in people of mediterranean and african origin the condition is characterized by abnormally low levels of glucose 6 phosphate dehydrogenase an enzyme involved in the pentose phosphate pathway that is especially important in the red blood cell g 6 pd deficiency is the most common human enzyme defect there is no specific treatment other than avoiding known triggers in the united states no genetic screening of prospective parents is recommended as the symptoms only show in part of the carriers and when that is the case they can be prevented or controlled and as a result the disease generally has no impact on the lifespan of those affected however globally g 6 pd deficiency has resulted in 4 100 deaths in 2013 and 3 400 deaths in 1990 carriers of the g 6 pd allele appear to be protected to some extent against malaria and in some cases affected males have shown complete immunity to the disease this accounts for the persistence of the allele in certain populations in that it confers a selective advantage
glucose galactose malabsorption is a condition in which the cells lining the intestine cannot take in the sugars glucose and galactose which prevents proper digestion of these molecules and larger molecules made from them glucose and galactose are called simple sugars or monosaccharides sucrose and lactose are called disaccharides because they are made from two simple sugars and are broken down into these simple sugars during digestion sucrose is broken down into glucose and another simple sugar called fructose and lactose is broken down into glucose and galactose as a result lactose sucrose and other compounds made from carbohydrates cannot be digested by individuals with glucose galactose malabsorption
glutaric acidemia type 2 is an autosomal recessive metabolic disorder that is characterised by defects in the ability of the body to use proteins and fats for energy incompletely processed proteins and fats can build up leading to a dangerous chemical imbalance called acidosis
glutaric acidemia type 1 or glutaric aciduria ga 1 or gat 1 is an inherited disorder in which the body is unable to break down completely the amino acids lysine hydroxylysine and tryptophan excessive levels of their intermediate breakdown products glutaric acid glutaryl coa 3 hydroxyglutaric acid glutaconic acid can accumulate and cause damage to the brain and also other organs but particularly the basal ganglia which are regions that help regulate movement ga 1 causes secondary carnitine deficiency as glutaric acid like other organic acids is detoxified by carnitine mental retardation may also occur
glutathione synthetase deficiency is a rare autosomal recessive metabolic disorder that prevents the production of glutathione glutathione helps prevent damage to cells by neutralizing harmful molecules generated during energy production glutathione also plays a role in processing medications and cancer causing compounds carcinogens and building dna proteins and other important cellular components
glutathionuria is the presence of glutathione in the urine and is a rare inborn error of metabolism the condition has been identified in five patients
the glycemic response to a food or meal is the effect that food or meal has on blood sugar glucose levels after consumption it is normal for blood glucose and insulin levels to rise after eating and then return again to fasting levels over a short period of time this is particularly so after consumption of meals rich in certain carbohydrates glycemic management refers to the selection of foods to manage your blood sugar levels several tools have been developed to help quantify and communicate the effect of food on glycemic response these include glycemic index gi glycemic load gl and glycemic glucose equivalents gge a comparative glycemic response can also be determined which compares the impact on blood glucose of one food to another based upon their total carbohydrate or total quantity in 1981 the idea of classifying carbohydrates according to their glycemic index was first published since then many studies have been undertaken to determine the impact of altering the blood glucose raising potential glycemic challenge of the diet on a wide range of short and long term health outcomes however evaluating the impact of a single dietary change on health is notoriously complex and opinions on the relevance of gi gl and gge have been divided there are many different ways of lowering glycemic response gi or gl not all of which have the same effects on health ilsi europe published a monograph in november 2011 titled food glycaemic response and health which concluded that it is becoming evident that modifying the glycemic response of the diet should not be seen as a stand alone strategy but rather as an element of an overall balanced diet and lifestyle a low glycemic food will release glucose more slowly and steadily which leads to lower postprandial after meal blood glucose readings a high glycemic food causes a more rapid rise in blood glucose levels after meals high glycemic foods are ideal for energy recovery after exercise or for a person experiencing hypoglycemia the glycemic effect of foods depends on a number of factors such as the type of starch amylose versus amylopectin physical entrapment of the starch molecules within the food fat and protein content of the food and organic acids or their salts in the meal — adding vinegar for example will lower the glcyemic response the presence of fat or soluble dietary fiber can slow the gastric emptying rate thus lowering the glycemic response in general foods with higher amounts of fiber and or resistant starch have a lower glycemic response while adding fat or protein will lower the glycemic response to a meal the relative differences remain that is with or without additions there is still a higher blood glucose curve after a high glycemic white bread than after a low gycemic bread such as pumpernickel unrefined wild plant foods like those available to contemporary foragers typically exhibit low glycemic indices
glycerol kinase deficiency gkd is an x linked recessive enzyme defect that is heterozygous in nature three clinically distinct forms of this deficiency have been proposed namely infantile juvenile and adult national institutes of health and its office of rare diseases research ordr branch classifies gkd as a rare disease known to affect less than 200 000 individuals in the united states the responsible gene lies in a region containing genes in which deletions can cause duchenne muscular dystrophy and adrenal hypoplasia congenita combinations of these three genetic defects including gkd are addressed medically as complex gkd
glycine encephalopathy also known as non ketotic hyperglycinemia or nkh is a rare autosomal recessive disorder of glycine metabolism after phenylketonuria glycine encephalopathy is the second most common disorder of amino acid metabolism the disease is caused by defects in the glycine cleavage system an enzyme responsible for glycine catabolism there are several forms of the disease with varying severity of symptoms and time of onset the symptoms are exclusively neurological in nature and clinically this disorder is characterized by abnormally high levels of the amino acid glycine in bodily fluids and tissues especially the cerebral spinal fluid glycine encephalopathy is sometimes referred to as nonketotic hyperglycinemia nkh as a reference to the biochemical findings seen in patients with the disorder and to distinguish it from the disorders that cause ketotic hyperglycinemia seen in propionic acidemia and several other inherited metabolic disorders to avoid confusion the term glycine encephalopathy is often used as this term more accurately describes the clinical symptoms of the disorder
glycogen branching enzyme deficiency gbed is an inheritable glycogen storage disease affecting american quarter horses and american paint horses it leads to abortion stillbirths or early death of affected animals
glycogen storage disease gsd also glycogenosis and dextrinosis is the result of defects in the processing of glycogen synthesis or breakdown within muscles liver and other cell types gsd has two classes of cause genetic and acquired genetic gsd is caused by any inborn error of metabolism genetically defective enzymes involved in these processes in livestock acquired gsd is caused by intoxication with the alkaloid castanospermine
glycogen storage disease type 0 is a disease characterized by a deficiency in the glycogen synthase enzyme although glycogen synthase deficiency does not result in storage of extra glycogen in the liver it is often classified with the glycogen storage diseases because it is another defect of glycogen storage and can cause similar problems mutations in the liver isoform gys 2 causes fasting hypoglycemia high blood ketones increased free fatty acids and low levels of alanine and lactate conversely feeding in these patients results in hyperglycemia and hyperlactatemia there are two versions the muscle version involves gys 1 and the liver version involves gys 2
glycogen storage disease type i gsd i or von gierke s disease is the most common of the glycogen storage diseases this genetic disease results from deficiency of the enzyme glucose 6 phosphatase and has an incidence in the american population of approximately 1 in 50 000 to 100 000 births the deficiency impairs the ability of the liver to produce free glucose from glycogen and from gluconeogenesis since these are the two principal metabolic mechanisms by which the liver supplies glucose to the rest of the body during periods of fasting it causes severe hypoglycemia and results in increased glycogen storage in liver and kidneys both organs function normally in childhood but are susceptible to a variety of problems in adult years other metabolic derangements include lactic acidosis and hyperlipidemia frequent or continuous feedings of cornstarch or other carbohydrates are the principal treatment other therapeutic measures may be needed for associated problems the disease was named after german doctor edgar von gierke
glycogen storage disease type ii also called pompe disease ˈpɒmpə or acid maltase deficiency is an autosomal recessive metabolic disorder which damages muscle and nerve cells throughout the body it is caused by an accumulation of glycogen in the lysosome due to deficiency of the lysosomal acid alpha glucosidase enzyme it is the only glycogen storage disease with a defect in lysosomal metabolism and the first glycogen storage disease to be identified in 1932 by the dutch pathologist j c pompe the build up of glycogen causes progressive muscle weakness myopathy throughout the body and affects various body tissues particularly in the heart skeletal muscles liver and the nervous system
glycogen storage disease type iii is an autosomal recessive metabolic disorder and inborn error of metabolism characterized by a deficiency in glycogen debranching enzymes it is also known as cori s disease in honor of the 1947 nobel laureates carl cori and gerty cori other names include forbes disease in honor of clinician gilbert burnett forbes 1915 2003 an american physician who further described the features of the disorder or limit dextrinosis due to the limit dextrin like structures in cytosol limit dextrin is the remaining polymer produced after hydrolysis of glycogen without glycogen debranching enzymes to further convert these branched glycogen polymers to glucose limit dextrinosis abnormally accumulates in the cytoplasm glycogen is a molecule the body uses to store carbohydrate energy symptoms of gsd iii are caused by a deficiency of the enzyme amylo 1 6 glucosidase or debrancher enzyme this causes excess amounts of an abnormal glycogen to be deposited in the liver muscles and in some cases the heart
glycogen storage disease type iv is a rare hereditary metabolic disorder it is the result of a mutation in gbe 1 gene which causes a defect in the glycogen branching enzyme therefore glycogen is not made properly and abnormal glycogen molecules accumulate in cells most severely in cardiac and muscle cells the severity of this disease varies on the amount of enzyme produced glycogen storage disease type iv is autosomal recessive which means each parent has a mutant copy of the gene but show no symptoms of the disease it affects 1 in 800 000 individuals worldwide with 3 of all glycogen storage diseases being type iv
glycogen storage disease type ix is a hereditary deficiency of glycogen phosphorylase kinase b that affects the liver and or muscle it is inherited in an x linked or autosomal recessive manner
glycogen storage disease type v gsd v is a metabolic disorder more specifically a glycogen storage disease caused by a deficiency of myophosphorylase its incidence is reported as 1 in 100 000 approximately the same as glycogen storage disease type i gsd type v is also known as mcardle disease or muscle phosphorylase myophosphorylase deficiency the disease was first reported in 1951 by dr brian mcardle of guy s hospital london
glycogen storage disease type vi gsd vi is a type of glycogen storage disease caused by a deficiency in liver glycogen phosphorylase or other components of the associated phosphorylase cascade system it is also known as hers disease after henri g hers who characterized it in 1959 the scope of gsd vi now also includes glycogen storage disease type viii ix caused by phosphorylase b kinase deficiency and x deficiency protein kinase a the incidence of gsd vi is approximately 1 case per 65 000 – 85 000 births representing approximately 30 all cases of glycogen storage disease approximately 75 of these gsd vi cases result from the x linked recessive forms of phosphorylase kinase deficiency all other forms are autosomal recessive
glycogen storage disease type xi is a form of glycogen storage disease it is also known as fanconi – bickel syndrome for guido fanconi and horst bickel who first described it in 1949 it is associated with glut 2 a glucose transport protein which when functioning normally allows glucose to exit several tissues including the liver nephrons and enterocytes of the intestines and enter the blood the syndrome results in hepatomegaly secondary to glycogen accumulation glucose and galactose intolerance fasting hypoglycaemia a characteristic proximal tubular nephropathy and severe short stature
glycogenic acanthosis is a nodular appearance of the mucosa of the esophagus it is seen incidentally in 3 5 of gastroscopies it is also a common finding during fluoroscopic studies of the esophagus
glycoproteinosis are lysosomal storage diseases affecting glycoproteins resulting from defects in lysosomal function the term is sometimes reserved for conditions involving degradation of glycoproteins
glycosphingolipids are a subtype of glycolipids containing the amino alcohol sphingosine alternatively they may be considered as sphingolipids with a carbohydrate attached they include cerebrosides gangliosides globosides
glycosylation see also chemical glycosylation is the reaction in which a carbohydrate i e a glycosyl donor is attached to a hydroxyl or other functional group of another molecule a glycosyl acceptor in biology glycosylation mainly refers in particular to the enzymatic process that attaches glycans to proteins lipids or other organic molecules this enzymatic process produces one of the fundamental biopolymers found in cells along with dna rna and proteins glycosylation is a form of co translational and post translational modification glycans serve a variety of structural and functional roles in membrane and secreted proteins the majority of proteins synthesized in the rough er undergo glycosylation it is an enzyme directed site specific process as opposed to the non enzymatic chemical reaction of glycation glycosylation is also present in the cytoplasm and nucleus as the o glcnac modification aglycosylation is a feature of engineered antibodies to bypass glycosylation five classes of glycans are produced n linked glycans attached to a nitrogen of asparagine or arginine side chains n linked glycosylation requires participation of a special lipid called dolichol phosphate o linked glycans attached to the hydroxyl oxygen of serine threonine tyrosine hydroxylysine or hydroxyproline side chains or to oxygens on lipids such as ceramide phospho glycans linked through the phosphate of a phospho serine c linked glycans a rare form of glycosylation where a sugar is added to a carbon on a tryptophan side chain glypiation which is the addition of a gpi anchor that links proteins to lipids through glycan linkages
gnathitis is jaw inflammation
gnathophyma involves swelling of the chin it is a type of lesion associated with rosacea a common chronic inflammatory skin disorder of the sebaceous oily and fatty glands characterized by redness swelling and acne like pustules other lesions associated with rosacea which affects about 10 percent of fair skinned people normally between the ages of 30 and 50 include rhinophyma enlarged nose metophyma enlarged cushion like swelling of the forehead blepharophyma swelling of the eyelids otophyma a cauliflower like swelling of the earlobes treatment for mild to moderate cases includes an oral antibiotic or topical gel or cream
gnathostomiasis also known as larva migrans profundus is the human infection caused by the nematode roundworm gnathostoma spinigerum and or gnathostoma hispidum which infects vertebrates
gnotobiosis from greek roots gnostos known and bios life is a condition in which all the forms of life present within an organism can be accounted for typically gnotobiotic organisms are germ free or gnotophoric having only one contaminant
in retail terms go backs are items of merchandise which must be placed back on the store shelves they usually accumulate during the store s open hours and comprise a combination of returned items items customers have decided not to purchase and items store employees may have found left lying on the wrong shelf go backs can often accumulate over several days because businesses especially larger department stores tend to have other priorities at the time and not enough employment to put the go backs away go backs are sometimes referred to as re shop put backs misplaced shop backs returns abandons left behinds loose stock or shop downs
in computing goal seeking is the ability to calculate backward to obtain an input that would result in a given output this can also be called what if analysis or back solving it can either be attempted through trial and improvement or more logical means basic goal seeking functionality is built into most modern spreadsheet packages such as microsoft excel according to o brien and marakas optimization analysis is a more complex extension of goal seeking analysis instead of setting a specific target value for a variable the goal is to find the optimum value for one or more target variables given certain constraints then one or more other variables are changed repeatedly subject to the specified constraints until you discover the best values for the target variables
the goblet cell carcinoid abbreviated gcc and also known as crypt cell carcinoma and neuroendocrine tumour with goblet cell differentiation is a rare biphasic gastrointestinal tract tumour that consists of a neuroendocrine component and a conventional carcinoma histologically arising from paneth cells
a godspot is an effect used in stage lighting for the theatre the effect is created using a powerful spotlight usually a beam projector fresnel or ers placed directly above the stage at an angle of less than 10 degrees from vertical i e almost straight down the light has no color gel and is usually directed downwards to hit a single actor or a huddled group of actors with a bright white light the effect is meant to evoke an understanding that god is present and directly watching the scenes proceeding below use of the godspot in this fashion often foreshadows a deus ex machina ending the godspot can also used at times to suggest an angelic nature of a particular character sometimes this effect is used to simulate an alien abduction this is used in the science fiction tv shows stargate sg 1 and stargate atlantis as part of the asgard transporter effect
a goitre british english or goiter american english from the latin gutteria struma is a swelling of the neck or larynx resulting from enlargement of the thyroid gland thyromegaly associated with a thyroid gland that is not functioning properly worldwide over 90 cases of goitre are caused by iodine deficiency
the gold effect is the phenomenon in which a scientific idea particularly in medicine is developed to the status of an accepted position within a professional body or association by the social process itself of scientific conferences committees and consensus building despite not being supported by conclusive evidence the effect was described by professor t gold in 1979 the effect was reviewed by drs petr skrabanek and james mccormick in their book follies and fallacies in medicine the gold effect is used to analyze errors in public health policy and practice such as the widespread use of cholesterol screening in the prevention of cardiovascular disease in their book skrabanek and mccormick describe the gold effect as at the beginning a few people arrive at a state of near belief in some idea a meeting is held to discuss the pros and cons of the idea more people favouring the idea than those disinterested will be present a representative committee will be nominated to prepare a collective volume to propagate and foster interest in the idea the totality of resulting articles based on the idea will appear to show an increasing consensus a specialised journal will be launched only orthodox or near orthodox articles will pass the referees and the editor
a gold gram is the amount of value represented by exactly one gram of gold it is a unit of account frequently used for digital gold currencies it is sometimes denoted by the symbol gg aug or gau a milligram of gold is sometimes referred to as a mil or mgg therefore 1 aug 1 gg 1000 mgg 1000 mil and 1 mil 1 mgg 0 001 gg 0 001 aug this allows gold holdings and transfers to take place in tiny fractions of a gram equivalent to a few cents a possible source of confusion is that gold is often priced on the open market in the more traditional troy ounce one troy ounce is exactly 31 1034768 grams which is larger than the avoirdupois ounce generally in use in the united states and has a mass of 28 35 grams kilogram gold prices are commonly used by the zurich gold pool where 1 000 kilograms one metric tonne
goldbach s conjecture is one of the oldest and best known unsolved problems in number theory and all of mathematics it states every even integer greater than 2 can be expressed as the sum of two primes the conjecture has been shown to hold up through 4 × 1018 but remains unproven despite considerable effort
goldberg – shprintzen is a condition associated with mutations in kiaa 1279 gene which encodes kif binding protein kbp a protein that may interact with microtubules and actin filament kbp may play a key role in cytoskeleton formation and neurite growth hirschsprung s disease may be part of the presentation individuals with the syndrome exhibit ocular ptosis hyperopia or megalocornea cardiac urogenital vesicoureteral reflux multicystic renal dysplasia and skeletal oligodontia scoliosis high arched palate developmental abnormalities
goldblatt kidney is a condition of the kidney in which a constriction of the renal artery causes renal ischemia and the release of renin which would cause hypertension
goldenhar syndrome also known as oculo auriculo vertebral oav syndrome is a rare congenital defect characterized by incomplete development of the ear nose soft palate lip and mandible it is associated with anomalous development of the first branchial arch and second branchial arch common clinical manifestations include limbal dermoids preauricular skin tags and strabismus the term is sometimes used interchangeably with hemifacial microsomia although this definition is usually reserved for cases without internal organ vertebrae disruption it affects between 1 3 500 to 1 26 000 live births with a male female ratio of 3 2
the golem effect is a psychological phenomenon in which lower expectations placed upon individuals either by supervisors or the individual themselves lead to poorer performance by the individual this effect is mostly seen and studied in educational and organizational environments it is a form of self fulfilling prophecy
golfer s elbow or medial epicondylitis is tendinosis of the medial epicondyle of the elbow it is in some ways similar to tennis elbow the anterior forearm contains several muscles that are involved with flexing the digits of the hand and flexing and pronating the wrist the tendons of these muscles come together in a common tendinous sheath which originates from the medial epicondyle of the humerus at the elbow joint in response to minor injury or sometimes for no obvious reason at all this point of insertion becomes inflamed
gomathi amman tamil கோமதி அம்மன் is one of the manifestation of adhi shakthi the temple is popularly known as sankaranayinarkoil or sankarankovil and she is the consort of vanmikanathar and seen along with sankaranarayanar the unification of shiva and vishnu this temple is 900 years old and was built by ukkira pandian tamil உக்கிர பாண்டியன் a king from pandiya dynasty adi thabasu is very famous festival celebrated there every year
the gomberg – bachmann reaction named for the ukrainian american chemist moses gomberg and the american chemist werner emmanuel bachmann is an aryl aryl coupling reaction via a diazonium salt gomberg bachmann reaction the arene compound 1 here benzene is coupled with base with the diazonium salt 2 to the biaryl 3 through an intermediate aryl radical for example p bromobiphenyl may be prepared from 4 bromoaniline and benzene brc 6 h 4 nh 2 c 6 h 6 → brc 6 h 4 − c 6 h 5 the reaction offers a wide scope for both diazonium component and arene component but yields are generally low following the original procedure less than 40 given the many side reactions of diazonium salts several improvements have been suggested one possibility is to employ diazonium tetrafluoroborates in arene solvent together with a phase transfer catalyst another is to use 1 aryl 3 3 dialkyltriazenes
gomez lopez hernandez syndrome glh or cerebellotrigeminal dermal dysplasia is a rare neurocutaneous phakomatosis disorder affecting the trigeminal nerve and causing several other neural and physical abnormalities gomez lopez hernandez syndrome has been diagnosed in only 34 people cases of gomez lopez hernandez syndrome may be under reported as other diseases share the characteristics of cerebellar malformation shown in gomez lopez hernandez syndrome gomez lopez hernandez syndrome was first characterized in 1979
gonadal dysgenesis is any congenital developmental disorder of the reproductive system characterized by a progressive loss of germ cells on the developing gonads of an embryo this loss leads to extremely hypoplastic underdeveloped and dysfunctioning gonads mainly composed of fibrous tissue hence the name streak gonads — i e a form of aplasia in which the ovary is replaced by functionless tissue the accompanying hormonal failure also prevents the development of secondary sex characteristics in either sex resulting in a sexually infantile female appearance and infertility the first type of gonadal dysgenesis discovered was turner syndrome
a gonadal tissue neoplasm is a tumor having any histology characteristic of cells or tissues giving rise to the gonads these tissues arise from the sex cord and stromal cells the tumor may be derived from these tissues or produce them although the tumor is composed of gonadal tissue it is not necessarily located in an ovary or testicle a gonadal tissue neoplasm should not be confused with a urogenital neoplasm though the two topics are often studied together the embryology of the gonads is only indirectly related to the embryology of the external genitals and urinary system
a gonadoblastoma is a complex neoplasm composed of a mixture of gonadal elements such as large primordial germ cells immature sertoli cells or granulosa cells of the sex cord and gonadal stromal cells most gonadoblastomas are benign
gonadotropin releasing hormone gnrh insensitivity is a rare autosomal recessive genetic and endocrine syndrome which is characterized by inactivating mutations of the gonadotropin releasing hormone receptor gnrhr and thus an insensitivity of the receptor to gonadotropin releasing hormone gnrh resulting in a partial or complete loss of the ability of the gonads to synthesize the sex hormones the condition manifests itself as isolated hypogonadotropic hypogonadism ihh presenting with symptoms such as delayed reduced or absent puberty low or complete lack of libido and infertility and is the predominant cause of ihh when it does not present alongside anosmia
resistant ovary syndrome previously known as savage syndrome is a cause of ovarian failure that can lead to secondary amenorrhea resistant ovaries result from a functional disturbance of the gonadotropin receptors in the ovarian follicles it may be a cause of primary or secondary amenorrhea and is resistant to exogenous gonadotropin stimulation diagnosis of this condition requires that the patient has a normal 46 xx karyotype normal secondary sexual characteristics elevated plasma follicle stimulating hormone and luteinizing hormone – in the menopausal range – and that normal multiple follicles are seen on ovarian biopsy spontaneous reversal of the receptor resistance may occur
gonococcemia also known as arthritis – dermatosis syndrome and disseminated gonococcal infection is a condition characterized by a hemorrhagic vesiculopustular eruption bouts of fever and arthralgia or actual arthritis of one or several joints
gonorrhea also spelled gonorrhoea is a sexually transmitted infection caused by the bacterium neisseria gonorrhoeae many people have no symptoms men may have burning with urination discharge from the penis or testicular pain women may have burning with urination vaginal discharge vaginal bleeding between periods or pelvic pain complications in women include pelvic inflammatory disease and in men include inflammation of the epididymis if untreated gonorrhea can occasionally spread to affect joints or heart valves gonorrhea is spread through sexual contact with an infected person this includes oral anal and vaginal sex it can also spread from a mother to a child during birth diagnosis is by testing the urine urethra in males or cervix in females testing all women who are sexually active and less than 25 years of age each year as well as those with new sexual partners is recommended this same recommendation applies in men who have sex with men gonorrhea can be prevented with the use of condoms having sex with only one person who is uninfected and by not having sex treatment is usually with ceftriaxone by injection and azithromycin by mouth resistance has developed to many previously used antibiotics and higher doses of ceftriaxone are occasionally required retesting is recommended three months after treatment sexual partners from the last 2 months should also be treated gonorrhea affects about 0 8 of women and 0 6 of men an estimated 33 to 106 million new cases occur each year out of the 498 million new cases of curable sti – which also includes syphilis chlamydia and trichomoniasis infections in women most commonly occur when they are young adults in 2013 it caused about 3 200 deaths up from 2 300 in 1990 descriptions of the disease date as far back as the old testament
goodpasture syndrome gps also known as goodpasture ’ s disease antiglomerular basement antibody disease or anti gbm disease is a rare autoimmune disease in which antibodies attack the basement membrane in lungs and kidneys leading to bleeding from the lungs and kidney failure it is thought to attack the alpha 3 subunit of type iv collagen which has therefore been referred to as goodpasture s antigen goodpasture syndrome may quickly result in permanent lung and kidney damage often leading to death it is treated with immunosuppressant drugs such as corticosteroids and cyclophosphamide and with plasmapheresis in which the antibodies are removed from the blood famous sufferers include vince earl an actor on the british soap opera brookside who underwent a successful kidney transplant in 2012 the disease was first described by an american pathologist ernest goodpasture of vanderbilt university in 1919 and was later named in his honor
google doodles redirects here for a list of google doodles see lists of google doodles a google doodle is a special temporary alteration of the logo on google s homepage that is intended to celebrate holidays events achievements and people the first google doodle was in honor of the burning man festival of 1998 and was designed by larry page and sergey brin to notify users of their absence in case the servers crashed subsequent google doodles were designed by an outside contractor until page and brin asked intern dennis hwang to design a logo for bastille day in 2000 from that point onward doodles have been organized and published by a team of employees termed doodlers initially doodles were neither animated nor hyperlinked doodles increased in both frequency and complexity by the beginning of the 2010 s and in january 2010 the first animated doodle was posted honoring isaac newton the first interactive doodle appeared shortly thereafter celebrating pac man and hyperlinks also began to be added to doodles usually linking to a search results page for the subject of the doodle by 2014 google had published over 2 000 regional and international doodles throughout its homepages often featuring guest artists musicians and personalities google doodles violate the long accepted tenet of brand management that a logo should be respected and used correctly and consistently at all times a constantly changing logo was thought to reduce brand equity while this may be true of many brands google has successfully defied the orthodoxy the google logo has been noted for the constant interactive engagement that attracts the attention of the press and general public
gordon syndrome gs or distal arthrogryposis type 3 is a rare autosomal dominant disorder characterized by cleft palate and congenital contractures of the hands and feet
gorham s disease pronounced gor amz also known as gorham vanishing bone disease and phantom bone disease is a very rare skeletal condition of unknown cause characterized by the uncontrolled proliferation of distended thin walled vascular or lymphatic channels within bone which leads to resorption and replacement of bone with angiomas and or fibrosis current treatments are experimental only
in medicine gorlin sign is the ability to touch the tip of the nose with the tongue approximately ten percent of the general population can perform this act whereas fifty percent of people with the inherited connective tissue disorder ehlers danlos syndrome can not to be confused with gorlin syndrome it is named for robert j gorlin
gougerot – blum syndrome also known as pigmented purpuric lichenoid dermatitis and pigmented purpuric lichenoid dermatitis of gougerot and blum is a variant of pigmented purpuric dermatitis a skin condition characterized by minute rust colored to violaceous lichenoid papules that tend to fuse into plaques of various hues relative to other variants it is characterized clinically by a male predominance pruritus with a predilection for the legs and histologically it features a densely cellular lichenoid infiltrate it was characterized in 1925
gourmand syndrome is a rare benign condition that sometimes occurs in people who sustain injuries to the right frontal lobe these people develop a new post injury passion for gourmet food it was first described by regard and landis in the journal neurology it is characterized by a right hemisphere brain lesion and a obsessive focus on eating thinking talking and writing about fine foods however it is not associated with an increase in appetite the most famous case of gourmand syndrome developed in a swiss stroke patient after his release from the hospital he immediately quit his job as a political journalist and took up the profession of food critiquing
gradenigo s syndrome also called gradenigo lannois syndrome and petrous apicitis is a complication of otitis media and mastoiditis involving the apex of the petrous temporal bone it was first described by giuseppe gradenigo in 1904 when he reported a triad of symptoms consisting of periorbital unilateral pain related to trigeminal nerve involvement diplopia due to sixth nerve palsy and persistent otorrhea associated with bacterial otitis media with apex involvement of the petrous part of the temporal bone petrositis the classical syndrome related to otitis media has become very rare after the antibiotic era
gradient well formedness is a problem that arises in the analysis of data in generative linguistics in which a linguistic entity is neither completely grammatical nor completely ungrammatical a native speaker may judge a word phrase or pronunciation as not quite right or almost there rather than dismissing it as completely unacceptable or fully accepting it as well formed thus the acceptability of the given entity lies on a gradient between well formedness and ill formedness some generative linguists think that ill formedness might be strictly additive thus trying to figure out universal constraints by acquiring scalar grammaticality judgements from informants generally however gradient well formedness is considered an unsolved problem in generative linguistics
in russia graffiti or street art is an ambiguous phenomenon i e considered to be desecration by some and art by others it is done for a variety of reasons including expressing oneself through an art form or protesting against a corporation or ideology
graft versus host disease gvhd is a medical complication following the receipt of transplanted tissue from a genetically different person gvhd is commonly associated with stem cell or bone marrow transplant but the term also applies to other forms of tissue graft immune cells white blood cells in the donated tissue the graft recognize the recipient the host as foreign the transplanted immune cells then attack the host s body cells gvhd can also occur after a blood transfusion if the blood products used have not been irradiated or treated with an approved pathogen reduction system
graham little syndrome is a cutaneous condition characterized by lichen planus like skin lesions
grain growth is the increase in size of grains crystallites in a material at high temperature this occurs when recovery and recrystallisation are complete and further reduction in the internal energy can only be achieved by reducing the total area of grain boundary the term is commonly used in metallurgy but is also used in reference to ceramics and minerals
grain itch also known as barley itch mattress itch prairie itch and straw itch is a cutaneous condition caused by several types of mites and characterized by intense pruritus
gram negative bacterial infection refers to a disease caused by gram negative bacteria one example is e coli it is important to recognize that this class is defined morphologically by the presence of a bacterial outer membrane and not histologically by a pink appearance when stained though the two usually coincide one reason for this division is that the outer membrane is of major clinical significance it can play a role in the reduced effectiveness of certain antibiotics and it is the source of endotoxin the gram status of some organisms is complex or disputed mycoplasma are sometimes considered gram negative but because of its lack of a cell wall and unusual membrane composition it is sometimes considered separately from other gram negative bacteria gardnerella is often considered gram negative but it is classified in mesh as both gram positive and gram negative it has some traits of gram positive bacteria but has a gram negative appearance it has been described as a gram variable rod
gram negative folliculitis occurs in patients who have had moderately inflammatory acne for long periods and have been treated with long term antibiotics mainly tetracyclines a disease in which cultures of lesions usually reveals a species of klebsiella escherichia coli enterobacter or from the deep cystic lesions proteus
gram negative rosacea is a cutaneous condition that clinically looks like stage ii or iii rosacea
gram negative toe web infection is a cutaneous condition that often begins with dermatophytosis
grande baroque is a sterling silver tableware pattern
grande sonnerie french meaning grand strike is a complication in a mechanical watch or clock which combines a quarter striking mechanism with a repeater on every quarter hour it strikes the number of quarter hours audibly on a gong and then the number of hours since the last hour on a second gong for instance in a 3 weight vienna wall clock at 6 15 it would strike once on a high pitched gong then strike six times on a lower pitched gong at 6 30 it would strike twice on the high pitched gong then six times on the lower pitched gong 6 45 three times on the high pitched gong then six times on the lower pitched gong and at 7 00 it would strike four times on the high pitched gong then seven times on the lower pitched gong you will always know the time at any or every fifteen minutes by just listening to the striking these types of striking clocks are mostly found as carriage clocks or 3 weight vienna regulators in addition it can strike the hours on demand at the push of a button the term is sometimes used erroneously for a mere quarter striking mechanism it is more complex than the petite sonnerie which merely strikes the hours on the hour and the quarter hours on the quarter with no repeater function
grandiose delusions gd or delusions of grandeur are a subtype of delusion that occur in patients suffering from a wide range of psychiatric diseases including two thirds of patients in manic state of bipolar disorder half of those with schizophrenia patients with the grandiose subtype of delusional disorder and a substantial portion of those with substance abuse disorders gds are characterized by fantastical beliefs that one is famous omnipotent wealthy or otherwise very powerful the delusions are generally fantastic and typically have a religious science fictional or supernatural theme there is a relative lack of research into gd in contrast to persecutory delusions and auditory hallucinations about 10 of healthy people experience grandiose thoughts but do not meet full criteria for a diagnosis of gd
granular cell tumor is a tumor that can develop on any skin or mucosal surface but occurs on the tongue 40 of the time it is also known as abrikossoff s tumor granular cell myoblastoma granular cell nerve sheath tumor and granular cell schwannoma
granular convection is a phenomenon where granular material subjected to shaking or vibration will exhibit circulation patterns similar to types of fluid convection it is sometimes described as the brazil nut effect when the largest particles end up on the surface of a granular material containing a mixture of variously sized objects this derives from the example of a typical container of mixed nuts where the largest will be brazil nuts the phenomenon is also known as the muesli effect since it is seen in packets of breakfast cereal containing particles of different sizes but similar density such as muesli mix under experimental conditions granular convection of variously sized particles has been observed forming convection cells similar to fluid motion the convection of granular flows is becoming a well understood phenomenon
granular parakeratosis also known as axillary granular parakeratosis intertriginous granular parakeratosis and more recently zombie patch is a cutaneous condition characterized by brownish red keratotic papules that can coalesce into plaques
granularity also called graininess the quality of being grainy is the extent to which a material or system is composed of distinguishable pieces or grains it can either refer to the extent to which a larger entity is subdivided or the extent to which groups of smaller indistinguishable entities have joined together to become larger distinguishable entities for example a kilometer broken into centimeters has finer granularity than a kilometer broken into meters in contrast molecules of photographic emulsion may clump together to form distinct noticeable granules reflecting coarser granularity coarse grained materials or systems have fewer larger discrete components than fine grained materials or systems a coarse grained description of a system regards large subcomponents while a fine grained description regards smaller components of which the larger ones are composed the concepts granularity coarseness and fineness are relative used when comparing systems or descriptions of systems an example of increasingly fine granularity a list of nations in the united nations a list of all states provinces in those nations a list of all cities in those states etc the terms fine and coarse are used consistently across fields but the term granularity itself is not for example in investing more granularity refers to more positions of smaller size while photographic film that is more granular has fewer and larger chemical grains similarly sugar that is more granular has fewer and larger grains
in medicine granulocytosis is the presence in peripheral blood of an increased number of granulocytes a category of white blood cells often the word refers to an increased neutrophil granulocyte count as neutrophils are the main granulocytes
granuloma is an inflammation found in many diseases it is a collection of immune cells known as histiocytes macrophages granulomas form when the immune system attempts to wall off substances it perceives as foreign but is unable to eliminate such substances include infectious organisms including bacteria and fungi as well as other materials such as keratin and suture fragments
granuloma annulare is a fairly rare chronic dermatological condition which presents as reddish bumps on the skin arranged in a circle or ring it can initially occur at any age and is significantly more common in females 80 20 ratio
granuloma annulare in hiv disease is a skin condition characterized typically by papular and generalized skin lesions
granuloma faciale gf is an uncommon benign chronic skin disease of unknown origin characterized by single or multiple cutaneous nodules usually occurring over the face occasionally extrafacial involvement is noted most often on sun exposed areas
granuloma gluteale infantum is a cutaneous condition that appears in the anogenital region of infants as a complication of diaper dermatitis according to some no granulomas are found
granuloma inguinale also known as donovanosis is a bacterial disease caused by klebsiella granulomatis formerly known as calymmatobacterium granulomatis characterized by ulcerative genital lesions it is endemic in many less developed regions it is also known as donovanosis granuloma genitoinguinale granuloma inguinale tropicum granuloma venereum granuloma venereum genitoinguinale lupoid form of groin ulceration serpiginous ulceration of the groin ulcerating granuloma of the pudendum and ulcerating sclerosing granuloma the disease often goes untreated because of the scarcity of medical treatment in the countries in which it is found in addition the painless genital ulcers can be mistaken for syphilis the ulcers ultimately progress to destruction of internal and external tissue with extensive leakage of mucus and blood from the highly vascular lesions the destructive nature of donovanosis also increases the risk of superinfection by other pathogenic microbes
granuloma multiforme also known as mkar disease and granuloma multiforme leiker is a cutaneous condition most commonly seen in central africa and rarely elsewhere characterized by skin lesions that are on the upper trunk and arms in sun exposed areas it may be confused with tuberculoid leprosy with which it has clinical similarities the condition was first noted by gosset in the 1940 s but it was not until 1964 that leiker coined the term to describe a disease resembling leprosy in his study in nigeria
granulomatosis with polyangiitis gpa previously known as wegener s granulomatosis wg is a systemic disorder that involves both granulomatosis and polyangiitis it is a form of vasculitis inflammation of blood vessels that affects small and medium size vessels in many organs damage to the lungs and kidneys can be fatal it requires long term immunosuppression the condition was originally named for friedrich wegener who described the disease in 1936 as a response to wegener s association with the german nazi party professional bodies and journals have replaced his name with a descriptive name however the older name is still often seen granulomatosis with polyangiitis is part of a larger group of vasculitic syndromes called systemic vasculitides or necrotizing vasculopathies all of which feature an autoimmune attack by an abnormal type of circulating antibody termed ancas antineutrophil cytoplasmic antibodies against small and medium size blood vessels apart from gpa this category includes eosinophilic granulomatosis with polyangiitis egpa and microscopic polyangiitis although gpa affects small and medium size vessels it is formally classified as one of the small vessel vasculitides in the chapel hill system
granulomatous amoebic encephalitis gae is a central nervous system disease caused by certain species of free living amoebae especially species of acanthamoeba and balamuthia mandrillaris the term is most commonly used with acanthamoeba in more modern references the term balamuthia amoebic encephalitis bae is commonly used when balamuthia mandrillaris is the cause
granulomatous facial dermatitis is found in patients with persistent facial erythema involving one or more convex surfaces of the face with lesions that show granulomatous reaction histologically
granulomatous mastitis can be divided into idiopathic granulomatous mastitis also known as granular lobular mastitis and granulomatous mastitis occurring as a rare secondary complication of a great variety of other conditions such as tuberculosis and other infections sarcoidosis and granulomatosis with polyangiitis special forms of granulomatous mastitis occur as complication of diabetes some cases are due to silicone injection silicone induced granulomatous inflammation or other foreign body reactions primary presentation of any of these conditions as mastitis is very rare and in many cases probably predisposed by other breast or systemic conditions although granulomatous mastitis is easily confused with cancer it is a completely benign non cancerous condition treatment is radically different for idiopathic granulomatous mastitis and other granulomatous lesions of the breast the precise diagnosis is therefore very important
granulomatous meningoencephalitis gme is an inflammatory disease of the central nervous system cns of dogs and rarely cats it is a form of meningoencephalitis gme is likely second only to encephalitis caused by canine distemper virus as the most common cause of inflammatory disease of the canine cns the disease is more common in female toy dogs of young and middle age it has a rapid onset the lesions of gme exist mainly in the white matter of the cerebrum brainstem cerebellum and spinal cord the cause is only known to be noninfectious and is considered at this time to be idiopathic because lesions resemble those seen in allergic meningoencephalitis gme is thought to have an immune mediated cause but it is also thought that the disease may be based on an abnormal response to an infectious agent one study searched for viral dna from canine herpesvirus canine adenovirus and canine parvovirus in brain tissue from dogs with gme necrotizing meningoencephalitis and necrotizing leukoencephalitis see below for the latter two conditions but failed to find any
granulomatous prostatitis is an uncommon disease of the prostate an exocrine gland of the male reproductive system it is a form of prostatitis i e inflammation of the prostate resulting from infection bacterial viral or fungal the bcg therapy malacoplakia or systemic granulomatous diseases which involve the prostate
granulomatous slack skin gss is a rare cutaneous condition a variant of lymphoma that typically presents in middle aged adults it is a form of cutaneous t cell lymphoma it is a variant of mycosis fungoides
granulosa cell tumours or granulosa theca cell tumours are tumours that arise from granulosa cells these tumours are part of the sex cord gonadal stromal tumour or non epithelial group of tumours although granulosa cells normally occur only in the ovary granulosa cell tumours occur in both ovaries and testicles see ovarian cancer and testicular cancer these tumours should be considered malignant and treated in the same way as other malignant tumours of ovary the ovarian disease has two forms juvenile and adult both characterized by indolent growth and therefore has high recovery rates the staging system for these tumours is the same as for epithelial tumours and most present as stage i the peak age at which they occur is 50 – 55 years but they may occur at any age juvenile granulosa cell tumour is a similar but distinct rare tumour it too occurs in both the ovary and testis in the testis it is extremely rare and has not been reported to be malignant although this tumour usually occurs in children hence its name it has been reported in adults
granulosis rubra nasi is a rare familial disease of children occurring on the nose cheeks and chin characterized by diffuse redness persistent hyperhidrosis and small dark red papules that disappear on diascopic pressure
grapevine yellows gy are diseases associated to phytoplasmas that occur in many grape growing areas worldwide and are of still increasing significance almost identical symptoms of the gy syndrome are caused by different phytoplasmas and appear on leaves shoots and clusters of grapevine typical symptoms include discoloration and necrosis of leaf veins and leaf blades downward curling of leaves lack or incomplete lignification of shoots stunting and necrosis of shoots abortion of inflorescences and shrivelling of berries those symptoms are related to callose deposition at the sieve plates and subsequent degeneration of the phloem although no resistant cultivars of vitis vinifera or rootstocks are known so far the various grape varieties differ considerably as far as symptom severity is concerned it ranges from fast decline and death in highly susceptible cultivars to tolerant rootstocks as symptomless carriers of the pathogen the main viticultural production areas in the republic of macedonia were surveyed in 2006 2007 2008 for the presence of grapevine yellows pcr and rflp analyses were used to detect and identify phytoplasmas infecting grapevines only phytoplasmas associated with “ bois noir ” disease ribosomal subgroup 16 srxii a or stolbur were detected molecular analyses showed that all phytoplasmas identified belonged to tuf type ii vkii
in graph theory a branch of mathematics graph canonization is the problem finding a canonical form of a given graph g a canonical form is a labeled graph canon g that is isomorphic to g such that every graph that is isomorphic to g has the same canonical form as g thus from a solution to the graph canonization problem one could also solve the problem of graph isomorphism to test whether two graphs g and h are isomorphic compute their canonical forms canon g and canon h and test whether these two canonical forms are identical the canonical form of a graph is an example of a complete graph invariant every two isomorphic graphs have the same canonical form and every two non isomorphic graphs have different canonical forms conversely every complete invariant of graphs may be used to construct a canonical form the vertex set of an n vertex graph may be identified with the integers from 1 to n and using such an identification a canonical form of a graph may also be described as a permutation of its vertices canonical forms of a graph are also called canonical labelings and graph canonization is also sometimes known as graph canonicalization
the graph isomorphism problem is the computational problem of determining whether two finite graphs are isomorphic the problem is neither known to be solvable in polynomial time nor np complete and therefore may be in the computational complexity class np intermediate it is known that the graph isomorphism problem is in the low hierarchy of class np which implies that it is not np complete unless the polynomial time hierarchy collapses to its second level at the same time isomorphism for many special classes of graphs can be solved in polynomial time and in practice graph isomorphism can often be solved efficiently this problem is a special case of the subgraph isomorphism problem which is known to be np complete it is also known to be a special case of the non abelian hidden subgroup problem over the symmetric group
in structure mining a domain of learning on structured data objects in machine learning a graph kernel is a kernel function that computes an inner product on graphs graph kernels can be intuitively understood as functions measuring the similarity of pairs of graphs they allow kernelized learning algorithms such as support vector machines to work directly on graphs without having to do feature extraction to transform them to fixed length real valued feature vectors they find applications in bioinformatics in chemoinformatics as a type of molecule kernels and in social network analysis graph kernels were first described in 2002 by r i kondor and john laffertyas kernels on graphs i e similarity functions between the nodes of a single graph with the world wide web hyperlink graph as a suggested application vishwanathan et al instead defined kernels between graphs an example of a kernel between graphs is the random walk kernel which conceptually performs random walks on two graphs simultaneously then counts the number of paths that were produced by both walks this is equivalent to doing random walks on the direct product of the pair of graphs and from this a kernel can be derived that can be efficiently computed
graph literacy is the ability to understand information presented graphically including general knowledge about how to extract information and make inferences from different graphical formats although related graph literacy is distinct from other forms of literacy e g general health literacy or numeracy in the sense that it relates more specifically to one ’ s ability to obtain meaning from information presented graphically it can include the storage of mental representations in long term memory knowledge about the properties of different types of formats and procedures to interpret them however similar to other types of literacy higher graph literacy is associated with higher education levels and suggests that developing the skills required to interpret graphical information requires knowledge that is acquired through formal education and experience graph literacy is important in everyday life graphs appear throughout the published media in newspapers and magazines on tv and on the internet and are used to provide information for many important decisions including medical nutritional financial and political choices yet many people can have difficulty understanding even the simplest graphs up to one third of the general population lacks the skills needed to understand basic numerical formats e g percentages or ratios and basic graphic displays such as bar or pie charts line graphs or icon arrays while graphical displays can improve understanding and comprehension of quantitative information such as the risks and benefits of medical treatments they may not be helpful for everyone visual displays may be of greater help to people with low numeracy whereas numbers may be better for people who have poor graph literacy determining what type of information displays lead to better comprehension of information and for whom is an ongoing topic of research particularly within the area of risk communication
in graph theory and computer science the graph sandwich problem is a problem of finding a graph that belongs to a particular family of graphs and is sandwiched between two other graphs one of which must be a subgraph and the other of which must be a supergraph of the desired graph graph sandwich problems generalize the problem of testing whether a given graph belongs to a family of graphs and have attracted attention because of theirapplications and as a natural generalization of recognition problems
graphesthesia is the ability to recognize writing on the skin purely by the sensation of touch its name derives from greek graphē writing and aisthēsis perception graphesthesia tests combined cortical sensation therefore it is necessary that primary sensation be intact during medical or neurological examination graphesthesia is tested in order to test for certain neurological conditions such as lesions in brainstem spinal cord sensory cortex or thalamus an examiner writes single numbers or simple letters on the skin usually the palm with something that will provide a clear stimulus such as a broken tongue depressor pen cap etc prior to the start of testing an agreement may be reached between the examiner and the patient as to the orientation of the letters although this is often unnecessary since orientation and size of the figures are rarely an issue the crucial aspect of testing graphesthesia as with any sensory testing is to establish that the patient understands the test hence the test is commenced in the hemiplegic patient on the normal intact hand this also allows the examiner to establish the patient s numeracy since semi numerate patients may have difficulties performing the task the patient provides a verbal response identifying the figure that was drawn if the patient has a speech or language impairment that prevents them from verbalizing an answer the answer can be selected from a series of images shown to them loss of graphesthesia indicates either parietal lobe damage on the side opposite the hand tested or damage to the dorsal columns pathway at any point between the tested point and the contralateral parietal lobe the major clinical utility of the test in the 21 st century is in the condition cortico basal ganglionic degeneration where in addition to evidence of basal ganglia dysfunction the presence of cortical sensory loss is likely to have reasonably high specificity for the diagnosis testing graphesthesia can be substituted for stereognosis if a patient is unable to grasp an object
in psychology graphorrhea is a communication disorder expressed by excessive wordiness with minor or sometimes incoherent rambling specifically in written work graphorrhea is sometimes classified as a mental illness resulting in a variety of psychiatric and neurological disorders including aphasia localized cortical lesions in the thalamus mania or most typically in catatonic schizophrenia some ramblings may follow all any grammatical rule s but still leave the reader confused and unsure about what the piece is about
graping is a phenomenon marked by the appearance of unreflowed solder particles on top of the solder mass the solder that is partially coalesced looks like a cluster of grapes which is where the phenomenon ’ s name is derived
grass tetany or hypomagnesemic tetany also known as grass staggers and winter tetany is a metabolic disease involving magnesium deficiency which can occur in such ruminant livestock as beef cattle dairy cattle and sheep usually after grazing on pastures of rapidly growing grass especially in early spring
grassland degradation also called vegetation or steppe degradation is a biotic disturbance in which grass struggles to grow or can no longer exist on a piece of land due to causes such as overgrazing burrowing of small mammals and climate change since the 1970 s it has been noticed to affects plains and plateaus of alpine meadows or grasslands most notably being in the philippines and in the tibetan and inner mongolian region of china where 2460 km 2 of grassland is degraded each year across the globe it is estimated that 23 of the land is degraded it takes years and sometimes even decades depending on what is happening to that piece of land for a grassland to become degraded the process is slow and gradual but at the same time so is restoring degraded grassland initially only patches of grass appear to die and appear brown in nature but the degradation process if not addressed can spread to decimate many acres of land which in the most severe cases is merely bare black soil bereft of any usefulness as a result the frequency of landslides and dust storms increases the degraded land ’ s less fertile ground cannot yield any produce nor can animals graze in these fields any longer a dramatic decrease in plant diversity in this ecosystem and more carbon and nitrogen are released into the atmosphere these results can have serious effects on humans such as displacing herders from their community a decrease in vegetables fruit and meat that are regularly acquired from these fields and a catalyzing effect on global warming
gratification is the pleasurable emotional reaction of happiness in response to a fulfillment of a desire or goal gratification like all emotions is a motivator of behavior and thus plays a role in the entire range of human social systems
grave goods in archaeology and anthropology are the items buried along with the body they are usually personal possessions supplies to smooth the deceased s journey into the afterlife or offerings to the gods grave goods may be classed as a type of votive deposit most grave goods recovered by archaeologists consist of inorganic objects such as pottery and stone and metal tools but organic objects that have since decayed were also placed in ancient tombs funerary art is a broad term but generally means artworks made specifically to decorate a burial place such as miniature models of possessions including slaves or servants for use in the afterlife where grave goods appear grave robbery is a potential problem etruscans would scratch the word śuθina etruscan for from a tomb on grave goods buried with the dead to discourage their reuse by the living the tomb of pharaoh tutankhamun is famous because it was one of the few egyptian tombs that was not thoroughly looted in ancient times grave goods can be regarded as a sacrifice intended for the benefit of the deceased in the afterlife closely related are customs of ancestor worship and offerings to the dead in modern western culture related to all souls day day of the dead in east asia the hell bank note and related customs also closely related is the custom of retainer sacrifice where servants or wives of a deceased chieftain are interred with the body as the inclusion of expensive grave goods and of slaves or retainers became a sign of high status in the bronze age the prohibitive cost led to the development of fake grave goods where artwork meant to depict grave goods or retainers is produced for the burial and deposited in the grave in place of the actual sacrifice
graves disease also known as toxic diffuse goiter is an autoimmune disease that affects the thyroid it frequently results in and is the most common cause of hyperthyroidism it also often results in an enlarged thyroid signs and symptoms of hyperthyroidism may include irritability muscle weakness sleeping problems a fast heartbeat poor tolerance of heat diarrhea and weight loss other symptoms may include thickening of the skin on the shins known as pretibial myxedema and eye bulging a condition caused by graves ophthalmopathy about 25 to 80 of people with the condition develop eye problems the exact cause is unclear however it is believed to involve a combination of genetic and environmental factors a person is more likely to be affected if they have a family member with the disease if one twin is affected there is a 30 chance the other twin will also have the disease the onset of disease may be triggered by stress infection or giving birth those with other autoimmune diseases such as type 1 diabetes and rheumatoid arthritis are more likely to be affected smoking increases the risk of disease and may worsen eye problems the disorder results from an antibody called thyroid stimulating immunoglobulin tsi that has a similar effect to thyroid stimulating hormone tsh these tsi antibodies cause the thyroid gland to produce excess thyroid hormone the diagnosis may be suspected based on symptoms and confirmed with blood tests and radioiodine uptake typically blood tests show a raised t 3 and t 4 low tsh increased radioiodine uptake in all areas of the thyroid and tsi antibodies there are three treatment options radioiodine therapy medications and thyroid surgery radioiodine therapy involves taking iodine 131 by mouth which is then concentrated in and destroys the thyroid over weeks to months the resulting hypothyroidism is treated with synthetic thyroid hormone medications such as beta blockers may control some of the symptoms and anti thyroid medications such as methimazole may temporarily help people while other treatments are having effect surgery to remove the thyroid is another option eye problems may require additional treatments graves disease will develop in about 0 5 of males and 3 of females it occurs about 7 5 times more often in women than men often it starts between the ages of 40 and 60 but can begin at any age it is the most common cause of hyperthyroidism in the united states about 50 to 80 of cases the condition is named after robert graves who described it in 1835 a number of prior descriptions also exist
graves ophthalmopathy also known as thyroid eye disease ted dysthyroid thyroid associated orbitopathy tao graves orbitopathy is an autoimmune inflammatory disorder affecting the orbit around the eye characterized by upper eyelid retraction lid lag swelling redness erythema conjunctivitis and bulging eyes exopthalmos it is part of a systemic process with variable expression in the eyes thyroid and skin caused by autoantibodies that bind to tissues in those organs and in general occurs with hyperthyroidism the most common form of hyperthyroidism is graves disease about 10 of cases do not have graves disease but do have autoantibodies the autoantibodies target the fibroblasts in the eye muscles and those fibroblasts can differentiate into fat cells adipocytes fat cells and muscles expand and become inflamed veins become compressed and are unable to drain fluid causing edema annual incidence is 16 100 000 in women 3 100 000 in men about 3 5 have severe disease with intense pain and sight threatening corneal ulceration or compression of the optic nerve cigarette smoking which is associated with many autoimmune diseases raises the incidence 7 7 fold mild disease will often resolve and merely requires measures to reduce discomfort and dryness such as artificial tears and smoking cessation if possible severe cases are a medical emergency and are treated with glucocorticoids steroids and sometimes ciclosporin many anti inflammatory biological mediators such as infliximab etanercept and anakinra are being tried but there are no randomized controlled trials demonstrating effectiveness
gravitational compression is a phenomenon in which gravity acting on the mass of an object compresses it reducing its size and increasing the object s density at the center of a planet or star gravitational compression produces heat by the kelvin – helmholtz mechanism this is the mechanism that explains how jupiter continues to radiate heat produced by its gravitational compression the most common reference to gravitational compression is with respect to stellar evolution the sun and other main sequence stars are produced by the initial gravitational collapse of a molecular cloud assuming the mass of the material is large enough gravitational compression reduces the size of the core increasing its temperature until hydrogen fusion can begin this hydrogen to helium fusion reaction releases energy that balances the inward gravitational pressure and the star becomes stable for millions of years no further gravitational compression occurs until the hydrogen is nearly used up reducing the thermal pressure of the fusion reaction at the end of the sun s life gravitational compression will turn it into a white dwarf at the other end of the scale are massive stars which burn their fuel very quickly ending their lives as supernovae after which further gravitational compression will produce either a neutron star or a black hole from the remnants for planets and moons equilibrium is reached when the compression due to gravity is balanced by a pressure gradient in the opposite direction due to the strength of the material at which point gravitational compression ceases
gravitational microlensing is an astronomical phenomenon due to the gravitational lens effect it can be used to detect objects that range from the mass of a planet to the mass of a star regardless of the light they emit typically astronomers can only detect bright objects that emit much light stars or large objects that block background light clouds of gas and dust these objects make up only a tiny portion of the mass of a galaxy microlensing allows the study of objects that emit little or no light when a distant star or quasar gets sufficiently aligned with a massive compact foreground object the bending of light due to its gravitational field as discussed by einstein in 1915 leads to two distorted unresolved images resulting in an observable magnification the time scale of the transient brightening depends on the mass of the foreground object as well as on the relative proper motion between the background source and the foreground lens object since microlensing observations do not rely on radiation received from the lens object this effect therefore allows astronomers to study massive objects no matter how faint it is thus an ideal technique to study the galactic population of such faint or dark objects as brown dwarfs red dwarfs planets white dwarfs neutron stars black holes andmassive compact halo objects moreover the microlensing effect is wavelength independent allowing study of source objects that emit any kind of electromagnetic radiation microlensing by an isolated object was first detected in 1989 since then microlensing has been used to constrain the nature of the dark matter detect exoplanets study limb darkening in distant stars constrain the binary star population and constrain the structure of the milky way s disk microlensing has also been proposed as a means to find dark objects like brown dwarfs and black holes study starspots measure stellar rotation and probe quasars including their accretion disks
a gravitational mirage or cosmic mirage is an optical phenomenon affecting the appearance of a distant star or galaxy seen only through a telescope it can take the form of a ring or rings partially or completely surrounding the object a duplicate image adjacent to the object or multiple duplicate images surrounding the object sometimes the direct view of the original object itself is dimmed or absent the illusion is caused by a gravitational lens in space between the object and the observer s telescope which bends light as it travels the effect is analogous to the atmospheric mirage which has been observed since antiquity in circumstances where the air temperature varies strongly with height over the ground or sea the rapidly changing refractive index bends light producing inverted and or multiple images floating in the air ring shaped gravitational mirages are referred to as einstein rings and one multiple image gravitational mirage is named the einstein cross as tribute for einstein s predictions regarding gravitational lensing
gravity or gravitation is a natural phenomenon by which all things with mass are brought toward or gravitate toward one another including planets stars and galaxies since energy and mass are equivalent all forms of energy including light also cause gravitation and are under the influence of it on earth gravity gives weight to physical objects and causes the ocean tides the gravitational attraction of the original gaseous matter present in the universe caused it to begin coalescing forming stars — and the stars to group together into galaxies — so gravity is responsible for many of the large scale structures in the universe gravity has an infinite range although its effects become increasingly weaker on farther objects gravity is most accurately described by the general theory of relativity proposed by albert einstein in 1915 which describes gravity not as a force but as a consequence of the curvature of spacetime caused by the uneven distribution of mass energy the most extreme example of this curvature of spacetime is a black hole from which nothing can escape once past its event horizon not even light more gravity results in gravitational time dilation where time lapses more slowly at a lower stronger gravitational potential however for most applications gravity is well approximated by newton s law of universal gravitation which postulates that gravity causes a force where two bodies of mass are directly drawn or attracted to each other according to a mathematical relationship where the attractive force is directly proportional to the product of their masses and inversely proportional to the square of the distance between them gravity is the weakest of the four fundamental interactions of nature the gravitational attraction is approximately 1038 times weaker than the strong force 1036 times weaker than the electromagnetic force and 1029 times weaker than the weak force as a consequence gravity has a negligible influence on the behavior of subatomic particles and plays no role in determining the internal properties of everyday matter but see quantum gravity on the other hand gravity is the dominant interaction at the macroscopic scale and is the cause of the formation shape and trajectory orbit of astronomical bodies it is responsible for various phenomena observed on earth and throughout the universe for example it causes the earth and the other planets to orbit the sun the moon to orbit the earth the formation of tides the formation and evolution of the solar system stars and galaxies the earliest instance of gravity in the universe possibly in the form of quantum gravity supergravity or a gravitational singularity along with ordinary space and time developed during the planck epoch up to 10 − 43 seconds after the birth of the universe possibly from a primeval state such as a false vacuum quantum vacuum or virtual particle in a currently unknown manner for this reason in part pursuit of a theory of everything the merging of the general theory of relativity and quantum mechanics or quantum field theory into quantum gravity has become an area of research
a gravity anomaly is the difference between the observed acceleration of a planet s reaction to gravity and a value predicted from a model a location with a positive anomaly exhibits more gravity than predicted while a negative anomaly exhibits a lower value than predicted the anomaly is the body or effect that causes the deviation from the ideal gravity model many data corrections must be made to the measured gravity value in order to extract the response of the local anomaly or local geology which is typically the goal of applied geophysics
gravity spreading is the phenomenon in which a geological body laterally extends and vertically contracts in order to reduce its gravitational potential energy it has been observed on many different scales and at numerous locations on earth from rhyolite lava flows to passive margins additionally gravity spreading is thought to have occurred on both mars and venus
gray baby syndrome also termed gray or grey syndrome is a rare but serious side effect that occurs in newborn infants especially premature babies following the accumulation of antimicrobial chloramphenicol
the gray ceiling is a business societal phenomenon where the existing workforce of those born during the baby boom era prevents the slightly younger generation xers from advancing or being promoted at their jobs
the development of the brain in the human fetus is extraordinarily complex and is still not fully understood neural matter originates in the outer ectodermic layer of the gastrula thus it originates from the cell layer primarily responsible for skin hair nails etc rather than from the layers that develop into other internal organs the nervous system originates as a tiny simple open tube called the neural tube the front of this tube develops into the brain and retinas of the eye while the spinal cord develops from the very back end neurons begin to form early but most of them become structural rather than active nerve cells the brain generally forms from the inside out especially in the case of the neocortex the difficulties arising from this are readily apparent as each successive layer of cells must travel through the previous layer to reach its destination therefore nervous tissue develops ladders made of radial glial cells that neurons climb through the previous layers to reach their proper destination some destinations such as the cerebral cortex even have placeholder neurons that travel up the ladder to form a structure when the final neurons germinate they find a correct placeholder and then the placeholder cell dies
gray platelet syndrome gps or platelet alpha granule deficiency is a rare congenital autosomal recessive bleeding disorder caused by a reduction or absence of alpha granules in blood platelets and the release of proteins normally contained in these granules into the marrow causing myelofibrosis gps is primarily inherited in an autosomal recessive manner and the gene that is mutated in gps has recently been mapped to chromosome 3 p and identified as nbeal 2 nbeal 2 encodes a protein containing a beach domain that is predicted to be involved in vesicular trafficking it is expressed in platelets and megakaryocytes and is required for the development of platelet alpha granules nbeal 2 expression is also required for the development of thrombocytes in zebrafish gps is characterized by thrombocytopenia and abnormally large agranular platelets in peripheral blood smears the defect in gps is the failure of megakaryocytes to package secretory proteins into alpha granules patients with the gps are affected by mild to moderate bleeding tendencies
gray zone lymphoma often presenting as large tumors in the mediastinum is a type of lymphoma that is characterized by having cellular features of both classic hodgkin s lymphomas chl and large b cell lymphomas
graziela preiser is a pattern and textile designer who is well known in germany for her 1970 s designs born in germany she was educated at the werkkunstschule hannover now called akademie der bildenden künste for the majority of her career she worked as a creative director graphic designer and illustrator alongside her work for several lifestyle magazines she is best known for her print and textile designs of the 1970 s she gained an international audience through exposure in the magazine brigitte by 1973 the name graziela had become synonymous with her style typical of her creations are cheerful colours and a clear timeless graphic design which was hugely popular in the 1970 s in 2008 she founded the company bygraziela to relaunch her 1970 s designs
grazing pressure is the stress on plant populations due to the grazing of animals plants may be lost either directly as a result of animals grazing upon them or indirectly as a result of damage to the vegetation or ecosystem by animals moving through the area usually the term refers to introduced pastoral animals such as cattle and sheep but in some contexts it may mean introduced feral animals or even native animals
greasy hair is a hair condition which is common in humans one of four main four types of hair conditioning — normal greasy dry and greasy dry it is primarily caused by build up of the natural secretion from the sebaceous glands in the scalp and is characterised by the continuous development of natural grease on the scalp a chronic condition of greasy hair may often accompany chronic greasy skin conditions on the face and body and oily skin and acne excessive carbohydrate fat and starch consumption can increase the likelihood of developing greasy hair and also poor personal hygiene and not washing the hair for a long duration will lead to a buildup of sebum in the hair follicles hair conditioners can decrease the likelihood of developing greasy hair after shampooing some cosmetics companies produce shampoos and conditioners specifically to deal with greasy hair and for oily or dry hair problems massaging the scalp and exposure to the sun can reduce the problem of greasy hair in some men a greased back wet hair look is considered desirable and numerous hair gels and waxes specialize in giving a wet look appearance
the great disappointment in the millerite movement was the reaction that followed baptist preacher william miller s proclamations that jesus christ would return to the earth in 1844 what he called the advent his study of the daniel 8 prophecy during the second great awakening led him to the conclusion that daniel ’ s “ cleansing of the sanctuary ” was cleansing of the earth from sin when christ would come and he and many others prepared but october 22 1844 came and they were disappointed however it paved the way for the adventists who formed the seventh day adventist church who came to the understanding that what had happened on oct 22 was not of jesus ’ return as miller had thought but the start of jesus ’ final work of atonement the cleansing in the heavenly sanctuary leading up to the second coming
the great male renunciation is the historical phenomenon at the end of the 18 th century for menswear to stop using brilliant or refined forms which were left to women s clothing coined by psychoanalyst john flügel in 1930 it is considered a major turning point in the history of clothing in which the men relinquish their claim to adornment and beauty the great renunciation encouraged the establishment of the suit s monopoly on male dress codes at the beginning of 19 th century
greater india is the historical extent of indian culture beyond the indian subcontinent this particularly concerns the spread of hinduism and buddhism from india to southeast asia central asia and china by the silk road during the early centuries of the common era and the spread of the indian writing systems like the pallava script of the south indian pallava dynasty to southeast asia and siddhaṃ script to east asia through gupta empire by the travellers and maritime traders of the 5 th to 15 th centuries it also describes the establishment of indianised kingdoms in southeast asia and the spread of the indian script architecture and administration to the west greater india overlaps with greater persia in the hindu kush and pamir mountains the term is tied to the geographic uncertainties surrounding the indies during the age of exploration
greater kamrup was the historical extent of the political boundaries and culture of kamrup beyond the current cultural sphere this particularly concerns the spread of political boundaries of kamrup kingdom through expansion and conquest but may also refer to the spread of kamrupi culture to the east and southwards during the early centuries of the common era to the west expansion of political boundaries towards north bengal and eastern bihar and expansion towards south east to bengal and north odisha the term is tied to the geographic uncertainties surrounding the kamrup during the first millennium and early second millennium
greater trochanteric pain syndrome gtps also known as trochanteric bursitis is inflammation of the trochanteric bursa a part of the hip this bursa is at the top outer side of the femur between the insertion of the gluteus medius and gluteus minimus muscles into the greater trochanter of the femur and the femoral shaft it has the function in common with other bursae of working as a shock absorber and as a lubricant for the movement of the muscles adjacent to it occasionally this bursa can become inflamed and clinically painful and tender this condition can be a manifestation of an injury often resulting from a twisting motion or from overuse but sometimes arises for no obviously definable cause the symptoms are pain in the hip region on walking and tenderness over the upper part of the femur which may result in the inability to lie in comfort on the affected side more often the lateral hip pain is caused by disease of the gluteal tendons that secondarily inflames the bursa this is most common in middle aged women and is associated with a chronic and debilitating pain which does not respond to conservative treatment other causes of trochanteric bursitis include uneven leg length iliotibial band syndrome and weakness of the hip abductor muscles greater trochanteric pain syndrome can remain incorrectly diagnosed for years because it shares the same pattern of pain with many other musculoskeletal conditions thus people with this condition may be labeled malingerers or may undergo many ineffective treatments due to misdiagnosis it may also coexist with low back pain arthritis and obesity
greco buddhist art is the artistic manifestation of greco buddhism a cultural syncretism between the classical greek culture and buddhism which developed over a period of close to 1000 years in central asia between the conquests of alexander the great in the 4 th century bc and the islamic conquests of the 7 th century ad greco buddhist art is characterized by the strong idealistic realism and sensuous description of hellenistic art and the first representations of the buddha in human form which have helped define the artistic and particularly sculptural canon for buddhist art throughout the asian continent up to the present it is also a strong example of cultural syncretism between eastern and western traditions the origins of greco buddhist art are to be found in the hellenistic greco bactrian kingdom 250 bc 130 bc located in today ’ s afghanistan from which hellenistic culture radiated into the indian subcontinent with the establishment of the indo greek kingdom 180 bc 10 bc under the indo greeks and then the kushans the interaction of greek and buddhist culture flourished in the area of gandhara in today ’ s northern pakistan before spreading further into india influencing the art of mathura and then the hindu art of the gupta empire which was to extend to the rest of south east asia the influence of greco buddhist art also spread northward towards central asia strongly affecting the art of the tarim basin and ultimately the arts of china korea and japan
the greek withdrawal from the eurozone is the potential exit of greece from the eurozone monetary union in the 2010 s primarily for the country to deal with its government debt crisis the controversial and much discussed possible exit is often referred to as grexit a portmanteau combining the english words greek and exit the term was coined by the citigroup economist ebrahim rahbari and was introduced by rahbari and citigroup s global chief economist willem h buiter on 6 february 2012 proponents of the proposal argue that leaving the euro and reintroducing the drachma would dramatically boost exports and tourism and encourage the local economy while discouraging expensive imports opponents argue that the proposal would impose excessive hardship on the greek people cause civil unrest destabilize and harm the reputation of the eurozone and could cause greece to align more with non eu states on 27 january 2015 two days after an early election of the greek parliament alexis tsipras leader of the new syriza coalition of the radical left party formed a new government he appointed yanis varoufakis as minister of finance a particularly important post in view of the government debt crisis since then the chance of a grexit or even a graccident accidental grexit in the near future has been widely discussed after the announcement of the bailout referendum on 27 june 2015 speculation rose that day bbc news reported that default appears inevitable though it later removed the online statement on 29 june 2015 it was announced that greek banks would remain closed all week cash withdrawals from banks would be limited to € 60 per day and international money transfers would be limited to urgent pre approved commercial transfers
green tobacco sickness gts is a type of nicotine poisoning caused by the dermal absorption of nicotine from the surface of wet tobacco plants tobacco harvesters whose clothing becomes saturated from tobacco wet with rain or morning dew are at high risk of developing gts workers can avoid getting this sickness by waiting to harvest until the tobacco leaves are dry or by wearing a rain suit wet clothing that has come in contact with tobacco leaves should be removed immediately and the skin washed with warm soapy water nicotine from other sources including nicotine gum a nicotine patch or electronic cigarette or other tobacco products like cigarettes or smokeless tobacco appears to reduce the risk of gts due to the body adapting to the intake of nicotine symptoms of gts include nausea vomiting headache dizziness and severe weakness these symptoms may be accompanied by fluctuations in blood pressure or heart rate abdominal cramping chills increased sweating salivation and difficulty breathing are also common the illness will resolve on its own within one to two days but symptoms may be so severe as to require emergency medical treatment in the united states where tobacco is increasingly being farmed on large farms seasonal or migrant farmworkers are disproportionately affected by this condition worldwide there are an estimated 33 million tobacco farm workers with a substantial proportion living in developing countries a recent international review reported that between 8 89 of tobacco harvesters may be affected in the course of a season this wide variation probably being due to differences between study methodologies as well as a range of working conditions the long term health outcomes for individuals exposed to nicotine transdermally for extended periods of time are not known
green nail syndrome also known as chloronychia is a paronychial infection caused due to pseudomonas aeruginosa that can develop in individuals whose hands are frequently submerged in water it may also occur as transverse green stripes that are ascribed to intermittent episodes of infection
a greenstick fracture is a fracture in a young soft bone in which the bone bends and breaks greenstick fractures usually occur most often during infancy and childhood when bones are soft the name is by analogy with green i e fresh wood which similarly breaks on the outside when bent it was discovered by british american orthopedist john insall and polish american orthopedist michael slupecki
greig cephalopolysyndactyly syndrome is a disorder that affects development of the limbs head and face the features of this syndrome are highly variable ranging from very mild to severe people with this condition typically have one or more extra fingers or toes polydactyly or an abnormally wide thumb or big toe hallux the skin between the fingers and toes may be fused cutaneous syndactyly this disorder is also characterized by widely spaced eyes ocular hypertelorism an abnormally large head size macrocephaly and a high prominent forehead rarely affected individuals may have more serious medical problems including seizures mental retardation and developmental delay
in the dungeons dragons fantasy role playing game the grell is an aberration
a greyout us english grayout is a transient loss of vision characterized by a perceived dimming of light and color sometimes accompanied by a loss of peripheral vision it is a precursor to fainting or a blackout and is caused by hypoxia low brain oxygen level often due to a loss of blood pressure greyouts have a variety of possible causes shock such as hypovolemia even in mild form such as when drawing blood suddenly standing up see orthostatic hypotension especially if sick hungover or suffering from low blood pressure positive g forces as experienced by pilots or roller coaster riders paradoxically hyperventilation self induced hypocapnia such as in the fainting game or in shallow water blackout overexertion panic attack usually recovery is rapid and a greyout can be readily reversed by lying down this way the cardiovascular system does not need to work against gravity for blood to reach the brain a grey out may be experienced by aircraft pilots pulling high positive g forces as when pulling up into a loop or a tight turn forcing blood to the lower extremities of the body and lowering blood pressure in the brain this is the reverse of a redout or a reddening of the vision which is the result of negative g forces caused by performing an outside loop that is by pushing the nose of the aircraft down redouts are potentially dangerous and can cause retinal damage and hemorrhagic stroke pilots of high performance aircraft can increase their resistance to greyout by using a g suit which controls the pooling of blood in the lower limbs but there is no suit yet capable of controlling a redout in both cases symptoms may be remedied immediately by easing pressure on the flight controls continued or heavy g force will rapidly progress to g loc g force induced loss of consciousness surprisingly even during a heavy grey out where the visual system is severely impaired pilots can still hear feel and speak in other words complete grey out and loss of consciousness are separate events another common occurrence of greyouts are in roller coaster riders many roller coasters put riders through positive g forces particularly in vertical loops and helices roller coasters rarely have high enough negative g forces to induce redouts as most low g elements are designed to simulate weightlessness
in the dungeons and dragons fantasy role playing game the grick is an aberration a grick resembles a large roughly 8 feet long darkly colored worm or snake like creature its beak is ringed by four barbed tentacles which are its main weapons
in politics gridlock or deadlock or political stalemate refers to a situation when there is difficulty passing laws that satisfy the needs of the people a government is gridlocked when the ratio between bills passed and the agenda of the legislature decreases think of laws as the supply and the legislative agenda as demand gridlock can occur when two legislative houses or the executive branch and the legislature are controlled by different political parties or otherwise cannot agree
the grieco elimination is an organic reaction describing the elimination reaction of an aliphatic primary alcohol through a selenide to a terminal alkene it is named for paul grieco the alcohol first reacts with o nitrophenylselenocyanate and tributylphosphine to form a selenide via a nucleophilic substitution on the electron deficient selenium in the second step the selenide is oxidized with hydrogen peroxide to give a selenoxide this structure decomposes to form an alkene by an ei elimination mechanism with expulsion of a selenol in a fashion similar to that of the cope elimination this reaction takes part in the synthesis of ring c of the danishefsky taxol synthesis
the grieco three component condensation is an organic chemistry reaction that produces nitrogen containing six member heterocycles via a multi component reaction of an aldehyde an aniline and an electron rich alkene the reaction is catalyzed by trifluoroacetic acid or lewis acids such as ytterbium trifluoromethanesulfonate yb otf 3 the reaction is named for paul grieco who first reported it in 1985 the reaction process involves the formation of an aryl immonium ion intermediate followed by an aza diels alder reaction with an alkene imines are electron poor and thus usually function as the dienophile here however the alkene is electron rich so it reacts well with the immonium diene in an inverse electron demand diels – alder reaction researchers have extended the grieco three component reaction to reactants or catalysts immobilized on solid support which greatly expands the application of this reaction to various combinatorial chemistry settings kielyov and armstrong were the first to report a solid supported version of this reaction they found that this reaction works well for each reactants immobilized on solid support kobayashi and co workers show that a polymer supported scandium catalyst catalyze the grieco reaction with high efficiency given the effectiveness of the reaction and the commercial availability of various grieco partners the grieco three component coupling is very useful for preparing quinoline libraries for drug discovery
a grievance is a complaint raised by an employee which may be resolved by procedures provided for in a collective agreement an employment contract or by other mechanisms established by an employer such a grievance may arise from a violation of a collective bargaining agreement the terms of a contract the treatment by others in the workplace or violations of the law such as workplace safety regulations under uk employment law all employees have a legal right to raise a grievance and there is a statutory acas code of practice for handling grievances typically everyone involved with a grievance has strict time lines which must be met in the processing of this formal complaint until it is resolved employers cannot legally treat an employee any differently whether he or she has filed a grievance or not a collective grievance is a complaint raised by two or more employees in a unionized workplace under some jurisdictions it may also be known as a collective or labor dispute the difference between a grievance and a complaint in the unionized workplace is whether the subject matter relates to the collective bargaining agreement if the dispute cannot be resolved through discussion and negotiation between labor and management mediation arbitration or legal remedies may be employed where a collective dispute cannot be resolved it may lead to a strike action
the grignard reaction pronounced ɡriɲar is an organometallic chemical reaction in which alkyl vinyl or aryl magnesium halides grignard reagents add to a carbonyl group in an aldehyde or ketone this reaction is an important tool for the formation of carbon – carbon bonds the reaction of an organic halide with magnesium is not a grignard reaction but provides a grignard reagent an example of a grignard reaction grignard reactions and reagents were discovered by and are named after the french chemist françois auguste victor grignard university of nancy france who was awarded the 1912 nobel prize in chemistry for this work grignard reagents are similar to organolithium reagents because both are strong nucleophiles that can form new carbon – carbon bonds
a grill on a postage stamp is an embossed pattern of small indentations intended to discourage postage stamp reuse they were supposed to work by allowing the ink of the cancellation to be absorbed more readily by the fibres of the stamp paper making it harder to wash off the cancellation
in graph theory grinberg s theorem is a necessary condition for a planar graph to contain a hamiltonian cycle based on the lengths of its face cycles the result has been widely used to construct non hamiltonian planar graphs with further properties such as to give new counterexamples to tait s conjecture originally disproved by w t tutte in 1946 this theorem was proved by latvian mathematician emanuel grinberg in 1968
grinker s myelinopathy also known as anoxic leukoencephalopathy and delayed post hypoxic leukoencephalopathy dphl is a rare disease of the central nervous system grinker s myelinopathy was originally characterized by roy r grinker in 1925 or 1926 depending on the source the disease is characterized by a delayed leukoencephalopathy after an hypoxic episode it is typically though not necessarily related to carbon monoxide poisoning or heroin overdose it occurs in roughly 2 8 of those who experience an acute hypoxic anoxic episode because of the wide range of symptoms and the delay in onset it is often misdiagnosed as other neuropathologies
grinspan syndrome is a syndrome characterized by presence of the triad essential hypertension diabetes mellitus and oral lichen planus oral lichen planus is thought to be a result of the drugs used for treatment of hypertension and diabetes mellitus but this is not confirmed
griscelli syndrome is a rare autosomal recessive disorder characterized by albinism hypopigmentation with immunodeficiency that usually causes death by early childhood
griscelli syndrome type 2 also known as partial albinism with immunodeficiency is a rare autosomal recessive syndrome characterized by variable pigmentary dilution hair with silvery metallic sheen frequent pyogenic infections neutropenia and thrombocytopenia
griscelli syndrome type 3 is a disorder of melanosome transport presenting initially with hypopigmentation
grisi siknis in miskito language from the english means crazy sickness is a contagious culture bound syndrome that occurs predominantly among the miskito people of eastern central america and affects mainly young women it is also known as grisi munaia chipil siknis and nil siknis more recently cases occurring amongst people of spanish descent have also been reported
grit in psychology is a positive non cognitive trait based on an individual s passion for a particular long term goal or end state coupled with a powerful motivation to achieve their respective objective this perseverance of effort promotes the overcoming of obstacles or challenges that lie within a gritty individual s path to accomplishment and serves as a driving force in achievement realization commonly associated concepts within the field of psychology include perseverance hardiness resilience ambition need for achievement and conscientiousness these constructs can be conceptualized as individual differences related to the accomplishment of work rather than latent ability this distinction was brought into focus in 1907 when william james challenged the field to further investigate how certain individuals are capable of accessing richer trait reservoirs enabling them to accomplish more than the average person but the construct dates back at least to galton and the ideals of persistence and tenacity have been understood as a virtue at least since aristotle
in chemistry a grob fragmentation is an elimination reaction that breaks a neutral aliphatic chain into three fragments a positive ion spanning atoms 1 and 2 the electrofuge an unsaturated neutral fragment spanning positions 3 and 4 and a negative ion the nucleofuge comprising the rest of the chain for example the positive ion may be a carbenium carbonium or acylium ion the neutral fragment could be an alkene alkyne or imine and the negative fragment could be a tosyl or hydroxyl ion grob fragmentation the reaction is named for the swiss chemist cyril a grob
grocer s itch is a cutaneous condition characterized by a pruritic dermatitis that occurs from coming into contact with mites such as carpoglyphus passularum a fruit mite or glyciphagus domesticus a common house mite contact usually occurs when handling food with mites in it such as figs dates prunes grain cheese or other dried foods
the gronchi rosa is a rare italian postage stamp design error it was part of a 1961 issue for the voyage of president giovanni gronchi to three south american countries the 205 liras rosa was intended for the stopover in peru the artist made a mistake with the boundaries between peru and ecuador the rose colored stamp was quickly replaced by a grey version with corrected boundaries but some philatelic souvenirs using the gronchi rosa already existed a forgery of this stamp is known to exist
groom kidnapping colloquially known as pakaruah shaadi or jabaria shaadi is a phenomenon common in the western parts of bihar and eastern uttar pradesh states in india wherein eligible bachelors are abducted by the bride s family and later forcefully married to avoid heavy dowry costs considering the traditional regard for the marriage sacrament most such marriages are not annulled additionally the groom may suffer criminal charges under indian dowry law and end up fighting lengthy legal battles the practice started becoming noticeable towards the late 20 th century as dowry costs became prohibitive and organized gangs came forward to carry out the abductions in 2009 1224 kidnappings for marriage were reported in bihar carried out on behalf of the families of the brides
gross leasable area gla is the amount of floor space available to be rented in a commercial property specifically gross leasable area is the total floor area designed for tenant occupancy and exclusive use including any basements mezzanines or upper floors it is typically expressed in square metres although in some places such as the united states canada and the united kingdom the square foot is used it is measured from the center line of joint partitions and from outside wall faces that is gross leasable area is the area for which tenants pay rent and thus the area that produces income for the property owner for a property with only one tenant the measurements gross floor area gfa and gross leasable area gla are essentially equal the building owners and managers association has established a standard with american national standards institute ansi boma z 65 1 1996 for measuring floor area and calculating gross leasable area and loss factor
gross loan is the total amount of issued credits given to banks during the accounting period liquidity of the bank can be judged upon the amount of its gross loans liquidity of the credit institutions is directly related to the refinancing needs gross loan is the total amount of loans refinanced by credit institutions subject to the central bank the central bank as the lender of last resort provides loans credits to commercial banks and other credit institutions when the banks themselves have completely depleted their internal resources and are unable to maintain their solvency through other means the central bank gives loans to commercial banks at the refinancing interest rate which is minimal and may vary depending on the type of services the given bank provides
gross margin is the difference between revenue and cost of goods sold or cogs divided by revenue expressed as a percentage generally it is calculated as the selling price of an item less the cost of goods sold production or acquisition costs essentially gross margin is often used interchangeably with gross profit but the terms are different when speaking about a dollar amount it is technically correct to use the term gross profit when referring to a percentage or ratio it is correct to use gross margin in other words gross margin is a value while gross profit is a value gross margin is a type of profit margin specifically a form of profit divided by net revenue for example gross profit margin operating profit margin net profit margin etc
in accounting gross profit sales profit or credit sales is the difference between revenue and the cost of making a product or providing a service before deducting overheads payroll taxation and interest payments this is different from operating profit earnings before interest and taxes gross margin is the term normally used in the u s while gross profit is the more common usage in the uk and australia the various deductions and their corresponding metrics leading from net sales to net income are as follows net sales gross sales – customer discounts returns allowances gross profit net sales – cost of goods soldgross profit percentage net sales – cost of goods sold net sales × 100 operating profit gross profit – total operating expensesnet income or net profit operating profit – taxes – interest note cost of goods sold is calculated differently for a merchandising business than for a manufacturer
in chess a grotesque is a problem or endgame study which features a particularly unlikely initial position especially one in which white fights with a very small force against a much larger black army grotesques are generally intended to be humorous
in radiology ground glass opacity ggo is a nonspecific finding on computed tomography ct scans that indicates a partial filling of air spaces in the lungs by exudate or transudate as well as interstitial thickening or partial collapse of lung alveoli the similarity of shadows to a real ground glass is obvious
in electronic engineering ground bounce is a phenomenon associated with transistor switching where the gate voltage can appear to be less than the local ground potential causing the unstable operation of a logic gate
ground pressure is the pressure exerted on the ground by the tires or tracks of a motorized vehicle and is one measure of its potential mobility especially over soft ground it also applies to the feet of a walking person or machine ground pressure is measured in pascals pa which corresponds to the united states customary units unit of pounds per square inch psi average ground pressure can be calculated using the standard formula for average pressure p f a in an idealized case i e a static uniform net force normal to level ground at earth sea level this is simply the object s weight divided by contact area the ground pressure of motorized vehicles is often compared to the ground pressure of a human foot which can be 60 80 kpa while walking or as much as 13 mpa for a person in spike heels increasing the size of the contact area on the ground the footprint in relation to the weight decreases the ground pressure ground pressure of 14 kpa 2 psi or less is recommended for fragile ecosystems like marshes decreasing the ground pressure increases the flotation allowing easier passage of the body over soft terrain this is often observed in activities like snowshoeing
ground vibration boom is a phenomenon of very large increase in ground vibrations generated by high speed railway trains travelling at speeds higher than the velocity of rayleigh surface waves in the supporting ground
a group a streptococcal infection is an infection with group a streptococcus gas streptococcus pyogenes comprises the vast majority of the lancefield group a streptococci and is often used as a synonym for gas however s dysgalactiae can also be group a s pyogenes is a beta hemolytic species of gram positive bacteria that is responsible for a wide range of both invasive and noninvasive infections infection of gas may spread through direct contact with mucus or sores on the skin gas infections can cause 500 000 deaths per year despite the emergence of antibiotics as a treatment for group a β hemolytic streptococcus infection of gas is an increasing problem particularly on the continent of africa there are many other types of streptococci species of streptococcus including group b streptococcus streptococcus agalactiae and streptococcus pneumoniae which cause other types of infections and should not be confused with group a strep several virulence factors contribute to the pathogenesis of gas such as m protein hemolysins and extracellular enzymes
group b streptococcus infection is the infection caused by the bacterium streptococcus agalactiae s agalactiae also known as group b streptococcus or gbs group b streptococcal infection can cause serious illness and sometimes death especially in newborns the elderly and people with compromised immune systems gbs was recognized as a pathogen in cattle by edmond nocard and mollereau in the late 1880 s but its significance as a human pathogen was not discovered before 1938 when frydescribed three fatal cases of puerperal infections caused by gbs in the early 1960 s gbs was recognized as a main cause of neonatal infections in general gbs is a harmless commensal bacterium being part of the human microbiota colonizing the gastrointestinal and genitourinary tracts of up to 30 of healthy human adults asymptomatic carriers s agalactiae is also a common veterinary pathogen because it can cause bovine mastitis inflammation of the udder in dairy cows the species name agalactiae meaning no milk alludes to this s agalactiae is a gram positive coccus spherical bacterium with a tendency to form chains streptococcus beta haemolytic catalase negative and facultative anaerobe s agalactiae is the species designation for streptococci belonging to the group b of the rebecca lancefield classification of streptococci lancefield grouping gbs is surrounded by a bacterial capsule composed of polysaccharides exopolysaccharides gbs are subclassified into 10 serotypes ia ib ii – ix depending on the immunologic reactivity of their polysaccharide capsule as other virulent bacteria gbs harbours an important number of virulence factors the most important are the capsular polysaccharide rich in sialic acid and a pore forming toxin β haemolysin the gbs capsule is probably the key virulence factor because it helps gbs escape from the host defence mechanisms interfering with phagocytic killing of gbs by human phagocytes the gbs β haemolysin is considered identical to the gbs pigment
group dating is a modern pattern for dating where a group of single men and a group of single women organise a night out with the hope of forming romantic partnerships it is most popular in japan where it is known as gōkon in other cultures group dating is becoming more popular as a safe alternative to single dating especially blind dating also helping to ease tension because both parties will feel more comfortable having the company of their friends group dating is often recommended by parenting experts as more age appropriate form of dating for preteens than one on one dating
in abstract algebra a group isomorphism is a function between two groups that sets up a one to one correspondence between the elements of the groups in a way that respects the given group operations if there exists an isomorphism between two groups then the groups are called isomorphic from the standpoint of group theory isomorphic groups have the same properties and need not be distinguished
in abstract algebra the group isomorphism problem is the decision problem of determining whether two given finite group presentations present isomorphic groups the isomorphism problem was identified by max dehn in 1911 as one of three fundamental decision problems in group theory the other two being the word problem and the conjugacy problem all three problems are undecidable there does not exist a computer algorithm that correctly solves every instance of the isomorphism problem or of the other two problems regardless of how much time is allowed for the algorithm to run
groupshift is a phenomenon in which the initial positions of individual members of a group are exaggerated toward a more extreme position when people are in groups they make decisions about risk differently from when they are alone in the group they are likely to make riskier decisions as the shared risk makes the individual risk less
groupthink is a psychological phenomenon that occurs within a group of people in which the desire for harmony or conformity in the group results in an irrational or dysfunctional decision making outcome group members try to minimize conflict and reach a consensus decision without critical evaluation of alternative viewpoints by actively suppressing dissenting viewpoints and by isolating themselves from outside influences groupthink requires individuals to avoid raising controversial issues or alternative solutions and there is loss of individual creativity uniqueness and independent thinking the dysfunctional group dynamics of the ingroup produces an illusion of invulnerability an inflated certainty that the right decision has been made thus the ingroup significantly overrates its own abilities in decision making and significantly underrates the abilities of its opponents the outgroup furthermore groupthink can produce dehumanizing actions against the outgroup antecedent factors such as group cohesiveness faulty group structure and situational context e g community panic play into the likelihood of whether or not groupthink will impact the decision making process groupthink is a construct of social psychology but has an extensive reach and influences literature in the fields of communication studies political science management and organizational theory as well as important aspects of deviant religious cult behaviour groupthink is sometimes stated to occur more broadly within natural groups within the community for example to explain the lifelong different mindsets of conservatives versus liberals or the solitary nature of introverts however this conformity of viewpoints within a group does not mainly involve deliberate group decision making and might be better explained by the collective confirmation bias of the individual members of the group most of the initial research on groupthink was conducted by irving janis a research psychologist from yale university janis published an influential book in 1972 which was revised in 1982 janis used the bay of pigs disaster the failed invasion of castro s cuba in 1961 and the japanese attack on pearl harbor in 1941 as his two prime case studies have evaluated and reformulated his groupthink model
growing pains are pain symptoms relatively common in children ages 3 – 12 typically they are located in the muscles rather than the joints of the leg and less commonly the arm they are usually felt on both sides and appear late in the day or at night waking the child with pain varying from mild to very severe pain is absent by the morning and there are no objective clinical signs of inflammation pain can recur nightly or be absent for days to months growing pain is not associated with other serious disease and usually resolves by late childhood but frequent episodes are capable of having a substantial effect on the life of the child growing pains were first described as such in 1823 by a french doctor
growing teratoma syndrome is a rare complication of teratoma that can occur when an immature ovarian germ cell teratoma is treated by chemotherapy
the growth and underinvestment archetype is one of the common system archetype patterns defined as part of the system dynamics discipline system dynamics is an approach which strives to understand describe and optimize nonlinear behaviors of complex systems over time using tools such as feedback loops in order to find a leverage point of the system as part of this discipline several commonly found patterns of system behavior were found named and described in detail the growth and underinvestment archetype is one of such patterns
growth hormone deficiency ghd is a medical condition caused by problems arising in the pituitary gland in which the body does not produce enough growth hormone gh growth hormone also called somatropin is a polypeptide hormone which stimulates growth and cell reproduction growth hormone deficiency has a variety of different negative effects at different ages for example in newborn infants the primary manifestations may be hypoglycemia or micropenis while in later infancy and childhood growth failure is more likely deficiency in adults is rare but may feature diminished lean body mass poor bone density and a number of physical and psychological symptoms psychological symptoms include poor memory social withdrawal and depression while physical symptoms may include loss of strength stamina and musculature other hormonal or glandular disorders frequently coincide with diminished growth hormone production the most common cause of ghd representing two thirds of cases are pituitary and parasellar tumors the origin of adult ghd may be congenital or acquired of those adult ghd that are acquired roughly 15 are idiopathic 50 are from pituitary tumors 20 from extrapituitary tumors and 5 from infiltrative or inflammatory lesions gh deficiency can be treated through growth hormone replacement injections of growth hormone or radiation or surgical treatment of tumors
the term growth recession indicates a situation were growth is slow but not low enough to be a technical recession yet unemployment increases since more jobs are lost than created the term was created by dr solomon fabricant new york university national bureau of economic research and is recognized and cited more recently by business economists note that the term also has slightly different secondary meanings including a more general one that growth is below potential however the more specific meaning indicates the growth is weak and insufficient to provide jobs for those entering the labor market see the hoisington and hunt reference there may also be a third meaning referring to growth in which more jobs are actually being destroyed than created in all cases the term indicates real gdp is expanding slowly but with job contraction so the economy behaves or feels in many ways like a recession a former group managing director at global insight who is now at the bureau of economic analysis uses the phrase in this quote my feeling at the time 2002 2003 was we had a recession followed by a growth recession till 03 that ’ s what i showed on those global insight recession growth recession charts mike nemeira chief economist international council of shopping centers a better expert than i am and i debated this he thought there was an argument for a quick full recovery then a lapse into a growth recession there is no agreed standard for growth recession but i would say while it looked stronger for a couple quarters it wasn ’ t real strong soft landings tend to also be growth recessions but not always if economic growth in the economy is slowing to such a point that establishment payroll growth contracts then the soft landing is so soft it has crossed over into a growth recession both soft landings in the mid 1980 s and 1990 s qualify as for several months employment did contract two months in 1995 and one month in 1986 jobless recovery is another similar term all jobless recoveries are by definition also growth recessions however not all growth recessions are jobless recoveries because a growth recession can occur at any point in an economic cycle and a jobless recovery only refers to the period immediately after a recession ends
the grundmann aldehyde synthesis is a chemical reaction that produces an aldehyde from an acyl halide the grundmann aldehyde synthesis because of the rosenmund reduction and dibal h accomplish similar transformations this reaction sequence is not practiced much currently
grus is an accumulation of angular coarse grained fragments particles of sand and gravel resulting from the granular disintegration by the processes of chemical and mechanical weathering of crystalline rocks most notably granitoids generally in an arid or semiarid region grus sand when cemented into a sandstone will form an arkose
grynfeltt lesshaft hernia is a herniation of abdominal contents through the back specifically through the superior lumbar triangle which is defined by the quadratus lumborum muscle twelfth rib and internal oblique muscle
grøstl is a cryptographic hash function submitted to the nist hash function competition by praveen gauravaram lars knudsen krystian matusiewicz florian mendel christian rechberger martin schläffer and søren s thomsen grøstl was chosen as one of the five finalists of the competition it uses the same s box as aes in a custom construction the authors claim speeds of up to 21 4 cycles per byte on an intel core 2 duo according to the submission document the name grøstl is a multilingual play on words referring to an austrian dish that is very similar to hash food like other hash functions in the md 5 sha family grøstl divides the input into blocks and iteratively computes hi f hi − 1 mi however grøstl maintains a hash state at least twice the size of the final output 512 or 1024 bits which is only truncated at the end of hash computation the compression function f is based on a pair of 256 or 512 bit permutation functions p and q and is defined as f h m p h ⊕ m ⊕ q m ⊕ h the permutation functions p and q are heavily based on the rijndael aes block cipher but operate on 8 × 8 or 8 × 16 arrays of bytes rather than 4 × 4 like aes each round consists of four operations 1 addroundkey the grøstl round keys are fixed but differ between p and q 2 subbytes this uses the rijndael s box allowing sharing with aes implementations 3 shiftbytes expanded compared to aes this also differs between p and q and 512 and 1024 bit versions 4 mixcolumns using an 8 × 8 matrix rather than rijndael s 4 × 4 unlike rijndael all rounds are identical and there is no final addroundkey operation 10 rounds are recommended for the 512 bit permutation and 14 rounds for the 1024 bit version the final double width hash receives a final output transformation of ω h h ⊕ p h and is then truncated to the desired width this is equivalent to applying a final iteration of the compression function using an all zero message block m followed by a cryptographically insignificant exclusive or with the fixed constant q 0
guanidinoacetate methyltransferase deficiency also called gamt deficiency is an autosomal recessive metabolic disorder that primarily affects the nervous system and muscles it is the first observed disorder of creatine metabolism
in concurrent programming guarded suspension is a software design pattern for managing operations that require both a lock to be acquired and a precondition to be satisfied before the operation can be executed the guarded suspension pattern is typically applied to method calls in object oriented programs and involves suspending the method call and the calling thread until the precondition acting as a guard is satisfied
the guardian australia is the sydney based australian online presence of the british print newspaper the guardian it launched in 2013 led by katharine viner the australian site followed the earlier guardian us service which started in 2011 as of november 2014 it is in the top ten australian news media websites with a readership of just over 2 million australians per month contrasted to fairfax media s sydney morning herald website and the news ltd website news com au with readership of 3 8 and 3 7 million respectively
guardian us is the new york city based american online presence of the british print newspaper the guardian it launched in september 2011 led by editor in chief janine gibson and followed the earlier guardian america service which was wound up in 2009 guardian us is only available online although guardian weekly an international version of the guardian is available in print and online katharine viner is editor in chief of guardian us
a guelta or qalta or galta or agelmam from arabic قلتة which means a lower level of height in ground between rocks which holds water is a pocket of water that forms in drainage canals or wadis in the sahara the size and duration will depend on the location and conditions it may last year round through the dry season if fed by a source such as a spring when rivers wadis dry up there may remain pockets of water along its course c f ox bow lake in western sahara gueltas correspond with oases some examples include guelta d archei in chad and timia in niger
the guerbet reaction named after marcel guerbet 1861 – 1938 is an organic reaction converting a primary aliphatic alcohol into its β alkylated dimer alcohol with loss of one equivalent of water this reaction requires a catalyst and elevated temperatures guerbet reaction the original 1899 publication concerned the conversion of n butanol to 2 ethylhexanol the alcohols derived from this reaction are called guerbet alcohols application of long chained aliphatic alcohols gives access to surfactants the reaction requires alkali metal hydroxides or alkoxides and hydrogenation catalysts such as raney nickel at higher temperature 220 ° c and pressure
guided mode resonance or waveguide mode resonance is a phenomenon wherein the guided modes of an optical waveguide can be excited and simultaneously extracted by the introduction of a phase matching element such as a diffraction grating or prism such guided modes are also called leaky modes as they do not remain guided and have been observed in one and two dimensional photonic crystal slabs
guillain – barré syndrome gbs is a rapid onset muscle weakness caused by the immune system damaging the peripheral nervous system the initial symptoms are typically changes in sensation or pain along with muscle weakness beginning in the feet and hands this often spreads to the arms and upper body with both sides being involved the symptoms develop over hours to a few weeks during the acute phase the disorder can be life threatening with about 15 developing weakness of the breathing muscles requiring mechanical ventilation some are affected by changes in the function of the autonomic nervous system which can lead to dangerous abnormalities in heart rate and blood pressure the cause is unknown the underlying mechanism involves an autoimmune disorder in which the body s immune system mistakenly attacks the peripheral nerves and damages their myelin insulation sometimes this immune dysfunction is triggered by an infection or less commonly surgery or vaccination the diagnosis is usually made based on the signs and symptoms through the exclusion of alternative causes and supported by tests such as nerve conduction studies and examination of the cerebrospinal fluid there are a number of subtypes based on the areas of weakness results of nerve conduction studies and the presence of certain antibiodies it is classified as an acute polyneuropathy in those with severe weakness prompt treatment with intravenous immunoglobulins or plasmapheresis together with supportive care will lead to good recovery in the majority recovery may take weeks to years about a third have some permanent weakness globally death occurs in about 7 5 of those affected guillain – barré syndrome is rare at one or two cases per 100 000 people every year both sexes and all parts of the world have similar rates of disease the syndrome is named after the french neurologists georges guillain and jean alexandre barré who described it with andré strohl in 1916
the guillotine problem is a problem in combinatorial geometry and in printing closely related to packing problems and specifically to cutting stock and bin packing problems it is the question of how to get the maximum number of sheets of one rectangular size out of a larger sheet only orthogonal cuts that bisect one component of the sheet are allowed as on a paper cutting guillotine the guilottine problem is important in glass machining glass sheets are scored along horizontal and vertical lines and then broken along these lines to obtain smaller panels like the cutting stock problem it is np hard but various approximate and exact solutions have been devised
a guinier – preston zone or gp zone is a fine scale metallurgical phenomenon involving early stage precipitation gp zones are associated with the phenomenon of age hardening whereby room temperature reactions continue to occur within a material through time resulting in changing physical properties in particular this occurs in several aluminium series such as the 6000 and 7000 series alloys physically gp zones are extremely fine scaled on the order of 3 – 10 nm in size solute enriched regions of the material which offer physical obstructions to the motion of dislocations above that of the solid solution strengthening of the solute components in 7075 aluminium for example zn – mg clusters precede the formation of equilibrium mgzn 2 precipitates
gulf war syndrome gws also known as gulf war illnesses gwi is a chronic multisymptom disorder affecting returning military veterans and civilian workers of the 1990 – 91 gulf war a wide range of acute and chronic symptoms have been linked to it including fatigue muscle pain cognitive problems rashes and diarrhea approximately 250 000 of the 697 000 u s veterans who served in the 1991 gulf war are afflicted with enduring chronic multi symptom illness a condition with serious consequences from 1995 to 2005 the health of combat veterans worsened in comparison with nondeployed veterans with the onset of more new chronic diseases functional impairment repeated clinic visits and hospitalizations chronic fatigue syndrome like illness posttraumatic stress disorder and greater persistence of adverse health incidents according to a report by the iraq and afghanistan veterans of america veterans of iraq and afghanistan may also suffer from the syndrome suggested causes have included depleted uranium sarin gas smoke from burning oil wells vaccinations combat stress and psychological factors the u s department of veterans affairs va refers to the condition as gulf war veterans ’ medically unexplained illnesses the va states we prefer not to use the term gulf war syndrome when referring to medically unexplained symptoms reported by gulf war veterans why because symptoms vary widely
a gumma is a soft non cancerous growth resulting from the tertiary stage of syphilis it is a form of granuloma gummas are most commonly found in the liver gumma hepatis but can also be found in brain heart skin bone testis and other tissues leading to a variety of potential problems including neurological disorders or heart valve disease
gummy stem blight is a cucurbit rot disease caused by the fungal plant pathogen didymella bryoniae anamorph phoma cucurbitacearum gummy stem blight can affect a host at any stage of growth in its development and affects all parts of the host including leaves stems and fruits symptoms generally consist of circular dark tan lesions that blight the leaf water soaked leaves stem cankers and gummy brown ooze that exudes from cankers giving it the name gummy stem blight gummy stem blight reduces yields of edible cucurbits by devastating the vines and leaves and rotting the fruits there are various methods to control gummy stem blight including use of treated seed crop rotation using preventative fungicides eradication of diseased material and deep plowing previous debris
in a cellular automaton a gun is a pattern with a main part that repeats periodically like an oscillator and that also periodically emits spaceships there are then two periods that may be considered the period of the spaceship output and the period of the gun itself which is necessarily a multiple of the spaceship output s period a gun whose period is larger than the period of the output is a pseudoperiod gun in the game of life for every p greater than or equal to 14 it is possible to construct a glider gun in which the gliders are emitted with period p since guns continually emit spaceships the existence of guns in life means that initial patterns with finite numbers of cells can eventually lead to configurations with limitless numbers of cells something that john conway himself originally conjectured to be impossible however according to conway s later testimony this conjecture was explicitly intended to encourage someone to disprove it i e conway hoped that infinite growth patterns did exist bill gosper discovered the first glider gun in 1970 earning 50 from conway the discovery of the glider gun eventually led to the proof that conway s game of life could function as a turing machine for many years this glider gun was the smallest one known in life although other rules had smaller guns however in 2015 a period 120 gun in life with fewer live cells but a larger bounding box was discovered
gunther disease also known as congenital erythropoietic porphyria cep uroporphyrinogen iii synthase deficiency and uros deficiency is a congenital form of erythropoietic porphyria the word porphyria originated from the greek word porphura porphura actually means “ purple pigment ” which in suggestion the color that the body fluid changes when a person has gunther ’ s disease it is a rare autosomal recessive metabolic disorder affecting heme caused by deficiency of the enzyme uroporphyrinogen cosynthetase it is extremely rare with a prevalence estimated at 1 in 1 000 000 or less there have been times that prior to birth of a fetus gunther s disease has been shown to lead to anemia in milder cases patients have not presented any symptoms until they have reached adulthood in gunther s disease porphyrins are accumulated in the teeth and bones and an increased amount are seen in the plasma bone marrow feces red blood cells and urine
the gunz haslach interglacial german günz haslach interglazial also gunz haslach warm period günz haslach warmzeit is one of the warm periods of the pleistocene in the alpine region it lies between the gunz and haslach glaciations
guo jin min tui 国进民退 is a phenomenon in the chinese economy meaning the state advances the private sector retreats despite being less profitable the average return on equity is 4 state owned enterprises have easier access to funding than purely private enterprises the government has encouraged state owned enterprises to consolidate favoured them in regulation and awarded them contracts and subsidies this crowds out other competitors both domestic and foreign undermining the economy this contrasts with an earlier phase of economic liberalisation in china where the private sector was seen as flourishing and generating growth in the late 1990 s zhu rongji weeded out some of the weaker state owned enterprises however in some contexts guo jin min tui has been contrasted with guo jin min ye jin meaning the state and the market develop together six years ago the central government invited private investors to enter the business by 2006 eight private carriers had sprung up to challenge the three state controlled majors air china china southern and china eastern the state airlines immediately began a price war the state owned monopoly that provided jet fuel refused to service private carriers on the same generous terms given the big three china ’ s only computerized reservation system — currently one third owned by the three state airlines — refused to book flights for private competitors and when mismanagement and the 2008 economic crisis drove the three majors into financial straits the central government bought stock to bail them out
for alternative use see somerset gurgle gurgle com is a british pregnancy and parenting website owned by high street parenting store mothercare founded by tom wright gurgle launched as a joint venture between mothercare and fleming media a family backed investment company in october 2007 mothercare bought fleming media out to become outright owner of gurgle in september 2009 since 2008 the site has been run by pettrina keogh who joined the company from telegraph media group
gustatory hyperhidrosis is excessive sweating that certain individuals regularly experience on the forehead scalp upper lip perioral region or sternum a few moments after eating spicy foods tomato sauce chocolate coffee tea or hot soups this type of sweating is classified under focal hyperhidrosis that is it is restricted to certain regions of the body a common cause is the result of trauma or damage of the nerve that passes through the parotid gland this type of sweating is known as frey s syndrome in which case the damage to the nerve is due to surgery of the parotid gland parotidectomy it has been observed in diabetics with autonomic neuropathy and a variant of this disorder has been reported following surgical sympathectomy one of the more effective treatments is oral or topically applied glycopyrrolate
guttate psoriasis also known as eruptive psoriasis is a type of psoriasis that presents as small 0 5 – 1 5 cm in diameter lesions over the upper trunk and proximal extremities it is found frequently in young adults guttate psoriasis is classically triggered by a bacterial infection usually an upper respiratory tract infection for some people it starts as a throat infection or strep throat after the throat infection has cleared up the person can feel fine for several weeks before noticing the appearance of red spots they appear small at first like a dry red spot which is slightly itchy when scratched or picked the top layer of dry skin is removed leaving dry red skin beneath with white dry areas marking where flakes of dry skin stop and start in the weeks that follow the spots can grow to as much as an inch in diameter some of the larger ones may form a pale area in the center which is slightly yellow treatment is often a mild steroid such as hydrocortisone but this is not always effective other treatment include exposing the affected area of the skin to sunlight while avoiding sunburn the condition often but not always clears up on its own the guttate psoriasis can occur on any part of the body particularly the legs arms torso eyelids back bottom bikini line and neck generally the parts of the body most affected are seen on the arms legs back and torso enthusiastic exfoliation can lead to bleeding so care and moisturization are important to keep the affected skin healthy note it is commonly mistaken for measles
in common parlance guttural r is the phenomenon whereby a rhotic consonant an r like sound is produced in the back of the vocal tract usually with the uvula rather than in the front portion thereof and thus as a guttural consonant speakers of languages with guttural r typically regard guttural and coronal rhotics to be alternative pronunciations of the same phoneme despite articulatory differences similar consonants are found in other parts of the world but they often have little to no cultural association or interchangeability with coronal rhotics such as r ɾ and ɹ and guttural realization of a lone rhotic consonant is typical in most of what is now france french speaking belgium germany denmark and the southernmost parts of sweden and south western parts of norway it is also frequent in the netherlands dutch speaking belgium and switzerland it also occurs as the normal pronunciation of one of two rhotic phonemes usually replacing an older alveolar trill in most of portugal various parts of brazil and among minorities of other portuguese speaking regions
gyckel jyckel also known as spex on some university faculties not to be confused with the theatre form spex is short theatrical appearance performed at a gask a gyckel often involves a group of students singing a song or playing a play lasting no more than a few minutes there are several unwritten rules the most important one is that the jyckel must be written by the performers and be presented for the first time at the gask the gyckel should also be sarcastic sexistic or humoristic at a gask with members from different faculties it is usually expected that each faculty perform its own gyckel others may also report that they will be performing a gyckel to the toastmaster the toastmaster announced when the time has come for a certain group to perform their gyckel
gynecomastia is a common disorder of the endocrine system in which there is a non cancerous increase in the size of male breast tissue most adolescent boys up to 70 have some breast development during puberty newborn and adolescent males often experience temporary gynecomastia due to the influence of maternal hormones and hormonal changes during puberty respectively the development of gynecomastia is usually associated with benign pubertal changes in adolescent boys the condition is often a source of psychological distress however 75 of pubertal gynecomastia cases resolve within two years of onset without treatment in rare cases gynecomastia has been known to occur in association with certain disease states gynecomastia may be seen in individuals with klinefelter syndrome or certain cancers with disorders involving the endocrine system or metabolic dysfunction with the use of certain medications or in older males due to a natural decline in testosterone production disturbances in the endocrine system that lead to an increase in the ratio of estrogens androgens are thought to be responsible for the development of gynecomastia this may occur even if the levels of estrogens and androgens are both appropriate but the ratio is altered the disorder is usually diagnosed by a physician after a detailed history and physical examination conservative management of gynecomastia is often appropriate as the condition commonly resolves on its own medical treatment of gynecomastia that has persisted beyond two years is often ineffective medications such as aromatase inhibitors have been found to be effective in rare cases of gynecomastia from disorders such as aromatase excess syndrome or peutz – jeghers syndrome but surgical removal of the excess tissue is usually required
in mathematical logic gödel s β function is a function used to permit quantification over finite sequences of natural numbers in formal theories of arithmetic the β function is used in particular in showing that the class of arithmetically definable functions is closed under primitive recursion and therefore includes all primitive recursive functions
in mathematical logic a gödel numbering is a function that assigns to each symbol and well formed formula of some formal language a unique natural number called its gödel number the concept was used by kurt gödel for the proof of his incompleteness theorems a gödel numbering can be interpreted as an encoding in which a number is assigned to each symbol of a mathematical notation after which a sequence of natural numbers can then represent a sequence of symbols these sequences of natural numbers can again be represented by single natural numbers facilitating their manipulation in formal theories of arithmetic since the publishing of gödel s paper in 1931 the term gödel numbering or gödel code has been used to refer to more general assignments of natural numbers to mathematical objects
the h reflex or hoffmann s reflex is a reflectory reaction of muscles after electrical stimulation of sensory fibers ia afferents stemming from muscle spindles in their innervating nerves for example those located behind the knee the h reflex test is performed using an electric stimulator which gives usually a square wave current of short duration and small amplitude higher stimulations might involve alpha fibers causing an f wave compromising the results and an emg set to record the muscle response that response is usually a clear wave called h wave 28 35 ms after the stimulus not to be confused with an f wave an m wave an early response occurs 3 6 ms after the onset of stimulation the h and f waves are later responses as the stimulus increases the amplitude of the f wave increases only slightly and the h wave decreases and at supramaximal stimulus the h wave will disappear the m wave does the opposite of the h wave as the stimulus increases the m wave increases there is a point of minimal stimulus where the m wave is absent and the h wave is maximal h reflex is analogous to the mechanically induced spinal stretch reflex for example knee jerk reflex the primary difference between the h reflex and the spinal stretch reflex is that the h reflex bypasses the muscle spindle and therefore is a valuable tool in assessing modulation of monosynaptic reflex activity in the spinal cord although stretch reflex gives just qualitative information about muscle spindles and reflex arch activity if the purpose of the test to compare performances from different subjects h reflex should be used in that case in fact latencies ms and amplitudes mv of h wave can be compared h reflex amplitudes measured by emg are shown to decrease significantly with applied pressure such as massage and tapping to the cited muscle the amount of decrease seems to be dependent on the force of the pressure with higher pressures resulting in lower h reflex amplitudes h reflex levels return to baseline immediately after pressure is released except in high pressure cases which had baseline levels returned within the first 10 seconds after about 5 days in zero gravity for instance in orbit around earth the h reflex diminishes significantly it is generally assumed that this is due to a marked reduction in the excitability of the spinal cord in zero gravity once back on earth a marked recovery occurs during the first day but it can take up to 10 days to return to normal the h reflex was the first medical experiment completed on the international space station
hair an syndrome consists of hyperandrogenism ha insulin resistance ir and acanthosis nigricans an although it is a rare subset of polycystic ovary syndrome studies on patients with hair an played a key role in elucidating the pathogenesis of the former in particular although hair an results from two very different types of abnormalities blocking antibodies against the insulin receptor or genetically absent reduced insulin receptor number function patients with both types have high levels of androgens male hormones research on the two types of hair an demonstrated that patients with both forms of hair an had very high levels of insulin and critically that it was the high insulin that caused the elevation in androgens in other words regardless of how it comes about high levels of insulin lead to high levels of androgens this insight had important implications for the understanding of the more common form of polycystic ovarian syndrome and ultimately led to new treatments for it such as metformin
has 160 is a cryptographic hash function designed for use with the korean kcdsa digital signature algorithm it is derived from sha 1 with assorted changes intended to increase its security it produces a 160 bit output has 160 is used in the same way as sha 1 first it divides input in blocks of 512 bits each and pads the final block a digest function updates the intermediate hash value by processing the input blocks in turn the message digest algorithm consists of 80 rounds
has v is a cryptographic hash function with a variable output length has v is a hash function based on a block cipher the hash function can produce hash values with lengths from 16 to 40 bytes
haval is a cryptographic hash function unlike md 5 but like most modern cryptographic hash functions haval can produce hashes of different lengths haval can produce hashes in lengths of 128 bits 160 bits 192 bits 224 bits and 256 bits haval also allows users to specify the number of rounds 3 4 or 5 to be used to generate the hash haval was invented by yuliang zheng josef pieprzyk and jennifer seberry in 1992
hec syndrome is a syndrome characterized by hydrocephalus endocardial fibroelastosis and cataracts
hellp syndrome is a life threatening obstetric complication usually considered to be a variant or complication of pre eclampsia both conditions usually occur during the later stages of pregnancy or sometimes after childbirth hellp is an abbreviation of the three main features of the syndrome hemolysis elevated liver enzymes low platelet count
haemochromatosis or hemochromatosis type 1 also hfe hereditary haemochromatosis or hfe related hereditary haemochromatosis is a hereditary disease characterized by excessive intestinal absorption of dietary iron resulting in a pathological increase in total body iron stores humans like most animals have no means to excrete excess iron excess iron accumulates in tissues and organs disrupting their normal function the most susceptible organs include the liver adrenal glands heart skin gonads joints and the pancreas patients can present with cirrhosis polyarthropathy adrenal insufficiency heart failure or diabetes the hereditary form of the disease is most common among those of northern european ancestry in particular those of celtic descent the disease is inherited in an autosomal recessive pattern which means both copies of the gene in each cell have mutations most often the parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene but do not show signs and symptoms of the condition
hiv associated lipodystrophy is a condition characterized by loss of subcutaneous fat associated with infection with hiv
hiv associated nephropathy hivan refers to kidney disease developing in association with hiv infection the most common or classical type of hiv associated nephropathy is a collapsing focal segmental glomerulosclerosis fsgs though other forms of kidney disease may also occur with hiv regardless of the underlying histology renal disease in hiv positive patients is associated with an increased risk of death hivan may be caused by direct infection of the renal cells with the hiv 1 virus with resulting renal damage through the viral gene products it could also be caused by changes in the release of cytokines during hiv infection usually occurs only in advanced disease and approximately 80 of patients with hivan have a cd 4 count of less than 200 hivan presents with nephrotic syndrome and progressive kidney failure despite being a cause of chronic kidney failure kidney sizes are usually normal or large
hiv associated neurocognitive disorders hand are neurological disorders associated with hiv infection and aids hand may include neurological disorders of various severity such as aids dementia complex adc also known as hiv dementia and hiv associated dementia had hiv encephalopathy and mild neurocognitive disorder mnd hiv associated neurocognitive disorders are associated with a metabolic encephalopathy induced by hiv infection and fueled by immune activation of macrophages and microglia these cells are actively infected with hiv and secrete neurotoxins of both host and viral origin the essential features of adc are disabling cognitive impairment accompanied by motor dysfunction speech problems and behavioral change cognitive impairment is characterised by mental slowness trouble with memory and poor concentration motor symptoms include a loss of fine motor control leading to clumsiness poor balance and tremors behavioral changes may include apathy lethargy and diminished emotional responses and spontaneity histopathologically it is identified by the infiltration of monocytes and macrophages into the central nervous system cns gliosis pallor of myelin sheaths abnormalities of dendritic processes and neuronal loss adc typically occurs after years of hiv infection and is associated with low cd 4 t cell levels and high plasma viral loads it is sometimes seen as the first sign of the onset of aids prevalence is between 10 24 in western countries and has only been seen in 1 2 of india based infections with the advent of highly active antiretroviral therapy haart the incidence of adc has declined in developed countries although its prevalence is increasing haart may prevent or delay the onset of adc in people with hiv infection and may also improve mental function in people who already have adc dementia only exists when neurocognitive impairment in the patient is severe enough to interfere markedly with day to day function that is the patient is typically unable to work and may not be able to take care of him or herself before this the patient is said to have a mild neurocognitive disorder
hiv associated pruritus is a cutaneous condition an itchiness of the skin that occurs in up to 30 of hiv infected people occurs when the t cell count drops below 400 per cubic mm
human immunodeficiency virus infection and acquired immune deficiency syndrome hiv aids is a spectrum of conditions caused by infection with the human immunodeficiency virus hiv following initial infection a person may not notice any symptoms or may experience a brief period of influenza like illness typically this is followed by a prolonged period with no symptoms as the infection progresses it interferes more with the immune system increasing the risk of common infections like tuberculosis as well as other opportunistic infections and tumors that rarely affect people who have working immune systems these late symptoms of infection are referred to as aids this stage is often also associated with weight loss hiv is spread primarily by unprotected sex including anal and oral sex contaminated blood transfusions hypodermic needles and from mother to child during pregnancy delivery or breastfeeding some bodily fluids such as saliva and tears do not transmit hiv methods of prevention include safe sex needle exchange programs treating those who are infected and male circumcision disease in a baby can often be prevented by giving both the mother and child antiretroviral medication there is no cure or vaccine however antiretroviral treatment can slow the course of the disease and may lead to a near normal life expectancy treatment is recommended as soon as the diagnosis is made without treatment the average survival time after infection is 11 years in 2015 about 36 7 million people were living with hiv and it resulted in 1 1 million deaths most of those infected live in sub saharan africa between its discovery and 2014 aids has caused an estimated 39 million deaths worldwide hiv aids is considered a pandemic — a disease outbreak which is present over a large area and is actively spreading hiv is believed to have originated in west central africa during the late 19 th or early 20 th century aids was first recognized by the united states centers for disease control and prevention cdc in 1981 and its cause — hiv infection — was identified in the early part of the decade hiv aids has had a great impact on society both as an illness and as a source of discrimination the disease also has large economic impacts there are many misconceptions about hiv aids such as the belief that it can be transmitted by casual non sexual contact the disease has become subject to many controversies involving religion including the catholic church s decision not to support condom use as prevention it has attracted international medical and political attention as well as large scale funding since it was identified in the 1980 s
human immunodeficiency virus infection and acquired immune deficiency syndrome hiv aids is a disease spectrum of the human immune system caused by infection with human immunodeficiency virus hiv as the infection progresses it interferes more and more with the immune system making the person much more susceptible to common infections like tuberculosis as well as opportunistic infections and tumors that do not usually affect people who have working immune systems the late symptoms of the infection are referred to as aids this stage is often complicated by an infection of the lung known as pneumocystis pneumonia severe weight loss a type of cancer known as kaposi s sarcoma or other aids defining conditions genetic research indicates that hiv originated in west central africa during the late nineteenth or early twentieth century aids was first recognized by the united states centers for disease control and prevention cdc in 1981 and its cause — hiv infection — was identified in the early part of the decade since its discovery aids has caused an estimated 36 million deaths worldwide as of 2012 as of 2012 approximately 35 3 million people are living with hiv globally a team at the university of oxford united kingdom and the university of leuven in belgium tried to reconstruct hiv s family tree and find out where its oldest ancestors came from their 2014 study indicated that hiv aids pandemic originated in the democratic republic of congo as a result of social circumstances and the migration of workers
hiv disease related drug reactions present in hiv infected patients especially those with helper t cell counts between 25 and 200 immunosuppression that increases the risk for the development of adverse reactions to medications
hiv superinfection also called hiv reinfection is a condition in which a person with established human immunodeficiency virus infection acquires a second strain of the virus the hiv superinfection strain a recombinant strain appears when a person becomes infected by two different strains allowing dna to fuse and create a new one the second strain co exists with the first and may cause more rapid disease progression or carry resistance to certain hiv medication people with hiv risk superinfection by the same actions that would place a non infected person at risk of acquiring hiv these include sharing needles and forgoing condoms with hiv positive sexual partners for many years superinfection was thought to occur mainly in high risk populations research from uganda published in 2012 indicates that hiv superinfection among hiv infected individuals within a general population remains unknown further research from the journal of infectious diseases indicates that there have been 16 documented cases of superinfection since 2002
hms beatrice was a 98 ton displacement schooner launched in 1860 at newhaven she was acquired by the royal navy and the colony of south australia on 27 september 1862 and served on the australia station and was used as a survey ship and in this role she surveyed areas of the north coast of australia assisted the 1866 expedition of john mckinlay in the northern territory and surveyed the south australian coast in 1880 she was purchased outright by the colony of south australia where she was converted into a hulk in 1881 as a mooring marker for the mail steamers at glenelg later she was moved in 1888 to semaphore as a lightship she was sold in 1890 to private owners re rigged she was stranded near port lincoln on 4 february 1897 and after being refloating was rebuilt on a voyage to new owners on 14 july 1917 at hobart she encountered heavy weather and became stranded at tamar heads tasmania while transporting a load of timber from hobart for melbourne she was wrecked off the south eastern side of waterhouse island in bass strait on 9 april 1921 her crew was saved and her gear salvaged beatrice islets in nepean bay on kangaroo island are named after hms beatrice
hms elk was a 482 ton displacement 16 gun acorn class brig sloop of the royal navy launched on 29 september 1847 from the chatham dockyard she was sent to the east indies station and china station and participated during the second opium war until being assigned to the australia station in 1859 she searched for hms sappho with hmvs victoria after sappho disappeared in bass strait in february 1858 in 1860 she participated during the first taranaki war she left the australia station in march 1860 and upon arriving in england was paid off she was transferred to her majesty s coastguard in 1863 and was renamed wv 13 and she was later renamed wv 28 she was sold in may 1893
hms pelorus was a 2 330 ton displacement 21 gun corvette launched on 5 february 1857 from the devonport dockyard it was captained at first by frederick beauchamp paget seymour then by henry boys and later william henry haswell she participated as part of a squadron after the indian rebellion of 1857 then she was sent to the china station during the second opium war until may 1859 when she sailed for australian station in june 1860 as flagship of the australian squadron under captain frederick seymour she participated in the attack on puketakauere pā during the first taranaki war later that year the crew landed at kairau to support british troops under attack from maori and in january 1861 a gun crew from the ship helped defend the british redoubt at huirangi against the maori she left the australia station in july 1862 for plymouth the future admiral cyprian bridge served on pelorus in the east indies as a midshipman she was decommissioned in 1868 and was broken up for scrap in 1869
human papillomavirus hpv positive oropharyngeal cancer opc also known as hpv 16 oropharyngeal cancer or hpv opc is a recognized subtype of oropharyngeal squamous cell carcinomas oscc associated with the hpv type 16 virus
haber syndrome is a cutaneous disorder of hyperpigmentation characterized by reticulated pigmentation of the person s skin a rare genodermatosis its key features include rosacea like facial eruption reticulated hyperpigmentation of major flexures comedones on the back and neck and pitted facial scars
hadron spectroscopy is the subfield of particle physics that studies the masses and decays of hadrons hadron spectroscopy is also an important part of the new nuclear physics the properties of hadrons are a consequence of a theory called quantum chromodynamics qcd qcd predicts that quarks and antiquarks bind into particles called mesons another type of hadron is called a baryon that is made of three quarks there is good experimental evidence for both mesons and baryons potentially qcd also has bound states of just gluons called glueballs one of the goals of the field of hadronic spectroscopy is to find experimental evidence for exotic mesons tetraquarks molecules of hadrons and glueballs an important part of the field of hadronic spectroscopy are the attempts to solve qcd the properties of hadrons require the solution of qcd in the strong coupling regime where perturbative techniques based on feynman diagrams do not work there are several approaches to trying to solve qcd to compute the masses of hadrons quark models lattice qcd effective field theory sum rules
haemobilia is a medical condition of bleeding into the biliary tree haemobilia occurs when there is a fistula between a vessel of the splanchnic circulation and the intrahepatic or extrahepatic biliary system it can present as acute upper gastrointestinal ugi bleeding it should be considered in upper abdominal pain presenting with ugi bleeding especially when there is a history of liver injury or instrumentation first recorded in 1654 by francis glisson a cambridge professor
haemochromatosis type 3 is a type of iron overload disorder associated with deficiencies in transferrin receptor 2 it exhibits an autosomal recessive inheritance pattern
haemodialysis associated amyloidosis is a form of amyloidosis associated with chronic kidney failure
haemolacria is a physical condition that causes a person to produce tears that are partially composed of blood it can manifest as tears that are anything from merely red tinged to appearing to be entirely made of blood haemolacria is a symptom of a number of diseases and may also be indicative of a tumor in the lacrimal apparatus it is most often provoked by local factors such as bacterial conjunctivitis environmental damage or injuries acute haemolacria can occur in fertile women and seems to be induced by hormones similarly to what happens in endometriosis
haemophilia also spelled hemophilia is a mostly inherited genetic disorder that impairs the body s ability to make blood clots a process needed to stop bleeding this results in people bleeding longer after an injury easy bruising and an increased risk of bleeding inside joints or the brain those with mild disease may only have symptoms after an accident or during surgery bleeding into a joint can result in permanent damage while bleeding in the brain can result in long term headaches seizures or a decreased level of consciousness there are two main types of haemophilia haemophilia a which occurs due to not enough clotting factor viii and haemophilia b which occurs due to not enough clotting factor ix they are typically inheriting from one s parents an x chromosome with a nonfunctional gene rarely a new mutation may occur during early development or haemophilia may develop later in life due to antibodies forming against a clotting factor other types include haemophilia c which occurs due to not enough factor xi and parahaemophilia which occurs due to not enough factor v acquired haemophilia is associated with cancers autoimmune disorders and pregnancy diagnosis is by testing the blood for its ability to clot and its levels of clotting factors prevention may occur by removing a woman s egg fertilizing it and testing the embryo before putting it in the uterus treatment is by replacing the missing blood clotting factors this may be done on a regular basis or during bleeding episodes replacement may take place at home or in hospital the clotting factors are made either from human blood or by recombinant methods by up to 20 of people develop antibodies to the clotting factors which makes treatment more difficult the medication desmopressin may be used in those with mild haemophilia a studies of gene therapy are in early human trials haemophilia a affects about 1 in 5 000 – 10 000 while haemophilia b affects about 1 in 40 000 males at birth as haemophilia a and b are x linked recessive disorders females are very rarely severely affected some females with a nonfunctional gene on one of the x chromosomes may be mildly symptomatic haemophilia c occurs equally in both sexes and is mostly found in ashkenazi jews in the 1800 s haemophilia was common within the royal families of europe the difference between haemophilia a and b was determined in 1952 the word is from the greek haima αἷμα meaning blood and philia φιλία meaning love
haemophilia a is a genetic deficiency in clotting factor viii which causes increased bleeding and usually affects males in the majority of cases it is inherited as an x linked recessive trait though there are cases which arise from spontaneous mutations
haemophilia b or hemophilia b is a blood clotting disorder caused by a mutation of the factor ix gene leading to a deficiency of factor ix it is the second most common form of haemophilia rarer than haemophilia a haemophilia b was first recognized as a different kind of haemophilia in 1952 it is sometimes called christmas disease named after stephen christmas the first patient described with this disease in addition the first report of its identification was published in the christmas edition of the british medical journal
haemophilia c also known as plasma thromboplastin antecedent pta deficiency or rosenthal syndrome is a mild form of haemophilia affecting both sexes due to factor xi deficiency however it predominantly occurs in jewish people of ashkenazi descent it is the fourth most common coagulation disorder after von willebrand s disease and haemophilia a and b in the united states it is thought to affect 1 in 100 000 of the adult population making it 10 as common as haemophilia a
haemophilus influenzae cellulitis is a cutaneous condition characterized by a distinctive bluish or purplish red cellulitis of the face
haemophilus meningitis is a form of bacterial meningitis caused by the haemophilus influenzae bacteria it is usually but not always associated with haemophilus influenzae type b meningitis involves the inflammation of the protective membranes that cover the brain and spinal cord haemophilus meningitis is characterized by symptoms including fever nausea sensitivity to light headaches stiff neck anorexia and seizures haemophilus meningitis can be deadly but antibiotics are effective in treating the infection especially when cases are caught early enough that the inflammation has not done a great deal of damage before the introduction of the hib vaccine in 1985 haemophilus meningitis was the leading cause of bacterial meningitis in children under the age of five however since the creation of the hib vaccine only two in every 100 000 children contract this type of meningitis five to ten percent of cases can be fatal although the average mortality rate in developing nations is seventeen percent mostly due to lack of access to vaccination as well as lack of access to medical care needed to combat the meningitis
haemorrhagic disease of the newborn also known as vitamin k deficiency bleeding vkdb is a coagulation disturbance in newborn infants due to vitamin k deficiency as a consequence of vitamin k deficiency there is an impaired production of coagulation factors ii vii ix x protein c and protein s by the liver resulting in excessive bleeding hemorrhage
haff disease german haffkrankheit is the development of rhabdomyolysis swelling and breakdown of skeletal muscle with a risk of acute kidney failure within 24 hours of ingesting fish
hagemoser – weinstein – bresnick syndrome is an autosomal dominant genetic disorder first described by hagemoser et al in 1989 it is characterized by optic atrophy followed shortly by loss of hearing and peripheral neuropathy onset of the disease occurred in early childhood as opposed to the later onset of similar diseases optic atrophy occurs in the first year and the following symptoms show up before thirteen years a possible autosomal recessive form of this disease was described in 1970 by iwashita et al
haglund ’ s deformity aka the mulhulland deformity is a bony enlargement on the back of the heel that most often leads to painful bursitis which is an inflammation of the bursa a fluid filled sac between the tendon and bone in haglund ’ s deformity the soft tissue near the achilles tendon becomes irritated when the bony enlargement rubs against shoes haglund ’ s deformity is often called “ pump bump ” because the rigid backs of pump style shoes can create pressure that aggravates the enlargement when walking
haidinger s brush is an entoptic phenomenon first described by austrianphysicist wilhelm karl von haidinger in 1844 many people are able to perceive polarization of light it may be seen as a yellowish horizontal bar or bow tie shape with fuzzy ends hence the name brush visible in the center of the visual field against the blue sky viewed while facing away from the sun or on any bright background it typically occupies roughly 3 – 5 degrees of vision about twice or three times the width of one s thumb held at arm s length the direction of light polarization is perpendicular to the yellow bar i e vertical if the bar is horizontal fainter bluish or purplish areas may be visible between the yellow brushes see illustration haidinger s brush may also be seen by looking at a white area on many lcd flat panel computer screens due to the polarization effect of the display in which case it is often diagonal
hailey – hailey disease or familial benign chronic pemphigus or familial benign pemphigus was originally described by the hailey brothers hugh edward and william howard in 1939 it is a genetic disorder that causes blisters to form on the skin
haim – munk syndrome also known as palmoplantar keratoderma with periodontitis and arachnodactyly and acro osteolysis is a cutaneous condition caused by a mutation in the cathepsin c gene it was named after dr salim haim and dr munk l
hair diseases are disorders primarily associated with the follicles of the hair an example is hypertrichosis many hair diseases can be associated with distinct underlying disorders piedra are fungal diseases hair disease may refer to excessive shedding or baldness or both balding can be localised or diffuse scarring or non scarring increased hair can be due to hormonal factors hirsutism or non hormonal hypertrichosis scalp disorders may or may not be associated with hair loss
hair follicle nevus also known as a vellus hamartoma is a cutaneous condition that presents as a small papule from which fine hairs protrude evenly from the surface
hair loss also known as alopecia or baldness refers to a loss of hair from part of the head or body typically at least the head is involved the severity of hair loss can vary from a small area to the entire body typically inflammation or scarring is not present hair loss in some people causes psychological distress common types include male pattern hair loss female pattern hair loss alopecia areata and a thinning of hair known as telogen effluvium the cause of male pattern hair loss is a combination of genetics and male hormones the cause of female pattern hair loss is unclear the cause of alopecia areata is autoimmune and the cause of is telogen effluvium is typically a physically or psychologically stressful event telogen effluvium is very common following pregnancy less common causes of hair loss without inflammation or scarring include the pulling out of hair certain medications including chemotherapy hiv aids hypothyroidism and malnutrition including iron deficiency causes of hair loss that occurs with scarring or inflammation include fungal infection lupus erythematosus radiation therapy and sarcoidosis diagnosis of hair loss is partly based on the areas affected treatment of pattern hair loss may simply involve accepting the condition intervention that can be tried include the medications minoxidil or finasteride and hair transplant surgery alopecia areata may be treated by steroid injections in the affected area but these need to be frequently repeated to be affective hair loss is a common problem pattern hair loss by age 50 affects about half of males and a quarter of females about 2 of people develop alopecia areata at some point in time
hair tourniquet is a medical condition wherein a hair or other thread becomes tied around a toe or finger tightly so as to put the digit at risk of damage occasionally this is known as toe tourniquet the problem usually arises in babies and small children when hairs and thread are lost loosely inside socks they can become spontaneously tied round a toe and will tend to tighten with wriggling natural hair is much more likely to undergo this phenomenon than spun thread incidents similar to this can also occur during sleep usually under duvets or sheets which have loose threads which can constrict the toes
in finance a haircut is the difference between the market value of an asset used as loan collateral and the amount of the loan the amount of the haircut reflects the lender s perceived risk of loss from the asset falling in value or being sold in a fire sale the lender will however still hold a lien for the entire value of the asset in the event the collateral is sold to repay the loan the lender will have a higher chance of being made whole expressed as a percentage of the collateral s market value the haircut is the complement of the loan to value ratio together they equal 100 of the value for example united states treasury bills which are seen as fairly safe might have a haircut of 10 while for stock options which are seen as highly risky the haircut might be as high as 30 in other words a 1000 treasury bill will be accepted as collateral for a 900 loan while a 1000 stock option might only allow a 700 loan lower haircuts allow for more leverage haircut plays an important role in many kinds of trades such as repurchase agreements referred to in debt instrument finance as repo but not to be confused with the concept of repossession denoted by that term in consumer finance and reverse repurchase agreements reverse repo in debt instrument finance in popular media haircut has been used to denote a financial loss on an investment as in to take a haircut to accept or receive less than is owed especially following the financial crisis of 2008 the term was popular in political debates surrounding the propriety of various government actions in response to the crisis
hairy cell leukemia is an uncommon hematological malignancy characterized by an accumulation of abnormal b lymphocytes it is usually classified as a sub type of chronic lymphoid leukemia hairy cell leukemia makes up approximately 2 of all leukemias with fewer than 2 000 new cases diagnosed annually in north america and western europe combined hairy cell leukemia was originally described as histiocytic leukemia malignant reticulosis or lymphoid myelofibrosis in publications dating back to the 1920 s the disease was formally named leukemic reticuloendotheliosis and its characterization significantly advanced by bertha bouroncle and colleagues at the ohio state university college of medicine in 1958 its common name which was coined in 1966 is derived from the hairy appearance of the malignant b cells under a microscope
hairy leukoplakia also known as oral hairy leukoplakia ohl or hiv associated hairy leukoplakia is a white patch on the side of the tongue with a corrugated or hairy appearance it is caused by epstein barr virus ebv and occurs usually in persons who are immunocompromised especially those with human immunodeficiency virus infection acquired immunodeficiency syndrome hiv aids this white lesion cannot be scraped off the lesion itself is benign and does not require any treatment although its appearance may have diagnostic and prognostic implications for the underlying condition depending upon what definition of leukoplakia is used hairy leukoplakia is sometimes considered a subtype of leukoplakia or a distinct diagnosis
hajdu – cheney syndrome also called acroosteolysis with osteoporosis and changes in skull and mandible arthrodentoosteodysplasia and cheney syndrome is an extremely rare autosomal dominant congenital disorder of the connective tissue characterized by severe and excessive bone resorption leading to osteoporosis and a wide range of other possible symptoms mutations in the notch 2 gene identified in 2011 cause hcs hcs is so rare that only about 70 cases have been reported worldwide since the discovery of the syndrome in 1948
the hajos – parrish – eder – sauer – wiechert reaction in organic chemistry is a proline catalysed asymmetric aldol reaction the reaction is named after its principal investigators zoltan hajos others from hoffmann la roche and schering ag discovered in the 1970 s the original hajos parrish catalytic procedure shown in the reaction equation leading to the optically active bicyclic ketol as well as the eder sauer wiechert modification leading to the optically active enedione through the loss of water from the ketol paved the way of asymmetric organocatalysis it has been used extensively as a tool in the synthesis of steroids and other enantiomerically pure molecules figure 1 in the original reaction shown in figure 1 naturally occurring chiral proline is the chiral catalyst in an aldol reaction the starting material is an achiral triketone and it requires just 3 of proline to obtain the reaction product a ketol in 93 enantiomeric excess as shown above hajos and parrish worked at ambient temperature in dimethylformamide dmf solvent using a catalytic amount 3 molar equiv of s − proline enabling them to isolate the optically active intermediate bicyclic ketol thus they described the first use of proline in a catalytic asymmetric aldol reaction the schering group worked under non biological conditions using s proline 47 mol 1 n perchloric acid in acetonitrile at 80 ° c hence they could not isolate the hajos parrish intermediate bicyclic ketol but instead the condensation product 7 as 7 a methyl 2 3 6 7 tetrahdroindol 1 5 dione through the loss of water thirty seven years later a new group at schering ag published the continuation of the earlier schering work 3 instead of the aforementioned non biological conditions the new group used the hajos parrish catalytic procedure thus they could isolate the optically active 6 5 bicyclic ketol described so far only in the hajos parrish publications 1 2 hajos and parrish investigated further the exact configuration of the above cis fused 7 a methyl 6 5 bicyclic ketol by circular dichroism and these results were confirmed by a single crystal x ray diffraction study the centro symmetrical crystal of the corresponding racemic ketol without a heavy atom label has been obtained by the use of racemic proline it showed by x ray diffraction an axial orientation of the angular methyl group and an equatorial orientation of the hydroxyl group in the chair conformer of the six membered ring this is in good agreement with the crystal structure of the cd ring of digitoxigenin the structure of this ketol and its ethyl homologue are shown as follows hajos parrish ketols similar studies of the 7 a ethyl homologue showed that the ethyl bicycic ketol existed in a cis conformation in which the 7 a ethyl group is equatorially oriented and the hydroxyl group is axially oriented in the chair form of the six membered ring as shown above the reason for a preference for this conformation could be enhanced 1 3 diaxial interaction in the other cis conformer between the angular ethyl group and the axial hydrogens at c 4 and c 6 in the six membered ring in a 2000 study the barbas group found that intermolecular aldol additions those between ketones and aldehydes are also possible albeit with use of considerably more proline aldol barbas 2000 the authors noted the similarity of proline the aldolase antibodies they had created and natural aldolase enzymes aldolase a all of which operate through an enamine intermediate in this reaction the large concentration of acetone one of the two reactants suppresses various possible side reactions reaction of the ketone with proline to an oxazolidinone and reaction of the aldehyde with proline to an azomethine ylide notz and list went on to expand the utility of this reaction to the synthesis of 1 2 diols synthesis of diols notz 2000 in their full account of their 2000 communication the group revealed that proline together with the thiazolium salt 5 5 dimethyl thiazolidinium 4 carboxylate were found to be the most effective catalysts among a large group of amines while catalysis with s 1 2 pyrrolidinylmethyl pyrrolidine salts formed the basis for the development of diamine organocatalysts that have proven effective in a wide variety or organocatalytic reactions the asymmetric synthesis of the wieland miescher ketone 1985 is another intramolecular reaction also based on proline that was explored by the barbas group in 2000 in this study the barbas group demonstrated for the first time that proline can catalyze the cascade michael aldol reaction through combined iminium enamine catalysis this work is significant because despite the 30 year history and application of the hajos parrish reaction in industry the triketone substrate for this reaction had always been synthesized in a discrete independent step demonstrating that there was a fundamental lack of understanding of the chemical mechanism of this reaction the barbas group had reported the aldolase antibody catalyzed iminium enamine robinson annulation in their 1997 study that marked the beginning of their studies in the area now called organocatalysis in a report published in 2002 carlos f barbas iii said work in the 1970 s on proline catalyzed intramolecular aldol addition reactions by synthetic organic chemists zoltan g hajos and david r parrish of the chemical research department at hoffmann la roche nutley n j inspired us to look more closely at parallels between small molecule catalysts and enzymes in 2002 the macmillan group was the first to demonstrate the proline catalyzed aldol reaction between different aldehydes this reaction is unusual because in general aldehydes will self condense aldol macmillan 2002 the organocatalytic intermolecular aldol reaction is now known as the barbas list aldol reaction
halal syndrome is a rare disorder characterised by microcephaly cleft palate and variable other anomalies
the half life of knowledge is the amount of time that has to elapse before half of the knowledge in a particular area is superseded or shown to be untrue the concept is attributed to fritz machlup 1962 for example donald hebb estimated the half life of psychology to be five years the half life of knowledge differs from the concept of half life in physics in that there is no guarantee that the truth of knowledge in a particular area of study is declining exponentially it is unclear that there is any way to establish what constitutes knowledge in a particular area as opposed to mere opinion or theory this is similar to the concept of a half life of facts coined by samuel arbesman a harvard mathematician and scholar at the kaufmann foundation because scientific knowledge is growing by a factor of ten every 50 years this means that half of what scientists may have known about a particular subject will be wrong or obsolete in 45 years
halitosis colloquially called bad breath or fetor oris is a symptom in which a noticeably unpleasant odor is present on the exhaled breath concern about halitosis is estimated to be the third most frequent reason for people to seek dental care following tooth decay and gum disease and about 20 of the general population are reported to suffer from it to some degree not all who think they have halitosis have a genuine problem of those who feel they have halitosis significant percentages 5 – 72 have been reported to have no genuine halitosis when professionally examined of those who have genuine halitosis often the odor is caused by bacteria present below the gumline and on the back of the tongue the remaining 10 is accounted for by many conditions including disorders in the nasal cavity sinuses throat lungs esophagus stomach or elsewhere see the related article on tonsilloliths for another possible cause of halitosis very rarely halitosis can be one of many symptoms of a serious underlying medical condition such as liver failure but in the vast majority of cases the cause is minor and can often be reduced by adjustments to oral hygiene including brushing or gently scraping the back of the tongue and improving the health of the gums by using dental floss occasionally however especially if the origin of the odor is not in the mouth halitosis can be more difficult to diagnose and to manage successfully bad breath is a social taboo and as a result perceived or genuine halitosis can sometimes trigger social anxiety
hallermann – streiff syndrome also known as oculomandibulofacial syndrome françois dyscephalic syndrome hallermann – streiff – françois syndrome oculomandibulodyscephaly with hypotrichosis aubry syndrome and ullrich fremery dohna syndrome is a congenital disorder that affects growth cranial development hair growth and dental development there are fewer than 200 people with the syndrome worldwide an organization supporting people with the hallermann – streiff syndrome is the germany based schattenkinder e v
a hallucination is a perception in the absence of external stimulus that has qualities of real perception hallucinations are vivid substantial and are perceived to be located in external objective space they are distinguishable from these related phenomena dreaming which does not involve wakefulness illusion which involves distorted or misinterpreted real perception imagery which does not mimic real perception and is under voluntary control and pseudohallucination which does not mimic real perception but is not under voluntary control hallucinations also differ from delusional perceptions in which a correctly sensed and interpreted stimulus i e a real perception is given some additional and typically absurd significance hallucinations can occur in any sensory modality — visual auditory olfactory gustatory tactile proprioceptive equilibrioceptive nociceptive thermoceptive and chronoceptive a mild form of hallucination is known as a disturbance and can occur in most of the senses above these may be things like seeing movement in peripheral vision or hearing faint noises and or voices auditory hallucinations are very common in schizophrenia they may be benevolent telling the subject good things about themselves or malicious cursing the subject etc auditory hallucinations of the malicious type are frequently heard for example people talking about the subject behind his her back like auditory hallucinations the source of the visual counterpart can also be behind the subject s back their visual counterpart is the feeling of being looked or stared at usually with malicious intent frequently auditory hallucinations and their visual counterpart are experienced by the subject together hypnagogic hallucinations and hypnopompic hallucinations are considered normal phenomena hypnagogic hallucinations can occur as one is falling asleep and hypnopompic hallucinations occur when one is waking up hallucinations can be associated with drug use particularly deliriants sleep deprivation psychosis neurological disorders and delirium tremens the word hallucination itself was introduced into the english language by the 17 th century physician sir thomas browne in 1646 from the derivation of the latin word alucinari meaning to wander in the mind
hallucinatory palinopsia greek palin for again and opsia for seeing is a subtype of palinopsia a visual disturbance defined as the persistent or recurrence of a visual image after the stimulus has been removed palinopsia is a broad term describing a heterogeneous group of symptoms which is divided into hallucinatory palinopsia and illusory palinopsia hallucinatory palinopsia refers to the projection of an already encoded visual memory and is similar to a complex visual hallucination the creation of a formed visual image where none exists hallucinatory palinopsia usually arises from posterior cortical lesions or seizures and can be the presenting symptom of a serious neurological disease hallucinatory palinopsia describes afterimages or scenes that are formed long lasting high resolution and isochromatic the palinoptic images are not typically reliant on environmental parameters and often present with homonymous visual field deficits hallucinatory palinopsia occurs unpredictably and the persistent images can appear anywhere in the visual field regardless of the location of the original stimulus a patient will often have only a few episodes of hallucinatory palinopsia visual perseveration is synonymous with palinopsia
hallucinogen persisting perception disorder hppd is a disorder characterized by a continual presence of sensory disturbances most commonly visual that are reminiscent of those generated by the use of hallucinogenic substances previous use of hallucinogens by the person is necessary but not sufficient for diagnosis of hppd for an individual to be diagnosed with hppd the symptoms cannot be due to another medical condition hppd is distinct from flashbacks by reason of its relative permanence while flashbacks are transient hppd is persistent hppd is a dsm iv diagnosis with diagnostic code 292 89
hallux rigidus or stiff big toe is degenerative arthritis and stiffness due to bone spurs that affects the mtp joint at the base of the hallux big toe hallux flexus was initially described by davies colley in 1887 as a plantar flexed posture of phalanx relative to the metatarsal head about the same time cotterill first used the term hallux rigidus
hallux varus is a deformity of the great toe joint where the hallux is deviated medially towards the midline of the body away from the first metatarsal bone the hallux usually moves in the transverse plane unlike hallux valgus hallux varus is uncommon in the west but it is common in cultures where the population remains unshod
halo from greek ἅλως halōs is the name for a family of optical phenomena produced by light interacting with ice crystals suspended in the atmosphere halos can have many forms ranging from colored or white rings to arcs and spots in the sky many of these are near the sun or moon but others occur elsewhere or even in the opposite part of the sky among the best known halo types are the circular halo properly called the 22 ° halo light pillars and sun dogs but there are many more some of them fairly common others extremely rare the ice crystals responsible for halos are typically suspended in cirrus or cirrostratus clouds high 5 – 10 km or 3 – 6 miles in the upper troposphere but in cold weather they can also float near the ground in which case they are referred to as diamond dust the particular shape and orientation of the crystals are responsible for the type of halo observed light is reflected and refracted by the ice crystals and may split up into colors because of dispersion the crystals behave like prisms and mirrors refracting and reflecting light between their faces sending shafts of light in particular directions atmospheric phenomena such as halos were used as part of weather lore as an empirical means of weather forecasting before meteorology was developed they often do mean that rain is going to fall within the next 24 hours as the cirrostratus clouds that cause them can signify an approaching frontal system other common optical phenomena involving water droplets rather than ice crystals include theglory and the rainbow
halo blight of bean is a bacterial disease caused by pseudomonas syringae pv phaseolicola halo blight ’ s pathogen is a gram negative aerobic polar flagellated and non spore forming bacteria this bacterial disease was first discovered in the early 1920 s and rapidly became the major disease of beans throughout the world the disease favors the places where temperatures are moderate and plentiful inoculum is available
halo nevus also known as leukoderma acquisitum centrifugum perinevoid vitiligo and sutton nevus is a mole that is surrounded by a depigmented ring or halo
in radiology the halo sign is a finding of a dark halo around the arterial lumen on ultrasound that suggests the diagnosis of temporal arteritis the standard diagnostic test for temporal arteritis is biopsy however ultrasound and mri show promise for replacing it the halo sign of temporal arteritis should not be confused with deuel s halo sign which is a sign of fetal death the halo sign is also understood as a region of ground glass attenuation surrounding a pulmonary nodule on an x ray computed tomography ct scan of the chest it can be associated with hemorrhagic nodules tumors or inflammatory processes but is most commonly known as an early radiographic sign of invasive pulmonary infection by the fungus species aspergillus in nursing the halo sign is the result of a test to see if drainage from a head injury contains cerebrospinal fluid when a dextrostix or tes tape test gives a positive reading for glucose the drainage must be further tested because glucose is also found in the blood to perform the test the leaking fluid is dripped onto a 4 x 4 gauze or towel the blood should coalesce into the center leaving a ring if cerebrospinal fluid is present
in oceanography a halocline from greek hals halo ‘ salt ’ and klinein ‘ to slope ’ is a subtype of chemocline caused by a strong vertical salinity gradient within a body of water because salinity in concert with temperature affects the density of seawater it can play a role in its vertical stratification increasing salinity by one kg m 3 results in an increase of seawater density of around 0 7 kg m 3 in the midlatitudes an excess of evaporation over precipitation leads to surface waters being saltier than deep waters in such regions the vertical stratification is due to surface waters being warmer than deep waters and the halocline is destabilizing such regions may be prone to salt fingering a process which results in the preferential mixing of salinity in certain high latitude regions such as the arctic ocean bering sea and the southern ocean the surface waters are actually colder than the deep waters and the halocline is responsible for maintaining water column stability isolating the surface waters from the deep waters in these regions the halocline is important in allowing for the formation of sea ice and limiting the escape of carbon dioxide to the atmosphere haloclines are also found in fjords and poorly mixed estuaries where fresh water is deposited at the ocean surface
the haloform reaction is a chemical reaction where a haloform chx 3 where x is a halogen is produced by the exhaustive halogenation of a methyl ketone a molecule containing the r – co – ch 3 group in the presence of a base r may be alkyl or aryl the reaction can be used to produce chloroform chcl 3 bromoform chbr 3 or iodoform chi 3 haloform reaction scheme
halogen acne is caused by iodides bromides and fluorides halogens that induce an acneiform eruption similar to that observed with steroids
a halogen addition reaction is a simple organic reaction where a halogen molecule is added to the carbon – carbon double bond of an alkene functional group the general chemical formula of the halogen addition reaction is c c x 2 → x − c − c − x x represents the halogens bromine or chlorine and in this case a solvent could be ch 2 cl 2 or ccl 4 the product is a vicinal dihalide this type of reaction is a halogenation and an electrophilic addition
the halogen dance rearrangement is an organic reaction in which a halogen substituent moves to a new position on an aromatic ring system the reaction belongs to a class of organic reactions called 1 2 rearrangements the original halogen dance is the base catalysed rearrangement of 1 2 4 tribromobenzene to 1 3 5 tribromobenzene in liquid ammonia with the aniline potassium base system the intermediate in this reaction is an aryl carbanion the halogen dance concept can be extended from benzene derivatives to other aromatic systems as well for instance furan and thiophenecompounds the halogen dance rearrangement of iodooxazoles was studied by the stambuli group
halogenation is a chemical reaction that involves the addition of one or more halogens to a compound or material dehalogenation is the reverse of halogenation and results in the removal of a halogen from a molecule the pathway and stoichiometry of halogenation depends on the structural features and functional groups of the organic substrate as well as on the specific halogen inorganic compounds such as metals also undergo halogenation
halogenodermas are skin eruptions that result after exposure to halogen containing drugs or substances this may last several weeks after drug use is discontinued this is because of the slow elimination rate of iodides and bromides fluoroderma is a particular type of halogenoderma which is caused by fluoride fluoride is present in oral hygiene products such as toothpastes and mouth washes hence this type of acne is seen mostly around the mouth and jawline acute fluoroderma has been observed in patients exposed to anaesthetics containing fluoride such as sevoflurane
in computability theory the halting problem is the problem of determining from a description of an arbitrary computer program and an input whether the program will finish running or continue to run forever alan turing proved in 1936 that a general algorithm to solve the halting problem for all possible program input pairs cannot exist a key part of the proof was a mathematical definition of a computer and program which became known as a turing machine the halting problem is undecidable over turing machines it is one of the first examples of a decision problem jack copeland 2004 attributes the term halting problem to martin davis
haltlos is a german word which means drifting aimless irresponsible
a hamartia is a focal malformation consisting of disorganized arrangement of tissue types that are normally present in the anatomical area a hamartia is not considered to be a tumor and is distinct from a hamartoma which describes a benign neoplasm characterized by tissue misarrangement similar to a hamartia i e tissue types that are typical of the area but arranged in an atypical manner
a hamartoma is a benign focal malformation that resembles a neoplasm in the tissue of its origin this is not a malignant tumor and it grows at the same rate as the surrounding tissues it is composed of tissue elements normally found at that site but which are growing in a disorganized mass they occur in many different parts of the body and are most often asymptomatic and undetected unless seen on an image taken for another reason incidentaloma additionally the definition of hamartoma versus benign neoplasm is often unclear since both lesions can be clonal lesions such as hemangiomas lymphangiomas rhabdomyomas adenomas and developmental cysts within the kidneys lungs or pancreas are interpreted by some experts as hamartomas while others consider them true neoplasms moreover even though hamartomas show a benign histology it does not eliminate some rare but life threatening clinical issues such as those found in tuberous sclerosis and neurofibromatosis type i choristomas forms of heterotopia are closely related benign tumors found in abnormal locations the two can be differentiated as follows a hamartoma is an excess of normal tissue in a normal situation e g a birthmark on the skin while a choristoma is an excess of tissue in an abnormal situation e g pancreatic tissue in the duodenum
in the mathematical field of graph theory the hamiltonian path problem and the hamiltonian cycle problem are problems of determining whether a hamiltonian path a path in an undirected or directed graph that visits each vertex exactly once or a hamiltonian cycle exists in a given graph whether directed or undirected both problems are np complete there is a simple relation between the problems of finding a hamiltonian path and a hamiltonian cycle in one direction the hamiltonian path problem for graph g is equivalent to the hamiltonian cycle problem in a graph h obtained from g by adding a new vertex and connecting it to all vertices of g thus finding a hamiltonian path cannot be significantly slower in the worst case as a function of the number of vertices than finding a hamiltonian cycle in the other direction the hamiltonian cycle problem for a graph g is equivalent to the hamiltonian path problem in the graph h obtained by copying one vertex v of g v that is letting v have the same neighbourhood as v and by adding two dummy vertices of degree one and connecting them with v and v respectively the hamiltonian cycle problem is also a special case of the travelling salesman problem obtained by setting the distance between two cities to one if they are adjacent and two otherwise and verifying that the total distance travelled is equal to n if so the route is a hamiltonian circuit if there is no hamiltonian circuit then the shortest route will be longer
hamman s syndrome also known as macklin s syndrome is a syndrome of spontaneous subcutaneous emphysema air in the subcutaneous tissues of the skin and pneumomediastinum air in the mediastinum the center of the chest cavity sometimes associated with pain and less commonly dyspnea difficulty breathing dysphonia and a low grade fever hamman s syndrome can cause hamman s sign an unusual combination of sounds that can be heard with a stethoscope
a hammer is a type of bullish reversal candlestick pattern made up of just one candle found in price charts of financial assets the candle looks like a hammer as it has a long lower wick and a short body at the top of the candlestick with little or no upper wick in order for a candle to be a valid hammer most traders say the lower wick must be two times greater than the size of the body portion of the candle and the body of the candle must be at the upper end of the trading range when you see the hammer form in a downtrend this is a sign of a potential reversal in the market as the long lower wick represents a period of trading where the sellers were initially in control but the buyers were able to reverse that control and drive prices back up to close near the high for the day thus the short body at the top of the candle after seeing this chart pattern form in the market most traders will wait for the next period to open higher than the close of the previous period to confirm that the buyers are actually in control two additional things that traders will look for to place more significance on the pattern are a long lower wick and an increase in volume for the time period that formed the hammer
a hammer toe or contracted toe is a deformity of the proximal interphalangeal joint of the second third or fourth toe causing it to be permanently bent resembling a hammer mallet toe is a similar condition affecting the distal interphalangeal joint claw toe is another similar condition with dorsiflexion of the proximal phalanx on the lesser metatarsophalangeal joint combined with flexion of both the proximal and distal interphalangeal joints claw toe can affect the second third fourth or fifth toes
the hammersmith ghost murder case of 1804 set a legal precedent in the uk regarding self defence whether someone could be held liable for their actions even if they were the consequence of a mistaken belief near the end of 1803 a number of people claimed to have seen and even been attacked by a ghost in the hammersmith area of london a ghost believed by locals to be the spirit of a suicide victim on 3 january 1804 a member of one of the armed patrols set up in the wake of the reports shot and killed a plasterer thomas millwood mistaking the white clothes of millwood s trade for a ghostly apparition the culprit a 29 year old excise officer named francis smith was found guilty of murder and sentenced to death commuted to one year s hard labour the issues surrounding the case were not settled for 180 years until a court of appeal decision in 1984
the hammick reaction named after dalziel hammick is a chemical reaction in which the thermal decarboxylation of α picolinic or related acids in the presence of carbonyl compounds forms 2 pyridyl carbinols the hammick reaction using p cymene as solvent has been shown to increase yields
in swordsmithing hamon 刃文 hamon from japanese literally blade pattern is a visual effect created on the blade by the hardening process the hamon is the outline of the hardened zone yakiba which contains the cutting edge ha blades made in this manner are known as differentially hardened with a harder cutting edge than spine or mune for example mune 40 hrc vs ha 58 hrc this difference in hardness results from clay being applied on the blade prior to the cooling process quenching less or no clay allows the ha to cool faster making it harder but more brittle while more clay allows the mune to cool slower and retain its resilience the hamon outlines the transition between the region of harder martensitic steel at the blade s edge and the softer pearlitic steel at the center and back of the sword this difference in hardness is the objective of the process the appearance is purely a side effect however the aesthetic qualities of the hamon are quite valuable — not only as proof of the differential hardening treatment but also in its artistic value — and the patterns can be quite complex many modern reproductions do not have natural hamon because they are thoroughly hardened monosteel the appearance of a hamon is reproduced via various processes such as acid etching sandblasting or more crude ones such as wire brushing some modern reproductions with natural hamon are also subjected to acid etching to enhance that hamon s prominence a true hamon can be easily discerned by the presence of a nioi which is a bright speckled line a few millimeters wide following the length of the hamon the nioi is typically best viewed at long angles and cannot be faked with etching or other methods when viewed through a magnifying lens the nioi appears as a sparkly line being made up of many bright martensite grains which are surrounded by darker softer pearlite
hand foot and mouth disease hfmd is a common infection caused by a group of viruses it typically begins with a fever and feeling generally unwell this is followed a day or two later by flat discolored spots or bumps that may blister on the hands feet and mouth and occasionally buttocks and groin signs and symptoms normally appear 3 – 6 days after exposure to the virus the rash generally goes away on its own in about a week fingernail and toenail loss may occur a few weeks later and these then regrow the viruses that cause hfmd are spread through close personal contact through the air from coughing and the feces of an infected person contaminated objects can also spread the disease coxsackievirus a 16 is the most common cause and enterovirus 71 is the second most common cause other strains of coxsackievirus and enterovirus can also be responsible some people may carry and pass on the virus despite having no symptoms of disease other animals are not involved diagnosis can often be made based on symptoms occasionally throat or stool sample may be tested for the virus handwashing may prevent spread and those infected should not go to work daycare or school no antiviral medication or vaccine is available but development efforts are underway most cases require no specific treatment simple pain medication such as ibuprofen or numbing mouth gel may be used occasionally intravenous fluids are given to children who are unable to drink enough rarely viral meningitis or encephalitis may complicate the disease hfmd occurs in all areas of the world it often occurs in small outbreaks in nursery schools or kindergartens large outbreaks have been occurring in asia since 1997 it usually occurs during the spring summer and fall months typically it occurs in children less than five years old but can occasionally occur in adults hfmd should not be confused with foot and mouth disease also known as hoof and mouth disease which mostly affects livestock
hand foot genital syndrome hfgs is characterized by limb malformations and urogenital defects mild bilateral shortening of the thumbs and great toes caused primarily by shortening of the distal phalanx and or the first metacarpal or metatarsal is the most common limb malformation and results in impaired dexterity or apposition of the thumbs urogenital abnormalities include abnormalities of the ureters and urethra and various degrees of incomplete müllerian fusion in females and hypospadias of variable severity with or without chordee in males vesicoureteral reflux recurrent urinary tract infections and chronic pyelonephritis are common fertility is normal
a hand deformity is a disorder of the hand that can be congenital or acquired an example is madelung s deformity
hand eczema presents on the palms and soles and may sometimes be difficult or impossible to differentiate from atopic dermatitis allergic contact dermatitis and psoriasis which also commonly involve the hands even a biopsy of all these conditions may not result in a definitive diagnosis as all three conditions may demonstrate spongiosis and crusting on the hands non communicable inflammation of the skin of the hands is referred to as hand eczema hand eczema is widely prevalent and as it is a very visible condition associated with severe itching or pain has serious consequences for the affected person including a high psychological impact different disease patterns can be identified according to the course of the illness appearance of symptoms degree of severity or catalysts prognosis is hard to predict for individual cases of chronic hand eczema and usually differs from patient to patient successful treatment depends on determining the causes of the condition obtaining an accurate diagnosis sustainable hand protection procedures and an early extensive and where appropriate internal treatment
the hand is a very complex organ with multiple joints different types of ligament tendons and nerves with constant use it is no wonder that hand disease injuries are common in society hand injuries can result from excessive use degenerative disorders or trauma trauma to the finger or the hand is quite common in society in some particular cases the entire finger may be subject to amputation the majority of traumatic injuries are work related today skilled hand surgeons can sometimes reattach the finger or thumb using microsurgery sometimes traumatic injuries may result in loss of skin and plastic surgeons may place skin and muscle grafts
the hand of benediction results from prolonged compression or injury of the median nerve or the ulnar nerve at the forearm or elbow with median nerve compression the benediction sign only appears when the patient attempts to make a fist but is not present with the hand open with ulnar nerve compression the benediction sign only appears when the patient attempts to extend all fingers but is not present with the hand closed the term hand of benediction more frequently refers to damage of the median nerve however median nerve injury prevents the ability to flex the 2 nd and 3 rd digit metacarpophalangeal joint this is due to the loss of innervation of the lateral 2 lumbricals of the hand and the lateral half of the flexor digitorum profundus the extensor digitorum is left unopposed and the metacarpophalangeal joints of the 2 nd and 3 rd digits remain extended while attempting to make a fist ulnar nerve injury prevents the ability to extend the 4 th and 5 th digits by impairing the 3 rd and 4 th lumbricals which results in the inability to extend the proximal and distal interphalangeal joints the name arises from the invocation of a blessing used in christian circles see benediction
a hand pay or handpay is a condition where a slot machine cannot pay the patron in the typical manner requiring the casino staff such as the floor attendant or cashier to pay the customer out manually i e by hand in casinos which use coin in coin out systems a hand pay may be caused by a coin jam inadequate supply of coins in the machine s hopper to pay the requested amount or other problem with the coin out mechanism a hand pay can also be triggered when the win is large enough that the number of coins required to pay out the win would be excessive in casinos that use ticket in ticket out cashless systems a hand pay can be caused by communication or other issues with the ticket printer more frequently it is caused by communication problems with the server which tracks and assigns ticket serial numbers hand pays also occur whenever the amount of the win is over the minimum taxable win amount for the jurisdiction that the machine is in this allows the floor attendant to collect the patron s identification and tax id numbers such as the social security number in the united states and other pertinent information such as the winning combination the patron is then provided with the applicable tax forms in the united states a hand pay will normally occur for all wins over 1 200 which is the amount above which winnings must be reported to the irs some states may have lower thresholds where the taxes must be reported to the state revenue office citizens of the united states winning in that country will receive a w 2 g tax form and often a w 9 form to validate that the social security number they provided is correct to perform a hand pay a floor attendant may complete a form which the patron presents to the cash cage to be paid out in other casinos the floor attendant will retrieve the funds and pay the patron directly the latter is typical for hand pays resulting from taxable wins most casinos will require an electronic record of the hand pay to be made through the slot accounting system
field handball at the 1936 summer olympics was the first appearance of the sport at the olympics it was contested by six teams the six teams were split into two groups of three each team played the other two teams in its group once the top two teams in each group advanced to the final round while the third ranked teams played each other for fifth and sixth places in the final round each team played all three other teams once final rankings were based on the records of each team in those three games
handball at the 1972 summer olympics was the second appearance of the sport at the olympics returning to the olympic program after a 36 year absence it was contested by sixteen teams the teams were split into four groups of four teams each each team played every other team in its group the lowest team in group a played the lowest in group b while the lowest in groups c and d played each other the winners of those games played each other for 13 th and 14 th places while the losers played each other for 15 th and 16 th the third ranked teams in groups a and b also played each as did those in groups c and d again the winners of those games played each other this time for 9 th and 10 th places the losers played for 11 th and 12 th places the top two teams in each group advanced to the main round those from groups a and b became group i while those from groups c and d became group ii another round robin was played within those groups with the results from the preliminary round carrying over the fourth ranked teams in each of the two main round groups played each other for 7 th and 8 th place the third ranked teams played against each other for 5 th and 6 th place the second ranked teams played for the bronze medal and 4 th place the top teams in group i and group ii played each other for the gold and silver medals
handigodu syndrome is a rare and painful osteoarthritic disorder endemic to the malnad region in the state of karnataka india also known as handigodu joint disease it derives its name from the village of handigodu in the sagara taluk of the shimoga district of karnataka where it was first noticed this disease currently has no cure scientifically it is termed as endemic familial arthritis of malnad since the day it was discovered it has claimed over 1000 lives and has left many people crippled apart from sagara taluk the disease has also been reported from the koppa narasimharajapura and sringeri taluks of chikkamagaluru district
handwriting recognition or hwr is the ability of a computer to receive and interpret intelligible handwritten input from sources such as paper documents photographs touch screens and other devices the image of the written text may be sensed off line from a piece of paper by optical scanning optical character recognition or intelligent word recognition alternatively the movements of the pen tip may be sensed on line for example by a pen based computer screen surface a generally easier task as there are more clues available handwriting recognition principally entails optical character recognition however a complete handwriting recognition system also handles formatting performs correct segmentation into characters and finds the most plausible words
hand – schüller – christian disease is associated with multifocal langerhans cell histiocytosis it is associated with a triad of exophthalmos lytic bone lesions often in the skull and diabetes insipidus from pituitary stalk infiltration it is named for alfred hand artur schüller and henry asbury christian
a hanging man is a type of bearish reversal pattern made up of just one candle found in an uptrend of price charts of financial assets it has a long lower wick and a short body at the top of the candlestick with little or no upper wick in order for a candle to be a valid hanging man most traders say the lower wick must be two times greater than the size of the body portion of the candle and the body of the candle must be at the upper end of the trading range
hanging miniature is an in camera special effect similar to a matte shot where a model rather than a painting is placed in foreground and the action takes place in the background it is thus a specific form of forced perspective
hangman s fracture is the colloquial name given to a fracture of both pedicles or pars interarticularis of the axis vertebra c 2 or epistropheus
a hangover is the experience of various unpleasant physiological and psychological effects following the consumption of ethanol as found in wine beer and distilled spirits hangovers can last for several hours or for more than 24 hours typical symptoms of a hangover may include headache drowsiness concentration problems dry mouth dizziness fatigue gastrointestinal distress e g vomiting absence of hunger sweating nausea hyper excitability and anxiety while the causes of a hangover are still poorly understood several factors are known to be involved including acetaldehyde accumulation changes in the immune system and glucose metabolism dehydration metabolic acidosis disturbed prostaglandin synthesis increased cardiac output vasodilation sleep deprivation and malnutrition beverage specific effects of additives or by products such as congeners in alcoholic beverages also play an important role the symptoms occur typically after the intoxicating effect of the alcohol begins to wear off generally the morning after a night of heavy drinking though many possible remedies and folk cures have been suggested there is no compelling evidence to suggest that any are effective for preventing or treating alcohol hangover avoiding alcohol or drinking in moderation are the most effective ways to avoid a hangover the socioeconomic consequences and health risks of alcohol hangover include workplace absenteeism impaired job performance reduced productivity and poor academic achievement a hangover may also compromise potentially dangerous daily activities such as driving a car or operating heavy machinery
hanhart syndrome is a congenital disorder that causes an undeveloped tongue and malformed extremities and fingers
hansen s problem is a problem in planar surveying named after the astronomer peter andreas hansen 1795 – 1874 who worked on the geodetic survey of denmark there are two known points a and b and two unknown points p 1 and p 2 from p 1 and p 2 an observer measures the angles made by the lines of sight to each of the other three points the problem is to find the positions of p 1 and p 2 see figure the angles measured are α 1 β 1 α 2 β 2 since it involves observations of angles made at unknown points the problem is an example of resection as opposed to intersection
hantaviruses are single stranded enveloped negative sense rna viruses in the bunyaviridae family which can kill humans they normally infect rodents and do not cause disease in these hosts humans may become infected with hantaviruses through contact with rodent urine saliva or feces some strains of hantaviruses cause potentially fatal diseases in humans such as hantavirus hemorrhagic fever with renal syndrome hfrs and hantavirus pulmonary syndrome hps — also known as hantavirus cardiopulmonary syndrome hcps — while others have not been associated with known human disease hps hcps is a rare respiratory illness associated with the inhalation of aerosolized rodent excreta urine and feces contaminated by hantavirus particles human infections of hantaviruses have almost entirely been linked to human contact with rodent excrement but recent human to human transmission has been reported with the andes virus in south america hantavirus is named for the hantan river area in south korea where an early outbreak was observed the virus was isolated in the late 1970 s by karl m johnson and ho wang lee
the hantzsch pyridine synthesis or hantzsch dihydropyridine synthesis is a multi component organic reaction between an aldehyde such as formaldehyde 2 equivalents of a β keto ester such as ethyl acetoacetate and a nitrogen donor such as ammonium acetate or ammonia the initial reaction product is a dihydropyridine which can be oxidized in a subsequent step to a pyridine the driving force for this second reaction step is aromatization this reaction was reported in 1881 by arthur rudolf hantzsch a 1 4 dihydropyridine dicarboxylate is also called a 1 4 dhp compound or a hantzsch compound these compounds are an important class of calcium channel blockers and as such commercialized in for instance nifedipine amlodipine or nimodipine the reaction has been demonstrated to proceed in water as reaction solvent and with direct aromatization by ferric chloride manganese dioxide or potassium permanganate in a one pot synthesis hantzsch reaction with ammonium acetate ethyl acetoacetate formaldehyde and ferric chloride the hantzsch dihydropyridine synthesis is found to benefit from microwave chemistry
the hantzsch pyrrole synthesis named for arthur rudolf hantzsch is the chemical reaction of β ketoesters 1 with ammonia or primary amines and α haloketones 2 to give substituted pyrroles 3 pyrroles are found in a variety of natural products with biological activity so the synthesis of substituted pyrroles has important applications in medicinal chemistry alternative methods for synthesizing pyrroles exist such as the knorr pyrrole synthesis and paal knorr synthesis the hantzch pyrrole synthesis
hapalonychia also known as egg shell nail is a condition in which the top of a toe or finger nail becomes soft and thin causing it to bend or break this condition can manifest as a result of genetic discrepancy and may also occur due to malnutrition and debility nails are often a representation of the internal nutritional of health although overall well being is not typically determined by nail health fissures breaks and calcium spots are minor indications of inner health hapalonychia may also be attributed to myxedema rheumatoid arthritis anorexia bulimia hansen s disease raynaud phenomenon oral retinoid therapy or radiodermatitis
hapnes boman skeie syndrome is a rare genetic disorder first described by sveln hapnes et al in 1980 it is characterized by subcutaneous angiolipomas around the wrists knees and ankles it is also known as anomalous insertion of extensor tendons of fingers a name derived from the condition that the tendons of the fingers are attached in such a way that the fingers cannot open or close normally though the tumors extend deeply into the muscle tissue joints and tendons the tumors did not invade these structures
haramaki japanese 腹巻 lit bellyband are items of japanese clothing that cover the stomach they are worn for health and fashion reasons
the hard problem of consciousness is the problem of explaining how and why we have qualia or phenomenal experiences — how sensations acquire characteristics such as colors and tastes the philosopher david chalmers who introduced the term hard problem of consciousness contrasts this with the easy problems of explaining the ability to discriminate integrate information report mental states focus attention etc easy problems are easy because all that is required for their solution is to specify a mechanism that can perform the function that is their proposed solutions regardless of how complex or poorly understood they may be can be entirely consistent with the modern materialistic conception of natural phenomena chalmers claims that the problem of experience is distinct from this set and he argues that the problem of experience will persist even when the performance of all the relevant functions is explained the existence of a hard problem is controversial and has been disputed by philosophers such as daniel dennett and cognitive neuroscientists such as stanislas dehaene clinical neurologist and skeptic steven novella has dismissed it as the hard non problem
harderoporphyria is a rare disorder of heme biosynthesis inherited in an autosomal recessive manner caused by specific mutations in the cpox gene mutations in cpox usually cause hereditary coproporphyria an acute hepatic porphyria however the k 404 e mutation in a homozygous or compound heterozygous state with a null allele cause the more severe harderoporphyria harderoporphyria is the first known metabolic disorder where the disease phenotype depended on the type and location of the mutations in a gene associated with multiple disorders in contrast with other porphyrias which typically present with either cutaneous lesions after exposure to sunlight or acute neurovisceral attack at any age most commonly in adulthood harderoporphyria is characterized by jaundice anemia enlarged liver and spleen often presenting in the neonatal period later in life these individuals may present with photosensitivity similar to that found in cutaneous porphyrias biochemically harderoporphyria presents with a distinct pattern of increased harderoporphyrin 2 vinyl 4 6 7 tripropionic acid porphyrin in urine and particularly in feces a metabolite that is not seen in significant quantities in any other porphyria enzyme tests show markedly reduced activity of coproporphyrinogen oxidase compared to both unaffected individuals and those affected with hereditary coproporphyria consistent with recessive inheritance harderoporphyria is a rare condition with less than 10 cases reported worldwide it may be underdiagnosed as it does not have the typical presentation associated with a porphyria it was identified as a variant type of coproporphyria in 1983 in a family with three children identified at birth with jaundice and hemolytic anemia there is no standard treatment for harderoporphyria care is mainly focused on the management of symptoms
harding ataxia also known as early onset cerebellar ataxia with retained reflexes eocarr is an autosomal recessive cerebellar ataxia originally described by harding in 1981 this form of cerebellar ataxia is similar to friedreich ataxia including that it results in poor reflexes and balance but differs in several ways including the absence of diabetes mellitus optic atrophy cardiomyopathy skeletal abnormalities and the fact that tendon reflexes in the arms and knees remain intact this form of ataxia is characterized by onset in the first 20 years and is less severe than friedreich ataxia additional cases were diagnosed in 1989 1990 1991 and 1998
in mathematics harish chandra s c function is a function related to the intertwining operator between two principal series representations that appears in the plancherel measure for semisimple lie groups harish chandra introduced a special case of it defined in terms of the asymptotic behavior of a zonal spherical function of a lie group and harish chandra introduced a more general c function called harish chandra s generalized c function gindikin and karpelevich introduced the gindikin – karpelevich formula a product formula for harish chandra s c function
in mathematical harmonic analysis harish chandra s ξ function is a special spherical function on a semisimple lie group studied by harish chandra section 16 harish chandra used it to define harish chandra s schwartz space 4 5 gives a detailed description of the properties of ξ
harlequin type ichthyosis is a very rare severe genetic disease which causes thickening of the skin at birth the child ’ s whole body is encased in an armour of thick white plates of skin separated with deep cracks in addition the eyes ears penis and limbs may be abnormally contracted because of resultant cracked skin in locations where normal skin would fold it is easily pregnable by bacteria and other contaminants which can result in serious risk of fatal infection it is an autosomal recessive congenital ichthyosis which is a group of nonsyndromic disorders of keratinization it is associated with a mutation in the gene for the protein abca 12 the disease can be diagnosed in the uterus by way of fetal skin biopsy or by analysis of amniotic fluid cells obtained by amniocentesis common features of the disease can be recognized through ultrasound and follow up with 3 d ultrasound to diagnose the condition ultrasound can reveal abnormal facial features with ectropion eclabium short foot length incurved toes clenched fists poor delineation of nostrils and polyhydramnios constant care is required to moisturise and protect the skin the overall rate of harlequin ichthyosis is 1 in 300 000 births the harlequin type designation comes from the diamond shape of the scales at birth resembling the costume of arlecchino
harlequin color change is a cutaneous condition seen in newborn babies characterized by momentary red color changes of half the child sharply demarcated at the body s midline this transient change occurs in approximately 10 of healthy newborns it is seen usually between two and five days of birth the condition lasts from 30 seconds to 20 minutes and then fades it may recur when the infant is placed on his or her side as the intensity of color has been shown to be gravity dependent and considerably variable from one infant to another the dark red color skin of the newborn with harlequin signs indicates polycythemia polycythemia is common in preterm infants because of the presence of fetal red blood cells rbcs the condition is also often seen in healthy newborns although associations like with prematurity low birth weight hypoxia systemic use of prostaglandin e 1 or intracranial injury meningitis and even anesthesia has been mentioned in the literature probable differential diagnosis are port wine stain and nascent hemangioma of infancy but these can be differentiated due to transient nature of this condition hypothesized pathogenesis involves temporary imbalance in the tone of cutaneous blood vessels secondary to hypothalamic immaturity this condition was first described by neligan and strang in 1952 and was named so
harlequin syndrome is a condition characterized by asymmetric sweating and flushing on the upper thoracic region of the chest the neck and the face it is caused by sustaining an injury to the sympathetic nervous system listed as a rare disease harlequin syndrome affects fewer than 200 000 people in the united states it can also be the outcome of a unilateral endoscopic thoracic sympathectomy ets or endoscopic sympathetic blockade esb surgery see endoscopic thoracic sympathectomy
in psychology harm avoidance ha is a personality trait characterized by excessive worrying pessimism shyness and being fearful doubtful and easily fatigued in mri studies ha was correlated with reduced grey matter volume in the orbito frontal occipital and parietal regions harm avoidance is a temperament assessed in the temperament and character inventory tci its revised version tci r and the tridimensional personality questionnaire tpq and is positively related to the trait neuroticism and inversely to extraversion in the revised neo personality inventory and the eysenck personality questionnaire researchers have contended that harm avoidance represents a composite personality dimension with neurotic introversion at one end of the spectrum and stable extraversion at the other end harm avoidance has also been found to have moderate inverse relationships with conscientiousness and openness to experience in the five factor model the ha of tpq and tci r has four subscales 1 anticipatory worry ha 1 2 fear of uncertainty ha 2 3 shyness shyness with strangers ha 3 4 fatigability fatigability and asthenia ha 4 it has been suggested that ha is related to high serotonergic activity and much research has gone into investigating the link between ha and components of the serotonin system e g genetic variation in 5 httlpr in the serotonin transporter gene
in mathematics a weak maass form is a smooth function f on the upper half plane transforming like a modular form under the action of the modular group being an eigenfunction of the corresponding hyperbolic laplace operator and having at most linear exponential growth at the cusps if the eigenvalue of f under the laplacian is zero then f is called a harmonic weak maass form or briefly a harmonic maass form a weak maass form which has actually moderate growth at the cusps is a classical maass wave form the fourier expansions of harmonic maass forms often encode interesting combinatorial arithmetic or geometric generating functions regularized theta lifts of harmonic maass forms can be used to construct arakelov green functions for special divisors on orthogonal shimura varieties
the harmonic seventh chord is a major triad plus the harmonic seventh interval ratio of 7 4 about 968 826 cents this interval is somewhat narrower about 48 77 cents a septimal quarter tone and is sweeter in quality than an ordinary minor seventh which has a just intonation ratio of 9 5 1017 596 cents or an equal temperament ratio of 1000 cents 25 6 1 frequent use of this chord is one of the defining characteristics of blues and barbershop harmony barbershoppers refer to it as the barbershop seventh since barbershop music tends to be sung in just intonation the barbershop seventh chord may be accurately termed a harmonic seventh chord the harmonic seventh chord is also widely used in blues flavored music as guitars pianos and other equal temperament instruments cannot play this chord it is frequently approximated by a dominant seventh chord as a result it is often called a dominant seventh chord and written with the same symbols such as the blues progression i 7 v 7 iv 7 a frequently encountered example of the harmonic seventh chord is the last word of the and many more modern addition to the song happy birthday to you when sung by professional singers the harmony on the word more typically takes the form of a harmonic seventh chord the alpha scale has excellent harmonic seventh chords using the inversion of 7 4 i e 8 7 it is suggested that the harmonic seventh on the dominant not be used as a suspension since this would create a mistuned fourth over the tonic the harmonic seventh of g f 7 is lower than the perfect fourth over c f ♮ by archytas comma 27 25 cents 22 equal temperament avoids this problem because it tempers out this comma while still offering a reasonably good approximation of the harmonic seventh chord
harpist s fingers are a cutaneous condition caused by the repetitive playing of the harp
harrison syndrome is a type of chronic gout associated with presence of tophi
hartnup disease also known as pellagra like dermatosis and hartnup disorder is an autosomal recessive metabolic disorder affecting the absorption of nonpolar amino acids particularly tryptophan that can be in turn converted into serotonin melatonin and niacin niacin is a precursor to nicotinamide a necessary component of nad the causative gene slc 6 a 19 is located on chromosome 5
hashimoto s encephalopathy also known as steroid responsive encephalopathy associated with autoimmune thyroiditis sreat is a neourological condition characterized by encephalopathy thyroid autoimmunity and good clinical response to steroids it is associated with hashimoto s thyroiditis it was first described in 1966 it is sometimes referred to as a neuroendocrine disorder although the condition s relationship to the endocrine system is widely disputed it is recognized as a rare disease by the nih genetic and rare diseases information center up to 2005 there were almost 200 published case reports of this disease between 1990 and 2000 43 cases were published since that time research has expanded and numerous cases are being reported by scientists around the world suggesting that this rare condition is likely to have been significantly undiagnosed in the past over 100 scientific articles on hashimoto s encephalopathy were published between 2000 and 2013
hashimoto s thyroiditis also known as chronic lymphocytic thyroiditis is an autoimmune disease in which the thyroid gland is gradually destroyed early on there may be no symptoms over time the thyroid may enlarge forming a painless goitre some people eventually develop hypothyroidism with its accompanying weight gain feeling tired constipation depression and general pains after many years the thyroid typically shrinks in size potential complications include thyroid lymphoma hashimoto s thyroiditis is thought to be due to a combination of genetic and environmental factors risk factors include a family history of the condition and having another autoimmune diseases diagnosis is confirmed with blood tests for tsh t 4 and antithyroid antibodies other conditions that can produce similar symptoms include graves ’ disease and nontoxic nodular goiter hashimoto s thyroiditis regardless of whether or not hypothyroidism is present can be treated with levothyroxine if hypothyroidism is not present some may recommend no treatment while others may treat to try to reduce the size of the goitre those affected should avoid eating large amounts of iodine however sufficient iodine is required especially during pregnancy surgery is rarely required to treat the goitre hashimoto s thyroiditis affects about 5 of the population at some point in their life it typically begins between the ages of 30 and 50 and is much more common in women than men rates of disease appear to be increasing it was first described by the japanese physician hakaru hashimoto in 1912 in 1957 it was recognized as an autoimmune disorder
hat puzzles are logic problems that date back to as early as 1961 a number of players at least three are each wearing a hat which may be of various specified colours players can see the colours of at least some other players hats but not that of their own with highly restricted communication or none some of the players must guess the colour of their hat the problem is to find a strategy for the players to determine the colours of their hats based on the hats they see and what the other players do in some versions they compete to be the first to guess correctly in others they can work out a strategy beforehand to cooperate and maximize the probability of correct guesses another version is the white hat black hat version there are three men sitting around a round table there are five hats on the table two black three white all three men are then blindfolded hats are placed on their heads the other hats are then removed these men are supposed to figure out the colour of their hat by only looking at the other men s hats the first man removes his blindfold after looking at the other men s hats he says that he cannot figure out the colour of his hat and gives up the second man then removes his blindfold looking at the other men and cannot figure out the colour of his hat and gives up but the third man without removing his blindfold says the colour of his hat correctly what colour hat is the third man wearing and how did he figure it solution the third man was wearing a white hatthe first man takes off his blindfold if the other two men were wearing a black hat he would have known he was wearing a white hat therefore not possible so one or none of the other men were wearing a black hat the second man took off his blindfold while looking at the third man he realised that if the third man was wearing a black hat that he could not so he would have to be wearing a white hat cause he was unsure of his own hat colour therefore guaranteeing the third man having a white hat one variation received some new publicity as a result of todd ebert s 1998 ph d thesis at the university of california santa barbara it is a strategy question about a cooperative game which has connections to algebraic coding theory
hatchings are distinctive and systematic patterns of lines and dots used for designating heraldic tinctures or other colours on uncoloured surfaces such as woodcuts or engravings seals and coins several systems of hatchings were developed during the renaissance as an alternative to tricking the earlier method of indicating heraldic tinctures by use of written abbreviations the present day hatching system was developed during the 1630 s by silvester petra sancta and marcus vulson de la colombière some earlier hatching methods were also developed but did not come into wide use
haverhill fever or epidemic arthritic erythema is a form of rat bite fever caused by the bacterium streptobacillus moniliformis an organism common in rats and mice symptoms begin to appear two to ten days after a rat bite injury the illness resembles a severe influenza with a moderate fever 38 40 ° c or 101 104 ° f chills joint pain and a diffuse red rash located mostly on the hands and feet the causative organism can be isolated by blood culture and penicillin is the most common treatment treatment is usually quite successful although the body can clear the infection by itself in most cases complications are rare but can include endocarditis and meningitis despite its name it can present without being bitten by a rat the disease was recognized from an outbreak which occurred in haverhill massachusetts in january 1926 the organism s moniliformis was isolated from the patients epidemiology implicated infection via consumption of milk from one particular dairy
a hawaiian eruption is a type of volcanic eruption where lava flows from the vent in a relatively gentle low level eruption it is so named because it is characteristic of hawaiian volcanoes typically they are effusive eruptions with basaltic magmas of low viscosity low content of gases and high temperature at the vent very little amounts of volcanic ash are produced this type of eruption occurs most often at hotspot volcanoes such as kīlauea and iceland though it can occur near subduction zones e g medicine lake volcano in california united states and rift zones another example of hawaiian eruptions occurred on surtsey from 1964 to 1967 when molten lava flowed from the crater to the sea hawaiian eruptions may occur along fissure vents such as during the eruption of mauna loa volcano in 1950 or at a central vent such as during the 1959 eruption in kīlauea iki crater which created a lava fountain 580 meters 1 900 ft high and formed a 38 meter cone named puʻu puaʻi in fissure type eruptions lava spurts from a fissure on the volcano s rift zone and feeds lava streams that flow downslope in central vent eruptions a fountain of lava can spurt to a height of 300 meters or more heights of 1600 meters were reported for the 1986 eruption of mount mihara on izu ōshima japan hawaiian eruptions usually start by the formation of a crack in the ground from which a curtain of incandescent magma or several closely spaced magma fountains appear the lava can overflow the fissure and form ʻaʻā or pāhoehoe style of flows when such an eruption from a central cone is protracted it can form lightly sloped shield volcanoes for example mauna loa or skjaldbreiður in iceland
hawkinsinuria also called 4 alpha hydroxyphenylpyruvate hydroxylase deficiency is an autosomal dominant metabolic disorder affecting the metabolism of tyrosine normally the breakdown of the amino acid tyrosine involves the conversion of 4 hydroxyphenylpyruvate to homogentisate by 4 hydroxyphenylpyruvate dioxygenase complete deficiency of this enzyme would lead to tyrosinemia iii in rare cases however the enzyme is still able to produce the reactive intermediate 1 2 epoxyphenyl acetic acid but is unable to convert this intermediate to homogentisate the intermediate then spontaneously reacts with glutathione to form 2 l cystein s yl 1 4 dihydroxy cyclohex 5 en 1 yl acetic acid hawkinsin patients present with metabolic acidosis during the first year of life which should be treated by a phenylalanine and tyrosine restricted diet the tolerance toward these amino acids normalizes as the patients get older then only a chlorine like smell of the urine indicates the presence of the condition patients have a normal life and do not require treatment or a special diet the production of hawkinsin is the result of a gain of function mutation inheritance of hawkinsinuria is therefore autosomal dominant presence of a single mutated copy of the gene causes the condition most other inborn errors of metabolism are caused by loss of function mutations and hence have recessive inheritance condition occurs only if both copies are mutated
the hayashi rearrangement is the chemical reaction of ortho benzoylbenzoic acids catalyzed by sulfuric acid or phosphorus pentoxide the hayashi rearrangement this reaction proceeds through electrophilic acylium ion attack with a spiro intermediate hayashi mechanism
a hayrake table is a distinct pattern of table produced as part of the english arts and crafts movement in the early part of the twentieth century its distinctive feature is the arrangement of the lower stretcher between the legs as a double ended y shape the shape of each end and their joinery was based on traditional english craft woodworking and the construction of wooden hay rakes the stretcher is not merely a simple y shape but its junction is braced by a t shaped joint as was needed for the work of a rake some modern reproductions simplify this to a plain y abandoning the design s original roots these tables are best known as the work of ernest gimson and his associates the barnsley brothers and peter waals at their daneway workshops in sapperton gloucestershire other arts and crafts designers of the period also produced them particularly those in the cotswolds such as gordon russell timber used in their construction was as for other arts and crafts work locally grown english hardwoods most were produced in oak although some like the original hay rakes were made in ash the design varies between makers mostly in its details gimson s tables are considered the finest and the canonical example of the design their edges are heavily chamfered a typically gimson feature which is derived from the finishing of the original agricultural tools this chamfer also has the practical benefit for a table stretcher of reduced wear from feet on an otherwise sharp edge gimson s distinctive use of gentle stopped chamfers evokes the framing of gloucestershire wagons gimson s tables also have their edges finished with bands of chip carving or sometimes with inlaid bands of light holly and dark bog oak peter waals produced the tables for some time after the death of gimson and as with many of his pieces updated their arts and crafts detailing to follow the post war fashions of modernism and art deco although less well known than some other iconic arts and crafts pieces the hayrake table remains a popular design to this day they are produced both commercially and as plans for hobbyists
hay – wells syndrome also known as aec syndrome see is one of at least 150 known types of ectodermal dysplasia these disorders affect tissues that arise from the ectodermal germ layer such as skin hair and nails
in the domain of central processing unit cpu design hazards are problems with the instruction pipeline in cpu microarchitectures when the next instruction cannot execute in the following clock cycle and can potentially lead to incorrect computation results three common types of hazards are data hazards structural hazards and control flow hazards branching hazards there are several methods used to deal with hazards including pipeline stalls pipeline bubbling and in the case of out of order execution the scoreboarding method and the tomasulo algorithm
in digital logic a hazard in a system is an undesirable effect caused by either a deficiency in the system or external influences logic hazards are manifestations of a problem in which changes in the input variables do not change the output correctly due to some form of delay caused by logic elements not and or gates etc this results in the logic not performing its function properly the three different most common kinds of hazards are usually referred to as static dynamic and function hazards hazards are a temporary problem as the logic circuit will eventually settle to the desired function therefore in synchronous designs it is standard practice to register the output of a circuit before it is being used in a different clock domain or routed out of the system so that hazards do not cause any problems if that is not the case however it is imperative that hazards be eliminated as they can have an effect on other connected systems
head of line blocking hol blocking in computer networking is a performance limiting phenomenon that occurs when a line of packets is held up by the first packet examples include input buffered network switches out of order delivery and multiple requests in http pipelining
head and lateral line erosion hlle or hole in the head hith is a disease in fish chronic ulcerative dermatopathy or chronic erosive dermatopathy are symptoms of similar conditions with different etiology
head and neck cancer is a group of cancers that starts within the mouth nose throat larynx sinuses or salivary glands symptoms may include a lump or sore that does not heal a sore throat that does not go away trouble swallowing or a change in the voice there may also be unusual bleeding facial swelling or trouble breathing about 80 of head and neck cancer is due to the use of alcohol or tobacco other risk factors include betel quid certain types of human papillomavirus radiation exposure certain workplace exposures and epstein barr virus head and neck cancers are most commonly of the squamous cell carcinoma type the diagnosis is confirmed by tissue biopsy the degree of spread may be determined by medical imaging and blood tests prevention is by not using tobacco or alcohol while screening in the general population does not appear to be useful screening high risk groups by examination the throat might be useful often head and neck cancer is curable if detected early however outcomes are typically poor if detected late treatment may include a combination of surgery radiation therapy chemotherapy and targeted therapy following treatment of one head and neck cancer people are at higher risk of a second cancer in 2013 head and neck cancers globally affected more than 4 6 million people mouth 2 4 million throat 1 3 million larynx 0 9 million and resulted in more than 362 000 deaths mouth 135 000 throat 139 000 larynx 88 000 together they are the seventh most frequent cancer and the ninth most frequent cause of death from cancer in the united states about one percent of people are affected at some point in their life and males are affected twice as often as females the usually age at diagnosis is between 55 and 65 years the average 5 year survival following diagnosis in the developed world is 42 to 64
head and neck cancers are malignant neoplasms that arise in the head and region which comprises nasal cavity paranasal sinuses oral cavity salivary glands pharynx and larynx the majority of head and neck cancers histologically belong to squamous cell type and hence they are categorized as head and neck squamous cell carcinoma abbreviated as hnscc forastiere aa 2003 hnscc is the sixth most common type of cancer world wide and account for 5 of all malignancies world wide ferlay j 2010 and 3 of all malignancies in the united states siegel r 2014 risk factors include tobacco consumption chewing or smoking alcohol consumption human papilloma virus hpv infections esp hpv 16 18 betel nut chewing wood dust exposures and others nci factsheet 2013 symptoms include lump or sore sore throat hoarse of voice difficulty in swallowing etc nci factsheet 2013 treatment for hnscc is based on the stage of the disease standard of care for hnscc includes one or combination of the following surgery radiation chemotherapeutic agents such as cisplatin 5 flurouracil 5 fu etc molecularly targeted therapies were developed since the discovery of role of epidermal growth factor receptor egfr signaling in hnscc development progression and prognosis these targeted therapies include monoclonal antibodies such as cetuximab panitumumab etc and tyrosine kinase inhibitors such as erlotinib gefitinib etc among these egfr targeting agents only cetuximab has been approved by fda in 2006 for hnscc treatment ninety percent of cases of head and neck cancer cancer of the mouth nasal cavity nasopharynx throat and associated structures are due to squamous cell carcinoma symptoms may include a poorly healing mouth ulcer a hoarse voice or other persistent problems in the area treatment is usually with surgery which may be extensive and radiotherapy risk factors include smoking alcohol consumption and hematopoietic stem cell transplantation in addition recent studies show that about 25 of mouth and 35 of throat cancers are associated with hpv the 5 year disease free survival rate for hpv positive cancer is significantly higher when appropriately treated with surgery radiation and chemotherapy as compared to non hpv positive cancer substantiated by multiple studies including research conducted by maura gillison et al of johns hopkins sidney kimmel cancer center
any injury that results in trauma to the skull or brain can be classified as a head injury the terms traumatic brain injury and head injury are often used interchangeably in the medical literature this broad classification includes neuronal injuries hemorrhages vascular injuries cranial nerve injuries and subdural hygromas among many others these classifications can be further categorized as open penetrating or closed head injuries this depends on if the skull was broken or not because head injuries cover such a broad scope of injuries there are many causes — including accidents falls physical assault or traffic accidents — that can cause head injuries many of these are minor but some can be severe enough to require hospitalization the incidence number of new cases of head injury is 1 7 million people in the united states alone each year with about 3 of these incidents leading to death adults suffer head injuries more frequently than any age group resulting from falls motor vehicle crashes colliding or being struck by an object or assaults children however may experience head injuries from accidental falls or intentional causes such as being struck or shaken leading to hospitalization unlike a broken bone where trauma to the body is obvious head trauma can sometimes be conspicuous or inconspicuous in the case of an open head injury the skull is cracked and broken by an object that makes contact with the brain this leads to bleeding other obvious symptoms can be neurological in nature the person may become sleepy behave abnormally lose consciousness vomit develop a severe headache have mismatched pupil sizes and or be unable to move certain parts of the body while these symptoms happen right after head injury occurs many problems can develop later in life alzheimer ’ s disease for example is much more likely to develop in a person who has experienced a head injury
head lice infestation also known as pediculosis capitis nits or cooties is the infection of the head hair and scalp by the head louse pediculus humanus capitis itching from lice bites is common during a person s first infection the itch may not develop for up to six weeks if a person is infected again symptoms may begin much more quickly the itch may cause problems with sleeping generally however it is not a serious condition while head lice appear to spread some other diseases in africa they do not appear to do so in europe or north america head lice are spread by direct contact with the hair of someone who is infected the cause of head lice infestations are not related to cleanliness other animals such as cats and dogs do not play a role in transmission head lice feed only on human blood and are only able to survive on human head hair when adults they are about 2 to 3 mm long when not attached to a human they are unable to live beyond three days humans can also become infected with two other lice – the body louse and the crab louse to make the diagnosis live lice must be found using a comb can help with detection empty eggshells known as nits are not sufficient for the diagnosis possible treatments include combing the hair frequently with a fine tooth comb or shaving the head completely a number of topical medications are also effective including malathion ivermectin and dimethicone dimethicone which is a silicone oil is often preferred due to the low risk of side effects pyrethroids such as permethrin have been commonly used however have become less effective due to increasing pesticide resistance there is little evidence for alternative medicines head lice infestations are common especially in children in europe they infect between 1 and 20 of different groups of people in the united states between 6 and 12 million children are infected a year they occur more often in girls than boys it has been suggested that historically head lice infection were beneficial as they protected against the more dangerous body louse infestations may cause stigmatization of the infected individual
head pressing is a veterinary condition characterized by standing close to a wall or corner face first without moving this condition is seen in pets such as dogs and cats and also other animals such as cows horses and goats head pressing is usually a sign of a neurological disorder especially of the forebrain e g prosencephalon disease or of toxicity due to liver damage such as portosystemic shunt and hepatic encephalopathy it should be distinguished from bunting which is a normal behavior found in healthy animals
headache is the symptom of pain anywhere in the region of the head or neck it occurs in migraines tension type headaches and cluster headaches frequent headaches can affect relationships and employment there is also an increased risk of depression in those with severe headaches headaches can occur as a result of many conditions whether serious or not there are a number of different classification systems for headaches the most well recognized is that of the international headache society causes of headaches may include fatigue sleep deprivation stress the effects of medications the effects of recreational drugs viral infections common colds head injury rapid ingestion of a very cold food or beverage and dental or sinus issues treatment of a headache depends on the underlying cause but commonly involves pain medication some form of headache is one of the most commonly experienced of all physical discomforts about half of adults have a headache in a given year tension headaches are the most common affecting about 1 6 billion people 21 8 of the population followed by migraine headaches which affect about 848 million 11 7
these headaches have been further sub classified by the ichd 2 into headaches induced by acute substance use or exposure medication overuse headaches moh headaches attributed to chronic medication use headaches attributed to substance withdrawal
headshaking is a condition where the horse or pony shakes its head continuously often while being ridden originally considered a bad habit it is now thought that some horses are allergic to certain pollens which causes them to headshake however horses also normally react to flies and headshaking may be a fly defence overreaction even if flies are not present sometime the halter or bridle is maladjusted or irritating the animal as the rider is using rein commands the use of nose nets is thought to improve the problem nose nets are not allowed in all competitions however british dressage has approved of the use of some muzzle nets
the head – body pattern is a common xml design pattern used for example in the soap protocol this pattern is useful when a message or parcel of data requires considerable metadata while mixing the meta data with the data could be done it makes the whole confusing in this pattern the meta data or meta information are structured as the header sometimes known as the envelope the ordinary data or information are structured as the body sometimes known as the payload xml is employed for both head and body see also xml protocol
a healing factor is the ability of some characters in fiction to recover from bodily injuries or disease at a superhuman rate since the introduction of wolverine by marvel comics in 1974 and inspired by the immense popularity of the character superhuman healing has become a fairly common power featured in comic books novels television film and other mediums the overall efficiency of a character s healing factor often fluctuates due to various writers applying a very broad degree of artistic license weapon x has been established on multiple accounts for having the fastest healing factor over all mutants with the exception of external factors as a result especially concerning characters depicted in comic books it has become a very common source of debate among fans over the years it has also become common for healing factors to have an umbrella effect serving as a partial source for multiple superhuman abilities various powers thus demonstrated include superhuman strength speed stamina agility reflexes durability and or senses to name the most common the source of a character s healing factor depending upon the medium usually ranges from natural genetic mutation accidental exposure to radioactive materials artificially induced genetic enhancement cybernetic augmentation magic or even a combination of different factors despite the ability to quickly recover from wounds characters with a healing factor are still capable of feeling pain
health effects of pesticides may be acute or delayed in those who are exposed a 2007 systematic review found that most studies on non hodgkin lymphoma and leukemia showed positive associations with pesticide exposure and thus concluded that cosmetic use of pesticides should be decreased strong evidence also exists for other negative outcomes from pesticide exposure including neurological problems birth defects fetal death and neurodevelopmental disorder according to the stockholm convention on persistent organic pollutants 9 of the 12 most dangerous and persistent chemicals are pesticides
the health effects of salt are the conditions associated with the consumption of either too much or too little salt salt is a mineral composed primarily of sodium chloride nacl and is used in food for both preservation and flavor sodium ions are needed in small quantities by most living things as are chloride ions salt is involved in regulating the water content fluid balance of the body the sodium ion itself is used for electrical signaling in the nervous system salt consumption has increased during modern times scientists have become aware of health risks associated with high salt intake including high blood pressure in sensitive individuals therefore health authorities recommend limitations on dietary sodium the united states department of health and human services recommends that individuals consume no more than 1500 – 2300 mg of sodium 3750 – 5750 mg of salt per day depending on age as an essential nutrient sodium is involved in numerous cellular and organ functions salt intake that is too low may also increase risk for cardiovascular disease and early death
the phrase health halo or health halo effect denotes a phenomenon in which there is a halo effect on certain foods or brands causing them to be perceived as healthy the health halo oftentimes results in increased consumption of the product in the halo the health halo has had increased media attention as increased healthy options are being marketed
cardiovascular disease is the principal cause of death in the uae constituting 28 percent of total deaths other major causes are accidents and injuries malignancies and congenital anomalies
health literacy is the ability to obtain read understand and use healthcare information to make appropriate health decisions and follow instructions for treatment there are multiple definitions of health literacy in part because health literacy involves both the context or setting in which health literacy demands are made e g health care media internet or fitness facility and the skills that people bring to that situation rudd moeykens colton 1999 studies reveal that only 12 percent of the adults in the u s have proficient health literacy this means 77 million adults have basic or below basic health literacy these individuals have difficulty with common health tasks including reading the label of a prescribed drug low health literacy reduces the success of treatment and increases the risk of medical error health literacy is essential to promote healthy individuals and communities various interventions such as simplified information and illustrations avoiding jargon teach back methods and encouraging patients questions have improved health behaviors in persons with low health literacy health literacy is of continued and increasing concern for health professionals as it is a primary factor behind health disparities the proportion of adults aged 18 and over in the u s in the year 2010 who reported that their health care providers always explained things so they could understand them was about 60 6 this number increased 1 from 2007 to 2010 the healthy people 2020 initiative of the united states department of health and human services has included it as a pressing new topic with objectives for addressing it in the decade to come society as a whole is responsible for improving health literacy but most importantly the healthcare public health professionals and the public health systems
hearing auditory perception or audition is the ability to perceive sound by detecting vibrations changes in the pressure of the surrounding medium through time through an organ such as the ear
hearing loss also known as hearing impairment is a partial or total inability to hear a deaf person has little to no hearing hearing loss may occur in one or both ears in children hearing problems can affect the ability to learn language and in adults it can cause work related difficulties in some people particularly older people hearing loss can result in loneliness hearing loss can be temporary or permanent hearing loss may be caused by a number of factors including genetics ageing exposure to noise some infections birth complications trauma to the ear and certain medications or toxins a common condition that results in hearing loss is chronic ear infections certain infections during pregnancy such as syphilis and rubella may also cause hearing loss hearing loss is diagnosed when hearing testing finds that a person is unable to hear 25 decibels in at least one ear testing for poor hearing is recommended for all newborns hearing loss can be categorised as mild moderate moderate severe severe or profound half of hearing loss is preventable this includes by immunisation proper care around pregnancy avoiding loud noise and avoiding certain medications the world health organization recommends that young people limit the use of personal audio players to an hour a day in an effort to limit exposure to noise early identification and support are particularly important in children for many hearing aids sign language cochlear implants and subtitles are useful lip reading is another useful skill some develop access to hearing aids however is limited in many areas of the world as of 2013 hearing loss affects about 1 1 billion people to some degree it causes disability in 5 360 to 538 million and moderate to severe disability in 124 million people of those with moderate to severe disability 108 million live in low and middle income countries of those with hearing loss it began in 65 million during childhood those who use sign language and are members of deaf culture see themselves as having a difference rather than an illness most members of deaf culture oppose attempts to cure deafness and some within this community view cochlear implants with concern as they have the potential to eliminate their culture the term hearing impairment is often viewed negatively as it emphasises what people cannot do
heart hand syndromes are a group of rare diseases that manifest with both heart and limb deformities as of july 2013 known heart hand syndromes include holt – oram syndrome berk – tabatznik syndrome heart hand syndrome type 3 brachydactyly long thumb syndrome patent ductus arteriosus bicuspid aortic valve syndrome and heart hand syndrome slovenian type
heart block is a disease or inherited condition that causes a fault within the heart s natural pacemaker due to some kind of obstruction or block in the electrical conduction system of the heart despite the severe sounding name heart block may often cause no symptoms at all in some cases or occasional missed heartbeats in other cases which can cause lightheadedness syncope fainting and palpitations or may require an artificial pacemaker to be implanted depending upon exactly where in the heart conduction is being impaired and how significantly it is affected in severe cases where the heart s ability to control and trigger heartbeats may be completely ineffective or unreliable heart block can usually be treated by inserting an artificial pacemaker a medical device that provides correct electrical impulses to trigger heart beats compensating for the natural pacemaker s unreliability therefore heart block frequently has no effects or mild and occasional effects and is not life threatening in the vast majority of cases and is usually treatable in more serious cases the human heart uses electrical signals to maintain and initiate the regular heart beat in a living person incorrect conduction can lead to mild or serious symptoms depending upon the location of the blockage and how severely conduction is being blocked conduction is initiated by the sinoatrial node sinus node or sa node and then travels to the atrioventricular node av node which also contains a secondary pacemaker that acts as a backup for the sa nodes then to the bundle of his and then via the bundle branches to the point of the apex of the fascicular branches shown in the diagram on the right blockages are therefore classified based on where the blockage occurs namely the sa node sinoatrial block av node av block or avb and at or below the bundle of his intra hisian or infra hisian block respectively infra hisian blocks may occur at the left or right bundle branches bundle branch block or the fascicles of the left bundle branch fascicular block or hemiblock sa and av node blocks are each divided into three degrees with second degree blocks being divided into two types written either type i or ii or type 1 or 2 the term wenckebach block is also used for second degree type 1 blocks of either the sa or av node in addition second degree blocks type 1 and 2 are also sometimes known as mobitz 1 and mobitz 2 clinically speaking the blocks tend to have more serious potential the closer they are to the end of the electrical path the muscles of the heart regulated by the heartbeat and less serious effects the closer they are to the start at the sa node because the potential disruption becomes greater as more of the path is blocked from its end point therefore most of the important heart blocks are av nodal blocks and infra hisian blocks sa blocks are usually of lesser clinical significance since in the event of sa block the av node contains a secondary pacemaker which would still maintain a heart rate of around 40 60 beats per minute sufficient for consciousness and much of daily life in the majority of individuals
heart cancer is an extremely rare form of cancer that is divided into primary tumors of the heart and secondary tumors of the heart
according to the australian heart disease statistics heart disease is a major cause of death in australia nichols 2014 heart disease is an overall term used for any type of heart disorder that affects the heart reducing blood supply to the heart it is also often referred as cardiac disease and coronary heart disease it is generally a lifelong condition where damage to the artery and blood vessel cannot be cured bishop 2010
heart failure hf often referred to as congestive heart failure chf occurs when the heart is unable to pump sufficiently to maintain blood flow to meet the body s needs signs and symptoms commonly include shortness of breath excessive tiredness and leg swelling the shortness of breath is usually worse with exercise while lying down and may wake the person at night a limited ability to exercise is also a common feature chest pain including angina does not typically occur due to heart failure common causes of heart failure include coronary artery disease including a previous myocardial infarction heart attack high blood pressure atrial fibrillation valvular heart disease excess alcohol use infection and cardiomyopathy of an unknown cause these cause heart failure by changing either the structure or the functioning of the heart there are two main types of heart failure heart failure due to left ventricular dysfunction and heart failure with normal ejection fraction depending on whether the ability of the left ventricle to contract is affected or the heart s ability to relax the severity of disease is usually graded by the degree of problems with exercise heart failure is not the same as myocardial infarction in which part of the heart muscle dies or cardiac arrest in which blood flow stops altogether other diseases that may have symptoms similar to heart failure include obesity kidney failure liver problems anemia and thyroid disease the condition is diagnosed based on the history of the symptoms and a physical examination with confirmation by echocardiography blood tests electrocardiography and chest radiography may be useful to determine the underlying cause treatment depends on the severity and cause of the disease in people with chronic stable mild heart failure treatment commonly consists of lifestyle modifications such as stopping smoking physical exercise and dietary changes as well as medications in those with heart failure due to left ventricular dysfunction angiotensin converting enzyme inhibitors or angiotensin receptor blockers along with beta blockers are recommended for those with severe disease aldosterone antagonists or hydralazine with a nitrate may be used diuretics are useful for preventing fluid retention sometimes depending on the cause an implanted device such as a pacemaker or an implantable cardiac defibrillator may be recommended in some moderate or severe cases cardiac resynchronization therapy crt may be suggested or cardiac contractility modulation may be of benefit a ventricular assist device or occasionally a heart transplant may be recommended in those with severe disease despite all other measures heart failure is a common costly and potentially fatal condition in developed countries around 2 of adults have heart failure and in those over the age of 65 this increases to 6 – 10 in the year after diagnosis the risk of death is about 35 after which it decreases to below 10 each year this is similar to the risks with a number of types of cancer in the united kingdom the disease is the reason for 5 of emergency hospital admissions heart failure has been known since ancient times with the ebers papyrus commenting on it around 1550 bce
heart rate variability hrv is the physiological phenomenon of variation in the time interval between heartbeats it is measured by the variation in the beat to beat interval other terms used include cycle length variability rr variability where r is a point corresponding to the peak of the qrs complex of the ecg wave and rr is the interval between successive rs and heart period variability see also heart rate turbulence sinus rhythm methods used to detect beats include ecg blood pressure ballistocardiograms and the pulse wave signal derived from a photoplethysmograph ppg ecg is considered superior because it provides a clear waveform which makes it easier to exclude heartbeats not originating in the sinoatrial node the term nn is used in place of rr to emphasize the fact that the processed beats are normal beats
in trees heart rot is a fungal disease that causes the decay of wood at the center of the trunk and branches fungi enter the tree through wounds in the bark and decay the heartwood the diseased heartwood softens resulting in trees being structurally weaker and prone to breakage heart rot is a major factor in the economics of logging and the natural growth dynamic of many older forests heart rot is prevalent throughout the world affecting all hardwood trees and can be very difficult to prevent a good indication of heart rot is the presence of mushrooms or fungus conks on the tree
heart valve dysplasia is a congenital heart defect which affects the aortic pulmonary mitral and tricuspid heart valves pulmonary valve stenosis and aortic valve stenosis are discussed separately dysplasia of the mitral and tricuspid valves can cause leakage of blood or stenosis dysplasia of the mitral and tricuspid valves also known as the atrioventricular av valves can appear as thickened shortened or notched valves the chordae tendinae can be fused or thickened the papillary muscles can be enlarged or atrophied the cause is unknown but genetics play a large role dogs and cats with tricuspid valve dysplasia often also have an open foramen ovale an atrial septal defect or inflammation of the right atrial epicardium in dogs tricuspid valve dysplasia can be similar to ebstein s anomaly in humans mitral valve stenosis is one of the most common congenital heart defects in cats in dogs it is most commonly found in great danes german shepherd dogs bull terriers golden retrievers newfoundlands and mastiffs tricuspid valve dysplasia is most common in the old english sheepdog german shepherd dog weimaraner labrador retriever great pyrenees and sometimes the papillon it is inherited in the labrador retriever the disease and symptoms are similar to progression of acquired valve disease in older dogs valve leakage leads to heart enlargement arrhythmias and congestive heart failure heart valve dysplasia can be tolerated for years or progress to heart failure in the first year of life diagnosis is with an echocardiogram the prognosis is poor with significant heart enlargement
heartburn also known as acid indigestion is a burning sensation in the central chest or upper central abdomen the pain often rises in the chest and may radiate to the neck throat or angle of the jaw heartburn is usually due to regurgitation of gastric acid gastric reflux into the esophagus and is the major symptom of gastroesophageal reflux disease gerd in about 0 6 of cases it is a symptom of ischemic heart disease
in meteorology a heat burst is a rare atmospheric phenomenon characterized by gusty winds and a rapid increase in temperature and decrease in dew point moisture heat bursts typically occur during night time and are associated with decaying thunderstorms although this phenomenon is not fully understood it is theorized that the event is caused when rain evaporates virga into a parcel of cold dry air high in the atmosphere making the air denser than its surroundings the parcel descends rapidly warming due to compression overshoots its equilibrium level and reaches the surface similar to a downburst recorded temperatures during heat bursts have reached well above 38 ° c 100 ° f sometimes rising by 11 ° c 20 ° f or more within only a few minutes more extreme events have also been documented where temperatures have been reported to exceed 120 ° f 49 ° c however such extreme events have never been officially verified heat bursts are also characterized by extremely dry air and are sometimes associated with very strong even damaging winds
heat edema is a cutaneous condition characterized by dependent edema from vasodilatory pooling heat causes the blood vessels to expand dilate so body fluid moves into the hands or legs by gravity the balance of salt in the body is also a risk factor for heat edema if salt loss is less than normal the increased salt level draws fluid into the hands and legs older adults have an increased risk of heat edema especially if they have other medical conditions that affect their circulation people visiting hot climates from colder climates may also have an increased risk of heat edema
heat illness or heat related illness is a spectrum of disorders due to environmental exposure to heat it includes minor conditions such as heat cramps heat syncope and heat exhaustion as well as the more severe condition known as heat stroke
heat intolerance is a symptom reported by people who feel uncomfortable in hot environments typically the person feels uncomfortably hot and sweats excessively compared to heat illnesses like heatstroke heat intolerance is usually a symptom of endocrine disorders drugs or other medical conditions rather than the result of too much exercise or hot humid weather
in biochemistry heat shock is the effect of subjecting a cell to a higher temperature than that of the ideal body temperature of the organism from which the cell line was derived
heatstroke and heatstrokes redirect here for other uses see heatstroke disambiguation heat stroke also known as sun stroke is a severe heat illness defined as hyperthermia with a body temperature greater than 40 6 ° c 105 1 ° f because of environmental heat exposure with lack of thermoregulation this is distinct from a fever where there is a physiological increase in the temperature set point of the body the term stroke in heat stroke is a misnomer in that it does not involve a blockage or hemorrhage of blood flow to the brain preventive measures include drinking plenty of cool liquids and avoiding excessive heat and humidity especially in unventilated spaces such as parked cars that can overheat quickly treatment requires rapid physical cooling of the body
heat syncope is fainting or dizziness as a result of overheating syncope is the medical term for fainting it is a type of heat illness the basic symptom of heat syncope is fainting with or without mental confusion heat syncope is caused by peripheral vessel dilation resulting in diminished blood flow to the heart and dehydration
heat urticaria presents within five minutes after the skin has been exposed to heat above 43 degrees celsius 109 4 degrees fahrenheit with the exposed area becoming burned stinging and turning red swollen and indurated
heatwork is the combined effect of temperature and time it is important to several industries ceramics glass and metal annealing metal heat treating pyrometric devices can be used to gauge heat work as they deform or contract due to heatwork to produce temperature equivalents within tolerances firing can be undertaken at lower temperatures for a longer period to achieve comparable results when the amount of heatwork of two firings is the same the pieces may look identical but there may be differences not visible such as mechanical strength and microstructure heatwork is taught in material science courses but is not a precise measurement or a valid scientific concept
the heaviside condition named for oliver heaviside 1850 – 1925 is the condition an electrical transmission line must meet in order for there to be no distortion of a transmitted signal also known as the distortionless condition it can be used to improve the performance of a transmission line by adding loading to the cable
heavy np shift is a particular manifestation of shifting where a heavy noun phrase np appears in a position to the right of its canonical position under certain circumstances although the term is coined according to the tradition of transformational grammar which describes the process to be done by movement of the np the term is also used by linguists who do not believe in transformational grammar heaviness is determined by the grammatical complexity ross 1967 may have been the first to look at heavy np shift in some detail
heavy chain disease is a form of paraproteinemia with a proliferation of cells producing immunoglobulin heavy chains this disease is characterized by an excessive production of heavy chains that are short and truncated these heavy chain disease proteins have various deletions mainly in their amino terminal part which causes the heavy chains to lose the ability to form disulfide bonds with the light chains the defect in the immunoglobulins presumably arises during somatic hypermutation deletion of the n terminal part of the heavy chain disease protein leads to aggregation and signaling of the b cell receptor presumably due to the loss of the anti aggregating properties of the light chain
heavy legs french jambes lourdes is an alleged medical condition described as an unpleasant sensation of pain and heaviness in the lower limbs it is of french origin but is occasionally seen elsewhere due to the limited recognition it has received and because of its proliferation in the media and by the alternative health community many medical practitioners believe it is a sign of hypochondriasis the cause may be venous insufficiency or peripheral arterial disease it was described by bbc reporter emma jane kirby as a curiously french complaint the illness you can only get in health conscious france
heck s disease also known as focal or multifocal epithelial hyperplasia is an asymptomatic benign neoplastic condition characterized by multiple white to pinkish papules that occur diffusely in the oral cavity can present with slightly pale smooth or roughened surface morphology it is caused by the human papilloma virus types 13 and 32 it exhibits surface cells with vacuolated cytoplasm around irregular pyknotic nuclei and occasional cells with mitosis like changes within otherwise mature and well differentiated epithelium a distinguishing histologic feature is elongated rete ridges resembling bronze age axe with mitosoid bodies present it was first identified in the aboriginal population over time they will spontaneously regress without treatment possible treatment may be excisional biopsy for lesions of functional or aesthetic concern
the heck reaction also called the mizoroki heck reaction is the chemical reaction of an unsaturated halide or triflate with an alkene in the presence of a base and a palladium catalyst or palladium nanomaterial based catalyst to form a substituted alkene it is named after tsutomu mizoroki and richard f heck heck was awarded the 2010 nobel prize in chemistry which he shared with ei ichi negishi and akira suzuki for the discovery and development of this reaction this reaction was the first example of a carbon carbon bond forming reaction that followed a pd 0 pd ii catalytic cycle the same catalytic cycle that is seen in other pd 0 catalyzed cross coupling reactions the heck reaction is of great importance as it allows one to do substitution reactions on planar sp 2 hybridized carbon atoms the reaction is performed in the presence of an organopalladium catalyst the halide br cl or triflate is an aryl benzyl or vinyl compound and the alkene contains at least one hydrogen and is often electron deficient such as acrylate ester or an acrylonitrile the catalyst can be tetrakis triphenylphosphine palladium 0 palladium chloride or palladium ii acetate the ligand is triphenylphosphine phox or binap the base is triethylamine potassium carbonate or sodium acetate several reviews have been published
the heck matsuda hm reaction is an organic reaction and a type of palladium catalysed arylation of olefins that uses arenediazonium salts as an alternative to aryl halides and triflates the use of arenediazonium salts presents some advantages over traditional aryl halide electrophiles for example the use of phosphines as ligand are not required and thus negating the requirement for anaerobic conditions which makes the reaction more practical and easier to handle additionally the reaction can be performed with or without a base and is often faster than traditional heck protocols hm faster than heck allylic alcohols conjugated alkenes unsaturated heterocycles and unactivated alkenes are capable of being arylated with arenediazonium salts using simple catalysts such as palladium acetate pd oac 2 or tris dibenzylideneacetone dipalladium 0 pd 2 dba 3 at room temperature in air and in benign and conventional solvents olefins in hm reaction in addition to the intermolecular variant of the hm reaction intramolecular cyclization processes have also been developed for the construction of a range of oxygen and nitrogen heterocycles intramolecular hm the catalytic cycle for the heck matsuda arylation reaction has four main steps oxidative addition migratory insertion or carbopalladation syn β elimination and reductive elimination the proposed heck catalytic cycle involving cationic palladium with diazonium salts was reinforced by studies with mass spectrometry esi by correia and co workers these results also show the complex interactions that occur in the coordination sphere of palladium during the heck reaction with arenediazonium salt hm mechanism
heel pad syndrome also known as heel fat pad syndrome heel pad atrophy and heel fat pad atrophy is a pain that occurs in the center of the heel it is typically due to atrophy of the fat pad which makes up the heel risk factors include obesity other conditions with similar symptoms include plantar fasciitis treatment includes rest pain medication and heel cups it becomes more common with age
heel stick wounds are a cutaneous condition characterized by a break in the skin caused by neonatal heel prick
heerfordt s syndrome also referred to as uveoparotid fever heerfordt – mylius syndrome heerfordt – waldenström syndrome and waldenström ’ s uveoparotitis is a rare manifestation of sarcoidosis the symptoms include inflammation of the eye uveitis swelling of the parotid gland chronic fever and in some cases palsy of the facial nerves
in discrete geometry and discrepancy theory the heilbronn triangle problem is a problem of placing points within a region in the plane in order to avoid triangles of small area it is named after hans heilbronn who conjectured prior to 1950 that this smallest triangle area is necessarily at most inversely proportional to the square of the number of points heilbronn s conjecture was proven false but the asymptotic growth rate of the minimum triangle area remains unknown
heiligenschein german for ‘ halo ’ or ‘ aureola ’ literally ‘ holy or saintly appearance ’ pronounced ˈhaɪlɪɡənˌʃaɪn see also the article for halo the optical phenomenon is an optical phenomenon which creates a bright spot around the shadow of the viewer s head in photogrammetry and remote sensing it is more commonly known as the hotspot and is due to the reduction in the proportion of shadows viewed at angles close to the backscatter direction it may also be created when the surface on which the shadow falls has special optical characteristics both dry dusty surfaces and dewy grass are known to exhibit these characteristics nearly spherical dew droplets act as lenses to focus the light on the surface beneath them some of this light backscatters in the direction of the sunlight as it passes back through the dew droplet this makes the antisolar point appear the brightest the glory creates a similar halo effect by a different mechanism
in mathematics the heine – cantor theorem named after eduard heine and georg cantor states that if f m → n is a continuous function between two metric spaces and m is compact then f is uniformly continuous an important special case is that every continuous function from a bounded closed interval to the real numbers is uniformly continuous
a heinrich event is a natural phenomenon in which large armadas of icebergs break off from glaciers and traverse the north atlantic first described by marine geologist hartmut heinrich they occurred during the past glacial periods or ice ages and are particularly well documented for the last glacial period the icebergs contained rock mass which has been eroded by the glaciers and as they melted this matter was dropped onto the sea floor as ice rafted debris abbreviated to ird the icebergs melting caused prodigious amounts of fresh water to be added to the north atlantic such inputs of cold and fresh water may well have altered the density driven thermohaline circulation patterns of the ocean and often coincide with indications of global climate fluctuations various mechanisms have been proposed to explain the cause of heinrich events most of which implies instability of the massive laurentide ice sheet a continental glacier covering north america during the last glacial period other northern hemisphere ice sheets were potentially involved as well scandinavia iceland greenland however the initial cause of this instability is still debated
helicobacter cellulitis is a cutaneous condition caused by helicobacter cinaedi h cinaedi can cause cellulitis and bacteremia in immunocompromised people
helicobacter pylori previously campylobacter pylori is a gram negative microaerophilic bacterium found usually in the stomach it was identified in 1982 by australian scientists barry marshall and robin warren who found that it was present in a person with chronic gastritis and gastric ulcers conditions not previously believed to have a microbial cause it is also linked to the development of duodenal ulcers and stomach cancer however over 80 of individuals infected with the bacterium are asymptomatic and it may play an important role in the natural stomach ecology more than 50 of the world s population harbor h pylori in their upper gastrointestinal tract infection is more prevalent in developing countries and incidence is decreasing in western countries h pylori s helical shape from which the genus name is derived is thought to have evolved to penetrate the mucoid lining of the stomach
hells gate is an abrupt narrowing of british columbia s fraser river located immediately downstream of boston bar in the southern fraser canyon the towering rock walls of the fraser river plunge toward each other forcing the waters through a passage only 35 metres 115 ft wide it is also the name of the rural locality at the same location for centuries the narrow passage has been a popular fishing ground for aboriginal communities in the area european settlers also began to congregate there in the summer months to fish eventually the fraser canyon became a route used by gold rush miners wishing to access the upper fraser gold bearing bars and the upper country beyond up the fraser and the thompson in the 1880 s the canadian pacific railway cpr built a transcontinental railroad that passed along the bank at hells gate and in 1911 the canadian northern railway cnr began constructing a second track in 1914 a large rockslide triggered by cnr construction fell into the river at hells gate obstructing the passage of pacific salmon needing to swim upstream to spawn salmon had difficulty passing through the now swifter water and were appearing in increased numbers downstream below the hells gate passage and in tributary rivers and streams that they had not inhabited before in the winter of 1914 debris removal began and in 1915 the river was pronounced clear however many biologists claim that the river was permanently altered and the salmon migration would forever remain disturbed by the slide a decrease in fraser salmon catalyzed tension between the government of canada and the aboriginal peoples of the area not only did the debris clearing operation impede their access to the river but the government imposed new fishing restrictions such as a four day per week limit in an attempt to preserve the salmon population ultimately the slide and subsequent restrictions proved very damaging for the aboriginal fishing economy the canadian and united states governments formed the pacific salmon convention psc of 1937 which created the international pacific salmon fisheries commission ipsfc now the pacific salmon commission the ipsfc carried out extensive research and as based on their findings they recommended that fishways be constructed to help migrating salmon pass through hells gate building of the fishways began in 1944 this decision sparked a major controversy in the pacific fisheries and research community which became divided along national lines american william thompson head researcher for the ipsfc was criticized by canadian zoologist william ricker who claimed that the ipsfc research was unreliable and that fishways were not a means to preserving fraser salmon ricker believed that hells gate posed no threat to migrating salmon and that commercial over fishing did he held that stringent regulations should be placed on fishing for fraser salmon the fishways at hells gate became a tourist attraction in the 1970 s among the attractions for tourists are the airtram food outlets observation decks and an educational fisheries exhibit
helmholtz resonance or wind throb is the phenomenon of air resonance in a cavity such as when one blows across the top of an empty bottle the name comes from a device created in the 1850 s by hermann von helmholtz the helmholtz resonator which he used to identify the various frequencies or musical pitches present in music and other complex sounds
the helmholtz – kohlrausch effect after hermann von helmholtz and rudolf kohlrausch is an entoptic phenomenon wherein the intense saturation of spectral hue is perceived as part of the color s luminance this brightness increase by saturation which grows stronger as saturation increases might better be called chromatic luminance since white or achromatic luminance is the standard of comparison it appears in both self luminous and surface colors although it is most pronounced in spectral lights
helminthiasis plural helminthiases also known as worm infection is any macroparasitic disease of humans and other animals in which a part of the body is infected with parasitic worms known as helminths there are numerous species of these parasites which are broadly classified into tapeworms flukes and roundworms they often live in the gastrointestinal tract of their hosts but they may also burrow into other organs where they induce physiological damage soil transmitted helminthiasis and schistosomiasis are the most important helminthiases and are among the neglected tropical diseases this group of helmianthiases have been targeted under the joint action of the world s leading pharmaceutical companies and non governmental organizations through a project launched in 2012 called the london declaration on neglected tropical diseases which aims to control or eradicate certain neglected tropical diseases by 2020 helminthiasis has been found to result in poor birth outcome poor cognitive development poor school and work performance poor socioeconomic development and poverty chronic illness malnutrition and anemia are further examples of secondary effects soil transmitted helminthiases are responsible for parasitic infections in as much as a quarter of the human population worldwide one well known example of soil transmitted helminthiases is ascariasis
silver scurf is a plant disease that is caused by the plant pathogen helminthosporium solani this pathogen is a fungus which is specific to infecting only potato tubers silver scurf is a blemish disease meaning the effect it has on tubers is mostly cosmetic and affects “ fresh market processing and seed tuber potatoes there are some reports of it affecting development meaning growth and tuber yield this is caused by light brown lesions which in turn change the permeability of tuber skin and then it causes tuber shrinkage and water loss which finally causes weight loss the disease has become economically important because silver scurf affected potatoes for processing and direct consumption have been rejected by the industry the disease cycle can be divided into two stages field and storage it is mainly a seed borne disease and the primary source of inoculum is mainly infected potato seed tubers symptoms develop and worsen in storage because the conditions are conducive to sporulation the ideal conditions for the spread of this disease are high temperatures and high humidity there are also many cultural practices that favor spread and development luckily there are multiple ways to help control the disease
a helpmate is a type of chess problem in which both sides cooperate in order to achieve the goal of checkmating black in a helpmate in n moves black moves first then white each side moving n times to culminate in white s nth move checkmating black in a helpmate in two for example sometimes abbreviated h 2 the solution consists of a black move a white move a second black move then a second white move giving checkmate although the two sides cooperate all moves must be legal according to the rules of chess the example problem to the right is a helpmate in eight or h 8 by z maslar published in die schwalbe in 1981 the solution is recall that in helpmate solutions black s move is given first 1 kf 3 kd 3 2 bb 3 kc 3 3 ke 4 kd 2 4 kd 4 ke 2 5 kc 3 nb 4 6 kb 2 kd 2 7 ka 1 kc 1 8 ba 2 nc 2
hemangioblastomas or haemangioblastomas see spelling differences capilliary hemangioblastomas are tumors of the central nervous system that originate from the vascular system usually during middle age sometimes these tumors occur in other sites such as the spinal cord and retina they may be associated with other diseases such as polycythemia increased blood cell count pancreatic cysts and von hippel lindau syndrome vhl syndrome hemangioblastomas are most commonly composed of stromal cells in small blood vessels and usually occur in the cerebellum brain stem or spinal cord they are classed as grade one tumors under the world health organization s classification system
hemangioendothelioma is used to describe a group of vascular neoplasms that may be considered benign as well as malignant depending on the specific group member s activity
an infantile hemangioma ih is one of the most common benign tumors of infancy and occurs in approximately 5 – 10 of infants the word hemangioma comes from the greek haema αίμα blood angeio αγγείο vessel oma ωμα tumor infantile hemangiomas are benign vascular tumors composed of an increased number of unique endothelial cells that line blood vessels they occur more frequently in female premature and low birth weight infants infantile hemangiomas usually appear within the first weeks of life and grow most rapidly during the first three to six months of life for most hemangiomas 80 of infantile hemangioma size is generally reached by 3 months of age usually growth and proliferation is complete and involution commences by twelve months of age however involution occurs slowly over many years with a majority of infantile hemangioma regression occurring by five years of age although infantile hemangiomas spontaneously regress over time some may leave residual redundant fibrofatty tissue scar residual telangiectasia or pigmentary changes
a hemangiopericytoma hpc is a type of soft tissue sarcoma that originates in the pericytes in the walls of capillaries when inside the nervous system although not strictly a meningioma tumor it is a meningeal tumor with a special aggressive behavior it was first characterized in 1942
hemangiosarcoma is a rapidly growing highly invasive variety of cancer occurring almost exclusively in dogs and rarely in cats it is a sarcoma arising from the lining of blood vessels that is blood filled channels and spaces are commonly observed microscopically a frequent cause of death is the rupturing of this tumor causing the patient to rapidly bleed to death the term angiosarcoma when used without modifier usually refers to hemangiosarcoma however glomangiosarcoma 8710 3 and lymphangiosarcoma 9170 3 are distinct conditions hemangiosarcomas are commonly associated with toxic exposure to thorium dioxide thorotrast vinyl chloride and arsenic
hemarthrosis or haemarthrosis plural h a emarthroses is a bleeding into joint spaces it is a common feature of hemophilia the presence of it excludes the idiopathic thrombocytopenic purpura itp
hematemesis or haematemesis is the vomiting of blood the source is generally the upper gastrointestinal tract typically above the suspensory muscle of duodenum patients can easily confuse it with hemoptysis coughing up blood although the latter is more common hematemesis is always an important sign
hematidrosis also calledblood sweat is a very rare condition in which a human sweats blood the term is from greek haima haimatos αἷμα αἵματος meaning blood and hidrōs ἱδρώς meaning sweat
a hematocele is a collection of blood in a body cavity the term most commonly refers to the collection of blood in the tunica vaginalis around the testicle hematoceles can also occur in the abdominal cavity and other body cavities
haematochezia or hematochezia from greek αἷμα blood and χέζειν to defaecate is the passage of fresh blood through the anus usually in or with stools contrast with melena haematochezia is commonly associated with lower gastrointestinal bleeding but may also occur from a brisk upper gastrointestinal bleed the difference between hematochezia and rectorrhagia is that in the latter rectal bleeding is not associated with defecation instead it is associated with expulsion of fresh bright red blood without stools the phrase bright red blood per rectum brbpr is associated with hematochezia and rectorrhagia it is also important to differentiate from hematopapyrus blood on the toilet paper noticed when wiping
hematocolpos is a medical condition in which the vagina fills with menstrual blood it is often caused by the combination of menstruation with an imperforate hymen it is sometimes seen in robinow syndrome uterus didelphys or other congenital conditions a related disorder is hematometra where the uterus fills with menstrual blood it presents after puberty as primary amenorrhoea recurrent pelvic pain with a pelvic mass this can be caused by a congenital stenosis of the cervix or by a complication of a surgical treatment
hematologic diseases are disorders which primarily affect the blood hematology includes the study of these disorders
a hematoma is a localized collection of blood outside the blood vessels usually in liquid form within the tissue an ecchymosis commonly although erroneously called a bruise is a hematoma of the skin larger than 10 mm it is not to be confused with hemangioma which is an abnormal buildup of blood vessels in the skin or internal organs
hematometra or hemometra is a medical condition involving collection or retention of blood in the uterus it is most commonly caused by an imperforate hymen or a transverse vaginal septum
hematopoietic ulcers are those occurring with sickle cell anemia congenital hemolytic anemia polycythemia vera thrombocytopenic purpura macroglobulinemia and cryoglobulinemia
hematosalpinx sometimes also hemosalpinx is a medical condition involving bleeding into the fallopian tubes
hematospermia the presence of blood in semen is most often a benign symptom among men age 40 or older hematospermia is a slight predictor of cancer typically prostate cancer no specific cause is found in up to 70 of cases
in medicine hematuria or haematuria is the presence of red blood cells erythrocytes in the urine it may be idiopathic and or benign or it can be a sign that there is a kidney stone or a tumor in the urinary tract kidneys ureters urinary bladder prostate and urethra ranging from trivial to lethal if white blood cells are found in addition to red blood cells then it is a signal of urinary tract infection occasionally hemoglobinuria is used synonymously although more precisely it refers only to hemoglobin in the urine
hemeralopia from greek ημέρα hemera day and αλαός alaos blindness is the inability to see clearly in bright light and is the exact opposite of nyctalopia night blindness hemera was the greek goddess of day and nyx was the goddess of night however it has been used in an opposite sense by many non english speaking doctors it can be described as insufficient adaptation to bright light it is also called heliophobia and day blindness in hemeralopia daytime vision gets worse characterised by photoaversion dislike avoidance of light rather than photophobia eye discomfort pain in light which is typical of inflammations of eye nighttime vision largely remains unchanged due to the use of rods as opposed to cones during the day which are affected by hemeralopia and in turn degrade the daytime optical response hence many patients feel they see better at dusk than in daytime
the hemetsberger indole synthesis also called the hemetsberger – knittel synthesis is a chemical reaction that thermally decomposes a 3 aryl 2 azido propenoic ester into an indole 2 carboxylic ester the hemetsberger indole synthesis yields are typically above 70 however this is not a popular reaction due to the lack of stability and difficulty in synthesizing the starting material
hemianopsia or hemianopia is a decreased vision or blindness anopsia in half the visual field usually on one side of the vertical midline the most common causes of this damage are stroke brain tumor and trauma this article deals only with permanent hemianopia and not with transitory temporary hemianopia as identified by william wollaston prs in 1824 ganzzaniga ivry and mangun cognitive neuroscience the biology of the mind w w norton and company new york and london p 9
ballismus or ballism called hemiballismus or hemiballism in its unilateral form is a very rare movement disorder it is a type of chorea caused in most cases by a decrease in activity of the subthalamic nucleus of the basal ganglia resulting in the appearance of flailing ballistic undesired movements of the limbs it can also appear rarely due to certain metabolic abnormalities it is a rare movement disorder being 500 times rarer than parkinson s disease hemiballismus can cause significant disability symptoms can decrease during sleep
hemicrania continua hc is a persistent unilateral headache that responds to indomethacin it is usually unremitting but rare cases of remission have been documented hemicrania continua is considered a primary headache disorder meaning that it is not caused by another condition
hemifacial hypertrophy also termed facial hemihypertrophy facial hemihyperplasia or friedreich s disease abbreviated as hfh is rare congenital disease characterized by unilateral enlargement of the head and teeth it is classified as true hfh thfh with unilateral enlargement of the viscerocranium and partial hfh phfh in which not all structures are enlarged hemifacial hypertrophy can cause a wide spectrum of defects or may involve only muscle or bone it is usually treated surgically it is believed to be a minor form of hemihypertrophy
hemifacial microsomia is a congenital disorder that affects the development of the lower half of the face most commonly the ears the mouth and the mandible it can occur on one side of the face or both if severe it can lead to difficulties in breathing obstructing the trachea and requiring a tracheotomy it is the second most common facial birth defect after clefts with an incidence in the range of 1 in 3500 to 4500 hemifacial microsomia shares many similarities with treacher collins syndrome
hemifacial spasm hfs is a rare neuromuscular disease characterized by irregular involuntary muscle contractions spasms on one side hemi of the face facial the facial muscles are controlled by the facial nerve seventh cranial nerve which originates at the brainstem and exits the skull below the ear where it separates into five main branches this disease takes two forms typical and atypical in typical form the twitching usually starts in the lower eyelid in orbicularis oculi muscle as time progresses it spreads to the whole lid then to the orbicularis oris muscle around the lips and buccinator muscle in the cheekbone area the reverse process of twitching occurs in atypical hemifacial spasm twitching starts in orbicularis oris muscle around the lips and buccinator muscle in the cheekbone area in the lower face then progresses up to the orbicularis oculi muscle in the eyelid as time progresses the most common form is the typical form and atypical form is only seen in about 2 – 3 of patients with hemifacial spasm the incidence of hemifacial spasm is approximately 0 8 per 100 000 persons this disorder occurs in both men and women although it affects middle aged or elderly women more frequently hemifacial spasm is much more common in some asian populations it may be caused by a facial nerve injury a tumor or it may have no apparent cause individuals with spasm on both sides of the face are very rare
hemihydranencephaly is a severe cephalic disorder characterized by complete or almost complete absence of the cerebral cortex with preservation of meninges basal ganglia pons medulla cerebellum and falx it is a special type of hydranencephaly it is a very rare disease as it stands only 7 cases have been reported
hemihyperplasia – multiple lipomatosis syndrome is a cutaneous condition characterized by multiple lipomas in association with asymmetric but non progressive and non distorting overgrowth cutaneous capillary malformations and thickened plantar skin with prominent creases
hemihypertrophy now more commonly referred to as hemihyperplasia in the medical literature is a condition in which one side of the body or a part of one side of the body is larger than the other to an extent considered greater than the normal variation as it is difficult to establish a set clinical criteria for diagnosis of hemihyperplasia the dictum is often used that the clinician should be able to see the asymmetry from the end of the bed hemihyperplasia is a congenital overgrowth disorder and the asymmetry can range from mild to severe it is important to establish a diagnosis because hemihyperplasia is associated with an increased risk for embryonal tumors mainly wilms tumor and hepatoblastoma due to the heightened tumor risk there is a tumor screening protocol that is recommended for all children with isolated hemihyperplasia and beckwith wiedemann syndrome some of the other syndromes associated with hemihyperplasia may also follow this tumor surveillance protocol the recommended tumor surveillance protocol is 1 any child with suspected isolated hemihyperplasia should be referred to a clinical geneticist for evaluation 2 abdominal ultrasound every 3 months until 7 years 3 serum alpha fetoprotein measurement every 3 months until 4 years 4 daily caretaker abdominal examination at the discretion of the provider parent children with hemihypertrophy may also develop scoliosis a curvature of the spine there are two main surgical options for the treatment of hemihypertrophy shortening and lengthening epiphysiodesis which involves removing part of the growth plate of the longer leg allowing the shorter leg to catch up is performed on patients still able to grow bone resection is performed on patients who have no growth left and involves removing part of the bone leg lengthening procedures are more painful involving the insertion of pins to be turned moving parts of the bone apart ilizarov s method this process is reserved mainly for patients with a discrepancy greater than 4 cm although some leg lengthening procedures are now done cosmetically non surgical options include attachment of a lift to the shoe allowing the patient to walk normally hemifacial hyperplasia is believed to be a minor form of hemihypertrophy
hemimotor neglect or simply motor neglect is a neuropsychological condition that occurs after damage to one hemisphere of the brain characterized by a failure of spontaneous use of upper and lower limbs on one side of body it occurs in the absence of paralysis pyramidal syndromes extrapyramidal symptoms strength and primary sensory deficit
hemiparesis is unilateral paresis that is weakness of the entire left or right side of the body hemi means half hemiplegia is in its most severe form complete paralysis of half of the body hemiparesis and hemiplegia can be caused by different medical conditions including congenital causes trauma tumors or stroke
hemispatial neglect also called hemiagnosia hemineglect unilateral neglect spatial neglect contralateral neglect unilateral visual inattention hemi inattention neglect syndrome or contralateral hemispatialagnosia is a neuropsychological condition in which after damage to one hemisphere of the brain is sustained a deficit in attention to and awareness of one side of space is observed it is defined by the inability of a person to process and perceive stimuli on one side of the body or environment where that inability is not due to a lack of sensation hemispatial neglect is very commonly contralateral to the damaged hemisphere but instances of ipsilesional neglect on the same side as the lesion have been reported
hemoglobin c abbreviated as hb c or hbc is an abnormal hemoglobin in which substitution of a glutamic acid residue with a lysine residue at the 6 th position of the β globin chain has occurred e 6 k substitution
hemoglobin d punjab is one of the sub variants of hemoglobin d a variant of hemoglobin found in human blood it is so named because of its higher prevalence in the punjab region of india and pakistan it is also the most frequent abnormal hemoglobin variant in xinjiang uyghur autonomous region of china studies indicate that hemoglobin d punjab accounts for over 55 of the total hemoglobin variants there hemoglobin d punjab was first discovered in the early 1950 s in a mixed british and american family of indian origin from the los angeles area hence it is also sometimes called “ d los angeles ” hemoglobin d is the 4 th most common hemoglobin variant it developed as a response to the selective pressures of malaria in these regions of asia
the βe mutation affects β gene expression creating an alternate splicing site in the mrna at codons 25 27 of the β globin gene through this mechanism there is a mild deficiency in normal β mrna and production of small amounts of anomalous β mrna the reduced synthesis of β chain may cause β thalassemia also this hemoglobin variant has a weak union between α and β globin causing instability when there is a high amount of oxidant
hemoglobin h disease is a type of alpha thalassemia caused by impaired production of three of the four alpha globins coded by genes hba 1 and hba 2
hemoglobinemia british haemoglobinaemia is a medical condition in which there is an excess of hemoglobin in the blood plasma this is an effect of intravascular hemolysis in which hemoglobin separates from red blood cells a form of anemia hemoglobinemia can be caused by intrinisic or extrinsic factors when hemoglobinemia is internally caused it is a result of recessive genetic defects that cause the red blood cells to lyse letting the hemoglobin spill out of the cell into the blood plasma in externally caused hemoglobinemia an outside attacker acts as an antibody against the red blood cells this can cause the cells to be destroyed and their hemoglobin released
in medicine hemoglobinuria or haemoglobinuria is a condition in which the oxygen transport protein hemoglobin is found in abnormally high concentrations in the urine the condition is often associated with hemolytic anemia in which red blood cells rbcs are destroyed thereby increasing levels of free plasma hemoglobin excess hemoglobin is filtered by the kidneys which excrete it into the urine giving urine a purple color
hemolytic uremic syndrome or haemolytic uraemic syndrome abbreviated hus is a disease characterized by hemolytic anemia anemia caused by destruction of red blood cells acute kidney failure uremia and a low platelet count thrombocytopenia it predominantly but not exclusively affects children most cases are preceded by an episode of infectious sometimes bloody diarrhea acquired as a foodborne illness or from a contaminated water supply caused by e coli o 157 h 7 other non o 157 h 7 e coli serotypes shigella and campylobacter a variety of viruses have also been implicated as a causative agent it is now the most common cause of acquired acute renal failure in childhood it is a medical emergency and carries a 5 – 10 mortality rate of the remainder the majority recover without major consequences but a small proportion develop chronic kidney disease meaning at some point they will likely become reliant on renal replacement therapy dialysis or transplantation the primary target appears to be the vascular endothelial cell this may explain the pathogenesis of hus in which a characteristic renal lesion is capillary microangiopathy hus was first defined as a syndrome in 1955 the more common form of the disease shiga like toxin producing e coli hus stec hus is triggered by the infectious agent e coli o 157 h 7 and several other non o 157 h 7 e coli serotypes certain shiga toxin secreting strains of shigella dysenteriae can also cause hus approximately 5 of cases are classified as pneumococcal hus which results from infection by streptococcus pneumoniae the agent that causes traditional lobar pneumonia there is also a rare chronic and severe form known as atypical hemolytic uremic syndrome ahus which is caused by genetic defects resulting in chronic uncontrolled complement activation both stec hus and ahus cause endothelial damage leukocyte activation platelet activation and widespread inflammation and multiple thromboses in the small blood vessels a condition known as systemic thrombotic microangiopathy tma which leads to thrombotic events as well as organ damage failure and death
hemolytic anemia or haemolytic anaemia is a form of anemia due to hemolysis the abnormal breakdown of red blood cells rbcs either in the blood vessels intravascular hemolysis or elsewhere in the human body extravascular it has numerous possible consequences ranging from relatively harmless to life threatening the general classification of hemolytic anemia is either inherited or acquired treatment depends on the cause and nature of the breakdown symptoms of hemolytic anemia are similar to other forms of anemia fatigue and shortness of breath but in addition the breakdown of red cells leads to jaundice and increases the risk of particular long term complications such as gallstones and pulmonary hypertension
hemolytic disease of the newborn also known as hemolytic disease of the fetus and newborn hdn hdfn or erythroblastosis fetalis is an alloimmune condition that develops in a fetus when the igg molecules one of the five main types of antibodies produced by the mother pass through the placenta among these antibodies are some which attack antigens on the red blood cells in the fetal circulation breaking down and destroying the cells hemolysis the fetus can develop reticulocytosis and anemia this fetal disease ranges from mild to very severe and fetal death from heart failure hydrops fetalis can occur when the disease is moderate or severe many erythroblasts immature red blood cells are present in the fetal blood and so these forms of the disease can be called erythroblastosis fetalis or erythroblastosis foetalis hdfn represents a breach of immune privilege for the fetus or some other form of impairment of the immune tolerance of pregnancy various types of hdfn are classified by which alloantigen provokes the response in order of incidence the types include abo anti rhd anti rhe anti rhc anti rhe anti rhc multiantigen combinations and anti kell
in abo hemolytic disease of the newborn also known as abo hdn maternal igg antibodies with specificity for the abo blood group system pass through the placenta to the fetal circulation where they can cause hemolysis of fetal red blood cells which can lead to fetal anemia and hdn in contrast to rh disease about half of the cases of abo hdn occur in a firstborn baby and abo hdn does not become more severe after further pregnancies the abo blood group system is the best known surface antigen system expressed on a wide variety of human cells for caucasian populations about one fifth of all pregnancies have abo incompatibility between the fetus and the mother but only a very small minority develop symptomatic abo hdn the latter typically only occurs in mothers of blood group o because they can produce enough igg antibodies to cause hemolysis although very uncommon cases of abo hdn have been reported in infants born to mothers with blood groups a and b
hemolytic disease of the newborn anti kell 1 is the third most common cause of severe hemolytic disease of the newborn hdn after rh disease and abo incompatibility anti kell 1 is becoming relatively more important as prevention of rh disease is also becoming more effective hemolytic disease of the newborn anti kell 1 is caused by a mismatch between the kell antigens of the mother and fetus about 91 of the population are kell 1 negative and about 9 are kell 1 positive a fraction of a percentage are homozygous for kell 1 therefore about 4 5 of babies born to a kell 1 negative mother are kell 1 positive the disease results when maternal antibodies to kell 1 are transferred to the fetus across the placental barrier breaching immune privilege these antibodies can cause severe anemia by interfering with the early proliferation of red blood cells as well as causing alloimmune hemolysis very severe disease can occur as early as 20 weeks gestation hydrops fetalis can also occur early the finding of anti kell antibodies in an antenatal screening blood test indirect coombs test is an indication for early referral to a specialist service for assessment management and treatment
hemolytic disease of the newborn anti rhe is caused by the anti rhe antibody of the rh blood group system the anti rhe antibody can be naturally occurring or arise following immune sensitization after a blood transfusion or pregnancy the anti rhe antibody is quite common especially in the rh genotype cde cde it usually only causes a mild hemolytic disease but very rarely can cause a severe condition in the newborn it can occur with other antibodies usually the anti rhc antibody which can also cause a severe hemolytic disease
hemolytic disease of the newborn anti rhc can range from a mild to a severe disease it is the third most common cause of severe hdn rh disease is the most common and hemolytic disease of the newborn anti kell is the second most common cause of severe hdn it occurs more commonly in women who are rh d negative
hemopericardium refers to blood in the pericardial sac of the heart it is clinically similar to a pericardial effusion and depending on the volume and rapidity with which it develops may cause cardiac tamponade the condition can be caused by full thickness necrosis death of the myocardium heart muscle after myocardial infarction chest trauma and by over prescription of anticoagulants other causes include ruptured aneurysm of sinus of valsalva and other aneurysms of the aortic arch hemopericardium can be diagnosed with a chest x ray or a chest ultrasound and is most commonly treated with pericardiocentesis while hemopericardium itself is not deadly it can lead to cardiac tamponade a condition that is fatal if left untreated
hemoperitoneum sometimes also hematoperitoneum is the presence of blood in the peritoneal cavity the blood accumulates in the space between the inner lining of the abdominal wall and the internal abdominal organs hemoperitoneum is generally classified as a surgical emergency in most cases urgent laparotomy is needed to identify and control the source of the bleeding in selected cases careful observation may be permissible the abdominal cavity is highly distensible and may easily hold greater than five liters of blood or more than the entire circulating blood volume for an average sized individual therefore large scale or rapid blood loss into the abdomen will reliably induce hemorrhagic shock and if untreated may rapidly lead to death
hemophagocytic lymphohistiocytosis hlh also known as haemophagocytic lymphohistiocytosis british spelling and hemophagocytic or haemophagocytic syndrome is an uncommon hematologic disorder it is a life threatening disease of severe hyperinflammation caused by uncontrolled proliferation of activated lymphocytes and macrophages characterised by proliferation of morphologically benign lymphocytes and macrophages that secrete high amounts of inflammatory cytokines it is classified as one of the cytokine storm syndromes
hemopneumothorax or haemopneumothorax is a medical term describing the combination of two conditions pneumothorax or air in the chest cavity and hemothorax also called hæmothorax or blood in the chest cavity a hemothorax pneumothorax or both can occur if the chest wall is punctured to understand the ramifications of this it is important to have an understanding of the role of the pleural space the pleural space is located anatomically between the visceral membrane which is firmly attached to the lungs and the parietal membrane which is firmly attached to the chest wall aka ribcage and intercostal muscles muscles between the ribs the pleural space contains pleural fluid this fluid holds the two membranes together by surface tension as much as a drop of water between two sheets of glass prevents them from separating because of this when the intercostal muscles move the ribcage outward the lungs are pulled out as well dropping the pressure in the lungs and pulling air into the bronchi when we breathe in the pleural space is maintained in a constant state of negative pressure in comparison to atmospheric pressure if the chest wall and thus the pleural space is punctured blood air or both can enter the pleural space air blood rushes into the space in order to equalise the pressure with that of the atmosphere as a result the fluid is disrupted and the two membranes no longer adhere to each other when the rib cage moves out it no longer pulls the lungs with it thus the lungs cannot expand the pressure in the lungs never drops and no air is pulled into the bronchi respiration is not possible the affected lung which has a great deal of elastic tissue shrivels in what is referred to as a collapsed lung
hemorrhagic gastroenteritis hge is a disease of dogs characterized by sudden vomiting and bloody diarrhea the symptoms are usually severe and hge can be fatal if not treated hge is most common in young adult dogs of any breed but especially small dogs such as the toy poodle and miniature schnauzer it is not contagious
hemorrhagic infarcts are infarcts commonly caused by occlusion of veins with red blood cells entering the area of the infarct or an artery occlusion of an organ with collaterals or dual circulation this is commonly seen in brain lungs liver and the gi tract areas referred to as having loose tissue or dual circulation loose textured tissue allows red blood cells released from damaged vessles to diffuse through the necrotic tissue white infarcts can become hemorrhagic with reperfusion compare to anemic infarct hemorrhagic infarction is also associated with testicular torsion
hemorrhagic smallpox sometimes called bloody pox fulminant smallpox and blackpox is a severe and rare form of smallpox and is usually fatal like all forms of smallpox it is caused by the variola virus it is characterized by an incubation period of 7 to 14 days it has two stages the first begins with fever headache chills nausea vomiting and severe muscle aches the skin flushes in a deep purple uneven pattern across the face the early stage is often mistaken for measles the late stage is characterized by the appearance of small blisters resembling a severe form of chickenpox these small blisters then flatten until they are even with the skin and change into reddish lesions similar to those seen in measles the skin then turns a deep purple lesions appear inside the mouth and active bleeding from oral and nasal mucous membranes is common this is followed by active bleeding in the gastrointestinal tract and blood appears in the stool and urine blood studies resemble the clinical values of disseminated intravascular coagulation
hemorrhoids also spelled haemorrhoids are vascular structures in the anal canal in their normal state they are cushions that help with stool control they become a disease when swollen or inflamed the unqualified term hemorrhoid is often used to mean the disease the signs and symptoms of hemorrhoids depend on the type present internal hemorrhoids usually present with painless bright red rectal bleeding when defecating external hemorrhoids often result in pain and swelling in the area of the anus if bleeding occurs it is usually darker symptoms frequently get better after a few days a skin tag may remain after the healing of an external hemorrhoid while the exact cause of hemorrhoids remains unknown a number of factors which increase pressure in the abdomen are believed to be involved this may include constipation diarrhea and sitting on the toilet for a long time hemorrhoids are also more common during pregnancy diagnosis is made by looking at the area many people incorrectly refer to any symptom occurring around the anal area as hemorrhoids and serious causes of the symptoms should be ruled out colonoscopy or sigmoidoscopy is reasonable to confirm the diagnosis and rule out more serious causes often no specific treatment is needed initial measures consists of increasing fiber intake drinking fluids to maintain hydration nsaids to help with pain and rest medicated creams applied to the area are poorly supported by evidence a number of minor procedures may be performed if symptoms are severe or do not improve with conservative management surgery is reserved for those who fail to improve following these measures half to two thirds of people have problems with hemorrhoids at some point in their lives males and females are affected about equally commonly hemorrhoids affect people most often between 45 and 65 years of age it is more common among the wealthy outcomes are usually good the first known mention of the disease is from a 1700 bc egyptian papyrus
hemoscrotum or haemoscrotum in british english is a condition in which blood accumulates inside the scrotum hemoscrotum can follow trauma such as a straddle injury or can be a complication of surgery it is often accompanied by testicular pain it has been reported in patients with hemophilia and following catheterization of the femoral artery if the diagnosis is not clinically evident transillumination with a penlight against the scrotum will show a non translucent fluid inside the scrotum ultrasound imaging may also be useful in confirming the diagnosis in severe or non resolving cases surgical incision and drainage may be required to prevent recurrence following surgical drainage a drain may be left at the surgical site
hemosiderin hyperpigmentation is pigmentation due to deposits of hemosiderin and occurs in purpura hemochromotosis hemorrhagic diseases and stasis dermatitis
hemosiderosis ame or haemosiderosis bre is a form of iron overload disorder resulting in the accumulation of hemosiderin types include transfusion hemosiderosis idiopathic pulmonary hemosiderosis transfusional diabetes hemosiderin deposition in the lungs is often seen after diffuse alveolar hemorrhage which occurs in diseases such as goodpasture s syndrome granulomatosis with polyangiitis and idiopathic pulmonary hemosiderosis mitral stenosis can also lead to pulmonary hemosiderosis hemosiderin collects throughout the body in hemochromatosis hemosiderin deposition in the liver is a common feature of hemochromatosis and is the cause of liver failure in the disease selective iron deposition in the beta cells of pancreatic islets leads to diabetes due to distribution of transferrin receptor on the beta cells of islets and in the skin leads to hyperpigmentation hemosiderin deposition in the brain is seen after bleeds from any source including chronic subdural hemorrhage cerebral arteriovenous malformations cavernous hemangiomata hemosiderin collects in the skin and is slowly removed after bruising hemosiderin may remain in some conditions such as stasis dermatitis hemosiderin in the kidneys has been associated with marked hemolysis and a rare blood disorder called paroxysmal nocturnal hemoglobinuria hemosiderin may deposit in diseases associated with iron overload these diseases are typically diseases in which chronic blood loss requires frequent blood transfusions such as sickle cell anemia and thalassemia though beta thalassemia minor has been associated with hemosiderin deposits in the liver in those with non alcoholic fatty liver disease independent of any transfusions
hemosuccus pancreaticus also known as pseudohematobilia or wirsungorrhage is a rare cause of hemorrhage in the gastrointestinal tract it is caused by a bleeding source in the pancreas pancreatic duct or structures adjacent to the pancreas such as the splenic artery that bleed into the pancreatic duct which is connected with the bowel at the duodenum the first part of the small intestine patients with hemosuccus may develop symptoms of gastrointestinal hemorrhage such as blood in the stools maroon stools or melena which is a dark tarry stool caused by digestion of red blood cells they may also develop abdominal pain it is associated with pancreatitis pancreatic cancer and aneurysms of the splenic artery hemosuccus may be identified with endoscopy esophagogastroduodenoscopy where fresh blood may be seen from the pancreatic duct alternatively angiography may be used to inject the celiac axis to determine the blood vessel that is bleeding this may also be used to treat hemosuccus as embolization of the end vessel may terminate the hemorrhage however a distal pancreatectomy — surgery to removal of the tail of the pancreas — may be required to stop the hemorrhage
a hemothorax hemo thorax or haemothorax or haemorrhagic pleural effusion is a type of pleural effusion in which blood accumulates in the pleural cavity this excess fluid can interfere with normal breathing by limiting the expansion of the lungs
hennekam syndrome also known as hennekam lymphangiectasia – lymphedema syndrome and intestinal lymphagiectasia – lymphedema – mental retardation syndrome is an autosomal recessive disorder consisting of intestinal lymphangiectasia facial anomalies peripheral lymphedema and mild to moderate levels of growth and intellectual disability it is also known as lymphedema lymphangiectasia mental retardation syndrome in a subset of patients it is associated with ccbe 1 according research published by its namesake raoul hennekam other causal mutations were found in the fat 4 gene previously mutations in the fat 4 gene had been only associated with van maldergem syndrome the molecular etiology of the lymphedema phenotype in ccbe 1 associated cases was identified as a diminished ability of the mutated ccbe 1 to accelerate and focus the activation of the primary lymphangiogenic growth factor vegf c
henoch – schönlein purpura hsp also known as iga vasculitis anaphylactoid purpura purpura rheumatica and schönlein – henoch purpura is a disease of the skin mucous membranes and sometimes other organs that most commonly affects children in the skin the disease causes palpable purpura small hemorrhages often with joint pain and abdominal pain with kidney involvement there may be a loss of small amounts of blood and protein in the urine hematuria and proteinuria but this usually goes unnoticed in a small proportion of cases the kidney involvement proceeds to chronic kidney disease hsp is often preceded by an infection such as a throat infection hsp is a systemic vasculitis inflammation of blood vessels and is characterized by deposition of immune complexes containing the antibody immunoglobulin a iga the exact cause for this phenomenon is unknown it usually resolves within several weeks and requires no treatment apart from symptom control but may relapse in a third of cases and cause irreversible kidney damage in about one in a hundred cases
heparin induced thrombocytopenia hit is the development of thrombocytopenia a low platelet count due to the administration of various forms of heparin an anticoagulant hit predisposes to thrombosis the abnormal formation of blood clots inside a blood vessel and when thrombosis is identified the condition is called heparin induced thrombocytopenia and thrombosis hitt hit is caused by the formation of abnormal antibodies that activate platelets if someone receiving heparin develops new or worsening thrombosis or if the platelet count falls hit can be confirmed with specific blood tests the treatment of hit requires both protection from thrombosis and choice of an agent that will not reduce the platelet count further several alternatives are available for this purpose and mainly used are danaparoid fondaparinux argatroban and bivalirudin while heparin was discovered in the 1930 s hit was not reported until the 1960 s
heparin necrosis is a cutaneous condition and usually occurs between days 5 and 10 of heparin therapy
hepatic encephalopathy he is the occurrence of confusion altered level of consciousness and coma as a result of liver failure in the advanced stages it is called hepatic coma or coma hepaticum it may ultimately lead to death it is caused by accumulation in the bloodstream of toxic substances that are normally removed by the liver the diagnosis of hepatic encephalopathy requires the presence of impaired liver function and the exclusion of an alternative explanation for the symptoms blood tests ammonia levels may assist in the diagnosis attacks are often caused by another problem such as infection or constipation hepatic encephalopathy is reversible with treatment this relies on suppressing the production of the toxic substances in the intestine and is most commonly done with the laxative lactulose or with non absorbable antibiotics in addition the treatment of any underlying condition may improve the symptoms in particular settings such as acute liver failure the onset of encephalopathy may indicate the need for a liver transplant
hepatic microvascular dysplasia hmd or mvd or portal atresia is a disorder where mixing of venous blood and arterial blood in the liver occurs at the microscopic level it occurs most commonly in certain dog breeds such as the cairn and yorkshire terriers although any dog breed may be at risk
hepatic porphyrias is a form of porphyria in which the enzyme deficiency occurs in the liver examples include in order of synthesis pathway acute intermittent porphyria porphyria cutanea tarda and hepatoerythropoietic porphyria hereditary coproporphyria variegate porphyria
hepatic veno occlusive disease or veno occlusive disease vod is a condition in which some of the small veins in the liver are obstructed it is a complication of high dose chemotherapy given before a bone marrow transplant bmt and is marked by weight gain due to fluid retention increased liver size and raised levels of bilirubin in the blood the name sinusoidal obstruction syndrome is now preferred if vod happens as a result of chemotherapy or bone marrow transplantation apart from chemotherapy vod may also occur after ingestion of certain plant alkaloids such as pyrrolizidine alkaloids in some herbal teas and has been described as part of a rare hereditary disease called hepatic venoocclusive disease with immunodeficiency which results from mutations in the gene coding for a protein called sp 110
hepatitis is a disease of the liver characterized by the presence of inflammation hepatitis may occur without symptoms but can lead to jaundice a yellow discoloration of the skin mucous membranes and conjunctiva of the eyes poor appetite and fatigue depending on the cause hepatitis can manifest either as an acute or as a chronic disease acute hepatitis can be self limiting resolving on its own can progress to chronic hepatitis or can cause acute liver failure in rare instances chronic hepatitis may have no symptoms or may progress over time to cirrhosis scarring of the liver fibrosis the formation of extra fibrous connective tissue and chronic liver failure cirrhosis of the liver increases the risk of developing hepatocellular carcinoma a form of liver cancer worldwide viral hepatitis is the most common cause followed closely by alcoholic liver disease and non alcoholic liver disease nafld other less common causes of hepatitis include autoimmune diseases ingestion of toxic substances certain medications such as paracetamol some industrial organic solvents and plants the word is derived from the greek hêpar ἧπαρ meaning liver and the suffix itis ῖτις meaning inflammation c 1727
hepatitis a formerly known as infectious hepatitis is an acute infectious disease of the liver caused by the hepatitis a virus hav many cases have few or no symptoms especially in the young the time between infection and symptoms in those who develop them is between two and six weeks when symptoms occur they typically last eight weeks and may include nausea vomiting diarrhea jaundice fever and abdominal pain around 10 – 15 of people experience a recurrence of symptoms during the six months after the initial infection acute liver failure may rarely occur with this being more common in the elderly it is usually spread by eating or drinking food or water contaminated with infected feces shellfish which have not been sufficiently cooked are a relatively common source it may also be spread through close contact with an infectious person while children often do not have symptoms when infected they are still able to infect others after a single infection a person is immune for the rest of his or her life diagnosis requires blood testing as the symptoms are similar to those of a number of other diseases it is one of five known hepatitis viruses a b c d and e the hepatitis a vaccine is effective for prevention some countries recommend it routinely for children and those at higher risk who have not previously been vaccinated it appears to be effective for life other preventive measures include hand washing and properly cooking food no specific treatment is available with rest and medications for nausea or diarrhea recommended on an as needed basis infections usually resolve completely and without ongoing liver disease treatment of acute liver failure if it occurs is with liver transplantation globally around 1 4 million symptomatic cases occur each year and about 102 million infections symptomatic and asymptomatic it is more common in regions of the world with poor sanitation and not enough safe water in the developing world about 90 of children have been infected by age 10 and thus are immune by adulthood it often occurs in outbreaks in moderately developed countries where children are not exposed when young and vaccination is not widespread acute hepatitis a resulted in 102 000 deaths in 2010 world hepatitis day occurs each year on july 28 to bring awareness to viral hepatitis
hepatitis b is an infectious disease caused by the hepatitis b virus hbv which affects the liver it can cause both acute and chronic infections many people have no symptoms during the initial infection some develop a rapid onset of sickness with vomiting yellowish skin tiredness dark urine and abdominal pain often these symptoms last a few weeks and rarely does the initial infection result in death it may take 30 to 180 days for symptoms to begin in those who get infected around the time of birth 90 develop chronic hepatitis b while less than 10 of those infected after the age of five do most of those with chronic disease have no symptoms however cirrhosis and liver cancer may eventually develop these complications result in the death of 15 to 25 of those with chronic disease the virus is transmitted by exposure to infectious blood or body fluids infection around the time of birth or from contact with other people s blood during childhood is the most frequent method by which hepatitis b is acquired in areas where the disease is common in areas where the disease is rare intravenous drug use and sexual intercourse are the most frequent routes of infection other risk factors include working in healthcare blood transfusions dialysis living with an infected person travel in countries where the infection rate is high and living in an institution tattooing and acupuncture led to a significant number of cases in the 1980 s however this has become less common with improved sterility the hepatitis b viruses cannot be spread by holding hands sharing eating utensils kissing hugging coughing sneezing or breastfeeding the infection can be diagnosed 30 to 60 days after exposure diagnosis is typically by testing the blood for parts of the virus and for antibodies against the virus it is one of five known hepatitis viruses a b c d and e the infection has been preventable by vaccination since 1982 vaccination is recommended by the world health organization in the first day of life if possible two or three more doses are required at a later time for full effect this vaccine works about 95 of the time about 180 countries gave the vaccine as part of national programs as of 2006 it is also recommended that all blood be tested for hepatitis b before transfusion and condoms be used to prevent infection during an initial infection care is based on the symptoms that a person has in those who develop chronic disease antiviral medication such as tenofovir or interferon may be useful however these drugs are expensive liver transplantation is sometimes used for cirrhosis about a third of the world population has been infected at one point in their lives including 240 million to 350 million who have chronic infections another 129 million new infections occurred in 2013 over 750 000 people die of hepatitis b each year about 300 000 of these are due to liver cancer the disease is now only common in east asia and sub saharan africa where between 5 and 10 of adults are chronically infected rates in europe and north america are less than 1 it was originally known as serum hepatitis research is looking to create foods that contain hbv vaccine the disease may affect other great apes as well
hepatitis c is an infectious disease caused by the hepatitis c virus hcv that primarily affects the liver during the initial infection people often have mild or no symptoms occasionally a fever dark urine abdominal pain and yellow tinged skin occurs the virus persists in the liver in about 75 to 85 of those initially infected early on chronic infection typically has no symptoms over many years however it often leads to liver disease and occasionally cirrhosis in some cases those with cirrhosis will develop complications such as liver failure liver cancer or esophageal and gastric varices hcv is spread primarily by blood to blood contact associated with intravenous drug use poorly sterilized medical equipment needlestick injuries in healthcare and transfusions with blood screening the risk from a transfusion is less than one per two million it may also be spread from an infected mother to her baby during birth it is not spread by superficial contact it is one of five known hepatitis viruses a b c d and e diagnosis is by blood testing to look for either antibodies to the virus or its rna testing is recommended in all people who are at risk there is no vaccine against hepatitis c prevention includes harm reduction efforts among people who use intravenous drugs and testing donated blood chronic infection can be cured about 90 of the time with treatments that include the medications sofosbuvir or simeprevir previous to this a combination of peginterferon and ribavirin was used which had a cure rate around 50 and greater side effects getting access to the newer treatments however can be expensive those who develop cirrhosis or liver cancer may require a liver transplant hepatitis c is the leading reason for liver transplantation though the virus usually recurs after transplantation an estimated 130 – 200 million people worldwide are infected with hepatitis c in 2013 about 11 million new cases occurred it occurs most commonly in africa and central and east asia about 343 000 deaths due to liver cancer and 358 000 deaths due to cirrhosis occurred in 2013 due to hepatitis c the existence of hepatitis c – originally identifiable only as a type of non a non b hepatitis – was suggested in the 1970 s and proven in 1989 hepatitis c infects only humans and chimpanzees
hepatitis d hepatitis delta is a disease caused by the hepatitis d virus hdv a small spherical enveloped rna virus this is one of five known hepatitis viruses a b c d and e hdv is considered to be a subviral satellite because it can propagate only in the presence of the hepatitis b virus hbv transmission of hdv can occur either via simultaneous infection with hbv coinfection or superimposed on chronic hepatitis b or hepatitis b carrier state superinfection both superinfection and coinfection with hdv results in more severe complications compared to infection with hbv alone these complications include a greater likelihood of experiencing liver failure in acute infections and a rapid progression to liver cirrhosis with an increased risk of developing liver cancer in chronic infections in combination with hepatitis b virus hepatitis d has the highest fatality rate of all the hepatitis infections at 20
hepatitis e is a viral hepatitis liver inflammation caused by infection with a virus called hepatitis e virus it is one of five known human hepatitis viruses a b c d and e hev is a positive sense single stranded non enveloped rna icosahedral virus hev has a fecal oral transmission route infection with this virus was first documented in 1955 during an outbreak in new delhi india a preventative vaccine hev 239 is approved for use in china although hepatitis e often causes an acute and self limiting infection the virus usually resolves itself and the individual recovers with low mortality rates in the western world it bears a high risk of developing chronic hepatitis in immunocompromised patients with substantial mortality rates organ transplant recipients who receive immunosuppressive medication to prevent rejection are thought to be the main population at risk for chronic hepatitis e furthermore in healthy individuals during the duration of the infection the disease severely impairs a person ’ s ability to work care for family members and other daily activities hepatitis e occasionally develops into an acute severe liver disease and is fatal in about 2 of all cases clinically it is comparable to hepatitis a but in pregnant women the disease is more often severe and is associated with a clinical syndrome called fulminant liver failure pregnant women especially those in the third trimester suffer an elevated mortality rate from the disease of around 20 hepatitis e newly affected about 28 million people in 2013
hepatoblastoma is an uncommon malignant liver cancer occurring in infants and children and composed of tissue resembling fetal liver cells mature liver cells or bile duct cells they usually present with an abdominal mass the disease is most commonly diagnosed during a child s first three years of life alpha fetoprotein afp levels are commonly elevated but when afp is not elevated at diagnosis the prognosis is poor
hepatocellular adenoma also hepatic adenoma or rarely hepadenoma is an uncommon benign liver tumor which is associated with the use of hormonal contraception with a high estrogen content patients of advanced age or taking higher potency hormones or patients with prolonged duration of use have a significantly increased risk of developing hepatocellular adenomas
hepatocellular carcinoma hcc also called malignant hepatoma is the most common type of liver cancer most cases of hcc are as a result of either a viral hepatitis infection hepatitis b or c metabolic toxins such as alcohol or aflatoxin conditions like hemochromatosis and alpha 1 antitrypsin deficiency or nash treatment options for hcc and prognosis are dependent on many factors but especially on tumour size staging and extent of liver injury tumour grade is also important high grade tumors will have a poor prognosis while low grade tumors may go unnoticed for many years as is the case in many other organs hcc is relatively uncommon in the united states and many other developed countries it occurs most commonly in countries where hepatitis b infections are common
hepatocyte growth factor scatter factor hgf sf is a paracrine cellular growth motility and morphogenic factor it is secreted by mesenchymal cells and targets and acts primarily upon epithelial cells and endothelial cells but also acts on haemopoietic progenitor cells and t cells it has been shown to have a major role in embryonic organ development specifically in myogenesis in adult organ regeneration and in wound healing
hepatoerythropoietic porphyria is a very rare form of hepatic porphyria caused by a disorder in both genes which code uroporphyrinogen iii decarboxylase urod it has a similar presentation to porphyria cutanea tarda pct but with earlier onset in classifications which define pct type 1 as sporadic and pct type 2 as familial hepatoerythropoietic porphyria is more similar to type 2
hepatolithiasis is the presence of gallstones in the biliary ducts of the liver treatment is usually surgical it is rare in western countries but prevalent in east asia the gallstones are normally found proximal to the left and right hepatic ducts the causes of the disease are poorly understood but it is suspected that genetics diets and environmental causes may contribute it is more common in those of low socioeconomic status who suffer from malnutrition typically is strikes between 50 and 70 years old with neither men nor women more likely to acquire it the prevalence in east asia ranges is as high as 30 50 while in the west it is rare however immigration has increased its prevalence in the west countries that have seen more economic development have also seen a reduction in the rates of the disease some patients have these gallstones with no symptoms and the disease is only detected through abdominal imaging for those with symptoms common ones are abdominal pain jaundice and fever the gallstones can cause more serious conditions like fibrinolys disorder or gallstone pancreatitis
hepatomegaly is the condition of having an enlarged liver it is a non specific medical sign having many causes which can broadly be broken down into infection hepatic tumours or metabolic disorder often hepatomegaly will present as an abdominal mass depending on the cause it may sometimes present along with jaundice
hepatoprotection or antihepatotoxicity is the ability to prevent damage to the liver this damage is known as hepatotoxicity
in medicine hepatopulmonary syndrome is a syndrome of shortness of breath and hypoxemia low oxygen levels in the blood of the arteries caused by vasodilation broadening of the blood vessels in the lungs of patients with liver disease dyspnea and hypoxemia are worse in the upright position which is called platypnea and orthodeoxia respectively
hepatorenal syndrome often abbreviated hrs is a life threatening medical condition that consists of rapid deterioration in kidney function in individuals with cirrhosis or fulminant liver failure hrs is usually fatal unless a liver transplant is performed although various treatments such as dialysis can prevent advancement of the condition hrs can affect individuals with cirrhosis severe alcoholic hepatitis or liver failure and usually occurs when liver function deteriorates rapidly because of a sudden insult such as an infection bleeding in the gastrointestinal tract or overuse of diuretic medications hrs is a relatively common complication of cirrhosis occurring in 18 of people within one year of their diagnosis and in 39 within five years of their diagnosis deteriorating liver function is believed to cause changes in the circulation that supplies the intestines altering blood flow and blood vessel tone in the kidneys the kidney failure of hrs is a consequence of these changes in blood flow rather than direct damage to the kidney the diagnosis of hepatorenal syndrome is based on laboratory tests of individuals susceptible to the condition two forms of hepatorenal syndrome have been defined type 1 hrs entails a rapidly progressive decline in kidney function while type 2 hrs is associated with ascites fluid accumulation in the abdomen that does not improve with standard diuretic medications the risk of death in hepatorenal syndrome is very high the mortality of individuals with type 1 hrs is over 50 over the short term as determined by historical case series the only long term treatment option for the condition is liver transplantation while awaiting transplantation people with hrs often receive other treatments that improve the abnormalities in blood vessel tone including supportive care with medications or the insertion of a transjugular intrahepatic portosystemic shunt tips which is a small shunt placed to reduce blood pressure in the portal vein some patients may require hemodialysis to support kidney function or a newer technique called liver dialysis which uses a dialysis circuit with albumin bound membranes to bind and remove toxins normally cleared by the liver providing a means of extracorporeal liver support until transplantation can be performed
hepatosplenic t cell lymphoma is a rare and generally incurable form of lymphoma
hepatosplenomegaly commonly abbreviated hsm is the simultaneous enlargement of both the liver hepatomegaly and the spleen splenomegaly hepatosplenomegaly can occur as the result of acute viral hepatitis infectious mononucleosis and histoplasmosis or it can be the sign of a serious and life threatening lysosomal storage disease systemic venous hypertension can also increase the risk for developing hepatosplenomegaly which may be seen in those patients with right sided heart failure
hepatotoxicity from hepatic toxicity implies chemical driven liver damage drug induced liver injury is a cause of acute and chronic liver disease the liver plays a central role in transforming and clearing chemicals and is susceptible to the toxicity from these agents certain medicinal agents when taken in overdoses and sometimes even when introduced within therapeutic ranges may injure the organ other chemical agents such as those used in laboratories and industries natural chemicals e g microcystins and herbal remedies can also induce hepatotoxicity chemicals that cause liver injury are called hepatotoxins more than 900 drugs have been implicated in causing liver injury and it is the most common reason for a drug to be withdrawn from the market hepatotoxicity and drug induced liver injury also account for a substantial number of compound failures highlighting the need for drug screening assays such as stem cell derived hepatocyte like cells that are capable of detecting toxicity early in the drug development process chemicals often cause subclinical injury to the liver which manifests only as abnormal liver enzyme tests drug induced liver injury is responsible for 5 of all hospital admissions and 50 of all acute liver failures
hepatyrix is a combined hepatitis a and typhoid vaccination a combination of inactivated hepatitis a virus and vi polysaccharide of salmonella typhi bacteria manufactured by glaxosmithkline
herbal magic is a canadian weight loss and nutrition company based in toronto ontario operating through a network of approximately 150 weight loss and nutrition centres across canada herbal magic is canada s largest commercial weight loss company the program includes one on one personal coaching natural health products including vitamin support and grocery store bought food
a hereditary cns demyelinating disease is a demyelinating central nervous system disease that is primarily due to an inherited genetic condition this is in contrast to autoimmune demyelinating conditions such as multiple sclerosis or conditions such as central pontine myelinolysis that are associated with acute acquired insult examples include alexander disease canavan disease krabbe disease leukoencephalopathy with vanishing white matter megalencephalic leukoencephalopathy with subcortical cysts metachromatic leukodystrophy x linked adrenoleukodystrophy
hereditary angioedema hae is a rare autosomal dominantly inherited blood disorder that causes episodic attacks of swelling that may affect the face extremities genitals gastrointestinal tract and upper airways in this form of angioedema swellings of the intestinal mucous membrane may lead to vomiting and painful colic like intestinal spasms that may mimic intestinal obstruction airway edema may be life threatening episodes may be triggered by trauma surgery dental work menstruation some medications viral illness and stress however this is not always readily determined this disorder affects approximately one in 10 000 – 50 000 people the underlying cause of most hae is autosomal dominant inheritance of mutations in the c 1 inhibitor gene c 1 inh gene or serping 1 gene which is mapped to chromosome 11 11 q 12 q 13 1 to date there are over 300 known genetic mutations that result in a deficiency of functional c 1 inhibitor protein the majority of hae patients have a family history however 25 are the result of new mutations the low level of c 1 inhibitor in the plasma leads to increased activation of pathways that release bradykinin the chemical responsible for the angioedema due to increased vascular permeability and the pain seen in individuals with hae the most common form of the disorder is hae type i which is the result of abnormally low amounts low serum levels of c 1 inhibitors which are responsible for maintaining proper balance homeostasis in the complement system specifically keeping the c 1 part of the classical complement pathway from being overactive this inhibition helps to regulate various body functions e g flow of body fluids in and out of cells hae type ii is a more uncommon form of the disorder it occurs as the result of the production of c 1 inhibitor that is normal in amount but does not work well abnormal structure and function type ii accounts for about 15 20 of hae type iii is a very rare recently documented form it predominantly affects females and it is influenced by exposure to estrogens or hormone replacement therapy e g oral contraceptives and pregnancy and is not associated with c 1 inh deficiency hae type iii is not due to c 1 inh deficiency it is linked to an increase in kininogenase activity leading to elevated levels of bradykinin some patients with type iii hae have a mutation in the f 12 gene which produces a protein involved in blood clotting
hereditary benign intraepithelial dyskeratosis is a rare autosomal dominant disease of the conjunctiva and the oral mucosa caused by a duplication of chromosome 4 q 35 in the mouth it appears similar to white sponge nevus with painless diffuse folded and spongy white plaques in the eye it appears as gelatinous plaques on bulbar perilimbal conjunctiva
hereditary breast – ovarian cancer syndromes hboc are cancer syndromes that produce higher than normal levels of breast cancer and ovarian cancer in genetically related families either one individual had both or several individuals in the pedigree had one or the other disease the hereditary factors may be proven or suspected to cause the pattern of breast and ovarian cancer occurrences in the family
hereditary coproporphyria hcp is a disorder of heme biosynthesis classified as an acute hepatic porphyria hcp is caused by a deficiency of the enzyme coproporphyrinogen oxidase coded for by the cpox gene and is inherited in an autosomal dominant fashion although homozygous individuals have been identified unlike acute intermittent porphyria individuals with hcp can present with cutaneous findings similar to those found in porphyria cutanea tarda in addition to the acute attacks of abdominal pain vomiting and neurological dysfunction characteristic of acute porphyrias like other porphyrias attacks of hcp can be induced by certain drugs environmental stressors or diet changes biochemical and molecular testing can be used to narrow down the diagnosis of a porphyria and identify the specific genetic defect overall porphyrias are rare diseases the combined incidence for all forms of the disease has been estimated at 1 20 000 the exact incidence of hcp is difficult to determine due to its reduced penetrance
hereditary cystatin c amyloid angiopathy hccaa is a rare fatal amyloid disease in young people in iceland caused by a mutation in cystatin c most of the families with the defect gene can be traced to a region in the northwest of iceland around breiðafjörður mutations in the cystatin 3 gene are responsible for the icelandic type of hereditary cerebral amyloid angiopathy a condition predisposing to intracerebral haemorrhage stroke and dementia the condition is inherited in a dominant fashion
hereditary diffuse gastric cancer is an inherited genetic syndrome caused by a change in the e cadherin gene it often results in stomach cancer such that it is recommended that those who carry the gene have their stomach removed
hereditary diffuse leukoencephalopathy with spheroids hdls is a rare adult onset autosomal dominant disorder characterized by cerebral white matter degeneration with demyelination and axonal spheroids leading to progressive cognitive and motor dysfunction spheroids are axonal swellings with discontinuous or absence of myelin sheaths it is believed that the disease arises from primary microglial dysfunction that leads to secondary disruption of axonal integrity neuroaxonal damage and focal axonal spheroids leading to demyelination spheroids in hdls resemble to some extent those produced by shear stress in a closed head injury with damage to axons causing them to swell due to blockage of axoplasmic transport in addition to trauma axonal spheroids can be found in aged brain stroke and in other degenerative diseases in hdls it is uncertain whether demyelination occurs prior to the axonal spheroids or what triggers neurodegeneration after apparently normal brain and white matter development although genetic deficits suggest that demyelination and axonal pathology may be secondary to microglial dysfunction the clinical syndrome in patients with hdls is not specific and it can be mistaken for alzheimer s disease frontotemporal dementia atypical parkinsonism multiple sclerosis or corticobasal degeneration
hereditary elliptocytosis also known as ovalocytosis is an inherited blood disorder in which an abnormally large number of the patient s erythrocytes i e red blood cells are elliptical rather than the typical biconcave disc shape such morphologically distinctive erythrocytes are sometimes referred to as elliptocytes or ovalocytes it is one of many red cell membrane defects in its severe forms this disorder predisposes to haemolytic anaemia although pathological in humans elliptocytosis is normal in camelids
hereditary folate malabsorption hfm omim 229050 is a rare autosomal recessive disorder caused by caused by loss of function mutations in the proton coupled folate transporter pcft gene resulting in systemic folate deficiency and impaired delivery of folate to the brain
hereditary fructose intolerance hfi is an inborn error of fructose metabolism caused by a deficiency of the enzyme aldolase b individuals affected with hfi are asymptomatic until they ingest fructose sucrose or sorbitol if fructose is ingested the enzymatic block at aldolase b causes an accumulation of fructose 1 phosphate this accumulation has downstream effects on gluconeogenesis and regeneration of adenosine triphosphate atp symptoms of hfi include vomiting hypoglycemia jaundice hemorrhage hepatomegaly hyperuricemia and potentially kidney failure while hfi is not clinically a devastating condition there are reported deaths in infants and children as a result of the metabolic consequences of hfi death in hfi is always associated with problems in diagnosis hfi is an autosomal recessive condition caused by mutations in the aldob gene located at 9 q 22 3 hfi is typically suspected based on dietary history especially in infants who become symptomatic after breast feeding this suspicion is typically confirmed by molecular analysis treatment of hfi involves strict avoidance of fructose in the diet older patients with hfi typically self select a diet low in fructose even before being diagnosed
hereditary gelsolin amyloidosis is a cutaneous condition inherited in an autosomal dominant fashion the condition was first described in 1969 by the finnish ophthalmologist jouko meretoja and is also known as familial amyloid neuropathy type iv meretoja syndrome hereditary amyloidosis finnish type the disorder primarily associated with eye skin and cranial nerve symptoms it is a form of amyloidosis where the amyloid complexes are formed from fragments of the protein gelsolin in the plasma due to an mutation in the gsn gene c 654 g a or c 654 g t
hereditary gingival fibromatosis hgf also known as idiopathic gingival hyperplasia is a rare condition of gingival overgrowth hgf is characterized as a benign slowly progressive nonhemorrhagic fibrous enlargement of keratinized gingiva it can cover teeth in various degrees and can lead to aesthetic disfigurement fibrous enlargement is most common in areas of maxillary and mandibular tissues of both arches in the mouth phenotype and genotype frequency of hgf is 1 175 000 where males and females are equally affected but the cause is not entirely known it mainly exists as an isolated abnormality but can also be associated with a multi system syndrome
hereditary hemorrhagic telangiectasia hht also known as osler – weber – rendu disease and osler – weber – rendu syndrome is an autosomal dominant genetic disorder that leads to abnormal blood vessel formation in the skin mucous membranes and often in organs such as the lungs liver and brain it may lead to nosebleeds acute and chronic digestive tract bleeding and various problems due to the involvement of other organs treatment focuses on reducing bleeding from blood vessel lesions and sometimes surgery or other targeted interventions to remove arteriovenous malformations in organs chronic bleeding often requires iron supplements and sometimes blood transfusions hht is transmitted in an autosomal dominant fashion and occurs in one in 5 000 people the disease carries the names of sir william osler henri jules louis marie rendu and frederick parkes weber who described it in the late 19 th and early 20 th centuries
hereditary hyperbilirubinemia refers to the condition where levels of bilirubin are elevated for reasons that can be attributed to a metabolic disorder an example is crigler najjar syndrome
reed ’ s syndrome or familial leiomyomatosis cutis et uteri is a rare inherited condition characterised by multiple cutaneous leiomyomas and in women uterine leiomyomas it predisposes for renal cell cancer an association denominated hereditary leiomyomatosis and renal cell cancer and it is also associated with increased risk of uterine leiomyosarcoma the syndrome is caused by a mutation in the fumarate hydratase gene which leads to an accumulation of fumarate the inheritance pattern is autosomal dominant
hybrid oncocytoma chromophobe renal cell carcinoma is rare subtype of renal cell carcinoma
hereditary motor and sensory neuropathies hmsn is a name sometimes given to a group of different neuropathies which are all characterized by their impact upon both afferent and efferent neural communication hmsn are characterised by atypical neural development and degradation of neural tissue the two common forms of hmsn are either hypertrophic demyelinated nerves or complete atrophy of neural tissue hypertrophic condition causes neural stiffness and a demyelination of nerves in the peripheral nervous system and atrophy causes the breakdown of axons and neural cell bodies in these disorders a patient experiences progressive muscle atrophy and sensory neuropathy of the extremities the term hereditary motor and sensory neuropathy was used mostly historically to denote the more common forms charcot – marie – tooth disease cmt with the identification of a wide number of genetically and phenotypically distinct forms of cmt the term hmsn is now used less frequently
hereditary motor and sensory neuropathy with proximal dominance hmsn p is an autosomal dominant neurodegenerative disorder that is defined by extensive involuntary and spontaneous muscle contractions asthenia and atrophy with distal sensory involvement following the disease starts presenting typically in the 40 s and is succeeded by a slow and continuous onslaught muscle spasms and muscle contractions large in number are noted especially in the earliest stages the presentation of hmsn p is quite similar to amyotrophic lateral sclerosis and has common neuropathological findings sensory loss happens as the disease progresses but the amount of sensation lost varies from case to case there have been other symptoms of hmsn p reported such as urinary disturbances and a dry cough two large families in japan have been identified with the disease locus to chromosome 3 q from descendants of japan hmsn p was brought to brazil from there it is a pretty isolated disease through clinical studies researchers identified that tfg mutations on chromosome 3 q 13 2 causes hmsn p the presence of tfg ubiquitin and or tdp 43 immunopositive cytoplasmic inclusions in motor neurons and cytosolic aggregation composed of tdp 43 in cultured cells expressing mutant tfg indicate a novel pathway of motor neuron death
hereditary mucoepithelial dysplasia hmd or simply mucoepithelial dysplasia is a rare autosomal dominant multiepithelial disorder causing systemic maldevelopment of the epithelia and mucous membranes that line the surface of tissues and structures throughout the body particularly affecting systems affiliated with mucosa which includes the respiratory digestive urinary reproductive and immune systems the disorder is attributed to improper formation of desmosomes and gap junctions which prevents proper cornification of the epithelial layer of the skin
hereditary multiple exostoses hme or mhe also known as diaphyseal aclasis is a rare medical condition in which multiple bony spurs or lumps also known as exostoses or osteochondromas develop on the bones of a child hme is synonymous with multiple hereditary exostoses and multiple osteochondromatosis which is the preferred term used by the world health organization
hereditary neuralgic amyotrophy hna is a neuralgic disorder that is characterized by nerve damage and muscle atrophy preceded by severe pain it is caused by a mutation in the sept 9 gene 17 q 25 while not much is known about this disorder it has been characterized to be similar to parsonage turner syndrome in prognosis for a comprehensive overview of hereditary and idiopathic neuralgic amyotrophy and its consequences for patients please see the pdf file link at the bottom of this page
hereditary neuropathy with liability to pressure palsy hnpp is a peripheral neuropathy a disorder of the nerves hnpp is a nerve disorder that affects the peripheral nerves — pressure on the nerves can cause tingling sensations numbness pain weakness muscle atrophy and even paralyzation of affected area in normal individuals these symptoms disappear quickly but in sufferers of hnpp even a short period of pressure can cause the symptoms to occur palsies can last from minutes days to weeks or even months the symptoms may vary — some individuals report minor problems whilst others experience severe discomfort and disability in many cases the symptoms are mild enough to go unnoticed the time period between episodes is known to vary between individuals hnpp has not been found to alter the lifespan although in some cases a decline in quality of life is noticed some sufferers 10 15 report various pains growing in severity with progression of the disease the nerves most commonly affected are the peroneal nerve at the fibular head leg and feet the ulnar nerve at the elbow arm and the median nerve at the wrist palm thumbs and fingers but any peripheral nerve can be affected hnpp is part of the group of hereditary motor and sensory neuropathy hmsn disorders and is linked to charcot – marie – tooth disease cmt
lynch syndrome hnpcc or hereditary nonpolyposis colorectal cancer is an autosomal dominant genetic condition that has a high risk of colon cancer as well as other cancers including endometrial cancer second most common ovary stomach small intestine hepatobiliary tract upper urinary tract brain and skin the increased risk for these cancers is due to inherited mutations that impair dna mismatch repair it is a type of cancer syndrome
hereditary pancreatitis hp is an inflammation of the pancreas attributed to genetic causes it was first described in 1952 by comfort and steinberg but it was not until 1996 that whitcomb et al isolated the first responsible mutation in the trypsinogen gene prss 1 on the long arm of chromosome seven 7 q 35 the term hereditary pancreatitis is used when a genetic biomarker is identified and familial pancreatitis otherwise
hereditary persistence of fetal hemoglobin hpfh bre hereditary persistence of foetal haemoglobin is a benign condition in which significant fetal hemoglobin hemoglobin f production continues well into adulthood disregarding the normal shutoff point after which only adult type hemoglobin should be produced
hereditary progressive mucinous histiocytosis is a very rare benign non langerhans cell histiocytosis an autosomal dominant or x linked hereditary disease described on the skin it has been found almost exclusively in women one case of the disease in a male patient has been reported
hereditary pyropoikilocytosis hpp is an autosomal recessive form of hemolytic anemia characterized by an abnormal sensitivity of red blood cells to heat and erythrocyte morphology similar to that seen in thermal burns patients with hpp tend to experience severe haemolysis and anaemia in infancy that gradually improves evolving toward typical elliptocytosis later in life however the hemolysis can lead to rapid sequestration and destruction of red cells splenectomy is curative when this occurs hpp has been associated with a defect of the erythrocyte membrane protein spectrin and with spectrin deficiency it was characterized in 1975 it is considered a severe form of hereditary elliptocytosis
hereditary sclerosing poikiloderma is an autosomal dominant conditions with skin changes consisting of generalized poikiloderma appearing in childhood
hereditary sensory and autonomic neuropathy hsan or hereditary sensory neuropathy hsn is a condition used to describe any of the types of this disease which inhibit sensation they are less common than charcot marie tooth disease
hereditary sensory and autonomic neuropathy type i hsan i or hereditary sensory neuropathy type i hsn i is a group of autosomal dominant inherited neurological diseases that affect the peripheral nervous system particularly on the sensory and autonomic functions the hallmark of the disease is the marked loss of pain and temperature sensation in the distal parts of the lower limbs the autonomic disturbances if present manifest as sweating abnormalities the beginning of the disease varies between adolescence and adulthood since affected individuals cannot feel pain minor wounds or blisters in the painless area may not be immediately recognized and can develop into extensive and deep foot ulcerations once infection occurs the complications such as inflammation and progressive destruction of the underlying bones may follow and may require amputation of the surrounding area hsan i is the most common type among the five types of hsan as a heterogeneous group of diseases hsan i can be divided into five subtypes hsan ia e most of the genes associated with the diseases have been identified however the molecular pathways leading to the manifestation of the diseases are not fully understood therefore the potential targets for therapeutic interventions are not known moreover gene based therapies for patients with the diseases are not available to date hence supportive care is the only treatment available for the patients
hereditary spastic paraplegia hsp also known as hereditary spastic paraparesis familial spastic paraplegias french settlement disease or strumpell lorrain disease is a group of inherited diseases whose main feature is progressive stiffness and contraction spasticity in the lower limbs as a result of damage to or dysfunction of the nerves hsp is not a form of cerebral palsy even though it physically may appear and behave much the same as for example spastic diplegia the origins of hsp are entirely separate phenomena from cerebral palsy despite this some of the same anti spasticity medications used in spastic cerebral palsy are sometimes used to try to treat hsp symptomatology the condition sometimes also affects the optic nerve and retina of the eye causes cataracts ataxia lack of muscle coordination epilepsy cognitive impairment peripheral neuropathy and deafness hsp is caused by defects in the mechanisms that transport proteins and other substances through the cell long nerves are affected because they have to transport cellular material through long distances and are particularly sensitive to defects of cellular transport hereditary spastic paraplegia was first described in 1883 by adolph strümpell a german neurologist and was later described more extensively in 1888 by maurice lorrain a french physician
hereditary spherocytosis also known as minkowski – chauffard syndrome is an autosomal dominant abnormality of erythrocytes the disorder is caused by mutations in genes relating to membrane proteins that allow for the erythrocytes to change shape the abnormal erythrocytes are sphere shaped spherocytosis rather than the normal biconcave disk shaped dysfunctional membrane proteins interfere with the cell s ability to be flexible to travel from the arteries to the smaller capillaries this difference in shape also makes the red blood cells more prone to rupture cells with these dysfunctional proteins are taken for degradation at the spleen this shortage of erythrocytes results in hemolytic anemia it was first described in 1871 and is the most common cause of inherited hemolysis in europe and north america within the caucasian population with an incidence of 1 in 5000 births the clinical severity of hs varies from symptom freecarrier to severe haemolysis because the disorder exhibits incomplete penetrance in its expression symptoms include anemia jaundice splenomegaly and fatigue on a blood smear howell jolly bodies may be seen within red blood cells primary treatment for patients with symptomatic hs has been total splenectomy which eliminates the hemolytic process allowing normal hemoglobin reticulocyte and bilirubin levels
hereditary stomatocytosis describes a number of inherited autosomal dominant human conditions which affect the red blood cell in which the membrane or outer coating of the cell leaks sodium and potassium ions
heredofamilial amyloidosis is an inherited condition that may be characterized by systemic or localized deposition of amyloid in body tissues
hermansky – pudlak syndrome hps is an extremely rare autosomal recessive disorder which results in oculocutaneous albinism decreased pigmentation bleeding problems due to a platelet abnormality platelet storage pool defect and storage of an abnormal fat protein compound lysosomal accumulation of ceroid lipofuscin it is considered to affect around 1 in 500 000 people worldwide with a significantly higher occurrence in puerto ricans with a prevalence of 1 in 1800 many of the clinical research studies on the disease have been conducted in puerto rico there are eight classic forms of the disorder based on the genetic mutation from which the disorder stems a ninth type has also been described this last type is due to a mutation in the gene pallidin pldn
hermite s problem is an open problem in mathematics posed by charles hermite in 1848 he asked for a way of expressing real numbers as sequences of natural numbers such that the sequence is eventually periodic precisely when the original number is a cubic irrational
a hernia is the exit of an organ such as the bowel through the wall of the cavity in which it normally resides hernias come in a number of different types most commonly they involve the abdomen specifically the groin groin hernias are most common of the inguinal type but may also be femoral other hernias include hiatus incisional and umbilical hernias for groin hernias symptoms are present in about 66 of people this may include pain or discomfort especially with coughing exercise or going to the toilet often it gets worse throughout the day and improves when lying down a bulging area may occur that becomes larger when bearing down groin hernias occur more often on the right than left side the main concern is strangulation where the blood supply to part of the bowel is blocked this usually produces severe pain and tenderness of the area hiatus or hiatal hernias often result in heartburn but may also cause chest pain or pain with eating risk factors for the development of a hernia include smoking chronic obstructive pulmonary disease obesity pregnancy peritoneal dialysis collagen vascular disease and previous open appendectomy among others hernias are partly genetic and occur more often in certain families it is unclear if groin hernias are associated with heavy lifting hernias can often be diagnosed based on signs and symptoms occasionally medical imaging is used to confirm the diagnosis or rule out other possible causes the diagnosis of hiatus hernias is often by endoscopy groin hernias that do not cause symptoms in males do not need to be repaired repair however is generally recommended in women due to the higher rate of femoral hernias which have more complications if strangulation occurs immediate surgery is required repair may be done by open surgery or by laparoscopic surgery open surgery has the benefit of possibly being done under local anesthesia rather than general anesthesia laparoscopic surgery generally has less pain following the procedure a hiatus hernia may be treated with lifestyle changes such as raising the head of the bed weight loss and adjusting eating habits the medications h 2 blockers or proton pump inhibitors may help if the symptoms do not improve with medications the surgery known as laparoscopic fundoplication may be an option about 27 of males and 3 of females develop a groin hernia at some time in their life groin hernias occur most often before the age of one and after the age of fifty inguinal femoral and abdominal hernias resulted in 32 500 deaths in 2013 and 50 500 in 1990 it is not known how commonly hiatus hernias occur with estimates in north america varying from 10 to 80 the first known description of a hernia dates back to at least 1550 bc in the ebers papyrus from egypt
the hero syndrome is a phenomenon affecting people who seek heroism or recognition usually by creating a desperate situation which they can resolve this can include unlawful acts such as arson the phenomenon has been noted to affect civil servants such as firefighters nurses police officers and security guards acts linked with the hero syndrome should not be confused with acts of malice for example a punished firefighter exacting revenge or an insatiable level of excitement as was found in a federal study of more than 75 firefighter arsonists however acts of the hero syndrome have been linked to previously failed heroism the hero syndrome may also be a more general yearning for self worth people with hero syndrome will usually cause an accident and pretend to help
herpangina also called mouth blisters is the name of a painful mouth infection caused by coxsackieviruses usually herpangina is produced by one particular strain of coxsackie virus a and the term herpangina virus refers to coxsackievirus a but it can also be caused by coxsackievirus b or echoviruses most cases of herpangina occur in the summer affecting mostly children however it occasionally occurs in adolescents and adults it was first characterized in 1920
herpes esophagitis is a viral infection of the esophagus caused by herpes simplex virus hsv while the disease most often occurs in immunocompromised patients including post chemotherapy immunosuppression with organ transplants and in aids herpes esophagitis can also occur in immunocompetent individuals
herpes labialis also called cold sores among other names is a type of herpes simplex occurring on the lip i e an infection caused by herpes simplex virus hsv an outbreak typically causes small blisters or sores on or around the mouth the sores typically heal within 2 – 3 weeks but the herpes virus remains dormant in the facial nerve branches following orofacial infection periodically reactivating in symptomatic people to create sores in the same area of the mouth or face at the site of the original infection cold sore has a frequency that varies from rare episodes to 12 or more recurrences per year people with the condition typically experience one to three attacks each year the frequency and severity of outbreaks generally decreases over time
herpes simplex greek ἕρπης herpēs creeping or latent is a viral disease caused by the herpes simplex virus infections are categorized based on the part of the body infected oral herpes involves the face or mouth it may result in small blisters in groups often called cold sores or fever blisters or may just cause a sore throat genital herpes often simply known as herpes may have minimal symptoms or form blisters that break open and result in small ulcers these typically heal over two to four weeks tingling or shooting pains may occur before the blisters appear herpes cycles between periods of active disease followed by periods without symptoms the first episode is often more severe and may be associated with fever muscle pains swollen lymph nodes and headaches over time episodes of active disease decrease in frequency and severity other disorders caused by herpes simplex include herpetic whitlow when it involves the fingers herpes of the eye herpes infection of the brain and neonatal herpes when it affects a newborn among others there are two types of herpes simplex virus type 1 hsv 1 and type 2 hsv 2 hsv 1 more commonly causes oral infections while hsv 2 more commonly causes genital infections they are transmitted by direct contact with body fluids or lesions of an infected individual transmission may still occur when symptoms are not present genital herpes is classified as a sexually transmitted infection it may be spread to an infant during childbirth after infection the viruses are transported along sensory nerves to the nerve cell bodies where they reside lifelong causes of recurrence may include decreased immune function stress and sunlight exposure oral and genital herpes is usually diagnosed based on the presenting symptoms the diagnosis may be confirmed by viral culture or detecting herpes dna in fluid from blisters testing the blood for antibodies against the virus can confirm a previous infection but will be negative in new infections the most effective method of avoiding genital infections is by avoiding vaginal oral and anal sex condom use decreases the risk somewhat daily antiviral medication taken by someone who has the infection can also reduce spread there is no available vaccine and once infected there is no cure paracetamol acetaminophen and topical lidocaine may be used to help with the symptoms treatments with antiviral medication such as aciclovir or valaciclovir can lessen the severity of symptomatic episodes worldwide rates of either hsv 1 or hsv 2 are between 60 and 95 in adults hsv 1 is usually acquired during childhood rates of both increase as people age rates of hsv 1 are between 70 and 80 in populations of low socioeconomic status and 40 to 60 in populations of improved socioeconomic status an estimated 536 million people worldwide 16 of the population were infected with hsv 2 as of 2003 with greater rates among women and those in the developing world most people with hsv 2 do not realize that they are infected
herpetic simplex keratitis also known as herpetic keratoconjunctivitis and herpesviral keratitis is a form of keratitis caused by recurrent herpes simplex virus hsv infection in the cornea it begins with infection of epithelial cells on the surface of the eye and retrograde infection of nerves serving the cornea primary infection typically presents as swelling of the conjunctiva and eyelids blepharoconjunctivitis accompanied by small white itchy lesions on the corneal surface the effect of the lesions varies from minor damage to the epithelium superficial punctate keratitis to more serious consequences such as the formation of dendritic ulcers infection is unilateral affecting one eye at a time additional symptoms include dull pain deep inside the eye mild to acute dryness and sinusitis most primary infections resolve spontaneously in a few weeks healing can be aided by the use of oral and topical antivirals subsequent recurrences may be more severe with infected epithelial cells showing larger dendritic ulceration and lesions forming white plaques the epithelial layer is sloughed off as the dendritic ulcer grows and mild inflammation iritis may occur in the underlying stroma of iris sensation loss occurs in lesional areas producing generalised corneal anaesthesia with repeated recurrences recurrence can be accompanied by chronic dry eye low grade intermittent conjunctivitis or chronic unexplained sinusitis following persistent infection the concentration of viral dna reaches a critical limit antibody responses against the viral antigen expression in the stroma can trigger a massive autoimmune response in the eye the response may result in the destruction of the corneal stroma resulting in loss of vision due to opacification of the cornea this is known as immune mediated stromal keratitis hsv infection is very common in humans it has been estimated that one third of the world population have recurrent infection keratitis caused by hsv is the most common cause of cornea derived blindness in developed nations therefore hsv infections are a large and worldwide public health problem the global incidence rate of new disease of herpes keratitis is roughly 1 5 million including 40 000 new cases of severe monocular visual impairment or blindness each year
herpes zoster ophthalmicus hzo and also known as ophthalmic zoster is a disease characterised by reactivation of dormant varicella zoster virus residing within the ophthalmic nerve the first division of the trigeminal nerve this condition is an important subtype of shingles representing 15 of all cases herpes zoster ophthalmicus is transmitted via direct contact or droplets varicella zoster virus is a dna virus which produces acidophilic intranuclear inclusion bodies the virus is neurotrophic in nature the frontal nerve is more commonly affected than the nasociliary nerve or lacrimal nerve
herpesviral encephalitis is encephalitis due to herpes simplex virus herpes simplex encephalitis hse is a viral infection of the human central nervous system it is estimated to affect at least 1 in 500 000 individuals per year and some studies suggest an incidence rate of 5 9 cases per 100 000 live births the majority of cases of herpes encephalitis are caused by herpes simplex virus 1 hsv 1 the same virus that causes cold sores 57 of american adults are infected with hsv 1 which is spread through droplets casual contact and sometimes sexual contact though most infected people never have cold sores about 10 of cases of herpes encephalitis are due to hsv 2 which is typically spread through sexual contact about 1 in 3 cases of hse result from primary hsv 1 infection predominantly occurring in individuals under the age of 18 2 in 3 cases occur in seropositive persons few of whom have history of recurrent orofacial herpes approximately 50 of individuals that develop hse are over 50 years of age
herpesviral meningitis is meningitis associated with herpes simplex virus hsv hsv 2 is the most common cause of mollaret s meningitis a type of recurrent viral meningitis this condition was first described in 1944 by french neurologist pierre mollaret recurrences usually last a few days or a few weeks and resolve without treatment they may recur weekly or monthly for approximately 5 years following primary infection
gingivostomatitis also known as primary herpetic gingivostomatitis or orolabial herpes is a combination of gingivitis and stomatitis or an inflammation of the oral mucosa and gingiva herpetic gingivostomatitis is often the initial presentation during the first primary herpes simplex infection it is of greater severity than herpes labialis cold sores which is often the subsequent presentations primary herpetic gingivostomatitis is the most common viral infection of the mouth primary herpetic gingivostomatitis phgs represents the clinically apparent pattern of primary herpes simplex virus hsv infection since the vast majority of other primary infections are symptomless phgs is caused predominantly by hsv 1 and affects mainly children prodromal symptoms such as fever anorexia irritability malaise and headache may occur in advance of disease the disease presents as numerous pin head vesicles which rupture rapidly to form painful irregular ulcerations covered by yellow – grey membranes sub mandibular lymphadenitis halitosis and refusal to drink are usual concomitant findings
a herpetic whitlow is a lesion whitlow on a finger or thumb caused by the herpes simplex virus it is a painful infection that typically affects the fingers or thumbs occasionally infection occurs on the toes or on the nail cuticle herpes whitlow can be caused by infection by hsv 1 or hsv 2 hsv 1 whitlow is often contracted by health care workers that come in contact with the virus it is most commonly contracted by dental workers and medical workers exposed to oral secretions it is also often observed in thumb sucking children with primary hsv 1 oral infection autoinoculation prior to seroconversion and in adults aged 20 to 30 following contact with hsv 2 infected genitals symptoms of herpetic whitlow include swelling reddening and tenderness of the skin of infected finger this may be accompanied by fever and swollen lymph nodes small clear vesicles initially form individually then merge and become cloudy associated pain often seems large relative to the physical symptoms the herpes whitlow lesion usually heals in two to three weeks it may reside in axillary sensory ganglia to cause recurrent herpetic lesions on that arm or digits
in anatomy heterochromia ancient greek ἕτερος héteros different χρώμα chróma color is a difference in coloration usually of the iris but also of hair or skin heterochromia is a result of the relative excess or lack of melanin a pigment it may be inherited or caused by genetic mosaicism chimerism disease or injury heterochromia of the eye heterochromia iridis or heterochromia iridum is of three kinds in complete heterochromia one iris is a different color from the other in sectoral heterochromia part of one iris is a different color from its remainder and finally in central heterochromia there are spikes of different colours radiating from the pupil though multiple causes have been posited the scientific consensus is that a lack of genetic diversity is the primary reason behind heterochromia this is due to a mutation of the genes that determine melanin distribution at the 8 htp pathway which usually only become corrupted due to chromosomal homogeneity eye color specifically the color of the irises is determined primarily by the concentration and distribution of melanin the affected eye may be hyperpigmented hyperchromic or hypopigmented hypochromic in humans usually an excess of melanin indicates hyperplasia of the iris tissues whereas a lack of melanin indicates hypoplasia
heterogeneous water oxidation water oxidation is one of the half reactions of water splitting 2 h 2 o → o 2 4 h 4 e − oxidation generation of dioxygen 4 h 4 e − → 2 h 2 reduction generation of dihydrogen 2 h 2 o → 2 h 2 o 2 total reaction of the two half reactions the oxidation step is the most demanding because it requires the coupling of 4 electron and proton transfers and the formation of an oxygen oxygen bond this process occurs naturally in plants photosystem ii to provide protons and electrons for the photosynthesis process and release oxygen to the atmosphere since hydrogen can be used as an alternative clean burning fuel there has been a need to split water efficiently however there are known materials that can mediate the reduction step efficiently therefore much of the current research is aimed at the oxidation half reaction also known as the oxygen evolution reaction oer current research focuses on understanding the mechanism of oer and development of new materials that catalyze the process
heterophoria is an eye condition in which the directions that the eyes are pointing at rest position when not performing binocular fusion are not the same as each other or not straight there can be esophoria where the eyes tend to cross inward in the absence of fusion exophoria in which they diverge or hyperphoria in which one eye points up or down relative to the other phorias are known as latent squint because the tendency of the eyes to deviate is kept latent by fusion a person with two normal eyes has single vision usually because of the combined use of the sensory and motor systems the motor system acts to point both eyes at the target of interest any offset is detected visually and the motor system corrects it heterophoria only occurs during dissociation of the left eye and right eye when fusion of the eyes is absent if you cover one eye e g with your hand you remove the sensory information about the eye s position in the orbit without this there is no stimulus to binocular fusion and the eye will move to a position of rest the difference between this position and where it would be were the eye uncovered is the heterophoria the opposite of heterophoria where the eyes are straight when relaxed and not fusing does not have an accepted term but might be called homeophoria or simply normal in contrast fixation disparity is a very small deviation of the pointing directions of the eyes that is present while performing binocular fusion heterophoria is usually asymptomatic this is when it is said to be compensated when fusional reserve is used to compensate for heterophoria it is known as compensating vergence in severe cases when the heterophoria is not overcome by fusional vergence sign and symptoms appear this is called decompensated heterophoria heterophoria may lead to squint or also known as strabismus
heteroplasmy is the presence of more than one type of organellar genome mitochondrial dna or plastid dna within a cell or individual it is an important factor in considering the severity of mitochondrial diseases because most eukaryotic cells contain many hundreds of mitochondria with hundreds of copies of mitochondrial dna it is common for mutations to affect only some mitochondria leaving most unaffected although detrimental scenarios are well studied heteroplasmy can also be beneficial for example centenarians show a higher than average degree of heteroplasmy microheteroplasmy is present in most individuals this refers to hundreds of independent mutations in one organism with each mutation found in about 1 – 2 of all mitochondrial genomes
heterotopic ossification ho is the process by which bone tissue forms outside of the skeleton
a heterotopic pregnancy is a rare complication of pregnancy in which both extra uterine ectopic pregnancy and intrauterine pregnancy occur simultaneously it may also be referred to as a combined ectopic pregnancy multiple ‑ sited pregnancy or coincident pregnancy
in organic chemistry the hexadehydro diels alder hdda reaction is an organic chemical reaction between a diyne 2 alkyne functional groups arranged in a conjugated system and an alkyne to form a reactive benzyne species via a 4 2 cycloaddition reaction this benzyne intermediate then reacts with a suitable trapping agent to form a substituted aromatic product this reaction is a derivative of the established diels alder reaction and proceeds via a similar 4 2 cycloaddition mechanism the hdda reaction is particularly effective for forming heavily functionalized aromatic systems and multiple ring systems in one synthetic step hdda figure generalized 2
hexokinase deficiency is an anemia causing condition associated with inadequate hexokinase specifically the hk 1 isozyme is involved
heyde s syndrome is a syndrome of gastrointestinal bleeding from angiodysplasia in the presence of aortic stenosis it is named after edward c heyde md who first noted the association in 1958 it is caused by the induction of von willebrand disease type iia vwd 2 a by a depletion of von willebrand factor vwf in blood flowing through the narrowed valvular stenosis
a hiatus of a television series is a break of at least several weeks in the normal schedule of broadcast programming it can occur during a season of a television program which is called a mid season break or can be between television seasons usually starting in june and ending in september on the northern hemisphere when shooting starts for the next season
a hiatus hernia or hiatal hernia is the protrusion or herniation of the upper part of the stomach into the chest cavity through the esophageal hiatus because of a tear or weakness in the diaphragm the most common cause is obesity the diagnosis is often by endoscopy or medical imaging a hiatus hernia may be treated with lifestyle changes such as raising the head of the bed weight loss and adjusting eating habits medications such as h 2 blockers or proton pump inhibitors may help if the symptoms do not improve with medications the surgery known as laparoscopic fundoplication may be an option
a hibernoma is a benign neoplasm of vestigial brown fat the term was originally used by gery in 1914
a hickey is a bruise or bruise like mark caused by the kissing or sucking of the skin usually on the neck or arm while biting might be part of giving a hickey sucking is sufficient to burst small superficial blood vessels under the skin hickeys typically last from 5 to 12 days and may be treated in the same way as other bruises ways to reduce the appearance of hickeys include icing recent hickeys to reduce swelling rubbing them with a chilled spoon to remove the bruise and applying a warm compress to older hickeys to dilate vessels and promote blood flow they can be covered with a concealer or powder corresponding to the sufferer s skin tone or a fake tan alternatively articles of clothing such as scarves snoods turtle necks or sleeves may be used to conceal hickeys
a hidden curriculum is a side effect of an education lessons which are learned but not openly intended such as the transmission of norms values and beliefs conveyed in the classroom and the social environment any learning experience may teach unintended lessons hidden curriculum often refers to knowledge gained in primary and secondary school settings usually with a negative connotation where the school strives for equal intellectual development as a positive aim in this sense a hidden curriculum reinforces existing social inequalities by educating students according to their class and social status the unequal distribution of cultural capital in a society mirrors a corresponding distribution of knowledge among its students
a hide or skin is an animal skin treated for human use common commercial hides include leather from cattle and other livestock animals buckskin alligator skin and snake skin all are used for shoes clothes and other fashion accessories leather is also used in upholstery interior decorating horse tack and harnesses such skins are sometimes still gathered from hunting and processed at a domestic or artisanal level but most leather making is now industrialized and large scale various tannins are used for this purpose the term hide is sometimes expanded to include furs which are harvested from various species including cats mustelids and bears
hidradenitis is any disease in which the histologic abnormality is primarily an inflammatory infiltrate around the eccrine glands this group includes neutrophilic eccrine hidradenitis and recurrent palmoplantar hidradenitis it can also be defined more generally as an inflammation of sweat glands hidradenitis suppurativa is a chronic cutaneous condition originally thought to be primarily characterized by suppurative inflammation of the apocrine sweat glands however recent evidence supports that the primary event is follicular hyperkeratosis and obstruction
hidradenitis suppurativa hs also known as acne inversa is a chronic skin disease characterized by clusters of abscesses or subcutaneous boil like infections oftentimes free of actual bacteria that most commonly affects the underarms under the breasts inner thighs groin and buttocks outbreaks are painful and may persist for years with interspersed periods of inflammation often culminating in sudden drainage of pus this process often forms open wounds that will not heal and frequently leads to significant scarring persistent lesions may lead to the formation of sinus tracts or tunnels connecting the abscesses or infections under the skin at this stage complete healing is usually not possible and progression is variable with some experiencing remission for months to years at a time while others may worsen and require multiple surgeries bacterial infections and cellulitis deep tissue inflammation are other common complications of hs depression and pain are often seen with hs and can be difficult to manage hs often goes undiagnosed for years due to embarrassment causing delay in seeking treatment hs flares may be triggered by emotional erotic stress sweating hormonal changes heat and humidity and the condition is exacerbated by friction from clothing the disease is not contagious there are indications that it is hereditary among certain ethnic groups and autoimmune in nature onset is most common in the late teens and early 20 s for unknown reasons people with hs develop plugging of their apocrine glands there is currently no known cure nor any consistently effective treatment incision and drainage procedures may provide symptomatic relief carbon dioxide laser surgery may be an effective treatment with a low chance of recurrence lukewarm sitz baths can provide relief gentle antiseptic skin cleansers and hydrogen peroxide assist in keeping affected areas free of bacteria the number of people affected is not well established but has been estimated as being between 1 24 4 1 and 1 600 0 2
hidradenocarcinoma also known as malignant hidradenoma malignant acrospiroma clear cell eccrine carcinoma or primary mucoepidermoid cutaneous carcinoma is a malignant adnexal tumor of the sweat gland it is the malignant variant of the benign hidradenoma it may develop de novo or in association with an existent hidradenoma this type of tumor typically develops in older individuals after age 40
hidradenoma also known as acrospiroma from akral peripheral spiroma epithelial tumor of sweat gland refers to a benign adnexal tumor of the apical sweat gland another name for hidradenoma is cystadenoma and hydrocystadenomas these are 1 – 3 cm translucent blue cystic nodules it usually presents as a single small skin colored lesion and is considered distinct from the closely related poroma hidradenomas are often sub classified based on subtle histologic differences for example clear cell hidradenoma or acrospiroma nodular hidradenoma or acrospiroma solid cystic hidradenoma discussion of sweat gland tumors can be difficult and confusing due to the complex classification and redundant terminology used to describe the same tumors for example acrospiroma and hidradenoma are synonymous and sometimes the term acrospiroma is used to generally describe benign sweat gland tumors in addition a single lesion may contain a mixture of cell types there has also been a change in understanding about how tumors that were previously believed to strictly derive from specific sweat gland types may in fact derive from both eccrine or apocrine glands hidradenomas are by definition benign with malignant transformation very rare when tumors show malignant characteristics they are known as hidradenocarcinoma surgical excision is usually curative and local recurrences are rare although malignant tumors may metastasize
hidrocystoma also known as cystadenoma a moll s gland cyst and a sudoriferous cyst is an adenoma of the sweat glands hidrocystomas are cysts of sweat ducts usually on the eyelids they are not tumours a similar sounding lesion called hidroadenoma is a benign tumour there are three types of sweat glands true sweat glands or eccrine glands sebaceous glands which have an oily secretion around hair follicles and apocrine glands which have more oily product than eccrine glands and are found on the face armpit and groin hidrocystomas usually arise from apocrine glands they are also called cysts of moll or sudoriferous cysts there may be a type of hidroadenoma that arises from eccrine glands but these are uncommon other related conditions on the eyelids include chalazion a granulomatous reaction to sebaceous glands on the eyelid lacrimal duct cysts cysts related to tear ducts and nasolacrimal duct cysts the nasolacrimal duct drains tears into the nose via a punctum on the lower eyelid
hierarchical model – view – controller hmvc is a software architectural pattern a variation of model – view – controller mvc similar to presentation – abstraction – control pac that was published in 2000 in an article in javaworld magazine the authors apparently unaware of pac which was published 13 years earlier the controller has some oversight the controller selects the model and then selects the view so there is an approval mechanism by the controller the model prevents the view from accessing the data source directly
high altitude cerebral edema hace is a medical condition in which the brain swells with fluid because of the physiological effects of traveling to a high altitude it generally appears in patients who have acute mountain sickness and involves disorientation lethargy and nausea among other symptoms it occurs when the body fails to acclimatize while ascending to a high altitude it appears to be a vasogenic edema fluid penetration of the blood – brain barrier although cytotoxic edema cellular retention of fluids may play a role as well individuals with the condition must immediately descend to a lower altitude or coma and death can occur patients are usually given supplemental oxygen and dexamethasone as well hace can be prevented by ascending to heights slowly to allow the body more time to acclimatize acetazolamide also helps prevent the condition untreated patients usually die within 48 hours those who receive treatment may take weeks to fully recover it is a rare condition occurring in less than one percent of people who ascend to 4 000 metres 13 000 ft first described in 1913 little was known about the etiology of the condition until mri studies were performed in the 1990 s
high altitude flatus expulsion hafe is a gastrointestinal syndrome which involves the spontaneous passage of increased quantities of rectal gases at high altitudes first described by joseph hamel in c 1820 and occasionally described afterward a landmark study of this phenomenon was published in 1981 by paul auerbach and york miller the phenomenon is based on the differential in atmospheric pressure directly correlated with the observer s frequency of and level of experience in high altitude metabolism as the external pressure decreases the difference in pressure between the gas within the body and the atmosphere outside is higher and the urge to expel gas to relieve the pressure is greater consistent with boyle s law controlling for dietary variance the amount of gas produced is constant in mass but the volume increases as the external pressure decreases the feeling of fullness or need to expel brought on by this differential in atmospheric pressure has been verified by studies involving military pilots subjected to pressure changes simulating flight
high altitude pulmonary edema hape hapo spelled oedema in british english is a life threatening form of non cardiogenic pulmonary edema fluid accumulation in the lungs that occurs in otherwise healthy mountaineers at altitudes typically above 2 500 meters 8 200 ft however cases have also been reported at lower altitudes between 1 500 – 2 500 metres or 4 900 – 8 200 feet in highly vulnerable subjects though what makes some people susceptible to hape is currently unknown hape remains the major cause of death related to high altitude exposure with a high mortality rate in the absence of adequate emergency treatment
a high arched palate also termed high vaulted palate is where the palate is unusually high and narrow it is usually a developmental feature that may occur in isolation or in association with a number of conditions it may also be an acquired condition caused by chronic thumb sucking high arched palate may cause narrowed airway and sleep disordered breathing example conditions which may be associated with high arched palate include crouzon syndrome down syndrome apert syndrome treacher collins syndrome marfan syndrome incontinentia pigmenti
in urologic pathology high grade prostatic intraepithelial neoplasia abbreviated hgpin is an abnormality of prostatic glands and believed to precede the development of prostate adenocarcinoma the most common form of prostate cancer it may be referred to simply as prostatic intraepithelial neoplasia abbreviated as pin it is considered to be a pre malignancy or carcinoma in situ of the prostatic glands
high output heart failure is a heart condition that occurs when the cardiac output is higher than normal there is a circulatory overload which may develop pulmonary edema secondary to an elevated diastolic pressure in left ventricle these individuals usually have a normal systolic function but symptoms are those of a heart failure with time this overload causes systolic failure ultimately cardiac output can be reduced to very low levels it may occur in situations with an increased blood volume from excess of water and salt kidney pathology excess of fluid or blood administration treatment with retaining water steroids chronic and severe anemia large arteriovenous fistula or multiple small arteriovenous shunts as in hht or paget s disease of bone some forms of severe liver or kidney disorders hyperthyroidism and wet beriberi and acutely in septic shock especially caused by gram negative bacteria
high pressure nervous syndrome hpns – also known as high pressure neurological syndrome is a neurological and physiological diving disorder that results when a diver descends below about 500 feet 150 m using a breathing gas containing helium the effects experienced and the severity of those effects depend on the rate of descent the depth and percentage of helium helium tremors were first widely described in 1965 by royal navy physiologist peter b bennett who also founded the divers alert network russian scientist g l zal tsman also reported on helium tremors in his experiments from 1961 however these reports were not available in the west until 1967 the term high pressure nervous syndrome was first used by brauer in 1968 to describe the combined symptoms of tremor electroencephalography eeg changes and somnolence that appeared during a 1 189 foot 362 m chamber dive in marseille
high rise syndrome is the phenomenon of cats falling from higher than two stories 7 – 9 m 23 – 30 ft this is generally from high rise buildings or skyscrapers and is also used to refer to the injuries sustained by a cat falling from a great height
a high resistance connection hrc is a problem that results from loose or poor connections in traditional electrical accessories and switchgear which can cause heat to develop capable of starting a fire safety devices such as fuses and residual current devices rcds are unable to detect thermal rise and disconnect the electrical supply because they cannot sense hrc a safety device to prevent hrc operates by effectively monitoring for abnormal thermal rise and will prevent ignition smoke or burning odour of the electrical accessory or electrical installation an example extract from the national union of teachers nut fire safety brief electrical equipment should be regularly maintained by competent people machines should not be allowed to overheat care should be taken not to cover machines while they are switched on as this is particularly likely to cause overheating trailing cables should be regularly checked for damage loose or poor connections in traditional electrical accessories and switchgear can cause heat to develop capable of starting a fire this problem is known as high resistance connection hrc and safety devices such as fuses and residual circuit devices rcds are unable to disconnect the electrical supply because they cannot sense hrc consideration should be given to the installation of a preventative system designed to stop electrical connections and accessories from reaching a temperature which would result in a fire such a device operates by effectively closing a switch at a pre set temperature to prevent ignition smoke or burning odour thermal monitoring of the connection and providing a hrc device close to the probable location where a fault may develop is key to providing early warning or isolation to reduce the risk of fire
high speed pursuit syndrome is a condition that police officers may suffer from during a high speed chase when a police officer gets into a high speed chase they may get so angry and pumped up with energy that the adrenaline rush could cause them to become violent this could ultimately lead them to carry out deadly force on a suspect at the end of or during a police pursuit
high anion gap metabolic acidosis is a form of metabolic acidosis characterized by a high anion gap a medical value based on the concentrations of ions in a patient s serum an anion gap is usually considered to be high if it is over 11 meq l high anion gap metabolic acidosis is caused generally by the body producing too much acid or not producing enough bicarbonate this is often due to an increase in lactic acid or ketoacids or it may be a sign of kidney failure more rarely high anion gap metabolic acidosis may be caused by ingesting methanol or overdosing on aspirin the delta ratio is a formula that can be used to assess elevated anion gap metabolic acidosis and to evaluate whether mixed acid base disorder metabolic acidosis is present the list of agents that cause high anion gap metabolic acidosis is similar to but broader than the list of agents that cause a serum osmolal gap
high energy density physics hedp is a new subfield of physics intersecting nuclear physics astrophysics and plasma physics it has been defined as the physics of matter and radiation at energy densities in excess of about 100 gj m 3
high plains disease is a viral disease afflicting wheat and maize it is caused by the negative sense ssrna virus wheat mosaic virus symptoms are similar to wheat streak mosaic virus with leaf veins showing yellow flecks and streaks followed by leaf margin purpling in maize depending on the timing of infection stunting and death occur plants can be doubly infected with high plains virus and wheat streak mosaic virus
a grease gun injury or injection injury is an injury caused by high pressure injection of oil grease solvents water or even air into the body the most common causes are accidents with grease guns paint sprayers and pressure washers but pinhole leaks in pressurized hydraulic lines occasionally cause this injury additionally there is at least one known case of deliberate self injection with a grease gun although the initial wound often seems minor the unseen internal damage can be severe with hydraulic fluids paint and detergents these injuries are extremely serious as most hydraulic fluids and organic solvents are highly toxic delay in surgical treatment often leads to amputations or death but even with pure water or air these injuries cause compartment syndrome which leads to cell death if surgical intervention is delayed
the highgate vampire was a media sensation surrounding reports of supposed supernatural activity at highgate cemetery in london in the 1970 s
the highland clearances scottish gaelic fuadach nan gàidheal the eviction of the gael was the forced displacement during the 18 th and 19 th centuries of a significant number of people from traditional land tenancies in the scottish highlands where they had practised small scale agriculture it resulted from enclosures of common lands and a change from farming to sheep raising an agricultural revolution largely carried out by hereditary aristocratic landowners the clearances were a complex series of events occurring over more than a hundred years a highland clearance has been defined as an enforced simultaneous eviction of all families living in a given area such as an entire glen the clearances are particularly notorious as a result of the brutality of many evictions at short notice year by year tenants had almost no protection under scots law and the abruptness of the change from the traditional clan system in which reciprocal obligations between the population and their leaders were well recognised the cumulative effect of the clearances and the large scale voluntary emigrations over the same period devastated the cultural landscape of scotland in a way that did not happen in other areas of britain the effect of the clearances was to destroy much of the gaelic culture the clearances resulted in significant emigration of highlanders to the coast the scottish lowlands and further afield to north america and australasia in the early 21 st century many times more descendants of highlanders are found in these diaspora destinations than in scotland
the highland towers collapse was an apartment building collapse that occurred on 11 december 1993 in taman hillview ulu klang selangor malaysia the collapse of block one of the apartments caused the deaths of 48 people and led to the complete evacuation of the remaining two blocks due to safety concerns on 11 december 2010 coinciding with the seventeenth anniversary of the incident aetn s history channel showed an hour long documentary on the tragedy with accounts from the victims their families and former residents
higouménakis sign is a unilateral enlargement of the sternoclavicular portion of the clavicle seen in congenital syphilis it is an end result of neonatal periostitis this sign was first described by george higoumenakis in 1927 in the greek periodical proceedings of the medical society of athens πρακτικά ιατρικής εταιρείας αθηνών he subsequently published the description of the sign in a german article making the sign more known among dermatologists thus the sign was named after george higoumenakis
the hijab protests in azerbaijan are a consequence of recent changes in the formal and social aspects of azerbaijan with the banning of the hijab in schools and universities the hijab ban lead to protests by some religious activists and to their subsequent arrests due to their opposition to the new laws
the hikkake pattern or hikkake is a technical analysis pattern used for determining market turning points and continuations it is a simple pattern that can be observed in market price data using traditional bar charts point and figure charts or japanese candlestick charts the pattern does not belong to the collection of traditional candlestick chart patterns though some have referred to the hikkake pattern as an inside day false breakout or a fakey pattern these are deviations from the original name given to the pattern by daniel l chesler cmt and are not popularly used to describe the pattern for example the name hikkake pattern has been chosen over inside day false breakout or fakey pattern by the majority of book authors who have covered the subject including technical analysis the complete resource for financial market technicians by charles d kirkpatrick and julie r dahlquist and long short market dynamics trading strategies for today s markets by clive m corcoran and diary of a professional commodity trader by peter l brandt
hilbert s eighteenth problem is one of the 23 hilbert problems set out in a celebrated list compiled in 1900 by mathematician david hilbert it asks three separate questions about lattices and sphere packing in euclidean space
hilbert s fifteenth problem is one of the 23 hilbert problems set out in a celebrated list compiled in 1900 by david hilbert the problem is to put schubert s enumerative calculus on a rigorous foundation
hilbert s fifth problem is the fifth mathematical problem from the problem list publicized in 1900 by mathematician david hilbert and concerns the characterization of lie groups the theory of lie groups describes continuous symmetry in mathematics its importance there and in theoretical physics for example quark theory grew steadily in the twentieth century in rough terms lie group theory is the common ground of group theory and the theory of topological manifolds the question hilbert asked was an acute one of making this precise is there any difference if a restriction to smooth manifolds is imposed the expected answer was in the negative the classical groups the most central examples in lie group theory are smooth manifolds this was eventually confirmed in the early 1950 s since the precise notion of manifold was not available to hilbert there is room for some debate about the formulation of the problem in contemporary mathematical language
hilbert s nineteenth problem is one of the 23 hilbert problems set out in a list compiled in 1900 by david hilbert it asks whether the solutions of regular problems in the calculus of variations are always analytic informally and perhaps less directly since hilbert s concept of a regular variational problem identifies precisely a variational problem whose euler – lagrange equation is an elliptic partial differential equation with analytic coefficients hilbert s nineteenth problem despite its seemingly technical statement simply asks whether in this class of partial differential equations any solution function inherits the relatively simple and well understood structure from the solved equation
hilbert s seventeenth problem is one of the 23 hilbert problems set out in a celebrated list compiled in 1900 by david hilbert it concerns the expression of positive definite rational functions as sums of quotients of squares the original question may be reformulated as given a multivariate polynomial that takes only non negative values over the reals can it be represented as a sum of squares of rational functions
hilbert s thirteenth problem is one of the 23 hilbert problems set out in a celebrated list compiled in 1900 by david hilbert it entails proving whether a solution exists for all 7 th degree equations using algebraic variant continuous functions of two arguments it was first presented in the context of nomography and in particular nomographic construction — a process whereby a function of several variables is constructed using functions of two variables hilbert s conjecture that it is not always possible to find such a solution was disproven in 1957
hilbert s twentieth problem is one of the 23 hilbert problems set out in a celebrated list compiled in 1900 by david hilbert it asks whether all boundary value problems can be solved that is do variational problems with certain boundary conditions have solutions
hilbert s twenty fourth problem is a mathematical problem that was not published as part of the list of twenty three problems known as hilbert s problems but was included in david hilbert s original notes the problem asks for a criterion of simplicity in mathematical proofs and the development of a proof theory with the power to prove that a given proof is the simplest possible the 24 th problem was rediscovered by german historian rüdiger thiele in 2000 noting that hilbert did not include the 24 th problem in the lecture presenting hilbert s problems or any published texts hilbert s friends and fellow mathematicians adolf hurwitz and hermann minkowski were closely involved in the project but did not have any knowledge of this problem this is the full text from hilbert s notes given in rüdiger thiele s paper the section was translated by rüdiger thiele the 24 th problem in my paris lecture was to be criteria of simplicity or proof of the greatest simplicity of certain proofs develop a theory of the method of proof in mathematics in general under a given set of conditions there can be but one simplest proof quite generally if there are two proofs for a theorem you must keep going until you have derived each from the other or until it becomes quite evident what variant conditions and aids have been used in the two proofs given two routes it is not right to take either of these two or to look for a third it is necessary to investigate the area lying between the two routes attempts at judging the simplicity of a proof are in my examination of syzygies and syzygies hilbert misspelled the word syzygies between syzygies see hilbert 42 lectures xxxii – xxxix the use or the knowledge of a syzygy simplifies in an essential way a proof that a certain identity is true because any process of addition is an application of the commutative law of addition etc and because this always corresponds to geometric theorems or logical conclusions one can count these processes and for instance in proving certain theorems of elementary geometry the pythagoras theorem theorems on remarkable points of triangles one can very well decide which of the proofs is the simplest author s note part of the last sentence is not only barely legible in hilbert s notebook but also grammatically incorrect corrections and insertions that hilbert made in this entry show that he wrote down the problem in haste — david hilbert hilbert ’ s twenty fourth problem rüdiger thiele american mathematical monthly january 2003
in mathematics the hilbert symbol or norm residue symbol is a function – – from k × × k × to the group of nth roots of unity in a local field k such as the fields of reals or p adic numbers it is related to reciprocity laws and can be defined in terms of the artin symbol of local class field theory the hilbert symbol was introduced by david hilbert sections 64 131 english translation in his zahlbericht with the slight difference that he defined it for elements of global fields rather than for the larger local fields the hilbert symbol has been generalized to higher local fields
hillclimbing is a problem faced by railway systems when a load must be carried up an incline while railways have a great ability to haul very heavy loads this advantage is only significant when the tracks are fairly level as soon as the gradients stiffen the tonnage that can be hauled is greatly diminished
in population genetics the hill – robertson effect or hill – robertson interference is a phenomenon first identified by bill hill and alan robertson in 1966 it provides an explanation as to why there may be an evolutionary advantage to genetic recombination
a hill – sachs lesion or hill – sachs fracture is a cortical depression in the posterolateral head of the humerus it results from forceful impaction of the humeral head against the anteroinferior glenoid rim when the shoulder is dislocated anteriorly
the hilum overlay sign is an imaging appearance on chest radiographs in which the outline of the hilum can be seen at the level of a mass or collection in the mid chest it implies that the mass is not in the middle mediastinum and usually is from the posterior mediastinum
the hindenburg omen is a technical analysis pattern that is said to portend a stock market crash it is named after the hindenburg disaster of may 6 1937 in which the zeppelin airship hindenburg crashed and burned
the hindu milk miracle was a phenomenon considered by many hindus as a miracle which started on 21 september 1995 in which statues of the hindu deity ganesha allegedly drank milk offerings it attracted great attention from people and the media particularly in india the scientific explanation for the incident attested by indian academics was that the material was pulled up from the offering bowls by capillary action
hinduism is a recent phenomenon in togo the religion was introduced by indigenous africans based in accra ghana and a branch of the hindu monastery of africa has been established in lomé
hip dysplasia developmental dysplasia of the hip ddh or congenital dysplasia of the hip cdh is a congenital or developmental deformation or misalignment of the hip joint
a hip fracture is a serious femoral fracture that occurs in the proximal end of the femur the long bone running through the thigh near the hip the term hip fracture is commonly used to refer to four different fracture patterns and is often due to osteoporosis in the vast majority of cases a hip fracture is a fragility fracture due to a fall or minor trauma in someone with weakened osteoporotic bone most hip fractures in people with normal bone are the result of high energy trauma such as car accidents falling from heights or sports injuries in the uk the mortality following a fractured neck of femur is between 20 and 35 within one year in people aged 82 ± 7 years of whom 80 were women
hippocampal replay is a phenomenon observed in rats mice cats rabbits songbirds and monkeys during sleep or awake rest replay refers to the re occurrence of a sequence of cell activations that also occurred during activity but the replay has a much faster time scale it may be in the same order or in reverse cases were also found where a sequence of activations occurs before the actual activity but it is still the same sequence this is called preplay the phenomenon has mostly been observed in the hippocampus a brain region associated with memory and spatial navigation specifically the cells that exhibit this behavior are place cells characterized by reliably increasing their activity when the animal is in a certain location in space during navigation the place cells fire in a sequence according to the path of the animal in a replay instance the cells are activated as if in response to the same spatial path but at a much faster rate than the animal actually moved in
hippocampal sclerosis hs is a neuropathological condition with severe neuronal cell loss and gliosis in the hippocampus specifically in the ca 1 cornu ammonis area 1 and subiculum of the hippocampus it was first described in 1880 by wilhelm sommer hippocampal sclerosis is a frequent pathologic finding in community based dementia hippocampal sclerosis can be detected with autopsy or mri individuals with hippocampal sclerosis have similar initial symptoms and rates of dementia progression to those with alzheimer s disease ad and therefore are frequently misclassified as having alzheimer s disease but clinical and pathologic findings suggest that hippocampal sclerosis has characteristics of a progressive disorder although the underlying cause remains elusive a diagnosis of hippocampal sclerosis has a significant effect on the life of patients because of the notable mortality morbidity and social impact related to epilepsy as well as side effects associated with antiepileptic treatments
hirschsprung s disease hd is a form of megacolon that occurs when part or all of the large intestine or antecedent parts of the gastrointestinal tract have no ganglion cells and therefore cannot function during normal prenatal development cells from the neural crest migrate into the large intestine colon to form the networks of nerves called the myenteric plexus auerbach plexus between the smooth muscle layers of the gastrointestinal tract wall and the submucosal plexus meissner plexus within the submucosa of the gastrointestinal tract wall in hirschsprung s disease the migration is not complete and part of the colon lacks these nerve bodies that regulate the activity of the colon the affected segment of the colon cannot relax and pass stool through the colon creating an obstruction in most affected people the disorder affects the part of the colon that is nearest the anus in rare cases the lack of nerve bodies involves more of the colon in five percent of cases the entire colon is affected stomach and esophagus may be affected too hirschsprung s disease occurs in about one in 5 000 of live births it is usually diagnosed in children and affects boys more often than girls about 10 of cases are familial
hirsuties is the growth in a woman of coarse terminal hair in a male distribution
hirsuties coronae glandis also known as hirsutoid papillomas and pearly penile papules are small protuberances that may form on the ridge of the glans of the human penis they are a harmless anatomical variation though sometimes confused with hpv infection the papules are not a sexually transmitted infection and are not contagious the papules appear as one or several rows of small pearly or flesh colored smooth dome topped bumps situated circumferentially around the corona or sulcus of the glans they may range in size from less than 1 mm to 3 mm as of 1999 different studies have produced estimates of incidence ranging from 8 to 48 percent of all men studies suggest that it occurs more often on younger men and those who have not been circumcised one study found them in 33 3 of males who had not been circumcised and in 7 1 of circumcised males hirsuties coronae glandis are sometimes described as vestigial remnants of penile spines sensitive features found in the same location in other primates in species which retain the full expression of penile spines the spines contribute to sexual pleasure and quicker orgasms a similar expression vestibular papillomatosis of the vulva or hirsuties papillaris vulvae occurs in females and similarly can be misinterpreted as an outbreak of the hpv infection like hirsuties papillaris genitalis it is a normal variation on human anatomy
hirsutism is excessive body hair in women on parts of the body where hair is normally absent or minimal such as on the chin or chest it refers to a male pattern of hair growth that may be a sign of a more serious medical condition especially if it develops well after puberty it can be caused by increased levels of androgen hormones the amount and location of the hair is measured by a ferriman gallwey score it is different than hypertrichosis which is excessive hair growth anywhere on the body
histidinemia also referred to as histidinuria is a rare autosomal recessive metabolic disorder caused by a deficiency of the enzyme histidase histidase is needed for the metabolism of the amino acid histidine although originally thought to be linked to multiple developmental disorders histidinemia is now accepted as a relatively benign disorder leading to a reduction in the prevalence of neonatal screening procedures
histiocytic sarcoma is a tumor derived from histiocytes the tumor is often positive for cd 163 and can appear in the thyroid however in some cases it can also appear in the brain
a histiocytoma is a tumour consisting of histiocytes histiocytes are cells that are a part of the mononuclear phagocytic system a part of the body s immune system that consists of phagocytic cells which are responsible for engulfing solid particles by the cell membrane to form an internal phagosome by phagocytes and protists types include myxofibrosarcoma benign fibrous histiocytoma malignant fibrous histiocytoma histiocytoma dog
a histiocytoma in the dog is a benign tumor it is an abnormal growth in the skin of histiocytes histiocytosis a cell that is part of the immune system a similar disease in humans hashimoto pritzker disease is also a langerhans cell histiocytosis dog breeds that may be more at risk for this tumor include bulldogs american pit bull terriers american staffordshire terriers scottish terriers greyhounds boxers and boston terriers they also rarely occur in goats and cattle
in medicine histiocytosis refers to an excessive number of histiocytes tissue macrophages and is typically used to refer to a group of rare diseases which share this as a characteristic occasionally and confusingly the term histiocytosis is sometimes used to refer to individual diseases according to the histiocytosis association of america 1 in 200 000 children in the united states are born with histiocytosis each year haa also states that most of the people diagnosed with histiocytosis are children under the age of 10 although the disease can afflict adults the university of california san francisco states that the disease usually occurs from birth to age 15 histiocytosis and malignant histiocytosis are both important in veterinary as well as human pathology
histoid leprosy is a skin condition a rare form of multibacillary leprosy
histomoniasis or histomonosis is a disease of birds particularly of chickens and turkeys due to parasitic infection of a protozoan histomonas meleagridis it is a form of blackhead disease in poultry the parasite specifically infects the cecum and liver symptoms of the infection include depression reduced appetite poor growth increased thirst sulphur yellow diarrhoea listlessness and dry ruffled feathers the head may become cyanotic bluish in colour hence the common name of the disease blackhead thus the name blackhead is in all possibility a misnomer for discoloration it is particularly highly fatal in poultry and less in other birds currently no prescription drug is available to treat this disease
histoplasmosis also known as cave disease darling s disease ohio valley disease reticuloendotheliosis spelunker ’ s lung and caver s disease is a disease caused by the fungus histoplasma capsulatum symptoms of this infection vary greatly but the disease affects primarily the lungs occasionally other organs are affected this is called disseminated histoplasmosis and it can be fatal if left untreated histoplasmosis is common among aids patients because of their suppressed immunity in immunocompetent individuals past infection results in partial protection against ill effects if reinfected histoplasma capsulatum is found in soil often associated with decaying bat guano or bird droppings disruption of soil from excavation or construction can release infectious elements that are inhaled and settle into the lung
historically puerperal fever was a devastating disease it affected women within the first three days after childbirth and progressed rapidly causing acute symptoms of severe abdominal pain fever and debility the most common infection causing puerperal fever is genital tract sepsis caused by contaminated medical equipment or unhygienic medical staff who contaminate the mother s genital tract during the delivery other types of infection that can lead to sepsis after childbirth include urinary tract infection breast infection mastitis and respiratory tract infection more common after anaesthesia due to lesions in the trachea puerperal fever is now rare in the west due to improved hygiene during delivery and the few infections that do occur are usually treatable with antibiotics
there were five important periods in the history of canadian newspapers responsible for the eventual development of the modern newspaper these are the transplant period from 1750 – 1800 when printing and newspapers initially came to canada as publications of government news and proclamations followed by the partisan period from 1800 – 1850 when individual printers and editors played a growing role in politics the nation building period from 1850 – 1900 when canadian editors began the work of establishing a common nationalistic view of canadian society the modern period from 1900 to 1980 s saw the professionalization of the industry and the growth of chains current history since the 1990 s saw outside interests take over the chains as they faced new competition from the internet
the city of san antonio is one of the oldest spanish colonization of the european settlements in texas and was for decades its largest city before spanish colonization the site was occupied for thousands of years by varying cultures of indigenous peoples the historic payaya indians were likely those who encountered the first europeans development of the spanish colonial city followed construction of a fort in 1717 a catholic mission and trading post were also established and the town developed as the capital of tejas a province of colonial spain it was the northernmost settlement associated with the hispanic culture of the valley of mexico after mexico achieved independence in 1821 anglo american settlers entered the region from the united states in 1849 anglo americans gained control of san antonio in the fighting that gained independence for the republic of texas in 1845 texas was annexed by the united states of america and became a state
the eponym was bestowed by jean martin charcot 1825 – 93 on behalf of his resident georges albert édouard brutus gilles de la tourette 1859 – 1904 a french physician and neurologist who published an account of nine patients with tourette s in 1885 the possibility that movement disorders including tourette syndrome might have an organic origin was raised when an encephalitis epidemic from 1918 – 1926 led to a subsequent epidemic of tic disorders research in 1972 advanced the argument that tourette s is a neurological rather than psychological disorder since the 1990 s a more neutral view of tourette s has emerged in which biological vulnerability and adverse environmental events are seen to interact findings since 1999 have advanced ts science in the areas of genetics neuroimaging neurophysiology and neuropathology questions remain regarding how best to classify tourette syndrome and how closely tourette s is related to other movement disorders or psychiatric disorders good epidemiologic data is still lacking and available treatments are not risk free and not always well tolerated
atheism derived from the ancient greek ἄθεος atheos meaning without gods godless secular denying or disdaining the gods especially officially sanctioned gods is the absence or rejection of the belief that deities exist the english term was used at least as early as the sixteenth century and atheistic ideas and their influence have a longer history over the centuries atheists have supported their lack of belief in gods through a variety of avenues including scientific philosophical and ideological notions philosophical atheist thought began to appear in europe and asia in the sixth or fifth century bce will durant in his the story of civilization explained that certain pygmy tribes found in africa were observed to have no identifiable cults or rites there were no totems no deities and no spirits their dead were buried without special ceremonies or accompanying items and received no further attention they even appeared to lack simple superstitions according to travelers reports the vedas of ceylon admitted only the possibility that deities might exist but went no further neither prayers nor sacrifices were suggested in any way
diabetes is one of the first diseases described with an egyptian manuscript from c 1500 bce mentioning “ too great emptying of the urine ” the first described cases are believed to be of type 1 diabetes indian physicians around the same time identified the disease and classified it as madhumeha or honey urine noting that the urine would attract ants the term diabetes or to pass through was first used in 250 bce by the greek apollonius of memphis type 1 and type 2 diabetes were identified as separate conditions for the first time by the indian physicians sushruta and charaka in 400 500 ce with type 1 associated with youth and type 2 with obesity the term mellitus or from honey was added by thomas willis in the late 1600 s to separate the condition from diabetes insipidus which is also associated with frequent urination
the history of in vitro fertilisation goes back more than half a century there was a transient biochemical pregnancy reported by australian foxton school researchers in 1953 john rock was the first to extract an intact fertilised egg in 1959 min chueh chang at the worcester foundation proved fertilisation in vitro was capable of proceeding to a birth of a live rabbit chang s discovery was seminal as it clearly demonstrated that oocytes fertilised in vitro were capable of developing if transferred into the uterus and thereby produce live young the first pregnancy achieved through in vitro human fertilisation of a human oocyte was reported in the lancet from the monash university team of carl wood john leeton and alan trounson in 1973 although it lasted only a few days and would today be called a biochemical pregnancy landrum shettles attempted to perform an ivf in 1973 but his departmental chairman interdicted the procedure at the last moment there was also an ectopic pregnancy reported by patrick steptoe and robert edwards in 1976 in 1977 steptoe and edwards successfully carried out a pioneering conception which resulted in the birth of the world s first baby to be conceived by ivf louise brown on 25 july 1978 in oldham general hospital greater manchester uk in october 1978 it was reported that subash mukhopadyay a relatively unknown physician from kolkata india was performing experiments on his own with primitive instruments and a household refrigerator and this resulted in a test tube baby later named as durga alias kanupriya agarwal who was born on 3 october 1978 however state authorities prevented him from presenting his work at scientific conferences and in the absence of scientific evidence his work is not recognised by the international scientific community these days however mukhopadhyay s contribution is acknowledged in works dealing with the subject steptoe and edwards were responsible for the world ’ s first confirmed boy conceived by ivf alastair macdonald born on 14 january 1979 in glasgow a team led by ian johnston and alex lopata were responsible for australia s first baby conceived by ivf candice reed born on 23 june 1980 in melbourne it was the subsequent use of stimulated cycles with clomiphene citrate and the use of human chorionic gonadotrophin hcg to control and time oocyte maturation thus controlling the time of collection that converted ivf from a research tool to a clinical treatment this was followed by a total of 14 pregnancies resulting in nine births in 1981 with the monash university team howard w jones and georgeanna seegar jones at the eastern virginia medical school in norfolk virginia further improved stimulated cycles by incorporating the use of a follicle stimulating hormone uhmg this then became known as controlled ovarian hyperstimulation coh another step forward was the use of gonadotrophin releasing hormone agonists gnrha thus decreasing the need for monitoring by preventing premature ovulation and more recently gonadotrophin releasing hormone antagonists gnrh ant which have a similar function the additional use of the oral contraceptive pill has allowed the scheduling of ivf cycles which has made the treatment far more convenient for both staff and patients the ability to freeze and subsequently thaw and transfer embryos has significantly improved the feasibility of ivf use the other very significant milestone in ivf was the development of the intracytoplasmic sperm injection icsi of single sperms by gianpiero d palermo et al in brussels uz brussel 1992 this has enabled men with minimal sperm production to achieve pregnancies icsi is sometimes used in conjunction with sperm recovery using a testicular fine needle or open testicular biopsy using this method some men with klinefelter s syndrome and so would be otherwise infertile have occasionally been able to achieve pregnancy thus ivf has become the final solution for most fertility problems moving from tubal disease to male factor idiopathic subfertility endometriosis advanced maternal age and anovulation not responding to ovulation induction robert edwards was awarded the 2010 nobel prize in physiology or medicine for the development of in vitro fertilization carl wood was dubbed the father of ivf in vitro fertilisation for having pioneered the use of frozen embryos in the us art cycles started in 2006 resulted in 41 343 births 54 656 infants which is slightly more than 1 of total us births
lesbianism is the sexual and romantic desire between females there are far fewer historical mentions of lesbianism than male homosexuality possibly due to many historical writings and records focusing primarily on men
during the colonial era the indian slavery in alabama soon became surpassed by industrial scale plantation slavery following the patenting of the cotton gin in 1793 the war of 1812 and the defeat and expulsion of the creek nation european american settlement in alabama was intensified as was the presence of slavery on newly established plantations in the territory like its neighbors the alabama territory was fertile ground for the surging cotton crop and soon became one of the major destinations for african american slaves who were being shipped to the extreme southeastern united states most of the settlers came from the nearby states of north carolina south carolina and georgia attracted by the prospect of fertile planting of cotton in the tennessee valley and black belt the plantation system was solidified throughout the first half of the 19 th century and alabama was one of the first seven states to withdraw from the union prior to the american civil war however by the eve of the civil war only a minute portion of the population continued to own slaves as the state had experienced a slave labor decline slavery was officially abolished by the thirteenth amendment which took effect on december 18 1865 slavery had been theoretically abolished by president abraham lincoln s emancipation proclamation which proclaimed in 1863 that only slaves located in territories that were in rebellion from the united states were free since the u s government was not in effective control of many of these territories until later in the war many of these slaves proclaimed to be free by the emancipation proclamation were still held in servitude until those areas came back under union control
superconductivity is the phenomenon of certain materials exhibiting zero electrical resistance and the expulsion of magnetic fields below a characteristic temperature the history of superconductivity began with dutch physicist heike kamerlingh onnes s discovery of superconductivity in mercury in 1911 since then many other superconducting materials have been discovered and the theory of superconductivity has been developed these subjects remain active areas of study in the field of condensed matter physics
synesthesia is a neurological condition in which two or more bodily senses are coupled for example in a form of synesthesia known as grapheme color synesthesia letters or numbers may be perceived as inherently colored historically the most commonly described form of synesthesia or synesthesia like mappings has been between sound and vision e g the hearing of colors in music
the arab – israeli conflict is a modern phenomenon which has its roots in the end of the 19 th century the conflict became a major international issue with the birth of israel in 1948 the arab – israeli conflict has resulted in at least five major wars and a number of minor conflicts it has also been the source of two major palestinian uprisings intifadas
there was a jewish presence in oman for many centuries however the jewish community of the country is no longer existent
there was a small jewish presence of eight families in 1885 when the rebel leader muhammad el mahdi seized control of sudan from its ottoman egyptian rulers the origins of these families and how they settled in sudan is largely unknown in 1885 they were forcibly converted to islam in september 1898 general kitchener and 20 000 anglo egyptian troops including a young winston churchill entered omdurman and regained control of the sudan the country became an anglo egyptian condominium and with this new political status it began to economically flourish the railway line built by the british from cairo to khartoum originally for the military campaign became particularly important for opening up a previously long and difficult route for traders including many jews after anglo egyptian rule had been established six of the formerly jewish families chose to revert to judaism they were quickly joined by many more jewish families who saw the economic opportunities of the developing country from 1900 jews from all over the middle east and north africa began to arrive in sudan via cairo and settle along the nile in the four towns of khartoum khartoum north omdurman and wad medani predominantly small time merchants of textiles silks and gum their businesses soon began to flourish by 1926 the small synagogue they had quickly erected had been replaced by a brand new self funded building and several of its members owned large successful business despite the fact that the jewish community as a whole was split over several towns it was incredibly tight knit a single mohel and shochet served the entire community and at the centre of the social scene was the bustling jewish social club sometimes referred to as the jewish recreational club at its peak between 1930 and 1950 the jewish community in sudan numbered between 500 and 1000 people in 1956 sudan gained independence and hostility towards the jewish community began to grow from 1957 many members of the community began to leave sudan for israel via greece america and other european countries primarily britain and switzerland by 1970 almost all of the jewish community had left sudan in 1977 a large scale air transfer of many human remains from the jewish cemetery in khartoum was organised by several prominent members of the community and reburial was arranged in jerusalem as of 2005 there were at least 15 jewish graves left in the jewish cemetery at khartoum however in recent years even these have been desecrated and the site is now used as a dumping ground for used car parts the site of the much older jewish cemetery in omdurman is unknown the synagogue was sold and demolished in 1986 and a bank now occupies the site
histotoxic hypoxia also called histoxic hypoxia is the inability of cells to take up or utilize oxygen from the bloodstream despite physiologically normal delivery of oxygen to such cells and tissues histotoxic hypoxia results from tissue poisoning such as that caused by cyanide which acts by inhibiting cytochrome oxidase and certain other poisons like hydrogen sulfide byproduct of sewage and used in leather tanning histotoxic hypoxia refers to a reduction in atp production by the mitochondria due to a defect in the cellular usage of oxygen an example of histotoxic hypoxia is cyanide poisoning there is a profound drop in tissue oxygen consumption since the reaction of oxygen with cytochrome c oxidase is blocked by the presence of cyanide there are other chemicals that interrupt the mitochondrial electron transport chain e g rotenone antimycin a and produce effects on tissue oxygenation similar to that of cyanide oxygen extraction decreases in parallel with the lower oxygen consumption with a resulting increase in venous oxygen content and pvo 2 although cyanide stimulates the peripheral respiratory chemoreceptors increasing the inspired oxygen fraction is not helpful since there is already an adequate amount of oxygen which the poisoned cells cannot use
histrionic personality disorder hpd is defined by the american psychiatric association as a personality disorder characterized by a pattern of excessive attention seeking emotions usually beginning in early adulthood including inappropriately seductive behavior and an excessive need for approval histrionic people are lively dramatic vivacious enthusiastic and flirtatious hpd affects four times as many women as men it has a prevalence of 2 – 3 in the general population and 10 – 15 in inpatient and outpatient mental health institutions hpd lies in the dramatic cluster of personality disorders people with hpd have a high need for attention make loud and inappropriate appearances exaggerate their behaviors and emotions and crave stimulation they may exhibit sexually provocative behavior express strong emotions with an impressionistic style and can be easily influenced by others associated features include egocentrism self indulgence continuous longing for appreciation and persistent manipulative behavior to achieve their own needs
hives also known as urticaria is a kind of skin rash with red raised itchy bumps they may also burn or sting often the patches of rash move around typically they last a few days and do not leave any long lasting skin changes fewer than 5 of cases last for more than six weeks the condition frequently recurs hives frequently occur following an infection or as a result of an allergic reaction such as to medication insect bites or food psychological stress cold temperature or vibration may also be a trigger in half of cases the cause remains unknown risk factors include having conditions such as hay fever or asthma diagnosis is typically based on the appearance patch testing may be useful to determine the allergy prevention is by avoiding whatever it is that causes the condition treatment is typically with antihistamines such as diphenhydramine and ranitidine in severe cases corticosteroids or leukotriene inhibitors may also be used keeping the environmental temperature cool is also useful for cases that last more than six weeks immunosuppressants such as ciclosporin may be used about 20 of people are affected cases of short duration occur equally in males and females while cases of long duration are more common in females cases of short duration are more common among children while cases of long duration are more common among those who are middle aged hives have been described at least since the time of hippocrates the term urticaria is from the latin urtica meaning nettle
the hiyama coupling is a palladium catalyzed cross coupling reaction of organosilanes with organic halides used in organic chemistry to form carbon – carbon bonds c c bonds this reaction was discovered in 1988 by tamejiro hiyama and yasuo hatanaka as a method to form carbon carbon bonds synthetically with chemo and regioselectivity this reaction has been applied to the synthesis of various natural products aryl alkenyl or alkynyl aryl alkenyl alkynyl or alkyl cl f or alkyl cl br i or otf
in mathematics the hodge conjecture is a major unsolved problem in the field of algebraic geometry that relates the algebraic topology of a non singular complex algebraic variety and the subvarieties of that variety more specifically the conjecture says that certain de rham cohomology classes are algebraic that is they are sums of poincaré duals of the homology classes of subvarieties it was formulated by the scottish mathematician william vallance douglas hodge as a result of a work in between 1930 and 1940 to enrich the description of de rham cohomology to include extra structure that is present in the case of complex algebraic varieties it received little attention before hodge presented it in an address during the 1950 international congress of mathematicians held in cambridge massachusetts u s the hodge conjecture is one of the clay mathematics institute s millennium prize problems with a prize of 1 000 000 for whoever can prove or disprove the hodge conjecture
hodgkin s lymphoma hl is a type of lymphoma which is generally believed to result from white blood cells of the lymphocyte kind symptoms may include fever night sweats and weight loss often there will be non painful enlarged lymph nodes in the neck under the arm or in the groin those affected may feel tired or be itchy about half of cases of hodgkin s lymphoma are due to epstein – barr virus ebv other risk factors include a family history of the condition and having hiv aids there are two major types of hodgkin lymphoma classical hodgkin lymphoma and nodular lymphocyte predominant hodgkin lymphoma diagnosis is by finding hodgkin s cells such as multinucleated reed – sternberg cells rs cells in lymph nodes hodgkin lymphoma may be treated with chemotherapy radiation therapy and stem cell transplant the choice of treatment often depends on how advanced the cancer is and whether or not it has favorable features in early disease a cure is often possible the percentage of people who survive five years in the united states is 86 for those under the age of 20 rates of survival are 97 radiation and some chemotherapy drugs however increase the risk of other cancers heart disease or lung disease over the subsequent decades in 2013 about 725 000 people had hodgkin s lymphoma and 24 000 died in the united states 0 2 of people are affected at some point in their life the most common age of diagnosis is between 20 and 40 years old it was named after the english physician thomas hodgkin who first described the condition in 1832
the hoesch reaction or houben – hoesch reaction is an organic reaction in which a nitrile reacts with an arene compound to form an aryl ketone the reaction is a type of friedel crafts acylation with hydrogen chloride and a lewis acid catalyst an example is the synthesis of 1 2 4 6 trihydroxyphenyl ethanone from phloroglucinol a ketimine is isolated as an intermediate reaction product the attacking electrophile is possibly a species of the type r c nhcl − the arene must be electron rich i e phenol or aniline type a related reaction is the gattermann reaction in which hydrocyanic acid not a nitrile is used the reaction is named after kurt hoesch and josef houben who reported about this new reaction type in respectively 1915 and 1926
a hoffa fracture is an intra articular supracondylar distal femoral fracture characterized by a fracture in the coronal plane it is named for albert hoffa
the hofmann rearrangement is the organic reaction of a primary amide to a primary amine with one fewer carbon atoms the reaction is named after its discoverer august wilhelm von hofmann this reaction is also sometimes called the hofmann degradation or the harmon process and should not be confused with the hofmann elimination
the hofmann – löffler reaction also referred to as hofmann – löffler – freytag reaction löffler – freytag reaction löffler – hofmann reaction as well as löffler s method is an organic reaction in which a cyclic amine 2 pyrrolidine or in some cases piperidine is generated by thermal or photochemical decomposition of n halogenated amine 1 in the presence of a strong acid concentrated sulfuric acid or concentrated cf 3 co 2 h the hofmann – löffler – freytag reaction proceeds via an intramolecular hydrogen atom transfer to a nitrogen centered radical and is an example of a remote intramolecular free radical c – h functionalization file general scheme gif
the hofmann – martius rearrangement in organic chemistry is a rearrangement reaction converting an n alkylated aniline to the corresponding ortho and or para aryl alkylated aniline the reaction requires heat and the catalyst is an acid like hydrochloric acid the hofmann – martius rearrangement when the catalyst is a metal halide the reaction is also called the reilly – hickinbottom rearrangement the reaction is also known to work for aryl ethers and two conceptually related reactions are the fries rearrangement and the fischer – hepp rearrangement its reaction mechanism centers around dissociation of the reactant with the positively charged organic residue r attacking the aniline ring in a friedel – crafts alkylation in one study this rearrangement was applied to a 3 n ch 3 c 6 h 5 2 oxindole hofmann – martius rearrangement of 3 n aryl 2 oxindoles
hog maw is the stomach of a pig more specifically it is the exterior muscular wall of the stomach organ with interior lining mucosa removed which contains no fat if cleaned properly it can be found in soul food chinese pennsylvania dutch mexican portuguese and italian dishes in addition it can be prepared in various ways including stewed fried baked and broiled
in medicine the holdsworth fracture is an unstable fracture dislocation of the thoraco lumbar junction of the spine the injury comprises a fracture through a vertebral body rupture of the posterior spinal ligaments and fractures of the facet joints the injury was described by frank wild holdsworth in 1963 he described the mechanism of this injury as a flexion rotation injury and said that the unstable fracture dislocation should be treated by fusion of the two affected vertebrae
holiday heart syndrome is an irregular heartbeat pattern presented in individuals who are otherwise healthy coined in 1978 the term is defined as abnormal heart rhythms sometimes following excessive alcohol consumption usually temporary holiday heart syndrome can be the result of stress dehydration and drinking alcohol it is sometimes associated with binge drinking common during the holiday season the condition can also occur when individuals consume only moderate amounts of alcohol irregular heartbeats can be serious if palpitations continue for longer than a few hours patients should seek medical attention atrial fibrillation is the most common arrhythmia in holiday heart syndrome symptoms usually resolve themselves within 24 hours
a hollenhorst plaque aka eickenhorst plaque is a cholesterol embolus that is seen in a blood vessel of the retina
holmes heart is a rare congenital heart disease with absence of the inflow tract of the morphologically right ventricle rv and hence a single left ventricle lv the great vessels are normally related with the pulmonary artery arising from the small infundibular outlet chamber and the aorta arising from the single left ventricle the holmes heart is named after dr andrew f holmes who first described an autopsy specimen of this congenital heart defect in 1824 dr holmes later became the first dean of the medical faculty at mcgill university in canada
holocarboxylase synthetase deficiency is an inherited metabolic disorder in which the body is unable to use the vitamin biotin effectively this disorder is classified as a multiple carboxylase deficiency a group of disorders characterized by impaired activity of certain enzymes that depend on biotin symptoms are very similar to biotinidase deficiency and treatment – large doses of biotin – is also the same
in mathematics and more specifically in analysis a holonomic function is a smooth function in several variables that is a solution of a system of linear homogeneous differential equations with polynomial coefficients and satisfies a suitable dimension condition in terms of d modules theory more precisely a holonomic function is an element of a holonomic module of smooth functions holonomic functions can also be described as differentiably finite functions also known as d finite functions when a power series in the variables is the taylor expansion of a holonomic function the sequence of its coefficients in one or several indices is also called holonomic holonomic sequences are also called p recursive sequences they are defined recursively by multivariate recurrences satisfied by the whole sequence and by suitable specializations of it the situation simplifies in the univariate case any univariate sequence that satisfies a linear homogeneous recurrence relation with polynomial coefficients or equivalently a linear homogeneous difference equation with polynomial coefficients is holonomic
in differential geometry the holonomy of a connection on a smooth manifold is a general geometrical consequence of the curvature of the connection measuring the extent to which parallel transport around closed loops fails to preserve the geometrical data being transported for flat connections the associated holonomy is a type of monodromy and is an inherently global notion for curved connections holonomy has nontrivial local and global features any kind of connection on a manifold gives rise through its parallel transport maps to some notion of holonomy the most common forms of holonomy are for connections possessing some kind of symmetry important examples include holonomy of the levi civita connection in riemannian geometry called riemannian holonomy holonomy of connections in vector bundles holonomy of cartan connections and holonomy of connections in principal bundles in each of these cases the holonomy of the connection can be identified with a lie group the holonomy group the holonomy of a connection is closely related to the curvature of the connection via the the study of riemannian holonomy has led to a number of important developments the holonomy was introduced by in order to study and classify symmetric spaces it was not until much later that holonomy groups would be used to study riemannian geometry in a more general setting in 1952 georges de rham proved the de rham decomposition theorem a principle for splitting a riemannian manifold into a cartesian product of riemannian manifolds by splitting the tangent bundle into irreducible spaces under the action of the local holonomy groups later in 1953 m berger classified the possible irreducible holonomies the decomposition and classification of riemannian holonomy has applications to physics and to string theory
holoprosencephaly hpe once known as arhinencephaly is a cephalic disorder in which the prosencephalon the forebrain of the embryo fails to develop into two hemispheres normally the forebrain is formed and the face begins to develop in the fifth and sixth weeks of human pregnancy the condition also occurs in other species the condition can be mild or severe according to the national institute of neurological disorders and stroke ninds in most cases of holoprosencephaly the malformations are so severe that babies die before birth when the embryo s forebrain does not divide to form bilateral cerebral hemispheres the left and right halves of the brain it causes defects in the development of the face and in brain structure and function in less severe cases babies are born with normal or near normal brain development and facial deformities that may affect the eyes nose and upper lip
a holstein – lewis fracture is a fracture of the distal third of the humerus resulting in entrapment of the radial nerve
the holtzman effect is a fictional scientific phenomenon in the dune universe created by frank herbert beginning with the 1965 novel dune the effect is never explained in detail but it makes among other things defensive force shields and instantaneous space travel possible frank herbert was inconsistent with the spelling of holtzman resulting in the variant spellings holtzmann 1976 s children of dune and holzmann 1985 s chapterhouse dune this may be intentional as herbert mutated other words and names over the several millennia the dune series spans such as the change of arrakis to rakis and caladan to dan beginning with heretics of dune 1984 according to the legends of dune prequel trilogy by brian herbert and kevin j anderson 2002 – 2004 the holtzman effect is named after the scientist who discovered it though for many of its applications holtzman in fact takes credit for the mathematical theories of his assistant norma cenva
holt – oram syndrome is an autosomal dominant disorder that affects bones in the arms and hands the upper limbs and may also cause heart problems the syndrome includes an absent radial bone in the arms an atrial septal defect and a first degree heart block holt – oram syndrome is considered to be a phenocopy of thalidomide since both the genetic disorder and the teratogenic effects have similar presentations in individuals
home accessories are furniture items which are easy to replace and easy to move and include almost any items that aren t strictly functionally necessary in the decorated space these accessories include such items as curtains sofa sets cushions tablecloths and decorative craft products decorative wrought iron and so on these items are commonly used in indoor furnishings and layout and can include cloth items paintings and plants
homelessness is the condition of people without a permanent dwelling such as a house or apartment people who are homeless are most often unable to acquire and maintain regular safe secure and adequate housing the legal definition of homeless varies from country to country or among different jurisdictions in the same country or region the term homeless may also include people whose primary night time residence is in a homeless shelter a warming center a domestic violence shelter long term residence in a motel a vehicle including recreational vehicles and campers squatting cardboard boxes a tent city tarpaulins shanty town structures made of discarded building materials or other ad hoc housing situations according to the uk homelessness charity crisis a home is not just a physical space it also provides roots identity security a sense of belonging and a place of emotional wellbeing american government homeless enumeration studies also include people who sleep in a public or private place not designed for use as a regular sleeping accommodation for human beings there are a number of organizations who provide help for the homeless in 2005 an estimated 100 million 1 in 65 people worldwide were homeless and as many as 1 billion people live as squatters refugees or in temporary shelter all lacking adequate housing in western countries the large majority of homeless are men 75 – 80 with single males particularly overrepresented most countries provide a variety of services to assist homeless people these services often provide food shelter beds and clothing and may be organized and run by community organizations often with the help of volunteers or by government departments or agencies these programs may be supported by the government charities churches and individual donors many cities also have street newspapers which are publications designed to provide employment opportunity to homeless people while some homeless have jobs some must seek other methods to make a living begging or panhandling is one option but is becoming increasingly illegal in many cities people who are homeless may have additional conditions such as physical or mental health issues or substance addiction these issues make resolving homelessness a challenging policy issue
in the mathematical field of topology a homeomorphism or topological isomorphism or bi continuous function is a continuous function between topological spaces that has a continuous inverse function homeomorphisms are the isomorphisms in the category of topological spaces — that is they are the mappings that preserve all the topological properties of a given space two spaces with a homeomorphism between them are called homeomorphic and from a topological viewpoint they are the same the word homeomorphism comes from the greek words ὅμοιος homoios similar and μορφή morphē shape form roughly speaking a topological space is a geometric object and the homeomorphism is a continuous stretching and bending of the object into a new shape thus a square and a circle are homeomorphic to each other but a sphere and a torus are not an often repeated mathematical joke is that topologists can t tell the difference between a coffee cup and a donut since a sufficiently pliable donut could be reshaped to the form of a coffee cup by creating a dimple and progressively enlarging it while preserving the donut hole in a cup s handle
a homeostatic emotion primordial emotion or primordial feeling is an attention demanding sensation and motivation e g thirst pain fatigue itch evoked by an internal body state that drives behavior drinking withdrawing resting and scratching in these examples aimed at maintaining the body s internal milieu in its ideal state derek denton defines primordial emotion as the subjective element of the instincts which are the genetically programmed behaviour patterns which contrive homeostasis they include thirst hunger for air hunger for food pain hunger for specific minerals etc there are two constituents of a primordial emotion the specific sensation which when severe may be imperious and the compelling intention for gratification by a consummatory act bud craig argues that humans and anthropoid primates form an image of all of the body s unique homeostatic sensations in the brain s primary interoceptive cortex located in the dorsal posterior insula this image is mirrored re represented in the mid and anterior insula and the anterior insula s image modulated by input from cognitive affective and reward related circuits embodies conscious awareness of the whole body s homeostatic state a sensation re represented in the anterior insula and that sensation s related motivation hosted in the anterior cingulate cortex form a homeostatic emotion antonio damasio uses primordial feeling to denote this class of sensations motivations in his 2010 book self comes to mind constructing the conscious brain
in game theory the homicidal chauffeur problem is a mathematical pursuit problem which pits a hypothetical runner who can only move slowly but is highly maneuverable against the driver of a motor vehicle which is much faster but far less maneuverable who is attempting to run him down both runner and driver are assumed to never tire the question to be solved is under what circumstances and with what strategy can the driver of the car guarantee that he can always catch the pedestrian or the pedestrian guarantee that he can indefinitely elude the car the problem was proposed by rufus isaacs in a 1951 report for the rand corporation and in the book differential games the homicidal chauffeur problem is a classic example of a differential game played in continuous time in a continuous state space the calculus of variations and level set methods can be used as a mathematical framework for investigating solutions of the problem although the problem is phrased as a recreational problem it is an important model problem for mathematics used in a number of real world applications a discrete version of the problem was described by martin gardner in his book mathematical carnival chapter 16 where a squad car of speed 2 chases a crook of speed 1 on a rectangular grid where the squad car but not the crook is constrained not to make left hand turns or u turns
homicidal ideation is a common medical term for thoughts about homicide there is a range of homicidal thoughts which spans from vague ideas of revenge to detailed and fully formulated plans without the act itself many people who have homicidal ideation do not commit homicide 50 91 of people surveyed on university grounds in various places in the usa admit to having had a homicidal fantasy homicidal ideation is common accounting for 10 17 of patient presentations to psychiatric facilities in the usa homicidal ideation is not a disease itself but may result from other illnesses such as delirium and psychosis psychosis which accounts for 89 of admissions with homicidal ideation in one us study includes substance induced psychosis e g amphetamine psychosis and the psychoses related to schizophreniform disorder and schizophrenia delirium is often drug induced or secondary to general medical illness es see icd 10 chapter v mental and behavioural disorders f 05 it may arise in association with personality disorders or it may occur in people who do not have any detectable illness in fact surveys have shown that the majority of people have had homicidal fantasies at some stage in their life many theories have been proposed to explain this
homing is the inherent ability of an animal to navigate towards an original location through unfamiliar areas this location may be either a home territory or a breeding spot
homing is the phenomenon whereby cells migrate to the organ of their origin by homing transplanted hematopoietic cells are able to travel to and engraft or establish residence in the bone marrow various chemokines and receptors are involved in the homing of hematopoietic stem cells
classical homocystinuria also known as cystathionine beta synthase deficiency or cbs deficiency is an inherited disorder of the metabolism of the amino acid methionine often involving cystathionine beta synthase it is an inherited autosomal recessive trait which means a child needs to inherit a copy of the defective gene from both parents to be affected
homogeneous broadening is a type of emission spectrum broadening in which all atoms radiating from a specific level under consideration radiate with equal opportunity if an optical emitter e g an atom shows homogeneous broadening its spectral linewidth is its natural linewidth with a lorentzian profile
mobility can be difficult for people with homonymous hemianopsia “ patients frequently complain of bumping into obstacles on the side of the field loss thereby bruising their arms and legs ” 3 people with homonymous hemianopsia often experience discomfort in crowds “ a patient with this condition may be unaware of what he or she cannot see and frequently bumps into walls trips over objects or walks into people on the side where the visual field is missing ” 5 a related phenomenon is hemispatial neglect the possible neglect of the right or left the patient is not conscious of its existence the right side of the face is not shaven make up is applied to one side of the face only and only half of a plate of food is eaten this however is not necessarily due to a sensory abnormality and is therefore distinct from hemianopsia
in mathematics in particular in homotopy theory within algebraic topology the homotopy lifting property also known as the right lifting property or the covering homotopy axiom is a technical condition on a continuous function from a topological space e to another one b it is designed to support the picture of e above b by allowing a homotopy taking place in b to be moved upstairs to e for example a covering map has a property of unique local lifting of paths to a given sheet the uniqueness is because the fibers of a covering map are discrete spaces the homotopy lifting property will hold in many situations such as the projection in a vector bundle fiber bundle or fibration where there need be no unique way of lifting
the honda point disaster was the largest peacetime loss of u s navy ships on the evening of september 8 1923 seven destroyers while traveling at 20 knots 37 km h ran aground at honda point a few miles from the northern side of the santa barbara channel off point arguello on the coast in santa barbara county california two other ships grounded but were able to maneuver free of the rocks twenty three sailors died in the disaster
honeycombing or honeycomb lung is the radiological appearance seen with widespread fibrosis and is defined by the presence of small cystic spaces with irregularly thickened walls composed of fibrous tissue dilated and thickened terminal and respiratory bronchioles produce cystic airspaces giving honeycomb appearance on chest x ray honeycomb cysts often predominate in the peripheral and pleural subpleural lung regions regardless of their cause subpleural honeycomb cysts typically occur in several contiguous layers this finding can allow honeycombing to be distinguished from paraseptal emphysema in which subpleural cysts usually occur in a single layer
honeymoon rhinitis is a condition in which the sufferer experiences nasal congestion during sexual intercourse the condition appears to be genetically determined and caused by the presence in the nose of erectile tissue which may become engorged during sexual arousal as a side effect of the signals from the autonomic nervous system that trigger changes in the genitals of both men and women a related condition called sexually induced sneezing also exists where people sneeze sometimes uncontrollably when engaging in or even thinking about sexual activity a phenomenon presumably related to honeymoon rhinitis is the occurrence of nasal congestion as a reported side effect of viagra use
the hong – ou – mandel effect is a two photon interference effect in quantum optics which was demonstrated by three physicists chung ki hong zhe yu ou and leonard mandel in 1987 from the university of rochester the effect occurs when two identical single photon waves enter a 50 50 beam splitter one in each input port when both photons are identical they will extinguish each other if they become more distinguishable the probability of detection will increase in this way the interferometer can measure accurately bandwidth path lengths and timing
hoof wall separation disease hwsd is an autosomal recessive genetic hoof disease in horses research is being carried out at among others uc davis school of veterinary medicine in davis in california the disease has been found in connemara ponies and was earlier referred to as hoof wall separation syndrome hwss
hookworm infection also known as hookworm disease is an infection by a parasitic bloodsucking roundworm hookworm infections include ancylostomiasis and necatoriasis these worms live in the small intestine of their host which may be a bird or a mammal such as a dog cat or human hookworm infection in pregnancy can cause retarded growth of the fetus premature birth and a low birth weight hookworms in children can cause intellectual cognitive and growth problems two species of hookworms commonly infect humans ancylostoma duodenale and necator americanus a duodenale predominates in the middle east north africa india and formerly in southern europe while n americanus predominates in the americas sub saharan africa southeast asia china and indonesia a tubaeforme infects cats a caninum infects dogs and a braziliense and uncinaria stenocephala infect both cats and dogs hookworms are much smaller than the giant roundworms ascaris lumbricoides and so cause less tissue damage and obstruction the most significant risk of hookworm infection is anemia secondary to loss of iron and protein in the gut the worms suck blood voraciously and damage the mucosa however the blood loss in the stools is not visibly apparent hookworm infection affects over half a billion people globally it is a leading cause of maternal and child morbidity in the developing countries of the tropics and subtropics in developed countries hookworm infection is rarely fatal but anemia can be significant in a heavily infected individual hookworm infection is a soil transmitted helminthiasis and therefore classified as a neglected tropical disease ancylostomiasis is the disease caused when ancylostoma duodenale hookworms present in large numbers produce an iron deficiency anemia by sucking blood from the host s intestinal walls
hoose is a disease of sheep cattle goats and swine caused by the presence of various species of nematodes of the genera dictyocaulus metastrongylus and protostrongylus in the bronchial tubes or in the lungs it is marked by cough dyspnea anorexia and constipation also called verminous bronchitis hoose is essentially an infantile disease almost always afflicting animals under one year of age
hopkins syndrome is a neurological disorder its cause has not been established but its association with asthma exacerbations usually with a respiratory infection as a trigger has led to suspicion that the initial viral insult that causes the respiratory infection is also implicated in the subsequent paralysis herpes simplex virus type i dna has been found in the cerebrospinal fluid of at least one patient diagnosed with hopkins syndrome in several cases anti viral antibody titers for echovirus enterovirus coxsackievirus and poliovirus types 1 2 and 3 were specifically sought all were negative there is one reported case in which mycoplasma pneumoniae infection was found in the patient the syndrome appears to involve the spinal cord specifically the anterior horn cells subserving the affected muscles are often damaged the evidence for anterior horn cell involvement comes from radiological and electromyographical studies in one case a biopsy of an affected muscle revealed scattered atrophic fibers indicating lesions in the anterior horn cells of the spinal cord as the illness is rare no treatments have been subjected to a randomized controlled trial acyclovir steroids and therapeutic plasma exchange have been tried one report suggests that the latter is more effective than steroidal therapy the prognosis for recovery of function of the affected limbs is generally considered to be poor
hori s nevus also known as acquired bilateral nevus of ota like macules is a cutaneous condition characterized by multiple brown – gray to brown – blue macules primarily in the malar region of the face
the horizon effect also known as the horizon problem is a problem in artificial intelligence where in many games the number of possible states or positions is immense and computers can only feasibly search a small portion of it typically a few plies down the game tree thus for a computer searching only five plies there is a possibility that it will make a detrimental move but the effect is not visible because the computer does not search to the depth of the error i e beyond its horizon when evaluating a large game tree using techniques such as minimax or alpha beta pruning search depth is limited for feasibility reasons however evaluating a partial tree may give a misleading result when a significant change exists just over the horizon of the search depth the computational device falls victim to the horizon effect the horizon effect can be mitigated by extending the search algorithm with a quiescence search this gives the search algorithm ability to look beyond its horizon for a certain class of moves of major importance to the game state such as captures in chess rewriting the evaluation function for leaf nodes and or analyzing more nodes will solve many horizon effect problems
the horizon problem sometimes called the homogeneity problem is a problem with the standard cosmological model of the big bang which was identified in the late 1960 s primarily by charles misner it points out that different regions of the universe have not contacted each other because of the great distances between them but nevertheless they have the same temperature and other physical properties this should not be possible given that the transfer of information or energy heat etc can occur at most at the speed of light two theories that attempt to solve the horizon problem are the theory of cosmic inflation and variable speed of light
a gaze palsy is the paresis of conjugate eye movements horizontal gaze palsy may be caused by lesions in the cerebral hemispheres which cause paresis of gaze away from the side of the lesion or from brain stem lesions which if they occur below the crossing of the fibers from the frontal eye fields in the caudal midbrain will cause weakness of gaze toward the side of the lesion another way to remember this is that patients with hemisphere lesions look toward their lesion while patients with pontine gaze palsies look away from their lesions note that patients with gaze palsy still have conjugate eye movements and therefore do not complain of diplopia the human robo gene acts as a receptor for a midline repulsive cue when robo is mutated the longitudinal tract formation is disrupted and therefore normal neuronal connections cannot form this leads to the reduced hindbrain volume and scoliosis which are common symptoms of horizontal gaze palsy
hormonal imprinting hi is a phenomenon which takes place at the first encounter between a hormone and its developing receptor in the critical periods of life in unicellulars during the whole life and determines the later signal transduction capacity of the cell the most important period in mammals is the perinatal one however this system can be imprinted at weaning at puberty and in case of continuously dividing cells during the whole life faulty imprinting is caused by drugs environmental pollutants and other hormone like molecules present in excess at the critical periods with lifelong receptorial morphological biochemical and behavioral consequences hi is transmitted to the hundreds of progeny generations in unicellulars and as proved to a few generations also in mammals
a hormone receptor positive tumor is a tumor which consists of cells that express receptors for certain hormones the term most commonly refers to estrogen receptor positive tumors i e tumors that contain estrogen receptor positive cells but can also include progesterone receptor positive tumors estrogen receptor positive tumors depend on the presence of estrogen for ongoing proliferation
hormone replacement therapy hrt in menopause is medical treatment in surgically menopausal perimenopausal and postmenopausal women its goal is to mitigate discomfort caused by diminished circulating estrogen and progesterone hormones in menopause combination hrt is often recommended as it decreases the amount of endometrial hyperplasia and cancer associated with unopposed estrogen therapy the main hormones involved are estrogen progesterone and progestin some recent therapies include the use of androgens as well the 2002 women s health initiative of the national institutes of health found disparate results for all cause mortality with hormone replacement finding it to be lower when hrt was begun earlier between age 50 59 but higher when begun after age 60 in older patients there was an increased incidence of breast cancer heart attacks and stroke although a reduced incidence of colorectal cancer and bone fracture some of the whi findings were again found in a larger national study done in the uk known as the million women study as a result of these findings the number of women taking hormone treatment dropped precipitously the women s health initiative recommended that women with non surgical menopause take the lowest feasible dose of hrt for the shortest possible time to minimize associated risks the current indications for use from the u s food and drug administration include short term treatment of menopausal symptoms such as vasomotor hot flashes or urogenital atrophy and prevention of osteoporosis in 2012 the united states preventive task force concluded that the harmful effects of combined estrogen and progestin are likely to exceed the chronic disease prevention benefits in most women a consensus expert opinion published by the endocrine society stated that when taken during perimenopause or the initial years of menopause hormonal therapy carries significantly fewer risks than previously published and reduces all cause mortality in most patient scenarios the american association of clinical endocrinology also released a position statement in 2009 that approved of hrt in appropriate clinical scenarios
horner s syndrome is a combination of symptoms that arises when a group of nerves known as the sympathetic trunk is damaged the signs and symptoms occur on the same side as the lesion of the sympathetic trunk it is characterized by miosis a constricted pupil ptosis a weak droopy eyelid apparent anhidrosis decreased sweating with or without enophthalmos inset eyeball the nerves of the sympathetic trunk arise from the spinal cord in the chest and from there ascend to the neck and face the nerves are part of the sympathetic nervous system a part of the autonomic or involuntary nervous system once the syndrome has been recognized medical imaging and response to particular eye drops may be required to identify the location of the problem and the underlying cause
the horner – wadsworth – emmons reaction or hwe reaction is a chemical reaction used in organic chemistry of stabilized phosphonate carbanions with aldehydes or ketones to produce predominantly e alkenes the horner – wadsworth – emmons reaction in 1958 leopold horner published a modified wittig reaction using phosphonate stabilized carbanions william s wadsworth and william d emmons further defined the reaction in contrast to phosphonium ylides used in the wittig reaction phosphonate stabilized carbanions are more nucleophilic but less basic likewise phosphonate stabilized carbanions can be alkylated unlike phosphonium ylides the dialkylphosphate salt byproduct is easily removed by aqueous extraction several reviews have been published
the hornslet wind turbine collapse was a spectacular collapse of a wind turbine on february 22 2008 it is one of only a few structural collapses that have been captured on film
in ophthalmology horror fusionis is a condition in which the eyes have an unsteady deviation with the extraocular muscles performing spasm like movements that continuously shift the eyes away from the position in which they would be directed to the same point in space giving rise to diplopia even when the double vision images are made to nearly overlap using optical means such as prisms the irregular movements prevent binocular fusion the name horror fusionis latin phrase literally meaning fear of fusion arises from the notion that the brain is or at least appears to be actively preventing binocular fusion the condition is an extreme type of binocular fusion deficiency
horse ripping or horse slashing is an animal cruelty phenomenon involving serious injuries in horses often involving mutilation of their genitalia and slashing of the flank or neck it has not been established however how often these injuries are caused by human cruelty horse ripping is not an entirely neutral term since it implies there is always a human act behind the mutilations
horseshoe kidney also known as ren arcuatus in latin renal fusion or super kidney is a congenital disorder affecting about 1 in 600 people more common in men in this disorder the patient s kidneys fuse together to form a horseshoe shape during development in the womb the fused part is the isthmus of the horseshoe kidney fusion abnormalities of the kidney can be categorized into two groups horseshoe kidney and crossed fused ectopia the horseshoe kidney is the most common renal fusion anomaly
the hosford yield criterion is a function that is used to determine whether a material has undergone plastic yielding under the action of stress
hospital acquired infection hai — also known as nosocomial infection — is an infection that is contracted from the environment or staff of a healthcare facility it can be spread in the hospital environment nursing home environment rehabilitation facility clinic or other clinical settings infection is spread to the susceptible patient in the clinical setting by a number of means health care staff can spread infection in addition to contaminated equipment bed linens or air droplets the infection can originate from the outside environment another infected patient staff that may be infected or in some cases the source of the infection cannot be determined in some cases the microorganism originates from the patient s own skin microbiota becoming opportunistic after surgery or other procedures that compromise the protective skin barrier though the patient may have contracted the infection from their own skin the infection is still considered nosocomial since it develops in the health care setting in the united states the centers for disease control and prevention estimated roughly 1 7 million hospital associated infections from all types of microorganisms including bacteria and fungi combined cause or contribute to 99 000 deaths each year in europe where hospital surveys have been conducted the category of gram negative infections are estimated to account for two thirds of the 25 000 deaths each year nosocomial infections can cause severe pneumonia and infections of the urinary tract bloodstream and other parts of the body many types are difficult to treat with antibiotics in addition antibiotic resistance can complicate treatment
hospital furunculosis is a cutaneous condition that can be epidemic in the hospital setting characterized histopathologically by a deep abscess with both lymphocytes and neutrophils
hospitalism or anaclitic depression in its sublethal form was a pediatric diagnosis used in the 1930 s to describe infants who wasted away while in hospital the symptoms could include retarded physical development and disruption of perceptual motor skills and language it is now understood that this wasting disease was mostly caused by a lack of social contact between the infant and its caregivers infants in poorer hospitals were less subject to this disease since those hospitals could not afford incubators which meant that the hospital staff regularly held the infants the term was used by the psychotherapist rené spitz in 1945 but its origins are older than this it occurs in an editorial in archives on pediatrics as early as 1897 it appears under adjustment disorders at f 43 2 in the world health organization s classification of diseases icd 10
hot carrier injection hci is a phenomenon in solid state electronic devices where an electron or a “ hole ” gains sufficient kinetic energy to overcome a potential barrier necessary to break an interface state the term hot refers to the effective temperature used to model carrier density not to the overall temperature of the device since the charge carriers can become trapped in the gate dielectric of a mos transistor the switching characteristics of the transistor can be permanently changed hot carrier injection is one of the mechanisms that adversely affects the reliability of semiconductors of solid state devices
in aviation hot and high is a condition of low air density due to high ambient temperature and high airport elevation air density decreases with increasing temperature and altitude at any given true airspeed lower air density reduces the amount of lift generated by the wings or the rotors of an aircraft which may hamper an aircraft s performance and hence its ability to operate safely the reduced density also reduces the performance of the aircraft s engine compounding the effect aviators gauge air density by calculating the density altitude hot and high do not have to be mutually inclusive of one another though this tends to be the exception if an airport is especially hot or high the other condition need not be present temperatures can change from one hour to the next while the elevation of an airport always remains constant the fact that temperatures decrease at higher elevations mitigates the hot and high effect to a certain extent
the hot chocolate effect also known as the allassonic effect is a phenomenon of wave mechanics first documented in 1982 by frank crawford where the pitch heard from tapping a cup of hot liquid rises after the addition of a soluble powder it was first observed in the making of hot chocolate or instant coffee but also occurs in other situations such as adding salt to supersaturated hot water or cold beer recent research has found many more substances which create the effect even in initially non supersaturated liquids it can be observed by pouring hot milk into a mug stirring in chocolate powder and tapping the bottom of the mug with a spoon while the milk is still in motion the pitch of the taps will increase progressively with no relation to the speed or force of tapping subsequent stirring of the same solution without adding more chocolate powder will gradually decrease the pitch again followed by another increase this process can be repeated a number of times until equilibrium has been reached upon initial stirring entrained gas bubbles reduce the speed of sound in the liquid lowering the frequency as the bubbles clear sound travels faster in the liquid and the frequency increases
in the study of financial markets hot equity periods or hot issue periods are periods of time in which many firms perform initial public offering ipo of their equity firms in modern economies often finance themselves by the issuance in public markets of shares also called equity it turns out that these initial public offerings tend to cluster in time so that one year many firms might be doing an ipo while next year very few firms do it these periods in which many firms perform an ipo are called hot equity periods
a hot quadrate sign is an imaging appearance of increased enhancement in ct scans or mri or radiotracer accumulation in nuclear medicine in which there is enhancement of the quadrate lobe of the liver the appearance is an indirect reflection of the collateralized flow of svc syndrome in which occlusion of the superior vena cava leads to preferential flow to the quadrate the sign is similar in mechanism but distinct in significance from the hot caudate sign in which the caudate lobe of the liver shows preferential enhancement or radiotracer accumulation with hepatic vein occlusion in budd chiari syndrome in the latter the caudate shows preferential flow because its direct drainage into the inferior vena cava remains unobstructed as opposed to the remnant liver which drains into the hepatic vein
in veterinary medicine a hot spot or acute pyoderma acute moist pyotraumatic dermatitis ampd is one of the many names for a raw painful irritated skin lesion that results in and worsens from a pet such as a dog or a cat constantly biting scratching chewing and licking an area of its skin that is irritated or itchy if it is covered by the dog s hair the hair holds in the moisture and further irritates it pyotraumatic dermatitis is an acute rapidly developing surface bacterial skin infection that occurs as a result of self inflicted trauma these lesions are created when the animal licks chews scratches and rubs a focal area of skin in response to an itchy pruritic painful stimulus as the lesion grows secondary infection from opportunistic bacteria can occur causing more discomfort and leading the pet to scratch and chew even more other names include wet eczema moist eczema summer sores acute moist alderman acute moist dermatitis pyo traumatic dermatitis or acute pyo traumatic dermatitis as the nickname summer sores suggests hot spots are more common in the summer however the ailment can occur at any time of the year many pets that develop them have allergies they are particularly common in pets with flea allergies however any sort of irritation to the skin can result in a hot spot
there are two very different definitions of hot start commonly used in aviation one for turbine based engines and one for reciprocating fuel injected engines
hot tub folliculitis also known as pseudomonas aeruginosa folliculitis is a common type of folliculitis a condition which causes inflammation of hair follicles this condition is caused by an infection of hair follicles due to the bacterium pseudomonas aeruginosa the bacterium is commonly found in hot tubs water slides and such places children are more prone to this because they usually stay in the water longer than adults hot tub folliculitis appears on the skin in the form of a rash roughly resembling chicken pox and then develops further to appear as a pimple hot tub folliculitis can be extremely painful and or itchy and left alone without scratching will go away much more quickly if the rash is aggravated it can stay worsen and spread lasting for months by that time it is much more difficult to treat the dots usually go away after about 7 to 10 days but the condition leaves a hyperpigmented lesion that goes away after a few months normally the rash does not need specific treatment and will go away on its own antibiotics may be prescribed in some cases if the rash continues to appear longer than the 7 to 10 day time period a physician should be consulted folliculitis that is not treated properly could worsen and cause abscesses
houndstooth hounds tooth check or hound s tooth and similar spellings also known as dogstooth dogtooth dog s tooth or pied de poule is a duotone textile pattern characterized by broken checks or abstract four pointed shapes often in black and white although other colours are used the classic houndstooth pattern is an example of a tessellation a smaller scale version of the pattern can be referred to as puppytooth
housing inequality is the difference in the quality of housing that exists within a given society it can have negative implications for the options available to an individual or family the term may apply regionally across a geographic space temporally between one generation and the next or culturally between groups of varying racial or social backgrounds housing inequality is directly related to concepts of racial inequality social inequality income inequality and wealth inequality in addition it is the result of a number of different factors including natural market forces housing discrimination and housing segregation housing inequality is also often linked to discussions of poverty because it can be seen as both a cause and an effect of poverty residential inequality is especially relevant to discussions of poverty when considering amartya sen ’ s definition of poverty as “ the deprivation of basic capabilities ”
howel – evans syndrome is an extremely rare condition involving thickening of the skin in the palms of the hands and the soles of the feet hyperkeratosis this familial disease is associated with a high lifetime risk of esophageal cancer for this reason it is sometimes known as tylosis with oesophageal cancer toc the condition is inherited in an autosomal dominant manner and it has been linked to a mutation in the rhbdf 2 gene it was first described in 1958
hoyeraal hreidarsson syndrome hhs is a very rare multisystem x linked recessive disorder characterized by excessively short telomeres and is considered a severe form of dyskeratosis congenita being an x linked disorder hhs primarily affects males patients with hhs typically present in early childhood with cerebellar hypoplasia immunodeficiency progressive bone marrow failure and intrauterine growth retardation the primary cause of death in hhs is bone marrow failure but mortality from cancer and pulmonary fibrosis is also significant
ho – kaufman – mcalister syndrome also known as the chen kung ho – kaufman – mcalister syndrome is a rare congenital malformation syndrome where infants are born with a cleft palate micrognathia wormian bones congenital heart disease dislocated hips bowed fibulae preaxial polydactyly of the feet abnormal skin patterns and most prominently missing tibia the etiology is unknown ho – kaufman – mcalister syndrome is named after chen kung ho r l kaufman and w h mcalister who first described the syndrome in 1975 at washington university in st louis it is considered a rare disease by the office of rare diseases ord of the national institutes of health nih
in statistics the huber loss is a loss function used in robust regression that is less sensitive to outliers in data than the squared error loss a variant for classification is also sometimes used
hughes stovin syndrome is a rare autoimmune disorder of unknown cause that is characterized by the combination of multiple pulmonary artery aneurysms and deep vein thrombosis it is named after the two british physicians john patterson hughes and peter george ingle stovin who first described it in 1959 it is a rare variant of behçet s disease which entails more general problems with the circulatory system most patients are young adult males between the age of 20 40 common clinical presentations include fever cough dyspnea and hemoptysis radiological features are similar to those of behçet s disease there is no satisfactory treatment for this disease
human behaviour genetics is a subfield of the field of behaviour genetics that studies the role of genetic and environmental influences on human behaviour classically human behavioural geneticists have studied the inheritance of behavioural traits the field was originally focused on testing whether genetic influences were important in human behavior e g do genes influence human behavior it has evolved to address more complex questions such as how important are genetic and or environmental influences on various human behavioral traits to what extent do the same genetic and or environmental influences impact the overlap between human behavioral traits how do genetic and or environmental influences on behavior change across development and what environmental factors moderate the importance of genetic effects on human behavior gene environment interaction the field is interdisciplinary and draws from genetics psychology and statistics most recently the field has moved into the area of statistical genetics with many behavioral geneticists also involved in efforts to identify the specific genes involved in human behavior and to understand how the effects associated with these genes changes across time and in conjunction with the environment
human cytomegalovirus is a species of the cytomegalovirus genus of viruses which in turn is a member of the viral family known as herpesviridae or herpesviruses it is typically abbreviated as hcmv or commonly but more ambiguously as cmv it is also known as human herpesvirus 5 hhv 5 within herpesviridae hcmv belongs to the betaherpesvirinae subfamily which also includes cytomegaloviruses from other mammals although they may be found throughout the body hcmv infections are frequently associated with the salivary glands hcmv infection is typically unnoticed in healthy people but can be life threatening for the immunocompromised such as hiv infected persons organ transplant recipients or newborn infants congenital cytomegalovirus infection can lead to significant morbidity and even death after infection hcmv remains latent within the body throughout life and can be reactivated at any time eventually it may cause mucoepidermoid carcinoma and possibly other malignancies such as prostate cancer hcmv is found throughout all geographic locations and socioeconomic groups and infects between 60 and 70 of adults in industrialized countries and almost 100 in emerging countries of all herpes viruses hcmv harbors the most genes dedicated to altering evading innate and adaptive immunity in the host and represents a lifelong burden of antigenic t cell surveillance and immune dysfunction commonly it is indicated by the presence of antibodies in the general population seroprevalence is age dependent 58 9 of individuals aged 6 and older are infected with cmv while 90 8 of individuals aged 80 and older are positive for hcmv hcmv is also the virus most frequently transmitted to a developing fetus hcmv infection is more widespread in developing countries and in communities with lower socioeconomic status and represents the most significant viral cause of birth defects in industrialized countries congenital hcmv is the leading infectious cause of deafness learning disabilities and intellectual disability in childrencmv also seems to have a large impact on immune parameters in later life and may contribute to increased morbidity and eventual mortality
human echolocation is the ability of humans to detect objects in their environment by sensing echoes from those objects by actively creating sounds – for example by tapping their canes lightly stomping their foot snapping their fingers or making clicking noises with their mouths – people trained to orient by echolocation can interpret the sound waves reflected by nearby objects accurately identifying their location and size this ability is used by some blind people for acoustic wayfinding or navigating within their environment using auditory rather than visual cues it is similar in principle to active sonar and to animal echolocation which is employed by bats dolphins and toothed whales to find prey
human granulocytic anaplasmosis hga is a tick borne infectious disease caused by anaplasma phagocytophilum an obligate intracellular bacterium that is typically transmitted to humans by ticks of the ixodes ricinus species complex including ixodes scapularis and ixodes pacificus in north america these ticks also transmit lyme disease and other tick borne diseases the bacteria infect white blood cells called neutrophils causing changes in gene expression that prolong the life of these otherwise short lived cells
hair color is the pigmentation of hair follicles due to two types of melanin eumelanin and pheomelanin generally if more eumelanin is present the color of the hair is darker if less eumelanin is present the hair is lighter the darker a person s natural hair color is the more individual hair follicles they have on their scalp levels of melanin can vary over time causing a person s hair color to change and it is possible to have hair follicles of more than one color on the same person particular hair colors are associated with ethnic groups gray or white hair is associated with age the fischer – saller scale named after eugen fischer and saller is used in physical anthropology and medicine to determine the shades of hair color the scale uses the following designations a very light blond b to e light blond f to l blond m to o dark blond p to t light brown to brown u to y dark brown black and roman numerals i to iv red and v to vi red blond
human herpesvirus 7 hhv 7 is one of nine known members of the herpesviridae family that infects humans hhv 7 is a member of betaherpesviridae a subfamily of the herpesviridae that also includes hhv 6 and cytomegalovirus hhv 5 or hcmv hhv 7 often acts together with hhv 6 and the viruses together are sometimes referred to by their genus roseolovirus hhv 7 was first isolated in 1990 from cd 4 t cells taken from peripheral blood lymphocytes
human monocytotropic ehrlichiosis hme is a form of ehrlichiosis associated with ehrlichia chaffeensis this bacteria is an obligate intracellular pathogen affecting monocytes and macrophages
human papillomavirus infection is an infection by human papillomavirus hpv most hpv infections cause no symptoms and resolve spontaneously in some they persist and result in warts or precancerous lesions the precancerous lesions increase the risk of cancer of the cervix vulva vagina penis anus mouth or throat nearly all cervical cancer is due to hpv with two types hpv 16 and hpv 18 accounting for 70 of cases between 60 and 90 of the other cancers are also linked to hpv hpv 6 and hpv 11 are common causes of genital warts and respiratory papillomatosis hpv infection is caused by a human papillomavirus a dna virus from the papillomavirus family of which over 150 types are known more than 40 types are transmitted through sexual contact and infect the anus and genitals risk factors for persistent hpv infections include early age of first sexual intercourse multiple partners smoking and poor immune function hpv is typically spread by sustained direct skin to skin contact with vaginal and anal sex being the most common methods occasionally it can spread from a mother to her baby during pregnancy it does not spread via common items like toilet seats people can become infected with more than one type of hpv hpv only affects humans hpv vaccines can prevent the most common types of infection to be effective they must be used before an infection occurs and are therefore recommended between the ages of nine and 13 cervical cancer screening such as with the papanicolaou test pap or looking at the cervix after using acetic acid can detect early cancer or abnormal cells that may develop into cancer this allows for early treatment which results in better outcomes screening has reduced both the number and deaths from cervical cancer in the developed world warts can be removed by freezing hpv is the most common sexually transmitted infection globally most people are infected at some point in their lives in 2012 about 528 000 new cases and 266 000 deaths occurred from cervical cancer worldwide around 85 of these occurred in the developing world in the united states about 27 000 cases of cancer due to hpv occur each year about 1 of sexually active adults have genital warts while cases of warts have been described since the time of ancient greece their viral nature was discovered in 1907
human resource management hrm or simply hr is the management of human resources it is a function in organizations designed to maximize employee performance in service of an employer s strategic objectives hr is primarily concerned with the management of people within organizations focusing on policies and on systems hr departments and units in organizations typically undertake a number of activities including employee benefits design employee recruitment training and development performance appraisal and rewarding e g managing pay and benefit systems hr also concerns itself with organizational change and industrial relations that is the balancing of organizational practices with requirements arising from collective bargaining and from governmental laws hr is a product of the human relations movement of the early 20 th century when researchers began documenting ways of creating business value through the strategic management of the workforce the function was initially dominated by transactional work such as payroll and benefits administration but due to globalization company consolidation technological advances and further research hr as of 2015 focuses on strategic initiatives like mergers and acquisitions talent management succession planning industrial and labor relations and diversity and inclusion human resources is a business field focused on maximizing employee productivity human resources professionals manage the human capital of an organization and focus on implementing policies and processes they can be specialists focusing in on recruiting training employee relations or benefits recruiting specialists are in charge of finding and hiring top talent training and development professionals ensure that employees are trained and have continuous development this is done through training programs performance evaluations and reward programs employee relations deals with concerns of employees when policies are broken such as harassment or discrimination someone in benefits develops compensation structures family leave programs discounts and other benefits that employees can get on the other side of the field are human resources generalists or business partners these human resources professionals could work in all areas or be labor relations representatives working with unionized employees in startup companies trained professionals may perform hr duties in larger companies an entire functional group is typically dedicated to the discipline with staff specializing in various hr tasks and functional leadership engaging in strategic decision making across the business to train practitioners for the profession institutions of higher education professional associations and companies themselves have established programs of study dedicated explicitly to the duties of the function academic and practitioner organizations likewise seek to engage and further the field of hr as evidenced by several field specific publications hr is also a field of research study that is popular within the fields of management and industrial organizational psychology with research articles appearing in a number of academic journals including those mentioned later in this article businesses are moving globally and forming more diverse teams it is the role of human resources to make sure that these teams can function and people are able to communicate cross culturally and across borders due to changes in business current topics in human resources are diversity and inclusion as well as using technology to advance employee engagement in the current global work environment most companies focus on lowering employee turnover and on retaining the talent and knowledge held by their workforce new hiring not only entails a high cost but also increases the risk of a newcomer not being able to replace the person who worked in a position before hr departments strive to offer benefits that will appeal to workers thus reducing the risk of losing corporate knowledge
human rights in armenia tend to be better than those in most former soviet republics and have drawn closer to acceptable standards especially economically still there are several considerable problems overall the country is classified partly free by freedom house which gives it a score of 46 falling two points below bangladesh and one point above honduras
human rights in austria are generally respected by the government however there were problems in some areas there were some reports of police abuse and use of unjustified force against prisoners anti semitic incidents including physical attacks name calling property damage and threatening letters telephone calls and internet postings occurred during the year there was some governmental and societal discrimination against fathers muslims and members of unrecognized religious groups particularly those considered sects there were incidents of neo national socialist activity rightwing extremism and xenophobia trafficking in women and children for prostitution and labor also remained a problem
human trafficking in brazil is an ongoing problem brazil is a source country for men women girls and boys subjected to human trafficking specifically forced prostitution within the country and abroad as well as a source country for men and boys in forced labor within the country in 2012 there was a soap opera made about human trafficking named salve jorge
human trafficking in europe is a regional manifestation of the wider practice of trade in humans for the purposes of various forms of coercive exploitation human trafficking has existed for centuries all over the world and follows from the earlier practice of slavery which differed from human trafficking in that it was legally recognized and accepted it has become an increasing concern for countries in europe since the fall of communism the transition to a market economy in some countries has led to both opportunity and a loss of security for citizens of these countries economic hardship and promises of prosperity have left many people vulnerable to trafficking within their countries and to destinations in other parts of europe and the world unique to the balkans are some of the situations that support trafficking such as organized crime and the recruitment strategies that perpetuate it while some generalizations can be made the countries within this region face different challenges and are at varying stages of compliance with the rules that govern trafficking in persons
according to the us department of state human trafficking in the netherlands is a problem which affects particularly women and girls who are forced to work in the sex industry in the year of 2009 there were 909 registered victims of human trafficking according to the us department of state the netherlands is primarily a source and destination country for men women and children subjected to trafficking in persons specifically forced prostitution and forced labor though to a lesser extent it is a transit country for such trafficking accordint to the us department of state the top five countries of origin for victims are the netherlands china nigeria hungary and sierra leone
human trypanosomiasis is a cutaneous condition caused by several species of trypanosomes with skin manifestations usually being observed in the earlier stages of the disease as evanescent erythema erythema multiforme and edema especially angioedema
viruses are a major cause of human waterborne and water related diseases waterborne diseases are caused by water that is contaminated by human and animal urine and feces that contain pathogenic microorganisms a subject can get infected through contact with or consumption of the contaminated water viruses affect all living organisms from single cellular plants bacteria and animal to the highest forms of plants and animals including human beings viruses can interact with their host through several methods and mechanisms some viruses can be host specific hiv and some can be less host specific influenza viruses different viruses can have different routes of transmission for example hiv is directly transferred by contaminated body fluids from an infected host into the tissue or bloodstream of a new host while influenza is airborne and transmitted through inhalation of contaminated air containing viral particles by a new host enteric viruses primarily infect the intestinal tract through ingestion of food and water contaminated with viruses of fecal origin some viruses can be transmitted through all three routes of transmission water virology started about half a century ago when scientists attempted to detect the polio virus in water samples since then other pathogenic viruses that are responsible for gastroenteritis hepatitis and many other virus strains have replaced enteroviruses as the main aim for detection in the water environment
humanistic economics is a distinct pattern of economic thought with old historical roots that have been more recently invigorated by e f schumacher s small is beautiful economics as if people mattered 1973 proponents argue for persons first economic theories as opposed to mainstream economic theories which are understood as often emphasizing financial gain over human well being in particular the overly abstract human image implicit in mainstream economics is critically analyzed and instead it attempts a rethinking of economic principles policies and institutions based on a richer and more balanced view of human nature according to schumacher call a thing immoral or ugly soul destroying or a degradation of man a peril to the peace of the world or to the well being of future generations as long as you have not shown it to be uneconomic you have not really questioned its right to exist grow and prosper
the hume fracture is an injury of the elbow comprising a fracture of the olecranon with an associated anterior dislocation of the radial head which occurs in children it was originally described as an undisplaced olecranon fracture but more recently includes displaced fractures and can be considered a variant of the monteggia fracture the injury was described in 1957 by a c hume of the orthopaedic surgery department of st bartholomew s hospital rochester
a humerus fracture is a bone fracture of the bone of the upper arm the humerus fractures of the humerus may be classified by the location of the fracture and divided into fractures of the proximal region which is near the shoulder the middle region which is the shaft of the humerus and the distal region which is near the elbow these locations can further be divided based on the extent of the fracture and the specific areas of each of the three regions affected humerus fractures usually occur after physical trauma falls excess physical stress or pathological conditions falls are the most common cause of proximal and shaft fractures and those who experience a fracture from a fall usually have an underlying risk factor for bone fracture distal fractures occur most frequently in children who experience physical trauma to the elbow area symptoms of fracture are pain swelling and discoloration of the skin at the site of the fracture bruising appears a few days after the fracture the neurovascular bundle of the arm may be affected in severe cases which will cause loss of nerve function and diminished blood supply beneath the fracture proximal and distal fractures will often cause a loss of shoulder or elbow function displaced shaft and distal fractures may cause deformity and such shaft fractures will often shorten the length of the upper arm most humerus fractures are nondisplaced and will heal within a few weeks if the arm is immobilized severe displaced humerus fractures and complications often require surgical intervention in most cases normal function to the arm returns after the fracture is healed in severe cases however function of the arm may be diminished after recovery
humidity is the amount of water vapor in the air water vapor is the gaseous state of water and is invisible humidity indicates the likelihood of precipitation dew or fog higher humidity reduces the effectiveness of sweating in cooling the body by reducing the rate of evaporation of moisture from the skin this effect is calculated in a heat index table or humidex the amount of water vapor that is needed to achieve saturation increases as the temperature increases as the temperature of a parcel of air becomes lower it will eventually reach the point of saturation without adding or losing water mass the differences in the amount of water vapor in a parcel of air can be quite large for example a parcel of air that is near saturation may contain 28 grams of water per cubic meter of air at 30 ° c but only 8 grams of water per cubic meter of air at 8 ° c there are three main measurements of humidity absolute relative and specific absolute humidity is the water content of air at a given temperature expressed in gram per cubic meter relative humidity expressed as a percent measures the current absolute humidity relative to the maximum highest point for that temperature specific humidity is a ratio of the water vapor content of the mixture to the total air content on a mass basis
humoral immune deficiencies are conditions which cause impairment of humoral immunity which can lead to immunodeficiency it can be mediated by insufficient number or function of b cells the plasma cells they differentiate into with these two potentially being caused by b cell lymphocytopenia or the antibody secreted by the plasma cells they are associated with increased vulnerability to infection but can be difficult to detect or asymptomatic in the absence of infection they can be associated with increased risk of gastric cancer
hunan hand syndrome also known as chili burn is a cutaneous condition and commonly among those who remove the skins from large batches of roasted chili peppers
the hundred dollar hundred digit challenge problems are 10 problems in numerical mathematics published in 2002 by nick trefethen a 100 prize was offered to whoever produced the most accurate solutions measured up to 10 significant digits the deadline for the contest was may 20 2002 in the end 20 teams solved all of the problems perfectly within the required precision and an anonymous donor aided in producing the required prize monies the challenge and its solutions were described in detail in the book folkmar bornemann dirk laurie stan wagon et al
the hundredth monkey effect is a hypothetical phenomenon in which a new behavior or idea is claimed to spread rapidly by unexplained means from one group to all related groups once a critical number of members of one group exhibit the new behavior or acknowledge the new idea one of the primary factors in the promulgation of the story is that many authors quote secondary tertiary or post tertiary sources which have themselves misrepresented the original observations
in politics humanitarian aid and social science hunger is a condition in which a person for a sustained period is unable to eat sufficient food to meet basic nutritional needs throughout history portions of the world s population have often experienced sustained periods of hunger in many cases this resulted from food supply disruptions caused by war plagues or adverse weather for the first few decades after world war ii technological progress and enhanced political cooperation suggested it might be possible to substantially reduce the number of people suffering from hunger while progress was uneven by 2000 the threat of extreme hunger subsided for many of the world s people according to the wfp some statistics are that some 795 million people in the world do not have enough food to lead a healthy active life that s about one in nine people on earth the vast majority of the world s hungry people live in developing countries where 12 9 percent of the population is undernourished until 2006 the average international price of food had been largely stable for several decades in the closing months of 2006 however prices began to rise rapidly by 2008 rice had tripled in price in some regions and this severely affected developing countries food prices fell in early 2009 but rose to another record high in 2011 and have since decreased slightly the 2008 worldwide financial crisis further increased the number of people suffering from hunger including dramatic increases even in advanced economies such as great britain the eurozone and the united states the millennium development goals included a commitment to a further 50 reduction in the proportion of the world s population who suffer from extreme hunger by 2015 as of 2012 this target appeared difficult to achieve due in part to persistent inflation in food prices however in late 2012 the un s food and agriculture organization fao stated it is still possible to hit the target with sufficient effort in 2013 the fao estimated that 842 million people are undernourished 12 of the global population malnutrition is a cause of death for more than 3 1 million children under 5 every year unicef estimates 300 million children go to bed hungry each night and that 8000 children under the age of 5 are estimated to die of malnutrition every day
the hunsdiecker reaction also called the borodin reaction after alexander borodin is the organic reaction of silver salts of carboxylic acids with halogens to give organic halides it is an example of a halogenation reaction the reaction is named after heinz hunsdiecker and cläre hunsdiecker but was first noted by borodin in 1861 when he prepared methyl bromide from silver acetate the hunsdiecker reaction several reviews have been published mercuric oxide will also effect this transformation
the hunter valley cannabis infestation was an infestation of the marijuana plant cannabis sativa in the hunter valley in new south wales australia at its peak the infestation covered about 30 square kilometres 12 sq mi it took nine years for the new south wales government to eradicate it
hunter syndrome or mucopolysaccharidosis ii mps ii is a lysosomal storage disease caused by a deficient or absent enzyme iduronate 2 sulfatase i 2 s the accumulated substrates in hunter syndrome are heparan sulfate and dermatan sulfate the syndrome has x linked recessive inheritance
huntington s disease hd also known as huntington s chorea is an inherited disorder that results in death of brain cells the earliest symptoms are often subtle problems with mood or mental abilities a general lack of coordination and an unsteady gait often follow as the disease advances uncoordinated jerky body movements become more apparent physical abilities gradually worsen until coordinated movement becomes difficult and the person is unable to talk mental abilities generally decline into dementia the specific symptoms vary somewhat between people symptoms usually begin between 30 and 50 years of age but can start at any age the disease may develop earlier in life in each successive generation about 8 of cases start before the age of 20 years and typically present with symptoms more similar to parkinson s disease people with hd often underestimate the degree of their problems hd is typically inherited from a person s parents with 10 of cases due to a new mutation the disease is caused by an autosomal dominant mutation in either of an individual s two copies of a gene called huntingtin this means a child of an affected person typically has a 50 chance of inheriting the disease the huntingtin gene provides the genetic information for a protein that is also called huntingtin expansion of cag cytosine adenine guanine triplet repeats in the gene coding for the huntingtin protein results in an abnormal protein which gradually damages cells in the brain through mechanisms that are not fully understood diagnosis is by genetic testing which can occur at any point in time regardless of whether or not symptoms are present this fact raises several ethical debates the age at which an individual is considered mature enough to choose testing whether parents have the right to have their children tested and managing confidentiality and disclosure of test results there is no cure for hd full time care is required in the later stages of the disease treatments can relieve some symptoms and in some improve quality of life the best evidence for treatment of the movement problems is with tetrabenazine hd affects about 4 to 15 in 100 000 people of european descent it is rare among japanese and occurs at an unknown rate in africa the disease affects men and women equally complications such as pneumonia heart disease and physical injury from falls reduce life expectancy suicide is the cause of death in about 9 of cases death typically occurs fifteen to twenty years from when the disease was first detected the first likely description of the disease was in 1841 by charles oscar waters the condition was described in further detail in 1872 by george huntington after whom it is named the genetic basis was discovered in 1993 by an international collaborative effort led by the hereditary disease foundation research and support organizations began forming in the late 1960 s to increase public awareness to provide support for individuals and their families and to promote research current research directions include determining the exact mechanism of the disease improving animal models to aid with research testing of medications to treat symptoms or slow the progression of the disease and studying procedures such as stem cell therapy with the goal of repairing damage caused by the disease
the huntington s disease like syndromes often abbreviated as hd like or hdl syndromes are a family of inherited neurodegenerative diseases that closely resemble huntington s disease hd in that they typically produce a combination of chorea cognitive decline or dementia and behavioural or psychiatric problems
hurler syndrome also known as mucopolysaccharidosis type i mps i hurler s disease also gargoylism is a genetic disorder that results in the buildup of glycosaminoglycans formerly known as mucopolysaccharides due to a deficiency of alpha l iduronidase an enzyme responsible for the degradation of mucopolysaccharides in lysosomes without this enzyme a buildup of heparan sulfate and dermatan sulfate occurs in the body symptoms appear during childhood and early death can occur due to organ damage mps i is divided into three subtypes based on severity of symptoms all three types result from an absence of or insufficient levels of the enzyme α l iduronidase mps i h or hurler syndrome is the most severe of the mps i subtypes the other two types are mps i s or scheie syndrome and mps i h s or hurler scheie syndrome hurler syndrome is often classified as a lysosomal storage disease and is clinically related to hunter syndrome hunter syndrome is x linked while hurler syndrome is autosomal recessive it is named for gertrud hurler 1889 – 1965 a german pediatrician
hurler – scheie syndrome also known as mucopolysaccharidosis type i h s is a cutaneous condition also characterized by mild mental retardation and corneal clouding
a hürthle cell is a cell in the thyroid that is often associated with hashimoto s thyroiditis as well as follicular thyroid cancer hürthle cell cancer is considered a variant of follicular thyroid cancer this version is a relatively rare form of differentiated thyroid cancer accounting for only 3 10 of all differentiated thyroid cancers oncocytes in the thyroid are often called hürthle cells although the terms oncocyte oxyphilic cell and hürthle cell are used interchangeably hürthle cell is used only to indicate cells of thyroid follicular origin
in mathematics the hutchinson metric is a function which measures the discrepancy between two images for use in fractal image processing and can also be applied to describe the similarity between dna sequences expressed as real or complex genomic signals
huzzas also referred to as huzzawouie huzzas is the name of a surf break off gracetown western australia it is in proximity to a number of other surf breaks that are located near to cowaramup bay and gracetown
hwabyeong or hwabyung is a korean somatization disorder a mental illness which arises when people are unable to confront their anger as a result of conditions which they perceive to be unfair hwabyung is loosely used as the name of the disease as it is actually more of a name regarding the cause hwabyung is known as a culture bound syndrome the word hwabyung is composed of hwa meaning fire angry and byung meaning syndrome or illness in south korea it is also called ulhwabyeong 鬱火病 depression anger illness in a survey 4 1 of the general population in a rural area in korea were reported as having hwabyung another survey shows that about 35 of korean employees begin to suffer from this disease at some point
hyalinizing clear cell carcinoma abbreviated hccc is a rare malignant salivary gland tumour with a good prognosis that is usually found on the tongue or palate
hyalinizing trabecular adenoma or hyalinizing trabecular adenoma is a subtype of thyroid adenoma
hyaluronidase deficiency also known as mucopolysaccharidosis type ix is a condition caused by mutations in hyal 1 and characterized by multiple soft tissue masses
hybrid oncocytoma chromophobe renal cell carcinoma is rare subtype of renal cell carcinoma it arises from intercalated cells of cortical collecting ducts of the kidney it is associated with extreme hypodiploidy with multiple losses of entire chromosomes 1 2 6 10 13 17 21 and y
hydra viridissima also known as hydra viridis and chlorohydra viridissima or the green hydra is a species of freshwater hydroid polyp in the genus hydra found widely dispersed in the northern temperate zone it is a common organism found in still waters from early spring to late autumn the characteristic green colour comes from cells of the unicellular alga chlorella within the cells of the gastrodermis because of this h viridissima are generally less predacious than aposymbiotic hydra species it is most commonly found attached to the stems of water plants and the undersides of leaves including duckweed when disturbed it retracts to a small green blob which is easily overlooked gently sweeping through a clean weedy pond and allowing the collected water and leaves to stand in a jar will often reveal h viridissima emerging after only a few minutes h viridissima in captivity will tend to congregate towards the light when in feeding mode the extended tentacles are generally only as long as or shorter than the body it lives in water and resembles a fine delicate seaweed h viridissima h viridissima
hydranencephaly or hydrancephaly is a condition in which the brain s cerebral hemispheres are absent to varying degrees and the remaining cranial cavity is filled with cerebrospinal fluid hydranencephaly or hydrancephaly is a type of cephalic disorder these disorders are congenital conditions that derive from either damage to or abnormal development of the fetal nervous system in the earliest stages of development in utero cephalic is the medical term for “ head ” or “ head end of body ” these conditions do not have any definitive identifiable cause factor instead generally attributed to a variety of hereditary or genetic conditions but also by environmental factors such as maternal infection pharmaceutical intake or even exposure to high levels of radiation this should not be confused with hydrocephalus which is an accumulation of excess cerebrospinal fluid in the ventricles of the brain in hemihydranencephaly only half of the cranial cavity is filled with fluid
hydration energy also hydration enthalpy is the amount of energy released when one mole of ions undergo hydration which is a special case of solvation it is a special case of dissolution energy with the solvent being water for example upon dissolving a salt in water the outermost ions those at the edge of the lattice move away from the lattice and become covered with the neighboring water molecules if the hydration energy is equal to or greater than the lattice energy then the salt is water soluble in salts for which the hydration energy is higher than the lattice energy solvation occurs with a release of energy in the form of heat for instance cacl 2 anhydrous calcium chloride heats the water when dissolving however the hexahydrate cacl 2 · 6 h 2 o cools the water upon dissolution the latter happens because the hydration energy does not completely over come the lattice energy and the remainder has to be taken from the water in order to compensate the energy loss
in chemistry a hydration reaction is a chemical reaction in which a substance combines with water in organic chemistry water is added to an unsaturated substrate which is usually an alkene or an alkyne this type of reaction is employed industrially to produce ethanol isopropanol and 2 butanol
a hydraulic jump is a phenomenon in the science of hydraulics which is frequently observed in open channel flow such as rivers and spillways when liquid at high velocity discharges into a zone of lower velocity a rather abrupt rise occurs in the liquid surface the rapidly flowing liquid is abruptly slowed and increases in height converting some of the flow s initial kinetic energy into an increase in potential energy with some energy irreversibly lost through turbulence to heat in an open channel flow this manifests as the fast flow rapidly slowing and piling up on top of itself similar to how a shockwave forms the phenomenon is dependent upon the initial fluid speed if the initial speed of the fluid is below the critical speed then no jump is possible for initial flow speeds which are not significantly above the critical speed the transition appears as an undulating wave as the initial flow speed increases further the transition becomes more abrupt until at high enough speeds the transition front will break and curl back upon itself when this happens the jump can be accompanied by violent turbulence eddying air entrainment and surface undulations or waves there are two main manifestations of hydraulic jumps and historically different terminology has been used for each however the mechanisms behind them are similar because they are simply variations of each other seen from different frames of reference and so the physics and analysis techniques can be used for both types the different manifestations are the stationary hydraulic jump – rapidly flowing water transitions in a stationary jump to slowly moving water as shown in figures 1 and 2 the tidal bore – a wall or undulating wave of water moves upstream against water flowing downstream as shown in figures 3 and 4 if considered from a frame of reference which moves with the wave front you can see that this case is physically similar to a stationary jump a related case is a cascade – a wall or undulating wave of water moves downstream overtaking a shallower downstream flow of water as shown in figure 5 if considered from a frame of reference which moves with the wave front this is amenable to the same analysis as a stationary jump these phenomena are addressed in an extensive literature from a number of technical viewpoints
hydraulic jump in a rectangular channel also known as classical jump is a natural phenomenon that occurs whenever flow changes from supercritical to subcritical flow in this transition the water surface rises abruptly surface rollers are formed intense mixing occurs air is entrained and often a large amount of energy is dissipated in other words a hydraulic jump happens when a higher velocity v 1 supercritical flow upstream is met by a subcritical downstream flow with a decreased velocity v 2 and sufficient depth numeric models created using the standard step method or hec ras are used to track supercritical and subcritical flows to determine where in a specific reach a hydraulic jump will form there are common hydraulic jumps that occur in everyday situations such as during the use of a household sink there are also man made hydraulic jumps created by devices like weirs or sluice gates in general a hydraulic jump may be used to dissipate energy to mix chemicals or to act as an aeration device to produce equations describing the jump since there is an unknown energy loss there is a need to apply conservation of momentum to develop this equation a general situation in which there may or may not be an energy loss between upstream and downstream and there may or may not be some obstacle on which there is a drag force pf is considered however for a simple or classic hydraulic jump the force per unit width pf equals 0 from there the momentum equation and the conjugate depths equation can be derived
hydrazone iodination is an organic reaction in which a hydrazone is converted into a vinyl iodide by reaction of iodine and a non nucleophilic base such as dbu first published by d h r barton in 1962 the reaction is sometimes referred to as the barton reaction although there are many different barton reactions or more descriptively as the barton vinyl iodine procedure the reaction has earlier roots with the 1911 discovery by wieland and roseeu that the reaction of hydrazones with iodine alone without base results in the azine dimer structure 2 in scheme 1 iodination of hydrazones in the original barton publication the reaction was optimized by using a strong guanidine base the inverse addition of the hydrazone to an iodine solution and by exclusion of water barton vinyl iodide synthesis when iodine as an electrophile is replaced by aromatic selenyl bromides the corresponding vinyl selenides are obtained vinyl selenide synthesis
hydroa vacciniforme hv is a very rare chronic photodermatitis type skin condition with usual onset in childhood it was first described in 1862 by bazin it is sometimes called bazin s hydroa vacciniforme a study published in scotland in 2000 reviewed the cases of 17 patients and estimated a prevalence of 0 34 cases per 100 000 population in this study they reported an average age of onset of 7 9 years frequently the rash first appeared in the spring or summer months and involved sun exposed skin the rash starts as a vesicular eruption later becoming umbilicated and resulted in vacciniform scarring it is most frequently found on the nose cheeks ears dorsum of the hand and arms places that are most exposed to light
hydroacylation is a type of organic reaction in which an aldehyde is added over an alkene or alkyne bond the reaction product is a ketone the reaction requires a metal catalyst often rhodium it is almost invariably practice as an intramolecular reaction with an alkyne in place of alkenes the reaction product is an α β unsaturated ketone hydroacylation general the reaction was discovered as part of a synthetic route to certain prostanoids the reaction required tin tetrachloride and a stoichiometric amount of wilkinson s catalyst an equal amount of a cyclopropane was formed as the result of decarbonylation hydroacylation sakai 1972 the first catalytic application was reported by miller in 1976 in their reaction treatment of 4 pentenal with wilkinson s catalyst gave cyclopentanone in this reaction the solvent was saturated with ethylene cyclopentanone synthesis miller another suitable catalyst is the salt rh dppe 2 clo 4
hydroalkoxylation is a chemical reaction that combines alcohols with alkenes or alkynes the process affords ethers the reaction converts alkenes to dialkyl or aryl alkyl ethers r oh rch ch 2 → r och r ch 3 similarly akynes are converted to vinyl ethers r oh rc ≡ ch → r oc r ch 2 as shown the reaction follows the markovnikov rule the process exhibits good atom economy in the sense that no byproducts are produced the reaction is catalyzed by bases and also by transition metal complexes usually symmetrical ethers are prepared by dehydration of alcohols and unsymmetrical ethers by the williamson ether synthesis from alkyl halides and alkali metal alkoxides
in organic chemistry the hydroboration – oxidation reaction is a two step organic reaction that converts an alkene into a neutral alcohol by the net addition of water across the double bond the hydrogen and hydroxyl group are added in a syn addition leading to cis stereochemistry hydroboration – oxidation is an anti markovnikov reaction with the hydroxyl group attaching to the less substituted carbon the reaction was first reported by herbert c brown in the late 1950 s and it was recognized in his receiving the nobel prize in chemistry in 1979 the general form of the reaction is as follows tetrahydrofuran thf is the archetypal solvent used for hydroborations
a hydrocarbon keratosis also known as pitch keratosis tar keratosis and tar wart is a precancerous keratotic skin lesion that occurs in people who have been occupationally exposed to polycyclic aromatic hydrocarbons
a hydrocele br english hydrocoele denotes a pathological accumulation of serous fluid in a body cavity a hydrocele testis the accumulation of fluids around a testicle is fairly common it is often caused by fluid secreted from a remnant piece of peritoneum wrapped around the testicle called the tunica vaginalis provided there is no hernia present hydrocoeles below the age of 1 year usually resolve spontaneously primary hydrocoeles may develop in adulthood particularly in the elderly and in hot countries by slow accumulation of serous fluid presumably caused by impaired reabsorption which appears to be the explanation for most primary hydroceles although the reason remains obscure a hydrocele can also be the result of a plugged inguinal lymphatic system caused by repeated chronic infection of wuchereria bancrofti or brugia malayi two mosquito borne parasites of africa and southeast asia respectively as such the condition would be a part of more diffuse sequelae commonly referred to as elephantiasis which also affects the lymphatic system in other parts of the body
a hydrocele testis is an accumulation of clear fluid in the tunica vaginalis the most internal of membranes containing a testicle a primary hydrocele causes a painless enlargement in the scrotum on the affected side and is thought to be due to the defective absorption of fluid secreted between the two layers of the tunica vaginalis investing membrane a secondary hydrocele is secondary to either inflammation or a neoplasm in the testis a hydrocele usually occurs on one side but can also affect both sides the accumulation can be a marker of physical trauma infection tumor or varicocele surgery but the cause is generally unknown indirect inguinal hernia indicates increased risk of hydrocele hydrocele is normally seen in infant boys as enlarged scrotum in infant girls it appears as enlarged labia however hydrocele is more common in boys than girls
hydrocephalus is a condition in which there is an abnormal accumulation of cerebrospinal fluid csf within the brain this typically causes increased pressure inside the skull older people may have headaches double vision poor balance urinary incontinence personality changes or mental impairment in babies there may be a rapid increase in head size other symptoms may include vomiting sleepiness seizures and downward pointing of the eyes hydrocephalus can occur due to birth defects or be acquired later in life associated birth defects include neural tube defects and those that result in aqueductal stenosis other causes include meningitis brain tumors traumatic brain injury intraventricular hemorrhage and subarachnoid hemorrhage there are four types of hydrocephalus communicating non communicating ex vacuo and normal pressure diagnosis is typically by examination and medical imaging hydrocephalus is typically treated by the surgical placement of a shunt system a procedure called a third ventriculostomy may be an option in a few people complications from shunts may include overdrainage underdrainage mechanical failure infection or obstruction this may require replacement outcomes are variable however many live normal lives without treatment death may occur about one to two per 1 000 newborns have hydrocephalus rates in the developing world may be more normal pressure hydrocephalus is estimated to affect about 5 per 100 000 people with rates increasing with age description of hydrocephalus by hippocrates date back more than 2000 years the word hydrocephalus is from from greek hydro meaning water and kephalos meaning head
hydrodealkylation is a chemical reaction that often involves reacting an aromatic hydrocarbon such as toluene in the presence of hydrogen gas to form a simpler aromatic hydrocarbon devoid of functional groups an example is the conversion of 1 2 4 trimethylbenzene to xylene this chemical process usually occurs at high temperature at high pressure or in the presence of a catalyst these are predominantly transition metals such as chromium or molybdenum
hydrodefluorination hdf is a type of organic reaction in which in a substrate a carbon – fluorine bond is replaced by a carbon – hydrogen bond the topic is of some interest to scientific research in one general strategy for the synthesis of fluorinated compounds with a specific substitution pattern the substrate is a cheaply available perfluorinated hydrocarbon an example is the conversion of hexafluorobenzene c 6 f 6 to pentafluorobenzene c 6 f 5 h by certain zirconocene hydrido complexes in this type of reaction the thermodynamic driving force is the formation of a metal fluorine bond that can offset the cleavage of the very stable c f bond other substrates that have been investigated are fluorinated alkenes another reaction type is oxidative addition of a metal into a c f bond followed by a reductive elimination step in presence of a hydrogen source for example perfluoronated pyridine reacts with bis cyclooctadiene nickel 0 and triethylphosphine to the oxidative addition product and then with hcl to the ortho hydrodefluorinated product in reductive hydrodefluorination the fluorocarbon is reduced in a series of single electron transfer steps through the radical anion the radical and the anion with ultimate loss of a fluorine anion an example is the conversion of pentafluorobenzoic acid to 3 4 5 tetrafluorobenzoic acid in a reaction of zinc dust in aqueous ammonia specific systems that have been reported for fluoroalkyl group hdf are triethylsilane carborane acid and nicl 2 pcy 3 2 lial o t bu 3 h
hydrogen atom abstraction or hydrogen atom transfer hat in chemistry is any chemical reaction in which a hydrogen free radical is abstracted from a substrate according to the general equation x h y x h y examples of hat reactions are oxidative reactions in general hydrocarbon combustion and reactions involving cytochrome p 450 containing an iron v oxo unit the abstractor is usually a radical species itself an example of a closed shell abstractor is chromyl chloride hat can take place through proton coupled electron transfer
a hydrogen odorant in any form is a minute amount of odorant such as ethyl isobutyrate with a rotting cabbage like smell that is added to the otherwise colorless and almost odorless hydrogen gas so that leaks can be detected before a fire or explosion occurs odorants are considered non toxic in the extremely low concentrations occurring in hydrogen gas delivered to the end user the approach is not new for the same safety reasons the odorant tert butyl mercaptan is used in natural gas
hydrogenation – to treat with hydrogen – is a chemical reaction between molecular hydrogen h 2 and another compound or element usually in the presence of a catalyst such as nickel palladium or platinum the process is commonly employed to reduce or saturate organic compounds hydrogenation typically constitutes the addition of pairs of hydrogen atoms to a molecule often an alkene catalysts are required for the reaction to be usable non catalytic hydrogenation takes place only at very high temperatures hydrogenation reduces double and triple bonds in hydrocarbons
hydrogenolysis is a chemical reaction whereby a carbon – carbon or carbon – heteroatom single bond is cleaved or undergoes lysis breakdown by hydrogen the heteroatom may vary but it usually is oxygen nitrogen or sulfur a related reaction is hydrogenation where hydrogen is added to the molecule without cleaving bonds usually hydrogenolysis is conducted catalytically using hydrogen gas
hydrogen – deuterium exchange also called h – d or h d exchange is a chemical reaction in which a covalently bonded hydrogen atom is replaced by a deuterium atom or vice versa it can be applied most easily to exchangeable protons and deuterons where such a transformation occurs in the presence of a suitable deuterium source without any catalyst the use of acid base or metal catalysts coupled with conditions of increased temperature and pressure can facilitate the exchange of non exchangeable hydrogen atoms so long as the substrate is robust to the conditions and reagents employed this often results in perdeuteration hydrogen deuterium exchange of all non exchangeable hydrogen atoms in a molecule an example of exchangeable protons which are commonly examined in this way are the protons of the amides in the backbone of a protein the method gives information about the solvent accessibility of various parts of the molecule and thus the tertiary structure of the protein hydrogen exchange was first shown and explored by kaj ulrik linderstrøm lang
hydroid dermatitis is a cutaneous condition that occurs after contact with the small marine hydroid halecium
hydrolethalus syndrome less commonly referred to as salonen herva norio syndrome is a rare genetic disorder that causes improper fetal development resulting in birth defects and often stillbirth it is associated with hyls 1 mutations
hydrolock a shorthand notation for hydrostatic lock is an abnormal condition of any device which is designed to compress a gas by mechanically restraining it most commonly the reciprocating internal combustion engine the case this article refers to unless otherwise noted hydrolock occurs when a volume of liquid greater than the volume of the cylinder at its minimum end of the piston s stroke enters the cylinder since liquids are nearly incompressible the piston cannot complete its travel either the engine must stop rotating or a mechanical failure must occur
hydrometalation hydrometallation is a type of chemical reaction in organometallic chemistry in which a chemical compound with a hydrogen to metal bond m h metal hydride adds to compounds with an unsaturated bond like an alkene rc cr forming a new compound with a carbon to metal bond rhc crm the metal is less electronegative than hydrogen the reverse reaction is beta hydride elimination the reaction is structurally related to carbometalation when the substrate is an alkyne the reaction product is a vinylorganometallic hydrometalation of an alkene examples are hydroboration hydroalumination hydrosilylation and hydrozirconation
hydronephrosis — literally water inside the kidney — refers to distension and dilation of the renal pelvis and calyces usually caused by obstruction of the free flow of urine from the kidney untreated it leads to progressive atrophy of the kidney one or both kidneys may be affected in cases of hydroureteronephrosis there is distention of both the ureter and the renal pelvis and calices
hydrophobic mismatch is the difference between the hydrophobic length of the integral proteins and the hydrophobic thickness of the membrane they span under the consideration of energy requirement in order to avoid unfavorable exposure of hydrophobic surfaces to a hydrophilic environment the hydrophobic length of the integral proteins is supposed to be approximately equal to the hydrophobic bilayer thickness
hydrophthalmos is a congenital form of glaucoma
hydropneumothorax is defined as the presence of both air and fluid within the pleural space surrounding the lung an upright chest x ray will show air fluid levels the horizontal fluid level is usually well defined and extends across the whole length of hemithorax
hydrops ectopic calcification moth eaten skeletal dysplasia is a defect in cholesterol biosynthesis it is also known as greenberg dysplasia greenberg characterized the condition in 1988 it has been associated with the lamin b receptor
hydrops fetalis is a condition in the fetus characterized by an accumulation of fluid or edema in at least two fetal compartments by comparison hydrops allantois or hydrops amnion is an accumulation of excessive fluid in the allantoic or amniotic space respectively
a hydrosalpinx is a distally blocked fallopian tube filled with serous or clear fluid the blocked tube may become substantially distended giving the tube a characteristic sausage like or retort like shape the condition is often bilateral and the affected tubes may reach several centimeters in diameter the blocked tubes cause infertility a fallopian tube filled with blood is a hematosalpinx and with pus a pyosalpinx hydrosalpinx is a composite of the greek words ὕδωρ hydōr water and σάλπιγξ sálpinx trumpet its plural is hydrosalpinges
hydrothorax is a type of pleural effusion in which serous fluid accumulates in the pleural cavity this condition is most likely to develop secondary to congestive heart failure but may rarely develop in patients with cirrhosis or ascites hepatic hydrothorax is often difficult to manage in end stage liver failure and often fails to respond to therapy in similar pleural effusions the fluid is blood in hemothorax as in major chest injuries pus in pyothorax resulting from chest infections and lymph in chylothorax resulting from rupture of the thoracic duct
hydroxyethyl starch induced pruritus is an intense itching lasting for as long as one year occurring following hydroxyethyl starch intravenous infusion for vascular insufficiency there is no treatment for the itch an updated clinical review on storage in different tissues describes a pattern of storage in the reticuloendothelial system and also the skin wiedermann differential storage described via immunelectronical microscopy see ständer 2001 below
hydroxyurea dermopathy is caused by chronic use of hydroxyurea for chronic myelogenous leukemia thrombocytosis or psoriasis and presents with skin lesions characteristic of dermatomyositis
hyena butter is a secretion from the anal gland of hyenas used to mark territory and to identify individuals by odor the gooey substance is spread onto objects within the territory of the hyena by rubbing their posterior against the object they mark african legends state that witches would ride hyenas and use a gourd full of hyena butter as fuel for the torches they carried through the night
hygroscopy is the phenomenon of attracting and holding water molecules from the surrounding usually at normal or room temperature environment this is achieved through either absorption or adsorption with the absorbing or adsorbing substance becoming physically changed somewhat this could be by an increase in volume boiling point viscosity or other physical characteristic and properties of the substance as water molecules can become suspended between the substance s molecules in the process hygroscopic substances include cellulose fibers such as cotton and paper sugar caramel honey glycerol ethanol methanol sulfuric acid many fertilizer chemicals many salts including table salt and a wide variety of other substances zinc chloride and calcium chloride as well as potassium hydroxide and sodium hydroxide and many different salts are so hygroscopic that they readily dissolve in the water they absorb this property is called deliquescence not only is sulfuric acid hygroscopic in concentrated form but its solutions are hygroscopic down to concentrations of 10 vol or below a hygroscopic material will tend to become damp and cakey when exposed to moist air such as the salt inside salt shakers during humid weather because of their affinity for atmospheric moisture hygroscopic materials might require storage in sealed containers when added to foods or other materials for the express purpose of maintaining moisture content such substances are known as humectants materials and compounds exhibit different hygroscopic properties and this difference can lead to detrimental effects such as stress concentration in composite materials the volume of a particular material or compound is affected by ambient moisture and may be considered its coefficient of hygroscopic expansion che also referred to as cme or coefficient of moisture expansion or coefficient of hygroscopic contraction chc — the difference between the two terms being a difference in sign convention differences in hygroscopy can be observed in plastic laminated paperback book covers — often in a suddenly moist environment the book cover will curl away from the rest of the book the unlaminated side of the cover absorbs more moisture than the laminated side and increases in area causing a stress that curls the cover toward the laminated side this is similar to the function of a thermostat s bi metallic strip inexpensive dial type hygrometers make use of this principle using a coiled strip deliquescence the process by which a substance absorbs moisture from the atmosphere until it dissolves in the absorbed water and forms a solution deliquescence occurs when the vapour pressure of the solution that is formed is less than the partial pressure of water vapour in the air while some similar forces are at work here it is different from capillary attraction a process where glass or other solid substances attract water but are not changed in the process e g water molecules do not become suspended between the glass molecules the similar sounding but unrelated word hydroscopic is sometimes used in error for hygroscopic a hydroscope is an optical device used for making observations deep under water
in computer science and in particular functional programming a hylomorphism is a recursive function corresponding to the composition of an anamorphism which first builds a set of results also known as unfolding followed by a catamorphism which then folds these results into a final return value fusion of these two recursive computations into a single recursive pattern then avoids building the intermediate data structure this is an example of deforestation a program optimization strategy a related type of function is a metamorphism which is a catamorphism followed by an anamorphism
hylophobia also known as xylophobia ylophobia and dendrophobia is a psychological disorder defined by an irrational fear of wood forest or trees it is a type of specific phobia
hymenolepiasis is infestation by one of two species of tapeworm hymenolepis nana or h diminuta alternative names are dwarf tapeworm infection and rat tapeworm infection the disease is a type of helminthiasis which is classified as a neglected tropical disease
hyoid bone fracture is a very rare fracture of the hyoid bone accounting for 0 002 of all fractures it is commonly associated with strangulation and rarely occurs in isolation the fracture may be associated with gunshot injury car accidents or induced vomiting in 50 of strangulations and 27 of hangings hyoid fractures occur
hyperimmunoglobulinemia d with recurrent fever hids is a periodic fever syndrome originally described in 1984 by the internist jos van der meer then at leiden university medical centre no more than 300 cases have been described worldwide
hyper igm syndrome type 1 higm 1 is the x linked variant of the hyper igm syndrome the affected individuals are virtually always male because males only have one x chromosome received from their mothers their mothers are not symptomatic even though they are carriers of the allele because the trait is recessive male offspring of these women have a 50 chance of inheriting their mother s mutant allele
in medicine hyper igm syndrome type 2 is a rare disease unlike other hyper igm syndromes the type 2 patients identified thus far did not present with a history of opportunistic infections one would expect opportunistic infections in any immunodeficiency syndrome the putative genetic lesion is in the aicda gene found at 12 p 13 the patients have three common findings the absence of immunoglobulin class switch recombination the lack of immunoglobulin somatic hypermutations and lymph node hyperplasia caused by the presence of giant germinal centers
hyper igm syndrome type 3 is a form of hyper igm syndrome characterized by mutations of the cd 40 gene in this type immature b cells cannot receive signal 2 from helper t cells which is necessary to mature into mature b cells
hyper igm syndrome type 4 is a form of hyper igm syndrome which is a defect in class switch recombination downstream of the aicda gene that does not impair somatic hypermutation
hyper igm syndromes is a group of primary immune deficiency disorders characterized by defective cd 40 signaling by b cells affecting class switch recombination and somatic hypermutation immunoglobulin ig class switch recombination deficiencies csr ds which were previously named dysgammaglobulinemia and then hyper igm syndromes are characterized by elevated or sometimes normal serum immunoglobulin m igm levels and a considerable decrease in or the absence of immunoglobulin g igg immunoglobulin a iga and immunoglobulin e ige – suggesting defective csr as a consequence patients with higm have decreased concentrations of serum igg and iga and normal or elevated igm leading to increased susceptibility to infections the most common higm syndrome is x linked and due to mutations of cd 40 ligand cd 40 l expressed by activated cd 4 t lymphocytes
hyperacusis also spelled hyperacousis is a health condition characterized by an increased sensitivity to certain frequency and volume ranges of sound a collapsed tolerance to usual environmental sound a person with severe hyperacusis has difficulty tolerating everyday sounds some of which may seem unpleasantly or painfully loud to that person but not to others it can be acquired as a result of damage sustained to the hearing apparatus or inner ear there is speculation that the efferent portion of the auditory nerve olivocochlear bundle has been affected efferent meaning fibers that originate in the brain which serve to regulate hearing this theory suggests that the efferent fibers of the auditory nerve are selectively damaged while the hair cells that allow the hearing of pure tones in an audiometric evaluation remain intact in cases not involving aural trauma to the inner ear hyperacusis can also be acquired as a result of damage to the brain or the neurological system in these cases hyperacusis can be defined as a cerebral processing problem specific to how the brain perceives sound in rare cases hyperacusis may be caused by a vestibular disorder this type of hyperacusis called vestibular hyperacusis is caused by the brain perceiving certain sounds as motion input as well as auditory input although severe hyperacusis is rare a lesser form of hyperacusis affects musicians making it difficult for them to play in the very loud environment of a rock band or orchestra which previously gave them no problems it also makes attendance at loud discos or live events difficult for a portion of the population given that sound levels at such events usually exceed recommended safe levels of exposure this is a problem which may be caused by genetic differences stress or ill health or by abnormal responses in the tensor tympani and stapedius muscles which function in the normal acoustic reflex response that protects the inner ear from loud sounds 25 of people with tinnitus report mild hyperacusis
hyperaemia or hyperemia is the increase of blood flow to different tissues in the body it can have medical implications but is also a regulatory response allowing change in blood supply to different tissues through vasodilation clinically hyperaemia in tissues manifest as erythema because of the engorgement of vessels with oxygenated blood hyperaemia can also occur due to a fall in atmospheric pressure outside the body
hyperaldosteronism also aldosteronism is a medical condition wherein too much aldosterone is produced by the adrenal glands which can lead to lowered levels of potassium in the blood hypokalemia and increased hydrogen ion excretion alkalosis most common cause of mineralocorticoid excess is primary hyperaldosteronism reflecting excess production of aldosterone by adrenal zona glomerulosa bilateral micronodular hyperplasia is more common than unilateral adrenal adenoma
hyperalgesia ˌhaɪpərælˈdʒiziə or siə hyper from greek ὑπέρ huper “ over ” algesia from greek algos ἄλγος pain is an increased sensitivity to pain which may be caused by damage to nociceptors or peripheral nerves temporary increased sensitivity to pain also occurs as part of sickness behavior the evolved response to infection
hyperammonemia or hyperammonaemia is a metabolic disturbance characterised by an excess of ammonia in the blood it is a dangerous condition that may lead to encephalopathy and death it may be primary or secondary ammonia is a substance that contains nitrogen it is a product of the catabolism of protein it is converted to the less toxic substance urea prior to excretion in urine by the kidneys the metabolic pathways that synthesize urea involve reactions that start in the mitochondria and then move into the cytosol the process is known as the urea cycle which comprises several enzymes acting in sequence
hyperandrogenism or androgen excess is a medical condition characterized by excessive levels of androgens in the body and the associated effects of these excessive levels of androgens hyperandrogenism is one of the primary symptoms of polycystic ovary syndrome pcos in such cases it presents with symptoms such as acne and seborrhea is frequent in adolescent girls and is often associated with irregular menstrual cycles in most instances these symptoms are transient and reflect only the immaturity of the hypothalamic pituitary ovarian axis during the first years following menarche approximately three quarters of patients with pcos by the diagnostic criteria of nih nichd 1990 have evidence of hyperandrogenism with free testosterone being the single most predictive marker with 60 of patients demonstrating supranormal levels hyperandrogenism can also be the result of excessive production of adrenal or gonadal androgens by adrenal adenomas carcinomas or hyperplasia leydig cell tumors in men and arrhenoblastomas in women in women signs and symptoms of hyperandrogenism frequently include acne scalp hair loss androgenic alopecia excessive facial and body hair hirsutism atypically high libido breast atrophy and others collectively these symptoms are described as virilization management of hyperandrogenism symptoms like androgenic alopecia include the use of antiandrogens such as cyproterone acetate spironolactone and flutamide
hypercalcaemia also spelled hypercalcemia is a high calcium ca 2 level in the blood serum the normal range is 2 1 – 2 6 mmol l 8 8 – 10 7 mg dl 4 3 – 5 2 meq l with levels greater than 2 6 mmol l defined as hypercalcemia those with a mild increase that has developed slowly typically have no symptoms in those with greater levels or rapid onset symptoms may include abdominal pain bone pain confusion depression weakness kidney stones or an abnormal heart rhythm including cardiac arrest most cases are due to primary hyperparathyroidism or cancer other causes include sarcoidosis tuberculosis paget disease multiple endocrine neoplasia men vitamin d toxicity familial hypocalciuric hypercalcaemia and certain medications such as lithium and hydrochlorothiazide diagnosis should generally include either a corrected calcium or ionized calcium level and be confirmed after a week specific changes may be seen on an electrocardiogram ecg treatment may include intravenous fluids furosemide calcitonin or pamidronate in addition to treating the underlying cause the evidence for furosemide however is poor in those with very high levels hospitalization may be required hemodialysis may be used in those who do not respond to other treatments in those with vitamin d toxicity steroids may be useful hypercalcemia is relatively common primary hyperparathyroidism occurs in between one and seven per thousand people and hypercalcemia occurs in about 2 7 of those with cancer
hypercalciuria or hypercalcinuria is the condition of elevated calcium in the urine chronic hypercalcinuria may lead to impairment of renal function nephrocalcinosis and renal insufficiency patients with hypercalciuria have kidneys that put out higher levels of calcium than normal calcium may come from one of two paths through the gut where higher than normal levels of calcium are absorbed by the body or from the bones a bone density scan dsx may be performed to determine if calcium is obtained from the bones hypercalciuria in patients can be due to genetic causes it is managed by increasing fluid intake reducing sodium intake and adding citrate citrate can be added by drinking orange juice or by taking a potassium citrate supplement reducing dietary intake of calcium may be beneficial but severe restriction has not proved beneficial and may even be harmful
hypercapnia also known as hypercarbia and co 2 retention is a condition of abnormally elevated carbon dioxide co 2 levels in the blood carbon dioxide is a gaseous product of the body s metabolism and is normally expelled through the lungs hypercapnia normally triggers a reflex which increases breathing and access to oxygen o such as arousal and turning the head during sleep a failure of this reflex can be fatal for example as a contributory factor in sudden infant death syndrome hypercapnia is the opposite of hypocapnia the state of having abnormally reduced levels of carbon dioxide in the blood the word is from the greek hyper above or too much and kapnos smoke
hypercementosis is an idiopathic non neoplastic condition characterized by the excessive buildup of normal cementum calcified tissue on the roots of one or more teeth a thicker layer of cementum can give the tooth an enlarged appearance which mainly occurs at the apex or apices of the tooth
hyperchloremia is an electrolyte disturbance in which there is an abnormally elevated level of the chloride ion in the blood the normal serum range for chloride is 97 to 107 meq l hyperchloremia is defined as a chloride concentration exceeding this level hyperchloremia can affect oxygen transport
hyperchloremic acidosis is a form of metabolic acidosis associated with a normal anion gap a decrease in plasma bicarbonate concentration and an increase in plasma chloride concentration see anion gap for a fuller explanation although plasma anion gap is normal this condition is often associated with an increased urine anion gap due to the kidney s inability to secrete ammonia
hyperchlorhydria sometimes called chlorhydria refers to the state in the stomach where gastric acid levels are higher than the reference range the combining forms of the name chlor hydr referring to chlorine and hydrogen are the same as those in the name of hydrochloric acid which is the active constituent of gastric acid in humans the normal ph is around 1 to 3 which varies throughout the day the highest basal secretion levels are in the late evening around 12 a m to 3 a m hyperchlorhydria is usually defined as having a ph less than 2 it has no negative consequences unless other conditions are also present such as gastroesophageal reflux disease gerd
hypercholesterolemia also called dyslipidemia is the presence of high levels of cholesterol in the blood it is a form of high blood lipids and hyperlipoproteinemia elevated levels of lipoproteins in the blood elevated levels of non hdl cholesterol and ldl in the blood may be a consequence of diet obesity inherited genetic diseases such as ldl receptor mutations in familial hypercholesterolemia or the presence of other diseases such as diabetes and an underactive thyroid cholesterol is one of three major classes of lipids which all animal cells use to construct their membranes and is thus manufactured by all animal cells plant cells do not manufacture cholesterol it is also the precursor of the steroid hormones and bile acids since cholesterol is insoluble in water it is transported in the blood plasma within protein particles lipoproteins lipoproteins are classified by their density very low density lipoprotein vldl low density lipoprotein ldl intermediate density lipoprotein idl and high density lipoprotein hdl all the lipoproteins carry cholesterol but elevated levels of the lipoproteins other than hdl termed non hdl cholesterol particularly ldl cholesterol are associated with an increased risk of atherosclerosis and coronary heart disease in contrast higher levels of hdl cholesterol are protective avoiding trans fats and replacing saturated fats in adult diets with polyunsaturated fats are recommended dietary measures to reduce total blood cholesterol and ldl in adults in people with very high cholesterol e g familial hypercholesterolemia diet is often not sufficient to achieve the desired lowering of ldl and lipid lowering medications are usually required if necessary other treatments such as ldl apheresis or even surgery for particularly severe subtypes of familial hypercholesterolemia are performed about 34 million adults in the united states have high blood cholesterol
hyperchromicity is the increase of absorbance optical density of a material the most famous example is the hyperchromicity of dna that occurs when the dna duplex is denatured the uv absorption is increased when the two single dna strands are being separated either by heat or by addition of denaturant or by increasing the ph level the opposite a decrease of absorbance is called hypochromicity heat denaturation of dna also called melting causes the double helix structure to unwind to form single stranded dna when dna in solution is heated above its melting temperature usually more than 80 ° c the double stranded dna unwinds to form single stranded dna the bases become unstacked and can thus absorb more light in their native state the bases of dna absorb light in the 260 nm wavelength region when the bases become unstacked the wavelength of maximum absorbance does not change but the amount absorbed increases by 37 a double strand dna dissociating to single strands produces a sharp cooperative transition hyperchromicity can be used to track the condition of dna as temperature changes the transition melting temperature tm is the temperature where the absorbance of uv light is 50 between the maximum and minimum i e where 50 of the dna is denatured the hyperchromic effect is the striking increase in absorbance of dna upon denaturation the two strands of dna are bound together mainly by the stacking interactions hydrogen bonds and hydrophobic effect between the complementary bases the hydrogen bond limits the resonance of the aromatic ring so the absorbance of the sample is limited as well when the dna double helix is treated with denatured agents the interaction force holding the double helical structure is disrupted the double helix then separates into two single strands which are in the random coiled conformation at this time the base base interaction will be reduced increasing the uv absorbance of dna solution because many bases are in free form and do not form hydrogen bonds with complementary bases as a result the absorbance for single stranded dna will be 37 higher than that for double stranded dna at the same concentration
hypercoagulability in pregnancy is the propensity of pregnant women to develop thrombosis blood clots pregnancy itself is a factor of hypercoagulability pregnancy induced hypercoagulability as a physiologically adaptive mechanism to prevent post partum bleeding however when combined with an additional underlying hypercoagulable states the risk of thrombosis or embolism may become substantial
hyperdontia is the condition of having supernumerary teeth or teeth that appear in addition to the regular number of teeth they can appear in any area of the dental arch and can affect any dental organ one of the most well know cases is johncris carl quirante of barangay looc dumanjug cebu who has 300 teeth
hyperdynamic precordium is a condition where the precordium the area of the chest over the heart moves too much is hyper dynamic due to some pathology of the heart this problem can be hypertrophy of the ventricles tachycardia or some other heart problem hyperdynamic precordium can also be due to hyperthyroidism and thus indicates an increased cardiac contractility with systolic hypertension it may also be due to aortic coarctation and most other congenital heart malformations palpation of the chest wall can be done to assess volume changes within the heart a hyperdynamic precordium reflects a large volume change
hyperekplexia exaggerated surprise is a neurologic disorder classically characterised by pronounced startle responses to tactile or acoustic stimuli and hypertonia the hypertonia may be predominantly truncal attenuated during sleep and less prominent after a year of age classic hyperekplexia is caused by genetic mutations in a number of different genes all of which play an important role in glycine neurotransmission glycine is used by the central nervous system as an inhibitory neurotransmitter hyperekplexia is generally classified as a genetic disease but some disorders can mimic the exaggerated startle of hyperekplexia
hyperemesis gravidarum hg is a complication of pregnancy that is characterized by severe nausea and vomiting such that weight loss and dehydration occur signs and symptoms may include vomiting several times a day and feeling faint it is more severe than morning sickness often symptoms get better after the 20 th week of pregnancy but may last the entire pregnancy the exact cause of hyperemesis gravidarum is not known risk factors include the first pregnancy multiple pregnancy obesity prior or family history of hyperemesis gravidarum trophoblastic disorder and a history of an eating disorder the diagnosis is usually made based on the signs and symptoms it has been technically defined as more than three episodes of vomiting per day such that weight loss of 5 or three kilograms has occurred and ketones are present in the urine other potential causes of the symptoms should be excluded including urinary tract infection and high thyroid levels treatment includes drinking fluids and a bland diet recommendations may include electrolyte replacement drinks thiamine and a higher protein diet some women require intravenous fluids with respect to medications pyridoxine or metoclopramide are preferred prochlorperazine dimenhydrinate or ondansetron may be used if these are not effective hospitalization may be required psychotherapy may improve outcomes evidence for acupressure is poor while vomiting in pregnancy has been described as early as 2 000 bc the first clear medically description of hyperemesis gravidarum was in 1852 by antoine dubois hyperemesis gravidarum is estimated to affect 0 3 – 2 0 of pregnant women while previously a common cause of death in pregnancy with proper treatment this is now very rare those affected have a low risk of miscarriage but a higher risk of premature birth some women opt to have an abortion because of the symptoms
hypereosinophilia or hypereosinophilic syndrome is a disease characterised by a marked increase in the eosinophil count in the bloodstream the eosinophil count in human blood is normally 0 4 × 109 l 0 1 0 6 and results from a balance between production of eosinophils and emigration through post capillary venules yamaguchi et al 1991 eosinophils are only a small minority of peripheral blood leucocytes and in normal subjects most are found in the tissues of the lung and gastro intestinal tract beeken et al 1987 blood eosinophil counts are arbitrarily classified as mild between 0 6 to 1 5 × 109 l moderate between 1 5 to 5 × 109 l and severe when greater than 5 × 109 l an elevated blood eosinophil count may be associated with a number of reactive conditions and with clonal disorders of the bone marrow however when the blood eosinophil count is persistently greater than 1 5 × 109 l for a period of more than six months damage to end organs such as the heart lungs skin joints and nervous system can be demonstrated and in the absence of any clonal or reactive cause the term idiopathic hypereosinophilic syndrome hes is used the three defining criteria of hes are therefore 1 eosinophil count persistently greater than 1 5 × 109 l 2 damage to end organs 3 no ascertainable cause for the eosinophilia and no evidence of clonality there are three categories of blood eosinophilia reactive non clonal eosinophilia infections parasitic infestations asthma and allergies respiratory diseases cytokine infusions vasculitides non haematological malignant diseases drug reactions and connective tissue diseases hodgkin s and non hodgkin s lymphomas are included here as the eosinophils have not been shown to be clonal clonal disorders of the bone marrow associated with eosinophilia acute and chronic eosinophilic leukaemia chronic myeloid leukaemia polycythaemia rubra vera essential thrombocythaemia acute myeloid leukaemia chromosome 16 variants the 8 p 11 myeloproliferative syndrome ems and t lymphoblastic lymphoma with eosinophilia acute lymphoblastic leukaemia myelodysplastic disorders mds with eosinophilia systemic mastocytosis and acute lymphoblastic leukaemia bain 1996 hes after exclusion of the above two categories cases of persistent unexplained eosinophilia fall into the category of hes
the hypereosinophilic syndrome hes is a disease characterized by a persistently elevated eosinophil count ≥ 1500 eosinophils mm ³ in the blood for at least six months without any recognizable cause with involvement of either the heart nervous system or bone marrow hes is a diagnosis of exclusion after clonal eosinophilia such as leukemia and reactive eosinophilia in response to infection autoimmune disease atopy hypoadrenalism tropical eosinophilia or cancer have been ruled out there are some associations with chronic eosinophilic leukemia as it shows similar characteristics and genetic defects if left untreated hes is progressively fatal it is treated with glucocorticoids such as prednisone the addition of the monoclonal antibody mepolizumab may reduce the dose of glucocorticoids
hyperesthesia or hyperaesthesia is a condition that involves an abnormal increase in sensitivity to stimuli of the sense when a non noxious stimulus causes the sensation of pain the area will be termed hyperaesthetic stimuli of the senses can include sound that one hears foods that one tastes textures that one feels and so forth increased touch sensitivity is referred to as tactile hyperesthesia and increased sound sensitivity is called auditory hyperesthesia tactile hyperesthesia may be a common symptom of many neurologic disorders such as herpes zoster peripheral neuropathy and radiculopathies in 1979 and then in 1994 merskey bogduk noordenbos devor and others a subcommittee of international association for the study of pain proposed instead of hyperaestheia the concept of allodynia meaning other pain defined as a pain resulting from a stimulus that does not normally provoke pain in psychology jeanne siaud facchin uses the term by defining it as an exacerbation des sens that characterizes gifted children and adults for them the sensory information reaches the brain much faster than the average and the information is processed in a significantly shorter time
hyperestrogenism hyperestrogenic state or estrogen excess is a medical condition characterized by an excessive amount of estrogenic activity in the body
hypergammaglobulinemia is a medical condition with elevated levels of gamma globulin it is a type of immunoproliferative disorder
in mathematics the gaussian or ordinary hypergeometric function 2 f 1 a b c z is a special function represented by the hypergeometric series that includes many other special functions as specific or limiting cases it is a solution of a second order linear ordinary differential equation ode every second order linear ode with three regular singular points can be transformed into this equation for systematic lists of some of the many thousands of published identities involving the hypergeometric function see the reference works by and there is no known system for organizing all of the identities indeed there is no known algorithm that can generate all identities a number of different algorithms are known that generate different series of identities the theory of the algorithmic discovery of identities remains an active research topic
hypergeusia is a taste disorder where the sense is abnormally heightened it can be associated with a lesion of the posterior fossa and addison s disease where a patient will crave for salty and sour taste due to the abnormal loss of ions with urine
hyperglycemia or high blood sugar also spelled hyperglycaemia or hyperglycæmia is a condition in which an excessive amount of glucose circulates in the blood plasma this is generally a blood sugar level higher than 11 1 mmol l 200 mg dl but symptoms may not start to become noticeable until even higher values such as 15 – 20 mmol l 250 – 300 mg dl a subject with a consistent range between 5 6 and 7 mmol l 100 – 126 mg dl american diabetes association guidelines is considered hyperglycemic while above 7 mmol l 126 mg dl is generally held to have diabetes chronic levels exceeding 7 mmol l 125 mg dl can produce organ damage
hyperglycerolemia also known as glycerol kinase deficiency gkd is a genetic disorder where the enzyme glycerol kinase is deficient resulting in a build up of glycerol in the body glycerol kinase is responsible for synthesizing triglycerides and glycerophospholipids in the body excess amounts of glycerol can be found in the blood and or urine hyperglycerolmia occurs more frequently in males hyperglycerolemia is listed as a “ rare disease ” by the office of rare diseases ord of the national institutes of health nih which means it affects less than 200 000 people in the us population u s department of health human services
hypergonadism is a condition where there is a hyperfunction of the gonads it can manifest as precocious puberty and is caused by abnormally high levels of testosterone or estrogen crucial hormones for sexual development in some cases it may be caused by a tumor which can be malignant but mostly benign anabolic steroids may also be a major cause of high androgen and or estrogen functional activity symptoms of the condition may include precocious puberty rapid growth in adolescents high libido acne excessive hairiness and others
hypergonadotropic hypogonadism hh also known as primary or peripheral gonadal hypogonadism is a condition which is characterized by hypogonadism due to an impaired response of the gonads to the gonadotropins follicle stimulating hormone fsh and luteinizing hormone lh and in turn a lack of sex steroid production and elevated gonadotropin levels as an attempt of compensation by the body hh may present as either congenital or acquired but the majority of cases are of the former nature
hypergraphia is a behavioral condition characterized by the intense desire to write forms of hypergraphia can vary in writing style and content it is a symptom associated with temporal lobe changes in epilepsy which is the cause of the geschwind syndrome a mental disorder structures that may have an effect on hypergraphia when damaged due to temporal lobe epilepsy are the hippocampus and wernicke s area aside from temporal lobe epilepsy chemical causes may be responsible for inducing hypergraphia
anorexia athletica is used to refer to a disorder for athletes who engage in at least one unhealthy method of weight control unlike anorexia nervosa anorexia athletica does not have as much to do with body image as it does with performance athletes usually begin by eating more healthy foods as well as increasing their training but when people feel like that is not enough and start working out excessively and cutting back their caloric intake until it becomes a psychological disorder hypergymnasia and anorexia athletica are not recognized as mental disorders in any of the medical manuals such as the icd 10 or the dsm iv nor is it part of the proposed revision of this manual the dsm 5 if this was the case there would be a 10 15 increase in mental disorders in sports a study at the anorexia centre at huddinge hospital in stockholm sweden showed that sports anorexia can result in mental disorders the anxiety stress and pressure people with sports anorexia put on themselves as well as the pressure parents and coaches can put on the athlete can cause mental disorders
hyperhidrosis is a condition characterized by abnormally increased sweating in excess of that required for regulation of body temperature hyperhidrosis can be associated with a quality of life burden from a psychological emotional and social perspective it has been called by some the silent handicap both the words diaphoresis and hidrosis can mean either perspiration in which sense they are synonymous with sweating or excessive perspiration in which case they refer to a specific narrowly defined clinical disorder
hyperhomocysteinemia or hyperhomocysteinaemia is a medical condition characterized by an abnormally high level of homocysteine in the blood conventionally described as above 15 µmol l as a consequence of the biochemical reactions in which homocysteine is involved deficiencies of vitamin b 6 folic acid vitamin b 9 and vitamin b 12 can lead to high homocysteine levels hyperhomocysteinemia is typically managed with vitamin b 6 vitamin b 9 and vitamin b 12 supplementation in individuals with genetic mthfr deficiencies the methylated version of those 3 vitamins must be used or supplementation can make the condition worse taurine supplementation also has been found to reduce homocysteine levels
hyperhydricity previously known as vitrification is a physiological malformation that results in excessive hydration low lignification impaired stomatal function and reduced mechanical strength of tissue culture generated plants the consequence is poor regeneration of such plants without intensive greenhouse acclimation for outdoor growth additionally it may also lead to leaf tip and bud necrosis in some cases which often leads to loss of apical dominance in the shoots in general the main symptom of hyperhydricity is translucent characteristics signified by a shortage of chlorophyll and high water content specifically the presence of a thin or absent cuticular layer reduced number of palisade cells irregular stomata less developed cell wall and large intracellular spaces in the mesophyll cell layer have been described as some of the anatomic changes associated with hyperhydricity
hyperimmunoglobulinemia e syndrome hies of which the autosomal dominant form is called job s syndrome or buckley syndrome is a heterogeneous group of immune disorders
hyperinsulinemia or hyperinsulinaemia is a condition in which there are excess levels of insulin circulating in the blood relative to the level of glucose while it is often mistaken for diabetes or hyperglycaemia hyperinsulinemia can result from a variety of metabolic diseases and conditions while hyperinsulinemia is often seen in people with early stage type 2 diabetes mellitus it is not the cause of the condition and is only one symptom of the disease type 1 diabetes only occurs when pancreatic beta cell function is impaired hyperinsulinemia can be seen in a variety of conditions including diabetes mellitus type 2 in neonates and in drug induced hyperinsulinemia it can also occur in congenital hyperinsulism including nesidioblastosis hyperinsulinemia is associated with hypertension obesity dyslipidemia and glucose intolerance these conditions are collectively known as metabolic syndrome this close association between hyperinsulinemia and conditions of metabolic syndrome suggest related or common mechanisms of pathogenicity hyperinsulinemia has been shown to play a role in obese hypertension by increasing renal sodium retention in type 2 diabetes the cells of the body become resistant to the effects of insulin as the receptors which bind to the hormone become less sensitive to insulin concentrations resulting in hyperinsulinemia and disturbances in insulin release with a reduced response to insulin the beta cells of the pancreas secrete increasing amounts of insulin in response to the continued high blood glucose levels resulting in hyperinsulinemia in insulin resistant tissues a threshold concentration of insulin is reached causing the cells to uptake glucose and therefore decreases blood glucose levels studies have shown that the high levels of insulin resulting from insulin resistance might enhance insulin resistance studies on mice with genetically reduced circulating insulin suggest that hyperinsulinemia plays a causal role in high fat diet induced obesity in this study mice with reduced insulin levels expended more energy and had fat cells that were reprogrammed to burn some energy as heat hyperinsulinemia in neonates can be the result of a variety of environmental and genetic factors if the mother of the infant is a diabetic and does not properly control her blood glucose levels the hyperglycemic maternal blood can create a hyperglycemic environment in the fetus to compensate for the increased blood glucose levels fetal pancreatic beta cells can undergo hyperplasia the rapid division of beta cells results in increased levels of insulin being secreted to compensate for the high blood glucose levels following birth the hyperglycemic maternal blood is no longer accessible to the neonate resulting in a rapid drop in the newborn ’ s blood glucose levels as insulin levels are still elevated this results in hyperinsulinemia to treat the condition high concentration doses of glucose are given to the neonate as required maintaining normal blood glucose levels the hyperinsulinemia condition subsides after one to two days
hyperinsulinism refers to an above normal level of insulin in the blood of a person or animal normal insulin secretion and blood levels are closely related to the level of glucose in the blood so that a given level of insulin can be normal for one blood glucose level but low or high for another hyperinsulinism can be associated with several types of medical problems which can be roughly divided into two broad and largely non overlapping categories those tending toward reduced sensitivity to insulin and high blood glucose levels hyperglycemia and those tending toward excessive insulin secretion and low glucose levels hypoglycemia
hyperkalemia also spelled hyperkalaemia is an elevated level of potassium k in the blood serum normal potassium levels are between 3 5 and 5 0 mmol l 3 5 and 5 0 meq l with levels above 5 5 mmol l defined as hyperkalemia typically this results in no symptoms occasionally when severe it results in palpitations muscle pain muscle weakness or numbness an abnormal heart rate can occur which can result in cardiac arrest and death common causes include renal failure hypoaldosteronism and rhabdomyolysis a number of medications can also cause high blood potassium including spironolactone nsaids and angiotensin converting enzyme inhibitors the severity is divided into mild 5 5 5 9 mmol l moderate 6 0 6 4 mmol l and severe 6 5 mmol l high levels can also be detected on an electrocardiogram ecg pseudohyperkalemia due to breakdown of cells during or after taking the blood sample should be ruled out initial treatment in those with ecg changes is calcium gluconate medications that might worsen the condition should be stopped and a low potassium diet should be recommended other medications used include dextrose with insulin salbutamol and sodium bicarbonate measures to remove potassium from the body include furosemide polystyrene sulfonate and hemodialysis hemodialysis is the most effective method the use of polystyrene sulfonate while common is poorly supported by evidence hyperkalemia is rare among those who are otherwise healthy among those who are in hospital rates are between 1 and 2 5 it increases the overall risk of death by at least ten times the word hyperkalemia is from hyper meaning high kalium meaning potassium and emia meaning in the blood
hyperkalemic periodic paralysis hypp hyperkpp is a genetic disorder it occurs in humans horses where it is also known as impressive syndrome after an index case in a horse named impressive or possibly one of his ancestors and perhaps other animals it is an inherited autosomal dominant disorder that affects sodium channels in muscle cells and the ability to regulate potassium levels in the blood it is most commonly associated with horses but occurs in humans where it may be called gamstorp episodic adynamy it is characterized by muscle hyperexcitability or weakness which exacerbated by potassium heat or cold can lead to uncontrolled shaking followed by paralysis onset in humans usually occurs in early childhood but still occurs with adults the mutation which causes this disorder is dominant on scn 4 a with linkage to the sodium channel expressed in muscle the mutation causes single amino acid changes in parts of the channel which are important for inactivation in the presence of high potassium levels including those induced by diet sodium channels fail to inactivate properly equine hyperkalemic periodic paralysis occurs in 1 in 50 quarter horses and can be traced to a single ancestor a stallion named impressive
hyperkeratinization american english or hyperkeratinisation in english language is a disorder of the cells lining the inside of a hair follicle it is the normal function of these cells to detach or slough off desquamate from the skin lining at normal intervals the dead cells are then forced out of the follicle primarily by the growing hair however in hyperkeratinization this process is interrupted and a number of these dead skin cells do not leave the follicle because of an excess of keratin a natural protein found in the skin this excess of keratin which is influenced by genetics results in an increased adherence bonding of dead skin cells together this cohesion of cells will block or cap the hair follicle leading to keratosis pilaris or clog the sebaceous oil duct leading to acne pathogens may also play a role in causing perpetuating or simply taking advantage of this phenomenon such as virulent sub strains of propionibacterium acnes and irregular migration of staphylococcus epidermidis from the outer surface of the skin into the follicle where commensal strains of p acnes exclusively habitate it itches mildly at times and strongly at others very often it cannot be felt at all
hyperkeratosis is thickening of the stratum corneum the outermost layer of the epidermis often associated with the presence of an abnormal quantity of keratin and also usually accompanied by an increase in the granular layer as the corneum layer normally varies greatly in thickness in different sites some experience is needed to assess minor degrees of hyperkeratosis it can be caused by vitamin a deficiency or chronic exposure to arsenic hyperkeratosis can also be caused by b raf inhibitor drugs such as vemurafenib and dabrafenib it can be treated with urea containing creams which dissolve the intercellular matrix of the cells of the stratum corneum promoting desquamation of scaly skin eventually resulting in softening of hyperkeratotic areas
hyperkeratotic cutaneous capillary venous malformation is a cutaneous condition characterized also by inherited cerebral capillary malformations
hyperkeratotic hand dermatitis presents with hyperkeratotic fissure prone erythematous areas of the middle or proximal palm and the volar surfaces of the fingers may also be involved
hyperkinetic disorder is a psychiatric syndrome emerging in early childhood that features an enduring pattern of severe developmentally inappropriate inattention hyperactivity and impulsivity across different settings e g home and school that significantly impair academic social and work performance hyperkinetic children display disorganized poorly controlled and excessive activity they lack perseverance in tasks involving thought and attention and tend to move from one activity to the next without completing any they are frequently accident prone reckless and impulsive and may thoughtlessly rather than defiantly break rules while they are commonly incautious and unreserved with adults they may be isolated and unpopular with other children cognitive impairment and delayed language and motor development are more common in this group than in the general population and they may experience low self esteem and engage in dissocial behavior as a consequence of the disorder
hyperlexia is a syndrome characterized by a child s precocious ability to read combined with difficulty in understanding and using verbal language and problems with social interactions it was initially identified by norman e silberberg and margaret c silberberg 1967 who defined it as the precocious ability to read words without prior training in learning to read typically before the age of 5 they indicated that children with hyperlexia have a significantly higher word decoding ability than their reading comprehension levels hyperlexic children are characterized by having average or above average iqs and word reading ability well above what would be expected given their age first named and scientifically described in 1967 silverberg and silverberg it can be viewed as a superability in which word recognition ability goes far above expected levels of skill some hyperlexics however have trouble understanding speech some experts believe that most or perhaps all children with hyperlexia lie on the autism spectrum however one expert darold treffert proposes that hyperlexia has subtypes only some of which overlap with autism between 5 and 10 percent of children with autism have been estimated to be hyperlexic hyperlexic children are often fascinated by letters or numbers they are extremely good at decoding language and thus often become very early readers some hyperlexic children learn to spell long words such as elephant before they are two years old and learn to read whole sentences before they turn three an fmri study of a single child showed that hyperlexia may be the neurological opposite of dyslexia
hyperlipidemia is abnormally elevated levels of any or all lipids and or lipoproteins in the blood it is the most common form of dyslipidemia which includes any abnormal lipid levels lipids water insoluble molecules are transported in a protein capsule the size of that capsule or lipoprotein determines its density the lipoprotein density and type of apolipoproteins it contains determines the fate of the particle and its influence on metabolism hyperlipidemias are divided into primary and secondary subtypes primary hyperlipidemia is usually due to genetic causes such as a mutation in a receptor protein while secondary hyperlipidemia arises due to other underlying causes such as diabetes lipid and lipoprotein abnormalities are common in the general population and are regarded as a modifiable risk factor for cardiovascular disease due to their influence on atherosclerosis in addition some forms may predispose to acute pancreatitis
hyperlysinemia is an autosomal recessive metabolic disorder characterized by an abnormal increase of lysine in the blood but appears to be benign it is caused by mutations in aass which encodes α aminoadipic semialdehyde synthase hyperlysinemia is associated with ectopia lentis a displacement or malposition of the eye s crystalline lens in humans
hypermagnesemia is an electrolyte disturbance in which there is a high level of magnesium in the blood it is defined as a level greater than 1 1 mmol l symptoms include weakness confusion decreased breathing rate and cardiac arrest hypermagnesemia can occur in kidney failure and those who are given magnesium salts or who take drugs that contain magnesium e g some antacids and laxatives it is usually concurrent with other electrolyte disturbances such as a low blood calcium and or high blood potassium level specific electrocardiogram ecg changes may be present treatment when levels are very high include calcium chloride intravenous normal saline with furosemide and hemodialysis hypermagnesemia occurs rarely because the kidney is very effective in excreting excess magnesium
hypermobility describes joints that stretch further than normal for example some hypermobile people can bend their thumbs backwards to their wrists bend their knee joints backwards put their leg behind the head or perform other contortionist tricks it can affect one or more joints throughout the body when present in the hands it is colloquially referred to as double jointedness
hypermorphosis is a biological phenomenon related to the development time and rate of an organism hypermorphosis is a heterochronic process i e a change in the timing or rate of development in an organism in hypermorphosis the rate of development of an organism is not altered but the time of offset of the change in question is extended for example it is common knowledge that major physical changes in the human body are completed by the time someone is 18 years of age in cases of hypermorphosis however the changes continue to take place after the normal time frame hypermorphosis may serve to explain evolution in certain cases for instance the occurrence of this phenomenon with respect to cognitive functions in apes may have resulted in a gradual increase in intelligence the end result being intelligent human beings
hypernasal speech also hyperrhinolalia or open nasality medically known as rhinolalia aperta from latin rhinolalia nasal speech and aperta open is a disorder that causes abnormal resonance in a human s voice due to increased airflow through the nose during speech it is caused by an open nasal cavity resulting from an incomplete closure of the soft palate and or velopharyngeal sphincter in normal speech nasality is referred to as nasalization and is a linguistic category that can apply to vowels or consonants in a specific language the primary underlying physical variable determining the degree of nasality in normal speech is the opening and closing of a velopharyngeal passageway between the oral vocal tract and the nasal vocal tract in the normal vocal tract anatomy this opening is controlled by lowering and raising the velum or soft palate to open or close respectively the velopharyngeal passageway
hypernatremia also spelled hypernatraemia is a high sodium level in the blood early symptoms may include a strong feeling of thirst weakness nausea and loss of appetite severe symptoms include confusion muscle twitching and bleeding in or around the brain normal serum sodium levels are 135 145 mmol l 135 145 meq l hypernatremia is generally defined as a serum sodium level of more than 145 mmol l severe symptoms typically only occur when levels are above 160 mmol l the cause of hypernatremia is typically classified by a person s fluid status into low volume normal volume and high volume low volume hypernatremia can occur from sweating vomiting diarrhea diuretic medication or kidney disease normal volume hypernatremia can be due to fever inappropriately decreased thirst a prolonged increased breath rate and diabetes insipidus from lithium among other causes high volume hypernatremia can be due to hyperaldosteronism be health care caused such as when too much intravenous 3 normal saline or sodium bicarb is given or rarely be from eating too much salt low blood protein levels can result in a falsely high sodium measurement the cause can usually be determined by the history of events testing the urine can help if the cause is unclear if the onset of hypernatremia was over a few hours than it can be corrected relatively quickly using intravenous normal saline and 5 dextrose otherwise correction should occur slowly with for those unable to drink water half normal saline hypernatremia due to diabetes insipidus as a result of a brain disorder may be treated with the medication desmopressin if the diabetes insipidus is due to kidney problems the medication which is causing it may need to be stopped hypernatremia affects 0 3 1 of people in hospital it most often occurs in babies those with impaired mental status and those who are old hypernatremia is associated with an increases the risk of death but it is unclear if it is the cause
hyperosmia is an increased olfactory acuity heightened sense of smell usually caused by a lower threshold for odor this perceptual disorder arises when there is an abnormally increased signal at any point between the olfactory receptors and the olfactory cortex the causes of hyperosmia may be genetic environmental or the result of benzodiazepine withdrawal syndrome when odorants enter the nasal cavity they bind to odorant receptors at the base of the olfactory epithelium these receptors are bipolar neurons that connect to the glomerular layer of the olfactory bulb traveling through the cribriform plate at the glomerular layer axons from the olfactory receptor neurons intermingle with dendrites from intrinsic olfactory bulb neurons mitrial tufted cells and dopaminergic periglomerular cells from the olfactory bulb mitral tufted cells send axons via the lateral olfactory tract the cranial nerve i to the olfactory cortex which includes the piriform cortex entorhinal cortex and parts of the amygdala from the entorhinal cortex axons extend to the medial dorsal nucleus of the thalamus which then proceed to the orbitofrontal cortex
hyperosmolar hyperglycemic state hhs is a complication of diabetes mellitus predominantly type 2 in which high blood sugars cause severe dehydration increases in osmolarity relative concentration of solute and a high risk of complications coma and death it is diagnosed with blood tests it is related to diabetic ketoacidosis dka another complication of diabetes more often but not exclusively encountered in people with type 1 diabetes they are differentiated with measurement of ketone bodies organic molecules that are the underlying driver for dka but are usually not detectable in hhs the treatment of hhs consists of correction of the dehydration with intravenous fluids reduction of the blood sugar levels with insulin and management of any underlying conditions that might have precipitated the illness such as an acute infection older names for hhs are hyperosmolar hyperglycemic nonketotic coma hhnc hyperosmolar non ketotic coma honk nonketotic hyperosmolar coma hyperosmolar hyperglycemic nonketotic syndrome hhns favoured by the american diabetes association
hyperosmolar syndrome or diabetic hyperosmolar syndrome is a medical emergency caused by a very high blood glucose level the prefix hyper means high and osmolarity is a measure of the concentration of active particles in a solution so the name of the syndrome simply refers to the high concentration of glucose in the blood
hyperostosis is an excessive growth of bone it may lead to exostosis it occurs in many musculoskeletal disorders
hyperostosis frontalis interna is a common benign thickening of the inner side of the frontal bone of the skull it is found predominantly in women after menopause and is usually asymptomatic mostly frequently it is found as an incidental finding discovered during an x ray or ct scan of the skull
in the context of machine learning hyperparameter optimization or model selection is the problem of choosing a set of hyperparameters for a learning algorithm usually with the goal of optimizing a measure of the algorithm s performance on an independent data set often cross validation is used to estimate this generalization performance hyperparameter optimization contrasts with actual learning problems which are also often cast as optimization problems but optimize a loss function on the training set alone in effect learning algorithms learn parameters that model reconstruct their inputs well while hyperparameter optimization is to ensure the model does not overfit its data by tuning e g regularization
hyperparathyroidism is an increased parathyroid hormone pth levels in the blood this occurs either from the parathyroid glands inappropriately making too much pth primarily hyperparathyroidism or other events triggering increased production by the parathyroid glands secondary hyperparathyroidism most people with primary disease have no symptoms at the time of diagnosis in those with symptoms the most common is kidney stones with other potential symptoms including weakness depression bone pains confusion and increased urination both types increase the risk of weak bones primary hyperparathyroidism in 80 of cases is due to a single benign tumor known as a parathyroid adenoma with most of the rest of the cases due to a multiple benign tumors rarely it may be due to parathyroid cancer secondary hyperparathyroidism typically occurs due to vitamin d deficiency chronic kidney disease or other causes of low blood calcium diagnosis of primary disease is by finding a high blood calcium and high pth levels primary hyperparathyroidism may be cured by removing the adenoma or overactive parathyroid glands in those without symptoms mildly increased blood calcium levels normal kidneys and normal bone density monitoring may be all that is required the medication cinacalcet may also be used to decrease pth levels in those with very high blood calcium levels treatment may include large amounts of intravenous normal saline low vitamin d levels should be corrected primary hyperparathyroidism is the most common form in the developed world between one and four per thousand people are affected it occurs three times more often in women than men and is typically diagnosed between the ages of 50 and 60 the disease was first described in the 1700 s and in the late 1800 s was determined to be related to the parathyroid surgery as a treatment was first carried out in 1925
hyperpathia is a clinical symptom of certain neurological disorders wherein nociceptive stimuli evoke exaggerated levels of pain this should not be confused with allodynia where normally non painful stimuli evoke pain
hyperphenylalaninemia is a medical condition characterized by mildly or strongly elevated concentrations of the amino acid phenylalanine in the blood phenylketonuria pku can result in severe hyperphenylalaninemia phenylalanine concentrations phe are routinely screened in newborns by the neonatal heel prick guthrie test which takes a few drops of blood from the heel of the infant standard phe concentrations in unaffected persons are about 60 µm phe concentrations in persons with untreated phenylketonuria may be many times that 600 µm to 2400 µm which indicate that the child is at risk for severe intellectual disability phenylketonuria is classed as an autosomal recessive condition in heterozygous form phe shows a moderate elevation perhaps two fold over that of unaffected homozygotes which is classified as hyperphenylalaninemia hyper phenylalanine emia high phe in blood persons with the genotype for pku are unaffected in utero because maternal circulation prevents buildup of phe after birth pku in newborns is treated by a special diet with highly restricted phenylalanine content persons with genetic predisposition to pku have normal mental development on this diet previously it was thought safe to withdraw from the diet in the late teens or early twenties after the central nervous system was fully developed recent studies suggest some degree of relapse and a continued phenylalanine restricted diet is now recommended pku or hyperphenylalaninemia may also occur in persons without the pku genotype if the mother has the pku genotype but has been treated so as to be asymptomatic high levels of phe in the maternal blood circulation may affect the non pku fetus during gestation mothers successfully treated for pku are advised to return to the phe restricted diet during pregnancy a small subset of patients with hyperphenylalaninemia shows an appropriate reduction in plasma phenylalanine levels with dietary restriction of this amino acid however these patients still develop progressive neurologic symptoms and seizures and usually die within the first 2 years of life malignant hyperphenylalaninemia these infants exhibit normal phenylalanine hydroxylase pah enzymatic activity but have a deficiency in dihydropteridine reductase dhpr an enzyme required for the regeneration of tetrahydrobiopterin thb a cofactor of pah less frequently dhpr activity is normal but a defect in the biosynthesis of thb exists in either case dietary therapy corrects the hyperphenylalaninemia however thb is also a cofactor for two other hydroxylation reactions required in the syntheses of neurotransmitters in the brain the hydroxylation of tryptophan to 5 hydroxytryptophan and of tyrosine to l dopa it has been suggested that the resulting deficit in the cns neurotransmitter activity is at least in part responsible for the neurologic manifestations and eventual death of these patients
hyperphosphatasia with mental retardation syndrome hpmrs also known as mabry syndrome has been described in patients recruited on four continents world wide mabry syndrome was confirmed to represent an autosomal recessive syndrome characterized by severe mental retardation considerably elevated serum levels of alkaline phosphatase hypoplastic terminal phalanges and distinct facial features that include hypertelorism a broad nasal bridge and a rectangular face
hyperphosphatemia is an electrolyte disturbance in which there is an abnormally elevated level of phosphate in the blood often calcium levels are lowered hypocalcemia due to precipitation of phosphate with the calcium in tissues average phosphorus levels should be between 0 81 mmol l and 1 45 mmol l
hyperpituitarism is a condition due to the primary hypersecretion of pituitary hormones it typically results from a pituitary adenoma children with hyperpituitarism is rare disruption of growth regulation either because of hormone hypersecretion or because of manifestations caused by local compression of the adenoma can occur
hyperplasia from ancient greek ὑπέρ huper over πλάσις plasis formation or hypergenesis is an increase in the amount of organic tissue that results from cell proliferation it may lead to the gross enlargement of an organ and the term is sometimes confused with benign neoplasia or benign tumor hyperplasia is a common preneoplastic response to stimulus microscopically cells resemble normal cells but are increased in numbers sometimes cells may also be increased in size hypertrophy hyperplasia is different from hypertrophy in that the adaptive cell change in hypertrophy is an increase in the size of cells whereas hyperplasia involves an increase in the number of cells
hyperproinsulinemia is a disease where insulin is not sufficiently processed before secretion and immature forms of insulin make up the majority of circulating insulin immunoreactivity in both fasting and glucose stimulated conditions insulin immunoreactivity refers to all molecules detectable by an insulin antibody i e insulin proinsulin and proinsulin like material the term is composed of hyper high proinsulin immature insulin molecule and emia blood condition hyperproinsulinemia is more frequent in type 2 diabetes it has been attributed to either a direct β cells defect or an indirect effect of cell dysregulation under sustained elevated blood glucose hyperglycemia some alleles of insulin can cause hyperproinsulinemia see table 2 monogenic forms of type 1 diabetes ins insulin for a more detailed descriptions of the insulin gene variations leading to hyperproinsulinemia see ncbi s omim 176730
hyperprolactinaemia or hyperprolactinemia is the presence of abnormally high levels of prolactin in the blood normal levels are less than 500 miu l 20 ng ml or µg l for women and less than 450 miu l for men prolactin is a peptide hormone produced by the anterior pituitary gland that is primarily associated with lactation and plays a vital role in breast development during pregnancy hyperprolactinaemia may cause galactorrhea production and spontaneous flow of breast milk and disruptions in the normal menstrual period in women and hypogonadism infertility and erectile dysfunction in men hyperprolactinaemia can be a part of normal body changes during pregnancy and breastfeeding it can also be caused by diseases affecting the hypothalamus and pituitary gland it can also be caused by disruption of the normal regulation of prolactin levels by drugs medicinal herbs and heavy metals hyperprolactinaemia may also be the result of disease of other organs such as the liver kidneys ovaries and thyroid
hyperprolactinemic saha syndrome is a cutaneous condition characterized by lateral hairiness oligomenorrhea and sometimes acne seborrhea faga i and even galactorrhea
hyperprolinemia also referred to as prolinemia or prolinuria is a condition which occurs when the amino acid proline is not broken down properly by the enzymes proline oxidase or pyrroline 5 carboxylate dehydrogenase causing a buildup of proline in the body
hyperproteinemia is the state of having overly high levels of protein in the blood this can occur due to monoclonal gammopathies such as multiple myeloma and after intravenous immunoglobulin has been given it can result in a falsely low appearing sodium level hyponatremia
hypersalivation also called ptyalism or sialorrhea is excessive production of saliva it has also been defined as increased amount of saliva in the mouth which may also be caused by decreased clearance of saliva hypersalivation can contribute to drooling if there is an inability to keep the mouth closed or in difficulty in swallowing the excess saliva dysphagia hypersalivation also often precedes emesis vomiting where it accompanies nausea a feeling of needing to vomit
in computing hyperscale is the ability of an architecture to scale appropriately as increased demand is added to the system this typically involves the ability to seamlessly provision and add compute memory networking and storage resources to a given node or set of nodes that make up a larger computing distributed computing or grid computing environment hyperscale computing is necessary in order to build a robust and scalable cloud big data map reduce or distributed storage system and is often associated with the infrastructure required to run large distributed sites such as facebook google microsoft or amazon companies like ericsson and intel provide hyperscale infrastructure kits to any it service provider wanting to modernise their infrastructure and adopt hyperscale
a hypersegmented neutrophil is a clinical laboratory finding it is visualized by drawing blood from a patient and viewing the blood smeared on a slide under a microscope normally the number of segments in the nucleus of a neutrophil increases as it matures and ages after the neutrophil is released into the blood from the bone marrow although normal neutrophils only contain three or four nuclear lobes the segments hypersegmented neutrophils contain six or more lobes hypersegmented neutrophils have classically been thought to be pathognomonic of the class of anemias called megaloblastic anemias anemias caused by failure of bone marrow blood forming cells to make dna often caused by vitamin b 12 or folate deficiencies or dna replication poisons however in seeming contradiction to this several studies have strongly associated neutrophil hypersegmentation with iron deficiency anemia in one study 81 of children with iron deficiency had hypersegmented neutrophils vs 9 of controls the mechanism for hypersegmentation in iron deficiency is not yet clear but has been suggested to be concurrent iron and vitamin deficiency one of the earliest notable changes in the peripheral blood in megaloblastic processes is the appearance of hypersegmented neutrophils because of the short life span of neutrophils these abnormal hypersegmented neutrophils characteristically appear even before the onset of anemia in megaloblastic processes such neutrophils are less often seen in the other classes of anemia which together are far more common than megaloblastic types of anemia however as noted the use of hypersegmented neutrophils to diagnose type of anemia is limited by the fact that different types of nutrient deficiency anemia may coexist note that pernicious anemia is a type of megaloblastic anemia and as such is expected to show hypersegmented neutrophils
hypersensitivity also called hypersensitivity reaction or intolerance is a set of undesirable reactions produced by the normal immune system including allergies and autoimmunity they are usually referred to as an over reaction of the immune system and these reactions may be damaging uncomfortable or occasionally fatal hypersensitivity reactions require a pre sensitized immune state of the host they are classified in four groups after the proposal of p g h gell and robin coombs in 1963
hypersensitivity pneumonitis hp also called allergic alveolitis or extrinsic allergic alveolitis eaa is an inflammation of the alveoli within the lung caused by hypersensitivity to inhaled organic dusts sufferers are commonly exposed to the dust by their occupation or hobbies
hypersexuality is a clinical diagnosis used by mental healthcare researchers and providers to describe extremely frequent or suddenly increased sexual urges or sexual activity the terms nymphomania and satyriasis were once used to describe the condition in women and men respectively but are no longer in general medical use although the former is still used colloquially
in the 5 th edition of the diagnostic and statistical manual of mental disorders published in may 2013 hypersomnia appears under sleep wake disorders as hypersomnolence of which there are several subtypes
hypersthenuria is a condition where the osmolality of the urine is elevated it can be associated with diabetes mellitus and is determined by a urine specific gravity of greater than 1 010
hypertelorism is an abnormally increased distance between two organs or bodily parts usually referring to an increased distance between the orbits eyes or orbital hypertelorism in this condition the distance between the inner eye corners as well as the distance between the pupils is greater than normal hypertelorism should not be confused with telecanthus in which the distance between the inner eye corners is increased but that of the outer eye corners remains unchanged therefore the distance between the pupils is normal hypertelorism is a symptom in a variety of syndromes including edwards syndrome trisomy 18 1 q 21 1 duplication syndrome basal cell nevus syndrome digeorge syndrome and loeys dietz syndrome hypertelorism can also be seen in apert syndrome craniofrontonasal dysplasia noonan syndrome neurofibromatosis leopard syndrome crouzon syndrome wolf hirschhorn syndrome andersen – tawil syndrome waardenburg syndrome and cri du chat syndrome along with piebaldism prominent inner third of the eyebrows irises of different color spondyloepiphyseal dysplasia mucopolysaccharide metabolism disorders morquio syndrome hurler s syndrome deafness and also in hypothyroidism some links have been found between hypertelorism and attention deficit hyperactivity disorder
hypertension htn or ht also known as high blood pressure hbp is a long term medical condition in which the blood pressure in the arteries is persistently elevated high blood pressure usually does not cause symptoms long term high blood pressure however is a major risk factor for coronary artery disease stroke heart failure peripheral vascular disease vision loss and chronic kidney disease high blood pressure is classified as either primary essential high blood pressure or secondary high blood pressure about 90 – 95 of cases are primary defined as high blood pressure due to nonspecific lifestyle and genetic factors lifestyle factors that increase the risk include excess salt excess body weight smoking and alcohol the remaining 5 – 10 of cases are categorized as secondary high blood pressure defined as high blood pressure due to an identifiable cause such as chronic kidney disease narrowing of the kidney arteries an endocrine disorder or the use of birth control pills blood pressure is expressed by two measurements the systolic and diastolic pressures which are the maximum and minimum pressures respectively normal blood pressure at rest is within the range of 100 – 140 millimeters mercury mmhg systolic and 60 – 90 mmhg diastolic high blood pressure is present if the resting blood pressure is persistently at or above 140 90 mmhg for most adults different numbers apply to children ambulatory blood pressure monitoring over a 24 hour period appears more accurate than office best blood pressure measurement lifestyle changes and medications can lower blood pressure and decrease the risk of health complications lifestyle changes include weight loss decreased salt intake physical exercise and a healthy diet if lifestyle changes are not sufficient then blood pressure medications are used up to three medications can control blood pressure in 90 of people the treatment of moderately high arterial blood pressure defined as 160 100 mmhg with medications is associated with an improved life expectancy the effect of treatment of blood pressure between 140 90 mmhg and 160 100 mmhg is less clear with some reviews finding benefit and others not finding benefit high blood pressure affects between 16 and 37 of the population globally in 2010 hypertension was believed to have been a factor in 18 9 4 million deaths
a hypertensive emergency systolic over 180 or diastolic over 120 formerly called malignant hypertension is hypertension high blood pressure with acute impairment of one or more organ systems especially the central nervous system cardiovascular system and or the renal system that can result in irreversible organ damage in a hypertensive emergency the blood pressure should be slowly lowered over a period of minutes to hours with an antihypertensive agent
hypertensive encephalopathy is a neurological dysfunction induced by malignant hypertension the term hypertensive encephalopathy was introduced to describe this type of encephalopathy by oppenheimer and fishberg in 1928 it describes cerebral conditions typically reversible caused by sudden and sustained severe elevation of blood pressure hypertensive encephalopathy occurs in eclampsia acute nephritis and crises in essential hypertension symptoms of hypertensive encephalopathy include headache restlessness nausea disturbances of consciousness seizures bleeding in the retina and papilledema focal brain lesions may be associated with specific neurological symptoms these neurological impairments may culminate in a coma the condition is treated by drugs that decrease blood pressure
hypertensive heart disease includes a number of complications of high blood pressure that affect the heart while there are several definitions of hypertensive heart disease in the medical literature the term is most widely used in the context of the international classification of diseases icd coding categories the definition includes heart failure and other cardiac complications of hypertension when a causal relationship between the heart disease and hypertension is stated or implied on the death certificate in 2013 hypertensive heart disease resulted in 1 07 million deaths as compared with 630 000 deaths in 1990 according to icd 10 hypertensive heart disease i 11 and its subcategories hypertensive heart disease with heart failure i 11 0 and hypertensive heart disease without heart failure i 11 9 are distinguished from chronic rheumatic heart diseases i 05 i 09 other forms of heart disease i 30 i 52 and ischemic heart diseases i 20 i 25 however since high blood pressure is a risk factor for atherosclerosis and ischemic heart disease death rates from hypertensive heart disease provide an incomplete measure of the burden of disease due to high blood pressure
hypertensive leukoencephalopathy refers to a degeneration of the white matter of the brain following a sudden increase in blood pressure
hypertensive nephropathy or hypertensive nephrosclerosis or hypertensive kidney disease is a medical condition referring to damage to the kidney due to chronic high blood pressure it should be distinguished from renovascular hypertension i 15 0 which is a form of secondary hypertension in the kidneys as a result of benign arterial hypertension hyaline pink amorphous homogeneous material accumulates in the wall of small arteries and arterioles producing the thickening of their walls and the narrowing of the lumina — arteriolosclerosis consequent ischemia will produce tubular atrophy interstitial fibrosis glomerular alterations smaller glomeruli with different degrees of hyalinization from mild to sclerosis of glomeruli and periglomerular fibrosis in advanced stages kidney failure will occur functional nephrons have dilated tubules often with hyaline casts in the lumens additional complications often associated with hypertensive nephropathy include glomerular damage resulting in protein and blood in the urine
hypertensive retinopathy is damage to the retina and retinal circulation due to high blood pressure i e hypertension
hyperthecosis is hyperplasia of the theca interna of the ovary it is when an area of luteinization occurs along with stromal hyperplasia the luteinized cells produce androgens which may lead to hirsutism and virilization or masculinization
hyperthymesia is the condition of possessing an extremely detailed autobiographical memory people with hyperthymesia remember an abnormally vast number of their life experiences american neurobiologists elizabeth parker larry cahill and james mcgaugh 2006 identified two defining characteristics of hyperthymesia spending an excessive amount of time thinking about one s past and displaying an extraordinary ability to recall specific events from one s past the word hyperthymesia derives from ancient greek hyper excessive and thymesis remembering
hyperthyroidism is the condition that occurs due to excessive production of thyroid hormone by the thyroid gland thyrotoxicosis is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidism some however use the terms interchangeably signs and symptoms vary between people and may include irritability muscle weakness sleeping problems a fast heartbeat heat intolerance diarrhea enlargement of the thyroid and weight loss symptoms are typically less in the old and during pregnancy an uncommon complication is thyroid storm in which an event such as an infection results in worsening symptoms such as confusion and a high temperature and often results in death the opposite is hypothyroidism when the thyroid gland does not make enough thyroid hormone graves disease is the cause of about 50 to 80 of the cases of hyperthyroidism in the united states other causes include multinodular goiter toxic adenoma inflammation of the thyroid eating too much iodine and too much synthetic thyroid hormone a less common cause is a pituitary adenoma the diagnosis may be suspected based on signs and symptoms and then confirmed with blood tests typically blood tests show a low thyroid stimulating hormone tsh and raised t 3 or t 4 radioiodine uptake by the thyroid thyroid scan and tsi antibodies may help determine the cause treatment depends partly on the cause and severity of disease there are three main treatment options radioiodine therapy medications and thyroid surgery radioiodine therapy involves taking iodine 131 by mouth which is then concentrated in and destroys the thyroid over weeks to months the resulting hypothyroidism is treated with synthetic thyroid hormone medications such as beta blockers may control the symptoms and anti thyroid medications such as methimazole may temporarily help people while other treatments are having effect surgery to remove the thyroid is another option this may be used in those with very large thyroids or when cancer is a concern in the united states hyperthyroidism affects about 1 2 of the population it occurs between two and ten times more often in women onset is commonly between 20 and 50 years of age overall the disease is more common in those over the age of 60 years
hyperthyroxinemia or hyperthyroxinaemia is a thyroid disease where the serum levels of thyroxine are higher than expected the term is sometimes used to refer to hyperthyroidism but hyperthyroidism is a more general term types include familial dysalbuminemic hyperthyroxinemia familial euthyroid hyperthyroxinemia thyroid hormone resistance syndrome
hypertonia is a term sometimes used synonymously with spasticity in the literature surrounding damage to the central nervous system namely upper motor neuron lesions impaired ability of damaged motor neurons to regulate descending pathways gives rise to disordered spinal reflexes increased excitability of muscle spindles and decreased synaptic inhibition these consequences result in abnormally increased muscle tone of symptomatic muscles some authors suggest that the current definition for spasticity the velocity dependent over activity of the stretch reflex is not sufficient as it fails to take into account patients exhibiting increased muscle tone in the absence of stretch reflex over activity they instead suggest that “ reversible hypertonia ” is more appropriate and represents a treatable condition that is responsive to various therapy modalities like drug and or physical therapy symptoms associated with central nervous systems disorders are classified into positive and negative categories positive symptoms include those that increase muscle activity through hyper excitability of the stretch reflex i e rigidity and spasticity where negative symptoms include those of insufficient muscle activity i e weakness and reduced motor function often the two classifications are thought to be separate entities of a disorder however some authors propose that they may be closely related
a hypertranscendental function or transcendentally transcendental function is an analytic function which is not the solution of an algebraic differential equation with coefficients in z the integers and with algebraic initial conditions all hypertranscendental functions are transcendental functions
hypertrichosis also called ambras syndrome is an abnormal amount of hair growth over the body extensive cases of hypertrichosis have informally been called werewolf syndrome because the appearance is similar to the mythical werewolf the two distinct types of hypertrichosis are generalized hypertrichosis which occurs over the entire body and localized hypertrichosis which is restricted to a certain area hypertrichosis can be either congenital present at birth or acquired later in life the excess growth of hair occurs in areas of the skin with the exception of androgen dependent hair of the pubic area face and axillary regions several circus sideshow performers in the 19 th and early 20 th centuries such as julia pastrana had hypertrichosis many of them worked as freaks and were promoted as having distinct human and animal traits
hypertrichosis cubiti also known as hairy elbow syndrome is a cutaneous condition characterized by multiple terminal hairs on both elbows in children
hypertrichosis simplex of the scalp is a cutaneous condition caused by defects in the corneodesmosin protein
hypertriglyceridemia denotes high hyper blood levels emia of triglycerides the most abundant fatty molecule in most organisms elevated levels of triglycerides are associated with atherosclerosis even in the absence of hypercholesterolemia high cholesterol levels and predispose to cardiovascular disease very high triglyceride levels also increase the risk of acute pancreatitis hypertriglyceridemia itself is usually symptomless although high levels may be associated with skin lesions known as xanthomas the diagnosis is made on blood tests often performed as part of screening once diagnosed other blood tests are usually required to determine whether the raised triglyceride level is caused by other underlying disorders secondary hypertriglyceridemia or whether no such underlying cause exists primary hypertriglyceridaemia there is a hereditary predisposition to both primary and secondary hypertriglyceridemia weight loss and dietary modification may improve hypertriglyceridemia the decision to treat hypertriglyceridemia with medication depends on the levels and on the presence of other risk factors for cardiovascular disease very high levels that would increase the risk of pancreatitis is treated with a drug from the fibrate class niacin and omega 3 fatty acids as well as drugs from the statin class may be used in conjunction with statins being the main drug treatment for moderate hypertriglyceridemia where reduction of cardiovascular risk is required
hypertrophic cardiomyopathy hcm is a disease in which a portion of the myocardium heart muscle is enlarged without any obvious cause creating functional impairment of the heart it is the leading cause of sudden death in young athletes the occurrence of hypertrophic cardiomyopathy is a significant cause of sudden cardiac death in any age group and a cause of disabling cardiac symptoms hcm is frequently asymptomatic until sudden cardiac death and for this reason some suggest routinely screening certain populations for this disease a cardiomyopathy is a disease that affects the muscle of the heart with hcm the myocytes cardiac contractile cells in the heart increase in size which results in the thickening of the heart muscle in addition the normal alignment of muscle cells is disrupted a phenomenon known as myocardial disarray hcm also causes disruptions of the electrical functions of the heart hcm is most commonly due to a mutation in one of nine sarcomeric genes that results in a mutated protein in the sarcomere the primary component of the myocyte the muscle cell of the heart these are predominantly single point missense mutations in the genes for beta myosin heavy chain mhc myosin binding protein c cardiac troponint or tropomyosin these mutations cause myofibril and myocyte structural abnormalities and possible deficiencies in force generation while most literature so far focuses on european american and japanese populations hcm appears in all ethnic groups the prevalence of hcm is about 0 2 to 0 5 of the general population
hypertrophic cardiomyopathy or hcm is the leading cause of sudden cardiac death scd in young athletes hcm is frequently asymptomatic until scd and thus its prevention requires screening screening by medical history and physical exam are ineffective indicating heart abnormalities in only 3 of patients who subsequently suffered scd however hcm can be detected with 80 accuracy by echocardiograms which may be combined with pre screening by electrocardiograms ecgs routine cardiac screening of athletes has been implemented in italy since the 1970 s and has resulted in an 89 drop in cases of scd among screened athletes in the united states citing cost concerns the american heart association has consistently opposed such routine screening for rare conditions like hcm the rate of false positive testing is also a significant concern however certain chapters of the american college of cardiology are backing screening models provided by private entities and nonprofit organizations
hypertrophic osteoarthropathy also known as hypertrophic pulmonary osteoarthropathy bamberger marie syndrome or osteoarthropathia hypertrophicans is a medical condition combining clubbing and periostitis of the small hand joints especially the distal interphalangeal joints distal expansion of the long bones as well as painful swollen joints and synovial villous proliferation are often seen the condition may occur alone primary or it may be secondary to diseases like lung cancer it is especially associated with non small cell lung carcinoma these patients often get clubbing and increased bone deposition on long bones their presenting symptoms are sometimes only clubbing and painful ankles hypertrophic osteoarthropathy is one of many distant effect disorders due to cancer with lung cancer being the most common cause but also occurring with ovarian or adrenal malignancies a distant effect disorder or a paraneoplastic syndrome affects distant areas and thus is not related to local compression or obstruction effects from the tumor other paraneoplastic syndromes include hypercalcemia siadh cushing s syndrome and a variety of neurological disorders
hypertrophic osteodystrophy hod is a bone disease that occurs in fast growing large and giant breed dogs the disorder is sometimes referred to as metaphyseal osteopathy and typically first presents between the ages of 2 and 7 months hod is characterized by decreased blood flow to the metaphysis the part of the bone adjacent to the joint leading to a failure of ossification bone formation and necrosis and inflammation of cancellous bone the disease is usually bilateral in the limb bones especially the distal radius ulna and tibia the weimaraner irish setter boxer german shepherd and great dane breeds are heavily represented in case reports of hod in the veterinary literature but the severity of symptoms and possible etiology may be different across the breeds for example familial clustering of the disease has been documented in the weimaraner but not in other breeds the disease in the weimaraner and irish setter can be particularly severe with significant mortality observed in untreated dogs the classical age of onset is typically 8 to 16 weeks of age with males and females equally affected
hypertrophic osteopathy is a bone disease secondary to cancer in the lungs
a hypertrophic scar is a cutaneous condition characterized by deposits of excessive amounts of collagen which gives rise to a raised scar but not to the degree observed with keloids like keloids they form most often at the sites of pimples body piercings cuts and burns they often contain nerves and blood vessels they generally develop after thermal or traumatic injury that involves the deep layers of the dermis and express high levels of tgf β also mechanical tension on a wound has been identified as a leading cause for hypertrophic scar formation when a normal wound heals the body produces new collagen fibers at a rate which balances the breakdown of old collagen hypertrophic scars are red and thick and may be itchy or painful they do not extend beyond the boundary of the original wound but may continue to thicken for up to six months they usually improve over one or two years but may cause distress due to their appearance or the intensity of the itching they can also restrict movement if they are located close to a joint some people have an inherited tendency to this type of scarring for example those with ehlers danlos syndrome classic type it is not possible to completely prevent hypertrophic scars so those with a history them should inform their doctor or surgeon if they need surgery scar therapies may speed up the process of change from a hypertrophic scar to a flatter paler one
hypertrophy ipa haɪˈpɝːtrəfi from greek ὑπέρ excess τροφή nourishment is the increase in the volume of an organ or tissue due to the enlargement of its component cells it is distinguished from hyperplasia in which the cells remain approximately the same size but increase in number although hypertrophy and hyperplasia are two distinct processes they frequently occur together such as in the case of the hormonally induced proliferation and enlargement of the cells of the uterus during pregnancy eccentric hypertrophy is a type of hypertrophy where the walls and chamber of a hollow organ undergo growth in which the overall size and volume are enlarged it is applied especially to the left ventricle of heart sarcomeres are added in series as for example in dilated cardiomyopathy in contrast to hypertrophic cardiomyopathy a type of concentric hypertrophy where sarcomeres are added in parallel
hypertropia is a condition of misalignment of the eyes strabismus whereby the visual axis of one eye is higher than the fellow fixating eye hypotropia is the similar condition focus being on the eye with the visual axis lower than the fellow fixating eye dissociated vertical deviation is a special type of hypertropia leading to slow upward drift of one or rarely both eyes usually when the patient is inattentive
hypertryptophanemia also called familial hypertryptophanemia is a rare autosomal recessive metabolic disorder that results in a massive buildup of the amino acid tryptophan in the blood with associated symptoms and tryptophanuria uria denotes in the urine elevated levels of tryptophan are also seen in hartnup disease a disorder of amino acid transport however the increase of tryptophan in that disorder is negligible when compared to that of hypertryptophanemia
hyperuricemia is an abnormally high level of uric acid in the blood in the ph conditions of body fluid uric acid exists largely as urate the ion form the amount of urate in the body depends on the balance between the amount of purines eaten in food the amount of urate synthesised within the body e g through cell turnover and the amount of urate that is excreted in urine or through the gastrointestinal tract in humans the upper end of the normal range is 360 µmol l 6 mg dl for women and 400 µmol l 6 8 mg dl for men
hyperuricosuria is a medical term referring to the presence of excessive amounts of uric acid in the urine for men this is at a rate greater than 800 mg day and for women 750 mg day notable direct causes of hyperuricosuria are dissolution of uric acid crystals in the kidneys or urinary bladder and hyperuricemia notable indirect causes include uricosuric drugs rapid breakdown of bodily tissues containing large quantities of dna and rna and a diet high in purine drugs that may contribute to the cure or ameliorationof hyperuricosuria include allopurinol and uricase hyperuricosuria may be a medical sign of gout very common kidney stones of uric acid uric acid nephrolithiasis acute uric acid nephropathy acute renal failure tumor lysis syndrome fanconi syndrome dent s disease very rare
hypervalinemia also called valinemia or valine transaminase deficiency is a rare autosomal recessive metabolic disorder in which urinary and serum levels of the branched chain amino acid valine are elevated without related elevation of the branched chain amino acids leucine and isoleucine it is caused by a deficiency of the enzyme valine transaminase
hyperventilation syndrome hvs also chronic hyperventilation syndrome chvs and dysfunctional breathing hyperventilation syndrome is a respiratory disorder psychologically or physiologically based involving breathing too deeply or too rapidly hyperventilation hvs may present with chest pain and a tingling sensation in the fingertips and around the mouth paresthesia and may accompany a panic attack people with hvs may feel that they cannot get enough air in reality they have about the same oxygenation in the arterial blood normal values are about 98 for hemoglobin saturation and too little carbon dioxide hypocapnia in their blood and other tissues while oxygen is abundant in the bloodstream hvs reduces effective delivery of that oxygen to vital organs due to low co 2 induced vasoconstriction and the suppressed bohr effect the hyperventilation is self promulgating as rapid breathing causes carbon dioxide levels to fall below healthy levels and respiratory alkalosis high blood ph develops this makes the symptoms worse which causes the person to try breathing even faster which further exacerbates the problem the respiratory alkalosis leads to changes in the way the nervous system fires and leads to the paresthesia dizziness and perceptual changes that often accompany this condition other mechanisms may also be at work and some people are physiologically more susceptible to this phenomenon than others
hyperviscosity syndrome is a group of symptoms triggered by increase in the viscosity of the blood symptoms of high blood viscosity include spontaneous bleeding from mucous membranes visual disturbances due to retinopathy and neurologic symptoms ranging from headache and vertigo to seizures and coma hyperviscosity occurs from pathologic changes of either cellular or protein fractions of the blood such as is found in polycythemias multiple myeloma particularly iga and igg 3 leukemia monoclonal gammopathies such as waldenström macroglobulinemia sickle cell anemia and sepsis types of hyperviscosity syndromes vary by pathology including serum hyperviscosity which may cause neurologic or ocular disorders polycythemic hyperviscosity which results in reduced blood flow or capillary perfusion and increased organ congestion and syndromes of hyperviscosity caused by reduced deformability of red blood cells often evident in sickle cell anemia
hypervitaminosis refers to a condition of abnormally high storage levels of vitamins which can lead to toxic symptoms the medical names of the different conditions are derived from the vitamin involved an excess of vitamin a for example is called hypervitaminosis a hypervitaminosis primarily affects the fat soluble vitamins as these are stored by the body for longer period than the water soluble vitamins however avoiding excesses of both classes of vitamins can make the condition hard to get generally toxic levels of vitamins stem from high supplement intake and not from dietary sources toxicities of fat soluble vitamins can also be caused by a large intake of highly fortified foods but foods rarely deliver dangerous levels of fat soluble vitamins the dietary reference intake recommendations from the united states department of agriculture define a tolerable upper intake level for most vitamins high dosage vitamin a high dosage slow release vitamin b 3 and very high dosage vitamin b 6 alone i e without vitamin b complex are sometimes associated with vitamin side effects that usually rapidly cease with supplement reduction or cessation
hypervitaminosis a refers to the toxic effects of ingesting too much preformed vitamin a symptoms arise as a result of altered bone metabolism and altered metabolism of other fat soluble vitamins hypervitaminosis a is believed to have occurred in early humans and the problem has persisted throughout human history toxicity results from ingesting too much preformed vitamin a from foods such as fish or animal liver supplements or prescription medications and can be prevented by ingesting no more than the recommended daily amount diagnosis can be difficult as serum retinol is not sensitive to toxic levels of vitamin a but there are effective tests available hypervitaminosis a is usually treated by stopping intake of the offending food s supplement s or medication most people make a full recovery high intake of provitamin carotenoids such as beta carotene from vegetables and fruits does not cause hypervitaminosis a as conversion from carotenoids to the active form of vitamin a is regulated by the body to maintain an optimum level of the vitamin carotenoids themselves cannot produce toxicity
hypervitaminosis d is a state of vitamin d toxicity the normal range for blood concentration is 30 0 to 74 0 nanograms per milliliter ng ml
hypervitaminosis e is a state of vitamin e toxicity since vitamin e can act as an anticoagulant and may increase the risk of bleeding problems many agencies have set a tolerable upper intake levels ul for vitamin e at 1 000 mg 1 500 iu per day this ul was established due to an increased incidence of hemorrhaging with higher doses of supplemental vitamin e doses of vitamin e above the ul can also magnify the antiplatelet effects of certain drugs such as anti coagulant medications and aspirin which can cause life threatening symptoms in ill patients hypervitaminosis e may also counteract vitamin k leading to a vitamin k deficiency
hypervolemia or fluid overload is the medical condition where there is too much fluid in the blood the opposite condition is hypovolemia which is too little fluid volume in the blood fluid volume excess in the intravascular compartment occurs due to an increase in total body sodium content and a consequent increase in extracellular body water the mechanism usually stems from compromised regulatory mechanisms for sodium handling as seen in congestive heart failure chf kidney failure and liver failure it may also be caused by excessive intake of sodium from foods intravenous iv solutions and blood transfusions medications or diagnostic contrast dyes treatment typically includes administration of diuretics and restriction of the intake of water fluids sodium and salt
hyphema or hyphaema see spelling differences is blood in the front anterior chamber of the eye it may appear as a reddish tinge or it may appear as a small pool of blood at the bottom of the iris or in the cornea
hypnic headaches are benign primary headaches that affect the elderly with the average age of onset being 63 ± 11 years they are moderate throbbing bilateral or unilateral headaches that wake the sufferer from sleep once or multiple times a night they typically begin a few hours after sleep begins and can last from 15 – 180 min there is normally no nausea photophobia phonophobia or autonomic symptoms associated with the headache they commonly occur at the same time every night possibly linking the headaches with circadian rhythm but polysomnography has recently revealed that the onset of hypnic headaches may be associated with rem sleep lithium carbonate 200 – 600 mg at bedtime is an effective treatment for most patients but for those that can not tolerate lithium verapamil indomethacin or methylsergilide may be tried two patients have also responded to flunarizine 5 mg it has also been shown that 1 – 2 cups of coffee or 100 – 200 mg of caffeine before bed can prevent hypnic headaches for diagnosis of hypnic headache syndrome headaches should occur at least 15 times per month for at least one month included in the differential diagnosis of a new onset nighttime headaches in the elderly is drug withdrawal temporal arteritis sleep apnea oxygen desaturated pheochromocytoma intracranial causes primary and secondary neoplasms communicating hydrocephalus subdural hematoma vascular lesions migraines cluster headaches chronic paroxysmal hemicrania and hypnic headache all other causes must be ruled out before the diagnosis of hypnic headache can be made
a hypnozygote is a resting cyst resulting from sexual fusion it is commonly thick walled a synonym of zygotic cyst
hypoactive sexual desire disorder hsdd or inhibited sexual desire isd is considered a sexual dysfunction and is characterized as a lack or absence of sexual fantasies and desire for sexual activity as judged by a clinician for this to be regarded as a disorder it must cause marked distress or interpersonal difficulties and not be better accounted for by another mental disorder a drug legal or illegal or some other medical condition a person with isd will not start or respond to their partner s desire for sexual activity other terms used to describe the phenomenon include sexual aversion and sexual apathy hsdd was listed under the sexual and gender identity disorders of the dsm iv in the dsm 5 it was split into male hypoactive sexual desire disorder and female sexual interest arousal disorder it was first included in the dsm iii under the name inhibited sexual desire disorder but the name was changed in the dsm iii r there are various subtypes hsdd can be general general lack of sexual desire or situational still has sexual desire but lacks sexual desire for current partner and it can be acquired hsdd started after a period of normal sexual functioning or lifelong the person has always had no low sexual desire hsdd has garnered much criticism primarily by asexual activists they point out that hsdd puts asexuality in the same position homosexuality was from 1974 1987 back then the dsm recognised ego dystonic homosexuality as a disorder defined as having sexual interest in the same sex and it causing distress despite the dsm itself officially recognizing this as unnecessarily pathologizing homosexuality and removing it as a disorder in 1987
hypoalbuminemia or hypoalbuminaemia is a medical sign in which the level of albumin in the blood is abnormally low it is a type of hypoproteinemia albumin is a major protein in the human body making up about 55 60 of total human plasma protein by mass many hormones drugs and other molecules are mostly bound to albumin in the bloodstream and must be released before becoming biologically active for example calcium binds to albumin and hypoalbuminemia leads to an increase in free ionized calcium albumin is synthesized in the liver and low serum albumin may be indicative of liver failure or diseases such as cirrhosis or chronic hepatitis hypoalbuminemia can also present as part of the nephrotic syndrome in which protein is lost in the urine due to kidney damage low albumin levels can be an indicator of chronic malnutrition or protein losing enteropathy hypoalbuminemia may cause generalized edema swelling via a decrease in oncotic pressure the serum albumin level is part of a standard panel of liver function tests levels below 3 5 grams per deciliter are generally considered low a low serum anion gap is frequently caused by hypoalbuminemia
in medicine endocrinology hypoaldosteronism refers to decreased levels of the hormone aldosterone isolated hypoaldosteronism is the condition of having lowered aldosterone without corresponding changes in cortisol the two hormones are both produced by the adrenals
hypoalphalipoproteinemia is a high density lipoprotein deficiency inherited in an autosomal dominant manner it can be associated with ldl receptor associated regions and genes include niacin is sometimes prescribed to raise hdl levels
hypobetalipoproteinemia is a disorder consisting of low levels of ldl cholesterol or apolipoprotein b below the 5 th percentile the patient can have hypobetalipoproteinemia and simultaneously have high levels of hdl cholesterol notably in people who do not have the genetic disorder hypobetalipoproteinemia a low cholesterol level may be a marker for poor nutrition wasting disease cancer hyperthyroidism and liver disease
hypocalcaemia also spelled hypocalcemia is low calcium levels in the blood serum the normal range is 2 1 – 2 6 mmol l 8 8 – 10 7 mg dl 4 3 – 5 2 meq l with levels less than 2 1 mmol l defined as hypocalcemia mildly low levels that develop slowly often have no symptoms otherwise symptoms may include numbness muscle spasms seizures confusion or cardiac arrest common causes include hypoparathyroidism and vitamin d deficiency others causes include kidney failure pancreatitis calcium channel blocker overdose rhabdomyolysis tumor lysis syndrome and medications such as bisphosphonates diagnosis should generally be confirmed with a corrected calcium or ionized calcium level specific changes may be seen on an electrocardiogram ecg initial treatment for severe disease is with intravenous calcium chloride and possibly magnesium sulfate other treatments may include vitamin d magnesium and calcium supplements if due to hypoparathyroidism hydrochlorothiazide phosphate binders and a low salt diet may also be recommended about 18 of people who are in hospital have hypocalcemia
hypocapnia or hypocapnea also known as hypocarbia sometimes incorrectly called acapnia is a state of reduced carbon dioxide in the blood hypocapnia usually results from deep or rapid breathing known as hyperventilation hypocapnia is the opposite of hypercapnia
hypocementosis is a reduction in the amount of cementum on a tooth root it is a feature of conditions such as cleidocranial dysplasia and hypophosphatasia
hypochloremia or hypochloraemia is an electrolyte disturbance in which there is an abnormally low level of the chloride ion in the blood the normal serum range for chloride is 97 to 107 meq l it rarely occurs in the absence of other abnormalities its sometimes associated with hypoventilation it can be associated with chronic respiratory acidosis if it occurs together with metabolic alkalosis decreased blood acidity it is often due to vomiting it is usually the result of hyponatremia or elevated bicarbonate concentration it occurs in cystic fibrosis
hypocholesterolemia is the presence of abnormally low hypo levels of cholesterol in the blood emia although the presence of high total cholesterol hyper cholesterolemia correlates with cardiovascular disease a defect in the body s production of cholesterol can lead to adverse consequences as well cholesterol is an essential component of mammalian cell membranes and is required to establish proper membrane permeability and fluidity it is not clear if a lower than average cholesterol level is directly harmful it is often encountered in particular illnesses
hypochondriasis also known as hypochondria health anxiety or illness anxiety disorder refers to worry about having a serious illness this debilitating condition is the result of an inaccurate perception of the condition of body or mind despite the absence of an actual medical condition an individual suffering from hypochondriasis is known as a hypochondriac hypochondriacs become unduly alarmed about any physical or psychological symptoms they detect no matter how minor the symptom may be and are convinced that they have or are about to be diagnosed with a serious illness often hypochondria persists even after a physician has evaluated a person and reassured them that their concerns about symptoms do not have an underlying medical basis or if there is a medical illness their concerns are far in excess of what is appropriate for the level of disease many hypochondriacs focus on a particular symptom as the catalyst of their worrying such as gastro intestinal problems palpitations or muscle fatigue to qualify for the diagnosis of hypochondria the symptoms must have been experienced for at least 6 months the dsm iv tr defines this disorder hypochondriasis as a somatoform disorder and one study has shown it to affect about 3 of the visitors to primary care settings the newly published dsm 5 replaces the diagnosis of hypochondriasis with the diagnoses of somatic symptom disorder and illness anxiety disorder hypochondria is often characterized by fears that minor bodily or mental symptoms may indicate a serious illness constant self examination and self diagnosis and a preoccupation with one s body many individuals with hypochondriasis express doubt and disbelief in the doctors diagnosis and report that doctors ’ reassurance about an absence of a serious medical condition is unconvincing or short lasting additionally many hypochondriacs experience elevated blood pressure stress and anxiety in the presence of doctors or while occupying a medical facility a condition known as white coat syndrome many hypochondriacs require constant reassurance either from doctors family or friends and the disorder can become a disabling torment for the individual with hypochondriasis as well as his or her family and friends some hypochondriacal individuals completely avoid any reminder of illness whereas others frequently visit medical facilities sometimes obsessively other victims of this disease will never speak about it
hypochondrogenesis is a severe genetic disorder causing malformations of bone growth the condition is characterized by a short body and limbs and abnormal bone formation in the spine and pelvis hypochondrogenesis is a subtype of collagenopathy types ii and xi and is similar to another skeletal disorder achondrogenesis type 2 although the spinal changes seen in hypochondrogenesis tend to be somewhat milder
hypochondroplasia is a developmental disorder caused by an autosomal dominant genetic defect in the fibroblast growth factor receptor 3 gene fgfr 3 that results in a disproportionately short stature micromelia and a head that appears large when compared with the underdeveloped portions of the body it is classified as short limbed dwarfism
in mathematics a hypocontinuous is a condition on bilinear maps of topological vector spaces that is weaker than continuity but stronger than separate continuity
hypocorrection is a linguistic phenomenon which involves the purposeful addition of slang in an attempt to appear less intelligible or soften the description it contrasts with hesitation and modulation because rather than not having the right words to say or choosing to avoid them the speaker uses hypocorrection as a strategy
hypodactylia is the absence or partial absence of the fingers and or toes from birth onward
hypodermyasis is a parasitic infection by the larvae of warble flies most notably hypoderma lineatum and hypoderma bovis these flies mostly infect cattle in the warmer areas of the northern hemisphere humans become hosts when they inadvertently swallow the eggs of those flies
in dentistry hypodontia is the condition at which the patient has missing teeth as a result of the failure of those teeth to develop also called tooth agenesis hypodontia describes a situation where the patient is missing up to five permanent teeth excluding the 3 rd molars missing third molars occur in 9 30 of studied populations in primary dentition the maxilla is more affected with the condition usually involving the maxillary lateral incisor the condition of missing over five six or more permanent teeth excluding 3 rd molars or wisdom teeth has been called oligodontia the condition for missing all teeth either primary and or permanent is called anodontia a similar condition is hyperdontia in which there are more than the usual number of teeth more commonly called supernumerary teeth many other terms to describe a reduction in number of teeth appear in the literature aplasia of teeth congenitally missing teeth absence of teeth agenesis of teeth and lack of teeth
hypoestrogenism or estrogen deficiency refers to a lower than normal level of estrogen the primary sex hormone in women in general lower levels of estrogen may cause differences in the breasts genitals urinary tract and skin hypoestrogenism is most commonly found in women who are postmenopausal have premature ovarian failure or are suffering from amenorrhea however it is also associated with hyperprolactinemia and the use of gonadotropin releasing hormone gnrh analogues in treatment of endometriosis it has also been linked to scoliosis and young women with type 1 diabetes mellitus
hypogammaglobulinemia is a characteristic of common variable immunodeficiency
hypogeusia is a reduced ability to taste things to taste sweet sour bitter or salty substances the complete lack of taste is referred to as ageusia causes of hypogeusia include the chemotherapy drug bleomycin an antitumor antibiotic as well as zinc deficiency
hypoglossia is a short incompletely developed tongue it can occur either as an isolated malformation or in association with other deformities particularly limb defects in a syndrome known as oromandibular limb hypogenesis syndrome
hypoglycemia also known as low blood sugar is when blood sugar decreases to below normal levels this may result in a variety of symptoms including clumsiness trouble talking confusion loss of consciousness seizures or death a feeling of hunger sweating shakiness and weakness may also be present symptoms typically come on quickly the most common cause of hypoglycemia is medications used to treat diabetes mellitus such as insulin and sulfonylureas risk is greater in diabetics who have eaten less than usual exercised more than usual or have drunk alcohol other causes of hypoglycemia include kidney failure certain tumors such as insulinoma liver disease hypothyroidism starvation inborn error of metabolism severe infections reactive hypoglycemia and a number of drugs including alcohol low blood sugar may occur in babies who are otherwise healthy who have not eaten for a few hours the glucose level that defines hypoglycemia is variable in people with diabetes levels below 3 9 mmol l 70 mg dl is diagnostic in adults without diabetes symptoms related to low blood sugar low blood sugar at the time of symptoms and improvement when blood sugar is restored to normal confirm the diagnosis otherwise a level below 2 8 mmol l 50 mg dl after not eating or following exercise may be used in newborns a level below 2 2 mmol l 40 mg dl or less than 3 3 mmol l 60 mg dl if symptoms are present indicates hypoglycemia other tests that may be useful in determining the cause include insulin and c peptide levels in the blood hyperglycemia high blood sugar is the opposite condition among people with diabetes prevention is by matching the foods eaten with the amount of exercise and the medications used when people feel their blood sugar is low testing with a glucose monitor is recommended some people have few initial symptoms of low blood sugar and frequent routine testing in this group is recommended treatment of hypoglycemia is by eating foods high in simple sugars or taking dextrose if a person is not able to take food by mouth an injection of glucagon may help the treatment of hypoglycemia unrelated to diabetes include treating the underlying problem as well and a healthy diet the term hypoglycemia is sometimes incorrectly used to refer to idiopathic postprandial syndrome a controversial condition with similar symptoms that occur following eating but with normal blood sugar levels
hypogonadism means diminished functional activity of the gonads — the testes in males or the ovaries in females — that may result in diminished sex hormone biosynthesis in layman s terms it is sometimes called interrupted stage 1 puberty low androgen e g testosterone levels are referred to as hypoandrogenism and low estrogen e g estradiol as hypoestrogenism and may occur as symptoms of hypogonadism in both sexes but are generally only diagnosed in males and females respectively other hormones produced by the gonads that hypogonadism can decrease include progesterone dhea anti müllerian hormone activin and inhibin spermatogenesis in males and ovulation in females may be impaired by hypogonadism which depending on the degree of severity may result in partial or complete infertility
hypogonadotropic hypogonadism hh also known as secondary or central hypogonadism as well as gonadotropin releasing hormone deficiency or gonadotropin deficiency gd is a condition which is characterized by hypogonadism due to an impaired secretion of gonadotropins including follicle stimulating hormone fsh and luteinizing hormone lh by the pituitary gland in the brain and in turn decreased gonadotropin levels and a resultant lack of sex steroid production
hypohidrosis is diminished sweating in response to appropriate stimuli while hyperhidrosis is a socially troubling but benign condition hypohidrosis can lead to hyperthermia heat exhaustion heat stroke and potentially death an extreme case of hypohydrosis in which there is a complete absence of sweating and the skin is dry is termed anhidrosis
hypohidrotic ectodermal dysplasia also known as anhidrotic ectodermal dysplasia and christ siemens touraine syndrome is one of about 150 types of ectodermal dysplasia in humans before birth these disorders result in the abnormal development of structures including the skin hair nails teeth and sweat glands
hypokalemia also spelled hypokalaemia is a low level of potassium k in the blood serum normal potassium levels are between 3 5 and 5 0 mmol l 3 5 and 5 0 meq l with levels below 3 5 mmol l defined as hypokalemia mildly low levels do not typically cause symptoms symptoms may include feeling tired leg cramps weakness and constipation it increases the risk of an abnormal heart rhythm such as bradycardia and cardiac arrest causes of hypokalemia include diarrhea medications like furosemide and steroids dialysis diabetes insipidus hyperaldosteronism hypomagnesemia and not enough intake in the diet it is classified as severe when levels are less than 2 5 mmol l low levels can also be detected on an electrocardiogram ecg hyperkalemia refers to a high level of potassium in the blood serum the speed at which potassium should be replaced depends on whether or not there are symptoms or ecg changes mildly low levels can be managed with changes in the diet potassium supplements can be either taken by mouth or intravenously if given by intravenous generally less than 20 mmol are given over an hour high concentration solutions 40 mmol l should be given in a central line if possible magnesium replacement may also require replacement hypokalemia is one of the most common water – electrolyte imbalances it affects about 20 of people admitted to hospital the word hypokalemia is from hypo means under kalium meaning potassium and emia means condition of the blood
hypokalemic acidosis is a normal anion gap metabolic acidosis that has various direct and associated symptoms symptoms are associated with hypokalemia instead of hyperkalemia
hypokalemic periodic paralysis hypokpp is a rare autosomal dominant channelopathy characterized by muscle weakness or paralysis with a matching fall in potassium levels in the blood primarily due to defect in a voltage gated calcium channel in individuals with this mutation attacks often begin in adolescence and most commonly occur on awakening or after sleep or rest following strenuous exercise attacks during exercise are rare high carbohydrate meals meals with high sodium content sudden changes in temperature and even excitement noise flashing lights and induced by cold temperatures weakness may be mild and limited to certain muscle groups or more severe full body paralysis attacks may last for a few hours or persist for several days recovery is usually sudden when it occurs due to release of potassium from swollen muscles as they recover some patients may fall into an abortive attack or develop chronic muscle weakness later in life to differentiate it from guillain – barré syndrome deep tendon reflexes are normal and 7 th cranial nerve is spared during an attack reflexes may be decreased or absent some people only develop symptoms of periodic paralysis due to hyperthyroidism overactive thyroid this entity is distinguished with thyroid function tests and the diagnosis is instead called thyrotoxic periodic paralysis
hypokinesia refers to decreased bodily movement one of the two categories of movement disorders hypokinesia is characterized by a partial or complete loss of muscle movement due to a disruption in the basal ganglia patients with hypokinetic disorders like parkinson s disease experience muscle rigidity and an inability to produce movement it is also associated with mental health disorders and prolonged inactivity due to illness amongst other diseases the other category of movement disorder resulting from damage to the basal ganglia hyperkinesia features an exaggeration of unwanted motion like twitching or writhing in huntington s disease or tourette syndrome
hypolipoproteinemia hypolipidemia or hypolipidaemia british english is a form of dyslipidemia that is defined by abnormally lowered levels of any or all lipids and or lipoproteins in the blood it occurs through genetic disease namely hypoalphalipoproteinemia and hypobetalipoproteinemia malnutrition malabsorption wasting disease cancer hyperthyroidism and liver disease
hypomagnesemia also spelled hypomagnesaemia is an electrolyte disturbance in which there is a low level of magnesium in the blood normal magnesium levels are between 1 7 – 2 2 mg dl with levels less than 1 7 mg dl 0 7 mmol l defining hypomagnesemia symptoms include tremor nystagmus seizures and cardiac arrest including torsade de pointes causes include alcoholism starvation diarrhea increased urinary loss and poor absorption from the intestines hypomagnesemia is not necessarily magnesium deficiency hypomagnesemia can be present without magnesium deficiency and vice versa specific electrocardiogram ecg changes may be seen for those with severe disease intravenous magnesium sulfate may be used the prefix hypo means under contrast with hyper meaning over the root magnes refers to magnesium the suffix of the word emia means in the blood
hypomagnesemia with secondary hypocalcemia hsh is an autosomal recessive genetic disorder affecting intestinal magnesium absorption decreased intestinal magnesium reabsorption and the resulting decrease in serum magnesium levels is believed to cause lowered parathyroid hormone pth output by the parathyroid gland this results in decreased pth and decreased serum calcium levels hypocalcemia this manifests in convulsions and spasms in early infancy which if left untreated can lead to mental retardation or death hsh is caused by mutations in the trpm 6 gene
hypomania literally under mania or less than mania is a mood state characterized by persistent disinhibition and pervasive elevated euphoric with or without irritable mood but generally less severe than full mania characteristic behaviors are extremely energetic talkative and confident commonly exhibited with a flight of creative ideas while hypomanic behavior often generates productivity and excitement it can become troublesome if the subject engages in risky or otherwise inadvisable behaviors when manic episodes are staged according to symptomatic severity and associated features hypomania constitutes the first stage or stage i of the syndrome wherein the cardinal features euphoria or heightened irritability pressure of speech and activity increased energy and decreased need for sleep and flight of ideas are most plainly evident
hyponatremia also spelled hyponatraemia is a low sodium level in the blood symptoms can vary from none to severe mild symptoms include a decreased ability to think headaches nausea and poor balance severe symptoms include confusion seizures and coma normal serum sodium levels are 135 145 mmol l 135 145 meq l hyponatremia is generally defined as a serum sodium level of less than 135 mmol l and is considered severe when the level is below 120 mmol l the cause of hyponatremia is typically classified by a person s fluid status into low volume normal volume and high volume low volume hyponatremia can occur from diarrhea vomiting diuretics and sweating normal volume hyponatremia is divided into cases with dilute urine and concentrated urine cases in which the urine is dilute include adrenal insufficiency hypothyroidism and drinking too much water or too much beer cases in which the urine is concentrated include syndrome of inappropriate antidiuretic hormone secretion siadh high volume hyponatremia can occur from heart failure liver failure and kidney failure conditions that can lead to falsely low sodium measurements include high protein levels such as in multiple myeloma high blood fat levels and high blood sugar treatment is based on the underlying cause correcting hyponatremia too quickly can lead to complications rapid partial correction with 3 normal saline is only recommended in those with significant symptoms and occasionally those in whom the condition was of rapid onset low volume hyponatremia is typically treated with intravenous normal saline siadh is typically treated with fluid restriction while high volume hyponatremia is typically treated with both fluid restriction and a diet low in salt correction in those in whom the low levels have been present for more than two days should generally be gradual hyponatremia is one of the most commonly seen water – electrolyte imbalances it occurs in about 20 of those admitted to hospital and 10 of people during or after an endurance sporting event among those in hospital hyponatremia is associated with an increased risk of death the economic costs of hyponatremia are estimated at 2 6 billion in the united states
hypoparathyroidism is decreased function of the parathyroid glands with underproduction of parathyroid hormone this can lead to low levels of calcium in the blood often causing cramping and twitching of muscles or tetany involuntary muscle contraction and several other symptoms the condition can be inherited but it is also encountered after thyroid or parathyroid gland surgery and it can be caused by immune system related damage as well as a number of rarer causes the diagnosis is made with blood tests and other investigations such as genetic testing depending on the results the treatment of hypoparathyroidism is limited by the fact that there is no artificial form of the hormone that can be administered as replacement calcium replacement or vitamin d can ameliorate the symptoms but can increase the risk of kidney stones and chronic kidney disease
hypophalangism is a congenital absence of one or more phalanges bones of the fingers and toes
hypopharyngeal cancer is a disease in which malignant cells grow in the hypopharynx the area where the larynx and esophagus meet it first forms in the outer layer epithelium of the hypopharynx last part of the pharynx which is split into three areas progression of the disease is defined by the spread of cancer into one or more areas and into deeper tissues this type of cancer is rare only about 2 500 cases are seen in the us each year because of this hypopharyngeal cancer is difficult to catch in its earliest stages and has one of the highest mortality rates of any head and neck cancer
hypophosphatasia is a rare and sometimes fatal metabolic bone disease clinical symptoms are heterogeneous ranging from the rapidly fatal perinatal variant with profound skeletal hypomineralization and respiratory compromise to a milder progressive osteomalacia later in life tissue non specific alkaline phosphatase tnsalp deficiency in osteoblasts and chondrocytes impairs bone mineralization leading to rickets or osteomalacia the pathognomonic finding is subnormal serum activity of the tnsalp enzyme which is caused by one of 200 genetic mutations identified to date in the gene encoding tnsalp genetic inheritance is autosomal recessive for the perinatal and infantile forms but either autosomal recessive or autosomal dominant in the milder forms the prevalence of hypophosphatasia is not known one study estimated the live birth incidence of severe forms to be 1 100 000
hypophosphatemia is an electrolyte disturbance in which there is an abnormally low level of phosphate in the blood the condition has many causes but is most commonly seen when malnourished patients especially chronic alcoholics are given large amounts of carbohydrates which creates a high phosphorus demand by cells removing phosphate from the blood refeeding syndrome because a decrease in phosphate in the blood is sometimes associated with an increase in phosphate in the urine the terms hypophosphatemia and phosphaturia are occasionally used interchangeably however this is improper since there exist many causes of hypophosphatemia besides overexcretion and phosphaturia and in fact the most common causes of hypophosphatemia are not associated with phosphaturia
hypopigmentation is the loss of skin color it is caused by melanocyte or melanin depletion or a decrease in the amino acid tyrosine which is used by melanocytes to make melanin
hypopituitarism is the decreased hypo secretion of one or more of the eight hormones normally produced by the pituitary gland at the base of the brain if there is decreased secretion of most pituitary hormones the term panhypopituitarism pan meaning all is used the signs and symptoms of hypopituitarism vary depending on which hormones are undersecreted and on the underlying cause of the abnormality the diagnosis of hypopituitarism is made by blood tests but often specific scans and other investigations are needed to find the underlying cause such as tumors of the pituitary and the ideal treatment most hormones controlled by the secretions of the pituitary can be replaced by tablets or injections hypopituitarism is a rare disease but may be significantly underdiagnosed in people with previous traumatic brain injury the first description of the condition was made in 1914 by the german physician dr morris simmonds
hypoplasia from ancient greek ὑπo hypo under πλάσις plasis formation adjective form hypoplastic is underdevelopment or incomplete development of a tissue or organ although the term is not always used precisely it properly refers to an inadequate or below normal number of cells hypoplasia is similar to aplasia but less severe it is technically not the opposite of hyperplasia too many cells hypoplasia is a congenital condition while hyperplasia generally refers to excessive cell growth later in life atrophy the wasting away of already existing cells is technically the direct opposite of both hyperplasia and hypertrophy hypoplasia can be present in any tissue or organ it is descriptive of many medical conditions including underdevelopment of organs such as breasts during puberty testes in klinefelter s syndrome ovaries in fanconi anemia gonadal dysgenesis trisomy x thymus in digeorge syndrome labia majora in popliteal pterygium syndrome corpus callosum connecting the two sides of the brain in agenesis of the corpus callosum cerebellum caused by mutation in the reelin gene tooth caused by oral pathology such as turner s hypoplasia chambers of the heart in hypoplastic left heart syndrome and hypoplastic right heart syndrome optic nerve in optic nerve hypoplasia sacrum in sacral agenesis facial muscle in asymmetric crying facies thumb from birth lungs often as a result of oligohydramnios during gestation or the existence of congenital diaphragmatic hernia small bowel in coeliac disease fingers and ears in harlequin type ichthyosis mandible in congenital hypothyroidism
hypoplasia of dens is a congenital non formation of the pivot point of the second cervical vertebra which leads to spinal cord damage onset of the condition may occur at any age producing signs ranging from neck pain to quadriplegia hypoplasia of dens affects dogs it is more commonly seen in certain breeds including the chihuahua the papillon the pointer and the yorkshire terrier
hypoplastic left heart syndrome hlhs is a rare congenital heart defect in which the left heart is severely underdeveloped the international working group for mapping and coding of nomenclatures for paediatric and congenital heart disease defined hlhs as a spectrum of cardiac malformations with normally aligned great arteries without a common atrioventricular junction characterized by underdevelopment of the left heart with significant hypoplasia of the left ventricle including atresia stenosis or hypoplasia of the aortic or mitral valve or both valves and hypoplasia of the ascending aorta and aortic arch — tchervenkov et al p 344
hypoplastic maxilla is the name given to the dysfunctional structural condition around which the oral disruption literally pivoted it is associated with crouzon syndrome
hypoplastic right heart syndrome is a congenital heart defect in which the right atrium and right ventricle are underdeveloped this defect causes inadequate blood flow to the lungs and thus a blue or cyanotic infant 3
hypoprolactinemia is a medical condition characterized by a deficiency in the serum levels of the hypothalamic pituitary hormone prolactin
hypoproteinemia or hypoproteinaemia is a condition where there is an abnormally low level of protein in the blood there are several causes and all result in edema once serum protein levels fall below a certain threshold
hypoprothrombinemia is a blood disorder in which a deficiency of prothrombin factor ii results in impaired blood clotting leading to an increased physiological risk for bleeding especially in the gastrointestinal system cranial vault and superficial integumentary system
hyporeflexia is the condition of below normal or absent reflexes areflexia it can be tested for by using a reflex hammer it is the opposite of a condition called hyperreflexia hyporeflexia is generally associated with a lower motor neuron deficit at the alpha motor neurons from the spinal cord to muscle whereas hyperreflexia is often attributed to upper motor neuron lesions along the long motor tracts from the brain the upper motor neurons are thought to be inhibitory of the reflex arc which is formed by sensory neurons from intrafusal fibers of muscles lower motor neurons including alpha and gamma motor fibers and appurtenant interneurons therefore damage to lower motor neurons will subsequently lead to hyporeflexia and or areflexia note that in spinal shock which is commonly seen in transection of the spinal cord spinal cord injury areflexia can occur transiently below the level of the lesion and after a period of time become hyperreflexic hyporeflexia may have other causes including hypothyroidism electrolyte imbalance including excess magnesium drug induced e g the symptoms of benzodiazepine intoxication include confusion slurred speech ataxia drowsiness dyspnea and hyporeflexia
hyposmia is a reduced ability to smell and to detect odors a related condition is anosmia in which no odors can be detected some of the causes of olfaction problems are allergies nasal polyps viral infections and head trauma it is estimated that up to 4 million people in the united states have hyposmia or the related anosmia hyposmia might be a very early sign of parkinson s disease hyposmia is also an early and almost universal finding in alzheimer s disease and dementia with lewy bodies lifelong hyposmia could be caused by kallmann syndrome
hypospadias haɪpoʊˈspeɪdɪəs is a birth defect of the urethra where the urinary opening is not at the usual location on the head of the penis it is the second most common birth abnormality of the male reproductive system affecting approximately 1 of every 250 in approximately 90 of cases the opening meatus is on or near the head of the penis glans referred to as distal hypospadias while the remainder have proximal hypospadias with a meatus near or within the scrotum shiny tissue seen extending from the meatus to the tip of the glans which would have made the urinary channel is referred to as the urethral plate in most cases the foreskin is also underdeveloped and does not wrap completely around the penis leaving the underside of the glans penis uncovered there may also be downward bending of the penis commonly referred to as chordee this is found in 10 of distal hypospadias and 50 of proximal hypospadias at the time of surgery the scrotum may be higher than usual to either side of the penis called penoscrotal transposition adding to the abnormal overall appearance hypospadias is thought to result from failure of the urinary channel to completely tubularize to the end of the penis the cause of hypospadias is not known most often it is the only abnormal finding although in about 10 of cases hypospadias may be part of a syndrome with multiple abnormalities the most common associated defect is an undescended testicle which has been reported in approximately 3 of infants with distal hypospadias and 10 of those having proximal hypospadias the combination of hypospadias and an undescended testicle sometimes indicates a disorder of sexual differentiation and so additional testing may be recommended otherwise no blood tests or x rays are routinely needed in newborns with hypospadias
normal ejaculate when a man is not drained from prior sex and is suitably aroused is around 1 5 6 ml although this varies greatly with mood physical condition and sexual activity of this around 1 by volume is sperm cells hypospermia would only usually be a factor in infertility if the two conditions hypospermia and oligospermia are combined the u s based national institutes of health defines hypospermia as a semen volume lower than 2 ml on at least two semen analyses the presence of high levels of fructose a sugar is normal in the semen and this comes almost entirely from the seminal vesicle the seminal vesicles major contributors to ejaculate volume render semen ph basic thus low fructose may indicate problems in the prostatic pathway while low semen ph may indicate problems related to the seminal vesicles obstruction of the seminal vesicles result in low semen volumes since they normally produce 70 of the seminal plasma
hypot is a mathematical function defined to calculate the length of the hypotenuse of a right angle triangle it was designed to avoid errors arising due to limited precision calculations performed on computers
hypotelorism is a medical condition pertaining to eyes that have an abnormally small distance between them
hypotension is low blood pressure especially in the arteries of the systemic circulation blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood hypotension is generally considered if systolic blood pressure less than 90 millimeters of mercury mm hg or diastolic less than 60 mm hg however in practice blood pressure is considered too low only if noticeable symptoms are present hypotension is the opposite of hypertension which is high blood pressure it is best understood as a physiological state rather than a disease severely low blood pressure can deprive the brain and other vital organs of oxygen and nutrients leading to a life threatening condition called shock though often associated with shock hypotension is not necessarily indicative of it for some people who exercise and are in top physical condition low blood pressure is a sign of good health and fitness for many people excessively low blood pressure can cause dizziness and fainting or indicate serious heart endocrine or neurological disorders
a hypotensive transfusion reaction or htr is a rare condition that presents with low blood pressure associated with administration of blood products the low blood pressure quickly resolves when the transfusion is stopped htrs are caused by the production of bradykinin produced through factor xii activation by negatively charged surfaces such as filters when mechanisms for the degradation of bradykinin are impaired the peptide builds up and causes hypotension angiotensin converting enzyme ace is primarily responsible for its degradation 75 but can be inhibited by administration of blood pressure medications called ace inhibitors polymorphisms in ace or aminopeptidase p app another enzyme responsible for bradykinin degradation 20 may also contribute to htrs
hypothalamic disease is a disorder presenting primarily in the hypothalamus which may be caused by damage resulting from malnutrition including anorexia and bulimia eating disorders genetic disorders radiation surgery head trauma lesion tumour or other physical injury to the hypothalamus the hypothalamus is the control center for several endocrine functions endocrine systems controlled by the hypothalamus are regulated by anti diuretic hormone adh corticotropin releasing hormone gonadotropin releasing hormone growth hormone releasing hormone oxytocin all of which are secreted by the hypothalamus damage to the hypothalamus may impact any of these hormones and the related endocrine systems many of these hypothalamic hormones act on the pituitary gland hypothalamic disease therefore affects the functioning of the pituitary and the target organs controlled by the pituitary including the adrenal glands ovaries and testes and the thyroid gland numerous dysfunctions manifest as a result of hypothalamic disease damage to the hypothalamus may cause disruptions in body temperature regulation growth weight sodium and water balance milk production emotions and sleep cycles hypopituitarism neurogenic diabetes insipidus tertiary hypothyroidism and developmental disorders are examples of precipitating conditions caused by hypothalamic disease
hypothermia is defined as a body core temperature below 35 0 ° c 95 0 ° f symptoms depend on the temperature in mild hypothermia there is shivering and mental confusion in moderate hypothermia shivering stops and confusion increases in severe hypothermia there may be in which a person removes his or her clothing as well as an increased risk of the heart stopping hypothermia has two main types of causes it classically occurs from exposure to extreme cold it may also occur from any condition that decreases heat production or increases heat loss commonly this includes alcohol intoxication but may also include low blood sugar anorexia and advanced age among others body temperature is usually maintained near a constant level of 36 5 – 37 5 ° c 97 7 – 99 5 ° f through thermoregulation efforts to increase body temperature involve shivering increased voluntary activity and putting on warmer clothing hypothermia may be diagnosed based on either a person s symptoms in the presence of risk factors or by measuring a person s core temperature the treatment of mild hypothermia involves warm drinks warm clothing and physical activity in those with moderate hypothermia heating blankets and warmed intravenous fluids are recommended people with moderate or severe hypothermia should be moved gently in severe hypothermia extracorporeal membrane oxygenation ecmo or cardiopulmonary bypass may be useful in those without a pulse cardiopulmonary resuscitation cpr is indicated along with the above measures rewarming is typically continued until a person s temperature is greater than 32 ° c 90 ° f if there is no improvement at this point or the blood potassium level is greater than 12 mmol liter at any time resuscitation may be discontinued hypothermia is the cause of at least 1500 deaths a year in the united states it is more common in older people and males one of the lowest documented body temperatures from which someone with accidental hypothermia has survived is 13 0 ° c 55 4 ° f in a near drowning of a 7 year old girl in sweden survival after more than six hours of cpr has been described in those in whom ecmo or bypass is used survival is around 50 deaths due to hypothermia have played an important role in many wars hyperthermia is the opposite of hypothermia being an increased body temperature due to failed thermoregulation the term is from greek ὑπο meaning under and θερμία meaning heat
hypothyroidism also called underactive thyroid or low thyroid is a common disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormone it can cause a number of symptoms such as poor ability to tolerate cold a feeling of tiredness constipation depression and weight gain occasionally there may be swelling of the front part of the neck due to goitre untreated hypothyroidism during pregnancy can lead to delays in growth and intellectual development in the baby which is called cretinism worldwide too little iodine in the diet is the most common cause of hypothyroidism in countries with enough iodine in the diet the most common cause of hypothyroidism is the autoimmune condition hashimoto s thyroiditis less common causes include previous treatment with radioactive iodine injury to the hypothalamus or the anterior pituitary gland certain medications a lack of a functioning thyroid at birth or previous thyroid surgery the diagnosis of hypothyroidism when suspected can be confirmed with blood tests measuring thyroid stimulating hormone tsh and thyroxine levels prevention at the population level has been with the universal salt iodization hypothyroidism can be treated with levothyroxine the dose is adjusted according to symptoms and normalization of the thyroxine and tsh levels thyroid medication is safe in pregnancy while a certain amount of dietary iodine is important excessive amounts can worsen certain types of hypothyroidism worldwide about one billion people are estimated to be iodine deficient however it is unknown how often this results in hypothyroidism in the united states hypothyroidism occurs in 0 3 – 0 4 of people subclinical hypothyroidism a milder form of hypothyroidism characterized by normal thyroxine levels and an elevated tsh level is thought to occur in 4 3 – 8 5 of people in the united states hypothyroidism is more common in women than men people over the age of 60 are more commonly affected dogs are also known to develop hypothyroidism and in rare cases cats and horses can also have the disorder the word hypothyroidism is from greek hypo meaning reduced thyreos for shield and eidos for form
hypoosmolar hyponatremia is a condition where hyponatremia associated with a low plasma osmolality the term hypotonic hyponatremia is also sometimes used when the plasma osmolarity is low the extracellular fluid volume status may be in one of three states low volume normal volume or high volume
hypotrichosis hypo tricho osis is a condition of abnormal hair patterns predominantly loss or reduction it occurs most frequently by the growth of vellus hair in areas of the body that normally produce terminal hair typically the individual s hair growth is normal after birth but shortly thereafter the hair is shed and replaced with sparse abnormal hair growth the new hair is typically fine short and brittle and may lack pigmentation baldness may be present by the time the subject is 25 years old hypotrichosis is a common feature of hallermann – streiff syndrome as well as others it can also be used to describe the lack of hair growth due to chemotherapy the opposite of hypotrichosis is hypertrichosis where terminal hair thick grows in areas that would otherwise normally have vellus hair thin for example abnormally thick facial hair growth in women
hypotrichosis with juvenile macular dystrophy hjmd or cdh 3 is an extremely rare congenital disease characterized by sparse hair growth hypotrichosis from birth and progressive macular corneal dystrophy
hypotrichosis – acro osteolysis – onychogryphosis – palmoplantar keratoderma – periodontitis syndrome also known as hopp syndrome is a cutaneous condition characterized by a prominent palmoplantar keratoderma
hypotrichosis – lymphedema – telangiectasia syndrome is a congenital syndrome characterized by lymphedema swelling of tissue due to malformation or malfunction of lymphatics the presence of telegiectasias small dilated vessels near the surface of the skin and hypotrichosis or alopecia hair loss lymphedema usually develops in the lower extremities during puberty hair is normal at birth but usually lost during infancy telangiectasias may present on the palms and soles more commonly than on the scalp legs and genitalia the syndrome has been reported in association with both autosomal dominant and autosomal recessive inheritance patterns it is associated with a rare mutation of the transcription factor gene sox 18
hypouricemia is a level of uric acid in blood serum that is below normal in humans the normal range of this blood component has a lower threshold set variously in the range of 2 mg dl to 4 mg dl while the upper threshold is 530 micromol l 6 mg dl for women and 619 micromol l 7 mg dl for men hypouricemia usually is benign and sometimes is a sign of a medical condition
hypovolemia also hypovolaemia or oligemia is a state of decreased blood volume more specifically decrease in volume of blood plasma it is thus the intravascular component of volume contraction or loss of blood volume due to things such as bleeding or dehydration but as it also is the most essential one hypovolemia and volume contraction are sometimes used synonymously hypovolemia is characterized by sodium salt depletion and thus differs from dehydration which is defined as excessive loss of body water
hypoxemia or hypoxaemia in british english is an abnormally low level of oxygen in the blood more specifically it is oxygen deficiency in arterial blood hypoxemia has many causes often respiratory disorders and can cause tissue hypoxia as the blood is not supplying enough oxygen to the body
hypoxia is a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level hypoxia may be classified as either generalized affecting the whole body or local affecting a region of the body although hypoxia is often a pathological condition variations in arterial oxygen concentrations can be part of the normal physiology for example during hypoventilation training or strenuous physical exercise hypoxia differs from hypoxemia and anoxemia in that hypoxia refers to a state in which oxygen supply is insufficient whereas hypoxemia and anoxemia refer specifically to states that have low or zero arterial oxygen supply hypoxia in which there is complete deprivation of oxygen supply is referred to as anoxia generalized hypoxia occurs in healthy people when they ascend to high altitude where it causes altitude sickness leading to potentially fatal complications high altitude pulmonary edema hape and high altitude cerebral edema hace hypoxia also occurs in healthy individuals when breathing mixtures of gases with a low oxygen content e g while diving underwater especially when using closed circuit rebreather systems that control the amount of oxygen in the supplied air a mild and non damaging intermittent hypoxia is used intentionally during altitude trainings to develop an athletic performance adaptation at both the systemic and cellular level hypoxia is also a serious consequence of preterm birth in the neonate the main cause for this is that the lungs of the human fetus are among the last organs to develop during pregnancy to assist the lungs to distribute oxygenated blood throughout the body infants at risk of hypoxia are often placed inside an incubator capable of providing continuous positive airway pressure also known as a humidicrib
hypoxic pulmonary vasoconstriction is a physiological phenomenon in which pulmonary arteries constrict in the presence of hypoxia low oxygen levels without hypercapnia high carbon dioxide levels redirecting blood flow to alveoli with a higher oxygen content the process might at first seem illogical as low oxygen levels should theoretically lead to increased blood flow to the lungs to receive increased gaseous exchange however it is explained by the fact that constriction leads to redistribution of bloodflow to better ventilated areas of the lung which increases the total area involved in gaseous exchange this improves ventilation perfusion ratio and arterial oxygenation but is less helpful in the case of long term whole body hypoxia this is seen in copd at altitude and in heart failure several factors inhibit this process including increased cardiac output hypocapnia hypothermia acidosis alkalosis increased pulmonary vascular resistance inhaled anesthetics calcium channel blockers positive end expiratory pressure peep high frequency ventilation hfv isoproterenol nitric oxide and vasodilators
hypoxic ventilatory response hvr is the increase in ventilation induced by hypoxia it is initially elevated in lowland people who go to high altitude although it reduces significantly over time as people acclimatize hypoxic ventilatory response hvr is a term used in the study of anthropology pertaining to human adaptation and stresses of high altitude
hypsarrhythmia is an abnormal interictal pattern consisting of high amplitude and irregular waves and spikes in a background of chaotic and disorganized activity seen on electroencephalogram eeg and frequently encountered in an infant diagnosed with infantile spasms although it can be found in other conditions in simpler terms it is very chaotic and disorganized brain electrical activity with no recognizable pattern whereas a normal eeg shows clear separation between each signal and visible pattern gibbs and gibbs described hypsarhythmia originally spelled with one r in 1952 as random high voltage waves and spikes these spikes vary from moment to moment both in time and in location at time they appear to be focal and a few seconds later they seem to originate from multiple foci occasionally the spike discharge becomes generalized but it never appears as a rhythmically repetitive and highly organized pattern that could be confused with a discharge of the petit mal or petit mal variant type in most cases of infantile spasms hypsarrhythmia either disappears or improves during a cluster of spasms and or rem sleep hypsarrhythmia rarely persists beyond the age of 24 months
hypsodont is a pattern of dentition with high crowned teeth and enamel extending past the gum line providing extra material for wear and tear some examples of animals with hypsodont dentition are cows and horses all animals that feed on gritty fibrous material the opposite condition is called brachydont
a hypsometric curve is a histogram or cumulative distribution function of elevations in a geographical area differences in hypsometric curves between landscapes arise because the geomorphic processes that shape the landscape may be different when drawn as a 2 dimensional histogram a hypsometric curve displays the elevation on the vertical y axis and area above the corresponding elevation on the horizontal or x axis the curve can also be shown in non dimensional or standardized form by scaling elevation and area by the maximum values the non dimensional hypsometric curve provides an hydrologist or a geomorphologist with a way to assess the similarity of watersheds — and is one of several characteristics used for doing so
hystrix like ichthyosis – deafness syndrome also known as hid syndrome is a cutaneous condition characterized by a keratoderma
hürthle cell adenoma is a rare condition often seen in women between the ages of seventy and eighty years old this adenoma is often characterized by a mass of hürthle cells this mass is mostly benign but may be malignant if the mass is malignant the mass is referred as a follicular thyroid cancer or a hürthle cell carcinoma
the i 40 bridge disaster was a bridge collapse that occurred southeast of webbers falls oklahoma at 7 45 a m on may 26 2002 joe dedmon captain of the towboat robert y love experienced a fainting spell and lost control of the tow this in turn caused the barges he was controlling to collide with a bridge pier the result was a 580 foot 176 78 m section of the interstate 40 bridge plunging into robert s kerr reservoir on the arkansas river fourteen people died and eleven others were injured when several automobiles and tractor trailers fell from the bridge
inclusion cell i cell disease also referred to as mucolipidosis ii ml ii is part of the lysosomal storage disease family and results from a defective phosphotransferase an enzyme of the golgi apparatus this enzyme transfers phosphate to mannose residues on specific proteins and serves as a marker for them to be targeted to lysosomes within the cell without this marker the proteins are instead excreted outside the cell — the default pathway for proteins moving through the golgi apparatus lysosomes cannot function without these proteins which function as catabolic enzymes for the normal breakdown of substances e g oligosaccharides lipids and glycosaminoglycans in various tissues throughout the body i e fibroblasts as a result a buildup of these substances occurs within lysosomes because they cannot be degraded resulting in the characteristic i cells or inclusion cells these cells can be identified under the microscope in addition the defective lysosomal enzymes normally found only within lysosomes are instead found in high concentrations in the blood
in the mathematical subfield of numerical analysis an i spline is a monotone spline function
the interpolated spread or i spread or isprd of a bond is the difference between its yield to maturity and the linearly interpolated yield for the same maturity on an appropriate reference yield curve if the bond is expected to repay some principal before its final maturity then the interpolation may be based on the weighted average life rather than the maturity
in computing iif an abbreviation for immediate if is a function in several editions of the visual basic programming language and coldfusion markup language cfml and on spreadsheets that returns the second or third parameter based on the evaluation of the first parameter it is an example of a conditional expression which is similar to a conditional statement
the lbm file extension is an image file in interchange file format iff structure to store image or palette data most commonly you can find these files in interleaved bitmap ilbm format but some games are using a similar but simpler to use planar bitmap pbm format both formats commonly exist under the lbm file extension occasionally appearing also as bbm extension ilbm and pbm formats are used by games from late 80 s and early 90 s that either originated from amiga platform or had their assets such as graphics done on amiga
ipex immunodysregulation polyendocrinopathy enteropathy x linked syndrome is a rare disease linked to the dysfunction of the transcription factor foxp 3 widely considered to be the master regulator of the regulatory t cell lineage it leads to the dysfunction of regulatory t cells and the subsequent autoimmunity the disorder manifests with autoimmune enteropathy psoriasiform or eczematous dermatitis nail dystrophy autoimmune endocrinopathies overlapping with those seen in apeced syndrome and autoimmune skin conditions such as alopecia universalis and bullous pemphigoid this autoimmunity is called ipex and it is the attack from the body s own immune system against the body s own tissues and organs early age onset of this disease in males causes severe enlargement of the secondary lymphoid organs insulin dependent diabetes eczema food allergies and infections there has been limited success in treating the syndrome by bone marrow transplantation
ipo underpricing is the increase in stock value from the initial offering price to the first day closing price many believe that underpriced ipos leave money on the table for corporations but some believe that underpricing is inevitable investors state that underpricing signals high interest to the market which increases the demand on the other hand overpriced stocks will drop long term as the price stabilizes so underpricing may keep the issuers safe from investor litigation
in computational complexity theory the class ip which stands for interactive polynomial time is the class of problems solvable by an interactive proof system the concept of an interactive proof system was first introduced by shafi goldwasser silvio micali and charles rackoff in 1985 an interactive proof system consists of two machines a prover p which presents a proof that a given string n is a member of some language and a verifier v that checks that the presented proof is correct the prover is assumed to be infinite in computation and storage while the verifier is a probabilistic polynomial time machine with access to a random bit string whose length is polynomial on the size of n these two machines exchange a polynomial number p n of messages and once the interaction is completed the verifier must decide whether or not n is in the language with only a 1 3 chance of error so any language in bpp is in ip since then the verifier could simply ignore the prover and make the decision on its own
ip shuffling is the ability to set up a call path between two ip endpoints by rerouting the voice channel away from the usual tdm bus connection and creating a direct ip to ip connection ip shuffling saves resources like tdm bus time slots and media channels and improve voice quality by eliminating unnecessary codec conversions to enable ip shuffling there must be at least one common codec between the two point to point ip endpoints ip shuffling can take place not only inside of a system but also between multiple systems this ability is particularly useful in a multi site call center environment where customer calls can be transferred from one person to another multiple times within the same transaction ip shuffling will tear down each call leg and re establish a point to point connection with the new calling party each time the call gets transferred saving valuable system resources
iq classification is the practice by iq test publishers of labeling iq score ranges with category names such as superior or average there are several publishers of tests of cognitive abilities no two publishers use exactly the same classification labels which have changed from time to time since the beginning of intelligence testing in the early twentieth century iq scores have been derived by two different methods since the advent of cognitive ability tests the first method historically was the ratio iq based on estimating a mental age of the test taker rounded to a specified number of years and months which was then divided by the test taker s chronological age rounded to a specified number of years and months for example a mental age score of thirteen years and zero months for a test taker with the chronological age ten years and zero months results in a quotient of 1 3 after doing the division the division result was then multiplied by 100 so that scores could be reported without decimal points thus the score in the example would be reported as iq 130 the current scoring method for all iq tests is the deviation iq in this method an iq score of 100 means that the test taker s performance on the test is at the median level of performance in the sample of test takers of about the same age used to norm the test an iq score of 115 means performance one standard deviation above the median a score of 85 performance one standard deviation below the median and so on lewis terman and other early developers of iq tests noticed that most child iq scores come out to approximately the same number by either procedure deviation iqs are now used for standard scoring of all iq tests in large part because they allow a consistent definition of iq for both children and adults by the current deviation iq definition of iq test standard scores about two thirds of all test takers obtain scores from 85 to 115 and about 5 percent of the population scores above 125 historically even before iq tests were invented there were attempts to classify people into intelligence categories by observing their behavior in daily life those other forms of behavioral observation are still important for validating classifications based primarily on iq test scores both intelligence classification by observation of behavior outside the testing room and classification by iq testing depend on the definition of intelligence used in a particular case and on the reliability and error of estimation in the classification procedure all iq tests show variation in scores even when the same person takes the same test over and over again iq scores also differ for a test taker taking tests from more than one publisher at the same age the various test publishers do not use uniform names or definitions for iq score classifications all these issues must be kept in mind when interpreting an individual s iq scores because they all can result in different iq classifications for the same person at different times
iatrogenic calcinosis cutis is a cutaneous condition characterized by calcification of the skin resulting from the deposition of calcium and phosphorus introduced by a medical procedure either inadvertently or as a specific therapy
ice ice is a disease condition of seaweed ice ice is caused when changes in salinity ocean temperature and light intensity cause stress to seaweeds making them produce a moist organic substance that attracts bacteria in the water and induces the characteristic whitening and hardening of the seaweed s tissues bacteria involved include those in the vibrio aeromonas and cytophaga flavobacteria complexes the bacteria lyse epidermal cells and chloroplasts turning the seaweed tissue white the disease is known from seaweeds including kappaphycus alvarezii and eucheuma denticulatum economically important sources of carrageenan in countries where seaweed is harvested as a crop ice ice can wreak havoc on yields zamboanga philippines had an outbreak of ice ice in 2004 and bali indonesia experienced an outbreak in 2009 a rise in surface sea temperatures of 2 3 degrees celsius can trigger ice ice outbreaks
an ice disc ice circle or ice pan is a natural phenomenon that occurs in slow moving water in cold climates ice circles are thin and circular slabs of ice that rotate slowly in the water it is believed that they form in eddy currents ice discs have most frequently been observed in scandinavia and north america but they are occasionally recorded as far south as england and wales an ice disc was observed in wales in december 2008 and another was reported in england in january 2009 an ice disc was observed on the sheyenne river in north dakota in december 2013 an ice circle of approximately 50 ft in diameter was observed and photographed in lake katrine new york on the esopus creek around january 23 2014 in idaho extreme weather led to a rare sighting of an ice disk on the snake river on january 22 2014 an unusual natural phenomenon ice disks occur in slow moving water in cold climates and can vary in size with circles more than 15 metres 49 ft in diameter observed
a brain freeze also known as ice cream headache cold stimulus headache trigeminal headache or its given scientific name sphenopalatine ganglioneuralgia meaning nerve pain of the sphenopalatine ganglion is a form of brief pain or headache commonly associated with consumption particularly quick consumption of cold beverages or foods such as ice cream and ice pops it is caused by having something cold touch the roof of the mouth palate and is believed to result from a nerve response causing rapid constriction and swelling of blood vessels or a referring of pain from the roof of the mouth to the head the rate of intake for cold foods has been studied as a contributing factor ice cream headache is distinct from dentin hypersensitivity a type of pain that can occur under similar circumstances the term ice cream headache has been in use since at least 31 january 1937 contained in a journal entry by rebecca timbres published in the 1939 book we didn t ask utopia a quaker family in soviet russia
ice diving is a type of penetration diving where the dive takes place under ice because diving under ice places the diver in an overhead environment typically with only a single entry exit point it is considered an advanced type of diving requiring special training although whether it constitutes technical diving is part of a wider debate within the diving community ice divers are generally tethered for safety this means that the diver wears a special harness under the scuba unit a line is secured to this harness and the other end of the line is secured above the surface by one of a number of methods the diver also can use a weight harness integrated weight buoyancy control device or a weight belt with two buckles on it so the weights can not be accidentally released which would cause a run away ascent into the ice sheet ice diving is a team diving activity because the divers line requires a line tender this person is responsible for paying out and taking in line so that the diver does not get tangled communication to the diver or to the surface is accomplished by pulling on the line each series of tugs means a different thing there is a diver suited up and ready to enter the water at a moment s notice this diver is a safety diver and has his own tender his purpose is to assist the primary diver in the event of a problem divers who do not use a tether require extra training and full redundant scuba systems polar diving experience has shown that buoyancy control is the critical skill affecting safety
ice segregation is the geological phenomenon produced by the formation of ice lenses which induce erosion when moisture diffused within soil or rock accumulates in a localized zone the ice initially accumulates within small collocated pores or pre existing cracks and as long as the conditions remain favorable continues to collect in the ice layer or ice lens wedging the soil or rock apart ice lenses grow parallel to the surface and several centimeters to several decimeters inches to feet deep in the soil or rock studies between 1990 and present have demonstrated that rock fracture by ice segregation i e the fracture of intact rock by ice lenses that grow by drawing water from their surroundings during periods of sustained subfreezing temperatures is a more effective weathering process than the freeze thaw process which older texts proposed ice lenses play the key role in fracture of bedrock and frost induced heaving of soils which are fundamental to weathering in cold regions frost heaving creates debris and dramatically shapes landscapes into complex patterns rock fracture in periglacial regions alpine subpolar and polar has often been attributed to the freezing and volumetric expansion of water trapped within pores and cracks however the majority of frost heaving and of bedrock fracture results instead from ice segregation in ice lenses in the near surface frozen regions ice segregation results in rock fracture and frost heave
icephobicity from ice and greek φόβος phobos fear is the ability of a solid surface to repel ice or prevent ice formation due to a certain topographical structure of the surface the word “ icephobic ” was used for the first time at least in 1950 however the progress in micropatterned surfaces resulted in growing interest towards the icephobicty since the 2000 s as a keyword the term “ icephobic ” was used for the first time in scientific literature by kulinich farzaneh in 2004 as well as in some industrial reports and by nasa
ichthyophthirius multifiliis commonly known as freshwater white spot disease freshwater ich or freshwater ick is a common disease of freshwater fish it is caused by the protozoan ichthyopthirius ich is one of the most common and persistent diseases in fish the protozoan is an ectoparasite white nodules that look like white grains of salt or sugar of up to 1 mm appear on the body fins and gills each white spot is an encysted parasite it is easily introduced into a fish pond or home aquarium by new fish or equipment which has been moved from one fish holding unit to another when the organism gets into a large fish culture facility it is difficult to control due to its fast reproductive cycle and its unique life stages if not controlled there is a 100 mortality rate of fish with careful treatment the disease can be controlled but the cost is high in terms of lost fish labor and cost of chemicals whitespot is very damaging to the gills and skin in heavily infected fish it can cause a rapid deterioration of condition considerable distress and death infected fish have small white spots on the skin and gills fig 2 and fig 3 and produce excess mucus due to irritation whitespot causes most damage when entering and leaving the tissues of the fish this can lead to the loss of skin and ulcers these wounds can harm the ability of a fish to control the movement of water into its body damage caused to the gill tissue of an infected fish can also reduce respiratory efficiency this means it is more difficult for the fish to obtain oxygen from the water and becomes less tolerant to low levels of dissolved oxygen
ichthyosis plural ichthyoses is a heterogeneous family of at least 28 generalized mostly genetic skin disorders all types of ichthyosis have dry thickened scaly or flaky skin in many types there is cracked skin which is said to resemble the scales on a fish the word ichthyosis comes from the ancient greek ἰχθύς ichthys meaning fish the severity of symptoms can vary enormously from the mildest most common type such as ichthyosis vulgaris which may be mistaken for normal dry skin up to life threatening conditions such as harlequin type ichthyosis ichthyosis vulgaris accounts for more than 95 of cases
ichthyosis acquisita or acquired ichthyosis is a disorder clinically and histologically similar to ichthyosis vulgaris
ichthyosis bullosa of siemens is a type of familial autosomal dominant ichthyosis a rare skin disorder it is also known as bullous congenital ichthyosiform erythroderma of siemens or ichthyosis exfoliativa it is a genetic disorder with no known cure which is estimated to affect about 1 in 500 000 people
ichthyosis hystrix is a group of rare skin disorders in the ichthyosis family of skin disorders characterized by massive hyperkeratosis with an appearance like spiny scales this term is also used to refer to a type of epidermal nevi with extensive bilateral distribution
ichthyosis linearis circumflexa is a distinctive skin condition of generalized hyperkeratosis and polycyclic and serpiginous erythematous plaques with a characteristic migratory double edged scale at the margins and is the typical cutaneous manifestation of netherton s syndrome
ichthyosis prematurity syndrome ips is a dermatological disease with known genetic causes this syndrome is a rare subcategory of autosomal recessive congenital ichthyosis arci it is associated with complications in the mid trimester of a pregnancy leading to premature births although most prevalent in individuals of scandinavian origin there have also been scattered cases in people of japanese italian and indian ethnicity this disorder is also referred to as ichthyosis congenital type iv
ichthyosis vulgaris also known as autosomal dominant ichthyosis and ichthyosis simplex is a skin disorder causing dry scaly skin it is the most common form of ichthyosis affecting around 1 in 250 people for this reason it is known as common ichthyosis it is usually an autosomal dominant inherited disease often associated with filaggrin although a rare non heritable version called acquired ichthyosis exists
ichthyosis en confetti also known as ichthyosis with confetti congenital reticular ichthyosiform erythroderma crie and ichthyosis variegata is a very rare form of congenital ichthyosis in which healthy patches of normal skin co exist within the abnormal skin areas the condition is caused by a frameshift mutation in the keratin 10 gene krt 10 mutant keratin 10 accumulates in the nucleolus a sub nuclear structure rather than within cellular intermedite filaments like the wild type protein children with the condition exhibit red flaky skin however for reasons not yet totally clear wild type clonal patches of skin start to appear in place of the red flaky skin due to the clonal nature of the growth of the normal skin cells it appears the patient is covered with confetti hence the name of the condition it has been hypothesized that this is the result of a combination of mitotic recombination and natural selection within the skin
ictal bradycardia is a diagnosis in which people that have temporal lobe epilepsy experience bradycardia and is also accompanied by seizures epileptic discharges bradycardia is defined by a slower than normal heart rate less than 60 bpm normal range is 60 100 bpm ictal epileptic discharges can effect changes in cardiac rhythm an increase in heart rhythm is common during seizures this type of epileptic seizure is known as ictal tachycardia in which the subject s heart rate increase of more than 10 beats per minute of above the baseline in comparison ictal bradycardia causes epileptic discharges that disrupt the normal cardiac rhythm in a negative fashion slowing the heart beat down by more than 10 beats per minute below the average baseline ictal bradycardia is a potential cause or reason for ictal asystole to occur and is believed to help explain the phenomenon of sudden unexpected death in epilepsy sudep through the simultaneous use of electroencephalograph eeg and electrocardiograms ecg researchers can monitor and record a patient going through ictal bradycardia seizures and most importantly provide treatment with both antiepileptic drugs and cardiac pace as deemed necessary for the patient although there is limited amount of information about ictal bradycardia as it is a relatively new discovery and is considered to be rare condition researchers suggest that early diagnosis and treatment of ictal bradycardia can eliminate the chances of sudden unexpected death in epilepsy
ictal headaches are headaches associated with seizure activity they may occur either before pre ictal or after post ictal a seizure and in rare circumstances during a seizure many cases of ictal headache may be misdiagnosed as migraine with aura or even cluster headache however while these conditions usually involve just one side of the head are unilateral an ictal headache may be centrally situated or cover the entirety of the head
id reactions also known as disseminated eczema and generalized eczema present with a variety of infectious disorders often occurring in response to an inflammatory tinea of the feet resulting in an eczematous dermatitis the inflammation is in the absence of a locally visible cause
ideational apraxia ia is a neurological disorder which explains the loss of ability to conceptualize plan and execute the complex sequences of motor actions involved in the use of tools or otherwise interacting with objects in everyday life ideational apraxia is a condition in which an individual is unable to plan movements related to interaction with objects because he has lost the perception of the object s purpose characteristics of this disorder include a disturbance in the concept of the sequential organization of voluntary actions the patient appears to have lost the knowledge or thought of what an object represents this disorder was first seen 100 years ago by doctor arnold pick who described a patient who appeared to have lost their ability to use objects the patient would make errors such as combing their hair with the wrong side of the comb or placing a pistol in his mouth from that point on several other researchers and doctors have stumbled upon this unique disorder ia has been described under several names such as agnosia of utilization conceptual apraxia or loss of knowledge about the use of tools or semantic amnesia of tool usage the term apraxia was first created by steinthal in 1871 and was then applied by gogol kusmaul star and pick to patients who failed to pantomime the use of tools it was not until the 1900 s when liepmann refined the definition that it specifically described disorders that involved motor planning rather than disturbances in the patient ’ s visual perception language or symbolism
identity assurance in the context of federated identity management is the ability for a party to determine with some level of certainty that an electronic credential representing an entity human or a machine with which it interacts to effect a transaction can be trusted to actually belong to the entity in the case where the entity is a person identity assurance is the level at which the credential being presented can be trusted to be a proxy for the individual to whom it was issued and not someone else assurance levels als or loas are the levels of trust associated with a credential as measured by the associated technology processes and policy and practice statements
in mathematics an identity function also called an identity relation or identity map or identity transformation is a function that always returns the same value that was used as its argument in equations the function is given by f x x
in the design of database management systems the identity map pattern is a database access design pattern used to improve performance by providing a context specific in memory cache to prevent duplicate retrieval of the same object data from the database if the requested data has already been loaded from the database the identity map returns the same instance of the already instantiated object but if it has not been loaded yet it loads it and stores the new object in the map in this way it follows a similar principle to lazy loading there are four types of identity map explicit generic session class
ideomotor apraxia often ima is a neurological disorder characterized by the inability to correctly imitate hand gestures and voluntarily mime tool use e g pretend to brush one s hair the ability to spontaneously use tools such as brushing one s hair in the morning without being instructed to do so may remain intact but is often lost the general concept of apraxia and the classification of ideomotor apraxia were developed in germany in the late 19 th and early 20 th centuries by the work of hugo liepmann adolph kussmaul arnold pick paul flechsig hermann munk carl nothnagel theodor meynert and linguist heymann steinthal among others ideomotor apraxia was classified as ideo kinetic apraxia by liepmann due to the apparent dissociation of the idea of the action with its execution the classifications of the various subtypes are not well defined at present however owing to issues of diagnosis and pathophysiology ideomotor apraxia is hypothesized to result from a disruption of the system that relates stored tool use and gesture information with the state of the body to produce the proper motor output this system is thought to be related to the areas of the brain most often seen to be damaged when ideomotor apraxia is present the left parietal lobe and the premotor cortex little can be done at present to reverse the motor deficit seen in ideomotor apraxia although the extent of dysfunction it induces is not entirely clear
ideomotor phenomenon is a psychological phenomenon wherein a subject makes motions unconsciously the ideomotor response or ideomotor reflex often abbreviated to imr is a concept in hypnosis and psychological research it is derived from the terms ideo idea or mental representation and motor muscular action the phrase is most commonly used in reference to the process whereby a thought or mental image brings about a seemingly reflexive or automatic muscular reaction often of minuscule degree and potentially outside of the awareness of the subject as in reflexive responses to pain the body sometimes reacts reflexively with an ideomotor effect to ideas alone without the person consciously deciding to take action the effects of automatic writing dowsing facilitated communication and ouija boards have been attributed to the phenomenon mystics have often attributed these effects to paranormal or supernatural force many subjects are unconvinced that their actions are originating solely from within themselves the associated term ideo dynamic response or reflex applies to a wider domain and extends to the description of all bodily reactions including ideo motor and ideo sensory responses caused in a similar manner by certain ideas e g the salivation often caused by imagining sucking a lemon which is a secretory response the notion of an ideo dynamic response contributed to james braid s first neuro psychological explanation of the principle through which suggestion operated in hypnotism
idiopathic cd 4 lymphocytopenia icl is a very rare medical syndrome in which the body has too few cd 4 t lymphocytes which are a kind of white blood cell icl is sometimes characterized as hiv negative aids by aids denialists though in fact its clinical presentation differs from that seen with hiv aids people with icl have a weakened immune system and are susceptible to opportunistic infections although the rate of infections is lower than in people with aids
idiopathic craniofacial erythema is a medical condition characterised by severe uncontrollable and frequently unprovoked facial blushing blushing can occur at any time and is frequently triggered by even mundane events such as talking to friends paying for goods in a shop asking for directions or even simply making eye contact with another person for many years the cause of the condition was thought to be an anxiety problem caused by a mental health disorder however in recent years experts in the field of the disorder believe it to be caused by an overactive sympathetic nervous system an automatic response which sufferers have no mental control over it is related to focal hyperhidrosis more commonly known as excessive sweating as it is caused by the same overactive nerves which cause excessive sweating sufferers of severe facial blushing commonly experience focal hyperhidrosis studies have also shown that patients with severe facial blushing or focal hyperhidrosis commonly have family members with one or both of the related disorders
idiopathic eruptive macular pigmentation is a skin condition developing in young persons with an average age of 11 characterized by asymptomatic widespread brown to gray macules of up to several centimeters in diameter on the neck trunk and proximal extremities
idiopathic facial aseptic granuloma is a cutaneous condition characterized by a chronic painless solitary nodule reminiscent of an acne nodule appearing on the cheeks of young children it has a prolonged course but spontaneously heals
idiopathic giant cell myocarditis igcm is a cardiovascular disease the condition is rare however it is often fatal and there is no proven cure because of the unknown nature of the disorder igcm frequently leads to death with a high rate of about 70 in first year a patient with igcm typically presents with symptoms of heart failure although some may present initially with ventricular arrhythmia or heart block median age from the time the disease is diagnosed to the time of death is approximately 6 months 90 of patients are either deceased by the end of 1 year or have received a heart transplant diagnosis is made by endomyocardial biopsy during heart catheterization biopsy shows multinucleated giant cells and thus the name there is no treatment except for heart transplantation the transplanted heart has a high chance of disease recurrence compared to lymphocytic presumed viral myocarditis giant cell myocarditis is much more severe with much more rapid progression it is suggested to be caused by t lymphocytes
idiopathic granulomatous hepatitis is a rare medical condition characterised by granulomas in the liver recurrent fever myalgia and fatigue the condition is not a true hepatitis and some experts believe it is a variant of sarcoidosis
idiopathic guttate hypomelanosis also known as leukopathia symmetrica progressiva is a very common acquired disorder that affects women more frequently than men presenting with skin lesions that occur chiefly on sun exposed regions of the skin suggesting sun exposure may play a role
idiopathic hypersomnia is a condition thought to be a neurological disorder which is characterized primarily by excessive daytime sleepiness eds it has historically been rarely diagnosed and is often very difficult to diagnose at an early stage it is usually a lifelong chronic disease which is often debilitating there is a very low level of public awareness of idiopathic hypersomnia which often leads to stigma for those who suffer from it there is currently no cure but there are several off label treatments which are primarily fda approved narcolepsy medications research funding for its study is scarce in the medical literature idiopathic hypersomnia may also be referred to as ih ihs primary hypersomnia central hypersomnia or hypersomnia of brain origin the diagnostic and statistical manual of mental disorders fourth edition dsm iv defines idiopathic hypersomnia as eds without narcolepsy or the associated features of other sleep disorders it occurs in the absence of medical problems that can cause secondary hypersomnia and it occurs despite normal quality and quantity of night time sleep and sometimes despite exceptionally long periods of night time sleep primary hypersomnia is thought to arise from problems with the brain ’ s systems that regulate sleep and wake
idiopathic interstitial pneumonia iip or noninfectious pneumonia are a class of diffuse lung diseases these diseases typically affect the pulmonary interstitium although some also have a component affecting the airways for instance cryptogenic organizing pneumonitis there are seven recognized distinct subtypes of iip
idiopathic intracranial hypertension iih sometimes called by the older names benign intracranial hypertension bih or pseudotumor cerebri ptc is a neurological disorder that is characterized by increased intracranial pressure pressure around the brain in the absence of a tumor or other diseases the main symptoms are stroke like headache nausea and vomiting as well as pulsatile tinnitus sounds perceived in the ears with the sound occurring in the same rhythm as the pulse double vision and other visual symptoms if untreated it may lead to swelling of the optic disc in the eye which can progress to vision loss iih is diagnosed with a brain scan to rule out other causes and a lumbar puncture lumbar puncture may also provide temporary and sometimes permanent relief from the symptoms some respond to medication with the drug acetazolamide topiramate furosemide others or a combination but others require surgery to relieve the pressure the condition may occur in all age groups but is most common in women aged 20 – 40
idiopathic osteosclerosis is a condition which may be found around the roots of a tooth it is usually painless and found during routine radiographs it appears as a radiopaque light area around a tooth usually a premolar or molar there is no sign of inflammation of the tooth
idiopathic pulmonary fibrosis ipf is a chronic and ultimately fatal disease characterized by a progressive decline in lung function the term pulmonary fibrosis means scarring of lung tissue and is the cause of worsening dyspnea shortness of breath fibrosis is usually associated with a poor prognosis ipf belongs to a large group of more than 200 lung diseases known as interstitial lung diseases ilds characterized by the involvement of lung interstitium the interstitium the tissue between the air sacs in the lung is the primary site of injury in ilds however these disorders frequently affect not only the interstitium but also the airspaces peripheral airways and vessels lung tissue from people with ipf shows a characteristic histopathologic pattern known as usual interstitial pneumonia uip uip is therefore the pathologic counterpart of ipf the term idiopathic is used because the cause of pulmonary fibrosis is still unknown ipf usually occurs in adult individuals of between 50 and 70 years of age particularly those with a history of cigarette smoking and affects more men than women the diagnosis of ipf requires exclusion of other known causes of ilds and the presence of a typical radiological pattern identified through high resolution computed tomography hrct in the right clinical setting it is possible to make the diagnosis of ipf by hrct alone obviating the need for surgical lung biopsy treatment may include nintedanib or pirfenidone
idiopathic pulmonary haemosiderosis or idiopathic pulmonary hemosiderosis iph is a lung disease of unknown cause that is characterized by alveolar capillary bleeding and accumulation of haemosiderin in the lungs it is rare with an incidence between 0 24 and 1 23 cases per million people
idiopathic sclerosing mesenteritis ism or mesenteric panniculitus is a rare disease of the small intestine characterized by chronic inflammation and eventual fibrosis of the mesentery it has also been called mesenteric lipodystrophy or retractile mesenteritis
idiopathic scrotal calcinosis also known as idiopathic calcified nodules of the scrotum is a cutaneous condition characterized by calcification of the skin resulting from the deposition of calcium and phosphorus occurring on the scrotum however the levels of calcium and phosphate in the blood are normal idiopathic scrotal calcinosis typically affects young males with an onset between adolescence and early adulthood the scrotal calcinosis appears without any symptoms as yellowish nodules that range in size from 1 mm to several centimeters
idiopathic short stature iss refers to extreme short stature that does not have a diagnostic explanation idiopathic designates a condition that is unexplained or not understood after an ordinary growth evaluation the term has been in use since at least 1975 without a precise percentile or statistical definition of extreme
idiosyncratic drug reactions also known as type b reactions are drug reactions that occur rarely and unpredictably amongst the population this is not to be mistaken with idiopathic which implies that the cause is not known they frequently occur with exposure to new drugs as they have not been fully tested and the full range of possible side effects have not been discovered they may also be listed as an adverse drug reaction with a drug but are extremely rare some patients have multiple drug intolerance patients who have multiple idiopathic effects that are nonspecific are more likely to have anxiety and depression idiosyncratic drug reactions appear to not be concentration dependent a minimal amount of drug will cause an immune response but it is suspected that at a low enough concentration a drug will be less likely to initiate an immune response
iga nephropathy igan also known as iga nephritis berger disease bɛərˈʒeɪ and variations or synpharyngitic glomerulonephritis is a disease of the kidney or nephropathy specifically it is a form of glomerulonephritis or an inflammation of the glomeruli of the kidney iga nephropathy is the most common glomerulonephritis worldwide primary iga nephropathy is characterized by deposition of the iga antibody in the glomerulus there are other diseases associated with glomerular iga deposits the most common being iga vasculitis formerly known as henoch – schönlein purpura hsp which is considered by many to be a systemic form of iga nephropathy hsp presents with a characteristic purpuric skin rash arthritis and abdominal pain and occurs more commonly in young adults 16 – 35 years old hsp is associated with a more benign prognosis than iga nephropathy in iga nephropathy there is a slow progression to chronic kidney failure in 25 – 30 of cases during a period of 20 years
iga pemphigus is a subtype of pemphigus with two distinct forms subcorneal pustular dermatosis also known as sneddon – wilkinson disease distinct from and not to be confused with subcorneal pustular dermatosis type of iga pemphigus is skin condition that is a rare chronic recurrent pustular eruption characterized histopathologically by subcorneal pustules that contain abundant neutrophils intraepidermal neutrophilic iga dermatosis is characterized histologically by intraepidermal bullae with neutrophils some eosinophils and acantholysis
iga vasculitis is a cutaneous condition characterized by inflammatory retiform purpura
igg 4 related disease igg 4 rd is a chronic inflammatory condition characterised by tissue infiltration with lymphocytes and igg 4 secreting plasma cells various degrees of fibrosis scarring and a prompt response usually to oral steroids it is a relapsing – remitting disease associated with a tendency to mass forming tissue destructive lesions in multiple sites with a characteristic histopathological appearance in whichever site is involved the disease which was formerly also known as igg 4 related systemic disease is so named because plasma cells producing the antibody subtype igg 4 are present in large amounts on tissue samples from involved organs and because serum igg 4 concentrations are elevated in approximately 60 – 70 of people during an acute phase inflammation resulting in fibrosis the deposition of connective tissue in affected anatomical sites can lead to organ dysfunction or even organ failure if not treated early detection is important to avoid organ damage and potentially serious complications treatment is recommended in all symptomatic cases of igg 4 rd and also in asymptomatic igg 4 rd involving certain anatomical sites
igg 4 related ophthalmic disease igg 4 rod is the recommended term to describe orbital eye socket manifestations of the systemic condition igg 4 related disease which is characterised by infiltration of lymphocytes and plasma cells and subsequent fibrosis in involved structures it can involve one or more of the orbital structures frequently involved structures include the lacrimal glands extraocular muscles infraorbital nerve supraorbital nerve and eyelids it has also been speculated that ligneous conjunctivitis may be a manifestation of igg 4 related disease igg 4 rd as is the case with other manifestations of igg 4 related disease a prompt response to steroid therapy is a characteristic feature of igg 4 rod in most cases unless significant fibrosis has already occurred
igg 4 related prostatitis is the term used to describe prostate involvement in men with igg 4 related disease igg 4 rd which is an emerging fibroinflammatory disease entity which is characterised i by a tendency to tumefactive or mass forming lesions in multiple sites of the body and ii by usually a prompt response to steroid therapy men with igg 4 related prostatitis may present synchronously or metachronously with manifestations of igg 4 rd at other sites anywhere in the body
igg 4 related skin disease is the recommended name for skin manifestations in igg 4 related disease igg 4 rd multiple different skin manifestations have been described
igg deficiency selective deficiency of immunoglobulin g is a form of dysgammaglobulinemia where the proportional levels of the igg isotype are reduced relative to other immunoglobulin isotypes igg deficiency is often found in children as transient hypogammaglobulinemia of infancy thi which may occur with or without additional decreases in iga or igm igg has four subclasses igg 1 igg 2 igg 3 and igg 4 it is possible to have either a global igg deficiency or a deficiency of one or more specific subclasses of igg the main clinically relevant form of igg deficiency is igg 2 igg 3 deficiency is not usually encountered without other concomitant immunoglobulin deficiencies and igg 4 deficiency is very common but usually asymptomatic igg 1 is present in the bloodstream at a percentage of about 60 70 igg 2 20 30 igg 3 about 5 8 and igg 4 1 3 igg subclass deficiencies affect only igg subclasses usually igg 2 or igg 3 with normal total igg and igm immunoglobulins and other components of the immune system being at normal levels these deficiencies can affect only one subclass or involve an association of two subclasses such as igg 2 and igg 4 igg deficiencies are usually not diagnosed until the age of 10 some of the igg levels in the blood are undetectable and have a low percentage such as igg 4 which makes it hard to dertermine if a deficiency is actually present igg subclass deficiencies are sometimes correlated with bad responses to pneumoccal polyscaccharides especially igg 2 and or igg 4 deficiency some of these deficiencies are also involved with pancreatitis and have been linked to igg 4 levels
in mathematics an igusa zeta function is a type of generating function counting the number of solutions of an equation modulo p p 2 p 3 and so on
in mathematics the ihara zeta function is a zeta function associated with a finite graph it closely resembles the selberg zeta function and is used to relate closed paths to the spectrum of the adjacency matrix the ihara zeta function was first defined by yasutaka ihara in the 1960 s in the context of discrete subgroups of the two by two p adic special linear group jean pierre serre suggested in his book trees that ihara s original definition can be reinterpreted graph theoretically it was toshikazu sunada who put this suggestion into practice 1985 as observed by sunada a regular graph is a ramanujan graph if and only if its ihara zeta function satisfies an analogue of the riemann hypothesis
iich aa navajo iichʼąh is a culture specific syndrome in the navajo culture it causes behavior similar to amok a syndrome found in other cultures
ila pr e la is a birthmark found amongst samoan infants up until the last seventy years it was initially described in richard parkinson s classic text thirty years in the south seas the mark is circular in shape about 10 cm across and lies just above the buttocks of infants up to the age of six months it has a faint dark blue color the birthmark is apparently homozygous recessive nearly all samoan infants were born with this mark but any ancestry outside of samoa however slight results in the infant not showing the mark the birthmark is now very rare in samoa and can only be found occasionally on remote islands to the west
ileitis is an inflammation of the ileum a portion of the small intestine crohn s ileitis is a type of crohn s disease affecting the ileum ileitis is caused by the bacterium lawsonia intracellularis inflammatory bowel disease does not associate with lawsonia intracellularis infection
an ileosigmoid knot is a form of volvulus in which ileum wraps around the base of the sigmoid and passes beneath itself forming a knot the exact cause of this condition is not known patients usually present with clinical features of colonic obstruction vomoting abdominal distension abdominal pain blood stained stools are frequent symptoms it is difficult to diagnose this condition before surgery raveenthiran described a triad which may be useful in preoperative diagnosis the triad includes 1 clinical features suggestive of small bowel obstruction 2 radiological features suggestive of large bowel obstruction 3 inability to negotiate sigmoidoscope or a flatus tube this is a surgical emergency that requires urgent resection of gangrenous bowel and untwisting of the volvulus
ileus is a disruption of the normal propulsive ability of the gastrointestinal tract although ileus originally referred to any lack of digestive propulsion including bowel obstruction up to date medical usage restricts its meaning to those disruptions caused by the failure of peristalsis rather than by mechanical obstruction although certain older terms such as gallstone ileus and meconium ileus persist in usage they are now misnomers which does not mean that they are incorrect or obsolete but rather that they are known to not sound like what they really are the word ileus is from greek εἰλεός eileós intestinal obstruction
iliopsoas bursitis is inflammation of a bursa synovial sac lying between iliopsoas muscle and hip joint lateral to femoral vessels pain is experienced over the same area and made worse by extension of hip joint
iliotibial band syndrome itbs or itbfs for iliotibial band friction syndrome is a common injury to the knee generally associated with running cycling hiking or weight lifting especially squats
illegal immigration in chile is a growing phenomenon as many illegal immigrants from peru this illegal immigration phenomenon is due to chile growing economy
illegal immigration in china is a major problem particularly with north korean refugees and defectors fleeing their country the chinese government actively discourages this type of behavior out of fears that it may cause instability in the region and encourage more illegal immigration the government has been criticized for its aggressive approach to illegal immigration china is building a security barrier along its border with north korea to prevent the defectors or refugees from north korea also many immigrants from mongolia have tried to make it to china there might be as many as 100 000 africans and arabs in guangzhou mostly illegal overstayers to encourage people to report foreigners living illegally in china the police are giving a 100 yuan reward to whistleblowers whose information successfully leads to an expulsion
illegal immigration in nigeria is a serious problem and the border has become quite porous according to the government there are 1 497 illegal migration points to enter the country the government is investing millions to secure the border people from niger are biggest group of illegal immigrants
the illumination problem is a resolved mathematical problem first posed by ernst straus in the 1950 s straus asked if a room with mirrored walls can always be illuminated by a single point light source allowing for repeated reflection of light off the mirrored walls alternatively the question can be stated as asking that if a billiard table can be constructed in any required shape is there a shape possible such that there is a point where it is impossible to pot the billiard ball in a pocket at another point assuming the ball is point like and continues infinitely rather than stopping due to friction the problem was first solved in 1958 by roger penrose using ellipses to form the penrose unilluminable room he showed there exists a room with curved walls that must always have dark regions if lit only by a single point source this problem was also solved for polygonal rooms by george tokarsky in 1995 for 2 dimensions which showed there exists an unilluminable polygonal 26 sided room with a dark spot which is not illuminated from another point in the room even allowing for repeated reflections this was a borderline case however since a finite number of dark points rather than regions are unilluminable from any given position of the point source an improved solution was put forward by d castro in 1997 with a 24 sided room with the same properties
illusory correlation is the phenomenon of perceiving a relationship between variables typically people events or behaviors even when no such relationship exists a common example of this phenomenon is the formation of a false association between membership in a statistical minority group e g african americans and a rare typically negative behavior e g drug abuse this false association is formed because rare or novel occurrences are more salient and therefore tend to capture one s attention this is one way stereotypes form and endure found that stereotypes can lead people to expect certain groups and traits to fit together and then to overestimate the frequency with which these correlations actually occur
illusory palinopsia greek palin for again and opsia for seeing is a subtype of palinopsia a visual disturbance defined as the persistent or recurrence of a visual image after the stimulus has been removed palinopsia is a broad term describing a heterogeneous group of symptoms which is divided into hallucinatory palinopsia and illusory palinopsia illusory palinopsia is likely due to sustained awareness of a stimulus and is similar to a visual illusion the distorted perception of a real external stimulus illusory palinopsia is caused by migraines hallucinogen persisting perception disorder hppd prescription drugs and head trauma but is also sometimes idiopathic illusory palinopsia consists of afterimages that are short lived or unformed occur at the same location in the visual field as the original stimulus and are often exposed or exacerbated based on environmental parameters such as stimulus intensity background contrast fixation and movement illusory palinopsia symptoms occur continuously or predictably based on environmental conditions
imaginary friends also known as pretend friends or invisible friends are a psychological and social phenomenon where a friendship or other interpersonal relationship takes place in the imagination rather than external physical reality although they may seem very real to their creators children usually understand that their imaginary friends are not real the first studies focusing on imaginary friends are believed to have been conducted during the 1890 s there is little information about the development and the appearance of imaginary friends in children however klausen passman 2007 report that imaginary companions were originally described as being supernatural creatures and spirits that were thought to connect people with their past lives adults in early historic times had entities such as household gods and guardian angels and muses that functioned as imaginary companions to provide comfort guidance and inspiration for creative work eventually the phenomenon of imaginary companions passed on to children the era when children began having imaginary friends is unknown but it is possible the phenomenon appeared in the mid – 20 th century when childhood was emphasized as an important time to play and imagine
imagination also called the faculty of imagining is the creative ability to form images ideas and sensations in the mind without direct input from the senses such as seeing or hearing imagination helps make knowledge applicable in solving problems and is fundamental to integrating experience and the learning process a basic training for imagination is listening to storytelling narrative in which the exactness of the chosen words is the fundamental factor to evoke worlds it is accepted as the innate ability and process of inventing partial or complete personal realms within the mind from elements derived from sense perceptions of the shared world the term is technically used in psychology for the process of reviving in the mind percepts of objects formerly given in sense perception since this use of the term conflicts with that of ordinary language some psychologists have preferred to describe this process as imaging or imagery or to speak of it as reproductive as opposed to productive or constructive imagination imagined images are seen with the mind s eye imagination can also be expressed through stories such as fairy tales or fantasies children often use such narratives and pretend play in order to exercise their imaginations when children develop fantasy they play at two levels first they use role playing to act out what they have developed with their imagination and at the second level they play again with their make believe situation by acting as if what they have developed is an actual reality
the imbert – fiodaraŭ effect named after fiodar ivanavič fiodaraŭ 1911 – 1994 and christian imbert 1937 – 1998 is an optical phenomenon in which circularly or elliptically polarized light undergoes a small phase shift when totally internally reflected the phase shift is perpendicular to the plane containing the incident and reflected beams this effect is the circular polarization analog of the goos – hänchen effect
imbrication is a phenomenon occurring in many bantu languages in which morphemes interweave in certain morphophonological conditions for example consider the setswana verb root rek a buy the passive voice is formed by adding the extension w to produce rek w a the perfect is formed by adding the morpheme ile to produce rek ile but when these are combined to produce the perfect form of the passive voice the verb becomes rek il w e with the perfect morpheme split into two pieces rather than the expected rek w ile
iminoglycinuria sometimes called familial iminoglycinuria is an autosomal recessive disorder of renal tubular transport affecting reabsorption of the amino acid glycine and the imino acids proline and hydroxyproline this results in excess urinary excretion of all three acids uria denotes in the urine iminoglycinuria is a rare and complex disorder associated with a number of genetic mutations that cause defects in both renal and intestinal transport systems of glycine and imino acids imino acids typically contain an imine functional group instead of the amino group found in amino acids proline is considered and usually referred to as an amino acid but unlike others it has a secondary amine this feature unique to proline identifies proline also as an imino acid hydroxyproline is another imino acid made from the naturally occurring hydroxylation of proline
an immature teratoma is a rare type of malignant cancerous germ cell tumor type of tumor that begins in the cells that give rise to sperm or eggs like a mature teratoma it contains several different types of tissue such as hair muscle and bone unlike a mature teratoma it contains primitive neuroepithelium
an immediately invoked function expression or iife pronounced iffy is a javascript programming language idiom which produces a lexical scope using javascript s function scoping immediately invoked function expressions can be used to avoid variable hoisting from within blocks protect against polluting the global environment and simultaneously allow public access to methods while retaining privacy for variables defined within the function this concept has been referred to as a self executing anonymous function but ben alman introduced the term iife as a more semantically accurate term for the idiom shortly after its discussion arose on comp lang javascript
immersion into virtual reality is a perception of being physically present in a non physical world the perception is created by surrounding the user of the vr system in images sound or other stimuli that provide an engrossing total environment the name is a metaphoric use of the experience of submersion applied to representation fiction or simulation immersion can also be defined as the state of consciousness where a visitor maurice benayoun or immersant char davies s awareness of physical self is transformed by being surrounded in an artificial environment used for describing partial or complete suspension of disbelief enabling action or reaction to stimulations encountered in a virtual or artistic environment the degree to which the virtual or artistic environment faithfully reproduces reality determines the degree of suspension of disbelief the greater the suspension of disbelief the greater the degree of presence achieved
immersion foot syndromes include trench foot tropical immersion foot and warm water immersion foot
immigration to the united states is a complex demographic phenomenon that has been a major source of population growth and cultural change throughout much of the history of the united states the economic social and political aspects of immigration have caused controversy regarding ethnicity economic benefits jobs for non immigrants settlement patterns impact on upward social mobility crime and voting behavior in 2005 the united states per capita ranked 34 th out of 179 world nations in the number of immigrants allowed into the country prior to 1965 policies such as the national origins formula limited immigration and naturalization opportunities for people from areas outside western europe exclusion laws enacted as early as the 1880 s generally prohibited or severely restricted immigration from asia and quota laws enacted in the 1920 s curtailed eastern european immigration the civil rights movement of the 1960 s led to the replacement of these ethnic quotas with per country limits since then the number of first generation immigrants living in the united states has quadrupled from 9 6 million in 1970 to about 38 million in 2007 nearly 14 million immigrants entered the united states from 2000 to 2010 and over one million persons were naturalized as u s citizens in 2008 the per country limit applies the same maximum on the number of visas to all countries regardless of their population and has therefore had the effect of significantly restricting immigration of persons born in populous nations such as mexico china india and the philippines – the leading countries of origin for legally admitted immigrants to the united states in 2013 nevertheless china india and mexico were the leading countries of origin for immigrants overall to the united states in 2013 regardless of legal status according to a u s census bureau study as of 2009 66 of legal immigrants were admitted on the basis of family ties along with 13 admitted for their employment skills and 17 for humanitarian reasons for those who enter the us illegally across the mexico – united states border and elsewhere migration is difficult expensive and dangerous virtually all undocumented immigrants have no avenues for legal entry to the united states due the restrictive legal limits on green cards and lack of immigrant visas for low skilled workers participants in debates on immigration in the early twenty first century called for increasing enforcement of existing laws governing illegal immigration to the united states building a barrier along some or all of the 2 000 mile 3 200 km mexico u s border or creating a new guest worker program through much of 2006 the country and congress was immersed in a debate about these proposals as of april 2010 few of these proposals had become law though a partial border fence had been approved and subsequently canceled
immortality is eternal life the ability to live forever natural selection has developed potential biological immortality in at least one species turritopsis dohrnii certain scientists futurists and philosophers have theorized about the immortality of the human body either through an immortal cell line researched or else deeper contextual understanding in advanced fields that have certain scope in the proposed long term reality that can be attained such as per mentioned in the reading of an article or scientific documentation of such a proposed idea would lead to and advocate that human immortality is achievable in the first few decades of the 21 st century whereas other advocates believe that life extension is a more achievable goal in the short term with immortality awaiting further research breakthroughs into an indefinite future the absence of aging would provide humans with biological immortality but not invulnerability to death by physical trauma although mind uploading could solve that issue if it proved possible whether the process of internal endoimmortality would be delivered within the upcoming years depends chiefly on research and in neuron research in the case of endoimmortality through an immortalized cell line in the former view and perhaps is an awaited goal in the latter case in religious contexts immortality is often stated to be one of the promises of god or other deities to human beings who show goodness or else follow divine law what form an unending human life would take or whether an immaterial soul exists and possesses immortality has been a major point of focus of religion as well as the subject of speculation fantasy and debate
an immune disorder is a dysfunction of the immune system these disorders can be characterized in several different ways by the component s of the immune system affected by whether the immune system is overactive or underactive by whether the condition is congenital or acquired according to the international union of immunological societies more than 150 primary immunodeficiency diseases pids have been characterized however the number of acquired immunodeficiencies exceeds the number of pids it has been suggested that most people have at least one primary immunodeficiency due to redundancies in the immune system though many of these are never detected
immune reconstitution inflammatory syndrome iris also known as immune recovery syndrome is a condition seen in some cases of aids or immunosuppression in which the immune system begins to recover but then responds to a previously acquired opportunistic infection with an overwhelming inflammatory response that paradoxically makes the symptoms of infection worse
immune thrombocytopenia itp is a type of thrombocytopenic purpura defined as isolated low platelet count thrombocytopenia with normal bone marrow and the absence of other causes of thrombocytopenia it causes a characteristic purpuric rash and an increased tendency to bleed two distinct clinical syndromes manifest as an acute condition in children and a chronic condition in adults the acute form often follows an infection and has a spontaneous resolution within two months chronic immune thrombocytopenia persists longer than six months with a specific cause being unknown itp is an autoimmune disease with antibodies detectable against several platelet surface antigens itp is diagnosed by a low platelet count in a complete blood count a common blood test however since the diagnosis depends on the exclusion of other causes of a low platelet count additional investigations such as a bone marrow biopsy may be necessary in some cases in mild cases only careful observation may be required but very low counts or significant bleeding may prompt treatment with corticosteroids intravenous immunoglobulin anti d immunoglobulin or immunosuppressive drugs refractory itp not responsive to conventional treatment may require splenectomy the surgical removal of the spleen platelet transfusions may be used in severe bleeding together with a very low count sometimes the body may compensate by making abnormally large platelets
immune tolerance in pregnancy or gestational maternal immune tolerance is the absence of a maternal immune response against in other words immune tolerance towards the fetus and placenta during pregnancy which thus may be viewed as unusually successful allografts since they genetically differ from the mother in the same way many cases of spontaneous abortion may be described in the same way as maternal transplant rejection it is studied within the field of reproductive immunology
immunocompetence is the ability of the body to produce a normal immune response following exposure to an antigen immunocompetence is the opposite of immunodeficiency or immuno incompetent or immuno compromised examples include a newborn who does not yet have a fully functioning immune system but may have maternally transmitted antibodies immunodeficient a late stage aids patient with a failed or failing immune system immuno incompetent or a transplant recipient taking medication so their body will not reject the donated organ immunocompromised there may be cases of overlap but these terms all describe immune system not fully functioning the us centers for disease control and prevention cdc recommends that household and other close contacts of persons with altered immunocompetence receive the mmr varicella and rotavirus vaccines according to the standard schedule of vaccines as well as receiving an annual flu shot all other vaccines may be administered to contacts without alteration to the vaccine schedule with the exception of the smallpox vaccine persons with altered immunocompetence should not receive live attenuated vaccines viral or bacterial and may not receive the full benefit of inactivated vaccines in reference to lymphocytes immunocompetence means that a b cell or t cell is mature and can recognize antigens and allow a person to mount an immune response
immunodeficiency or immune deficiency is a state in which the immune system s ability to fight infectious disease is compromised or entirely absent most cases of immunodeficiency are acquired secondary due to extrinsic factors that affect the patient s immune system examples of these extrinsic factors include infections such as by human immunodeficiency virus hiv extremes of age and environmental factors such as nutrition in the clinical setting the immuno suppression quality of some drugs such as steroids can be utilised examples of such use is in transplant surgery as an anti rejection measure and in patients suffering from an over active immune system some people are born with defects in their immune system or primary immunodeficiency a person who has an immunodeficiency of any kind is said to be immunocompromised an immunocompromised person may be particularly vulnerable to opportunistic infections in addition to normal infections that could affect everyone immunodeficiency may also decrease cancer immunosurveillance
immunodeficiency with hyperimmunoglobulin m is a rare disorder characterized by recurrent infections low or absent igg ige and iga levels and normal or elevated levels of igm and igd
icf syndrome or immunodeficiency centromere instability and facial anomalies syndrome is a very rare autosomal recessive immune disorder
immunodominance is the immunological phenomenon in which immune responses are mounted against only a few of the antigenic peptides out of the many produced that is despite multiple allelic variations of mhc molecules and multiple peptides presented on antigen presenting cells the immune response is skewed to only specific combinations of the two immunodominance is evident for both antibody mediated immunity and cell mediated immunity epitopes that are not targeted or targeted to a lower degree during an immune response are known as subdominant epitopes the impact of immunodominance is immunodomination where immunodominant epitopes will curtail immune responses against non dominant epitopes antigen presenting cells such as dendritic cells can have up to six different types of mhc molecules for antigen presentation there is a potential for generation of hundreds to thousands of different peptides from the proteins of pathogens yet the effector cell population that is reactive against the pathogen is dominated by cells that recognize only a certain class of mhc bound to only certain pathogen derived peptides presented by that mhc class antigens from a particular pathogen can be of variable immunogenicity with the antigen that stimulates the strongest response being the immunodominant one the different levels of immunogenicity amongst antigens forms what is known as dominance hierarchy
immunogenicity is the ability of a particular substance such as an antigen or epitope to provoke an immune response in the body of a human or animal in other words immunogenicity is the ability to induce a humoral and or cell mediated immune responses differentiation has to be made between wanted and unwanted immunogenicity wanted immunogenicity is typically related with vaccines where the injection of an antigen the vaccine provokes an immune response against the pathogen virus bacteria aiming at protecting the organism vaccine development is a complex multistep process immunogenicity being at the center of the vaccine efficiency unwanted immunogenicity is an immune response by an organism against a therapeutic antigen ex recombinant protein or monoclonal antibody this reaction leads to production of anti drug antibodies adas inactivating the therapeutic effects of the treatment and in rare cases inducing adverse effects the prediction of the immunogenic potential of novel protein therapeutics is thus a challenge in biotherapy
immunoglobulin y abbreviated as igy is a type of immunoglobulin which is the major antibody in bird reptile and lungfish blood it is also found in high concentrations in chicken egg yolk as with the other immunoglobulins igy is a class of proteins which are formed by the immune system in reaction to certain foreign substances and specifically recognize them igy is often mislabelled as immunoglobulin g igg in older literature and sometimes even in commercial product catalogues due to its functional similarity to mammalian igg and immunoglobulin e ige however this older nomenclature is obsolete since igy differs both structurally and functionally from mammalian igg and does not cross react with antibodies raised against mammalian igg since chickens can lay eggs almost every day and the yolk of an immunised hen s egg contains a high concentration of igy chickens are gradually becoming popular as a source of customised antibodies for research usually mammals such as rabbits or goats are injected with the antigen of interest by the researcher or a contract laboratory ducks produce a truncated form of igy which is missing part of the fc region as a result it cannot bind complement or be picked up by macrophages this may be one reason ducks are less easily killed by avian influenza compared to chickens but can still become infected and spread the virus easily igy has also been analyzed in the chinese soft shelled turtle pelodiscus sinensis
immunoproliferative disorders also known as immunoproliferative diseases or immunoproliferative neoplasms are disorders of the immune system that are characterized by the abnormal proliferation of the primary cells of the immune system which includes b cells t cells and natural killer nk cells or by the excessive production of immunoglobulins also known as antibodies
in object oriented programming immutable interface is a pattern for designing an immutable object the immutable interface pattern involves defining a type which does not provide any methods which mutate state objects which are referenced by that type are not seen to have any mutable state and appear immutable
impacted wisdom teeth or impacted third molars are wisdom teeth which do not fully erupt into the mouth because of blockage from other teeth impaction if the wisdom teeth do not have an open connection to the mouth pain can develop with the onset of inflammation or infection or damage to the adjacent teeth wisdom teeth likely become impacted because of a mismatch between the size of the teeth and the size of the jaw impacted wisdom teeth are classified by their direction of impaction their depth compared to the biting surface of adjacent teeth and the amount of the tooth s crown that extends through gum tissue or bone impacted wisdom teeth can also be classified by the presence or absence of symptoms and disease screening for the presence of wisdom teeth often begins in late adolescence when a partially developed tooth may become impacted screening commonly includes clinical examination as well as x rays such as panoramic radiographs infection resulting from impacted wisdom teeth can be initially treated with antibiotics local debridement or soft tissue surgery of the gum tissue overlying the tooth over time most of these treatments tend to fail and patients develop recurrent symptoms the most common treatment is wisdom tooth removal the risks of wisdom tooth removal are roughly proportional to the difficulty of the extraction sometimes when there is a high risk to the inferior alveolar nerve only the crown of the tooth will be removed intentionally leaving the roots in a procedure called a coronectomy the long term risk of coronectomy is that chronic infection can persist from the tooth remnants the prognosis for the second molar is good following the wisdom teeth removal with the likelihood of bone loss after surgery increased when the extractions are completed in people who are 25 years of age or older a treatment controversy exists about the need for and timing of the removal of disease free impacted wisdom teeth that are not causing problems supporters of early removal cite the increasing risks for extraction over time and the costs of monitoring the wisdom teeth that are not removed supporters for retaining wisdom teeth cite the risk and cost of unnecessary surgery this condition affects up to 72 of the swedish population wisdom teeth have been described in the ancient texts of plato and hippocrates the works of darwin and in the earliest manuals of operative dentistry it was the meeting of sterile technique radiology and anaesthesia in the late 19 th and early 20 th centuries that allowed the more routine management of impacted wisdom teeth
impaction is bowel obstruction that can occur in various kinds of animals when they consume something that they cannot digest for example in reptiles common causes of impaction are rocks and sand which might be accidentally consumed when the reptile attacks its prey in livestock rough fodder such as straw can risk impaction once the substance is ingested it will block the digestive tract and if untreated cause death
impaired fasting glucose ifg is a type of prediabetes in which the blood sugar level during fasting is consistently higher than what are considered normal levels however the level is not high enough to be diagnosed as diabetes mellitus this pre diabetic state is associated with insulin resistance and increased risk of cardiovascular pathology although of lesser risk than impaired glucose tolerance igt ifg can progress to type 2 diabetes mellitus if lifestyle changes are not made there is a 50 risk over 10 years of progressing to overt diabetes a recent study cited the average time for progression as less than three years fasting blood glucose levels are in a continuum within a given population with higher fasting glucose levels corresponding to a higher risk for complications caused by the high glucose levels impaired fasting glucose is defined as a fasting glucose that is higher than the upper limit of normal but not high enough to be classified as diabetes mellitus some patients with impaired fasting glucose can also be diagnosed with impaired glucose tolerance but many have normal responses to a glucose tolerance test
impaired glucose tolerance igt is a pre diabetic state of hyperglycemia that is associated with insulin resistance and increased risk of cardiovascular pathology igt may precede type 2 diabetes mellitus by many years igt is also a risk factor for mortality
the impakt festival is a yearly manifestation on media art founded in 1988 in the city of utrecht netherlands it showcases films video art performances music conferences and other special events with works from international artists dealing with questions about society digital culture and media the festival aims to tackle pressing questions from an interdisciplinary perspective
impalement as a method of execution is the penetration of a human by an object such as a stake pole spear or hook often by complete or partial perforation of the torso it was used particularly in response to crimes against the state and regarded across a number of cultures as a very harsh form of capital punishment and recorded in myth and art impalement was also used during wartime to suppress rebellion punish traitors or collaborators and as a punishment for breaches of military discipline offenses where impalement was occasionally employed include contempt for the state s responsibility for safe roads and trade routes by committing highway robbery or grave robbery violating state policies or monopolies or subverting standards for trade offenders have also been impaled for a variety of cultural sexual and religious reasons references to impalement in babylonia and the neo assyrian empire are found as early as the 18 th century bc within the ottoman empire this form of execution continued into the 20 th century
impeccability is the absence of sin christianity teaches this to be an attribute of god logically god cannot sin it would mean that he would act against his own will and nature and therefore it is also commonly but not uncontroversially attributed to christ
an imperforate anus or anorectal malformations arms are birth defects in which the rectum is malformed arms are a spectrum of different congenital anomalies in males and females that varies from fairly minor lesions to complex anomalies the cause of arms is unknown the genetic basis of these anomalies is very complex because of their anatomical variability in 8 of patients genetic factors are clearly associated with arms anorectal malformation in currarino syndrome represents the only association for which the gene hlxb 9 has been identified
an imperforate hymen is a congenital disorder where a hymen without an opening completely obstructs the vagina it is caused by a failure of the hymen to perforate during fetal development it is most often diagnosed in adolescent girls when menstrual blood accumulates in the vagina and sometimes also in the uterus it is treated by surgical incision of the hymen
an imperforate lacrimal punctum is a congenital disorder of dogs involving the lack of an opening to the nasolacrimal duct tear duct in the conjunctiva dogs normally have two lacrimal puncta the superior and inferior this condition can affect either or both symptoms include excessive tearing and tear staining of the hair around the eye affected breeds include the american cocker spaniel bedlington terrier golden retriever poodle and samoyed imperforate lacrimal puncta can be corrected by surgical opening of the punctum
impetigo is a bacterial infection that involves the superficial skin the most common presentation is yellowish crust on the face arms or legs less commonly there may be large blisters which affect the groin or armpits the lesions may be painful or itchy fever is uncommon it is typically due to either staphylococcus aureus or streptococcus pyogenes risk factors include attending daycare crowding poor nutrition diabetes contact sports and breaks in the skin such as from mosquito bites eczema or scabies with contact it can spread around or between people diagnosis is typically based on the symptoms prevention is by handwashing avoiding people who are infected and cleaning injuries treatment is typically with antibiotic creams such as mupirocin or fusidic acid antibiotics by mouth such as cephalexin may be used if large areas are affected antibiotic resistant forms have been found impetigo affected about 140 million people 2 of the population in 2010 it is most common in young children but can occur at any age without treatment people typically get better within three weeks complications may include cellulitis or poststreptococcal glomerulonephritis the name is from the latin impetere meaning attack
impetigo herpetiformis is a form of severe pustular psoriasis occurring in pregnancy which may occur during any trimester it is the only well known pustular psoriasis which is treated with steroids
impiety is a perceived lack of proper respect for something considered sacred impiety is often closely associated with sacrilege though it is not necessarily a physical action impiety cannot be associated with a cult as it implies a larger belief system was disrespected one of the pagan objections to christianity was that unlike other mystery religions early christians refused to cast a pinch of incense before the images of the gods an impious act in their eyes impiety in ancient civilizations was a civic concern rather than religious it was believed that impious actions such as disrespect towards sacred objects or priests could bring down the wrath of the gods impiety was often used to prosecute atheists
shoulder impingement syndrome also called subacromial impingement painful arc syndrome supraspinatus syndrome swimmer s shoulder and thrower s shoulder is a clinical syndrome which occurs when the tendons of the rotator cuff muscles become irritated and inflamed as they pass through the subacromial space the passage beneath the acromion this can result in pain weakness and loss of movement at the shoulder
in financial markets implementation shortfall is the difference between the decision price and the final execution price including commissions taxes etc for a trade this is also known as the slippage agency trading is largely concerned with minimizing implementation shortfall and finding liquidity
implicit divestiture is the ability of the supreme court of the united states to solely determine the extent of an indian nation s sovereignty an approach of recent decades to federal indian policy which is contradictory to u s constitutional protections of native american sovereignty the issue of indigenous sovereignty rights and their protections under federal trust in the united states was asserted in the 19 th century through supreme court cases called the marshall trilogy of johnson v mcintosh cherokee nation v georgia and worcester v georgia as indian law writer andrew fletcher terms it the “ colonial trilogy ” of oliphant v suquamish indian tribe montana v united states and nevada v hicks undermined tribal sovereignty through their introduction of “ implicit divestiture ” its application in respect to the united nations declaration on the rights of indigenous peoples is yet to be tested
an importation right is the legal ability to import a product into a certain country importation means sending goods from one country to another right means in accord with law
imposex is a disorder in sea snails caused by the toxic effects of certain marine pollutants these pollutants cause female sea snails marine gastropod molluscs to develop male sex organs such as a penis and a vas deferens
improvised sitcoms are a recent television phenomenon in which there is no definite script for the actors and actresses rather the actors actresses use the process of retroscripting in which there are rough outlines of themes and stories but the dialogue is up for the actors actresses to improvise because of the improvised fashion these sitcoms are usually shot by handheld camera in a documentary type style usually these shows have no laugh tracks predetermined entrances or punchlines such improvised sitcoms include curb your enthusiasm home movies and reno 911 in addition to these there are many scripted shows that will after getting principal photography let the actors do a couple of improv takes and often some of the best jokes that make it on the show will come from these takes notable examples of this would be the us version the office or parks and recreation and the british show the thick of it this method of television production has largely been welcomed by the established academies of the medium examples would include emmy and golden globe nominations for a show and the actors involved as well as strong support from publications and critics due to the amount of improvisation involved with filming many of the actors or actresses have experience in or were trained for stand up comedy and or improv comedy troupes
impulse control disorder icd is a class of psychiatric disorders characterized by impulsivity – failure to resist a temptation urge or impulse that may harm oneself or others many psychiatric disorders feature impulsivity including substance related disorders attention deficit hyperactivity disorder antisocial personality disorder borderline personality disorder conduct disorder and mood disorders the fifth edition of the american psychiatric association s diagnostic and statistical manual of mental disorders dsm 5 that was published in 2013 includes a new chapter not in dsm iv tr on disruptive impulse control and conduct disorders covering disorders characterized by problems in emotional and behavioral self control it also includes impulse control disorders not elsewhere classified which encompasses intermittent explosive disorder pyromania and kleptomania five behavioural stages characterize impulsivity an impulse growing tension pleasure on acting relief from the urge and finally guilt which may or may not arise
in group favoritism sometimes known as in group – out group bias in group bias or intergroup bias is a pattern of favoring members of one s in group over out group members this can be expressed in evaluation of others in allocation of resources and in many other ways this interaction has been researched by many psychologists and linked to many theories related to group conflict and prejudice the phenomenon is primarily viewed from a social psychology standpoint two prominent theoretical approaches to the phenomenon of in group favoritism are realistic conflict theory and social identity theory realistic conflict theory proposes that intergroup competition and sometimes intergroup conflict arises when two groups have opposing claims to scarce resources in contrast social identity theory posits a psychological drive for positively distinct social identities as the general root cause of in group favoring behavior
in place matrix transposition also called in situ matrix transposition is the problem of transposing an n × m matrix in place in computer memory ideally with o 1 bounded additional storage or at most with additional storage much less than nm typically the matrix is assumed to be stored in row major order or column major order i e contiguous rows or columns respectively arranged consecutively performing an in place transpose in situ transpose is most difficult when n ≠ m i e for a non square rectangular matrix where it involves a complicated permutation of the data elements with many cycles of length greater than 2 in contrast for a square matrix n m all of the cycles are of length 1 or 2 and the transpose can be achieved by a simple loop to swap the upper triangle of the matrix with the lower triangle further complications arise if one wishes to maximize memory locality in order to improve cache line utilization or to operate out of core where the matrix does not fit into main memory since transposes inherently involve non consecutive memory accesses the problem of non square in place transposition has been studied since at least the late 1950 s and several algorithms are known including several which attempt to optimize locality for cache out of core or similar memory related contexts
in system programming isp also called in circuit serial programming icsp is the ability of some programmable logic devices microcontrollers and other embedded devices to be programmed while installed in a complete system rather than requiring the chip to be programmed prior to installing it into the system there are several incompatible in system programming protocols for programming microcontroller devices such as pic microcontrollers avrs and the parallax propeller icsp has been primarily implemented by microchip technology for programming pic and dspic devices the primary advantage of this feature is that it allows manufacturers of electronic devices to integrate programming and testing into a single production phase and save money rather than requiring a separate programming stage prior to assembling the system this may allow manufacturers to program the chips in their own system s production line instead of buying preprogrammed chips from a manufacturer or distributor making it feasible to apply code or design changes in the middle of a production run microcontrollers are typically soldered directly to a printed circuit board and usually do not have the circuitry or space for a large external programming cable to another computer typically chips supporting isp have internal circuitry to generate any necessary programming voltage from the system s normal supply voltage and communicate with the programmer via a serial protocol most programmable logic devices use a variant of the jtag protocol for isp in order to facilitate easier integration with automated testing procedures other devices usually use proprietary protocols or protocols defined by older standards in systems complex enough to require moderately large glue logic designers may implement a jtag controlled programming subsystem for non jtag devices such as flash memory and microcontrollers allowing the entire programming and test procedure to be accomplished under the control of a single protocol an example of devices using isp is the avr line of micro controllers by atmel such as the atmega series
inattentional blindness also known as perceptual blindness is a psychological lack of attention that is not associated with any vision defects or deficits it may be further defined as the event in which an individual fails to recognize an unexpected stimulus that is in plain sight when it simply becomes impossible for one to attend to all the stimuli in a given situation a temporary blindness effect can take place as a result that is individuals fail to see objects or stimuli that are unexpected and quite often salient the term was coined by arien mack and irvin rock in 1992 and was used as the title of their book of the same name published by mit press in 1998 in which they describe the discovery of the phenomenon and include a collection of procedures used in describing it a famous study that demonstrated inattentional blindness asked participants whether or not they noticed a gorilla walking through the scene of a visual task they had been given research on inattentional blindness suggests that the phenomenon can occur in any individual independent of cognitive deficits however recent evidence shows that patients with adhd performed better attentionally when engaging in inattentional blindness tasks than control patients did suggesting that some mental deficits may decrease the effects of this phenomenon recent studies have also looked at age differences and inattentional blindness scores and results show that the effect increases as humans age research also reveals an evolutionary component to inattentional blindness in that we can detect threatening unexpected stimuli more easily than nonthreatening ones numerous experiments have demonstrated that inattentional blindness also has an effect on people s perception
numerous genetic disorders are caused by errors in fatty acid metabolism these disorders may be described as fatty oxidation disorders or as a lipid storage disorders and are any one of several inborn errors of metabolism that result from enzyme defects affecting the ability of the body to oxidize fatty acids in order to produce energy within muscles liver and other cell types some of the more common fatty acid metabolism disorders are
inborn errors of metabolism form a large class of genetic diseases involving congenital disorders of metabolism the majority are due to defects of single genes that code for enzymes that facilitate conversion of various substances substrates into others products in most of the disorders problems arise due to accumulation of substances which are toxic or interfere with normal function or to the effects of reduced ability to synthesize essential compounds inborn errors of metabolism are now often referred to as congenital metabolic diseases or inherited metabolic diseases the term inborn error of metabolism was coined by a british physician archibald garrod 1857 – 1936 in 1908 he is known for work that prefigured the one gene one enzyme hypothesis based on his studies on the nature and inheritance of alkaptonuria his seminal text inborn errors of metabolism was published in 1923
inborn errors of carbohydrate metabolism are inborn error of metabolism that affect the catabolism and anabolism of carbohydrates an example is lactose intolerance carbohydrates account for a major portion of the human diet and are metabolized into three principal monosaccharides galactose fructose and glucose the failure to effectively use these molecules accounts for the majority of the inborn errors of human carbohydrates metabolism
inborn errors of purine – pyrimidine metabolism are a class of inborn error of metabolism disorders specifically affecting purine metabolism and pyrimidine metabolism an example is lesch – nyhan syndrome urine tests may be of use in identifying some of these disorders
inborn errors of renal tubular transport are metabolic disorders which lead to impairment in the ability of solutes such as salts or amino acids to be transported across the brush border of the renal tubule this results in disruptions of renal reabsorption examples of these disorders include iminoglycinuria renal tubular acidosis and gitelman syndrome
an inborn error of steroid metabolism is an inborn error of metabolism due to defects in steroid metabolism a variety of conditions of abnormal steroidogenesis exist due to genetic mutations in the enzymes involved in the process of which include 18 20 desmolase p 450 scc deficiency blocks production of all steroid hormones from cholesterol 3 β hydroxysteroid dehydrogenase type 2 deficiency impairs progestogen and androgen metabolism prevents the synthesis of estrogens glucocorticoids and mineralocorticoids causes androgen deficiency in males and androgen excess in females combined 17 α hydroxylase 17 20 lyase deficiency impairs progestogen metabolism prevents androgen estrogen and glucocorticoid synthesis causes mineralocorticoid excess isolated 17 20 lyase deficiency prevents androgen and estrogen synthesis 21 hydroxylase deficiency prevents glucocorticoid and mineralocorticoid synthesis causes androgen excess in females 11 β hydroxylase type 1 deficiency impairs glucocorticoid and mineralocorticoid metabolism causes glucocorticoid deficiency and mineralocorticoid excess as well as androgen excess in females 11 β hydroxylase type 2 deficiency impairs corticosteroid metabolism results in excessive mineralocorticoid activity 18 hydroxylase deficiency impairs mineralocorticoid metabolism results in mineralocorticoid deficiency 18 hydroxylase overactivity impairs mineralocorticoid metabolism results in mineralocorticoid excess 17 β hydroxysteroid dehydrogenase deficiency impairs androgen and estrogen metabolism results in androgen deficiency in males and androgen excess and estrogen deficiency in females 5 α reductase type 2 deficiency prevents the conversion of testosterone to dihydrotestosterone causes androgen deficiency in males aromatase deficiency prevents estrogen synthesis causes androgen excess in females aromatase excess causes excessive conversion of androgens to estrogens results in estrogen excess in both sexes and androgen deficiency in males in addition several conditions of abnormal steroidogenesis due to genetic mutations in receptors as opposed to enzymes also exist including gonadotropin releasing hormone gnrh insensitivity prevents synthesis of sex steroids by the gonads in both sexes follicle stimulating fsh hormone insensitivity prevents synthesis of sex steroids by the gonads in females merely causes problems with fertility in males luteinizing hormone lh insensitivity prevents synthesis of sex steroids by the gonads in males merely causes problems with fertility in females luteinizing hormone lh oversensitivity causes androgen excess in males resulting in precocious puberty females are asymptomatic no activating mutations of the gnrh receptor in humans have been described in the medical literature and only one of the fsh receptor has been described which presented as asymptomatic
incapacitation in the context of sentencing philosophy is the effect of a sentence in positively preventing rather than merely deterring future offending
incident stress is a condition caused by acute stress which overwhelms a staff person trained to deal with critical incidents such as within the line of duty for first responders emts and other similar personnel if not recognized and treated at onset incident stress can lead to more serious effects of posttraumatic stress disorder
in medicine an incidentaloma is a tumor oma found by coincidence incidentally without clinical symptoms or suspicion like other types of incidental findings it is found during the course of examination and imaging for other reasons it is a common occurrence up to 7 of all patients over 60 may harbor a benign growth often of the adrenal gland which is detected when diagnostic imaging is used for the analysis of unrelated symptoms with the increase of whole body ct scanning as part of health screening programs the chance of finding incidentalomas is expected to increase 37 of patients receiving whole body ct scans have abnormal findings that may need further evaluation since many incidentally found lesions may never cause disease there is a risk of overdiagnosis when faced with an unexpected finding on diagnostic imaging the clinician faces the challenge to prove that the lesion is indeed harmless often some other tests are required to determine the exact nature of an incidentaloma
an incisional hernia is a type of hernia caused by an incompletely healed surgical wound since median incisions in the abdomen are frequent for abdominal exploratory surgery ventral incisional hernias are often also classified as ventral hernias due to their location not all ventral hernias are from incisions as some may be caused by other trauma or congenital problems
inclusion body myositis ibm is an inflammatory muscle disease characterized by slowly progressive weakness and wasting of both distal and proximal muscles most apparent in the muscles of the arms and legs there are two types sporadic inclusion body myositis sibm which is more common and hereditary inclusion body myopathy hibm in sporadic inclusion body myositis my oh sigh tis two processes one autoimmune and the other degenerative appear to occur in the muscle cells in parallel the inflammation aspect is characterized by the cloning of t cells that appear to be driven by specific antigens to invade muscle fibers the degeneration aspect is characterized by the appearance of holes in the muscle cell vacuoles deposits of abnormal proteins within the cells and in filamentous inclusions hence the name inclusion body myositis weakness comes on slowly over months or years and progresses steadily and usually leads to severe weakness and wasting of arm and leg muscles it is more common in men than women patients may become unable to perform activities of daily living and most require assistive devices within 5 to 10 years of symptom onset sibm is not considered a fatal disorder but the risk of serious injury due to falls is increased one common and potentially fatal complication is dysphagia there is no effective treatment for the disease sibm is a rare yet increasingly prevalent disease and is the most common cause of inflammatory myopathy in people over age 50 recent research from australia indicates that the incidence of ibm varies in different populations and ethnic groups the authors found that the current prevalence was 14 9 per million in the overall population with a prevalence of 51 3 per million population in people over 50 years of age as seen in these numbers sibm is an age related disease – its incidence increases with age and symptoms usually begin after 50 years of age it is the most common acquired muscle disorder seen in people over 50 although about 20 of cases display symptoms before the age of 50
inclusion body rhinitis also known as ibr or cytomegalic inclusion disease is a pig disease caused by porcine cytomegalovirus which is a member of the herpesvirus family it is a notifiable disease that is found worldwide it is spread both vertically and horizontally and prevalence is high it is not a zoonosis but the risk to humans that receive pig organ transplants is currently under investigation
inclusive management is a pattern of practices by public managers that facilitate the inclusion of public employees experts the public and politicians in collaboratively addressing public problems or concerns of public interest
incoherent scattering is a type of scattering phenomenon in physics the term is most commonly used when referring to the scattering of an electromagnetic wave usually light or radio frequency by random fluctuations in a gas of particles most often electrons the most well known practical application is known as incoherent scatter radar theory a ground based technique for studying the earth s ionosphere first proposed by professor bill gordon in 1958 a radar beam scattering off electrons in the ionospheric plasma creates an incoherent scatter return the distribution function of the ionospheric electrons is modified by the much slower and more massive positive ions — electron density fluctuations relate to ion temperature mass distribution and motion the incoherent scatter signal allows measurement of electron density ion temperature and electron temperatures ion composition and plasma velocity
in u s business and financial accounting the income is generally defined by gaap and the financial accounting standards board as revenues expenses however many people use it as shorthand for net income which is the amount of money that a company earns after covering all of its costs as well as taxes net income is also called net profit it is calculated as follows 1 the gross income or revenue is tabulated 2 where applicable the cost of goods sold or cost of operations figure is subtracted from the gross income to yield the gross profit 3 all expenses other than the cogs or coo are subsequently subtracted from the gross profit to yield the profit or income or if a negative number the net loss usually written in parentheses more commonly this is reported on the income statement as income or loss before taxes 4 taxes are then subtracted from the pre tax income to give a final net income or net profit or net loss figure 5 the patented blatt double check is then factored in net income or net profit which is not expended to shareholders in the form of dividends becomes part of retained earnings all public companies are required to provide financial statements on a quarterly basis and the income statement of income is one of the most important of these some companies also provide a more rosy financial report of their income with pro forma reporting or ebitda reporting pro forma income is an estimate of how much the company would have earned without including the negative effect of exceptional one time events supposedly in order to show investors how much money the company would have made under normal circumstances if these exceptional one time events had not occurred critics charge that in most cases the one time events are normal business events such as an acquisition of another company or a write off of a cancelled project or division and that pro forma reporting is an attempt to mislead investors by painting a rosy financial picture besides that when discussing results with analysts and shareholders ceos and cfos have a tendency to do even more hypothetical accounting ebitda stands for earnings before interest taxes depreciation and amortisation and is also criticised for being an attempt to mislead investors warren buffett has criticised ebitda reporting famously asking does management think the tooth fairy pays for capital expenditures it is common for some other companies such as real estate investment trusts to present reports using a standard called ffo or funds from operations like ebitda reporting ffo ignores depreciation and amortization this is widely accepted in the industry as real estate values tend to increase rather than decrease over time and many data sites report earnings per share data using ffo
income deficit is the difference between a single person or family s income and its poverty threshold or poverty line when the former is exceeded by the latter data on the income deficits of various members of a population allow for the construction of one type of measurement of income inequality in that population individuals or families that fall below the line are considered to be in poverty whereas families that fall above are not the income deficit is one of two measures that are used to determine a person or family s income distance from the poverty threshold the other being a ratio rather than a difference
critiques of income inequality often refer to a casual chain linking unequal growth to a lessened economy unequal growth concentrates wealth in a small amount on consumers who can only buy so many things as a result the vast majority of people are left with little extra cash for goods and services thus less things are bought and the economy generates less capital than it otherwise might proponents of income inequality often reject the idea of increased government intervention in the markets which is inevitable if income inequality is to be fixed among the most notable arguments for income inequality are those concerning the natural effects of capitalism and the free markets these arguments point out the fact that unequal rewards are natural in a system that is structured for inequality furthermore an opinion that the amount of money earned in a free market system are to be kept by the earner
income inequality is the extent at which household income is unevenly distributed amongst a population in other words it also refers to the gap in income between who can be considered the rich of the population as opposed to the income of those who can be considered the poor of a population income inequality in the philippines is the extent to which income most commonly measured by household or individual is distributed in an uneven manner in the philippines the difference of income between the rich and the poor could cause tension in society and political instability
incontinentia pigmenti ip also known as bloch – siemens syndrome bloch – sulzberger disease bloch – sulzberger syndrome melanoblastosis cutis and nevus pigmentosus systematicus is a genetic disorder that affects the skin hair teeth nails and central nervous system it is named due to its microscopic appearance
incontinentia pigmenti achromians also known as hypomelanosis of ito is a cutaneous condition characterized by various patterns of bilateral or unilateral hypopigmentation following the lines of blaschko though the consistency of the skin findings have led to the term hypomelanosis of ito it actually refers to a group of disorders with various genetic causes including polyploidies and aneuploidies based upon the specifics of the genetic defect the skin findings can be accompanied by a great range of systemic findings these include central nervous system ocular and musculoskeletal defects nonetheless the vast majority of cases are limited to the skin as opposed to incontinentia pigmenti hypomelanosis of ito affects both genders equally
incorporation is a phenomenon by which a grammatical category such as a verb forms a compound with its direct object object incorporation or adverbial modifier while retaining its original syntactic function incorporation is central to many polysynthetic languages such as those found in north america siberia and northern australia however polysynthesis does not necessarily imply incorporation mithun 2009 neither does the presence of incorporation in a language imply that that language is polysynthetic
incremental operating margin is the increase or decrease of income from continuing operations before stock based compensation interest expense and income tax expense between two periods divided by the increase or decrease in revenue between the same two periods
in insurance incurred but not reported ibnr claims is the amount owed by an insurer to all valid claimants who have had a covered loss but have not yet reported it since the insurer knows neither how many of these losses have occurred nor the severity of each loss ibnr is necessarily an estimate the sum of ibnr losses plus reported losses yields an estimate of the total eventual liabilities the insurer will cover known as ultimate losses
independence is a condition of a nation country or state in which its residents and population or some portion thereof exercise self government and usually sovereignty over the territory the opposite of independence is a dependent territory independence does not necessarily mean freedom
indeterminate cell histiocytosis is a cutaneous condition felt to be caused by dermal precursors of langerhans cells
a farmers s cries for help have been ignored as the damaging effects from the absence of credit loans tickles down the population apart from the healthcare of a farmer the lack of access to credit also highly important as almost 80 the farmers own less than a hectare of land the availability of credit allows farmers to be protected from the inflated costs faced in agriculture and also improve the quality of fertilizers and hence the output should the distribution of credit loans improve the indian government would also find it easy to meet production targets and have a better control over prices of grains due to the critical shortage of agricultural output india has to resort to banning grain exports and instead drive up its import bills from wheat coming into the country there has been so much attention focused on the industrial and services sector that the agricultural side has been largely neglected the lack of credit loans coupled with improper government intervention had resulted in the livelihood of the farmers to go downhill as commercial banks are not present in remote locations of india where agriculture is supposed to thrive it becomes an important limitation as the rural population has a strong dependence on it co operative banks which have been set up previously were also doomed to fail as a result of bad loans and a lack of funds these commercial banks have their own set of worries as defaults and crop failures are common in the sector as such they prefer lending out to areas where each farmer owns a much larger proportion of land and also have better irrigation systems however that does not solve the problem as the smaller farmers ’ which forms a majority issues remains unaddressed there should be better banking systems established that is accessible and affordable to every person it is obvious that the benefits of economic growth have not been equally shared among all as the access to credit is not granted to all economic opportunities ought to be created for the marginalized groups to help in poverty reduction and inequality problems further attempts made by the government to expand credit loans have ironically resulted in more cases of poverty than ever the lack of access to formal credit thus places many constraints on agricultural output and also the standards of living for the rural population thereby hindering their path to further economic and social development
indian childhood cirrhosis is a chronic liver disease of childhood characterised by cirrhosis of liver due to deposition of copper in the liver it primarily affects children of 1 – 3 years of age and has a genetic predisposition it had a very high case fatality in the past but has eventually become preventable treatable and is now rare
paid news is a phenomenon in indian media that refers to the systematic engagement of mainstream media outlets in publishing favorable articles in exchange for payment this type of news is typically sponsored by politicians businessmen and celebrities in order to improve their public image or accomplish political goals
although italy and india have maintained important relations since ancient times significant indian migration to italy is a recent phenomenon many indians began immigrating to italy in the early 1990 s when the italian government offered amnesty to illegal migrants following a worker shortage and the numbers have been growing progressively since most came from the punjab and tend to work on dairy farms and in agriculture others have become entrepreneurs and are active in the restaurant and retail fields associated with italy s large tourism industry about half of the total indian migrant population in italy live in the agricultural areas of the central and northern regions of the country especially in the areas around rome and milan most indians have integrated successfully into italian life and local authorities and people are impressed with their contributions to the local economy they have been found to be generally very industrious hard working and law abiding most indians have retained their religious practices namely hinduism and sikhism there are numerous temples and gurdwaras as well as iskcon centres
in mathematics an indicator function or a characteristic function is a function defined on a set x that indicates membership of an element in a subset a of x having the value 1 for all elements of a and the value 0 for all elements of x not in a it is usually denoted by a symbol 1 or i sometimes in boldface or blackboard boldface with a subscript describing the set
indigestion also known as dyspepsia is a condition of impaired digestion symptoms may include upper abdominal fullness heartburn nausea belching or upper abdominal pain people may also experience feeling full earlier than expected when eating dyspepsia is a common problem and is frequently caused by gastroesophageal reflux disease gerd or gastritis in a small minority it may be the first symptom of peptic ulcer disease an ulcer of the stomach or duodenum and occasionally cancer hence unexplained newly onset dyspepsia in people over 55 or the presence of other alarming symptoms may require further investigations functional indigestion previously called nonulcer dyspepsia is indigestion without evidence of an organic disease that is likely to explain the symptoms functional indigestion is estimated to affect about 15 of the general population in western countries
indium mediated allylations imas are important chemical reactions for the formation of carbon – carbon bonds this reaction has two steps first indium inserts itself between the carbon – halogen bond of an allyl halide becoming the organoindium intermediate second this allyl indide intermediate reacts with an electrophile to synthesize one of a wide range of compounds such as carbohydrates and antihelminthic drugs this reaction is depicted in the scheme below two steps of the ima reaction mechanism although this reaction occurs in two steps it is commonly done as a barbier reaction where the indium allyl halide and electrophile are all mixed together in a one pot process ima illustrated as a barbier reaction indium reacts more readily than other metals such as mg pb bi or zn and does not require a promoter or flammable organic solvent to drive the reaction imas have advantages over other carbon bond forming reactions because of their ability to be carried out in water which is cheap and environmentally friendly therefore these reactions represent green chemistry providing a safer alternative to the very common grignard reaction performed with mg reactions yield high stereo and regio selectivity with few by products making it easy to purify the desired product
indium lung is a rare occupational lung disease caused by exposure to respirable indium in the form of indium tin oxide it is classified as an interstitial lung disease diffuse parenchymal lung disease
individual communication services and tariffs is the regulatory protected ability for an identified user to obtain from a communication service provider by a bilateral specific contract a combination of the service and related content at a specific price called a tariff chosen by the user corresponding to a user request specified with a service demand profile and some duration individual service is then the communication service supplied in the way stated above with a request and specification by the user individual tariff is then the price paid by the user for such an individual service
a feature common to all indo european languages is the presence of a verb corresponding to the english verb to be though in some languages it is vestigial it is present nonetheless in atrophied forms or derivatives
induced demand or latent demand is the phenomenon that after supply increases more of a good is consumed this is entirely consistent with the economic theory of supply and demand however this idea has become important in the debate over the expansion of transportation systems and is often used as an argument against widening roads such as major commuter roads this phenomenon called induced traffic is considered by some to be a contributing factor to urban sprawl
in complexity theory and graph theory induced subgraph isomorphism is an np complete decision problem that involves finding a given graph as an induced subgraph of a larger graph
inductive logic programming ilp is a subfield of machine learning which uses logic programming as a uniform representation for examples background knowledge and hypotheses given an encoding of the known background knowledge and a set of examples represented as a logical database of facts an ilp system will derive a hypothesised logic program which entails all the positive and none of the negative examples schema positive examples negative examples background knowledge ⇒ hypothesis inductive logic programming is particularly useful in bioinformatics and natural language processing gordon plotkin and ehud shapiro laid the initial theoretical foundation for inductive machine learning in a logical setting shapiro built its first implementation model inference system in 1981 a prolog program that inductively inferred logic programs from positive and negative examples the term inductive logic programming was first introduced in a paper by stephen muggleton in 1991 muggleton also founded the annual international conference on inductive logic programming introduced the theoretical ideas of predicate invention inverse resolution and inverse entailment muggleton implemented inverse entailment first in the progol system the term inductive here refers to philosophical i e suggesting a theory to explain observed facts rather than mathematical i e proving a property for all members of a well ordered set induction
inductive transfer or transfer learning is a research problem in machine learning that focuses on storing knowledge gained while solving one problem and applying it to a different but related problem for example the abilities acquired while learning to walk presumably apply when one learns to run and knowledge gained while learning to recognize cars could apply when recognizing trucks this area of research bears some relation to the long history of psychological literature on transfer of learning although formal ties between the two fields are limited the earliest cited work on transfer in machine learning is attributed to lorien pratt who formulated the discriminability based transfer dbt algorithm in 1993 in 1997 the journal machine learning published a special issue devoted to inductive transfer and by 1998 the field had advanced to include multi task learning along with a more formal analysis of its theoretical foundations learning to learn edited by sebastian thrun and pratt is a comprehensive overview of the state of the art of inductive transfer at the time of its publication inductive transfer has also been applied in cognitive science with the journal connection sciencepublishing a special issue on reuse of neural networks through transfer in 1996 notably scientists have developed algorithms for inductive transfer in markov logic networks and bayesian networks furthermore researchers have applied techniques for transfer to problems in text classification and spam filtering
industrie und glück german for industry and luck is a pattern of french suited playing cards used to play tarock the name originates from an inscription found on the second trump card this deck was developed during the nineteenth century in the austro hungarian empire after the collapse of the empire in world war i it remained the most widely used tarot deck in central europe and can be found throughout the former parts of the empire though not designed for cartomancy these cards were used in argentine fortune telling decks in the mid 20 th century
inertia is a problem associated with anxiety and autism people who experience inertia often experience feeling paralyzed when they are faced with stressful tasks
inertial response is a function of large synchronous generators which are large synchronous rotating masses and which acts to balance supply and demand for electric power systems typically the electrical grid if there is a power imbalance between electricity supply and demand the rotational frequency of the sychronous generators either speeds up low supply or slows down low demand to instantly rebalance the system this speed up or slow down in sychronous generator speed results in a change in ac frequency ideally within the allowable frequency range of that system i e a 50 hz system may allow a ± 0 5 hz deviation in ac power
in ancient roman culture infamia in not and fama reputation was a loss of legal or social standing as a technical term of roman law infamia was an official exclusion from the legal protections enjoyed by a roman citizen as imposed by a censor or praetor more generally especially during the republic and principate infamia was informal damage to one s esteem or reputation a person who suffered infamia was an infamis plural infames infamia was an inescapable consequence for certain professionals including prostitutes and pimps entertainers such as actors and dancers and gladiators infames could not for instance provide testimony in a court of law they were liable to corporal punishment which was usually reserved for slaves the infamia of entertainers did not exclude them from socializing among the roman elite and entertainers who were stars both men and women sometimes became the lovers of such high profile figures as the dictator sulla and mark antony a passive homosexual who was outed might also be subject to social infamia though if he was a citizen he might retain his legal standing the modern roman catholic church has a similar concept of infamy
infant respiratory distress syndrome irds also called neonatal respiratory distress syndrome respiratory distress syndrome of newborn or increasingly surfactant deficiency disorder sdd and previously called hyaline membrane disease hmd is a syndrome in premature infants caused by developmental insufficiency of pulmonary surfactant production and structural immaturity in the lungs it can also be a consequence of neonatal infection it can also result from a genetic problem with the production of surfactant associated proteins irds affects about 1 of newborn infants and is the leading cause of death in preterm infants the incidence decreases with advancing gestational age from about 50 in babies born at 26 – 28 weeks to about 25 at 30 – 31 weeks the syndrome is more frequent in infants of diabetic mothers and in the second born of premature twins irds is distinct from pulmonary hypoplasia another leading cause of neonatal death that involves respiratory distress
infant swimming is the phenomenon of human babies and toddlers controlling their breath and moving themselves through water this is called the bradycardic response it is not true that babies are born with the ability to swim though they have reflexes that make it look like they are babies aren t old enough to hold their breath intentionally or strong enough to keep their head above water most infants though not all will reflexively hold their breath when submerged to protect their airway and are able to survive immersion in water for short periods of time infants can also be taken to swimming lessons although this may be done to reduce their risk of drowning the effects on drowning risk are not reliable it is extremely important to note that while babies can imitate swimming motions and reflexes they are not yet physically capable of swimming
infantile refsum disease ird also called infantile phytanic acid storage disease is a rare autosomal recessive congenital peroxisomal biogenesis disorder within the zellweger spectrum these are disorders of the peroxisomes that are clinically similar to zellweger syndrome and associated with mutations in the pex family of genes ird is associated with deficient phytanic acid catabolism as is adult refsum disease but they are different disorders that should not be confused
infantile acne is a cutaneous condition that presents at 3 to 6 months of age
infantile acropustulosis also known as acropustulosis of infancy is an intensely itchy vesicopustular eruption of the hands and feet involvement of scabies has been suggested infantile acropustulosis is characterized by itchy papules and vesicles that are similar to those found in scabies mosquito like bites but there is absence of the typical burrowing with s like burrows on the skin and can occur in small babies as opposed to scabies mostly found on children and young adults
infantile apnea is a rare disease that is characterized by cessation of breathing in an infant it may be related to some cases of sudden infant death syndrome sids and can cause cyanosis and bradycardia infantile apnea can be caused by neurological problems or a physical problem in the airway in premature infants it may be treated with caffeine
infantile convulsions and choreoathetosis icca syndrome is a neurological genetic disorder with an autosomal dominant mode of inheritance it is characterized by the association of benign familial infantile epilepsy bife at age 3 – 12 months and later in life with paroxysmal kinesigenic choreoathetosis the icca syndrome was first reported in 1997 in four french families from north western france and provided the first genetic evidence for common mechanisms shared by benign infantile seizures and paroxysmal dyskinesia the epileptic origin of pkc has long been a matter of debates and pd have been classified as reflex epilepsies indeed attacks of pkc and epileptic seizures have several characteristics in common they both are paroxysmal in presentation with a tendency to spontaneous remission and a subset of pkc responds well to anticonvulsants this genetic disease has been mapped to chromosome 16 p q 12 more than 30 families with the clinical characteristics of icca syndrome have been described worldwide so far
infantile cortical hyperostosis is a self limited inflammatory disorder of infants that causes bone changes soft tissue swelling and irritability the disease may be present at birth or occur shortly thereafter the cause is unknown both familial and sporadic forms occur it is also known as caffey disease or caffey s disease
infantile esotropia is an ocular condition of early onset in which one or either eye turns inward it is a specific sub type of esotropia and has been a subject of much debate amongst ophthalmologists with regard to its naming diagnostic features and treatment
infantile free sialic acid storage disease issd is a lysosomal storage disease caused when sialic acid a kind of charged sugar is unable to be transported out of the lysosomal membrane and instead accumulates in the tissue and free sialic acid is excreted in the urine mutations in the slc 17 a 5 solute carrier family 17 anion sugar transporter member 50 gene cause all forms of sialic acid storage disease the slc 17 a 5 gene is located on the long q arm of chromosome 6 between positions 14 and 15 this gene provides instructions for producing a protein called sialin that is located mainly on the membranes of lysosomes compartments in the cell that digest and recycle materials issd is the most severe form of the sialic acid storage diseases babies with this condition have severe developmental delay weak muscle tone hypotonia and failure to gain weight and grow at the expected rate failure to thrive they may have unusual facial features that are often described as coarse seizures bone malformations enlarged liver and spleen hepatosplenomegaly and an enlarged heart cardiomegaly issd is a rare autosomal recessive disorder and affects 1 in 528 000 live births worldwide
infantile hemangiopericytoma also known as congenital hemangiopericytoma is a cutaneous condition characterized by single or multiple dermal and subcutaneous nodules that may be alarmingly large at birth or grow rapidly
infantile neuroaxonal dystrophy is a rare pervasive developmental disorder that primarily affects the nervous system individuals with infantile neuroaxonal dystrophy typically do not have any symptoms at birth but between the ages of about 6 and 18 months they begin to experience delays in acquiring new motor and intellectual skills such as crawling or beginning to speak eventually they lose previously acquired skills
infantile neuronal ceroid lipofuscinoses incl or santavuori disease is a form of ncl and inherited as a recessive autosomal genetic trait the disorder is progressive degenerative and fatal extremely rare worldwide – with approximately 60 official cases reported by 1982 perhaps 100 sufferers in total today – but relatively common in finland due to the local founder effect
infantile speech pedolalia baby talk infantile perseveration or infantilism is a speech disorder persistence of early speech development stage beyond the age when it is normally expected it is characterized by the omission of some sounds and the substitution of standard speech sounds observed in children in early developmental stages despite that people who don t have congenital infantile speech can learn to sing or talk in such manner
infantile systemic hyalinosis or juvenile systemic hyalinosis is an allelic autosomal recessive condition characterized by multiple skin nodules hyaline deposition gingival hypertrophy osteolytic bone lesions and joint contractures
infarction is tissue death necrosis caused by a reduction stoppage in blood flow due to artery blockages mechanical compression rupture or vasoconstriction there may be ischemia a slowing of blood flow or hemorrhage a rupture of an artery causing bleeding the resulting lesion is referred to as an infarct from the latin infarctus stuffed into myocardial infarction is the partial death of heart tissue commonly known as heart attack
infection is the invasion of an organism s body tissues by disease causing agents their multiplication and the reaction of host tissues to these organisms and the toxins they produce infectious disease also known as transmissible disease or communicable disease is illness resulting from an infection infections are caused by infectious agents including viruses viroids prions bacteria nematodes such as parasitic roundworms and pinworms arthropods such as ticks mites fleas and lice fungi such as ringworm and other macroparasites such as tapeworms and other helminths hosts can fight infections using their immune system mammalian hosts react to infections with an innate response often involving inflammation followed by an adaptive response specific medications used to treat infections include antibiotics antivirals antifungals antiprotozoals and antihelminthics infectious diseases resulted in 9 2 million deaths in 2013 about 17 of all deaths the branch of medicine that focuses on infections is referred to as infectious disease
an infectious bone disease is a bone disease primarily associated with an infection an example is osteomyelitis
infectious bovine keratoconjunctivitis or ibk is a veterinary infection of cattle caused by moraxella bovis a gram negative β haemolytic aerobic rod shaped bacterium it is spread by direct contact or by flies serving as vectors it is the most common ocular disease of cattle mostly beef ibk is similar to human pink eye and causes severe infection of the conjunctiva edema corneal opacity and ulceration this disease is highly contagious and occurs worldwide younger animals are more susceptible but recovery with minimal damage is usual if they are treated early the disease is also known as pinkeye new forest eye or blight
infectious canine hepatitis is an acute liver infection in dogs caused by canine adenovirus type 1 cav 1 cav 1 also causes disease in wolves coyotes and bears and encephalitis in foxes the virus is spread in the faeces urine blood saliva and nasal discharge of infected dogs it is contracted through the mouth or nose where it replicates in the tonsils the virus then infects the liver and kidneys the incubation period is 4 to 7 days symptoms include fever depression loss of appetite coughing and a tender abdomen corneal edema and signs of liver disease such as jaundice vomiting and hepatic encephalopathy may also occur severe cases will develop bleeding disorders which can cause hematomas to form in the mouth death can occur secondary to this or the liver disease however most dogs recover after a brief illness although chronic corneal edema and kidney lesions may persist diagnosis is made by recognizing the combination of symptoms and abnormal blood tests that occur in infectious canine hepatitis a rising antibody titer to cav 1 is also seen the disease can be confused with canine parvovirus because both will cause a low white blood cell count and bloody diarrhea in young unvaccinated dogs treatment is symptomatic most dogs recover spontaneously without treatment prevention is through vaccination atcvet code qi 07 aa 05 who and various combination vaccines most combination vaccines for dogs contain a modified canine adenovirus type 2 cav 2 is one of the causes of respiratory infections in dogs but it is similar enough to cav 1 that vaccine for one creates immunity for both cav 2 vaccine is much less likely to cause side effects than cav 1 vaccine one study has shown the vaccine to have a duration of immunity of at least four years cav 1 is destroyed in the environment by steam cleaning and quaternary ammonium compounds otherwise the virus can survive in the environment for months in the right conditions it can also be released in the urine of a recovered dog for up to a year
infectious dose id is the amount of pathogen measured in number of microorganisms required to cause an infection in the host usually it varies according to the pathogenic agent and the consumer s age and overall health
infectious hypodermal and hematopoietic necrosis ihhn is a viral disease of penaeid shrimp that causes mass mortality up to 90 among the western blue shrimp penaeus stylirostris and severe deformations in the pacific white shrimp p vannamei it occurs in pacific farmed and wild shrimp but not in wild shrimp on the atlantic coast of the americas the shrimp farming industry has developed several broodstocks of both p stylirostris and p vannamei that are resistant against ihhn infection the disease is caused by a single stranded dna virus simply called ihhn virus the smallest of the known penaeid shrimp viruses 22 nm
an infectious intracranial aneurysm iia also called mycotic aneurysm is a cerebral aneurysm that is caused by infection of the cerebral arterial wall
infectious mononucleosis im also known as mono or glandular fever is an infection commonly caused by the epstein – barr virus ebv most people are infected by the virus as children when the disease produces little or no symptoms in young adults the disease often results in fever sore throat enlarged lymph nodes in the neck and feeling tired most people get better in two to four weeks however feeling tired may last for months the liver or spleen may also become swollen in less than one percent of cases splenic rupture may occur infectious mononucleosis is usually caused by epstein – barr virus ebv also known as human herpesvirus 4 which is a member of the herpes virus family a few other viruses may also cause the disease it is primarily spread through saliva but can rarely be spread through semen or blood spread may occur by objects such as drinking glasses or toothbrushes those who are infected can spread the disease weeks before symptoms develop mono is primarily diagnosed based on the symptoms and can be confirmed with blood tests for specific antibodies another typical finding is increased blood lymphocytes of which more than 10 are atypical the monospot test is not very useful there is no vaccine for ebv prevention is by not sharing personal items or kissing those infected mono generally gets better on its own recommendations include drinking enough fluids getting sufficient rest and taking pain medications such as paracetamol acetaminophen and ibuprofen mono most commonly affects those between the ages of 15 to 24 years in the developed world in the developing world people are more often infected in early childhood when the symptoms are less in those between 16 and 20 it is the cause of about 8 of sore throats about 45 out of 100 000 people develop mono each year in the united states nearly 95 of people have been infected by the time they are adults the disease occurs equally at all times of the year mononucleosis was first described in the 1920 s and is colloquially known as the kissing disease
infectious necrotic hepatitis is a disease of large animals especially sheep caused by clostridium novyi infection the primary infection is intestinal and transferred by the faecal oral route spores of c novyi escape from the gut and lodge in the liver where they remain dormant until some injury creates anaerobic conditions for them to germinate causing local necrosis and widespread damage to the microvascular system resulting in subcutaneous bleeding and blackening of the skin hence the common name black disease
infectious pancreatic necrosis ipn is a severe viral disease of salmonid fish it is caused by infectious pancreatic necrosis virus which is a member of the birnaviridae family this disease mainly affects young salmonids such as trout or salmon of less than six months although adult fish may carry the virus without showing symptoms resistance to infection develops more rapidly in warmer water it is highly contagious and found worldwide but some regions have managed to eradicate or greatly reduce the incidence of disease the disease is normally spread horizontally via infected water but spread also occurs vertically it is not a zoonosis
infectious salmon anemia or anaemia isa is a viral disease of atlantic salmon salmo salar that affects fish farms in canada norway scotland and chile causing severe losses to infected farms the disease is listed as a non exotic disease of the eu and is therefore watched closely by the european community reference laboratory for fish diseases
infective endocarditis is a form of endocarditis it is an inflammation of the inner tissues of the heart the endocardium usually of the valves it is caused by infectious agents or pathogens which are largely bacterial but a few other organisms can also be responsible before the age of modern antibiotics it was almost universally fatal the valves of the heart do not receive any dedicated blood supply as a result defensive immune system mechanisms such as white blood cells cannot directly reach the valves via the bloodstream if an organism such as bacteria attaches to a valve surface and forms a vegetation the host s immune response is blunted the lack of blood supply to the valves also has implications for treatment since drugs also have difficulty reaching the infected area normally blood flows smoothly through these valves if they have been damaged — from rheumatic fever for example — the risk of bacterial attachment is increased
in epidemiology infectivity is the ability of a pathogen to establish an infection more specifically infectivity is a pathogen s capacity for horizontal transmission that is how frequently it spreads among hosts that are not in a parent child relationship the measure of infectivity in a population is called incidence infectivity has been shown to positively correlate with virulence this means that as a pathogen s ability to infect a greater number of hosts increases so does the level of harm it brings to the host a pathogen s infectivity is subtly but importantly different from its transmissibility which refers to a pathogen s capacity to pass from parent to child
inferior vena cava syndrome ivcs is a result of obstruction of the inferior vena cava it can be caused by invasion or compression by a pathological process or by thrombosis in the vein itself it can also occur during pregnancy pregnancy can lead to problems with blood return due to high venous pressure in the lower limbs failure of blood return to the heart decreased cardiac output due to obstructions in inferior vena cava sudden rise in venous pressure which can lead to placental separation and a decrease in renal function all of these issues can arise from lying in the supine position during late pregnancy which can cause compression of the inferior vena cava symptoms of late pregnancy inferior vena cava syndrome consist of intense pain in the right hand side muscle twitching drop of blood pressure and fluid retention
an inferiority complex is a lack of self worth a doubt and uncertainty and feelings of not measuring up to standards it is often subconscious and is thought to drive afflicted individuals to overcompensate resulting either in spectacular achievement or extreme asocial behavior in modern literature the preferred terminology is lack of covert self esteem for many it is developed through a combination of genetic personality characteristics and personal experiences
infertility is the inability of a person animal or plant to reproduce by natural means it is usually not the natural state of a healthy adult organism except notably among certain eusocial species mostly haplodiploid insects in humans infertility may describe a woman who is unable to conceive as well as being unable to carry a pregnancy to full term there are many biological and other causes of infertility including some that medical intervention can treat estimates from 1997 suggest that worldwide between three and seven per cent of all couples or women have an unresolved problem of infertility many more couples however experience involuntary childlessness for at least one year estimates range from 12 to 28 20 30 of infertility cases are due to male infertility 20 35 are due to female infertility and 25 40 are due to combined problems in both parts in 10 20 of cases no cause is found the most common cause of female infertility is ovulatory problems which generally manifest themselves by sparse or absent menstrual periods male infertility is most commonly due to deficiencies in the semen and semen quality is used as a surrogate measure of male fecundity women who are fertile experience a natural period of fertility before and during ovulation and they are naturally infertile during the rest of the menstrual cycle fertility awareness methods are used to discern when these changes occur by tracking changes in cervical mucus or basal body temperature
infestation is the state of being invaded or overrun by pests or parasites it can also refer to the actual organisms living on or within a host
infiltration analgesia is deposition of an analgesic drug close to the apex of a tooth so that it can diffuse to reach the nerve entering the apical foramina
the infinite bobs is an effect used in demos that show a lot of simple sprites moving on the screen at the same time usually on computers like amiga atari st or commodore 64 which featured a limited number of sprites the effect is achieved thanks to multiple buffers actually only one sprite is used and it is rendered only once per frame but unlike most of software sprite engine nothing is done to preserve the background or to erase the sprite from the old position so moving a sprite leaves a trail behind it video buffers are rotated and each frame use a different buffer from previous so the sprite will be drawn in a slightly different position in all buffers when all buffers have been used the first one is used a second time without cleaning it so the sprite is rendered on a buffer that already contain the sprite image but since some other frames have been rendered in the meantime the two pictures don t overlap by flipping all the buffers all instances of the sprites appear like they are moving with that trick there is no limit to the number of sprites that can be rendered since only one sprite needs to be moved animated and rendered the speed does not change when the screen is empty or when thousands of sprites are already moving of course all the sprites need to follow the same path mimicking the first one the only one that is actually moved by the program so that trick cannot be used in particle systems or in shoot em ups where each sprite needs its own vector
inflammatory aortic aneurysm iaa also known as inflammatory abdominal aortic aneurysm iaaa is a type of abdominal aortic aneurysm aaa where the walls of the aneurysm become thick and inflamed similar to aaa iaa occurs in the abdominal region iaa is closely associated and believed to be a response to and extensive peri anuerysmal fibrosis which is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process iaa accounts for 5 10 of aortic aneurysms iaa is occurs mainly in a population that is on average younger by 10 years than most aaa patients some common symptoms of iaa may include back pain abdominal tenderness fevers weight loss or elevated erythrocyte sedimentation rate esr levels corticosteroids and other immunosuppressive drugs have been found to decrease symptoms and the degree of peri aortic inflammation and fibrosis
inflammatory bowel disease ibd is a group of inflammatory conditions of the colon and small intestine crohn s disease and ulcerative colitis are the principal types of inflammatory bowel disease it is important to note that not only does crohn s disease affect the small intestine and large intestine it can also affect the mouth esophagus stomach and the anus whereas ulcerative colitis primarily affects the colon and the rectum
inflammatory breast cancer is one of the most aggressive types of breast cancer that can occur in women of any age and extremely rarely in men it is called inflammatory because it frequently presents with symptoms resembling an inflammation despite the name whether inflammation contributes to the development of inflammatory breast cancer remains an area of ongoing research however it can present with very variable signs and symptoms frequently without detectable tumors and therefore is often not detected by mammography or ultrasound typical presentation is rapid swelling sometimes associated by skin changes peau d orange and nipple retraction other symptoms include rapid increase in breast size redness persistent itching skin hot to touch ibc often initially resembles mastitis only about 50 75 cases have the typical presentation symptoms can be completely atypical such as acute central venous thrombosis as the sole presenting symptom ibc makes up only a small percentage of breast cancer cases 1 6 in the usa ibc is often diagnosed in younger women although average age of presentation does not differ much from other kinds of breast cancer average age 57 years african americans are usually diagnosed at younger ages than caucasian women and also have a higher risk of getting ibc recent advances in therapy have improved the prognosis considerably and at least one third of women will survive the diagnosis by 10 years or longer
inflammatory fibroid polyp abbreviated ifp is a benign abnormal growth of tissue projecting into the lumen of the gastrointestinal tract
inflammatory linear verrucous epidermal nevus ilven is a rare disease of the skin that presents as multiple discrete red papules that tend to coalesce into linear plaques that follow the lines of blaschko the plaques can be slightly warty psoriaform or scaly eczema like ilven is caused by somatic mutations that result in genetic mosaicism there is no cure but different medical treatments can alleviate the symptoms
inflammatory myeloblastic tumor imt also known as an inflammatory pseudotumor is a rare benign tumor occurring in the liver and or bile ducts
inflammatory myofibroblastic tumour is a lesional pattern of inflammatory pseudotumour as plasma cell granuloma it is abbreviated imt
inflammatory myopathy inflammatory muscle disease or myositis is disease featuring weakness and inflammation of muscles and in some types muscle pain the cause of much inflammatory myopathy is unknown idiopathic and such cases are classified according to their symptoms and signs and electromyography mri and laboratory findings it can also be associated with underlying cancer the main classes of idiopathic inflammatory myopathy are polymyositis pm dermatomyositis dm and inclusion body myositis ibm
inflammatory papillary hyperplasia also termed palatal papillomatosis palatal epithelial hyperplasia and denture papillomatosis is a hyperplasia overgrowth of soft tissue usually beneath a denture it is associated with poor denture hygiene denture overuse and ill fitting dentures it is a closely related condition to inflammatory fibrous hyperplasia epulis fissuratum but the appearance and location differs
in economics inflation is a sustained increase in the general price level of goods and services in an economy over a period of time when the price level rises each unit of currency buys fewer goods and services consequently inflation reflects a reduction in the purchasing power per unit of money – a loss of real value in the medium of exchange and unit of account within the economy a chief measure of price inflation is the inflation rate the annualized percentage change in a general price index usually the consumer price index over time the opposite of inflation is deflation inflation affects economies in various positive and negative ways the negative effects of inflation include an increase in the opportunity cost of holding money uncertainty over future inflation which may discourage investment and savings and if inflation were rapid enough shortages of goods as consumers begin hoarding out of concern that prices will increase in the future positive effects include reducing the real burden of public and private debt keeping nominal interest rates above zero so that central banks can adjust interest rates to stabilize the economy and reducing unemployment due to nominal wage rigidity economists generally believe that high rates of inflation and hyperinflation are caused by an excessive growth of the money supply however money supply growth does not necessarily cause inflation some economists maintain that under the conditions of a liquidity trap large monetary injections are like pushing on a string views on which factors determine low to moderate rates of inflation are more varied low or moderate inflation may be attributed to fluctuations in real demand for goods and services or changes in available supplies such as during scarcities however the consensus view is that a long sustained period of inflation is caused by money supply growing faster than the rate of economic growth today most economists favor a low and steady rate of inflation low as opposed to zero or negative inflation reduces the severity of economic recessions by enabling the labor market to adjust more quickly in a downturn and reduces the risk that a liquidity trap prevents monetary policy from stabilizing the economy the task of keeping the rate of inflation low and stable is usually given to monetary authorities generally these monetary authorities are the central banks that control monetary policy through the setting of interest rates through open market operations and through the setting of banking reserve requirements
an inflationary gap in economics is the amount by which the actual gross domestic product exceeds potential full employment gdp it is one type of output gap the other being a recessionary gap
inflicted insight is a possible consequence for subjects participating in certain kinds of research it occurs when the subject is given insight into his flaws through his or her participation in an experiment often unexpectedly or causing emotional pain it is especially likely in social and psychological research and especially when that research involves deception of the subject by the researcher the milgram experiment is a well known example of an experiment with a very high potential for inflicted insight through their participation in the experiment many subjects realized that they were capable of committing acts of extreme violence on other human beings after having this realization many subjects experienced prolonged symptoms of anxiety however 84 percent of former participants surveyed later said they were glad or very glad to have participated deceptive debriefing is one method for avoiding inflicted insight in psychological experiments although it is considered ethically questionable in and of itself the american psychological association s guidelines for ethical experimentation strongly discourage experiments where deceptive debriefing is the only alternative to inflicted insight however such experiments may be deemed ethically acceptable if they are counterbalanced by other ethical concerns
flu and grippe redirect here for other uses see flu disambiguation and grippe disambiguation influenza commonly known as the flu is an infectious disease caused by an influenza virus symptoms can be mild to severe the most common symptoms include a high fever runny nose sore throat muscle pains headache coughing and feeling tired these symptoms typically begin two days after exposure to the virus and most last less than a week the cough however may last for more than two weeks in children there may be nausea and vomiting but these are not common in adults nausea and vomiting occur more commonly in the unrelated infection gastroenteritis which is sometimes inaccurately referred to as stomach flu or 24 hour flu complications of influenza may include viral pneumonia secondary bacterial pneumonia sinus infections and worsening of previous health problems such as asthma or heart failure three types of influenza viruses affect people called type a type b and type c usually the virus is spread through the air from coughs or sneezes this is believed to occur mostly over relatively short distances it can also be spread by touching surfaces contaminated by the virus and then touching the mouth or eyes a person may be infectious to others both before and during the time they are showing symptoms the infection may be confirmed by testing the throat sputum or nose for the virus a number of rapid tests are available however people may still have the infection if the results are negative a type of polymerase chain reaction that detects the virus s rna is more accurate frequent hand washing reduces the risk of infection because the virus is inactivated by soap wearing a surgical mask is also useful yearly vaccinations against influenza are recommended by the world health organization for those at high risk the vaccine is usually effective against three or four types of influenza it is usually well tolerated a vaccine made for one year may not be useful in the following year since the virus evolves rapidly antiviral drugs such as the neuraminidase inhibitor oseltamivir among others have been used to treat influenza their benefits in those who are otherwise healthy do not appear to be greater than their risks no benefit has been found in those with other health problems influenza spreads around the world in a yearly outbreak resulting in about three to five million cases of severe illness and about 250 000 to 500 000 deaths in the northern and southern parts of the world outbreaks occur mainly in winter while in areas around the equator outbreaks may occur at any time of the year death occurs mostly in the young the old and those with other health problems larger outbreaks known as pandemics are less frequent in the 20 th century three influenza pandemics occurred spanish influenza in 1918 asian influenza in 1958 and hong kong influenza in 1968 each resulting in more than a million deaths the world health organization declared an outbreak of a new type of influenza a h 1 n 1 to be a pandemic in june 2009 influenza may also affect other animals including pigs horses and birds
influenza like illness ili also known as acute respiratory infection ari and flu like syndrome symptoms is a medical diagnosis of possible influenza or other illness causing a set of common symptoms symptoms commonly include fever shivering chills malaise dry cough loss of appetite body aches and nausea typically in connection with a sudden onset of illness in most cases the symptoms are caused by cytokines released by immune system activation and are thus relatively non specific common causes of ili include the common cold and influenza which tends to be less common but more severe than the common cold less common causes include side effects of many drugs and manifestations of many other diseases
h 10 n 7 is a subtype of the species influenza a virus sometimes called bird flu virus in 2004 in egypt h 10 n 7 was reported for the first time in humans it caused illness in two one year old infants residents of ismaillia egypt one child ’ s father a poultry merchant the first reported h 10 n 7 outbreak in the us occurred in minnesota on two turkey farms in 1979 and on a third in 1980 the clinical signs ranged from severe with a mortality rate as high as 31 to subclinical antigenically indistinguishable viruses were isolated from healthy mallards on a pond adjacent to the turkey farms
influenza a h 1 n 1 virus is the subtype of influenza a virus that was the most common cause of human influenza flu in 2009 and is associated with the 1918 outbreak known as the spanish flu it is an orthomyxovirus that contains the glycoproteins haemagglutinin and neuraminidase for this reason they are described as h 1 n 1 h 1 n 2 etc depending on the type of h or n antigens they express with metabolic synergy haemagglutinin causes red blood cells to clump together and binds the virus to the infected cell neuraminidase are a type of glycoside hydrolase enzyme which help to move the virus particles through the infected cell and assist in budding from the host cells some strains of h 1 n 1 are endemic in humans and cause a small fraction of all influenza like illness and a small fraction of all seasonal influenza h 1 n 1 strains caused a small percentage of all human flu infections in 2004 – 2005 other strains of h 1 n 1 are endemic in pigs swine influenza and in birds avian influenza in june 2009 the world health organization who declared the new strain of swine origin h 1 n 1 as a pandemic this strain is often called swine flu by the public media this novel virus spread worldwide and had caused about 17 000 deaths by the start of 2010 on august 10 2010 the world health organization declared the h 1 n 1 influenza pandemic over saying worldwide flu activity had returned to typical seasonal patterns
h 1 n 2 is a subtype of the species influenza a virus sometimes called bird flu virus it is currently endemic in both human and pig populations h 1 n 1 h 1 n 2 and h 3 n 2 are the only known influenza a virus subtypes currently circulating among humans the virus does not cause more severe illness than other influenza viruses and no unusual increases in influenza activity have been associated with it
h 2 n 2 is a subtype of the influenza a virus h 2 n 2 has mutated into various strains including the asian flu strain now extinct in the wild h 3 n 2 and various strains found in birds it is also suspected of causing a human pandemic in 1889 the geographic spreading of the 1889 russian flu have been studied and published
h 2 n 3 is a subtype of the influenza a virus its name derives from the forms of the two kinds of proteins on the surface of its coat hemagglutinin h and neuraminidase n h 2 n 3 viruses can infect birds and mammalsit is also known as the common cold
h 3 n 1 is a subtype of the species influenza a virus mostly affecting pigs the known subtypes of influenza a virus that create influenza in pigs and are endemic in pigs are h 1 n 1 h 1 n 2 h 3 n 1 and h 3 n 2
influenza a virus subtype h 3 n 2 a h 3 n 2 is a subtype of viruses that causes influenza flu h 3 n 2 viruses can infect birds and mammals in birds humans and pigs the virus has mutated into many strains h 3 n 2 is increasingly abundant in seasonal influenza which kills an estimated 36 000 people in the united states each year
h 3 n 8 is a subtype of the species influenza a virus that is endemic in birds horses and dogs in 2011 it was reported to have been found in seals cats have been experimentally infected with the virus leading to clinical signs shedding of the virus and infection of other cats
influenza a virus subtype h 5 n 1 also known as a h 5 n 1 or simply h 5 n 1 is a subtype of the influenza a virus which can cause illness in humans and many other animal species a bird adapted strain of h 5 n 1 called hpai a h 5 n 1 for highly pathogenic avian influenza virus of type a of subtype h 5 n 1 is the highly pathogenic causative agent of h 5 n 1 flu commonly known as avian influenza bird flu it is enzootic maintained in the population in many bird populations especially in southeast asia one strain of hpai a h 5 n 1 is spreading globally after first appearing in asia it is epizootic an epidemic in nonhumans and panzootic affecting animals of many species especially over a wide area killing tens of millions of birds and spurring the culling of hundreds of millions of others to stem its spread many references to bird flu and h 5 n 1 in the popular media refer to this strain according to the world health organization and united nations food and agriculture organization h 5 n 1 pathogenicity is gradually continuing to rise in endemic areas but the avian influenza disease situation in farmed birds is being held in check by vaccination and so far there is no evidence of sustained human to human transmission of the virus eleven outbreaks of h 5 n 1 were reported worldwide in june 2008 in five countries china egypt indonesia pakistan and vietnam compared to 65 outbreaks in june 2006 and 55 in june 2007 the global hpai situation significantly improved in the first half of 2008 but the fao reports that imperfect disease surveillance systems mean that occurrence of the virus remains underestimated and underreported in july 2013 the who announced a total of 630 confirmed human cases which resulted in the deaths of 375 people since 2003 several h 5 n 1 vaccines have been developed and approved and stockpiled by a number of countries including the united states in its national stockpile britain france canada and australia for use in an emergency research has shown that a highly contagious strain of h 5 n 1 one that might allow airborne transmission between mammals can be reached in only a few mutations raising concerns about a pandemic and bioterrorism
h 5 n 2 is a subtype of the species influenzavirus a avian influenza virus or bird flu virus the subtype infects a wide variety of birds including chickens ducks turkeys falcons and ostriches affected birds usually do not appear ill and the disease is often mild as avian influenza viral subtypes go some variants of the subtype are much more pathogenic than others and outbreaks of high path h 5 n 2 result in the culling of thousands of birds in poultry farms from time to time it appears that people who work with birds can be infected by the virus but suffer hardly any noticeable health effects even people exposed to the highly pathogenic h 5 n 2 variety that killed ostrich chicks in south africa only seem to have developed conjunctivitis or a perhaps a mild respiratory illness there is no evidence of human to human spread of h 5 n 2
h 5 n 3 is a subtype of the species influenza a virus sometimes called bird flu virus h 5 n 3 was identified in quebec in august 2005 and in sweden in october 2005 2009 h 5 n 3 virus was identified at a la garnache farm in france in late january 90 birds were found dead between 29 january 2009 and 31 january 2009 the remaining stock of 4 932 birds was culled on 1 february 2009 germany 102 ostriches and 28 chickens in a farm blumberg must be slaughtered suspicion of avian influenza the samples have shown that it is an h 5 n 3 virus an influenza a virus
h 5 n 6 is a subtype of the species influenza a virus sometimes called bird flu virus four known cases three fatal have occurred in humans as of july 12 2015
h 5 n 8 is a subtype of the influenza a virus sometimes called bird flu virus although h 5 n 8 is considered one of the lower pathogenic subtypes it is beginning to become more so many times h 5 n 8 is used as an incubator for the highly pathogenic h 1 n 1
h 5 n 9 is a subtype of the species influenza a virus sometimes called bird flu virus a highly pathogenic strain of h 5 n 9 caused a minor flu outbreak in 1966 in ontario and manitoba canada in turkeys
influenza a virus subtype h 6 n 1 also known as h 6 n 1 is a subtype of the influenza a virus it has only infected one person a woman in taiwan who recovered known to infect eurasian teal it is closely related to subtype h 5 n 1
h 7 n 1 is a subtype of the species influenza a virus sometimes called bird flu virus a highly pathogenic strain of it caused a flu outbreak with significant spread to numerous farms resulting in great economic losses in 1999 in italy in turkeys
h 7 n 2 is a subtype of the species influenza a virus this subtype is one of several sometimes called bird flu virus a cdc study following outbreaks of h 7 n 2 in commercial poultry farms in western virginia in 2002 concluded an important factor contributing to rapid early spread of ai virus infection among commercial poultry farms during this outbreak was disposal of dead birds via rendering off farm because of the highly infectious nature of ai virus and the devastating economic impact of outbreaks poultry farmers should consider carcass disposal techniques that do not require off farm movement such as burial composting or incineration one person in virginia united states in 2002 and one person in new york united states in 2003 were found to have serologic evidence of infection from h 7 n 2 both fully recovered an analysis of the new york 2003 case concluded that the h 7 n 2 virus responsible could be evolving toward the same strong sugar binding properties of the three worldwide viral pandemics in 1918 1957 and 1968 human flus and bird flus differ in the molecules they are good at binding with because mammals and birds differ in the molecules on the cell surface to be bound with humans have very few cells with the bird sugar on its cell surface a study with ferrets showed that this h 7 n 2 strain could be passed from mammal to mammal in february 2004 an outbreak of low pathogenic avian influenza lpai a h 7 n 2 was reported on 2 chicken farms in delaware and in four live bird markets in new jersey supplied by the same farms in march 2004 surveillance samples from a flock of chickens in maryland tested positive for lpai h 7 n 2 it is likely that this was the same strain on 24 may 2007 an outbreak of h 7 n 2 was confirmed at a poultry farm near corwen in wales from tests on chickens that died from h 7 n 2 the owners of the conwy farm bought 15 rhode island red chickens two weeks prior but all died from h 7 n 2 the 32 other poultry at the site were slaughtered a one kilometer exclusion zone was put in force around the property in which birds and bird products cannot be moved and bird gathering can only take place under licence nine people who were associated with the infected or dead poultry and reported flu like symptoms were tested four tested positive for evidence of infection from h 7 n 2 and were successfully treated for mild flu in early june it was discovered that the virus had spread to a poultry farm 70 miles 113 km away near st helens in north west england all the poultry at the farm were slaughtered and a 1 km exclusion zone imposed
h 7 n 3 is a subtype of the species influenza a virus sometimes called bird flu virus in north america the presence of h 7 n 3 was confirmed at several poultry farms in british columbia in february 2004 flocks were culled to halt the spread of the virus two humans both poultry workers were infected and had symptoms including conjunctivitis and mild influenza like illness both fully recovered and were treated with oseltamivir in 1963 h 7 n 3 was first found in britain in turkeys for the first time since 1979 h 7 n 3 was found in the uk in april 2006 it infected birds and one poultry worker whose only symptom was conjunctivitis in a norfolk england witford lodge farm oseltamivir was used for prevention and 35 000 chickens were culled in 2005 h 7 n 3 was detected in migratory bird droppings in taiwan on september 27 2007 another outbreak of h 7 n 3 was detected in a poultry operation in saskatchewan canada the canadian food inspection agency has announced the euthanization of the flock and the disinfection of all building materials and equipment in contact with the birds or their droppings in june 2012 an outbreak was found on about 10 farms in jalisco mexico of the over 6 million birds checked 1 7 million were found to be sick the area primarily produces layers and supplies eggs the virus is not transmitted from hens to their eggs
h 7 n 4 is a subtype of the species influenza a virus sometimes called bird flu virus a highly pathogenic strain of it caused a minor flu outbreak in 1997 in new south wales australia in chicken
h 7 n 7 is a subtype of influenza a virus a genus of orthomyxovirus the viruses responsible for influenza highly pathogenic strains hpai and low pathogenic strains lpai exist h 7 n 7 can infect humans birds pigs seals and horses in the wild and has infected mice in laboratory studies this unusual zoonotic potential represents a pandemic threat in 2003 89 people in the netherlands were confirmed to have been infected by h 7 n 7 following an outbreak in poultry on approximately 255 farms one death was recorded a veterinarian who had been testing chickens for the virus and all infected flocks were culled most affected people had mild symptoms including conjunctivitis antibodies were found in over half of 500 people tested according to the final official report by the dutch government as at least 50 of the people exposed to infected poultry had h 7 antibodies detectable with the modified assay it was estimated that avian influenza a h 7 n 7 virus infection occurred in at least 1000 and perhaps as many as 2000 people the seroprevalence of h 7 antibodies in people without contact with infected poultry but with close household contact to an infected poultry worker was 59 this suggests that the population at risk for avian influenza was not limited to those with direct contact to infected poultry and that person to person transmission may have occurred on a large scale final analysis of dutch avian influenza outbreaks reveals much higher levels of transmission to humans than previously thought in august 2006 low pathogenic lp h 7 n 7 was found during routine testing at a poultry farm in voorthuizen in the central netherlands as a precautionary measure 25 000 chickens were culled from voorthuizen and surrounding farms in june 2008 high pathogenic hp h 7 n 7 was confirmed on a 25 000 bird laying unit at shenington england probably derived from a pre existing low pathogenic variety farmers guardian reported a 2 5 per cent increased mortality in one shed and a reduction in egg production recorded two weeks before a large number of deaths on 2 june that led to the diagnosis of hp h 7 n 7 on 4 june in october 2009 high pathogenic hp h 7 n 7 was confirmed on a farm in almoguera guadalajara spain hong kong announced that it would suspend the import of poultry from spain in august 2013 high pathogenic hp h 7 n 7 was found in markets in wenzhou zhejiang province in china when testing for h 7 n 9 in july 2015 high pathogenic hp h 7 n 7 was confirmed on a poultry farm in lancashire england
h 9 n 2 is a subtype of the species influenza a virus bird flu virus over the years the h 9 n 2 influenza strain caused illness in several children aged nine months to 5 years in hong kong with the latest occurring in december 2009
information excellence is the ability of an organization to use information in an optimal way to achieve their own competitive advantages looking at the supply of information as a customer oriented process in terms of business performance excellence means the ability of an information provider broadcaster the interests of its customer information to know best and their related requirements to satisfy optimally from the perspective of the customer information information excellence pursued the objective of enabling the customer to develop its information needs specifically and consistently under selection to satisfy any information provider
the information explosion is the rapid increase in the amount of published information or data and the effects of this abundance as the amount of available data grows the problem of managing the information becomes more difficult which can lead to information overload the online oxford english dictionary indicates use of the phrase in a march 1964 new statesman article the new york times first used the phrase in its editorial content in an article by walter sullivan on june 7 1964 in which he described the phrase as much discussed pe 11 the earliest use of the phrase seems to have been in an ibm advertising supplement to the new york times published on april 30 1961 and by frank fremont smith director of the american institute of biological sciences interdisciplinary conference program in an april 1961 article in the aibs bulletin p 18 techniques to gather knowledge from an overabundance of electronic information e g data fusion may help in data mining have existed since the 1970 s
information hypothesis of conditioned reinforcement berlyne 1960 bloomfield 1972 rachlin 1976 states that the conditioned reinforcing strength of a stimulus is a function of its informativeness about the availability of primary reinforcement in other words the more uncertainty about the reinforcement the stimulus reduces the more effective a conditioned reinforcer it will be hence this hypothesis has also been called the uncertainty reduction hypothesis
an important factor to be considered with old age is cognitive decline thus information processing technologies need to be centered on factors that define cognition this article highlights some of the important conceptual models and theories that govern design of such systems the main focus is to look at the different information processing technologies that are presently used for enabling better functional performance as the nation ’ s baby boomers grow older there exists a growing demand for a good support system that can ease their burden technology is ubiquitous in most social contexts in the united states and other industrialized countries and has become an important part of everyday life as an integral component of most activities the advent of technology has shown promising results in various fields such as the delivery of care and in vehicle driving technology by focusing on the needs of older adults and placing them at the center of this transformation such systems would work in favor of improving and empowering not just the elderly but also their families while reducing some of the burden on them and increasing independence yet there continues to exist a digital divide amongst the elderly population with less use of technology causing them to become disenfranchised and disadvantaged
infrapatellar bursitis is the inflammation of one or both of the infrapatellar bursa which are located just below the kneecap symptoms of bursitis commonly include swelling and knee pain bursitis often develops gradually over a period of days to even months but may develop more rapidly especially in the event of trauma or infection bursitis affecting the superficial infrapatellar bursa is an occupational hazard of persons whose work involves kneeling on hard surfaces depending on the occupation affected it is known by a variety nicknames most commonly floor layers knee but also plumbers knee clergyman s knee or housewife s knee prepatellar bursitis the deep infrapatellar bursa occasionally also become inflamed swollen and painful bursitis in the deep infrapatellar bursa usually develops from chronic overuse of the knee extensor tendon patellar tendon as can occur with repetitive flexing of the knee under pressure in work duties or exercise examples might include climbing stairs jumping or deep knee bends
ingrown hair is a condition where hair curls back or grows sideways into the skin the condition is most prevalent among people who have coarse or curly hair it may or may not be accompanied by an infection of the hair follicle folliculitis or razor bumps pseudofolliculitis barbae which vary in size while ingrown hair most commonly appears in areas where the skin is shaved or waxed beard legs pubic region it can appear anywhere anything which causes the hair to be broken off unevenly with a sharp tip can cause ingrown hairs shaving is the leading cause followed by waxing and tight clothing
onychocryptosis from greek ὄνυξ onyx nail κρυπτός kryptos hidden also known as an ingrown toenail or unguis incarnates is a common form of nail disease it is an often painful condition in which the nail grows so that it cuts into one or both sides of the paronychium or nail bed the common opinion is that the nail enters inside the paronychium but an ingrown toenail can simply be overgrown toe skin the condition starts from a microbial inflammation of the paronychium then a granuloma which results in a nail buried inside of the granuloma while ingrown nails can occur in the nails of both the hands and the feet they occur most commonly with the toenails a true ingrown toenail or onychocryptosis is caused by the actual penetration of flesh by a sliver of nail
an inguinal hernia is a protrusion of abdominal cavity contents through the inguinal canal symptoms are present in about 66 of affected people this may include pain or discomfort especially with coughing exercise or bowel movements often it gets worse throughout the day and improves when lying down a bulging area may occur that becomes larger when bearing down inguinal hernias occur more often on the right than left side the main concern is strangulation where the blood supply to part of the intestine is blocked this usually produces severe pain and tenderness of the area risk factors for the development of a hernia include smoking chronic obstructive pulmonary disease obesity pregnancy peritoneal dialysis collagen vascular disease and previous open appendectomy among others hernias are partly genetic and occur more often in certain families it is unclear if inguinal hernias are associated with heavy lifting hernias can often be diagnosed based on signs and symptoms occasionally medical imaging is used to confirm the diagnosis or rule out other possible causes groin hernias that do not cause symptoms in males do not need to be repaired repair however is generally recommended in females due to the higher rate of femoral hernias which have more complications if strangulation occurs immediate surgery is required repair may be done by open surgery or by laparoscopic surgery open surgery has the benefit of possibly being done under local anesthesia rather than general anesthesia laparoscopic surgery generally has less pain following the procedure about 27 of males and 3 of females develop a groin hernia at some time in their life groin hernias occur most often before the age of one and after the age of fifty inguinal femoral and abdominal hernias resulted in 51 000 deaths in 2013 and 55 000 in 1990
inhalants are a broad range of intoxicative drugs whose gases or volatile vapors are breathed in via the nose or mouth they are taken by room temperature volatilization or from a pressurized container e g nitrous oxide and do not include drugs that are sniffed after burning or heating for example amyl nitrite and toluene – the solvent used in contact cement and model airplane glue – are considered inhalants but tobacco cannabis and crack are not even though the latter are also inhaled as smoke while some inhalant drugs are prescribed by medical professionals and used for medical purposes as in the case of nitrous oxide a dental anxiolytic and pain relief agent this article focuses on inhalant use of household and industrial chemicals in a manner not intended by the manufacturer to produce intoxication or other psychoactive effects these products are used as recreational drugs for their intoxicating effect according to a 1995 report by the national institute on drug abuse the most serious inhalant abuse occurs among homeless children and teens who live on the streets completely without family ties inhalant users inhale vapor or aerosol propellant gases using plastic bags held over the mouth or by breathing from a solvent soaked rag or an open container the practices are known colloquially as sniffing huffing or bagging the effects of inhalants range from an alcohol like intoxication and intense euphoria to vivid hallucinations depending on the substance and the dose some inhalant users are injured due to the harmful effects of the solvents or gases or due to other chemicals used in the products that they are inhaling as with any recreational drug users can be injured due to dangerous behavior while they are intoxicated such as driving under the influence in some cases users have died from hypoxia lack of oxygen pneumonia cardiac failure or arrest or aspiration of vomit brain damage is typically seen with chronic long term use as opposed to short term exposure even though many inhalants are legal there have been legal actions taken in some jurisdictions to limit access by minors while solvent glue is normally a legal product a scottish court has ruled that supplying glue to children is illegal if the store knows the children intend to abuse the glue in the us thirty eight of 50 states have enacted laws making various inhalants unavailable to those under the age of 18 or making inhalant use illegal
in genetic algorithms inheritance is the ability of modeled objects to mate mutate similar to biological mutation and propagate their problem solving genes to the next generation in order to produce an evolved solution to a particular problem the selection of objects that will be inherited from in each successive generation is determined by a fitness function which varies depending upon the problem being addressed the traits of these objects are passed on through chromosomes by a means similar to biological reproduction these chromosomes are generally represented by a series of genes which in turn are usually represented using binary numbers this propagation of traits between generations is similar to the inheritance of traits between generations of biological organisms this process can also be viewed as a form of reinforcement learning because the evolution of the objects is driven by the passing of traits from successful objects which can be viewed as a reward for their success thereby promoting beneficial traits
inherited disorders of trafficking idt are a family of disorders that involve vesicular delivery of proteins they were characterized in 1975
inherited patterned lentiginosis in black people is a cutaneous condition inherited in an autosomal dominant fashion presenting in infancy or early childhood
iniencephaly a term derived from the greek word inion for nape of the neck is a rare type of cephalic disorder that was first described by étienne geoffroy saint hilaire in 1836 those afflicted with the disorder all share 3 common characteristics a defect to the occipital bone spina bifida of the cervical vertebrae and retroflexion backward bending of the head on the cervical spine stillbirth is the most common outcome with a few rare examples of live birth after which death almost invariably occurs within a short time
in astronomy the initial mass function imf is an empirical function that describes the distribution of initial masses for a population of stars the imf is often given as a probability distribution function pdf for the mass at which a star enters the main sequence begins hydrogen fusion the distribution function can then be used to construct the mass distribution the histogram of stellar masses of a population of stars the properties and evolution of a star are closely related to its mass so the imf is an important diagnostic tool for astronomers studying large quantities of stars for example the initial mass of a star is the primary factor determining its colour luminosity and lifetime the imf is relatively invariant from one group of stars to another though some observations suggest that the imf is different in different environments
injection fibrosis is a complication of intramuscular injection occurring especially often in infants and children injections are often delivered to the quadriceps triceps and gluteal muscles and thus the complication often manifests itself in those muscles patients are unable to fully flex the affected muscle the condition is painless but progressively worsens over time orthopedic surgery is the typical treatment
injection site reactions are allergic reactions that result in cutaneous necrosis that may occur at sites of medication injection typically presenting in one of two forms 1 those associated with intravenous infusion or 2 those related to intramuscular injection intra muscular injections may produce a syndrome called livedo dermatitis
in mathematics an injective function or injection or one to one function is a function that preserves distinctness it never maps distinct elements of its domain to the same element of its codomain in other words every element of the function s codomain is the image of at most one element of its domain the term one to one function must not be confused with one to one correspondence aka bijective function which uniquely maps all elements in both domain and codomain to each other see figures occasionally an injective function from x to y is denoted f x ↣ y using an arrow with a barbed tail u 21 a 3 ↣ rightwards arrow with tail the set of injective functions from x to y may be denoted yx using a notation derived from that used for falling factorial powers since if x and y are finite sets with respectively m and n elements the number of injections from x to y is nm see the twelvefold way a function f that is not injective is sometimes called many to one however the injective terminology is also sometimes used to mean single valued i e each argument is mapped to at most one value a monomorphism is a generalization of an injective function in category theory
for the legal sense of the term see legal injury injury is damage to the body this may be caused by accidents falls hits weapons and other causes major trauma is injury that has the potential to cause prolonged disability or death in 2013 4 8 million people died from injuries up from 4 3 million in 1990 more than 30 of these deaths were transport related injuries in 2013 367 000 children less than five died from injuries down from 766 000 in 1990 injuries are the cause of 9 of all death and are the sixth leading cause of death in the world
injury of axillary nerve axillary neuropathy is a condition that can be associated with a surgical neck of the humerus fracture it can also be associated with a dislocated shoulder or with traction injury to the nerve which may be caused by over aggressive stretching or blunt trauma that does not result in fracture or dislocation one form of this injury is referred to as axillary nerve palsy injury most commonly occurs proximal to the quadrilateral space injury in this nerve causes paralysis as always to the muscles innervated by it most importantly deltoid muscle this muscle is the main abductor of the shoulder joint from 18 to 90 degrees from 0 to 18 by supraspinatus injury can result in a reduction in shoulder abduction so a test can be applied to a patient with injury of axillary nerve by trying to abduct the injured shoulder against resistance the pain from axillary neuropathy is usually dull and aching rather than sharp and increases with increasing range of motion many people notice only mild pain but considerable weakness when they try to use the affected shoulder
ink spot lentigo also known as sunburn lentigo is a cutaneous condition characterized by skin lesions commonly occurring on the shoulders
in abstract algebra an inner automorphism is a certain type of automorphism of a group defined in terms of a fixed element of the group called the conjugating element formally if g is a group and a is an element of g then the inner automorphism defined by a is the map f from g to itself defined for all x in g by the formula f x a − 1 xa here we use the convention that group elements act on the right the operation x a − 1 xa is called conjugation see also conjugacy class and it is often of interest to distinguish the cases where conjugation by one element leaves another element unchanged from cases where conjugation generates a new element in fact saying that conjugation of x by a leaves x unchanged is equivalent to saying that a and x commute a − 1 xa x ⇔ ax xa therefore the existence and number of inner automorphisms that are not the identity mapping is a kind of measure of the failure of the commutative law in the group an automorphism of a group g is inner if and only if it extends to every group containing g
in mathematics in particular in measure theory an inner measure is a function on the set of all subsets of a given set with values in the extended real numbers satisfying some technical conditions intuitively the inner measure of a set is a lower bound of the size of that set
inner sphere or bonded electron transfer is a redox chemical reaction that proceeds via a covalent linkage — a strong electronic interaction — between the oxidant and the reductant reactants in inner sphere is electron transfer et a ligand bridges the two metal redox centers during the electron transfer event inner sphere reactions are inhibited by large ligands which prevent the formation of the crucial bridged intermediate thus is et is rare in biological systems where redox sites are often shielded by bulky proteins inner sphere et is usually used to describe reactions involving transition metal complexes and most of this article is written from this perspective however redox centers can consist of organic groups rather than metal centers the bridging ligand could be virtually any entity that can convey electrons typically such a ligand has more than one lone electron pair such that it can serve as an electron donor to both the reductant and the oxidant common bridging ligands include the halides and the pseudohalides such as hydroxide and thiocyanate more complex bridging ligands are also well known including oxalate malonate and pyrazine prior to et the bridged complex must form and such processes are often highly reversible electron transfer occurs through the bridge once it is established in some cases the stable bridged structure may exist in the ground state in other cases the bridged structure may be a transiently formed intermediate or else as a transition state during the reaction the alternative to inner sphere electron transfer is outer sphere electron transfer in any transition metal redox process the mechanism can be assumed to be outer sphere unless the conditions of the inner sphere are met inner sphere electron transfer is generally enthalpically more favorable than outer sphere electron transfer due to a larger degree of interaction between the metal centers involved however inner sphere electron transfer is usually entropically less favorable since the two sites involved must become more ordered come together via a bridge than in outer sphere electron transfer
innermost station is cause effect s third release contains nine introspective tracks including the single world is ours soon after the recording of innermost station was completed drummer richard shepherd amicably left the band to pursue personal interests released in 1997 under the liquefaction label the album was re released in 1999
the innocent prisoner s dilemma or parole deal is a detrimental effect of a legal system in which admission of guilt can result in reduced sentences or early parole when an innocent person is wrongly convicted of a crime legal systems which need the individual to admit guilt for example as a prerequisite step leading to parole punish an innocent person for his integrity and reward a person lacking in integrity there have been many cases where innocent prisoners were given the choice between freedom in exchange for claiming guilt and remaining imprisoned and telling the truth individuals have died in prison rather than admit to crimes which they did not commit it has been demonstrated in britain that prisoners who freely admit their guilt are more likely to re offend than prisoners who maintain their innocence yet parole officers perceive prisoners claiming innocence to be more likely to re offend other research however has found no clear link between denial of guilt and recidivism united states law professor daniel medwed says convicts who go before a parole board maintaining their innocence are caught in a catch 22 which he calls the innocent prisoner ’ s dilemma a false admission of guilt and remorse by an innocent person at a parole hearing may prevent a later investigation proving their innocence
in time series analysis or forecasting — as conducted in statistics signal processing and many other fields — the innovation is the difference between the observed value of a variable at time t and the optimal forecast of that value based on information available prior to time t if the forecasting method is working correctly successive innovations are uncorrelated with each other i e constitute a white noise time series thus it can be said that the innovation time series is obtained from the measurement time series by a process of whitening or removing the predictable component the use of the term innovation in the sense described here is due to hendrik bode and claude shannon 1950 in their discussion of the wiener filter problem although the notion was already implicit in the work of kolmogorov
the innovations vector or residual vector is the difference between the measurement vector and the predicted measurement vector each difference represents the deviation of the observed random variable from the predicted response the innovation vector is often used to check the validity of a model
inosculation is a natural phenomenon in which trunks branches or roots of two trees grow together it is biologically very similar to grafting it is most common for branches of two trees of the same species to grow together though inosculation may be noted across related species the branches first grow separately in proximity to each other until they touch at this point the bark on the touching surfaces is gradually abraded away as the trees move in the wind once the cambium of two trees touches they sometimes self graft and grow together as they expand in diameter inosculation customarily results when tree limbs are braided or pleached the term inosculation is also used in the context of plastic surgery as one of the three mechanisms by which skin grafts take at the host site blood vessels from the recipient site are believed to connect with those of the graft in order to restore vascularity
insanity craziness or madness is a spectrum of behaviors characterized by certain abnormal mental or behavioral patterns insanity may manifest as violations of societal norms including a person becoming a danger to themselves or others though not all such acts are considered insanity likewise not all acts showing indifference toward societal norms are acts of insanity in modern usage insanity is most commonly encountered as an informal unscientific term denoting mental instability or in the narrow legal context of the insanity defense in the medical profession the term is now avoided in favor of diagnoses of specific psychiatric diseases the presence of delusions or hallucinations is broadly referred to as psychosis when discussing psychiatric illness in general terms psychopathology is considered a preferred descriptor in english the word sane derives from the latin adjective sanus meaning healthy juvenal s phrase mens sana in corpore sano is often translated to mean a healthy mind in a healthy body from this perspective insanity can be considered as poor health of the mind not necessarily of the brain as an organ although that can affect mental health but rather refers to defective function of mental processes such as reasoning another latin phrase related to our current concept of sanity is compos mentis lit sound of mind and a euphemistic term for insanity is non compos mentis in law mens rea means having had criminal intent or a guilty mind when the act actus reus was committed a more informal use of the term insanity is to denote something considered highly unique passionate or extreme including in a positive sense the term may also be used as an attempt to discredit or criticise particular ideas beliefs principles desires personal feelings attitudes or their proponents such as in politics and religion
insect bites and stings occur when an insect is agitated and seeks to defend itself through its natural defense mechanisms or when an insect seeks to feed off the bitten person some insects inject formic acid which can cause an immediate skin reaction often resulting in redness and swelling in the injured area stings from fire ants bees wasps and hornets are usually painful and may stimulate a dangerous allergic reaction called anaphylaxis for at risk patients and some wasps can also have a powerful bite along with a sting bites from mosquitoes and fleas are more likely to cause itching than pain the skin reaction to insect bites and stings usually lasts for up to a few days however in some cases the local reaction can last for up to two years these bites are sometimes misdiagnosed as other types of benign or cancerous lesions
an insertion reaction is a chemical reaction where one chemical entity a molecule or molecular fragment interposes itself into an existing bond of typically a second chemical entity e g a b – c → b – a – c the term only refers to the result of the reaction and does not suggest a mechanism insertion reactions are observed in organic inorganic and organometallic chemistry in cases where a metal ligand bond in a coordination complex is involved these reactions are typically organometallic in nature and involve a bond between a transition metal and a carbon or hydrogen it is usually reserved for the case where the coordination number and oxidation state of the metal remain unchanged when these reactions are reversible the removal of the small molecule from the metal ligand bond is called extrusion or elimination there are two common insertion geometries — 1 1 and 1 2 pictured above additionally the inserting molecule can act either as a nucleophile or as an electrophile to the metal complex these behaviors will be discussed in more detail for co nucleophilic behavior and so 2 electrophilic behavior
in economics the inside lag or inside recognition and decision lag is the amount of time it takes for a government or a central bank to respond to a shock in the economy it is the delay in implementation of a fiscal policy or monetary policy its converse is the outside lag the amount of time before an action by a government or a central bank affects an economy the inside lag comprises the recognition lag the time taken to recognize the shock and the decision lag the time taken to decide on and pursue a response the inside lag is generally a more severe problem for fiscal policy government spending and taxation policy than for monetary policy monetary policy is conducted by a central bank that is devoted substantially to monitoring and responding to economic shocks whereas fiscal policy is conducted by a law making body that has many other issues to confront as well as a highly deliberative process with which to confront them nevertheless a central bank may often experience a substantial recognition lag prior to its becoming clear just what the latest economic figures imply for policy needs indeed even after a central bank implements a policy response its critics may still argue that it recognized the situation incorrectly
insomnia also known as sleeplessness is a sleep disorder where people have trouble sleeping they may have difficulty falling asleep or staying asleep as long as desired insomnia is typically followed by daytime sleepiness low energy irritability and a depressed mood it may result in an increased risk of motor vehicle collisions as well as problems focusing and learning insomnia can be short term lasting for days or weeks or long term lasting more than a month insomnia can occur independently or as a result of another problem conditions that can result in insomnia include psychological stress chronic pain heart failure hyperthyroidism heartburn restless leg syndrome menopause certain medications and drugs such as caffeine nicotine and alcohol other risk factors include working night shifts and sleep apnea diagnosis is based on sleep habits and an examination to look for underlying causes a sleep study may be done to look for underlying sleep disorders screening may be done with two questions do you experience difficulty sleeping and do you have difficulty falling or staying asleep sleep hygiene and lifestyle changes are typically the first treatment for insomnia sleep hygiene includes a consistent bedtime exposure to sunlight a quiet and dark room and regular exercise cognitive behavioral therapy may be added to this while sleeping pills may help they are associated with injuries dementia and addiction medications are not recommended for more than four or five weeks the effectiveness and safety of alternative medicine is unclear between 10 and 30 of adults have insomnia at any given point in time and up to half of people have insomnia in a given year about 6 of people have insomnia that is not due to another problem and lasts for more than a month people over the age of 65 are affected more often than younger people females are more often affected than males descriptions of insomnia occur at least as far back as ancient greece
in computers instant on is the ability to boot nearly instantly thus allowing to go online or to use a specific application without waiting for a pc s traditional operating system to launch instant on technology is today mostly used on laptops netbooks and nettops because the user can boot up one program instead of waiting for the pc s entire operating system to boot for instance a user may want to just launch a movie playing program or launch an internet browser without needing the whole operating system there are and were true instant on machines such as the atari st as described in the booting article these machines had complete operating systems resident in rom similar to the way in which the bios function is conventionally provided on current computer architectures the instant on concept as used here results from loading an os such as a legacy system dos with a small hard drive footprint latency inherent to mechanical drive performance can also be eliminated by using live usb or live sd flash memory to load systems at electronic speeds which are orders of magnitude faster
insufficient justification insufficient punishment is a phenomenon under the realm of social psychology it synthesizes theories of cognitive dissonance and internal vs external justification essentially insufficient justification is when an individual utilizes internal motivation to justify a behavior it is most commonly seen in insufficient punishment which is the dissonance experienced when individuals lack sufficient external justification for having resisted a desired activity or object usually resulting in individuals ’ devaluing the forbidden activity or object that is when an individual can ’ t come up with an external reason as to why they resisted doing something they wanted to he or she decides to derogate the activity mild punishment will cause a more lasting behavioral change than severe punishment because internal justification is stronger than external justification
insulin resistance ir is a pathological condition in which cells fail to respond normally to the hormone insulin the body produces insulin when glucose starts to be released into the bloodstream from the digestion of carbohydrates in the diet normally this insulin response triggers glucose being taken into body cells to be used for energy and inhibits the body from using fat for energy the level of glucose in the blood decreases as a result staying within the normal range even when a large amount of carbohydrates is consumed this reflects the healthy amount of insulin sensitivity in contrast when the body produces insulin under conditions of insulin resistance the cells are resistant to the insulin and are unable to use it as effectively leading to high blood sugar beta cells in the pancreas subsequently increase their production of insulin further contributing to a high blood insulin level this often remains undetected and can contribute to a diagnosis of type 2 diabetes or latent autoimmune diabetes of adults although this type of chronic insulin resistance is harmful during acute illness it is actually a well evolved protective mechanism recent investigations have revealed that insulin resistance helps to conserve the brain s glucose supply by preventing muscles from taking up excessive glucose insulin resistance should even be strengthened under harsh metabolic conditions such as pregnancy during which the expanding fetal brain demands more glucose people who develop type 2 diabetes usually pass through earlier stages of insulin resistance and prediabetes although those often go undiagnosed insulin resistance syndrome is a syndrome a set of signs and symptoms resulting from insulin resistance it is also called metabolic syndrome
an insulinoma is a tumor of the pancreas that is derived from beta cells and secretes insulin it is a rare form of a neuroendocrine tumor most insulinomas are benign in that they grow exclusively at their origin within the pancreas but a minority metastasize insulinomas are one of the functional pannet group functional because it increases production of insulin pannet as an abbreviation of pancreatic neuroendocrine tumor in the medical subject headings classification insulinoma is the only sub type of islet cell adenoma beta cells secrete insulin in response to increases in blood glucose the resulting increase in insulin acts to lower blood glucose back to normal levels at which point further secretion of insulin is stopped in contrast the secretion of insulin by insulinomas is not properly regulated by glucose and the tumors will continue to secrete insulin causing glucose levels to fall further than normal as a result patients present symptoms of low blood glucose hypoglycemia which are improved by eating the diagnosis of an insulinoma is usually made biochemically with low blood glucose elevated insulin proinsulin and c peptide levels and confirmed by localizing the tumor with medical imaging or angiography the definitive treatment is surgery
insulitis is an inflammation of the islets of langerhans a collection of endocrine tissue located in the pancreas the islets containing the pancreatic β cells and in some cases the exocrine tissues become infiltrated by t and b lymphocytes macrophages and dendritic cells this innate immune cell and lymphocyte infiltration can result in destruction of the insulin producing beta cells of the islets and clinical diabetes insulitis is often studied in the multiple low dose streptozotocin mlds mouse model or the nod mouse model of type 1 diabetes the chemokine family of proteins may play a key role in promoting leukocytic infiltration into the pancreas prior to pancreatic beta cell destruction
in medical terms an insult is the cause of some kind of physical or mental injury for example a burn on the skin the injury may be the result of a thermal chemical radioactive or electrical event the insult likewise sepsis and trauma are examples of foreign insults and encephalitis multiple sclerosis and brain tumors are examples of insults to the brain insults may also be categorized as either genetic or environmental
in mathematics an integer valued function is a function whose values are integers in other words it is a function that assigns an integer to each member of its domain floor and ceiling functions are examples of an integer valued function of a real variable but on real numbers and generally on non disconnected topological spaces integer valued functions are not especially useful any such function on a connected space either has discontinuities or is constant on the other hand on discrete and other totally disconnected spaces integer valued functions have roughly the same importance as real valued functions have on non discrete spaces any function with natural or non negative integer values is a partial case of integer valued function
in computer science integer sorting is the algorithmic problem of sorting a collection of data values by numeric keys each of which is an integer algorithms designed for integer sorting may also often be applied to sorting problems in which the keys are floating point numbers rational numbers or text strings the ability to perform integer arithmetic on the keys allows integer sorting algorithms to be faster than comparison sorting algorithms in many cases depending on the details of which operations are allowed in the model of computing and how large the integers to be sorted are integer sorting algorithms including pigeonhole sort counting sort and radix sort are widely used and practical other integer sorting algorithms with smaller worst case time bounds are not believed to be practical for computer architectures with 64 or fewer bits per word many such algorithms are known with performance depending on a combination of the number of items to be sorted number of bits per key and number of bits per word of the computer performing the sorting algorithm
in mathematics an integrating factor is a function that is chosen to facilitate the solving of a given equation involving differentials it is commonly used to solve ordinary differential equations but is also used within multivariable calculus when multiplying through by an integrating factor allows an inexact differential to be made into an exact differential which can then be integrated to give a scalar field this is especially useful in thermodynamics where temperature becomes the integrating factor that makes entropy an exact differential
the integration competency center icc sometimes referred to as an integration center of excellence coe is a shared service function within an organization particularly large corporate enterprises as well as public sector institutions for performing methodical data integration system integration or enterprise application integration data integration allows companies to access their enterprise data and functions fragmented across disparate systems in order to create a combined accurate and consistent view of their core information as well as process assets and leverage them across the enterprise to drive business decisions and operations system integration is the bringing together of component subsystems into one system and ensuring that they function together effectively enterprise application integration enables efficient information exchanges and business process automation across separate computer applications in a cohesive fashion
intellectual disability id also known as general learning disability and mental retardation mr is a generalized neurodevelopmental disorder characterized by significantly impaired intellectual and adaptive functioning it is defined by an iq score under 70 in addition to deficits in two or more adaptive behaviors that affect everyday general living once focused almost entirely on cognition the definition now includes both a component relating to mental functioning and one relating to individuals functional skills in their environments as a result of this focus on the person s abilities in practice a person with an unusually low iq may not be considered intellectually disabled intellectual disability is subdivided into syndromic intellectual disability in which intellectual deficits associated with other medical and behavioral signs and symptoms are present and non syndromic intellectual disability in which intellectual deficits appear without other abnormalities down syndrome and fragile x syndrome are examples of syndromic intellectual disabilities intellectual disability affects about 2 – 3 of the general population seventy five to ninety percent of the affected people have mild intellectual disability non syndromic or idiopathic cases account for 30 – 50 of cases about a quarter of cases are caused by a genetic disorder and about 5 of cases are inherited from a person s parents cases of unknown cause affect about 95 million people as of 2013 the terms used for this condition are subject to a process called the euphemism treadmill this means that whatever term is chosen for this condition it eventually becomes perceived as an insult the terms mental retardation and mentally retarded were invented in the middle of the 20 th century to replace the previous set of terms which were deemed to have become offensive by the end of the 20 th century these terms themselves have come to be widely seen as disparaging politically incorrect and in need of replacement the term intellectual disability is now preferred by most advocates and researchers in most english speaking countries as of 2015 the term mental retardation is still used by the world health organization in the icd 10 codes which have a section titled mental retardation codes f 70 – f 79 in the next revision the icd 11 is expected to replace the term mental retardation with either intellectual disability or intellectual developmental disorder which the dsm 5 already uses because of its specificity and lack of confusion with other conditions the term mental retardation is still sometimes used in professional medical settings around the world such as formal scientific research and health insurance paperwork
intellectual giftedness is an intellectual ability significantly higher than average it is a characteristic of children variously defined that motivates differences in school programming it is thought to persist as a trait into adult life with various consequences studied in longitudinal studies of giftedness over the last century there is no generally agreed definition of giftedness for either children or adults but most school placement decisions and most longitudinal studies over the course of individual lives have been based on iq in the top 2 percent of the population that is above iq 130 the various definitions of intellectual giftedness include either general high ability or specific abilities for example by some definitions an intellectually gifted person may have a striking talent for mathematics without equally strong language skills in particular the relationship between artistic ability or musical ability and the high academic ability usually associated with high iq scores is still being explored with some authors referring to all of those forms of high ability as giftedness while other authors distinguish giftedness from talent there is still much controversy and much research on the topic of how adult performance unfolds from trait differences in childhood and what educational and other supports best help the development of adult giftedness
in data mining intention mining or intent mining is the problem of determining a user s intention from logs of their behavior in interaction with a computer system such as a search engine this notion is introduced for the first time in the paper of dr ghazaleh khodabandelou some authors model the intentions as an intentional process model in order to have a better understanding of the human way of thinking
intention tremor also known as cerebellar tremor is a dyskinetic disorder characterized by a broad coarse and low frequency below 5 hz tremor the amplitude of an intention tremor increases as an extremity approaches the endpoint of deliberate and visually guided movement hence the name intention tremor an intention tremor is usually perpendicular to the direction of movement when experiencing an intention tremor one often overshoots or undershoots their target a condition known as dysmetria intention tremor is the result of dysfunction of the cerebellum particularly on the same side as the tremor in the lateral zone which controls visually guided movements depending on the location of cerebellar damage these tremors can be either unilateral or bilateral a variety of causes have been discovered to date including damage or degradation of the cerebellum due to neurodegenerative diseases trauma tumor stroke or toxicity there is currently no established pharmacological treatment however some success has been seen using treatments designed for essential tremors
the interaural time difference or itd when concerning humans or animals is the difference in arrival time of a sound between two ears it is important in the localization of sounds as it provides a cue to the direction or angle of the sound source from the head if a signal arrives at the head from one side the signal has further to travel to reach the far ear than the near ear this pathlength difference results in a time difference between the sound s arrivals at the ears which is detected and aids the process of identifying the direction of sound source when a signal is produced in the horizontal plane its angle in relation to the head is referred to as its azimuth with 0 degrees 0 ° azimuth being directly in front of the listener 90 ° to the right and 180 ° being directly behind
an intercalated seizure is an epileptic seizure that occurs during the aura stage of a migraine it has been found in some cases that this type of seizure is instigated by the migraine preceding it coining the term migraine triggered seizure in order to be considered such the victim must have already had certified migraines with aura and a seizure must occur within one hour after the beginning of the aura the neurological condition that combines migraines with epileptic seizures is known as migralepsy
intercepting filter is a javaee pattern which creates pluggable filters to process common services in a standard manner without requiring changes to core request processing code the filters intercept incoming requests and outgoing responses allowing preprocessing and post processing and these filters can be added or removed unobstrusively without changing existing code this pattern applies reusable processing transparently before and after the actual request execution by the front and page controllers
in the field of software development an interceptor pattern is a software design pattern that is used when software systems or frameworks want to offer a way to change or augment their usual processing cycle for example a simplified typical processing sequence for a web server is to receive a uri from the browser map it to a file on disk open the file and send its contents to the browser any of these steps could be replaced or changed e g by replacing the way uris are mapped to filenames or by inserting a new step which processes the files contents key aspects of the pattern are that the change is transparent and used automatically in essence the rest of the system does not have to know something has been added or changed and can keep working as before to facilitate this a predefined interface for extension has to be implemented some kind of dispatching mechanism is required where interceptors are registered this may be dynamic at runtime or static e g through configuration files and context objects are provided which allow access to the framework s internal state
the chalcogens react with each other to form interchalcogen compounds although no chalcogen is extremely electropositive nor quite as electronegative as the halogen fluorine the most electronegative element there is a large difference in electronegativity between the top oxygen 3 44 and bottom polonium 2 0 of the group combined with the fact that there is a significant trend towards increasing metallic behaviour while descending the group oxygen is a gaseous nonmetal while polonium is a silvery post transition metal this causes the interchalcogens to display many different kinds of bonding covalent ionic metallic and semimetallic
in computer science interchangeability is an ability that an object can be replaced by another object without affecting code using the object that chance usually requires two objects share an interface that is either same strictly or compatible in particular case see encapsulation article for detail
the intercondylar area is the separation between the medial and lateral condyle on the upper extremity of the tibia the anterior and posterior cruciate ligaments and the menisci attach to the intercondylar area the intercondyloid eminence is composed of the medial and lateral intercondylar tubercles and divides the intercondylar area into an anterior and a posterior area
intercultural competence is the ability to communicate effectively and appropriately with people of other cultures appropriately valued rules norms and expectations of the relationship are not violated significantly effectively valued goals or rewards relative to costs and alternatives are accomplished in interactions with people from foreign cultures a person who is interculturally competent understands the culture specific concepts of perception thinking feeling and acting intercultural competence is also called cross cultural competence 3 c
an intercurrent or concurrent concomitant or in most cases pre existing disease in pregnancy is a disease that is not directly caused by the pregnancy in contrast to a complication of pregnancy but which may become worse or be a potential risk to the pregnancy such as causing pregnancy complications a major component of this risk can result from necessary use of drugs in pregnancy to manage the disease in such circumstances women who wish to continue with a pregnancy require extra medical care often from an interdisciplinary team such a team might include besides an obstetrician a specialist in the disorder and other practitioners for example maternal fetal specialists or obstetric physicians dieticians etc
in statistics the interdecile range is the difference between the first and the ninth deciles 10 and 90 the interdecile range is a measure of statistical dispersion of the values in a set of data similar to the range and the interquartile range and can be computed from the non parametric seven number summary despite its simplicity for estimating the standard deviation of a normal distribution the scaled interdecile range gives a reasonably efficient estimator more precisely a more efficient estimator is given by instead taking the 7 trimmed range the difference between the 7 th and 93 rd percentiles and dividing by 3 corresponding to 86 of the data of a normal distribution falling within 1 5 standard deviations of the mean yields an estimate of about 65 efficiency analogous measures of location are given by the median midhinge and trimean or statistics based on nearby points
the study of interdependent networks is a subfield of network science dealing with phenomena caused by the interactions between complex networks though there may be a wide variety of interactions between networks dependency focuses on the scenario in which the nodes in one network require support from nodes in another network
interdigital webbing is the presence of membranes of skin between the digits normally in mammals webbing is present in the embryo but resorbed later in development but in various mammal species it occasionally persists in adulthood in humans it can be found in those suffering from leopard syndrome and from aarskog scott syndrome webbing between the digits of the hindfoot is also present in several mammals that spend part of their time in the water webbing accommodates movement in the water interdigital webbing is not to be confused with syndactyly which is a fusing of digits and occurs rarely in humans syndactyly specifically affecting feet occurs in birds such as ducks amphibians such as frogs and mammals such as the kangaroo
interdigitating dendritic cell sarcoma is a form of malignant histiocytosis affecting dendritic cells it can present in the spleen it can also present in the duodenum
interest rate parity is a no arbitrage condition representing an equilibrium state under which investors will be indifferent to interest rates available on bank deposits in two countries the fact that this condition does not always hold allows for potential opportunities to earn riskless profits from covered interest arbitrage two assumptions central to interest rate parity are capital mobility and perfect substitutability of domestic and foreign assets given foreign exchange market equilibrium the interest rate parity condition implies that the expected return on domestic assets will equal the exchange rate adjusted expected return on foreign currency assets investors then cannot earn arbitrage profits by borrowing in a country with a lower interest rate exchanging for foreign currency and investing in a foreign country with a higher interest rate due to gains or losses from exchanging back to their domestic currency at maturity interest rate parity takes on two distinctive forms uncovered interest rate parity refers to the parity condition in which exposure to foreign exchange risk unanticipated changes in exchange rates is uninhibited whereas covered interest rate parity refers to the condition in which a forward contract has been used to cover eliminate exposure to exchange rate risk each form of the parity condition demonstrates a unique relationship with implications for the forecasting of future exchange rates the forward exchange rate and the future spot exchange rate economists have found empirical evidence that covered interest rate parity generally holds though not with precision due to the effects of various risks costs taxation and ultimate differences in liquidity when both covered and uncovered interest rate parity hold they expose a relationship suggesting that the forward rate is an unbiased predictor of the future spot rate this relationship can be employed to test whether uncovered interest rate parity holds for which economists have found mixed results when uncovered interest rate parity and purchasing power parity hold together they illuminate a relationship named real interest rate parity which suggests that expected real interest rates represent expected adjustments in the real exchange rate this relationship generally holds strongly over longer terms and among emerging market countries
interface based programming also known as interface based architecture is an architectural pattern for implementing modular programming at the component level in an object oriented programming language which does not have a module system an example of such a language is java which as of 2015 does not have a module system at the level of components java has a package system but java software components typically consist of multiple java packages – and in any case interface programming can provide advantages over merely using java packages even if a component only consists of a single java package interface based programming defines the application as a collection of components in which application programming interface api calls between components may only be made through abstract interfaces not concrete classes instances of classes will generally be obtained through other interfaces using techniques such as the factory pattern this is claimed to increase the modularity of the application and hence its maintainability however some caution is warranted – merely splitting an application into arbitrary components communicating via interfaces does not in itself guarantee low coupling or high cohesion two other attributes that are commonly regarded as key for maintainability an interface based architecture can be used when third parties – or indeed separate teams within the same organisation – develop additional components or plugins for an established system the codebase of the eclipse ide is an example of interface based programming eclipse plugin vendors just have to develop components that satisfy the interface specified by the parent application vendor the eclipse foundation indeed in eclipse even the original components such as the java development tools are themselves plugins this is somewhat like a mobile phone manufacturer specifying a mobile charger interface pin arrangement expected direct current voltage etc and both the manufacturer and third parties making their own mobile phone chargers that comply with this standard interface specification
for interference in radio communications see interference communication interference pattern redirects here for moiré patterns see moiré pattern in physics interference is a phenomenon in which two waves superpose to form a resultant wave of greater lower or the same amplitude interference usually refers to the interaction of waves that are correlated or coherent with each other either because they come from the same source or because they have the same or nearly the same frequency interference effects can be observed with all types of waves for example light radio acoustic surface water waves or matter waves
the interference of the footings is a phenomenon that is observed when two footings are closely spaced the buildings when are to be constructed nearby to each other the architectural requirements or the less availability of space for the construction forces the engineers to place the foundation footings close to each other and when foundations are placed close to each other with similar soil conditions the ultimate bearing capacity of each foundation may change due to the interference effect of the failure surface in the soil
an intergranular fracture is a fracture that follows the grains of the material where cracks that take place along the grain boundary in a wall of bricks it would correspond to a fracture that takes place in the mortar that keep together bricks in metals with multiple lattice organizations when one lattice ends and another begins the fracture changes direction to follow the new grain this results in a fairly jagged looking fracture with straight edges of the grain and shiny surface may be seen in ceramics interganular fractures propagate through grain boundaries producing smooth bumpy surfaces where grains can be easily identified there are several processes that can lead to intergranular fracture microvoid nucleation and coalescence at inclusions or second phase particles located along grain boundaries grain boundary crack and cavity formation associated with elevated temperature stress rupture condition decohesion between contiguous grain due to presence of impurity at grain boundaries and in the presence of hydrogen and liquid metals stress corrosion cracking associated with chemical dissolution along grain boundaries cyclic loading when the material insufficient number of independent slip systems to accommodate plastic deformation between contiguous grain leading to grain boundaries think of several wooden jigsaw puzzle pieces with the grains showing but with each piece having grains running in a different direction an intergranular fracture follows the edges of the puzzle pieces ignoring the grains in the wood this is opposed to a transgranular fracture
intergroup anxiety is the social phenomenon identified by walter and cookie stephan in 1985 that describes the ambiguous feelings of discomfort or anxiety when interacting with members of other groups such emotions also constitute intergroup anxiety when one is merely anticipating interaction with members of an outgroup expectations that interactions with foreign members of outgroups will result in an aversive experience is believed to be the cause of intergroup anxiety with an affected individual being anxious or unsure about a number of issues methods of reducing intergroup anxiety stress facilitating positive intergroup contact
interictal dysphoric disorder idd is a mood disorder sometimes found in patients with epilepsy at a prevalence rate of approximately 17 the most common symptom of idd is intermittent dysphoric mood in between seizures interictal dysphoric disorder can often be treated with a combination of antidepressant and anticonvulsant medication
interlanguage fossilization is a phenomenon of second language acquisition sla in which second language learners develop and retain a linguistic system or interlanguage that is self contained and different from both the learner ’ s first language and the target language this linguistic system has been variously called interlanguage approximative system idiosyncratic dialects or transitional dialects
intermediate trophoblast is a distinct subtype of trophoblastic tissue that arises from the cytotrophoblast it is sub categorized by location villous intermediate trophoblast at anchoring villi of trophoblastic column implantation site intermediate trophoblast at implantation site or basal plate differentiated from villous intermediate trophoblast chorionic type intermediate trophoblast at chorionic laeve of fetal membrane differentiated from villous intermediate trophoblast
intermetamorphosis is a delusional misidentification syndrome related to agnosia the main symptoms consist of patients believing that they can see others change into someone else in both external appearance and internal personality the disorder is usually comorbid with neurological disorders or mental disorders an example from medical literature is a man who was diagnosed with alzheimer s disease after some time he mistook his wife for his deceased mother and later for his sister as an explanation he stated that he had never been married or that his wife had left him later he mistook his son for his brother and his daughter for another sister visual agnosia or prosopagnosia were not diagnosed as the misidentification also took place during phone calls on several occasions he mistook the hospital for the church he used to go to the disorder was first described in 1932 by p courbon and j tusques illusions d intermétamorphose et de la charme in the journal annales medico psychologiques issue 14 page 401 406
intermittent claudication latin claudicatio intermittens is a symptom that describes muscle pain ache cramp numbness or sense of fatigue classically in the calf muscle which occurs during exercise such as walking and is relieved by a short period of rest it is classically associated with early stage peripheral artery disease and can progress to critical limb ischemia unless treated or risk factors are modified claudication derives from the latin verb claudicare to limp
intermittent explosive disorder sometimes abbreviated as ied is a behavioral disorder characterized by explosive outbursts of anger and violence often to the point of rage that are disproportionate to the situation at hand e g impulsive screaming triggered by relatively inconsequential events impulsive aggression is unpremeditated and is defined by a disproportionate reaction to any provocation real or perceived some individuals have reported affective changes prior to an outburst e g tension mood changes energy changes etc the disorder is currently categorized in the diagnostic and statistical manual of mental disorders dsm 5 under the disruptive impulse control and conduct disorders category the disorder itself is not easily characterized and often exhibits comorbidity with other mood disorders particularly bipolar disorder individuals diagnosed with ied report their outbursts as being brief lasting less than an hour with a variety of bodily symptoms sweating stuttering chest tightness twitching palpitations reported by a third of one sample aggressive acts are frequently reported accompanied by a sensation of relief and in some cases pleasure but often followed by later remorse
an intermittent fault often called simply an intermittent is a malfunction of a device or system that occurs at intervals usually irregular in a device or system that functions normally at other times intermittent faults are common to all branches of technology including computer software an intermittent fault is caused by several contributing factors some of which may be effectively random which occur simultaneously the more complex the system or mechanism involved the greater the likelihood of an intermittent fault a simple example of an effectively random cause in a physical system is a borderline electrical connection in the wiring or a component of a circuit where cause 1 the cause that must be identified and rectified two conductors may touch subject to cause 2 which need not be identified a minor change in temperature vibration orientation voltage etc sometimes this is described as an intermittent connection rather than fault in computer software a program may cause 1 fail to initialise a variable which is required to be initially zero if the program is run in circumstances such that memory is almost always clear before it starts it will malfunction on the rare occasions that cause 2 the memory where the variable is stored happens to be non zero beforehand intermittent faults are notoriously difficult to identify and repair troubleshoot because each individual factor does not create the problem alone so the factors can only be identified while the malfunction is actually occurring the person capable of identifying and solving the problem is seldom the usual operator because the timing of the malfunction is unpredictable and both device or system downtime and engineers time incur cost the fault is often simply tolerated if not too frequent unless it causes unacceptable problems or dangers for example some intermittent faults in critical equipment such as medical life support equipment could result in killing a patient or in aeronautics causes a flight to be aborted or in some cases crash if an intermittent fault occurs for long enough during troubleshooting it can be identified and resolved in the usual way some techniques to resolve intermittent faults are automatic logging of relevant parameters over a long enough time for the fault to manifest can help parameter values at the time of the fault may identify the cause so that appropriate remedial action can be taken changing operating circumstances while the fault is present to see if the fault temporarily clears or changes for example tapping components cooling them with freezer spray heating them striking the cabinet may temporarily clear the fault a database of similar faults which have been resolved in identical or similar equipment precautionary changes without attempting to pinpoint the fault for example electrolytic capacitors subject to high ripple currents can be changed as a routine measure without bothering to troubleshoot the fault at all connectors can be disconnected and reseated this is sometimes a measure of desperation things are changed until the fault stops happening and it is hoped that it is actually resolved rather than dormant in electrical systems and cable systems time domain reflectometry techniques can be used pulses are sent down electric wiring and the pulses reflected back are examined for anomalies for example intermittent leakage during the stresses of aircraft operation this can only be done for one test channel at time and is generally limited to intermittent faults 100 milliseconds in complex multiple channel systems where the fault s might be in an interconnection the ideal method of finding an intermittent fault is to be able to monitor detect and isolate all channels or electrical paths continuously and simultaneously this methodology allows the system under test to benefit from continuous and complete test coverage while any environmental stressing of the system is performed this type cannot be performed by scanning testing technology but needs to have some form of electronic neural network which can perform these test without the need for any scanning and or digital averaging this testing regime is covered by the dod s mil prf 32516 published in march 2015 and it calls for testing technology to operate in the class 1 category in order to combat intermittent faults effectively
intermittent hair – follicle dystrophy is a disorder of the hair follicle leading to increased fragility of the shaft with no identifiable biochemical disturbance also with an unknown prevalence
intermittent hydrarthrosis ih also known as periodic synoviosis periodic benign synovitis or periodic hydrarthritis is a chronic condition of unknown cause characterized by recurring temporary episodes of fluid accumulation in the knee while the knee is mainly involved occasionally other joints such as the elbow or ankle can additionally be affected fluid accumulation in the joint can be extensive causing discomfort and impairing movement although affected joints are not usually very painful while the condition is chronic it does not appear to progress to more destructive damage of the joint it seems to affect slightly more women than men episodes of swelling last several days or longer can occur with regular or semi regular frequency typically one or two episodes per month between periods of effusion knee swelling reduces dramatically providing largely symptomless intervals unlike some other rheumatological conditions such as rheumatoid arthritis laboratory findings are usually within normal ranges or limits clear treatment options have yet to be established nsaids and cox 2 inhibitors are generally not effective where this condition has been correctly diagnosed various anti rheumatic drugs as well as colchicine may be trialled to find the most effective option more aggressive intra articular treatment such chemical or radio active synovectomy can also be helpful although benefits beyond 1 year have not been reported in literature
intermittent rhythmic delta activity irda is a type of brain wave abnormality found in electroencephalograms eeg it is found in the frontal firda or occipital oirda areas of the brain and can be caused by a number of different reasons some benign unknown reasons but also are commonly associated with lesions tumors and encephalopathies
intermodal mapping is the ability inborn according to research to recognize stimuli using a sense different from the one it was originally presented to this implies that stimuli are represented universally in the brain and available to all senses and need not be learned by pairing classical conditioning
intermolecular metal catalyzed carbenoid cyclopropanations are organic reactions that result in the formation of a cyclopropane ring from a metal carbenoid species and an alkene in the simmons – smith reaction the metal involved is zinc
internal bleeding also called internal hemorrhage is a loss of blood that occurs from the vascular system into a body cavity or space it is a serious medical emergency and the extent of severity depends on bleeding rate and location of the bleeding e g heart brain stomach lungs it can cause death and cardiac arrest if proper medical treatment is not received quickly
internal communications ic is the function responsible for effective communications among participants within an organization the scope of the function varies by organization and practitioner from producing and delivering messages and campaigns on behalf of management to facilitating two way dialogue and developing the communication skills of the organization s participants modern understanding of internal communications is a field of its own and draws on the theory and practice of related professions not least journalism knowledge management public relations e g media relations marketing and human resources as well as wider organizational studies communication theory social psychology sociology and political science
internal hernias occur when there is protrusion of an internal organ into a retroperitoneal fossa or a foramen congenital or acquired in the abdominal cavity if a loop of bowel passes through the mesenteric defect that loop is at risk for incarceration strangulation or for becoming the lead point of a small bowel obstruction internal hernias can also trap adipose tissue fat and nerves unlike more common forms of hernias the trapped tissue protrudes inward rather than outward mesenteric defects commonly occur in trauma such as gunshot wounds to the abdomen in trauma victims the defect is usually closed sometimes with resection of the associated bowel which may have lost its blood supply also mesenteric defects are intentionally created in the roux en y gastric bypass procedure being classically known as a petersen s hernia the mesenteric defect in such cases called petersen s defect is located between the transverse colon and the mesentery of the alimentary limb the segment of the jejunum from the jejunojejunostomy until the connection with the proximal segment of the stomach at the level of the jejunojejunostomy internal hernias are difficult to identify in women and misdiagnosis with endometriosis or idiopathic chronic pelvic pain is very common one cause of misdiagnosis that when the woman lies down flat on an examination table all of the medical signs of the hernia disappear the hernia can typically only be detected when symptoms are present so diagnosis requires positioning the woman s body in a way that provokes symptoms both internal hernias and umbilical hernias are more common in women than men
the international classification of sleep disorders icsd is a primary diagnostic epidemiological and coding resource for clinicians and researchers in the field of sleep and sleep medicine the international classification of sleep disorders icsd was produced by the american academy of sleep medicine aasm in association with the european sleep research society the japanese society of sleep research and the latin american sleep society the classification was developed as a revision and update of the diagnostic classification of sleep and arousal disorders dcsad that was produced by both the association of sleep disorders centers asdc and the association for the psychophysiological study of sleep and was published in the journal sleep in 1979 a second edition called icsd 2 was published in 2005 the third edition icsd 3 was released in 2014
the iceid or international conference on emerging infectious diseases is a conference for public health professionals on the subject of emerging infectious diseases from cdc page for iceid the international conference on emerging infectious diseases was first convened in 1998 iceid 2006 marks its fifth occurrence the conference brings together public health professional to encourage the exchange of scientific and public health information on global emerging infectious disease issues the program will include plenary and panel sessions with invited speakers as well as oral and poster presentations on emerging infections major topics include current work on surveillance epidemiology research communication and training bioterrorism and preventions and control of emerging infectious diseases both in the united states and abroad
the international policy forum ipf is a fully student run think tank based at carleton university in ottawa canada emerging from the realization that there was an absence of student perspective in pressing policy issues participants in the ipf strive to add their voice to public debate each year approximately sixteen students are chosen to develop policy recommendations for a global issue pertinent to canada through involvement with the ipf members gain practical political experience and contribute to the understanding of public affairs from a new and often innovative perspective since its inception the ipf has addressed a diverse range of topics these have included subjects such as canada us relations humanitarian intervention and arctic transformation the ipf also operates the carleton review of international affairs cria an annual publication highlighting the work of undergraduate students relating to any topic of global interest currently the directors of the ipf are sayan basu ray and patrick salonius the ipf is funded by the un society a student organization at carleton university
the following are international reactions to the south sudanese civil war
below are the foreign reactions to the euromaidan euromaidan was a wave of demonstrations and civil unrest in ukraine that began on the night of 21 november 2013 after the ukrainian government suspended preparations for signing an association agreement and deep and comprehensive free trade agreement with the european union
internet based self services iss are a subtype of services driven by self service technologies which provide technological interfaces allowing customers to use services independently of the involvement of direct service employee self ticket purchasingand self check in for a flight using the internet are examplesof internet based self services
internet censorship circumvention describes various processes used by internet users to bypass the technical aspects of internet filtering and gain access to otherwise censored material circumvention is an inherent problem for those wishing to censor the internet because filtering and blocking do not remove content from the internet and as long as there is at least one publicly accessible uncensored system it will often be possible to gain access to otherwise censored material however circumvention may not be very useful to non tech savvy users and so blocking and filtering remain effective means of censoring the internet for many users different techniques and resources are used to bypass internet censorship including cached web pages web mirrors and archive sites alternate dns servers proxy websites virtual private networks sneakernets and circumvention software tools solutions have differing ease of use speed security and risks most however rely on gaining access to an internet connection that is not subject to filtering often in a different jurisdiction not subject to the same censorship laws according to globalwebindex over 400 million people use virtual private networks to circumvent censorship or for increased level of privacy there are risks to using circumvention software or other methods to bypass internet censorship in some countries individuals that gain access to otherwise restricted content may be violating the law and if caught can be expelled from school fired from jobs jailed or subject to other punishments and loss of access
internet vigilantism is the phenomenon of vigilante acts taken through the internet the communication network or its service providers or carried out using applications world wide web e mail that depend on the internet the term encompasses vigilantism against scams crimes and non internet related behavior it was termed netilantism or digilantism in the wake of the boston marathon bombing some have suggested that the internet s lack of central control has prompted a tendency towards vigilante reactions against certain behaviors in the same way that they have prompted those behaviors to occur in the first place
internuclear ophthalmoplegia ino is a disorder of conjugate lateral gaze in which the affected eye shows impairment of adduction when an attempt is made to gaze contralaterally relative to the affected eye the affected eye adducts minimally if at all the contralateral eye abducts however with nystagmus additionally the divergence of the eyes leads to horizontal diplopia that is if the right eye is affected the patient will see double when looking to the left seeing two images side by side convergence is generally preserved
an interobject is a phenomenon of dreams in which there is a perception of something that is between two objects the term was coined by blechner in his book the dream frontier interobjects differ from typical dream condensations in which two objects are fused into one instead the condensation is incomplete some examples from the literature on dreams include a piece of hardware something like the lock of a door or perhaps a pair of paint frozen hinges and something between a record player and a balance scale interobjects are new creations derived from partially fused blends of other objects interobjects like disjunctive cognitions would sound bizarre or psychotic as perceptions in waking life but are accepted by most people as commonplace in dreams they have implications for both the theory of dreaming and the theory of categorization interobjects show the dreaming mind grouping items together whose connection may not be apparent to the waking mind something between an aqueduct or a swimming pool reveals the category of large man made architectural objects that contain water something between a cellphone and a baby reveals a category combining a relatively new piece of technology and a live infant both make noise when you don t expect it both are held close to your body and both can give you a feeling of connectedness scientists do not know if interobjects occur only in dreamlife or may occur as unconscious categorizations during waking life freud called interobjects intermediate and composite structures he thought they were inferior mental constructions and were scrupulously avoided in waking life most adults tend to regularize interobjects when discussing them in waking life children are better able to sustain interobjects in their original form a child told his father a dream in which he was in trouble at sea and a seal swam up to them they thought it was just a seal but then they looked and under the water it was a whole boat it was huge so they climbed onto the seal boat and it brought them to the shore of the mainland when the boy told his father the dream in the morning the father speaking like an adult who cannot tolerate contradictions said to him so really it was a boat a big safe boat the child holding fast to the integrity of his dream said it was a boat but it was still a big friendly seal this child had not yet learned to regularize his perceptions to fit the way the world works adults may learn to reject interobjects in waking life but still retain them in their dreams interobjects may have an elementary function in human thought by transgressing the normal mental categories described by eleanor rosch interobjects may be the origin of new ideas that would be harder to come by using only fully formed secondary process formations they may be one example of oneiric darwinism in which new thought mutations are created during dream life and rejected or retained in waking life depending on their usefulness jung held that if the dreamer walked about and acted like a person awake we would have the clinical picture of schizophrenia hobson concluded that dreams are more like delirium than schizophrenia both jung and hobson focus on how dreams are defective forms of normal waking life but in dreams our minds are in some ways able to function better than in waking life interobjects show the ability of the dreaming mind to notice how things that are very different nevertheless have features in common the mind then creates a new category which we might never have noticed in our waking life the woman who dreamed of a cellphone baby was creating a new category small objects that are held close to the body and that make noise at surprising and embarrassing times interobjects have been used creatively in advertising a set of rules known as a replacement template enabled a computer to create interobjects given a product p with a trait t the subject is asked to come up with a creative idea for an ad that conveys the message that p has t in a visual format an object s symbol which is universally identified with t is replaced with p the effect is enhanced if s is placed in a situation in which t is essential moreover the replacement operation can be iterated rather than p one can use parts of it or aspects of it or objects associated with it to replace the corresponding elements associated with s when asked to produce an ad for the world tennis cup tournament in jerusalem the computer generated a mosque with a dome that had a tennis ball texture in advertising on time performance for an airline the computer generated a cuckoo clock in which a jumbo jet pops out of the clock instead of a cuckoo both of these creations – the mosque tennis ball and the jumbo jet cuckoo clock – are interobjects
an interpretant in semiotics is the effect of a sign on someone who reads or comprehends it the concept of interpretant is part of charles sanders peirce s triadic theory of the sign for peirce the interpretant is an element that allows taking a representamen for the sign of an object and is also the effect of the process of semeiosis or signification peirce delineates three types of interpretants the immediate the dynamical and the final or normal
in computer programming the interpreter pattern is a design pattern that specifies how to evaluate sentences in a language the basic idea is to have a class for each symbol terminal or nonterminal in a specialized computer language the syntax tree of a sentence in the language is an instance of the composite pattern and is used to evaluate interpret the sentence for a client see also composite pattern
in computer systems programming an interrupt handler also known as an interrupt service routine or isr is a callback function in microcontroller firmware an operating system or a device driver whose execution is triggered by the reception of an interrupt in general interrupts and their handlers are used to handle high priority conditions that require the interruption of the current code the processor is executing interrupt handlers have a multitude of functions which vary based on what triggered the interrupt and the speed at which the interrupt handler completes its task for example pressing a key on a computer keyboard or moving the mouse triggers interrupts that call interrupt handlers which read the key or the mouse s position and copy the associated information into the computer s memory an interrupt handler is a low level counterpart of event handlers interrupt handlers are initiated by either hardware interrupts or software interrupt instructions and are used for servicing hardware devices and transitions between protected modes of operation such as system calls
interrupted aortic arch is a very rare heart defect affecting 3 per million live births in which the aorta is not completely developed there is a gap between the ascending and descending thoracic aorta in a sense it is the complete form of a coarctation of the aorta almost all patients also have other cardiac anomalies including a ventricular septal defect vsd aorto pulmonary window and truncus arteriosus interrupted aortic arch is often associated with digeorge syndrome
intersection syndrome is a painful condition that affects the thumb side of the forearm when inflammation occurs at the intersection of the muscle bellies of the abductor pollicis longus and extensor pollicis brevis cross over the extensor carpi radialis longus and the extensor carpi radialis brevis these 1 st and 2 nd dorsal muscle compartments intersect at this location hence the name the mechanism of injury is usually repetitive resisted extension as with rowing weight lifting or pulling intersection syndrome is often confused with another condition called dequervain s syndrome which is an irritation of the thumb sided set of tendons at the wrist called the first dorsal compartment
intersession is a short break or mini term between the traditional standard academic terms an intersession may be a period of a few weeks between semesters or quarters during which students can take short accelerated classes or complete other academic work
interspecific pregnancy literally pregnancy between species also called interspecies pregnancy or xenopregnancy is the pregnancy involving an embryo or fetus belonging to another species than the carrier strictly it excludes the situation where the fetus is a hybrid of the carrier and another species thereby excluding the possibility that the carrier is the biological mother of the offspring strictly interspecific pregnancy is also distinguished from endoparasitism where parasite offspring grow inside the organism of another species not necessarily in the womb it has no known natural occurrence but can be achieved artificially by transfer of embryos of one species into the womb of the female of another
interstitial cystitis ic also known as bladder pain syndrome bps is a type of chronic pain that affects the bladder symptoms include feeling the need to urinate right away needing to urinate often and pain with sex ic bps is associated with depression and lower quality of life many of those affected also have irritable bowel syndrome and fibromyalgia the cause of ic bps is unknown while it can it does not typically run in a family the diagnosis is usually based on the symptoms after ruling out other conditions typically the urine culture is negative ulceration or inflammation maybe seen on cystoscopy other conditions which can produce similar symptoms include urinary tract infection uti overactive bladder sexually transmitted infections endometriosis bladder cancer and prostatitis there is no cure for interstitial cystitis treatments that may improve symptoms include lifestyle changes medications or procedures lifestyle changes may include stopping smoking and reducing stress medications may include ibuprofen pentosan polysulfate or amitriptyline procedures may include bladder distention nerve stimulation or surgery pelvic floor exercises and long term antibiotics are not recommended in the united states and europe it is estimated that around 0 5 of people are affected women are affected about five times as often as men onset is typically in middle age the term interstitial cystitis first came into use in 1887
interstitial granulomatous dermatitis with arthritis is a condition that most commonly presents with symmetrical round to oval erythematous or violaceous plaques on the flanks axillae inner thighs and lower abdomen
interstitial granulomatous drug reaction is an uncommon yet under recognized pattern of adverse reactions to medication
interstitial lung disease ild or diffuse parenchymal lung disease dpld is a group of lung diseases affecting the interstitium the tissue and space around the air sacs of the lungs it concerns alveolar epithelium pulmonary capillary endothelium basement membrane perivascular and perilymphatic tissues it may occur when an injury to the lungs triggers an abnormal healing response ordinarily the body generates just the right amount of tissue to repair damage but in interstitial lung disease the repair process goes awry and the tissue around the air sacs alveoli becomes scarred and thickened this makes it more difficult for oxygen to pass into the bloodstream the term ild is used to distinguish these diseases from obstructive airways diseases prolonged ild may result in pulmonary fibrosis but this is not always the case idiopathic pulmonary fibrosis is interstitial lung disease for which no obvious cause can be identified idiopathic and is associated with typical radiographic basal and pleural based fibrosis with honeycombing and pathologic temporally and spatially heterogeneous fibrosis histopathologic honeycombing and fibroblastic foci findings in 2013 interstitial lung disease affected 595 000 people globally this resulted in 471 000 deaths
interstitial nephritis or tubulo interstitial nephritis is a form of nephritis affecting the interstitium of the kidneys surrounding the tubules this disease can be either acute meaning it occurs suddenly or chronic meaning it is ongoing and eventually ends in kidney failure
an interstitial pregnancy is a uterine but ectopic pregnancy the pregnancy is located outside of the uterine cavity in that part of the fallopian tube that penetrates the muscular layer of the uterus the term cornual pregnancy is sometimes used as a synonym but remains ambiguous as it is also applied to indicate the presence of a pregnancy located within the cavity in one of the two upper horns of a bicornuate uterus interstitial pregnancies have a higher mortality than ectopics in general
in cognitive psychology intertrial priming is an accumulation of the priming effect over multiple trials where priming is the effect of the exposure to one stimulus on subsequently presented stimuli intertrial priming occurs when a target feature the characteristic that distinguishes targets from non targets is repeated from one trial to the next and typically results in speeded response times to the target a target is the stimulus participants are required to search for for example intertrial priming occurs when the task is to respond to either a red or a green target and the response time to a red target is faster if the preceding trial also has a red target
an intertrigo is an inflammation rash of the body folds adjacent areas of skin the term intertrigo commonly refers to a bacterial fungal or viral infection that has developed at the site of broken skin due to such inflammation a frequent manifestation is candidal intertrigo an intertrigo usually develops from the chafing of warm moist skin in the areas of the inner thighs and genitalia the armpits under the breasts the underside of the belly behind the ears and the web spaces between the toes and fingers an intertrigo usually appears red and raw looking and may also itch ooze and be sore intertrigos occur more often among overweight individuals those with diabetes those restricted to bed rest or diaper use and those who use medical devices like artificial limbs that trap moisture against the skin also there are several skin diseases that can cause an intertrigo to develop such as dermatitis or inverse psoriasis
in music theory an interval is the difference between two pitches an interval may be described as horizontal linear or melodic if it refers to successively sounding tones such as two adjacent pitches in a melody and vertical or harmonic if it pertains to simultaneously sounding tones such as in a chord in western music intervals are most commonly differences between notes of a diatonic scale the smallest of these intervals is a semitone intervals smaller than a semitone are called microtones they can be formed using the notes of various kinds of non diatonic scales some of the very smallest ones are called commas and describe small discrepancies observed in some tuning systems between enharmonically equivalent notes such as c ♯ and d ♭ intervals can be arbitrarily small and even imperceptible to the human ear in physical terms an interval is the ratio between two sonic frequencies for example any two notes an octave apart have a frequency ratio of 2 1 this means that successive increments of pitch by the same interval result in an exponential increase of frequency even though the human ear perceives this as a linear increase in pitch for this reason intervals are often measured in cents a unit derived from the logarithm of the frequency ratio in western music theory the most common naming scheme for intervals describes two properties of the interval the quality perfect major minor augmented diminished and number unison second third etc examples include the minor third or perfect fifth these names describe not only the difference in semitones between the upper and lower notes but also how the interval is spelled the importance of spelling stems from the historical practice of differentiating the frequency ratios of enharmonic intervals such as g – g ♯ and g – a ♭
in numerical mathematics interval propagation or interval constraint propagation is the problem of contracting interval domains associated to variables of r without removing any value that is consistent with a set of constraints i e equations or inequalities it can be used to propagate uncertainties in the situation where errors are represented by intervals interval propagation considers an estimation problem as a constraint satisfaction problem
interval scheduling is a class of problems in computer science particularly in the area of algorithm design the problems consider a set of tasks each task is represented by an interval describing the time in which it needs to be executed for instance task a might run from 2 00 to 5 00 task b might run from 4 00 to 10 00 and task c might run from 9 00 to 11 00 a subset of intervals is compatible if no two intervals overlap for example the subset a c is compatible as is the subset b but neither a b nor b c are compatible subsets because the corresponding intervals within each subset overlap the interval scheduling maximization problem ismp is to find a largest compatible set a set of non overlapping intervals of maximum size the goal here is to execute as many tasks as possible in an upgraded version of the problem the intervals are partitioned into groups a subset of intervals is compatible if no two intervals overlap and moreover no two intervals belong to the same group i e the subset contains at most a single representative interval of each group the group interval scheduling decision problem gisdp is to decide whether there exists a compatible set in which all groups are represented the goal here is to execute a single representative task from each group gisdpk is a restricted version of gisdp in which the number of intervals in each group is at most k the group interval scheduling maximization problem gismp is to find a largest compatible set a set of non overlapping representatives of maximum size the goal here is to execute a representative task from as many groups as possible gismpk is a restricted version of gismp in which the number of intervals in each group is at most k this problem is often called jispk where j stands for job gismp is the most general problem the other two problems can be seen as special cases of it ismp is the special case in which each task belongs to its own group i e it is equal to gismp 1 gisdp is the problem of deciding whether the maximum is exactly equal to the number of groups
a intervertebral disc disorder is a condition that involves deterioration herniation or other dysfunction of an intervertebral disc as people age the nucleus pulposus begins to dehydrate which limits its ability to transfer and distribute loads between the vertebrae these loads are instead transferred non uniformly through the anulus fibrosus which undergoes progressive structural deterioration while this may not cause pain in some people in others one or both of these may cause chronic pain pain due to the inability of the dehydrating nucleus pulposus to absorb shock is called axial pain or disc space pain one generally refers to the gradual dehydration of the nucleus pulposus as degenerative disc disease when the anulus fibrosus tears due to an injury or the aging process the nucleus pulposus can begin to extrude through the tear this is called disc herniation near the posterior side of each disc all along the spine major spinal nerves extend out to different organs tissues extremities etc it is very common for the herniated disc to press against these nerves pinched nerve causing radiating pain numbness tingling and diminished strength and or range of motion in addition the contact of the inner nuclear gel with a nerve can also cause significant pain nerve related pain is called radicular pain herniated discs go by many names and these can mean different things to different medical professionals a slipped disc ruptured disc or a bulging disc can all refer to the same medical condition protrusions of the disc into the adjacent vertebra are known as schmorl s nodes
intestacy is the condition of the estate of a person who dies without having made a valid will or other binding declaration alternatively this may also apply where a will or declaration has been made but only applies to part of the estate the remaining estate forms the intestate estate intestacy law also referred to as the law of descent and distribution refers to the body of law statutory and case law that determines who is entitled to the property from the estate under the rules of inheritance
intestinal atresia is a malformation where there is a narrowing or absence of a portion of the intestine this defect can either occur in the small or large intestine
capillariasis is a disease in the group of helminthiasis diseases caused by the nematode capillaria philippinensis
intestinal malrotation is a congenital anomaly of rotation of the midgut embryologically the gut undergoes a complex rotation outside the abdomen as a result the small bowel is found predominantly on the right side of the abdomen the cecum is displaced from its usual position in the right lower quadrant into the epigastrium right hypochondrium the ligament of treitz is displaced inferiorly and rightward fibrous bands of ladd course over the vertical portion of the duodenum dii causing intestinal obstruction the small intestine has an unusually narrow base and therefore the midgut is prone to volvulus a twisting that can obstruct the mesenteric blood vessels and cause intestinal ischemia
intestinal neuronal dysplasia or neuronal intestinal dysplasia or nid is an inherited disease of the intestine that affects one in 3000 children and adults the intestine uses peristalsis to push its contents toward the anus ind sufferers have a problem with the motor neurons that lead to the intestine inhibiting this process and thus preventing digestion it can often be confused for hirschsprung s disease as both have similar symptoms it can be grouped into nid a and nid b with the a form affecting the sympathetic innervation and the b version affecting the parasympathetic innervation in 2002 martucciello g et al published the first analysis of associated anomalies in ind population is an important clinical approach to investigate possible pathogenetic correlations two recessive syndromes were identified 3 families the first was characterized by nid b intestinal malrotation and congenital short bowel the second by nid b short stature mental retardation and facial dysmorphism in this study gastrointestinal anomalies accounted for 67 4 of all associated disorders these data suggest a strong correlation between ind and intestinal development
intestinal parasites are parasites that can infect the gastro intestinal tract of humans and other animals they can live throughout the body but most prefer the intestinal wall means of exposure include ingestion of undercooked meat drinking infected water and skin absorption the two main types of intestinal parasites are those helminths and protozoa that reside in the intestines not all helminths and protozoa are intestinal parasites an intestinal parasite can damage or sicken its host via an infection which is called helminthiasis in the case of helminths
intestinal permeability is a term describing the control of material passing from inside the gastrointestinal tract through the cells lining the gut wall into the rest of the body the intestine normally exhibits some permeability which allows nutrients to pass through the gut while also maintaining a barrier function to keep potentially harmful substances such as antigens from leaving the intestine and migrating to the body more widely in a healthy human intestine small particles 4 å in radius can migrate through tight junction claudin pore pathways and particles up to 10 15 å 3 5 kda can transit through the paracellular space uptake route
intestinal pseudo obstruction is a clinical syndrome caused by severe impairment in the ability of the intestines to push food through it is characterized by the signs and symptoms of intestinal obstruction without any lesion in the intestinal lumen clinical features can include abdominal pain nausea severe distension vomiting dysphagia diarrhea and constipation depending upon the part of the gastrointestinal tract involved the condition can begin at any age and it can be a primary condition idiopathic or inherited or caused by another disease secondary it can be chronic or acute
intestinal spirochetosis also intestinal spirochetes colonic spirochetosis and colonic spirochetes is an infection of the colonic type mucosa with spirochete microorganisms
intimal hyperplasia is the thickening of the tunica intima of a blood vessel as a complication of a reconstruction procedure or endarterectomy intimal hyperplasia is the universal response of a vessel to injury and is an important reason of late bypass graft failure particularly in vein and synthetic vascular grafts
an intraarticular fracture is a bone fracture in which the break crosses into the surface of a joint this always result in some damage to the cartilage
an intracapsular fracture is a bone fracture located within the joint capsule examples of intracapsular fractures includes in the hip fractures of the femoral head and femoral neck
intracerebral hemorrhage ich also known as cerebral bleed is a type of intracranial bleed that occurs within the brain tissue or ventricles symptoms can include headache one sided weakness vomiting seizures decreased level of consciousness and neck stiffness often symptoms get worse over time fever is also common in many cases bleeding is present in both the brain tissue and the ventricles causes include brain trauma aneurysms arteriovenous malformations and brain tumors the largest risk factors for spontaneous bleeding are high blood pressure and amyloidosis other risk factors include alcoholism low cholesterol blood thinners and cocaine diagnosis is typically by ct scan other conditions that may present similarly include ischemic stroke treatment should typically be carried out in an intensive care unit guidelines recommended decreasing the blood pressure to a systolic of less than 140 mmhg blood thinners should be reversed if possible and blood sugar kept in the normal range surgery to place a ventricular drain may be used to treat hydrocephalus but corticosteroids should not be used surgery to remove the blood is useful in certain cases cerebral bleeding affects about 2 5 per 10 000 people each year it occurs more often in males and older people about 44 of those affected die within a month a good outcome occurs in about 20 of those affected strokes were first divided into their two major types bleeding and insufficient blood flow in 1823
an intracranial aneurysm also called cerebral or brain aneurysm is a cerebrovascular disorder in which weakness in the wall of a cerebral artery or vein causes a localized dilation or ballooning of the blood vessel aneurysms in the posterior circulation basilar artery vertebral arteries and posterior communicating artery have a higher risk of rupture basilar artery aneurysms represent only 3 5 of all intracranial aneurysms but are the most common aneurysms in the posterior circulation
intracranial hemorrhage ich also known as intracranial bleed is bleeding within the skull it includes intracerebral bleeds intraventricular bleeds and intraparenchymal bleeds subarachnoid bleeds epidural bleeds and subdural bleeds intracerebral bleeding affects 2 5 per 10 000 people each year
intracranial pressure icp is the pressure inside the skull and thus in the brain tissue and cerebrospinal fluid csf icp is measured in millimeters of mercury mmhg and at rest is normally 7 – 15 mmhg for a supine adult the body has various mechanisms by which it keeps the icp stable with csf pressures varying by about 1 mmhg in normal adults through shifts in production and absorption of csf changes in icp are attributed to volume changes in one or more of the constituents contained in the cranium csf pressure has been shown to be influenced by abrupt changes in intrathoracic pressure during coughing intraabdominal pressure valsalva maneuver and communication with the vasculature venous and arterial systems intracranial hypertension commonly abbreviated ih iicp or raised icp is elevation of the pressure in the cranium icp is normally 7 – 15 mm hg at 20 – 25 mm hg the upper limit of normal treatment to reduce icp may be needed
intractable pain also known as intractable pain disease or ip is a severe constant pain that is not curable by any known means and which causes a bed or house bound state and early death if not adequately treated usually with opioids and or interventional procedures it is not relieved by ordinary medical surgical nursing or pharmaceutical measures unlike the more common chronic pain it causes adverse biologic effects on the body s cardiovascular hormone and neurologic systems patients experience changes in testosterone estrogen cortisol thyroid hormones and or pituitary hormones both men and women require testosterone however many doctors neglect to test women for low testosterone untreated intractable pain can cause death
an intracule is a quantum mechanical mathematical function for the two electron density which depends not upon the absolute values of position or momentum but rather upon their relative values its use is leading to new methods in physics and computational chemistry to investigate the electronic structure of molecules and solids these methods are a development of density functional theory dft but with the two electron density replacing the one electron density
intraductal papillary mucinous neoplasm ipmn is a type of tumor neoplasm that grows within the pancreatic ducts intraductal and is characterized by the production of thick fluid by the tumor cells mucinous intraductal papillary mucinous neoplasms are important because if they are left untreated some of them progress to invasive cancer transform from a benign tumor to a malignant tumor just as colon polyps can develop into colon cancer if left untreated so too do some intraductal papillary mucinous neoplasms progress into an invasive pancreatic cancer intraductal papillary mucinous neoplasms can present an opportunity to treat a pancreatic tumor before it develops into an aggressive hard to treat cancer
intraductal papillary neoplasm of the bile duct also known as intraductal papillary biliary neoplasm is a rare type of liver cancer
intraductal papillomas of the breast are benign lesions with an incidence of approximately 2 3 in humans two types of intraductal papillomas are generally distinguished the central type develops near the nipple they are usually solitary and often arise in the period nearing menopause on the other hand the peripheral type are often multiple papillomas arising at the peripheral breasts and are usually found in younger women the peripheral type are associated with a higher risk of malignancy they are the most common cause of bloody nipple discharge in women age 20 40 and generally do not show up on mammography due to their small size so the next step in treatment would be a galactogram to guide the subsequent biopsy the masses are often too small to be palpated or felt a galactogram is therefore necessary to rule out the lesion excision is sometimes performed microdochectomy microdochotomy removal of a breast duct is the treatment of choice
intrahepatic cholestasis of pregnancy icp also known as obstetric cholestasis cholestasis of pregnancy jaundice of pregnancy and prurigo gravidarum is a medical condition in which cholestasis occurs during pregnancy it typically presents with troublesome itching and can lead to complications for both mother and fetus pruritis itching has long been considered to be a common symptom of pregnancy the vast majority of times itching is a minor annoyance caused by changes to the skin especially that of the abdomen however there are instances when itching is a symptom of icp this is usually most intense on the palms of the hands and the soles of the feet but can be widespread icp occurs most commonly in the third trimester but can begin at any time during the pregnancy
in organic chemistry an intramolecular diels alder cycloaddition is a diels – alder reaction in which the diene and a dienophile are both part of the same molecule the reaction leads to the formation of the same cyclohexene like structure as usual for a diels – alder reaction but as part of a more complex fused or bridged cyclic ring system
an intraneural perineurioma is a rare benign tumor within the sheath of a single nerve that grows but typically does not recur or metastasize these lesions are only composed of perineurial cells cloned from a single cell they are distinct from schwannoma and neurofibroma intraneural perineurioma is a neoplastic proliferation of perineurial cells with unique immunohistochemistry and ultrastructural features and it is distinct from other onion bulb schwann cell derived entities despite harboring molecular abnormalities of the long arm of chromosome 22 intraneural perineurioma has not been associated with neurofibromatosis
intranodal palisaded myofibroblastoma abbreviated ipm is a rare primary tumour of lymph nodes that classically presents as an inguinal mass it afflicts predominantly males of middle age
intraocular hemorrhage sometimes hemophthalmos or hemophthalmia is bleeding hemorrhage into the eyeball oculus in latin it may be the result of physical trauma direct injury to the eye or medical illness severe hemorrhage particularly when leading to rising pressure inside the eye may lead to blindness
intraocular pressure iop is the fluid pressure inside the eye tonometry is the method eye care professionals use to determine this iop is an important aspect in the evaluation of patients at risk from glaucoma most tonometers are calibrated to measure pressure in millimeters of mercury mmhg
intraoperative floppy iris syndrome ifis is a complication that may occur during cataract extraction in certain patients this syndrome is characterized by a flaccid iris which billows in response to ordinary intraocular fluid currents a propensity for this floppy iris to prolapse towards the area of cataract extraction during surgery and progressive intraoperative pupil constriction despite standard procedures to prevent this ifis has been associated with flomax tamsulosin a medication widely prescribed for urinary symptoms associated with benign prostatic hyperplasia tamsulosin is a selective alpha blocker that works by relaxing the bladder and prostatic smooth muscle as such it also relaxes the iris dilator muscle by binding to its postsynaptic nerve endings even if a patient has only taken tamsulosin once in their life that dose is enough to cause ifis during cataract extraction indefinitely ifis is also associated with finasteride a medication typically used as first line therapy for benign prostatic hyperplasia and androgenic alopecia the medication is also associated with cataract formation ifis may also be associated with other causes of small pupil like synechiae pseudoexfoliation and other medications used for conditions such as glaucoma diabetes and high blood pressure ifis does not usually cause significant changes in postoperative outcomes patients may experience more pain a longer recovery period and less improvement in visual acuity than a patient with an uncomplicated cataract removal the severity of the condition is not linked to the duration of tamsulosin intake
intraoral dental sinus also termed a parulis and commonly a gumboil is an oral lesion characterized by a soft erythematous papule red spot that develops on the alveolar process in association with a non vital tooth and accompanying dental abscess a parulis is made up of inflamed granulation tissue less commonly dental infections drain onto the surface of the skin forming a cutaneous sinus of dental origin
intraparenchymal hemorrhage iph is one form of intracerebral bleeding in which there is bleeding within brain parenchyma the other form is intraventricular hemorrhage ivh intraparenchymal hemorrhage accounts for approx 8 13 of all strokes and results from a wide spectrum of disorders it is more likely to result in death or major disability than ischemic stroke or subarachnoid hemorrhage and therefore constitutes an immediate medical emergency intracerebral hemorrhages and accompanying edema may disrupt or compress adjacent brain tissue leading to neurological dysfunction substantial displacement of brain parenchyma may cause elevation of intracranial pressure icp and potentially fatal herniation syndromes
intraretinal microvascular abnormalities irma are abnormalities of the blood vessels that supply the retina of the eye a sign of diabetic retinopathy irma can be difficult to distinguish from and is likely a precursor to retinal neovascularization one way to distinguish irma from retinal neovascularization is to perform fluorescein angiography since irma blood vessels are patent unlike neovascular vessels they do not leak and therefore exhibit hypofluorescence on fluorescein angiography irma is deeper in the retina than neovascularization has blurrier edges is more of a burgandy color as opposed to a red color does not appear on the optic disc and is usually seen after a shorter period of poorly controlled diabetes than neovascularization
intratubular germ cell neoplasia abbreviated itgcn or igcn and also known as testicular intratubular germ cell neoplasia and intratubular germ cell neoplasia of the testis is considered a precursor lesion for many types of testicular germ cell tumors the common unspecified variant of the entity was once considered to be a carcinoma in situ although the term carcinoma in situ is no longer preferred for itgcn unspecified type itgcnu lesions because they are not epithelial lesions the entity will be known as germ cell neoplasia in situ gcnis in the next who classification which is likely to be published in 2016
intrauterine epidermal necrosis is a cutaneous condition that is rapidly fatal characterized by skin erosions and ulcerations only
intrauterine growth retardation also known as intrauterine growth restriction iugr refers to poor growth of a fetus while in the mother s womb during pregnancy the causes can be many but most often involve poor maternal nutrition or lack of adequate oxygen supply to the fetus at least 60 of the 4 million neonatal deaths that occur worldwide every year are associated with low birth weight lbw caused by intrauterine growth restriction iugr preterm delivery and genetic chromosomal abnormalities demonstrating that under nutrition is already a leading health problem at birth intrauterine growth restriction can result in a baby being small for gestational age sga which is most commonly defined as a weight below the 10 th percentile for the gestational age at the end of pregnancy it can result in a low birth weight
intrauterine hypoxia occurs when the fetus is deprived of an adequate supply of oxygen it may be due to a variety of reasons such as prolapse or occlusion of the umbilical cord placental infarction and maternal smoking intrauterine growth restriction iugr may cause or be the result of hypoxia intrauterine hypoxia can cause cellular damage that occurs within the central nervous system the brain and spinal cord this results in an increased mortality rate including an increased risk of sudden infant death syndrome sids oxygen deprivation in the fetus and neonate have been implicated as either a primary or as a contributing risk factor in numerous neurological and neuropsychiatric disorders such as epilepsy adhd eating disorders and cerebral palsy
intravascular large b cell lymphoma ilbcl also referred to as angiotropic large cell lymphoma angiotropic large cell lymphoma intralymphatic lymphomatosis intravascular lymphomatosis and less specifically intravascular lymphoma and malignant angioendotheliomatosis is a rare form of lymphoma
intravascular papillary endothelial hyperplasia also known as masson s hemangio endotheliome vegetant intravasculaire masson s lesion masson s pseudoangiosarcoma masson s tumor and papillary endothelial hyperplasia may mimic angiosarcoma with lesions that are red or purplish 5 mm to 5 cm papules and deep nodules on the head neck or upper extremities
intravenous leiomyomatosis is a rare condition seen exclusively in women in which leiomyomata benign smooth muscle tumors are found in veins the masses are benign appearing but can spread throughout the venous system leaving the uterus and even cause death when growing into the heart from the ivc while the possibility that these arose de novo from the smooth muscle in the blood vessel wall was considered chromosomal analysis suggests a uterine origin intravenous leiomyomata are usually but not always associated with uterine fibroids and tend to recur this condition is related to benign metastasizing leiomyoma in which the masses appear in more distant locations such as the lung and lymph nodes
intravenous marijuana syndrome is a distinct short term clinical syndrome related to the intravenous injection of boiled cannabis broth which had been filtered through a cotton cloth the syndrome has at least 25 known cases in the english language literature but all of them prior to 1983 it is postulated that contamination perhaps from the cotton used to strain the liquid of the broth or from particulate plant matter getting through the straining method could be cause for the cases of illnesses
intraventricular hemorrhage ivh also known as intraventricular bleeding is a bleeding into the brain s ventricular system where the cerebrospinal fluid is produced and circulates through towards the subarachnoid space it can result from physical trauma or from hemorrhaging in stroke 30 of intraventricular hemorrhage ivh are primary confined to the ventricular system and typically caused by intraventricular trauma aneurysm vascular malformations or tumors particularly of the choroid plexus however 70 of ivh are secondary in nature resulting from an expansion of an existing intraparenchymal or subarachnoid hemorrhages intraventricular hemorrhage has been found to occur in 35 of moderate to severe traumatic brain injuries thus the hemorrhage usually does not occur without extensive associated damage and so the outcome is rarely good
in compiler theory an intrinsic function is a function available for use in a given programming language whose implementation is handled specially by the compiler typically it substitutes a sequence of automatically generated instructions for the original function call similar to an inline function unlike an inline function though the compiler has an intimate knowledge of the intrinsic function and can therefore better integrate it and optimize it for the situation this is also called builtin function in many languages compilers that implement intrinsic functions generally enable them only when the user has requested optimization falling back to a default implementation provided by the language runtime environment otherwise intrinsic functions are often used to explicitly implement vectorization and parallelization in languages which do not address such constructs altivec and openmp are examples of apis which use intrinsic functions to declare respectively vectorizable and multiprocessor aware operations during compilation the compiler parses the intrinsic functions and converts them into vector math or multiprocessing object code appropriate for the target platform
intron mediated enhancement ime is the ability of an intron sequence to enhance the expression of a gene containing that intron in particular the intron must be present in the transcribed region of the gene for enhancement to occur differentiating ime from the action of typical transcriptional enhancers descriptions of this phenomenon were first published in cultured maize cells in 1987 and the term intron mediated enhancement was subsequently coined in 1990 a number of publications have demonstrated that this phenomenon is conserved across eukaryotes including humans mice arabidopsis rice and c elegans however the mechanism s by which ime works are still not completely understood when testing to see whether any given intron enhances the expression of a gene it is typical to compare the expression of two constructs one containing the intron and one without it and to express the difference between the two results as a fold increase in enhancement further experiments can specifically point to ime as the cause of expression enhancement one of the most common is to move the intron upstream of the transcription start site removing it from the transcript if the intron can no longer enhance expression then inclusion of the intron in the transcript is important and the intron probably causes ime not all introns enhance gene expression but those that do can enhance expression between 2 – and 1 000 – fold relative to an intronless control in arabidopsis and other plant species the imeter has been developed to calculate the likelihood that an intron sequence will enhance gene expression it does this by calculating a score based on the patterns of nucleotide sequences within the target sequence the position of an intron within the transcript is also important the closer an intron is to the start 5 end of a transcript the greater its enhancement of gene expression
an intussusception is a medical condition in which a part of the intestine invaginates folds into into another section of intestine similar to the way the parts of a collapsible telescope retract into one another this can often result in an obstruction the part that prolapses into the other is called the intussusceptum and the part that receives it is called the intussuscepiens intussusception is a medical emergency and a patient should be seen immediately to reduce risk
in computer science an invariant is a condition that can be relied upon to be true during execution of a program or during some portion of it it is a logical assertion that is held to always be true during a certain phase of execution for example a loop invariant is a condition that is true at the beginning and end of every execution of a loop
invasive carcinoma of no special type nst also known as invasive ductal carcinoma or ductal nos and previously known as invasive ductal carcinoma not otherwise specified nos is a group of breast cancers that do not have the specific differentiating features those that have these features belong to other types in this group are pleomorphic carcinoma carcinoma with osteoclast like stromal giant cells carcinoma with choriocarcinomatous features and carcinoma with melanotic features it is a diagnosis of exclusion which means that for the diagnosis to be made all the other specific types must be ruled out
invasive lobular carcinoma accounts for 5 10 of invasive breast cancer the histologic patterns include overall the five year survival rate of invasive lobular carcinoma was approximately 85 in 2003 loss of e cadherin is common in lobular carcinoma but is also seen in other breast cancers treatment includes surgery and adjuvant therapy
invasive urothelial carcinoma is a type of transitional cell carcinoma tcc also urothelial cell carcinoma or ucc and is a type of cancer that develops in the urinary system the kidney urinary bladder and accessory organs it is the most common type of bladder cancer and cancer of the ureter urethra and urachus invasive urothelial carcinoma originates from tissue lining the inner surface of these hollow organs transitional epithelium it can extend from the kidney collecting system to the bladder generally speaking invasive urotherlial carcinoma is a cancer of the urothelium that develops from epithelial cells lining the lumens of urinary system organs the term carcinoma from the greek karkinos or crab and oma growth is a type of cancer a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body and that generally arises from cells originating in the endodermal or ectodermal germ layer during embryogenesis is a form of cancer of one type of urothelial lesion and a form of papillary urothelial lesions urothelium or uroepithelium is an example of transitional epithelium it is the type of epithelium that lines much of the urinary tract including the renal pelvis the ureters the bladder and parts of the urethra
the inventor s paradox is a phenomenon that occurs in seeking a solution to a given problem instead of solving a specific type of problem which would seem intuitively easier it can be easier to solve a more general problem which covers the specifics of the sought after solution the inventor s paradox has been used to describe phenomena in mathematics programming and logic as well as other areas that involve critical thinking
in economics an inverse demand function p f − 1 q is a function that maps the quantity of output demanded to the market price dependent variable for that output quantity demanded q is a function of price the inverse demand function treats price as a function of quantity demanded and is also called the price function note that the inverse demand function is not the reciprocal of the demand function — the word inverse refers to the mathematical concept of an inverse function
inverse dynamics is an inverse problem it commonly refers to either inverse rigid body dynamics or inverse structural dynamics inverse rigid body dynamics is a method for computing forces and or moments of force torques based on the kinematics motion of a body and the body s inertial properties mass and moment of inertia typically it uses link segment models to represent the mechanical behaviour of interconnected segments such as the limbs of humans animals or robots where given the kinematics of the various parts inverse dynamics derives the minimum forces and moments responsible for the individual movements in practice inverse dynamics computes these internal moments and forces from measurements of the motion of limbs and external forces such as ground reaction forces under a special set of assumptions
the inverse electron demand diels – alder reaction or dainv or iedda is an organic chemical reaction in which two new chemical bonds and a six membered ring are formed it is related to the diels – alder reaction but unlike the diels – alder or da reaction the dainv is a cycloaddition between an electron rich dienophile and an electron poor diene during a dainv reaction three pi bonds are broken and two sigma bonds and one new pi bond are formed a prototypical dainv reaction is shown on the right dainv reactions often involve heteroatoms and can be used to form heterocyclic compounds this makes the dainv reaction particularly useful in natural product syntheses where the target compounds often contain heterocycles recently the dainv reaction has been used to synthesize a drug transport system which targets prostate cancer
in mathematics an inverse function is a function that reverses another function if the function f applied to an input x gives a result of y then applying its inverse function g to y gives the result x and vice versa i e f x y if and only if g y x as a simple example consider the real valued function of a real variable given by f x 5 x − 7 thinking of this as a step by step procedure namely take a number x multiply it by 5 then subtract 7 from the result to reverse this and get x back from some output value say y we should undo each step in reverse order in this case that means that we should add 7 to y and then divide the result by 5 in functional notation this inverse function would be given by with y 5 x − 7 we have that f x y and g y x not all functions have inverse functions in order for a function f x → y to have an inverse it must have the property that for every y in y there must be one and only one x in x so that f x y this property ensures that a function g y → x will exist having the necessary relationship with f
in mathematics the inverse problem for lagrangian mechanics is the problem of determining whether a given system of ordinary differential equations can arise as the euler – lagrange equations for some lagrangian function there has been a great deal of activity in the study of this problem since the early 20 th century a notable advance in this field was a 1941 paper by the american mathematician jesse douglas in which he provided necessary and sufficient conditions for the problem to have a solution these conditions are now known as the helmholtz conditions after the german physicist hermann von helmholtz
inverse psoriasis or flexural psoriasis is a form of psoriasis that selectively and often exclusively involves the folds recesses and flexor surfaces such as the ears axillae groins inframammary folds navel intergluteal crease penis lips and webspaces
in mathematics and physics the inverse scattering problem is the problem of determining characteristics of an object based on data of how it scatters incoming radiation or particles it is the inverse problem to the direct scattering problem which is to determine how radiation or particles are scattered based on the properties of the scatterer soliton equations are a class of partial differential equations which can be studied and solved by a method called the inverse scattering transform which reduces the nonlinear pdes to a linear inverse scattering problem the nonlinear schrödinger equation the korteweg – de vries equation and the kp equation are examples of soliton equations in one space dimension the inverse scattering problem is equivalent to a riemann hilbert problem since its early statement for radiolocation many applications have been found for inverse scattering techniques including echolocation geophysical survey nondestructive testing medical imaging quantum field theory
inverted follicular keratosis is a skin condition characterized by asymptomatic firm white – tan to pink papules and considered as a subtype of seborrheic keratosis
the inverted hammer is a type of candlestick pattern found after a downtrend and is usually taken to be a trend reversal signal the inverted hammer looks like an upside down version of the hammer candlestick pattern and when it appears in an uptrend is called a shooting star the pattern is made up of a candle with a small lower body and a long upper wick which is at least two times as large as the short lower body the body of the candle should be at the low end of the trading range and there should be little or no lower wick in the candle the long upper wick of the candlestick pattern indicates that the buyers drove prices up at some point during the period in which the candle was formed but encountered selling pressure which drove prices back down to close near to where they opened when encountering an inverted hammer traders often check for a higher open and close on the next period to validate it as a bullish signal
an inverted nipple occasionally invaginated nipple is a condition where the nipple instead of pointing outward is retracted into the breast in some cases the nipple will be temporarily protruded if stimulated women and men can have inverted nipples
an inverted papilloma is a type of tumor in which surface epithelial cells grow downward into the underlying supportive tissue it may occur in the nose and or sinuses or in the urinary tract bladder renal pelvis ureter urethra when it occurs in the nose or sinuses it may cause symptoms similar to those caused by sinusitis such as nasal congestion when it occurs in the urinary tract it may cause blood in the urine
in macroeconomics investment is the amount purchased per unit time of goods which are not consumed at the present time types of investment include residential investment in housing that will provide a flow of housing services over an extended time non residential fixed investment in things such as new machinery or factories human capital investment in workforce education and inventory investment the accumulation intentional or unintentional of goods inventories in measures of national income and output gross investment represented by the variable i is a component of gross domestic product gdp given in the formula gdp c i g nx where c is consumption g is government spending and nx is net exports given by the difference between the exports and imports x − m thus investment is everything that remains of total expenditure after consumption government spending and net exports are subtracted i e i gdp − c − g − nx net investment deducts depreciation from gross investment net fixed investment is the value of the net increase in the capital stock per year fixed investment as expenditure over a period of time e g per year is not capital but rather leads to changes in the amount of capital the time dimension of investment makes it a flow by contrast capital is a stock — that is accumulated net investment up to a point in time investment is often modeled as a function of income and interest rates given by the relation i f y r an increase in income encourages higher investment whereas a higher interest rate may discourage investment as it becomes more costly to borrow money even if a firm chooses to use its own funds in an investment the interest rate represents an opportunity cost of investing those funds rather than lending out that amount of money for interest
investment control or investment controlling is a monitoring function within the asset management portfolio management or investment management it is concerned with independently supervising and monitoring the quality of asset management accounts with the aim of ensuring performance and quality in order to provide the required benefit for the asset management client dependent on setup investment controlling not only encompasses controlling activities but also can include areas from compliance to performance review investment controlling aspects can also be taken into consideration by asset management clients or investment advisers consultants and consequently it is likely that these stakeholders also run certain investment controlling activities
invisible lost time ilt related to routine rig drilling operations is the difference between actual operational duration and a best practice target it is invisible as it does not appear on any conventional morning reports the measurement of invisible lost time starts by analyzing each individual key performance indicator kpi that can be produced by a particular crew drilling crew casing crew etc or by a machine automated operation or a combination of both the measurement of invisible lost time was first developed and used by statoil and tde bobt the time needed when drilling and producing the hole flat time the necessary time needed for constructing a well besides the bobt bha handling tripping running casing bop work drilling connections etc lt – the deviation from plan problem time due to unexpected unplanned events like hole problems tool failures rig repair etc
involutional lipoatrophy is a cutaneous condition and is an idiopathic lipoatrophy characterized clinically by non inflammatory focal loss of fat idiopathic localized involutional lipoatrophy ilil is a rare and nosologically imprecise condition characterized by a focal loss of subcutaneous tissue on one or several sites occurring without any significant triggering factor or auto immune background and regressing spontaneously within a few months
iodine deficiency is a lack of the trace element iodine an essential nutrient in the diet it may result in a goiter sometimes as an endemic goiter as well as cretinism due to untreated congenital hypothyroidism which results in developmental delays and other health problems iodine deficiency is an important public health issue as it is a preventable cause of intellectual disability iodine is an essential dietary mineral the thyroid hormones thyroxine and triiodothyronine contain iodine in areas where there is little iodine in the diet typically remote inlandareas where no marine foods are eaten iodine deficiency is common it is also common in mountainous regions of the world where food is grown in iodine poor soil prevention includes adding small amounts of iodine to table salt a product known as iodized salt iodine compounds have also been added to other foodstuffs such as flour water and milk in areas of deficiency seafood is also a well known source of iodine iodine deficiency resulting in goiter occurs in 187 million people globally as of 2010 2 7 of the population it resulted in 2700 deaths in 2013 up from 2100 deaths in 1990
iodine deficiency is a widespread problem in western southern and eastern parts of china as their iodized salt intake level is much lower than the average national level iodine deficiency is a range of disorders that affect many different populations it is estimated that idds affect between 800 million and 2 billion people worldwide countries have spent millions of dollars in implementing iodized salt as a means to counteract the iodine deficiencies prevalent today with china accounting for 40 of the total population it bears a large portion of those who are iodine deficient iodine is a micronutrient the body needs to properly produce thyroid hormones the human body is not able to produce it and iodine is an essential nutrient iodine is not readily available in many foods thus making it difficult for many people to obtain it one particular source found in great supply is ocean water although it is not an effective dietary source iodine deficiency diseases idds are able to develop before birth so it is crucial for all populations to have sufficient levels of the micronutrient and prevent such diseases from developing early on
iododermas are caused by iodides with the most common sources of exposure being oral and intravenous contrast materials used to treat thyroid disease the most common type of eruption is an acneiform eruption with numerous acutely inflamed follicular pustules each surrounded by a ring of hyperemia
iodolactonization or more generally halolactonization is an organic reaction that forms a ring the lactone by the addition of an oxygen and iodine across a carbon carbon double bond the reaction was first reported by m j bougalt in 1904 and has since become one of the most effective ways to synthesize lactones strengths of the reaction include the mild conditions and incorporation of the versatile iodine atom into the product iodolactonizationintroduction iodolactonization has been used in the synthesis of many natural products including those with medicinal applications such as vernoplepin and vernomenin two compounds used in tumor growth inhibition and vibralactone a pancreatic lipase inhibitor that has been used in the treatment of obesity iodolactonization has also been used by e j corey to synthesize numerous prostaglandins
in chemistry ion association is a chemical reaction whereby ions of opposite electrical charge come together in solution to form a distinct chemical entity ion associates are classified according to the number of ions that associate with each other as ion pairs ion triplets etc ion pairs are also classified according to the nature of the interaction as contact solvent shared or solvent separated the most important factor to determine the extent of ion association is the dielectric constant of the solvent ion associates have been characterized by means of vibrational spectroscopy
ion cyclotron resonance is a phenomenon related to the movement of ions in a magnetic field it is used for accelerating ions in a cyclotron and for measuring the masses of an ionized analyte in mass spectrometry particularly with fourier transform ion cyclotron resonance mass spectrometers it can also be used to follow the kinetics of chemical reactions in a dilute gas mixture provided these involve charged species
the ireland – claisen rearrangement is a chemical reaction of an allylic ester with strong base to give an γ δ unsaturated carboxylic acid the ireland claisen rearrangement several reviews have been published
iridocorneal endothelial syndromes iridocorneal endothelial ice syndromes are a spectrum of diseases characteriezed by slowly progressive abnormalities of the corneal endothelium and features including corneal edema iris distortion and secondary angle closure glaucoma 1 2 4 ice syndromes are predominantly unilateral and nonhereditary 1 2 4 the condition occurs in predominantly middle aged women 1 3 4 mechanism the exact mechanism is unknown however there appears to be a component of abnormal corneal endothelium that proliferates onto the iris forming a membrane that then obstructs the trabecular meshwork leading to iris distortion 1 2 nodule formation can also occur when the abnormal corneal endothelium causes contractions around the iris stroma 1 herpesvirus dna has been identified in some patients following keratoplasty suggesting the possibility that herpes simplex virus may induce the abnormal endotheliazation in the anterior chamber angle and on the surface of the iris 2 3 5 signs and symptoms many cases are asymptomatic however patients many have decreased vision glare monocular diplopia or polyopia and noticable iris changes 2 6 on exam patients have normal to decreased visual acuity and a “ beaten metal appearance ” of the corneal endothelium corneal edema increased intraocular pressure peripheral anterior synechiae and iris changes 1 2 6 variations the chandler variant of ice is characterized by pathology on the inner surface of the cornea leading to abnormal endothelial pump function 2 6 other features include possible mild iris changes corneal edema and normal to slight elevations in intraocular pressure 1 6 cogan reese variant is characterized by multiple pigmented iris nodules 2 6 this variant is most commonly unilateral and seen in middle aged females 2 treatment penetrating karatoplasty and endothelial keratoplasty can be used as treatments for severe cases of ice 2 8 because glaucoma and elevated intraocular pressure are often present in ice patients long term follow up may be needed to ensure adequate intraocular pressures are maintained 2 7 prognosis the disease is chronic and often progresses slowly prognosis is generally poor when associated with glaucoma 1 2
iridodialysis sometimes known as a coredialysis is a localized separation or tearing away of the iris from its attachment to the ciliary body
iridogoniodysgenesis dominant type type 1 irid 1 refers to a spectrum of diseases characterized by malformations of the irido corneal angle of the anterior chamber of the eye iridogoniodysgenesis is the result of abnormal migration or terminal induction of neural crest cells these cells lead to formation of most of the anterior segment structures of the eye corneal stroma endothelium iris stroma trabeculum symptoms iris hypoplasis goniodysgenesis and juvenile glaucoma glaucoma phenotype that maps to 6 p 25 results from mutations in the forkhead transcription factor gene foxc 1 transmission autosomal dominant pattern with complete penetrance and variable expressivity first reported by berg 1932 treatment of glaucoma in iridogoniodysgenesis is primarily surgical it is listed as a rare disease by the office of rare diseases ord this means that iridogoniodysgenesis dominant type or a subtype of iridogoniodysgenesis dominant type affects less than 200 000 people in the us population
iridoplegia is the paralysis of the sphincter of the iris it can occur in due to direct orbital injury which may result in short lived blurred vision
irlen syndrome occasionally referred to as scotopic sensitivity syndrome sss or meares irlen syndrome very rarely as asfedia and recently also as visual stress is a proposed disorder of vision it is not recognised by any scientific or medical body
iron deficiency anemia also spelled iron deficiency anaemia is anemia caused by a lack of iron anemia is defined as a decrease in the amount of red blood cells rbcs or hemoglobin in the blood when anemia comes on slowly the symptoms are often vague and may include feeling tired weakness shortness of breath or poor ability to exercise anemia that comes on quickly often has greater symptoms which may include confusion feeling like one is going to pass out and increased thirst there needs to be significant anemia before a person becomes noticeably pale there may be additional symptoms depending on the underlying cause it is caused by insufficient dietary intake and absorption of iron or iron loss from bleeding bleeding can be from a range of sources such as the intestinal uterine or urinary tract the most common cause of iron deficiency anemia in children in developing countries is parasitic worms worms cause intestinal bleeding which is not always noticeable in feces and is especially damaging to children malaria hookworms and vitamin a deficiency contribute to anemia during pregnancy in most underdeveloped countries in women over 50 years old the most common cause of iron deficiency anemia is chronic gastrointestinal bleeding from nonparasitic causes such as gastric ulcers duodenal ulcers or gastrointestinal cancer iron deficiency causes approximately half of all anemia cases worldwide and affects women more often than men iron deficiency anemia affected 1 2 billion people in 2013 in 2013 anemia due to iron deficiency resulted in about 183 000 deaths – down from 213 000 deaths in 1990
iron deficiency is the most common nutritional deficiency in the world iron is present in all cells in the human body and has several vital functions such as carrying oxygen to the tissues from the lungs as a key component of the hemoglobin protein acting as a transport medium for electrons within the cells in the form of cytochromes facilitating oxygen use and storage in the muscles as a component of myoglobin and as an integral part of enzyme reactions in various tissues too little iron can interfere with these vital functions and lead to morbidity and death total body iron averages approximately 3 8 g in men and 2 3 g in women in blood plasma iron is carried tightly bound to the protein transferrin there are several mechanisms that control human iron metabolism and safeguard against iron deficiency the main regulatory mechanism is situated in the gastrointestinal tract when loss of iron is not sufficiently compensated by adequate intake of iron from the diet a state of iron deficiency develops over time when this state is uncorrected it leads to iron deficiency anemia before anemia occurs the medical condition of iron deficiency without anemia is called latent iron deficiency lid or iron deficient erythropoiesis ide untreated iron deficiency can lead to iron deficiency anemia — a common type of anemia anemia is a condition characterized by inadequate red blood cells erythrocytes or hemoglobin iron deficiency anemia occurs when the body lacks sufficient amounts of iron resulting in reduced production of the protein hemoglobin hemoglobin binds to oxygen thus enabling red blood cells to supply oxygenated blood throughout the body children pre menopausal women women of child bearing age and people with poor diet are most susceptible to the disease most cases of iron deficiency anemia are mild but if not treated can cause problems like fast or irregular heartbeat complications during pregnancy and delayed growth in infants and children
iron fe deficiency is a plant disorder also known as lime induced chlorosis it can be confused with manganese deficiency a deficiency in the soil is rare but iron can be unavailable for absorption if soil ph is not between about 5 and 6 5 a common problem is excessive alkalinity of the soil the ph is above 6 5 also iron deficiency can develop if the soil is too waterlogged or has been overfertilised elements like calcium zinc manganese phosphorus or copper can tie up iron if they are present in high amounts iron is needed to produce chlorophyll hence its deficiency causes chlorosis for example iron is used in the active site of glutamyl trna reductase an enzyme needed for the formation of 5 aminolevulinic acid which is a precursor of heme and chlorophyll
genes involved in iron metabolism disorders include hfe and tfr 2 hepcidin is the master regulator of iron metabolism and therefore most genetic forms of iron overload can be thought of as relative hepcidin deficiency in one way or another for instance a severe form of iron overload juvenile hemochromatosis is a result of severe hepcidin deficiency the majority of cases are caused by mutations in the hemojuvelin gene hjv or rgmc repulsive guidance molecule c the exceptions people who have mutations in the gene for ferroportin prove the rule these people have plenty of hepcidin but their cells lack the proper response to it so in people with ferroportin proteins that transport iron out of cells without responding to hepcidin s signals to stop they have a deficiency in the action of hepcidin if not in hepcidin itself but the exact mechanisms of most of the various forms of adult hemochromatosis which make up most of the genetic iron overload disorders remain unsolved so while researchers have been able to identify genetic mutations causing several adult variants of hemochromatosis they now must turn their attention to the normal function of these mutated genes these genes represent multiple steps along the pathway of iron regulation from the body s ability to sense iron to the body s ability to regulate uptake and storage working out the functions of each gene in this pathway will be an important tool for finding new methods of treating genetic disorders as well as for understanding the basic workings of the pathway so though many mysteries of iron metabolism remain the discovery of hepcidin already allows a much better understanding of the nature of iron regulation and makes researchers optimistic that many more breakthroughs in this field are soon to come
iron metallic discoloration occurred more frequently in the past when soluble iron compounds were used in the treatment of allergic contact and other dermatitis and in eroded areas iron was sometimes deposited in the skin like a tattoo
iron rings are heavy metal rings used in martial arts for various training purposes metal rings have a long history of being used in yau kung mun hung gar and other styles for weight training to harden the muscle skin or bone or strengthen the arms and fists
iron supplements are dietary supplements containing iron that can be prescribed by a doctor for a medical reason or purchased from a vitamin shop drug store etc they are primarily used to treat anemia or other iron deficiencies there are three ways that it can be delivered orally intravenously or intramuscularly the first iron pills were commonly known as blaud s pills which were named after p blaud of beaucaire the french physician who introduced and started the use of these medications as a treatment for patients with anemia
irregular menstruation is a menstrual disorder whose manifestations include irregular cycle lengths as well as metrorrhagia vaginal bleeding between expected periods
irregular sleep – wake rhythm is a rare form of circadian rhythm sleep disorder it is characterized by numerous naps throughout the 24 hour period no main nighttime sleep episode and irregularity from day to day sufferers have no pattern of when they are awake or asleep may have poor quality sleep and often may be very sleepy while they are awake the total time asleep per 24 hours is normal for the person s age the disorder is serious — an invisible disability it can create social familial and work problems making it hard for a person to maintain relationships and responsibilities and may make a person home bound and isolated
irreligion adjective form non religious or irreligious is the absence indifference rejection of or hostility towards religion when characterized as the rejection of religious belief it encompasses atheism agnosticism deism religious dissidence and secular humanism when characterized as the absence of religious belief it may also include spiritual but not religious pandeism ignosticism nontheism pantheism panentheism and freethought when characterized as indifference to religion it is known as apatheism when characterized as hostility towards religion it encompasses antitheism antireligion and misotheism irreligion may include some forms of theism depending on the religious context it is defined against for example in 18 th century europe the epitome of irreligion was deism according to pew research center projections the nonreligious though temporarily increasing will ultimately decline significantly by 2050 because of lower reproductive rates and ageing
irreligion in brazil is a new but increasing phenomenon the official brazilian census gives since 1970 sem religião portuguese no religion as an option of self description for people who do not consider themselves members of any specific religion including non affiliated theists and deists according to the 2000 census there were 12 5 million irreligious people in the country 7 3 of the total population as of 2010 there were 15 3 million irreligious people 8 of the population the constitution of brazil assigns secularism as the default position of the law and government in relation to religious matters art 19 i and grants freedom of religion and thought to its citizens art 5 vi non profit organization brazilian association of atheists and agnostics actively tries to promote secularism and help irreligious people victims of prejudice
irritable bowel syndrome ibs is a group of symptoms — including abdominal pain and changes in the pattern of bowel movements without any evidence of underlying damage these symptoms occur over a long time often years it has been classified into four main types depending on if diarrhea is common constipation is common both are common or neither occurs very often ibs d ibs c ibs m or ibs u respectively ibs negatively affects quality of life and may result in missed school or work disorders such as anxiety major depression and chronic fatigue syndrome are common among people with ibs the causes of ibs are not clear theories include gut – brain axis problems small intestinal bacterial overgrowth genetic factors food sensitivity and gut motility problems onset may be triggered by an intestinal infection or stressful life event ibs is a functional gastrointestinal disorder diagnosis is based on signs and symptoms in the absence of worrisome features worrisome features include onset at greater than 50 years of age weight loss blood in the stool or a family history of inflammatory bowel disease other conditions that may present similarly include celiac disease microscopic colitis inflammatory bowel disease bile acid malabsorption and colon cancer there is no cure for ibs treatment is carried out to improve symptoms this may including dietary changes medication probiotics and counselling dietary measures include increasing soluble fiber intake a gluten free diet or a diet low in fermentable oligosaccharides disaccharides monosaccharides and polyols fodmap the medication loperamide may be used to help with diarrhea while laxatives may be used to help with constipation antidepressants may improve overall symptoms and pain patient education and a good doctor – patient relationship are an important part of care about 10 to 15 of people in the developed world are believed to be affected by ibs it is more common in south america and less common in southeast asia it is twice as common in women as men and typically occurs before age 45 the condition appears to become less common with age ibs does not affect life expectancy or lead to other serious diseases the first description of the condition was in 1820 while the current term irritable bowel syndrome came into use in 1944
irritant contact dermatitis is a form of contact dermatitis that can be divided into forms caused by chemical irritants and those caused by physical irritants
irritant diaper dermatitis is a generic term applied to skin rashes in the diaper area that are caused by various skin disorders and or irritants generic rash or irritant diaper dermatitis idd is characterized by joined patches of erythema and scaling mainly seen on the convex surfaces with the skin folds spared diaper dermatitis with secondary bacterial or fungal involvement tends to spread to concave surfaces i e skin folds as well as convex surfaces and often exhibits a central red beefy erythema with satellite pustules around the border it is usually considered a form of irritant contact dermatitis despite the word diaper in the name the dermatitis is not due to the diaper itself but to the materials trapped by the diaper usually feces allergic contact dermatitis has also been suggested but there is little evidence for this etiology the term diaper candidiasis is used when a fungal origin is identified the distinction is critical because the treatment antifungals is completely different
irritant folliculitis is a cutaneous condition and usually occurs following the application of topical medications
irritated seborrheic keratosis also known as basosquamous cell acanthoma and inflamed seborrheic keratosis is a common benign cutaneous condition characterized by a skin lesion with a dull or lackluster surface
irruptive growth sometimes called malthusian growth is a growth pattern over time defined by population explosions and subsequent sharp population crashes or diebacks it is an extension of the malthusian growth model specifically the growth pattern that causes a malthusian catastrophe and can occur when populations overshoot their carrying capacity a phenomenon typically associated with r strategists populations which exhibit irruptive growth do not stabilize around their carrying capacity a feature of logistic growth irruptive growth occurs when a species reproduces more rapidly than the environment is capable of supporting with the available resources irruptive growth is studied in population ecology an irruption is any sudden change in the population density of an organism
irukandji syndrome is a condition induced by venomization by the sting of carukia barnesi a species of irukandji jellyfish and certain other box jellyfish unless immediate medical action is taken victims can go into cardiac arrest and die the syndrome was given its name in 1952 by hugo flecker after the aboriginal irukandji people who live in palm cove north of cairns queensland australia where stings are common
irvine gass syndrome pseudophakic cystoid macular edema or postcataract cme is one of the most common causes of visual loss after cataract surgery the syndrome is named in honor of s rodman irvine and j donald m gass the incidence is more common in older types of cataract surgery where postcataract cme could occur in 20 60 of patients but with modern cataract surgery incidence of irvine gass syndrome have reduced significantly
the isay reaction is an organic reaction in which certain diaminopyrimidines are transformed into pterins by condensation with a 1 2 dicarbonyl compound such as 2 3 butanedione the reaction is named after otto isay
ischemia is a restriction in blood supply to tissues causing a shortage of oxygen and glucose needed for cellular metabolism to keep tissue alive ischemia is generally caused by problems with blood vessels with resultant damage to or dysfunction of tissue it also means local anemia in a given part of a body sometimes resulting from congestion such as vasoconstriction thrombosis or embolism ischemia comprises not only insufficiency of oxygen but also reduced availability of nutrients and inadequate removal of metabolites the word is from greek ἴσχαιμος iskhaimos staunching blood from ἴσχω iskhο keep back restrain and αἷμα haima blood
ischemic cardiomyopathy is a type of cardiomyopathy caused by a narrowing of the coronary arteries which supply blood to the heart typically patients with ischemic cardiomyopathy have a history of acute myocardial infarction however it may occur in patients with coronary artery disease but without a past history of acute myocardial infarction this cardiomyopathy is one of the leading causes of sudden cardiac death
ischemic colitis also spelled ischaemic colitis is a medical condition in which inflammation and injury of the large intestine result from inadequate blood supply although uncommon in the general population ischemic colitis occurs with greater frequency in the elderly and is the most common form of bowel ischemia causes of the reduced blood flow can include changes in the systemic circulation e g low blood pressure or local factors such as constriction of blood vessels or a blood clot in most cases no specific cause can be identified ischemic colitis is usually suspected on the basis of the clinical setting physical examination and laboratory test results the diagnosis can be confirmed via endoscopy or by using sigmoid or endoscopic placement of a visible light spectroscopic catheter see ischemic colitis can span a wide spectrum of severity most patients are treated supportively and recover fully while a minority with very severe ischemia may develop sepsis and become critically sometimes fatally ill patients with mild to moderate ischemic colitis are usually treated with iv fluids analgesia and bowel rest that is no food or water by mouth until the symptoms resolve those with severe ischemia who develop complications such as sepsis intestinal gangrene or bowel perforation may require more aggressive interventions such as surgery and intensive care most patients make a full recovery occasionally after severe ischemia patients may develop long term complications such as a stricture or chronic colitis
ischemic hepatitis also known as shock liver is a condition defined as an acute liver injury caused by insufficient blood flow and consequently insufficient oxygen delivery to the liver the decreased blood flow perfusion to the liver is usually due to shock or low blood pressure however local causes involving the hepatic artery that supplies oxygen to the liver such as a blood clot in the hepatic artery can also cause ischemic hepatitis
ischemic optic neuropathy ion is the loss of structure and function of a portion of the optic nerve due to obstruction of blood flow to the nerve i e ischemia ion is typically classified as either anterior ischemic optic neuropathy or posterior ischemic optic neuropathy according to the part of the optic nerve that is affected people affected will often complain of a loss of visual acuity and a visual field the latter of which is usually in the superior or inferior field when ion occurs in patients below the age of 50 years old other etiologies should be considered such as juvenile diabetes mellitus antiphospholipid antibody associated clotting disorders collagen vascular disease and migraines rarely complications of intraocular surgery or acute blood loss may cause an ischemic event in the optic nerve anterior ion presents with sudden painless visual loss developing over hours to days examination findings usually include decreased visual acuity a visual field defect color vision loss a relative afferent pupillary defect and a swollen optic nerve head posterior ion occurs arteritic nonarteritic and surgical settings it is characterized by acute vision loss without initial disc edema but with subsequent optic disc atrophy although there is no recognized treatment that can reverse the visual loss upon recent reports optic nerve health decompression may be beneficial for a select group of patients with a gradual decline in vision due to ion
ischial bursitis also known as weaver s bottom is inflammation of the synovial bursa located between gluteus maximus muscle and ischial tuberosity it is usually caused by prolonged sitting on a hard surface
ishinagenjo japanese 石投げんじょ stone throwing genjo is a folkloric phenomenon which is documented to occur in the nishisonogi district of the nagasaki prefecture the waters of enoshima and the city of tosu in the saga prefecture in the month of may the rainy season a group of fishermen are working at night in the midst of a thick fog suddenly comes the sound of a huge rock crashing into the ocean a tremendous splash and crack that sends the boat rocking and the sailors panicking however there is no rock to be seen even by the break of day in the japanese folklore institute s book comprehensive lexicon of japanese folklore the phenomenon is explained as being the doing of a sea monster or yōkai japanese 妖怪 variously translated as spectre monster goblin known as the iso woman or some other related sea witch this explanation is echoed in kunio yanagita s book yōkai lectures in which yanagita concurs that the phenomenon is best explained by some oceanic yōkai because of this association many experts have hypothesised that the jo written in hiragana as じょ actually means woman represented by the kanji 女 which is the rendering used by folklorist sakurada katsunori in her paper ghost ships and drowning people written thus ishinagenjo 石投女 translates literally to stone throwing woman the kojien on the other hand renders じょ as 尉 meaning captain or old man the stone throwing old man 石投尉 is likened in the text of the kojien to an old man idly throwing stones into the sea however yōkai expert murakami kenji has expressed doubts regarding the existence of any documentary evidence to visually identify the creature responsible for the phenomenon described indeed the kojien notes that it is assumed that fishermen only imagine seeing a monster but that ultimately the experience as a whole is merely an illusion
anal sex or sodomy in islam is anal intercourse between individuals of the opposite or same sex
island gigantism or insular gigantism is a biological phenomenon in which the size of animals isolated on an island increases dramatically in comparison to their mainland relatives island gigantism is one aspect of the more general island rule which posits that when mainland animals colonize islands small species tend to evolve larger bodies and large species tend to evolve smaller bodies with the arrival of humans and associated predators dogs cats rats pigs many giant as well as other island endemics have become extinct
in stock trading and technical analysis an island reversal is a candlestick pattern with compact trading activity within a range of prices separated from the move preceding it this separation is said to be caused by an exhaustion gap and the subsequent move in the opposite direction occurs as a result of a breakaway gap
an island wake is a geophysical phenomenon which results from the interaction between the island topography and the incoming atmospheric and oceanic flows
in physiology isobaric counterdiffusion icd is the diffusion of different gases into and out of tissues while under a constant ambient pressure and the physiological effects of this phenomenon the term inert gas counterdiffusion is sometimes used as a synonym but can also be applied to situations where the ambient pressure changes it has relevance in mixed gas diving and anesthesiology
isobutyryl coenzyme a dehydrogenase deficiency commonly known as ibd deficiency is a rare metabolic disorder in which the body is unable to process certain amino acids properly people with this disorder have inadequate levels of an enzyme that helps break down the amino acid valine resulting in a build up of valine in the urine a symptom called valinuria
an isochromosome is an unbalanced structural abnormality in which the arms of the chromosome are mirror images of each other the chromosome consists of two copies of either the long q arm or the short p arm because isochromosome formation is equivalent to a simultaneous duplication and deletion of genetic material consequently there is partial trisomy of the genes present in the isochromosome and partial monosomy of the genes in the lost arm
an isodesmic reaction is a chemical reaction in which the type of chemical bonds broken in the reactant are the same as the type of bonds formed in the reaction product this type of reaction is often used as a hypothetical reaction in thermochemistry an example of an isodesmic reaction is ch 3 − ch 3 x → ch 4 ch 2 x − 1 x f cl br i equation 1 describes the deprotonation of a methyl halide by a methyl anion the energy change associated with this exothermic reaction which can be calculated in silico increases going from fluorine to chlorine to bromine and iodine making the ch 2 i − anion the most stable and least basic of all the halides although this reaction is isodesmic the energy change in this example also depends on the difference in bond energy of the c x bond in the base and conjugate acid in other cases the difference may be due to steric strain this difference is small in fluorine but large in iodine in favor of the anion and therefore the energy trend is as described despite the fact that c f bonds are stronger than c i bonds the related term homodesmotic reaction also takes into account orbital hybridization and in addition there is no change in the number of carbon to hydrogen bonds
in nuclear physics and radioactivity isodiaphers refers to nuclides which have different atomic numbers and mass numbers but the same neutron excess which is the difference between numbers of neutrons and protons in the nucleus for example for both 23490 th and 23892 u the difference between the neutron number n and proton number z is n − z 54 one large family of isodiaphers has zero neutron excess n z it contains many primordial isotopes of elements up to calcium it includes ubiquitous 126 c 168 o and 147 n the daughter nuclide of an alpha decay is an isodiapher of the original nucleus similarly beta decays and other weak force involving decays produce isobars
isodicentric 15 also called idic 15 partial tetrasomy 15 q or inverted duplication 15 inv dup 15 is a chromosome abnormality in which a child is born with extra genetic material from chromosome 15 people with idic 15 are typically born with 47 chromosomes in their body cells instead of the normal 46 the extra chromosome is made up of a piece of chromosome 15 that has been duplicated end to end like a mirror image it is the presence of this extra genetic material that is thought to account for the symptoms seen in some people with idic 15 individuals with idic 15 have a total of four copies of this chromosome 15 region instead of the usual two copies 1 copy each on the maternal and paternal chromosomes the syndrome is also often referred to as chromosome 15 q 11 2 13 1 duplication syndrome shortened to dup 15 q a name that is supported and actively promoted by the us based support organization dup 15 q alliance the extra chromosome is occasionally found in the mosaic state i e some of the cells carry the marker chromosome however mostly because of the marker s instability and tendency to be lost during cell division mitosis some cells are completely normal with 46 chromosomes occasionally cells may have more than one idic 15 resulting in 48 or 49 chromosomes in all or some of their cells a similar clinical picture albeit to a milder degree could be expected in individuals that have the extra chromosome 15 material as an interstitial duplication when the extra piece of chromosome 15 is included within the long arm of one of the two copies of chromosome 15 rather than as a small extra marker chromosome often abbreviated to int dup 15 the individual thus having 46 chromosomes
the isohydric principle is the phenomenon whereby multiple acid base pairs in solution will be in equilibrium with one another tied together by their common reagent the hydrogen ion and hence the ph of solution that is when several buffers are present together in the same solution they are all exposed to the same hydrogen ion activity hence the pk of each buffer will dictate the ratio of the concentrations of its base and weak acid forms at the given ph in accordance with the henderson hasselbalch equation any condition that changes the balance of one of the buffer systems also changes the balance of all the others because the buffer systems actually buffer one another by shifting hydrogen ions back and forth from one to the other the isohydric principle has special relevance to in vivo biochemistry where multiple acid base pairs are in solution
isolated congenital asplenia icas is a rare disease in humans that can cause life threatening bacterial infections in children due to primary immunodeficiency the infections can include pneumococal sepsis and meningitis icas is a ribosomopathy due to autosomal dominant mutation of the rpsa gene on chromosome 3 p 21 unlike heterotaxy syndrome the absent spleen is not associated with other structural developmental defects
isolated hypogonadotropic hypogonadism ihh also called idiopathic or congenital hypogonadotropic hypogonadism chh as well as isolated or congenital gonadotropin releasing hormone deficiency igd is a condition that results in a small subset of cases of hypogonadotropic hypogonadism hh due to deficiency in or insensitivity to gonadotropin releasing hormone gnrh where the function and anatomy of the anterior pituitary is otherwise normal and secondary causes of hh are not present it presents as hypogonadism e g reduced or absent puberty ref 1 low libido infertility etc due to an impaired release of the gonadotropins follicle stimulating hormone fsh and luteinizing hormone lh and a resultant lack of sex steroid and peptides production by the gonads ref 2 and ref 3 in addition anosmia loss of the sense of smell occurs in instances of ihh that are the result of kallmann syndrome which is responsible for approximately 50 of all cases of the condition other causes of ihh include gnrh insensitivity which is the second most common cause of ihh and is thought to be responsible for up to 20 of cases and a minority less than 5 10 due to inactivating mutations in a variety of other genes which positively regulate gnrh secretion such as chd 7 kiss 1 r and tacr 3 the causes of approximately 25 of all cases of ihh are still unknown
isolated primary immunoglobulin m deficiency or selective igm immunodeficiency sigmd is a poorly defined dysgammaglobulinemia characterized by decreased levels of igm while levels of other immunoglobulins are normal the immunodeficiency has been associated with some clinical disorders including recurrent infections atopy bloom s syndrome celiac disease systemic lupus erythematosus and malignancy but surprisingly sigmd seems to also occur in asymptomatic individuals high incidences of recurrent upper respiratory tract infections 77 asthma 47 and allergic rhinitis 36 have also been reported sigmd seems to be a particularly rare antibody deficiency with a reported prevalence between 0 03 general population and 0 1 hospitalized patients the etiology of selective igm deficiency remains unclear although various mechanisms have been proposed such as an increase in regulatory t cell functions defective t helper cell functions and impaired terminal differentiation of b lymphocytes into igm secreting cells among others it is however puzzling that class switching seems to happen normally serum levels of other antibodies are normal while dysfunctioning of igm synthesis is expected to occur together with abnormalities in other immunoglobulins notwithstanding a clear pathogenesis and commonly accepted definition a cutoff for sigmd could be the lower limit of the serum igm reference range such as 43 mg dl in adults or even 20 mg dl
in differential geometry an isoparametric function is a function on a riemannian manifold whose level surfaces are parallel and of constant mean curvatures they were introduced by cartan
isosporiasis is a human intestinal disease caused by the parasite isospora belli it is found worldwide especially in tropical and subtropical areas infection often occurs in immuno compromised individuals notably aids patients and outbreaks have been reported in institutionalized groups in the united states the first documented case was in 1915 it is usually spread indirectly normally through contaminated food or water cdc gov
isotonic hyponatremia is a form of hyponatremia with mosm measured between 280 and 295 it can be associated with pseudohyponatremia or with isotonic infusion of glucose or mannitol
isovaleric acidemia also called isovaleric aciduria or isovaleric acid coa dehydrogenase deficiency is a rare autosomal recessive metabolic disorder which disrupts or prevents normal metabolism of the branched chain amino acid leucine it is a classical type of organic acidemia
isthmicoma also known as infundibuloma and tumor of the follicular infundibulum are a cutaneous condition characterized by flat keratotic papules of the head and neck skin lesions that are usually solitary
the italian renaissance italian rinascimento rinaʃʃiˈmento was the earliest manifestation of the general european renaissance a period of great cultural change and achievement that began in italy during the 14 th century and lasted until the 16 th century marking the transition between medieval and early modern europe the term renaissance is in essence a modern one that came into currency in the 19 th century in the work of historians such as jules michelet and jacob burckhardt although the origins of a movement that was confined largely to the literate culture of intellectual endeavor and patronage can be traced to the earlier part of the 14 th century many aspects of italian culture and society remained largely medieval the renaissance did not come into full swing until the end of the century the french word renaissance rinascimento in italian means rebirth and the era is best known for the renewed interest in the culture of classical antiquity after the period that renaissance humanists labeled the dark ages though today perhaps best known for italian renaissance art and architecture the period saw major achievements in literature music philosophy and other arts as well as science italy became the recognized european leader in all these areas by the late 15 th century and to varying degrees retained this lead until about 1600 this was despite a turbulent and generally disastrous period in italian politics in the course of which most of italy was carved up by the major european powers the european renaissance began in tuscany central italy and centred in the city of florence it later spread to venice where the remains of ancient greek culture were brought together providing humanist scholars with new texts the renaissance later had a significant effect on rome which was ornamented with some structures in the new all antico mode then was largely rebuilt by humanist sixteenth century popes the italian renaissance peaked in the mid 16 th century as foreign invasions plunged the region into the turmoil of the italian wars however the ideas and ideals of the renaissance endured and spread into the rest of europe setting off the northern renaissance and the english renaissance the italian renaissance is best known for its cultural achievements accounts of renaissance literature usually begin with petrarch best known for the elegantly polished vernacular sonnet sequence of the canzoniere and for the craze for book collecting that he initiated and his friend and contemporary boccaccio author of the decameron famous vernacular poets of the 15 th century include the renaissance epic authors luigi pulci author of morgante matteo maria boiardo orlando innamorato and ludovico ariosto orlando furioso 15 th century writers such as the poet poliziano and the platonist philosopher marsilio ficino made extensive translations from both latin and greek in the early 16 th century castiglione the book of the courtier laid out his vision of the ideal gentleman and lady while machiavelli cast a jaundiced eye on la verità effettuale della cosa — the actual truth of things — in the prince composed in humanistic style chiefly of parallel ancient and modern examples of virtù italian renaissance painting exercised a dominant influence on subsequent european painting see western painting for centuries afterwards with artists such as giotto di bondone masaccio fra angelico piero della francesca domenico ghirlandaio perugino michelangelo raphael botticelli leonardo da vinci and titian the same is true for architecture as practiced by brunelleschi leon battista alberti andrea palladio and bramante their works include florence cathedral st peter s basilica in rome and the tempio malatestiano in rimini to name only a few not to mention many splendid private residences see renaissance architecture finally the aldine press founded by the printer aldo manuzio active in venice developed italic type and the small relatively portable and inexpensive printed book that could be carried in one s pocket as well as being the first to publish editions of books in ancient greek yet cultural contributions notwithstanding some present day historians also see the era as one of the beginning of economic regression for italy there were some economic downturns due to the opening up of the atlantic trade routes and repeated foreign invasions and interference by both france and the spanish empire
the italian city states were a political phenomenon of small independent states mostly in the central and northern italian peninsula between the 9 th and 15 th centuries after the fall of the western roman empire urban settlements in italy generally enjoyed a greater continuity than in the rest of western europe many of these towns were survivors of earlier etruscan umbrian and roman towns which had existed within the roman empire the republican institutions of rome had also survived some feudal lords existed with a servile labour force and huge tracts of land but by the 11 th century many cities including venice milan florence genoa pisa lucca cremona siena perugia spoleto todi terni and many others had become large trading metropoles able to obtain independence from their formal sovereigns
itch also known as pruritus is a sensation that causes the desire or reflex to scratch itch has resisted many attempts to classify it as any one type of sensory experience modern science has shown that itch has many similarities to pain and while both are unpleasant sensory experiences their behavioral response patterns are different pain creates a withdrawal reflex whereas itch leads to a scratch reflex unmyelinated nerve fibers for itch and pain both originate in the skin however information for them is conveyed centrally in two distinct systems that both use the same nerve bundle and spinothalamic tract
itchy red bump disease also known as papular dermatitis is a cutaneous condition characterized by a red rash that may be treated with puva therapy
in object oriented programming the iterator pattern is a design pattern in which an iterator is used to traverse a container and access the container s elements the iterator pattern decouples algorithms from containers in some cases algorithms are necessarily container specific and thus cannot be decoupled for example the hypothetical algorithm searchforelement can be implemented generally using a specified type of iterator rather than implementing it as a container specific algorithm this allows searchforelement to be used on any container that supports the required type of iterator
the ivanov reaction is the chemical reaction of the dianions endiolates of aryl acetic acids ivanov reagents with electrophiles primarily carbonyl compounds or isocyanates the reaction was named after the bulgarian organic chemist academician dimitar ivanov who discovered it the ivanov reaction ivanov reagents dianions of aryl acetic acids react with many electrophiles including aldehydes ketones isocyanates and alkyl halides the product does not usually spontaneously decarboxylate but it is possible with some reagents the ivanov reaction is known to proceed through the zimmerman traxler model transition state toulec et al have investigated the reaction rates and kinetics
jh is a cryptographic hash function submitted to the nist hash function competition by hongjun wu though chosen as one of the five finalists of the competition jh ultimately lost to nist hash candidate keccak jh has a 1024 bit state and works on 512 bit input blocks processing an input block consists of three steps 1 xor the input block into the left half of the state 2 apply a 42 round unkeyed permutation encryption function to the state this consists of 42 repetitions of 3 1 break the input into 256 4 bit blocks and map each through one of two 4 bit s boxes the choice being made by a 256 bit round dependent key schedule equivalently combine each input block with a key bit and map the result through a 5 → 4 bit s box 4 2 mix adjacent 4 bit blocks using a maximum distance separable code over gf 24 5 3 permute 4 bit blocks so that they will be adjacent to different blocks in following rounds 6 xor the input block into the right half of the state the resulting digest is the first 224 256 384 or 512 bits from the 1024 bit final value it is well suited to a bit slicing implementation using the sse 2 instruction set giving speeds of 16 8 cycles per byte
jsp model 2 is a complex design pattern used in the design of java web applications which separates the display of content from the logic used to obtain and manipulate the content since model 2 drives a separation between logic and display it is usually associated with the model – view – controller mvc paradigm while the exact form of the mvc model was never specified by the model 2 design a number of publications recommend a formalized layer to contain mvc model code the java blueprints for example originally recommended using ejbs to encapsulate the mvc model in a model 2 application requests from the client browser are passed to the controller the controller performs any logic necessary to obtain the correct content for display it then places the content in the request commonly in the form of a javabean or pojo and decides which view it will pass the request to the view then renders the content passed by the controller model 2 is recommended for medium and large sized applications
jaagsiekte is a chronic and contagious disease of the lungs in sheep and goats first described in 1865 its name derives from afrikaans and means chasing sickness such that animals afflicted with the disease are in respiratory distress as if they are out of breath from being chased it is also referred to as ovine pulmonary adenocarcinoma opa during end stage disease animals exude a foamy white fluid from the nose which is thought to be the mode of transmission between animals dissected lungs from afflicted sheep are interspersed with multifocal tumors some of these are small discrete nodules and others will involve the entire half of a lung lobule the disease is caused by a retrovirus called the jaagsiekte sheep retrovirus jsrv that acutely transforms the lung epithelia into cancerous cells specifically type 2 pneumocytes and club cells of the lung are the likely target for jsrv transformation the tumors formed there exhibit the overactive secretory functions which are a hallmark of opa opa is an infectious disease of sheep and recently has been used as an animal model for human lung cancer it is common in the uk and in south africa the disease has a long incubation period and is not seen until sheep reach at least 2 years of age clinical symptoms include weight loss loss of appetite and respiratory difficulty which is associated with obvious movement of the abdomen and high pitched noises fluid accumulates in the respiratory tract and the disease ultimately causes death the retroviral antigen levels of jsrv are very high in opa tumors and can be detected in the lung secretions of infected sheep a common field assessment for jaagsiekte is the wheelbarrow test where one lifts the hind legs of the animal above the head to observe lung exudate flow out the nose and mouth this fluid contains infectious jsrv it is thought that infected animals secrete the virus before showing clinical symptoms and the virus is therefore easily spread within flocks the disease is histologically similar to human bronchioalveolar carcinoma which accounts for approximately 25 of all diagnosed human lung cancers dolly the sheep the first mammal successfully cloned from an adult somatic cell was euthanized after it was confirmed that she had jaagsiekte
jaccoud arthropathy ja jaccoud deformity or jaccoud s arthopathy is a chronic non erosive reversible joint disorder that may occur after repeated bouts of arthritis it is caused by inflammation of the joint capsule and subsequent fibrotic retraction causing ulnar deviation of the fingers through metacarpophalageal joint mcp subluxation primarily of the ring and little finger joints in the feet knees and shoulders may also get affected it is commonly associated with systemic lupus erythematosus sle and occurs in roughly 5 of all cases when associated with rheumatic fever it is also called chronic post – rf arthropathy originally thought to be associated only with rheumatic fever it has since been shown to occur also in sle sjögren syndrome scleroderma dermatomyositis psoriatic arthritis vasculitis ankylosing spondylitis mixed connective tissue disease and pyrophosphate deposition disease it is distinct from bone erosion which is commonly associated with rheumatic arthritis and also distinct from mild deforming arthropathy which is associated with sle there have also been cases of non rheumatic ja associated with lyme disease hiv infection and a number of other conditions treatment focuses toward alleviating pain and in maintaining functionality of the affected joints through use of nonsteroidal anti inflammatory drugs corticosteroids antimalarial drugs and physiotherapy surgery is also a possibility with osteotomy or stabilization with kirschner intramedullary wire tendon relocation however has been shown to only work in 30 of cases the condition is named after the french 19 th century physician sigismond jaccoud
jackson – weiss syndrome jws is a genetic disorder characterized by foot abnormalities and the premature fusion of certain bones of the skull craniosynostosis which prevents further growth of the skull and affects the shape of the head and face it can also sometimes cause intellectual disability and crossed eyes as well it was characterized in 1976
in mathematics the jacobian conjecture is a celebrated problem on polynomials in several variables it was first posed in 1939 by ott heinrich keller it was widely publicized by shreeram abhyankar as an example of a question in the area of algebraic geometry that requires little beyond a knowledge of calculus to state the jacobian conjecture is notorious for the large number of attempted proofs that turned out to contain subtle errors as of 2016 there are no plausible claims to have proved it even the two variable case has resisted all efforts there are no known compelling reasons for believing it to be true and according to there are some suspicions that the conjecture is in fact false for large numbers of variables the jacobian conjecture is number 16 in stephen smale s 1998 list of mathematical problems for the next century
the jacobsen epoxidation sometimes also referred to as jacobsen katsuki epoxidation is a chemical reaction which allows enantioselective epoxidation of unfunctionalized alkyl and aryl substituted olefins it is complementary to the sharpless epoxidation used to form epoxides from the double bond in allylic alcohols the jacobsen epoxidation gains its stereoselectivity from a c 2 symmetric manganese iii salen like ligand which is used in catalytic amounts the manganese atom transfers an oxygen atom from chlorine bleach or similar oxidant the reaction is named after its inventor eric jacobsen and sometimes also including tsutomu katsuki chiral directing catalysts are useful to organic chemists trying to control the stereochemistry of biologically active compounds and develop enantiopure drugs several improved procedures have been developed a general reaction scheme follows
the jacobsen rearrangement is a chemical reaction commonly described as the migration of an alkyl group in a sulfonic acid derived from a polyalkyl or polyhalobenzene jacobsen rearrangement the exact reaction mechanism is not completely clear but evidence indicates that the rearrangement occurs intermolecularly and that the migrating group is transferred to a polyalkylbenzene not to the sulfonic acid sulfonation only takes place after migration the intermolecular mechanism is partially illustrated by the side products found in the following example jacobsen rearrangement furthermore the reaction is limited to benzene rings with at least four substituents alkyl and or halogen groups the sulfo group is easily removed so the jacobsen rearrangement can also be considered as a rearrangement of polyalkylbenzenes it was herzig who described this type of rearrangement for the first time in 1881 using polyhalogenated benzenesulfonic acids but the reaction took the name of the german chemist oscar jacobsen who described the rearrangement of polyalkylbenzene derivatives in 1886
jacobsen syndrome also known as 11 q deletion disorder is a rare congenital disorder resulting from deletion of a terminal region of chromosome 11 that includes band 11 q 24 1 it can cause intellectual disabilities a distinctive facial appearance and a variety of physical problems including heart defects and a bleeding disorder the syndrome was first identified by danish physician petra jacobsen and is believed to occur in approximately 1 out of every 100 000 births
in abstract algebra jacobson s conjecture is an open problem in ring theory concerning the intersection of powers of the jacobson radical of a noetherian ring it has only been proven for special types of noetherian rings so far examples exist to show that the conjecture can fail when the ring is not noetherian on a side so it is absolutely necessary for the ring to be two sided noetherian the conjecture is named for the algebraist nathan jacobson who posed the first version of the conjecture
jaffe – campanacci syndrome is one of the disorders associated with café au lait macules calms presentations may include intellectual disability disseminated non ossifying fibromas of the long bones and jaw hypogonadism or cryptorchidism or giant cell granulomas of the jaw it was characterized in 1958 and 1983
jalili syndrome is a genetic disorder characterized by the combination of cone rod dystrophy of the retina and amelogenesis imperfecta it was characterized in 1988 by dr i k jalili and dr n j d smith following the examination of 29 members of an inbred arab family living within the gaza strip
jamaican vomiting sickness is an acute illness caused by the toxin hypoglycin a which is present in unripened fruit of the ackee tree hypoglycin a is present in the unripe arilli at levels of over 1000 ppm which falls to less than 0 1 ppm in the fully ripened arilli hypoglycin b found only in the inedible seed is believed to be a derivative of hypoglycin a its concentration rises from 0 4 mg g to 3 3 mg g as the fruit ripens
in psychology jamais vu ˈʒæmeɪ ˈvuː french pronunciation ​ ʒa mɛ vy from french meaning never seen is the phenomenon of experiencing a situation that one recognizes in some fashion but that nonetheless seems very unfamiliar often described as the opposite of déjà vu jamais vu involves a sense of eeriness and the observer s impression of seeing the situation for the first time despite rationally knowing that he or she has been in the situation before jamais vu is sometimes associated with certain types of aphasia amnesia and epilepsy jamais vu is most commonly experienced when a person momentarily does not recognise a word or less commonly a person or place that she or he knows this can be achieved by anyone by repeatedly writing or saying a specific word out loud after a few seconds one will often despite knowing that it is a real word feel as if there s no way it is an actual word the phenomenon is often grouped with déjà vu and presque vu or tip of the tongue theoretically as seen below a jamais vu feeling in a sufferer of a delirious disorder or intoxication could result in a delirious explanation of it such as in capgras delusion in which the patient takes a person known by him or her for a false double or impostor if the impostor is himself the clinical setting would be the same as the one described as depersonalisation hence jamais vus of oneself or of the very reality of reality are termed depersonalization and derealization respectively a study by chris moulin of leeds university asked 92 volunteers to write out door 30 times in 60 seconds in july 2006 at the 4 th international conference on memory in sydney he reported that 68 percent of volunteers showed symptoms of jamais vu such as beginning to doubt that door was a real word dr moulin believes that a similar brain fatigue underlies a phenomenon observed in some schizophrenia patients that a familiar person has been replaced by an impostor dr moulin suggests they could be suffering from chronic jamais vu jamais vu can be caused by epileptic seizures
the term jammed finger refers to finger joint pain and swelling from an impact injury this injury tends to be very painful and immediate treatment will usually help heal the joint faster most jammed fingers heal relatively quickly if no fracture occurs if there is a fracture however the healing process will take longer anywhere from one or two weeks to several months and the methods of healing will become more in depth toes can become jammed as well but not as often as fingers
the jammu kashmir liberation front yasin malik is a break away faction of the jammu kashmir liberation front led by yasin malik it is a separatist movement demanding a united kashmir independent from both pakistan and india although previously a militant organization since 1995 it has renounced all violence and called for strictly peaceful methods to achieve its aims however it has questionable support even in kashmir valley and has never contested any democratic elections it has on several occasions been accused of stirring up anti india and anti indian army agitations including several violent stone pelting incidents
janeway lesions are non tender small erythematous or haemorrhagic macular or nodular lesions on the palms or soles only a few millimeters in diameter that are indicative of infective endocarditis pathologically the lesion is described to be a microabscess of the dermis with marked necrosis and inflammatory infiltrate not involving the epidermis they are caused by septic emboli which deposit bacteria forming microabscesses janeway lesions are distal flat ecchymotic and painless osler s nodes and janeway lesions are similar but osler s nodes present with tenderness and are of immunologic origin
jansen s metaphyseal chondrodysplasia or jmc is a disease that results from ligand independent activation of the type 1 of the parathyroid hormone receptor pthr 1 due to one of three reported mutations activating mutation jmc is extremely rare and as of 2007 there are fewer than 20 reported cases worldwide
jansky – bielschowsky disease is an extremely rare autosomal recessive genetic disorder that is part of the neuronal ceroid lipofuscinosis ncl family of neurodegenerative disorders it is caused by the accumulation of lipopigments in the body due to a deficiency in tripeptidyl peptidase i as a result of a mutation in the tpp 1 gene symptoms appear between ages 2 and 4 and consist of typical neurodegenerative complications loss of muscle function ataxia drug resistant seizures epilepsy apraxia development of muscle twitches myoclonus and vision impairment this late infantile form of the disease progresses rapidly once symptoms are onset and ends in death between age 8 and teens the prevalence of jansky – bielschowsky disease is unknown however ncl collectively affects an estimated 1 in 100 00 individuals worldwide jansky – bielschowsky disease is also known as late infantile batten disease lincl or neuronal ceroid lipofuscinosis
janus kinase 3 deficiency or jak 3 deficiency is a defect in the body s cytokine receptors and their signaling jak 3 encodes janus kinase 3 a tyrosine kinase that belongs to the janus family jak 3 functions in signal transduction and interacts with members of the stat signal transduction and activators of transcription family the cause of jak 3 deficiency the deficiency causes the near absence of t lymphocytes and natural killer cells and normal or elevated b lymphocytes due to an autosomal recessive variant of severe combined immunodeficiency scid
japan foreign marriage is a phenomenon occurring in rural japan in recent years rural japanese men have begun taking foreign brides as a way of countering the reduced number of women who are of marriageable childbearing age that are willing to marry rural japanese men the phenomenon has created a new industry of foreign marriage brokering that uses both local governments and private organizations to facilitate the immigration of foreign brides this is largely a result of an aging population in japan where approximately 20 of the population is over the age of 65 which is exceptionally high a fertility rate of only 1 3 and increased opportunities for women and increased costs in child care
in japanese mahjong yaku japanese 役 is a condition that determines the value of the player s hand it is essential to know the yaku for game strategy although the knowledge is not mandatory a player must have a minimum of one yaku in their hand in order to legally win a hand each yaku has a specific han value yaku conditions may be combined to produce hands of greater value the game also features dora that allow a hand to add han value but that cannot count as yaku altogether a hand s points value increases exponentially with every han a hand contains
japanese encephalitis je formerly known as japanese b encephalitis to distinguish it from economo s a encephalitis — is a disease caused by the mosquito borne japanese encephalitis virus jev the japanese encephalitis virus jev itself is a virus from the family flaviviridae part of the japanese encephalitis serocomplex of 9 genetically and antigenically related viruses some which are particularly severe in horses and four known to infect humans including west nile virus domestic pigs and wild birds especially herons are reservoirs of the virus transmission to humans may cause severe symptoms amongst the most important vectors of this disease are the mosquitoes culex tritaeniorhynchus and culex vishnui this disease is most prevalent in southeast asia and east asia
japanese oak wilt also called mortality of oak trees in japan is a fungal disease caused by raffaelea quercivora fungus affecting by oak trees in 1998 japanese plant pathologists group was isolation inoculation and reisolation the dead tree it s the first disease known that raffaela fungus cause plant disease
japanese spotted fever or oriental spotted fever is a condition characterized by a rash that has early macules and later in some patients petechiae it is caused by rickettsia japonica
the japp – klingemann reaction is a chemical reaction used to synthesize hydrazones from β keto acids or β keto esters and aryl diazonium salts the reaction is named after the chemists francis robert japp and felix klingemann the japp klingemann reaction the hydrazone products of the japp – klingemann reaction are most often used as intermediates in syntheses of more complex organic molecules for example a phenylhydrazone product can be heated in the presence of strong acid to produce an indole via the fischer indole synthesis the japp klingemann reaction used to synthesize indoles
the japp – maitland condensation is an organic reaction and a type of aldol reaction and a tandem reaction in a reaction between the ketone 2 pentanone and the aldehyde benzaldehyde catalyzed by base the bis aldol adduct is formed first the second step is a ring closing reaction when one hydroxyl group displaces the other in a nucleophilic substitution forming an oxo tetrahydropyran japp maitland condensation the reaction was first described by francis robert japp and william maitland in 1904 the japp – maitland reaction is of some importance to synthetic organic chemistry for example as part of the synthesis of biomolecule centrolobine japp – maitland condensation in centrolobine synthesis
jargon aphasia is a type of fluent aphasia in which an individual s speech is incomprehensible but appears to make sense to the individual persons experiencing this condition will either replace a desired word with another that sounds or looks like the original one or has some other connection to it or they will replace it with random sounds accordingly persons with jargon aphasia often use neologisms and may perseverate if they try to replace the words they can t find with sounds
the jarisch – herxheimer reaction is a reaction to endotoxin like products released by the death of harmful microorganisms within the body during antibiotic treatment
jaundice also known as icterus is a yellowish or greenish pigmentation of the skin and whites of the eyes due to high bilirubin levels it is commonly associated with itchiness the feces may be pale and the urine dark jaundice in babies occurs in over half in the first week following birth and in most is not a problem if bilirubin levels in babies are very high for too long a type of brain damage known as kernicterus may occur causes of jaundice vary from non serious to potentially fatal levels of bilirubin in blood are normally below 1 0 mg dl 17 µmol l and levels over 2 3 mg dl 34 51 µmol l typically results in jaundice high bilirubin is divided into two types unconjugated indirect and conjugated direct conjugated bilirubin can be confirmed by finding bilirubin in the urine other conditions that can cause yellowish skin but are not jaundice include carotenemia from eating large amounts of certain foods and medications like rifampin high unconjugated bilirubin may be due to excess red blood cell breakdown large bruises genetic conditions such as gilbert s syndrome no eating for a prolonged period of time newborn jaundice or thyroid problems high conjugated bilirubin may be due to liver diseases such as cirrhosis or hepatitis infections medications or blockage of the bile duct in the developed world the cause is more often blockage of the bile duct or medications while in the developing world it is more often infections such as viral hepatitis leptospirosis schistosomiasis or malaria blockage of the bile duct may occur due to gallstones cancer or pancreatitis medical imaging such as ultrasound is useful for detecting bile duct blockage treatment of jaundice is typically determined by the underlying cause if a bile duct blockage is present surgery is typically required otherwise management is medical medical management may involve treating infectious causes and stopping medication that could be contributing among newborns depending on age and prematurity a bilirubin greater than 4 21 mg dl 68 360 µmol l may be treated with phototherapy or exchanged transfusion the itchiness may be helped by draining the gallbladder or ursodeoxycholic acid the word jaundice is from the french jaunisse meaning yellow disease
a jaw abnormality is disorder in the formation or shape of the jaw it can involve malocclusion types include micrognathism prognathism retrognathism pierre robin syndrome
jaw claudication is pain in the jaw associated with chewing it is a classic symptom of giant cell arteritis but can be confused with symptoms of temporomandibular joint disease rheumatoid arthritis of the temporomandibular joint myasthenia gravis tumors of the parotid gland or occlusion or stenosis of the external carotid artery the term is derived by analogy from claudication of the leg where pain is caused by arterial insufficiency
jeavons syndrome is a type of epilepsy it is one of the most distinctive reflex syndromes of idiopathic generalized epilepsy characterized by the triad of eyelid myoclonia with and without absences eye closure induced seizures eeg paroxysms or both and photosensitivity eyelid myoclonia with or without absences is a form of epileptic seizure manifesting with myoclonic jerks of the eyelids with or without a brief absence these are mainly precipitated by closing of the eyes and lights eyelid myoclonia is the defining seizure type of jeavons syndrome
the jeep problem desert crossing problem or exploration problem is a mathematics problem in which a jeep must maximise the distance it can travel into a desert with a given quantity of fuel the jeep can only carry a fixed and limited amount of fuel but it can leave fuel and collect fuel at fuel dumps anywhere in the desert the problem was solved by n j fine in 1947
a jefferson fracture is a bone fracture of the anterior and posterior arches of the c 1 vertebra though it may also appear as a three or two part fracture the fracture may result from an axial load on the back of the head or hyperextension of the neck e g caused by diving causing a posterior break and may be accompanied by a break in other parts of the cervical spine it is named after the british neurologist and neurosurgeon sir geoffrey jefferson who reported four cases of the fracture in 1920 in addition to reviewing cases that had been reported previously
jeffrey p nadler born 27 february 1950 in brooklyn new york is a jewish american infectious diseases and hiv aids expert his most recent position has been as acting director and assistant director of the therapeutics research program division of aids daids national institute of allergy and infectious diseases niaid where he oversaw nih niaid sponsored national and international hiv aids research he is well known for his service as an expert hiv consultant to the association of physicians of india api as a facilitator to the creation of the first guidelines for use of antiretroviral therapy in india and for training countless indian physicians in the treatment of hiv aids through the ngo chart india his reputation as physician adventurer is also of note he treated climbers while ascending mount everest sailors while racing around the world and indigenous peoples while backpacking along the amazon river in brazil and while hacking his way through the jungles of peru on a mapmaking expedition a master hiv clinician of international repute he has treated patients with hiv and aids in brazil the czech republic hungary india russia and the united states
jejemon tagalog pronunciation ˈdʒɛdʒɛmon is a pop culture phenomenon in the philippines according to urban dictionary a jejemon is a person who has managed to subvert the english language to the point of incomprehensibility the philippine daily inquirer describes jejemons as a new breed of hipster who have sic developed not only their own language and written text but also their own subculture and fashion
jellyfish dermatitis is a cutaneous condition caused by stings from a jellyfish
jembrana disease is an acute viral disease of cattle while it produces relatively mild symptoms in taurine cattle the jembrana virus is particularly severe in bali cattle where it has a fatality rate of approximately seventeen percent its first documented outbreak occurred in 1964 in the jembrana district of bali indonesia within two years of its appearance the disease had killed an estimated 26 000 of the approximately 300 000 cattle on bali island the virus belongs to the lentivirus genus which include immunodeficiency viruses such as hiv instead of the chronic disease produced by most lentivruses jembrana disease produces acute effects after an incubation period of 5 – 12 days the disease produces symptoms including inappetence fever lethargy enlargement of the lymph nodes and diarrhoea there is at least one strain that has been sequenced
the jersey finger is a finger related tendon injury that is common in athletics and can result in permanent loss of flexion of the end of the finger if not surgically repaired this injury often occurs in american football when a player grabs another player s jersey with the tips of one or more fingers while that player is pulling or running away
jervell and lange nielsen syndrome jlns is a type of long qt syndrome associated with severe bilateral sensorineural hearing loss long qt syndrome causes the cardiac muscle to take longer than usual to recharge between beats if untreated the irregular heartbeats called arrhythmias can lead to fainting seizures or sudden death it was first described by anton jervell and fred lange nielsen in 1957
jesse roth md born august 5 1934 is a diabetes and diabetes related researcher at the feinstein institute for medical research he received his ba in 1955 from columbia university and his md in 1959 from albert einstein college of medicine he was a recipient of the 1980 gairdner foundation international award and in 1982 he received the american diabetes association s banting medal for scientific achievement
jester s privilege is the ability and right of a jester to talk and mock freely without being punished for nothing he says seems to matter martin luther used jest in many of his criticisms against the catholic church in the introduction to to the christian nobility of the german nation he calls himself a court jester and later in text he explicitly invokes the jester s privilege when saying that monks should break their chastity vows
jet blast is the phenomenon of rapid air movement produced by the jet engines of aircraft particularly on or before takeoff a large jet engined aircraft can produce winds of up to 100 knots 190 km h 120 mph as far away as 60 metres 200 ft behind it at 40 maximum rated power jet blast can be a hazard to people or other unsecured objects behind the aircraft and is capable of flattening buildings and destroying vehicles despite the power and potentially destructive nature of jet blast there are relatively few jet blast incidents due to the invisible nature of jet blast and the aerodynamic properties of light aircraft light aircraft moving about airports are particularly vulnerable pilots of light aircraft frequently stay off to the side of the runway rather than follow in the centre to negate the effect of the blast propeller planes are also capable of generating significant rearwards winds known as prop wash some airports have installed jet blast deflectors in areas where roads or people may be in the path of the jet blast on take off
jet lag medically referred to as desynchronosis and rarely as circadian dysrhythmia is a physiological condition which results from alterations to the body s circadian rhythms resulting from rapid long distance trans meridian east – west or west – east travel on high speed aircraft for example someone travelling from new york to london feels as if the time were five hours earlier than local time jet lag was previously classified as one of the circadian rhythm sleep disorders the condition of jet lag may last several days before the traveller is fully adjusted to the new time zone a recovery period of one day per time zone crossed is a suggested guideline jet lag is especially an issue for airline pilots crew and frequent travellers airlines have regulations aimed at combating pilot fatigue caused by jet lag the term jet lag is used because before the arrival of passenger jet aircraft it was uncommon to travel far and fast enough to cause jet lag travel by propeller driven aircraft by ship or by train were slower and of more limited distance than jet flights and thus did not contribute widely to the problem
in high energy physics jet quenching is a phenomenon that can occur in the collision of ultra high energy particles in general the collision of high energy particles can produce jets of elementary particles that emerge from these collisions collisions of ultra relativistic heavy ion particle beams create a hot and dense medium comparable to the conditions in the early universe and then these jets interact strongly with the medium leading to a marked reduction of their energy this energy reduction is called jet quenching
job control is a person s ability to influence what happens in his or her work environment in particular to influence matters that are relevant to his or her personal goals job control may include control over work tasks control over the work pace and physical movement control over the social and technical environment and freedom from supervision workplace autonomy has been seen as a specialized form of the more general concept of control workplace autonomy is the freedom of a person to determine what he or she does at work and how
job creep is a phenomenon in which employers continually require increasing amounts of work relative to the normal requirements of their operations
job shop scheduling or job shop problem is an optimization problem in computer science and operations research in which ideal jobs are assigned to resources at particular times the most basic version is as follows we are given n jobs j 1 j 2 jn of varying processing times which need to be scheduled on m machines with varying processing power while trying to minimize the makespan the makespan is the total length of the schedule that is when all the jobs have finished processing in most practical settings the problem is presented as an online problem dynamic scheduling that is the decision of scheduling a job can only be made online when the job is presented to the algorithm this problem is one of the best known combinatorial optimization problems and was the first problem for which competitive analysis was presented by graham in 1966 best problem instances for basic model with makespan objective are due to taillard
a jobless recovery or jobless growth is an economic phenomenon in which a macroeconomy experiences growth while maintaining or decreasing its level of employment the term has been coined by the economist nick perna in the early 1990 s
in psychoanalytic analysis the jocasta complex is the incestuous sexual desire of a mother towards her son raymond de saussure introduced the term in 1920 by way of analogy to its logical converse in psychoanalysis the oedipus complex and it may be used to cover different degrees of attachment including domineering but asexual mother love – something perhaps particularly prevalent with an intelligent son and an absent weak father figure
johanson – blizzard syndrome jbs is a rare sometimes fatal autosomal recessive multisystem congenital disorder featuring abnormal development of the pancreas nose and scalp with mental retardation hearing loss and growth failure it is sometimes described as a form of ectodermal dysplasia the disorder is especially noted for causing profound developmental errors and exocrine dysfunction of the pancreas and it is considered to be an inherited pancreatic disease
john templeton bowen 1857 – 1940 was an american dermatologist bowen s disease and bowenoid papulosis are named for him
the johnson – corey – chaykovsky reaction sometimes referred to as the corey – chaykovsky reaction or ccr is a chemical reaction used in organic chemistry for the synthesis of epoxides aziridines and cyclopropanes it was discovered in 1961 by a william johnson and developed significantly by e j corey and michael chaykovsky the reaction involves addition of a sulfur ylide to a ketone aldehyde imine or enone to produce the corresponding 3 membered ring the reaction is diastereoselective favoring trans substitution in the product regardless of the initial stereochemistry the synthesis of epoxides via this method serves as an important retrosynthetic alternative to the traditional epoxidation reactions of olefins johnson – corey – chaykovsky reaction the reaction is most often employed for epoxidation via methylene transfer and to this end has been used in several notable total syntheses see below additionally detailed below are the history mechanism scope and enantioselective variants of the reaction several reviews have been published
johnson – mcmillin syndrome is a neuroectodermal syndrome that consist of conductive hearing loss and microtia
aphalangy hemivertebrae and urogenital intestinal dysgenesis is an extremely rare syndrome described only in three siblings it associates hypoplasia or aplasia of phalanges of hands and feet hemivertebrae and various urogenital and or intestinal abnormalities intrafamilial variability is important as one sister had lethal abnormalities potter sequence and pulmonary hypoplasia while her affected brother was in good health with normal psychomotor development at 6 months of age prognosis seems to depend mainly on the severity of visceral malformations etiology and inheritance remain unknown
a joint is a break fracture of natural origin in the continuity of either a layer or body of rock that lacks any visible or measurable movement parallel to the surface plane of the fracture although they can occur singly they most frequently occur as joint sets and systems a joint set is a family of parallel evenly spaced joints that can be identified through mapping and analysis of the orientations spacing and physical properties a joint system consists of two or more intersecting joint sets the distinction between joints and faults hinges on the terms visible or measurable which depends on the scale of observation faults differ from joints in that they exhibit visible or measurable lateral movement between the opposite surfaces of the fracture as a result a joint may have been created by either strict movement of a rock layer or body perpendicular to the fracture or by varying degrees of lateral displacement parallel to the surface plane of the fracture that remains “ invisible ” at the scale of observation joints are among the most universal geologic structures as they are found in most every exposure of rock they vary greatly in appearance dimensions and arrangement and occur in quite different tectonic environments often the specific origin of the stresses that created certain joints and associated joint sets can be quite ambiguous unclear and sometimes controversial the most prominent joints occur in the most well consolidated lithified and highly competent rocks such as sandstone limestone quartzite and granite joints may be open fractures or filled by various materials joints which are infilled by precipitated minerals are called veins and joints filled by solidified magma are called dikes
a joint dislocation also called luxation occurs when there is an abnormal separation in the joint where two or more bones meet a partial dislocation is referred to as a subluxation dislocations are often caused by sudden trauma on the joint like an impact or fall a joint dislocation can cause damage to the surrounding ligaments tendons muscles and nerves dislocations can occur in any joint major shoulder knees etc or minor toes fingers etc the most common joint dislocation is a shoulder dislocation treatment for joint dislocation is usually by closed reduction that is skilled manipulation to return the bones to their normal position reduction should be done only by trained people because it can cause injury
a joint effusion is the presence of increased intra articular fluid it may affect any joint commonly it involves the knee
joint locking or locked joint is the term used to describe the pain that is caused when the joint is extended beyond a certain angle as a result the patient may be forced to restrict the joint extension from movement limited to just 10 to 30 degrees any further extension beyond the restricted angle can cause severe intractable joint pain limitation in achieving a normal extension can create many challenges for a normal movement joint locking is most commonly caused due to meniscus tear or similar injuries osteoarthritis and congenital defects in a few cases
in microeconomics joint product pricing is the firm s problem of choosing prices for joint products which are two or more products produced from the same process or operation each considered to be of value pricing for joint products is more complex than pricing for a single product to begin with there are two demand curves the characteristics of each could be different demand for one product could be greater than for the other consumers of one product could be more price elastic than consumers of the other and therefore more sensitive to changes in the product s price to complicate things further both products because they are produced jointly share a common marginal cost curve there are also complexities in the production function their production could be linked in the sense that they are bi products referred to as complements in production or in the sense that they can be produced by the same inputs referred to as substitutes in production further production of the joint product could be in fixed proportions or in variable proportions when setting prices in such a complex situation microeconomic marginal analysis is helpful in a simple case of a single product the price is set at that quantity demanded where the marginal cost equals the marginal revenue this is what is done when joint products are produced in variable proportions each product is treated separately it might even be possible to construct separate cost functions in the diagram below to determine optimal pricing for joint products produced in variable proportions one finds the intersection point of marginal revenue product a with the joint marginal cost curve that quantity is then extended up to the demand curve for product a which yields the profit maximizing price for product a point pa in the diagram the same is done for product b yielding price point pb 1 alt textpricing of joint products if the products are produced in fixed proportions e g cow hides and cow steaks then one of the products will likely be produced in quantities different from the profit maximizing amount considered separately in fact the profit maximizing quantity and price of the second half of the joint product will be different from the profit maximizing amount considered separately in the diagram product b is produced in greater amounts than the profit maximizing amount considered separately and sold at a lower price point pb 2 than the profit maximizing price considered separately point pb 1 although the price is lower and the output is higher the marginal cost is also higher yet this is a profit maximizing solution to this situation the quantity of product b supplied is increased to the point where marginal revenue becomes zero i e where the marginal revenue curve intersects the horizontal axis
joint stiffness may be either the symptom of pain on moving a joint the symptom of loss of range of motion or the physical sign of reduced range of motion pain on movement is commonly caused by osteoarthritis often in quite minor degrees and other forms of arthritis it may also be caused by injury or overuse and rarely by more complex causes of pain such as infection or neoplasm the range of motion may be normal or limited by pain morning stiffness pain which eases up after the joint has been used is characteristic of rheumatoid arthritis loss of motion symptom the patient notices that the joint or many joints do not move as far as they used to or need to loss of motion is a feature of more advanced stages of arthritis including osteoarthritis rheumatoid arthritis and ankylosing spondylitis loss of range of motion sign the examining medical professional notes that the range of motion of the joint is less than normal routine examination by an orthopaedic surgeon or rheumatologist will often pay particular attention to this the range of motion may be measured and compared to the other side and to normal ranges this sign is associated with the same causes as the symptom in extreme cases when the joint does not move at all it is said to be ankylosed
a jones fracture is a fracture in the meta diaphyseal junction of the fifth metatarsal of the foot the proximal end of the metatarsal where the jones fracture occurs is near the midportion of the foot on the fifth ray of which the 5 th toe belongs those who sustain a jones fracture have pain over this area swelling and difficulty walking the fracture was first described by orthopedic surgeon sir robert jones who sustained this injury himself while dancing and reported it in the annals of surgery in 1902
the jones oxidation is an organic reaction for the oxidation of primary and secondary alcohols to carboxylic acids and ketones respectively it is named after its discoverer sir ewart jones the jones oxidation jones reagent is a solution of chromium trioxide in dilute sulfuric acid and acetone a mixture of potassium dichromate and dilute sulfuric acid can also be used the solvent acetone markedly affects the properties of the chromic acid the oxidation is very rapid quite exothermic and the yields are typically high the reagent rarely oxidizes unsaturated bonds
the josephson effect is the phenomenon of supercurrent — i e a current that flows indefinitely long without any voltage applied — across a device known as a josephson junction jj which consists of two superconductors coupled by a weak link the weak link can consist of a thin insulating barrier known as a superconductor – insulator – superconductor junction or s i s a short section of non superconducting metal s n s or a physical constriction that weakens the superconductivity at the point of contact s s s the josephson effect is an example of a macroscopic quantum phenomenon it is named after the british physicist brian david josephson who predicted in 1962 the mathematical relationships for the current and voltage across the weak link the dc josephson effect had been seen in experiments prior to 1962 but had been attributed to super shorts or breaches in the insulating barrier leading to the direct conduction of electrons between the superconductors the first paper to claim the discovery of josephson s effect and to make the requisite experimental checks was that of philip anderson and john rowell these authors were awarded patents on the effects that were never enforced but never challenged before josephson s prediction it was only known that normal i e non superconducting electrons can flow through an insulating barrier by means of quantum tunneling josephson was the first to predict the tunneling of superconducting cooper pairs for this work josephson received the nobel prize in physics in 1973 josephson junctions have important applications in quantum mechanical circuits such as squids superconducting qubits and rsfq digital electronics the nist standard for one volt is achieved by an array of 19 000 josephson junctions in series
in computer science and mathematics the josephus problem or josephus permutation is a theoretical problem related to a certain counting out game people are standing in a circle waiting to be executed counting begins at a specified point in the circle and proceeds around the circle in a specified direction after a specified number of people are skipped the next person is executed the procedure is repeated with the remaining people starting with the next person going in the same direction and skipping the same number of people until only one person remains and is freed the problem — given the number of people starting point direction and number to be skipped — is to choose the position in the initial circle to avoid execution
joubert syndrome is a rare genetic disorder that affects the cerebellum an area of the brain that controls balance and coordination
the jovian – plutonian gravitational effect is a hoax phenomenon stated to cause a noticeable short term reduction in gravity on earth that was invented for april fools day by the english astronomer patrick moore and broadcast on bbc radio 2 on 1 april 1976
juan j dominguez march 11 1957 is a personal injury and consumer rights attorney based in los angeles california
in the united states judicial review is the ability of a court to examine and decide if a statute treaty or administrative regulation contradicts or violates the provisions of existing law a state constitution or ultimately the united states constitution while the u s constitution does not explicitly define a power of judicial review the authority for judicial review in the united states has been inferred from the structure provisions and history of the constitution two landmark decisions by the u s supreme court served to confirm the inferred constitutional authority for judicial review in the united states in 1796 hylton v united states was the first case decided by the supreme court involving a direct challenge to the constitutionality of an act of congress the carriage act of 1794 which imposed a carriage tax the court engaged in the process of judicial review by examining the plaintiff s claim that the carriage tax was unconstitutional after review the supreme court decided the carriage act was constitutional in 1803 marbury v madison was the first supreme court case where the court asserted its authority for judicial review to strike down a law as unconstitutional at the end of his opinion in this decision chief justice john marshall maintained that the supreme court s responsibility to overturn unconstitutional legislation was a necessary consequence of their sworn oath of office to uphold the constitution as instructed in article six of the constitution as of 2014 the united states supreme court has held 176 acts of the u s congress unconstitutional
jugular vein ectasia is a venous anomaly that commonly presents itself as a unilateral neck swelling in children and adults it is rare to have bilateral neck swelling due to internal jugular vein ectasia
the julia olefination also known as the julia – lythgoe olefination is the chemical reaction used in organic chemistry of phenyl sulfones 1 with aldehydes or ketones to give alkenes 3 after alcohol functionalization and reductive elimination using sodium amalgam or smi 2 the reaction is named after the french chemist marc julia julia olefination revised scheme the utility of this connective olefination reaction arises from its versatility its wide functional group tolerance and the mild reaction conditions under which the reaction proceeds all four steps can be carried out in a single reaction vessel and use of r 3 x is optional however purification of the sulfone intermediate 2 leads to higher yield and purity most often r 3 is acetyl or benzoyl with acetic anhydride or benzoyl chloride used in the preparation of 2
the july effect sometimes referred to as the july phenomenon is a perceived increase in the risk of medical errors and surgical complications that occurs in association with the time of year in which united states medical school graduates begin residencies a similar period in the united kingdom is known as the killing season
jumble ice is a phenomenon that occurs when ice atop a river or other flowing body of water fractures due to the different flow rates beneath the ice on a lake pond or other stationary body of water ice forms undisturbed and generally does not move as long as the entire surface of the body of water is frozen when a river freezes water flow typically continues beneath the ice exerting pressure on it if the ice fractures pieces of ice torn free by the river s current will collide with stationary or slower moving pieces after becoming stuck in place the loosened pieces of ice refreeze irregularly causing a rough or jumbled surface in general the faster a body of water flows beneath ice the more likely it is to develop jumble ice temperatures near the freezing point also tend to cause jumble ice as the higher temperatures weaken the ice structure allowing for more pieces to be torn free before refreezing the yukon river in alaska often exhibits jumble ice during the winter jumble ice is a hazard for winter travelers as the broken ground formed by the jumble ice can cause snowmachine accidents or injuries to sled dogs
jump rings are usually metal rings used to make chains jewelry and chainmaille they are made by wrapping wire round a mandrel to make a coil and then cutting the coil with wire cutters to make individual rings the rings can be assembled one by one into chains earrings objects such as bowls or ornaments and chain mail clothing the making of items from jump rings is called chain maille maille is french for mesh jump rings can be described by the following qualities
the jumping frenchmen of maine were a group of 19 th century lumberjacks who exhibited a rare disorder of unknown origin the syndrome entails an exaggerated startle reflex which may be described as an uncontrollable jump individuals with this condition can exhibit sudden movements in all parts of the body jumping frenchmen syndrome shares symptoms with other startle disorders individuals with this condition were first found in the northern regions of maine and were first described by george miller beard in 1878
junctional ectopic tachycardia jet is a rare syndrome of the heart that manifests in patients recovering from heart surgery it is characterized by cardiac arrhythmia or irregular beating of the heart caused by abnormal conduction from or through the atrioventricular node av node in newborns and infants up to 6 weeks old the disease may also be referred to as his bundle tachycardia
junctional epidermolysis bullosa is a skin condition characterized by blister formation within the lamina lucida of the basement membrane zone
junctional epidermolysis bullosa jeb is an inherited disorder that is also known as red foot disease or hairless foal syndrome jeb is the result of a genetic mutation that inhibits protein production that is essential for skin adhesion therefore tissues such as skin and mouth epithelia are affected as a result blisters form over the entire body causing pain and discomfort also the open sores leave the newborn foal highly susceptible to secondary infection the condition can be categorized into two types of mutations jeb 1 and jeb 2 jeb 1 is found in belgian draft horses as well as other related draft breeds in contrast jeb 2 is found in american saddlebred horses
junctional tachycardia is a form of supraventricular tachycardia characterized by involvement of the av node it can be contrasted to atrial tachycardia it is a tachycardia associated with the generation of impulses in a focus in the region of the atrioventricular node due to an a v disassociation in general the av junction s intrinsic rate is 40 60 bpm so junctional tachycardia implies a rate 60 bpm
jurosomatic illness is a somatic illness brought on by a pending lawsuit a segment of john stossel s show on lawsuit abuse aired june 14 2012 was devoted to reporting on this illness senator john barrasso r wyo an orthopedic surgeon by education who was interviewed by stossel for the episode stated that this is an illness that he had studied in medical school he described it as a syndrome arising from a legitimate injury and legitimate pain and suffering which drags out for the duration of the lawsuit brought on by the stress and anxiety of the continuing lawsuit as well as anger and fixation on the injury associated with it stossel had also quoted a british psychiatrist theodore dalrymple as saying if you pay people to suffer they will suffer injuries that would be self limiting become permanently crippling the litigant formely healthy rapidly succumbs to every kind of unprovable ailment headache loss of concentration dizziness depression when a man says his whole life has been ruined by some accident i know without having to ask i am in the presence of litigation it turns hypochondriasis into a way of life
a juvenile active ossifying fibroma is a benign fibro osseous neoplasm composed of mixture of stroma and bone characterized by rapid and destructive growth
juvenile cellulitis also known as puppy head gland disease puppy strangles and juvenile pyoderma is a disease of dogs symptoms include dermatitis lethargy depression and lameness when puppies are first presented with what appears to be staphylococcal pyoderma juvenile cellulitis a relatively rare condition may not be considered
juvenile dermatomyositis jdm is an idiopathic inflammatory myopathy imm of presumed autoimmune dysfunction resulting in muscle weakness among other complications it manifests itself in children it is the pediatric counterpart of dermatomyositis in jdm the body s immune system attacks blood vessels throughout the body causing inflammation called vasculitis in the united states the incidence rate of jdms is approximately 2 3 cases per million children per year the uk incidence is believed to be between 2 3 per million children per year with some difference between ethnic groups the sex ratio female male is approximately 2 1 other idiopathic inflammatory myopathies include juvenile polymyositis pm which is rare and not as common in children as in adults
juvenile hemochromatosis or hemochromatosis type 2 is as its name indicates a form of hemochromatosis which emerges during youth there are two forms hfe 2 a is associated with hemojuvelin hfe 2 b is associated with hepcidin antimicrobial peptide some sources only specifically include hemojuvelin as a cause of juvenile hemochromatosis
juvenile idiopathic arthritis jia also known as juvenile rheumatoid arthritis jra is the most common form of arthritis in children and adolescents juvenile in this context refers to an onset before age 16 idiopathic refers to a condition with no defined cause and arthritis is the inflammation of the synovium of a joint jia is an autoimmune non infective inflammatory joint disease of more than 6 weeks duration in children less than 16 years of age the disease commonly occurs in children from the ages of 7 to 12 but it may occur in adolescents as old as 15 years of age as well as in infants it is a subset of arthritis seen in childhood which may be transient and self limited or chronic it differs significantly from arthritis commonly seen in adults osteoarthritis rheumatoid arthritis and other types of arthritis that can present in childhood which are chronic conditions e g psoriatic arthritis and ankylosing spondylitis aetiopathology is similar to rheumatoid arthritis but with less marked cartilage erosion and joint instability and absent rheumatoid factor jia affects approximately 1 in 1 000 children in any given year with about 1 in 10 000 having a more severe form
juvenile megaloblastic anaemia 1 imerslund grasbeck syndrome is a disease caused by selective cobalamin malabsorption and inconstant proteinuria it is caused by mutations in the cubilin cubn or amnionless amn genes
juvenile myelomonocytic leukemia jmml is a serious chronic leukemia cancer of the blood that affects children mostly aged 4 and younger the name jmml now encompasses all diagnoses formerly referred to as juvenile chronic myeloid leukemia jcml chronic myelomonocytic leukemia of infancy and infantile monosomy 7 syndrome the average age of patients at diagnosis is 2 years old the world health organization has included jmml in the category of myelodysplastic and myeloproliferative disorders
juvenile myoclonic epilepsy jme also known as janz syndrome is a fairly common form of idiopathic generalized epilepsy representing 5 10 of all epilepsy cases this disorder typically first manifests itself between the ages of 12 and 18 with brief episodes of involuntary muscle twitching occurring early in the morning most patients also have generalized seizures that affect the entire brain and many also have absence seizures genetic studies have demonstrated at least 6 loci for jme 4 with known causative genes most of these genes are ion channels with the one non ion channel gene having been shown to affect ion channel currents
juvenile plantar dermatosis also known as atopic winter feet dermatitis plantaris sicca forefoot dermatitis moon boot foot syndrome and sweaty sock dermatitis is a condition usually seen in children between the ages of 3 and 14 and involves the cracking and peeling of weight bearing areas of the soles of the feet
juvenile polyposis syndrome is a syndrome characterized by the appearance of multiple juvenile polyps in the gastrointestinal tract polyps are abnormal growths arising from a mucous membrane these usually begin appearing before age 20 but the term juvenile refers to the type of polyp not to the age of the affected person while the majority of the polyps found in juvenile polyposis syndrome are non neoplastic hamartomatous self limiting and benign there is an increased risk of adenocarcinoma solitary juvenile polyps most commonly occur in the rectum and present with rectal bleeding the world health organization criteria for diagnosis of juvenile polyposis syndrome are one of either 1 more than five juvenile polyps in the colon or rectum or 2 juvenile polyps throughout the gastrointestinal tract or 3 any number of juvenile polyps in a person with a family history of juvenile polyposis
juvenile primary lateral sclerosis jpls also known as primary lateral sclerois plsj is a rare genetic disorder with a small number of reported cases characterized by progressive weakness and stiffness of muscles in the arms legs and face the disorder damages motor neurons which are specialized nerve cells in the brain and spinal cord that control muscle movement
juvenile xanthogranuloma is a form of histiocytosis classified as non langerhans cell histiocytosis or more specifically type 2 juvenile xanthogranuloma jxg is a rare dermatological disorder that primarily affects infants under one year of age but can also be found in older children and adults it was first described in 1905 by adamson in 5 to 17 of patients the disorder is present at birth but the median age of onset is two years jxg is a benign idiopathic cutaneous granulomatous tumor and the most common form of non langerhans cell histiocytosis non lhc the lesions appear as orange red macules or papules and are usually located on the face neck and upper trunk they may also appear at the groin scrotum penis clitoris toenail palms soles lips lungs bone heart and gastrointestinal tract more rarely jxg usually manifests with multiple lesions on the head and neck in cases with children under six months of age the condition usually resolves spontaneously over one to five years a biopsy of the lesion is critical to confirm the diagnosis ocular jxg manifests in up to 10 of people with jxg and may affect their vision the presence of jxg in the eye can cause spontaneous hyphema secondary glaucoma or even blindness it is most often seen in the iris but may be found on the eyelid corneoscleral limbus conjunctiva orbit retina choroid disc or optic nerve of patients with ocular jxg 92 are younger than the age of two although cutaneous jxg usually disappear spontaneously ocular lesions rarely improve spontaneously and require treatment treatments that have been used include surgical excision intralesional steroid injection cryotherapy and low dose radiotherapy in the case of a resistant or reoccurring lesion chemotherapy has been used as a treatment ocular jxg is usually unilateral and presents with a tumor a red eye with signs of uveitis unilateral glaucoma spontaneous hyphema or heterochromia iridis diagnosing and treating the patient as early as possible contributes to the most positive visual outcome histiocytic disorders like jxg are identified by the cells that make them up immunohistochemical analysis is used to discern the immunoreactivity to certain antibodies in these analyses jxg is a non lhc disorder which is a varied group of disorders defined by the accumulation of histiocytes that do not meet criteria to be diagnosed as langerhans cells jxg is not metastatic and may be present with lipid deposits jxg is often accompanied with other disorders such as neurofibromatosis type one and juvenile chronic myelogenous leukemia juvenile variety xantogranuloma can be distinguished from xanthoma by the spread of the lesion and the lack of lipid abnormalities other similar diagnoses include molluscum contagiosum hemangioma and neurofibroma
the k server problem is a problem of theoretical computer science in the category of online algorithms one of two abstract problems on metric spaces that are central to the theory of competitive analysis the other being metrical task systems in this problem an online algorithm must control the movement of a set of k servers represented as points in a metric space and handle requests that are also in the form of points in the space as each request arrives the algorithm must determine which server to move to the requested point the goal of the algorithm is to keep the total distance all servers move small relative to the total distance the servers could have moved by an optimal adversary who knows in advance the entire sequence of requests the problem was first posed by mark manasse lyle a mcgeoch and daniel sleator 1990 the most prominent open question concerning the k server problem is the so called k server conjecture also posed by manasse et al this conjecture states that there is an algorithm for solving the k server problem in an arbitrary metric space and for any number k of servers that has competitive ratio at least k manasse et al were able to prove their conjecture when k 2 and for more general values of k when the metric space is restricted to have exactly k 1 points chrobak and larmore 1991 proved the conjecture for tree metrics the special case of metrics in which all distances are equal is called the paging problem because it models the problem of page replacement algorithms in memory caches and was also already known to have a k competitive algorithm sleator and tarjan 1985 fiat et al 1990 first proved that there exists an algorithm with finite competitive ratio for any constant k and any metric space and finally koutsoupias and papadimitriou 1995 proved that work function algorithm wfa has competitive ratio 2 k 1 however despite the efforts of many other researchers reducing the competitive ratio to k or providing an improved lower bound remains open as of 2014 the most common believed scenario is that the work function algorithm is k competitive to this direction in 2000 bartal and koutsoupias showed that this is true for some special cases if the metric space is a line a weighted star or any metric of k 2 points in 2011 a randomized algorithm with competitive bound õ log 2 k log 3 n was found
the α ketoacid hydroxylamine kaha amide forming ligation is a chemical reaction that is used to join two unprotected fragments in peptide synthesis it is an alternative to the native chemical ligation ncl
knm er 1813 is a skull of the species homo habilis it was discovered in koobi fora kenya by kamoya kimeu in 1973 and is estimated to be 1 9 million years old its characteristics include an overall smaller size than other homo habilis finds but with a fully adult and typical h habilis morphology it is an adult the third molars were completely erupted and showed signs of wear with an estimated cranial capacity of only 510 cc the designation indicates specimen 1813 collected from the east shore of lake rudolf now lake turkana for the kenya national museums
knm wt 17000 aka the black skull is a fossilized skull of the species paranthropus aethiopicus it was discovered in west turkana kenya by alan walker in 1985 it is estimated to be 2 5 million years old it is an adult with an estimated cranial capacity of 410 cc its characteristics include a robust build with a prominent sagittal crest its coloration is due to the high manganese content of the material it was embedded in
the kabachnik – fields reaction is an organic reaction forming an α amino phosphonate from an amine a carbonyl compound and a dialkyl phosphonate aminophosphonates are synthetic targets of some importance as phosphorus analogues of α amino acids a bioisosteric this multicomponent reaction was independently discovered by martin izrailevich kabachnik and ellis k fields in 1952 kabachnik fields reaction the first step in this reaction is the formation of an imine followed by an addition reaction of the phosphonate p h bond into the c n double bond a pudovik reaction a related reaction is the mannich reaction the reaction is accelerated with a combination of dehydrating reagent and lewis acid the carbonyl component in the reaction is usually an aldehyde and sometimes a ketone
kabuki syndrome also previously known as kabuki makeup syndrome kms or niikawa – kuroki syndrome is a pediatric congenital disorder of suspected genetic origin with multiple congenital anomalies and intellectual disabilities it is quite rare affecting roughly one in 32 000 births it was identified and described in 1981 by two japanese groups led by the scientists norio niikawa and yoshikazu kuroki it is named kabuki syndrome because of the facial resemblance of affected individuals to stage makeup used in kabuki a japanese traditional theatrical form
the kadenacy effect is an effect of pressure waves in gases it is named after michel kadenacy who obtained a french patent for an engine utilizing the effect in 1933 there are also european and us patents in simple terms the momentum of the exhaust gas leaving the cylinder of an internal combustion engine creates a pressure drop in the cylinder which assists the flow of a fresh charge of air or fuel air mixture into the cylinder the effect can be maximized by careful design of the inlet and exhaust passages
in mathematics the kadison – singer problem posed in 1959 was a problem in functional analysis about whether certain extensions of certain linear functionals on certain c algebras were unique the statement was proven in 2013 the statement arose from work on the foundations of quantum mechanics done by paul dirac in the 1940 s and was formalized in 1959 by richard kadison and isadore singer the problem was subsequently shown to be equivalent to numerous open problems in pure mathematics applied mathematics engineering and computer science kadison singer and most later authors believed the statement to be false but in 2013 it was proven true by adam marcus daniel spielman and nikhil srivastava who received the 2014 pólya prize for the achievement the solution was made possible by a reformulation provided by joel anderson who showed in 1979 that his paving conjecture which only involves operators on finite dimensional hilbert spaces is equivalent to the kadison – singer problem nik weaver provided another reformulation in a finite dimensional setting and this version was proved true using random polynomials
kairo cancer is a cutaneous condition that may develop due to hydrocarbon fueled heat exposure from coal fired clothing warmers
kairosis is the literary effect of fulfillment in time this effect is normally associated with the epic novel genre of literature and can be understood by the analogy as catharsis is to the dramatic so kenosis is to the lyric so kairosis is to the epic novel it is derived from kermode s usage of kairos in literary aesthetics and is part of an ongoing debate within literary aesthetics about the limitations of the rhetorical use of the term kairos kairosis is the feeling of integration experienced by the reader of the novel or epic form it is experienced by the reader as the central protagonist s character and characterisation faces crisis and resolves itself into an explored and integrated personality this typically occurs by challenging unique and interesting characters with typical and stereotyped actions that are generally applicable to all people in the novel emma kairosis is developed when an individualistic young woman attempts to play matchmaker to the world as her personality is challenged by the stereotypical activity of courtship and matchmaking in a young woman s life she experiences a crisis in her character as contradictions within her personality become increasingly antagonistic when emma integrates these conflicts by performing the stereotyped action of completing a successful match the reader experiences kairosis as emma s character reaches a moment of synthesis that embodies the previous dialectical contradictions emma s problem was not to gain a social status of marriage we are always aware that she will be married by the end of the novel and there is no catharsis experienced as an unexpected climactic action rather we do not know if emma is worth marrying this kind of moral psychological question is at the heart of austen s work and the modern novel kairosis is experienced by the reader of the modern novel when the character reaches a moment of psychological integration in time kairosis has been used as part of an attempt in role playing game rpg theory to grapple with the issue of immersion
kaiser effect is an absence of acoustic emission at loads not exceeding the previous maximum load level when material undergoes repetitive loading patterns the kaiser effect results from discontinuities created in material during previous steps do not moving or expanding until the former stress is exceeded
kakute are rings made of iron or steel that were sometimes worn by the ninja and favored by the kunoichi having one to four metal spikes protruding from it the spikes were sometimes dipped in poison kakute were usually worn on the middle finger with the spikes hidden inside the hand and then used to attack when the enemy least expected the spikes were also excellent for holding onto an opponent striking across the face choking and sometimes climbing as well some kakute had a tab with a hole that was used for hojojutsu techniques in this sense the hojo rope could not be easily pulled away from the hands of the ninja or kunoichi since it was tied to the kakute ring on their finger
the kallak iron deposit is one of the largest unexploited iron ore deposits in sweden it is located between the villages of björkholmen and randijaur in the municipality of jokkmokk in the province of norrbotten in northern sweden the site is on the ancestral lands of the indigenous sami people and forms part of the reindeer winter grazing lands of the sami village of sirges the name kallak is the swedish form of gállok which is the original name of the place in the saami language the kallak north and kallak south prospects were identified by the geological survey of sweden in the 1940 s in the late 1960 s the sgu identified kallak north as containing 92 million tonnes of ore and kallak south as containing 29 million tonnes of ore at a grade of roughly 35 beowulf mining acquired the kallak north licence in 2006 and a drill program conducted in 2010 has found at least 175 mt of iron at an average grade of 30 beowulf acquired the kallak south licence from tasman metals limited in mid 2010 an ongoing drill program has shown kallak south to contain at least 400 million tonnes of iron at an average grade of 30 the combined kallak deposit contains at least 600 million tonnes of iron and it is believed that the north and south deposits are connected at depth to give a single iron deposit with a strike length of over 4 kilometers in mid 2010 an independent conceptual study performed by the raw materials group showed that the kallak north deposit which at the time was thought to contain 150 million tonnes of iron at 30 grading was commercially viable given the significant increase in tonnage at kallak an updated conceptual study is anticipated in 2011 the plans to establish a mine at the site has met resistance from the indigenous saami people as well as other local inhabitants on july 1 2013 protesters set up a road blockade in order to prevent test drilling on july 30 the blockade was dismantled by the police but on the next day the blockade was set up again in 2014 norrbotten county said no to further mining in kallak the case would be closed if the swedish governmental geology decision making body bergsstaten had agreed with norrbotten county however bergsstaten overruled the county and it is now up to the government of sweden to give a final answer to the question
kallmann syndrome is a rare genetic condition that is characterized by a failure to start or a failure to complete puberty it is also accompanied by a lack of sense of smell anosmia or a highly reduced sense of smell hyposmia the condition can occur in both males and females but is more commonly diagnosed in males left untreated patients with kallmann syndrome will almost invariably be infertile kallmann syndrome occurs due to a failure of the hypothalamus to release gnrh at the appropriate time as a result of the gnrh releasing neurones not migrating into the correct location during embryonic development kallmann syndrome is a form of hypogonadotropic hypogonadism hh approximately 50 of hh cases occur with no sense of smell and are classified as kallmann syndrome apart from the sense of smell there is no difference in the diagnosis or treatment between a case of hh or a case of kallmann syndrome the terminology used when describing cases of hh can vary the term congenital hypogonadotropic hypogonadism chh is now often used other terms used include idiopathic isolated hypogonadotropic hypogonadism ihh normosmic hypogonadotropic hypogonadism nhh or hypothalamic hypogonadism the term hh can be used to cover all cases including kallmann syndrome the term isolated gnrh deficiency igd has increasingly been used to describe this group of conditions as it highlights the primary cause of these conditions and distinguishes them from other conditions such as klinefelter syndrome or turner syndrome which share some similar symptoms but have a totally different etiology the term hypogonadism describes a low level of circulating sex hormones testosterone in males and estrogen and progesterone in females hypogonadism can occur through a number of different methods the use of the term hypogonadotropic relates to the fact that the hypogonadism found in hh is caused by a disruption in the production of the gonadotropin hormones normally released by the anterior pituitary gland known as luteinising hormone lh and follicle stimulating hormone fsh lh and fsh have a direct action on the ovaries in women and testes in men the absence of lh and fsh means that initially puberty will not commence at the correct time and subsequently the ovaries and testes will not perform their normal fertility function with the maturation and release of eggs in women and the production of sperm in men alongside their role in producing the sex hormones the underlying cause of the failure in production of lh and fsh is the impairment of the hypothalamus to release the hormone gnrh which in normal circumstances induces the production of lh and fsh without the correct release of gnrh the pituitary gland is unable to release lh and fsh which in turn prevents the ovaries and testes from functioning correctly this failure in gnrh production can either be due to the absence of the gnrh releasing neurones inside the hypothalamus or the inability of the hypothalamus to release gnrh in the correct pulsatile manner to ensure lh and fsh release from the pituitary hh can occur as an isolated condition with just the lh and fsh production being affected or it can occur in combined pituitary deficiency conditions such as charge syndrome to date at least twenty five different genes have so far been implicated in causing kallmann syndrome or other forms of hh through a disruption in the production or activity of gnrh the genes involved cover all forms of inheritance and no one gene defect has been shown to be common to all cases which makes genetic testing and inheritance prediction very problematic kallmann syndrome was described in a paper published in 1944 by franz josef kallmann a german american geneticist the link between anosmia and hypogonadism had already been noted however in particular by the spanish doctor aureliano maestre de san juan in 1856 the condition is sometimes known by his name in spanish speaking countries the condition has a low prevalence estimated as being between 1 in 4 000 and 1 in 10 000 for male hh cases overall and 1 in 50 000 for kallmann syndrome it is three to five times more common in males than females though whether this is a true sex imbalance or a reflection on how difficult ks hh is to diagnose correctly especially in females has yet to be fully established a more recent paper published in 2011 gave the incidence in the finnish population at 1 in 48 000 with a sex distinction of 1 in 30 000 for males and 1 in 125 000 for females
kang cancer is a cutaneous condition that may develop due to hydrocarbon fueled heat exposure from sleeping on coal fire heated bricks
a kangaroo pocket is a type of pocket usually featured on hoodies and sweatshirts that is large enough to fit both hands into the pocket is open on either side other names for it include muff pocket and hoodie pocket the pocket sits on the lower front section of the shirt it is usually large enough to contain some personal belongings the kangaroo pocket is most associated with casual clothing such as the hoodie or sweatshirt
kangri cancer is a type of squamous cell carcinoma of the skin it is found only in kashmir in the northwest of the indian subcontinent it occurs on the lower abdomen and inner thighs and is due to the use of a kangri a baked clay pot covered in wicker work used as a source for warmth by people in kashmir during cold weather the condition was described in 1881 by surgeons at the kashmir mission hospital and its cause was recognized in the early 20 th century as described by arthur neve despite current knowledge of the cause of this condition cases are still being reported other conditions associated with prolonged use of the kangri in this fashion include erythema ab igne a reticulate hypermelanosis with erythema
kangri ulcers are a cutaneous condition prevalent among the poorer classes of kashmir and a consequence of wearing warm embers it is unique to this area and may progress to kangri cancer
the kapitza – dirac effect is a quantum mechanical effect consisting of the diffraction of matter by a standing wave of light the effect was first predicted as the diffraction of electrons from a standing wave of light by paul adrien maurice dirac and pyotr kapitsa or peter kapitza in 1933 the effect relies on the wave – particle duality of matter as stated by the de broglie hypothesis in 1924
kaposi sarcoma ˈkæpəʃi sɑːrˈkoʊmə ks is a tumor caused by infection with human herpesvirus 8 hhv 8 also known as kaposi sarcoma associated herpesvirus kshv or ks agent it was originally described by moritz kaposi a hungarian dermatologist practicing at the university of vienna in 1872 it became more widely known as one of the aids defining illnesses in the 1980 s the viral cause for this cancer was discovered in 1994 although ks is now well established to be caused by a viral infection there is widespread lack of awareness of this even among persons at risk for kshv hhv 8 infection kaposi sarcoma ks is a systemic disease that can present with cutaneous lesions with or without internal involvement four subtypes have been described classic ks affecting middle aged men of mediterranean descent african endemic ks ks in iatrogenically immunosuppressed patients and aids related ks the erythematous to violaceous cutaneous lesions seen in ks have several morphologies macular patch plaque nodular and exophytic the cutaneous lesions can be solitary localized or disseminated ks can involve the oral cavity lymph nodes and viscera classic ks tends to be indolent presenting with erythematous or violaceous patches on the lower extremities african endemic ks and aids related ks tend to be more aggressive the aids related ks lesions often rapidly progress to plaques and nodules affecting the upper trunk face and oral mucosa the diagnosis can be made with a tissue biopsy and if clinically indicated internal imaging should be done once the diagnosis of ks has been made treatment is based on the subtype and the presence of localized versus systemic disease localized cutaneous disease can be treated with cryotherapy intralesional injections of vinblastine alitretinoin gel radiotherapy topical immunotherapy imiquimod or surgical excision extensive cutaneous disease and or internal disease may require intravenous chemotherapy and immunotherapy discontinuation or reduction of immunosuppressive therapy is recommended when ks arises in the setting of iatrogenic immunosuppression however with aids related ks highly active antiretroviral therapy haart has been shown to prevent or induce regression of ks some aids patients have complete resolution of the lesions and prolonged remission while continuing the therapy therefore haart should be considered first line treatment for these patients though they may require other treatments at the same time
kapur – toriello syndrome is a rare autosomal recessive genetic disorder the defining feature of kapur – toriello syndrome is abnormal morphology of the columella which extends below the margin of the nares
karak syndrome is a novel degenerative disorder it is a neurological disease involving excess cerebral iron accumulation the family who the disease was discovered in their siblings lived in karak a town in southern jordan it is characterized by ataxia inverted feet calcaneovarus dysarthric scanning speech with dystonic features dystonic movement of the tongue and facial muscles and choreiform movement was present in both upper and lower limbs being more marked in the lower limbs along with dystonic posture of the distal feet bradykinesiapresent in both upper and lower limbs dysmetria dysdiadochokinesia and intentional tremor were bilateral and symmetrical
in islamic mysticism karamat arabic کرامت ‎ ‎ karāmat also کرامات karāmāt is the ability to perform supernatural wonders by muslim saints it is a thaumaturgic gift akin to miracles sufis and alevis believe that whereas miracles can only be performed by prophets when allah creates the miracle in support to his prophets and are a testament to their prophethood karamat are extraordinary things performed by awliya who are not prophets but are friends of allah i e muslims who have reached a high rank of piety through proper knowledge of and practice of islam and most important through the constant zikr that is remembrance of allah allah creates karamaat to support the waliyy it is also believed that attribute of karamat is not only for muslim saints and is not parameter of sainthood holy personalities in all religions can perform karamat with some differences stories of companions of muhammad performing miraculous acts are already there in the hadith and miracles performed by various saints are ingrained throughout the entire history of islamic mysticism specifically in the sufi mysticism
karelianism was a late 19 th century cultural phenomenon in the grand duchy of finland and involved writers painters poets and sculptors since the publishing of the finnish national epic kalevala in 1835 compiled from karelian folk lore culture spheres in finland became increasingly curious about karelian heritage and landscape by the end of the 19 th century karelianism had become a major trend for many works of art and literature in finland in the movement karelia was seen as a sort of refuge for the essence of finnishness that had maintained its authenticity across centuries the phenomenon can be interpreted as a finnish version of european national romanticism the painters akseli gallen kallela and louis sparre are usually mentioned as the founders of the movement they were soon joined by the sculptor emil wikström the writers juhani aho eino leino and ilmari kianto the composers jean sibelius and p j hannikainen the architects yrjö blomstedt and victor sucksdorff and many others later towards the second world war some of the ideas of karelianism were taken over by an irredentist movement aspiring to create a larger finland thus some of the ideas put forward by karelianism were used as a motivation to the proposal of a greater finland a single state encompassing many finnic peoples
the kargil war order of battle kworbat is a deposition and systematic combatant structure of the indian army troops and the unified pakistan armed forces combat commands active in the region in 1999 the indian army orbat is based on the publications provided by the indian military authors news media and official sources the pakistan orbat is based on the intelligence information provided by the pakistani media both electronic and print media military authors and pakistani documentaries made after the conflict the pakistan orbat does not include the separatist fighters who claimed by india to be also involved in fighting atop the peaks of kargil however this claim has been strongly dismissed by the senior military commanders of pakistan armed forces command quoting that all soldiers were the active duty personnel of the pakistan armed forces
the karlqvist gap or karlqvist field is an electromagnetic phenomenon discovered in 1953 by the swedish engineer olle karlqvist 1922 1976 which is important in magnetic storage for computers karlqvist discovered the phenomenon while designing a ferromagnetic surface layer to the magnetic drum memory for the besk computer when designing a magnetic memory store the ferromagnetic layer must be studied to determine the variation of the magnetic field with permeability air gap layer thickness and other influencing factors the problem is non linear and extremely difficult to solve karlqvist s gap discovery shows that the non linear problem could be approximated by a linear boundary value for the two dimensional static field and the one dimensional transient field this linear calculation gives a first approximation karlqvist published his discovery in the 1954 paper calculation of the magnetic field in ferromagnetic layer of a magnetic drum at royal institute of technology kth
the barbara ann karmanos cancer institute is one of 45 national cancer institute designated comprehensive cancer treatment and research centers in the united states located in detroit michigan affiliated to wayne state university school of medicine the institute has 1 200 staff members including 300 doctors and 100 researchers the staff treats approximately 12 000 patients each year and operates with a budget of 260 million it conducts 800 cancer specific scientific investigations programs and clinical trials each year the institute has a phase 1 program one of 14 national cancer institute nci funded phase 1 programs in the united states gerold bepler is president and chief executive officer
karnal bunt also known as partial bunt is a fungal disease of wheat durum wheat and triticale the smut fungus tilletia indica a basidiomycete invades the kernels and obtains nutrients from the endosperm leaving behind waste products with a disagreeable odor that makes bunted kernels too unpalatable for use in flour or pasta while karnal bunt generally does not lead to devastating crop losses it has the potential to dramatically decrease yield and poses additional economic concerns through quarantines which limit the export of suspected infectious wheat products from certain areas including the u s several chemical control methods exist for karnal bunt of wheat but much work remains to be done in identifying resistant host varieties
in mathematical optimization the karush – kuhn – tucker kkt conditions also known as the kuhn – tucker conditions are first order necessary conditions for a solution in nonlinear programming to be optimal provided that some are satisfied allowing inequality constraints the kkt approach to nonlinear programming generalizes the method of lagrange multipliers which allows only equality constraints the system of equations corresponding to the kkt conditions is usually not solved directly except in the few special cases where a closed form solution can be derived analytically in general many optimization algorithms can be interpreted as methods for numerically solving the kkt system of equations the kkt conditions were originally named after harold w kuhn and albert w tucker who first published the conditions in 1951 later scholars discovered that the necessary conditions for this problem had been stated by william karush in his master s thesis in 1939
kasabach – merritt syndrome kms also known as hemangioma with thrombocytopenia is a rare disease usually of infants in which a vascular tumor leads to decreased platelet counts and sometimes other bleeding problems which can be life threatening it is also known as hemangioma thrombocytopenia syndrome it is named after haig haigouni kasabach and katharine krom merritt the two pediatricians who first described the condition in 1940
kashin – beck disease kbd is a chronic endemic type of osteochondropathy disease of the bone that is mainly distributed from northeastern to southwestern china involving 15 provinces tibet currently has the highest incidence rate of kbd in china southeast siberia and north korea are other affected areas kbd usually involves children ages 5 – 15 to date more than a million individuals have suffered from kbd the symptoms of kbd include joint pain morning stiffness in the joints disturbances of flexion and extension in the elbows enlarged inter phalangeal joints and limited motion in many joints of the body death of cartilage cells in the growth plate and articular surface is the basic pathologic feature this can result in growth retardation and secondary osteoarthrosis histological diagnosis of kbd is particularly difficult clinical and radiological examinations have proved to be the best means for identifying kbd little is known about the early stages of kbd before the visible appearance of the disease becomes evident in the destruction of the joints this disease has been recognized for over 150 years but its etiology has not yet been completely defined currently the accepted potential causes of kbd include mycotoxins present in grain trace mineral deficiency in nutrition and high levels of fulvic acid in drinking water selenium and iodine have been considered the most important deficiencies associated with kbd mycotoxins produced by fungi can contaminate grain which may cause kbd because mycotoxins cause the production of free radicals t 2 is the mycotoxin implicated with kbd produced by members of several fungal genera t 2 toxin can cause lesions in hematopoietic lymphoid gastrointestinal and cartilage tissues especially in physeal cartilage fulvic acid present in drinking water damages cartilage cells selenium supplementation in selenium deficient areas has been shown to prevent this disease however selenium supplementation in some areas showed no significant effect proving that deficiency of selenium may not be the dominant cause in kbd recently a significant association between snp rs 6910140 of col 9 a 1 and kashin – beck disease was discovered genetically suggesting a role of col 9 a 1 in the development of kashin – beck disease
kata 型 or 形 literally form a japanese word are detailed choreographed patterns of movements practised either solo or in pairs the term form is used for the corresponding concept in non japanese martial arts in general kata are used in many traditional japanese arts such as theatre forms like kabuki and schools of tea ceremony chado but are most commonly known for the presence in the martial arts kata are used by most japanese and okinawan martial arts such as aikido judo kendo and karate
the kate middleton effect also the kate effect the duchess of cambridge effect or the duchess effect is the trend effect that catherine duchess of cambridge is reported to have had on others for example in sales of coral coloured jeans although middleton was in the public eye for many years as the girlfriend of prince william the effect began after the announcement of the couple s engagement in november 2010 which spawned a media frenzy according to newsweek the kate effect may be worth £ 1 billion to the uk fashion industry while tony dimasso l k bennett ’ s us president stated in 2012 when she does wear something it always seems to go on a waiting list her wedding dress was put on display at buckingham palace in the summer of 2011 the display helped to raise approximately £ 8 million for the royal collection as well as the charitable fund of the duke and duchess and was reported to have drawn a record number of visitors this charitable contribution was enhanced in 2012 when the duchess gave her first public speech for her patronage each east anglia s children s hospices and was seen wearing one of their charity bracelets the bracelet then went on to sell out rapidly although the number of available units beforehand was not known in august 2013 the kate effect was purportedly felt by the maternity brand seraphine maternity when the duchess wore one of the brand s dresses in their first official portraits with prince george reportedly increasing turnover by 50 however the kate effect may be exaggerated because of her penchant for wearing styles that have long sold out and that habit of choosing last season s designs meant that those wishing to emulate her look had already missed out a designer who worked with kate was reported to say that business was more likely to be boosted by us reality television stars the ceo of whistles agreed remarking we do short runs by the time you see pictures of kate we ve probably sold out anyway the ceo also described the duchess as a great advert but no more than that
kato s conjecture is a mathematical problem named after mathematician tosio kato of the university of california berkeley kato initially posed the problem in 1953 kato asked whether the square root of certain elliptic operators defined via functional calculus are analytic the problem remained unresolved for nearly a half century until it was jointly solved in 2001 by pascal auscher steve hofmann michael lacey alan mcintosh and philippe tchamitchian
katrina cough is a putative respiratory illness thought to be linked to exposure to mold and dust after the 2005 hurricane katrina in the united states first described by doctors treating patients in the metro new orleans area symptoms include cough sinus headache congestion runny nose and sore throat and pink eye this condition may make immunocompromised individuals more susceptible to bacterial bronchitis and sinusitis most patients are treated with antihistamines nasal sprays and or antibiotics the louisiana office of public health conducted a case control study of emergency room visits in new orleans in the aftermath of hurricane katrina the oph distributed a questionnaire to patients seeking treatment for cough sinus drip sneezing wheezing chest congestion swollen red and puffy eye s and sore throat according to the study state epidemiologists found no increase in the rate of new orleans area respiratory illnesses although rates were found to be no different in comparison to state and country rates the study showed that people with chronic sinus or respiratory symptoms were more affected by the hurricane state epidemiologist dr raoult ratard disputed the existence of any disease cluster associated with the hurricane in 2006 there is no such thing as a single condition such as ‘ katrina cough ’ that would be different from the bacterial and viral respiratory conditions we would expect to see at that time of year no such outbreak occurred because of hurricane katrina starting in 2008 henry glindmeyer researcher and professor of pulmonary critical care and environmental medicine at the tulane university school of medicine is conducting a five year study to determine if workers in new orleans face risks from inhalant exposure to minute particles such as mold fungi or bacteria the study is funded by the national institute for occupational safety and health an agency of the centers for disease control and prevention which is providing 1 86 million
katz syndrome is a rare congenital disorder presenting as a polymalformative syndrome characterized by enlarged viscera hepatomegaly diabetes and skeletal anomalies that result in a short stature cranial hyperostosis and typical facial features it is probably a variant of the autosomal recessive type of craniometaphyseal dysplasia
the kauffmann olefination is a chemical reaction to convert aldehydes and ketones to olefins with a terminal methylene group this reaction was discovered by the german chemist thomas kauffmann and is related to the better known tebbe olefination or wittig reaction
kaufman oculocerebrofacial syndrome is an autosomal recessive congenital disorder characterized by mental retardation microbrachycephaly long narrow face upslanting palpebral fissures eye abnormalities highly arched palate preauricular skin tags and small mandible it was characterized in 1971 eight cases had been identified as of 1995
kautsky effect also named fluorescence transient fluorescence induction or fluorescence decay is a phenomenon consisting on a typical variation on the behavior of a plant fluorescence when is exposed to light it was discovered in 1931 by h kautsky and a hirsch when dark adapted photosynthesising cells are illuminated with continuous light chlorophyll fluorescence displays characteristic changes in intensity accompanying the induction of photosynthetic activity
kawasaki disease is a disease in which blood vessels throughout the body become inflamed the most common symptoms include a fever that lasts for more than five days and is not controlled by usual medications large lymph nodes in the neck a rash in the genital area and red eyes lips palms or bottoms of the feet other symptoms include sore throat and diarrhea within three weeks of the onset of symptoms the skin from the hands and feet may peel recovery then typically occurs in some children coronary artery aneurysms may form in the heart the cause is unknown it may be due to an infection triggering an autoimmune response in those who are genetically predisposed it is not spread between people diagnosis is usually based on a person s signs and symptoms other tests such as an ultrasound of the heart and blood tests may support the diagnosis other conditions that may present similarly include scarlet fever and juvenile rheumatoid arthritis initially treatment is typically with high doses of aspirin and immunoglobulin usually with treatment fever resolves within 24 hours and there is a full recovery if the coronary arteries are involved ongoing treatment or surgery may occasionally be required without treatment coronary artery problems occur in up to 25 and about 1 die with treatment the risk of death is 0 17 kawasaki disease is rare it affects between 8 and 67 per 100 000 people under the age of five except in japan where it affects 124 per 100 000 it is much less common after the age of five boys are more commonly affected than girls the disorder was first described in 1967 by tomisaku kawasaki in japan
kayser – fleischer rings kf rings are dark rings that appear to encircle the iris of the eye they are due to copper deposition in part of the cornea descemet s membrane as a result of particular liver diseases they are named after dr bernhard kayser and dr bruno fleischer the german doctors who first described them in 1902 and 1903 initially thought to be due to the accumulation of silver they were first demonstrated to contain copper in 1934
kearns – sayre syndrome abbreviated kss also known as oculocraniosomatic disorder or oculocraniosomatic neuromuscular disorder with ragged red fibers is a mitochondrial myopathy with a typical onset before 20 years of age kss is a more severe syndromic variant of chronic progressive external ophthalmoplegia abbreviated cpeo a syndrome that is characterized by isolated involvement of the muscles controlling movement of the eyelid levator palpebrae orbicularis oculi and eye extra ocular muscles this results in ptosis and ophthalmoplegia respectively kss involves a combination of the already described cpeo as well as bilateral pigmentary retinopathy and cardiac conduction abnormalities other symptoms may include cerebellar ataxia proximal muscle weakness deafness diabetes mellitus growth hormone deficiency hypoparathyroidism and other endocrinopathies in both of these diseases muscle involvement may begin unilaterally but always develops into a bilateral deficit and the course is progressive this discussion is limited specifically to the more severe and systemically involved variant
ked itch is a cutaneous condition caused by sheep ked melophagus ovinus which feed by thrusting its sharp mouth parts into the skin and sucking blood
the keidel vacuum tube was a type of blood collecting device first manufactured by hynson wescott and dunning in around 1922 this vacuum was one of the first evacuated systems predating the more well known vacutainer its primary use was to test for syphilis and typhoid fever
keloid also keloidal scar is the formation of a type of scar which depending on its maturity is composed mainly of either type iii early or type i late collagen it is a result of an overgrowth of granulation tissue collagen type 3 at the site of a healed skin injury which is then slowly replaced by collagen type 1 keloids are firm rubbery lesions or shiny fibrous nodules and can vary from pink to the colour of the patient s flesh or red to dark brown in color a keloid scar is benign and not contagious but sometimes accompanied by severe itchiness pain and changes in texture in severe cases it can affect movement of skin keloid scars are seen 15 times more frequently in people of african descent than in people of european descent keloids should not be confused with hypertrophic scars which are raised scars that do not grow beyond the boundaries of the original wound
keloid disorder results in very hard to treat fibro proliferative cutaneous connective tissue secondary to dysregulation in various skin repair and healing processes in individuals who are genetically predisposed to this disorder although reported in individuals from almost all ethnic backgrounds the disorder is more common among two distinct and genetically distant populations africans african americans and asians the only groups of individuals who may be spared from developing keloids are albinos making the case for a relationship between melanin production and susceptibility to keloid formation at least among dark skinned individuals keloid disorder has a very diverse phenotype and can present itself either as a single small spot on the skin of the affected individual or often involving several areas of the skin in some patients keloid lesions can grow and form a large size skin tumor from the onset of development each keloid lesion follows its own particular clinical course some patients develop only one keloid lesion which only grows to a particular size and it stops growing thereafter some patients can develop multiple lesions on multiple sites of the body lack of understanding of the disorder even reflects itself in terminology used to describe this illness terms such as keloid scarring or keloid scars that are commonly used even by those who treat keloid patients these terms do not properly describe this disorder and erroneously apply a lesser importance to this genetic skin disorder a genetic condition that results in formation of large skin tumors or itching pain and burning sensation a condition that disables certain patients and covers 20 30 of their skin a condition that some treat it with radiation therapy is not a condition of “ skin scarring ” it is indeed a true skin disorder the national institute of health webpage on keloid states that “ keloids often do not need treatment ”
kemerovo tickborne viral fever is an aparalytic febrile illness accompanied by meningism following tick bite the causative agent is a zoonotic orbivirus first described in 1963 in western siberia by mikhail chumakov and coworkers the virus has some 23 serotypes and can occur in coinfections with other orbiviruses and tick transmitted encephalitis viruses complicating the course of illness rodents and birds are the primary vertebrate hosts of the virus ixodes persulcatus ticks are a vector of the virus kemerovo and related viruses may be translocated distances in the environment by migratory birds
in telecommunications the kendall effect is a spurious pattern or other distortion in a facsimile it is caused by unwanted modulation products which arise from the transmission of the carrier signal and appear in the form of a rectified baseband that interferes with the lower sideband of the carrier the kendall effect occurs principally when the single sideband width is greater than half of the facsimile carrier frequency
kendo kata are fixed patterns that teach kendoka kendo practitioners the basic elements of swordsmanship there are two roles uchidachi 打太刀 the teacher and shidachi 仕太刀 the student
kennel cough also known as canine infectious tracheobronchitis is an upper respiratory infection affecting dogs there are multiple causative agents the most common being the bacterium bordetella bronchiseptica found in 78 7 of cases in southern germany followed by canine parainfluenza virus 37 7 of cases and to a lesser extent canine coronavirus 9 8 of cases it is highly contagious however adult dogs may display immunity to reinfection even under constant exposure kennel cough is so named because the infection can spread quickly among dogs in the close quarters of a kennel or animal shelter viral and bacterial causes of canine cough are spread through airborne droplets produced by sneezing and coughing these agents also spread through contact with contaminated surfaces symptoms begin after a several day incubation period post exposure and in most cases will clear up on their own however in young puppies or immunocompromised animals mixed or secondary infections can progress to lower respiratory infections such as pneumonia
keppen – lubinsky syndrome is an extremely rare congenital disorder the minimal clinical criteria for the keppen – lubinsky syndrome are as follows normal growth parameters at birth postnatal growth failure peculiar facial appearance with skin tightly adherent to facial bones generalized lipodystrophy and development delay
a keratin disease or keratinopathy is a genetic disorder of one of the keratin genes an example is monilethrix the first to be identified was epidermolysis bullosa simplex examples include
keratin implantation cysts are cysts lined by an epidermal sac and filled with a form of keratin they are a primarily cutaneous condition but they are occasionally observed under the nail anatomy of a finger or toe
keratinizing metaplasia is a condition affecting the epithelial surfaces of the body it is caused by a dietary deficiency of vitamin a a fat soluble vitamin that is most often found in fats milk and some leafy vegetables
keratitis is a condition in which the eye s cornea the front part of the eye becomes inflamed the condition is often marked by moderate to intense pain and usually involves any of the following symptoms pain impaired eyesight photophobia red eye and a gritty sensation
keratitis – ichthyosis – deafness syndrome also known as erythrokeratodermia progressiva burns ichthyosiform erythroderma corneal involvement and deafness and kid syndrome presents at birth infancy and is characterized by pregressive corneal opacification either mild generalized hyperkeratosis or discrete erythematous plaques and neurosensory deafness it is caused by a mutation in connexin 26
keratoacanthoma ka is a common low grade unlikely to metastasize or invade skin tumour that is believed to originate from the neck of the hair follicle the defining characteristic of ka is that it is dome shaped symmetrical surrounded by a smooth wall of inflamed skin and capped with keratin scales and debris it grows rapidly reaching a large size within days or weeks and if untreated for months will almost always starve itself of nourishment necrose die slough and heal with scarring ka is commonly found on sun exposed skin often face forearms and hands under the microscope keratoacanthoma very closely resembles squamous cell carcinoma in order to differentiate between the two almost the entire structure needs to be removed and examined while some pathologists classify ka as a distinct entity and not a malignancy about 6 of clinical and histological keratoacanthomas do progress to invasive and aggressive squamous cell cancers some pathologists may label ka as well differentiated squamous cell carcinoma keratoacanthoma variant and prompt definitive surgery may be recommended
keratoconjunctivitis is inflammation itis of the cornea and conjunctiva when only the cornea is inflamed it is called keratitis when only the conjunctiva is inflamed it is called conjunctivitis there are several potential causes of the inflammation keratoconjunctivitis sicca is used when the inflammation is due to dryness sicca means dryness in medical contexts it occurs with 20 of rheumatoid arthritis patients the term vernal keratoconjunctivitis vkc is used to refer to keratoconjunctivitis occurring in spring and is usually considered to be due to allergens atopic keratoconjunctivitis is one manifestation of atopy epidemic keratoconjunctivitis is caused by an adenovirus infection infectious bovine keratoconjunctivitis ibk is a disease affecting cattle caused by the bacteria moraxella bovis pink eye in sheep and goat is another infectious keratoconjunctivitis of veterinary concern mostly caused by chlamydophila pecorum superior limbic keratoconjunctivitis is thought to be caused by mechanical trauma keratoconjunctivitis photoelectrica arc eye means inflammation caused by photoelectric uv light it is a type of ultraviolet keratitis such uv exposure can be caused by arc welding without wearing protective eye glass or by high altitude exposure from sunlight reflected from snow snow blindness the inflammation will only appear after about 6 to 12 hours it can be treated by rest as the inflammation usually heals after 24 – 48 hours proper eye protection should be worn to prevent keratoconjunctivitis photoelectrica
keratoconus kc kcn ktcn is a degenerative disorder of the eye in which structural changes within the cornea cause it to thin and change to a more conical shape than the more normal gradual curve keratoconus can cause substantial distortion of vision with multiple images streaking and sensitivity to light all often reported by the person it is typically diagnosed in the person s adolescent years if both eyes are significantly affected the deterioration in vision can affect the person s ability to drive a car or read normal print in most cases corrective lenses fitted by a specialist are effective enough to allow the person to continue to drive legally and likewise function normally further progression of the disease may require surgery for which several options are available including intrastromal corneal ring segments corneal collagen cross linking mini asymmetric radial keratotomy corneal intrastromal implantation system cisis topography guided photorefractive keratectomy prk topography guided conductive keratoplasty phakic intraocular lenses and in 25 of cases corneal transplantation estimates of the rates for keratoconus range from 1 in 500 to 1 in 2000 people but difficulties with differential diagnosis cause uncertainty it seems to occur in populations throughout the world although it is observed more frequently in certain ethnic groups such as south asians environmental and genetic factors are considered possible causes but the exact cause is uncertain it has been associated with detrimental enzyme activity within the cornea the word is from greek kéras horn cornea and latin cōnus cone
a keratocyst is a type of cutaneous cyst they appear similar to epidermoid cysts however are not limited to a specified location on the body keratocyst are most often reported in persons with nevoid basal cell carcinoma syndrome
a keratocystic odontogenic tumour also keratocystic odontogenic tumor kcot is a rare and benign but locally aggressive developmental cystic neoplasm it most often affects the posterior mandible it used to be called odontogenic keratocyst okc
keratoderma is a hornlike skin condition
keratoderma blennorrhagicum etymologically meaning keratinized kerato skin derma mucousy blenno discharge rrhagia also called keratoderma blennorrhagica are skin lesions commonly found on the palms and soles but which may spread to the scrotum scalp and trunk the lesions may resemble psoriasis keratoderma blennorrhagicum is commonly seen as an additional feature of reactive arthritis in almost 15 of male patients the appearance is usually of a vesico pustular waxy lesion with a yellow brown colour these lesions may join together to form larger crusty plaques with desquamating edges
keratoderma climactericum also known as climacteric keratoderma haxthausen s disease and acquired plantar keratoderma is a skin condition characterized by hyperkeratosis of the palms and soles beginning at about the time of menopause
keratoglobus from greek kerato horn cornea and latin globus round is a degenerative non inflammatory disorder of the eye in which structural changes within the cornea cause it to become extremely thin and change to a more globular shape than its normal gradual curve it causes corneal thinning primarily at the margins resulting in a spherical slightly enlarged eye it is sometimes equated with megalocornea
keratolytic winter erythema kwe also known as erythrokeratolysis hiemalis oudtshoorn disease and oudtshoorn skin is a rare autosomal dominant skin disease of unknown etiology which causes erythema redness and keratolysis peeling of the skin on the palms and soles onset increased prominence and severity usually occurs during winter it is a type of genodermatosis the name oudtshoorn skin derives from the town of oudtshoorn in the western cape province of south africa where the disorder was first described it is one of several genetic disorders known to be highly prevalent among the afrikaner population
keratomalacia is an eye disorder that results from vitamin a deficiency vitamin a is required to maintain specialized epithelia such as in the cornea and conjunctiva the precise mechanism is still not known but vitamin a is necessary for the maintenance of the specialized epithelial surfaces of the body a lack of vitamin a leads to atrophic changes in the normal mucosal surface with loss of goblet cells and replacement of the normal epithelium by an inappropriate keratinized stratified squamous epithelium in addition the substantia propria of the cornea breaks down and liquefies resulting in keratomalacia the resulting cornea becomes totally opaque which is one of the most common reasons for blindness around the world particularly in developing countries
keratosis from keratinocyte the prominent cell type in the epidermis and osis abnormal is a growth of keratin on the skin or on mucous membranes more specifically it can refer to actinic keratosis also known as solar keratosis hydrocarbon keratosis keratosis pilaris kp also known as follicular keratosis seborrheic keratosis actinic keratoses are pre malignant growths seborrheic keratoses are not pre malignant
keratosis follicularis spinulosa decalvans also known as siemens 1 syndrome is a rare x linked disorder described by siemens in 1926 a disease that begins in infancy with keratosis pilaris localized on the face then evolves to more diffuse involvement an association with sat 1 has been suggested
keratosis linearis with ichthyosis congenital and sclerosing keratoderma syndrome also known as klick syndrome is a cutaneous condition characterized by ichthyosis and keratoderma it is associated with pomp
keratosis pharyngis is a medical condition where keratin grows on the surface of the pharynx that is the part of the throat at the back of the mouth keratin is a protein that normally occurs as the main constituent of hair and nails it is characterized by the presence of whitish yellow dots on the pharyngeal wall tonsils or lingual tonsils they are firmly adherent and cannot be wiped off the surrounding region does not show any sign or inflammation or any other constitutional signs the disease usually shows spontaneous regression one patient who was diagnosed with keratosis pharyngis had white spots on the base of the tongue and on the pharynx and hurt a little when swallowing no treatment was found to help but the condition went away by itself eventually
keratosis pilaris kp also follicular keratosis lichen pilaris or colloquially chicken skin is a common autosomal dominant genetic follicular condition characterized by the appearance of rough slightly red bumps on light skin and brown bumps on darker skin it most often appears on the back outer sides of the upper arm though the forearm can also be affected face thighs and buttocks kp can also occur on the hands and tops of legs sides or any body part except glabrous skin like the palms or soles of feet often the lesions will appear on the face which may be mistaken for acne
keratosis pilaris atrophicans faciei also known as folliculitis rubra keratosis pilaris rubra atrophicans faciei lichen pilare lichen pilaire ou xerodermie pilaire symetrique de la face ulerythema ophryogenes and xerodermie pilaire symetrique de la face begins in infancy as follicular papules with perifollicular erythema initially the lesions are restricted to the lateral eyebrows but with time spread to involve the cheeks and forehead and may also be associated with keratosis pilaris on the extremities and buttocks
keratosis punctata of the palmar creases also known as hyperkeratosis penetrans hyperkeratosis punctata keratodermia punctata keratosis punctata keratotic pits of the palmar creases lenticular atrophia of the palmar creases and punctate keratosis of the palmar creases is a common skin disorder that occurs most often in black patients with skin lesions that are 1 to 5 mm depressions filled with a comedo like keratinous plug treatment with etretinate has been described
kerion is the result of the host s response to a fungal ringworm infection of the hair follicles of the scalp occasionally the beard that can be accompanied by secondary bacterial infection s it usually appears as raised spongy lesions and typically occurs in children this honeycomb is a painful inflammatory reaction with deep suppurative lesions on the scalp follicles may be seen discharging pus there may be sinus formation and rarely mycetoma like grains are produced it is usually caused by dermatophytes fungal infections of the skin affecting humans and animals such as trichophyton verrucosum t mentagrophytes and microsporum canis treatment with oral griseofulvin common
kernicterus is a bilirubin induced brain dysfunction bilirubin is a highly neurotoxic substance that may become elevated in the serum a condition known as hyperbilirubinemia hyperbilirubinemia may cause bilirubin to accumulate in the gray matter of the central nervous system potentially causing irreversible neurological damage depending on the level of exposure the effects range from clinically unnoticeable to severe brain damage and even death newborns are especially vulnerable to hyperbilirubinemia induced neurological damage and therefore must be carefully monitored for alterations in their serum bilirubin levels
keshan disease is a congestive cardiomyopathy caused by a combination of dietary deficiency of selenium and the presence of a mutated strain of coxsackievirus named after keshan county of heilongjiang province northeast china where symptoms were first noted these symptoms were later found prevalent in a wide belt extending from northeast to southwest china all due to selenium deficient soil the disease peaked in 1960 – 1970 claiming thousands of lives often fatal the disease afflicts children and women of child bearing age characterized by heart failure and pulmonary edema over decades supplementation with selenium reduced this affliction it had been linked to the coxsackie b virus current research suggests that the lack of selenium results in a more virulent strain of the coxsackievirus becoming the dominant viral species present in the population of virus but the mechanism of this selection event is unclear the disease got its name from the province in which it was discovered keshan china since its discovery it can also be found in new zealand and finland keshan disease results from a selenium deficiency which is a nutrient we receive in our diet from eating foods that were grown in selenium enriched soils because of that factor keshan deficiency can be found anywhere that the level of selenium present in the soil is low an individual with keshan disease will have an abnormally large heart keshan disease can also lead to higher rates of cancer cardiovascular disease hypertension and strokes in addition an individual can experience eczema psoriasis arthritis cataracts alcoholism and infections
ketene cycloadditions are the reactions of the pi system of ketenes with unsaturated compounds to provide four membered or larger rings 2 2 3 2 and 4 2 variants of the reaction are known
ketoacidosis is a metabolic state associated with high concentrations of ketone bodies formed by the breakdown of fatty acids and the deamination of amino acids the two common ketones produced in humans are acetoacetic acid and β hydroxybutyrate ketoacidosis is a pathological metabolic state marked by extreme and uncontrolled ketosis in ketoacidosis the body fails to adequately regulate ketone production causing such a severe accumulation of keto acids that the ph of the blood is substantially decreased in extreme cases ketoacidosis can be fatal ketoacidosis is most common in untreated type 1 diabetes mellitus when the liver breaks down fat and proteins in response to a perceived need for respiratory substrate prolonged alcoholism may lead to alcoholic ketoacidosis ketoacidosis can be smelled on a person s breath this is due to acetone a direct by product of the spontaneous decomposition of acetoacetic acid it is often described as smelling like fruit or nail polish remover ketosis may also smell but the odor is usually more subtle due to lower concentrations of acetone treatment consists most simply of correcting blood sugar and insulin levels which will halt ketone production if the severity of the case warrants more aggressive measures intravenous sodium bicarbonate infusion can be given to raise blood ph back to an acceptable range however serious caution must be exercised with iv sodium bicarbonate to avoid the risk of equally life threatening hypernatremia
ketonic decarboxylation also known as ketonization is a type of organic reaction and a decarboxylation converting two equivalents of a carboxylic acid to a symmetric ketone by the application of heat with expulsion of one equivalent of water and one equivalent of carbon dioxide bases promote this reaction the reaction mechanism likely involves nucleophilic attack of the alpha carbon of one acid group on the other acid group s carbonyl possibly as a concerted reaction with the decarboxylation the initial formation of an intermediate carbanion with decarboxylation from one acid group prior to the nucleophilic attack has been proposed but is unlikely since the byproduct resulting from the carbanion s protonation by the acid has never been reported this reaction is different from oxidative decarboxylation which proceeds through a radical mechanism and is characterised by a different product distribution in isotopic labeling experiments with two different carboxylic acids with two different carboxylic acids the reaction behaves poorly because of poor selectivity except when one of the acids for example a small volatile one is used in large excess
ketonuria is a medical condition in which ketone bodies are present in the urine it is seen in conditions in which the body produces excess ketones as an indication that it is using an alternative source of energy it is seen during starvation or more commonly in type i diabetes mellitus production of ketone bodies is a normal response to a shortage of glucose meant to provide an alternate source of fuel from fatty acids
ketosis is a metabolic state in which some of the body s energy supply comes from ketone bodies in the blood in contrast to a state of glycolysis in which blood glucose provides most of the energy ketosis is a nutritional process characterised by serum concentrations of ketone bodies over 0 5 mm with low and stable levels of insulin and blood glucose it is almost always generalized with hyperketonemia that is an elevated level of ketone bodies in the blood throughout the body ketone bodies are formed by ketogenesis when liver glycogen stores are depleted or from metabolising medium chain triglycerides the main ketone bodies used for energy are acetoacetate and β hydroxybutyrate and the levels of ketone bodies are regulated mainly by insulin and glucagon most cells in the body can use both glucose and ketone bodies for fuel and during ketosis free fatty acids and glucose synthesis gluconeogenesis fuel the remainder longer term ketosis may result from fasting or staying on a low carbohydrate diet and deliberately induced ketosis serves as a medical intervention for various conditions such as intractable epilepsy and the various types of diabetes in glycolysis higher levels of insulin promote storage of body fat and block release of fat from adipose tissues while in ketosis fat reserves are readily released and consumed for this reason ketosis is sometimes referred to as the body s fat burning mode
keutel syndrome ks is a rare autosomal recessive genetic disorder characterized by abnormal diffuse cartilage calcification hypoplasia of the mid face peripheral pulmonary stenosis hearing loss short distal phalanges tips of the fingers and mild mental retardation individuals with ks often present with peripheral pulmonary stenosis brachytelephalangism sloping forehead midface hypoplasia and receding chin it is associated with abnormalities in the gene coding for matrix gla protein mgp being an autosomal recessive disorder it may be inherited from two unaffected abnormal mgp carrying parents thus people who inherit two affected mgp genes will likely inherit ks it was first identified in 1972 as a novel rare genetic disorder sharing similar symptoms with chondrodysplasia punctata multiple forms of chondrodysplasia punctata share symptoms consistent with ks including abnormal cartilage calcification forceful respiration brachytelephalangism hypotonia psychomotor delay and conductive deafness yet peripheral pulmonary stenosis remains unique to ks no chromosomal abnormalities are reported in affected individuals suggesting that familial consanguinity relates to the autosomal recessive mode of inheritance also despite largely abnormal calcification of regions including the larynx tracheobronchial tree nose pinna anatomy and epiglottis patients exhibit normal serum calcium and phosphate levels
in evolutionary biology a key innovation also known as an adaptive breakthrough or key adaptation is a novel phenotypic trait that allows subsequent radiation and success of a taxonomic group typically they bring new abilities that allows the taxa to rapidly diversify and invade niches that were not previously available the phenomenon helps to explain how some taxa are much more diverse and have many more species than their sister taxa the term was first used in 1949 by alden h miller who defined it as key adjustments in the morphological and physiological mechanism which are essential to the origin of new major groups although a broader contemporary definition holds that a key innovation is an evolutionary change in individual traits that is causally linked to an increased diversification rate in the resulting clade the theory of key innovations has come under attack because it is hard to test in a scientific manner but there is evidence to support the idea
no two copies of keys are exactly the same even if they were both made from key blanks that are struck from the same mould or cut from the same duplicating milling machine with no changes to the bitting settings in between even under these favorable circumstances there will be minute differences between the two key shapes though their key relevance is extremely high in all machining work there are measurable amounts of difference between the design specification of an object and its actual manufactured size in locksmithing the allowable tolerance is decided by the range of minute differences between a key s size and shape in comparison to the size and shape required to turn the tumblers within the lock key relevance is the measure of similarity between the key and the optimal size needed to fit the lock or it is the similarity between a duplicate key and the original it is seeking to replicate key relevance cannot be deduced from a key code since the key code merely refers to a central authoritative source for designed shapes and sizes of keys typical modern keys require a key relevance of approximately 0 03 millimetres 0 0012 in to 0 07 millimetres 0 0028 in accuracy within 0 75 to 1 75 in order to operate
keyboard maestro is a closed source commercial mac os x based application that allows automation of routine functions such as navigating running applications opening documents typing text expanding abbreviations and controlling web applications by means of a visual programming language with support for variables styled clipboards functions and text tokens if then else logic loops and other functions features include recording and designing macros clipboard history saved clipboards and navigation through applications and windows macros are organised into groups which can be limited to operate within certain applications keyboard maestro was created and first released in 2002 by michael kamprath and purchased by stairways software in 2004 and has been in continuous development since then
the keynes effect is the effect that changes in the price level have upon goods market spending via changes in interest rates as prices fall a given nominal money supply will be associated with a larger real money supply causing interest rates to fall and in turn causing investment spending on physical capital to increase this implies that insufficient demand in the product market cannot exist forever because insufficient demand will cause a lower price level resulting in increased demand there are two cases in which the keynes effect does not occur in the liquidity trap when the lm curve is horizontal and thus changes in the real money supply do not affect interest rates and when expenditure is inelastic with respect to unresponsive to interest rates when the is curve is vertical the patinkin pigou real balance effect suggests that due to wealth effects of changes in the price level upon spending itself insufficient demand cannot persist even in the two cases in which the keynes effect does not operate
keyword spotting is a subfield of speech recognition that deals with the identification of keywords in utterances there are several types of keyword spotting keyword spotting in unconstrained speech keyword spotting in isolated word recognition keyword spotting in unconstrained speech appears when keywords may not be separated from other words and no grammar is enforced on the sentence containing them some algorithms used for this task are sliding window and garbage model k best hypothesis iterative viterbi decoding keyword spotting in isolated word recognition appears when the keywords are separated from other texts by silences the main technique that applied in such problems is dynamic time warping
the kharasch addition is an organic reaction and a metal catalysed free radical addition of cxcl 3 compounds x cl br h to alkenes the reaction was discovered by morris s kharasch in the 1940 s the basic reaction scheme runs as follows r 2 c ch 2 r x → r 2 cx ch 2 r and proceeds through the cxcl 2 free radical examples of organohalides are carbon tetrachloride and chloroform the addition is an anti markovnikov addition early work linked the addition to olefin polymerization and is therefore considered a first step into what was to become atom transfer radical polymerization an example of karasch addition is the synthesis of 1 1 3 trichloro n nonane from 1 octene chloroform and ferric chloride
in chemical synthesis the kharasch – sosnovsky reaction is a catalytic reaction in which asymmetric allylic oxidation and benzylic oxidation strategies are used for constructing chiral c – o bonds via c – h bond activation
a khodadoust line or chronic focal transplant reaction is a medical sign that indicates a complication of corneal graft surgery on the eye this method is called khodadoust line because of many years research about this by professor ali asghar khodadoust this medical condition is similar to organ rejection after an organ transplant except that it involves immunological rejection of a transplanted cornea rather than an internal organ a khodadoust line is made up of mononuclear cells white blood cells these cells appear at the vascularized edge of the recently transplanted cornea if untreated the line of white blood cells will move across and damage the endothelial cells of the cornea over the space of several days
the kibibit is a multiple of the bit a unit of digital information storage prefixed by the standards based multiplier kibi symbol ki a binary prefix meaning 210 the unit symbol of the kibibit is kibit 1 kibibit 210 bits 1 024 bits the kibibit has existed since 1998 and is closely related to the kilobit which is equal to 103 bits 1 000 bits however a kilobyte is 1 024 bytes the binary prefixes form part of the international system of quantities isq
the kibibyte is a multiple of the unit byte for quantities of digital information the binary prefix kibi means 210 or 1024 therefore 1 kibibyte is 1024 bytes the unit symbol for the kibibyte is kib the unit was established by the international electrotechnical commission iec in 1998 has been accepted for use by all major standards organizations and is part of the international system of quantities the kibibyte was designed to replace the kilobyte in those computer science contexts in which the term kilobyte is used to mean 1024 bytes the interpretation of the older term kilobyte to denote 1024 bytes conflicting with the si definition of the prefix kilo 1000 is still common mostly in informal computer science contexts
the attempted kidnapping of kalaniʻōpuʻu by captain james cook and the decision to hold the ruling chief of the island of hawaii in exchange for their stolen long boat lifeboat was a fatal error on the part of the british navigator and the main cause of his death his arrival in hawaii was followed by mass migrations of europeans and americans to the islands that ended with the overthrow of the kingdom of hawaii the original native monarchy of the islands
kidney cancer also known as renal cancer is a type of cancer that starts in the cells in the kidney the two most common types of kidney cancer are renal cell carcinoma rcc and transitional cell carcinoma tcc also known as urothelial cell carcinoma of the renal pelvis these names reflect the type of cell from which the cancer developed the different types of kidney cancer such as rcc and ucc develop in different ways meaning that the diseases have different long term outcomes and need to be staged and treated in different ways rcc is responsible for approximately 80 of primary renal cancers and ucc accounts the majority of the remainder overall five year survival rate in the united states is 73 for cancers that are confined to the kidney the five year survival rate is 92 if it has spread to the surrounding lymph nodes it is 65 and if has metastasized it is 12
kidney disease also known as nephropathy or renal disease is damage to or disease of a kidney nephritis is inflammatory kidney disease nephrosis is noninflammatory nephropathy kidney disease usually causes kidney failure renal failure to more or less degree with the amount depending on the type of disease in precise usage disease denotes the structural and etiologic disease entity whereas failure denotes the dysfunction lack of working well that is impaired renal function but in common usage these meanings overlap for example the terms chronic kidney disease and chronic renal failure are usually considered synonymous acute kidney disease has often been called acute renal failure although nephrologists now often tend to call it acute kidney injury about 1 in 8 americans suffer from chronic kidney disease
kidney failure also known as renal failure or renal insufficiency is a medical condition of impaired kidney function in which the kidneys fail to adequately filter metabolic wastes from the blood the two main forms are acute kidney injury which is often reversible with adequate treatment and chronic kidney disease which is often not reversible in both cases there is usually an underlying cause kidney failure is mainly determined by a decrease in glomerular filtration rate which is the rate at which blood is filtered in the glomeruli of the kidney the condition is detected by a decrease in or absence of urine production or determination of waste products creatinine or urea in the blood depending on the cause hematuria blood loss in the urine and proteinuria protein loss in the urine may be noted in kidney failure there may be problems with increased fluid in the body leading to swelling increased acid levels raised levels of potassium decreased levels of calcium increased levels of phosphate and in later stages anemia bone health may also be affected long term kidney problems are associated with an increased risk of cardiovascular disease
kidney stone disease also known as urolithiasis is when a solid piece of material kidney stone occurs in the urinary tract kidney stones typically form in the kidney and leave the body in the urine stream a small stone may pass without causing symptoms if a stone grows to more than 5 millimeters 0 2 in it can cause blockage of the ureter resulting in severe pain in the lower back or abdomen a stone may also result in blood in the urine vomiting or painful urination about half of people will have another stone within ten years most stones form due to a combination of genetics and environmental factors risk factors include high urine calcium levels obesity certain foods some medications calcium supplements hyperparathyroidism gout and not drinking enough fluids stones form in the kidney when minerals in urine are at high concentration the diagnosis is usually based on symptoms urine testing and medical imaging blood tests may also be useful stones are typically classified by their location nephrolithiasis in the kidney ureterolithiasis in the ureter cystolithiasis in the bladder or by what they are made of calcium uric acid struvite cystine in those who have had stones prevention is by drinking fluids such that more than two liters of urine is produced per day if this is not effective enough thiazide diuretic citrate or allopurinol may be taken it is recommended that soft drinks containing phosphoric acid typically colas be avoided when a stone causes no symptoms no treatment is needed otherwise pain control is usually the first measure using medications such as nonsteroidal anti inflammatory drugs or opioids larger stones may require procedures such as extracorporeal shock wave lithotripsy ureteroscopy or percutaneous nephrolithotomy between 1 and 15 of people globally are affected by kidney stones at some point in their life in 2013 49 million cases occurred resulting in about 15 000 deaths they have become more common in the western world since the 1970 s generally more men are affected than women kidney stones have affected humans throughout history with descriptions of surgery to remove them dating from as early as 600 bc
kidney transplantation or renal transplantation is the organ transplant of a kidney into a patient with end stage renal disease kidney transplantation is typically classified as deceased donor formerly known as cadaveric or living donor transplantation depending on the source of the donor organ living donor renal transplants are further characterized as genetically related living related or non related living unrelated transplants depending on whether a biological relationship exists between the donor and recipient exchanges and chains are a novel approach to expand the living donor pool in february 2012 this novel approach to expand the living donor pool was featured on the front page of the new york times in a story covering the largest chain in the world involving 60 participants organized by the national kidney registry in 2014 the record for the largest chain was broken again by a swap involving 70 participants covered by abc news
kidney tumours or kidney tumors also known as renal tumours are tumours or growths on or in the kidney these growths can be benign or malignant cancerous they may be discovered on medical imaging incidentally i e an incidentaloma or may be present in patients as an abdominal mass hematuria abdominal pain or manifest first in a paraneoplastic syndrome that seems unrelated to the kidney
kienböck s disease is a disorder of the wrist it is named for dr robert kienböck a radiologist in vienna austria who described osteomalacia of the lunate in 1910 it is breakdown of the lunate bone a carpal bone in the wrist that articulates with the radius in the forearm specifically kienböck s disease is another name for avascular necrosis death and fracture of bone tissue due to interruption of blood supply with fragmentation and collapse of the lunate this has classically been attributed to arterial disruption but may also occur after events that produce venous congestion with elevated interosseous pressure
kikuchi disease or kikuchi fujimoto disease was described in 1972 in japan it is also known as histiocytic necrotizing lymphadenitis kikuchi necrotizing lymphadenitis phagocytic necrotizing lymphadenitis subacute necrotizing lymphadenitis and necrotizing lymphadenitis it was first described by dr masahiro kikuchi 1935 – 2012 in 1972 and independently by y fujimoto
killafornia is first blood s first full length release it was released in 2006 by trustkill records
a killian – jamieson diverticulum is an outpouching of the esophagus just below the upper esophageal sphincter the physicians that first discovered the diverticulum were gustav killian and james jamieson diverticula are seldom larger than 1 5 cm and are less frequent than the similar zenker s diverticula as opposed to a zenker s which is typically a posterior and inferior outpouching from the esophagus a killian – jamieson diverticulum is typically an anterolateral outpouching at the level of the c 5 c 6 vertebral bodies due to a congenital weakness in the cervical esophagus just below the cricopharyngeal muscle it is usually smaller in size than a zenker s diverticulum and typically asymptomatic although congenital it is more commonly seen in elderly patients
the kilobit is a multiple of the unit bit for digital information or computer storage the prefix kilo symbol k is defined in the international system of units si as a multiplier of 103 1 thousand and therefore 1 kilobit 103 bits 1000 bits the kilobit has the unit symbol kbit or kb using the common byte size of 8 bits 1 kbit is equal to 125 bytes the kilobit is most commonly used in the expression of data rates of digital communication circuits as kilobits per second kbit s or kb s or abbreviated as kbps as in for example a 56 kbps pstn circuit or a 512 kbit s broadband internet connection the unit symbol kb is typographically similar to unit symbols of the kilobyte i e kb with an upper case b the international electrotechnical commission iec therefore recommends the symbol bit instead of b the prefix kilo is often used in fields of computer science and information technology with a meaning of multiplication by 1024 instead of 1000 contrary to international standards in conjunction with the base unit byte and bit in which case it is to be written as ki with a capital letter k e g 1 kibit 1024 bits the decimal si definition 1 kbit s 1000 bit s is used uniformly in the context of telecommunication transmission speeds the kilobit is closely related to the much less used kibibit a unit multiple derived from the binary prefix kibi symbol ki of the same order of magnitude which is equal to 210 bits 1024 bits or approximately 2 larger than the kilobit despite the definitions of these new prefixes meant for binary based quantities of storage only not data rates by international standards organizations memory semiconductor chips are still marketed using the metric prefix names to designate binary multiples
the kilobyte is a multiple of the unit byte for digital information the international system of units si defines the prefix kilo as 1000 103 therefore one kilobyte is 1000 bytes the unit symbol for the kilobyte is kb in information technology particularly in reference to main memory capacity kilobyte is traditionally used to denote 1024 210 bytes this arises from the powers of two sizing common to such memory in digital circuitry in this context the symbols k and kb are often used when 1024 bytes is meant
kimura s disease is a benign rare chronic inflammatory disorder its primary symptoms are subdermal lesions in the head or neck or painless unilateral inflammation of cervical lymph nodes
kindler syndrome also known as bullous acrokeratotic poikiloderma of kindler and weary congenital poikiloderma with blisters and keratoses congenital poikiloderma with bullae and progressive cutaneous atrophy hereditary acrokeratotic poikiloderma hyperkeratosis – hyperpigmentation syndrome acrokeratotic poikiloderma and weary – kindler syndrome is a rare congenital disease of the skin caused by a mutation in the kind 1 gene
kindness priming is an affect dependent cognitive effect in which subjects will display a positive affect following exposure to kindness
kinesia paradoxa is a phenomenon most often seen in people with parkinson s disease where individuals who typically experience severe difficulties with the simple movements may perform complex movements easily specifically kinesia paradoxa focuses on walking referring to the sudden ability to demonstrate smooth fluid movements in people that previously had problems with walking easily this new discovery does not just happen to an individual randomly but must be stimulated using various types of visual or auditory cues this phenomenon is generally stimulated to help improve the mobility of people with akinesia akinesia consists of changes in walking pattern freezing of gait fog and losses of balance lobs fog occurs in the middle of stride cutting off walking and making it fairly difficult for a person to re initiate a movement kinesia paradoxa can be used as a management strategy to overcome this lobs are when a person has difficulty maintaining an upright position and lose their balance eventually leading to them falling since parkinson ’ s disease is a progressive disease patient ’ s symptoms continue to worsen with time and they often develop visible differences in their walking that greatly affects their quality of life these differences include shuffling of steps decreased stride length and decrease in overall movement kinesia paradoxa is not able to be stimulated in everyone with movement disorders persons who can stimulate this phenomenon demonstrate visible improvements in mobility including increased stride length more fluidity in strides less fogs incidents less lobs and those that appeared to be completely frozen previously can regain their movement more recently kinesia paradoxa is also being used to treat children with asperger s syndrome children with asperger s demonstrate excellent skills in drawing modeling building and computer games but often struggle with everyday motor tasks such as walking or catching a ball kinesia paradoxa is currently being explored to help aid these individuals in focusing their attention and improving their efficiency in these simple motor tasks
kinetic inductance is the manifestation of the inertial mass of mobile charge carriers in alternating electric fields as an equivalent series inductance kinetic inductance is observed in high carrier mobility conductors e g superconductors and at very high frequencies
kinking hair also known as acquired progressive kinking is a condition primarily reposted in postpubescent males with androgenetic alopecia presenting with gradual curling and darkening of the frontal temporal auricular and vertex hairs which under the microscope show kinks and twists with or without longitudinal grooving
in robotics and motion planning kinodynamic planning is a class of problems for which velocity acceleration and force torque bounds must be satisfied together with kinematic constraints such as avoiding obstacles the term was coined by bruce donald pat xavier john canny and john reif donald et al developed the first polynomial time approximation schemes ptas for the problem by providing a provably polynomial time ε approximation algorithm they resolved a long standing open problem in optimal control their first paper considered time optimal control fastest path of a point mass under newtonian dynamics amidst polygonal 2 d or polyhedral 3 d obstacles subject to state bounds on position velocity and acceleration later they extended the technique to many other cases for example to 3 d open chain kinematic robots under full lagrangian dynamics more recently many practical heuristic algorithms based on stochastic optimization and iterative sampling were developed by a wide range of authors to address the kinodynamic planning problem these techniques for kinodynamic planning have been shown to work well in practice however none of these heuristic techniques can guarantee the optimality of the computed solution i e they have no performance guarantees and none can be mathematically proven to be faster than the original ptas algorithms i e none have a provably lower computational complexity
kirkman s schoolgirl problem is a problem in combinatorics proposed by rev thomas penyngton kirkman in 1850 as query vi in the lady s and gentleman s diary pg 48 the problem states fifteen young ladies in a school walk out three abreast for seven days in succession it is required to arrange them daily so that no two shall walk twice abreast
kiwiana are certain items and icons from new zealand s heritage especially from around the middle of the 20 th century that are seen as representing iconic kiwi elements these quirky things that contribute to a sense of nationhood include both genuine cultural icons and kitsch
dominant optic atrophy or dominant optic atrophy kjer s type is an autosomally inherited disease that affects the optic nerves causing reduced visual acuity and blindness beginning in childhood this condition is due to mitochondrial dysfunction mediating the death of optic nerve fibers dominant optic atrophy was first described clinically by batten in 1896 and named kjer ’ s optic neuropathy in 1959 after danish ophthalmologist poul kjer who studied 19 families with the disease although dominant optic atrophy is the most common autosomally inherited optic neuropathy i e disease of the optic nerves aside from glaucoma it is often misdiagnosed
a klatskin tumor or hilar cholangiocarcinoma is a cholangiocarcinoma cancer of the biliary tree occurring at the confluence of the right and left hepatic bile ducts it is named after dr gerald klatskin
klebsiella pneumonia is a form of bacterial pneumonia associated with klebsiella pneumoniae it is typically due to aspiration by alcoholics though it is more commonly implicated in hospital acquired urinary tract and wound infections particularly in immunocompromised individuals and diabetics
in computational geometry klee s measure problem is the problem of determining how efficiently the measure of a union of multidimensional rectangular ranges can be computed here a d dimensional rectangular range is defined to be a cartesian product of d intervals of real numbers which is a subset of rd the problem is named after victor klee who gave an algorithm for computing the length of a union of intervals the case d 1 which was later shown to be optimally efficient in the sense of computational complexity theory the computational complexity of computing the area of a union of 2 dimensional rectangular ranges is now also known but the case d ≥ 3 remains an open problem
kleine – levin syndrome kls also known as sleeping beauty syndrome is a rare sleep disorder characterized by persistent episodic hypersomnia and cognitive or mood changes many patients also experience hyperphagia hypersexuality and other symptoms patients generally experience recurrent episodes of the condition for more than a decade individual episodes generally last more than a week but less than a month the condition greatly affects the personal professional and social lives of sufferers but symptoms spontaneously resolve and seldom cause permanent issues the severity of symptoms and the course of the syndrome vary between sufferers patients commonly have about 20 episodes over about a decade several months generally elapse between episodes the onset of the condition usually follows a viral infection several different viruses have been observed to trigger kls it is generally only diagnosed after similar conditions have been excluded mri ct scans lumbar puncture and toxicology tests are used to rule out other possibilities the syndrome s mechanism is not known but the thalamus is thought to possibly play a role tomography has shown hypoperfusion in the brains of patients during episodes kls is very rare occurring at a rate of one in a million which limits research into genetic factors the condition primarily affects adolescent males although also patients are female and the age of onset varies there is no known cure and there is little evidence supporting drug treatment lithium has been reported to have limited effects in case reports decreasing the length of episodes and duration between them in some patients stimulants have been shown to promote wakefulness during episodes but they do not counteract cognitive symptoms or decrease the duration of episodes the condition is named after willi kleine and max levin who described cases of the disease in the early 20 th century it was added to the international classification of sleep disorders in 1990
kleptomania or klopemania is the inability to refrain from the urge to steal items and is done for reasons other than personal use or financial gain first described in 1816 kleptomania is classified in psychiatry as an impulse control disorder alternatively some of the main characteristics of the disorder which consist of recurring intrusion feelings an inability to resist the urge to steal and a release of pressure following the theft suggest that kleptomania could be an obsessive compulsive spectrum disorder although this is disputed the disorder is frequently under diagnosed and is regularly associated with other psychiatric disorders particularly anxiety and eating disorders and alcohol and substance abuse patients with kleptomania are typically treated with therapies in other areas due to the comorbid grievances rather than issues directly related to kleptomania over the last 100 years a shift from psychotherapeutic to psychopharmacological interventions for kleptomania has occurred pharmacological treatments using selective serotonin reuptake inhibitors ssris mood stabilizers and opioid receptor antagonists and other antidepressants along with cognitive behavioral therapy have yielded positive results
kleptoplasty or kleptoplastidy is a symbiotic phenomenon whereby plastids notably chloroplasts from algae are sequestered by host organisms the word is derived from kleptes κλέπτης which is greek for thief the alga is eaten normally and partially digested leaving the plastid intact the plastids are maintained within the host temporarily continuing photosynthesis and benefiting the predator the term was coined in 1990 to describe chloroplast symbiosis
klinefelter syndrome ks also known as 47 xxy or xxy is the set of symptoms that result from two or more x chromosomes in males the primary feature is sterility often symptoms may be subtle and many people do not realize they are affected sometimes symptoms are more prominent and may include weaker muscles greater height poor coordination less body hair smaller genitals breast growth and less interest in sex often it is only at puberty that these symptoms are noticed intelligence is usually normal however reading difficulties and problems with speech are more common symptoms are typically more severe if three or more x chromosomes are present klinefelter syndrome usually occurs randomly an older mother might increase the risk slightly the condition is not inherited from one s parents the underlying mechanisms involves at least one extra x chromosome in addition to a y chromosome such that there is a total of 47 or more chromosomes rather than usual 46 ks is diagnosed by the genetic test known as a karyotype while there is no cure a number of treatments may help physical therapy speech and language therapy counselling and adjustments of teaching methods may be useful testosterone replacement may be used in those who have significantly low levels enlarged breasts may be removed by surgery about half of males affected with the help of assisted reproductive technology have a chance of having children however this is expensive and carries risks males appear to have a higher risk of breast cancer than typical but still lower than that of females the condition has a nearly normal life expectancy klinefelter syndrome is one of the most common chromosomal disorders occurring in 1 500 to 1 1000 live male births it is named after harry klinefelter who identified the condition in the 1940 s 1956 saw the identification of the extra x chromosome mice can also have the xxy syndrome making them a useful research model
klippel – feil syndrome is a rare disease initially reported in 1884 by maurice klippel and andré feil from france characterized by the congenital fusion of any two of the seven cervical vertebrae the syndrome occurs in a heterogeneous group of patients unified only by the presence of a congenital defect in the formation or segmentation of the cervical spine klippel feil results in limited movement of the neck klippel – feil syndrome is sometimes identified by shortness of the neck but not all people with this disorder have a visibly shortened neck some people with the syndrome have a very low hairline in 1919 andré feil in his phd thesis suggested another classification of the syndrome encompassing not only deformation of the cervical spine but also deformation of the lumbar and thoracic spine
klippel – trénaunay syndrome kts or kt formerly klippel – trénaunay – weber syndrome and sometimes angioosteohypertrophy syndrome and hemangiectatic hypertrophy is a rare congenital medical condition in which blood vessels and or lymph vessels fail to form properly the three main features are nevus flammeus port wine stain venous and lymphatic malformations and soft tissue hypertrophy of the affected limb it is similar to though distinctly separate from the less common parkes weber syndrome
klumpke s paralysis or klumpke s palsy or dejerine – klumpke palsy is a variety of partial palsy of the lower roots of the brachial plexus the brachial plexus is a network of spinal nerves that originates in the back of the neck extends through the axilla armpit and gives rise to nerves to the upper limb see picture click to enlarge it is named after augusta déjerine klumpke
klüver – bucy syndrome is a syndrome resulting from bilateral lesions of the medial temporal lobe including amygdaloid nucleus klüver – bucy syndrome may present with hyperphagia hypersexuality hyperorality visual agnosia and docility
the knapsack problem or rucksack problem is a problem in combinatorial optimization given a set of items each with a weight and a value determine the number of each item to include in a collection so that the total weight is less than or equal to a given limit and the total value is as large as possible it derives its name from the problem faced by someone who is constrained by a fixed size knapsack and must fill it with the most valuable items the problem often arises in resource allocation where there are financial constraints and is studied in fields such as combinatorics computer science complexity theory cryptography applied mathematics and daily fantasy sports the knapsack problem has been studied for more than a century with early works dating as far back as 1897 the name knapsack problem dates back to the early works of mathematician tobias dantzig 1884 – 1956 and refers to the commonplace problem of packing your most valuable or useful items without overloading your luggage
arthritis is inflammation in the joints or area of the body where two bones come together joints are responsible for the movement of body parts it is a condition that can be experienced all over the body or in a specific area the types range from those related to wear and tear of cartilage such as osteoarthritis to those associated with inflammation resulting from an overactive immune system such as rheumatoid arthritis the one part of the body that is most affected by arthritis is the knee and it can suffer from both rheumatoid or osteoarthritis
knee pain is a common complaint for many people there are several factors that can cause knee pain awareness and knowledge of the causes of knee pain lead to a more accurate diagnosis management of knee pain is in the accurate diagnosis and effective treatment for that diagnosis knee pain can be either referred pain or related to the knee joint itself
knobloch syndrome is a rare genetic disorder presenting severe eyesight problems and often a defect in the skull a usual occurrence is a degeneration of the vitreous humour and the retina two components of the eye this breakdown often results in the separation of the retina the light sensitive tissue at the back of the eye from the eye called retinal detachment which can be recurrent extreme myopia near sightedness is a common feature knobloch syndrome is caused by mutations in an autosomal recessive inherited gene these mutations have been found in the col 18 a 1 gene that instructs for the formation of a protein that builds collagen xviii this type of collagen is found in the basement membranes of various body tissues its deficiency in the eye is thought to be responsible for affecting normal eye development there are three types of knobloch syndrome when caused by mutations in the col 18 a 1 gene it is called knobloch syndrome type 1 the genes causing types ii and iii have yet to be identified knobloch syndrome is also characterised by cataracts dislocated lens with skull defects such as occipital encephalocele and occipital aplasia encephalocele is a neural tube defect where the skull has not completely closed and sac like protrusions of the brain can push through the skull it can also result from other causes in knobloch ’ s syndrome this is usually seen in the occipital region and aplasia is the underdevelopment of tissue again in this reference in the occipital area it is named after knobloch who first described the syndrome in 1971
the knoevenagel condensation reaction is an organic reaction named after emil knoevenagel it is a modification of the aldol condensation a knoevenagel condensation is a nucleophilic addition of an active hydrogen compound to a carbonyl group followed by a dehydration reaction in which a molecule of water is eliminated hence condensation the product is often an αβ unsaturated ketone a conjugated enone general knoevenagel layout in this reaction the carbonyl group is an aldehyde or a ketone the catalyst is usually a weakly basic amine the active hydrogen component has the form z – ch 2 z or z – chr – z for instance diethyl malonate meldrum s acid ethyl acetoacetate or malonic acid or cyanoacetic acid z – chr 1 r 2 for instance nitromethane where z is an electron withdrawing functional group z must be powerful enough to facilitate deprotonation to the enolate ion even with a mild base using a strong base in this reaction would induce self condensation of the aldehyde or ketone the hantzsch pyridine synthesis the gewald reaction and the feist – benary furan synthesis all contain a knoevenagel reaction step the reaction also led to the discovery of cs gas
the knorr quinoline synthesis is an intramolecular organic reaction converting a β ketoanilide to a 2 hydroxyquinoline using sulfuric acid this reaction was first described by ludwig knorr 1859 – 1921 in 1886 knorr quinoline synthesis the reaction is a type of electrophilic aromatic substitution accompanied by elimination of water a 1964 study found that with certain reaction conditions formation of a 4 hydroxyquinoline is a competing reaction for instance the compound benzoylacetanilide 1 forms the 2 hydroxyquinoline 2 in a large excess of polyphosphoric acid ppa but 4 hydroxyquinoline 3 when the amount of ppa is small a reaction mechanism identified a n o dicationic intermediate a with excess acid capable of ring closing and a monocationic intermediate b which fragments to aniline and ultimately to acetophenone aniline reacts with another equivalent of benzoylacetanilide before forming the 4 hydroxyquinoline staskun 1964 knorr cyclization reaction mechanism a 2007 study revised the reaction mechanism and based on nmr spectroscopy and theoretical calculations favors an o o dicationic intermediate a superelectrophile over the n o dicationic intermediate for preparative purposes triflic acid is recommended knorr cyclization with triflic acid sai 2007
knowledge of human nature is the ability to correctly assess the behavior or character of people based on a first impression and to gauge how they think and predict how they will act life experience intuition intelligence and wisdom are the decisive factors which contribute to this ability knowledge of human nature is not innate but is acquired through frequent contact with people and experience with many different people knowledge of human nature can be used to judge people correctly to motivate them to give other people good advice to deepen relationships etc however it can also be used to exploit people to one s own advantage for example if one wants to persuade people to seduce them or to sell them something there are numerous models for the theoretical acquisition of knowledge of human nature such as the myers briggs type indicator or the enneagram
in organizational theory knowledge transfer is the practical problem of transferring knowledge from one part of the organization to another like knowledge management knowledge transfer seeks to organize create capture or distribute knowledge and ensure its availability for future users it is considered to be more than just a communication problem if it were merely that then a memorandum an e mail or a meeting would accomplish the knowledge transfer knowledge transfer is more complex because knowledge resides in organizational members tools tasks and their subnetworks and much knowledge in organizations is tacit or hard to articulate the subject has been taken up under the title of knowledge management since the 1990 s
knuckle pads also known as heloderma meaning similar to the skin of the gila monster lizard for which it is named are circumscribed keratotic fibrous growths over the dorsa of the interphalangeal joints knuckle pads are well defined round plaque like fibrous thickening that may develop at any age and grow to be 10 to 15 mm in diameter in the course of a few weeks or months then go away over time knuckle pads are sometimes associated with dupuytren s contracture and camptodactyly and histologically the lesions are fibromas knuckle pads are generally non responsive to treatment including corticosteroids and tend to recur after surgery however there has been some effectiveness with intralesional fluorouracil
the koch reaction is an organic reaction for the synthesis of tertiary carboxylic acids from alcohols or alkenes the reaction is a strongly acid catalyzed carbonylation using carbon monoxide and typically occurs at high pressures ranging from 50 to 5 000 kpa often requiring temperatures several hundred degrees higher than room temperature generally the reaction is conducted with strong mineral acids such as sulfuric acid hf or bf 3 large scale operations for the fine chemical industry produce almost 150 000 tonnes of koch acids and their derivatives annually but also generate a great deal of waste motivating ongoing attempts to use metal solid acid and other novel catalysts to enable the use of milder reaction conditions formic acid which readily decomposes to carbon monoxide in the presence of acids or relatively low heat is often used instead of carbon monoxide directly this procedure was developed shortly after the koch reaction and is more commonly referred to as the koch haaf reaction and allows for reactions at nearly standard room temperature and pressure some commonly industrially produced koch acids include pivalic acid 2 2 dimethylbutyric acid and 2 2 dimethylpentanoic acid the koch reaction
the kochi reaction is an organic reaction for the decarboxylation of carboxylic acids to alkyl halides with lead tetraacetate and a lithium chloride or other lithium salts the reaction is a variation of the hunsdiecker reaction
koenen s tumor also known as koenen s periungual fibroma and periungual fibroma is a cutaneous condition that results in fifty percent of tuberous sclerosis cases it can be subungual too
in mathematics the koenigs function is a function arising in complex analysis and dynamical systems introduced in 1884 by the french mathematician gabriel koenigs it gives a canonical representation as dilations of a univalent holomorphic mapping or a semigroup of mappings of the unit disk in the complex numbers into itself
the koenigs – knorr reaction in organic chemistry is the substitution reaction of a glycosyl halide with an alcohol to give a glycoside it is one of the oldest and simplest glycosylation reactions it is named after wilhelm koenigs 1851 – 1906 student of von bayer and fellow student with hermann emil fischer and edward knorr student of koenigs koenigs knorr synthesis in its original form koenigs and knorr treated acetobromoglucose with alcohols in the presence of silver carbonate shortly afterwards fischer and armstrong reported very similar findings in the above example the stereochemical outcome is determined by the presence of the neighboring group at c 2 that lends anchimeric assistance resulting in the formation of a 1 2 trans stereochemical arrangement esters e g acetyl benzoyl pivalyl generally provide good anchimeric assistance whereas ethers e g benzyl methyl etc do not leading to mixtures of stereoisomers generally the koenigs – knorr reaction refers to the use of glycosyl chlorides bromides and more recently iodides as glycosyl donors the koenigs – knorr reaction can be performed with alternative promoters such as various heavy metal salts including mercuric bromide mercuric oxide mercuric cyanide and silver triflate when mercury salts are used the reaction is normally called the helferich method other glycosidation methods are fischer glycosidation use of glycosyl acetates thioglycosides glycosyl trichloroacetimidates glycosyl fluorides or n pentenyl glycosides as glycosyl donors or intramolecular aglycon delivery the mechanism for this reaction proceeds through release of a silver halide and is displayed on the german page in full detail
kohlschütter tönz syndrome kts also called amelo cerebro hypohidrotic syndrome is a rare inherited syndrome characterized by epilepsy dementia intellectual disability and yellow teeth caused by amelogenesis imperfecta abnormal formation of tooth enamel it is a type a ectodermal dysplasia it is autosomal recessive and symptoms appear in early childhood the syndrome was first described in 1974 by alfried kohlschütter and colleagues only 24 affected individuals are known as of 2012 the disease has not been connected to any other known epileptic syndromes some but not all cases are associated with mutations in a gene called rogdi another gene that has been associated with this condition is the scl 13 a 5 gene diagnoses of this syndrome have occurred in switzerland sicily the northern israel druze community as well as some other parts of western europe
koilonychia from the greek koilos hollow onikh nail also known as spoon nails is a nail disease that can be a sign of hypochromic anemia especially iron deficiency anemia it refers to abnormally thin nails usually of the hand which have lost their convexity becoming flat or even concave in shape in a sense koilonychia is the opposite of nail clubbing in early stages nails may be brittle and chip or breakeasily koilonychia is associated with plummer vinson syndrome and iron deficiency anemia
the kolbe electrolysis or kolbe reaction is an organic reaction named after hermann kolbe the kolbe reaction is formally a decarboxylative dimerisation of two carboxylic acids or carboxylate ions the overall general reaction is file electrólisis de kolbe png if a mixture of two different carboxylates are used all combinations of them are generally seen as the organic product structures 3 r 1 coo − 3 r 2 coo − → r 1 − r 1 r 1 − r 2 r 2 − r 2 6 co 2 6 e − the reaction mechanism involves a two stage radical process electrochemical decarboxylation gives a radical intermediate then two such intermediates combine to form a covalent bond as an example electrolysis of acetic acid yields ethane and carbon dioxide ch 3 cooh → ch 3 coo − → ch 3 coo · → ch 3 · co 2 2 ch 3 · → ch 3 ch 3 another example is the synthesis of 2 7 dimethyl 2 7 dinitrooctane from 4 methyl 4 nitrovaleric acid kolbe electrolysis synthesis of 2 7 dimethyl 2 7 dinitrooctane
the kolbe – schmitt reaction or kolbe process named after hermann kolbe and rudolf schmitt is a carboxylation chemical reaction that proceeds by heating sodium phenoxide the sodium salt of phenol with carbon dioxide under pressure 100 atm 125 ° c then treating the product with sulfuric acid the final product is an aromatic hydroxy acid which is also known as salicylic acid the precursor to aspirin the kolbe – schmitt reaction by using potassium hydroxide 4 hydroxybenzoic acid is accessible an important precursor for the versatile paraben class of biocides used e g in personal care products
konghanzheng simplified chinese 恐韩症 traditional chinese 恐韓症 pinyin kǒng hán zhèng korean 공한증 or koreaphobia a term coined by chinese football fans was a chinese persistent phenomenon where the china pr national football team has played 28 matches against the korea republic national football team since 1978 but never been able to beat them until the streak ended on 10 february 2010 when korea was beaten 3 – 0 in the 2010 east asian football championship final competition
chutes kongou also called the koungou falls is a massive cataract about 3 2 kilometres wide and up to 56 m tall located in ivindo national park in eastern gabon it is located on the ivindo river and is one of the strongest flowing waterfalls in the world with an average flow of 900 cubic metres per second it is reputed to be the most beautiful waterfall in central africa this part of the ivindo river is a major centre of fish biodiversity the falls are within ivindo national park created in 2002 to protect among other things this beautiful and biologically diverse stretch of river on 14 september 2007 president omar bongo ondimba of gabon confirmed that a dam would be built at the falls to provide electricity to a large iron mining project in belinga further north the iron mine is essentially for gabon s economic development but the dam will inundate a large part of the national park and have a serious impact on local livelihoods old studies indicate that there are other sites on the river where a dam would be easier to build and the environmental and social impacts would be much less than at kongou but no environmental impact assessment was done before the decision was made the decision put into question the president s strategy of developing ecotourism in gabon and may well deter investors and tourists alike it is claimed that the construction of the dam with no prior environmental impact study or proper consultation was a sign of the growing power of the minister of mines and petrol at a time when president bongo s power was declining due to opposition from the gabonese people this project has been stopped
konzo is an epidemic paralytic disease occurring in outbreaks in remote rural areas of low income african countries the people of these regions have been associated with several weeks of almost exclusive consumption of insufficiently processed bitter high cyanide cassava manihot esculenta — a perennial crop native to amazonia in south america but widely cultivated in tropical regions worldwide it is the third most important food source in the tropics after rice and maize and is the staple food of tropical africa cassava yields well in poor soils is drought resistant and the roots give food security during droughts and famine nutritionally the starchy roots are complemented by consumption of cassava leaves which are rich in proteins and vitamins konzo was first described by giovanni trolli in 1938 who compiled the observations from eight doctors working in the kwango area of the belgian congo now democratic republic of the congo
the kornblum oxidation named after nathan kornblum is a chemical reaction of a primary halide with dimethyl sulfoxide dmso to form an aldehyde the kornblum oxidation
the kornblum – delamare rearrangement is a rearrangement reaction in organic chemistry in which a primary or secondary organic peroxide is converted to the corresponding ketone and alcohol under base catalysis the reaction is relevant as a tool in organic synthesis and is a key step in the biosynthesis of prostaglandins kornblum – delamare rearrangement overview the base can be a hydroxide such as potassium hydroxide or an amine such as triethylamine
koro is a culture specific syndrome delusional disorder in which an individual has an overpowering belief that one s genitalia are retracting and will disappear despite the lack of any true longstanding changes to the genitals koro is also known as shrinking penis and it is listed in the diagnostic and statistical manual of mental disorders the syndrome occurs worldwide and mass hysteria of genital shrinkage anxiety has a history in africa asia and europe in the united states and europe the syndrome is commonly known as genital retraction syndrome the condition can be diagnosed through psychological assessment along with physical examination to rule out genuine disorders of the genitalia that could be causing true retraction
korsakoff s syndrome is a manifestation of wernicke s encephalopathy also called wernicke s disease it happens in wernicke s disease in almost all alcohol abusers it is rare among the other patients but for example some cases have been observed after bariatric surgeries when deficiency was not prevented by use of nutritional supplements this neurological disorder is caused by a lack of thiamine vitamin b 1 in the brain and is also often exacerbated by the neurotoxic effects of alcohol when wernicke s encephalopathy accompanies korsakoff s syndrome the combination is called the wernicke – korsakoff syndrome korsakoff s is a continuum of wernicke s encephalopathy or disease though a recognized episode of wernicke s is not always obvious the syndrome is named after sergei korsakoff a russian neuropsychiatrist who discovered the syndrome during the late 19 th century
kostmann syndrome is a group of diseases that affect myelopoiesis causing a congenital form of neutropenia severe congenital neutropenia scn usually without other physical malformations scn manifests in infancy with life threatening bacterial infections most cases of scn responds to treatment with granulocyte colony stimulating factor filgrastim which increases the neutrophil count and decreases the severity and frequency of infections although this treatment has significantly improved survival people with scn are at risk of long term complications such as hematopoietic clonal disorders myelodysplastic syndrome acute myeloid leukemia kostmann disease scn 3 the initial subtype recognized was clinically described in 1956 this type has an autosomal recessive inheritance pattern whereas the most common subtype of kostmann syndrome scn 1 shows autosomal dominant inheritance
the kowalski ester homologation is a chemical reaction for the homologation of esters the kowalski ester homologation this reaction was designed as a safer alternative to the arndt – eistert synthesis avoiding the need for diazomethane the kowalski reaction is named after its inventor conrad j kowalski
krabbe disease also known as globoid cell leukodystrophy or galactosylceramide lipidosis is a rare often fatal degenerative disorder that affects the myelin sheath of the nervous system it is a form of sphingolipidosis as it involves dysfunctional metabolism of sphingolipids this condition is inherited in an autosomal recessive pattern the disease is named after the danish neurologist knud krabbe 1885 – 1965 illinois kentucky and pennsylvania have laws to test for krabbe and other diseases at birth there is a movement in maine and other states to adopt such regulations
the krapcho decarboxylation is the chemical reaction of esters with halide anions the ester must contain an electron withdrawing group in the beta position such as β ketoesters malonic esters α cyanoesters or α sulfonylesters it works best with methyl esters since it is an sn 2 reaction at carbon it is driven by the entropy of the overall reaction as the byproducts chloromethane and co 2 are lost as gases the reaction is a useful synthetic procedure to hydrolyze and decarboxylate malonic esters because it only cleaves one of the ester groups the alternative way e g basic hydrolysis destroys both of the ester groups and a subsequent reaction is usually used to regenerate the alkylated ester
kraurosis vulvae is a cutaneous condition characterized by atrophy and shrinkage of the skin of the vagina and vulva often accompanied by a chronic inflammatory reaction in the deeper tissues
krukenberg s spindle is the name given to the pattern formed on the inner surface of the cornea by pigmented iris cells which are deposited as a result of the currents of the aqueous humor the sign was described in 1899 by friedrich ernst krukenberg 1871 1946 who was a german pathologist specialising in ophthalmology
a krukenberg tumor refers to a malignancy in the ovary that metastasized from a primary site classically the gastrointestinal tract although it can arise in other tissues such as the breast gastric adenocarcinoma especially at the pylorus is the most common source krukenberg tumors are often over 80 found in both ovaries consistent with its metastatic nature
krzyzewskiville or k ville for short is a phenomenon that occurs before major men s basketball games at duke university in simplest terms it is the line for undergraduate students wishing to gain access to the designated tenting games it is often mistakenly referred to as a ticket line however there are no student tickets students are admitted from the line an hour and a half before each game krzyzewskiville is named for mike krzyzewski often called coach k the much loved coach who has helped make duke s basketball program one of the best in the nation he has been known to buy pizza for the k ville residents from time to time and has held open forum team meetings with the cameron crazies before games against their arch rival the north carolina tar heels graduate and professional students do not participate in krzyzewskiville as duke s graduate and professional student council operates a separate weekend long campout each september followed by a lottery for a small number of graduate and professional student season tickets
the kröhnke pyridine synthesis is reaction in organic synthesis between α pyridinium methyl ketone salts and α β unsaturated carbonyl compounds used to generate highly functionalized pyridines pyridines occur widely in natural and synthetic products so there is wide interest in routes for their synthesis the method is named after dr fritz kröhnke
kufor – rakeb syndrome is an autosomal recessive disorder it can be associated with atp 13 a 2
kufs disease is one of many diseases categorized under a disorder known as neuronal ceroid lipofuscinosis ncls ncls are broadly described to create problems with vision movement and cognitive function among all ncls diseases kufs is the only one that does not affect vision and although this is a distinguishing factor of kufs ncls are typically differentiated by the age at which they appear in a patient
in organic chemistry the kumada coupling is a type of cross coupling reaction useful for generating carbon – carbon bonds by the reaction of a grignard reagent and an organic halide the procedure uses transition metal catalysts typically nickel or palladium to couple a combination of two alkyl aryl or vinyl groups the groups of robert corriu and makoto kumada reported the reaction independently in 1972 the reaction is notable for being among the first reported catalytic cross coupling methods despite the subsequent development of alternative reactions suzuki sonogashira stille hiyama negishi the kumada coupling continues to be employed in many synthetic applications including the industrial scale production of aliskiren a hypertension medication and polythiophenes useful in organic electronic devices
kunburudhoo dhivehi ކުނބުރުދޫ is a formerly inhabited island of the haa dhaalu atoll administrative division and geographically part of thiladhummathi atoll in the north of the maldives the island is suffering severe land loss to the sea due to coastal erosion during the monsoon the sand is being eroded at a greater rate than it is accreted plans are underway to construct a quayside and artificial reef to protect the island preliminary results from the 2014 population and housing census report that the island of kunburudhoo is no longer inhabited due in part to the threat of rising sea levels the same publication the revised version of which was released by the national bureau of statistics in march 2015 shows a total of 85 maldivian people living on the island in 2006 since the government s consolidation program launched in 2009 the people of kunburudhoo have been relocated to h dh nolhivaranfaru with the people of maavaidhoo and faridhoo of the same atoll
kupyna is a cryptographic hash function defined in the ukrainian national standard dstu 7564 2014 it was created to replace an obsolete gost hash function defined in the old standard gost 34 11 95 similar to streebog hash function standardized in russia in addition to the hash function the standard also describes message authentication code generation using kupyna with digest sizes 256 384 and 512 bits
the kurišková uranium deposit is one of the largest uranium deposits in slovakia the deposit is located in close neighborhoods 6 km of the city of košice in košice region in the area known as jahodná since 2006 the deposit has been explored by european uranium resources formerly known as tournigan energy through its local daughter company ludovika energy with a prospect of future uranium mining however the activity was greeted with resistance of local people the resistance of local inhabitants against uranium mining near košice even led to slovakia s biggest ever environmental petition supported by greenpeace which has been signed by more than 113 000 people and 41 towns and cities all over the country according to ludovika energy kurišková has an estimated annual production capacity of over 1 8 million pounds of ore reserves amounting to 32 55 million pounds of ore grading 0 3865 uranium thus resulting 56 98 tonnes of uranium
in mathematics the kurosh problem is one general problem and several more special questions in ring theory the general problem is known to have a negative solution since one of the special cases has been shown to have counterexamples these matters were brought up by aleksandr gennadievich kurosh as analogues of the burnside problem in group theory kurosh asked whether there can be a finitely generated infinite dimensional algebraic algebra the problem being to show this cannot happen a special case is whether or not every nil algebra is locally nilpotent for pi algebras the kurosh problem has a positive solution golod showed a counterexample to that case as an application of the golod – shafarevich theorem the kurosh problem on group algebras concerns the augmentation ideal i if i is a nil ideal is the group algebra locally nilpotent
kuru is an incurable degenerative neurological disorder endemic to tribal regions of papua new guinea it is a type of transmissible spongiform encephalopathy caused by a prion found in humans the term kuru derives from the fore word kuria or guria to shake a reference to the body tremors that are a classic symptom of the disease it is also known among the fore as the laughing sickness due to the pathologic bursts of laughter people would display when afflicted with the disease it is now widely accepted that kuru was transmitted among members of the fore tribe of papua new guinea via funerary cannibalism
kussmaul breathing is a deep and labored breathing pattern often associated with severe metabolic acidosis particularly diabetic ketoacidosis dka but also kidney failure it is a form of hyperventilation which is any breathing pattern that reduces carbon dioxide in the blood due to increased rate or depth of respiration in metabolic acidosis breathing is first rapid and shallow but as acidosis worsens breathing gradually becomes deep labored and gasping it is this latter type of breathing pattern that is referred to as kussmaul breathing
kwashiorkor kwɑːʃiˈɔːrkər is a form of severe protein – energy malnutrition characterized by edema irritability ulcerating dermatoses and an enlarged liver with fatty infiltrates sufficient calorie intake but with insufficient protein consumption distinguishes it from marasmus kwashiorkor cases occur in areas of famine or poor food supply cases in the developed world are rare jamaican pediatrician cicely williams introduced the name into the medical community in a 1935 lancet article two years after she published the disease s first formal description in the western medical literature the name is derived from the ga language of coastal ghana translated as the sickness the baby gets when the new baby comes or the disease of the deposed child and reflecting the development of the condition in an older child who has been weaned from the breast when a younger sibling comes breast milk contains proteins and amino acids vital to a child s growth in at risk populations kwashiorkor may develop after a mother weans her child from breast milk replacing it with a diet high in carbohydrates especially sugar
kyasanur forest disease kfd is a tick borne viral hemorrhagic fever endemic to south asia the disease is caused by a virus belonging to the family flaviviridae which also includes yellow fever and dengue fever
kyphoscoliosis describes an abnormal curvature of the spine in both a coronal and sagittal plane it is a combination of kyphosis and scoliosis this musculoskeletal disorder often leads to other issues in patients such as under ventilation of lungs pulmonary hypertension difficulty in performing day to day activities psychological issues emanating from anxiety about acceptance among peers especially in young patients it can also be seen in syringomyelia friedreich s ataxia spina bifida and duchenne muscular dystrophy due to asymmetric weakening of the paraspinal muscles
kyphosis from greek κυφός kyphos a hump refers to the abnormally excessive convex kyphotic curvature of the spine as it occurs in the cervical thoracic and sacral regions normal inward concave curving of the cervical and lumbar regions of the spine is called lordosis kyphosis can be called roundback or kelso s hunchback it can result from degenerative diseases such as arthritis developmental problems most commonly scheuermann s disease osteoporosis with compression fractures of the vertebra multiple myeloma or trauma a normal thoracic spine extends from the 1 st to the 12 th vertebra and should have a slight kyphotic angle ranging from 20 ° to 45 ° when the roundness of the upper spine increases past 45 ° it is called kyphosis or hyperkyphosis scheuermann s kyphosis is the most classic form of hyperkyphosis and is the result of wedged vertebrae that develop during adolescence the cause is not currently known and the condition appears to be multifactorial and is seen more frequently in males than females in the sense of a deformity it is the pathological curving of the spine where parts of the spinal column lose some or all of their lordotic profile this causes a bowing of the back seen as a slouching posture while most cases of kyphosis are mild and only require routine monitoring serious cases can be debilitating high degrees of kyphosis can cause severe pain and discomfort breathing and digestion difficulties cardiovascular irregularities neurological compromise and in the more severe cases significantly shortened life spans these types of high end curves typically do not respond well to conservative treatment and almost always warrant spinal fusion surgery which can restore the body s natural degree of curvature the cobb angle is the preferred method of measuring kyphosis
kyrle disease or hyperkeratosis follicularis et parafollicularis in cutem penetrans is identified as a form of an acquired perforating disease other major perforating diseases are elastosis perforans serpiginosa and reactive perforating collagenosis recently however there is a controversy on categorizing kyrle disease with perforating dermatosis or a subtype of acquired perforating collagenosis kyrle disease was first described by josef kyrle in 1916 when a diabetic woman presented generalized hyperkeratotic nodules the disease is distinguished by large papules with central keratin plus on the skin usually on the legs of the patient and is often in conjunction with hepatic renal or diabetic disorders it can affect both females and males with a 6 1 ratio the papules usually show up on the patient with an average age of 30 years kyrle disease is a rare disease unless there is a high count of patients with chronic renal failure the disease seems to be more prevalent in african americans which can be correlated to the high incidence of diabetes mellitus and renal failure in the population
in fluid dynamics a kármán vortex street or a von kármán vortex sheet is a repeating pattern of swirling vortices caused by the unsteady separation of flow of a fluid around blunt bodies it is named after the engineer and fluid dynamicist theodore von kármán and is responsible for such phenomena as the singing of suspended telephone or power lines and the vibration of a car antenna at certain speeds
köhler disease also spelled kohler and referred to in some texts as kohler disease ii is a rare bone disorder of the foot found in children between six and nine years of age the disease typically affects boys but it can also affect girls it was first described in 1908 by alban köhler 1874 – 1947 a german radiologist it is caused when the navicular bone temporarily loses its blood supply as a result tissue in the bone dies and the bone collapses when treated it causes no long term problems in most cases although rarely can return in adults as the navicular bone gets back to normal symptoms typically abate in february 2010 the journal of the american medical association reported that the 19 year old king tutankhamun may well have died of complications from malaria combined with köhler disease ii
könig s syndrome synonym ileocaecal valve syndrome is a syndrome of abdominal pain in relation to meals constipation alternated with diarrhea meteorism gurgling sounds hyper peristalsis on auscultation especially in the right iliac fossa and abdominal distension it is caused by an incomplete obstruction of the small intestine and especially of the ileocecal valve e g in crohn s disease or in rare cases of cancer of the small intestine it is named after the german surgeon franz könig 1832 – 1910 and should not be confused with könig s disease also named after him
in mathematics the köthe conjecture is a problem in ring theory open as of 2010 it is formulated in various ways suppose that r is a ring one way to state the conjecture is that if r has no nil ideal other than 0 then it has no nil one sided ideal other than 0 this question was posed in 1930 by gottfried köthe 1905 – 1989 the köthe conjecture has been shown to be true for various classes of rings such as polynomial identity rings and right noetherian rings but a general solution remains elusive
the küstrin putsch also known as the buchrucker putsch was a reaction to the september 26 1923 quelling of resistance by the german government to the occupation of the ruhr region led by bruno ernst buchrucker groups of the black reichswehr wanted to bring down the reich government of chancellor gustav stresemann and replace the parliamentarian democratic republic with a national dictatorship another motive for the putsch was the reichswehr s decision to disband work details causing many of their members to lose their livelihood the attempt to occupy küstrin a garrison city was prevented by units of the reichswehr buchrucker and other officers were arrested and sentenced for high treason to imprisonment in a fortress or prison the bulk of the rebels were soon released and were not punished for a short time the putsch controlled the citadel and fort hahneberg but were then forced to surrender to the reichswehr
in mathematics an l function is a meromorphic function on the complex plane associated to one out of several categories of mathematical objects an l series is a dirichlet series usually convergent on a half plane that may give rise to an l function via analytic continuation the theory of l functions has become a very substantial and still largely conjectural part of contemporary analytic number theory in it broad generalisations of the riemann zeta function and the l series for a dirichlet character are constructed and their general properties in most cases still out of reach of proof are set out in a systematic way
lcd crosstalk is a visual defect in an lcd screen which occurs because of interference between adjacent pixels owing to the way rows and columns in the display are addressed and charge is pushed around the data on one part of the display has the potential to influence what is displayed elsewhere this is generally known as cross talk and in matrix displays typically occurs in the horizontal and vertical directions cross talk used to be a serious problem in the old passive matrix stn displays but is rarely discernable in modern active matrix tft displays a fortunate side effect of inversion see above is that for most display material what little cross talk there is largely cancelled out for most practical purposes the level of crosstalk in modern lcds is negligible certain patterns particularly those involving fine dots can interact with the inversion and reveal visible cross talk if you try moving a small window in front of the inversion pattern above which makes your screen flicker the most you may well see cross talk in the surrounding pattern different patterns are required to reveal cross talk on different displays depending on their inversion scheme the following patterns may show cross talk on your screen
lgbt cruises are a rising phenomenon in lgbt culture and a growing trend in the lgbt tourism industry
the establishment of lgbt rights in the u s state of connecticut is a recent phenomenon with most advances in lgbt rights taking place in the 21 st century in regard to very liberal lgbt rights connecticut was the second us state to enact two major pieces of pro lgbt legislation the repeal of the sodomy law in 1971 and the legalization of same sex marriage in 2008
the establishment of lgbt rights in the u s state of iowa is a recent phenomenon with most advances in lgbt rights taking place since 2007 iowa began issuing marriage licenses to same sex couples on april 27 2009 following a ruling by the iowa supreme court making iowa the fourth u s state to legalize same sex marriage
the expansion of lgbt rights in the u s state of maryland is a recent phenomenon with most advances in lgbt rights occurring in the 1990 s 2000 s and 2010 s maryland has statewide protections against discrimination based on an individual s sexual orientation since 2001 and gender identity since 2014 legislation to legalize same sex marriage in maryland was approved by voters on november 6 2012 and went into effect on january 1 2013
the establishment of lgbt rights in the u s state of massachusetts is a recent phenomenon with most advances in lgbt rights taking place since 1992 in 2004 it became the first u s state to grant marriage licenses to same sex couples after the decision in goodridge v department of public health
lig 4 syndrome also known as ligase iv syndrome is an extremely rare condition caused by mutations in the dna ligase iv lig 4 gene some mutations in this gene are associated with a resistance against multiple myeloma and severe combined immunodeficiency severity of symptoms depends on the degree of reduced enzymatic activity of ligase iv or gene expression as dna ligase iv is essential in v d j recombination the mechanism by which immunoglobulins b cell and t cell receptors are formed patients with lig 4 syndrome may suffer from less effective or defective v d j recombination some patients have a severe immunodeficiency characterized by pancytopenia causing chronic respiratory infections and sinusitis clinical features also include seckel syndrome like facial abnormalities and microcephaly patients also suffer from growth retardation and skin conditions including photosensitivity psoriasis and telangiectasia although not present in all patients may also present with hypothyroidism and type ii diabetes and possibly malignancies such as acute t cell leukemia the clinical phenotype of lig 4 syndrome closely resembles that of nijmegen breakage syndrome nbs
in the study of algorithms an lp type problem also called a generalized linear program is an optimization problem that shares certain properties with low dimensional linear programs and that may be solved by similar algorithms lp type problems include many important optimization problems that are not themselves linear programs such as the problem of finding the smallest circle containing a given set of planar points they may be solved by a combination of randomized algorithms in an amount of time that is linear in the number of elements defining the problem and subexponential in the dimension of the problem
lrba deficiency is a rare genetic disorder of the immune system this disorder is caused by a mutation in the gene lrba lrba stands for “ lipopolysaccharide lps responsive vesicle trafficking beach and anchor containing ” gene this condition is characterized by autoimmunity lymphoproliferation and immune deficiency it was first described by gabriela lopez herrera from university college london in 2012 investigators in the laboratory of dr michael lenardo at national institute of allergy and infectious diseases the national institutes of health and dr michael jordan at cincinnati children ’ s hospital medical center later described this condition and therapy in 2015
la crosse encephalitis is an encephalitis caused by an arbovirus the la crosse virus which has a mosquito vector ochlerotatus triseriatus synonym aedes triseriatus la crosse encephalitis virus lacv is one of a group of mosquito transmitted viruses that can cause encephalitis or inflammation of the brain lac encephalitis is rare in the united states about 80 – 100 lacv disease cases are reported each year although it is believed to be under reported due to minimal symptoms experienced by many of those affected
la niña lɑːˈniːnjə spanish pronunciation la ˈniɲa is a coupled ocean atmosphere phenomenon that is the counterpart of el niño as part of the broader el niño – southern oscillation climate pattern the name la niña originates from spanish meaning the girl analogous to el niño meaning the boy it has also in the past been called anti el niño and el viejo meaning the old man during a period of la niña the sea surface temperature across the equatorial eastern central pacific ocean will be lower than normal by 3 – 5 ° c in the united states an appearance of la niña happens for at least five months of la niña conditions it has extensive effects on the weather in north america even affecting the atlantic hurricane season a la niña often though not always follows an el niño
labial fusion is a medical condition of the female genital anatomy where the labia minora become fused together it is generally a pediatric condition the condition is known by a number of names including labial fusion labial adhesion labial synechiae labial agglutination labial adherence gynatresia vulvar fusion and vulvar synechiae
laboratory animal allergy laa is an occupational disease of laboratory animal technicians and scientists it manifests as an allergic response to animal urine specifically the major urinary proteins mups of rodents and can lead to the development of asthma a study of 5641 workers in japan who were exposed to laboratory animals found 23 1 had one or more allergic symptoms globally the prevalence among at risk workers is estimated between 11 and 30 according to the national institutes of health prevention of animal allergy depends on the control of allergens in the work environment this involves a combination of measures to eliminate or control allergen exposure including engineering administrative controls and personal protective equipment the protein product of the mouse mup 17 gene known as mus m 1 ag 1 or ma 1 accounts for much of the allergenic properties of mouse urine similarly the product of the rat mup 13 gene rat n 1 is also a potent human allergen one study found that two thirds of laboratory workers who had developed asthmatic reactions to animals had antibodies to rat n 1
a labyrinthine fistula is an abnormal opening in the bony capsule of the inner ear resulting in leakage of the perilymph from the semicircular canals into the middle ear this includes specifically a perilymph fistula plf an abnormal connection between the fluid of the inner ear and the air filled middle ear this connection is caused by a rupture of the oval window or round window that separate the inner and middle ear another type of l f is a semicircular canal dehiscence which allows the inner ear to be influenced by the intracranial pressure directly
labyrinthitis also known as vestibular neuritis is inflammation of the inner ear it results in vertigo and also possible hearing loss or ringing in the ears it can occur as a single attack a series of attacks or a persistent condition that diminishes over three to six weeks it may be associated with nausea vomiting vestibular neuronitis may also be associated with eye nystagmus the cause is often not clear it may be due to a virus but it can also arise from bacterial infection head injury extreme stress an allergy or as a reaction to medication 30 of affected people had a common cold prior to developing the disease either bacterial or viral labyrinthitis can cause permanent hearing loss in rare cases this appears to result from an imbalance of neuronal input between the left and right inner ears vestibular neuritis affects approximately 3 5 per 100 000 people per year the typical age of onset is between 30 and 60 years and the age distribution plateau is between 40 and 50 years there is no significant gender difference it derives its name from the labyrinths that house the vestibular system which senses changes in head position
lac is the scarlet resinous secretion of a number of species of lac insects of which the most commonly cultivated species is kerria lacca cultivation begins when a farmer gets a stick broodlac that contains eggs ready to hatch and ties it to the tree to be infested thousands of lac insects colonize the branches of the host trees and secrete the resinous pigment the coated branches of the host trees are cut and harvested as sticklac the harvested sticklac is crushed and sieved to remove impurities the sieved material is then repeatedly washed to remove insect parts and other soluble material the resulting product is known as seedlac the prefix seed refers to its pellet shape seedlac which still contains 3 – 5 impurities is processed into shellac by heat treatment or solvent extraction the leading producer of lac is jharkhand followed by the chhattisgarh west bengal and maharashtra states of india lac production is also found in bangladesh myanmar thailand laos vietnam parts of china and mexico
lachiewicz – sibley syndrome is a rare autosomal dominant disorder characterized by preauricular pits and renal disease persons with this disease may have hypoplasic kidneys or proteinuria this disease was first described in a caucasian family of british and irish descent that emigrated to ohio in the 19 th century before settling in nebraska many of the members of this family still live in nebraska although the relatives are now scattered throughout the country unlike branchio oto renal bor syndrome lachiewicz – sibley syndrome is characterized by only preauricular pitting and renal disease persons with bor syndrome also present with hearing loss branchial fistulas or cysts malformed ears and lacrimal stenosis other anomalies in bor syndrome may include a long narrow face a deep overbite and facial paralysis it was characterized in 1985
lacquer dermatitis also known as lacquer sensitivity is a cutaneous condition characterized by a contact dermatitis to various lacquers
the lacrimal caruncle or caruncula lacrimalis is the small pink globular nodule at the inner corner the medial canthus of the eye it is made of skin covering sebaceous and sweat glands with ocular allergies the lacrimal caruncle and the plica semilunaris of the conjunctiva may be inflamed and pruritic itchy due to histamine release in the tissue and tear film
lactation failure or deficiency also known as agalactia or agalactorrhea as well as hypogalactia or hypogalactorrhea is a medical condition in which lactation is insufficient or fails completely due to an inadequacy of breast milk production and or a failure of the milk let down reflex in response to suckling following childbirth resulting in an inability to properly breastfeed
lactational amenorrhea is the temporary postnatal infertility that occurs when a woman is amenorrheic not menstruating and fully breastfeeding
lactic acidosis is a medical condition characterized by the buildup of lactate especially l lactate in the body with as a result an excessively low ph it is a subtype of metabolic acidosis where there is excessive acid due to a problem with the body s metabolism lactic acidosis is typically the result of an underlying acute or chronic medical condition medication or poisoning the symptoms are generally attributable to these underlying causes but may include nausea vomiting rapid deep breathing and generalised weakness the diagnosis is made on biochemical analysis of blood often initially on arterial blood gas samples and once confirmed there is generally a need to establish the underlying cause to treat the acidosis in some situations hemofiltration purification of the blood is temporarily required in rare chronic forms of lactic acidosis caused by mitochondrial disease a specific diet or dichloroacetate may be used the prognosis of lactic acidosis depends largely on the underlying cause in some situations such as severe infections it indicates an increased risk of death
lactose intolerance is the inability of adults and children to digest lactose a sugar found in milk and to a lesser extent dairy products causing side effects it is due to a lactase deficiency or hypolactasia in extremely rare cases mainly limited to finland individuals have congenital alactasia a total absence of lactase caused by a genetic defect which prevents them from being able to digest lactose from infancy including breast milk lactose intolerant individuals have insufficient levels of lactase an enzyme that catalyzes the hydrolysis of lactose into glucose and galactose in their digestive system in most cases this causes symptoms which may include abdominal bloating and cramps flatulence diarrhea nausea borborygmi rumbling stomach or vomiting after consuming significant amounts of lactose it is common for patients with inflammatory bowel disease to experience gastrointestinal symptoms after lactose ingestion although the prevalence of lactase deficiency in this population has not been well studied most mammals normally cease to produce lactase lactase nonpersistence becoming lactose intolerant after weaning but some human populations have developed lactase persistence in which lactase production continues into adulthood which likely developed as a response to growing benefits of being able to digest the milk of farm animals such as cattle research reveals intolerance to be more common globally than lactase persistence and that the variation has been tied to genetics but that the largest source of variation has been shown to be based on exposure e g cultures that consume dairy the frequency of lactose intolerance ranges from 5 in northern european to more than 90 in some african and asian countries some have argued that this links intolerance to natural selection favoring lactase persistent individuals but it is also consistent with a physiological response to decrease lactase production when it is not needed in cultures in which dairy products are not an available food source although populations in europe india arabia and africa were first thought to have high frequencies of lactase persistence because of a single mutation lactase persistence has been traced to a number of mutations that occurred independently healthy people with lactase nonpersistence are able to consume at least one cup of milk without developing symptoms and this tolerance is improved by consuming the milk with a meal preferably lactose reduced milk adding lactase supplements or replacing milk by yogurt or hard cheeses
lacunar amnesia is the loss of memory about one specific event it is a type of amnesia that leaves a lacuna a gap in the record of memory
lacunar stroke or lacunar infarct laci is a type of stroke that results from occlusion of one of the penetrating arteries that provides blood to the brain s deep structures patients who present with symptoms of a lacunar stroke but who have not yet had diagnostic imaging performed may be described as suffering from lacunar stroke syndrome lacs much of the current knowledge of lacunar strokes comes from c miller fisher s cadaver dissections of post mortem stroke patients he observed lacunae latin for empty space in the deep brain structures after occlusion of 200 800 μm penetrating arteries and connected them with 5 classic syndromes these syndromes are still noted today though lacunar infarcts are diagnosed based on clinical judgment and radiologic imaging
in analysis a lacunary function also known as a lacunary series is an analytic function that cannot be analytically continued anywhere outside the radius of convergence within which it is defined by a power series the word lacunary is derived from lacuna pl lacunae meaning gap or vacancy the first known examples of lacunary functions involved taylor series with large gaps or lacunae between the non zero coefficients of their expansions more recent investigations have also focused attention on fourier series with similar gaps between non zero coefficients there is a slight ambiguity in the modern usage of the term lacunary series which may be used to refer to either taylor series or fourier series
the lady macbeth effect or macbeth effect is a priming effect that occurs when response to a cleaning cue is increased after having been induced by a feeling of shame the effect is named after the lady macbeth character in the shakespeare play macbeth she imagined bloodstains on her hands after committing murder in one experiment different groups of participants were asked to recall a good or bad past deed after which they were asked to fill in the letters of three incomplete words w h sh er and s p those who had been asked to recall a bad deed were about 60 more likely to respond with cleansing related words like wash shower and soap instead of alternatives such as wish shaker or stop in another experiment experimenters were able to reduce choice supportive bias by having subjects engage in forms of self cleaning the effect is apparently localized enough that those who had been asked to lie verbally preferred an oral cleaning product and those asked to lie in writing preferred a hand cleaning product over the other kind of cleanser and other control items however other researchers have been unable to replicate the basic effect using larger samples very concerning replication difficulties have emerged for three out of four of zhong and liljenquist s original studies i e study 2 study 3 and study 4
laennec s cirrhosis also known as portal cirrhosis alcoholic cirrhosis fatty cirrhosis or atrophic cirrhosis is named after rené laennec a french physician and the inventor of the stethoscope it is a disease of the liver in which the normal lobular architecture is lost with fibrosis scarring and later nodular regeneration laennec s cirrhosis can be associated with inflammatory polyarthritis most commonly affecting the shoulders elbows and knees osteoporosis soft tissue swelling in peripheral joints and sometimes calcific periathritis are seen in the developed world laennec s cirrhosis most commonly affects middle aged males typically ages 40 – 60 this is the most common form of cirrhosis in the u s chronic alcoholism can cause laennec s cirrhosis in areas of the world afflicted with chronic starvation africa and asia the children are most commonly afflicted
lafora disease also called lafora progressive myoclonic epilepsy or melf is a fatal autosomal recessive genetic disorder characterized by the presence of inclusion bodies known as lafora bodies within the cytoplasm of the cells of the heart liver muscle and skin in a later study lafora disease has been and is now viewed as a neurodegenerative disease since prior to the actual formation of lafora bodies there has been seen to be an impairment in the development of cerebral cortical neurons it was further concluded that lafora disease is a complex neurodegenerative disease and also a glycogen metabolism disorder most patients with this disease do not live past the age of twenty five and death within ten years of symptoms is usually inevitable at present there is no cure or treatment for this disease
a lag deposit is the deposition of material winnowed by physical action aeolian processes fluvial processes and tidal processes can remove the finer portion of a sedimentary deposit leaving the coarser material behind lag deposits are found in processes such as central island formation in streams and rivers one theory of desert pavement formation is that they are an aeolian lag deposit armored beaches and inlets can be composed in part by lag deposits of shells or cobbles created when tidal forces strip away the finer sand and silt
lagenidiosis is a type of infectious disease the best known species of lagenidium is lagenidium giganteum a parasite of mosquito larvae used in biological control of mosquitoes the disease lagenidiosis in dogs is caused by a new species of lagenidium that has not yet been properly named lagenidiosis is found in the southeastern united states in lakes and ponds it causes progressive skin and subcutaneous lesions in the legs groin trunk and near the tail the lesions are firm nodules or ulcerated regions with draining tracts regional lymph nodes are usually swollen spread of the disease to distant lymph nodes large blood vessels and the lungs may occur an aneurysm of a great vessel can rupture and cause sudden death
lagophthalmos is defined as the inability to close the eyelids completely blinking covers the eye with a thin layer of tear fluid thereby promoting a moist environment necessary for the cells of the exterior part of the eye the tears also flush out foreign bodies and wash them away this is crucial to maintain lubrication and proper eye health if this process is impaired as in lagophthalmos the eye can suffer abrasions and infections lagopthalmos leads to corneal drying and ulceration
lagrange point colonization is the colonization of the five equilibrium points in the orbit of a planet or its primary moon called lagrangian points the most obvious such points for colonization are those in the earth – moon and in the sun – earth systems although it would generally take days or even weeks to reach the latter with current technology it would be possible to generate energy from sunlight at them nearly continuously since they would due to their considerable distance from earth be shaded from the sun only seldom and then only shortly
lahaina noon is a tropical solar phenomenon where the sun passes exactly overhead at solar noon the subsolar point the term lahaina noon was coined by the bishop museum in hawaii and is only used locally
a lake burst old irish lochthomadmand is a phenomenon referred to in irish mythology in which a previously non existent lake comes into being often when a grave is being dug
lake stratification is the separation of lakes into three layers 1 epilimnion top of the lake 2 metalimnion or thermocline middle layer that may change depth throughout the day 3 hypolimnion the bottom layer the thermal stratification of lakes refers to a change in the temperature at different depths in the lake and is due to the change in water s density with temperature cold water is denser than warm water and the epilimnion generally consists of water that is not as dense as the water in the hypolimnion however the temperature of maximum density for freshwater is 4 ° c in temperate regions where lake water warms up and cools through the seasons a cyclical pattern of overturn occurs that is repeated from year to year as the cold dense water at the top of the lake sinks for example in dimictic lakes the lake water turns over during the spring and the fall this process occurs more slowly in deeper water and as a result a thermal bar may form if the stratification of water lasts for extended periods the lake is meromictic conversely for most of the time the relatively shallower meres are unstratified that is the mere is considered all epilimnion the accumulation of dissolved carbon dioxide in three meromictic lakes in africa lake nyos and lake monoun in cameroon and lake kivu in rwanda is potentially dangerous because if one of these lakes is triggered into limnic eruption a very large quantity of carbon dioxide can quickly leave the lake and displace the oxygen needed for life by people and animals in the surrounding area natural resource and environmental managers are often challenged by problems caused by lake and pond thermal stratification fish die offs have been directly associated with thermal gradients stagnation and ice cover excessive growth of plankton may limit the recreational use of lakes and the commercial use of lake water with severe thermal stratification in a lake the quality of drinking water also can be adversely affected for fisheries managers the spatial distribution of fish within a lake is often adversely affected by thermal stratification and in some cases may indirectly cause large die offs of recreationally important fish one commonly used tool to reduce the severity of these lake management problems is to eliminate or lesson thermal stratification through aeration many types of aeration equipment have been used to thermally destratify lakes aeration has met with some success although it has rarely proved to be a panacea
lakshmi narayan or lakshmi narayana sanskrit लक्ष्मी नारायण iast lakṣmīnārāyaṇa also sometimes spelled lakshminarayan lakshminarayana laxminarayana is a manifestation of vishnu in the hindu religion it is usually referring to vishnu also known as narayan when he is with his consort lakshmi in his abode vaikuntha lakshmi is depicted as standing next to a dark skinned vishnu who is holding a conch mace lotus and the sudarshana chakra another depiction of lakshminarayan portrays lakshmi in the service of narayan who is reclining on the cosmic serpent sesha floating in kshīrsagār the ocean of milk
in physics the lamb shift named after willis lamb 1913 – 2008 is a difference in energy between two energy levels 2 s 1 2 and 2 p 1 2 in term symbol notation of the hydrogen atom which was not predicted by the dirac equation according to which these states should have the same energy interaction between vacuum energy fluctuations and the hydrogen electron in these different orbitals is the cause of the lamb shift as was shown subsequent to its discovery the lamb shift has since played a significant role through its validation of vacuum energy fluctuations in the discovery of hawking radiation from black holes this effect was first measured in 1947 in the lamb – retherford experiment on the hydrogen microwave spectrum and this measurement provided the stimulus for renormalization theory to handle the divergences it was the harbinger of modern quantum electrodynamics developed by julian schwinger richard feynman ernst stueckelberg sin itiro tomonaga and freeman dyson lamb won the nobel prize in physics in 1955 for his discoveries related to the lamb shift
lambdacism from the greek letter lambda is a medical condition or speech impediment related to the pronunciation of l or related phonemes a common form of lambdacism is lallation the substitution of l for ɹ in pronunciation it is a common feature of japanese and korean pronunciation of english it occurs to a lesser extent in mandarin chinese and other languages substitution of l for n at the beginning of a word or syllable or the reverse at the end is also a feature in certain east asian languages such as cantonese and thai
lambert – eaton myasthenic syndrome lems also lambert – eaton syndrome or eaton – lambert syndrome is a rare autoimmune disorder that is characterized by muscle weakness of the limbs it is the result of an autoimmune reaction in which antibodies are formed against presynaptic voltage gated calcium channels and likely other nerve terminal proteins in the neuromuscular junction the connection between nerves and the muscle that they supply the prevalence is 3 4 cases per million around 60 of those with lems have an underlying malignancy most commonly small cell lung cancer it is therefore regarded as a paraneoplastic syndrome a condition that arises as a result of cancer elsewhere in the body lems usually occurs in people over 40 years of age but it may occur any age the diagnosis is usually confirmed with electromyography and blood tests these also distinguish it from myasthenia gravis mg a related autoimmune neuromuscular disease if the disease is associated with cancer direct treatment of the cancer often relieves the symptoms of lems other treatments often used are steroids azathioprine which suppress the immune system intravenous immunoglobulin which outcompetes autoreactive antibody from fc receptors and pyridostigmine and 3 4 diaminopyridine which enhance the neuromuscular transmission occasionally plasma exchange is required to remove the antibodies
in domain name systems a lame delegation also known as a lame response is a type of error that results when a name server is designated as the authoritative server for a domain name for which it does not have authoritative data american registry for internet numbers arin has a draft policies and proposals concerning lame delegations policy 2002 1 lame delegations in in addr arpa see
lamellar ichthyosis also known as ichthyosis lamellaris and nonbullous congenital ichthyosis is a rare inherited skin disorder affecting around 1 in 600 000 people
laminitis is a disease that affects the feet of hooved animals ungulates and it is found mostly in horses and cattle clinical signs include foot tenderness progressing to inability to walk increased digital pulses and increased temperature in the hooves severe cases with outwardly visible clinical signs are known by the colloquial term and progression of the disease may lead to perforation of the coffin bone through the sole of the hoof requiring aggressive treatment or euthanasia
land footprint is the real amount of land wherever it is in the world that is needed to produce a product or used by an organisation or by a nation
in physics landau damping named after its discoverer the eminent soviet physicist lev landau 1908 68 is the effect of damping exponential decrease as a function of time of longitudinal space charge waves in plasma or a similar environment this phenomenon prevents an instability from developing and creates a region of stability in the parameter space it was later argued by donald lynden bell that a similar phenomenon was occurring in galactic dynamics where the gas of electrons interacting by electrostatic forces is replaced by a gas of stars interacting by gravitation forces landau damping can be manipulated exactly in numerical simulations such as particle in cell simulation
landau – kleffner syndrome lks — also called infantile acquired aphasia acquired epileptic aphasia or aphasia with convulsive disorder — is a rare childhood neurological syndrome it is named after william landau and frank kleffner who characterized it in 1957 with a diagnosis of six children
a landslide also known as a landslip is a form of mass wasting that includes a wide range of ground movements such as rockfalls deep failure of slopes and shallow debris flows landslides can occur in underwater called a submarine landslide coastal and onshore environments although the action of gravity is the primary driving force for a landslide to occur there are other contributing factors affecting the original slope stability typically pre conditional factors build up specific sub surface conditions that make the area slope prone to failure whereas the actual landslide often requires a trigger before being released landslides should not be confused with mud flows a form of mass wasting involving very to extremely rapid flow of debris that has become partially or fully liquefied by the addition of significant amounts of water to the source material
lane is a cryptographic hash function submitted to the nist hash function competition it was designed by sebastiaan indesteege with contributions by elena andreeva christophe de cannière orr dunkelman emilia käsper svetla nikova bart preneel and elmar tischhauser it re uses many components from aes in a custom construction the authors claim performance of up to 25 66 cycles per byte on an intel core 2 duo
langer mesomelic dysplasia lmd is a rare congenital disorder characterized by an altered bone formation that causes a severe short and disproportionate stature
langerhans cell histiocytosis lch is a rare disease involving clonal proliferation of langerhans cells abnormal cells deriving from bone marrow and capable of migrating from skin to lymph nodes clinically its manifestations range from isolated bone lesions to multisystem disease lch is part of a group of clinical syndromes called histiocytoses which are characterized by an abnormal proliferation of histiocytes an archaic term for activated dendritic cells and macrophages these diseases are related to other forms of abnormal proliferation of white blood cells such as leukemias and lymphomas the disease has gone by several names including hand – schüller – christian disease abt letterer siwe disease and histiocytosis x until it was renamed in 1985 by the histiocyte society
langerhans cell sarcoma is a form of malignant histiocytosis it should not be confused with langerhans cell histiocytosis which is cytologically benign langerhans cell sarcoma is known to transform into leukemia it can present in the lung but such cases are rare
langer giedion syndrome lgs also called trichorhinophalangeal syndrome type ii trps 2 or lgcr for langer giedion chromosome region is a very uncommon autosomal dominant genetic disorder caused by a deletion of chromosomal material it is named after the two doctors who undertook the main research into the condition in the 1960 s diagnosis is usually made at birth or in early childhood
in mathematics the langlands – deligne local constant or local artin root number up to an elementary function of s is an elementary function associated with a representation of the weil group of a local field the functional equation l ρ s ε ρ s l ρ ∨ 1 − s of an artin l function has an elementary function ε ρ s appearing in it equal to a constant called the artin root number times an elementary real function of s and langlands discovered that ε ρ s can be written in a canonical way as a product ε ρ s π ε ρv s ψv of local constants ε ρv s ψv associated to primes v tate proved the existence of the local constants in the case that ρ is 1 dimensional in tate s thesis proved the existence of the local constant ε ρv s ψv up to sign the original proof of the existence of the local constants by used local methods and was rather long and complicated and never published later discovered a simpler proof using global methods
langley ’ s adventitious angles is a mathematical problem posed by edward mann langley in the mathematical gazette in 1922
language is the ability to acquire and use complex systems of communication particularly the human ability to do so and a language is any specific example of such a system the scientific study of language is called linguistics questions concerning the philosophy of language such as whether words can represent experience have been debated since gorgias and plato in ancient greece thinkers such as rousseau have argued that language originated from emotions while others like kant have held that it originated from rational and logical thought 20 th century philosophers such as wittgenstein argued that philosophy is really the study of language major figures in linguistics include ferdinand de saussure and noam chomsky estimates of the number of languages in the world vary between 5 000 and 7 000 however any precise estimate depends on a partly arbitrary distinction between languages and dialects natural languages are spoken or signed but any language can be encoded into secondary media using auditory visual or tactile stimuli – for example in whistling signed or braille this is because human language is modality independent depending on philosophical perspectives regarding the definition of language and meaning when used as a general concept language may refer to the cognitive ability to learn and use systems of complex communication or to describe the set of rules that makes up these systems or the set of utterances that can be produced from those rules all languages rely on the process of semiosis to relate signs to particular meanings oral and sign languages contain a phonological system that governs how symbols are used to form sequences known as words or morphemes and a syntactic system that governs how words and morphemes are combined to form phrases and utterances human language has the properties of productivity recursivity and displacement and relies entirely on social convention and learning its complex structure affords a much wider range of expressions than any known system of animal communication language is thought to have originated when early hominins started gradually changing their primate communication systems acquiring the ability to form a theory of other minds and a shared intentionality this development is sometimes thought to have coincided with an increase in brain volume and many linguists see the structures of language as having evolved to serve specific communicative and social functions language is processed in many different locations in the human brain but especially in broca s and wernicke s areas humans acquire language through social interaction in early childhood and children generally speak fluently when they are approximately three years old the use of language is deeply entrenched in human culture therefore in addition to its strictly communicative uses language also has many social and cultural uses such as signifying group identity social stratification as well as social grooming and entertainment languages evolve and diversify over time and the history of their evolution can be reconstructed by comparing modern languages to determine which traits their ancestral languages must have had in order for the later developmental stages to occur a group of languages that descend from a common ancestor is known as a language family the indo european family is the most widely spoken and includes languages such as english russian and hindi the sino tibetan family which includes mandarin and the other chinese languages and tibetan the afro asiatic family which includes arabic somali and hebrew the bantu languages which include swahili and zulu and hundreds of other languages spoken throughout africa and the malayo polynesian languages which include indonesian malay tagalog and hundreds of other languages spoken throughout the pacific the languages of the dravidian family that are spoken mostly in southern india include tamil and telugu academic consensus holds that between 50 and 90 of languages spoken at the beginning of the 21 st century will probably have become extinct by the year 2100
in microsoft terminology a language interface pack lip is a skin for localizing a windows operating system in languages such as lithuanian serbian hindi marathi kannada tamil and thai based on multilingual user interface mui technology a lip also requires the software to have a base installed language and provides users with an approximately 80 percent localized user experience by translating a reduced set of user interface elements unlike mui packs which are available only to microsoft volume license customers and for specific skus of windows vista a language interface pack is available for free and can be installed on a licensed copy of microsoft windows or office and a fixed base language in other words if the desired additional language has incomplete localization users may add it for free while if the language has complete localization the user must pay for it by licensing a premium version of windows in windows vista and windows 7 only the enterprise and ultimate editions are multilingual typically a language interface pack is designed for regional markets that do not have full mui packs or fully localized versions of a product it is an intermediate localized solution that enables computer users to adapt their software to display many commonly used features in their native language each new language interface pack is built using the glossary created by the community glossary project in cooperation with the local government academia and local linguistic experts
language disorders or language impairments are disorders that involve the processing of linguistic information problems that may be experienced can involve grammar syntax and or morphology semantics meaning or other aspects of language these problems may be receptive involving impaired language comprehension expressive involving language production or a combination of both examples include specific language impairment and aphasia among others language disorders can affect both spoken and written language and can also affect sign language typically all forms of language will be impaired current data indicates that 7 of young children display language disorder with boys being diagnosed twice as much as girls preliminary research on potential risk factors have suggested biological components such as low birth weight prematurity general birth complications and male gender as well as family history and low parental education can increase the chance of developing language disorders for children with phonological and expressive language difficulties there is evidence supporting speech and language therapy however the same therapy is shown to be much less effective for receptive language difficulties these results are consistent with the poorer prognosis for receptive language impairments that are generally accompanied with problems in reading comprehension note that these are distinct from speech disorders which involve difficulty with the act of speech production but not with language
in natural language processing language identification or language guessing is the problem of determining which natural language given content is in computational approaches to this problem view it as a special case of text categorization solved with various statistical methods
language proficiency or linguistic proficiency is the ability of an individual to speak or perform in an acquired language as theories among pedagogues as to what constitutes proficiency go there is little consistency as to how different organizations classify it additionally fluency and language competence are generally recognized as being related but separate controversial subjects in predominant frameworks in the united states proficient speakers demonstrate both accuracy and fluency and use a variety of discourse strategies thus native speakers of a language can be fluent without being considered proficient native level fluency is estimated to be between 20 000 – 40 000 words but basic conversational fluency might only require as little as 3 000 words
large cell acanthomas are a cutaneous condition characterized by small skin colored hyper or hypopigmented papules or plaques
large cell carcinoma lcc is a heterogeneous group of undifferentiated malignant neoplasms that lack the cytologic and architectural features of small cell carcinoma and glandular or squamous differentiation lcc is categorized as a type of nsclc non small cell carcinoma which originates from epithelial cells of the lung 1
large cell lung carcinoma with rhabdoid phenotype lclc rp is a rare histological form of lung cancer currently classified as a variant of large cell lung carcinoma lclc in order for a lclc to be subclassified as the rhabdoid phenotype variant at least 10 of the malignant tumor cells must contain distinctive structures composed of tangled intermediate filaments that displace the cell nucleus outward toward the cell membrane the whorled eosinophilic inclusions in lclc rp cells give it a microscopic resemblance to malignant cells found in rhabdomyosarcoma rms a rare neoplasm arising from transformed skeletal muscle despite their microscopic similarities lclc rp is not associated with rhabdomyosarcoma although rhabdoid variants of lclc are sometimes referred to as rhabdoid carcinomas this particular term should be reserved for examples of pure rhabdoid neoplasms i e those that do not contain cells containing other histological variants
one classification system for lymphomas divides the diseases according to the size of the white blood cells that has turned cancerous the large cell lymphomas have large cells a large cell in this context has a diameter of 17 to 20 µm other groups of lymphomas in this system are the small cell lymphomas and mixed cell lymphomas
large b cell lymphoma arising in hhv 8 associated multicentric castleman s disease is a type of large b cell lymphoma recognized in the who 2008 classification it is sometimes called the plasmablastic form of multicentric castleman disease it has sometimes been confused with plasmablastic lymphoma in the literature although that is a dissimilar specific entity it has variable cd 20 expression and unmutated immunoglobulin variable region genes
large for gestational age lga is an indication of high prenatal growth rate lga is often defined as a weight length or head circumference that lies above the 90 th percentile for that gestational age however it has been suggested that the definition be restricted to infants with birth weights greater than the 97 th percentile 2 standard deviations above the mean as this more accurately describes infants who are at greatest risk for perinatal morbidity and mortality macrosomia which literally means big body is sometimes confused with lga some experts consider a baby to be big when it weighs more than 8 pounds 13 ounces 4 000 g at birth and others say a baby is big if it weighs more than 9 pounds 15 ounces 4 500 g a baby is also called “ large for gestational age ” if its weight is greater than the 90 th percentile at birth
large granular lymphocytic lgl leukemia is a chronic lymphoproliferative disorder that exhibits an unexplained chronic 6 months elevation in large granular lymphocytes lgls in the peripheral blood it is divided in two main categories t cell lgl t lgl leukemia and natural killer nk cell lgl nk lgl leukemia as the name suggests t cell large granular lymphocyte leukemia is characterized by involvement of cytotoxic t cells it is also known by the following terms proliferation of large granular lymphocytes lgls lgl leukemia tγ lymphoproliferative disorder and in common with other t cell leukemias such as t cell prolymphocytic leukemia t cell chronic lymphocytic leukemia
large plaque parapsoriasis also known as parapsoriasis en plaques are skin lesions that may be included in the modern scheme of cutaneous conditions described as parapsoriasis these lesions called plaques may be irregularly round shaped to oval and are 10 cm 3 9 in or larger in diameter they can be very thin plaques that are symptomatic or mildly pruritic large plaque parapsoriasis is a common associate of retiform parapsoriasis can be accompanied by poikiloderma vasculare atrophicans and can in rare occasions be a precursor to cutaneous t cell lymphoma
in computational geometry the largest empty rectangle problem maximal empty rectangle problem or maximum empty rectangle problem is the problem of finding a rectangle of maximal size to be placed among obstacles in the plane there are a number of variants of the problem depending on the particularities of this generic formulation in particular depending on the measure of the size domain type of obstacles and the orientation of the rectangle the problems of this kind arise e g in electronic design automation in design and verification of physical layout of integrated circuits a maximal empty rectangle mer is a rectangle which is not contained in another empty rectangle each side of a mer abuts an obstacle otherwise the side may be shifted outwards increasing the empty rectangle an application of this kind is enumeration of maximal white rectangles in image segmentation r d of image processing and pattern recognition in the contexts of many algorithms for largest empty rectangles maximal empty rectangles are candidate solutions to be considered by the algorithm since it is easily proven that e g a maximum area empty rectangle is a maximal empty rectangle
in computational geometry the largest empty sphere problem is the problem of finding a hypersphere of largest radius in d dimensional space whose interior does not overlap with any given obstacles
the larock indole synthesis is a heteroannulation reaction that uses palladium as a catalyst to synthesize indoles from an ortho iodoaniline and a disubstituted alkyne it is also known as larock heteroannulation the reaction is extremely versatile and can be used to produce varying types of indoles larock indole synthesis was first proposed by richard c larock in 1991 at iowa state university
laron s syndrome or laron type dwarfism is an autosomal recessive disorder characterized by an insensitivity to growth hormone gh usually caused by a mutant growth hormone receptor it causes short stature and an increased sensitivity to insulin which means that they are less likely to develop diabetes mellitus type 2 and possibly cancer as well it can be treated with injections of recombinant igf 1
larsen syndrome ls is a congenital disorder discovered in 1950 by larsen and associates when they observed dislocation of the large joints and face anomalies in six of their patients patients suffering from larsen syndrome normally present with a variety of symptoms including congenital anterior dislocation of the knees dislocation of the hips and elbows flattened facial appearance prominent foreheads and depressed nasal bridges larsen syndrome can also cause a variety of cardiovascular and orthopedic abnormalities this rare disorder is caused by a genetic defect in the gene encoding filamin b a cytoplasmic protein that is important in regulating the structure and activity of the cytoskeleton the gene that influences the emergence of larsen syndrome is found in chromosome region 3 p 21 1 14 1 a region containing human type vii collagen gene larsen syndrome has recently been described as a mesenchyme disorder that affects the connective tissue of an individual autosomal dominant and recessive forms of the disorder have been reported although most cases are autosomal dominant reports have found that in western societies larsen syndrome can be found in one in every 100 000 births but this is most likely an underestimate because the disorder is frequently unrecognized or misdiagnosed
larval hemolymph feeding is a behaviour trait found in the queens of some species of ant this is found mainly in the ants of the subfamily amblyoponinae and give them the other name of dracula ant in colonies of the amblyopone silvestrii the queens feed on the hemolymph or insect blood also spelt haemolymph of their larvae when food is not available this is said to be a precursor to trophallaxis in other ant families the larvae themselves are not killed by this process this behaviour is also seen in proceratium and in leptanilla the larvae have special organs that exude the haemolymph are exclusively dependent on the hemolymph of their own larvae as a nutrient even when prey feeding is possible on the other hand the foundresses suppress larval hemolymph feeding lhf when prey is available allowing them to rear the first workers more swiftly the nondestructive form of cannibalism can be regarded as a nutritive adaptation related to 1 the lack of social food transfer in this species and 2 its specialized predation on large sporadic prey centipedes lhf similar to that in amblyopone was found in proceratium and another type of lhf with a larval specialized exudatory organ in leptanilla
larviform female is biological phenomenon occurring in some species where the females in the adult stage of metamorphosis resemble the larvae to various degrees typically the female is wingless and generally larger than the male larviform females occur in many insect groups including many beetle species
laryngeal cancer also known as cancer of the larynx or laryngeal carcinoma are mostly squamous cell carcinomas reflecting their origin from the skin of the larynx cancer can develop in any part of the larynx but the cure rate is affected by the location of the tumour for the purposes of tumour staging the larynx is divided into three anatomical regions the glottis true vocal cords anterior and posterior commissures the supraglottis epiglottis arytenoids and aryepiglottic folds and false cords and the subglottis most laryngeal cancers originate in the glottis supraglottic cancers are less common and subglottic tumours are least frequent laryngeal cancer may spread by direct extension to adjacent structures by metastasis to regional cervical lymph nodes or more distantly through the blood stream distant metastases to the lung are most common in 2013 it resulted in 88 000 deaths up from 76 000 deaths in 1990 five year survival rates in the united states are 60
a laryngeal cleft or laryngotracheoesophageal cleft is a rare congenital abnormality in the posterior laryngo tracheal wall it occurs in approximately 1 in 10 000 to 20 000 births it means there is a gap between the oesophagus and trachea which allows food or fluid to pass into the airway
laryngeal cysts are cysts involving the larynx or more frequently supraglottic locations such as epiglottis and vallecula usually they do not extend to the thyroid cartilage they may be present congenitally or may develop eventually due to degenerative cause they often interfere with phonation
laryngeal papillomatosis also known as recurrent respiratory papillomatosis or glottal papillomatosis or associated with condyloma acuminata is a rare medical condition 2 per 100 000 adults and 4 5 per 100 000 children caused by an hpv infection of the throat laryngeal papillomatosis causes assorted tumors or papillomas to develop over a period of time without treatment it is potentially fatal as uncontrolled growths could obstruct the airway laryngeal papillomatosis is caused by hpv types 6 and 11 in which benign tumors form on the larynx or other areas of the respiratory tract these tumors can recur frequently may require repetitive surgery and may interfere with breathing the disease can be treated with surgery and antivirals in addition antiangiogenic therapy shows promising results
laryngeal paralysis in animals is a condition in which the nerves and muscles that control the movements of one or both arytenoid cartilages of the larynx cease to function and instead of opening during inspiration and closing during swallowing the arytenoids remain stationary in a somewhat neutral position specifically the muscle that causes abduction of the arytenoid cartilage the cricoarytenoideus dorsalis muscle ceases to function this leads to inadequate ventilation during exercise and during thermoregulatory panting as well as incomplete protection of the airway during swallowing one of the commonest forms of laryngeal paralysis develops in geriatric medium to large breed dogs in particular the labrador retriever but also some other breeds this had been traditionally known as idiopathic largyngeal paralysis ilp idiopathic means of unknown cause and was believed to be a result of a condition affecting the nerves of the larynx bilateral mononeuropathy of the recurrent laryngeal nerves however investigations into ilp by two groups in michigan and tennessee between 2005 2013 showed that the condition was not limited to or specifically a result of dysfunction of the laryngeal nerves instead it was the most visible symptom of a slowly progressing polyneuropathy of old age which also affected other nerves in the body this finding now generally believed correct following further research has led to the proposed renaming of this type of laryngeal paralysis from idiopathic laryngeal paralysis ilp to geriatric onset laryngeal paralysis polyneuropathy golpp animals affected by laryngeal paralysis have reduced tolerance for exercise and heat and an increased risk of aspiration pneumonia the condition is not generally regarded as causing pain other than physical distress and anxiety caused by any difficulty in breathing or emotional distress from any difficulty with physical movement where laryngeal paralysis is related to a general progressive polyneuropathy as in golpp the nervous system will gradually degenerate causing increasing difficulty in management of the limbs especially rear limbs swallowing and breathing and eventually in most cases euthanasia laryngeal paralysis is fairly common in large breed and geriatric dogs particularly in the labrador retriever is rarely found in cats and can also occur in horses where it is referred to as roaring roarer s syndrome or medically as laryngeal hemiplegia or recurrent laryngeal neuropathy rln laryngeal paralysis can be unilateral or bilateral depending upon dysfunction of one or both arytenoid cartilages
laryngitis is an inflammation of the larynx it causes hoarse voice or temporary loss of the voice due to irritation of the vocal folds vocal cords laryngitis is one possible cause of dysphonia the medical term for a vocal disorder laryngitis is categorised as acute if it lasts less than three weeks and chronic if it lasts over three weeks the chronic form occurs mostly in middle age and is much more common in men than women antibiotics do not appear to be very useful in the acute form
laryngomalacia literally soft larynx is the most common cause of stridor in infancy in which the soft immature cartilage of the upper larynx collapses inward during inhalation causing airway obstruction it can also be seen in older patients especially those with neuromuscular conditions resulting in weakness of the muscles of the throat however the infantile form is much more common laryngomalacia is one of the most common laryngeal congenital disease in infancy and public education about the signs and symptoms of the disease is lacking
shabbir syndrome also known as laryngo – onycho – cutaneous syndrome is a cutaneous condition inherited in an autosomal recessive fashion it was characterized by shabbir in 1986 it may be associated with lama 3
in medicine laryngospasm is an uncontrolled involuntary muscular contraction spasm of the vocal folds the condition typically lasts less than 60 seconds but in some cases can last 20 30 minutes and causes a partial blocking of breathing in while breathing out remains easier it may be triggered when the vocal cords or the area of the trachea below the vocal folds detects the entry of water mucus blood or other substance it is characterized by stridor and or retractions some people suffer from frequent laryngospasms whether awake or asleep in an ear nose and throat practice it is typically seen in people who have silent reflux disease it is also a well known infrequent but serious perioperative complication
laryngotracheal stenosis refers to abnormal narrowing of the central air passageways this can occur at the level of the larynx trachea carina or main bronchi in a small number of patients narrowing may be present in more than one anatomical location
the las palmas complex is an archaeological pattern recognized primarily on the basis of mortuary customs in the cape region of baja california sur mexico the complex is focused on the occurrence in caves or rockshelters of secondary human burials containing bones painted with red ochre the skulls in such burials tend to be extremely long headed hyperdolichocephalic leading to suggestions that makers of the las palmas complex identified with the historically known pericú might represent either a genetically isolated remnant of a very early wave of immigrants into the americas or later trans pacific migrants other elements in the material inventory of the las palmas complex include stone grinding basins atlatls lark s head netting coiled basketry and sewn palm bark containers the distinctive burial pattern was recognized in the late nineteenth century by herman ten kate and léon diguet archaeologist william c massey investigated and described the las palmas complex in detail
lassa fever or lassa hemorrhagic fever lhf is an acute viral hemorrhagic fever caused by the lassa virus and first described in 1969 in the town of lassa in borno state nigeria lassa virus is a member of the arenaviridae virus family similar to ebola clinical cases of lassa fever had been known for over a decade but had not been connected with a viral pathogen the primary animal host of the lassa virus is the natal multimammate mouse mastomys natalensis an animal found in most of sub saharan africa the virus is probably transmitted by contact with the feces or urine of animals accessing grain stores in residences given its high rate of incidence lassa fever is a major problem in affected countries lassa fever occurs commonly in west africa it results in 300 000 to 500 000 cases annually and causes about 5 000 deaths each year outbreaks of the disease have been observed in nigeria liberia sierra leone guinea and the central african republic
latah from southeast asia is a condition in which abnormal behaviors result from a person experiencing a sudden shock when surprised the affected person typically engages in such behaviors as screaming cursing dancing type movements and uncontrollable laughter and will typically mimic the words or actions of those around them physical symptoms include an increased heart rate and profuse sweating but no clear physiological source has been identified latah is considered a culture specific startle disorder that was historically regarded as personal difference rather than an illness similar conditions have been recorded within other cultures and locations for example there are the so called jumping frenchmen of maine the women of the ainu people of japan imu the siberian miryachit and the filipino and thai peoples however the connection among these syndromes is controversial
in gerontology late life mortality deceleration is the phenomenon of hazard rate increasing at a decreasing rate in late life – rather than increasing exponentially as in the gompertz law – and in some cases plateauing asymptoting at a constant rate graphically on a log linear semi log plot linear in the x axis of age logarithmic in the y axis of hazard rate an exponential function becomes linear and the gompertz law amounts to the hazard rate increasing linearly with age late life mortality deceleration corresponds to hazard rate increasing more slowly than linearly on a log linear graph instead curving and possibly plateauing late life mortality deceleration is a well established phenomenon in insects who often spend much of their life in a constant hazard rate region but it is much more controversial in mammals rodent studies have found varying conclusions with some finding short term periods of mortality deceleration in mice others not finding such and baboon studies show no mortality deceleration an analogous deceleration occurs in failure rate of manufactured products this analogy is elaborated in the reliability theory of aging and longevity late life mortality deceleration was first proposed as occurring in human aging in which also introduced the gompertz law and observed as occurring in humans in and has since become one of the pillars of the biodemography of human longevity – see here late life is typically after 85 years of age however a recent paper concludes that mortality deceleration is negligible up to the age of 106 in the population studied beyond this point reliable data were unavailable and that the gompertz law is a good fit with previous observations of deceleration being spurious with various causes including bad data and methodological problems – see the primary reference for this article is which provides a detailed historical overview and discussion together with current criticism
late congenital syphilitic oculopathy is a disease of the eye a manifestation of late congenital syphilis it can appear as interstitial keratitis – this commonly appears between ages 6 and 12 symptoms include lacrimation and photophobia pathological vascularization of the cornea cause it to turn pink or salmon colored 90 of cases affect both eyes episcleritis or scleritis – nodules appear in or overlying the sclera white of eye iritis or iris papules – vascular infiltration of the iris causes rosy color change and yellow red nodules chorioretinitis papillitis retinal vasculitis – retinal changes can resemble retinitis pigmentosa exudative retinal detachment congenital syphilis is categorized by the age of the child early congenital syphilis occurs in children under 2 years old and late congenital syphilis in children at or greater than 2 years old manifestations of late congenital syphilis are similar to those of secondary syphilis and tertiary syphilis in adults
in medicine a late effect is a condition that appears after the acute phase of an earlier causal condition has run its course a late effect can be caused directly by the earlier condition or indirectly by the treatment for the earlier condition some late effects can occur decades later historically late effects have been very difficult to connect with their causes but as survivorship and life span has increased and follow up has become standard practice these connections are becoming established a period often very long of health unaffected by both the initial and the late effect conditions distinguishes a late effect from a sequela or a complication
a latent human error is a human error which is likely to be made due to systems or routines that are formed in such a way that humans are disposed to making these errors latent human error is a term used in safety work and accident prevention especially in aviation by gathering data about errors made then collating grouping and analyzing them it can be determined whether a disproportionate amount of similar errors are being made if this is the case a contributing factor may be disharmony between the respective systems routines and human nature or propensities the routines or systems can then be analyzed potential problems identified and amendments made if necessary in order to prevent future errors incidents or accidents
latent iron deficiency lid also called iron deficient erythropoiesis is a medical condition in which there is evidence of iron deficiency without anemia normal hemoglobin level it is important to assess this condition because it is accepted that individuals with latent iron deficiency will develop iron deficiency anemia in the weeks or months following diagnoses of lid if they are not treated with iron supplementation in addition there is some evidence of a decrease in vitality and an increase in fatigue among individuals that have lid the clinical features of lid are in discussion some studies have not shown a clear difference between individuals with lid and control a group of the same age gender and origin without lid but may be it is not wrong to say that the persons with lid have a mild decrease in vitality and increase of fatigue what seems important for preventive healthcare is to detect this medical condition because it will avoid the patient probably developing an iron deficiency anemia
a diagnosis of latent tuberculosis ltb also called latent tuberculosis infection ltbi means a patient is infected with mycobacterium tuberculosis but the patient does not have active tuberculosis active tuberculosis can be contagious while latent tuberculosis is not and it is therefore not possible to get tb from someone with latent tuberculosis the main risk is that approximately 10 of these patients 5 in the first two years after infection and 0 1 per year thereafter will go on to develop active tuberculosis this is particularly true and there is added risk in particular situations such as medication that suppresses the immune system or advancing age the identification and treatment of people with latent tb is an important part of controlling this disease various treatment regimens are in use to treat latent tuberculosis which generally need to be taken for several months
lateral earth pressure is the pressure that soil exerts in the horizontal direction the lateral earth pressure is important because it affects the consolidation behavior and strength of the soil and because it is considered in the design of geotechnical engineering structures such as retaining walls basements tunnels deep foundations and braced excavations the coefficient of lateral earth pressure k is defined as the ratio of the horizontal effective stress σ ’ h to the vertical effective stress σ ’ v the effective stress is the intergranular stress calculated by subtracting the pore pressure from the total stress as described in soil mechanics k for a particular soil deposit is a function of the soil properties and the stress history the minimum stable value of k is called the active earth pressure coefficient ka the active earth pressure is obtained for example when a retaining wall moves away from the soil the maximum stable value of k is called the passive earth pressure coefficient kp the passive earth pressure would develop for example against a vertical plow that is pushing soil horizontally for a level ground deposit with zero lateral strain in the soil the at rest coefficient of lateral earth pressure k 0 is obtained there are many theories for predicting lateral earth pressure some are empirically based and some are analytically derived
a lateral eruption also called a flank eruption or lateral blast if explosive is a volcanic eruption that takes place on the flanks of a volcano instead of at the summit lateral eruptions are typical at rift zones where a volcano is breaking apart since it is easier for molten rock to flow laterally out the sides of weak flanks the flank gives way before magma is pushed up through a conduit that feeds magma to the summit these features are commonly found at shield volcanoes and produce basaltic lava flows and cinder cones lateral blasts are understood to be created by immediate decompression of a magma chamber lying not far below the flanks of a volcano similar to what occurred during the 1980 eruption of mount st helens in the u s state of washington or along the base or flanks of a lava dome similar to what happened during the 1902 eruption of mount peléeon the northern tip of the french overseas department of martinique in the lesser antilles island arc of the caribbean
lateral expansion in economics is the growth of a business enterprise through the acquisition of similar companies in the hope of achieving economies of scale or economies of scope unchecked lateral expansion can lead to powerful conglomerates or monopolies related is vertical expansion which is the growth of a business enterprise through the acquisition of companies that produce the intermediate goods needed by the business or help market and distribute its final goods any such value chain activities can be acquired through vertical expansion
lateral masking is a problem for the human visual perception of identical or similar entities in close proximity this can be illustrated by the difficulty of counting the vertical bars of a barcode in linguistics lateral masking refers to the interference a letter has on its neighbor this is a problem readers encounter when reading a word the identity of a letter in the middle of a word is obscured by the presence of its neighboring letters lateral masking may also a problem in orthography design a readable orthography will avoid situations in which a reader is faced with severe lateral masking
lateral medullary syndrome also called wallenberg syndrome and posterior inferior cerebellar artery syndrome is a disorder in which the patient has a constellation of neurologic symptoms due to injury to the lateral part of the medulla in the brain resulting in tissue ischemia and necrosis
the lateral meningocele syndrome is a very rare skeletal disorder with facial anomalies hypotonia and meningocele related neurologic dysfunction
the lateral periodontal cyst is a cyst that arises from the epithelial post functional dental lamina which is a remnant from odontogenesis it is more common in middle aged adult males usually there is no pain associated with it and it usually appears as a unilocular radiolucency dark area on the side of a canine or premolar root commonly seen in mandibular bicuspid area microscopically the lateral periodontal cyst appears the same as the gingival cyst of the adult the involved tooth is usually vital and has no indication for root canal treatment unless the signs of non vital or necrotic pulpal tissue were confirmed treated by surgical enucleation
a lateral pontine syndrome is a lesion which is similar to the lateral medullary syndrome but because it occurs in the pons it also involves the cranial nerve nuclei of the pons
lateral thinking is solving problems through an indirect and creative approach using reasoning that is not immediately obvious and involving ideas that may not be obtainable by using only traditional step by step logic the term was coined in 1967 by edward de bono according to de bono lateral thinking deliberately distances itself from standard perceptions of creativity as either vertical logic the classic method for problem solving working out the solution step by step from the given data or horizontal imagination having many ideas but being unconcerned with the detailed implementation of them
in neuroscience the lateralized readiness potential lrp is an event related brain potential or increase in electrical activity at the surface of the brain that is thought to reflect the preparation of motor activity on a certain side of the body in other words it is a spike in the electrical activity of the brain that happens when a person gets ready to move one arm leg or foot it is a special form of bereitschaftspotential a general pre motor potential lrps are recorded using electroencephalography eeg and have numerous applications in cognitive neuroscience
latex allergy is a medical term encompassing a range of allergic reactions to the proteins present in natural rubber latex latex allergy generally develops after repeated exposure to products containing natural rubber latex when latex containing medical devices or supplies come in contact with mucous membranes the membranes may absorb latex proteins the immune system of some susceptible individuals produces antibodies that react immunologically with these antigenic proteins as many items contain or are made from natural rubber including shoe soles elastic bands rubber gloves condoms baby bottle nipples and balloons there are many possible routes of exposure that may trigger a reaction people with latex allergies may also have or develop allergic reactions to some fruits such as bananas
lathosterolosis is a defect in cholesterol biosynthesis
lathyrism or neurolathyrism is a neurological disease of humans and domestic animals caused by eating certain legumes of the genus lathyrus this problem is mainly associated with lathyrus sativus also known as grass pea kesari dal khesari dal or almorta and to a lesser degree with lathyrus cicera lathyrus ochrus and lathyrus clymenum containing the toxin odap the lathyrism resulting from the ingestion of lathyrus odoratus seeds sweet peas is often referred to as odoratism or osteolathyrism which is caused by a different toxin beta aminopropionitrile that affects the linking of collagen a protein of connective tissues
latrodectism is the illness caused by the bite of latrodectus spiders the black widow spider and related species pain muscle rigidity vomiting and sweating are the hallmarks of latrodectism contrary to popular conception latrodectism is very rarely fatal to people domestic cats have been known to die with convulsion and paralysis there are several spider species all named black widow southern black widow spider l mactans the european black widow l tredecimguttatus western black widow spider l hesperus northern black widow spider l variolus other latrodectus that cause latrodectism are the australian redback spider l hasselti and the katipo spider l katipo several other members of latrodectus genus are not commonly associated with latrodectism including the cosmopolitan brown widow l geometricus
lattice corneal dystrophy type also known as biber haab dimmer dystrophy is a rare form of corneal dystrophy it has no systemic manifestations unlike the other type of the dystrophy lattice corneal dystrophy type ii lattice corneal dystrophy was first described by swiss ophthalmologist hugo biber in 1890 lattice dystrophy gets its name from an accumulation of amyloid deposits or abnormal protein fibers throughout the middle and anterior stroma
lattice degeneration is a disease of the human eye wherein the peripheral retina becomes atrophic in a lattice pattern and may develop tears breaks or holes which may further progress to retinal detachment it is an important cause of retinal detachment in young myopic individuals the cause is unknown but pathology reveals inadequate blood flow resulting in ischemia and fibrosis lattice degeneration occurs in approximately 6 8 of the general population and in approximately 30 of phakic retinal detachments similar lesions are seen in patients with ehlers danlos syndrome marfan syndrome and stickler syndrome all of which are associated with an increased risk of retinal detachment risk of developing lattice degeneration in one eye is also increased if lattice degeneration is already present in the other eye
laughter is a physical reaction in humans and some other species of primate consisting typically of rhythmical often audible contractions of the diaphragm and other parts of the respiratory system it is a response to certain external or internal stimuli laughter can arise from such activities as being tickled or from humorous stories or thoughts most commonly it is considered a visual expression of a number of positive emotional states such as joy mirth happiness relief etc on some occasions however it may be caused by contrary emotional states such as embarrassment apology or confusion such as nervous laughter or courtesy laugh age gender education language and culture are all factors as to whether a person will experience laughter in a given situation laughter is a part of human behavior regulated by the brain helping humans clarify their intentions in social interaction and providing an emotional context to conversations laughter is used as a signal for being part of a group — it signals acceptance and positive interactions with others laughter is sometimes seen as contagious and the laughter of one person can itself provoke laughter from others as a positive feedback this may account in part for the popularity of laugh tracks in situation comedy television shows the study of humor and laughter and its psychological and physiological effects on the human body is called gelotology
laugier – hunziker syndrome english ˈloʊʒieɪ ˈhʊntsᵻɡər is a cutaneous condition characterized by hyperpigmentation of the oral mucosa longitudinal melanonychia and genital melanosis
laurel wilt also called laurel wilt disease is a vascular disease caused by the fungus raffaelea lauricola which is transmitted by the invasive redbay ambrosia beetle xyleborus glabratus the disease affects and kills members of the laurel family the avocado is perhaps the most commercially valuable plant affected by laurel wilt
laurence – moon syndrome lms is a rare autosomal recessive genetic disorder associated with retinitis pigmentosa extra digits spastic paraplegia hypogonadism and mental disabilities
in computer programming jargon lava flow is a problem in which computer code written under sub optimal conditions is put into production and added to while still in a developmental state often putting the system into production results in a need to maintain backward compatibility as many additional components now depend on it with the original incomplete design changes in the development team working on a project often exacerbate lava flows as workers cycle in and out of the project knowledge of the purpose of aspects of the system can be lost rather than clean up these pieces subsequent workers work around them increasing the complexity and mess of the system lava flow is considered an anti pattern a commonly encountered phenomenon leading to poor design
in set theory a laver function or laver diamond named after its inventor richard laver is a function connected with supercompact cardinals
the law of repetition is a phenomenon that occurs when after having spoken on any theme one hears about this issue again soon after for example a person is talking about the characteristics of a dolphin and the next day another person speaks on the same subject who will not have known it had been discussed the day before
a layer is the deposition of molecules on a substrate or base glass ceramic semiconductor or plastic bioplastic high temperature substrates includes stainless steel and polyimide film expensive and pet cheap a depth of less than one micrometre is generally called a thin film while a depth greater than one micrometre is called a coating a web is a flexible substrate
in commercial shipping laytime is the amount of time allowed in hours or days in a voyage charter for the loading and unloading of cargo if the laytime is exceeded demurrage is incurred if the whole period of laytime is not needed despatch may be payable by the shipowner to the charterer depending on the terms of the charter party despatch does not apply to tanker charters laytime and laydays are often confused as referring to the same idea laydays refers to the time when a ship must present itself to the charterer if the ship arrives before the laydays specified the charterer does not have to take control or start loading depending on the type of charter if the ship arrives after the laydays then the contract can be cancelled – hence laydays are often presented as the term laydays and cancelling and can be shortened to laycan the point when laytime commences is determined by a notice of readiness nor which the master or agent of the ship must give to the charterer when the ship has arrived at the port of loading or discharge the nor informs the charterer that the ship has arrived at the port and is ready in all respects to load or discharge
a lazarus pit is a fictional natural phenomenon appearing in american comic books published by dc comics lazarus pits are primarily found in the batman titles and are commonly used by ra s al ghul for their restorative powers
lazarus syndrome also known as autoresuscitation after failed cardiopulmonary resuscitation is the spontaneous return of circulation after failed attempts at resuscitation its occurrence has been noted in medical literature at least 38 times since 1982 it takes its name from lazarus who in the new testament of the bible was raised from the dead by jesus occurrences of the syndrome are extremely rare and the causes are not well understood one hypothesis for the phenomenon is that a chief factor though not the only one is the buildup of pressure in the chest as a result of cardiopulmonary resuscitation cpr the relaxation of pressure after resuscitation efforts have ended is thought to allow the heart to expand triggering the heart s electrical impulses and restarting the heartbeat other possible factors are hyperkalemia or high doses of epinephrine
lazy inheritance is a design pattern used in javascript computer programming it designates a postponed linking of an object with its prototype class until it is needed if used properly such approach may increase efficiency simplicity and flexibility of oop based code written using javascript since lazy inheritance called only once at the moment of first object instance creation it seems logical to combine process of class prototype creation with resolving necessary dependencies of that class the instances of objects in lazy inheritance are created in mixed mode — on first invocation a factory is used to modify class prototype which is later is used for subsequent object instances creation in other words the process of prototype construction also allows loading scripts if ones were not loaded before which particular class depends on such approach to inheritance support has the following benefits lazy inheritance has the same benefits as classical javascript prototype features it is not necessary to maintain proper order of script files declaration in most cases html page which contains javascript is loaded faster since there are no objects created during page initialization and since some scripts could be loaded only at the moment in which they are actually necessary they are necessary if the caller code during its execution really creates instances of corresponding classes dependencies are declared in more explicit way and class depends only on concrete scripts moreover it s not necessary to artificially group particular scripts into modules and define dependencies between such modules if lazy mode of scripts loading is used only necessary scripts which are actually required for application functionality will be loaded if for example some html page may operate in different modes like read write and read only for every mode required scripts will be loaded and this will be performed automatically without manual script loading optimization
lazy loading is a design pattern commonly used in computer programming to defer initialization of an object until the point at which it is needed it can contribute to efficiency in the program s operation if properly and appropriately used the opposite of lazy loading is eager loading
french secularity french laïcité la isite is the absence of religious involvement in government affairs especially the prohibition of religious influence in the determination of state policies it is also the absence of government involvement in religious affairs especially the prohibition of government influence in the determination of religion dictionaries ordinarily translate laïcité as secularity or secularism the latter being the political system although it is sometimes rendered in english as laicity or laicism by its opponents while the term was first used with this meaning in 1871 in the dispute over the removal of religious teachers and instruction from elementary schools the word laïcité dates to 1842 in its strict and official acceptance it is the principle of separation of church or religion and state etymologically laïcité is a noun formed by adding the suffix ité english ity latin itās to the latin adjective lāicus loanword from the greek λᾱϊκός lāïkós of the people layman the adjective from λᾱός lāós people french secularism has a long history but the current regime is based on the 1905 french law on the separation of the churches and the state
a le fort fracture of the skull is a classic transfacial fracture of the midface involving the maxillary bone and surrounding structures in either a horizontal pyramidal or transverse direction the hallmark of lefort fractures is traumatic pterygomaxillary separation which signifies fractures between the pterygoid plates horseshoe shaped bony protuberances which extend from the inferior margin of the maxilla and the maxillary sinuses continuity of this structure is a keystone for stability of the midface involvement of which impacts surgical management of trauma victims as it requires fixation to a horizontal bar of the frontal bone the pterygoid plates lie posterior to the upper dental row or alveolar ridge when viewing the face from an anterior view the fractures are named after french surgeon rené le fort 1869 – 1951 who discovered the fracture patterns by examining crush injuries in cadavers
in pedology leaching is the loss of mineral and organic solutes due to very heavy rainfall high temperature and percolation it is a mechanism of soil formation distinct from the soil forming process of eluviation which is the loss of mineral and organic colloids leached and elluviated materials tend to be lost from topsoil and deposited in subsoil a soil horizon accumulating leached and eluviated materials is referred to as a zone of illuviation laterite soil which develops in regions with high temperature and heavy rainfall is an example of this process in action
a lead ˈliːd is a large fracture within an expanse of sea ice defining a linear area of open water that can be used for navigation purposes leads vary in width from meters to hundreds of meters as is the case for polynyas another sea ice feature involving open water leads allow the direct interaction between the atmosphere and the ocean and are important for arctic sea ice ecology additionally it has been lately found that ice leads contribute significantly to the amount of mercury deposited onto surface and leaked into the ocean if the air is cold enough typically in the winter the water within a lead quickly refreezes such that in many cases leads are partly or entirely covered by a thin layer of new ice
lead poisoning is a type of metal poisoning caused by lead in the body the brain is the most sensitive symptoms may include abdominal pain constipation headaches irritability memory problems inability to have children and tingling in the hands and feet it causes almost 10 of intellectual disability of otherwise unknown cause and can result in behavioral problems some of the effects are permanent in severe cases anemia seizures coma or death may occur exposure to lead can occur by contaminated air water dust food or consumer products children are at greater risk as they are more likely to put objects in their mouth such as those that contain lead paint and absorb a greater proportion of the lead that they do eat exposure at work is a common cause of lead poisoning in adults with certain occupations at particular risk diagnosis is typically by measurement of the blood lead level the centers for disease control us has set the upper limit for blood lead for adults at 10 µg dl 10 µg 100 g and for children at 5 µg dl elevated lead may also be detected by changes in red blood cells or dense lines in the bones of children as seen on x ray lead poisoning is preventable this includes by individual efforts such as removing lead containing items from the home workplace efforts such as improved ventilation and monitoring and nationwide policies such as laws that ban lead in products such as paint and gasoline reduce allowable levels in water or soil and provide for cleanup of contaminated soil the major treatments are removal of the source of lead and the use of medications that bind lead so it can be eliminated from the body known as chelation therapy chelation therapy in children is recommended when blood levels are greater than 40 45 ug dl medications used include dimercaprol edetate calcium disodium and succimer in 2013 lead is believed to have resulted in 853 000 deaths it occurs most commonly in the developing world those who are poor are at greater risk lead is believed to result in 0 6 of the world s disease burden people have been mining and using lead for thousands of years descriptions of lead poisoning date to at least 2000 bc while efforts to limit leads use date back to at least the 1500 s concerns for low levels of exposure begin in the 1970 s with there being no safe threshold for lead exposure
leaf curl is a plant disease characterized by curling of leaves and caused by a fungus genus taphrina or virus especially genus begomovirus of the family geminiviridae one of the most notable types is peach leaf curl caused by the fungus taphrina deformans which infects peach nectarine and almond trees taphrina deformans is found in america europe asia africa australia and new zealand it was first introduced in america in 1852 and has now spread all over the country
leaf rust is a fungal disease of barley caused by puccinia hordei it is also known as brown rust and it is the most important rust disease on barley
leaky gut syndrome is a hypothetical medically unrecognized condition while increased intestinal permeability leaky gut is a phenomenon recognized by mainstream science claims for the existence of leaky gut syndrome as a distinct medical condition are mostly made by nutritionists and practitioners of alternative medicine proponents claim that a leaky gut causes chronic inflammation throughout the body that results in a wide range of conditions including chronic fatigue syndrome rheumatoid arthritis lupus migraines multiple sclerosis and autism as of 2016 there is little evidence to support the hypothesis that leaky gut syndrome directly causes this wide array of diseases although research is ongoing stephen barrett has described leaky gut syndrome as a fad diagnosis and says that its proponents use the alleged condition as an opportunity to promote a number of alternative health remedies including diets herbal preparations and dietary supplements in 2009 seth kalichman wrote that some pseudoscientists claim that the passage of proteins through a leaky gut is the cause of autism the belief that a leaky gut might actually cause autism is widespread among the public but the evidence is weak and what evidence there is is conflicting various treatments are touted for leaky gut syndrome such as dietary supplements probiotics herbal remedies gluten free foods and low fodmap low sugar or antifungal diets but there is little evidence that the treatments offered are of benefit none have been adequately tested to determine if they are safe and effective for this purpose the national institute for health and care excellence nice does not recommend the use of special diets to manage the main symptoms of autism
the leap year bug also known as the leap year problem is a problem for both digital computer related and non digital documentation and data storage situations which results from the wrong calculation of which years are leap years
learned non use of a limb is a learning phenomenon whereby movement is suppressed initially due to adverse reactions and failure of any activity attempted with the affected limb which then results in the suppression of behavior continuation of this response results in persisting tendency and consequently the individual never learns that the limb may have become potentially useful by constraining the less affected limb there is a change in motivation which overcomes the learned nonuse of the more affected limb the principles of constraint induced movement therapy cimt used in stroke patients are based on the idea of the reversal of learned non use cimt uses constrained movement of the less affected limb and intensive training of the paretic arm to counter condition the nonuse of the more affected arm learned in the acute and early sub acute periods more recently clinical versions of cimt called modified constraint induced movement therapy mcit have been produced that are administered over a longer time period than cimt usually 10 weeks while offering the same effectiveness and cortical changes as cimt these versions are better tolerated and can be integrated into traditional therapy clinics and reimbursement parameters
learning disability is a classification that includes several areas of functioning in which a person has difficulty learning in a typical manner usually caused by an unknown factor or factors given the difficulty learning in a typical manner this does not exclude the ability to learn in a different manner therefore some people can be more accurately described as having a learning difference thus avoiding any misconception of being disabled with a lack of ability to learn and possible negative stereotyping while learning disability learning disorder and learning difficulty are often used interchangeably they differ in many ways disorder refers to significant learning problems in an academic area these problems however are not enough to warrant an official diagnosis learning disability on the other hand is an official clinical diagnosis whereby the individual meets certain criteria as determined by a professional psychologist pediatrician etc the difference is in degree frequency and intensity of reported symptoms and problems and thus the two should not be confused when the term learning disorder is used it describes a group of disorders characterized by inadequate development of specific academic language and speech skills types of learning disorders include reading dyslexia mathematics dyscalculia and writing dysgraphia the unknown factor is the disorder that affects the brain s ability to receive and process information this disorder can make it problematic for a person to learn as quickly or in the same way as someone who is not affected by a learning disability people with a learning disability have trouble performing specific types of skills or completing tasks if left to figure things out by themselves or if taught in conventional ways individuals with learning disabilities can face unique challenges that are often pervasive throughout the lifespan depending on the type and severity of the disability interventions and current technologies may be used to help the individual learn strategies that will foster future success some interventions can be quite simplistic while others are intricate and complex current technologies may require student training to be effective classroom supports teachers parents and schools can create plans together that tailor intervention and accommodations to aid the individuals in successfully becoming independent learners school psychologists and other qualified professionals quite often help design the intervention and coordinate the execution of the intervention with teachers and parents social support may improve the learning for students with learning disabilities
in pottery leather hard is the condition of a clay or clay body when it has been partially dried to the point where all shrinkage has been completed and it has a consistency similar to leather of the same thickness as the clay at this stage the clay object has approximately 15 moisture content the clay is still visibly damp normally a darkish grey if it began whiteish but has dried enough to be able to be handled without deformation the body is able to be gouged or incised without breaking at this stage details such as handles and spouts are often attached to the main body and many forms of decoration including painting may be applied
leber s congenital amaurosis lca is a rare inherited eye disease that appears at birth or in the first few months of life and affects around 1 in 80 000 of the population one form of lca became well known in the scientific community following its successful treatment with gene therapy in 2008 lca was first described by theodor leber in the 19 th century it should not be confused with leber s hereditary optic neuropathy which is a different disease also described by theodor leber
leber ’ s hereditary optic neuropathy lhon or leber optic atrophy is a mitochondrially inherited transmitted from mother to offspring degeneration of retinal ganglion cells rgcs and their axons that leads to an acute or subacute loss of central vision this affects predominantly young adult males lhon is only transmitted through the mother as it is primarily due to mutations in the mitochondrial not nuclear genome and only the egg contributes mitochondria to the embryo lhon is usually due to one of three pathogenic mitochondrial dna mtdna point mutations these mutations are at nucleotide positions 11778 g to a 3460 g to a and 14484 t to c respectively in the nd 4 nd 1 and nd 6 subunit genes of complex i of the oxidative phosphorylation chain in mitochondria men cannot pass on the disease to their offspring
lecithin cholesterol acyltransferase deficiency lcat deficiency is disorder of lipoprotein metabolism lecithin cholesterol acyltransferase catalyzes the formation of cholesterol esters in lipoproteins
the lectin pathway is a type of cascade reaction in the complement system similar in structure to the classical complement pathway in that after activation it proceeds through the action of c 4 and c 2 to produce activated complement proteins further down the cascade in contrast to the classical complement pathway the lectin pathway does not recognize an antibody bound to its target the lectin pathway starts with mannose binding lectin mbl or ficolin binding to certain sugars in this pathway mannose binding lectin binds to mannose glucose or other sugars with 3 and 4 oh groups placed in the equatorial plane in terminal positions on carbohydrate or glycoprotein components of microorganisms including bacteria such as salmonella listeria and neisseria strains fungal pathogens such as candida albicans and cryptococcus neoformans as well as some viruses such as hiv 1 and respiratory syncytial virus rsv are bound by mbl mannan binding lectin also called mannose binding protein is a protein belonging to the collectin family that is produced by the liver and can initiate the complement cascade by binding to pathogen surfaces
leech bites are caused by leeches the class hirudinea which may be of marine freshwater or terrestrial types hand removing a leech is advised since they do not burrow into the skin nor the head in the wound while other texts advice shaking salt onto the body of the leech or scorch the leech with a cigarette or lighter because of the risk of regurgitation and infection other texts advice against these last techniques
leeway is the amount of drift motion to leeward of an object floating in the water caused by the component of the wind vector that is perpendicular to the object ’ s forward motion the national search and rescue supplement to the international aeronautical and maritime search and rescue manual defines leeway as the movement of a search object through water caused by winds blowing against exposed surfaces however the resultant total motion of an object is made up of the leeway drift and the movement of the upper layer of the ocean caused by the surface currents tidal currents and ocean currents objects with a greater exposure to each element will experience more leeway drift and overall movement through the water than ones with less exposure a navigator or pilot on a vessel must adjust the ordered course to compensate for the leeway drift and more important set and drift an all encompassing term for drift that includes the steering error of the vessel failure to make these adjustments during a voyage will yield poor navigational results bowditch s american practical navigator 1995 offers a comprehensive free guide to navigation principles an object can be classified as either an active object like a ship navigating through a waterway or a passive object like a liferaft drifting debris or a person in the water piw figure 3 a passive object will experience the greatest leeway drift and it is this drift that is of utmost importance to those involved in search and rescue sar upon inland waterways and open oceans
the lee – boot effect is a phenomenon concerning the suppression or prolongation of oestrous cycles of mature female mice and other rodents when females are housed in groups and isolated from males it is caused by the effects of an oestrogen dependent pheromone released via the urine that acts on the vomeronasal organ of recipients this pheromone lowers the concentration of luteinizing hormone and elevates prolactin levels synchronising or stopping the recipient ’ s cycle this effect goes some way to explain why spontaneous pseudopregnancy can occur in mice the same response is invoked from isolated females when brought into contact with urine soaked bedding from other females ’ cages removing the vomeronasal organ of recipients causes an ineffective response – indicating that the cues are not mediated by the vomeronasal system
left anterior fascicular block lafb is an abnormal condition of the left ventricle of the heart related to but distinguished from left bundle branch block lbbb it is caused by only the anterior half of the left bundle branch being defective it is manifested on the ecg by left axis deviation it is much more common than left posterior fascicular block
in electrocardiography left axis deviation lad is a condition wherein the mean electrical axis of ventricular contraction of the heart lies in a frontal plane direction between − 30 ° and − 90 ° this is reflected by a qrs complex positive in lead i and negative in leads avf and ii
left bundle branch block lbbb is a cardiac conduction abnormality seen on the electrocardiogram ecg in this condition activation of the left ventricle of the heart is delayed which causes the left ventricle to contract later than the right ventricle
a left posterior fascicular block lpfb is a condition where the left posterior fascicle which travels to the inferior and posterior portion of the left ventricle does not conduct the electrical impulses from the atrioventricular node the wave front instead moves more quickly through the left anterior fascicle and right bundle branch leading to a right axis deviation seen on the ecg the american heart association has defined a lpfb as frontal plane axis between 90 ° and 180 ° in adults rs pattern in leads i and avl qr pattern in leads iii and avf qrs duration less than 120 ms the broad nature of the posterior bundle as well as its dual blood supply makes isolated lpfb rare
left shift or blood shift is an increase in the number of immature leukocytes in the peripheral blood particularly neutrophil band cells less commonly left shift may also refer to a similar phenomenon in severe erythroanemia when reticulocytes and immature erythrocyte precursors appear in the peripheral circulation
left ventricular hypertrophy lvh is thickening of the heart muscle of the left ventricle of the heart that is left sided ventricular hypertrophy
left ventricular thrombus is a blood clot thrombus in the left ventricle of the heart lvt is a common complication of acute myocardial infarction ami typically the clot is a mural thrombus meaning it is on the wall of the ventricle the primary risk of lvt is the occurrence of cardiac embolism in which the thrombus detaches from the ventricular wall and travels through the circulation and blocks blood vessels blockage can be especially damaging in the heart or brain stroke
in number theory the legendre symbol is a multiplicative function with values 1 − 1 0 that is a quadratic character modulo a prime number p its value on a nonzero quadratic residue mod p is 1 and on a non quadratic residue non residue is − 1 its value on zero is 0 the legendre symbol was introduced by adrien marie legendre in 1798 in the course of his attempts at proving the law of quadratic reciprocity generalizations of the symbol include the jacobi symbol and dirichlet characters of higher order the notational convenience of the legendre symbol inspired introduction of several other symbols used in algebraic number theory such as the hilbert symbol and the artin symbol
legg – calvé – perthes disease lcpd is a childhood hip disorder initiated by a disruption of blood flow to the ball of the femur called the femoral head due to the lack of blood flow the bone dies osteonecrosis or avascular necrosis and stops growing over time healing occurs by new blood vessels infiltrating the dead bone and removing the necrotic bone which leads to a loss of bone mass and a weakening of the femoral head the bone loss leads to some degree of collapse and deformity of the femoral head and sometimes secondary changes to the shape of the hip socket it is also referred to as idiopathic avascular osteonecrosis of the capital femoral epiphysis of the femoral head since the cause of the interruption of the blood supply of the head of the femur in the hip joint is unknown the condition is most commonly found in children between the ages of 4 and 8 but it can occur in children between the ages of 2 and 15 the main long term problem with this condition is that it can produce a permanent deformity of the femoral head which increases the risk of developing osteoarthritis in adults it is also commonly known as perthes disease or legg – perthes disease perthes is a form of osteochondritis which only affects the hip although other forms of osteochondritis can affect elbows knees ankles and feet bilateral perthes which means both hips are affected should always be investigated thoroughly to rule out multiple epiphyseal dysplasia the name originated from arthur legg 1874 1939 an american orthopedic surgeon jacques calvé 1875 1954 french orthopedic surgeon and georg perthes german orthopedic surgeon the disease name was first described by karel maydl
legionnaires disease is a form of atypical pneumonia caused by any type of legionella bacteria signs and symptoms include cough shortness of breath high fever muscle pains and headaches nausea vomiting and diarrhea may also occur this often begins two to ten days after being exposed the bacterium is found naturally in fresh water it can contaminate hot water tanks hot tubs and cooling towers of large air conditioners it is usually spread by breathing in mist that contains the bacteria it can also occur when contaminated water is aspirated it typically does not spread directly between people and most people who are exposed do not become infected risk factors for infection include older age history of smoking chronic lung disease and poor immune function it is recommended that those with severe pneumonia and those with pneumonia and a recent travel history be tested for the disease diagnosis is by a urinary antigen test and sputum culture there is no vaccine prevention depends on good maintenance of water systems treatment of legionnaires disease is with antibiotics recommended agents include fluoroquinolones azithromycin or doxycycline hospitalization is often required about 10 of those who are infected die the number of cases that occur globally is not known it is estimated that legionnaires disease is the cause of between two and nine percent of pneumonia cases that occur in the community there are an estimated 8 000 to 18 000 cases a year in the united states that require hospitalization outbreaks of disease account for a minority of cases while it can occur any time of the year it is more common in the summer and fall the disease is named after the outbreak where it was first identified the 1976 american legion convention in philadelphia
legius syndrome ls is an autosomal dominant condition characterized by cafe au lait spots it was first described in 2007 and is often mistaken for neurofibromatosis type i nf 1 it is caused by mutations in the spred 1 gene it is also known as neurofibromatosis type 1 like syndrome nfls the syndrome is named after eric legius professor at the ku leuven it is a rasopathy
the lehmann discontinuity is an abrupt increase of p wave and s wave velocities at the depth of 220 ± 30 km discovered by seismologist inge lehmann it appears beneath continents but not usually beneath oceans and does not readily appear in globally averaged studies several explanations have been proposed a lower limit to the pliable asthenosphere a phase transition and most plausibly depth variation in the shear wave anisotropy further discussion of the lehmann discontinuity can be found in the book deformation of earth materials by shun ichirō karato
leibermuster is a six color military camouflage pattern developed by the german military in february 1945 it was the last of a family of german world war ii camouflage patterns known in german as buntfarbenaufdruck 45 multi colour print pattern 45 for its year of introduction leibermuster named after the brothers leiber the pattern s creators was issued on a very limited basis to combat units before the war ended it was the first pattern issued to both regular army wehrmacht and waffen ss units the pattern consists of black brown olive pale green white and red reproduction leibermuster uniforms created for collectors and reenactors have become available on the market through european vendors reproductions are made in china and turkey
the leidenfrost effect is a physical phenomenon in which a liquid in near contact with a mass significantly hotter than the liquid s boiling point produces an insulating vapor layer keeping that liquid from boiling rapidly due to this ‘ repulsive force ’ a droplet hovers over the surface rather than making physical contact with it this is most commonly seen when cooking one sprinkles drops of water in a pan to gauge its temperature if the pan s temperature is at or above the leidenfrost point the water skitters across the pan and takes longer to evaporate than in a pan below the temperature of the leidenfrost point but still above boiling temperature the effect is also responsible for the ability of liquid nitrogen to skitter across floors it has also been used in some potentially dangerous demonstrations such as dipping a wet finger in molten lead or blowing out a mouthful of liquid nitrogen both enacted without injury to the demonstrator the latter is potentially lethal particularly should one accidentally swallow the liquid nitrogen it is named after johann gottlob leidenfrost who discussed it in a tract about some qualities of common water in 1756 johann gottlob leidenfrost was born on november 27 1715 in rosperwenda in the county of stolberg stolberg germany his father johann heinrich leidenfrost was a well known minister little is known of leidenfrost s life prior to the start of his academic career
leigh disease is a rare inherited neurometabolic disorder that affects the central nervous system it is named after archibald denis leigh a british neuropsychiatrist who first described the condition in 1951
leiner s disease is a systemic disease a skin disorder and extends to erythroderma typically diagnosed in early infancy leiner ’ s disease is characterized by a long lasting seborrhea dermatitis associated with increased likelihood to infection other characterizations found on newborns with leiner ’ s disease are a patch or a large patch of red skin normally on the bottom and spreads to the rest of the body this disease is also listed as a rare disease meaning that a small percent of the population less than 200 000 people in the united states will have this disorder
a leiomyoma also known as fibroids is a benign smooth muscle tumor that very rarely becomes cancer 0 1 they can occur in any organ but the most common forms occur in the uterus small bowel and the esophagus polycythemia may occur due to increased erythropoietin production as part of a paraneoplastic syndrome the word is from leio myo oma smooth muscle tumor
leiomyosarcoma gr smooth muscle connective tissue tumor also referred to as lms is a malignant cancerous smooth muscle tumor it must not be confused with leiomyoma which is a benign tumor originating from the same tissue it is also important to note that leiomyosarcomas do not arise from leiomyomas leiomyosarcoma is an extremely rare form of cancer and accounts for 5 – 10 of soft tissue sarcomas which are in themselves relatively rare leiomyosarcomas can be very unpredictable they can remain dormant for long periods of time and recur after years it is a resistant cancer meaning generally not very responsive to chemotherapy or radiation the best outcomes occur when it can be removed surgically with wide margins early while small and still in situ
leishmaniasis also spelled leishmaniosis is a disease caused by protozoan parasites of the genus leishmania and spread by the bite of certain types of sandflies the disease can present in three main ways cutaneous mucocutaneous or visceral leishmaniasis the cutaneous form presents with skin ulcers while the mucocutaneous form presents with ulcers of the skin mouth and nose and the visceral form starts with skin ulcers and then later presents with fever low red blood cells and enlarged spleen and liver infections in humans are caused by more than 20 species of leishmania risk factors include poverty malnutrition deforestation and urbanization all three types can be diagnosed by seeing the parasites under the microscope additionally visceral disease can be diagnosed by blood tests leishmaniasis can be partly prevented by sleeping under nets treated with insecticide other measures include spraying insecticides to kill sandflies and treating people with the disease early to prevent further spread the treatment needed is determined by where the disease is acquired the species of leishmania and the type of infection some possible medications used for visceral disease include liposomal amphotericin b a combination of pentavalent antimonials and paromomycin and miltefosine for cutaneous disease paromomycin fluconazole or pentamidine may be effective about 12 million people are currently infected in some 98 countries about 2 million new cases and between 20 and 50 thousand deaths occur each year about 200 million people in asia africa south and central america and southern europe live in areas where the disease is common the world health organization has obtained discounts on some medications to treat the disease the disease may occur in a number of other animals including dogs and rodents
a lekythion or lecythion in classical greek and latin poetry is a metric pattern colon defined by a sequence of seven alternating long and short syllables at the end of a verse — ∨ — ⊻ — ∨ — in classical grammatical terminology it can be described as a trochaic dimeter catalectic i e a combination of two groups of two trochees each — ∨ — ⊻ with the second of these groups lacking its final syllable or as a trochaic hepthemimer i e a trochaic sequence of seven half feet a lekythion can appear in several different metric contexts in different types of poetry either alone as a verse or as the second of two cola following a caesura a frequent type of occurrence in greek drama is in lines of iambic trimeter the most frequent metre used in spoken dialogue i e lines of the type ⊻ — ∨ — ⊻ — ∨ — ⊻ — ∨ — these lines may have a metric caesura after the first five syllables with the remaining line thus resulting in a lekythion group
lelis syndrome it is a genetic disorder a rare condition with dermatological and dental findings characterized by the association of ectodermal dysplasia hypotrichosis and hypohidrosis with acanthosis nigricans other clinical features may include palmoplantar hyperkeratosis nail dystrophy intellectual deficit disturbances of skin pigmentation perioral and periorbital hyperpigmentation vitiligo and perinevic leukoderma and hypodontia transmission is autosomal recessive
lemierre s syndrome or lemierre s disease also known as postanginal shock including sepsis and human necrobacillosis refers to thrombophlebitis of the internal jugular vein it most often develops as a complication of a bacterial sore throat infection in young otherwise healthy adults the thrombophlebitis is a serious condition and may lead to further systemic complications such as bacteria in the blood or septic emboli lemierre s syndrome occurs most often when a bacterial e g fusobacterium necrophorum throat infection progresses to the formation of a peritonsillar abscess deep in the abscess anaerobic bacteria can flourish when abscess wall ruptures internally the drainage carrying bacteria seeps through the soft tissue and infects the nearby structures spread of infection to the nearby jugular vein provides a gateway for the spread of bacteria through the bloodstream the inflammation surrounding the vein and compression of the vein may lead to clot formation pieces of the potentially infected clot break off and travel through the right heart onto the lungs as emboli blocking branches of the pulmonary artery that carry deoxygenated blood from the heart to the lungs sepsis following from a throat infection was described by schottmuller in 1918 however it was andré lemierre in 1936 who published a series of 20 cases where throat infections were followed by identified anaerobic septicemia of whom 18 patients died
the lemieux – johnson oxidation is a chemical reaction in which an olefin undergoes oxidative cleavage to form two aldehyde or ketone units the reaction is named after its inventors r u lemieux and w s johnson who published it in 1956 the reaction proceeds in a two step manner beginning with dihydroxylation of the alkene by osmium tetroxide followed by oxidative cleavage by periodate excess periodate is used to regenerate the osmium tetroxide allowing it to be used in catalytic amounts the lemieux – johnson reaction ceases at the aldehyde stage of oxidation and therefore produces the same results as ozonolysis the classical lemieux – johnson oxidation often generates many side products resulting in low reaction yields however the addition of non nucleophilic bases such as 2 6 lutidine can improve on this oso 4 may be replaced with a number of other osmium compounds periodate may also be replaced with other oxidising agents such as oxone
in mathematics lemoine s problem is a certain construction problem in elementary plane geometry posed by the french mathematician émile lemoine 1840 – 1912 in 1868 the problem was published as question 864 in nouvelles annales de mathématiques series 2 volume 7 1868 p 191 the chief interest in the problem is that a discussion of the solution of the problem by ludwig kiepert published in nouvelles annales de mathématiques series 2 volume 8 1869 pp 40 – 42 contained a description of a hyperbola which is now known as the kiepert hyperbola
in mathematical field of geometric group theory a length function is a function that assigns a number to each element of a group
lennert lymphoma also known as lymphoepithelioid lymphoma is a systemic t cell lymphoma that presents with cutaneous skin lesions roughly 10 of the time it is also known as lymphoepithelioid variant of peripheral t cell lymphoma it was first characterized in 1952
lennox – gastaut syndrome lgs is a difficult to treat form of childhood onset epilepsy that most often appears between the second and sixth year of life lgs is characterized by a triad of signs including frequent seizures of multiple types an abnormal eeg pattern of less than 2 5 hz slow spike wave activity and moderate to severe intellectual impairment
lens sag is a problem that sometimes afflicts very large refracting telescopes it is the equivalent of mirror sag in reflecting telescopes it occurs when the physical weight of the glass causes a distortion in the shape of the lens because the lens can only be supported by the edges a mirror on the other hand can be effectively supported by the entire opposite face making mirror sag much less of a problem one expensive solution to lens sag is to place the telescope in orbit around the earth the technical limit concerning lens sag was reached at the yerkes refractor 1897 with an aperture of 40 102 cm where the sagging already causes small optical distortions the 1890 s therefore mark the end of the great refractors era
lenticonus len · ti · co · nus len ″ tĭ ko ´ nus lens l conus cone is a rare congenital anomaly of the eye characterized by a conical protrusion on the crystalline lens capsule and the underlying cortex it can reach a diameter of 2 to 7 mm the conus may occur anteriorly or posteriorly if the bulging is spherical instead of conical the condition is referred to as lentiglobus it produces a decrease in visual acuity and irregular refraction that cannot be corrected by either spectacle or contact lenses biomicroscopically lenticonus is characterized by a transparent localized sharply demarcated conical projection of the lens capsule and cortex usually axial in localization in an early stage retro illumination shows an « oil droplet » configuration using a narrow slit the image of a conus is observed in a more advanced stage associated subcapsular and cortical opacities appear retinoscopically the oil droplet produces a pathognomonic scissors movement of the light reflex this phenomenon is due to the different refraction in the central and the peripheral area of the lens ultrasonography also can illustrate the existence of a lenticonus a scan ultrasonography may reveal an increased lens thickness and b scanultrasonography may show herniated lenticular material suggestive of a lenticonus amblyopia cataract strabismus and loss of central fixation may be observed in association with lenticonus posterior cataract flecked retinopathy posterior polymorphous dystrophy and corneal arcus juvenilis may be encountered in association with lenticonus anterior that occurs as a part of the alport syndrome exist two distinct types of lenticonus based on the face of the lens affected
lenticular bedding is a sedimentary bedding pattern displaying alternating layers of mud and sand formed during periods of slack water mud suspended in the water is deposited on top of small formations of sand once the water s velocity has reached zero lenticular bedding is classified by its large quantities of mud relative to sand whereas a flaser bed consists mostly of sand the sand formations within the bedding display a lens like shape giving the pattern its respected name they are commonly found in high energy environments such as the intertidal and supratidal zones geologists use lenticular bedding to show evidence of tidal rhythm tidal currents and tidal slack in a particular environment
lentiginosis refers to the presence of lentigines in large numbers or in a distinctive configuration these are spotted areas created by accumulation on the skin due to sun exposure due to a high irregularity any distinction from randomness defines lentiginosis although lentigines are benign they be the signal of an underlying problem such as progressive cardiomyopathic lentiginosis which can cause retardation in children
a lentigo lɛnˈtaɪɡoʊ plural lentigines lɛnˈtɪdʒᵻniz is a small pigmented spot on the skin with a clearly defined edge surrounded by normal appearing skin it is a harmless benign hyperplasia of melanocytes which is linear in its spread this means the hyperplasia of melanocytes is restricted to the cell layer directly above the basement membrane of the epidermis where melanocytes normally reside this is in contrast to the nests of multi layer melanocytes found in moles melanocytic nevi because of this characteristic feature the adjective lentiginous is used to describe other skin lesions that similarly proliferate linearly within the basal cell layer lentigines are distinguished from freckles ephelis based on the proliferation of melanocytes freckles have a relatively normal number of melanocytes but an increased amount of melanin a lentigo has an increased number of melanocytes freckles will increase in number and darkness with sunlight exposure whereas lentigines will stay stable in their color regardless of sunlight exposure conditions characterized by lentigines include lentigo simplex solar lentigo liver spots puva lentigines ink spot lentigo leopard syndrome mucosal lentigines multiple lentigines syndrome moynahan syndrome generalized lentiginosis centrofacial lentiginosis carney complex inherited patterned lentiginosis in black persons partial unilateral lentiginosis peutz jeghers syndrome lentigo maligna lentigo maligna melanoma acral lentiginous melanoma
lentigo maligna also known as lentiginous melanoma on sun damaged skin is a melanoma in situ that consists of malignant cells but does not show invasive growth lentigo maligna is not the same as lentigo maligna melanoma and should be discussed separately it typically progresses very slowly and can remain in a non invasive form for years the transition to true melanoma is marked by the appearance of a bumpy surface itself a marker of vertical growth and invasion at which point it is called lentigo maligna melanoma it is normally found in the elderly peak incidence in the 9 th decade on skin areas with high levels of sun exposure like the face and forearms some authors do not consider lentigo maligna to be a melanoma it is commonly thought of as a melanoma precursor incidence of evolution to lentigo maligna melanoma is very low about 2 2 to 5 in elderly patients it is also known as hutchinson s melanotic freckle this is named for jonathan hutchinson
lentigo maligna melanoma is a melanoma that has evolved from a lentigo maligna they are usually found on chronically sun damaged skin such as the face and the forearms of the elderly the nomenclature is very confusing to both patients and physicians alike lentigo maligna is the non invasive skin growth that some pathologists consider to be a melanoma in situ a few pathologists do not consider lentigo maligna to be a melanoma at all but a precursor to melanomas once a lentigo maligna becomes a lentigo maligna melanoma it is treated as if it were an invasive melanoma
lentigo simplex also known as simple lentigo is the most common form of lentigo a single lesion or multiple lesions lentigines may be present at birth or more commonly first develop in early childhood lentigo simplex is not induced by sun exposure and it is not associated with any medical diseases or conditions it is also referred to as simple lentigo and juvenile lentigo this condition also affects cats those with orange coloration most often and can appear on the nose lips and eyes as the cat ages
lenz – majewski syndrome is a skin condition characterized by hyperostosis craniodiaphyseal dysplasia dwarfism cutis laxa proximal symphalangism syndactyly brachydactyly mental retardation enamel hypoplasia and hypertelorism in 2013 whole exome sequencing showed that a missense mutation resulting in overactive phosphatidylserine synthase 1 was the cause of lms making it the first known human disease to be caused by disrupted phosphatidylserine metabolism the researchers suggested a link between the condition and bone metabolism
leo soileau january 19 1904 – august 2 1980 was one of the most prolific cajun recording artists of the 1930 s and 1940 s recording over 100 songs which was a substantial amount considering the reluctance to record the music during its early stages he is known as the second person to record a cajun record and the first to record this genre with a fiddle
leontiasis ossea also known as leontiasis lion face or lion face syndrome is a rare medical condition characterized by an overgrowth of the facial and cranial bones it is not a disease in itself but a symptom of other diseases including paget s disease fibrous dysplasia hyperparathyroidism and renal osteodystrophy the common form is that in which one or other maxilla is affected its size progressively increasing and thus encroaching on the cavities of the orbit the mouth the nose and its accessory sinuses exophthalmos gradually develops going on later to a complete loss of sight due to compression of the optic nerve by the overgrowth of bone there may also be interference with the nasal respiration and with the taking of food in the somewhat less common form of this rare disease the overgrowth of bone affects all the cranial bones as well as those of the face the senses being lost one by one and death finally resulting from cerebral pressure there is no treatment other than exposing the overgrown bone and chipping away pieces or excising entirely where possible
a leopard pattern is a spotted color pattern particularly in the hair coat or skin of animals but can also describe spotting patterns in plants and fabrics the term refers to the black and gold spotted coat of the leopard cat but is used to describe many color combinations that result in spots scattered randomly across the skin or hair coat of other animals examples of animals with coloring patterns termed leopard include many great cats in the panthera genus the leopard frog the leopard spotting pattern in the appaloosa and knabstrupper breeds of horses the leopard seal insects such as the giant leopard moth and fish species such as the leopard darter and the leopard shark examples of plants that use the term include the leopard lily and the leopard flower the lp leopard complex gene is responsible for the leopard color pattern in horses which not only produces a spotted coat color but also causes mottling of the skin a white sclera around the eye and striped hooves horses with the lp gene may be spotted all over or may have concentrations of spots in various patterns
lepidopterism is an irritant contact dermatitis caused by irritating caterpillar or moth hairs coming into contact with the skin or mucosa when referring to the cause moth dermatitis and caterpillar dermatitis are commonly used caripito itch known as papillonite in french is an older name referring to the moth dermatitis caused by some hylesia species
lepromatous leprosy is a skin condition consisting of pale macules it results from the failure of th 1 cell activation which is necessary to eradicate the mycobacteria th 1 response is required to activate macrophages that engulf and contain the disease in lepromatous leprosy th 2 response is turned on and because of reciprocal inhibition il 4 il 10 the cell mediated response th 1 is depressed this debilitating form of leprosy begins to spread causing the eyebrows to disappear and spongy tumor like swellings appear on the face and body the disease attacks the internal organs bones joints and marrow of the body resulting in physical degeneration the result is deformity with loss of feeling in the fingers and toes which eventually fall off contrary to popular belief both forms of leprosy are curable with the lepromatous form classically treated with antibiotics dapsone rifampin and clofazimine for as long as 2 – 5 years but if left untreated the person may die up to 20 or 30 years from its inception early detection of the disease is of utmost importance since severe physical and neurological damage are irreversible even if cured e g blindness loss of digits limbs sensation early infection is characterized by a well demarcated usually pale skin lesion which has lost its hair and there may be many of these lesions if the infection is more severe most commonly found on the cooler parts of the body such as the elbows knees fingers or scrotum as the bacteria thrive in cooler environments this early presentation is the same for both tuberculous and lepromatous forms of leprosy as they are a spectrum of the same disease lepromatous being the more contagious and severe form in patients with impaired th 1 response disease progression is extremely slow and signs of infection may not appear for years family members and especially children who have family members with the disease are most at risk the disease is believed to be spread through respiratory droplets in close quarters like its relative mycobacterium tuberculosis and similarly requires extended exposure to an individual in most situations so outsiders and healthcare workers are normally not infected except with the most infective individuals such as those in the most progressed lepromatous forms as those patients have the highest bacterial loads
leprosy also known as hansen s disease hd is a long term infection caused by the bacilli mycobacterium leprae and mycobacterium lepromatosis initially infections are without symptoms and typically remain this way for 5 to 20 years symptoms that develop include granulomas of the nerves respiratory tract skin and eyes this may result in a lack of ability to feel pain and thus loss of parts of extremities due to repeated injuries or infection due to unnoticed wounds weakness and poor eyesight may also be present leprosy is spread between people this is believed to occur through a cough or contact with fluid from the nose of an infected person leprosy occurs more commonly among those living in poverty contrary to popular belief it is not highly contagious the two main types of disease are based on the number of bacteria present paucibacillary and multibacillary the two types are differentiated by the number of poorly pigmented numb skin patches present with paucibacillary having five or fewer and multibacillary having more than five the diagnosis is confirmed by finding acid fast bacilli in a biopsy of the skin or by detecting the dna using polymerase chain reaction leprosy is curable with a treatment known as multidrug therapy treatment for paucibacillary leprosy is with the medications dapsone and rifampicin for six months treatment for multibacillary leprosy consists of rifampicin dapsone and clofazimine for 12 months a number of other antibiotics may also be used these treatments are provided free of charge by the world health organization globally in 2012 the number of chronic cases of leprosy was 189 000 down from some 5 2 million in the 1980 s the number of new cases was 230 000 most new cases occur in 16 countries with india accounting for more than half in the past 20 years 16 million people worldwide have been cured of leprosy about 200 cases are reported per year in the united states leprosy has affected humanity for thousands of years the disease takes its name from the latin word lepra which means scaly while the term hansen s disease is named after the physician gerhard armauer hansen separating people by placing them in leper colonies still occurs in places such as india china and africa however most colonies have closed since leprosy is not very contagious social stigma has been associated with leprosy for much of history which continues to be a barrier to self reporting and early treatment some consider the word leper offensive preferring the phrase person affected with leprosy world leprosy day was started in 1954 to draw awareness to those affected by leprosy
leptomeningeal cancer is a tumor that involves the two innermost meninges thin layers of tissue that cover and protect the brain and spinal cord
leptospirosis is an infection caused by corkscrew shaped bacteria called leptospira signs and symptoms can range from none to mild such as headaches muscle pains and fevers to severe with bleeding from the lungs or meningitis if the infection causes the person to turn yellow have kidney failure and bleeding it is then known as weil s disease if it causes lots of bleeding from the lungs it is known as severe pulmonary hemorrhage syndrome up to 13 different genetic types of leptospira may cause disease in humans it is transmitted by both wild and domestic animals the most common animals that spread the disease are rodents it is often transmitted by animal urine or by water or soil containing animal urine coming into contact with breaks in the skin eyes mouth or nose in the developing world the disease most commonly occurs in farmers and poor people who live in cities in the developed world it most commonly occurs in those involved in outdoor activities in warm and wet areas of the world diagnosis is typically by looking for antibodies against the bacterium or finding its dna in the blood efforts to prevent the disease include protective equipment to prevent contact when working with potentially infected animals washing after this contact and reducing rodents in areas people live and work the antibiotic doxycycline when used in an effort to prevent infection among travellers is of unclear benefit vaccines for animals exist for certain type of leptospira which may decrease the risk of spread to humans treatment if infected is with antibiotics such as doxycycline penicillin or ceftriaxone weil s disease and severe pulmonary haemorrhage syndrome result in death rates greater than 10 and 50 respectively even with treatment it is estimated that seven to ten million people are infected by leptospirosis a year the number of deaths this causes is not clear the disease is most common in tropical areas of the world but may occur anywhere outbreaks may occur in slums of the developing world the disease was first described by physician adolf weil in 1886 in germany animals which are infected may have no symptoms mild symptoms or severe symptoms symptoms may vary by the type of animal in some animals leptospira live in the reproductive tract leading to transmission during mating
in mathematics the lerch zeta function sometimes called the hurwitz – lerch zeta function is a special function that generalizes the hurwitz zeta function and the polylogarithm it is named after the czech mathematician mathias lerch
leri s pleonosteosis is a rare rheumatic condition it was first described by the french physician leri in 1921
leschke syndrome is a condition characterized by growth retardation and intellectual disability the syndrome is named after german internist erich leschke
lesch – nyhan syndrome lns also known as nyhan s syndrome and juvenile gout is a rare inherited disorder caused by a deficiency of the enzyme hypoxanthine guanine phosphoribosyltransferase hgprt produced by mutations in the hprt gene located on the x chromosome lns affects about one in 380 000 live births the disorder was first recognized and clinically characterized by medical student michael lesch and his mentor pediatrician william nyhan who published their findings in 1964 the hgprt deficiency causes a build up of uric acid in all body fluids this results in both hyperuricemia and hyperuricosuria associated with severe gout and kidney problems neurological signs include poor muscle control and moderate intellectual disability these complications usually appear in the first year of life beginning in the second year of life a particularly striking feature of lns is self mutilating behaviors characterized by lip and finger biting neurological symptoms include facial grimacing involuntary writhing and repetitive movements of the arms and legs similar to those seen in huntington s disease the etiology of the neurological abnormalities remains unknown because a lack of hgprt causes the body to poorly utilize vitamin b 12 some boys may develop megaloblastic anemia lns is an x linked recessive disease the gene mutation is usually carried by the mother and passed on to her son although one third of all cases arise de novo from new mutations and do not have a family history lns is present at birth in baby boys most but not all persons with this deficiency have severe mental and physical problems throughout life there are a few rare cases in the world of affected females the symptoms caused by the buildup of uric acid gout and renal symptoms respond well to treatment with drugs such as allopurinol that reduce the levels of uric acid in the blood the mental deficits and self mutilating behavior do not respond well to treatment there is no cure but many patients live to adulthood several new experimental treatments may alleviate symptoms
the leser trélat sign is the explosive onset of multiple seborrheic keratoses many pigmented skin lesions often with an inflammatory base this can be an ominous sign of internal malignancy as part of a paraneoplastic syndrome in addition to the development of new lesions preexisting ones frequently increase in size and become symptomatic
lethal acantholytic epidermolysis bullosa is a cutaneous condition characterized by generalized erosions at birth
lethal arthrogryposis with anterior horn cell disease laahd is an autosomal recessive genetic disorder characterized by reduced mobility of the foetus and early death
lethal congenital contracture syndrome 1 lccs 1 also called multiple contracture syndrome finnish type is an autosomal recessive genetic disorder characterized by total immobility of a fetus detectable at around the 13 th week of pregnancy lccs 1 invariably leads to prenatal death before the 32 nd gestational week lccs 1 is one of 40 finnish heritage diseases it was first described in 1985 and since then approximately 70 cases have been diagnosed
lethal midline granuloma is a condition affecting the nose and palate the preferred modern term is ulcerating midline lymphoma as it is by no means always lethal when treated in time it has been suggested that the term is confusing and obsolete it is sometimes considered to be part of a spectrum with granulomatosis with polyangiitis it is considered a form of extranodal nk t cell lymphoma
lethal white syndrome lws also called overo lethal white syndrome olws lethal white overo lwo and overo lethal white foal syndrome olwfs is an autosomal genetic disorder most prevalent in the american paint horse affected foals are born after the full 11 month gestation and externally appear normal though they have all white or nearly all white coats and blue eyes however internally these foals have a nonfunctioning colon within a few hours signs of colic appear affected foals die within a few days because the death is often painful such foals often are humanely euthanized once identified the disease is particularly devastating because foals are born seemingly healthy after being carried to full term the disease has a similar etiology to hirschsprung s disease in humans a mutation in the middle of the endothelin receptor type b ednrb gene causes lethal white syndrome when homozygous carriers who are heterozygous — that is have one copy of the mutated allele but themselves are healthy — can now be reliably identified with a dna test both parents must be carriers of one copy of the lws allele in order for an affected foal to be born horses that are heterozygous for the gene that causes lethal white syndrome often exhibit a spotted coat color pattern commonly known as frame or frame overo coat color alone does not always indicate the presence of lws or carrier status however the frame pattern may be minimally expressed or masked by other spotting patterns there also are different genetic mechanisms which produce healthy white foals and have no connection to lws another reason for genetic testing of potential breeding stock though there is no treatment or cure for lws foals a white foal without lws that appears ill may have a treatable condition
lethal yellowing is a phytoplasma disease that attacks many species of palms including some commercially important species such as the coconut and date palm in caribbean it is spread by the planthopper haplaxius crudus former name myndus crudus which is native to florida parts of the caribbean and central america the only effective cure is prevention i e planting resistant varieties of coconut palm and preventing a park or golf course like environments which attracts the planthopper some cultivars such as the jamaica tall coconut cultivar nearly died out by lethal yellowing heavy turf grasses and similar green ground cover will attract the planthopper to lay its eggs and the nymphs develop at the roots of these grasses the planthoppers eggs and nymphs may pose a great threat to coconut growing countries economies into which grass seeds for golf courses and lawns are imported from the americas it is not clearly understood how the disease was spread to east africa as the planthopper haplaxius crudus is not native in east africa the only explanation is that it was imported with grass seed from florida that were used to create golf courses and lawns in beach resorts there is a direct connection between green lawns and the spread of lethal yellowing in florida even so called resistant cultivars such as the malayan dwarf or the maypan hybrid between that dwarf and the panama tall were never claimed to have a 100 immunity the nymphs of the planthoppers develop on roots of grasses hence the areas of grass in the vicinity of palm trees is connected with the spread of this phytoplasma disease the problem arose as a direct result of using coconut and date palms for ornamental and landscaping purposes in lawns golf courses and gardens together with these grasses when these two important food palms were grown in traditional ways without grasses in plantations and along the shores the palm groves weren t noticeably affected by lethal yellowing there is no evidence that disease can be spread when instruments used to cut an infected palm are then used to cut or trim a healthy one seed transmission has never been demonstrated although the phytoplasma can be found in coconut seednuts but phytosanitary quarantine procedures that prevent movement of coconut seed seedlings and mature palms out of an ly epidemic area should be applied to grasses and other plants that may be carrying infected vectors beside coconut palm cocus nucifera more than 30 palm species have also been reported as susceptible to lethal phytoplasmas around the globe in mozambique coconut lethal yellowing has recently been associated with african oil palm elaeis guineensis and fan palm borassus aethiopum
letterer – siwe disease is an old name for langerhans cell histiocytosis lch from a time when lch was thought to be several different diseases letterer – siwe disease hand schuller christian disease eosinophilic granuloma and hashimoto pritzker disease later they were all put together under the name histiocytosis x the x was found to be the langerhans cell a dendritic white blood cell lch is not believed to be genetic even though there have been a few reports of more than one person affected by lch within the same family still to this day the cause is unknown after researchers have worked very hard on trying to figure it out for decades the old name letterer siwe disease is derived from the names of erich letterer and sture siwe
the letts nitrile synthesis is a chemical reaction of aromatic carboxylic acids with metal thiocyanates to form nitriles the reaction includes the loss of carbon dioxide and potassium hydrosulfide the polar basic substitution reaction was discovered in 1872 by edmund a letts the letts nitrile synthesis
leucism ˈljuːkɪzəm or ˈluːsɪzəm is a condition in which there is partial loss of pigmentation in an animal resulting in white pale or patchy coloration of the skin hair feathers scales or cuticle but not the eyes unlike albinism it is caused by a reduction in multiple types of pigment not just melanin
the leuckart reaction is the chemical reaction that converts aldehydes or ketones to amines by reductive amination in the presence of heat the reaction named after rudolf leuckart proceeds via two mechanisms one using ammonium formate and the other using formamide as the reducing agent it requires high temperatures usually between 120 and 130 ° c although under the presence of formamide the temperature can be greater than 165 ° c the reaction works best using ammonium formate and the general reaction can be seen below
leucosis is a leukemia like malignant viral disease that is found in animals particularly poultry and cattle
leucostoma canker is a fungal disease that can kill stone fruit prunus spp the disease is caused by the plant pathogens leucostoma persoonii and leucostoma cinctum teleomorph and cytospora leucostoma and cytospora cincta anamorphs the disease can have a variety of signs and symptoms depending on the part of the tree infected one of the most lethal symptoms of the disease are the leucostoma cankers the severity of the leucostoma cankers is dependent on the part of the plant infected the fungus infects through injured dying or dead tissues of the trees disease management can consist of cultural management practices such as pruning late season fertilizers or chemical management through measures such as insect control leucostoma canker of stone fruit can cause significant economic losses due to reduced fruit production or disease management practices it is one of the most important diseases of stone fruit tree all over the world
leukemia also spelled leukaemia is a group of cancers that usually begin in the bone marrow and result in high numbers of abnormal white blood cells these white blood cells are not fully developed and are called blasts or leukemia cells symptoms may include bleeding and bruising problems feeling tired fever and an increased risk of infections these symptoms occur due to a lack of normal blood cells diagnosis is typically made by blood tests or bone marrow biopsy the exact cause of leukemia is unknown different kinds of leukemia are believed to have different causes both inherited and environmental non inherited factors are believed to be involved risk factors include smoking ionizing radiation some chemicals such as benzene prior chemotherapy and down syndrome people with a family history of leukemia are also at higher risk there are four main types of leukemia — acute lymphoblastic leukemia all acute myeloid leukemia aml chronic lymphocytic leukemia cll and chronic myeloid leukemia cml — as well as a number of less common types leukemias and lymphomas both belong to a broader group of tumors that affect the blood bone marrow and lymphoid system known as tumors of the hematopoietic and lymphoid tissues treatment may involve some combination of chemotherapy radiation therapy targeted therapy and bone marrow transplant in addition to supportive care and palliative care as needed certain types of leukemia may be managed with watchful waiting the success of treatment depends on the type of leukemia and the age of the person outcomes have improved in the developed world the average five year survival rate is 57 in the united states in children under 15 the five year survival rate is greater than 60 to 85 depending on the type of leukemia in children with acute leukemia who are cancer free after five years the cancer is unlikely to return in 2012 leukemia developed in 352 000 people globally and caused 265 000 deaths it is the most common type of cancer in children with three quarters of leukemia cases in children being the acute lymphoblastic type however about 90 of all leukemias are diagnosed in adults with aml and cll being most common in adults it occurs more commonly in the developed world
leukemia cutis is the infiltration of neoplastic leukocytes or their precursors into the skin resulting in clinically identifiable cutaneous lesions this condition may be contrasted with leukemids which are skin lesions that occur with leukemia but which are not related to leukemic cell infiltration leukemia cutis can occur in most forms of leukemia including chronic myeloid leukemia acute lymphoblastic leukemia chronic lymphocytic leukemia acute myeloid leukemia and prolymphocytic leukemia
leukemids also known as nonspecific cutaneous conditions associated with leukemia are nonspecific skin lesions that occur with leukemia which are not related to leukemic cell infiltration this condition may be contrasted with leukemia cutis which is the infiltration of neoplastic leukocytes or their precursors into the skin resulting in clinically identifiable cutaneous lesions the term dates back to at least 1915
the term leukemoid reaction describes an increasedwhite blood cell count or leukocytosis which is a physiological response to stress or infection as opposed to a primary blood malignancy such as leukemia it often describes the presence of immature cells such as myeloblasts or red blood cells with nuclei in the peripheral blood it may be lymphoid or myeloid
leukocoria also leukokoria or white pupillary reflex is an abnormal white reflection from the retina of the eye leukocoria resembles eyeshine but leukocoria can occur in humans and other animals that lack eyeshine because their retina lacks a tapetum lucidum leukocoria is a medical sign for a number of conditions including coats disease congenital cataract corneal scarring melanoma of the ciliary body norrie disease ocular toxocariasis persistence of the tunica vasculosa lentis pfv phpv retinoblastoma and retrolental fibroplasia because of the potentially life threatening nature of retinoblastoma a cancer that condition is usually considered in the evaluation of leukocoria in some rare cases 1 the leukocoria is caused by coats disease leaking retinal vessels
leukocyte adhesion deficiency lad is a rare autosomal recessive disorder characterized by immunodeficiency resulting in recurrent infections lad is currently divided into three subtypes lad 1 lad 2 and the recently described lad 3 also known as lad 1 variant in lad 3 the immune defects are supplemented by a glanzmann thrombasthenia like bleeding tendency
leukocyte adhesion deficiency 1 lad 1 is a rare and often fatal genetic disorder in humans
leukocyte adhesion molecule deficiency is a rare autosomal recessive disorder characterized by recurrent bacterial and fungal infections and impaired neutrophil migration
leukocytosis is white cells the leukocyte count above the normal range in the blood it is frequently a sign of an inflammatory response most commonly the result of infection but may also occur following certain parasitic infections or bone tumors it may also occur after strenuous exercise convulsions such as epilepsy emotional stress pregnancy and labour anesthesia and epinephrine administration there are five principal types of leukocytosis 1 neutrophilia the most common form 2 lymphocytosis 3 monocytosis 4 eosinophilia 5 basophilia this increase in leukocyte primarily neutrophils is usually accompanied by a left shift in the ratio of immature to mature neutrophils the proportion of immature leukocytes increases due to proliferation and release of granulocyte and monocyte precursors in the bone marrow which is stimulated by several products of inflammation including c 3 a and g csf although it may indicate illness leukocytosis is considered a laboratory finding instead of a separate disease this classification is similar to that of fever which is also a test result instead of a disease right shift in the ratio of immature to mature neutrophils is considered with reduced count or lack of young neutrophils metamyelocytes and band neutrophils in blood smear associated with the presence of giant neutrophils this fact shows suppression of bone marrow activity as a hematological sign specific for pernicious anemia and radiation sickness a leukocyte count above 25 to 30 x 109 l is termed a leukemoid reaction which is the reaction of a healthy bone marrow to extreme stress trauma or infection it is different from leukemia and from leukoerythroblastosis in which either immature white blood cells acute leukemia or mature yet non functional white blood cells chronic leukemia are present in peripheral blood
leukoderma is a cutaneous condition an acquired condition with localized loss of pigmentation of the skin that may occur after any number of inflammatory skin conditions burns intralesional steroid injections postdermabrasion etc it is largely a cosmetic problem and is neither infectious nor contagious
leukodystrophy is one of a group of disorders characterized by degeneration of the white matter in the brain the word leukodystrophy comes from the greek roots leuko white dys lack of and troph growth the leukodystrophies are caused by imperfect growth or development of the myelin sheath the fatty covering that acts as an insulator around nerve fibers when damage occurs to white matter immune responses can lead to inflammation in the cns along with loss of myelin the degeneration of white matter can be seen in a mri and used to diagnose leukodystrophy leukodystrophy is characterized by specific symptoms including decreased motor function muscle rigidity and eventually degeneration of sight and hearing while the disease is fatal the age of onset is a key factor as infants are given a lifespan of 2 – 8 years sometimes longer while adults typically live more than a decade after onset there is a great lack of treatment although cord blood and hematopoietic stem cell transplantation bone marrow transplant seem to help in certain types while further research is being done the combined incidence of the leukodystrophies is estimated at 1 7 600 the majority of types involve the inheritance of a recessive dominant or x linked trait while others although involving a defective gene are the result of spontaneous mutation rather than genetic inheritance
leukoedema also spelled leucoedema is a blue grey or white appearance of mucosae particularly the buccal mucosa the inside of the cheeks it may also occur on the mucosa of the larynx or vagina it is a harmless and very common condition because it is so common it has been argued that it may in fact represent a variation of the normal appearance rather than a disease but empirical evidence suggests that leukoedema is an acquired condition caused by local irritation it is found more commonly in black skinned people and tobacco users the term is derived from the greek words leuko white and οἴδημα — oídēma swelling
leukoencephalopathy with vanishing white matter vwm disease is an autosomal recessive neurological disease the cause of the disease are mutations in any of the 5 genes encoding subunits of the translation initiation factor eif 2 b eif 2 b 1 eif 2 b 2 eif 2 b 3 eif 2 b 4 or eif 2 b 5 the disease belongs to a family of conditions called the leukodystrophies
leukonychia or leuconychia also known as white nails or milk spots is a medical term for white discoloration appearing on nails it is derived from the greek words leuko white and onux nail the most common cause is injury to the base of the nail the matrix where the nail is formed it is harmless and most commonly caused by minor injuries such as nail biting that occur while the nail is growing ieukonychia occurs most commonly in healthy individuals unrelated to any known nutritional or physiological deficiency when caused by injury the marks will disappear as the nail grows outwards however a dietary deficiency will cause recurrent leukonychia other possible reasons for this problem with nail color can be linked to arsenic poisoning pneumonia heart disease renal failure ill health hypoalbuminemia vitamin deficiency ulcerative colitis hypoproteinemia hepatic cirrhosis psychogenic stresses onychophagia occupational trauma lack of zinc lack of protein psoriasis as well as eczema lack of iron
leukopenia also known as leukocytopenia or leucopenia from greek λευκός white and πενία deficiency is a decrease in the number of white blood cells leukocytes found in the blood which places individuals at increased risk of infection neutropenia a subtype of leukopenia refers to a decrease in the number of circulating neutrophil granulocytes the most abundant white blood cells the terms leukopenia and neutropenia may occasionally be used interchangeably as the neutrophil count is the most important indicator of infection risk this should not be confused with agranulocytosis
leukoplakia also termed leucoplakia leukokeratosis leukoplasia idiopathic leukoplakia idiopathic keratosis or idiopathic white patch normally refers to a condition where areas of keratosis appear as firmly attached white patches on the mucous membranes of the oral cavity although the term is sometimes used for white patches of other gastrointestinal tract mucosal sites or mucosal surfaces of the urinary tract and genitals leukoplakia in the mouth oral leukoplakia is defined as a predominantly white lesion of the oral mucosa that cannot be characterized as any other definable lesion however this definition is inconsistently applied and some refer to any oral white patch as leukoplakia leukoplakia is a descriptive clinical term that is only correctly used once all other possible causes have been ruled out a diagnosis of exclusion as such leukoplakia is not a specific disease entity and the clinical and histologic appearance are variable i e the term has no specific histologic implications leukoplakia may be confused with other common causes of white patches in the mouth such as oral candidiasis or lichen planus the lesions of leukoplakia cannot be rubbed off as would be the case in pseudomembraneous candidiasis oral thrush oral leukoplakia more commonly occurs in those who smoke but often the cause is unknown hence the name idiopathic leukoplakia chewing tobacco is also associated with this type of lesion leukoplakia is a premalignant lesion i e a morphologically altered tissue in which cancer is more likely to occur than in its apparently normal counterpart the chance of transformation into oral squamous cell carcinoma oscc a type of oral cancer varies from almost 0 to about 20 and this may occur over 1 – 30 years the vast majority of oral leukoplakias will not turn malignant however some subtypes hold greater risk than others no interventions have been proven to reduce the risk of cancer developing in an area of leukoplakia but people are generally advised to stop smoking and limit alcohol consumption to reduce their risk sometimes the white patch will shrink and eventually disappear after stopping smoking but this may take up to a year in many cases areas of leukoplakia will slowly expand become more white and thicken if smoking is not stopped management usually involves regular review of the lesion to detect any possible malignant change early and thereby significantly improve the prognosis which normally is relatively poor for oscc
leukoplakia with tylosis and esophageal carcinoma is a rare condition characterized by leukoplakia associated with esophageal carcinoma
leukorrhea or leucorrhoea british english is a thick whitish or yellowish vaginal discharge there are many causes of leukorrhea the usual one being estrogen imbalance the amount of discharge may increase due to vaginal infection or stds and also it may disappear and reappear from time to time this discharge can keep occurring for years in which case it becomes more yellow and foul smelling it is usually a non pathological symptom secondary to inflammatory conditions of vagina or cervix leukorrhea can be confirmed by finding 10 wbc under a microscope when examining vaginal fluid vaginal discharge is not abnormal and causes of change in discharge include infection malignancy and hormonal changes it sometimes occurs before a girl has her first period and is considered a sign of puberty
leukotriene c 4 synthase deficiency is an inborn error of metabolism deficiency of leukotriene c 4 synthase can lead to a reduction in leukotriene c 4
leukotriene receptor antagonist associated churg – strauss syndrome may occur in asthma patients being treated with leukotriene receptor antagonists occurring 2 days to 10 months after the antagonist has been started with features of the syndrome including peripheral eosinphilia pulmonary infiltrates and less commonly neuropathy sinusitis and cardiomyopathy
lev s disease or lenegre lev syndrome is an acquired complete heart block due to idiopathic fibrosis and calcification of the electrical conduction system of the heart lev s disease is most commonly seen in the elderly and is often described as senile degeneration of the conduction system one form has been associated with scn 5 a
levamisole induced necrosis syndrome lines is a complication of adulterated cocaine recognized in 2011 caused by the use of levamisole as a cutting agent for cocaine
levator ani syndrome is a condition characterized by brief intermittent burning pain or tenesmus of the rectal or perineal area
in mathematical physics level spacing is the difference between consecutive elements in some set of real numbers in particular it is the difference between consecutive energy levels or eigenvalues of a matrix or linear operator
in graph theory and theoretical computer science the level ancestor problem is the problem of preprocessing a given rooted tree t into a data structure that can determine the ancestor of a given node at a given distance from the root of the tree more precisely let t be a rooted tree with n nodes and let v be an arbitrary node of t the level ancestor query la v d requests the ancestor of node v at depth d where the depth of a node v in a tree is the number of edges on the shortest path from the root of the tree to node v it is possible to solve this problem in constant time per query after a preprocessing algorithm that takes o n and that builds a data structure that uses o n storage space
in negotiation leverage is the ability to influence the other side to move closer to one s negotiating position types of leverage include positive leverage negative leverage and normative leverage
levo transposition of the great arteries l transposition of the great arteries levo tga or l tga also commonly referred to as congenitally corrected transposition of the great arteries cc tga is an acyanotic congenital heart defect chd in which the primary arteries the aorta and the pulmonary artery are transposed with the aorta anterior and to the left of the pulmonary artery the morphological left and right ventricles with their corresponding atrioventricular valves are also transposed use of the term corrected has been disputed by many due to the frequent occurrence of other abnormalities and or acquired disorders in l tga patients in segmental analysis this condition is described as atrioventricular discordance ventricular inversion with ventriculoarterial discordance l tga is often referred to simply as transposition of the great arteries tga however tga is a more general term which may also refer to dextro transposition of the great arteries d tga another term commonly used to refer to both l tga and d tga is transposition of the great vessels tgv although this term can have an even broader meaning than tga
levocardia is a medical condition where the heart is on the correct side of the body the left as oppposed to dextrocardia in which the heart is in the right side of the thoracic cavity this can be associated with situs solitus where the remainder of the organs are on correct side as well or situs inversus which implies the viscera stomach liver intestines etc and possibly the lungs are on the wrong side the latter condition may or may not be associated with clinically relevant abnormalities
levodopa induced dyskinesia is a form of dyskinesia associated with levodopa used to treat parkinson s disease it often involves hyperkinetic movements including chorea dystonia and athetosis in the context of parkinson s disease pd dyskinesia is often the result of long term dopamine therapy these motor fluctuations occur in up to 80 of pd patients after 5 – 10 years of l dopa treatment abstract with the percentage of affected patients increasing over time based on the relationship with levodopa dosing dyskinesia most commonly occurs at the time of peak l dopa plasma concentrations and is thus referred to as peak dose dyskinesia pdd as patients advance they may evidence diphasic dyskinesia dd which occur when the drug concentration rises or falls if dyskinesia becomes too severe or impairs the patient s quality of life a reduction in l dopa might be necessary however this may be accompanied by a worsening of motor performance therefore once established lid is difficult to treat amongst pharmacological treatment n methyl d aspartate nmda antagonist a glutamate receptor amantadine has been proven to be clinically effective in a small number of placebo controlled randomized controlled trials while many others have only shown promise in animal models attempts to moderate dyskinesia by the use of other treatments such as bromocriptine parlodel a dopamine agonist appears to be ineffective in order to avoid dyskinesia patients with the young onset form of the disease or young onset parkinson s disease yopd are often hesitant to commence l dopa therapy until absolutely necessary for fear of suffering severe dyskinesia later on alternatives include the use of da agonists i e ropinirole or pramipexole in lieu of early l dopa use which delays the use of l dopa additionally a review shows that highly soluble l dopa prodrugs may be effective in avoiding the in vivo blood concentration swings that potentially lead to motor fluctuations and dyskinesia
lewis lung carcinoma is a tumor discovered by dr margaret r lewis of the wistar institute in 1951 this tumor originated spontaneously as a carcinoma of the lung of a c 57 bl mouse the tumor does not appear to be grossly hemorrhagic and the majority of the tumor tissue is a semifirm homogeneous mass it is also called 3 ll and llc and is used as a transplantable malignancy it has been used in many studies in 1975 munson discovered that cannabinoids suppress lewis lung carcinoma cell growth the mechanism of this action was shown to be inhibition of dna synthesis cannabinoids increase the life span of mice carrying lewis lung tumors and decrease primary tumor size there are multiple modes of action
lex parliamentaria or a treatise of the law and custom of the parliaments of england was a pocket manual for members of the parliament of england it was originally attributed to george petyt however an attribution to irishman george philips seems now to be widely accepted including by the historians sir james ware and walter harris thomas jefferson praised the book in a letter to his son in law opining for parliamentary knowledge the lex parliamentaria is the best book its american counterparts are jefferson s own 1801 manual of parliamentary practice and lex parliamentaria americana by luther stearns cushing the term lex parliamentaria is also sometimes used to describe parliamentary law in general
lexical entrainment is the phenomenon in conversational linguistics of the process of the subject adopting the reference terms of their interlocutor in practice it acts as a mechanism of the cooperative principle in which both parties to the conversation employ lexical entrainment as a progressive system to develop conceptual pacts a working temporary conversational terminology to ensure maximum clarity of reference in the communication between the parties this process is necessary to overcome the ambiguity inherent in the multitude of synonyms that exist in language lexical entrainment arises by two cooperative mechanisms embedded corrections a reference to the object implied by the context of the sentence but with no explicit reference to the change in terminology exposed corrections an explicit reference to the change in terminology possibly including a request to assign the referent a common term e g by girl do you mean jane
lexical semantics also known as lexicosemantics is a subfield of linguistic semantics the units of analysis in lexical semantics are lexical units which include not only words but also sub words or sub units such as affixes and even compound words and phrases lexical units make up the catalogue of words in a language the lexicon lexical semantics looks at how the meaning of the lexical units correlates with the structure of the language or syntax this is referred to as syntax semantic interface the study of lexical semantics looks at the classification and decomposition of lexical items the differences and similarities in lexical semantic structure cross linguistically the relationship of lexical meaning to sentence meaning and syntax lexical units also referred to as syntactic atoms can stand alone such as in the case of root words or parts of compound words or they necessarily attach to other units such as prefixes and suffixes do the former are called free morphemes and the latter bound morphemes they fall into a narrow range of meanings semantic fields and can combine with each other to generate new meanings
in computer science the lexicographically minimal string rotation or lexicographically least circular substring is the problem of finding the rotation of a string possessing the lowest lexicographical order of all such rotations for example the lexicographically minimal rotation of bbaaccaadd would be aaccaaddbb it is possible for a string to have multiple lexicographically minimal rotations but for most applications this does not matter as the rotations must be equivalent finding the lexicographically minimal rotation is useful as a way of normalizing strings if the strings represent potentially isomorphic structures such as graphs normalizing in this way allows for simple equality checking a common implementation trick when dealing with circular strings is to concatenate the string to itself instead of having to perform modular arithmetic on the string indices
leydig cell hypoplasia or aplasia lch also known as leydig cell agenesis is a rare autosomal recessive genetic and endocrine syndrome affecting an estimated 1 in 1 000 000 biological males it is characterized by an inability of the body to respond to luteinizing hormone lh a gonadotropin which is normally responsible for signaling leydig cells of the testicles to produce testosterone and other androgen sex hormones the condition manifests itself as pseudohermaphroditism partially or fully underdeveloped genitalia hypergonadotropic hypogonadism decreased or lack of production of sex steroids by the gonads despite high circulating levels of gonadotropins reduced or absent puberty lack of development of secondary sexual characteristics resulting in sexual infantilism if left untreated and infertility leydig cell hypoplasia does not occur in biological females as they do not have either leydig cells or testicles however the cause of the condition in males luteinizing hormone insensitivity does affect females and because lh plays a role in the female reproductive system it can result in primary amenorrhea or oligomenorrhea absent or reduced menstruation infertility due to anovulation and ovarian cysts a related condition is follicle stimulating hormone fsh insensitivity which presents with similar symptoms to those of leydig cell hypoplasia but with the symptoms in the respective sexes reversed i e hypogonadism and sexual infantilism in females and merely problems with fertility in males despite their similar causes fsh insensitivity is considerably less common in comparison to lh insensitivity
leydig cell tumour also leydig cell tumor us spelling testicular interstitial cell tumour and testicular interstitial cell tumor us spelling is a member of the sex cord stromal tumour group of ovarian and testicular cancers it arises from leydig cells while the tumour can occur at any age it occurs most often in young adults a sertoli leydig cell tumour is a combination of a leydig cell tumour and a sertoli cell tumour from sertoli cells
lhermitte s phenomenon or the lhermitte phenomenon lɛrˈmiːt sometimes called the barber chair phenomenon is an electrical sensation that runs down the back and into the limbs the sensation can feel like it goes up or down the spine it is generally considered uncomfortable in many patients it is elicited by bending the head forward it can also be evoked when a practitioner pounds on the posterior cervical spine while the neck is flexed this is caused by involvement of the posterior columns it is sometimes called lhermitte s sign though this is technically incorrect as a sign is something that can be observed on examination whereas a symptom is the subjective experience lhermitte s phenomenon is subjective and therefore a symptom lhermitte s phenomenon is named for french neurologist jean lhermitte
lhermitte – duclos disease ldd english ˌlɛrˈmiːtˌduːˈkloʊ also called dysplastic gangliocytoma of the cerebellum is a rare slowly growing tumor of the cerebellum a gangliocytoma sometimes considered to be a hamartoma characterized by diffuse hypertrophy of the granular layer of the cerebellum it is often associated with cowden syndrome it was described by jacques jean lhermitte and p duclos in 1920
the library angel is a phenomenon described by arthur koestler in which information typically in libraries becomes accessible through chance or coincidence rather than through the use of a cataloguing system the library angel can be regarded as a form of synchronicity bernard beitman who conducted research in coincidence studies found that 18 of his respondents had acquired information in an unexpected way
lichen aureus also known as lichen purpuricus is a skin condition characterized by the sudden appearance of one or several golden or rust colored closely packed macules or lichenoid papules
lichen myxedematosus is a group of cutaneous disorders considered mucinoses conditions included in this group are generalized lichen myxedematosus localized lichen myxedematosus discrete papular lichen myxedematosus acral persistent papular mucinosis self healing papular mucinosis self healing juvenile cutaneous mucinosis papular mucinosis of infancy atypical lichen myxedematosus atypical tuberous myxedema
lichen nitidus is a chronic inflammatory disease of unknown cause characterized by 1 – 2 mm discrete and uniform shiny flat topped pale flesh colored or reddish brown papules that may appear as hypopigmented against dark skin occasionally minimal scaling is present or can be induced by rubbing the surface of the papules the disease usually affects children and young adults and is painless and usually nonpruritic although protracted itching may occur in some cases it is sometimes referred to by dermatologists as mini lichen planus
lichen planus lp is an uncommon disease of the skin with a prevalence reported between 0 1 – 0 3 in men and women respectively the cause is unknown but it is thought to be the result of an autoimmune process with an unknown initial trigger there is no cure but many different medications and procedures have been used in efforts to control the symptoms the term lichenoid reaction or lichenoid lesion refers to a lesion of similar or identical histopathologic and clinical appearance to lichen planus i e an area which looks the same as lichen planus both to the naked eye and under a microscope sometimes dental materials or certain medications can cause a lichenoid reaction they can also occur in association with graft versus host disease
wise rein disease lichen ruber moniliformis is a rare skin disease named for fred wise and charles r rein it is one of several diseases also known as kaposi s disease based on its characterization in 1886 by moritz kaposi it is thought to be a rare variety of lichen planus it is also known as morbus moniliformis lichenoides
lichen sclerosus ls and also known as lichen sclerosus et atrophicus lseta also termed incorrectly lichen sclerosis et atrophicus is a disease of unknown cause that results in white patches on the skin which may cause scarring on and around genital or sometimes other skin there is a bimodal age distribution in the incidence of ls it occurs in females with an average age of diagnosis of 7 6 years in girls and 60 years old in women the average age of diagnosis in boys is 9 – 11 years old several risk factors have been proposed including autoimmune diseases infections and genetic predisposition there is evidence that ls can be associated with thyroid disease
lichen scrofulosorum also known as tuberculosis cutis lichenoides is a rare tuberculid that presents as a lichenoid eruption of minute papules in children and adolescents with tuberculosis the lesions are usually asymptomatic closely grouped skin colored to reddish brown papules often perifollicular and are mainly found on the abdomen chest back and proximal parts of the limbs the eruption is usually associated with a strongly positive tuberculin reaction of the three tuberculids the incidence of lichen scrofulosorum was found to be the lowest 2 in a large study conducted in hong kong this highlights its rarity and significance as an important marker of undetected tuberculosis
lichen simplex chronicus also known as neurodermatitis is a skin disorder characterized by chronic itching and scratching the constant scratching causes thick leathery brownish skin this condition is more common between ages 30 and 50 and is seen more in women than in men
lichen spinulosus also known as keratosis spinulosa is a rare skin disorder characterized by follicular keratotic papules that are grouped into large patches it is a variant of keratosis pilaris
lichen striatus also known as blaschko linear acquired inflammatory skin eruption and linear lichenoid dermatosis is a rare skin condition that is seen primarily in children most frequently appearing ages 5 – 15 it consists of a self limiting eruption of small scaly papules
lichen verrucosus et reticularis is a cutaneous condition that may be related to keratosis lichenoides chronica
a lichenoid eruption is a skin disease characterized by damage and infiltration between the epidermis and dermis examples include lichen planus lichen sclerosus and lichen nitidus it can also be associated with abrasion or drug use it has been observed in conjunction with the use of proton pump inhibitors the term lichenoid derives from a resemblance to a lichen
lichenoid trikeratosis is a cutaneous condition that may be related to keratosis lichenoides chronica
a lick granuloma also known as acral lick dermatitis is a skin disorder in dogs it results typically from the dog s urge to lick the lower portion of one of his or her legs the lesion can initially be red swollen irritated and bleeding similar to a hot spot wet eczema the dog s incessant licking of the lesion eventually results in a thickened firm oval plaque a major cause of lick granuloma appears to be psychological related to stress anxiety separation anxiety boredom or compulsiveness lick granulomas are especially seen in active dogs left alone for long periods of time one theory is that excessive licking causes endorphin release which reduces pain and makes the dog feel euphoric temporarily that effect then causes an addiction to licking treatment of the primary cause if known is essential in psychogenic cases psychological factors should be identified and addressed such as being left alone all day being confined and changes in the household
licorice is an extract from the glycyrrhiza glabra plant which contains glycyrrhizic acid or gza gza is made of one molecule of glycyrrhetic acid and two molecules of glucuronic acid the extracts from the root of the plant can also be referred to as licorice sweet root and glycyrrhiza extract g glabra grows in subtropical climates in europe the middle east and western asia when administered orally the product of glycyrrhetic acid is found in human urine whereas gza is not this shows that glycyrrhetic acid is absorbed and metabolized in the intestines in humans gza is hydrolyzed to glycyrrhetic acid in the intestines by bacteria for thousands of years g glabra has been used for medicinal purposes including indigestion and stomach inflammation some other medicinal purposes are cough suppression ulcer treatment and use as a laxative also salts of gza can be used in many products as sweeteners and aromatizers the major use of licorice goes towards the tobacco industry at roughly 90 of usage the rest is split evenly between food and pharmaceutics at 5 of usage each federal register 1983 licorice extract is often found in sweets and many candies some drugs and beverages like root beer they can also be used in chewing gum tobacco products like snuff and toothpaste an increase in intake of licorice can cause many toxic effects hypermineralocorticosteroid syndrome can occur when the body retains sodium loses potassium altering biochemical and hormonal activities some of these activities include lower aldosterone level decline of the renin angiotensin system and increased levels of the atrial natriuretic hormone in order to compensate the variations in homoeostasis some other symptoms of toxicity include electrolyte imbalance oedema increased blood pressure weight gain heart problems and weakness individuals will experience certain symptoms based on the severity of toxicity some other complaints include fatigue shortness of breath renal failure and paralysis many adverse effects of licorice poisoning can be seen and most are attributed to the mineralocorticoid effects of gza depending on the dose and intake of licorice serious problems and even hospitalization can arise people with previously existing heart or kidney problems may be more susceptible to gza and licorice poisoning it is important to monitor the amount of licorice consumed in order to prevent toxicity it is difficult to determine a safe level due to many varying factors from person to person in the most sensitive individuals daily intake of about 100 mg gza can cause problems this is equivalent to 50 g licorice sweets however in most people they can consume up to 400 mg before experiencing symptoms which would be about 200 g licorice sweets a rule of thumb says a normal healthy person can consume 10 mg gza a day
liddle s syndrome also called liddle syndrome and pseudohyperaldosteronism is a genetic disorder inherited in an autosomal dominant manner that is characterized by early and frequently severe high blood pressure associated with low plasma renin activity metabolic alkalosis low blood potassium and normal to low levels of aldosterone liddle syndrome involves abnormal kidney function with excess reabsorption of sodium and loss of potassium from the renal tubule and is treated with a combination of low sodium diet and potassium sparing diuretic drugs e g amiloride it is extremely rare with fewer than 30 pedigrees or isolated cases having been reported worldwide as of 2008
in the theory of lie groups lie algebras and their representation theory a lie algebra extension e is an enlargement of a given lie algebra g by another lie algebra h extensions arise in several ways there is the trivial extension obtained by taking a direct sum of two lie algebras other types are the split extension and the central extension extensions may arise naturally for instance when forming a lie algebra from projective group representations such a lie algebra will contain central charges starting with a polynomial loop algebra over finite dimensional simple lie algebra and performing two extensions a central extension and an extension by a derivation one obtains a lie algebra which is isomorphic with an untwisted affine kac – moody algebra using the centrally extended loop algebra algebra one may construct a current algebra in two spacetime dimensions the virasoro algebra is the universal central extension of the witt algebra central extensions are needed in physics because the symmetry group of a quantized system usually is a central extension of the classical symmetry group and in the same way the corresponding symmetry lie algebra of the quantum system is in general a central extension of the classical symmetry algebra kac – moody algebras have been conjectured to be a symmetry groups of a unified superstring theory the centrally extended lie algebras play a dominant role in quantum field theory particularly in conformal field theory string theory and in m theory a large portion towards the end is devoted to background material for applications of lie algebra extensions both in mathematics and in physics in areas where they are actually useful a parenthetical link is provided where it might be beneficial
the condition was first described by dr f liebenberg in 1973 while he followed multiple generations of a south african family but it has since been noticed in other family lineages across the world
the liebeskind – srogl coupling reaction is an organic reaction forming a new carbon – carbon bond from a thioester and a boronic acid using a metal catalyst this reaction was invented and named after jiri srogl from the academy of sciences czech republic and lanny s liebeskind from emory university atlanta georgia usa the metal catalyst depicted below uses tfp tris 2 furyl phosphine as an additional ligand and cutc copper i thiophene 2 carboxylate as a co metal catalyst the overall reaction scheme is shown below the liebeskind srogl coupling reaction
liesegang rings ˈliːzəɡɑːŋ are a phenomenon seen in many if not most chemical systems undergoing a precipitation reaction under certain conditions of concentration and in the absence of convection
life is pain is a german rock band from forchheim upper franconia
a life debt is a literary phenomenon in which someone whose life is saved or spared by another becomes indebted or in some way connected to their savior a life debt can only be paid off by saving the original saviour s life in return
life is a problem is an album by marah released in 2010
a life review is a phenomenon widely reported as occurring during near death experiences in which a person rapidly sees much or the totality of their life history in chronological sequence and in extreme detail it is often referred to by people having experienced this phenomenon as having their life flash before their eyes the life review is discussed in some detail by near death experience scholars such as raymond moody kenneth ring and barbara rommer a reformatory purpose seems commonly implicit in accounts though not necessarily for earthly purpose since return from a near death experience may reportedly entail individual choice while experiencers who number up to eight million in the united states sometimes report that reviews took place in the company of otherworldly beings who shared the observation they also say they felt unjudged during the process leaving themselves their own strongest critics although rare there are also a few accounts of life reviews or similar experiences without a near death experience such as during the simpler out of body experience or when under circumstances of intense threat or duress many scientists discount near death experiences themselves and criticize their credibility furthermore there is evidence suggesting cultural differences in the near death experience which is why some believe ndes are hallucinary
lifestyle diseases also sometimes called diseases of longevity or diseases of civilization interchangeably are defined as diseases linked with the way people live their life this is commonly caused by alcohol drug and smoking abuse as well as lack of physical activity and unhealthy eating diseases that impact on our lifestyle are heart disease stroke obesity and type ii diabetes the diseases that appear to the increase in frequency as countries become more industrialized and people live longer they can include alzheimer s disease arthritis atherosclerosis asthma cancer chronic liver disease or cirrhosis chronic obstructive pulmonary disease type 2 diabetes heart disease metabolic syndrome chronic renal failure osteoporosis stroke depression and obesity in the u k the death rate is four times higher from respiratory disease caused by an unhealthy lifestyle some commenters maintain a distinction between diseases of longevity and diseases of civilization certain diseases such as diabetes dental caries or asthma appear at greater rates in young populations living in the western way their increased incidence is not related to age so the terms cannot accurately be used interchangeably for all diseases
in aerodynamics the lift to drag ratio or l d ratio is the amount of lift generated by a wing or vehicle divided by the aerodynamic drag it creates by moving through the air a higher or more favorable l d ratio is typically one of the major goals in aircraft design since a particular aircraft s required lift is set by its weight delivering that lift with lower drag leads directly to better fuel economy in aircraft climb performance and glide ratio the term is calculated for any particular airspeed by measuring the lift generated then dividing by the drag at that speed these vary with speed so the results are typically plotted on a 2 d graph in almost all cases the graph forms a u shape due to the two main components of drag lift to drag ratios can be determined by flight test by calculation or by testing in a wind tunnel
lift is a meteorological phenomenon used as an energy source by soaring aircraft and soaring birds the most common human application of lift is in sport and recreation the three air sports that use soaring flight are gliding hang gliding and paragliding energy can be gained by using rising air from four sources thermals where air rises due to heat ridge lift where air is forced upwards by a slope wave lift where a mountain produces a standing wave convergence where two air masses meet in dynamic soaring it is also possible to gain energy though this uses differences in wind speeds rather than rising air
the lifted index li is the temperature difference between an air parcel lifted adiabatically tp p and the environment te p at a given pressure height in the troposphere lowest layer where most weather occurs of the atmosphere usually 500 hpa mb when the value is positive the atmosphere at the respective height is stable and when the value is negative the atmosphere is unstable
ligamentous laxity or ligament laxity is a term given to describe loose ligaments ligamentous laxity is a cause of chronic body pain characterized by loose ligaments when this condition affects joints in the entire body it is called generalized joint hypermobility which occurs in about five percent of the population and may be genetic loose ligaments can appear in a variety of ways and levels of severity it also does not always affect the entire body one could have loose ligaments of the feet but not of the arms someone with ligamentous laxity by definition has loose ligaments unlike other more pervasive diseases the diagnosis does not require the presence of loose tendons muscles or blood vessels hyperlax skin or other connective tissue problems in heritable connective tissue disorders associated with joint hypermobility such as marfan syndrome and ehlers danlos syndrome types i iii vii and xi the joint laxity usually is apparent before adulthood however age of onset and extent of joint laxity are variable in marfan syndrome and joint laxity may be confined to the hands alone as in ehlers danlos syndrome type iv in most people ligaments which are the tissues that connect bones to each other are naturally tight in such a way that the joints are restricted to normal ranges of motion this creates normal joint stability if muscular control does not compensate for ligamentous laxity joint instability may result the trait is almost certainly hereditary and is usually something the affected person would just be aware of rather than a serious medical condition however if there is widespread laxity of other connective tissue then this may be a sign of ehlers danlos syndrome ligamentous laxity may also result from injury such as a injury or a car accident it can result from whiplash and be overlooked for years by doctors who are not looking for it despite the chronic pain that accompanies the resultant spinal instability ligamentous laxity will show up on an upright mri the only kind of mri that will show soft tissue damage it can be seen in standing stress radiographs in flexion extension and neutral views as well and also digital motion x ray or dmx an advantage to having lax ligaments and joints is the ability to withstand pain from hyperextension however this is also a disadvantage as a lack of perceived pain can prevent a person from removing the ligament from insult leading to ligament damage people with hypermobile joints or double jointed people almost by definition have lax ligaments
the light independent reactions of photosynthesis are chemical reactions that convert carbon dioxide and other compounds into glucose these reactions occur in the stroma the fluid filled area of a chloroplast outside of the thylakoid membranes these reactions take the products atp and nadph of light dependent reactions and perform further chemical processes on them there are three phases to the light independent reactions collectively called the calvin cycle carbon fixation reduction reactions and ribulose 1 5 bisphosphate rubp regeneration despite its name this process occurs only when light is available plants do not carry out the calvin cycle during nighttime they instead release sucrose into the phloem from their starch reserves this process happens when light is available independent of the kind of photosynthesis c 3 carbon fixation c 4 carbon fixation and crassulacean acid metabolism cam plants store malic acid in their vacuoles every night and release it by day in order to make this process work
light time correction is a displacement in the apparent position of a celestial object from its true position or geometric position caused by the object s motion during the time it takes its light to reach an observer light time correction occurs in principle during the observation of any moving object because the speed of light is finite the magnitude and direction of the displacement in position depends upon the distance of the object from the observer and the motion of the object and is measured at the instant at which the object s light reaches the observer it is independent of the motion of the observer it should be contrasted with the aberration of light which depends upon the instantaneous velocity of the observer at the time of observation and is independent of the motion or distance of the object light time correction can be applied to any object whose distance and motion are known in particular it is usually necessary to apply it to the motion of a planet or other solar system object for this reason the combined displacement of the apparent position due to the effects of light time correction and aberration is known as planetary aberration by convention light time correction is not applied to the positions of stars because their motion and distance may not be known accurately
light chain deposition disease lcdd is a rare blood cell disease which is characterized by deposition of fragments of infection fighting immunoglobulins called light chains lcs in the body lcs are normally cleared by the kidneys but in lcdd these light chain deposits damage organs and cause disease the kidneys are almost always affected and this often leads to kidney failure about half of people with light chain deposition disease also have multiple myeloma unlike in al amyloidosis in which light chains are laid down in characteristic amyloid deposits in lcdd light chains are deposited in non amyloid granules
a light echo is a phenomenon observed in astronomy analogous to an echo of sound a light echo is produced when a sudden flash or burst of light such as that observed in novae is reflected off a source and arrives at the viewer after a considerably longer duration than it otherwise would have taken with a direct path because of their geometries light echoes can produce the illusion of superluminal speeds
the light field is a vector function that describes the amount of light flowing in every direction through every point in space the direction of each ray is given by the 5 d plenoptic function and the magnitude of each ray is given by the radiance michael faraday was the first to propose in an 1846 lecture entitled thoughts on ray vibrations that light should be interpreted as a field much like the magnetic fields on which he had been working for several years the phrase light field was coined by andrey gershun in a classic paper on the radiometric properties of light in three dimensional space 1936
in ecology a light gap is a break in the forest canopy or similar barrier that allows young plants to grow where they would be otherwise inhibited by the lack of light reaching the seedbed light gaps form predominantly when a tree falls and thus produces an opening in the forest canopy
a light pillar is an atmospheric optical phenomenon in the form of a vertical band of light which appears to extend above and or below a light source the effect is created by the reflection of light from numerous tiny ice crystals suspended in the atmosphere or clouds the light can come from the sun usually when it is near or even below the horizon in which case the phenomenon is called a sun pillar or solar pillar it can also come from the moon or from terrestrial sources such as streetlights
lightning burns are a cutaneous condition a type of electrical burn following a lightning strike on a human they are characterized by a unique pattern of skin lesions alternative names for them include keraunographic markings feathering ferning lichtenberg figures lightning flowers or lightning trees according to a bbc article the marks are formed when capillaries beneath the skin rupture due to the electrical discharge and they usually appear within hours of the strike though they tend to disappear within a few days they also generally occur on the upper body
lightning injuries are injuries caused by lightning strikes they result from three factors electrical damage intense heat the mechanical energy which these generate while sudden death is common because of the huge voltage of a lightning strike survivors often fare better than victims of other electrical injuries caused by a more prolonged application of lesser voltage the treatment of lightning injuries is keraunomedicine
lightwood – albright syndrome is a form of renal tubular acidosis it is also known as lightwood syndrome it is named for reginald cyril lightwood and fuller albright
in the philippines lihí is a condition in which a pregnant woman craves strongly for something usually food such as sour unripe mango with bagoong while it is a cultural concept universal to filipinos it is also understood that expectant mothers of any race may experience lihí it is still debatable as to whether lihí can be classified as either a biological or psychological condition
in statistics a likelihood function often simply the likelihood is a function of the parameters of a statistical model given data likelihood functions play a key role in statistical inference especially methods of estimating a parameter from a set of statistics in informal contexts likelihood is often used as a synonym for probability in statistics a distinction is made depending on the roles of outcomes vs parameters probability is used before data are available to describe possible future outcomes given a fixed value for the parameter or parameter vector likelihood is used after data are available to describe a function of a parameter or parameter vector for a given outcome
lilac witches ’ broom lwb is a disease of lilacs caused by the phytoplasma candidatus phytoplasma fraxini this phytoplasma was first identified as the causal agent of ash yellows and has since been attributed to both diseases symptoms of the lwb phytoplasma include witches brooms shortened internodes on new growth twig dieback overall loss of vitality and premature death detection is primarily performed based on physiological symptoms in the host plant although a new identification based on direct gene sequencing has been confirmed there is no known cure for this disease so management strategies involving culling and proper disposal of infected specimens is encouraged the disease is believed to be spread by means of an insect vector most likely of the order hemiptera certain cultivars of lilacs appear to be more susceptible notably those of the preston lilac series developed at the central experimental farm in ottawa canada recent research performed there suggests heat treatment of scion material as an effective means of sterilization
limb girdle muscular dystrophy lgmd or erb s muscular dystrophy is a genetically and clinically heterogeneous group of rare muscular dystrophies it is characterised by progressive muscle wasting which affects predominantly hip and shoulder muscles lgmd has an autosomal pattern of inheritance and currently has no known cure
limb body wall complex lbwc is a rare fetal malformation of unknown origins traditionally diagnosis has been based on the van allen et al criteria i e the presence of two out of three of the following anomalies 1 exencephaly or encephalocele with facial clefts 2 thoraco and or abdominoschisis and 3 limb defects lbwc occurs in approximately 0 32 in 100 000 births at this time there is no known cause of limb body wall complex however there have been tentative links made between a diagnosis of lbwc and cocaine use in addition current research has shown that there may be a genetic cause for a small limited number of lbwc cases limb body wall complex is a lethal birth defect there are only anecdotal stories of survivors
limb darkening is an optical effect seen in stars including the sun where the center part of the disk appears brighter than the edge or limb of the image its understanding offered early solar astronomers an opportunity to construct models with such gradients this encouraged the development of the theory of radiative transfer
limber tail syndrome or acute caudal myopathy is a disorder of the muscles in the tail usually affecting working dogs an injury occurring mostly in sporting or working dogs such as english pointers english setters foxhounds beagles and labrador retrievers limber tail syndrome is also known as swimmer s tail cold water tail broken tail dead tail or broken wag
limbic encephalitis is a form of encephalitis a disease characterised by inflammation of the brain limbic encephalitis is caused by autoimmunity an abnormal state where the body produces antibodies against itself some cases are associated with cancer and some are not although the disease is known as limbic encephalitis it is seldom limited to the limbic system and post mortem studies usually show involvement of other parts of the brain the disease was first described by brierley and others in 1960 as a series of three cases the link to cancer was first noted in 1968 and confirmed by later investigators the majority of cases of limbic encephalitis are associated with a tumour diagnosed or undiagnosed in cases caused by tumour cure is only achieved when the tumour is removed completely this is not always possible limbic encephalitis is classified according to the auto antibody that causes the disease the most common types are anti hu which is associated with small cell carcinoma of the lungs anti ma 2 associated with germ cell tumours of the testis anti nmdar associated with tumors of the ovaries commonly teratomas since 2002 following a report of case of a 21 year old woman subacutely developed memory loss subsequent to gastroenteritis similar cases of non paraneoplastic le its association with auto antibody and response to steroid has been described limbic encephalitis associated with voltage ‐ gated potassium channel antibodies vgkc ‐ abs may frequently be non ‐ paraneoplastic a recent study of 15 cases of limbic encephalitis found raised vgkc ‐ abs associated with non ‐ paraneoplastic disorders and remission following immunosuppressive treatment
a limbus vertebra also see vertebral epophysis is a bone trauma in the vertebral body bearing a radiographic similarity to a vertebral fracture the anterior superior corner of a single vertebra is the common site for this defect although it can also be seen at the inferior corner as well as the posterior or anterior margin anatomically it is assumed to be an intra vertebral body herniation of the disc material occurring during adolescent growt spurt when the ring apophysis has not yet fused it was first described by schmorl in 1927 and later in detail by leif sward and adad baranto viewed in a lateral radiograph it appears as a triangular shaped bone fragment not unlike an anterior lip fracture but with softer edges limbus vertebra is not always symptomatic but severe cases may lead to more serious pathological conditions and chronic pain in rare instances a posterior limbus vertebra has been described causing radiculopathy due to nerve root compression
limb – mammary syndrome is a cutaneous condition characterized by p 63 mutations
a limp is a type of asymmetric abnormality of the gait limping may be caused by pain weakness neuromuscular imbalance or a skeletal deformity the most common underlying cause of a painful limp is physical trauma however in the absence of trauma other serious causes such as septic arthritis or slipped capital femoral epiphysis may be present the diagnostic approach involves ruling out potentially serious causes via the use of x rays blood tests and sometimes joint aspiration initial treatment involves pain management a limp is the presenting problem in about 4 of children who visit hospital emergency departments
limp wristing is a phenomenon commonly encountered by semiautomatic pistol shooters where the shooter s grip is not firm enough and the wrist is not held firm straight enough to keep the frame of the firearm from traveling rearward while the bolt or slide of the pistol cycles this condition often results in a failure to complete the operating cycle properly termed a malfunction but commonly and incorrectly termed a jam rifles and shotguns if fired without the stock in the shoulder may also be prone to limp wristing of the important variables involved in this type of jam bullet and gas momentum slide and barrel mass recoil spring pre load and spring rate and shooting hand and arm mass are much more important than the compliance limpness of the wrist
linburg – comstock syndrome is an abnormal tendinous connection between the flexor pollicis longus and the flexor digitorum profundus of the index the middle finger or both it is an anatomical variation in human which may be viewed as a pathology if causes symptoms it was recognised as early as the 1800 s but was first described by linburg and comstock in 1979
in probability theory lindeberg s condition is a sufficient condition and under certain conditions also a necessary condition for the central limit theorem clt to hold for a sequence of independent random variables unlike the classical clt which requires that the random variables in question have finite mean and variance and be both independent and identically distributed lindeberg s clt only requires that they have finite mean and variance satisfy lindeberg s condition and be independent it is named after the finnish mathematician jarl waldemar lindeberg
line regulation is the ability to maintain a constant output voltage level on the output channel of a power supply despite changes to the input voltage level
a lineal descendant in legal usage is a blood relative in the direct line of descent the children grandchildren great grandchildren etc of a person in a legal procedure sense lineal descent refers to the acquisition of estate by inheritance from grandparent to parent and parent to child whereas collateral descent refers to the acquisition of estate or real property by inheritance from sibling to sibling and cousin to cousin adopted children for whom adoption statutes create the same rights of heirship as children of the body come within the meaning of the term lineal descendants as used in a statute providing for the non lapse of a devise where the devisee predeceases the testator but leaves lineal descendants among native american tribes in the united states tribal enrollment can be determined by lineal descent as opposed to a minimum blood quantum lineal descent means that anyone directly descended from original tribal enrollees could be eligible for tribal enrollment regardless of how much native blood they have
linear iga bullous dermatosis also known as linear iga dermatosis is frequently associated with medication exposure especially vancomycin with men and women being equally affected it was first described by tadeusz chorzelski in 1979 linear iga dermatosis is a rare immune mediated blistering skin disease that may be divided into two types adult linear iga disease is an acquired autoimmune blistering disease that may present with a clinical pattern of vesicles indistinguishable from dermatitis herpetiformis or with vesicles and bullae in a bullous pemphigoid like appearance this disease can often be difficult to treat even with usually effective medications such as rituximab childhood linear iga disease also known as chronic bullous disease of childhood is an acquired self limited bullous disease that may begin by the time the patient is age 2 to 3 and usually remits by age 13
linear and whorled nevoid hypermelanosis also known as linear nevoid hyperpigmentation progressive cribriform and zosteriform hyperpigmentation reticulate and zosteriform hyperpigmentation reticulate hyperpigmentation of iijima and naito and uyeno zebra like hyperpigmentation in whorls and streaks and zebra line hyperpigmentation is a disorder of pigmentation that develops within a few weeks of birth and progresses for one to two years before stabilizing there is linear and whorled hyperpigmentation following the lines of blaschko without preceding bullae or verrucous lesions it is important to exclude other pigmentary disorders following the blaschko lines before making a diagnosis of linear and whorled nevoid hypermelanosis the differential diagnoses include incontinentia pigmenti linear epidermal nevus hypomelanosis of ito and goltz syndrome recently a case of linear and whorled nevoid hypermelanosis was reported in a malaysian chinese girl
linear atrophoderma of moulin also known as moulin atrophoderma linearis is an acquired unilateral dermatitis localized along the blaschko lines it affects children or adolescents of both genders involving the trunk and the limbs it is presumably a rare cutaneous form of mosaicism this disease was first referred to as atrophoderma of moulin after dr moulin who first reported it in 1992 then was renamed as linear atrophoderma of moulin only a few dozen cases have been described for this reason lam is considered to be a very rare disorder
linear focal elastosis also known as elastotic striae presents with asymptomatic palpable or atrophic yellow lines of the middle and lower back thighs arms and breasts
in calculus and related areas of mathematics a linear function from the real numbers to the real numbers is a function whose graph in cartesian coordinates with uniform scales is a line in the plane their characteristic property that when the value of the input variable is changed the change in the output is a constant multiple of the change in the input variable linear functions are related to linear equations
linear gingival erythema lge is a periodontal disorder diagnosed based on distinct clinical characteristics it was originally thought that lge was directly associated with hiv and it was thus called hiv associated gingivitis hiv g later research confirmed that lge also occurs in hiv negative immunocompromised patients and it was thus renamed
in statistics and in machine learning a linear predictor function is a linear function linear combination of a set of coefficients and explanatory variables independent variables whose value is used to predict the outcome of a dependent variable this sort of function usually comes in linear regression where the coefficients are called regression coefficients however they also occur in various types of linear classifiers e g logistic regression perceptrons support vector machines and linear discriminant analysis as well as in various other models such as principal component analysis and factor analysis in many of these models the coefficients are referred to as weights
the linear range is that range of input or output values for which an electronic amplifier produces an output signal that is a direct linear function of the input signal that is the output can be represented by the equation output input × gain when operating in the linear range no clipping occurs if an amplifier were perfectly linear no distortion harmonic distortion or intermodulation distortion would occur although random noise may still be introduced vacuum tube amplifiers tend to exhibit soft clipping as they approach the maximum possible output value the gain tends to drop rounding the tops of the signal waveform transistor amplifiers by comparison tend to produce hard clipping the gain remains approximately the same until the maximum possible output voltage is reached at that point hard clipping occurs and the waveform never exceeds that value the sharp inflection points thus produced in the output waveform tend to have many more high order harmonics this is alleged to be the basis of the transistor sound that some audiophiles find offensive although this would not have occurred if they would not have been driving their amplifiers beyond the linear range in the first place
in computational complexity theory the linear search problem is an optimal search problem introduced by richard e bellman independently considered by anatole beck
linear verrucous epidermal nevus also known as a linear epidermal nevus and verrucous epidermal nevus is a skin lesion characterized by a verrucous skin colored dirty gray or brown papule generally multiple papules present simultaneously and coalesce to form a serpiginous plaque when this nevus covers a diffuse or extensive portion of the body s surface area it may be referred to as a systematized epidermal nevus when it involved only one half of the body it is called a nevus unius lateris
linguatulosis is a condition associated with the organism linguatula serrata the usual final host for linguatula serrata is a carnivore like a dog or jackal and the species is sometimes known as the dog tongueworm for this reason more generally linguatulosis can be considered a form of pentastomiasis which refers to all diseases caused by pentastomids including porocephaliasis this disease is often accidentally identified during autopsy because of its asymptomatic effect on the body human infestation by linguatula was historically more commonplace than is sometimes realised human liver autopsies in berlin from the early part of the 20 th century revealed an infection rate of nearly 12
linguistic philosophy describes the view that philosophical problems are problems which may be solved or dissolved either by reforming language or by understanding more about the language we presently use the former position is that of ideal language philosophy the latter the position of ordinary language philosophy
linguistic purism in icelandic is a sociolinguistic phenomenon with the aim of substituting loanwords with the creation of new words from old icelandic and old norse roots and preventing new loanwords from entering the language in iceland linguistic purism is archaising trying to resuscitate the language of a golden age of icelandic literature the effort began in the early 19 th century at the dawn of the icelandic national movement aiming at replacing older loanwords especially from danish and it continues today targeting english words it is widely upheld in iceland and it is the dominant language ideology it is fully supported by the icelandic government through the árni magnússon institute for icelandic studies the icelandic language council the icelandic language fund and an icelandic language day
a linguistic universal is a pattern that occurs systematically across natural languages potentially true for all of them for example all languages have nouns and verbs or if a language is spoken it has consonants and vowels research in this area of linguistics is closely tied to the study of linguistic typology and intends to reveal generalizations across languages likely tied to cognition perception or other abilities of the mind the field was largely pioneered by the linguist joseph greenberg who derived a set of forty five basic universals mostly dealing with syntax from a study of some thirty languages
linitis plastica also known as brinton s disease or leather bottle stomach is a morphological variant of diffuse or infiltrating stomach cancer causes of linitis plastica could be lye ingestion or metastatic infiltration of the stomach particularly breast and lung carcinoma it is not associated with h pylori infection or chronic gastritis the risk factors are undefined except for rare inherited mutations in e cadherin which are found in about 50 of diffuse type gastric carcinomas this cancer and most other stomach cancers is more common in asian countries particularly japan
in a wireless communication system the link margin measured in db is the difference between the receiver s sensitivity i e the received power at which the receiver will stop working and the actual received power a 15 db link margin means that the system could tolerate an additional 15 db of attenuation between the transmitter and the receiver and it would still just barely work it is typical to design a system with at least a few db of link margin to allow for attenuation that is not modeled elsewhere for example a satellite communications system operating in the tens of gigahertz might require additional link margin vs the link budget assuming lossless propagation in order to ensure that it still works with the extra losses due to rain fade or other external factors a system with a negative link margin would mean the system is insufficient to transfer data usually this means a better receiver is needed with improved sensitivity
the linkage principle is a finding of auction theory it states that auction houses have an incentive to pre commit to revealing all available information about each lot positive or negative the linkage principle is seen in the art market with the age old tradition of auctioneers hiring art experts to examine each lot and pre commit to provide a truthful estimate of its value the discovery of the linkage principle was most useful in determining optimal strategy for countries in the process of auctioning off drilling rights as well as other natural resources such as logging rights in canada an independent assessment of the land in question is now a standard feature of most auctions even if the seller country may believe that the assessment is likely to lower the value of the land rather than confirm or raise a pre existing valuation failure to reveal information leads to the winning bidder incurring the discovery costs himself and lowering his maximum bid due to the expenses incurred in acquiring information if he is not able to get an independent assessment then his bids will take into account the possibility of downside risk both scenarios can be shown to lower the expected revenue of the seller the expected sale price is raised by lowering these discovery costs of the winning bidder and instead providing information to all bidders for free
lipedema or lipoedema european spelling is a chronic disorder of adipose tissue and lymphatic vessel dysfunction described as a bilateral symmetrical flabby swelling of the legs that arises from deposition of adipose tissue starting at the hips and ending at the ankles like riding breeches in some cases the upper arms can also accumulate distinct patterns of fatty tissue lipedema is little known under recognized and generally misdiagnosed as simple obesity lipedema of the legs a syndrome characterized by fat legs and orthostatic edema despite the fact that it s been named for over 75 years as a fat disorder primarily in women it is only recently that interest and education about lipedema is gaining in awareness estimates of the incidence of lipedema vary widely and range as high as 11 of the post pubertal female population with estimates of 17 million women in the us and 370 million women worldwide affected
lipedematous alopecia also known as lipedematous scalp is a disorder characterized by a thick boggy scalp and hair loss
lipid pneumonia or lipoid pneumonia is a specific form of lung inflammation pneumonia that develops when lipids enter the bronchial tree the disorder is sometimes called cholesterol pneumonia in cases where that lipid is a factor
polymorphism in biophysics is the ability of lipids to aggregate in a variety of ways giving rise to structures of different shapes known as phases this can be in the form of spheres of lipid molecules micelles pairs of layers that face one another lamellar phase observed in biological system as a lipid bilayer a tubular arrangement hexagonal or various cubic phases fd 3 m im 3 m ia 3 m pn 3 m and pm 3 m being those discovered so far more complicated aggregations have also been observed such as rhombohedral tetragonal and orthorhombic phases it forms an important part of current academic research in the fields of membrane biophysics polymorphism biochemistry biological impact and organic chemistry synthesis determination of the topology of a lipid system is possible by a number of methods the most reliable of which is x ray diffraction this uses a beam of x rays that are scattered by the sample giving a diffraction pattern as a set of rings the ratio of the distances of these rings from the central point indicates which phase s are present the structural phase of the aggregation is influenced by the ratio of lipids present temperature hydration pressure and ionic strength and type
lipid storage disorders or lipidoses are a group of inherited metabolic disorders in which harmful amounts of lipids fats accumulate in some of the body ’ s cells and tissues people with these disorders either do not produce enough of one of the enzymes needed to metabolize lipids or they produce enzymes that do not work properly over time this excessive storage of fats can cause permanent cellular and tissue damage particularly in the brain peripheral nervous system liver spleen and bone marrow lipids are broadly defined as any fat soluble lipophilic naturally occurring molecule such as fats oils waxes steroids such as cholesterol and estrogen sterols and others lipids are important parts of the membranes found within and between each cell and in the myelin sheath that coats and protects the nerves inside the cells lysosomes convert or metabolize lipids and proteins into smaller components to provide energy for the body
lipiduria or lipuria is the presence of lipids in the urine lipiduria is most frequently observed in nephrotic syndrome where it is passed as lipoproteins along with other proteins it has also been reported as a sign following fat embolism when lipiduria occurs epithelial cells or macrophages contain endogenous fats when filled with numerous fat droplets such cells are called oval fat bodies oval fat bodies exhibit a maltese cross configuration under polarized light microscopy this maltese cross is because of its liquid crystalline structure giving it a double refraction birefringence
lipoatrophia annularis also known as ferreira – marques lipoatrophia is a skin condition affecting primarily women characterized by the loss of subcutaneous fat in the upper extremity it is a form of lipodystrophy
lipoatrophia semicircularis also known as semicircular lipoatrophy is a medical condition in humans commonly known as ribbed thighs it consists of a semicircular zone of atrophy of the subcutaneous fatty tissue located mostly on the front of the thighs skin and underlying muscles remains intact semicircular lipoatrophy mainly affects office workers the ribs in the thighs are typically between 2 and 4 cm high and are typically located at about 72 cm above the ground which is the standard height of office furniture
lipoatrophic diabetes is a type of diabetes mellitus presenting with severe lipodystrophy in addition to the traditional signs of diabetes
lipoatrophy is the term describing the localized loss of fat tissue this may occur as a result of subcutaneous injections of insulin in the treatment of diabetes from the use of human growth hormone or from subcutaneous injections of copaxone used for the treatment of multiple sclerosis in the latter case an injection may produce a small dent at the injection site lipoatrophy occurs in hiv associated lipodystrophy one cause of which is an adverse drug reaction that is associated with some antiretroviral drugs a more general term for an abnormal or degenerative condition of the entire body s adipose tissue is lipodystrophy
benign lipoblastomatosis also known as an embryonic lipoma is a tumor frequently confused with a liposarcoma affecting exclusively infants and young children with approximately 90 occurring before 3 years of age
lipodermatosclerosis also known as chronic panniculitis with lipomembranous changes hypodermitis sclerodermiformis sclerosing panniculitis and stasis panniculitis is a skin and connective tissue disease it is a form of lower extremity panniculitis an inflammation of the layer of fat under the epidermis
lipodystrophy is a medical condition characterized by abnormal or degenerative conditions of the body s adipose tissue lipo is greek for fat and dystrophy is greek for abnormal or degenerative condition a more specific term lipoatrophy is used when describing the loss of fat from one area usually the face this condition is also characterized by a lack of circulating leptin which may lead to osteosclerosis
lipohyalinosis is a small vessel disease in the brain originally defined by fisher as segmental arteriolar wall disorganisation it is characterised by vessel wall thickening and a resultant reduction in luminal diameter fisher considered this small vessel disease to be the result of hypertension induced in the acute stage by fibrinoid necrosis that would lead to occlusion and hence lacunar stroke however recent evidence suggests that endothelial dysfunction as a result of inflammation is a more likely cause for it this may occur subsequent to blood – brain barrier failure and lead to extravasation of serum components into the brain that are potentially toxic lacunar infarction could thus occur in this way and the narrowing – the hallmark feature of lipohyalinosis – may merely be a feature of the swelling occurring around it that squeezes on the structure hypertension is a strong causative factor so called deep perforating arteries – relatively small arteries branching off of relatively large arteries most commonly the lenticulostriate arteries from the middle cerebral artery – are especially prone uncontrolled hypertension and diabetes are risk factors for this condition lacunar infarcts are a result of atherosclerosis microthrombi and lipohyalinosis these affect the deep structures of the brain and may leave small 5 mm cavity lesions chronic familial lipohyalinosis is a rare inherited variant
lipoid congenital adrenal hyperplasia is an endocrine disorder that is an uncommon and potentially lethal form of congenital adrenal hyperplasia cah it arises from defects in the earliest stages of steroid hormone synthesis the transport of cholesterol into the mitochondria and the conversion of cholesterol to pregnenolone — the first step in the synthesis of all steroid hormones lipoid cah causes mineralocorticoid deficiency in affected infants and children male infants are severely undervirilized causing their external genitalia to look feminine the adrenals are large and filled with lipid globules derived from cholesterol
a lipoma is a benign tumor composed of adipose tissue body fat it is the most common benign form of soft tissue tumor lipomas are soft to the touch usually movable and are generally painless many lipomas are small under one centimeter diameter but can enlarge to sizes greater than six centimeters lipomas are commonly found in adults from 40 to 60 years of age but can also be found in younger adults and children some sources claim that malignant transformation can occur while others say this has yet to be convincingly documented
lipomatosis is believed to be an autosomal dominant condition in which multiple lipomas are present on the body many discrete encapsulated lipomas form on the trunk and extremities with relatively few on the head and shoulders in 1993 a genetic polymorphism within lipomas was localized to chromosome 12 q 15 where the hmgic gene encodes the high mobility group protein isoform i c this is one of the most commonly found mutations in solitary lipomatous tumors but lipomas often have multiple mutations reciprocal translocations involving chromosomes 12 q 13 and 12 q 14 have also been observed within although this condition is benign it can sometimes be very painful depending on location of the lipomas some patients who are concerned with cosmetics seek removal of individual lipomas removal can include simple excision endoscopic removal or liposuction other entities which are accompanied by multiple lipomas include proteus syndrome cowden syndrome and related disorders due to pten gene mutations benign symmetric lipomatosis madelung disease dercum s disease familial lipodystrophy hibernomas epidural steroid injections with epidural lipomatosis and familial angiolipomatosis
lipoprotein lipase deficiency also known as familial chylomicronemia syndrome chylomicronemia chylomicronemia syndrome and hyperlipoproteinemia type ia is a rare autosomal recessive lipid disorder caused by a mutation in the gene which codes lipoprotein lipase as a result afflicted individuals lack the ability to produce lipoprotein lipase enzymes necessary for effective breakdown of fatty acids
liposarcoma is a cancer that arises in fat cells in deep soft tissue such as that inside the thigh or in the retroperitoneum liposarcoma is a rare type of cancer that bears a resemblance to fat cells when examined under a microscope they are typically large bulky tumors and tend to have multiple smaller satellites that extend beyond the main confines of the tumor liposarcomas like all sarcomas are rare
lipotoxicity is a metabolic syndrome that results from the accumulation of lipid intermediates in non adipose tissue leading to cellular dysfunction and death the tissues normally affected include the kidneys liver heart and skeletal muscle lipotoxicity is believed to have a role in heart failure obesity and diabetes and is estimated to affect approximately 25 of the adult american population
lipschütz ulcer ulcus vulvae acutum or reactive non sexually related acute genital ulcers english acute ulceration of the vulva is a rare disease characterized by painful genital ulcers fever and lymphadenopathy occurring most commonly but not exclusively in adolescents and young women previously it was described as being more common in virgins it is not a sexually transmitted disease and is often misdiagnosed sometimes as a symptom of behçet s disease lipschütz ulcer is named after benjamin lipschütz who first described it in 1912 the etiology is still unknown although it has been associated with several infectious causes including paratyphoid fever cytomegalovirus mycoplasma pneumoniae and epstein barr virus infection
liquefactive necrosis or colliquative necrosis is a type of necrosis which results in a transformation of the tissue into a liquid viscous mass often it is associated with focal bacterial or fungal infections in liquefactive necrosis the affected cell is completely digested by hydrolytic enzymes resulting in a soft circumscribed lesion consisting of pus and the fluid remains of necrotic tissue dead leukocytes will remain as a creamy yellow pus after the removal of cell debris by white blood cells a fluid filled space is left it is generally associated with abscess formation and is commonly found in the central nervous system
liquid metal embrittlement also known as liquid metal induced embrittlement is a phenomenon of practical importance where certain ductile metals experience drastic loss in tensile ductility or undergo brittle fracture when exposed to specific liquid metals generally a tensile stress either externally applied or internally present is needed to induce embrittlement exceptions to this rule have been observed as in the case of aluminium in the presence of liquid gallium this phenomenon has been studied since the beginning of the 20 th century many of its phenomenological characteristics are known and several mechanisms have been proposed to explain it the practical significance of liquid metal embrittlement is revealed by the observation that several steels experience ductility losses and cracking during hot dip galvanizing or during subsequent fabrication cracking can occur catastrophically and very high crack growth rates have been measured similar metal embrittlement effects can be observed even in the solid state when one of the metals is brought close to its melting point e g cadmium coated parts operating at high temperature this phenomenon is known as solid metal embrittlement
liquid sky is a popular lighting effect used by clubs and similar venues it consists of a laser scanning in a flat beam above the head of the crowd as with most laser displays for the effect to become apparent the air must be misted by a fog machine the fog makes the beam of the laser visible creating a luminous translucent ceiling of light air currents and the diffusion of fresh denser fog create a swirly or marbled effect liquid sky has several advantages over other laser scanning patterns the most notable one is that the effect can be visible for the entire crowd since you do not need to be inside as you would with a tunnel effect it also avoids the controversial problem of crowd scanning where the laser beam comes into direct contact with the crowd possibly causing temporary blindness and sight loss
lisch epithelial corneal dystrophy lecd also known as band shaped and whorled microcystic dystrophy of the corneal epithelium is a rare form of corneal dystrophy first described in 1992 by lisch et al in one study it was linked to chromosomal region xp 22 3 with as yet unknown candidate genes the main features of this disease are bilateral or unilateral gray band shaped and feathery opacities they sometimes take on a form of a whirlpool repeating the known pattern of corneal epithelium renewal abrasion of the epithelium in 3 patients brought only temporary relief with abnormal epithelium regrowth in several months epithelial cells in the zones of opacity were shown to have diffuse cytoplasmic vacuoles with as yet unestablished content
lisfranc injury also known as lisfranc fracture is an injury of the foot in which one or more of the metatarsal bones are displaced from the tarsus the injury is named after jacques lisfranc de st martin 2 april 1790 – 13 may 1847 a french surgeon and gynecologist who described the injury in 1815 after the war of the sixth coalition
a lisp also known as sigmatism is a speech impediment in which a person misarticulates sibilants s z ts dz ʃ ʒ tʃ dʒ these misarticulations often result in unclear speech
lissencephaly which literally means smooth brain is a rare brain formation disorder caused by defective neuronal migration during the 12 th to 24 th weeks of gestation resulting in a lack of development of brain folds gyri and grooves sulci it is a form of cephalic disorder terms such as agyria no gyri or pachygyria broad gyri are used to describe the appearance of the surface of the brain children with lissencephaly generally have significant developmental delays but these vary greatly from child to child depending on the degree of brain malformation and seizure control life expectancy can be shortened generally due to respiratory problems
throughout this universe of basilisk there are a moderate amount of characters featured the characters within basilisk shall now each be noted within an extended article
brazilian inventions and discoveries are items processes techniques or discoveries which owe their existence either partially or entirely to a person born in brazil or to a citizen of brazil bradykinin by mauricio rocha e silva wilson teixeira beraldo and gastão rosenfeld chagas disease pathogen vector host clinical manifestations and epidemiology discovery by carlos chagas chest photofluorography by manuel dias de abreu epidemic typhus pathogen discovery by henrique da rocha lima pion by césar lattes one of the discoverers jatene procedure by adib jatene
canadian inventions are items processes or techniques which owe their existence either partially or entirely to a person born in canada a citizen of canada or a company or organization based out of canada some of these inventions were funded by the national research council of canada nrcc which has been an important factor in innovation and technological advancement
old abingdonians are former pupils of abingdon school england
a list of notable old carthusians who are former pupils of charterhouse school
old norvicensians ons are former pupils of norwich school an independent co educational day school in norwich england it was established in 1096 as an episcopal school by the first bishop of norwich herbert de losinga and is one of the oldest schools in the united kingdom it was later refounded by royal charter in 1547 by edward vi ons may join the old norvicensian club an association for former pupils predecessors include the parrian club a dining society for former pupils of samuel parr s headship in the late 18 th century and the valpeian club after edward valpy in the early 19 th century in 1866 the latter was replaced by the norwich school club which gave rise to the current association for former pupils which emerged at the beginning of the 20 th century this is a dynamic list and may never be able to satisfy particular standards for completeness you can help by expanding it with reliably sourced entries
list of notable old portmuthians that is former pupils of the portsmouth grammar school alumni often join the old portmuthian club founded in 1885
president of the polish scouting and guiding association polish przewodniczący związku harcerstwa polskiego przewodniczący zhp is the highest function in the polish scouting and guiding association zhp wiceprzewodniczący wiceprzewodnicząca zhp vice president is his substitute
world series cricket wsc was a break away professional cricket competition staged between 1977 and 1979 formed by australian business man kerry packer following the refusal of the australian cricket board acb to accept the bid of packer s channel nine to gain exclusive television rights to australia s test matches world series cricket involved matches between wsc australia xi wsc world xi and wsc west indies the teams included leading australian english pakistani south african and west indian players most notably england captain tony greig west indies captain clive lloyd australian captain greg chappell and former australian captain ian chappell the teams played five day supertests and one day international cup matches in australia and the west indies the first wsc game a supertest between the australians and the west indians began at vfl park on 2 december 1977 sixteen supertest five wicket hauls were by players from all three of the wsc teams the first of these was by greg chappell on 1 january 1978 dennis lillee s seven wickets for twenty three runs 7 23 was the best bowling figures in world series cricket and lillee also holds the record for most supertest five wicket hauls with four eight international cup five wicket hauls were taken during world series cricket with andy roberts claiming the first on 3 february 1978 no player took more than one five wicket haul and wsc world xi player garth le roux returned the best figures with five wickets for six runs against wsc australia xi
this is a list of cancer types ordered alphabetically cancer is a group of diseases that involve abnormal increases in the number of cells with the potential to invade or spread to other parts of the body not all tumors or lumps are cancerous benign tumors are not classified as being cancer because they do not spread to other parts of the body there are over 100 different known cancers that affect humans cancers are often described by the body part that they originated in however some body parts contain multiple types of tissue so for greater precision cancers are additionally classified by the type of cell that the tumor cells originated from these types include carcinoma cancers derived from epithelial cells this group includes many of the most common cancers particularly in older adults nearly all cancers developing in the breast prostate lung pancreas and colon are carcinomas sarcoma cancers arising from connective tissue i e bone cartilage fat nerve each of which develop from cells originating in mesenchymal cells outside the bone marrow lymphoma and leukemia these two classes of cancer arise from cells that make blood leukemia is the most common type of cancer in children accounting for about 30 however far more adults develop lymphoma and leukemia germ cell tumor cancers derived from pluripotent cells most often presenting in the testicle or the ovary seminoma and dysgerminoma respectively blastoma cancers derived from immature precursor cells or embryonic tissue blastomas are more common in children than in older adults cancers are usually named using carcinoma sarcoma or blastoma as a suffix with the latin or greek word for the organ or tissue of origin as the root for example cancers of the liver parenchyma arising from malignant epithelial cells is called hepatocarcinoma while a malignancy arising from primitive liver precursor cells is called a hepatoblastoma and a cancer arising from fat cells is called a liposarcoma for some common cancers the english organ name is used for example the most common type of breast cancer is called ductal carcinoma of the breast here the adjective ductal refers to the appearance of the cancer under the microscope which suggests that it has originated in the milk ducts benign tumors which are not cancers are usually named using oma as a suffix with the organ name as the root for example a benign tumor of smooth muscle cells is called a leiomyoma the common name of this frequently occurring benign tumor in the uterus is fibroid confusingly some types of cancer use the noma suffix examples including melanoma and seminoma some types of cancer are named for the size and shape of the cells under a microscope such as giant cell carcinoma spindle cell carcinoma and small cell carcinoma
this list of chiropractic schools is organized alphabetically by country in those countries with functioning specialized accrediting agencies the colleges holding recognized or accredited status are delineated other countries and regions are in the process of developing similar programs of accreditation and in switzerland chiropractic is so fully integrated into the health care system that the existence of a separate accrediting agency is thus obviated the course is taught in university on the same basis as human medicine in 2015 nine internationally accredited chiropractic colleges aecc wioc ifec paris ifec toulouse sdu odense uz zurich uj johannesburg durbin university of technology and macquarie university australia made an open statement which included the teaching of the vertebral subluxation complex as a vitalistic construct that claims that it is the cause of disease is unsupported by evidence its inclusion in a modern chiropractic curriculum in anything other than an historic context is therefore inappropriate and unnecessary this document is based upon and supports the theme of the world federation of chiropractic educational statement formulated in november 2014 at the miami education conference
there are many conditions of or affecting the human circulatory system — the biological system that includes the pumping and channeling of blood to and from the body and lungs with heart blood and blood vessels
the cult of personality is a phenomenon that took place in several countries in the world it consists of production and co production components the cult of personality production is usually state driven and involves control over legal basis opposition the media art and everyday life co production component is driven by the population that internalizes and supports the cult of personality
there are several conditions of or affecting the human integumentary system that are associated with an increased risk of developing nonmelanoma skin cancer i e squamous cell carcinoma and basal cell carcinoma
there are many skin conditions that may occur which are associated with cancers as well as some benign tumors inside the human body
a drainage basin is an extent of land where water from rain and melting snow or ice drains downhill into a body of water such as a river lake reservoir estuary wetland sea or ocean the drainage basin includes both the streams and rivers that convey the water as well as the land surfaces from which water drains into those channels and is separated from adjacent basins by a drainage divide 1 the drainage basin acts like a funnel collecting all the water within the area covered by the basin and channelling it into a waterway each drainage basin is separated topographically from adjacent basins by a geographical barrier such as a ridge hill or mountain which is known as a water divide other terms that are used to describe a drainage basin are catchment catchment area catchment basin drainage area river basin water basin and watershed the drainage basins in south africa do not correspond with the water management areas and have the letters a b c d e f g h j k l m n p q r s t u v w and x where the area a comes close to the same area that the limpopo wma seems to cover apart from these letters they seem to have no name referring to them what seems to be the case though is that each area refers to some major river systems and their tributaries a region for each major river system
an eponymous disease is a disease named after a person usually the physician who first identified the disease or less commonly a patient who suffered from the disease
situs inversus also called situs transversus or oppositus is a congenital condition in which the major visceral organs are reversed or mirrored from their normal positions several fictional characters have reversed organs in the ian fleming novel dr no julius no explains to james bond that he once survived a murder attempt because his heart is located on his right side which his would be killers did not know when they stabbed the spot on the left where the heart of a normal human being would be at the dc comics universe all the inhabitants of earth 3 have their organs in an inverse position and is possible to identify them in this way souther from the anime manga fist of the north star has dextrocardia with situs inversus totalis making him immune to the normal applications of kenshiro s hokuto shinken fighting style since souther s organs — and thus his pressure points — are reversed from where they would normally be during their final confrontation toki reveals souther s condition when kenshiro learns this secret he uses it to great advantage eventually being able to defeat him in an episode of the television show in plain sight an atf agent survives an attempt on his life because his heart is on the right side of his body in the wb series jack jill simon rex played a young man with situs inversus fortune from metal gear solid 2 sons of liberty revolver ocelot points this out when he shoots fortune on the left side of her chest then remembers and states that her heart was on the right side in an er episode entitled freak show romano benton and corday operate on a unique case involving a boy with reversed organs in a story called the trap which h p lovecraft helped write one of the characters is sucked into an interdimensional rift by an antique mirror when he returns his organs and in fact his handedness which hand is dominant are both reversed in margaret mahy s novel the tricksters the character hadfield is said to be an exact mirror image of his otherwise identical twin felix including having his vital organs in mirror image layout in the lord peter wimsey short story the image in the mirror by dorothy sayers a character with reversed organs has long been haunted by dreams of a doppelgänger and by fears that he himself might be only the reflection of someone else in the a e van vogt short story the search the unique trait of people who can travel through time is that they have reversed internal organs in the max brooks novel world war z a character describes operating on a patient who had dextrocardia with situs inversus and transplants a heart from someone with the same condition unbeknownst to him the transplant heart is infected with the virus solanum thus turning the patient into a zombie in the science fiction novel doorways in the sand by roger zelazny the character fred cassidy goes through a device that completely reverses the left right symmetry of his entire body even to the point where he perceives writing and other images as their mirror image the fact that his heart is on the wrong side ends up saving him from being killed by a bullet wound in the science fiction short story technical error by arthur c clarke character richard nelson is inverted laterally in an industrial accident where his body exists in a fourth spatial dimension due to a short circuit at the power plant where he works which caused a strong but unstable magnetic field doctors find he is unable to digest food due to the nutrient molecules being incompatible with his reversed enzymes and receptors efforts to re invert him prove catastrophic in the hindi movie luck 2009 the character ram has his heart on the right side instead of the left which saves his life in audrey niffenegger s novel her fearful symmetry the main characters are mirror twins one of whom valentina has situs inversus in the movie ninja assassin a europol agent mika gets stabbed where her heart should be everyone thinks her to be dead but then raizo proclaims that her heart is special meaning on the right side instead of left and she survives also in the beginning of the movie there is an old man a tattoo artist who should have died 57 years ago from a sword to the heart but survived because his heart was located on the right side of the body as well in 2008 horror movie the broken protagonist gina mcvey a radiologist is seen discussing a patient with dextrocardia situs inversus early in the film in roll call book 3 of the series traces a character called emily wonder has the condition in the manga black jack the protagonist has a patient who has situs inversus totalis in which he operates using a mirror that pinoko provided so that he can see the organs normally helena from the series orphan black was discovered to have situs inversus totalis after surviving a gunshot wound that would otherwise have pierced her heart in doppelgänger 1969 film also known as journey to the far side of the sun astronauts from earth land on a parallel planet on the other side of the sun where everything is a mirror image of what it is on earth when one of the astronauts dies x rays from his post mortem exam reveal that his internal organs are located on the wrong side of his body de rode ridder the main character of the eponymous flemish comic has situs inversus after he passed through a magical mirror album 58 which later on saves his life by making a crossbow bolt narrowly miss his heart album 208
a geological phenomenon is a phenomenon which is explained by or sheds light on the science of geology examples of geological phenomena are 1 mineralogic phenomena 2 lithologic phenomena 3 1 rock types 4 2 1 igneous rock 5 3 2 igneous formation processes 6 4 3 sedimentary rock 7 5 4 sedimentary formation processes sedimentation 8 6 5 quicksand 9 7 6 metamorphic rock 10 endogenic phenomena 11 1 plate tectonics 12 2 1 continental drift 13 3 2 earthquake 14 4 3 oceanic trench 15 5 phenomena associated with igneous activity 16 6 1 geysers and hot springs 17 7 2 bradyseism 18 8 3 volcanic eruption 19 9 earth s magnetic field 20 exogenic phenomena 21 1 slope phenomena 22 2 1 slump 23 3 2 landslide 24 4 weathering phenomena 25 5 1 erosion 26 6 glacial and peri glacial phenomena 27 7 1 glaciation 28 8 2 moraines 29 9 3 hanging valleys 30 10 atmospheric phenomena 31 11 impact phenomena 32 12 1 impact crater 33 coupled endogenic exogenic phenomena 34 1 orogeny 35 2 drainage development 36 3 1 stream capture
there are many conditions of or affecting the human hematologic system — the biological system that includes plasma platelets leukocytes and erythrocytes the major components of blood and the bone marrow
there are four main causes of infections of the central nervous system cns bacterial viral fungal and protozoal
in the majority of nations including all industrialized nations except the united states advances in employee relations have seen the introduction of statutory agreements for minimum employee leave from work — that is the amount of entitlement to paid vacation and public holidays several companies will offer contractually more time depending on the sector companies and the law may also differ as to whether public holidays are counted as part of the minimum leave disparities in national minimums are still subject of debate regarding work life balance and perceived differences between nations these numbers usually refer to full time employment part time workers may get a reduced number of days in most countries public holidays are paid and usually not considered part of the annual leave also in most countries there are additional paid leave benefits such as parental leave and sick leave that are not listed here
a mystery disease is a disease that has not yet been identified reasons for lack of identification of etiology include lack of professional interest difficult access and lack of resources in addition to being unknown to medicine the following is a list of deadly diseases of which the exact cause is unknown separated into long standing and new
a one hit wonder is a top 40 phenomenon the combination of artist and song that scores big in the music industry with one hit but is unable to repeat the achievement with another hit the term can refer to the artist the song or both together the following were notable one hit wonders in english speaking canada many performers who are commonly labelled as one hit wonders in fact had more than one top 40 hit during their careers they may with time come to be remembered for one particular song but cannot be considered true one hit wonders listed here are generally or entirely songs that originated in canada or within the canadian music industry songs from international artists that were one hit wonders elsewhere have frequently been one hit wonders in the canadian market as well meanwhile songs from canadian artists may be listed as one hit wonders elsewhere where the performer had other hits in canada
a one hit wonder is a top 40 phenomenon the combination of artist and song that scores huge in the music industry with one single but is unable to repeat the achievement the term can refer to the artist the song or both together
in many denominations of christianity the ordination of women is a new phenomenon this is true enough that those so ordained gain some attention this list deals with that and will include bishops as well but due to historical differences deaconesses will not be included in presbyterianism methodism and a few other denominations the ordination of women predates 1900 and is now common enough to be unremarkable hence those denominations are not included
this article is a list of notable people who have been diagnosed with pancreatic cancer colin meads former all blacks captain bill hicks american stand up comedian social critic satirist musician joseph cardinal bernardin cardinal archbishop emeritus of chicago william r cotter politician u s congressman from connecticut alan rickman english actor and director sally ride american astronaut first woman astronaut margaret mead american cultural anthropologist and author randy pausch american professor of computer science human – computer interaction and design at carnegie mellon university cmu in pittsburgh pennsylvania ruth bader ginsburg associate justice of the supreme court of the united states willy deville american musician and band member of mink deville alfredo halpern brazilian endocrinologist steve jobs cofounder of apple inc jiddu krishnamurti thinker patrick swayze american actor michael landon american actor fernando lamas argentine born actor arlene dahl s second husband and esther williams s third husband pernell roberts american actor rex harrison british actor joan crawford american actress bonnie franklin american actress donna reed american actress webb pierce country music singer ray price musician country music singer donna douglas american actress known for playing elly mae clampett on the tv series the beverly hillbillies jack benny american radio television and movie actor comedian alfred g gilman american pharmacologist and biochemist satoshi kon japanese film director animator screenwriter and manga artist pete postlethwaite british actor brian lenihan jnr irish politician mark takai american congressman ron smith radio host american radio talk show host on wbal am in baltimore maryland chiyonofuji mitsugu japanese retired sumo wrestler and stablemaster of kokonoe stable
this is a dynamic list and may never be able to satisfy particular standards for completeness you can help by expanding it with reliably sourced entries a brain tumor is an abnormal growth of cells within the brain or inside the skull and can be cancerous malignant or non cancerous benign just over half of all primary brain tumors are malignant the rest are benign though they may still be life threatening in the us in 2000 survivors of benign primary brain tumors outnumbered those who had cancerous primary brain tumors by approximately 4 1 metastatic brain cancer is over six times more common than primary brain cancer as it occurs in about 10 – 30 of all people with cancer this is a list of notable people who have had a primary or metastatic brain tumor either benign or malignant at some time in their lives as confirmed by public information tumor type and survival duration are listed where the information is known blank spaces in these columns appear where precise information has not been released to the public medicine does not designate most long term survivors as cured for primary brain cancer the national cancer institute estimates 22 070 new cases and 12 920 deaths in the us for 2009 the age adjusted incidence rate is 6 4 per 100 000 per year and the death rate is 4 3 per 100 000 per year the lifetime risk of developing brain cancer for someone born today is 0 60 only around a third of those diagnosed with brain cancer survive a further five years these high overall mortality rates are a result of the prevalence of aggressive types such as glioblastoma multiforme nearly 14 of new brain tumor diagnoses occur in persons under 20 years of age
purification in a chemical context is the physical separation of a chemical substance of interest from foreign or contaminating substances pure results of a successful purification process are termed isolate the following list of chemical purification methods should not be considered exhaustive affinity purification is used to purify proteins by retaining them on a column through their affinity to antibodies enzymes or receptors which have been immobilised on the column filtration is a mechanical method to separate solids from liquids or gases by passing the feed stream through a porous sheet such as a cloth or membrane which retains the solids and allows the liquid to pass through centrifugation is a process in which light particles are revolved at high speed with the help of an electric motor so that the fine particles which do not settle at bottom would settle down evaporation is used to remove volatile liquids from non volatile solutes which cannot be done through filtration due to the small size of the substances liquid – liquid extraction removes an impurity or recovers a desired product by dissolving the crude material in a solvent in which other components of the feed material are soluble crystallization separates a product from a liquid feed stream often in extremely pure form by cooling the feed stream or adding precipitants which lower the solubility of the desired product so that it forms crystals the pure solid crystals are then separated from the remaining liquor by filtration or centrifugation recrystallization in analytical and synthetic chemistry work purchased reagents of doubtful purity may be recrystallized e g dissolved in a very pure solvent and then crystallized and the crystals recovered in order to improve and or verify their purity adsorption removes a soluble impurity from a feed stream by trapping it on the surface of a solid material such as activated carbon which forms strong non covalent chemical bonds with the impurity chromatography employs adsorption and desorption on a packed bed of a solid to purify multiple components of a single feed stream smelting is used to produce metals from raw ore and involves adding chemicals to the ore and heating it up to the melting point of the metal refining is used primarily in the petroleum industry whereby crude oil is heated and separated into stages according to the condensation points of the various elements distillation widely used in petroleum refining and in purification of ethanol separates volatile liquids on the basis of their relative volatilities water purification combines a number of methods to produce potable or drinking water downstream processing refers to purification of chemicals pharmaceuticals and food ingredients produced by fermentation or synthesized by plant and animal tissues for example antibiotics citric acid vitamin e and insulin fractionation refers to a purification strategy in which some relatively inefficient purification method is repeatedly applied to isolate the desired substance in progressively greater purity electrolysis refers to the breakdown of substances using an electric current this removes impurities in a substance that an electric current is run through sublimation is the process of changing of any substance usually on heating from a solid to a gas or from gas to a solid without passing through liquid phase bioleaching is the extraction of metals from their ores through the use of living organisms fractional distillation is distillation in fractions
there was an extended royal presence in canada through the 18 th 19 th and 20 th centuries either as an official tour a vacation a period of military service or a viceregal posting by a member of the royal family originally official tours were events predominantly for canadians to see and possibly meet members of their royal family with the associated patriotic pomp and spectacle however nearing the end of the 20 th century such occasions took on the added dimension of a theme and junior members of the royal family began to undertake unofficial working tours of canada as well in this method royal figures are invited by provinces municipalities and other organizations to events which the latter fund without assistance from the federal government the prince of wales the princess royal the duke of york and the prince edward have all made several small tours in this fashion these arrangements then continued on into the 21 st century
the chester city walls surround what was the extent of the english city of chester in the medieval period they started as a defensive structure for the fortress of deva victrix during the roman occupation of britain originating between 70 and 90 ad they consisted of earth ramparts surmounted by wooden palisades at intervals there were wooden gates and towers following the arrival of the legio xx valeria victrix at the end of the 1 st century the walls were reconstructed in sandstone and building work continued with interruptions until the roman circuit of the walls was completed over 100 years later during the same period the towers and gates were rebuilt in stone repairs were carried out on the walls throughout the roman occupation chester was refortified in 907 by æthelflæd but how this affected the walls is not precisely known the north and east roman walls were certainly used in the fortification as they are still in existence today but it is possible that they were extended to the west and south to meet the river dee the full circuit of the walls as they are today was completed by the end of the 12 th century the north and east walls were extended the west and south walls were built and the towers and gates were incorporated only the north and east walls contain towers as the river was thought to be a sufficient defence on the southern and western sides repair of the walls was an ongoing problem during the medieval period and at some time 3 rd century roman altars and tombstones were used as raw materials some of the tombstones are on display in the grosvenor museum the wall and its towers were damaged during the english civil war particularly in the sieges of the city between 1644 and 1646 further rebuilding and repairs were carried out following the war but it was a constant struggle to cope with the scale of the necessary repairs by the 18 th century the walls had outlived their purpose as a defensive structure and were becoming popular as a promenade in 1707 the city assembly spent £ 1 000 equivalent to £ 150 000 in 2015 to repair the walls and to flag the footway distinguished visitors who walked the walls around that time included john wesley and samuel johnson the four major gates were replaced eastgate bridgegate and watergate during the 18 th century and northgate with its associated gaol in 1808 – 10 shortly after 1810 part of the southern section of the walk was demolished to accommodate the yard for the new gaol in 1846 the northeastern corner of the walls was breached by the chester and holyhead railway newgate was opened in 1938 to bridge a new road built to relieve traffic congestion in the city centre and in 1966 st martin s gate was built across the inner ring road the walls tower gates and posterns of the city of chester are recognised as a scheduled monument all the towers associated with the walls have been designated as grade i listed buildings as have all the sections of the wall other than that between bridgegate and the former county hall now used by the university of chester which is listed grade ii the gates are all designated grade i except for old newgate which is grade ii newgate which is grade ii and st martin s gate which is not listed the three grades of listing are defined as follows grade i buildings are of exceptional interest sometimes considered to be internationally important grade ii buildings are particularly important buildings of more than special interest and grade ii buildings are nationally important and of special interest the circuit of the walls extends for 2 miles 3 km rises to a height of 40 feet 12 2 m and is the most complete circuit of roman and medieval defensive town wall in britain the editor of the victoria county history states the walls still in 2000 formed an almost unbroken pathway and a delight to visitors this list starts in the northwest corner with bonewaldesthorne s tower and includes the water tower which is outside the circuit of the walls but connected by a spur wall to bonewaldesthorne s tower it then continues in a clockwise direction starting with the north wall
severe weather phenomena are weather conditions that are hazardous to human life and property
diving disorders are medical conditions specifically arising from underwater diving the signs and symptoms of these may present during a dive on surfacing or up to several hours after a dive divers have to breathe a gas which is at the same pressure as their surroundings ambient pressure which can be much greater than on the surface the ambient pressure underwater increases by 1 standard atmosphere 100 kpa for every 10 metres 33 ft of depth the principal conditions are decompression illness which covers decompression sickness and arterial gas embolism nitrogen narcosis high pressure nervous syndrome oxygen toxicity and pulmonary barotrauma burst lung although some of these may occur in other settings they are of particular concern during diving activities the disorders are caused by breathing gas at the high pressures encountered at depth and divers will often breathe a gas mixture different from air to mitigate these effects nitrox which contains more oxygen and less nitrogen is commonly used as a breathing gas to reduce the risk of decompression sickness at recreational depths up to about 40 metres 130 ft helium may be added to reduce the amount of nitrogen and oxygen in the gas mixture when diving deeper to reduce the effects of narcosis and to avoid the risk of oxygen toxicity this is complicated at depths beyond about 150 metres 500 ft because a helium – oxygen mixture heliox then causes high pressure nervous syndrome more exotic mixtures such as hydreliox a hydrogen – helium – oxygen mixture are used at extreme depths to counteract this
in the mathematics of probability a stochastic process is a random function in practical applications the domain over which the function is defined as a time interval time series or a region of space random field familiar examples of time series include stock market and exchange rate fluctuations signals such as speech audio and video medical data such as a patient s ekg eeg blood pressure or temperature and random movement such as brownian motion or random walks examples of random fields include static images random topographies landscapes or composition variations of an inhomogeneous material
this is a dynamic list and may never be able to satisfy particular standards for completeness you can help by expanding it with reliably sourced entries stuttering alalia syllabaris also known as stammering alalia literalis or anarthria literalis is a speech disorder in which the flow of speech is disrupted by involuntary repetitions and prolongations of sounds syllables words or phrases and involuntary silent pauses or blocks during which the person who stutters is unable to produce sounds the exact etiology of stuttering is unknown both genetics and neurophysiology are thought to contribute there are many treatments and speech language pathology techniques available that may help increase fluency in some stutterers to the point where an untrained ear cannot identify a problem however there is essentially no cure for the disorder at present people who stutter include floor boy william poirier british prime minister winston churchill orator demosthenes king george vi actor james earl jones and country singer mel tillis churchill whose stutter was particularly apparent to 1920 s writers was one of the 30 of stutterers who have an associated speech disorder — a lisp in his case — yet led his nation through world war ii demosthenes stammered and was inarticulate as a youth yet through dedicated practice using methods such as placing pebbles in his mouth became a great orator of ancient greece king george vi hired speech therapist lionel logue to enable him to speak to his empire and logue effectively helped him accomplish this goal this training and its results are the focus of the 2010 film the king s speech james earl jones has stated he was mute for many years of his youth yet he became an actor noted for the power of his voice mel tillis stutters when talking but not when singing many people had their speech impediment only as a child and have overcome their condition
a tidal barrage is an artificial obstruction at the mouth of a tidal watercourse in contrast to a normal barrage along a river s inland course
in computability theory an undecidable problem is a type of computational problem that requires a yes no answer but where there cannot possibly be any computer program that always gives the correct answer that is any possible program would sometimes give the wrong answer or run forever without giving any answer more formally an undecidable problem is a problem whose language is not a recursive set see decidability there are uncountably many undecidable problems so the list below is necessarily incomplete though undecidable languages are not recursive languages they may be subsets of turing recognizable languages i e such undecidable languages may be recursively enumerable many if not most undecidable problems in mathematics can be posed as word problems determining when two distinct strings of symbols encoding some mathematical concept or object represent the same object or not for undecidability in axiomatic mathematics see list of statements undecidable in zfc
there are many longstanding unsolved problems in mathematics for which a solution has still not yet been found the unsolved problems in statistics are generally of a different flavor according to john tukey difficulties in identifying problems have delayed statistics far more than difficulties in solving problems a list of one or two open problems in fact 22 of them was given by david cox
voice disorders are medical conditions involving abnormal pitch loudness or quality of the sound produced by the larynx and thereby affecting speech production these include puberphonia chorditis vocal fold nodules vocal fold cysts vocal cord paresis reinke s edema spasmodic dysphonia foreign accent syndrome bogart – bacall syndrome laryngeal papillomatosis laryngitis
listener fatigue also known as listening fatigue is a phenomenon that occurs after prolonged exposure to an auditory stimulus symptoms include tiredness discomfort pain and loss of sensitivity listener fatigue is not a clinically recognized state but is a term used by many professionals the cause for listener fatigue is still not yet fully understood it is thought to be an extension of the quantifiable psychological perception of sound common groups at risk of becoming victim to this phenomenon include avid listeners of music and others who listen or work with loud noise on a constant basis such as musicians construction workers and military personnel
listeriosis is a bacterial infection most commonly caused by listeria monocytogenes although l ivanovii and l grayi have been reported in certain cases listeria primarily causes infections of the central nervous system meningitis meningoencephalitis brain abscess cerebritis and bacteremia in those who are immunocompromised pregnant women and those at the extremes of age newborns and the elderly as well as gastroenteritis in healthy persons who have been severely infected listeria is ubiquitous and is primarily transmitted via the oral route after ingestion of contaminated food products after which the organism penetrates the intestinal tract to cause systemic infections the diagnosis of listeriosis requires the isolation of the organism from the blood and or the cerebrospinal fluid treatment includes prolonged administration of antibiotics primarily ampicillin and gentamicin to which the organism is usually susceptible
a lithopedion – also spelled lithopaedion or lithopædion – ancient greek λίθος stone ancient greek παιδίον small child infant or stone baby is a rare phenomenon which occurs most commonly when a fetus dies during an abdominal pregnancy is too large to be reabsorbed by the body and calcifies on the outside as part of a maternal foreign body reaction shielding the mother s body from the dead tissue of the fetus and preventing infection lithopedia may occur from 14 weeks gestation to full term it is not unusual for a stone baby to remain undiagnosed for decades and it is often not until a patient is examined for other conditions or a proper examination is conducted that includes an x ray that a stone baby is found the condition was first described in a treatise by the physician abū al qāsim abulcasis in the 10 th century but fewer than 300 cases have been noted in 400 years of medical literature the earliest lithopedion is one found in an archaeological excavation at bering sinkhole on the edwards plateau in kerr county texas dated to 1100 bc another early example was found in a gallo roman archaeological site in costebelle southern france dating to the 4 th century in 1880 german physician friedrich küchenmeister reviewed 47 cases of lithopedia from the medical literature and identified three subgroups lithokelyphos stone sheath where calcification occurs on the placental membrane and not the fetus lithotecnon stone child or true lithopedion where the fetus itself is calcified after entering the abdominal cavity following the rupture of the placental and ovarian membranes and lithokelyphopedion stone sheath and child where both fetus and sac are calcified lithopedia can originate both as tubal or ovarian pregnancies
a lithospheric drip is a geological phenomenon in which a dense and relatively cold mass of lithosphere sinks into the more fluid upper mantle the regions of descending material have been detected by seismic tomography methods and modeled as near vertically oriented cylindrical masses within the upper mantle the lithospheric drip discovered below the great basin in central nevada has dimensions of 100 km diameter by 500 km vertical length another area underlain by a descending cylindrical mass of dense lithosphere has been reported in the southwestern sierra nevada and portions of the san joaquin valley of california here a 100 km by 225 km mass of relatively high density fast p wave velocity has been discovered below an area of anomalous topography
little league elbow is a condition that is caused by repetitive throwing motions especially in children who play sports that involve an overhand throw little leaguer s elbow was first coined by brogdon and crow in an eponymous 1960 article in the american journal of radiology the name of the condition is derived from the game of baseball it is most often seen in young pitchers under the age of sixteen the pitching motion causes a valgus stress to be placed on the elbow joint which can cause damage to the structures of the elbow resulting in an avulsion of the medial epiphyseal plate growth plate the first diagnosis of the injury in 1960 set off a firestorm of controversy regarding how much youth baseball players can and should be asked to pitch the ailment even appeared in the comic strip peanuts in 1963 when charlie brown received a diagnosis in 2007 in order to protect against overuse injuries little league baseball began limiting the number of pitches a player could throw per day adult pitchers do not experience the same injury because they do not have an open growth plate in the elbow instead in adult athletes a more common injury is to the ulnar collateral ligament of the elbow an injury that often requires tommy john surgery in order for the athlete to resume high level competitive throwing
little cherry disease or lchd sometimes referred to as little cherry k s little cherry or sour cherry decline is a viral infectious disease that affects cherry trees most notably sweet cherries prunus avium and sour cherries prunus cerasus little cherry disease should not be confused with cherry buckskin disease which is caused by phytoplasma note that both diseases are among the diseases referred to as cherry decline
littoral cell angioma abbreviated lca and formally known as littoral cell angioma of the spleen is a benign tumour of the spleen that arises from the cells that line the red pulp
livedo racemosa is a cutaneous condition characterized by a skin discoloration appearing as irregular broken circles
livedo reticularis is a common skin finding consisting of a mottled reticulated vascular pattern that appears as a lace like purplish discoloration of the skin the discoloration is caused by swelling of the venules owing to obstruction of capillaries by small blood clots the blood clots in the small blood vessels can be a secondary effect of a condition that increases a person s risk of forming blood clots including a wide array of pathological and nonpathological conditions examples include hyperlipidemia microvascular hematological or anemia states nutritional deficiencies hyper and autoimmune diseases and drugs toxins the condition may be normal or related to more severe underlying pathology its differential diagnosis is broadly divided into possible blood diseases autoimmune rheumatologic diseases cardiovascular diseases cancers and endocrine disorders it can usually in 80 of cases be diagnosed by biopsy it may be aggravated by exposure to cold and occurs most often in the lower extremities the condition s name derives from the latin livere meaning bluish and reticular which refers to the net like appearance
livedoid dermatitis also known as embolia cutis medicamentosa and nicolau syndrome is a rare iatrogenic cutaneous reaction that occurs immediately after a drug injection it presents as an immediate extreme pain around the injection site with overlying skin rapidly becoming erythematous violaceous or blanched ischemic pallor and sometimes with reticular pattern the reaction eventually leads to variable degrees of necrosis to the skin and underlying tissue the wound eventually heals can lead to atrophic disfiguring scarring the reaction is associated with a range of both injection sites and drugs it was first reported by freudenthal in 1924 following an injection of bismuth salts for syphilis although initial reports were following intramuscular injections the reaction has since also been reported following subcutaneous intravenous and intraarticular injections livedoid dermatitis has been reported to occur with many different drug injections including penicillins local anesthetics e g lidocaine vaccines e g dtap corticosteroids nsaids and more
livedoid vasculopathy also known as livedoid vasculitis livedo reticularis with summer winter ulceration and segmental hyalinizing vasculitis is a chronic cutaneous disease seen predominantly in young to middle aged women one synonym used to describe its features is painful purpuric ulcers with reticular pattern of the lower extremities purple it can be divided into a primary or idiopathic form and a secondary form which has been associated with a number of diseases including chronic venous hypertension and varicosities
a liver abscess is a pus filled mass inside the liver common causes are abdominal infections such as appendicitis or diverticulitis due to haematogenous spread through the portal vein
liver cancer also known as hepatic cancer and primary hepatic cancer is cancer that starts in the liver cancer which has spread from elsewhere to the liver known as liver metastasis is more common than that which starts in the liver symptoms of liver cancer may include a lump or pain in the right side below the rib cage other symptoms includes swelling of the abdomen yellowish skin easy bruising weight loss and weakness the leading cause of liver cancer is cirrhosis due to either hepatitis b hepatitis c or alcohol other causes include aflatoxin non alcoholic fatty liver disease and liver flukes the most common types are hepatocellular carcinoma hcc which makes up 80 of cases and cholangiocarcinoma less common types include mucinous cystic neoplasm and intraductal papillary biliary neoplasm the diagnosis may be supported by blood tests and medical imaging with confirmation by tissue biopsy preventive efforts include immunization against hepatitis b and treating those infected with hepatitis b or c screening is recommended in those with chronic liver disease treatment options may include surgery targeted therapy and radiation therapy in certain cases ablation therapy embolization therapy or liver transplantation may be used small lumps in the liver may be simply closely followed primary liver cancer is globally the sixth most frequent cancer 6 and the second leading cause of death from cancer 9 in 2012 it occurred in 782 000 people and resulted in 746 000 deaths in 2013 300 000 deaths from liver cancer were due to hepatitis b 343 000 to hepatitis c and 92 000 to alcohol higher rates of liver cancer occur where hepatitis b and c are common including asia and sub saharan africa males are more often affected with hcc than females diagnosis is most frequent among those 55 to 65 years old five year survival rates are 18 in the united states the word hepatic is from the greek hêpar meaning liver
liver disease also called hepatic disease is a type of damage to or disease of the liver
liver failure or hepatic insufficiency is the inability of the liver to perform its normal synthetic and metabolic function as part of normal physiology two forms are recognised acute and chronic recently a third form of liver failure known as acute on chronic liver failure aclf is increasingly being recognized
a liver injury also known as liver laceration is some form of trauma sustained to the liver this can occur through either a blunt force such as a car accident or a penetrating foreign object such as a knife liver injuries constitute 5 of all traumas making it the most common abdominal injury generally nonoperative management and observation is all that is required for a full recovery
liver spots also known as age spot solar lentigo lentigo senilis old age spot senile freckle are blemishes on the skin associated with aging and exposure to ultraviolet radiation from the sun they range in color from light brown to red or black and are located in areas most often exposed to the sun particularly the hands face shoulders arms and forehead and the scalp if bald the spots derive their name from the fact that they were once incorrectly believed to be caused by liver problems but they are physiologically unrelated to the liver save for a similar color from the age of 40 onward the skin is less able to regenerate from sun exposure and liver spots are very common in this age group particularly in those who spend time in the sun in the overwhelming majority of cases liver spots pose no threat and require no treatment though they occasionally have been known to obscure the detection of skin cancer however despite being a benign condition liver spots are sometimes considered unsightly and some people choose to have them removed this can be done by electrosurgery laser treatment cryotherapy or the use of tretinoin or alpha hydroxy acids
liver tumors or hepatic tumors are tumors or growths on or in the liver medical terms pertaining to the liver often start in hepato or hepatic from the greek word for liver hepar several distinct types of tumors can develop in the liver because the liver is made up of various cell types these growths can be benign or malignant cancerous they may be discovered on medical imaging even for a different reason than the cancer itself or may be present in patients as an abdominal mass hepatomegaly abdominal pain jaundice or some other liver dysfunction
livestock source verification is the ability to trace livestock from birth to the consuming public this process usually entails numeric identification at birth and record keeping which details health records feed records and genetic history of individual livestock the record keeping and traceability process continues from slaughter through processing and distribution these records can be accessed by the processor which provides another level of safety to the consumer in terms of recall if necessary unique numbers are usually assigned to all cows with most activities being documented
living torpedoes polish żywe torpedy also straceńcy — “ desperates ” or the lost was a social and military phenomenon which began in the second polish republic in mid 1939 when the threat from nazi germany became real the idea for creating the human torpedo unit was very similar to the famous japanese kamikaze pilots — males and females willing to sacrifice their lives to defend their homeland it is a matter of debate among military historians whether there were any real plans for the combat usage of such suicidal units or whether it was purely a matter of propaganda it all started on may 5 1939 when adolf hitler officially demanded the free city of danzig and the polish corridor a day after hitler ’ s speech the polish daily ilustrowany kurier codzienny from kraków published a letter written by a man from warsaw named władysław bożyczko and also signed by his relatives the brothers edward and leon lutostański bożyczko together with the lutostański brothers appealed to the poles asking them to sacrifice their lives also as early as spring 1937 a man from katowice stanisław chojecki had written a letter to edward rydz śmigły offering a similar ultimate sacrifice the appeal quickly spread all over the country trumpeted by other newspapers and radio copies of several papers which published it have been preserved to this day in some of them there are names and photographs of some of those who applied the search for volunteers turned into a popular patriotic movement which lasted until the first day of world war ii — september 1 1939 the day the german invasion of poland began it is now difficult to estimate how many people volunteered most probably there were as many as 4700 men and some 150 women 3000 names are documented as the polish navy issued special ids for volunteers signed by commodore eugeniusz poplawski the first people took their oaths on june 29 1939 it is not exactly known what the polish army was going to use these people for presumably they were supposed to man underwater human torpedoes aimed at the destruction of german warships most probably the polish army did not have the necessary equipment but reportedly in the summer of 1939 in gdynia 83 selected volunteers were shown a special short movie about torpedoes manned by humans an officer of the navy who was present stated that poland had 16 such torpedoes they were eight meters long and weighed 420 kilograms however none of the volunteers ever saw these torpedoes some other volunteers were trained as glider pilots and parachute jumpers also at that time the polish navy created a bureau of living torpedoes which suggests that the idea was treated seriously according to one of the volunteers marian kamiński from poznań who saw the movie navy officers told him to return to gdynia on october 12 1939 for a two month training course the course never started — as germany attacked poland on september 1 1939 — but some of the volunteers had by then been drafted into another special ops unit for sabotage and operations behind enemy lines
li – fraumeni syndrome is a rare cancer predisposition hereditary disorder characterized as autosomal dominant it was named after two american physicians frederick pei li and joseph f fraumeni jr who first recognized the syndrome after reviewing the medical records and death certificates of 648 childhood rhabdomyosarcoma patients this syndrome is also known as the sarcoma breast leukaemia and adrenal gland sbla syndrome the syndrome is linked to germline mutations of the p 53 tumor suppressor gene which encodes a transcription factor p 53 that normally regulates the cell cycle and prevents genomic mutations the mutations can be inherited or can arise from de novo mutations early in embryogenesis or in one of the parent s germ cells
lluvia de peces rain of fish is a phenomenon that has allegedly been occurring yearly for more than a century in yoro honduras it is also known as the aguacero de pescado
loa loa filariasis is a skin and eye disease caused by the nematode worm loa loa humans contract this disease through the bite of a deer fly or mango fly chrysops spp the vectors for loa loa the adult loa loa filarial worm migrates throughout the subcutaneous tissues of humans occasionally crossing into subconjunctival tissues of the eye where it can be easily observed loa loa does not normally affect one s vision but can be painful when moving about the eyeball or across the bridge of the nose the disease can cause red itchy swellings below the skin called calabar swellings the disease is treated with the drug diethylcarbamazine dec and when appropriate surgical methods may be employed to remove adult worms from the conjunctiva
load rejection in electric power system is the condition in which there is a sudden load trip in the system which cause the generation side to be over frequency a load rejection test is part of commissioning test for power system to see if the system can withstand the sudden loss of load and return to normal operating condition with its governor on the generation side and test its reliability load bank is normally used for the test
loading characteristic in multichannel telephone systems a plot for the busy hour of the equivalent mean power and the peak power as a function of the number of voice channels the equivalent power of a multichannel signal referred to the zero transmission level point is a function of the number of channels and has for its basis a specified voice channel mean power
a loan covenant is a condition in a commercial loan or bond issue that requires the borrower to fulfill certain conditions or which forbids the borrower from undertaking certain actions or which possibly restricts certain activities to circumstances when other conditions are met typically violation of a covenant may result in a default on the loan being declared penalties being applied or the loan being called the legal provision in the loan agreement providing for the loan to be called is the acceleration clause once the buyer defaults all future payments due under the loan are accelerated and deemed to be due and payable immediately covenants may also be waived either temporarily or permanently usually at the sole discretion of the lender
loan modification is the systematic alteration of mortgage loan agreements that help those having problems making the payments by reducing interest rates monthly payments or principal balances lending institutions could make one or more of these changes to relieve financial pressure on borrowers to prevent the condition of foreclosure loan modifications have been practiced in the united states since the 1930 s during the great depression loan modification programs took place at the state level in an effort to reduce levels of loan foreclosures during the so called great recession of the early 21 st century loan modification became a matter of national policy with various actions taken to alter mortgage loan terms to prevent further economic destabilization
lobar pneumonia is a form of pneumonia that affects a large and continuous area of the lobe of a lung it is one of the two anatomic classifications of pneumonia the other being bronchopneumonia
lobectomy means surgical excision of a lobe this may refer to a lobe of the lung a lobe of the thyroid hemithyroidectomy or a lobe of the brain as in anterior temporal lobectomy
lobomycosis also known as jorge lobo s disease or lacaziosis is a blastomycosis a fungal infection of the skin caused by lacazia loboi formerly named loboa loboi and discovered by brazilian dermatologist jorge lobo other names which were given to the disease are keloidal blastomycosis amazonian blastomycosis blastomycoid granuloma miraip and piraip these last two names were given by natives of the amazon and mean that which burns this disease is usually found in humans and bottle nosed dolphins
lobular carcinoma in situ lcis is a condition caused by unusual cells in the lobules of the breast many do not consider it cancer and many do but all agree it can indicate an increased risk of future cancer the national database registrars however consider lcis a malignancy malignancy of course is cancer unlike ductal carcinoma in situ dcis lcis is not associated with calcification and is typically an incidental finding in a biopsy performed for another reason lcis only accounts for about 15 of the in situ ductal or lobular breast cancers
a lobulation is an appearance resembling lobules for instance the thyroid gland may become large and lobulated in hashimoto s thyroiditis
local extinction or extirpation is the condition of a species or other taxon that ceases to exist in the chosen geographic area of study though it still exists elsewhere local extinctions are contrasted with global extinctions local extinctions may be followed by a replacement of the species taken from other locations wolf reintroduction is an example of this
local gigantism or localised gigantism is a condition in which a certain part of the body acquires larger than normal size due to excessive growth of the anatomical structures or abnormal accumulation of substances it is more common in fingers and toes where it is termed macrodactyly however sometimes an entire limb may be enlarged
a local option is the ability of local political jurisdictions typically counties or municipalities to allow decisions on certain controversial issues based on popular vote within their borders in practice it usually relates to the issue of alcoholic beverage sales as described by an encyclopedia in 1907 local option is the license granted to the inhabitants of a district to extinguish or reduce the sale of intoxicants in their midst a 1911 encyclopædia describes it as specifically used in politics of the power given to the electorate of a particular district to choose whether licences for the sale of intoxicating liquor should be granted or not this form of local option has also been termed local veto local option regarding alcohol was first used in the temperance movement as a means to bring about prohibition gradually in the 1830 s temperance activists mobilized to restrict licenses in towns and counties in new england by the 1840 s temperance reformers demanded state laws to allow local voters to decide whether any liquor licenses would be issued in their localities some 12 states and territories had some form of these early local option laws by the late 1840 s controversy over the measures gave rise to the first major confrontation in the united states over the propriety and constitutionality of ballot box legislation or referendums opponents of local option which included drinkers and liquor dealers many of whom were immigrants argued that local option authorized the tyranny of the majority and infringed upon the rights of the liquor dealing and liquor consuming minority local option as a method of alcohol control made a resurgence after the civil war the anti saloon league initially decided to use local option as the mechanism to bring about nationwide prohibition its intent was to work across the country at the local level in many instances however it was not the agenda for instance several wards in ontario canada passed local option but were vehemently against province wide prohibition preferring to isolate alcohol sales rather than ban them altogether that is particularly evident in toronto s junction neighbourhood part of which remained notoriously dry as late as 2000 the last area of ontario to repeal prohibition following the repeal of national prohibition in the united states in 1933 some states chose to maintain prohibition within their own borders others chose to permit local option on the controversial issue in the remainder of states there was no prohibition overlying the patchwork of prohibition many states known as alcoholic beverage control states decided to establish their own monopolies over the wholesaling and or retailing of alcoholic beverages montgomery county maryland for example has used local option to establish its alcohol control monopoly within its borders
in abstract algebra more specifically ring theory local rings are certain rings that are comparatively simple and serve to describe what is called local behaviour in the sense of functions defined on varieties or manifolds or of algebraic number fields examined at a particular place or prime local algebra is the branch of commutative algebra that studies local rings and their modules in practice a commutative local ring often arises as the result of the localization of a ring at a prime ideal the concept of local rings was introduced by wolfgang krull in 1938 under the name stellenringe the english term local ring is due to zariski
local sleep is a neurological phenomenon where brain activity in an organism that is otherwise awake enters a state which closely resembles that of sleep in an electroencephalogram these patterns generally resemble nrem slow wave sleep and oscillate between on and off periods in the same way that would be expected during an actual sleeping state local sleep can be induced by sustained and intense periods of activation of a particular brain region especially when coupled with sleep deprivation a condition colloquially called sleep drunk although certain cortical regions of mice have been demonstrated to enter local sleep for very brief amounts of time without any immediate trigger unlike microsleep however these brief periods of local sleep occur while the animal is still entirely conscious and functioning although abilities associated with the specific brain region in local sleep tend to decline substantially for instance local sleep in brain regions associated with movement can lead to lapses in coordination and more generally cognitive functioning seems to be somewhat impaired by local sleep of cortical regions with mice undergoing cortical sleep exhibiting far less awareness of their surroundings and having delayed or inappropriate reactions to stimuli while the function of local sleep is not definitively established in at least one study the process has been shown to improve the performance of a task in mice the mechanism behind this is suspected to be shared with the general mechanism driving learning and memory consolidation during sleep
localized granuloma annulare is a skin condition of unknown cause tending to affect children and young to middle aged adults usually appearing on the lateral or dorsal surfaces of the fingers or hands elbows dorsal feet and ankles
localized heat contact urticaria is a cutaneous condition one of the rarest forms of urticaria where within minutes of contact with heat from any source itching and whealing occur at the precise site of contact lasting up to 1 hour
localized lichen myxedematosus is a group of skin condition caused by fibroblasts producing abnormally large amounts of mucopolysaccharides a disease for which there is no treatment
localized lipodystrophy is a skin condition characterized by the loss subcutaneous fat localized to sites of insulin injection
localized pustular psoriasis presents as two distinct conditions that must be considered separate from generalized psoriasis and without systemic symptoms these two distinct varieties being pustulosis palmaris et plantaris and acrodermatitis continua
in mathematics a locally integrable function sometimes also called locally summable function is a function which is integrable so its integral is finite on every compact subset of its domain of definition the importance of such functions lies in the fact that their function space is similar to lp spaces but its members are not required to satisfy any growth restriction on their behavior at infinity in other words locally integrable functions can grow arbitrarily fast at infinity but are still manageable in a way similar to ordinary integrable functions
location estimation in wireless sensor networks is the problem of estimating the location of an object from a set of noisy measurements these measurements are acquired in a distributedmanner by a set of sensors
the treasure of loch arkaig sometimes known as the jacobite gold was a large amount of specie provided by spain to finance the jacobite rising in scotland in 1745 and rumoured still to be hidden at loch arkaig in lochaber
a lock up period also known as a lock in lock out or locked up period is a predetermined amount of time following an initial public offering where large shareholders such as company executives and investors representing considerable ownership are restricted from selling their shares generally a lock up period is a condition of exercising an employee stock option depending on the company the ipo lock up period typically lasts between 90 – 180 days before these shareholders are allowed the right but not the obligation to exercise the option lockups are designed to prevent insiders from liquidating assets too quickly after a company goes public when employees and pre ipo investors initially get their shares or options they sign a contract with the company that typically prohibits trades for the first 90 – 180 days after a future ipo when the company is ready to go public the underwriting bank then reaffirms the existing agreements in new contracts this helps to ensure the market will not disproportionately increase the supply which drives prices downward while lockups used to be simple — usually lasting 180 days for everyone — they ’ ve become increasingly complex usually employees and early investors want shorter lockups so they can cash out sooner while the underwriting banks want longer ones to keep insiders from flooding the market and sinking the share price the company is often somewhere in the middle — wanting to keep employees and investors happy but not wanting it to look like insiders don ’ t have faith in it
in computer science a lock convoy is a performance problem that can occur when using locks for concurrency control in a multithreaded application a lock convoy occurs when multiple threads of equal priority contend repeatedly for the same lock unlike deadlock and livelock situations the threads in a lock convoy do progress however each time a thread attempts to acquire the lock and fails it relinquishes the remainder of its scheduling quantum and forces a context switch the overhead of repeated context switches and underutilization of scheduling quanta degrade overall performance lock convoys often occur when concurrency control primitives such as critical sections serialize access to a commonly used resource such as a memory heap or a thread pool they can sometimes be addressed by using non locking alternatives such as lock free algorithms or by altering the relative priorities of the contending threads
lock is a function that locks part of a keyboard keys into a distinct mode of operation depending on the lock settings selected
locked in syndrome lis is a condition in which a patient is aware but cannot move or communicate verbally due to complete paralysis of nearly all voluntary muscles in the body except for the eyes total locked in syndrome is a version of locked in syndrome wherein the eyes are paralyzed as well fred plum and jerome posner coined the term for this disorder in 1966 locked in syndrome is also known as cerebromedullospinal disconnection de efferented state pseudocoma and ventral pontine syndrome
locked twins is a rare complication of multiple pregnancy where two fetuses become interlocked during presentation before birth it occurs in roughly 1 in 1 000 twin deliveries and 1 in 90 000 deliveries overall most often locked twins are delivered via caesarean section given that the condition has been diagnosed early enough the fetal mortality rate is high for the twin that presents first with over 50 being stillborn
locus heterogeneity is a single disorder trait or pattern of traits caused by mutations in genes at different chromosomal loci for example retinitis pigmentosa has autosomal dominant autosomal recessive and x linked origins however only one mutant locus is needed for the phenotype to manifest other examples are hypertrophic cardiomyopathy osteogenesis imperfecta familial hypercholesterolemia
locution from latin locutio onis a speaking loqui speak is a paranormal phenomenon or supernatural revelation where a religious figure statue or icon speaks usually to a saint phenomena of locutions are described in the lives of christian saints such as saint mary of egypt 5 th century who heard the locution from the icon of virgin mary at the holy sepulchre or in case of the saint henry of coquet island d 1127 who experienced the locution from the figure of christ crucified
in ireland a lodgement is an amount lodged to a bank account or paid in to a bank account via a lodgement slip or paying in slip in india a lodgement is commonly used for proofs of tax deduction a lodgement vendor is one who will verify proofs rental receipts medical receipts to ensure that they are eligible for deduction as per the rules of income tax in india in australia the electronic placing of personal tax returns with the authorities is described as the electronic lodgment note alternate spelling of tax returns
loeys – dietz syndrome lds is an autosomal dominant genetic connective tissue disorder the disorder is marked by aneurysms in the aorta often in children the aorta may also undergo sudden dissection in the weakened layers of the wall of aorta aneurysms and dissections also can occur in arteries other than the aorta because aneurysms in children tend to rupture early children are at greater risk for dying if the syndrome is not identified surgery to repair aortic aneurysms is essential for treatment there are four types of the syndrome labelled types i through iv which are distinguished by their genetic cause type 1 type 2 type 3 and type 4 are caused by mutations in tgfbr 1 tgfbr 2 smad 3 and tgfb 2 respectively these four genes encoding transforming growth factors play a role in cell signaling that promotes growth and development of the body s tissues mutations of these genes cause production of proteins without function although the disorder has an autosomal pattern of inheritance this disorder results from a new gene mutation in 75 of cases and occurs in people with no history of the disorder in their family it has features similar to marfan syndrome and ehlers danlos syndrome it was identified and characterized by pediatric geneticists bart loeys and harry dietz at johns hopkins university in 2005
the loft jazz scene was a cultural phenomenon that occurred in new york city during the mid 1970 s at venues such as environ ali s alley and studio rivbea all in former industrial loft spaces in nyc s soho district hence loft jazz the scene was documented by peter occhiogrosso gary giddins the late robert palmer author producer and stanley crouch many of the musicians featured were from chicago and particularly the association for the advancement of creative musicians aacm and st louis black artists group bag these included notables such as the art ensemble of chicago muhal richard abrams anthony braxton dave holland rashied ali charles tyler perry robinson john fischer jeanne lee oliver lake joseph bowie keshavan maslak hamiett bluiett chico freeman olu dara george lewis air the revolutionary ensemble and anthony davis others came from southern california such as arthur blythe and david murray and from texas like sam rivers loft jazz was a continuation of the free jazz and avant garde jazz traditions inaugurated by john coltrane ornette coleman albert ayler pharoah sanders and sun ra however it didn t follow any one particular style or idiom of jazz few loft jazz musicians played continuously atonal or arhythmic music in the style of coltrane s legendary albums ascension and om they often combined conventional melodic elements with free jazz used instruments less familiar to jazz such as the bass saxophone oboe and cello and combined instruments in nontraditional formats like the world saxophone quartet whose changing members used a variety of saxophones and flutes usually without any rhythm section
a log jam is an accumulation of large wood commonly defined as pieces of wood more than 10 cm in diameter and more than one metre long also commonly called large woody debris that can span an entire stream or river channel historically in north america large log rafts were common across the continent prior to european settlement the most famous natural wood raft is the great raft on louisiana s red river which prior to removal in the 1830 s affected between 390 – 480 km of the main channel it has been suggested that such extensive log rafts may have been common in europe in pre history
in mathematics the logarithmic integral function or integral logarithm li x is a special function it is relevant in problems of physics and has number theoretic significance occurring in the prime number theorem as an estimate of the number of prime numbers less than a given value
logic centralization is a design pattern applied within the service orientation design paradigm whose application aims to increase the reusability potential of agnostic logic by ensuring that services do not contain redundant agnostic logic and that any reusable logic should only be represented by a service that has the most suitable functional context
in psychology logorrhea or logorrhoea from ancient greek λόγος logos word and ῥέω rheo to flow is a communication disorder expressed by excessive wordiness with minor or sometimes incoherent talkativeness logorrhea is sometimes classified as a mental illness resulting in a variety of psychiatric and neurological disorders including aphasia localized cortical lesions in the thalamus mania or most typically in catatonic schizophrenia examples of logorrhea might include talking or mumbling monotonously either to others or more likely to oneself this may include the repetition of particular words or phrases often incoherently the causes of logorrhea remain poorly understood but appear to be localized to frontal lobe structures known to be associated with language as is the case for example in emotional lability in a wide variety of neurological conditions other symptoms take priority in clinical management and research efforts other symptoms include excessive talking words that avoid any logic or reason words that may offend other people and random words which hearers may ascribe unintended meaning to logorrhea should not be confused with pressure of speech which is characterized by the flighty alternation from topic to topic by tenuous links such as rhyming or punning logorrhea is a symptom of an underlying illness and should be treated by a medical professional several possible causes of logorrhea respond well to medication
loin pain hematuria syndrome or lphs is the combination of debilitating unilateral or bilateral flank pain and microscopic or macroscopic amounts of blood in the urine that is otherwise unexplained loin pain hematuria syndrome lphs is a poorly defined disorder characterized by recurrent or persistent loin flank pain and hematuria that appears to represent glomerular bleeding most patients present with both manifestations but some present with loin pain or hematuria alone pain episodes are rarely associated with low grade fever and dysuria but urinary tract infection is not present the major causes of flank pain and hematuria such as nephrolithiasis and blood clot are typically not present renal arteriography may suggest focally impaired cortical perfusion while renal biopsy showed interstitial fibrosis and arterial sclerosis the pain is typically severe and narcotic therapy is often prescribed as a way to manage chronic pain sleep can be difficult because the supine position increases pressure on the flank the onset of pain is often associated with nausea and vomiting making pain management by oral opiates complicated
the london moment is a quantum mechanical phenomenon whereby a spinning superconductor generates a magnetic field whose axis lines up exactly with the spin axis the term may also refer to the magnetic moment of any rotation of any superconductor caused by the electrons lagging behind the rotation of the object although the field strength is independent of the charge carrier density in the superconductor
long chain 3 hydroxyacyl coenzyme a dehydrogenase deficiency often shortened to lchad deficiency is a rare autosomal recessive fatty acid oxidation disorder that prevents the body from converting certain fats into energy this can become life threatening particularly during periods of fasting
the long term complications of standing are the conditions that may arise after prolonged time in a standing or upright position including standing walking or running many of the complications come from prolonged standing more the 60 of a work day that is repeated several times a week there are many different jobs that require prolonged standing these included retail staff baristas bartenders assembly line workers security staff engineers catering staff library assistants hair stylists and laboratory technicians cornell university has calculated that standing requires 20 more energy than sitting
the long term effects of alcohol ethanol consumption range from cardioprotective health benefits for low to moderate alcohol consumption in industrialized societies with higher rates of cardiovascular disease to severe detrimental effects in cases of chronic alcohol abuse health effects associated with alcohol intake in large amounts include an increased risk of alcoholism malnutrition chronic pancreatitis alcoholic liver disease and cancer in addition damage to the central nervous system and peripheral nervous system can occur from chronic alcohol abuse the long term use of alcohol is capable of damaging nearly every organ and system in the body the developing adolescent brain is particularly vulnerable to the toxic effects of alcohol in addition the developing fetal brain is also vulnerable and fetal alcohol spectrum disorders fasds may result if pregnant mothers consume alcohol the inverse relation in western cultures between alcohol consumption and cardiovascular disease has been known for over 100 years many physicians do not promote alcohol consumption however given the many health concerns associated with it some suggest that alcohol should be regarded as a recreational drug and promote exercise and good nutrition to combat cardiovascular disease others have argued that the benefits of moderate alcohol consumption may be outweighed by other increased risks including those of injuries violence fetal damage liver disease and certain forms of cancer withdrawal effects and dependence are also almost identical alcohol at moderate levels has some positive and negative effects on health the negative effects include increased risk of liver diseases oropharyngeal cancer esophageal cancer and pancreatitis conversely moderate intake of alcohol may have some beneficial effects on gastritis and cholelithiasis of the total number of deaths and diseases caused by alcohol most happen to the majority of the population who are moderate drinkers rather than the heavy drinker minority chronic alcohol misuse and abuse has serious effects on physical and mental health chronic excess alcohol intake or alcohol dependence can lead to a wide range of neuropsychiatric or neurological impairment cardiovascular disease liver disease and malignant neoplasms the psychiatric disorders which are associated with alcoholism include major depression dysthymia mania hypomania panic disorder phobias generalized anxiety disorder personality disorders schizophrenia suicide neurologic deficits e g impairments of working memory emotions executive functions visuospatial abilities and gait and balance and brain damage alcohol dependence is associated with hypertension coronary heart disease and ischemic stroke cancer of the respiratory system and also cancers of the digestive system liver breast and ovaries heavy drinking is associated with liver disease such as cirrhosis excessive alcohol consumption can have a negative impact on aging recent studies have focused on understanding the mechanisms by which moderate alcohol consumption confers cardiovascular benefit
long qt syndrome lqts is a rare congenital and inherited or acquired heart condition in which delayed repolarization of the heart following a heartbeat increases the risk of episodes of torsades de pointes tdp a form of irregular heartbeat that originates from the ventricles these episodes may lead to fainting and sudden death due to ventricular fibrillation episodes may be provoked by various stimuli depending on the subtype of the condition the condition is named for the appearance of the electrocardiogram ecg ekg on which a prolongation of the qt interval occurs normally the qt interval duration is between 350 and 440 milliseconds in some individuals the qt prolongation occurs after the administration of certain medications which may be dangerous in addition to medications long qt syndrome can be acquired from malnutrition leading to low blood potassium or low blood magnesium as in anorexia nervosa
long face syndrome also referred to as skeletal open bite is a condition generally caused by childhood mouth breathing however a decreased airway size due to edema an obstruction or genetics are other contributing factors if the cause is mouth breathing it generally occurs when children are unable to breathe through their noses which changes the child s bite while they are still growing the condition s most striking symptom is an excessively long lower face height treatment for the cosmetic effects of long face syndrome after childhood where little potential for growth is possible is surgical the surgery performed is normally a dentofacial osteotomy
long live our noble duke is an alteration traditionally made within the historic county boundaries of lancashire to the anthem god save the queen the anthem still uses the same lyrics and instrumental tune but the second line long live our noble queen is changed to long live our noble duke out of respect to the reigning monarch in their capacity as the duke of lancaster the title is always held by the monarch as head of the royal duchy of lancaster historically lancaster being the county town of lancashire no matter if the sovereign is male or female they always retain the style of duke therefore the variant second line never changes even if god save the queen changes to god save the king and vice versa an unofficial lancashire anthem it is often used at formal dinners in the historical county and in lancastrian regiments of the armed forces this version of the anthem is used every sunday at the savoy chapel which is governed by the duchy of lancaster another version recorded to have been used at the savoy chapel is god save our duke the king long live or noble duke this being in 1951 when king george vi was monarch the variant alters lines 1 and 2 in the original national lyrics
the longest common subsequence lcs problem is the problem of finding the longest subsequence common to all sequences in a set of sequences often just two sequences it differs from problems of finding common substrings unlike substrings subsequences are not required to occupy consecutive positions within the original sequences the longest common subsequence problem is a classic computer science problem the basis of data comparison programs such as the diff utility and has applications in bioinformatics it is also widely used by revision control systems such as git for reconciling multiple changes made to a revision controlled collection of files
in computer science the longest palindromic substring or longest symmetric factor problem is the problem of finding a maximum length contiguous substring of a given string that is also a palindrome for example the longest palindromic substring of bananas is anana the longest palindromic substring is not guaranteed to be unique for example in the string abracadabra there is no palindromic substring with length greater than three but there are two palindromic substrings with length three namely aca and ada in some applications it may be necessary to return all maximal palindromic substrings that is all substrings that are themselves palindromes and cannot be extended to larger palindromic substrings rather than returning only one substring or returning the maximum length of a palindromic substring found a linear time algorithm for listing all the palindromes that appear at the start of a given string however as observed e g by the same algorithm can also be used to find all maximal palindromic substrings anywhere within the input string again in linear time therefore it provides a linear time solution to the longest palindromic substring problem alternative linear time solutions were provided by and by who described a solution based on suffix trees efficient parallel algorithms are also known for the problem the longest palindromic substring problem should not be confused with the different problem of finding the longest palindromic subsequence
in graph theory and theoretical computer science the longest path problem is the problem of finding a simple path of maximum length in a given graph a path is called simple if it does not have any repeated vertices the length of a path may either be measured by its number of edges or in weighted graphs by the sum of the weights of its edges in contrast to the shortest path problem which can be solved in polynomial time in graphs without negative weight cycles the longest path problem is np hard meaning that it cannot be solved in polynomial time for arbitrary graphs unless p np stronger hardness results are also known showing that it is difficult to approximate however it has a linear time solution for directed acyclic graphs which has important applications in finding the critical path in scheduling problems
the longest uncrossed or nonintersecting knight s path is a mathematical problem involving a knight on the standard 8 × 8 chessboard or more generally on a square n × n board the problem is to find the longest path the knight can take on the given board such that the path does not intersect itself a further distinction can be made between a closed path which ends on the same field as where it begins and an open path which ends on a different field from where it begins
a longitudinal mode of a resonant cavity is a particular standing wave pattern formed by waves confined in the cavity the longitudinal modes correspond to the wavelengths of the wave which are reinforced by constructive interference after many reflections from the cavity s reflecting surfaces all other wavelengths are suppressed by destructive interference a longitudinal mode pattern has its nodes located axially along the length of the cavity transverse modes with nodes located perpendicular to the axis of the cavity may also exist
the look elsewhere effect is a phenomenon in the statistical analysis of scientific experiments particularly in complex particle physics experiments where an apparently statistically significant observation may have actually arisen by chance because of the size of the parameter space to be searched once the possibility of look elsewhere error in an analysis is acknowledged it can be compensated for by careful application of standard mathematical techniques more generally known in statistics as the problem of multiple comparisons the term gained some media attention in 2011 in the context of the search for the higgs boson at the large hadron collider
a loop in mathematics in a topological space x is a continuous function f from the unit interval i 0 1 to x such that f 0 f 1 in other words it is a path whose initial point is equal to the terminal point a loop may also be seen as a continuous map f from the pointed unit circle s 1 into x because s 1 may be regarded as a quotient of i under the identification of 0 with 1 the set of all loops in x forms a space called the loop space of x
loop marks are a cutaneous condition and perhaps the single most characteristic finding in child abuse
loop modeling is a problem in protein structure prediction requiring the prediction of the conformations of loop regions in proteins with or without the use of a structural template computer programs that solve these problems have been used to research a broad range of scientific topics from adp to breast cancer because protein function is determined by its shape and the physiochemical properties of its exposed surface it is important to create an accurate model for protein ligand interaction studies the problem arises often in homology modeling where the tertiary structure of an amino acid sequence is predicted based on a sequence alignment to a template or a second sequence whose structure is known because loops have highly variable sequences even within a given structural motif or protein fold they often correspond to unaligned regions in sequence alignments they also tend to be located at the solvent exposed surface of globular proteins and thus are more conformationally flexible consequently they often cannot be modeled using standard homology modeling techniques more constrained versions of loop modeling are also used in the data fitting stages of solving a protein structure by x ray crystallography because loops can correspond to regions of low electron density and are therefore difficult to resolve regions of a structural model that are predicted by non template based loop modeling tend to be much less accurate than regions that are predicted using template based techniques the extent of the inaccuracy increases with the number of amino acids in the loop the loop amino acids side chains dihedral angles are often approximated from a rotamer library but can worsen the inaccuracy of side chain packing in the overall model andrej sali s homology modeling suite modeller includes a facility explicitly designed for loop modeling by a satisfaction of spatial restraints method all methods require an upload of the pdb file and some require the specification of the loop location
in parallel computing loop scheduling is the problem of assigning proper iterations of parallelizable loops among n processors to achieve load balancing and maintain data locality with minimum dispatch overhead typical loop scheduling methods are static even scheduling evenly divide loop iteration space into n chunks and assign each chunk to a processor dynamic scheduling a chunk of loop iteration is dispatched at runtime by an idle processor when the chunk size is 1 iteration it is also called self scheduling guided scheduling similar to dynamic scheduling but the chunk sizes per dispatch keep shrinking until reaching a preset value
in computer science a loop variant is a mathematical function defined on the state space of a computer program whose value is monotonically decreased with respect to a strict well founded relation by the iteration of a while loop under some invariant conditions thereby ensuring its termination a loop variant whose range is restricted to the non negative integers is also known as a bound function because in this case it provides a trivial upper bound on the number of iterations of a loop before it terminates however a loop variant may be transfinite and thus is not necessarily restricted to integer values a well founded relation is characterized by the existence of a minimal element of every non empty subset of its domain the existence of a variant proves the termination of a while loop in a computer program by well founded descent a basic property of a well founded relation is that it has no infinite descending chains therefore a loop possessing a variant will terminate after a finite number of iterations as long as its body terminates each time a while loop or more generally a computer program that may contain while loops is said to be totally correct if it is partially correct and it terminates
the term lordosis refers to the normal inward lordotic curvature of the lumbar and cervical regions of the spine excessive curvature of the lower back is known as lumbar hyperlordosis commonly called hollow back or saddle back after a similar condition that affects some horses a major feature of lumbar hyperlordosis is a forward pelvic tilt resulting in the pelvis resting on top of the thighs curvature in the opposite convex direction in the thoracic and sacral regions is termed kyphotic when this curvature is excessive it is called kyphosis or hyperkyphosis
in mathematical optimization statistics decision theory and machine learning a loss function or cost function is a function that maps an event or values of one or more variables onto a real number intuitively representing some cost associated with the event an optimization problem seeks to minimize a loss function an objective function is either a loss function or its negative sometimes called a reward function a profit function a utility function a fitness function etc in which case it is to be maximized in statistics typically a loss function is used for parameter estimation and the event in question is some function of the difference between estimated and true values for an instance of data the concept as old as laplace was reintroduced in statistics by abraham wald in the middle of the 20 th century in the context of economics for example this is usually economic cost or regret in classification it is the penalty for an incorrect classification of an example in actuarial science it is used in an insurance context to model benefits paid over premiums particularly since the works of harald cramér in the 1920 s in optimal control the loss is the penalty for failing to achieve a desired value in financial risk management the function is precisely mapped to a monetary loss
loss of significance is an undesirable effect in calculations using finite precision arithmetic it occurs when an operation on two numbers increases relative error substantially more than it increases absolute error for example in subtracting two nearly equal numbers known as catastrophic cancellation the effect is that the number of significant digits in the result is reduced unacceptably ways to avoid this effect are studied in numerical analysis
loudspeaker acoustics is a subfield of acoustical engineering concerned with the reproduction of sound and the parameters involved in doing so in actual equipment engineers measure the performance of drivers and complete speaker systems to characterize their behavior often in an anechoic chamber outdoors or using time windowed measurement systems all to avoid including room effects e g reverberation in the measurements designers use models from electrical filter theory to predict the performance of drive units in different enclosures now almost always based on the work of a n thiele and richard small important driver characteristics are frequency response off axis response dispersion pattern lobing sensitivity db spl for 1 watt input maximum power handling non linear distortion colouration i e more or less delayed resonance it is the performance of a loudspeaker listening room combination that really matters as the two interact in multiple ways there are two approaches to high quality reproduction one ensures the listening room be reasonably alive with reverberant sound at all frequencies in which case the speakers should ideally have equal dispersion at all frequencies in order to equally excite the reverberant fields created by reflections off room surfaces the other attempts to arrange the listening room to be dead acoustically leaving indirect sound to the dispersion of the speakers need only be sufficient to cover the listening positions a dead or inert acoustic may be best especially if properly filled with surround reproduction so that the reverberant field of the original space is reproduced realistically this is currently quite hard to achieve and so ideal loudspeaker systems for stereo reproduction would have a uniform dispersion at all frequencies listening to sound in an anechoic dead room is quite different from listening in a conventional room and while revealing about loudspeaker behaviour it has an unnatural sonic character that some listeners find uncomfortable conventional stereo reproduction is more natural if the listening environment has some acoustically reflective surfaces it is in large part the directional properties of speaker systems which vary with frequency that make them sound different even when they measure similarly well on axis acoustical engineering in this instance is concerned with adapting these variations to each other
louis vivet also louis vivé or vive was one of the first mental health patients to be diagnosed with dissociative identity disorder colloquially known as multiple or split personalities within one year of his diagnosis the term multiple personality appeared in psychological literature in direct reference to vivet
louping ill also known as ovine encephalomyelitis infectious encephalomyelitis of sheep trembling ill is an acute viral disease primarily of sheep that is characterized by a biphasic fever depression ataxia muscular incoordination tremors posterior paralysis coma and death louping ill is a tick transmitted disease whose occurrence is closely related to the distribution of the primary vector the sheep tick ixodes ricinus it also causes disease in red grouse and can affect humans the name louping ill is derived from an old scottish word describing the effect of the disease in sheep whereby they loup or spring into the air
in graph theory the lovász conjecture 1969 is a classical problem on hamiltonian paths in graphs it says every finite connected vertex transitive graph contains a hamiltonian path originally lovász stated the problem in the opposite way butthis version became standard in 1996 babai published a conjecture sharply contradicting this conjecture but both conjectures remain widely open it is not even known if a single counterexample would necessarily lead to a series of counterexamples
in information theory a low density parity check ldpc code is a linear error correcting code a method of transmitting a message over a noisy transmission channel an ldpc is constructed using a sparse bipartite graph ldpc codes are capacity approaching codes which means that practical constructions exist that allow the noise threshold to be set very close or even arbitrarily close on the bec to the theoretical maximum the shannon limit for a symmetric memoryless channel the noise threshold defines an upper bound for the channel noise up to which the probability of lost information can be made as small as desired using iterative belief propagation techniques ldpc codes can be decoded in time linear to their block length ldpc codes are finding increasing use in applications requiring reliable and highly efficient information transfer over bandwidth or return channel constrained links in the presence of corrupting noise implementation of ldpc codes has lagged behind that of other codes notably turbo codes the fundamental patent for turbo codes expired on august 29 2013 us 5446747 ldpc codes are also known as gallager codes in honor of robert g gallager who developed the ldpc concept in his doctoral dissertation at the massachusetts institute of technology in 1960
low grade fibromyxoid sarcoma lgfms is a rare type of low grade sarcoma first described by harry evans in 1987 it is characterized by a long and indolent clinical course and the possibility of local recurrence or distant metastases in a subset of patients unlike many other types of cancer low grade fibromyxoid sarcoma can metastasize after many years sometimes decades after the initial presentation of the tumor
in mathematics low rank approximation is a minimization problem in which the cost function measures the fit between a given matrix the data and an approximating matrix the optimization variable subject to a constraint that the approximating matrix has reduced rank the problem is used for mathematical modeling and data compression the rank constraint is related to a constraint on the complexity of a model that fits the data in applications often there are other constraints on the approximating matrix apart from the rank constraint e g non negativity and hankel structure low rank approximation is closely related to principal component analysis factor analysis total least squares latent semantic analysis and orthogonal regression
low set ears are ears with depressed positioning of the pinna two or more standard deviations below the population average it can be associated with conditions such as down s syndrome turner syndrome noonan syndrome patau syndrome digeorge syndrome cri du chat syndrome edwards syndrome it is usually bilateral but can be unilateral in goldenhar syndrome
low back pain lbp is a common disorder involving the muscles nerves and bones of the back pain can vary from a dull constant ache to a sudden sharp feeling low back pain may be classified by duration as acute pain lasting less than 6 weeks sub chronic 6 to 12 weeks or chronic more than 12 weeks the condition may be further classified by the underlying cause as either mechanical non mechanical or referred pain the symptoms of low back pain usually improve within a few weeks from the time they start with 40 90 of people completely better by six weeks in most episodes of low back pain a specific underlying cause is not identified or even looked for with the pain believed to be due to mechanical problems such as muscle or joint strain if the pain does not go away with conservative treatment or if it is accompanied by red flags such as unexplained weight loss fever or significant problems with feeling or movement further testing may be needed to look for a serious underlying problem in most cases imaging tools such as x ray computed tomography are not useful and carry their own risks despite this the use of imaging in low back pain has increased some low back pain is caused by damaged intervertebral discs and the straight leg raise test is useful to identify this cause in those with chronic pain the pain processing system may malfunction causing large amounts of pain in response to non serious events the treatment of acute nonspecific low back pain of rapid onset is typically with simple pain medications and the continuation of as much normal activity as the pain allows medications are recommended for the duration that they are helpful with paracetamol also known as acetaminophen as the preferred first medication a number of other options are available for those who do not improve with usual treatment opioids may be useful if simple pain medications are not enough but they are not generally recommended due to side effects surgery may be beneficial for those with disc related chronic pain and disability or spinal stenosis no clear benefit has been found for other cases of non specific low back pain low back pain often affects mood which may be improved by counseling or antidepressants additionally there are many alternative medicine therapies including the alexander technique and herbal remedies but there is not enough evidence to recommend them confidently the evidence for chiropractic care and spinal manipulation is mixed approximately 9 to 12 of people 632 million have lbp at any given point in time and nearly 25 report having it at some point over any one month period about 40 of people have lbp at some point in their lives with estimates as high as 80 among people in the developed world difficulty most often begins between 20 and 40 years of age men and women are equally affected low back pain is more common among people aged 40 – 80 years with the overall number of individuals affected expected to increase as the population ages
low pressure hydrocephalus lph is a condition whereby ventricles are enlarged and the individual experiences severe dementia inability to walk and incontinence despite very low intracranial pressure icp low pressure hydrocephalus appears to be a more acute form of normal pressure hydrocephalus if not diagnosed in a timely fashion the individual runs the risk of remaining in the low pressure hydrocephalic state or lphs shunt revisions even when they are set to drain at a low icp are not always effective the pressure in the brain does not get high enough to allow the cerebrospinal fluid to drain in a shunt system therefore the shunt is open but malfunctioning in lph in cases of lph chronic infarcts can also develop along the corona radiata in response to the tension in the brain as the ventricles increase in size certain causes of lph include trauma tumor bleeding inflammation of the lining of the brain whole brain radiation as well as other brain pathology that affects the compliance of the brain parenchyma one treatment for the lphs is an external ventricular drain evd set at negative pressures according to pang altschuler et al a controlled steady negative pressure siphoning with evd carefully monitored with partial computer tomography scans is a safe and effective way of treating lph in their experience this approach helps restore the brain mantle they caution against dropping or raising the pressure of the evd too quickly as it increases risk and also destabilizes the ventricles getting the ventricles smaller is the initial step stabilising them is the second step before placing a shunt – which is the final step in therapy any variation from this formula can lead to an ineffective yet patent shunt system despite a low pressure setting care should be taken with evd therapy as mismanagement of the evd can lead to long term permanent complications and brain injury
lower gastrointestinal bleeding commonly abbreviated lgib is any form of gastrointestinal bleeding in the lower gastrointestinal tract lgib is a common ailment seen at emergency departments it presents less commonly than upper gastrointestinal bleeding ugib it is estimated that ugib accounts for 100 – 200 per 100 000 cases versus 20 – 27 per 100 000 cases for lgib approximately 85 of lower gastrointestinal bleeding involves the colon 10 are from bleeds that are actually upper gastrointestinal bleeds and 3 – 5 involve the small intestines
a lower motor neuron lesion is a lesion which affects nerve fibers traveling from the ventral horn or anterior grey column of the spinal cord to the relevant muscle s – the lower motor neuron one major characteristic used to identify a lower motor neuron lesion is flaccid paralysis – paralysis accompanied by loss of muscle tone this is in contrast to an upper motor neuron lesion which often presents with spastic paralysis – paralysis accompanied by severe hypertonia
lower respiratory tract infection lrti while often used as a synonym for pneumonia can also be applied to other types of infection including lung abscess and acute bronchitis symptoms include shortness of breath weakness fever coughing and fatigue there are a number of symptoms that are characteristic of lower respiratory tract infections the two most common are bronchitis and pneumonia influenza affects both the upper and lower respiratory tracts antibiotics are the first line treatment for pneumonia however they are not effective or indicated for parasitic or viral infections acute bronchitis typically resolves on its own with time in 2013 there were about 150 million lrtis these resulted in 2 7 million deaths down from 3 4 million deaths in 1990 this was 4 8 of all deaths in 2013
in mathematics the lowest common denominator or least common denominator abbreviated lcd is the least common multiple of the denominators of a set of fractions it simplifies adding subtracting and comparing fractions
a lowitz arc is an optical phenomenon that occurs in the atmosphere specifically it is a rare type of ice crystal halo that forms a luminous arc which extends inwards from a sun dog parhelion and may continue above or below the sun
lown – ganong – levine syndrome lgl is a pre excitation syndrome of the heart due to abnormal electrical communication between the atria and the ventricles once thought to involve an accessory conduction pathway it is grouped with wolff – parkinson – white syndrome as an atrioventricular re entrant tachycardia avrt individuals with lgl syndrome have a short pr interval with normal qrs complexes and paroxysms of clinically significant tachycardia the syndrome is named after bernard lown william francis ganong jr and samuel a levine individuals with a short pr interval found incidentally on ekg were once thought to have lgl syndrome however subsequent studies have shown that a short pr interval in the absence of symptomatic tachycardia is simply a benign ekg variant
lowry – maclean syndrome is a congenital condition that may be characterized by an ear pit
loxoscelism is a condition occasionally produced by the bite of the recluse spiders genus loxosceles the area becomes dusky and becomes a deep open sore as the skin around the bite dies necrosis it is the only proven type of necrotic arachnidism in humans while there is no known therapy effective for loxoscelism there has been research on antibiotics surgical timing hyperbaric oxygen potential antivenoms and vaccines because of the number of diseases that may mimic loxoscelism it is frequently misdiagnosed by physicians loxoscelism was first described in the united states in 1879 in tennessee although there are up to 13 different loxosceles species in north america 11 native and two nonnative loxosceles reclusa is the species most often involved in serious envenomation loxosceles reclusa has a limited habitat that includes the southeast united states in south america l laeta l intermedia found in brazil and argentina and l gaucho brazil are the three species most often reported to cause necrotic bites
lucey – driscoll syndrome is an autosomal recessive metabolic disorder affecting enzymes involved in bilirubin metabolism it is one of several disorders classified as a transient familial neonatal unconjugated hyperbilirubinemia
lucio s phenomenon is an unusual reaction seen almost exclusively in patients from the caribbean and mexico with diffuse lepromatous leprosy especially in untreated cases it is characterised by recurrent crops of large sharply demarcated ulcerative lesions affecting mainly the lower extremities but may generalise and become fatal as a result of secondary bacterial infection and sepsis lucio s phenomenon was first described by rafael lucio nájera and alvarado as a necrotizing skin reaction associated with non nodular diffuse leprosy in 1852 this reaction was later named by latapi and zamora in 1948 as lucio s phenomenon after identification of histopathological changes involving multiple acute and necrotizing cutaneous vasculitis peculiar to pure and primitive diffuse leprosy ppdl
the lucky jack mine formerly known as the mount emmons molybdenum property is one of the largest molybdenum deposits in the united states the mine is located west of crested butte colorado in gunnison county colorado the molybrook mine has reserves amounting to 220 million tonnes of molybdenum ore grading 0 37 molybdenum thus resulting 814 000 tonnes of molybdenum
ludwig s angina otherwise known as angina ludovici is a serious potentially life threatening cellulitis or connective tissue infection of the floor of the mouth usually occurring in adults with concomitant dental infections and if left untreated may obstruct the airways necessitating tracheostomy it is named after the german physician wilhelm friedrich von ludwig who first described this condition in 1836 other names include angina maligna and morbus strangularis ludwig s angina should not be confused with angina pectoris which is also otherwise commonly known as angina the word angina comes from the greek word ankhon meaning strangling so in this case ludwig s angina refers to the feeling of strangling not the feeling of chest pain though there may be chest pain in ludwig s angina if the infection spreads into the retrosternal space the life threatening nature of this condition generally necessitates surgical management with involvement of critical care physicians such as those found in an intensive care unit
lujan – fryns syndrome lfs also referred to as x linked mental retardation with marfanoid habitus and lujan syndrome is an x linked genetic disorder that causes mild to moderate intellectual disability and features described as marfanoid habitus referring to a group of physical characteristics similar to those found in marfan syndrome these features include a tall thin stature and long slender limbs lfs is also associated with psychopathology and behavioral abnormalities and it exhibits a number of malformations affecting the brain and heart the disorder is inherited in an x linked dominant manner and is attributed to a missense mutation in the med 12 gene there is currently no treatment or therapy for the underlying med 12 malfunction and the exact etiology of the disorder remains unclear
lumbar spinal stenosis lss is a medical condition in which the spinal canal narrows and compresses the spinal cord and nerves at the level of the lumbar vertebra this is usually due to the common occurrence of spinal degeneration that occurs with aging it can also sometimes be caused by spinal disc herniation osteoporosis or a tumor in the cervical neck and lumbar low back region it can be a congenital condition to varying degrees it is also a common symptom for those who suffer from various skeletal dysplasias such as with pseudoachondroplasia and achondroplasia at an early age spinal stenosis may affect the cervical or thoracic region in which case it is known as cervical spinal stenosis or thoracic spinal stenosis in some cases it may be present in all three places in the same patient lumbar spinal stenosis results in low back pain as well as pain or abnormal sensations in the legs thighs feet or buttocks or loss of bladder and bowel control
the lumbocostal triangle or bochdalek s foramen is a defect in the diaphragm normally posterior lateral it is formed by the incomplete closure of the pericardioperitoneal canals by the pleuroperitoneal membrane
in astronomy luminosity is the total amount of energy emitted by a star galaxy or other astronomical object per unit time it is related to the brightness which is the luminosity of an object in a given spectral region in si units luminosity is measured in joules per second or watts values for luminosity are often given in the terms of the luminosity of the sun which has a total power output of 3 846 × 1026 w the symbol for solar luminosity is l ⊙ luminosity can also be given in terms of magnitude the absolute bolometric magnitude mbol of an object is a logarithmic measure of its total energy emission
lumpy skin disease is a disease caused by a virus of the family poxviridae also known as neethling virus it mainly affects cattle and zebus but has also been seen in giraffes african buffalo and impalas lumpy skin disease was first seen as an epidemic in zambia in 1929 and since then has affected cattle throughout africa including the countries south africa egypt and sudan and in 1989 an outbreak was confirmed in israel in april 2016 bulgaria contacted the world food organisation for assistance in dealing with an epidemic it is spread by biting insects lumpy skin disease has an incubation period of two to four weeks symptoms include fever discharge from the eyes and nose nodular necrotic skin lesions edema of the limbs and swollen lymph nodes morbidity can be very high but mortality is low the disease can be easily confused in its early stages with pseudo lumpy skin disease two vaccines are available one a live attenuated version of the neethling virus the other a live attenuated version of the sheeppox virus
the lunar x also known as the werner x is a clair obscur effect in which light and shadow creates the appearance of a letter x on the rim of the blanchinus la caille and purbach craters the x is visible only for a few hours before the first quarter slightly below the lunar terminator near to the x the lunar v is also visible formed by ukert crater and several other small craters
lung abscess is a type of liquefactive necrosis of the lung tissue and formation of cavities more than 2 cm containing necrotic debris or fluid caused by microbial infection this pus filled cavity is often caused by aspiration which may occur during anesthesia sedation or unconsciousness from injury alcoholism is the most common condition predisposing to lung abscesses lung abscess is considered primary 60 when it results from existing lung parenchymal process and is termed secondary when it complicates another process e g vascular emboli or follows rupture of extrapulmonary abscess into lung
lung cancer also known as lung carcinoma is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung if left untreated this growth can spread beyond the lung by the process of metastasis into nearby tissue or other parts of the body most cancers that start in the lung known as primary lung cancers are carcinomas the two main types are small cell lung carcinoma sclc and non small cell lung carcinoma nsclc the most common symptoms are coughing including coughing up blood weight loss shortness of breath and chest pains the vast majority 85 of cases of lung cancer are due to long term tobacco smoking about 10 – 15 of cases occur in people who have never smoked these cases are often caused by a combination of genetic factors and exposure to radon gas asbestos second hand smoke or other forms of air pollution lung cancer may be seen on chest radiographs and computed tomography ct scans the diagnosis is confirmed by biopsy which is usually performed by bronchoscopy or ct guidance prevention is by avoiding risk factors including smoking and air pollution treatment and long term outcomes depend on the type of cancer the stage degree of spread and the person s overall health most cases are not curable common treatments include surgery chemotherapy and radiotherapy nsclc is sometimes treated with surgery whereas sclc usually responds better to chemotherapy and radiotherapy worldwide in 2012 lung cancer occurred in 1 8 million people and resulted in 1 6 million deaths this makes it the most common cause of cancer related death in men and second most common in women after breast cancer the most common age at diagnosis is 70 years overall 17 4 of people in the united states diagnosed with lung cancer survive five years after the diagnosis while outcomes on average are worse in the developing world
lung infarction also known as pulmonary infarction occurs when an artery to the lung becomes blocked and part of the lung dies it is most often caused by pulmonary embolism
lung tumors are neoplastic tumors of the lung these include this list is incomplete you can help by expanding it primary tumors of the lung pulmonary system lung cancer the term commonly used to refer to carcinoma of the lung pulmonary carcinoid tumor pleuropulmonary blastoma neuroendocrine tumors of the lung lymphomas of the lung sarcomas of the lung some rare vascular tumors of the lung non lung tumors which may grow into the lungs mediastinal tumors pleural tumors metastasis or secondary tumors neoplasms with other origin metastasis to the lung
lupoid sycosis is a cutaneous condition that is characterized by a scarring form of deep folliculitis typically affecting the beard area
lupus anticoagulant also known as lupus antibody la lac or lupus inhibitors is an immunoglobulin that binds to phospholipids and proteins associated with the cell membrane lupus anticoagulant is a misnomer as it is actually a prothrombotic agent lupus anticoagulant antibodies in living systems cause an increase in inappropriate blood clotting the name derives from their properties in vitro since in laboratory tests these antibodies increase aptt investigators speculate that the antibodies interfere with phospholipids used to induce in vitro coagulation in vivo the antibodies are thought to interact with platelet membrane phospholipids increasing adhesion and aggregation of platelets which accounts for the in vivo prothrombotic characteristics the condition was first described by hematologist c lockard conley
lupus erythematosus is a name given to a collection of autoimmune diseases in which the human immune system becomes hyperactive and attacks healthy tissues symptoms of these diseases can affect many different body systems including joints skin kidneys blood cells heart and lungs the most common and severe form is systemic lupus erythematosus
lupus erythematosus panniculitis also known as lupus erythematosus profundus lupus panniculitis lupus profundus and subcutaneous lupus erythematosus presents with subcutaneous nodules that are commonly firm sharply defined and nontender
lupus miliaris disseminatus faciei is a disease with a similar appearance to acne vulgaris
lupus nephritis also known as sle nephritis is an inflammation of the kidneys caused by systemic lupus erythematosus sle an autoimmune disease it is a type of glomerulonephritis in which the glomeruli become inflamed as the result of sle the cause of glomerulonephritis is said to be secondary and has a different pattern and outcome from conditions with a primary cause originating in the kidney
lupus pernio is a chronic raised indurated hardened lesion of the skin often purplish in color it is seen on the nose ears cheeks lips and forehead it is pathognomonic of sarcoidosis the name lupus pernio is a misnomer as microscopically this disease shows granulomatous infiltration and does not have features of either lupus or pernio lupus pernio is associated with poor outcomes and lower rate of resolution
lupus vasculitis is a complication of systemic lupus erythematosus in which the autoimmune response causes the deposition of immune complexes such as rheumatoid factor within the blood vessels it may manifest in as high as 56 of lupus patients throughout their life in contrast to antiphospholipid syndrome which has a prevalence of 15 vasculitis more often affects younger men
lupus vulgaris also known as tuberculosis luposa are painful cutaneous tuberculosis skin lesions with nodular appearance most often on the face around the nose eyelids lips cheeks ears and neck it is the most common m tuberculosis skin infection the lesions may ultimately develop into disfiguring skin ulcers if left untreated
in the dungeons dragons fantasy role playing game the lurker is an aberration it is similar to the darkmantle and the piercer but attacks with suffocation instead of impaling the lurker resembles a flat grey stingray with two small eyes at the front they are capable of both creeping along a ceiling and slowly gliding through the air the darkmantle is said to be the result of crossbreeding a lurker with a piercer lurkers live underground
in the mathematical field of real analysis lusin s theorem or luzin s theorem named for nikolai luzin states that every measurable function is a continuous function on nearly all its domain in the informal formulation of j e littlewood every measurable function is nearly continuous
lutembacher s syndrome is a form of congenital heart disease lutembacher s syndrome was first described by a french cardiologist by the name of rene lutembacher 1884 – 1968 of paris france in 1916 lutembacher syndrome is a rare disease that affects one of the chambers of the heart as well as a valve of the heart lutembacher s syndrome is known to affect females more often than males lutembacher is an extremely rare disease lutembacher s can affect children or adults the person can either be born with the disorder or develop it later in life lutembacher affects more specifically the atria of the heart and the mitral or bicuspid valve the disorder itself is known more specifically as both congenital atrial septal defect asd and acquired mitral stenosis ms congenital at birth atrial septal defect refers to a hole being in the septum or wall that separates the two atria this condition is usually seen in fetuses and infants mitral stenosis refers to mitral valve leaflets or valve flaps sticking to each other making the opening for blood to pass from the atrium to the ventricles very small with the valve being so small blood has difficulty passing through the left atrium into the left ventricle there are several types of septal defects that may occur with lutembacher s syndrome asd ostium secundum or asd primium ostium secundum is the most prevalent lutembacher is caused indirectly as the result of heart damage or disorders and not something that is necessarily infectious lutembacher s syndrome is caused by either birth defects where the heart fails to close all holes in the walls between the atria or from an episode of rheumatic fever where damage is done to the heart valves such as the mitral valve and resultant in an opening of heart wall between atria with lutembacher s syndrome a fetus or infant is usually seen to have a hole in their heart wall interatrial separating their right and left atria normally during fetal development blood bypasses the lungs and is oxygenated from the placenta blood passes from the umbilical cord and flows into the left atrium through an opening called the foramen ovale the formaen ovale is a hole between the two atria once a baby is born and the lungs begin to fill with air and the blood flow of the heart changes a tissue flap somewhat like a trap door called the septum primium closes the foramen ovale or hole between the two atria and becomes part of the atrial wall the failure of the hole between the two atria to close after birth leads to a disorder called asd primium the most common problems with an opening found in the heart with lutembacher s syndrome is ostium secundum ostium secundum is a hole that is found within the flap of tissue septum primium that will eventually close the hole between the two atria after birth with either type of asd asd will usually cause the blood flow from the right atrium to skip going to the right ventricle and instead flow to the left atrium if mitral stenosis the hardening of flap of tissue known as a valve which opens and closes between the left atrium and ventricle to control blood flow is also present blood will flow into the right atrium through the hole between the atria wall instead of flowing into the left ventricle and systemic circulation eventually this leads to other problems such as the right ventricle failing and a reduced blood flow to the left ventricle in addition to the asd acquired ms can be present either from an episode of rheumatic fever the mother has or had rheumatic fever during the pregnancy or the child being born with the disorder congenital ms with the combination of both asd and ms the heart can be under severe strain as it tries to move blood throughout the heart and lungs to correct lutembacher s syndrome surgery is often done there are several types of surgeries depending on the cause of lutembacher s syndrome asd primium or asd ostium secundum with mitral stenosis 1 suturing stitching or placing a patch of tissue similar to skin grafting over the hole to completely close the opening 2 reconstructing of the mitral and tricuspid valve while patching any holes in the heart 3 device closure of asd e g amplatzer umbrella or cardioseal to seal the hole 4 percutaneous transcatheter therapy 5 transcatheter therapy of balloon valvuloplasty to correct ms
a luteoma is a tumor that occurs in the ovaries during pregnancy it is associated with an increases of sex hormones primarily progesterone and testosterone the size of the tumor can range from 1 to 25 cm in diameter but is usually 6 to 10 cm in diameter and can grow throughout the duration of the pregnancy however luteomas are benign and resolve themselves after delivery this type of tumor is rare with only about 200 documented cases many of these cases were detected accidentally so the actual rate of occurrence may be higher the most obvious symptom of a luteoma is masculinization of the mother and the possible masculinization of the fetus this occurs because of the release of testosterone by the luteoma testosterone is a sex hormone most abundant in men although small amounts are naturally present in women testosterone is responsible for the male characteristics such as deepening of the voice growth of dark hair and acne while not life threatening the development of male characteristics associated with luteomas can cause visible changes in the mother and can have drastic effects on the formation of the fetus luteomas can cause the fetus to be born with an ambiguous sex necessitating a sex to be chosen for the fetus depending on how the parents want to raise the infant luteomas can be associated with female pseudohermaphroditism
luxating patella or trick knee subluxation of patella floating patella or floating kneecap is a condition in which the patella or kneecap dislocates or moves out of its normal location patellar luxation is a common condition in dogs particularly small and miniature breeds the condition usually becomes evident between the ages of 4 to 6 months it can occur in cats as well especially the domestic shorthair it also occurs in humans where it can be associated with damage to the anterior cruciate ligament
in radiophysics the luxemburg – gorky effect is a phenomenon of cross modulation between two radio waves one of which is strong passing through the same part of a medium especially a conductive region of atmosphere or a plasma
the lycoming io 720 engine is a large displacement horizontally opposed eight cylinder aircraft engine featuring four cylinders per side manufactured by lycoming engines there is no carburetted version of the engine which would have been designated o 720 and therefore the base model is the io 720 the io 720 and the jabiru 5100 are the only flat eight configuration aircraft engines currently in production
lycopenemia is a harmless skin condition caused by excessive ingestion of red foods such as tomatoes beets chili beans and various fruits and berries which leads to a reddish discoloration of the skin
lycoperdonosis is a respiratory disease caused by the inhalation of large amounts of spores from mature puffballs it is classified as a hypersensitivity pneumonitis also called extrinsic allergic alveolitis — an inflammation of the alveoli within the lung caused by hypersensitivity to inhaled natural dusts it is one of several types of hypersensitivity pneumonitis caused by different agents that have similar clinical features typical progression of the disease includes symptoms of a cold hours after spore inhalation followed by nausea rapid pulse crepitant rales a sound like that made by rubbing hairs between the fingers heard at the end of inhalation and dyspnea chest radiographs reveal the presence of nodules in the lungs the early symptoms presented in combination with pulmonary abnormalities apparent on chest radiographs may lead to misdiagnosis of the disease as tuberculosis histiocytosis or pneumonia caused by pneumocystis carinii lycoperdonosis is generally treated with corticosteroids which decrease the inflammatory response these are sometimes given in conjunction with antimicrobials the disease was first described in the medical literature in 1967 by r d strand and colleagues in the new england journal of medicine in 1976 a 4 year old was reported developing the disease in norway after purposely inhaling a large quantity of lycoperdon spores to stop a nosebleed lycoperdon species are sometimes used in folk medicine in the belief that their spores have haemostatic properties a 1997 case report discussed several instances of teenagers inhaling the spores in one severe case the individual inhaled enough spores so as to be able to blow them out of his mouth he underwent bronchoscopy and then had to be on life support before recovering in about four weeks in another instance a teenager spent 18 days in a coma had portions of his lung removed and suffered severe liver damage in wisconsin eight teenagers who inhaled spores at a party presented clinical symptoms such as cough fever shortness of breath myalgia and fatigue within a week five of the eight required hospitalization of these two required intubation to assist in breathing the disease is rare possibly because of the large quantity of spores that need to be inhaled for clinical effects to occur lycoperdonosis also occurs in dogs in the few reported cases the animals had been playing or digging in areas known to contain puffballs known species of puffballs implicated in the etiology of the published cases include the widespread lycoperdon perlatum the devil s snuff box l gemmatum and calvatia gigantea both of the lycoperdaceae family
the modern lydian musical scale is a rising pattern of pitches comprising three whole tones a semitone two more whole tones and a final semitone this sequence of pitches roughly describes the fifth of the eight gregorian church modes known as mode v or the authentic mode on f theoretically using b ♮ but in practice more commonly featuring b ♭ because of the importance of the major scale in modern music the lydian mode is often described or learned as the scale that begins on the fourth scale degree of the major scale or alternatively as the major scale with the fourth scale degree raised half a step
lying in repose or public viewing ae is the condition of a deceased person often of high social stature whose body is available for public viewing lying in repose differs from the more formal honor of lying in state which is generally held at the principal government building of the deceased person s country and often accompanied by an honor guard or guard of honour
lymantria dispar multicapsid nuclear polyhedrosis virus or ldmnpv is a well known and spectacular viral infection of gypsy moths lymantria dispar which causes infected larvae to die and disintegrate infected larvae climb to the top of the tree during the day and die the larvae then melt or disintegrate falling on the foliage below where they infect more larvae while it possesses many common and technical names it is often referred to as gypchek gypchek is an insecticide which uses the virus to control the gypsy moth population because the virus only infects lymantria dispar it has proven safe for use with other insects including ants bees and non target lepidopteran species studies into its safety have found no toxicity or mortality concerns except for some irritation resulting from ocular doses administered to rabbits the gene responsible for the behavior of infected larvae has been found to be egt codes ecdysteroid udp glucosyltransferase with protein tyrosine phosphatase ptp playing a role in the infection of brain tissue due to the virus s effect on the infected larvae various reports of zombie caterpillars popularized the virus at the time of the discovery of the egt gene
lyme disease also known as lyme borreliosis is an infectious disease caused by bacteria of the borrelia type the most common sign of infection is an expanding area of redness known as erythema migrans that begins at the site of a tick bite about a week after it has occurred the rash is typically neither itchy nor painful approximately 25 – 50 of infected people do not develop a rash other early symptoms may include fever headache and feeling tired if untreated symptoms may include loss of the ability to move one or both sides of the face joint pains severe headaches with neck stiffness or heart palpitations among others months to years later repeated episodes of joint pain and swelling may occur occasionally people develop shooting pains or tingling in their arms and legs despite appropriate treatment about 10 to 20 of people develop joint pains memory problems and feel tired for at least six months lyme disease is transmitted to humans by the bite of infected ticks of the ixodes genus usually the tick must be attached for 36 to 48 hours before the bacteria can spread in north america borrelia burgdorferi sensu stricto and borrelia mayonii are the cause in europe and asia the bacteria borrelia afzelii and borrelia garinii are also causes of the disease the disease does not appear to be transmissible between people by other animals or through food diagnosis is based upon a combination of symptoms history of tick exposure and possibly testing for specific antibodies in the blood blood tests are often negative in the early stages of the disease testing of individual ticks is not typically useful prevention includes efforts to prevent tick bites such as by wearing long pants and using deet using pesticides to reduce tick numbers may also be effective ticks can be removed using tweezers if the removed tick was full of blood a single dose of doxycycline may be used to prevent development of infection but is not generally recommended since development of infection is rare if an infection develops a number of antibiotics are effective including doxycycline amoxicillin and cefuroxime treatment is usually for two or three weeks some people develop a fever and muscle and joint pains from treatment which may last for one or two days in those who develop persistent symptoms long term antibiotic therapy has not been found to be useful lyme disease is the most common disease spread by ticks in the northern hemisphere it is estimated to affect 300 000 people a year in the united states and 65 000 people a year in europe infections are most common in the spring and early summer lyme disease was diagnosed as a separate condition for the first time in 1975 in old lyme connecticut it was originally mistaken for juvenile rheumatoid arthritis the bacterium involved was first described in 1981 by willy burgdorfer chronic symptoms are well described and are known as post treatment lyme disease syndrome although it is often called chronic lyme disease some healthcare providers claim that it is due to ongoing infection however this is not believed to be true a previous vaccine is no longer available research is ongoing to develop new vaccines
chronic lyme disease is a controversial diagnosis that encompasses a broad array of illnesses or symptom complexes for which there is no reproducible or convincing scientific evidence of any relationship to b burgdorferi infection there is no clinical evidence that chronic lyme disease is caused by a persistent infection most medical authorities advise against long term antibiotic treatment for lyme disease though they agree that some patients do experience lingering symptoms
lymphangiectasia is a pathologic dilation of lymph vessels when it occurs in the intestines of dogs and more rarely humans it causes a disease known as intestinal lymphangiectasia this disease is characterized by lymphatic vessel dilation chronic diarrhea and loss of proteins such as serum albumin and globulin it is considered to be a chronic form of protein losing enteropathy it is also known as lymphangiectasis
lymphangioleiomyomatosis lam is a rare progressive and systemic disease that typically results in cystic lung destruction and predominantly affects women especially during childbearing years it occurs in more than 30 of women with tuberous sclerosis complex tsc lam a heritable syndrome that is associated with seizures cognitive impairment and benign tumors in multiple tissues most lam patients who present for medical evaluation have the sporadic form of the disease s lam however which is not associated with other manifestations of tuberous sclerosis complex mild cystic changes consistent with lam have been described in 10 – 15 of men with tsc but symptomatic lam in males is extremely rare sporadic lam occurs exclusively in women with one published exception to date both tsc lam and s lam are associated with mutations in tuberous sclerosis genes lung destruction in lam is a consequence of diffuse infiltration by neoplastic smooth muscle like cells which invade all lung structures including the lymphatics airway walls blood vessels and interstitial spaces the consequences of obstruction of the vessels and airways include chylous fluid accumulations hemoptysis airflow obstruction and pneumothorax the typical disease course is characterized by progressive dyspnea on exertion punctuated by recurrent pneumothoraces and in some patients chylous pleural effusions or ascites estimates of median survival vary from 10 to 30 years based on whether hospital based or population based cohorts are studied most patients have dyspnea on exertion with daily activities by 10 years after symptom onset and many will require supplemental oxygen over that interval an fda approved drug for treatment of lam sirolimus is now available for stabilization of lung function decline lung transplant remains the option of last resort for patients with advanced disease
lymphangiomas are malformations of the lymphatic system characterized by lesions that are thin walled cysts these cysts can be macroscopic as in a cystic hygroma or microscopic the lymphatic system is the network of vessels responsible for returning to the venous system excess fluid from tissues as well as the lymph nodes that filter this fluid for signs of pathogens these malformations can occur at any age and may involve any part of the body but 90 occur in children less than 2 years of age and involve the head and neck these malformations are either congenital or acquired congenital lymphangiomas are often associated with chromosomal abnormalities such as turner syndrome although they can also exist in isolation lymphangiomas are commonly diagnosed before birth using fetal ultrasonography acquired lymphangiomas may result from trauma inflammation or lymphatic obstruction most lymphangiomas are benign lesions that result only in a soft slow growing doughy mass since they have no chance of becoming malignant lymphangiomas are usually treated for cosmetic reasons only rarely impingement upon critical organs may result in complications such as respiratory distress when a lymphangioma compresses the airway treatment includes aspiration surgical excision laser and radiofrequency ablation and sclerotherapy
superficial lymphatic malformation also known as lymphangioma circumscriptum is a congenital malformation of the superficial lymphatics presenting as groups of deep seated vesicle like papules resembling frog spawn at birth or shortly thereafter
lymphangiosarcoma is a rare malignant tumor which occurs in long standing cases of primary or secondary lymphedema it involves either the upper or lower lymphedematous extremities but is most common in upper extremities although its name implies lymphatic origin it is believed to arise from endothelial cells and may be more accurately referred to as angiosarcoma
lymphangiosclerosis is a hardened lymph vessel although it can feel like a hardened almost calcified or fibrous vein it tends to not share the common blue tint with a vein however it can be felt as a hardened lump or vein even when the penis is flaccid and is even more prominent during an erection it is considered a benign physical condition although it can become uncomfortable during sex or masturbation it is fairly common and can follow a particularly vigorous sexual activity for men and tends to go away if given rest and more gentle care for example by use of lubricants even without rest or gentle care in some cases it will simply disappear after a few weeks on its own
lymphangitis is an inflammation or an infection of the lymphatic channels that occurs as a result of infection at a site distal to the channel the most common cause of lymphangitis in humans is streptococcus pyogenes group a strep although it can also be caused by the fungus sporothrix schenckii lymphangitis is sometimes mistakenly called blood poisoning in reality blood poisoning is synonymous with sepsis signs and symptoms include a deep reddening of the skin warmth lymphadenitis inflammation of a lymphatic gland and a raised border around the affected area the person may also have chills and a high fever along with moderate pain and swelling a person with lymphangitis should be hospitalized and closely monitored by medical professionals lymphangitis is the inflammation of the lymphatic vessels and channels this is characterized by certain inflammatory conditions of the skin caused by bacterial infections thin red lines may be observed running along the course of the lymphatic vessels in the affected area accompanied by painful enlargement of the nearby lymph nodes when the inferior limbs are affected the redness of the skin runs over the great saphenous vein location and confusion can be made with a thrombophlebitis chronic lymphangitis is a cutaneous condition that is the result of recurrent bouts of acute bacterial lymphangitis
lymphangitis carcinomatosa is inflammation of the lymph vessels lymphangitis caused by a malignancy breast lung stomach pancreas and prostate cancers are the most common tumors that result in lymphangitis lymphangistis carcinomatosa may be caused by the following malignancies as suggested by the mnemonic certain cancers spread by plugging the lymphatics c cervical cancer cancer colon cancer spread stomach cancer by breast cancer bronchiogenic carcinoma plugging pancreas the thyroid lymphatics larynx lymphangitis carcinomatosa was first described by pathologist gabriel andral in 1829 in a patient with uterine cancer lymphangitis carcinomatosa may show the presence of kerley b lines on chest xray lymphangitis carcinomatosis most often affects people 40 – 49 years of age
lymphatic disease is a class of disorders which directly affect the components of the lymphatic system examples include castleman s disease and lymphedema diseases and disorderhodgkin s disease hodgkin s lymphoma this is a type of cancer of the lymphatic system it can start almost anywhere in the body it is believed to be caused by hiv epstein barr syndrome age and family history symptoms include weight loss fever swollen lymph nodes night sweats itchy skin fatigue chest pain coughing or trouble swallowing non hodgkin s lymphoma lymphoma is a usually malignant cancer it is caused by the body producing too many abnormal white blood cells it is not the same as hodgkin s disease symptoms usually include painless enlarged lymph node or nodes in the neck weakness fever weight loss and anemia lymphadenitis is an infection of the lymph nodes usually caused by a virus bacteria or fungi symptoms include redness or swelling around the lymph node lymphangitis lymphangitis is an inflammation of the lymph vessels symptoms usually include swelling redness warmth pain or red streaking around the affected area lymphedema lymphedema is the chronic pooling of lymph fluid in the tissue it usually starts in the feet or lower legs it s also a side effect of some surgical procedures lymphocytosis lymphocytosis is a high lymphocyte count it can be caused by an infection blood cancer lymphoma or autoimmune disorders that are accompanied by chronic swelling
lymphatic filariasis also known as elephantiasis is a human disease caused by parasitic worms known as filarial worms most cases of the disease have no symptoms some people however develop a syndrome called elephantiasis which is marked by severe swelling in the arms legs or genitals the skin may also become thicker and pain may occur the changes to the body can cause social and economic problems for the affected person the worms are spread by the bites of infected mosquitoes three types of worms are known to cause the disease wuchereria bancrofti brugia malayi and brugia timori with wuchereria bancrofti being the most common these worms damage the lymphatic system the disease is diagnosed by microscopic examination of blood collected during the night the blood is typically examined as a smear after being stained with giemsa stain testing the blood for antibodies against the disease may also permit diagnosis other roundworms from the same family are responsible for river blindness prevention can be achieved by treating entire groups in which the disease exists known as mass deworming this is done every year for about six years in an effort to rid a population of the disease entirely medications used include antiparasitics such as albendazole with ivermectin or albendazole with diethylcarbamazine the medications do not kill the adult worms but prevent further spread of the disease until the worms die on their own efforts to prevent mosquito bites are also recommended including reducing the number of mosquitoes and promoting the use of bed nets lymphatic filariasis is one of the main neglected tropical diseases and one of the four main worm infections more than 120 million people are infected with lymphatic filariasis and about 1 4 billion people are at risk of the disease in 73 countries it is most common in tropical africa and asia the disease results in economic losses of many billions of dollars a year
lymphedema is a condition of localized fluid retention and tissue swelling caused by a compromised lymphatic system which normally returns interstitial fluid to the thoracic duct then the bloodstream the condition can be inherited or can be caused by a birth defect though it is frequently caused by cancer treatments and by parasitic infections though incurable and progressive a number of treatments can ameliorate symptoms tissues with lymphedema are at high risk of infection
lymphedema praecox is a condition characterized by swelling of the soft tissues in which an excessive amount of lymph has accumulated and generally develops in females between the ages of nine and twenty five this is the most common form of primary lymphedema accounting for about 80 of the patients
lymphedema – distichiasis syndrome is a medical condition associated with the foxc 2 gene
a lymphocele is a collection of lymphatic fluid within the body not bordered by epithelial lining it is usually a surgical complication seen after extensive pelvic surgery such as cancer surgery and is most commonly found in the retroperitoneal space spontaneous development is rare
lymphocystis is a common viral disease of freshwater and saltwater fish the viruses that cause this disease belong to the genus lymphocystivirus of the family iridoviridae aquarists often come across this virus when their fish are stressed such as when put into a new environment and the virus is able to grow the fish starts growing small white pin prick like growths on their fins or skin and this is often mistaken for ich ick ichthyophthirius multifiliis in the early stages it soon clumps together to form a cauliflower like growth on the skin mouth fins and occasional gills lesions at the base of the dorsal fin are common among freshwater species of central american origin most notably herichthys carpentis inside the mouth of herichthys cyanoguttatus geophagus steindachneri on the tail fin of koi carps us native sunfish lepomis sp on the side flanks of walleye sauger flounder on random head and or tail areas of common goldfish and oranda variants this virus appears to present itself as a lesion s at differing locations depending on the species of fish being attacked often complicating initial diagnosis lymphocystis does show some host specificity i e each strain or species of lymphocystis can infect only its primary host fish or some additional closely related fish there is no known cure for this virus though a privately owned fish research breeding facility near gainesville florida usa has reportedly been able to suppress the virus into remission using the human antiviral acyclovir at the rate of 200 mg per 10 us gallons for 2 days otherwise some aquarists recommend surgery to remove the affected area if it is very serious followed by an antibiotic bath treatment to prevent a secondary bacterial infection of the open wounds eventually the growths inhibit the fish s ability to swim breathe or eat and secondary bacterial infections usually kills the fish usually the best cure is to simply give the fish a stress free life a weekly bacteria treatment and the virus will slowly subside and the fins will repair themselves this can take many months like most viral infections even in humans the first outbreaks are the most serious whilst the immune system learns how to suppress it the outbreaks become less severe over time assuming the organism survives the initial outbreaks
a lymphocyte is one of the subtypes of white blood cell in a vertebrate s immune system lymphocytes include natural killer cells nk cells which function in cell mediated cytotoxic innate immunity t cells for cell mediated cytotoxic adaptive immunity and b cells for humoral antibody driven adaptive immunity they are the main type of cell found in lymph which prompted the name lymphocyte
lymphocytic choriomeningitis lcm is a rodent borne viral infectious disease that presents as aseptic meningitis encephalitis or meningoencephalitis its causative agent is the lymphocytic choriomeningitis virus lcmv a member of the family arenaviridae the name was coined by charles armstrong in 1934
lymphocytic colitis is a subtype of microscopic colitis a condition characterized by chronic non bloody watery diarrhea the colonoscopy is normal but histology of the mucosal biopsy reveals an accumulation of lymphocytes in the colonic epithelium and connective tissue lamina propria collagenous colitis shares this feature but additionally shows a distinctive thickening of the subepithelial collagen table the peak incidence of lymphocytic colitis is in persons over age 50 the disease affects women and men equally lymphocytic colitis was first described in 1989
lymphocytic interstitial pneumonia also called lymphocytic interstitial pneumonitis or lip is a syndrome secondary to autoimmune and other lymphoproliferative disorders symptoms include fever cough and shortness of breath lymphocytic interstitial pneumonia applies to disorders associated with both monoclonal or polyclonal gammopathy
lymphocytic pleocytosis is an abnormal increase in the amount of lymphocytes in the cerebrospinal fluid csf it is usually considered to be a sign of infection or inflammation within the nervous system and is encountered in a number of neurological diseases such as pseudomigraine susac s syndrome and encephalitis while lymphocytes make up roughly a quarter of all white blood cells wbc in the body they are generally rare in the csf under normal conditions there are usually less than 5 white blood cells per µl of csf in a pleocytic setting the number of lymphocytes can jump to more than 1 000 cells per mm 3 increases in lymphocyte count are often accompanied by an increase in cerebrospinal protein concentrations in addition to pleocytosis of other types of white blood cells
lymphocytopenia or lymphopenia is the condition of having an abnormally low level of lymphocytes in the blood lymphocytes are a white blood cell with important functions in the immune system the opposite is lymphocytosis which refers to an excessive level of lymphocytes lymphocytopenia may be present as part of a pancytopenia when the total numbers of all types of blood cells are reduced
lymphocytosis is an increase in the number of lymphocytes in the blood in adults lymphocytosis is present when the lymphocyte count is greater than 4000 per microliter 4 0 x 10 9 l in older children greater than 7000 per microliter and in infants greater than 9000 per microliter lymphocytes normally represent 20 to 40 of circulating white blood cells lymphocytosis is usually detected when a complete blood count is obtained if not provided the lymphocyte count can be calculated by multiplying the total white blood cell wbc count by the percentage of lymphocytes found in the differential count the lymphocyte count can also be directly measured by flow cytometry
for more information on this topic see nasopharyngeal carcinoma lymphoepithelioma is a type of poorly differentiated nasopharyngeal carcinoma characterized by prominent infiltration of lymphocytes in the area involved by tumor lymphoepithelioma is also known as class iii nasopharyngeal carcinoma in the who classification system it has a high tendency to metastasize and is responsive to radiotherapy most cases are associated with epstein barr virus infection lymphoepithelioma may also be referred to as schmincke regaud tumor after the german pathologist alexander schminke and french radiologist claude regaud lymphoepithelioma like carcinomas are carcinomas that arise outside of the nasopharynx but resemble a lymphoepithelioma histologically lymphoepithelioma like carcinomas may be found in almost any epithelial organ including the lung thymus breast colon endometrium prostate and skin as well as urinary bladder trachea esophagus stomach salivary glands vulva
lymphoepithelioma like carcinoma lelc is a medical term referring to a histological variant of malignant tumor arising from the uncontrolled mitosis of transformed cells originating in epithelial tissue or in cells that display epithelial characteristics that bear microscopic resemblance to lymphoepithelioma nasopharyngeal carcinoma there is considerable variation in the classification of lelc — while it is perhaps most commonly considered a subtype of squamous cell carcinoma it can also be classified as a form of large cell carcinoma i e when occurring in the lung and can be considered as a separate unique entity in most anatomical sites many cases are associated with the epstein barr virus in the breast the macroscopic microscopic epidemiologic and prognostic features of lelc are very similar to medullary carcinoma ebv status is one differentiator
lymphogranuloma venereum lgv also known as climatic bubo durand – nicolas – favre disease poradenitis inguinale and strumous bubo is a sexually transmitted disease caused by the invasive serovars l 1 l 2 l 2 a or l 3 of chlamydia trachomatis lgv is primarily an infection of lymphatics and lymph nodes chlamydia trachomatis is the bacterium responsible for lgv it gains entrance through breaks in the skin or it can cross the epithelial cell layer of mucous membranes the organism travels from the site of inoculation down the lymphatic channels to multiply within mononuclear phagocytes of the lymph nodes it passes in developed nations it was considered rare before 2003 however a recent outbreak in the netherlands among gay men has led to an increase of lgv in europe and the united states a majority of these patients are hiv co infected lgv was first described by wallace in 1833 and again by durand nicolas and favre in 1913 since the 2004 dutch outbreak many additional cases have been reported leading to greater surveillance soon after the initial dutch report national and international health authorities launched warning initiatives and multiple lgv cases were identified in several more european countries belgium france the uk germany sweden italy and switzerland and the us and canada all cases reported in amsterdam and france and a considerable percentage of lgv infections in the uk and germany were caused by a newly discovered chlamydia variant l 2 b a k a the amsterdam variant the l 2 b variant could be traced back and was isolated from anal swabs of men who have sex with men msm who visited the sti city clinic of san francisco in 1981 this finding suggests that the recent lgv outbreak among msm in industrialised countries is a slowly evolving epidemic the l 2 b serovar has also been identified in australia
lymphohemangioma or lymphohaemangioma from latin lympha meaning water greek αίμα haema meaning blood αγγείο angeio meaning vessel and – ωμα – oma meaning tumor is a disease characterized by swelling of the lymph nodes and blood vessels it is variously described as a mixture of clear fluid and blood filled cysts a mass of abnormal swollen veins and lymph nodes or a tumorous growth of lymph and blood vessels it is also sometimes described as a misnomer for combined lymphatic and capillary malformation lymphohemangioma commonly appears in and around the eyes and mouth but may also occur in other areas including the pelvis urethra bladder and in the limbs amputation of extremities may be necessary if the disease renders the extremity non functional
lymphoid leukosis is a disease that affects chickens caused by the retrovirus avian leukosis virus it is a neoplastic disease caused by a virus of the leucosis which may take the form of a tumor of the bursa of fabricius and metastasis to other tissues of the chicken and cause enlargement and swelling of the abdomen
lymphoid hyperplasia is the rapid growth proliferation of normal cells that resemble lymph tissue
lymphoid leukemias — also called lymphocytic lymphogenous or lymphoblastic leukemias — are a group of leukemias affecting circulating lymphocytes a type of white blood cells the lymphocytic leukemias are closely related to lymphomas of the lymphocytes to the point that some of them are unitary disease entities that can be called by either name for example adult t cell leukemia lymphoma such diseases are all lymphoproliferative disorders most lymphoid leukemias involve a particular subtype of lymphocytes the b cells
lymphoma is a group of blood cell tumors that develop from lymphocytes a type of white blood cell the name often refers to just the cancerous ones rather than all such tumors signs and symptoms may include enlarged lymph nodes fever drenching sweats unintended weight loss itching and feeling tired the enlarged lymph nodes are usually painless the sweats are most common at night there are dozens of subtypes of lymphomas the two main categories of lymphomas are hodgkin s lymphomas hl and the non hodgkin lymphomas nhl the world health organization who includes two other categories as types of lymphoma multiple myeloma and immunoproliferative diseases about 90 of lymphomas are non hodgkin lymphomas lymphomas and leukemias are a part of the broader group of tumors of the hematopoietic and lymphoid tissues risk factors for hodgkin lymphoma include infection with epstein – barr virus and a history of the disease in the family risk factors for common types of non hodgkin lymphomas include autoimmune diseases hiv aids infection with human t lymphotropic virus immunosuppressant medications and some pesticides eating large amounts of red meat may also increase the risk diagnosis if enlarged lymph nodes are present is usually by lymph node biopsy blood urine and bone marrow testing may also be useful in the diagnosis medical imaging may then be done to determine if and where the cancer has spread lymphoma most often spreads to the lungs liver and or brain treatment may involve one or more of the following chemotherapy radiation therapy targeted therapy and surgery in some non hodgkin lymphomas an increased amount of protein produced by the lymphoma cells causes the blood to become so thick that plasmapheresis is performed to remove the protein watchful waiting may be appropriate for certain types the outcome depends on the subtype with some being curable and treatment prolonging survival in most the five year survival rate in the united states for all hodgkin lymphoma subtypes is 85 while that for non hodgkin lymphomas is 69 worldwide lymphomas developed in 566 000 people in 2012 and caused 305 000 deaths they make up 3 – 4 of all cancers making them as a group the seventh most common form in children they are the third most common cancer they occur more often in the developed world than the developing world
lymphoma cutis is a cutaneous condition characterized by a proliferation of lymphoid tissue
lymphoma lymposarcoma in animals is a type of cancer defined by a proliferation of malignant lymphocytes within solid organs such as the lymph nodes bone marrow liver and spleen the disease also may occur in the eye skin and gastrointestinal tract
lymphomatoid granulomatosis lyg or lg is a very rare lymphoproliferative disorder first characterized in 1972 with lymphomatoid meaning lymphoma like and granulomatosis denoting one of its microscopic characteristics polymorphic lymphoid infiltrates and focal necrosis within it while most commonly found in middle age patients it has been observed in young people with a study identifying 47 cases of patients aged 0 – 18 years in the literature males are found to be affected twice as often as females
lymphomatoid papulosis lyp is a rare skin disorder the overall prevalence rate of lymphomatoid papulosis is estimated at 1 2 to 1 9 cases per 1 000 000 population this rare condition has only been studied in depth since 1968
lymphoproliferative disorders lpds refer to several conditions in which lymphocytes are produced in excessive quantities they typically occur in people who have a compromised immune system they are sometimes equated with immunoproliferative disorders but technically lymphoproliferative disorders are a subset of immunoproliferative disorders along with hypergammaglobulinemia and paraproteinemias
lyngstadaas syndrome also known as severe dental aberrations in familial steroid dehydrogenase deficiency is a rare autosomal recessive liver disease involving an enzyme steroid dehydrogenase deficiency and dental anomalies the disease is named after professor ståle petter lyngstadaas
lysinuric protein intolerance lpi also called hyperdibasic aminoaciduria type 2 cationic aminoaciduria or familial protein intolerance is an autosomal recessive metabolic disorder affecting amino acid transport about 140 patients have been reported almost half of them of finnish origin individuals from japan italy morocco and north africa have also been reported
lysosomal acid lipase deficiency or lal deficiency or lal d happens when the body does not produce enough active lysosomal acid lipase lal enzyme this enzyme plays an important role in breaking down fatty material cholesteryl esters and triglycerides in the body infants children and adults that suffer from lal deficiency experience a range of serious health problems the lack of the lal enzyme can lead to a build up of fatty material in a number of body organs including the liver spleen gut in the wall of blood vessels and other important organs very low levels of the lal enzyme lead to lal deficiency historically called wolman disease after the physician who first described it lal deficiency typically affects infants in the first year of life the accumulation of fat in the walls of the gut in early onset disease leads to serious digestive problems including malabsorption a condition in which the gut fails to absorb nutrients and calories from food because of these digestive complications affected infants usually fail to grow and gain weight at the expected rate for their age failure to thrive as the disease progresses it can cause life threatening liver dysfunction or liver failure until 2015 there was no treatment and very few infants with lal d survived beyond the first year of life in 2015 an enzyme replacement therapy sebelipase alfa was approved in the us and eu the therapy was additionally approved in japan in 2016
lysosomal storage diseases lsds ˌlaɪsəˈsoʊməl are a group of approximately 50 rare inherited metabolic disorders that result from defects in lysosomal function lysosomes are sacs of enzymes within cells that digest large molecules and pass the fragments on to other parts of the cell for recycling this process requires several critical enzymes if one of these enzymes is defective because of a mutation the large molecules accumulate within the cell eventually killing it lysosomal storage disorders are caused by lysosomal dysfunction usually as a consequence of deficiency of a single enzyme required for the metabolism of lipids glycoproteins sugar containing proteins or so called mucopolysaccharides individually lsds occur with incidences of less than 1 100 000 however as a group the incidence is about 1 5 000 1 10 000 most of these disorders are autosomal recessively inherited such as niemann pick disease type c however a few are x linked recessively inherited such as fabry disease and hunter syndrome mps ii the lysosome is commonly referred to as the cell ’ s recycling center because it processes unwanted material into substances that the cell can utilize lysosomes break down this unwanted matter via enzymes highly specialized proteins essential for survival lysosomal disorders are usually triggered when a particular enzyme exists in too small an amount or is missing altogether when this happens substances accumulate in the cell in other words when the lysosome does not function normally excess products destined for breakdown and recycling are stored in the cell like other genetic diseases individuals inherit lysosomal storage diseases from their parents although each disorder results from different gene mutations that translate into a deficiency in enzyme activity they all share a common biochemical characteristic – all lysosomal disorders originate from an abnormal accumulation of substances inside the lysosome lysosomal storage diseases affect mostly children and they often die at a young and unpredictable age many within a few months or years of birth many other children die of this disease following years of suffering from various symptoms of their particular disorder
lytico bodig sometimes spelled lytigo bodig is the name of a disease in the language of chamorro it is referred to by neuroscientists as amyotrophic lateral sclerosis parkinsonism dementia als pdc a term coined by asao hirano and colleagues in 1961 it is a neurodegenerative disease of uncertain etiology that exists in the united states territory of guam the disease resembles amyotrophic lateral sclerosis als parkinson s disease and alzheimer s first reports of the disease surfaced in three death certificates on guam in 1904 these death certificates made some mention of paralysis the frequency of cases grew amongst the chamorro people on guam until it was the leading cause of adult death between 1945 and 1956 the incidence rate was 200 per 100 000 per year and it was 100 times more prevalent than in the rest of the world neurologist oliver sacks detailed this disease in his book the island of the colorblind sacks and paul alan cox subsequently wrote that a local species of flying fox which is now extinct due to overhunting had been feeding on cycads and concentrating β methylamino l alanine bmaa a known neurotoxin in its body fat the hypothesis suggests that consumption of the fruit bat by the chamorro exposed them to bmaa contributing to or causing their condition decline in consumption of the bats has been linked to a decline in the incidence of the disease
lábrea fever also known as lábrea s black fever and lábrea hepatitis is a lethal tropical viral infection discovered in the 1950 s in the city of lábrea in the brazilian amazon basin where it occurs mostly in the area south of the amazon river in the states of acre amazonas and rondônia the disease has also been diagnosed in colombia and peru the similar form in colombia has been named santa marta fever its main manifestation is a fulminant hepatitis which may kill in less than a week and which characteristically affects children and young adults and more males than females it is accompanied also by an encephalitis in many cases the disease is highly lethal in a study carried out in 1986 at boca do acre also in the amazon 39 patients out of 44 died in the acute phase of the disease survivors may develop chronic disease
léri – weill dyschondrosteosis or lwd is a rare pseudoautosomal dominant genetic disorder which results in dwarfism with short forearms and legs mesomelic dwarfism and a bayonet like deformity of the forearms madelung s deformity
löffler s syndrome or loeffler s syndrome is a disease in which eosinophils accumulate in the lung in response to a parasitic infection it was first described in 1932 by wilhelm löffler in cases of eosinophilic pneumonia caused by the parasites ascaris lumbricoides strongyloides stercoralis and the hookworms ancylostoma duodenale and necator americanus although löffler only described eosinophilic pneumonia in the context of infection many authors give the term löffler s syndrome to any form of acute onset pulmonary eosinophilia no matter what the underlying cause if the cause is unknown it is specified and called simple pulmonary eosinophilia cardiac damage caused by the damaging effects of eosinophil granule proteins ex major basic protein is known as loeffler endocarditis and can be caused by idiopathic eosinophilia or eosinophilia in response to parasitic infection
löfgren syndrome is a type of acute sarcoidosis that is frequent in scandinavian irish african and puerto rican women it was described in 1953 by sven halvar löfgren a swedish clinician some have considered the condition to be imprecisely defined
the m naghten rule pronounced and sometimes spelled mcnaughton is any variant of the 1840 s jury instruction in a criminal case when there is a defense of insanity that every man is to be presumed to be sane and that to establish a defense on the ground of insanity it must be clearly proved that at the time of the committing of the act the party accused was laboring under such a defect of reason from disease of the mind as not to know the nature and quality of the act he was doing or if he did know it that he did not know he was doing what was wrong it emphasizes cognition knowledge as compared to the american law institute model penal code test ali test which broadened knowledge to include capacity to appreciate the criminality of conduct and a volitional element as to capacity to conform to the law in the 1960 s the ali test mostly replaced the m naughten rule in america until the 1980 s when in the aftermath of john hinckley shooting president ronald reagan many ali states returned to a variation of m naughten the rule was formulated as a reaction to the acquittal in 1843 of daniel m naghten on the charge of murdering edward drummond whom m naghten had mistaken for british prime minister robert peel m naghten fired a pistol at the back of peel s secretary edward drummond who died five days later the house of lords asked a panel of judges presided over by sir nicolas conyngham tindal chief justice of the common pleas a series of hypothetical questions about the defence of insanity the principles expounded by this panel have come to be known as the m naghten rules though they have gained any status only by usage in the common law and m naghten himself would have been found guilty if they had been applied at his trial the rules so formulated as m naghten s case 1843 10 c f 200 have been a standard test for criminal liability in relation to mentally disordered defendants in common law jurisdictions ever since with some minor adjustments when the tests set out by the rules are satisfied the accused may be adjudged not guilty by reason of insanity or guilty but insane and the sentence may be a mandatory or discretionary but usually indeterminate period of treatment in a secure hospital facility or otherwise at the discretion of the court depending on the country and the offence charged instead of a punitive disposal the insanity defence is recognized in australia canada england and wales hong kong india the republic of ireland new zealand norway and most u s states with the exception of idaho kansas montana utah and vermont not all of these jurisdictions still use the m naghten rules
in the mathematical subfield of numerical analysis an m spline is a non negative spline function
the m 74 syndrome is a reproduction disorder of salmon salmo salar feeding in the baltic sea m 74 manifests as offspring mortality during the yolk sac fry phase before dying the yolk sac fry display typical symptoms thiamine vitamin b 1 deficiency in eggs is the immediate cause of m 74 mortality the deficiency can be prevented by thiamine treatments for the first time bulgarian research team opines that with m 74 syndrome are affected also male gametes and worsened parameters of the spermograme the use of bulgarian semen protective media 49282 49283 и 49397 for trout sperm fertility improving was proposed the thiamine deficiency syndrome m 74 is related to the fat and thiamine content of prey fish the diet of baltic salmon leads to thiamine deficiency in eggs and consequently to the mortality of yolk sac fry the main prey species of the baltic salmon are sprat sprattus sprattus and herring clupea harangus membras average fat content is greater in sprat than in herring the fat content is highest and the thiamine concentration is lowest in the youngest sprat the need for thiamine depends on the amount of fat in the diet thiamine deficiency in eggs results from an unbalanced diet abundant in fatty prey fish such as young sprat from which the supply of thiamine is insufficient in proportion to the supply of energy and unsaturated fatty acids for salmon relationships between fish stock changes in the baltic sea and the m 74 syndrome the m 74 syndrome is connected to a weak atlantic cod gadus morhua stock and strong year classes of sprat in the baltic sea since the collapse heavy fishing mortality as well as predation on cod eggs by sprat and food competition between sprat and young of the year cod has inhibited cod recovery coincidentally with the decline in the cod stock since 1982 and following the consequent reduction in predation pressure the sprat stock increased rapidly and salmon therefore had more food salmon grew faster resulting also in a high cf
the m 84 camouflage pattern danish m 84 pletsløring is the current camouflage pattern of the danish military the m 84 is a derivative of the flecktarn b pattern produced by the german firm marquardt schulz using the same shapes and pattern the number of colours was changed from 5 to 3 – choosing olive green light green and black to better match the colouration of the danish woodland environment the use of spots creates a dithering effect which eliminates hard boundaries between the different colors in much the same way the squares in the newest digital camouflage patterns do the pattern is designed for use in temperate woodland terrain it has been adapted as desert camouflage by varying the colors it is currently being replaced by m 11
m 90 camouflage is the camouflage pattern used by the swedish armed forces in addition to the standard pattern desert and jungle variants have been developed for the international peace keeping missions in afghanistan and liberia the pattern employs basically a downscaled pattern of what has been used on vehicles since the late 1970 s consisting of hard lined geometric shapes in order to create a camouflage pattern effective in the temperate forests and plains of sweden m 90 camouflage comprises four colours dark green medium green dark navy blue and grey navy blue was chosen instead of black because natural shadows generally tend to be in shades of blue to the human eye
malt lymphoma maltoma is a form of lymphoma involving the mucosa associated lymphoid tissue malt frequently of the stomach but virtually any mucosal site can be afflicted it is a cancer originating from b cells in the marginal zone of the malt and is also called extranodal marginal zone b cell lymphoma
marpat short for marine pattern is a digital camouflage pattern in use with the united states marine corps designed by timothy o neill and introduced with the marine corps combat utility uniform mccuu which replaced the camouflage utility uniform its design and concept are based on the canadian cadpat pattern the pattern is formed of small rectangular pixels of color in theory it is a far more effective camouflage than standard uniform patterns because it mimics the dappled textures and rough boundaries found in natural settings it is also known as the digital pattern or digi cammies because of its micropattern pixels rather than the old macropattern big blobs the united states government has patented marpat including specifics of its manufacture by regulation the pattern and items incorporating it such as the mccuu and ilbe backpack are to be supplied by authorized manufacturers only and are not for general commercial sale although imitations are available such as digital woodland camo or digital desert camo marpat was also chosen because it distinctively identifies its wearers as marines to their adversaries while simultaneously helping its wearers remain concealed this was demonstrated by a marine spokesman at the launch of marpat who stated we want to be instantly recognized as a force to be reckoned with we want them to see us coming a mile away in our new uniforms as such the us marine corps restricts use of the camouflage preventing its use in most other divisions of the united states military
masa syndrome also called crash syndrome and gareis mason syndrome is a rare x linked recessive neurological disorder
mash 1 modular arithmetic secure hash is a hash function based on modular arithmetic
mass phenotype is a medical disorder similar to marfan syndrome mass stands for mitral valve prolapse aortic root diameter at upper limits of normal for body size stretch marks of the skin and skeletal conditions similar to marfan syndrome mass phenotype is a connective tissue disorder that is similar to marfan syndrome it is caused by a similar mutation in the gene called fibrillin 1 that tells the body how to make an important protein found in connective tissue someone with mass phenotype has a 50 percent chance of passing the gene along to each child people with features of mass phenotype need to see a doctor who knows about connective tissue disorders for an accurate diagnosis often this will be a medical geneticist it is very important that people with mass phenotype get an early and correct diagnosis so they can get the right treatment mass stands for the mitral valve myopia aorta skin and skeletal features of the disorder mass phenotype affects different people in different ways in mass phenotype mitral valve prolapse may be present this is when the flaps of one of the heart ’ s valves the mitral valve which regulates blood flow on the left side of the heart are “ floppy ” and don ’ t close tightly aortic root diameter may be at the upper limits of normal for body size but unlike marfan syndrome there is not progression to aneurysm or predisposition to dissection skin may show stretch marks unrelated to weight gain or loss striae skeletal features including curvature of the spine scoliosis chest wall deformities and joint hypermobility may be present people with mass phenotype do not have lens dislocation but have myopia also known as nearsightedness mass syndrome and marfan syndrome are overlapping connective tissue disorders both can be caused by mutations in the gene encoding a protein called fibrillin these conditions share many of the same signs and symptoms including long limbs and fingers chest wall abnormalities indented chest bone or protruding chest bone flat feet scoliosis mitral valve prolapse loose or hypextensible joints highly arched roof of the mouth and mild dilatation of the aortic root individuals with mass syndrome do not have progressive aortic enlargement or lens dislocation while people with marfan syndrome do skin involvement in mass syndrome is typically limited to stretch marks striae distensae also the skeletal symptoms of mass syndrome are generally mild
max 3 lin eqn is a problem in computational complexity theory where the input is a system of linear equations modulo 2 each equation contains at most 3 variables the problem is to find an assignment to the variables that satisfies the maximum number of equations this problem is closely related to the max 3 sat problem it is np hard to approximate max 3 lin eqn with ratio 1 2 δ for any δ 0
max 3 sat is a problem in the computational complexity subfield of computer science it generalises the boolean satisfiability problem sat which is a decision problem considered in complexity theory it is defined as given a 3 cnf formula φ i e with at most 3 variables per clause find an assignment that satisfies the largest number of clauses max 3 sat is a canonical complete problem for the complexity class maxsnp shown complete in papadimitriou pg 314
maxeksat is a problem in computational complexity theory that is a maximization version of the boolean satisfiability problem 3 sat in maxeksat each clause has exactly k literals each with distinct variables and is in conjunctive normal form these formulas are called k cnf formulas the problem is to determine the maximum number of clauses that can be satisfied by a truth assignment to the variables in the clauses we say that an algorithm a provides an α approximation to maxeksat if for some fixed positive α less than or equal to 1 and every kcnf formula φ a can find a truth assignment to the variables of φ that will satisfy at least an α fraction of the maximum number of satisfiable clauses of φ because the np hard k sat problem for k ≥ 3 is equivalent to determining if the corresponding maxeksat instance has a value equal to the number of clauses maxeksat must also be np hard meaning that there is no polynomial time algorithm unless p np a natural next question then is that of finding approximate solutions what s the largest real number α 1 such that some explicit p complexity algorithm always finds a solution of size α · opt where opt is the potentially hard to find maximizing assignment
mbl deficiency refers to mannan binding lectin pathway components such as mbl 2 it is thought that 5 10 of the population have an mbl deficiency of some degree there are varying degrees of mbl deficiency some people in a given population will not even know they have the deficiency while others may have such low levels that they experience infections with great frequency babies and young children are most at risk
multi constrained optimal path selection or mcop is a network path selection problem
the md 2 message digest algorithm is a cryptographic hash function developed by ronald rivest in 1989 the algorithm is optimized for 8 bit computers md 2 is specified in although md 2 is no longer considered secure even as of 2014 it remains in use in public key infrastructures as part of certificates generated with md 2 and rsa
the md 4 message digest algorithm is a cryptographic hash function developed by ronald rivest in 1990 the digest length is 128 bits the algorithm has influenced later designs such as the md 5 sha 1 and ripemd algorithms the security of md 4 has been severely compromised the first full collision attack against md 4 was published in 1995 and several newer attacks have been published since then as of 2007 an attack can generate collisions in less than 2 md 4 hash operations a theoretical preimage attack also exists a variant of md 4 is used in the ed 2 k uri scheme to provide a unique identifier for a file in the popular edonkey 2000 emule p 2 p networks md 4 was also used by the rsync protocol prior to version 3 0 0 md 4 is used to compute ntlm password derived key digests on microsoft windows nt xp vista 7 8 and 10
the md 6 message digest algorithm is a cryptographic hash function it uses a merkle tree like structure to allow for immense parallel computation of hashes for very long inputs authors claim a performance of 28 cycles per byte for md 6 256 on an intel core 2 duo and provable resistance against differential cryptanalysis the source code of the reference implementation was released under mit license speeds in excess of 1 gb s have been reported to be possible for long messages on 16 core cpu architecture the design of merkle tree is based on the claims from intel describing the future of hardware processors with tens and thousands of cores instead of the conventional uni core systems with this in mind merkle tree hash structures exploit full potential of such hardware while being appropriate for current uni dual core architectures in december 2008 douglas held of fortify software discovered a buffer overflow in the original md 6 hash algorithm s reference implementation this error was later made public by ron rivest on 19 february 2009 with a release of a corrected reference implementation in advance of the fortify report md 6 was submitted to the nist sha 3 competition however on july 1 2009 rivest posted a comment at nist that md 6 is not yet ready to be a candidate for sha 3 because of speed issues a gap in the proof that the submitted version of md 6 is resistant to differential attacks and an inability to supply such a proof for a faster reduced round version although rivest also stated at the md 6 website that it is not withdrawn formally md 6 did not advance to the second round of the sha 3 competition in september 2011 a paper presenting an improved proof that md 6 and faster reduced round versions are resistant to differential attacks was posted to the md 6 website the algorithm s first known production use was in the conficker b worm in december 2008 the worm s authors subsequently updated conficker with the corrected implementation once the buffer overflow vulnerability became known
in cryptography mdc 2 modification detection code 2 sometimes called meyer schilling is a cryptographic hash function mdc 2 is a hash function based on a block cipher with a proof of security in the ideal cipher model the length of the output hash depends on the underlying block cipher used
mecp 2 duplication sydrome m 2 ds is a rare x linked genetic disorder that causes the over expression of mecp 2 protein it largely affects young male individuals the primary symptoms of m 2 ds include infantile hypotonia delayed psychomotor development impaired speech abnormal or absent gait epilepsy spasticity gastrointestinal motility problems recurrent infections and early death signs of this disorder are confused with those of autism spectrum disorders and cerebral palsy the incidence of m 2 ds is currently unknown but thought to represent 1 of x linked male mental disability cases recent technological breakthroughs in communication have shown that children affected by mecp 2 duplication syndrome understand language but cannot speak in the very recent past a combination of non existent or limited speech with poor motor skills had caused these adolescent individuals to present with the cognitive abilities of an infant pioneering communication work with mecp 2 duplication syndrome children and assistive technology eye gaze communication devices have demonstrated that these children have the ability to communicate requests and feelings the genetic abnormality that causes mecp 2 duplication syndrome is a double dose or duplication of the mecp 2 or methyl cpg binding protein 2 gene the mecp 2 protein plays a pivotal role in regulating brain function too little or too much of the mecp 2 protein results in brain dysfunction and physical impairment mutations in the mecp 2 gene are also commonly associated with rett syndrome in females advances in genetic testing and more widespread use of array cgh comparative genomic hybridization has led to increased diagnosis of mecp 2 duplication syndrome array cgh allows for sub microscopic cannot be seen under a microscope detection of missing or additional copies of genetic material and is the best screening test for a child with developmental delay as it will detect a number of genetic disorders including mecp 2 duplication syndrome research into mecp 2 duplication syndrome is in its infancy which means we also do not know the spectrum mildness to severity preliminary studies suggest that prevalence may be 1 8 per 10 000 live male births 50 of cases do not live beyond 25 years of age mecp 2 duplication syndrome reversal in mice in a nature article published on november 25 2015 it was revealed that researchers at the baylor college of medicine led by dr huda y zoghbi have reversed mecp 2 duplication syndrome in adult symptomatic mice using antisense oligonucleotide aso therapy in this landmark letter to nature mice treated with an experimental aso administered through the central nervous system experienced the reduction of mecp 2 protein to normal levels many impressive results were observed several behavioral tests were conducted and in all cases symptoms of hypoactivity anxiety and abnormal social behavior were resolved additionally the seizure activity of the mice and abnormal eeg discharges were abolished lastly initial studies demonstrated that reducing the mecp 2 protein levels to the correct amount also normalized the expression of the other genes controlled by the mecp 2 protein excitingly the aso was also administered to lymphoblastoid cells from mecp 2 duplication syndrome patients and mecp 2 mrna levels were restored to the correct concentration in these cells this groundbreaking research shows that aso gene therapy is a promising approach to treat mecp 2 duplication syndrome further scientific studies need to be conducted before this therapeutic approach can be tested on humans but this study is the first hurdle cleared of the many inherent to the drug development process this research was funded by donations to the rett syndrome research trust mecp 2 duplication fund by the friends and families of children affected by mecp 2 duplication syndrome the 401 project the 401 project was established in 2012 to raise funds to cure mecp 2 duplication syndrome in 2012 a concerted parent driven effort was established to raise funds for the initial mecp 2 reversal experiments conducted at the baylor college of medicine each mecp 2 family pledged to raise 401 00 in funds to cover the research program cost the initiative was a success and the 401 project was born the 401 project name was maintained as it is fundamental to the philosophy the collection of individual efforts produces high impact results the 401 project was established by parents of children affected by mecp 2 duplication syndrome today the 401 project is maintained by a group of parent facilitators who guide fundraising programs scientist interactions research finding translations and social media activities there are very minimal direct costs associated with running the 401 project and these costs are covered by the parent facilitators every penny donated to the 401 project goes to research the rett syndrome research trust mecp 2 duplication syndrome fund all funds raised through the 401 project initiative are directly deposited into the rett syndrome research trust mecp 2 duplication syndrome fund the rett syndrome research trust rsrt is a registered non profit organization and all donations are fully tax deductible both rett syndrome and mecp 2 duplication syndrome are caused by mutations in the mecp 2 gene rett syndrome affected individuals do not produce enough mecp 2 protein in their brains while mecp 2 duplication affected individuals produce far too much mecp 2 protein research conducted on the earlier discovered rett syndrome was easily leveraged to initiate promising research to cure mecp 2 duplication syndrome rsrt was founded in 2008 by monica coenraads since 1999 monica has led the surge in research for genetic disorders caused by mutations in the mecp 2 gene the mecp 2 duplication community is beyond fortunate that monica has championed mecp 2 duplication syndrome research under the rsrt umbrella under monica s leadership over 40 000 000 has been raised for research on mecp 2 associated genetic disorders rsrt operates by constantly engaging academic scientists clinicians industry investors and affected families these relationships catalyze the development and execution of a research agenda that neither academia nor industry could achieve alone rsrt identifies solicits evaluates prioritizes funds and monitors ambitious research projects that have the greatest likelihood of impacting the lives of those afflicted with rett syndrome and mecp 2 duplication syndrome
mitochondrial encephalomyopathy lactic acidosis and stroke like episodes – abbreviated to melas – is one of the family of mitochondrial cytopathies which also include merrf and leber s hereditary optic neuropathy it was first characterized under this name in 1984 a feature of these diseases is that they are caused by defects in the mitochondrial genome which is inherited purely from the female parent however it is important to know that some of the proteins essential to normal mitochondrial function are produced by the nuclear genome and are subsequently transported to the mitochondria for use as such mutations in these proteins can result in mitochondrial disorders but can be inherited from both male and female parent in the typical fashion the disease can manifest in both sexes
merrf syndrome or myoclonic epilepsy with ragged red fibers is a mitochondrial disease it is extremely rare with an estimated prevalence of 1 400 000 in northern europe and has varying degrees of expressivity owing to heteroplasmy
mgus polyneuropathy or polyneuropathy associated with an m component is a rare neurological disease characterized by inflammation of the peripheral nervous system and monoclonal gammopathy of undetermined significance mgus it was first described in the 1960 s the main symptoms are progressive muscle weakness that is symmetrical and bilateral ataxia numbness and arm tremor treatments include intravenous immunoglobulin which is a short term treatment immunosuppressants though they have not been shown to be effective autologous stem cell transplantation and rituximab
mody 1 is a form of maturity onset diabetes of the young mody 1 is due to a loss of function mutation in the hnf 4 a gene on chromosome 20 this gene codes for hnf 4 α protein also known as transcription factor 14 tcf 14 hnf 4 α controls function of hnf 1 α see mody 3 hnf 1 a and perhaps hnf 1 β mody 5 as well this transcription network plays a role in the early development of the pancreas liver and intestines in the pancreas these genes influence expression of among others the genes for insulin the principal glucose transporter glut 2 and several proteins involved in glucose and mitochondrial metabolism although pancreatic beta cells produce adequate insulin in infancy the capacity for insulin production declines thereafter diabetes persistent hyperglycemia typically develops by early adult years but may not appear until later decades the degree of insulin deficiency is slowly progressive many patients with mody 1 are treated with sulfonylureas for years before insulin is required liver effects are subtle and not clinically significant many people with this condition have low levels of triglycerides lipoprotein a apolipoproteins aii and ciii mutations in the alternative promoter of hnf 4 a are linked to development of type 2 diabetes
mody 2 is a form of maturity onset diabetes of the young mody 2 is due to any of several mutations in the gck gene on chromosome 7 for glucokinase glucokinase serves as the glucose sensor for the pancreatic beta cell normal glucokinase triggers insulin secretion as the glucose exceeds about 90 mg dl 5 mm these loss of function mutations result in a glucokinase molecule that is less sensitive or less responsive to rising levels of glucose the beta cells in mody 2 have a normal ability to make and secrete insulin but do so only above an abnormally high threshold e g 126 – 144 mg dl or 7 8 mm this produces a chronic mild increase in blood sugar which is usually asymptomatic it is usually detected by accidental discovery of mildly elevated blood sugar e g during pregnancy screening an oral glucose tolerance test is much less abnormal than would be expected from the impaired elevated fasting blood sugar since insulin secretion is usually normal once the glucose has exceeded the threshold for that specific variant of the glucokinase enzyme the degree of blood sugar elevation does not worsen rapidly with age and long term diabetic complications are rare in healthy children and adults a high blood sugar level can be avoided by a healthy diet and exercise primarily avoiding large amounts of carbohydrates however as people who have mody 2 enter their 50 s and 60 s even though they continue to eat a healthy diet and exercise they sometimes are unable to control a high blood sugar level with these measures in these cases many medicines for type ii diabetes mellitus are not effective because mody 2 does not cause insulin resistance repaglinide prandin can help the body regulate the amount of glucose in the blood by stimulating the pancreas to release insulin before meals in some cases the baseline glucose levels are too high as well and insulin is required mody 2 is an autosomal dominant condition autosomal dominance refers to a single abnormal gene on one of the first 22 nonsex chromosomes from either parent which can cause an autosomal disorder dominant inheritance means an abnormal gene from one parent is capable of causing disease even though the matching gene from the other parent is normal the abnormal gene dominates the pair of genes if just one parent has a dominant gene defect each child has a 50 chance of inheriting the disorder this type of mody demonstrates the common circulation but complex interplay between maternal and fetal metabolism and hormone signals in the determination of fetal size a small number of infants will have a new mutation not present in their mothers if the mother is affected and the fetus is not the maternal glucose will be somewhat high and the normal pancreas of the fetus will make lots of insulin resulting in a large infant if the fetus is affected but mother is not glucoses will be normal and fetal insulin production will be low resulting in intrauterine growth retardation finally if both mother and fetus have the disease the two defects will offset each other and fetal size will be unaffected when both gck genes are affected the diabetes appears earlier and the hyperglycemia is more severe a form of permanent neonatal diabetes has been caused by homozygous mutations in the gck gene
mody 3 is a form of maturity onset diabetes of the young mody 3 also known as hnf 1 a mody is caused by mutations of the hnf 1 alpha gene a homeobox gene on chromosome 12 this is the most common type of mody in populations with european ancestry accounting for about 70 of all cases in europe hnf 1 α is a transcription factor also known as transcription factor 1 tcf 1 that is thought to control a regulatory network including among other genes hnf 1 α important for differentiation of beta cells mutations of this gene lead to reduced beta cell mass or impaired function mody 1 and mody 3 diabetes are clinically similar about 70 of people develop this type of diabetes by age 25 years but it occurs at much later ages in a few this type of diabetes can often be treated with sulfonylureas with excellent results for decades however the loss of insulin secretory capacity is slowly progressive and most eventually need insulin this is the form of mody which can most resemble ordinary type 1 diabetes and one of the incentives for diagnosing it is that insulin may be discontinued or deferred in favor of oral sulfonylureas some people treated with insulin for years due to a presumption of type 1 diabetes have been able to switch to pills and discontinue injections long term diabetic complications can occur if the glucose is not adequately controlled high sensitivity measurements of crp may help to distinguish between hnf 1 a mody and other forms of diabetes
renal cysts and diabetes syndrome rcad also known as mody 5 is a form of maturity onset diabetes of the young hnf 1 β related mody is one of the less common forms of mody with some distinctive clinical features including atrophy of the pancreas and several forms of renal disease hnf 1 β also known as transcription factor 2 tcf 2 is involved in early stages of embryonic development of several organs including the pancreas where it contributes to differentiation of pancreatic endocrine ngn 3 cell progenitors from non endocrine embryonic duct cells the gene is on chromosome 17 q the degree of insulin deficiency is variable diabetes can develop from infancy through middle adult life and some family members who carry the gene remain free of diabetes into later adult life most of those who develop diabetes show atrophy of the entire pancreas with mild or subclincal deficiency of exocrine as well as endocrine function the non pancreatic manifestations are even more variable kidney and genitourinary malformation and diseases may occur but inconsistently even within a family and the specific conditions include a range of apparently unrelated anomalies and processes the most common genitourinary condition is cystic kidney disease but there are many varieties even of this renal effects begin with structural alterations small kidneys renal cysts anomalies of the renal pelvis and calices but a significant number develop slowly progressive renal failure associated with chronic cystic disease of the kidneys in some cases renal cysts may be detected in utero kidney disease may develop before or after hyperglycemia and a significant number of people with mody 5 are discovered in renal clinics with or without kidney disease some people with forms of hnf 1 β have had various minor or major anomalies of the reproductive system male defects have included epididymal cysts agenesis of the vas deferens or infertility due to abnormal spermatozoa affected women have been found to have vaginal agenesis hypoplastic or bicornuate uterus liver enzyme elevations are common but clinically significant liver disease is not hyperuricaemia and early onset gout have occurred
momo syndrome is an extremely rare genetic disorder which belongs to the overgrowth syndromes and has been diagnosed in only six cases around the world and occurs in 1 in 100 million births the name is an acronym of the four primary aspects of the disorder macrosomia excessive birth weight obesity macrocephaly excessive head size and ocular abnormalities it is unknown if it is a life limiting condition momo syndrome was first diagnosed in 1993 by professor célia priszkulnik koiffmann a brazilian researcher in the genetic and clinical studies of neurodevelopmental disorders this syndrome s acronym is an intended pun it refers to the traditionally tall and obese king of carnivals momus — rei momo in portuguese
moose originally an acronym for man out of space easiest but later changed to the more professional sounding manned orbital operations safety equipment was a proposed emergency bail out system capable of bringing a single astronaut safely down from earth orbit to the planet s surface the design was proposed by general electric in the early 1960 s the system was quite compact weighing 200 pounds 90 kilograms and fitting inside a suitcase sized container it consisted of a small twin nozzle rocket motor sufficient to deorbit the astronaut a pet film bag six feet 1 8 metres long with a flexible quarter inch thick ablative heat shield on the back two pressurized canisters to fill it with polyurethane foam a parachute radio equipment and a survival kit the astronaut would leave the vehicle in a space suit climb inside the plastic bag and then fill it with foam the bag had the shape of a blunt cone with the astronaut embedded in its base facing outward the rocket pack would protrude from the bag and be used to slow the astronaut s orbital speed enough so that they would reenter earth s atmosphere and the foam filled bag would act as insulation during the subsequent aerobraking finally once the astronaut had descended to 30 000 feet 9 km where the air was sufficiently dense the parachute would automatically deploy and slow the astronaut s fall to 17 mph 7 6 metres per second the foam heat shield would serve a final role as cushioning when the astronaut touched down and as a flotation device should they land on water the radio beacon would guide rescuers general electric performed preliminary testing on some of the components of the moose system including flying samples of heat shield material on a mercury mission inflating a foam filled bag with a human subject embedded inside and test dropping dummies in moose foam shields short distances u s air force capt joe kittinger s historic freefall from a balloon at 103 000 feet 31 395 meters in august 1960 also helped demonstrate the feasibility of such extreme parachuting however the moose system was nonetheless always intended as an extreme emergency measure when no other option for returning an astronaut to earth existed falling from orbit protected by nothing more than a spacesuit and a bag of foam was unlikely to ever become a particularly safe — or enticing — maneuver neither nasa nor the u s air force expressed an interest in the moose system and so by the end of the 1960 s the program was quietly shelved
morm syndrome is an autosomal recessive congenital disorder this means that the disorder is present from birth and is likely the result of both healthy parents passing on a defective gene associated with morm syndrome to their offspring the disorder is not dependent on sex of the offspring both male and female offspring are equally likely to inherit the disorder the term morm is used to describe the characteristics associated with the disorder which include mental retardation truncal obesity retinal dystrophy and micropenis the disorder shares similar characteristics with bardet biedl syndrome and cohen syndrome both of which are autosomal recessive genetic disorders morm syndrome can be distinguished from the above disorders because symptoms appear at a young age the syndrome is caused by a mutation in the inpp 5 e gene which can be located on chromosome 9 in humans further mapping resulted in the identification of a morm syndrome locus on chromosome 9 q 34 3 between the genetic markers d 9 s 158 and d 9 s 905
mpx filter is a function found in cassette decks fm stereo broadcasts contain a pilot tone at 19 khz when stereo information is available at higher frequencies this system was developed jointly by zenith and general electric the normal monaural audio the pilot tone which serves as a phase reference when decoding the stereophonic information and the double sideband stereophonic difference information are all mixed and broadcast together the process of encoding the difference signal into the 23 53 khz band via double sideband carrier suppressed amplitude modulation is an instance of multiplexing residual high frequency components of the signal remaining after de multiplexing can be problematic when recording to analog magnetic media while the higher frequencies are unlikely to survive filtering in the recording deck the 19 khz tone is within the 20 to 20 000 hz frequency range for many tape formats including compact cassette and typically provides an audible beat difference tone in conjunction with the tape head bias signal used when recording the recording may also be saturated by the pilot tone more importantly the pilot tone interferes with the proper functioning of noise reduction systems such as dolby b c and s because the pilot tone is relatively loud in comparison to the overall loudness of the fm program typically 20 db the source signal is not correctly processed by the noise reduction system leading to audible artefacts such as breathing and pumping for this reason many decks with defeatable mpx filters have been designed in such a way that the mpx filter can only be enabled when also a noise reduction system is enabled an mpx filter on a tape deck is at least a notch filter that will block the 19 khz pilot tone and possibly higher frequencies in the 23 53 khz and 63 75 khz bands the difference can be heard when recording from an fm stereo source and engaging and disengaging the mpx filter switch on a three head deck with monitoring this can be heard while recording the filter should not be engaged when recording from other sources such as compact disc the setting of the switch has no effect during playback decks with no mpx filter switch typically have a non defeatable mpx filter incorporated in their design which limits the overall i e record to playback frequency response to about 15 16 khz
mvc 4 wpf is an open source extensible automated code pattern developed at information control corporation for windows presentation foundation wpf development based on the model view controller mvc and presentation abstraction control pac patterns it was released to the general public as an open source project on july 23 2009 it depends on microsoft ’ s net framework 3 5 and visual studio 2008 for functionality the mvc 4 wpf source code for the 0 9 beta is available for download on codeplex
in mathematics a maass wave form or maass form is a function on the upper half plane that transforms like a modular form but need not be holomorphic they were first studied by hans maass in
in probability theory the mabinogion sheep problem or mabinogian urn is a problem in stochastic control introduced by david williams 15 3 who named it after a herd of magic sheep in the welsh epic mabinogion
mac callum s plaques is a condition featuring the thickening of left atrium s wall and its endocardial wall above the mitral valve due to fibrosis it is one complication of chronic rheumatic heart disease other complications of chronic rheumatic heart disease are valvular effect stenosis insufficiency or can be both valvular leaflets become thickened by fibrosis frequent valvular calcification cordae tendinae become thickened shortened and fused
mach reflection is a supersonic fluid dynamics effect named for ernst mach and is a shock wave reflection pattern involving three shocks
mach tuck is an aerodynamic effect whereby the nose of an aircraft tends to pitch downward as the airflow around the wing reaches supersonic speeds the aircraft will first experience this effect at significantly below mach 1 this speed is known as the critical mach number of the wing
machado – joseph disease mjd also known as machado – joseph azorean disease or joseph s disease or spinocerebellar ataxia type 3 sca 3 is a rare autosomal dominantly inherited neurodegenerative disease that causes progressive cerebellar ataxia which results in a lack of muscle control and coordination of the upper and lower extremities the symptoms are caused by a genetic mutation that results in an expansion of abnormal cag trinucleotide repeats in the atxn 3 gene that results in an abnormal form of the protein ataxin which causes degeneration of cells in the hindbrain some symptoms such as clumsiness and rigidity make mjd commonly mistaken for drunkenness or parkinson s disease machado – joseph disease is a type of spinocerebellar ataxia and is the most common cause of autosomal dominant ataxia mjd causes ophthalmoplegia and mixed sensory and cerebellar ataxia
a machine check exception mce is a type of computer hardware error that occurs when a computer s central processing unit detects a hardware problem modern versions of microsoft windows handle machine check exceptions through the windows hardware error architecture when whea detects a machine check exception it displays the error in a blue screen of death with the following parameters which vary but the first parameter is always 0 x 0 for a machine check exception stop 0 x 00000124 0 x 0000000000000000 0 x 0000000000000000 0 x 0000000000000000 0 x 0000000000000000 on linux a process such as klogd writes a message to the kernel log and or the console screen usually only to the console when the error is non recoverable and the machine crashes as a result cpu 0 machine check exception 0000000000000004 bank 2 f 200200000000863 kernel panic cpu context corrupt the error usually occurs due to failure or overstressing of hardware components where the error cannot be more specifically identified with a different error message diagnosing the error message can be difficult although intel pentium processors do generate more specific codes which can be decoded by contacting the manufacturer most mces require a restart of the system before users can continue normal operation and indicate a long term problem of a general nature
machine learning is the subfield of computer science that gives computers the ability to learn without being explicitly programmed arthur samuel 1959 evolved from the study of pattern recognition and computational learning theory in artificial intelligence machine learning explores the study and construction of algorithms that can learn from and make predictions on data – such algorithms overcome following strictly static program instructions by making data driven predictions or decisions through building a model from sample inputs machine learning is employed in a range of computing tasks where designing and programming explicit algorithms is unfeasible example applications include spam filtering optical character recognition ocr search engines and computer vision machine learning is closely related to and often overlaps with computational statistics which also focuses in prediction making through the use of computers it has strong ties to mathematical optimization which delivers methods theory and application domains to the field machine learning is sometimes conflated with data mining where the latter subfield focuses more on exploratory data analysis and is known as unsupervised learning within the field of data analytics machine learning is a method used to devise complex models and algorithms that lend themselves to prediction in commercial use this is known as predictive analytics these analytical models allow researchers data scientists engineers and analysts to produce reliable repeatable decisions and results and uncover hidden insights through learning from historical relationships and trends in the data
macrocephaly is a condition in which the head is abnormally large this includes the scalp the cranial bone and the contents of the cranium
macrocephaly capillary malformation m cm is a multiple malformation syndrome causing abnormal body and head overgrowth and cutaneous vascular neurologic and limb abnormalities though not every patient has all features commonly found signs include macrocephaly congenital macrosomia extensive cutaneous capillary malformation naevus flammeus or port wine stain type birthmark over much of the body a capillary malformation of the upper lip or philtrum is seen in many patients with this condition body asymmetry also called hemihyperplasia or hemihypertrophy polydactyly or syndactyly of the hands and feet lax joints doughy skin variable developmental delay and other neurologic problems such as seizures and low muscle tone
macrocheilia is a condition of permanent swelling of the lip that results from greatly distended lymphatic spaces this causes an abnormal largeness of the lips this is sometimes seen in leprosy patients
macrocytosis is the enlargement of red blood cells with near constant hemoglobin concentration and is defined by a mean corpuscular volume mcv of greater than 100 femtolitres the precise criterion varies between laboratories the enlarged erythrocytes are called macrocytes or megalocytes both words have roots meaning big cell
macrodontia or megadontia or megalodontia is a type of localized gigantism in which teeth are larger than normal for the particular type s of teeth involved the three types of macrodontia are true generalized macrodontia relative generalized macrodontia and macrodontia of a single tooth true generalized macrodontia is rare macrodontia of a single tooth is more common some kind of macrodontia in the permanent dentition occurs in 1 1 of the total population it should not be confused with taurodontism bull teeth fusion double tooth or the jaws being relatively small giving the appearance of macrodontia
macroecology is the subfield of ecology that deals with the study of relationships between organisms and their environment at large spatial scales to characterise and explain statistical patterns of abundance distribution and diversity the term was coined by james brown of the university of new mexico and brian maurer of michigan state university in a 1989 paper in science macroecology approaches the idea of studying ecosystems using a top down approach it seeks understanding through the study of the properties of the system as a whole kevin gaston and tim blackburn make the analogy to seeing the forest for the trees macroecology examines how global development in climate change affect wildlife populations classic ecological questions amenable to study through the techniques of macroecology include questions of species richness latitudinal gradients in species diversity the species area curve range size body size and species abundance for example the relationship between abundance and range size why species that maintain large local population sizes tend to be widely distributed while species that are less abundant tend to have restricted ranges has received much attention
macroglobulinemia is the presence of increased levels of macroglobulins in the circulating blood it is a plasma cell dyscrasia resembling leukemia with cells of lymphocytic plasmacytic or intermediate morphology which secrete a monoclonal immunoglobulin m component there is diffuse infiltration by the malignant cells of the bone marrow and also in many cases of the spleen liver or lymph nodes the circulating macroglobulin can produce symptoms of hyperviscosity syndrome weakness fatigue bleeding disorders and visual disturbances peak incidence of macroglobulinemia is in the sixth and seventh decades of life dorland 28 th ed
macroglossia is the medical term for an unusually large tongue severe enlargement of the tongue can cause cosmetic and functional difficulties in speaking eating swallowing and sleeping macroglossia is uncommon and usually occurs in children there are many causes treatment is dependent upon the exact cause
macroorchidism is a disorder found in males where a subject has abnormally large testes the condition is commonly inherited in connection with fragile x syndrome which is also the second most common genetic cause of mental disabilities the opposite side of the spectrum is called microorchidism which is the condition of abnormally small testes other possible etiologies of macroorchidism are long standing primary hypothyroidism adrenal remnants in congenital adrenal hyperplasia follicle stimulating hormone fsh secreting pituitary macroadenomas local tumors lymphomas and aromatase deficiency
macrophagic myofasciitis or mmf is a rare muscle disease identified in 1993 the disease is characterized by microscopic lesions found in muscle biopsies that show infiltration of muscle tissue by pas positive macrophages specific causes of mmf are unknown intramuscular injections aluminium containing vaccines have been implicated many of those affected with the disease had previously been treated for malaria with chloroquine or hydroxychloroquine clinical symptoms include muscle pain joint pain muscle weakness fatigue fever and muscle tenderness a diagnosis can only be identified with an open muscle biopsy of the vaccinated muscle studies at the university of paris have shown that mmf lesions result when the aluminum hydroxide adjuvant from a vaccine remains embedded in the tissue and causes a steady immune reaction
macropsia also known as megalopia is a neurological condition affecting human visual perception in which objects within an affected section of the visual field appear larger than normal causing the person to feel smaller than they actually are macropsia along with its opposite condition micropsia can be categorized under dysmetropsia macropsia is related to other conditions dealing with visual perception such as aniseikonia and alice in wonderland syndrome aiws also known as todd ’ s syndrome macropsia has a wide range of causes from prescription and illicit drugs to migraines and rarely complex partial epilepsy and to different retinal conditions such as epiretinal membrane physiologically retinal macropsia results from the compression of cones in the eye it is the compression of receptor distribution that results in greater stimulation and thus a larger perceived image of an object
in quantum mechanics macroscopic quantum self trapping is a phenomenon occurring in the state of matter called the bose – einstein condensate between two superconductors linked by a non conducting barrier known as a josephson junction while the tunneling of a particle through classically forbidden barriers can be described by the particle s wave function this merely gives the probability of tunneling although various factors can increase or decrease the probability of tunneling one can not be certain whether or not tunneling will occur when two condensates are placed in a double potential well and the phase and population differences are such that the system is in equilibrium the population difference will remain fixed this is not to say that tunneling does not occur — rather in the event that a particle tunnels through the barrier another particle tunnels in the opposite direction because the identity of individual particles is lost in that case no tunneling can be observed and the system is considered to remain at rest
macrostomia from the greek prefix makro meaning large and from greek στόμα mouth refers to a mouth that is unusually wide macrostomia is characterized as a physical abnormality that causes clefts to form on the face of affected individuals these clefts can form on either or both sides of the face but they are most commonly seen on the right cheek and have a higher rate of occurrence in males macrostomia is very irregular and on average occurs only once in every 150 000 to 300 000 live births it s unusual for macrostomia to occur on its own and it is included as a symptom for many diseases including craniofacial microsomia the clefts result from improper development and fusion of the mandibular and maxillary processes the clefts cause problems with facial muscle development the origin of macrostomia is not yet fully understood it could have multiple causes
macrotia refers to an ear which is larger than would be expected the normal auricular axis length is 58 – 62 mm among females and 62 – 66 mm among males in some cases surgery otoplasty is performed to reduce the size
macrovascular disease is a disease of any large macro blood vessels in the body it is a disease of the large blood vessels including the coronary arteries the aorta and the sizable arteries in the brain and in the limbs this sometimes occurs when a person has had diabetes for a long time fat and blood clots build up in the large blood vessels and stick to the vessel walls three common macrovascular diseases are coronary disease in the heart cerebrovascular disease in the brain and peripheral vascular disease in the limbs macrovascular disease macroangiopathy refers to atherosclerosis atherosclerosis is a form of arteriosclerosis thickening and hardening of arterial walls characterized by plaque deposits of lipids fibrous connective tissue calcium and other blood substances atherosclerosis by definition affects only medium and large arteries excluding arterioles macrovascular disease is associated with the development of coronary artery disease peripheral vascular disease brain attack stroke and increased risk of infection type 2 diabetes is more closely associated with macrovascular diseases than type 1 diabetes peripheral vascular disease and increased risk of infection have important implications in the care of the acutely ill patient
macular corneal dystrophy also known as fehr corneal dystrophy named for german ophthalmologist oskar fehr 1871 1959 is a rare pathological condition affecting the stroma of cornea the first signs are usually noticed in the first decade of life and progress afterwards with opacities developing in the cornea and attacks of pain the condition was first described by arthur groenouw in 1890
macular degeneration also known as age related macular degeneration amd or armd is a medical condition which may result in blurred or no vision in the center of the visual field early on there are often no symptoms over time however some people experience a gradual worsening of vision that may affect one or both eyes while it does not result in complete blindness loss of central vision can make it hard to recognize faces drive read or perform other activities of daily life visual hallucinations may also occur but these do not represent a mental illness macular degeneration typically occurs in older people genetic factors and smoking also play a role it is due to damage to the macula of the retina diagnosis is by a complete eye exam the severity is divided into early intermediate and late types the late type is additionally divided into dry and wet forms with the dry form making up 90 of cases prevention includes exercising eating well and not smoking antioxidant vitamins and minerals do not appear to be useful for prevention there is no cure or treatment that returns vision already lost in the wet form anti vegf medication injected into the eye or less commonly laser coagulation or photodynamic therapy may slow worsening supplements in those who already have the disease may slow progression in 2010 it affected 23 5 million people globally in 2013 moderate to severe disease affected 13 4 million and it is the fourth most common cause of blindness after cataracts preterm birth and glaucoma it most commonly occurs in people over the age of fifty and in the united states is the most common cause of vision loss in this age group about 0 4 of people between 50 and 60 have the disease while it occurs in 0 7 of people 60 to 70 2 3 of those 70 to 80 and nearly 12 of people over 80 years old
macular edema occurs when fluid and protein deposits collect on or under the macula of the eye a yellow central area of the retina and causes it to thicken and swell edema the swelling may distort a person s central vision because the macula holds tightly packed cones that provide sharp clear central vision to enable a person to see detail form and color that is directly in the centre of the field of view
a macular hole is a small break in the macula located in the center of the eye s light sensitive tissue called the retina
macular hypoplasia also known as foveal hypoplasia is a rare medical condition involving the underdevelopment of the macula a small area on the retina the eye s internal surface responsible for seeing in detail macular hypoplasia is often associated with albinism
macular telangiectasia describes two distinct retinal diseases affecting the macula of the eye macular telangiectasia type 1 and macular telangiectasia type 2 macular telangiectasia mactel type 1 is a very rare disease typically unilateral and usually affecting male patients mactel type 2 is more frequent than type 1 and generally affects both eyes bilateral it usually affects both sexes equally both types of mactel should not be confused with age related macular degeneration amd from which it can be distinguished by symptoms clinical features pathogenesis and disease management however both amd and mactel eventually lead to photoreceptor atrophy and thus loss of central vision the etiology of both types of mactel is still unknown and no treatment has been found to be effective to prevent further progression because lost photoreceptors cannot be recovered early diagnosis and treatment appear to be essential to prevent loss of visual function several centers are currently trying to find new diagnostics and treatments to understand the causes and biochemical reactions in order to halt or counteract the adverse effects mactel type 2 contemporary research has shown that mactel type 2 is likely a neurodegenerative disease with secondary changes of the blood vessels of the macula although mactel type 2 has been previously regarded as a rare disease it is in fact probably much more common than previously thought the very subtle nature of the early findings in mactel mean the diagnoses are often missed by optometrists and general ophthalmologists due to increased research activity since 2005 many new insights have been gained into this condition since its first description by dr j donald gass in 1982
a maculopapular rash is a type of rash characterized by a flat red area on the skin that is covered with small confluent bumps it may only appear red in lighter skinned people the term maculopapular is a compound macules are small flat discolored spots on the surface of the skin and papules are small raised bumps it is also described as erythematous or red this type of rash is common in several diseases and medical conditions including scarlet fever measles ebola virus disease rubella secondary syphilis congenital syphilis which is asymptomatic the newborn may present this type of rash erythrovirus parvovirus b 19 chikungunya alphavirus zika and heat rash it is also a common manifestation of a skin reaction to the antibiotic amoxicillin or chemotherapy drugs cutaneous infiltration of leukemic cells may also have this appearance maculopapular rash is seen in graft versus host disease gvhd developed after a hematopoietic stem cell transplant bone marrow transplant which can be seen within one week or several weeks after the transplant in the case of gvhd the maculopapular rash may progress to a condition similar to toxic epidermal necrolysis in addition this is the type of rash that some patients presenting with ebola virus hemorrhagic ebo z fever will reveal but can be hard to see on dark skin people it is also seen in patients with marburg hemorrhagic fever a filovirus not unlike ebola this type of rash can be as a result of large doses of niacin or no flush niacin 2000 – 2500 mg used for the management of low hdl cholesterol this type of rash can also be a symptom of sea bather s eruption this stinging pruritic maculopapular rash affects swimmers in some atlantic locales e g florida caribbean long island it is caused by hypersensitivity to stings from the larvae of the sea anemone e g edwardsiella lineate or the thimble jellyfish linuche unguiculata the rash appears where the bathing suit contacts the skin this type of rash can also be a symptom of acute arsenic intoxication appearing 2 weeks later
mad hatter disease or mad hatter syndrome was an occupational disease among hatmakers caused by chronic mercury poisoning it affected those whose felting work involved prolonged exposure to mercury vapors the neurotoxic effects included tremor and the pathological shyness and irritability characteristic of erethism use of inorganic mercury in the form of mercuric nitrate to treat the fur of small animals for the manufacture of felt hats seems to have begun in 17 th century france and from there spread to england by the end of the century with the huguenots by the victorian era the hatters condition had become proverbial as reflected in popular expressions like mad as a hatter and hatters shakes similar phenomena had been described in st petersburg russia in 1829 in france the national academy of medicine described the health hazards in 1869 and in 1898 a law was passed to protect hatmakers from the risks of mercury exposure in britain mercury poisoning among hatters had become a rarity by the turn of the 20 th century in the united states where the occupational illness was thoroughly described in new jersey in 1860 the practice continued until 1941 mercury poisoning in the hatmaking industries of danbury connecticut gave rise to the expression danbury shakes hatmakers in tuscany italy were also affected and exposed workers received financial compensation although lewis carroll s iconic mad hatter character in alice s adventures in wonderland has often been linked to the occupational hazards of hatmaking it is thought that the character was directly inspired by the eccentric furniture dealer theophilus carter
madaline many adaline is a three layer input hidden output fully connected feed forward artificial neural network architecture for classification that uses adaline units in its hidden and output layers i e its activation function is the sign function the three layer network uses memistors three different training algorithms for madaline networks which cannot be learned using backpropagation because the sign function is not differentiable have been suggested called rule i rule ii and rule iii the first of these dates back to 1962 and cannot adapt the weights of the hidden output connection the second training algorithm improved on rule i and was described in 1988 the third rule applied to a modified network with sigmoid activations instead of signum it was later found to be equivalent to backpropagation the rule ii training algorithm is based on a principle called minimal disturbance it proceeds by looping over training examples then for each example it finds the hidden layer unit adaline classifier with the lowest confidence in its prediction tentatively flips the sign of the unit accepts or rejects the change based on whether the network s error is reduced stops when the error is zero additionally when flipping single units signs does not drive the error to zero for a particular example the training algorithm starts flipping pairs of units signs then triples of units etc
madarosis is a condition that results in the loss of eyelashes sometimes eyebrows the term madarosis is greek for the word madao which means to fall off it originally was a disease of only losing eyelashes but it currently is the loss of both eyelashes and eyebrows eyebrows and eyelashes are both important in the prevention of bacteria and other foreign objects from entering the eye a majority of patients with madarosis have leprosy and it was reported that 76 of patients with varying types of leprosy had madarosis
madelung s deformity is usually characterized by malformed wrists and wrist bones accompanied by short stature and is often associated with léri weill dyschondrosteosis it has only been recognized within the past hundred years
the madelung synthesis is a chemical reaction that produces substituted or unsubstituted indoles by the intramolecular cyclization of n phenylamides using strong base at high temperature the madelung synthesis was reported in 1912 by walter madelung when he observed that 2 phenylindole was synthesized using n benzoyl o toluidine and two equivalents of sodium ethoxide in a heated airless reaction common reaction conditions include use of sodium or potassium alkoxide as base in hexane or tetrahydrofuran solvents at temperatures ranging between 200 400 ° c a hydrolysis step is also required in the synthesis the madelung synthesis is important because it is one of few known reactions that produce indoles from a base catalyzed thermal cyclization of n acyl o toluidines the overall reaction for the madelung synthesis follows
maffucci syndrome is a sporadic disease characterized by the presence of multiple enchondromas associated with multiple hemangiomas also lymphangiomas may be apparent
the magilum boat magilum from sumerian ma gi lum a ship of the netherworld in sumerian mythology was one of the valuable items seized by ninurta patron god of lagash in ancient iraq this spoil was hung on an unknown part of his chariot according to the ancient source lines 55 63
magnesemia is the presence of magnesium in the blood low levels of magnesium causes cardiac ventricular arrhythmia note also seizures are cns arrhythmia normal value ranges from 1 5 to 2 meq
magnesium deficiency or hypomagnesia not to be confused with hypomagnesemia refers to inadequate intake of dietary magnesium or impaired absorption of magnesium which can result in numerous symptoms and diseases it is generally corrected by an increase of magnesium in diet oral supplements and in severe cases intravenous supplementation
magnesium has an important role in photosynthesis because it forms the central atom of chlorophyll therefore without sufficient amounts of magnesium plants begin to degrade the chlorophyll in the old leaves this causes the main symptom of magnesium deficiency chlorosis or yellowing between leaf veins which stay green giving the leaves a marbled appearance due to magnesium ’ s mobile nature the plant will first break down chlorophyll in older leaves and transport the mg to younger leaves which have greater photosynthetic needs therefore the first sign of magnesium deficiency is the chlorosis of old leaves which progresses to the young leaves as the deficiency continues magnesium also is a necessary activator for many critical enzymes including ribulosbiphosphate carboxylase rubisco and phosphoenolpyruvate carboxylase pepc both essential enzymes in carbon fixation thus low amounts of mg lead to a decrease in photosynthetic and enzymatic activity within the plants magnesium is also crucial in stabilizing ribosome structures hence a lack of magnesium causes depolymerization of ribosomes leading to pre mature aging of the plant after prolonged magnesium deficiency necrosis and dropping of older leaves occurs plants deficient in magnesium also produce smaller woodier fruits magnesium deficiency may be confused with zinc or chlorine deficiencies viruses or natural ageing since all have similar symptoms adding epsom salts as a solution of 25 grams per liter or 4 oz per gal or crushed dolomitic limestone to the soil can rectify magnesium deficiencies for a more organic solution applying home made compost mulch can prevent leaching during excessive rainfall and provide plants with sufficient amounts of nutrients including magnesium
magnetic catalysis is a physics phenomenon which is defined as an enhancement of dynamical symmetry breaking by an external magnetic field in quantum field theory used for the description of quantum particles quasiparticles in subatomic physics as well as in condensed matter physics the underlying phenomenon is a consequence of the strong tendency of a magnetic field to enhance binding of oppositely charged particles into bound states the “ catalyzing ” effect comes from a partial restriction dimensional reduction of the motion of charged particles in the directions perpendicular to the direction of the magnetic field commonly the magnetic catalysis is specifically associated with spontaneous breaking of flavor or chiral symmetry in quantum field theory which is enhanced or triggered by the presence of an external magnetic field
magnetic deviation is the error induced in a compass by local magnetic fields which must be allowed for along with magnetic declination if accurate bearings are to be calculated more loosely magnetic deviation is used by some to mean the same as magnetic declination this article is about the former meaning
a magnetic field is the magnetic effect of electric currents and magnetic materials the magnetic field at any given point is specified by both a direction and a magnitude or strength as such it is a vector field the term is used for two distinct but closely related fields denoted by the symbols b and h where h is measured in units of amperes per meter symbol a · m − 1 or a m in the si b is measured in teslas symbol t note that although the symbol is capital t tesla is written in lower case in the si system and newtons per meter per ampere symbol n · m − 1 · a − 1 or n m · a in the si b is most commonly defined in terms of the lorentz force it exerts on moving electric charges magnetic fields can be produced by moving electric charges and the intrinsic magnetic moments of elementary particles associated with a fundamental quantum property their spin in special relativity electric and magnetic fields are two interrelated aspects of a single object called the electromagnetic tensor the split of this tensor into electric and magnetic fields depends on the relative velocity of the observer and charge in quantum physics the electromagnetic field is quantized and electromagnetic interactions result from the exchange of photons in everyday life magnetic fields are most often encountered as a force created by permanent magnets which pull on ferromagnetic materials such as iron cobalt or nickel and attract or repel other magnets magnetic fields are widely used throughout modern technology particularly in electrical engineering and electromechanics the earth produces its own magnetic field which is important in navigation and it shields the earth s atmosphere from solar wind rotating magnetic fields are used in both electric motors and generators magnetic forces give information about the charge carriers in a material through the hall effect the interaction of magnetic fields in electric devices such as transformers is studied in the discipline of magnetic circuits
magnetic resonance imaging burn also known as an mri burn is a cutaneous condition characterized by first second or third degree burns due to metal or wire contact with skin creating a closed loop conduction system
in telecommunication magneto ionic double refraction is the combined effect of the earth s magnetic field and atmospheric ionization whereby a linearly polarized wave entering the ionosphere is split into two components called the ordinary wave and extraordinary wave the component waves follow different paths experience different attenuations have different phase velocities and in general are elliptically polarized in opposite senses the critical frequency of the extraordinary wave is always greater than the critical frequency of the ordinary wave i e the wave in absence of the magnetic field by the amount approximately equal to 5 times of gyro frequency the amplitude of extraordinary wave is dependent on the earth magnetic field at that particular point beside splitting the polarization of the incident radio wave is also effected by this phenomena because the electron that were earlier in simple harmonic motion only are now in spiral motion too due to the magnetic field
mahagauri devnagari महागौरी is the eighth manifestation of goddess durga and amongst the navadurgas mahagauri is worshipped on the eighth day of navratri according to hindu mythology goddess mahagauri has the power to fulfill all the desires of her devotees the one who worships the goddess gets relief from all the sufferings in life mahagauri has four arms her right arm is in the pose of allaying fear and right lower hand holds a trident in it she holds a tambourine in her left upper arm and the lower one is in the form of a blessing
the maillard reaction maɪˈjɑːr my yar french pronunciation ​ majaʁ is a chemical reaction between amino acids and reducing sugars that gives browned food its desirable flavor seared steaks pan fried dumplings cookies and other kinds of biscuits breads toasted marshmallows and many other foods undergo this reaction it is named after french chemist louis camille maillard who first described it in 1912 while attempting to reproduce biological protein synthesis the reaction is a form of non enzymatic browning which typically proceeds rapidly from around 140 to 165 ° c 284 to 329 ° f at higher temperatures caramelization and subsequently pyrolysis become more pronounced the reactive carbonyl group of the sugar reacts with the nucleophilic amino group of the amino acid and forms a complex mixture of poorly characterized molecules responsible for a range of odors and flavors this process is accelerated in an alkaline environment e g lye applied to darken pretzels see lye roll as the amino groups rnh 3 are deprotonated and hence have an increased nucleophilicity the type of the amino acid determines the resulting flavor this reaction is the basis of the flavoring industry at high temperatures a potential carcinogen called acrylamide can be formed in the process hundreds of different flavor compounds are created these compounds in turn break down to form yet more new flavor compounds and so on each type of food has a very distinctive set of flavor compounds that are formed during the maillard reaction it is these same compounds that flavor scientists have used over the years to make artificial flavors
in the design of experiments and analysis of variance a main effect is the effect of an independent variable on a dependent variable averaging across the levels of any other independent variables the term is frequently used in the context of factorial designs and regression models to distinguish main effects from interaction effects relative to a factorial design under an analysis of variance a main effect test will test the hypotheses expected such as h 0 the null hypothesis running a hypothesis for a main effect will test whether there is evidence of an effect of different treatments however a main effect test is nonspecific and will not allow for a localization of specific mean pairwise comparisons simple effects a main effect test will merely look at whether overall there is something about a particular factor that is making a difference in other words a test examining differences amongst the levels of a single factor averaging over the other factor and or factors main effects are essentially the overall effect of a factor
the maisonneuve fracture is a spiral fracture of the proximal third of the fibula associated with a tear of the distal tibiofibular syndesmosis and the interosseous membrane there is an associated fracture of the medial malleolus or rupture of the deep deltoid ligament this type of injury can be difficult to detect the maisonneuve fracture is similar to the galeazzi fracture in the sense that there is an important ligamentous disruption in association with the fracture the fracture is named after the surgeon jules germain françois maisonneuve
maize lethal necrosis disease mln disease mlnd corn lethal necrosis is a disease affecting maize corn chiefly in east africa it s caused by infection with two viruses mcmov maize chlorotic mottle virus and one from the potyviridae group mdmv maize dwarf mosaic virus wsmv wheat streak mosaic virus scmv sugarcane mosaic virus and the like in late 2014 it was reported that mlnd could cut kenya s maize production by as much as 30 in early march 2015 the middle of the rainy season losses were estimated at 10
majeed syndrome is an inherited skin disorder characterized by chronic recurrent multifocal osteomyelitis congenital dyserythropoietic anemia and a neutrophilic dermatosis it is classified as an autoinflammatory bone disorder the condition is found in people with two defective copies autosomal recessive inheritance of the lpin 2 gene lpin 2 encodes lipin 2 which is involved in lipid metabolism the pathogenesis of this mutation with the clinical manifestations has not been elucidated
majewski s polydactyly syndrome also known as polydactyly with neonatal chondrodystrophy type i short rib polydactyly syndrome type ii and short rib polydactyly syndrome is a lethal form of neonatal dwarfism characterized by osteochondrodysplasia skeletal abnormalities in the development of bone and cartilage with a narrow thorax polysyndactyly disproportionately short tibiae thorax dysplasia hypoplastic lungs and respiratory insufficiency associated anomalies include protruding abdomen brachydactyly peculiar faces hypoplastic epiglottis cardiovascular defects renal cysts and also genital anomalies death occurs before or at birth the disease is inherited in an autosomal recessive pattern it was characterized in 1971
majocchi s disease also known as purpura annularis telangiectodes and purpura annularis telangiectodes of majocchi is a skin condition characterized by bluish red 1 to 3 cm annular patches composed of dark red telangiectases with petechiae
major depressive disorder mdd also known as simply depression is a mental disorder characterized by at least two weeks of low mood that is present across most situations it is often accompanied by low self esteem loss of interest in normally enjoyable activities low energy and pain without a clear cause people may also occasionally have false beliefs or see or hear things that others cannot some people have periods of depression separated by years in which they are normal while others nearly always have symptoms present major depressive disorder can negatively affects a person s family work or school life sleeping or eating habits and general health between 2 7 of adults with major depression die by suicide and up to 60 of people who die by suicide had depression or another mood disorder the cause is believed to be a combination of genetic environmental and psychological factors risk factors include a family history of the condition major life changes certain medications chronic health problems and substance abuse about 40 of the risk appears to be related to genetics the diagnosis of major depressive disorder is based on the person s reported experiences and a mental status examination there is no laboratory test for major depression testing however may be done to rule out physical conditions that can cause similar symptoms major depression should be differentiated from sadness which is a normal part of life and is less severe the united states preventive services task force uspstf recommends screening for depression among those over the age 12 while a prior cochrane review found insufficient evidence for screening typically people are treated with counselling and antidepressant medication medication appears to be effective but the effect may only be significant in the most severely depressed it is unclear whether medications affect the risk of suicide types of counselling used include cognitive behavioral therapy cbt and interpersonal therapy if other measures are not effective electroconvulsive therapy ect may be tried hospitalization may be necessary in cases with a risk of harm to self and may occasionally occur against a person s wishes major depressive disorder affected approximately 253 million 3 6 of people in 2013 the percentage of people who are affected at one point in their life varies from 7 in japan to 21 in france lifetime rates are higher in the developed world 15 compared to the developing world 11 it causes the second most years lived with disability after low back pain the most common time of onset is in a person in their 20 s and 30 s females are affected about twice as often as males the american psychiatric association added major depressive disorder to the diagnostic and statistical manual of mental disorders dsm iii in 1980 it was a split of the previous depressive neurosis in the dsm ii which also encompassed the conditions now known as dysthymia and adjustment disorder with depressed mood those currently or previously affected may be stigmatized
a major depressive episode is a period characterized by the symptoms of major depressive disorder primarily depressed mood for two weeks or more and a loss of interest or pleasure in everyday activities accompanied by other symptoms such as feelings of emptiness hopelessness anxiety worthlessness guilt and or irritability changes in appetite problems concentrating remembering details or making decisions and thoughts of or attempts at suicide insomnia or hypersomnia aches pains or digestive problems that are resistant to treatment may also be present the description has been formalised in psychiatric diagnostic criteria such as the dsm 5 and icd 10 significant emotional pain and economic costs are associated with depression in the united states and canada the costs associated with major depression are comparable to those related to heart disease diabetes and back problems and are greater than the costs of hypertension according to the nordic journal of psychiatry there is a direct correlation between major depressive episode and unemployment treatments for a major depressive episode include exercise psychotherapy and antidepressants although in more serious cases hospitalization or intensive outpatient treatment may be required there are many theories as to how depression occurs one interpretation is that neurotransmitters in the brain are out of balance and this results in feelings of worthlessness and despair magnetic resonance imaging shows that brains of people who have depression look different than the brains of people not exhibiting signs of depression a family history of depression increases the chance of being diagnosed
major trauma is any injury that has the potential to cause prolonged disability or death there are many causes of major trauma blunt and penetrating including falls motor vehicle collisions and stabbing and gunshot wounds depending on the severity of injury quick management and transport to an appropriate medical facility called a trauma center may be necessary to prevent loss of life or limb the initial assessment involves a physical evaluation and can also include the use of imaging tools to accurately determine a type of injury and to formulate a course of treatment various classification scales exist for use with trauma to determine the severity of injuries which is used to determine the resources used and for statistical collection the initial assessment is critical in determining the extent of injuries and what will be needed to manage an injury and treating immediate life threats in 2002 unintentional and intentional injuries were the fifth and seventh leading causes of deaths worldwide accounting for 6 23 and 2 84 of all deaths for research purposes the definition is often based on an injury severity score iss of greater than 15
the majority problem or density classification task is the problem of finding one dimensional cellular automaton rules that accurately perform majority voting using local transition rules cells cannot know the total count of all the ones in system in order to count the number of ones or by symmetry the number of zeros the system requires a logarithmic number of bits in the total size of the system it also requires the system send messages over a distance linear in the size of the system and for the system to recognize a non regular language thus this problem is an important test case in measuring the computational power of cellular automaton systems
a makeover is changing one s appearance often using cosmetics and hair styling makeovers can range from something as simple as a new haircut to the use of cosmetic surgery to the extreme of the implantation of dental veneers eye color changing contact lenses and the use of appearance altering gastric bypass surgeries providing massive permanent fat loss in obese persons and the associated plastic surgeries such as abdominoplasty to eliminate the resulting loose hanging skin folds the panniculus a makeunder is based on the opposite principle removing artificial enhancements to a person s appearance to give a more natural look
the theatrical term entrance is the appearance of a character on screen or stage the term making an entrance commonly refers to entrances that are particularly prominent or attention grabbing some theatrical entrances mark the first appearance of a character others show a character entering a scene for the first time
mal de debarquement or mal de débarquement syndrome mdds or common name disembarkment syndrome is a rare neurological condition usually occurring after a cruise aircraft flight or other sustained motion event the phrase mal de débarquement is french for sickness from disembarkation mdds is typically diagnosed by a neurologist or an ear nose throat specialist when a person reports a persistent rocking swaying or bobbing feeling though they are not necessarily rocking this usually follows a cruise or other motion experience because most vestibule testing proves to be negative doctors may be baffled as they attempt to diagnose this rare neurological syndrome a major diagnostic indicator is that most patients feel better while driving or riding in a car or while in passive motion the syndrome has recently received increased attention due to the number of people presenting with the condition and more scientific research has commenced now for a number of years to determine what triggers mdds and how to cure it
mal morando is a cutaneous condition caused by onchocerciasis characterized by inflammation that is accompanied by hyperpigmentation
malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal gi tract impairment can be of single or multiple nutrients depending on the abnormality this may lead to malnutrition and a variety of anaemias normally the human gastrointestinal tract digests and absorbs dietary nutrients with remarkable efficiency a typical western diet ingested by an adult includes approximately 100 g of fat 400 g of carbohydrate 100 g of protein 2 l of fluid and the required sodium potassium chloride calcium vitamins and other elements salivary gastric intestinal hepatic and pancreatic secretions add an additional 7 – 8 l of protein lipid and electrolyte containing fluid to intestinal contents this massive load is reduced by the small and large intestines to less than 200 g of stool that contains less than 8 g of fat 1 – 2 g of nitrogen and less than 20 mmol each of na k cl – hco 3 – ca 2 or mg 2 if there is impairment of any of the many steps involved in the complex process of nutrient digestion and absorption intestinal malabsorption may ensue if the abnormality involves a single step in the absorptive process as in primary lactase deficiency or if the disease process is limited to the very proximal small intestine selective malabsorption of only a single nutrient may occur however generalized malabsorption of multiple dietary nutrients develops when the disease process is extensive thus disturbing several digestive and absorptive processes as occurs in coeliac disease with extensive involvement of the small intestine
a maladaptation ˌmælædæpˈteɪʃən is a trait that is or has become more harmful than helpful in contrast with an adaptation which is more helpful than harmful all organisms from bacteria to humans display maladaptive and adaptive traits in animals including humans adaptive behaviors contrast with maladaptive ones like adaptation maladaptation may be viewed as occurring over geological time or within the lifetime of one individual or a group it can also signify an adaptation that whilst reasonable at the time has become less and less suitable and more of a problem or hindrance in its own right as time goes on this is because it is possible for an adaptation to be poorly selected or become less appropriate or even become on balance more of a dysfunction than a positive adaptation over time note that the concept of maladaptation as initially discussed in a late 19 th century context is based on a flawed view of evolutionary theory it was believed that an inherent tendency for an organism s adaptations to degenerate would translate into maladaptations and soon become crippling if not weeded out see also eugenics in reality the advantages conferred by any one adaptation are rarely decisive for survival on its own but rather balanced against other synergistic and antagonistic adaptations which consequently cannot change without affecting others in other words it is usually impossible to gain an advantageous adaptation without incurring maladaptations consider a seemingly trivial example it is apparently extremely hard for an animal to evolve the ability to breathe well in air and in water better adapting to one means being less able to do the other
malakoplakia or malacoplakia from greek malako soft plako plaque is a rare inflammatory condition which makes its presence known as a papule plaque or ulceration that usually affects the genitourinary tract however it may also be associated with other bodily organs it was initially described in the early 20 th century as soft yellowish plaques found on the mucosa of the urinary bladder microscopically it is characterized by the presence of foamy histiocytes with basophilic inclusions called michaelis – gutmann bodies it usually involves gram negative bacteria
malaria is a mosquito borne infectious disease affecting humans and other animals caused by parasitic protozoans a group of single celled microorganisms belonging to the plasmodium type malaria causes symptoms that typically include fever fatigue vomiting and headaches in severe cases it can cause yellow skin seizures coma or death symptoms usually begin ten to fifteen days after being bitten if not properly treated people may have recurrences of the disease months later in those who have recently survived an infection reinfection usually causes milder symptoms this partial resistance disappears over months to years if the person has no continuing exposure to malaria the disease is most commonly transmitted by an infected female anopheles mosquito the mosquito bite introduces the parasites from the mosquito s saliva into a person s blood the parasites travel to the liver where they mature and reproduce five species of plasmodium can infect and be spread by humans most deaths are caused by p falciparum because p vivax p ovale and p malariae generally cause a milder form of malaria the species p knowlesi rarely causes disease in humans malaria is typically diagnosed by the microscopic examination of blood using blood films or with antigen based rapid diagnostic tests methods that use the polymerase chain reaction to detect the parasite s dna have been developed but are not widely used in areas where malaria is common due to their cost and complexity the risk of disease can be reduced by preventing mosquito bites through the use of mosquito nets and insect repellents or with mosquito control measures such as spraying insecticides and draining standing water several medications are available to prevent malaria in travellers to areas where the disease is common occasional doses of the medication sulfadoxine pyrimethamine are recommended in infants and after the first trimester of pregnancy in areas with high rates of malaria despite a need no effective vaccine exists although efforts to develop one are ongoing the recommended treatment for malaria is a combination of antimalarial medications that includes an artemisinin the second medication may be either mefloquine lumefantrine or sulfadoxine pyrimethamine quinine along with doxycycline may be used if an artemisinin is not available it is recommended that in areas where the disease is common malaria is confirmed if possible before treatment is started due to concerns of increasing drug resistance resistance among the parasites has developed to several antimalarial medications for example chloroquine resistant p falciparum has spread to most malarial areas and resistance to artemisinin has become a problem in some parts of southeast asia the disease is widespread in the tropical and subtropical regions that exist in a broad band around the equator this includes much of sub saharan africa asia and latin america in 2015 there were 214 million cases of malaria worldwide resulting in an estimated 438 000 deaths 90 of which occurred in africa rates of disease have decreased from 2000 to 2015 by 37 but increased from 2014 during which there were 198 million cases malaria is commonly associated with poverty and has a major negative effect on economic development in africa it is estimated to result in losses of us 12 billion a year due to increased healthcare costs lost ability to work and negative effects on tourism
malaysian contemporary music or art music notated music is an artistic phenomenon within malaysia that has its roots in the 1980 s with pioneer composers like valerie ross however little information about that period exists in written sources the genre gained visibility and momentum only in the new millennium due to the internet phenomenon and in 2002 in particular when the malaysian philharmonic orchestra mpo programmed several works by malaysian composers namely chong kee yong s echoed dream 2002 sunetra fernando s wayang 2002 and tazul izan tajuddin s sebuah tenunan iii 2003 they represent the first local commissions by a professional symphony orchestra in the country interest in orchestral music by malaysian composers grew and when the orchestra held its first forum for malaysian composers in 2003 the event was a triumph for the local music scene
male accessory gland infection magi also known as male accessory gland inflammation is a condition with signs of inflammation involving one or more sites in the male genital tract diagnosis is made according to parameters defined by the world health organisation and it is particularly made in relation to infectious or inflammatory causes of male infertility although it is usually caused by infection spreading from the urethra non infectious causes also exist
male breast cancer male breast neoplasm is a rare cancer in males that originates from the breast many males with breast cancer have inherited a brca mutation but there are other causes including alcohol abuse and exposure to certain hormones and ionizing radiation as it presents a similar pathology as female breast cancer assessment and treatment relies on experiences and guidelines that have been developed in female patients the optimal treatment is currently not known
a male genital disease is a condition that affects the male reproductive system an example is orchitis
in the nineteenth and early twentieth century female hysteria was a common psychiatric diagnosis made primarily in women the existence and nature of a purported male hysteria hysteria masculina was a debated topic around the turn of the century the notion of male hysteria was initially connected to the post traumatic disorder known as railway spine later it became associated with war neurosis
male infertility refers to a male s inability to cause pregnancy in a fertile female in humans it accounts for 40 50 of infertility it affects approximately 7 of all men male infertility is commonly due to deficiencies in the semen and semen quality is used as a surrogate measure of male fecundity
a malformative syndrome or malformation syndrome is a recognizable pattern of congenital anomalies that are known or thought to be causally related viith international congress on human genetics
a malgaigne fracture is vertical pelvic fracture with bilateral sacroiliac dislocation and fracture of the pubic rami it is named for joseph françois malgaigne
a malignant acrospiroma also known as hidradenocarcinoma and spiradenocarcinoma is a sweat gland carcinoma of the hand which may recur locally in 50 of patients after excision with distant metastases occurring in 60 of patients
malignant ectomesenchymoma is a rare fast growing tumor of the nervous system or soft tissue that occurs in children and young adults malignant ectomesenchymomas may form in the head and neck abdomen perineum scrotum or limbs also called ectomesenchymoma
malignant fibrous cytoma is a soft tissue sarcoma that usually occurs in the limbs most commonly the legs and may also occur in the abdomen also called malignant fibrous histiocytoma
malignant histiocytosis also known as histiocytic medullary reticulosis is a rare hereditary disease found in the bernese mountain dog and humans characterized by histiocytic infiltration of the lungs and lymph nodes the liver spleen and central nervous system can also be affected histiocytes are a component of the immune system that proliferate abnormally in this disease in addition to its importance in veterinary medicine the condition is also important in human pathology
malignant hyperthermia mh or malignant hyperpyrexia is a rare life threatening condition that is usually triggered by exposure to certain drugs used for general anesthesia — specifically the volatile anesthetic agents and succinylcholine a neuromuscular blocking agent in susceptible individuals these drugs can induce a drastic and uncontrolled increase in oxidative metabolism in skeletal muscle which overwhelms the body s capacity to supply oxygen remove carbon dioxide and regulate body temperature eventually leading to circulatory collapse and death if not immediately treated susceptibility to mh is often inherited as an autosomal dominant disorder for which there are at least 6 genetic loci of interest most prominently the ryanodine receptor gene ryr 1 mh susceptibility is phenotypically and genetically related to central core disease ccd an autosomal dominant disorder characterized both by mh signs and myopathy mh is usually revealed upon or shortly after exposure to certain general anesthetic agents there is no simple straightforward test to diagnose the condition treatment with dantrolene and other drugs is usually initiated when mh is strongly suspected dantrolene and the avoidance of triggering agents in susceptible people have markedly reduced the mortality from this condition
malignant meningioma is a rare fast growing tumor that forms in one of the inner layers of the meninges thin layers of tissue that cover and protect the brain and spinal cord malignant meningioma often spreads to other areas of the body the world health organization classification system defines both grade ii and grade iii meningiomas as malignant historically histological subtypes have also been used in classification including clear cell who grade ii chordoid who grade ii rhabdoid who grade iii and papillary who grade iii benign or low grade meningiomas who grade i include meningothelial fibrous transitional psammomatous angiomatous microcystic secretory lymphoplasmacyte rich and metaplastic
a malignant mixed tumor also known as a malignant chondroid syringoma is a cutaneous condition characterized by a tumor that favors the trunk and extremities
malignant narcissism is a psychological syndrome comprising an extreme mix of narcissism antisocial personality disorder aggression and sadism often grandiose and always ready to raise hostility levels the malignant narcissist undermines organizations in which they are involved and dehumanizes the people with whom they associate malignant narcissism is a hypothetical experimental diagnostic category narcissistic personality disorder is found in the diagnostic and statistical manual of mental disorders dsm iv tr while malignant narcissism is not as a hypothetical syndrome malignant narcissism could include aspects of narcissistic personality disorder as well as paranoia the importance of malignant narcissism and of projection as a defense mechanism has been confirmed in paranoia as well as the patient s vulnerability to malignant narcissistic regression
a malignant peripheral nerve sheath tumor mpnst also known as malignant schwannoma neurofibrosarcoma and neurosarcoma is a form of cancer of the connective tissue surrounding nerves given its origin and behavior it is classified as a sarcoma about half the cases are diagnosed in people with neurofibromatosis the lifetime risk for an mpnst in patients with neurofibromatosis type 1 is 8 13 mpnst with rhabdomyoblastomatous component are called malignant triton tumors the first line treatment is surgical resection with wide margins chemotherapy e g high dose doxorubicin and often radiotherapy are done as adjuvant and or neoadjuvant treatment
malignant pilomatricoma also known as a pilomatrical carcinoma and pilomatrix carcinoma is a cutaneous condition characterized by a locally aggressive tumor composed of hair matrix cells
malignant pleural effusion is a condition in which cancer causes an abnormal amount of fluid to collect between the thin layers of tissue pleura lining the outside of the lung and the wall of the chest cavity lung cancer and breast cancer account for about 50 65 of malignant pleural effusions other common causes include pleural mesothelioma and lymphoma
malignant rhabdoid tumour mrt is a very aggressive form of tumour originally described as a variant of wilms tumour which is primarily a kidney tumour that occurs mainly in children mrt was first described as a variant of wilms tumour of the kidney in 1978 mrts are a rare and highly malignant childhood neoplasm later rhabdoid tumours outside the kidney were reported in many tissues including the liver soft tissue and the central nervous system several cases of primary intracranial mrt have been reported since its recognition as a separate entity in 1978 the term rhabdoid was used due to its similarity with rhabdomyosarcoma under the light microscope the exact pathogenesis of mrt is unknown the cerebellum is the most common location for primary intracerebral mrt i e at rt biggs et al were first to report a primary intracranial mrt around 1987 although the cell of origin is not known cytogenetic studies have suggested a common genetic basis for rhabdoid tumours regardless of location with abnormalities in chromosome 22 commonly occurring
malingering is fabricating or exaggerating the symptoms of mental or physical disorders for a variety of secondary gain motives which may include financial compensation often tied to fraud avoiding school work or military service obtaining drugs getting lighter criminal sentences or simply to attract attention or sympathy malingering is different from somatization disorder and factitious disorder failure to detect actual cases of malingering imposes a substantial economic burden on the health care system and false attribution of malingering imposes a substantial burden of suffering on a significant proportion of the patient population according to the texas department of insurance fraud that includes malingering costs the u s insurance industry approximately 150 billion each year
posttraumatic stress disorder ptsd is an anxiety disorder that may develop after an individual experiences a traumatic event in the united states the social security administration and the department of veterans affairs each offer disability compensation programs that provide benefits for qualified individuals with mental disorders including ptsd because of the substantial benefits available to individuals with a confirmed ptsd diagnosis which causes occupational impairment the distinct possibility of type i errors false positive results exists some of which are due to malingering of ptsd
mallet guy sign is a medical sign to detect signs of pancreatitis it is named after pierre mallet guy
in medicine mallet finger also baseball finger dropped finger dolphin finger virgin finger hannan finger plf finger and more generally extensor tendon injury is an injury of the extensor digitorum tendon of the fingers at the distal interphalangeal joint dip it results from hyperflexion of the extensor digitorum tendon and usually occurs when a ball such as a softball basketball volleyball or dodgeball while being caught hits an outstretched finger and jams it creating a ruptured or stretched extensor digitorum tendon mallet finger can be caused by a blunt force on the dip patients who are diagnosed with mallet finger have an inability to extend their finger and experience pain and numbness depending on how severe the injury is the patient can be prescribed medication in order to prevent infection also most mallet finger injuries can be treated without surgery once a patient has been struck with mallet finger ice should be applied immediately and the patient ’ s arm should be elevated above the heart in order to reduce blood circulation to the fingers this is because this reduces inflammation which causes further damage the patient should be seen by a doctor within a week after the injury treatment options include surgery or putting the finger in a mallet splint for 6 to 8 weeks or extension block k wire for 4 weeks the splint allows the tendon to return to normal length if the finger is bent during these weeks the healing process must start all over again surgery is used to reattach the tendon and is usually performed within a week of the injury patients that present with mallet finger will have pain at the dip joint and will be unable to extend the joint it should be determined via radiograph if the extensor digitorum tendon has avulsed from the phalanx which will require surgical intervention to reattach the tendon and should be done within 10 days of the injury surgical treatment is used when the mallet finger presents as an open injury or if the bony mallet involves more than 30 of the articular surface of the joint if passive extension cannot be achieved surgery will put the finger in a neutral position and drill a wire through the dip to the pip forcing immobilization and eliminating patient compliance for re injury x ray showing fracture at the insertion of the extensor tendon a mallet finger without an associated fracture an example of a splint for mallet finger lateral view a splint for mallet finger
mallory – weiss syndrome or gastro esophageal laceration syndrome refers to bleeding from a laceration in the mucosa at the junction of the stomach and esophagus this is usually caused by severe vomiting because of alcoholism or bulimia but can be caused by any conditions which causes violent vomiting and retching such as food poisoning the syndrome presents with painful hematemesis the laceration is sometimes referred to as a mallory weiss tear
the malmquist bias is an effect in observational astronomy which leads to the preferential detection of intrinsically bright objects it was first described in 1922 by swedish astronomer gunnar malmquist 1893 – 1982 who then greatly elaborated upon this work in 1925 in statistics this bias is referred to as a selection bias and affects the survey results in a brightness limited survey where stars below a certain apparent brightness are not included since observed stars and galaxies appear dimmer when farther away the brightness that is measured will fall off with distance until their brightness falls below the observational threshold objects which are more luminous or intrinsically brighter can be observed at a greater distance creating a false trend of increasing intrinsic brightness and other related quantities with distance this effect has led to many spurious claims in the field of astronomy properly correcting for these effects has become an area of great focus
malnutrition or malnourishment is a condition that results from eating a diet in which nutrients are either not enough or are too much such that the diet causes health problems it may involve calories protein carbohydrates vitamins or minerals not enough nutrients is called undernutrition or undernourishment while too much is called overnutrition malnutrition is often used specifically to refer to undernutrition where there is not enough calories protein or micronutrients if undernutrition occurs during pregnancy or before two years of age it may result in permanent problems with physical and mental development extreme undernourishment known as starvation may have symptoms that include a short height thin body very poor energy levels and swollen legs and abdomen people also often get infections and are frequently cold the symptoms of micronutrient deficiencies depend on the micronutrient that is lacking undernourishment is most often due to not enough high quality food being available to eat this is often related to high food prices and poverty a lack of breastfeeding may contribute as may a number of infectious diseases such as gastroenteritis pneumonia malaria and measles which increase nutrient requirements there are two main types of undernutrition protein energy malnutrition and dietary deficiencies protein energy malnutrition has two severe forms marasmus a lack of protein and calories and kwashiorkor a lack of just protein common micronutrient deficiencies include a lack of iron iodine and vitamin a during pregnancy due to the body s increased need deficiencies may become more common in some developing countries overnutrition in the form of obesity is beginning to present within the same communities as undernutrition other causes of malnutrition include anorexia nervosa and bariatric surgery efforts to improve nutrition are some of the most effective forms of development aid breastfeeding can reduce rates of malnutrition and death in children and efforts to promote the practice increase the rates of breastfeeding in young children providing food in addition to breastmilk between six months and two years of age improves outcomes there is also good evidence supporting the supplementation of a number of micronutrients to women during pregnancy and among young children in the developing world to get food to people who need it most both delivering food and providing money so people can buy food within local markets are effective simply feeding students at school is insufficient management of severe malnutrition within the person s home with ready to use therapeutic foods is possible much of the time in those who have severe malnutrition complicated by other health problems treatment in a hospital setting is recommended this often involves managing low blood sugar and body temperature addressing dehydration and gradual feeding routine antibiotics are usually recommended due to the high risk of infection longer term measures include improving agricultural practices reducing poverty improving sanitation and the empowerment of women there were 793 million undernourished people in the world in 2015 13 of the total population this is a reduction of 216 million people since 1990 when 23 were undernourished in 2012 it was estimated that another billion people had a lack of vitamins and minerals in 2013 protein energy malnutrition was estimated to have resulted in 469 000 deaths — down from 510 000 deaths in 1990 other nutritional deficiencies which include iodine deficiency and iron deficiency anemia result in another 84 000 deaths in 2010 malnutrition was the cause of 1 4 of all disability adjusted life years about a third of deaths in children are believed to be due to undernutrition although the deaths are rarely labelled as such in 2010 it was estimated to have contributed to about 1 5 million deaths in women and children though some estimate the number may be greater than 3 million an additional 165 million children were estimated to have stunted growth from malnutrition in 2013 undernutrition is more common in developing countries certain groups have higher rates of undernutrition including women — in particular while pregnant or breastfeeding — children under five years of age and the elderly in the elderly undernutrition becomes more common due to physical psychological and social factors
malnutrition is a condition that affects bodily capacities of an individual including growth pregnancy lactation resistance to illness and cognitive and physical development malnutrition is commonly used in reference to undernourishment or a condition in which an individual s diet does not include sufficient calories and proteins to sustain physiological needs but it also includes overnourishment or the consumption of excess calories other terms exist to describe the specific effects of malnutrition on the body stunting refers to low height for age with reference to a population of healthy children it is an indicator of chronic malnutrition and high stunting levels are associated with poor socioeconomic conditions and a greater risk of exposure to adverse conditions such as illness wasting refers to low weight for height with reference to a population of healthy children in most cases it reflects a recent and acute weight loss associated with famine or disease unicef statistics collected between 2008 and 2012 indicate that the level of stunting in peru is 19 5 the percentage of the population that is underweight is 4 1 and 9 8 of the population is overweight the physical effects of stunting are permanent as children are unlikely to regain the loss in height and corresponding weight stunting can also have adverse effects on cognitive development school performance adult productivity and income and maternal reproductive outcome the problem of stunting is most prevalent in the highland and jungle regions of peru disproportionately affecting rural areas within these regions
malnutrition – inflammation complex syndrome abbreviated as mics and also known as malnutrition – inflammation – cachexia syndrome is a common condition in chronic disease states such as chronic kidney disease where it is also known as uremic malnutrition or protein – energy malnutrition and chronic heart failure the mics is believed to be a cause of survival paradoxes seen in these distinct patient populations also known as reverse epidemiology populations
a malocclusion is a misalignment or incorrect relation between the teeth of the two dental arches when they approach each other as the jaws close the term was coined by edward angle the father of modern orthodontics as a derivative of occlusion which refers to the manner in which opposing teeth meet mal occlusion incorrect occlusion
the malonic ester synthesis is a chemical reaction where diethyl malonate or another ester of malonic acid is alkylated at the carbon alpha directly adjacent to both carbonyl groups and then converted to a substituted acetic acid the major drawback of malonic ester synthesis is that the alkylation stage can also produce dialkylated structures this makes separation of products difficult and yields lower malonic ester synthesis
malonyl coa decarboxylase deficiency mcd or malonic aciduria is an autosomal recessive metabolic disorder caused by a genetic mutation that disrupts the activity of malonyl coa decarboxylase this enzyme breaks down malonyl coa a fatty acid precursor and a fatty acid oxidation blocker into acetyl coa and carbon dioxide
malouf syndrome also known as congestive cardiomyopathy hypergonadotropic hypogonadism syndrome is a congenital disorder that causes one or more of the following symptoms mental retardation ovarian dysgenesis congestive cardiomyopathy broad nasal base blepharoptosis and bone abnormalities and occasionally marfanoid habitus tall stature with long and thin limbs little subcutaneous fat arachnodactyly joint hyperextension narrow face small chin large testes and hypotonia this disease is named after j malouf who performed a case study on a family suffering from this disease in 1985
malpuech facial clefting syndrome also called malpuech syndrome or gypsy type facial clefting syndrome is a rare congenital syndrome it is characterized by facial clefting any type of cleft in the bones and tissues of the face including a cleft lip and palate a caudal appendage a human tail growth deficiency intellectual and developmental disability and abnormalities of the renal system kidneys and the male genitalia abnormalities of the heart and other skeletal malformations may also be present the syndrome was initially described by guilliaume malpuech and associates in 1983 it is thought to be genetically related to juberg hayward syndrome malpuech syndrome has also been considered as part of a spectrum of congenital genetic disorders associated with similar facial urogenital and skeletal anomalies termed 3 mc syndrome this proposed spectrum includes malpuech michels and mingarelli carnevale osa syndromes mutations in the collec 11 and masp 1 genes are believed to be a cause of these syndromes the incidence of malpuech syndrome is unknown the pattern of inheritance is autosomal recessive which means a defective mutated gene associated with the syndrome is located on an autosome and the syndrome occurs when two copies of this defective gene are inherited
malum perforans also known as neurotrophic ulcer and trophic ulcer is a long lasting usually painless ulcer that penetrates deep into or through the skin usually on the sole of the foot in which case it may be called malum perforans pedis it is often a complication in diabetes mellitus and other conditions affecting the nerves
a malunion is when a fractured bone doesn ’ t heal properly some ways that it shows is by having the bone being twisted shorter or bent malunions can occur by having the bones improperly aligned when immobilized having the cast taken off too early or never seeking medical treatment after the break malunions are painful and commonly produce swelling around the area possible immobilization and deterioration of the bone and tissue
most mammals are viviparous giving birth to live young however the five species of monotreme the platypuses and the echidnas lay eggs the monotremes have a sex determination system different from that of most other mammals in particular the sex chromosomes of a platypus are more like those of a chicken than those of a therian mammal the mammary glands of mammals are specialized to produce milk a liquid used by newborns as their primary source of nutrition the monotremes branched early from other mammals and do not have the nipples seen in most mammals but they do have mammary glands the young lick the milk from a mammary patch on the mother s belly viviparous mammals are in the subclass theria those living today are in the marsupial and placental infraclasses a marsupial has a short gestation period typically shorter than its estrous cycle and gives birth to an undeveloped newborn that then undergoes further development in many species this takes place within a pouch like sac the marsupium located in the front of the mother s abdomen the placentals give birth to complete and fully developed young usually after long gestation periods
mammary myofibroblastoma abbreviated mmfb aka wargotz tumor is a rare benign tumor of the breast
a mammary tumor is a tumor originating in the mammary gland it is a common finding in older female dogs and cats that are not spayed but they are found in other animals as well the mammary glands in dogs and cats are associated with their nipples and extend from the underside of the chest to the groin on both sides of the midline there are many differences between mammary tumors in animals and breast cancer in humans including tumor type malignancy and treatment options the prevalence in dogs is about three times that of women in dogs mammary tumors are the second most common tumor after skin tumors over all and the most common tumor in female dogs with a reported incidence of 3 4 multiple studies have documented that spaying female dogs when young greatly decreases their risk of developing mammary neoplasia when aged compared with female dogs left intact those spayed before puberty have 0 5 of the risk those spayed after one estrous cycle have 8 0 of the risk and dogs spayed after two estrous cycles have 26 0 of the risk of developing mammary neoplasia later in life overall unspayed female dogs have a seven times greater risk of developing mammary neoplasia than do those that are spayed while the benefit of spaying decreases with each estrous cycle some benefit has been demonstrated in female dogs even up to 9 years of age there is a much lower risk about 1 percent in male dogs and a risk in cats about half that of dogs
mammoplasia is the normal or spontaneous enlargement of the breasts mammoplasia occurs normally during puberty and pregnancy in women as well as during certain periods of the menstrual cycle when it occurs in males it is called gynecomastia and is considered to be pathological when it occurs in females and is extremely excessive it is called macromastia also known as gigantomastia or breast hypertrophy and is similarly considered to be pathological mammoplasia may be due to breast engorgement which is temporary enlargement of the breasts caused by the production and storage of breast milk in association with lactation and or galactorrhea excessive or inappropriate production of milk mastodynia breast tenderness pain frequently co occurs with mammoplasia during the luteal phase latter half of the menstrual cycle due to increased mammary blood flow and or premenstrual fluid retention caused by high circulating concentrations of estrogen and or progesterone the breasts temporarily increase in size and this is experienced by women as fullness heaviness swollenness and a tingling sensation mammoplasia can be an effect or side effect of various drugs including estrogens antiandrogens such as spironolactone cyproterone acetate bicalutamide and finasteride growth hormone and drugs that elevate prolactin levels such as d 2 receptor antagonists like antipsychotics e g risperidone metoclopramide and domperidone and certain antidepressants like selective serotonin reuptake inhibitors ssris and tricyclic antidepressants tcas the risk appears to be less with serotonin norepinephrine reuptake inhibitors snris like venlafaxine the atypical antidepressants mirtazapine and bupropion do not increase prolactin levels bupropion may actually decrease prolactin levels and hence there may be no risk with these agents other drugs that have been associated with mammoplasia include d penicillamine bucillamine neothetazone ciclosporin indinavir marijuana and cimetidine a 1997 study found an association between the ssris and mammoplasia in 23 39 of its 59 female participants studies have also found associations between ssris and galactorrhea these side effects seem to be due to hyperprolactinemia elevated prolactin levels induced by these drugs an effect that appears to be caused by serotonin mediated inhibition of tuberoinfundibular dopaminergic neurons that inhibit prolactin secretion it is noteworthy that the mammoplasia these drugs can cause has been found to be highly correlated with concomitant weight gain in the 1997 study 83 of those who experienced weight gain also experienced mammoplasia while only 30 of those who did not experience weight gain experienced mammoplasia the mammoplasia associated with ssris is reported to be reversible with drug discontinuation ssris have notably been associated with a modestly increased risk of breast cancer this is in accordance with the fact that higher prolactin levels have been associated with increased breast cancer risk in puberty induction with hormone replacement therapy hrt in hrt for trans women and in hormonal breast enhancement mammoplasia may be a desired effect
a man hour is the amount of work performed by the average worker in one hour it is used in written estimates for estimation of the total amount of uninterrupted labour required to perform a task for example researching and writing a college paper might require twenty man hours preparing a family banquet from scratch might require ten man hours man hours do not take account of the breaks that people generally require from work e g for rest eating and other bodily functions they only count pure labour managers count the man hours and add break time to estimate the amount of time a task will actually take to complete thus while one college course s written paper might require twenty man hours to carry out it almost certainly will not get done in twenty consecutive hours its progress will be interrupted by work for other courses meals sleep and other distractions
management or managing is the administration of an organization whether it be a business a not for profit organization or government body management includes the activities of setting the strategy of an organization and coordinating the efforts of its employees or volunteers to accomplish its objectives through the application of available resources such as financial natural technological and human resources the term management may also refer to the people who manage an organization management is also an academic discipline a social science whose objective is to study social organization and organizational leadership management is studied at colleges and universities some important degrees in management are the bachelor of commerce b com and master of business administration m b a and for the public sector the master of public administration mpa degree individuals who aim at becoming management researchers or professors may complete the doctor of business administration dba or the phd in business administration or management there are three levels of managers which are typically organized in a hierarchical pyramid structure senior managers such as the board of directors chief executive officer ceo or president of an organization set the strategic goals of the organization and make decisions on how the overall organization will operate senior managers provide direction to the middle managers who report to them middle managers examples of which would include branch managers regional managers and section managers provide direction to front line managers middle managers communicate the strategic goals of senior management to the front line managers lower managers such as supervisors and front line team leaders oversee the work of regular employees or volunteers in some voluntary organizations and provide direction on their work
multiple sclerosis ms is a chronic inflammatory demyelinating disease that affects the central nervous system cns several therapies for exist although there is no known cure the most common initial course of the disease is the relapsing remitting subtype which is characterized by unpredictable attacks relapses followed by periods of relative remission with no new signs of disease activity after some years many of the people who have this subtype begin to experience neurologic decline without acute relapses when this happens it is called secondary progressive multiple sclerosis other less common courses of the disease are the primary progressive decline from the beginning without attacks and the progressive relapsing steady neurologic decline and superimposed attacks different therapies are used for patients experiencing acute attacks for patients who have the relapsing remitting subtype for patients who have the progressive subtypes for patients without a diagnosis of ms who have a demyelinating event and for managing the various consequences of ms the primary aims of therapy are returning function after an attack preventing new attacks and preventing disability as with any medical treatment medications used in the management of ms may have several adverse effects and many possible therapies are still under investigation at the same time different alternative treatments are pursued by many people despite the fact that there is little supporting comparable replicated scientific study stem cell therapy is being studied this article focuses on therapies for standard ms borderline forms of ms have particular treatments that are excluded
mandibular fracture also known as fracture of the jaw is a break through the mandibular bone in about 60 of cases the break occurs in two places it may result in a decreased ability to fully open the mouth often the teeth will not feel properly aligned or there may be bleeding of the gums mandibular fractures occur most commonly among males in their 30 s mandibular fractures are typically the result of trauma this can include a fall onto the chin or a hit from the side rarely they may be due to osteonecrosis or tumors in the bone the most common area of fracture is at the condyle 36 body 21 angle 20 and symphysis 14 while a diagnosis can occasionally be made with plain x ray modern ct scans are more accurate immediate surgery is not necessarily required occasionally people may go home and follow up for surgery in the next few days a number of surgical techniques may be used including maxillomandibular fixation and open reduction internal fixation orif people are often put on antibiotics such as penicillin for a brief period of time the evidence to support this practice however is poor
mandibuloacral dysplasia is a rare autosomal recessive syndrome characterized by mandibular hypoplasia delayed cranial suture closure dysplastic clavicles abbreviated and club shaped terminal phalanges acroosteolysis atrophy of the skin of the hands and feet and typical facial changes types include
manganese mediated coupling reactions are radical coupling reactions between enolizable carbonyl compounds and unsaturated compounds initiated by a manganese iii salt typically manganese iii acetate copper ii acetate is sometimes used as a co oxidant to assist in the oxidation of intermediate radicals to carbocations
manganese mn deficiency is a plant disorder that is often confused with and occurs with iron deficiency most common in poorly drained soils also where organic matter levels are high manganese may be unavailable to plants where ph is high affected plants include onion apple peas french beans cherry and raspberry and symptoms include yellowing of leaves with smallest leaf veins remaining green to produce a ‘ chequered ’ effect the plant may seem to grow away from the problem so that youngerleaves may appear to be unaffected brown spots may appear on leaf surfaces and severely affected leaves turn brown and wither prevention can be achieved by improving soil structure do not over lime
manganism or manganese poisoning is a toxic condition resulting from chronic exposure to manganese it was first identified in 1837 by james couper
mange ˈmeɪndʒ is a class of skin diseases caused by parasitic mites since mites also infect plants birds and reptiles the term mange suggesting poor condition of the hairy coat due to the infection is sometimes reserved only for pathological mite infestation of nonhuman mammals thus mange includes mite associated skin disease in domestic animals cats and dogs in livestock such as sheep scab and in wild animals for example coyotes cougars and bears since mites belong to the arachnid subclass acari also called acarina another term for mite infestation is acariasis parasitic mites that cause mange in mammals embed themselves either in skin or hair follicles in the animal depending upon their genus sarcoptes spp burrow into skin while demodex spp live in follicles in humans these two types of mite infections which would otherwise be known as mange in furry mammals are instead known respectively as scabies and demodicosis
mangler is a software design pattern a mangler is a pattern that performs multiple operations over a series of data similar to the mapreduce function inside of bigtable and amazon s dynamo typically a mangler is fed a series of maps from which it performs its internal operations and passes its internal state data to an external filter a typical usage of the mangler pattern is during internal search operations when parsing a query from an end user the system will try and strip out a series of un needed tokens reassembling the original query into a more usable functional query an important distinction between the mangler and other patterns is the modify in place optimization pioneered by the pattern s creator this pattern was created by dr john watson during his tenure at transunion s research and development lab
manhole cover theft is the phenomenon of manhole covers being stolen usually for resale as scrap long considered to be a childish prank or simple vandalism this type of theft is often expensive to municipalities and dangerous to their residents in recent years the theft of manhole covers for financial reasons i e to sell them when scrap metal prices are high has also become more common
manifold vacuum or engine vacuum in an internal combustion engine is the difference in air pressure between the engine s intake manifold and earth s atmosphere manifold vacuum is an effect of a piston s movement on the induction stroke and the choked flow through a throttle in the intake manifold of an engine it is a measure of the amount of restriction of airflow through the engine and hence of the unused power capacity in the engine in some engines the manifold vacuum is also used as an auxiliary power source to drive engine accessories and for the crankcase ventilation system manifold vacuum should not be confused with venturi vacuum which is an effect exploited in carburetors to establish a pressure difference roughly proportional to mass airflow and to maintain a somewhat constant air fuel ratio it is also used in light airplanes to provide airflow for pneumatic gyroscopic instruments
the mannich reaction is an organic reaction which consists of an amino alkylation of an acidic proton placed next to a carbonyl functional group by formaldehyde and a primary or secondary amine or ammonia the final product is a β amino carbonyl compound also known as a mannich base reactions between aldimines and α methylene carbonyls are also considered mannich reactions because these imines form between amines and aldehydes the reaction is named after chemist carl mannich scheme 1 ammonia or an amine reacts with formaldehyde and an alpha acidic proton of a carbonyl compound to a beta amino carbonyl compound the mannich reaction is an example of nucleophilic addition of an amine to a carbonyl group followed by dehydration to the schiff base the schiff base is an electrophile which reacts in the second step in an electrophilic addition with a compound containing an acidic proton which is or had become an enol the mannich reaction is also considered a condensation reaction in the mannich reaction primary or secondary amines or ammonia are employed for the activation of formaldehyde tertiary amines lack an n – h proton to form the intermediate enamine α ch acidic compounds nucleophiles include carbonyl compounds nitriles acetylenes aliphatic nitro compounds α alkyl pyridines or imines it is also possible to use activated phenyl groups and electron rich heterocycles such as furan pyrrole and thiophene indole is a particularly active substrate the reaction provides gramine derivatives
mannosidosis is a deficiency in mannosidase an enzyme there are two types alpha mannosidosis beta mannosidosis
mansonelliasis or mansonellosis is the condition of infection by the nematode mansonella the disease exists in africa and tropical americas spread by biting midges or blackflies it is usually asymptomatic
mantle cell lymphoma mcl is a type of non hodgkin s lymphoma nhl comprising about 6 of nhl cases there are only about 15 000 patients presently in the u s the prevalence seems to be somewhat higher in men mcl is a subtype of b cell lymphoma due to cd 5 positive antigen naive pregerminal center b cell within the mantle zone that surrounds normal germinal center follicles mcl cells generally over express cyclin d 1 due to a t 11 14 chromosomal translocation in the dna specifically the translocation is at t 11 14 q 13 q 32
mantleoma is a benign neoplasm with mantle differentiation and they tend to occur on the face early neoplasms consist only of cords and columns of undifferentiated epithelial cells
in many programming languages map is the name of a higher order function that applies a given function to each element of a list returning a list of results in the same order it is often called apply to all when considered in functional form the concept of a map is not limited to lists it works for sequential containers tree like containers or even abstract containers such as futures and promises
map matching is the problem of how to match recorded geographic coordinates to a logical model of the real world typically using some form of geographic information system the most common approach is to take recorded serial location points eg from gps and relate them to edges in an existing street graph network usually in a sorted list representing the travel of a user or vehicle matching observations to a logical model in this way has applications in satellite navigation gps tracking of freight and transportation engineering map matching algorithms can be divided in real time and offline algorithms real time algorithms associate the position during the recording process to the road network offline algorithms are used after the data is recorded and are then matched to the road network real time applications can only calculate based upon the points prior to a given time as opposed to those of a whole journey but are intended to be used in live environments this brings a compromise of performance over accuracy offline applications can consider all points and so can tolerate slower performance in favour of accuracy
the maple syrup event was the objective presence of a particular scent in new york city and the response to this smell by the residents various media outlets and government agencies reports of the events are said to have begun in the fall of 2005 and continued sporadically into early 2009 new yorkers feared the sweet smell was a form of chemical warfare the scent was eventually traced to its source a frutarom industries ltd factory in northern new jersey which was processing fenugreek seeds commonly used in maple syrup substitutes this source was traced through a collaborative process between the citizens of new york city the city s 311 system the new york city office of emergency management the new york city department of environmental protection and a working group which gathered and analyzed atmospheric data the ingredient was fenugreek seeds which was commonly used in many sweets including curry powder vanilla flavoring and an imitation of pancakes
maple syrup urine disease msud also called branched chain ketoaciduria is an autosomal recessive metabolic disorder affecting branched chain amino acids it is one type of organic acidemia the condition gets its name from the distinctive sweet odor of affected infants urine particularly prior to diagnosis and during times of acute illness
marasmus is a form of severe malnutrition characterized by energy deficiency a child with marasmus looks emaciated body weight is reduced to less than 60 of the normal expected body weight for the age marasmus occurrence increases prior to age 1 whereas kwashiorkor occurrence increases after 18 months it can be distinguished from kwashiorkor in that kwashiorkor is protein deficiency with adequate energy intake whereas marasmus is inadequate energy intake in all forms including protein protein wasting in kwashiorkor may lead to edema the prognosis is better than it is for kwashiorkor but half of severely malnourished children die due to unavailability of adequate treatment the word “ marasmus ” comes from the greek μαρασμός marasmos decay
marburg virus disease mvd formerly marburg hemorrhagic fever is a severe illness of humans and non human primates caused by either of the two marburgviruses marburg virus marv and ravn virus ravv mvd is a viral hemorrhagic fever vhf and the clinical symptoms are indistinguishable from ebola virus disease evd
march fracture also known as fatigue fracture or stress fracture of metatarsal bone is the fracture of the distal third of one of the metatarsals occurring because of recurrent stress it is more common in soldiers but also occurs in hikers organists and even those like hospital doctors whose duties entail much standing march fractures most commonly occur in the second and third metatarsal bones of the foot it is a common cause of foot pain especially when people suddenly increase their activities
the march of the one hundred thousand was a manifestation of popular protest against the military dictatorship in brazil which occurred on june 26 1968 in rio de janeiro organized by the student movement and with the participation of artists intellectuals and other sectors brazilian society
marche à petits pas maʁʃ a pəti pa “ gait with little steps ” is a type of gait disorder characterised by an abnormal short stepped gait with upright stance in strict sense as opposed to generally stooping short stepped gait of parkinson s disease seen in various neurological or sometimes muscular disorders it can be further differentiated from parkinsonian gait by normal arm swing as opposed to no arm swing in parkinsonism some people refer to all forms of short stepped gaits including parkinsonian gait as marche a petit pas in a loose sense
marchiafava – bignami disease is a progressive neurological disease of alcoholism characterized by corpus callosum demyelination and necrosis and subsequent atrophy
marcus gunn phenomenon also known as marcus gunn jaw winking or trigemino oculomotor synkinesis is an autosomal dominant condition with incomplete penetrance in which nursing infants will have rhythmic upward jerking of their upper eyelid this condition is characterized as a synkinesis when two or more muscles that are independently innervated have either simultaneous or coordinated movements common physiologic examples of synkineses occur during sucking chewing or conjugate eye movements there are also several abnormal cranial nerve synkineses both acquired and congenital marcus gunn jaw winking is an example of a pathologic congenital synkinesis first described by the ophthalmologist marcus gunn in 1883 this condition presents in approximately 5 of neonates with congenital ptosis this condition has been associated with amblyopia in 54 of cases anisometropia 26 and strabismus 56
marcus gunn pupil or relative afferent pupillary defect rapd is a medical sign observed during the swinging flashlight test whereupon the patient s pupils constrict less therefore appearing to dilate when a bright light is swung from the unaffected eye to the affected eye the affected eye still senses the light and produces pupillary sphincter constriction to some degree albeit reduced the most common cause of marcus gunn pupil is a lesion of the optic nerve between the retina and the optic chiasm or severe retinal disease it is named after scottish ophthalmologist robert marcus gunn
marden – walker syndrome mws is a rare autosomal recessive congenital disorder it is characterized by blepharophimosis microcephaly micrognathia multiple joint contractures arachnodactyly camptodactyly kyphoscoliosis and delayed motor development and is often associated with cystic dysplastic kidneys dextrocardia dandy walker malformation and agenesis of corpus callosum
mare reproductive loss syndrome mrls is a syndrome consisting of equine abortions and three related nonreproductive syndromes which occur in horses of all breeds sexes and ages mrls was first observed in the u s state of kentucky in a three week period around may 5 2001 when about 20 to 30 of kentucky s pregnant mares suffered abortions a primary infectious cause was rapidly ruled out and the search began for a candidate toxin no abortifacient toxins were identified in the spring of 2001 kentucky had experienced an extraordinarily heavy infestation of eastern tent caterpillars etcs an epidemiological study showed etcs to be associated with mrls when etcs returned to kentucky in the spring of 2002 equine exposure to caterpillars was immediately shown to produce abortions research then focused on how the etcs produced the abortions reviewing the speed with which etcs produced late term abortions in 2002 experiments the nonspecific bacterial infections in the placenta fetus were assigned a primary driving role the question then became how exposure to the caterpillars produced these non specific bacterial infections of the affected placenta fetus and also the uveitis and pericarditis cases reviewing the barbed nature of etc hairs setae intestinal blood vessel penetration by barbed setal fragments was shown to introduce barbed setal fragments and associated bacterial contaminants into intestinal collecting blood vessels septic penetrating setae distribution of these materials following cardiac output would deliver these materials to all tissues in the body septic penetrating setal emboli about 15 of cardiac output goes to the late term fetus at which point the septic barbed setal fragments are positioned to penetrate placental tissues which lack an immune response bacterial proliferation therefore proceeds unchecked and the late term fetus is rapidly aborted similar events occur with the early term fetus but as a much smaller target receiving an equivalently smaller fraction of cardiac output the early term fetus is less likely to be hit by a randomly distributing setal fragment since this mrls pathogenesis model was first proposed in 2002 other caterpillar related abortion syndromes have been recognized most notably equine amnionitis and fetal loss in australia and more recently a long recognized relationship between pregnant camels eating caterpillars and abortions among the camel pastoralists in the western sahara
marfan syndrome mfs is a genetic disorder of connective tissue the degree to which people are affected varies people with marfan s tend to be tall and thin with long arms legs fingers and toes they also typically have flexible joints and scoliosis the most serious complications involve the heart and aorta with an increased risk of mitral valve prolapse and aortic aneurysm other commonly affected areas include the lungs eyes bones and the covering of the spinal cord marfan is an autosomal dominant disorder about 75 of the time the condition is inherited from a parent while 25 of the time it is a new mutation it involves a mutation to the gene that makes fibrillin which results in abnormal connective tissue diagnosis is often based on the ghent criteria there is no cure for marfan syndrome many people have a normal life expectancy with proper treatment management often includes the use of beta blockers such as propranolol or if not tolerated calcium channel blockers or ace inhibitors surgery may be required to repair the aorta or replace a heart valve it is recommended that hard exercise be avoided about one in 3 000 to 10 000 individuals have marfan syndrome it occurs equally in males and females rates are similar between races and in different regions of the world it is named after antoine marfan a french pediatrician who first described the condition in 1896
margin of safety safety margin is the difference between the intrinsic value of a stock and its market price another definition in break even analysis accounting margin of safety is how much output or sales level can fall before a business reaches its breakeven point
in finance marginal conditional stochastic dominance is a condition under which a portfolio can be improved in the eyes of all risk averse investors by incrementally moving funds out of one asset or one sub group of the portfolio s assets and into another each risk averse investor is assumed to maximize the expected value of an increasing concave von neumann morgenstern utility function all such investors prefer portfolio b over portfolio a if the portfolio return of b is second order stochastically dominant over that of a roughly speaking this means that the density function of a s return can be formed from that of b s return by pushing some of the probability mass of b s return to the left which is disliked by all increasing utility functions and then spreading out some of the density mass which is disliked by all concave utility functions if a portfolio a is marginally conditionally stochastically dominated by some incrementally different portfolio b then it is said to be inefficient in the sense that it is not the optimal portfolio for anyone note that this context of portfolio optimization is not limited to situations in which mean variance analysis applies the presence of marginal conditional stochastic dominance is sufficient but not necessary for a portfolio to be inefficient this is because marginal conditional stochastic dominance only considers incremental portfolio changes involving two sub groups of assets — one whose holdings are decreased and one whose holdings are increased it is possible for an inefficient portfolio to not be second order stochastically dominated by any such one for one shift of funds and yet to by dominated by a shift of funds involving three or more sub groups of assets
in microeconomics marginal profit is the difference between the marginal revenue and the marginal cost under the marginal approach to profit maximization to maximize profits a firm should continue to produce a good or service up to the point where marginal profit is zero
marginal zone lymphomas are a group of indolent slow growing nhl b cell lymphomas which account for approximately 12 percent of all b cell lymphomas the median age for diagnosis is 65 years old it presents primarily in sites such as stomach bowel salivary glands lung thyroid lacrimal gland conjunctiva bladder kidney skin soft tissue thymus breast ● gi tract most is the most commonly involved within gi tract stomach is involved in 85 cases there are three types of marginal zone lymphoma extranodal marginal zone lymphoma or mucosa associated lymphoid tissue malt lymphoma is the most common form of marginal zone lymphoma it occurs outside the lymph nodes this form of lymphoma makes up about nine percent of all b cell lymphomas in many cases of malt lymphoma patient has a previous medical history of inflammation or autoimmune disorders for example helicobacter pylori h pylori a microbial pathogen linked to chronic gastritis has been associated with a significant portion of patients with gastric malt lymphoma nodal marginal zone lymphoma sometimes called monocytoid b cell lymphoma occurs within the lymph nodes and accounts for about two percent of all b cell lymphomas splenic marginal zone lymphoma occurs most often in the spleen and blood it has been associated with hepatitis c this form of lymphoma makes up about one percent of all b cell lymphoma
a margules function is a function added to the raoult s law description of a liquid solution to account for deviations from ideality see also margules activity model the amended raoult s law description of the vapor pressure above the solution becomes p 1 p 1 x 1 fm 1 p 2 p 2 x 2 fm 2 the margules function has the general form fm 1 exp αx 22 βx 23 γx 23 δx 24 the function always contains the opposite mole fraction x 2 1 x 1 for a binary system the numbers of margules parameters α β γ δ varies the larger the deviations from ideality the more parameters are required the gibbs duhem relation can be used to fix the margules function for the second component once the first has been chosen the case where only one parameter α is needed is known as the regular solution model
a marian apparition is a reported supernatural appearance by the blessed virgin mary the figure is often named after the town where it is reported or on the sobriquet given to mary on the occasion of the apparition they have been interpreted in religious terms as theophanies marian apparitions sometimes are reported to recur at the same site over an extended period of time in the majority of marian apparitions only one person or a few people report having witnessed the apparition exceptions to this include zeitoun fatima and assiut where thousands claimed to have seen her over a period of time
marie unna hereditary hypotrichosis also known as marie unna hypotrichosis is an autosomal dominant condition characterized by scalp hair that is sparse or absent at birth with variable coarse wiry hair regrowth in childhood and potential loss again at puberty
marinesco – sjögren syndrome mss is a rare autosomal recessive disorder
marjolin s ulcer refers to an aggressive ulcerating squamous cell carcinoma presenting in an area of previously traumatized chronically inflamed or scarred skin they are commonly present in the context of chronic wounds including burn injuries varicose veins venous ulcers ulcers from osteomyelitis and post radiotherapy scars the term was named after french surgeon jean nicolas marjolin who first described the condition in 1828 the term was later coined by j c de costa
in some stock markets the mark twain effect is the phenomenon of stock returns in october being lower than in other months the name comes from a line in mark twain s pudd nhead wilson october this is one of the peculiarly dangerous months to speculate in stocks the others are july january september april november may march june december august and february the quotation is a sarcastic assertion that speculation in stocks is always dangerous the fact that twain specifically picks out october initially is taken as a reference to an october effect as exemplified by the 1929 1987 and 2008 stock market crashes which roughly occurred in october
the marker interface pattern is a design pattern in computer science used with languages that provide run time type information about objects it provides a means to associate metadata with a class where the language does not have explicit support for such metadata to use this pattern a class implements a marker interface also called tagging interface and methods that interact with instances of that class test for the existence of the interface whereas a typical interface specifies functionality in the form of method declarations that an implementing class must support a marker interface need not do so the mere presence of such an interface indicates specific behavior on the part of the implementing class hybrid interfaces which both act as markers and specify required methods are possible but may prove confusing if improperly used an example of the application of marker interfaces from the java programming language is the a rel nofollow class external text href docs oracle com javase 8 docs api java io serializable html serializable a interface a class implements this interface to indicate that its non transient data members can be written to an a rel nofollow class external text href docs oracle com javase 8 docs api java io objectoutputstream html objectoutputstream a the objectoutputstream private method writeobject contains a series of instanceof tests to determine writeability one of which looks for the serializable interface if any of these tests fails the method throws a notserializableexception
in economics market concentration is a function of the number of firms and their respective shares of the total production alternatively total capacity or total reserves in a market alternative terms are industry concentration and seller concentration market concentration is related to industrial concentration which concerns the distribution of production within an industry as opposed to a market in industrial organization market concentration may be used as a measure of competition theorized to be positively related to the rate of profit in the industry for example in the work of joe s bain
in financial markets market impact is the effect that a market participant has when it buys or sells an asset it is the extent to which the buying or selling moves the price against the buyer or seller i e upward when buying and downward when selling it is closely related to market liquidity in many cases liquidity and market impact are synonymous especially for large investors e g financial institutions market impact is a key consideration that needs to be considered before any decision to move money within or between financial markets if the amount of money being moved is large relative to the turnover of the asset s in question then the market impact can be several percentage points and needs to be assessed alongside other transaction costs costs of buying and selling market impact can arise because the price needs to move to tempt other investors to buy or sell assets as counterparties but also because professional investors may position themselves to profit from knowledge that a large investor or group of investors is active one way or the other some financial intermediaries have such low transaction costs that they can profit from price movements that are too small to be of relevance to the majority of investors the financial institution that is seeking to manage its market impact needs to limit the pace of its activity e g keeping its activity below one third of daily turnover so as to avoid disrupting the price
in business economics or investment market liquidity is a market s ability to purchase or sell an asset without causing drastic change in the asset s price equivalently an asset s market liquidity or simply an asset s liquidity describes the asset s ability to sell quickly without having to reduce its price to a significant degree liquidity is about how big the trade off is between the speed of the sale and the price it can be sold for in a liquid market the trade off is mild selling quickly will not reduce the price much in a relatively illiquid market selling it quickly will require cutting its price by some amount money or cash is the most liquid asset because it can be sold for goods and services instantly with no loss of value there is no wait for a suitable buyer of the cash there is no trade off between speed and value it can be used immediately to perform economic actions like buying selling or paying debt meeting immediate wants and needs if an asset is moderately or very liquid it has moderate or high liquidity in an alternative definition liquidity can mean the amount of cash and cash equivalents if a business has moderate liquidity it has a moderate amount of very liquid assets if a business has sufficient liquidity it has a sufficient amount of very liquid assets and the ability to meet its payment obligations an act of exchanging a less liquid asset for a more liquid asset is called liquidation often liquidation is trading the less liquid asset for cash also known as selling it an asset s liquidity can change for the same asset its liquidity can change through time or between different markets such as in different countries the change in the asset s liquidity is just based on the market liquidity for the asset at the particular time or in the particular country etc the liquidity of a product can be measured as how often it is bought and sold liquidity is defined formally in many accounting regimes and has in recent years been more strictly defined for instance the us federal reserve intends to apply quantitative liquidity requirements based on basel iii liquidity rules as of fiscal 2012 bank directors will also be required to know of and approve major liquidity risks personally other rules require diversifying counterparty risk and portfolio stress testing against extreme scenarios which tend to identify unusual market liquidity conditions and avoid investments that are particularly vulnerable to sudden liquidity shifts
in economics and particularly in industrial organization market power is the ability of a firm to profitably raise the market price of a good or service over marginal cost in perfectly competitive markets market participants have no market power a firm with total market power can raise prices without losing any customers to competitors market participants that have market power are therefore sometimes referred to as price makers or price setters while those without are sometimes called price takers significant market power occurs when prices exceed marginal cost and long run average cost so the firm makes economic profits a firm with market power has the ability to individually affect either the total quantity or the prevailing price in the market price makers face a downward sloping demand curve such that price increases lead to a lower quantity demanded the decrease in supply as a result of the exercise of market power creates an economic deadweight loss which is often viewed as socially undesirable as a result many countries have anti trust or other legislation intended to limit the ability of firms to accrue market power such legislation often regulates mergers and sometimes introduces a judicial power to compel divestiture a firm usually has market power by virtue of controlling a large portion of the market in extreme cases — monopoly and monopsony — the firm controls the entire market however market size alone is not the only indicator of market power highly concentrated markets may be contestable if there are no barriers to entry or exit limiting the incumbent firm s ability to raise its price above competitive levels market power gives firms the ability to engage in unilateral anti competitive behavior some of the behaviours that firms with market power are accused of engaging in include predatory pricing product tying and creation of overcapacity or other barriers to entry if no individual participant in the market has significant market power then anti competitive behavior can take place only through collusion or the exercise of a group of participants collective market power the lerner index and herfindahl index may be used to measure market power
market value added mva is the difference between the current market value of a firm and the capital contributed by investors if mva is positive the firm has added value if it is negative the firm has destroyed value the amount of value added needs to be greater than the firm s investors could have achieved investing in the market portfolio adjusted for the leverage beta coefficient of the firm relative to the market
marketing exposure is the amount of funds invested in a particular type of security and or market sector or industry and usually expressed as a percentage of total portfolio holdings it is also simply known as exposure exposure is the product of a marketing strategy and once the strategy is implemented it is only a matter of time before exposure is put into action consumers recognize marketing exposure when the company creates and promotes a campaign there are three types of marketing exposure intensive selective and exclusive marketing exposure carries a risk total to the amount invested in said market if a particular business invests 25 in a sector for housing then the market exposure for this sector is 25 investors are warned not to invest vast amounts in one particular sector due to the exposure results may vary between gains and losses depending on outcome of specific market strategies being diverse in sectors are advised for lowering the risk factor
marketing in schools is a widespread phenomenon in which schools sign contracts allowing certain businesses to conduct marketing activities in school facilities — primarily advertising for example a school might allow only one brand of soft drink to be sold in vending machines on the campus in return the soft drink company would provide compensation to the school frequently money but it may provide other compensation as well such as building new facilities or paying for school supplies the phrase usually refers to arrangements by elementary schools or high schools rather than higher education because this marketing is seen as targeting children it is very controversial one example of this is channel one news a tv show branded as educational shown in schools that shows two minutes of advertising channel one is shown in over 11 500 middle and high schools across the united states reaching 7 7 million students many find the practice objectionable some argue that it can encourage unhealthy behavior in children for example the drinking of soda or the consumption of fast food more generally some people object to the entire concept of marketing to children fearing that they are easier to influence and that this marketing is unethical or that it interferes with the values they may wish to teach their child the practice has come in for harsh criticism especially from many on the political left for example the magazine adbusters has run numerous features attacking the practice many schools defend the practice noting that it is a source of valuable revenue allowing programs that might otherwise go unfunded
a markman hearing is a pretrial hearing in a u s district court during which a judge examines evidence from all parties on the appropriate meanings of relevant key words used in a patent claim when patent infringement is alleged by a plaintiff it is also known as a claim construction hearing holding a markman hearing in patent infringement cases has been common practice since the u s supreme court in the 1996 case of markman v westview instruments inc found that the language of a patent is a matter of law for a judge to decide not a matter of fact for a jury to decide in the united states juries determine facts in many situations but judges determine matters of law markman hearings are important since the court determines patent infringement cases by the interpretation of claims a markman hearing may encourage settlement since the judge s claim construction finding can indicate a likely outcome for the patent infringement case as a whole markman hearings are before a judge and generally take place before trial a markman hearing may occur before the close of discovery along with a motion for preliminary injunction or at the end of discovery in relation to a motion for summary judgment a markman hearing may also be held after the trial begins but before jury selection the evidence considered in a markman hearing falls into two categories intrinsic and extrinsic intrinsic evidence consists of the patent documentation and any prosecution history of the patent extrinsic evidence is testimony expert opinion or other unwritten sources extrinsic evidence may not contradict intrinsic evidence
markup is the difference between the cost of a good or service and its selling price a markup is added onto the total cost incurred by the producer of a good or service in order to cover the costs of doing business and create a profit the total cost reflects the total amount of both fixed and variable expenses to produce and distribute a product markup can be expressed as a fixed amount or as a percentage of the total cost or selling price retail markup is commonly calculated as the difference between wholesale price and retail price as a percentage of wholesale other methods are also used
the markó – lam deoxygenation is an organic chemistry reaction where the hydroxy functional group in an organic compound is replaced by a hydrogen atom to give an alkyl group the markó lam reaction is a variant of the bouveault – blanc reduction and an alternative to the classical barton – mccombie deoxygenation it is named for the belgian chemists istvan marko and kevin lam the main features of the reaction are short reaction time 5 seconds to 5 minutes the use of a stable toluate derivative the use of smi 2 hmpa system or electrolysis instead of the classical and difficult to remove tributyltin hydride the marko lam deoxygenation
maroteaux – lamy syndrome also known as mucopolysaccharidosis type vi mps vi or polydystrophic dwarfism is a form of mucopolysaccharidosis caused by a deficiency in arylsulfatase b arsb it is named after pierre maroteaux 1926 and his mentor maurice emil joseph lamy 1895 1975 both french physicians
marshall syndrome is a genetic disorder of the connective tissue which can cause hearing loss the three most common areas to be affected are the eyes which are uncommonly large joints and the mouth and facial structures marshall syndrome and stickler syndrome closely resemble each other in fact they are so similar some say they are the same
marshall smith syndrome discovered in 1971 marshall graham scott boner smith is characterized by unusual accelerated skeletal maturation usually starting before birth and symptoms like conspicuous physical characteristics respiratory difficulties and mental retardation cases described in the literature show a clinical variability regarding related symptoms for instance respiratory difficulties are ranging from absent to severe difficulties
marshall – white syndrome is a skin condition that consists of bier spots associated with insomnia and tachycardia
the martin classical lectures is a function of the charles beebe martin foundation established at oberlin college in ohio charles beebe martin was a professor of classics and classical archaeology at the college from 1880 to 1925 the foundation was set up to honor his memory
martorell s ulcer is a painful ulceration of the lower leg associated with diastolic arterial hypertension it was first identified by the spanish cardiologist fernando martorell in 1945 who referred to the ulcers as hypertensive ischaemic ulcers it is characterized by single or multiple small homogeneous symmetrical lesions most commonly located on the anterolateral aspect of the lower leg the pain associated to these lesions is often disproportionate to their size the syndrome occurs predominantly in middle aged women with poorly controlled hypertension in the form of skin ulcers on the anterolateral aspect of the lower legs the lesions initially appear as small painful blisters which may or may not be associated with trauma the pathophysiology of the martorell ulcer is assumed to be related to hypertension induced arteriole changes in the dermis the pain is often disproportionate and the symptoms are not relieved by rest or elevation
masked depression md was a proposed form of atypical depression in which somatic symptoms or behavioural disturbances dominate the clinical picture and disguise the underlying affective disorder the concept is not currently supported by the mental health profession
in medicine a mass effect is the effect of a growing mass that results in secondary pathological effects by pushing on or displacing surrounding tissue in oncology the mass typically refers to a tumor for example cancer of the thyroid gland may cause symptoms due to compressions of certain structures of the head and neck pressure on the laryngeal nerves may cause voice changes narrowing of the windpipe may cause stridor pressure on the gullet may cause dysphagia and so on surgical removal or debulking is sometimes used to alleviate symptoms of the mass effect even if the underlying pathology is not curable in neurology mass effect is a general term applied to the effects exerted by any mass including for example an evolving intracerebral hemorrhage a bleeding within the skull presenting with a clinically significant hematoma the hematoma can exert a mass effect on the brain increasing intracranial pressure and potentially causing midline shift or deadly brain herniation in the past this effect held additional diagnostic importance since prior to the invention of modern tomographic soft tissue imaging utilizing mri or ct it was not possible to directly image many kinds of primary intracranial lesions therefore in those days the mass effect of these abnormalities on surrounding structures was sometimes used to indirectly infer the existence of the primary abnormalities themselves for example by using a cerebral angiography to observe the secondary vascular displacement caused by a subdural hematoma pushing on the brain or by looking for a distortion caused by a tumor on the normal outline of the ventricles as depicted on a pneumoencephalogram unfortunately these studies were often invasive and uncomfortable for patients and provided only a partial assessment of the primary condition being evaluated nowadays modern diagnostic tools exist which allow physicians to easily locate and visualize all kinds of intracranial lesions without having to rely on indirect effects to make a reliable diagnosis
the mass excess of a nuclide is the difference between its actual mass and its mass number in atomic mass units it is one of the predominant methods for tabulating nuclear mass the mass of an atomic nucleus is well approximated less than 0 1 difference for most nuclides by its mass number which indicates that most of the mass of a nucleus arises from mass of its constituent protons and neutrons thus the mass excess is an expression of the nuclear binding energy relative to the binding energy per nucleon of carbon 12 which defines the atomic mass unit if the mass excess is negative the nucleus has more binding energy than 12 c and vice versa if a nucleus has a large excess of mass compared to a nearby nuclear species it can radioactively decay releasing energy
mass fainting in tanzania is a common phenomenon of mass hysteria that is experienced by junior school girls in tanzania in september 2008 20 girls at a school in tabora started fainting while taking their final year exams the mass fainting has been linked to neurosis related to the local practice of witchcraft
in quantum field theory the mass gap is the difference in energy between the lowest energy state the vacuum and the next lowest energy state the energy of the vacuum is zero by definition and assuming that all energy states can be thought of as particles in plane waves the mass gap is the mass of the lightest particle since exact energy eigenstates are infinitely spread out and are therefore usually excluded from a formal mathematical description a stronger definition is that the mass gap is the greatest lower bound of the energy of any state which is orthogonal to the vacuum
in sociology and psychology mass hysteria also known as collective hysteria group hysteria or collective obsessional behavior is a phenomenon that transmits collective allusions of threats etc whether real or imaginary through a population in society as a result of rumors and fear memory acknowledgment in medicine the term is used to describe the spontaneous manifestation production in chemicals in the body of the same or similar hysterical physical symptoms by more than one person a common type of mass hysteria occurs when a group of people believe they are suffering from a similar disease or ailment sometimes referred to as mass psychogenic illness or epidemic hysteria
in naval tradition a mast is a non judicial punishment njp disciplinary hearing under which a commanding officer studies and disposes of cases involving those in his command if the officer conducting the proceeding is either a captain or a lower ranking officer typically a commander or lieutenant commander serving as commanding officer of a naval or coast guard vessel an aviation squadron or similar command afloat or ashore then the proceeding is referred to as a captain s mast if an admiral is overseeing the mast then the procedure is referred to as an admiral s mast or a flag mast a captain s mast or admiral s mast is a procedure whereby the commanding officer must make inquiry into the facts surrounding minor offenses allegedly committed by a member of the command afford the accused a hearing as to such offenses and dispose of such charges by dismissing the charges imposing punishment under the provisions of military law or referring the case to a court martial a captain s mast is not a trial as the term non judicial implies a conviction even if punishment is imposed an acquittal even if punishment is not imposed in the united states navy and united states coast guard these proceedings take place under the authority of article 15 of the uniform code of military justice ucmj the term mast may also refer to when a captain or commanding officer makes themself available to hear concerns complaints or requests from their crew traditionally on a naval vessel the captain would stand at the main mast of that vessel when holding mast the crew who by custom did not speak with the captain could speak to him directly at these times it could also refer to the naval punishment of tying one to a mast and lashing them with a whip in modern times a meritorious mast refers to the commanding officer taking this time to single out a member of the crew for praise and present written recognition of work well done
mast cell activation syndrome mcas also commonly referred to as mast cell activation disorder mcad is an immunological condition in which mast cells inappropriately and excessively release chemical mediators resulting in a range of chronic symptoms sometimes including anaphylaxis or near anaphylaxis attacks primary symptoms include cardiovascular dermatological gastrointestinal neurological and respiratory problems unlike mastocytosis where patients have an abnormally increased number of mast cells patients with mcas have a normal number of mast cells that do not function properly and are defined as hyperresponsive mcas is still a poorly understood condition and is a current topic of research mcas is often found in patients with ehlers – danlos syndrome eds and postural orthostatic tachycardia syndrome pots it is also found in subset groups of patients with common variable immunodeficiency cvid and lyme disease
mast cell leukemia is an extremely aggressive subtype of acute myeloid leukemia that usually occurs de novo but can rarely evolve from transformation of chronic myeloid leukemia into the more aggressive acute myeloid leukemia in a small proportion of cases acute mast cell leukemia may evolve from a more progressive form of systemic mastocytosis the diagnosis of acute mast cell leukemia by the who criteria includes the requirement for a prevalence of 20 neoplastic mast cells in marrow and 10 in blood if the mast cells represent less than 10 of blood cells the tumor is called aleukemic mast cell leukemia
mast cell sarcoma is an extremely aggressive form of sarcoma made up of neoplastic mast cells a sarcoma is a tumor made of cells from connective tissue mast cell sarcoma is an extremely rare tumor only 3 cases are reported so far prognosis is extremely poor people with a mast cell sarcoma have no skin lesions and pathology examination of the tumor shows it to be very malignant with an aggressive growth pattern mast cell sarcoma should not be confused withextracutaneous mastocytoma a rare benign mast cell tumor without destructive growth in the cases observed mast cell sarcoma terminated quickly as mast cell leukemia one of the most aggressive human cancers
the master nationality rule is a consequence of article 4 of the convention on certain questions relating to the conflict of nationality laws of 1930 this provides that a state may not afford diplomatic protection to one of its nationals against a state whose nationality such person also possesses the united kingdom home office explains in terms of practical effect it means that when a multiple citizen is in the country of one of his or her nationalities that country has the right to treat that person as if he or she were solely a citizen or national of that country this includes the right to impose military service obligations or to require an exit permit to leave the united kingdom may still make informal diplomatic representations to the authorities of another country when a british citizen is held in another country even if that person is also a citizen of that country in case of special humanitarian needs such as the intervention made by then uk foreign secretary philip hammond during the causeway bay books disappearances during the cold war era the united states signed consular agreements with certain warsaw pact countries providing that a u s citizen who entered that country with a u s passport and the appropriate visa would not be subsequently treated as a citizen of that country and hence prevented from leaving the warsaw pact countries involved notably poland wished to encourage tourism from emigrants and their descendants settled in the u s since the dissolution of the warsaw pact in 1991 many of those countries have abolished visa requirements for u s citizens thus nullifying those provisions for detailed discussion see under dual citizenship of poland the united states australia and canada have concluded similar consular agreements with the people s republic of china
masticatory muscle myositis mmm is an inflammatory disease in dogs affecting the muscles of mastication chewing it is also known as atrophic myositis or eosinophilic myositis mmm is the most common inflammatory myopathy in dogs the disease mainly affects large breed dogs german shepherd dogs and cavalier king charles spaniels may be predisposed there is a similar disease of the eye muscles found in golden retrievers symptoms of acute mmm include swelling of the jaw muscles drooling and pain on opening the mouth ophthalmic signs may include third eyelid protrusion red eyes and exophthalmos protruding eyeballs in chronic mmm there is atrophy of the jaw muscles and scarring of the masticatory muscles due to fibrosis may result in inability to open the mouth trismus the affected muscles include the temporalis masseter and pterygoid muscles the disease is usually bilateral mmm is caused by the presence of 2 m fibers in the muscles of the jaw 2 m fibers are not found elsewhere in the body but they are close in structure to proteins found on the surface of bacteria the immune system recognizes these proteins as foreign to the body and attacks them resulting in inflammation diagnosis of mmm is through either biopsy of the temporalis or masseter muscles or the 2 m antibody assay in which blood serum of the possible mmm dog is reacted with temporalis tissue of a normal dog or both false negatives by the 2 m antibody assay may be obtained if mmm is end stage with destruction of type 2 m fibers and marked fibrosis treatment is usually with corticosteroids such as prednisone often with decreasing doses for up to 4 – 6 months and in the case of trismus manual opening of the mouth under anesthesia feeding very soft or liquid food during this time is usually necessary the ultimate degree of recovery of jaw function and muscle mass will depend upon the extent of damage to the muscle tissue recurrence of mmm may occur misdiagnosis of mmm as a retroorbital abscess based on physical examination and finding of trismus leads to inappropriate treatment with antibiotics which will not impede the progress of mmm
mastitis also called mammitis is inflammation of breast or udder tissue usually due to infection staphylococcus aureus is the most common pathogen responsible but s epidermidis and streptococci are occasionally isolated as well mastitis can be classified as milk stasis non infectious or infectious inflammation and abscess it is impossible to correlate this classification with clinical symptoms in particular milk stasis non infectious and infectious inflammation can be distinguished only by leukocyte count and bacteria culturing symptoms like fever intensity of pain erythema or rapid onset of symptoms can not be used to distinguish these early stages of mastitis can present with local pain redness swelling and warmth later stages also present with systemic symptoms like fever and flu like symptoms and in rare cases an abscess can develop however it is pretty common that symptoms develop very quickly without any warning except in severe cases it is not necessary to wean a nursling because of mastitis in fact nursing is the most effective way to remove the blockage and alleviate the symptoms sudden weaning can cause or exacerbate mastitis symptoms and cause hyponatremic shock in the infant continued breastfeeding does not present any risk to the nursing infant and is very beneficial for the mother the word mastitis uses combining forms of mast itis the word mammitis mæmˈaɪtᵻs uses combining forms of mamm itis they are synonymous in modern usage and mastitis is the more commonly used synonym mastitis in dairy cattle has substantial economic importance in dairying
mastitis in dairy cattle is the persistent inflammatory reaction of the udder tissue mastitis a potentially fatal mammary gland infection is the most common disease in dairy cattle in the united states it is also the most costly to the dairy industry milk from cows suffering from mastitis has an increased somatic cell count
a mastocytoma or mast cell tumor is a type of round cell tumor consisting of mast cells it is found in humans and many animal species in human medicine it also can refer to an accumulation or nodule of mast cells that resembles a tumor mast cells originate from the bone marrow and are normally found throughout the connective tissue of the body as normal components of the immune system as they release histamine they are associated with allergic reactions mast cells also respond to tissue trauma mast cell granules contain histamine heparin platelet activating factor and other substances disseminated mastocytosis is rarely seen in young dogs and cats while mast cell tumors are usually skin tumors in older dogs and cats although not always malignant they do have the potential to be up to 25 percent of skin tumors in dogs are mast cell tumors with a similar number in cats
mastocytosis one of the mast cell diseases is a rare mast cell activation disorder of both children and adults caused by the presence of too many mast cells mastocytes and cd 34 mast cell precursors people affected by mastocytosis are susceptible to itching hives and anaphylactic shock caused by the release of histamine from mast cells the current classifications definitions and diagnostic criteria for mastocytosis are being reviewed for revision to better describe the collection of related disorders
mastoiditis is the result of an infection that extends to the air cells of the skull behind the ear specifically it is an inflammation of the mucosal lining of the mastoid antrum and mastoid air cell system inside the mastoid process the mastoid process is the portion of the temporal bone of the skull that is behind the ear which contains open air containing spaces mastoiditis is usually caused by untreated acute otitis media middle ear infection and used to be a leading cause of child mortality with the development of antibiotics however mastoiditis has become quite rare in developed countries where surgical treatment is now much less frequent and more conservative unlike former times additionally there is no evidence that the drop in antibiotic prescribing for otitis media has increased the incidence of mastoiditis untreated the infection can spread to surrounding structures including the brain causing serious complications
match fixing related to gambling is a problem in many sports according to sportradar a company that monitors the integrity of sports events on behalf of sports federations as many as 1 of the matches they monitor are likely to be fixed
matchbox sign is a psychiatric finding patients with delusional parasitosis often arrive at the doctor s office with what healthcare professionals call the matchbox sign a medical sign characterized by the patient making collections of fibers and other foreign objects supposedly retrieved from the skin the name refers to the fact that such collections can be stored in matchboxes or other similar small containers which are then presented to the patient s physician
in the mathematical fields of graph theory and combinatorics a matching polynomial sometimes called an acyclic polynomial is a generating function of the numbers of matchings of various sizes in a graph
maternal autoimmune bullous disease is a blistering skin condition that presents at birth
maternal death is defined by the world health organization who as the death of a woman while pregnant or within 42 days of termination of pregnancy irrespective of the duration and site of the pregnancy from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes the world mortality rate has declined 45 since 1990 but still every day 800 women die from pregnancy or childbirth related causes according to the united nations population fund unfpa this is equivalent to about one woman every two minutes and for every woman who dies 20 or 30 encounter complications with serious or long lasting consequences most of these deaths and injuries are entirely preventable unfpa estimated that 289 000 women died of pregnancy or childbirth related causes in 2013 these causes range from severe bleeding to obstructed labour all of which have highly effective interventions as women have gained access to family planning and skilled birth attendance with backup emergency obstetric care the global maternal mortality ratio has fallen from 380 maternal deaths per 100 000 live births in 1990 to 210 deaths per 100 000 live births in 2013 and many countries halved their maternal death rates in the last 10 years worldwide mortality rates have been decreasing in modern age high rates still exist particularly in impoverished communities with over 85 living in africa and southern asia the effect of a mother s death results in vulnerable families and their infants if they survive childbirth are more likely to die before reaching their second birthday
maternal sensitivity is a mother s ability to perceive and infer the meaning behind her infant s behavioural signals and to respond to them promptly and appropriately maternal sensitivity affects child development at all stages through life from infancy all the way to adulthood in general more sensitive mothers have healthier more socially and cognitively developed children than those who are not as sensitive also maternal sensitivity has been found to affect the person psychologically even as an adult adults who experienced high maternal sensitivity during their childhood were found to be more secure than those who experienced less sensitive mothers once the adult becomes a parent themselves their own understanding of maternal sensitivity will affect their own children s development some research suggests that adult mothers display more maternal sensitivity than adolescent mothers who may in turn have children with a lower iq and reading level than children of adult mothers there are different ways of assessing maternal sensitivity such as through the use of naturalistic observation the strange situation maternal synchrony and maternal mind mindedness there are also a number of ways of measuring maternal sensitivity in the scientific world which include ainsworth s maternal sensitivity scale amss the maternal behaviour q sort mbqs and the pederson and moran sensitivity q sort
the postpartum blues maternity blues or baby blues is a transient condition that 75 80 of mothers could experience shortly after childbirth with a wide variety of symptoms which generally involve mood lability tearfulness and some mild anxiety and depressive symptoms baby blues is not postpartum depression unless it is abnormally severe
mathematical chess problem is a mathematical problem which is formulated using a chessboard and chess pieces these problems belong to recreational mathematics the most known problems of this kind are eight queens puzzle or knight s tour problems which have connection to graph theory and combinatorics many famous mathematicians studied mathematical chess problems for example euler legendre and gauss besides finding a solution to a particular problem mathematicians are usually interested in counting the total number of possible solutions finding solutions with certain properties as well as generalization of the problems to n × n or rectangular boards
mathematical logic is a subfield of mathematics exploring the applications of formal logic to mathematics it bears close connections to metamathematics the foundations of mathematics and theoretical computer science the unifying themes in mathematical logic include the study of the expressive power of formal systems and the deductive power of formal proof systems mathematical logic is often divided into the fields of set theory model theory recursion theory and proof theory these areas share basic results on logic particularly first order logic and definability in computer science particularly in the acm classification mathematical logic encompasses additional topics not detailed in this article see logic in computer science for those since its inception mathematical logic has both contributed to and has been motivated by the study of foundations of mathematics this study began in the late 19 th century with the development of axiomatic frameworks for geometry arithmetic and analysis in the early 20 th century it was shaped by david hilbert s program to prove the consistency of foundational theories results of kurt gödel gerhard gentzen and others provided partial resolution to the program and clarified the issues involved in proving consistency work in set theory showed that almost all ordinary mathematics can be formalized in terms of sets although there are some theorems that cannot be proven in common axiom systems for set theory contemporary work in the foundations of mathematics often focuses on establishing which parts of mathematics can be formalized in particular formal systems as in reverse mathematics rather than trying to find theories in which all of mathematics can be developed
it can also be a problem referring to the nature of mathematics itself such as russell s paradox
the math – verbal achievement gap is a phenomenon first observed by richard rothstein in a brief 2002 article written in the new york times this achievement gap reveals a growing disparity in the united states between the rising national average on the math portions of the college entry sat and act exams as opposed to the flat lining verbal portions on the same tests
a mating plug also known as a copulation plug sperm plug vaginal plug sement or sphragis is gelatinous secretion used in the mating of some species it is deposited by a male into a female genital tract such as the vagina and later hardens into a plug or glues the tract together while females can expel the plugs the male ’ s sperm still gets a time advantage in getting to the egg which is often the deciding factor in fertilization the mating plug plays an important role in sperm competition and may serve as an alternative and more advantageous strategy to active mate guarding in some species such a passive mate guarding strategy may reduce selection on large male size such a strategy may be advantageous because it would allow a male to increase reproductive success by spending more time pursuing new female mates rather than active mate guarding
matrix chain multiplication or matrix chain ordering problem mcop is an optimization problem that can be solved using dynamic programming given a sequence of matrices the goal is to find the most efficient way to multiply these matrices the problem is not actually to perform the multiplications but merely to decide the sequence of the matrix multiplications involved here are many options because matrix multiplication is associative in other words no matter how the product is parenthesized the result obtained will remain the same for example for four matrices a b c and d we would have ab c d a bc d ab cd a bc d a b cd however the order in which the product is parenthesized affects the number of simple arithmetic operations needed to compute the product or the efficiency for example if a is a 10 × 30 matrix b is a 30 × 5 matrix and c is a 5 × 60 matrix then computing ab c needs 10 × 30 × 5 10 × 5 × 60 1500 3000 4500 operations whilecomputing a bc needs 30 × 5 × 60 10 × 30 × 60 9000 18000 27000 operations clearly the first method is more efficient with this information the problem statement can be refined as how to determine the optimal parenthesization of a product of n matrices checking each possible parenthesization brute force would require a run time that is exponential in the number of matrices which is very slow and impractical for large n a quicker solution to this problem can be achieved by breaking up the problem into a set of related subproblems by solving subproblems once and reusing the solutions the required run time can drastically reduced this concept is known as dynamic programming
in mathematics a matrix coefficient or matrix element is a function on a group of a special form which depends on a linear representation of the group and additional data for the case of a finite group matrix coefficients express the action of the elements of the group in the specified representation via the entries of the corresponding matrices matrix coefficients of representations of lie groups turned out to be intimately related with the theory of special functions providing a unifying approach to large parts of this theory growth properties of matrix coefficients play a key role in the classification of irreducible representations of locally compact groups in particular reductive real and p adic groups the formalism of matrix coefficients leads to a generalization of the notion of a modular form in a different direction mixing properties of certain dynamical systems are controlled by the properties of suitable matrix coefficients
in mathematics a matrix function is a function which maps a matrix to another matrix
the matroid partitioning problem is a problem arising in the mathematical study of matroids and in the design and analysis of algorithms in which the goal is to partition the elements of a matroid into as few independent sets as possible an example is the problem of computing the arboricity of an undirected graph the minimum number of forests needed to cover all of its edges matroid partitioning may be solved in polynomial time given an independence oracle for the matroid it may be generalized to show that a matroid sum is itself a matroid to provide an algorithm for computing ranks and independent sets in matroid sums and to compute the largest common independent set in the intersection of two given matroids
in sociology the matthew effect or accumulated advantage is the phenomenon where the rich get richer and the poor get poorer in both its original and typical usage it is meant metaphorically to refer to issues of fame or status but it may also be used literally to refer to cumulative advantage of economic capital the term was first coined by sociologist robert k merton in 1968 and takes its name from the parable of the talents in the biblical gospel of matthew as a result of the matilda effect harriet zuckerman is also credited by merton as the co author of the matthew effect
in psychology maturity is the ability to respond to the environment in an appropriate manner this response is generally learned rather than instinctive maturity also encompasses being aware of the correct time and place to behave and knowing when to act according to the circumstances and the culture of the society one lives in adult development and maturity theories include the purpose in life concept in which maturity emphasizes a clear comprehension of life s purpose directedness and intentionality which contributes to the feeling that life is meaningful the status of maturity is distinguished by the shift away from reliance on guardianship and the oversight of an adult in decision making acts maturity has different definitions across legal social religious political sexual emotional and intellectual contexts the age or qualities assigned for each of these contexts are tied to culturally significant indicators of independence that often vary as a result of social sentiments the concept of psychological maturity has implications across both legal and social contexts while a combination of political activism and scientific evidence continue to reshape and qualify its definition because of these factors the notion and definition of maturity and immaturity is somewhat subjective american psychologist jerome bruner proposed the purpose of the period of immaturity as being a time for experimental play without serious consequences where a young animal can spend a great deal of time observing the actions of skilled others in coordination with oversight by and activity with its mother the key to human innovation through the use of symbols and tools therefore is re interpretive imitation that is practiced perfected and varied in play through extensive exploration of the limits on one s ability to interact with the world evolutionary psychologists have also hypothesized that cognitive immaturity may serve an adaptive purpose as a protective barrier for children against their own under developed meta cognition and judgment a vulnerability that may put them in harm s way for youth today the steadily extending period of play and schooling going into the 21 st century comes as a result of the increasing complexity of our world and its technologies which too demand an increasing intricacy of skill as well as a more exhaustive set of pre requisite abilities many of the behavioral and emotional problems associated with adolescence may arise as children cope with the increased demands placed on them demands which have become increasingly abstracted from the work and expectations of adulthood
maturity onset diabetes of the young mody refers to any of several hereditary forms of diabetes caused by mutations in an autosomal dominant gene sex independent i e inherited from any of the parents disrupting insulin production mody is often referred to as monogenic diabetes to distinguish it from the more common types of diabetes especially type 1 and type 2 which involve more complex combinations of causes involving multiple genes i e polygenic and environmental factors mody 2 and mody 3 are the most common forms mody should not be confused with latent autoimmune diabetes of adults lada — a form of type 1 dm with slower progression to insulin dependence than child onset type 1 dm and which occurs later in life
mauriac syndrome is a rare complication of diabetes mellitus type 1 characterized by extreme hepatomegaly due to glycogen deposition along with growth failure and delayed puberty it occurs in children and adolescents with type 1 diabetes as a result of abnormally high blood sugar levels and the symptoms tend to rectify with attainment of normal blood sugar levels abnormally high blood sugar levels are relatively common among patients with type i diabetes but mauriac syndrome is rare suggesting that a factor affecting glycogen metabolism in addition to the high level of blood sugar is necessary to cause the syndrome a study of an adolescent boy with severe mauriac syndrome found a mutation in phkg 2 which is the catalytic subunit of glycogen phosphorylase kinase phk phk is a large enzyme complex responsible for the activation of glycogen phosphorylase the first enzyme in the pathway of glycogen metabolism expression of the mutant phkg 2 in a human liver cell line inhibited the enzyme activity of the phk complex and increased glycogen levels the mother of the boy with mauriac syndrome possessed the mutant phkg 2 but did not have diabetes or a clinically detectable enlarged liver the father of the boy had type 1 diabetes with abnormally high blood sugar levels and the size of his liver and his growth were normal the study suggests that a mutant enzyme of glycogen metabolism in addition to an abnormally high blood glucose level is necessary to cause mauriac syndrome
mautam mizo for bamboo death is a cyclic ecological phenomenon that occurs every 48 years in the northeastern indian states of mizoram and manipur which are thirty percent covered by wild bamboo forests as well as chin state in burma particularly hakha thantlang falam paletwa and matupi townships one of its stages involves a rat boom which in turn creates a widespread famine in those areas during mautam melocanna baccifera a species of bamboo flowers at one time across a wide area this event is followed invariably by a plague of black rats in what is called a rat flood this occurs as the rats multiply in response to the temporary windfall of seeds and leave the forests to forage on stored grain when the bamboo seeds are exhausted which in turn causes devastating famine famines thus caused have played a significant part in shaping the region s political history the most recent spate of flowering on the bamboo species genetically linked timetable began in may 2006 and the state government and the indian army attempted to prevent a famine
the maximum degree and diameter bounded subgraph problem maxddbs is a problem in graph theory given a connected host graph g an upper bound for the degree d and an upper bound for the diameter k we look for the largest subgraph s of g with maximum degree at most d and diameter at most k this problem is also referred to as the degree diameter subgraph problem as it contains the degree diameter problem as a special case namely by taking a sufficiently large complete graph as a host graph despite being a natural generalization of the degree diameter problem maxddbs only began to be investigated in 2011 while research in the degree diameter problem has been active since the 1960 s regarding its computational complexity the problem is np hard and not in apx i e it cannot be approximated to within a constant factor in polynomial time
maxillary hypoplasia is the name that dentists have given to the underdevelopment of the maxillary bones which produces midfacial retrusion and creates the illusion of protuberance of the lower jaw it is associated with crouzon syndrome as well as fetal alcohol syndrome
in complexity theory maximum common subgraph isomorphism mcs is an optimization problem that is known to be np hard the formal description of the problem is as follows maximum common subgraph isomorphism g 1 g 2 input two graphs g 1 and g 2 question what is the largest subgraph of g 1 isomorphic to a subgraph of g 2 the associated decision problem i e given g 1 g 2 and an integer k deciding whether g 1 contains a subgraph of at least k vertices isomorphic to a subgraph of g 2 is np complete one possible solution for this problem is to build a modular product graph in which the largest clique represents a solution for the mcs problem mcs algorithms have a long tradition in cheminformatics and pharmacophore mapping
in mathematics the maximum modulus principle in complex analysis states that if f is a holomorphic function then the modulus f cannot exhibit a true local maximum that is properly within the domain of f in other words either f is a constant function or for any point z 0 inside the domain of f there exist other points arbitrarily close to z 0 at which f takes larger values
in computational complexity theory the maximum satisfiability problem max sat is the problem of determining the maximum number of clauses of a given boolean formula in conjunctive normal form that can be made true by an assignment of truth values to the variables of the formula it is a generalization of the boolean satisfiability problem which asks whether there exists a truth assignment that makes all clauses true
maximum time in grade in a military force is the longest amount of time that an officer or enlisted man is allowed to remain in the service without being promoted if the soldier has not been promoted by the time he reaches mtig he is discharged from the service today a recruit may enter the service at 17 years old and stay in service until age 65 for a total of 48 years of service
maximum tolerable period of disruption mtpod is the maximum amount of time that an enterprise s key products or services can be unavailable or undeliverable after an event that causes disruption to operations before its stakeholders perceive unacceptable consequences
the mayer f function is an auxiliary function that often appears in the series expansion of thermodynamic quantities related to classical many particle systems
may – hegglin anomaly mha also known as dohle leukocyte inclusions with giant platelets and macrothrombocytopenia with leukocyte inclusions is a rare genetic disorder of the blood platelets that causes them to be abnormally large
in medicine may – thurner syndrome mts also known as the iliac vein compression syndrome is a rare condition in which compression of the common venous outflow tract of the left lower extremity may cause discomfort swelling pain or blood clots called deep venous thrombosis dvt in the iliofemoral vein the specific problem is compression of the left common iliac vein by the overlying right common iliac artery this leads to pooling or stasis of blood predisposing the individual to the formation of blood clots uncommon variations of mts have been described such as the right common iliac vein getting compressed by the right common iliac artery in the 21 st century the may – thurner syndrome definition has been expanded to a broader disease profile known as nonthrombotic iliac vein lesions nivl which can involve both the right and left iliac veins as well as multiple other named venous segments this syndrome frequently manifests as pain when the limb is dependent hanging down the edge of a bed chair and or significant swelling of the whole limb
may – white syndrome is a rare familial progressive myoclonus epilepsy with lipomas deafness and ataxia this syndrome is probably a familial form of mitochondrial encephalomyopathy
in geology a mazuku swahili evil wind is a pocket of carbon dioxide rich air that can be lethal to any human or animal life inside mazuku are created when carbon dioxide accumulates in pockets low to the ground co 2 is heavier than air which causes it to stay close to the ground and is also undetectable by human olfactory or visual senses in most conditions mazuku can be related to volcanic activity or to a natural disaster known as a limnic eruption in the first case noxious gases are released from the earth s crust into the atmosphere whereas in the second case the gases originate deep in a lake and boil rapidly to the surface because of their nature as sporadic and subtle events few mazuku have been recorded but there is a growing understanding of them based on historical and fossil evidence
the mccollough effect is a phenomenon of human visual perception in which colorless gratings appear colored contingent on the orientation of the gratings it is an aftereffect requiring a period of induction to produce it for example if someone alternately looks at a red horizontal grating and a green vertical grating for a few minutes a black and white horizontal grating will then look greenish and a black and white vertical grating will then look pinkish the effect is remarkable for often lasting an hour or more the effect was discovered by american psychologist celeste mccollough in 1965
mccune – albright syndrome is a complex genetic disorder affecting the bone skin and endocrine systems
the mcfadyen – stevens reaction is a chemical reaction best described as a base catalyzed thermal decomposition of acylsulfonylhydrazides to aldehydes the mcfadyen – stevens reaction dudman et al have developed an alternative hydrazide reagent
mcgillivray syndrome is a very rare syndrome which is also known as a craniosynostosis it is characterized mainly by heart defects skull and facial abnormalities and ambiguous genitalia the symptoms of this syndrome are ventricular septal defect patent ductus arteriosus small jaw undescended testes and webbed fingers beside to these symptoms there are more symptoms which is related with bone structure and misshape it was first recovered by modern understanding of craniosynostosis is referenced from the 1851 writings of virchow his understanding and descriptions of irregular calvarial growth patterns were the basis of the law of virchow the patients could be diagnosed by a misshapen skull with the shape depending on which of the cranial sutures slow or no growth of the head as the baby grows development of a raised hard ridge along affected sutures and increased pressure within the skull intracranial pressure this could be cured by various surgeries about mcgillivray mcgillivray mcgillivray syndrome is a birth defect in which one or more of the joints between the bones of your baby s skull close prematurely before your baby s brain is fully formed when your baby has craniosynostosis his or her brain can t grow in its natural shape and the head is misshapen it can affect one or more of the joints in your baby s skull in some cases craniosynostosis is associated with an underlying brain abnormality that prevents the brain from growing properly treating mcgillivray usually involves surgery to separate the fused bones if there s no underlying brain abnormality the surgery allows baby ’ s brain to grow and develop in adequate space symptoms your baby s skull has seven bones normally these bones don t fuse until around age 2 giving your baby s brain time to grow joints called cranial sutures made of strong fibrous tissue hold these bones together in the front of your baby s skull the sutures intersect in the large soft spot fontanel on the top of your baby s head normally the sutures remain flexible until the bones fuse the signs of craniosynostosis may not be noticeable at birth but they become apparent during the first few months of your baby s life the symptoms differs from types of synostosis first of all there is sagittal synostosis scaphocephaly premature fusion of the suture at the top of the head sagittal suture forces the head to grow long and narrow rather than wide scaphocephaly is the most common type of craniosynostosis the other one is called coronal synostosis anterior plagiocephaly premature fusion of a coronal suture — one of the structures that run from each ear to the sagittal suture on top of the head — may force your baby s forehead to flatten on the affected side it may also raise the eye socket and cause a deviated nose and slanted skull the bicoronal synostosis brachycephaly when both of the coronal sutures fuse prematurely your baby may have a flat elevated forehead and brow
the mcgurk effect is a perceptual phenomenon that demonstrates an interaction between hearing and vision in speech perception the illusion occurs when the auditory component of one sound is paired with the visual component of another sound leading to the perception of a third sound the visual information a person gets from seeing a person speak changes the way they hear the sound if a person is getting poor quality auditory information but good quality visual information they may be more likely to experience the mcgurk effect integration abilities for audio and visual information may also influence whether a person will experience the effect people who are better at sensory integration have been shown to be more susceptible to the effect many people are affected differently by the mcgurk effect based on many factors including brain damage and other disorders
mckusick – kaufman syndrome is a genetic condition associated with mkks the condition is named for dr robert l kaufman and victor mckusick it is sometimes known by the abbreviation mks in infancy it can be difficult to distinguish between mks and the related bardet – biedl syndrome as the more severe symptoms of the latter condition rarely materialise before adulthood
the mclafferty rearrangement is a reaction observed in mass spectrometry it is sometimes found that a molecule containing a keto group undergoes β cleavage with the gain of the γ hydrogen atom this rearrangement may take place by a radical or ionic mechanism
mcleod syndrome or mcleod phenomenon məˈklaʊd is an x linked recessive genetic disorder that may affect the blood brain peripheral nerves muscle and heart it is caused by a variety of recessively inherited mutations in the xk gene on the x chromosome the gene is responsible for producing the kx protein a secondary supportive protein for the kell antigen on the red blood cell surface
the mcmullen problem is an open problem in discrete geometry named after peter mcmullen
this reductive coupling can be viewed as involving two steps first is the formation of a pinacolate 1 2 diolate complex a step which is equivalent to the pinacol coupling reaction the second step is the deoxygenation of the pinacolate which yields the alkene this second step exploits the oxophilicity of titanium several mechanisms have been discussed for this reaction low valent titanium species induce coupling of the carbonyls by single electron transfer to the carbonyl groups the required low valent titanium species are generated via reduction usually with zinc powder this reaction is often performed in thf because it solubilizes intermediate complexes facilitates the electron transfer steps and is not reduced under the reaction conditions the nature of low valent titanium species formed is varied as the products formed by reduction of the precursor titanium halide complex will naturally depend upon both the solvent most commonly thf or dme and the reducing agent employed typically lithium aluminum hydride zinc copper couple zinc dust magnesium mercury amalgam magnesium or alkali metals bogdanovic and bolte identified the nature and mode of action of the active species in some classical mcmurry systems and an overview of proposed reaction mechanisms has been published it is of note that titanium dioxide is not generally a product of the coupling reaction although it is true that titanium dioxide is usually the eventual fate of titanium used in these reactions it is generally formed upon the aqueous workup of the reaction mixture
means ends analysis mea is a problem solving technique used commonly in artificial intelligence ai for limiting search in ai programs it is also a technique used at least since the 1950 s as a creativity tool most frequently mentioned in engineering books on design methods mea is also related to means ends chain approach used commonly in consumer behavior analysis it is also a way to clarify one s thoughts when embarking on a mathematical proof
measles is a highly contagious infection caused by the measles virus initial signs and symptoms typically include fever often greater than 40 ° c 104 0 ° f cough runny nose and inflamed eyes two or three days after the start of symptoms small white spots may form inside the mouth known as koplik s spots a red flat rash which usually starts on the face and then spreads to the rest of the body typically begins three to five days after the start of symptoms symptoms usually develop 10 – 12 days after exposure to an infected person and last 7 – 10 days complications occur in about 30 and may include diarrhea blindness inflammation of the brain and pneumonia among others rubella german measles and roseola are different diseases measles is an airborne disease which spreads easily through the coughs and sneezes of those infected it may also be spread through contact with saliva or nasal secretions nine out of ten people who are not immune and share living space with an infected person will catch it people are infectious to others from four days before to four days after the start of the rash people usually do not get the disease more than once testing for the virus in suspected cases is important for public health efforts the measles vaccine is effective at preventing the disease vaccination has resulted in a 75 decrease in deaths from measles between 2000 and 2013 with about 85 of children globally being currently vaccinated no specific treatment is available supportive care may improve outcomes this may include giving oral rehydration solution slightly sweet and salty fluids healthy food and medications to control the fever antibiotics may be used if a secondary bacterial infection such as pneumonia occurs vitamin a supplementation is also recommended in the developing world measles affects about 20 million people a year primarily in the developing areas of africa and asia it causes the most vaccine preventable deaths of any disease it resulted in about 96 000 deaths in 2013 down from 545 000 deaths in 1990 in 1980 the disease was estimated to have caused 2 6 million deaths per year most of those who are infected and who die are less than five years old the risk of death among those infected is usually 0 2 but may be up to 10 in those who have malnutrition it is not believed to affect other animals before immunization in the united states between three and four million cases occurred each year as a result of widespread vaccination the disease was eliminated from the americas in 2016
the measurement problem in quantum mechanics is the problem of how or whether wavefunction collapse occurs the inability to observe this process directly has given rise to different interpretations of quantum mechanics and poses a key set of questions that each interpretation must answer the wavefunction in quantum mechanics evolves deterministically according to the schrödinger equation as a linear superposition of different states but actual measurements always find the physical system in a definite state any future evolution is based on the state the system was discovered to be in when the measurement was made meaning that the measurement did something to the system that is not obviously a consequence of schrödinger evolution to express matters differently to paraphrase steven weinberg the schrödinger wave equation determines the wavefunction at any later time if observers and their measuring apparatus are themselves described by a deterministic wave function why can we not predict precise results for measurements but only probabilities as a general question how can one establish a correspondence between quantum and classical reality
the measurement of economic worth over time is the problem of equating past prices costs values and proportions of social production to current prices costs values and proportions of social production for a number of reasons the ability to equate any past indicator with a current indicator of worth is theoretically and practically difficult for economists historians and political economists this has led to some questioning of the idea of time series of worth having any meaning however the popular demand for measurements of social worth over time have caused the production of a number of series
urethral meatal stenosis or urethral stricture is a narrowing stenosis of the opening of the urethra at the external meatus miːˈeɪtəs thus constricting the opening through which urine leaves the body from the urinary bladder
the mebibit is a multiple of the bit a unit of information prefixed by the standards based multiplier mebi symbol mi a binary prefix meaning 220 the unit symbol of the mebibit is mibit 1 mebibit 220 bits 1048576 bits 1024 kibibits this unit is most useful for measuring ram and rom chip capacity the mebibit is closely related to the megabit which equals 106 bits 1 000 000 bits throughout the 1980 s and 1990 s video game manufacturers would sometimes report the amount of internal cartridge rom in megabits on their packaging 1 megabit equaled 128 kibibyte 8 megabits were 1 mebibyte of rom containing game instructions and data
the mebibyte is a multiple of the unit byte for digital information the binary prefix mebi means 220 therefore one mebibyte is equal to 1048576 bytes 1024 kibibytes the unit symbol for the mebibyte is mib the unit was established by the international electrotechnical commission iec in 1998 it was designed to replace the megabyte when used in the binary sense to mean 220 bytes which is incompatible with the definition of the prefix mega in the international system of units si as a multiplier of 106 the binary prefixes have been accepted by all major standards organizations and are part of the international system of quantities many linux distributions use the unit but it is not widely acknowledged within the industry or media
prior to the early 1990 s the studies on different chemical and physical variables of sonoluminescence were all conducted using multi bubble sonoluminescence mbsl this was a problem since all of the theories and bubble dynamics were based on single bubble sonoluminescence sbsl and researchers believed that the bubble oscillations of neighboring bubbles could affect each other single bubble sonoluminescence wasn t achieved until the early 1990 s and allowed the study of the effects of various parameters on a single cavitating bubble after many of the early theories were disproved the remaining plausible theories can be classified into two different processes electrical and thermal
a meckel s diverticulum a true congenital diverticulum is a slight bulge in the small intestine present at birth and a vestigial remnant of the omphalomesenteric duct also called the vitelline duct or yolk stalk it is the most common malformation of the gastrointestinal tract and is present in approximately 2 of the population with males more frequently experiencing symptoms meckel s diverticulum was first explained by fabricius hildanus in the sixteenth century and later named after johann friedrich meckel who described the embryological origin of this type of diverticulum in 1809
meckel syndrome also known as meckel – gruber syndrome gruber syndrome dysencephalia splanchnocystica is a rare lethal ciliopathic genetic disorder characterized by renal cystic dysplasia central nervous system malformations occipital encephalocele polydactyly post axial hepatic developmental defects and pulmonary hypoplasia due to oligohydramnios meckel – gruber syndrome is named for johann meckel and georg gruber
meconium aspiration syndrome mas also known as neonatal aspiration of meconium is a medical condition affecting newborn infants it occurs when meconium is present in their lungs during or before delivery meconium is the first stool of an infant composed of materials ingested during the time the infant spends in the uterus meconium is normally stored in the infant s intestines until after birth but sometimes often in response to fetal distress and hypoxia it is expelled into the amniotic fluid prior to birth or during labor if the baby then inhales the contaminated fluid respiratory problems may occur
meconium peritonitis refers to rupture of the bowel prior to birth resulting in fetal stool meconium escaping into the surrounding space peritoneum leading to inflammation peritonitis despite the bowel rupture many infants born after meconium peritonitis in utero have normal bowels and have no further issues infants with cystic fibrosis are at increased risk for meconium peritonitis
the medial epicondyle of the femur is a bony protrusion located on the medial side of the bone s distal end located above the medial condyle it bears an elevation the adductor tubercle which serves for the attachment of the superficial part or tendinous insertion of the adductor magnus this tendinous part here forms an intermuscular septum which forms the medial separation between the thigh s flexors and extensors behind it and proximal to the medial condyle is a rough impression which gives origin to the medial head of the gastrocnemius
medial medullary syndrome also known as inferior alternating syndrome hypoglossal alternating hemiplegia lower alternating hemiplegia or dejerine syndrome is a type of alternating hemiplegia characterized by a set of clinical features resulting from occlusion of the anterior spinal artery this results in the infarction of medial part of the medulla oblongata
medial inferior pontine syndrome is a condition associated with a contralateral hemiplegia medial inferior pontine syndrome has been described as equivalent to foville s syndrome
the median alveolar cyst is a rare cyst occurring in the bony alveolus between the maxillary central incisors it is distinguished from a periapical cyst by the fact that adjacent teeth are vital
in medicine the median arcuate ligament syndrome mals also known as celiac artery compression syndrome celiac axis syndrome celiac trunk compression syndrome or dunbar syndrome is a condition characterized by abdominal pain attributed to compression of the celiac artery and possibly the celiac ganglia by the median arcuate ligament the abdominal pain may be related to meals may be accompanied by weight loss and may be associated with an abdominal bruit heard by a clinician it is also called celiac artery compression syndrome the diagnosis of mals is one of exclusion as many healthy patients demonstrate some degree of celiac artery compression in the absence of symptoms consequently a diagnosis of mals is typically only entertained after more common conditions have been ruled out once suspected screening for mals can be done with ultrasonography and confirmed with computed tomography ct or magnetic resonance mr angiography treatment is generally surgical the mainstay being open division or separation of the median arcuate ligament combined with removal of the celiac ganglia the majority of patients benefit from surgical intervention poorer responses to treatment tend to occur in patients of older age those with a psychiatric condition or who use alcohol have abdominal pain unrelated to meals or who have not experienced weight loss
a median mandibular cyst is a type of cyst that occurs in the midline of the mandible thought to be created by proliferation and cystic degeneration of resting epithelial tissue that is left trapped within the substance of the bone during embryologic fusion of the two halves of the mandible along the plane of fusion later termed the symphysis menti a ture median mandibular cyst would therefore be classified as a non odontogenic fissural cyst the existence of this lesion as a unique clinical entity is controversial and some reported cases may have represented misdiagnosed odontogenic cysts which are by far the most common type of intrabony cyst occurring in the jaws it has also been suggested that the mandible develops as a bilobed proliferation of mesenchyme connected with a central isthmus therefore it is unlikely that epithelial tissue would become trapped as there is no ectoderm separating the lobes in the first instance
injuries to the arm forearm or wrist area can lead to various nerve disorders one such disorder is median nerve palsy if the median nerve is damaged the ability to abduct and oppose the thumb may be lost due to paralysis of the thenar muscles various other symptoms can occur which may be repaired through surgery and tendon transfers tendon transfers have been very successful in restoring motor function and improving functional outcomes in patients with median nerve palsy
the median palatal cyst is a rare cyst that may occur anywhere along the median palatal raphe it may produce a swelling because of infection and is treated by excision or surgical removal some investogators now believe that this cyst represents a more posterior presentation of a nasopalatine duct cyst rather than a separate cystic degeneration of epithelial rests at the line of fusion of the palatine shelves
median raphe cysts are a cutaneous condition of the penis due to developmental defects near the glans
median rhomboid glossitis mrg also known as central papillary atrophy or glossal central papillary atrophy is a condition characterized by an area of redness and loss of lingual papillae situated on the dorsum of the tongue in the midline immediately in front of the circumvallate papillae median rhomboid glossitis is thought to be created by a chronic fungal infection and usually is a type of oral candidiasis
mediastinal fibrosis most common cause is idiopathic mediastinal fibrosis less commonly histoplasmosis tuberculosis or unknown it is characterized by invasive calcified fibrosis centered on lymph nodes that block major vessels and airways in europe this disease is exceptionally rare more cases are seenin usa where the disease may often be associated with histoplasmosis
mediastinal germ cell tumors are tumors that derive from germ cell rest remnants in the mediastinum they most commonly occur in the gonad but occasionally elsewhere
mediastinal lymphadenopathy or mediastinal adenopathy is an enlargement of the mediastinal lymph nodes
the mediastinum is the cavity that separates the lungs from the rest of the chest it contains the heart esophagus trachea thymus and aorta the mediastinum has three main parts the anterior mediastinum front the middle mediastinum and the posterior mediastinum back the most common mediastinal masses are neurogenic tumors 20 of mediastinal tumors usually found in the posterior mediastinum followed by thymoma 15 20 located in the anterior mediastinum masses in the anterior portion of the mediastinum can include thymoma lymphoma pheochromocytoma germ cell tumors including teratoma thyroid tissue and parathyroid lesions masses in this area are more likely to be malignant than those in other compartments masses in the posterior portion of the mediastinum tend to be neurogenic in origin and in adults tend to be of neural sheath origin including neurilemomas and neurofibromas lung cancer typically spreads to the lymph nodes in the mediastinum
mediastinitis is inflammation of the tissues in the mid chest or mediastinum it can be either acute or chronic acute mediastinitis is usually bacterial and due to rupture of organs in the mediastinum as the infection can progress rapidly this is considered a serious condition chronic sclerosing or fibrosing mediastinitis while potentially serious is caused by a long standing inflammation of the mediastinum leading to growth of acellular collagen and fibrous tissue within the chest and around the central vessels and airways it has a different cause treatment and prognosis than acute infectious mediastinitis
in telecommunications network management a mediation function is a function that routes or acts on information passing between network elements and network operations examples of mediation functions are communications control protocol conversion data handling communications of primitives processing that includes decision making and data storage mediation functions can be shared among network elements mediation devices and network operation centers
in politics and law mediatisation pronunciation miːdiətaɪˈzeɪʃən is the loss of immediacy immediacy is the status of persons not subject to local lords but only to a higher authority directly such as the holy roman emperor in a feudal context it is the introduction of an intervening level of authority between a lord and his vassal so that the former is no longer the immediate lord of the latter but rather his lordship is mediated by another although the process had been going on since the middle ages the term mediatisation was originally applied to the reorganisation of the german states during the early 19 th century in this case many states that were immediate vassals of the holy roman emperor became instead vassals of other immediate states so that the total number of states immediately subject to the emperor decreased
a medical emergency is an acute injury or illness that poses an immediate risk to a person s life or long term health these emergencies may require assistance from another person who should ideally be suitably qualified to do so although some of these emergencies such as cardiovascular heart respiratory gastrointestinal cannot be dealt with by the victim themselves dependent on the severity of the emergency and the quality of any treatment given it may require the involvement of multiple levels of care from first aiders to emergency medical technicians and emergency physicians any response to an emergency medical situation will depend strongly on the situation the patient involved and availability of resources to help them it will also vary depending on whether the emergency occurs whilst in hospital under medical care or outside of medical care for instance in the street or alone at home
a medical error is a preventable adverse effect of care whether or not it is evident or harmful to the patient this might include an inaccurate or incomplete diagnosis or treatment of a disease injury syndrome behavior infection or other ailment globally it is estimated that 142 000 people died in 2013 from adverse effects of medical treatment this is an increase from 94 000 in 1990 however a 2016 study of the number of deaths that were a result of medical error in the u s placed the yearly death rate in the u s alone at 251 454 deaths which suggests that the 2013 global estimation may not be accurate
medical malpractice is a legal cause of action that occurs when a medical professional deviates from standards in his or her profession thereby causing injury to a patient
medical students disease also known as second year syndrome or intern s syndrome is a condition frequently reported in medical students who perceive themselves to be experiencing the symptoms of a disease that they are studying the condition is associated with the fear of contracting the disease in question some authors suggested that the condition must be referred to as nosophobia rather than hypochondriasis because the quoted studies show a very low percentage of hypochondriacal character of the condition and hence the term hypochondriasis would have ominous therapeutic and prognostic indications the reference suggests that the condition is associated with immediate preoccupation with the symptoms in question leading the student to become unduly aware of various casual psychological and physiological dysfunctions cases show little correlation with the severity of psychopathology but rather with accidental factors related to learning and experience
medically unexplained physical symptoms mups or mus are symptoms for which a treating physician or other healthcare providers have found no medical cause or whose cause remains contested in its strictest sense the term simply means that the cause for the symptoms is unknown or disputed — there is no scientific consensus typically the possibility that mups are caused by prescription drugs or other drugs is ignored however in practice most physicians and authors who use the term consider that the symptoms most likely arise from psychological causes it is estimated that between 15 and 30 of all primary care consultations are for medically unexplained symptoms a large canadian community survey revealed that the most common medically unexplained symptoms are musculoskeletal pain ear nose and throat symptoms abdominal pain and gastrointestinal symptoms fatigue and dizziness the term mups can also be used to refer to syndromes whose etiology remains contested including chronic fatigue syndrome fibromyalgia multiple chemical sensitivity and gulf war illness many patients presenting with medically unexplained symptoms also meet the diagnostic criteria for anxiety and or depression the likelihood of meeting such criteria increases with the number of unexplained symptoms reported however anxiety and depression are also very common in individuals with medically explained illnesses and again the likelihood of a person receiving one of these diagnoses increases with the number of symptoms reported consequently on the current evidence we cannot infer that anxiety or depression are causes of medically unexplained physical symptoms physical symptoms have been associated with adverse psychosocial and functional outcome across different cultures irrespective of etiology either explained or unexplained
medication induced hyperlipoproteinemia is a condition that results from the decreasing of lipoprotein lipase activity resulting in eruptive xanthomas
medication overuse headache moh also known as rebound headache usually occurs when analgesics are taken frequently to relieve headaches rebound headaches frequently occur daily can be very painful and are a common cause of chronic daily headache they typically occur in patients with an underlying headache disorder such as migraine or tension type headache that transforms over time from an episodic condition to chronic daily headache due to excessive intake of acute headache relief medications moh is a serious disabling and well characterized disorder which represents a worldwide problem and is now considered the third most prevalent type of headache population based studies report the prevalence rate of moh to be 1 to 2 in the general population but its relative frequency is much higher in secondary and tertiary care
the medieval renaissances were periods characterised by significant cultural renewal right across medieval western europe these are effectively seen as occurring in three phases the carolingian renaissance 8 th and 9 th centuries ottonian renaissance 10 th century and the renaissance of the 12 th century the term was first used by medievalists in the 19 th century by analogy with the historiographical concept of the 15 th and 16 th century italian renaissance this was notable since it marked a break with the dominant historiography of the time which saw the middle ages as dark and obscurantist the term has always been a subject of debate and criticism particularly on how widespread such renewal movements were and on the validity of comparing them with the italian renaissance
medium chain acyl coa dehydrogenase deficiency often known as mcad deficiency or mcadd is a disorder of fatty acid oxidation that impairs the body s ability to break down medium chain fatty acids into acetyl coa the disorder is characterized by hypoglycemia and sudden death without timely intervention most often brought on by periods of fasting or vomiting prior to expanded newborn screening mcadd was an underdiagnosed cause of sudden death in infants individuals who have been identified prior to the onset of symptoms have an excellent prognosis mcadd is most prevalent in individuals of northern european caucasian descent with an incidence of 1 4000 to 1 17 000 depending on the population treatment of mcadd is mainly preventative by avoiding fasting and other situations where the body relies on fatty acid oxidation to supply energy
medullary carcinoma of the breast is a type of breast cancer it is relatively circumscribed it involves infiltration by lymphocytes
medullary cystic kidney disease mckd is an autosomal dominant kidney disorder characterized by tubulointerstitial sclerosis leading to end stage renal disease because the presence of cysts is neither an early nor a typical diagnostic feature of the disease and because at least 4 different gene mutations may give rise to the condition the name autosomal dominant tubulointerstitial kidney disease adtkd has been proposed to be appended with the underlying genetic variant for a particular individual importantly if cysts are found in the medullary collecting ducts they can result in a shrunken kidney unlike that of polycystic kidney disease there are two known forms of medullary cystic kidney disease mucin 1 kidney disease 1 mkd 1 and mucin 2 kidney disease uromodulin kidney disease mkd 2 a third form of the disease occurs due to mutations in the gene encoding renin adtkd ren and has formerly been known as familial juvenile hyperuricemic nephropathy type 2
medullary sponge kidney also known as cacchi – ricci disease is a congenital disorder of the kidneys characterized by cystic dilatation of the collecting tubules in one or both kidneys individuals with medullary sponge kidney are at increased risk for kidney stones and urinary tract infection patients with msk typically pass twice as many stones per year as do other stone formers without msk while described as a benign disorder with a low morbidity rate as many as 10 of patients with msk have an increased risk of morbidity associated with frequent stones and utis while some patients report increased chronic kidney pain the source of the pain when a uti or blockage is not present is unclear at this time renal colic flank and back pain is present in 55 of patients women with msk experience more stones utis and complications than men msk was previously believed not to be hereditary but there is more evidence coming forth that may indicate otherwise
medullary thyroid cancer mtc is a form of thyroid carcinoma which originates from the parafollicular cells c cells which produce the hormone calcitonin medullary tumors are the third most common of all thyroid cancers they make up about 3 of all thyroid cancer cases approximately 25 of medullary thyroid cancer is genetic in nature caused by a mutation in the ret proto oncogene this form is classified as familial mtc when mtc occurs by itself it is termed sporadic mtc when it coexists with tumors of the parathyroid gland and medullary component of the adrenal glands pheochromocytoma it is called multiple endocrine neoplasia type 2 men 2 it was first characterized in 1959
medulloblastoma məˌdʌloʊblæˈstoʊmə is the most common type of pediatric malignant primary brain tumor cancer originating in the part of the brain that is towards the back and the bottom on the floor of the skull in the cerebellum or posterior fossa the brain is divided into two main parts the larger cerebrum on top and the smaller cerebellum below towards the back they are separated by a membrane called the tentorium tumors that originate in the cerebellum or the surrounding region below the tentorium are therefore called infratentorial historically medulloblastomas have been classified as a pnet primitive neuroectodermal tumour however it is now known that medulloblastoma is distinct from supratentorial pnet s and are no longer considered similar entities medulloblastomas are non invasive rapidly growing tumors that unlike most brain tumors spread through the cerebrospinal fluid csf and frequently metastasize to different locations along the surface of the brain and spinal cord the cumulative relative survival rate for all age groups and histology follow up was 60 52 and 32 at 5 years 10 years and 20 years respectively with children doing better than adults
medulloepithelioma is a rare primitive fast growing brain tumour thought to stem from cells of the embryonic medullary cavity tumours originating in the ciliary body of the eye are referred to as embryonal medulloepitheliomas or diktyomas a highly malignant undifferentiated primitive neuroepithelial tumour of children medulloepithelioma may contain bone cartilage skeletal muscle and tends to metastasize extracranially
meerwein reaction redirects here for other reactions named after hans meerwein see meerwein reaction disambiguation the meerwein arylation is an organic reaction involving the addition of an aryl diazonium salt arn 2 x to an electron poor alkene usually supported by a metal salt the reaction product is an alkylated arene compound the reaction is named after hans meerwein one of its inventors who first published it in 1939 meerwein arylation an electron withdrawing group ewg on the alkene makes it electron deficient and although the reaction mechanism is unclear involvement of an aryl radical is presumed after loss of nitrogen in the diazonium salt followed by a free radical addition in the primary reaction product the intermediate alkyl radical is then captured by the diazonium counterion x which is usually a halogen or a tetrafluoroborate in a subsequent step an elimination reaction liberates hx for instance hydrochloric acid and an aryl vinyl compound is formed the reaction mechanism from the arene s view ranks as a radical nucleophilic aromatic substitution in a general scope a meerwein arylation is any reaction between an aryl radical and an alkene the initial intermediate is an aryl enthenyl radical which can react with many trapping reagents such as hydrogen or halogens or with those based on nitrogen or sulfur
mees lines or aldrich – mees lines also called leukonychia striata are lines of discoloration across the nails of the fingers and toes
meesmann corneal dystrophy also stocker holt dystrophy is a type of corneal dystrophy and a keratin disease it is named for german ophthalmologist alois meesmann 1888 1969 it is sometimes called meesmann wilke syndrome after the joint contribution of meesmann and wilke
a megabias or a taphonomic megabias is a large scale pattern in the quality of the fossil record that affects paleobiologic analysis at provincial to global levels and at timescales usually exceeding ten million years it can result from major shifts in intrinsic and extrinsic properties of organisms including morphology and behaviour in relation to other organisms or shifts in the global environment which can cause secular or long term cyclic changes in preservation
the megabit is a multiple of the unit bit for digital information the prefix mega symbol m is defined in the international system of units si as a multiplier of 106 1 million and therefore 1 megabit 106 bits 1000000 bits 1000 kilobits the megabit has the unit symbol mb or mbit the megabit is closely related to the mebibit a unit multiple derived from the binary prefix mebi symbol mi of the same order of magnitude which is equal to 220 bits 1048576 bits or approximately 5 larger than the megabit despite the definitions of these new prefixes for binary based quantities of storage by international standards organizations memory semiconductor chips are still marketed using the metric prefix names to designate binary multiples using the common byte size of eight bits and the standardized metric definition of megabit and kilobyte 1 megabit is equal to 125 kilobytes kb or approximately 122 kibibytes kib the megabit is widely used when referring to data transfer rates of computer networks or telecommunications systems network transfer rates and download speeds often use the megabit as the amount transferred per time unit e g a 100 mbit s megabit per second fast ethernet connection or a 10 mbit s internet access service whereas the sizes of data units files transferred over these networks are often measured in megabytes to achieve a transfer rate of one megabyte per second one needs a network connection with a transfer rate of eight megabits per second
the megabyte is a multiple of the unit byte for digital information its recommended unit symbol is mb but sometimes mbyte is used the unit prefix mega is a multiplier of 1000000 106 in the international system of units si therefore one megabyte is one million bytes of information this definition has been incorporated into the international system of quantities however in the computer and information technology fields several other definitions are used that arose for historical reasons of convenience a common usage has been to designate one megabyte as 1048576 bytes 220 b a measurement that conveniently expresses the binary multiples inherent in digital computer memory architectures however most standards bodies have deprecated this usage in favor of a set of binary prefixes in which this measurement is designated by the unit mebibyte mib less common is a measurement that used the megabyte to mean 1000 × 1024 1024000 bytes
megacolon is an abnormal dilation of the colon also called the large intestine the dilation is often accompanied by a paralysis of the peristaltic movements of the bowel in more extreme cases the feces consolidate into hard masses inside the colon called fecalomas literally fecal tumor which can require surgery to be removed a human colon is considered abnormally enlarged if it has a diameter greater than 12 cm in the cecum it is usually less than 9 cm greater than 6 5 cm in the rectosigmoid region and greater than 8 cm for the ascending colon the transverse colon is usually less than 6 cm in diameter a megacolon can be either acute or chronic it can also be classified according to etiology
megacystis is a rare disease that is identified by an abnormally large or distended bladder
megaduodenum is a congenital or acquired dilation and elongation of the duodenum with hypertrophy of all layers that presents as a feeling of gastric fullness abdominal pain belching heartburn and nausea with vomiting sometimes of food eaten 24 hours prior
megaesophagus also known as me is a condition in humans cats dogs and horses where peristalsis fails to occur properly and the esophagus is enlarged normally when the animal s esophagus is functioning properly it acts as a muscle and pushes the food down the esophagus into the stomach however when an animal has megaesophagus the esophagus stays enlarged and does not push the food down to the stomach therefore the food fails to enter the stomach and often stays in the esophagus and is eventually regurgitated or enters the lungs through breathing or decays in the esophagus in human pathology a condition known as achalasia may predispose a person to slowly develop megaesophagus achalasia is due to the loss of ganglion cells of the myenteric plexus it occurs mostly in middle aged adults there is a marked lack of contraction within the muscles involved in peristalsis with a constant contraction of the lower esophageal sphincter dilation of the esophagus results in difficulty swallowing retention of food bolus is also noted chagas disease is one cause of megaesophagus in humans achalasia also predisposes to esophageal carcinoma megaesophagus can also be a symptom of another disease in dogs called myasthenia gravis myasthenia gravis is a neuromuscular disease where the primary symptom is weakness in various body parts of the dog however when myasthenia gravis occurs in older dogs it is thought of as an immune mediated disease often when myasthenia gravis is diagnosed in older dogs the first symptom the dog may manifest is megaesophagus myasthenia gravis occurs when acetylcholine receptors nicotinic acetylcholine receptors or achrs fail to function properly due to the inability of the nerve receptors to function appropriately the muscles fail to have a stimulus that causes them to contract an important distinction in recognizing megaesophagus is the difference between when a dog regurgitates or vomits regurgitating is a common symptom of megaesophagus while vomiting is not necessarily associated with megaesophagus when a dog regurgitates there is usually not as much effort involved as when a dog vomits often when regurgitating the dog will tip its head down and the liquid and or food will almost appear to spill out of its throat one of the primary dangers to a dog with megaesophagus is aspiration pneumonia because the food stays lodged in the throat it can often be inhaled into the lungs causing aspiration pneumonia one way to avoid this is to make sure that every time the dog eats or drinks anything that the dog sits for at least 10 minutes afterwards or is held in a sitting up or begging position this requires that all food and liquid intake be closely monitored and specifically administered to the dog in regular intervals sometimes as often as 2 – 3 hours in smaller quantities obviously if smaller quantities of food and water are administered one needs to take the necessary precaution to ensure the dog has a sufficient caloric and water intake according to many specialists this disorder has a guarded prognosis however since 2004 many owners have found a number of successful management techniques one of which is vertical feeding see bailey chair megaesophagus one horse breed the friesian horse has some individuals affected with megaesophagus and it appears to be genetic in origin
megalencephaly or macrencephaly abbreviated meg is a growth development disorder in which the brain is abnormally large it is characterized by a brain with an average weight that is 2 5 standard deviations above the mean of the general population megalencephaly is usually diagnosed at birth and is confirmed with an mri a mutation in the pi 3 k akt pathway is believed to be the primary cause of brain proliferation and ultimately the root cause of megalencephaly this mutation has produced a classification of brain overdevelopment that consists of two syndromes including megalencephaly capillary malformation mcap and megalencephaly polydactyly polymicrogyria hydrocephalus mpph approximately 1 out of 50 children 2 are said to have the characteristics of megalencephaly in the general population there are several neuropsychiatric disorders linked with megalencephaly however studies have shown that autism is the most prevalent association with the malformation of meg although no treatment currently exists for megalencephaly management methods are focused at reducing deficits linked with autism most recent research is targeted at creating inhibitors to reduce the mutational pathway that causes megalencephaly
megaloblastic anemia or megaloblastic anaemia is an anemia of macrocytic classification that results from inhibition of dna synthesis during red blood cell production when dna synthesis is impaired the cell cycle cannot progress from the g 2 growth stage to the mitosis m stage this leads to continuing cell growth without division which presents as macrocytosis megaloblastic anemia has a rather slow onset especially when compared to that of other anemias the defect in red cell dna synthesis is most often due to hypovitaminosis specifically a deficiency of vitamin b 12 and or folic acid vitamin b 12 deficiency alone will not cause the syndrome in the presence of sufficient folate as the mechanism is loss of b 12 dependent folate recycling followed by folate deficiency loss of nucleic acid synthesis specifically thymine leading to defects in dna synthesis folic acid supplementation in the absence of vitamin b 12 prevents this type of anemia although other vitamin b 12 specific pathologies may be present loss of micronutrients may also be a cause copper deficiency resulting from an excess of zinc from unusually high oral consumption of zinc containing denture fixation creams has been found to be a cause megaloblastic anemia not due to hypovitaminosis may be caused by antimetabolites that poison dna production directly such as some chemotherapeutic or antimicrobial agents for example azathioprine or trimethoprim the pathological state of megaloblastosis is characterized by many large immature and dysfunctional red blood cells megaloblasts in the bone marrow and also by hypersegmented neutrophils those exhibiting five or more nuclear lobes segments with up to four lobes being normal these hypersegmented neutrophils are found in the peripheral blood i e a diagnostic smear of a blood sample taken from the circulation
megarectum is a large rectum as a result of underlying nerve supply abnormalities or muscle dysfunction which remains after disimpaction of the rectum the principles of surgery textbook describes any rectum that can hold more than 1500 cc of fluid as a megarectum the term megarectum is also used for a large rectal mass on rectal examination a wide rectum on an abdominal x ray the presence of impaired rectal sensation or the finding of large maximal rectal volumes on anorectal manometry in addition can be the bloating of the colon due to infection also called megacolon on defecography megarectum is suggested by a rectal width of 9 cm at the level of the distal sacrum
megaureter is a medical anomaly whereby the ureter is abnormally dilated congenital megaureter is an uncommon condition which is more common in males may be bilateral and is often associated with other congenital anomalies the cause is thought to be aperistalsis of the distal ureter leading to dilatation a functional obstruction at the lower end of the ureter leads to progressive dilatation and a tendency to infection the ureteric orifice appears normal and a ureteric catheter passes easily definitive surgical treatment involves refashioning the lower end of the affected ureter so that a tunnelled reimplantation into the bladder can be done to prevent reflux
meige s syndrome is a type of dystonia it is also known as brueghel s syndrome and oral facial dystonia it is actually a combination of two forms of dystonia blepharospasm and oromandibular dystonia omd when omd is combined with blepharospasm it may be referred to as meige ’ s syndrome named after henri meige the french neurologist who first described the symptoms in detail in 1910 the symptoms usually begin between the ages of 30 and 70 years old and appear to be more common in women than in men 2 1 ratio the combination of upper and lower dystonia is sometimes called cranial cervical dystonia the incidence is about one case in 20 000 people
meige lymphedema also known as meige disease late onset lymphedema and lymphedema hereditary type 2 is an inherited disease in which patients develop lymphedema the onset is between the ages of 1 and 35 other causes of primary lympoedema include milroy s disease which occurs before the age of 1 and lymphoedema tarda which occurs after the age of 35 meige disease hereditary lymphedema type ii has its onset around the time of puberty it is an autosomal dominant disease it has been linked to a mutations in the ‘ forkhead ’ family transcription factor foxc 2 gene located on the long arm of chromosome 16 16 q 24 3 it is the most common form of primary lymphedema and about 2000 cases have been identified meige disease usually causes lymphedema of the legs however other areas of the body may be affected including the arms face and larynx yellow toe nails occur in some individuals
in medicine meigs syndrome also meigs syndrome or demons meigs syndrome is the triad of ascites pleural effusion and benign ovarian tumor fibroma fibrothecoma brenner tumour and occasionally granulosa cell tumour meigs syndrome resolves after the resection of the tumor because the transdiaphragmatic lymphatic channels are larger in diameter on the right the pleural effusion is classically on the right side the etiologies of the ascites and pleural effusion are poorly understood atypical meigs syndrome characterized by a benign pelvic mass with right sided pleural effusion but without ascites can also occur as in meigs syndrome pleural effusion resolves after removal of the pelvic mass
melancholic depression or depression with melancholic features is a dsm iv subtype of clinical depression requiring at least one of the following symptoms anhedonia the inability to find pleasure in positive things lack of mood reactivity i e mood does not improve in response to positive events and at least three of the following depression that is subjectively different from grief or loss severe weight loss or loss of appetite psychomotor agitation or retardation early morning awakening guilt that is excessive worse mood in the morning melancholic features apply to an episode of depression that occurs as part of either major depressive disorder or bipolar disorder i or ii melancholic depression is often considered to be a biologically based and particularly severe form of depression treatment involves antidepressants electroconvulsive therapy or other empirically supported treatments such as cognitive behavioral therapy and interpersonal therapy for depression a 2008 analysis of a large study of patients with unipolar major depression found a rate of 23 5 for melancholic features it was the first form of depression extensively studied and many of the early symptom checklists for depression reflect this the incidence of melancholic depression has been found to increase when the temperature and or sunlight are low according to the dsm iv the melancholic features specifier may be applied to the following only 1 major depressive episode single episode 2 major depressive episode recurrent episode 3 bipolar i disorder most recent episode depressed 4 bipolar ii disorder most recent episode depressed
a melanistic mask also referred to as a mask or masking is a dog coat pattern that gives the appearance of a mask on the dog s face the hairs on the muzzle and sometimes entire face or ears are colored by eumelanin instead of pheomelanin pigment eumelanin is typically black but may instead be brown dark gray or light gray brown pheomelanin ranges in color from pale cream to mahogany the trait is caused by m 264 v em a completely dominant allele form of the melanocortin 1 receptor gene
melanoacanthoma also known as pigmented seborrheic keratosis is a common benign darkly pigmented cutaneous condition characterized by a skin lesion with a dull or lackluster surface it involves a proliferation of keratinocytes and melanocytes
a melanocytic nevus also known as nevocytic nevus is a type of lesion that contains nevus cells a type of melanocyte some sources equate the term mole with melanocytic nevus other sources reserve the term mole for other purposes the majority of moles appear during the first two decades of a person s life with about one in every 100 babies being born with moles acquired moles are a form of benign neoplasm while congenital moles or congenital nevi are considered a minor malformation or hamartoma and may be at a higher risk for melanoma a mole can be either subdermal under the skin or a pigmented growth on the skin formed mostly of a type of cell known as a melanocyte the high concentration of the body s pigmenting agent melanin is responsible for their dark color moles are a member of the family of skin lesions known as nevi
melanocytic oral lesions are an extremely uncommon condition characterized by pigmented lesions of the mucous membranes
melanocytic tumors are tumours developed from melanocytes
melanocytic tumors of uncertain malignant potential meltump are melanocytic lesions in the dermis that cannot be classified by morphology as either benign naevi moles or malignant melanomas because the mass shows features of both several lesion types may be classified as meltumps these include atypical melanocytic proliferations with features that may overlap with atypical spitz naevi tumors dysplastic naevi pigmented epithelioid melanocytoma deep penetrating naevi congenital neavi cellular nodules in congenital naevi possible naevoid melanomas and cellular blue naevi a related category of melanocytic proliferation is superficial atypical melanocytic proliferations of uncertain significance sampus this category unlike meltump which implies as yet undetermined potential for metastases even after complete excision signifies lesions without metastatic potential at time of excision but with potential to progress upon incomplete excision the sampus category includes certain atypical junctional melanocytic proliferations and proliferations in both the epidermis and papillary dermis that are not accompanied by intradermal tumorigenic architecture or cell mitosis
melanoglossia is a medical condition in which the tongue becomes blackened this is usually caused by a bacterial infection or allergic reaction
melanoma also known as malignant melanoma is a type of cancer that develops from the pigment containing cells known as melanocytes melanomas typically occur in the skin but may rarely occur in the mouth intestines or eye in women they most commonly occur on the legs while in men they are most common on the back sometimes they develop from a mole with concerning changes including an increase in size irregular edges change in color itchiness or skin breakdown the primary cause of melanoma is ultraviolet light uv exposure in those with low levels of skin pigment the uv light may be from either the sun or from other sources such as tanning devices about 25 develop from moles those with many moles a history of affected family members and who have poor immune function are at greater risk a number of rare genetic defects such as xeroderma pigmentosum also increase risk diagnosis is by biopsy of any concerning skin lesion avoiding uv light and the use of sunscreen may prevent melanoma treatment is typically removal by surgery in those with slightly larger cancers nearby lymph nodes may be tested for spread most people are cured if spread has not occurred for those in whom melanoma has spread immunotherapy biologic therapy radiation therapy or chemotherapy may improve survival with treatment the five year survival rates in the united states is 98 among those with localized disease and 17 among those in whom spread has occurred the likelihood that it will come back or spread depends how thick the melanoma is how fast the cells are dividing and whether or not the overlying skin has broken down melanoma is the most dangerous type of skin cancer globally in 2012 it occurred in 232 000 people and resulted in 55 000 deaths australia and new zealand have the highest rates of melanoma in the world there are also high rates in europe and north america while it is less common in asia africa and latin america melanoma is more common in men than women melanoma has become more common since the 1960 s in areas that are mostly caucasian
melanoma associated leukoderma is a cutaneous condition and is a vitiligo like depigmentation that can occur in patients with cutaneous or ocular melanoma
melanoma with features of a spitz nevus also known as a spitzoid melanoma is a cutaneous condition characterized histologically with tissue similar to a spitz nevus and with overall symmetry and a dermal nodule of epithelioid melanocytes that do not mature with progressively deeper dermal extension
melanonychia is a black or brown pigmentation of the normal nail plate and may be present as a normal finding on many digits in african americans as a result of trauma systemic disease or medications or as a postinflammatory event from such localized events as lichen planus or fixed drug eruption there are two types longitudinal and transverse melanonychia longitudinal melanonychia may be a sign of subungual melanoma acral lentiginous melanoma although there are other diagnoses such as chronic paronychia onychomycosis subungual hematoma pyogenic granuloma glomus tumour subungual verruca mucous cyst subungual fibroma keratoacanthoma carcinoma of the nail bed and subungual exostosis
melanosis coli also pseudomelanosis coli is a disorder of pigmentation of the wall of the colon often identified at the time of colonoscopy it is benign and may have no significant correlation with disease the brown pigment is lipofuscin in macrophages not melanin
melanotic neuroectodermal tumor of infancy mnti is a very rare oral cavity tumor that is seen in patients usually at or around birth it must be removed to be cured definitions a rare biphasic neuroblastic and pigmented epithelial neoplasm of craniofacial sites usually involving the oral cavity or gums synonyms melanotic progonoma
melasma also known as chloasma faciei or the mask of pregnancy when present in pregnant women is a tan or dark skin discoloration although it can affect anyone melasma is particularly common in women especially pregnant women and those who are taking oral or patch contraceptives or hormone replacement therapy hrt medications
meleda disease mdm or mal de meleda also called mljet disease keratosis palmoplantaris and transgradiens of siemens also known as acral keratoderma mutilating palmoplantar keratoderma of the gamborg nielsen type palmoplantar ectodermal dysplasia type viii and palmoplantar keratoderma of the norrbotten type is an extremely rare autosomal recessive congenital skin disorder in which dry thick patches of skin develop on the soles of the hands and feet a condition known as palmoplantar hyperkeratosis
melioidosis is an infectious disease caused by a gram negative bacterium burkholderia pseudomallei found in soil and water it is of public health importance in endemic areas particularly in vietnam and northern australia it exists in acute and chronic forms signs and symptoms may include pain in chest bones or joints cough skin infections lung nodules and pneumonia b pseudomallei was previously classed as part of the pseudomonas genus until 1992 it was known as pseudomonas pseudomallei it is phylogenetically related closely to burkholderia mallei which causes glanders an infection primarily of horses donkeys and mules the name melioidosis is derived from the greek melis μηλις meaning a distemper of asses with the suffixes oid meaning similar to and osis meaning a condition that is a condition similar to glanders
melkersson – rosenthal syndrome also termed miescher melkersson rosenthal syndrome is a rare neurological disorder characterized by recurring facial paralysis swelling of the face and lips usually the upper lip and the development of folds and furrows in the tongue onset is in childhood or early adolescence after recurrent attacks ranging from days to years in between swelling may persist and increase eventually becoming permanent the lip may become hard cracked and fissured with a reddish brown discoloration the cause of melkersson – rosenthal syndrome is unknown but there may be a genetic predisposition it has been noted to be especially prevalent among certain ethnic groups in bolivia it can be symptomatic of crohn s disease or sarcoidosis
melnick – needles syndrome mns also known as melnick – needles osteodysplasty is an extremely rare congenital disorder that affects primarily bone development patients with melnick – needles syndrome have typical faces exophthalmos full cheeks micrognathia and malalignment of teeth flaring of the metaphyses of long bones s like curvature of bones of legs irregular constrictions in the ribs and sclerosis of base of skull in males the disorder is nearly always lethal in infancy lifespan of female patients might not be affected melnick – needles syndrome is associated with mutations in the flna gene and is inherited in an x linked dominant manner as with many genetic disorders there is no known cure to mns the disorder was first described by john c melnick and carl f needles in 1966 in two multi generational families
in music cognition melodic fission also known as melodic or auditory streaming or stream segregation is a phenomenon in which one line of pitches an auditory stream is heard as two or more separate melodic lines this occurs when a phrase contains groups of pitches at two or more distinct registers or with two or more distinct timbres the term appears to stem from a 1973 paper by w j dowling in music analysis and more specifically in schenkerian analysis the phenomenon more often is termed compound melody in psychophysics auditory scene analysis is the process by which the brain separates and organizes sounds into perceptually distinct groups known as auditory streams the counterpart to melodic fission is melodic fusion
in music and jazz improvisation a melodic pattern or sequence is a repetitive pattern that can be used with any scale it is used primarily for use in solos because when practiced enough it can be extremely useful when improvising
melorheostosis is a medical developmental disorder and mesenchymal dysplasia in which the bony cortex widens and becomes hyperdense in a sclerotomal distribution the condition begins in childhood and is characterized by thickening of the bones pain is a frequent symptom and the bone can have the appearance of dripping candle wax
a melt freeze crust or rain crust is a discontinuity between snow layers which can lead to avalanches the layer can be created in two ways a temperature high enough to allow surface snow to melt creating a layer of melt water which may later re freeze rain falling and freezing on the surface of existing snow also creating a frozen layer this layer is brittle smooth and slippery and does not bond with snow layers above it allowing the overlying slab of snow to move down the mountain under gravity when disturbed or if the accumulated snowfall exceeds a critical mass the initial slab may be as large as 10 000 m ² and 10 metres thick
melting point depression is the phenomenon of reduction of the melting point of a material with reduction of its size this phenomenon is very prominent in nanoscale materials which melt at temperatures hundreds of degrees lower than bulk materials
membrane potential also transmembrane potential or membrane voltage is the difference in electric potential between the interior and the exterior of a biological cell with respect to the exterior of the cell typical values of membrane potential range from – 40 mv to – 80 mv all animal cells are surrounded by a membrane composed of a lipid bilayer with proteins embedded in it the membrane serves as both an insulator and a diffusion barrier to the movement of ions ion transporter pump proteins actively push ions across the membrane and establish concentration gradients across the membrane and ion channels allow ions to move across the membrane down those concentration gradients ion pumps and ion channels are electrically equivalent to a set of batteries and resistors inserted in the membrane and therefore create a voltage between the two sides of the membrane virtually all eukaryotic cells including cells from animals plants and fungi maintain a non zero transmembrane potential usually with a negative voltage in the cell interior as compared to the cell exterior ranging from – 40 mv to – 80 mv the membrane potential has two basic functions first it allows a cell to function as a battery providing power to operate a variety of molecular devices embedded in the membrane second in electrically excitable cells such as neurons and muscle cells it is used for transmitting signals between different parts of a cell signals are generated by opening or closing of ion channels at one point in the membrane producing a local change in the membrane potential this change in the electric field can be quickly affected by either adjacent or more distant ion channels in the membrane those ion channels can then open or close as a result of the potential change reproducing the signal in non excitable cells and in excitable cells in their baseline states the membrane potential is held at a relatively stable value called the resting potential for neurons typical values of the resting potential range from – 70 to – 80 millivolts that is the interior of a cell has a negative baseline voltage of a bit less than one tenth of a volt the opening and closing of ion channels can induce a departure from the resting potential this is called a depolarization if the interior voltage becomes less negative say from – 70 mv to – 60 mv or a hyperpolarization if the interior voltage becomes more negative say from – 70 mv to – 80 mv in excitable cells a sufficiently large depolarization can evoke an action potential in which the membrane potential changes rapidly and significantly for a short time on the order of 1 to 100 milliseconds often reversing its polarity action potentials are generated by the activation of certain voltage gated ion channels in neurons the factors that influence the membrane potential are diverse they include numerous types of ion channels some of which are chemically gated and some of which are voltage gated because voltage gated ion channels are controlled by the membrane potential while the membrane potential itself is influenced by these same ion channels feedback loops that allow for complex temporal dynamics arise including oscillations and regenerative events such as action potentials
membranoproliferative glomerulonephritis mpgn also known as mesangiocapillary glomerulonephritis is a type of glomerulonephritis caused by deposits in the kidney glomerular mesangium and basement membrane gbm thickening activating complement and damaging the glomeruli mpgn accounts for approximately 4 of primary renal causes of nephritic syndrome in children and 7 in adults it should not be confused with membranous glomerulonephritis a condition in where the basement membrane is thickened but the mesangium is not
membranous aplasia cutis is a cutaneous condition a type of aplasia cutis congenita which can be seen along the embryonic fusion lines of the face
membranous glomerulonephritis mgn is a slowly progressive disease of the kidney affecting mostly people between ages of 30 and 50 years usually caucasian it is the second most common cause of nephrotic syndrome in adults with focal segmental glomerulosclerosis fsgs recently becoming the most common
the memento pattern is a software design pattern that provides the ability to restore an object to its previous state undo via rollback the memento pattern is implemented with three objects the originator a caretaker and a memento the originator is some object that has an internal state the caretaker is going to do something to the originator but wants to be able to undo the change the caretaker first asks the originator for a memento object then it does whatever operation or sequence of operations it was going to do to roll back to the state before the operations it returns the memento object to the originator the memento object itself is an opaque object one which the caretaker cannot or should not change when using this pattern care should be taken if the originator may change other objects or resources the memento pattern operates on a single object classic examples of the memento pattern include the seed of a pseudorandom number generator it will always produce the same sequence thereafter when initialized with the seed state and the state in a finite state machine
memory distrust syndrome is a condition coined by gísli guðjónsson and james mackeith in 1982 in which an individual doubts the accuracy of their memory concerning the content and context of events of which they have experienced since the individual does not trust their own memory they will commonly depend on outside sources of information rather than using their ability for recollection some believe that this may be a defense or coping mechanism to a preexisting faulty memory state such as alzheimer s disease amnesia or possibly dementia the condition is generally considered to be related to source amnesia which involves the inability to recall the basis for factual knowledge the main difference between the two is that source amnesia is a lack of knowing the basis of knowledge whereas memory distrust syndrome is a lack of believing the knowledge that exists the fact that an individual lacks the trust in their own memory implies that the individual would have a reason or belief that would prevent them from the trust that most of us have in our recollections cases concerning memory distrust syndrome have led to documented false confessions in court cases
memory effect also known as battery effect lazy battery effect or battery memory is an effect observed in nickel cadmium and nickel – metal hydride rechargeable batteries that causes them to hold less charge it describes the specific situation in which nicd batteries gradually lose their maximum energy capacity if they are repeatedly recharged after being only partially discharged the battery appears to remember the smaller capacity
in psychology memory inhibition is the ability not to remember irrelevant information the scientific concept of memory inhibition should not be confused with everyday uses of the word inhibition scientifically speaking memory inhibition is a type of cognitive inhibition which is the stopping or overriding of a mental process in whole or in part with or without intention memory inhibition is a critical component of an effective memory system while some memories are retained for a lifetime most memories are forgotten according to evolutionary psychologists forgetting is adaptive because it facilitates selectivity of rapid efficient recollection for example a person trying to remember where he parked his car would not want to remember every place he has ever parked in order to remember something therefore it is essential not only to activate the relevant information but also to inhibit irrelevant information there are many memory phenomena that seem to involve inhibition although there is often debate about the distinction between interference and inhibition
in operating systems memory management is the function responsible for managing the computer s primary memory the memory management function keeps track of the status of each memory location either allocated or free it determines how memory is allocated among competing processes deciding which gets memory when they receive it and how much they are allowed when memory is allocated it determines which memory locations will be assigned it tracks when memory is freed or unallocated and updates the status
mendelian susceptibility to mycobacterial disease also called familial disseminated atypical mycobacterial infection is a rare genetic disease characterized by susceptibility to mycobacteria and salmonella infection outside of the intestinal tract
mendelson s syndrome is chemical pneumonitis or aspiration pneumonitis caused by aspiration during anaesthesia especially during pregnancy aspiration contents may include gastric juice blood bile water or an association of them
meningeal carcinomatosis is a condition in which a solid tumor diffusely spreads to the leptomeninges lung tumors breast tumors and malignant melanoma comprise the majority of solid tumors spreading to the leptomeninges
meningioangiomatosis is a rare disease of the brain it is characterized by a benign lesion of the leptomeninges usually involving the cerebral cortex and by leptomeningeal and meningovascular proliferation often the patient will present with seizures the disease may be either sporadic or associated with neurofibromatosis type 2 the lesion is usually focused in one place though extremely rare multifocal cases have been reported in both adults and children biopsy is usually necessary for diagnosis treatment conventionally involves surgical removal of the lesion
meningiomas are a diverse set of tumors arising from the meninges the membranous layers surrounding the central nervous system many meningiomas produce no symptoms throughout a person s life and if discovered require no treatment other than periodic observation typically symptomatic meningiomas are treated with either radiosurgery or conventional surgery they arise from the arachnoid cap cells of the arachnoid villi in the meninges these tumors usually are benign in nature however a small percentage are cancerous historical evidence of meningiomas has been found going back hundreds of years with some successful surgeries for their removal beginning in the 1800 s
meningism is the triad of nuchal rigidity neck stiffness photophobia intolerance of bright light and headache it is a sign of irritation of the meninges such as seen in meningitis subarachnoid hemorrhages and various other diseases meningismus is the term used when the above listed symptoms are present without actual infection or inflammation usually it is seen in concordance with other acute illnesses in the pediatric population related clinical signs include kernig s sign and three signs all named brudzinski s sign
meningitis is an acute inflammation of the protective membranes covering the brain and spinal cord known collectively as the meninges the most common symptoms are fever headache and neck stiffness other symptoms include confusion or altered consciousness vomiting and an inability to tolerate light or loud noises young children often exhibit only nonspecific symptoms such as irritability drowsiness or poor feeding if a rash is present it may indicate a particular cause of meningitis for instance meningitis caused by meningococcal bacteria may be accompanied by a characteristic rash the inflammation may be caused by infection with viruses bacteria or other microorganisms and less commonly by certain drugs meningitis can be life threatening because of the inflammation s proximity to the brain and spinal cord therefore the condition is classified as a medical emergency a lumbar puncture diagnoses or excludes meningitis a needle is inserted into the spinal canal to collect a sample of cerebrospinal fluid csf that envelops the brain and spinal cord the csf is examined in a medical laboratory some forms of meningitis are preventable by immunization with the meningococcal mumps pneumococcal and hib vaccines giving antibiotics to people with significant exposure to certain types of meningitis may also be useful the first treatment in acute meningitis consists of promptly giving antibiotics and sometimes antiviral drugs corticosteroids can also be used to prevent complications from excessive inflammation meningitis can lead to serious long term consequences such as deafness epilepsy hydrocephalus or cognitive deficits especially if not treated quickly in 2013 meningitis occurred in about 16 million people worldwide this resulted in 303 000 deaths – down from 464 000 deaths in 1990 with appropriate treatment the risk of death in bacterial meningitis is less than 15 outbreaks of bacterial meningitis occur between december and june each year in an area of sub saharan africa known as the meningitis belt smaller outbreaks may also occur in other areas of the world the word meningitis is from greek μῆνιγξ méninx membrane and the medical suffix itis inflammation
meningococcal disease describes infections caused by the bacterium neisseria meningitidis also termed meningococcus it carries a high mortality rate if untreated but is a vaccine preventable disease while best known as a cause of meningitis widespread blood infection can result in sepsis which is a more damaging and dangerous condition meningitis and meningococcemia are major causes of illness death and disability in both developed and under developed countries there are approximately 2 600 cases of bacterial meningitis per year in the united states and on average 333 000 cases in developing countries the case fatality rate ranges between 10 and 20 percent the incidence of endemic meningococcal disease during the last 13 years ranges from 1 to 5 per 100 000 in developed countries and from 10 to 25 per 100 000 in developing countries during epidemics the incidence of meningococcal disease approaches 100 per 100 000 meningococcal vaccines have sharply reduced the incidence of the disease in developed countries the disease s pathogenesis is not fully understood the pathogen colonises a large number of the general population harmlessly but in some very small percentage of individuals it can invade the blood stream and the entire body but notably limbs and brain causing serious illness over the past few years experts have made an intensive effort to understand specific aspects of meningococcal biology and host interactions however the development of improved treatments and effective vaccines is expected to depend on novel efforts by workers in many different fields while meningococcal disease is not as contagious as the common cold which is spread through casual contact it can be transmitted through saliva and occasionally through close prolonged general contact with an infected person
meningoencephalitis mɪˌnɪŋɡoʊɛnˌsɛfəˈlaɪtᵻs ˌnɪndʒoʊ ən ˌkɛ from greek meninges membranes enkephalos brain and itis inflammation is a medical condition that simultaneously resembles both meningitis which is an infection or inflammation of the meninges and encephalitis which is an infection or inflammation of the brain
meningohydroencephalocoele ame meningohydroencephalocele is a form of meningocele ame a developmental abnormality of the central nervous system like meningocoele meningohydroencephalocoele is caused by defects in bone ossification in particular the intramembranous ossification related to the closure of infantile fontanelles it refers to the protrusion of the meninges between the un fused bones to lie subcutaneously meningocoele refers to herniation of meninges meningoencephalocoele refers to the condition if brain tissue is included with the meninges in the herniation meningohydroencephalocoele refers to the condition including meninges brain tissue and part of the ventricular system in the herniation these defects occur in approximately 1 in 2000 live births
a meniscal cyst is a well defined cystic lesion located along the peripheral margin of the meniscus a part of the knee nearly always associated with horizontal meniscal tears
a meniscus transplant or meniscal transplant is a transplant of the meniscus of the knee which separates the thigh bone femur from the lower leg bone tibia the worn or damaged meniscus is removed and is replaced with a new one from a donor the meniscus to be transplanted is taken from a cadaver and as such is known as an allograft meniscal transplantation is technically difficult as it must be sized accurately for each person positioned properly and secured to the tibial plateau as of 2012 only a few surgeons have significant volume of experience in meniscus transplantation worldwide
menkes disease mnk also known as menkes syndrome is an x linked recessive disorder that affects copper levels in the body leading to copper deficiency the onset of menkes disease typically begins during infancy affecting about 1 in 100 000 to 250 000 newborns infants with mnk syndrome often do not live past the age of 3 it is more common in males than females because it only takes one copy of the x linked recessive gene to be expressed for a male to develop the disease in order for females to develop the disorder they would need to express two copies of the gene one on each x chromosome to develop the disorder mnk is characterized by kinky hair growth failure and deterioration of the nervous system it is caused by mutations in the copper transport gene atp 7 a which is responsible for making a protein that is important for regulating the copper levels in the body the disorder was originally described by john hans menkes 1928 – 2008 et al in 1962 alternative names copper transport disease steely hair disease kinky hair disease menkes kinky hair syndrome
menometrorrhagia is a condition in which prolonged or excessive uterine bleeding occurs irregularly and more frequently than normal it is thus a combination of metrorrhagia and menorrhagia
menopause also known as the climacteric is the time in most women s lives when menstrual periods stop permanently and they are no longer able to bear children menopause typically occurs between 49 and 52 years of age medical professionals often define menopause as having occurred when a woman has not had any vaginal bleeding for a year it may also be defined by a decrease in hormone production by the ovaries in those who have had surgery to remove their uterus but they still have ovaries menopause may be viewed to have occurred at the time of the surgery or when their hormone levels fell following the removal of the uterus symptoms typically occur earlier at an average of 45 years of age before menopause a woman s periods typically become irregular which means that periods may be longer or shorter in duration or be lighter or heavier in the amount of flow during this time women often experience hot flashes these typically last from 30 seconds to ten minutes and may be associated with shivering sweating and reddening of the skin hot flashes often stop occurring after a year or two other symptoms may include vaginal dryness trouble sleeping and mood changes the severity of symptoms varies between women while menopause is often thought to be linked to an increase in heart disease this primarily occurs due to increasing age and does not have a direct relationship with menopause in some women problems that were present like endometriosis or painful periods will improve after menopause menopause is usually a natural change it can occur earlier in those who smoke tobacco other causes include surgery that removes both ovaries or some types of chemotherapy at the physiological level menopause happens because of a decrease in the ovaries production of the hormones estrogen and progesterone while typically not needed a diagnosis of menopause can be confirmed by measuring hormone levels in the blood or urine menopause is the opposite of menarche the time when a girl s periods start specific treatment is not usually needed some symptoms however may be improved with treatment with respect to hot flashes avoiding smoking caffeine and alcohol is often recommended sleeping in a cool room and using a fan may help the following medications may help menopausal hormone therapy mht clonidine gabapentin or selective serotonin reuptake inhibitors exercise may help with sleeping problems while mht was once routinely prescribed it is now only recommended in those with significant symptoms as there are concerns about side effects high quality evidence for the effectiveness of alternative medicine has not been found there is tentative evidence for soy isoflavones
a menstrual disorder is an abnormal condition in a woman s menstrual cycle
menstruation in mammals is the shedding of the uterine lining endometrium it occurs on a regular basis in sexually reproductive age females of certain mammal species though there is some disagreement in definitions between sources menstruation is generally considered to be limited to primates overt menstruation where there is bleeding from the uterus through the vagina is found primarily in humans and close relatives such as chimpanzees it is common in simians old world monkeys new world monkeys and apes but completely lacking in strepsirrhine primates and possibly weakly present in tarsiers beyond primates it is known only in bats and the elephant shrew females of other species of placental mammal undergo estrous cycles in which the endometrium is completely reabsorbed by the animal covert menstruation at the end of its reproductive cycle many zoologists regard this as different from a true menstrual cycle female domestic animals used for breeding — for example dogs pigs cattle or horses — are monitored for physical signs of an estrous cycle period which indicates that the animal is ready for insemination
emotional disabilities redirects here for other uses see emotional disability a mental disorder also called a mental illness or psychiatric disorder is a diagnosis by a mental health professional of a behavioral or mental pattern that may cause suffering or a poor ability to function in life such features may be persistent relapsing and remitting or occur as a single episode many disorders have been described with signs and symptoms that vary widely between specific disorders the causes of mental disorders are often unclear theories may incorporate findings from a range of fields mental disorders are usually defined by a combination of how a person behaves feels perceives or thinks this may be associated with particular regions or functions of the brain often in a social context a mental disorder is one aspect of mental health cultural and religious beliefs as well as social norms should be taken into account when making a diagnosis services are based in psychiatric hospitals or in the community and assessments are carried out by psychiatrists clinical psychologists and clinical social workers using various methods but often relying on observation and questioning treatments are provided by various mental health professionals psychotherapy and psychiatric medication are two major treatment options other treatments include social interventions peer support and self help in a minority of cases there might be involuntary detention or treatment prevention programs have been shown to reduce depression common mental disorders include depression which affects about 400 million dementia which affects about 35 million and schizophrenia which affects about 21 million people globally stigma and discrimination can add to the suffering and disability associated with mental disorders leading to various social movements attempting to increase understanding and challenge social exclusion
mental disorders diagnosed in childhood are divided into two categories childhood disorders and learning disorders these disorders are usually first diagnosed in infancy childhood or adolescence as laid out in the dsm iv tr and in the icd 10 the dsm iv tr includes ten subcategories of disorders including mental retardation learning disorders motor skills disorders communication disorders pervasive developmental disorders attention deficit and disruptive behavior disorders feeding and eating disorders tic disorders elimination disorders and other disorders of infancy childhood or adolescence
mental health triage is a clinical function conducted at point of entry to health services which aims to assess and categorize the urgency of mental health related problems the mental health triage service may be located in the emergency department community mental health services call centre or co located with other specialist mental health services such as the crisis assessment and treatment team emergency services such as police and ambulance may also have a co located mental health triage service there is considerable variation in the clinical settings in which mental health triage services may be operating therefore service delivery models vary however the essential function is to determine the nature and severity of the mental health problem determine which service response would best meet the needs of the patient and how urgently the response is required a core function of mental health triage is to conduct risk assessment that aims to determine whether the patient is a risk of harming self or others as a result of their mental state and to assess other risks related to mental illness as with other triage models the mental health triage clinician must assign a category of urgency to the case which is recorded using verbal indicators of risk such as extreme risk through to low risk or by using numerical urgency time to treatment categories 1 immediate to 5 2 hours as per the 5 point australasian triage scale
mental retardation and microcephaly with pontine and cerebellar hypoplasia micpch also known as mental retardation x linked syndromic najm type mrxsna is a rare genetic disorder of infants characterised by intellectual disability and pontocerebellar hypoplasia the disorder is associated with a mutation in the cask gene which is transmitted in an x linked manner as with the vast majority of genetic disorders there is no known cure to micpch the following values seem to be aberrant in children with cask gene defects lactate pyruvate 2 ketoglutarate adipic acid and suberic acid which seems to backup the proposal that cask affects mitochondrial function it is also speculated that phosphoinositide 3 kinase in the inositol metabolism is impacted in the disease causing folic acid metabolization problems
mental rotation is the ability to rotate mental representations of two dimensional and three dimensional objects as it is related to the visual representation of such rotation within the human mind
in psychology mentalization is the ability to understand the mental state of oneself or others that underlies overt behaviour mentalization can be seen as a form of imaginative mental activity that lets us perceive and interpret human behaviour in terms of intentional mental states e g needs desires feelings beliefs goals purposes and reasons another term that david wallin has used for mentalization is thinking about thinking while the theory of mind has been discussed in philosophy at least since descartes the concept of mentalization emerged in psychoanalytic literature in the late 1960 s and became empirically tested in 1983 when heinz wimmer and josef perner ran the first experiment to investigate when children can understand false belief inspired by daniel dennett s interpretation of a punch and judy scene the field diversified in the early 1990 s when simon baron cohen and uta frith building on the wimmer and perner study and others merged it with research on the psychological and biological mechanisms underlying autism and schizophrenia concomitantly peter fonagy and colleagues applied it to developmental psychopathology in the context of attachment relationships gone awry more recently several child mental health researchers such as arietta slade john grienenberger alicia lieberman daniel schechter and susan coates have applied mentalization both to research on parenting and to clinical interventions with parents infants and young children mentalization has implications for attachment theory and self development according to peter fonagy individuals without proper attachment e g due to physical psychological or sexual abuse can have greater difficulty developing mentalization abilities attachment history partially determines the strength of mentalizing capacity of individuals securely attached individuals tend to have had a primary caregiver that has more complex and sophisticated mentalizing abilities as a consequence these children possess more robust capacities to represent the states of their own and other people ’ s minds early childhood exposure to mentalization can protect the individual from psychosocial adversity this theory needs further empirical support
meralgia paresthetica or meralgia paraesthetica or bernhardt roth syndrome is numbness or pain in the outer thigh not caused by injury to the thigh but by injury to a nerve that extends from the thigh to the spinal column this chronic neurological disorder involves a single nerve — the lateral cutaneous nerve of thigh which is also called the lateral femoral cutaneous nerve and hence the syndrome lateral femoral cutaneous neuropathy the term meralgia paraesthetica combines four greek roots to mean thigh pain with anomalous perception
merciful anosmia is a condition in which the person is unaware of the foul smell emanating from his own nose this condition is seen in atrophic rhinitis in atrophic rhinitis the turbinates venous sinusoids seromucinous glands and nerves undergo atrophy resulting in a foul smelling discharge as the nerve fibres sensing smell are also atrophied the patient is unable to appreciate the foul smell
the mercury beating heart is an electrochemical redox reaction between the elements mercury iron and chromium the reaction causes a blob of mercury in water to oscillate the observeable reaction demonstrates an effect of a non homogeneous electrical double layer it is often used as a classroom demonstration
mercury granulomas is the result of mercury exposure a skin condition characterized by foreign body giant cell reaction
mercury poisoning also known as hydrargyria or mercurialism is a type of metal poisoning a medical condition caused by exposure to mercury or its compounds mercury chemical symbol hg is a heavy metal occurring in several forms all of these except elemental liquid mercury for which intravenous injection of a certain volume is required produce toxicity or death with less than a gram the damage done by elemental mercury is caused by blocking blood vessels mercury s zero oxidation state hg 0 exists as vapor or as liquid metal its mercurous state hg exists as inorganic salts and its mercuric state hg 2 may form either inorganic salts or organomercury compounds the three groups vary in effects toxic effects include damage to the brain kidneys and lungs mercury poisoning can result in several diseases including acrodynia pink disease hunter russell syndrome and minamata disease symptoms typically include sensory impairment vision hearing speech disturbed sensation and a lack of coordination the type and degree of symptoms exhibited depend upon the individual toxin the dose and the method and duration of exposure
the mere exposure effect is a psychological phenomenon by which people tend to develop a preference for things merely because they are familiar with them in social psychology this effect is sometimes called the familiarity principle the effect has been demonstrated with many kinds of things including words chinese characters paintings pictures of faces geometric figures and sounds in studies of interpersonal attraction the more often a person is seen by someone the more pleasing and likeable that person appears to be
the mere addition paradox also known as the repugnant conclusion is a problem in ethics identified by derek parfit and appearing in his book reasons and persons 1984 the paradox identifies an inconsistency between four seemingly true beliefs about the relative value of populations
the meredith effect is a phenomenon whereby the aerodynamic drag produced by a cooling radiator may be offset by careful design of the cooling duct such that useful thrust is produced the effect was discovered in the 1930 s and became more important as the speeds of piston engined aircraft increased over the next decade
in meteorology a meridional flow is a general air flow pattern from north to south or from south to north along the earth s longitude lines perpendicular to a zonal flow extratropical cyclones in this environment tend to be stronger and move slower this pattern is responsible for most instances of extreme weather as not only are storms stronger in this type of flow regime but temperatures can reach extremes as well producing heat waves and cold waves depending on the equator ward or poleward direction of the flow
merkel cell carcinoma mcc is a rare and highly aggressive skin cancer which in most cases is caused by the merkel cell polyomavirus mcv discovered by scientists at the university of pittsburgh in 2008 it is also known as cutaneous apudoma primary neuroendocrine carcinoma of the skin primary small cell carcinoma of the skin and trabecular carcinoma of the skin approximately 80 of merkel cell carcinomas are caused by mcv the virus is clonally integrated into the cancerous merkel cells in addition the virus has a particular mutation only when found in cancer cells but not when it is detected in healthy skin cells direct evidence for this oncogenetic mechanism comes from research showing that inhibition of production of mcv proteins causes mcv infected merkel carcinoma cells to die but has no effect on malignant merkel cells that are not infected with this virus mcv uninfected tumors which account for approximately 20 of merkel cell carcinomas appear to have a separate and as yet unknown cause these tumors tend to have extremely high genome mutation rates due to ultraviolet light exposure whereas mcv infected merkel cell carcinomas have low rates of genome mutation no other cancers have been confirmed so far to be caused by this virus because of the viral origin for this cancer immunotherapies are a promising avenue for research to treat virus positive merkel cell carcinoma this cancer is considered to be a form of neuroendocrine tumor while patients with a small tumor less than 2 cm that has not yet metastasized to regional lymph nodes have an expected 5 year survival rate of more than 80 percent once a lesion has metastasized regionally the rate drops to about 50 percent up to half of patients that have been seemingly treated successfully i e that initially appear cancer free subsequently suffer a recurrence of their disease recent reviews cite an overall 5 year survival rate of about 60 for all mcc combined merkel cell carcinoma occurs most often on the sun exposed face head and neck
merle is a pattern in a dog s coat merle comes in different colors and patterns some have blue patches throughout and are considered blue merle same with red and chocolate although some describe merle as only a pattern dna testing identifies the merle gene but not the variety of colors and patterns seen in the coats of the dogs with the gene a dilute black bb or bb dog is generally known as blue but a dog with a merle coat does not test bb or bb but still is a blue dilute from the merle gene the merle gene creates mottled patches of color in a solid or piebald coat blue or odd colored eyes and can affect skin pigment as well health issues are more typical and more severe when two merles are bred together so it is recommended that a merle be bred to a dog with a solid coat color only
meromelia is a birth defect characterized by the lacking of a part but not all of one or more limbs with the presence of a hand or foot it results in a shrunken and deformed extremity
in the mathematical field of complex analysis a meromorphic function on an open subset d of the complex plane is a function that is holomorphic on all d except for a set of isolated points which are poles of the function this terminology comes from the ancient greek meros μέρος meaning part as opposed to holos ὅλος meaning whole every meromorphic function on d can be expressed as the ratio between two holomorphic functions with the denominator not constant 0 defined on d any pole must coincide with a zero of the denominator intuitively a meromorphic function is a ratio of two well behaved holomorphic functions such a function will still be well behaved except possibly at the points where the denominator of the fraction is zero if the denominator has a zero at z and the numerator does not then the value of the function will be infinite if both parts have a zero at z then one must compare the multiplicities of these zeros from an algebraic point of view if d is connected then the set of meromorphic functions is the field of fractions of the integral domain of the set of holomorphic functions this is analogous to the relationship between the rational numbers and the integers
mesangial proliferative glomerulonephritis is a form of glomerulonephritis associated primarily with the mesangium there is some evidence that interleukin 10 may inhibit it in an animal model it is classified as type ii lupus nephritis by the world health organization who
mesenchymal chondrosarcoma is a form of malignant chondrosarcoma unlike most chondrosarcomas mesenchymal chondrosarcoma grows rapidly tends to spread and occurs more often in children and young adults than in older adults type ii collagen can help distinguish it from other tumors
a mesenteric cyst mesh c 04 182 473 is a cyst in the mesenterium and is one of the rarest abdominal tumors with approximately 821 cases reported since 1507 the incidence is between 1 per 100 000 to 1 per 250 000 hospital admissions
mesenteric ischemia is a medical condition in which injury of the small intestine occurs due to not enough blood supply it can come on suddenly known as acute mesenteric ischemia or gradually known as chronic mesenteric ischemia acute disease often presents with sudden severe pain symptoms may come on more slowly in those with acute on chronic disease signs and symptoms of chronic disease include abdominal pain after eating unintentional weight loss vomiting and being afraid of eating risk factors include atrial fibrillation heart failure chronic renal failure being prone to forming blood clots and previous myocardial infarction there are four mechanisms by which poor blood flow occurs a blood clot from elsewhere getting lodged in an artery a new blood clot forming in an artery a blood clot forming in the mesenteric vein and insufficient blood flow due to low blood pressure or spasms of arteries chronic disease is a risk factor for acute disease the best method of diagnosis is angiography with computer tomography ct being used when that is not available treatment of acute ischemia may include stenting or medications to break down the clot provided at the site of obstruction by interventional radiology open surgery may also be used to remove or bypass the obstruction and may be required to remove any intestines that may have died if not rapidly treated outcomes are often poor among those affected even with treatment the risk of death is 70 to 90 in those with chronic disease bypass surgery is the treatment of choice those who have thrombosis of the vein may be treated with anticoagulation such as heparin and warfarin with surgery used if they do not improve acute mesenteric ischemia affects about five per hundred thousand people per year in the developed world chronic mesenteric ischemia affects about one per hundred thousand people most people affected are over 60 years old rates are about equal in males and females of the same age mesenteric ischemia was first described in 1895
congenital mesoblastic nephroma is a type of kidney tumor that is usually found before birth by ultrasound or within the first 3 months of life it contains fibroblastic cells connective tissue cells and may spread to the other kidney or to nearby tissue congenital mesoblastic nephroma is more common in males
mesomelia refers to conditions in which the middle parts of limbs are disproportionately short when applied to skeletal dysplasias mesomelic dwarfism describes generalised shortening of the forearms and lower legs this is in contrast to rhizomelic dwarfism in which the upper portions of limbs are short such as in achondroplasia forms of mesomelic dwarfism currently described include langer mesomelic dysplasia ellis – van creveld syndrome robinow syndrome léri – weill dyschondrosteosis
mesothelial hyperplasia is a hyperplasia of mesothelial cells in serous membranes pleura pericardium peritoneum mesothelial hyperplasia is usually an incidental finding during peritoneal examination during laparotomy or laparoscopy grossly mesothelial hyperplasia is characterized by the presence of small white nodules or flat plaques on the serous surface
mesothelioma is a type of cancer that develops from the thin layer of tissue that covers many of the internal organs known as the mesothelium the most common area affected is the lining of the lungs and chest wall less commonly the lining of the abdomen and rarely the sac surrounding the heart or the sac surrounding the testis may be affected signs and symptoms of mesothelioma may include shortness of breath due to fluid around the lung a swollen abdomen chest wall pain cough feeling tired and weight loss these symptoms typically come on slowly greater than 80 of mesothelioma is caused by exposure to asbestos the greater the exposure the greater the risk as of 2013 about 125 million people have been exposed to asbestos at work high rates of disease occur in people who mine asbestos produce products from asbestos work with asbestos products live with asbestos workers or work in buildings containing asbestos often it takes around 40 years for the disease to begin washing the clothing of someone who worked with asbestos also increases the risk other risk factors include genetics and infection with the simian virus 40 the diagnosis may be suspected based on chest x ray and ct scan findings and is confirmed by either examining fluid produced by the cancer or by a tissue biopsy of the cancer prevention centers around reducing exposure to asbestos treatment often includes surgery radiation therapy and chemotherapy a procedure known as pleurodesis which involves using substances such as talc to scar together the pleura may be used to prevent more fluid from building up around the lungs chemotherapy often includes the medications cisplatin and pemetrexed the percentage of people that survive five years following diagnosis is on average 8 in the united states in 2013 about 50 000 people had mesothelioma and 34 000 died from the disease rates of mesothelioma vary in different areas of the world rates are higher in australia and great britain and lower in japan it occurs in about 3 000 people per year in the united states it occurs more often in males than females rates of disease have increased since the 1950 s diagnosis typically occurs after the age of 65 and most deaths occur around 70 years old the disease was rare before the commercial use of asbestos
in software architecture a messaging pattern is a network oriented architectural pattern which describes how two different parts of a message passing system connect and communicate with each other in telecommunications a message exchange pattern mep describes the pattern of messages required by a communications protocol to establish or use a communication channel there are two major message exchange patterns — a request – response pattern and a one way pattern for example http is a request – response pattern protocol and udp is a one way pattern
meta learning is a subfield of machine learning where automatic learning algorithms are applied on meta data about machine learning experiments although different researchers hold different views as to what the term exactly means see below the main goal is to use such meta data to understand how automatic learning can become flexible in solving different kinds of learning problems hence to improve the performance of existing learning algorithms flexibility is very important because each learning algorithm is based on a set of assumptions about the data its inductive bias this means that it will only learn well if the bias matches the data in the learning problem a learning algorithm may perform very well on one learning problem but very badly on the next from a non expert point of view this poses strong restrictions on the use of machine learning or data mining techniques since the relationship between the learning problem often some kind of database and the effectiveness of different learning algorithms is not yet understood by using different kinds of meta data like properties of the learning problem algorithm properties like performance measures or patterns previously derived from the data it is possible to select alter or combine different learning algorithms to effectively solve a given learning problem critiques of meta learning approaches bear a strong resemblance to the critique of metaheuristic which can be said to be a related problem
metabolic acidosis is a condition that occurs when the body produces excessive quantities of acid or when the kidneys are not removing enough acid from the body if unchecked metabolic acidosis leads to acidemia i e blood ph is low less than 7 35 due to increased production of hydrogen ions by the body or the inability of the body to form bicarbonate hco 3 − in the kidney its causes are diverse and its consequences can be serious including coma and death together with respiratory acidosis it is one of the two general causes of acidemia
metabolic alkalosis is a metabolic condition in which the ph of tissue is elevated beyond the normal range 7 35 7 45 this is the result of decreased hydrogen ion concentration leading to increased bicarbonate or alternatively a direct result of increased bicarbonate concentrations
metabolic bone disease is an umbrella term referring to abnormalities of bones caused by a broad spectrum of disorders most commonly these disorders are caused by abnormalities of minerals such as calcium phosphorus magnesium or vitamin d leading to dramatic clinical disorders that are commonly reversible once the underlying defect has been treated these disorders are to be differentiated from a larger group of genetic bone disorders where there is a defect in a specific signaling system or cell type that causes the bone disorder there may be overlap for example genetic or hereditary hypophosphatemia may cause the metabolic bone disorder osteomalacia although there is currently no treatment for the genetic condition replacement of phosphate often corrects or improves the metabolic bone disorder
a metabolic disorder can happen when abnormal chemical reactions in the body alter the normal metabolic process it can also be defined as inherited single gene anomaly most of which are autosomal recessive
metabolic syndrome sometimes known by is a clustering of at least three of the five unfold into nine combination following medical conditions abdominal central obesity cf tofi elevated blood pressure elevated fasting plasma glucose high serum triglycerides low high density lipoprotein hdl levels metabolic syndrome is associated with the risk of developing cardiovascular disease and type 2 diabetes some studies have shown the prevalence in the usa to be an estimated 34 of the adult population and the prevalence increases with age insulin resistance metabolic syndrome and prediabetes are closely related to one another and have overlapping aspects the syndrome is thought to be caused by an underlying disorder of energy utilization and storage the cause of the syndrome is an area of ongoing medical research
metabolically healthy obesity or metabolically healthy obesity mho is a debatable medical condition characterized by obesity which does not produce metabolic complications
metachondromatosis is an autosomal dominantincompletely penetrant skeletal disorder affecting the growth of bones leading to multiple enchondromas and osteochondromas this tumor syndrome affects mainly tubular bones though it can also involve the vertebrae small joints and flat bones
metachromatic leukodystrophy mld also called arylsulfatase a deficiency is a lysosomal storage disease which is commonly listed in the family of leukodystrophies as well as among the sphingolipidoses as it affects the metabolism of sphingolipids leukodystrophies affect the growth and or development of myelin the fatty covering which acts as an insulator around nerve fibers throughout the central and peripheral nervous systems mld involves cerebroside sulfate accumulation metachromatic leukodystrophy like most enzyme deficiencies has an autosomal recessive inheritance pattern
metageria is a cutaneous condition characterized by premature aging
metagonimiasis is a disease caused by an intestinal trematode most commonly metagonimus yokagawai but sometimes by m takashii or m miyatai the metagonimiasis causing flukes are one of two minute flukes called the heterophyids metagonimiasis was described by katsurasa in 1911 – 1913 when he first observed eggs of m yokagawai in feces date is disputed in various studies m takahashii was described later first by suzuki in 1930 and then m miyatai was described in 1984 by saito stained adult fluke causing metagonimiasis
in chemistry metal catalysed hydroboration is a reaction used in organic synthesis it is one of several examples of homogeneous catalysis
a metal centered cycloaddition is a subtype of the more general class of cycloaddition reactions in such reactions two or more unsaturated molecules unite directly to form a ring incorporating a metal bonded to one or more of the molecules cycloadditions involving metal centers are a staple of organic and organometallic chemistry and are involved in many industrially valuable synthetic processes there are two general types of metal centered cycloaddition reactions those in which the metal is incorporated into the cycle a metallocycle and those in which the metal is external to the cycle these can be further divided into true cycloadditions those that take place in a concerted fashion and formal cycloadditions those that take place in a stepwise fashion beyond that they are classified by the number of atoms contributed to the cycle by each of the participants for example olefin metathesis using a grubbs catalyst typically involves a reversible 2 2 cycloaddition a ruthenium alkylidene and an alkene or alkyne react to form a metallocycle
metal chinese 金 pinyin jīn the fourth phase of the chinese philosophy of wu xing is the decline of the matter or the matter s decline stage metal is yin in character its motion is inwards and its energy is contracting it is associated with the autumn the west old age the planet venus the color white dry weather and the white tiger bai hu in four symbols the archetypal metals are silver and gold
metal fume fever also known as brass founders ague brass shakes zinc shakes galvie flu metal dust fever or monday morning fever is an illness primarily caused by exposure to certain fumes workers breathe in fumes from chemicals such as zinc oxide zno or magnesium oxide mgo which are themselves created by heating or welding certain metals particularly galvanized steel other common sources are fuming silver gold platinum chromium from stainless steel nickel arsenic manganese beryllium cadmium cobalt copper lead selenium and zinc welders are commonly exposed to the substances that cause metal fume fever from the base metal plating or filler brazing and soldering a type of metal work in which only the filler is melted can also cause metal poisoning from lead zinc copper or cadmium in the filler metal in extreme cases cadmium present in some older silver solder alloys can cause loss of consciousness within a matter of minutes
metal toxicity or metal poisoning is the toxic effect of certain metals in certain forms and doses on life some metals are toxic when they form poisonous soluble compounds certain metals have no biological role i e are not essential minerals or are toxic when in a certain form in the case of lead any measurable amount may have negative health effects often heavy metals are thought as synonymous but lighter metals may also be toxic in certain circumstances such as beryllium and lithium not all heavy metals are particularly toxic and some are essential such as iron the definition may also include trace elements when considered in abnormally high toxic doses an option for treatment of metal poisoning may be chelation therapy which is a technique which involves the administration of chelation agents to remove metals from the body toxic metals sometimes imitate the action of an essential element in the body interfering with the metabolic process to cause illness many metals particularly heavy metals are toxic but some heavy metals are essential and some such as bismuth have a low toxicity most often the definition of toxic metals includes at least cadmium manganese lead mercury and the radioactive metals metalloids arsenic polonium may be included in the definition radioactive metals have both radiological toxicity and chemical toxicity metals in an oxidation state abnormal to the body may also become toxic chromium iii is an essential trace element but chromium vi is a carcinogen toxicity is a function of solubility insoluble compounds as well as the metallic forms often exhibit negligible toxicity the toxicity of any metal depends on its ligands in some cases organometallic forms such as methylmercury and tetraethyl lead can be extremely toxic in other cases organometallic derivatives are less toxic such as the cobaltocenium cation decontamination for toxic metals is different from organic toxins because toxic metals are elements they cannot be destroyed toxic metals may be made insoluble or collected possibly by the aid of chelating agents alternatively they can be diluted into a sufficiently large reservoir such as the sea because immediate toxicity is a function of concentration rather than amount however bioaccumulation has the potential to reverse this toxic metals can bioaccumulate in the body and in the food chain therefore a common characteristic of toxic metals is the chronic nature of their toxicity this is particularly notable with radioactive heavy metals such as radium which imitates calcium to the point of being incorporated into human bone although similar health implications are found in lead or mercury poisoning the exceptions to this are barium and aluminium which can be removed efficiently by the kidneys
metalation metallation is a chemical reaction which results in a metal atom beingattached to a usually organic molecule lithium metal in contact with an organohalide lithiates the organic molecule and gives the organolithium reagent and lithium halide magnesium similarly metalates organohalides to give grignard reagents protons on a molecule that are acidic even only slightly can be exchanged for a metal by a suitable butyllithium reagent mixture transmetalation involves the exchange of two metals between organic molecules for example transmetalations can occur when reacting an organolithium reagent with a metal salt
metallosis is the putative medical condition involving deposition and build up of metal debris in the soft tissues of the body metallosis has been hypothesized to occur when metallic components in medical implants specifically joint replacements abrade against one another metallosis has also been observed in some patients either sensitive to the implant or for unknown reasons even in the absence of malpositioned prosthesis though rare metallosis has been observed at an estimated incidence of 5 of metal joint implant patients over the last 40 years women may be at slightly higher risk than men if metallosis occurs it may involve the hip and knee joints the shoulder wrist or elbow joints the abrasion of metal components may cause metal ions to be solubilized the hypothesis that the immune system identifies the metal ions as foreign bodies and inflames the area around the debris may be incorrect because of the small size of metal ions may prevent them from becoming haptens poisoning from metallosis is rare but cobaltism is an established health concern the involvement of the immune system in this putative condition has also been theorized but has never been proven purported symptoms of metallosis generally include pain around the site of the implant pseudotumors a mass of inflamed cells that resembles a tumor but is actually collected fluids and a noticeable rash that indicates necrosis the damaged and inflamed tissue can also contribute to loosening the implant or medical device metallosis can cause dislocation of non cemented implants as the healthy tissue that would normally hold the implant in place is weakened or destroyed metallosis has been demonstrated to cause osteolysis women those who are small in stature and the obese are at greater risk for metallosis because their body structure causes more tension on the implant quickening the abrasion of the metal components and the subsequent build up of metallic debris
metamagnetism is a sudden often dramatic increase in the magnetization of a material with a small change in an externally applied magnetic field the metamagnetic behavior may have quite different physical causes for different types of metamagnets some examples of physical mechanisms leading to metamagnetic behavior are 1 itinerant metamagnetism exchange splitting of the fermi surface in a paramagnetic system of itinerant electrons causes an energetically favorable transition to bulk magnetization near the transition to a ferromagnet or other magnetically ordered state 2 antiferromagnetic transition field induced spin flips in antiferromagnets cascade at a critical energy determined by the applied magnetic field depending on the material and experimental conditions metamagnetism may be associated with a first order phase transition a continuous phase transition at a critical point classical or quantum or crossovers beyond a critical point that do not involve a phase transition at all these wildly different physical explanations sometimes lead to confusion as to what the term metamagnetic is referring in specific cases
in biology metamerism is the phenomenon of having a linear series of body segments fundamentally similar in structure though not all such structures are entirely alike in any single life form because some of them perform special functions in animals metameric segments are referred to as somites or metameres in plants they are referred to as metamers or more concretely phytomers
a metamorphic reaction is a chemical reaction that takes place during the geological process of metamorphism wherein one assemblage of minerals is transformed into a second assemblage which is stable under the new temperature pressure conditions resulting in the final stable state of the observed metamorphic rock examples would include the production of talc under varied metamorphic conditions serpentine carbon dioxide → talc magnesite waterchlorite quartz → kyanite talc water
metanephric adenoma ma is a rare benign tumour of the kidney that can have a microscopic appearance similar to a nephroblastoma wilms tumours or a papillary renal cell carcinoma it should not be confused with the pathologically unrelated yet similar sounding mesonephric adenoma
metaphyseal dysplasia also known as pyle s disease pyle s syndrome pyle cohn syndrome and bakwin krida syndrome is a rare disease in which the outer part of the shafts of long bones is thinner than normal and there is an increased chance of fractures
metaplasia greek change in form is the reversible replacement of one differentiated cell type with another mature differentiated cell type the change from one type of cell to another may generally be a part of normal maturation process or caused by some sort of abnormal stimulus in simplistic terms it is as if the original cells are not robust enough to withstand the new environment and so they change into another type more suited to the new environment if the stimulus that caused metaplasia is removed or ceases tissues return to their normal pattern of differentiation metaplasia is not synonymous with dysplasia and is not directly considered carcinogenic it is also contrasted with heteroplasia which is the abnormal growth of cytologic and histologic elements without a stimulus
metaplastic carcinoma is cancer that begins in cells that have changed into another cell type for example a squamous cell of the esophagus changing to resemble a cell of the stomach in some cases metaplastic changes alone may mean there is an increased chance of cancer developing at the site metaplastic carcinoma is a relatively uncommon type of cancer with treatment generally similar to that of invasive ductal carcinoma of no special type
metasomatism is the chemical alteration of a rock by hydrothermal and other fluids it is the replacement of one rock by another of different minerological and chemical composition the minerals which compose the rocks are dissolved and new mineral formations are deposited in their place dissolution and deposition occur simultaneously and the rock remains solid synonyms to the word metasomatism are metasomatose and metasomatic process the word metasomatose can also be used as a name for specific varieties of metasomatism for example mg metasomatose and na metasomatose metasomatism can occur via the action of hydrothermal fluids from an igneous or metamorphic source in the igneous environment metasomatism creates skarns greisen and may affect hornfels in the contact metamorphic aureole adjacent to an intrusive rock mass in the metamorphic environment metasomatism is created by mass transfer from a volume of metamorphic rock at higher stress and temperature into a zone with lower stress and temperature with metamorphic hydrothermal solutions acting as a solvent this can be envisaged as the metamorphic rocks within the deep crust losing fluids and dissolved mineral components as hydrous minerals break down with this fluid percolating up into the shallow levels of the crust to chemically change and alter these rocks this mechanism implies that metasomatism is open system behaviour which is different from classical metamorphism which is the in situ mineralogical change of a rock without appreciable change in the chemistry of the rock because metamorphism usually requires water in order to facilitate metamorphic reactions metasomatism and metamorphism nearly always occur together further because metasomatism is a mass transfer process it is not restricted to the rocks which are changed by addition of chemical elements and minerals or hydrous compounds in all cases to produce a metasomatic rock some other rock is also metasomatised if only by dehydration reactions with minimal chemical change this is best illustrated by gold ore deposits which are the product of focused concentration of fluids derived from many cubic kilometres of dehydrated crust into thin often highly metasomatised and altered shear zones and lodes the source region is often largely chemically unaffected compared to the highly hydrated altered shear zones but both must have undergone complementary metasomatism metasomatism is more complicated in the earth s mantle because the composition of peridotite at high temperatures can be changed by infiltration of carbonate and silicate melts and by carbon dioxide rich and water rich fluids as discussed by luth 2003 metasomatism is thought to be particularly important in changing the composition of mantle peridotite below island arcs as water is driven out of ocean lithosphere during subduction metasomatism has also been considered critical for enriching source regions of some silica undersaturated magmas carbonatite melts are often considered to have been responsible for enrichment of mantle peridotite in incompatible elements
metastability in electronics is the ability of a digital electronics system to persist for an unbounded time in an unstable equilibrium or metastable state in metastable states the circuit may be unable to settle into a stable 0 or 1 logic level within the time required for proper circuit operation as a result the circuit can act in unpredictable ways and may lead to a system failure sometimes referred to as a glitch metastability is an instance of buridan s paradox metastable states are inherent features of asynchronous digital systems and of systems with more than one independent clock domain in self timed asynchronous systems arbiters are designed to allow the system to proceed only after the metastability has resolved so the metastability is a normal condition not an error condition in synchronous systems with asynchronous inputs synchronizers are designed to make the probability of a synchronization failure acceptably small metastable states are avoidable in fully synchronous systems when the input setup and hold time requirements on flip flops are satisfied
metastasis is the spread of a cancer or other disease from one organ or part of the body to another without being directly connected with it the new occurrences of disease thus generated are referred to as metastases mets cancer occurs after a single cell in a tissue is progressively genetically damaged to produce cells with uncontrolled proliferation this uncontrolled proliferation by mitosis produces a primary heterogeneic tumour the cells which constitute the tumor eventually undergo metaplasia followed by dysplasia then anaplasia resulting in a malignant phenotype this malignancy allows for invasion into the circulation followed by invasion to a second site for tumorigenesis some cancer cells acquire the ability to penetrate the walls of lymphatic and or blood vessels after which they are able to circulate through the bloodstream circulating tumor cells to other sites and tissues in the body this process is known respectively as lymphatic or hematogenous spread after the tumor cells come to rest at another site they re penetrate the vessel or walls and continue to multiply eventually forming another clinically detectable tumor this new tumor is known as a metastatic or secondary tumor metastasis is one of the hallmarks of cancer distinguishing it from benign tumors most neoplasms can metastasize although in varying degrees e g basal cell carcinoma rarely metastasize when tumor cells metastasize the new tumor is called a secondary or metastatic tumor and its cells are similar to those in the original or primary tumor this means for example that if breast cancer metastasizes to the lungs the secondary tumor is made up of abnormal breast cells not of abnormal lung cells the tumor in the lung is then called metastatic breast cancer not lung cancer metastasis is a key element in cancer staging systems such as the tnm staging system where it represents the m in overall stage grouping metastasis places a cancer in stage iv the possibilities of curative treatment are greatly reduced or often entirely removed when a cancer has metastasized
metastatic calcification is deposition of calcium salts in otherwise normal tissue because of elevated serum levels of calcium which can occur because of deranged metabolism as well as increased absorption or decreased excretion of calcium and related minerals as seen in hyperparathyroidism in contrast dystrophic calcification is caused by abnormalities or degeneration of tissues resulting in mineral deposition though blood levels of calcium remain normal these differences in pathology also mean that metastatic calcification is often found in many tissues throughout a person or animal whereas dystrophic calcification is localized metastatic calcification can occur widely throughout the body but principally affects the interstitial tissues of the vasculature kidneys lungs and gastric mucosa for the latter three acid secretions or rapid changes in ph levels contribute to the formation of salts
metastatic calcinosis cutis is a cutaneous condition characterized by calcification of the skin resulting from the deposition of calcium and phosphorus and associated with an internal malignancy
a liver metastasis is a malignant tumor in the liver that has spread from another organ affected by cancer the liver is a common site for metastatic disease because of its rich dual blood supply the liver receives blood via the hepatic artery and portal vein metastatic tumors in the liver are 20 times more common than primary tumors in 50 of all cases the primary tumor is of the gastrointestinal tract other common sites include the breast ovaries bronchus and kidney tumor emboli entering the sinusoids through the liver blood supply appear to be physically obstructed by the kupffer cells but if tumor emboli are larger they tend to become lodged in the portal venous branches
metatarsalgia literally metatarsal pain and colloquially known as a stone bruise is a general term used to refer to any painful foot condition affecting the metatarsal region of the foot this is a common problem that can affect the joints and bones of the metatarsals metatarsalgia is most often localized to the first metatarsal head – the ball of the foot just behind the big toe there are two small sesamoid bones under the first metatarsal head the next most frequent site of metatarsal head pain is under the second metatarsal this can be due to either too short a first metatarsal bone or to hypermobility of the first ray – metatarsal bone and medial cuneiform bone behind it – both of which result in excess pressure being transmitted into the second metatarsal head
a metatarsophalangeal joint sprain is an injury to the connective tissue between the foot and one of the toes when the big toe is involved it is known as turf toe
meteorite weathering is the terrestrial alteration of a meteorite most meteorites date from the oldest times in the solar system and are by far the oldest material available on our planet despite their age they are vulnerable to the terrestrial environment water chlorine and oxygen attack meteorites as soon they reach the ground
meteoropathy from greek meteora celestial phenomena and pathos feeling pain suffering is a physical condition or symptom associated with weather conditions such as humidity temperature or pressure someone subject to meteoropathy is called meteoropathic meteoropathy is different from historical conceptions of air causing diseases and strongly influencing people s sense of well being see miasma theory of disease there appear to be significant and measurable correlations between particular atmospherical events such as a sudden increase in humidity and temperature and the onset of disease such as stroke a few researchers found significant effect on mood correlated with the weather especially with regards to humidity a component of weather not always measured humidity temperature and hours of sunshine had the greatest effect on mood high levels of humidity lowered scores on concentration while increasing reports of sleepiness rising temperatures lowered anxiety and skepticism mood scores the number of hours of sunshine was found to predict optimism scores significantly as the number of hours of sunshine increased optimism scores also increased mood scores on the depression and anxiety scales were not predicted by any weather variable pleasant weather higher temperature or barometric pressure was related to higher mood better memory and ‘ ‘ broadened ’ ’ cognitive style during the spring as time spent outside increased the same relationships between mood and weather were not observed during other times of year and indeed hotter weather was associated with lower mood in the summer
a meteotsunami or meteorological tsunami is a tsunami like wave of meteorological origin meteotsunamis are generated when rapid changes in barometric pressure cause the displacement of a body of water in contrast to ordinary impulse type tsunami sources a traveling atmospheric disturbance normally interacts with the ocean over a limited period of time from several minutes to several hours tsunamis and meteotsunamis are otherwise similar enough that it can be difficult to distinguish one from the other as in cases where there is a tsunami wave but there are no seismic records of an earthquake only about 3 of historical tsunami events from 2000 bc through 2014 are known to have meteorological origins although their true prevalence may be considerably higher than this because 10 of historical tsunamis have unknown origins tsunami events in the past are often difficult to validate and meteotsunamis may have previously been misclassified as seiche waves meteotsunamis are restricted to local effects because they lack the energy available to significant seismic tsunami however when they are amplified by resonance they can be hazardous a meteotsunami that struck nagasaki bay on 31 march 1979 achieved a maximum wave height of 5 meters there were three fatalities a three meter wave that hit the chicago waterfront in 1954 swept people off of piers drowning seven in some parts of the world they are common enough to have local names rissaga catalan milghuba maltese marrobbio italian abiki japanese šćiga croatian some bodies of water are more susceptible than others including anywhere that the natural resonance frequency matches that of the waves such as in long and narrow bays particularly where the inlet is aligned with the oncoming wave examples of particularly susceptible areas include nagasaki bay the eastern adriatic sea and the western mediterranean
methaemalbuminaemia is a clinical condition that can be caused by severe intravascular haemolysis or acute haemorrhagic pancreatitis this can be due to proteolytic breakdown of haemoglobin to form both haem and methaem methaem combines with blood plasma albumin to form methemalbumin which is found in trace amount in the blood bleeding into the abdominal cavity is another known cause of methaemalbuminaemia methaemalbumin in blood is detected by carrying out a test known as schumm test which is a spectroscopic identification on addition of ammonium sulphide
methanol toxicity is poisoning from methanol symptoms may include a decreased level of consciousness poor coordination vomiting abdominal pain and a specific smell on the breath decreased vision may start as early as twelve hours after exposure long term outcomes may include blindness and kidney failure toxicity and death may occur even after drinking a small amount methanol poisoning most commonly occurs following the drinking of windshield washer fluid this may be accidental or done purposefully in an attempt to cause death toxicity may also rarely occur through skin exposure or breathing in the fumes when methanol is broken down by the body it results in formaldehyde formic acid and formate which cause much of the toxicity the diagnosis may be suspected when there is acidosis or an increased osmol gap and confirmed by directly measuring blood levels other conditions that can produce similar symptoms include infections exposure to other toxic alcohols serotonin syndrome and diabetic ketoacidosis early treatment increases the chance of a good outcome treatment consists of stabilizing the person followed by the use of an antidote the preferred antidote is fomepizole with ethanol used if this is not available hemodialysis may also be used in those where there is organ damage or a high degree of acidosis other treatments may include sodium bicarbonate folate and thiamine outbreaks have occurred due to contamination of drinking alcohol this is more common in the developing world in 2013 more than 1700 cases occurred in the united states those affected are often adults and male outcomes may be good with early treatment toxicity to methanol has been described as early as 1856
methemoglobinemia or methaemoglobinaemia is a disorder characterized by the presence of a higher than normal level of methemoglobin methb i e ferric fe 3 rather than ferrous fe 2 haemoglobin in the blood methemoglobin is a form of hemoglobin that contains ferric fe 3 iron and has a decreased ability to bind oxygen however the ferrous iron has an increased affinity for bound oxygen the binding of oxygen to methemoglobin results in an increased affinity of oxygen to the three other heme sites that are still ferrous within the same tetrameric hemoglobin unit this leads to an overall reduced ability of the red blood cell to release oxygen to tissues with the associated oxygen – hemoglobin dissociation curve therefore shifted to the left when methemoglobin concentration is elevated in red blood cells tissue hypoxia can occur
methotrexate induced papular eruption appears in patients being treated with methotrexate such as those with rheumatic disease presenting with erythematous indurated papules usually located on the proximal extremities it has been suggested that it may represent a cutaneous small vessel vasculitis
methylmalonic acidemia mma also called methylmalonic aciduria is an autosomal recessive metabolic disorder it is a classical type of organic acidemia the result of this condition is the inability to properly digest specific fats and proteins which in turn leads to a buildup of a toxic level of methylmalonic acid in the blood methylmalonic acidemia stems from several genotypes all forms of the disorder usually diagnosed in the early neonatal period presenting progressive encephalopathy and secondary hyperammonemia the disorder can result in death if undiagnosed or left untreated it is estimated that this disorder has a frequency of 1 in 48 000 births though the high mortality rate in diagnosed cases make exact determination difficult methylmalonic acidemias are found with an equal frequency across ethnic boundaries
methylmalonyl coa mutase is a mitochondrial homodimer apoenzyme ec 5 4 99 2 that focuses on the catalysis of methylmalonyl coa to succinyl coa the enzyme is bound to adenosylcobalamin a hormonal derivative of vitamin b 12 in order to function methylmalonyl coa mutase deficiency is caused by genetic defect in the mut gene responsible for encoding the enzyme deficiency in this enzyme accounts for 60 of the cases of methylmalonic acidemia
metophyma is cushion like swellings on the forehead above the saddle of the nose
at birth the frontal bone contains two portions separated by the metopic frontal suture metopism is the condition of having a persistent metopic suture metopic suture is regularly obliterated except at its lower part by the eighth year but infrequently persists throughout life there is no single proven cause of metopism the occurrence is from mild to serious situations visional learning and behavioral problems may happen in serious metopism some don t need any medical treatment surgery is a successful approach for those who need it treatment teams include neurosurgeons plastic surgeons neurologists oral and maxillofacial surgeons audiologists neuroscience nursing professionals speech therapists physical therapists dentist otolaryngologists ophthalmologists psychiatrists psychologists and social workers
the metric expansion of space is the increase of the distance between two distant parts of the universe with time it is an intrinsic expansion whereby the scale of space itself changes this is different from other examples of expansions and explosions in that as far as observations can ascertain it is a property of the entirety of the universe rather than a phenomenon that can be contained and observed from the outside metric expansion is a key feature of big bang cosmology is modeled mathematically with the flrw metric and is a generic property of the universe we inhabit however the model is valid only on large scales roughly the scale of galaxy clusters and above at smaller scales matter has become bound together under the influence of gravitational attraction and such things do not expand at the metric expansion rate as the universe ages as such the only galaxies receding from one another as a result of metric expansion are those separated by cosmologically relevant scales larger than the length scales associated with the gravitational collapse that are possible in the age of the universe given the matter density and average expansion rate at the end of the early universe s inflationary period all the matter and energy in the universe was set on an inertial trajectory consistent with the equivalence principle and einstein s general theory of relativity and this is when the precise and regular form of the universe s expansion had its origin that is matter in the universe is separating because it was separating in the past due to the inflaton field according to measurements the universe s expansion rate was decelerating until about 5 billion years ago due to the gravitational attraction of the matter content of the universe after which time the expansion began accelerating the source of this acceleration is currently unknown physicists have postulated the existence of dark energy appearing as a cosmological constant in the simplest gravitational models as a way to explain the acceleration according to the simplest extrapolation of the currently favored cosmological model known as λcdm this acceleration becomes more dominant into the future while special relativity prohibits objects from moving faster than light with respect to a local reference frame where spacetime can be treated as flat and unchanging it does not apply to situations where spacetime curvature or evolution in time become important these situations are described by general relativity which allows the separation between two distant objects to increase faster than the speed of light although the definition of distance here is somewhat different to that used in an inertial frame the definition of distance used here is the summation or integration of local comoving distances all done at constant local proper time for example galaxies that are more than the hubble radius approximately 4 5 gigaparsecs or 14 7 billion light years away from us have a recession speed that is faster than the speed of light visibility of these objects depends on the exact expansion history of the universe light that is emitted today from galaxies beyond the cosmological event horizon about 5 gigaparsecs or 16 billion light years will never reach us although we can still see the light that these galaxies emitted in the past because of the high rate of expansion it is also possible for a distance between two objects to be greater than the value calculated by multiplying the speed of light by the age of the universe these details are a frequent source of confusion among amateurs and even professional physicists due to the non intuitive nature of the subject and what has been described by some as careless choices of wording certain descriptions of the metric expansion of space and the misconceptions to which such descriptions can lead are an ongoing subject of discussion in the realm of pedagogy and communication of scientific concepts in june 2016 nasa and esa scientists reported that the universe was found to be expanding 5 to 9 faster than thought earlier based on studies using the hubble space telescope
in graph theory the metric k center or metric facility location problem is a combinatorial optimization problem studied in theoretical computer science given n cities with specified distances one wants to build k warehouses in different cities and minimize the maximum distance of a city to a warehouse in graph theory this means finding a set of k vertices for which the largest distance of any point to its closest vertex in the k set is minimum the vertices must be in a metric space or in other words a complete graph that satisfies the triangle inequality
in the mathematical field of differential geometry a metric tensor is a type of function which takes as input a pair of tangent vectors v and w at a point of a surface or higher dimensional differentiable manifold and produces a real number scalar g v w in a way that generalizes many of the familiar properties of the dot product of vectors in euclidean space in the same way as a dot product metric tensors are used to define the length of and angle between tangent vectors through integration the metric tensor allows one to define and compute the length of curves on the manifold a metric tensor is called positive definite if it assigns a positive value g v v 0 to every nonzero vector v a manifold equipped with a positive definite metric tensor is known as a riemannian manifold on a riemannian manifold the curve connecting two points that locally has the smallest length is called a geodesic and its length is the distance that a passenger in the manifold needs to traverse to go from one point to the other equipped with this notion of length a riemannian manifold is a metric space meaning that it has a distance function d p q whose value at a pair of points p and q is the distance from p to q conversely the metric tensor itself is the derivative of the distance function taken in a suitable manner thus the metric tensor gives the infinitesimal distance on the manifold while the notion of a metric tensor was known in some sense to mathematicians such as carl gauss from the early 19 th century it was not until the early 20 th century that its properties as a tensor were understood by in particular gregorio ricci curbastro and tullio levi civita who first codified the notion of a tensor the metric tensor is an example of a tensor field the components of a metric tensor in a coordinate basis take on the form of a symmetric matrix whose entries transform covariantly under changes to the coordinate system thus a metric tensor is a covariant symmetric tensor from the coordinate independent point of view a metric tensor is defined to be a nondegenerate symmetric bilinear form on each tangent space that varies smoothly from point to point
metritis is inflammation of the wall of the uterus whereas endometritis is inflammation of the functional lining of the uterus called the endometrium the term pelvic inflammatory disease pid is often used for metritis
metrorrhagia metro womb rrhagia excessive flow is uterine bleeding at irregular intervals particularly between the expected menstrual periods in some women menstrual spotting between periods occurs as a normal and harmless part of ovulation some women experience acute mid cycle abdominal pain around the time of ovulation sometimes referred to by the german term for this phenomenon mittelschmerz this may also occur at the same time as menstrual spotting the term breakthrough bleeding or breakthrough spotting is usually used for women using hormonal contraceptives such as iuds or oral contraceptives in which it refers to bleeding or spotting between any expected withdrawal bleedings or bleeding or spotting at any time if none is expected if spotting continues beyond the first three cycles of oral contraceptive use a woman should have her prescription changed to a pill containing either more estrogen or more progesterone besides the aforementioned physiologic forms metrorrhagia may also represent abnormal uterine bleeding and be a sign of an underlying disorder such as hormone imbalance endometriosis uterine fibroids uterine cancer or vaginal cancer if the bleeding is repeated and heavy it can cause significant iron deficiency anemia
metsänpeitto lit forest cover is a phenomenon found in finnish folklore it was used to describe people or domestic animals who went missing in nature for unexplained reasons people covered by forest were described as not being able to recognize the terrain around them even if they were on familiar grounds in other cases they might have walked endlessly through unfamiliar terrain or were rendered completely paralyzed unable to move or speak unnatural silence devoid of the sounds of nature was also common people or animals under the influence of the phenomenon were described as becoming either completely invisible to other people or looking like part of the nature around them like a rock in one story a man had been looking for a missing cow for days when he finally gave up and returned to his work the first tree stump he struck with his axe transformed back into his cow the cause behind metsänpeitto was usually credited to maahinens who were small humanoid creatures living underground usually translated as gnomes some people managed to free themselves from metsänpeitto by their own means for example by turning their jacket inside out by switching their shoes to the wrong feet or by looking between their own legs this was because of the idea that everything was topsy turvy in the lands of the maahinens some were released seemingly without reason others only after being sought after by a shaman some were never seen again metsänpeitto greatly resembles kamikakushi or spiriting away found in japanese folklore
mevalonate kinase deficiency also called mevalonic aciduria and hyper immunoglobin d syndrome is an autosomal recessive metabolic disorder that disrupts the biosynthesis of cholesterol and isoprenoids it is characterized by an elevated level of immunoglobin d in the blood the enzyme is involved in biosynthesis of cholesterols and isoprenoids the enzyme is necessary for the conversion of mevalonate to mevalonate 5 phosphate in the presence of mg 2 harper ’ s biochemistry manual mevalonate kinase deficiency causes the accumulation of mevalonate in urine and hence the activity of the enzyme is again reduced mevalonate kinase deficiency it was first described as hids in 1984
the meyer – schuster rearrangement is the chemical reaction described as an acid catalyzed rearrangement of secondary and tertiary propargyl alcohols to α β unsaturated ketones if the alkyne group is internal and α β unsaturated aldehydes if the alkyne group is terminal reviews have been published by swaminathan and narayan vartanyan and banbanyan and engel and dudley the last of which describes ways to promote the meyer – schuster rearrangement over other reactions available to propargyl alcohols the meyer schuster rearrangement when catalyzed by base the reaction is called the favorskii reaction
in mathematics the mice problem is a problem in which a number of mice or insects dogs missiles etc are placed at the corners of a regular polygon each mouse begins to move towards its immediate neighbour clockwise or anticlockwise it must be determined when the mice meet the most common version has the mice starting at the corners of a unit square moving at unit speed in this case they meet after a time of one unit because the distance between two neighboring mice always decreases at a speed of one unit more generally for a regular polygon of n sides the distance between neighboring mice decreases at a speed of 1 − cos 2 π n so they meet after a time of 1 1 − cos 2 π n
the michaelis – arbuzov reaction also called the arbuzov reaction is the chemical reaction of a trialkyl phosphite and an alkyl halide to form a phosphonate the michaelis – arbuzov reaction the reaction was discovered by august michaelis in 1898 and greatly explored by aleksandr arbuzov soon thereafter this reaction is widely used for the synthesis of various phosphonates phosphinates and phosphine oxides several reviews have been published the reaction also occurs for coordinated phosphite ligands as illustrated by the demethylation of c 5 h 5 co ch 3 o 3 p 3 2 to give c 5 h 5 co ch 3 o 2 po 3 − which is called the klaui ligand
the michaelis – becker reaction is the reaction of a hydrogen phosphonate with a base followed by a nucleophilic substitution of phosphorus on an haloalkane to afford an alkyl phosphonate yields of this reaction are often lower than the corresponding michaelis arbuzov reaction
the michelangelo phenomenon is a phenomenon observed by psychologists in which interdependent individuals influence and sculpt each other opposite of blueberry phenomenon in which interdependent individuals bring out the worst qualities in each other over time the michelangelo effect causes individuals to develop toward what they themselves consider as their ideal selves for example in a close relationship because john affirms mary s ideals mary increasingly comes to resemble her ideal self the phenomenon was named after the italian renaissance painter sculptor architect poet and engineer michelangelo 1475 – 1564 who is said to have thought of sculpting as a process of revealing and uncovering the figures hidden in stone the term was introduced in 1999 by the us psychologist stephen michael drigotas et al the michelangelo phenomenon is related to the looking glass self concept introduced by charles horton cooley in his 1902 work human nature and the social order and is referred to in contemporary marital therapy recent popular work in couples therapy and conflict resolution points to the importance of the michelangelo phenomenon diana kirschner reported that the phenomenon was common among couples reporting high levels of marital satisfaction
michelin tire baby syndrome also known as folded skin with scarring is characterized by multiple symmetric circular skin creases or bands on the forearms lower legs and often the neck that are present at birth the creases disappear later in life but it is a dangerous skin disease as it resides in the body rest of life it can lead to death they are reminiscent of these of bibendum the mascot of the tire manufacturer michelin hence the name of the syndrome associated abnormalities vary and may include facial dysmorphism upslanting palpebral fissures hypertelorism cleft palate genital anomalies mild developmental delay ureterocele smooth muscle hamartoma nevus lipomatosus laron syndrome dwarfism with high growth hormone and low somatomedin activity and other defects it was originally described by ross in 1969 twenty cases of this disorder have been reported
michels caskey syndrome is a rare disorder that combines spinal and skeletal abnormalities especially of the thumbs with abnormal or absent female reproductive organs examples include the absence of a cervix and upper vagina or abnormalities of the uterus or vagina symptoms may also include scoliosis and primary amenorrhea synonyms include mullerian aplasia with hypoplastic thumbs hypoplastic thumb mullerian aplasia and mullerian aplasia with unilateral hypoplasia of the thumbs and skeletal spine deformities
michels syndrome is a syndrome characterised by intellectual disability craniosynostosis blepharophimosis ptosis epicanthus inversus highly arched eyebrows and hypertelorism and vary in other symptoms such as asymmetry of the skull eyelid and anterior chamber anomalies cleft lip and palate umbilical anomalies and growth and cognitive development
mickaël vendetta real name mickael adon born october 3 1987 in le creusot france is a french internet phenomenon and entrepreneur whose notoriety followed upon the buzz he created on the internet through his personal blog
mickleson syndrome is a very rare congenital condition that is characterized by mental retardation and facial or skull anomalies it was first described by k n mickleson in 1983
soniccharge µtonic microtonic is a pattern based drum machine plug in featuring 100 synthetic drum sounds microtonic was created by software developer magnus lidström and is the first product launched under the sonic charge brand magnus is mostly recognized for his work with propellerhead software where he was the brain behind the synthesizer malström which was introduced in the 2 0 release of reason
micro syndrome also known as warbm and warburg – sjo – fledelius syndrome is a rare autosomal recessive genetic disorder characterized by microcephaly microcornea congenital cataract intellectual or developmental disability optic atrophy and hypogenitalism
in medicine hematology microangiopathic hemolytic anemia maha is a microangiopathic subgroup of hemolytic anemia loss of red blood cells through destruction caused by factors in the small blood vessels it is identified by the finding of anemia and schistocytes on microscopy of the blood film
microcephalic osteodysplastic primordial dwarfism type ii mopd ii is listed as a rare disease by the office of rare diseases ord of the national institutes of health nih this means that mopd or a subtype of mopd affects less than 200 000 people in the us population and a form of dwarfism associated with brain and skeletal abnormalities it was characterized in 1982 it is associated with pcnt
microcephaly is a medical condition in which the brain does not develop properly resulting in a smaller than normal head microcephaly may be present at birth or it may develop in the first few years of life often people with the disorder have an intellectual disability poor motor function poor speech abnormal facial features seizures and dwarfism the disorder may stem from a wide variety of conditions that cause abnormal growth of the brain or from syndromes associated with chromosomal abnormalities a homozygous mutation in one of the microcephalin genes causes primary microcephaly it serves as an important neurological indication or warning sign but no uniformity exists in its definition it is usually defined as a head circumference hc more than two standard deviations below the mean for age and sex some academics advocate defining it as head circumference more than three standard deviations below the mean for the age and sex there is no specific treatment that returns the head size to normal in general life expectancy for individuals with microcephaly is reduced and the prognosis for normal brain function is poor occasionally some will grow normally and develop normal intelligence
microcephaly lymphoedema chorioretinal dysplasia mlcrd is a genetic condition associated with small head microcephaly puffy feet lymphoedema eye problems chorio retinal dysplasia i e changes in the retina in 1992 feingold and bartoshesky described two unrelated children with microcephaly lymphoedema and chorioretinal dysplasia mim 152950 as a distinct entity since then there have been further reports of children with these three features angle et al 1994 fryns et al 1995 limwongse et al 1999 casteels et al 2001 children have also been seen with two of the above features microcephaly and lymphoedema microcephaly and chorioretinal dysplasia with or without intellectual disability the former microcephaly and lymphoedema has been described as an autosomal dominant mim 156590 or x linked trait while the latter microcephaly and chorioretinal dysplasia has been described as autosomal dominant autosomal recessive mim 251270 or mirhosseini holmes walton syndrome or x linked trait the distinct facial feature include upslanting palpebral fissures a broad nose with rounded tip long philtrum with a thin upper lip pointed chin and prominent ears vasudevan 2005
microcheilia is a congenital disorder where one s lips are unusually small
microchimerism abbreviated mc is the presence of a small number of cells that originate from another individual and are therefore genetically distinct from the cells of the host individual this phenomenon may be related to certain types of autoimmune diseases however the mechanisms responsible for this relationship are unclear
microcoria is a congenital disease in which the pupils of the subject are narrower than 2 mm in diameter microcoria is associated with juvenile onset glaucoma it is also associated with pierson syndrome chararacterized by microcoria and congenital nephrotic syndrome the defect is in the laminin beta 2 gene on chromosome 3 p 21 which encodes a protein essential to the glomerular basement membrane it is also part of the known manifestations of a born infant to a mother suffering from uncontrolled hyperglycemia other symptoms include transposition of great vessels respiratory distress secondary to surfactant defect sacral agensis jitteriness irritability and lethargy due to rebound fetal hypoglycemia congenital microcoria is an autosomal dominant trait however it can also occur sporadically
microcystic adnexal carcinoma also known as sclerosing sweat duct carcinoma is a cutaneous condition characterized by a slow growing plaque or nodule
microcystic lymphatic malformations are a cutaneous condition characterized by aggregations of ill defined abnormal microscopic lymphatic channels
microcytic anaemia is any of several types of anemia characterized by small red blood cells called microcytes the normal mean corpuscular volume abbreviated to mcv on full blood count results is 80 100 fl with smaller cells 80 fl described as microcytic and larger cells 100 fl as macrocytic the latter occur in macrocytic anemia the mcv is the average red blood cell size in microcytic anemia the red blood cells erythrocytes are usually also hypochromic meaning that the red blood cells appear paler than usual this is reflected by a lower than normal mean corpuscular hemoglobin concentration mchc a measure representing the amount of hemoglobin per unit volume of fluid inside the cell normally about 320 360 g l or 32 36 g dl typically therefore anemia of this category is described as microcytic hypochromic anaemia
microcytosis is a condition in which red blood cells are unusually small as measured by their mean corpuscular volume it is also known as microcythemia when associated with anemia it is known as microcytic anemia
microdeletion syndrome is a syndrome caused by a chromosomal deletion smaller than 5 million base pairs 5 mb spanning several genes that is too small to be detected by conventional cytogenetic methods or high resolution karyotyping 2 5 mb detection is done by fluorescence in situ hybridization fish larger chromosomal deletion syndromes are detectable using karyotyping techniques
microdontia is a condition in which one or more teeth appear smaller than normal in the generalized form all teeth are involved in the localized form only a few teeth are involved the most common teeth affected are the upper lateral incisors and third molars teeth affected by microdontia may also have abnormal shape and the abnormal size may affect the whole tooth or only a part of the tooth
microelectronics is a subfield of electronics as the name suggests microelectronics relates to the study and manufacture or microfabrication of very small electronic designs and components usually but not always this means micrometre scale or smaller these devices are typically made from semiconductor materials many components of normal electronic design are available in a microelectronic equivalent these include transistors capacitors inductors resistors diodes and naturally insulators and conductors can all be found in microelectronic devices unique wiring techniques such as wire bonding are also often used in microelectronics because of the unusually small size of the components leads and pads this technique requires specialized equipment and is expensive digital integrated circuits ics consist mostly of transistors analog circuits commonly contain resistors and capacitors as well inductors are used in some high frequency analog circuits but tend to occupy large chip area if used at low frequencies gyrators can replace them in many applications as techniques improve the scale of microelectronic components continues to decrease at smaller scales the relative impact of intrinsic circuit properties such as interconnections may become more significant these are called parasitic effects and the goal of the microelectronics design engineer is to find ways to compensate for or to minimize these effects while always delivering smaller faster and cheaper devices
microglandular hyperplasia mgh of the cervix is an epithelial endocervical mucosa benign abnormality lesion associated with gland proliferation it can terminate in mature squamous metaplasia and it is suspected reserve cells are involved in this process perhaps in the form of reserve cell hyperplasia with glandular differentiation
micrognathism also called micrognathia strawberry chin hypognathia or hypogthathism is a condition where the jaw is undersized it is also sometimes called mandibular hypoplasia it is common in infants but is usually self corrected during growth due to the jaws increasing in size it may be a cause of abnormal tooth alignment and in severe cases can hamper feeding it can also both in adults and children make intubation difficult either during anesthesia or in emergency situations
micrographia is an acquired disorder where there is abnormally small cramped handwriting or the progression to continually smaller handwriting it is commonly associated with neurodegenerative disorders of the basal ganglia such as in parkinson s disease but it has also been described in subcortical focal lesions o sullivan and schmitz describe it as an abnormally small handwriting that is difficult to read as seen in the photo to the right micrographia is also seen in patients with wilson s disease and metamorphopsia or with isolated focal lesions of the midbrain or basal ganglia
microscopic hematuria is a medical condition in which urine contains small amounts of blood blood quantity is too low to change the color of the urine otherwise it is known as gross hematuria while not dangerous in itself it maybe a symptom of kidney disease such as iga nephropathy which should be monitored by a doctor the american urological association aua recommends a definition of microscopic hematuria as three or more red blood cells per high power microscopic field in urinary sediment from two of three properly collected urinalysis specimens
microhydranencephaly mhac is a severe abnormality of brain development characterized by both microcephaly and hydranencephaly signs and symptoms may include severe microcephaly scalp rugae a series of ridges and profound developmental delay familial occurrence of the condition is very rare but it has been reported in a few families it has been suggested that mhac is possibly inherited in an autosomal recessive manner
in computer science a microkernel also known as μ kernel is the near minimum amount of software that can provide the mechanisms needed to implement an operating system os these mechanisms include low level address space management thread management and inter process communication ipc if the hardware provides multiple rings or cpu modes the microkernel may be the only software executing at the most privileged level which is generally referred to as supervisor or kernel mode traditional operating system functions such as device drivers protocol stacks and file systems are typically removed from the microkernel itself and are instead run in user space in terms of the source code size as a general rule microkernels tend to be smaller than monolithic kernels usually sizing at under 10 000 lines of code the minix 3 microkernel for example has fewer than 6 000 lines of code
micromastia also called hypomastia breast aplasia breast hypoplasia or mammary hypoplasia is a medical term describing the postpubertal underdevelopment of a woman s breast tissue just as it is impossible to define normal breast size there is no objective definition of micromastia breast development is commonly asymmetric and one or both breasts may be small this condition may be a congenital defect associated with underlying abnormalities of the pectoral muscle as in poland s syndrome related to trauma typically surgery or radiotherapy or it may be a more subjective aesthetic description self perceived micromastia involves a discrepancy between a person s body image and her internalized images of appropriate or desirable breast size and shape societal ideals over breast size vary over time but there exist many conceived ideas involving breasts and sexual attractiveness and identity across different cultures
micronutrient deficiency or dietary deficiency is a lack of one or more of the micronutrients required for plant or animal health in humans and other animals they include both vitamin deficiencies and mineral deficiencies whereas in plants the term refers to deficiencies of essential trace minerals
microorchidism is a genetic disorder found in males characterized by abnormally small testes the condition is associated with and often secondary to a number of other genetic disorders including klinefelter s syndrome and prader willi syndrome as well as other multiple malformation disorders the degree of abnormality or otherwise of the testes can be determined by the use of an orchidometer in addition microorchidism may also occur as a result of shrinkage or atrophy of the testis due to infections like mumps
micropenis is an unusually small penis a common criterion is a dorsal measured on top erect penile length of at least 2 5 standard deviations smaller than the mean human penis size or smaller than about 7 cm 2 3 ⁄ 4 in for an adult when compared to an average erection of 12 5 cm 5 in the condition is usually recognized shortly after birth the term is most often used medically when the rest of the penis scrotum and perineum are without ambiguity such as hypospadias micropenis occurs in about 0 6 of males
a microphone gaffe sometimes referred to as an open microphone in aviation a stuck mic or a hot mic is an apparent error whereby a microphone is switched on in proximity of a subject who is unaware that their remarks are being broadcast the error allows unintended listeners to hear parts of private conversations errors usually involve live broadcasting in radio or television and sometimes material is recorded and played back via media outlets such events can cause embarrassment for the person or organization involved sometimes resulting in serious confrontations and employment termination
microphonism is the effect of unwanted modulation that is produced mechanically in an electronic circuit it often may be alleviated by embedding the circuit in paraffin or silicone or using some type of elastic suspension rubber or caoutchouc are widely used when an oscillator is subjected to a mechanical action such as vibration or shock its oscillation frequency changes and the result is a signal at the base oscillator frequency frequency modulated by the mechanical signal the usual test for microphonism in electron tubes is to tap the tube with a finger light mallet or small rubber ball while working as amplifier or oscillator
microphthalmia greek μικρός micros small ὀφθαλμός ophthalmos eye also referred as microphthalmos is a developmental disorder of the eye in which one unilateral microphthalmia or both bilateral microphthalmia eyes are abnormally small and have anatomic malformations it is different from nanophthalmos in which the eye is small in size but has no anatomical alterations
microphthalmia – dermal aplasia – sclerocornea syndrome also known as midas syndrome is a condition characterized by linear skin lesions mls is a rare x linked dominant male lethal disease characterized by unilateral or bilateral microphthalmia and linear skin defects in affected females and in utero lethality for affected males it can be associated with hccs but mutations in the mccs gene cause microphthalmia with linear skin defects syndrome
a micropipe also called a micropore microtube capillary defect or pinhole defect is a crystallographic defect in a single crystal substrate today this is of great interest to makers of silicon carbide sic substrates which are used in a variety of industries such as power semiconductor devices for vehicles and high frequency communication devices however during the production of these materials the crystal undergoes internal and external stresses causing growth of defects or dislocations within the atomic lattice a screw dislocation is a common dislocation that transforms successive atomic planes within a crystal lattice into the shape of a helix once a screw dislocation propagates through the bulk of a sample during the wafer growth process a micropipe is formed the presence of a high density of micropipes within a wafer will result in a loss of yield in the device manufacturing process micropipes and screw dislocations in epitaxial layers are normally derived from the substrates on which the epitaxy is performed micropipes are considered to be empty core screw dislocations with large strain energy i e they have large burgers vector they follow the growth direction c axis in silicon carbide boules and substrates propagating into the deposited epitaxial layers factors which influence formation of micropipes and other defects are such growth parameters as temperature supersaturation vapor phase stoichiometry impurities and the polarity of the seed crystal surface many laboratories in universities and companies are striving to perfect the micropipe free substrate one of the pioneers of the commercialization of sic materials and devices is cree inc which in may 2007 announced that it had achieved 100 mm 4 inch zero micropipe n type sic substrates it is therefore possible to eliminate these defects in large area wafers as well as smaller fragments and should open up the commercialization of this area of microelectronic devices
microplasticity is a local phenomenon in metals it occurs for stress values where the metal is globally in the elastic domain while some local areas are in the plastic domain
micropolygyria also known as polymicrogyria polygyria or microgyria is a neuronal migration disorder a developmental anomaly of the brain characterized by development of numerous small convolutions microgyri causing mental retardation and or other neurological disorders it is present in a number of specific neurological diseases notably multiple sclerosis and fukuyama congenital muscular dystrophy a specific disease cause by mutation in the fukutin gene fktn
micropsia is a condition affecting human visual perception in which objects are perceived to be smaller than they actually are micropsia can be caused by optical factors such as wearing glasses by distortion of images in the eye such as optically via swelling of the cornea or from changes in the shape of the retina such as from retinal edema macular degeneration or central serous retinopathy by changes in the brain such as from traumatic brain injury epilepsy migraines prescription drugs and illicit drugs and from psychological factors dissociative phenomena are linked with micropsia which may be the result of brain lateralization disturbance micropsia is also commonly reported when the eyes are fixating at convergence or focussing at accommodation a distance closer than that of the object in accord with emmert s law specific types of micropsia include hemimicropsia a form of micropsia that is localized to one half of the visual field and can be caused by brain lesions in one of the cerebral hemispheres related visual distortion conditions include macropsia a less common condition with the reverse effect and alice in wonderland syndrome a condition that has symptoms that can include both micropsia and macropsia
microsatellite instability msi is the condition of genetic hypermutability that results from impaired dna mismatch repair mmr the presence of msi represents phenotypic evidence that mmr is not functioning normally mmr corrects errors that spontaneously occur during dna replication such as single base mismatches or short insertions and deletions the proteins involved in mmr correct polymerase errors by forming a complex that binds to the mismatched section of dna excises the error and inserts the correct sequence in its place cells with abnormally functioning mmr are unable to correct errors that occur during dna replication and consequently accumulate errors this causes the creation of novel microsatellite fragments polymerase chain reaction based assays can reveal these novel microsatellites and provide evidence for the presence of msi microsatellites are repeated sequences of dna these sequences can be made of repeating units of one to six base pairs in length although the length of these microsatellites is highly variable from person to person and contributes to the individual dna fingerprint each individual has microsatellites of a set length the most common microsatellite in humans is a dinucleotide repeat of the nucleotides c and a which occurs tens of thousands of times across the genome microsatellites are also known as simple sequence repeats ssrs
microscopic colitis refers to two related medical conditions which cause diarrhea collagenous colitis and lymphocytic colitis both conditions are characterized by the presence of chronic non bloodly watery diarrhea normal appearances on colonoscopy and characteristic histopathology findings of inflammatory cells
microscopic polyangiitis is an ill defined autoimmune disease characterized by a systemic pauci immune necrotizing small vessel vasculitis without clinical or pathological evidence of necrotizing granulomatous inflammation
microspherophakia is a rare congenital autosomal recessive condition where the lens of the eye is smaller than normal and spherically shaped this condition may be associated with a number of disorders including peter s anomaly marfan syndrome and weill – marchesani syndrome the spherical shape is caused by an underdeveloped zonule of zinn which doesn t exert enough force on the lens to make it form the usual oval shape it is a result of a homozygous mutation to the ltbp 2 gene
microsporidiosis is an opportunistic intestinal infection that causes diarrhea and wasting in immunocompromised individuals hiv for example it results from different species of microsporidia a group of microbial unicellular fungi in hiv infected individuals microsporidiosis generally occurs when cd 4 t cell counts fall below 150
a microstate continuum is the fluctuation spectrum of a thermodynamic system in the classical limit of high temperatures classical here is to be understood in opposition to quantum statistical mechanics
microstomia micro a combining form meaning small stomia a combining form meaning mouth abnormally small mouth is a clinical feature of many craniofacial syndromes including freeman sheldon syndrome and sheldon hall syndromes or distal arthrogryposis multiplex congenita it may present with whistling face feature as well as in freeman sheldon syndrome in this syndrome it impairs alimentation and may require repeated oral surgeries called commissurotomy to improve function it can also be a feature of systemic scleroderma
microtia is a congenital deformity where the pinna external ear is underdeveloped a completely undeveloped pinna is referred to as anotia because microtia and anotia have the same origin it can be referred to as microtia anotia microtia can be unilateral one side only or bilateral affecting both sides microtia occurs in 1 out of about 8 000 – 10 000 births in unilateral microtia the right ear is most commonly affected it may occur as a complication of taking accutane isotretinoin during pregnancy
microvascular occlusion refers to conditions that can present with retiform purpura it has been suggested that phenylephrine may be a cause
microvenular hemangioma also known as microcapillary hemangioma is an acquired benign vascular neoplasm that presents as an asymptomatic slowly growing 0 5 to 2 0 cm reddish lesion on the forearms or other sites of young to middle aged adults
microvillus inclusion disease also known as davidson s disease congenital microvillus atrophy and less specifically microvillus atrophy note microvillus is often misspelled as microvillous is a rare genetic disorder of the small intestine that is inherited in an autosomal recessive pattern
microwave burns are burn injuries caused by thermal effects of microwave radiation absorbed in a living organism in comparison with radiation burns caused by ionizing radiation where the dominant mechanism of tissue damage is internal cell damage caused by free radicals the primary damage mechanism of microwave radiation is thermal by dielectric heating microwave damage can manifest with a delay pain and or signs of skin damage can show some time after microwave exposure
middle east respiratory syndrome mers also known as camel flu is a viral respiratory infection caused by the mers coronavirus mers cov symptoms may range from mild to severe they include fever cough diarrhea and shortness of breath disease is typically more severe in those with other health problems mers cov is a betacoronavirus derived from bats camels have been shown to have antibodies to mers cov but the exact source of infection in camels has not been identified camels are believed to be involved in its spread to humans but it is unclear how spread between humans typically requires close contact with an infected person its spread is uncommon outside of hospitals thus its risk to the global population is currently deemed to be fairly low as of 2015 there is no specific vaccine or treatment for the disease however a number of antiviral medications are currently being studied the world health organization recommends that those who come in contact with camels wash their hands frequently and do not touch sick camels they also recommend that camel products be appropriately cooked among those who are infected treatments that help with the symptoms may be given just over 1000 cases of the disease have been reported as of may 2015 about 40 of those who become infected die from the disease the first identified case occurred in 2012 in saudi arabia and most cases have occurred in the arabian peninsula a strain of mers cov known as hcov emc 2012 found in the first infected person in london in 2012 was found to have a 100 match to egyptian tomb bats a large outbreak occurred in the republic of korea in 2015
the term middle miocene disruption alternatively the middle miocene extinction or middle miocene extinction peak refers to a wave of extinctions of terrestrial and aquatic life forms that occurred around the middle of the miocene roughly 14 8 to 14 5 million years ago during the langhian stage of the miocene madelaine bohme observed the occurrence of varanidae chameleon cordylidae tomistominae alligatoridae and giant turtles which indicate survival through the miocene climatic optimum 18 to 16 ma in central europe 45 42 ° n palaeolatitude a major and permanent cooling step occurred between 14 8 and 14 1 ma associated with increased production of cold antarctic deep waters and a major growth of the east antarcticice sheet two crocodilians of the genera gavialosuchus and diplocynodon were noted to have been extant in these northern latitudes prior to the permanent cooling step then became extinct 13 5 to 14 ma a middle miocene delta 18 o increase that is a relative increase in the heavier isotope of oxygen has been noted in the pacific the southern ocean and the south atlantic
upper back pain also called middle back pain or thoracic back pain is back pain that is felt in the region of the thoracic vertebrae which are between the bottom of the neck and top of the lumbar spine it has a number of potential causes ranging from muscle strain to collapse of a vertebra or rare serious diseases the upper spine is very strong and stable to support the weight of the upper body as well as to anchor the rib cage which provides a cavity to allow the heart and lungs to function and protect them in most cases the pain is likely to be self limiting in that case no diagnostic tests are required and simple pain relief is sufficient more severe and prolonged cases may require more specific pain management strategies and occasionally investigations for underlying medical diseases all forms of back pain can lead to loss of earnings reduced quality of life and disability
middle cerebral artery syndrome is a condition whereby the blood supply from the middle cerebral artery mca is restricted leading to a reduction of the function of the portions of the brain supplied by that vessel the lateral aspects of frontal temporal and parietal lobes the corona radiata globus pallidus caudate and putamen the mca is the most common site for the occurrence of ischemic stroke depending upon the location and severity of the occlusion signs and symptoms may vary within the population affected with mca syndrome more distal blockages tend to produce milder deficits due to more extensive branching of the artery and less ischemic response in contrast the most proximal occlusions result in widespread effects that can lead to significant cerebral edema increased intracranial pressure loss of consciousness and could even be fatal in such occasions mannitol osmotic diuretic or hypertonic saline are given to draw fluid out of the oedematus cerebrum to minimise secondary injury hypertonic saline is better than mannitol as mannitol being a diuretic will decrease the mean arterial pressure and since cerebral perfusion is mean arterial pressure minus intracranial pressure mannitol will also cause a decrease in cerebral perfusion contralateral hemiparesis and hemisensory loss of the face upper and lower extremities is the most common presentation of mca syndrome lower extremity function is more spared than that of the faciobrachial region the majority of the primary motor and somatosensory cortices are supplied by the mca and the cortical homunculus can therefore be used to localize the defects more precisely middle cerebral artery lesions mostly affect the dominant hemisphere i e the left cerebral hemisphere
at the core of the movement were the members of the lunar society of birmingham who included erasmus darwin matthew boulton james watt joseph priestley josiah wedgwood james keir and thomas day other notable figures included the author anna seward the painter joseph wright of derby the american colonist botanist and poet susanna wright the lexicographer samuel johnson the typographer john baskerville the poet and landscape gardener william shenstone and the architects james wyatt and samuel wyatt although the midlands enlightenment has attracted less study as an intellectual movement than the european enlightenment of thinkers such as jean jacques rousseau and voltaire or the scottish enlightenment of david hume and adam smith it dominated the experience of the enlightenment within england and its leading thinkers had international influence in particular the midlands enlightenment formed a pivotal link between the earlier scientific revolution and the later industrial revolution facilitating the exchange of ideas between experimental science polite culture and practical technology that enabled the technological preconditions for rapid economic growth to be attained its participants such as boulton susanna wright watt and keir were fully integrated into the exchange of scientific and philosophical ideas among the intellectual elites of europe the british american colonies and the new united states but were simultaneously engaged in solving the practical problems of technology economics and manufacture they thus formed a natural bridge across the science technology divide where the abstract knowledge of chemistry and newtonian mechanics could become the useful knowledge of technological development the results of which could in turn feed back into the wider scientific knowledge base creating a chain reaction of innovation susanna wright was involved in similar thinking in the american colonies and early united states particularly in the mid atlantic north of the mason – dixon line she was born in 1697 in warrington in lancashire and moved to colonial pennsylvania in her late teens in 1718 following her parents four years earlier after being educated in the midlands the thinkers of the midlands enlightenment did not limit themselves to practical matters of utilitarian value however and their influence was not confined to their significance in the development of modern industrial society the ideas of the midlands enlightenment were to be highly influential in the birth of british romanticism with the poets percy shelley william wordsworth samuel taylor coleridge and william blake all having intellectual connections to its leading thinkers and midlands enlightenment thought was also influential in the spheres of education evolutionary biology botany medicine the midlands enlightenment was connected to earlier midlands radical religious reform of establishment of catholic church and holy roman empire ideology including the founding of the society of friends in lancashire by followers of margaret fell and george fox and midlands nonviolent political radicalism that led to the documentation of the english bill of rights in 1689
midline cervical clefts are a rare congenital anomaly resulting from incomplete fusion during embryogenesis of the first and second branchial arches in the ventral midline of the neck the condition presents as a midline cutaneous defect of the anterior neck with a skin projection or sinus or as a subcutaneous erythematous fibrous cord surgical excision is the preferred treatment
midline nevus flammeus also known as angel s kiss is a vascular birthmark which may be found on the glabellar region or on one upper eyelid and presents in approximately 15 of newborns
midnight lightning is a bouldering problem on the columbia boulder in camp 4 of yosemite national park it has been described as the world s most famous bouldering problem the first ascent was by ron kauk in 1978 the first female ascent was by lynn hill in 1998 sam moses writing in sports illustrated said the most difficult move on midnight lightning is a spider monkey swing 15 feet 4 6 metres off the ground the climber must suspend himself by the fingertips of his left hand swing around a ledge of rock and propel himself far enough up about four feet to grab a precarious fingertip hold with his right hand to do that he has to create momentum from stillness the problem had been easily identified by a chalk lightning bolt drawn by john bachar in 1978 while attempting the problem with john yablonski and ron kauk in may 2013 the iconic chalk lightning bolt was scrubbed off the face of the boulder the bolt was re drawn in the same location a few days later the climb is rated at v 8 on the vermin scale of difficulty
the midnight sun is a natural phenomenon that occurs in the summer months in places north of the arctic circle or south of the antarctic circle when the sun remains visible at the local midnight around the summer solstice approximately 21 june in the northern hemisphere and 22 december in the southern hemisphere the sun is visible for the full 24 hours given fair weather the number of days per year with potential midnight sun increases the farther towards either pole one goes although approximately defined by the polar circles in practice the midnight sun can be seen as much as 55 miles 90 km outside the polar circle as described below and the exact latitudes of the farthest reaches of midnight sun depend on topography and vary slightly year to year there are no permanent economically autonomous human settlements south of the antarctic circle only research stations so the countries and territories whose populations experience the midnight sun are limited to those crossed by the arctic circle canada yukon northwest territories and nunavut greenland iceland finland norway russia sweden and the united states alaska a quarter of finland s territory lies north of the arctic circle and at the country s northernmost point the sun does not set at all for 60 days during summer in svalbard norway the northernmost inhabited region of europe there is no sunset from approximately 19 april to 23 august the extreme sites are the poles where the sun can be continuously visible for half the year the opposite phenomenon polar night occurs in winter when the sun stays below the horizon throughout the day since the axial tilt of the earth is considerable approximately 23 degrees 27 minutes the sun does not set at high latitudes in local summer the duration of sunlight increases from one day during the summer solstice at the polar circle to several weeks only 100 km closer to the pole to six months at the poles at extreme latitudes the midnight sun is usually referred to as polar day at the poles themselves the sun rises and sets only once each year during the six months that the sun is above the horizon it spends the days continuously moving in circles around the observer gradually spiralling higher and reaching its highest circuit of the sky at the summer solstice because of atmospheric refraction and also because the sun is a disk rather than a point the midnight sun may be experienced at latitudes slightly below the polar circle though not exceeding one degree depending on local conditions for example iceland is known for its midnight sun even though most of it grímsey is the exception is slightly south of the arctic circle for the same reasons the period of sunlight at the poles is slightly longer than six months even the northern extremities of scotland and places at similar latitudes such as st petersburg experience twilight in the northern sky at around the summer solstice observers at heights appreciably above sea level can experience extended periods of midnight sun as a result of the dip of the horizon viewed from altitude
migraine is a primary headache disorder characterized by recurrent headaches that are moderate to severe typically the headaches affect one half of the head are pulsating in nature and last from two to 72 hours associated symptoms may include nausea vomiting and sensitivity to light sound or smell the pain is generally made worse by physical activity up to one third of people have an aura typically a short period of visual disturbance which signals that the headache will soon occur occasionally an aura can occur with little or no headache following it migraines are believed to be due to a mixture of environmental and genetic factors about two thirds of cases run in families changing hormone levels may also play a role as migraines affect slightly more boys than girls before puberty and two to three times more women than men the risk of migraines usually decreases during pregnancy the underlying mechanisms are not fully known it is however believed to involve the nerves and blood vessels of the brain initial recommended treatment is with simple pain medication such as ibuprofen and paracetamol acetaminophen for the headache medication for the nausea and the avoidance of triggers specific medications such as triptans or ergotamines may be used in those for whom simple pain medications are not effective caffeine may be added to the above a number of medications are useful to prevent attacks including metoprolol valproate and topiramate globally approximately 15 of people are affected by migraines it most often starts at puberty and is worst during middle age in some women they become less common following menopause an early description consistent with migraines is contained in the ebers papyrus written around 1500 bce in ancient egypt the word migraine is from the greek ἡμικρανία hemikrania pain on one side of the head from ἡμι hemi half and κρανίον kranion skull
vestibular migraine vm is vertigo associated with a migraine either as a symptom of migraine or as a related but neurological disorder when referred to as a disease unto itself it is also termed migraine associated vertigo mav migrainous vertigo or migraine related vestibulopathy a 2010 report from the university of british columbia published in the journal headache said that it is emerging as a popular diagnosis for patients with recurrent vertigo even though some authors believe that migraine associated vertigo is neither clinically nor biologically plausible as a migraine variant epidemiological studies leave no doubt that there is a strong link between vertigo and migraine
migralepsy is a rare condition in which a migraine is followed within an hour period by an epileptic seizure because of the similarities in signs symptoms and treatments of both conditions such as the neurological basis the psychological issues and the autonomic distress that is created from them they individually increase the likelihood of causing the other however also because of the sameness they are often misdiagnosed for each other as migralepsy rarely occurs
migration museums cover human migration in the past present and future the current trend in the development of migration museums named differently worldwide is an interesting phenomenon as it may contribute to the creation of a new and multiple identity at an individual and collective level the united states with ellis island australia canada and more recently several european countries — e g france germany italy the netherlands portugal spain switzerland and the united kingdom — have been creating such venues to facilitate transmission between generations as well as encounters between migrants and the host populations by telling their personal story while these initiatives also serve the duty to remember they seem to have three main objectives acknowledge integrate and build awareness acknowledge the contributions made by migrants to their host societies the diversity and wealth of the origin cultures and the right to a dual belonging include and integrate foster the sense of belonging enable the communities to feel as an integral part of the nation find common ground and contribute to a national identity build awareness and educate on the events that induced individuals — and refugees in particular — to leave their land thus developing empathy among the host population more generally deconstruct stereotypes on immigration given the international scene and the latest events from the van gogh affair in the netherlands in 2004 to the so called ‘ crise des banlieues ’ in france in 2005 there is an urgent need to give the migrant generations the youth as well as their parents a voice in order to foster inclusion integration and the right to difference listening to individual stories may help to deconstruct stereotypes memory history and narration may also allow to take a step back and to consider the complete picture migration museums also face common challenges in that they intend to be not only a venue for conservation and exhibition but also and above all a lively meeting place the challenge is not so much to bring in the intellectuals academics researchers historians traditional visitors of museums the converted but to attract the general public those with preconceived ideas on immigration and the migrants themselves in addition to the following list there are many local heritage initiatives and smaller museums which have increasingly focused on migration as a part of the narrative they portray
migratory aptitude is the relative ability of a migrating group to migrate in a rearrangement reaction this can be affected by the leaving group whichever gives a more stable carbocation depends upon the electron density of the migrating group i e hydride phenyl tert alkyl sec alkyl primary alkyl methyl the migratory groups follow the order of increasing stability of carbocation instead of carbanion
a migratory insertion is a type of reaction in organometallic chemistry wherein two ligands on a metal complex combine it is a subset of reactions that very closely resembles the insertion reactions and both are differentiated by the mechanism that leads to the resulting stereochemistry of the products however often the two are used interchangeably because the mechanism is sometimes unknown therefore migratory insertion reactions or insertion reactions for short are defined not by the mechanism but by the overall regiochemistry wherein one chemical entity interposes itself into an existing bond of typically a second chemical entity e g a b – c → b – a – c
the milas hydroxylation is an organic reaction converting an alkene to a vicinal diol and was developed by nicholas a milas in the 1930 s the cis diol is formed by reaction of alkenes with hydrogen peroxide and either ultraviolet light or a catalytic osmium tetroxide vanadium oxide or chromium oxide the reaction has been superseded in synthetic chemistry by the upjohn dihydroxylation and later by the sharpless asymmetric dihydroxylation
mild androgen insensitivity syndrome mais is a condition that results in a mild impairment of the cell s ability to respond to androgens the degree of impairment is sufficient to impair spermatogenesis and or the development of secondary sexual characteristics at puberty in males but does not affect genital differentiation or development female genital and sexual development is not significantly affected by the insensitivity to androgens as such mais is only diagnosed in males the clinical phenotype associated with mais is a normal male habitus with mild spermatogenic defect and or reduced secondary terminal hair mais is one of three types of androgen insensitivity syndrome which is divided into three categories that are differentiated by the degree of genital masculinization complete androgen insensitivity syndrome cais is indicated when the external genitalia is that of a normal female mild androgen insensitivity syndrome mais is indicated when the external genitalia is that of a normal male and partial androgen insensitivity syndrome pais is indicated when the external genitalia is partially but not fully masculinized androgen insensitivity syndrome is the largest single entity that leads to 46 xy undermasculinization
mild cognitive impairment mci also known as incipient dementia or isolated memory impairment is a brain function syndrome involving the onset and evolution of cognitive impairments beyond those expected based on the age and education of the individual but which are not significant enough to interfere with their daily activities it may occur as a transitional stage between normal aging and dementia although mci can present with a variety of symptoms when memory loss is the predominant symptom it is termed amnestic mci and is frequently seen as a prodromal stage of alzheimer s disease studies suggest that these individuals tend to progress to probable alzheimer ’ s disease at a rate of approximately 10 to 15 per year additionally when individuals have impairments in domains other than memory it is classified as nonamnestic single or multiple domain mci and these individuals are believed to be more likely to convert to other dementias e g dementia with lewy bodies however some instances of mci may simply remain stable over time or even remit causation of the syndrome in and of itself remains unknown as therefore do prevention and treatment
the miles canyon basalts represent a package of rocks that include various exposures of basaltic lava flows and cones that erupted and flowed across an ancient pre glacial landscape in south central yukon the volcanic rocks are best exposed and most easily accessible at the miles canyon location where the yukon river cuts through a succession of flows south of whitehorse in the spring good exposures can also be seen immediately downstream from the yukon river hydro dam in whitehorse which was built to extract energy from the cataracts that were the white horse rapids these rapids and the miles canyon provided a significant challenge to gold seekers heading to the klondike gold rush and also established the upstream terminus for paddle wheel river boats this the miles canyon basalts are the reason for the establishment of the townsite of closeleigh eventually the city of whitehorse the lava flows and cinder cones in the alligator lake volcanic complex southwest of whitehorse are the greatest accumulation of these rocks the miles canyon basalts were thought to be pleistocene age however geological investigations supported by geochronological analyses indicate that these rocks are much older the type miles canyon flows along the yukon river are 8 4 million years old miocene and the alligator lake flows are 3 2 million years old pliocene the alligator lake cones may be younger but have been affected by glaciation so are not entirely post glacial in age
milia like calcinosis is a cutaneous condition characterized by small milia like lesions that develop on the dorsal surface of the hands and the face
milia en plaque is a cutaneous condition characterized by multiple milia within an erythematous edematous plaque
miliaria ˌmɪl iˈɛər i ə also called sweat rash heat rash or prickly heat is a skin disease marked by small and itchy rashes miliaria is a common ailment in hot and humid conditions such as in the tropics and during the summer season although it affects people of all ages it is especially common in children and infants due to their underdeveloped sweat glands
miliary tuberculosis is a form of tuberculosis that is characterized by a wide dissemination into the human body and by the tiny size of the lesions 1 – 5 mm its name comes from a distinctive pattern seen on a chest radiograph of many tiny spots distributed throughout the lung fields with the appearance similar to millet seeds — thus the term miliary tuberculosis miliary tb may infect any number of organs including the lungs liver and spleen miliary tuberculosis is present in about 2 of all reported cases of tuberculosis and accounts for up to 20 of all extra pulmonary tuberculosis cases
a military budget or military expenditure also known as a defense budget is the amount of financial resources dedicated by a nation to raising and maintaining an armed forces or other methods essential for defense purposes military budgets often reflect how strongly an entity perceives the likelihood of threats against it or the amount of aggression it wishes to employ it also gives an idea of how much financing should be provided for the upcoming year the size of a budget also reflects the entity s ability to fund military activities factors include the size of that entity s economy other financial demands on that entity and the willingness of that entity s government or people to fund such military activity generally excluded from military expenditures is spending on internal law enforcement and disabled veteran rehabilitation the effects of military expenditure on a nation s economy and society and what determines military expenditure are notable issues in political science and economics there are controversial findings and theories regarding these topics generally some suggest military expenditure is a boost to local economies still others maintain military expenditure is a drag on development every year in april is the global day of action on military spending gdams which aims to gather people and create a global movement that persuades governments to reallocate their military spending to essential human needs such as food education health care social services and environmental concerns among the countries maintaining some of the world s largest military budgets china france germany japan russia the united kingdom and the united states are frequently recognized to be great powers according to the stockholm international peace research institute in 2014 total world military expenditure amounted to 1 8 trillion us
military globalization was defined by david held as “ the process which embodies the growing extensity and intensity of military relations among the political units of the world system … understood as such it reflects both the expanding network of worldwide military ties and relations as well as the impact of key military technological innovations from steamships to satellites which over time have reconstituted the world into a single geostrategic space military globalization implies firmer integration of armed forces around the world into the global military system for robert keohane and joseph nye military globalization entails “ long distance networks of interdependence in which force and the threat or promise of force are employed ” held divides the military globalization into three distinct phenomena 1 the globalization of the war system this refers to the “ geopolitical order great power rivalry conflict and security relations ” 2 the global system of arms production and transfers reflected in the global arms dynamics 3 the geo governance of violence “ embracing the formal and informal international regulation of the acquisition deployment and use of military force ” all three processes above “ are connected to technological development which made them possible in the first place the result is increasing global interdependence and complexity the process of military globalization starts with the age of discovery when the european colonial empires began military operations on the global scale their imperial rivalry led to the first world war which was the first global conflict in world history keohane dates military globalization at least from the time of alexander the great ’ s conquests
a milium plural milia also called a milk spot or an oil seed is a clog of the eccrine duct the true sweat gland it is a keratin filled cyst that can appear just under the epidermis or on the roof of the mouth milia are commonly associated with newborn babies but can appear on people of all ages they are usually found around the nose and eyes and sometimes on the genitalia often mistaken by those affected as warts or other sexually transmitted diseases milia can also be confused with stubborn whiteheads in children milia often disappear within two to four weeks for adults they can be removed by a physician a dermatologist will have specialist knowledge in this area
in medicine milk alkali syndrome is characterized by high blood calcium caused by taking in too much calcium and absorbable alkali common sources of calcium and alkali are dietary supplements taken to prevent osteoporosis and antacids if untreated milk alkali syndrome may lead to kidney failure or death it was most common in the early 20 th century but since the 1990 s there has been an increase in the number of cases reported linked to the increased use of calcium supplements to address or prevent osteoporosis
a milk allergy is a food allergy an adverse immune reaction to one or more of the constituents of milk from any animal most commonly alpha s 1 casein a protein in cow s milk this milk induced allergic reaction can involve anaphylaxis a potentially life threatening condition
milk fever postparturient hypocalcemia or parturient paresis is a disease primarily in dairy cattle but also seen in beef cattle characterized by reduced blood calcium levels see hypocalcemia it occurs following parturition at onset of lactation when demand for calcium for colostrum production exceeds the body ’ s ability to mobilize calcium “ fever ” is a misnomer as body temperature during the disease is generally not elevated milk fever is more commonly seen in older animals which have reduced ability to mobilize calcium from bone and in certain breeds such as channel island breeds
milk sickness also known as tremetol vomiting or in animals as trembles is a kind of poisoning characterized by trembling vomiting and severe intestinal pain that affects individuals who ingest milk other dairy products or meat from a cow that has fed on white snakeroot plant which contains the poison tremetol although very rare today milk sickness claimed thousands of lives among european american migrants to the midwest in the early 19 th century in the united states especially in frontier areas along the ohio river valley and its tributaries where white snakeroot was prevalent new settlers were unfamiliar with the plant and its properties a notable victim was nancy hanks lincoln the mother of abraham lincoln who died in 1818 nursing calves and lambs may have died from their mothers milk contaminated with snakeroot although the adult cows and sheep showed no signs of poisoning cattle horses and sheep are the animals most often poisoned anna pierce hobbs bixby called dr anna on the frontier is credited today by the american medical community with having identified white snakeroot as the cause of the illness told about the plant s properties by an elderly shawnee woman she befriended bixby did testing to observe and document evidence she wrote up her findings to share the discovery in the medical world the shawnee woman s name has been lost to history
milker s nodules or milkmaid blisters are a cutaneous condition that is most commonly transmitted from the udders of infected cows milker s nodule is caused by paravaccinia virus disease in humans is nearly identical to orf
milky seas or mareel is a condition on the ocean where large areas of seawater up to 6 000 sq mi or 16 000 km 2 appear to glow brilliantly enough at night to be seen by satellites orbiting earth modern science only tentatively attributes this effect to bioluminescent bacteria or dinoflagellates causing the ocean to uniformly glow an eerie blue at night however there is no modern research to prove that bioluminescent bacteria are capable of illuminating the ocean from horizon to horizon and for days at a time as described in mariner s tales for centuries notably appearing in chapter 23 of jules verne s twenty thousand leagues under the sea and in fact the effect has not been rigorously documented nor thoroughly explained even in modern times
millard – gubler syndrome is a lesion of the pons it is also called ventral pontine syndrome
the millennium prize problems are seven problems in mathematics that were stated by the clay mathematics institute in 2000 the problems are birch and swinnerton dyer conjecture hodge conjecture navier – stokes existence and smoothness p versus np problem poincaré conjecture riemann hypothesis and yang – mills existence and mass gap a correct solution to any of the problems results in a us 1 million prize being awarded by the institute to the discoverers at present the only millennium prize problem to have been solved is the poincaré conjecture which was solved by the russian mathematician grigori perelman in 2003
miller syndrome is a genetic condition also known as the genee wiedemann syndrome wildervanck smith syndrome or postaxial acrofacial dystosis the incidence of this condition is not known but it is considered extremely rare it is due to a mutation in the dhodh gene nothing is known of its pathogenesis
millerandage or shot berries hens and chicks and pumpkins and peas is a potential viticultural hazard problem in which grape bunches contain berries that differ greatly in size and most importantly maturity its most common cause is cold rainy or otherwise bad weather during the flowering stage of the vines though other factors such as boron deficiency or fanleaf degeneration may also play a role while millerandage will always cause a drop in yield its potential impact on wine quality will vary particularly by grape variety for some varieties that are prone to uneven ripeness within a cluster such as sangiovese zinfandel and gewürztraminer the development of millerandage may be unfavorable due to green flavors from the potentially unripe grapes hidden within the cluster for other varieties such as pinot noir or the mendoza clone of chardonnay wine quality could potentially be improved due to the reduced overall berry size and higher skin to juice ratio
miller – dieker syndrome abbreviated mds miller – dieker lissencephaly syndrome mdls and chromosome 17 p 13 3 deletion syndrome is a micro deletion syndrome characterized by congenital malformations a physical defect detectable in an infant at birth which can involve many different parts of the body including the brain hearts lungs liver bones or intestinal tract in this case it is usually mainly the brain being affected the congenital malformation can be genetic random and of unknown origin the malformation is in fact characterized by lissencephaly smooth brain mds is a contiguous gene syndrome as well which is a disorder due to the deletion of multiple gene loci that are adjacent to one another the disorder arises from the deletion of part of the small arm of chromosome 17 p which includes both the lis 1 and 14 3 3 epsilon genes leading to partial monosomy there may be unbalanced translocations i e 17 q 17 p or 12 q 17 p or the presence of a ring chromosome 17 this syndrome should not be confused with miller syndrome an unrelated rare genetic disorder or miller fisher syndrome a form of guillain – barré syndrome
millipede burns are a cutaneous condition caused by some millipedes that secrete a toxic liquid that causes a brownish pigmentation or burn when it comes into contact with the skin some millipedes produce quinones in their defensive secretions which have been reported to cause brown staining of the skin
milroy s disease is a familial disease characterized by lymphedema commonly in the legs caused by congenital abnormalities in the lymphatic system disruption of the normal drainage of lymph leads to fluid accumulation and hypertrophy of soft tissues it is also known as milroy disease nonne milroy meige syndrome and hereditary lymphedema it was named by sir william osler for william milroy an american physician who described a case in 1892 though it was first described by rudolf virchow in 1863
milwaukee shoulder syndrome apatite associated destructive arthritis is a rheumatological condition similar to calcium pyrophosphate dihydrate deposition disease cppd it is associated with periarticular or intraarticular deposition of hydroxyapatite crystals crystal deposition in the joint causes the release of collagenases serine proteases elastases and interleukin 1 this precipitates acute and rapid decline in joint function and degradation of joint anatomy subsequently disruption of the rotator cuff ensues along with symptomatology the disease typically presents with positive radiologic findings often showing marked erosion of the humeral head cartilage capsule and bursae though rare it is most often seen in females beginning in their 50 s or 60 s diagnosis is made with arthrocentesis and alizarin red staining along with clinical symptoms
min min is an unusual light phenomenon that has often been reported in outback australia the name min min derives from the small settlement of min min located between the outback towns of boulia and winton where the light was observed by a stockman in 1918 stories about the lights can be found in aboriginal myths pre dating european settlement and have since become part of wider australian folklore indigenous australians hold that the number of sightings has increased alongside the increasing ingression of europeans into the outback according to folklore the lights sometimes follow or approached people and have disappeared sometimes very rapidly when fired upon only to reappear later on the first recorded sighting dates to 1838 in the book six months in south australia
the minakshisundaram – pleijel zeta function is a zeta function encoding the eigenvalues of the laplacian of a compact riemannian manifold it was introducedby subbaramiah minakshisundaram and åke pleijel the case of a compact region of the plane was treated earlier by
minamata disease japanese 水俣病 hepburn minamata byō sometimes referred to as chisso minamata disease チッソ水俣病 chisso minamata byō is a neurological syndrome caused by severe mercury poisoning symptoms include ataxia numbness in the hands and feet general muscle weakness loss of peripheral vision and damage to hearing and speech in extreme cases insanity paralysis coma and death follow within weeks of the onset of symptoms a congenital form of the disease can also affect fetuses in the womb minamata disease was first discovered in minamata city in kumamoto prefecture japan in 1956 it was caused by the release of methylmercury in the industrial wastewater from the chisso corporation s chemical factory which continued from 1932 to 1968 this highly toxic chemical bioaccumulated in shellfish and fish in minamata bay and the shiranui sea which when eaten by the local populace resulted in mercury poisoning while cat dog pig and human deaths continued for 36 years the government and company did little to prevent the pollution the animal effects were severe enough in cats that they came to be named as having dancing cat fever as of march 2001 2 265 victims had been officially recognised as having minamata disease 1 784 of whom had died and over 10 000 had received financial compensation from chisso by 2004 chisso corporation had paid 86 million in compensation and in the same year was ordered to clean up its contamination on march 29 2010 a settlement was reached to compensate as yet uncertified victims a second outbreak of minamata disease occurred in niigata prefecture in 1965 the original minamata disease and niigata minamata disease are considered two of the four big pollution diseases of japan
the mind – body problem is the problem of explaining how mental states events and processes — like beliefs actions and thinking — are related to the physical states events and processes given that the human body is a physical entity and the mind is non physical the problem was addressed by rené descartes in the 17 th century resulting in cartesian dualism and by pre aristotelian philosophers in avicennian philosophy and in earlier asian traditions a variety of approaches have been proposed most are either dualist or monist dualism maintains a rigid distinction between the realms of mind and matter monism maintains that there is only one unifying reality substance or essence in terms of which everything can be explained each of these categories contain numerous variants the two main forms of dualism are substance dualism which holds that the mind is formed of a distinct type of substance not governed by the laws of physics and property dualism which holds that mental properties involving conscious experience are fundamental properties alongside the fundamental properties identified by a completed physics the three main forms of monism are physicalism which holds that the mind consists of matter organized in a particular way idealism which holds that only thought truly exists and matter is merely an illusion and neutral monism which holds that both mind and matter are aspects of a distinct essence that is itself identical to neither of them several philosophical perspectives have been developed which reject the mind – body dichotomy the historical materialism of karl marx and subsequent writers itself a form of physicalism held that consciousness was engendered by the material contingencies of one s environment an explicit rejection of the dichotomy is found in french structuralism and is a position that generally characterized post war french philosophy the absence of an empirically identifiable meeting point between the non physical mind and its physical extension has proven problematic to dualism and many modern philosophers of mind maintain that the mind is not something separate from the body these approaches have been particularly influential in the sciences particularly in the fields of sociobiology computer science evolutionary psychology and the neurosciences an ancient model of the mind known as the five aggregate model explains the mind as continuously changing sense impressions and mental phenomena considering this model it is possible to understand that it is the constantly changing sense impressions and mental phenomena i e the mind that experiences analyzes all external phenomena in the world as well as all internal phenomena including the body anatomy the nervous system as well as the organ brain this conceptualization leads to two levels of analyses i analyses conducted from a third person perspective on how the brain works and ii analyzing the moment to moment manifestation of an individual ’ s mind stream analyses conducted from a first person perspective considering the latter the manifestation of the mind stream is described as happening in every person all the time even in a scientist who analyses various phenomena in the world including analyzing and hypothesizing about the organ brain
mineral hydration is an inorganic chemical reaction where water is added to the crystal structure of a mineral usually creating a new mineral usually called a hydrate in geological terms the process of mineral hydration is known as retrograde alteration and is a process occurring in retrograde metamorphism it commonly accompanies metasomatism and is often a feature of wall rock alteration around ore bodies hydration of minerals occurs generally in concert with hydrothermal circulation which may be driven by tectonic or igneous activity mineral hydration is also a process in the regolith that results in conversion of silicate minerals into clay minerals there are two main ways in which minerals hydrate one is conversion of an oxide to a double hydroxide as with the hydration of calcium oxide — cao — to calcium hydroxide — ca oh 2 the other is with the incorporation of water molecules directly into the crystalline structure of a new mineral as in the hydration of feldspars to clay minerals garnet to chlorite or kyanite to muscovite some mineral structures for example montmorillonite are capable of including a variable amount of water without significant change to the mineral structure hydration is the mechanism by which hydraulic binders such as portland cement develop strength a hydraulic binder is a material that can set and harden submerged in water by forming insoluble products in a hydration reaction the term hydraulicity or hydraulic activity is indicative of the chemical affinity of the hydration reaction
in geology mineralization is the deposition of economically important metals in the formation of ore bodies or lodes by various process the first scientific studies of this process took place in the english county of cornwall by j w henwood frs and later by r w fox frs the term can also refer to the process by which waterborne minerals such as calcium carbonate calcite iron oxide hematite or limonite or silica quartz replace organic material within the body of an organism that has died and was buried by sediments mineralization may also refer to the product resulting from the process of mineralization for example mineralization the process may introduce metals such as iron into a rock that rock may then be referred to as possessing iron mineralization
a miniature effect is a special effect created for motion pictures and television programs using scale models scale models are often combined with high speed photography or matte shots to make gravitational and other effects appear convincing to the viewer the use of miniatures has largely been superseded by computer generated imagery in the contemporary cinema where a miniature appears in the foreground of a shot this is often very close to the camera lens — for example when matte painted backgrounds are used since the exposure is set to the object being filmed so the actors appear well lit the miniature must be over lit in order to balance the exposure and eliminate any depth of field differences that would otherwise be visible this foreground miniature usage is referred to as forced perspective another form of miniature effect uses stop motion animation use of scale models in the creation of visual effects by the entertainment industry dates back to the earliest days of cinema models and miniatures are copies of people animals buildings settings and objects miniatures or models are used to represent things that do not really exist or that are too expensive or difficult to film in reality such as explosions floods or fires
minimal change disease mcd also known as nil disease or by is a kidney disease that causes nephrotic syndrome and usually affects children with peak incidence at ages 2 to 3 years the disease degrades the kidney s ability to filter and the impaired renal function causes edema
minimal mesangial glomerulonephritis is a type of glomerulonephritis is seen in 10 to 25 of sle cases and is associated with mild clinical symptoms immune complexes deposit in the mesangium with a slight increase in the mesangial matrix and cellularity
a minimally conscious state mcs is a disorder of consciousness distinct from persistent vegetative state and locked in syndrome unlike persistent vegetative state patients with mcs have partial preservation of conscious awareness mcs is a relatively new category of disorders of consciousness the natural history and longer term outcome of mcs have not yet been thoroughly studied the prevalence of mcs was estimated to be 112 000 to 280 000 in adult and pediatric cases
minimally differentiated acute myeloblastic leukemia is a subtype of aml it is classified as m 0 by fab it represents 2 – 3 of all cases of aml although minimally differentiated aml was recognized earlier criteria for fab m 0 were developed in 1991 the blasts in these cases cannot be recognized as myeloid based on morphology and cytochemistry but immunophenotyping demonstrates myeloid antigens
in computational geometry and computer science the minimum weight triangulation problem is the problem of finding a triangulation of minimal total edge length that is an input polygon or the convex hull of an input point set must be subdivided into triangles that meet edge to edge and vertex to vertex in such a way as to minimize the sum of the perimeters of the triangles the problem is np hard for point set inputs but may be approximated to any desired degree of accuracy for polygon inputs it may be solved exactly in polynomial time the minimum weight triangulation has also sometimes been called the optimal triangulation
the minimum design metal temperature mdmt is one of the design conditions for pressure vessels engineering calculations design and manufacturing according to the asme boilers and pressure vessels code each pressure vessel that conforms to the asme code has its own mdmt and this temperature is stamped on the vessel nameplate the precise definition can sometimes be a little elaborate but in simple terms the mdmt is a temperature arbitrarily selected by the user of the vessel according to the type of fluid and the temperature range the vessel is going to handle the so called arbitrary mdmt must be lower than or equal to the cet which is an environmental or process property see below and must be higher than or equal to the mdmt m which is a material property critical exposure temperature cet is the lowest anticipated temperature to which the vessel will be subjected taking into consideration lowest operating temperature operational upsets autorefrigeration atmospheric temperature and any other sources of cooling in some cases it may be the lowest temperature at which significant stresses will occur and not the lowest possible temperature mdmt m is the lowest temperature permitted according to the metallurgy of the vessel fabrication materials and the thickness of the vessel component that is according to the low temperature embrittlement range and the charpy impact test requirements per temperature and thickness for each one of the vessel s components
minimum ignition energy mie is the minimum amount of energy required to ignite a combustible vapor gas or dust cloud for example by means of an electrostatic discharge ignition of a fuel air mixture is possible only when the rate of liberation of heat near the ignition zone is greater than the heat loss by conduction heat loss due to radiation is not considered as it is assumed to be negligible and the ignition process is assumed to be steady and one dimensional mie is measured in joules j explosives hydrogen unsaturated hydrocarbons and alkanes in oxygen have the lowest mie in the range of 1 to 100 μj alkanes in air distillate fuels hybrid mixtures and extremely sensitive dusts have a mie range of 0 1 to 10 mj combustible dusts have a mie range of 0 01 to 10 j for most materials the stoichiometric concentration can be calculated from the carbon and hydrogen content and is typically about twice the lower flammable limit lfl the lowest ignition energy value rarely occurs at the stoichiometric combustion concentration for heavier gasses the minimum usually occurs slightly above stoichiometric concentration and for lighter gasses such as hydrogen slightly below
in mathematics the minimum k cut is a combinatorial optimization problem that requires finding a set of edges whose removal would partition the graph to k connected components these edges are referred to as k cut the goal is to find the minimum weight k cut this partitioning can have applications in vlsi design data mining finite elements and communication in parallel computing
in number theory the minimum overlap problem is a problem proposed by hungarian mathematician paul erdős in 1955
the minisci reaction italian miˈniʃi is a named reaction in organic chemistry it is a radical substitution to an aromatic compound in particular to a heteroaromatic base that introduces an alkyl group the reaction was published about in 1971 by f minisci the aromatic compound is generally electron deficient and with n aromatic compounds the nitrogen atom is protonated a typical reaction is that between pyridine and pivalic acid to 2 tert butylpyridine with silver nitrate sulfuric acid and ammonium persulfate the reaction resembles friedel crafts alkylation but with opposite reactivity and selectivity the minisci reaction proceeds regioselectively and enables the introduction of a wide range of alkyl groups a side reaction is acylation the ratio between alkylation and acylation depends on the substrate and the reaction conditions due to the simple raw materials and the simple reaction conditions the reaction has many applications in heterocyclic chemistry reaction between pyridine and pivalic acid to 2 tert butylpyridine
the minoan eruption of thera also referred to as the thera eruption or santorini eruption was a major catastrophic volcanic eruption with a volcanic explosivity index vei of 6 or 7 and a dense rock equivalent dre of 60 km 3 14 cu mi dated to the mid second millennium bce the eruption was one of the largest volcanic events on earth in recorded history it devastated the island of thera now called santorini including the minoan settlement at akrotiri and communities and agricultural areas on nearby islands and the coast of crete with a related earthquake or tsunami there are no clear ancient records of the eruption which may have inspired certain greek myths caused turmoil in egypt and be alluded to in a
minor s disease a syndrome involving the sudden onset of back pain and paralysis caused by haemorrhage into the spinal cord substance was named after the russian neurologist lazar salomowitch minor 1855 – 1942 the term minor s syndrome is now only rarely used in connection with his work and is increasingly being used both inside and outside the medical profession to refer to superior canal dehiscence syndrome scds first described in 1998 by dr lloyd b minor of the johns hopkins university baltimore usa
minor depressive disorder also known as minor depression is a mood disorder that does not meet the full criteria for major depressive disorder but at least two depressive symptoms are present for two weeks these symptoms can be seen in many different psychiatric and mental disorders which can lead to more specific diagnoses of an individual s condition however some of the situations might not fall under specific categories listed in the diagnostic and statistical manual of mental disorders minor depressive disorder is an example of one of these nonspecific diagnoses as it is a disorder classified in the dsm iv tr under the category depressive disorder not otherwise specified dd nos the classification of nos depressive disorders is up for debate minor depressive disorder as a term was never an officially accepted term but was listed in appendix b of the dsm iv tr this is the only version of the dsm that contains the term as the prior versions and the most recent edition dsm 5 does not mention it a person is considered to have minor depressive disorder if he or she experiences 2 to 4 depressive symptoms with one of them being either depressed mood or loss of interest or pleasure during a 2 week period the person must not have experienced the symptoms for 2 years and there must not a one specific event that caused the symptoms to arise although not all cases of minor depressive disorder are deemed in need of treatment some cases are treated similarly to major depressive disorder this treatment includes cognitive behavioral therapy cbt anti depressant medication and combination therapy a lot of research supports the notion that minor depressive disorder is an early stage of major depressive disorder or that it is simply highly predictive of subsequent major depressive disorder
a minsky moment is a sudden major collapse of asset values which is part of the credit cycle or business cycle such moments occur because long periods of prosperity and increasing value of investments lead to increasing speculation using borrowed money the spiraling debt incurred in financing speculative investments leads to cash flow problems for investors the cash generated by their assets no longer is sufficient to pay off the debt they took on to acquire them losses on such speculative assets prompt lenders to call in their loans this is likely to lead to a collapse of asset values meanwhile the over indebted investors are forced to sell even their less speculative positions to make good on their loans however at this point no counterparty can be found to bid at the high asking prices previously quoted this starts a major sell off leading to a sudden and precipitous collapse in market clearing asset prices a sharp drop in market liquidity and a severe demand for cash a more general meaning is to say that a minsky cycle features a series of minsky moments in which a period of stability encourages risk taking which leads to a period of instability which causes more conservative and risk averse de leveraging behavior until stability is restored continuing the cycle in this more general view the minsky cycle may apply to a wide range of human activities beyond investment economics the term was coined by paul mcculley of pimco in 1998 to describe the 1998 russian financial crisis and was named after economist dr hyman minsky who noted that bankers traders and other financiers periodically played the role of arsonists setting the entire economy ablaze minsky opposed the deregulation that characterized the 1980 s some such as mcculley have dated the start of the financial crisis of 2007 – 2010 to a minsky moment and called the following crisis a reverse minsky journey mcculley dates the moment to august 2007 while others date the start to some months earlier or later such as the june 2007 failure of two bear stearns funds the concept has some parallels with austrian business cycle theory although minsky himself was known as a keynesian and is identified as a post keynesian — as is mcculley
miosis or myosis maɪˈoʊ sɪs from ancient greek μύειν mūein to close the eyes is a term with various definitions which generally include constriction of the pupil the opposite condition mydriasis is the dilation of the pupil anisocoria is the condition of one pupil being more dilated than the other
mirhosseini – holmes – walton syndrome is a syndrome which involves retinal degeneration cataract microcephaly and mental retardation it was first characterized in 1972 the gene or genes involved have not yet been determined there is some evidence that this syndrome has the same genetic cause as cohen syndrome
mirizzi s syndrome is a rare complication in which a gallstone becomes impacted in the cystic duct or neck of the gallbladder causing compression of the common bile duct cbd or common hepatic duct resulting in obstruction and jaundice the obstructive jaundice can be caused by direct extrinsic compression by the stone or from fibrosis caused by chronic cholecystitis inflammation a cholecystocholedochal fistula can occur
mirror touch synesthesia is a condition which causes individuals to experience the same sensation such as touch that another person feels for example if someone with this condition were to observe someone touching their cheek they would feel the same sensation on their own cheek synesthesia in general is described as a condition in which a stimulus causes an individual to experience an additional sensation synesthesia is usually a developmental condition however recent research has shown that mirror touch synesthesia can be acquired after sensory loss following amputation
mirror movements are characterized by involuntary movements on one side of the body mirroring voluntary movements on the other for example if someone wanted to pick up a pencil with their left hand then their right hand would also reach out for the same pencil this mostly affects the top half of the body but can also affect the bottom half walking may become more difficult as one leg will move at the same time as the other playing a musical instrument such as the piano may become very difficult as the process involves doing different things with each hand
mirror syndrome or triple oedema or ballantyne syndrome is a rare disorder affecting pregnant women it describes the unusual association of fetaland placental hydrops with maternal preeclampsia the name mirror syndrome refers to the similarity between maternal oedema and fetal hydrops it was first described in 1892 by john william ballantyne
the misalignment mechanism is a hypothesized effect in the peccei – quinn theory proposed solution to the strong cp problem in quantum mechanics the effect occurs when a particle s field has an initial value that is not at or near a potential minimum this causes the particle s field to oscillate around the nearest minimum eventually dissipating energy by decaying into other particles until the minimum is attained in the case of hypothesized axions created in the early universe the initial values are random because of the masslessness of axions in the high temperature plasma near the critical temperature of quantum chromodynamics axions possess a temperature dependent mass that enters a damped oscillation until the potential minimum is reached
miscarriage also known as spontaneous abortion and pregnancy loss is the natural death of an embryo or fetus before it is able to survive independently some use the cutoff of 20 weeks of gestation after which fetal death is known as a stillbirth the most common symptoms of a miscarriage is vaginal bleeding with or without pain sadness anxiety and guilt may occur tissue or clot like material may also come out of the vagina risk factors for miscarriage include an older parent previous miscarriage exposure to tobacco smoke obesity diabetes and drug or alcohol use among others in those under the age of 35 the risk is about 10 while it is about 45 in those over the age of 40 risk begins to increase around the age of 30 about 80 of miscarriages occur in the first 12 weeks of pregnancy the first trimester the underlying cause in about half of cases involves chromosomal abnormalities other conditions that can produce similar symptoms include an ectopic pregnancy and implantation bleeding diagnosis of a miscarriage may involve checking to see if the cervix is open or closed testing blood levels of human chorionic gonadotropin hcg and an ultrasound prevention is occasionally possible with good prenatal care avoiding drugs and alcohol infectious diseases and radiation may prevent miscarriage no specific treatment is usually needed during the first 7 to 14 days most miscarriage will complete without additional interventions occasionally the medication misoprostol or a procedure such as vacuum aspiration is required to remove the failed pregnancy women who are rhesus negative may require rho d immune globulin pain medication may be beneficial emotional support may help with negative emotions miscarriage is the most common complication of early pregnancy among females who know they are pregnant the miscarriage rate is roughly 10 to 20 while rates among all fertilisation is around 30 to 50 about 5 of females have two miscarriages in a row some recommend not using the term abortion in discussions with those experiencing a miscarriage in an effort to decrease distress
misfeasance in public office is a cause of action in the civil courts of england and wales and certain commonwealth countries it is an action against the holder of a public office alleging in essence that the office holder has misused or abused their power the tort can be traced back to 1703 when chief justice sir john holt decided that a landowner could sue a police constable who deprived him of his right to vote ashby v white the tort was revived in 1985 when it was used so that french turkey producers could sue the ministry of agriculture over a dispute that harmed their sales generally a civil defendant will be liable for misfeasance if the defendant owed a duty of care toward the plaintiff the defendant breached that duty of care by improperly performing a legal act and the improper performance resulted in harm to the plaintiff in theory misfeasance is distinct from nonfeasance nonfeasance is a term that describes a failure to act that results in harm to another party misfeasance by contrast describes some affirmative act that though legal causes harm in practice the distinction is confusing and uninstructive courts often have difficulty determining whether harm resulted from a failure to act or from an act that was improperly performed
the mislow – evans rearrangement is a name reaction in organic chemistry it is named after kurt mislow and david evans who discovered this reaction in 1971 the reaction allows the formation of allylic alcohols from allylic sulfoxides in a 2 3 sigmatropic rearrangement
mismatch loss in transmission line theory is the amount of power expressed in decibels that will not be available on the output due to impedance mismatches and signal reflections a transmission line that is properly terminated that is terminated with the same impedance as that of the characteristic impedance of the transmission line will have no reflections and therefore no mismatch loss mismatch loss represents the amount of power wasted in the system it can also be thought of as the amount of power gained if the system was perfectly matched impedance matching is an important part of rf system design however in practice there will likely be some degree of mismatch loss in real systems relatively little loss is due to mismatch loss and is often on the order of 1 db
mismatch repair cancer syndrome mmrcs is a cancer syndrome associated with biallelic dna mismatch repair mutations it is also known as turcot syndrome after jacques turcot who described the condition in 1959 and by several other names in mmrcs neoplasia typically occurs in both the gut and the central nervous system cns in the large intestine familial adenomatous polyposis occurs in the cns brain tumors
misophonia literally hatred of sound is a presumed disorder of uncertain classification in which negative emotions thoughts and physical reactions are triggered by specific sounds it is also called soft sound sensitivity syndrome select sound sensitivity syndrome 4 s decreased sound tolerance and sound rage misophonia is not recognized as a disorder by standard diagnostic criteria in the dsm 5 or the icd 10 and there is little research on its prevalence or treatment misophonia can adversely affect ability to achieve life goals and to enjoy social situations
the missionaries and cannibals problem and the closely related jealous husbands problem are classic river crossing problems the missionaries and cannibals problem is a well known toy problem in artificial intelligence where it was used by saul amarel as an example of problem representation
missouri lyme disease is a cutaneous condition the cause of ‘ missouri lyme disease ’ has been a source of controversy true lyme disease probably occurs in missouri and other southern states although lyme disease like illnesses not related to borrelia burgdorferi also occur strains of b burgdorferi have been isolated from a americanum in missouri but the ticks are not efficient disease vectors
the missouri bellwether is a political phenomenon that notes that the state of missouri voted for the winner in all but one u s presidential election from 1904 to 2004 the exception is 1956 while states like ohio iowa nevada and new mexico have been arguably stronger indicators of political trends in recent years missouri was a consistent swing state throughout the 20 th century nevada has voted for the winner of every presidential election from united states presidential election 1912 to the present excluding united states presidential election 1976 perhaps making it the new bellwether state prior to the 2008 elections lincoln county missouri was said to be the only bellwether county in a bellwether state missouri is also considered a bellwether of u s views on hot button social issues such as stem cell research gay rights and school vouchers some economists also consider the state a bellwether for economic trends such as consumer confidence and unemployment
mist is a phenomenon caused by small droplets of water suspended in air physically it is one instance of a dispersion it is most commonly seen where warm moist air meets sudden cooling such as in exhaled air in the winter or when throwing water onto the hot stove of a sauna it is often created artificially with aerosol canisters if the humidity and temperature conditions are right it can also occur as part of natural weather when humid air cools rapidly for example when the air comes into contact with surfaces that are much cooler than the air the formation of mist as of other suspensions is greatly aided by the presence of nucleation sites on which the suspended water phase can congeal thus even such unusual sources as small particulates from volcanic eruptions releases of strongly polar gases and even the magnetospheric ions associated with polar lights can in right conditions trigger the formation of mist
mitochondrial disease is a group of disorders caused by dysfunctional mitochondria the organelles that generate energy for the cell mitochondria are found in every cell of the human body except red blood cells and convert the energy of food molecules into the atp that powers most cell functions mitochondrial diseases are sometimes about 15 of the time caused by mutations in the mitochondrial dna that affect mitochondrial function other causes of mitochondrial disease are mutations in genes of the nuclear dna whose gene products are imported into the mitochondria mitochondrial proteins as well as acquired mitochondrial conditions mitochondrial diseases take on unique characteristics both because of the way the diseases are often inherited and because mitochondria are so critical to cell function the subclass of these diseases that have neuromuscular disease symptoms are often called a mitochondrial myopathy
mitochondrial myopathies are types of myopathies associated with mitochondrial disease on biopsy the muscle tissue of patients with these diseases usually demonstrate ragged red muscle fibers these ragged red fibers contain mild accumulations of glycogen and neutral lipids and may show an increased reactivity for succinate dehydrogenase and a decreased reactivity for cytochrome c oxidase inheritance is maternal non mendelian extranuclear there are several subcategories of mitochondrial myopathies
mitochondrial neurogastrointestinal encephalopathy syndrome mngie is a rare autosomal recessive mitochondrial disease it has been previously referred to as polyneuropathy ophthalmoplegia leukoencephalopathy and polip syndrome the disease presents in childhood but often goes unnoticed for decades unlike typical mitochondrial diseases caused by mitochondrial dna mtdna mutations mngie is caused by mutations in the tymp gene which encodes the enzyme thymidine phosphorylase mutations in this gene result in impaired mitochondrial function leading to intestinal symptoms as well as neuro ophthalmologic abnormalities a secondary form of mngie called mngie without leukoencephalopathy can be caused by mutations in the polg gene
mitochondrial toxicity is a condition in which the mitochondria of a body s cells become damaged or decline significantly in number it occurs as a side effect of certain antiretroviral drugs used to treat human immunodeficiency virus or hiv
mitochondrial trifunctional protein deficiency is an autosomal recessive fatty acid oxidation disorder that prevents the body from converting certain fats to energy particularly during periods without food people with this disorder have inadequate levels of an enzyme that breaks down a certain group of fats called long chain fatty acids
mitral insufficiency mi mitral regurgitation or mitral incompetence is a disorder of the heart in which the mitral valve does not close properly when the heart pumps out blood it is the abnormal leaking of blood backwards from the left ventricle through the mitral valve into the left atrium when the left ventricle contracts i e there is regurgitation of blood back into the left atrium mi is the most common form of valvular heart disease
mitral valve prolapse mvp a k a floppy mitral valve syndrome systolic click murmur syndrome or billowing mitral leaflet is a valvular heart disease characterized by the displacement of an abnormally thickened mitral valve leaflet into the left atrium during systole it is the primary form of myxomatous degeneration of the valve there are various types of mvp broadly classified as classic and nonclassic in its nonclassic form mvp carries a low risk of complications and often can be kept minimal by dietary attention in severe cases of classic mvp complications include mitral regurgitation infective endocarditis congestive heart failure and in rare circumstances cardiac arrest the diagnosis of mvp depends upon echocardiography which uses ultrasound to visualize the mitral valve the prevalence of mvp is estimated at 2 3 of the population the condition was first described by john brereton barlow in 1966 in consequence it may also be referred to as barlow s syndrome and was subsequently termed mitral valve prolapse by j michael criley
mitral stenosis is a valvular heart disease characterized by the narrowing of the orifice of the mitral valve of the heart
the mitsunobu reaction is an organic reaction that converts an alcohol into a variety of functional groups such as an ester using triphenylphosphine and an azodicarboxylate such as diethyl azodicarboxylate dead or diisopropyl azodicarboxylate diad the alcohol undergoes an inversion of stereochemistry it was discovered by oyo mitsunobu 1934 – 2003 the mitsunobu reaction several reviews have been published
mittelschmerz german middle pain is a medical term for ovulation pain or midcycle pain about 20 of women experience mittelschmerz some every cycle some intermittently
a malignant mixed müllerian tumor also known as malignant mixed mesodermal tumor mmmt and carcinosarcoma is a malignant neoplasm found in the uterus the ovaries the fallopian tubes and other parts of the body that contains both carcinomatous epithelial tissue and sarcomatous connective tissue components it is divided into two types homologous in which the sarcomatous component is made of tissues found in the uterus such as endometrial fibrous and or smooth muscle tissues and a heterologous type made up of tissues not found in the uterus such as cartilage skeletal muscle and or bone mmmt account for between two and five percent of all tumors derived from the body of the uterus and are found predominantly in postmenopausal women with an average age of 66 years risk factors are similar to those of adenocarcinomas and include obesity exogenous estrogen therapies and nulliparity less well understood but potential risk factors include tamoxifen therapy and pelvic irradiation
traditionally a mixed affective state formerly known as a mixed manic or mixed episode has been defined as a state wherein features unique to both depression and mania — as despair fatigue morbid or suicidal ideation racing thoughts pressure of activity and heightened irritability — occur either simultaneously or in very short succession previously the diagnostic criteria for both a manic and depressive episode had to be met in a consistent and sustained fashion with symptoms enduring for at least a week or any duration if psychiatric hospitalization was required thereby restricting the official acknowledgement of mixed affective states to only a minority of patients with bipolar i disorder in current dsm v nomenclature however a mixed episode no longer stands as an episode of illness unto itself rather the symptomology specifier with mixed features can be applied to any major affective episode manic hypomanic or depressive meaning that they are now officially recognized in patients with in addition to bipolar i disorder bipolar ii disorder and by convention major depressive disorder a depressive mixed state in a patient however even in the absence of discrete periods of mania or hypomania argues strongly against a unipolar course and for a bipolar one although convention dictates diagnosing such patients with major depressive disorder it may be appropriate to classify such a patient as having an other specified bipolar or related disorder and certainly following up such patients in the long term to ascertain the eventual appearance of an episode of mania or hypomania with or without mixed features which would prompt diagnostic revision in those uncommon cases wherein the diagnostic criteria for both a manic and depressive episode are met constituting what were heretofore classified as mixed episodes such a patient would be diagnosed as having a manic episode with mixed features because of the substantial social and occupational dysfunction inherent in such a state
in medicine mixed connective tissue disease also known as sharp s syndrome commonly abbreviated as mctd is an autoimmune disease in which the body s defense system attacks itself it was characterized in 1972 and the term was introduced by leroy in 1980 it is sometimes said to be the same as undifferentiated connective tissue disease but other experts specifically reject this idea because undifferentiated connective tissue disease is not necessarily associated with serum antibodies directed against the u 1 rnp and mctd is associated with a more clearly defined set of signs symptoms
mixed receptive expressive language disorder dsm iv 315 32 is a communication disorder in which both the receptive and expressive areas of communication may be affected in any degree from mild to severe if assessed on the wechsler adult intelligence scale for instance symptoms may show as relatively low scores for information vocabulary and comprehension perhaps below the 25 th percentile if a person has difficulty with spatial concepts such as over under here and there they may have difficulties with arithmetic understanding word problems and instructions or difficulties using words they may also have a more general problem with words or sentences both comprehension and orally if suspected of having a mixed receptive expressive language disorder treatment is available from a speech therapist or pathologist most treatments are short term and rely upon accommodations made within the environment in order to minimise interfering with work or school
a mixed tumor is a tumor that derives from multiple tissue types for example a chondroid syringoma is a cutaneous condition characterized histologically by nests of cuboidal or polygonal epithelial cells in the dermis there are two types one derived from a single germ cell layer that differentiates into more than one cell type and one derived from more than one germ cell layer totipotent cells
the mizuo – nakamura phenomenon is a phenomenon observed in oguchi s disease it was named after gentaro mizuo 1876 – 1913 and bunpei nakamura 1886 – 1969 japanese ophthalmologists oguchi disease is characterized by a golden brown fundus with a yellow gray metallic sheen in the light adapted state after complete dark adaptation 3 to 12 hours the fundus appears normal and this disappearance of the shiny yellow fundus reflex is called the mizuo – nakamura phenomenon
in computing b mkstemp b is a posix function for creating a temporary file a computer file which usually ceases to exist when the program which opened the file closes it or terminates
mobile internet growth is the growth of the internet when accessed via a mobile phone laptop etc at one time half the world had mobile phones the articles in 2007 2008 were slightly misleading because the real story at the time was that the number of mobile phone subscriptions had reached half the population of the world in reality many people have more than one subscription for example in hong kong italy and ukraine the mobile phone penetration rate has passed 140 source wireless intelligence 2009 by 2009 even the number of unique users of mobile phones had reached half the planet when the itu reported that the subscriber number was to reach 4 6 billion user which means 3 8 billion activated mobile phones in use and 3 4 billion unique users of mobile phones the mobile internet data connections are following the growth of mobile phone connections albeit at a lower rate in 2009 yankee group reported that 29 of all mobile phone users globally were accessing browser based internet content on their phones according to the bbc there are now 2010 over 5 billion mobile phone users in the world
mobile instant messaging mim is a presence enabled messaging service that aims to transpose the internet desktop messaging such as icq or msn experience to the usage scenario of being connected via a mobile cellular device while several of the core ideas of the desktop im experience and functionality on one hand apply to a connected mobile device others do not users usually only look at their phone s screen — presence status changes might occur under different circumstances as happens at the desktop and several functional limits exist based on the fact that the vast majority of mobile communication devices are chosen by their users to fit into the palm of their hand some of the form factor and mobility related differences need to be taken into account in order to create a really adequate powerful and yet convenient mobile experience radio bandwidth memory size availability of media formats keypad based input screen output cpu performance and battery power are core issues that desktop device users and even nomadic users with connected notebooks are usually not exposed to there are two distinct methods to enable mobile instant messaging embedded clients – tailored im client for every specific device with a special backend server installed within the cellular operator s service clientless platform – a browser based application without downloading any software to the handset or need for any technical support by the cellular operator which enables all users all devices and from any network to connect to their internet im service by all communication market analysts the clientless platform is by far the more preferred method between the two the embedded clients cost for installment technical and consumer support embedded clients are simply too expensive to develop and deploy for the cellular operator on the other hand the clientless platform enables full interoperability between networks and communication platforms – at no technical and consumer support in the past microsoft aol have tried to develop such a solution with minor success but since the popularity of 2 5 generation cellular handsets and even more so since the appearance of the 3 g technology – enabling fast data trafficking – will finally enable widespread mim usage
mobile phone overuse or problem mobile phone use is a dependence syndrome seen among certain mobile phone users some mobile phone users exhibit problematic behaviors related to substance use disorders these behaviors can include preoccupation with mobile communication excessive money or time spent on mobile phones use of mobile phones in socially or physically inappropriate situations such as driving an automobile increased use can also lead to increased time on mobile communication adverse effects on relationships and anxiety if separated from a mobile phone or sufficient signal
a mod or modification is the alteration of content from a video game in order to make it operate in a manner different from its original version mods can be created for any genre of game but are especially popular in first person shooters role playing games and real time strategy games mods are made by the general public or a developer and can be entirely new games in themselves but mods are not stand alone software and require the user to have the original release in order to run they can include new items modded weapons characters enemies models textures levels story lines music money armor life and game modes they can be single player or multiplayer mods that add new content to the underlying game are often called partial conversions while mods that create an entirely new game are called total conversions and mods that fix bugs only are called unofficial patches games running on a personal computer are often designed with change in mind allowing modern pc games to be modified by gamers without much difficulty these mods can add extra replay value and interest the internet provides an inexpensive medium to promote and distribute user created content like mods an aspect commonly known as web 2 0 video game modding was described as remixing of games and can be therefore seen as part of the remix culture as described by lawrence lessig the mods have become an increasingly important factor in the commercial success of some games developers such as id software valve corporation mojang ab bethesda softworks firaxis crytek the creative assembly and epic games provide extensive tools and documentation to assist mod makers leveraging the potential success brought in by a popular mod like counter strike mods can help to continue the success of the original game even when the original game has become dated in that case players might have to clarify that they are referring to the unmodified game when talking about playing a game the term vanilla is often used to make this distinction vanilla battlefield 1942 for example refers to the original unmodified game for vanilla games prefix v or v is commonly used together with the game title acronym e g vq 3 stands for vanilla quake 3 as early as the 1980 s video game mods have been used for the sole purpose of creating art as opposed to an actual game they can include recording in game action as a film as well as attempting to reproduce real life areas inside a game with no regard for game play value see also artistic video game modification machinima and demoscene popular websites dedicated to modding include nexusmods and mod db
a model spectrum is an artificial spectrum of a star made by recreating the absorption or emission features seen in the spectrum a model spectrum will usually be of a specific spectral type of star and may include other properties of the star such as a surrounding nebula presence or lack of an extended atmosphere or a circumstellar dust disc some external reference links svo spectral models stars and galaxies kurucz models miles spectral models
model – view – adapter mva or mediating controller mvc is a software architectural pattern and multitier architecture in complex computer applications that present large amounts of data to users developers often wish to separate data model and user interface view concerns so that changes to the user interface will not affect data handling and that the data can be reorganized without changing the user interface mva and traditional mvc both attempt to solve this same problem but with two different styles of solution traditional mvc arranges model e g data structures and storage view e g user interface and controller e g business logic in a triangle with model view and controller as vertices so that some information flows between the model and views outside of the controller s direct control the model – view – adapter solves this rather differently from the model – view – controller by arranging model adapter or mediating controller and view linearly without any connections whatsoever directly between model and view
model – view – controller mvc is a software design pattern for implementing user interfaces on computers it divides a given software application into three interconnected parts so as to separate internal representations of information from the ways that information is presented to or accepted from the user traditionally used for desktop graphical user interfaces guis this architecture has become popular for designing web applications
modern typography was a reaction against the perceived decadence of typography and design of the late 19 th century it is mostly associated with the works of jan tschichold and bauhaus typographers herbert bayer lászló moholy nagy el lissitzky and others
modified wittig claisen tandem reaction is a cascade reaction that combines wittig reaction and claisen rearrangement together the wittig reaction generates the allyl vinyl ether intermediate that further participates in a claisen rearrangement to generate the final γ δ unsaturated ketone or aldehyde product figure modified wittig claisen tandem reactions the modified wittig claisen tandem reaction has been a useful retrosynthetic strategy and has been applied to the synthesis of various complex natural products and other molecules this reaction is especially useful for construction of cyclic ketones with double bond at the γ δ position paquette and co workers reported the synthesis of 4 cyclooctenone structure by expanding the six membered ring of a 2 cyclohexanone structure the key step was a tandem process that combines tebbe olefination a reaction similar to wittig reaction with claisen rearrangement figure application of modified wittig claisen tandem reactions for construction of 4 cyclooctenone structure tandem wittig claisen reaction has also been applied to the construction of the spiro pyrrolidin 3 3 ’ oxindole ring system in natural products such as horsfiline the synthesis started with a simple o nitrobenzaldehyde a wittig claisen reaction sequence converted the starting material to a 4 pentenal derivative that could serve as a versatile intermediate for the synthesis of various natural products in this case the 4 pentenal derivative was further converted to the natural product horsfiline the active ingredient of a traditional herbal medicine with analgesic effects
the modified lognormal power law mlp function is a three parameter function that can be used to model data that have characteristics of a lognormal distribution and a power law behavior it has been used to model the functional form of the initial mass function imf unlike the other functional forms of the imf the mlp is a single function with no joining conditions
in mathematics a modular form is a complex analytic function on the upper half plane satisfying a certain kind of functional equation with respect to the group action of the modular group and also satisfying a growth condition the theory of modular forms therefore belongs to complex analysis but the main importance of the theory has traditionally been in its connections with number theory modular forms appear in other areas such as algebraic topology sphere packing and string theory a modular function is a function that like a modular form is invariant with respect to the modular group but without the condition that f z be holomorphic at infinity instead modular functions are meromorphic at infinity modular form theory is a special case of the more general theory of automorphic forms and therefore can now be seen as just the most concrete part of a rich theory of discrete groups
in the fields of nonlinear optics and fluid dynamics modulational instability or sideband instability is a phenomenon whereby deviations from a periodic waveform are reinforced by nonlinearity leading to the generation of spectral sidebands and the eventual breakup of the waveform into a train of pulses the phenomenon was first discovered − and modelled − for periodic surface gravity waves stokes waves on deep water by t brooke benjamin and jim e feir in 1967 therefore it is also known as the benjamin − feir instability it is a possible mechanism for the generation of rogue waves
in software engineering the module pattern is a design pattern used to implement the concept of software modules defined by modular programming in a programming language with incomplete direct support for the concept this pattern can be implemented in several ways depending on the host programming language such as the singleton design pattern object oriented static members in a class and procedural global functions in python the pattern is built into the language and each py file is automatically a module
in algebra a module spectrum is a spectrum with an action of a ring spectrum it generalizes a module in abstract algebra the ∞ category of say right module spectra is stable hence it can be considered as either analog or generalization of the derived category of modules over a ring
in real analysis a branch of mathematics a modulus of convergence is a function that tells how quickly a convergent sequence converges these moduli are often employed in the study of computable analysis and constructive mathematics if a sequence of real numbers xi converges to a real number x then by definition for every real ε 0 there is a natural number n such that if i n then x − xi ε a modulus of convergence is essentially a function that given ε returns a corresponding value of n
mohawk – hudson convergence mhc is a mesoscale meteorology phenomenon occurring over the capital district region of upstate new york united states the small convergence zone forms within specific weather conditions sometimes found in the wake of extratropical cyclones shifting east of the area given air pressure decreasing with both longitude and latitude as well as weak synoptic low level flow winds are channeled east along the mohawk valley and south through the hudson valley converging over albany with sufficient moisture in the lower atmosphere a localized area of precipitation may form where the valleys meet extending for several miles around albany the process manifests primarily in the lowest 2 500 ft 760 m of the atmosphere mhc induced precipitation occurs predominately in the winter it typically produces low clouds and light snowfall often locally prolonging significant snow events by several hours the strongest mhc events may yield snowfall rates approaching 1 in 2 5 cm per hour occasionally mhc contributes to shower and thunderstorm formation in the warm season in early august 2008 two days of training thunderstorms over the capital district were attributed to mhc the result was locally heavy rain amounting to over 1 in 25 mm a relatively rare variation of mhc termed southern mohawk – hudson convergence smhc occurs in the summer when a southwesterly wind is present in advance of an approaching cold front in that scenario the hudson and mohawk valleys may direct the flow to become more southerly and westerly respectively yielding the formation of thunderstorms around albany when conditions permit as with mhc smhc is most pronounced in the absence of mechanisms for strong synoptic ascent over the region whereas the effects of the convergence zone are generally insignificant in the winter smhc presents more of a forecasting challenge when thunderstorms rapidly develop threaten and to impede travel at albany international airport thunderstorms associated with smhc have the potential to become severe
mohr – tranebjærg syndrome mts is a rare x liked recessive syndrome also known as deafness dystonia syndrome and caused by mutation in the timm 8 a gene it was first described in 1960 the severity of the symptoms may vary but they progress usually to severe deafness and dystonia and sometimes are accompanied by cortical deterioration of vision and mental deterioration
in mathematics physics and art a moiré pattern mwɑːrˈeɪ french mwaˈʁe or moiré fringes are large scale interference patterns that can be produced when an opaque ruled pattern with transparent gaps is overlaid on another similar pattern for the moiré interference pattern to appear the two patterns are not completely identical they must be displaced rotated etc or have different but similar pitch moiré patterns appear in many different situations in printing the printed pattern of dots can negatively interfere with the image in television and digital photography a pattern on an object being photographed can interfere with the shape of the light sensors to generate unwanted artifacts they are also sometimes created deliberately in micrometers they are used to amplify the effects of very small movements in physics its manifestation is the beat phenomenon that occurs in many wave interference conditions
molar pregnancy is an abnormal form of pregnancy in which a non viable fertilized egg implants in the uterus and will fail to come to term a molar pregnancy is a gestational trophoblastic disease which grows into a mass in the uterus that has swollen chorionic villi these villi grow in clusters that resemble grapes a molar pregnancy can develop when a fertilized egg does not contain an original maternal nucleus the products of conception may or may not contain fetal tissue it is characterized by the presence of a hydatidiform mole or hydatid mole mola hydatidosa molar pregnancies are categorized as partial moles or complete moles with the word mole being used to denote simply a clump of growing tissue or a growth a complete mole is caused by a single incidence is about 90 or two incidence is about 10 sperm combining with an egg which has lost its dna the sperm then reduplicates forming a complete 46 chromosome set the genotype is typically 46 xx diploid due to subsequent mitosis of the fertilizing sperm but can also be 46 xy diploid 46 yy diploid is not observed in contrast a partial mole occurs when a haploid egg is fertilized by two sperm or by one sperm which reduplicates itself yielding the genotypes of 69 xxy triploid or 92 xxxy tetraploid complete hydatidiform moles have 2 5 risk of developing into choriocarcinoma
alcoholism is characterized by a wide range of symptoms including compulsive alcohol seeking and consumption tolerance resistance to the effects of alcohol after repeated consumption and withdrawal symptoms such as irritability profuse sweating and uncontrollable shaking upon rapid cessation of drinking there is not a specific test for diagnosing alcoholism however patient questionnaires and medical screenings for ailments typically associated with alcoholism such as cirrhosis heart problems and pancreatitis are often used as diagnostic tools several factors influence the development of alcoholism including genetic predisposition and environmental stressors such as grief stress depression and anxiety in coordination with these factors molecular and epigenetic mechanisms influence the progression toward alcoholism
molecular autoionization or self ionization is a reaction between molecules of the same substance to produce ions if a pure liquid partially dissociates into ions it is said to be self ionizing the oxidation number on all atoms in such a reaction remains unchanged such autoionization can be protic h transfer or non protic some examples of each are protic solvents 2 h 2 o ⇌ h 3 o oh − the self ionization of water is particularly well studied due to its implications for acid base chemistry of aqueous solutions 2 nh 3 ⇌ nh 4 nh − 2 2 h 2 so 4 ⇌ h 3 so 4 hso − 4 3 hf ⇌ h 2 f hf − 2 here proton transfer between two hf combines with homoassociation of f − and a third hf to form hf − 2 non protic solvents 2 pf 5 ⇌ pf − 6 pf 42 n 2 o 4 ⇌ no no − 3 2 brf 3 ⇌ brf 2 brf − 4 the self ionization reaction 2 so 2 ⇌ so 2 − 3 so 2 has also been proposed but must be considered improbable because it would require the separation of doubly charged ions molecular autoionization can occur in gases or solids but occurs most readily in liquids in gases the molecules are so far apart that ion formation is very unfavorable and in solids there is not enough molecular movement as long as the phase remains constant autoionization normally increases substantially with increasing pressure
a molecular lesion or point lesion is damage to the structure of a biological molecule such as dna enzymes or proteins that results in reduction or absence of normal function or in rare cases the gain of a new function lesions in dna consist of breaks and other changes in the chemical structure of the helix see types of dna lesions while lesions in proteins consist of both broken bonds and improper folding of the amino acid chain
molecular modification is chemical alteration of a known and previously characterized lead compound for the purpose of enhancing its usefulness as a drug this could mean enhancing its specificity for a particular body target site increasing its potency improving its rate and extent of absorption modifying to advantage its time course in the body reducing its toxicity changing its physical or chemical properties like solubility to provide desired features
in chemistry a molecular orbital mo is a mathematical function describing the wave like behavior of an electron in a molecule this function can be used to calculate chemical and physical properties such as the probability of finding an electron in any specific region the term orbital was introduced by robert s mulliken in 1932 as an abbreviation for one electron orbital wave function at an elementary level it is used to describe the region of space in which the function has a significant amplitude molecular orbitals are usually constructed by combining atomic orbitals or hybrid orbitals from each atom of the molecule or other molecular orbitals from groups of atoms they can be quantitatively calculated using the hartree – fock or self consistent field scf methods
molecular vapor deposition is the gas phase reaction between surface reactive chemicals and an appropriately receptive surface often bi functional silanes are used in which one termination of the molecule is reactive for example a functional chlorosilane r si cl 3 can react with surface hydroxyl groups oh resulting a radicalized r deposition on the surface the advantage of a gas phase reaction over a comparable liquid phase process is the control of moisture from the ambient environment which often results in cross polymerization of the silane leading to particulates on the treated surface often a heated sub atmospheric vacuum chamber is used to allow precise control of the reactants and water content additionally the gas phase process allows for easy treatment of complex parts since the coverage of the reactant is generally diffusion limited microelectromechanical systems mems sensors often use molecular vapor deposition as a technique to address stiction and other parasitic issues relative to surface to surface interactions
in mathematics a molien series is a generating function attached to a linear representation ρ of a group g on a finite dimensional vector space v it counts the homogeneous polynomials of a given total degree d that are invariants for g it is named for theodor molien
a molineux hearing is a new york state pre trial hearing on the admissibility of evidence of prior uncharged crimes by the defendant in a criminal trial in most cases evidence of prior uncharged crimes is not admissible because of its potential prejudicial effect under certain circumstances it may be admissible if the prosecutor wishes to bring in evidence of prior uncharged crimes they request a molineux hearing the judge decides if the evidence is admissible
mollaret s meningitis is a recurrent or chronic inflammation of the protective membranes covering the brain and spinal cord known collectively as the meninges since mollaret s meningitis is a recurrent benign non cancerous aseptic meningitis it is now referred to as benign recurrent lymphocytic meningitis it was named for pierre mollaret the french neurologist who first described it in 1944 although chronic meningitis has been defined as irritation and inflammation of the meninges persisting for more than 4 weeks being associated with pleocytosis in the cerebrospinal fluid cerebrospinal fluid abnormalities may not be detectable for the entire time diagnosis can be elusive as helbok et al note in reality many more weeks even months pass by until the diagnosis is established in many cases the signs and symptoms of chronic meningitis not only persist for periods longer than 4 weeks they even progress with continuing deterioration i e headache neck stiffness and even low grade fever impairment of consciousness epileptic seizures neurological signs and symptoms may evolve over time
molluscum contagiosum mc sometimes called water warts is a viral infection of the skin and occasionally of the mucous membranes mc can affect any area of the skin but is most common on the trunk of the body arms groin and legs it is caused by a dna poxvirus called the molluscum contagiosum virus mcv mcv has no non human reservoir infecting primarily humans though equids can rarely be infected the virus that causes molluscum contagiosum is spread from person to person by touching the affected skin the virus may also be spread by touching a surface with the virus on it such as a towel clothing or toys risk factors include being sexually active and those who are immunodeficient four types of mcv are known mcv 1 to 4 mcv 1 is the most common and mcv 2 is seen usually in adults approximately 122 million people were affected worldwide by molluscum contagiosum as of 2010 1 8 of the population it is more common in children molluscum contagiosum is most common in children aged one to 11 years old some evidence indicates molluscum infections have been on the rise globally since 1966 but these infections are not routinely monitored because they are seldom serious and routinely disappear without treatment molluscum contagiosum is contagious until the bumps are gone some growths may remain for up to 4 years if not treated
molluscum dermatitis represents a unique form of id reaction in which patients may present with localized or widespread eczema surrounding scattered lesions of molluscum contagiosum
molybdenum cofactor deficiency is a rare human disease in which the absence of molybdenum cofactor leads to accumulation of toxic levels of sulphite and neurological damage usually this leads to death within months of birth due to the lack of active sulfite oxidase furthermore a mutational block in molybdenum cofactor biosynthesis causes absence of enzyme activity of xanthine dehydrogenase oxidase and aldehyde oxidase when caused by a mutation in the mocs 1 gene it is the type a variant it can also be caused by a mutation in the mocs 2 gene or the geph gene as of 2010 there had been approximately 132 reported cases it should not be confused with molybdenum deficiency
molybdenum deficiency refers to the clinical consequences of inadequate supplies of molybdenum in the diet the amount of molybdenum required is relatively small and molybdenum deficiency usually does not occur in natural settings however it can occur in individuals receiving parenteral nutrition
mönckeberg s arteriosclerosis or mönckeberg s sclerosis also called medial calcific sclerosis or mönckeberg medial sclerosis is a form of arteriosclerosis or vessel hardening where calcium deposits are found in the muscular middle layer of the walls of arteries the tunica media it is an example of dystrophic calcification this condition occurs as an age related degenerative process however it can occur in pseudoxanthomas elasticum and idiopathic arterial calcification of infancy as a pathological condition as well its clinical significance and etiology are not well understood and its relationship to atherosclerosis and other forms of vascular calcification are the subject of disagreement mönckeberg s arteriosclerosis is named after johann georg mönckeberg who first described it in 1903
mondini dysplasia also known as mondini malformation and mondini defect is an abnormality of the inner ear that is associated with sensorineural hearing loss this deformity was first described in 1791 by carlo mondini after examining the inner ear of a deaf boy the mondini dysplasia describes a cochlea with incomplete partitioning and a reduced number of turns an enlarged vestibular aqueduct and a dilated vestibule a normal cochlea has two and a half turns a cochlea with mondini dysplasia has one and a half turns the basal turns being normally formed with a dilated or cystic apical turn to the cochlear the hearing loss can deteriorate over time either gradually or in a step wise fashion or may be profound from birth case history hearing loss associated with mondini dysplasia may first become manifest in childhood or early adult life some children may pass newborn hearing screen to lose hearing in infancy but others present with a hearing loss at birth hearing loss is often progressive and because of the associated widened vestibular aqueduct may progress in a step wise fashion associated with minor head trauma vestibular function is also often affected while the hearing loss is sensorineural a conductive element may exist probably because of the third window effect of the widened vestibular aqueduct the mondini dysplasia can occur in cases of pendred syndrome and branchio oto renal syndrome and in other syndromes but can occur in non syndromic deafness 2
mondor s disease also known as mondor s syndrome of superficial thrombophlebitis is a rare condition which involves thrombophlebitis of the superficial veins of the breast and anterior chest wall it sometimes occurs in the arm or penis in axilla this condition is known as axillary web syndrome patients with this disease often have abrupt onset of superficial pain with possible swelling and redness of a limited area of their anterior chest wall or breast there is usually a lump present which may be somewhat linear and tender because of the possibility of the lump being from another cause patients are often referred for mammogram and or breast ultrasound mondor s disease is self limiting and generally benign a cause is often not identified but when found includes trauma surgery or inflammation such as infection there have been occasional cases of associated malignancy management is with warm compresses and pain relievers most commonly nsaids such as ibuprofen when thrombophlebitis affects the greater veins it can progress into the deep venous system and may lead to pulmonary embolism it is named after henri mondor 1885 1962 a surgeon in paris france who first described the disease in 1939
monetary inflation is a sustained increase in the money supply of a country or currency area depending on many factors especially public expectations the fundamental state and development of the economy and the transmission mechanism it is likely to result in price inflation which is usually just called inflation which is a rise in the general level of prices of goods and services there is general agreement among economists that there is a causal relationship between monetary inflation and price inflation but there is neither a common view about the exact theoretical mechanisms and relationships nor about how to accurately measure it this relationship is also constantly changing within a larger complex economic system so there is a great deal of debate on the issues involved such as how to measure the monetary base and price inflation how to measure the effect of public expectations how to judge the effect of financial innovations on the transmission mechanisms and how much factors like the velocity of money affect the relationship thus there are different views on what could be the best targets and tools in monetary policy however there is a general consensus on the importance and responsibility of central banks and monetary authorities in setting public expectations of price inflation and in trying to control it keynesian economists believe the central bank can sufficiently assess the detailed economic variables and circumstances in real time in order to control monetary policy in detail these economists favor monetary policies that attempt to even out the ups and downs of business cycles and economic shocks in a precise fashion followers of the monetarist school think that keynesian style monetary policies produce a lot of overshooting time lag errors and other unwanted effects sometimes making things even worse they doubt the central bank s capacity to analyse economic problems in real time and its ability to influence the economy with correct timing and the right monetary policy measures so monetarists advocate less intrusive and complex monetary policies like inflation targeting or a constant growth rate of money supply some followers of austrian school economics advocate either the return to free markets in money called free banking or a 100 gold standard and the abolition of central banks currently most central banks follow a monetarist or keynesian approach or more often a mix of both there is a trend of central banks towards the monetarist approach with inflation targeting
monetary overhang is a phenomenon in which people have money holdings because of a lack of ability to spend them this is a phenomenon often present with repressed inflation and was common in the soviet union the solution to this is usually a swift burst of inflation in the soviet union which was dissolved in 1990 1991 monetary overhang led to hyperinflation the international monetary fund subsidised the currency to stabilise it but russia chose to end that arrangement in 1998
money disorders are the maladaptive patterns of financial beliefs and behaviors that lead to clinically significant distress impairment in social or occupational functioning due to financial strain or an inability to appropriately enjoy one ’ s financial resources with the exception of pathological gambling and compulsive buying psychology and the mental health fields have largely neglected dysfunctional money disorders types of behaviors or “ scripts ” related to money disorders include money avoidance money worship money status and money vigilance those afflicted with money disorders or who have problematic money beliefs can seek financial therapy with financial therapy financial planners and relationship therapists work together to provide comprehensive treatment to clients experiencing financial distress
in economics the money supply or money stock is the total amount of monetary assets available in an economy at a specific time there are several ways to define money but standard measures usually include currency in circulation and demand deposits depositors easily accessed assets on the books of financial institutions money supply data are recorded and published usually by the government or the central bank of the country public and private sector analysts have long monitored changes in money supply because of the belief that it affects the price level inflation the exchange rate and the business cycle that relation between money and prices is historically associated with the quantity theory of money there is strong empirical evidence of a direct relation between money supply growth and long term price inflation at least for rapid increases in the amount of money in the economy for example a country such as zimbabwe which saw extremely rapid increases in its money supply also saw extremely rapid increases in prices hyperinflation this is one reason for the reliance on monetary policy as a means of controlling inflation the nature of this causal chain is the subject of contention some heterodox economists argue that the money supply is endogenous determined by the workings of the economy not by the central bank and that the sources of inflation must be found in the distributional structure of the economy in addition those economists seeing the central bank s control over the money supply as feeble say that there are two weak links between the growth of the money supply and the inflation rate first in the aftermath of a recession when many resources are underutilized an increase in the money supply can cause a sustained increase in real production instead of inflation second if the velocity of money i e the ratio between nominal gdp and money supply changes an increase in the money supply could have either no effect an exaggerated effect or an unpredictable effect on the growth of nominal gdp
the moneymaker effect is the name of the sudden growth in interest in poker after the 2003 world series of poker main event
a mongolian spot also known as mongolian blue spot congenital dermal melanocytosis and dermal melanocytosis is a benign flat congenital birthmark with wavy borders and irregular shape in 1883 it was described and named after mongolians by erwin bälz a german anthropologist based in japan it normally disappears three to five years after birth and almost always by puberty the most common color is blue although they can be blue gray blue black or deep brown
monilethrix also referred to as beaded hair is a rare autosomal dominant hair disease that results in short fragile broken hair that appears beaded it comes from the latin word for necklace monile and the greek word for hair thrix
monilinia oxycocci woronin honey synonym sclerotinia oxycocci common names cranberry cottonball cranberry hard rot tip blight is a fungal infection of the cranberry plant vaccinium macrocarpon the tips of young flowering shoots wilt before they flower fruit that does form on the plant can then be infected by the asexual spores traveling through the plant causing the berries to harden turn cottony on the inside and dry out instead of maturing the berries are filled with a cotton like fungus and are generally yellowish with tan stripes or blotches at maturity making them unmarketable it results in important economic impacts on many cranberry marshes particularly in wisconsin
the monkey and banana problem is a famous toy problem in artificial intelligence particularly in logic programming and planning
the monkey tree phenomenon is a social phenomenon in singapore which began in september 2007 it arose from the discovery of a callus on a tree in hong kah which appears monkey like some believe the image to be of divine origin while others have attributed the phenomenon to the effects of pareidolia whereby random stimuli are perceived as meaningful the callus has initiated a minor social mania drawing large crowds to look or pray at the tree
monkeypox is an infectious disease caused by the monkeypox virus the disease was first identified in laboratory monkeys hence its name but in its natural state it seems to infect rodents more often than primates the disease is indigenous to central and west africa an outbreak that occurred in the united states in 2003 was traced to a pet store where imported gambian pouched rats were sold monkeypox virus is a zoonotic viral disease that occurs primarily in remote villages of central and west africa in proximity to tropical rainforests where there is more frequent contact with infected animals monkeypox is usually transmitted to humans from rodents pets and primates through contact with the animal s blood or through a bite human monkeypox can be difficult to distinguish clinically from smallpox to which it is closely related and chickenpox to which it is not
the autosomal dominant syndrome associated with monocytopenia b and nk cell lymphopenia and mycobacterial fungal and viral infections abbreviated monomac is a rare genetic disorder first described by vihn and colleagues in 2010 and is associated with myelodysplasia cytogenetic abnormalities pulmonary alveolar proteinosis and myeloid leukemias multiple mutations in the gata 2 are considered to be responsible for this syndrome
monoarthritis is inflammation arthritis of one joint at a time it is usually caused by trauma infection or crystalline arthritis
monochromacy mono meaning one and chromo color is among organisms or machine the ability to distinguish only one single frequency of the electromagnetic light spectrum in the physical sense no source of electromagnetic radiation is purely monochromatic but can be considered as a gaussian distribution of frequencies shaped around a peak in the same way a visual system of an organism or a machine cannot be monochromat but will distinguish a continuous set of frequencies around a peak depending by the intensity of the light organisms with monochromacy are called monochromats many species such as all marine mammals the owl monkey and the australian sea lion pictured at right are monochromats under normal conditions in humans absence of color discrimination or poor color discrimination is one among several other symptoms of severe inherited or acquired diseases as for example inherited achromatopsia omim 216900 262300 139340 613093 acquired achromatopsia or inherited blue cone monochromacy omim 303700
in graph theory and theoretical computer science the monochromatic triangle problem is an algorithmic problem on graphs in which the goal is to partition the edges of a given graph into two triangle free subgraphs it is np complete but fixed parameter tractable on graphs of bounded treewidth
a monochrome or red rainbow is an optical and meteorological phenomenon and a rare variation of the more commonly seen multicolored rainbow its formation process is identical to that of a normal rainbow namely the reflection refraction of light in water droplets the difference being that a monochrome rainbow requires the sun to be close to the horizon i e near sunrise or sunset the low angle of the sun results in a longer distance for its light to travel through the atmosphere causing shorter wavelengths of light such as blue green and yellow to be scattered and leaving primarily red in the lower light environment where the phenomenon most often forms a monochrome rainbow can leave a highly dramatic effect
monoclonal b cell lymphocytosis mbl is a condition that resembles chronic lymphocytic leukemia cll but does not meet the criteria for cll and does not require treatment however cll requiring treatment develops at the rate of 1 1 per year the definition of cll includes 5 000 cll phenotype b cell lymphocytes per cubic millimeter patients with 5 000 but not 0 cll phenotype b cell lymphocytes per mm ³ and no symptoms of cll are diagnosed with mbl the term monoclonal means that all the b cells are derived from a single cell
monoclonal gammopathy of undetermined significance mgus unknown or uncertain may be substituted for undetermined formerly benign monoclonal gammopathy is a condition in which a paraprotein is found in the blood during standard laboratory blood tests it resembles multiple myeloma and similar diseases but the levels of antibody are lower the number of plasma cells white blood cells that secrete antibodies in the bone marrow is lower it has no symptoms or major problems although patients with mgus have sometimes been reported to suffer from peripheral neuropathy and no treatment is indicated however multiple myeloma develops at the rate of about 1 5 a year so doctors recommend monitoring it yearly the progression from mgus to multiple myeloma usually involves several steps in rare cases it may also be related with a slowly progressive symmetric distal sensorimotor neuropathy
monocular rivalry is a phenomenon of human visual perception that occurs when two different images are optically superimposed during prolonged viewing one image becomes clearer than the other for a few moments then the other image becomes clearer than the first for a few moments these alternations in clarity continue at random for as long as one looks occasionally one image will become exclusively visible and the other image invisible in the demonstration one image is a green grating and the other is a red grating during prolonged inspection the viewer can see the green grating as clearer than the red grating for a few moments then the reverse occasionally the green grating will be all that is visible and occasionally the red grating will be all that is visible occasionally at transitions one will briefly see irregular composites of the two gratings such as the red and green gratings superimposed but with one or two bars of the green grating invisible
monocytic leukemia is a type of myeloid leukemia characterized by a dominance of monocytes in the marrow when the monocytic cells are predominantly monoblasts it can be subclassified into acute monoblastic leukemia monocytic leukemia is almost always broken down into acute and chronic acute monocytic leukemia chronic myelomonocytic leukemia
monocytopenia is a form of leukopenia associated with a deficiency of monocytes the causes of monocytopenia include acute infections stress treatment with glucocorticoids aplastic anemia hairy cell leukemia acute myeloid leukemia treatment with myelotoxic drugs and genetic syndromes as for example monomac syndrome it has been proposed as a measure to predict neutropenia though some research indicates that it is less effective than lymphopenia
monocytosis is an increase in the number of monocytes circulating in the blood monocytes are white blood cells that give rise to macrophages and dendritic cells in the immune system in humans 950 μl is regarded as at the upper limit of normal monocyte counts above this level are regarded as monocytosis monocytosis has sometimes been called mononucleosis but that name is usually reserved specifically for infectious mononucleosis
monodominance is an ecological condition in which more than 60 of the tree canopy comprises a single species of tree although monodominance is studied across different regions most research focuses on the many prominent species in tropical forests connel and lowman originally called it single dominance conventional explanations of biodiversity in tropical forests in the decades prior to connel and lowman s work either ignored monodominance entirely or predicted that it would not exist connel and lowman hypothesized two contrasting mechanisms by which dominance can be attained the first is by fast regrowth in unstable habitats with high disturbance rates the second is through competitive exclusion in stable habitats that have low disturbance rates explanations of persistent monodominace include the monodominant species being more resistant than others to seasonal flooding or that the monodominance is simply a sere with persistent monodominance the monodominant species successfully remains so from generation to generation
monofixation syndrome mfs also microtropia or microstrabismus is an eye condition defined by less than perfect binocular vision it is defined by a small angle deviation with suppression of the deviated eye and the presence of binocular peripheral fusion that is mfs implies peripheral fusion without central fusion aside the manifest small angle deviation tropia subjects with mfs often also have a large angle latent deviation phoria their stereoacuity is often in the range of 3000 to 70 arcsecond and a small central suppression scotoma of 2 to 5 deg a rare condition mfs is estimated to affect only 1 of the general population there are three distinguishable forms of this condition primary constant primary decompensating and consecutive mfs it is believed that primary mfs is a result of a primary sensorial defect predisposing to anomalous retinal correspondence secondary mfs is a frequent outcome of surgical treatment of congenital esotropia a study of 1981 showed mfs to result in the vast majority of cases if surgical alignment is reached before the age of 24 months and only in a minority of cases if it is reached later mfs was first described by marshall parks
monoglottism greek μόνοσ monos alone solitary γλώττα glotta tongue language or more commonly monolingualism or unilingualism is the condition of being able to speak only a single language as opposed to multilingualism in a different context unilingualism may refer to a language policy which enforces an official or national language over others being monolingual or unilingual is also said of a text dictionary or conversation written or conducted in only one language and of an entity in which a single language is either used or officially recognized in particular when being compared with bilingual or multilingual entities or in the presence of individuals speaking different languages note that monoglottism can only refer to lacking the ability to speak several languages multilingual speakers outnumber monolingual speakers in the world s population romaine 1995 pointed out in her book bilingualism that it would be weird to find a book titled monolingualism this statement reflects the traditional assumption that linguistic theories often take on that monolingualism is the norm monolingualism is thus rarely the subject of scholarly publications as it is viewed to be an unmarked or prototypical concept where it has the sense of being normal and multilingualism is the exception the assumption of normative monolingualism is also often the view of monolinguals who speak a global language like the english language crystal 1987 said that this assumption is adopted by many in western society one explanation is provided by edwards who in 2004 claimed that evidence of the monolingual mindset can be traced back to 19 th century europe when the nation was rising and a dominant group had control and european mindsets on language were carried forth to its colonies further perpetuating the monolingual mindset another explanation is that the nations who speak the english language are both “ the producers and beneficiaries of english as a global language ” and the populations within these countries tend to be monolingual
in 19 th century psychiatry monomania from greek monos one and mania meaning madness or frenzy was a form of partial insanity conceived as single pathological preoccupation in an otherwise sound mind partial insanity variations of which enjoyed a long pre history in jurisprudence was in contrast to the traditional notion of total insanity exemplified in the diagnosis of mania as a global condition affecting all aspects of understanding and which reflected the position that the mind or soul was an indivisible entity coined by the french psychiatrist jean étienne dominique esquirol 1772 – 1840 around 1810 monomania was a new disease concept characterised by the presence of an expansive idée fixe in which the mind was diseased and deranged in some facets but otherwise normal in others esquirol and his circle delineated three broad categories of monomania coherent with the traditional tripartite classification of the mind into intellectual emotional and volitional faculties emotional monomania is that in which the patient is obsessed with only one emotion or several related to it intellectual monomania is that which is related to only one kind of delirious idea or ideas although monomania was retained as one of seven recognized categories of mental illness in the 1880 us census its importance as a psychiatric diagnostic category was in decline from the mid 19 th century
monomelic amyotrophy mma also known as hirayama disease sobue disease juvenile non progressive amyotrophy and juvenile asymmetric segmental spinal muscular atrophy jassma — is an untreatable focal motor neuron disease that primarily affects young 15 to 25 year old males in india and japan mma is marked by insidious onset of muscular atrophy which stabilizes at a plateau after two to five years from which it neither improves nor worsens there is no pain or sensory loss associated with mma unlike other lower motor neuron diseases mma is not believed to be hereditary and fasciculations involuntary muscle twitches are rare emg tests reveal loss of the nerve supply or denervation in the affected limb without conduction block nerve blockage restricted to a small segment of the nerve increased sweating coldness and cyanosis have been reported for a few patients indicating involvement of the sympathetic nervous system while mma will cause weakness and or wasting in only one limb emg and ncv tests often show signs of reinnervation in the unaffected limbs
the monongahela culture were a native american cultural manifestation of late woodland peoples from ad 1050 to 1635 in present day western pennsylvania western maryland eastern ohio and west virginia the culture was named by mary butler in 1939 for the monongahela river whose valley contains the majority of this culture s sites the monongahela practiced maize agriculture and lived in well laid out villages some of which consisted of as many as 50 100 structures they traded with other indian groups who in turn traded with europeans the monongahela seem to have disappeared some time during the 1620 s or 1630 s before having significant direct contact with europeans many scholars believe this to be the result of the spread of european infectious diseases others believe that most of the monongahela were killed by or assimilated into either the iroquois or the algonquian speaking lenape tribes during warfare as the more powerful tribes competed to control area hunting grounds for the fur trade still others claim that two severe droughts one from 1587 – 1589 and another from 1607 – 1612 drove the monongahela from the region in search of a more habitable area
in medicine monoplegia is a paralysis of a single limb usually an arm it is frequently associated with cerebral palsy this is the mildest form of cerebral palsy and individuals with it generally have a good prognosis for later life it can also be used if just one muscle group or muscle is affected it is often thought as hemiplegia with much less involvement of the other limb monoplegia is often a result to damage to the brain or spinal cord that manage motor functions of the affected limb ransansky 2013 the hands and feet are often affected causing curling of the hands and stiffness of the feet other symptoms include weakness numbness paralysis pain in the affected limb other symptoms include headaches and shoulder pain monoplagia 2016 though cerebral palsy is the main cause other causes include a brain tumor stroke nerve trauma nerve inflammation multiple sclerosis brown sequard syndrome mono neuritis multiplex monoplagia 2015 treatments of monoplegia typically includes physical therapy and counseling to help recovery muscle tone and function however there is no cure for monoplegia ransansky 2013 recovery will vary depending on diagnosis from temporary partial or complete paralysis monoplagia 2015 a similar condition is monoparesis in which one limb is very weak but not completely paralyzed for more information see paresis a person with monoplegia can be referred to as a monoplegic monoplegia of the upper limb is sometimes referred to as brachial monoplegia while that of the lower limb is called crural monoplegia the two leading causes to monoplegia are brachial plexopathy and stroke the chance of a brachial plexopathy proceeding after a noncardiac surgery is between 0 02 and 0 06 perioperative strokes occur at a higher rate of 0 08 to 9 7 patients of monoplegia usually feel symptoms of weakness and loss of sensation in an extremity usually an arm the extremity with paralysis continues to maintain a strong pulse one study found that immediate initiation of a heparin infusion may have helped in the recovery of feeling in the extremity monoplegia in the lower extremities is not as common as occurrence as in the arms this can be caused by brown sequard syndrome and hematomas in the fronto parital cortex near the middle that could produce a deficit such as this is a very uncommon occurrence
monorchism also monorchidism is the state of having only one testicle within the scrotum
monosemy is the absence of semantic ambiguity in language i e only having one meaning per word the majority of natural human languages are polysemous i e having more than one meaning per word the artificial language lojban and its predecessor loglan represent attempts at creating monosemous languages monosemy is important for translation and semantic computing
monosomy 9 p also known as alfi s syndrome or simply 9 p is a rare chromosomal disorder in which there is deletion monosomy of a portion of chromosome 9 symptoms include microgenitalia mental retardation with microcephaly and dysmorphic features the location has recently been narrowed to 9 p 22 2 p 23
monostotic fibrous dysplasia or monostotic osteitis fibrosa is a form of fibrous dysplasia where only one bone is involved it comprises a majority of the cases of fibrous dysplasia it is also known as jaffe lichtenstein syndrome a rare bone disorder characterized by benign bone growths which can cause very painful swellings and bone deformities and makes bone prone to fractures
in mathematics a monotonic function or monotone function is a function between ordered sets that preserves or reverses the given order this concept first arose in calculus and was later generalized to the more abstract setting of order theory
a monstrous birth variously defined in history is a birth in which a defect of some sort renders the animal or human child monstrous such births were often taken as omens signs of god or moral warnings but besides these supernatural or religious explanations medical explanations were also given in which often the mother s state of mind or her sexual behavior was responsible for the deformed fetus in early and medieval christianity monstrous births posed difficult theological problems about humanity and salvation in the early modern period the interest shifted toward scientific inquiry
the monteggia fracture is a fracture of the proximal third of the ulna with dislocation of the head of the radius it is named after giovanni battista monteggia
mood disorder is a group of diagnoses in the diagnostic and statistical manual of mental disorders dsm classification system where a disturbance in the person s mood is hypothesized to be the main underlying feature the classification is known as mood affective disorders in international classification of diseases icd english psychiatrist henry maudsley proposed an overarching category of affective disorder the term was then replaced by mood disorder as the latter term refers to the underlying or longitudinal emotional state whereas the former refers to the external expression observed by others mood disorders fall into the basic groups of elevated mood such as mania or hypomania depressed mood of which the best known and most researched is major depressive disorder mdd commonly called clinical depression unipolar depression or major depression and moods which cycle between mania and depression known as bipolar disorder bd formerly known as manic depression there are several sub types of depressive disorders or psychiatric syndromes featuring less severe symptoms such as dysthymic disorder similar to but milder than mdd and cyclothymic disorder similar to but milder than bd mood disorders may also be substance induced or occur in response to a medical condition
moon facies or moon face is a medical sign in which the face develops a rounded appearance due to fat deposits on the sides of the face it is often associated with cushing s syndrome or steroid treatment especially corticosteroids which has led to it being known as cushingoid facies cushings like face
a mooncalf or moon calf is the abortive fetus of a cow or other farm animal the term was occasionally applied to an abortive human fetus the term derives from the formerly widespread superstition present in many european folk traditions that such malformed creatures were the product of the sinister influence of the moon on fetal development
moose sickness is a degenerative condition that occurs in moose populations in central and eastern north america that have been infected with the parasitic worm parelaphostrongylus tenuis the disease is characterized by stumbling aimlessness and other odd behavior and is often fatal the parasite is carried by white tailed deer who are otherwise unaffected by it the worm s life cycle is complex to get the disease a moose has to eat vegetation inhabited by snails or slugs that have come in contact with infected deer feces
moral agency is an individual s ability to make moral judgments based on some notion of right and wrong and to be held accountable for these actions a moral agent is a being who is capable of acting with reference to right and wrong
moral breakdown is a phenomenon in which a major degradation or complete loss of moral values takes place within a particular society the abruptness of such kind of degradation may vary depending on the situation and the events that take place within the given society over a certain time moral breakdown may be caused by the changes in the political and or cultural changes of the society conflict or a natural disaster
in insurance analysis morale hazard is an increase in the hazards presented by a risk arising from the indifference of the person insured to loss because of the existence of insurance insurance analysts distinguish this from moral hazard the use of the term in this way dates back to at least 1968 when it was used in the fourth edition of casualty insurance this usage differs from that in economic theory see contract theory in economics whenever insurance of a risk causes decision makers to act in a way that increases the risk called moral hazard regardless of whether the change in behavior is conscious or malicious
morbid jealousy also known as othello syndrome or delusional jealousy is a psychological disorder in which a person is preoccupied with the thought that their spouse or sexual partner is being unfaithful without having any real proof along with socially unacceptable or abnormal behaviour related to these thoughts the most common cited forms of psychopathology in morbid jealousy are delusions and obsessions it is considered a subtype of delusional disorder some symptoms of pathological jealousy include accusing partner of looking or giving attention to other people questioning of the partner s behavior interrogation of phone calls including wrong numbers or accidental phone calls and all other forms of communication not allowing any social media accounts facebook twitter etc going through the partner ’ s belongings always asking where the partner is and who they are with isolating partner from their family and friends not letting the partner have personal interests or hobbies outside the house controlling the partner s social circle claiming the partner is having an affair when they withdraw or tries to escape abuse accusing the partner of holding affairs when the marriage s sexual activity stops because of the abuse verbal and or physical violence towards the partner the individual whom is considered to be the rival or both blaming the partner and establishing an excuse for jealous behavior denying the jealous behavior unless cornered threatening to harm others or themselves overvaluing an idea which is defined as “ an acceptable comprehensible idea pursued by the patient beyond the bounds of reason the idea is not resisted and although it is not a delusion the patient characteristically attaches utmost importance to investigating and maintaining the partner ’ s fidelity at great personal disadvantage and to the distress of the partner ” overvalued ideas are characterized by being existent in the individual ’ s own thoughts being egosyntonic meaning that the ideas project the behaviors values and feelings that are aligned with the desires and aims of the individual ’ s ego or consistent with the individual ’ s ideal self image the ideas are also amenable to reason but are not resisted ix
morel s ear is the complete or partial absence of the helix or antihelix of the outer ear named after bénédict morel a french psychiatrist who regarded it as one of the hereditary stigmata of degeneration that allowed medical professions to identify the mentally ill marcel proust referenced morel s ear in in search of lost time when charles morel says he would like to seduce a virgin his companion responds first of all with a gesture m de charlus could not refrain from pinching morel s ear
morgagni stewart morel syndrome metabolic craniopathy is a condition with a wide range of associated endocrine problems including diabetes mellitus diabetes insipidus and hyperparathyroidism other signs and symptoms include headaches vertigo hirsutism menstrual problems galactorrhoea obesity depression and seizures thickening of the inner table of the frontal part of the skull a usually benign condition known as hyperostosis frontalis interna the syndrome was first described in the year 1765
morgellons mɔː ɹ ˈdʒɛlənz is the informal name of a self diagnosed skin condition in which individuals have sores that they believe contain some kind of fibers it is now known to be a form of delusional parasitosis the sores are the result of compulsive scratching and the fibers when analysed turn out to originate from textiles the name was coined in 2002 by mary leitao a mother who rejected the medical diagnosis of her son s delusional parasitosis she revived it from a letter written by a physician in the mid 1600 s leitao and others involved in her morgellons research foundation successfully lobbied members of the u s congress and the u s centers for disease control and prevention cdc to investigate the condition in 2006 cdc researchers issued the results of their multi year study in january 2012 indicating that there were no disease organisms present in people with morgellons and that the fibers found were likely cotton and concluded that the condition was similar to more commonly recognized conditions such as delusional infestation
the morita conjectures in general topology are certain problems about normal spaces now solved in the affirmative they asked 1 if x × y is normal for every normal space y is x discrete 2 if x × y is normal for every normal p space y is x metrizable 3 if x × y is normal for every normal countably paracompact space y is x metrizable and sigma locally compact the answers were believed to be affirmative here a normal p space y is characterised by the property that the product with every metrizable x is normal thus the conjecture was that the converse holds k chiba t c przymusiński and m e rudin proved conjecture 1 and showed that conjectures 2 and 3 cannot be proven false under the standard zfc axioms for mathematics specifically that the conjectures hold under the axiom of constructibility v l fifteen years later z balogh succeeded in proving conjectures 2 and 3 true
in the dungeons dragons fantasy role playing game the morkoth pronounced more koth is an aberration
the morning glory cloud is a rare meteorological phenomenon consisting of a low level atmospheric solitary wave and associated cloud occasionally observed in different locations around the world the wave often occurs as an amplitude ordered series of waves forming bands of roll clouds the southern part of the gulf of carpentaria in northern australia is the only known location where it can be predicted and observed on a more or less regular basis due to the configuration of land and sea in the area
the morning glory disc anomaly mgda is a congenital deformity resulting from failure of the optic nerve to completely form in utero the term was coined in 1970 by kindler noting a resemblance of the malformed optic nerve to the morning glory flower the condition is usually unilateral on fundoscopic examination there are three principal findings comprising the anomaly 1 an enlarged funnel shaped excavation in optic disc 2 an annulus or ring of chorioretinal pigmentary changes surrounding the optic disc excavation 3 a central glial tuft overlying the optic disc
morning sickness also called nausea and vomiting of pregnancy nvp is a symptom of pregnancy that involves nausea or vomiting despite the name nausea or vomiting can occur at any time during the day typically these symptoms occur between the 4 th and 16 th week of pregnancy about 10 of women still have symptoms after the 20 th week of pregnancy a severe form of the condition is known as hyperemesis gravidarum and results in weight loss the cause of morning sickness is unknown but may be related to changing levels of the hormone human chorionic gonadotrophin some have proposed that it may be useful from an evolutionary point of view diagnosis should only occur after other possible causes have been ruled out abdominal pain fever or headaches are typically not present in morning sickness taking prenatal vitamins before pregnancy may decrease the risk specific treatment other than a bland diet may not be required for mild cases if treatment is used the combination of doxylamine and pyridoxine is recommended initially tentative evidence supports the use of ginger for severe cases that have not improved with other measures methylprednisolone may be tried tube feeding may be required in women who are losing weight morning sickness affects about 80 of all pregnant women to some extent about 60 of women have vomiting hyperemesis gravidarum occurs in about 1 6 of pregnancies morning sickness can negatively affect quality of life result in decreased ability to work while pregnant and result in health care expenses generally mild to moderate cases have no effect on the baby most severe cases also have normal outcomes some women choose to have an abortion due to the severity of symptoms complications such as wernicke encephalopathy or esophageal rupture may occur but are very rare
the morning star is a pattern seen in a candlestick chart a type of chart used by stock analysts to describe and predict price movements of a security derivative or currency over time
morphea also known as localized scleroderma or circumscribed scleroderma involves isolated patches of hardened skin with no internal organ involvement
morphing is a special effect in motion pictures and animations that changes or morphs one image or shape into another through a seamless transition most often it is used to depict one person turning into another through technological means or as part of a fantasy or surreal sequence traditionally such a depiction would be achieved through cross fading techniques on film since the early 1990 s this has been replaced by computer software to create more realistic transitions
in algebraic geometry a morphism between algebraic varieties is a function between the varieties that is given locally by polynomials it is also called a regular map a morphism from an algebraic variety to the affine line is also called a regular function a regular map whose inverse is also regular is called biregular and they are isomorphisms in the category of algebraic varieties because regular and biregular are very restrictive conditions – there are no non constant regular functions on projective varieties – the weaker condition of a rational map and birational maps are frequently used as well
in mathematical morphology and digital image processing a morphological gradient is the difference between the dilation and the erosion of a given image it is an image where each pixel value typically non negative indicates the contrast intensity in the close neighborhood of that pixel it is useful for edge detection and segmentation applications
morquio syndrome referred to as mucopolysaccharidosis iv mps iv morquio brailsford syndrome or morquio is an autosomal recessive mucopolysaccharide storage disease see also lysosomal storage disorder usually inherited it is a rare type of birth defect with serious consequences in the us the incidence rate for morquio is estimated at between 1 in 200 000 and 1 in 300 000 live births when the body cannot process certain types of mucopolysaccharides they build up or are eliminated causing various symptoms these involve accumulation of keratan sulfate
morsicatio buccarum also termed chronic cheek biting and chronic cheek chewing is a condition characterized by chronic irritation or injury to the buccal mucosa the lining of the inside of the cheek within the mouth caused by repetitive chewing biting or nibbling
in computability theory the mortality problem is a decision problem which can be stated as follows given a turing machine decide whether it halts when run on any configuration not necessarily a starting one in the statement above the configuration is a pair q w where q is one of the machine s states not necessarily its initial state and w is an infinite sequence of symbols representing the initial content of the tape note that while we usually assume that in the starting configuration all but finitely many cells on the tape are blanks in the mortality problem the tape can have arbitrary content including infinitely many non blank symbols written on it philip k hooper proved in 1966 that the mortality problem is undecidable however it can be shown that the set of turing machines which are mortal i e halt on every starting configuration is recursively enumerable
mortimer s disease is a skin disease characterized by red blotchy patterns appearing all over the face and hands and spreading through the body in an almost symmetrical pattern the fact that there are no ulcers and an absence of crust indicate that this is a different entity than lupus vulgaris the disease was originally documented by jonathan hutchinson 1828 1913 and became an eponym after his patient mrs mortimer
morton s neuroma also known as morton neuroma morton s metatarsalgia intermetatarsal neuroma and intermetatarsal space neuroma is a benign neuroma of an intermetatarsal plantar nerve most commonly of the second and third intermetatarsal spaces between 2 nd − 3 rd and 3 rd − 4 th metatarsal heads which results in the entrapment of the affected nerve the main symptoms are pain and or numbness sometimes relieved by removing footwear some sources claim that entrapment of the plantar nerve because of compression between the metatarsal heads as originally proposed by morton is highly unlikely because the plantar nerve is on the plantar side of the transverse metatarsal ligament and thus does not come in contact with the metatarsal heads it is more likely that the transverse metatarsal ligament is the cause of the entrapment despite the name the condition was first correctly described by a chiropodist named durlacher and although it is labeled a neuroma many sources do not consider it a true tumor but rather a perineural fibroma fibrous tissue formation around nerve tissue
morton s toe or morton s foot greek foot royal toe turkey toe lamay toe hallicusbradymetatarsalgia sheppard s toe morton s syndrome long toe boss toe is the condition of a shortened first metatarsal in relation to the second metatarsal it is a type of brachymetatarsia the metatarsal bones behind the toes vary in relative length for most feet a smooth curve can be traced through the joints at the bases of the toes but in morton s foot the line has to bend more sharply to go through the base of the big toe as shown in the diagram this is because the first metatarsal behind the big toe is short compared to the second metatarsal next to it the longer second metatarsal puts the joint at the base of the second toe the second metatarsal phalangeal or mtp joint farther forward if the big toe and the second toe are the same length as measured from the mpt joint to the tip including only the phalanges then the second toe will protrude farther than the big toe as shown in the photo if the second toe is shorter than the big toe the big toe may still protrude the farthest or there may be little difference as shown in the x ray
morvan s syndrome or morvan s fibrillary chorea mfc is a rare autoimmune disease named after the nineteenth century french physician augustin marie morvan la chorée fibrillaire was first coined by morvan in 1890 when describing patients with multiple irregular contractions of the long muscles cramping weakness pruritus hyperhidrosis insomnia and delirium it normally presents with a slow insidious onset over months to years approximately 90 of cases spontaneously go into remission while the other 10 of cases lead to death
in genetics a mosaic or mosaicism describes the presence of two or more populations of cells with different genotypes in one individual who has developed from a single fertilized egg 1 mosaicism has been reported to be present in as high as 70 of cleavage stage embryos and 90 of blastocyst stage embryos derived from in vitro fertilization 2 genetic mosaicism can result from many different mechanisms including chromosome non disjunction anaphase lag and endoreplication 2 anaphase lagging is the most common way by which mosaicism arises in the preimplantation embryo 2 mosaicism can also result from a mutation in one cell during development in which the mutation is passed on to only its daughter cells therefore the mutation is only going to be present in a fraction of the adult cells 1 genetic mosaics may often be confused with chimerism in which two or more genotypes arise in one individual similarly to mosaicism however the two genotypes arise from the fusion of more than one fertilized zygote in the early stages of embryonic development rather than from a mutation
the moscow theater hostage crisis also known as the 2002 nord ost siege was the seizure of a crowded dubrovka theater by 40 to 50 armed chechens on 23 october 2002 that involved 850 hostages and ended with the death of at least 170 people the attackers led by movsar barayev claimed allegiance to the islamist militant separatist movement in chechnya they demanded the withdrawal of russian forces from chechnya and an end to the second chechen war due to the disposition of the theater special forces would have had to fight through 30 metres 98 ft of corridor and attack up a well defended staircase before they could reach the hall in which the hostages were held the attackers had numerous explosives with the most powerful in the center of the auditorium after the murder of two female hostages two and a half days in spetsnaz operators from federal security service fsb alpha and vega groups supported by a russian ministry of internal affairs mvd sobr unit pumped an undisclosed chemical agent into the building s ventilation system and began the rescue operation all 40 of the attackers were killed with no casualties among spetsnaz about 130 hostages died including nine foreigners due to adverse reactions to the gas all but two of the hostages who died during the siege were killed by the toxic substance pumped into the theater to subdue the militants the use of the gas was widely condemned as heavy handed but the american and british governments deemed russia s actions justifiable physicians in moscow condemned the refusal to disclose the identity of the gas that prevented them from saving more lives some reports said the drug naloxone was successfully used to save some hostages suggesting the gas was an opiate based compound
moser s worm problem is an unsolved problem in geometry formulated by the austrian canadian mathematician leo moser in 1966 the problem asks for the region of smallest area that can accommodate every plane curve of length 1 here accommodate means that the curve may be rotated and translated to fit inside the region in some variations of the problem the region is restricted to be convex
mosquito borne diseases or mosquito borne illnesses are diseases caused by bacterial viruses or parasites transmitted by mosquitoes they can transmit disease without being affected themselves diseases transmitted by mosquitoes include malaria dengue west nile virus chikungunya yellow fever filariasis japanese encephalitis saint louis encephalitis western equine encephalitis eastern equine encephalitis venezuelan equine encephalitis la crosse encephalitis and zika fever nearly 700 million people get a mosquito borne illness each year resulting in greater than one million deaths
in biology mother s curse is an evolutionary effect that males inherit deleterious mitochondrial genome mtdna mutations from their mother while those mutations are beneficial neutral or less deleterious to females as mtdna is usually maternally inherited mtdna mutations deleterious to males but beneficial neutral or less deleterious to females are not subjected to be selected against which results in a sex biased selective sieve therefore male specific deleterious mtdna mutations could be maintained and reach a high frequency in populations decreasing males fitness and population viability in addition the effect of mtdna mutations on fitness has a threshold effect i e only when the number of mutation reaches the threshold mtdna mutations will decrease individual fitness males are more susceptible to mtdna defects not only because of lack of selection for mtdna on males but also due to sperm ’ s higher energy requirements for motility there are evidence showing mtdna mutations are more likely to affect males in humans leber s hereditary optic neuropathy lhon is caused by one or several point mutations on mtdna and lhon affects more males than females in mice a deletion on mtdna causes oligospermia and asthenozoospermia resulting in infertility taken together mtdna mutations pose a greater threat on males than on females
in biology motility is the ability to move spontaneously and actively consuming energy in the process motility is genetically determined see genetic determinism but may be affected by environmental factors for instance muscles give animals motility but the consumption of hydrogen cyanide the environmental factor in this case would adversely affect muscle physiology causing them to stiffen leading to rigor mortis most animals are motile but the term applies to unicellular and simple multicellular organisms as well as to some mechanisms of fluid flow in multicellular organs in addition to animal locomotion motile marine animals are commonly called free swimming motility may also refer to an organism s ability to move food through its digestive tract i e peristaltics gut motility intestinal motility etc
motion induced blindness mib is a phenomenon of visual disappearance or perceptual illusions observed in the lab in which stationary visual stimuli disappear as if erased in front of an observer s eyes when masked with a moving background most recent research has shown that microsaccades counteract disappearance but are neither necessary nor sufficient to account for mib
motion induced interocular suppression is a phenomenon in which when one eye is presented with a constantly moving visual pattern while the other eye is shown a stationary image the stationary image is suppressed from awareness for long periods of time the duration of this motion induced interocular suppression is comparable to that of continuous flash suppression thus the two methods can be used alternatively the duration of suppression in both methods is maximized if the image being suppressed has low luminance contrast or a low spatial frequency spectrum motion induced interocular suppression is fundamentally different from motion induced blindness firstly the latter is due to the interaction of moving and stationary stimuli closely located within the same eye while the former requires an interaction between stimuli presented to different eyes in corresponding visual areas secondly motion induced interocular suppression can induce invisibility of a large stimulus presented at the fovea whereas motion induced blindness requires the stimulus to be small and peripherally located thirdly decreasing the contrast of the stimulus to be suppressed increases the duration of motion induced interocular suppression but decreases the duration of motion induced blindness whether motion induced interocular suppression and continuous flash suppression have common neural mechanisms is still unknown
motion sickness also known as kinetosis and travel sickness is a condition in which a disagreement exists between visually perceived movement and the vestibular system s sense of movement depending on the cause it can also be referred to as seasickness car sickness simulation sickness or airsickness dizziness fatigue and nausea are the most common symptoms of motion sickness sopite syndrome in which a person feels fatigue or tiredness is also associated with motion sickness nausea in greek means seasickness naus means ship if the motion causing nausea is not resolved the sufferer will usually vomit vomiting often will not relieve the feeling of weakness and nausea which means the person might continue to vomit until the cause of the nausea is treated
in physics and chemistry motional narrowing is a phenomenon where a certain resonant frequency has a smaller linewidth than might be expected due to motion in an inhomogeneous system
motivated reasoning is an emotion biased decision making phenomenon studied in cognitive science and social psychology this term describes the role of motivation in cognitive processes such as decision making and attitude change in a number of paradigms including cognitive dissonance reduction beliefs about others on whom one s own outcomes depend evaluation of evidence related to one s own outcomes
motivational deficiency disorder is the name of a fake disease imagined for a health campaign to raise awareness of disease mongering
a motive in law especially criminal law is the cause that moves people to induce a certain action motive in itself is not an element of any given crime however the legal system typically allows motive to be proven in order to make plausible the accused s reasons for committing a crime at least when those motives may be obscure or hard to identify with however a motive is not required to reach a verdict motives are also used in other aspects of a specific case for instance when police are initially investigating the law technically distinguishes between motive and intent intent in criminal law is synonymous with mens rea which means the mental state shows liability which is enforced by law as an element of a crime motive describes instead the reasons in the accused s background and station in life that are supposed to have induced the crime motives are often broken down into three categories biological social and personal
motor disorders are disorders of the nervous system that cause abnormal and involuntary movements they can result from damage to the motor system motor disorders are defined in the fifth edition of the diagnostic and statistical manual of mental disorders dsm 5 – published in 2013 to replace the fourth text revision dsm iv tr – as a new sub category of neurodevelopmental disorders the dsm 5 motor disorders include developmental coordination disorder stereotypic movement disorder and the tic disorders including tourette syndrome
a motor neuron disease mnd is any of several neurological disorders that selectively affect motor neurons the cells that control voluntary muscles of the body they include amyotrophic lateral sclerosis als primary lateral sclerosis pls progressive muscular atrophy pma progressive bulbar palsy pbp and pseudobulbar palsy spinal muscular atrophies are also sometimes included in the group they are neurodegenerative in nature and cause increasing disability and eventually death
motor speech disorders are a class of speech disorder that disturb the body s natural ability to speak these disturbances vary in their etiology based on the integrity and integration of cognitive neuromuscular and musculoskeletal activities speaking is an act dependent on thought and timed execution of airflow and oral motor oral placement of the lips tongue and jaw that can be disrupted by weakness in oral musculature dysarthria or an inability to execute the motor movements needed for specific speech sound production apraxia of speech or developmental verbal dyspraxia such deficits can be related to pathology of the nervous system central and or peripheral systems involved in motor planning that affect the timing of respiration phonation prosody and articulation in isolation or in conjunction
mottle is a pattern of irregular marks spots streaks blotches or patches of different shades or colours it is commonly used to describe the surface of plants or the skin of animals in plants mottling usually consists of yellowish spots on plants and is usually a sign of disease or malnutrition many plant viruses cause mottling some examples being tobacco vein mottling virus bean pod mottle virus mottling is sometimes used to describe uneven discolored patches on the skin of humans as a result of cutaneous ischemia lowered blood flow to the surfaces of the skin or herpes zoster infections the medical term for mottled skin is dyschromia although this is not always the case mottling can occur in the dying patient and commonly indicates that the end of life is near mottling usually occurs in the extremities lower first and progresses up as cardiac function declines and circulation throughout the body is poor in animals mottling may be a sign of disease but may also be a hereditary trait such as seen with the champagne and leopard complex genes in horses mottles can also refer to discoloration in processed food such as butter in geology mottled refers to a patchy blotch texture of alteration or interbedding commonly found in limestone and commonly caused by bioturbation mottling can also refer to an undesirable defect which can occur with effect coatings most obvious on light metallic finishes the total color impression shows irregular areas of lightness variations these patches are usually visually evaluated described as a mottling effect some also feel that it reminds them of clouds this effect is especially noticeable on large body panels it can be caused by the coating formulation as well as variations in the application process for example disorientation of the metallic flakes or film thickness variations of the basecoat can lead to various mottle sizes resulting in a non uniform appearance the visual perception of mottling is dependent on the viewing distance large mottles can be seen in far distance evaluation while small mottles are more noticeable in close up evaluation the visual evaluation of mottling is very subjective as it dependson the illumination conditions the observing distance and the viewing angle in graphics printing mottling refers to an uneven coloration resulting from letterpressed printing of textured papers mainly in larger colored surfaces due to the uneven surface not all fibers of the paper are evenly saturated with color unlike offset printing
in mathematics motz s problem is a problem which is widely employed as a benchmark for singularity problems to compare the effectiveness of numerical methods the problem was first presented in 1947 by h motz in the paper the treatment of singularities of partial differential equations by relaxation methods
mount minsi forms the pennsylvania side of the delaware water gap and is the eastern extent of the blue mountain it is composed of sandstone and conglomerates of the shawangunk formation
mountain car a standard testing domain in reinforcement learning is a problem in which an under powered car must drive up a steep hill since gravity is stronger than the car s engine even at full throttle the car cannot simply accelerate up the steep slope the car is situated in a valley and must learn to leverage potential energy by driving up the opposite hill before the car is able to make it to the goal at the top of the rightmost hill the domain has been used as a test bed in various reinforcement learning papers
in mathematics the mountain climbing problem is a problem of finding the conditions that two function forming profiles of a two dimensional mountain must satisfy so that two climbers can start on the bottom on the opposite sides of the mountain and coordinate their movements to reach to the top while always staying at the same height this problem was named and posed in this form by james v whittaker but its history goes back to tatsuo homma who solved a version of it the problem has been repeatedly rediscovered and solved independently in different context by a number of people see the references in the past two decades the problem was shown to be connected to the weak fréchet distance of curves in the plane various planar motion planning problems in computational geometry the inscribed square problem semigroup of polynomials etc the problem was popularized in the article by which received the mathematical association of america s lester r ford award in 1990
mourning sickness is a collective emotional condition of recreational grieving by individuals in the wake of celebrity deaths and other public traumas such traumas may be linked to hyper attentive intrusive and voyeuristic media coverage which has been dubbed grief porn
mouth and genital ulcers with inflamed cartilage syndrome also known as magic syndrome is a cutaneous condition with features of both behçet s disease and relapsing polychondritis
a mouth ulcer is an ulcer that occurs on the mucous membrane of the oral cavity mouth ulcers are very common occurring in association with many diseases and by many different mechanisms but usually there is no serious underlying cause the two most common causes of oral ulceration are local trauma e g rubbing from a sharp edge on a broken filling and aphthous stomatitis canker sores a condition characterized by recurrent formation of oral ulcers for largely unknown reasons mouth ulcers often cause pain and discomfort and may alter the person s choice of food while healing occurs e g avoiding acidic or spicy foods and beverages they may form individually or multiple ulcers may appear at the same time a crop of ulcers once formed the ulcer may be maintained by inflammation and or secondary infection rarely a mouth ulcer that does not heal may be a sign of oral cancer
movement disorders can be defined as neurologic syndromes in which either an excess or movement or a paucity of voluntary and automatic movements unrelated to weakness or spasticity the term movement disorders is used synonymously with basal ganglia or extrapyramidal diseases conventionally movement disorders are divided into two major categories 1 hyperkinetic movement disorders also called dyskinesias refers to excessive often repetitive involuntary movements that intrude into the normal flow of motor activity 2 hypokinetic movement disorders refers to akinesia lack of movement hypokinesia reduced amplitude of movements bradykinesia slow movement and rigidity in primary movement disorders the abnormal movement is the primary manifestation of the disorder in secondary movement disorders it is an manifestation of other systemic or neurological disorder
a movement paradox is a phenomenon of grammar that challenges the transformational approach to syntax the importance of movement paradoxes is emphasized by those theories of syntax e g lexical functional grammar head driven phrase structure grammar construction grammar most dependency grammars that reject movement i e the notion that discontinuities in syntax are explained by the movement of constituents
mowat – wilson syndrome is a rare genetic disorder that was clinically delineated by dr d r mowat and dr m j wilson in 1998
moyamoya disease is a disease in which certain arteries in the brain are constricted blood flow is blocked by the constriction and also by blood clots thrombosis a collateral circulation develops around the blocked vessels to compensate for the blockage but the collateral vessels are small weak and prone to bleeding aneurysm and thrombosis on conventional x ray angiography these collateral vessels have the appearance of a puff of smoke described as もやもや moyamoya in japanese
the mozingo reduction also known as mozingo reaction or thioketal reduction is a chemical reaction capable of fully reducing a ketone or aldehyde to the corresponding alkane the reaction scheme is as follows a thioketal is first produced by reaction of the ketone with an appropriate thiol the product is then hydrogenolyzed to the alkane using raney nickel it is sometimes incorrectly stated that raney nickel is a catalyst in this process in fact stoichiometric amounts of raney nickel must be employed because the sulfur atoms are ultimately converted to catalytically inactive nickel sulfides nevertheless this method is much milder than either the clemmensen or wolff kishner reductions which employ strongly acidic or basic conditions respectively that might interfere with other functional groups present in the molecule
mrs miniver s problem is a geometry problem about circles given a circle a find a circle b such that the area of the lens formed by intersecting their two interiors is equal to the area of the symmetric difference of a and b the sum of the area of a − b and the area of b − a
mu waves also known as mu rhythms comb or wicket rhythms arciform rhythms or sensorimotor rhythms are synchronized patterns of electrical activity involving large numbers of neurons probably of the pyramidal type in the part of the brain that controls voluntary movement these patterns as measured by electroencephalography eeg magnetoencephalography meg or electrocorticography ecog repeat at a frequency of 7 5 – 12 5 and primarily 9 – 11 hz and are most prominent when the body is physically at rest unlike the alpha wave which occurs at a similar frequency over the resting visual cortex at the back of the scalp the mu wave is found over the motor cortex in a band approximately from ear to ear a person suppresses mu wave patterns when he or she performs a motor action or with practice when he or she visualizes performing a motor action this suppression is called desynchronization of the wave because eeg wave forms are caused by large numbers of neurons firing in synchrony the mu wave is even suppressed when one observes another person performing a motor action or an abstract motion with biological characteristics researchers such as v s ramachandran and colleagues have suggested that this is a sign that the mirror neuron system is involved in mu wave suppression although others disagree the mu wave is of interest to a variety of scholars scientists who study neural development are interested in the details of the development of the mu wave in infancy and childhood and its role in learning since a group of researchers believe that autism spectrum disorder asd is strongly influenced by an altered mirror neuron system and that mu wave suppression is a downstream indication of mirror neuron activity many of these scientists have kindled a more popular interest in investigating the mu wave in people with asd assorted investigators are also in the process of using mu waves to develop a new technology the brain computer interface bci with the emergence of bci systems clinicians hope to give the severely physically disabled population new methods of communication and a means to manipulate and navigate their environments
mucinoses are a group of cutaneous diseases caused by fibroblasts producing abnormally large amounts of acid mucopolysaccharides i e mucin usually hyaluronic acid
mucinous carcinoma is a type of cancer that arises from epithelial cells these line certain internal organs and skin and produce mucin the main component of mucus when found within the skin mucinous carcinoma is commonly a round elevated reddish and sometimes ulcerated mass usually located on the head and neck
mucinous cystadenocarcinoma is a type of tumor in the cystadenocarcinoma grouping it can occur in the breast as well as in the ovary tumors are normally multilocular with various smooth thin walled cysts within the cysts is found a haemorrhagic or cellular debris
mucinous cystadenoma is a benign cystic tumor lined by a mucinous epithelium it is a type of cystic adenoma cystadenoma mucinous cystadenoma may arise in a number of locations however mucinous cystadenoma at different locations are not generally considered to be related to one another
mucinous nevus also known as nevus mucinosus is a rare cutaneous condition characterized by hamartoma that can be congenital or acquired
mucinous tubular and spindle cell carcinoma mtscc is a rare subtype of renal cell carcinoma rcc that is included in the 2004 who classification of rcc mtscc is a rare neoplasm and is considered as a low grade entity it may be a variant of papillary rcc this tumor occurs throughout life age range 17 – 82 years and is more frequent in females
muckle – wells syndrome mws also known as urticaria deafness amyloidosis syndrome uda is a rare autosomal dominant disease which causes sensorineural deafness recurrent hives and can lead to amyloidosis individuals with mws often have episodic fever chills and joint pain as a result mws is considered a type of periodic fever syndrome mws is caused by a defect in the cias 1 gene which creates the protein cryopyrin mws is closely related to two other syndromes familial cold urticaria and neonatal onset multisystem inflammatory disease — in fact all three are related to mutations in the same gene and subsumed under the term cryopyrin associated periodic syndromes caps
mucoepidermoid carcinoma is the most common type of salivary gland malignancy in adults mucoepidermoid carcinoma can also be found in other organs as bronchi lacrimal sac and thyroid mucicarmine staining is one stain used by pathologist for detection
mucolipidosis ml is a group of inherited metabolic disorders that affect the body s ability to carry out the normal turnover of various materials within cells when originally named the mucolipidoses derived their name from the similarity in presentation to both mucopolysaccharidoses and sphingolipidoses a biochemical understanding of these conditions has changed how they are classified although four conditions i ii iii and iv have been labeled as mucolipidoses type i sialidosis is now classified as a glycoproteinosis and type iv mucolipidosis type iv is now classified as a gangliosidosis
mucolipidosis type iv ml iv or ml 4 is an autosomal recessive lysosomal storage disorder individuals with the disorder have many symptoms including delayed psychomotor development and various ocular aberrations the disorder is caused by mutations in the mcoln 1 gene which encodes a non selective cation channel mucolipin 1 these mutations disrupt cellular functions and lead to a neurodevelopmental disorder through an unknown mechanism researchers dispute the physiological role of the protein product and which ion it transports
mucopolysaccharidoses are a group of metabolic disorders caused by the absence or malfunctioning of lysosomal enzymes needed to break down molecules called glycosaminoglycans these long chains of sugar carbohydrates occur within the cells that help build bone cartilage tendons corneas skin and connective tissue glycosaminoglycans formerly called mucopolysaccharides are also found in the fluids that lubricate joints subjects with a mucopolysaccharidosis either do not produce enough of one of the eleven enzymes required to break down these sugar chains into simpler molecules or they produce enzymes that do not work properly over time these glycosaminoglycans collect in the cells blood and connective tissues the result is permanent progressive cellular damage which affects appearance physical abilities organ and system functioning and in most cases mental development the mucopolysaccharidoses are part of the lysosomal storage disease family a group of more than 40 genetic disorders that result when the lysosome organelle in animal cells malfunctions the lysosome can be thought of as the cell s recycling center because it processes unwanted material into other substances that the cell can utilize lysosomes break down this unwanted matter via enzymes highly specialized proteins essential for survival lysosomal disorders like mucopolysaccharidosis are triggered when a particular enzyme exists in too small an amount or is missing altogether
mucormycosis is any fungal infection caused by fungi in the order mucorales generally species in the mucor rhizopus absidia and cunninghamella genera are most often implicated this disease is often characterized by hyphae growing in and around blood vessels mucormycosis and zygomycosis are sometimes used interchangeably however zygomycota has been identified as polyphyletic and is not included in modern fungal classification systems also while zygomycosis includes entomophthorales mucormycosis excludes this group
mucosal lentigines also known as labial penile and vulvar melanosis and melanotic macules is a cutaneous condition characterized by light brown macules on mucosal surfaces
mucosal melanoma is a rare cutaneous condition characterized by a melanoma of the mucous membranes
mucositis is the painful inflammation and ulceration of the mucous membranes lining the digestive tract usually as an adverse effect of chemotherapy and radiotherapy treatment for cancer mucositis can occur anywhere along the gastrointestinal gi tract but oral mucositis refers to the particular inflammation and ulceration that occurs in the mouth oral mucositis is a common and often debilitating complication of cancer treatment oral and gastrointestinal gi mucositis affects almost all patients undergoing high dose chemotherapy and hematopoietic stem cell transplantation hsct 80 of patients with malignancies of the head and neck receiving radiotherapy and a wide range of patients receiving chemotherapy alimentary tract mucositis increases mortality and morbidity and contributes to rising health care costs for most cancer treatment about 5 15 of patients get mucositis however with 5 fluorouracil 5 fu up to 40 get mucositis and 10 15 get grade 3 4 oral mucositis irinotecan is associated with severe gi mucositis in over 20 of patients 75 85 of bone marrow transplantation recipients experience mucositis of which oral mucositis is the most common and most debilitating especially when melphalan is used in grade 3 oral mucositis the patient is unable to eat solid food and in grade 4 the patient is unable to consume liquids as well radiotherapy to the head and neck or to the pelvis or abdomen is associated with grade 3 and grade 4 oral or gi mucositis respectively often exceeding 50 of patients among patients undergoing head and neck radiotherapy pain and decreased oral function may persist long after the conclusion of therapy fractionated radiation dosage increases the risk of mucositis to 70 of patients in most trials oral mucositis is particularly profound and prolonged among hsct recipients who receive total body irradiation
a mucous retention cyst is a cyst caused by an obstruction of a duct usually belonging to the parotid gland or a minor salivary gland see also mucocele
in vertebrates mucus mjuːkəs myoo kəss adjectival form mucous is a slippery secretion produced by and covering mucous membranes mucous fluid is rich in glycoproteins and water and is typically produced from cells found in mucous glands mucous fluid may also originate from mixed glands which contain both serous and mucous cells it is a viscous colloid containing antiseptic enzymes such as lysozymes immunoglobulins inorganic salts proteins such as lactoferrin and glycoproteins known as mucins that are produced by goblet cells in the mucous membranes and submucosal glands this mucus serves to protect epithelial cells that line the tubes in the respiratory gastrointestinal urogenital visual and auditory systems the epidermis in amphibians and the gills in fish a major function of this mucus is to protect against infectious agents such as fungi bacteria and viruses the average human nose produces about a liter of mucus per day most of the mucus produced is in the gastrointestinal tract bony fish hagfish snails slugs and some other invertebrates also produce external mucus in addition to serving a protective function against infectious agents such mucus provides protection against toxins produced by predators can facilitate movement and may play a role in communication the rest of this article deals with the production and function of mucus in humans
mudplaning is the loss of traction of a wheel when the pavement is covered by a very thin layer of sand and waste oils it may occur during the first rainfall or through other means of dampening on a specific area which has been dry for a period of time when the rain first falls down the thin layer of dust mixes with waste oils and turns into a nearly transparent layer of grease the color of asphalt remains as usual while the underlying mixture may still cause a critical loss of traction comparable to that of driving on rime ice when the rain totally washes the pavement off the grease the effects of mudplaning will be mitigated the whole phenomenon is similar to the formation of black ice which has been responsible for many unavoidable accidents on highways to avoid mudplaning a driver has to check whether the road is taking its first rain after a prolonged drought this can be done by looking at weather reports of that specific area and evaluating its geographic structure if the driver is suspicious of the hazard it would be an option to stop the vehicle and check the tires for artifacts of dust if the tires are getting dirty with no visible sign of the road being so then the road may pose a mudplaning hazard it is advisable to wait for the rain to totally remove the greasy dust on the pavement before resuming the trip
muenke syndrome also known as fgfr 3 related craniosynostosis is a human specific condition characterized by the premature closure of certain bones of the skull during development which affects the shape of the head and face first described by maximilian muenke the syndrome occurs in about 1 in 30 000 newborns this condition accounts for an estimated 8 percent of all cases of craniosynostosis
muir – torre syndrome mts is a rare hereditary autosomal dominant cancer syndrome that is thought to be a subtype of hnpcc individuals are prone to develop cancers of the colon breast and genitourinary tract and skin lesions such as keratoacanthomas and sebaceous tumors the genes affected are mlh 1 msh 2 and more recently msh 6 and are involved in dna mismatch repair
the mukaiyama aldol addition is an organic reaction and a type of aldol reaction between a silyl enol ether and an aldehyde or formate the reaction was discovered by teruaki mukaiyama 1927 in 1973 his choice of reactants allows for a crossed aldol reaction between an aldehyde and a ketone or a different aldehyde without self condensation of the aldehyde for this reason the reaction is used extensively in organic synthesis
mukamel syndrome is a cutaneous condition characterized by premature graying lentigines depigmented macules microcephaly and scoliosis
mulberry molars are a dental condition usually associated with congenital syphilis characterized by multiple rounded rudimentary enamel cusps on the permanent first molars mulberry molars are physically defective permanent molars the deformity is caused by congenital syphilis this type of abnormality is characterized by dwarfed molars with cusps covered with globular enamel growths these teeth are functional but can be cosmetically fixed with crowns bridges or implants just above the gum line the mulberry molar looks normal a deformity becomes apparent towards the cusp or top grinding surface of the tooth here the size of the mulberry molar is diminished in all aspects creating a stumpy version of a conventional molar the cause of the molar atrophy is thought to be enamel hypoplasia or a deficiency in tooth enamel the underlying dentin and pulp of the tooth is normal but the enamel covering or molar sheath is thin and deformed creating a smaller version of a typical tooth the grinding surface of a mulberry molar is also corrupted normally the grinding surface of a molar has a pit and is surrounded by a circular ridge at the top of the tooth which is used for grinding the cusp deformity of the mulberry molar is characterized by an extremely shallow or completely absent pit instead the pit area is filled with globular structures bunched together all along the top surface of the cusp this type of deformity is also thought to be caused by enamel hypoplasia mulberry molars are typically functional and do not need treatment if the deformity is severe or the person is bothered by the teeth there are several options the teeth can be covered with a permanent cast crown stainless steel crown or the molars can be removed and an implant or bridge can be put in place of the mulberry molar a mulberry molar is caused by congenital syphilis which is passed from the mother to the child in the uterus through the placenta since this particular symptom of congenital syphilis manifests later in childhood with the eruption of the permanent molars it is a late stage marker for the disease hutchinson ’ s teeth marked by dwarfed teeth and deformed cusps that are spaced abnormally far apart are another dental deformity caused by congenital syphilis mulberry molars and hutchinson ’ s teeth will often occur together pregnant women with syphilis should tell their doctors about the condition and be treated for it during pregnancy otherwise the baby should be screened for the disease after birth and treated with penicillin if necessary
mule spinners cancer or mule spinners cancer was a cancer an epithelioma of the scrotum it was first reported in 1887 in a cotton mule spinner in 1926 a british home office committee strongly favoured the view that this form of cancer was caused by the prolonged action of mineral oils on the skin of the scrotum and of these oils shale oil was deemed to be the most carcinogenic from 1911 to 1938 there were 500 deaths amongst cotton mule spinners from cancer of the scrotum but only three amongst wool mule spinners
mulibrey nanism muscle liver brain eye nanism also called perheentupa syndrome and pericardial constriction with growth failure is a rare autosomal recessive congenital disorder it causes severe growth failure dwarfism along with abnormalities of the heart muscle liver brain and eye mulibrey nanism has been associated with a recessive defect in the gene trim 37 trim 37 is responsible for various cellular functions including developmental patterning
the multi terrain pattern mtp is a camouflage pattern printed on equipment issued to british forces as part of the british ministry of defence s mod personal equipment and common operational clothing pecoc programme three new camouflage patterns were considered for issue to british forces these were a revised temperate dpm using lighter colours a new three colour desert pattern with enhanced utility for night time operations and a hybrid four colour scheme using two colours from each of the previous patterns for use on webbing in all terrains following an urgent operational requirement for a camouflage uniform for the afghan theatre of operations and the success of a commercially available pattern crye s multicam when tested in trials a decision was made to use multicam as the basis of a new multi terrain pattern for british armed forces replacing the previous temperate dpm uniforms desert dpm uniforms were to be retained the united kingdom s ministry of defence announced that hm forces would be issued with the new british army uniform for operations in afghanistan initially issued to personnel deployed on operation herrick from march 2010 then issued more widely to hm forces from 2011 onward replacing all dpm variants of the combat soldier 95 uniform by 2013
in probability theory the multi armed bandit problem sometimes called the k or n armed bandit problem is a problem in which a gambler at a row of slot machines sometimes known as one armed bandits has to decide which machines to play how many times to play each machine and in which order to play them when played each machine provides a random reward from a probability distribution specific to that machine the objective of the gambler is to maximize the sum of rewards earned through a sequence of lever pulls robbins in 1952 realizing the importance of the problem constructed convergent population selection strategies in some aspects of the sequential design of experiments a theorem the gittins index first published by john c gittins gives an optimal policy for maximizing the expected discounted reward in practice multi armed bandits have been used to model the problem of managing research projects in a large organization like a science foundation or a pharmaceutical company given a fixed budget the problem is to allocate resources among the competing projects whose properties are only partially known at the time of allocation but which may become better understood as time passes in early versions of the multi armed bandit problem the gambler has no initial knowledge about the machines the crucial tradeoff the gambler faces at each trial is between exploitation of the machine that has the highest expected payoff and exploration to get more information about the expected payoffs of the other machines the trade off between exploration and exploitation is also faced in reinforcement learning
the multi commodity flow problem is a network flow problem with multiple commodities flow demands between different source and sink nodes
in chemistry a multi component reaction or mcr sometimes referred to as a multi component assembly process or mcap is a chemical reaction where three or more compounds react to form a single product by definition multicomponent reactions are those reactions whereby more than two reactants combine in a sequential manner to give highly selective products that retain majority of the atoms of the starting material
multi drug resistant tuberculosis mdr tb also known as vank s disease is defined as a form of tb infection caused by bacteria that are resistant to treatment with at least two of the most powerful first line anti tb drugs isoniazid inh and rifampicin rmp five percent 5 of all tb cases across the globe in 2013 were estimated to be mdr tb cases including 3 5 of newly diagnosed tb cases and 20 5 of previously treated tb cases while rates of mdr tb infections are relatively low in north america and western europe they are an increasingly serious problem worldwide in particular in areas of the russian federation the former soviet union and other parts of asia mdr tb infection may be classified as either primary or acquired primary mdr tb occurs in patients who have not previously been infected with tb but who become infected with a strain that is resistant to treatment acquired mdr tb occurs in patients during treatment with a drug regimen that is not effective at killing the particular strain of tb with which they have been infected rates of primary mdr tb are low in north america and western europe in the us in 2000 the rate of primary mdr tb was 1 of all cases of tb nationally most cases of acquired mdr tb are due to inappropriate treatment with a single anti tb drug usually inh this can occur due to a medical provider such as a doctor or nurse improperly prescribing ineffective treatment but may also be due to the patient not taking the medication correctly which can be due to a variety of reasons including expense or scarcity of medicines patient forgetfulness or patient stopping treatment early because they feel better treatment of mdr tb requires treatment with second line drugs usually four or more anti tb drugs for a minimum of 6 months and possibly extending for 18 – 24 months if rifampin resistance has been identified in the specific strain of tb with which the patient has been infected in general second line drugs are less effective more toxic and much more expensive than first line drugs under ideal program conditions mdr tb cure rates can approach 70
multicam is a crye precision camouflage pattern designed for use in a wide range of conditions variants of it some unlicensed are in use with armed forces the pattern is also sold for civilian usage
a multiburst waveform is a useful test pattern used to quickly ascertain the frequency response of a video system the name derives from the multiple bursts of sine wave in the active video section of the waveform which are generated with usually increasing frequency but identical in amplitude the test pattern is usually input at the start of the signal chain and analysed at the end by measuring the amplitude of each of the bursts of waveform at the end of the video chain spot measurements of the frequency response of the system can be obtained and errors in the response quickly identified
in contrast to unicameralism multicameralism is the condition in which a legislature is divided into several deliberative assemblies which are commonly called chambers or houses this can include bicameralism with two chambers tricameralism with three tetracameralism with four branches or a system with any amount more the word multicameral can also relate in other ways to its literal meaning of many chambered with use in science or biology many modern parliaments and congresses adopt a multicameral usually bicameral structure to provide multiple perspectives and a form of separation of powers within the legislature
multicentric reticulohistiocytosis is a multisystem disease beginning usually around the age of 50 years and is twice as common in women
multichannel marketing is the ability to interact with potential customers on various platforms in this sense a channel might be a print ad a retail location a website a promotional event a products package or even word of mouth multichannel marketing is about choice the objective of the companies doing the marketing is to make it easy for a consumer to buy from them in whatever way is most appropriate to be effective multichannel marketing needs to be supported by good supply chain management systems so that the details and prices of goods on offer are consistent across the different channels it might also be supported by detailed analysis of the return on investment from each different channel measured in terms of customer response and conversion of sales the contribution each channel delivers to sales can be assessed via attribution modeling some companies target certain channels at different demographic segments of the market or at different socio economic groups of consumers multichannel marketing allows the retail merchant to reach its prospective or current customer in a channel of his her liking
in machine learning multiclass or multinomial classification is the problem of classifying instances into one of the more than two classes classifying instances into one of the two classes is called binary classification while some classification algorithms naturally permit the use of more than two classes others are by nature binary algorithms these can however be turned into multinomial classifiers by a variety of strategies multiclass classification should not be confused with multi label classification where multiple labels are to be predicted for each instance
multicystic dysplastic kidney mcdk is a condition that results from the malformation of the kidney during fetal development the kidney consists of irregular cysts of varying sizes multicystic dysplastic kidney is a common type of renal cystic disease and it is a cause of an abdominal mass in infants
multidrug tolerance or antibiotic tolerance is the ability of a disease causing microorganism to resist killing by antibiotics or other antimicrobials it is mechanistically distinct from multidrug resistance it is not caused by mutant microbes but rather by microbial cells that exist in a transient dormant non dividing state microorganisms that display multidrug tolerance can be bacteria fungi or parasites
multifocal or multiform atrial tachycardia mat is an abnormal heart rhythm specifically a type of supraventricular tachycardia that is particularly common in older people and is associated with exacerbations of chronic obstructive pulmonary disease copd normally the heart rate is controlled by a cluster of cells called the sinoatrial node sa node when a number of different clusters of cells outside of the sa node take over control of the heart rate and the rate exceeds 100 beats per minute this is called multifocal atrial tachycardia if the heart rate is ≤ 100 this is technically not a tachycardia and it is then termed multifocal atrial rhythm multiform simply describes the variable p wave shapes and is an observation multifocal is an inference about the underlying cause although these are interchangeable terms some purists prefer the former nomenclature since it does not presume any underlying mechanism
multifocal choroiditis and panuveitis mcp is an idiopathic inflammatory disorder of unknown etiology affecting the choroid retina and vitreous of the eye that presents asymmetrically most often in young myopic women with photopsias enlargement of the physiologic blind spot and decreased vision the first description of the disease was written in 1973
multifocal fibrosclerosis and idiopathic fibrosclerosis are disorders of unknown aetiology characterised by fibrous lesions co occurring at a variety of sites known manifestations include retroperitoneal fibrosis mediastinal fibrosis and riedel s thyroiditis they are now considered to be manifestations of igg 4 related disease
multifocal micronodular pneumocyte hyperplasia mmph is a subtype of pneumocytic hyperplasia hyperplasia of pneumocytes lining pulmonary alveoli several synonymous terms have been done for this entity adenomatoid proliferation of alveolar epithelium papillary alveolar hamartoma multifocal alveolar hyperplasia multinodular pneumocyte hyperplasia these multifocal lesions are observed in tuberous sclerosis and can be associated with lymphangioleiomyomatosis and perivascular epithelioid cell tumour pecoma or clear cell sugar tumor it can be diagnosed through lung biopsy using thoracoscopy
multifocal motor neuropathy mmn is a progressively worsening condition where muscles in the extremities gradually weaken the disorder a pure motor neuropathy syndrome is sometimes mistaken for amyotrophic lateral sclerosis als because of the similarity in the clinical picture especially if muscle fasciculations are present mmn is thought to be autoimmune it was first described in the mid 1980 s unlike als which affects both upper and lower motor nerves mmn involves only lower motor nerves nevertheless definitive diagnosis is often difficult and many mmn patients labor for months or years under an als diagnosis before finally getting a determination of mmn mmn usually involves very little pain however muscle cramps spasms and twitches can cause pain for some sufferers mmn is not fatal and does not diminish life expectation many patients once undergoing treatment only experience mild symptoms over prolonged periods though the condition remains slowly progressive mmn can however lead to significant disability with loss of function in hands affecting ability to work and perform everyday tasks and foot drop leading to inability to stand and walk some patients end up using aids like canes splints and walkers
multifocal stenosing ulceration of the small intestine is a rare condition that is characterised by recurrent ulcers of the small intestine
multilocular cystic clear cell renal cell carcinoma is rare subtype of renal cell carcinoma
a multinodular goiter is a multinodular enlargement of the thyroid gland the multinodular goiter can be associated with hyperthyroidism toxic multinodular goitre or not it is a non tumoral condition but a thyroid cancer is identified in 13 7 of the patients operated for multinodular goiter these nodules grow up at varying rates and secrete thyroid hormone autonomously thereby suppressing tsh dependent growth and function in the rest of gland
multinucleate cell angiohistocytoma is a cutaneous condition that presents as slowly growing multiple discrete but grouped red to violaceous papules
the multipactor effect is a phenomenon in radio frequency rf amplifier vacuum tubes and waveguides where under certain conditions secondary electron emission in resonance with an alternating electric field leads to exponential electron multiplication possibly damaging and even destroying the rf device
multipath interference is a phenomenon in the physics of waves whereby a wave from a source travels to a detector via two or more paths and under the right condition the two or more components of the wave interfere multipath interference is a common cause of ghosting in analog television broadcasts
in wireless telecommunications multipath is the propagation phenomenon that results in radio signals reaching the receiving antenna by two or more paths causes of multipath include atmospheric ducting ionospheric reflection and refraction and reflection from water bodies and terrestrial objects such as mountains and buildings multipath causes multipath interference including constructive and destructive interference and phase shifting of the signal destructive interference causes fading where the magnitudes of the signals arriving by the various paths have a distribution known as the rayleigh distribution this is known as rayleigh fading where one component often but not necessarily a line of sight component dominates a rician distribution provides a more accurate model and this is known as rician fading
when a patient has multiple abnormalities multiple anomaly multiple deformity they have a congenital abnormality that can not be primarily identified with a single system of the body or single disease process most medical conditions can have systemic sequelae but multiple abnormalities occur when the effects on multiple systems is immediately obvious
multiple carboxylase deficiency is a form of metabolic disorder involving failures of carboxylation enzymes the deficiency can be in biotinidase or holocarboxylase synthetase these conditions respond to biotin forms include holocarboxylase synthetase deficiency neonatal biotinidase deficiency late onset if left untreated the symptoms can include feeding problems hypotonia generalised erythematous rash with skin exfoliation and alopecia failure to thrive seizure coma developmental delay foul smelling urine metabolic acidosis ketosis and hyperammonemia
multiple chemical sensitivity mcs or idiopathic environmental intolerances iei is a chronic medical condition and syndrome characterized by symptoms that the affected person attributes to low level chemical exposures to commonly used chemicals commonly attributed substances include scented products pesticides plastics synthetic fabrics smoke petroleum products and paint fumes symptoms are subjective and vague symptoms are also non specific meaning that they are common symptoms such as fatigue or headaches that are present in hundreds of other illnesses commonly reported symptoms also include nausea dizziness and inflammation of skin joints gastrointestinal tract and airways although the symptoms themselves are real and can be disabling mcs is not recognized as an organic chemical caused illness by the world health organization american medical association or any of several other professional medical organizations blinded clinical trials have shown mcs patients react as often and as strongly to placebos as they do to chemical stimuli the existence and severity of symptoms is related to perception that a chemical stimulus is present depression anxiety somatoform disorder and similar mental health conditions are commonly associated with reports of mcs prior to the mid 1980 s when the term multiple chemical sensitivity was coined the syndrome went by such names as universal allergy 20 th century disease chemical hypersensitivity syndrome total allergy syndrome and cerebral allergy
the term multiple endocrine neoplasia men encompasses several distinct syndromes featuring tumors of endocrine glands each with its own characteristic pattern in some cases the tumors are malignant in others benign benign or malignant tumors of nonendocrine tissues occur as components of some of these tumor syndromes men syndromes are inherited as autosomal dominant disorders
multiple endocrine neoplasia type 1 men 1 syndrome or wermer s syndrome is part of a group of disorders the multiple endocrine neoplasias that affect the endocrine system through development of neoplastic lesions in pituitary parathyroid gland and pancreas
multiple endocrine neoplasia type 2 men 2 also known as pheochromocytoma and amyloid producing medullary thyroid carcinoma ptc syndrome and sipple syndrome is a group of medical disorders associated with tumors of the endocrine system the tumors may be benign or malignant cancer they generally occur in endocrine organs e g thyroid parathyroid and adrenals but may also occur in endocrine tissues of organs not classically thought of as endocrine men 2 is a sub type of men multiple endocrine neoplasia and itself has sub types as discussed below
multiple endocrine neoplasia type 2 b also known as men 2 b mucosal neuromata with endocrine tumors multiple endocrine neoplasia type 3 and wagenmann – froboese syndrome is a genetic disease that causes multiple tumors on the mouth eyes and endocrine glands it is the most severe type of multiple endocrine neoplasia differentiated by the presence of benign oral and submucosal tumors in addition to endocrine malignancies it was first described by wagenmann in 1922 and was first recognized as a syndrome in 1965 1966 by e d williams and d j pollock men 2 b typically manifests before a child is 10 years old affected individuals tend to be tall and lanky with an elongated face and protruding blubbery lips benign tumors neoplasms develop in the mouth eyes and submucosa of almost all organs in the first decade of life medullary thyroid cancer almost always occurs sometimes in infancy it is often aggressive cancer of the adrenal glands pheochromocytoma occurs in 50 of cases a variety of eponyms have been proposed for men 2 b such as williams pollock syndrome gorlin vickers syndrome and wagenmann froboese syndrome however none ever gained sufficient traction to merit continued use and are no longer used in the medical literature the prevalence of men 2 b is not well established but has been derived from other epidemiological considerations as 1 in 600 000 to 1 in 4 000 000 the annual incidence has been estimated at 4 per 100 million per year
fairbank s disease or multiple epiphyseal dysplasia med is a rare genetic disorder dominant form 1 in 10 000 births that affects the growing ends of bones bones usually elongate by a process that involves the depositing of cartilage at the ends of the bones called ossification this cartilage then mineralizes and hardens to become bone in med this process is defective
multiple evanescent white dot syndrome mewds is an uncommon inflammatory condition of the retina that typically affects otherwise healthy young females in the second to fourth decades of life the typical patient with mewds is a healthy middle aged female age 15 50 there is a gender disparity as women are affected with mewds four times more often than men roughly 30 of patients have experienced an associated viral prodrome patients present with acute painless unilateral change in vision
in solar cell research carrier multiplication is the phenomenon wherein the absorption of a single photon leads to the excitation of multiple electrons from the valence band to conduction band in the theory of a conventional solar cell each photon is only able to excite one electron across the band gap of the semiconductor and any excess energy in that photon is dissipated as heat in a material with carrier multiplication high energy photons excite on average more than one electron across the band gap and so in principle the solar cell can produce more useful work in quantum dot solar cells the excited electron in the conduction band interacts with the hole it leaves behind in the valence band and this composite uncharged object is known as an exciton the carrier multiplication effect in a dot can be understood as creating multiple excitons and is called multiple exciton generation meg meg may considerably increase the energy conversion efficiency of nanocrystal based solar cells though extracting the energy may be difficult because of the short lifetimes of the multiexcitons the quantum mechanical origin of meg is still under debate and several possibilities have been suggested 1 impact ionization light excites a high energy exciton x which decays irreversibly into a quasi continuum of multiexciton multi x states available at this energy the model requires only the density of states of multiexcitons being very high while the coulomb coupling between x and multi x can be quite small 2 coherent superposition of single and multiexciton states the very first suggested model but oversimplified high density of states of multi x is not taken into account light excites an x which is not a true eigenstate of the system which can then coherently covert to multi x and back to x many times quantum beats this process requires coulomb coupling between them to be much stronger than the decay rate via phonons which is usually not the case the excitation will finally decay via phonons to a lower energy x or multi x depending on which of the decays is faster 3 multiexciton formation through a virtual exciton state light directly excites the eigenstate of the system in this case a coherent mixture of x and multi x the term virtual relates here to a pure x because it is not a true eigenstate of the system same for model 2 all of the above models can be described by the same mathematical model density matrix which can behave differently depending on the set of initial parameters coupling strength between the x and multi x density of states decay rates meg was first demonstrated in 2004 using colloidal pbse quantum dots and later was observed for quantum dots of other compositions including pbs pbte cds cdse inas si and inp multiple exciton generation was also detected in semiconducting single walled carbon nanotubes swnts upon absorption of single photons for 6 5 swnts absorption of single photons with energies corresponding to three times the swnt energy gap results in an exciton generation efficiency of 130 per photon the multiple exciton generation threshold in swnts can be close to the limit defined by energy conservation graphene which is closely related to nanotubes is another material in which multiple exciton generation has been observed double exciton generation has additionally been observed in organic pentacene derivatives through singlet exciton fission with extremely high quantum efficiency
multiple familial trichoepithelioma also known as brooke – spiegler syndrome and epithelioma adenoides cysticum is a cutaneous condition characterized by multiple cystic and solid nodules appearing on the face
multiple hamartoma syndrome is a condition characterized by more than one hamartoma it is sometimes equated with cowden syndrome however mesh also includes bannayan zonana syndrome and lhermitte duclos disease under this description
multiple minute digitate hyperkeratosis also known as digitate keratoses disseminated spiked hyperkeratosis familial disseminated piliform hyperkeratosis and minute aggregate keratosis is a rare cutaneous condition with about half of cases being familial inherited in an autosomal dominant fashion while the other half are sporadic this disease has a unique histology so a biopsy and further tests should be done to confirm the diagnosis and rule out other disorders and malignancy
multiple morbidities or multimorbidities is a term which means co occurring diseases for example a person could have diabetes and heart disease and high blood pressure in the medicare population 65 of patients have two or more chronic illnesses some of the difficulties experienced by patients include poor coordination of medical care managing multiple medications and aggravation of one condition by symptoms or treatment of another these are common in people who are elderly malnourished or poor
multiple myeloma also known as plasma cell myeloma is a cancer of plasma cells a type of white blood cell normally responsible for producing antibodies initially there are often no symptoms when advanced bone pain bleeding frequent infections and anemia may occur complications may include amyloidosis the cause is generally unknown risk factors include drinking alcohol and obesity the underlying mechanism involves abnormal plasma cells producing abnormal antibodies which can cause kidney problems and overly thick blood the plasma cells can also form a mass in the bone marrow or soft tissue when there is only one mass it is known as a plasmacytoma and when there is more than one it is known as multiple myeloma multiple myeloma is diagnosed based on blood or urine tests finding abnormal antibodies bone marrow biopsy finding cancerous plasma cells and medical imaging finding bone lesions another common finding is high blood calcium levels multiple myeloma is considered treatable but generally incurable remissions may be brought about with steroids chemotherapy thalidomide or lenalidomide and stem cell transplant bisphosphonates and radiation therapy are sometimes used to reduce pain from bone lesions multiple myeloma affected about 427 000 people in 2013 and resulted in 79 000 deaths in the united states it develops in 6 5 per 100 000 people per year and 0 7 of people are affected at some point in their life it usually occurs around the age of 61 and is more common in men than women without treatment typical survival is seven months with current treatments survival is usually 4 – 5 years this gives a five year survival rate of about 49 the word myeloma is from the greek myelo meaning marrow and oma meaning tumor
multiple organ dysfunction syndrome mods also known as multiple organ failure mof total organ failure tof or multisystem organ failure msof is altered organ function in an acutely ill patient requiring medical intervention to achieve homeostasis although irwin rippe cautions in 2005 that the use of multiple organ failure or multisystem organ failure should be avoided both harrison s 2015 and cecil s 2012 medical textbooks still use the terms multi organ failure and multiple organ failure in several chapters and do not use multiple organ dysfunction syndrome at all
multiple pterygium syndrome is a cutaneous condition inherited in an autosomal dominant fashion
multiple rule based problems are problems containing various conflicting rules and restrictions such problems typically have an optimal solution found by striking a balance between the various restrictions without directly defying any of the aforementioned restrictions solutions to such problems can either require complex non linear thinking processes or can instead require mathematics based solutions in which an optimal solution is found by setting the various restrictions as equations and finding an appropriate maximum value when all equations are added these problems may thus require more working information as compared to causal relationship problem solving or single rule based problem solving the multiple rule based problem solving is more likely to increase cognitive load than are the other two types of problem solving
multiple sclerosis ms is a demyelinating disease in which the insulating covers of nerve cells in the brain and spinal cord are damaged this damage disrupts the ability of parts of the nervous system to communicate resulting in a range of signs and symptoms including physical mental and sometimes psychiatric problems specific symptoms can include double vision blindness in one eye muscle weakness trouble with sensation or trouble with coordination ms takes several forms with new symptoms either occurring in isolated attacks relapsing forms or building up over time progressive forms between attacks symptoms may disappear completely however permanent neurological problems often remain especially as the disease advances while the cause is not clear the underlying mechanism is thought to be either destruction by the immune system or failure of the myelin producing cells proposed causes for this include genetics and environmental factors such as being triggered by a viral infection ms is usually diagnosed based on the presenting signs and symptoms and the results of supporting medical tests there is no known cure for multiple sclerosis treatments attempt to improve function after an attack and prevent new attacks medications used to treat ms while modestly effective can have side effects and be poorly tolerated physical therapy can help with people s ability to function many people pursue alternative treatments despite a lack of evidence the long term outcome is difficult to predict with good outcomes more often seen in women those who develop the disease early in life those with a relapsing course and those who initially experienced few attacks life expectancy is on average 5 to 10 years lower than that of an unaffected population multiple sclerosis is the most common autoimmune disorder affecting the central nervous system in 2013 about 2 3 million people were affected globally with rates varying widely in different regions and among different populations that year about 20 000 people died from ms up from 12 000 in 1990 the disease usually begins between the ages of 20 and 50 and is twice as common in women as in men ms was first described in 1868 by jean martin charcot the name multiple sclerosis refers to the numerous scars sclerae — better known as plaques or lesions that develop on the white matter of the brain and spinal cord a number of new treatments and diagnostic methods are under development
multiple sulfatase deficiency also known as austin disease and mucosulfatidosis is a very rare autosomal recessive lysosomal storage disease caused by a deficiency in multiple sulfatase enzymes or in formylglycine generating enzyme which activates sulfatases it is similar to mucopolysaccharidosis
multiple system atrophy msa is a degenerative neurological disorder that depicts a group of disorders characterised by the neuronal degeneration mainly in the substantia nigra striatum autonomic nervous system and cerebellum following a report in 1964 of what was then called striatonigral degeneration many patients were recognised in whom the changes of striatonigral and olivopontocerebellar degeneration were combined and who had symptoms and signs of cerebellar ataxia and parkinsonian manifestations more than half of the patients with striatonigral degeneration have orthostatic hypotension which proves at autopsy to be associated with loss of intermediolateral horn cells origin of the presynaptic cholinergic sympathetic neurones and of pigmented nuclei of the brainstem this combined parkinsonian and autonomic disorder is referred to as the shy – drager syndrome in addition to orthostatic hypotension other features of autonomic failure include impotence loss of sweating dry mouth and urinary retention and incontinence vocal cord palsy is an important and sometimes initial clinical manifestation of the disorder both mri and ct scanning frequently show atrophy of the cerebellum and pons in those with cerebellar features the putamen is hypodense on t 2 weighted mri and may show an increased deposition of iron in parkinsonian form in cerebellar form a hot cross sign has been emphasised it reflects atrophy of the pontocereballar fibres that manifest in t 2 signal intensity in atrophic pons the cause of msa is unclear and no specific risk factors have been identified although research indicates that a prion form of the alpha synuclein protein may be the cause of the disease approximately 55 of msa cases occur in men with typical age of onset in the late 50 s to early 60 s msa often presents with some of the same symptoms as parkinson s disease however those with msa generally show minimal if any response to the dopamine medications used for parkinson s disease msa is distinct from the more common syndrome multisystem proteinopathy it should also not be confused with the two terms multiple organ dysfunction syndrome or multiple organ system dysfunction syndrome which are the more modern and accurate terms for multiple organ failure or multiple organ system failure which is an often fatal complication of septic shock due to severe sepsis a systemic infection that has spread to the bloodstream or other very severe illnesses or injuries
in number theory a multiplicative function is an arithmetic function f n of the positive integer n with the property that f 1 1 and whenevera and b are coprime then f ab f a f b an arithmetic function f n is said to be completely multiplicative or totally multiplicative if f 1 1 and f ab f a f b holds for all positive integers a and b even when they are not coprime
multiplicative number theory is a subfield of analytic number theory that deals with prime numbers and with factorization and divisors the focus is usually on developing approximate formulas for counting these objects in various contexts the prime number theorem is a key result in this subject the mathematics subject classification for multiplicative number theory is 11 nxx
in macroeconomics multiplier uncertainty is lack of perfect knowledge of the multiplier effect of a particular policy action such as a monetary or fiscal policy change upon the intended target of the policy for example a fiscal policy maker may have a prediction as to the value of the fiscal multiplier — the ratio of the effect of a government spending change on gdp to the size of the government spending change — but is not likely to know the exact value of this ratio similar uncertainty may surround the magnitude of effect of a change in the monetary base or its growth rate upon some target variable which could be the money supply the exchange rate the inflation rate or gdp there are several policy implications of multiplier uncertainty 1 if the multiplier uncertainty is uncorrelated with additive uncertainty its presence causes greater cautiousness to be optimal the policy tools should be used to a lesser extent 2 in the presence of multiplier uncertainty it is no longer redundant to have more policy tools than there are targeted economic variables 3 certainty equivalence no longer applies under quadratic loss optimal policy is not equivalent to a policy of ignoring uncertainty
in computer science multiprocessor scheduling is an np hard optimization problem the problem statement is given a set j of jobs where job ji has length li and a number of processors m what is the minimum possible time required to schedule all jobs in j on m processors such that none overlap the applications of this problem are numerous but are as suggested by the name of the problem most strongly associated with the scheduling of computational tasks in a multiprocessor environment multiprocessor schedulers have to schedule tasks which may or may not be dependent upon one another for example take the case of reading user credentials from console then use it to authenticate then if authentication is successful display some data on the console clearly one task is dependent upon another this is a clear case of where some kind of ordering exists between the tasks in fact it is clear that it can be modelled with partial ordering then by definition the set of tasks constitute a lattice structure the general multiprocessor scheduling problem is a generalization of the optimization version of the number partitioning problem which considers the case of partitioning a set of numbers jobs into two equal sets processors
in computer architecture multithreading is the ability of a central processing unit cpu or a single core in a multi core processor to execute multiple processes or threads concurrently appropriately supported by the operating system this approach differs from multiprocessing as with multithreading the processes and threads have to share the resources of a single or multiple cores the computing units the cpu caches and the translation lookaside buffer tlb where multiprocessing systems include multiple complete processing units multithreading aims to increase utilization of a single core by using thread level as well as instruction level parallelism as the two techniques are complementary they are sometimes combined in systems with multiple multithreading cpus and in cpus with multiple multithreading cores
in software engineering the multiton pattern is a design pattern similar to the singleton which allows only one instance of a class to be created the multiton pattern expands on the singleton concept to manage a map of named instances as key value pairs rather than having a single instance per application e g the a rel nofollow class external text href docs oracle com javase 8 docs api java lang runtime html java lang runtime a object in the java programming language the multiton pattern instead ensures a single instance per key most people and textbooks consider this a singleton pattern for example multiton does not explicitly appear in the highly regarded object oriented programming textbook design patterns it appears as a more flexible approach named registry of singletons
the multiuse model view mmv is an architectural pattern used in software engineering that came about as an enhancement to the mvvm design pattern the pattern is specific for windows presentation foundation wpf and windows communication foundation wcf applications while keeping the logical separation of user interface view versus logic model mmv s primary objective is to address the shortcomings of the mvvm pattern the multiuse model of mmv typically relies on reflection to facilitate object building in order to easily integrate logic centric object models with view centric object models minimizing the amount of duplicate code mmv was designed to make use of specific functions in c wpf and wcf to better facilitate the reuse of code between the server and the client
in statistics the multivariate behrens – fisher problem is the problem of testing for the equality of means from two multivariate normal distributions when the covariance matrices are unknown and possibly not equal since this is a generalization of the univariate behrens fisher problem it inherits all of the difficulties that arise in the univariate problem
multivesicular release mvr is the phenomenon by which individual chemical synapses forming the junction between neurons is mediated by multiple releasable vesicles of neurotransmitter in neuroscience it is a subject of debate whether one or many vesicles are released per action potential
the mumm rearrangement is an organic reaction and a rearrangement reaction it describes a 1 3 o n acyl transfer of an acyl imidate or isoimide group to an imide the mumm rearrangement the reaction is of relevance as part of the ugi reaction
for other uses of the word mumps see mumps disambiguation mumps also known as epidemic parotitis is a viral disease caused by the mumps virus initial signs and symptoms often include fever muscle pain headache and feeling tired this is then usually followed by painful swelling of one or both parotid salivary glands symptoms typically occur 16 to 18 days after exposure and resolve after seven to ten days symptoms in adults are often more severe than in children about a third of people have mild or no symptoms complications may include infections of the covering of the brain 15 percent pancreatitis four percent permanent deafness and painful testicular swelling which uncommonly results in infertility women may develop ovarian swelling but this does not increase the risk of infertility mumps is highly contagious and spreads rapidly among people living in close quarters the virus is transmitted by respiratory droplets or direct contact with an infected person only humans get and spread the disease people are infectious to each other from about seven days before the start of symptoms to about eight days after after an infection a person is typically immune for life reinfection is possible but tends to be mild diagnosis is usually suspected due to parotid swelling and can be confirmed by isolating the virus on a swab of the parotid duct testing for igm antibodies in the blood is simple and may be useful however can be falsely negative in those who have been immunized mumps is preventable by two doses of the mumps vaccine most of the developed world includes it in their immunization programs often in combination with measles and rubella vaccine countries that have low immunization rates may see an increase in cases among older age groups and thus worse outcomes there is no specific treatment efforts involve controlling symptoms with pain medication such as acetaminophen intravenous immunoglobulin may be useful in certain complications hospitalization may be required if meningitis or pancreatitis develops about one per ten thousand people who are infected die without immunization about 0 1 percent to one percent of the population are affected per year widespread vaccination has resulted in a more than 90 percent decline in rates of disease mumps is more common in the developing world where vaccination is less common outbreaks however may still occur in a vaccinated population before the introduction of a vaccine mumps was a common childhood disease worldwide larger outbreaks of disease would typically occur every two to five years children between the ages of five and nine were most commonly affected among immunized population often those in their early 20 s are affected around the equator it often occurs all year round while in the more northerly and southerly regions of the world it is more common in the winter and spring painful swelling of the parotid glands and testicles was described by hippocrates in the 5 th century bce
munchausen by internet is a pattern of behavior akin to the munchausen syndrome a psychiatric factitious disorder wherein those affected feign disease illness or psychological trauma to draw attention sympathy or reassurance to themselves in which internet users seek attention by feigning illnesses in online venues such as chat rooms message boards and internet relay chat irc it has been described in medical literature as a manifestation of factitious disorder or factitious disorder by proxy reports of users who deceive internet forum participants by portraying themselves as gravely ill or as victims of violence first appeared in the 1990 s due to the relative newness of internet communications the pattern was identified in 1998 by psychiatrist marc feldman who created the term münchausen by internet in 2000 it is not included in the fifth revision of the diagnostic and statistical manual of mental disorders dsm 5 the development of factitious disorders in online venues is made easier by the availability of medical literature on the internet the anonymous and malleable nature of online identities and the existence of communication forums established for the sole purpose of giving support to members facing significant health or psychological problems several high profile cases have demonstrated behavior patterns which are common among those who pose as gravely ill or as victims of violence or whose deaths are announced to online forums the virtual communities that were created to give support as well as general non medical communities often express genuine sympathy and grief for the purported victims when fabrications are suspected or confirmed the ensuing discussion can create schisms in online communities destroying some and altering the trusting nature of individual members in others
münchausen syndrome is a psychiatric factitious disorder wherein those affected feign disease illness or psychological trauma to draw attention sympathy or reassurance to themselves munchausen syndrome fits within the subclass of factitious disorder with predominantly physical signs and symptoms but patients also have a history of recurrent hospitalization travelling and dramatic extremely improbable tales of their past experiences the condition derives its name from the fictional character baron munchausen there is discussion to reclassify them as somatoform disorders in the dsm 5 as it is unclear whether or not people are conscious of drawing attention to themselves in the current iteration the term somatoform disorder as used in the dsm iv tr and other literature is no longer in use that particular section of the dsm 5 has been renamed somatic symptom and related disorders officially munchausen syndrome has been renamed factitious disorder with specificity either as imposed on self or imposed on another formerly by proxy munchausen syndrome is related to munchausen syndrome by proxy msbp msp which refers to the abuse of another person typically a child in order to seek attention or sympathy for the abuser this drive to create symptoms for the victim can result in unnecessary and costly diagnostic or corrective procedures
munchausen syndrome by proxy msbp or mbp is a behavior pattern akin to munchausen syndrome a psychiatric factitious disorder wherein those affected feign disease illness or psychological trauma to draw attention sympathy or reassurance to themselves in which a caregiver or spouse fabricates exaggerates or induces mental or physical health problems in those who are in their care usually to gain attention or sympathy from others with deception at its core this behavior is an elusive potentially lethal and frequently misunderstood form of child abuse or medical neglect that has been difficult to define detect and confirm msbp has also spawned much heated controversy within the legal and social services communities in a handful of high profile cases mothers who have had several children die from sudden infant death syndrome have been declared to have msbp based on msbp testimony of an expert witness they were tried for murder convicted and imprisoned for several years in some cases that testimony was later impeached resulting in exoneration of those defendants
munro s microabscess is an abscess collection of neutrophils in the stratum corneum of the epidermis due to the infiltration of neutrophils from papillary dermis into the epidermal stratum corneum they are a cardinal sign of psoriasis where they are seen in the hyperkeratotic and parakeratotic areas of the stratum corneum munro microabscesses are not seen in seborrheic dermatitis it is named for william john munro
denise amber lee was murdered by michael king in the u s state of florida on january 17 2008 after he had kidnapped and raped her earlier in the day lee and several others had attempted to call for help through the 9 1 1 system but there was a lack of communication and the police and other emergency services arrived too late five 9 1 1 calls were made that day including one by lee herself from her abductor s phone and one from a witness jane kowalski who gave a detailed account of events as they unfolded before her failures were later found in the way the 9 1 1 operators handled kowalski s call and further failures were later identified nationwide in the 9 1 1 system king was sentenced to death the denise amber lee act was passed unanimously by the florida legislature on april 24 2008 this act provides for voluntary training for 9 1 1 operatives lee s family continue to lobby for a new law to be passed which would institute mandatory training and certification for all 9 1 1 dispatchers the denise amber lee foundation was established in june 2008 to promote such training as well as to raise public awareness of the issues involved
murine typhus also called endemic typhus is a form of typhus transmitted by fleas xenopsylla cheopis usually on rats this is in contrast to epidemic typhus which is usually transmitted by lice murine typhus is an under recognized entity as it is often confused with viral illnesses most people who are infected do not realize that they have been bitten by fleas
murmurhash is a non cryptographic hash function that was used for hash based lookups due to possible denial of service attacks it should no longer be used for this purpose it was created by austin appleby in 2008 and is currently hosted on github along with its test suite named smhasher it also exists in a number of variants all of which have been released into the public domain the name comes from two basic operations multiply mu and rotate r used in its inner loop unlike cryptographic hash functions it is not specifically designed to be difficult to reverse by an adversary making it unsuitable for cryptographic purposes
muscardine is a disease of insects it is caused by many species of entomopathogenic fungus many muscardines are known for affecting silkworms muscardine may also be called calcino while studying muscardine in silkworms in the 19 th century agostino bassi found that the causal agent was a fungus this was the first demonstration of the germ theory of disease the first time a microorganism was recognized as an animal pathogen there are many types of muscardine they are often named for the color of the conidial layer each fungus leaves on its host
muscle atrophy is defined as a decrease in the mass of the muscle it can be a partial or complete wasting away of muscle and is most commonly experienced when persons suffer temporary disabling circumstances such as being restricted in movement and or confined to bed as when hospitalized when a muscle atrophies this leads to muscle weakness since the ability to exert force is related to mass modern medicine s understanding of the quick onset of muscle atrophy is a major factor behind the practice of getting hospitalized patients out of bed and moving about as active as possible as soon as is feasible despite sutures wounds broken bones and pain muscle atrophy results from a co morbidity of several common diseases including cancer aids congestive heart failure copd chronic obstructive pulmonary disease renal failure and severe burns patients who have cachexia in these disease settings have a poor prognosis moreover starvation eventually leads to muscle atrophy disuse of the muscles such as when muscle tissue is immobilized for even a few days of unuse – when the patient has a primary injury such as an immobilized broken bone set in a cast or immobilized in traction for example – will also lead rapidly to disuse atrophy minimizing such occurrences as soon as possible is a primary mission of occupational and physical therapists employed within hospitals working in co ordination with orthopedic surgeons neurogenic atrophy which has a similar effect is muscle atrophy resulting from damage to the nerve which stimulates the muscle causing a shriveling around otherwise healthy limbs also time in a circa zero g environment without exercise will lead to atrophy this is partially due to the smaller amount of exertion needed to move about and the fact that muscles are not used to maintain posture in a similar effect patients with a broken leg joint undergoing as little as three weeks of traction can lose enough back and buttocks muscle mass and strength as to have difficulty sitting without assistance and experience pain stress and burning even after a very short ten minute exposure when such positioning is contrived during recovery
muscle coactivation is a phenomenon in which a muscle is activated coordinately with another muscle the emg shown demonstrates the antagonistic muscle activity in the biceps and triceps of a relaxed and seated subject with the elbow bent at 90 degrees increase in the activity of the triceps likewise there is a minor increase of activity in the biceps trace when the triceps is activated coactivation of the muscles stabilizes a joint although the mechanism is not well understood muscular coactivation is thought to be required for fine movements
muscle dysmorphia sometimes called bigorexia megarexia or reverse anorexia is a subtype of body dysmorphic disorder but is often also grouped with eating disorders affecting mostly males and many athletes muscle dysmorphia is obsessive preoccupation via delusional or exaggerated belief that one s own body is too small too skinny insufficiently muscular or insufficiently lean although in most cases the individual s build is normal or even exceptionally large and muscular already disordered fixation on gaining body mass as by devoting inordinate time and attention on exercise routines dietary regimens and nutritional supplements is typical and use of anabolic steroids is common usually also present are other body dysmorphic preoccupations that are not muscle dysmorphic muscle dysmorphia has also been called the adonis complex which however encompasses broader concerns of male body image yet likewise muscle dysmorphia s rising incidence is due in part to recent popularization of extreme cultural ideals of men s bodies severely distressful and distracting muscle dysmorphia s bodily concerns provoke absences from school work and socializing perceiving one s body as severely undesirable one may avoid dating versus other body dysmorphic disorder rates of suicide attempts may be especially high although likened to anorexia nervosa in females muscle dysmorphia is mostly unknown and tough to recognize especially since males experiencing it typically look healthy to others by some estimates 10 of gym going men experience muscle dysmorphia
muscle fatigue is the decline in ability of a muscle to generate force it can be a result of vigorous exercise but abnormal fatigue may be caused by barriers to or interference with the different stages of muscle contraction there are two main causes of muscle fatigue the limitations of a nerve ’ s ability to generate a sustained signal neural fatigue and the reduced ability of the muscle fiber to contract metabolic fatigue
an muscle tissue neoplasm is a neoplasm derived from muscle an example is myoma
muscle weakness or myasthenia my from greek μυο meaning muscle asthenia ἀσθένεια meaning weakness is a lack of muscle strength the causes are many and can be divided into conditions that have either true or perceived muscle weakness true muscle weakness is a primary symptom of a variety of skeletal muscle diseases including muscular dystrophy and inflammatory myopathy it occurs in neuromuscular junction disorders such as myasthenia gravis muscle weakness can also be caused by low levels of potassium and other electrolytes within muscle cells it can be temporary or long lasting from seconds or minutes to months or years
muscular dystrophy md is a group of muscle diseases that results in increasing weakening and breakdown of skeletal muscles over time the disorders differ in which muscles are primarily affected the degree of weakness how fast they worsen and when symptoms begin many people eventually become unable to walk some types are also associated with problems in other organs there are nine main categories of muscular dystrophy that contain more than thirty specific types the most common type is duchenne muscular dystrophy dmd which typically affects males beginning around the age of four other types include becker muscular dystrophy facioscapulohumeral muscular dystrophy and myotonic dystrophy they are due to mutations in genes that are involved in making muscle proteins this can occur due to either inheriting the defect from one s parents or the mutation occurring during early development disorders may be x linked recessive autosomal recessive or autosomal dominant diagnosis often involves blood tests and genetic testing there is no cure for muscular dystrophy physical therapy braces and corrective surgery may help with some symptoms assisted ventilation may be required in those with weakness of breathing muscles medications used include steroids to slow muscle degeneration anticonvulsants to control seizures and some muscle activity and immunosuppressants to delay damage to dying muscle cells outcomes depend on the specific type of disorder duchenne muscular dystrophy which represents about half of all cases of muscular dystrophy affects about one in 5 000 males at birth muscular dystrophy was first described in the 1830 s by charles bell the word dystrophy is from the greek dys meaning difficult and troph meaning nourish gene therapy as a treatment is in the early stages of study in humans
a musculoskeletal abnormality is a disorder of the musculoskeletal system present at birth they can be due to deformity or malformation an example is klippel feil syndrome although present at birth some only become obvious postnatally
musculoskeletal disorders msds are injuries or pain in the body s joints ligaments muscles nerves tendons and structures that support limbs neck and back msds can arise from a sudden exertion e g lifting a heavy object or they can arise from making the same motions repeatedly repetitive strain or from repeated exposure to force vibration or awkward posture injuries and pain in the musculoskeletal system caused by acute traumatic events like a car accident or fall are not considered musculoskeletal disorders msds can affect many different parts of the body including upper and lower back neck shoulders and extremities arms legs feet and hands examples of msds include carpal tunnel syndrome epicondylitis tendinitis back pain tension neck syndrome and hand arm vibration syndrome
mushroom poisoning also known as mycetism or mycetismus refers to harmful effects from ingestion of toxic substances present in a mushroom these symptoms can vary from slight gastrointestinal discomfort to death the toxins present are secondary metabolites produced in specific biochemical pathways in the fungal cells mushroom poisoning is usually the result of ingestion of wild mushrooms after misidentification of a toxic mushroom as an edible species the most common reason for this misidentification is close resemblance in terms of colour and general morphology of the toxic mushrooms species with edible species to prevent mushroom poisoning mushroom gatherers need to be very familiar with the mushrooms they intend to collect as well as with any similar looking toxic species in addition edibility of mushrooms may depend on methods of preparation for cooking collectors also need to be well aware that edibility or toxicity of some species varies with geographic location
music of canadian cultures is a wide and diverse accumulation of music from many different individual communities all across canada with canada being vast in size the country throughout its history has had regional music scenes the music of canada has reflected the multi cultural influences that have shaped the country first nations people the french the british the united states and many others nationalities have all made unique contributions to the musical heritage of canada
musical technique is the ability of instrumental and vocal musicians to exert optimal control of their instruments or vocal cords in order to produce the precise musical effects they desire improving one s technique generally entails practicing exercises that improve one s muscular sensitivity and agility technique is independent of musicality to improve their technique musicians often practice fundamental patterns of notes such as the natural minor major and chromatic scales minor and major triads dominant and diminished sevenths formula patterns and arpeggios for example triads and sevenths teach how to play chords with accuracy and speed scales teach how to move quickly and gracefully from one note to another usually by step arpeggios teach how to play broken chords over larger intervals many of these components of music are found in difficult compositions for example a large tuple chromatic scale is a very common element to classical and romantic era compositions as part of the end of a phrase heinrich schenker argued that musical technique s most striking and distinctive characteristic is repetition works known as études meaning study are also frequently used for the improvement of technique
musth or must ˈmʌst urdu مست is a periodic condition in bull male elephants characterized by highly aggressive behavior and accompanied by a large rise in reproductive hormones testosterone levels in an elephant in musth can be as much as 60 times greater than in the same elephant at other times however whether this hormonal surge is the sole cause of musth or merely a contributing factor is unknown scientific investigation of musth is problematic because even the most placid elephants become highly violent toward humans and other elephants during musth
in biology a mutation is the permanent alteration of the nucleotide sequence of the genome of an organism virus or extrachromosomal dna or other genetic elements mutations result from errors during dna replication or other types of damage to dna which then may undergo error prone repair especially microhomology mediated end joining or cause an error during other forms of repair or else may cause an error during replication translesion synthesis mutations may also result from insertion or deletion of segments of dna due to mobile genetic elements mutations may or may not produce discernible changes in the observable characteristics phenotype of an organism mutations play a part in both normal and abnormal biological processes including evolution cancer and the development of the immune system including junctional diversity the genomes of rna viruses are based on rna rather than dna the rna viral genome can be double stranded as in dna or single stranded in some of these viruses such as the single stranded human immunodeficiency virus replication occurs quickly and there are no mechanisms to check the genome for accuracy this error prone process often results in mutations mutation can result in many different types of change in sequences mutations in genes can either have no effect alter the product of a gene or prevent the gene from functioning properly or completely mutations can also occur in nongenic regions one study on genetic variations between different species of drosophila suggests that if a mutation changes a protein produced by a gene the result is likely to be harmful with an estimated 70 percent of amino acid polymorphisms that have damaging effects and the remainder being either neutral or marginally beneficial due to the damaging effects that mutations can have on genes organisms have mechanisms such as dna repair to prevent or correct mutations by reverting the mutated sequence back to its original state
mutational meltdown not to be confused with the concept of an error catastrophe is the accumulation of harmful mutations in a small population which leads to loss of fitness and decline of the population size which may lead to further accumulation of deleterious mutations due to fixation by genetic drift a population experiencing mutational meltdown is trapped in a downward spiral and will go extinct if the phenomenon lasts for some time usually the deleterious mutations would simply be selected away but during mutational meltdown the number of individuals thus suffering an early death is too large relative to overall population size so that mortality exceeds the birth rate the accumulation of mutations in small populations can be divided into three phases in the second phase a population starts in mutation selection equilibrium mutations are fixed at a constant rate through time and the population size is constant because the fecundity exceeds mortality however after a sufficient number of mutations have been fixed in the population the birth rate is slightly less than the death rate and the population size begins to decrease the smaller population size allows for a more rapid fixation of deleterious mutations and a more rapid decline of population size etc
mute english is a phenomenon especially common in the people s republic of china where people can read and understand english as a second language but cannot speak it well the phrase is a calque of the chinese phrase 哑巴英语 yǎbā yīngyǔ in pinyin the phenomenon is sometimes referred to as dumb english mute english occurs primarily due to the lack of native english speakers to emulate or practice with particularly in a country as large as china efforts to mitigate mute english in china have resulted in numerous commercial products including tefl schools and teach yourself courses international exchanges and the eagerness with which chinese students strive to practice their english with foreign visitors though any language can have its form of mute speakers e g mute polish the phenomenon of mute english in china is a massive acknowledged problem one which the school systems and students are attempting to address a related concept is the less common deaf english
the my way killings are a social phenomenon in the philippines referring to a number of fatal disputes which arose due to the singing of the song my way popularized by frank sinatra peaking at 27 on billboard hot 100 in 1969 in karaoke bars a new york times article estimates the number of killings to be about six up to 2010 another source estimates at least 12 between 2002 – 2012 opinions differ over whether the possible connection is due to the coincidence that the song was simply frequently sung amid the nation s karaoke bars where violence is common or to the aggressive lyrics of the song itself
myalgia or muscle pain is a symptom of many diseases and disorders the most common causes are the overuse or over stretching of a muscle or group of muscles myalgia without a traumatic history is often due to viral infections longer term myalgias may be indicative of a metabolic myopathy some nutritional deficiencies or chronic fatigue syndrome
myasthenia gravis mg is a long term neuromuscular disease that leads to varying degrees of muscle weakness the most commonly affected muscles are those of the eyes face and swallowing it can result in double vision drooping eyelids trouble talking and trouble walking onset can be sudden those affected often have a large thymus gland or develop a thymoma myasthenia gravis is an autoimmune disease which results from antibodies that block acetylcholine receptors at the junction between the nerve and muscle this prevents nerve impulses from triggering muscle contractions rarely an inherited genetic defect in the neuromuscular junction results in a similar condition known as congenital myasthenia babies of mothers with myasthenia may have symptoms during their first few months of life known as neonatal myasthenia diagnosis can be supported by blood tests for specific antibodies the edrophonium test or nerve conduction studies myasthenia gravis is generally treated with medications known as acetylcholinesterase inhibitors such as neostigmine and pyridostigmine immunosuppressants such as prednisone or azathioprine may also be used the surgical removal of the thymus gland may improve symptoms in certain cases plasmapheresis and high dose intravenous immunoglobulin may be used during sudden flares of the condition if the breathing muscles become significantly weak mechanical ventilation may be required myasthenia gravis affects 50 to 200 per million people it is newly diagnosed in 3 to 30 per million people each year diagnosis is becoming more common due to increased awareness it most commonly occurs in women under the age of 40 and in men over the age of 60 it is uncommon in children with treatment most of those affected lead relatively normal lives and have a normal life expectancy the word is from the greek μύς muscle and asthenia weakness and the latin gravis serious
mycobacterium avium intracellulare infection mai is an atypical mycobacterial infection i e one with nontuberculous mycobacteria or ntm caused by mycobacterium avium complex this infection causes respiratory illness in birds pigs and humans especially in immunocompromised people in the later stages of aids it can be very severe it usually first presents as a persistent cough it is typically treated with a series of three antibiotics for a period of at least six months mycobacterium avium and m intracellulare the m a complex or mac are saprotrophic organisms present in soil and water entry into hosts is usually via the gastrointestinal tract but also can be via the lungs mac can cause fevers diarrhea malabsorption as well as loss of appetite and weight loss and can disseminate to the bone marrow therapy for mai is typically resistant to standard mycobacterial therapies
micoplasma hominis infection is caused by the bacteria mycoplasma hominis micoplasma hominis infection is spread through vaginal intercourse oral to genital contact and vertically from mother to her infant in utero or by the colonization by the bacteria as the baby descends through the birth canal or by nosocomial acquisition through transplanted tissues it is not present in the normal vaginal microbiota it can also be present in bacterial vaginosis
mycoplasma pneumonia also known as walking pneumonia because its patients can sometimes continue to walk about while suffering from its symptoms is a form of bacterial pneumonia caused by the bacterial species mycoplasma pneumoniae
soil carbon storage is an important function of terrestrial ecosystems soil contains more carbon than plants and the atmosphere combined understanding what maintains the soil carbon pool is important to understand the current distribution of carbon on earth and how it will respond to environmental change while much research has been done on how plants free living microbial decomposers and soil minerals affect this pool of carbon it is recently coming to light that mycorrhizal fungi — symbiotic fungi that associate with roots of almost all living plants — may play an important role in maintaining this pool as well measurements of plant carbon allocation to mycorrhizal fungi have been estimated to be 5 20 of total plant carbon uptake and in some ecosystems the biomass of mycorrhizal fungi can be comparable to the biomass of fine roots recent research has shown that mycorrhizal fungi hold 50 to 70 percent of the total carbon stored in leaf litter and soil on forested islands in sweden turnover of mycorrhizal biomass into the soil carbon pool is thought to be rapid and has been shown in some ecosystems to be the dominant pathway by which living carbon enters the soil carbon pool outlined below are the leading lines of evidence on how different aspects of mycorrhizal fungi may alter soil carbon decomposition and storage evidence is presented for arbuscular and ectomycorrhizal fungi separately as they are phylogenetically distinct and often function in very different ways
mycosis plural mycoses is a fungal infection of animals including humans mycoses are common and a variety of environmental and physiological conditions can contribute to the development of fungal diseases inhalation of fungal spores or localized colonization of the skin may initiate persistent infections therefore mycoses often start in the lungs or on the skin fungal infections of the skin was the 4 th most common disease in 2010 affecting 984 million people
mycosis fungoides also known as alibert bazin syndrome or granuloma fungoides is the most common form of cutaneous t cell lymphoma it generally affects the skin but may progress internally over time symptoms include rash tumors skin lesions and itchy skin while the cause remains unclear most cases are not hereditary most cases are in people over 20 years of age and it is more common in men than women treatment options include sunlight exposure ultraviolet light topical corticosteroids chemotherapy and radiotherapy
an infected aneurysm also known as mycotic aneurysm or microbial arteritis is an aneurysm arising from bacterial infection of the arterial wall it can be a common complication of the hematogenous spread of bacterial infection william osler first used the term mycotic aneurysm in 1885 to describe a mushroom shaped aneurysm in a patient with subacute bacterial endocarditis this may create considerable confusion since mycotic is typically used to define fungal infections however mycotic aneurysm is still used for all extracardiac or intracardiac aneurysms caused by infections except for syphilitic aortitis the term infected aneurysm proposed by jarrett and associates is more appropriate since few infections involve fungi according to some authors a more accurate term might have been endovascular infection or infective vasculitis because mycotic aneurysms are not due to a fungal organism mycotic aneurysms account for 2 6 of aortic aneurysms for the clinician early diagnosis is the cornerstone of effective treatment without medical or surgical management catastrophic hemorrhage or uncontrolled sepsis may occur however symptomatology is frequently nonspecific during the early stages so a high index of suspicion is required to make the diagnosis intracranial mycotic aneurysms icmas complicate about 2 to 3 of infective endocarditis ie cases although as many as 15 to 29 of patients with ie have neurologic symptoms
mydriasis mᵻˈdraɪ əsɪs is the dilation of the pupil usually defined as when having a non physiological cause but sometimes defined as potentially being a physiological pupillary response non physiological causes of mydriasis include disease trauma or the use of drugs normally as part of the pupillary light reflex the pupil dilates in the dark and constricts in the light to respectively improve vividity at night and to protect the retina from sunlight damage during the day a mydriatic pupil will remain excessively large even in a bright environment the excitation of the radial fibres of the iris which increases the pupillary aperture is referred to as a mydriasis more generally mydriasis also refers to the natural dilation of pupils for instance in low light conditions or under sympathetic stimulation an informal term for mydriasis is blown pupil and is used by medical providers it is usually used to refer to a fixed unilateral mydriasis which could be a symptom of raised intracranial pressure the opposite constriction of the pupil is referred to as miosis both mydriasis and miosis can be physiological anisocoria is the condition of one pupil being more dilated than the other
myelitis involves the infection or the inflammation of the white matter or gray matter of the spinal cord which is a part of central nervous system that acts as a bridge between the brain and the rest of the body during an inflammatory response in the spinal cord the myelin and axon may be damaged causing symptoms such as paralysis and sensory loss myelitis is classified to several categories depending on the area or the cause of the lesion however people often refer to any inflammatory attack on the spinal cord as transverse myelitis
the myelodysplastic syndromes also known as mds or myelodysplasia are hematological i e blood related medical conditions that cause ineffective production or dysplasia of all blood cells patients with mds can develop severe anemia and require blood transfusions in some cases the disease worsens and the patient develops cytopenias low blood counts caused by progressive bone marrow failure the outlook in mds depends on the type and severity many people live normal lifespans with mds the myelodysplastic syndromes are all disorders of the hematopoietic stem cells in the bone marrow only related to myeloid lineage in mds hematopoiesis i e blood production is disorderly and ineffective the number and quality of blood forming cells decline irreversibly further impairing blood production the mean age of onset of mds is 68 years
myelofibrosis also known as osteomyelofibrosis is a relatively rare bone marrow cancer it is currently classified as a myeloproliferative neoplasm in which the proliferation of an abnormal clone of hematopoietic stem cells in the bone marrow and other sites results in fibrosis or the replacement of the marrow with scar tissue the term myelofibrosis alone usually refers to primary myelofibrosis pmf also known as chronic idiopathic myelofibrosis cimf the terms idiopathic and primary mean that in these cases the disease is of unknown or spontaneous origin this is in contrast with myelofibrosis that develops secondary to polycythemia vera or essential thrombocythaemia myelofibrosis is a form of myeloid metaplasia which refers to a change in cell type in the blood forming tissue of the bone marrow and often the two terms are used synonymously the terms agnogenic myeloid metaplasia and myelofibrosis with myeloid metaplasia mmm are also used to refer to primary myelofibrosis
myeloid leukemia is a type of leukemia affecting myeloid tissue types include acute myeloid leukemia chronic myelogenous leukemia
a myeloid sarcoma chloroma granulocytic sarcoma extramedullary myeloid tumor is a solid tumor composed of immature white blood cells called myeloblasts a chloroma is an extramedullary manifestation of acute myeloid leukemia in other words it is a solid collection of leukemic cells occurring outside of the bone marrow
myelokathexis is a congenital disorder of the white blood cells that causes severe chronic leukopenia a reduction of circulating white blood cells and neutropenia a reduction of neutrophil granulocytes the disorder is believed to be inherited in an autosomal dominant manner myelokathexis refers to retention kathexis of neutrophils in the bone marrow myelo
myelolipoma myelo from the ancient greek μυελός marrow lipo meaning of or pertaining to fat oma meaning tumor or mass is a benign tumor like lesion composed of mature adipose fat tissue and haematopoietic blood forming elements in various proportions myelolipomas can present in the adrenal gland or outside of the gland
myeloma cast nephropathy also cast nephropathy is the formation of plugs urinary casts in the renal tubules from free immunoglobulin light chains leading to renal failure in the context of multiple myeloma
myelopathy describes any neurologic deficit related to the spinal cord when due to trauma it is known as acute spinal cord injury when inflammatory it is known as myelitis disease that is vascular in nature is known as vascular myelopathy the most common form of myelopathy in human cervical spondylotic myelopathy csm is caused by arthritic changes spondylosis of the cervical spine which result in narrowing of the spinal canal spinal stenosis ultimately causing compression of the spinal cord in asian populations spinal cord compression often occurs due to a different inflammatory process affecting the posterior longitudinal ligament clinical signs and symptoms depend on which spinal cord level cervical thoracic or lumbar is affected and the extent anterior posterior or lateral of the pathology and may include upper motor neuron signs weakness spasticity clumsiness altered tonus hyperreflexia and pathological reflexes including hoffmann s sign and inverted plantar reflex positive babinski sign lower motor neuron signs weakness clumsiness in the muscle group innervated at the level of spinal cord compromise muscle atrophy hyporeflexia muscle hypotonicity or flaccidity fasciculations sensory deficits bowel bladder symptoms and sexual dysfunction
myeloperoxidase deficiency is an autosomal recessive genetic disorder featuring deficiency either in quantity or of function of myeloperoxidase an enzyme found in certain phagocytic immune cells especially polymorphonuclear leukocytes it can appear similar to chronic granulomatous disease on some screening tests
myelophthisic anemia or myelophthisis is a severe kind of anemia found in some people with diseases that affect the bone marrow myelophthisis refers to the displacement of hemopoietic bone marrow tissue either by fibrosis tumors or granulomas
the myeloproliferative neoplasms mpns previously myeloproliferative diseases mpds are a group of diseases of the bone marrow in which excess cells are produced they are related to and may evolve into myelodysplastic syndrome and acute myeloid leukemia although the myeloproliferative diseases on the whole have a much better prognosis than these conditions the concept of myeloproliferative disease was first proposed in 1951 by the hematologist william dameshek in the most recent world health organization classification of hematologic malignancies this group of diseases was renamed from myeloproliferative diseases to myeloproliferative neoplasms this reflects the underlying clonal genetic changes that are a salient feature of this group of disease the increased numbers of blood cells may not cause any symptoms but a number of medical problems or symptoms may occur the risk of thrombosis is increased in some types of mpn
myerson s sign or glabellar tap sign is a medical condition where a patient is unable to resist blinking when tapped on the glabella the area above the nose and between the eyebrows it is often referred to as the glabellar reflex it is often an early symptom of parkinson s disease but can also be seen in early dementia as well as other progressive neurologic illness it is named for abraham myerson an american neurologist
myhre syndrome is a rare genetic disorder
myiasis ˈmaɪ əsᵻs or maɪˈaɪ əsᵻs is the parasitic infestation of the body of a live mammal by fly larvae maggots that grow inside the host while feeding on its tissue although flies are most commonly attracted to open wounds and urine or feces soaked fur some species including the most common myiatic flies the botfly blowfly and screwfly can create an infestation even on unbroken skin and have been known to use moist soil and non myiatic flies such as the common housefly as vector agents for their parasitic larvae colloquialisms for myiasis include flystrike and blowfly strike and the victim or the tissue may be described as fly blown the name of the condition derives from ancient greek μυῖα myia meaning fly because some animals particularly domestic animals cannot react as effectively as humans to the causes and effects of myiasis such infestations present a severe and continuing problem for livestock industries worldwide causing severe economic losses where they are not mitigated by human action although typically a far greater issue for animals myiasis is also a relatively frequent affliction of humans in rural tropical regions where myiatic flies thrive and often may require medical attention to surgically remove the parasites myiasis varies widely in the forms it takes and its effects on the victims such variations depend largely on the fly species and where the larvae are located some flies lay eggs in open wounds other larvae may invade unbroken skin or enter the body through the nose or ears and still others may be swallowed if the eggs are deposited on the lips or on food
a myocardial contusion is a term for a bruise contusion to the heart after an injury it is usually a consequence of blunt trauma to the anterior chest wall and the right ventricle is thought to be most commonly affected due to its anatomic location as the most anterior surface of the heart myocardial contusion is not a specific diagnosis and the extent of the injury can vary greatly usually there are other chest injuries seen with a myocardial contusion such as rib fractures pneuomothorax and valve injury when a myocardial contusion is suspected consideration must be given to any other chest injuries which will likely be determined by clinical signs tests and imaging the signs and symptoms of a myocardial contusion can manifest in different ways in people which may also be masked by the other injuries they present with it is recommended that people with blunt chest trauma receive an electrocardiogram to determine if there are any irregularities with cardiac function the presentation of a dysrhythmia after sustaining a myocardial contusion can be delayed for up to 72 hours
myocardial infarction mi or acute myocardial infarction ami commonly known as a heart attack occurs when blood flow stops to a part of the heart causing damage to the heart muscle the most common symptom is chest pain or discomfort which may travel into the shoulder arm back neck or jaw often it is in the center or left side of the chest and lasts for more than a few minutes the discomfort may occasionally feel like heartburn other symptoms may include shortness of breath nausea feeling faint a cold sweat or feeling tired about 30 of people have atypical symptoms with women more likely than men to present atypically among those over 75 years old about 5 have had an mi with little or no history of symptoms an mi may cause heart failure an irregular heartbeat or cardiac arrest most mis occur due to coronary artery disease risk factors include high blood pressure smoking diabetes lack of exercise obesity high blood cholesterol poor diet and excessive alcohol intake among others the mechanism of an mi often involves the complete blockage of a coronary artery caused by a rupture of an atherosclerotic plaque mis are less commonly caused by coronary artery spasms which may be due to cocaine significant emotional stress and extreme cold among others a number of tests are useful to help with diagnosis including electrocardiograms ecgs blood tests and coronary angiography an ecg may confirm an st elevation mi if st elevation is present commonly used blood tests include troponin and less often creatine kinase mb aspirin is an appropriate immediate treatment for a suspected mi nitroglycerin or opioids may be used to help with chest pain however they do not improve overall outcomes supplemental oxygen should be used in those with low oxygen levels or shortness of breath in st elevation mis treatments which attempt to restore blood flow to the heart are typically recommended and include angioplasty where the arteries are pushed open or thrombolysis where the blockage is removed using medications people who have a non st elevation myocardial infarction nstemi are often managed with the blood thinner heparin with the additional use of angioplasty in those at high risk in people with blockages of multiple coronary arteries and diabetes bypass surgery cabg may be recommended rather than angioplasty after an mi lifestyle modifications along with long term treatment with aspirin beta blockers and statins are typically recommended worldwide about 8 6 million myocardial infarctions occurred in 2013 more than 3 million people had an st elevation mi and more than 4 million had an nstemi stemis occur about twice as often in men as women about one million people have an mi each year in the united states in the developed world the risk of death in those who have had an stemi is about 10 rates of mi for a given age have decreased globally between 1990 and 2010
myocardial rupture is a laceration or tearing of the wall of the ventricles or atria of the heart of the interatrial or interventricular septum or of the papillary muscles it is most commonly seen as a serious sequela of an acute myocardial infarction heart attack it can also be caused by trauma
in cardiology stunned myocardium is a state when some section of the myocardium corresponding to area of a major coronary occlusion shows a form of contractile abnormality this is a segmental dysfunction which persists for a variable period of time about two weeks even after ischemia has been relieved by for instance angioplasty or coronary artery bypass surgery in this situation while myocardial blood flow mbf returns to normal function is still depressed for a variable period of time myocardial stunning is the reversible reduction of function of heart contraction after reperfusion not accounted for by tissue damage or reduced blood flow after total ischemia occurs the myocardium switches immediately from aerobic glycolysis to anaerobic glycolysis resulting in the reduced ability to produce high energy phosphates such as atp and creatinine phosphate at this point the lack of the energy and lactate accumulation results in cessation of contraction within 60 seconds of ischemia i e vessel occlusion subsequent to this is a period of myocardial stunning in which reversible ischemic damage is taking place at approximately 30 minutes after the onset of total ischemia the damage becomes irreversible thereby ending the phase of myocardial stunning clinical situations of stunned myocardium are acute myocardial infarction ami after percutaneous transluminal coronary angioplasty ptca after cardiac surgery neurogenic stunned myocardium following an acute cerebrovascular event such as a subarachnoid hemorrhage
there are multiple originations for myocardiodystrophy alcohol intoxication can originate the creation of it along with making it worse if consumption continues over a long period of time different types of obesity can also originate the disease along with other endocrine diseases infections and various types of neurological pathologies
myocarditis also known as inflammatory cardiomyopathy is inflammation of the heart muscle the consequences of myocarditis vary widely it can cause a mild disease without any symptoms that resolves itself or it may cause chest pain heart failure or sudden death an acute myocardial infarction like syndrome with normal coronary arteries has a good prognosis heart failure even with a dilated left ventricle may have a good prognosis ventricular arrhythmias and high degree heart block have a poor prognosis loss of right ventricular function is a strong predictor of death myocarditis is most often due to an infection by common viruses such as parvovirus b 19 less commonly nonviral infections such as lyme disease or trypanosoma cruzi or as a hypersensitivity response to drugs may be the cause myocarditis can sometimes be an autoimmune disease streptococcal m protein and coxsackievirus b have regions that are similar to the myosin protein found in the heart muscle during and after the infection the immune system may attack cardiac myosin myocarditis may include death of heart tissue it may include dilated cardiomyopathy a definitive diagnosis requires a heart biopsy in 2013 about 1 5 million cases of acute myocarditis occurred cardiomyopathy including myocarditis resulted in 443 000 deaths in 2013 up from 294 000 in 1990
myoclonic astatic epilepsy also known as doose syndrome is a generalized idiopathic epilepsy it is characterized by the development of myoclonic seizures and or myoclonic astatic seizures
myoclonic dystonia or myoclonus dystonia syndrome is a rare movement disorder that induces spontaneous muscle contraction causing abnormal posture the prevalence of myoclonus dystonia has not been reported however this disorder falls under the umbrella of movement disorders which affect thousands worldwide myoclonus dystonia results from mutations in the sgce gene coding for an integral membrane protein found in both neurons and muscle fibers those suffering from this disease exhibit symptoms of rapid jerky movements of the upper limbs myoclonus as well as distortion of the body s orientation due to simultaneous activation of agonist and antagonist muscles dystonia myoclonus dystonia is caused by loss of function mutations in the epsilon sarcoglycan gene sgce the disease is dominantly inherited however sgce is an imprinted gene so only the paternal allele is expressed therefore children suffering from this disease inherit the mutation from the father if the mutated allele is inherited from the mother the child is not likely to exhibit symptoms while no cure has been found for myoclonus dystonia treatment options are available to those suffering from the disease ethanol often ameliorates the symptoms well and so the syndrome is also called alcohol responsive dystonia alcohol may be substituted by benzodiazepines such as clonazepam which work through the same mechanism deep brain stimulation dbs is another viable option that can alleviate symptoms without the unwanted side effects of medications and has been successful in treating other movement disorders
myoclonic epilepsy refers to a family of epilepsies that present with myoclonus when myoclonic jerks are occasionally associated with abnormal brain wave activity it can be categorized as myoclonic seizure if the abnormal brain wave activity is persistent and results from ongoing seizures then a diagnosis of myoclonic epilepsy may be considered
myoclonus is a brief involuntary twitching of a muscle or a group of muscles it describes a medical sign and generally is not a diagnosis of a disease these myoclonic twitches jerks or seizures are usually caused by sudden muscle contractions positive myoclonus or brief lapses of contraction negative myoclonus the most common circumstance under which they occur is while falling asleep hypnic jerk myoclonic jerks occur in healthy persons and are experienced occasionally by everyone however when they appear with more persistence and become more widespread they can be a sign of various neurological disorders hiccups are a kind of myoclonic jerk specifically affecting the diaphragm when a spasm is caused by another person it is known as a provoked spasm shuddering attacks in babies fall in this category myoclonic jerks may occur alone or in sequence in a pattern or without pattern they may occur infrequently or many times each minute most often myoclonus is one of several signs in a wide variety of nervous system disorders such as multiple sclerosis parkinson s disease dystonia alzheimer s disease gaucher s disease subacute sclerosing panencephalitis creutzfeldt – jakob disease cjd serotonin toxicity some cases of huntington s disease some forms of epilepsy and occasionally in intracranial hypotension some researchers indicate that jerks persistently may even cause early tremors in almost all instances in which myoclonus is caused by central nervous system disease it is preceded by other symptoms for instance in cjd it is generally a late stage clinical feature that appears after the patient has already started to exhibit gross neurological deficits anatomically myoclonus may originate from lesions of the cortex subcortex or spinal cord the presence of myoclonus above the foramen magnum effectively excludes spinal myoclonus further localisation relies on further investigation with electromyography emg and electroencephalography eeg
myoepithelioma of the head and neck also myoepithelioma is a salivary gland tumour of the head and neck that is usually benign as the name suggests it consists of myoepithelial cells classically they are found in the parotid gland or palate a similar tumor type may be found in the tongue referred to as ectomesenchymal chondromyxoid tumor
myofascial pain syndrome mps also known as chronic myofascial pain cmp is a syndrome characterized by chronic pain in multiple myofascial trigger points knots and fascial connective tissue constrictions it can appear in any body part characteristic features of a myofascial trigger points include focal point tenderness reproduction of pain upon trigger point palpation hardening of the muscle upon trigger point palpation pseudo weakness of the involved muscle referred pain and limited range of motion following approximately 5 seconds of sustained trigger point pressure
myoglobinuria is the presence of myoglobin in the urine usually associated with rhabdomyolysis or muscle destruction myoglobin is present in muscle cells as a reserve of oxygen
myokymia from the greek mŷs muscle kŷm kŷmia something swollen or kŷmos wave is an involuntary spontaneous localised quivering of a few muscles or bundles within a muscle but which are insufficient to move a joint one type is superior oblique myokymia myokymia is commonly used to describe an involuntary eyelid muscle contraction typically involving the lower eyelid or less often the upper eyelid it occurs in normal individuals and typically starts and disappears spontaneously however it can sometimes last up to three weeks since the condition typically resolves itself medical professionals do not consider it to be serious or a cause for concern in contrast facial myokymia is a fine rippling of muscles on one side of the face and may reflect an underlying tumor in the brainstem typically a brainstem glioma loss of myelin in the brainstem associated with multiple sclerosis or in the recovery stage of guillain – barré syndrome an inflammatory polyneuropathy that may affect the facial nerve myokymia in otherwise unrelated body parts may occur in neuromyotonia
myoma is a kind of mesenchymal tumor
myopathy is a muscular disease in which the muscle fibers do not function for any one of many reasons resulting in muscular weakness myopathy simply means muscle disease myo greek μυο muscle pathos pathy greek suffering this meaning implies that the primary defect is within the muscle as opposed to the nerves neuropathies or neurogenic disorders or elsewhere e g the brain etc muscle cramps stiffness and spasm can also be associated with myopathy capture myopathy or shock disease is a little studied condition observed in wild animals such as hares and birds that have been captured or handled the condition is usually lethal and stress has been identified as the single most determining factor exacerbated by muscle exertion muscular disease can be classified as neuromuscular or musculoskeletal in nature some conditions such as myositis can be considered both neuromuscular and musculoskeletal
x linked myopathy with excessive autophagy xmea is a rare childhood onset disease characterized by slow progressive vacuolation and atrophy of skeletal muscle there is no known cardiac or intellectual involvement
myopericytoma also glomangiopericytoma is a rare perivascular soft tissue tumour it is usually benign and typically in the distal extremities it is thought to overlap with myofibroma
a myopic crescent is a moon shaped feature that can develop at the temporal lateral border of disc it rarely occurs at the nasal border of myopic eyes it is primarily caused by atrophic changes that are genetically determined with a minor contribution from stretching due to elongation of the eyeball in myopia that is no longer progressing the crescent may be asymptomatic except for its presence on ocular examination however in high degree myopia it may extend to the upper and lower borders or form a complete ring around the optic disc and form a central scotoma the myopic crescent is commonly seen in pathological axial myopia the condition sometimes described erroneously as myopic choroiditis but myopic crescent is not an inflammatory process and does not run parallel to the degree of myopia it usually tends to occur after mid adult life myopic crescent is often associated with some degree of retinal degeneration and occasionally vitreous degeneration
myosarcoma is a malignant muscle tumor leiomyosarcoma is sarcoma of smooth muscle and rhabdomyosarcoma is sarcoma of striated muscle however the term myosarcoma itself still appears in the literature people with myosarcoma often wake up with the feeling as if they had a cramp during their sleep
myositis is a general term for inflammation of the muscles many such conditions are considered likely to be caused by autoimmune conditions rather than directly due to infection although autoimmune conditions can be activated or exacerbated by infections it is also a documented side effect of the lipid lowering drugs statins and fibrates elevation of creatine kinase in blood is indicative of myositis
myositis ossificans comprises two syndromes characterized by heterotopic ossification calcification of muscle
myospherulosis also known as spherulocytosis is a foreign body type granulomatous reaction to lipid containing material and blood it may be seen in various settings including fat necrosis malignancy e g renal cell carcinoma placement of topical tetracycline in a petrolatum base into a surgical site the resultant histopathologic pattern is most unusual and initially was mistakenly thought to represent a previously undescribed endosporulating fungus
myostatin related muscle hypertrophy or myotonic hypertrophy is a rare genetic condition characterized by reduced body fat and increased skeletal muscle size affected individuals have up to twice the usual amount of muscle mass in their bodies they also tend to have increased muscle strength myostatin related muscle hypertrophy is not known to cause any medical problems and affected individuals are intellectually normal the prevalence of this condition is unknown mutations in the mstn gene cause myostatin related muscle hypertrophy the mstn gene provides instructions for making a protein called myostatin which is active in muscles used for movement skeletal muscles both before and after birth this protein normally restrains muscle growth ensuring that muscles do not grow too large mutations that reduce the production of functional myostatin lead to an overgrowth of muscle tissue myostatin related muscle hypertrophy has a pattern of inheritance known as incomplete autosomal dominance people with a mutation in both copies of the mstn gene in each cell homozygotes have significantly increased muscle mass and strength people with a mutation in one copy of the mstn gene in each cell heterozygotes also have increased muscle bulk but to a lesser degree researchers at guangzhou institutes of biomedicine and health in china have edited the genome of beagles to create double the amount of muscle
myotonia myo from greek muscle and tonus from latin tension is a symptom of a small handful of certain neuromuscular disorders characterized by delayed relaxation prolonged contraction of the skeletal muscles after voluntary contraction or electrical stimulation myotonia is present in myotonia congenita paramyotonia congenita and myotonic dystrophy generally repeated contraction of the muscle can alleviate the myotonia and relax the muscles thus improving the condition however this is not the case in paramyotonia congenita this phenomenon is known as warm up and is not to be confused with warming up before exercise though they may appear similar individuals with the disorder may have trouble releasing their grip on objects or may have difficulty rising from a sitting position and a stiff awkward gait myotonia can affect all muscle groups however the pattern of affected muscles can vary depending on the specific disorder involved people suffering from disorders involving myotonia can have a life threatening reaction to certain anaesthetics one of these conditions occurs when the patient is under anaesthetic and is termed malignant hyperthermia
congenital myotonia also myotonia congenita myo from greek muscle and tonus from latin tension is a genetic neuromuscular channelopathy that affects skeletal muscles muscles used for movement the disease was first described by danish german physician asmus julius thomas thomsen 1815 – 1896 in 1876 who himself suffered from the disease the hallmark of the disease is the failure of initiated contraction to terminate often referred to as delayed relaxation of the muscles myotonia and rigidity symptoms include delayed relaxation of the muscles after voluntary contraction myotonia and may also include stiffness hypertrophy enlargement transient weakness in some mutations and cramping
myotonic dystrophy is a long term genetic disorder that affects muscle function symptoms include gradually worsening muscle loss and weakness often muscle contract and are unable to relax other symptoms may include cataracts intellectual disability and heart conduction problems in men their may be early balding and an inability to have children myotonic dystrophy is an autosomal dominant disorder which is typically inherited from a person s parents there are two main types type 1 dm 1 due to mutations in the dmpk gene and type 2 dm 2 due to mutations in the cnbp gene the disorder generally worsens in each generation a type of dm 1 may be apparent at birth dm 2 is generally milder they are types of muscular dystrophy diagnosis is confirmed by genetic testing there is no cure treatments may include braces or wheelchairs pacemakers and non invasive positive pressure ventilation the medications mexiletine or carbamazepine are occasionally helpful pain if it occurs may be treated with tricyclic antidepressants and nonsteroidal anti inflammatory drugs nsaids myotonic dystrophy affects more than 1 in 8 000 people worldwide while myotonic dystrophy can occur at any age onset is typically in the 20 s and 30 s it is the most common form of muscular dystrophy that begins in adulthood it was first described in 1909 with the underlying cause of type 1 determined in 1992
myringomycosis is a fungal infection of the tympanic membrane it is caused by the presence of the fungus aspergillus nigricans or flavescens
myrmecia is one of the three types of warts that occurs on the skin on the hands and feet palmoplantar it is induced by human papilloma virus type 1 hpv 1 they occur on the palms of the hands soles of the feet and on the sides of the fingers and toes the histology is abundant eosinophilic inclusion bodies associated with hpv 1 e 4 gene products it was studied as far back as 42 b c 37 a d by aulus cornelius celsus
myrmecotrophy is the ability of plants to obtain nutrients from ants a form of mutualism due to this behaviour the invasion of vegetation into harsh environments is promoted the dead remains of insects thrown out by the ants are absorbed by the lenticular warts in myrmecophytes like hydnophytum and myrmecodia myrmecodia uses its lenticular warts to suck nutrients from the insects thrown out by the ants the ants in turn benefit with a secure location to form their colony the pitcher plant nepenthes bicalcarata obtains an estimated 42 of its total foliar nitrogen from ant waste
the square array of the integers 1 through n 2 that is generated when a method for constructing a 4 × 4 magic square is generalized was called a mystic square by joel b wolowelsky and david shakow in their article describing a method for constructing a magic square whose order is a multiple of 4 a 4 × 4 magic square can be constructed by writing out the numbers from 1 to 16 consecutively in a 4 × 4 matrix and then interchanging those numbers on the diagonals that are equidistant from the center figure 1 the sum of each row column and diagonal is 34 the “ magic number ” for a 4 × 4 magic square in general the “ magic number ” for an n × n magic square is n n 2 1 2 file mystic square figure 1 jpg
in the forgotten realms campaign setting of the dungeons dragons fantasy role playing game a mythal is a powerful epic level magical effect
myxedema or myxoedema is a term used synonymously with severe hypothyroidism however the term is also used to describe a dermatological change that can occur in hypothyroidism and some forms of hyperthyroidism in this context myxedema refers to deposition of mucopolysaccharides in the dermis which results in swelling of the affected area one manifestation of myxedema occurring in the lower limb is pretibial myxedema a hallmark of graves disease an autoimmune form of hyperthyroidism myxedema can also occur in hashimoto s thyroiditis and other long standing forms of hypothyroidism the word myxedema originates from μύξα taken from ancient greek to convey mucus or slimy substance and ὁοίδημα for swelling it can also be thought as nonpitting edema in contrast to pitting edema
myxedema coma is a state of decompensated hypothyroidism a person may have lab values identical to a normal hypothyroid state but a stressful event such as an infection myocardial infarction or stroke precipitates the myxedema coma state usually in the elderly primary symptoms of myxedema coma are altered mental status and low body temperature low blood sugar low blood pressure hyponatremia hypercapnia hypoxia slowed heart rate and hypoventilation may also occur myxedema although included in the name is not necessarily seen in myxedema coma
myxoid chondrosarcoma is a type of sarcoma it has been associated with a t 9 22 q 22 q 12 ews chn gene fusion
a myxoid cyst also known as a digital mucous cyst and mucous cyst is a cutaneous condition often characterized by nail plate depression and grooves
myxoid lipoblastoma is a cutaneous condition characterized by excess mucin it resembles myxoid liposarcoma
a myxoid liposarcoma is a malignant adipose tissue neoplasm of myxoid appearance histologically myxoid liposarcomas are the second most common type of liposarcoma representing 30 – 40 of all liposarcomas in the limbs occurring most commonly in the legs particularly the thigh followed by the buttocks retroperitoneum trunk ankle proximal limb girdle head and neck and wrist they occur in the intermuscular fascial planes or deep seated areas they present as a large slow growing painless mass they are associated with a fusion between ddit 3 or chop at 12 q 13 1 q 13 2 and fus or tls at 16 p 11 2 or ews at 22 q 12 2 the specific translocation of fus ddit 3 is t 12 16 q 13 p 11
a myxoid tumor is a connective tissue tumor with a myxoid background composed of clear mucoid substance this tumoral phenotype is shared by many tumoral entities myxomas atrial myxoma odontogenic myxoma cutaneous myxoma intramuscular myxoma myxoid hamartoma aggressive angiomyxoma myxoid leiomyoma chondromyxoid fibroma myxoid neurofibroma nerve sheath myxoma neurothekeoma myxolipoma angiomyofibroblastoma myxoid leiomyosarcoma myxoid liposarcoma lipoblastoma myxofibrosarcoma myxoid cortical adenoma pleomorphic adenoma undifferentiated embryonal sarcoma plexiform angiomyxoid myofibroblastic tumor myxoid plexiform fibrohistiocytic tumor angiomyxolipoma vascular myxolipoma parachordoma acral myxoinflammatory fibroblastic sarcoma
a myxoma new latin from greek muxa for mucus is a myxoid tumor of primitive connective tissue it is the most common primary tumor of the heart in adults but can also occur in other locations
myxomatosis sometimes shortened to myxo or myxy is a disease that affects rabbits and is caused by the myxoma virus it was first observed in uruguay in laboratory rabbits in the late 19 th century it was introduced into australia in 1950 in an attempt to control the rabbit population see rabbits in australia affected rabbits develop skin tumors and in some cases blindness followed by fatigue and fever they usually die within 14 days of contracting the disease the disease is spread by direct contact with an affected animal or by being bitten by fleas or mosquitoes that have fed on an infected rabbit the myxomatosis virus does not replicate in these insect hosts but can be physically carried by an insect s mouthparts i e from an infected rabbit to another susceptible animal due to the potential of insect vector transmission pet rabbits may be susceptible in enzootic areas and vaccination is highly recommended
myxosarcoma is a rare malignant tumor of the heart
ménière s disease md is a disorder of the inner ear that is characterized by episodes of feeling like the world is spinning vertigo ringing in the ears tinnitus hearing loss and a fullness in the ear typically only one ear is affected at least initially however over time both ears may become involved episodes generally last from 20 minutes to a few hours the time between episodes varies the hearing loss and ringing in the ears may become constant over time the cause of ménière s disease is unclear but likely involves both genetic and environmental factors a number of theories exist for why it occurs including constrictions in blood vessels viral infections and autoimmune reactions about 10 of cases run in families symptoms are believed to occur as the result of increased fluid build up in the labyrinth of the inner ear diagnosis is based on the symptoms and frequently a hearing test other conditions that may produce similar symptoms include vestibular migraine and transient ischemic attack there is no cure attacks are often treated with medications to help with the nausea and anxiety measures to prevent attacks are overall poorly supported by the evidence a low salt diet diuretics and corticosteroids may be tried physical therapy may help with balance and counselling may help with anxiety injections into the ear or surgery may also be tried if other measures are not effective but are associated with risks the use of tympanostomy tubes while popular is not supported ménière s disease was first identified in the early 1800 s by prosper ménière it affects between 0 3 and 1 9 per 1 000 people it most often starts in the 40 s to 60 s females are more commonly affected than males after 5 – 15 years the episodes of world spinning generally stop and the person is left with mild loss of balance moderately poor hearing in the affected ear and ringing in their ear
ménétrier disease also known as hypoproteinemic hypertrophic gastropathy named after a french physician pierre eugène ménétrier 1859 – 1935 is a rare acquired premalignant disease of the stomach characterized by massive gastric folds excessive mucous production with resultant protein loss and little or no acid production the disorder is associated with excessive secretion of transforming growth factor alpha tgf α
the classical möbius function μ n is an important multiplicative function in number theory and combinatorics the german mathematician august ferdinand möbius introduced it in 1832 it is a special case of a more general object in combinatorics
möbius syndrome also spelled moebius is an extremely rare congenital neurological disorder which is characterized by facial paralysis and the inability to move the eyes from side to side most people with möbius syndrome are born with complete facial paralysis and cannot close their eyes or form facial expressions limb and chest wall abnormalities sometimes occur with the syndrome people with möbius syndrome have normal intelligence although their lack of facial expression is sometimes incorrectly taken to be due to dullness or unfriendliness it is named for paul julius möbius a neurologist who first described the syndrome in 1888
the mössbauer effect or recoilless nuclear resonance fluorescence is a physical phenomenon discovered by rudolf mössbauer in 1958 it involves the resonant and recoil free emission and absorption of gamma radiation by atomic nuclei bound in a solid its main application is in mössbauer spectroscopy in the mössbauer effect a narrow resonance for nuclear gamma emission and absorption results from the momentum of recoil being delivered to a surrounding crystal lattice rather than to the emitting or absorbing nucleus alone when this occurs no gamma energy is lost to the kinetic energy of recoiling nuclei at either the emitting or absorbing end of a gamma transition emission and absorption occur at the same energy resulting in strong resonant absorption
müllerian agenesis also called mayer rokitansky küster hauser syndrome or mrkh named after august franz josef karl mayer carl freiherr von rokitansky hermann küster and g a hauser is a congenital malformation characterized by a failure of the müllerian duct to develop resulting in a missing uterus and variable degrees of vaginal hypoplasia of its upper portion müllerian agenesis including absence of the uterus cervix and or vagina is the etiology in 15 of cases of primary amenorrhoea
müllerian mimicry is a natural phenomenon in which two or more distasteful species that may or may not be closely related and share one or more common predators have come to mimic each other s warning signals it is named after the german naturalist fritz müller who first proposed the concept in 1878 the phenomenon can be understood by imagining two distasteful species that do not resemble one another and are also prey to a common predator occasionally individuals of the predatory third species will encounter one or the other type of noxious prey and thereafter avoid it predators that avoid only one of the harmful species provide no benefit to individuals of the other species therefore it would be advantageous if the appearances of the two prey species were more similar this is because a predator that learns to avoid either species in a pair of species exhibiting müllerian mimicry learns in effect to avoid both
n acetylglutamate synthase or synthetase deficiency is an autosomal recessive urea cycle disorder
in cryptography n hash is a cryptographic hash function based on the feal round function and is now considered insecure it was proposed in 1990 by miyaguchi et al weaknesses were published the following year n hash has a 128 bit hash size a message is divided into 128 bit blocks and each block is combined with the hash value computed so far using the g compression function g contains eight rounds each of which uses an f function similar to the one used by feal eli biham and adi shamir 1991 applied the technique of differential cryptanalysis to n hash and showed that collisions could be generated faster than by a birthday attack for n hash variants with even up to 12 rounds
in physics the n body problem is the problem of predicting the individual motions of a group of celestial objects interacting with each other gravitationally solving this problem has been motivated by the desire to understand the motions of the sun moon planets and the visible stars in the 20 th century understanding the dynamics of globular cluster star systems became an important n body problem the n body problem in general relativity is considerably more difficult to solve the classical physical problem can be informally stated as given the quasi steady orbital properties instantaneous position velocity and time of a group of celestial bodies predict their interactive forces and consequently predict their true orbital motions for all future times to this purpose the two body problem has been completely solved and is discussed below as is the famous restricted 3 body problem
nasdaq marketsite or simply marketsite is the commercial marketing presence of the nasdaq stock market located in times square in new york city it occupies the northwest corner of the bottom of the condé nast building located at 4 times square the exterior wall of the seven story cylindrical tower is an led electronic video display that provides market quotes financial news and advertisements it was built in 1999 and made its debut on january 1 st 2000 the ground floor of the glass walled marketsite contains a television studio a wall of rear projection monitors 44 feet 17 m long by 14 feet 4 m high display market conditions in real time providing reporters from cnbc cnn yahoo finance fox news channel msnbc bloomberg television bbc and other financial television networks a backdrop to present their reports businessweek s weekly syndicated newsmagazine also comes from the marketsite the technologies and processes used in the original nasdaq marketsite are protected under united states patent 7 082 398 issued july 25 2006 inventors were thomas apple arlington virginia paul noble short hills new jersey john footen mount arlington new jersey and andrew klein brookline massachusetts the initial installation of the marketsite was in the former whitehall street location of nasdaq the current times square system and process have been upgraded and changed several times but remain protected by the broad claims and novel uses outlined in the original patent the current marketsite facility utilizes a complex system of videowall processors and data feeds to provide broadcasters with a dynamic real time data background this system shares nothing with the original whitehall street iteration of the marketsite having been upgraded and redesigned several times due to advances in technology
the nhl salary cap is the total amount of money that national hockey league teams are allowed to pay their players it is a hard cap meaning there are no exemptions and so no luxury tax penalties are required the actual amount of the cap varies on a year to year basis and is calculated as a percentage of the league s revenue from the previous season for instance in 2007 – 08 the nhl s salary cap was approximately us 50 3 million per team for the 2008 – 09 season it was 56 7 million for the 2009 10 season it was 56 8 million for the 2010 11 season it was 59 4 million and for the 2011 12 season it was 64 3 million following the 2012 – 13 lockout the 2012 – 13 salary cap has been set at 60 million but teams can still spend up to 70 2 million pro rated for the shortened season length like many professional sports leagues the nhl has a salary cap to keep teams in larger markets with more revenue from signing all of the top players and extending their advantage over smaller market franchises a salary cap existed in the early days of the national hockey league nhl during the great depression for example the league was under financial pressure to lower its salary cap to 62 500 per team and 7 000 per player forcing some teams to trade away well paid star players in order to fit the cap
np hardness non deterministic polynomial time hard in computational complexity theory is a class of problems that are informally at least as hard as the hardest problems in np more precisely a problem h is np hard when every problem l in np can be reduced in polynomial time to h that is given a solution for l we can verify it is a solution for h in polynomial time as a consequence finding a polynomial algorithm to solve any np hard problem would give polynomial algorithms for all the problems in np which is unlikely as many of them are considered hard a common misconception is that the np in np hard stands for non polynomial when in fact stands for non deterministic polynomial acceptable problems although it is suspected that there are no polynomial time algorithms for np hard problems this has never been proven moreover the class p in which all problems can be solved in polynomial time is contained in the np class
nut carcinoma formerly nut midline carcinoma is a rare genetically defined very aggressive squamous cell epithelial cancer that usually arises in the midline of the body and is characterized by a chromosomal rearrangement in the nuclear protein in testis gene in approximately 75 of cases the coding sequence of nutm 1 on chromosome 15 q 14 is fused to brd 4 or brd 3 which creates a chimeric gene that encodes the brd nut fusion protein the remaining cases the fusion of nutm 1 is to an unknown partner gene usually called nut variant
nasha is a hash function accepted as a first round sha 3 candidate for the nist hash function competition nasha was designed by smile markovski and aleksandra mileva with contributions by simona samardziski programmer and boro jakimovski programmer nasha supports internal state sizes of 1024 and 2048 bits and arbitrary output sizes between 125 and 512 bits it uses quasigroup string transformations with quasigroups of order 264 defined by extended feistel networks the quasigroups used in every iteration of the compression function are different and depend on the processed message block the authors claim performance of up to 23 06 cycles per byte on an intel core 2 duo in 64 bit mode cryptanalysis during the sha 3 competition has indicated that 384 512 version of nasha is susceptible to collision attacks but the authors disputed those attacks and also included small changes to achieve the strength of 224 256 version
nablus mask like facial syndrome is a microdeletion syndrome triggered by a deletion at chromosome 8 q 22 1 that causes a mask like facial appearance in those affected it is characterized by a narrowing of the eyes tight glistening facial skin and a flat broad nose other features of the syndrome include malformed ears unusual hair patterns on the scalp bent fingers and toes and joint deformities in the hands and feet unusual teeth mild developmental delay cryptorchidism and a generally happy disposition it is a rare genetic disorder by inheritance found in palestinian people named after nablus city in the west bank it is part of many new genetic disorders of newborns that is increasing exponentially in arabs in recent years as reported by centre for arab genomic studies in dubai
a nabothian cyst or nabothian follicle is a mucus filled cyst on the surface of the cervix they are most often caused when stratified squamous epithelium of the ectocervix toward the vagina grows over the simple columnar epithelium of the endocervix toward the uterus this tissue growth can block the cervical crypts subdermal pockets usually 2 – 10 mm in diameter trapping cervical mucus inside the crypts
naegeli – franceschetti – jadassohn syndrome nfjs also known as chromatophore nevus of naegeli and naegeli syndrome is a rare autosomal dominant form of ectodermal dysplasia characterized by reticular skin pigmentation diminished function of the sweat glands the absence of teeth and hyperkeratosis of the palms and soles one of the most striking features is the absence of fingerprint lines on the fingers naegeli syndrome is similar to dermatopathia pigmentosa reticularis both of which are caused by a specific defect in the keratin 14 protein
naegleriasis also known as primary amoebic meningoencephalitis pam amebic encephalitis and naegleria infection is an infection of the brain by the free living protist naegleria fowleri also known as the brain eating amoeba the term brain eating amoeba has also been applied to balamuthia mandrillaris causing some confusion between the two however balamuthia mandrillaris is unrelated to naegleria fowleri and causes a different disease called granulomatous amoebic encephalitis and unlike naegleriasis which is usually seen in people with normal immune function granulomatous amoebic encephalitis is usually seen in people with poor immune function such as those with hiv aids or leukemia n fowleri is typically found in warm bodies of fresh water such as ponds lakes rivers and hot springs it is also found in soil poorly maintained municipal water supplies water heaters near warm water discharges of industrial plants and in poorly chlorinated or unchlorinated swimming pools in an amoeboid or temporary flagellate stage there is no evidence of it living in salt water although infection occurs rarely it nearly always results in death with a case fatality rate greater than 95
naga fireballs thai บั้งไฟพญานาค rtgs bang fai phaya nak also known as mekong lights and bung fai paya nak by the locals is a phenomenon said to be often seen on the mekong river glowing balls are alleged to naturally rise from the water high into the air the balls are said to be reddish and to range in size from smaller sparkles up to the size of basketballs they quickly rise up to a couple of hundred metres before disappearing the number of fireballs reported varies between tens and thousands per night the phenomenon is named after the phaya naga legendary serpentine creatures said to live in the mekong
nager acrofacial dysostosis is a congenital anomaly syndrome nager syndrome displays several or all of the following characteristics underdevelopment of the cheek and jaw area down sloping of the opening of the eyes lack or absence of the lower eyelashes kidney and or stomach reflux hammer toes shortened soft palate petite lack of development of the internal and external ear possible cleft palate underdevelopment or absence of the thumb hearing loss see hearing loss with craniofacial syndromes and shortened forearms as well as poor movement in the elbow and may be characterized by accessory tragi occasionally sufferers develop vertebral anomalies such as scoliosis and sufferers do not usually have problems with their reproductive organs inheritance pattern said to be autosomal but there are arguments as to whether it is autosomal dominant or autosomal recessive most cases tend to be sporadic nager syndrome is also linked to five other similar syndromes miller syndrome treacher collins pierre robin genee wiedemann and franceschetti zwahlen klein an extremely rare congenital defect that has only had 75 documented cases to date 11 17 1999 with several or all of the following characteristics underdevelopment of the cheek and jaw area down sloping of the opening of the eyes lack or absence of the lower eyelashes lack of development of the internal and external ear possible cleft palate underdevelopment or absence of the thumb and shortened forearms as well as poor movement in the elbow
nail biting also known as onychophagy or onychophagia is an oral compulsive habit it is sometimes described as a parafunctional activity the common use of the mouth for an activity other than speaking eating or drinking nail biting is very common especially amongst children less innocent forms of nails biting are considered an impulse control disorder in the dsm iv r and is classified under obsessive compulsive and related disorders in the dsm 5 the icd 10 classifies it as other specified behavioral and emotional disorders with onset usually occurring in childhood and adolescence however not all nail biting is pathological and the difference between harmful obsession and normal behavior is not always clear
nail clubbing also known as digital clubbing is a deformity of the finger or toe nails associated with a number of diseases mostly of the heart and lungs clubbing for no obvious reason can also occur but is rare hippocrates was probably the first to document clubbing as a sign of disease and the phenomenon is therefore occasionally called hippocratic fingers
nail diseases are distinct from diseases of the skin although nails are a skin appendage they have their own signs and symptoms which may relate to other medical conditions nail conditions that show signs of infection or inflammation require medical assistance deformity or disease of the nails may be referred to as onychosis
nail – patella syndrome nps also known as hood syndrome is a genetic disorder that results in small poorly developed nails and kneecaps but can also affect many other areas of the body such as the elbows chest and hips the name nail – patella can be very misleading because the syndrome often affects many other areas of the body including even the production of certain proteins those affected by nps may have one or more affected areas of the body and its severity varies depending on the individual it is also referred to as iliac horn syndrome hereditary onychoosteodysplasia hood syndrome fong disease or turner – kieser syndrome diagnosis of nps can be made at birth but is common for it to remain undiagnosed for several generations while there is no cure available for nps treatment is available and recommended
nakajo syndrome also called nodular erythema with digital changes is a rare autosomal recessive congenital disorder first reported in 1939 by a nakajo in the offspring of consanguineous blood relative parents the syndrome can be characterized by erythema reddened skin loss of body fat in the upper part of the body and disproportionately large eyes ears nose lips and fingers
naked objects is an architectural pattern used in software engineering
a name reaction is a chemical reaction named after its discoverers or developers well known examples include the wittig reaction the claisen condensation the friedel crafts acylation and the diels alder reaction among the tens of thousands of organic reactions that are known hundreds of such reactions are well known enough to be named after people books have been published devoted exclusively to name reactions the merck index a chemical encyclopedia also includes an appendix on name reactions as organic chemistry developed during the 20 th century chemists started associating synthetically useful reactions with the names of the discoverers or developers in many cases the name is merely a mnemonic some cases of reactions that were not really discovered by their namesakes are known examples include the pummerer rearrangement the pinnick oxidation and the birch reduction although systematic approaches for naming reactions based on the reaction mechanism or the overall transformation exist such as the iupac nomenclature for transformations the more descriptive names are often unwieldy or not specific enough so people names are often more practical for efficient communication
nanometrology is a subfield of metrology concerned with the science of measurement at the nanoscale level nanometrology has a crucial role in order to produce nanomaterials and devices with a high degree of accuracy and reliability in nanomanufacturing a challenge in this field is to develop or create new measurement techniques and standards to meet the needs of next generation advanced manufacturing which will rely on nanometer scale materials and technologies the needs for measurement and characterization of new sample structures and characteristics far exceed the capabilities of current measurement science anticipated advances in emerging u s nanotechnology industries will require revolutionary metrology with higher resolution and accuracy than has previously been envisioned
the napkin folding problem is a problem in geometry and the mathematics of paper folding that explores whether folding a square or a rectangular napkin can increase its perimeter the problem is known under several names including the margulis napkin problem suggesting it is due to grigory margulis and the arnold s rouble problem referring to vladimir arnold and the folding of a russian ruble bank note some versions of the problem were solved by robert j lang svetlana krat alexey s tarasov and ivan yaschenko one form of the problem remains open
napkin psoriasis or psoriasis in the diaper area is characteristically seen in infants between two and eight months of age
napoleon s problem is a famous compass construction problem in it a circle and its center are given the challenge is to divide the circle into four equal arcs using only a compass napoleon was known to be an amateur mathematician but it is not known if he either created or solved the problem napoleon s friend the italian mathematician lorenzo mascheroni introduced the limitation of using only a compass no straight edge into geometric constructions but actually the challenge above is easier than the real napoleon s problem consisting in finding the center of a given circle with compass alone the following sections will describe solutions to both problems and proofs that they work georg mohr s 1672 book euclides danicus anticipated mascheroni s idea though the book was only rediscovered in 1928
narcissistic personality disorder npd is a long term pattern of abnormal behavior characterized by exaggerated feelings of self importance an excessive need for admiration and a lack of understanding of others feelings people affected by it often spend a lot of time thinking about achieving power or success or about their appearance they often take advantage of the people around them the behavior typically begins by early adulthood and occurs across a variety of situations the cause of narcissistic personality disorder is unknown it is a personality disorder classified within cluster b by the diagnostic and statistical manual of mental disorders diagnosis is by a healthcare professional interviewing the person in question the condition needs to be differentiated from mania and substance use disorder treatments have not been well studied therapy is often difficult as people frequently do not consider themselves to have a problem the personality was first described in 1925 by robert waelder while the current name for the condition came into use in 1968 about one percent of people are believed to be affected at some point in their life it appears to occur more often in males than females and affects young people more than older people
narcissistic rage is a reaction to narcissistic injury which is a perceived threat to a narcissist s self esteem or self worth narcissistic injury or narcissistic scar is a phrase used by sigmund freud in the 1920 s narcissistic wound and narcissistic blow are further almost interchangeable terms the term narcissistic rage was coined by heinz kohut in 1972 narcissistic injury occurs when a narcissist feels that their hidden true self has been revealed this may be the case when the narcissist has a fall from grace such as when their hidden behaviors or motivations are revealed or when their importance is brought into question narcissistic injury is a cause of distress and can lead to dysregulation of behaviors as in narcissistic rage narcissistic rage occurs on a continuum from instances of aloofness and expression of mild irritation or annoyance to serious outbursts including violent attacks and murder narcissistic rage reactions are not limited to personality disorders and may be also seen in catatonic paranoid delusion and depressive episodes it has also been suggested that narcissists have two layers of rage the first layer of rage can be thought of as a constant anger towards someone else with the second layer being a self aimed wrath
narcolepsy is a long term neurological disorder that involves a decreased ability to regulate sleep wake cycles symptoms include periods of excessive daytime sleepiness that usually lasts from seconds to minutes and may occur at any time about 70 also have periods of sudden loss of muscle strength known as cataplexy these spells can be brought on by strong emotions less commonly there may be vivid dream like images or the inability to move for a period of time during falling asleep or upon waking up people with narcolepsy sleep about the same amount of hours per day as people without but the quality of sleep tends to be worse the cause of narcolepsy is unknown in up to 10 of cases there is a family history of the disorder often those affected have low levels of the neurotransmitter hypocretin which may be due to an autoimmune disorder trauma certain infections toxins or psychological stress may also play a role diagnosis is typically based on the symptoms and sleep studies after ruling out other potential causes excessive daytime sleepiness can also be caused by other sleep disorders such as sleep apnea major depressive disorder anemia heart failure drinking alcohol and not getting enough sleep cataplexy may be mistaken for seizures while there is no cure a number of lifestyle changes and medications may help lifestyle changes include taking regular short naps and sleep hygiene medications used include modafinil sodium oxybate and methylphenidate while initially fairly effective tolerance to the benefits may develop tricyclic antidepressants and selective serotonin reuptake inhibitors ssris may improve cataplexy about 0 2 to 600 per 100 000 people are affected the condition often begins in childhood men and women are affected equally untreated narcolepsy increases the risk of motor vehicle collisions and falls the term narcolepsy is from the french narcolepsie the french term was first used in 1880 by jean baptiste édouard gélineau who used the greek νάρκη narkē meaning numbness and λῆψις lepsis meaning attack
narcotic dermopathy is a skin condition caused by the injection of drugs intravenously resulting in thrombosed cordlike thickened veins at the site of injection
the narrow escape problem is a ubiquitous problem in biology biophysics and cellular biology the formulation is the following a brownian particle ion molecule or protein is confined to a bounded domain a compartment or a cell by a reflecting boundary except for a small window through which it can escape the narrow escape problem is that of calculating the mean escape time this time diverges as the window shrinks thus rendering the calculation a singular perturbation problem
this article concerns nasal congestion as a symptom for the natural partial congestion of the nose see nasal cycle nasal congestion is the blockage of the nasal passages usually due to membranes lining the nose becoming swollen from inflamed blood vessels it is also known as nasal blockage nasal obstruction blocked nose stuffy nose or plugged nose nasal decongestants target the discomfort directly these come as nasal sprays inhalers and as oral pills nasal congestion has many causes and can range from a mild annoyance to a life threatening condition the newborn infant prefers to breathe through the nose historically referred to as obligate nasal breathers nasal congestion in an infant in the first few months of life can interfere with breastfeeding and cause life threatening respiratory distress in older children and adolescents it is often just an annoyance but can cause other difficulties nasal congestion can interfere with the hearing and speech significant congestion may interfere with sleep cause snoring and can be associated with sleep apnea in children nasal congestion from enlarged adenoids has caused chronic sleep apnea with insufficient oxygen levels and hypoxia as well as right sided heart failure the problem usually resolves after surgery to remove the adenoids and tonsils however the problem often relapses later in life due to craniofacial alterations from chronic nasal congestion nasal congestion can also cause mild facial and head pain and a degree of discomfort often from allergies or the common cold
a nasal fracture commonly referred to as a broken nose is a fracture of one of the bones of the nose because of the protrusion of the nose from the face and the fragility of the bones of the nose a broken nose is one of the most common facial injuries comprising almost 40 of all facial injuries
nasal glioma also known more correctly as nasal glial heterotopia along with brain like heterotopia cephalic brain like heterotopia glial hamartoma nasal cerebral heterotopia heterotopic neuroglial tissue and nasal heterotopic brain tissue is a rare benign congenital lesion usually a firm incompressible reddish blue to purple lesion occurring on the nasal bridge or midline near the root
nasal polyps np are non cancerous growths within the nose or sinuses symptoms include trouble breathing through the nose loss of smell decreased taste post nasal drip and a runny nose the growths are sac like movable and nontender they typically occur in both nostrils in those who are affected face pain may occasionally occur complications may include sinusitis the exact cause is unclear they occur more commonly among people who have allergies cystic fibrosis aspirin sensitivity or certain infections they are overgrowths of the mucous membranes diagnosis may occur by looking up the nose and a ct scan may be used to help plan treatment treatment is typically with steroids often in the form of a nasal spray if this is not effective surgery may be considered the condition may recur following surgery antihistamines may help with symptoms but do not change the underlying disease antibiotics are not required unless complications occur about 4 of people currently have nasal polyps while up to 40 of people develop them at some point in their life they most often occur after the age of 20 and are more frequent in males than females
nasal septal abscess is a condition of the nasal septum in which there is a collection of pus between the mucoperichondrium and septal cartilage
nasal septal hematoma haematoma is a condition affecting the nasal septum it can be associated with trauma because the septal cartilage has no blood supply of its own and receives all of its nutrients and oxygen from the perichondrium an untreated septal hematoma may lead to destruction of the septum immediate drainage is necessary failure to recognise septal hematomas or treat in a timely fashion can cause a saddle nose deformity
nasal septum deviation or deviated nasal septum dns is a physical disorder of the nose involving a displacement of the nasal septum some displacement is common affecting 80 of people most unknowingly
a nasal septum perforation is a medical condition in which the nasal septum the cartilaginous membrane dividing the nostrils develops a hole or fissure this may be brought on directly as in the case of nasal piercings or indirectly as by long term topical drug application including intranasal ethylphenidate methamphetamine cocaine crushed prescription pills or decongestant nasal sprays chronic epistaxis and as a complication of nasal surgery like septoplasty or rhinoplasty much less common causes for perforated nasal septums include rare granulomatous inflammatory conditions like granulomatosis with polyangiitis it has been reported as a side effect of anti angiogenesis drugs like bevacizumab
nasal vestibulitis is the diffuse dermatitis of nasal vestibule it is often caused by staphylococcus aureus it may be secondary to chronic rhinorrhea nose picking or viral infections in acute vestibulitis the skin is red swollen and tender in chronic vestibulitis induration of vestibular skin and crusting is seen it is treated by cleaning the nasal vestibule of all crusts with a cotton applicator soaked in hydrogen peroxide antibiotic steroid ointment is sometimes helpful chronic fissures are treated by cautery
nasodigitoacoustic syndrome also called keipert syndrome is a rare congenital syndrome first described by j a keipert and colleagues in 1973 the syndrome is characterized by a mishaped nose broad thumbs and halluces the big toes brachydactyly sensorineural hearing loss facial features such as hypertelorism unusually wide set eyes and developmental delay it is believed to be inherited in an x linked recessive manner which means a genetic mutation causing the disorder is located on the x chromosome and while two copies of the mutated gene must be inherited for a female to be born with the disorder just one copy is sufficient to cause a male to be born with the disorder nasodigitoacoustic syndrome is likely caused by a mutated gene located on the x chromosome between positions xq 22 2 – q 28 the incidence of the syndrome has not been determined but it is considered to affect less than 200 000 people in the united states and no greater than 1 per 2 000 in europe it is similar to keutel muenke rubinstein and teunissen cremers syndrome
nasolacrimal duct cysts are a cutaneous condition that is a developmental defect present at birth
nasolacrimal duct obstruction nldo is the obstruction of nasolacrimal duct and may be either congenital or acquired obstruction of the nasolacrimal duct leads to the excess overflow of tears called epiphora
nasopharyngeal angiofibroma also called juvenile nasopharyngeal angiofibroma is a histologically benign but locally aggressive vascular tumor that grows in the back of the nasal cavity it most commonly affects adolescent males patients with nasopharyngeal angiofibroma usually present with one sided nasal obstruction and recurrent bleeding
nasopharynx cancer or nasopharyngeal carcinoma npc is the most common cancer originating in the nasopharynx the uppermost region of the pharynx throat behind the nose where the nasal passages and auditory tubes join the remainder of the upper respiratory tract npc occurs in children and adults npc differs significantly from other cancers of the head and neck in its occurrence causes clinical behavior and treatment it is vastly more common in certain regions of east asia and africa than elsewhere with viral dietary and genetic factors implicated in its causation it is most common in males it is a squamous cell carcinoma or an undifferentiated type squamous epithelial cells are a flat type of cell found in the skin and the membranes that line some body cavities differentiation means how different the cancer cells are from normal cells undifferentiated is a word used to describe cells that do not have their mature features or functions
a national caveat is a restriction that north atlantic treaty organization nato members place on the use of their forces nato general john craddock nato s supreme allied commander europe saceur was quoted as saying all caveats must be removed in february 2007 in an article written by the associated press the level of constraints i e caveats is tied directly to the level of national interests a country has in a particular mission and the level of risk it is willing to take
the national debt of the united states is the amount owed by the federal government of the united states the measure of the public debt is the value of the outstanding treasury securities at a point of time that have been issued by the treasury and other federal government agencies the terms national deficit and national surplus usually refer to the federal government budget balance from year to year not the cumulative total a deficit year increases the debt because more money is spent than is received a surplus year decreases the debt because more money is received than spent there are two components of gross national debt debt held by the public such as treasury securities held by investors outside the federal government including those held by individuals corporations the federal reserve system and foreign state and local governments debt held by government accounts or intragovernmental debt such as non marketable treasury securities held in accounts administered by the federal government that are owed to program beneficiaries such as the social security trust fund debt held by government accounts represents the cumulative surpluses including interest earnings of these accounts that have been invested in treasury securities in general government debt increases as a result of government spending and decreases from tax or other receipts both of which fluctuate during the course of a fiscal year in practice treasury securities are not issued or redeemed on a day by day basis and may also be issued or redeemed as part of the federal government s macroeconomic monetary management operations the aggregate gross amount that treasury can borrow is limited by the united states debt ceiling historically the us public debt as a share of gross domestic product gdp has increased during wars and recessions and subsequently declined the ratio of debt to gdp may decrease as a result of a government surplus or due to growth of gdp and inflation for example debt held by the public as a share of gdp peaked just after world war ii 113 of gdp in 1945 but then fell over the following 35 years in recent decades however aging demographics and rising healthcare costs have led to concern about the long term sustainability of the federal government s fiscal policies on july 29 2016 debt held by the public was 14 trillion or about 76 of the previous 12 months of gdp intragovernmental holdings stood at 5 4 trillion giving a combined total gross national debt of 19 4 trillion or about 106 of the previous 12 months of gdp 6 2 trillion or approximately 45 of the debt held by the public was owned by foreign investors the largest of which were china and japan at about 1 25 trillion for china and 1 15 trillion for japan as of may 2016
nationalism in russia is nationalistic manifestations of the peoples of russia in the territory of russia the term nationalism in russia refers not only to ethnic russian east slavic ethnic group nationalism but also refers to nationalist activities of national minorities in russia in 1990 s during the so called parade of sovereignties russian regions proclaimed its sovereignty in the past 20 years nationalist activity takes place for example in chechnya and tatarstan
a borrowing limit is the amount of money that individuals could borrow from other individuals firms banks or governments there are many types of borrowing limits and a natural borrowing limit is one specific type of borrowing limit among those when individuals are said to face the natural borrowing limit it implies they are allowed to borrow up to the sum of all their future incomes a natural debt limit and a natural borrowing constraint are other ways to refer to the natural borrowing limit although the concept is widely discussed in the economic literatures it is less likely to observe lenders willing to lend up to the natural borrowing limit in the real economic activities borrowing limits are usually much more tighter than the natural borrowing limit due to the immature financial systems of the economyor the gap between the amount of information that the borrowers and lenders have the latter is usually referred to as an asymmetric information problem
in microbiology genetics cell biology and molecular biology competence is the ability of a cell to take up extracellular naked dna from its environment in the process called transformation competence may be differentiated between natural competence a genetically specified ability of bacteria which is thought to occur under natural conditions as well as in the laboratory and induced or artificial competence which arises when cells in laboratory cultures are treated to make them transiently permeable to dna this article primarily deals with natural competence in bacteria although information about artificial competence is also provided
in regard to agriculture abiotic stress is stress produced by natural environment factors such as extreme temperatures wind drought and salinity humankind doesn ’ t have much control over abiotic stresses it is very important for humans to understand how stress factors affect plants and other living things so that we can take some preventative measures preventative measures are the only way that humans can protect themselves and their possessions from abiotic stress there are many different types of abiotic stressors and several methods that humans can use to reduce the negative effects of stress on living things
nature connectedness is the extent to which individuals include nature as part of their identity it includes an understanding of nature and everything it is made up of even the parts that are not pleasing characteristics of nature connectedness are similar to those of a personality trait nature connectedness is stable over time and across various situations schultz describes three components that make up the nature connectedness construct the cognitive component is the core of nature connectedness and refers to how integrated one feels with nature the affective component is an individual s sense of care for nature the behavioral component is an individual ’ s commitment to protect the natural environment these three components make up nature connectedness and are required for a healthy relationship with nature if an individual feels connected to nature possibly by spending time in it they may be more inclined to care about nature and protect the environment recent research has found that nature exposure and feeling connected to nature at a trait level provides many benefits to humans such as well being other researchers describe the nature connectedness construct in a simpler manner for instance nature connectedness can be thought of as a love of nature also referred to as emotional affinity toward nature similarly nature connectedness can be defined as how much a person believes they are the same as nature more specifically a person s connectivity with nature or it can be thought of as simply feeling emotionally connected with nature nature connectedness as a construct is also known as nature relatedness connectivity with nature emotional affinity toward nature or inclusion of nature in self although nature relatedness is a stable individual trait it can change based on one ’ s experience with nature meaning the more time an individual spends in nature the more connected they feel to nature and the more concern they may feel for nature feeling connected to nature at a state level has many benefits as well such as more positive moods and less negative moods even though humans derive many benefits from nature our modern lifestyles have created a disconnect from the natural environment wherein we spend significantly more time indoors some researchers estimate that humans spend up to 90 of their lives indoors this disconnection from nature can have a negative impact on humans because we are missing out on the beneficial effects of nature as a result we are less connected to nature and feel less responsibility to protect this environment
nausea is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit it may precede vomiting but a person can have nausea without vomiting when prolonged it is a debilitating symptom nausea is a non specific symptom which means that it has many possible causes some common causes of nausea are motion sickness dizziness migraine fainting gastroenteritis stomach infection or food poisoning nausea is a side effect of many medications including chemotherapy nauseants or morning sickness in early pregnancy nausea may also be caused by anxiety disgust and depression medications taken to prevent and treat nausea are called antiemetics the most commonly prescribed antiemetics in the us are promethazine metoclopramide and ondansetron the word nausea is from latin nausea from greek ναυσία – nausia ναυτία – nautia motion sickness feeling sick or queasy
navel displacement is a condition in yogic beliefs when the navel centre shifts
navicular syndrome often called navicular disease is a syndrome of soundness problems in horses it most commonly describes an inflammation or degeneration of the navicular bone and its surrounding tissues usually on the front feet it can lead to significant and even disabling lameness
naxos disease also known as diffuse non epidermolytic palmoplantar keratoderma with woolly hair and cardiomyopathy diffuse palmoplantar keratoderma with woolly hair and arrhythmogenic right ventricular cardiomyopathy firstly described in naxos island by dr nikos protonotarios and naxos disease is a cutaneous condition characterized by a palmoplantar keratoderma the prevalence of the syndrome is about 1 person in 1000 in the hellenic islands it has been associated with mutations in the genes encoding desmoplakin and plakoglobin
the nazarov cyclization reaction often referred to as simply the nazarov cyclization is a chemical reaction used in organic chemistry for the synthesis of cyclopentenones the reaction is typically divided into classical and modern variants depending on the reagents and substrates employed it was originally discovered by ivan nikolaevich nazarov 1906 – 1957 in 1941 while studying the rearrangements of allyl vinyl ketones the nazarov cyclization reaction as originally described the nazarov cyclization involves the activation of a divinyl ketone using a stoichiometric lewis acid or protic acid promoter the key step of the reaction mechanism involves a cationic 4 π electrocyclic ring closure which forms the cyclopentenone product see mechanism below as the reaction has been developed variants involving substrates other than divinyl ketones and promoters other than lewis acids have been subsumed under the name nazarov cyclization provided that they follow a similar mechanistic pathway the success of the nazarov cyclization as a tool in organic synthesis stems from the utility and ubiquity of cyclopentenones as both motifs in natural products including jasmone the aflatoxins and a subclass of prostaglandins and as useful synthetic intermediates for total synthesis the reaction has been used in several total syntheses and several reviews have been published
nazi memorabilia are items of nazi origin that are collected by museums and private individuals much of it comes from soldiers who collected small items as trophies during the second world war
naïve physics or folk physics is the untrained human perception of basic physical phenomena in the field of artificial intelligence the study of naïve physics is a part of the effort to formalize the common knowledge of human beings many ideas of folk physics are simplifications misunderstandings or misperceptions of well understood phenomena incapable of giving useful predictions of detailed experiments or simply are contradicted by more thorough observations they may sometimes be true be true in certain limited cases be true as a good first approximation to a more complex effect or predict the same effect but misunderstand the underlying mechanism naïve physics can also be defined as an intuitive understanding all humans have about objects in the physical world cognitive psychologists are delving deeper into these phenomena with promising results psychological studies indicate that certain notions of the physical world are innate in all of us
near sightedness also known as short sightedness and myopia is a condition of the eye where light focuses in front instead of on the retina this causes distant objects to be blurry while close objects appear normal other symptoms may include headaches and eye strain severe near sightedness increases the risk of retinal detachment cataracts and glaucoma the underlying cause is believed to be a combination of genetic and environmental factors risk factors include doing work that involves focusing on close objects greater time spent indoors and a family history of the condition it is also associated with a high socioeconomic class the underlying mechanism involves the length of the eyeball being too long or less commonly the lens being too strong it is a type of refractive error diagnosis is by eye examination there is tentative evidence that near sightedness can be prevented by having young children spend more time outside this may be related to natural light exposure near sightedness can be corrected with eyeglasses contact lenses or surgery eyeglasses are the easiest and safest method of correction contact lenses can provide a wider field of vision however are associated with a risk of infection refractive surgery permanently changes the shape of the cornea near sightedness is the most common eye problem and is estimated to affect 1 5 billion people 22 of the population rates vary significantly in different areas of the world rates among adults are between 15 and 49 rates are similar in males and females among children it affect 1 2 of rural nepalese 4 of south africans 12 of americans and 37 in some large chinese cities rates have increased since the 1950 s uncorrected near sightedness is one of the most common causes of vision loss globally along with cataracts macular degeneration and vitamin a deficiency
nearest neighbor search nns also known as proximity search similarity search or closest point search is an optimization problem for finding closest or most similar points closeness is typically expressed in terms of a dissimilarity function the less similar the objects the larger the function values formally the nearest neighbor nn search problem is defined as follows given a set s of points in a space m and a query point q ∈ m find the closest point in s to q donald knuth in vol 3 of the art of computer programming 1973 called it the post office problem referring to an application of assigning to a residence the nearest post office a direct generalization of this problem is a k nn search where we need to find the k closest points most commonly m is a metric space and dissimilarity is expressed as a distance metric which is symmetric and satisfies the triangle inequality even more common m is taken to be the d dimensional vector space where dissimilarity is measured using the euclidean distance manhattan distance or other distance metric however the dissimilarity function can be arbitrary one example are asymmetric bregman divergences for which the triangle inequality does not hold
in probability and statistics a nearest neighbor function nearest neighbor distance distribution nearest neighbor distribution function or nearest neighbor distribution is a mathematical function that is defined in relation to random mathematical objects known as point processes which are types of stochastic processes often used as mathematical models of physical phenomena representable as randomly positioned points in time space or both more specifically nearest neighbor functions are defined with respect to some point in the point process as being the probability distribution of the distance from this point to its nearest neighboring point in the same point process hence they are used to describe the probability of another point existing within some distance of a point a nearest neighbor function can be contrasted with a spherical contact distribution function which is not defined in reference to some initial point but rather as the probability distribution of the radius of a sphere when it first encounters or makes contact with a point of a point process nearest neighbor function are used in the study of point processes as well as the related fields of stochastic geometry and spatial statistics which are applied in various scientific and engineering disciplines such as biology geology physics and telecommunications
in civil engineering and construction the neat volume is a theoretical amount of material for earthworks it can refer to the volume either before native material is disturbed by excavation or after placement and compaction is complete a percentage is typically added to neat volume to estimate loose i e uncompacted volumes for procurement purposes with concrete work neat volume is calculated assuming there is no bowing in the formwork or for cast in place concrete that the surfaces in contact with the concrete have no voids or imperfections that would require a greater volume of concrete to fill
the neber rearrangement is an organic reaction in which an oxime is converted into an alpha aminoketone in a rearrangement reaction neber rearrangement the oxime is first converted to a ketoxime tosylate by reaction with tosyl chloride added base forms a carbanion which displaces the tosylate group in a nucleophilic displacement to an azirine and added water subsequently hydrolyses it to the aminoketone the beckmann rearrangement is a side reaction
necatoriasis is the condition of infection by necator hookworms such as necator americanus this hookworm infection is a type of helminthiasis infection which is a type of neglected tropical disease
neck pain or cervicalgia is a common problem with two thirds of the population having neck pain at some point in their lives neck pain although felt in the neck can be caused by numerous other spinal problems neck pain may arise due to muscular tightness in both the neck and upper back or pinching of the nerves emanating from the cervical vertebrae joint disruption in the neck creates pain as does joint disruption in the upper back the head is supported by the lower neck and upper back and it is these areas that commonly cause neck pain the top three joints in the neck allow for most movement of the neck and head the lower joints in the neck and those of the upper back create a supportive structure for the head to sit on if this support system is affected adversely then the muscles in the area will tighten leading to neck pain neck pain affects about 5 of the global population as of 2010
necklace of venus is a cutaneous condition characterized by a background hyperpigmentation with superimposed white macules on neck
the necklace problem is a problem in recreational mathematics solved in the early 21 st century
necrobiosis is the physiological death of a cell and can be caused by conditions such as basophilia erythema or a tumor it is identified both with and without necrosis it is associated with necrobiosis lipoidica and granuloma annulare necrobiosis differs from apoptosis which kills a damaged cell to protect the body from harm
necrobiosis lipoidica is a necrotising skin condition that usually occurs in patients with diabetes mellitus but can also be associated with rheumatoid arthritis in the former case it may be called necrobiosis lipoidica diabeticorum nld nld occurs in approximately 0 3 of the diabetic population with the majority of sufferers being women approximately 3 1 females to males affected the severity or control of diabetes in an individual does not affect who will or will not get nld better maintenance of diabetes after being diagnosed with nld will not change how quickly the nld will resolve
necrobiotic xanthogranuloma also known as necrobiotic xanthogranuloma with paraproteinemia is a multisystem disease that affects older adults and is characterized by prominent skin findings
necrolytic acral erythema is a cutaneous condition that is a manifestation of hepatitis c viral infection or zinc deficiency it is a papulosquamous and sometimes vesiculobullous eruption bearing clinical and histologic similarity to other necrolytic erythemas such as necrolytic migratory erythema pseudoglucagonoma and nutritional deficiency syndromes
necrolytic migratory erythema nme is a red blistering rash that spreads across the skin it particularly affects the skin around the mouth and distal extremities but may also be found on the lower abdomen buttocks perineum and groin it is strongly associated with glucagonoma a glucagon producing tumor of the pancreas but is also seen in a number of other conditions including liver disease and intestinal malabsorption
necrophilia also called thanatophilia is a sexual attraction or sexual act involving corpses the attraction is classified as a paraphilia by the diagnostic and statistical manual dsm of the american psychiatric association the term was coined by the belgian alienist joseph guislain who first used it in a lecture in 1850 it derives from the greek words νεκρός nekros dead and φιλία philia love rosman and resnick 1989 reviewed information from 34 cases of necrophilia describing the individuals motivations for their behaviors these individuals reported the desire to possess a non resisting and non rejecting partner 68 reunions with a romantic partner 21 sexual attraction to corpses 15 comfort or overcoming feelings of isolation 15 or seeking self esteem by expressing power over a homicide victim 12
necrospermia or necrozoospermia is a condition in which spermatozoa in semen are either immobile or dead
necrotising hepatopancreatitis nhp also known as the early mortality syndrome ems acute hepatopancreatic necrosis syndrome ahpns texas pond mortality syndrome tpms texas necrotizing hepatopancreatitis tnhp and peru necrotizing hepatopancreatitis pnhp is a lethal epizootic disease of farmed shrimp it is not very well researched yet but generally assumed to be caused by a bacterial infection nhp mainly affects the farmed shrimp species litopenaeus vannamei pacific white shrimp and litopenaeus stylirostris western blue shrimp but has also been reported in three other american species namely farfantepenaeus aztecus farfantepenaeus californiensis and litopenaeus setiferus the highest mortality rates occur in l vannamei which is one of the two most frequently farmed species of shrimp untreated the disease causes mortality rates of up to 90 within 30 days a first outbreak of nhp had been reported in texas in 1985 the disease then spread to shrimp aquacultures in south america in 2009 to china and subsequently southeast asia followed by massive outbreaks in that region in 2012 13 nhp is associated with a small gram negative and highly pleomorphic rickettsia like bacterium that belongs to its own new genus in the alpha proteobacteria however in early 2013 a novel strain of vibrio parahaemolyticus was identified as a more likely causative agent though involvement of a virus cannot be definitely ruled out yet infected shrimps show gross signs including soft shells and flaccid bodies black or darkened gills dark edges of the pleopods and uropods and an atrophied hepatopancreas that is whitish instead of orange or tan as is usual whichever of the two bacteria associated with nhp actually causes it the pathogen seems to prefer high water temperatures above 29 ° c or 84 ° f and elevated levels of salinity more than 20 – 38 ppt avoiding such conditions in shrimp ponds is thus an important disease control measure
necrotizing enterocolitis nec is a medical condition primarily seen in premature infants where portions of the bowel undergo necrosis tissue death it occurs postnatally i e it is not seen in stillborn infants and is the second most common cause of morbidity in premature infants causing 355 deaths per year in the united states in 2013 down from 484 in 2009 rates per 100 000 live births were almost three times higher for blacks than for whites
necrotising fasciitis nf commonly known as flesh eating disease is an infection that results in the death of the body s soft tissue it is a severe disease of sudden onset that spreads rapidly symptoms include red or purple skin in the affected area severe pain fever and vomiting the most commonly affected areas are the limbs and perineum typically the infection enters the body through a break in the skin such as a cut or burn risk factors include poor immune function such as from diabetes or cancer obesity alcoholism intravenous drug use and peripheral vascular disease it is not typically spread between people the disease is classified into four types depending on the infecting organism between 55 80 of cases involve more than one type of bacteria methicillin resistant staphylococcus aureus mrsa is involved in up to a third of cases medical imaging is helpful to confirm the diagnosis prevention is by good wound care and handwashing it is usually treated with surgery to remove the infected tissue and intravenous antibiotics often a combination of antibiotics are used such as penicillin g clindamycin vancomycin and gentamicin delays in surgery are associated with a higher risk of death despite high quality treatment the risk of death is between 25 and 35 necrotizing fasciitis affects 0 4 to 1 person per 100 000 per year both sexes are affected equally it becomes more common among older people and is very rare in children necrotizing fasciitis has been described at least since the time of hippocrates the term necrotising fasciitis first came into use in 1952
necrotizing meningoencephalitis nme is an inflammatory disease of the central nervous system cns that occurs in young small breed dogs necrotizing meningoencephalitis has been described in numerous small breeds including the pug maltese and chihuahua meningoencephalitis refers to inflammation of the meninges meningitis and brain encephalitis the cause of inflammation in nme is unknown although many speculate that it is an autoimmune disorder necrotizing meningoencephalitis is fatal without aggressive immunosuppressive treatment and is frequently fatal despite immunosuppressive therapy since nme can not be definitively diagnosed before death it is difficult to truly determine the prognosis another similar inflammatory cns disorder of dogs is granulomatous meningoencephalitis gme
necrotizing periodontal diseases are a type of inflammatory periodontal gum disease caused by bacteria notably fusobacteria and spirochaete species the diseases appear to represent different severities or stages of the same disease process although this is not completely certain these diseases usually have a sudden onset and so the term acute is often added to the diagnosis the mildest on the spectrum is necrotizing ulcerative gingivitis nug followed by the successively more severe conditions necrotizing ulcerative periodontitis nup necrotizing stomatitis and finally cancrum oris noma which is frequently fatal
necrotizing sialometaplasia ns is a benign ulcerative lesion usually located towards the back of the hard palate it is thought to be caused by ischemic necrosis death of tissue due to lack of blood supply of minor salivary glands in response to trauma often painless the condition is self limiting and should heal in 6 – 10 weeks although entirely benign and requiring no treatment due to its similar appearance to oral cancer it is sometimes misdiagnosed as malignant therefore it is considered an important condition despite its rarity
needle ice is a phenomenon that occurs when the temperature of the soil is above 0 ° c 32 ° f and the surface temperature of the air is below 0 ° c 32 ° f the subterranean liquid water is brought to the surface via capillary action where it freezes and contributes to a growing needle like ice column the ice needles are typically a few centimetres long while growing they may lift or push away small soil particles on sloped surfaces needle ice may be a factor contributing to soil creep alternate names for needle ice are frost pillars säuleneis in german frost column kammeis a german term meaning comb ice stängeleis another german term referring to the stem like structures shimobashira 霜柱 a japanese term meaning frost pillars or pipkrake from swedish pipa tube and krake weak fine coined in 1907 by henrik hesselman the similar phenomena of frost flowers and hair ice can occur on living or dead plants especially on wood
a needlestick injury percutaneous injury or percutaneous exposure incident is the penetration of skin by a needle or other sharp object which was in contact with blood tissue or other body fluid before the exposure occupational needlestick injuries primarily affect healthcare workers who make up 80 of needlestick injuries in the united states various other occupations are also at increased risk of needlestick injury including law enforcement laborers tattoo artists food preparers and agricultural workers though the acute physiological effects of a needlestick injury are generally negligible these devices can transmit blood borne diseases placing those exposed at increased risk of contracting infectious diseases such as hepatitis b hbv hepatitis c hcv and the human immunodeficiency virus hiv among healthcare workers and laboratory personnel worldwide more than 25 blood borne viruses have been reported to be caused by needlestick injuries it is estimated that half of all occupational needlestick injuries are not reported additionally an unknown number of occupational needlestick injuries are reported by the affected employee yet due to organizational failure institutional record of the injury does not exist increasing recognition of the unique occupational hazard posed by needlestick injuries as well as the development of efficacious interventions to minimize the largely preventable occupational risk encouraged legislative regulation in the us causing a decline in needlestick injuries among healthcare workers
the nef reaction is an organic reaction describing the acid hydrolysis of a salt of a primary or secondary nitroalkane 1 to an aldehyde or a ketone 3 and nitrous oxide 4 the reaction has been the subject of several literature reviews the nef reaction the reaction was reported in 1894 by the chemist john ulric nef who treated the sodium salt of nitroethane with sulfuric acid resulting in an 85 – 89 yield of nitrous oxide and at least 70 yield of acetaldehyde however the reaction was pioneered a year earlier in 1893 by konovalov who converted the potassium salt of 1 phenylnitroethane with sulfuric acid to acetophenone the nef reaction should not be confused with the nef synthesis
negative branch reservations is an emerging phenomenon from eliyahu goldratt s theory of constraints a negative branch reservation is a cause and effect analysis of a situation this thinking skill is used to map out what can go wrong in a process of change and help to anticipate any negative outcomes this technique uses these forms in its analysis thinking processes of the theory future reality tree transition tree or prerequisite tree
negative luminescence is a physical phenomenon by which an electronic device emits less thermal radiation when an electric current is passed through it than it does in thermal equilibrium current off when viewed by a thermal camera an operating negative luminescent device looks colder than its environment
negative priming is an implicit memory effect in which prior exposure to a stimulus unfavorably influences the response to the same stimulus it falls under the category of priming which refers to the change in the response towards a stimulus due to a subconscious memory effect negative priming describes the slow and error prone reaction to a stimulus that is previously ignored for example a subject may be imagined trying to pick a red pen from a pen holder the red pen becomes the target of attention so the subject responds by moving their hand towards it at this time they mentally block out all other pens as distractors to aid in closing in on just the red pen after repeatedly picking the red pen over the others switching to the blue pen results in a momentary delay picking the pen out however there is a decline in the negative priming effect when there is more than one nontarget item that is selected against the slow reaction due to the change of the distractor stimulus to target stimulus is called the negative priming effect negative priming is believed to play a crucial role in attention and memory retrieval processes when stimuli are perceived through the senses all the stimuli are encoded within the brain where each stimulus has its own internal representation in this perceiving process some of the stimuli receive more attention than others similarly only some of them are stored in short term memory negative priming is highly related to the selective nature of attention and memory broadly negative priming is also known as the mechanism by which inhibitory control is applied to cognition this refers only to the inhibition stimuli that can interfere with the current short term goal of creating a response the effectiveness of inhibiting the interferences depends on the cognitive control mechanism as a higher number of distractors yields higher load on working memory increased load on working memory can in turn result in slower perceptual processing leading to delayed reaction therefore negative priming effect depends on the amount of distractors effectiveness of the cognitive control mechanism and the availability of the cognitive control resources
the negative therapeutic reaction in psychoanalysis is the paradoxical phenomenon whereby a plausible interpretation produces rather than improvement a worsening of the analysand s condition
neglect is a form of abuse where the perpetrator is responsible for caring for someone who is unable to care for himself or herself but fails to do so neglect may include the failure to provide sufficient supervision nourishment or medical care or the failure to fulfill other needs for which the victim cannot provide themselves the term is also applied when necessary care is withheld by those responsible for providing it from animals plants and even inanimate objects neglect can carry on in a child s life falling into many long term side effects such as physical injuries low self esteem attention disorders violent behavior and can even cause death
the neglected firm effect is the phenomenon of lesser known firms producing abnormally high returns on their stocks the companies that are followed by fewer analysts will earn higher returns on average than companies that are followed by many analysts the abnormally high return exhibited by neglected firms may be due to the lower liquidity or higher risks associated with the stock according to investopedia neglected firms are usually the small firms that analysts tend to ignore information available on these companies tends to be limited to those items that are required by law on the other hand have a higher profile which provides large amounts of high quality information in addition to legally required forms to institutional investors such as pension or mutual fund companies
neglected tropical diseases ntds are a diverse group of tropical infections which are especially common in low income populations in developing regions of africa asia and the americas they are caused by a variety of pathogens such as viruses bacteria protozoa and helminths these diseases are contrasted with the big three diseases hiv aids tuberculosis and malaria which generally receive greater treatment and research funding in sub saharan africa the impact of these diseases as a group is comparable to malaria and tuberculosis ntd co infection can also make hiv aids and tuberculosis more deadly in some cases the treatments are relatively inexpensive for example the treatment for schistosomiasis is us 0 20 per child per year nevertheless control of neglected diseases is estimated to require funding of between us 2 billion to us 3 billion over the next five to seven years some pharmaceutical companies have committed to donating all the drug therapies required and mass drug administration for example mass deworming has been successfully accomplished in several countries however preventative measures are often more accessible in the developed world but not universally available in poorer areas seventeen neglected tropical diseases are prioritized by who though other organizations define ntds differently these diseases are common in 149 countries affecting more than 1 4 billion people including more than 500 million children and costing developing economies billions of dollars every year they resulted in 142 000 deaths in 2013 — down from 204 000 deaths in 1990 of these 17 two were targeted for eradication dracunculiasis guinea worm disease by 2015 and yaws by 2020 and four for elimination blinding trachoma human african trypanosomiasis leprosy and lymphatic filariasis by 2020
negligent entrustment is a cause of action in tort law that arises where one party the entrustor is held liable for negligence because they negligently provided another party the entrustee with a dangerous instrumentality and the entrusted party caused injury to a third party with that instrumentality the cause of action most frequently arises where one person allows another to drive their automobile
the tort of negligent infliction of emotional distress nied is a controversial cause of action which is available in nearly all u s states but is severely constrained and limited in the majority of them the underlying concept is that one has a legal duty to use reasonable care to avoid causing emotional distress to another individual if one fails in this duty and unreasonably causes emotional distress to another person that actor will be liable for monetary damages to the injured individual the tort is to be contrasted with intentional infliction of emotional distress in that there is no need to prove intent to inflict distress that is an accidental infliction if negligent is sufficient to support a cause of action
negligible senescence is the lack of symptoms of aging in a few select organisms negligibly senescent organisms do not have measurable reductions in their reproductive capability with age or measurable functional decline with age death rates in negligibly senescent organisms do not increase with age as they do in senescent organisms there are many examples of species for whose organisms scientists have not detected an increase in mortality rate after maturity in other words they are equally likely to die at any given age after maturity or alternatively it could be that the mean lifespan of the organisms is so long — several millennia — that researchers subjects have not yet had the chance to live up to the time when a measure of the species longevity can be made turtles for example were once thought to lack senescence however more extensive observations have found evidence of decreasing fitness with age study of negligibly senescent animals may provide clues that lead to better understanding of the aging process and influence theories of aging the phenomenon of negligible senescence in some animals is a traditional argument for attempting to achieve similar negligible senescence in humans by technological means there are also organisms that exhibit negative senescence whereby mortality chronologically decreases as the organism ages for all or part of the life cycle in disagreement with the gompertz – makeham law of mortality see also late life mortality deceleration furthermore there are even more peculiar examples those of species that have been observed to regress to a larval state and regrow into adults multiple times e g turritopsis dohrnii recent studies have indicated a connection between phenomena related to negligible senescence and the general stability of an organism s genome specifically transcription processes over its lifetime
the first case of nelson ’ s syndrome was reported in 1958 by nelson et al dr don nelson an endocrinologist named the disease in comparison to the 1980 s there have been fewer published cases in the 1990 s thus nelson ’ s syndrome has become less prevalent the disease becoming less prevalent is supported by much advancement in the medical field within the past ten to twenty years improvements have been made with identification and care for patients with cushing ’ s disease improvements have been made with techniques such as pituitary radiation therapy acth assay transsphenoidal pituitary surgery higher resolution mris and sampling of the inferior petrosal sinus the advancements mentioned prior are what have allowed physicians to pursue other routes for cushing ’ s disease therapy that don ’ t involve bilateral adrenalectomy nelson ’ s syndrome is also referred to as post adrenalectomy syndrome and is a result of an adrenalectomy performed for cushing ’ s disease corticotroph adenomas are detected in more females than males therefore nelson ’ s syndrome is observed in more females than males corticotroph adenomas are also detected in the younger population compared to the older population earlier nelson s syndrome was observed in 20 40 of patients who had a bilateral adrenalectomy with a pituitary adenoma nelson s syndrome is observed in 8 44 of the population who have undergone bilateral adrenalectomy treatment for cushing s disease
nemaline myopathy also called rod myopathy or nemaline rod myopathy is a congenital hereditary neuromuscular disorder with many symptoms that can occur such as muscle weakness hypoventilation swallowing dysfunction and impaired speech ability the severity of these symptoms varies and can change throughout one s life to some extent the prevalence is estimated at 1 in 50 000 live births it is the most common non dystrophic myopathy myopathy means muscle disease muscle fibers from a person with nemaline myopathy contains thread like rods sometimes called nemaline bodies while the rods are diagnostic of the disorder they are more likely a byproduct of the disease process rather than causing any dysfunction on their own people with nemaline myopathy nm usually experience delayed motor development or no motor development in severe cases and weakness may occur in all of the skeletal muscles such as muscles in the arms legs torso neck flexors throat and face the weakness tends to be more severe in the proximal muscles rather than the distal muscles the ocular muscles are normally spared the disorder is often clinically categorized into groups with wide ranges of overlapping severity from the most severe neonatal form which is incompatible with life to a form so mild that it may not be diagnosed since the person appears to function at the lowest end of normal strength and breathing adequacy sporadic late onset nemaline myopathy slonm is not a congenital disorder and is considered a different muscle disease from nm which has its onset at birth or early childhood respiratory problems are usually a primary concern for people with all forms of nm and respiratory infections are quite common nm shortens life expectancy particularly in the more severe forms but aggressive and proactive care allows most individuals to survive and even lead active lives nemaline myopathy is one of the neuromuscular diseases covered by the muscular dystrophy association in the united states
nematode dermatitis is a cutaneous condition characterized by widespread folliculitis caused by ancylostoma caninum
the nenitzescu indole synthesis is a chemical reaction that forms 5 hydroxyindole derivatives from benzoquinone and β aminocrotonic esters the nenitzescu indole synthesis this reaction was named for its discoverer who first published it in 1929 it can be performed with a number of different combinations of r groups which include methyl methoxy ethyl propyl and h substituents there is also a solid state variation in which the reaction takes place on a highly cross linked polymer scaffold the synthesis is particularly interesting because indoles are the foundation for a number of biochemically important molecules including neurotransmitters and a new class of antitumor compounds
neomodern or neomodernist art is a reaction to the complexity of postmodern architecture and eclecticism seeking greater simplicity
neonatal acne also known as acne infantum acne neonatorum and neonatal cephalic pustulosis not to be confused with benign cephalic histiocytosis is an acneiform eruption that occurs in newborns or infants and is often seen on the nose and adjacent portions of the cheeks the main cause of this condition is not known but it could be due to the increased sensitivity of the infant s sebaceous glands to maternal hormones during pregnancy which also leads to a variety of skin conditions in the newborn typically it peaks at around 2 months and rarely needs treatment sometimes gels or ointments are given
neonatal adrenoleukodystrophy is an inborn error of peroxisome biogenesis it is part of the zellweger spectrum it has been linked with multiple genes at least five associated with peroxisome biogenesis and has an autosomal recessive pattern of inheritance
neonatal alloimmune thrombocytopenia naitp or nait or natp or nat for short or fetal and neonatal alloimmune thrombocytopenia fnait feto maternal alloimmune thrombocytopenia fmaitp or fmait is a disease that affects fetuses and newborns in which the platelet count is decreased a state known as thrombocytopenia platelet antigens are inherited from both mother and father fnait is caused by antibodies specific for platelet antigens inherited from the father but which are absent in the mother fetomaternal transfusions or fetomaternal hemorrhage results in the recognition of these antigens by the mother s immune system as non self with the subsequent generation of allo reactive antibodies which cross the placenta nait hence is caused by transplacental passage of maternal platelet specific alloantibody and rarely human leukocyte antigen hla allo antibodies which are expressed by platelets to fetuses whose platelets express the corresponding antigens nait occurs in somewhere between 1 800 and 1 5000 live births more recent studies of nait seem to indicate that it occurs in around 1 600 live births in the caucasian population
neonatal bowel obstruction nbo or neonatal intestinal obstruction is the most common surgical emergency in the neonatal period it may occur due to a variety of conditions and has an excellent outcome based on timely diagnosis and appropriate intervention
neonatal cholestasis defines persisting conjugated hyperbilirubinemia in the newborn with conjugated bilirubin levels exceeding 15 5 0 mg dl of total bilirubin level the disease is either due to defects in bile excretion from hepatocytes or impaired bile flow general presentations in neonates include abdominal pain and general gi upset physical examination may show palpable liver and enlarged spleen differential diagnosis typically presents with a host of possibilities many of them not treatable histopathology shows dilated bile duct system at all levels and bile duct proliferation in response to back pressure the incidence has been found to be about 1 2 500 live births
neonatal conjunctivitis also known as ophthalmia neonatorum is a form of conjunctivitis and a type of neonatal infection contracted by newborns during delivery the baby s eyes are contaminated during passage through the birth canal from a mother infected with either neisseria gonorrhoeae or chlamydia trachomatis antibiotic ointment is typically applied to the newborn s eyes within 1 hour of birth as prevention against gonococcal ophthalmia if left untreated it can cause blindness
neonatal encephalopathy ne also known as hypoxic ischemic encephalopathy hie is defined by signs and symptoms of abnormal neurological function in the first few days of life in an infant born at term it is commonly caused by birth asphyxia
neonatal hemochromatosis is a rare and severe liver disease of unknown origin though research suggests that it may be alloimmune condition its characteristics are similar to hereditary hemochromatosis where iron deposition causes damage to the liver and other organs and tissues
neonatal hepatitis is a form of hepatitis that affects the fetuses and neonates
neonatal herpes simplex is a rare but serious condition usually caused by vertical transmission of herpes simplex virus from mother to newborn around 1 in every 3 500 babies in the united states contract the infection
neonatal hypocalcemia is an abnormal clinical and laboratory hypocalcemia condition that is frequently observed in infants 1 healthy term infants go through a physiological nadir of serum calcium levels at 7 5 8 5 mg dl by day 2 of life hypocalcemia is a low blood calcium level a total serum calcium of less than 8 mg dl 2 mmol l or ionized calcium less than 1 2 mmol l in term neonates is defined as hypocalcemia in preterm infants it is defined as less than 7 mg dl 1 75 mmol l total serum calcium or less than 4 mg dl 1 mmol l ionized calcium 2 both early onset hypocalcemia presents within 72 h of birth and late onset hypocalcemia presents in 3 7 days after birth require calcium supplementation treatment risk factors of early neonatal hypocalcemia prematurity perinatal asphyxia diabetes mellitus in the mother maternal hyperparathyroidism intrauterine growth retardation iugr iatrogenic risk factors of late neonatal hypocalcemia exogenous phosphate load use of gentamicin gender and ethnic late neonatal hypocalcemia occurred more often in male infants and hispanic infants others magnesium deficiency transient hypoparathyroidism of newborn hypoparathyroidism due to other causes digeorge syndrome
neonatal hypoglycemia is a condition of decreased blood sugar or hypoglycemia in a neonate untreated low blood sugar levels in newborn children poses a higher risk for injury to the brain that could lead to developmental problems later in life such children are often admitted to neonatal units for active treatment resulting in separation from the mother and inadequate breast feeding during this time
neonatal ichthyosis – sclerosing cholangitis syndrome also known as nisch syndrome and ichthyosis – sclerosing cholangitis syndrome is a cutaneous condition caused by mutations in the claudin 1 gene
neonatal infections are infections of the neonate newborn during the neonatal period or first four weeks after birth neonatal infections may be contracted by transplacental transfer in utero in the birth canal during delivery perinatal or by other means after birth some neonatal infections are apparent soon after delivery while others may develop postpartum within the first week or month some infections acquired in the neonatal period do not become apparent until much later such as hiv hepatitis b and malaria there is a higher risk of infection with preterm or low birth weight neonates respiratory tract infections contracted by preterm neonates may continue into childhood or possibly adulthood with long term effects that limit one s ability to engage in normal physical activities decreasing one s quality of life and increasing health care costs in some instances neonatal respiratory tract infections may increase one s susceptibility to future respiratory infections and inflammatory responses related to lung disease antibiotics can be effective treatments for neonatal infections especially when the pathogen is quickly identified instead of relying solely on culturing techniques pathogen identification has improved substantially with advancing technology however neonate mortality has not kept pace and remains 20 to 50 while preterm neonates are at a particularly high risk full term and post term infants can also develop infection neonatal infection may also be associated with premature rupture of membranes breakage of the amniotic sac which substantially increases the risk of neonatal sepsis by allowing passage for bacteria to enter the womb prior to the birth of the infant research to improve treatment of infections and prophylactic treatment of the mother to avoid infections of the infant is ongoing
neonatal isoerythrolysis also known as hemolytic icterus is a disease most commonly seen in kittens and foals but has also been reported in puppies in the kitten this is referred to as fading kitten syndrome it occurs when the mother has antibodies against the blood type of the newborn
neonatal jaundice or neonatal hyperbilirubinemia or neonatal icterus from the greek word ἴκτερος attributive adjective icteric is a yellowing of the skin and other tissues of a newborn infant a bilirubin level of more than 85 μmol l 5 mg dl leads to a jaundiced appearance in neonates whereas in adults a level of 34 μmol l 2 mg dl is needed for this to occur in newborns jaundice is detected by blanching the skin with pressure applied by a finger so that it reveals underlying skin and subcutaneous tissue jaundiced newborns have yellow discoloration of the white part of the eye and yellowing of the face extending down onto the chest neonatal jaundice can make the newborn sleepy and interfere with feeding extreme jaundice can cause permanent brain damage from kernicterus in neonates the yellow discoloration of the skin is first noted in the face and as the bilirubin level rises proceeds caudal to the trunk and then to the extremities this condition is common in newborns affecting over half 50 – 60 of all babies in the first week of life infants whose palms and soles are yellow have serum bilirubin level over 255 μmol l 15 mg dl more serious level studies have shown that trained examiners assessment of levels of jaundice show moderate agreement with icterometer bilirubin measurements in infants jaundice can be measured using invasive or non invasive methods
neonatal lupus erythematosus is the occurrence of systemic lupus erythematosus sle symptoms in an infant born from a mother with sle most commonly presenting with a rash resembling discoid lupus erythematosus and sometimes with systemic abnormalities such as complete heart block or hepatosplenomegaly the infants have no skin lesions at birth but develop them during the first weeks of life neonatal lupus is usually benign and self limited it is associated with mothers who carry the ro ssa antibodies
neonatal meningitis is a serious medical condition in infants meningitis is an inflammation of the meninges the protective membranes of the central nervous system cns and is more common in the neonatal period infants less than 44 days old than any other time in life and is an important cause of morbidity and mortality globally mortality is roughly half in developing countries and ranges from 8 12 5 in developed countries symptoms seen with neonatal meningitis are often unspecific that may point to several conditions such as sepsis whole body inflammation these can include fever irritability and dyspnea the only method to determine if meningitis is the cause of these symptoms is lumbar puncture lp an examination of the cerebrospinal fluid the most common causes of neonatal meningitis is bacterial infection of the blood known as bacteremia specifically group b streptococci gbs streptococcus agalactiae escherichia coli and listeria monocytogenes although there is a low mortality rate in developed countries there is a 50 prevalence rate of neurodevelopmental disabilities in e coli and gbs meningitis while having a 79 prevalence for non e coli gram negative caused meningitis delayed treatment of neonatal meningitis may cause include cerebral palsy blindness deafness and learning deficiencies
neonatal onset multisystem inflammatory disease abbreviated nomid also known as chronic infantile neurologic cutaneous and articular syndrome or cinca is a rare genetic periodic fever syndrome which causes uncontrolled inflammation in multiple parts of the body starting in the newborn period symptoms include skin rashes severe arthritis and chronic meningitis leading to neurologic damage it is one of the cryopyrin associated periodic syndromes nomid can result from a mutation in the cias 1 gene also known as nlrp 3 gene which helps control inflammation mutations in this gene also cause familial cold urticaria and muckle wells syndrome nomid has been successfully treated with the drug anakinra this syndrome is also known as the prieur griscelli syndrome as it was first described by these authors in 1981
neonatal sepsis is a type of neonatal infection and specifically refers to the presence in a newborn baby of a bacterial blood stream infection bsi such as meningitis pneumonia pyelonephritis or gastroenteritis in the setting of fever older textbooks may refer to neonatal sepsis as sepsis neonatorum criteria with regards to hemodynamic compromise or respiratory failure are not useful clinically because these symptoms often do not arise in neonates until death is imminent and unpreventable neonatal sepsis is divided into two categories early onset sepsis eos and late onset sepsis los eos refers to sepsis presenting in the first 7 days of life although some refer to eos as within the first 72 hours of life with los referring to presentation of sepsis after 7 days or 72 hours depending on the system used neonatal sepsis is the single most important cause of neonatal death in hospital as well as community in developing country it is difficult to clinically exclude sepsis in newborns less than 90 days old that have fever defined as a temperature 38 ° c 100 4 ° f except in the case of obvious acute viral bronchiolitis the current practice in newborns less than 30 days old is to perform a complete workup including complete blood count with differential blood culture urinalysis urine culture and cerebrospinal fluid csf studies and csf culture admit the newborn to the hospital and treat empirically for serious bacterial infection for at least 48 hours until cultures are demonstrated to show no growth attempts have been made to see whether it is possible to risk stratify newborns in order to decide if a newborn can be safely monitored at home without treatment despite having a fever one such attempt is the rochester criteria
natal teeth are teeth that are present above the gumline have already erupted at birth and neonatal teeth are teeth that emerge through the gingiva during the first month of life the neonatal period the incidence of neonatal teeth varies considerably between 1 700 and 1 30 000 depending on the type of study the highest prevalence is found in the only study that relies on personal examination of patients
neonatal tetanus is a form of generalised tetanus that occurs in newborns infants who have not acquired passive immunity from the mother having been immunised are at risk it usually occurs through infection of the unhealed umbilical stump particularly when the stump is cut with a non sterile instrument neonatal tetanus mostly occurs in developing countries particularly those with the least developed health infrastructure it is rare in developed countries
neonatal toxic shock like exanthematous disease is a cutaneous condition characterized by a generalized diffuse macular erythema or morbilliform eruption with confluence
neonatal withdrawal or neonatal abstinence syndrome nas is a withdrawal syndrome of infants caused by the cessation of the administration of licit or illicit drugs tolerance dependence and withdrawal may occur as a result of repeated administration of drugs or even after short term high dose use — for example during mechanical ventilation in intensive care units there are two types of nas prenatal and postnatal prenatal nas is caused by discontinuation of drugs taken by the pregnant mother while postnatal nas is caused by discontinuation of drugs directly to the infant the drugs involved may be for example opioids selective serotonin reuptake inhibitors ssris ethanol and benzodiazepines neonatal abstinence syndrome does not happen in prenatal cocaine exposure with babies exposed to cocaine in utero in the sense that such symptoms are difficult to separate in the context of other factors such as prematurity or prenatal exposure to other drugs when pharmacological treatment of opiate withdrawal in neonates is deemed necessary opiates are the treatment of choice they are slowly tapered down to wean the neonate off opiates phenobarbital is sometimes used as an alternative but is less effective in suppressing seizures however phenobarbital is superior to diazepam for neonatal opiate withdrawal symptoms in the case of sedative hypnotic neonatal withdrawal phenobarbital is the treatment of choice clonidine is an emerging add on therapy buprenorphine is under development as an alternative to morphine or methadone as initial therapy opioids such as neonatal morphine solution and methadone are commonly used to treat clinical symptoms of opiate withdrawal but may prolong neonatal drug exposure and duration of hospitalization a study published in the journal of pediatric pharmacology and therapeutics demonstrated a significantly shorter wean duration in infants treated with methadone compared to those treated with diluted tincture of opium when compared to morphine methadone has a longer half life in children which allows for less frequent dosing intervals and steady serum concentrations to prevent neonatal withdrawal symptoms non pharmacological approaches to treat neonatal symptoms include swaddling the infant in a blanket minimizing environmental stimuli and monitoring sleeping and feeding patterns breastfeeding promotes infant attachment and bonding and is associated with a decreased need for pharmacological treatment these approaches may lessen the severity of nas and lead to shorter hospital stays a 2012 study from the university of michigan and the university of pittsburgh published in the journal of the american medical association analyzed information on 7 4 million discharges from 4 121 hospitals in 44 states to measure trends and costs associated with nas over the past decade the study indicated that between 2000 and 2009 the number of mothers using opiates increased from 1 19 to 5 63 per 1 000 hospital births per year newborns with nas were 19 more likely than all other hospital births to have low birthweight and 30 more like to have respiratory complications between 2000 and 2009 total hospital charges for nas cases adjusted for inflation are estimated to have increased from 190 million to 720 million
neoplasm is an abnormal growth of tissue and when it also forms a mass is commonly referred to as a tumor this abnormal growth neoplasia usually but not always forms a mass the world health organization who classifies neoplasms into four main groups benign neoplasms in situ neoplasms malignant neoplasms and neoplasms of uncertain or unknown behavior malignant neoplasms are also simply known as cancers prior to the abnormal growth of tissue as neoplasia cells often undergo an abnormal pattern of growth such as metaplasia or dysplasia however metaplasia or dysplasia does not always progress to neoplasia the word is from ancient greek νέος neo new and πλάσμα plasma formation creation
nephritic syndrome or acute nephritic syndrome is a syndrome comprising signs of nephritis which is kidney disease involving inflammation it often occurs in glomerulonephritis which is characterized by a thin glomerular basement membrane and small pores in the podocytes of the glomerulus large enough to permit proteins and red blood cells to pass into the urine yielding proteinuria and hematuria by contrast nephrotic syndrome is characterized by only proteins moving into the urine nephritic syndrome like nephrotic syndrome may involve hypoalbuminemia due to the protein albumin moving from the blood to the urine
nephritis is inflammation of the kidneys and may involve the glomeruli tubules or interstitial tissue surrounding the glomeruli and tubules
nephrocalcinosis once known as albright s calcinosis after fuller albright or anderson carr kidneys is a term originally used to describe deposition of calcium salts in the renal parenchyma due to hyperparathyroidism it is now more commonly used to describe diffuse fine renal parenchymal calcification on radiology during its early stages nephrocalcinosis is visible on x ray and appears as a fine granular mottling over the renal outlines these outlines eventually come together to form a dense mass it is most commonly seen as an incidental finding with medullary sponge kidney on an abdominal x ray however it may be severe enough to cause as well as be caused by renal tubular acidosis or even end stage renal failure due to disruption of the renal tissue by the deposited calcium
nephrogenic adenoma also mesonephric adenoma and nephrogenic metaplasia is a benign growth typically found in the urinary bladder it is thought to result from displacement and implantation of renal tubular cells as this entity in kidney transplant recipients has been shown to be kidney donor derived this entity should not be confused with the similar sounding metanephric adenoma
nephrogenic diabetes insipidus also known as peripheral diabetes insipidus is a form of diabetes insipidus primarily due to pathology of the kidney this is in contrast to central neurogenic diabetes insipidus which is caused by insufficient levels of antidiuretic hormone adh arginine vasopressin avp nephrogenic diabetes insipidus is caused by an improper response of the kidney to adh leading to a decrease in the ability of the kidney to concentrate the urine by removing free water
nephrogenic systemic fibrosis nsf or nephrogenic fibrosing dermopathy nfd is a rare and serious syndrome that involves fibrosis of skin joints eyes and internal organs the first cases were identified in 1997 and its cause is not fully understood however evidence suggests nsf is associated with exposure to gadolinium with gadolinium based mri contrast agents being frequently used as contrast agents for magnetic resonance imaging mri in patients with severe kidney failure epidemiological studies suggest that the incidence of nsf is unrelated to gender race or age and it is not thought to have a genetic basis a registry for nsf has identified about 335 cases as of 2011 most patients with nsf have undergone hemodialysis for kidney failure some have never undergone dialysis and others have received only peritoneal dialysis many people with nsf have taken immunosuppressive medications and have other diseases such as hepatitis c four of the seven gadolinium contrast agents approved by the u s food and drug administration have been principally implicated in nsf including gadodiamide gadopentetate and gadoversetamide gadobenate has also been associated with nsf but further research has shown that gadobenate diglumine might be safe even in patients undergoing dialysis
nephromegaly is the process whereby a kidney or both kidneys become enlarged
nephronophthisis is a genetic disorder of the kidneys which affects children it is classified as a medullary cystic kidney disease the disorder is inherited in an autosomal recessive fashion and although rare is the most common genetic cause of childhood kidney failure it is a form of ciliopathy its incidence has been estimated to be 0 9 cases per million people in the united states and 1 in 50 000 births in canada
nephropathia epidemica ne or epidemic nephropathy is a type of viral haemorrhagic fever with renal syndrome hfrs caused by the puumala virus the incubation period is three weeks nephropathia epidemica has a sudden onset with fever abdominal pain headache back pain and gastrointestinal symptoms more severe symptoms include internal hemorrhaging although fatal in a small percentage of cases nephropathia epidemica is generally milder than the hfrs that is caused by hantaviruses in other parts of the world the bank vole is the reservoir for the virus which humans contract through inhalation of aerosolised vole droppings the majority of infected individuals are asymptomatic or develop only mild symptoms and the disease is not known to spread from human to human this infection is known as sorkfeber in swedish and myyräkuume in finnish vole fever in norway it is called musepest mouse plague
nephroptosis also called floating kidney or renal ptosis is an abnormal condition in which the kidney drops down into the pelvis when the patient stands up it is more common in women than in men it has been one of the most controversial conditions among doctors in both its diagnosis and its treatments
nephrosis is any of various forms of kidney disease nephropathy in an old and broad sense of the term it is any nephropathy but in current usage the term is usually restricted to a narrower sense of nephropathy without inflammation or neoplasia in which sense it is distinguished from nephritis which involves inflammation it is also defined as any purely degenerative disease of the renal tubules nephrosis is characterized by a set of signs called the nephrotic syndrome nephrosis can be a primary disorder or can be secondary to another disorder nephrotic complications of another disorder can coexist with nephritic complications in other words nephrosis and nephritis can be pathophysiologically contradistinguished but that does not mean that they cannot occur simultaneously types of nephrosis include amyloid nephrosis and osmotic nephrosis
nephrotic syndrome is a syndrome comprising signs of nephrosis chiefly proteinuria hypoalbuminemia and edema it is a component of glomerulonephrosis in which different degrees of proteinuria occur essentially loss of protein through the kidneys proteinuria leads to low protein levels in the blood hypoproteinemia including hypoalbuminemia which causes water to be drawn into soft tissues edema very low hypoalbuminemia can also cause a variety of secondary problems such as water in the abdominal cavity ascites around the heart or lung pericardial effusion pleural effusion high cholesterol hence hyperlipidemia loss of molecules regulating coagulation hence increased risk of thrombosis large proteinuria is due to an increase in permeability of the filtering membrane of the kidney which normally separates the blood from the urinary space in bowman s capsule this is composed of the capillary walls of the glomerulus which are wrapped by highly specialized cells called podocytes alterations in their capacity to filter the substances transported in the blood mean that proteins but not cells pass into the urine hence no haematuria by contrast in nephritic syndrome red blood cells pass through the pores causing haematuria
nephrotoxicity is toxicity in the kidneys it is a poisonous effect of some substances both toxic chemicals and medications on renal function there are various forms and some drugs may affect renal function in more than one way nephrotoxins are substances displaying nephrotoxicity nephrotoxicity should not be confused with the fact that some medications have a predominantly renal excretion and need their dose adjusted for the decreased renal function e g heparin the nephrotoxic effect of most drugs is more profound in patients already suffering from kidney failure
nerve compression syndrome or compression neuropathy also known as entrapment neuropathy is a medical condition caused by direct pressure on a nerve it is known colloquially as a trapped nerve though this may also refer to nerve root compression by a herniated disc for example its symptoms include pain tingling numbness and muscle weakness the symptoms affect just one particular part of the body depending on which nerve is affected nerve conduction studies help to confirm the diagnosis in some cases surgery may help to relieve the pressure on the nerve but this does not always relieve all the symptoms nerve injury by a single episode of physical trauma is in one sense a compression neuropathy but is not usually included under this heading
nerve injury is injury to nervous tissue there is no single classification system that can describe all the many variations of nerve injury most systems attempt to correlate the degree of injury with symptoms pathology and prognosis in 1941 seddon introduced a classification of nerve injuries based on three main types of nerve fiber injury and whether there is continuity of the nerve
a nerve sheath tumor is a type of tumor of the nervous system nervous system neoplasm which is made up primarily of the myelin surrounding nerves a peripheral nerve sheath tumor pnst is a nerve sheath tumor in the peripheral nervous system benign peripheral nerve sheath tumors include schwannomas and neurofibromas a malignant peripheral nerve sheath tumor mpnst is a cancerous peripheral nerve sheath tumor
in english law a nervous shock is a psychiatric illness or injury inflicted upon a person by intentional or negligent actions or omissions of another often it is a psychiatric disorder triggered by witnessing an accident for example an injury caused to one s parents or spouse although the term nervous shock has been described as inaccurate and misleading it continues to be applied as a useful abbreviation for a complex concept the possibility of recovering damages for nervous shock particularly caused by negligence is strongly limited in english law
nervous system disease refers to a general class of medical conditions affecting the nervous system they can be divided into central nervous system disease in the cns peripheral neuropathy in the pns
a nervous system neoplasm is a tumor affecting the nervous system types include nerve sheath tumor brain tumor arachnoid cyst optic nerve glioma
in medicine a nesidioblastoma is an uncommon insulin secreting pancreatic neuroendocrine tumor pannet the term dates to at least 1938 in that report these lesions were adjudicated as histologically benign adenoma growths that were associated with severe long standing hypoglycemia due to hyperinsulinism surgical removal corrected the low glucose problems there is no rigorous definitional separation from insulinoma other than the original emphasis that was placed on the observed precise histological recapitulation of normal islet cell structure within the adenomas which lacked microscopic features of aggressivity the functional hypoglycemia seen with these lesions is also a feature of nesidioblastosis in which however a more diffuse hyperplasia of the pancreatic beta cells is found often with an abnormal microscopic appearance
nesidioblastosis is a controversial medical term for hyperinsulinemic hypoglycemia attributed to excessive function of pancreatic beta cells with an abnormal microscopic appearance the term was coined in the first half of the 20 th century the abnormal histologic aspects of the tissue included the presence of islet cell enlargement islet cell dysplasia beta cells budding from ductal epithelium and islets in apposition to ducts by the 1970 s nesidioblastosis was primarily used to describe the pancreatic dysfunction associated with persistent congenital hyperinsulinism and in most cases from the 1970 s until the 1980 s it was used as a synonym for what is now referred to as congenital hyperinsulinism most congenital hyperinsulinism is caused by different mechanisms than excessive proliferation of beta cells in a fetal pattern and the term fell into disfavor after it was recognized in the late 1980 s that the characteristic tissue features were sometimes seen in pancreatic tissue from normal infants and even adults and is not consistently associated with hyperinsulinemic hypoglycemia however the term has been resurrected in recent years to describe a form of acquired hyperinsulinism with beta cell hyperplasia found in adults especially after gastrointestinal surgery evidence of physiologic mechanisms purporting that weight loss surgery conveys the ability to induce a more contemporary presentation of nesidioblastosis remains elusive and is of intense interest to diabetes researchers
in computer programming a nested function or nested procedure or subroutine is a function which is defined within another function the enclosing function due to simple recursive scope rules a nested function is itself invisible outside of its immediately enclosing function but can see access all local objects data functions types etc of its immediately enclosing function as well as of any function s which in turn encloses that function the nesting is theoretically possible to any ideas of depth although only a few levels are normally used in practical programs nested functions are used in many approaches to structured programming including early ones such as algol simula 67 and pascal and also in many modern dynamic languages and functional languages however they are traditionally not supported in the originally simple c family of languages
a net british english nett value is the resultant amount after accounting for the sum or difference of two or more variables in economics it is frequently used to imply the remaining value after accounting for a specific commonly understood deduction in these cases it is contrasted with the term gross which refers to the pre deduction value for example net income is the total income of a company after deducting its expenses — commonly known as profit — or the total income of an individual after deducting his or her income tax profit may be broken down further into pre taxed or gross profit and profit after taxes or net profit similarly an individual s net worth the difference between their assets what they own and their liabilities what they owe to others similarly net investment in physical capital such as machinery equals gross total investment minus the dollar amount of replacement investment that offsets depreciation of pre existing machinery thus giving the change in the amount of machinery available for use likewise net national product equals gross national product minus depreciation
net generation is the amount of electricity generated by a power plant that is transmitted and distributed for consumer use net generation is less than the total gross power generation as some power produced is consumed within the plant itself to power auxiliary equipment such as pumps motors and pollution control devices thus net generation gross generation − usage within the plant a k a in house loads
net interest income nii is the difference between revenues generated by interest bearing assets and the cost of servicing interest burdened liabilities for banks the assets typically include commercial and personal loans mortgages construction loans and investment securities the liabilities consist primarily of customers deposits nii is the difference between a interest payments the bank receives on loans outstanding and b interest payments the bank makes to customers on their deposits nii interest payments on assets − interest payments on liabilities depending on a bank s specific assets and liabilities e g fixed or floating rate nii may be more or less sensitive to changes in interest rates if the bank s liabilities reprice faster than its assets then it is said to be liability sensitive further the bank is asset sensitive if its liabilities reprice more slowly than its assets in a changing interest rate environment the exposure of nii to changes in interest rates can be measured by the dollar maturity gap dmg which is the difference between the dollar amount of assets that reprice and the dollar amount of liabilities that reprice within a given time period
net migration rate is the difference of immigrants and emigrants of an area in a period of time divided usually per 1 000 inhabitants considered on midterm population a positive value represents more people entering the country than leaving it while a negative value means more people leaving than entering it
netherton syndrome is a severe autosomal recessive form of ichthyosis associated with mutations in the spink 5 gene it is named after earl w netherton 1910 – 1985 an american dermatologist who discovered it in 1958
a network centric organization is a network governance pattern emerging in many progressive 21 st century enterprises this implies new ways of working with consequences for the enterprise ’ s infrastructure processes people and culture
network load balancing commonly referred to as dual wan routing or multihoming is the ability to balance traffic across two wan links without using complex routing protocols like bgp this capability balances network sessions like web email etc over multiple connections in order to spread out the amount of bandwidth used by each lan user thus increasing the total amount of bandwidth available for example a user has a single wan connection to the internet operating at 1 5 mbit s they wish to add a second broadband cable dsl wireless etc connection operating at 2 5 mbit s this would provide them with a total of 4 mbit s of bandwidth when balancing sessions session balancing does just that it balances sessions across each wan link when web browsers connect to the internet they commonly open multiple sessions one for the text another for an image another for some other image etc each of these sessions can be balanced across the available connections an ftp application only uses a single session so it is not balanced however if a secondary ftp connection is made then it may be balanced so that on the whole traffic is evenly distributed across the various connections and thus provides an overall increase in throughput additionally network load balancing is commonly used to provide network redundancy so that in the event of a wan link outage access to network resources is still available via the secondary link s redundancy is a key requirement for business continuity plans and generally used in conjunction with critical applications like vpns and voip finally most network load balancing systems also incorporate the ability to balance both outbound and inbound traffic inbound load balancing is generally performed via dynamic dns which can either be built into the system or provided by an external service or system having the dynamic dns service within the system is generally thought to be better from a cost savings and overall control point of view
in economics and business a network effect also called network externality or demand side economies of scale is the effect that one user of a good or service has on the value of that product to other people when a network effect is present the value of a product or service is dependent on the number of others using it the classic example is the telephone the more people who own telephones the more valuable the telephone is to each owner this creates a positive externality because a user may purchase a telephone without intending to create value for other users but does so in any case online social networks work in the same way with sites like twitter and facebook becoming more attractive as more users join the expression network effect is applied most commonly to positive network externalities as in the case of the telephone negative network externalities can also occur where more users make a product less valuable but are more commonly referred to as congestion as in traffic congestion or network congestion over time positive network effects can create a bandwagon effect as the network becomes more valuable and more people join in a positive feedback loop
networked feminism is a phenomenon that can be described as the online mobilization and coordination of feminists in response to perceived sexist misogynistic racist and other discriminatory acts against minority groups this phenomenon covers all possible definitions of what feminist movements may entail as there have been multiple waves of feminist movements and there is no central authority to control what the term feminism claims to be while one may hold a different opinion from another on the definition of feminism all those who believe in these movements and ideologies share the same goal of dismantling the current patriarchal social structure where men hold primary power and higher social privileges above all others networked feminism is not spearheaded by one singular women s group rather it is the manifestation of feminists ability to leverage the internet to make traditionally unrepresented voices and viewpoints heard networked feminism occurs when social network sites such as facebook twitter and tumblr are used as a catalyst in the promotion of feminist equality and in response to sexism users of these social media websites promote the advancement of feminism using tools such as viral facebook groups and hashtags these tools are used to push gender equality and call attention to those promoting anything otherwise online feminist work is becoming a new engine of contemporary feminism with the possibility of connecting and communicating all around the world through the internet no other form of activism in history has brought together and empowered so many people to take action on a singular issue
neu – laxova syndrome also known as neu syndrome or neu povysilová syndrome abbreviated as nls is a rare autosomal recessive disorder characterized by severe intrauterine growth restriction and multiple congenital malformations neu – laxova syndrome is a very severe disorder leading to stillbirth or neonatal death it was first described by dr richard neu in 1971 and dr renata laxova in 1972 as a lethal disorder in siblings with multiple malformations neu – laxova syndrome is an extremely rare disorder with less than 100 cases reported in medical literature
neural backpropagation is the phenomenon in which the action potential of a neuron creates a voltage spike both at the end of the axon normal propagation and back through to the dendritic arbor or dendrites from which much of the original input current originated it has been shown that this simple process can be used in a manner similar to the backpropagation algorithm used in multilayer perceptrons a type of artificial neural network in addition to active backpropagation of the action potential there is also passive electrotonic spread while there is ample evidence to prove the existence of backpropagating action potentials the function of such action potentials and the extent to which they invade the most distal dendrites remains highly controversial
synesthesia is a neurological condition in which two or more bodily senses are coupled for example in a form of synesthesia known as grapheme → color synesthesia letters or numbers may be perceived as inherently colored in another called number → form synesthesia numbers are automatically and consistently associated with locations in space in yet another form of synesthesia called ordinal linguistic personification either numbers days of the week or months of the year evoke personalities in other forms of synesthesia music and other sounds may be perceived as colored or having particular shapes recent research has begun to explore the neural basis of these experiences drawing both on neuroscientific principles and on functional neuroimaging data based on these data two major theories have been proposed concerning the neural basis of synesthesia both theories start from the observation that there are dedicated regions of the brain that are specialized for certain functions for example the part of the human brain involved in processing visual input called the visual cortex can be further subdivided into regions that are preferentially involved in color processing the fourth visual area v 4 or with motion processing called v 5 or mt based on this notion of specialized regions some researchers have suggested that increased cross talk between different regions specialized for different functions may account for different types of synesthesia
the neural efficiency hypothesis is the phenomenon where smarter individuals show lower more efficient brain activation than less bright individuals on cognitive tests of low to moderate difficulty for tasks of higher difficulty however smarter individuals show higher brain activation
neural facilitation also known as paired pulse facilitation ppf is a phenomenon in neuroscience in which postsynaptic potentials psps epps or epsps evoked by an impulse are increased when that impulse closely follows a prior impulse ppf is thus a form of short term synaptic plasticity the mechanisms underlying neural facilitation are exclusively pre synaptic broadly speaking ppf arises due to increased presynaptic ca 2 concentration leading to a greater release of neurotransmitter containing synaptic vesicles neural facilitation may be involved in several neuronal tasks including simple learning information processing and sound source localization
neural fibrolipoma is an overgrowth of fibro fatty tissue along a nerve trunk that often leads to nerve compression
neural tube defects ntds are a group of conditions in which an opening in the spinal cord or brain remains from early in human development in the 3 rd week of pregnancy called gastrulation specialized cells on the dorsal side of the embryo begin to change shape and form the neural tube when the neural tube does not close completely an ntd develops specific types include spina bifida which affects the spine anencephaly which results in little to no brain encephalocele which affects the skull and iniencephaly which results in severe neck problems ntds are one of the most common birth defects affecting over 300 000 births each year worldwide for example spina bifida affects approximately 1 500 births annually in the usa or about 3 5 in every 10 000 0 035 of us births which has decreased from around 5 per 10 000 0 05 of us births since folate fortification was started the number of deaths in the usa each year due to neural tube defects also declined from 1 200 before folate fortification was started to 840
neuralgia greek neuron nerve algos pain is pain in the distribution of a nerve or nerves as in intercostal neuralgia trigeminal neuralgia and glossopharyngeal neuralgia
neurapraxia is a disorder of the peripheral nervous system in which there is a temporary loss of motor and sensory function due to blockage of nerve conduction usually lasting an average of six to eight weeks before full recovery neurapraxia is derived from the word apraxia meaning “ loss or impairment of the ability to execute complex coordinated movements without muscular or sensory impairment ” this condition is typically caused by a blunt neural injury due to external blows or shock like injuries to muscle fibers and skeletal nerve fibers which leads to repeated or prolonged pressure buildup on the nerve as a result of this pressure ischemia occurs a neural lesion results and the human body naturally responds with edema extending in all directions from the source of the pressure this lesion causes a complete or partial action potential conduction block over a segment of a nerve fiber and thus a reduction or loss of function in parts of the neural connection downstream from the lesion leading to muscle weakness neurapraxia results in temporary damage to the myelin sheath but leaves the nerve intact and is an impermanent condition thus wallerian degeneration does not occur in neurapraxia in order for the condition to be considered neurapraxia according to the seddon classification system of peripheral nerve injury there must be a complete and relatively rapid recovery of motor and sensory function once nerve conduction has been restored otherwise the injury would be classified as axonotmesis or neurotmesis thus neurapraxia is the mildest classification of peripheral nerve injury neurapraxia is very common in professional athletes especially american football players and is a condition that can and should be treated by a physician
neurasthenia is a term that was first used at least as early as 1829 to label a mechanical weakness of the actual nerves rather than the more metaphorical nerves referred to by george miller beard later as a psychopathological term neurasthenia was used by beard in 1869 to denote a condition with symptoms of fatigue anxiety headache heart palpitations high blood pressure neuralgia and depressed mood neurasthenia is currently a diagnosis in the world health organization s international classification of diseases and the chinese society of psychiatry s chinese classification of mental disorders however it is no longer included as a diagnosis in the american psychiatric association s diagnostic and statistical manual of mental disorders americans were said to be particularly prone to neurasthenia which resulted in the nickname americanitis popularized by william james another rarely used term for neurasthenia is nervosism
neuro immune dysfunction syndrome is a classification of autoimmune disorders proposed by dr michael j goldberg that might explain some cognitive deficiencies in some patients diagnosed with autism dr goldberg through the neuro immune dysfunction syndromes nids research and treatment institute advocates for testing and consultation with autoimmune specialists nutrition specialists and occupational therapists to systematically test for heighten immune response and reduce environmental triggers that may interfere with cognitive function he then advocates rehabilitative therapy to teach social and vocational skills that may be lacking once the reduced inflammation allows more normal cognitive function the nids institutes openly states that it is primarily a network of parents advocating for more research into potential environmental causes of symptoms diagnosed as autism
neuroacanthocytosis is a label applied to several neurological conditions in which the blood contains misshapen spiculated red blood cells called acanthocytes the core neuroacanthocytosis syndromes in which acanthocytes are a typical feature are chorea acanthocytosis and mcleod syndrome acanthocytes are seen less frequently in other conditions including huntington s disease like syndrome 2 hdl 2 and pantothenate kinase associated neurodegeneration pkan the neuroacanthocytosis syndromes are caused by a range of genetic mutations and produce a variety of clinical features but primarily produce neurodegeneration of the brain specifically the basal ganglia the diseases are hereditary but rare
neuroblastoma nb is the most common extracranial solid cancer in childhood and the most common cancer in infancy with an incidence of about 650 cases per year in the u s and 100 cases per year in the uk nearly half of neuroblastoma cases occur in children younger than two years it is a neuroendocrine tumor arising from any neural crest element of the sympathetic nervous system sns it most frequently originates in one of the adrenal glands but can also develop in nerve tissues in the neck chest abdomen or pelvis neuroblastoma is one of the few human malignancies known to demonstrate spontaneous regression from an undifferentiated state to a completely benign cellular appearance it is a disease exhibiting extreme heterogeneity and is stratified into three risk categories low intermediate and high risk low risk disease is most common in infants and good outcomes are common with observation only or surgery whereas high risk disease is difficult to treat successfully even with the most intensive multi modal therapies available esthesioneuroblastoma also known as olfactory neuroblastoma is believed to arise from the olfactory epithelium and its classification remains controversial however since it is not a sympathetic nervous system malignancy esthesioneuroblastoma is a distinct clinical entity and is not to be confused with neuroblastoma
neuroborreliosis is a disorder of the central nervous system caused by infection with a spirochete of the genus borrelia the microbiological progression of the disease is similar to that of neurosyphilis another spirochetal infection
neurocutaneous melanosis is a congenital disorder characterized by the presence of congenital melanocytic nevi on the skin and melanocytic tumors in the leptomeninges of the central nervous system these lesions may occur in the amygdala cerebellum cerebrum pons and spinal cord of patients although typically asymptomatic malignancy occurs in the form of leptomeningeal melanoma in over half of patients regardless of the presence of malignancy patients with symptomatic neurocutaneous melanosis generally have a poor prognosis with few treatment options the pathogenesis of neurocutaneous melanosis is believed to be related to the abnormal postzygotic development of melanoblasts and mutations of the nras gene
neurocytoma or neuroepithelioma is a type of nervous system tumor which is primarily derived from nervous tissue this is in contrast to the gliomas such as oligodendroglioma which are derived from glial cells which are not derived from nervous tissue
neurodegeneration is the umbrella term for the progressive loss of structure or function of neurons including death of neurons many neurodegenerative diseases including amyotrophic lateral sclerosis parkinson s alzheimer s and huntington s occur as a result of neurodegenerative processes such diseases are incurable resulting in progressive degeneration and or death of neuron cells as research progresses many similarities appear that relate these diseases to one another on a sub cellular level discovering these similarities offers hope for therapeutic advances that could ameliorate many diseases simultaneously there are many parallels between different neurodegenerative disorders including atypical protein assemblies as well as induced cell death neurodegeneration can be found in many different levels of neuronal circuitry ranging from molecular to systemic
a neuroectodermal tumor is a tumor of the central or peripheral nervous system
neuroendocrine adenoma of the middle ear name is a tumor which arises from a specific anatomic site middle ear name is a benign glandular neoplasm of middle ear showing histologic and immunohistochemical neuroendocrine and mucin secreting differentiation biphasic or dual differentiation
neuroendocrine tumors nets are neoplasms that arise from cells of the endocrine hormonal and nervous systems many are benign while some are malignant they most commonly occur in the intestine where they are often called carcinoid tumors but they are also found in the pancreas lung and the rest of the body although there are many kinds of nets they are treated as a group of tissue because the cells of these neoplasms share common features such as looking similar having special secretory granules and often producing biogenic amines and polypeptide hormones
neuroferritinopathy or adult onset basal ganglia disease is a genetic neurodegenerative disorder characterized by the accumulation of iron in the basal ganglia cerebellum and motor cortex of the human brain symptoms which are extrapyramidal in nature progress slowly and generally do not become apparent until adulthood these symptoms include chorea dystonia and cognitive deficits which worsen with age this disorder is autosomal dominant and is caused by mutations in the gene encoding the light chain subunit of the ferritin protein wild type ferritin functions as a buffer for iron sequestering it and controlling its release thus mutations in the light chain of ferritin result in the accumulation of iron in the brain which can be imaged using mri currently neuroferritinopathy is the only neurodegenerative disease with an iron accumulation in the brain classified as an autosomal dominant syndrome treatment of neuroferritinopathy is focused on managing symptoms associated with chorea and dystonia using standard medications for each the disorder is progressive and symptoms become worse with age fewer than 100 cases of neuroferritinopathy have been reported since its identification in 2001 its incidence has been largely localized to northeast england suggesting a founder effect due to its genetic nature current research is focused on therapeutic management of the symptoms caused by the disorder
a neurofibroma is a benign nerve sheath tumor in the peripheral nervous system in 90 of cases they re found as stand alone tumors while the remainder are found in persons with neurofibromatosis type i nf 1 an autosomal dominant genetically inherited disease they can result in a range of symptoms from physical disfiguration and pain to cognitive disability neurofibromas arise from nonmyelinating type schwann cells that exhibit biallelic inactivation of the nf 1 gene that codes for the protein neurofibromin this protein is responsible for regulating the ras mediated cell growth signaling pathway in contrast to schwannomas another type of tumor arising from schwann cells neurofibromas incorporate many additional types of cells and structural elements in addition to schwann cells making it difficult to identify and understand all the mechanisms through which they originate and develop
neurofibromatosis nf refers to several genetically inherited conditions that are clinically and genetically different and carry a high possibility of tumor formation this disorder is divided into neurofibromatosis type 1 neurofibromatosis type 2 and schwannomatosis
neurofibromatosis type 3 also known as neurofibromatosis mixed type resembles von recklinghausen s disease but also presents with cutaneous neurofibromas
neurofibromatosis type 4 also known as neurofibromatosis variant type resembles von recklinghausen s disease but also presents with cutaneous neurofibromas this is a new development in the nf family
neurofibromatosis type i nf 1 is a tumor disorder that is caused by the mutation of a gene on chromosome 17 that is responsible for control of cell division nf 1 causes tumors along the nervous system and can grow anywhere on the body nf 1 is one of the most common genetic disorders and is not limited to any person s race or sex currently 2015 there are at least 100 000 people in the u s and about 150 000 people in the uk who have been diagnosed with nf common symptoms of nf 1 include brownish red spots in the colored part of the eye called lisch nodules benign skin tumors called neurofibromas and larger benign tumors of nerves called plexiform neurofibromas scoliosis curvature of the spine learning disabilities vision disorders mental disabilities multiple café au lait tcl name of specifics spots spots and epilepsy nf 1 is a developmental syndrome caused by germline mutations in neurofibromin a gene that is involved in the ras pathway rasopathy due to its rarity and to the fact that genetic diagnosis has been used only in recent years in the past nf 1 was in same cases confused with another syndrome with vaguely similar symptoms the legius syndrome nf 1 is an age specific disease most signs of nf 1 are visible after birth during infancy but many symptoms of nf 1 occur as the person ages and has hormonal changes nf 1 was formerly known as von recklinghausen disease after the researcher friedrich daniel von recklinghausen who first documented the disorder
neurofibromatosis type ii or misme syndrome for multiple inherited schwannomas meningiomas and ependymomas is a genetic condition which may be inherited or may arise spontaneously the main manifestation of the condition is the development of symmetric non malignant brain tumors in the region of the cranial nerve viii which is the auditory vestibular nerve that transmits sensory information from the inner ear to the brain many people with this condition also experience visual problems nf ii is caused by mutations of the merlin gene which seems to influence the form and movement of cells the principal treatments consist of neurosurgical removal of the tumors and surgical treatment of the eye lesions historically the underlying disorder has not had any therapy due to the cell function caused by the genetic mutation however new drug research and some clinical trials have shown some promise in having beneficial effects collaborative research to find better treatments is ongoing such as the work of the synodos nf 2 consortium of scientists
neurogenic bladder dysfunction sometimes simply referred to as neurogenic bladder is a dysfunction of the urinary bladder due to disease of the central nervous system or peripheral nerves involved in the control of micturition urination neurogenic bladder usually causes difficulty or full inability to pass urine without use of a catheter or other method
neurogenic claudication nc also known as pseudoclaudication is a common symptom of lumbar spinal stenosis or inflammation of the nerves emanating from the spinal cord neurogenic means that the problem originates with a problem at a nerve and claudication from the latin for limp because the patient feels a painful cramping or weakness in the legs nc should therefore be distinguished from vascular claudication which is when the claudication stems from a circulatory problem not a neural problem neurogenic claudication can be bilateral or unilateral calf buttock or thigh discomfort pain numbness or weakness in some patients it is precipitated by walking and prolonged standing the pain is classically relieved by a change in position or flexion of the waist and not simply relieved by rest as in vascular claudication therefore patients with neurogenic intermittent claudication have less disability in climbing steps pushing carts and cycling in some patients with severe compression of the nerve roots the nc is not intermittent but painfully persistent the pathophysiology is thought to be ischemia of the lumbosacral nerve roots secondary to compression from surrounding structures hypertrophied facets ligamentum flavum bone spurs scar tissue and bulging or herniated discs in addition to vascular claudication pseudo trochanteric bursitis should be considered in the differential
neurogenic diabetes insipidus more commonly known as central diabetes insipidus is due to a lack of vasopressin production in the brain vasopressin acts to increase the volume of blood intravascularly and decrease the volume of urine produced therefore a lack of it causes increased urine production and volume depletion it is also known as neurohypophyseal diabetes insipidus this condition has only polyuria in common with diabetes and although not mutually exclusive with most typical cases the name diabetes insipidus is a misleading misnomer a better name might be adh deficient polyuria
neurogenic inflammation is inflammation arising from the local release of inflammatory mediators from afferent neurons such as substance p calcitonin gene related peptide cgrp neurokinin a nka and endothelin 3 et 3 trpa 1 channels stimulated by lipopolysaccharide lps may also cause acute neurogenic inflammation once released these neuropeptides induce the release of histamine from adjacent mast cells in turn histamine evokes the release of substance p and calcitonin gene related peptide thus a bidirectional link between histamine and neuropeptides in neurogenic inflammation is established neurogenic inflammation appears to play an important role in the pathogenesis of numerous diseases including migraine psoriasis asthma fibromyalgia eczema rosacea dystonia and multiple chemical sensitivity in migraine stimulation of the trigeminal nerve causes neurogenic inflammation via release of neuropeptides including substance p nitric oxide vasoactive intestinal polypeptide 5 ht neurokinin a and cgrp leading to a sterile neurogenic inflammation
neurogenic shock is a distributive type of shock resulting in low blood pressure occasionally with a slowed heart rate that is attributed to the disruption of the autonomic pathways within the spinal cord it can occur after damage to the central nervous system such as spinal cord injury low blood pressure occurs due to decreased systemic vascular resistance resulting in pooling of blood within the extremities lacking sympathetic tone the slowed heart rate results from unopposed vagal activity and has been found to be exacerbated by hypoxia and endobronchial suction neurogenic shock can be a potentially devastating complication leading to organ dysfunction and death if not promptly recognized and treated it is not to be confused with spinal shock which is not circulatory in nature
neuroinflammation is inflammation of the nervous tissue it may be initiated in response to a variety of cues including infection traumatic brain injury toxic metabolites or autoimmunity in the central nervous system cns including the brain and spinal cord microglia are the resident innate immune cells that are activated in response to these cues the cns is typically an immunologically privileged site because peripheral immune cells are generally blocked by the blood – brain barrier bbb a specialized structure composed of astrocytes and endothelial cells however circulating peripheral immune cells may surpass a compromised bbb and encounter neurons and glial cells expressing major histocompatibility complex molecules perpetuating the immune response although the response is initiated to protect the central nervous system from the infectious agent the effect may be toxic and widespread inflammation as well as further migration of leukocytes through the blood – brain barrier
neuroleptic induced deficit syndrome is a clinical syndrome that develops in some patients who take high doses of an antipsychotic for an extended time time it is most often caused by high potency typical antipsychotics but can also be caused by high doses of many atypicals especially those closer in profile to typical ones that have higher d 2 dopamine receptor affinity and relatively low 5 ht 2 serotonin receptor binding affinity like risperidone and amisulpride
neuroleptic malignant syndrome nms is a life threatening neurological disorder most often caused by an adverse reaction to neuroleptic or antipsychotic drugs nms typically consists of muscle rigidity fever autonomic instability and cognitive changes such as delirium and is associated with elevated plasma creatine phosphokinase the incidence of neuroleptic malignant syndrome has decreased since it was first described due to changes in prescribing habits but nms is still a potential danger to patients being treated with antipsychotic medication because of the unpredictability of nms treatment may vary substantially but is generally based on supportive care and removal of the offending antipsychotic drug
a neurological disorder is any disorder of the body nervous system structural biochemical or electrical abnormalities in the brain spinal cord or other nerves can result in a range of symptoms examples of symptoms include paralysis muscle weakness poor coordination loss of sensation seizures confusion pain and altered levels of consciousness there are many recognized neurological disorders some relatively common but many rare they may be assessed by neurological examination and studied and treated within the specialities of neurology and clinical neuropsychology interventions for neurological disorders include preventative measures lifestyle changes physiotherapy or other therapy neurorehabilitation pain management medication or operations performed by neurosurgeons the world health organization estimated in 2006 that neurological disorders and their sequelae direct consequences affect as many as one billion people worldwide and identified health inequalities and social stigma discrimination as major factors contributing to the associated disability and suffering
a neuroma njuːˈroʊmə plural neuromata or neuromas is a growth or tumor of nerve tissue neuromas tend to be benign i e not cancerous many nerve tumors including those that are commonly malignant are nowadays referred to by other terms neuromas can arise from different types of nervous tissue including the nerve fibers and their myelin sheath as in the case of genuine neoplasms growths like ganglioneuromas and neurinomas the term is also used to refer to any swelling of a nerve even in the absence of abnormal cell growth in particular traumatic neuroma results from trauma to a nerve often during a surgical procedure morton s neuroma affects the foot neuromas can be painful or sometimes as in the case of acoustic neuromas can give rise to other symptoms
neuromuscular disease is a very broad term that encompasses many diseases and ailments that impair the functioning of the muscles either directly being pathologies of the voluntary muscle or indirectly being pathologies of nerves or neuromuscular junctions neuromuscular diseases are those that affect the muscles and or their direct nervous system control problems with central nervous control can cause either spasticity or some degree of paralysis from both lower and upper motor neuron disorders depending on the location and the nature of the problem some examples of central disorders include cerebrovascular accident parkinson s disease multiple sclerosis huntington s disease and creutzfeldt – jakob disease spinal muscular atrophies are disorders of lower motor neuron while amyotrophic lateral sclerosis is a mixed upper and lower motor neuron condition
neuromuscular junction disease is a medical condition where the normal conduction through the neuromuscular junction fails to function correctly
neuromyelitis optica nmo also known as devic s disease or devic s syndrome is a heterogeneous condition consisting of the simultaneous inflammation and demyelination of the optic nerve optic neuritis and the spinal cord myelitis it can be monophasic or recurrent currently at least two different causes are proposed based on the presence of autoantibodies against aqp 4 aqp 4 nmo is currently considered an autoimmune disease autoimmune astrocytopathy or autoimmune astrocytic channelopathy in which a person s own immune system attacks the astrocytes of the optic nerves and spinal cord the cause of the aqp 4 variants is unknown although inflammation may also affect the brain the lesions are different from those observed in the related condition multiple sclerosis spinal cord lesions lead to varying degrees of weakness or paralysis in the legs or arms loss of sensation including blindness and or bladder and bowel dysfunction devic s disease is now studied along a collection of similar diseases called neuromyelitis optica spectrum diseases some cases of this spectrum resemble multiple sclerosis ms in several ways but require a different course of treatment for optimal results in 2004 nmo igg currently known as anti aqp igg was first described leading to the distinction between positive and negative cases in anti aqp positive variants cns astrocytes which are the basis for the glymphatic system are the target of the autoimmune attack nmo igg negative cases are less understood it seems currently that astrocytes are spared in these igg negative cases
neuromyotonia nmt also known as isaacs syndrome and isaacs merton syndrome is a form of peripheral nerve hyperexcitability that causes spontaneous muscular activity resulting from repetitive motor unit action potentials of peripheral origin prevalence is unknown but 100 – 200 cases have been reported so far
neuronal ceroid lipofuscinosis ncl is the general name for a family of at least eight genetically separate neurodegenerative disorders that result from excessive accumulation of lipopigments lipofuscin in the body s tissues these lipopigments are made up of fats and proteins their name comes from the word stem lipo which is a variation on lipid or fat and from the term pigment used because the substances take on a greenish yellow color when viewed under an ultraviolet light microscope these lipofuscin materials build up in neuronal cells and many organs including the liver spleen myocardium and kidneys
neuronal galvanotropism is the ability to direct the outgrowth of neuronal processes through the use of an extracellular electric field this technique has been researched since the late 1920 s and has been shown to direct the formation of both axonic and dendritic processes in cell culture it is only possible to direct outgrowth of in vitro preparations at this point in vitro preparations involve the use of a culture dish in which there is a species specific neuronal growth factor neurons are removed from a chosen animal plated onto the dish and allowed to grow often kept in incubation the application of an extracellular electric field shows that the cells will grow processes in a direction that demonstrates the direction of the applied electric field this could be either in the direction of the cathode or anode depending on the type of substrate the cells are plated onto the mechanism underlying this behavior is thought to involve the effect of the electric field on receptors and membrane proteins on the cell s surface these charged proteins would experience an electrophoretic force pulling them toward the oppositely charged pole of the electric field most of these membrane proteins are negatively charged but the growth when observed appears to be directed to the negative pole cathode this is a strange behavior that can only be accounted for by electroosmotic effects positively charged ions outside the cell experience a force towards the cathode there is a flux of these ions outside the cell and the shear force of solution movement is thought to pull the neurite in the cathodal direction also the electric field may depolarize the cell near the cathodal side opening voltage gated calcium channels and allowing calcium ions to enter the cell calcium is widely believed to be a factor in neurite outgrowth this theory has been challenged in a recent paper by scientists at purdue university recent studies also involve differentiating between the effect of current on growth direction and the effect of a simple electric field studies involving ac and dc fields are also being conducted this is currently a highly researched topic in which many neuroscience labs around the world are attempting to be the first to have a feasible method of directing outgrowth potential applications involve the direction and regeneration of severed nerves although these would only become available in the very distant future this technique would also be useful in the study of neuronal networks neurites could be directed toward each other over large distances and allowed to form synapses networks of hundreds or thousands of cells could be constructed and studied
neuronal tiling is a phenomenon in which multiple arbors of neurons innervate the same surface tissue in a nonredundant and tiled pattern that maximizes coverage of the surface while minimizing overlap between neighbouring arbors hence dendrites of the same neuron spread out by avoiding one another self avoidance moreover dendrites of certain types of neurons such as class iii and class iv dendritic arborization neurons avoid dendrites of neighbouring neurons of the same type tiling whereas dendrites of different neuronal types can cover the same territory coexistence one good example of this organization is the cell bodies of virtually all retinal cell types which are arranged as independent nonrandom mosaics that maximize the distance between neighbouring cells elucidating the mechanisms of process spacing during development is therefore relevant for understanding principles of tissue organization inside and outside of the nervous system
neuropathia mucinosa cutanea is a cutaneous condition characterized by livedo reticularis on the legs and hyperesthesia
neuropathic arthropathy or neuropathic osteoarthropathy also known as charcot joint often charcot foot refers to progressive degeneration of a weight bearing joint a process marked by bony destruction bone resorption and eventual deformity onset is usually insidious if this pathological process continues unchecked it can result in joint deformity ulceration and or superinfection loss of function and in the worst case scenario amputation or death early identification of joint changes is the best way to limit morbidity
neuropathic pain is pain caused by damage or disease affecting the somatosensory nervous system neuropathic pain may be associated with abnormal sensations called dysesthesia or pain from normally non painful stimuli allodynia it may have continuous and or episodic paroxysmal components the latter resemble stabbings or electric shocks common qualities include burning or coldness pins and needles sensations numbness and itching up to 7 to 8 of the european population is affected and in 5 of persons it may be severe neuropathic pain may result from disorders of the peripheral nervous system or the central nervous system brain and spinal cord thus neuropathic pain may be divided into peripheral neuropathic pain central neuropathic pain or mixed peripheral and central neuropathic pain
neuropathy ataxia and retinitis pigmentosa also known as narp syndrome is a rare disease with mitochondrial inheritance that causes a variety of signs and symptoms chiefly affecting the nervous system beginning in childhood or early adulthood most people with narp experience numbness tingling or pain in the arms and legs sensory neuropathy muscle weakness and problems with balance and coordination ataxia many affected individuals also have vision loss caused by changes in the light sensitive tissue that lines the back of the eye the retina in some cases the vision loss results from a condition called retinitis pigmentosa this eye disease causes the light sensing cells of the retina gradually to deteriorate
neurosarcoidosis sometimes shortened to neurosarcoid refers to sarcoidosis a condition of unknown cause featuring granulomas in various tissues involving the central nervous system brain and spinal cord it can have many manifestations but abnormalities of the cranial nerves a group of twelve nerves supplying the head and neck area are the most common it may develop acutely subacutely and chronically approximately 5 10 of people with sarcoidosis of other organs e g lung develop central nervous system involvement only 1 of people with sarcoidosis will have neurosarcoidosis alone without involvement of any other organs diagnosis can be difficult with no test apart from biopsy achieving a high accuracy rate treatment is with immunosuppression the first case of sarcoidosis involving the nervous system was reported in 1948
sexual orientation is an enduring pattern of romantic or sexual attraction or a combination of these to persons of the opposite sex or gender the same sex or gender or to both sexes or more than one gender the ultimate causes and mechanisms of sexual orientation development in humans remain unclear and many theories are speculative and controversial however advances in neuroscience explain and illustrate characteristics linked to sexual orientation studies have explored structural neural correlates functional and or cognitive relationships and developmental theories relating to sexual orientation in humans
neurosis is a class of functional mental disorders involving distress but neither delusions nor hallucinations neurosis should not be mistaken for psychosis which refers to a loss of touch with reality neither should it be mistaken for neuroticism which is a fundamental personality trait according to psychological theory
neurosyphilis is an infection of the brain or spinal cord caused by the spirochete treponema pallidum it usually occurs in people who have had chronic untreated syphilis usually about 10 to 20 years after first infection and develops in about 25 – 40 of persons who are not treated the united states centers for disease control and prevention cdc advises that neurosyphilis can occur at any stage of a syphilis infection
neurothekeoma is a benign cutaneous tumor first described by gallager and helwig who proposed the term in order to reflect the presumed origin of the lesion from nerve sheath microscopically the lesions described closely resembled the tumor “ nerve sheath myxoma ” an entity first described by harkin and reed the latter had through the years been variously described as “ bizarre cutaneous neurofibroma ” “ myxoma of nerve sheath ” and “ pacinian neurofibroma ” clinically neurothekeomas present as a solitary nodule of the skin the most common sites of occurrence are the head and neck and the extremities the lesions range in size from about 0 5 cm to more than 3 cm the average patient age is about 25 years but neurothkeomas may occur at any age women are affected about more often the male to female ratio is approximately 1 2 microscopically neurothekeoma consists of closely aggregated bundles or fascicles of spindle shaped cells the fascicles may or may not have a myxoid background since the time of their first description it has been reported that neurothekeomas are likely not of nerve sheath origin as implied by the term consequently neurothekeoma and nerve sheath myxoma are likely not related histogenetically although they are similar in appearance and in behavior
neurotic excoriations is a condition in which patients produce skin lesions through repetitive compulsive excoriation of their skin
neuroticism is a fundamental personality trait in the study of psychology characterized by anxiety fear moodiness worry envy frustration jealousy and loneliness individuals who score high on neuroticism are more likely than average to experience such feelings as anxiety anger envy guilt and depressed mood they respond more poorly to stressors are more likely to interpret ordinary situations as threatening and minor frustrations as hopelessly difficult they are often self conscious and shy and they may have trouble controlling urges and delaying gratification high neuroticism indexes a risk constellation that exists prior to the development and onset of any of the common mental disorders such as depression phobia panic disorder other anxiety disorders and substance use disorder — symptoms that traditionally have been called neuroses
neutral buoyancy is a condition in which a physical body s average density is equal to the density of the fluid in which it is immersed the buoyancy offsets the force of gravity that would otherwise cause the object to sink if the body s density is greater than the density of the fluid in which it is immersed or rise if it s less an object that has neutral buoyancy will neither sink nor rise in scuba diving the ability to maintain neutral buoyancy through controlled breathing accurate weighting and management of the buoyancy compensator is an important skill a scuba diver maintains neutral buoyancy by continuous correction usually by controlled breathing as neutral buoyancy is an unstable condition for a compressible object in a liquid
neutral lipid storage disease also known as chanarin – dorfman syndrome is an autosomal recessive disorder characterized by accumulation of triglycerides in the cytoplasm of leukocytes muscle liver fibroblasts and other tissues it can be associated with cgi 58
a neutral spine or good posture refers to the three natural curves that are present in a healthy spine looking directly at the front or back of the body the 33 vertebrae in the spinal column should appear completely vertical from a side view the cervical neck region of the spine c 1 c 7 is bent inward the thoracic upper back region t 1 t 12 bends outward and the lumbar lower back region l 1 l 5 bends inward the sacrum tailbone area s 1 s 5 fused and coccyx on average 4 fused rest between the pelvic bones a neutral pelvis indicates the anterior superior iliac spines and pubic symphysis fall in the same vertical line
in chemistry neutralization or neutralisation see spelling differences is a chemical reaction in which an acid and a base react quantitatively with each other in a reaction in water neutralization results in there being no excess of hydrogen or hydroxide ions present in solution the ph of the neutralized solution depends on the acid strength of the reactants neutralization is used in many applications
neutrino oscillation is a quantum mechanical phenomenon whereby a neutrino created with a specific lepton flavor electron muon or tau can later be measured to have a different flavor the probability of measuring a particular flavor for a neutrino varies periodically as it propagates through space first predicted by bruno pontecorvo in 1957 neutrino oscillation has since been observed by a multitude of experiments in several different contexts notably the existence of neutrino oscillation resolved the long standing solar neutrino problem neutrino oscillation is of great theoretical and experimental interest as the precise properties of the process can shed light on several properties of the neutrino in particular it implies that the neutrino has a non zero mass which requires a modification to the standard model of particle physics the experimental discovery of neutrino oscillation and thus neutrino mass by the super kamiokande observatory and the sudbury neutrino observatory was recognized with the 2015 nobel prize for physics
neutron induced swelling is the increase of volume and decrease of density of materials subjected to intense neutron radiation neutrons impacting the material s lattice rearrange its atoms causing buildup of dislocations voids and wigner energy together with the resulting strength reduction and embrittlement it is a major concern for materials for nuclear reactors materials show significant differences in their swelling resistance see also radiation hardening
neutron capture is a nuclear reaction in which an atomic nucleus and one or more neutrons collide and merge to form a heavier nucleus since neutrons have no electric charge they can enter a nucleus more easily than positively charged protons which are repelled electrostatically neutron capture plays an important role in the cosmic nucleosynthesis of heavy elements in stars it can proceed in two ways as a rapid r process or a slow process s process nuclei of masses greater than 56 cannot be formed by thermonuclear reactions i e by nuclear fusion but can be formed by neutron capture
neutropenia or neutropaenia is an abnormally low concentration of neutrophils a type of white blood cell in the blood neutrophils make up the majority of circulating white blood cells and serve as the primary defense against infections by destroying bacteria bacterial fragments and immunoglobulin bound viruses in the blood patients with neutropenia are more susceptible to bacterial infections and without prompt medical attention the condition may become life threatening neutropenic sepsis neutropenia can be acute temporary or chronic long lasting the term is sometimes used interchangeably with leukopenia deficit in the number of white blood cells
neutropenic enterocolitis also known as typhlitis or typhlenteritis and less commonly called caecitis or cecitis is inflammation of the cecum part of the large intestine that may be associated with infection it is particularly associated with neutropenia a low level of neutrophil granulocytes the most common form of white blood cells in the blood
neutrophil specific granule deficiency sgd previously known as lactoferrin deficiency is a rare congenital immunodeficiency characterized by an increased risk for pyogenic infections due to defective production of specific granules and gelatinase granules in patient neutrophils
neutrophil immunodeficiency syndrome is a condition caused by mutations in the rac 2 gene
neutrophilia also called neutrophil leukocytosis or occasionally neutrocytosis is leukocytosis of neutrophils that is a high number of neutrophil granulocytes in the blood
neutrophilic dermatosis of the dorsal hands also known as pustular vasculitis of the dorsal hands is a skin condition that presents with edematous pustular or ulcerative nodules or plaques localized to the dorsal hands
neutrophilic eccrine hidradenitis neh usually is a cutaneous complication of chemotherapy but it can also occur for other reasons it consists of fever and non specific skin lesions it is rare and self limited
neutrophilic lobular panniculitis is a cutaneous condition characterized by inflammation of the subcutaneous fat
in mathematics in the field of complex analysis a nevanlinna function is a complex function which is an analytic function on the open upper half plane h and has non negative imaginary part a nevanlinna function maps the upper half plane to itself or to a real constant but is not necessarily injective or surjective functions with this property are sometimes also known as herglotz pick or r functions
nevoid basal cell carcinoma syndrome nbccs also known as basal cell nevus syndrome multiple basal cell carcinoma syndrome gorlin syndrome and gorlin – goltz syndrome is an inherited medical condition involving defects within multiple body systems such as the skin nervous system eyes endocrine system and bones people with this syndrome are particularly prone to developing a common and usually non life threatening form of non melanoma skin cancer about 10 of people with the condition do not develop basal cell carcinomas bccs the name gorlin syndrome refers to researcher robert j gorlin 1923 – 2006 first described in 1960 nbccs is an autosomal dominant condition that can cause unusual facial appearances and a predisposition for basal cell carcinoma a type of skin cancer which rarely spreads to other parts of the body the prevalence is reported to be 1 case per 56 000 164 000 population recent work in molecular genetics has shown nbccs to be caused by mutations in the ptch patched gene found on chromosome arm 9 q if a child inherits the defective gene from either parent he or she will have the disorder
nevoid hypertrichosis is a cutaneous condition characterized by the growth of terminal hairs in a circumscribed area
nevoid melanoma is a cutaneous condition that may resemble a spitz nevus or an acquired or congenital melanocytic nevus
nevus also known as a mole is the medical term for sharply circumscribed and chronic lesions of the skin or mucosa these lesions are commonly named birthmarks or beauty marks nevi are benign by definition however 25 of malignant melanomas a skin cancer arise from pre existing nevi using the term nevus and nevi loosely most physicians and dermatologists are actually referring to a variant of nevus called the melanocytic nevus which are composed of melanocytes histologically melanocytic nevi are distinguished from lentigines also a type of benign pigmented macule by the presence of nests of melanocytes which lentigines plural form of lentigo lack
nevus anemicus is a congenital disorder characterized by macules of varying size and shape that are paler than the surrounding skin and cannot be made red by trauma cold or heat the paler area is due to the blood vessels within the area which are more sensitive to the body ’ s normal vasoconstricting chemicals
nevus comedonicus syndrome is a cutaneous condition characterized by a nevus comedonicus associated with cataracts scoliosis and neurologic abnormalities
nevus depigmentosus or nevus achromicus is a depigmentation problem in skin which can be easily differentiated from vitiligo although age factor has not much involvement in the nevus depigmentosus but in about 19 of the cases these are noted at birth their size may however grow in proportion to growth of the body the distribution is also fairly stable and are nonprogressive hypopigmented patches the exact cause of nevus depigmentosus is still not clearly understood a sporadic defect in the embryonic development has been suggested to be a causative factor it has been described as localised albinism though this is incorrect those with nevus depigmentosus may be prone to sunburn due to the lack of pigment and the patient should use good sun protection sunscreen should be applied to all exposed skin since reduced tanning of normal skin will decrease the contrast with hypopigmented skin most patients with nevus depigmentosus do not pursue treatment for their lesion there is no way to repigment the skin if however the lesion is of cosmetic concern camouflage makeup is effective if the lesion is small one could also consider excision
naevus flammeus nuchae often called stork bite or nevus simplex is a congenital capillary malformation present in newborns it is a common type of birthmark in a newborn and is usually temporary
nevus of ito also known as nevus fuscoceruleus acromiodeltoideus is a cutaneous condition with similar features to the nevus of ota but occurring in a different distribution
nevus of ota also known as congenital melanosis bulbi nevus fuscoceruleus ophthalmomaxillaris oculodermal melanocytosis and oculomucodermal melanocytosis is a blue hyperpigmentation that occurs on the face it was first reported by dr m t ota of japan in 1939 nevus of ota is caused by the entrapment of melanocytes in the upper third of the dermis it is found on the face unilaterally and involves the first two branches of the trigeminal nerve the sclera is involved in two thirds of cases causing an increased risk of glaucoma it should not be confused with mongolian spot which is a birthmark caused by entrapment of melanocytes in the dermis but is located in the lumbosacral region women are nearly five times more likely to be affected than men and it is rare among caucasian people nevus of ota may not be congenital and may appear during puberty
nevus psiloliparus is a cutaneous condition a rare scalp anomaly characterized by a variable degree of alopecia and an excessive amount of adipose tissue it is the main hallmark of encephalocraniocutaneous lipomatosis eccl otherwise known as haberland syndrome
nevus sebaceus or sebaceous nevus the first term is its latin name the second term is its name in english also known as an organoid nevus and nevus sebaceus of jadassohn is a congenital hairless plaque that typically occurs on the face or scalp such nevi are present at birth or early childhood affecting males and females of all races equally the condition is named for an overgrowth of sebaceous glands in the area of the nevus skin growths such as benign tumors and basal cell carcinoma can arise in sebaceous nevi usually in adulthood rarely sebaceous nevi can give rise to sebaceous carcinoma however the rate of such malignancies is now known to be less than had been estimated for this reason excision is no longer automatically recommended
nevus spilus also known as speckled lentiginous nevus and zosteriform lentiginous nevus is a skin lesion that presents as a light brown or tan macule speckled with smaller darker macules or papules
nevus unius lateris is a cutaneous condition an epidermal nevus in which the skin lesions are distributed on one half of the body
the new england vampire panic was the reaction to an outbreak of tuberculosis in the 19 th century throughout rhode island eastern connecticut vermont and other parts of new england consumption tuberculosis was thought to be caused by the deceased consuming the life of their surviving relatives bodies were exhumed and internal organs ritually burned to stop the vampire from attacking the local population and to prevent the spread of the disease notable cases provoked national attention and comment such as those of mercy brown in rhode island and frederick ransom in vermont
new public administration is an anti positivist anti technical and anti hierarchical reaction against traditional public administration a practiced theory in response to the ever changing needs of the public and how institutions and administrations go about solving them focus is on the role of government and how they can provide these services to citizens in which are a part of public interest by means but not limited to public policy
new south greenland sometimes known as morrell s land was an appearance of land recorded by the american captain benjamin morrell of the schooner wasp in march 1823 during a sealing and exploration voyage in the weddell sea area of antarctica morrell provided precise coordinates and a description of a coastline which he claimed to have sailed along for more than 300 miles 480 km because the weddell sea area was so little visited and hard to navigate due to ice conditions the alleged land was never properly investigated before its existence was emphatically disproved during antarctic expeditions in the early 20 th century at the time of morrell s voyage the geography of the then unnamed weddell sea and its surrounding coasts was almost entirely unknown making the claimed sighting initially plausible however obvious errors in morrell s voyage account and his general reputation as a fabulist created scepticism about the existence of this new land in june 1912 the german explorer wilhelm filchner searched for but found no traces of land after his ship deutschland became icebound in the weddell sea and drifted into the locality of morrell s observation a sounding of the sea bottom revealed more than 5 000 feet 1 500 m of water indicating no land in near proximity three years later trapped in the same waters with his ship endurance ernest shackleton was able by similar means to confirm the land s non existence various explanations for morrell s error have been suggested including intentional deception however morrell describes his find briefly and prosaically evidently seeking no personal credit or glory from the discovery in his narrative he assigns the honour to his fellow sealing captain robert johnson for finding and naming the land two years earlier morrell may have been honestly mistaken through miscalculation of his ship s position or by misremembering detail when writing the account after nine years alternatively he may have made the common error of confusing distant icebergs with land or been misled by the distorting effects of antarctic mirage in 1843 the distinguished british naval explorer james clark ross reported possible land in a position close to morrell s this land too would eventually be proven not to exist
the new south wales state emergency service nsw ses an agency of the government of new south wales is an emergency and rescue service dedicated to assisting the community in times of natural and man made disasters the nsw ses is made up almost entirely of volunteer members numbering approximately 9 000 as of october 2015 via 228 suburban regional and rural units located throughout new south wales the volunteers are easily identified by their distinctive orange overalls with its history going back to 1955 a state emergency services organisation was established after the hunter valley floods of 1955 when they merged with civil defence in response to fears of a nuclear attack and then restructured in 1972 and again in 1989 following the enactment of the state emergency service act 1989 nsw the agency is led by its commissioner who reports to the minister for emergency services presently the honourable david elliott mp
new daily persistent headache ndph is a primary headache syndrome which can mimic chronic migraine and chronic tension type headache the headache is daily and unremitting from very soon after onset within 3 days at most usually in a person who does not have a history of a primary headache disorder the pain can be intermittent but lasts more than 3 months headache onset is abrupt and people often remember the date circumstance and occasionally the time of headache onset one retrospective study stated that over 80 of patients could state the exact date their headache began the cause of ndph is unknown and it may have more than one etiology ndph onset is commonly associated with an infection or flu like illness stressful life event minor head trauma and extra cranial surgery infection or flu like illness and stressful life event are most often cited the pathophysiology of ndph is poorly understood the syndrome is difficult to treat and may persist for years the age of onset ranges from 6 to greater than 70 years old with a mean of 35 years it is found to be more common in females in both the adult and pediatric populations ndph is rare the akershus study of chronic headache a population based cross sectional study of 30 000 persons aged 30 – 44 years in norway found a one year prevalence of 0 03 percent in the population in 1986 vanast was the first author to describe the new daily persistent headache ndph as a benign form of chronic daily headache cdh the criteria for the diagnosis of ndph were proposed in 1994 the silberstein – lipton criteria but not included in the international classification of headache disorders ichd until 2004
new neo diaspora is a revival or a build upon the standard meaning of diaspora in the sense that it is focused on the cultural economic political and social causes driving it as well as analyzing the multilocality and self consciousness developed by the social group this concept also analyzes the ties within diaspora communities to their native lands which are expressed through strong political and cultural participation in their ancestral lands other significant qualities of new neo diasporas are the thoughts of return to their native land relationships with other communities in the diaspora and lack of full assimilation to the host country
the reconstruction conjecture of stanislaw ulam is one of the best known open problems in graph theory using the terminology of frank harary it can be stated as follows if g and h are two graphs on at least three vertices and ƒ is a bijection from v g to v h such that g v and h ƒ v are isomorphic for all vertices v in v g then g and h are isomorphic in 1964 harary extended the reconstruction conjecture to directed graphs on at least five vertices as the so called digraph reconstruction conjecture many results supporting the digraph reconstruction conjecture appeared between 1964 and 1976 however this conjecture was proved to be false when p k stockmeyer discovered several infinite families of counterexample pairs of digraphs including tournaments of arbitrarily large order the falsity of the digraph reconstruction conjecture caused doubt about the reconstruction conjecture itself stockmeyer even observed that “ perhaps the considerable effort being spent in attempts to prove the reconstruction conjecture should be balanced by more serious attempts to construct counterexamples ” in 1979 ramachandran revived the digraph reconstruction conjecture in a slightly weaker form called the new digraph reconstruction conjecture in a digraph the number of arcs incident from respectively to a vertex v is called the outdegree indegree of v and is denoted by od v respectively id v the new digraph conjecture may be stated as follows if d and e are any two digraphs and ƒ is a bijection from v d to v e such that d v and e ƒ v are isomorphic and od v id v od ƒ v id ƒ v for all v in v d then d and e are isomorphic the new digraph reconstruction conjecture reduces to the reconstruction conjecture in the undirected case because if all the vertex deleted subgraphs of two graphs are isomorphic then the corresponding vertices must have the same degree thus the new digraph reconstruction conjecture is stronger than the reconstruction conjecture but weaker than the disproved digraph reconstruction conjecture several families of digraphs have been shown to satisfy the new digraph reconstruction conjecture and these include all the digraphs in the known counterexample pairs to the digraph reconstruction conjecture as of 2014 no counterexample to the new digraph reconstruction conjecture is known
a new trial or retrial is a recurrence of a court case depending on the rules of the jurisdiction a new trial may occur if a jury is unable to reach a verdict see hung jury a trial court grants a party s motion for a new trial usually on the grounds of a legal defect in the original trial or an appellate court reverses a judgment under circumstances requiring that the case be tried again in some types of cases for example if the original trial court was not a court of record or in some legal systems if the losing party to a case appeals then the appellate court itself will hold a new trial known as a trial de novo in the united states if a defendant is acquitted of a crime the fifth amendment generally prohibits a retrial thus with few exceptions a retrial only can occur if the verdict in the first trial was guilty or if there was no verdict in other legal systems the rules may be different
newcastle disease is a contagious bird disease affecting many domestic and wild avian species it is transmissible to humans it was first identified in java indonesia in 1926 and in 1927 in newcastle upon tyne england whence it got its name however it may have been prevalent as early as 1898 when a disease wiped out all the domestic fowl in northwest scotland its effects are most notable in domestic poultry due to their high susceptibility and the potential for severe impacts of an epizootic on the poultry industries it is endemic to many countries exposure of humans to infected birds for example in poultry processing plants can cause mild conjunctivitis and influenza like symptoms but the newcastle disease virus ndv otherwise poses no hazard to human health interest in the use of ndv as an anticancer agent has arisen from the ability of ndv to selectively kill human tumour cells with limited toxicity to normal cells no treatment for ndv exists but the use of prophylactic vaccines and sanitary measures reduces the likelihood of outbreaks
the newlyn riots were a major civil disturbance that occurred in newlyn cornwall uk on the three days beginning 18 may 1896 monday to wednesday it arose from the local fishery and the trade in fish
the newman – kwart rearrangement is a type of rearrangement reaction in which the aryl group of an o aryl thiocarbamate aroc s nme 2 migrates from the oxygen atom to the sulfur atom forming an s aryl thiocarbamate arsc o nme 2 the reaction is named after its discoverers melvin spencer newman and harold kwart the newman – kwart rearrangement is one of the most important ways of synthesising thiophenols a phenol 1 is deprotonated with a base such as dabco or nah and reacted with a thiocarbamoyl chloride 2 to form an o aryl thiocarbamate 3 heating 3 to around 250 ° c causes it undergo newman – kwart rearrangement to an s aryl thiocarbamate 4 alkaline hydrolysis or similar cleavage yields a thiophenol 5
the newton – pepys problem is a probability problem concerning the probability of throwing sixes from a certain number of dice in 1693 samuel pepys and isaac newton corresponded over a problem posed by pepys in relation to a wager he planned to make the problem was which of the following three propositions has the greatest chance of success a six fair dice are tossed independently and at least one “ 6 ” appears b twelve fair dice are tossed independently and at least two “ 6 ” s appear c eighteen fair dice are tossed independently and at least three “ 6 ” s appear pepys initially thought that outcome c had the highest probability but newton correctly concluded that outcome a actually has the highest probability
nezelof syndrome also known as thymic dysplasia with normal immunoglobulins is an autosomal recessive congenital immunodeficiency condition due to underdevelopment of the thymus an association with cd 44 has been proposed the defect is a type of purine nucleoside phosphorylase deficiency with inactive phosphorylase this results in an accumulation of deoxy gtp which inhibits ribonucleotide reductase ribonucleotide reductase catalyzes the formation of deoxyribonucleotides from ribonucleotides thus dna replication is inhibited and cells cannot replicate
the nia effect is consumer behavior effect used in branding and states that consumers prefer shortened brand names over long ones and also tend to trim long brand names into short ones themselves
the nicholas reaction is an organic reaction where a dicobalt octacarbonyl stabilized propargylic cation is reacted with a nucleophile oxidative demetallation gives the desired alkylated alkyne the nicholas reaction several reviews have been published
a nick is a discontinuity in a double stranded dna molecule where there is no phosphodiester bond between adjacent nucleotides of one strand typically through damage or enzyme action nicks allow for the much needed release of torsion in the strand during dna replication nicks are also thought to play a role in the dna mismatch repair mechanisms that fix errors on both the leading and lagging daughter strands
nicolaides – baraitser syndrome ncbrs is a rare genetic condition caused by de novo missense mutations in the smarca 2 gene and has only been reported in less than 100 cases worldwide ncbrs is a distinct condition and well recognizable once the symptoms have been identified
nicolau – balus syndrome is a cutaneous condition characterized by syringomas and milia
nicotine dependence is a state of dependence upon nicotine there are different ways of measuring nicotine dependence some nicotine dependence assessments focus on key physical dependence outcomes like the development of tolerance which allows people to smoke heavily other assessments ask about psychosocial outcomes or underlying mechanisms of dependence these different assessments either characterize dependence as a continuous construct or use cut offs to diagnose whether someone is or is not dependent nicotine dependence is especially a concern among some populations such as those with co occurring mental illness there are evidence based nicotine dependence treatments that include both medication and psychosocial interventions that can significantly increase a smoker ’ s chances of quitting successfully
nicotine poisoning describes the symptoms of the toxic effects of nicotine following ingestion inhalation or skin contact nicotine poisoning can potentially be deadly though serious or fatal overdoses are rare historically most cases of nicotine poisoning have been the result of use of nicotine as an insecticide more recent cases of poisoning typically appear to be in the form of green tobacco sickness or due to accidental ingestion of tobacco or tobacco products or consumption of nicotine containing plants the estimated lower limit of a lethal dose of nicotine has been reported as between 500 and 1000 mg children may become ill following ingestion of one cigarette ingestion of more than this may cause a child to become severely ill the nicotine in the e liquid of an electronic cigarette can be hazardous to infants and children through accidental ingestion or skin contact in some cases children have become poisoned by topical medicinal creams which contain nicotine people who harvest or cultivate tobacco may experience green tobacco sickness gts a type of nicotine poisoning caused by skin contact with wet tobacco leaves this occurs most commonly in young inexperienced tobacco harvesters who do not consume tobacco
nicotine withdrawal is a group of symptoms that occur in the first few weeks upon the abrupt discontinuation or decrease in intake of nicotine symptoms include cravings for nicotine anger irritability anxiety depression impatience trouble sleeping restlessness hunger or weight gain and difficulty concentrating a quit smoking program may improve one ’ s chance for success in quitting nicotine nicotine withdrawal is recognized in both the american psychiatric association diagnostic and statistical manual and the who international classification of diseases
nidamanuru is an out growth to vijayawada in krishna district of the indian state of andhra pradesh it forms a part of vijayawada urban agglomeration and is located in vijayawada rural mandal of vijayawada revenue division
niemann – pick disease niːmənˈpɪk nee mən pik is a group of inherited severe metabolic disorders in which sphingomyelin accumulates in lysosomes in cells the lysosomes normally transport material through and out of the cell the prognosis is individual but the severe form is fatal in toddlerhood and in some cases patients with the milder forms may have normal lifespans this disease involves dysfunctional metabolism of sphingolipids which are fats found in cell membranes so it is a kind of sphingolipidosis sphingolipidoses in turn are included in the larger family of lysosomal storage diseases
niemann – pick disease smpd 1 associated refers to two different types of niemann – pick disease which are associated with the smpd 1 gene there are approximately 1 200 cases of npa and npb worldwide with the majority of cases being type b or an intermediate form descriptions of type e and type f have been published but they are not well characterized and are currently classified under type b
niemann – pick type c is a lysosomal storage disease associated with mutations in npc 1 and npc 2 genes niemann – pick type c affects an estimated 1 150 000 people approximately 50 of cases present before 10 years of age but manifestations may first be recognized as late as the sixth decade
the niementowski quinazoline synthesis is the chemical reaction of anthranilic acids with amides to form 4 oxo 3 4 dihydroquinazolines 3 h quinazolin 4 ones the niementowski quinazoline synthesis
the niementowski quinoline synthesis is the chemical reaction of anthranilic acids and ketones or aldehydes to form γ hydroxyquinoline derivatives the niementowski quinoline synthesis
the nierenstein reaction is an organic reaction describing the conversion of an acid chloride into an haloketone with diazomethane it is an insertion reaction in that the methylene group from the diazomethane is inserted into the carbon chlorine bond of the acid chloride the nierenstein reaction
the night tube is a service pattern on the london underground system which provides nighttime services to travellers on friday and saturday nights it commenced on the central and victoria lines on 19 august 2016 the jubilee line on 7 october 2016 and is planned to commence on the northern line on 18 november 2016 with the piccadilly line to follow later in the year it was due to start in september 2015 but was delayed due to strike action
night eating syndrome nes is an eating disorder characterized by a delayed circadian pattern of food intake although there is some degree of comorbidity with binge eating disorder it differs from binge eating in that the amount of food consumed in the evening night is not necessarily objectively large nor is a loss of control over food intake required it was originally described by dr albert stunkard in 1955 and is currently included in the other specified feeding or eating disorder category of the dsm 5 research diagnostic criteria have been proposed and include evening hyperphagia consumption of 25 or more of the total daily calories after the evening meal and or nocturnal awakening and ingestion of food two or more times per week the person must have awareness of the night eating to differentiate it from the parasomnia sleep related eating disorder sred three of five associated symptoms must also be present lack of appetite in the morning urges to eat in the evening at night belief that one must eat in order to fall back to sleep at night depressed mood and or difficulty sleeping nes affects both men and women between 1 and 2 of the general population and approximately 10 of obese individuals the age of onset is typically in early adulthood spanning from late teenage years to late twenties and is often long lasting with children rarely reporting nes people with nes have been shown to have higher scores for depression and low self esteem and it has been demonstrated that nocturnal levels of the hormones melatonin and leptin are decreased the relationship between nes and the parasomnia sred is in need of further clarification there is debate as to whether these should be viewed as separate diseases or part of a continuum consuming foods containing serotonin has been suggested to aid in the treatment of nes but other research indicates that diet by itself cannot appreciably raise serotonin levels in the brain a few foods for example bananas contain serotonin but they do not affect brain serotonin levels and various foods contain tryptophan but the extent to which they affect brain serotonin levels must be further explored scientifically before conclusions can be drawn and the idea common in popular culture that a high protein food such as turkey will raise brain tryptophan and serotonin is unfortunately false
night terror also known as sleep terror is a sleep disorder causing feelings of terror or dread and typically occurs during the first hours of stage 3 4 non rapid eye movement nrem sleep night terrors tend to happen during periods of arousal from delta sleep also known as slow wave sleep during the first half of a sleep cycle delta sleep occurs most often which indicates that people with more delta sleep activity are more prone to night terrors however they can also occur during daytime naps night terrors have been known since ancient times although it was impossible to differentiate them from nightmares until rapid eye movement was discovered while nightmares bad dreams that cause feelings of horror or fear are relatively common during childhood night terrors occur less frequently according to the american academy of child and adolescent psychiatry the prevalence of sleep terror episodes has been estimated at 1 – 6 among children and at less than 1 of adults night terrors can often be mistaken for confusional arousal sleep terrors begin in children between the ages of 3 and 12 and usually dissipate during adolescence in adults they most commonly occur between the ages of 20 to 30 though the frequency and severity vary between individuals the episodes can occur in intervals of days or weeks but can also occur over consecutive nights or multiple times in one night night terrors are a largely unknown phenomenon this has created a situation in which any type of nocturnal attack or nightmare may be confused with and reported as a night terror
night vision is the ability to see in low light conditions whether by biological or technological means night vision is made possible by a combination of two approaches sufficient spectral range and sufficient intensity range humans have poor night vision compared to many animals in part because the human eye lacks a tapetum lucidum
a nightmare also called a bad dream is an unpleasant dream that can cause a strong emotional response from the mind typically fear but also despair anxiety and great sadness the dream may contain situations of discomfort psychological or physical terror sufferers often awaken in a state of distress and may be unable to return to sleep for a small period nightmares can have physical causes such as sleeping in an uncomfortable or awkward position having a fever or psychological causes such as stress anxiety and as a side effect of various drugs eating before going to sleep which triggers an increase in the body s metabolism and brain activity is a potential stimulus for nightmares recurrent nightmares may require medical help as they can interfere with sleeping patterns and cause insomnia
nightmare disorder also known as dream anxiety disorder is a sleep disorder characterized by frequent nightmares the nightmares which often portray the individual in a situation that jeopardizes their life or personal safety usually occur during the rem stages of sleep though such nightmares occur within many people those with nightmare disorder experience them with a greater frequency the disorder s dsm iv number is 307 47
niigata minamata disease 新潟水俣病 niigata minamata byō is a neurological syndrome caused by severe mercury poisoning identical in symptoms to the original outbreak of minamata disease in kumamoto prefecture the second outbreak in niigata prefecture was confirmed with the same name in 1965 the disease was caused by severe mercury poisoning the source of which was methylmercury released in the wastewater from mercury sulfate catalysed acetaldehyde production at the showa electrical company s chemical plant in kanose village this highly toxic compound was released untreated into the agano river where it bioaccumulated up the food chain contaminating fish which when eaten by local people caused symptoms including ataxia numbness in the hands and feet general muscle weakness narrowing of the field of vision and damage to hearing and speech 690 people from the agano river basin have been certified as patients of niigata minamata disease since the niigata outbreak was the second recorded in japan and occurred in the lower agano river basin it is sometimes called second minamata disease 第二水俣病 dai ni minamata byō or agano river organic mercury poisoning 阿賀野川有機水銀中毒 agano gawa yūki suigin chūdoku it is one of the four big pollution diseases of japan
nijmegen breakage syndrome nbs also known as berlin breakage syndrome ataxia telangiectasia variant 1 at v 1 and seemanova syndrome is a rare autosomal recessive congenital disorder causing chromosomal instability probably as a result of a defect in the double holliday junction dna repair mechanism and or the synthesis dependent strand annealing mechanism for repairing double strand breaks in dna see homologous recombination nbs 1 codes for a protein that has two major functions 1 to stop the cell cycle in the s phase when there are errors in the cell dna 2 to interact with fancd 2 that can activate the brca 1 brca 2 pathway of dna repair this explains why mutations in the nbs 1 gene lead to higher levels of cancer see fanconi anemia cockayne syndrome the name derives from the dutch city nijmegen where the condition was first described most people with nbs have west slavic origins the largest number of them live in poland
the nineteenth dynasty of ancient egypt notated dynasty xix was one of the periods of the egyptian new kingdom founded by vizier ramesses i whom pharaoh horemheb chose as his successor to the throne this dynasty is best known for its military conquests in canaan the warrior kings of the early 18 th dynasty had encountered only little resistance from neighbouring kingdoms allowing them to expand their realm of influence easily the situation had changed radically towards the end of the 18 th dynasty the hittites gradually extended their influence into syria and canaan to become a major power in international politics a power that both seti i and his son ramesses ii would need to deal with
nintendo thumb also known as gamer s grip nintendinitis and similar names is a video game related health problem classified as a form of repetitive strain injury rsi the symptoms are the blistering paraesthesia and swelling of the thumbs mainly through use of the d pad though any finger can be affected this can lead to stress on tendons nerves and ligaments in the hands and further onto lateral epicondylitis tennis elbow tendinitis bursitis and carpal tunnel syndrome cts some of the symptoms are described under trigger finger originally known in a video gaming context as leather thumb this condition was known to occur frequently among users of 2 nd generation video game consoles such as the intellivision or the atari 2600 in the late 1970 s and early 1980 s the condition was first highlighted when the nintendo games consoles were released leading to reported cases of rsi primarily in children being one of the primary audiences of early generation videogames later the controllers for the sony playstation and playstation 2 were noted as causing the condition however due to the shape size and extended use of game controllers it is not limited to just those specific ones and can occur in users of any gamepad or joystick similar problems have also been observed with the use of mobile phones and text messaging in particular see blackberry thumb
a nipple adenoma is a rare benign tumour of the breast the condition may also be known as florid papillomatosis of the nipple florid adenomatosis subareolar duct papillomatosis erosive adenomatosis
nipple discharge is the release of fluid from the nipples of the breasts although it is considered normal in a wide variety of circumstances it is the third major reason involving the breasts for which women seek medical attention after breast lumps and breast pain it is also known to occur in adolescent boys and girls going through puberty
in sharia islamic law niṣāb نِصاب is the minimum amount for a muslim net worth to be obligated to give zakat several hadith have formulas for calculating niṣāb the most prominent of which declares that no zakāt is due on wealth until one year passes zakat is determined based on the amount of wealth acquired the greater one s assets the greater the tax unlike income tax in secular states niṣāb is not subject to special exemptions in islam niṣāb is 20 dinārs for gold and 200 dirḥams for silver the dinār is a gold coin weighing one mithqal 4 25 grams and the dirḥam is a silver coin weighing 0 7 mithqal 2 975 grams the niṣāb is applicable to the cumulative stock of dinārs dirḥam and any other zakatable valuables such as merchandise that has been in store for at least one year as long as the total value of the zakatable valuables exceeds the value of the niṣāb zakat must be paid
the henry reaction also referred to as the nitro aldol reaction is a classic carbon – carbon bond formation reaction in organic chemistry discovered in 1895 by the belgian chemist louis henry 1834 1913 it is the combination of a nitroalkane and an aldehyde or ketone in the presence of a base to form β nitro alcohols this type of reaction is commonly referred to as a nitro aldol reaction nitroalkane aldehyde and alcohol it is nearly analogous to the aldol reaction that had been discovered 23 years prior that couples two carbonyl compounds to form β hydroxy carbonyl compounds known as aldols aldehyde and alcohol the henry reaction is a useful technique in the area of organic chemistry due to the synthetic utility of its corresponding products as they can be easily converted to other useful synthetic intermediates these conversions include subsequent dehydration to yield nitroalkenes oxidation of the secondary alcohol to yield α nitro ketones or reduction of the nitro group to yield β amino alcohols henry reaction synthetic scheme many of these uses have been exemplified in the syntheses of various pharmaceuticals including the β blocker s propranolol the hiv protease inhibitor amprenavir vertex 478 and construction of the carbohydrate subunit of the anthracycline class of antibiotics l acosamine the synthetic scheme of the l acosamine synthesis can be found in the examples section of this article
narcosis while diving also known as nitrogen narcosis inert gas narcosis raptures of the deep martini effect is a reversible alteration in consciousness that occurs while diving at depth it is caused by the anesthetic effect of certain gases at high pressure the greek word ναρκωσις narcosis is derived from narke temporary decline or loss of senses and movement numbness a term used by homer and hippocrates narcosis produces a state similar to drunkenness alcohol intoxication or nitrous oxide inhalation it can occur during shallow dives but does not usually become noticeable at depths less than 30 meters 100 ft except for helium and probably neon all gases that can be breathed have a narcotic effect although widely varying in degree the effect is consistently greater for gases with a higher lipid solubility and there is good evidence that the two properties are mechanistically related as depth increases the mental impairment may become hazardous divers can learn to cope with some of the effects of narcosis but it is impossible to develop a tolerance narcosis affects all divers although susceptibility varies widely from dive to dive and between individuals narcosis may be completely reversed in a few minutes by ascending to a shallower depth with no long term effects thus narcosis while diving in open water rarely develops into a serious problem as long as the divers are aware of its symptoms and are able to ascend to manage it diving beyond 40 m 130 ft is generally considered outside the scope of recreational diving below these depths as narcosis and oxygen toxicity become critical risk factors specialist training is required in the use of various helium containing gas mixtures such as trimix or heliox these mixtures prevent narcosis by replacing some of the breathing gas with non narcotic helium
the nixon invert was a reputed invert error of the richard nixon memorial postage stamp issued by the united states in 1995 originally reported in january 1996 it drew considerable attention that year but in december a printing plant employee was arrested on charges of having stolen the misprinted stamps from the plant where he worked meaning that instead of a legitimate error they were worthless printer s waste the first public notice of the invert came in the form of an announcement by christie s that they planned to auction a single copy of the invert on february 1 estimating its value at 8 000 10 000 christie s did not supply the name of the consignor a common practice but did say that the stamp was one of 160 the appearance of the stamp was that the portrait of nixon was upside down and shifted so that it was split across the usa 32 inscription was at the bottom and also inverted leaving only the intaglio richard nixon inscription in its correct orientation and position this was possible because the stamp was actually printed in two steps first the portrait and denomination combination was printed by barton press on a heidelberg six color sheet fed offset press then the stamps were sent to the bank note corporation of america s bca plant in suffern new york where the intaglio inscription was applied using a giori press bca also perforated and finished the stamps the claim of 160 stamps and the lack of information on the discovery immediately generated both interest and skepticism to be a valid error the stamps must have been sold to a postal customer until that point they are simply government property by comparison the story of the inverted jenny discovery was known in minute detail and verified by multiple persons in addition it was unclear to philatelic experts how 160 were possible given what they knew about size and handling of sheets of stamps christie s auctioned off the one stamp to an unknown collector for 14 500 thus setting a market price two days previously dealer dana okey of san diego had purchased 141 of the inverts from christie s and by april was selling them for 12 500 characterizing response as awesome on december 12 clarence robert robie a former cutting machine operator at bca s suffern plant was charged with theft of the 160 stamps he was also charged with having transported them to new york and having sold 120 to a brooklyn dealer for 60 000 in june and the remaining 40 in august to a different dealer neither dealer was charged apparently being unaware of the theft it turned out that the nature of the misprint was such that of the original 200 stamp sheets grouped into four 50 stamp panes 10 stamps on the edge of each pane did not receive the intaglio inscription and thus appeared as printing shifts rather than as inverts
njolstad syndrome is a cutaneous condition that combines lymphedema of the limbs and face with congenital pulmonary lymphangiectasias
a no call no show is an absence from the workforce without notifying the employer this form of absence is generally deemed inconsiderate and unprofessional
no reflow phenomenon is the failure of blood to reperfuse an ischemic area after the physical obstruction has been removed or bypassed it may be associated with microvascular damage
nocardiosis is an infectious disease affecting either the lungs pulmonary nocardiosis or the whole body systemic nocardiosis it is due to infection by bacterium of the genus nocardia most commonly nocardia asteroides or nocardia brasiliensis it is most common in men especially those with a weakened immune system in patients with brain infection mortality exceeds 80 in other forms mortality is 50 even with appropriate therapy it is one of several conditions that have been called the great imitator cutaneous nocardiosis commonly occurs in immunocompetent hosts
nocturnal enuresis also called bedwetting is involuntary urination while asleep after the age at which bladder control usually occurs nocturnal enuresis is considered primary pne when a child has not yet had a prolonged period of being dry secondary nocturnal enuresis sne is when a child or adult begins wetting again after having stayed dry most bedwetting is a developmental delay — not an emotional problem or physical illness only a small percentage 5 to 10 of bedwetting cases are caused by specific medical situations bedwetting is frequently associated with a family history of the condition treatments range from behavioral based options such as bedwetting alarms to medication such as hormone replacement and even surgery such as urethral enlargement since most bedwetting is simply a developmental delay most treatment plans aim to protect or improve self esteem bedwetting children and adults can suffer emotional stress or psychological injury if they feel shamed by the condition treatment guidelines recommend that the physician counsel the parents warning about psychological damage caused by pressure shaming or punishment for a condition children cannot control bedwetting is the most common childhood complaint most girls stay dry by age six and most boys stay dry by age seven by ten years old 95 of children are dry at night studies place adult bedwetting rates at between 0 5 and 2 3
nocturnal epilepsy is a seizure disorder in which seizures occur only while sleeping several common forms of epilepsy including frontal lobe epilepsy can manifest in a nocturnal state epilepsy can be nocturnal if the form of epilepsy triggers seizures only while one is asleep or if one normally has seizures that occur at that time in the latter example if the subject stays awake at a time when he is normally sleeping the subject may have the seizure while awake noting this it is important for the subject to maintain a proper sleeping cycle diverting from proper sleep patterns can trigger more frequent epileptic symptoms in people who are diagnosed with nocturnal epilepsy and as mentioned before even while awake
nocturnal sleep related eating disorder nsred also known as sleep related eating disorder sred sleep eating or somnambulistic eating is a combination of a parasomnia and an eating disorder it is described as being in a specific category within somnambulism or a state of sleepwalking that includes behaviors connected to a person ’ s conscious wishes or wants thus many times nsred is a person ’ s fulfilling of their conscious wants that they suppress however this disorder is difficult to distinguish from other similar types of disorders nsred is closely related to night eating syndrome nes except for the fact that those suffering from nes are completely awake and aware of their eating and bingeing at night while those suffering from nsred are sleeping and unaware of what they are doing nes is primarily considered an eating disorder while nsred is primarily considered a parasomnia however both are a combination of parasomnia and eating disorders since those suffering from nes usually have insomnia or difficulty sleeping and those suffering from nsred experience symptoms similar to binge eating some even argue over whether nes and nsred are the same or distinct disorders even though there have been debates over these two disorders specialists have examined them to try to determine the differences dr j winkelman noted several features of the two disorders that were similar but he gave one important factor that make these disorders different in his article sleep related eating disorder and night eating syndrome sleep disorders eating disorders or both dr winkelman said “ both disorders involve nearly nightly binging at multiple nocturnal awakenings defined as excess calorie intake or loss of control over consumption ” he also reported that both disorders have a common occurrence of approximately one to five percent of adults have been predominantly found in women with a young adult onset have a chronic course have a primary morbidity of weight gain sleep disruption and shame over loss of control over food intake have familial bases and have been observed to have comorbid depression and daytime eating disorders however winkelman said “ the most prominent cited distinction between nes and sred is the level of consciousness during nighttime eating episodes ” therefore these two disorders are extremely similar with only one distinction between them this information provided by dr winkelman shows how doctors and psychologists have difficulty differentiating between nes and nsred but the distinction of a person ’ s level of consciousness is what doctors chiefly rely on to make a diagnosis one mistake that is often made is the misdiagnosis of nsred for nes however even though nsred is not a commonly known and diagnosed disease many people suffer from it in differing ways while doctors work to find a treatment that works for everyone several studies have been done on nsred such as the one conducted by schenk and mahowald these studies in turn provide the basic information on this disorder including the symptoms behaviors and possible treatments that doctors are using today
nodal marginal zone b cell lymphoma nmzl is a form of marginal zone lymphoma that can produce colonization of the follicles in the lymph node
nodding disease or nodding syndrome is a recent little known disease which emerged in sudan in the 1960 s it is a mentally and physically disabling disease that only affects children typically between the ages of 5 and 15 it is currently restricted to small regions in south sudan tanzania and northern uganda prior to the south sudan outbreaks and subsequent limited spread the disease was first described in 1962 existing in secluded mountainous regions of tanzania although the connection between that disease and nodding syndrome was only made recently
nodular fasciitis also known as nodular pseudosarcomatous fasciits pseudosarcomatous fasciitis and subcutaneous pseudosarcomatous fibromatosis is a benign soft tissue lesion most commonly found in the superficial fascia the lesion commonly occurs in the first three decades of life upper extremities and trunk are the most common affected anatomical sites previous history of trauma may be present clinically and histologically nodular fasciitis may be mistaken for a sarcoma
nodular lichen myxedematosus is a cutaneous condition characterized by multiple nodules on the limbs and trunk with a mild or absent papular component
nodular lymphocyte predominant hodgkin s lymphoma nlphl is a form of lymphoma some people no longer classified it as a form of classic hodgkin s lymphoma hl this is because the reed sternberg cell rsc variants popcorn cells that characterize this form of the disease invariably express b lymphocyte markers such as cd 20 thus making nlphl an unusual form of b cell lymphoma and that unlike classic hl nlphl may progress to diffuse large b cell lymphoma there are small but clear differences in prognosis between the various forms lymphocyte predominant hl is an uncommon subtype composed of vague nodules of numerous reactive lymphocytes admixed with large popcorn shaped rsc unlike classic rsc the non classic popcorn shaped rs cells of nlphl are cd 15 and cd 30 negative while positive for the b cell marker cd 20 the anti cd 20 monoclonal antibody rituximab has been used in lymphocyte predominant hodgkin s lymphoma with encouraging results bcl 6 gene rearrangements have been frequently observed
nodular melanoma nm is the most aggressive form of melanoma it tends to grow more rapidly in thickness penetrate the skin than in diameter instead of arising from a pre existing mole it may appear in a spot where a lesion did not previously exist since nm tends to grow in depth more quickly than it does in width and can occur in a place that did not have a previous lesion the prognosis is often worse because it takes longer for a person to be aware of the changes nm is most often darkly pigmented however some nm lesions can be light brown multicolored or even colorless non pigmented a light colored or non pigmented nm lesion may escape detection because the appearance is not alarming however an ulcerated and or bleeding lesion is common polypoid melanoma is a virulent variant of nodular melanoma the microscopic hallmarks are dome shaped at low power epidermis thin or normal dermal nodule of melanocytes with a pushing growth pattern no radial growth phase
nodular regenerative hyperplasia is a form of liver hyperplasia associated with portal hypertension nodular regenerative hyperplasia nrh is a rare liver condition characterized by a widespread benign transformation of the hepatic parenchyma into small regenerative nodules nrh may lead to the development of non cirrhotic portal hypertension there are no published systematic population studies on nrh and our current knowledge is limited to case reports and case series nrh may develop via autoimmune hematological infectious neoplastic or drug related causes the disease is usually asymptomatic slowly or non progressive unless complications of portal hypertension develop accurate diagnosis is made by histopathology which demonstrates diffuse micronodular transformation without fibrous septa lack of perinuclear collagen tissue distinguishes nrh from typical regenerative nodules in the cirrhotic liver while the initial treatment is to address the underlying disease ultimately the therapy is directed to the management of portal hypertension the prognosis of nrh depends on both the severity of the underlying illness and the prevention of secondary complications of portal hypertension in this review we detail the epidemiology pathogenesis diagnosis management and prognosis of nrh it can be a complication of azathioprine therapy
nodular sclerosis or nshl is a form of hodgkin s lymphoma that is the most common subtype of hl in developed countries it affects females slightly more than males and has a median age of onset at 28 years it is composed of large tumor nodules with lacunar reed – sternberg cell rs cells surrounded by fibrotic collagen bands the british national lymphoma investigation further categorized nshl based upon reed sternberg cells into nodular sclerosis type i ns i and nodular sclerosis type ii ns ii with the first subtype responding better to treatment
nodular vasculitis is a skin condition characterized by crops of small tender erythematous nodules on the legs mostly on the calves and shins miroscopically there are epithelioid granulomas and vasculitis in the subcutaneous tissue making it a form of panicullitis most of these cases are now thought to be manifestation of tuberculosis and indeed they respond well to anti tuberculous treatment
in medicine nodules are solid elevated areas of tissue or fluid inside or under the skin with a diameter greater than 0 5 centimeters nodules may form on tendons and muscles in response to injury the vocal cords may also develop nodules nodules are normally benign and often painless although they can affect the functioning of the organ vocal fold nodules thyroid nodules and rheumatoid nodules are examples furuncles and kaposi s sarcomae are known to cause dermatological nodules the sexual transmitted disease std gonorrhea is also known for its cause of nodules on the genitalia and mouth for those who are victim to the disease smaller less than 0 5 cm elevated soft tissue lesions may be termed papules
nodules – eosinophilia – rheumatism – dermatitis – swelling syndrome also known as nerds syndrome is a condition with similar clinical features to hypereosinophilic syndrome
nodulosis – arthropathy – osteolysis syndrome is a cutaneous condition that shares features with juvenile hyaline fibromatosis
noise induced hearing loss nihl is hearing impairment resulting from exposure to loud sound people may have a loss of perception of a narrow range of frequencies impaired cognitive perception of sound or other impairment including sensitivity to sound or ringing in the ears hearing may deteriorate gradually from chronic and repeated noise exposure such as loud music or background noise or suddenly from a short high intensity noise such as a gunshot or airhorn in both types loud sound overstimulates delicate hearing cells leading to the permanent injury or death of the cells once lost hearing cannot be restored in humans when exposure to hazards such as noise occur at work and is associated with hearing loss it is referred to as occupational hearing loss there are a variety of prevention strategies available to avoid or reduce hearing loss if not prevented hearing loss can be managed through assistive devices and cognitive therapies prevention is the best defense against noise induced hearing loss the best first option for protecting hearing is lowering the volume of sound at its source secondly limiting the time of exposure to loud noise can reduce injury finally physical protection from the noise can reduce its impact government regulations are designed to limit occupational exposure to dangerously loud noise the largest burden of nihl has been through occupational exposures however noise induced hearing loss can also be due to unsafe recreational residential social and military service related noise exposures it is estimated that 15 of young people are exposed to sufficient leisure noises i e concerts sporting events daily activities personal listening devices etc to cause nihl there is not a limited list of noise sources that can cause hearing loss rather it is important to understand that exposure to excessively high decibel levels from any sound source over time can cause hearing loss
in electrical engineering noise margin is the amount by which a signal exceeds the minimum amount for proper operation it is commonly used in at least two contexts in communications system engineering noise margin is the ratio by which the signal exceeds the minimum acceptable amount it is normally measured in decibels in a digital circuit the noise margin is the amount by which the signal exceeds the threshold for a proper 0 or 1 for example a digital circuit might be designed to swing between 0 0 and 1 2 volts with anything below 0 2 volts considered a 0 and anything above 1 0 volts considered a 1 then the noise margin for a 0 would be the amount that a signal is below 0 2 volts and the noise margin for a 1 would be the amount by which a signal exceeds 1 0 volt in this case noise margins are measured as an absolute voltage not a ratio noise margins for cmos chips are usually much greater than those for ttl because the voh min is closer to the power supply voltage and vol max is closer to zero in simple words noise margin in circuits is the amount of noise that a circuit can withstand noise margins are generally defined so that positive values ensure proper operation and negative margins result in compromised operation or perhaps outright failure
noma also referred to as cancrum oris fusospirochetal gangrene necrotizing ulcerative stomatitis stomatitis gangrenosa is a rapidly progressive polymicrobial often gangrenous infection of the mouth or genitals
noma neonatorum is a cutaneous condition a manifestation of infection usually pseudomonas aeruginosa septicemia and has been reported almost exclusively in developing countries
a nomikai japanese 飲み会 is a drinking party phenomenon particular to japanese culture nomikai are a part of the culture of most places of employment from schools to nightclubs they are most often held in restaurants or izakaya usually with everyone seated at one large table or occupying a separated section of the venue employees are usually expected to participate to some extent in various nomikai as it is considered a social aspect of work although it is not expressly required such parties focus on the bond between coworkers as a group and are not considered private or somehow non work related see japanese values attendance does not necessarily imply that a person will drink any alcohol however and attendees generally pay a set amount for the food drink and venue regardless of consumption any leftover money may be put toward organizing the next nomikai the student version of the nomikai is called a konpa and contains some distinguishing characteristics
the coupon rate or nominal rate or nominal yield of a fixed income security is the annualized amount of the coupon which is a fixed percentage of the par value unlike current yield it does not vary with the market price of the security the coupon rate is typically stated in the name of the bond such as us treasury bond 6 25
non 24 hour sleep – wake disorder non 24 is one of several chronic circadian rhythm sleep disorders crsds it is defined as a chronic steady pattern comprising daily delays in sleep onset and wake times in an individual living in society symptoms result when the non entrained free running endogenous circadian rhythm drifts out of alignment with the light dark cycle in nature the sleep pattern can be quite variable people with a circadian rhythm that is quite near to 24 hours may be able to sleep on a conventional socially acceptable schedule that is at night others with a daily cycle upwards of 25 hours or more may need to adopt a sleep pattern that is congruent with their free running circadian clock shifting their sleep times daily thereby often obtaining satisfactory sleep but suffering social and occupational consequences the majority of people with non 24 are totally blind and the failure of entrainment is explained by an absence of photic input to the circadian clock these people s brains may have normal body clocks but the clocks do not receive input from the eyes about environmental light levels as that requires a functioning retina optic nerve and visual processing center the disorder also occurs in sighted people for reasons that are not well understood their circadian rhythms are not normal often running to more than 25 hours their visual systems may function normally but their brains are incapable of making the large adjustment to a 24 hour schedule though often referred to as non 24 for example by the fda the disorder is also known by the following terms non 24 hour sleep – wake syndrome non 24 hour sleep – wake disorder non 24 hour sleep wake rhythm disorder free running disorder frd hypernychthemeral disorder circadian rhythm sleep disorder – free running type circadian rhythm sleep disorder – nonentrained type n 24 hswd non 24 hour circadian rhythm disorder the disorder in its extreme form is an invisible disability that can be extremely debilitating in that it is incompatible with most social and professional obligations
non hodgkin lymphoma nhl is a group of blood cancers that includes all types of lymphoma except hodgkin s lymphomas symptoms include enlarged lymph nodes fever night sweats weight loss and feeling tired other symptoms may include bone pain chest pain or itchiness some forms are slow growing while others are fast growing lymphomas are types of cancer that develops from lymphocytes a type of white blood cell risk factors include poor immune function autoimmune diseases helicobacter pylori infection hepatitis c obesity and epstein barr virus infection the world health organization who classifies lymphomas into five major groups including one for hodgkin s lymphoma within the four groups for nhl there are over 60 specific types of lymphoma diagnosis is by examination of a bone marrow or lymph node biopsy medical imaging is done to help with cancer staging treatment depends on if the lymphoma is slow or fast growing and if it is in one area or many areas treatments may include chemotherapy radiation immunotherapy targeted therapy stem cell transplantation surgery or watchful waiting if the blood becomes overly thick due to antibodies plasmapheresis may be used radiation and some chemotherapy however increase the risk of other cancers heart disease or nerve problems over the subsequent decades in 2013 about 2 96 million people had non hodgkin lymphoma and 226 000 died in the united states 2 1 of people are affected at some point in their life the most common age of diagnosis is between 65 to 75 years old the percentage of people who survive five years in the united states is 71
non langerhans cell histiocytosis refers to a family of histiocytosis characterized by the absence of langerhans cells many manifest cutaneously the spectrum of non langerhans cell histiocytoses include benign cephalic histiocytosis generalized eruptive histiocytoma indeterminate cell histiocytosis juvenile xanthogranuloma progressive nodular histiocytoma necrobiotic xanthogranuloma giant cell reticulohistiocytoma multicentric reticulohistiocytosis rosai – dorfman disease xanthoma disseminatum kikuchi disease erdheim – chester disease
non x histiocytoses are a clinically well defined group of cutaneous syndromes characterized by infiltrates of monocytes macrophages as opposed to x type histiocytoses in which the infiltrates contain langerhans cells conditions included in this group are juvenile xanthogranuloma benign cephalic histiocytosis generalized eruptive histiocytoma xanthoma disseminatum progressive nodular histiocytosis papular xanthoma hereditary progressive mucinous histiocytosis reticulohistiocytosis indeterminate cell histiocytosis sea blue histiocytosis erdheim chester disease
non alcoholic fatty liver disease nafld is one of the causes of fatty liver occurring when fat is deposited steatosis in the liver due to causes other than excessive alcohol use nafld is the most common liver disorder in developed countries nafld is related to insulin resistance and the metabolic syndrome and may respond to treatments originally developed for other insulin resistant states e g diabetes mellitus type 2 such as weight loss metformin and thiazolidinediones up to 80 of obese people have the disease non alcoholic steatohepatitis nash is the most extreme form of nafld and is regarded as a major cause of cirrhosis of the liver of unknown cause most people have a good outcome if the condition is caught in its early stages a study using the national health and nutrition examination survey nhanes found a 30 rate of nafld in the united states between 2011 and 2012
non celiac gluten sensitivity ncgs or gluten sensitivity is a clinical entity induced by the ingestion of gluten leading to intestinal and or extraintestinal symptoms that resolve once the gluten containing foodstuff is eliminated from the diet and when celiac disease and wheat allergy have been ruled out ncgs is included in the spectrum of gluten related disorders the definition and diagnostic criteria of non celiac gluten sensitivity were debated and established by three consensus conferences the pathogenesis of ncgs is not yet well understood there is evidence that not only gliadin main cytotoxic antigen of gluten but also other proteins present in gluten and gluten containing cereals wheat rye barley and their derivatives may have a role in the development of symptoms fodmaps are present in gluten containing grains and have recently been identified as a possible cause of gastrointestinal symptoms in ncgs patients but do not justify extra digestive symptoms for these reasons ncgs is a controversial syndrome and some authors still question it it has been suggested that non celiac wheat sensitivity is a more appropriate term without forgetting that other gluten containing cereals are implicated in the development of symptoms ncgs is the most common syndrome of gluten related disorders with prevalence rates between 0 5 – 13 in the general population as no biomarker for diagnosing this condition is available its diagnosis is made by exclusion of other gluten related disorders namely by excluding celiac disease and wheat allergy many people have not been diagnosed following strict criteria and there is a fad component to the recent rise in popularity of the gluten free diet which leads to debate surrounding the evidence for this condition its relationship to celiac disease and to irritable bowel syndrome
non cirrhotic portal fibrosis ncpf is a chronic liver disease and type of non cirrhotic portal hypertension ncph it is characterized by obliterative portovenopathy which leads to various problems such as portal hypertension massive splenomegaly and variceal bleeding it is estimated that about 85 of people with ncpf have repeated episodes of variceal bleeding hallmark of the disease is thrombosis sclerosis of portal vein branches vessels formed are often termed as mesangiosinusoids or periportal cavernoma
a non communicable disease ncd is a medical condition or disease that is non infectious or non transmissible ncds can refer to chronic diseases which last for long periods of time and progress slowly sometimes ncds result in rapid deaths such as seen in certain diseases such as autoimmune diseases heart diseases stroke cancers diabetes chronic kidney disease osteoporosis alzheimer s disease cataracts and others while sometimes referred to as synonymous with chronic diseases ncds are distinguished only by their non infectious cause not necessarily by their duration though some chronic diseases of long duration such as hiv aids may caused by infections chronic diseases require chronic care management as do all diseases that are slow to develop and of long duration ncds are the leading cause of death globally in 2012 they cause 68 of all deaths 38 million up from 60 in 2000 about half were under age 70 and half were women risk factors such as a person s background lifestyle and environment increase the likelihood of certain ncds every year at least 5 million people die because of tobacco use and about 2 8 million die from being overweight high cholesterol accounts for roughly 2 6 million deaths and 7 5 million die because of high blood pressure
non food items nfis are items other than food the term is especially used in humanitarian contexts when providing nfis to those affected by natural disasters or war may be a life saving priority typically they include essential household items such as blankets plastic sheets buckets and other containers for water cooking items and soap
nongonococcal urethritis ngu is an inflammation of the urethra that is not caused by gonorrheal infection for treatment purposes doctors usually classify infectious urethritis in two categories gonococcal urethritis caused by gonorrhea and nongonococcal urethritis ngu
increased intracranial pressure icp is one of the major causes of secondary brain ischemia that accompanies a variety of pathological conditions most notably traumatic brain injury tbi stroke and intracranial hemorrhages increased intracranial pressure can cause such complications as viip death permanent neurological problems reversible neurological problems seizures stroke however aside from a few level i trauma centers icp monitoring is rarely a part of the clinical management of patients with these conditions because of the invasiveness of the standard monitoring methods which require insertion of an icp sensor into the brain ventricle or parenchymal tissue additional risks they present for patients high costs associated with an icp sensor s implantation procedure and the limited access to trained personnel i e a neurosurgeon alternative methods have therefore been sought with which icp can be estimated non invasively absolute majority of the approaches to non invasive icp estimation are based on the idea that something in the human head s anatomical structure or in the intracranial and extracranial physiology correlates with icp very important limitation of such correlation based approaches is caused by the fact that correlation shows some relationship but did not show the slope and bias of such relationship correlation based approaches can reflect icp changes only with limited accuracy expressed by systematic error and precision expressed by standard deviation of random error because of that such approaches are not able to measure quantitatively an absolute icp value because of the need for individual patient specific calibration calibration is an only procedure for identification of slope and bias of correlation based association calibration of non invasive icp meter or monitor is impossible because of impossibility to create a gold standard non invasive icp meter for calibration purposes absolute icp values in mmhg or other units are needed for patients treatment decision making the only accurate precise and patient specific calibration free non invasive absolute icp value measurement method relies not on the correlation but on direct icp and extracranial pressure comparison principle innovative method using two depth transorbital doppler tdtd of intracranial pressure quantitative absolute icp value measurement relies on the same fundamental principle as used to measure blood pressure with a sphygmomanometer a sphygmomanometer works using a pressure balance principle an air filled pressure cuff wrapped around the arm compresses the brachial artery to a point where blood can no longer flow externally applied pressure is equal to systolic blood pressure in this case the examiner slowly releases the air from the cuff and uses a stethoscope to listen for the return of blood flow at the pressure balance point where pressure in the cuff equals systolic artery pressure a ‘ whooshing ’ noise can be heard as blood flows through the artery again pressure balance based non invasive blood pressure meter does not need a patient specific calibration the tdtd method uses doppler ultrasound to translate pressure balance principle of blood pressure measurement with a sphygmomanometer to the measurement of icp ophthalmic artery oa a unique vessel with intracranial and extracranial segments is used as pressure sensor and as a natural pair of scales for absolute icp value in mmhg or mmh 2 o measurement blood flow in the intracranial oa segment is affected by intracranial pressure while flow in the extracranial intraorbital oa segment is influenced by the externally applied pressure pe to the eyeball and orbital tissues as with a sphygmomanometer a special pressure cuff is used in this case to compress the tissues surrounding the eyeball and also intraorbital tissues surrounding the extracranial segment of oa external pressure changes the characteristics of blood flowing from inside the skull cavity into the eye socket in place of the stethoscope a doppler ultrasound beam measures the blood flow pulsations in intracranial and extracranial segments of the ophthalmic artery the non invasive icp meter based on this method gradually increases the pressure over the eyeball and intraorbital tissues so that the blood flow pulsation parameters in two sections of oa are equal at this pressure balance point the applied external pressure pe equals to the intracranial pressure icp this measurement method eliminates the main limiting problem of all other non successful approaches to non invasive icp measurement the individual patient calibration problem direct comparison of arterial blood pressure abp and externally applied pressure is the basic arterial blood pressure measurement principle which eliminates the need of individual calibration the same calibration free fundamental principle is used in tdtd non invasive icp absolute value measurement method the mean value of oa blood flow its systolic and diastolic values pulsatility and other indexes are almost the same in both oa segments in the point of balance when icp pe as a result of that all individual influential factors abp cerebrovascular autoregulation impairment individual pathophysiological state of patient individual diameter and anatomy of oa hydrodynamic resistance of eyeball vessels etc do not influence the balance icp pe and as a consequence such natural “ scales ” do not need calibration ragauskas a et al already published the statistically significant results of prospective clinical study on assessment of the accuracy and precision of proposed non invasive absolute icp value measurement method the study shows that proposed method is the only quantitative noninvasive icp absolute value mmhg measurement method which does not need an individual patient specific calibration high accuracy precision sensitivity and specificity of proposed method are fully acceptable for clinical practice and for very wide applications in neurology transplantology intensive care sport medicine aerospace medicine and combat casualty care this method is further developed by company vittamed ltd together with consortium partners in eu fp 7 projects brainsafe brainsafe brainsafe ii and tbicare
non involuting congenital hemangioma is a cutaneous condition lesions occur slightly more often in male infants and are well developed at birth
non mycosis fungoides cd 30 − cutaneous large t cell lymphoma is a cutaneous condition that usually presents as solitary or generalized plaques nodules or tumors of short duration
non progressive late onset linear hemifacial lipoatrophy is a cutaneous condition that occurs on the malar cheek mostly in the elderly population
non small cell lung carcinoma nsclc is any type of epithelial lung cancer other than small cell lung carcinoma sclc nsclc accounts for about 85 of all lung cancers as a class nsclcs are relatively insensitive to chemotherapy compared to small cell carcinoma when possible they are primarily treated by surgical resection with curative intent although chemotherapy is increasingly being used both pre operatively neoadjuvant chemotherapy and post operatively adjuvant chemotherapy
non islet hypoglycemic cell tumor is a rare tumor that secretes the protein insulin like growth factor 2 into the bloodstream this protein causes cells to consume excessive amounts of sugar which can cause the condition hypoglycemia low blood sugar
non linear piezoelectric effects in polar semiconductors are the manifestation that the strain induced piezoelectric polarization depends not just on the product of the first order piezoelectric coefficients times the strain tensor components but also on the product of the second order or higher piezoelectric coefficients times products of the strain tensor components the idea was put forward for zincblende gaas and inas semiconductors since 2006 and then extended to all commonly used wurtzite and zincblende semiconductors given the difficulty of finding direct experimental evidence for the existence of these effects there are different schools of thought on how one can calculate reliably all the piezoelectric coefficients on the other hand there is widespread agreement on the fact that non linear effects are rather large and comparable to the linear terms first order indirect experimental evidence of the existence of these effects has been reported in the literature in relation to gan and inn semiconductor optoelectronic devices
nonallergic rhinitis is inflammation of the inner part of the nose that is not caused by an allergy nonallergic rhinitis involves symptoms including chronic sneezing or having a congested drippy nose without an identified allergic reaction other common terms for nonallergic rhinitis are vasomotor rhinitis and perennial rhinitis the prevalence of nonallergic rhinitis in otolaryngology is 40 allergic rhinitis is more common than nonallergic rhinitis however both conditions have similar presentation manifestation and treatment nasal itching and paroxysmal sneezing are usually associated with nonallergic rhinitis in comparison to allergic rhinitis
non bacterial thrombotic endocarditis nbte is a form of endocarditis in which small sterile vegetations are deposited on the valve leaflets formerly known as marantic endocarditis which comes from the greek marantikos meaning “ wasting away ” the term marantic endocarditis is still sometimes used to emphasize the association with a wasting state such as cancer
non compaction cardiomyopathy ncc also called spongiform cardiomyopathy is a rare congenital cardiomyopathy that affects both children and adults it results from the failure of myocardial development during embryogenesis during development the majority of the heart muscle is a sponge like meshwork of interwoven myocardial fibers as normal development progresses these trabeculated structures undergo significant compaction that transforms them from spongy to solid this process is particularly apparent in the ventricles and particularly so in the left ventricle noncompaction cardiomyopathy results when there is failure of this process of compaction because the consequence of non compaction is particularly evident in the left ventricle the condition is also called left ventricular noncompaction other hypotheses and models have been proposed none of which is as widely accepted as the noncompaction model symptoms range greatly in severity most are a result of a poor pumping performance by the heart the disease can be associated with other problems with the heart and the body
in computational complexity theory a nonelementary problem is a problem that is not a member of the class elementary examples of nonelementary problems that are nevertheless decidable include the problem of regular expression equivalence with complementation decision problem for monadic second order logic over trees decision problem for term algebras
a nonossifying fibroma also called fibroxanthoma is a fibrous bone lesion that is usually asymptomatic and discovered as an incidental finding on x ray it is the most common benign bone tumor in children and adolescents however it is controversial whether it represents a true neoplasm or rather a developmental disorder of growing bone radiographically the tumor presents as a well marginated radiolucent lesion with a distinct multilocular appearance these foci consist of collagen rich connective tissue fibroblasts histiocytes and osteoclasts they originate from the growth plate and are located in adjacent parts of the metaphysis and diaphysis of long bones most often of the legs no treatment is needed in asymptomatic patients and spontaneous remission with replacement by bone tissue is to be expected multiple nonossifying fibromas occur in jaffe campanacci syndrome in combination with cafe au lait spots mental retardation hypogonadism ocular and cardiovascular abnormalities
in political science nonpartisanism is a lack of affiliation with a political party some organizations claiming to be nonpartisan are truly such others are nominally nonpartisan for reasons of law or public perception but closely follow the policies of a political party while the dictionary definition of partisan includes adherents of a party cause person etc in many cases nonpartisan refers specifically to political party connections rather than being the strict antonym of partisan and an organization described as nonpartisan can have many decidedly controversial policies
nonsyndromic deafness is hearing loss that is not associated with other signs and symptoms in contrast syndromic deafness involves hearing loss that occurs with abnormalities in other parts of the body genetic changes are related to the following types of nonsyndromic deafness dfna nonsyndromic deafness autosomal dominant dfnb nonsyndromic deafness autosomal recessive dfnx nonsyndromic deafness x linked nonsyndromic deafness mitochondrial each type is numbered in the order in which it was described for example dfna 1 was the first described autosomal dominant type of nonsyndromic deafness mitochondrial nonsyndromic deafness involves changes to the small amount of dna found in mitochondria the energy producing centers within cells most forms of nonsyndromic deafness are associated with permanent hearing loss caused by damage to structures in the inner ear the inner ear consists of three parts a snail shaped structure called the cochlea that helps process sound nerves that send information from the cochlea to the brain and structures involved with balance loss of hearing caused by changes in the inner ear is called sensorineural deafness hearing loss that results from changes in the middle ear is called conductive hearing loss the middle ear contains three tiny bones that help transfer sound from the eardrum to the inner ear some forms of nonsyndromic deafness involve changes in both the inner ear and the middle ear this combination is called mixed hearing loss the severity of hearing loss varies and can change over time it can affect one ear unilateral or both ears bilateral degrees of hearing loss range from mild difficulty understanding soft speech to profound inability to hear even very loud noises the loss may be stable or it may progress as a person gets older particular types of nonsyndromic deafness often show distinctive patterns of hearing loss for example the loss may be more pronounced at high middle or low tones nonsyndromic deafness can occur at any age hearing loss that is present before a child learns to speak is classified as prelingual or congenital hearing loss that occurs after the development of speech is classified as postlingual
nonthrombocytopenic purpura is a type of purpura red or purple skin discoloration not associated with thrombocytopenia examples causes include henoch – schönlein purpura hereditary hemorrhagic telangiectasia congenital cytomegalovirus meningococcemia
nontoxic nodular goiter is an enlarged thyroid without hyperthyroidism it is often present for years before toxic nodular goiter occurs in the united states it is the most common cause of a large thyroid affecting between 3 and 5 of the population
bejel or endemic syphilis is a chronic skin and tissue disease caused by infection by the endemicum subspecies of the spirochete treponema pallidum bejel is also known by a variety of other names including belesh dichuchwa endemic syphilis nonvenereal syphilis frenga njovera skerljevo siti or treponematosis bejel type
noonan syndrome ns is a relatively common autosomal dominant congenital disorder and is named after jacqueline noonan a pediatric cardiologist it is referred to as the male version of turner s syndrome and is still sometimes described in this way however the genetic causes of noonan syndrome and turner syndrome are distinct the principal features include congenital heart defect typically pulmonary valve stenosis also atrial septal defect and hypertrophic cardiomyopathy short stature learning problems pectus excavatum impaired blood clotting and a characteristic configuration of facial features including a webbed neck and a flat nose bridge ns is a rasopathy and is one of several disorders that are caused by a disruption of ras mapk pathway signaling it is believed that between approximately 1 in 1 000 and 1 in 2 500 children worldwide are born with ns it is one of the most common genetic syndromes associated with congenital heart disease similar in frequency to down syndrome however the range and severity of features can vary greatly in patients with ns therefore the syndrome is not always identified at an early age
noonan syndrome with multiple lentigines nsml also known as leopard syndrome cardiocutaneous syndrome gorlin syndrome ii lentiginosis profusa syndrome progressive cardiomyopathic lentiginosis capute rimoin konigsmark esterly richardson syndrome or moynahan syndrome which is part of a group called ras mapk pathway syndromes — is a rare autosomal dominant multisystem disease caused by a mutation in the protein tyrosine phosphatase non receptor type 11 gene ptpn 11 the disease is a complex of features mostly involving the skin skeletal and cardiovascular systems which may or may not be present in all patients the nature of how the mutation causes each of the condition s symptoms is not well known however research is ongoing it is a rasopathy noonan syndrome with multiple lentigines is caused by a different missense mutation of the same gene noonan syndrome is fairly common 1 1 000 to 1 2 500 live births and neurofibromatosis 1 which was once thought to be related to nsml is also common 1 3500 however no epidemiological data exists for nsml
the nor west arch is a weather pattern peculiar to the east coast of new zealand s south island for this reason it is also often referred to as the canterbury arch although it is visible in both otago and marlborough as well as in the canterbury region it is shown in an apparent arch of high white cloud in an otherwise clear blue sky over the southern alps and is accompanied by a strong hot northwesterly or northerly wind simply known as the nor wester closer to the canterbury coast some distance from the mountains of the southern alps it appears as a clear area of blue above the mountains with white cloud streaming to the east from it the phenomenon is similar to the chinook arch seen in the pacific regions of the united states and canada
in linear algebra functional analysis and related areas of mathematics a norm is a function that assigns a strictly positive length or size to each vector in a vector space — save for the zero vector which is assigned a length of zero a seminorm on the other hand is allowed to assign zero length to some non zero vectors in addition to the zero vector a norm must also satisfy certain properties pertaining to scalability and additivity which are given in the formal definition below a simple example is the 2 dimensional euclidean space r 2 equipped with the elements in this vector space e g 3 7 are usually drawn as arrows in a 2 dimensional cartesian coordinate system starting at the origin 0 0 the euclidean norm assigns to each vector the length of its arrow because of this the euclidean norm is often known as the magnitude a vector space on which a norm is defined is called a normed vector space similarly a vector space with a seminorm is called a seminormed vector space it is often possible to supply a norm for a given vector space in more than one way
in renal physiology normal anion gap acidosis and less precisely non anion gap acidosis is an acidosis that is not accompanied by an abnormally increased anion gap the most common etiology of normal anion gap acidosis is diarrhea with a renal tubular acidosis being a distant second
normal backwardation also sometimes called backwardation is the market condition wherein the price of a forward or futures contract is trading below the expected spot price at contract maturity the resulting futures or forward curve would typically be downward sloping i e inverted since contracts for further dates would typically trade at even lower prices in practice the expected future spot price is unknown and the term backwardation may be used to refer to positive basis which occurs when the current spot price exceeds the price of the future the opposite market condition to normal backwardation is known as contango similarly in practice the term may be used to refer to negative basis where the current spot price is below the future price a backwardation starts when the difference between the forward price and the spot price is less than the cost of carry or when there can be no delivery arbitrage because the asset is not currently available for purchase futures contract price includes compensation for the risk transferred from the asset holder this makes actual price on expiry to be lower than futures contract price backwardation very seldom arises in money commodities like gold or silver in the early 1980 s there was a one day backwardation in silver while some metal was physically moved from comex to cbot warehouses gold has historically been positive with exception for momentary backwardations hours since gold futures started trading on the winnipeg commodity exchange in 1972 the term is sometimes applied to forward prices other than those of futures contracts when analogous price patterns arise for example if it costs more to lease silver for 30 days than for 60 days it might be said that the silver lease rates are in backwardation negative lease rates for silver may indicate bullion banks require a risk premium for selling silver futures into the market
normal conditions are a restriction on philosophical arguments especially in epistemology in order to avoid objections perceived as digressive as a reply to objections to an explanation of a phenomenon e g a hypothesis or a theory it is said argument x holds only under normal conditions in some cases the concept of normal conditions tends to be rather blurred and the reply under normal conditions can tend to extend to everything that contradicts an argument in cases when the argument of normal conditions comes too often according to the principle of occam s razor another explanation x has to be found
in physics and engineering for a dynamical system according wave theory a mode is a standing wave state of excitation in which all the components of the system will be affected sinusoidally under a specified fixed frequency because no real system can perfectly fit under the standing wave framework the mode concept is taken as a general characterization of specific states of oscillation thus treating the dynamic system in a linear fashion in where linear superposition of states can be performed as classical examples there are in a mechanical dynamical system a vibrating rope is the most clear example of a mode in which the rope is the medium the stress on the rope is the excitation and the displacement of the rope with respect to its static state is the modal variable in an acoustic dynamical systems a single sound pitch is a mode in which the air is the medium the sound pressure in the air is the excitation and the displacement of the air molecules is the modal variable in a structural dynamical systems a high tall building oscillating under its most flexural axis is a mode in which all the material of the building under the proper numerical simplifications is the medium the seismic wind environmental solicitations are the excitations and the displacements are the modal variable in an electrical dynamical systems a resonant cavity made of thin metal walls enclosing a hollow space for a particle accelerator is a pure standing wave system and thus an example of a mode in which the hollow space of the cavity is the medium the rf source a klystron or another rf source is the excitation and the electromagnetic field is the modal variable when relating to music normal modes of vibrating instruments strings air pipes drums etc are called harmonics or overtones the concept of normal modes also finds application in optics quantum mechanics and molecular dynamics most dynamical system can be excited under several modes each mode is characterized by one or several frequencies according the modal variable field for example a vibrating rope in the 2 d space is defined by a single frequency 1 d axial displacement but a vibrating rope in the 3 d space is defined by two frequencies 2 d axial displacement for a given amplitude on the modal variable each mode will store an specific amount of energy because of the sinusoidal excitation from all the modes of a dynamical system the normal or dominant mode of a system will be the mode storing the minimum amount of energy for a given amplitude of the modal variable or equivalently for a given stored amount of energy will be the mode imposing the maximum amplitude of the modal variable
normal pressure hydrocephalus nph also termed symptomatic hydrocephalus is a type of brain malfunction caused by expansion of the lateral cerebral ventricles and distortion of the fibers in the corona radiata its typical symptoms are urinary incontinence dementia and gait disturbance csf pressure is usually normal ventricles are chronically dilated the usual treatment is surgical installation of a ventriculoperitoneal shunt to drain excess csf into the lining of the abdomen where the csf will eventually be absorbed
normal tension glaucoma ntg is an eye disease a neuropathy of the optic nerve that shows all the characteristics of traditional glaucoma except one the elevated intraocular pressure iop the classic hallmark of glaucoma is missing normal tension glaucoma is in many cases closely associated with general issues of blood circulation and of organ perfusion like arterial hypotension metabolic syndrome and flammer syndrome
normal weight obesity is a condition of having normal body weight but high body fat percentages with the same health risks of obesity
lissencephaly 2 more commonly called norman – roberts syndrome is a rare form of lissencephaly caused by a mutation in the reelin gene a small number of cases have been described the syndrome was first reported by m norman and m roberts et al in 1976 lack of reelin prevents normal layering of the cerebral cortex and disrupts cognitive development patients have cerebellar hypoplasia and suffer from congenital lymphedema and hypotonia the disorder is also associated with myopia nystagmus and generalized seizures norman – roberts syndrome is one of two known disorders caused by a disruption of the reelin signaling pathway the other is vldlr associated cerebellar hypoplasia which is caused by a mutation in the gene coding for one of the reelin receptors vldlr disruption of the reln gene in human patients is analogous to the malfunctioning reln gene in the reeler mouse
normolipoproteinemic xanthomatosis is a cutaneous condition characterized by a xanthoma in the presence of normal cholesterol and lipoprotein levels
normophosphatemic familial tumoral calcinosis is a cutaneous disorder characterized by cutaneous calcification or ossification
the norn stones are fictional powerful magical items from asgard featured in the marvel universe
norrie disease is a genetic disorder that primarily affects the eye and almost always leads to blindness in addition to the congenital ocular symptoms some patients suffer from a progressive hearing loss starting mostly in their 2 nd decade of life while another portion may be mentally challenged patients with norrie disease may develop cataracts leukocoria a condition where the pupils appear white when light is shone on them along with other developmental issues in the eye such as shrinking of the globe and the wasting away of the iris around 30 to 50 of them will also have developmental delay mental retardation psychotic like features incoordination of movements or behavioral abnormalities most patients are born with normal hearing however the onset of hearing loss is very common in early adolescence about 15 of patients are estimated to develop all the features of the disease the disease affects almost only male infants at or soon after birth because the disease is inherited x linked recessive only in very rare cases females have been diagnosed with norrie disease as well the exact incidence number is unknown only a few hundred cases have been reported it is a very rare disorder that is not associated with any specific ethnic or racial groups
the north aleutians basin is a geographic phenomenon primarily a submarine depression occurring in the southern bristol bay region of the bering sea and just off the northern shore of the alaska peninsula it extends some 600 miles 960 km along the alaska peninsula northeast southwest and nearly as far north south into the center of the bering sea primarily composed of gravel and sand the near shore zone is famously muddy towards its eastern flank long known for its potential riches the area was heavily prospected by oil and gas prospectors mostly notable shell from the early 1960 s through the present since the area is important for the highly prized sockeye salmon fishery particularly in communities like dillingham naknek and king salmon the entire area was until recently subject to a federal offshore drilling moratorium as recently as october 2005 both the state of alaska and the u s minerals management service had plans to develop the oil and especially natural gas potential of the area one proposal would have offshore platforms extracting natural gas north of the village of nelson lagoon and transporting the gas via pipeline to a processing facility to the pacific ocean side near sand point
north american indian childhood cirrhosis naic is a disease in humans that can affect ojibway cree children in northwestern quebec canada the disease is due to an autosomal recessive abnormality of the cirh 1 a gene which codes for cirhin naic is a ribosomopathy an r 565 w mutation of cirh 1 a leads to partial impairment of cirhin interaction with nol 11 initial transient neonatal jaundice advances over time to biliary cirrhosis with severe liver fibrosis eventually liver failure occurs and requires liver transplantation
north asian tick typhus or north asian tick fever also known as siberian tick typhus is a condition characterized by a maculopapular rash it is associated with rickettsia sibirica
the north atlantic oscillation nao is a weather phenomenon in the north atlantic ocean of fluctuations in the difference of atmospheric pressure at sea level between the icelandic low and the azores high through fluctuations in the strength of the icelandic low and the azores high it controls the strength and direction of westerly winds and storm tracks across the north atlantic it is part of the arctic oscillation and varies over time with no particular periodicity the nao was discovered through several studies in the late 19 th and early 20 th centuries unlike the el niño southern oscillation phenomenon in the pacific ocean the nao is a largely atmospheric mode it is one of the most important manifestations of climate fluctuations in the north atlantic and surrounding humid climates the north atlantic oscillation is closely related to the arctic oscillation ao or northern annular mode nam but should not be confused with the atlantic multidecadal oscillation amo
the north melbourne grand final breakfast is a breakfast function organised by the north melbourne football club on the morning of the afl grand final the breakfast marks the traditional beginning to grand final day and is one of the biggest social highlights on the australian sporting calendar watching the event is a ritual for many footy fans and the function plays a huge role in the pre match build up for the grand final
the north pacific oscillation npo is a teleconnection pattern first described by walker and bliss and characterized by a north south seesaw in sea level pressure over the north pacific rogers using surface atmospheric temperature from st paul alaska and edmonton identified two phases of the npo an aleutian below ab phase that correspond to a deepened and eastward shifted aleutian low and an aleutian above aa phase that is the opposite during the positive ab phase sea level pressure is enhanced over a large region in the subtropics that extend poleward to 40 n ° and reduced at higher latitudes westerlies are enhanced over the central pacific and winter temperature are mild along much of the north america west coast but cooler than usual over eastern siberia and the united states south west precipitations are higher than usual over alaska and the great plains the npgo is the oceanic expression of the npo
the northeast blackout of 1965 was a significant disruption in the supply of electricity on tuesday november 9 1965 affecting parts of ontario in canada and connecticut massachusetts new hampshire new jersey new york rhode island pennsylvania and vermont in the united states over 30 million people and 80 000 square miles 207 000 km 2 were left without electricity for up to 13 hours
northern corn leaf blight nclb is a foliar disease of corn maize caused by exserohilum turcicum the anamorph of the ascomycete setosphaeria turcica with its characteristic cigar shaped lesions this disease can cause significant yield loss in susceptible corn hybrids
northern epilepsy syndrome or progressive epilepsy with mental retardation epmr is a subtype of neuronal ceroid lipofuscinosis and a rare disease that is regarded as a finnish heritage disease unlike most finnish heritage diseases this syndrome has been reported only in finland the disease is characterized by seizures in early childhood that progressively get worse until after puberty once the onset of seizures occurs mental degradation is seen this continues into adulthood even after seizure frequency has decreased the cause of the disease is a missense mutation in chromosome 8 the creation of a new protein occurs and the lipid content of the brain is altered because of it the ratio of the mutation carriers is 1 135 there is nothing that has been found to stop the progression of the disease but symptomatic approaches such as the use of benzodiazepines have helped control seizures
the northern subject rule is a grammatical pattern that occurs in northern english and scots dialects present tense verbs may take the verbal ‑ s suffix except when they are directly adjacent to one of the personal pronouns i you we or they as their subject as a result they sing contrasts with the birds sings they sing and dances it s you that sings i only sings in the modern northern english dialects this pattern varies and now competes with standard forms furthermore other non standard dialectal patterns are found that developed separately from the northern subject rule these include for example the free use of ‑ s in the historic present especially when introducing quoted speech i says the free use of ‑ s as a marker of habitual semantics i goes to work may also occur a widespread tendency to level the contrast between was and were sometimes to i were he were more often to we was you was almost universal levelling of the contrast between there was a raven and there were two ravens some controversy surrounds its origin some scholars e g graham isaac argue that it developed out of the old english verbal endings by way of northern middle english but others e g h tristram argue that it could be a language contact transfer feature from the brythonic language historically spoken in that area graham shorrocks notes that a similar use of the historic present occurs in some dialects of north germany citing gordon 1966 and wakernagel jolles 1971 this is part of the greater debate whether the celtic languages have had any influence on the structure of english due to the celtic population learning the english language rapidly but imperfectly after the coming of the angles some linguists have expressed a very strong opinion in favor of the language contact theory john mcwhorter for instance called the northern subject rule a bizarre trait and claims that similar phenomena are otherwise only known in vso languages like brythonic and rare even in that case newfoundland english and at least some hiberno english dialects the dialect of wexford for example follow a similar pattern
northern vigor is an effect seen in certain varieties of produce where varieties of plants grown in northern climates then moved to southern climates are hardier better producing and better tasting this effect has been primarily observed in potatoes but is also seen in strawberries and garlic the saskatchewan seed potato growers association has trademarked the term northern vigour for use with their potatoes but the effect is seen in produce grown throughout canada and the northern united states the exact cause of northern vigor is not known but there are many theories some believe it has to do with the length of the days in northern latitudes or that it has to do with the combination of cold nights and hot days others believe that the cold may kill off any disease that would otherwise affect plants from the south still others think that the switch from a colder climate to a warm less harsh environment makes it easier for the plants to thrive researchers in saskatchewan discovered that tubers raised in the cold and then moved to a warm environment undergo a series of physiological changes that may trigger more vigorous growth
epistaxis also known as a nosebleed is the common occurrence of bleeding from the nose it is usually noticed when the blood drains out through the nostrils there are two types anterior the most common and posterior less common more likely to require medical attention sometimes in more severe cases the blood can come up the nasolacrimal duct and out from the eye fresh blood and clotted blood can also flow down into the stomach and cause nausea and vomiting although the sight of large amounts of blood can be alarming and may warrant medical attention nosebleeds are rarely fatal accounting for only 4 of the 2 4 million deaths in the u s in 1999 about 60 of people have a nosebleed at some point in their life about 10 of nosebleeds are serious
nosophobia is the irrational fear of contracting a disease a type of specific phobia primary fears of this kind are fear of contracting pulmonary tuberculosis venereal diseases cancer and heart diseases some authors have suggested that the medical students disease should accurately be referred to as nosophobia rather than hypochondriasis because the quoted studies show a very low percentage of hypochondriacal character of the condition the word nosophobia comes from the greek νόσος nosos for disease
nostalgia for the soviet union or soviet nostalgia is a moral psychological phenomenon in russia and post soviet states as well as persons born in the soviet union living abroad soviet people soviet generation nostalgia for the soviet union could be expressed in nostalgia for the politics of the soviet union society lifestyle culture or simply the aesthetics of the soviet epoch it results mainly from the frustration russia experienced after the dissolution of the soviet union subsequently the economy was changed from a socialist planned economy to capitalism which eventuated the rise of russian oligarchs see gazprom the living standard subsequently fell and gave rise to a renaissance of russian nationalism on april 25 2005 the president of russia vladimir putin stated that the dissolution of the soviet union was a major geopolitical disaster of the 20 th century
notalgia paraesthetica or notalgia paresthetica also known as hereditary localized pruritus posterior pigmented pruritic patch and subscapular pruritus is a chronic sensory neuropathy notalgia paraesthetica is a common localized itch affecting mainly the interscapular area especially the t 2 – t 6 dermatomes but occasionally with a more widespread distribution involving the shoulders back and upper chest the characteristic symptom is pruritus itch or sensation that makes a person want to scratch on the back usually on the left hand side below the shoulder blade mid to upper back it is occasionally accompanied by pain paresthesia pins and needles or hyperesthesia unusual or pathologically increased sensitivity of the skin to sensory stimuli such as pain heat cold or touch which results in a well circumscribed hyperpigmentation of a skin patch in the affected area the causes or origin of this condition etiology have not yet been completely defined patients are usually older persons
the notch of rivinus is a small defect in the posterior edge of the bony annular tympanic ring the defect is located just superior to the tympano mastoid suture line in the posterior ear canal following identification of the spine of henle it is possible to follow the tympano mastoid suture line medially towards the annular ring at this location the chorda tympani nerve is often identified just superior to this the notch of rivinus can be seen and the neck of the malleus occupies the notch and often is the superior limit of a tympanomeatal flap etymology augustus q rivinus german anatomist 1652 – 1723 a deficiency in the tympanic sulcus of the ear that forms an attachment for the flaccid part of the tympanic membrane and the mallear folds also called rivinus incisure tympanic incisure
in psychology novelty seeking ns is a personality trait associated with exploratory activity in response to novel stimulation impulsive decision making extravagance in approach to reward cues and quick loss of temper and avoidance of frustration it is measured in the tridimensional personality questionnaire as well as the later version temperament and character inventory and is considered one of the temperament dimensions of personality like the other temperament dimensions it has been found to be highly heritable high ns has been suggested to be related to low dopaminergic activity in the revised version of the temperament and character inventory tci r novelty seeking consists of the following four subscales 1 exploratory excitability ns 1 2 impulsiveness ns 2 3 extravagance ns 3 4 disorderliness ns 4
in mathematics a nowhere continuous function also called an everywhere discontinuous function is a function that is not continuous at any point of its domain if f is a function from real numbers to real numbers then f x is nowhere continuous if for each point x there is an ε 0 such that for each δ 0 we can find a point y such that 0 x − y δ and f x − f y ≥ ε therefore no matter how close we get to any fixed point there are even closer points at which the function takes not nearby values more general definitions of this kind of function can be obtained by replacing the absolute value by the distance function in a metric space or by using the definition of continuity in a topological space
nowlur is a neighbourhood and a part of urban notified area of amaravati the state capital of the indian state of andhra pradesh it was an out growth of mangalagiri municipality in guntur district prior to its merger in the urban area of the state capital
in chemistry the noyori asymmetric hydrogenation of ketones is a chemical reaction for the enantioselective hydrogenation of ketone aldehydes and imines this reaction exploits using chiral ruthenium catalysts introduced by ryoji noyori he shared half of the nobel prize in chemistry in 2001 with william s knowles for the study of the asymmetric hydrogenation binap ru catalyst is used for the asymmetric hydrogenation of functionalized ketones and binap diamine ru catalyst is used for the asymmetric hydrogenation of simple ketones these hydrogenations are used in the production of several drugs such as the antibacterial levofloxin the antibiotic carbapenem and the antipsychotic agent bms 181100 noyori hydrogenation
the nozaki – hiyama – kishi reaction is a nickel chromium coupling reaction forming an alcohol from the reaction of an aldehyde with an allyl or vinyl halide in their original 1977 publication tamejiro hiyama and hitoshi nozaki reported on a chromium ii salt solution prepared by reduction of chromic chloride by lithium aluminium hydride to which was added benzaldehyde and allyl chloride nhk reaction 1977 compared to grignard reactions this reaction is very selective towards aldehydes with large tolerance towards a range of functional groups such as ketones esters amides and nitriles enals give exclusively 1 2 addition solvents of choice are dmf and dmso one solvent requirement is solubility of the chromium salts nozaki hiyama kishi reaction is a useful method for preparing medium size rings in 1983 the scope was extended by the same authors to include vinyl halides or triflates and aryl halides it was observed that the success of the reaction depended on the source of chromium ii chloride and in 1986 it was found that this is due to nickel impurities since then nickel ii chloride is used as a co catalyst nhk reaction 1986 nozaki in the same year yoshito kishi et al independently discovered the beneficial effects of nickel in his quest for palytoxin nhk reaction kiski 1986 palladium acetate was also found to be an effective cocatalyst
a nuchal cord occurs when the umbilical cord becomes wrapped around the fetal neck 360 degrees nuchal cords are not very common with prevalence rates of 6 to 37 up to half of nuchal cords resolve before delivery
a nuchal type fibroma is a rare benign proliferation involving the dermis and subcutaneous tissues that is a collection of dense hypocellular bundles of collagen with entrapped adipocytes and increased numbers of small nerves it is no longer called a nuchal fibroma but instead a nuchal type fibroma since it develops in other anatomic sites there is no known etiology
nuclear chemistry is the subfield of chemistry dealing with radioactivity nuclear processes such as nuclear transmutation and nuclear properties it is the chemistry of radioactive elements such as the actinides radium and radon together with the chemistry associated with equipment such as nuclear reactors which are designed to perform nuclear processes this includes the corrosion of surfaces and the behavior under conditions of both normal and abnormal operation such as during an accident an important area is the behavior of objects and materials after being placed into a nuclear waste storage or disposal site it includes the study of the chemical effects resulting from the absorption of radiation within living animals plants and other materials the radiation chemistry controls much of radiation biology as radiation has an effect on living things at the molecular scale to explain it another way the radiation alters the biochemicals within an organism the alteration of the biomolecules then changes the chemistry which occurs within the organism this change in chemistry then can lead to a biological outcome as a result nuclear chemistry greatly assists the understanding of medical treatments such as cancer radiotherapy and has enabled these treatments to improve it includes the study of the production and use of radioactive sources for a range of processes these include radiotherapy in medical applications the use of radioactive tracers within industry science and the environment and the use of radiation to modify materials such as polymers it also includes the study and use of nuclear processes in non radioactive areas of human activity for instance nuclear magnetic resonance nmr spectroscopy is commonly used in synthetic organic chemistry and physical chemistry and for structural analysis in macromolecular chemistry
nuclear electronics is a subfield of electronics concerned with the design and use of high speed electronic systems for nuclear physics and elementary particle physics research and for industrial and medical use essential elements of such systems include fast detectors for charged particles discriminators for separating them by energy counters for counting the pulses produced by individual particles fast logic circuits including coincidence and veto gates for identification of particular types of complex particle events and pulse height analyzers phas for sorting and counting gamma rays or particle interactions by energy for spectral analysis
in nuclear physics nuclear fusion is a nuclear reaction in which two or more atomic nuclei come close enough to form one or more different atomic nuclei and subatomic particles neutrons and or protons the difference in mass between the products and reactants is manifested as the release of large amounts of energy this difference in mass arises due to the difference in atomic binding energy between the atomic nuclei before and after the reaction fusion is the process that powers active or main sequence stars or other high magnitude stars the fusion process that produces a nucleus lighter than iron 56 or nickel 62 will generally yield a net energy release these elements have the smallest mass per nucleon and the largest binding energy per nucleon respectively fusion of light elements toward these releases energy an exothermic process while a fusion producing nuclei heavier than these elements will result in energy retained by the resulting nucleons and the resulting reaction is endothermic the opposite is true for the reverse process nuclear fission this means that the lighter elements such as hydrogen and helium are in general more fusable while the heavier elements such as uranium and plutonium are more fissionable the extreme astrophysical event of a supernova can produce enough energy to fuse nuclei into elements heavier than iron following the discovery of quantum tunneling by physicist friedrich hund in 1929 robert atkinson and fritz houtermans used the measured masses of light elements to predict that large amounts of energy could be released by fusing small nuclei building upon the nuclear transmutation experiments by ernest rutherford carried out several years earlier the laboratory fusion of hydrogen isotopes was first accomplished by mark oliphant in 1932 during the remainder of that decade the steps of the main cycle of nuclear fusion in stars were worked out by hans bethe research into fusion for military purposes began in the early 1940 s as part of the manhattan project fusion was accomplished in 1951 with the greenhouse item nuclear test nuclear fusion on a large scale in an explosion was first carried out on november 1 1952 in the ivy mike hydrogen bomb test research into developing controlled thermonuclear fusion for civil purposes also began in earnest in the 1950 s and it continues to this day
nuclear magnetic resonance nmr is a physical phenomenon in which nuclei in a magnetic field absorb and re emit electromagnetic radiation this energy is at a specific resonance frequency which depends on the strength of the magnetic field and the magnetic properties of the isotope of the atoms in practical applications the frequency is similar to vhf and uhf television broadcasts 60 – 1000 mhz nmr allows the observation of specific quantum mechanical magnetic properties of the atomic nucleus many scientific techniques exploit nmr phenomena to study molecular physics crystals and non crystalline materials through nuclear magnetic resonance spectroscopy nmr is also routinely used in advanced medical imaging techniques such as in magnetic resonance imaging mri all isotopes that contain an odd number of protons and or neutrons see isotope have an intrinsic magnetic moment and angular momentum in other words a nonzero spin while all nuclides with even numbers of both have a total spin of zero the most commonly studied nuclei are 1 h and 13 c although nuclei from isotopes of many other elements e g 2 h 6 li 10 b 11 b 14 n 15 n 17 o 19 f 23 na 29 si 31 p 35 cl 113 cd 129 xe 195 pt have been studied by high field nmr spectroscopy as well a key feature of nmr is that the resonance frequency of a particular substance is directly proportional to the strength of the applied magnetic field it is this feature that is exploited in imaging techniques if a sample is placed in a non uniform magnetic field then the resonance frequencies of the sample s nuclei depend on where in the field they are located since the resolution of the imaging technique depends on the magnitude of magnetic field gradient many efforts are made to develop increased field strength often using superconductors the effectiveness of nmr can also be improved using hyperpolarization and or using two dimensional three dimensional and higher dimensional multi frequency techniques the principle of nmr usually involves two sequential steps the alignment polarization of the magnetic nuclear spins in an applied constant magnetic field b 0 the perturbation of this alignment of the nuclear spins by employing an electro magnetic usually radio frequency rf pulse the required perturbing frequency is dependent upon the static magnetic field h 0 and the nuclei of observation the two fields are usually chosen to be perpendicular to each other as this maximizes the nmr signal strength the resulting response by the total magnetization m of the nuclear spins is the phenomenon that is exploited in nmr spectroscopy and magnetic resonance imaging both use intense applied magnetic fields h 0 in order to achieve dispersion and very high stability to deliver spectral resolution the details of which are described by chemical shifts the zeeman effect and knight shifts in metals nmr phenomena are also utilized in low field nmr nmr spectroscopy and mri in the earth s magnetic field referred to as and in several types of magnetometers
the explosive yield of a nuclear weapon is the amount of energy released when that particular nuclear weapon is detonated usually expressed as a tnt equivalent the standardized equivalent mass of trinitrotoluene which if detonated would produce the same energy discharge either in kilotons kt — thousands of tons of tnt in megatons mt — millions of tons of tnt or sometimes in terajoules tj an explosive yield of one terajoule is 0 239 kt of tnt because the accuracy of any measurement of the energy released by tnt has always been problematic the conventional definition accepted since the dawn of the atomic age is that one kiloton of tnt is simply to be 1012 calories equivalent which is only approximately equal to the energy yield of 1 000 tons of tnt the yield to weight ratio is the amount of weapon yield compared to the mass of the weapon the practical maximum yield to weight ratio for fusion weapons thermonuclear weapons has been estimated to six megatons of tnt per metric ton of bomb mass 25 tj kg yields of 5 2 megatons ton and higher have been reported for large weapons constructed for single warhead use in the early 1960 s since this time the smaller warheads needed to achieve the increased net damage efficiency bomb damage bomb weight of multiple warhead systems has resulted in decreases in the yield weight ratio for single modern warheads
in molecular biology hybridization or hybridisation is a phenomenon in which single stranded deoxyribonucleic acid dna or ribonucleic acid rna molecules anneal to complementary dna or rna though a double stranded dna sequence is generally stable under physiological conditions changing these conditions in the laboratory generally by raising the surrounding temperature will cause the molecules to separate into single strands these strands are complementary to each other but may also be complementary to other sequences present in their surroundings lowering the surrounding temperature allows the single stranded molecules to anneal or “ hybridize ” to each other dna replication and transcription of dna into rna both rely upon nucleotide hybridization as do molecular biology techniques including southern blots and northern blots the polymerase chain reaction pcr and most approaches to dna sequencing
in organic chemistry a nucleophilic addition reaction is an addition reaction where a chemical compound with an electron deficient or electrophilic double or triple bond a π bond reacts with electron rich reactant termed a nucleophile with disappearance of the double bond and creation of two new single or σ bonds the reactions are involved in the biological synthesis of compounds in the metabolism of every living organism and are used by chemists in academia and industries such as pharmaceuticals to prepare most new complex organic chemicals and so are central to organic chemistry addition reactions require the presence of groups with multiple bonds in the electrophile carbon – heteroatom multiple bonds as in carbonyls imines and nitriles or carbon – carbon double or triple bonds
the most important of these is the snar mechanism where electron withdrawing groups activate the ring towards nucleophilic attack for example if there are nitro functional groups positioned ortho or para to the halide leaving group
nullisomic is a genetic condition involving the lack of one of the normal chromosomal pairs for a species 2 n 2 humans with this condition will not survive
numa numa is an internet phenomenon based on a video by american vlogger gary brolsma made after the song dragostea din tei as performed by o zone brolsma s video entitled numa numa song was released on december 6 2004 on the website newgrounds com and shows brolsma lip synching the hit song with lively gesticulations and dance moves the video title is derived from the romanian words nu mă nu mă that occur in the refrain of o zone s song it was the first numa numa themed video to gain widespread attention less than three months after the release it had been viewed more than two million times on the debut website alone numa numa song has since spawned many parody videos including those created for the new numa contest sponsored by brolsma which promised us 45 000 in prize money for submissions his original video was named 41 st in the 2006 broadcast of 100 greatest funny moments by channel 4 in the uk the video was featured on channel 4 s virtually famous and entered its hall of fame and was ranked 1 in vh 1 s 40 greatest internet superstars in march 2007
the number portability administration center npac is a function of the federal communications commission fcc in the united states it administers the routing of telephone calls and text messages sms for the telecommunications industry and its customers as such it facilitates local number portability in the united states and canada
numeracy is the ability to reason and to apply simple numerical concepts basic numeracy skills consist of comprehending fundamental arithmetics like addition subtraction multiplication and division for example if one can understand simple mathematical equations such as 2 2 4 then one would be considered possessing at least basic numeric knowledge substantial aspects of numeracy also include number sense operation sense computation measurement geometry probability and statistics a numerically literate person can manage and respond to the mathematical demands of life by contrast innumeracy the lack of numeracy can have a negative impact numeracy has an influence on career decisions and risk perception towards health decisions for example innumeracy distorts risk perception towards health decisions and may negatively affect economic choices greater numeracy has been associated with reduced susceptibility to framing effects less influence of nonnumerical information such as mood states and greater sensitivity to different levels of numerical risk
numerical diffusion is a difficulty with computer simulations of continua such as fluids wherein the simulated medium exhibits a higher diffusivity than the true medium this phenomenon can be particularly egregious when the system should not be diffusive at all for example an ideal fluid acquiring some spurious viscosity in a numerical model
in software engineering and mathematics numerical error is the combined effect of two kinds of error in a calculation the first is caused by the finite precision of computations involving floating point or integer values the second usually called truncation error is the difference between the exact mathematical solution and the approximate solution obtained when simplifications are made to the mathematical equations to make them more amenable to calculation the term truncation comes from the fact that either these simplifications usually involve the truncation of an infinite series expansion so as to make the computation possible and practical or because the least significant bits of an arithmetic operation are thrown away floating point numerical error is often measured in ulp unit in the last place
numerical resistivity is a problem in computer simulations of ideal magnetohydrodynamics mhd it is a form of numerical diffusion in near ideal mhd systems the magnetic field can diffuse only very slowly through the plasma or fluid of the system it is rate limited by the inverse of the resistivity of the fluid in eulerian simulations where the field is arbitrarily aligned compared to the simulation grid the numerical diffusion rate takes the form similar to an additional resistivity causing non physical and sometimes bursty magnetic reconnection in the simulation numerical resistivity is a function of resolution alignment of the magnetic field with the grid and numerical method in general numerical resistivity will not behave isotropically and there can be different effective numerical resistivities in different parts of the computational domain for current 2005 simulations of the solar corona and inner heliosphere this numerical effect can be several orders of magnitude larger than the physical resistivity of the plasma
the numerosity adaptation effect is a perceptual phenomenon in numerical cognition which demonstrates non symbolic numerical intuition and exemplifies how numerical percepts can impose themselves upon the human brain automatically this effect was first described in 2008 presently this effect is described only for controlled experimental conditions in the illustration a viewer should have a strong impression that the left display lower figure is more numerous than the right after 30 seconds of viewing the adaptation upper figure although both have exactly the same number of dots the viewer might also underestimate the number of dots presented in the display both effects are resistant to manipulation of the non numerical parameters of the display thus this effect cannot be simply explained in terms of size density or contrast perhaps the most astonishing aspect of these effects is that they happen immediately and without conscious control i e knowing that the numbers are equal would not hamper their happening this points to the operation of a special and largely automatic processing system as noted by burr ross 2008
nummular dermatitis also known as discoid eczema microbial eczema nummular eczema and nummular neurodermatitis is one of the many forms of dermatitis also known as discoid dermatitis it is characterized by round or oval shaped itchy lesions the name comes from the latin word nummus which means coin
nuptial gifts are food items or inedible tokens that are transferred to females by males during courtship or copulation inedible tokens may include items such as a fragment of leaf or twig a seed tuft or a silk balloon in many species of animals including birds insects and spiders this takes the form of a food item that is transferred from a male to a female just prior to copulation this is a behaviour known as courtship feeding in some species of insects such as katydids the nuptial gift is packaged with the sperm of the male the package is an edible spermatophore these extra nutrients in the sperm are assimilated by the female and are thought to enhance the fitness of the offspring produced thus increasing the probability that a male passes on its genes nuptial gifts may therefore be classified into oral and seminal gifts nuptial gifts may also be tokens that do not have any direct value as food but may serve as an indicator of male fitness
in general biology or reproductive physiology the term nurse cell is defined as a cell which provides food helps other cells and provides stability to their neighboring cells the term nurse cell is used in several unrelated ways in different scientific fields
the nurse scheduling problem nsp also called the nurse rostering problem nrp is the operations research problem of finding an optimal way to assign nurses to shifts typically with a set of hard constraints which all valid solutions must follow and a set of soft constraints which define the relative quality of valid solutions solutions to the nurse scheduling problem can be applied to constrained scheduling problems in other fields the nurse scheduling problem has been studied since before 1969 and is known to have np hard complexity
nursemaid s elbow babysitter s elbow or pulled elbow is a dislocation of the elbow joint caused by a sudden pull on the extended pronated forearm such as by an adult tugging on an uncooperative child or by swinging the child by the arms during play the technical term for the injury is radial head subluxation
nutcracker esophagus or hypertensive peristalsis is a disorder of the movement of the esophagus characterized by contractions in the smooth muscle of the esophagus in a normal sequence but at an excessive amplitude or duration nutcracker esophagus is one of several motility disorders of the esophagus including achalasia and diffuse esophageal spasm it causes difficulty swallowing or dysphagia to both solid and liquid foods and can cause significant chest pain it may also be asymptomatic nutcracker esophagus can affect people of any age but is more common in the sixth and seventh decades of life the diagnosis is made by an esophageal motility study esophageal manometry which evaluates the pressure of the esophagus at various points along its length the term nutcracker esophagus comes from the finding of increased pressures during peristalsis with a diagnosis made when pressures exceed 180 mmhg this has been likened to the pressure of a mechanical nutcracker the disorder does not progress and is not associated with any complications as a result treatment of nutcracker esophagus targets control of symptoms only
the nutcracker syndrome ncs — is a manifest variant of nutcracker phenomenon renal vein entrapment syndrome or mesoaortic compression of the left renal vein it results most commonly from the compression of the left renal vein between the abdominal aorta aa and superior mesenteric artery sma although other variants exist the name derives from the fact that in the sagittal plane and or transverse plane the sma and aa with some imagination appear to be a nutcracker crushing a nut the renal vein there is a wide spectrum of clinical presentations and diagnostic criteria are not well defined which frequently results in delayed or incorrect diagnosis this condition is not to be confused with superior mesenteric artery syndrome which is the compression of the third portion of the duodenum by the sma and the aa
nutricosmetics are nutritional supplements which purposes to support the function and the structure of the skin many micronutrients have this effect vitamin c for example has a well established anti oxidant effect that reduces the impact of free radicals in the skin it also has a vital function in the production of collagen in the dermis other micronutrients such as some omega 3 fatty acids carotenes and flavonoids protect the skin from the damaging effects of ultraviolet light exposure which may lead to accelerated skin aging and wrinkle formation one of the pioneers in this field and by many considered as the father of internal skincare is the swedish biochemist ake dahlgren he invented the world s first nutricosmetic in the late 1980 s called imedeen since the 1990 s sales of nutricosmetics have increased dramatically to over 1 billion usd annually
nutrient sensing is a cell s ability to recognize and respond to fuel substrates such as glucose each type of fuel used by the cell requires an alternate pathway of utilization and accessory molecules in order to conserve resources a cell will only produce molecules that it needs at the time the level and type of fuel that is available to a cell will determine the type of enzymes it needs to express from its genome for utilization receptors on the cell membrane s surface designed to be activated in the presence of specific fuel molecules communicate to the cell nucleus via a means of cascading interactions in this way the cell is aware of the available nutrients and is able to produce only the molecules specific to that nutrient type
nutritional anemia refers to types of anemia that can be directly attributed to nutritional disorders examples include iron deficiency anemia and pernicious anemia it is often discussed in a pediatric context
nutritional deficiency eczema is a pattern of eczema with localized thickened scaling patches that have some characteristics of nummular eczema seborrheic dermatitis and neurodermatitis that may be seen in alcoholics
nutritional muscular dystrophy also called nutritional myopathy or white muscle disease is a muscle disease of lambs calves and foals and adult horses due to deficiency in selenium and or vitamin e the condition is observed in all breeds and sexes of lambs from birth to three month of age its frequency increases with upgrading of sheep breed for increased muscling especially in areas with selenium deficiency in soils in dairy breeds the occurs in calves from some days after birth until four months of age but in rustic breeds or beef cattle heifers and young steers up to 12 months can also be affected
nyctalopia ˌnɪktəlˈoʊpiə from greek νύκτ nykt night ἀλαός alaos blind not seeing and ὄψ ops eye also called night blindness is a condition making it difficult or impossible to see in relatively low light it is a symptom of several eye diseases night blindness may exist from birth or be caused by injury or malnutrition for example a lack of vitamin a it can be described as insufficient adaptation to darkness the most common cause of nyctalopia is retinitis pigmentosa a disorder in which the rod cells in the retina gradually lose their ability to respond to the light patients suffering from this genetic condition have progressive nyctalopia and eventually their daytime vision may also be affected in x linked congenital stationary night blindness from birth the rods either do not work at all or work very little but the condition doesn t get worse another cause of night blindness is a deficiency of retinol or vitamin a found in fish oils liver and dairy products the opposite problem the inability to see in bright light is known as hemeralopia and is much rarer since the outer area of the retina is made up of more rods than cones loss of peripheral vision often results in night blindness individuals suffering from night blindness not only see poorly at night but also require extra time for their eyes to adjust from brightly lit areas to dim ones contrast vision may also be greatly reduced rods contain a receptor protein called rhodopsin when light falls on rhodopsin it undergoes a series of conformational changes ultimately generating electrical signals which are carried to the brain via the optic nerve in the absence of light rhodopsin is regenerated the body synthesizes rhodopsin from vitamin a which is why a deficiency in vitamin a causes poor night vision refractive vision correction surgery especially prk with the complication of haze may rarely cause a reduction in best night time acuity due to the impairment of contrast sensitivity function csf which is induced by intraocular light scatter resulting from surgical intervention in the natural structural integrity of the cornea
nystagmus is a condition of involuntary or voluntary in rare cases eye movement acquired in infancy or later in life that may result in reduced or limited vision due to the involuntary movement of the eye it is often called dancing eyes in a normal condition while the head rotates about any axis distant visual images are sustained by rotating eyes in the opposite direction on the respective axis the semicircular canals in the vestibule sense angular acceleration these send signals to the nuclei for eye movement in the brain from here a signal is relayed to the extraocular muscles to allow one ’ s gaze to fixate on one object as the head moves nystagmus occurs when the semicircular canals are being stimulated while the head is not in motion the direction of ocular movement is related to the semicircular canal that is being stimulated there are two key forms of nystagmus pathological and physiological with variations within each type nystagmus may be caused by congenital disorders acquired or central nervous system disorders toxicity pharmaceutical drugs alcohol or rotational movement previously considered untreatable in recent years several pharmaceutical drugs have been identified for treatment of nystagmus nystagmus is occasionally associated with vertigo
o javanese o jawa or o spelling is a phenomenon that is caused by contradiction between standard javanese spelling and standard indonesian spelling eyd in standard indonesian spelling word a can only pronounced a while in standard javanese spelling word a have two tone i e a and ɔ in consequence the indonesian words that borrowed from javanese that have syntax a on its writings usually pronounced a although in javanese its pronounced ɔ hence the words a that pronounced o become written as o to simplify for readers that are not from javanese background for example susilo bambang yudhoyono if written by standard javanese spelling should be susila bambang yudhayana while surabaya pronounced surɔbɔjɔ hamengkubuwono hamengkubuwana mangkunegoro mangkunegara
oh 24 olduvai hominid № 24 nicknamed twiggy is a fossilized skull of the species homo habilis it was discovered in olduvai gorge tanzania by peter nzube in 1968 the skull was found crushed almost flat and was therefore named after the famously skinny model of the time twiggy estimated at about 1 8 mya million years old the cranium was found crushed flat and cemented together with a mass coating of limestone originally there was very little interest placed on the discovery of the skull but after much effort by scientist ron clarke the skull was finally reconstructed and examined thoroughly despite this effort there still is a good deal of distortion from the fossilization processes that took place the small cranial capacity estimated at about 590 600 cc cubic centimeters is in part attributed to this cranial distortion oh 24 s face is described as being prognathic projecting forward under the nose as in other fossils from the homo habilis family but not quite to the extent of earlier australopithecus species besides manifesting lesser prognathism than the australopithecines oh 24 also portrays a larger cranial vault indicating an expansion in brain size from its ancestor and the reduction of facial prognathisim typical of the evolution of early homo the individual s third molars had erupted which indicates that oh 24 twiggy was an adult at death yet these molars show no sign of wear the points on the crowns of the teeth are still sharp and show little sign of abrasion by rough food matter indicating that this individual died soon after the eruption of these molars like the other fossils of homo habilis oh 24 also manifests the slightly small teeth set in a u shaped arch being one of the oldest fossils of homo habilis oh 24 has been used to settle many disputes about splitting some of the early homo fossils that have been found into homo rudolfensis and homo habilis or lumping them together into one single species homo habilis some of the highly disputed fossils are knm er 1813 which most agree is a female homo habilis and knm er 1470 which many argue has various anatomical differences to the previously known homo habilis fossils that should make it be classified into the homo rudolfensis species replica made with a 3 d printer
the os tan is an internet phenomenon or meme that originated within the japanese futaba channel the os tan are the moe anthropomorphism personification of several operating systems by various amateur japanese artists the os tan are typically depicted as women with the os tan representative of microsoft windows operating systems usually depicted as sisters of varying ages though initially appearing only in fan work the os tans proved popular enough that microsoft branches in singapore and taiwan used the os tan concept as the basis for ad campaigns for internet explorer and microsoft silverlight respectively
oslam syndrome is a rare autosomal dominant hereditary disorder its name is an initialism of osteosarcoma limb anomalies and erythroid macrocytosis with megaloblastic marrow syndrome oslam syndrome was recognised and described by mulvilhill et al as a syndrome that increases susceptibility to tumours and is characterised by an impaired regulation of bone and marrow development individuals with oslam syndrome have an elevated risk of bone cancer limb abnormalities and enlarged red blood cells
the ozi rule is a consequence of quantum chromodynamics qcd that explains why certain decay modes appear less frequently than otherwise might be expected it was independently proposed by susumu okubo george zweig and jugoro iizuka in the 1960 s it states that any strongly occurring process will be suppressed if through only the removal of internal gluon lines its feynman diagram can be separated into two disconnected diagrams one containing all of the initial state particles and one containing all of the final state particles an example of such a suppressed decay is φ → π π − π 0 it would be expected that this decay mode would dominate over other decay modes such as φ → k k − which have much lower q values in actuality it is seen that φ decays to kaons 84 of the time suggesting the decay path to pions is suppressed an explanation of the ozi rule can be seen from the decrease of the coupling constant in qcd with increasing energy or momentum transfer for the ozi suppressed channels the gluons must have high q 2 at least as much as the rest mass energies of the quarks into which they decay and so the coupling constant will appear small to these gluons a further example is given by the decays of excited states of charmonium bound state of charm quark and antiquark for states lighter than the charged d mesons the decay must proceed just like the above example into three pions with three virtual gluons mediating the interaction each of which must have enough energy to produce a quark antiquark pair but above the d meson threshold the original valence quarks need not annihilate they can propagate into the final states in this case only two gluons are required which share the energy of the light quark antiquark pair that is spontaneously nucleated they are thus lower in energy than the three gluons of the ozi suppressed annihilation the suppression arises from both the smaller values of the qcd coupling constant at high energies as well as the greater number of interaction vertices
oak wilt is a fungal disease affecting oak trees caused by the fungus ceratocystis fagacearum symptoms vary by tree species but generally consist of leaf discoloration wilt defoliation and death the fungus spreads from diseased to healthy trees from insects or by connections between tree roots management of the disease historically meant preventing infection by avoiding tree wounds removing diseased trees and breaking root connections with vibratory plows trenchers rocksaws or hoes present methods focus on the area of monocultures and restoring correct ecosystems using soils fungicide treatments used in urban areas are available and are mostly preventative as well oak wilt is an important disease of oak for timber production and of oak trees in urban areas
oase 2 is a fossilized human skull believed to date from sometime in the first 5 000 years of human habitation of europe it was found in the peștera cu oase cave in southwestern romania with other human samples from the time the skull has the same proportions as modern human craniums and has other features that are neanderthal
obesity is a medical condition in which excess body fat has accumulated to the extent that it may have a negative effect on health people are generally considered obese when their body mass index bmi a measurement obtained by dividing a person s weight by the square of the person s height is over 30 kg m 2 with the range 25 – 30 kg m 2 defined as overweight some east asian countries use lower values obesity increases the likelihood of various diseases particularly heart disease type 2 diabetes obstructive sleep apnea certain types of cancer and osteoarthritis obesity is most commonly caused by a combination of excessive food intake lack of physical activity and genetic susceptibility a few cases are caused primarily by genes endocrine disorders medications or mental illness evidence to support the view that obese people eat little yet gain weight due to a slow metabolism is not generally supported on average obese people have a greater energy expenditure than their thin counterparts due to the energy required to maintain an increased body mass obesity is mostly preventable through a combination of social changes and personal choices changes to diet and exercising are the main treatments diet quality can be improved by reducing the consumption of energy dense foods such as those high in fat and sugars and by increasing the intake of dietary fiber medications may be taken along with a suitable diet to reduce appetite or decrease fat absorption if diet exercise and medication are not effective a gastric balloon or surgery may be performed to reduce stomach volume or bowel length leading to feeling full earlier or a reduced ability to absorb nutrients from food obesity is a leading preventable cause of death worldwide with increasing rates in adults and children in 2014 600 million adults 13 and 42 million children under the age of five were obese obesity is more common in women than men authorities view it as one of the most serious public health problems of the 21 st century obesity is stigmatized in much of the modern world particularly in the western world though it was seen as a symbol of wealth and fertility at other times in history and still is in some parts of the world in 2013 the american medical association classified obesity as a disease
obesity hypoventilation syndrome also known as pickwickian syndrome is a condition in which severely overweight people fail to breathe rapidly enough or deeply enough resulting in low blood oxygen levels and high blood carbon dioxide co 2 levels many people with this condition also frequently stop breathing altogether for short periods of time during sleep obstructive sleep apnea resulting in many partial awakenings during the night which leads to continual sleepiness during the day the disease puts strain on the heart which eventually may lead to the symptoms such as heart failure leg swelling and various other related symptoms the most effective treatment is weight loss but it is often possible to relieve the symptoms by nocturnal ventilation with positive airway pressure cpap or related methods obesity hypoventilation syndrome is defined as the combination of obesity body mass index above 30 kg m 2 hypoxemia falling oxygen levels in blood during sleep and hypercapnia increased blood carbon dioxide levels during the day resulting from hypoventilation excessively slow or shallow breathing the disease has been known since the 1950 s initially as pickwickian syndrome in reference to a dickensian character but currently under a more descriptive name
in computer vision the problem of object categorization from image search is the problem of training a classifier to recognize categories of objects using only the images retrieved automatically with an internet search engine ideally automatic image collection would allow classifiers to be trained with nothing but the category names as input this problem is closely related to that of content based image retrieval cbir where the goal is to return better image search results rather than training a classifier for image recognition traditionally classifiers are trained using sets of images that are labeled by hand collecting such a set of images is often a very time consuming and laborious process the use of internet search engines to automate the process of acquiring large sets of labeled images has been described as a potential way of greatly facilitating computer vision research
the object pool pattern is a software creational design pattern that uses a set of initialized objects kept ready to use – a pool – rather than allocating and destroying them on demand a client of the pool will request an object from the pool and perform operations on the returned object when the client has finished it returns the object to the pool rather than destroying it this can be done manually or automatically object pools are primarily used for performance in some circumstances object pools significantly improve performance object pools complicate object lifetime as objects obtained from and returned to a pool are not actually created or destroyed at this time and thus require care in implementation
obligatory possession is a linguistic phenomenon common in languages with nouns inflected for possessor certain words commonly kinship terms and body parts cannot occur without a possessor the world atlas of language structures wals lists 43 languages in its 244 language sample as having obligatory possession languages with obligatory possession are concentrated in new guinea and in north and south america generally obligatory possession is found throughout a family e g algonquian languages represented by plains cree in the wals sample or mayan languages represented by tzutujil in the wals sample but not all athabaskan languages have it slavey does not have obligatory possession but navajo does obligatory possession is also present in the language isolate haida obligatory possession is sometimes called inalienable possession inalienable possession is a semantic notion i e largely dependent on the way a culture structures the world while obligatory possession is a property of morphemes in general nouns with the property of requiring obligatorily possession are notionally inalienably possessed but the fit is rarely if ever perfect
observational error or measurement error is the difference between a measured value of quantity and its true value in statistics an error is not a mistake variability is an inherent part of things being measured and of the measurement process measurement errors can be divided into two components random error and systematic error random errors are errors in measurement that lead to measurable values being inconsistent when repeated measures of a constant attribute or quantity are taken systematic errors are errors that are not determined by chance but are introduced by an inaccuracy as of observation or measurement inherent in the system systematic error may also refer to an error having a nonzero mean so that its effect is not reduced when observations are averaged
the observer pattern is a software design pattern in which an object called the subject maintains a list of its dependents called observers and notifies them automatically of any state changes usually by calling one of their methods it is mainly used to implement distributed event handling systems the observer pattern is also a key part in the familiar model – view – controller mvc architectural pattern the observer pattern is implemented in numerous programming libraries and systems including almost all gui toolkits the observer pattern can cause memory leaks known as the lapsed listener problem because in basic implementation it requires both explicit registration and explicit deregistration as in the dispose pattern because the subject holds strong references to the observers keeping them alive this can be prevented by the subject holding weak references to the observers related patterns publish – subscribe pattern mediator singleton
obsessive – compulsive disorder ocd is a mental disorder where people feel the need to check things repeatedly perform certain routines repeatedly called rituals or have certain thoughts repeatedly people are unable to control either the thoughts or the activities for more than a short period of time common activities include hand washing counting of things and checking to see if a door is locked some may have difficulty throwing things out these activities occur to such a degree that the person s daily life is negatively affected often they take up more than an hour a day most adults realize that the behaviors do not make sense the condition is associated with tics anxiety disorder and an increased risk of suicide the cause is unknown there appear to be some genetic components with both identical twins more often affected than both non identical twins risk factors include a history of child abuse or other stress inducing event some cases have been documented to occur following infections the diagnosis is based on the symptoms and requires ruling out other drug related or medical causes rating scales such as the yale – brown obsessive compulsive scale can be used to assess the severity other disorders with similar symptoms include anxiety disorder major depressive disorder eating disorders tic disorders and obsessive – compulsive personality disorder treatment involves counselling such as cognitive behavioral therapy cbt and sometimes medication typically selective serotonin reuptake inhibitors ssris cbt for ocd involves increasing exposure to what causes the problems while not allowing the repetitive behavior to occur while clomipramine appears to work as well as ssris it has greater side effects atypical antipsychotics may be useful when used in addition to an ssri in treatment resistant cases but are also associated with an increased risk of side effects without treatment the condition often lasts decades obsessive – compulsive disorder affects about 2 3 of people at some point in their life rates during a given year are about 1 2 and it occurs worldwide it is unusual for symptoms to begin after the age of thirty five and half of people develop problems before twenty males and females are affected about equally in english the phrase obsessive – compulsive is often used in an informal manner unrelated to ocd to describe someone who is excessively meticulous perfectionistic absorbed or otherwise fixated
obsessive – compulsive personality disorder ocpd is a personality disorder characterized by a general pattern of concern with orderliness perfectionism excessive attention to details mental and interpersonal control and a need for control over one s environment at the expense of flexibility openness to experience and efficiency workaholism and miserliness are also seen often in those with this personality disorder rituals are performed to the point of excluding leisure activities and friendships persons affected with this disorder may find it hard to relax always feeling that time is running out for their activities and that more effort is needed to achieve their goals they may plan their activities down to the minute — a manifestation of the compulsive tendency to keep control over their environment and to dislike unpredictable things as things they cannot control the cause of ocpd is unknown this is a distinct disorder from obsessive – compulsive disorder ocd and the relation between the two is contentious some but not all studies have found high comorbidity rates between the two disorders and both may share outside similarities – rigid and ritual like behaviors for example hoarding orderliness and a need for symmetry and organization are often seen in people with either disorder attitudes toward these behaviors differ between people affected with either of the disorders for people with ocd these behaviors are unwanted and seen as unhealthy being the product of anxiety inducing and involuntary thoughts while for people with ocpd they are egosyntonic that is they are perceived by the subject as rational and desirable being the result of for example a strong adherence to routines a natural inclination towards cautiousness or a desire to achieve perfection ocpd occurs in about 2 – 8 of the general population and 8 – 9 of psychiatric outpatients the disorder more often occurs in men
obstetric fistula or vaginal fistula is a medical condition in which a fistula hole develops between either the rectum and vagina see rectovaginal fistula or between the bladder and vagina see vesicovaginal fistula after severe or failed childbirth when adequate medical care is not available the united nations population fund unfpa defines obstetric fistula as “ a childbirth injury that has been largely neglected despite the devastating impact it has on the lives of affected girls and women it is usually caused by prolonged obstructed labour without timely medical intervention — typically an emergency caesarean section during unassisted prolonged obstructed labour the sustained pressure of the baby ’ s head on the mother ’ s pelvic bone damages soft tissues creating a hole — or fistula — between the vagina and the bladder and or rectum the pressure deprives blood flow to the tissue leading to necrosis eventually the dead tissue comes away leaving a fistula which causes a constant leaking of urine and or faeces through the vagina ” it is considered a disease of poverty because of its tendency to occur in women in poor countries who do not have health resources comparable to developed nations an estimated 2 million women in sub saharan africa asia the arab region and latin america and the caribbean are living with this injury and some 50 000 to 100 000 new cases develop each year in developed countries the majority of women with of suffer rectovaginal fistula rvf this is caused by episiotomy and forceps vacuum extraction of the baby from the vagina over 80 of rvfs in the usa are obstetric and either preventable or treatable followed in frequency by crohn s disease and radiation a fistula is almost entirely preventable according to health advocates its persistence is a sign that health systems are failing to meet women ’ s essential needs
an obstetric labor complication is a difficulty or abnormality that arises during the process of labor or delivery an example is dystocia
obstetrical bleeding also known as obstetrical hemorrhage and maternal hemorrhage refers to heavy bleeding during pregnancy labor or the puerperium bleeding may be vaginal and external or less commonly but more dangerously internal into the abdominal cavity typically bleeding is related to the pregnancy itself but some forms of bleeding are caused by other events about 4 6 million cases of obstetrical hemorrhage occurred in 2013 it is a major cause of maternal mortality
obstructed labour also known as labour dystocia is when even though the uterus is contracting normally the baby does not exit the pelvis during childbirth due to being physically blocked complications for the baby include not getting enough oxygen which may result in death it increases the risk of the mother getting an infection having uterine rupture or having post partum bleeding long term complications for the mother include obstetrical fistula obstructed labour is said to result in prolonged labour when the active phase of labour is longer than twelve hours the main causes of obstructed labour include a large or abnormally positioned baby a small pelvis and problems with the birth canal abnormal positioning includes shoulder dystocia were the anterior shoulder does not pass easily below the pubic bone risk factors for a small pelvis include malnutrition and a lack of exposure to sunlight causing vitamin d deficiency it is also more common in adolescence as the pelvis may not have finished growing problems with the birth canal include a narrow vagina and perineum which may be due to female genital mutilation or tumors a partograph is often used to track labour progression and diagnose problems this combined with physical examination may identify obstructed labour the treatment of obstructed labour may require cesarean section or vacuum extraction with possible surgical opening of the symphysis pubis other measures include keeping the women hydrated and antibiotics if the membranes have been ruptured for more than 18 hours in africa and asia obstructed labor effects between two and five percent of deliveries in 2013 about 5 1 cases of obstructed labour occurred this resulted in 19 000 deaths down from 29 000 deaths in 1990 about 8 of all deaths related to pregnancy most deaths due to this condition occur in the developing world
obstructive lung disease is a category of respiratory disease characterized by airway obstruction many obstructive diseases of the lung result from narrowing of the smaller bronchi and larger bronchioles often because of excessive contraction of the smooth muscle itself it is generally characterized by inflamed and easily collapsible airways obstruction to airflow problems exhaling and frequent medical clinic visits and hospitalizations types of obstructive lung disease include asthma bronchiectasis bronchitis and chronic obstructive pulmonary disease copd although copd shares similar characteristics with all other obstructive lung diseases such as the signs of coughing and wheezing they are distinct conditions in terms of disease onset frequency of symptoms and reversibility of airway obstruction cystic fibrosis is also sometimes included in obstructive pulmonary disease
obstructive purpura is a skin condition that may result from mechanical obstruction to circulation with resulting stress on the small vessels leading to purpura
obstructive sleep apnea osa is the most common type of sleep apnea and is caused by complete or partial obstructions of the upper airway it is characterized by repetitive episodes of shallow or paused breathing during sleep despite the effort to breathe and is usually associated with a reduction in blood oxygen saturation these episodes of decreased breathing called apneas literally without breath typically last 20 to 40 seconds individuals with osa are rarely aware of difficulty breathing even upon awakening it is often recognized as a problem by others who observe the individual during episodes or is suspected because of its effects on the body osa is commonly accompanied with snoring some use the terms obstructive sleep apnea syndrome or obstructive sleep apnea – hypopnea syndrome to refer to osa which is associated with symptoms during the daytime symptoms may be present for years or even decades without identification during which time the individual may become conditioned to the daytime sleepiness and fatigue associated with significant levels of sleep disturbance individuals who generally sleep alone are often unaware of the condition without a regular bed partner to notice and make them aware of their symptoms as the muscle tone of the body ordinarily relaxes during sleep and the airway at the throat is composed of walls of soft tissue which can collapse it is not surprising that breathing can be obstructed during sleep although a very minor degree of osa is considered to be within the bounds of normal sleep and many individuals experience episodes of osa at some point in life a small percentage of people have chronic severe osa many people experience episodes of osa for only a short period this can be the result of an upper respiratory infection that causes nasal congestion along with swelling of the throat or tonsillitis that temporarily produces very enlarged tonsils the epstein barr virus for example is known to be able to dramatically increase the size of lymphoid tissue during acute infection and osa is fairly common in acute cases of severe infectious mononucleosis temporary spells of osa syndrome may also occur in individuals who are under the influence of a drug such as alcohol that may relax their body tone excessively and interfere with normal arousal from sleep mechanisms
obstructive uropathy is a structural or functional hindrance of normal urine flow sometimes leading to renal dysfunction obstructive nephropathy it is a very broad term and does not imply a location or etiology
obtundation refers to less than full alertness altered level of consciousness typically as a result of a medical condition or trauma the root word obtund means dulled or less sharp cf obtuse angle
an obturator hernia is a rare type of hernia of the pelvic floor in which pelvic or abdominal contents protrudes through the obturator foramen because of differences in anatomy it is much more common in women especially multiparous and older women who have recently lost a lot of weight the diagnosis is often made intraoperatively after presentingwith bowel obstruction a gynecologist may come across this type of hernias as a secondary finding during gynecological open surgery or laparoscopy the howship romberg sign is suggestive of an obturator hernia exacerbated by thigh extension medial rotation and abduction it is characterized by lancilating pain in the medial thigh obturator distribution extending to the knee caused by hernia compression of the obturator nerve
the occam process is a solder free restriction of hazardous substances directive rohs compliant method for use in the manufacturing of electronic circuit boards developed by verdant electronics it combines the usual two steps of the construction of printed circuit boards pcbs followed by the population process of placing various leaded and non leaded electronic components into one process
an occipital bun is a prominent bulge or projection of the occipital bone at the back of the skull it is important in scientific descriptions of classic neanderthal crania while common among many of humankind s ancestors primarily robust relatives rather than gracile the protrusion is relatively rare in modern homo sapiens some scientists suspect occipital buns might correlate with the biomechanics of running another theory attributes them to enlargement of the cerebellum a region of the brain which mediates the timing of motor actions and spatial reasoning there are still some human populations which often exhibit occipital buns a greater proportion of early modern europeans had them but prominent occipital buns in modern populations are now relatively infrequent a study conducted by lieberman pearson and mowbray provides evidence that individuals with narrow heads dolicocephalic or narrow cranial bases and relatively large brains are more likely to have occipital buns as a means of resolving a spatial packing problem
occipital horn syndrome ohs formerly considered a variant of ehlers danlos syndrome is an x linked recessive connective tissue disorder it is caused by a deficiency in the transport of the essential mineral copper associated with mutations in the atp 7 a gene only about 2 3 of children with ohs are thought to have genetically inherited the disorder the other 1 3 do not have the disease in their family history since the disorder is x linked recessive the disease affects more males this is because they do not have a second x chromosome unlike females so essentially are lacking the backup copy with proper function females are much more likely to be carriers only for a female to be affected they must carry two defective x chromosomes not just one the disorder is considered a milder variant of menkes disease
occipital neuralgia also known as c 2 neuralgia or rarely arnold s neuralgia is a medical condition characterized by chronic pain in the upper neck back of the head and behind the eyes these areas correspond to the locations of the lesser and greater occipital nerves wrapped around the greater occipital nerve is the occipital artery which can contribute to the neuralgia the condition is also sometimes characterized by diminished sensation in the affected area symptoms include sharp jabbing intense pains or sensations burning and or pricking feeling
occult pneumonia is a pneumonia that is not observable directly by the eye but can only be shown indirectly especially by radiography occult pneumonia can be made visible by chest x rays the general symptoms cough for more than 10 days and fever for more than 3 days can indicate the presence of occult pneumonia just as a temperature of 39 ° c or higher and a high white blood cell count administration of a pneumococcal vaccine decreases the incidence of occult pneumonia which suggests that streptococcus pneumoniae is a cause of occult pneumonia occult pneumonia however can also be the result of atypical pneumonia although pneumococcal vaccination lowers the prevalence of occult pneumonia it does not make radiographic diagnosis superfluous at patients with prolonged fever cough or leukocytosis etymology the term is derived from the latin occultus hidden secret and pneumonia inflammation of the lungs greek pneuma wind and indo european pleumon floating swimming
occupational acne is caused by several different groups of industrial compounds including coal tar derivatives insoluble cutting oils and chlorinated hydrocarbons chlornaphthalenes chlordiphenyls and chlordiphenyloxides
occupational asthma is an occupational lung disease and a type of asthma like other types of asthma it is characterized by airway inflammation reversible airways obstruction and bronchospasm but it is caused by something in the workplace environment symptoms include shortness of breath tightness of the chest nasal irritation coughing and wheezing the first person to use it in reference to a medical condition was hippocrates and he believed that tailors anglers and metalworkers were more likely to be affected by the disease although much research has been done since the inflammatory component of asthma was recognized only in the 1960 s hypersensitivity pneumonitis is a related condition with many occupational examples e g flock worker s lung farmer s lung and indium lung however although overlapping in many cases hypersensitivity pneumonitis may be distinguished from occupational asthma in that it isn t restricted to only occupational exposure and involves type iii hypersensitivity and type iv hypersensitivity rather than the type i hypersensitivity of asthma also unlike asthma hypersensitivity pneumonitis targets lung alveoli rather than bronchi
the term burnout in psychology was coined by herbert freudenberger in his 1974 staff burnout presumably based on the 1960 novel a burnt out case by graham greene which describes a protagonist suffering from burnout more recently the term brownout has been used in the business world to describe a less serious version of burnout it refers to staff who are disengaged and demotivated in their job role occupational burnout is typically and particularly found within human service professions professions with high levels of burnout include social workers nurses teachers lawyers engineers medical practitioners customer service representatives and police officers one reason why burnout is so prevalent within the human services field is due in part to the high stress work environment and emotional demands of the job maslach and her colleague michael leiter defined the antithesis of burnout as engagement engagement is characterized by energy involvement and efficacy the opposites of exhaustion cynicism and inefficacy bakker et al 2014 in burnout and work engagement the jd – r approach makes the same argument as leiter
occupational cancer is cancer caused by occupational hazards several cancers have been directly tied to occupational hazards including chimney sweeps carcinoma mesothelioma and others
an occupational disease is any chronic ailment that occurs as a result of work or occupational activity it is an aspect of occupational safety and health an occupational disease is typically identified when it is shown that it is more prevalent in a given body of workers than in the general population or in other worker populations the first such disease to be recognised squamous cell carcinoma of the scrotum was identified in chimney sweep boys by sir percival pott in 1775 occupational hazards that are of a traumatic nature such as falls by roofers are not considered to be occupational diseases under the law of workers compensation in many jurisdictions there is a presumption that specific disease are caused by the worker being in the work environment and the burden is on the employer or insurer to show that the disease came about from another cause diseases compensated by national workers compensation authorities are often termed occupational diseases however many countries do not offer compensations for certain diseases like musculoskeletal disorders caused by work e g in norway therefore the term work related diseases is utilized to describe diseases of occupational origin this term however would then include both compensable and non compensable diseases that have occupational origins
occupational hearing loss ohl is hearing loss that occurs as a result of occupational hazards ohl damage to one or both ears from exposures related to one s occupation is a large but preventable problem organizations such as the occupational safety and health administration osha and the national institute for occupational safety and health niosh work with employers and workers to reduce or eliminate completely hazards to hearing occupational hearing loss is one of the most common work related illness in the united states hazards to the hearing of workers include industrial noise and exposure to various ototoxic chemicals these exposures may also interact to cause more damage than either one would by itself many chemicals have not been tested for ototoxicity so unknown threats may exist a 2016 study by niosh found that the mining sector had the highest prevalence of hearing impairment at 17 followed by the construction sector 16 and the manufacturing sector 14 the public safety sector had the lowest rate of hearing impairment at 7 personal protective equipment administrative controls and engineering controls can all work to reduce exposure to noise and chemicals either by providing the worker with protection such as earplugs or by reducing the noise at the source or limiting the time or level of exposure
occupational lung diseases are occupational diseases affecting the respiratory system including occupational asthma black lung disease coalworker s pneumoconiosis chronic obstructive pulmonary disease copd mesothelioma and silicosis infectious lung diseases can also be acquired in an occupational context exposure to substances like flock and silica can cause fibrosing lung disease whereas exposure to carcinogens like asbestos and beryllium can cause lung cancer occupational cases of interstitial lung disease may be misdiagnosed as copd idiopathic pulmonary fibrosis or a myriad of other diseases leading to a delay in identification of the causative agent
occupational stress is stress related to one s job occupational stress often stems from unexpected responsibilities and pressures that do not align with a person s knowledge skills or expectations inhibiting one s ability to cope occupational stress can increase when workers do not feel supported by supervisors or colleagues or feel as if they have little control over work processes
ocean acidification is the ongoing decrease in the ph of the earth s oceans caused by the uptake of carbon dioxide co 2 from the atmosphere seawater is slightly basic meaning ph 7 and the process in question is a shift towards ph neutral conditions rather than a transition to acidic conditions ph 7 ocean alkalinity is not changed by the process or may increase over long time periods due to carbonate dissolution an estimated 30 – 40 of the carbon dioxide from human activity released into the atmosphere dissolves into oceans rivers and lakes to achieve chemical equilibrium some of it reacts with the water to form carbonic acid some of these extra carbonic acid molecules react with a water molecule to give a bicarbonate ion and a hydronium ion thus increasing ocean acidity h ion concentration between 1751 and 1994 surface ocean ph is estimated to have decreased from approximately 8 25 to 8 14 representing an increase of almost 30 in h ion concentration in the world s oceans earth system models project that within the last decade ocean acidity exceeded historical analogs and in combination with other ocean biogeochemical changes could undermine the functioning of marine ecosystems and disrupt the provision of many goods and services associated with the ocean increasing acidity is thought to have a range of potentially harmful consequences for marine organisms such as depressing metabolic rates and immune responses in some organisms and causing coral bleaching by increasing the presence of free hydrogen ions each molecule of carbonic acid that forms in the oceans ultimately results in the conversion of two carbonate ions into bicarbonate ions this net decrease in the amount of carbonate ions available makes it more difficult for marine calcifying organisms such as coral and some plankton to form biogenic calcium carbonate and such structures become vulnerable to dissolution ongoing acidification of the oceans threatens food chains connected with the oceans as members of the interacademy panel 105 science academies have issued a statement on ocean acidification recommending that by 2050 global co 2 emissions be reduced by at least 50 compared to the 1990 level while ongoing ocean acidification is anthropogenic in origin it has occurred previously in earth s history the most notable example is the paleocene eocene thermal maximum petm which occurred approximately 56 million years ago for reasons that are currently uncertain massive amounts of carbon entered the ocean and atmosphere and led to the dissolution of carbonate sediments in all ocean basins ocean acidification has been called the evil twin of global warming and the other co 2 problem
ochronosis is the syndrome caused by the accumulation of homogentisic acid in connective tissues the phenomenon was first described by rudolf virchow in 1865 the condition was named after the yellowish ocher like discoloration of the tissue seen on microscopic examination however macroscopically the affected tissues appear bluish grey because of a light scattering phenomenon known as the tyndall effect the condition is most often associated with alkaptonuria but can occur from exogenous administration of phenol complexes like hydroquinone
the october revolution russian октя́брьская револю́ция tr oktjabrjskaja revoljucija ipa ɐkˈtʲabrʲskəjə rʲɪvɐˈlʲutsɨjə officially known in the soviet literature as the great october socialist revolution russian вели́кая октя́брьская социалисти́ческая револю́ция tr velikaja oktjabrjskaja socialističeskaja revoljucija and commonly referred to as red october the october uprising or the bolshevik revolution was a seizure of state power instrumental in the larger russian revolution of 1917 it took place with an armed insurrection in petrograd traditionally dated to 25 october 1917 by the julian or old style calendar which corresponds to 7 november 1917 in the gregorian or new style calendar it followed and capitalized on the february revolution of the same year which overthrew the tsarist autocracy and resulted in a provisional government after a transfer of power proclaimed by grand duke michael brother of tsar nicolas ii who declined to take power after the tsar stepped down during this time urban workers began to organize into councils russian soviet wherein revolutionaries criticized the provisional government and its actions the october revolution in petrograd overthrew the provisional government and gave the power to the local soviets the bolshevik party was heavily supported by the soviets after the congress of soviets now the governing body had its second session it elected members of the bolsheviks and other leftist groups such as the left socialist revolutionaries to key positions within the new state of affairs this immediately initiated the establishment of the russian socialist federative soviet republic the world s first self proclaimed socialist state the revolution was led by the bolsheviks who used their influence in the petrograd soviet to organize the armed forces bolshevik red guards forces under the military revolutionary committee began the takeover of government buildings on 24 october 1917 o s the following day the winter palace the seat of the provisional government located in petrograd then capital of russia was captured the long awaited constituent assembly elections were held on 12 november 1917 the bolsheviks only won 175 seats in the 715 seat legislative body coming in second behind the socialist revolutionary party which won 370 seats the constituent assembly was to first meet on 28 november 1917 but its convocation was delayed until 5 january 1918 by the bolsheviks on its first and only day in session the body rejected soviet decrees on peace and land and was dissolved the next day by order of the congress of soviets as the revolution was not universally recognized there followed the struggles of the russian civil war 1917 – 22 and the creation of the soviet union in 1922
ocular albinism is a form of albinism which in contrast to oculocutaneous albinism presents primarily in the eyes there are multiple forms of ocular albinism which are clinically similar both known genes are on the x chromosome when the term autosomal recessive ocular albinism aroa is used it usually refers to mild variants of oculocutaneous albinism rather than ocular albinism which is x linked
ocular albinism type 1 oa 1 also called nettleship – falls syndrome is the most common type of ocular albinism with a prevalence rate of 1 50 000 it is an inheritable classical mendelian type x linked recessive disorder wherein the retinal pigment epithelium lacks pigment while hair and skin appear normal since it is an x linked disorder it occurs mostly in males while females are carriers unless they are homozygous about 60 missense and nonsense mutations insertions and deletions have been identified in oa 1 mutations in oa 1 have been linked to defective glycosylation and thus improper intracellular transportation the eponyms of the name nettleship – falls syndrome are edward nettleship and harold francis falls
ocular flutter is an opsoclonic disorder in which the eyes incontinuously saccadically move around the point of fixation in the field of vision
ocular hypertension is a clinical term describing the presence of elevated intraocular pressure in the absence of optic nerve damage or visual field loss for most individuals the normal range of introcular pressure is between 10 mmhg and 21 mmhg elevated intraocular pressure is an important risk factor for glaucoma the ocular hypertension treatment study a large multicentered randomized clinical trial determined that topical ocular hypotensive medication delays or prevents the onset of primary open angle glaucoma accordingly most individuals with consistently elevated intraocular pressures of greater than 21 mmhg particularly if they have other risk factors are treated in an effort to prevent vision loss from glaucoma
ocular ischemic syndrome is the constellation of ocular signs and symptoms secondary to severe chronic arterial hypoperfusion to the eye amaurosis fugax is a form of acute vision loss caused by reduced blood flow to the eye that may be a warning sign of an impending stroke consequently those with transient blurring of vision are advised to urgently seek medical attention for a thorough evaluation of the carotid artery anterior segment ischemic syndrome is a similar ischemic condition of anterior segment usually seen in post surgical cases retinal arterial occlusion leads to rapid death of retinal cells thereby resulting in severe loss of vision
ocular melanosis om also known as ocular melanocytosis or melanosis oculi is a congenital disease of the eye which affects about 1 in every 5000 people and is a risk factor for uveal melanoma in dogs is found almost exclusively in the cairn terrier where until recently it was known as pigmentary glaucoma see also canine glaucoma the disease is caused by an increase of melanocytes in the iris choroid and surrounding structures overproduction of pigment by these cells can block the trabecular meshwork through which fluid drains from the eye the increased fluid in the eye leads to increased pressure which can lead to glaucoma in humans this is sometimes known as pigment dispersion syndrome
ocular myasthenia gravis mg is a disease of the neuromuscular junction resulting in hallmark variability in muscle weakness and fatigability mg is an autoimmune disease where anomalous antibodies are produced against the naturally occurring acetylcholine receptors in voluntary muscles mg may be limited to the muscles of the eye ocular mg leading to abrupt onset of weakness fatigability of the eyelids or eye movement mg may also involve other muscle groups generalized mg
ocular neurosis is the usual cause of eye strain headache that begins abruptly with use of the eyes in which there is a normal ophthalmologic exam icd classification f 45 8 neurosis ocular
ocular rosacea is a manifestation of rosacea that affects the eyes and eyelids signs and symptoms generally consist of redness irritation or burning of the eyes affected individuals may also feel that there is something such as an eyelash in the eye and frequently have redness of the nose and cheeks as well those who suffer from ocular rosacea may be treated with warm compresses artificial tears and washing the area around the eye with warm water including the eyelids to help relieve symptoms additionally oral antibiotics typically doxycycline may be prescribed some people with ocular rosacea feel that dietary restrictions of caffeine spicy foods and alcoholic beverages may reduce or eliminate symptoms
ocular straylight is a phenomenon where parts of the eye scatter light creating glare it is analogous to stray light in other optical systems scattered light reaches the retina but does not contribute to forming a correct image one can observe the effect of straylight by looking at a distant bright light source against a dark background if the source is small it would look like a small bright spot if they eye imaged it perfectly scattering in the eye makes the source appear spread out surrounded by glare the disability glare caused by such a situation has been found to correspond precisely to the effect of true light as a consequence disability glare was subsequently defined by this true light called straylight
the oculocardiac reflex also known as aschner phenomenon aschner reflex or aschner dagnini reflex is a decrease in pulse rate associated with traction applied to extraocular muscles and or compression of the eyeball the reflex is mediated by nerve connections between the ophthalmic branch of the trigeminal cranial nerve via the ciliary ganglion and the vagus nerve of the parasympathetic nervous system nerve fibres from the maxillary and mandibular divisions of the trigeminal nerve have also been documented these afferents synapse with the visceral motor nucleus of the vagus nerve located in the reticular formation of the brain stem the efferent portion is carried by the vagus nerve from the cardiovascular center of the medulla to the heart of which increased stimulation leads to decreased output of the sinoatrial node this reflex is especially sensitive in neonates and children particularly during strabismus correction surgery however this reflex may also occur with adults bradycardia junctional rhythm and asystole all of which may be life threatening can be induced through this reflex
oculocerebrocutaneous syndrome also known as delleman – oorthuys syndrome is a condition characterized by orbital cysts microphthalmia porencephaly agenesis of the corpus callosum and facial skin tags
oculocerebrorenal syndrome also called lowe syndrome is a rare x linked recessive disorder characterized by congenital cataracts hypotonia and areflexia intellectual disability proximal tubular acidosis aminoaciduria phosphaturia and low molecular weight proteinuria glaucoma is present in about 50 of cases lowe syndrome can be considered a cause of fanconi syndrome bicarbonaturia renal tubular acidosis aminoaciduria phosphaturia tubular proteinuria and impaired urine concentrating ability
oculocutaneous albinism oca is a form of albinism involving the eyes oculo the skin cutaneous and according to some definitions the hair overall an estimated 1 in 20 000 people worldwide are born with oculocutaneous albinism oca is caused by mutations in several genes that control the synthesis of melanin within the melanocytes four types of oculocutaneous albinism have been described all caused by a disruption of melanin synthesis and all autosomal recessive disorders
oculocutaneous albinism type i or – type 1 a oca 1 a is an autosomal recessive skin disease associated with albinism this type of albinism is caused when the gene oca 1 does not function properly the location of oca 1 may be written as 11 q 1 4 q 2 1 meaning it is on chromosome 11 long arm somewhere in the range of band 1 sub band 4 and band 2 sub band 1
oculodentodigital syndrome odd syndrome is an extremely rare genetic condition that typically results in small eyes underdeveloped teeth and syndactyly and malformation of the fourth and fifth fingers it has also been called oculo dento digital syndrome oculodentodigital dysplasia oddd and oculodentoosseous dysplasia odod it is considered a kind of ectodermal dysplasia
oculogyric crisis ogc is the name of a dystonic reaction to certain drugs or medical conditions characterized by a prolonged involuntary upward deviation of the eyes the term oculogyric refers to the bilateral elevation of the visual gaze but several other responses are associated with the crisis epilepsy can manifest as oculogyric seizures also called versive seizures
oculomotor apraxia oma also known as cogan ocular motor apraxia or saccadic initiation failure sif is the absence or defect of controlled voluntary and purposeful eye movement it was first described in 1952 by the american ophthalmologist david glendenning cogan people with this condition have difficulty moving their eyes horizontally and moving them quickly the main difficulty is in saccade initiation but there is also impaired cancellation of the vestibulo ocular reflex patients have to turn their head in order to compensate for the lack of eye movement initiation in order to follow an object or see objects in their peripheral vision but they often exceed their target there is controversy regarding whether oma should be considered an apraxia since apraxia is the inability to perform a learned or skilled motor action to command and saccade initiation is neither a learned nor a skilled action
oculomotor nerve palsy or third nerve palsy is an eye condition resulting from damage to the third cranial nerve or a branch thereof as the name suggests the oculomotor nerve supplies the majority of the muscles controlling eye movements thus damage to this nerve will result in the affected individual being unable to move his or her eye normally in addition the nerve also supplies the upper eyelid muscle levator palpebrae superioris and the muscles responsible for pupil constriction sphincter pupillae the limitations of eye movements resulting from the condition are generally so severe that the affected individual is unable to maintain normal alignment of their eyes when looking straight ahead leading to strabismus and as a consequence double vision diplopia it is also known as oculomotor neuropathy
oculomucocutaneous syndrome is characterized by keratoconjunctivitis sicca and by scarring fibrosis metaplasia and shrinkage of the conjunctiva it is a drug side effect observed in practolol and eperisone it is speculated that antibodies against drug metabolites cause the syndrome
oculopharyngeal muscular dystrophy opmd is a rare form of muscular dystrophy with symptoms generally starting when an individual is 40 to 50 years old it can be autosomal dominant neuromuscular disease or autosomal recessive the most common inheritance of opmd is autosomal dominant which means only one copy of the mutated gene needs to be present in each cell children of an affected parent have a 50 chance of inheriting the mutant gene autosomal dominant inheritance is the most common form of inheritance less commonly opmd can be inherited in an autosomal recessive pattern which means that two copies of the mutated gene need to be present in each cell both parents need to be carriers of the mutated gene and usually show no signs or symptoms the pabpn 1 mutation contains a gcg trinucleotide repeat at the 5 end of the coding region and expansion of this repeat which then leads to autosomal dominant oculopharyngeal muscular dystrophy opmd disease
an odontogenic infection is an infection that originates within a tooth or in the closely surrounding tissues the term is derived from odonto from ancient greek odous tooth and genic from greek genos birth odontogenic infections may remain localized to the region where they started or spread into adjacent or distant areas it is estimated that 90 95 of all orofacial infections originate from the teeth or their supporting structures furthermore about 70 of odontogenic infections occur as periapical inflammation i e acute periapical periodontitis or a periapical abscess the next most common form of odontogenic infection is the periodontal abscess
the odontogenic myxoma is an uncommon benign odontogenic tumor arising from embryonic connective tissue associated with tooth formation as a myxoma this tumor consists mainly of spindle shaped cells and scattered collagen fibers distributed through a loose mucoid material
an odontogenic tumor is a neoplasm of the cells or tissues that initiate odontogenic processes examples include adenomatoid odontogenic tumor ameloblastoma a type of odontogenic tumor involving ameloblasts calcifying epithelial odontogenic tumor keratocystic odontogenic tumor odontogenic myxoma odontoma
an odontoma also termed odontome is a benign tumour of odontogenic origin i e linked to tooth development specifically it is a dental hamartoma meaning that it is composed of normal dental tissue that has grown in an irregular way the average age of people found with an odontoma is 14 the condition is frequently associated with one or more unerupted teeth though most cases are found impacted within the jaw there are instances where odontomas have erupted into the oral cavity
odontoma dysphagia syndrome bader syndrome is a rare syndrome 10 cases reported to date first described in 1967 the cause is not known but it is suspected to be genetic in origin
odonto – tricho ungual – digital – palmar syndrome is an autosomal dominant skin condition with salient clinical features of natal teeth trichodystrophy prominent interdigital folds simian like hands with transverse palmar creases and ungual digital dystrophy
odynorgasmia or painful ejaculation is a physical syndrome described by pain or burning sensation of the urethra or perineum during or following ejaculation causes include infections associated with urethritis prostatitis epididymitis as well as use of anti depressants
oesophagogastric junctional adenocarcinoma is a cancer of the lower part of the oesophagus often linked to a barrett s oesophagus the incidence of oesophagogastric junctional adenocarcinoma is rising rapidly in western countries in contrast to the declining frequency of distal gastric adenocarcinoma treatment options for adenocarcinomas involving the oesophagogastric junction are limited and the overall prognosis is extremely poor
an off by one error oboe also commonly known as an obob off by one bug or that extra inch you didn t really want is a logic error involving the discrete equivalent of a boundary condition it often occurs in computer programming when an iterative loop iterates one time too many or too few this problem could arise when a programmer makes mistakes such as using is less than or equal to where is less than should have been used in a comparison or fails to take into account that a sequence starts at zero rather than one as with array indices in many languages this can also occur in a mathematical context
in basketball statistics offensive efficiency rating oer is the average amount of points scored by a basketball player per shot taken this includes missed field goals as well as free throws
the official victim enhancement is a 3 or 6 level increase under the u s sentencing guidelines that applies when a person knowingly commits a crime against a government official and is motivated by that person s status the provision also states if the official victim is an exceptionally high level official such as the president or the vice president of the united states an upward departure may be warranted due to the potential disruption of the governmental function there are many crimes against federal officials that do not require as an element of the offense that the offender know the status of the victim but this enhancement does the victimization of the government official need not be the offense of conviction it is possible for instance for the defendant to be convicted of robbing a bank and to get the official victim enhancement for harming a uniformed police officer as he escapes the assault on the officer is considered relevant conduct in cases involving threats against the president of the united states courts have applied the official victim enhancement rejecting arguments that in order for it to apply the president actually had been harmed or knew of the existence of the defendant s letter there has been a circuit split in the federal appellate courts as to whether crimes against local government officials qualify for the official victim enhancement 0 1 of federal cases involve the official victim enhancement the term official victim also is used in victimology to refer to a four stage process in which a person progresses from being a harmed injured or suffering person s to perceiving or defining oneself as a victim to claiming the victim role from social control agents or significant others and then to social control agents recognition of the role claim — becoming an official victim and receiving compensatory and supportive actions by social control agents
an offstage brass and percussion part is a sound effect used in classical music which is created by having one or more trumpet players also called an offstage trumpet call horn players or percussionists from a symphony orchestra or opera orchestra play a note melody or rhythm from behind the stage this creates a distant muted effect which composers use to suggest celestial voices melancholy or nostalgia or to create a haunting effect
ogden syndrome also known as n terminal acetyltransferase deficiency natd is an x linked disorder of infancy comprising a distinct combination of distinctive craniofacial features producing an aged appearance growth failure hypotonia global developmental delays cryptorchidism and acquired cardiac arrhythmias the first family was identified in ogden utah with five affected boys in two generations of family members a mutation was identified as a c 109 t c p ser 37 pro variant in naa 10 a gene encoding the protein naa 10 catalytic subunit of the major human n terminal acetyltransferase nata this same mutation was identified in a second unrelated family with three affected boys in two generations this x linked malformation and infantile lethality syndrome has provisionally been named ogden syndrome in honor of the hometown where the first family resides
ogilvie syndrome is the acute dilation of the colon in the absence of any mechanical obstruction in severely ill patients colonic pseudo obstruction is characterized by massive dilatation of the cecum diameter 10 cm and right colon on abdominal x ray it is a type of megacolon sometimes referred to as acute megacolon to distinguish it from toxic megacolon the condition carries the name of the british surgeon sir william heneage ogilvie 1887 – 1971 who first reported it in 1948
oguchi disease also called congenital stationary night blindness oguchi type 1 or oguchi disease 1 is an autosomal recessive form of congenital stationary night blindness associated with fundus discoloration and abnormally slow dark adaptation
ohtahara syndrome os also known as early infantile epileptic encephalopathy with burst suppression eiee is a progressive epileptic encephalopathy the syndrome is outwardly characterized by tonic spasms and partial seizures and receives its more elaborate name from the pattern of burst activity on an electroencephalogram eeg it is an extremely debilitating progressive neurological disorder involving intractable seizures and severe mental retardation no single cause has been identified although in many cases structural brain damage is present
oil acne is an occupational skin condition caused by exposure to oils used in industry
oil depletion is the decline in oil production of a well oil field or geographic area the hubbert peak theory makes predictions of production rates based on prior discovery rates and anticipated production rates hubbert curves predict that the production curves of non renewing resources approximate a bell curve thus according to this theory when the peak of production is passed production rates enter an irreversible decline the united states energy information administration predicted in 2006 that world consumption of oil will increase to 98 3 million barrels per day 15 630 000 m 3 d mbd in 2015 and 118 million barrels per day in 2030 with 2009 world oil consumption at 84 4 mbd reaching the projected 2015 level of consumption would represent an average annual increase between 2009 and 2015 of 2 7 per year
oil reserves are the amount of technically and economically recoverable oil reserves may be for a well for a reservoir for a field for a nation or for the world different classifications of reserves are related to their degree of certainty the total estimated amount of oil in an oil reservoir including both producible and non producible oil is called oil in place however because of reservoir characteristics and limitations in petroleum extraction technologies only a fraction of this oil can be brought to the surface and it is only this producible fraction that is considered to be reserves the ratio of reserves to the total amount of oil in a particular reservoir is called the recovery factor determining a recovery factor for a given field depends on several features of the operation including method of oil recovery used and technological developments based on data from opec at the beginning of 2013 the highest proved oil reserves including non conventional oil deposits are in venezuela 20 of global reserves saudi arabia 18 of global reserves canada 13 of global reserves and iran 9 because the geology of the subsurface cannot be examined directly indirect techniques must be used to estimate the size and recoverability of the resource while new technologies have increased the accuracy of these techniques significant uncertainties still remain in general most early estimates of the reserves of an oil field are conservative and tend to grow with time this phenomenon is called reserves growth many oil producing nations do not reveal their reservoir engineering field data and instead provide unaudited claims for their oil reserves the numbers disclosed by some national governments are suspected of being manipulated for political reasons
oil toxicity or oil intoxication is a wildlife disease resulting from the accidental exposure of animals to oil major sources of such oil in the environment include accidental oil spills from off shore sites oil tankers pipelines and other facilities that store and process oil wildlife exposure to oil can result in both external and internal damage oil intoxication has the greatest impact on bird species aquatic mammals and other aquatic organisms affected wildlife can usually be identified via visual inspection and can be treated if found early on
in information retrieval okapi bm 25 bm stands for best matching is a ranking function used by search engines to rank matching documents according to their relevance to a given search query it is based on the probabilistic retrieval framework developed in the 1970 s and 1980 s by stephen e robertson karen spärck jones and others the name of the actual ranking function is bm 25 to set the right context however it usually referred to as okapi bm 25 since the okapi information retrieval system implemented at london s city university in the 1980 s and 1990 s was the first system to implement this function bm 25 and its newer variants e g bm 25 f a version of bm 25 that can take document structure and anchor text into account represent state of the art tf idf like retrieval functions used in document retrieval such as web search
old country roses is a famous pattern of bone china made by english tableware creator royal albert a brand of royal doulton it is said to be the best selling pattern of bone china in the world since is creation in 1962
the old nassau reaction or halloween reaction is a chemical clock reaction in which a clear solution turns orange and then black this reaction was discovered by two undergraduate students at princeton university researching the inhibition of the iodine clock reaction or landolt reaction by hg 2 resulting in the formation of orange hgi 2 orange and black are the school colors of princeton university and old nassau is a nickname for princeton named for its historic administration building nassau hall
olecranon bursitis also informally known as smiles elbow elbow bump student s elbow popeye elbow baker s elbow or gamer s elbow is a condition characterized by pain redness and swelling around the olecranon caused by inflammation of the elbow s bursa this bursa is located just over the extensor aspect of the extreme proximal end of the ulna in common with other bursae it is impalpable and contains only a very small amount of fluid in its normal state and fulfills the function of facilitating the joint s movement by enabling anatomical structures to glide more easily over each other
olecranon fracture is a fracture of the bony portion of the elbow the injury is fairly common and often occurs following a fall or direct trauma to the elbow the olecranon is the proximal extremity of the ulna which is articulated with the humerus bone and constitutes a part of the elbow articulation its subcutaneous location makes it vulnerable to direct trauma powerful pull of the triceps muscle can also cause avulsion fractures
olefin metathesis is an organic reaction that entails the redistribution of fragments of alkenes olefins by the scission and regeneration of carbon carbon double bonds catalysts for this reaction have evolved rapidly for the past few decades because of the relative simplicity of olefin metathesis it often creates fewer undesired by products and hazardous wastes than alternative organic reactions for their elucidation of the reaction mechanism and their discovery of a variety of highly efficient and selective catalysts yves chauvin robert h grubbs and richard r schrock were collectively awarded the 2005 nobel prize in chemistry
olfactory reference syndrome ors is a mental disorder in which there is a persistent false belief about and preoccupation with emitting abnormal body odor s which are foul and offensive to other individuals persons with ors often misinterpret others behaviors e g sniffing touching nose or opening a window as being referential to a body odor which in reality is non existent and cannot be detected by other people this disorder is often accompanied by shame embarrassment significant distress avoidance behavior social phobia and social isolation the term olfactory reference syndrome comes from olfactory pertaining to the sense of smell reference because of the belief that the behavior of others is referential to a supposed odor syndrome because it is a recognizable set of features that occur together
oligoastrocytomas are a subset of brain tumors that present with an appearance of mixed glial cell origin astrocytoma and oligodendroglioma these types of glial cells that become cancerous are involved with insulating and regulating the activity of neuron cells in the central nervous system often called a mixed glioma about 2 3 of all reported brain tumors are diagnosed as oligoastrocytoma the median age of diagnosis is 42 5 oligoastrocytomas like astrocytomas and oligodendrogliomas can be divided into low grade and anaplastic variant the latter characterized by high cellularity conspicuous cytologic atypism mitotic activity and in some cases microvascular proliferation and necrosis however lower grades can have less aggressive biology these are largely supratentorial tumors of adulthood that favor the frontal and temporal lobes
oligodactyly from the ancient greek oligos meaning few and δάκτυλος daktylos meaning finger is the presence of fewer than five fingers or toes on a hand or foot it is quite often incorrectly called hypodactyly but the greek prefixes hypo and hyper are used for continuous scales e g in hypoglycaemia and hypercholesterolemia this as opposed to discrete or countable scales where oligo and poly should be used e g in oligarchy and polygamy oligodactyly is therefore the opposite of polydactyly very rare this medical condition usually has a genetic or familial etiology oligodactyly is sometimes a sign or symptom of several syndromes including poland syndrome and weyer ulnar ray syndrome it is a type of dysmelia ectrodactyly is an extreme instance of oligodactyly involving the absence of one or more central digits of the hand or foot and is also known as split hand split foot malformation shfm the hands and feet of people with ectrodactyly are often described as claw like and may include only the thumb and one finger usually either the little finger ring finger or a syndactyly of the two with similar abnormalities of the feet people with oligodactyly often have full use of the remaining digits and adapt well to their condition they are not greatly hindered in their daily activities if at all even those with the most extreme forms are known to engage in tasks that require fine control such as writing and bootmaking as well as working as a cab driver vadoma people of zimbabwe have a high frequency of oligodactyly
oligodendrocyte progenitor cells opcs also known as oligodendrocyte precursor cells ng 2 glia or polydendrocytes are a subtype of glial cells in the central nervous system they are precursors to oligodendrocytes and may also be able to differentiate into neurons and astrocytes differentiated oligodendrocytes support axons and provide electrical insulation in the form of a myelin sheath enabling faster action potential propagation and high fidelity transmission without a need for an increase in axonal diameter the loss or lack of opcs and consequent lack of differentiated oligodendrocytes is associated with a loss of myelination and subsequent impairment of neurological functions
oligodendrogliomas are a type of glioma that are believed to originate from the oligodendrocytes of the brain or from a glial precursor cell they occur primarily in adults 9 4 of all primary brain and central nervous system tumors but are also found in children 4 of all primary brain tumors the average age at diagnosis is 35 years
oligohydramnios is a condition in pregnancy characterized by a deficiency of amniotic fluid it is the opposite of polyhydramnios
oligomenorrhea or oligomenorrhoea is infrequent or in occasional usage very light menstruation more strictly it is menstrual periods occurring at intervals of greater than 35 days with only four to nine periods in a year also menstrual periods should have been regularly established previously before the development of infrequent flow the duration of such events may vary
terms oligospermia and oligozoospermia refer to semen with a low concentration of sperm and is a common finding in male infertility often semen with a decreased sperm concentration may also show significant abnormalities in sperm morphology and motility technically oligoasthenoteratozoospermia there has been interest in replacing the descriptive terms used in semen analysis with more quantitative information
olive skin is a human skin color spectrum it is often associated with pigmentation in the type iv to type v range of the fitzpatrick scale it generally refers to light or moderate brown brownish or tannish skin and it is often described as having yellowish greenish or golden undertones however lighter olive skin on the lower end of the type iv coloration range may be less brownish and can in fact become somewhat pale if it receives too little sun exposure though lighter olive skin still tans easier than fair skin and generally still retains notable yellow or greenish undertones
oliver – mcfarlane syndrome is a condition characterized by hypertrichosis of the eyebrows and eyelashes
olivopontocerebellar atrophy opca is the degeneration of neurons in specific areas of the brain – the cerebellum pons and inferior olives opca is present in several neurodegenerative syndromes including inherited and non inherited forms of ataxia such as the hereditary spinocerebellar ataxia known as machado – joseph disease and multiple system atrophy msa with which it is primarily associated opca may also be found in the brains of individuals with prion disorders and inherited metabolic diseases the characteristic areas of brain damage that indicate opca can be seen by imaging the brain using ct scans or mri studies the term was originally coined by joseph jules dejerine and andré thomas
ollier disease is a rare nonhereditary sporadic disorder where intraosseous benign cartilaginous tumors enchondroma develop close to growth plate cartilage prevalence is estimated at around 1 in 100 000
omasitis is an inflammation of the omasum the third compartment of the stomach in ruminants it usually accompanies rumenitis and is often caused by infection with fusobacterium necrophorum
an omen also called portent or presage is a phenomenon that is believed to foretell the future often signifying the advent of change people in the ancient times believed that omens lie with a divine message from their gods these omens include natural phenomena for example an eclipse abnormal births of animals and humans and behavior of the sacrificial lamb on its way to the slaughter they had specialists the diviners to interpret these omens they would also use an artificial method for example a clay model of a sheep liver to communicate with their gods in times of crisis they would expect a binary answer either yes or no answer favorable or unfavorable they did these to predict what would happen in the future and to take action to avoid disaster though the word omen is usually devoid of reference to the change s nature hence being possibly either good or bad the term is more often used in a foreboding sense as with the word ominous the origin of the word is unknown although it may be connected with the latin word audire meaning to hear
omenn syndrome is an autosomal recessive severe combined immunodeficiency associated with hypomorphic missense mutations in immunologically relevant genes of t cells and b cells as recombination activating genes rag 1 and rag 2 il 7 receptor α gene il 7 rα dclre 1 c artemis rmrp chh dna ligase iv common gamma chain whn foxn 1 zap 70 and complete digeorge anomaly digeorge syndrome charge
omental infarction or omental torsion is an acute vascular disorder which compromises tissue of the greater omentum — the largest peritoneal fold in the abdomen
an omnibus hearing is a pretrial hearing it is usually soon after a defendant s arraignment the main purpose of the hearing is to determine the evidence including testimony and evidence seized at the time of arrest the prosecutor and the defendant s counsel attend the hearing to discuss pretrial matters pertaining to the case
omophagia or omophagy from greek ωμός raw is the eating of raw flesh the term is of importance in the context of the cult worship of dionysus omophagia is a large element of dionysiac myth in fact one of dionysus epithets is omophagos raw eater omophagia may have been a symbol of the triumph of wild nature over civilization and a symbol of the breaking down of boundaries between nature and civilization it might also have been symbolic that the worshippers were internalizing dionysus ’ wilder traits and his association with brute nature in a sort of “ communion ” with the god mythology sometimes depicts maenads dionysus female worshippers eating raw meat as part of their worship however there is little solid evidence that historical maenads consumed raw meat the dionysiac diet of raw meat may be more properly attributed to dionysus himself rather than his followers — he received sacrifices of raw meat and was believed to consume them but his followers did not share in the consumption
omphalitis of newborn is the medical term for inflammation of the umbilical cord stump in the neonatal newborn period most commonly attributed to a bacterial infection typically immediately after an infant is born the umbilical cord is cut with a small remnant often referred to as the stump left behind normally the stump separates from the skin within 3 – 45 days after birth a small amount of pus like material is commonly seen at the base of the stump and can be controlled by keeping the stump open to air to dry certain bacteria can grow and infect the stump during this process and as a result significant redness and swelling may develop and in some cases the infection can then spread through the umbilical vessels to the rest of the body while currently an uncommon anatomical location for infection in the newborn in the united states it has caused significant morbidity and mortality both historically and in areas where health care is less readily available in general when this type of infection is suspected or diagnosed antibiotic treatment is given and in cases of serious complications surgical management may be appropriate
an omphalocele british english omphalocoele is a rare abdominal wall defect in which the intestines liver and occasionally other organs remain outside of the abdomen in a sac because of a defect in the development of the muscles of the abdominal wall exomphalos omphalocele occurs in 1 4 000 births and is associated with a high rate of mortality 25 and severe malformations such as cardiac anomalies 50 and neural tube defect 40 approximately 15 of live born infants with omphalocele have chromosomal abnormalities about 30 of infants with an omphalocele have other congenital abnormalities
omsk hemorrhagic fever is a viral hemorrhagic fever caused by a flavivirus it is found in siberia it is named for an outbreak in omsk
once upon a girl is a 1976 x rated live action animated film written produced and directed by don jurwich it was animated by a group of animators who had worked for disney according to the director in an interview included with the dvd release the film was released in some theaters and did not lose money
onchocerciasis also known as river blindness and robles disease is a disease caused by infection with the parasitic worm onchocerca volvulus symptoms include severe itching bumps under the skin and blindness it is the second most common cause of blindness due to infection after trachoma the parasite worm is spread by the bites of a black fly of the simulium type usually many bites are required before infection occurs these flies live near rivers hence the name of the disease once inside a person the worms create larvae that make their way out to the skin here they can infect the next black fly that bites the person there are a number of ways to make the diagnosis including placing a biopsy of the skin in normal saline and watching for the larva to come out looking in the eye for larvae and looking within the bumps under the skin for adult worms a vaccine against the disease does not exist prevention is by avoiding being bitten by flies this may include the use of insect repellent and proper clothing other efforts include those to decrease the fly population by spraying insecticides efforts to eradicate the disease by treating entire groups of people twice a year is ongoing in a number of areas of the world treatment of those infected is with the medication ivermectin every six to twelve months this treatment kills the larva but not the adult worms the medication doxycycline which kills an associated bacterium called wolbachia appears to weaken the worms and is recommended by some as well removal of the lumps under the skin by surgery may also be done about 17 to 25 million people are infected with river blindness with approximately 0 8 million having some amount of loss of vision most infections occur in sub saharan africa although cases have also been reported in yemen and isolated areas of central and south america in 1915 the physician rodolfo robles first linked the worm to eye disease it is listed by the world health organization as a neglected tropical disease
an oncocytoma is a tumor made up of oncocytes epithelial cells characterized by an excessive amount of mitochondria resulting in an abundant acidophilic granular cytoplasm the cells and the tumor that they compose are often benign but sometimes may be premalignant or malignant
oncofertility is a subfield that bridges oncology and reproductive research to explore and expand options for the reproductive future of cancer survivors it was coined in 2006 by dr teresa k woodruff at the oncofertility consortium cancer treatments such as chemotherapy radiation and surgery may destroy a person s ability to have children later in life and oncofertility research focuses on increasing fertility preservation options with 10 of cancer patients being younger than age 40 this issue affects more than 135 000 people in the united states each year as cancer survivorship increases the preservation of fertility in women men and children becomes a critically important topic to patients and their families the ability to easily preserve fertility prior to cancer treatment can provide hope at the time of diagnosis for families later in life oncofertility also incorporates reproductive issues after cancer treatment such as family planning complex contraception hormonal management throughout survivorship surrogacy and adoption
tumor induced osteomalacia also known as oncogenic hypophosphatemic osteomalacia or oncogenic osteomalacia is an uncommon disorder resulting in increased renal phosphate excretion hypophosphatemia and osteomalacia
one repetition maximum one rep maximum or 1 rm in weight training is the maximum amount of force that can be generated in one maximal contraction one repetition maximum can be used for determining an individual s maximum strength and is the method for determining the winner in events such as powerlifting and weightlifting competitions one repetition maximum can also be used as an upper limit in order to determine the desired load for an exercise as a percentage of the 1 rm
in cryptography a one way compression function is a function that transforms two fixed length inputs into a fixed length output the transformation is one way meaning that it is difficult given a particular output to compute inputs which compress to that output one way compression functions are not related to data compression which by definition can be inverted exactly lossless compression or approximately lossy compression to the original data one way compression functions are for instance used in the merkle – damgård construction inside cryptographic hash functions one way compression functions are often built from block ciphers some methods to turn any normal block cipher into a one way compression function are davies – meyer matyas – meyer – oseas miyaguchi – preneel single block length compression functions and mdc 2 meyer – schilling mdc 4 hirose double block length compression functions these methods are described in detail further down mdc 2 is also the name of a hash function patented by ibm
in computer science a one way function is a function that is easy to compute on every input but hard to invert given the image of a random input here easy and hard are to be understood in the sense of computational complexity theory specifically the theory of polynomial time problems not being one to one is not considered sufficient of a function for it to be called one way see theoretical definition below the existence of such one way functions is still an open conjecture in fact their existence would prove that the complexity classes p and np are not equal thus resolving the foremost unsolved question of theoretical computer science the converse is not known to be true i e the existence of a proof that p and np are not equal would not directly imply the existence of one way functions in applied contexts the terms easy and hard are usually interpreted relative to some specific computing entity typically cheap enough for the legitimate users and prohibitively expensive for any malicious agents one way functions in this sense are fundamental tools for cryptography personal identification authentication and other data security applications while the existence of one way functions in this sense is also an open conjecture there are several candidates that have withstood decades of intense scrutiny some of them are essential ingredients of most telecommunications e commerce and e banking systems around the world
one hour by the concrete lake is pain of salvation s second studio album it is a concept album focusing on the issues of nuclear power and waste displacement of indigenous peoples the firearm industry and human discovery
the one and a half syndrome is a rare weakness in eye movement affecting both eyes in which one cannot move laterally at all and the other can move in only one lateral direction inward or outward more formally it is characterized by a conjugate horizontal gaze palsy in one direction and an internuclear ophthalmoplegia in the other the most common manifestation of this unusual syndrome is limitation of horizontal eye movement to abduction moving away from the midline of one eye e g right eye in the diagram on the right with no horizontal movement of the other eye e g left eye in the diagram on the right nystagmus is also present when the eye on the opposite side of the lesion is abducted convergence is classically spared as cranial nerve iii oculomotor nerve and its nucleus is spared bilaterally
ong keo องค์แก้ว led austroasiatic speaking minorities formerly called mon khmer in what in thailand was called the holy man s rebellion where it was a widespread but short lived cause against french and lao forces however ong keo continued the struggle until his murder in 1910 after his death fighting still continued under his successor ong kommandam until at least 1937 local legend holds that ong keo survived the murder attempt and lived until the early 1970 s
onlap or overlap is the geologic phenomenon of successively wedge shaped younger rock strata extending progressively further across an erosion surface cut in older rocks it is generally associated with a marine transgression it is a more general term than overstep in which the younger beds overlap onto successively older beds the opposite is offlap
ontario minamata disease is a neurological syndrome caused by severe mercury poisoning it occurred in the canadian province of ontario in 1970 and severely affected two first nation communities in northwestern ontario following consumption of local fish contaminated with mercury and one first nation in southern ontario due to illegal disposal of industrial chemical waste the disease was named after the infamous case of severe mercury poisoning in the fishing community of minamata japan which became known as minamata disease because it devastated only the residents of the community
the ontario government debt is the amount of money the government of ontario borrowed from the general public institutional investors and from public sector bodies as of september 30 2013 the ontario government s total debt stood at cdn 288 10 billion the interest on the debt was cdn 10 3 billion for the 2012 2013 ontario budget at an effective interest rate of 4 it represented 8 4 of the total budgetary expenses and is the fastest rising cost for the ontario government the debt to gdp ratio in 2015 was 39 4 the highest in ontario s history
onychauxis presents with thickened nails without deformity and this simple thickening may be the result of trauma acromegaly darier s disease psoriasis or pityriasis rubra pilaris or in some cases hereditary
onychoatrophy is a faulty underdevelopment of the nail that may be congenital or acquired in which the nail is thinned and smaller
onychogryphosis also known as onychogryposis or ram s horn nails is a hypertrophy that may produce nails resembling claws or a ram s horn
onycholysis refers to the detachment of the nail from the nail bed usually starting at the tip and or sides on the hands it is said to occur particularly on the ring finger but can occur on any of the fingernails it may also happen to toenails onycholysis can occur in many conditions including psoriasis in thyrotoxicosis it is thought to be due to sympathetic overactivity it may also be seen in infections or trauma
onychomadesis is a periodic idiopathic shedding of the nails beginning at the proximal end possibly caused by the temporary arrest of the function of the nail matrix one cause in children is hand foot and mouth disease this generally resolves without complication onychomadesis can also occur if the nail is damaged or suffers a loss of blood supply i e due to a bruise the nailbed turns black and the nail drops off shortly afterwards it takes around 6 to 12 months to regrow
onychomatricoma is a cutaneous condition characterized by a distinctive tumor of the nail matrix this nail disease can mimic many nail problems and should be examined and biopsied by a dermatologist in particular a main concern is the malignant and destructive potential that may exist
onychomycosis is a fungal infection of the nail it is the most common disease of the nails and constitutes about half of all nail abnormalities this condition may affect toenails or fingernails but toenail infections are particularly common it occurs in about 10 percent of the adult population
onychophosis is a localized or diffuse hyperkeratotic tissue that develops on the lateral or proximal nailfolds within the space between the nailfolds and the nail plate and is a common finding in the elderly onychophosis may involve the subungual area as a direct result of repeated minor trauma and most frequently affects the first and fifth toes
onychorrhexis from the words in greek onycho nail rhexis bursting also known as brittle nails is a brittleness with breakage of finger or toenails that may result from excessive strong soap and water exposure nail polish remover hypothyroidism anemia anorexia nervosa or bulimia or after oral retinoid therapy onychorrhexis affects up to 20 of the population
onychotillomania is a compulsive neurosis in which a person picks constantly at the nails or tries to tear them off it is not the same as onychophagia where the nails are bitten or chewed or dermatillomania where skin is bitten or scratched it is commonly associated with psychiatric disorders such as depressive neurosis delusions of infestation and hypochondriasis it was named by professor jan alkiewicz a polish dermatologist the constant destruction of the nail bed leads to onychodystrophy paronychia and darkening of the nail some cases have been treated successfully with antipsychotics
oophoritis is an inflammation of the ovaries it is often seen in combination with salpingitis inflammation of the fallopian tubes it may develop in response to infection
open circuit voltage abbreviated as ocv or voc is the difference of electrical potential between two terminals of a device when disconnected from any circuit there is no external load connected no external electric current flows between the terminals it is sometimes given the symbol voc in network analysis this voltage is also known as the thévenin voltage the open circuit voltages of batteries and solar cells are often quoted under particular conditions state of charge illumination temperature etc open circuit potential is important since the metal with the low open potential will dissolve faster in the electrolyte than the metal with high open circuit potential the potential difference mentioned in the batteries and cells is usually the open circuit voltage open circuit voltage is known as the emf which is the maximum potential difference when there is no current and the circuit is not closed to calculate open circuit voltage one can use a method similar to the one below consider the circuit given circuit if we want to find the open circuit voltage across 5 ω resistor first disconnect it from the circuit modified circuit find the equivalent resistance in loop 1 and hence find the current in the loop use ohm ’ s law to find the potential drop across the resistance c the resistor b does not affect the open circuit voltage since no current is flowing through it there is no potential drop across it so we can easily ignore it therefore the potential drop across the resistance c is vl this is just an example many other ways can be used
in theoretical computer science and operations research the open shop scheduling problem ossp is a scheduling problem in which a given set of jobs must each be processed for given amounts of time at each of a given set of workstations in an arbitrary order and the goal is to determine the time at which each job is to be processed at each workstation the problem was first studied by teofilo f gonzalez and sartaj sahni in 1976
opensimplex noise is an n dimensional gradient noise function that was developed in order to overcome the patent related issues surrounding simplex noise while continuing to also avoid the visually significant directional artifacts characteristic of perlin noise the algorithm shares numerous similarities with simplex noise but has two primary differences whereas simplex noise starts with a hypercubic honeycomb and squashes it down the main diagonal in order to form its grid structure opensimplex noise instead swaps the skew and inverse skew factors and uses a stretched hypercubic honeycomb the stretched hypercubic honeycomb becomes a simplectic honeycomb after subdivision this means that 2 d simplex and 2 d opensimplex both use different orientations of the triangular tiling but whereas 3 d simplex uses the tetragonal disphenoid honeycomb 3 d opensimplex uses the tetrahedral octahedral honeycomb opensimplex noise uses a larger kernel size than simplex noise the result is a smoother appearance at the cost of performance as additional vertices need to be determined and factored into each evaluation
in topology an open map is a function between two topological spaces which maps open sets to open sets that is a function f x → y is open if for any open set u in x the image f u is open in y likewise a closed map is a function which maps closed sets to closed sets a map may be open closed both or neither in particular an open map need not be closed and vice versa open and closed maps are not necessarily continuous further continuity is independent of openness and closedness in the general case and a continuous function may have one both or neither property this fact remains true even if one restricts oneself to metric spaces although their definitions seem more natural open and closed maps are much less important than continuous maps recall that by definition a function f x → y is continuous if the preimage of every open set of y is open in x equivalently if the preimage of every closed set of y is closed in x early study of open maps was pioneered by simion stoilow and gordon thomas whyburn
open collaboration is a pattern of collaboration innovation and production it was observed prominently in open source software but can also be found in many other instances such as in internet forums mailing lists and online communities open collaboration is also thought to be the operating principle underlining a gamut of diverse ventures including bitcoin tedx and wikipedia in a 2009 paper riehle et al define open collaboration as collaboration based on three principles of egalitarianism meritocracy and self organization in a 2013 paper levine and prietula define open collaboration as any system of innovation or production that relies on goal oriented yet loosely coordinated participants who interact to create a product or service of economic value which they make available to contributors and noncontributors alike this definition captures multiple instances all joined by similar principles for example all of the elements — goods of economic value open access to contribute and consume interaction and exchange purposeful yet loosely coordinated work — are present in an open source software project in wikipedia or in a user forum or community they can also be present in a commercial website that is based on user generated content in all of these instances of open collaboration anyone can contribute and anyone can freely partake in the fruits of sharing which are produced by interacting participants who are loosely coordinated open collaboration is the principle underlying peer production mass collaboration and wikinomics it was observed initially in open source software but can also be found in many other instances such as in internet forums mailing lists internet communities and many instances of open content such as creative commons it also explains some instances of crowdsourcing collaborative consumption and open innovation an annual conference dedicated to the research and practice of open collaboration is the international symposium on wikis and open collaboration opensym formerly wikisym as per its website the group defines open collaboration as collaboration that is egalitarian everyone can join no principled or artificial barriers to participation exist meritocratic decisions and status are merit based rather than imposed and self organizing processes adapt to people rather than people adapt to pre defined processes
in business open communication or open access to communication resources is the ability of anyone on equal conditions with a transparent relation between cost and pricing to get access to and share communication resources on one level to provide value added services on another level in a layered communication system architecture simply put open access plans are to deregulate oligarchy of telecom operators in a bid to give consumers more choices for equipment services and service vendors or carriers it will also provide some breathing room for the controversial net neutrality that has been the central issue between mobile carriers like at t verizon and sprint nextel and web media moguls like ebay amazon com and google
in science and mathematics an open problem or an open question is a known problem which can be accurately stated and which is assumed to have an objective and verifiable solution but which has not yet been solved no solution for it is known in the history of science some of these supposed open problems were solved by means of showing that they were not after all well defined many open problems in mathematics are in fact concerned with the question whether a certain definition is or is not consistent two notable examples in mathematics that have been solved and closed by researchers in the late twentieth century are fermat s last theorem and the four color theorem an important open mathematics problem solved in the early 21 st century is the poincaré conjecture important open problems exist in all scientific fields for example one of the most important open problems in biochemistry is the protein structure prediction problem – how to predict a protein s structure from its sequence
operability is the ability to keep an equipment a system or a whole industrial installation in a safe and reliable functioning condition according to pre defined operational requirements in a computing systems environment with multiple systems this includes the ability of products systems and business processes to work together to accomplish a common task such as finding and returning availability of inventory for flight in the gas turbine engine business engine operability is the ability of the engine to operate without compressor stall or surge combustor flame out or other power loss operability engineers work in the fields of engine and compressor modeling control and test to ensure the engine meets its ignition starting acceleration deceleration and over speed requirements under the most extreme operating conditions operability is considered one of the ilities and is closely related to reliability supportability and maintainability operability also refers to whether or not a surgical operation can be performed to treat a patient with a reasonable degree of safety and chance of success
operation kipion is a long standing maritime presence in the persian gulf and indian ocean to promote enduring peace and stability in the region by the united kingdom
in physics an operator is a function over a space of physical states to another space of physical states the simplest example of the utility of operators is the study of symmetry which makes the concept of a group useful in this context because of this they are a very useful tool in classical mechanics operators are even more important in quantum mechanics where they form an intrinsic part of the formulation of the theory
ophiasis is a form of alopecia areata characterized by the loss of hair in the shape of a wave at the circumference of the head it gets its name from ophis which is the greek word for snake because of the apparent similarity to a snake shape and the pattern of hair loss the term sisaipho is used to characterize the inverse pattern sisaipho is the reverse spelling of ophiasis it is also called ophiasis inversus ophiasis has poor prognostic significance
ophthalmia also called ophthalmitis is inflammation of the eye it is a medical sign which may be indicative of various conditions including sympathetic ophthalmia inflammation of both eyes following trauma to one eye gonococcal ophthalmia trachoma or egyptian ophthalmia ophthalmia neonatorum a conjunctivitis of the newborn due to either of the two previous pathogens photophthalmia and actinic conjunctivitis inflammation resulting from prolonged exposure to ultraviolet rays and others
ophthalmia nodosa is a cutaneous condition characterized by inflammation of the eye due to lodging of for example caterpillar hairs in the conjunctiva cornea or iris
ophthalmodynia periodica is also referred to as ice pick headache needle in the eye syndrome and sharp short lived head pain ophthalmodynia periodica is considered a primary headache disorder so it is not caused by any other conditions another well known name for ophthalmodynia periodica is jabs and jolts syndrome
ophthalmoparesis or ophthalmoplegia refers to weakness paresis or paralysis plegia of one or more extraocular muscles which are responsible for eye movements it is a physical finding in certain neurologic ophthalmologic and endocrine disease
opioid induced hyperalgesia or opioid induced abnormal pain sensitivity also called paradoxical hyperalgesia is a phenomenon associated with the long term use of opioids such as morphine hydrocodone oxycodone and methadone over time individuals taking opioids can develop an increasing sensitivity to noxious stimuli even evolving a painful response to previously non noxious stimuli allodynia some studies on animals have also demonstrated this effect occurring after only a single high dose of opioids although tolerance and opioid induced hyperalgesia both result in a similar need for dose escalation they are nevertheless caused by two distinct mechanisms the similar net effect makes the two phenomena difficult to distinguish in a clinical setting under chronic opioid treatment a particular individual s requirement for dose escalation may be due to tolerance desensitization of antinociceptive mechanisms opioid induced hyperalgesia sensitization of pronociceptive mechanisms or a combination of both identifying the development of hyperalgesia is of great clinical importance since patients receiving opioids to relieve pain may paradoxically experience more pain as a result of treatment whereas increasing the dose of opioid can be an effective way to overcome tolerance doing so to compensate for opioid induced hyperalgesia may worsen the patient s condition by increasing sensitivity to pain while escalating physical dependence the phenomenon is common among palliative care patients following a too rapid escalation of opioid dosage
opioid overdose is an acute condition due to excessive opioids examples of opioids are morphine heroin tramadol oxycodone and methadone it differs from opioid dependency although opioid overdose does not constitute a majority of the overdoses seen in the emergency department it is important to rule out in people given its potential for mortality and the ease of reversal dependence on prescription opioids can stem from treatment of chronic pain and in recent years is the cause of the increased number of opioid overdoses initial treatment involves supporting the persons breathing and providing oxygen naloxone is then recommended among those who are not breathing opioid use disorders resulted in 51 000 worldwide deaths in 2013 up from 18 000 deaths in 1990 prescription opioid overdose was responsible for more deaths in the united states from 1999 2008 than heroin and cocaine overdose combined
an opioid use disorder is a medical condition that is characterized by the compulsive use of opioids despite adverse consequences from continued use and the development of a withdrawal syndrome when opioid use stops it involves both an addiction to and dependence upon opioids opioids include substances such as morphine heroin codeine oxycodone hydrocodone etc the necessary descriptive characteristics of the medical diagnosis are preoccupation with a desire to obtain and take the drug and persistent drug seeking behaviour the opioid dependence withdrawal syndrome involves both psychological dependence and marked physical dependence upon opioid compounds opioid use disorders resulted in 51 000 deaths worldwide in 2013 up from 18 000 deaths in 1990
opisthorchiasis is a parasitic disease caused by species in the genus opisthorchis specifically opisthorchis viverrini and opisthorchis felineus medical care and loss of wages caused by opisthorchis viverrini in laos and in thailand costs about 120 million annually or 120 million per year can cost northeast thailand only infection of opisthorchis viverrini and of other liver flukes in asia affect the poor and poorest people opisthorchiasis has received less attention than other diseases and is a neglected disease in asia
opitz g bbb syndrome also known as opitz syndrome g syndrome or bbb syndrome is a rare genetic disorder that will affect physical structures along the midline of the body the letters g and bbb represent the last names of the families that were first diagnosed with the disorder while opitz is the last name of the doctor that first described the signs and symptoms of the disease there are two different forms of optiz g bbb syndrome x linked recessive syndrome type i xlos osx and dominant autosomal syndrome type ii ados however both result in common physical deformities although their pattern of inheritance may differ several other names for the disease s are no longer used these include hypospadias dysphagia syndrome opitz frias syndrome telecanthus with associated abnormalities and hypertelorism hypospadias syndrome one out of every 50 000 to 100 000 males is born with x linked type ii optiz g bbb syndrome but professionals believe that condition is under diagnosed and there are actually many more cases it is unknown as to how many autosomal dominant cases exist however the autosomal dominant cases are also categorized under a more commonly diagnosed group called 22 q 11 2 deletion syndrome this group includes several other diseases that all result because of a small deletion of chromosome 22 at the q 11 2 location
the oppenheimer – phillips process or strip reaction is a type of deuteron induced nuclear reaction in this process the neutron half of an energetic deuteron a stable isotope of hydrogen with one proton and one neutron fuses with a target nucleus transmuting the target to a heavier isotope while ejecting a proton an example is the nuclear transmutation of carbon 12 to carbon 13 the process allows a nuclear interaction to take place at lower energies than would be expected from a simple calculation of the coulomb barrier between a deuteron and a target nucleus this is because as the deuteron approaches the positively charged target nucleus it experiences a charge polarization where the proton end faces away from the target and the neutron end faces towards the target the fusion proceeds when the binding energy of the neutron and the target nucleus exceeds the binding energy of the deuteron and a proton is then repelled from the new heavier nucleus
oppermann s conjecture is an unsolved problem in mathematics on the distribution of prime numbers it is closely related to but stronger than legendre s conjecture andrica s conjecture and brocard s conjecture it is named after danish mathematician ludvig oppermann who posed it in 1882
an opportunistic infection is an infection caused by pathogens bacteria viruses fungi or protozoa that take advantage of an opportunity not normally available such as a host with a weakened immune system an altered microbiota such as a disrupted gut flora or breached integumentary barriers many of these pathogens do not cause disease in a healthy host that has a normal immune system however a compromised immune system a penetrating injury or a lack of competition from normal commensals presents an opportunity for the pathogen to infect
oppositional defiant disorder odd is defined by the dsm 5 as a pattern of angry irritable mood argumentative defiant behavior or vindictiveness lasting at least six months unlike children with conduct disorder cd children with oppositional defiant disorder are not aggressive towards people or animals do not destroy property and do not show a pattern of theft or deceit a diagnosis of odd is also no longer applicable if the individual is diagnosed with reactive attachment disorder rad
opsismodysplasia is a type of skeletal dysplasia a bone disease that interferes with bone development first described by zonana and associates in 1977 and designated under its current name by maroteaux 1984 derived from the greek opsismos late the name opsismodysplasia describes a delay in bone maturation in addition to this delay the disorder is characterized by micromelia short or undersized bones particularly of the hands and feet delay of ossification bone cell formation platyspondyly flattened vertebrae irregular metaphyses an array of facial aberrations and respiratory distress related to chronic infection opsismodysplasia is congenital being apparent at birth it has a variable mortality with some affected individuals living to adulthood the disorder is rare with an incidence of less than 1 per 1 000 000 worldwide it is inherited in an autosomal recessive pattern which means the defective mutated gene that causes the disorder is located on an autosome and the disorder occurs when two copies of this defective gene are inherited no specific gene has been found to be associated with the disorder it is similar to spondylometaphyseal dysplasia sedaghatian type
opsoclonus refers to uncontrolled eye movement opsoclonus consists of rapid involuntary multivectorial horizontal and vertical unpredictable conjugate fast eye movements without intersaccadic intervals it is also referred to as saccadomania or reflexive saccade the movements of opsoclonus may have a very small amplitude appearing as tiny deviations from primary position possible etiologies of opsoclonus include neuroblastoma and encephalitis in children and breast lung or ovarian cancer in adults other considerations include multiple sclerosis toxins or medication effects e g serotonin syndrome it can also be caused by a lesion in the omnipause neurons which tonically inhibit initiation of saccadic eye movement until signaled by the superior colliculus by blocking paramedian pontine reticular formation pprf burst neurons in the pons it frequently occurs along with myoclonus in opsoclonus myoclonus syndrome
opsoclonus myoclonus syndrome oms also known as opsoclonus myoclonus ataxia oma is a rare neurological disorder of unknown causes which appears to be the result of an autoimmune process involving the nervous system it is an extremely rare condition affecting as few as 1 in 10 000 000 people per year it affects 2 to 3 of children with neuroblastoma and has been reported to occur with celiac disease
optic disc drusen odd or optic nerve head drusen onhd are globules of mucoproteins and mucopolysaccharides that progressively calcify in the optic disc they are thought to be the remnants of the axonal transport system of degenerated retinal ganglion cells odd have also been referred to as congenitally elevated or anomalous discs pseudopapilledema pseudoneuritis buried disc drusen and disc hyaline bodies they may be associated with vision loss of varying degree occasionally resulting in blindness
optic nerve glioma or optic glioma a form of glioma which affects the optic nerve is often one of the central nervous system manifestations of neurofibromatosis 1 optic gliomas are usually pilocytic tumors and can involve the optic nerve or optic chiasm optic gliomas are usually associated with neurofibromatosis type 1 in 30 of patients
optic nerve hypoplasia onh is a medical condition arising from the underdevelopment of the optic nerve s this condition is the most common congenital optic nerve anomaly the optic disc appears abnormally small because not all the optic nerve axons have developed properly it is often associated with endocrinopathies hormone deficiencies developmental delay and brain malformations the optic nerve which is responsible for transmitting visual signals from the retina to the brain has approximately 1 2 million nerve fibers in the average person in those diagnosed with onh however there are noticeably fewer nerves
optic nerve sheath meningiomas onsm are rare benign tumors of the optic nerve 60 – 70 of cases occur in middle age females and is more common in older adults mean age 44 7 years it is also seen in children but this is rare the tumors grow from cells that surround the optic nerve and as the tumor grows it compresses the optic nerve this causes loss of vision in the affected eye rarely it may affect both eyes at the same time it is typically a slow growing tumor and has never been reported to cause death however there is concern that the tumor can grow into the brain and cause other types of neurological damage in some patients the tumor grows so slowly that treatment is not necessary standard treatments are observation surgery radiation therapy and combinations of the above
an optic nerve melanocytoma is a tumor made up of melanocytes and melanin these tumors are typically a benign they can grow but rarely transform into a malignancy even so local growth can affect adjacent tissues
optic neuritis is a demyelinating inflammation of the optic nerve it is also known as optic papillitis when the head of the optic nerve is involved and retrobulbar neuritis when the posterior of the nerve is involved it is most often associated with multiple sclerosis and it may lead to complete or partial loss of vision in one or both eyes partial transient vision loss lasting less than one hour can be an indication of early onset multiple sclerosis other possible diagnoses include diabetes mellitus low phosphorus levels or hyperkalaemia
optic neuropathy refers to damage to the optic nerve due to any cause damage and death of these nerve cells or neurons leads to characteristic features of optic neuropathy the main symptom is loss of vision with colors appearing subtly washed out in the affected eye on medical examination the optic nerve head can be visualised by an ophthalmoscope a pale disc is characteristic of long standing optic neuropathy in many cases only one eye is affected and patients may not be aware of the loss of color vision until the doctor asks them to cover the healthy eye optic neuropathy is often called optic atrophy to describe the loss of some or most of the fibers of the optic nerve in medicine atrophy usually means shrunken but capable of regrowth so some argue that optic atrophy as a pathological term is somewhat misleading and the term optic neuropathy should be used instead in short optic atrophy is the end result of any disease that damages nerve cells anywhere between the retinal ganglion cells and the lateral geniculate body anterior visual system
optic papillitis is a specific type of optic neuritis inflammation of the optic nerve head is called papillitis or intraocular optic neuritis inflammation of the orbital portion of the nerve is called retrobulbar optic neuritis or orbital optic neuritis it is often associated with substantial losses in visual fields pain on moving the globe and sensitivity to light pressure on the globe it is often an early sign of multiple sclerosis papillitis may have the same appearance as papilledema however papillitis may be unilateral whereas papilledema is almost always bilateral papillitis can be differentiated from papilledema by an afferent pupillary defect marcus gunn pupil by its greater effect in decreasing visual acuity and color vision and by the presence of a central scotoma papilledema that is not yet chronic will not have as dramatic an effect on vision because increased intracranial pressure can cause both papilledema and a sixth abducens nerve palsy papilledema can be differentiated from papillitis if esotropia and loss of abduction are also present however esotropia may also develop secondarily in an eye that has lost vision from papillitis retrobulbar neuritis an inflamed optic nerve but with a normal appearing nerve head is associated with pain and the other findings of papillitis pseudopapilledema is a normal variant of the optic disk in which the disk appears elevated with indistinct margins and a normal vascular pattern pseudopapilledema sometimes occurs in hyperopic individuals workup of the patient with papillitis includes lumbar puncture and cerebrospinal fluid analysis b henselae infection can be detected by serology mri is the preferred imaging study an abnormal mri is associated with a worse visual outcome
an optical black hole is a phenomenon in which slow light is passed through a bose – einstein condensate that is itself spinning faster than the local speed of light within to create a vortex capable of trapping the light behind an event horizon just as a gravitational black hole would unlike other black hole analogs such as a sonic black hole in a bose – einstein condensate a slow light black hole analog is not expected to mimic the quantum effects of a black hole and thus not emit hawking radiation it does however mimic the classical properties of a gravitational black hole making it potentially useful in studying other properties of black holes more recently some physicists have developed a fiber optic based system which they believe will emit hawking radiation
optical flow or optic flow is the pattern of apparent motion of objects surfaces and edges in a visual scene caused by the relative motion between an observer an eye or a camera and the scene the concept of optical flow was introduced by the american psychologist james j gibson in the 1940 s to describe the visual stimulus provided to animals moving through the world gibson stressed the importance of optic flow for affordance perception the ability to discern possibilities for action within the environment followers of gibson and his ecological approach to psychology have further demonstrated the role of the optical flow stimulus for the perception of movement by the observer in the world perception of the shape distance and movement of objects in the world and the control of locomotion the term optical flow is also used by roboticists encompassing related techniques from image processing and control of navigation including motion detection object segmentation time to contact information focus of expansion calculations luminance motion compensated encoding and stereo disparity measurement
the optical force is a phenomenon whereby beams of light can attract and repel each other the force acts along an axis which is perpendicular to the light beams because of this parallel beams can be induced to converge or diverge the optical force works on a microscopic scale and cannot currently be detected at larger scales it was discovered by a team of yale researchers led by electrical engineer hong tang
optical physics is a subfield of atomic molecular and optical physics it is the study of the generation of electromagnetic radiation the properties of that radiation and the interaction of that radiation with matter especially its manipulation and control it differs from general optics and optical engineering in that it is focused on the discovery and application of new phenomena there is no strong distinction however between optical physics applied optics and optical engineering since the devices of optical engineering and the applications of applied optics are necessary for basic research in optical physics and that research leads to the development of new devices and applications often the same people are involved in both the basic research and the applied technology development for example the experimental demonstration of electromagnetically induced transparency by s e harris and of slow light by harris and lene vestergaard hau researchers in optical physics use and develop light sources that span the electromagnetic spectrum from microwaves to x rays the field includes the generation and detection of light linear and nonlinear optical processes and spectroscopy lasers and laser spectroscopy have transformed optical science major study in optical physics is also devoted to quantum optics and coherence and to femtosecond optics in optical physics research is also encouraged in areas such as the nonlinear response of isolated atoms to intense ultra short electromagnetic fields the atom cavity interaction at high fields and quantum properties of the electromagnetic field other important areas of research include the development of novel optical techniques for nano optical measurements diffractive optics low coherence interferometry optical coherence tomography and near field microscopy research in optical physics places an emphasis on ultrafast optical science and technology the applications of optical physics create advancements in communications medicine manufacturing and even entertainment
in an optical communications link the optical power margin is the difference between the optical power that is launched by a given transmitter into the fiber less transmission losses from all causes and the minimum optical power that is required by the receiver for a specified level of performance an optical power margin is typically measured using a calibrated light source and an optical power meter the optical power margin is usually expressed in decibels db at least several db of optical power margin should be included in the optical power budget the amount of optical power launched into a given fiber by a given transmitter depends on the nature of its active optical source led or laser diode and the type of fiber including such parameters as core diameter and numerical aperture
the optical transfer function otf is the transfer function of an optical system such as a camera microscope human eye or projector it is used by optical engineers and scientists to describe how the optics project light from the object or scene onto a photographic film detector array retina screen or simply the next item in the transmission chain the function specifies the translation and contrast reduction of a periodic sine wave pattern after passing through the lens system as a function of its periodicity and orientation formally the optical transfer function is defined as the fourier transform of the point spread function or impulse response of the optics i e the image of a point source when this image does not change shape upon lateral translation of the point source the optical transfer function can be used to study the projection of arbitrary objects or scenes onto the detector or film while figures of merit such as contrast sensitivity and resolution give an intuitive indication of performance the optical transfer function provides a comprehensive and well defined characterization of optical systems
in mathematics and computer science an optimization problem is the problem of finding the best solution from all feasible solutions optimization problems can be divided into two categories depending on whether the variables are continuous or discrete an optimization problem with discrete variables is known as a combinatorial optimization problem in a combinatorial optimization problem we are looking for an object such as an integer permutation or graph from a finite or possibly countable infinite set problems with continuous variables include constrained problems and multimodal problems
optimized power control also known as optimum power calibration abbreviated opc is a function of an optical disc recorder it checks the proper writing power and reflection of the media in use calculating the optimum laser power and adjusting it for writing the particular session more sophisticated is active opc or running opc active opc monitors writing power and reflection of the media in use calculating the optimum laser power and adjusting it in real time which in theory should result in a better quality burn
oral allergy syndrome oas is a type of food allergy classified by a cluster of allergic reactions in the mouth in response to eating certain usually fresh fruits nuts and vegetables that typically develops in adults with hay fever oas is perhaps the most common food related allergy in adults oas is not a separate food allergy but rather represents cross reactivity between distant remnants of tree or weed pollen still found in certain fruits and vegetables therefore oas is typically only seen in tree and weed allergic patients and is usually limited to ingestion of only uncooked fruits or vegetables another term used for this syndrome is pollen food allergy in adults up to 60 of all food allergic reactions are due to cross reactions between foods and inhalative allergens oas is a type 1 or ige mediated immune response which is sometimes called a true allergy the body s immune system produces ige antibodies against pollen in oas these antibodies also bind to or cross react with other structurally similar proteins found in botanically related plants oas can occur any time of the year but is most prevalent during the pollen season individuals with oas usually develop symptoms within a few minutes after eating the food
oral and maxillofacial pathology also termed oral pathology stomatognathic disease dental disease or mouth disease refers to the diseases of the mouth oral cavity or stoma jaws maxillae or gnath and related structures such as salivary glands temporomandibular joints facial muscles and perioral skin the skin around the mouth the mouth is an important organ with many different functions it is also prone to a variety of medical and dental disorders the specialty oral and maxillofacial pathology is concerned with diagnosis and study of the causes and effects of diseases affecting the oral and maxillofacial region it is sometimes considered to be a specialty of dentistry and pathology sometimes the term head and neck pathology is used instead but this might imply that the pathologist deals with otorhinolaryngologic disorders i e ear nose and throat in addition to maxillofacial disorders in this role there is some overlap between the expertise of head and neck pathologists and that of endocrine pathologists
oral cancer also known as mouth cancer is a type of head and neck cancer and is any cancerous tissue growth located in the oral cavity it may arise as a primary lesion originating in any of the tissues in the mouth by metastasis from a distant site of origin or by extension from a neighboring anatomic structure such as the nasal cavity alternatively the oral cancers may originate in any of the tissues of the mouth and may be of varied histologic types teratoma adenocarcinoma derived from a major or minor salivary gland lymphoma from tonsillar or other lymphoid tissue or melanoma from the pigment producing cells of the oral mucosa there are several types of oral cancers but around 90 are squamous cell carcinomas originating in the tissues that line the mouth and lips oral or mouth cancer most commonly involves the tongue it may also occur on the floor of the mouth cheek lining gingiva gums lips or palate roof of the mouth most oral cancers look very similar under the microscope and are called squamous cell carcinoma but less commonly other types of oral cancer occur such as kaposi s sarcoma in 2013 oral cancer resulted in 135 000 deaths up from 84 000 deaths in 1990 five year survival rates in the united states are 63
oral candidiasis also known as oral candidosis oral thrush oropharyngeal candidiasis moniliasis candidal stomatitis muguet is candidiasis that occurs in the mouth that is oral candidiasis is a mycosis yeast fungal infection of candida species on the mucous membranes of the mouth candida albicans is the most commonly implicated organism in this condition c albicans is carried in the mouths of about 50 of the world s population as a normal component of the oral microbiota this candidal carriage state is not considered a disease but when candida species become pathogenic and invade host tissues oral candidiasis can occur this change usually constitutes an opportunistic infection of normally harmless micro organisms because of local i e mucosal or systemic factors altering host immunity
oral florid papillomatosis is a condition characterized by a white mass resembling a cauliflower covering the tongue and extending onto other portions of the mucous membranes this is a type of verrucous carcinoma
oral melanosis is pigmentation of the oral cavity that tends to occur most frequently in black people
oral mucocele also termed mucous retention cyst mucous extravasation cyst mucous cyst of the oral mucosa and mucous retention and extravasation phenomena is a clinical term that refers to two related phenomena mucus extravasation phenomenon mucus retention cyst the former is a swelling of connective tissue consisting of a collection of fluid called mucin this occurs because of a ruptured salivary gland duct usually caused by local trauma damage in the case of mucus extravasation phenomenon and an obstructed or ruptured salivary duct parotid duct in the case of a mucus retention cyst the mucocele has a bluish translucent color and is more commonly found in children and young adults although the term cyst is often used to refer to these lesions mucoceles are not strictly speaking true cysts because there is no epithelial lining rather it would be more accurate to classify mucoceles as polyps i e a lump
oral submucous fibrosis osmf or osf is a chronic complex premalignant 1 transformation risk lesion of the oral cavity characterized by juxta epithelial inflammatory reaction and progressive fibrosis of the submucosal tissues the lamina propria and deeper connective tissues as the disease progresses the jaws become rigid to the point that the person is unable to open the mouth the condition is remotely linked to oral cancers and is associated with areca nut or betel quid chewing a habit similar to tobacco chewing is practiced predominantly in southeast asia and india dating back thousands of years
an oral torus is a lesion made of compact bone and occurs along the palate or the mandible inside the mouth the palatal torus or torus palatinus occurs along the palate close to the midline whereas the mandibular torus or torus mandibularis occur along the lingual side of the mandible occurrences of tori are more frequent in women then they are in men tori are associated with adulthood and rarely appear before the age of 15 the palatal version of tori have a higher occurrence in native american and inuit populations treatment is not necessary unless they become an obstruction to chewing or prosthetic appliances
the orange tornadoes and newark tornadoes were two manifestations of a long lived professional american football franchise that existed in some form from 1887 to 1941 and from 1958 to 1970 having played in the national football league from 1929 to 1930 the american association from 1936 to 1941 the atlantic coast football league from 1963 to 1964 and 1970 and the continental football league from 1965 to 1969 the team was based for most of its history in orange new jersey with many of its later years in newark its last five seasons of existence were as the orlando panthers when the team was based in orlando florida the nfl franchise was sold back to the league in october 1930 the team had four head coaches in its two years in the nfl – jack depler in orange and jack fish al mcgall and andy salata in newark
oranjegekte orange craze or oranjekoorts orange fever is a phenomenon in the netherlands that occurs during major sporting events especially international football championships and during koningsdag an annual holiday celebrating the king s birthday it manifests itself in the wearing of orange clothing such as t shirts caps and scarfs lavish attention for sports and sports fans in the media and the decoration of cars rooms houses shops and even entire streets in orange the traditional color of the dutch royal family the house of orange nassau
an orbital blowout fracture is a traumatic deformity of the orbital floor or medial wall typically resulting from impact of a blunt object larger than the orbital aperture or eye socket there are two broad categories of blowout fractures open door which are large displaced and comminuted and trapdoor which are linear hinged and minimally displaced they are characterized by double vision sunken ocular globes and loss of sensation of the cheek and upper gums due to infraorbital nerve injury in pure orbital blowout fractures the orbital rim the most anterior bony margin of the orbit is preserved while with impure fractures the orbital rim is also injured with the trapdoor variant there is a high frequency of extra ocular muscle entrapment despite minimal signs of external trauma a phenomenon referred to as a white eyed orbital blowout fracture they can occur with other injuries such as transfacial le fort fractures or zygomaticomaxillary complex fractures the most common causes are assault and motor vehicle accidents in children the trapdoor subtype are more common reconstruction is usually performed with a titanium mesh or porous polyethylene through a transconjunctival or subciliary incision more recently there has been success with endoscopic or minimally invasive approaches
orbital cellulitis is inflammation of eye tissues behind the orbital septum it most commonly refers to an acute spread of infection into the eye socket from either the adjacent sinuses or through the blood when it affects the rear of the eye it is known as retro orbital cellulitis it should not be confused with periorbital cellulitis which refers to cellulitis anterior to the septum
orbital forcing is the effect on climate of slow changes in the tilt of the earth s axis and shape of the orbit see milankovitch cycles these orbital changes change the total amount of sunlight reaching the earth by up to 25 at mid latitudes from 400 to 500 wm − 2 at latitudes of 60 degrees in this context the term forcing signifies a physical process that affects the earth s climate this mechanism is believed to be responsible for the timing of the ice age cycles a strict application of the milankovitch theory does not allow the prediction of a sudden ice age rapid being anything under a century or two since the fastest orbital period is about 20 000 years the timing of past glacial periods coincides very well with the predictions of the milankovitch theory and these effects can be calculated into the future
orbital lymphoma is a common type of non hodgkin lymphoma that occurs near or on the eye common symptoms include decreased vision and uveitis orbital lymphoma can be diagnosed via a biopsy of the eye and is usually treated with radiotherapy or with combination with chemotherapy
orchialgia is long term pain of the testes it is considered chronic if it has persisted for more than 3 months orchialgia may be caused by injury infection surgery cancer or testicular torsion and is a possible complication after vasectomy igg 4 related disease is a more recently identified cause of chronic orchialgia one author describes the syndromes of chronic testicular pain thus the complaint is of a squeezing deep ache in the testis like the day after you got kicked there often bilateral or alternating from one side to the other intermittent and most commonly associated with lower back pain sometimes it feels like the testicle is pinched in the crotch of the underwear but trouser readjustment does not help there may also be pain in the inguinal area but no nausea or other symptoms back pain may be concurrent or absent and some patients have a long history of low back pain onset of pain is commonly related to activity that would stress the low back such as lifting heavy objects other stresses that might cause low back pain are imaginative coital positions jogging sitting hunched over a computer long car driving or other such positions of unsupported seating posture that flattens the normal lumbar lordosis curve
orchitis ˌɔːrˈkaɪtɪs or orchiditis ˌɔːrkɪˈdaɪtɪs from the ancient greek ὄρχις meaning testicle same root as orchid is inflammation of the testes it can also involve swelling heavy pains and frequent infection and is more rarely known as didymitis as in epididymis
ord s thyroiditis is a common form of thyroiditis an autoimmune disease where the body s own antibodies fight the cells of the thyroid it is named after the physician william miller ord who first described it in 1877 and again in 1888 it is more common among women than men
in mathematical logic and set theory an ordinal notation is a partial function from the set of all finite sequences of symbols from a finite alphabet to a countable set of ordinals and a gödel numbering is a function from the set of well formed formulae a well formed formula is a finite sequence of symbols on which the ordinal notation function is defined of some formal language to the natural numbers this associates each wff with a unique natural number called its gödel number if a gödel numbering is fixed then the subset relation on the ordinals induces an ordering on well formed formulae which in turn induces a well ordering on the subset of natural numbers a recursive ordinal notation must satisfy the following two additional properties 1 the subset of natural numbers is a recursive set 2 the induced well ordering on the subset of natural numbers is a recursive relation there are many such schemes of ordinal notations including schemes by wilhelm ackermann heinz bachmann wilfried buchholz georg cantor solomon feferman gerhard jäger isles pfeiffer wolfram pohlers kurt schütte gaisi takeuti called ordinal diagrams oswald veblen stephen cole kleene has a system of notations called kleene s o which includes ordinal notations but it is not as well behaved as the other systems described here usually one proceeds by defining several functions from ordinals to ordinals and representing each such function by a symbol in many systems such as veblen s well known system the functions are normal functions that is they are strictly increasing and continuous in at least one of their arguments and increasing in other arguments another desirable property for such functions is that the value of the function is greater than each of its arguments so that an ordinal is always being described in terms of smaller ordinals there are several such desirable properties unfortunately no one system can have all of them since they contradict each other
in a quarry near what is now putilovo village russia near saint petersburg are large deposits of ordovician clay in this clay the most abundant genus is asaphus a trilobite
in mathematics especially in the area of algebra known as ring theory the ore condition is a condition introduced by øystein ore in connection with the question of extending beyond commutative rings the construction of a field of fractions or more generally localization of a ring the right ore condition for a multiplicative subset s of a ring r is that for a ∈ r and s ∈ s the intersection as ∩ sr ≠ ∅ a domain whose set of non zero elements satisfies the right ore condition is called a right ore domain the left case is defined similarly
orf is an exanthemous disease caused by a parapox virus and occurring primarily in sheep and goats it is also known as contagious pustular dermatitis infectious labial dermatitis ecthyma contagiosum thistle disease and scabby mouth orf virus is zoonotic it can also infect humans
organ dysfunction is a condition where an organ does not perform its expected function organ failure is organ dysfunction to such a degree that normal homeostasis cannot be maintained without external clinical intervention it is not a diagnosis it can be classified by the cause but when the cause is not known it can also be classified by whether the onset is chronic or acute multiple organ failure can be associated with sepsis and is often fatal countries such as spain have shown a rise in mortality risk due to a large elderly population there however there are tools physicians use when diagnosing multiple organ failure and when prognosing the outcome the sequential organ failure assessment sofa score uses early lab values in a patient s hospitalization within 24 hours to predict fatal outcomes for a patient
organ perforation is a complete penetration of the wall of a hollow organ in the body such as the gastrointestinal tract in the case of gastrointestinal perforation it mainly refers to accidental or pathologic perforation rather than intentional penetration during surgery types include gastrointestinal perforation and uterine perforation
an organic brain syndrome obs also known as an organic brain disease disorder obd an organic mental syndrome oms or an organic mental disorder omd is a syndrome or disorder of mental function whose cause is alleged to be known as organic physiologic rather than purely of the mind these names are older and nearly obsolete general terms from psychiatry referring to many physical disorders that cause impaired mental function they are meant to exclude psychiatric disorders mental disorders originally the term was created to distinguish physical termed organic causes of mental impairment from psychiatric termed functional disorders but during the era when this distinction was drawn not enough was known about brain science including neuroscience cognitive science neuropsychology and mind brain correlation for this etiologic classification to be more than educated guesswork labeled with misplaced certainty which is why it has been deemphasized in current medicine acute organic brain syndrome is by definition a recently appearing state of mental impairment as a result of intoxication drug overdose infection pain and many other physical problems affecting mental status in medical contexts acute means of recent onset as is the case with most acute disease problems acute organic brain syndrome is often temporary although this does not guarantee that it will not recur happen again or progress to become chronic that is long term a more specific medical term for the acute subset of organic brain syndromes is delirium chronic organic brain syndrome is long term for example some forms of chronic drug or alcohol dependence can cause organic brain syndrome due to their long lasting or permanent toxic effects on brain function other common causes of chronic organic brain syndrome sometimes listed are the various types of dementia which result from permanent brain damage due to strokes alzheimer s disease or other damaging causes which are not reversible though obs was once a common diagnosis in the elderly until the understanding of the various types of dementias it is related to a disease process and is not an inevitable part of aging in some of the older literature there was an attempt to separate organic brain syndrome from dementia but this was related to an older world view in which dementia was thought to be a part of normal aging and thus did not represent a special disease process the later identification of various dementias as clear pathologies is an example of the types of pathological problems discovered to be associated with mental states and is one of the areas which led to abandonment of all further attempts to clearly define and use obs as a term
an organic mental disorder omd also known as organic brain syndrome or chronic organic brain syndrome is a form of decreased mental function due to a medical or physical disease rather than a psychiatric illness this differs from dementia while mental or behavioral abnormalities related to the dysfunction can be permanent treating the disease early may prevent permanent damage in addition to fully restoring mental functions an organic cause to brain dysfunction is suspected when there is no indication of a clearly defined psychiatric or inorganic cause such as a mood disorder now the dsm iv tr diagnostic and statistical manual of mental disorders 4 th edition text revision has broken up the diagnoses that once fell under the diagnostic category organic mental disorder into three categories delirium dementia and amnestic organic brain syndrome can be divided into 2 major subgroups acute delirium or acute confusional state and chronic dementia a third entity encephalopathy subacute organic brain syndrome denotes a gray zone between delirium and dementia its early course may fluctuate but it is often persistent and progressive damage to brain functioning could be due not only to organic physical injury a severe blow to the head stroke chemical and toxic exposures organic brain disease substance abuse etc and also to non organic means such as severe deprivation abuse neglect and severe psychological trauma
the oldest organic reactions are combustion of organic fuels and saponification of fats to make soap modern organic chemistry starts with the wöhler synthesis in 1828 in the history of the nobel prize in chemistry awards have been given for the invention of specific organic reactions such as the grignard reaction in 1912 the diels alder reaction in 1950 the wittig reaction in 1979 and olefin metathesis in 2005
organic reductions or organic oxidations or organic redox reactions are redox reactions that take place with organic compounds in organic chemistry oxidations and reductions are different from ordinary redox reactions because many reactions carry the name but do not actually involve electron transfer in the electrochemical sense of the word instead the relevant criterion for organic oxidation is gain of oxygen and or loss of hydrogen simple functional groups can be arranged in order of increasing oxidation state the oxidation numbers are only an approximation when methane is oxidized to carbon dioxide its oxidation number changes from − 4 to 4 classical reductions include alkene reduction to alkanes and classical oxidations include oxidation of alcohols to aldehydes in oxidations electrons are removed and the electron density of a molecule is reduced in reductions electron density increases when electrons are added to the molecule this terminology is always centered on the organic compound for example it is usual to refer to the reduction of a ketone by lithium aluminium hydride but not to the oxidation of lithium aluminium hydride by a ketone many oxidations involve removal of hydrogen atoms from the organic molecule and the reverse reduction adds hydrogens to an organic molecule many reactions classified as reductions also appear in other classes for instance conversion of the ketone to an alcohol by lithium aluminium hydride can be considered a reduction but the hydride is also a good nucleophile in nucleophilic substitution many redox reactions in organic chemistry have coupling reaction reaction mechanism involving free radical intermediates true organic redox chemistry can be found in electrochemical organic synthesis or electrosynthesis examples of organic reactions that can take place in an electrochemical cell are the kolbe electrolysis in disproportionation reactions the reactant is both oxidised and reduced in the same chemical reaction forming two separate compounds asymmetric catalytic reductions and asymmetric catalytic oxidations are important in asymmetric synthesis
organised crime in australia refers to the activities of various groups of crime families and or organised crime syndicates organised crime is a phenomenon that has emerged in different cultures and countries around the world it is ubiquitous internationalised and not exclusive to certain geographical areas to singular ethnic groups or to particular social systems though local areas may exhibit great diversity in their social response to such activity australia as a relatively young first world free market democracy provides a socio economic and political environment that is unique to the understanding of organised crime melbourne has been known as the organised crime capital in australia over the decades with high profile gangland and underworld figures and events taking place
organizational communication is a subfield of the larger discipline of communication studies organizational communication as a field is the consideration analysis and criticism of the role of communication in organizational contexts its main function is to inform persuade and promote goodwill the flow of communication could be either formal or informal communication flowing through formal channels are downward horizontal and upward whereas communication through informal channels are generally termed as grapevine
organomegaly is the abnormal enlargement of organs for example clitoromegaly is the enlargement of the clitoris hepatomegaly is enlargement of the liver cardiomegaly is enlargement of the heart and splenomegaly is enlargement of the spleen
organophosphate induced delayed neuropathy opidn also called organophosphate induced delayed polyneuropathy opidp is a neuropathy caused by killing of neurons in the central nervous system especially in the spinal cord as a result of acute or chronic organophosphate poisoning a striking example of opidn occurred during the 1930 s prohibition era when thousands of men in the american south and midwest developed arm and leg weakness and pain after drinking a medicinal alcohol substitute the drink called ginger jake contained an adulterated jamaican ginger extract containing tri ortho cresyl phosphate tocp which resulted in partially reversible neurologic damage the damage resulted in the limping jake leg or jake walk which were terms frequently used in the blues music of the period europe and morocco both experienced outbreaks of tocp poisoning from contaminated abortifacients and cooking oil respectively opidn can be induced by diisopropylfluorophosphate which is used for this purpose as an experimental agent there is no specific treatment regular physiotherapy may help recovery is often incomplete
organophosphate poisoning results from exposure to organophosphates ops which cause the inhibition of acetylcholinesterase ache leading to the accumulation of acetylcholine ach in the body organophosphate poisoning most commonly results from exposure to insecticides or nerve agents ops are one of the most common causes of poisoning worldwide are usually associated suicides in agrarian areas there are around 1 million op poisonings per year with several hundred thousand resulting in fatalities annually organophosphates inhibit ache causing op poisoning by phosphorylating the serine hydroxyl residue on ache which inactivates ache ache is critical for nerve function so the irreversible blockage of this enzyme which causes acetylcholine accumulation results in muscle overstimulation this causes disturbances across the cholinergic synapses and can only be reactivated very slowly if at all paraoxonase pon 1 is a key enzyme involved in op pesticides and has been found to be critical in determining an organism s sensitivity to op exposure
within the work of the austrian psychoanalyst wilhelm reich 1897 – 1957 orgastic potency is the ability to experience an orgasm with specific psychosomatic characteristics and among others requiring the ability to love for reich orgastic impotence or failure to attain orgastic potency not to be confused with anorgasmia the inability to reach orgasm always resulted in neurosis because during orgasm that person could not discharge all libido which reich regarded as a biological energy according to reich not a single neurotic individual possesses orgastic potency reich coined the term orgastic impotence in 1924 and described the concept in his 1927 book die funktion des orgasmus the manuscript of which he presented to sigmund freud on the latter s 70 th birthday though reich regarded his work as complementing freud s original theory of anxiety neurosis freud was ambivalent in his reception freud s view was that there was no single cause of neurosis reich continued to use the concept as an indicator of a person s health in his later therapeutic methods such as vegetotherapy during the period 1933 – 1937 he attempted to ground his orgasm theory in physiology both theoretically and experimentally
orientation is a function of the mind involving awareness of three dimensions time place and person problems with orientation lead to disorientation and can be due to various conditions from delirium to intoxication typically disorientation is first in time then in place and finally in person in the context of an accident or major trauma the emergency medical responder performs spiraling increasingly detailed assessments which guide the critical first response assessment of mental orientation typically lands within the immediate top three priorities 1 safety assess the area safety potential traffic fire overhead underfoot objects and collapse risks rushing water gunfire chemical radiation threats storm conditions downed power lines etc wait for the threat to subside or move the person to safety if and when possible all without endangering oneself 2 abcs note conscious or unconscious then assess airway breathing and circulation factors with priority to any potential gross or debilitating blood loss 3 orientation determine if the person is alert and oriented times three to person place and time this is frequently abbreviated a ox 3 which also serves as a mnemonic the assessment is best done right up front ahead of moving or transporting the victim because it may illuminate potential internal damage mental orientation is closely related and often intermixed with trauma shock including physical shock see shock circulatory and mental shock see acute stress reaction a psychological condition in response to terrifying events the exact cerebral region involved in orientation is uncertain but lesions of the brain stem and the cerebral hemispheres have been reported to cause disorientation suggesting that they act together in maintaining awareness and its subfunction of orientation
ornithinaemia is a blood disorder characterized by high levels of ornithine also known as hyperornithinemia it may be associated with psychomotor retardation or epileptic episodes
ornithine aminotransferase deficiency also known as gyrate atrophy of the choroid and retina is an inborn error of ornithine metabolism caused by decreased activity of the enzyme ornithine aminotransferase biochemically it can be detected by elevated levels of ornithine in the blood clinically it presents initially with poor night vision which slowly progresses to total blindness it is believed to be inherited in an autosomal recessive manner approximately 200 known cases have been reported in the literature the incidence is highest in finland estimated at 1 50 000
ornithine transcarbamylase deficiency also known as otc deficiency is the most common urea cycle disorder in humans ornithine transcarbamylase the defective enzyme in this disorder is the final enzyme in the proximal portion of the urea cycle responsible for converting carbamoyl phosphate and ornithine into citrulline otc deficiency is inherited in an x linked recessive manner meaning males are more commonly affected than females in severely affected individuals ammonia concentrations increase rapidly causing ataxia lethargy and death without rapid intervention otc deficiency is diagnosed using a combination of clinical findings and biochemical testing while confirmation is often done using molecular genetics techniques once an individual has been diagnosed the treatment goal is to avoid precipitating episodes that can cause an increased ammonia concentration the most common treatment combines a low protein diet with nitrogen scavenging agents liver transplant is considered curative for this disease experimental trials of gene therapy using adenoviral vectors resulted in the death of one participant jesse gelsinger and have been discontinued
ornithine translocase deficiency also called hyperornithinemia hyperammonemia homocitrullinuria hhh syndrome is a rare autosomal recessive urea cycle disorder affecting the enzyme ornithine translocase which causes ammonia to accumulate in the blood a condition called hyperammonemia ammonia which is formed when proteins are broken down in the body is toxic if the levels become too high the nervous system is especially sensitive to the effects of excess ammonia
orofacial granulomatosis abbreviated to ofg and also termed granulomatous cheilitis cheilitis granulomatosa cheilitis granulomatosis and oral granulomatosis is a condition characterized by persistent enlargement of the soft tissues of the mouth lips and the area around the mouth on the face the enlargement does not cause any pain but the best treatment and the prognosis are uncertain the mechanism of the enlargement is granulomatous inflammation the underlying cause of the condition is not completely understood and there is disagreement as to how it relates to crohn s disease and sarcoidosis
orofacial myofunctional disorders omd sometimes called “ oral myofunctional disorder and “ tongue thrust ” are muscle disorders of the face mouth lips or jaw recent studies on incidence and prevalence of tongue thrust behaviors are not available however according to the previous research 38 of various populations have omd the incidence is as high as 81 in children exhibiting speech articulation problems kellum 1992
orofaciodigital syndrome 1 ofd 1 also called papillon league and psaume syndrome is an x linked congenital disorder characterized by malformations of the face oral cavity and digits with polycystic kidney disease and variable involvement of the central nervous system
oromandibular dystonia is a form of focal dystonia affecting the mouth jaw and tongue and in this disease it is hard to speak it is associated with bruxism botulinum toxin has been used in treatment
oropharyngeal cancer is a disease in which malignant cells form in the tissue of oropharynx the oropharynx is the middle part of the throat that includes the base of the tongue the tonsils the soft palate and the walls of the pharynx oropharyngeal cancers can be divided into two types hpv positive which are related to human papillomavirus infection and hpv negative cancers which are usually linked to alcohol or tobacco use
oropouche fever is a tropical viral infection a zoonosis similar to dengue fever transmitted by biting midge species culicoides paraensis and mosquitoes from the blood of sloths to humans it occurs mainly in the amazonic region the caribbean and panama the disease is named after the region where it was first described and isolated at the trinidad regional virus laboratory in 1955 the oropouche river in trinidad and tobago and is caused by a specific arbovirus the oropouche virus orov of the bunyaviridae family
orotic aciduria is a disease yielding an excessive excretion of orotic acid in urine it causes a characteristic form of anemia and may be associated with mental and physical retardation orotic acid is an intermediate product in pyrimidine synthesis pathway a subsequent product of which plays a role in conversion between dihydrofolate and tetrahydrofolate orotic aciduria is associated with megaloblastic anemia due to decreased pyrimidine synthesis which leads to decreased nucleotide lipid cofactors needed for erythrocyte membrane synthesis in the bone marrow
in statistics and signal processing the orthogonality principle is a necessary and sufficient condition for the optimality of a bayesian estimator loosely stated the orthogonality principle says that the error vector of the optimal estimator in a mean square error sense is orthogonal to any possible estimator the orthogonality principle is most commonly stated for linear estimators but more general formulations are possible since the principle is a necessary and sufficient condition for optimality it can be used to find the minimum mean square error estimator
dyslexia is a complex lifelong disorder involving difficulty in learning to read or interpret words letters and other symbols dyslexia does not affect general intelligence but is often co diagnosed with adhd there are at least three sub types of dyslexia that have been recognized by researchers orthographic or surface dyslexia phonological dyslexia and mixed dyslexia where individuals exhibit symptoms of both orthographic and phonological dyslexia studies have shown that dyslexia is genetic and can be passed down through families but it is important to note that although a genetic disorder there is no specific locus in the brain for reading and writing the human brain does have language centers for spoken and gestural communication but written language is a cultural artifact and a very complex one requiring brain regions designed to recognize and interpret written symbols as representations of language in rapid synchronization the complexity of the system and the lack of genetic predisposition for it is one possible explanation for the difficulty in acquiring and understanding written language furthermore recent evidence has found that there are certain genes responsible for causing dyslexia research also suggests a clear genetic basis for developmental dyslexia with abnormalities in certain language areas of the brain however there is also evidence that orthography the correspondence between the language s phonemes sound units and its graphemes characters symbols letters plays a significant role in the type and frequency of dyslexia s manifestations some psycholinguists believe that the complexity of a language ’ s orthography whether it has a high phoneme grapheme correspondence or an irregular correspondence in which sounds don ’ t clearly map to symbols affects the severity and occurrence of dyslexia postulating that a more regular system would reduce the number of cases of dyslexia and or the severity of symptoms current psycholinguistic models of dyslexia are largely developed on the basis of alphabetic writing systems such as english but the amount of research on some logographic orthographies chinese in particular is also fairly significant unfortunately little research has been done on syllabic writing systems and cross linguistic studies of the acquired dyslexia and dysgraphias are scarce
orthokeratosis is hyperkeratosis without parakeratosis no nucleus is seen in the cells from ancient greek ortho keratos keratin horn osis condition it is seen in linear verrucous epidermal naevus in alternating band with parakeratosis
orthorexia nervosa ˌɔːrθəˈrɛksiə nɜːrˈvoʊsə also known as orthorexia is a proposed distinct eating disorder characterized by extreme or excessive preoccupation with eating food believed to be healthy the term was introduced in 1997 by american physician steven bratman m d who suggests that in some susceptible people dietary restrictions intended to promote health may paradoxically lead to unhealthy consequences such as social isolation anxiety loss of ability to eat in a natural intuitive manner reduced interest in the full range of other healthy human activities and in rare cases severe malnutrition or even death in 2009 ursula philpot chair of the british dietetic association and senior lecturer at leeds metropolitan university described people with orthorexia nervosa to the guardian as being solely concerned with the quality of the food they put in their bodies refining and restricting their diets according to their personal understanding of which foods are truly pure this differs from other eating disorders such as anorexia nervosa and bulimia nervosa whereby people focus on the quantity of food eaten orthorexia nervosa is not recognized as an eating disorder by the american psychiatric association and is not mentioned as an official diagnosis in the widely used diagnostic and statistical manual of mental disorders dsm or any other such authoritative source
orthostatic proteinuria synonyms orthostatic albuminuria postural proteinuria is a benign condition a change in renal hemodynamics which in some otherwise normal individuals causes protein mostly albumin to appear in urine when they are in the standing position urine formed when these individuals are lying down is protein free there is normal urinary protein excretion during the night but increased excretion during the day associated with activity and upright posture total urinary protein excretion may be increased but levels above 1 g per 24 hours are more likely to be associated with underlying renal disease the exact cause of orthostatic proteinuria is not known
orthostatic headache is a medical condition in which a person develops a headache while vertical and the headache is relieved when horizontal previously it was often misdiagnosed as different primary headache disorders such as migraine or tension headaches increasing awareness of the symptom and its causes has prevented delayed or missed diagnosis
orthostatic hypertension or postural hypertension is a medical condition consisting of a sudden increase in blood pressure when a person stands up orthostatic hypertension is diagnosed by a rise in systolic blood pressure of 20 mmhg or more when standing orthostatic diastolic hypertension is a condition in which the diastolic raises to 98 mmhg or over in response to standing however this definition currently lacks clear medical consensus and is thus subject to change orthostatic hypertension involving the systolic is known as systolic orthostatic hypertension if affecting an individual s ability to remain upright orthostatic hypertension is viewed as a form of orthostatic intolerance the body s inability to regulate the blood pressure can be a type of dysautonomia baroreflex and autonomic pathways normally ensure that blood pressure is maintained despite various stimuli including postural change the precise mechanism of orthostatic hypertension remains unclear but it is thought that alpha adrenergic activity may be the predominant pathophysiologic mechanism of orthostatic hypertension in elderly hypertensive patients other mechanisms are proposed for other different groups of individuals with this disorder a prevalence of 1 1 was found in a large population study the risk of orthostatic hypertension has been found to increase with age with it being found in 16 3 of older hypertensive patients
orthostatic hypotension also known as postural hypotension or shortened to orthostasis and colloquially called head rush occurs when a person s blood pressure falls when suddenly standing up from a lying or sitting position it is defined as a fall in systolic blood pressure of at least 20 mm hg or diastolic blood pressure of at least 10 mm hg when a person assumes a standing position it occurs predominantly by delayed constriction of the lower body blood vessels which is normally required to maintain an adequate blood pressure when changing position to standing as a result blood pools in the blood vessels of the legs for a longer period and less is returned to the heart thereby leading to a reduced cardiac output mild orthostatic hypotension is common and can occur briefly in anyone although it is prevalent in particular among the elderly and those with known low blood pressure severe drops in blood pressure can lead to fainting with a possibility of injury there are numerous possible causes for orthostatic hypotension such as certain medications e g alpha blockers autonomic neuropathy decreased blood volume and age related blood vessel stiffness apart from addressing the underlying cause orthostatic hypotension may be treated with a recommendation to increase salt and water intake to increase the blood volume wearing compression stockings and sometimes medication fludrocortisone midodrine or others
orthostatic intolerance oi is the development of symptoms when standing upright which are relieved when reclining there are many types of orthostatic intolerance oi can be a subcategory of dysautonomia a disorder of the autonomic nervous system occurring when an individual stands up there is a substantial overlap between syndromes of orthostatic intolerance on the one hand and either chronic fatigue syndrome cfs or fibromyalgia fm on the other it affects more women than men female to male ratio is at least 4 1 usually under the age of 35 orthostatic intolerance occurs in humans because standing upright is a fundamental stressor and requires rapid and effective circulatory and neurologic compensations to maintain blood pressure cerebral blood flow and consciousness when a human stands approximately 750 ml of thoracic blood is abruptly translocated downward people who suffer from oi lack the basic mechanisms to compensate for this deficit changes in heart rate blood pressure and cerebral blood flow that produce oi may be caused by abnormalities in the interactions between blood volume control the cardiovascular system the nervous system and circulation control systems
orthostatic purpura also known as stasis purpura is a skin condition that results from prolonged standing or even sitting with the legs lowered as in a bus airplane or train which produced edema and a purpuric eruption on the lower extremities
ortner s syndrome is a rare cardiovocal syndrome and refers to recurrent laryngeal nerve palsy from cardiovascular disease it was first described by norbert ortner 1865 – 1935 an austrian physician in 1897 the most common historical cause is a dilated left atrium due to mitral stenosis but other causes including pulmonary hypertension thoracic aortic aneurysms an enlarged pulmonary artery and aberrant subclavian artery syndrome have been reported compressing the nerve dysphagia caused by a similar mechanism is referred to as dysphagia aortica or in the case of subclavian artery aberrancy as dysphagia lusoria due to compression of recurrent laryngeal nerve it can cause the hoarseness of the voice which is also one of the sign of the mitral stenosis a second ortner s syndrome ortner s syndrome ii refers to abdominal angina
oríkì or praise poetry is a cultural phenomenon in yoruba speakers of west africa
in a cellular automaton an oscillator is a pattern that returns to its original state in the same orientation and position after a finite number of generations thus the evolution of such a pattern repeats itself indefinitely depending on context the term may also include spaceships as well the smallest number of generations it takes before the pattern returns to its initial condition is called the period of the oscillator an oscillator with a period of 1 is usually called a still life as such a pattern never changes sometimes still lifes are not taken to be oscillators another common stipulation is that an oscillator must be finite
in physics an oscillon is a soliton like phenomenon that occurs in granular and other dissipative media oscillons in granular media result from vertically vibrating a plate with a layer of uniform particles placed freely on top when the sinusoidal vibrations are of the correct amplitude and frequency and the layer of sufficient thickness a localized wave referred to as an oscillon can be formed by locally disturbing the particles this meta stable state will remain for a long time many hundreds of thousands of oscillations in the absence of further perturbation an oscillon changes form with each collision of the grain layer and the plate switching between a peak that projects above the grain layer to a crater like depression with a small rim this self sustaining state was named by analogy with the soliton which is a localized wave that maintains its integrity as it moves whereas solitons occur as travelling waves in a fluid or as electromagnetic waves in a waveguide oscillons may be stationary oscillons of opposite phase will attract over short distances and form bonded pairs oscillons of like phase repel oscillons have been observed forming molecule like structures and long chains in comparison solitons do not form bound states stable interacting localized waves with subharmonic response were discovered and named oscillons at the university of texas at austin solitary bursts had been reported earlier in a quasi two dimensional grain layer at the university of paris but these transient events were unstable and no bonding interaction or subharmonic response was reported the cause of this phenomenon is currently under debate the most likely connection is with the mathematical theory of chaos and may give insights into the way patterns in sand form the experimental procedure is similar to that used to form chladni figures of sand on a vibrating plate researchers realized that these figures say more about the vibrational modes of the plate than the response of the sand and created an experimental set up that minimized outside effects using a shallow layer of brass balls in a vacuum and a rigid plate when they vibrated the plate at critical amplitude they found that the balls formed a localized vibrating structure when perturbed which lasted indefinitely oscillons have also been experimentally observed in thin parametrically vibrated layers of viscous fluid and colloidal suspensions oscillons have been associated with faraday waves because they require similar resonance conditions nonlinear electrostatic oscillations on a plasma boundary can also appear in the form of oscillons this was discovered in 1989
oscillopsia is a visual disturbance in which objects in the visual field appear to oscillate the severity of the effect may range from a mild blurring to rapid and periodic jumping oscillopsia is an incapacitating condition experienced by many patients with neurological disorders it may be the result of ocular instability occurring after the oculomotor system is affected no longer holding images steady on the retina a change in the magnitude of the vestibulo ocular reflex due to vestibular disease can also lead to oscillopsia during rapid head movements oscillopsia may also be caused by involuntary eye movements such as nystagmus or impaired coordination in the visual cortex especially due to toxins and is one of the symptoms of superior canal dehiscence syndrome sufferers may experience dizziness and nausea oscillopsia can also be used as a quantitative test to document aminoglycoside toxicity permanent oscillopsia can arise from an impairment of the ocular system that serves to maintain ocular stability paroxysmal oscillopsia can be due to an abnormal hyperactivity in the peripheral ocular or vestibular system
osgood – schlatter disease osd also known as apophysitis of the tibial tubercle or lannelongue s disease is an inflammation of the patellar ligament at the tibial tuberosity it is characterized by a painful bump just below the knee and is most often seen in young adolescents risk factors include overuse especially in sports involving running jumping and quick changes of direction and adolescent growth spurts the condition is named after robert bayley osgood 1873 – 1956 an american orthopedic surgeon and carl b schlatter 1864 – 1934 a swiss surgeon who described the condition independently in 1903
in tableware the osier pattern is a moulded basket weave pattern in delicate relief used round the borders of porcelain plates and other pieces of flatware it originated in germany in the 1730 s on meissen porcelain and was later often imitated by other producers it is presumed to have been devised by johann joachim kaendler the celebrated head modeller at meissen the name comes from salix viminalis or the common osier ozier in german a eurasian species of willow whose thin flexible shoots or withies were and are much used for various types of wickerwork usually encouraged by coppicing the plants such relief backgrounds were a speciality of meissen under kändler as in the dulong border from 1743 with a rather neoclassical plant scroll pattern and most spectacular of all the decoration of the famous swan service where each plate or other piece of flatware has a delicate background with radiating bands based on a scallop shell against which there is in the central well a pair of swans on the water amid bullrushes and a crane in the air descending to join another on the left the standing crane grasps a fish in his beak and the head of another fish can be seen in the water beneath the swan on the right in fact meissen used three versions of the osier borders with several minor variations between different moulds the first type produced from about 1732 and widely used in a dinner service for count alexander joseph sulkowski of about 1735 is called the ordinar ozier ordinary osier or sulkowski type it has small groups of shoots diagonal to the edge of the plate forming squares with the adjacent groups at right angles these are all set between straight vertical bands at regular intervals the inner and outer boundaries of the osier decoration may be marked by striated bands also imitating woven basketwork not long after a version was introduced with finer shoots all going in the same direction parallel with the edge of the plate and not always having the vertical strips which as before are straight after the final version was introduced in 1742 this second one was known as the altozier or old ozier and the third one as the neuozier or new osier the neuozier pattern was a more rococo version with spiral ribs in this type the vertical strips or ribs curve into a sort of s shape are given more emphasis and often come into the central well of the plate projecting beyond the basket weave which may cover only about half of the raised border of the plate the inner boundary of the decoration is marked by a raised ridge both old and new types continued to be produced up to the present day the central well of the plate is left plain except in the new type and many larger pieces that are not flat cups pots and tureens for example lack the relief pattern lao ricebasket the sort of weave imitated in the first sulkowski type wicker fence with the sort of weave imitated in the old osier pattern frankenthal porcelain imitation of the old osier pattern with minimal vertical bands
osmeña pearls are items of jewelry made by polishing the shell of a nautilus it has an iridescent color typically consisting of blue pink and purple hues
osmol gap in medical science is the difference between measured serum osmolality and calculated serum osmolality
osmotic blistering is a chemical phenomenon where two substances attempt to reach equilibrium through a semi permeable membrane
osmotic pressure is the minimum pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane it is also defined as the measure of the tendency of a solution to take in water by osmosis potential osmotic pressure is the maximum osmotic pressure that could develop in a solution if it were separated from distilled water by a selectively permeable membrane the phenomenon of osmosis arises from the propensity of a pure solvent to move through a semi permeable membrane and into a solution containing a solute to which the membrane is impermeable this process is of vital importance in biology as the cell s membrane is semipermeable
osselet is arthritis in the fetlock joint of a horse
an ossifying fibromyxoid tumour is a type of myxoma it presents in the extremities more frequently than the trunk it is derived from mesenchyme appearance in the head and neck is rare but has been reported their malignancy has been characterized as intermediate
osteitis is a general term for inflammation of bone more specifically it can refer to one of the following conditions infectious osteitis mainly bacterial osteitis alveolar osteitis or dry socket condensing osteitis or osteitis condensans osteitis deformans or paget s disease of bone osteitis fibrosa cystica or osteitis fibrosa or von recklinghausen s disease of bone osteitis pubis radiation osteitis osteitis condensans ilii panosteitis a long bone condition in large breed dogs in horses pedal osteitis is frequently confused with laminitis
osteitis fibrosa cystica ˌɒstiːˈaɪtᵻs faɪˈbroʊsə ˈsɪstᵻkə abbreviated ofc also known as osteitis fibrosa osteodystrophia fibrosa and von recklinghausen s disease of bone not to be confused with von recklinghausen s disease neurofibromatosis type i is a skeletal disorder caused by hyperparathyroidism which is a surplus of parathyroid hormone from over active parathyroid glands this surplus stimulates the activity of osteoclasts cells that break down bone in a process known as osteoclastic bone resorption the hyperparathyroidism can be triggered by a parathyroid adenoma hereditary factors parathyroid carcinoma or renal osteodystrophy osteoclastic bone resorption releases minerals including calcium from the bone into the bloodstream in addition to elevated blood calcium levels over activity of this process results in a loss of bone mass a weakening of the bones as their calcified supporting structures are replaced with fibrous tissue peritrabecular fibrosis and the formation of cyst like brown tumors in and around the bone the symptoms of the disease are the consequences of both the general softening of the bones and the excess calcium in the blood and include bone fractures kidney stones nausea moth eaten appearance in the bones appetite loss and weight loss first described in the nineteenth century ofc is currently detected through a combination of blood testing x rays and tissue sampling before 1950 around half of those diagnosed with hyperparathyroidism in the united states saw it progress to ofc but with early identification techniques and improved treatment methods instances of ofc in developed countries are increasingly rare where treatment is required it normally involves addressing the underlying hyperparathyroidism before commencing long term treatment for ofc — depending on its cause and severity this can range from hydration and exercise to surgical intervention
causes pregnancy childbirth gynecologic surgery urologic surgery athletic activities e g running football soccer ice hockey tennis major trauma repeated minor trauma rheumatological disorders unknown etiologies in the pre antibiotic era osteitis pubis was an occasional complication of pelvic surgery and in particular of retropubic prostatectomy overload or training errors exercising on hard surfaces like concrete exercising on uneven ground beginning an exercise program after a long lay off period increasing exercise intensity or duration too quickly exercising in worn out or ill fitting shoes biomechanical inefficiencies faulty foot and body mechanics and gait disturbances poor running or walking mechanics tight stiff muscles in the hips groin and buttocks muscular imbalances leg length differences
osteoarthritis oa is a type of joint disease that results from breakdown of joint cartilage and underlying bone the most common symptoms are joint pain and stiffness initially symptoms may occur only following exercise but over time may become constant other symptoms may include joint swelling decreased range of motion and when the back is affected weakness or numbness of the arms and legs the most commonly involved joints are those near the ends of the fingers at the base of the thumb neck lower back knee and hips joints on one side of the body are often more affected than those on the other usually the symptoms come on over years it can affect work and normal daily activities unlike other types of arthritis only the joints are typically affected causes include previous joint injury abnormal joint or limb development and inherited factors risk is greater in those who are overweight have one leg of a different length and have jobs that result in high levels of joint stress osteoarthritis is believed to be caused by mechanical stress on the joint and low grade inflammatory processes it develops as cartilage is lost and the underlying bone becomes affected as pain may make it difficult to exercise muscle loss may occur diagnosis is typically based on signs and symptoms with medical imaging and other tests occasionally used to either support or rule out other problems in contrast to rheumatoid arthritis which is primarily an inflammatory condition in oa the joints do not typically become hot or red treatment includes exercise efforts to decrease joint stress support groups and pain medications efforts to decrease joint stress include resting and the use of a cane weight loss may help in those who are overweight pain medications may include paracetamol acetaminophen as well as nsaids such as naproxen or ibuprofen long term opioid use is generally discouraged due to lack of information on benefits as well as risks of addiction and other side effects if pain interferes with normal life despite other treatments joint replacement surgery may help an artificial joint typically lasts 10 to 15 years oa is the most common form of arthritis with disease of the knee and hip affecting about 3 8 of people as of 2010 among those over 60 years old about 10 of males and 18 of females are affected it is the cause of about 2 of years lived with disability in australia about 1 9 million people are affected and in the united states over 30 million people are affected it becomes more common in both sexes as people become older
osteoblastoma is an uncommon osteoid tissue forming primary neoplasm of the bone it has clinical and histologic manifestations similar to those of osteoid osteoma therefore some consider the two tumors to be variants of the same disease with osteoblastoma representing a giant osteoid osteoma however an aggressive type of osteoblastoma has been recognized making the relationship less clear although similar to osteoid osteoma it is larger between 2 and 6 cm
osteochondritis is a painful type of osteochondrosis where the cartilage or bone in a joint is inflamed it often refers to osteochondritis dissecans sometimes spelt dessecans and abbreviated ocd the term dissecans refers to the creation of a flap of cartilage that further dissects away from its underlying subchondral attachments dissecans the other recognized types of osteochondritis are osteochondritis deformans juvenilis osteochondritis of the capitular head of the epiphysis of the femur and osteochondritis deformans juvenilis dorsi osteochondrosis of the spinal vertebrae also known as scheuermann s disease osteochondritis and especially osteochondritis dissecans can manifest in animals as a primary cause of elbow dysplasia a chronic condition in some species and breeds
osteochondritis dissecans ocd or od is a joint disorder in which cracks form in the articular cartilage and the underlying subchondral bone ocd usually causes pain and swelling of the affected joint which catches and locks during movement physical examination typically reveals an effusion tenderness and a crackling sound with joint movement ocd is caused by blood deprivation in the subchondral bone this loss of blood flow causes the subchondral bone to die in a process called avascular necrosis the bone is then reabsorbed by the body leaving the articular cartilage it supported prone to damage the result is fragmentation dissection of both cartilage and bone and the free movement of these bone and cartilage fragments within the joint space causing pain and further damage ocd can be difficult to diagnose because these symptoms are found with other diseases however the disease can be confirmed by x rays computed tomography ct or magnetic resonance imaging mri scans non surgical treatment is rarely an option as the ability for articular cartilage to heal is limited as a result even moderate cases require some form of surgery when possible non operative forms of management such as protected reduced or non weight bearing and immobilization are used surgical treatment includes arthroscopic drilling of intact lesions securing of cartilage flap lesions with pins or screws drilling and replacement of cartilage plugs stem cell transplantation and joint replacement after surgery rehabilitation is usually a two stage process of immobilization and physical therapy most rehabilitation programs combine efforts to protection the joint with muscle strengthening and range of motion during the immobilization period isometric exercises such as straight leg raises are commonly used to restore muscle loss without disturbing the cartilage of the affected joint once the immobilization period has ended physical therapy involves continuous passive motion cpm and or low impact activities such as walking or swimming ocd occurs in 15 to 30 people per 100 000 in the general population each year although rare it is an important cause of joint pain in physically active adolescents because their bones are still growing adolescents are more likely than adults to recover from ocd recovery in adolescents can be attributed to the bone s ability to repair damaged or dead bone tissue and cartilage in a process called bone remodeling while ocd may affect any joint the knee tends to be the most commonly affected and constitutes 75 of all cases franz könig coined the term osteochondritis dissecans in 1887 describing it as an inflammation of the bone – cartilage interface many other conditions were once confused with ocd when attempting to describe how the disease affected the joint including osteochondral fracture osteonecrosis accessory ossification center osteochondrosis and hereditary epiphyseal dysplasia some authors have used the terms osteochondrosis dissecans and osteochondral fragments as synonyms for ocd
osteochondrodysplasia or skeletal dysplasia is a general term for a disorder of the development dysplasia of bone osteo and cartilage chondro osteochondrodysplasias are rare diseases about 1 in 5 000 babies are born with some type of skeletal dysplasia
osteochondromas or osteocartilaginous exostoses are the most common benign tumors of the bones the tumors take the form of cartilage capped bony projections or outgrowth on the surface of bones exostoses it is characterized as a type of overgrowth that can occur in any bone where cartilage forms bone tumors most commonly affect long bones in the leg pelvis or scapula shoulder blade development of osteochondromas take place during skeletal growth between the ages of 13 and 15 and ceases when the growth plate fuses at puberty they arise within the first three decades of life affecting children and adolescents osteochondromas occur in 3 of the general population and represent 35 of all benign tumors and 8 of all bone tumors majority of these tumors are solitary non hereditary lesions and approximately 15 of osteochondromas occur as hereditary multiple osteochondromas hmos they can occur as a solitary lesion solitary osteochondroma or multiple lesions within the context of the same bone multiple osteochondroma osteochondromas do not result from injury and the exact cause remains unknown recent research has indicated that multiple osteochondromas is an autosomal dominant inherited disease germ line mutations in ext 1 and ext 2 genes located on chromosomes 8 and 11 have been associated with the cause of the disease the treatment choice for osteochondroma is surgical removal of solitary lesion or partial excision of the outgrowth when symptoms cause motion limitations or nerve and blood vessel impingements
osteochondromatosis is a condition involving a proliferation of osteochondromas types include hereditary multiple exostoses synovial osteochondromatosis
osteochondropathy refers to a disease pathy of the bone and cartilage however it is more common to refer to these conditions as one of the following chondropathy disease of the cartilage a bone disease is also called an osteopathy but because the term osteopathy is often used to describe a healthcare approach use of the term can cause some confusion
osteochondrosis is a family of orthopedic diseases of the joint that occur in children and adolescents and in rapidly growing animals particularly pigs horses dogs and broiler chickens they are characterized by interruption of the blood supply of a bone in particular to the epiphysis followed by localized bony necrosis and later regrowth of the bone this disorder is defined as a focal disturbance of endochondral ossification and is regarded as having a multifactorial etiology so no one thing accounts for all aspects of this disease
osteoderms are bony deposits forming scales plates or other structures in the dermal layers of the skin osteoderms are found in many groups of extant and extinct reptiles and amphibians including lizards crocodilians frogs temnospondyls various groups of dinosaurs most notably ankylosaurs and stegosaurians phytosaurs aetosaurs placodonts and hupehsuchians marine reptiles with possible ichthyosaur affinities osteoderms are uncommon in mammals but do occur in many xenarthrans glyptodonts armadillos ground sloths osteoderms have clearly evolved independently in many different lineages and these varied structures should be thought of as anatomical analogues not homologues and do not necessarily indicate monophyly in many cases osteoderms may function as defensive armor the osteoderms of modern crocodilians are heavily vascularized and can function as both armor and as heat exchangers allowing these large reptiles to rapidly raise or lower their temperature another function is to neutralize acidosis caused by being submerged under water for longer periods of time and leading to the accumulation of carbon dioxide in the blood the calcium and magnesium in the dermal bone will release alkaline ions into the bloodstream acting as a buffer against acidification of the body fluid
osteofibrous dysplasia also known as ossifying fibroma is a rare benign non neoplastic condition with no known cause it is considered a fibrovascular defect campanacci described this condition in two leg bones the tibia and fibula and coined the term this condition should be differentiated from nonossifying fibroma and fibrous dysplasia of bone
osteogenesis imperfecta oi is a group of genetic disorders that mainly affect the bones it results in bones that break easily the severity may be mild to severe other symptoms may include a blue tinge to the white s of the eye short height loose joints hearing loss breathing problems and problems with the teeth the underlying mechanism is usually a problem with connective tissue due to a lack of type i collagen this occurs in more than 90 of cases due to mutations in the col 1 a 1 or col 1 a 2 genes these genetic problems are often inherited from a person s parents in an autosomal dominant manner or occur via a new mutation there are eight types with type i being the least severe and type ii the most severe diagnosis is often based on symptoms and may be confirmed by collagen or dna testing there is no cure maintaining a health healthy lifestyle by exercising and avoiding smoking can help prevent fractures treatment may include care of broken bones pain medication physical therapy braces or wheelchairs and surgery a type of surgery that puts metal rods through long bones maybe done to strengthen them tentative evidence supports the use of medications of the bisphosphonate type oi affects about one in 15 000 people outcomes depend on the type of disease most people however have good outcomes the condition has been described since ancient history the term osteogenesis imperfecta came into use in 1895 and means imperfect bone formation
an osteoid osteoma is a benign bone tumor that arises from osteoblasts and was originally thought to be a smaller version of an osteoblastoma osteoid osteomas tend to be less than 1 5 cm in size the tumor can be in any bone in the body but are most common in long bones such as the femur and tibia they account for 10 to 12 percent of all benign bone tumors osteoid osteomas may occur at any age and are most common in patients between the ages of 4 and 25 years old males are affected approximately three times more commonly than females
osteolathyrism is a collagen cross linking deficiency brought on by dietary over reliance on the seeds of lathyrus sativus or grass pea a legume often grown as a famine crop in asia and east africa other members of the genus are also known to cause the disease including l sylvestris l cicera and l clymenum l sativus grows well under famine conditions often severe drought where it is cultivated the condition results in damage to bone and mesenchymal connective tissues it is seen in people in combination with neurolathyrism and angiolathyrism in areas where famine demands reliance on a crop with known detrimental effects it occurs in cattle and horses with diets overreliant upon the grass pea osteolathyrism is caused by a variety of osteolathyrogenic compounds specifically excitatory amino compounds the most widely studied of these compounds is beta aminopropionitrile bapn which exerts its deleterious effect by an unknown yet potently irreversible mechanism other instigators are ureides semicarbazides and thiosemicarbazides which are believed to chelate the prosthetic cu ii bipyridine cofactor complex in the enzyme lysyl oxidase
osteolipochondroma osteo bone lipos fat chondros cartilage oma tumor is a cartilaginous tumor containing fatty and bony tissue
osteolysis is an active resorption of bone matrix by osteoclasts and can be interpreted as the reverse of ossification although osteoclasts are active during the natural formation of healthy bone the term osteolysis specifically refers to a pathological process osteolysis often occurs in the proximity of a prosthesis that causes either an immunological response or changes in the bone s structural load osteolysis may also be caused by pathologies like bone tumors cysts or chronic inflammation
an osteoma plural osteomata is a new piece of bone usually growing on another piece of bone typically the skull it is a benign tumor when the bone tumor grows on other bone it is known as homoplastic osteoma when it grows on other tissue it is called heteroplastic osteoma osteoma represents the most common benign neoplasm of the nose and paranasal sinuses the cause of osteomata is uncertain but commonly accepted theories propose embryologic traumatic or infectious causes osteomata are also found in gardner s syndrome larger craniofacial osteomata may cause facial pain headache and infection due to obstructed nasofrontal ducts often craniofacial osteoma presents itself through ocular signs and symptoms such as proptosis
osteoma cutis is a cutaneous condition characterized by the presence of bone within the skin in the absence of a preexisting or associated lesion
osteomalacia is the softening of the bones caused by impaired bone metabolism primarily due to inadequate levels of available phosphate calcium and vitamin d or because of resorption of calcium the impairment of bone metabolism causes inadequate bone remineralization osteomalacia in children is known as rickets and because of this use of the term osteomalacia is often restricted to the milder adult form of the disease signs and symptoms can include diffuse body pains muscle weakness and fragility of the bones the most common cause of osteomalacia is a deficiency of vitamin d which is normally derived from sunlight exposure and to a lesser extent from the diet the most specific screening test for vitamin d deficiency in otherwise healthy individuals is a serum 25 oh d level less common causes of osteomalacia can include hereditary deficiencies of vitamin d or phosphate which would typically be identified in childhood or malignancy measures to prevent and treat osteomalacia usually revolve around intake of vitamin d and calcium supplements vitamin d should always be administered in conjunction with calcium supplementation since most of the consequences of vitamin d deficiency are a result of impaired mineral ion homeostasis nursing home residents and the homebound elderly population are at particular risk for vitamin d deficiency as these populations typically receive little sun exposure in addition both the efficiency of vitamin d synthesis in the skin and the absorption of vitamin d from the intestine decline with age thus further increasing the risk in these populations other groups at risk include individuals with malabsorption secondary to gastrointestinal bypass surgery or celiac disease and individuals who immigrate from warm climates to cold climates especially women who wear traditional veils or dresses that prevent sun exposure
osteomyelitis om is infection and inflammation of the bone and bone marrow it can be usefully subclassified on the basis of the causative organism pyogenic bacteria or mycobacteria and the route duration and anatomic location of the infection osteomyelitis usually begins as an acute infection but it may evolve into a chronic condition the word is from greek words ὀστέον osteon meaning bone μυελό myelo meaning marrow and ῖτις itis meaning inflammation
osteomyelitis of the jaws is osteomyelitis which is infection and inflammation of the bone marrow sometimes abbreviated to om which occurs in the bones of the jaws i e maxilla or the mandible historically osteomyelitis of the jaws was a common complication of odontogenic infection infections of the teeth before the antibiotic era it was frequently a fatal condition former and colloquial names include osteonecrosis of the jaws onj cavitations dry or wet socket and nico neuralgia inducing cavitational osteonecrosis the current more correct term osteomyelitis of the jaws differentiates the condition from the relatively recent and better known iatrogenic phenomenon of bisphosphonate caused osteonecrosis of the jaws the latter is found primarily in post menopausal women given bisphosphonate drugs usually against osteoporosis
osteonecrosis of the jaw onj is a severe bone disease osteonecrosis that affects the jaws the maxilla and the mandible various forms of onj have been described over the last 160 years and a number of causes have been suggested in the literature osteonecrosis of the jaw associated with bisphosphonate therapy which is required by some cancer treatment regimens has been identified and defined as a pathological entity bisphosphonate associated osteonecrosis of the jaw since 2003 the possible risk from lower oral doses of bisphosphonates taken by patients to prevent or treat osteoporosis remains uncertain treatment options have been explored however severe cases of onj still require surgical removal of the affected bone a thorough history and assessment of pre existing systemic problems and possible sites of dental infection are required to help prevent the condition especially if bisphosphonate therapy is considered
osteopenia is a condition in which bone mineral density is lower than normal it is considered by many doctors to be a precursor to osteoporosis however not every person diagnosed with osteopenia will develop osteoporosis more specifically osteopenia is defined as a bone mineral density t score between − 1 0 and − 2 5
osteopetrosis literally stone bone also known as marble bone disease and albers schönberg disease is an extremely rare inherited disorder whereby the bones harden becoming denser in contrast to more prevalent conditions like osteoporosis in which the bones become less dense and more brittle or osteomalacia in which the bones soften osteopetrosis can cause bones to dissolve and break it can cause osteosclerosis the cause of the disease is understood to be malfunctioning osteoclasts radiological findings will show a bone in bone appearance
osteophytes commonly referred to as bone spurs are bony projections that form along joint margins they should not be confused with enthesophytes which are bony projections that form at the attachment of a tendon or ligament
osteopoikilosis is a benign autosomal dominant sclerosing dysplasia of bone characterized by the presence of numerous bone islands in the skeleton
osteoporosis is a disease where decreased bone strength increases the risk of a broken bone it is the most common reason for a broken bone among the elderly bones that commonly break include the back bones the bones of the forearm and the hip until a broken bone occurs there are typically no symptoms bones may weaken to such a degree that a break may occur with minor stress or spontaneously chronic pain and a decreased ability to carry out normal activities may occur following a broken bone osteoporosis may be due to lower than normal peak bone mass and greater than normal bone loss bone loss increases after menopause due to lower levels of estrogen osteoporosis may also occur due to a number of diseases or treatments including alcoholism anorexia hyperthyroidism surgical removal of the ovaries and kidney disease certain medications increase the rate of bone loss including some antiseizure medications chemotherapy proton pump inhibitors selective serotonin reuptake inhibitors and steroids not enough exercise and smoking are also risk factors osteoporosis is defined as a bone density of 2 5 standard deviations below that of a young adult this is typically measured by dual energy x ray absorptiometry at the hip prevention of osteoporosis includes a proper diet during childhood and efforts to avoid medications that cause the condition efforts to prevent broken bones in those with osteoporosis include a good diet exercise and fall prevention lifestyle changes such as stopping smoking and not drinking alcohol may help medication of the bisphosphonate type are useful in those with previous broken bones due to osteoporosis in those with osteoporosis but no previous broken bones they are less effective a number of other medications may also be useful osteoporosis becomes more common with age about 15 of white people in their 50 s and 70 of those over 80 are affected it is more common in women than men in the developed world depending on the method of diagnosis 2 to 8 of males and 9 to 38 of females are affected rates of disease in the developing world are unclear about 22 million women and 5 5 million men in the european union had osteoporosis in 2010 in the united states in 2010 about eight million women and one to two million men had osteoporosis white and asian people are at greater risk the word osteoporosis is from the greek terms for porous bones
osteoporotic bone marrow defect is a condition which may be found in the body of the mandible it is usually painless and found during routine radiographs it appears as a poorly defined radiolucency dark area where there was a previous history of an extraction of a tooth it may resemble a metastatic disease it is a localized increase of hematopoietic bone marrow that creates a radiolucent radiographic defect they occur more commonly in women in the midyears and show a predilection for the molar region of the mandible they are especially common in extraction sites scattered trabeculae may extend short distances into the defect or in some instances through it giving the defect a fairly characteristic appearance naturally there are no clinical symptoms
osteoradionecrosis is a possible complication following radiotherapy where an area of bone does not heal from irradiation irradiation of bones causes damage to osteocytes and impairs the blood supply the affected hard tissues become hypovascular reduced number of blood vessels hypocellular reduced number of cells and hypoxic low levels of oxygen osteoradionecrosis usually occurs in the mandible and causes chronic pain and surface ulceration prevention of osteradionecrosis is part of the reason all teeth of questionable prognosis are removed before the start of a course of radiotherapy
an osteosarcoma is a cancerous tumor in a bone specifically it is an aggressive malignant neoplasm that arises from primitive transformed cells of mesenchymal origin and thus a sarcoma and that exhibits osteoblastic differentiation and produces malignant osteoid osteosarcoma is the most common histological form of primary bone cancer it is most prevalent in children and young adults
osteosclerosis is a type of osteopetrosis that involves abnormal hardening of bone and an elevation in bone density it can be a pathology normally detected on a radiograph as an area of increased opacity that is where more mineral is present in the bone to absorb or deflect the x ray beam localized osteosclerosis can be caused by injuries that compress the bone by osteoarthritis and osteoma it is associated with prostate cancer metastasis melorheostosis osteopetrosis osteopoikilosis chronic idiopathic myelofibrosis skeletal fluorosis schnitzler syndrome monoclonal igm kappa cryoglobulinemia it can also be associated with hepatitis c in the animal kingdom there also exists a non pathological form of osteosclerosis resulting in unusually solid bone structure with little to no marrow it is often seen in aquatic vertebrates especially those living in shallow waters providing ballast as an adaptation for an aquatic lifestyle it makes bones heavier but also more fragile in those animal groups osteosclerosis often occurs together with bone thickening pachyostosis this joint occurrence is called pachyosteosclerosis sclerosis of the bones of the thoracic spine due to prostate cancer metastases ct image sclerosis of the bones of the thoracic spine due to prostate cancer metastases ct image
the ostium primum atrial septal defect also known as an endocardial cushion defect is a defect in the atrial septum at the level of the tricuspid and mitral valves this is sometimes known as an endocardial cushion defect because it often involves the endocardial cushion which is the portion of the heart where the atrial septum meets the ventricular septum and the mitral valve meets the tricuspid valve endocardial cushion defects are associated with abnormalities of the atrioventricular valves the mitral valve and the tricuspid valve these include the cleft mitral valve and the single atrioventricular valve a single large deformed valve that flows into both the right ventricle and the left ventricle endocardial cushion defects are the most common congenital heart defect that is associated with down s syndrome
in applied mathematics the ostrogradsky instability is a consequence of a theorem of mikhail ostrogradsky in classical mechanics according to which a non degenerate lagrangian dependent on time derivatives of higher than the first corresponds to a linearly unstable hamiltonian associated with the lagrangian via a legendre transform the ostrogradsky instability has been proposed as an explanation as to why no differential equations of higher order than two appear to describe physical phenomena
dissolution of small crystals or sol particles and the redeposition of the dissolved species on the surfaces of larger crystals or sol particles was first described by wilhelm ostwald in 1896 ostwald ripening is generally found in water in oil emulsions while flocculation is found in oil in water emulsions
other specified feeding or eating disorder or osfed is the dsm 5 category that replaces the category formerly called eating disorder not otherwise specified ednos in dsm iv and that captures feeding disorders and eating disorders of clinical severity that do not meet diagnostic criteria for anorexia nervosa an bulimia nervosa bn binge eating disorder bed avoidant restrictive food intake disorder arfid pica or rumination disorder osfed includes five examples atypical an bn of low frequency and or limited duration bed of low frequency and or limited duration purging disorder and night eating syndrome nes
an otic polyp also called aural polyp is a benign proliferation of chronic inflammatory cells associated with granulation tissue in response to a longstanding inflammatory process of the middle ear
otitis is a general term for inflammation or infection of the ear in both humans and other animals it is subdivided into the following otitis externa external otitis or swimmer s ear involves the outer ear and ear canal in external otitis the ear hurts when touched or pulled otitis media or middle ear infection involves the middle ear in otitis media the ear is infected or clogged with fluid behind the ear drum in the normally air filled middle ear space this very common childhood infection sometimes requires a surgical procedure called myringotomy and tube insertion otitis interna or labyrinthitis involves the inner ear the inner ear includes sensory organs for balance and hearing when the inner ear is inflamed vertigo is a common symptom
otitis externa also known as swimmer s ear is an inflammation of the ear canal it often presents with ear pain swelling of the ear canal and occasionally decreased hearing typically there is pain with movement of the outer ear a high fever is typically not present except in severe cases otitis externa may be acute meaning less than six weeks or chronic meaning more than three months in duration acute cases are typically due to a bacterial infection while chronic cases are often due to allergies or autoimmune disorders risk factors for acute cases include swimming minor trauma from cleaning using hearing aids or ear plugs and other skin problems like psoriasis or dermatitis those with diabetes are at risk of a severe form of disease known as malignant otitis externa diagnosis is based on the signs and symptoms culturing the ear canal may be useful in chronic or severe cases acetic acid ear drops may be used as a preventative measure treatment of acute cases is typically with antibiotic drops such as ofloxacin or acetic acid steroid drops may be used in addition to antibiotics pain medications such as ibuprofen may be used for the pain antibiotics by mouth are not recommended unless the person has poor immune function or there is infection of the skin around the ear typically improvement occurs within a day of starting treatment treatment of chronic cases depends on the cause otitis externa affects 1 3 of people a year with more than 95 of cases being acute about 10 of people are affected at some point in their life it occurs most commonly among children between the ages of seven and twelve and among the elderly it occurs with near equal frequency in males and females those who live in warm and wet climates are more often affected
otitis externa is an inflammation of the outer ear and ear canal animals are commonly prone to ear infection and this is one of the most common manifestations of allergy in dogs in dogs those breeds with floppy ears are more prone since air flow is limited and a warm moist environment built up which is conducive to infection the external ear in animals is longer and deeper than in humans which makes it easier for infection or wax to build up or be hard to remove complete ear canal inspection requires the use of an otoscope by a veterinarian infections are usually secondary to inflammation or to improper grooming techniques infections can be caused by both bacterial and fungal origin as well as small organisms such as ear mites malassezia pachydermatis is a common fungal agent for ear infections in dogs staphylococcus intermedius is the most common bacterial infection a more serious ear infection with pus in the ear may be caused by pseudomonas aeruginosa
otitis media is a group of inflammatory diseases of the middle ear the two main types are acute otitis media aom and otitis media with effusion ome aom is an infection of abrupt onset that usually presents with ear pain in young children this may result in pulling at the ear increased crying and poor sleep decreased eating and a fever may also be present ome is typically not associated with symptoms occasionally a feeling of fullness is described it is defined as the presence of non infectious fluid in the middle ear for more than three months chronic suppurative otitis media csom is middle ear inflammation of greater than two weeks that results in episodes of discharge from the ear it may be a complication of acute otitis media pain is rarely present all three may be associated with hearing loss the hearing loss in ome due to its chronic nature may affect a child s ability to learn the cause of aom is related to childhood anatomy and immune function either bacteria or viruses may be involved risk factors include exposure to smoke use of pacifiers and attending daycare it occurs more commonly in those who are native american or who have down syndrome ome frequently occurs following aom and may be related to viral upper respiratory infections irritants such as smoke or allergies looking at the eardrum is important for making the correct diagnosis signs of aom include bulging or a lack of movement of the tympanic membrane from a puff of air new discharge not related to otitis externa also indicates the diagnosis a number of measures decrease the risk of otitis media including pneumococcal and influenza vaccination exclusive breastfeeding for the first six months of life and avoiding tobacco smoke the use of pain medications for aom is important this may include paracetamol acetaminophen ibuprofen benzocaine ear drops or opioids in aom antibiotics may speed recovery but may result in side effects antibiotics are often recommended in those with severe disease or under two years old in those with less severe disease they may only be recommended in those who do not improve after two or three days the initial antibiotic of choice is typically amoxicillin in those with frequent infections tympanostomy tubes may decrease recurrence in children with otitis media with effusion antibiotics may increase resolution of symptoms but may cause diarrhoea vomiting and skin rash worldwide aom affect about 11 of people a year about 325 to 710 million cases half the cases involve children less than five years of age and it is more common among males of those affected about 4 8 or 31 million develop chronic suppurative otitis media before the age of ten ome affects about 80 of children at some point otitis media resulted in 2 400 deaths in 2013 – down from 4 900 deaths in 1990
otocephaly from the greek words οτο meaning “ ear ” and κεφάλη meaning head is a type of head disorder cephalic disorder this is a lethal condition in which the primary feature is the total or virtual absence of the lower jaw a developmental anomaly called agnathia the “ oto ” in the name refers to the relationship of the ears to the face in this disorder the condition is considered lethal because of a poorly functioning airway in otocephaly agnathia may occur alone or together with holoprosencephaly
otodental syndrome also known as otodental dysplasia is an exceptionally rare disease that is distinguished by a specific phenotype known as globodontia that in rare cases can be associated with eye coloboma and high frequency hearing loss globodontia is an abnormal condition that can occur in both the primary and secondary dentition except for the incisors which are normal in shape and size this is demonstrated by significant enlargement of the canine and molar teeth the premolars are either reduced in size or are absent in some cases the defects affecting the teeth eye and ear can be either individual or combined when these conditions are combined with eye coloboma the condition is also known as oculo otodental syndrome the first known case of otodental syndrome was found in hungary in a mother and her son by denes and csiba in 1969 prevalence is less than 1 out of every 1 million individuals the cause of otodental syndrome is considered to be genetic it is an autosomal dominant inheritance and is variable in its expressivity haploinsufficiency in the fibroblast growth factor 3 fgf 3 gene 11 q 13 has been reported in patients with otodental syndrome and is thought to cause the phenotype both males and females are equally affected individuals diagnosed with otodental syndrome can be of any age age is not a relevant factor currently there are no specific genetic treatments for otodental syndrome dental and orthodontic management are the recommended course of action
otofacial syndrome is an extremely rare congenital deformity whereby the afflicted is born without a jaw and subsequently a chin in nearly all cases the child does not survive because of the inability to breathe and eat properly even with reconstructive surgery the tongue is extremely underdeveloped making unaided breathing and swallowing impossible
otomycosis is a fungal ear infection a superficial mycotic infection of the outer ear canal it is more common in the tropical countries the infection may be either subacute or acute and is characterized by malodorous discharge inflammation pruritus scaling and severe discomfort suppuration can occur due to superimposed bacterial infection commonly due to pseudomonas species and proteus species the mycosis results in inflammation superficial epithelial exfoliation masses of debris containing hyphae suppuration and pain
otophyma is a cauliflower like swelling of one or both ears
otosclerosis or otospongiosis is an abnormal growth of bone near the middle ear it can result in hearing loss the term otosclerosis is somewhat of a misnomer much of the clinical course is characterised by lucent rather than sclerotic bony changes hence it is also known as otospongiosis
otospondylomegaepiphyseal dysplasia osmed is an autosomal recessive disorder of bone growth that results in skeletal abnormalities severe hearing loss and distinctive facial features the name of the condition indicates that it affects hearing oto and the bones of the spine spondylo and enlarges the ends of bones megaepiphyses the features of osmed are similar to those of another skeletal disorder weissenbacher zweymüller syndrome otospondylomegaepiphyseal dysplasia is a subtype of collagenopathy types ii and xi
ototoxicity is the property of being toxic to the ear oto specifically the cochlea or auditory nerve and sometimes the vestibular system for example as a side effect of a drug the effects of ototoxicity can be reversible and temporary or irreversible and permanent it has been recognised since the 19 th century there are many well known ototoxic drugs used in clinical situations and they are prescribed despite the risk of hearing disorders to very serious health conditions ototoxic drugs include antibiotics such as gentamicin loop diuretics such as furosemide and platinum based chemotherapy agents such as cisplatin a number of nonsteroidal anti inflammatory drugs nsaids have also been shown to be ototoxic this can result in sensorineural hearing loss dysequilibrium or both some environmental and occupational chemicals have also been shown to affect the auditory system and interact with noise
the out group homogeneity effect is one s perception of out group members as more similar to one another than are in group members e g they are alike we are diverse the term outgroup homogeneity effect outgroup homogeneity bias or relative outgroup homogeneity has been explicitly contrasted with outgroup homogeneity in general the latter referring to perceived outgroup variability unrelated to perceptions of the ingroup the out group homogeneity effect is part of a broader field of research that examines perceived group variability this area includes in group homogeneity effects as well as out group homogeneity effects and it also deals with perceived group variability effects that are not linked to in group out group membership such as effects that are related to the power status and size of groups the out group homogeneity effect has been found using a wide variety of different social groups from political and racial groups to age and gender groups the implications of this effect on stereotyping have been noted perceivers tend to have impressions about the diversity or variability of group members around those central tendencies or typical attributes of those group members thus outgroup stereotypicality judgments are overestimated supporting the view that out group stereotypes are overgeneralizations the outgroup homogeneity effect is sometimes referred to as outgroup homogeneity bias such nomenclature hints at a broader meta theoretical debate that is present in the field of social psychology this debate centres on the validity of heightened perceptions of ingroup and outgroup homogeneity where some researchers view the homogeneity effect as an example of cognitive bias and error while other researchers view the effect as an example of normal and often adaptive social perception
an out route or down and out or jet route is a pattern run by a receiver in american football on an out route the receiver will start running a fly pattern i e running straight down the field toward the end zone but after a certain number of steps will cut hard 90 degrees to the outside or toward the sideline away from the quarterback if the cut comes very quickly usually after only a few steps it is called a quick out out routes generally allow a one on one match up between the receiver and the defensive back who is guarding him as safeties generally are concerned with helping out on long routes downfield or the center of the field this route is used much more frequently near the end of each half or when a team is running their two minute drill to preserve time on the clock because as soon as the receiver catches the ball or after a short run after the catch he should be able to get out of bounds stopping the clock it is a quick execution play if the ball is thrown correctly usually a defensive player can t respond quickly enough to interfere it is also often called in a 3 rd down situation where the full ten yards are needed out and in routes are the most difficult routes to cover in man to man coverage but can be dangerous plays to run because if the defender intercepts the pass he will often have a clear path to the end zone
in epidemiology an outbreak is a sudden increase in occurrences of a disease in a particular time and place it may affect a small and localized group or impact upon thousands of people across an entire continent two linked cases of a rare infectious disease may be sufficient to constitute an outbreak outbreaks include epidemics which term is normally only used for infectious diseases as well as diseases with an environmental origin such as a water or foodborne disease they may affect a region in a country or a group of countries pandemics are near global disease outbreaks
the outcome bias is an error made in evaluating the quality of a decision when the outcome of that decision is already known specifically the outcome effect occurs when the same behavior produce s more ethical condemnation when it happen s to produce bad rather than good outcome even if the outcome is determined by chance while similar to the hindsight bias the two phenomena are markedly different the hindsight bias focuses on memory distortion to favor the actor while the outcome bias focuses exclusively on weighting the past outcome heavier than other pieces of information in deciding if a past decision was correct
output compare is the ability to trigger an output based on a timestamp in memory without interrupting the execution of code by a processor or microcontroller this is a functionality provided by many embedded systems the corresponding ability to record a timestamp in memory when an input occurs is called input capture
in economics the outside lag is the amount of time it takes for a government or central bank s actions in the form of either monetary or fiscal policy to have a noticeable effect on the economy its converse is the inside lag the amount of time it takes the policy authority to recognize that a situation calls for a policy response and to decide on that response and implement it the outside lag can be a major problem and must be taken into account in deciding what expansionary or contractionary policy actions to implement and indeed whether to implement any at all
ovarian apoplexy is a sudden rupture in the ovary commonly at the site of a cyst accompanied by hemorrhage in the ovarian tissue and or intraperitoneal bleeding
ovarian cancer is a cancer that forms in an ovary it results in abnormal cells that have the ability to invade or spread to other parts of the body when this process begins there may be no or only vague symptoms symptoms become more noticeable as the cancer progresses these symptoms may include bloating pelvic pain abdominal swelling and loss of appetite among others common areas to which the cancer may spread include the lining of the abdomen lining of the bowel and bladder lymph nodes lungs and liver the risk of ovarian cancer increases in women who have ovulated more over their lifetime this includes those who have never had children those who begin ovulation at a younger age or reach menopause at an older age other risk factors include hormone therapy after menopause fertility medication and obesity factors that decrease risk include hormonal birth control tubal ligation and breast feeding about 10 of cases are related to inherited genetic risk women with mutations in the genes brca 1 or brca 2 have about a 50 chance of developing the disease the most common type of ovarian cancer comprising more than 95 of cases is ovarian carcinoma there are five main subtypes of ovarian carcinoma of which high grade serous carcinoma is the most common these tumors are believed to start in the cells covering the ovaries though some may form at the fallopian tubes less common types of ovarian cancer include germ cell tumors and sex cord stromal tumors a diagnosis of ovarian cancer is confirmed through a biopsy of tissue usually removed during surgery screening is not recommended in women who are at average risk as evidence does not support a reduction in death and the high rate of false positive tests may lead to unneeded surgery which is accompanied by its own risks those at very high risk may have their ovaries removed as a preventive measure if caught and treated in an early stage ovarian cancer may be curable treatment usually includes some combination of surgery radiation therapy and chemotherapy outcomes depend on the extent of the disease and the subtype of the cancer present the overall five year survival rate in the united states is 45 outcomes are worse in the developing world in 2012 ovarian cancer occurred in 239 000 women and resulted in 152 000 deaths worldwide this makes it among women the seventh most common cancer and the eighth most common cause of death from cancer the typical age of diagnosis is 63 death from ovarian cancer is more common in north america and europe than in africa and asia
an ovarian cyst is a fluid filled sac within the ovary often they cause no symptoms occasionally they may produce bloating lower abdominal pain or lower back pain if the cyst either breaks open or causes twisting of the ovary severe pain may occur this may result in vomiting or feeling faint the majority of cysts are however harmless most ovarian cysts are related to ovulation being either follicular cysts or corpus luteum cysts other types include cysts due to endometriosis dermoid cysts and cystadenomas many small cysts occur in both ovaries in polycystic ovarian syndrome pelvic inflammatory disease may also result in cysts rarely cysts may be a form of ovarian cancer diagnosis is undertaken by pelvic examination with an ultrasound or other testing used to gather further details often cysts are simply observed over time if they cause pain medications such as paracetamol acetaminophen or ibuprofen may be used hormonal birth control may be used to prevent further cysts in those who are frequently affected however evidence does not support birth control as a treatment of current cysts if they do not go away after several months get larger look unusual or cause pain they may be removed by surgery most women of reproductive age develop small cysts each month large cysts that cause problems occur in about 8 of women before menopause ovarian cysts are present in about 16 of women after menopause and if present are more likely to be cancer
ovarian cystadenoma is a cystic benign tumor of the ovary two types are recognized serous and mucinous
ovarian diseases can be classified as endocrine disorders or as a disorders of the reproductive system if the egg fails to release from the follicle in the ovary an ovarian cyst may form small ovarian cysts are common in healthy women some women have more follicles than usual polycystic ovary syndrome which inhibits the follicles to grow normally and this will cause cycle irregularities other conditions include ovarian cancer luteoma hypogonadism hyperthecosis
the ovarian fibroma also fibroma is a benign sex cord stromal tumour ovarian fibromas represent 4 of all ovarian neoplasms they tend to occur mostly during perimenopause and postmenopause the median age having been reported to be about 52 years and they are rare in children lesions tend to be asymptomatic if symptoms are present the most common one is abdominal pain on gross pathology they are firm and white or tan on microscopic examination there are intersecting bundles of spindle cells producing collagen there may be thecomatous areas fibrothecoma the presence of an ovarian fibroma can cause ovarian torsion in some cases
ovarian hyperstimulation syndrome ohss is a medical condition affecting the ovaries of some women who take fertility medication to stimulate egg growth most cases are mild but rarely the condition is severe and can lead to serious illness or death
ovarian pregnancy refers to an ectopic pregnancy that is located in the ovary typically the egg cell is not released or picked up at ovulation but fertilized within the ovary where the pregnancy implants such a pregnancy usually does not proceed past the first four weeks of pregnancy an untreated ovarian pregnancy causes potentially fatal intraabdominal bleeding and thus may become a medical emergency
ovarian serous cystadenoma also less precisely known as serous cystadenoma is the most common ovarian neoplasm representing 20 of ovarian neoplasms and is benign it has a very superficial resemblance to the most common type of ovarian cancer serous carcinoma of the ovary under the microscope however 1 it is virtually impossible to mix up with its malignant counterpart serous carcinoma and 2 does not share genetic traits of indeterminate serous tumours also called serous borderline tumours that may transform into serous carcinoma serous cystadenomas of the ovary are not related to serous cystadenomas of the pancreas i e the presence of an ovarian or pancreatic one does not suggest an increased risk for the other one
ovarian torsion accounts for about 3 of gynecologic emergencies the incidence of ovarian torsion among women of all ages is 5 9 per 100 000 women and the incidence among women of reproductive age 15 – 45 years is 9 9 per 100 000 women in 70 of cases it is diagnosed in women between 20 and 39 years of age the risk is greater during pregnancy and in menopause risk factors include increased length of the ovarian ligaments pathologically enlarged ovaries more than 6 cm ovarian masses or cysts and enlarged corpus luteum in pregnancy
ovarian tumors or ovarian neoplasms are tumors arising from the ovary they can benign or malignant ovarian cancer
in medicine ovarian vein syndrome is a rare possibly not uncommon certainly under diagnosed condition in which a dilated ovarian vein compresses the ureter the tube that brings the urine from the kidney to the bladder this causes chronic or colicky abdominal pain back pain and or pelvic pain the pain can worsen on lying down or between ovulation and menstruation there can also be an increased tendency towards urinary tract infection or pyelonephritis kidney infection the right ovarian vein is most commonly involved although the disease can be left sided or affect both sides it is currently classified as a form of pelvic congestion syndrome
over illumination is the presence of lighting intensity higher than that which is appropriate for a specific activity over illumination was commonly ignored between 1950 and 1995 especially in office and retail environments since then however the interior design community has begun to reconsider this practice over illumination encompasses two separate concerns unnecessary electric lighting is expensive and energy intensive lighting accounts for approximately 9 of residential electricity use as of 2001 and about 40 of commercial electricity use excessive levels of artificial light may adversely affect health these detrimental effects may depend on the spectrum as well as the overall brightness level of light over illumination can be reduced by installing occupancy sensors using natural sunlight whenever possible turning off lights when leaving a room or changing the type of lightbulb over illumination does not refer to snowblindness where high exposure to ultraviolet light causes physical damage to the eye too little light the opposite of over illumination is associated with seasonal affective disorder
overaccumulation is one of the potential causes of the crisis of capital accumulation a crisis of capital occurs due to what karl marx refers to as the internal contradictions inherent in the capitalist system which result in the reconfiguration of production the contradiction in this situation is realized because of the condition of capitalism that requires the accumulation of capital through the continual reinvestment of surplus value accumulation can reach a point where the reinvestment of capital no longer produces returns when a market becomes flooded with capital a massive devaluation occurs this over accumulation is a condition that occurs when surpluses of devalued capital and labor exist side by side with seemingly no way to bring them together the inability to procure adequate value stems from a lack of demand the term overaccumulation is also used in a neoclassical context
overactive bladder oab also known as overactive bladder syndrome is a condition where there is a frequent feeling of needing to urinate to a degree that it negatively affects a person s life the frequent need to urinate may occur during the day at night or both if there is loss of bladder control then it is known as urge incontinence more than 40 of people with overactive bladder have incontinence while about 40 to 70 of urinary incontinence is due to overactive bladder it is not life threatening most people with the condition have problems for years the cause of overactive bladder is unknown risk factors include obesity caffeine and constipation poorly controlled diabetes poor functional mobility and chronic pelvic pain may worsen the symptoms people often have the symptoms for a long time before seeking treatment and the condition is sometimes identified by caregivers diagnosis is based on a person s signs and symptoms and requires other problems such as urinary tract infections or neurological conditions to be excluded the amount of urine passed during each urination is relatively small pain while urinating suggests that there is a problem other than overactive bladder specific treatment is not always required if treatment is desired pelvic floor exercises bladder training and other behavioral methods are initially recommended weight loss in those who are overweight decreasing caffeine consumption and drinking moderate fluids can also have benefits medications typically of the anti muscarinic type are only recommended if other measures are not effective they are no more effective than behavioral methods however they are associated with side effects particularly in older people some non invasive electrical stimulation methods appear effective while they are in use injections of botulinum toxin into the bladder is another option urinary catheters or surgery are generally not recommended a diary to track problems can help determine whether treatments are working overactive bladder is estimated to occur in 7 27 of men and 9 43 of women it becomes more common with age some studies suggest that the condition is more common in women especially when associated with loss of bladder control economic costs of overactive bladder were estimated in the united states at 12 6 billion usd and 4 2 billion euro in 2000
overactive disorder associated with mental retardation and stereotyped movements is a pervasive developmental disorder pdd listed in chapter v f of the tenth revision of the international statistical classification of diseases and related health problems icd 10 its diagnostic code is f 84 4
under the marketing allotment provisions of the sugar program authorized by the 2002 farm bill p l 107 171 sec 1403 the overall allotment quantity oaq is the amount of domestically produced sugar that processors of sugar cane and refiners of sugar beets can sell into the u s market during a fiscal year the 2002 farm bill requires usda to set the oaq using the following formula estimated sugar consumption reasonable carryover or ending stocks minus 1 532 000 short tons carry in or beginning stocks what usda decides is a reasonable carryover stock level is closely watched by the sugar industry because of its influence on prices sugar production in excess of the oaq sometimes referred to as “ blocked stocks ” cannot be marketed
overbite medically refers to the extent of vertical superior inferior overlap of the maxillary central incisors over the mandibular central incisors measured relative to the incisal ridges the term overbite does not refer to a specific condition nor is it a form of malocclusion rather an absent or excess overbite would be a malocclusion normal overbite is between 3 – 5 mm or approximately 20 – 30 of the height of the mandibular incisors and is commonly expressed as a percentage young children commonly have a deep bite excessive overbite it is not resolved during the normal growth of the maxilla and the mandible and can get worse with time if it is not corrected it may lead to trauma and shortening the length of the teeth due to wear and the biting edges
overcast or overcast weather as defined by the world meteorological organization is the meteorological condition of clouds obscuring all of the sky by at least 95 percent however the total sky cover must not be entirely due to surface based obscuring phenomena such as fog overcast written as ovc in the metar observation is reported when the cloud cover is observed to equal eight oktas eighths an overcast sky may be explicitly identified as thin predominantly transparent but otherwise is considered opaque which always constitutes a ceiling in aviation meteorology sometimes clouds can be different colors such as black or white but overcast usually refers to darker skies in some cases it can be impossible to see distinct borders of clouds or the sky may be covered by a single type of cloud such as stratus and the whole sky will be a dull white periods of overcast weather can range from a few hours to several days overcast weather can also affect people suffering from seasonal affective disorder the same weather when observed from above might be referred to as an undercast
overdiagnosis is the diagnosis of disease that will never cause symptoms or death during a patient s lifetime overdiagnosis is a side effect of screening for early forms of disease although screening saves lives in some cases in others it may turn people into patients unnecessarily and may lead to treatments that do no good and perhaps do harm given the tremendous variability that is normal in biology it is inherent that the more one screens the more incidental findings will be found for a large percentage of them the most appropriate medical response is to recognize them as something that does not require intervention but determining which action a particular finding warrants ignoring watchful waiting or intervention can be very difficult whether because the differential diagnosis is uncertain or because the risk ratio is uncertain risks posed by intervention namely adverse events versus risks posed by not intervening overdiagnosis occurs when a disease is diagnosed correctly but the diagnosis is irrelevant a correct diagnosis may be irrelevant because treatment for the disease is not available not needed or not wanted some people contend that the term overdiagnosis is inappropriate and that overtreatment is more representative of the phenomenon because most people who are diagnosed are also treated it is difficult to assess whether overdiagnosis has occurred in an individual overdiagnosis in an individual cannot be determined during life overdiagnosis is only certain when an individual remains untreated never develops symptoms of the disease and dies of something else thus most of the inferences about overdiagnosis comes from the study of populations rapidly rising rates of testing and disease diagnosis in the setting of stable rates of the feared outcome of the disease e g death are highly suggestive of overdiagnosis most compelling however is evidence from a randomized trial of a screening test intended to detect pre clinical disease a persistent excess of detected disease in the tested group years after the trial is completed constitutes the best evidence that overdiagnosis has occurred although overdiagnosis is potentially applicable to the diagnosis of any disease its origin is in cancer screening – the systematic evaluation of asymptomatic patients to detect early forms of cancer the central harm of cancer screening is overdiagnosis – the detection of abnormalities that meet the pathologic definition of cancer under the microscope but will never progress to cause symptoms or death during a patient s lifetime
in statistics overdispersion is the presence of greater variability statistical dispersion in a data set than would be expected based on a given statistical model a common task in applied statistics is choosing a parametric model to fit a given set of empirical observations this necessitates an assessment of the fit of the chosen model it is usually possible to choose the model parameters in such a way that the theoretical population mean of the model is approximately equal to the sample mean however especially for simple models with few parameters theoretical predictions may not match empirical observations for higher moments when the observed variance is higher than the variance of a theoretical model overdispersion has occurred conversely underdispersion means that there was less variation in the data than predicted overdispersion is a very common feature in applied data analysis because in practice populations are frequently heterogeneous non uniform contrary to the assumptions implicit within widely used simple parametric models
overdominance is a condition in genetics where the phenotype of the heterozygote lies outside the phenotypical range of both homozygous parents overdominance can also be described as heterozygote advantage wherein heterozygous individuals have a higher fitness than homozygous individuals an example in humans is sickle cell anemia this condition is determined by a single polymorphism possessors of the deleterious allele have lower life expectancy with homozygotes rarely reaching 50 years of age however this allele also yields some resistance to malaria thus in regions where malaria exerts or has exerted a strong selective pressure sickle cell anemia has been selected for its conferred partial resistance to the disease while homozygotes will have either no protection from malaria or a dramatic propensity to sickle cell anemia heterozygotes have fewer physiological effects and a partial resistance to malaria
in telecommunications overfill is the condition that prevails when the numerical aperture or the beam diameter of an optical source such as a laser light emitting diode or optical fiber exceeds that of the driven element e g an optical fiber core in optical communications testing overfill in both numerical aperture and mean diameter core diameter or spot size is usually required in polygonal mirror scanners an overfilled type is one which uses each mirror facet at least in one dimension completely
overflow incontinence is a form of urinary incontinence characterized by the involuntary release of urine from an overfull urinary bladder often in the absence of any urge to urinate this condition occurs in people who have a blockage of the bladder outlet benign prostatic hyperplasia prostate cancer or narrowing of the urethra or when the muscle that expels urine from the bladder is too weak to empty the bladder normally overflow incontinence may also be a side effect of certain medications
overgeneral autobiographical memory ogm is an inability to retrieve specific memories from one s autobiographical memory instead general memories are recalled such as repeated events or events occurring over broad periods for example when asked to recall a happy event a person who exhibits ogm may say when i was on vacation last month instead of remembering a single incident such as my high school graduation research shows a correlation between ogm and certain mental illnesses such as major depressive disorder mdd and posttraumatic stress disorder ptsd
overjet is the extent of horizontal anterior posterior overlap of the maxillary central incisors over the mandibular central incisors in class ii division i malocclusion the overjet is increased as the maxillary central incisors are protruded
an overlap syndrome is an autoimmune disease of connective tissue in which a patient presents with symptoms of two or more diseases examples of overlap syndromes include mixed connective tissue disease and scleromyositis diagnosis depends on which diseases the patient shows symptoms and has positive antibodies for in their lab serology in overlap syndrome features of the following diseases are found most common listed systemic lupus erythematosus sle systemic sclerosis polymyositis dermatomyositis rheumatoid arthritis ra sjögren s syndrome eosinophilic granulomatosis with polyangiitis egpa autoimmune thyroiditis antiphospholipid antibody syndrome the treatment of overlap syndrome is mainly based on the use of corticosteroids and immunosuppressants biologic drugs i e anti tnfα or anti cd 20 monoclonal antibodies have been recently introduced as alternative treatments in refractory cases there are some concerns with the use of anti tnf agents in patients with systemic autoimmune diseases due to the risk of triggering disease exacerbations
an overlapping circles grid is a geometric pattern of repeating overlapping circles of equal radii in two dimensional space the two most common designs are based on circles centered on triangular and square lattice pattern of points patterns of seven overlapping circles appear in historical artefacts from the 8 th century bc onwards they are found on a cypro archaic i cup of the 8 th 7 th century bc in cyprus at the temple of osiris at abydos in ancient egypt and on roman mosaics for example at herod s palace in the 1 st century bc the patterns are used extensively to construct girih decorations including 6 and 12 pointed stars in islamic art patterns based on a square grid of overlapping circles are found in quilt design in ancient egypt as noted in the 1856 book the grammar of ornament and in the hindu temple at prambanan in java
the overman rearrangement is a chemical reaction that can be described as a claisen rearrangement of allylic alcohols to give allylic trichloroacetamides through an imidate intermediate the overman rearrangement was discovered in 1974 by larry overman the overman rearrangement the 3 3 sigmatropic rearrangement is diastereoselective and requires heating or the use of hg ii or pd ii salts as catalysts the resulting allylamine structures can be transformed into many chemically and biologically important natural and un natural amino acids like 1 adamantyl glycine the overman rearrangement may also be used for asymmetric synthesis
overmodulation is the condition that prevails in telecommunication when the instantaneous level of the modulating signal exceeds the value necessary to produce 100 modulation of the carrier in the sense of this definition it is almost always considered a fault condition in layman s terms the signal is going off the scale overmodulation results in spurious emissions by the modulated carrier and distortion of the recovered modulating signal this means that the envelope of the output waveform is distorted although overmodulation is sometimes considered permissible it should not occur in practice a distorted waveform envelope will result in a distorted output signal of the receiving medium
in electrochemistry overpotential is the potential difference voltage between a half reaction s thermodynamically determined reduction potential and the potential at which the redox event is experimentally observed the term is directly related to a cell s voltage efficiency in an electrolytic cell the existence of overpotential implies the cell requires more energy than thermodynamically expected to drive a reaction in a galvanic cell the existence of overpotential means less energy is recovered than thermodynamics predicts in each case the extra missing energy is lost as heat the quantity of overpotential is specific to each cell design and varies across cells and operational conditions even for the same reaction overpotential is experimentally determined by measuring the potential at which a given current density typically small is achieved
overpressure or blast overpressure is the pressure caused by a shock wave over and above normal atmospheric pressure the shock wave may be caused by sonic boom or by explosion and the resulting overpressure receives particular attention when measuring the effects of nuclear weapons or thermobaric bombs
an overriding aorta is a congenital heart defect where the aorta is positioned directly over a ventricular septal defect vsd instead of over the left ventricle the result is that the aorta receives some blood from the right ventricle causing mixing of oxygenated and deoxygenated blood and thereby reducing the amount of oxygen delivered to the tissues it is one of the four findings in the classic tetralogy of fallot the other three findings are right ventricular outflow tract rvot obstruction most often subpulmonary stenosis right ventricular hypertrophy rvh and ventricular septal defect vsd
an overshooting top or penetrating top is a dome like protrusion that shoots out of the top of the anvil of a thunderstorm when an overshooting top is present for 10 minutes or longer it is a strong indication that the thunderstorm may be severe
overspeed is the aircraft flight condition when the airspeed exceeds a safe limitation this is hazardous as it may damage the flight control surfaces or airframe never exceed speed maximum speed for stability characteristics maximum operating limit speed maximum flap extended speed maximum landing gear extended speed maximum landing gear operating speed
overspeed is a condition in which an engine is allowed or forced to turn beyond its design limit the consequences of running an engine too fast vary by engine type and model and depend upon several factors chief amongst them the duration of the overspeed and by the speed attained with some engines even a momentary overspeed can result in greatly reduced engine life or even catastrophic failure the speed of an engine is ordinarily measured in revolutions per minute rpm
overtime is the amount of time someone works beyond normal working hours the term is also used for the pay received for this time normal hours may be determined in several ways by custom what is considered healthy or reasonable by society by practices of a given trade or profession by legislation by agreement between employers and workers or their representatives most nations have overtime labour laws designed to dissuade or prevent employers from forcing their employees to work excessively long hours these laws may take into account other considerations than the humanitarian such as preserving the health of workers so that they may continue to be productive or increasing the overall level of employment in the economy one common approach to regulating overtime is to require employers to pay workers at a higher hourly rate for overtime work companies may choose to pay workers higher overtime pay even if not obliged to do so by law particularly if they believe that they face a backward bending supply curve of labour overtime pay rates can cause workers to work longer hours than they would at a flat hourly rate overtime laws attitudes toward overtime and hours of work vary greatly from country to country and between different economic sectors
overview and scrutiny is a function of local authorities in england and wales it was introduced by the local government act 2000 which created separate executive and overview and scrutiny functions within councils councils operating executive arrangements are required to create an overview and scrutiny committee which is composed of councillors who are not on the executive committee or cabinet of that council overview and scrutiny committees are required to meet the rules on proportionality defined in the local government and housing act 1989 i e the committee must reflect the respective sizes of the political groups on the council councils in england which use the committee system are not required to establish an overview and scrutiny committee but may do so if they wish there is no national standard or prescription on the committee structure that councils adopt to satisfy these legislative requirements a wide variety of designations and structures are in use ranging from single committees to multiple committees with sub committees structures have no significant impact on the overall effectiveness of the scrutiny function in individual authorities the law relating to overview and scrutiny is slightly different in england wales and northern ireland in scotland councils all operate under the committee system although some incorporate policy development groups which perform similar functions to overview and scrutiny committees
overweight is having more body fat than is optimally healthy being overweight is common especially where food supplies are plentiful and lifestyles are sedentary excess weight has reached epidemic proportions globally with more than 1 billion adults being either overweight or obese in 2003 in 2013 this increased to more than 2 billion increases have been observed across all age groups a healthy body requires a minimum amount of fat for proper functioning of the hormonal reproductive and immune systems as thermal insulation as shock absorption for sensitive areas and as energy for future use but the accumulation of too much storage fat can impair movement flexibility and alter appearance of the body
ovine rinderpest also commonly known as peste des petits ruminants ppr is a contagious disease affecting goats and sheep in africa from the tropic of cancer to the equator the middle east and the indian subcontinent but since june 2008 the disease invaded morocco which indicates a crossing of the natural barrier of the sahara it is caused by a species of the morbillivirus genus of viruses the disease is highly contagious and has roughly an 80 percent mortality rate in acute cases
owl s eye appearance is a pattern in medical radiology and histopathology and may refer to owl s eye appearance of inclusion bodies which is highly specific for cytomegalovirus infection owl s eye appearance of entire nucleus a finding in reed – sternberg cells in individuals with hodgkin s lymphoma owl s eye appearance of the lentiform nucleus of the basal ganglia on head ct scan images in individuals with cerebral hypoxia
oxfendazole is a broad spectrum benzimidazole anthelmintic its main use is for protecting livestock against roundworm strongyles and pinworms oxfendazole is the sulfoxide metabolite of fenbendazole oxfendazole is an anthelmintic wormer compound used in veterinary practice it comes under the chemical class of the benzimidazoles this drug is barely used in horses goats sheep and cattle it is very scarcely applied on dogs and cats the drug for livestock is majorly available in the form of pills tablets drenches bolus etc they are meant for oral consumption several drenches are allowed for intraruminal injection in some of the countries few countries also prefer injectables and pour ons for pet dogs the drug is available in the form of drenches
rivalry between the universities of oxford and cambridge is a phenomenon going back many centuries during most of that time they were the only two universities in england and wales making the rivalry more intense than it is now the university of oxford and the university of cambridge sometimes collectively known as oxbridge are the two oldest universities in the united kingdom both were founded more than 800 years ago and between them they have produced a large number of britain s most prominent scientists writers and politicians as well as noted figures in many other fields competition between oxford and cambridge also has a long history dating back to around 1208 when cambridge was founded by scholars taking refuge from hostile townsmen in oxford
the oxidation of primary alcohols to carboxylic acids is an important oxidation reaction in organic chemistry when a primary alcohol is converted to a carboxylic acid the terminal carbon atom increases its oxidation state by four oxidants able to perform this operation in complex organic molecules featuring other oxidation sensitive functional groups must possess substantial selectivity the most common oxidants are potassium permanganate kmno 4 jones reagent pcc in dmf heyns oxidation ruthenium tetroxide ruo 4 and tempo oxidation of primary alcohols to carboxylic acids
the oxidation of secondary alcohols to ketones is an important oxidation reaction in organic chemistry when a secondary alcohol is oxidised it is converted to a ketone the hydrogen from the hydroxyl group is lost along with the hydrogen bonded to the second carbon the remaining oxygen then forms double bonds with the carbon this leaves a ketone as r 1 – cor 2 ketones cannot normally be oxidised any further because this would involve breaking a c – c bond which requires too much energy the reaction can occur using a variety of oxidants
oxidative coupling in chemistry is a coupling reaction of two molecular entities through an oxidative process usually catalysed by a transition metal compound and involving dioxygen as the oxidant a relevant aliphatic coupling reaction is the oxidative coupling of methane
the oxidative coupling of methane ocm is a type of chemical reaction discovered in the 1980 s for the direct conversion of natural gas primarily consisting of methane into value added chemicals direct conversion of methane into other useful products is one of the most challenging subjects to be studied in heterogeneous catalysis methane activation is difficult because of its thermodynamic stability with a noble gas like electronic configuration the tetrahedral arrangement of strong c – h bonds 435 kj mol offer no functional group magnetic moments or polar distributions to undergo chemical attack this makes methane less reactive than nearly all of its conversion products limiting efficient utilization of natural gas the world ’ s most abundant petrochemical resource
oxidative decarboxylation reactions are oxidation reactions in which a carboxylate group is removed forming carbon dioxide they often occur in biological systems there are many examples in the citric acid cycle
the expansive force of rusting which may be called oxide jacking or rust burst is a phenomenon that can cause damage to structures made of stone masonry concrete or ceramics and reinforced with metal components a definition is the displacement of building elements due to the expansion of iron and steel products as the metal rusts and becomes iron oxide corrosion of other metals such as aluminum can also cause oxide jacking
an oxo diels – alder reaction also called an oxa diels – alder reaction is an organic reaction and a variation of the diels – alder reaction in which a suitable diene reacts with an aldehyde to form a dihydropyran ring this reaction is of some importance to synthetic organic chemistry oxo diels – alder reaction general the oxo da reaction was first reported in 1949 using a methylpentadiene and formaldehyde as reactants oxo diels – alder reaction gresham 1949 asymmetric oxo da reactions including catalytic reactions are well known many strategies rely on coordinating a chiral lewis acid to the carbonyl group
an oxyanion hole is a pocket in the active site of an enzyme that stabilizes transition state negative charge on a deprotonated oxygen or alkoxide the pocket typically consists of backbone amides or positively charged residues stabilising the transition state lowers the activation energy necessary for the reaction and so promotes catalysis for example proteases such as chymotrypsin contain an oxianion hole to stabilise the tetrahedral intermediate anion formed during proteolysis additionally it may allow for insertion or positioning of a substrate which would suffer from steric hindrance if it could not occupy the hole such as bpg in hemoglobin enzymes that catalyse multi step reactions can have multiple oxyanion holes that stabilise different transition states in the reaction
oxycephaly also known as turricephaly acrocephaly hypsicephaly oxycephalia steeple head tower head tower skull high head syndrome and turmschädel is a type of cephalic disorder where the top of the skull is pointed or conical due to premature closure of the coronal suture plus any other suture like the lambdoid or it may be used to describe the premature fusion of all sutures it should be differentiated from crouzon syndrome oxycephaly is the most severe of the craniosynostoses
oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen o 2 at increased partial pressures it is also known as oxygen toxicity syndrome oxygen intoxication and oxygen poisoning historically the central nervous system condition was called the paul bert effect and the pulmonary condition the lorrain smith effect after the researchers who pioneered its discovery and description in the late 19 th century severe cases can result in cell damage and death with effects most often seen in the central nervous system lungs and eyes oxygen toxicity is a concern for underwater divers those on high concentrations of supplemental oxygen particularly premature babies and those undergoing hyperbaric oxygen therapy the result of breathing increased partial pressures of oxygen is hyperoxia an excess of oxygen in body tissues the body is affected in different ways depending on the type of exposure central nervous system toxicity is caused by short exposure to high partial pressures of oxygen at greater than atmospheric pressure pulmonary and ocular toxicity result from longer exposure to increased oxygen levels at normal pressure symptoms may include disorientation breathing problems and vision changes such as myopia prolonged exposure to above normal oxygen partial pressures or shorter exposures to very high partial pressures can cause oxidative damage to cell membranes collapse of the alveoli in the lungs retinal detachment and seizures oxygen toxicity is managed by reducing the exposure to increased oxygen levels studies show that in the long term a robust recovery from most types of oxygen toxicity is possible protocols for avoidance of the effects of hyperoxia exist in fields where oxygen is breathed at higher than normal partial pressures including underwater diving using compressed breathing gases hyperbaric medicine neonatal care and human spaceflight these protocols have resulted in the increasing rarity of seizures due to oxygen toxicity with pulmonary and ocular damage being mainly confined to the problems of managing premature infants in recent years oxygen has become available for recreational use in oxygen bars the us food and drug administration has warned those suffering from problems such as heart or lung disease not to use oxygen bars scuba divers use breathing gases containing up to 100 oxygen and should have specific training in using such gases
in diving the oxygen window is the difference between the partial pressure of oxygen ppo 2 in arterial blood and the ppo 2 in body tissues it is caused by metabolic consumption of oxygen the term oxygen window was first used by albert r behnke in 1967 behnke refers to early work by momsen on partial pressure vacancy ppv where he used partial pressures of oxygen and helium as high as 2 – 3 ata to create a maximal ppv behnke then goes on to describe isobaric inert gas transport or inherent unsaturation as termed by lemessurier and hills and separately by hills who made their independent observations at the same time van liew et al also made a similar observation that they did not name at the time the clinical significance of their work was later shown by sass the oxygen window effect in decompression is described in diving medical texts and the limits reviewed by van liew et al in 1993 van liew et al describe the measurements important to evaluating the oxygen window as well as simplify the assumptions available for the existing complex anatomical and physiological situation to provide calculations over a wide range of exposures of the oxygen window
oxymercuration followed by reductive demercuration is called an oxymercuration – reduction reaction or oxymercuration – demercuration reaction this reaction which is almost always done in practice instead of oxymercuration is treated at the conclusion of the article
the ozone depletion potential odp of a chemical compound is the relative amount of degradation to the ozone layer it can cause with trichlorofluoromethane r 11 or cfc 11 being fixed at an odp of 1 0 chlorodifluoromethane r 22 for example has an odp of 0 05 cfc 11 or r 11 has the maximum potential amongst chlorocarbons because of the presence of three chlorine atoms in the molecule the first proposal of odp came from wuebbles in 1983 it was defined as a measure of destructive effects of a substance compared to a reference substance precisely odp of a given substance is defined as the ratio of global loss of ozone due to given substance over the global loss of ozone due to cfc 11 of the same mass odp can be estimated from the structure of a given substance chlorofluorocarbons have odps roughly equal to 1 brominated substances have usually higher odps in range 5 15 because of more aggressive bromine reaction with ozone hydrochlorofluorocarbons have odps mostly in range 0 005 0 2 due to the presence of the hydrogen which causes them to react readily in the troposphere therefore reducing their chance to reach the stratosphere hydrofluorocarbons hfc have no chlorine content so their odp is essentially zero odp is often used in conjunction with a compound s global warming potential gwp as a measure of how environmentally detrimental it can be gwp represents the potential of a substance to contribute to global warming in a broad sense haloalkanes that contain no hydrogen are stable in the troposphere and decompose only in the stratosphere those compounds that contain hydrogen also react with oh radicals and can therefore be decomposed in the troposphere as well the ozone depletion potential increases with the heavier halogens since the c x bond strength is lower note the trend of the cclf 2 x series in the table below
ozonolysis is an organic reaction where the unsaturated bonds of alkenes alkynes or azo compounds are cleaved with ozone alkenes and alkynes form organic compounds in which the multiple carbon – carbon bond has been replaced by a carbonyl group while azo compounds form nitrosamines the outcome of the reaction depends on the type of multiple bond being oxidized and the work up conditions
in mathematics a p adic zeta function or more generally a p adic l function is a function analogous to the riemann zeta function or more general l functions but whose domain and target are p adic where p is a prime number for example the domain could be the p adic integers zp a profinite p group or a p adic family of galois representations and the image could be the p adic numbers qp or its algebraic closure the source of a p adic l function tends to be one of two types the first source — from which tomio kubota and heinrich wolfgang leopoldt gave the first construction of a p adic l function — is via the p adic interpolation of special values of l functions for example kubota – leopoldt used kummer s congruences for bernoulli numbers to construct a p adic l function the p adic riemann zeta function ζp s whose values at negative odd integers are those of the riemann zeta function at negative odd integers up to an explicit correction factor p adic l functions arising in this fashion are typically referred to as analytic p adic l functions the other major source of p adic l functions — first discovered by kenkichi iwasawa — is from the arithmetic of cyclotomic fields or more generally certain galois modules over towers of cyclotomic fields or even more general towers a p adic l function arising in this way is typically called an arithmetic p adic l function as it encodes arithmetic data of the galois module involved the main conjecture of iwasawa theory now a theorem due to barry mazur and andrew wiles is the statement that the kubota – leopoldt p adic l function and an arithmetic analogue constructed by iwasawa theory are essentially the same in more general situations where both analytic and arithmetic p adic l functions are constructed or expected the statement that they agree is called the main conjecture of iwasawa theory for that situation such conjectures represent formal statements concerning the philosophy that special values of l functions contain arithmetic information
in mathematics the p adic gamma function γp s is a function of a p adic variable s analogous to the gamma function it was first explicitly defined by though pointed out that implicitly used the same function defined a p adic analog gp s of log γ s had previously given a definition of a different p adic analogue of the gamma function but his function does not have satisfactory properties and is not used much
p factor also known as asymmetric blade effect and asymmetric disc effect is an aerodynamic phenomenon experienced by a moving propeller that is responsible for the asymmetrical relocation of the propeller s center of thrust when an aircraft is at a high angle of attack this shift in the location of the center of thrust will exert a yawing moment on the aircraft causing it to yaw slightly to one side a rudder input is required to counteract the yawing tendency
in frequentist statistics the p value is a function of the observed sample results a test statistic relative to a statistical model which measures how extreme the observation is statistical hypothesis testing making use of p values are commonly used in many fields of science and social sciences such as economics political science psychology biology criminal justice and criminology and sociology their misuse has been a matter of considerable controversy
pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections pandas describes a hypothesis that there exists a subset of children with rapid onset of obsessive compulsive disorder ocd or tic disorders and these symptoms are caused by group a beta hemolytic streptococcal gabhs infections the proposed link between infection and these disorders is that an initial autoimmune reaction to a gabhs infection produces antibodies that interfere with basal ganglia function causing symptom exacerbations it has been proposed that this autoimmune response can result in a broad range of neuropsychiatric symptoms the pandas hypothesis was based on observations in clinical case studies at the us national institutes of health and in subsequent clinical trials where children appeared to have dramatic and sudden ocd exacerbations and tic disorders following infections there is supportive evidence for the link between streptococcus infection and onset in some cases of ocd and tics but proof of causality has remained elusive the pandas hypothesis is controversial whether it is a distinct entity differing from other cases of tourette syndrome ts ocd is debated pandas has not been validated as a disease entity it is not listed as a diagnosis by the international statistical classification of diseases and related health problems icd or the diagnostic and statistical manual of mental disorders dsm
papa syndrome is an acronym for pyogenic arthritis pyoderma gangrenosum and acne it is a rare genetic disorder characterised by its effects on skin and joints
pasli disease is a rare genetic disorder of the immune system pasli stands for “ p 110 delta activating mutation causing senescent t cells lymphadenopathy and immunodeficiency ” the immunodeficiency manifests as recurrent infections usually starting in childhood these include bacterial infections of the respiratory system and chronic viremia due to epstein barr virus ebv and or cytomegalovirus cmv individuals with pasli disease also have an increased risk of ebv associated lymphoma investigators carrie lucas michael lenardo and gulbu uzel at the national institute of allergy and infectious diseases at the u s national institutes of health and sergey nejentsev at the university of cambridge uk simultaneously described a mutation causing this condition which they called activated pi 3 k delta syndrome apds
pbkdf 2 password based key derivation function 2 is part of rsa laboratories public key cryptography standards pkcs series specifically pkcs 5 v 2 0 also published as internet engineering task force s it replaces an earlier key derivation function pbkdf 1 which could only produce derived keys up to 160 bits long
the pco 2 is the partial pressure of carbon dioxide co 2 in the blood usually the arterial blood is the relevant context the symbol for pco 2 in arterial blood is paco 2 measurement of paco 2 in the systemic circulation indicates the effectiveness of ventilation at the lungs alveoli given the diffusing capacity of the gas it is a good indicator of respiratory function and the closely related factor of acid – base homeostasis reflecting the amount of acid in the blood without lactic acid
peho syndrome is a progressive encephalopathy with edema hypsarrhythmia and optic atrophy it is a very rare disease one of the finnish heritage diseases and has been reported also in dutch and swiss infants it has been suggested that it may also be present in australian and american populations
pelvis syndrome is a congenital condition characterized by perineal hemangioma external genitalia malformations lipomyelomeningocele vesicorenal abnormalities imperforate anus and skin tag
posterior fossa malformations – hemangiomas – arterial anomalies – cardiac defects – eye abnormalities – sternal cleft and supraumbilical raphe syndrome also known as phaces syndrome is a cutaneous condition characterized by multiple congenital abnormalities phace syndrome should be considered in infants with large plaque type facial hemangiomas children presenting with this dermatologic manifestation should receive careful ophthalmologic cardiac and neurologic assessment according to one study in infants with large hemagiomas one third have extracutaneous manifestations consistent with the diagnosis of phace syndrome the most common are cerebrovascular and cardiovascular anomalies
pjw hash function is a non cryptographic hash function created by peter j weinberger of at t bell labs
poems syndrome also known as crow – fukase syndrome takatsuki disease or pep syndrome is a rare medical syndrome it is defined as the combination of a plasma cell proliferative disorder typically myeloma polyneuropathy and effects on many other organ systems it begins in middle age – the average age at onset is 50 – and affects up to twice as many men as women
in complexity theory pp is the class of decision problems solvable by a probabilistic turing machine in polynomial time with an error probability of less than 1 2 for all instances the abbreviation pp refers to probabilistic polynomial time the complexity class was defined by gill in 1977 if a decision problem is in pp then there is an algorithm for it that is allowed to flip coins and make random decisions it is guaranteed to run in polynomial time if the answer is yes the algorithm will answer yes with probability more than 1 2 if the answer is no the algorithm will answer yes with probability less than or equal to 1 2 in more practical terms it is the class of problems that can be solved to any fixed degree of accuracy by running a randomized polynomial time algorithm a sufficient but bounded number of times an alternative characterization of pp is the set of problems that can be solved by a nondeterministic turing machine in polynomial time where the acceptance condition is that a majority more than half of computation paths accept because of this some authors have suggested the alternative name majority p
puva induced acrobullous dermatosis is a cutaneous condition characterized by the sudden occurrence of tense blisters usually on the distal extremities during long term puva therapy
a puva keratosis is a precancerous keratotic skin lesion that arises from exposure to psoralen plus ultraviolet a light therapy
puva lentigines are a cutaneous condition caused by puva therapy
the p versus np problem is a major unsolved problem in computer science informally speaking it asks whether every problem whose solution can be quickly verified by a computer can also be quickly solved by a computer the first mention of the underlying problem occurred in a 1956 letter written by kurt gödel to john von neumann gödel asked whether theorem proving now known to be co np complete could be solved in quadratic or linear time the precise statement of the p versus np problem was introduced in 1971 by stephen cook in his seminal paper the complexity of theorem proving procedures and is considered by many to be the most important open problem in the field it is one of the seven millennium prize problems selected by the clay mathematics institute to carry a us 1 000 000 prize for the first correct solution the informal term quickly used above means the existence of an algorithm solving the task that runs in polynomial time such that the time to complete the task varies as a polynomial function on the size of the input to the algorithm as opposed to say exponential time the general class of questions for which some algorithm can provide an answer in polynomial time is called class p or just p for some questions there is no known way to find an answer quickly but if one is provided with information showing what the answer is it is possible to verify the answer quickly the class of questions for which an answer can be verified in polynomial time is called np which stands for nondeterministic polynomial time consider the subset sum problem an example of a problem that is easy to verify but whose answer may be difficult to compute given a set of integers does some nonempty subset of them sum to 0 for instance does a subset of the set − 2 − 3 15 14 7 − 10 add up to 0 the answer yes because the subset − 2 − 3 − 10 15 adds up to zero can be quickly verified with three additions there is no known algorithm to find such a subset in polynomial time there is one however in exponential time which consists of 2 n n 1 tries but such an algorithm exists if p np hence this problem is in np quickly checkable but not necessarily in p quickly solvable an answer to the p np question would determine whether problems that can be verified in polynomial time like the subset sum problem can also be solved in polynomial time if it turned out that p ≠ np it would mean that there are problems in np such as np complete problems that are harder to compute than to verify they could not be solved in polynomial time but the answer could be verified in polynomial time aside from being an important problem in computational theory a proof either way would have profound implications for mathematics cryptography algorithm research artificial intelligence game theory multimedia processing philosophy economics and many other fields
the paal – knorr synthesis in organic chemistry is a reaction that generates either furans pyrroles or thiophenes from 1 4 diketones it is a synthetically valuable method for obtaining substituted furans and pyrroles common structural components of many natural products it was initially reported independently by german chemists carl paal and ludwig knorr in 1884 as a method for the preparation of furans and has been adapted for pyrroles and thiophenes although the paal – knorr synthesis has seen widespread use the mechanism wasn t fully understood until it was elucidated by v amarnath et al in the 1990 s the furan synthesis requires an acid catalyst paal – knorr furan synthesis in the pyrrole synthesis a primary amine participates paal – knorr pyrrole synthesis and in that of thiophene for instance the compound phosphorus pentasulfide paal knorr thiophene synthesis
pacemaker failure is the inability of an implanted artificial pacemaker to perform its intended function of regulating the beating of the heart it is defined by the requirement of repeat surgical pacemaker related procedure after the initial implantation a study of pacemaker failure in oregon in the 1970 s indicates that 10 of implanted pacemakers failed within the first month causes of pacemaker failure included lead related failure lead migration lead fracture ventricular perforation unit malfunction battery failure or component malfunction problems at the insertion site infections tissue breakdown battery pack migration failures related to exposure to high voltage electricity or high intensity microwaves and a miscellaneous category one patient had ventricular tachycardia when using his electric razor and another patient had persistent pacing of the diaphragm muscle
in the pacemaking cells of the heart e g the sinoatrial node the pacemaker potential also called the pacemaker current is the slow positive increase in voltage across the cell s membrane the membrane potential that occurs between the end of one action potential and the beginning of the next action potential this increase in membrane potential is what causes the cell membrane which typically maintains a resting membrane potential of 70 mv to reach the threshold potential and consequently fire the next action potential thus the pacemaker potential is what drives the self generated rhythmic firing automaticity of pacemaker cells and the rate of change i e the slope of the pacemaker potential is what determines the timing of the next action potential and thus the intrinsic firing rate of the cell in a healthy sinoatrial node san a complex tissue within the right atrium containing pacemaker cells that normally determine the intrinsic firing rate for the entire heart the pacemaker potential is the main determinant of the heart rate because the pacemaker potential represents the non contracting time between heart beats diastole it is also called the diastolic depolarization the amount of net inward current required to move the cell membrane potential during the pacemaker phase is extremely small in the order of few pas but this net flux arises from time to time changing contribution of several currents that flow with different voltage and time dependence evidence in support of the active presence of k ca 2 na channels and na k exchanger during the pacemaker phase have been variously reported in the literature but several indications point to the “ funny ” if current as one of the most important see funny current there is now substantial evidence that also sarcoplasmic reticulum sr ca 2 transients participate to the generation of the diastolic depolarization via a process involving the na – ca exchanger
pacemaker syndrome is a disease that represents the clinical consequences of suboptimal atrioventricular av synchrony or av dyssynchrony regardless of the pacing mode after pacemaker implantation it is an iatrogenic disease — an adverse effect resulting from medical treatment — that is often underdiagnosed in general the symptoms of the syndrome are a combination of decreased cardiac output loss of atrial contribution to ventricular filling loss of total peripheral resistance response and nonphysiologic pressure waves individuals with a low heart rate prior to pacemaker implantation are more at risk of developing pacemaker syndrome normally the first chamber of the heart atrium contracts as the second chamber ventricle is relaxed allowing the ventricle to fill before it contracts and pumps blood out of the heart when the timing between the two chambers goes out of synchronization less blood is delivered on each beat patients who develop pacemaker syndrome may require adjustment of the pacemaker or fitting of another lead to better coordinate the timing of atrial and ventricular contraction
pachyderma or pachydermia is the thickening of skin like that of a pachyderm it occurs in the condition pachydermoperiostosis an x linked genetic disorder
pachydermatous eosinophilic dermatitis is a cutaneous condition observed in south african black teenage girls and characterized by generalized pruritic papules hypertrophic genital lesions and peripheral eosinophilia
pachygyria from the greek pachy meaning thick or fat gyri is a congenital malformation of the cerebral hemisphere it results in unusually thick convolutions of the cerebral cortex typically children have developmental delay and seizures the onset and severity depending on the severity of the cortical malformation infantile spasms are common in affected children as is intractable epilepsy
pachyonychia congenita is an autosomal dominant skin disorder
pachyostosis is a non pathological condition in vertebrate animals in which the bones experience a thickening generally caused by extra layers of lamellar bone it often occurs together with bone densification osteosclerosis reducing inner cavities this joint occurrence is called pachyosteosclerosis however especially in the older literature “ pachyostosis ” is often used loosely referring to all osseous specializations characterized by an increase in bone compactness and or volume it occurs in both terrestrial and especially aquatic or semi aquatic vertebrates in aquatic animals such as seacows manatees and dugongs thalassocnus and plesiosaurs it provides or provided ballast as an adaptation for an aquatic existence most giant deer showed pronounced pachyostosis of the mandible and skull it has been suggested that this served to store minerals for antler growth many pachycephalosauria and most members of the dinocephalia clade of therapsids had thickened skull bones probably used in head butting contests
the pacific naval force fuerza naval del pacífico is the mexican navy s presence in the pacific ocean its headquarters is based in manzanillo colima the pacific naval force was created in the same date as its gulf of mexico and caribbean sea counterpart on february 11 1972 the surface ships are the main components of the naval force and is the means to secure and to operate sea control in strategic areas main objectives of the naval force is to defend the sovereignty and integrity of mexico from sea protect vital naval installations protect human life and maintain marine traffic and maintain the rule of law in national waters
the pacific decadal oscillation pdo is a robust recurring pattern of ocean atmosphere climate variability centered over the mid latitude pacific basin the pdo is detected as warm or cool surface waters in the pacific ocean north of 20 ° n over the past century the amplitude of this climate pattern has varied irregularly at interannual to interdecadal time scales there is evidence of reversals in the prevailing polarity of the oscillation occurring around 1925 1947 and 1977 the last two reversals corresponded with dramatic shifts in salmon production regimes in the north pacific ocean this climate pattern also affects coastal sea and continental surface air temperatures from alaska to california during a warm or positive phase the west pacific becomes cooler and part of the eastern ocean warms during a cool or negative phase the opposite pattern occurs the pacific decadal oscillation was named by steven r hare who noticed it while studying salmon production pattern results in 1997 the pacific decadal oscillation index is the leading empirical orthogonal function eof of monthly sea surface temperature anomalies sst a over the north pacific poleward of 20 ° n after the global average sea surface temperature has been removed this pdo index is the standardized principal component time series a pdo signal has been reconstructed to 1661 through tree ring chronologies in the baja california area
in computer networking packet delay variation pdv is the difference in end to end one way delay between selected packets in a flow with any lost packets being ignored the effect is sometimes referred to as jitter although the definition is an imprecise fit
packing problems are a class of optimization problems in mathematics that involve attempting to pack objects together into containers the goal is to either pack a single container as densely as possible or pack all objects using as few containers as possible many of these problems can be related to real life packaging storage and transportation issues each packing problem has a dual covering problem which asks how many of the same objects are required to completely cover every region of the container where objects are allowed to overlap in a packing problem you are given containers usually a single two or three dimensional convex region or an infinite space a set of objects some or all of which must be packed into one or more containers the set may contain different objects with their sizes specified or a single object of a fixed dimension that can be used repeatedly usually the packing must be without overlaps between goods and other goods or the container walls in some variants the aim is to find the configuration that packs a single container with the maximal density more commonly the aim is to pack all the objects into as few containers as possible in some variants the overlapping of objects with each other and or with the boundary of the container is allowed but should be minimized
pacman dysplasia alternatively known as epiphyseal stippling with osteoclastic hyperplasia is a lethal autosomal recessive skeletal dysplasia the dysplasia is present during fetal development
the active agent is commonly referred to as pederin although depending on the beetle species it may be one of several similar molecules including pederone and pseudopederin blister beetle dermatitis a term more properly used for the different dermatitis caused by cantharidin from blister beetles is also sometimes used to describe paederus dermatitis caused by rove beetles
in computing page zooming is the ability to zoom in and out a document or image at page level it is usually found in applications related to document layout and publishing e g word processing and spreadsheet programs but it can also be found in web browsers as it improves accessibility for people with visual impairment and people using mobile devices such as pdas and mobiles which have a relatively small screen
a paget s abscess named by eminent british surgeon and pathologist sir james paget is an abscess that recurs at the site of a former abscess which had resolved
paget s disease of bone also termed ambiguously just paget s disease paget s is caused by the excessive breakdown and formation of bone followed by disorganized bone remodeling this causes affected bone to weaken resulting in pain misshapen bones fractures and arthritis in the joints near the affected bones rarely it can develop into a primary bone cancer known as paget s sarcoma often paget s disease is localized to only a few bones in the body the pelvis femur and lower lumbar vertebrae are the most commonly affected bones paget s disease typically is localized affecting just one or a few bones as opposed to osteoporosis for example which usually affects all the bones in the body a later phase of the disease is characterized by the replacement of normal bone marrow with highly vascular fibrous tissue because early diagnosis and treatment is important after age 40 siblings and children of someone with paget s disease should have an alkaline phosphatase blood test every two or three years if the alkaline phosphatase level is above normal other tests such as a bone specific alkaline phosphatase test bone scan or x ray can be performed decisions about treating paget s disease may be complicated as the disease often affects people differently in addition to this it is sometimes difficult to predict whether a person with paget s disease who shows no signs or symptoms of the disorder will develop symptoms or complications such as a bone fracture in the future although there is no cure for paget s disease medications bisphosphonates and calcitonin can help control the disorder and lessen pain and other symptoms medications are often successful in controlling the disorder especially when started before complications begin paget s disease affects from 1 5 to 8 0 percent of the population depending on age and country of residence paget s disease is rare in people less than 55 years of age men are more commonly affected than women 3 2 the disease is named after sir james paget
paget s disease of the breast or paget disease of the breast ˈpædʒᵻt rhymes with gadget also known as paget s disease of the nipple is a malignant condition that outwardly may have the appearance of eczema with skin changes involving the nipple of the breast the condition is an uncommon disease accounting for 1 to 4 3 of all breast cancers and was first described by sir james paget in 1874 the condition in itself often appears innocuous limited to a surface appearance and it is sometimes dismissed although actually indicative of underlying breast cancer
pagetoid reticulosis also known as acral mycoses fungoides localized epidermotropic reticulosis mycosis fungoides palmaris et plantaris unilesional mycosis fungoides and woringer – kolopp disease is a cutaneous condition an uncommon lymphoproliferative disorder sometimes considered a form of mycosis fungoides
paget – schroetter disease also known as paget – von schrötter disease is a form of upper extremity deep vein thrombosis dvt a medical condition in which blood clots form in the deep veins of the arms these dvts typically occur in the axillary or subclavian veins
pagophagy or pagophagia is eating of ice the term has the two major usages an eating disorder a particular case of pica normal feeding behavior of some animals the pagophagic disorder is among the unexplained clinical signs of iron deficiency anemia
paid is blood is a 1971 spaghetti western directed by luigi batzella the original italian title of the film was quelle sporche anime dannate
pain asymbolia also called pain dissociation is a condition in which pain is experienced without unpleasantness this usually results from injury to the brain lobotomy cingulotomy or morphine analgesia preexisting lesions of the insula may abolish the aversive quality of painful stimuli while preserving the location and intensity aspects typically patients report that they have pain but are not bothered by it they recognize the sensation of pain but are mostly or completely immune to suffering from it
pain disorder is chronic pain experienced by a patient in one or more areas and is thought to be caused by psychological stress the pain is often so severe that it disables the patient from proper functioning duration may be as short as a few days or as long as many years the disorder may begin at any age and occurs more frequently in girls than boys this disorder often occurs after an accident or during an illness that has caused pain which then takes on a life of its own
pain is an aversive sensation and feeling associated with actual or potential tissue damage it is widely accepted by a broad spectrum of scientists and philosophers that non human animals can perceive pain including pain in amphibians pain is a complex mental state with a distinct perceptual quality but also associated with suffering which is an emotional state because of this complexity the presence of pain in non human animals cannot be determined unambiguously using observational methods but the conclusion that animals experience pain is often inferred on the basis of likely presence of phenomenal consciousness which is deduced from comparative brain physiology as well as physical and behavioural reactions amphibians particularly anurans fulfill several physiological and behavioural criteria proposed as indicating that non human animals may experience pain these fulfilled criteria include a suitable nervous system and sensory receptors opioid receptors and reduced responses to noxious stimuli when given analgesics and local anaesthetics physiological changes to noxious stimuli displaying protective motor reactions exhibiting avoidance learning and making trade offs between noxious stimulus avoidance and other motivational requirements pain in amphibians has societal implications including their exposure to pollutants preparation for cuisine e g frogs legs and amphibians used in scientific research several scientists and scientific groups have expressed the belief that amphibians can feel pain however this remains somewhat controversial due to differences in brain structure and the nervous system compared with other vertebrates
pain wind up is the perceived increase in pain intensity over time when a given stimulus is delivered repeatedly above a critical rate it is caused by repeated stimulation of group c peripheral nerve fibers leading to progressively increasing electrical response in the corresponding spinal cord posterior horn neurons
painful bruising syndrome also known as autoerythrocyte sensitization gardner – diamond syndrome and psychogenic purpura is an idiopathic trauma induced condition seen in young to middle aged women who sometimes manifest personality disorders it is characterized by a distinctive localized purpuric reaction occurring primarily on the legs face and trunk with recurring painful ecchymoses variably accompanied by syncope nausea vomiting gastrointestinal and intracranial bleeding patients with autoerythrocyte sensitization can suffer frequent painful bruising around joints and muscles because of the rarity of the disorder there are few methods of support in place for patients many patients are labelled with the stigma of having a psychological condition without this having a specifically proven link there have been cases of painful bruising syndrome reported where there are no additional psychological disorders this has been known to be put into remission with chemotherapy it was characterized in 1955 by frank gardner and louis diamond patient may present with a history of intermittent purpura mostly precipitated by stress
painful fat herniation also known as painful piezogenic pedal papules and piezogenic papules is a rare cause of painful feet due to fat herniations through the thin fascial layers of the weight bearing parts of the heel
in physics a pair potential is a function that describes the potential energy of two interacting objects examples of pair potentials include the coulomb s law in electrodynamics newton s law of universal gravitation in mechanics the lennard jones potential and the morse potential pair potentials are very common in physics exceptions are very rare an example of a potential energy function that is not a pair potential is the three body axilrod teller potential another example is the stillinger weber potential for silicon which includes the angle in atriangle of silicon atoms as a parameter
paleodictyon is a pattern usually interpreted to be a burrow which appears in the geologic marine record beginning in the precambrian early cambrian and in modern ocean environments paleodictyon were first described by giuseppe meneghini in 1850
palilalia from the greek πάλιν pálin meaning again and λαλιά laliá meaning speech or to talk a complex tic is a speech disorder characterized by the involuntary repetition of syllables words or phrases it has features resembling other complex tics such as echolalia or coprolalia but unlike other aphasias palilalia is based upon contextually correct speech it was originally described by alexandre achille souques in a patient with stroke leading to left side hemiplegia although a condition described as auto echolalia in 1899 by édouard brissaud may have been the same condition
palindromic rheumatism pr consists of sudden and rapidly developing attacks of arthritis there is acute pain redness swelling and disability of one usually or multiple joints the interval between recurrent attacks is extremely variable and how long the attack lasts is also variable attacks may last from few hours to days attacks may become more frequent with time there is no joint damage after attacks
palinopsia greek palin for again and opsia for seeing is a visual disturbance defined as the persistent recurrence of a visual image after the stimulus has been removed palinopsia is not a diagnosis but a broad term that describes a heterogeneous group of pathological visual symptoms with a wide variety of etiologies visual perseveration is synonymous with palinopsia in 2014 gersztenkorn and lee comprehensively reviewed all cases of palinopsia in the literature and subdivided it into two clinically relevant groups illusory palinopsia and hallucinatory palinopsia hallucinatory palinopsia usually due to seizures or posterior cortical lesions describes afterimages that are formed long lasting and high resolution illusory palinopsia usually due to migraines head trauma prescription drugs or hallucinogen persisting perception disorder hppd describes afterimages that are affected by ambient light and motion and are unformed indistinct or low resolution
palisaded encapsulated neuroma is a cutaneous condition characterized by skin colored or pink rubbery firm papules or nodules
palisaded neutrophilic and granulomatous dermaititis is usually associated with a well defined connective tissue disease lupus erythematosus or rheumatoid arthritis most commonly and often presents with eroded or ulcerated symmetrically distributed umbilicated papules or nodules on the elbows
pallister – hall syndrome is a disorder that affects the development of many parts of the body it is named for judith hall and philip pallister
pallister – killian syndrome also tetrasomy 12 p mosaicism or pallister mosaic aneuploidy syndrome is an extremely rare genetic disorder occurring in humans pallister killian occurs due to the presence of the anomalous extra isochromosome 12 p the short arm of the twelfth chromosome this leads to the development of tetrasomy 12 p because not all cells have the extra isochromosome pallister killian is a mosaic condition more readily detected in skin fibroblasts it was first described by philip pallister in 1977 and further researched by maria teschler nicola and wolfgang killian in 1981
a palmar crease is a type of crease on the palm a single transverse palmar crease is sometimes associated with down syndrome though other physical symptoms manifest with this relatively rare syndrome other types of creases include the sydney crease and the suwon or double transverse palmar crease
palmar erythema is reddening of the palms at the thenar and hypothenar eminences
palmoplantar hyperhidrosis is excessive sweating localized to the palms of the hands and soles of the feet it is a form of focal hyperhidrosis in that the excessive sweating is limited to a specific region of the body as with other types of focal hyperhidrosis e g axillary craniofacial the sweating tends to worsen during warm weather
palmoplantar keratodermas are a heterogeneous group of disorders characterized by abnormal thickening of the palms and soles autosomal recessive and dominant x linked and acquired forms have all been described
palpable purpura is a condition where purpura which constitutes visible non blanching hemorrhages are raised and able to be touched or felt upon palpation
palpitation is a perceived abnormality of the heartbeat characterized by awareness of heart muscle contractions in the chest hard beats fast beats irregular beats and or pauses it is both a symptom reported by the patient and a medical diagnosis palpitation is frequently associated with anxiety and does not necessarily indicate a structural or functional abnormality of the heart but it can be a symptom arising from an objectively rapid or irregular heartbeat palpitation can be intermittent and of variable frequency and duration or continuous associated symptoms include dizziness shortness of breath sweating headaches and chest pain palpitation may be associated with coronary heart disease hyperthyroidism diseases affecting cardiac muscle such as hypertrophic cardiomyopathy diseases causing low blood oxygen such as asthma and emphysema kidney disease low levels of brain serotonin blood loss and pain drugs such as antidepressants alcohol nicotine caffeine cocaine and amphetamines electrolyte imbalances of magnesium potassium and calcium and deficiencies of nutrients such as taurine arginine and iron
panama disease is a plant disease of the roots of banana plants it is a type of fusarium wilt caused by the fungal pathogen fusarium oxysporum the pathogen is resistant to fungicide and cannot be controlled chemically during the 1950 s panama disease wiped out the gros michel banana everywhere except asia the gros michel banana was the dominant cultivar of bananas and the blight inflicted enormous costs and forced producers to switch to other disease resistant cultivars new strains of panama disease currently threaten the production of today s most popular cultivar cavendish
panayiotopoulos syndrome is a common idiopathic childhood related seizure disorder that occurs exclusively in otherwise normal children idiopathic epilepsy and manifests mainly with autonomic epileptic seizures and autonomic status epilepticus an expert consensus has defined panayiotopoulos syndrome as a benign age related focal seizure disorder occurring in early and mid childhood it is characterized by seizures often prolonged with predominantly autonomic symptoms and by an eeg electroencephalogram that shows shifting and or multiple foci often with occipital predominance
pancake sentences are a phenomenon in scandinavian linguistics where sentence agreement does not follow conventional linguistic patterns the phrase appears to have been coined by hans olav enger in a 2004 academic paper scandinavian pancake sentences as semantic agreement enger states that pancake sentences are where the predicative adjective apparently disagrees with its subject this phenomenon may be related or compared to english language linguistics where american english speakers might say the team has arrived syntactically agreeing the singular team versus british english speakers saying the team have arrived agreeing semantically to the collective noun team an example from swedish is the sentence pannkakor är nyttigt while pannkakor pancakes is plural and of common gender nyttigt healthy is inflected to singular and neuter a similar phenomenon also occurs in hebrew where the copula and adjectives appear to disagree with the subject as well as is portuguese with some nouns used without the article água é bom é proibido entrada está proibido brincadeiras when feminine nouns of either number agree with a masculine adjective in its singular form
pancake syndrome is a disease in which a person gets symptoms after eating food contaminated with particular mites the disease name comes from reports of people becoming ill after eating pancakes made from contaminated flour mites suspected as causing the condition are dermatophagoides pteronyssinus blomia tropicalis and suidasia pontifica the latter two are the most likely to have caused the harmful effects and they live in tropical and subtropical environments because the disease is transmitted by pancakes and other cooked food scientists expect that this means that the pathogen can survive the heat of cooking storing flour at low temperature in a freezer could prevent contamination or kill existing mites in the flour anaphylaxis can occur during exposure to nsaid drugs or exercise to those exposed to the mites
a pancoast tumor also called a pulmonary sulcus tumor or superior sulcus tumor is a tumor of the pulmonary apex it is a type of lung cancer defined primarily by its location situated at the top end of either the right or left lung it typically spreads to nearby tissues such as the ribs and vertebrae most pancoast tumors are non small cell cancers the growing tumor can cause compression of a brachiocephalic vein subclavian artery phrenic nerve recurrent laryngeal nerve vagus nerve or characteristically compression of a sympathetic ganglion resulting in a range of symptoms known as horner s syndrome pancoast tumors are named for henry pancoast a us radiologist who described them in 1924 and 1932
pancreas or pancreatic divisum is a congenital anomaly in the anatomy of the ducts of the pancreas in which a single pancreatic duct is not formed but rather remains as two distinct dorsal and ventral ducts
a pancreas transplant is an organ transplant that involves implanting a healthy pancreas one that can produce insulin into a person who usually has diabetes because the pancreas is a vital organ losing all of the pancreas leaves a person with a very very serious case of total diabetes called brittle diabetes performing functions necessary in the digestion process the recipient s native pancreas is left in place and the donated pancreas is attached in a different location in the event of rejection of the new pancreas which would quickly cause life threatening diabetes there would be a significant chance the recipient would not survive very well for long without the native pancreas however dysfunctional still in place the healthy pancreas comes from a donor who has just died or it may be a partial pancreas from a living donor at present pancreas transplants are usually performed in persons with insulin dependent diabetes who can develop severe complications patients with the most common and deadliest form of pancreatic cancer pancreatic adenomas which are usually always malignant with a poor prognosis and high risk for metastasis as opposed to more treatable pancreatic neuroendocrine tumors or pancreatic insulinomas are usually not eligible for valuable pancreatic transplantations since the condition usually has a very high mortality rate and the disease which is usually highly malignant and detected too late to treat could and probably would soon return
pancreatic abscess is a late complication of acute necrotizing pancreatitis occurring more than 4 weeks after the initial attack a pancreatic abscess is a collection of pus resulting from tissue necrosis liquefaction and infection it is estimated that approximately 3 of the patients suffering from acute pancreatitis will develop an abscess according to the balthazar and ranson s radiographic staging criteria patients with a normal pancreas an enlargement that is focal or diffuse mild peripancreatic inflammations or a single collection of fluid pseudocyst have less than 2 chances of developing an abscess however the probability of developing an abscess increases to nearly 60 in patients with more than two pseudocysts and gas within the pancreas
pancreatic acinar metaplasia abbreviated pam is a common incidental histopathologic finding present in approximately 20 25 of patients undergoing an esophagogastroduodenoscopy
pancreatic cancer arises when cells in the pancreas a glandular organ behind the stomach begin to multiply out of control and form a mass these cancerous cells have the ability to invade other parts of the body there are a number of types of pancreatic cancer the most common pancreatic adenocarcinoma accounts for about 85 of cases and the term pancreatic cancer is sometimes used to refer only to that type these adenocarcinomas start within the part of the pancreas which makes digestive enzymes several other types of cancer which collectively represent the majority of the non adenocarcinomas can also arise from these cells 1 2 of cases of pancreatic cancer are neuroendocrine tumors which arise from the hormone producing cells of the pancreas these are generally less aggressive than pancreatic adenocarcinoma signs and symptoms of the most common form of pancreatic cancer may include yellow skin abdominal or back pain unexplained weight loss light colored stools dark urine and loss of appetite there are usually no symptoms in the disease s early stages and symptoms that are specific enough to suggest pancreatic cancer typically do not develop until the disease has reached an advanced stage by the time of diagnosis pancreatic cancer has often spread to other parts of the body pancreatic cancer rarely occurs before the age of 40 and more than half of cases of pancreatic adenocarcinoma occur in those over 70 risk factors for pancreatic cancer include tobacco smoking obesity diabetes and certain rare genetic conditions about 25 of cases are linked to smoking and 5 – 10 are linked to inherited genes pancreatic cancer is usually diagnosed by a combination of medical imaging techniques such as ultrasound or computed tomography blood tests and examination of tissue samples biopsy the disease is divided into stages from early stage i to late stage iv screening the general population has not been found to be effective the risk of developing pancreatic cancer is lower among non smokers and people who maintain a healthy weight and limit their consumption of red or processed meat a smoker s chance of developing the disease decreases if they stop smoking and almost returns to that of the rest of the population after 20 years pancreatic cancer can be treated with surgery radiotherapy chemotherapy palliative care or a combination of these treatment options are partly based on the cancer stage surgery is the only treatment that can cure pancreatic adenocarcinoma and may also be done to improve quality of life without the potential for cure pain management and medications to improve digestion are sometimes needed early palliative care is recommended even for those receiving treatment that aims for a cure in 2012 pancreatic cancers of all types were the seventh most common cause of cancer deaths resulting in 330 000 deaths globally pancreatic cancer is the fifth most common cause of death from cancer in the united kingdom and the fourth most common in the united states the disease occurs most often in the developed world where about 70 of the new cases in 2012 originated pancreatic adenocarcinoma typically has a very poor prognosis after diagnosis 25 of people survive one year and 5 live for five years for cancers diagnosed early the five year survival rate rises to about 20 neuroendocrine cancers have better outcomes at five years from diagnosis 65 of those diagnosed are living though survival varies considerably depending on the type of tumor
a pancreatic cyst is a fluid filled sac within the pancreas causes range from benign to malignant pancreatic pseudocysts can occur in the setting of pancreatitis though they are only reliable diagnosed 6 weeks after the episode of acute pancreatitis benign tumors such as serous cystadenomas can occur main branch intraductal papillary mucinous neoplasm ipmns are associated with dilatation of the main pancreatic duct while side branch ipmns are typically benign and not associated with dilatation mrcp can help distinguish the position of the cysts relative to the pancreatic duct and direct appropriate treatment and follow up the most common malignancy that can present as a pancreatic cyst is a mucinous cystic neoplasm
pancreatic diseases include
a pancreatic fistula is an abnormal communication between the pancreas and other organs due to leakage of pancreatic secretions from damaged pancreatic ducts an external pancreatic fistula is one that communicates with the skin and is also known as a pancreaticocutaneous fistula whereas an internal pancreatic fistula communicates with other internal organs or spaces pancreatic fistulas can be caused by pancreatic disease trauma or surgery
a pancreatic injury is some form of trauma sustained by the pancreas the injury can be sustained through either blunt forces such as a motor vehicle accident or penetrative forces such as that of a gunshot wound the pancreas is one of the least commonly injured organs in abdominal trauma
pancreatic mucinous cystadenoma also known as mucinous cystadenoma of the pancreas is a benign tumour of pancreas it is one of the cystic lesions of the pancreas
pancreatic mucinous cystic neoplasm also mucinous cystic neoplasm of the pancreas and mucinous cystic tumour is a grouping of cystic neoplasms that arise from the pancreas they may be benign malignant or in between the prognosis of this set of tumours is highly variable and dependent on the specific sub classification benign borderline malignant
pancreatic neuroendocrine tumors pannets pets or pnets often referred to as islet cell tumors or pancreatic endocrine tumors are neuroendocrine neoplasms that arise from cells of the endocrine hormonal and nervous system within the pancreas pannets are a type of neuroendocrine tumor representing about one third of gastroenteropancreatic neuroendocrine tumors gep nets many pannets are benign while some are malignant aggressive pannet tumors have traditionally been termed islet cell carcinoma pannets are quite distinct from the usual form of pancreatic cancer the majority of which are adenocarcinomas which arises in the exocrine pancreas only 1 or 2 of clinically significant pancreas neoplasms are pannets
the pancreatic notch is a separation between the neck of pancreas and the uncinate process of pancreas
pancreatic pleural effusion is pleural effusion or the appearance of excess fluid that accumulates between the two pleural layers as a result of pancreatic pathology about to 20 of people suffering from pancreatitis get pleural effusion mostly on the left side
a pancreatic pseudocyst is a circumscribed collection of fluid rich in pancreatic enzymes blood and necrotic tissue typically located in the lesser sac of the abdomen pancreatic pseudocysts are usually complications of pancreatitis although in children they frequently occur following abdominal trauma pancreatic pseudocysts account for approximately 75 of all pancreatic masses
the pancreatic tumors or pancreatic neoplasms are tumors arising in the pancreas there are several types which can be either benign or malignant pancreatic cancer
pancreaticobiliary maljunction is a congenital malformation in which the pancreatic and bile ducts join anatomically outside the duodenal wall
pancreatitis is inflammation of the pancreas the pancreas is a large organ behind the stomach that produces digestive enzymes there are two main types acute pancreatitis and chronic pancreatitis signs and symptoms of pancreatitis include pain in the upper abdomen nausea and vomiting the pain often goes into the back and is usually severe in acute pancreatitis a fever may occur and symptoms typically resolve in a few days in chronic pancreatitis weight loss fatty stool and diarrhea may occur complications may include infection bleeding diabetes mellitus or problems with other organs the most common causes of acute pancreatitis are gallstones and heavy alcohol use other causes include direct trauma certain medications infections such as mumps and tumors among others chronic pancreatitis may develop as a result of acute pancreatitis it is most commonly due to many years of heavy alcohol use other causes include high levels of blood fats high blood calcium some medications and certain genetic disorders such as cystic fibrosis among others smoking increases the risk of both acute and chronic pancreatitis diagnosis of acute pancreatitis is based on a threefold increase in the blood of either amylase or lipase in chronic pancreatitis these tests may be normal medical imaging such as ultrasound and ct scan may also be useful acute pancreatitis is usually treated with intravenous fluids pain medication and sometimes antibiotics typically no eating or drinking is allowed and a tube may be placed into the stomach a procedure known as a endoscopic retrograde cholangiopancreatography ercp may be done to open the pancreatic duct if blocked in those with gallstones the gallbladder is often also removed in chronic pancreatitis in addition to the above temporary feeding through a nasogastric tube may be used to provide adequate nutrition long term dietary changes and pancreatic enzyme replacement may be required and occasionally surgery is done to remove parts of the pancreas globally in 2013 about 17 million cases of pancreatitis occurred this resulted in 123 000 deaths up from 83 000 deaths in 1990 acute pancreatitis occurs in about 30 per 100 000 people a year new cases of chronic pancreatitis develop in about 8 per 100 000 people a year and currently affect about 50 per 100 000 people in the united states it is more common in men than women often chronic pancreatitis starts between the ages of 30 and 40 while it is rare in children acute pancreatitis was first described on autopsy in 1882 while chronic pancreatitis was first described in 1946
pancreatoblastoma is a rare type of pancreatic cancer it occurs mainly in childhood and has a relatively good prognosis
pancytopenia is a medical condition in which there is a reduction in the number of red and white blood cells as well as platelets if only two parameters from the full blood count are low the term bicytopenia can be used the diagnostic approach is the same as for pancytopenia
the pandemonium effect is a problem that may appear when high resolution detectors usually germanium detectors are used in beta decay studies it can affect the correct determination of the feeding to the different levels of the daughter nucleus it was first introduced in 1977
pangaré is a coat trait found in some horses that features pale hair around the eyes and muzzle and underside of the body these pale areas can extend up to the flanks throat and chest behind the elbows in front of the stifle and up the buttock animals with the pangaré trait are sometimes called mealy or light pointed the color of these lighter areas depends on the underlying color and ranges from off white to light tan this type of coloration is most often found in primitive breeds like the fjord horse exmoor pony american belgian draft and haflinger wild equids like the przewalski s horse onager african wild ass kiang as well as the domestic donkey exhibit pangaré as a rule pangaré is thought to be a type of protective countershading horse foals are often born with foal pangaré or light points especially over black haired areas which they lose when they shed their foal coats dr phillip sponenberg suggested that the seal brown coat color was caused by the action of pangaré on a black coat however seal brown horses have since tested negative for the recessive black genotype chestnut horses with pangaré are sometimes called belgian sorrels
panic is a sudden sensation of fear which is so strong as to dominate or prevent reason and logical thinking replacing it with overwhelming feelings of anxiety and frantic agitation consistent with an animalistic fight or flight reaction panic may occur singularly in individuals or manifest suddenly in large groups as mass panic closely related to herd behavior
panic attacks are sudden periods of intense fear that may include palpitations sweating shaking shortness of breath numbness or a feeling that something really bad is going to happen the maximum degree of symptoms occurs within minutes there may be a fear of losing control or chest pain panic attacks themselves are not dangerous panic attacks can occur due to number of disorders including panic disorder social anxiety disorder post traumatic stress disorder drug use depression and medical problems they can either be trigger or occur unexpectedly risks factors include smoking and psychological stress diagnosis should involve ruling out other conditions that can produce similar symptoms including hyperthyroidism hyperparathyroidism heart disease lung disease and drug use treatment of panic attacks should be directed at the underlying cause in those with frequent attacks counselling or medications may be used breathing training and muscle relaxation techniques may also help those affected are at a higher risk of suicide in europe about 3 of the population has a panic attack in a given year while in the united states they affect about 11 they are more common in females than males they often begin during puberty or early adulthood children and older people are less commonly affected
panic disorder is an anxiety disorder characterized by recurrent unexpected panic attacks panic attacks are sudden periods of intense fear that may include palpitations sweating shaking shortness of breath numbness or a feeling that something really bad is going to happen the maximum degree of symptoms occurs within minutes there may be ongoing worries about having further attacks and avoidance of places where attacks have occurred in the past the cause of panic disorder is unknown often it runs in families risk factors include smoking psychological stress and a history of child abuse diagnosis involves ruling out other potential causes including other mental disorders medical conditions such as heart disease or hyperthyroidism and drug use screening for the condition may be done using a questionnaire panic disorder is usually treated with counselling and medications the type of counselling used is typically cognitive behavioral therapy cbt which is effective in more than half of people medications used include antidepressants and occasionally benzodiazepines or beta blockers following stopping treatment up to 30 of people have a recurrence panic disorder affects about 2 5 of people at some point in their life it usually begins during adolescence or early adulthood but any age can be affected it is less common in children and older people women are more often affected than men
panmyelosis is a form of myelofibrosis it is part of the presentation in acute panmyelosis with myelofibrosis
panner disease is an osteochondrosis of the capitellum of the elbow it causes pain and stiffness in the affected elbow and may limit extension on radiographs the capitulum may appear irregular with areas of radioluceny treatment is symptomatic with a good prognosis it is primarily seen in children between five and ten years old the disease is named after the danish radiologist hans jessen panner 1871 – 1930 panner s disease is often caused by excessive throwing due to valgus stress aka little league elbow upon evaluation patients will have pain with an extension overload valgus test in the posteromedial elbow little leaguers elbow in seen in new league players with unaccustomed throwing which causes partial avulsion of the medial epicondyle
panniculitis is a group of diseases whose hallmark is inflammation of subcutaneous adipose tissue the fatty layer under the skin panniculus adiposus symptoms include tender skin nodules and systemic signs such as weight loss and fatigue restated an inflammatory disorder primarily localized in the subcutaneous fat is termed a panniculitis a group of disorders that may be challenging both for the clinician and the dermatopathologist
panophthalmitis is the inflammation of all coats of the animal eye including intraocular structures it can be caused by infection particularly from pseudomonas species such as pseudomonas aeruginosa clostridium species whipple s disease and also fungi it can also be cause by other stress
pansteatitis or yellow fat disease is a physiological condition in which the body fat becomes inflamed
pantai seri kenangan literally the unforgettable beach is in kuala tutong in tutong district a popular recreation area just five minutes drive from tutong town the beach s appeal is the effect created by a narrow spit of land that separates the mirror smooth tutong river from the ruffled waters of south china sea chalets restaurant huts a playground and food stall are available a little further along the road passes the village of kuala tutong sheltered amidst a forest of coconut palms to reach the old jetty until the tutong bridge was constructed in 1959 a ferry had to be used to travel between the southern district centers of brunei and bandar seri bagawan pantai seri kenangan or seri kenangan beach is the nearest beach to tutong town
pantothenate kinase associated neurodegeneration pkan also known as neurodegeneration with brain iron accumulation 1 nbia 1 and formerly called hallervorden – spatz syndrome use of this eponym is somewhat discouraged due to hallervorden and spatz s affiliation with the nazi regime and the ethically questionable manner in which they acted is a degenerative disease of the brain that can lead to parkinsonism dystonia dementia and ultimately death neurodegeneration in pkan is accompanied by an excess of iron that progressively builds up in the brain
papal regalia and insignia are the official items of attire and decoration proper to the pope in his capacity as the head of the roman catholic church and sovereign of the vatican city state
a paper cut occurs when a piece of paper or other thin sharp material slices a person s skin paper cuts though named from paper can also be caused by other thin stiff materials although a loose paper sheet is usually too soft to cut it can be very thin sometimes as thin as a razor edge being then able to exert high levels of pressure enough to cut the skin paper cuts are most often caused by paper sheets that are strongly fastened together such as brand new paper out of a ream because one single paper sheet might be dislocated from the rest thus all the other sheets are holding this dislocated sheet in position and the very small part held away from the rest can be stiff enough to act as a razor paper cuts can be surprisingly painful as they can stimulate a large number of skin surface nociceptors pain receptors in a very small area of the skin because the shallow cut does not bleed very much the pain receptors are left open to the air ensuring continued pain however the cut can also be very deep in which case a puddle of blood pools around a longer gash this is exacerbated by irritation caused by the fibers in the paper itself which may be coated in chemicals such as bleach additionally most paper cuts occur in the fingers which have a greater concentration of sensory receptors than the rest of the body the random orientation of collagen fibers in skin provides the ability to withstand pinpoint forces however the skin does not have the same strength against shearing forces and is easily cut
papillary eccrine adenoma also known as tubular apocrine adenoma is a cutaneous condition characterized by an uncommon benign sweat gland neoplasm that presents as a dermal nodule located primarily on the extremities of black patients
a papillary fibroelastoma is a primary tumor of the heart that typically involves one of the valves of the heart papillary fibroelastomas while considered generally rare make up about 10 percent of all primary tumors of the heart they are the third most common type of primary tumor of the heart behind cardiac myxomas and cardiac lipomas
papillary renal cell carcinomas are subtypes of renal cell carcinoma rcc
papillary serous cystadenocarcinomas are the most common form of malignant ovarian cancer making up 26 percent of ovarian tumours in women aged over 20 in the united states as with most ovarian tumours due to the lack of early signs of disease these tumours can be large when discovered and have often metastasized often by spreading along the peritoneum
papillary stenosis is a disturbance of the sphincter of oddi a muscular valve that prevents the opening and release of bile or pancreatic fluids into the duodenum in response to food entering the duodenum obstruction of the valve can cause pancreatic pain jaundice bile leaking back into the blood stream attacks of pancreatitis
papillary thyroid cancer or papillary thyroid carcinoma is the most common type of thyroid cancer representing 75 percent to 85 percent of all thyroid cancer cases it occurs more frequently in women and presents in the 20 – 55 year age group it is also the predominant cancer type in children with thyroid cancer and in patients with thyroid cancer who have had previous radiation to the head and neck it is often well differentiated slow growing and localized although it can metastasize
a papillary tumor is a tumor shaped like a small mushroom with its stem attached to the epithelial layer inner lining of an organ
in urologic pathology punlmp short for papillary urothelial neoplasm of low malignant potential is an exophytic outward growing microscopically nipple shaped or papillary pre malignant growth of the lining of the upper genitourinary tract the urothelium which includes the renal pelvis ureters urinary bladder and part of the urethra punlmp is pronounced pun lump like the words pun and lump as their name suggests punlmps are neoplasms i e clonal cellular proliferations that are thought to have a low probability of developing into urothelial cancer i e a malignancy such as bladder cancer they are thought to be relatively rare one study of two hundred papillary urothelial lesions found a prevalence of 0 3 5
papilledema or papilloedema is optic disc swelling that is caused by increased intracranial pressure the swelling is usually bilateral and can occur over a period of hours to weeks unilateral presentation is extremely rare papilledema is mostly seen as a symptom resulting from another pathophysiological process in intracranial hypertension papilledema most commonly occurs bilaterally when papilledema is found on fundoscopy further evaluation is warranted as vision loss can result if the underlying condition is not treated further evaluation with a ct or mri of the brain and or spine is usually performed recentresearch has shown that point of care ultrasound can be used to measure optic nerve sheath diameter for detection of increased intracranial pressure andshows good diagnostic test accuracy compared to ct thus ifthere is a question of papilledema on fundoscopic examination or if the opticdisc cannot be adequately visualized ultrasound can be used to rapidly assessfor increased intracranial pressure and help direct further evaluation andintervention unilateral papilledema can suggest a disease in the eye itself such as an optic nerve glioma
a papilloma plural papillomas or papillomata papillo oma is a benign epithelial tumor growing exophytically outwardly projecting in nipple like and often finger like fronds in this context papilla refers to the projection created by the tumor not a tumor on an already existing papilla such as the nipple when used without context it frequently refers to infections squamous cell papilloma caused by human papillomavirus hpv such as warts human papillomavirus infection is a major cause of cervical cancer although most hpv infections do not cause cancer there are however a number of other conditions that cause papilloma as well as many cases in which there is no known cause
papillomatosis cutis carcinoides also known as gottron s carcinoid papillomatosis and papillomatosis cutis carcinoides of gottron – eisenlohr is a cutaneous condition characterized by verrucous skin lesions and is due to an hpv infection of the skin
papillon – lefèvre syndrome pls also known as palmoplantar keratoderma with periodontitis is an autosomal recessive genetic disorder caused by a deficiency in cathepsin c
papillorenal syndrome also called renal coloboma syndrome or isolated renal hypoplasia is an autosomal dominant genetic disorder marked by underdevelopment hypoplasia of the kidney and colobomas of the optic nerve
pappataci fever also known as phlebotomus fever and somewhat confusingly sandfly fever and three day fever is a vector borne febrile arboviral infection caused by three serotypes of phlebovirus it occurs in subtropical regions of the eastern hemisphere the name pappataci fever comes from the italian word for sandfly it is the union of the word pappa food and taci silent which distinguish these insect from mosquitoes which produce a typical noise while flying
papular eruption of blacks is a cutaneous condition characterized clinically by small pruritic papules and histologically by a mononuclear cell eosinophil perivascular infiltrate
papular mucinosis also known as scleromyxedema generalized lichen myxedematosus and sclerodermoid lichen myxedematosus is a rare skin disease localized and disseminated cases are called papular mucinosis or lichen myxedematosus while generalized confluent papular forms with sclerosis are called scleromyxedema frequently all three forms are regarded as papular mucinosis however some authors restrict it to only mild cases another form acral persistent papular mucinosis is regarded as a separate entity
papular mucinosis of infancy also known as cutaneous mucinosis of infancy is a skin condition caused by fibroblasts producing abnormally large amounts of mucopolysaccharides characterized by skin colored or translucent papules
papular purpuric gloves and socks syndrome is a cutaneous condition characterized by pruritus edema and erythema of the hands and feet occurring primarily in teenagers and young adults an association with parvovirus b 19 has been described
papular xanthoma is a cutaneous condition that is a rare form of non x histiocytosis
papuloerythroderma of ofuji is a rare disorder most commonly found in japan characterized by pruritic papules that spare the skinfolds producing bands of uninvolved cutis creating the so called deck chair sign frequently there is associated blood eosinophilia skin biopsies reveal a dense lymphohistiocytic infiltrate eosinophils in the papillary dermis and increased langerhans cells s 100 positive systemic steroids are the treatment of choice and may result in long term remissions it was characterized in 1984 use of puva in treatment has been described
papulonecrotic tuberculid is usually an asymptomatic chronic skin disorder presenting in successive crops skin lesions symmetrically distributed on the extensor extremities
a papulopustular condition is a condition composed of both papule and pustules examples of papulopustular conditions include papulopustular rosacea papulopustular acne sycosis
a papulosquamous disorder is a condition which presents with both papules and scales or both scaly papules and plaques examples include psoriasis lichen planus and pityriasis rosea
papyrus oxyrhynchus 69 p oxy 69 is a complaint about a robbery written in greek the manuscript was written on papyrus in the form of a sheet it was discovered by grenfell and hunt in 1897 in oxyrhynchus the document was written on 21 november 190 currently it is housed in the haskell oriental institute at the university of chicago 2061 the text was published by grenfell and hunt in 1898 the beginning of the letter is lost it is a petition to an unknown official describing the theft of some barley and asking that an investigation be carried out the author is unknown the measurements of the fragment are 178 by 115 mm the description of the crime scene is quite detailed they broke down a door that led into the public street and had been blocked up with bricks probably using a log of wood as a battering ram they then entered the house and contented themselves with taking what was stored there 10 artabae of barley which they carried off by the same way we guessed that this was removed piecemeal by the said door from the marks of a rope dragged along in that direction and pointed out this fact to the chief of the police of that village and to the other officials 10 artabae are equivalent to approximately 30 – 40 kilograms 66 – 88 lb of barley
papyrus oxyrhynchus 86 p oxy 86 is a complaint of a pilot of a public boat written in greek the manuscript was written on papyrus in the form of a sheet it was discovered in oxyrhynchus the document was written on 28 march 338 currently it is housed in the cambridge university library add ms 4040 in cambridge
paracetamol toxicity is caused by excessive use or overdose of the medication paracetamol acetaminophen most people with paracetamol toxicity have no symptoms in the first 24 hours following overdose others may initially have nonspecific complaints such as vague abdominal pain and nausea with time signs of liver injury may develop these include low blood sugar low blood ph easy bleeding and hepatic encephalopathy some will spontaneously resolve although untreated cases may result in death in the united states and the united kingdom it is the most common cause of acute liver failure paracetamol toxicity is one of the most common causes of poisoning worldwide damage to the liver or hepatotoxicity results not from paracetamol itself but from one of its metabolites n acetyl p benzoquinoneimine napqi napqi decreases the liver s natural antioxidant glutathione and directly damages cells in the liver leading to liver failure risk factors for toxicity include excessive long term alcohol intake fasting anorexia nervosa and the use of certain drugs such as isoniazid treatment is aimed at removing the paracetamol from the body and replacing glutathione activated charcoal can be used to decrease absorption of paracetamol if the patient presents for treatment soon after the overdose the antidote acetylcysteine acts as a precursor for glutathione helping the body regenerate enough to prevent damage to the liver n acetylcysteine can neutralize napqi by itself as well a liver transplant is often required if damage to the liver becomes severe patients treated early have a good prognosis whereas patients that develop major liver abnormalities typically have a poor outcome
paracoccidioidomycosis also known as brazilian blastomycosis south american blastomycosis lutz splendore de almeida disease and paracoccidioidal granuloma is a fungal infection caused by the fungus paracoccidioides brasiliensis sometimes called south american blastomycosis paracoccidioidomycosis is caused by a different fungus than that which causes blastomycosis
the paradox of fiction is a philosophical problem about how people can experience strong emotions from purely fictional things such as art literature and imagination the paradox draws attention to an everyday issue of how people are moved by things which in many ways do not really exist although the ontology of fictional things in general has been discussed in philosophy since plato the paradox was first suggested by colin radford and michael weston in 1975 after radford and weston s original paper they and others have continued the discussion by giving the problem slightly differing formulations and solutions
paradoxical disinhibition is a paradoxical reaction an uncommon but recognized phenomenon characterized by acute excitement and an altered mental state caused by benzodiazepines the mechanism being poorly known but the most accepted theory is that it occurs secondaryto inhibition of the restraining influences of the cortex and frontal lobe due to the gaba mimetic action of benzodiazepines reversal of this action could be attained by an nmda receptor antagonist ketamine
a paradoxical reaction or paradoxical effect is an effect of medical treatment usually a drug opposite to the effect which would normally be expected an example of a paradoxical reaction is pain caused by a pain relief medication
a paraganglioma is a rare neuroendocrine neoplasm that may develop at various body sites including the head neck thorax and abdomen about 97 are benign and cured by surgical removal the remaining 3 are malignant because they are able to produce distant metastases paraganglioma is now the most widely accepted term for these lesions that have been also described as glomus tumor chemodectoma perithelioma fibroangioma and sympathetic nevi
paragonimiasis is a food borne parasitic infection caused by the lung fluke most commonly paragonimus westermani it infects an estimated 22 million people yearly worldwide it is particularly common in east asia more than 30 species of trematodes flukes of the genus paragonimus have been reported among the more than 10 species reported to infect humans and only 8 bringing about infections in humans the most common is p westermani the oriental lung fluke
parakeratosis pustulosa is a cutaneous condition which is exclusively seen in children usually involving one finger most commonly the thumb or index finger with the affected nail showing subungual hyperkeratosis and onycholysis
parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi angle of inclination between those two lines the term is derived from the greek word παράλλαξις parallaxis meaning alteration due to foreshortening nearby objects have a larger parallax than more distant objects when observed from different positions so parallax can be used to determine distances astronomers use the principle of parallax to measure distances to the closer stars here the term parallax is the semi angle of inclination between two sight lines to the star as observed when the earth is on opposite sides of the sun in its orbit these distances form the lowest rung of what is called the cosmic distance ladder the first in a succession of methods by which astronomers determine the distances to celestial objects serving as a basis for other distance measurements in astronomy forming the higher rungs of the ladder parallax also affects optical instruments such as rifle scopes binoculars microscopes and twin lens reflex cameras that view objects from slightly different angles many animals including humans have two eyes with overlapping visual fields that use parallax to gain depth perception this process is known as stereopsis in computer vision the effect is used for computer stereo vision and there is a device called a parallax rangefinder that uses it to find range and in some variations also altitude to a target a simple everyday example of parallax can be seen in the dashboard of motor vehicles that use a needle style speedometer gauge when viewed from directly in front the speed may show exactly 60 but when viewed from the passenger seat the needle may appear to show a slightly different speed due to the angle of viewing
the parallel parking problem is a motion planning problem in control theory and mechanics to determine the path a car must take in order to parallel park into a parking space the front wheels of a car are permitted to turn but the rear wheels must stay aligned when a car is initially adjacent to a parking space to move into the space it would need to move in a direction perpendicular to the allowed path of motion of the rear wheels the admissible motions of the car in its configuration space are an example of a nonholonomic system
parallel slowdown is a phenomenon in parallel computing where parallelization of a parallel algorithm beyond a certain point causes the program to run slower take more time to run to completion parallel slowdown is typically the result of a communications bottleneck as more processor nodes are added each processing node spends progressively more time doing communication than useful processing at some point the communications overhead created by adding another processing node surpasses the increased processing power that node provides and parallel slowdown occurs parallel slowdown occurs when the algorithm requires significant communication particularly of intermediate results some problems known as embarrassingly parallel problems do not require such communication and thus are not affected by slowdown
paralysis is loss of muscle function for one or more muscles paralysis can be accompanied by a loss of feeling sensory loss in the affected area if there is sensory damage as well as motor about 1 in 50 people in the u s have been diagnosed with some form of paralysis transient or permanent the word comes from the greek παράλυσις disabling of the nerves itself from παρά para beside by and λύσις lysis losing and that from λύω luō to lose a paralysis accompanied by involuntary tremors is usually called palsy
paralytic shellfish poisoning psp is one of the four recognized syndromes of shellfish poisoning which share some common features and are primarily associated with bivalve mollusks such as mussels clams oysters and scallops these shellfish are filter feeders and therefore accumulate neurotoxins called saxitoxin produced by microscopic algae such as dinoflagellates diatoms and cyanobacteria dinoflagellates of the genus alexandrium are the most numerous and widespread saxitoxin producers and are responsible for psp blooms in subarctic temperate and tropical locations the majority of toxic blooms have been caused by the morphospecies alexandrium catenella alexandrium tamarense and alexandrium fundyense which together comprise the a tamarense species complex in asia psp is mostly associated with the occurrence of the species pyrodinium bahamense human toxicity and mortality can occur after ingestion of these animals but toxicity is also seen in wild animal populations also some pufferfish including chamaeleon puffer contain saxitoxin making their consumption hazardous
parametritis is an inflammation of the parametrium connective tissue adjacent to the uterus it is considered a form of pelvic inflammatory disease parametritis is inflammation of the ligaments around the uterus parametritis is different from perimetritis which is inflammation of the serosa surrounding the uterus
paramyotonia congenita pc also known as paramyotonia congenita of von eulenburg or eulenburg disease is a rare congenital autosomal dominant neuromuscular disorder characterized by “ paradoxical ” myotonia this type of myotonia has been termed paradoxical because it becomes worse with exercise whereas classical myotonia as seen in myotonia congenita is alleviated by exercise pc is also distinguished as it can be induced by cold temperatures although more typical of the periodic paralytic disorders patients with pc may also have potassium provoked paralysis pc typically presents within the first decade of life and has 100 penetrance patients with this disorder commonly present with myotonia in the face or upper extremities the lower extremities are generally less affected while some other related disorders result in muscle atrophy this is not normally the case with pc this disease can also present as hyperkalemic periodic paralysis and there is debate as to whether the two disorders are actually distinct
paraneoplastic acrokeratosis bazex syndrome also known as acrokeratosis paraneoplastica of bazex and acrokeratosis neoplastica is a cutaneous condition characterized by psoriasiform changes of hands feet ears and nose with involvement of the nails and periungual tissues being characteristic and indistinguishable from psoriatic nails the condition is associated with carcinomas of the upper aerodigestive tract this condition should not be confused with the other unrelated disease called bazex syndrome otherwise referred to as bazex dupre christol syndrome
paraneoplastic cerebellar degeneration pcd is a paraneoplastic syndrome associated with a broad variety of tumors including lung cancer ovarian cancer breast cancer hodgkin ’ s lymphoma and others pcd is a rare condition that occurs in less than 1 of cancer patients as is the case with other paraneoplastic syndromes pcd is believed to be due to an autoimmune reaction targeted against components of the central nervous system mostly to purkinje cells it is thought to be triggered when tumor cells in pcd most commonly ovarian or breast cancer ectopically express proteins normally expressed in the cerebellum this is believed to trigger an anti tumor immune response that may be clinically significant but also an anti neural immune response a broad spectrum of neuronal and glial proteins has been identified as target antigens in pcd neurological symptoms may include among others dysarthria truncal limb and gait ataxia and nystagmus symptoms often develop subacutely and progress rapidly over a period of weeks or months to a plateau period that can last for months to years and which often reflects complete loss of purkinje cells of particular note pcd symptoms precede the diagnosis of the underlying cancer in the majority of cases and often present insidiously and progress rapidly for weeks to months to a severely disabled state followed by a variable plateau period that can last for months to years therefore newly developing cerebellar ataxia should always prompt proper diagnostic measures to exclude pcd tumor removal is still the therapeutic mainstay with very early treatment being essential to prevent irreversible neuronal loss immunosuppressive or immunomodulatory treatments are often ineffective there may be a role for high dose gammaglobulin therapy in the treatment pcd but due to the rare occurrence of this disease controlled trials of this therapy may be difficult
paraneoplastic keratoderma is a cutaneous condition characterized by a hornlike skin texture associated with an internal malignancy
paraneoplastic pemphigus is an autoimmune disorder stemming from an underlying tumor it is hypothesized that antigens associated with the tumor trigger an immune response resulting in blistering of the skin and mucous membranes while patients with malignant and benign tumors are both at risk malignancy is associated with high mortality rates near 90 current treatment focuses on general wound healing and administering corticosteroids which has not demonstrated a high success rate recent research developments aim to treat the underlying tumor in order to alleviate the symptoms of pnp
a paraneoplastic syndrome is a syndrome a set of signs and symptoms that is the consequence of cancer in the body but that unlike mass effect is not due to the local presence of cancer cells in contrast these phenomena are mediated by humoral factors such as hormones or cytokines excreted by tumor cells or by an immune response against the tumor paraneoplastic syndromes are typical among middle aged to older patients and they most commonly present with cancers of the lung breast ovaries or lymphatic system a lymphoma sometimes the symptoms of paraneoplastic syndromes show before the diagnosis of a malignancy which has been hypothesized to relate to the disease pathogenesis in this paradigm tumor cells express tissue restricted antigens e g neuronal proteins triggering an anti tumor immune response which may be partially or rarely completely effective in suppressing tumor growth and symptoms patients then come to clinical attention when this tumor immune response breaks immune tolerance and begins to attack the normal tissue expressing that e g neuronal protein the abbreviation pns is sometimes used for paraneoplastic syndrome although it is used more often to refer to the peripheral nervous system
paranoia is a thought process believed to be heavily influenced by anxiety or fear often to the point of delusion and irrationality paranoid thinking typically includes persecutory or beliefs of conspiracy concerning a perceived threat towards oneself e g everyone is out to get me paranoia is distinct from phobias which also involve irrational fear but usually no blame making false accusations and the general distrust of others also frequently accompany paranoia for example an incident most people would view as an accident or coincidence a paranoid person might believe was intentional
paranoid personality disorder ppd is a mental disorder characterized by paranoia and a pervasive long standing suspiciousness and generalized mistrust of others individuals with this personality disorder may be hypersensitive easily insulted and habitually relate to the world by vigilant scanning of the environment for clues or suggestions that may validate their fears or biases paranoid individuals are eager observers they think they are in danger and look for signs and threats of that danger potentially not appreciating other evidence they tend to be guarded and suspicious and have quite constricted emotional lives their reduced capacity for meaningful emotional involvement and the general pattern of isolated withdrawal often lend a quality of schizoid isolation to their life experience people with ppd may have a tendency to bear grudges suspiciousness tendency to interpret others actions as hostile persistent tendency to self reference or a tenacious sense of personal right patients with this disorder can also have significant comorbidity with other personality disorders
paranoid schizophrenia schizophrenia paranoid type is a sub type of schizophrenia as defined in the diagnostic and statistical manual of mental disorders dsm iv code 295 30 it has been the most common type of schizophrenia schizophrenia is defined as “ a chronic mental disorder in which a person loses touch with reality psychosis schizophrenia is divided into subtypes based on the “ predominant symptomatology at the time of evaluation the clinical picture is dominated by relatively stable and often persecutory delusions that are usually accompanied by hallucinations particularly of the auditory variety hearing voices and perceptual disturbances these symptoms can have a huge effect on functioning and can negatively affect quality of life paranoid schizophrenia is a lifelong disease but with proper treatment a person with the illness can attain a higher quality of life although paranoid schizophrenia is defined by those two symptoms it is also defined by a lack of certain symptoms negative symptoms the following symptoms are not prominent “ disorganized speech disorganized or catatonic behavior or flat or inappropriate affect those symptoms are present in another form of schizophrenia disorganized type schizophrenia the criteria for diagnosing paranoid schizophrenia must be present from at least one to six months this helps to differentiate schizophrenia from other diseases such as bipolar disorder paranoid schizophrenia is defined in the diagnostic and statistical manual of mental disorders 4 th edition but it was dropped from the 5 th edition the american psychiatric association apa chose to eliminate schizophrenia subtypes because they had “ limited diagnostic stability low reliability and poor validity the symptoms and lack of symptoms that were being used to categorize the different subtypes of schizophrenia were not concrete enough to be able to be diagnosed the apa also believed that the subtypes of schizophrenia should be removed because “ they did not appear to help with providing better targeted treatment or predicting treatment response targeted treatment and treatment response vary from patient to patient depending on his or her symptoms it is more beneficial therefore to look at the severity of the symptoms when considering treatment options
at least 50 of the diagnosed cases of schizophrenia experience delusions of reference and delusions of persecution paranoia perceptions and behavior may be part of many mental illnesses such as depression and dementia but they are more prevalent in three mental disorders paranoid schizophrenia delusional disorder persecutory type and paranoid personality disorder paranoia symptoms in paranoid schizophrenia and delusional disorder are characterized by persecutory delusions irrational beliefs that someone else is plotting against them persecutory delusions in paranoid schizophrenia are bizarre clearly implausible not understandable and not derived from ordinary life experiences grandiose and frequently accompanied by auditory hallucinations in contrast persecutory delusions in delusional disorder are not bizarre delusion is about situations that could occur in real life such as being followed being loved having an infection and being deceived by one s spouse but still unjustified persons with paranoia personality disorder tend to be self centered defensive and emotionally distant the paranoia is characterized by continuous suspicions this disorder may impact on social personal and professional areas
paratubal cysts ptcs and paraovarian cysts are epithelium lined fluid filled cysts in the adnexa adjacent to the fallopian tube and ovary the terms are used interchangeably
paraphasia is a type of language output error commonly associated with aphasia and characterized by the production of unintended syllables words or phrases during the effort to speak paraphasic errors are most common in patients with fluent forms of aphasia and comes in three forms phonemic or literal neologistic and verbal paraphasias can affect metrical information segmental information number of syllables or both some paraphasias preserve the meter without segmentation and some do the opposite however most paraphasias affect both partially the term was apparently introduced in 1877 by the german english physician julius althaus in his book on diseases of the nervous system in a sentence reading in some cases there is a perfect chorea or delirium of words which may be called paraphasia
paraphilia also known as sexual perversion and sexual deviation is the experience of intense sexual arousal to atypical objects fetishes situations fantasies behaviors or individuals no consensus has been found for any precise border between unusual sexual interests and paraphilic ones there is debate over which if any of the paraphilias should be listed in diagnostic manuals such as the diagnostic and statistical manual of mental disorders dsm or the international classification of diseases icd the number and taxonomy of paraphilias is under debate one source lists as many as 549 types of paraphilias the dsm 5 has specific listings for eight paraphilic disorders several sub classifications of the paraphilias have been proposed and some argue that a fully dimensional spectrum or complaint oriented approach would better reflect the evidence
paraphimosis ˌpærəfaɪˈmoʊsᵻs or ˌpærəfəˈmoʊsᵻs is an uncommon medical condition in which the foreskin of an uncircumcised penis becomes trapped behind the glans penis and cannot be reduced pulled back to its normal flaccid position covering the glans if this condition persists for several hours or there is any sign of a lack of blood flow paraphimosis should be treated as a medical emergency as it can result in gangrene
paraphrenia is a mental disorder characterized by an organized system of paranoid delusions with or without hallucinations the positive symptoms of schizophrenia without deterioration of intellect or personality its negative symptom this disorder is also distinguished from schizophrenia by a lower hereditary occurrence less premorbid maladjustment and a slower rate of progression onset of symptoms generally occurs later in life near the age of 60 the prevalence of the disorder among the elderly is between 0 1 and 4 paraphrenia is not included in either the dsm 5 or the icd 10 psychotherapists often diagnose patients presenting with paraphrenia as having atypical psychoses delusional disorder psychoses not otherwise specified schizoaffective disorders and persistent persecutory states of older adults recently therapists have also been classifying paraphrenia as very late onset schizophrenia like psychosis
paraplegia is an impairment in motor or sensory function of the lower extremities the word comes from ionic greek παραπληγίη half striking it is usually caused by spinal cord injury or a congenital condition such as spina bifida that affects the neural elements of the spinal canal the area of the spinal canal that is affected in paraplegia is either the thoracic lumbar or sacral regions common victims of this impairment are veterans or members of the armed forces if four limbs are affected by paralysis tetraplegia or quadriplegia is the correct term if only one limb is affected the correct term is monoplegia spastic paraplegia is a form of paraplegia defined by spasticity of the affected muscles rather than flaccid paralysis
a parapneumonic effusion is a type of pleural effusion that arises as a result of a pneumonia lung abscess or bronchiectasis there are three types of parapneumonic effusions uncomplicated effusions complicated effusions and empyema uncomplicated effusions generally respond well to appropriate antibiotic treatment the criteria for a complicated parapneumonic effusion include the presence of pus gram stain – positive or culture positive pleural fluid pleural fluid ph 7 20 and pleural fluid ldh that is greater than three times the upper limit of normal of serum ldh appropriate management includes chest tube drainage tube thoracostomy treatment of empyemas includes antibiotics complete pleural fluid drainage and reexpansion of the lung other treatments include the use of decortication diagnostic techniques available include plain film chest x ray computed tomography ct and ultrasound ultrasound can be useful in differentiating between empyema and other transudative and exudative effusions due in part to relative echogenicity of different organs such as the liver often isoechogenic with empyema
paraproctitis is a purulent inflammation of the cellular tissues surrounding the rectum the most frequent cause is penetration of bacterial flora from the rectum into the surrounding cellular tissues which may occur through an anal fissure the inflammation is sometimes limited to the formation of an abscess and in some cases it spreads for a considerable distance and may be complicated by sepsis the symptoms are acute pain in the rectal region tenderness during defecation elevated body temperature and the appearance of an infiltrate in the anal region or on the buttocks an unlanced abscess may burst and a fistula form the disease becomes chronic after recurrences treatment includes administration of antibiotics and anti inflammatory agents and in the suppurative stage surgical lancing of the abscess
paraproteinemia also known as monoclonal gammopathy is the presence of excessive amounts of paraprotein or single monoclonal gammaglobulin in the blood it is usually due to an underlying immunoproliferative disorder or hematologic neoplasms especially multiple myeloma it is sometimes considered equivalent to plasma cell dyscrasia
parapsoriasis refers to one of a group of skin disorders that are characterized primarily by their resemblance to psoriasis red scaly lesions rather than by their underlying etiology neoplasms can develop from parapsoriasis for example it can develop into cutaneous t cell lymphoma the word parapsoriasis was formed in 1902
a parasitic cone also adventive cone or satellite cone is the cone shaped accumulation of volcanic material not part of the central vent of a volcano it forms from eruptions from fractures on the flank of the volcano these fractures occur because the flank of the volcano is unstable eventually the fractures reach the magma chamber and generate eruptions called flank eruptions which in turn produce a parasitic cone a parasitic cone can also be formed from a dike or sill cutting up to the surface from the central magma chamber in an area different from the central vent an example of parasitic cone is mount scott which is the parasite of mount mazama in crater lake national park oregon usa a peculiar example of multiple parasitic cones is jeju island in south korea jeju features 368 oreum 오름 mount which lie in a roughly lateral line on either side of the island s central dormant shield volcano hallasan
a parasitic disease also known as parasitosis is an infectious disease caused or transmitted by a parasite many parasites do not cause diseases parasitic diseases can affect practically all living organisms including plants and mammals the study of parasitic diseases is called parasitology some parasites like toxoplasma gondii and plasmodium spp can cause disease directly but other organisms can cause disease by the toxins that they produce
parasitic pneumonia is an infection of the lungs by parasites it is a rare cause of pneumonia occurring almost exclusively in immunocompromised persons persons with a weakened or absent immune system this is a respiratory infection that may or may not be serious there are a variety of parasites which can affect the lungs in general these parasites enter the body through the skin or by being swallowed once inside the body these parasites travel to the lungs most often through the blood there a similar combination of cellular destruction and immune response causes disruption of oxygen transportation depending on the type of parasite antibiotics can be prescribed the most common parasites involved ascariasis schistosoma toxoplasma gondii
parasomnias are a category of sleep disorders that involve abnormal movements behaviors emotions perceptions and dreams that occur while falling asleep sleeping between sleep stages or during arousal from sleep most parasomnias are dissociated sleep states which are partial arousals during the transitions between wakefulness and nrem sleep or wakefulness and rem sleep
parastremmatic dwarfism is a rare bone disease that features severe dwarfism thoracic kyphosis a type of scoliosis that affects the upper back a distortion and twisting of the limbs contractures of the large joints malformations of the vertebrae and pelvis and incontinence the disease was first reported in 1970 by leonard langer and associates they used the term parastremmatic from the greek parastremma or distorted limbs to describe it on x rays the disease is distinguished by a flocky or lace like appearance to the bones the disease is congenital which means it is apparent at birth it is caused by a mutation in the trpv 4 gene located on chromosome 12 in humans the disease is inherited in an autosomal dominant manner
a parathyroid adenoma is a benign tumor of the parathyroid gland it generally causes hyperparathyroidism there are very few reports of parathyroid adenomas that were not associated with hyperparathyroidism a human being usually has four parathyroid glands located on the back surface of the thyroid in the neck the parathyroids secrete parathyroid hormone pth which increases the concentration of calcium in the blood by inducing the bones to release calcium into the blood and the kidneys to reabsorb it from the urine into the blood when a parathyroid adenoma causes hyperparathyroidism more parathyroid hormone is secreted causing the calcium concentration of the blood to rise resulting in hypercalcemia
parathyroid carcinoma is a rare malignant neoplasm resulting in parathyroid adenoma to carcinoma progression it forms in tissues of one or more of the parathyroid glands four pea sized glands in the neck that make parathyroid hormone which helps the body store and use calcium it is rare and much less common than parathyroid adenoma it can be difficult to excise
many conditions are associated with disorders of the function of the parathyroid gland parathyroid diseases can be divided into those causing hyperparathyroidism and those causing hypoparathyroidism
a parathyroid neoplasm is a tumor of the parathyroid gland types include parathyroid adenoma parathyroid carcinoma
parathyroiditis is a condition involving inflammation of the parathyroid gland it can be associated with hyperparathyroidism
paratuberculosis or johne s disease ˈjoʊnə is a contagious chronic and sometimes fatal infection that primarily affects the small intestine of ruminants it is caused by the bacterium mycobacterium avium subspecies paratuberculosis infections normally affect ruminants mammals that have four compartments of their stomachs of which the rumen is one but have also been seen in a variety of nonruminant species including rabbits foxes and birds horses dogs and nonhuman primates have been infected experimentally paratuberculosis is found worldwide with some states in australia where it is usually called bovine johne s disease or bjd as the only areas proven to be free of the disease some sources define paratuberculosis by the lack of mycobacterium tuberculosis rather than the presence of any specific infectious agent leaving ambiguous the appropriateness of the term to describe buruli ulcer or lady windermere syndrome
paratyphoid fever also known simply as paratyphoid is a bacterial infection caused by one of the three types of salmonella enterica symptoms usually begin six to thirty days after exposure and are the same as those of typhoid fever often there is a gradual onset of a high fever over several days weakness loss of appetite and headaches also commonly occur some people develop a skin rash with rose colored spots without treatment symptoms may last weeks or months other people may carry the bacteria without being affected however are still able to spread the disease to others both typhoid and paratyphoid are of similar severity paratyphoid fever is a type of enteric fever along with typhoid fever paratyphoid is caused by the bacteria salmonella enterica of the serotype paratyphi a paratyphi b or paratyphi c growing in the intestines and blood they are usually spread by eating or drinking food or water contaminated with the feces of an infected person they may occur when a person who prepares food is infected risk factors include poor sanitation as is found among poor crowded populations occasionally they may be transmitted by sex humans are the only animal infected diagnosis maybe based on symptoms and confirmed by either culturing the bacteria or detecting the bacteria s dna in the blood stool or bone marrow culturing the bacteria can be difficult bone marrow testing is the most accurate symptoms are similar to that of many other infectious diseases typhus is an unrelated disease while there is no vaccine specifically for paratyphoid the typhoid vaccine may provide some benefit prevention includes drinking clean water better sanitation and better handwashing treatment of disease is with antibiotics such as azithromycin resistance to a number of other previously effective antibiotics is common paratyphoid affects about 6 million people a year it is most common in parts of asia and rare in the developed world most cases are due to paratyphi a rather than paratyphi b or c in 2013 paratyphoid fever resulted in about 54 000 deaths down from 63 000 deaths in 1990 the risk of death is between 10 and 15 without treatment while with treatment it may be less than one percent
a paraumbilical or umbilical hernia is a protrusion of the abdominal contents including mesenteric fat or bowel through a weak point of the muscles or ligaments near the navel it can lead to discomfort when fatty tissue gets trapped and a lump can be felt or seen whilst they are not usually life threatening routine surgical treatment is usually advised to prevent enlargement or strangulation or obstruction of the gut women are more frequently affected than men
paravaccinia virus is a viral infection of the parapoxvirus genus of viruses human can contract the virus from contact with livestock infected with bovine papular stomatitis and is common with ranchers milkers and veterinarians infection will present with fever fatigue and lesion on the skin
parcel audit also referred to as small package auditing or shipping auditing is a function often performed by shippers of all sizes the audit process is commonly aimed at finding incorrectly billed charges on an invoice however the majority of companies that search out firms to perform a parcel audit are looking for late package refunds specifically unclaimed late package refunds have shown to be as high as 5 of total shipping spend
pareidolia pærᵻˈdoʊliə parr i doh lee ə is a psychological phenomenon involving a stimulus an image or a sound wherein the mind perceives a familiar pattern of something where none actually exists common examples are perceived images of animals faces or objects in cloud formations the man in the moon the moon rabbit and hidden messages within recorded music played in reverse or at higher or lower than normal speeds
parenting time is the amount of time each parent spends with their children when parents separate disagreements about how to measure it and how to divide it often cause controversy between the parents
paresis is a condition typified by a weakness of voluntary movement or partial loss of voluntary movement or by impaired movement when used without qualifiers it usually refers to the limbs but it can also be used to describe the muscles of the eyes ophthalmoparesis the stomach gastroparesis and also the vocal cords vocal cord paresis neurologists use the term paresis to describe weakness and plegia to describe paralysis in which all voluntary movement is lost the term paresis comes from the ancient greek πάρεσις letting go or paralysis from παρίημι to let go to let fall
paresthesia is a sensation of tingling tickling pricking or burning of a person s skin with no apparent physical cause the manifestation of a paresthesia may be transient or chronic the most familiar kind of paresthesia is the sensation known as pins and needles or of a limb falling asleep a less well known and uncommon but important paresthesia is formication the sensation of bugs crawling underneath the skin
the parikh – doering oxidation is an oxidation reaction that transforms primary and secondary alcohols into aldehydes and ketones respectively the procedure uses dimethyl sulfoxide dmso as the oxidant activated by the sulfur trioxide pyridine complex in the presence of triethylamine base the parikh – doering oxidation the reaction can be run at mild temperatures often between 0 ° c and room temperature without formation of significant amounts of methylthiomethyl ether side product the following example from the total synthesis of – kumausallene by p a evans and coworkers illustrates typical reaction conditions the parikh – doering oxidation
parinaud s oculoglandular syndrome is the combination of granulomatous conjunctivitis in one eye and swollen lymph nodes in front of the ear on the same side most cases are caused by cat scratch disease although it is an unusual feature of this condition occasionally it may be caused by other infections it should not be confused with the neurological syndrome caused by a lesion in the midbrain which is also known as parinaud s syndrome both were named after the same person henri parinaud causes include bartonella henselae francisella tularensis herpes simplex virus type 1 paracoccidioides brasiliensis
parinaud s syndrome also known as dorsal midbrain syndrome vertical gaze palsy and sunset sign is an inability to move the eyes up it is caused by a tumor of the pineal gland which compresses the vertical gaze center at the rostral interstitial nucleus of medial longitudinal fasciculus rimlf the eyes lose the ability to move upward it is a group of abnormalities of eye movement and pupil dysfunction it is caused by lesions of the upper brain stem and is named for henri parinaud 1844 – 1905 considered to be the father of french ophthalmology
paris trousseau syndrome pts is an inherited disorder characterized by mild hemorrhagic tendency associated with 11 q chromosome deletion it manifests as a granular defect within an individual s platelets it is characterized by thrombocytes with defects in α granule components which affects the cell s surfeace area and consequently its abitlity to spread when necessary fli 1 has been suggested as a candidate
the paris effect is a sensation or feeling that heightens the enjoyment of a taste or smell of a food or beverage based on the circumstances of its consumption it is named for paris france
paris syndrome french syndrome de paris japanese パリ症候群 pari shōkōgun is a transient psychological disorder exhibited by some individuals when visiting or vacationing to paris as a result of extreme shock resulting from their finding out that paris is not what they had expected it to be it is characterized by a number of psychiatric symptoms such as acute delusional states hallucinations feelings of persecution perceptions of being a victim of prejudice aggression or hostility from others derealization depersonalization anxiety and also psychosomatic manifestations such as dizziness tachycardia sweating and others such as vomiting similar syndromes include jerusalem syndrome and stendhal syndrome the condition is commonly viewed as a severe form of culture shock it is particularly noted among japanese travelers
this is a pattern of mycorrhizal infection which is coil like in morphology these have direct intracellular growth to new cells the mycoheterotrophic plants use this to their advantage as well as in many tree species such as acer
in computational complexity theory the complexity class ⊕ p pronounced parity p is the class of decision problems solvable by a nondeterministic turing machine in polynomial time where the acceptance condition is that the number of accepting computation paths is odd an example of a ⊕ p problem is does a given graph have an odd number of perfect matchings the class was defined by papadimitriou and zachos in 1983 ⊕ p is a counting class and can be seen as finding the least significant bit of the answer to the corresponding p problem the problem of finding the most significant bit is in pp pp is believed to be a considerably harder class than ⊕ p for example there is a relativized universe see oracle machine where p ⊕ p ≠ np pp exptime as shown by beigel buhrman and fortnow in 1998 while toda s theorem shows that ppp contains ph p ⊕ p is not known to even contain np however the first part of the proof of toda s theorem shows that bpp ⊕ p contains ph lance fortnow has written a concise proof of this theorem ⊕ p contains the graph isomorphism problem and in fact this problem is low for ⊕ p it also trivially contains up since all problems in up have either zero or one accepting paths more generally ⊕ p is low for itself meaning that such a machine gains no power from being able to solve any ⊕ p problem instantly the ⊕ symbol in the name of the class may be a reference to use of the symbol ⊕ in boolean algebra to refer the exclusive disjunction operator this makes sense because if we consider accepts to be 1 and not accepts to be 0 the result of the machine is the exclusive disjunction of the results of each computation path
in boolean algebra a parity function is a boolean function whose value is 1 if and only if the input vector has an odd number of ones the parity function of two inputs is also known as the xor function the parity function is notable for its role in theoretical investigation of circuit complexity of boolean functions the output of the parity function is the parity bit
parity learning is a problem in machine learning an algorithm that solves this problem must guess the function ƒ given some samples x ƒ x and the assurance that ƒ computes the parity of bits at some fixed locations the samples are generated using some distribution over the input the problem is easy to solve using gaussian elimination provided that a sufficient number of samples from a distribution which is not too skewed are provided to the algorithm
parker s notch named after former commissioner of the northwest territories john havelock parker is a protrusion of the northwest territories southwards into nunavut on victoria island in the northwest territories the protrusion is part of the inuvik region and the kitikmeot region in nunavut
parkes weber syndrome pws is an uncommon congenital vascular malformation cvm similar to klippel – trénaunay syndrome but has its own distinct conditions it was first described in 1907 by british dermatologist frederick parkes weber it is only found in about 0 3 of the world population
the parkinson s disease foundation is a leading national presence in the united states in parkinson s disease research education and public advocacy pdf funds scientific research to find the causes of and a cure for parkinson s pdf also offers educational programs and support services for people with parkinson s and their loved ones since its founding in 1957 pdf has funded more than 115 million worth of scientific research in parkinson s disease as well as nearly 50 million in education and advocacy programs pdf has been awarded a four star rating from charity navigator in 10 of 14 assessment years as well as the wise giving alliance of the better business bureau bbb charity seal of approval in recognition of the integrity and efficiency of its programs pdf focuses on meeting the needs of people living with parkinson s by incorporating their perspective into its activities such as the people with parkinson s advisory council which advises pdf on all projects as well as the parkinson s advocates in research program which prepares people with parkinson s disease to play a direct role in shaping the clinical research process in january 2016 the parkinson s disease foundation and the national parkinson foundation signed a letter of intent to merge the two organizations they are expected to sign definitive merger documents after completion of due diligence and to complete the merger as soon as possible thereafter
parkinson s disease pd is a long term disorder of the central nervous system that mainly affects the motor system the symptoms generally come on slowly over time early in the disease the most obvious are shaking rigidity slowness of movement and difficulty with walking thinking and behavioral problems may also occur dementia becomes common in the advanced stages of the disease depression and anxiety are also common occurring in more than a third of people with pd other symptoms include sensory sleep and emotional problems the main motor symptoms are collectively called parkinsonism or a parkinsonian syndrome the cause of parkinson s disease is generally unknown but believed to involve both genetic and environmental factors those with a family member affected are more likely to get the disease themselves there is also an increased risk in people exposed to certain pesticides and among those who have had prior head injuries while there is a reduced risk in tobacco smokers and those who drink coffee or tea the motor symptoms of the disease result from the death of cells in the substantia nigra a region of the midbrain this results in not enough dopamine in these areas the reason for this cell death is poorly understood but involves the build up of proteins into lewy bodies in the neurons diagnosis of typical cases is mainly based on symptoms with tests such as neuroimaging being used to rule out other diseases there is no cure for parkinson s disease initial treatments is typically with the antiparkinson medication levodopa with dopamine agonists being used once levodopa becomes less effective as the disease progresses and neurons continue to be lost these medications become less effective while at the same time they produce a complication marked by involuntary writhing movements diet and some forms of rehabilitation have shown some effectiveness at improving symptoms surgery to place the microelectrodes for deep brain stimulation has been used to reduce motor symptoms in severe cases where drugs are ineffective evidence for treatments for the non movement related symptoms of pd such as sleep disturbances and emotional problems is less strong in 2013 pd was present in 53 million people and resulted in about 103 000 deaths globally parkinson s disease typically occurs in people over the age of 60 of which about one percent are affected males are more often affected than females when it is seen in people before the age of 40 or 50 it is called young onset pd the average life expectancy following diagnosis is between 7 and 14 years the disease is named after the english doctor james parkinson who published the first detailed description in an essay on the shaking palsy in 1817 public awareness campaigns include world parkinson s day on the birthday of james parkinson 11 april and the use of a red tulip as the symbol of the disease people with parkinsonism who have increased the public s awareness of the condition include actor michael j fox olympic cyclist davis phinney and late professional boxer muhammad ali
parkinson plus syndromes also known as disorders of multiple system degeneration is a group of neurodegenerative diseases featuring the classical features of parkinson s disease tremor rigidity akinesia bradykinesia and postural instability with additional features that distinguish them from simple idiopathic parkinson s disease pd some consider alzheimer s disease to be in this group parkinson plus syndromes are either inherited genetically or occur sporadically the atypical parkinsonian or parkinson plus syndromes are often difficult to differentiate from pd and each other they include multiple system atrophy msa progressive supranuclear palsy psp and corticobasal degeneration cbd dementia with lewy bodies dlb may or may not be part of the pd spectrum but it is increasingly recognized as the second most common type of neurodegenerative dementia after alzheimer s disease these disorders are currently lumped into two groups the synucleinopathies and the tauopathies they may coexist with other pathologies additional parkinson plus syndromes include pick s disease and olivopontocerebellar atrophy the latter is characterized by ataxia and dysarthria and may occur either as an inherited disorder or as a variant of multiple system atrophy msa is also characterized by autonomic failure formerly known as shy – drager syndrome clinical features that distinguish parkinson plus syndromes from idiopathic pd include symmetrical onset a lack of or irregular resting tremor and a reduced response to dopaminergic drugs including levodopa additional features include bradykinesia early onset postural instability increased rigidity in axial muscles dysautonomia alien limb syndrome supranuclear gaze palsy apraxia involvement of the cerebellum including the pyramidal cells and in some instances significant cognitive impairment accurate diagnosis of these parkinson plus syndromes is improved when precise diagnostic criteria are used since diagnosis of individual parkinson plus syndromes is difficult the prognosis is often poor proper diagnosis of these neurodegenerative disorders is important as individual treatments vary depending on the condition the nuclear medicine spect procedure using 123 i ibzm is an effective tool in the establishment of the differential diagnosis between patients with pd and parkinson plus syndromes
parkinsonism is a clinical syndrome characterized by tremor bradykinesia rigidity and postural instability parkinsonism shares symptoms found in parkinson s disease from which it is named but parkinsonism is a symptom complex and differs from parkinson disease which is a progressive neurodegenerative illness the underlying causes of parkinsonism are numerous and diagnosis can be complex the neurodegenerative condition parkinson s disease pd is the most common cause of parkinsonism however a wide range of other etiologies may lead to a similar set of symptoms including some toxins a few metabolic diseases and a handful of neurological conditions other than parkinson s about 7 of people with parkinsonism have developed their symptoms following treatment with particular medications side effect of medications mainly neuroleptic antipsychotics especially the phenothiazines such as perphenazine and chlorpromazine thioxanthenes such as flupenthixol and zuclopenthixol and butyrophenones such as haloperidol piperazines such as ziprasidone and rarely antidepressants the incidence of drug induced parkinsonism increases with age drug induced parkinsonism tends to remain at its presenting level not progress like parkinson s disease
paroniria is a medical condition involving an excess of morbid dreams and nightmares paroniria is suspected to have many causes including fear stress depression trauma and sleep deprivation among others
a paronychia ˌpærəˈnɪkiə greek παρωνυχία from para around and onukh nail is a nail disease that is an often tender bacterial or fungal infection of the hand or foot where the nail and skin meet at the side or the base of a finger or toenail the infection can start suddenly acute paronychia or gradually chronic paronychia paronychia is commonly misapplied as a synonym for whitlow or felon
in etymology including onomastics paronymic attraction is the distorting effect exerted on a word by one of its paronyms that is a quasi homonym paronymic attraction is the origin of many names a common phenomenon paronymic attraction is usually expressed through the replacement of a word whose meaning is not understood by a term designating a name common or proper or a common concept
parosmia from the greek para osmi also known as troposmia gk or cacosmia gk is an olfactory dysfunction that is characterized by the inability of the brain to properly identify an odor s natural smell what happens instead is that the natural odor is transcribed into what is most often described as an unpleasant aroma typically a burned rotting fecal or chemical smell there are instances however of pleasant odors this is more specifically called euosmia gk
parotitis is an inflammation of one or both parotid glands the major salivary glands located on either side of the face in humans the parotid gland is the salivary gland most commonly affected by inflammation
paroxysmal attacks or paroxysms from greek παροξυσμός are a sudden recurrence or intensification of symptoms such as a spasm or seizure these short frequent and stereotyped symptoms can be observed in various clinical conditions they are usually associated with multiple sclerosis or pertussis but they may also be observed in other disorders such as encephalitis head trauma stroke asthma trigeminal neuralgia breath holding spells epilepsy malaria tabes dorsalis and behçet s disease paroxysmal nocturnal hemoglobinuria pnh it has also been noted as a symptom of gratification disorder in children the word paroxysm means sudden attack outburst and comes from the greek παροξυσμός paroxusmos irritation exasperation paroxysmal attacks in various disorders have been reported extensively and ephaptic coupling of demyelinated nerves has been presumed as one of the underlying mechanisms of this phenomenon this is supported by the presence of these attacks in multiple sclerosis and tabes dorsalis which both involve demyelination of spinal cord neurons exercise tactile stimuli hot water anxiety and neck flexion may provoke paroxysmal attacks most reported paroxysmal attacks are painful tonic spasms dysarthria and ataxia numbness and hemiparesis they are typically different from other transient symptoms by their brevity lasting no more than 2 minutes frequency from 1 2 times day up to a few hundred times day stereotyped fashion and excellent response to drugs usually carbamazepine withdrawal of symptoms without any residual neurological finding is another key feature in their recognition
paroxysmal cold hemoglobinuria pch also known as donath landsteiner syndrome is a disease of humans that is characterized by the sudden presence of hemoglobin in the urine called hemoglobinuria typically after exposure to cold temperatures
it is noteworthy that unmasking persistent sodium current in presence of calcium channel blocker has been well established it is likely that calcium channel blocker will block voltage and ligand gated calcium channel thereby affecting calcium activated potassium channel in invertebrate model system the initiation of pds without blocking any channel are much more prevalent in mammalian neurons for example thalamocortical neuron ca 3 pyramidal neuron and some hypothalamic neurons the possibility of spontaneous bursting in these neurons are implicated in regulating hormonal secretion the significance of pds may increase the signal to noise ratio plays vital role in information processing synaptic plasticity and among others in contrast the pdss could be generated by electrical or chemical stimulation to single neurons depending on influx of ions pds can be theoretically categorized into two type ca 2 dependent pds requires the entry of ca 2 while na dependent pds is presumed to be non synaptic the pds found in invertebrates like helix and higher vertebrates are assumed to predominantly generated by activation of ampa receptor subsequently leading to activation of nmda receptor the evidence shows that there is probable increase in intracellular calcium ions which sustained calcium dependent pds as usual this ca ions will activate calcium dependent potassium channel and pds will terminate this is the case of that provides clue for synaptic transmission alternatively the pds can still occur and less frequently studied in blocking calcium channel with heavy metals such as ni 2 the further evidence for na dependent pds are highlighted in leech with the possibility to study pds in detail it is likely that such type of pds sustained in absence of calcium the case represents the non synaptic nature of pds finally the na k pump and calcium activated potassium channel might play a role in terminating pds paradoxically there might arise the argument whether intracellular calcium could able to repolarize the single neuron while blocking these calcium entry from extracellular milleu however the other opportunity such as na ca 2 exchange as well as small contribution from intracellular stores need to be explored if several million neurons discharge at once it shows up on a scalp eeg as a focal interictal epileptiform spike paroxysmal depolarizing shifts can lead to an epileptic seizure if there is an underlying predisposition and recording the spike can be an important aid in distinguishing seizure types
paroxysmal exercise induced dystonia or ped is a rare neurological disorder characterized by sudden transient involuntary movements often including repetitive twisting motions and painful posturing triggered by exercise or other physical exertion ped is in the class of paroxysmal dyskinesia which are a group of rare movement disorders characterized by attacks of hyperkinesia with intact consciousness the term paroxysmal indicates that the episodes are sudden and short lived and usually unpredicted and return to normal is rapid the number of reported cases of people with ped is very small leading to difficulty in studying and classifying this disease and most studies are limited to a very small number of test subjects
paroxysmal extreme pain disorder pepd originally named familial rectal pain syndrome is a rare disorder whose most notable features are pain in the mandibular ocular and rectal areas as well as flushing pepd often first manifests at the beginning of life perhaps even in utero with symptoms persisting throughout life pepd symptoms are reminiscent of primary erythromelalgia as both result in flushing and episodic pain though pain is typically present in the extremities for primary erythromelalgia both of these disorders have recently been shown to be allelic both caused by mutations in the voltage gated sodium channel nav 1 7 encoded by the gene scn 9 a a different mutation in scn 9 a causes congenital insensitivity to pain
paroxysmal hand hematoma also known as achenbach syndrome is a skin condition characterized by spontaneous focal hemorrhage into the palm or the volar surface of a finger which results in transitory localized pain followed by rapid swelling and localized blueish discoloration
paroxysmal hypertension is episodic and volatile high blood pressure which may be due to stress of any sort or from a pheochromocytoma a type of tumor involving the adrenal medulla patients with paroxysmal hypertension who test negative for pheochromocytoma are said to be suffering from a clinical entity called pseudopheochromocytoma this disorder is due to episodic dopamine discharge and has been observed predominantly in hypertensive women that had episodes that shared similar characteristics of pheochromocytoma but testing proved negative and had ruled out the tumor in patients with pseudopheochromocytoma dopamine was found to be significantly increased post paroxysm the paroxysm is said to be similar to the hypertensive episodes described by page these episodes commonly occur after diencephalic stimulation therefore pseudopheochromocytoma shares many characteristics of page s syndrome pseudopheochromocytoma colloquially known as page s syndrome is caused predominantly by episodic dopamine discharge stressors including pain or anxiety or possibly repressed emotions caused by prior emotional trauma and commonly a repressive way of coping emotionally therefore treatment of pseudopheochromocytoma is aimed at psychological support and intervention with antidepressants but also treatment with alpha and then beta blockers in resistant cases
paroxysmal kinesigenic choreathetosis pkc also called paroxysmal kinesigenic dyskinesia pkd is a hyperkinetic movement disorder characterized by attacks of involuntary movements which are triggered by sudden voluntary movements the number of attacks can increase during puberty and decrease in a person s 20 s to 30 s involuntary movements can take many forms such as ballism chorea or dystonia and usually only affect one side of the body or one limb in particular this rare disorder only affects about 1 in 150 000 people with pkd accounting for 86 8 of all the types of paroxysmal dyskinesias and occurs more often in males than females there are two types of pkd primary and secondary primary pkd can be further broken down into familial and sporadic familial pkd which means the individual has a family history of the disorder is more common but sporadic cases are also seen secondary pkd can be caused by many other medical conditions such as multiple sclerosis ms stroke pseudohypoparathyroidism hypocalcemia hypoglycemia hyperglycemia central nervous system trauma or peripheral nervous system trauma pkd has also been linked with infantile convulsions and choreoathetosis icca syndrome in which patients have afebrile seizures during infancy benign familial infantile epilepsy and then develop paroxysmal choreoathetosis later in life this phenomenon is actually quite common with about 42 of individuals with pkd reporting a history of afebrile seizures as a child
paroxysmal nocturnal hemoglobinuria pnh is a rare acquired life threatening disease of the blood characterized by destruction of red blood cells by the complement system a part of the body s intrinsic immune system this destructive process is a result of a defect in the formation of surface proteins on the red blood cell which normally function to inhibit such immune reactions since the complement cascade attacks the red blood cells throughout the circulatory system the hemolysis is considered an intravascular hemolytic anemia other key features of the disease notably the high incidence of thrombosis are not totally understood pnh is the only hemolytic anemia caused by an acquired rather than inherited intrinsic defect in the cell membrane deficiency of glycophosphatidylinositol leading to absence of protective proteins on the membrane it may develop on its own primary pnh or in the context of other bone marrow disorders such as aplastic anemia secondary pnh only a minority 26 have the telltale red urine in the morning that originally gave the condition its name allogeneic bone marrow transplantation is the only curative therapy but has significant rates of both mortality and ongoing morbidity the monoclonal antibody eculizumab is effective at reducing the need for blood transfusions and improving quality of life it however does not appear to change the risk of death or blood clots and has an extremely high price with a single year of treatment costing at least 440 000
paroxysmal nonkinesigenic dyskinesia pnkd is an episodic movement disorder first described by mount and reback in 1940 under the name familial paroxysmal choreoathetosis it is a rare hereditary disease that affects various muscular and nervous systems in the body passing to roughly fifty percent of the offspring
paroxysmal supraventricular tachycardia psvt is a type of supraventricular tachycardia often people have no symptoms otherwise symptoms may include palpitations feeling lightheaded sweating shortness of breath and chest pain episodes start and end suddenly the cause is not known risk factors include alcohol caffeine nicotine psychological stress and wolff parkinson white syndrome which often is inherited from a person s parents the underlying mechanism typically involves an accessory pathway that results in re entry diagnosis is typically by an electrocardiogram ecg which shows narrow qrs complexes and a fast heart rhythm typically between 150 and 240 beats per minute vagal maneuvers such as the valsalva maneuver are often used as the initial treatment if not effective and the person has a normal blood pressure the medication adenosine may be tried if adenosine is not effective a calcium channel blockers or beta blocker maybe used otherwise synchronized cardioversion is the treatment future episodes can be prevented by catheter ablation about 2 3 per 1000 people have paroxysmal supraventricular tachycardia problems typically begin in those 12 to 45 years old women are more often affected than men outcomes in those who otherwise have a normal heart are generally good an ultrasound of the heart may be done to rule out underlying heart problems
paroxysmal sympathetic hyperactivity psh is a syndrome that causes episodes of increased activity of the sympathetic nervous system hyperactivity of the sympathetic nervous system can manifest as increased heart rate increased respiration increased blood pressure diaphoresis and hyperthermia previously this syndrome has been identified as general dysautonomia but now is considered a specific form of it it has also been referred to as paroxysmal sympathetic instability with dystonia or paid and sympathetic storm recently however studies have adopted the name paroxysmal sympathetic hyperactivity to ensure specificity psh is observed more in younger patients than older ones it is also seen more commonly in men than women there is no known reason why this is the case although it is suspected pathophysiological links may exist in patients surviving traumatic brain injury the occurrence of these episodes is one in every three psh can also be associated with severe anoxia subarachnoid and intracerebral hemorrhage and hydrocephalus
paroxysmal tonic upgaze ptu of childhood is a rare and distinctive neuro ophthalmological syndrome characterized by episodes of sustained upward deviation of the eyes symptoms normally appear in babies under one year of age and are characterized by an upward stare or gaze with the eyes rolled back while the chin is typically held low babies suffering from ptu may exhibit normal or slightly jerky side to side eye movement nausea irritability frequent sleep developmental and language delays vertigo and loss of muscle tone the condition is generally regarded as having a benign outcome in the sense that it improves rather than worsens over time the average age of recovery is at about 2 5 years ptu was first described in 1988 as of 2002 approximately fifty cases had been diagnosed because the condition is so rare the majority of physicians have never seen it and thus may not recognize it videotaping a child both in and out of the upgaze state can be vital for reaching a diagnosis
in mathematics the parry – daniels map is a function studied in the context of dynamical systems typical questions concern the existence of an invariant or ergodic measure for the map it is named after the english mathematician bill parry and the british statistician henry daniels who independently studied the map in papers published in 1962
parry – romberg syndrome also known as progressive hemifacial atrophy is a rare disease characterized by progressive shrinkage and degeneration of the tissues beneath the skin usually on only one side of the face hemifacial atrophy but occasionally extending to other parts of the body an autoimmune mechanism is suspected and the syndrome may be a variant of localized scleroderma but the precise etiology and pathogenesis of this acquired disorder remains unknown it has been reported in the literature as a possible consequence of sympathectomy the syndrome has a higher prevalence in females and typically appears between 5 – 15 years of age in addition to the connective tissue disease the condition is sometimes accompanied by neurological ocular and oral symptoms the range and severity of associated symptoms and findings are highly variable
in functional programming a parser combinator is a higher order function that accepts several parsers as input and returns a new parser as its output in this context a parser is a function accepting strings as input and returning some structure as output typically a parse tree or a set of indices representing locations in the string where parsing stopped successfully parser combinators enable a recursive descent parsing strategy that facilitates modular piecewise construction and testing this parsing technique is called combinatory parsing parsers built using combinators are straightforward to construct readable modular well structured and easily maintainable they have been used extensively in the prototyping of compilers and processors for domain specific languages such as natural language interfaces to databases where complex and varied semantic actions are closely integrated with syntactic processing in 1989 richard frost and john launchbury demonstrated use of parser combinators to construct natural language interpreters graham hutton also used higher order functions for basic parsing in 1992 s d swierstra also exhibited the practical aspects of parser combinators in 2001 in 2008 frost hafiz and callaghan described a set of parser combinators in haskell that solve the long standing problem of accommodating left recursion and work as a complete top down parsing tool in polynomial time and space
parsonage – turner syndrome is also known as acute brachial neuropathy and acute brachial radiculitis other names used are parsonage – aldren – turner syndrome neuralgic amyotrophy brachial neuritis brachial plexus neuropathy or brachial plexitis the syndrome is idiopathic although many specific risk factors have been identified such as post operatively post infectious post traumatic or post vaccination the aetiology is still unknown the condition manifests as a rare set of symptoms most likely resulting from autoimmune inflammation of unknown etiology of the brachial plexus the brachial plexus is a complex network of nerves through which impulses reach the arms shoulders and chest parsonage – turner syndrome has an incidence of 1 64 cases in 100 000 people
part time job terrorism バイトテロ baito tero is a japanese social phenomenon part time employees perform pranks and stunts such as climbing into ice cream freezers or holding their body horizontally suspended more colloquially termed planking on the counter tops at fast food restaurants usually with the sole purpose of gaining recognition from their peers through the photos and or videos they later display on social media sites this social phenomenon commonly involves people with high job dissatisfaction — a factor which is commonly cited by the media alongside low pay and arduously long working hours although pranks such as the aforementioned would not be seen as shocking by many other cultures they are considered disgraceful in japanese culture japanese culture is often associated with long hours some individuals working as many as 60 hours a week such working hours are associated with mental and physiological health complications with japanese newspapers citing rare cases of spontaneous death informally known as karōshi to complicate matters further japanese offices are often noisy smoke filled due to lack of smoking laws environments and this may have further adverse effects on the health and well being of employees part time job terrorism might in this context be a form of escapism disenchanted employees gaining support from their peers outside of work to compensate for the praise or reward their working life lacks the social phenomenon emerged around the summer of 2013 when internet based japanese news agencies such as yukan news recorded such an incident with more traditional news agencies later following suit in japanese the social phenomenon is termed baito tero the name stems from the japanese word baito which means part time job and is a loan word originating from the german arbeit meaning work japanese employers are nonplussed by such shenanigans and penalties and punishment can range from administrative tongue lashings to termination of employment employees can also in some circumstances be held financially accountable for loss of business due to the negative publicity
partial androgen insensitivity syndrome pais is a condition that results in the partial inability of the cell to respond to androgens the partial unresponsiveness of the cell to the presence of androgenic hormones impairs the masculinization of male genitalia in the developing fetus as well as the development of male secondary sexual characteristics at puberty but does not significantly impair female genital or sexual development as such the insensitivity to androgens is only clinically significant when it occurs in genetic males i e individuals with a y chromosome or more specifically an sry gene pais is one of three types of androgen insensitivity syndrome which is divided into three categories that are differentiated by the degree of genital masculinization complete androgen insensitivity syndrome cais is indicated when the external genitalia is that of a normal female mild androgen insensitivity syndrome mais is indicated when the external genitalia is that of a normal male and partial androgen insensitivity syndrome pais is indicated when the external genitalia is partially but not fully masculinized androgen insensitivity syndrome is the largest single entity that leads to 46 xy undermasculinization
partial anterior circulation infarct paci is a type of cerebral infarction affecting part of the anterior circulation supplying one side of the brain partial anterior circulation stroke syndrome pacs refers to the symptoms of a patient who clinically appears to have suffered from a partial anterior circulation infarct but who has not yet had any diagnostic imaging e g ct scan to confirm the diagnosis it is diagnosed by any one of the following 2 out of 3 features of higher dysfunction dysphasia visuospatial disturbances homonymous hemianopia motor and sensory defects 2 3 of face arm leg higher dysfunction alone partial motor or sensory defect if all of the above symptoms are present a total anterior circulation infarct is more likely for more information see stroke
partial equilibrium is a condition of economic equilibrium which takes into consideration only a part of the market ceteris paribus to attain equilibrium as defined by george stigler a partial equilibrium is one which is based on only a restricted range of data a standard example is price of a single product the prices of all other products being held fixed during the analysis the supply and demand model is a partial equilibrium model where the clearance on the market of some specific goods is obtained independently from prices and quantities in other markets in other words the prices of all substitutes and complements as well as income levels of consumers are taken as given this makes analysis much simpler than in a general equilibrium model which includes an entire economy here the dynamic process is that prices adjust until supply equals demand it is a powerfully simple technique that allows one to study equilibrium efficiency and comparative statics the stringency of the simplifying assumptions inherent in this approach make the model considerably more tractable but may produce results which while seemingly precise do not effectively model real world economic phenomena partial equilibrium analysis examines the effects of policy action in creating equilibrium only in that particular sector or market which is directly affected ignoring its effect in any other market or industry assuming that they being small will have little impact if any hence this analysis is considered to be useful in constricted markets léon walras first formalized the idea of a one period economic equilibrium of the general economic system but it was french economist antoine augustin cournot and english political economist alfred marshall who developed tractable models to analyze an economic system
partial oxidation pox is a type of chemical reaction it occurs when a substoichiometric fuel air mixture is partially combusted in a reformer creating a hydrogen rich syngas which can then be put to further use for example in a fuel cell a distinction is made between thermal partial oxidation tpox and catalytic partial oxidation cpox
in combinatorial mathematics a partial permutation or sequence without repetition on a finite set sis a bijection between two specified subsets of s that is it is defined by two subsets u and v of equal size and a one to one mapping from u to v equivalently it is a partial function on s that can be extended to a permutation
focal seizures also called partial seizures and localized seizures are seizures which affect initially only one hemisphere of the brain the brain is divided into two hemispheres each consisting of four lobes – the frontal temporal parietal and occipital lobes in partial seizures the seizure is generated in and affects just one part of the brain – the whole hemisphere or part of a lobe symptoms will vary according to where the seizure occurs in the frontal lobe symptoms may include a wave like sensation in the head in the temporal lobe a feeling of déjà vu in the parietal lobe a numbness or tingling and in the occipital lobe visual disturbance or hallucination partial seizures are split into two main categories simple partial seizures and complex partial seizures a new classification system for partial seizures has been described in the 18 th edition of harrison s principles of internal medicine released july 2011 the new classification splits partial seizures into partial seizures with dyscognitive features and partial seizures without dyscognitive features in simple partial seizures a small part of one of the lobes may be affected and the person remains conscious this will often be a precursor to a larger seizure such as a complex partial seizure when this is the case the simple partial seizure is usually called an aura a complex partial seizure affects a larger part of the hemisphere than a simple partial seizure and the person may lose consciousness if a partial seizure spreads from one hemisphere to the other side of the brain this will give rise to a secondarily generalised seizure the person will become unconscious and may well have a tonic clonic seizure partial seizures are common in temporal lobe epilepsy
partial unilateral lentiginosis also known as segmental lentiginosis is a cutaneous condition characterized by lentigines located on only one half of the body
participation bias is a phenomenon in which the results of elections studies polls etc become non representative because the participants disproportionately possess certain traits which affect the outcome for instance a study found that those who refused to answer a survey on aids tended to be older attend church more often are less likely to believe in the confidentiality of surveys and have lower sexual self disclosure
participative decision making pdm is the extent to which employers allow or encourage employees to share or participate in organizational decision making probst 2005 according to the format of pdm could be formal or informal in addition the degree of participation could range from zero to 100 in different participative management pm stages brenda 2001 pdm is one of many ways in which an organization can make decisions the leader must think of the best possible style that will allow the organization to achieve the best results according to psychologist abraham maslow workers need to feel a sense of belonging to an organization see maslow s hierarchy of needs
in quantum mechanics the particle in a one dimensional lattice is a problem that occurs in the model of a periodic crystal lattice the potential is caused by ions in the periodic structure of the crystal creating an electromagnetic field so electrons are subject to a regular potential inside the lattice this is an extension of the free electron model that assumes zero potential inside the lattice
the gamma function is an important special function in mathematics its particular values can be expressed in closed form for integer and half integer arguments but no simple expressions are known for the values at rational points in general other fractional arguments can be approximated through efficient infinite products infinite series and recurrence relations
particulate inheritance is a pattern of inheritance discovered by mendelian genetics theorists such as william bateson ronald fisher or gregor mendel himself showing that phenotypic traits can be passed from generation to generation through discrete particles known as genes which can keep their ability to be expressed while not always appearing in a descending generation
party discipline is the ability of a parliamentary group of a political party to get its members to support the policies of their party leadership in liberal democracies it usually refers to the control that party leaders have over their caucus members in the legislature party discipline is important for all systems of government that allow parties to hold political power because it determines the degree to which the governmental infrastructure will be affected by legitimate political processes the term has a somewhat different meaning in marxism – leninist political systems such as the people s republic of china in this case it refers to administrative sanctions such as fines or expulsion that the communist party can impose on its members for actions such as corruption or disagreeing with the party breaking party discipline in parliamentary votes can result in a number of penalties for the member who dissents these penalties include not being promoted to a cabinet position and losing other perks of elected office like travel their disagreement with their party caucus may be so strong that they leave the party to join another parliamentary caucus or become an independent this is known as crossing the floor in many political systems a member of each party is officially designated or elected as a whip whose role it is to enforce party discipline
the pascal photocoagulator is an integrated semi automatic pattern scan laser photocoagulation system designed to treat ocular diseases using a single shot or predetermined pattern array the device is for ophthalmologists particularly those that focus in vitreo retinal surgery a type of eye surgery it was developed by optimedica an ophthalmic medical device company located in silicon valley sunnyvale ca
pashayan syndrome also known as pashayan – prozansky syndrome and blepharo naso facial syndrome is a rare syndrome facial abnormalities characterise this syndrome as well as malformation of extremities specific characteristics would be a bulky flattened nose where the face has a mask like appearance and the ears are also malformed a subset of pashayan syndrome has also been described known as cerebrofacioarticular syndrome van maldergem syndrome or van maldergem – wetzburger – verloes syndrome similar symptoms are noted in these cases as in pashayan syndrome
the passerini reaction is a chemical reaction involving an isocyanide an aldehyde or ketone and a carboxylic acid to form a α acyloxy amide the passerini reaction this organic reaction was discovered by mario passerini in 1921 in florence italy it is the first isocyanide based multi component reaction developed and currently plays a central role in combinatorial chemistry recently denmark et al have developed an enantioselective catalyst for asymmetric passerini reactions
passing is the ability of a person to be regarded as a member of an identity group or category different from their own which may include racial identity ethnicity caste social class sexuality gender religion age and or disability status passing may result in privileges rewards or an increase in social acceptance or be used to cope with difference anxiety thus passing may serve as a form of self preservation or self protection in instances where expressing one s true or authentic identity may be dangerous passing may require acceptance into a community and can also lead to temporary or permanent leave from another community to which an individual previously belonged thus passing can result in separation from ones original self family friends or previous living experiences while successful passing may contribute to economic security safety and avoidance of stigma it may take an emotional toll as a result of denial of the authentic self and may lead to depression or self loathing etymologically the term is simply the nominalisation of the verb pass in its phrasal use with for or as as in a counterfeit passing for the genuine article or an impostor passing as another person it has been in popular use since at least the late 1920 s
passive aggressive behavior is the indirect expression of hostility such as through procrastination stubbornness sullen behavior or deliberate or repeated failure to accomplish requested tasks for which one is often explicitly responsible for research purposes the diagnostic and statistical manual of mental disorders dsm revision iv describes passive aggressive personality disorder as a pervasive pattern of negativistic attitudes and passive resistance to demands for adequate performance in social and occupational situations passive aggressive behaviour often utilises malicious compliance that is veiling one s intent to not do something in performing the specific task in such a way that an unwanted result is caused
the pasteur effect is an inhibiting effect of oxygen on the fermentation process
pasteurellosis is an infection with a species of the bacterial genus pasteurella which is found in humans and other animals pasteurella multocida subspecies p m septica and p m multocida is carried in the mouth and respiratory tract of various animals including pigs it is a small gram negative bacillus with bipolar staining by wayson stain in animals it can originate fulminant septicaemia chicken cholera but is also a common commensal until taxonomic revision in 1999 mannheimia spp were classified as pasteurella spp and infections by organisms now called mannheimia spp as well as by organisms now called pasteurella spp were designated as pasteurellosis the term pasteurellosis is often still applied to mannheimiosis although such usage has declined
the pastry war spanish guerra de los pasteles french guerre des pâtisseries also known as the first french intervention in mexico or the first franco mexican war 1838 – 1839 began in november 1838 with the naval blockade of some mexican ports and the capture of the fortress of san juan de ulúa in veracruz by french forces sent by king louis philippe it ended several months later in march 1839 with a british brokered peace the intervention followed many claims by french nationals of losses due to unrest in mexico city as well as the failure of mexico to pay a large debt to france this incident was the first and lesser of mexico s two 19 th century wars with france being followed by the french invasion of 1861 – 67 resulting in the installation of emperor maximilian i of mexico
patrick pat rummerfield born september 7 1953 is the first spinal cord injury sci quadriplegic in history to recover full physical mobility he has numerous athletic accomplishments and works as a motivational speaker
the patagonia picnic table effect also known as the patagonia rest area effect or patagonia rest stop effect is a phenomenon associated with birding in which an influx of birdwatchers following the discovery of a rare bird at a location results in the discovery of further rare birds at that location and so on with the end result being that the locality becomes well known for rare birds even though in itself it may be little or no better than other similar localities the name arises from the patagonia rest stop in arizona where the phenomenon was first noted
patau syndrome is a syndrome caused by a chromosomal abnormality in which some or all of the cells of the body contain extra genetic material from chromosome 13 the extra genetic material disrupts normal development causing multiple and complex organ defects this can occur either because each cell contains a full extra copy of chromosome 13 a disorder known as trisomy 13 or trisomy d or because each cell contains an extra partial copy of the chromosome i e robertsonian translocation or because of mosaic patau syndrome full trisomy 13 is caused by nondisjunction of chromosomes during meiosis the mosaic form is caused by nondisjunction during mitosis like all nondisjunction conditions such as down syndrome and edwards syndrome the risk of this syndrome in the offspring increases with maternal age at pregnancy with about 31 years being the average patau syndrome affects somewhere between 1 in 10 000 and 1 in 21 700 live births
patch type granuloma annulare also known as macular granuloma annulare is a skin condition of unknown cause more commonly affecting women between 30 and 70 years of age characterized by flat or slightly palpable erythematous or red brown skin lesions
a patella fracture is a fracture of the kneecap which is one of the most common knee injuries it is usually the result of a hard blow to the front of the knee treatment options for patella fracture include nonsurgical and surgical options depending on the type of fracture an undisplaced fracture of patella takes around 4 – 6 weeks of immobilization in a cylinder cast to heal while a displaced fracture requires surgical treatment followed by quadriceps strengthening exercises for complete rehabilitation
patellar dislocation is an injury of the knee typically caused by a direct blow or a sudden twist of the leg it occurs when the patella kneecap slips out of its normal position in the patellofemoral groove and generally causes intense pain with swelling of the knee open or arthroscopic surgery may be used to repair damage but are typically avoided since rates of re injury knee function and patients opinions do not differ much from conservative treatment the patella generally dislocates laterally and can be accompanied by acute pain and disability immediate reduction can be accomplished by hyperextension of the knee and by providing a medialward pressure to move the patella back into the patellofemoral groove hyperextension of the knee on its own could possibly move the patella into place because this motion locks the knee in place when the knee is locked the ligaments are twisted and taut allowing the muscles involved to relax and the patella to slide back into place if that does not work a medical professional must manually perform an orthopedic reduction swelling and impaired mobility follow patellar dislocation and a rehabilitation program of six to sixteen weeks is recommended whether or not the patient undergoes surgery young athletes suffer patellar dislocations more commonly than any other group and the average age of occurrences is 16 – 20 years sports commonly associated with the injury involve sudden twisting motions of the knee and or impact such as soccer gymnastics and ice hockey it can also occur when a person trips over an object or slips on a slick surface especially if that person has predisposing factors
patellar subluxation syndrome also known as patellar instability or unstable kneecap is an injury that is concerned with the kneecap patellar subluxation is more common than patellar dislocation and is just as disabling in this condition the patella repetitively subluxates and places strain on the medial restraints and excessive stress tension on the patellofemoral joint patellar subluxation can be caused by osseous abnormalities such as incorrect articulation of the femoral groove with the patella trochlear dysplasia or patella alta which is a distance of greater than 20 mm between the tibial tubercle and the trochlear groove it can also result from soft tissue abnormalities such as a torn medial patellofemoral ligament or a weakened vastus medialis obliquus symptoms are regulated by the amount of activity such pain is commonly caused by running and jumping sports and activities that place large forces on the patellofemoral joint symptoms usually include knee buckles and can no longer support your weight kneecap slips off to the side knee catches during movement pain in the front of the knee that increases with activity pain when sitting stiffness creaking or cracking sounds during movement swelling patellar subluxation was once thought to occur mainly in women due to the frequency of genu valgum and lax ligaments however now the frequency of this condition in any athletic person man or woman is apparent
patellar tendinitis patellar tendinopathy also known as jumper s knee is a relatively common cause of pain in the inferior patellar region in athletes it is common with frequent jumping and studies have shown it may be associated with stiff ankle movement and ankle sprains
patellar tendon rupture is a rupture of the tendon that connects the patella to the tibia the superior portion of the patellar tendon attaches on the posterior portion of the patella and the posterior portion of the patella tendon attaches to the tibial tubercle on the front of the tibia above the patella are the quadriceps muscle large muscles on the front of the thigh the quadriceps tendon attaches to the top of the patella this structure allows the knee to flex and extend allowing use of basic functions such as walking and running there are three possible forms of patellar tendon rupture the first form of rupture is a complete tear in a complete tear the tendon separates completely from the top of the tibia which results in the inability to straighten one s leg when the tendon tears it can break a piece of the bone off of the kneecap the second form of rupturing the patellar tendon is a partial tear a partial tear is when some of the fibers of the patellar tendon are torn but the majority of the tendon is still attached to the soft tissue located at the posterior end of the patella bone the third form of rupture is caused by patellar tendinitis jumper s knee patellar tendinitis causes the tendon to be torn in the middle due to the tissue damage it has been acquiring from over use patellar tendonitis is inflammation of the tendon which results in the weakening of the tendon tendonitis is caused by excessive jumping or running without sufficient rest the tell tale sign of a ruptured patella tendon is the movement of the patella further up the quadriceps when rupture occurs the patella loses support from the tibia and moves toward the hip when the quadriceps muscle contracts hindering the leg s ability to extend this means that those affected cannot stand as their knee buckles and gives way when they attempt to do so
patellofemoral pain syndrome pfps is a syndrome characterized by knee pain ranging from severe to mild discomfort seemingly originating from the contact of the posterior surface of the patella back of the kneecap with the femur thigh bone the population most at risk from pfps are runners cyclists basketball players and other sports participants onset can be gradual or the result of a single incident and is often caused by a change in training regime that includes dramatic increases in training time distance or intensity it can be compounded by worn or the wrong type of footwear symptoms include discomfort while sitting with bent knees or descending stairs and generalised knee pain treatment involves resting and physical therapy that includes stretching and strengthening exercises for the legs
patent ductus arteriosus pda is a condition wherein the ductus arteriosus fails to close after birth early symptoms are uncommon but in the first year of life include increased work of breathing and poor weight gain an uncorrected pda may lead to congestive heart failure with increasing age the ductus arteriosus is a fetal blood vessel that closes soon after birth in a pda the vessel does not close and remains patent open resulting in irregular transmission of blood between the aorta and the pulmonary artery pda is common in newborns with persistent respiratory problems such as hypoxia and has a high occurrence in premature newborns premature newborns are more likely to be hypoxic and have pda due to underdevelopment of the heart and lungs a pda allows a portion of the oxygenated blood from the left heart to flow back to the lungs by flowing from the aorta which has higher pressure to the pulmonary artery if this shunt is substantial the neonate becomes short of breath the additional fluid returning to the lungs increases lung pressure which in turn increases the energy required to inflate the lungs this uses more calories than normal and often interferes with feeding in infancy this condition as a constellation of findings is called congestive heart failure in some congenital heart defects such as in transposition of the great vessels a pda may need to remain open as it is the only way that oxygenated blood can mix with deoxygenated blood in these cases prostaglandins are used to keep the da open until surgical correction of the heart defect is completed
the paternò – büchi reaction named after emanuele paternò and george büchi who established its basic utility and form is a photochemical reaction that forms four membered oxetane rings from a carbonyl and an alkene with substrates benzaldehyde and 2 methyl 2 butene the reaction product is a mixture of structural isomers unsymmetric reaction another substrate set is benzaldehyde and furan
in mathematics a path in a topological space x is a continuous function f from the unit interval i 0 1 to x f i → x the initial point of the path is f 0 and the terminal point is f 1 one often speaks of a path from x to y where x and y are the initial and terminal points of the path note that a path is not just a subset of x which looks like a curve it also includes a parameterization for example the maps f x x and g x x 2 represent two different paths from 0 to 1 on the real line a loop in a space x based at x ∈ x is a path from x to x a loop may be equally well regarded as a map f i → x with f 0 f 1 or as a continuous map from the unit circle s 1 to x f s 1 → x this is because s 1 may be regarded as a quotient of i under the identification 0 ∼ 1 the set of all loops in x forms a space called the loop space of x a topological space for which there exists a path connecting any two points is said to be path connected any space may be broken up into a set of path connected components the set of path connected components of a space x is often denoted π 0 x one can also define paths and loops in pointed spaces which are important in homotopy theory if x is a topological space with basepoint x 0 then a path in x is one whose initial point is x 0 likewise a loop in x is one that is based at x 0
pathergy is a skin condition in which a minor trauma such as a bump or bruise leads to the development of skin lesions or ulcers that may be resistant to healing pathergy can also lead to ulcerations at the site of surgical incisions pathergy was seen with both behçet s disease and pyoderma gangrenosum a highly similar phenomenon known as koebner occurs in autoimmune diseases such as psoriasis and systemic lupus erythematosus among others doctors looking toward a diagnosis of behçet s disease may attempt to induce a pathergy reaction with a test known as a skin prick test the inflammation and ulceration that occurs as a result of pathergy in pyoderma gangrenosum often responds to systemic steroid therapy the pathergy reaction is a unique feature of behçet s disease and according to the international study group for behcet s disease is among the major criteria required for the diagnosis different positive pathergy reaction rates in bd have been reported worldwide when bd positive groups are studied for pathergy reaction the pathergy positive and pathergy negative bd groups showed a similar male female ratio age at disease onset and mean disease duration they also exhibited similar hla b 51 levels and a similar frequency of oral ulcerations in close family members the mucocutaneous manifestations systemic disease expression and severity score were similar in patients with and without the pathergy reaction the presence of a positive pathergy reaction is not associated with an increased risk for specific mucocutaneous or systemic manifestations of the disease and probably does not predict a more severe disease course it is also important to note that while a positive pathergy reaction helps to confirm a specific behçet s disease diagnosis a negative reaction does not invalidate a bd diagnosis because the disease process has to be active at the time of the skin prick test to produce a pathergy reaction differences in positive negative pathergy and severity of the reaction depend on disease activity ethnicity type of needle used for the prick test among other factors
pathogenic bacteria are bacteria that can cause infection this article deals with human pathogenic bacteria although most bacteria are harmless or often beneficial several are pathogenic one of the bacterial diseases with the highest disease burden is tuberculosis caused by the bacterium mycobacterium tuberculosis which kills about 2 million people a year mostly in sub saharan africa pathogenic bacteria contribute to other globally important diseases such as pneumonia which can be caused by bacteria such as streptococcus and pseudomonas and foodborne illnesses which can be caused by bacteria such as shigella campylobacter and salmonella pathogenic bacteria also cause infections such as tetanus typhoid fever diphtheria syphilis and leprosy pathogenic bacteria are also the cause of high infant mortality rates in developing countries koch s postulates are the standard to establish a causative relationship between a microbe and a disease
a pathologic fracture is a bone fracture caused by disease that led to weakness of the bone structure this process is most commonly due to osteoporosis but may also be due to other pathologies such as cancer infection inherited bone disorders or a bone cyst only a small number of conditions are commonly responsible for pathological fractures including osteoporosis osteomalacia paget s disease osteitis osteogenesis imperfecta benign bone tumours and cysts secondary malignant bone tumours and primary malignant bone tumours fragility fracture is a type of pathologic fracture that occurs as result of normal activities such as a fall from standing height or less there are three fracture sites said to be typical of fragility fractures vertebral fractures fractures of the neck of the femur and colles fracture of the wrist this definition arises because a normal human being ought to be able to fall from standing height without breaking any bones and a fracture therefore suggests weakness of the skeleton pathological fractures present as a chalkstick fracture in long bones and appear as a transverse fractures nearly 90 degrees to the long axis of the bone in a pathological compression fracture of a spinal vertebra fractures will commonly appear to collapse the entire body of vertebra in circumstances where other pathologies are excluded for example cancer a pathologic fracture is diagnostic of osteoporosis irrespective of bone mineral density
pathological demand avoidance pda or newson s syndrome is a proposed subtype of autism characterized by an avoidance of the ordinary demands of life it is identified as a syndrome through the clinical work of uk child psychologist elizabeth newson newson proposed it to be a specific pervasive developmental disorder pdd within the pdd family which is now loosely termed the autism spectrum pda is described as a distinct sub type of autism that responds to different treatment and handling guidelines than other conditions on the autistic spectrum however it is not currently recognised by either the dsm 5 or icd 10 some clinicians are increasingly prepared to diagnose children and some adults with pda when this profile fits the patient most accurately in the united kingdom there are suggested interventions that can be followed in order to help integrate pda children into the school system such as the distinctive clinical and educational needs of children with pathological demand avoidance syndrome guidelines for good practice by phil christie despite its lack of formal recognition the national autistic society a uk autism charity have produced a leaflet entitled what is pda in 2008
during an asthma episode inflamed airways react to environmental triggers such as smoke dust or pollen the airways narrow and produce excess mucus making it difficult to breathe in essence asthma is the result of an immune response in the bronchial airways the airways of asthma patients are hypersensitive to certain triggers also known as stimuli see below it is usually classified as type i hypersensitivity in response to exposure to these triggers the bronchi large airways contract into spasm an asthma attack inflammation soon follows leading to a further narrowing of the airways and excessive mucus production which leads to coughing and other breathing difficulties bronchospasm may resolve spontaneously in 1 – 2 hours or in about 50 of subjects may become part of a late response where this initial insult is followed 3 – 12 hours later with further bronchoconstriction and inflammation the normal caliber of the bronchus is maintained by a balanced functioning of the autonomic nervous system which both operates reflexively the parasympathetic reflex loop consists of afferent nerve endings which originate under the inner lining of the bronchus whenever these afferent nerve endings are stimulated for example by dust cold air or fumes impulses travel to the brain stem vagal center then down the vagal efferent pathway to again reach the bronchial small airways acetylcholine is released from the efferent nerve endings this acetylcholine results in the excessive formation of inositol 1 4 5 trisphosphate ip 3 in bronchial smooth muscle cells which leads to muscle shortening and this initiates bronchoconstriction
multiple sclerosis is an inflammatory demyelinating disease of the cns in which activated immune cells invade the central nervous system and cause inflammation neurodegeneration and tissue damage the underlying condition that produces this behaviour is currently unknown current research in neuropathology neuroimmunology neurobiology and neuroimaging together with clinical neurology provide support for the notion that ms is not a single disease but rather a spectrum there are three clinical phenotypes relapsing remitting ms rrms characterized by periods of neurological worsening following by remissions secondary progressive ms spms in which there is gradual progression of neurological dysfunction with fewer or no relapses and primary progressive ms ms in which there is neurological deterioration from onset pathophysiology is a convergence of pathology with physiology pathology is the medical discipline that describes conditions typically observed during a disease state whereas physiology is the biological discipline that describes processes or mechanisms operating within an organism referring to ms the physiology refers to the different processes that lead to the development of the lesions and the pathology refers to the condition associated with the lesions
a patrocladogram is a cladistic branching pattern that has been precisely modified by use of patristic distances i e divergences between lineages a type of phylogram the patristic distance is defined as the number of apomorphic step changes separating two taxa on a cladogram and is used exclusively to determine the amount of divergence of a characteristic from a common ancestor this means that cladistic and patristic distances are combined to construct a new tree using various phenetic algorithms the purpose of the patrocladogram in biological classification is to form a hypothesis about which evolutionary processes are actually involved before making a taxonomic decision patrocladograms are based on biostatistics that include but are not limited to parsimony distance matrix likelihood methods and bayesian probability some examples of genomically related data that can be used as inputs for these methods are molecular sequences whole genome sequences gene frequencies restriction sites distance matrices unique characters mutations such as snps and mitochondrial genome data
the pattern 1861 enfield was an alteration to the pattern 1853 enfield the alteration gave the pattern 1861 a faster twist 1 48 which gave it more accuracy than the longer infantry rifle in comparison to the pattern 1861 enfield it also had more grooves five groove rifling but what set it apart was its shortened barrel length of 610 mm making loading faster and carrying easier
pattern hair loss known as male pattern hair loss mphl when it affects males and female pattern hair loss fphl when it affects females is hair loss that primarily affects the top and front of the scalp in males the hair loss often presents as a receding hairline while in females it typically presents as a thinning of the hair male pattern hair loss is believed to be due to a combination of genetics and the male hormone dihydrotestosterone the cause in female pattern hair remains unclear treatment may include simply accepting the condition otherwise treatments may include minoxidil finasteride or hair transplant surgery evidence for finasteride in women however is poor and it may result in birth defects if taken during pregnancy pattern hair loss by the age of 50 affects about half of males and a quarter of females it is the most common cause of hair loss
patterson syndrome also called pseudoleprechaunism is an extremely rare syndrome first mistaken as donohue syndrome also known as leprechaunism it is named for dr joseph hanan patterson it was described by patterson and watkins in 1962 the pathogenesis and etiology of the patterson syndrome was unknown until 1981
patulous eustachian tube also known as patent eustachian tube is the name of a physical disorder where the eustachian tube which is normally closed instead stays intermittently open when this occurs the patient experiences autophony the hearing of self generated sounds these sounds such as one s own breathing voice and heartbeat vibrate directly onto the ear drum and can create a bucket on the head effect
pauci immune pauci latin few little vasculitis is a form of vasculitis that is associated with minimal evidence of hypersensitivity upon immunofluorescent staining for igg normally a kidney sample will be subjected to immunofluorescence if rapidly progressive glomerulonephritis is a concern in this case the immunofluorescence can show three patterns linear granular and negative pauci immune the linear and granular patterns are examples of positive immunofluorescence and are associated with goodpasture syndrome and post streptococcal glomerulonephritis accordingly a negative pattern or pauci immune pattern can be associated with systemic vasculitis such as microscopic polyangiitis eosinophilic granulomatosis with polyangiitis egpa or granulomatosis with polyangiitis gpa in many cases however it is limited to the kidney and it is thus called idiopathic since it can be associated with the three systemic vasculitides mentioned above a pauci immune pattern finding can be associated with antineutrophil cytoplasmic antibodies anca therefore an anca test should follow a negative immunofluorescence result in order to distinguish between the above mentioned systemic vasculitis peak incidences in 50 to 60 year olds symptoms include intermittent fever weight loss shortness of breath joint pain
the pauma complex is a prehistoric archaeological pattern among indigenous peoples of california initially defined by delbert l true in northern san diego county california the complex is dated generally to the middle holocene period this makes it locally the successor to the san dieguito complex predecessor to the late prehistoric san luis rey complex and contemporary with the la jolla complex on the san diego county coast pauma complex sites have been identified primarily in the san luis rey river valley and on the valley center plateau to the south of it archaeological traits distinguishing the pauma complex include a high frequency of shaped manos the presence of finely worked small domed scrapers the presence of knives and points the presence of discoidals and cogged stones a predominance of grinding tools over flaked tools a predominance of deep basin metates over slab metates a predominance of cobble hammers over core hammers a low frequency of cobble tools a scarcity of cobble choppers and cobble scrapers a predominance of volcanic rock over quartzite as a source material for flaked lithics an extreme scarcity of obsidian
the pauson – khand reaction or pkr or pk type reaction is a chemical reaction described as a 2 2 1 cycloaddition between an alkyne an alkene and carbon monoxide to form a α β cyclopentenone the reaction was discovered by ihsan ullah khand 1935 1980 who was working as a postdoctoral associate with peter ludwig pauson 1925 2013 at the university of strathclyde in glasgow this reaction was originally mediated by stoichiometric amounts of dicobalt octacarbonyl but newer versions are both more efficient and catalytic pk reaction with unsymmetrical alkenes or alkynes regioselectivity can be problematic but less so with intramolecular reactions pk reaction example the reaction works with both terminal and internal alkynes although internal alkynes tend to give lower yields the order of reactivity for the alkene is strained cyclic alkene terminal alkene disubstituted alkene trisubstituted alkene unsuitable alkenes are tetrasubstituted alkenes and alkenes with strongly electron withdrawing groups
the payatas landslide was a garbage dump collapse at payatas quezon city philippines on july 10 2000 that officially killed around 218 people and left thousands of people homeless many eyewitnesses note the number of people who died is much greater though up to 1 000 a large pile of garbage first collapsed and then went up in flames which resulted in the destruction of about 100 squatters houses
peace psychology is a subfield of psychology and peace research that deals with the psychological aspects of peace conflict violence and war peace psychology can be characterized by four interconnected pillars 1 research 2 education 3 practice and 4 advocacy the first pillar research is documented most extensively in this wiki entry peace psychological activities are based on psychological models theories and methods they are usually normatively bound in their means and objectives by working towards the ideal of sustainable peace using as far as possible non violent means violence and peace are usually defined in terms of johan galtung s extended conceptualization of peace according to which peace is not merely the absence of personal direct violence and war negative peace but also the absence of structural indirect and cultural violence positive peace the ideal of peace can also be conceptualized as the comprehensive implementation of human rights civil political economic social and cultural rights this should among other purposes ensure the satisfaction of basic human needs such as positive personal and social identity sense of control security social justice well being a safe environment and access to adequate food and shelter organizations that focus on peace psychology include for example in the united states the society for the study of peace conflict and violence peace psychology division division 48 of the american psychological association and psychologists for social responsibility a nongovernmental organization based in washington dc germany has the forum friedenspsychologie and the australian psychological society has an interest group called psychologists for peace on the international level there is the committee for the psychological study of peace as well as the international network of psychologists for social responsibility which links organizations from among other countries germany finland the united states australia costa rica india and italy
peach scab also known as peach freckles is a disease of stone fruits caused by the fungi cladosporium carpophilum the disease is most prevalent in wet and warm areas especially southern part of the u s as the fungi require rain and wind for dispersal the fungus causes scabbing lesions and defoliating on twig fruit and leaf resulting in downgrade of peach quality or loss of fruits due to rotting in severe cases
peakfit is an automated nonlinear peak separation and analysis software package for scientists performing spectroscopy chromatography and electrophoresis it automatically finds and fits up to 100 peaks to a data set at a time enabling users to characterize peaks and find the best equation that fits their data peakfit can also enhance the data obtained from traditional numerical methods and lab instruments peakfit was originally developed by ron brown of aisn software and distributed by jandel scientific software in the late 1980 s but by january 2004 systat software acquired the exclusive worldwide rights from spss inc to distribute sigmaplot and other sigma series products
peak bone mass is the maximum amount of bone a person has during their life it typically occurs in the early 20 s in both males and females a low peak bone mass is a risk factor for osteoporosis and may occur due to less than optimal bone growth peak bone mass is also typically lower in females than males as well as in white people and asians
peanut allergy is a type of food allergy to peanuts it is different from nut allergies physical symptoms of allergic reaction can include itchiness urticaria swelling eczema sneezing asthma abdominal pain drop in blood pressure diarrhea and cardiac arrest anaphylaxis may occur it is due to a type i hypersensitivity reaction of the immune system in susceptible individuals the allergy is recognized as one of the most severe food allergies due to its prevalence persistency and potential severity of allergic reaction in the united states peanut allergies are present in 0 6 of the population in western cultures peanut allergy is the most common cause of food related anaphylaxis death
pearson hashing is a hash function designed for fast execution on processors with 8 bit registers given an input consisting of any number of bytes it produces as output a single byte that is strongly dependent on every byte of the input its implementation requires only a few instructions plus a 256 byte lookup table containing a permutation of the values 0 through 255 this hash function is a cbc mac that uses an 8 bit substitution cipher implemented via the substitution table an 8 bitcipher has negligible cryptographic security so the pearson hash function is not cryptographically strong but it offers these benefits it is extremely simple it executes quickly on resource limited processors there is no simple class of inputs for which collisions identical outputs are especially likely given a small privileged set of inputs e g reserved words for a compiler the permutation table can be adjusted so that those inputs yield distinct hash values producing what is called a perfect hash function two input strings differing by exactly one character never collide have identical outputs e g applying the algorithm on the strings abc and aec will never produce the same value one of its drawbacks when compared with other hashing algorithms designed for 8 bit processors is the suggested 256 byte lookup table which can be prohibitively large for a small microcontroller with a program memory size on the order of hundreds of bytes a workaround to this is to use a simple permutation function instead of a table stored in program memory however using a too simple function such as t i 255 i partly defeats the usability as a hash function as anagrams will result in the same hash value using a too complex function on the other hand will affect speed negatively the algorithm can be described by the following pseudocode which computes the hash of message c using the permutation table t h 0 for each c in c loop index h xor c h t index end loopreturn h
pearson syndrome is a mitochondrial disease characterized by sideroblastic anemia and exocrine pancreas dysfunction other clinical features are failure to thrive pancreatic fibrosis with insulin dependent diabetes and exocrine pancreatic deficiency muscle and neurologic impairment and frequently early death it is usually fatal in infancy the few patients who survive into adulthood often develop symptoms of kearns sayre syndrome it is caused by a deletion in mitochondrial dna pearson syndrome is very rare less than hundred cases have been reported in medical literature worldwide the syndrome was first described by pediatric hematologist and oncologist howard pearson in 1979 the deletions causing it were discovered a decade later
the pearson – anson effect discovered in 1922 by stephen oswald pearson and horatio saint george anson is the phenomenon of an oscillating electric voltage produced by a neon bulb connected across a capacitor when a direct current is applied through a resistor this circuit now called the pearson anson oscillator neon lamp oscillator or sawtooth oscillator is one of the simplest types of relaxation oscillator it generates a sawtooth output waveform it has been used in low frequency applications such as blinking warning lights stroboscopes tone generators in electronic organs and other electronic music circuits and in time bases and deflection circuits of early cathode ray tube oscilloscopes since the development of microelectronics these simple negative resistance oscillators have been superseded in many applications by more flexible semiconductor relaxation oscillators such as the 555 timer ic
peasant armament support march of 1914 swedish bondetåget was a manifestation primarily by swedish farmers held on february 6 th 1914 in stockholm it resulted in a constitutional crisis triggered by the courtyard speech held by king gustav v to the marchers at the royal palace
peat turf is an accumulation of partially decayed vegetation or organic matter that is unique to natural areas called peatlands bogs or mires the peatland ecosystem is the most efficient carbon sink on the planet because peatland plants capture the co 2 which is naturally released from the peat thus maintaining an equilibrium in natural peatlands the annual rate of biomass production is greater than the rate of decomposition but it takes thousands of years for peatlands to develop the deposits of 1 5 to 2 3 m 4 9 to 7 5 ft which is the average depth of the boreal peatlands one of the most common components is sphagnum moss although many other plants can contribute soils that contain mostly peat are known as histosols peat forms in wetland conditions where flooding obstructs flows of oxygen from the atmosphere slowing rates of decomposition peatlands also known as mires particularly bogs are the most important source of peat but other less common wetland types also deposit peat including fens pocosins and peat swamp forests other words for lands dominated by peat include moors or muskegs landscapes covered in peat also have specific kinds of plants particularly sphagnum moss ericaceous shrubs and sedges see bog for more information on this aspect of peat since organic matter accumulates over thousands of years peat deposits also provide records of past vegetation and climates stored in plant remains particularly pollen hence they allow humans to reconstruct past environments and changes in human land use peat is harvested as an important source of fuel in certain parts of the world by volume about 4 trillion cubic metres 5 2 trillion cubic yards of peat are in the world covering a total of around 2 of global land area about 3 million square kilometres or 1 2 million square miles containing about 8 billion terajoules of energy over time the formation of peat is often the first step in the geological formation of other fossil fuels such as coal particularly low grade coal such as lignite depending on the agency peat is not generally regarded as a renewable source of energy as its extraction rate in industrialized countries far exceeds its slow regrowth rate of 1 mm per year 0 039 in and as peat regrowth is also reported to take place in only 30 40 of peatlands because of this the united nations framework convention on climate change unfccc and another organization affiliated with the united nations classifies peat as a fossil fuel however the intergovernmental panel on climate change has begun to classify peat as a slow renewable fuel this is also the classification used by many in the peat industry at 106 g co 2 mj the carbon dioxide emission intensity of peat is higher than that of coal at 94 6 g co 2 mj and natural gas at 56 1 peat fires have been responsible for some large public health disasters including the 1997 southeast asian haze
peat fire cancer is a cutaneous condition that may develop on the shins of women due to hydrocarbon fueled heat exposure from coal fired clothing warmers
the pebibit is a multiple of the bit a unit of digital information storage prefixed by the standards based multiplier pebi symbol pi a binary prefix meaning 250 the unit symbol of the pebibit is pibit 1 pebibit 250 bits 1125899906842624 bits 1024 tebibits the pebibit is closely related to the petabit the corresponding unit using the metric prefix peta which is 1015 bits
the pebibyte is a multiple of the unit byte for digital information it is a member of the set of units with binary prefixes defined by the international electrotechnical commission iec its unit symbol is pib the prefix pebi symbol pi represents multiplication by 10245 therefore 1 pebibyte 250 bytes 1125899906842624 bytes 1024 tebibytes the pebibyte is closely related to the petabyte pb its corresponding unit in the decimal set of multiples defined in the international system of units si and which represents 1015 bytes 1000000000000000 bytes it follows that one pebibyte 1 pib is approximately equal to 1 13 pb
pecan anthracnose is a fungal disease of pecan trees caused by the ascomycete glomerella cingulata stoneman spauld h it is a widespread disease found wherever pecan trees are grown pecan anthracnose has been reported as far back in time as 1914 rand 1914 and as far away as argentina mantz minhot et al 2010 glomerella cingulata has two anamorphs which cause disease on pecan trees colletotrichum gloeosporioides and colletotrichum acutatum latham 1995 the occurrence of colletotrichum on pecans has contributed to a significant decline in pecan production in various years an increase in the incidence of pecan anthracnose is highly correlated with heavy rainfall especially heavy rainfall occurring in early spring the severity of symptoms increases as the season progresses often culminating in leaf drop in the late autumn this defoliation is linked to lower yield and poorer quality of nuts brenneman 2010
pectus carinatum l carīnātus equiv to carīn a keel also called pigeon chest is a deformity of the chest characterized by a protrusion of the sternum and ribs it is distinct from the related deformity pectus excavatum
pectus excavatum is a congenital deformity of the anterior thoracic wall in which the sternum and rib cage grow abnormally this produces a caved in or sunken appearance of the chest it can either be present at birth or not develop until puberty pectus excavatum is sometimes considered to be cosmetic but depending on the severity it can impair cardiac and respiratory function and cause pain in the chest and back people with the condition may experience negative psychosocial effects and avoid activities that expose the chest pectus excavatum is from latin meaning hollowed chest it is sometimes referred to as cobbler s chest or funnel chest
pedagogical patterns are high level patterns that have been recognized in many areas of training and pedagogy such as group work software design human computer interaction education and others the concept is an extension of pattern languages in both cases the patterns seek to foster best practices of teaching according to joseph bergin “ the intent of pedagogical patterns is to capture the essence of the practice in a compact form that can be easily communicated to those who need the knowledge presenting this information in a coherent and accessible form can mean the difference between every new instructor needing to relearn what is known by senior faculty and easy transference of knowledge of teaching within the community “ although widespread in the software industry the use of patterns is still emerging in the educational field whereas software developers make regular use of mature patterns the educational community as a whole is still far from including patterns in the everyday tool box mitchell weisburgh has made an effort to define pedagogical content in terms of design patterns in documenting good education and training practices through design patterns he proposes nine aspects to documenting a pattern for a certain skill not every pattern needs to include all nine his listing is reproduced below name – single word or short phrase that refers to the pattern this allows for rapid association and retrieval problem – definition of a problem including its intent or a desired outcome and symptoms that would indicate that this problem exists context – preconditions which must exist in order for that problem to occur this is often a situation when forces conflict the resolutions of those conflicts is often implied by the context forces – description of forces or constraints and how they interact some of the forces may be contradictory for example being thorough often conflicts with time or money constraints solution – instructions possibly including variants the solution may include pictures diagrams prose or other media examples – sample applications and solutions analogies visual examples and known uses can be especially helpful help user understand the context resulting context – result after the pattern has been applied including postconditions and side effects it might also include new problems that might result from solving the original problem rationale – the thought processes that would go into selecting this pattern the rationale includes an explanation of why this pattern works how forces and constraints are resolved to construct a desired outcome related patterns – differences and relationships with other patterns possibly predecessor antecedents or alternatives that solve similar problems
pediatric acute onset neuropsychiatric syndrome pans is a neuropsychiatric syndrome still under research leading to rapid onset obsessive compulsive disorder ocd and or tics in children and adolescents it may be either connected to group a streptococcal infections pandas sub group or caused by immunologic reactions to other pathogens pitands sub group affecting the basal ganglia this portion of the brain is responsible for mediating cognition emotion and movement research into the etiology of obsessive compulsive disorder has identified dysfunctions of the basal ganglia as a key factor for the onset of ocd a similar syndrome in adults is known as post inflammatory brain syndrome pibs
pediatric schizophrenia also known as childhood schizophrenia childhood onset schizophrenia and early onset schizophrenia is a type of mental disorder that is characterized by degeneration of thinking motor and emotional processes with onset before age 18 early onset or before age 13 very early onset the disease presents symptoms such as auditory and visual hallucinations strange thoughts or feelings and abnormal behavior profoundly impacting the childs ability to function and sustain normal interpersonal relationships it typically presents after the age of seven about 50 of young children diagnosed with schizophrenia experience severe neuropsychiatric symptoms diagnostic criteria are similar to those of adult schizophrenia diagnosis is based on behavior observed by caretakers and in some cases depending on age self reports schizophrenia has no definite cause however certain risk factors such as family history seem to correlate there is no known cure but childhood schizophrenia is controllable with the help of behavioral therapies and medications
pediatric trauma refers to a traumatic injury that happens to an infant child or adolescent because of anatomical and physiological differences between children and adults the care and management of this population differs
pediculosis is an infestation of lice blood feeding ectoparasitic insects of the order phthiraptera the condition can occur in almost any species of warm blooded animal i e mammals and birds including humans although pediculosis in humans may properly refer to lice infestation of any part of the body the term is sometimes used loosely to refer to pediculosis capitis the infestation of the human head with the specific head louse
pediculosis corporis also known as pediculosis vestimenti and vagabond s disease is a cutaneous condition caused by body lice specifically pediculus corporis that lay their eggs in the seams of clothing
pediculosis pubis also known as crabs and pubic lice is a disease caused by the pubic louse pthirus pubis a parasitic insect notorious for infesting human pubic hair the species may also live on other areas with hair including the eyelashes causing pediculosis ciliaris infestation usually leads to intense itching in the pubic area treatment with topic agents such as permethrin or pyrethrin with piperonyl butoxide is exceedingly effective worldwide it affects about 2 of the population
pedophilia or paedophilia is a psychiatric disorder in which an adult or older adolescent experiences a primary or exclusive sexual attraction to prepubescent children although girls typically begin the process of puberty at age 10 or 11 and boys at age 11 or 12 criteria for pedophilia extend the cut off point for prepubescence to age 13 a person who is diagnosed with pedophilia must be at least 16 years old but adolescents must be at least five years older than the prepubescent child for the attraction to be diagnosed as pedophilia pedophilia is termed pedophilic disorder in the diagnostic and statistical manual of mental disorders dsm 5 and the manual defines it as a paraphilia involving intense and recurrent sexual urges towards and fantasies about prepubescent children that have either been acted upon or which cause the person with the attraction distress or interpersonal difficulty the international classification of diseases icd 10 defines it as a sexual preference for children of prepubertal or early pubertal age in popular usage the word pedophilia is often applied to any sexual interest in children or the act of child sexual abuse this use conflates the sexual attraction to prepubescent children with the act of child sexual abuse and fails to distinguish between attraction to prepubescent and pubescent or post pubescent minors researchers recommend that these imprecise uses be avoided because although people who commit child sexual abuse sometimes exhibit the disorder child sexual abuse offenders are not pedophiles unless they have a primary or exclusive sexual interest in prepubescent children and the literature indicates the existence of pedophiles who do not molest children pedophilia was first formally recognized and named in the late 19 th century a significant amount of research in the area has taken place since the 1980 s although mostly documented in men there are also women who exhibit the disorder and researchers assume available estimates underrepresent the true number of female pedophiles no cure for pedophilia has been developed but there are therapies that can reduce the incidence of a person committing child sexual abuse the exact causes of pedophilia have not been conclusively established some studies of pedophilia in child sex offenders have correlated it with various neurological abnormalities and psychological pathologies in the united states following kansas v hendricks sex offenders who are diagnosed with certain mental disorders particularly pedophilia can be subject to indefinite civil commitment
peduncular hallucinosis ph or lhermitte s peduncular hallucinosis is a rare neurological disorder that causes vivid visual hallucinations that typically occur in dark environments and last for several minutes unlike some other kinds of hallucinations the hallucinations that patients with ph experience are very realistic and often involve people and environments that are familiar to the affected individuals because the content of the hallucinations is never exceptionally bizarre patients can rarely distinguish between the hallucinations and reality in 1922 the french neurologist jean lhermitte documented the case of a patient who was experiencing visual hallucinations that were suggestive of localized damage to the midbrain and pons after other similar case studies were published this syndrome was labeled peduncular hallucinosis the accumulation of additional cases by lhermitte and by others influenced academic medical debate about hallucinations and about behavioral neurology lhermitte provided a full account of his work in this area in his book les hallucinations clinique et physiopathologie which was published in paris in 1951 by doin publishing contemporary researchers with access to new technologies in medical brain imaging have confirmed the brain localization of these unusual hallucinations
peeling skin syndrome also known as acral peeling skin syndrome continual peeling skin syndrome familial continual skin peeling idiopathic deciduous skin and keratolysis exfoliativa congenita is an autosomal recessive disorder characterized by lifelong peeling of the stratum corneum and may be associated with pruritus short stature and easily removed anagen hair the acral form can be associated with tgm 5
pel ebstein fever also known as ebstein cardarelli fever is a rarely seen condition noted in patients with hodgkin s lymphoma in which the patient experiences fevers which cyclically increase then decrease over an average period of one or two weeks a cyclic fever may also be associated with other conditions but it is not called pel ebstein fever unless the fever is associated with hodgkin s
pelger – huët anomaly pronunciation pel ′ gər hyo̅o̅ ′ ət is a blood laminopathy associated with the lamin b receptor it is characterized by a white blood cell type known as a neutrophil whose nucleus is hyposegmented it is a genetic disorder with an autosomal dominant inheritance pattern heterozygotes are clinically normal although their neutrophils may be mistaken for immature cells which may cause mistreatment in a clinical setting homozygotes tend to have neutrophils with rounded nuclei that do have some functional problems
peliculu in mora latin for danger in delay is one of two conditions which must be asserted in actions aimed at obtaining a protective order or injunction e g art 700 former ccp to be granted the relief sought the other condition being fumus boni iuris the second condition is the c d prima facie case the burden of proof of danger in delay falls to the person who requests the injunction or order demonstrating the existence of both requirements pericolum notice and the risk of suffering serious and irreparable damage the term serious harm refers to the magnitude of the damages calculated in relation to the value of the property in dispute an injury will not be so serious in itself but only when compared to the object of contention irreparable damage is in the possibility of a remedy in the future against which the party seeking the injunction believes they will suffer only asset orientation is currently supported in that the prevailing possibility of obtaining compensation for damages is in itself sufficient to prevent the founding of irreparable harm
peliosis hepatis is an uncommon vascular condition characterised by multiple randomly distributed blood filled cavities throughout the liver the size of the cavities usually ranges between a few millimetres to 3 cm in diameter in the past it was a mere histological curiosity occasionally found at autopsies but has been increasingly recognised with wide ranging conditions from aids to the use of anabolic steroids it also occasionally affects spleen lymph nodes lungs kidneys adrenal glands bone marrow and other parts of gastrointestinal tract peliosis hepatis is often erroneously written peliosis hepatitis despite its not being one of the hepatitides the correct term arises from the greek pelios i e discoloured by extravasated blood livid and the latinized genitive case hepatis of the greek hepar liver
pelizaeus – merzbacher disease pmd is a rare central nervous system disorder in which coordination motor abilities and intellectual function are delayed to variable extents
pellagra is a vitamin deficiency disease most frequently caused by a chronic lack of niacin vitamin b 3 or vitamin pp from pellagra preventing factor in the diet it can be caused by decreased intake of niacin or tryptophan and possibly by excessive intake of leucine it may also result from alterations in protein metabolism in disorders such as carcinoid syndrome or hartnup disease a deficiency of the amino acid lysine can lead to a deficiency of niacin as well
a pellicle is a skin or coating of proteins on the surface of meat fish or poultry which allow smoke to better adhere the surface of the meat during the smoking process useful in all smoking applications and with any kind of animal protein it is best used with fish where the flesh of say salmon forms a pellicle the surface that will attract more smoke to adhere to it than would be the case if it had not been used without a pellicle the fish would be inedibly dry from enough smoking to produce a tasty finished product it is the pellicle which permits the transformation creating delectable smoked salmon
the pellizzari reaction was discovered in 1911 by guido pellizzari and is the organic reaction of an amide and a hydrazide to form a 1 2 4 triazole the product is similar to that of the einhorn brunner reaction but the mechanism itself is not regioselective an overview of the pellizzari reaction
pellucid marginal degeneration pmd is a degenerative corneal condition often confused with keratoconus it is typically characterized by a clear bilateral thinning ectasia in the inferior and peripheral region of the cornea although some cases affect only one eye the cause of the disease remains unclear idiopathic the term pellucid marginal degeneration was first coined in 1957 by the ophthalmologist schalaeppi the word pellucid means clear indicating that the corneas retain clarity in pellucid marginal degeneration
pelopsia is a vision perception disorder in which objects appear nearer than they actually are pelopsia can be caused by psychoneurotic phenomena changes in atmospheric clarity or sometimes by wearing a corrective lens
pelvic congestion syndrome also known as pelvic vein incompetence is a chronic medical condition in women caused by varicose veins in the lower abdomen the condition causes chronic pain often manifesting as a constant dull ache which can be aggravated by standing early treatment options include pain medication alternative therapies such as acupuncture and suppression of ovarian function surgery can be done using noninvasive transcatheter techniques to embolize the varicose veins up to 80 of women obtain relief using this method the condition can occur as a result of pregnancy or for unknown reasons the presence of estrogen in the body causes vasodilation which can result in the accumulation of blood in the veins in the pelvic area estrogen can weaken the vein walls leading to the changes that cause varicosities up to 15 of all women have varicose veins in the abdominal area but not all have symptoms
a pelvic digit pelvic finger or pelvic rib is a rare congenital abnormality in humans in which bone tissue develops in the soft tissue near the pelvis resembling a rib or finger and often divided into one or more segments with pseudo articulations pelvic digits are typically benign and asymptomatic and are usually discovered accidentally approximately 41 cases have been reported the pelvic digit was first reported by d sullivan and w s cornwell in 1974 pelvic digits may be located at any level of the pelvis the lower ribs or even the anterior abdominal wall it is theorized that pelvic digit anomalies arise during the mesenchymal stage of bone growth within the first six weeks of embryogenesis their formation may result from a failure of the primordium of the coccyx to fuse to the vertebral column leading to the independent development of a proto rib structure
pelvic floor dysfunction refers to a wide range of issues that occur when muscles of the pelvic floor are weak tight or there is an impairment of the sacroiliac joint lower back coccyx or hip joints symptoms include pelvic pain pressure dyspareunia incontinence incomplete emptying and gross organ protrusion tissues surrounding the pelvic organs may have increased or decreased sensitivity or irritation resulting in pelvic pain many times the underlying cause of pelvic pain is difficult to determine the condition affects up to 50 of women pelvic floor dysfunction may include any of a group of clinical conditions that includes urinary incontinence fecal incontinence pelvic organ prolapse sensory and emptying abnormalities of the lower urinary tract defecatory dysfunction sexual dysfunction and several chronic pain syndromes including vulvodynia the three most common and definable conditions encountered clinically are urinary incontinence anal incontinence and pelvic organ prolapse
pelvic fracture is a disruption of the bony structure of the pelvis including the hip bone sacrum and coccyx the most common cause in the elderly is a fall but the most significant fractures involve high energy forces such as a motor vehicle crashes cycling accidents or a fall from significant height diagnosis is made on the basis of history clinical features and special investigations usually including x ray and ct because the pelvis cradles so many internal organs pelvic fractures may produce significant internal bleeding which is invisible to the eye emergency treatment consists of advanced trauma life support management after stabilisation the pelvis may be surgically reconstructed
pelvic inflammatory disease or pelvic inflammatory disorder pid is an infection of the upper part of the female reproductive system namely the uterus fallopian tubes and ovaries and inside of the pelvis often there may be no symptoms signs and symptoms when present may include lower abdominal pain vaginal discharge fever burning with urination pain with sex or irregular menstruation untreated pid can result in long term complications including infertility ectopic pregnancy chronic pelvic pain and cancer the disease is caused by bacteria that spread from the vagina and cervix infections by neisseria gonorrhoeae or chlamydia trachomatis are present in 75 to 90 percent of cases often multiple different bacteria are involved without treatment about 10 percent of those with a chlamydial infection and 40 percent of those with a gonorrhea infection will develop pid risk factors are similar to those of sexually transmitted infections generally and include a high number of sexual partners and drug use vaginal douching may also increase the risk the diagnosis is typically based on the presenting signs and symptoms it is recommended that the disease be considered in all women of childbearing age who have lower abdominal pain a definitive diagnosis of pid is made by finding pus involving the fallopian tubes during surgery ultrasound may also be useful in diagnosis efforts to prevent the disease include not having sex or having few sexual partners and using condoms screening women at risk for chlamydial infection followed by treatment decreases the risk of pid if the diagnosis is suspected treatment is typically advised treating a woman s sexual partners should also occur in those with mild or moderate symptoms a single injection of the antibiotic ceftriaxone along with two weeks of doxycycline and possibly metronidazole by mouth is recommended for those who do not improve after three days or who have severe disease intravenous antibiotics should be used globally about 106 million cases of chlamydia and 106 million cases of gonorrhea occurred in 2008 the number of cases of pid however is not clear it is estimated to affect about 1 5 percent of young women yearly in the united states pid is estimated to affect about one million people yearly a type of intrauterine device iud known as the dalkon shield led to increased rates of pid in the 1970 s current iuds are not associated with this problem after the first month
the rare disease pelvic lipomatosis is most often seen in older obese black men with hypertension in pelvic lipomatosis abnormally dense deposits of otherwise apparently normal fat may be observed in the spaces of the pelvic area associated with cystitis glandularis a precursor to adenocarcinoma of the urinary bladder
pelvic pain is pain in the area of the pelvis acute pain is more common than chronic pain if the pain lasts for more than six months it is deemed to be chronic pelvic pain it can affect both women and men common causes in include endometriosis in women bowel adhesions irritable bowel syndrome and interstitial cystitis the cause may also be a number of poorly understood conditions that may represent abnormal psychoneuromuscular function
a pelvic tumor is any one of numerous tumors that occur in the pelvis within the pelvis these tumors may involve specific organs or occupy intra organ spaces tumors of the presacral space and sacral space are most prevalent in children tumors occupying specific organs have a more complex natural history
pelvis justo major also called giant pelvis is a rare condition of the adult female pelvis where the pelvis is 1 5 or more times larger than an average pelvis in every direction and is at least 42 cm 16 5 inches biiliac width even though this condition is classified as a congenital abnormality it is not a medical disease or abnormality of the pelvis as the pelvis is a true gynecoid shape only larger women with this condition frequently at the time of delivery have a precipitous birth there is virtually no resistance of the huge pelvic opening to the size of a newborn so only the soft parts resist the birth with a huge justo major pelvis there is no pelvic bone molding of the fetal head with the average pelvic size 2 3 or less justo major size the usual pelvic molding process slows the birth resulting in a slow and gradual stretching of the vaginal opening for primiparous women when a huge justo major pelvis allows such an extremely rapid vaginal birth there can be tears of the perineal soft tissues at the time of delivery the strong uterine contractions and maternal bearing down almost instantly overwhelm the integrity of a tightened and previously unstretched vaginal orifice this is often the case if such women have not previously practiced vaginal stretching to the degree that allows such an instant birthing especially so for a primiparous woman this instant delivery problem causes many obgyn doctors to stress the importance of women with a huge pelvis practicing pre delivery vaginal stretching to avoid perineal injury such a large size for the female pelvis is present in less than one in a thousand adult women when women reach their maximum pelvis size often by 21 years of age if they have a huge pelvis the resulting big hips will not go away — no matter how much they diet as bone will not shrink it is not unusual for such women whose pear shape is due to a huge pelvis to give up watching calories for smaller hips leading to obesity however such pear shaped obese women do not necessarily have a huge pelvis and a measurement scan or anthropometry by calipers is required to diagnose the justo major condition the incidence of justo major pelvis is not found to be a strictly standard deviation type variation as it follows a tail skewed deviation to the right incidence varies with geographic regions of the world e g poland has a high incidence justo major pelvis is classified as congenital and thought to be partially inherited especially from the maternal side
peléan eruptions are a type of volcanic eruption they can occur when viscous magma typically of rhyolitic or andesitic type is involved and share some similarities with vulcanian eruptions the most important characteristic of a peléan eruption is the presence of a glowing avalanche of hot volcanic ash a pyroclastic flow formation of lava domes is another characteristical feature short flows of ash or creation of pumice cones may be observed as well the initial phases of eruption are characterized by pyroclastic flows the tephra deposits have lower volume and range than the corresponding plinian and vulcanian eruptions the viscous magma then forms a steep sided dome or volcanic spine in the volcano s vent the dome may later collapse resulting in flows of ash and hot blocks the eruption cycle is usually completed in a few years but in some cases may continue for decades like in the case of santiaguito the 1902 explosion of mount pelée is the first described case of a peléan eruption and gave it its name some other examples include the following the 1948 1951 eruption of hibok hibok the 1951 eruption of mount lamington which remains the most detailed observation of this kind the 1956 eruption of bezymianny the 1968 eruption of mayon volcano and the 1980 eruption of mount st helens
pemphigoid is a group of rare autoimmune blistering skin diseases as its name indicates pemphigoid is similar in general appearance to pemphigus but unlike pemphigus pemphigoid does not feature acantholysis a loss of connections between skin cells pemphigoid is more common than pemphigus and is slightly more common in women than in men it is also more common in people over 60 years of age than it is in younger people
pemphigoid nodularis is a cutaneous condition that is a variant of bullous pemphigoid that has skin lesions mimicking prurigo nodularis the antibody involved is igg
pemphigus ˈpɛmfɪɡəs or pɛmˈfaɪɡəs is a rare group of blistering autoimmune diseases that affect the skin and mucous membranes in pemphigus autoantibodies form against desmoglein desmoglein forms the glue that attaches adjacent epidermal cells via attachment points called desmosomes when autoantibodies attack desmogleins the cells become separated from each other and the epidermis becomes unglued a phenomenon called acantholysis this causes blisters that slough off and turn into sores in some cases these blisters can cover a significant area of the skin originally the cause of this disease was unknown and pemphigus was used to refer to any blistering disease of the skin and mucosa in 1964 researchers found that the blood of patients with pemphigus contained antibodies to the layers of skin that separates to form the blisters in 1971 an article investigating the autoimmune nature of this disease was published
pemphigus erythematosus also known as senear – usher syndrome is simply a localized form of pemphigus foliaceuswith features of lupus erythematosus
pemphigus foliaceus is an autoimmune blistering disease of the skin with characteristic lesions that are scaly crusted erosions often on an erythematous base mucosal involvement is absent even with widespread disease if there is an autoimmune igg buildup in the epidermis then nearly all of the antibodies are aimed against desmoglein 1 the effect of the antibodies and the immunological pathway is most likely either of three mechanisms steric hindrance of the desmoglein 1 the antibody caps off the site for intracellular binding to another keratinocyte activation of an endocytic pathway the antibody activates a pathway which causes an internalization of desmogleïn 1 which in turn causes a loss of adhesion disruption of function in this case the antibody blocks the desmoglein 1 from being formed into a desmosome this in turn causes a loss of adhesion with acantholysis as a result
pemphigus herpetiformis also known as acantholytic herpetiform dermatitis herpetiform pemphigus mixed bullous disease and pemphigus controlled by sulfapyridine is a cutaneous condition a clinical variant of pemphigus that combines the clinical features of dermatitis herpetiformis with the immunopathologic features of pemphigus pathophysiology pemphigus herpetiformis is an igg mediated autoantibodies that affect the epidermal layer of the skin
pemphigus vegetans is a localized form of pemphigus vulgaris in which there is a localized vegetating papillomatous response the eroded areas do not heal like usual but form papillomatous growth and vegetation accounts for 1 2 of pemphigus cases and is a relatively benign variant of pemphigus vulgaris two forms are recognized pemphigus vegetans of neumann is a localized disease of pemphigus vulgaris slightly more extensive than pemphigus vegetans of hallopeau this type is more common and characterized by early lesions similar to pemphigus vulgaris with large bullae and erosive areas healing is through formation of granulation tissue pemphigus vegetans of hallopeau is a disease of localized pemphigus vulgaris it is named for françois henri hallopeau this type is less aggressive and has pustules not bullae these pustules heal by verrucios hyperkeratotic vegetations
pemphigus vulgaris is a rare chronic blistering skin disease it is classified as a type ii hypersensitivity reaction with the formation of antibodies against desmosomes components of the skin that function to keep certain layers of skin bound to each other as desmosomes are attacked the layers of skin separate and the clinical picture resembles a blister over time the condition inevitably progresses without treatment lesions increase in size and distribution throughout the body behaving physiologically like a severe burn before the advent of modern treatments mortality for the disease was close to 90 today the mortality rate with treatment is between 5 15
in australian law a penalty unit abbreviated as pu is an amount of money used to compute pecuniary penalties for many breaches of statute law fines are calculated by multiplying the value of one penalty unit by the number of penalty units prescribed for the offence the different jurisdictions that make up australia the commonwealth and the states and territories each have their own penalty units the value of a penalty unit and the manner and frequency of varying that value differ from state to state and there are also federal penalty units that apply only to federal offences in the state of victoria the value of a penalty unit is the amount fixed with respect to a financial year by the treasurer by notice published in the government gazette under the monetary units act 2004 the penalty unit rate is fixed at a 155 46 as of 1 july 2016 therefore a fine defined as 100 penalty units would incur a penalty of 15 546 rounded to the nearest 10 cents one penalty unit in new south wales is 110 one penalty unit in queensland is 121 90 in the state of tasmania the value of a penalty unit is adjusted for each financial year based on consumer price index cpi movements in the previous year and published in the tasmanian government gazette before 1 june for the next financial year in the 2017 financial year it is 157 under australian federal law a penalty unit for an individual is 180 as of 31 july 2015 western australian penalty units vary across the legislation most are listed as a dollar figure in the legislation but road offences incur a penalty unit of 50 south australia does not have penalty units instead fine amounts are listed in the legislation
penamaluru is an out growth to vijayawada in krishna district of the indian state of andhra pradesh it is the mandal headquarters of penamaluru mandal in vijayawada revenue division and also forms a part of vijayawada urban agglomeration
pendred syndrome or pendred disease is a genetic disorder leading to congenital bilateral both sides sensorineural hearing loss and goitre with euthyroid or mild hypothyroidism decreased thyroid gland function there is no specific treatment other than supportive measures for the hearing loss and thyroid hormone supplementation in case of hypothyroidism it is named after dr vaughan pendred 1869 – 1946 the english doctor who first described the condition in an irish family living in durham in 1896 it accounts for 7 5 of all cases of congenital deafness
penetrants or penetrating items are the mechanical electrical or structural items that pass through an opening in a wall or floor such as pipes electrical conduits ducting cables and cable trays or structural steel beams and columns when these items pierce a wall or floor assembly they create a space between the penetrant and the surrounding structure which can become an avenue for the spread of fire between rooms or floors modern building codes generally require a service penetration firestop to seal the openings around penetrants or services in order to restore the fire resistance rating of the parent assembly sizing of all openings has significant impact upon the adherence to the certification listing requirements therefore communication between all affected trades is of great importance before any openings are made to ensure proper sizing of the openings for cost control and conformance with listing and approval use and compliance penetrants are typically accommodated by plumbers and electricians who prepare for them by installing sleeves in concrete walls and floors before they are poured in the case of masonry walls electricians and plumbers tend to be there first and hang sleeves around their piping ductwork and conduit where they know from their drawings that block walls will be erected in order to avoid the time and expense of having to cut openings in existing walls and floors in the case of drywall assemblies the opening size is determined by the drywall contractor unless the mechanical and electrical trades are contractually obliged to provide sleeving here as well with proper fastening methods that are in conformance with the certification listing it is not uncommon for these trades to attempt to absolve themselves of the requirement to firestop their openings in the drywall assemblies by claiming that they were there first meaning that others should take care of the rest since drywall contractors are not ordinarily required to do mechanical and electrical firestopping the drywall openings can become an item of dispute or neglect particularly in north american construction this common issue can be minimised by designating a separate firestopping sub contract whereby a separate speciality sub contractor firestops all openings on site mechanical electrical and structural as well as the building joints timber floor openings are simply cut by means of a chainsaw in this case the width of the blade will determine sizes electrical cable through penetration firestopped by an intumescent sealant to restore the two hour fire resistance rating of the concrete floor steel beam through penetration the firestop surrounding the beam is incomplete packing only sealant is yet to be applied the beam itself must be treated with fireproofing to prevent it from twisting and damaging the wall during a fire sprinkler branch pipe through penetration with plastic sleeve missing firestop in concrete fire separation the branch pipe is a penetrant as is the plastic sleeve which is a code violation if left in place unless it is in conformance with a firestop certification listing that permits such sleeving cable tray cross barrier firestop test full scale wall in germany as per din 4102 examples of common firestop penetrant problems a typical fire problem — the measures taken by the plumbers and the drywallers are at cross purposes another example this steel sleeve a penetrant causes more problems than it solves penetrants have been punched and burned through drywall compromising its integrity mechanical shaft with compromised fire resistance rating through pipe installation finished painted fire resistance rated drywall assembly a common deficiency lift ceiling tiles and find electrical and mechanical service penetrations without a firestop improper drywall and absent firestops improper firestop and fireproofing interface august 2000 improper breach of fire resistance rated drywall assembly august 2000 the i was there first scenario resulting in improper drywall firestops with plastic piping
a penetrating atherosclerotic ulcer pau is an atherosclerotic lesion that ulcerates leading to a hematoma forming within the walls of the aorta
a penetrating head injury or open head injury is a head injury in which the dura mater the outer layer of the meninges is breached penetrating injury can be caused by high velocity projectiles or objects of lower velocity such as knives or bone fragments from a skull fracture that are driven into the brain head injuries caused by penetrating trauma are serious medical emergencies and may cause permanent disability or death a penetrating head injury involves a wound in which an object breaches the cranium but does not exit it in contrast a perforating head injury is a wound in which the object passes through the head and leaves an exit wound
penetrating trauma is an injury that occurs when an object pierces the skin and enters a tissue of the body creating an open wound in blunt or non penetrating trauma there may be an impact but the skin is not necessarily broken the penetrating object may remain in the tissues come back out the way it entered or pass through the tissues and exit from another area an injury in which an object enters the body or a structure and passes all the way through is called a perforating injury while penetrating trauma implies that the object does not pass through perforating trauma is associated with an entrance wound and an often larger exit wound penetrating trauma can be caused by a foreign object or by fragments of a broken bone usually occurring in violent crime or armed combat penetrating injuries are commonly caused by gunshots and stabbings penetrating trauma can be serious because it can damage internal organs and presents a risk of shock and infection the severity of the injury varies widely depending on the body parts involved the characteristics of the penetrating object and the amount of energy transmitted to the tissues assessment may involve x rays or ct scans and treatment may involve surgery for example to repair damaged structures or to remove foreign objects puncture and penetration are similar however a puncture is different from a penetration wound in that there is no exit wound in cases of puncture this type of trauma can be seen for example in a stabbing or a gunshot wound in which a low velocity pistol bullet was used
penicilliosis or penicillosis is an infection caused by penicillium marneffei it is a dimorphic fungus
penicillium expansum is one of the most prevalent post harvest rots that infects apples although it is a major economical problem in apples this plant pathogen can be isolated from a wide host range including pears strawberries tomatoes corn and rice this mold also produces the carcinogenic metabolite patulin a neurotoxin that is harmful in apple juice and apple products patulin is produced by the fungi when it rots the host the levels of patulin in food products is a health concern because many are consumed by young children in addition a second secondary metabolite citrinin is produced as well furthermore it is also one of the oldest known species of penicillium recorded and has been used for continuous research and studies it is a psychrophilic blue mold and ubiquitous throughout the soil
penile agenesis is a birth defect in humans occurring about once in 5 – 6 million male births in which a male child is born without a penis a partner condition is testicular or gonadal agenesis this is when a male child is born without gonads and consequently develops no testes penile agenesis occurs often as a consequence of testicular agenesis but the reverse is never the case most patients in both cases have no known family history and usually have an otherwise normal male anatomy
penile cancer is a malignant growth found on the skin or in the tissues of the penis around 95 of penile cancers are squamous cell carcinomas other types of penile cancer such as merkel cell carcinoma small cell carcinoma melanoma and other are generally rare
penile fracture is rupture of one or both of the tunica albuginea the fibrous coverings that envelop the penis s corpora cavernosa it is caused by rapid blunt force to an erect penis usually during vaginal or anal intercourse or aggressive masturbation it sometimes also involves partial or complete rupture of the urethra or injury to the dorsal nerves veins and arteries
a penile injury is medical emergency that afflicts the human penis common injuries include fracture avulsion strangulation entrapment and amputation
the penn effect is the economic finding that real income ratios between high and low income countries are systematically exaggerated by gross domestic product gdp conversion at market exchange rates it is associated with what became the penn world table and it has been a consistent econometric result since at least the 1950 s the balassa – samuelson effect is a model cited as the principal cause of the penn effect by neo classical economics as well as being a synonym of penn effect
the pensions crisis is a predicted difficulty in paying for corporate state and federal pensions in the united states and europe due to a difference between pension obligations and the resources set aside to fund them shifting demographics are causing a lower ratio of workers per retiree contributing factors include retirees living longer increasing the relative number of retirees and lower birth rates decreasing the relative number of workers especially relative to the post ww 2 baby boom there is significant debate regarding the magnitude and importance of the problem as well as the solutions for example as of 2008 the estimates for the underfunding of the united states state pension programs range from 1 trillion using the discount rate of 8 to 3 23 trillion using u s treasury bond yields as the discount rate the present value of unfunded obligations under social security as of august 2010 was approximately 5 4 trillion in other words this amount would have to be set aside today such that the principal and interest would cover the program s shortfall between tax revenues and payouts over the next 75 years some economists question the concept of funding and therefore underfunding storing funds by governments in the form of fiat currencies is the functional equivalent of storing a collection of their own ious they will be equally inflationary to newly written ones when they do come to be used reform ideas are in three primary categories a addressing the worker retiree ratio via raising the retirement age employment policy and immigration policy b reducing obligations via shifting from defined benefit to defined contribution pension types and reducing future payment amounts by for example adjusting the formula that determines the level of benefits and c increasing resources to fund pensions via increasing contribution rates and raising taxes
pentagram is a zx spectrum and msx video game released by ultimate play the game in 1986 it is the fourth in the sabreman series following on from his adventures in sabre wulf underwurlde and knight lore similarly to knight lore it uses the isometric filmation engine the game was written by either tim and chris stamper or a u s gold programming team see the main article for the reason for this confusion
pentalogy of cantrell or thoraco abdominal syndrome is a rare syndrome that causes defects involving the diaphragm abdominal wall pericardium heart and lower sternum it was characterized in 1958 a locus at xq 25 26 has been described
pentane interference or syn pentane interaction is the steric hindrance that the two terminal methyl groups experience in one of the chemical conformations of n pentane the possible conformations are combinations of anti conformations and gauche conformations and are anti anti anti gauche gauche gauche and gauche gauche − of which the last one is especially energetically unfavorable in macromolecules such as polyethylene pentane interference occurs between every fifth carbon atom this is not to be confused with the 1 3 diaxial interactions of cyclohexane derivatives gauche interactions shared between substituents and the ring a clear example of the syn pentane interaction is apparent in the diaxial versus diequatorial heats of formation of cis 1 3 dialkyl cyclohexanes relative to the diequatorial conformer the diaxial conformer is 2 3 kcal mol higher in energy than the value that would be expected based on 1 3 diaxial interactions alone pentane interference helps explain molecular geometries in many chemical compounds product ratios and purported transition states one specific type of syn pentane interaction is known as 1 3 allylic strain or a 1 3 strain for instance in certain aldol adducts with 2 6 disubstituted aryl groups the molecular geometry has the vicinal hydrogen atoms in an antiperiplanar configuration both in a crystal lattice x ray diffraction and in solution proton nmr coupling constants normally reserved for the most bulky groups i d both arenes syn pentane effect in aldol adducts the other contributing factor explaining this conformation is reduction in allylic strain by minimizing the dihedral angle between the arene double bond and the methine proton
a pentimento plural pentimenti is an alteration in a painting evidenced by traces of previous work showing that the artist has changed his or her mind as to the composition during the process of painting the word is italian for repentance from the verb pentirsi meaning to repent
pentosuria is a condition where the sugar xylitol a pentose presents in the urine in unusually high concentrations it was characterized as an inborn error of carbohydrate metabolism in 1908 it is associated with a deficiency of l xylulose reductase necessary for xylitol metabolism l xylulose is a reducing sugar so it may give false diagnosis of diabetes as it is found in high concentrations in urine however people with pentosuria do not have nonstandard metabolism of glucose like diabetics patients of pentosuria have a low concentration of the sugar d xyloketose using phenyl pentosazone crystals phloroglucin reaction and absorption spectrum pentose can be traced back as the reducing substance in urine with those that have pentosuria research has shown that pentosuria appears in 3 forms the most widely studied is essential pentosuria where a couple of grams of l xylusol are released into a person ’ s system daily xylulose contained in red blood cells is composed of both a major and minor isozyme for those diagnosed with essential pentosuria the major isozyme appears to be the same as the minor one alimentary pentosuria can be acquired through fruits high in pentose finally drug induced pentosuria can be developed by those exposed to morphine fevers allergies and some hormones those diagnosed with pentosuria are predominantly of jewish root however it is a harmless defect and no cure is needed
penultimate hop popping php is a function performed by certain routers in an mpls enabled network it refers to the process whereby the outermost label of an mpls tagged packet is removed by a label switch router lsr before the packet is passed to an adjacent label edge router ler the process is important in a layer 3 mpls vpn rfc 2547 environment as it reduces the load on the ler if this process didn t happen the ler would have to perform at least 2 label lookups 1 the outer label identifying that the packet was destined to have its label stripped on this router 2 the inner label to identify which virtual routing and forwarding vrf instance to use for the subsequent ip routing lookup in a large network this can result in the cpu load on the ler reaching unacceptable levels by having php for an ler done on the lsrs connected to it the load is effectively distributed among its neighbour routers php functionality is achieved by the ler advertising a label with a value of 3 to its neighbours this label is defined as implicit null and informs the neighbouring lsr s to perform php
peptic ulcer disease pud also known as a peptic ulcer or stomach ulcer is a break in the lining of the stomach first part of the small intestine or occasionally the lower esophagus an ulcer in the stomach is known as a gastric ulcer while that in the first part of the intestines is known as a duodenal ulcer the most common symptoms are waking at night with upper abdominal pain or upper abdominal pain that improves with eating the pain is often described as a burning or dull ache other symptoms include belching vomiting weight loss or poor appetite about a third of older people have no symptoms complications may include bleeding perforation and blockage of the stomach bleeding occurs in as many as 15 of people common causes include the bacteria helicobacter pylori and non steroidal anti inflammatory drugs nsaids other less common causes include tobacco smoking stress due to serious illness behcet disease zollinger ellison syndrome crohn disease and liver cirrhosis among others older people are more sensitive to the ulcer causing effects of nsaids the diagnosis is typically suspected due to the presenting symptoms with confirmation by either endoscopy or barium swallow h pylori can be diagnosed by testing the blood for antibodies a urea breath test testing the stool for signs of the bacteria or a biopsy of the stomach other conditions that produce similar symptoms include stomach cancer coronary heart disease and inflammation of the stomach lining or gallbladder diet does not play an important role in either causing or preventing ulcers treatment includes stopping smoking stopping nsaids stopping alcohol and medications to decrease stomach acid the medication used to decrease acid is usually either a proton pump inhibitor ppi or an h 2 blocker with four weeks of treatment initially recommended ulcers due to h pylori are treated with a combination of medications such as amoxicillin clarithromycin and a ppi antibiotic resistance is increasing and thus treatment may not always be effective bleeding ulcers may be treated by endoscopy with open surgery typically only used in cases in which it is not successful peptic ulcers are present in around 4 of the population they newly began in around 53 million people in 2013 about 10 of people develop a peptic ulcer at some point in their life they resulted in 301 000 deaths in 2013 down from 327 000 deaths in 1990 the first description of a perforated peptic ulcer was in 1670 in princess henrietta of england h pylori was first identified as causing peptic ulcers by barry marshall and robin warren in the late 20 th century a discovery for which they received the nobel prize in 2005
in bio informatics a peptide mass fingerprint or peptide mass map is a mass spectrum of a mixture of peptides that comes from a digested protein being analyzed the mass spectrum serves as a fingerprint in the sense that it is a pattern that can serve to identify the protein the method for forming a peptide mass fingerprint developed in 1993 consists of isolating a protein breaking it down into individual peptides and determining the masses of the peptides through some form of mass spectrometry once formed a peptide mass fingerprint can be used to search in databases for related protein or even genomic sequences making it a powerful tool for annotation of protein coding genes one major advantage to mass fingerprinting is that it is significantly faster to carry out than peptide sequencing yet the results are equally useful disadvantages include the need for a single protein for analysis and the requirement that the protein sequence is located at least with significant homology in a database because the mass of individual peptides is measured in forming a fingerprint mixtures of different proteins can yield unreliable results therefore sample preparation is an important step in the process even then if reliable results are obtained there must be a matching peptide sequence in the database you are searching in order for the results to be useful
perceptual psychology is a subfield of cognitive psychology that is concerned specifically with the pre conscious innate aspects of the human cognitive system perception perceptual psychology is a branch of cognitive psychology dealing with mental processes that we use in everyday living any time you problem solve make a decision or make a memory you are using an example of perceptual psychology perceptual psychology is often used in therapy to help a patient better their problem solving skills a pioneer of this field was james j gibson a major study was that of cognitive biases mostly due to affordances i e the perceived utility of objects in or features of one s surroundings according to gibson such features or objects were perceived as affordances and not as separate or distinct objects in themselves this view was central to several other fields as software user interface and usability engineering environmentalism in psychology and ultimately to political economy where the perceptual view was used to explain the omission of key inputs or consequences of economic transactions i e resources and wastes gerard egan and robert bolton explored areas of interpersonal interactions based on the premise that people act in accordance with their perception of a given situation while behaviour is obvious a person s thoughts and feelings are masked this gives rise to the idea that the most common problems between people are based on the assumption that we can guess what the other person is feeling and thinking they also offered methods within this scope for effective communications this includes reflective listening assertion skills conflict resolution etc
perceptual transparency is the phenomenon of seeing one surface behind another in our everyday life we often experience the view of objects through transparent surfaces physically transparent surfaces allow the transmission of a certain amount of light raysthrough them sometimes nearly the totality of rays is transmitted across the surface withoutsignificant changes of direction or chromaticity as in the case of air sometimes only light ata certain wavelength is transmitted as for coloured glass perceptually the problem of transparency is much more challenging both the light rayscoming from the transparent surface and those coming from the object behind it do reach thesame retinal location triggering a single sensorial process the system somehow maps thisinformation onto a perceptual representation of two different objects physical transparency was shown to be neither a sufficient nor a necessary condition forperceptual transparency fuchs 1923 showed that when a small portion of a transparent surface is observed neither the surface colour nor the fusion colour is perceived but only the colour resulting from the fusion of that of the transparent surface and that of the background tudor hart 1928 showed it is not possible to perceive transparency in a totallyhomogeneous field metzger 1975 showed that patterns of opaque paper can induce theillusion of transparency in the absence of physical transparency in order to distinguishperceptual from physical transparency the former has often been addressed as transparencyillusion paradoxically however two models developed within a physical context have longdominated the research in the field of perceptual transparency the episcotister model bymetelli 1970 1974 and the filter model by beck et al 1984
in botany perennation is the ability of organisms particularly plants to survive from one germinating season to another especially under unfavourable conditions such as drought or winter it typically involves development of a perennating organ which stores enough nutrients to sustain the organism during the unfavourable season and develops into one or more new plants the following year common forms of perennating organs are storage organs e g tubers and rhizomes and buds perennation is closely related with vegetative reproduction as the organisms commonly use the same organs for both survival and reproduction
perennial ryegrass staggers is poisoning by peramine lolitrem b and other toxins that are contained in perennial ryegrass lolium perenne and produced by the endophyte fungus neotyphodium lolii which can be present in all parts of the grass plant but tends to be concentrated in the lower part of the leaf sheaths the flower stalks and seeds this condition can affect horses cattle sheep farmed deer and llamas it regularly occurs in new zealand and is known spasmodically from australia north and south america and europe
perennibranchiate in zoology is the condition of an organism retaining branchae or gills through life this condition is generally said of certain amphibia such as the mudpuppy the term is opposed to caducibranchiate in some cases only a small proportion of a given amphibian population is perennibranchiate but in other instances a preponderance of the individuals have an adult gill retention for example in the case of the rough skinned newt in the cascade mountains populations approximately ninety percent of the adult population is perennibranchiate
in computer science a perfect hash function for a set s is a hash function that maps distinct elements in s to a set of integers with no collisions in mathematical terms it is a total injective function perfect hash functions may be used to implement a lookup table with constant worst case access time a perfect hash function has many of the same applications as other hash functions but with the advantage that no collision resolution has to be implemented
perfectionism in psychology is a personality trait characterized by a person s striving for flawlessness and setting excessively high performance standards accompanied by overly critical self evaluations and concerns regarding others evaluations it is best conceptualized as a multidimensional characteristic as psychologists agree that there are many positive and negative aspects in its maladaptive form perfectionism drives people to attempt to achieve an unattainable ideal and their adaptive perfectionism can sometimes motivate them to reach their goals in the end they derive pleasure from doing so when perfectionists do not reach their goals they often fall into depression
a perforated eardrum or punctured eardrum is a rupture or perforation hole of the eardrum which can occur as a result of otitis media ear infection trauma e g by trying to clean the ear with sharp instruments explosion loud noise or surgery accidental creation of a rupture flying with a severe cold can also cause perforation due to changes in air pressure and blocked eustachian tubes resulting from the cold this is especially true on landing perforation of the eardrum leads to conductive hearing loss which is usually temporary other symptoms may include tinnitus earache or a discharge of mucus
a perforated ulcer is a condition where an untreated ulcer can burn through the wall of the stomach or other areas of the gastrointestinal tract allowing digestive juices and food to leach into the abdominal cavity treatment generally requires immediate surgery the ulcer is known initially as a peptic ulcer before the ulcer burns through the full thickness of the stomach or duodenal wall a diagnosis is made by taking an erect abdominal chest x ray seeking air under the diaphragm this is in fact one of the very few occasions in modern times where surgery is undertaken to treat an ulcer many of the perforated ulcers have been attributed to the bacterium helicobacter pylori the incidence of perforated ulcer is steadily declining though there are still incidents where it occurs causes include smoking and non steroidal anti inflammatory drugs nsaids a perforated ulcer can be grouped into a stercoral perforation which involves a number of different things that causes perforation of the intestine wall
perforating calcific elastosis also known as localized acquired cutaneous pseudoxanthoma elasticum perforating periumbilical calcific elastosis and periumbilical perforating pseudoxanthoma elasticum is an acquired localized cutaneous disorder most frequently found in obese multiparous middle aged women characterized by lax well circumscribed reticulated or cobble stoned plaques occurring in the periumbilical region with keratotic surface papules
perforating folliculitis is a skin condition in humans characterized by discrete follicular keratotic eruptions involving mainly the hairy parts of the extremities
perforating granuloma annulare is a skin condition of unknown cause usually appearing on the dorsal hands presenting as papules with a central keratotic core
perfume intolerance is a condition wherein people exhibit sensitivity or allergic reactions to ingredients in perfume the most common allergic reactions to perfume or fragrances added to products is contact dermatitis though other symptoms may occur including allergic conjunctivitis the diagnosis of the causal allergen is made by patch testing with a mixture of fragrance ingredients the fragrance mix this gives a positive patch test reaction in about 10 of tested patients with eczema and the most recent estimates show that 1 7 – 4 1 of the general population are sensitized to ingredients of the fragrance mix two studies show that inhalant like allergies and sensitivity intolerances are experienced by a subset of the us population in the form of asthma and chemical sensitivities results aggregated from both surveys found that 30 5 of the general population reported scented products on others irritating 19 reported adverse health effects from air fresheners and 10 9 reported irritation by scented laundry products vented outside household products such as soaps and detergents perfume products cosmetics and other consumer goods are estimated to use 2 500 different fragrance ingredients of those approximately 100 different substances are known to elicit responses in at least some individuals an estimated 1 7 – 4 1 of the general population shows a contact allergic response to a mix of common perfume ingredients the diagnosis is made by patch testing with a mixture of fragrance ingredients the fragrance mix this gives a positive patch test reaction in about 10 of tested patients with eczema and the most recent estimates show that 1 7 – 4 1 of the general population are sensitized to ingredients of the fragrance mix although products can be labeled fragrance free many still contain lesser known fragrance chemicals that consumers may not recognize cinnamaldehyde cinnamic aldehyde is a common fragrance allergen
periampullary cancer is a cancer that forms near the ampulla of vater an enlargement of the ducts from the liver and pancreas where they join and enter the small intestine it consists of 1 ampullary tumour from ampulla of vater 2 cancer of lower common bile duct and 3 duodenal cancer adjacent to ampulla 4 carcinoma head of pancreas it presents with painless jaundice which may have waxing and waning nature because at times the sloughing of the tumor tissue relieves the obstruction partially
perianal cellulitis also known as perineal dermatitis and streptococcal perianal disease is a cutaneous condition that presents as sharply demarcated bright perianal erythema extending 2 – 3 cm around the anal verge
a perianal gland tumor is a type of tumor found near the anus in dogs that arises from specialized glandular tissue found in the perineum perianal glands do not exist in cats it is also known as a hepatoid tumor because of the similarity in cell shape to hepatocytes liver cells it is most commonly seen in intact not neutered dogs and is the third most common tumor type in intact male dogs there are two types of perianal gland tumors perianal gland adenomas which are benign and perianal gland adenocarcinomas which are malignant both have receptors for testosterone perianal gland adenomas are three times more likely to be found in intact male dogs than females and perianal gland adenocarcinomas are ten times more common in male dogs than females the most commonly affected breeds for adenomas are the siberian husky cocker spaniel pekingese and samoyed for adenocarcinomas the most commonly affected breeds are the siberian husky bulldog and alaskan malamute perianal gland tumors are located most commonly in the skin around the anus but can also be found on the tail or groin adenomas are more common making up 91 percent of perianal gland tumors in one study adenomas and adenocarcinomas look alike both being round pink and usually less than three centimeters in width adenocarcinomas are more likely to be multiple and invasive into the underlying tissue and they can metastasize to the lymph nodes liver and lungs both types should be removed and sent to a pathologist for identification however 95 percent of perianal gland adenomas will disappear after neutering the dog removing the tumor and neutering the dog at the same time will help prevent recurrence dogs with perianal gland adenocarcinomas should be treated with aggressive surgery and the radiation therapy and chemotherapy if necessary
perianal hematoma perianal thrombosis anal vein thrombosis or external hemorroidal thrombosis is a type of hematoma located in or on the border of the anus it is sometimes inappropriately referred to as an external hemorrhoid
the periapical cyst also termed radicular cyst and to a lesser extent dental cyst is the most common cyst of the jaw it is caused by pulpal necrosis secondary to dental caries or trauma the cyst lining is derived from the cell rests of malassez usually the periapical cyst is asymptomatic but a secondary infection can cause pain on radiographs it appears a radiolucency dark area around the apex of a tooth s root radicular cyst is the most common odontogenic cystic lesion of inflammatory origin it is also known as periapical cyst apical periodontal cyst root end cyst or dental cyst it arises from epithelial residues in periodontal ligament as a result of inflammation the inflammation usually follows death of dental pulp radicular cysts are found at root apices of involved teeth these cysts may persists even after extraction of offending tooth such cysts are called residual cysts
periapical periodontitis also termed apical periodontitis ap or periradicular peridontitis is an acute or chronic inflammatory lesion around the apex of a tooth root which is caused by bacterial invasion of the pulp of the tooth the term is derived from peri meaning around apical referring to the apex of the root the tip of the root and itis meaning a disease characterized by inflammation periapical periodontitis can be considered a sequela in the natural history of dental caries tooth decay irreversible pulpitis and pulpal necrosis since it is the likely outcome of untreated dental caries although not always periapical periodontitis may develop into a periapical abscess where a collection of pus forms at the end of the root the consequence of spread of infection from the tooth pulp odontogenic infection or into a periapical cyst where an epithelial lined fluid filled structure forms
pericardial effusion fluid around the heart is an abnormal accumulation of fluid in the pericardial cavity because of the limited amount of space in the pericardial cavity fluid accumulation leads to an increased intrapericardial pressure which can negatively affect heart function a pericardial effusion with enough pressure to adversely affect heart function is called cardiac tamponade pericardial effusion usually results from a disturbed equilibrium between the production and re absorption of pericardial fluid or from a structural abnormality that allows fluid to enter the pericardial cavity normal levels of pericardial fluid are from 15 to 50 ml
pericarditis is inflammation of the pericardium the fibrous sac surrounding the heart symptoms typically include sudden onset of sharp chest pain the pain may also be felt in the shoulders neck or back it is typically better sitting up and worse with lying down or breathing deep other symptoms may include fever weakness palpitations and shortness of breath occasionally onset of symptoms is gradual the cause of pericarditis is believed to be most often due to a viral infection other causes include bacterial infections such as tuberculosis uremic pericarditis following a heart attack cancer autoimmune disorders and chest trauma the cause often remains unknown diagnosis is based on the chest pain a pericardial rub specific electrocardiogram ecg changes and fluid around the heart other conditions that may produce similar symptoms include a heart attack treatment in most cases is with nsaids and possibly colchicine steroids may be used if those are not appropriate typically symptoms improve in a few days to weeks but can occasionally last months complications can include cardiac tamponade myocarditis and constrictive pericarditis it is a less common cause of chest pain about 3 per 10 000 people are affected per year those most commonly affected are males between the ages of 20 and 50 up to 30 of those affected have more than one episode
perichondritis is inflammation of the perichondrium a layer of connective tissue which surrounds cartilage a common form auricular perichondritis perichondritis auriculae involves infection of the pinna due to infection of traumatic or surgical wound or the spread of inflammation into depth it may lead to severe deformation of the pinna if not treated vigorously with iv antibiotics the causative organism is usually pseudomonas aeruginosa a rare form is laryngeal perichondritis perichondritis laryngis it develops suddenly due to an injury virulent organisms or compromised immune status of the host and also affects cartilage of the larynx this may result in deformations and stenoses
pericoronitis from the greek peri around latin corona crown and itis inflammation also known as operculitis is inflammation of the soft tissues surrounding the crown of a partially erupted tooth including the gingiva gums and the dental follicle the soft tissue covering a partially erupted tooth is known as an operculum an area which can be difficult to access with normal oral hygiene methods the synonym operculitis technically refers to inflammation of the operculum alone pericoronitis is caused by an accumulation of bacteria and debris beneath the operculum or by mechanical trauma e g biting the operculum with the opposing tooth pericoronitis is often associated with partially erupted and impacted mandibular third molars lower wisdom teeth often occurring at the age of wisdom tooth eruption 15 24 other common causes of similar pain from the third molar region are food impaction causing periodontal pain pulpitis from dental caries tooth decay and acute myofascial pain in temporomandibular joint disorder pericoronitis is classified into chronic and acute chronic pericoronitis can present with no or only mild symptoms and long remissions between any escalations to acute pericoronitis acute pericoronitis is associated with a wide range of symptoms including severe pain swelling and fever sometimes there is an associated pericoronal abscess an accumulation of pus this infection can spread to the cheeks orbits periorbits and other parts of the face or neck and occasionally can lead to airway compromise e g ludwig s angina requiring emergency hospital treatment the treatment of pericoronitis is through pain management and by resolving the inflammation the inflammation can be resolved by flushing the debris or infection from the pericoronal tissues or by removing the associated tooth or operculum retaining the tooth requires improved oral hygiene in the area to prevent further acute pericoronitis episodes tooth removal is often indicated in cases of recurrent pericoronitis extensive decay or tooth impaction
periculum in mora latin for danger in delay is one of two conditions which must be asserted in actions aimed at obtaining a protective order or injunction to be granted the relief sought the other condition being fumus boni iuris the second condition is the c d prima facie case the burden of proof of danger in delay falls to the person who requests the injunction or order demonstrating the existence of both requirements pericolum notice and the risk of suffering serious and irreparable damage the term serious harm refers to the magnitude of the damages calculated in relation to the value of the property in dispute an injury will not be so serious in itself but only when compared to the object of contention irreparable damage is in the possibility of a remedy in the future against which the party seeking the injunction believes they will suffer only asset orientation is currently supported in that the prevailing possibility of obtaining compensation for damages is in itself sufficient to prevent the founding of irreparable harm
in general these are considered to be equilibrium processes although it is possible to push the reaction in one direction by designing a reaction by which the product is at a significantly lower energy level this is due to a unimolecular interpretation of le chatelier s principle pericyclic reactions often have related stepwise radical processes associated with them some pericyclic reactions such as the 2 2 cycloaddition are controversial because their mechanism is not definitively known to be concerted or may depend on the reactive system pericyclic reactions also often have metal catalyzed analogs although usually these are also not technically pericyclic since they proceed via metal stabilized intermediates and therefore are not concerted a large photoinduced hydrogen sigmatropic shift was utilized in a corrin synthesis performed by albert eschenmoser containing a 16 π system due to the principle of microscopic reversibility there is a parallel set of retro pericyclic reactions which perform the reverse reaction
perifollicular fibroma is a cutaneous condition a benign tumor usually skin colored most often affecting the face and upper trunk
perifollicular mucinosis is a cutaneous condition characterized by mucinosis and described in hiv infected patients
perifolliculitis is an inflammation in the skin around the hair follicles it is fairly common to get this condition for a week or so after intense pulsed light treatment
perihepatitis is inflammation of the serous or peritoneal coating of the liver perihepatitis is often caused by one of the inflammatory disorders of the female upper genital tract known collectively as pelvic inflammatory disease some patients have sharp right upper abdominal quadrant pain one of the complications of perihepatitis is fitz hugh curtis syndrome common bacterial causes for this disease are chlamydia trachomatis and neisseria gonorrhoeae
perinatal asphyxia neonatal asphyxia or birth asphyxia is the medical condition resulting from deprivation of oxygen to a newborn infant that lasts long enough during the birth process to cause physical harm usually to the brain hypoxic damage can occur to most of the infant s organs heart lungs liver gut kidneys but brain damage is of most concern and perhaps the least likely to quickly or completely heal in more pronounced cases an infant will survive but with damage to the brain manifested as either mental such as developmental delay or intellectual disability or physical such as spasticity it results most commonly from a drop in maternal blood pressure or some other substantial interference with blood flow to the infant s brain during delivery this can occur due to inadequate circulation or perfusion impaired respiratory effort or inadequate ventilation perinatal asphyxia happens in 2 to 10 per 1000 newborns that are born at term and more for those that are born prematurely who estimates that 4 million neonatal deaths occur yearly due to birth asphyxia representing 38 of deaths of children under 5 years of age an infant suffering severe perinatal asphyxia usually has poor color cyanosis perfusion responsiveness muscle tone and respiratory effort as reflected in a low 5 minute apgar score extreme degrees of asphyxia can cause cardiac arrest and death if resuscitation is successful the infant is usually transferred to a neonatal intensive care unit there has long been a scientific debate over whether newborn infants with asphyxia should be resuscitated with 100 oxygen or normal air it has been demonstrated that high concentrations of oxygen lead to generation of oxygen free radicals which have a role in reperfusion injury after asphyxia research by ola didrik saugstad and others led to new international guidelines on newborn resuscitation in 2010 recommending the use of normal air instead of 100 oxygen there is considerable controversy over the diagnosis of birth asphyxia due to medicolegal reasons because of its lack of precision the term is eschewed in modern obstetrics
perinatal gangrene of the buttock is a skin condition similar to livedoid dermatitis and is usually a complication of umbilical artery catheterization exchange transfusion or cord injections by means of a syringe
perinatal mortality pnm also perinatal death refers to the death of a fetus or neonate and is the basis to calculate the perinatal mortality rate variations in the precise definition of the perinatal mortality exist specifically concerning the issue of inclusion or exclusion of early fetal and late neonatal fatalities the world health organization defines perinatal mortality as the number of stillbirths and deaths in the first week of life per 1 000 total births the perinatal period commences at 22 completed weeks 154 days of gestation and ends seven completed days after birth but other definitions have been used the uk figure is about 8 per 1 000 and varies markedly by social class with the highest rates seen in asian women globally about 2 6 million neonates died in 2013 before the first month of age down from 4 5 million in 1990
perineal hernia is a hernia involving the perineum pelvic floor the hernia may contain fluid fat any part of the intestine the rectum or the bladder it is known to occur in humans dogs and other mammals and often appears as a sudden swelling to one side sometimes both sides of the anus a common cause of perineal hernia is surgery involving the perineum perineal hernia can be caused also by excessive straining to defecate tenesmus other causes include prostate or urinary disease constipation anal sac disease in dogs and diarrhea atrophy of the levator ani muscle and disease of the pudendal nerve may also contribute to a perineal hernia
in obstetrics a perineal tear is a spontaneous unintended laceration of the skin and other soft tissue structures which in women separate the vagina from the anus perineal tears mainly occur in women as a result of vaginal childbirth which strains the perineum tears vary widely in severity the majority are superficial and require no treatment but severe tears can cause significant bleeding long term pain or dysfunction a perineal tear is distinct from an episiotomy in which the perineum is intentionally incised to facilitate delivery
perineodynia means perineal pain and includes vulvodynia and proctalgia fugax pudendal neuralgia is one of the main causes of perineodynia
a period of financial distress occurs when the price of a company or an asset or an index of a set of assets in a market is declining with the danger of a sudden crash of value occurring either because the company is experiencing increasing problems of cash flow or a deteriorating credit balance or because the price had become too high as a result of a speculative bubble that has now peaked
periodic fever aphthous stomatitis pharyngitis and adenitis or periodic fever aphthous pharyngitis and cervical adenopathy pfapa syndrome is a medical condition typically starting in young children in which high fever occurs periodically at intervals of about 3 – 5 weeks frequently accompanied by aphthous like ulcers pharyngitis and or cervical adenitis cervical lymphadenopathy the syndrome was described in 1987 and named two years later
periodic fever syndromes also known as autoinflammatory diseases or autoinflammatory syndromes are a set of disorders characterized by recurrent episodes of systemic and organ specific inflammation unlike autoimmune disorders such as systemic lupus erythematosus in which the disease is caused by abnormalities of the adaptive immune system patients with autoinflammatory diseases do not produce autoantibodies or antigen specific t or b cells instead the autoinflammatory diseases are characterized by errors in the innate immune system the syndromes are diverse but tend to cause episodes of fever joint pains skin rashes abdominal pains and may lead to chronic complications such as amyloidosis most autoinflammatory diseases are genetic and present during childhood the most common genetic autoinflammatory syndrome is familial mediterranean fever which causes short episodes of fever abdominal pain serositis lasting less than 72 hours it is caused by mutations in the mefv gene which codes for the protein pyrin pyrin is a protein normally present in the inflammasome the mutated pyrin protein is thought to cause inappropriate activation of the inflammasome leading to release of the pro inflammatory cytokine il 1 β most other autoinflammatory diseases also cause disease by inappropriate release of il 1 β thus il 1 β has become a common therapeutic target and medications such as anakinra rilonacept and canakinumab have revolutionized the treatment of autoinflammatory diseases however there are some autoinflammatory diseases that are not known to have a clear genetic cause this includes pfapa which is the most common autoinflammatory disease seen in children characterized by episodes of fever aphthous stomatitis pharyngitis and cervical adenitis other autoinflammatory diseases that do not have clear genetic causes include adult onset still s disease systemic onset juvenile idiopathic arthritis schnitzler syndrome and chronic recurrent multifocal osteomyelitis it is likely that these diseases are multifactorial with genes that make people susceptible to these diseases but they require an additional environmental factor to trigger the disease an other example that shows that autoinflamatory conditions may not be genetic in origin is found in a report published in nature which shows that diet is very important in the development of such diseases the ingestion levels of highly saturated fats and cholesterol high fat diet hfd affects the microbiota composition of the gut changes in the microbiota induced by a hfd are protective against the susceptibility to develop osteomyelitis autoimmune disease as compared with the changes induced by a low fat diet the changes in the microbiome of individuals under hfd showed a reduction in prevotella abundance and were accompanied by significantly reduced expression levels of pro interleukin 1 β in distant neutrophils
periodic limb movement disorder plmd previously known as nocturnal myoclonus is a sleep disorder where the patient moves limbs involuntarily during sleep and has symptoms or problems related to the movement plmd should not be confused with restless legs syndrome rls rls occurs while awake as well as when asleep and when awake there is a voluntary response to an uncomfortable feeling in the legs plmd on the other hand is involuntary and the patient is often unaware of these movements altogether
periodic paralysis also known as myoplegia paroxysmalis familiaris is a group of rare genetic diseases that lead to weakness or paralysis rarely death from common triggers such as cold heat high carbohydrate meals not eating stress or excitement and physical activity of any kind the underlying mechanism of these diseases are malfunctions in the ion channels in skeletal muscle cell membranes that allow electrically charged ions to leak in or out of the muscle cell causing the cell to depolarize and become unable to move a channelopathy the symptoms of periodic paralysis can also be caused by hyperthyroidism and are then labeled thyrotoxic periodic paralysis however if this is the underlying condition there are likely to be other characteristic manifestations enabling a correct diagnosis
in mathematics a periodic travelling wave or wavetrain is a periodic function of one dimensional space that moves with constant speed consequently it is a special type of spatiotemporaloscillation that is a periodic function of both space and time periodic travelling waves play a fundamental role in many mathematicalequations including self oscillatory systems excitable systems andreaction diffusion advection systems equations of these types are widely used as mathematical models of biology chemistry and physics and many examples in phenomena resembling periodic travelling waves havebeen found empirically the mathematical theory of periodic travelling waves is most fullydeveloped for partial differential equations but these solutionsalso occur in a number of other types of mathematical system including integrodifferential equations integrodifference equations coupled map latticesandcellular automata as well as being important in their own right periodic travellingwaves are significant as the one dimensional equivalent of spiral waves and target patterns in two dimensional space and of scroll waves in three dimensional space
a periodontal abscess also termed lateral abscess or parietal abscess is a localized collection of pus i e an abscess within the tissues of the periodontium it is a type of dental abscess a periodontal abscess occurs alongside a tooth and is different from the more common periapical abscess which represents the spread of infection from a dead tooth i e which has undergone pulpal necrosis to reflect this sometimes the term lateral periodontal abscess is used in contrast to a periapical abscess periodontal abscesses are usually associated with a vital living tooth abscesses of the periodontium are acute bacterial infections classified primarily by location
periodontitis also known as pyorrhea is a set of inflammatory diseases affecting the periodontium i e the tissues that surround and support the teeth periodontitis involves progressive loss of the alveolar bone around the teeth and if left untreated can lead to the loosening and subsequent loss of teeth periodontitis is caused by microorganisms that adhere to and grow on the tooth s surfaces along with an over aggressive immune response against these microorganisms a diagnosis of periodontitis is established by inspecting the soft gum tissues around the teeth with a probe i e a clinical examination and by evaluating the patient s x ray films i e a radiographic examination to determine the amount of bone loss around the teeth specialists in the treatment of periodontitis are periodontists their field is known as periodontology or periodontics
perioral dermatitis also called periorifical dermatitis is skin disease characterised by multiple small 1 – 2 mm papules pustules and vesicles which are localized to the perioral skin around the mouth perinasal or nasolabial folds around the nostrils or perioccular area around the eyes it most commonly affects women between the ages of 20 and 45 years but may also affect children men and the elderly it is not uncommon and has a tendency to recur in individuals who have had it once
periorbital cellulitis also known as preseptal cellulitis and not to be confused with orbital cellulitis which is behind the septum is an inflammation and infection of the eyelid and portions of skin around the eye anterior to the orbital septum it may be caused by breaks in the skin around the eye and subsequent spread to the eyelid infection of the sinuses around the nose sinusitis or from spread of an infection elsewhere through the blood
periorbital dermatitis also known as periocular dermatitis is a skin condition a variant of perioral dermatitis occurring on the lower eyelids and skin adjacent to the upper and lower eyelids
periorbital hyperpigmentation is characterized by dark circles around the eyes which are common often familial and frequently found in individuals with dark pigmentation or mediterranean ancestry atopic patients may also exhibit periorbital pigmentation allergic shiners due to lower eyelid venous stasis and treatment is ineffective
periorbital puffiness also known as puffy eyes or swelling around the eyes is the appearance of swelling in the tissues around the eyes called the orbits it is almost exclusively caused by fluid buildup around the eyes or periorbital edema minor puffiness usually detectable below the eyes only although at times they could be present all around is often called eye bags such transient puffiness is distinct from the age related and gradual increase in the size of the fat pad lying below the lower eyelids suborbicularis oculi fat soof which can also be colloquially referred to as eye bags
periorificial dermatitis is a cutaneous condition characterized by a combination of perioral dermatitis and periocular dermatitis
a periosteal reaction is the formation of new bone in response to injury or other stimuli of the periosteum surrounding the bone it is most often identified on x ray films of the bones
periostitis also known as periostalgia is a medical condition caused by inflammation of the periosteum a layer of connective tissue that surrounds bone the condition is generally chronic and is marked by tenderness and swelling of the bone and an aching pain
peripartum cardiomyopathy ppcm is a form of dilated cardiomyopathy that is defined as a deterioration in cardiac function presenting typically between the last month of pregnancy and up to six months postpartum as with other forms of dilated cardiomyopathy ppcm involves systolic dysfunction of the heart with a decrease of the left ventricular ejection fraction ef with associated congestive heart failure and an increased risk of atrial and ventricular arrhythmias thromboembolism blockage of a blood vessel by a blood clot and even sudden cardiac death in essence the heart muscle cannot contract forcefully enough to pump adequate amounts of blood for the needs of the body s vital organs ppcm is a diagnosis of exclusion wherein patients have no prior history of heart disease and there are no other known possible causes of heart failure echocardiogram is used to both diagnose and monitor the effectiveness of treatment for ppcm the cause of ppcm is unknown currently researchers are investigating cardiotropic viruses autoimmunity or immune system dysfunction other toxins that serve as triggers to immune system dysfunction micronutrient or trace mineral definciencies and genetics as possible components that contribute to or cause the development of ppcm the process of ppcm begins with an unknown trigger possibly a cardiotropic virus or other yet unidentified catalyst that initiates an inflammatory process in the heart consequently heart muscle cells are damaged some die or become scar tissue scar tissue has no ability to contract therefore the effectiveness of the pumping action of the heart is decreased also damage to the cytoskeletal framework of the heart causes the heart to enlarge stretch or alter in shape also decreasing the heart s systolic function or output the initial inflammatory process appears to cause an autoimmune or immune dysfunctional process which in turn fuels the initial inflammatory process progressive loss of heart muscle cells leads to eventual heart failure
peripheral t cell lymphoma refers to a group of t cell lymphomas that develop away from the thymus examples include cutaneous t cell lymphomas angioimmunoblastic t cell lymphoma extranodal natural killer t cell lymphoma nasal type enteropathy type t cell lymphoma subcutaneous panniculitis like t cell lymphoma anaplastic large cell lymphoma peripheral t cell lymphoma not otherwise specified in icd 10 cutaneous t cell lymphomas are classified separately
peripheral t cell lymphoma not otherwise specified ptcl nos is a subtype of peripheral t cell lymphoma peripheral t cell lymphoma ptcl is defined as a diverse group of aggressive lymphomas that develop from mature stage white blood cells called t cells and natural killer cells nk cells see figure for an overview of ptcl subtypes ptcl is a type of non hodgkin ’ s lymphoma nhl nhl affects two particular types of white blood cells b cells and t cells ptcl specifically affects t cells and results when t cells develop and grow abnormally file ptcl subtypes jpg ptcl nos the most common subtype of ptcl is aggressive and predominantly nodal there are two morphologic variants the t zone lymphoma variant and the lymphoepithelioid cell variant t zone lymphoma is so named for its involvement in a specific area of the lymph node that consists of a dense accumulation of t cells lympho epithelioid lymphoma also called lennert s lymphoma is rare and generally affects older individuals
peripheral artery disease pad is a narrowing of the arteries other than those that supply the heart or the brain when narrowing occurs in the heart it is called coronary artery disease while in the brain it is called cerebrovascular disease peripheral artery disease most commonly affects the legs but other arteries may also be involved the classic symptom is leg pain when walking which resolves with rest known as intermittent claudication other symptoms including skin ulcers bluish skin cold skin or poor nail and hair growth may occur in the affected leg complications may include an infection or tissue death which may require amputation coronary artery disease or stroke up to 50 of cases of pad are without symptoms the main risk factor is cigarette smoking other risk factors include diabetes high blood pressure and high blood cholesterol the underlying mechanism is usually atherosclerosis other causes include artery spasm pad is typically diagnosed by finding an ankle brachial index abi less than 0 90 which is the systolic blood pressure at the ankle divided by the systolic blood pressure of the arm duplex ultrasonography and angiography may also be used angiography is more accurate and allows for treatment at the same time however it is associated with greater risks it is unclear if screening for disease is useful as it has not been properly studied in those with intermittent claudication from pad stopping smoking and supervised exercise therapy improves outcomes medications including statins ace inhibitors and cilostazol also may help aspirin does not appear to help those with mild disease but is usually recommended in those with more significant disease anticoagulants such as warfarin are not typically of benefit procedures used to treat the disease include bypass grafting angioplasty and atherectomy in 2010 about 202 million people had pad worldwide in the developed world it affects about 5 3 of 45 to 50 years olds and 18 6 of 85 to 90 year olds in the developing world it affects 4 6 of people between the ages of 45 to 50 and 15 of people between the ages of 85 to 90 in the developed world pad is equally common among men and women while in the developing world women are more commonly affected in 2013 pad resulted in about 41 000 deaths up from 16 000 deaths in 1990
peripheral giant cell granuloma pgcg is an oral pathologic condition that appears in the mouth as an overgrowth of tissue due to irritation or trauma because of its overwhelming incidence on the gingiva the condition is associated with two other diseases though not because they occur together instead the three are associated with each other because they appear frequently on gingiva pyogenic granuloma and peripheral ossifying fibroma because of its similar microscopic appearance to the bony lesions called central giant cell granulomas peripheral giant cell granulomas are considered by some researchers to be a soft tissue equivalent the appearance of peripheral giant cell granulomas is similar to pyogenic granulomas the color ranges from red to bluish purple but is usually more blue in comparison to pyogenic granulomas it can be sessile or pedunculated with the size usually being less than 2 cm there is a gender difference with 60 of the disease occurring in females the prevalence of peripheral giant cell granulomas is highest around 50 60 years of age it appears only on the gingiva or on an edentulous without teeth alveolar ridge it is more often found in the mandible rather than the maxilla but can be found in either anterior or posterior areas the underlying alveolar bone can be destroyed leaving a unique appearance referred to as cupping resorption or saucerization
peripheral neuropathy pn is damage to or disease affecting nerves which may impair sensation movement gland or organ function or other aspects of health depending on the type of nerve affected common causes include systemic diseases such as diabetes or leprosy vitamin deficiency medication e g chemotherapy traumatic injury radiation therapy excessive alcohol consumption immune system disease coeliac disease or viral infection it can also be genetic present from birth or idiopathic no known cause in conventional medical usage the word neuropathy neuro nervous system and pathy disease of without modifier usually means peripheral neuropathy neuropathy affecting just one nerve is called mononeuropathy and neuropathy involving multiple nerves in roughly the same areas on both sides of the body is called symmetrical polyneuropathy or simply polyneuropathy when two or more typically just a few but sometimes many separate nerves in disparate areas of the body are affected it is called mononeuritis multiplex multifocal mononeuropathy or multiple mononeuropathy peripheral neuropathy may be chronic a long term condition where symptoms begin subtly and progress slowly or acute sudden onset rapid progress and slow resolution acute neuropathies demand urgent diagnosis motor nerves that control muscles sensory nerves or autonomic nerves that control automatic functions such as heart rate body temperature and breathing may be affected more than one type of nerve may be affected at the same time peripheral neuropathies may be classified according to the type of nerve predominantly involved or by the underlying cause neuropathy may cause painful cramps fasciculations fine muscle twitching muscle loss bone degeneration and changes in the skin hair and nails additionally motor neuropathy may cause impaired balance and coordination or most commonly muscle weakness sensory neuropathy may cause numbness to touch and vibration reduced position sense causing poorer coordination and balance reduced sensitivity to temperature change and pain spontaneous tingling or burning pain or skin allodynia severe pain from normally nonpainful stimuli such as light touch and autonomic neuropathy may produce diverse symptoms depending on the affected glands and organs but common symptoms are poor bladder control abnormal blood pressure or heart rate and reduced ability to sweat normally
the peripheral odontogenic fibroma is an uncommon gingival mass it affects people across a large age range it can be confused with the peripheral ossifying fibroma in contrast to the peripheral ossifying fibroma the peripheral odontogenic fibroma is a rare lesion no specific gender predilection while the ages of the patients ranged from 5 to 65 years commonly seen in mandible than maxilla slow growing solid firmly attached gingival mass sometimes arising between teeth and sometimes displacing teeth consists of cellular fibrous connective tissue parenchyma with non neoplastic islands strands of clouman or cuboidal odontogenic epithelium
peripheral ossifying fibroma “ a gingival nodule which is composed of a cellular fibroblastic connective tissue stroma which is associated with the formation of randomly dispersed foci of mineralised products which consists of bone cementum like tissue or a dystrophic calcification the lesion is considered part of an ossifying fibroma but that is usually considered to be a gnathic tumor because of its overwhelming incidence on the gingiva the condition is associated with two other diseases though not because they occur together instead the three are associated with each other because they appear frequently on gingiva pyogenic granuloma and peripheral giant cell granuloma some researchers believe peripheral ossifying fibromas to be related to pyogenic fibromas and in some instances are the result of a pyogenic granuloma which has undergone fibrosis and calcification the term peripheral ossifying fibroma has been criticized as this lesion is not related to the ossifying fibroma of bone and is not a fibroma this term is used in america however in britain this lesion would be termed a fibrous epulis containing bone
perisylvian syndrome is a rare neurological disease characterized by damage to the sylvian fissure lateral sulcus an area in the brain involved in language and speech the main symptoms are difficulty chewing and swallowing low muscle tone in the face and tongue speech and language development disorders and epilepsy these symptoms may also be accompanied by difficulties with mobility and intellectual disabilities
peritoneal mesothelioma is the name given to the cancer that attacks the lining of the abdomen this type of cancer affects the lining that protects the contents of the abdomen and which also provides a lubricating fluid to enable the organs to move and work properly the peritoneum is made of two parts the visceral and parietal peritoneum the visceral peritoneum covers the internal organs and makes up most of the outer layer of the intestinal tract covering the abdominal cavity is the parietal peritoneum
peritonitis is an inflammation of the peritoneum the thin tissue that lines the inner wall of the abdomen and covers most of the abdominal organs peritonitis may be localized or generalized and may result from infection often due to rupture of a hollow abdominal organ as may occur in abdominal trauma or inflamed appendix or from a non infectious process
unlike tonsillitis which is more common in the pediatric age group pta has a more even age spread from children to adults symptoms start appearing two to eight days before the formation of an abscess a progressively severe sore throat on one side and pain during swallowing odynophagia usually are the earliest symptoms as the abscess develops persistent pain in the peritonsillar area fever a general sense of feeling unwell headache and a distortion of vowels informally known as hot potato voice may appear neck pain associated with tender swollen lymph nodes referred ear pain and foul breath are also common while these signs may be present in tonsillitis itself a pta should be specifically considered if there is limited ability to open the mouth trismus physical signs of a peritonsillar abscess include redness and swelling in the tonsillar area of the affected side and swelling of the jugulodigastric lymph nodes the uvula may be displaced towards the unaffected side
periungual warts are warts that cluster around the fingernail or toenail they appear as thickened fissured cauliflower like skin around the nail plate periungual warts often cause loss of the cuticle and paronychia nail biting increases susceptibility to these warts warts of this kind often cause damage to the nail either by lifting the nail from the skin or causing the nail to partially detach if they extend under the nail then the patient may suffer pain as a result sometimes periungual wart infections resemble the changes that are found in onychomycosis in worst cases if the infection causes injury or damage to the nail matrix deformity in the nail may become permanent as with other wart types a number of treatments are available including laser therapy cryotherapy salicylic acid and other topical treatments
in oncology pecoma also pec tumour and perivascular epithelioid cell tumour is a family of mesenchymal tumours consisting of perivascular epithelioid cells pecs these are rare tumours that can occur in any part of the human body the cell type from which these tumours originate remains unknown normally no perivascular epitheloid cells exist the name refers to the characteristics of the tumour when examined under the microscope establishing the malignant potential of these tumours remains challenging although criteria have been suggested some pecomas display malignant features whereas others can cautiously be labeled as having uncertain malignant potential the most common tumours in the pecoma family are renal angiomyolipoma and pulmonary lymphangioleiomyomatosis both of which are more common in patients with tuberous sclerosis complex the genes responsible for this multi system genetic disease have also been implicated in other pecomas many pecoma types shows a female predominance in the sex ratio
periventricular leukomalacia pvl is a form of white matter brain injury characterized by the necrosis more often coagulation of white matter near the lateral ventricles it can affect newborns and less commonly fetuses premature infants are at the greatest risk of the disorder affected individuals generally exhibit motor control problems or other developmental delays and they often develop cerebral palsy or epilepsy later in life this pathology of the brain was described under various names encephalodystrophy ischemic necrosis periventricular infarction coagulation necrosis leukomalacia softening of the brain infarct periventricular white matter necrosis of white matter diffuse symmetrical periventricular leukoencephalopathy and more often by german scientists but the worldwide dissemination was the term « periventricular leukomalacia » introduced in 1962 b a banker and j c larroche the term can be misleading as there is no softening of the tissue in pvl v v vlasyuk and v p tumanov in 1985 published the world s first monograph devoted to pvl vlasyuk 1981 first revealed the high incidence of optic radiation lesions and demonstrated that pvl a persistent process that the old necrosis can join a new foci of pvl may be at different stages of development in the process of morphogenesis focuses pvl pass through three stages 1 necrosis 2 resorption and 3 the formation gliosis scars or cysts cysts occur when large and confluent focuses of pvl with mixed necrosis kollikvacia in the center and coagulation rim at the periphery around the foci is generally defined area of other lesions of the brain white matter the death of prooligodendrocytes proliferation mikrogliocytes and astrocytes swelling bleeding loss of capillaries and others the so called diffuse component pvl however diffuse lesions without necrosis are not pvl
the perkin reaction is an organic reaction developed by william henry perkin that is used to make cinnamic acids it gives an α β unsaturated aromatic acid by the aldol condensation of an aromatic aldehyde and an acid anhydride in the presence of an alkali salt of the acid the alkali salt acts as a base catalyst and other bases can be used instead the perkin reaction several reviews have been written
the perkow reaction is an organic reaction in which a trialkyl phosphite ester reacts with a haloketone to form a dialkyl vinyl phosphate and an alkyl halide the perkow reaction in the related michaelis – arbuzov reaction the same reactants are known to form a beta keto phosphonate which is an important reagent in the horner – wadsworth – emmons reaction on the road to alkenes the perkow reaction in this respect is considered a side reaction
perlman syndrome ps also called renal hamartomas nephroblastomatosis and fetal gigantism is a rare overgrowth disorder present at birth it is characterized by polyhydramnios and fetal overgrowth including macrocephaly neonatal macrosomia visceromegaly dysmorphic facial features and an increased risk for wilms tumor at an early age the prognosis for perlman syndrome is poor and it is associated with a high neonatal mortality
in linear algebra the permanent of a square matrix is a function of the matrix similar to the determinant the permanent as well as the determinant is a polynomial in the entries of the matrix both permanent and determinant are special cases of a more general function of a matrix called the immanant
a permanent downhole gauge pdg is a pressure and or temperature gauge permanently installed in an oil or gas well typically they are installed in tubing in the well and can measure the tubing pressure or annulus pressure or both systems installed in well casing to read formation pressure directly suspended systems and systems built in coil continuous tubing are also available the data that pdgs provide are useful to reservoir engineers in determining the quantities of oil or gas contained below the earth s surface in an oil or gas reservoir and also which method of production is best permanent downhole gauges or permanents for short are installed in oil and gas wells for the purposes of observation and optimization the most prolific function of a permanent is to monitor pressure at a single point or multiple points in a well temperature is the second most monitored factor permanent downhole gauges continue to evolve into many different types of sensors 1 pressure 2 temperature 3 distributive temperature 4 noise 5 strain 6 flow the information provided by a permanently mounted sensor enables smart well technology a smart well is a well that can monitor information and make adjustments automatically the adjustments will optimize production or protect the well the vast majority of producing oil and gas wells in the world have no such instrumentation or capabilities pdg s are important tools for optimal production and protection of our most important non renewable resources
a newly identified and potentially treatable form of monogenic diabetes is the neonatal diabetes caused by activating mutations of the kcnj 11 gene which codes for the kir 6 2 subunit of the beta cell katp channel this disease is considered to be a type of maturity onset diabetes of the young mody it can be associated with gck kcnj 11 ins and abcc 8
permanent signal ps in us telephony jargon or permanent loop in british usage is a condition in which a pots line is off hook without connection for an extended period of time this is indicated in modern switches by the silent termination after the off hook tone times out and the telephone exchange computer puts the telephone line on its high wet list or wetlist in older switches however a permanent signal holding trunk psht would play either a howler tone or a 480 500 hz high tone which would subsequently bleed into adjacent lines via crosstalk howler tone is a tone of increasing intensity that is intended to alert telephone users to the fact that the receiver has been left off the hook without being connected in a call permanent signal can also describe the state of a trunk that is seized but has not been dialed upon if it remains in a busy condition sometimes alerting with reorder in most mid 20 th century switching equipment a permanent signal would tie up a junctor circuit diminishing the ability of the switch to handle outgoing calls when flooded cables or other conditions made this a real problem switch staff would open the cable or paper the off normal contacts of the crossbar switch or block the line relay from operating these methods had the disadvantage of blocking all outgoing calls from that line until it was manually cleared manufacturers also sold devices that monitored the talk wires and held up the cutoff relay or crossbar hold magnet until the condition cleared some crossbar line circuit designs had a park condition allowing the line circuit itself to monitor the line stored program control exchanges finally solved the problem by setting a bit mask in the scanning program and running a low priority periodic checking program against the wetlist depending on software version a wetlisted line may also be in plo or lockout state
in physics and engineering permeation also called imbuing is the penetration of a permeate such as a liquid gas or vapor through a solid it is directly related to the concentration gradient of the permeate a material s intrinsic permeability and the materials mass diffusivity permeation is modeled by equations such as fick s laws of diffusion and can be measured using tools such as a minipermeameter
in north america permissive dialing is the ability to make phone calls in an area subject to a newly introduced area code by using both the new and preexisting dialing methods when an area is given a new area code under a split plan the area s previous area code would no longer be valid for calls in the area so calls to numbers using the old area code will not work to alleviate misdialing frustration the local routing can be set up such that both the old and new area codes will work for the same telephone exchange during this period the local numbering authority must not reassign the area s existing exchanges to the remaining area of the old area code nor vice versa at the end of the permissive dialing period the old area code is no longer valid for numbers in the affected area under an overlay plan permissive dialing refers to the ability to continue to connect calls via 7 digit dialing while also making 10 digit dialing valid again the affected area must not introduce any new ambiguous telephone exchanges at the end of the period 10 digit dialing becomes mandatory
in endocrinology permissiveness is a biochemical phenomenon in which the presence of one hormone is required in order for another hormone to exert its full effects on a target cell hormones can interact in permissive synergistic or antagonistic ways the chemical classes of hormones include amines polypeptides glycoproteins and steroids permissive hormones act as precursors to active hormones and may be classified as either prohormones or prehormones
pernicious anemia also known as vitamin b 12 deficiency anemia is a disease in which there are not enough red blood cells due to a lack of vitamin b 12 the most common initial symptom is feeling tired other symptoms may include shortness of breath pale skin chest pain numbness in the hands and feet poor balance a smooth red tongue poor reflexes and confusion if treatment is not provided some of these problems may become permanent although pernicious anemia technically refers to cases resulting from not enough intrinsic factor it is often used to describe all cases of anemia due to not enough vitamin b 12 lack of intrinsic factor is most commonly due to an autoimmune attack on the cells that make it in the stomach it can also occur following the surgical removal of part of the stomach or from an inherited disorder other causes of low vitamin b 12 include a poor diet celiac disease and a tapeworm infection when suspected diagnosis is made by blood and occasionally bone marrow tests blood tests may show fewer but larger red blood cells low numbers of young red blood cells low levels of vitamin b 12 and antibodies to intrinsic factor pernicious anemia due to lack of intrinsic factor is not preventable vitamin b 12 deficiency due to other causes may be prevented with a balanced diet or with supplements pernicious anemia can be easily treated with either injections or pills of vitamin b 12 if the symptoms are severe injections are typically recommended initially for those who have trouble swallowing pills a nasal spray is available often treatment is lifelong pernicious anemia due to autoimmune problems occurs in about 1 per 1000 people among those over the age of 60 about 2 have the condition it more commonly affects people of northern european descent women are more commonly affected than men with proper treatment most people live normal lives due to a higher risk of stomach cancer those with pernicious anemia should be checked regularly for this the first clear description was by thomas addison in 1849 the term pernicious means deadly and was used as before the availability of treatment the disease was often fatal
peroxisomal disorders represent a class of medical conditions caused by defects in peroxisome functions this may be due to defects in single enzymes important for peroxisome function or in peroxins proteins encoded by pex genes that are critical for normal peroxisome assembly and biogenesis
in psychology persistence ps is a personality trait it is measured in the temperament and character inventory tci and is considered one of the four temperament traits persistence refers to perseverance in spite of fatigue or frustration cloninger s research found that persistence like the other temperament traits is highly heritable the subscales of ps in tci r consist of 1 eagerness of effort ps 1 2 work hardened ps 2 3 ambitious ps 3 4 perfectionist ps 4 a study comparing the temperament and character inventory to the five factor model of personality found that persistence was substantially associated with conscientiousness additionally persistence was moderately positively associated with the tci trait of self transcendence research has also found that persistence is positively correlated with activity in zuckerman s alternative five model and is negatively correlated with psychoticism in eysenck s model persistence can also be measured as the time invested in staying on task as an example if a cab driver works an 8 hour shift their persistence is 8 hours this isn t a relation to how hard one works as this is a reference to force if person a is a hard worker and person b is not this is a reference to effort not persistence
persistent müllerian duct syndrome pmds is the presence of müllerian duct derivatives fallopian tubes uterus and or the upper part of the vagina in a genetically male animal in humans pmds typically is due to an autosomal recessive congenital disorder and is considered by some to be a form of pseudohermaphroditism due to the presence of müllerian derivatives typical features include undescended testes cryptorchidism and the presence of a small underdeveloped uterus in an xy infant or adult this condition is usually caused by deficiency of fetal anti müllerian hormone amh effect due to mutations of the gene for amh or the anti müllerian hormone receptor but may also be as a result of insensitivity to amh of the target organ
persistent adrenarche syndrome also known as adrenal saha syndrome is a cutaneous condition seen typically in thin young women who report great psychological and physical stress in their lives
persistent migraine aura without infarction pawoi is a little known condition first described under the designation prolonged migraine aura status that is not yet fully understood pawoi is said to be a possible cause of a variety of neurological symptoms including visual snow loss of vision increased afterimages tinnitus and others however the pathogenesis of pawoi is unknown in other words it is not known exactly what causes these symptoms furthermore it is not clear which medical examinations are useful in diagnosing pawoi at present pawoi is usually diagnosed solely based on the patient s present and past symptoms it may be possible that an overactive brain or a chemical imbalance is partly to blame for the disorder different medication has been tried as treatment notably acetazolamide valproate lamotrigine topiramate and furosemide
a persistent cloaca is a symptom of a complex anorectal congenital disorder in which the rectum vagina and urinary tract meet and fuse creating a cloaca a single common channel
persistent fetal circulation is a condition caused by a failure in the systemic circulation and pulmonary circulation to convert from the antenatal circulation pattern to the normal pattern in a fetus there is high pulmonary vascular resistance and low pulmonary blood flow as the fetus does not use the lungs for oxygen transfer when the baby is born the lungs are needed for oxygen transfer and need high blood flow which is encouraged by low pulmonary vascular resistance it can be associated with pulmonary hypertension because of this the condition is also known as persistent pulmonary hypertension of the newborn
persistent fetal vasculature is a condition often confused with childhood cataract it was formerly referred to as persistent hyperplastic primary vitreous
persistent hyperplastic primary vitreous phpv also known as persistent fetal vasculature pfv is a rare congenital developmental anomaly of the eye that resultsfollowing failure of the embryological primary vitreous and hyaloid vasculature to regress it can be present in three forms purely anterior persistent tunica vasculosa lentis and persistent posterior fetal fibrovascular sheath of the lens purely posterior falciform retinal septum and ablatio falcicormis congenita and a combination of both most examples of phpv are unilateral and non hereditary when bilateral phpv may follow an autosomal recessive or autosomal dominant inheritance pattern
in anatomy a persistent left superior vena cava plsvc is the most common variation of the thoracic venous system is prevalent in 0 3 of the population and an embryologic remnant that results from a failure to involute
commonly referred as phosphorescence persistent luminescence is the phenomenon encountered in materials which make them glow in the dark after the end of an excitation with uv or visible light
persistent pupillary membrane ppm is a condition of the eye involving remnants of a fetal membrane that persist as strands of tissue crossing the pupil the pupillary membrane in mammals exists in the fetus as a source of blood supply for the lens it normally atrophies from the time of birth to the age of four to eight weeks ppm occurs when this atrophy is incomplete it generally does not cause any symptoms the strands can connect to the cornea or lens but most commonly to other parts of the iris attachment to the cornea can cause small corneal opacities while attachment to the lens can cause small cataracts using topical atropine to dilate the pupil may help break down ppms in dogs ppm is inherited in the basenji but can occur in other breeds such as the pembroke welsh corgi chow chow mastiff and english cocker spaniel it is also rarely seen in cats horses and cattle
a persistent thyroglossal duct is a usually benign medical condition in which the thyroglossal duct a structure usually only found during embryonic development fails to atrophy the duct persists as a midline structure forming an open connection between the back of the tongue and the thyroid gland this opening can lead to fluid accumulation and infection which necessitate the removal of the duct
persistent truncus arteriosus or patent truncus arteriosus or common arterial trunk is a rare form of congenital heart disease that presents at birth in this condition the embryological structure known as the truncus arteriosus fails to properly divide into the pulmonary trunk and aorta this results in one arterial trunk arising from the heart and providing mixed blood to the coronary arteries pulmonary arteries and systemic circulation
a persistent vegetative state pvs is a disorder of consciousness in which patients with severe brain damage are in a state of partial arousal rather than true awareness after four weeks in a vegetative state vs the patient is classified as in a persistent vegetative state this diagnosis is classified as a permanent vegetative state some months 3 in the us and 6 in the uk after a non traumatic brain injury or one year after a traumatic injury nowadays more doctors and neuroscientists prefer to call the state of consciousness an unresponsive wakefulness syndrome primarily because of ethical questions about whether a patient can be called vegetative or not
in psychology personal distress is an aversive self focused emotional reaction e g anxiety worry discomfort to the apprehension or comprehension of another s emotional state or condition this negative affective state often occurs as a result of emotional contagion when there is confusion between self and other unlike empathy personal distress does not have to be congruent with the other s state and often leads to a self oriented egoistic reaction to reduce it by withdrawing from the stressor for example thereby decreasing the likelihood of prosocial behavior there is evidence that sympathy and personal distress are subjectively different have different somatic and physiological correlates and relate in different ways to prosocial behavior work in social neuroscience using functional neuroimaging shows that the perception of another individual in pain results in the observer in the activation of the neural network involved in the processing of firsthand experience of pain this intimate overlap between the neural circuits responsible for our ability to perceive the pain of others and those underlying our own self experience of pain can lead to personal distress and can possibly be detrimental to empathic concern personal distress may even result in a more egoistic motivation to reduce it by withdrawing from the stressor for example thereby decreasing the likelihood of prosocial behavior
in universal personal telecommunications upt personal mobility is the ability of a user to access telecommunication services at any upt terminal on the basis of a personal identifier and the capability of the network to provide those services in accord with the user s service profile personal mobility involves the network s capability to locate the terminal associated with the user for the purposes of addressing routing and charging the user for calls access is intended to convey the concepts of both originating and terminating services management of the service profile by the user is not part of personal mobility the personal mobility aspects of personal communications are based on the upt number
a personality development disorder is an inflexible and pervasive pattern of inner experience and behavior in children and adolescents that markedly deviates from the expectations of the individual s culture personality development disorder is not recognized as a mental disorder in any of the medical manuals such as the icd 10 or the dsm iv neither is it part of the proposed revision of this manual the dsm 5 dsm iv allows the diagnosis of personality disorders in children and adolescents only as an exception this diagnosis is currently proposed by a few authors in germany the term personality development disorder is used to emphasize the changes in personality development which might still take place and the open outcome during development personality development disorder is considered to be a childhood risk factor or early stage of a later personality disorder in adulthood adults usually show personality patterns over a long duration of time children and adolescents however still show marked changes in personality development some of these children and adolescents have a hard time developing their personalities in an ordinary way dsm iv states for example that children and adolescents are at higher risk to develop an antisocial personality disorder if they showed signs of conduct disorder and attention deficit disorder before the age of 10 this led adam breithaupt peters 2010 to the idea that these children and adolescents need to be looked at more carefully the therapy which these children and adolescents need might be more intense and maybe even different from looking at the disorders traditionally the concept of personality development disorders also focuses on the severity of the disorder and the poor prognosis an early diagnosis might help to get the right treatment at an early stage and thus might help to prevent a personality disorder outcome in adulthood
personality disorders are a class of mental disorders characterized by enduring maladaptive patterns of behavior cognition and inner experience exhibited across many contexts and deviating markedly from those accepted by the individual s culture these patterns develop early are inflexible and are associated with significant distress or disability the definitions may vary somewhat according to source official criteria for diagnosing personality disorders are listed in the diagnostic and statistical manual of mental disorders dsm and in the mental and behavioral disorders section of the international statistical classification of diseases and related health problems icd published by the world health organization who the dsm 5 lists personality disorders in the same way as other mental disorders rather than on a separate axis as previously personality defined psychologically is the set of enduring behavioral and mental traits that distinguish between individual humans hence personality disorders are defined by experiences and behaviors that differ from societal norms and expectations those diagnosed with a personality disorder may experience difficulties in cognition emotiveness interpersonal functioning or impulse control in general personality disorders are diagnosed in 40 – 60 of psychiatric patients making them the most frequent of psychiatric diagnosis personality disorders are characterized by an enduring collection of behavioral patterns often associated with considerable personal social and occupational disruption personality disorders are also inflexible and pervasive across many situations largely due to the fact that such behavior may be ego syntonic i e the patterns are consistent with the ego integrity of the individual and are therefore perceived to be appropriate for that individual this behavior can result in maladaptive coping skills which may lead to personal problems that induce extreme anxiety distress or depression these patterns of behavior typically are recognized in adolescence and the beginning of adulthood and in some unusual instances childhood many issues occur with classifying a personality disorder there are many categories of definition some mild and some extreme because the theory and diagnosis of personality disorders occur within prevailing cultural expectations their validity is contested by some experts on the basis of inevitable subjectivity they argue that the theory and diagnosis of personality disorders are based strictly on social or even sociopolitical and economic considerations
personality disorder not otherwise specified also known as personality disorder nos or pdnos is a dsm iv axis ii personality disorder conversely the dsm 5 does not have an equivalent to personality disorder nos the dsm 5 unspecified disorder is not a personality disorder it is used to enhance specificity of an existing disorder or it is an emergency diagnosis unto itself i e unspecified mental disorder 300 9 without being attached to another disorder
personnel psychology is a subfield of industrial and organizational psychology personnel psychology is the area of industrial organizational psychology that primarily deals with the recruitment selection and evaluation of personnel and other job aspects such as morale job satisfaction and relationships between managers and workers in the workplace it is the field of study that concentrates on the selection and evaluation of employees this area of psychology deals with job analysis and defines and measures job performance performance appraisal employment testing employment interviews employee selection and employee training and human factors and ergonomics
perspective n point is the problem of estimating the pose of a calibrated camera given a set of n 3 d points in the world and their corresponding 2 d projections in the image the camera pose consists of 6 degrees of freedom dof which are made up of the rotation roll pitch and yaw and 3 d translation of the camera with respect to the world this problem originates from camera calibration and has many applications in computer vision and other areas including 3 d pose estimation robotics and augmented reality a commonly used solution to the problem exists for n 3 called p 3 p and many solutions are available for the general case of n ≥ 3 implementations of these solutions are also available in open source software
pertussis also known as whooping cough or 100 day cough is a highly contagious bacterial disease initially symptoms are usually similar to those of the common cold with a runny nose fever and mild cough this is then followed by weeks of severe coughing fits following a fit of coughing a high pitched whoop sound or gasp may occur as the person breathes in the coughing may last for 10 or more weeks hence the phrase 100 day cough a person may cough so hard that they vomit break ribs or become very tired from the effort children less than one year old may have little or no cough and instead have periods where they do not breathe the time between infection and the onset of symptoms is usually seven to ten days disease may occur in those who have been vaccinated but symptoms are typically milder pertussis is caused by the bacterium bordetella pertussis it is an airborne disease which spreads easily through the coughs and sneezes of an infected person people are infectious to others from the start of symptoms until about three weeks into the coughing fits those treated with antibiotics are no longer infectious after five days diagnosis is by collecting a sample from the back of the nose and throat this sample can then be tested by either culture or by polymerase chain reaction prevention is mainly by vaccination with the pertussis vaccine initial immunization is recommended between six and eight weeks of age with four doses to be given in the first two years of life the vaccine becomes less effective over time with additional doses often recommended for older children and adults antibiotics may be used to prevent the disease in those who have been exposed and are at risk of severe disease in those with the disease antibiotics are useful if started within three weeks of the initial symptoms but otherwise have little effect in most people in children less than one year old and among those who are pregnant they are recommended within six weeks of symptom onset antibiotics used include erythromycin azithromycin clarithromycin or trimethoprim sulfamethoxazole evidence to support interventions other than antibiotics for the cough is poor many children less than a year of age require hospitalization an estimated 16 million people worldwide are infected per year most cases occur in the developing world and people of all ages may be affected in 2013 it resulted in 61 000 deaths – down from 138 000 deaths in 1990 nearly 0 5 of infected children less than one year of age die outbreaks of the disease were first described in the 16 th century the bacterium that causes the infection was discovered in 1906 the pertussis vaccine became available in the 1940 s
peruvian flamenco is a new phenomenon it can be seen as two art forms music and dance the only place in peru where peruvian flamenco is advertised as music is the jazz zone in the miraflores district of lima as for the dance it seems to be gaining momentum in england especially in the north as a dance peruvian flamenco is a variation of marinera the national dance of peru the main differences between peruvian flamenco and marinera are the music and the costumes worn
the peruvian horse sickness virus phsv is a cause of the neurological disorder peruvian horse sickness resulting in encephalitis in horses and other livestock the disease has significantly affected livestock in areas of peru and has also been documented in northern australia
the diagnostic category pervasive developmental disorders pdd as opposed to specific developmental disorders sdd refers to a group of five disorders characterized by delays in the development of multiple basic functions including socialization and communication the pervasive developmental disorders are pervasive developmental disorder not otherwise specified pdd nos which includes atypical autism and is the most common autism the best known now understood to be part of a spectrum asperger syndrome rett syndrome and childhood disintegrative disorder cdd the first three of these disorders are commonly called the autism spectrum disorders the last two disorders are much rarer and are sometimes placed in the autism spectrum and sometimes not the onset of pervasive developmental disorders occurs during infancy but the condition is usually not identified until the child is around three years old parents may begin to question the health of their child when developmental milestones are not met including age appropriate motor movement and speech production there is a division among doctors on the use of the term pdd many use the term pdd as a short way of saying pdd nos others use the general category label of pdd because they are hesitant to diagnose very young children with a specific type of pdd such as autism both approaches contribute to confusion about the term because the term pdd actually refers to a category of disorders and is not a diagnostic label
a pervasive developmental disorder not otherwise specified pdd nos is one of the three autism spectrum disorders asd and also one of the five disorders classified as a pervasive developmental disorder pdd according to the dsm iv pdd nos is a diagnosis that is used for severe and pervasive impairment in the development of reciprocal social interaction or verbal and nonverbal communication skills or when stereotyped behavior interests and activities are present but the criteria are not met for a specific pdd or for several other disorders pdd nos is often called atypical autism because the criteria for autistic disorder are not met for instance because of late age of onset atypical symptomatology or subthreshold symptomatology or all of these even though pdd nos is considered milder than typical autism this is not always true while some characteristics may be milder others may be more severe
pes anserine bursitis is an inflammatory condition of the medial inner knee at the anserine bursa a sub muscular bursa just below the pes anserinus
pes cavus in medical terminology also high instep high arch talipes cavus cavoid foot and supinated foot type is a human foot type in which the sole of the foot is distinctly hollow when bearing weight that is there is a fixed plantar flexion of the foot a high arch is the opposite of a flat foot and is somewhat less common
the peso problem in finance is a problem which arises when the possibility that some infrequent or unprecedented event may occur affects asset prices the difficulty or impossibility of predicting such an event creates problems in modeling the economy and financial markets by using the past it is useful in various contexts in particular in analyzing the forward premium anomaly
the fungus has been isolated from a wide variety of palm tissue the fungus is not host specific so the disease could be present in many more types of palm but further research needs to be done the fungus has also been known to infect pgymy date palm phoenix roebelenii and has been a big problem in florida during the winter months some varieties of bananas have also shown symptoms of the disease but it is unclear if it is in fact pestalotiopsis palmarum
a pesticide poisoning occurs when chemicals intended to control a pest affect non target organisms such as humans wildlife or bees there are three types of pesticide poisoning the first of the three is a single and short term very high level of exposure which can be experienced by individuals who commit suicide as well as pesticide formulators the second type of poisoning is long term high level exposure which can occur in pesticide formulators and manufacturers the third type of poisoning is a long term low level exposure which individuals are exposed to from sources such as pesticide residues in food as well as contact with pesticide residues in the air water soil sediment food materials plants and animals in developing countries such as sri lanka pesticide poisonings from short term very high level of exposure acute poisoning is the most worrisome type of poisoning however in developed countries such as canada it is the complete opposite acute pesticide poisoning is controlled thus making the main issue long term low level exposure of pesticides
the petabit is a multiple of the unit bit for digital information or computer storage the prefix peta symbol p is defined in the international system of units si as a multiplier of 1015 1 quadrillion short scale and therefore 1 petabit 1015 bits 1000000000000000 bits 1000 terabits the petabit has the unit symbol pbit or pb the petabit is closely related to the pebibit a unit multiple derived from the binary prefix pebi of the same order of magnitude which is equal to 250 bits 1125899906842624 bits or approximately 13 larger than the petabit
the petabyte is a multiple of the unit byte for digital information the prefix peta indicates the fifth power of 1000 and means 1015 in the international system of units si and therefore 1 petabyte is one quadrillion short scale bytes or 1 billiard long scale bytes the unit symbol for the petabyte is pb 1 pb 1000000000000000 b 1015 bytes 1000 terabytes a related unit the pebibyte pib using a binary prefix is equal to 10245 bytes which is more than 12 greater 250 bytes 1125899906842624 bytes
the petasis reaction alternatively called the petasis borono – mannich pbm reaction is the chemical reaction of an amine aldehyde and vinyl or aryl boronic acid to form substituted amines the petasis reaction reported in 1993 by nicos petasis as a practical method towards the synthesis of a geometrically pure antifungal agent naftifine the petasis reaction can be described as a variation of the mannich reaction rather than generating an enolate to form the substituted amine product in the petasis reaction the vinyl group of the organoboronic acid serves as the nucleophile in comparison to other methods of generating allyl amines the petasis reaction tolerates a multifunctional scaffold with a variety of amines and organoboronic acids as potential starting materials additionally the reaction does not require anhydrous or inert conditions as a mild selective synthesis the petasis reaction is useful in generating α amino acids and is utilized in combinatorial chemistry and drug discovery
krause – van schooneveld – kivlin syndrome is a hereditary syndrome that mainly affects the eyes growth and development of the individual it is also known as krause – kivlin syndrome or peters plus syndrome features of this syndrome include peters anomaly leukoma corneal opacity central defect of descemet s membrane and shallow anterior chamber with synechiae between the iris and cornea it is associated with short limb dwarfism and delayed mental development krause – van schooneveld – kivlin syndrome is listed as a rare disease by the office of rare diseases ord of the national institutes of health nih which means that the syndrome or a subtype affects fewer than 200 000 people in the united states it is associated with the enzyme b 3 galtl it was characterized in 1984 by van schooneveld
the peterson olefination also called the peterson reaction is the chemical reaction of α silyl carbanions 1 with ketones or aldehydes to form a β hydroxysilane 2 which eliminates to form alkenes 3 the peterson olefination several reviews have been published
petit s hernia is a hernia that protrudes through the lumbar triangle this triangle lies in the posterolateral abdominal wall and is bounded anteriorly by the free margin of external oblique muscle posteriorly by the latissimus dorsi and inferiorly by the iliac crest the neck the spot where the hernia protrudes into the opening is large and therefore this hernia has a lower risk of strangulating than some other hernias petit s hernia occurs more often in males than in females and more often on the left side than on the right
the petrenko kritschenko reaction is a classic multicomponent name reaction that is closely related to the robinson – schöpf tropinone synthesis but was published 12 years earlier
petty cash is a small amount of discretionary funds in the form of cash used for expenditures where it is not sensible to make any disbursement by cheque because of the inconvenience and costs of writing signing and then cashing the cheque the most common way of accounting for petty cash expenditures is to use the imprest system the initial fund would be created by issuing a cheque for the desired amount an amount of 100 would typically be sufficient for most small business needs as the expenses to be covered are for small amounts the bookkeeping entry for this initial fund would be to debit petty cash and credit bank account as expenditures are made the custodian of the fund will reimburse employees and receive a petty cash voucher with a receipt invoice attached in return at any given time the total of cash on hand plus reimbursed vouchers must equal the original fund when the fund gets low e g 20 remaining the custodian a bookkeeper or a member of the administration staff requests a top up and submits the vouchers for reimbursement assuming the vouchers add up to 80 an 80 top up cheque is issued and an 80 debit towards office expenses is recorded once the cheque is cashed the custodian again has cash at the original amount of 100
peutz – jeghers syndrome often abbreviated pjs is an autosomal dominant genetic disorder characterized by the development of benign hamartomatous polyps in the gastrointestinal tract and hyperpigmented macules on the lips and oral mucosa melanosis this syndrome can be classed as one of various hereditary intestinal polyposis syndromes and one of various hamartomatous polyposis syndromes it has an incidence of approximately 1 in 25 000 to 300 000 births
peyronie s disease or peyronie disease peɪroʊˈniː also known as induratio penis plastica ipp or chronic inflammation of the tunica albuginea cita is a connective tissue disorder involving the growth of fibrous plaques in the soft tissue of the penis affecting an estimated 5 of men specifically scar tissue forms in the tunica albuginea the thick sheath of tissue surrounding the corpora cavernosa causing pain abnormal curvature erectile dysfunction indentation loss of girth and shortening a variety of treatments have been used but none have been especially effective
pfeiffer syndrome is a very rare genetic disorder characterized by the premature fusion of certain bones of the skull which affects the shape of the head and face in addition the syndrome includes abnormalities of the hands such as wide and deviated thumbs and feet such as wide and deviated big toes pfeiffer syndrome affects about 1 in 100 000 births
the pfitzinger reaction also known as the pfitzinger borsche reaction is the chemical reaction of isatin with base and a carbonyl compound to yield substituted quinoline 4 carboxylic acids the pfitzinger reaction several reviews have been published
the pfitzner – moffatt oxidation sometimes referred to as simply the moffatt oxidation is a chemical reaction which describes the oxidation of primary and secondary alcohols by dimethyl sulfoxide dmso activated with a carbodiimide such as dicyclohexylcarbodiimide dcc the resulting alkoxysulfonium ylide rearranges to generate aldehydes and ketones respectively pfitzner moffatt oxidation of isopropyl alcohol this reaction has been largely abandoned for the swern oxidation which gives higher yields with fewer side products the moffatt oxidation yields urea by products that are often difficult to remove several reviews have been published reaction mechanism is as follows
phakomatoses or neuro oculo cutaneous syndromes neurocutaneous disorders are multisystem disorders that have characteristic central nervous system ocular and cutaneous lesions of variable severity the skin and the brain have a common ectodermal origin so there are many genetic and acquired diseases that affect both tissues however in some conditions such as von hippel lindau disease ectodermal presentation is minimal the term from the greek φακός phakos spot lens suffix o ma ωμα and the suffix osis also called mother s spot or birth mark was introduced by jan van der hoeve in 1920 before the distinct genetic basis of each of these diseases was understood
phakomatosis pigmentokeratotica is a cutaneous condition characterized by the combination of an organoid sebaceous nevus and speckled lentiginous nevus
the phantom eye syndrome pes is a phantom pain in the eye and visual hallucinations after the removal of an eye enucleation evisceration
a phantom limb is the sensation that an amputated or missing limb is still attached approximately 60 to 80 of individuals with an amputation experience phantom sensations in their amputated limb and the majority of the sensations are painful phantom sensations may also occur after the removal of body parts other than the limbs e g after amputation of the breast extraction of a tooth phantom tooth pain or removal of an eye phantom eye syndrome
a phantom limb is the sensation by an amputee that an amputated or missing limb is still attached to the body phantom limb may also refer to phantom limb album by pig destroyer phantom limb band from bristol england phantom limb character a fictional character in the venture bros cartoon phantom limb song by the shins phantom limb song by the spanish youtuber and singer yellow mellow phantom limb a song by alice in chains from the devil put dinosaurs here the phantom limbs an american music band phantom limbs selected b sides a compilation double album by australian band something for kate disambig
phantom pain sensations are described as perceptions that an individual experiences relating to a limb or an organ that is not physically part of the body limb loss is a result of either removal by amputation or congenital limb deficiency however phantom limb sensations can also occur following nerve avulsion or spinal cord injury sensations are recorded most frequently following the amputation of an arm or a leg but may also occur following the removal of a breast or an internal organ phantom limb pain is the feeling of pain in an absent limb or a portion of a limb the pain sensation varies from individual to individual phantom limb sensation is the term given to any sensory phenomenon except pain which is felt at an absent limb or a portion of the limb it has been known that at least 80 of amputees experience phantom sensations at some time of their lives some experience some level of this phantom pain and feeling in the missing limb for the rest of their lives the term phantom limb was first coined by american neurologist silas weir mitchell in 1871 mitchell described that thousands of spirit limbs were haunting as many good soldiers every now and then tormenting them however in 1551 french military surgeon ambroise paré recorded the first documentation of phantom limb pain when he reported that for the patients long after the amputation is made say that they still feel pain in the amputated part
phantom practice is the purported phenomenon in which a person s abilities continue to improve even without practicing at all it is mostly associated with practicing a musical instrument after habitual practicing a person may believe that they have continued to experience improvement even after they stop practicing whether these individuals have actually improved or whether it is simply a subjective perception on their part has not been ascertained by researchers
phantom vibration syndrome or phantom ringing is the perception that one s mobile phone is vibrating or ringing when it is not ringing other terms for this concept include ringxiety a portmanteau of ring and anxiety and fauxcellarm a play on false alarm according to dr michael rothberg the term is not technically a syndrome but is better characterised as a tactile hallucination since the brain perceives a sensation that is not present phantom ringing may be experienced while taking a shower watching television or using a noisy device humans are particularly sensitive to auditory tones between 1 000 and 6 000 hertz and basic mobile phone ringers often fall within this range phantom vibrations develop after carrying a cell phone set to use vibrating alerts researcher michelle drouin found that almost 9 of 10 undergraduates at her college experienced phantom vibrations
pharyngitis is inflammation of the back of the throat known as the pharynx it typically results in a sore throat and fever other symptoms may include a runny nose cough headache a hoarse voice symptoms usually last three to five days complications can include sinusitis and acute otitis media pharyngitis is typically a type of respiratory tract infection most cases are caused by a viral infection strep throat is the cause in about 25 of children and 10 of adults uncommon causes include other bacteria such as gonorrhea fungus irritants such as smoke allergies and gastroesophageal reflux disease specific testing is not recommended in people who have clear symptoms of a viral infection such as a cold otherwise a rapid antigen detection test or throat swab is recommended other conditions that can produce similar symptoms include epiglottitis thyroiditis retropharyngeal abscess and occasionally heart disease nsaids such as ibuprofen can be used to help with the pain topical lidocaine may also help strep throat is typically treated with antibiotics such as either penicillin or amoxicillin it is unclear if steroids are useful in acute pharyngitis other than possibly in severe cases about 7 5 of people have a sore throat in any three month period this resulted in 15 million physician visits in the united states in 2007 pharyngitis is the most common cause of a sore throat on the average adults get a sore throat two to three times a year and children about five times a year the word comes from the greek word pharynx meaning throat and the suffix itis meaning inflammation
a phase detector characteristic is a function of phase difference describing the output of the phase detector for the analysis of phase detector it is usually considered the modelsof pd in signal time domain and phase frequency domain in this case for constructing of an adequate nonlinear mathematical model of pd in phase frequency domain it is necessary to find the characteristic of phase detector the inputs of pd are high frequency signals and the output contains a low frequency error correction signal corresponding to a phase difference of input signals for the suppression of high frequency component of the output of pd if such component exists a low pass filter is applied thecharacteristic of pd is the dependence of the signal at theoutput of pd in the phase frequency domain on the difference of phases at the input of pd this characteristic of pd depends on the realization of pd and the types of waveforms of signals consideration of pd characteristic allows to apply averaging methods for high frequency oscillations and to pass from analysis and simulation of non autonomous models of phase synchronization systems in time domain to analysis and simulation of autonomous dynamical models in phase frequency domain
phase inversion is a chemical phenomenon exploited in the fabrication of artificial membranes it is performed by removing the solvent from a liquid polymer solution leaving a porous solid membrane
in electronic amplifiers the phase margin pm is the difference between the phase and 180 ° for an amplifier s output signal relative to its input at a certain frequency typically the open loop phase lag relative to input varies with frequency progressively increasing to exceed 180 ° at which frequency the output signal becomes inverted or antiphase in relation to the input the pm will be positive but decreasing at frequencies less than the frequency at which inversion sets in at which pm 0 and pm is negative pm 0 at higher frequencies in the presence of negative feedback a zero or negative pm at a frequency where the loop gain exceeds unity 1 guarantees instability thus positive pm is a safety margin that ensures proper non oscillatory operation of the circuit this applies to amplifier circuits as well as more generally to active filters under various load conditions e g reactive loads in its simplest form involving ideal negative feedback voltage amplifiers with non reactive feedback the phase margin is measured at the frequency where the open loop voltage gain of the amplifier equals the desired closed loop dc voltage gain more generally pm is defined as that of the amplifier and its feedback network combined the loop normally opened at the amplifier input measured at a frequency where the loop gain is unity and prior to the closing of the loop through tying the output of the open loop to the input source in such a way as to subtract from it in the above loop gain definition it is assumed that the amplifier input presents zero load to make this work for non zero load input the output of the feedback network needs to be loaded with an equivalent load for the purpose of determining the frequency response of the loop gain it is also assumed that the graph of gain vs frequency crosses unity gain with a negative slope and does so only once this consideration matters only with reactive and active feedback networks as may be the case with active filters phase margin and its important companion concept gain margin are measures of stability in closed loop dynamic control systems phase margin indicates relative stability the tendency to oscillate during its damped response to an input change such as a step function gain margin indicates absolute stability and the degree to which the system will oscillate without limit given any disturbance the output signals of all amplifiers exhibit a time delay when compared to their input signals this delay causes a phase difference between the amplifier s input and output signals if there are enough stages in the amplifier at some frequency the output signal will lag behind the input signal by one cycle period at that frequency in this situation the amplifier s output signal will be in phase with its input signal though lagging behind it by 360 ° i e the output will have a phase angle of − 360 ° this lag is of great consequence in amplifiers that use feedback the reason the amplifier will oscillate if the fed back output signal is in phase with the input signal at the frequency at which its open loop voltage gain equals its closed loop voltage gain and the open loop voltage gain is one or greater the oscillation will occur because the fed back output signal will then reinforce the input signal at that frequency in conventional operational amplifiers the critical output phase angle is − 180 ° because the output is fed back to the input through an inverting input which adds an additional − 180 ° in practice feedback amplifiers must be designed with phase margins substantially in excess of 0 ° even though amplifiers with phase margins of say 1 ° are theoretically stable the reason is that many practical factors can reduce the phase margin below the theoretical minimum a prime example is when the amplifier s output is connected to a capacitive load therefore operational amplifiers are usually compensated to achieve a minimum phase margin of 45 ° or so this means that at the frequency at which the open and closed loop gains meet the phase angle is − 135 ° the calculation is 135 ° 180 ° 45 ° see warwickor stoutfor a detailed analysis of the techniques and results of compensation to insure adequate phase margins see also the article pole splitting often amplifiers are designed to achieve a typical phase margin of 60 degrees if the typical phase margin is around 60 degrees then the minimum phase margin will typically be greater than 45 degrees a phase margin of 60 degrees is also a magic number because it allows for the fastest settling time when attempting to follow a voltage step input a butterworth design an amplifier with lower phase margin will ring for longer and an amplifier with more phase margin will take a longer time to rise to the voltage step s final level a related measure is gain margin while phase margin comes from the phase where the loop gain equals one the gain margin is based upon the gain where the phase equals 180 degrees
phase modulation pm is a modulation pattern that encodes information as variations in the instantaneous phase of a carrier wave phase modulation is widely used for transmitting radio waves and is an integral part of many digital transmission coding schemes that underlie a wide range of technologies like wifi gsm and satellite television phase modulation is closely related to frequency modulation fm it is often used as an intermediate step to achieve fm mathematically both phase and frequency modulation can be considered a special case of quadrature amplitude modulation qam pm is used for signal and waveform generation in digital synthesizers such as the yamaha dx 7 to implement fm synthesis a related type of sound synthesis called phase distortion is used in the casio cz synthesizers
in the dungeons dragons fantasy role playing game the phasm is an aberration
phenomicdb is a free phenotype oriented database it contains data for some of the main model organisms such as homo sapiens mus musculus drosophila melanogaster and others phenomicdb merges and structures phenotypic data from various public sources wormbase flybase ncbi gene mgi and zfin using clustering algorithms
phenotypic plasticity is the ability of an organism to change its phenotype in response to changes in the environment fundamental to the way in which organisms cope with environmental variation phenotypic plasticity encompasses all types of environmentally induced changes e g morphological physiological behavioural phenological that may or may not be permanent throughout an individual ’ s lifespan the term was originally used to describe developmental effects on morphological characters but is now more broadly used to describe all phenotypic responses to environmental change such as acclimation or acclimatization as well as learning the special case when differences in environment induce discrete phenotypes is termed polyphenism generally phenotypic plasticity is more important for immobile organisms e g plants than mobile organisms e g most animals as mobile organisms can often move away from unfavourable environments nevertheless mobile organisms also have at least some degree of plasticity in at least some aspects of the phenotype one mobile organism with substantial phenotypic plasticity is acyrthosiphon pisum of the aphid family which exhibits the ability to interchange between asexual and sexual reproduction as well as growing wings between generations when plants become too populated
phenylketonuria pku is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine untreated pku can lead to intellectual disability seizures behavioral problems and mental disorder it may also result in a musty smell and lighter skin babies born to mothers who have poorly treated pku may have heart problems a small head and low birth weight phenylketonuria is a genetic disorder inherited from a person s parents it is due to mutations in the pah gene which results in low levels of the enzyme phenylalanine hydroxylase this results in the build up of dietary phenylalanine to potentially toxic levels it is autosomal recessive meaning that both copies of the gene must be mutated for the condition to develop there are two main types classic pku and variant pku depending on if any enzyme function remains those with one copy of a mutated gene typically do not have symptoms many countries have newborn screening programs for the disease treatment is with a diet low in foods that contain phenylalanine and special supplements babies should use a special formula the diet should begin as soon as possible after birth and be lifelong people who are diagnosed early and maintain a strict diet can have normal health and a normal life span effectiveness is monitored through periodic blood tests the medication sapropterin dihydrochloride may be useful in some phenylketonuria affects about one in 10 000 to 25 000 babies males and females are affected equally the disease was discovered in 1934 by ivar asbjørn følling with the importance of diet determined in 1953 gene therapy while promising requires a great deal more study as of 2014
a pheochromocytoma from greek phaios dark chroma color kytos cell oma tumor or phaeochromocytoma pcc is a neuroendocrine tumor of the medulla of the adrenal glands originating in the chromaffin cells or extra adrenal chromaffin tissue that failed to involute after birth that secretes high amounts of catecholamines mostly norepinephrine plus epinephrine to a lesser extent extra adrenal paragangliomas often described as extra adrenal pheochromocytomas are closely related though less common tumors that originate in the ganglia of the sympathetic nervous system and are named based upon the primary anatomical site of origin
the philadelphia chromosome or philadelphia translocation is a specific genetic abnormality in chromosome 22 of leukemia cancer cells particularly chronic myelogenous leukemia cml cells this chromosome is defective and unusually short because of reciprocal translocation of genetic material between chromosome 9 and chromosome 22 and contains a fusion gene called bcr abl 1 this gene is the abl 1 gene of chromosome 9 juxtaposed onto the bcr gene of chromosome 22 coding for a hybrid protein a tyrosine kinase signalling protein that is always on causing the cell to divide uncontrollably the presence of this translocation is a highly sensitive test for cml since 95 of people with cml have this abnormality the remainder have either a cryptic translocation that is invisible on g banded chromosome preparations or a variant translocation involving another chromosome or chromosomes as well as the long arm of chromosomes 9 and 22 however the presence of the philadelphia ph chromosome is not sufficiently specific to diagnose cml since it is also found in acute lymphoblastic leukemia all 25 – 30 in adult and 2 – 10 in pediatric cases and occasionally in acute myelogenous leukemia aml
the philosophy of biology is a subfield of philosophy of science which deals with epistemological metaphysical and ethical issues in the biological and biomedical sciences although philosophers of science and philosophers generally have long been interested in biology e g aristotle descartes and even kant philosophy of biology only emerged as an independent field of philosophy in the 1960 s and 1970 s philosophers of science then began paying increasing attention to biology from the rise of neodarwinism in the 1930 s and 1940 s to the discovery of the structure of dna in 1953 to more recent advances in genetic engineering other key ideas include the reduction of all life processes to biochemical reactions and the incorporation of psychology into a broader neuroscience
phimosis is a condition of the penis where the foreskin cannot be fully retracted over the glans penis the term may also refer to clitoral phimosis in women whereby the clitoral hood cannot be retracted limiting exposure of the glans clitoridis at birth the foreskin is fused to the glans and is not retractable for some males non retractability may be normal until the age of adolescence normal developmental non retractability does not cause any problems phimosis is deemed pathological when it causes problems such as difficulty urinating or performing common sexual functions there are numerous causes of so called pathological phimosis nonsurgical treatment involves the stretching of the foreskin steroid creams and changing masturbation habits surgical treatments include preputioplasty and circumcision the word is from the greek phimos φῑμός muzzle
phlebitis or venitis is the inflammation of a vein usually in the legs it most commonly occurs in superficial veins phlebitis often occurs in conjunction with thrombosis and is then called thrombophlebitis or superficial thrombophlebitis unlike deep vein thrombosis the probability that superficial thrombophlebitis will cause a clot to break up and be transported in pieces to the lung is very low
phlegmasia alba dolens also colloquially known as milk leg or white leg is part of a spectrum of diseases related to deep vein thrombosis historically it was commonly seen during pregnancy and in mothers who have just given birth in cases of pregnancy it is most often seen during the third trimester resulting from a compression of the left common iliac vein against the pelvic rim by the enlarged uterus today this disease is most commonly 40 of the time related to some form of underlying malignancy hypercoagulability a propensity to clot formation is a well known state that occurs in many cancer states the incidence of this disease is not well reported the disease presumably begins with a deep vein thrombosis that progresses to total occlusion of the deep venous system it is at this stage that it is called phlegmasia alba dolens it is a sudden acute process the leg then must rely on the superficial venous system for drainage the superficial system is not adequate to handle the large volume of blood being delivered to the leg via the arterial system the result is edema pain and a white appearance alba of the leg the next step in the disease progression is occlusion of the superficial venous system thereby preventing all venous outflow from the extremity at this stage it is called phlegmasia cerulea dolens the leg becomes more swollen and increasingly more painful additionally the edema and loss of venous outflow impedes the arterial inflow ischemia with progression to gangrene are potential consequences phlegmasia alba dolens is distinguished clinically from phlegmasia cerulea dolens in that there is no ischemia
a phobia is a type of anxiety disorder defined by a persistent fear of an object or situation the phobia typically results in a rapid onset of fear and is present for more than six months the affected person will go to great lengths to avoid the situation or object typically to a degree greater than the actual danger posed if the feared object or situation cannot be avoided the affected person will have significant distress with blood or injury phobia fainting may occur agoraphobia is often associated with panic attacks usually a person has phobias to a number of objects or situations phobias can be divided into specific phobias social phobia and agoraphobia types of specific phobias include to certain animals natural environment situations blood or injury and specific situations the most common are fear of spiders fear of snakes and fear of heights occasionally they are triggered by a negative experience with the object or situation social phobia is when the situation is feared as the person is worried about others judging them agoraphobia is when fear of a situation occurs because it is felt that escape would not be possible specific phobias should be treated with exposure therapy where the person is introduced to the situation or object in question until the fear resolves medications are not useful in this type of phobia social phobia and agoraphobia are often treated with some combination of counselling and medication medications used include antidepressants benzodiazepines or beta blockers specific phobias affect about 6 8 of people in the western world and 2 4 of people in asian africa and latin america in a given year social phobia affects about 7 of people in the united states and 0 5 2 5 of people in the rest of the world agoraphobia affects about 1 7 of people women are affected about twice as often as men typically onset is around the age of 10 to 17 rates become lower as people get older people with phobias are at a higher risk of suicide
phocomelia from ancient greek φώκη phōkē seal animal o interfix μέλος melos limb english suffix ia is an extremely rare congenital disorder involving malformation of the limbs dysmelia étienne geoffroy saint hilaire coined the term in 1836 although many factors can cause phocomelia the prominent roots come from the use of the drug thalidomide and from genetic inheritance occurrence in an individual results in various abnormalities to the face limbs ears nose vessels and many other underdevelopments although operations may improve some abnormalities many are not surgically treatable due to the lack of nerves and other related structures
a phoenix abscess is a dental abscess that can occur immediately following root canal treatment another cause is due to untreated necrotic pulp chronic apical periodontitis it is also the result of inadequate debridement during the endodontic procedure risk of occurrence of a phoenix abscess is minimised by correct identification and instrumentation of the entire root canal ensuring no missed anatomy treatment involves repeating the endodontic treatment with improved debridement or tooth extraction antibiotics might be indicated to control a spreading or systemic infection
phomopsis blight of juniper is a foliar disease discovered in 1917 caused by the fungal pathogen phomopsis juniperovora the fungus infects new growth of juniper trees or shrubs i e the seedlings or young shoots of mature trees infection begins with the germination of asexual conidia borne from pycnidia on susceptible tissue the mycelia gradually move inwards down the branch and into the main stem management strategies mainly include removing and destroying diseased tissue and limiting the presence of moisture on plants junipers become resistant to infection as they mature and the young yellow shoots turn dark green preventative strategies include planting only resistant varieties and spraying new growth with fungicide until plants have matured
phone tag is a phenomenon in which two parties attempt to contact each other by telephone but neither is able to get a hold of the other for a conversation both parties may leave a message on the answering machine or voicemail of the other and request a call back this continues for a period of time often with the two parties exchanging attempts to have a real time conversation the name derives from the playground game tag where players chase one another in turn phone tag became common in the 1980 s with the advent of messaging technologies and caller id it was seen as having advantages in that people could leave and receive messages at their convenience rather than having to find a common time with the other party to have a conversation phone tag like later messaging inventions such as text messaging via sms and whatsapp facilitates selectivity in communications
phonemic restoration effect is a perceptual phenomenon where under certain conditions sounds actually missing from a speech signal can be restored by the brain and may appear to be heard the effect occurs when missing phonemes in an auditory signal are replaced with a masking noise resulting in the brain filling in absent phonemes the effect can be so strong that some listeners may not even notice that there are phonemes missing this effect is commonly observed in a conversation with heavy background noise making it difficult to properly hear every phoneme being spoken different factors can change the strength of the effect including age and gender this effect is more important to humans than what was initially thought linguists have pointed out that at least the english language has many false starts and extraneous sounds the phonemic restoration effect is the brain s way of resolving those imperfections in our speech without this effect interfering with our language processing there would be a greater need for much more accurate speech signals and human speech could require much more precision for experiments white noise is necessary because it takes the place of these imperfections in speech one of the most important factors in language is continuity and in turn intelligibility
phonophobia also called ligyrophobia or sonophobia is a fear of or aversion to loud sounds — a type of specific phobia it can also mean a fear of voices or a fear of one s own voice it is a very rare phobia which is often the symptom of hyperacusis sonophobia can refer to the hypersensitivity of a patient to sound and can be part of the diagnosis of a migraine occasionally it is called acousticophobia the term phonophobia comes from greek φωνή phōnē sound and φόβος phobos fear ligyrophobics may be fearful of devices that can suddenly emit loud sounds such as computer speakers or fire alarms when operating a home theater system computer television cd player etc they may wish to have the volume turned down all the way before doing anything that would cause the speakers to emit sound so that once the command to produce sound is given the user can raise the volume of the speakers to a comfortable listening level they may avoid parades and carnivals due to the loud instruments such as drums as festive occasions are accompanied by music of over 120 decibels many phobics develop agoraphobia other ligyrophobics also steer clear of any events in which fireworks are to be let off another example is watching someone blow up a balloon beyond its normal capacity this is often an unsettling even disturbing thing for a person with ligyrophobia to observe as he or she anticipates a loud sound when the balloon pops when balloons pop two types of reactions are heavy breathing and panic attacks the sufferer becomes anxious to get away from the source of the loud sound and may get headaches it may also be related to caused by or confused with hyperacusis extreme sensitivity to loud sounds phonophobia also refers to an extreme form of misophonia
phosphaturic mesenchymal tumor is an extremely rare benign neoplasm of soft tissue and bone that inappropriately produces fibroblast growth factor 23 this tumor may cause tumor induced osteomalacia a paraneoplastic syndrome by the secretion of fgf 23 which has phosphaturic activity by inhibition of renal tubular reabsorption of phosphate and renal conversionof 25 hydroxyvitamin d to 1 25 dihydroxyvitamin d the paraneoplastic effects can be debilitating and are only reversed on discovery and surgical resection of the tumour
a phosphene is a phenomenon characterized by the experience of seeing light without light actually entering the eye the word phosphene comes from the greek words phos light and phainein to show phosphenes that are induced by movement or sound are often associated with optic neuritis phosphenes can be directly induced by mechanical electrical or magnetic stimulation of the retina or visual cortex as well as by random firing of cells in the visual system phosphenes have also been reported by meditators commonly called nimitta people who go for long periods without visual stimulation also known as the prisoner s cinema or those who are using psychedelic drugs
phosphofructokinase deficiency also known as glycogen storage disease type vii or tarui s disease is a muscular metabolic disorder with an autosomal recessive inheritance pattern it may affect humans as well as other mammals especially dogs in humans it is the least common type of glycogen storage disease it was named after the japanese physician seiichiro tarui 1927 – who first observed the condition in 1965
phospholipidosis is a lysosomal storage disorder characterized by the excess accumulation of phospholipids in tissues many cationic amphiphilic drugs including anti depressants antianginal antimalarial and cholesterol lowering agents are reported to cause drug induced phospholipidosis dipl in animals and humans the mechanisms of dipl involve trapping or selective uptake of dipl drugs within the lysosomes and acidic vesicles of affected cells drug trapping is followed by a gradual accumulation of drug phospholipid complexes within the internal lysosomal membranes the increase in undigested materials results in the abnormal accumulation of multi lammellar bodies myeloid bodies in tissues it is not possible to predict which tissues will be affected by dipl in animals and humans the use of specific in vitro cell lines is not recommended as a means of gate keeping for dipl screening only as part of an iterative process an in vivo screening platform such as biomarker is required for preclinical and clinical dipl assessment the traditional method to evaluate dipl is visual confirmation of myeloid bodies in tissues by electron microscopy electron microscopy has limited utility to monitor dipl in humans because of the invasive nature of acquiring patient tissue biopsy samples a qualified biomarker of dipl in the blood or urine is needed to provide a more routine non invasive and cost effective means to monitor dipl in the clinic
phosphonium coupling is a chemical reaction in organic chemistry for organic synthesis it is a mild efficient chemoselective and versatile methodology for the direct c – c c – n c – o and c – s bond formations of unactivated and unprotected tautomerizable heterocycles
phosphorus deficiency is a plant disorder associated with insufficient supply of phosphorus phosphorus refers here to salts of phosphates po 43 − monohydrogen phosphate hpo 42 − and dihydrogen phosphate h 2 po 4 − these anions readily interconvert and the predominant species is determined by the ph of the solution or soil phosphates are required for the biosynthesis of genetic material as well as atp essential for life phosphorus deficiency can be controlled by applying sources of phosphorus such as bone meal rock phosphate manure and phosphate fertilizers
phossy jaw formally phosphorus necrosis of the jaw is an occupational disease of those who work with white phosphorus also known as yellow phosphorus without proper safeguards it was most commonly seen in workers in the match industry in the 19 th and early 20 th century modern occupational hygiene practices have eliminated the working conditions which caused this disease
the photic sneeze reflex also known as photoptarmosis autosomal dominant compelling helio ophthalmic outburst syndrome achoo and colloquially sun sneezing is a condition that causes variable difficulty to control sneezing in response to numerous stimuli such as looking at bright lights or periocular surrounding the eyeball injection the condition affects 18 – 35 of the population in the united states but its exact mechanism of action is not well understood
in optics photobleaching sometimes termed fading is the photochemical alteration of a dye or a fluorophore molecule such that it permanently is unable to fluoresce this is caused by cleaving of covalent bonds or non specific reactions between the fluorophore and surrounding molecules in microscopy photobleaching may complicate the observation of fluorescent molecules since they will eventually be destroyed by the light exposure necessary to stimulate them into fluorescing this is especially problematic in time lapse microscopy however photobleaching may also be used prior to applying the primarily antibody linked fluorescent molecules in an attempt to quench autofluorescence this can help to improve signal to noise ratio photobleaching may also be exploited to study the motion and or diffusion of molecules for example via the frap or flip techniques loss of activity caused by photobleaching can be controlled by reducing the intensity or time span of light exposure by increasing the concentration of fluorophores by reducing the frequency and thus the photon energy of the input light or by employing more robust fluorophores that are less prone to bleaching e g alexa fluors or dylight fluors to a reasonable approximation a given molecule will be destroyed after a constant exposure intensity of emission x emission time x number of cycles because in a constant environment each absorption emission cycle has an equal probability of causing photobleaching
photoconductivity is an optical and electrical phenomenon in which a material becomes more electrically conductive due to the absorption of electromagnetic radiation such as visible light ultraviolet light infrared light or gamma radiation when light is absorbed by a material such as a semiconductor the number of free electrons and electron holes increases and raises its electrical conductivity to cause excitation the light that strikes the semiconductor must have enough energy to raise electrons across the band gap or to excite the impurities within the band gap when a voltage and a resistor are used in series with the semiconductor a voltage drop across the load resistors can be measured when the change in electrical conductivity of the material varies the current through the circuit classic examples of photoconductive materials include the conductive polymer vinylcarbazole used extensively in photocopying lead sulfide used in infrared detection applications such as the u s s enterprise and soviet now russian atoll heat seeking missiles selenium employed in early television and xerography
photodarkening is an optical effect observed in the interaction of laser radiation with amorphous media glasses in optical fibers until now such creation of color centers was reported only in glassfibers photodarkening limits the density of excitations in fiber lasers
photo degradation is the alteration of materials by light typically the term refers to the combined action of sunlight and air photo degradation is usually oxidation and hydrolysis often photodegradation is avoided since it destroys paintings and other artifacts it is however partly responsible for remineralization of biomass and is used intentionally in some disinfection technologies photodegradation does not apply to how materials may be aged or degraded via infrared light or heat but does include degradation in all of the ultravioliet light wavebands
photodermatitis sometimes referred to as sun poisoning or photoallergy is a form of allergic contact dermatitis in which the allergen must be activated by light to sensitize the allergic response and to cause a rash or other systemic effects on subsequent exposure the second and subsequent exposures produce photoallergic skin conditions which are often eczematous in rare cases the victims die
photodermatosis is a skin disease that is caused by exposure to sunlight people with photodermatosis may develop skin rashes following exposure to the sun polymorphous light eruption is the most common type of photodermatosis it is most likely due to an abnormal immune system reaction to the sun polymorphous light eruption occurs in approximately 10 to 20 percent of otherwise healthy individuals so it is a relatively common condition
photodissociation photolysis or photodecomposition is a chemical reaction in which a chemical compound is broken down by photons it is defined as the interaction of one or more photons with one target molecule photodissociation is not limited to visible light any photon with sufficient energy can affect the chemical bonds of a chemical compound since a photon s energy is inversely proportional to its wavelength electromagnetic waves with the energy of visible light or higher such as ultraviolet light x rays and gamma rays are usually involved in such reactions
photoelectrochemistry is a subfield of study within physical chemistry concerned with the interaction of light with electrochemical systems it is an active domain of investigation one of the pioneers of this field of electrochemistry was the german electrochemist heinz gerischer the interest in this domain is high in the context of development of renewable energy conversion and storage technology
photokeratitis or ultraviolet keratitis is a painful eye condition caused by exposure of insufficiently protected eyes to the ultraviolet uv rays from either natural e g intense sunlight or artificial e g the electric arc during welding sources photokeratitis is akin to a sunburn of the cornea and conjunctiva and is not usually noticed until several hours after exposure symptoms include increased tears and a feeling of pain likened to having sand in the eyes the injury may be prevented by wearing eye protection that blocks most of the ultraviolet radiation such as welding goggles with the proper filters a welder s helmet sunglasses rated for sufficient uv protection or appropriate snow goggles the condition is usually managed by removal from the source of ultraviolet radiation covering the corneas and administration of pain relief photokeratitis is known by a number of different terms including snow blindness arc eye welder s flash bake eyes corneal flash burns flash burns niphablepsia or keratoconjunctivitis photoelectrica
photoleukomelanodermatitis of kobori is a cutaneous condition a dyschromic drug eruption that occurs after ingestion of afloqualone thiazides or tetracyclines followed by exposure to sunlight
the photomagnetic effect is a theoretical quantum mechanical effect discovered by the researchers samuel l oliveira and stephen c rand at university of michigan 2007 – 2011 the researchers have discovered a powerful magnetic interaction between the photons dynamic magnetic field – and certain isolator materials atoms magnetic moment that is 100 million times stronger than formerly anticipated under the proper circumstances the photons magnetic fields effect is as strong as their electric field – as e g in solar cells the discovery is a surprise because it is not straightforward to derive the strong magnetic effect from the physical equations and thereby indicate that this quantum mechanical effect would be interesting enough that is why the photomagnetic effect has been neglected for more than 100 years the researchers have theoretically calculated that incoherent light as e g sunlight is almost as efficient as laserlight to be converted by the photomagnetic effect the power density should be 10 million watt per square centimeter but the researchers will look for new photomagnetic materials that can work with lower light intensities
the photomagnetic effect is the effect in which a material acquires and in some cases loses its ferromagnetic properties in response to light the current model for this phenomenon is a light induced electron transfer accompanied by the reversal of the spin direction of an electron this leads to an increase in spin concentration causing the magnetic transition currently the effect is only observed to persist for any significant time at very low temperature but at temperatures such as 5 k the effect may persist for several days
in physics photon induced electric field poling is a phenomenon whereby a pattern of local electric field orientations can be encoded in a suitable ferroelectric material such as perovskite the resulting encoded material is conceptually similar to the pattern of magnetic field orientations within the magnetic domains of a ferromagnet and thus may be considered as a possible technology for computer storage media the encoded regions are optically active have a varying index of refraction and thus may be read out optically
the photon underproduction crisis was a cosmological deficit between observed photons and predicted photons the deficit or underproduction crisis arises from comparing observations of ultraviolet light emitted from known populations of galaxies and quasars to theoretical predictions of the amount of ultraviolet light require to simulate the observed distribution of the hydrogen gas in the local universe in a cosmological simulation the distribution of hydrogen gas was inferred using lyman alpha forest observations from hubble space telescope ’ s cosmic origins spectrograph the amount of light from galaxies and quasars can be estimated from its effect on the distribution of hydrogen and helium in the regions between galaxies highly energetic ultraviolet photons can convert electrically neutral hydrogen gas into ionized gas a team led by juna kollmeier reported an unexpected deficit of roughly 400 between ionizing light from known sources and the actual observations of intergalactic hydrogen kollmeier and her team wrote in their scientific report “ we examine the statistics of the low redshift lyman alpha forest from smoothed particle hydrodynamic simulations in light of recent improvements in the estimated evolution of the cosmic ultraviolet background uvb and recent observations from the cosmic origins spectrograph cos we find that the value of the metagalactic photoionization rate required by our simulations to match the observed properties of the low redshift lyman alpha forest is a factor of 5 larger than the value predicted by state of the art models for the evolution of this quantity ” cosmological simulations start at very high cosmological redshift z such as z 100 or larger and are evolved to z 0 according to benjamin d oppenheimer who is one of the report s coauthors “ the simulations fit the data beautifully in the early universe and they fit the local data beautifully if we ’ re allowed to assume that this extra light is really there it s possible the simulations do not reflect reality which by itself would be a surprise because intergalactic hydrogen is the component of the universe that we think we understand the best ” kollmeier and her team state that either conventional sources of ionizing photons galaxies and quasars must contribute considerably more than current observational estimates or our theoretical understanding of the low redshift universe is in need of substantial revision ” similar study led by michael shull found that the deficit is only factor 2 large and not a factor 5 as previously claimed the photon underproduction crisis is resolved by a series of recent papers khaire srianand showed that a factor 2 to 5 times large metagalactic photoionization rate can be easily obtained using updated quasar and galaxy observations recent observations of quasars indicate that the quasar contribution to ultraviolet photons is factor 2 large as compared to previous estimates the revised galaxy contribution is also factor 3 higher furthermore the kollmeier gadget 2 simulations did not include heating from agn feedback including agn feedback was shown to be an important element for heating in the low redshift igm gurvich burkhart bird 2016 this implies that the low redshift cos data can be used to calibrate agn feedback models in cosmological simulations
a photooxygenation is a light induced oxidation reaction in which molecular oxygen is incorporated into the product s initial research interest in photooxygenation reactions arose from oscar raab s observations in 1900 that the combination of light oxygen and photosensitizers is highly toxic to cells early studies of photooxygenation focused on oxidative damage to dna and amino acids but recent research has led to the application of photooxygenation in organic synthesis and photodynamic therapy photooxygenation reactions are initiated by a photosensitizer which is a molecule that enters an excited state when exposed to light of a specific wavelength e g dyes and pigments the excited sensitizer then reacts with either a substrate or ground state molecular oxygen starting a cascade of energy transfers that ultimately result in an oxygenated molecule consequently photooxygenation reactions are categorized by the type and order of these intermediates as type i type ii or type iii reactions
photoperiodism is the physiological reaction of organisms to the length of day or night it occurs in plants and animals photoperiodism can also be defined as the developmental responses of plants to the relative lengths of light and dark periods
photophobia is a symptom of abnormal intolerance to visual perception of light as a medical symptom photophobia is not a morbid fear or phobia but an experience of discomfort or pain to the eyes due to light exposure or by presence of actual physical sensitivity of the eyes though the term is sometimes additionally applied to abnormal or irrational fear of light such as heliophobia the term photophobia comes from the greek φῶς phōs meaning light and φόβος phobos meaning fear
photopsia is the presence of perceived flashes of light it is most commonly associated with posterior vitreous detachment migraine with aura migraine aura without headache retinal break or detachment occipital lobe infarction and sensory deprivation ophthalmopathic hallucinations vitreous shrinkage or liquefaction which are the most common causes of photopsia cause a pull in vitreoretinal attachments irritating the retina and causing it to discharge electrical impulses these impulses are interpreted by the brain as flashes this condition has also been identified as a common initial symptom of punctate inner choroiditis pic a rare retinal autoimmune disease believed to be caused by the immune system mistakenly attacking and destroying the retina during pregnancy new onset photopsia is concerning for severe preeclampsia photopsia can present as retinal detachment when examined by an optometrist or ophthalmologist however it can also be a sign of uveal melanoma this condition is extremely rare 5 7 per 1 million people will be affected typically fair skinned blue eyed northern europeans photopsia should be investigated immediately
the photorefractive effect is a nonlinear optical effect seen in certain crystals and other materials that respond to light by altering their refractive index the effect can be used to store temporary erasable holograms and is useful for holographic data storage it can also be used to create a phase conjugate mirror or an optical spatial soliton
photosensitive drug reaction or drug induced photosensitivity secondary to medications may cause phototoxic photoallergic and lichenoid reactions and photodistributed telangiectasias as well as pseudoporphyria drugs involved include naproxen and doxycycline
photosensitivity is the amount to which an object reacts upon receiving photons especially visible light in medicine the term is principally used for abnormal reactions of the skin and two types are distinguished photoallergy and phototoxicity the photosensitive ganglion cells in the mammalian eye are a separate class of light detecting cells from the photoreceptor cells that function in vision
photosensitivity is an abnormal skin reaction to direct sunlight exposure it is unrelated to a sunburn these reactions are due to photosensitization the accumulation of photosensitive compounds beneath the skin in some cases the photodynamic substances come from ingested plants or drugs after being metabolized or not in other cases the photodynamic substances may be produced in the body itself due to inborn errors in pigment metabolism especially those involving the heme synthesis photosensitivity reactions are usually seen in herbivorous or omnivorous animals though such reactions are not uncommon among carnivores
photosensitivity with hiv infection is a skin condition resembling polymorphous light eruption actinic prurigo or chronic actinic dermatitis seen in about 5 of hiv infected people
photothermal effect is a phenomenon associated with electromagnetic radiation it is produced by the photoexcitation of material resulting in the production of thermal energy heat it is sometimes used during treatment of blood vessel lesions laser resurfacing laser hair removal and laser surgery
phototoxic tar dermatitis results from coal tar creosote crude coal tar or pitch in conjunction with sunlight exposure which induces a sunburn reaction associated with severe burning sensation
phototropism is the growth of an organism which responds to a light stimulus it is most often observed in plants but can also occur in other organisms such as fungi the cells on the plant that are farthest from the light have a chemical called auxin that reacts when phototropism occurs this causes the plant to have elongated cells on the farthest side from the light phototropism is one of the many plant tropisms or movements which respond to external stimuli growth towards a light source is called positive phototropism while growth away from light is called negative phototropism most plant shoots exhibit positive phototropism and rearrange their chloroplasts in the leaves to maximize photosynthetic energy and promote growth roots usually exhibit negative phototropism although gravitropism may play a larger role in root behavior and growth some vine shoot tips exhibit negative phototropism which allows them to grow towards dark solid objects and climb them the combination of phototropism and gravitropism allow plants to grow in the correct direction
phthisis bulbi is a shrunken non functional eye it may result from severe eye disease inflammation injury or it may represent a complication of eye surgery treatment options include insertion of a prosthesis which may be preceded by enucleation of the eye
phyletic dwarfism is the decrease in average size of animals of a species there are a few circumstances that often lead to species doing this lack of predators of smaller creatures can allow smaller members of a species to survive the lack of resources to sustain a large population of larger animals can pick off the largest specimens available resources being more beneficial for smaller creatures can also do so these circumstances are common on islands making insular dwarfism the most common form of phyletic dwarfism examples of this are the channel island fox extinct dwarf elephants of crete and brookesia micra a minuscule chameleon from madagascar it is possible that phyletic dwarfism may have also helped into bringing us the birds we see today from the giant dinosaurs we read about as kids
phyllodes tumors from greek phullon leaf also cystosarcoma phyllodes cystosarcoma phylloides and phylloides tumor are typically large fast growing masses that form from the periductal stromal cells of the breast they account for less than 1 of all breast neoplasms
phylloid hypomelanosis is a cutaneous condition a syndrome occurring in patients with mosaic trisomy 13 or translocation trisomy 13
physical abuse can be defined as any intentional act causing injury or trauma to another person by way of bodily contact in most cases children are the victims of physical abuse but adults can also be victims as in cases of domestic violence or workplace aggression alternative terms sometimes used include physical assault or physical violence and may also include sexual abuse physical abuse may involve more than one abuser and more than one victim
physical force irish republicanism is the recurring appearance of a non parliamentary violent insurrection in ireland between 1798 and the present it is often described as a rival to parliamentary nationalism which for most of the period drew the predominant amount of support from irish nationalists
phytophotodermatitis also known as lime disease not to be confused with lyme disease berloque dermatitis or margarita photodermatitis is a chemical reaction which makes skin hypersensitive to ultraviolet light it is frequently mistaken for hereditary conditions such as atopic dermatitis or chemical burns but it is caused by contact with the photosensitizing compounds found naturally in some plants and vegetables like parsnips citrus fruits and more symptoms include burning itching stinging and large blisters that slowly accumulate over time
phytophthora rubi is the principal cause of root rot in red raspberry originally classified as a variant of p fragariae some now consider it a distinct species t veld 2007 this organism has been isolated from raspberries in europe north america wilcox scott et al 1993 chile wilcox and latorre 2002 and other many countries around the world it is best controlled through a combination of good management practices and use of resistant varieties it is a significant cause of crop loss in poor draining soils
phytotoxicity is a toxic effect by a compound on plant growth such damage may be caused by a wide variety of compounds including trace metals salinity pesticides phytotoxins or allelochemicals
piblokto also known as pibloktoq and arctic hysteria is a condition most commonly appearing in inughuit societies living within the arctic circle piblokto is a culture specific hysterical reaction in inuit especially women who may perform irrational or dangerous acts followed by amnesia for the event piblokto may be linked to repression of the personality of inuit women the condition appears most commonly in winter it is considered to be a form of a culture bound syndrome although more recent studies see skepticism section question whether it exists at all piblokto is also part of the glossary of cultural bound syndromes found in the diagnostic and statistical manual of mental disorders dsm iv
pica is characterized by an appetite for substances that are largely non nutritive such as ice pagophagia hair trichophagia paper papyrophagia drywall or paint metal metallophagia stones lithophagia or earth geophagia glass hyalophagia or feces coprophagia and chalk according to dsm iv diagnostic and statistical manual of mental disorders 4 th edition criteria for these actions to be considered pica they must persist for more than one month at an age where eating such objects is considered developmentally inappropriate not part of culturally sanctioned practice and sufficiently severe to warrant clinical attention it can lead to intoxication in children which can result in an impairment in both physical and mental development in addition it can also lead to surgical emergencies due to an intestinal obstruction as well as more subtle symptoms such as nutritional deficiencies and parasitosis pica has been linked to other mental and emotional disorders stressors such as emotional trauma maternal deprivation family issues parental neglect pregnancy and a disorganized family structure are strongly linked to pica as a form of comfort pica is most commonly seen in pregnant women small children and those with developmental disabilities such as autism children eating painted plaster containing lead may suffer brain damage from lead poisoning there is a similar risk from eating soil near roads that existed before tetraethyllead in petrol was phased out in some countries or before people stopped using contaminated oil containing toxic pcbs or dioxin to settle dust in addition to poisoning there is also a much greater risk of gastro intestinal obstruction or tearing in the stomach another risk of eating soil is the ingestion of animal feces and accompanying parasites pica can also be found in other animals and is commonly found in dogs
the picardy sweat was an infectious disease of unknown etiology it appeared in the northern french province of picardy in 1718 between 1718 and 1874 194 epidemics of the picardy sweat were recorded the last extensive outbreak was in 1906 which a french commission attributed to fleas from field mice a subsequent case was diagnosed in 1918 in a soldier in picardy it was named suette des picards in france and picard scher schweiß or picard sches schweissfieber in germany there were several longer descriptions of the disease the disease was similar to the english sweat but differed in some symptoms and in its course and mortality rate some of the symptoms were high fever rash and bleeding from the nose many victims died within two days
pick s disease a type of frontotemporal dementia is a rare neurodegenerative disease that causes progressive destruction of nerve cells in the brain symptoms include dementia and loss of language aphasia while some of the symptoms can initially be alleviated the disease progresses and patients often die within two to ten years a defining characteristic of the disease is build up of tau proteins in neurons accumulating into silver staining spherical aggregations known as pick bodies while the term pick s disease was once used to represent a class of clinical syndromes with symptoms attributable to frontal and temporal lobe dysfunction it is now used among professionals to mean a specific pathology that is one of the causes of frontotemporal lobar degeneration some people use the term pick s disease to mean the more general clinical syndrome of frontotemporal lobar degeneration but this has previously led to confusion among professionals and patients and so its use should be restricted to the specific pathological subtype described below it is also known as pick disease and pid not to be confused with pelvic inflammatory disease pid or parkinson s disease pd
pickardt syndrome also pickardt s syndrome or pickardt – fahlbusch syndrome denotes a rare form of tertiary hypothyroidism that is caused by interruption of the portal veins connecting hypothalamus and pituitary it was characterized in 1972 and 1973
picokijada pitsɔkijada is a traditional cultural tourist manifestation that has been held since 1968 at the end of june in the podravina town of đurđevac in croatia the event lasts three days and the main event is legenda o picokima lɛɡɛŋda ɔ pitsɔkima legend of the rooster a remembrance of the defense of the people of the town đurđevac from the turks under the title legenda o picokima is set in the time of the attack of the turkish army on the old town đurđevac as ulama beg encountered unexpected resistance and failed to defeat the defenders of đurđevac with an army he decided on a long siege with the goal of starving the army and the people that hid inside the legend says that in the surrounded fortress the food had vanished all that was left was one small rooster picok pitsɔk this could not feed the people so an old woman suggested to the captain of the town that the rooster should be put in a cannon and shot into the turkish camp thinking that there was plenty of food in the fortress ulama beg ended the siege and left the battlefield as a curse ulama beg calls the people of đurđevac picoki pitsɔki or roosters at the end of this scene he says in croatian ” a vi tamo pernati junaci što picekima bojeve bijete ime picoka dovijeka nosili picokima vas djeca zvala a unuci vaši ostat će picoki ” english ” and you there feathered heroes that fight battles with roosters shall always carry the name roosters your children shall call you roosters and your grandchildren will stay roosters ” the display of legenda o picokima is under the protection of the republic of croatia ministry of culture as the first intangible cultural heritage of republic of croatia as well as being the biggest tourist attraction of podravina
the pictet – spengler reaction is a chemical reaction in which a β arylethylamine such as tryptamine undergoes ring closure after condensation with an aldehyde or ketone usually an acidic catalyst is employed and the reaction mixture heated but some reactive compounds give good yields even under physiological conditions the pictet – spengler reaction can be considered a special case of the mannich reaction the pictet – spengler reaction the reaction was discovered in 1911 by amé pictet and theodor spengler it has remained an important reaction in the fields of alkaloid and pharmaceutical synthesis the pictet – spengler reaction product of tryptophan and aldoses can be identified in foodstuffs such as soy sauce and ketchup nucleophilic aromatic rings such as indole or pyrrole give products with good yields and mild conditions while less nucleophilic aromatic rings such as benzene give poor yields despite high temperatures and strong acid the original pictet – spengler reaction was the reaction of β phenethylamine with the dimethyl acetal of formaldehyde and hydrochloric acid forming a tetrahydroisoquinoline like the mannich reaction aldehydes give good yields while ketones tend to give lower conversion the pictet – spengler reaction has been applied to solid phase combinatorial chemistry with great success an analogous reaction with an aryl β ethanol is called oxa pictet – spengler reaction
for televisions the picture line up generation equipment pluge or pluge is the greyscale test patterns used in order to adjust the black level and contrast of the picture monitor various pluge patterns can be generated the most common consisting of three vertical bars of super black normal black and near black and two rectangles of mid gray and white sometimes these are measured in ire these three pluge pulses are included in the smpte color bars at the bottom and near the right used for ntsc pal and sécam
piebaldism is a rare autosomal dominant disorder of melanocyte development common characteristics include a congenital white forelock scattered normal pigmented and hypopigmented macules and a triangular shaped depigmented patch on the forehead there is nevertheless great variation in the degree and pattern of presentation even within affected families in some cases piebaldism occurs together with severe developmental problems as in waardenburg syndrome and hirschsprung s disease it has been documented to occur in all races early photographers captured many images of african piebalds used as a form of amusement and george catlin is believed to have painted several portraits of native americans of the mandan tribe who were affected by piebaldism piebaldism is found in nearly every species of mammal it is very common in mice rabbits dogs sheep deer cattle and horses — where selective breeding has increased the incidence of the mutation but occurs among chimpanzees and other primates only as rarely as among humans piebaldism is completely unrelated to acquired or infectious conditions such as vitiligo or poliosis pie is a word for multi colored and bald is related to a root word for skin although piebaldism may visually appear to be partial albinism it is a fundamentally different condition the vision problems associated with albinism are not usually present as eye pigmentation is normal piebaldism differs from albinism in that the affected cells maintain the ability to produce pigment but have that specific function turned off in albinism the cells lack the ability to produce pigment altogether human piebaldism has been observed to be associated with a very wide range and varying degrees of endocrine disorders and is occasionally found together with heterochromia of the irises congenital deafness or incomplete gastrointestinal tract development possibly all with the common cause of premature cutting off of human fetal growth hormone during gestation piebaldism is a kind of neurocristopathy involving defects of various neural crest cell lineages that include melanocytes but also involving many other tissues derived from the neural crest oncogenic factors including mistranscription are hypothesized to be related to the degree of phenotypic variation among affected individuals this is an autosomal dominant hereditary condition which tends to produce high rates of inheritance and long chains of generational transmission all who inherit the gene have at some time in life evidence of piebald hypopigmentation of the hair or skin most likely both historically persons with extensive piebaldism have experienced abuse of the sort still suffered in the present by albinos especially in africa this has ranged from display of unclothed african piebalds in freak shows and post cards of the early twentieth century to the forcing of piebalds as in the case of albinos to work long hours exposed to the sun producing high rates of lethal skin cancers to the use of piebald humans including children in risky medical experiments the national organization of albinism and hypopigmentation as well as organizations such as under the same sun work to promote awareness of all forms of cutaneous variation and their medical implications and to highlight human rights issues especially the plight of albinos subject to extreme persecution in parts of africa piebaldism may be associated with the genes kit or snai 2
in mathematics a piecewise defined function also called a piecewise function or a hybrid function is a function which is defined by multiple sub functions each sub function applying to a certain interval of the main function s domain a sub domain piecewise is actually a way of expressing the function rather than a characteristic of the function itself but with additional qualification it can describe the nature of the function for example a piecewise polynomial function is a function that is a polynomial on each of its sub domains but possibly a different one on each the word piecewise is also used to describe any property of a piecewise defined function that holds for each piece but not necessarily hold for the whole domain of the function a function is piecewise differentiable or piecewise continuously differentiable if each piece is differentiable throughout its subdomain even though the whole function may not be differentiable at the points between the pieces in convex analysis the notion of a derivative may be replaced by that of the subderivative for piecewise functions although the pieces in a piecewise definition need not be intervals a function is not called piecewise linear or piecewise continuous or piecewise differentiable unless the pieces are intervals
in mathematics a piecewise linear function is a real valued function defined on the real numbers or a segment thereof whose graph is composed of straight line sections it is a piecewise defined function each of whose pieces is an affine function usually – but not always – the function is assumed to be continuous in that case its graph is a polygonal curve
in linguistics pied piping is a phenomenon of syntax whereby a given focused expression takes an entire encompassing phrase with it when it is moved the term itself is due to john robert ross it is a reference to the pied piper of hamelin the figure of fairy tales who lured rats and children by playing his flute pied piping is an aspect of discontinuities in syntax having to do with the constituents that can and cannot be discontinuous while pied piping is most visible in cases of wh fronting of information questions and relative clauses it is not limited to wh fronting but rather it can be construed as occurring with most any type of discontinuity extraposition scrambling topicalization most if not all languages that allow discontinuities employ pied piping to some extent although there are major differences across languages in this area some languages employing pied piping much more than others
pied piping with inversion is a special word order phenomenon found in some languages for example languages in the mesoamerican linguistic area
piedra also known as trichosporosis is a hair disease caused by a fungus types include white piedra black piedra
pierre robin syndrome abbreviated to prs and also known as pierre robin sequence pierre robin malformation pierre robin anomaly or pierre robin anomalad is a congenital condition of facial abnormalities in humans prs is a sequence i e a chain of certain developmental malformations one entailing the next the three main features are cleft palate retrognathia abnormal positioning of the jaw or maxilla and glossoptosis airway obstruction caused by backwards displacement of the tongue base a genetic cause to prs was recently identified pierre robin sequence may be caused by genetic anomalies at chromosomes 2 11 or 17
piezomagnetism is a phenomenon observed in some antiferromagnetic crystals it is characterised by a linear coupling between the system s magnetic polarisation and mechanical strain in a piezomagnetic one may induce a spontaneous magnetic moment by applying physical stress or a physical deformation by applying a magnetic field piezomagnetism differs from the related property of magnetostriction if an applied magnetic field is reversed in direction the strain produced changes signs additionally a non zero piezomagnetic moment can be produced by mechanical strain alone at zero field this is not true of magnetostriction according to ieee piezomagnetism is the linear magnetomechanical effect analogous to the linear electromechanical effect of piezoelectricity similarly magnetostriction and electrostriction are analogous second order effects these higher order effects can be represented as effectively first order when variations in the system parameters are small compared with the initial values of the parameters the piezomagnetic effect is made possible by an absence of certain symmetry elements in a crystal structure specifically symmetry under time reversal forbids the property the first experimental observation of piezomagnetism was made in 1960 in the fluorides of cobalt and manganese
piezo phototronic effect is a three way coupling effect of piezoelectric semiconductor and photonic properties in non central symmetric semiconductor materials using the piezoelectric potential piezopotential that is generated by applying a strain to a semiconductor with piezoelectricity to control the carrier generation transport separation and or recombination at metal semiconductor junction or p n junction for improving the performance of optoelectronic devices such as photodetector solar cell and light emitting diode prof zhong lin wang at georgia institute of technology proposed the fundamental principle of this effect in 2010
pigeon fever also dry land distemper in horses or equine distemper is a disease that causes abscesses in horses sheep and cattle pigeon fever is not zoonotic meaning it is not transmitted to human from animal an example of a zoonotic disease would be rabies pigeon fever is sometimes confused for strangles another infection that causes abscesses pigeon fever is a bacterium that lives in the ground and transmitted to horses via the air direct contact or cuts and or open abrasions the name pigeon fever comes from the symptoms of the disease commonly the horse will get swelling in the chest area puffed out chest like a pigeon and it causes fever and sweats some think it is caused or carried by pigeons that is a misunderstanding and pigeons have nothing to do with the disease flies are believed to be the main carries that spread the infection which is why quarantine of infected animals is ineffective this bacterial infection is caused by corynebacterium pseudotuberculosis and characterized by deep intramuscular and sometimes internal abscesses in horses the reason it is called dry land distemper is it is common in dry areas like california arizona new mexico and other areas
pigeon pox is a viral disease to which pigeons are susceptible there is a live viral vaccine available atcvet code qi 01 ed 01 who pigeon pox is caused by a virus that is spread by mosquitoes and dirty water but not in droppings
pigeon toe also known as metatarsus varus metatarsus adductus in toe gait intoeing or false clubfoot is a condition which causes the toes to point inward when walking it is most common in infants and children under two years of age and when not the result of simple muscle weakness normally arises from underlying conditions such as a twisted shin bone or an excessive anteversion femoral head is more than 15 ° from the angle of torsion resulting in the twisting of the thigh bone when the front part of a person s foot is turned in severe cases are considered a form of clubfoot
pigmentatio reticularis faciei et colli is a cutaneous condition characterized by a disturbance of human pigmentation
pigmentation disorders are disturbances of human skin color either loss or reduction which may be related to loss of melanocytes or the inability of melanocytes to produce melanin or transport melanosomes correctly
a pigmented dermatofibroma is a skin condition characterized by a pigmented lesion that must be distinguished from melanoma they have borders that are difficult to see and a firm texture that dimples upon lateral compression they are usually small less than 6 millimeters in diameter and on the extremities q
pigmented hairy epidermal nevus syndrome is a cutaneous condition characterized by a becker nevus ipsilateral hypoplasia of the breast and skeletal defects such as scoliosis
pigmented purpuric dermatosis also known as progressive pigmentary dermatosis purpura pigmentosa chronica pigmentary purpuric eruptions or progressive pigmenting purpura or schamberg s disease refers to one of the three major classes of skin conditions characterized by purpuric skin eruptions pigmented purpuric dermatosis are distinguished from other purpura by size 0 3 – 1 cm and are most often seen in the lower extremities pigmentary purpuric eruptions may present with one of several clinical patterns there may be overlapping characteristics among pigmented purpuric dermatosis and between their signs and those of other purpuric eruptions examples of the pigmented purpuric dermatosis group include schamberg s disease majocchi s disease purpura annularis telangiectodes gougerot blum syndrome pigmented purpuric lichenoid dermatitis ducas and kapetanakis pigmented purpura lichen aureus although vascular damage may be present it is insufficient for these conditions to be considered forms of vasculitis
a pigmented spindle cell nevus also known as a pigmented spindle cell tumor of reed and pigmented variant of spitz nevus is a cutaneous condition characterized by a dark brown to black macule or papule usually less than 6 mm it was characterized in 1975
pigmented villonodular synovitis pvns is a joint disease characterized by inflammation and overgrowth of the joint lining it usually affects the hip or knee it can also occur in the shoulder ankle elbow hand or foot in pvns the lining of the joint called the synovium becomes swollen and grows this growth harms the bone next to the joint the lining also makes extra fluid that can cause swelling and make movement painful pvns is idiopathic it doesn t seem to run in families or be caused by certain jobs or activities surgery can help but even with treatment pvns comes back about half the time if the pain remains then radiation therapy may help in the worst cases the joint must be replaced
pigmented warts are a cutaneous condition commonly reported in japan most often occurring on the hands or feet
a pilar sheath acanthoma is a cutaneous condition most often found on the face particularly above the upper lip in adults
pili annulati also known as ringed hair is a genetic trait in which the hair seems banded by alternating segments of light and dark color when seen in reflected light
pili bifurcati is characterized by bifurcation found in short segments along the shafts of several hairs with each branch of the bifurcation being covered with its own cuticle
electrolysis will permanently remove pili multigemini depilating laser treatment has been suggested to improve symptomatic pili multigemini
pili torti also known as twisted hairs is characterized by short and brittle hairs that appear flattened and twisted when viewed through a microscope this phenotype is noted in menkes disease
pill dispensers are items which release medication at specified times their purpose is to help senior citizens and other people who may suffer from impaired ability to adhere to their prescribed medication regime pill dispensers are commonly used to serve medical purposes but it is also user to help individuals be that the elderly or chronically ill take their prescription medication otc medication or daily supplements at a given date and time there are telehealth products in the health care industry such as automated or electronic pill boxes that function to alert the patients when it is time to take their medications
a pillar of cloud hebrew עמוד ענן was one of the manifestations of the presence of the god of israel in the torah the five books of moses which appear at the beginning of the old testament bible according to exodus the pillar of cloud guided the israelites by day during the exodus from egypt circa the 18 th dynasty see dating of the exodus the pillar of cloud is traditionally paired with the manifestation of the divine presence by night as the pillar of fire which provided light this was so they could travel by day or night
a pillar of fire was one of the manifestations of the presence of the god of israel in the torah the five books of moses which appear at the beginning of the old testament bible according to exodus the pillar of fire provided light so that the israelites could travel by night during the exodus from egypt claimed to be the 18 th dynasty see dating of the exodus the pillar of fire is traditionally paired with the manifestation of the divine presence by day as the pillar of cloud this was so they could travel by day or night
a pillow fight flash mob is a social phenomenon of flash mobbing and shares many characteristics of a culture jam the flash mob version of massive pillow fights is distinguished by the fact that nearly all of the promotion is internet based these events occur around the world some taking the name pillow fight club a reference to fight club by chuck palahniuk in which anyone could join and fight as long as they fought by the rules both the london and vancouver pillow fight club s rules reflect that described in the book and feature film the trend owes much to uses of modern communications technologies including decentralised personal networking known as smartmobbing word of the events spreads primarily via digital means usually on the internet via email chat rooms and text messaging which result in seemingly spontaneous mass gatherings pillows are sometimes hidden and at the exact pre arranged time or the sound of a whistle the pillow fighters pull out their pillows and commence pillow fighting the pillow fights can last from a few minutes to several hours
pilocytic astrocytoma or juvenile pilocytic astrocytoma or cystic cerebellar astrocytoma and its variant juvenile pilomyxoid astrocytoma is a brain tumor that occurs more often in children and young adults in the first 20 years of life they usually arise in the cerebellum near the brainstem in the hypothalamic region or the optic chiasm but they may occur in any area where astrocytes are present including the cerebral hemispheres and the spinal cord these tumors are usually slow growing and benign the neoplasms are associated with the formation of a single or multiple cyst s and can become very large pilocytic astrocytomas are often cystic and if solid tend to be well circumscribed it is characteristically easily seen on ct scans and mri juvenile pilocytic astrocytoma is associated with neurofibromatosis type 1 nf 1 and optic gliomas are among the most frequently encountered tumors in patients with this disorder the majority of pilocytic astrocytomas have a unique kiaa 1549 braf fusion gene
piloleiomyomas are a cutaneous condition that present as dermal reddish brown pink or skin colored papules or nodules that can be solitary or multiple
pilomatricoma also known as a calcifying epithelioma of malherbe malherbe calcifying epithelioma and pilomatrixoma is a benign skin tumor derived from the hair matrix these neoplasms are relatively uncommon and typically occur on the scalp face and upper extremities clinically pilomatricomas present as a subcutaneous nodule or cyst with unremarkable overlying epidermis that can range in size from 0 5 3 0 cm but the largest reported cases was 24 cm
a pilon fracture also called a plafond fracture is a fracture of the distal part of the tibia involving its articular surface at the ankle joint pilon fractures are caused by rotational or axial forces mostly as a result of falls from a height or motor vehicle accidents pilon fractures are rare comprising 3 to 10 percent of all fractures of the tibia and 1 percent of all lower extremity fractures but they involve a large part of the weight bearing surface of the tibia in the ankle joint because of this they may be difficult to fixate and are historically associated with high rates of complications and poor outcome pilon is the french word for pestle and was introduced into orthopedic literature in 1911 by pioneer french radiologist étienne destot
pilonidal cyst also referred to as a pilonidal abscess pilonidal sinus or sacrococcygeal fistula is a cyst or abscess near or on the natal cleft of the buttocks that often contains hair and skin debris
pilotto syndrome is a rare syndrome which affects the face heart and back the syndrome can cause a cleft lip and palate scoliosis and mental retardation the office of rare diseases and national institutes of health have classified this syndrome as affecting less than 200 000 people in the united states
a pimple zit or spot is a kind of comedo and one of the many results of excess oil getting trapped in the pores some of the varieties are pustules or papules pimples can be treated by various acne medications prescribed by a physician or purchased at a pharmacy with a wide variety of treatments
a pin or fall is a victory condition in various forms of wrestling that is met by holding an opponent s shoulders or scapulae shoulder blades on the wrestling mat for a prescribed period of time this article deals with the pin as it is defined in amateur wrestling in amateur wrestling a pin ends the match regardless of when it occurs situations which are almost pins but for whatever reason do not meet the criteria — for example have only one shoulder down or have the defending wrestler blocked in a neck bridge — are rewarded with exposure points in collegiate wrestling known as near fall points or back points in order to encourage wrestlers to take risks to try to pin their opponents under the 2004 – 05 changes to the united world wrestling rules amateur wrestling moved to a round based system in which each period is conducted as a separate match with a winner declared the pin is an exception — it ends a match outright unlike the period only victories awarded by technical fall or decision on points in this way the fall is analogous to a knockout in boxing
a pinfall is a victory condition in various forms of professional wrestling that is met by holding pinning an opponent s shoulders on the wrestling mat usually till the referee counts to three in professional wrestling a pinfall is a common method of winning a match the purpose of a pinning maneuver is to hold the opponent s shoulders against the mat for a count of three the count is broken a near fall if the opponent manages to raise one or both of his shoulders off of the mat commonly by kicking out throwing their legs up to cause their shoulders to rise from the mat in some positions a wrestler may bridge arching their back so that only their feet and the top of their head are touching the ground to put more of their weight on the pinned opponent or to prop themselves up from being pinned sometimes an attacking wrestler may illegally hook the opponent s tights for extra leverage another popular illegal tactic of heel wrestlers is to attempt a pin close to the ring ropes so they can prop their legs or on rare occasions arms up on the ropes to gain additional leverage putting more weight on the opponent on the other hand a pin fall attempt cannot occur in the first place when one rolls out of the ring if falls do not count anywhere or if the opponent lies on his her stomach upon impact so it would take extra effort to roll the opponent over even when he she is knocked out cold due to the body being effectively a dead weight
pinstripes are a pattern of very thin stripes of any color running in parallel often found in cloth the pinstriped suit has become associated with conservative business attire although many designers now produce the fashionable pinstripe patterns for fashion conscious consumers fine lines for vehicles are also called pinstripes although found mostly in men s suits any type of fabric can be pinstriped the chicago cubs baseball uniforms have had pinstripes since 1907 and they are recognized as the first major league baseball team to incorporate pinstriping into a baseball uniform many other former and current major league baseball teams — including the minnesota twins montreal expos colorado rockies new york mets new york yankees chicago white sox and philadelphia phillies — later adopted pinstripes on their own uniforms this was later carried over into the nba with teams like the chicago bulls charlotte hornets and orlando magic incorporating pinstripes into their uniforms
the first step in the reaction mechanism is one electron reduction of the carbonyl group by a reducing agent such as magnesium to a ketyl radical anion species two ketyl groups react in a coupling reaction yielding a vicinal diol with both hydroxyl groups deprotonated addition of water or another proton donor gives the diol with magnesium as an electron donor the initial reaction product is a 5 membered cyclic compound with the two oxygen atoms coordinated to the oxidized mg 2 ion this complex is also broken up by addition of water with formation of magnesium hydroxide the pinacol coupling can be followed up by a pinacol rearrangement a related reaction is the mcmurry reaction which uses titanium iii chloride or titanium iv chloride in conjunction with a reducing agent for the formation of the metal diol complex and which takes place with an additional deoxygenation reaction step in order to provide an alkene product
pincer nails also known as omega nails and trumpet nails are a toenail disorder in which the lateral edges of the nail slowly approach one another compressing the nailbed and underlying dermis it occurs less often in the fingernails and there usually are no symptoms hereditary pincer nails have been described although the genes or mutations causing the hereditary form seem to be unknown
a pinch in cooking pn is an amount of an ingredient typically salt sugar or spice traditionally it was defined as an amount that can be taken between the thumb and forefinger historically the pinch was more precisely defined by some u s cookbooks as approximately 1 ⁄ 8 teaspoon in the early 2000 s some companies began selling measuring spoons that defined or redefined a dash as 1 ⁄ 8 teaspoon a pinch as 1 ⁄ 16 teaspoon and a smidgen as 1 ⁄ 32 teaspoon based on these spoons there are two pinches in a dash and two smidgens in a pinch one pinch of fine salt is approximately 1 ⁄ 4 gram 20 – 24 pinches per teaspoon while one pinch of sugar is 1 ⁄ 2 – 1 ⁄ 3 1 ⁄ 6 gram
pinch marks are a cutaneous condition and when on the ears or in the genital region of male children may be suggestive of child abuse
pine pine gall rust also known as western gall rust is a fungal disease of pine trees this plant disease is caused by endocronartium harknessii asexual name is peridermium harknessii an autoecious endocyclic rust fungus that grows in the vascular cambium of the host pine pine gall rust is found on pine trees pinus spp with two or three needles such as ponderosa pine jack pine and scots pine the disease is very similar to pine oak gall rust but its second host is another pinus species the fungal infection results in gall formation on branches or trunks of infected hosts gall formation is typically not detrimental to old trees but has been known to kill younger less stable saplings galls can vary from small growths on branch extremities to grapefruit sized galls on trunks
pineoblastoma also pinealoblastoma is a malignant tumor of the pineal gland a pineoblastoma is a supratentorial midline primitive neuroectodermal tumor pineoblastoma may occur in patients with hereditary uni or bilateral retinoblastoma when retinoblastoma patients present with pineoblastoma this is characterized as trilateral retinoblastoma up to 5 of patients with hereditary retinoblastoma are at risk of developing trilateral retinoblastoma prognosis of patients with trilateral retinoblastoma is dismal only a few patients have survived more than 5 years after diagnosis all survivors were diagnosed with small tumors in a subclinical stage recent advances in high dose chemotherapy treatment regimens and early detection have improved survival of patients with trilateral retinoblastoma to up to 50
pinealoma is a tumor of the pineal gland
pineapple black rot also known as butt rot base rot or white blister is a disease caused by ceratocystis paradoxa dade moreau anamorph thielaviopsis paradoxa de seyenes höhnel is the most common and well known post harvest disease of the pineapple fruit which is responsible for serious losses in the fresh pineapple fruit world industry the disease is widespread and one of the common and destructive pineapple diseases in the world it occurs in the field and normally remains quiescent or especially appears during harvest and marketing the disease is a universal fresh fruit problem but normally not a problem with processed fruit because times from harvest to processing are too short for infection although it occurs in the field when fruit is injured or over ripped in a poor drained soil
pineocytoma also known as a pinealocytoma is a benign slowly growing tumor of the pineal gland unlike the similar condition pineal gland cyst it is uncommon
a pinguecula is a common type of conjunctival degeneration in the eye
pink algae is a growth of pink slimey bacterial matter which can sometimes occur in pools and sometimes in laboratory tubings the title is a misnomer because as noted before pink algae is actually caused by a bacterium in the genus methylobacterium the color of the bacterial growth comes from pigments within its cells the slime formed around the bacteria provides it with a relatively high level of protection from external threats like other species in its genus pink algae is a methane consuming bacterium it has an affinity for the matrix of pvc plastics and will attach itself to both the inside and the outside of pvc materials inside of the pool pink algae infestation in a pool often occurs alongside an infestation of white water mold
pink rot is a fungal disease of various plants caused by various organisms phytophthora erythroseptica – pink rot of potatoes carrots tubers trichothecium roseum – pink rot of apples grapes avocadoes peaches nectarines fruit nalanthamala vermoeseni or gliocladium vermoeseni – pink rot of date palm inflorescence disambig
the pinnaroo line serviced the agricultural districts of the mallee for the freight of grain although there were periods of passenger travel on the line in previous years the last passenger service between ouyen and pinnaroo being in 1968 the railway line was the means to open up the agricultural lands with the supply of goods and services from rural centres sustaining the remote area it was completed from ouyen to murrayville in 1912 and extended to pinnaroo in 1915 in 1996 the line stopped at panitya due to gauge conversion at the state border it was booked out of service on 4 october 2007
the pinner reaction after adolf pinner is an organic reaction of a nitrile with an alcohol using an acid catalyst for instance sulfuric acid the product formed is the mineral acid salt of an imino ester or an alkyl imidate which sometimes is called a pinner salt the reaction is a sequence of nucleophilic additions these salts can react with an excess of alcohol to form the orthoester rc or 3 with ammonia or an amine to form an amidine or with water to form an ester file reaction pinner 2 png it should be appreciated that the pinner reaction refers specifically to an acid catalyzed process but that similar results can often be achieved using base catalysis the two approaches can be complementary with nitriles which are unreactive under acid conditions often giving better results in the presence of base and vice versa the determining factor is typically how electron rich or poor the nitrile is for example an electron poor nitrile is a good electrophile readily susceptible to attack from alkoxides etc but a poor nucleophile difficult to protonate and would therefore be expected to react more readily under basic rather than acidic conditions
the pinnick oxidation is an organic reaction by which aldehydes can be oxidized into their corresponding carboxylic acids using sodium chlorite naclo 2 under mild acidic conditions it was originally developed by lindgren and nilsson the typical reaction conditions used today were developed by g a kraus h w pinnick later demonstrated that these conditions could be applied to oxidize α β unsaturated aldehydes there exist many different reactions to oxidize aldehydes but only a few are amenable to a broad range of functional groups the pinnick oxidation has proven to be both tolerant of sensitive functionalities and capable of reacting with sterically hindered groups this reaction is especially useful for oxidizing α β unsaturated aldehydes and another one of its advantages is its relatively low cost pinnickoxidationreaction
pinta also known as azul carate empeines lota mal del pinto and tina is a human skin disease endemic to mexico central america and south america caused by infection with a spirochete treponema pallidum carateum which is morphologically and serologically indistinguishable from the organism that causes syphilis
pinworm infection also known as enterobiasis is a human parasitic disease caused by the pinworm the most common symptom is itching in the anal area this can make sleeping difficult the period of time from swallowing eggs to the appearance of new eggs around the anus is 4 to 8 weeks some people who are infected do not have symptoms the disease is spread between people by pinworm eggs the eggs initially occur around the anus and can survive for up to three weeks in the environment they may be swallowed following contamination of the hands food or other articles those at risk are those who go to school are institutionalized or take care of people who are infected other animals do not spread the disease diagnosis is by seeing the worms which are about one centimeter or the eggs under a microscope treatment is typically with two doses of the medications mebendazole pyrantel pamoate or albendazole two weeks apart everyone who lives with or takes care of an infected person should be treated at the same time washing personal items in hot water after each dose of medication is recommended good handwashing daily bathing in the morning and daily changing of underwear can help prevent reinfection pinworm infections commonly occur in all parts of the world it is most common worm infection in the developed world school aged children are the most commonly infected in the united states about 20 of people at one point in time develop pinworm infection rates among high risk groups may be as high as 50 it is not considered a serious disease pinworms are believed to have affected humans throughout history
pipecolic acidemia also called hyperpipecolic acidemia or hyperpipecolatemia is a very rare autosomal recessive metabolic disorder that is caused by a peroxisomal defect pipecolic acidemia can also be an associated component of refsum disease with increased pipecolic acidemia rdpa as well as other peroxisomal disorders including both infantile and adult refsum disease and zellweger syndrome
piracy was a phenomenon that was not limited to the caribbean region golden age pirates roamed off the coast of north america africa and the caribbean
piriformis syndrome is a neuromuscular disorder that occurs when the sciatic nerve is compressed or otherwise irritated by the piriformis muscle causing pain tingling and numbness in the buttocks and along the path of the sciatic nerve descending the lower thigh and into the leg diagnosis is often difficult due to few validated and standardized diagnostic tests but two tests have been well described and clinically validated one is electrophysiological called the fair test which measures delay in sciatic nerve conductions when the piriformis muscle is stretched against it the other is magnetic resonance neurography a type of mri that highlights inflammation and the nerves themselves some say that the most important criterion is the exclusion of sciatica resulting from compression irritation of spinal nerve roots as by a herniated disc however compression may be present but not causal in the setting of sciatica due to piriformis syndrome the syndrome may be due to anatomical variations in the muscle nerve relationship or from overuse or strain uncontrolled studies have suggested theories about the disorder however a large scale formal prospective outcome trial found that the weight of the evidence based medicine is that piriformis syndrome should be considered as a possible diagnosis when sciatica occurs without a clear spinal cause the need for controlled studies is supported by studies of spinal disc disease that show a high frequency of abnormal discs in asymptomatic patients
in linguistics speech synthesis and music the pitch contour of a sound is a function or curve that tracks the perceived pitch of the sound over time pitch contour may include multiple sounds utilizing many pitches and can relate to frequency function at one point in time to the frequency function at a later point it is fundamental to the linguistic concept of tone where the pitch or change in pitch of a speech unit over time affects the semantic meaning of a sound it also indicates intonation in pitch accent languages one of the primary challenges in speech synthesis technology particularly for western languages is to create a natural sounding pitch contour for the utterance as a whole unnatural pitch contours result in synthesis that sounds lifeless or emotionless to human listeners a feature that has become a stereotype of speech synthesis in popular culture in music the pitch contour focuses on the relative change in pitch over time of a primary sequence of played notes the same contour can be transposed without losing its essential relative qualities such as sudden changes in pitch or a pitch that rises or falls over time pure tones have a clear pitch but complex sounds such as speech and music typically have intense peaks at many different frequencies nevertheless by establishing a fixed reference point in the frequency function of a complex sound and then observing the movement of this reference point as the function translates one can generate a meaningful pitch contour consistent with human experience for example the vowel e has two primary formants one peaking between 400 and 600 hz and one between 2200 and 2600 hz when a person speaks a sentence involving multiple e sounds the peaks will shift within these ranges and the movement of the peaks between two instances establishes the difference in their values on the pitch contour
pitot pressure is the pressure that is measured by a pitot tube an open ended tube connected to a pressure measuring device for subsonic flow pitot pressure is equal to the stagnation pressure or total pressure of the flow and hence the term pitot pressure is often used interchangeably with these other terms for supersonic flow however pitot pressure is the stagnation pressure of the flow behind the normal shock ahead of the pitot tube pitot pressure is named for henri pitot french scientist
pitted keratolysis also known as keratolysis plantare sulcatum keratoma plantare sulcatum and ringed keratolysis is a non contagious skin infection that can be caused by wearing tight or restricting footwear and excessive sweating the infection is characterized by craterlike pits on the surface of the feet and toes particularly weight bearing areas treatment consists of the application of topical antibiotics pitted keratolysis is caused by bacteria which thrive in these environments the condition is fairly common especially in military where wet shoes boots are worn for extended period of time without removing cleaning skin biopsy specimens are not usually utilized as the diagnosis of pitted keratolysis is often made by visual examination and recognition of the characteristic odor wood lamp examination results are inconsistent
pitt – hopkins syndrome is a rare genetic disorder characterized by developmental delay a wide mouth distinctive facial features and intermittent hyperventilation followed by apnea it is associated with an abnormality within chromosome 18 specifically it is caused by an insufficient expression of the tcf 4 gene
pituicytoma is a rare brain tumor it grows at the base of the brain from the pituitary gland this tumor is thought to be derived from the parenchymal cells of the posterior lobe of the pituitary gland called pituicytes some researchers believe that they arise from the folliculostellate cells in the anterior lobe of the pituitary as such it is a low grade glioma it occurs in adults and symptoms include visual disturbance and endocrine dysfunction they are often mistaken for pituitary adenomas which have a similar presentation and occur in the same location the treatment consists of surgical resection which is curative in most cases
pituitary acth hypersecretion or cushing disease is a form of hyperpituitarism characterized by an abnormally high level of acth produced by the anterior pituitary it is one of the causes of cushing s syndrome however cushing s syndrome can be caused by many other causes including exogenous administration
pituitary adenomas are tumors that occur in the pituitary gland pituitary adenomas are generally divided into three categories dependent upon their biological functioning benign adenoma invasive adenoma and carcinomas with carcinomas accounting for 0 1 to 0 2 approximately 35 being invasive adenomas and most being benign adenomas pituitary adenomas represent from 10 to 25 of all intracranial neoplasms and the estimated prevalence rate in the general population is approximately 17 non invasive and non secreting pituitary adenomas are considered to be benign in the literal as well as the clinical sense however a recent meta analysis fernández balsells et al 2011 of available research has shown there are to date scant studies of poor quality to either support or refute this assumption adenomas which exceed 10 millimetres 0 39 in in size are defined as macroadenomas with those smaller than 10 mm referred to as microadenomas most pituitary adenomas are microadenomas and have an estimated prevalence of 16 7 14 4 in autopsy studies and 22 5 in radiologic studies a majority of pituitary microadenomas often remain undiagnosed and those that are diagnosed are often found as an incidental finding and are referred to as incidentalomas pituitary macroadenomas are the most common cause of hypopituitarism and in the majority of cases they are non secreting adenomas the pituitary gland is in close proximity to the brain invasive adenomas may invade the dura mater cranial bone or sphenoid bone while pituitary adenomas are extremely common affecting approximately one in 6 of the general population clinically active pituitary adenomas requiring surgical treatment are more rare affecting approximately one in 1000 of the general population
pituitary apoplexy or pituitary tumor apoplexy is bleeding into or impaired blood supply of the pituitary gland at the base of the brain this usually occurs in the presence of a tumor of the pituitary although in 80 of cases this has not been diagnosed previously the most common initial symptom is a sudden headache often associated with a rapidly worsening visual field defect or double vision caused by compression of nerves surrounding the gland this is followed in many cases by acute symptoms caused by lack of secretion of essential hormones predominantly adrenal insufficiency the diagnosis is achieved with magnetic resonance imaging and blood tests treatment is by the timely correction of hormone deficiencies and in many cases surgical decompression is required many people who have had a pituitary apoplexy develop pituitary hormone deficiencies and require long term hormone supplementation the first case of the disease was recorded in 1898
a pituitary disease is a disorder primarily affecting the pituitary gland the main disorders involving the pituitary gland are overproduction or underproduction of a pituitary hormone will affect the respective end organ for example insufficient production hyposecretion of thyroid stimulating hormone tsh in the pituitary gland will cause hypothyroidism while overproduction hypersecretion of tsh will cause hyperthyroidism thyroidisms caused by the pituitary gland are less common though accounting for less than 10 of all hypothyroidism cases and much less than 1 of hyperthyroidism cases
pityriasis commonly refers to flaking or scaling of the skin the word comes from the greek πίτυρον bran
pityriasis alba is a common skin condition mostly occurring in children and usually seen as dry fine scaled pale patches on the face it is self limiting and usually only requires use of moisturizer creams the condition is so named for the fine scaly appearance initially present pityriasis and the pallor of the patches that develop while alba is latin for white the patches in this condition are not totally depigmented
pityriasis amiantacea also known as tinea amiantacea is an eczematous condition of the scalp resulting in hair loss in which thick tenaciously adherent scale infiltrates and surrounds the base of a group of scalp hairs pityriasis amiantacea was first described by alibert in 1832 pityriasis amiantacea affects the scalp as shiny asbestos like amiantaceus thick scales attached in layers to the hair shaft the scales surround and bind down tufts of hair the condition can be localised or covering over the entire scalp temporary alopecia and scarring alopecia may occur due to repeated removal of hairs attached to the scale it is a rare disease with a female predilection pityriasis amiantacea can easily be misdiagnosed due its close resemblance to other scalp diseases such as psoriasis seborrhoeic dermatitis or lichen planus however in pityriasis amiantacea the scales are attached to both the hair shaft and the scalp pityriasis amiantacea may be present with other inflammatory conditions such as atopic dermatitis or seborrhoeic dermatitis and sebaceous scales and alopecia can occur according to the dermatology text bolognia this condition is most often seen in psoriasis but may also be seen in secondarily infected atopic dermatitis seborrheic dermatitis and tinea capitis
pityriasis lichenoides is a form of pityriasis types include pityriasis lichenoides et varioliformis acuta pityriasis lichenoides chronica
pityriasis lichenoides chronica also known as chronic guttate parapsoriasis chronic pityriasis lichenoides dermatitis psoriasiformis nodularis parapsoriasis chronica and parapsoriasis lichenoides chronica plc is an uncommon idiopathic acquired dermatosis characterized by evolving groups of erythematous scaly papules that may persist for months
pityriasis lichenoides et varioliformis acuta also known as acute guttate parapsoriasis acute parapsoriasis acute pityriasis lichenoides mucha – habermann disease parapsoriasis acuta parapsoriasis lichenoides et varioliformis acuta and parapsoriasis varioliformis is a disease of the immune system it is the more severe version of pityriasis lichenoides chronica the disease is characterized by rashes and small lesions on the skin the disease is more common in males and usually occurs in young adulthood although it has been seen in every age group and every race it is possible for the disease to go into remission for short periods of time or forever
pityriasis rosea also known as pityriasis rosea gibert is a skin rash it is benign but may inflict substantial discomfort in certain cases classically it begins with a single herald patch lesion followed in 1 or 2 weeks by a generalized body rash lasting up to 12 weeks however usually around 6 8
pityriasis rotunda also known as pityriasis circinata and tinea circinata is a disorder of keratisation of the skin that manifests as a perfectly circular scaly patches on the torso and proximal portions of the extremities it may be associated with diseases like hepatocellular carcinoma in racially predisposed groups
pityriasis rubra pilaris also known as devergie s disease lichen ruber acuminatus and lichen ruber pilaris refers to a group of chronic disorders characterized by reddish orange scaling plaques and keratotic follicular papules symptoms may include reddish orange patches latin rubra on the skin severe flaking latin pityriasis uncomfortable itching thickening of the skin on the feet and hands and thickened bumps around hair follicles latin pilus for hair for some early symptoms may also include generalized swelling of the legs feet and other parts of the body prp has a varied clinical progression and a varied rate of improvement there is no known cause or cure although stress is a common factor it was first described by marie guillaume alphonse devergie in 1856 and the condition is also known as devergie s disease
pityrosporum folliculitis or malassezia folliculitis is a skin condition caused by infection by pityrosporum yeast the skin of the upper trunk area including the back chest arms and sometimes the neck is often affected and this condition is often seen in young to middle aged adults although it has been known to occur in adults well into their sixties and can also be found on the lower extremities as well its diagnosis is based on the pruritic itchy papulopustules found in a follicular pattern in these regions although pustules form from an overgrowth of the yeast malessezia furfur plugging the follicles m furfur is lipophilic requiring fatty acids like what is present in oily skin to proliferate it has been shown that pityrosporum yeast grows by consuming fatty acids with carbon chain lengths c 11 to c 24 pityrosporum is part of the normal skin flora but overgrows in certain conditions overgrowth is associated with oily skin humidity or other pre existing dermatologic conditions such as seborrheic dermatitis and severe dandruff
placenta accreta occurs when all or part of the placenta attaches abnormally to the myometrium the muscular layer of the uterine wall three grades of abnormal placental attachment are defined according to the depth of invasion accreta – chorionic villi attach to the myometrium rather than being restricted within the decidua basalis increta – chorionic villi invade into the myometrium percreta – chorionic villi invade through the myometrium because of abnormal attachment to the myometrium placenta accreta is associated with an increased risk of heavy bleeding at the time of attempted placental delivery the need for transfusion of blood products is frequent and hysterectomy is sometimes required to control life threatening hemorrhage
placenta previa is an obstetric complication in which the placenta is inserted partially or wholly in the lower uterine segment it is a leading cause of antepartum haemorrhage vaginal bleeding it affects approximately 0 4 0 5 of all labours in the last trimester of pregnancy the isthmus of the uterus unfolds and forms the lower segment in a typical pregnancy the placenta does not overlie if the placenta does overlie the lower segment as is the case with placenta previa it may shear off and a small section may bleed
placental abruption also known as abruptio placentae is a complication of pregnancy wherein the placental lining has separated from the uterus of the mother prior to delivery it is the most common pathological cause of late pregnancy bleeding in humans it refers to the abnormal separation after 20 weeks of gestation and prior to birth it occurs on average in 0 5 or 1 in 200 deliveries placental abruption is a significant contributor to maternal mortality worldwide early and skilled medical intervention is needed to ensure a good outcome and this is not available in many parts of the world treatment depends on how serious the abruption is and how far along the woman is in her pregnancy placental abruption has effects on both mother and fetus the effects on the mother depend primarily on the severity of the abruption while the effects on the fetus depend on both its severity and the gestational age at which it occurs the heart rate of the fetus can be associated with the severity
a placental disease is any disease disorder or pathology of the placenta the article also covers placentation abnormalities which is often used synonymously for placental disease
a placental infarction results from the interruption of blood supply to a part of the placenta causing its cells to die small placental infarcts especially at the edge of the placental disc are considered to be normal at term large placental infarcts are associated with vascular abnormalities e g hypertrophic decidual vasculopathy as seen in hypertension very large infarcts lead to placental insufficiency and may result in fetal death
placental insufficiency or utero placental insufficiency is insufficient blood flow to the placenta during pregnancy the term is also sometimes used to designate late decelerations of fetal heart rate as measured by electronic monitoring even if there is no other evidence of reduced blood flow to the placenta normal uterine blood flow rate being 600 ml min
a placental site nodule abbreviated psn is benign remnant from a previous pregnancy
placental site trophoblastic tumor is a form of gestational trophoblastic disease which is thought to arise from intermediate trophoblast it may secrete human placental lactogen human chorionic somatomammotropin and result in a false positive pregnancy test placental site trophoblastic tumor is a monophasic neoplasm of the implantation site intermediate trophoblast and usually a benign lesion which comprises less than 2 of all gestational trophoblastic proliferations preceding conditions include molar pregnancy 5 compared to choriocarcinoma or invasive mole hemorrhage is less conspicuous and serum β hcg level is low making early diagnosis difficult immunohistochemistry often stains with hpl keratin mel cam egfr prognosis 10 20 of cases metastase leading to death treatment because chemotherapy is ineffective the patient should undergo hysterectomy
placental villous immaturity also villous immaturity and villous dysmaturity is chorionic villous development that is inappropriate for the gestational age it is associated with diabetes mellitusand fetal death near term i e intrauterine demise close to the normal gestational period
in geology a placer deposit or placer is an accumulation of valuable minerals formed by gravity separation during sedimentary processes the name is from the spanish word placer meaning alluvial sand placer mining is an important source of gold and was the main technique used in the early years of many gold rushes including the california gold rush types of placer deposits include alluvium eluvium beach placers and paleoplacers placer materials must be both dense and resistant to weathering processes to accumulate in placers mineral particles must be significantly denser than quartz whose specific gravity is 2 65 as quartz is usually the largest component of sand or gravel placer environments typically contain black sand a conspicuous shiny black mixture of iron oxides mostly magnetite with variable amounts of ilmenite and hematite valuable mineral components often occurring with black sands are monazite rutile zircon chromite wolframite and cassiterite
plagiocephaly also known as flat head syndrome is a condition characterized by an asymmetrical distortion flattening of one side of the skull it is characterized by a flat spot on the back or one side of the head caused by remaining in a supine position for too long plagiocephaly is the word that is used to describe a diagonal asymmetry across the head shape this word particularly describes a flattening which is to one side at the back of the head and there is often some facial asymmetry plagiocephaly divides into two groups synostotic plagiocephaly with one or more fused cranial sutures and nonsynostotic deformational plagiocephaly surgical treatment of these groups includes the deference method however the treatment of deformational plagiocephaly is controversial brachycephaly describes a very wide head shape with a flattening across the whole back of the head
plague is an infectious disease that is caused by the bacterium yersinia pestis depending on lung infection or sanitary conditions plague can be spread in the air by direct contact or very rarely by contaminated undercooked food the symptoms of plague depend on the concentrated areas of infection in each person bubonic plague in lymph nodes septicemic plague in blood vessels pneumonic plague in lungs it is treatable if detected early plague is still relatively common in some remote parts of the world until june 2007 plague was one of the three epidemic diseases specifically reportable to the world health organization cholera and yellow fever the other two the bacterium is named after the french swiss bacteriologist alexandre yersin historically what are thought to have been massive pandemics of plague swept through eurasia with very high death rates and causing major cultural changes the largest of these were the plague of justinian of 541 – 542 the black death of the 1340 s continuing in the second plague pandemic to break out at intervals and the third plague pandemic beginning in 1855 and considered inactive from 1959 the epidemiological use of the term plague is currently applied to any severe bubo inflammation resulting from an infection with y pestis historically the medical use of the term plague has been applied to pandemic infections in general plague is often synonymous with bubonic plague but this describes just one of its manifestations other names have been used to describe this disease such as black plague and the black death the latter is now used primarily by scholars to describe the second and most devastating pandemic of the disease the etymology of the word plague is believed to come from the latin word plāga blow wound and plangere “ to strike or to strike down ” cf german plage “ infestation ”
in graph theory the planarity testing problem is the algorithmic problem of testing whether a given graph is a planar graph that is whether it can be drawn in the plane without edge intersections this is a well studied problem in computer science for which many practical algorithms have emerged many taking advantage of novel data structures most of these methods operate in o n time linear time where n is the number of edges or vertices in the graph which is asymptotically optimal rather than just being a single boolean value the output of a planarity testing algorithm may be a planar graph embedding if the graph is planar or an obstacle to planarity such as a kuratowski subgraph if it is not
planispiral is a condition in which a tubicolous shell is coiled in a single horizontal plane and the diameter increases away from the axis of coiling this term is usually used for describing gastropod shells many cephalopods and tubeworms can also have a planispiral shell allaby and allaby 1999
the planning fallacy first proposed by daniel kahneman and amos tversky in 1979 is a phenomenon in which predictions about how much time will be needed to complete a future task display an optimism bias and underestimate the time needed this phenomenon occurs regardless of the individual s knowledge that past tasks of a similar nature have taken longer to complete than generally planned the bias only affects predictions about one s own tasks when outside observers predict task completion times they show a pessimistic bias overestimating the time needed the planning fallacy requires that predictions of current tasks completion times are more optimistic than the beliefs about past completion times for similar projects and that predictions of the current tasks completion times are more optimistic than the actual time needed to complete the tasks in 2003 lovallo and kahneman proposed an expanded definition as the tendency to underestimate the time costs and risks of future actions and at the same time overestimate the benefits of the same actions according to this definition the planning fallacy results in not only time overruns but also cost overruns and benefit shortfalls
the planning horizon is the amount of time an organization will look into the future when preparing a strategic plan many commercial companies use a five year planning horizon however a general planning horizon is around one year other organizations such as the forestry commission in the uk have to use a much longer planning horizon to form effective plans in manufacturing a planning horizon is a future time period during which departments that support production will plan production work and determine material requirements in economics a planning horizon is the length of time an individual plans ahead it s important in the quest for total value as opposed to short term pleasure consumption
plant perception is the ability of plants to sense and respond to the environment to adjust their morphology physiology and phenotype accordingly other disciplines such as plant physiology ecology and molecular biology are used to assess this ability plants react to chemicals gravity light moisture infections temperature oxygen and carbon dioxide concentrations parasite infestation disease physical disruption sound and touch
tolerance is the ability of plants to mitigate the negative fitness effects caused by herbivory it is one of the general plant defense strategies against herbivores the other being resistance which is the ability of plants to prevent damage strauss and agrawal 1999 plant defense strategies play important roles in the survival of plants as they are fed upon by many different types of herbivores especially insects which may impose negative fitness effects strauss and zangerl 2002 damage can occur in almost any part of the plants including the roots stems leaves flowers and seeds strauss and zergerl 2002 in response to herbivory plants have evolved a wide variety of defense mechanisms and although relatively less studied than resistance strategies tolerance traits play a major role in plant defense strauss and zergerl 2002 rosenthal and kotanen 1995 traits that confer tolerance are controlled genetically and therefore are heritable traits under selection strauss and agrawal 1999 many factors intrinsic to the plants such as growth rate storage capacity photosynthetic rates and nutrient allocation and uptake can affect the extent to which plants can tolerate damage rosenthal and kotanen 1994 extrinsic factors such as soil nutrition carbon dioxide levels light levels water availability and competition also have an effect on tolerance rosenthal and kotanen 1994
plantar calcaneal bursitis is a medical condition in which there is inflammation of the plantar calcaneal bursa a spongy fluid filled sac that cushions the fascia of the heel and the calcaneus heel bone it is characterized by swelling and tenderness of the central plantar heel area it is sometimes called policeman s heel it sometimes was and should not be confused with plantar fasciitis which is inflammation of the plantar fascia and can affect any part of the foot
plantar fasciitis is a disorder that results in pain in the heel and bottom of the foot the pain is usually most severe with the first steps of the day or following a period of rest pain is also frequently brought on by bending the foot and toes up towards the shin and may be worsened by a tight achilles tendon the condition typically comes on slowly in about a third of people both legs are affected typically there are no fevers or night sweats the causes of plantar fasciitis are not entirely clear risk factors include overuse such as from long periods of standing an increase in exercise and obesity it is also associated with inward rolling of the foot and a lifestyle that involves little exercise while heel spurs are frequently found it is unclear if they have a role in causing the condition plantar fasciitis is a disorder of the insertion site of the ligament on the bone characterized by micro tears breakdown of collagen and scarring as inflammation plays a lesser role many feel the condition should be renamed plantar fasciosis the diagnosis is typically based on signs and symptoms with ultrasound sometimes used to help other conditions with similar symptoms include osteoarthritis ankylosing spondylitis heel pad syndrome and reactive arthritis most cases of plantar fasciitis resolve with time and conservative methods of treatment usually for the first few weeks people are advised to rest change their activities take pain medications and stretch if this is not sufficient physiotherapy orthotics splinting or steroid injections may be options if other measures do not work extracorporeal shockwave therapy or surgery may be tried between 4 and 7 of people have heel pain at any given time and about 80 of these cases are due to plantar fasciitis approximately 10 of people have the disorder at some point during their life it becomes more common with age it is unclear if one sex is more affected than the other
plantar fascial fibromatosis also known as ledderhose s disease morbus ledderhose and plantar fibromatosis is a relatively uncommon non malignant thickening of the feet s deep connective tissue or fascia in the beginning where nodules or cords start growing along tendons of the foot the disease is minor eventually however the cords thicken the toes stiffen and bend and walking becomes painful the disease is named after dr georg ledderhose a german surgeon who described the condition for the first time in 1894 a similar disease is dupuytren s disease which affects the hand and causes bent hand or fingers as in most forms of fibromatosis it is usually benign and its onset varies with each patient the nodules are typically slow growing and most often found in the central and medial portions of the plantar fascia occasionally the nodules may lie dormant for months to years only to begin rapid and unexpected growth options for intervention include radiation therapy cryosurgery xiaflex surgical removal only if discomfort hinders walking
a plantar wart or verruca is a wart occurring on the sole or toes of the foot caused by the human papillomavirus hpv hpv infections in other locations are not plantar see human papillomavirus plantar warts are usually self limiting but treatment is generally recommended to lessen symptoms which may include pain decrease duration and reduce transmission infection occurs in an estimated 7 – 10 of the us population and genetics plays an important role in determining susceptibility
plasma cell dyscrasias are disorders of the plasma cells plasma cell dyscrasias are produced as a result of abnormal proliferation of a monoclonal population of plasma cells that may or may not secrete detectable levels of a monoclonal immunoglobulin or immunoglobulin fragment paraprotein or m protein although the most common plasma cell dyscrasia is monoclonal gammopathy of undetermined significance mgus closely related disorders include multiple myeloma solitary plasmacytoma of bone extramedullary plasmacytoma waldenström s macroglobulinemia wm primary amyloidosis light chain deposition disease paraproteinemia and heavy chain disease the spectrum of mgus solitary plasmacytoma of bone and asymptomatic and symptomatic multiple myeloma may actually represent a natural progression of the same disease
plasma cell gingivitis is a rare condition appearing as generalized erythema redness and edema swelling of the attached gingiva occasionally accompanied by cheilitis lip swelling or glossitis tongue swelling it is called plasma cell gingivitis where the gingiva gums are involved plasma cell cheilitis where the lips are involved and other terms such as plasma cell orifacial mucositis or plasma cell gingivostomatitis where several sites in the mouth are involved on the lips the condition appears as sharply outlined infiltrated dark red plaque with a lacquer like glazing of the surface of the involved oral area
plasma cell granuloma is a lesional pattern of inflammatory pseudotumour different from the inflammatory myofibroblastic tumor pattern it is linked to igg 4 related disease
plasma cell leukemia pcl a lymphoproliferative disorder is a rare cancer involving a subtype of white blood cells called plasma cells plasma cell leukemia is one of the most aggressive human neoplasms and constitutes 2 to 4 of all cases of plasma cell disorders the who criterion for diagnosis of pcl is that plasma cells constitute more than 20 of cells in the peripheral blood with an absolute plasma cell count of more than 2 × 109 l the presentation may be primary de novo or secondary evolving from an existing case of multiple myeloma as part of the terminal phase of the disease approximately 60 to 70 of cases are primary
the plasma effect is a computer based visual effect animated in real time it uses cycles of changing colours warped in various ways to give an illusion of liquid organic movement plasma was probably invented by demo coders for use in their demos where the effect was heavily used especially in the early 1990 s the effect was particularly common on the commodore amiga where it could be implemented very efficiently by using the features of the proprietary display hardware plasma can also be implemented easily in software rendering by using sinus tables and pseudocolor palettes and it has also been the first true demo effect for many beginning pc democoders the fractal software fractint also incorporates an algorithm known as plasma which when combined with the color cycling feature of the software can provide a result which resembles a typical plasma effect used in demos the technical basis however is completely different and a color cycling plasma is somewhat less dynamic than a demo plasma similar effects are easily implement on modern gpus in pixel shaders
plasmablastic lymphoma is a type of large b cell lymphoma recognized in the who 2008 classification it is cd 20 negative and has an immunophenotype that resembles plasma cells in formal use lymphomas with plasmablastic immunophenotype such as primary effusion lymphoma alk large b cell lymphoma large b cell lymphoma arising in hhv 8 associated multicentric castleman s disease and extracavitary hhv – 8 positive lymphoma are not part of this category although sometimes the literature has confused this point
plasmacytoma refers to a malignant plasma cell tumor growing within soft tissue or within the axial skeleton there are three distinct groups of plasmacytoma defined by the international myeloma working group solitary plasmacytoma of bone spb extramedullary plasmacytoma ep and multiple plasmacytomas that are either primary or recurrent the most common of these is spb accounting for 3 – 5 of all plasma cell malignancies spbs occur as lytic lesions within the axial skeleton and extramedullary plasmacytomas most often occur in the upper respiratory tract 85 but can occur in any soft tissue approximately half of all cases produce paraproteinemia spbs and extramedullary plasmacytomas are mostly treated with radiotherapy but surgery is used in some cases of extramedullary plasmacytoma the skeletal forms frequently progress to multiple myeloma over the course of 2 – 4 years due to their cellular similarity plasmacytomas have to be differentiated from multiple myeloma for spb and extramedullary plasmacytoma the distinction is the presence of only one lesion either in bone or soft tissue normal bone marrow 5 plasma cells normal skeletal survey absent or low paraprotein and no end organ damage
plasmacytosis is a condition in which there is an unusually large proportion of plasma cells in tissues exudates or blood plasmacytosis may be divided into two types — cutaneous and systemic — both of which have identical skin findings patients with plasmacytosis have been predominantly found to have lung infections pneumonia tuberculosis abscess whereas multiple myeloma is rarely found
plasmoacanthoma is a condition of the oral mucosa characterized by a verrucous tumor with a plasma cell infiltrate
plate like osteoma cutis is a congenital condition characterized by firm papules and nodules on the skin
plateau iris is a medical condition of the eye resulting from pushing of peripheral part of iris forward by the large or anteriorly placed ciliary body causing angle closer glaucoma this configuration is usually corrected by iridectomy if the glaucoma persists even after iridectomy then it is called plateau iris syndrome this is managed by miotics or laser peripheral iridoplasty
plateau pressure pplat is the pressure applied to small airways and alveoli during positive pressure mechanical ventilation it is measured during an inspiratory pause on the mechanical ventilator
platelet storage pool deficiency is a type of coagulopathy characterized by defects in the granules in platelets particularly a lack of granular non metabolic adp patients with adp deficient storage pool disease present a prolonged bleeding time due to impaired aggregation response to fibrillar collagen it may involve the alpha granules or the dense granules
platinosis is an allergy like reaction to exposure to soluble salts of platinum the symptoms of platinosis may include asthma dermatitis dyspnea conjunctival vasodilatation and rhinopharyngitis the symptoms are progressive sometimes taking months to years to appear platinosis is usually associated with workers in industries related to platinum production the effects are permanent halogeno platinum compounds are among the most potent respiratory and skin sensitisers known therefore it is vital that exposure via the skin and by breathing contaminated air is carefully controlled in practice the compounds mainly responsible for platinum sensitisation are typically the soluble ionic platinum chloro compounds such as ammonium hexachloroplatinate and tetrachloroplatinate and hexachloroplatinic acid other ionic halogeno compounds are also sensitisers the order of allergenicity being cl br i neutral compounds such as cis platin and ammine and nitro complexes such as pt nh 3 4 cl 2 k 2 pt no 2 4 and platinum nitrate are not considered to be allergenic neither is the metal
platybasia is a spinal disease of a malformed relationship between the occipital bone and cervical spine it may be caused by paget s disease platybasia is also a feature of gorlin goltz syndrome commonly known as basal cell nevus syndrome
platyspondylic lethal skeletal dysplasia torrance type is a severe disorder of bone growth people with this condition have very short arms and legs a small chest with short ribs underdeveloped pelvic bones and unusually short fingers and toes brachydactyly this disorder is also characterized by flattened spinal bones platyspondyly and abnormal curvature of the spine lordosis as a result of these serious skeletal problems many infants with platyspondylic lethal skeletal dysplasia torrance type are born prematurely are stillborn or die shortly after birth from respiratory failure a few affected people with milder signs and symptoms have lived into adulthood however this condition is one of a spectrum of skeletal disorders caused by mutations in the col 2 a 1 gene this gene provides instructions for making a protein that forms type ii collagen this type of collagen is found mostly in cartilage and in the clear gel that fills the eyeball the vitreous it is essential for the normal development of bones and other tissues that form the body s supportive framework connective tissues mutations in the col 2 a 1 gene interfere with the assembly of type ii collagen molecules resulting in a reduced amount of this type of collagen in the body instead of forming collagen molecules the abnormal col 2 a 1 protein builds up in cartilage cells chondrocytes these changes disrupt the normal development of bones and other connective tissues leading to the skeletal abnormalities characteristic of platyspondylic lethal skeletal dysplasia torrance type this condition is inherited in an autosomal dominant pattern which means one copy of the altered gene in each cell is sufficient to cause the disorder in some cases an affected person inherits the mutation from one affected parent other cases may result from new mutations in the gene these cases occur in people with no history of the disorder in their family
plausible deniability is the ability for persons typically senior officials in a formal or informal chain of command to deny knowledge of or responsibility for any damnable actions committed by others usually subordinates in an organizational hierarchy because of a lack of evidence that can confirm their participation even if they were personally involved in or at least willfully ignorant of the actions in the case that illegal or otherwise disreputable and unpopular activities become public high ranking officials may deny any awareness of such act in order to insulate themselves and shift blame onto the agents who carried out the acts confident that their doubters will be unable to prove otherwise the lack of evidence to the contrary ostensibly makes the denial plausible that is credible although sometimes it merely makes it unactionable the term typically implies forethought such as intentionally setting up the conditions to plausibly avoid responsibility for one s future actions or knowledge in some organizations legal doctrines such as command responsibility exist to hold major parties responsible for the actions of subordinates involved in heinous acts and nullify any legal protection that their denial of involvement would carry in politics and espionage deniability refers to the ability of a powerful player or intelligence agency to pass the buck and avoid blowback by secretly arranging for an action to be taken on their behalf by a third party ostensibly unconnected with the major player in political campaigns plausible deniability enables candidates to stay clean and denounce third party advertisements that use unethical approaches or potentially libellous innuendo in the us plausible deniability is also a legal concept it refers to lack of evidence proving an allegation standards of proof vary in civil and criminal cases in civil cases the standard of proof is preponderance of the evidence whereas in a criminal matter the standard is beyond a reasonable doubt if an opponent cannot provide evidence for his allegation one can plausibly deny the allegation even though it may be true although plausible deniability has existed throughout history that name for it was coined by the cia in the early 1960 s to describe the withholding of information from senior officials in order to protect them from repercussions in the event that illegal or unpopular activities by the cia became public knowledge the roots of the name go back to harry truman s national security council paper 10 2 of june 18 1948 which defined covert operations as all activities conducted pursuant to this directive which are so planned and executed that any u s government responsibility for them is not evident to unauthorized persons and that if uncovered the u s government can plausibly disclaim any responsibility for them nsc 5412 was de classified in 1977 and is located at the national archives rg 273
a plectron is a specialized vhf uhf single channel emergency alerting radio receiver used to activate emergency response personnel and disaster warning systems manufactured from the late 1950 s through the late 1990 s by the now defunct plectron corporation in overton nebraska hundreds of thousands of these radios were placed in homes of first responders across all of north america this included ambulance crews full time and volunteer firefighters off duty specialized police response teams civil defense members and search and rescue teams a plectron s main feature distinguishing it from a regular squelched radio was its selective de squelching it would only sound when a correct pair of tones were broadcast allowing many agencies with different tones to share the same frequency some plectron models had a set of built in re chargeable batteries for this made the plectron portable the motorola minitor pager also uses this function and has largely replaced the plectron
pleochroism is an optical phenomenon in which a substance appears to be different colors when observed at different angles especially with polarized light
pleomorphic t cell lymphoma also known as non mycosis fungoides cd 30 − pleomorphic small medium sized cutaneous t cell lymphoma is a cutaneous condition characterized by a 5 year survival rate of 62
pleomorphic adenoma is a common benign salivary gland neoplasm characterised by neoplastic proliferation of parenchymatous glandular cells along with myoepithelial components having a malignant potentiality it is the most common type of salivary gland tumor and the most common tumor of the parotid gland it derives its name from the architectural pleomorphism variable appearance seen by light microscopy it is also known as mixed tumor salivary gland type which describes its pleomorphic appearance as opposed to its dual origin from epithelial and myoepithelial elements
pleomorphic lipomas like spindle cell lipomas occur for the most part on the backs and necks of elderly men and are characterized by floret giant cells with overlapping nuclei
pleomorphic undifferentiated sarcoma abbreviated pus also undifferentiated pleomorphic sarcoma and previously malignant fibrous histiocytoma abbreviated mfh is a type of soft tissue sarcoma it is considered a diagnosis of exclusion for sarcomas that cannot be more precisely categorized
pleomorphic xanthoastrocytoma pxa is a brain tumor that occurs most frequently in children and teenagers at boston children s hospital the average age at diagnosis is 12 years pleomorphic xanthoastrocytoma usually develops within the supratentorial region the area of the brain located above the tentorium cerebelli it is generally located superficially in the uppermost sections in the cerebral hemispheres and involves the leptomeninges it rarely arises from the spinal cord these tumors are formed through the mitosis of astrocytes they are found in the area of the temples in the brain s frontal lobe or on top of the parietal lobe in about 20 of cases tumors exist in more than one lobe
in microbiology pleomorphism from greek πλέω more and μορφή form is the ability of some bacteria to alter their shape or size in response to environmental conditions pleomorphism has been observed in some members of the deinococcaceae family the modern definition of pleomorphism in the context of bacteriology is based on variation of size or shape of the cell rather than a change of shape as previously believed
a pleural effusion is excess fluid that accumulates in the pleural cavity the fluid filled space that surrounds the lungs this excess can impair breathing by limiting the expansion of the lungs various kinds of pleural effusion depending on the nature of the fluid and what caused its entry into the pleural space are hydrothorax serous fluid hemothorax blood urinothorax urine chylothorax chyle or pyothorax pus a pneumothorax is the accumulation of air in the pleural space and is commonly called a collapsed lung
pleural empyema also known as pyothorax or purulent pleuritis is empyema an accumulation of pus in the pleural cavity that can develop when bacteria invade the pleural space usually in the context of a pneumonia it is one of various kinds of pleural effusion there are three stages exudative when there is an increase in pleural fluid with or without the presence of pus fibrinopurulent when fibrous septa form localized pus pockets and the final organizing stage when there is scarring of the pleura membranes with possible inability of the lung to expand simple pleural effusions occur in up to 40 of bacterial pneumonias they are usually small and resolve with appropriate antibiotic therapy if however an empyema develops additional intervention is required
pleurisy also known as pleuritis is an inflammation of the pleurae the membranes of the pleural cavity surrounding the lungs there are many possible causes of pleurisy but viral infections spreading from the lungs to the pleural cavity are the most common the inflamed pleural layers rub against each other every time the lungs expand to breathe in air this can cause sharp pain when breathing also called pleuritic chest pain the condition may either be primary or secondary and is often associated with a pleural effusion
pleuropneumonia is inflammation of the lungs and pleura pleurisy being the inflammation of the pleura alone
pleuropulmonary blastoma ppb is a rare cancer originating in the lung or pleural cavity it occurs most often in infants and young children but also has been reported in adults in a retrospective review of 204 children with lung tumors pleuropulmonary blastoma and carcinoid tumor were the most common primary tumors 83 of the 204 children had secondary tumors spread from cancers elsewhere in the body pleuropulmonary blastoma is regarded as malignant
pleurothotonus commonly known as pisa syndrome is a rare neurological disorder which occurs due to prolonged exposure to antipsychotic drugs which may also be referred to as neuroleptics it is characterized by dystonia and abnormal and sustained involuntary muscle contraction this may cause twisting or jerking movements of the body or a body part although pisa syndrome develops most commonly in those undergoing long term treatment with antipsychotics it has been reported less frequently in patients receiving other medications such as an acetylcholinesterase inhibitor however it has also been seen in those with other diseases causing neurodegeneration and in those who are not receiving any medication idiopathic pisa syndrome the characteristic development of pisa syndrome consists of two types of dystonia acute dystonia and tardive dystonia also known as tardive dyskinesia the underlying pathology of drug induced pisa syndrome is very complex and development may be due to an underlying dopaminergic cholinergic imbalance or serotonergic noradrenergic dysfunction
plexiform fibrohistiocytic tumor is a rare tumor that arises primarily on the upper extremities of children and young adults
plexopathy is a disorder affecting a network of nerves blood vessels or lymph vessels the region of nerves it affects are at the brachial or lumbosacral plexus symptoms include pain loss of motor control and sensory deficits there are two main types of plexopathy brachial plexopathy and lumbosacral plexopathy they are usually caused from some sort of localized trauma such as a dislocated shoulder the disorder can also be caused secondary to a compression co morbid vascular disease infection or may be idiopathic with an unknown cause both plexopathies can also occur as a consequence of radiation therapy sometimes after 30 or more years have passed in conditions known as radiation induced brachial plexopathy ribp and radiation induced lumbosacral plexopathy rilp
plica syndrome also known as synovial plica syndrome is a condition which occurs when a plica an extension of the protective synovial capsule of the knee becomes irritated enlarged or inflamed
plinian eruptions also known as vesuvian eruptions are volcanic eruptions marked by their similarity to the eruption of mount vesuvius in 79 ad the eruption was described in a letter written by pliny the younger it killed his uncle pliny the elder plinian eruptions are marked by columns of gas and volcanic ash extending high into the stratosphere the second layer of earth s atmosphere the key characteristics are ejection of large amount of pumice and very powerful continuous gas blast eruptions according to the volcanic explosivity index plinian eruptions have a vei of 4 5 or 6 short eruptions can end in less than a day but longer events can take several days to months the longer eruptions begin with production of clouds of volcanic ash sometimes with pyroclastic flows the amount of magma erupted can be so large that it depletes the magma chamber below causing the top of the volcano to collapse resulting in a caldera fine ash can deposit over large areas plinian eruptions are often accompanied by loud noises such as those generated by krakatoa the lava is usually rhyolitic and rich in silicates basaltic lavas are unusual for plinian eruptions the most recent basaltic example is the 1886 eruption of mount tarawera on new zealand s north island
plot drift is a phenomenon in storytelling in which the plot of the story deviates from its apparent initial direction the phenomenon can affect written works although it is often more noticeable in performed media such as television shows or movies plot drift is generally though not always seen as contrary to good storytelling technique a sign of plot drift can be the increased introduction of new characters and settings near the end of a story a contrary literary technique might include the apparent introduction of plot drift only to later reveal a connection to the rest of the story
plottage is the increase in value realized by combining adjacent parcels of land into one larger parcel the process of combining the parcels is known as assemblage generally the value of the whole parcel will be greater than the sum of the individual smaller parcels
plucking also referred to as quarrying is a glacial phenomenon that is responsible for the erosion and transportation of individual pieces of bedrock especially large joint blocks this occurs in a type of glacier called a valley glacier as a glacier moves down a valley friction causes the basal ice of the glacier to melt and infiltrate joints cracks in the bedrock the freezing and thawing action of the ice enlarges widens or causes further cracks in the bedrock as it changes volume across the ice water phase transition a form of hydraulic wedging gradually loosening the rock between the joints this produces large pieces of rock called joint blocks eventually these joint blocks come loose and become trapped in the glacier in this way plucking has been linked to regelation rocks of all sizes can become trapped in the bottom of the glacier joint blocks up to three meters have been plucked and transported these entrained rock fragments can also cause abrasion along the subsequent bedrock and walls plucking also leads to chatter marks wedge shaped indentations left on the bedrock or other rock surfaces glacial plucking both exploits pre existing fractures in the bedrock and requires continued fracturing to maintain the cycle of erosion glacial plucking is most significant where the rock surface is well jointed or fractured or where it contains exposed bed planes as this allows meltwater and clasts to penetrate more easily plucking of bedrock also occurs in steep upland rivers and shares a number of similarities with glacial examples in such cases the loosening and detachment of blocks appears to result from a combination of 1 chemical and physical weathering along joints 2 hydraulic wedging driven by smaller rock fragments getting into existing cracks 3 crack propagation from stresses caused by impacts of large clasts already in transport by the river and possibly 4 crack propagation driven by flexing resulting from pressure variation in the overlying water during floods loosened blocks are then carried away by fast flowing water during large floods though the entrainment is believed to be significantly less efficient than the equivalent ability of ice to carry away blocks under glaciers
plumbosolvency is the ability of a solvent notably water to dissolve lead in the public supply of water this is an undesirable property in usually older consumers premises plumbosolvent water can attack lead pipes and any lead in solder used to join copper plumbosolvency of water can be countered by achieving a ph of 7 5 by increasing the ph with lime or sodium hydroxide lye or by providing a protective coating to the inside of lead pipes by the addition of phosphate at the water treatment works while optimal ph for prevention of plumbosolvency is 7 5 performance remains very good in the range ph 7 2 7 6 achieving this ph has been shown to decrease population blood lead concentrations 3 4 chlorinating water also reduces dissolved lead it causes the interiors of lead pipes to become coated with lead chloride which is very insoluble in cold water however lead chloride is fairly soluble in hot water for this reason water that is to be used for drinking or the preparation of food should never be taken from a hot water tap if the water may have been in contact with lead water should be taken from a cold water tap and heated in a pan or kettle that does not contain lead or lead solder
plummer – vinson syndrome pvs also called paterson – brown – kelly syndrome or sideropenic dysphagia is a rare disease characterized by difficulty in swallowing iron deficiency anemia glossitis cheilosis and esophageal webs treatment with iron supplementation and mechanical widening of the esophagus generally provides an excellent outcome while exact data about the epidemiology is unknown this syndrome has become extremely rare the reduction in the prevalence of pvs has been hypothesized to be the result of improvements in nutritional status and availability in countries where the syndrome was previously described it generally occurs in postmenopausal women its identification and follow up is considered relevant due to increased risk of squamous cell carcinomas of the esophagus and pharynx
pneumatic trail or trail of the tire is a trail like effect generated by compliant tires rolling on a hard surface and subject to side loads as in a turn more technically it is the distance that the resultant force of side slip occurs behind the geometric center of the contact patch
pneumatolysis is the alteration of rock or mineral crystallization affected by gaseous emanations from solidifying magma the term was coined by robert bunsen in 1851 magmatic gases may through pneumatolysis create skarn in interaction with limestone or greisen with granite or schist the term pneumatolysis has been used for various geological environments but the essential feature of most usage has been mineral formation from a hot fluid of low density the best evidence for pneumatolytic conditions is found in the presence of vapor rich fluid inclusions but considerable ambiguity remains and hence such evidence must be used with care many samples formerly thought to be of pneumatolytic origin were more likely formed from dense solutions that boiled or effervesced
pneumatosis intestinalis also called intestinal pneumatosis pneumatosis cystoides intestinalis or pneumatosis coli is pneumatosis of an intestine that is gas cysts in the bowel wall as a radiological sign it is highly suggestive for necrotizing enterocolitis this is in contrast to gas in the intestinal lumen which is relieved by flatulence in newborns pneumatosis intestinalis is considered diagnostic for necrotizing enterocolitis and the air is produced by bacteria in the bowel wall the pathogenesis of pneumatosis intestinalis is poorly understood and is likely multifactorial pi itself is not a disease but rather a clinical sign in some cases pi is an incidental finding whereas in others it portends a life threatening intra abdominal condition pneumatosis intestinalis at computed tomography in intestinal ischemia lung window for better representation of the gas deposits in the intestinal walls coronal reconstruction pneumatosis intestinalis in the coronal computed tomography in lung window it can be seen next to gas entrapment in the bowel wall and gas in the stomach wall and in numerous vessels including the portal vein into the liver pneumatosis intestinalis in computed tomography with intestinal ischemia lung window for better representation of the gas deposits in the intestinal walls upright ap radiograph showing gas in the wall of the small bowel in the left upper quadrant indicative of pneumatosis intestinalis coronal reformatted mdct image showing extensive pneumatosis intestinalis in the left upper quadrant small bowel the pneumatosis is more cystic and nodular in the small bowel in the midline and the right of midline this patient had a relatively benign presentation without bowel ischemia and was treated conservatively
pneumaturia is the passage of gas or air in urine this may be seen or described as bubbles in the urine
pneumobilia is the presence of gas in the biliary system it is typically detected on a radiographic imaging exam such as ultrasound ct or mri it is a common finding in patients that have recently undergone biliary surgery or endoscopic biliary procedure while the presence of air within biliary system is not harmful this finding may alternatively suggest a pathological process such as a biliary enteric anastomosis an infection of the biliary system an incompetent sphincter of oddi or spontaneous biliary enteric fistula
pneumocephalus is the presence of air or gas within the cranial cavity it is usually associated with disruption of the skull after head and facial trauma tumors of the skull base after neurosurgery or otorhinolaryngology and rarely spontaneously pneumocephalus can occur in scuba diving but is very rare in this context if there is a valve mechanism which allows air to enter the skull but prevents it from escaping a tension pneumocephalus can occur similar to what can happen in a tension pneumothorax ct scans of patients with a tension pneumocephalus typically show air that compresses the frontal lobes of the brain which results in a tented appearance of the brain in the skull known as the mount fuji sign the name is derived from the resemblance of the brain to mount fuji in japan a volcano known for its symmetrical cone in typical cases there is a symmetrical depression near the midline such as the crater of a volcano due to intact bridging veins its occurrence seems to be limited to tension pneumocephalus not occurring in pneumocephalus without tension the sign was first described by a team of japanese neurosurgeons pneumocephalus has also been shown to follow neurosurgical procedures such as deep brain stimulation where while seemingly innocuous to the patient may cause brain shift and subsequent stereotactic inaccuracy efforts are made by neurosurgeons to reduce pneumocephalus volume during surgery and thus subsequent brain shift
pneumococcal infection is an infection of the bacterium streptococcus pneumoniae
pneumococcal pneumonia is a type of bacterial pneumonia that is specifically caused by streptococcus pneumoniae s pneumoniae is also called pneumococcus it is the most common bacterial pneumonia found in adults the estimated number of americans with pneumococcal pneumonia is 900 000 annually with almost 400 000 cases hospitalized and fatalities accounting for 5 7 of these cases the symptoms of pneumococcal pneumonia can occur suddenly typically presenting as a severe chill later including a severe fever cough shortness of breath rapid breathing and chest pains other symptoms like nausea vomiting headache fatigue and muscle aches could also accompany the original symptoms sometimes the coughing can produce rusty or blood streaked sputum in 25 of cases a parapneumonic effusion may occur chest x rays will typically show lobar consolidation or patchy infiltrates in most cases once pneumococcal pneumonia has been identified doctors will prescribe antibiotics these antibiotic usually help alleviate and eliminate symptoms between 12 and 36 hours after being taken despite most antibiotics effectiveness in treating the disease sometimes the bacteria can resist the antibiotics causing symptoms to worsen additionally age and health of the infected patient can contribute to the effectiveness of the antibiotics a vaccine has also been developed for the prevention of pneumococcal pneumonia recommended to children under age five as well as adults over the age of 65 while it has been commonly known that the influenza virus increases one s chances of contracting pneumonia or meningitis caused by the streptococcus pneumonaie bacteria new medical research in mice indicates that the flu is actually a necessary component for the transmission of the disease researcher dimitri diavatopoulo from the radboud university nijmegen medical centre in the netherlands describes his observations in mice stating that in these animals the spread of the bacteria only occurs between animals already infected with the influenza virus not between those without it he says that these findings have only been inclusive in mice however he believes that the same could be true for humans
pneumoconiosis is an occupational lung disease and a restrictive lung disease caused by the inhalation of dust often in mines and from agriculture in 2013 it resulted in 260 000 deaths up from 251 000 deaths in 1990 of these deaths 46 000 were due to silicosis 24 000 due to asbestosis and 25 000 due to coal workers pneumoconiosis
pneumocystis pneumonia pcp is a form of pneumonia caused by the yeast like fungus pneumocystis jirovecii pneumocystis pneumonia is not commonly found in the lungs of healthy people but being a source of opportunistic infection it can cause a lung infection in people with a weak immune system pneumocystis pneumonia is especially seen in people with cancer undergoing chemotherapy hiv aids and the use of medications that suppress the immune system
pneumocystosis is an infection by pneumocystis jirovecii that primarily occurs as a pulmonary infection aids patients with extrapulmonary involvement being uncommon but if occurring in the skin presenting most often as nodular growths in the auditory canal
pneumocytic hyperplasia is an hyperplasia of pneumocytes lining pulmonary alveoli
pneumomediastinum from greek pneuma air also known as mediastinal emphysema is pneumatosis abnormal presence of air or other gas in the mediastinum first described in 1819 by rené laennec the condition can result from physical trauma or other situations that lead to air escaping from the lungs airways or bowel into the chest cavity
pneumonia is an inflammatory condition of the lung affecting primarily the microscopic air sacs known as alveoli typical signs and symptoms include a varying severity and combination of productive or dry cough chest pain fever and trouble breathing depending on the underlying cause pneumonia is usually caused by infection with viruses or bacteria and less commonly by other microorganisms certain medications and conditions such as autoimmune diseases risk factors include other lung diseases such as cystic fibrosis copd and asthma diabetes heart failure a history of smoking a poor ability to cough such as following a stroke or a weak immune system diagnosis is often based on the symptoms and physical examination chest x ray blood tests and culture of the sputum may help confirm the diagnosis the disease may be classified by where it was acquired with community hospital or health care associated pneumonia vaccines to prevent certain types of pneumonia are available other methods of prevention include handwashing and not smoking treatment depends on the underlying cause pneumonia believed to be due to bacteria is treated with antibiotics if the pneumonia is severe the affected person is generally hospitalized oxygen therapy may be used if oxygen levels are low pneumonia affects approximately 450 million people globally 7 of the population and results in about 4 million deaths per year pneumonia was regarded by william osler in the 19 th century as the captain of the men of death with the introduction of antibiotics and vaccines in the 20 th century survival improved nevertheless in developing countries and among the very old the very young and the chronically ill pneumonia remains a leading cause of death pneumonia often shortens suffering among those already close to death and has thus been called the old man s friend
pneumonia is an illness which can result from a variety of causes including infection with bacteria viruses fungi or parasites pneumonia can occur in any animal with lungs including mammals birds and reptiles symptoms associated with pneumonia include fever fast or difficult breathing nasal discharge and decreased activity different animal species have distinct lung anatomy and physiology and are thus affected by pneumonia differently differences in anatomy immune systems diet and behavior also affects the particular microorganisms commonly causing pneumonia diagnostic tools include physical examination testing of the sputum and x ray investigation treatment depends on the cause of pneumonia bacterial pneumonia is treated with antibiotics see also pneumonia pneumonic
pneumonic plague a severe type of lung infection is one of three main forms of plague all of which are caused by the bacterium yersinia pestis it is more virulent and rarer than bubonic plague the difference between the versions of plague is simply the location of the infection in the body the bubonic plague is an infection of the lymphatic system the pneumonic plague is an infection of the respiratory system and the septicemic plague is an infection in the blood stream typically the pneumonic form is due to a spread from infection of an initial bubonic form primary pneumonic plague results from inhalation of fine infective droplets and can be transmitted from human to human without involvement of fleas or animals untreated pneumonic plague has a mortality rate from 90 100
pneumonitis or pulmonitis is an inflammation of lung tissue many factors can cause pneumonitis including breathing in animal dander aspiration inhaling small food particles or vomit down the wrong pipe and receiving radiation therapy to the chest pneumonitis was listed as the one of the top 15 leading causes of death at number 15 in the united states as of 2010 overtaking homicide which dropped off the list this was due to a number of factors including an increase in the population of people over 75 for whom pneumonitis is a common cause of death pneumonia is pneumonitis combined with consolidation and exudation due to infection
pneumonolysis is the separation of an adherent lung from the pleura to permit collapse of the lung it was formerly used to treat tuberculosis
pneumoparotitis also termed pneumosialadenitis wind parotitis surgical mumps or anaesthesia mumps is a rare cause of parotid gland swelling which occurs when air is forced through the parotid stenson duct resulting in inflation of the duct
pneumopericardium is a medical condition where air enters the pericardial cavity this condition has been recognized in preterm neonates in which it is associated with severe lung pathology after vigorous resuscitation or in the presence of assisted ventilation this is a serious complication which if untreated may lead to cardiac tamponade and death pneumomediastinum which is the presence of air in the mediastinum may mimic and also coexist with pneumopericardium it can be congenital or introduced by a wound
pneumoperitoneum is pneumatosis abnormal presence of air or other gas in the peritoneal cavity a potential space within the abdominal cavity when present it can often be seen on radiography but small amounts are often missed and ct scan is nowadays regarded as a criterion standard in the assessment of a pneumoperitoneum ct can visualize quantities as small as 5 cm ³ of air or gas the most common cause is a perforated abdominal viscus generally a perforated peptic ulcer although any part of the bowel may perforate from a benign ulcer tumor or abdominal trauma a perforated appendix seldom causes a pneumoperitoneum in the mid twentieth century an artificial pneumoperitoneum was sometimes intentionally administered as a treatment for a hiatal hernia this was achieved by insufflating the abdomen with carbon dioxide the practice is currently used by surgical teams in order to perform laparoscopic surgery
pneumoscrotum is a rare medical condition in which gas accumulates in the scrotum it has a variety of possible causes
pneumosinus dilatans is a condition consisting of abnormal expansion or dilatation of one or more paranasal sinuses it most often affects the frontal sinus and can cause damage to vision due to pressure on the nearby optic nerve the preferred treatment is endoscopic surgery to deflate the sinus
a pneumothorax is an abnormal collection of air in the pleural space that causes an uncoupling of the lung from the chest wall like a pleural effusion liquid buildup in that space a pneumothorax may interfere with normal breathing symptoms typically include chest pain and shortness of breath it is often called a collapsed lung although that term may also refer to atelectasis one or both lungs may be affected a primary pneumothorax is one that occurs without an apparent cause and in the absence of significant lung disease while a secondary pneumothorax occurs in the presence of existing lung disease a pneumothorax can be caused by physical trauma to the chest including a blast injury or as a complication of a healthcare intervention in which case it is called a traumatic pneumothorax in a minority of cases the amount of air in the chest increases markedly when a one way valve is formed by an area of damaged tissue leading to a tension pneumothorax this condition can cause a steadily worsening oxygen shortage and low blood pressure unless reversed by effective treatment it can result in death diagnosis of a pneumothorax by physical examination alone can be difficult particularly in smaller pneumothoraces a chest x ray computed tomography ct scan or ultrasound is usually used to confirm its presence small spontaneous pneumothoraces typically resolve without treatment and require only monitoring this approach may be most appropriate in people who have no underlying lung disease in a larger pneumothorax or when there are marked symptoms the air may be removed with a syringe or a chest tube connected to a one way valve system occasionally surgery may be required if tube drainage is unsuccessful or as a preventive measure if there have been repeated episodes the surgical treatments usually involve pleurodesis in which the layers of pleura are induced to stick together or pleurectomy the surgical removal of pleural membranes
pobiti kamani bulgarian побити камъни also known as the stone desert is a desert like rock phenomenon located on the north west varna province border in bulgaria it is considered the only desert in bulgaria and one of few found in europe the desert consists of sand dunes and several groups of natural rock formations on a total area of 13 km ² the formations are mainly stone columns between 5 and 7 meters high and from 0 3 to 3 meters thick the columns do not have solid foundations but are instead hollow and filled with sand and look as if they were stuck into the surrounding sand which gives the phenomenon its name sandstorms and sand twisters have also been known to commonly occur in this desert region of bulgaria the stone desert is not only a well known european tourist attraction due to its desert like habitat but it is one of few places where desert type vegetation such as cactus are known to grow it is also the only desert in europe in which desert reptilians and other desert type animalia are found to thrive the stone desert along with the tabernas desert of spain is one of two naturally formed deserts in all of europe and the only known naturally formed desert in eastern europe in order to be preserved pobiti kamani the stone desert was designated a natural landmark in the late 1930 s there are a number of theories regarding the phenomenon s origin the pioneering hypothesis can be divided roughly into two groups suggesting an organic or abiotic origin according to the former the formations are the result of coral activity but detail investigation shows no coral while the latter explain the phenomenon with the prismatic weathering and desertification of the rocks the formation of sand and limestone concretions or lower eocene bubbling reefs based on a petrographic and stable isotope geochemical study and field observations evidence exists that these structures represent an exceptionally record of paleo hydrocarbon seep system low magnesium calcite cements are strongly depleted in heavy carbon isotope 13 c the pathways of fluid circulation are recorded as columns set in sands which columns after recent sand removal gave desert like landscape the dynamic reconstruction of the origin of these structures the processes of fluid migration and microbial mediation of hydrocarbon oxidation leading to carbonate precipitation have been studied by de boever et al 2009
podoconiosis also known as nonfilarial elephantiasis is a disease of the lymph vessels of the lower extremities that is caused by chronic exposure to irritant soils it is the second most common cause of tropical lymphedema after filariasis and it is characterized by prominent swelling of the lower extremities which leads to disfigurement and disability
poetic contractions are archaic and obsolete contractions of words not commonly used today in modern english but are still found used extensively in early modern english poetry particular that of william shakespeare the extent to which the usage of poetic contractions really helps with matching poetic meters is negligible and modern readers prefer to substitute the contractions with the actual words they imply for clarity rather than adhere to obsolete words for the purpose of archaic nostalgia in the modern english of today poetic contractions tend to sound unsophisticated poor and uneducated to modern readers since contracted words are most often used in modern english to indicate colloquy accidents of poor country folks for example the colloquial english in the writings of mark twain
pogosta disease is a viral disease established to be identical with other diseases karelian fever and ockelbo disease the names are derived from the words pogosta karelia and ockelbo respectively the symptoms of the disease include usually rash as well as mild fever and other flu like symptoms in most cases the symptoms last less than 5 days however in some cases the patients develop a painful arthritis there are no known chemical agents available to treat the disease it has long been suspected that the disease is caused by a sindbis like virus a positive stranded rna virus belonging to the alphavirus genus and family togaviridae in 2002 a strain of sindbis was isolated from patients during an outbreak of the pogosta disease in finland confirming the hypothesis this disease is mainly found in the eastern parts of finland a typical pogosta disease patient is a middle aged person who has been infected through a mosquito bite while picking berries in the autumn the prevalence of the disease is about 100 diagnosed cases every year with larger outbreaks occurring in 7 year intervals
poikilocytosis refers to the presence of poikilocytes in the blood poikilocytes are abnormally shaped red blood cells as seen on a blood film in humans and many wild and domestic species of animals though they are common in some clinically normal small ruminants particularly goats normal red blood cells are round flattened disks that are thinner in the middle than at the edges a poikilocyte is an abnormally shaped cell generally poikilocytosis can refer to an increase in abnormal red blood cells of any shape where they make up 10 or more of the total population
poikiloderma is a skin condition that consists of areas of hypopigmentation hyperpigmentation telangiectasias and atrophy poikiloderma is most frequently seen on the chest or the neck characterized by red colored pigment on the skin that is commonly associated with sun damage
poikiloderma of civatte is a cutaneous condition and refers to reticulated red to red brown patches with telangiectasias it is identifiable as the reddish brown discoloration on sides of the neck usually on both sides it is more common with women than men and more commonly effects middle aged to elderly women poikiloderma is basically a change of the skin due to dilation of the blood vessels in the neck civatte was the french dermatologist who first identified it in the 1920 s
poikiloderma vasculare atrophicans pva sometimes referred to as parapsoriasis variegata or parapsoriasis lichenoides is a cutaneous condition skin disease characterized by hypo or hyperpigmentation diminished or heightened skin pigmentation respectively telangiectasia and skin atrophy other names for the condition include prereticulotic poikiloderma and atrophic parapsoriasis the condition was first described by pioneer american pediatrician abraham jacobi in 1906 pva causes areas of affected skin to appear speckled red and inflamed yellowish and or brown gray or grayish black with scaling and a thinness that may be described as cigarette paper on the surface of the skin these areas may range in size from small patches to plaques larger raised areas to neoplasms spreading tumor like growths on the skin mycosis fungoides a type of skin lymphoma may be a cause of pva the condition may also be caused by associated with or accompany any of the following conditions or disorders other skin lymphomas dermatomyositis lupus erythematosus rothmund thompson syndrome kindler syndrome dyskeratosis congenita and chronic radiodermatitis rare causes include arsenic ingestion and the condition can also be idiopathic pva may be considered a rare variant of cutaneous t cell lymphoma a non hodgkin s form of lymphoma affecting the skin it may also be included among a number of similar conditions that are considered as precursors to mycosis fungoides pva is believed to be a syndrome closely associated with large plaque parapsoriasis and its cohort retiform parapsoriasis including pva all three conditions fit within an updated view of the once ambiguous classification scheme known as parapsoriasis
poisson clumping or poisson bursts is the phenomenon wherein random events have a tendency to occur in clusters clumps or bursts
poland syndrome is a rare birth defect characterized by underdevelopment or absence of the chest muscle pectoralis on one side of the body and usually also webbing of the fingers cutaneous syndactyly of the hand on the same side the ipsilateral hand in most affected individuals the missing part is the large section of the muscle that normally attaches to the upper arm on one side and the breastbone sternum on the other other abnormalities may occur on the affected side of the torso in some cases additional muscles in the chest wall side and shoulder are missing or underdeveloped there may also be rib cage abnormalities such as shortened ribs and the ribs may be noticeable due to less fat under the skin subcutaneous fat breast and nipple abnormalities may also occur and underarm axillary hair is sometimes sparse or abnormally placed in most cases the abnormalities in the chest area do not cause health problems or affect movement poland syndrome most often affects the right side of the body and occurs more often in males than in females it is usually considered a unilateral condition some have claimed that the term can be applied in bilateral presentation but others recommend using alternate terminology in those cases
polar t 3 syndrome is a condition found in polar explorers caused by a reduction in levels of the thyroid hormone t 3 its effects include forgetfulness cognitive impairment and mood disturbances it can exhibit itself in a fugue state known as the antarctic stare it is regarded as one of the contributory causes of winter over syndrome
polar amplification is the phenomenon that any change in the net radiation balance for example greenhouse intensification tends to produce a larger change in temperature near the poles than the planetary average on a planet with an atmosphere that can restrict longwave radiation to space a greenhouse effect surface temperatures will be warmer than a simple planetary equilibrium temperature calculation would predict where the atmosphere or an extensive ocean is able to convect heat polewards the poles will be warmer and equatorial regions cooler than their local net radiation balances would predict in the extreme the planet venus is thought to have experienced a very large increase in greenhouse effect over its lifetime so much so that its poles have warmed sufficiently to render its surface temperature effectively isothermal no difference between poles and equator on earth water vapor and trace gasses provide a lesser greenhouse effect and the atmosphere and extensive oceans provide efficient poleward heat transport both palaeoclimate changes and recent global warming changes have exhibited strong polar amplification as described below
polar drift is a geological phenomenon caused by variations in the flow of molten iron in earth s outer core resulting in changes in the orientation of earth s magnetic field and hence the position of the magnetic north and south poles the magnetic north pole is approximately 965 kilometers from the geographic north pole the pole drifts considerably each day and since 2007 it moves about 55 to 60 km per year as a result of this phenomenon
the polar effect or electronic effect in chemistry is the effect exerted by a substituent on modifying electrostatic forces operating on a nearby reaction center the main contributors to the polar effect are the inductive effect mesomeric effect and the through space electronic field effect an electron withdrawing group or ewg draws electrons away from a reaction center when this center is an electron rich carbanion or an alkoxide anion the presence of the electron withdrawing substituent has a stabilizing effect examples of electron withdrawing groups are halogens f cl nitriles cn carbonyls rcor nitro groups no 2 an electron releasing group or erg may also be called electron donating groups or edg s releases electrons into a reaction center and as such stabilizes electron deficient carbocations examples of electron releasing groups are alkyl groups alcohol groups amino groups the total substituent effect is the combination of the polar effect and the combined steric effects in electrophilic aromatic substitution and nucleophilic aromatic substitution substituents are divided into activating groups and deactivating groups where the direction of activation or deactivation is also taken into account
polar mesospheric summer echoes pmse is the phenomenon of anomalous radar echoes found between 80 90 km in altitude from may through early august in the arctic and from november through to february in the antarctic these strong radar echoes are associated with the extremely cold temperatures that occur above continental antarctica during the summer rocket and radar measurements indicate that a partial reflection from a multitude of ion layers and constructive interference causes at least some of the pmse generally pmse exhibits dramatic variations in height and intensity as well as large variations in doppler shift pmse exhibit strong signal power enhancements of scattering cross section at vhf radar frequencies in the range 50 mhz to 250 mhz at times even to over 1 ghz that occur in summer at high latitudes the peak pmse height is slightly below the summer mesopause temperature minimum at 88 km and above the noctilucent cloud nlc and or polar mesospheric cloud pmc layer at 83 – 84 km the usual instrument for observing pmse is the a vhf mesosphere stratosphere troposphere mst radar although lidars and sounding rockets have also been used pmse is believed to be caused by structural irregularities in the ionospheric electron density at lower altitudes the exact cause of pmse is not yet known although theorists have proposed steep electron density gradients heavy positive ions dressed aerosols gravity waves and turbulence as possible explanations pmse occurs in both the arctic and antarctic regions and is sometimes accompanied by noctilucent clouds
the polar see saw also bipolar seesaw is the phenomenon that temperature changes in the northern and southern hemispheres may be out of phase the theory or hypothesis states that large changes f e when the glaciers are intensely growing or depleting in the formation of ocean bottom water in both poles take a long time to exert their effect in the other hemisphere estimates of the period of delay vary one typical estimate is 1500 years this is usually studied in the context of ice cores taken from antarctica and greenland
polarizability is the ability to form instantaneous dipoles it is a property of matter polarizabilities determine the dynamical response of a bound system to external fields and provide insight into a molecule s internal structure
polarization is an important phenomenon in astronomy the polarization of starlight was first observed by the astronomers william hiltner and john s hall in 1949 subsequently jesse greenstein and leverett davis jr developed theories allowing the use of polarization data to trace interstellar magnetic fields though the integrated thermal radiation of stars is not usually appreciably polarized at source scattering by interstellar dust can impose polarization on starlight over long distances net polarization at the source can occur if the photosphere itself is asymmetric due to limb polarization plane polarization of starlight generated at the star itself is observed for ap stars peculiar a type stars both circular and linear polarization of light from the sun has been measured circular polarization is mainly due to transmission and absorption effects in strongly magnetic regions of the sun s surface another mechanism that gives rise to circular polarization is the so called alignment to orientation mechanism continuum light is linearly polarized at different locations across the face of the sun limb polarization though taken as a whole this polarization cancels linear polarization in spectral lines is usually created by anisotropic scattering of photons on atoms and ions which can themselves be polarized by this interaction the linearly polarized spectrum of the sun is often called the second solar spectrum atomic polarization can be modified in weak magnetic fields by the hanle effect as a result polarization of the scattered photons is also modified providing a diagnostics tool for understanding stellar magnetic fields polarization is also present in radiation from coherent astronomical sources e g hydroxyl or methanol masers and incoherent sources such as the large radio lobes in active galaxies and pulsar radio radiation which may it is speculated sometimes be coherent apart from providing information on sources of radiation and scattering polarization also probes the interstellar magnetic field in our galaxy as well as in radio galaxies via faraday rotation in some cases it can be difficult to determine how much of the faraday rotation is in the external source and how much is local to our own galaxy but in many cases it is possible to find another distant source nearby in the sky thus by comparing the candidate source and the reference source the results can be untangled the polarization of the cosmic microwave background cmb is also being used to study the physics of the very early universe cmb exhibits 2 components of polarization b mode divergence free like magnetic field and e mode curl free gradient only like electric field polarization the bicep 2 telescope located at the south pole helped in the detection of b mode polarization in the cmb the polarization modes of the cmb may provide more information about the influence of gravitational waves on the development of the early universe it has been suggested that astronomical sources of polarised light caused the chirality found in biological molecules on earth
pole splitting is a phenomenon exploited in some forms of frequency compensation used in an electronic amplifier when a capacitor is introduced between the input and output sides of the amplifier with the intention of moving the pole lowest in frequency usually an input pole to lower frequencies pole splitting causes the pole next in frequency usually an output pole to move to a higher frequency this pole movement increases the stability of the amplifier and improves its step response at the cost of decreased speed
police psychology is a subfield of forensic psychology addressing issues specific to police personnel and other public safety workers
polioencephalitis is a viral infection of the brain causing inflammation within the grey matter of the brain stem the virus has an affinity for neuronal cell bodies and has been found to affect mostly the midbrain pons medulla and cerebellum of most infected patients the infection can reach up through the thalamus and hypothalamus and possibly reach the cerebral hemispheres the infection is caused by the poliomyelitis virus which is a single stranded rna virus surrounded by a non enveloped capsid humans are the only known natural hosts of this virus the disease has been eliminated from the u s since the mid twentieth century but is still found in certain areas of the world such as africa
poliomyelitis often called polio or infantile paralysis is an infectious disease caused by the poliovirus in about 0 5 of cases there is muscle weakness resulting in an inability to move this can occur over a few hours to few days the weakness most often involves the legs but may less commonly involve the muscles of the head neck and diaphragm many but not all people fully recover in those with muscle weakness about 2 to 5 of children and 15 to 30 of adults die another 25 of people have minor symptoms such as fever and a sore throat and up to 5 have headache neck stiffness and pains in the arms and legs these people are usually back to normal within one or two weeks in up to 70 of infections there are no symptoms years after recovery post polio syndrome may occur with a slow development of muscle weakness similar to that which the person had during the initial infection poliovirus is usually spread from person to person through infected fecal matter entering the mouth it may also be spread by food or water containing human feces and less commonly from infected saliva those who are infected may spread the disease for up to six weeks even if no symptoms are present the disease may be diagnosed by finding the virus in the feces or detecting antibodies against it in the blood the disease only occurs naturally in humans the disease is preventable with the polio vaccine however a number of doses are required for it to be effective the us centers for disease control and prevention recommends polio vaccination boosters for travelers and those who live in countries where the disease is occurring once infected there is no specific treatment in 2015 polio affected less than 100 people down from 350 000 cases in 1988 in 2014 the disease was only spreading between people in afghanistan nigeria and pakistan in 2015 nigeria had stopped the spread of wild poliovirus but it reoccurred in 2016 poliomyelitis has existed for thousands of years with depictions of the disease in ancient art the disease was first recognized as a distinct condition by michael underwood in 1789 and the virus that causes it was first identified in 1908 by karl landsteiner major outbreaks started to occur in the late 19 th century in europe and the united states in the 20 th century it became one of the most worrying childhood diseases in these areas the first polio vaccine was developed in the 1950 s by jonas salk it is hoped that vaccination efforts and early detection of cases will result in global eradication of the disease by 2018
poliosis also called poliosis circumscripta is the decrease or absence of melanin or color in head hair eyebrows eyelashes or any other hairy area this condition can cause single or less commonly multiple white patches on the hair some mistake these white patches for simple birth marks in poliosis there is decreased or absent melanin in the hair bulbs of affected hair follicles the melanocytes of the skin are usually not affected poliosis occurs in several genetic syndromes such as piebaldism waardenburg syndrome neurofibromatosis type i and tuberous sclerosis it can also occur in conditions such as vitiligo vogt – koyanagi – harada disease alopecia areata sarcoidosis and in association with neoplasms and some medications it can give rise to a mallen streak that can be hereditary catherine cookson wrote a novel and later a tv series called the mallen streak where a family had the condition sports presenter dickie davies and runner sam brown were famous for this feature
a polishing hologram is a visible pattern of damage to a polished surface it is caused by small scratches to the surface which result in light being refracted creating a pattern which appears to float deep beneath the surface
a political gaffe is an error made by a politician that is reported to the public when made by a politician who is campaigning for office or party leadership gaffes can affect standings in polls while in office the opposition can refer to them in governmental debates over policy gaffes can be classified in different types gaffes can be overplayed by the media as side stories to more important issues at the time gaffe is of french origin originally a boat hook as in gaff rig where the relation is apparent but the sense association to a blundering remark is obscure
political lesbianism is a phenomenon within feminism primarily second wave feminism and radical feminism it includes but is not limited to lesbian separatism political lesbianism embraces the theory that sexual orientation is a political and feminist choice and advocates lesbianism as a positive alternative to heterosexuality for women as part of the struggle against sexism
political methodology is a subfield of political science that studies the quantitative methods used to study politics it combines statistics mathematics and formal theory political methodology is often used for positive research in contrast to normative research it is similar to econometrics
political psychological rationalization ppr is a phenomenon seen in political warfare and election campaign rhetoric meant to displace a perceived fault short coming mistake or problem from one political actor and attach it to another political actor generally an opponent while not truly rationalization in the context of psychology — where a problem short coming mistake or fault is justified and allowed to endure — ppr maintains the negative connotation of the original flaw transfers that connotation to a target actor and then seeks to destroy the flaw and consequently the actor through association with said flaw but with a political purpose and focus political psychological rationalization exploits a number of psychological principles to manipulate the perceptions of different actors including groupthink cognitive dissonance and other forms of psychological manipulation an example of ppr would be candidate a accusing candidate b of having an onerous tax policy for not cutting taxes while candidate a had already raised taxes previously in his or her career but having accused candidate b of having an onerous tax policy is seen as being in favor of cutting taxes use of ppr can also run the risk of backfiring against the broadcaster if knowledge of hypocritical behavior on the part of the displacing political actor becomes known in cases where this has happened the original negative association can become reoriented back to the initiating political actor as tool of political warfare ppr has been used by a wide array of factions ideologies actors and regimes including fascists communists religious extremists electoral campaign rhetoric and non governmental organizations
polka dot is a pattern consisting of an array of filled large in size circles it differentiates itself from the spot pattern as polka dots are perfectly even and sized while spots are irregular in spacing and shape early instances were generally equally sized and spaced relatively closely in relation to their diameters and there is speculation that they were originally conceived to cover moth holes in women s wool dresses many modern prints include more randomly spaced sized and coloured dots polka dots are most commonly seen on children s clothing toys and furniture but they appear in a wide array of contexts the pattern rarely appears in formal contexts however and is generally confined to more playful attire such as bathing suits and lingerie occasionally white on black small dots appear on more formal clothing polka dots became common on clothing in the late nineteenth century in the united kingdom
the poll merino is a subtype of the australian merino breed of domestic sheep without horns that was developed in australia
poly drug use refers to the use of two or more psychoactive drugs in combination to achieve a particular effect in many cases one drug is used as a base or primary drug with additional drugs to leaven or compensate for the side effects of the primary drug and make the experience more enjoyable with drug synergy effects or to supplement for primary drug when supply is low
polyamorphism is the ability of a substance to exist in several different amorphous modifications it is analogous to the polymorphism of crystalline materials many amorphous substances can exist with different amorphous characteristics e g polymers however polyamorphism requires two distinct amorphous states with a clear discontinuous first order phase transition between them when such a transition occurs between two stable liquid states a polyamorphic transition may also be referred to as a liquid – liquid phase transition
polyarteritis nodosa also known as panarteritis nodosa periarteritis nodosa kussmaul disease kussmaul maier disease or pan is a systemic vasculitis of small or medium sized muscular arteries typically involving renal and visceral vessels but sparing the pulmonary circulation polyarteritis nodosa may present in infants in polyarteritis nodosa small aneurysms are strung like the beads of a rosary therefore making rosary sign an important diagnostic feature of the vasculitis with treatment five year survival is 80 without treatment five year survival is 13 death is often a consequence of kidney failure myocardial infarction or stroke
polyarthritis is any type of arthritis that involves 5 or more joints simultaneously it is usually associated with autoimmune conditions and may be experienced at any age and is not sex specific
polybus greek πόλυβος fl c 400 bc was one of the pupils of hippocrates and also his son in law he lived on the island of cos in the 4 th century bc with his brothers in law thessalus and draco he was one of the founders of the dogmatic school of medicine he was sent by hippocrates with his fellow pupils during the time of the plague to assist different cities with his medical skill afterwards he remained in his native country according to galen he followed implicitly the opinions and practices of hippocrates but the strict accuracy of this assertion has been doubted he has been supposed by both ancient and modern scholars to be the author of several works in the hippocratic collection possible works include de natura hominis de genitura de natura pueri de salubri victus ratione de affectionibus and de internis affectionibus clement of alexandria attributes to him the treatise de octimestri partu and pseudo plutarch quotes him as the author of de septimestri partu de natura hominis on the nature of man is the earliest known text to advance a four humor system of blood phlegm yellow bile and black bile galen though considers de natura hominis to be the work of hippocrates himself polybus is mentioned many times by galen chiefly in connection with different works in the hippocratic collection he is also mentioned by celsus caelius aurelianus and pliny
polycephaly is the condition of having more than one head the term is derived from the greek stems poly greek πολύ meaning multiple and kephalē greek κεφάλη meaning head a polycephalic organism may be thought of as one being with a supernumerary body part or as two or more beings with a shared body two headed animals called bicephalic or dicephalic and three headed tricephalic animals are the only type of multi headed creatures seen in the real world and form by the same process as conjoined twins from monozygotic twin embryos in humans there are two different forms of twinning that can lead to two heads being supported by a single torso in dicephalus parapagus dipus the two heads are side by side in craniopagus parasiticus the two heads are joined directly to each other but only one head has a functional torso survival to adulthood is rare but does occur in some forms of dicephalus parapagus dipus there are many occurrences of multi headed animals in mythology in heraldry and vexillology the double headed eagle is a common symbol though no such animal is known to have ever existed
polychromasia also known as polychromatophilia is a disorder where there is an abnormally high number of immature red blood cells found in the bloodstream as a result of being prematurely released from the bone marrow during blood formation poly refers to many and chromasia means color these cells are often shades of grayish blue polychromasia is usually a sign of bone marrow stress as well as immature red blood cells 3 types are recognized with types 1 and 2 being referred to as young red blood cells and type 3 as old red blood cells giemsa stain is used to distinguish all three types in blood smears the young cells will generally stain gray or blue in the cytoplasm these young red blood cells are commonly called reticulocytes all polychromatophilic cells are reticulocytes however not all reticulocytes are polychromatophilic in the old blood cells the cytoplasm either stains a light orange or does not stain at all
polychromia is a genetic disorder that results in irregular or excessive coloration of the skin
polycoria is a pathological condition of the eye characterized by more than one pupillary opening in the iris it may be congenital or result from a disease affecting the iris polycoria is extremely rare and other conditions are frequently mistaken for it
in psychology a polycrates complex is a desire to be punished
polycystic kidney disease pkd or pckd also known as polycystic kidney syndrome is a genetic disorder in which abnormal cysts develop and grow in the kidneys cystic disorders can express themselves at any point infancy childhood or adulthood the disease occurs in humans and some other animals pkd is characterized by the presence of multiple cysts hence polycystic typically in both kidneys however 17 of cases initially present with observable disease in one kidney with most cases progressing to bilateral disease in adulthood polycystic kidney disease is one of the most common hereditary diseases in the united states affecting more than 600 000 people it is the cause of nearly 10 of end stage renal disease and affects men women and all races equally
polycystic ovary syndrome pcos is a set of symptoms due to elevated androgens male hormones in women signs and symptoms of pcos include irregular or no menstrual periods heavy periods excess body and facial hair acne pelvic pain difficulty getting pregnant and patches of thick darker velvety skin associated conditions include type 2 diabetes obesity obstructive sleep apnea heart disease mood disorders and endometrial cancer pcos is due to a combination of genetic and environmental factors risk factors include obesity not enough physical exercise and a family history of someone with the condition diagnosis is based on two of the following three findings no ovulation high androgen levels and ovarian cysts cysts may be detectable by ultrasound other conditions that produce similar symptoms include adrenal hyperplasia hypothyroidism and hyperprolactinemia pcos has no cure treatment may involve lifestyle changes such as weight loss and exercise birth control pills may help with improving the regularity of periods excess hair growth and acne metformin and anti androgens may also help other typical acne treatments and hair removal techniques may be used efforts to improve fertility include weight loss clomiphene or metformin in vitro fertilization is used by some in whom other measures are not effective pcos is the most common endocrine disorder among women between the ages of 18 and 44 it affects approximately 2 to 20 of this age group depending on how it is defined it is one of the leading causes of poor fertility the earliest known description of what is now recognized as pcos dates from 1721 in italy
polycythemia also known as polycythaemia or polyglobulia is a disease state in which the proportion of blood volume that is occupied by red blood cells increases blood volume proportions can be measured as hematocrit level a hematocrit of 55 is seen in polycythemia it can be due to an increase in the number of red blood cells absolute polycythemia or to a decrease in the volume of plasma relative polycythemia polycythemia is sometimes called erythrocytosis but the terms are not synonymous because polycythemia refers to any increase in red blood cells whereas erythrocytosis only refers to a documented increase of red cell mass the emergency treatment of polycythemia e g in hyperviscosity or thrombosis is by venesection the removal of blood from the circulation depending on the underlying cause venesection may also be used on a regular basis to reduce the red blood cell count cytostatics busulfan hydroxyurea are sometimes used if venesection is ineffective or contraindicated
polycythemia or polycythaemia see spelling differences vera pv also known as erythremia primary polycythemia vaquez disease osler vaquez disease and polycythemia rubra vera is a neoplasm in which the bone marrow makes too many red blood cells it may also result in the overproduction of white blood cells and platelets most of the health concerns associated with polycythemia vera are caused by the blood being thicker as a result of the increased red blood cells it is more common in the elderly and may be symptomatic or asymptomatic common signs and symptoms include itching pruritus and severe burning pain in the hands or feet that is usually accompanied by a reddish or bluish coloration of the skin patients with polycythemia vera are more likely to have gouty arthritis treatment consists primarily of phlebotomy
polydactyly or polydactylism from greek πολύς polys meaning many and δάκτυλος daktylos meaning finger also known as hyperdactyly is a congenital physical anomaly in humans dogs and cats having supernumerary fingers or toes polydactyly is the opposite of oligodactyly fewer fingers or toes
adsorption of polyelectrolytes on solid substrates is a surface phenomenon where long chained polymer molecules with charged groups dubbed polyelectrolytes bind to a surface that is charged in the opposite polarity on the molecular level the polymers do not actually bond to the surface but tend to stick to the surface via intermolecular forces and the charges created by the dissociation of various side groups of the polymer because the polymer molecules are so long they have a large amount of surface area with which to contact the surface and thus do not desorb as small molecules are likely to do this means that adsorbed layers of polyelectrolytes form a very durable coating due to this important characteristic of polyelectrolyte layers they are used extensively in industry as flocculants for solubilization as supersorbers antistatic agents as oil recovery aids as gelling aids in nutrition additives in concrete or for blood compatibility enhancement to name a few
polyembryoma is a rare very aggressive form of germ cell tumor usually found in the ovaries polyembryoma has features of both yolk sac tumour and undifferentiated teratoma embryonal carcinoma with a characteristic finding of embryoid bodies lying in a loose mesenchymal stroma it has been found in association with klinefelter syndrome
polyembryony is the phenomenon of two or more embryos developing from a single fertilized egg in humans identical twins polyembryony occurs regularly in many plants and animals the nine banded armadillo for instance usually gives birth to four identical young polyembryony is best known among parasitoid insects of the order hymenoptera families encyrtidae dryinidae platygastridae and braconidae the term is also used in botany to describe the phenomenon of two seedlings emerging from one seed in plants polyembryony often gives rise to the enigma of a single offspring the mechanism underlying this phenonomenon is programmed cell death pcd which removes all but one embryo a more striking example of the use of polyembryony as a competitive reproductive tool is found in the parasitoid hymenoptera family encyrtidae the progeny of the splitting embryo develop into at least two forms those that will develop into adults and those that become a type of soldier called precocious larvae these latter larvae patrol the host and kill any other parasitoids they find with the exception of their siblings usually sisters polyembryony also occurs in bryozoa
polyglotism or polyglottism is the ability to master or the state of having mastered multiple languages the word is a synonym of multilingualism but in recent usage polyglot is sometimes used to refer to a person who learns multiple languages as an avocation the term hyperpolyglot was coined in 2008 by linguist richard hudson to describe individuals who speak dozens of languages multilingualism including multilingual societies as well as individuals who speak more than one language is common individual polyglots or hyperpolyglots speak study or use large numbers of languages in rare cases polyglot savants have mental disabilities but are able to learn many languages
polyhydramnios polyhydramnion hydramnios polyhydramnios is a medical condition describing an excess of amniotic fluid in the amniotic sac it is seen in about 1 of pregnancies it is typically diagnosed when the amniotic fluid index afi is greater than 24 cm there are two clinical varieties of polyhydramnios chronic polyhydramnios where excess amniotic fluid accumulates gradually acute polyhydramnios where excess amniotic fluid collects rapidly the opposite to polyhydramnios is oligohydramnios a deficiency in amniotic fluid
polymelia from greek πολυ many plus μέλος plural μέλεα limb is a birth defect involving limbs a type of dysmelia in which the affected individual has more than the usual number of limbs in humans and most land dwelling animals this means having five or more limbs the extra limb is most commonly shrunken and or deformed sometimes an embryo started as conjoined twins but one twin degenerated completely except for one or more limbs which end up attached to the other twin sometimes small extra legs between the normal legs are caused by the body axis forking in the dipygus condition
polymer fume fever or fluoropolymer fever also informally called teflon flu is an inhalation fever caused by the fumes released when polytetrafluoroethylene ptfe known under the trade name teflon reaches temperatures of 300 ° f 149 ° c to 450 ° f 232 ° c when ptfe is heated above 450 ° f 232 ° c the pyrolysis products are different and inhalation may cause acute lung injury symptoms are flu like chills headaches and fevers with chest tightness and mild cough onset occurs about 4 to 8 hours after exposure to the pyrolysis products of ptfe a high white blood cell count may be seen and chest x ray findings are usually minimal the polymer fumes are especially harmful to certain birds whose breathing optimized for rapidity allows toxins which are excluded by human lungs fumes from teflon in very high heat are fatal to parrots as well as some other birds ptfe toxicosis
polymer science or macromolecular science is a subfield of materials science concerned with polymers primarily synthetic polymers such as plastics and elastomers the field of polymer science includes researchers in multiple disciplines including chemistry physics and engineering
polymicrogyria pmg is a condition that affects the development of the human brain by multiple small gyri creating excessive folding of the brain leading to an abnormally thick cortex this abnormality can affect either one region of the brain or multiple regions the time of onset has yet to be identified however it has been found to occur before birth in either the earlier or later stages of brain development early stages include impaired proliferation and migration of neuroblast while later stages show disordered post migration development the symptoms experienced differ depending on what part of the brain is affected there is no specific treatment to get rid of this condition but there are medications that can control the symptoms such a seizures delayed development or weakened muscles as some of the noted effects
in materials science polymorphism is the ability of a solid material to exist in more than one form or crystal structure polymorphism can potentially be found in any crystalline material including polymers minerals and metals and is related to allotropy which refers to chemical elements the complete morphology of a material is described by polymorphism and other variables such as crystal habit amorphous fraction or crystallographic defects polymorphism is relevant to the fields of pharmaceuticals agrochemicals pigments dyestuffs foods and explosives when polymorphism exists as a result of difference in crystal packing it is called packing polymorphism polymorphism can also result from the existence of different conformers of the same molecule in conformational polymorphism in pseudopolymorphism the different crystal types are the result of hydration or solvation this is more correctly referred to as solvomorphism as different solvates have different chemical formulae an example of an organic polymorph is glycine which is able to form monoclinic and hexagonal crystals silica is known to form many polymorphs the most important of which are α quartz β quartz tridymite cristobalite coesite and stishovite a classical example is the pair of minerals calcite and aragonite both forms of calcium carbonate an analogous phenomenon for amorphous materials is polyamorphism when a substance can take on several different amorphous modifications
polymorphous light eruption ple or polymorphic light eruption pmle is a skin condition triggered by sunlight
polymorphous low grade adenocarcinoma often abbreviated plga is a rare asymptomatic slow growing malignant salivary gland tumor it is most commonly found in the palate the name of the tumor derives from the fact that it has a varied microscopic architectural appearance i e it is polymorphous it is non aggressive when compared to other oral cavity tumors i e it is a low grade tumor it forms glands i e it is an adenocarcinoma it affects the minor salivary glands in the area between the hard and the soft palate male to female ratio is 3 1 and the average age is 56 years
polymyalgia rheumatica pmr is a syndrome with pain or stiffness usually in the neck shoulders upper arms and hips but which may occur all over the body the pain can be very sudden or can occur gradually over a period most people with pmr wake up in the morning with pain in their muscles however cases have occurred in which the person has developed the pain during the evenings or has pain and stiffness all day long people who have polymyalgia rheumatica may also have temporal arteritis an inflammation of blood vessels in the face which can cause blindness if not treated quickly the pain and stiffness can result in a lowered quality of life and can lead to depression polymyalgia rheumatica is often seen in association with temporal arteritis it is thought to be brought on by a viral or bacterial illness or trauma of some kind but genetics does play a factor as well persons of northern european ancestry are much more prone to this illness there is no true and certain laboratory test but c reactive protein crp and erythrocyte sedimentation rate esr can be indicators of inflammation pmr is usually treated with courses of oral corticosteroids most people need to continue the corticosteroid treatment for two to three years pmr sometimes goes away on its own in a year or two but medications and self care measures can improve the rate of recovery pmr was first established as a distinct disease in 1966 by a case report on 11 patients at mount sinai hospital in new york ny it takes its name from the greek word πολυμυαλγία polymyalgia which means pain in many muscles
polymyositis pm inflammation of many muscles is a type of chronic inflammation of the muscles inflammatory myopathy related to dermatomyositis and inclusion body myositis the inflammation is predominantly of the endomysium in polymyositis whereas dermatomyositis is characterized by primarily perimysial inflammation
polyneuropathy poly neuro pathy is damage or disease affecting peripheral nerves peripheral neuropathy in roughly the same areas on both sides of the body featuring weakness numbness and burning pain it usually begins in the hands and feet and may progress to the arms and legs and sometimes to other parts of the body where it may affect the autonomic nervous system it may be acute or chronic a number of different disorders may cause polyneuropathy including diabetes and some types of guillain – barré syndrome
polyostotic fibrous dysplasia also known as albright s disease is a form of fibrous dysplasia affecting more than one bone mccune albright syndrome includes polyostotic fibrous dysplasia as part of its presentation one treatment that has been used is bisphosphonates
a polyp is an abnormal growth of tissue projecting from a mucous membrane if it is attached to the surface by a narrow elongated stalk it is said to be pedunculated if no stalk is present it is said to be sessile polyps are commonly found in the colon stomach nose ear sinus es urinary bladder and uterus they may also occur elsewhere in the body where mucous membranes exist like the cervix vocal folds and small intestine some polyps are tumors neoplasms and others are nonneoplastic for example hyperplastic or dysplastic the neoplastic ones are generally benign although some can be premalignant and or concurrent with a malignancy
a polyphenic trait is a trait for which multiple discrete phenotypes can arise from a single genotype as a result of differing environmental conditions it is therefore a special case of phenotypic plasticity
polypoid melanoma is a rare cutaneous condition a virulent variant of nodular melanoma polypoid melanoma is a subtype of nodular melanoma the most aggressive form of melanoma a skin cancer polypoid melanoma like all types of melanoma starts in the cells that make melanin which is the protective pigment that gives skin color polypoid melanoma is most commonly found on the torso but may be found in unexpected places like the nasal mucous membranes and the rectum sometimes polypoid melanoma may develop on moles on your skin but it usually occurs out of nowhere on normal skin polypoid melanoma can be treated if it s diagnosed early but the disease progresses very rapidly and has a worse prognosis than many other types of melanoma therapies for metastatic melanoma include the biologic immunotherapy agents ipilimumab pembrolizumab and nivolumab braf inhibitors such as vemurafenib and dabrafenib and a mek inhibitor trametinib
polyradiculoneuropathy describes a condition in which polyneuropathy and polyradiculopathy occur together an example is guillain – barré syndrome treatment with a single course of intravenous immunoglobulin ivig infusions has been demonstrated to be a potentially effective treatment reported to have caused prolonged remission in a case associated with systemic lupus systemic lupus erythematosus
polysilicon depletion effect is the phenomenon in which unwanted variation of threshold voltage of the mosfet devices using polysilicon as gate material is observed leading to unpredicted behaviour of the electronic circuit polycrystalline silicon also called polysilicon is a material consisting of small silicon crystals it differs from single crystal silicon used for electronics and solar cells and from amorphous silicon used for thin film devices and solar cells
polysomy is a condition found in many species including fungi plants insects and mammals in which an organism has at least one more chromosome than normal i e there may be three or more copies of the chromosome rather than the expected two copies most eukaryotic species are diploid meaning they have two sets of chromosomes whereas prokaryotes are haploid containing a single chromosome in each cell aneuploids possess chromosome numbers that are not exact multiples of the haploid number and polysomy is a type of aneuploidy a karyotype is the set of chromosomes in an organism and the suffix somy is used to name aneuploid karyotypes this is not to be confused with the suffix ploidy referring to the number of complete sets of chromosomes polysomy is usually caused by non disjunction the failure of a pair of homologous chromosomes to separate during meiosis but may also be due to a translocation mutation a chromosome abnormality caused by rearrangement of parts between nonhomologous chromosomes polysomy is found in many diseases including down syndrome in humans where affected individuals possess three copies trisomy of chromosome 21 polysomic inheritance occurs during meiosis when chiasmata form between more than two homologous partners producing multivalent chromosomes autopolyploids may show polysomic inheritance of all the linkage groups and their fertility may be reduced due unbalanced chromosome numbers in the gametes in tetrasomic inheritance four copies of a linkage group rather than two tetrasomy assort two by two
polysplenia or chaudhrey s disease is a congenital disease manifested by multiple small accessory spleens rather than a single full sized normal spleen polysplenia sometimes occurs alone but it is often accompanied by other developmental abnormalities conditions associated with polysplenia include gastrointestinal abnormalities such as intestinal malrotation or biliary atresia as well as cardiac abnormalities such as dextrocardia
polysyndactyly is an hereditary anatomical malformation combining polydactyly and syndactyly
polyuria ˌpɒliˈjʊəriə is a condition usually defined as excessive or abnormally large production or passage of urine greater than 2 5 or 3 l over 24 hours in adults frequent urination is sometimes included by definition but is nonetheless usually an accompanying symptom increased production and passage of urine may also be termed diuresis polyuria often appears in conjunction with polydipsia increased thirst though it is possible to have one without the other and the latter may be a cause or an effect psychogenic polydipsia may lead to polyuria polyuria is usually viewed as a symptom or sign of another disorder not a disease by itself but it can be classed as a disorder at least when its underlying causes are not clear
pomade acne occurs when some of the pomade that is applied to the scalp is also applied to the forehead and is responsible for the development of multiple closely packed comedones close to the hairline
pomeranchuk cooling is the phenomenon in which liquid helium 3 will cool if it is compressed isentropically when it is below 0 3 k this occurs because helium 3 has the unique property that solidification below 0 3 k requires pressure this can be used to construct a cryogenic cooler
the pomeranz – fritsch reaction also named pomeranz – fritsch cyclization is a name reaction in the organic chemistry it is named after paul fritsch 1859 – 1913 and cäsar pomeranz 1860 – 1926 in general it is a synthesis of isoquinoline
the pompeian styles are four periods which are distinguished in ancient roman mural painting they were originally delineated and described by the german archaeologist august mau 1840 – 1909 from the excavation of wall paintings at pompeii which is one of the largest group of surviving examples of roman frescoes the wall painting styles have allowed art historians to delineate the various phases of interior decoration in the centuries leading up to the eruption of vesuvius in 79 ad which both destroyed the city and preserved the paintings and between stylistic shifts in roman art in the succession of styles there is a reiteration of stylistic themes the paintings also tell a great deal about the prosperity of the area and specific tastes during the times the main purpose of these frescoes was to reduce the claustrophobic interiors of roman rooms which were windowless and dark the paintings full of color and life brightened up the interior and made the room feel more spacious
in mathematical analysis a pompeiu derivative is a real valued function of one real variable that is the derivative of an everywhere differentiable function and that vanishes in a dense set in particular a pompeiu derivative is discontinuous at any point where it is not 0 whether non identically zero such functions may exist was a problem that arose in the context of early 1900 s research on functional differentiability and integrability the question was affirmatively answered by dimitrie pompeiu by constructing an explicit example these functions are therefore named after him
pompey s campaign in iberia and albania georgian პომპეუსის ლაშქრობა საქართველოში took place in 65 bc and was a consequence of the mithridatic wars rome sought to expand its borders and establish itself as a hegemon of the middle east after mostly subjugating the kingdom of pontus and the kingdom of armenia romans turned to the iberian kingdom whose king artag was an ally of pontus the roman general lucullus lead the campaigns from 74 bc to 66 bc when the roman senate determined that he was going to be succeeded by pompey that same year pompey effectively defeated the armenians and pontians with their king mithridates escaping to colchis after that the attention of romans became increasingly focused on iberia and albania pompey made preparations for the conquest of both the iberian and albanian kingdoms fearing the imminent invasion artag turned to diplomacy and promised the roman envoys unconditional friendship pompey accepted these terms but because he was alerted that the iberians were secretly planning an attack in the spring of 65 bc he immediately marched his forces to iberia artag unaware of this was surprised by the romans and learned this too late to react adequately pompey s forces besieged the fortress of armazi artag panicked fled the castle and took shelter on the left bank of mtkvari river he also burned the bridge over the river to ensure that the romans wouldn t capture him armazi fell and pompey subjugated the right bank artag requested a truce while promising the romans that he would restore the bridge and supply them with food artag stayed true to his words but upon restoring the bridge pompey crossed it with his forces in attempt to seize the king artag again fled with his forces withdrew to the aragvi river and burned a bridge in the same manner some of the iberian militants hid in the woods and fought the roman forces like partisans shooting down arrows from the trees killing any passing roman soldiers reportedly a sizeable number of women also participated in this irregular warfare they were defeated when pompey s forces cut down some of the forest and then burned the rest to the ground pompey pursued artag into the centre of iberia and brought him to battle near the river pelorus artag s main strength lay in his archers but using tactics reminiscent of the athenians at the battle of marathon pompey disabled them by means of a rapid infantry charge which brought his legionaries to close quarters before the enemy fire could take effect greek historian plutarch called this battle a great battle and noted that iberian casualties consisted of approximately 9 000 people while more than 10 000 were taken captive by the romans the iberians finally lost the war and their king was forced to turn to diplomacy once more he sent invaluable objects made of gold to pompey and asked for truce pompey demanded artag s children as hostages and as artag was taking too much time to think it over led his soldiers to aragvi and crossed it so that he left artag no choice he submitted gave his children as hostages and signed the peace with the romans kingdom of iberia was to be a friend and ally of the roman republic and accepted the terms of vassalage after subduing iberia pompey headed towards the kingdom of colchis and subjugated the main fortresses and various local peoples on the way to both cunning diplomacy and the use of force he met up with the roman fleet in phasis and commanded them to capture mithridates while he returned to rome pompey gave the rule of colchis to aristarches effectively making it a roman province part of bithynia et pontus