livescience--2020-09-22--Mysterious Mexican wreck was an illegal slave ship

A sunken ship discovered near Sisal , Mexico , holds the secrets of a 19th-century tragedy .
Three years after the ship 's discovery , archaeologists have confirmed its identity as an illegal slave vessel .
The steamer was carrying Mayan captives to work as slaves in the brutal sugarcane fields of Cuba in 1861 , months after the forced removal of from Mexico had been made illegal .
The ship caught fire and sank , killing dozens of passengers and crew and an unknown number of enslaved Maya .
According to the National Institute of Anthropology and History ( @ @ @ @ @ @ @ Unión was first discovered 2 nautical miles ( 3.7 kilometers ) from the Yucatecan port of Sisal in 2017 .
At first , the identity of the wreck was a mystery ; archaeologists dubbed it `` Adalio '' after the grandfather of the fisherman Juan Diego Esquivel , who introduced the archaeologists to the site .
Related : The 25 most mysterious archaeological finds on Earth It took three years to map , analyze and identify the wreck .
Archaeologists recognized that the ship 's boilers and paddle wheels were a type of @ @ @ @ @ @ @ 1837 and 1860 .
They also found pieces of glass bottles , ceramics and brass cutlery amid the wreckage .
The next step was a historical detective mission .
The researchers searched the archives of Yucatán , Baja California Sur , Cuba , Spain and Mexico to find a ship that would have been in that area and matched the description of the wreck .
La Unión proved to be a match .
The steamer was owned by a Spanish company called Zangroniz Hermanos y Compañía , which began trading between Havana , @ @ @ @ @ @ @ in 1854 .
Officially , the ship carried paying passengers and merchandise such as tanned hides .
But the ship also had a darker purpose .
Related : 17 mysterious shipwrecks you can see on Google Earth In October 1860 , La Unión was caught in Campeche , Mexico , carrying 29 Maya , the native people of Central America who were conquered by the Spanish in the 1600s .
Following the conquest , the Maya and other Indigenous people were often enslaved on plantations , especially those specializing in sugarcane and coffee @ @ @ @ @ @ @ included children as young as 7 .
Slavery was abolished in Mexico in 1829 .
In May 1861 , Mexican president Benito Juárez banned the forcible removal of Indigenous people for sale in other nations .
But as the story of La Unión shows , the slave trade continued .
`` Each slave was sold to middlemen for 25 pesos , and they resold them in Havana for as much as 160 pesos , for men , and 120 pesos for women , '' INAH archaeologist Helena Barba Meinecke .
This human trafficking @ @ @ @ @ @ @ War , a clash between Indigenous peoples and the upper classes of Spanish descent , who were levying heavy taxes and seizing farmland from the Indigenous population .
Captured Mayan combatants were sold into slavery , often in Cuba , according to INAH .
In other cases , slavers called `` enganchadores '' would travel to Indigenous villages and promise citizens that in Cuba , they would be given their own land .
Once the villagers reached Cuba , of course , they were instead enslaved .
Historians estimate that La Unión and @ @ @ @ @ @ @ by the same company , smuggled 25 to 30 people to Cuba each month between 1855 and 1861 .
On Sept. 19 , 1861 , La Unión 's boilers exploded , setting the steamer aflame .
Half of the 80 crew members and 60 paying passengers aboard died .
No one knows how many Mayan captives lost their lives , as they were listed as cargo rather than passengers .
The conflagration did draw attention to the illicit human trafficking that was occurring right under the Mexican government 's nose , according to @ @ @ @ @ @ @ Unión , the government increased searches at Mexican ports to stop the transport of enslaved people .

A sunken ship discovered near Sisal, Mexico, holds the secrets of a 19th-century tragedy.
Three years after the ship's discovery, archaeologists have confirmed its identity as an illegal slave vessel. The steamer was carrying Mayan captives to work as slaves in the brutal sugarcane fields of Cuba in 1861, months after the forced removal of the Maya from Mexico had been made illegal. The ship caught fire and sank, killing dozens of passengers and crew and an unknown number of enslaved Maya.
According to the National Institute of Anthropology and History (INAH), the sunken steamer La Unión was first discovered 2 nautical miles (3.7 kilometers) from the Yucatecan port of Sisal in 2017. At first, the identity of the wreck was a mystery; archaeologists dubbed it "Adalio" after the grandfather of the fisherman Juan Diego Esquivel, who introduced the archaeologists to the site.
Related: The 25 most mysterious archaeological finds on Earth
Shipwreck detectives
It took three years to map, analyze and identify the wreck. Archaeologists recognized that the ship's boilers and paddle wheels were a type of technology that dated to ships built between 1837 and 1860. They also found pieces of glass bottles, ceramics and brass cutlery amid the wreckage.
The next step was a historical detective mission. The researchers searched the archives of Yucatán, Baja California Sur, Cuba, Spain and Mexico to find a ship that would have been in that area and matched the description of the wreck. La Unión proved to be a match.
The steamer was owned by a Spanish company called Zangroniz Hermanos y Compañía, which began trading between Havana, Cuba, and several ports in Mexico in 1854. Officially, the ship carried paying passengers and merchandise such as tanned hides. But the ship also had a darker purpose.
Related: 17 mysterious shipwrecks you can see on Google Earth
In October 1860, La Unión was caught in Campeche, Mexico, carrying 29 Maya, the native people of Central America who were conquered by the Spanish in the 1600s. Following the conquest, the Maya and other Indigenous people were often enslaved on plantations, especially those specializing in sugarcane and coffee. The 29 Maya found in 1860 included children as young as 7.
The loss of La Unión
Slavery was abolished in Mexico in 1829. In May 1861, Mexican president Benito Juárez banned the forcible removal of Indigenous people for sale in other nations. But as the story of La Unión shows, the slave trade continued.
"Each slave was sold to middlemen for 25 pesos, and they resold them in Havana for as much as 160 pesos, for men, and 120 pesos for women," INAH archaeologist Helena Barba Meinecke said in a statement .
This human trafficking occurred against the backgdrop of the Castle War, a clash between Indigenous peoples and the upper classes of Spanish descent, who were levying heavy taxes and seizing farmland from the Indigenous population. Captured Mayan combatants were sold into slavery, often in Cuba, according to INAH. In other cases, slavers called "enganchadores" would travel to Indigenous villages and promise citizens that in Cuba, they would be given their own land. Once the villagers reached Cuba, of course, they were instead enslaved.
Historians estimate that La Unión and another steamer called México, both owned by the same company, smuggled 25 to 30 people to Cuba each month between 1855 and 1861.
On Sept. 19, 1861, La Unión's boilers exploded, setting the steamer aflame. Half of the 80 crew members and 60 paying passengers aboard died. No one knows how many Mayan captives lost their lives, as they were listed as cargo rather than passengers.
The conflagration did draw attention to the illicit human trafficking that was occurring right under the Mexican government's nose, according to INAH. After the loss of La Unión, the government increased searches at Mexican ports to stop the transport of enslaved people.
Originally published on Live Science.


livescience--2020-09-22--Hello fall! Equinox kicks off autumn on Sept. 22

The fall equinox is today ( Sept. 22 ) , but for many it may feel like autumn has already arrived , with crisp weather in the Northeast and Pacific Northwest , picking signs at U-pick farms and at local coffee shops .
If it already feels like autumn in the Northern Hemisphere ( and spring in the Southern Hemisphere ) , what exactly does the fall equinox mark ?
On the fall equinox ( which means `` equal night '' in Latin ) , the amount of daylight is nearly equal to the hours of darkness .
The equinox @ @ @ @ @ @ @ year , it takes place at 9:31 a.m. EDT ( 1:31 p.m. UTC ) on Sept. 22 , according to the National Weather Service ( NWS ) .
At this time , Earth 's axis is tilted neither toward nor away from the sun , leading to an almost equal amount of sunlight and darkness at all latitudes , the NWS reported .
People at the equator will notice that the sun is directly overhead at 12 p.m. local time .
The day and night are n't usually divided up so equally ; @ @ @ @ @ @ @ is typically distributed unequally around the world , .
From mid-March to mid-September , the Northern Hemisphere gets more sun than the Southern Hemisphere , but the rest of the year , the Southern Hemisphere receives more rays .
On the equinox , the `` nearly '' equal day and night happens because , as the sun dips below the horizon , its rays are refracted ( bent ) above the horizon , which makes it seem like daylight is lasting a little longer .
Going forward , nighttime hours will last longer @ @ @ @ @ @ @ as the sun follows a shorter arc across the sky each day , .
On the shortest day of the year , the , ( Dec. 21 ) the sun will travel its shortest arc of the year in the Northern Hemisphere .
Meanwhile , at the , the fall equinox heralds in a time of twilight as the sun sinks below the horizon .
Come October , the North Pole will be shrouded in darkness until a few weeks before the , which happens on March 20 , 2021 .
Then , @ @ @ @ @ @ @ Pole 's horizon once more .

The fall equinox is today (Sept. 22), but for many it may feel like autumn has already arrived, with crisp weather in the Northeast and Pacific Northwest, apple picking signs at U-pick farms and pumpkin spice lattes at local coffee shops.
If it already feels like autumn in the Northern Hemisphere (and spring in the Southern Hemisphere), what exactly does the fall equinox mark?
On the fall equinox (which means "equal night" in Latin), the amount of daylight is nearly equal to the hours of darkness. The equinox happens for just a moment — this year, it takes place at 9:31 a.m. EDT (1:31 p.m. UTC) on Sept. 22, according to the National Weather Service (NWS). At this time, Earth's axis is tilted neither toward nor away from the sun, leading to an almost equal amount of sunlight and darkness at all latitudes, the NWS reported. People at the equator will notice that the sun is directly overhead at 12 p.m. local time.
Related: Autumn equinox: 5 odd facts about fall
The day and night aren't usually divided up so equally; because Earth has a 23.5-degree tilt, daylight is typically distributed unequally around the world, Live Science previously reported . From mid-March to mid-September, the Northern Hemisphere gets more sun than the Southern Hemisphere, but the rest of the year, the Southern Hemisphere receives more rays.
On the equinox, the "nearly" equal day and night happens because, as the sun dips below the horizon, its rays are refracted (bent) above the horizon, which makes it seem like daylight is lasting a little longer.
Going forward, nighttime hours will last longer than daylight in the Northern Hemisphere, as the sun follows a shorter arc across the sky each day, according to NASA . On the shortest day of the year, the winter solstice , (Dec. 21) the sun will travel its shortest arc of the year in the Northern Hemisphere.
Meanwhile, at the North Pole , the fall equinox heralds in a time of twilight as the sun sinks below the horizon. Come October, the North Pole will be shrouded in darkness until a few weeks before the spring equinox , which happens on March 20, 2021. Then, the sun will rise above the North Pole's horizon once more.
Originally published on Live Science.


livescience--2020-09-22--Coronavirus outbreak: Live updates

Coronavirus outbreak: Live updates

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90-year-old woman in the UK receives first dose of Pfizer vaccine, FDA review confirms vaccine is safe and effective A 90-year-old woman (who will turn 91 next week) became the first in the world to be given Pfizer's coronavirus vaccine outside of clinical trials, according to the BBC. Margaret Keenan, who is originally from Northern Ireland, was given the vaccine at the University Hospital in Coventry, England. She received the first of 800,000 doses expected to be administered in the U.K. in the coming weeks, according to the BBC. "I feel so privileged to be the first person vaccinated against Covid-19," Keenan said, according to the BBC."It's the best early birthday present I could wish for because it means I can finally look forward to spending time with my family and friends in the new year after being on my own for most of the year." "My advice to anyone offered the vaccine is to take it. If I can have it at 90, then you can have it too," she added. Up to four million doses of Pfizer's vaccine is expected to be given to people in the U.K. by the end of the month. Meanwhile, a 53-page Food and Drug Administration (FDA) review published Tuesday (Dec. 8) confirmed that Pfizer's vaccine is safe and effective, according to The Washington Post.
Pfizer's COVID-19 vaccine starts to work just 10 days after 1st dose Pfizer's new COVID-19 vaccine starts to protect people from the novel coronavirus just 10 days after the first dose, according to new documents from the U.S. Food and Drug Administration (FDA). The documents were released on Tuesday (Dec. 8), two days before a meeting of the FDA's vaccine advisory panel, which will vote on whether to recommend authorization of the vaccine in the U.S, Live Science reported . The FDA analyzed data from Pfizer's phase 3 clinical trial, which included some 44,000 people in the United States, Brazil, Argentina, Germany and Turkey, about half of whom received the vaccine while the other half received a placebo. Both groups received two shots, 21 days apart. About 10 days after the first dose, there was a noticeable drop-off in new COVID-19 cases in the vaccine group compared with the placebo group, indicating that even one dose provides some protection, the report said. However, scientists don't know how long the protection from a single dose will last, so it will still be important for people to receive two shots, according to The New York Times . Overall, the vaccine was 52% effective after the first dose and 95% effective after the second dose, the report said.
People with significant allergies should avoid Pfizer vaccine, UK warns The U.K.'s Regulatory Agency is advising people with a history of "significant" allergic reactions to avoid Pfizer's coronavirus vaccine, after two National Health Service members developed severe allergic reactions to it on Tuesday (Dec. 8), Live Science reported. "As is common with new vaccines the MHRA (Medicines and Healthcare products Regulatory Agency) have advised on a precautionary basis that people with a significant history of allergic reactions do not receive this vaccination after two people with a history of significant allergic reactions responded adversely yesterday," Stephen Powis, the national medical director for England's National Health Service said in a statement on Wednesday (Dec. 9). Both workers have a history of severe allergies and carry adrenaline auto injectors (such as EpiPens) around with them, according to The Guardian. Shortly after receiving the vaccine, both NHS workers developed anaphylaxis-like symptoms, or severe allergic reactions, but have recovered after receiving treatment. The MHRA will investigate further and Pfizer and BioNTech will support their investigation, according to Reuters. "Allergic reaction occurs with quite a number of vaccines, and perhaps even more frequently with drugs. So it is not unexpected," Stephen Evans, a professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine said in remarks to journalists published by Britain's Science Media Center. “What would be wise, as the MHRA have already advised, would be for anyone who has known severe allergic reaction such that they need to carry an EpiPen, to delay having a vaccination until the reason for the allergic reaction has been clarified," he said. For the general population this does not mean that they would need to be anxious about receiving the vaccination, he added. "One has to remember that even things like marmite [a quintessential British food spread] can cause unexpected severe allergic reactions.”
Canada approves Pfizer's COVID-19 vaccine Canada has authorized Pfizer's new COVID-19 vaccine, with the first doses expected to be administered there as early as next week. Health Canada, the country's health regulatory agency, said in a statement on Wednesday (Dec. 9) that it had determined that the vaccine "meets the Department's stringent safety, efficacy and quality requirements for use in Canada," according to CTV News . "We expect vaccines to arrive maybe as early as Monday [Dec. 14]. It takes time to prepare the vaccine," said Maj.-Gen. Dany Fortin, the top military general leading the vaccine rollout for the Public Health Agency of Canada, according to CTV News. The first doses could be administered by the middle of next week, he said. Canada is the third country in the world to authorize the Pfizer vaccine, following the United Kingdom and Bahrain. The country should receive up to 249,000 doses of the vaccine by the end of December, and has purchased 20 million doses total, with the option to purchase more, CTV News reported.
Daily COVID-19 death toll in the U.S. reaches record-high, surpassed 9/11 On Wednesday (Dec. 9), the U.S. recorded 3,124 new COVID-19 deaths, the highest daily death toll to date, according to CNN . In comparison, 2,977 people were killed in the 9/11 attacks. The U.S. has now recorded 280,488 deaths related to the virus, according to The COVID Tracking Project . A forecast from the U.S. Centers for Disease Control and Prevention predicts that the total death toll can increase to between 332,000 and 362,000 by January 2, according to CNN. There are currently 106,671 people hospitalized with the virus in the U.S.; 20,903 of them are currently in the ICU and 7,621 are currently on a ventilator, according to the COVID Tracking Project. On Thursday (Dec. 10), the Vaccines and Related Biological Products Advisory Committee is set to meet to discuss an emergency use authorization for the Pfizer-BioNTech coronavirus vaccine.
FDA panel recommends authorization of Pfizer's COVID-19 vaccine A panel of experts for the Food and Drug Administration (FDA) has recommended that the agency authorize Pfizer's new COVID-19 vaccine in the United States. On Thursday (Dec. 10), the panel voted 17 to 4 to recommend that the vaccine receive emergency use authorization (EUA) for people ages 16 and older, according to The New York Times . The FDA typically follows the advice of its panels, and so today's vote is an important step towards the vaccine's authorization. It is anticipated that the agency will officially authorize the vaccine on Saturday (Dec. 12), the Times reported. Several countries have already authorized Pfizer's vaccine, including Canada, the United Kingdom and Bahrain.
Vaccine approval could come this weekend, as U.S. continues to record high daily death tolls On Thursday (Dec. 10), the U.S. recorded another 2,902 COVID-19 deaths, a day after the country set a record of 3,253 deaths, according to Reuters . “Probably for the next 60 to 90 days, we’re going to have more deaths per day than we had on 9/11 or we had at Pearl Harbor,” Dr. Robert Redfield, the director of the U.S. Centers for Disease Control and Prevention, told the Council on Foreign Relations on Thursday, according to Reuters. "The reality is the vaccine approval this week is not going to really impact that, I think, to any degree for the next 60 days." On Thursday, the Vaccines and Related Biological Products Advisory Committee discussed, voted and recommended that the Food and Drug Administration (FDA) should grant an emergency use authorization for Pfizer's coronavirus vaccine. The Pfizer vaccine has already been approved in the U.K. and in Canada, and FDA approval for use in the U.S. could come this weekend.
Australia abandons local COVID-19 vaccine after it caused false-positive HIV tests An Australian COVID-19 vaccine that had shown promising results in early trials is being abandoned after researchers found that the shot caused false-positive results on HIV tests. On Friday (Dec. 11), Australian officials said they had canceled an order for some 51 million doses of the vaccine, which was being developed by The University of Queensland and CSL Ltd., a local biotech company, according to The New York Times . In an early trial with 216 participants, the vaccine appeared to be safe and to produce a robust immune response against COVID-19, according to a statement from CSL . But some volunteers falsely tested positive for HIV, which officials feared would undermine trust in the vaccine, the Times reported. The vaccine contained small fragments of an HIV protein, which helped stabilize the vaccine. Some of the participants developed antibodies against these fragments, and these antibodies triggered false positive results on some HIV tests. It's important to note that there is no way for the vaccine to cause an HIV infection, because it contains harmless fragments of the virus.
ICU nurse in New York becomes first person in the US to receive a coronavirus vaccine outside of clinical trials New York, the worst-hit state at the start of the pandemic, just became the first to administer a coronavirus vaccine outside of clinical trials, kicking off a long, massive effort to vaccinate the American people, Live Science reported. Around 9 a.m. E.T. on Monday (Dec. 14), the very first dose of Pfizer and BioNTech's coronavirus vaccine was given to Sandra Lindsay, an intensive care nurse in Long Island Jewish Medical Center in Queens, New York, according to The New York Times. This comes as the U.S. continues to battle a massive wave of the virus that has more than 109,000 people currently hospitalized, according to The COVID Tracking Project. Since the start of the pandemic, New York has recorded more than 780,000 cases of COVID-19 and more than 35,100 deaths, according to The Times. "This vaccine is exciting because I believe this is the weapon that will end the war," Gov. Andrew Cuomo said during a live broadcast of the first vaccination. "It's the beginning of the last chapter of the book, but now we just have to do it."
FDA analysis confirms Moderna's vaccine is safe and effective, emergency authorization is likely to come Friday A new briefing document from the Food and Drug Administration (FDA) released on Tuesday (Dec. 15) confirmed that Moderna's COVID-19 vaccine is safe and effective, according to NPR . Moderna's COVID-19 vaccine is 94% effective and has "a favorable safety profile," according to the document. A panel of experts is set to meet on Thursday (Dec. 17) to discuss the effectiveness and safety of the vaccine and vote on whether or not the FDA should grant emergency approval to the vaccine. Last week, the same panel voted that the FDA should grant emergency approval to Pfizer's coronavirus vaccine; the authorization came a day late and the first doses were given on Monday (Dec. 15). The FDA will likely approve Moderna's vaccine for emergency use on Friday (Dec. 18), according to The New York Times .
FDA authorizes first over-the-counter COVID-19 test The U.S. Food and Drug Administration (FDA) has authorized the first over-the-counter COVID-19 test, which can be done at home and does not need a prescription. The test, made by the Australia-based company Ellume, provides results in as little as 20 minutes, according to a statement from the FDA . It is a "lateral flow antigen test," meaning it works in a similar way to a home pregnancy test, by running a "liquid sample along a surface with reactive molecules," the FDA said. The test works in conjunction with a smartphone app. Users take a nasal swab and place their sample in an analyzer, which communicates to the smartphone app via Bluetooth. The results are delivered through the app, and also reported to public health authorities (based on a user's zip code) through a secure cloud connection, the company said . Ellume is ramping up production of its test, and expects to produce three million tests in January 2021, and 20 million within the first half of 2021.
A wild mink tested positive for the coronavirus, it may be the first wild animal to have a confirmed case A wild mink in Utah may be the first "free-ranging, native wild animal" confirmed to be infected with SARS-CoV-2, according to the U.S. Department of Agriculture (USDA), Live Science reported. The mink was found near a mink farm and likely picked up the infection from the farmed mink. There's no evidence that the virus spread to other minks or wild animals; but if the virus does begin circulating in wild animals, it could pick up mutations that COVID-19 vaccines may not protect well against if it spreads back to humans, according to the report. "If it does [establish a reservoir], then we've got a long-term issue here, where this virus has the potential to be with us for millennia," Sarah Olson, associate director of the health program at the Wildlife Conservation Society, told Vox. The U.S. Department of Agriculture's Animal and Plant Health Inspection Service has screened other animal species for the virus near mink farms in Utah, Michigan and Wisconsin, but all of them have tested negative so far, according to a statement.
An FDA advisory panel will meet today to vote on whether to recommend Moderna's coronavirus vaccine for emergency approval On Thursday (Dec. 17), a Food and Drug Administration (FDA) advisory committee will meet to determine whether to recommend that Moderna’s coronavirus vaccine for emergency approval, according to The New York Times . This panel, composed of independent experts, will vote on whether to recommend the vaccine after hearing from the company, FDA scientists and the public, according to The Times. Last week, the same panel of experts met to discuss Pfizer’s coronavirus vaccine and voted to recommend emergency authorization; the authorization came the next day. There have now been more than 16.9 million cases of COVID-19 in the U.S. and more than 307,000 deaths, according to the Johns Hopkins dashboard . There are currently 113,090 people hospitalized across the country with more than 21,900 of them in the ICU and 7,778 on a ventilator, according to The COVID Tracking Project .
California becomes new epicenter of COVID-19 in U.S. California, once praised for its early pandemic response, is now the new U.S. hotspot for COVID-19 infections. The state has reported an alarming surge in cases, breaking previous records for daily cases. On Thursday (Dec. 17), the state reported some 50,000 COVID-19 infections in 24 hours, and nearly 100,000 in 48 hours, according to The Washington Post . That's more than the daily cases reported in many countries, including India, Germany and Britain, the Post reported. The state also set a record for daily deaths on Thursday, with 379 fatalities reported, up from the previous high of 293. Capacity in intensive care units has also dropped dramatically, with hospitals in Southern California reporting zero percent capacity on Thursday. "I want to be very clear: Our hospitals are under siege, and our model shows no end in sight," said Christina Ghaly, director of Los Angeles County's Department of Health Services, the Post reported.
FDA expected to authorize Moderna's vaccine on Friday The U.S. Food and Drug Administration is expected to authorize Moderna's COVID-19 vaccine on Friday (Dec. 18). Once authorized, it will be the second coronavirus vaccine to get the green light from the agency in just a week, with Pfizer's vaccine gaining authorization on Dec. 11. Moderna is expected to begin shipping 5.9 million doses of its vaccine on Sunday (Dec. 20), with the first deliveries arriving Monday (Dec. 21), according to The New York Times . Unlike the Pfizer vaccine, Moderna's vaccine does not require storage in extremely cold temperatures, and states are hoping to distribute the vaccine to rural hospitals and community health centers, the Times reported.
COVID-19 cases continue to surge across the U.S. There have now been more than 17 million cases of COVID-19 in the U.S. and more than 300,000 deaths, according to The COVID Tracking Project . There are currently 114,237 people hospitalized across the country and 21,900 people in the ICU. California is facing a massive surge in cases; the state reported 41,012 new COVID-19 cases and 300 new deaths on Thursday (Dec. 17), according to the state's COVID-19 dashboard . By comparison, at the start of November, California was reporting a seven-day average of 4,183 cases, compared to an average of 38,774 on Thursday, according to CNN . "We're experiencing an explosive and very deadly surge," Dr. Barbara Ferrer, Los Angeles County Public Health Director said, according to CNN. Intensive care unit beds are rapidly filling up across the state; there are only 1,234 ICU beds left available in California, according to the dashboard. Current closures across California are impacting around 98% of the state's population, according to CNN.
London and southeast England are under an emergency lockdown Following concerns of a new version of the coronavirus that might be more transmissible, London and most of southeast England are now under an emergency lockdown, according to The New York Times . Prime Minister Boris Johnson announced the lockdown on Saturday (Dec. 19) citing concerns that the mutated virus — which was detected a couple of weeks ago in southeast England — may be as much as 70% more transmissible than previous versions, according to the Times. The new version of the coronavirus is detected in more than 60% of new infections in London and have also been detected in several other countries, according to the Times. But it's not yet clear if this coronavirus version is any more infectious than the last and thorough analyses will need to be conducted before conclusions are made, scientists cautioned. In South Africa, a similar version of the virus has been found in up to 90% of new cases detected since mid-November, according to The Times . It's common for viruses to mutate, and this particular coronavirus has mutated many times since the start of the pandemic. But experts told The Times that it would take years for the virus to mutate enough such that it would make the current vaccines developed to fight COVID-19 ineffective.
Biden gets Pfizer's COVID-19 vaccine President-elect Joe Biden received a dose of Pfizer's new COVID-19 vaccine on Monday (Dec. 21), according to The New York Times . He received the shot on camera at the Christiana Hospital in Newark, Delaware. "I'm doing this to demonstrate that people should be prepared when it's available to take the vaccine. There's nothing to worry about," Biden said.
Antarctica has its 1st COVID-19 outbreak The first COVID-19 cases have been reported in Antarctica , meaning the disease has now spread to every continent in the world. On Tuesday (Dec. 22), Chilean officials reported an outbreak of 36 COVID-19 cases at the Chilean research base General Bernardo O'Higgins Riquelme on the Antarctic Peninsula, according to the BBC . Of these, 26 cases were military personnel and 10 were maintenance workers, the BBC reported. All of these cases have been evacuated from Antarctica to Punta Arenas, Chile, according to The Guardian . Antarctica had been COVID-19 free up until the current outbreak. The continent has no permanent residents, but about 1,000 people, including scientists and other workers, stayed there this past winter, The Guardian reported.
Live updates will continue in 2021!


livescience--2020-09-22--'Grand claims' of life on Venus lack evidence, skeptics say

Last week , a team of researchers told the world that they had in the upper cloud layers of Venus typically only created by living creatures here on .
The blockbuster announcement of finding phosphine in the clouds of Venus made a major splash in the news .
But pushback began appearing even as details of the results were coming to light .
In the days since , scientists have had some time to articulate their criticisms , which fall into two main camps .
On one side , there are those who question the detection itself and whether the @ @ @ @ @ @ @ to have seen .
And a second attack heavily scrutinizes the interpretation and whether or not life is a good conclusion to arrive at .
Related : 10 interesting places in the solar system we 'd like to visit Even those who are skeptical believe the findings to be intriguing .
Venus has a hot and hellish surface , but the idea that life might exist in its relatively balmy upper atmosphere has been around for a long time .
Everyone understands that this is not the final word on the matter , @ @ @ @ @ @ @ fully sort out .
`` Obviously if it 's correct , it 's an extremely cool result and potentially has profound implications , '' John Carpenter , an observatory scientist at the Atacama Large Millimetre/submillimetre Array ( ALMA ) in Chile , told Live Science .
`` But grand claims demand grand evidence . ''
At the center of this debate is the molecule phosphine , or PH3 , which is made from one atom bonded to three atoms .
Phosphine is a nasty and poisonous gas for many creatures , including humans @ @ @ @ @ @ @ in rotting sewage and swamps where oxygen is lacking , as well as in the intestines of some animals .
Using the James Clerk Maxwell Telescope in Hawaii and ALMA , astronomers looked for telltale dips in Venus ' light that would indicate the presence of different chemicals , and noticed one associated with phosphine .
The result is particularly perplexing because Venus ' atmosphere is full of carbon dioxide and other oxygen-containing molecules , which should rip apart phosphine in no time .
To have it present in any amount is bewildering @ @ @ @ @ @ @ see phosphine ?
The observations contain a good amount of noise , which might simply be mimicking a phosphine signal , suggested Carpenter .
Michael Way , a physical scientist at NASA 's Goddard Institute for Space Studies in New York City , agreed .
`` More lines are needed to verify that it is this particular molecule , '' Way told Live Science in an email .
`` As this point it 's not 100 % clear exactly what they have measured . ''
In particular , Way pointed out that there @ @ @ @ @ @ @ , SO2 , at nearly the same frequency of light .
Sulfur dioxide is the third most abundant gas in Venus ' atmosphere , so its presence might account for the phosphine finding , David Catling , an astrobiologist at the University of Washington in Seattle , told Live Science in an email .
The team who made the original phosphine finding is interested in doing follow-up observations to verify their results .
And independent investigators with NASA 's Stratospheric Observatory for Infrared Astronomy ( SOFIA ) telescope , the Very Large Telescope @ @ @ @ @ @ @ Agency 's BepiColombo spacecraft , which will soon fly past Venus on its way to Mercury , are all planning their own phosphine searches .
But even if phosphine exists on our sister world , there are many reasons to doubt that life is making it .
Here on Earth , phosphine is associated with living organisms , but Venus is quite literally an alien planet , and scientists do n't yet fully understand its many complex details .
Phosphine is a very simple molecule , just four atoms large , and `` @ @ @ @ @ @ @ , '' Lee Cronin , a chemist at the University of Glasgow in the United Kingdom , who has been about the results , told Live Science .
`` You just combine phosphorus and a base .
I 've made it by mistake . ''
The team who made the detection tried to think of all the possible non-living routes they could imagine for producing phosphine on Venus , releasing a Sept. 14 describing their attempts , and coming up short in every case .
( That paper has not yet been peer-reviewed @ @ @ @ @ @ @ there was n't something they missed .
Cronin suggested that Venus ' surface , which is thought to be geologically active , might on occasion split open , revealing underground reserves of phosphorus .
Should Venus ' sulfuric acid ( H2SO4 ) clouds then send down rain , they might spark a reaction to form plumes of phosphine that could explain its presence in the atmosphere .
Any number of other ways to make phosphine could also be plausible , he added .
`` You set up a false narrative , '' Cronin @ @ @ @ @ @ @ Venus , and phosphine has been seen in Earth biology ; therefore there 's life on Venus . ''
Moreover , the idea of Earth-like organisms , even microbial ones , living in Venus ' hellish , toxic atmosphere is a tough one for many scientists .
`` The cloud droplets are concentrated sulfuric acid , '' Catling said .
`` Chemists know that if you add biomolecules to concentrated sulfuric acid , you 'll get a vigorous reaction where the biomolecules end up looking like charcoal and deader than a doornail .
@ @ @ @ @ @ @ these clouds , it is at concentrations six times drier than , which terrestrial microbes are unable to live in , Catling added .
This is the reason honey does not need to be kept in the fridge , and why it can last for thousands of years without perishing .
`` Life in Venus ' life-killing clouds is just a hard sell , '' Catling said .
Figuring out just what is going on in this case is likely to take a while .
`` Expect a lot of interesting papers , @ @ @ @ @ @ @ the coming months , '' Way said .
The one thing that 's certain is that Venus will be receiving a great deal more attention in the near future .
For his part , Cronin believes it 's possible life does exist in Venus ' clouds , but that it is liable to have chemistry quite unlike terrestrial organisms .
A molecule like phosphine could be a `` bio-hint , '' he said , but would need additional information to definitively prove whether or not it ’ s being created by life .
@ @ @ @ @ @ @ doing is super interesting , '' he added .
`` I just think they should have moderated it even more judiciously . ''
Editor 's Note : This story was updated to clarify that phosphine can be made easily in the lab by combining phosphorus with a base , not phosphorus and hydrogen .

Last week, a team of researchers told the world that they had detected a molecule in the upper cloud layers of Venus typically only created by living creatures here on Earth .
The blockbuster announcement of finding phosphine in the clouds of Venus made a major splash in the news. But pushback began appearing even as details of the results were coming to light.
In the days since, scientists have had some time to articulate their criticisms, which fall into two main camps. On one side, there are those who question the detection itself and whether the team has definitely seen what they claim to have seen. And a second attack heavily scrutinizes the interpretation and whether or not life is a good conclusion to arrive at.
Related: 10 interesting places in the solar system we'd like to visit
Even those who are skeptical believe the findings to be intriguing. Venus has a hot and hellish surface, but the idea that life might exist in its relatively balmy upper atmosphere has been around for a long time. Everyone understands that this is not the final word on the matter, which is likely to take years to fully sort out.
"Obviously if it's correct, it's an extremely cool result and potentially has profound implications," John Carpenter, an observatory scientist at the Atacama Large Millimetre/submillimetre Array (ALMA) in Chile, told Live Science. "But grand claims demand grand evidence."
At the center of this debate is the molecule phosphine, or PH3, which is made from one phosphorus atom bonded to three hydrogen atoms. Phosphine is a nasty and poisonous gas for many creatures, including humans, but is produced by bacteria living in rotting sewage and swamps where oxygen is lacking, as well as in the intestines of some animals.
Using the James Clerk Maxwell Telescope in Hawaii and ALMA, astronomers looked for telltale dips in Venus' light that would indicate the presence of different chemicals, and noticed one associated with phosphine. The result is particularly perplexing because Venus' atmosphere is full of carbon dioxide and other oxygen-containing molecules, which should rip apart phosphine in no time. To have it present in any amount is bewildering.
But did the research team really see phosphine? The observations contain a good amount of noise, which might simply be mimicking a phosphine signal, suggested Carpenter.
Michael Way, a physical scientist at NASA's Goddard Institute for Space Studies in New York City, agreed.
"More lines are needed to verify that it is this particular molecule," Way told Live Science in an email. "As this point it's not 100% clear exactly what they have measured."
In particular, Way pointed out that there is a signature associated with sulfur dioxide, SO2, at nearly the same frequency of light. Sulfur dioxide is the third most abundant gas in Venus' atmosphere, so its presence might account for the phosphine finding, David Catling, an astrobiologist at the University of Washington in Seattle, told Live Science in an email.
The team who made the original phosphine finding is interested in doing follow-up observations to verify their results. And independent investigators with NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) telescope, the Very Large Telescope in Chile, and the European Space Agency's BepiColombo spacecraft, which will soon fly past Venus on its way to Mercury, are all planning their own phosphine searches.
But even if phosphine exists on our sister world, there are many reasons to doubt that life is making it. Here on Earth, phosphine is associated with living organisms, but Venus is quite literally an alien planet, and scientists don't yet fully understand its many complex details.
Phosphine is a very simple molecule, just four atoms large, and "super easy to make in the laboratory," Lee Cronin, a chemist at the University of Glasgow in the United Kingdom, who has been vocal on Twitter about the results, told Live Science. "You just combine phosphorus and a base. I've made it by mistake."
The team who made the detection tried to think of all the possible non-living routes they could imagine for producing phosphine on Venus, releasing a 100-page paper on arxiv Sept. 14 describing their attempts, and coming up short in every case. (That paper has not yet been peer-reviewed.) But that doesn't mean there wasn't something they missed.
Cronin suggested that Venus' surface, which is thought to be geologically active, might on occasion split open, revealing underground reserves of phosphorus. Should Venus' sulfuric acid (H2SO4) clouds then send down rain, they might spark a reaction to form plumes of phosphine that could explain its presence in the atmosphere. Any number of other ways to make phosphine could also be plausible, he added.
"You set up a false narrative," Cronin said. "Phosphine is present on Venus, and phosphine has been seen in Earth biology; therefore there's life on Venus."
Moreover, the idea of Earth-like organisms, even microbial ones, living in Venus' hellish, toxic atmosphere is a tough one for many scientists. "The cloud droplets are concentrated sulfuric acid," Catling said. "Chemists know that if you add biomolecules to concentrated sulfuric acid, you'll get a vigorous reaction where the biomolecules end up looking like charcoal and deader than a doornail."
While some water is present in these clouds, it is six times less available than it is in honey , which terrestrial microbes are unable to live in, Catling added. This is the reason honey does not need to be kept in the fridge, and why it can last for thousands of years without perishing. "Life in Venus' life-killing clouds is just a hard sell," Catling said.
Figuring out just what is going on in this case is likely to take a while. "Expect a lot of interesting papers, many wrong and many correct, in the coming months," Way said.
The one thing that's certain is that Venus will be receiving a great deal more attention in the near future. For his part, Cronin believes it's possible life does exist in Venus' clouds, but that it is liable to have chemistry quite unlike terrestrial organisms. A molecule like phosphine could be a "bio-hint," he said, but would need additional information to definitively prove whether or not it’s being created by life.
"I think what these guys are doing is super interesting," he added. "I just think they should have moderated it even more judiciously."
Editor's Note: This story was updated to clarify that phosphine can be made easily in the lab by combining phosphorus with a base, not phosphorus and hydrogen. It was also corrected to note that water is six times less available the clouds of Venus, but those clouds are not six times drier.
Originally published on Live Science.


livescience--2020-09-22--What is dark matter?

What is dark matter?

Dark matter is a mysterious non-luminous substance making up the vast majority of matter in the universe .
Though experts have observed the gravitational effects of dark matter for decades , scientists remain baffled as to its true nature .
In the late 19th century , astronomers began speculating about unseen material — either dim stars or gas and dust , scattered throughout the universe .
Researchers had even begun to estimate its mass , according to a 2018 review in the journal Reviews of Modern Physics .
Most thought this mysterious substance was a minor component of the total @ @ @ @ @ @ @ n't until 1933 that Swiss-American astronomer Fritz Zwicky noticed that distant galaxies were spinning around one another much faster than should be possible given their visible matter seen in telescopes .
`` If this would be confirmed , we would get the surprising result that dark matter is present in much greater amount than luminous matter , '' he wrote in a paper published in the journal Helvetica Physica Acta that year .
But many in the field remained skeptical of Zwicky 's results until the 1970s , when astronomers Kent Ford and @ @ @ @ @ @ @ in the outer regions of the neighboring Andromeda galaxy .
These stars were orbiting the galactic core far too quickly , almost as if some invisible material was gravitationally tugging on them and pushing them along — an observation scientists soon noticed in galaxies all over the universe .
Researchers had no idea what this unseen mass consisted of , with some astronomers speculating that dark matter was made up of small black holes or other compact objects that gave off too little light to show up in telescopes .
The results got @ @ @ @ @ @ @ a space telescope called the Wilkinson Microwave Anisotropy Probe ( WMAP ) showed that this dark matter outweighed ordinary visible matter by five to one , according to NASA .
Telescope surveys were never able to find enough small compact objects to account for this enormous profusion of material .
Most modern-day astronomers think dark matter likely consists of subatomic particles with properties that are rather different from more familiar protons and neutrons .
The reigning candidate for dark matter is called a Weakly Interacting Massive Particle or WIMP .
These speculative entities @ @ @ @ @ @ @ of particle physics , which describes almost all particles and forces .
WIMPs would be more similar to the ghostly neutrino , except it would weigh 10 to 100 times more than a proton .
( Neutrinos ' exact masses are unknown but they are far lighter than electrons ) .
Like neutrinos , WIMPs would only interact with two of the four fundamental forces in the universe : Gravity and the nuclear weak force , which mediates the decay of radioactive atomic nuclei .
These dark matter particles would be electrically neutral @ @ @ @ @ @ @ with electromagnetism , the basis of light , and would therefore remain invisible .
Physicists have built enormous detectors and placed them deep underground to protect them from interfering cosmic rays in efforts to detect WIMPs , but so far no experiment has uncovered evidence for them .
In recent years , this failure has led some in the field to begin wondering if they 've headed on a wild particle chase with no real end .
Some scientists are therefore turning their attention to a newer dark matter candidate called the axion @ @ @ @ @ @ @ even a billionth the mass of an electron , the Proceedings of the National Academy of Science reported .
These hypothetical particles are particularly attractive to researchers because they could also solve another outstanding problem in physics , potentially interacting with neutrons to explain why they can feel magnetic fields but not electric ones .
In June 2020 , members of the XENON1T experiment based at the Gran Sasso National Laboratory in Italy , a detector originally built to try capturing WIMPs , announced that they had found a small but unexpected signal @ @ @ @ @ @ @ of axions .
The results shocked the scientific community , but have yet to be confirmed by other experiments .
This means that researchers are still scratching their heads over just what dark matter is .
Some theorists have wondered if there is an entire dark sector of the universe , with multiple particles and even dark forces that only affect dark matter , akin to the subatomic complexity seen in the visible cosmos .
At the same time , a minority of scientists believe that dark matter is a mirage .
They @ @ @ @ @ @ @ version of inertia , or MOND , which conjectures that on large scales , gravity acts differently than expected and this accounts for the observed rotations of stars and galaxies .
But most experts are n't convinced of the need to take such a radical departure from known physics , which would also require modifications to our understanding of large parts of reality .
Dark matter is not , to anyone 's knowledge , linked with dark energy , another mysterious phenomenon responsible for accelerating the expansion of the cosmos .
The two @ @ @ @ @ @ @ '' which is often used as a placeholder by scientists for things they do n't entirely understand .
• Read more about dark matter from .
• Learn more about the difference between dark matter and dark energy , from .
• Watch this recording of a given by Fermilab physicist Dan Bauer , explaining what dark matter is , and why it matters .

Scientists aren't really sure what dark matter is, and some experts question if it even exists.
Dark matter is a mysterious non-luminous substance making up the vast majority of matter in the universe. Though experts have observed the gravitational effects of dark matter for decades, scientists remain baffled as to its true nature.
Who discovered dark matter?
In the late 19th century, astronomers began speculating about unseen material — either dim stars or gas and dust, scattered throughout the universe. Researchers had even begun to estimate its mass, according to a 2018 review in the journal Reviews of Modern Physics. Most thought this mysterious substance was a minor component of the total mass in the cosmos.
It wasn't until 1933 that Swiss-American astronomer Fritz Zwicky noticed that distant galaxies were spinning around one another much faster than should be possible given their visible matter seen in telescopes. "If this would be confirmed, we would get the surprising result that dark matter is present in much greater amount than luminous matter," he wrote in a paper published in the journal Helvetica Physica Acta that year.
But many in the field remained skeptical of Zwicky's results until the 1970s, when astronomers Kent Ford and Vera Rubin made detailed studies of stars in the outer regions of the neighboring Andromeda galaxy. These stars were orbiting the galactic core far too quickly, almost as if some invisible material was gravitationally tugging on them and pushing them along — an observation scientists soon noticed in galaxies all over the universe.
Researchers had no idea what this unseen mass consisted of, with some astronomers speculating that dark matter was made up of small black holes or other compact objects that gave off too little light to show up in telescopes. The results got even stranger in the 1990s, when a space telescope called the Wilkinson Microwave Anisotropy Probe (WMAP) showed that this dark matter outweighed ordinary visible matter by five to one, according to NASA.
Why dark matter remains a mystery
Telescope surveys were never able to find enough small compact objects to account for this enormous profusion of material. Most modern-day astronomers think dark matter likely consists of subatomic particles with properties that are rather different from more familiar protons and neutrons.
The reigning candidate for dark matter is called a Weakly Interacting Massive Particle or WIMP. These speculative entities are not found in the Standard Model of particle physics, which describes almost all particles and forces. WIMPs would be more similar to the ghostly neutrino, except it would weigh 10 to 100 times more than a proton. (Neutrinos' exact masses are unknown but they are far lighter than electrons).
Like neutrinos, WIMPs would only interact with two of the four fundamental forces in the universe: Gravity and the nuclear weak force, which mediates the decay of radioactive atomic nuclei. These dark matter particles would be electrically neutral, which means they would not interact with electromagnetism, the basis of light, and would therefore remain invisible.
Physicists have built enormous detectors and placed them deep underground to protect them from interfering cosmic rays in efforts to detect WIMPs, but so far no experiment has uncovered evidence for them. In recent years, this failure has led some in the field to begin wondering if they've headed on a wild particle chase with no real end.
Some scientists are therefore turning their attention to a newer dark matter candidate called the axion, which would be a millionth or even a billionth the mass of an electron, the Proceedings of the National Academy of Science reported. These hypothetical particles are particularly attractive to researchers because they could also solve another outstanding problem in physics, potentially interacting with neutrons to explain why they can feel magnetic fields but not electric ones.
In June 2020, members of the XENON1T experiment based at the Gran Sasso National Laboratory in Italy, a detector originally built to try capturing WIMPs, announced that they had found a small but unexpected signal that could be explained by the presence of axions. The results shocked the scientific community, but have yet to be confirmed by other experiments.
Is dark matter even real?
This means that researchers are still scratching their heads over just what dark matter is. Some theorists have wondered if there is an entire dark sector of the universe, with multiple particles and even dark forces that only affect dark matter, akin to the subatomic complexity seen in the visible cosmos.
At the same time, a minority of scientists believe that dark matter is a mirage. They subscribe to an idea known as modified version of inertia, or MOND, which conjectures that on large scales, gravity acts differently than expected and this accounts for the observed rotations of stars and galaxies. But most experts aren't convinced of the need to take such a radical departure from known physics, which would also require modifications to our understanding of large parts of reality.
Dark matter is not, to anyone's knowledge, linked with dark energy, another mysterious phenomenon responsible for accelerating the expansion of the cosmos. The two simply share the word "dark," which is often used as a placeholder by scientists for things they don't entirely understand.
Additional resources:


livescience--2020-09-22--Tropical storm Beta floods Houston, and days of heavy rainfall are still to come

Floods and heavy rain have closed schools and businesses across southeastern Texas , as tropical storm Beta moves across the region .
Beta is weaker than initial projections , but it is still dumping a dangerous amount of water on the region .
Its slow progress makes the situation worse , because there 's more time for rain to fall on impacted areas .
Related : 10 signs that Earth 's climate is off the rails '' This is a very slow-moving storm that has tracked inland .
Please be weather aware and stay off the roadways unless travel is @ @ @ @ @ @ @ Acevedo wrote on Twitter .
Flash floods will be likely across southeastern Texas for days , according to the National Hurricane Center ( NHC ) .
In Galveston , a city on a barrier island off the Texas coast , Beta brought high tides 3 feet ( 91 centimeters ) higher than usual .
That caused serious damage to coastal dunes that protect the island from flooding , according to The Daily News — compounding damage the dunes took from Hurricane Laura less than a month ago .
Once Beta is done with @ @ @ @ @ @ @ move out over water again , before making a second landfall in Louisiana , according to the NHC .
Many in that region , particularly Lake Charles , are still homeless or without power after Laura , according to local TV station 7-KPLC .
Some may never rebuild at this point , the news station reported .
Beta is the first storm named after a Greek letter ever to hit the mainland United States .
( Alpha hit Portugal last week , and the six Greek-letter storms that formed in 2005 hit Atlantic @ @ @ @ @ @ @ . )
The NHC uses Greek letters when it runs out of names from its alphabetical-order list prepared before hurricane season .
This has only happened once before , in 2005 .
The first half of hurricane season this year has been by far the busiest ever , exhausting the list much faster than 2005 , when Greek letters were n't called on until late October .
There have been 23 named storms so far this year , and there are 22 letters left in the Greek alphabet .
Scientists believe that as @ @ @ @ @ @ @ will become more powerful .
This year 's extraordinary hurricane season on the East Coast has coincided with a brutal series of heat waves and associated wildfires on the West Coast , which has been blanketed in smoke .
( Wildfire season is also getting worse thanks to climate change . )
Most Atlantic hurricanes and tropical storms happen during September and October , though they often extend into November .
In the 2005 season , the final storm did n't peter out over water until after the start of the new year @

Floods and heavy rain have closed schools and businesses across southeastern Texas, as tropical storm Beta moves across the region.
Beta is weaker than initial projections, but it is still dumping a dangerous amount of water on the region. Its slow progress makes the situation worse, because there's more time for rain to fall on impacted areas.
Related: 10 signs that Earth's climate is off the rails
"This is a very slow-moving storm that has tracked inland. Please be weather aware and stay off the roadways unless travel is necessary," Houston police chief Art Acevedo wrote on Twitter.
Flash floods will be likely across southeastern Texas for days, according to the National Hurricane Center (NHC).
New pictures from our photog @vphotopro of 288. It’s easy to see why it’s closed in both directions near Holly Hall. This is one of more than 50 high water spots around Houston. #TropicalStormBeta #houwx pic.twitter.com/nNvGfif8YjSeptember 22, 2020 See more
In Galveston, a city on a barrier island off the Texas coast, Beta brought high tides 3 feet (91 centimeters) higher than usual. That caused serious damage to coastal dunes that protect the island from flooding, according to The Daily News — compounding damage the dunes took from Hurricane Laura less than a month ago.
Once Beta is done with Texas, the storm is expected to move out over water again, before making a second landfall in Louisiana, according to the NHC. Many in that region, particularly Lake Charles, are still homeless or without power after Laura, according to local TV station 7-KPLC. Some may never rebuild at this point, the news station reported.
Beta is the first storm named after a Greek letter ever to hit the mainland United States. (Alpha hit Portugal last week, and the six Greek-letter storms that formed in 2005 hit Atlantic islands or petered out over open water.) The NHC uses Greek letters when it runs out of names from its alphabetical-order list prepared before hurricane season. This has only happened once before, in 2005.
Related: A history of destruction: 8 great hurricanes
The first half of hurricane season this year has been by far the busiest ever, exhausting the list much faster than 2005, when Greek letters weren't called on until late October. There have been 23 named storms so far this year, and there are 22 letters left in the Greek alphabet.
Scientists believe that as climate change warms the oceans, hurricanes will become more powerful. This year's extraordinary hurricane season on the East Coast has coincided with a brutal series of heat waves and associated wildfires on the West Coast, which has been blanketed in smoke. (Wildfire season is also getting worse thanks to climate change.) Most Atlantic hurricanes and tropical storms happen during September and October, though they often extend into November. In the 2005 season, the final storm didn't peter out over water until after the start of the new year.
Originally published on Live Science.


livescience--2020-09-22--Lightning killed 2 giraffes in South Africa: Were they doomed by their height?

Lightning recently killed two in South Africa ; one of the giraffes — a 5-year-old female — had a fractured skull and a broken ossicone ( giraffes ' knoblike horns ) , indicating that she died after a lightning strike directly to the head .
The giraffes were found on March 2 after a thunderstorm in Rockwood , a private nature reserve located about 112 miles ( 180 kilometers ) to the west of Kimberley , South Africa .
Ciska P. J. Scheijen , a student in the Department of Animal , Wildlife and Grassland Sciences at the University of @ @ @ @ @ @ @ Africa , described the fatal event on Sept. 8 in the , suggesting that the animals ' height may have increased their risk for electrocution during the storm , turning them into living lightning rods .
However , no peer-reviewed studies have shown that giraffes are more prone to lightning strikes than other animals , , and Scheijen did not present any new data on the subject .
There are four ways that lightning strikes can kill an animal , according to Schiejen 's paper .
It can strike the animal directly or @ @ @ @ @ @ @ flash , '' arcing into the animal 's body after striking a nearby object .
It can also be lethal through `` touch potential , '' when the jolts through an animal that is in direct contact with a lightning-struck object .
Finally , lightning can also deliver a deadly current through `` step potential , '' which electrifies the animal through the ground .
The giraffes in South Africa died surrounded by bushes and grasses , but there were no trees nearby ; an adult male giraffe stands about 18 feet ( @ @ @ @ @ @ @ measure about 14 feet ( 4.3 m ) tall ; so the giraffes would easily have been the tallest targets in the area .
The body of the second giraffe , a female about 4 years old , was found about 23 feet ( 7 m ) from the giraffe with the cracked skull .
There were no visible signs of injury on the younger giraffe , hinting that it received a lethal dose of electricity through the ground as its companion was directly struck , Scheijen reported .
`` Both giraffes had @ @ @ @ @ @ @ Scheijen added .
Researchers had previously mentioned a similar odor surrounding a lightning-struck giraffe , in a study published in 2014 in the journal .
Thousands of animals are injured each year by lightning , according to a study published in 2012 in the .
And some animals are more vulnerable than others .
Those with `` a large separation between their front and back feet '' are more likely to suffer significant lightning damage because their feet can act as points in a circuit that channel voltage , after lightning strikes the @ @ @ @ @ @ @ to the study .
Ground current electrocution is the most common cause of group death for animals during electrical storms .
In one exceptional event in 2016 , — including seven calves — through ground current , as the reindeer huddled close together during the storm .
In the case of the South African giraffes , Scheijen concluded that a direct lightning strike killed the older female , `` while the other female , found some 7 m [ 23 feet ] away , died likely either from a side flash or step @ @ @ @ @ @ @ Given that lightning bolts tend to hit tall objects , especially in open areas , the height of giraffes may make them particularly vulnerable to fatal electrocution , '' Scheijen said .

Lightning recently killed two giraffes in South Africa; one of the giraffes — a 5-year-old female — had a fractured skull and a broken ossicone (giraffes' knoblike horns), indicating that she died after a lightning strike directly to the head.
The giraffes were found on March 2 after a thunderstorm in Rockwood, a private nature reserve located about 112 miles (180 kilometers) to the west of Kimberley, South Africa.
Ciska P. J. Scheijen, a student in the Department of Animal, Wildlife and Grassland Sciences at the University of the Free State in Bloemfontein, South Africa, described the fatal event on Sept. 8 in the African Journal of Ecology , suggesting that the animals' height may have increased their risk for electrocution during the storm, turning them into living lightning rods.
Related: Rare white giraffe photographed
However, no peer-reviewed studies have shown that giraffes are more prone to lightning strikes than other animals, Live Science reported in 2017 , and Scheijen did not present any new data on the subject.
There are four ways that lightning strikes can kill an animal, according to Schiejen's paper. It can strike the animal directly or it can hit as a "side flash," arcing into the animal's body after striking a nearby object. It can also be lethal through "touch potential," when the electrical current jolts through an animal that is in direct contact with a lightning-struck object. Finally, lightning can also deliver a deadly current through "step potential," which electrifies the animal through the ground.
The giraffes in South Africa died surrounded by bushes and grasses, but there were no trees nearby; an adult male giraffe stands about 18 feet (5.5 meters) tall, while females measure about 14 feet (4.3 m) tall; so the giraffes would easily have been the tallest targets in the area. The body of the second giraffe, a female about 4 years old, was found about 23 feet (7 m) from the giraffe with the cracked skull. There were no visible signs of injury on the younger giraffe, hinting that it received a lethal dose of electricity through the ground as its companion was directly struck, Scheijen reported.
"Both giraffes had a very strong ammonia-like smell," Scheijen added. Researchers had previously mentioned a similar odor surrounding a lightning-struck giraffe, in a study published in 2014 in the journal Vulture News .
Death from above
Thousands of animals are injured each year by lightning, according to a study published in 2012 in the International Journal of Biometeorology . And some animals are more vulnerable than others. Those with "a large separation between their front and back feet" are more likely to suffer significant lightning damage because their feet can act as points in a circuit that channel voltage, after lightning strikes the ground or a nearby object, according to the study.
Ground current electrocution is the most common cause of group death for animals during electrical storms. In one exceptional event in 2016, lightning killed 323 reindeer — including seven calves — through ground current, as the reindeer huddled close together during the storm.
In the case of the South African giraffes, Scheijen concluded that a direct lightning strike killed the older female, "while the other female, found some 7 m [23 feet] away, died likely either from a side flash or step potential," Scheijen reported.
"Given that lightning bolts tend to hit tall objects, especially in open areas, the height of giraffes may make them particularly vulnerable to fatal electrocution," Scheijen said.
Originally published on Live Science.


livescience--2020-09-22--US reaches staggering milestone — 200,000 COVID-19 deaths

The coronavirus pandemic has reached another bleak milestone in the United States : More than 200,000 people have died of COVID-19 in the country as of Tuesday ( Sept. 22 ) , according to .
After the virus first appeared in the U.S. in late January , it took four months to reach the first 100,000 deaths , which was reported on May 27 , and another four months to reach the second 100,000 deaths , according to .
COVID-19 is on track to be the third leading cause of death in the U.S. in 2020 , behind and cancer @ @ @ @ @ @ @ , U.S. COVID-19 deaths surpassed the number of accidental deaths ( which include those from overdoses , motor vehicle crashes and falls ) for 2018 , the most recent year that final death data is available , the NSC said .
Accidental deaths have been the third leading cause of death in the U.S. since 2016 .
The high number of COVID-19 deaths in the U.S. is a `` reflection of a failing national response , '' Dr. Tom Frieden , former director of the Centers for Disease Control and Prevention ( CDC @ @ @ @ @ @ @ that the actual number of COVID-19 deaths in the U.S. is higher than the reported tally .
Data from the CDC show that there have been between 202,000 and 263,000 excess deaths in the U.S. since February , according to Bloomberg .
Excess deaths refers to the number of deaths beyond what would be expected based on historical trends .
`` These are lives that have been lost and jobs that have been lost because we have n't had an organized , consistent , coherent federal response , '' Frieden told CNN .
@ @ @ @ @ @ @ than anywhere else in the world , at 200,005 deaths , followed by Brazil , with 137,272 deaths , and India , with 88,935 deaths , according to Johns Hopkins University .
The U.S. also leads the world in COVID-19 cases , with 6.8 million cases .

Nurses and healthcare workers mourn and remember their colleagues who died of COVID-19 during a demonstration outside Mount Sinai Hospital in Manhattan on April 10, 2020.
The coronavirus pandemic has reached another bleak milestone in the United States: More than 200,000 people have died of COVID-19 in the country as of Tuesday (Sept. 22), according to Johns Hopkins University .
After the virus first appeared in the U.S. in late January, it took four months to reach the first 100,000 deaths, which was reported on May 27, and another four months to reach the second 100,000 deaths, according to Bloomberg .
COVID-19 is on track to be the third leading cause of death in the U.S. in 2020, behind heart disease and cancer, according to the National Safety Council (NSC) . In August, U.S. COVID-19 deaths surpassed the number of accidental deaths (which include those from overdoses, motor vehicle crashes and falls) for 2018, the most recent year that final death data is available, the NSC said. Accidental deaths have been the third leading cause of death in the U.S. since 2016.
The high number of COVID-19 deaths in the U.S. is a "reflection of a failing national response," Dr. Tom Frieden, former director of the Centers for Disease Control and Prevention (CDC), told CNN last week. Frieden noted that the actual number of COVID-19 deaths in the U.S. is higher than the reported tally. Data from the CDC show that there have been between 202,000 and 263,000 excess deaths in the U.S. since February, according to Bloomberg. Excess deaths refers to the number of deaths beyond what would be expected based on historical trends.
"These are lives that have been lost and jobs that have been lost because we haven't had an organized, consistent, coherent federal response," Frieden told CNN.
The U.S. has reported more COVID-19 deaths than anywhere else in the world, at 200,005 deaths, followed by Brazil, with 137,272 deaths, and India, with 88,935 deaths, according to Johns Hopkins University. The U.S. also leads the world in COVID-19 cases, with 6.8 million cases.
Originally published on Live Science.


livescience--2020-09-22--350 elephants killed by 'a combination of neurotoxins' in water, Botswana government says

Scientists in Botswana may finally know why more than in the country 's Okavango Delta wetlands since May .
The culprit — or one of them , anyway — appears to be neurotoxins spread by thriving colonies of bacteria living in the region 's water holes .
`` Our latest tests have detected cyanobacterial neurotoxins to be the cause of deaths , '' Mmadi Reuben , principal veterinary officer at the Botswana department of wildlife and national parks , said during a news conference Monday ( Sept. 21 ) .
`` However , we have many questions still to be @ @ @ @ @ @ @ only and why that area only . ''
More than 70 % of the fallen were found near water sources polluted with large amounts of cyanobacteria — a single-cell organism also known as blue-green , named for their tendency to clump together in large green mats or `` blooms '' on aquatic surfaces .
These blooms can be hazardous or even deadly , harboring toxins that attack the , skin or liver of animals exposed to them .
Toxic cyanobacteria blooms have previously caused the mass dieoffs of fish , birds and other @ @ @ @ @ @ @ in the journal .
Cyanobacteria use photosynthesis to make food from sunlight .
This means they often thrive during summer heat waves when they can outcompete other types of algae , according to the 2008 study .
As global climate change increases the frequency and severity of heat waves ( 2020 brought the recorded in the Northern Hemisphere ) , algal blooms are becoming more widespread , and so have their toxins .
According to Reuben , the Botswana government 's investigation revealed `` a combination of neurotoxins '' in the watering holes @ @ @ @ @ @ @ other species seem to have fallen victim to these toxins ( save for one horse ) , it 's possible that the elephants are particularly susceptible because they spend a lot of time bathing in the holes and drinking large quantities of water from them , .
Tissue samples taken from the affected elephants are still being analyzed by lab partners in the United States , U.K. and South Africa , Reuben added .
Niall McCann , director of conservation at U.K.-based charity National Park Rescue , that officials should refrain from drawing @ @ @ @ @ @ @ .
`` Just because cyanobacteria were found in the water , that does not prove that the elephants died from exposure to those toxins , '' McCann said .
`` Without good samples from dead elephants , all hypotheses are just that : hypotheses . ''
One that has already been ruled out : poaching .
All 350 elephants were found with tusks intact , suggesting that ivory poachers were not responsible .
That 's reassuring , as Botswana supports a population of about 130,000 elephants , more than any other country in @ @ @ @ @ @ @ delta where these carcasses were found is home to about 15,000 of those elephants .

Some of the elephants were seen walking in circles before collapsing face-first into the earth in Botswana.
Scientists in Botswana may finally know why more than 350 elephants have mysteriously dropped dead in the country's Okavango Delta wetlands since May. The culprit — or one of them, anyway — appears to be neurotoxins spread by thriving colonies of bacteria living in the region's water holes.
"Our latest tests have detected cyanobacterial neurotoxins to be the cause of deaths," Mmadi Reuben, principal veterinary officer at the Botswana department of wildlife and national parks, said during a news conference Monday (Sept. 21). "However, we have many questions still to be answered, such as why the elephants only and why that area only."
More than 70% of the fallen elephants were found near water sources polluted with large amounts of cyanobacteria — a single-cell organism also known as blue-green algae , named for their tendency to clump together in large green mats or "blooms" on aquatic surfaces. These blooms can be hazardous or even deadly, harboring toxins that attack the nervous system , skin or liver of animals exposed to them. Toxic cyanobacteria blooms have previously caused the mass dieoffs of fish, birds and other animals, according to a 2008 study in the journal Global Change Biology .
Cyanobacteria use photosynthesis to make food from sunlight. This means they often thrive during summer heat waves when they can outcompete other types of algae, according to the 2008 study. As global climate change increases the frequency and severity of heat waves (2020 brought the hottest summer ever recorded in the Northern Hemisphere), algal blooms are becoming more widespread, and so have their toxins .
According to Reuben, the Botswana government's investigation revealed "a combination of neurotoxins" in the watering holes near the dead elephants. While no other species seem to have fallen victim to these toxins (save for one horse), it's possible that the elephants are particularly susceptible because they spend a lot of time bathing in the holes and drinking large quantities of water from them, Live Science previously reported .
Tissue samples taken from the affected elephants are still being analyzed by lab partners in the United States, U.K. and South Africa, Reuben added. Niall McCann, director of conservation at U.K.-based charity National Park Rescue, told The Guardian that officials should refrain from drawing any conclusions until those results are in.
"Just because cyanobacteria were found in the water, that does not prove that the elephants died from exposure to those toxins," McCann said. "Without good samples from dead elephants, all hypotheses are just that: hypotheses."
One hypothesis that has already been ruled out: poaching. All 350 elephants were found with tusks intact, suggesting that ivory poachers were not responsible. That's reassuring, as Botswana supports a population of about 130,000 elephants, more than any other country in Africa, according to the African Wildlife Foundation . The delta where these carcasses were found is home to about 15,000 of those elephants.
Originally published on Live Science.


livescience--2020-09-22--RV-size asteroid to get closer to Earth than the moon

An will get awfully close to this Thursday ( Sept. 24 ) , when it whizzes by our planet closer than the moon orbits .
The asteroid — known as 2020 SW — is n't expected to collide with Earth , according to the Center for Near Earth Object Studies ( CNEOS ) at the Jet Propulsion Laboratory in Pasadena , California .
But it will get close , passing about 16,700 miles ( 27,000 kilometers ) away from Earth , according to the Virtual Telescope Project .
To put this in perspective , the moon hangs out at an @ @ @ @ @ @ @ us , or about 30 Earths away .
This asteroid will pass at a distance of about 2.1 Earths .
This means that asteroid 2020 SW will pass even closer than TV and weather satellites , which orbit at about 22,300 miles ( 35,888 km ) away from Earth , .
Scientists have yet to pin down the asteroid 's exact size , but it 's not that large , likely between 14 feet and 32 feet ( 4.4 and 9.9 meters ) long , according to CNEOS .
This potentially RV-size asteroid @ @ @ @ @ @ @ Sept. 18 , by the Mount Lemmon Survey in Arizona , and announced the next day by the , a NASA-funded group that monitors minor planets , comets and natural satellites .
( It 's not unusual to find unknown asteroids ; in September alone , the Minor Planet Center has announced the discovery of 244 near-Earth objects . )
Passing by Earth will actually be a life-changing event for asteroid 2020 SW .
It 's such a small asteroid that Earth 's is expected to change the space rock 's course when @ @ @ @ @ @ @ a.m. EDT ( 11:18 UTC ) , according to EarthSky .
After asteroid 2020 SW 's close shave with Earth , it wo n't pay our planet another visit until June 3 , 2029 , according to the Jet Propulsion Laboratory .
That said , the asteroid is certainly rushing to see us this Thursday ( we hope it has a face mask ) , traveling at a velocity of about 17,200 mph ( 27,720 km/h , or 7.7 km/second ) relative to Earth , the Jet Propulsion Laboratory reported .
The asteroid @ @ @ @ @ @ @ , but it wo n't be visible to the naked eye .
If you want a clear view of the space rock , visit website , which is showing a live feed starting at 6 p.m. EDT ( 22:00 UTC ) on Wednesday , Sept. 23 .

An asteroid will get awfully close to Earth this Thursday (Sept. 24), when it whizzes by our planet closer than the moon orbits.
The asteroid — known as 2020 SW — isn't expected to collide with Earth, according to the Center for Near Earth Object Studies (CNEOS) at the Jet Propulsion Laboratory in Pasadena, California. But it will get close, passing about 16,700 miles (27,000 kilometers) away from Earth, according to the Virtual Telescope Project .
To put this in perspective, the moon hangs out at an average of 238,900 miles (384,000 km) from us, or about 30 Earths away. This asteroid will pass at a distance of about 2.1 Earths. This means that asteroid 2020 SW will pass even closer than TV and weather satellites, which orbit at about 22,300 miles (35,888 km) away from Earth, according to EarthSky .
Related: Top 10 ways to destroy Earth
Scientists have yet to pin down the asteroid's exact size, but it's not that large, likely between 14 feet and 32 feet (4.4 and 9.9 meters) long, according to CNEOS. This potentially RV-size asteroid was discovered only last week, on Sept. 18, by the Mount Lemmon Survey in Arizona, and announced the next day by the Minor Planet Center , a NASA-funded group that monitors minor planets, comets and natural satellites. (It's not unusual to find unknown asteroids; in September alone, the Minor Planet Center has announced the discovery of 244 near-Earth objects.)
The orbit of asteroid 2020 SW is seen here (in gray). (Image credit: JPL/NASA)
Passing by Earth will actually be a life-changing event for asteroid 2020 SW. It's such a small asteroid that Earth's gravity is expected to change the space rock's course when it zooms by our planet at 7:18 a.m. EDT (11:18 UTC), according to EarthSky.
After asteroid 2020 SW's close shave with Earth, it won't pay our planet another visit until June 3, 2029, according to the Jet Propulsion Laboratory.
That said, the asteroid is certainly rushing to see us this Thursday (we hope it has a face mask), traveling at a velocity of about 17,200 mph (27,720 km/h, or 7.7 km/second) relative to Earth, the Jet Propulsion Laboratory reported.
The asteroid will appear brighter as it nears Earth, but it won't be visible to the naked eye. If you want a clear view of the space rock, visit The Virtual Telescope website, which is showing a live feed starting at 6 p.m. EDT (22:00 UTC) on Wednesday, Sept. 23.
Originally published on Live Science.


livescience--2020-09-22--Why do we sleep? The answer may change right before we turn 3.

Humans spend about a third of our lives sleeping , and scientists have long debated why slumber takes up such a huge slice of our time .
Now , a new study hints that our main reason for sleeping starts off as one thing , then changes at a surprisingly specific age .
Two leading theories as to why we sleep focus on the : One theory says that the uses sleep to reorganize the connections between its cells , building electrical networks that support our and ability to learn ; the other theory says that the brain needs time @ @ @ @ @ @ @ accumulates throughout the day .
Neuroscientists have quibbled over which of these functions is the main reason for sleep , but the new study reveals that the answer may be different for babies and adults .
In the study , published Sep. 18 in the journal , researchers use a mathematical model to show that infants spend most of their sleeping hours in `` deep sleep , '' also known as , while their brains rapidly build new connections between cells and grow ever larger .
Then , just before toddlers reach age @ @ @ @ @ @ @ dips dramatically as the brain switches into maintenance mode , mostly using sleep time for cleaning and repair .
`` It was definitely shocking to us that this transition was so sharp , '' from growth mode to maintenance mode , senior author Van Savage , a professor of ecology and evolutionary biology and of computational medicine at the University of California , Los Angeles and the Santa Fe Institute , told Live Science in an email .
The researchers also collected data in other mammals — namely , rats and guinea pigs @ @ @ @ @ @ @ undergo a similar transformation ; however , it 's too soon to tell whether these patterns are consistent across many species .
That said , `` I think in actuality , it may not be really so sharp '' a transition , said Leila Tarokh , a neuroscientist and Group Leader at the University Hospital of Child and Adolescent Psychiatry and Psychotherapy at the University of Bern , who was not involved in the study .
The pace of brain development varies widely between individuals , and the researchers had fairly `` sparse @ @ @ @ @ @ @ 2 and 3 , she said .
If they studied individuals through time as they aged , they might find that the transition is less sudden and more smooth , or the age of transition may vary between individuals , she said .
In a previous study , published in 2007 in the journal Proceedings of the National Academy of Sciences , Savage and theoretical physicist Geoffrey West found that an animal 's brain size and brain metabolic rate accurately predict the amount of time the animal sleeps — more so than the @ @ @ @ @ @ @ general , big animals with big brains and low brain metabolic rates sleep less than small animals with the opposite features .
This rule holds up across different species and between members of the same species ; for instance , mice sleep more than , and newborn babies sleep more than adult humans .
However , knowing that sleep time decreases as brains get bigger , the authors wondered how quickly that change occurs in different animals , and whether that relates to the function of sleep over time .
To begin answering @ @ @ @ @ @ @ data on how much humans sleep , compiling several hundred data points from newborn babies and children up to age 15 .
They also gathered data on brain size and metabolic rate , the density of connections between brain cells , body size and metabolic rate , and the ratio of time spent in REM sleep versus non-REM sleep at different ages ; the researchers drew these data points from more than 60 studies , overall .
sleep about twice as much as adults , and they spend a larger proportion of their @ @ @ @ @ @ @ 's been a long-standing question as to what function that serves , Tarokh noted .
The study authors built a mathematical model to track all these shifting data points through time and see what patterns emerged between them .
They found that the metabolic rate of the brain was high during infancy when the organ was building many new connections between cells , and this in turn correlated with more time spent in REM sleep .
They concluded that the long hours of REM in infancy support rapid remodeling in the brain , @ @ @ @ @ @ @ up new skills .
Then , between age 2 and 3 , `` the connections are not changing nearly as quickly , '' and the amount of time spent in REM diminishes , Savage said .
At this time , the metabolic rate of cells in the cerebral cortex — the wrinkled surface of the brain — also changes .
In infancy , the metabolic rate is proportional to the number of existing connections between brain cells plus the energy needed to fashion new connections in the network .
As the rate of @ @ @ @ @ @ @ slows in turn .
`` In the first few years of life , you see that the brain is making tons of new connections … it 's blossoming , and that 's why we see all those skills coming on , '' Tarokh said .
Developmental psychologists refer to this as a `` critical period '' of neuroplasticity — the ability of the brain to forge new connections between its cells .
`` It 's not that plasticity goes away '' after that critical period , but the construction of new connections slows @ @ @ @ @ @ @ suggests , Tarokh said .
At the same time , the ratio of non-REM to REM sleep increases , supporting the idea that non-REM is more important to brain maintenance than neuroplasticity .
Looking forward , the authors plan to apply their mathematical model of sleep to other animals , to see whether a similar switch from reorganization to repair occurs early in development , Savage said .
`` Humans are known to be unusual in the amount of brain development that occurs after birth , '' lead author Junyu Cao , an @ @ @ @ @ @ @ , Risk , and Operations Management at The University of Texas at Austin , told Live Science in an email .
( Cao played a key role in compiling data and performing computations for the report . )
`` Therefore , it is conceivable that the phase transition described here for humans may occur earlier in other species , possibly even before birth . ''
In terms of human sleep , Tarokh noted that different patterns of electrical activity , known as oscillations , occur in REM versus non-REM sleep ; future studies @ @ @ @ @ @ @ shape the brain as we age , given that the amount of time spent in REM changes , she said .
Theoretically , disruptions in these patterns could contribute to developmental disorders that emerge in infancy and early childhood , she added — but again , that 's just a hypothesis .

Humans spend about a third of our lives sleeping, and scientists have long debated why slumber takes up such a huge slice of our time. Now, a new study hints that our main reason for sleeping starts off as one thing, then changes at a surprisingly specific age.
Two leading theories as to why we sleep focus on the brain : One theory says that the brain uses sleep to reorganize the connections between its cells, building electrical networks that support our memory and ability to learn; the other theory says that the brain needs time to clean up the metabolic waste that accumulates throughout the day. Neuroscientists have quibbled over which of these functions is the main reason for sleep, but the new study reveals that the answer may be different for babies and adults.
In the study, published Sep. 18 in the journal Science Advances , researchers use a mathematical model to show that infants spend most of their sleeping hours in "deep sleep," also known as random eye movement (REM) sleep , while their brains rapidly build new connections between cells and grow ever larger. Then, just before toddlers reach age 2-and-a-half, their amount of REM sleep dips dramatically as the brain switches into maintenance mode, mostly using sleep time for cleaning and repair.
Related: 5 surprising sleep discoveries
"It was definitely shocking to us that this transition was so sharp," from growth mode to maintenance mode, senior author Van Savage, a professor of ecology and evolutionary biology and of computational medicine at the University of California, Los Angeles and the Santa Fe Institute, told Live Science in an email. The researchers also collected data in other mammals — namely rabbits , rats and guinea pigs — and found that their sleep might undergo a similar transformation; however, it's too soon to tell whether these patterns are consistent across many species.
That said, "I think in actuality, it may not be really so sharp" a transition, said Leila Tarokh, a neuroscientist and Group Leader at the University Hospital of Child and Adolescent Psychiatry and Psychotherapy at the University of Bern, who was not involved in the study. The pace of brain development varies widely between individuals, and the researchers had fairly "sparse" data points between the ages of 2 and 3, she said. If they studied individuals through time as they aged, they might find that the transition is less sudden and more smooth, or the age of transition may vary between individuals, she said.
An emerging hypothesis
In a previous study, published in 2007 in the journal Proceedings of the National Academy of Sciences , Savage and theoretical physicist Geoffrey West found that an animal's brain size and brain metabolic rate accurately predict the amount of time the animal sleeps — more so than the animal's overall body size. In general, big animals with big brains and low brain metabolic rates sleep less than small animals with the opposite features.
This rule holds up across different species and between members of the same species; for instance, mice sleep more than elephants , and newborn babies sleep more than adult humans. However, knowing that sleep time decreases as brains get bigger, the authors wondered how quickly that change occurs in different animals, and whether that relates to the function of sleep over time.
To begin answering these questions, the researchers pooled existing data on how much humans sleep, compiling several hundred data points from newborn babies and children up to age 15. They also gathered data on brain size and metabolic rate, the density of connections between brain cells, body size and metabolic rate, and the ratio of time spent in REM sleep versus non-REM sleep at different ages; the researchers drew these data points from more than 60 studies, overall.
Babies sleep about twice as much as adults, and they spend a larger proportion of their sleep time in REM, but there's been a long-standing question as to what function that serves, Tarokh noted.
Related: From dino brains to thought control — 10 fascinating brain findings
The study authors built a mathematical model to track all these shifting data points through time and see what patterns emerged between them. They found that the metabolic rate of the brain was high during infancy when the organ was building many new connections between cells, and this in turn correlated with more time spent in REM sleep. They concluded that the long hours of REM in infancy support rapid remodeling in the brain, as new networks form and babies pick up new skills. Then, between age 2 and 3, "the connections are not changing nearly as quickly," and the amount of time spent in REM diminishes, Savage said.
At this time, the metabolic rate of cells in the cerebral cortex — the wrinkled surface of the brain — also changes. In infancy, the metabolic rate is proportional to the number of existing connections between brain cells plus the energy needed to fashion new connections in the network. As the rate of construction slows, the relative metabolic rate slows in turn.
"In the first few years of life, you see that the brain is making tons of new connections … it's blossoming, and that's why we see all those skills coming on," Tarokh said. Developmental psychologists refer to this as a "critical period" of neuroplasticity — the ability of the brain to forge new connections between its cells. "It's not that plasticity goes away" after that critical period, but the construction of new connections slows significantly, as the new mathematical model suggests, Tarokh said. At the same time, the ratio of non-REM to REM sleep increases, supporting the idea that non-REM is more important to brain maintenance than neuroplasticity.
Looking forward, the authors plan to apply their mathematical model of sleep to other animals, to see whether a similar switch from reorganization to repair occurs early in development, Savage said.
"Humans are known to be unusual in the amount of brain development that occurs after birth," lead author Junyu Cao, an assistant professor in the Department of Information, Risk, and Operations Management at The University of Texas at Austin, told Live Science in an email. (Cao played a key role in compiling data and performing computations for the report.) "Therefore, it is conceivable that the phase transition described here for humans may occur earlier in other species, possibly even before birth."
In terms of human sleep, Tarokh noted that different patterns of electrical activity, known as oscillations, occur in REM versus non-REM sleep; future studies could reveal whether and how particular oscillations shape the brain as we age, given that the amount of time spent in REM changes, she said. Theoretically, disruptions in these patterns could contribute to developmental disorders that emerge in infancy and early childhood, she added — but again, that's just a hypothesis.
Originally published on Live Science.