scientificamerican--2020-10-21--Restoring Seagrass Brings Barren Bays To Life

The following essay is reprinted with permission from The Conversation , an online publication covering the latest research .
A century ago Virginia ’ s coastal lagoons were a natural paradise .
Fishing boats bobbed on the waves as geese flocked overhead .
Beneath the surface , miles of seagrass gently swayed in the surf , making the seabed look like a vast underwater prairie .
More than 70 species of seagrasses grow in shallow waters around the world , on every continent except Antarctica .
In Virginia , beds of eelgrass ( Zostera marina ) provided habitat for bay @ @ @ @ @ @ @ kept barrier islands from washing away .
Eelgrass was so common that people who lived near the shore packed and baled it to use as insulation for homes , schools and hospitals .
In the 1930s , however , pandemic plant disease and repeated hurricanes eliminated the eelgrass along Virginia ’ s eastern shore .
The once-vibrant seafloor became barren mud , leading to a loss of “ wildfowl , the cream of salt-water fishing , most of the clams and crabs , and all of the bay scallops , ” sportsman and @ @ @ @ @ @ @ .
We are marine scientists who study seagrasses , marine biodiversity and coastal ecosystems .
In a newly published study , we describe the results of a 20-year mission to reintroduce eelgrass into Virginia coastal bays using a novel seed-based approach .
This project has now restored 9,600 acres of seagrasses across four bays—one of the most successful marine restoration efforts anywhere in the world .
It has triggered large increases in fishes and invertebrates , made the water clearer and trapped large quantities of carbon in seafloor sediments , helping to slow @ @ @ @ @ @ @ as a blueprint for restoring and maintaining healthy ecosystems along coastlines around the world .
Development , nutrient runoff and other human impacts have damaged marshes , mangroves , coral reefs and seagrasses in many bays and estuaries worldwide .
Loss or shrinkage of these key habitats has reduced commercial fisheries , increased erosion , made coastlines more vulnerable to floods and storms and harmed many types of aquatic life .
Rapid climate change has compounded these effects through rising global temperatures , more frequent and severe storms and ocean acidification .
In @ @ @ @ @ @ @ two of us who are longtime students of seagrasses ( Robert “ JJ ” Orth and Karen McGlathery ) that they had spotted small patches of eelgrass in shallow waters off Virginia ’ s eastern shore .
For years the conventional view had been that seagrasses in this area had not recovered from the events of the 1930s because human activities had made the area inhospitable for them .
But studies showed that water quality in these coastal bays was comparatively good .
This led us to explore a different explanation : Seeds @ @ @ @ @ @ @ Atlantic coast simply weren ’ t reaching these isolated bays .
Seagrasses are underwater flowering plants , so seeds are among the main ways they reproduce and spread to new environments .
From our earlier research , we knew that when eelgrass seeds fall from the parent plant , they sink to the sea bottom quickly and don ’ t move far from where they land .
We also knew that these seeds don ’ t germinate until late fall or early winter .
This meant that if we collected the seeds in @ @ @ @ @ @ @ could hold them until the fall , helping them survive over the months in between .
We decided to try reseeding eelgrass in the areas where they were missing .
Starting in 1999 , we collected seeds by hand from underwater meadows in nearby Chesapeake Bay—plucking the long reproductive shoots , bringing them back to our laboratory and holding them in large outdoor seawater tanks until they released their seeds naturally .
After about 10 years we started gathering the grasses using a custom-built underwater “ lawn mower ” to collect many more @ @ @ @ @ @ @ by hand .
In 2001 we sowed our first round by simply tossing seeds from a boat .
Our first test plots covered 28 acres of mud flats in waters 2 to 3 feet deep .
Returning the following year , we saw new seedlings sprouting up .
Each year since then , the Virginia Institute of Marine Science and the Nature Conservancy ’ s Virginia Coast Reserve , along with staff and students from the University of Virginia , have led a team of scientists and citizens to collect and seed a @ @ @ @ @ @ @ several coastal bays .
These initial plots took off and rapidly expanded .
By 2020 they covered 9,600 acres across four bays .
Several factors helped them flourish .
These bays are naturally flushed with cool , clean water from the Atlantic Ocean .
And they lie off the tip of Virginia ’ s eastern shore , where there is little coastal development .
Since eelgrass disappeared from these bays in the 1930s , human understanding of seagrass ecosystems has evolved .
Today people don ’ t pack their walls full of seagrass @ @ @ @ @ @ @ provide , such as habitat for fish and shellfish—including many commercially and recreationally important species .
Scientists and government agencies also have recognized the importance of coastal systems in capturing and storing so-called “ blue carbon.
” In fact , we now know that seagrasses constitute a globally significant carbon sink .
They are a key tool for reducing carbon dioxide in the atmosphere and slowing climate change We are working to understand the valuable services that our restored seagrass beds provide .
To our surprise , fish and invertebrates returned within only @ @ @ @ @ @ @ .
These organisms have established extensive food webs that include species ranging from tiny seahorses to 6-foot-long sandbar sharks .
Other benefits were equally dramatic .
Water in the bays become clearer as the seagrass canopy trapped floating particles and deposited them onto the bottom , burying significant stocks of carbon and nitrogen in sediments bound by the grasses ’ roots .
Our research is the first to verify the overall net carbon captured by seagrass , and is now being used to issue carbon offset credits that in turn create more funds @ @ @ @ @ @ @ whether restoring seagrasses could make it possible to bring back bay scallops , which once generated millions of dollars for the local economy .
Since bay scallops no longer existed in Virginia , we obtained broodstock from North Carolina , which we have reared and released annually since 2013 .
Regular surveys now reveal a growing population of bay scallops in the restored eelgrass , although there is still some way to go before they reach levels seen in the 1930s .
Repairing damaged ecosystems is such an urgent mission worldwide that the @ @ @ @ @ @ @ U.N .
Decade on Ecosystem Restoration .
We see the success we have achieved with eelgrass restoration as a prime model for similar efforts in coastal areas around the world .
Our project focused not only on reviving this essential habitat , but also on charting how restoring seagrasses affected the ecosystem and on the co-restoration of bay scallops .
It provides a road map for involving scholars , nonprofits organizations , citizens and government agencies in an ecological mission where they can see the results of their work .
Recent assessments show @ @ @ @ @ @ @ 30 % of the total habitable bottom in our project area .
With continued support , eelgrass—and the many benefits it provides—may continue to thrive and expand well into the 21st century .
This article was originally published on The Conversation .
Read the original article .

The following essay is reprinted with permission from The Conversation, an online publication covering the latest research.
A century ago Virginia’s coastal lagoons were a natural paradise. Fishing boats bobbed on the waves as geese flocked overhead. Beneath the surface, miles of seagrass gently swayed in the surf, making the seabed look like a vast underwater prairie.
More than 70 species of seagrasses grow in shallow waters around the world, on every continent except Antarctica. In Virginia, beds of eelgrass (Zostera marina) provided habitat for bay scallops and food for birds, and kept barrier islands from washing away. Eelgrass was so common that people who lived near the shore packed and baled it to use as insulation for homes, schools and hospitals.
In the 1930s, however, pandemic plant disease and repeated hurricanes eliminated the eelgrass along Virginia’s eastern shore. The once-vibrant seafloor became barren mud, leading to a loss of “wildfowl, the cream of salt-water fishing, most of the clams and crabs, and all of the bay scallops,” sportsman and publisher Eugene V. Connett wrote in 1947.
We are marine scientists who study seagrasses, marine biodiversity and coastal ecosystems. In a newly published study, we describe the results of a 20-year mission to reintroduce eelgrass into Virginia coastal bays using a novel seed-based approach.
This project has now restored 9,600 acres of seagrasses across four bays—one of the most successful marine restoration efforts anywhere in the world. It has triggered large increases in fishes and invertebrates, made the water clearer and trapped large quantities of carbon in seafloor sediments, helping to slow climate change. We see this work as a blueprint for restoring and maintaining healthy ecosystems along coastlines around the world.
Why didn’t seagrasses recover naturally?
Development, nutrient runoff and other human impacts have damaged marshes, mangroves, coral reefs and seagrasses in many bays and estuaries worldwide. Loss or shrinkage of these key habitats has reduced commercial fisheries, increased erosion, made coastlines more vulnerable to floods and storms and harmed many types of aquatic life. Rapid climate change has compounded these effects through rising global temperatures, more frequent and severe storms and ocean acidification.
In the late 1990s, local residents told two of us who are longtime students of seagrasses (Robert “JJ” Orth and Karen McGlathery) that they had spotted small patches of eelgrass in shallow waters off Virginia’s eastern shore. For years the conventional view had been that seagrasses in this area had not recovered from the events of the 1930s because human activities had made the area inhospitable for them.
But studies showed that water quality in these coastal bays was comparatively good. This led us to explore a different explanation: Seeds from healthy seagrass populations elsewhere along the Atlantic coast simply weren’t reaching these isolated bays. Seagrasses are underwater flowering plants, so seeds are among the main ways they reproduce and spread to new environments.
Sowing a new crop
From our earlier research, we knew that when eelgrass seeds fall from the parent plant, they sink to the sea bottom quickly and don’t move far from where they land. We also knew that these seeds don’t germinate until late fall or early winter. This meant that if we collected the seeds in spring, when eelgrass flowers, we could hold them until the fall, helping them survive over the months in between.
We decided to try reseeding eelgrass in the areas where they were missing. Starting in 1999, we collected seeds by hand from underwater meadows in nearby Chesapeake Bay—plucking the long reproductive shoots, bringing them back to our laboratory and holding them in large outdoor seawater tanks until they released their seeds naturally. After about 10 years we started gathering the grasses using a custom-built underwater “lawn mower” to collect many more of the reproductive shoots than we could by hand.
In 2001 we sowed our first round by simply tossing seeds from a boat. Our first test plots covered 28 acres of mud flats in waters 2 to 3 feet deep. Returning the following year, we saw new seedlings sprouting up.
Each year since then, the Virginia Institute of Marine Science and the Nature Conservancy’s Virginia Coast Reserve, along with staff and students from the University of Virginia, have led a team of scientists and citizens to collect and seed a combined 536 acres of bare bottom in several coastal bays.
These initial plots took off and rapidly expanded. By 2020 they covered 9,600 acres across four bays. Several factors helped them flourish. These bays are naturally flushed with cool, clean water from the Atlantic Ocean. And they lie off the tip of Virginia’s eastern shore, where there is little coastal development.
Sheltering marine life and storing carbon
Since eelgrass disappeared from these bays in the 1930s, human understanding of seagrass ecosystems has evolved. Today people don’t pack their walls full of seagrass insulation but instead value different services they provide, such as habitat for fish and shellfish—including many commercially and recreationally important species.
Scientists and government agencies also have recognized the importance of coastal systems in capturing and storing so-called “blue carbon.” In fact, we now know that seagrasses constitute a globally significant carbon sink. They are a key tool for reducing carbon dioxide in the atmosphere and slowing climate change
We are working to understand the valuable services that our restored seagrass beds provide. To our surprise, fish and invertebrates returned within only a few years as the meadows expanded. These organisms have established extensive food webs that include species ranging from tiny seahorses to 6-foot-long sandbar sharks.
Other benefits were equally dramatic. Water in the bays become clearer as the seagrass canopy trapped floating particles and deposited them onto the bottom, burying significant stocks of carbon and nitrogen in sediments bound by the grasses’ roots. Our research is the first to verify the overall net carbon captured by seagrass, and is now being used to issue carbon offset credits that in turn create more funds for restoration.
One big question was whether restoring seagrasses could make it possible to bring back bay scallops, which once generated millions of dollars for the local economy. Since bay scallops no longer existed in Virginia, we obtained broodstock from North Carolina, which we have reared and released annually since 2013. Regular surveys now reveal a growing population of bay scallops in the restored eelgrass, although there is still some way to go before they reach levels seen in the 1930s.
A model for coastal restoration
Repairing damaged ecosystems is such an urgent mission worldwide that the United Nations has designated 2021-2030 as the U.N. Decade on Ecosystem Restoration. We see the success we have achieved with eelgrass restoration as a prime model for similar efforts in coastal areas around the world.
Our project focused not only on reviving this essential habitat, but also on charting how restoring seagrasses affected the ecosystem and on the co-restoration of bay scallops. It provides a road map for involving scholars, nonprofits organizations, citizens and government agencies in an ecological mission where they can see the results of their work.
Recent assessments show that the restored zone only covers about 30% of the total habitable bottom in our project area. With continued support, eelgrass—and the many benefits it provides—may continue to thrive and expand well into the 21st century.
This article was originally published on The Conversation. Read the original article.


scientificamerican--2020-10-22--Social Media Restrictions Cannot Keep Up with Hidden Codes and Symbols

On the same day that President Donald Trump announced his COVID-19 diagnosis , Twitter reminded users of its policy that “ tweets that wish or hope for death , serious bodily harm or fatal disease against *anyone* are not allowed and will need to be removed.
” The social media platform soon filled with posts accusing it of hypocrisy : threats targeting women and people of color have accumulated for years without removal , users said .
But even as Twitter attempted to enforce its rules more stringently , thinly veiled posts slipped through the cracks .
By referencing schadenfreude @ @ @ @ @ @ @ you reap what you sow ” in reference to Trump ’ s illness , many Twitter users avoided explicitly violating the site ’ s abuse policy while leaving no doubt as to their intended sentiment .
Scholars who study social media discourse say this incident reflects a broader phenomenon : Whenever online authorities ( whether social media platforms or governments ) attempt to restrict speech on the Internet , people will find creative ways to subvert the rules .
These strategies can be used to spread abuse—or to preserve freedom of expression .
@ @ @ @ @ @ @ , prohibits social media posts referencing June 4 , the anniversary of the 1989 Tiananmen Square crackdown that killed an unknown number of Chinese pro-democracy protesters and their sympathizers .
In the early days of Chinese microblogging platform Sina Weibo , users sidestepped the ban by referring to “ May 35 ” instead .
“ But eventually [ the censors ] caught up with that , and they banned that , too , ” says Susan Herring , a linguist at Indiana University Bloomington who studies technology-mediated communication .
“ It ’ s @ @ @ @ @ @ @ censors ... .
The people are constantly coming up with creative new symbols.
” The use of symbolism to avoid censorship is as old as language itself .
In the antebellum U.S. , Harriet Tubman communicated with fugitives escaping slavery by singing songs with hidden meanings that their pursuers would not understand .
When homosexuality was illegal in the 20th-century U.K. , members of the gay subculture used a secret slang called Polari .
Herring says the cycle of code making and code breaking “ is a major driver of language change.
” @ @ @ @ @ @ @ words known as verlan are created by transposing the syllables of an existing word .
Because many verlan terms originated as a secret code to discuss illicit behavior , the process was often repeated when a new form became too recognizable .
In this way , femme ( the standard word for “ woman ” ) gave rise to meuf , which in turn became feumeu .
Analogously , online coded symbols evolve as their previously secret meanings become well-known .
On the Internet , such symbols can manifest as words or visual @ @ @ @ @ @ @ other images .
The specific form of a symbol ultimately matters less than the idea it represents , says Ryan Milner , who studies Internet culture at the College of Charleston .
But he notes that visual symbols have proved particularly effective at evading censorship , thanks to their inherent ambiguity .
And their power to spread rapidly online derives from their ability to establish an in-group and out-group .
“ As they get more esoteric , as they get more inside jokey , then there ’ s more and more of a @ @ @ @ @ @ @ , if you ’ re part of the joke—then you are one of us , ’ ” Milner says , “ and ‘ if you don ’ t get it ... , then you ’ re not one of us.
” Pepe the Frog exemplifies the capacity of memes to both foment hate and defy oppression .
The meme began life as an innocent cartoon amphibian , but as it grew in popularity , users of the online message boards 4chan , 8chan and Reddit began making anti-Semitic and racist versions of it @ @ @ @ @ @ @ gained such widespread use among white supremacists in the U.S. that the Anti-Defamation League declared it a hate symbol .
In 2019 , however , pro-democracy protestors in Hong Kong—mostly unaware of Pepe ’ s associations with white supremacy—adopted the image to symbolize their movement .
In both cases the meme ’ s coded meaning allowed it to spread uncensored , eventually garnering widespread recognition that elevated the public profile of the groups using it .
For many visual symbols , “ there is this consistent push-pull ” between recognizability and secrecy , @ @ @ @ @ @ @ persuade , “ publicity is going to be good , ” he adds .
But for those seeking a clandestine “ knowing wink , ” too much attention can undercut a symbol ’ s effectiveness .
The latter fate befell the “ grass mud horse , ” a fictional alpacalike creature whose name in Mandarin is a pun for an obscene and insulting phrase that sounds similar if the spoken tones are minimally altered .
The grass mud horse originated in 2009 as an icon of resistance to China ’ s Internet censorship @ @ @ @ @ @ @ plausible deniability—they could claim they were merely sharing a funny picture of an animal , says Sulafa Zidani , a global media studies scholar at the University of Southern California .
But as the meme ’ s popularity exploded , its underlying meaning became common knowledge , thus diluting its power .
In 2014 digital media scholar An Xiao Mina noted that the grass mud horse had been included among Sina Weibo ’ s official emoji—effectively transforming it from a symbol of subversion to a general-purpose obscenity .
In the U.S. , 2020 @ @ @ @ @ @ @ over the meanings of coded symbols and phrases , Milner says .
The extremist antigovernment “ boogaloo ” movement hijacked Hawaiian shirts .
Followers of the QAnon conspiracy theory co-opted the phrase “ save the children ” from a legitimate antitrafficking campaign .
The ambiguity of these symbols “ absolutely ” helps such groups evade censorship on social media , says Howard Graves , a senior research analyst at the Southern Poverty Law Center .
Graves emphasizes that “ context is crucial ” when interpreting a symbol .
For instance , in June @ @ @ @ @ @ @ the hashtag # WhiteLivesMatter with memes and videos of K-pop stars to drown out racist posts using it .
In October they repeated the tactic with the # ArmyForTrump .
Although coded language and symbols are nothing new , social media has transformed their impact on culture .
“ The ability to make a coordinated attempt ... to claim a symbol as your own is something that you can do in a wide-scale way because of social media tools , ” Milner says .
And whether or not those symbols incite violence or @ @ @ @ @ @ @ we as individuals have a lot of power to amplify certain messages—and not amplify other messages .
”

On the same day that President Donald Trump announced his COVID-19 diagnosis, Twitter reminded users of its policy that “tweets that wish or hope for death, serious bodily harm or fatal disease against *anyone* are not allowed and will need to be removed.” The social media platform soon filled with posts accusing it of hypocrisy: threats targeting women and people of color have accumulated for years without removal, users said. But even as Twitter attempted to enforce its rules more stringently, thinly veiled posts slipped through the cracks.
By referencing schadenfreude, karma or the old adage “you reap what you sow” in reference to Trump’s illness, many Twitter users avoided explicitly violating the site’s abuse policy while leaving no doubt as to their intended sentiment. Scholars who study social media discourse say this incident reflects a broader phenomenon: Whenever online authorities (whether social media platforms or governments) attempt to restrict speech on the Internet, people will find creative ways to subvert the rules. These strategies can be used to spread abuse—or to preserve freedom of expression.
China’s government, for instance, prohibits social media posts referencing June 4, the anniversary of the 1989 Tiananmen Square crackdown that killed an unknown number of Chinese pro-democracy protesters and their sympathizers. In the early days of Chinese microblogging platform Sina Weibo, users sidestepped the ban by referring to “May 35” instead. “But eventually [the censors] caught up with that, and they banned that, too,” says Susan Herring, a linguist at Indiana University Bloomington who studies technology-mediated communication. “It’s a race to try to fool the censors.... The people are constantly coming up with creative new symbols.”
Woman wears a helmet adorned with an image of Pepe the Frog that she hand-painted and a Trump/Pence sticker at a rally organized by the right-wing group Patriot Prayer in Vancouver, Wash., on September 10, 2017. Credit: Sylvia Buchholz and Elijah Nouvelage Alamy
The use of symbolism to avoid censorship is as old as language itself. In the antebellum U.S., Harriet Tubman communicated with fugitives escaping slavery by singing songs with hidden meanings that their pursuers would not understand. When homosexuality was illegal in the 20th-century U.K., members of the gay subculture used a secret slang called Polari. Herring says the cycle of code making and code breaking “is a major driver of language change.” In French, for instance, slang words known as verlan are created by transposing the syllables of an existing word. Because many verlan terms originated as a secret code to discuss illicit behavior, the process was often repeated when a new form became too recognizable. In this way, femme (the standard word for “woman”) gave rise to meuf, which in turn became feumeu. Analogously, online coded symbols evolve as their previously secret meanings become well-known.
On the Internet, such symbols can manifest as words or visual motifs, including emoji, memes or other images. The specific form of a symbol ultimately matters less than the idea it represents, says Ryan Milner, who studies Internet culture at the College of Charleston. But he notes that visual symbols have proved particularly effective at evading censorship, thanks to their inherent ambiguity. And their power to spread rapidly online derives from their ability to establish an in-group and out-group. “As they get more esoteric, as they get more inside jokey, then there’s more and more of a signal that ‘if you get this, if you’re part of the joke—then you are one of us,’” Milner says, “and ‘if you don’t get it..., then you’re not one of us.”
Pepe the Frog exemplifies the capacity of memes to both foment hate and defy oppression. The meme began life as an innocent cartoon amphibian, but as it grew in popularity, users of the online message boards 4chan, 8chan and Reddit began making anti-Semitic and racist versions of it. By 2016 Pepe the Frog had gained such widespread use among white supremacists in the U.S. that the Anti-Defamation League declared it a hate symbol. In 2019, however, pro-democracy protestors in Hong Kong—mostly unaware of Pepe’s associations with white supremacy—adopted the image to symbolize their movement. In both cases the meme’s coded meaning allowed it to spread uncensored, eventually garnering widespread recognition that elevated the public profile of the groups using it.
For many visual symbols, “there is this consistent push-pull” between recognizability and secrecy, Milner says. For groups aiming to persuade, “publicity is going to be good,” he adds. But for those seeking a clandestine “knowing wink,” too much attention can undercut a symbol’s effectiveness.
Protestor in Hong Kong waves a Pepe the Frog flag. Credit: Miguel Candela Getty Images
The latter fate befell the “grass mud horse,” a fictional alpacalike creature whose name in Mandarin is a pun for an obscene and insulting phrase that sounds similar if the spoken tones are minimally altered. The grass mud horse originated in 2009 as an icon of resistance to China’s Internet censorship. At first people using it had plausible deniability—they could claim they were merely sharing a funny picture of an animal, says Sulafa Zidani, a global media studies scholar at the University of Southern California. But as the meme’s popularity exploded, its underlying meaning became common knowledge, thus diluting its power. In 2014 digital media scholar An Xiao Mina noted that the grass mud horse had been included among Sina Weibo’s official emoji—effectively transforming it from a symbol of subversion to a general-purpose obscenity.
In the U.S., 2020 has seen many “ideological contestations” over the meanings of coded symbols and phrases, Milner says. The extremist antigovernment “boogaloo” movement hijacked Hawaiian shirts. Followers of the QAnon conspiracy theory co-opted the phrase “save the children” from a legitimate antitrafficking campaign. The ambiguity of these symbols “absolutely” helps such groups evade censorship on social media, says Howard Graves, a senior research analyst at the Southern Poverty Law Center. Graves emphasizes that “context is crucial” when interpreting a symbol. For instance, in June fans of South Korean pop music flooded the hashtag #WhiteLivesMatter with memes and videos of K-pop stars to drown out racist posts using it. In October they repeated the tactic with the #ArmyForTrump.
Although coded language and symbols are nothing new, social media has transformed their impact on culture. “The ability to make a coordinated attempt ... to claim a symbol as your own is something that you can do in a wide-scale way because of social media tools,” Milner says.
And whether or not those symbols incite violence or protest injustice, Zidani says, “we as individuals have a lot of power to amplify certain messages—and not amplify other messages.”


scientificamerican--2020-10-22--What We Know So Far about How COVID Affects the Nervous System

Many of the symptoms experienced by people infected with SARS-CoV-2 involve the nervous system .
Patients complain of headaches , muscle and joint pain , fatigue and “ brain fog , ” or loss of taste and smell—all of which can last from weeks to months after infection .
In severe cases , COVID-19 can also lead to encephalitis or stroke .
The virus has undeniable neurological effects .
But the way it actually affects nerve cells still remains a bit of a mystery .
Can immune system activation alone produce symptoms ?
Or does the novel coronavirus directly attack @ @ @ @ @ @ @ recent preprint paper examining mouse and human brain tissue—show evidence that SARS-CoV-2 can get into nerve cells and the brain .
The question remains as to whether it does so routinely or only in the most severe cases .
Once the immune system kicks into overdrive , the effects can be far-ranging , even leading immune cells to invade the brain , where they can wreak havoc .
Some neurological symptoms are far less serious yet seem , if anything , more perplexing .
One symptom—or set of symptoms—that illustrates this puzzle and @ @ @ @ @ @ @ diagnosis called “ brain fog.
” Even after their main symptoms have abated , it is not uncommon for COVID-19 patients to experience memory loss , confusion and other mental fuzziness .
What underlies these experiences is still unclear , although they may also stem from the body-wide inflammation that can go along with COVID-19 .
Many people , however , develop fatigue and brain fog that lasts for months even after a mild case that does not spur the immune system to rage out of control .
Another widespread symptom called anosmia @ @ @ @ @ @ @ also originate from changes that happen without nerves themselves getting infected .
Olfactory neurons , the cells that transmit odors to the brain , lack the primary docking site , or receptor , for SARS-CoV-2 , and they do not seem to get infected .
Researchers are still investigating how loss of smell might result from an interaction between the virus and another receptor on the olfactory neurons or from its contact with nonnerve cells that line the nose .
Experts say the virus need not make it inside neurons to cause some @ @ @ @ @ @ @ from the disease .
Many pain-related effects could arise from an attack on sensory neurons , the nerves that extend from the spinal cord throughout the body to gather information from the external environment or internal bodily processes .
Researchers are now making headway in understanding how SARS-CoV-2 could hijack pain-sensing neurons , called nociceptors , to produce some of COVID-19 ’ s hallmark symptoms .
Neuroscientist Theodore Price , who studies pain at the University of Texas at Dallas , took note of the symptoms reported in the early literature and cited @ @ @ @ @ @ @ nurse practitioner who sees people with COVID remotely .
Those symptoms include sore throat , headaches , body-wide muscle pain and severe cough .
( The cough is triggered in part by sensory nerve cells in the lungs . )
Curiously , some patients report a loss of a particular sensation called chemethesis , which leaves them unable to detect hot chilies or cool peppermints—perceptions conveyed by nociceptors , not taste cells .
While many of these effects are typical of viral infections , the prevalence and persistence of these pain-related symptoms—and their @ @ @ @ @ @ @ that sensory neurons might be affected beyond normal inflammatory responses to infection .
That means the effects may be directly tied to the virus itself .
“ It ’ s just striking , ” Price says .
The affected patients “ all have headaches , and some of them seem to have pain problems that sound like neuropathies , ” chronic pain that arises from nerve damage .
That observation led him to investigate whether the novel coronavirus could infect nociceptors .
The main criteria scientists use to determine whether SARS-CoV-2 can infect @ @ @ @ @ @ @ of angiotensin-converting enzyme 2 ( ACE2 ) , a protein embedded in the surface of cells .
ACE2 acts as a receptor that sends signals into the cell to regulate blood pressure and is also an entry point for SARS-CoV-2 .
So Price went looking for it in human neurons in a study now published in the journal PAIN .
Nociceptors—and other sensory neurons—live in discreet clusters , found just outside the spinal cord , called dorsal root ganglia ( DRG ) .
Price and his team procured nerve cells donated after death @ @ @ @ @ @ @ RNA sequencing , a technique to determine which proteins a cell is about to produce , and they used antibodies to target ACE2 itself .
They found that a subset of DRG neurons did contain ACE2 , providing the virus a portal into the cells .
Sensory neurons send out long tendrils called axons , whose endings sense specific stimuli in the body and then transmit them to the brain in the form of electrochemical signals .
The particular DRG neurons that contained ACE2 also had the genetic instructions , the mRNA , @ @ @ @ @ @ @ That protein marks the cells as a subset of neurons whose endings are concentrated at the body ’ s surfaces—the skin and inner organs , including the lungs—where they would be poised to pick up the virus .
Price says nerve infection could contribute to acute , as well as lasting , symptoms of COVID .
“ The most likely scenario would be that the autonomic and sensory nerves are affected by the virus , ” he says .
“ We know that if sensory neurons get infected with a virus , it @ @ @ @ @ @ @ if the virus does not stay in cells .
But , Price adds , “ it does not need to be that the neurons get infected.
” In another recent study , he compared genetic sequencing data from lung cells of COVID patients and healthy controls and looked for interactions with healthy human DRG neurons .
Price says his team found a lot of immune-system-signaling molecules called cytokines from the infected patients that could interact with receptors on neurons .
“ It ’ s basically a bunch of stuff we know is involved @ @ @ @ @ @ @ that nerves could be undergoing lasting damage from the immune molecules without being directly infected by the virus .
Anne Louise Oaklander , a neurologist at Massachusetts General Hospital , who wrote a commentary accompanying Price ’ s paper in PAIN , says that the study “ was exceptionally good , ” in part because it used human cells .
But , she adds , “ we don ’ t have evidence that direct entry of the virus into [ nerve ] cells is the major mechanism of cellular [ nerve ] damage @ @ @ @ @ @ @ not discount that possibility .
It is “ absolutely possible ” that inflammatory conditions outside nerve cells could alter their activity or even cause permanent damage , Oaklander says .
Another prospect is that viral particles interacting with neurons could lead to an autoimmune attack on nerves .
ACE2 is widely thought to be the novel coronavirus ’ s primary entry point .
But Rajesh Khanna , a neuroscientist and pain researcher at the University of Arizona , observes that “ ACE2 is not the only game in town for SARS-CoV-2 to come @ @ @ @ @ @ @ neuropilin-1 ( NRP1 ) , “ could be an alternate doorway ” for viral entry , he adds .
NRP1 plays an important role in angiogenesis ( the formation of new blood vessels ) and in growing neurons ’ long axons .
That idea came from studies in cells and in mice ( initially reported in preprint papers that were not peer-reviewed ) .
It was found that NRP1 interacts with the virus ’ s infamous spike protein , which it uses to gain entry into cells .
“ We proved that it @ @ @ @ @ @ @ infectious potential , ” says virologist Giuseppe Balistreri of the University of Helsinki , who co-authored the mouse study , which was published in Science .
It appears more likely that NRP1 acts as a co-factor with ACE2 than that the protein alone affords the virus entry to cells .
“ What we know is that when we have the two receptors , we get more infection .
Together , it ’ s much more powerful , ” Balistreri adds .
Those findings piqued the interest of Khanna , who was studying vascular @ @ @ @ @ @ @ a molecule with a long-recognized role in pain signaling that also binds to NRP1 .
He wondered whether the virus would affect pain signaling through NRP1 , so he tested it in rats in a study that was also published in PAIN .
“ We put VEGF in the animal [ in the paw ] , and lo and behold , we saw robust pain over the course of 24 hours , ” Khanna says .
“ Then came the really cool experiment : We put in VEGF and spike at the same @ @ @ @ @ @ @ pain is gone.
” The study showed “ what happens to the neuron ’ s signaling when the virus tickles the NRP1 receptor , ” Balistreri says .
“ The results are strong , ” demonstrating that neurons ’ activity was altered “ by the touch of the spike of the virus through NRP1.
” In an experiment in rats with a nerve injury to model chronic pain , administering the spike protein alone attenuated the animals ’ pain behaviors .
That finding hints that a spike-like drug that binds NRP1 might have @ @ @ @ @ @ @ Such molecules are already in development for use in cancer .
In a more provocative and untested hypothesis , Khanna speculates that the spike protein might act at NRP1 to silence nociceptors in people , perhaps masking pain-related symptoms very early in an infection .
The idea is that the protein could provide an anesthetic effect as SARS-CoV-2 begins to infect a person , which might allow the virus to spread more easily .
“ I can not exclude it , ” says Balistreri .
“ It ’ s not impossible .
Viruses @ @ @ @ @ @ @ unseen .
This is the best thing they know : to silence our defenses.
” It still remains to be determined whether a SARS-CoV-2 infection could produce analgesia in people .
“ They used a high dose of a piece of the virus in a lab system and a rat , not a human , ” Balistreri says .
“ The magnitude of the effects they ’ re seeing [ may be due to ] the large amount of viral protein they used .
The question will be to see if the virus @ @ @ @ @ @ @ people.
” The experience of one patient—Rave Pretorius , a 49-year-old South African man—suggests that continuing this line of research is probably worthwhile .
A motor accident in 2011 left Pretorius with several fractured vertebrae in his neck and extensive nerve damage .
He says he lives with constant burning pain in his legs that wakes him up nightly at 3 or 4 A.M. “ It feels like somebody is continuously pouring hot water over my legs , ” Pretorius says .
But that changed dramatically when he contracted COVID-19 in July at @ @ @ @ @ @ @ “ I found it very strange : When I was sick with COVID , the pain was bearable .
At some points , it felt like the pain was gone .
I just couldn ’ t believe it , ” he says .
Pretorius was able to sleep through the night for the first time since his accident .
“ I lived a better life when I was sick because the pain was gone , ” despite having fatigue and debilitating headaches , he says .
Now that Pretorius has recovered from COVID @ @ @ @ @ @ @ For better or worse , COVID-19 seems to have effects on the nervous system .
Whether they include infection of nerves is still unknown like so much about SARS-CoV-2 .
The bottom line is that while the virus apparently can , in principle , infect some neurons , it doesn ’ t need to .
It can cause plenty of havoc from the outside these cells .
Read more about the coronavirus outbreak from Scientific American here .
And read coverage from our international network of magazines here .

Many of the symptoms experienced by people infected with SARS-CoV-2 involve the nervous system. Patients complain of headaches, muscle and joint pain, fatigue and “brain fog,” or loss of taste and smell—all of which can last from weeks to months after infection. In severe cases, COVID-19 can also lead to encephalitis or stroke. The virus has undeniable neurological effects. But the way it actually affects nerve cells still remains a bit of a mystery. Can immune system activation alone produce symptoms? Or does the novel coronavirus directly attack the nervous system?
Some studies—including a recent preprint paper examining mouse and human brain tissue—show evidence that SARS-CoV-2 can get into nerve cells and the brain. The question remains as to whether it does so routinely or only in the most severe cases. Once the immune system kicks into overdrive, the effects can be far-ranging, even leading immune cells to invade the brain, where they can wreak havoc.
Some neurological symptoms are far less serious yet seem, if anything, more perplexing. One symptom—or set of symptoms—that illustrates this puzzle and has gained increasing attention is an imprecise diagnosis called “brain fog.” Even after their main symptoms have abated, it is not uncommon for COVID-19 patients to experience memory loss, confusion and other mental fuzziness. What underlies these experiences is still unclear, although they may also stem from the body-wide inflammation that can go along with COVID-19. Many people, however, develop fatigue and brain fog that lasts for months even after a mild case that does not spur the immune system to rage out of control.
Another widespread symptom called anosmia, or loss of smell, might also originate from changes that happen without nerves themselves getting infected. Olfactory neurons, the cells that transmit odors to the brain, lack the primary docking site, or receptor, for SARS-CoV-2, and they do not seem to get infected. Researchers are still investigating how loss of smell might result from an interaction between the virus and another receptor on the olfactory neurons or from its contact with nonnerve cells that line the nose.
Experts say the virus need not make it inside neurons to cause some of the mysterious neurological symptoms now emerging from the disease. Many pain-related effects could arise from an attack on sensory neurons, the nerves that extend from the spinal cord throughout the body to gather information from the external environment or internal bodily processes. Researchers are now making headway in understanding how SARS-CoV-2 could hijack pain-sensing neurons, called nociceptors, to produce some of COVID-19’s hallmark symptoms.
Neuroscientist Theodore Price, who studies pain at the University of Texas at Dallas, took note of the symptoms reported in the early literature and cited by patients of his wife, a nurse practitioner who sees people with COVID remotely. Those symptoms include sore throat, headaches, body-wide muscle pain and severe cough. (The cough is triggered in part by sensory nerve cells in the lungs.)
Curiously, some patients report a loss of a particular sensation called chemethesis, which leaves them unable to detect hot chilies or cool peppermints—perceptions conveyed by nociceptors, not taste cells. While many of these effects are typical of viral infections, the prevalence and persistence of these pain-related symptoms—and their presence in even mild cases of COVID-19—suggest that sensory neurons might be affected beyond normal inflammatory responses to infection. That means the effects may be directly tied to the virus itself. “It’s just striking,” Price says. The affected patients “all have headaches, and some of them seem to have pain problems that sound like neuropathies,” chronic pain that arises from nerve damage. That observation led him to investigate whether the novel coronavirus could infect nociceptors.
The main criteria scientists use to determine whether SARS-CoV-2 can infect cells throughout the body is the presence of angiotensin-converting enzyme 2 (ACE2), a protein embedded in the surface of cells. ACE2 acts as a receptor that sends signals into the cell to regulate blood pressure and is also an entry point for SARS-CoV-2. So Price went looking for it in human neurons in a study now published in the journal PAIN.
Nociceptors—and other sensory neurons—live in discreet clusters, found just outside the spinal cord, called dorsal root ganglia (DRG). Price and his team procured nerve cells donated after death or cancer surgeries. The researchers performed RNA sequencing, a technique to determine which proteins a cell is about to produce, and they used antibodies to target ACE2 itself. They found that a subset of DRG neurons did contain ACE2, providing the virus a portal into the cells.
Sensory neurons send out long tendrils called axons, whose endings sense specific stimuli in the body and then transmit them to the brain in the form of electrochemical signals. The particular DRG neurons that contained ACE2 also had the genetic instructions, the mRNA, for a sensory protein called MRGPRD. That protein marks the cells as a subset of neurons whose endings are concentrated at the body’s surfaces—the skin and inner organs, including the lungs—where they would be poised to pick up the virus.
Price says nerve infection could contribute to acute, as well as lasting, symptoms of COVID. “The most likely scenario would be that the autonomic and sensory nerves are affected by the virus,” he says. “We know that if sensory neurons get infected with a virus, it can have long-term consequences,” even if the virus does not stay in cells.
But, Price adds, “it does not need to be that the neurons get infected.” In another recent study, he compared genetic sequencing data from lung cells of COVID patients and healthy controls and looked for interactions with healthy human DRG neurons. Price says his team found a lot of immune-system-signaling molecules called cytokines from the infected patients that could interact with receptors on neurons. “It’s basically a bunch of stuff we know is involved in neuropathic pain.” That observation suggests that nerves could be undergoing lasting damage from the immune molecules without being directly infected by the virus.
Anne Louise Oaklander, a neurologist at Massachusetts General Hospital, who wrote a commentary accompanying Price’s paper in PAIN, says that the study “was exceptionally good,” in part because it used human cells. But, she adds, “we don’t have evidence that direct entry of the virus into [nerve] cells is the major mechanism of cellular [nerve] damage,” though the new findings do not discount that possibility. It is “absolutely possible” that inflammatory conditions outside nerve cells could alter their activity or even cause permanent damage, Oaklander says. Another prospect is that viral particles interacting with neurons could lead to an autoimmune attack on nerves.
ACE2 is widely thought to be the novel coronavirus’s primary entry point. But Rajesh Khanna, a neuroscientist and pain researcher at the University of Arizona, observes that “ACE2 is not the only game in town for SARS-CoV-2 to come into cells.” Another protein, called neuropilin-1 (NRP1), “could be an alternate doorway” for viral entry, he adds. NRP1 plays an important role in angiogenesis (the formation of new blood vessels) and in growing neurons’ long axons.
That idea came from studies in cells and in mice. It was found that NRP1 interacts with the virus’s infamous spike protein, which it uses to gain entry into cells. “We proved that it binds neuropilin and that the receptor has infectious potential,” says virologist Giuseppe Balistreri of the University of Helsinki, who co-authored the mouse study, which was published in Science along with a separate study in cells. It appears more likely that NRP1 acts as a co-factor with ACE2 than that the protein alone affords the virus entry to cells. “What we know is that when we have the two receptors, we get more infection. Together, it’s much more powerful,” Balistreri adds.
Those findings piqued the interest of Khanna, who was studying vascular endothelial growth factor (VEGF), a molecule with a long-recognized role in pain signaling that also binds to NRP1. He wondered whether the virus would affect pain signaling through NRP1, so he tested it in rats in a study that was also published in PAIN. “We put VEGF in the animal [in the paw], and lo and behold, we saw robust pain over the course of 24 hours,” Khanna says. “Then came the really cool experiment: We put in VEGF and spike at the same time, and guess what? The pain is gone.”
The study showed “what happens to the neuron’s signaling when the virus tickles the NRP1 receptor,” Balistreri says. “The results are strong,” demonstrating that neurons’ activity was altered “by the touch of the spike of the virus through NRP1.”
In an experiment in rats with a nerve injury to model chronic pain, administering the spike protein alone attenuated the animals’ pain behaviors. That finding hints that a spike-like drug that binds NRP1 might have potential as a new pain reliever. Such molecules are already in development for use in cancer.
In a more provocative and untested hypothesis, Khanna speculates that the spike protein might act at NRP1 to silence nociceptors in people, perhaps masking pain-related symptoms very early in an infection. The idea is that the protein could provide an anesthetic effect as SARS-CoV-2 begins to infect a person, which might allow the virus to spread more easily. “I cannot exclude it,” says Balistreri. “It’s not impossible. Viruses have an arsenal of tools to go unseen. This is the best thing they know: to silence our defenses.”
It still remains to be determined whether a SARS-CoV-2 infection could produce analgesia in people. “They used a high dose of a piece of the virus in a lab system and a rat, not a human,” Balistreri says. “The magnitude of the effects they’re seeing [may be due to] the large amount of viral protein they used. The question will be to see if the virus itself can [blunt pain] in people.”
The experience of one patient—Rave Pretorius, a 49-year-old South African man—suggests that continuing this line of research is probably worthwhile. A motor accident in 2011 left Pretorius with several fractured vertebrae in his neck and extensive nerve damage. He says he lives with constant burning pain in his legs that wakes him up nightly at 3 or 4 A.M. “It feels like somebody is continuously pouring hot water over my legs,” Pretorius says. But that changed dramatically when he contracted COVID-19 in July at his job at a manufacturing company. “I found it very strange: When I was sick with COVID, the pain was bearable. At some points, it felt like the pain was gone. I just couldn’t believe it,” he says. Pretorius was able to sleep through the night for the first time since his accident. “I lived a better life when I was sick because the pain was gone,” despite having fatigue and debilitating headaches, he says. Now that Pretorius has recovered from COVID, his neuropathic pain has returned.
For better or worse, COVID-19 seems to have effects on the nervous system. Whether they include infection of nerves is still unknown like so much about SARS-CoV-2. The bottom line is that while the virus apparently can, in principle, infect some neurons, it doesn’t need to. It can cause plenty of havoc from the outside these cells.
Read more about the coronavirus outbreak from Scientific American here. And read coverage from our international network of magazines here.


scientificamerican--2020-10-22--A Sustainable Alternative to Blanket Lockdowns

As cities around the world—including Auckland , Jakarta , Melbourne and Tel Aviv—have entered seemingly endless cycles of lockdowns and viral resurgences , there is a pressing need to reassess this lockdown strategy given the economic , social and psychological damage it wreaks .
Blanket lockdowns may be effective , but they are blunt and brutal tools .
As this pandemic wears on , possibly for months or even years to come , we need a sustainable alternative that involves more targeted measures that are evidence-based and data-driven .
This pandemic has repeatedly proven that amid crisis comes opportunity .
@ @ @ @ @ @ @ in an intensely digitalizing and hyperconnected world , COVID-19 and its spread can be dissected using the big data that grow more voluminous by the day .
Such data , aggregated from multiple sources , are game-changing in helping us identify “ superspreader locales , ” so that instead of locking down entire cities , we can take the more sustainable approach of shutting down or reconfiguring specific locations with high potential to trigger outbreaks .
Principally , certain locations , like people , can be spatial superspreaders , and big data are @ @ @ @ @ @ @ .
Because cities constantly hum with activity , where people transit , meet , mingle and disperse , they are centers of convergence for human interaction and disease propagation .
Mapping the interplay between patterns of human mobility in and through cities with the contours of human co-presence activity is thus critical for managing all disease outbreaks , big or small .
Encouragingly , we have various illuminating sources of human mobility data at our disposal to identify vulnerable locations beset by the dangerous confluence of high human traffic , intense social interaction @ @ @ @ @ @ @ spread .
These include urban analytics data capturing ground transportation trips .
In cities such as Hong Kong , Paris and Singapore , such transportation data are systematically analyzed for improved urban and mobility planning .
Newer data streams from ride-sharing services , Internet of Things–connected devices including smart lampposts and smartphones running traffic apps , and social media posts with geolocation data , can also help to map where human mobility patterns , human co-presence activity and epidemic spread intersect .
Such valuable data on human activity can then be processed on @ @ @ @ @ @ @ evidence of COVID-19 spread .
Although this disease has been marked by numerous confounding factors , some facts are now well-established , such as that brief encounters outdoors are less risky than extensive interactions in closed quarters .
Furthermore , there is now a wide expert consensus about the effectiveness of pervasive mask-wearing and social distancing measures .
Nonetheless , our fragmentary understanding of the interplay between COVID-19 transmissions and human social interaction in various settings is the principal challenge to developing a detailed map of all infection pathways across a range of @ @ @ @ @ @ @ targeted containment strategies in urban settings , it is imperative to advance our knowledge about this complex interplay .
New evidence is being rapidly gathered , thereby creating a useful knowledge base for local governments and health departments to adapt , refine and sharpen their prevention and containment strategies .
By integrating epidemiological findings with data on human mobility and physical interaction , superspreader locales can be effectively identified and contained , while vulnerable populations can be better supported and managed .
With safe and effective vaccines still far on horizon , we @ @ @ @ @ @ @ possess to tackle this disease , and big data constitute potent ammunition .
Healthier funding is imperative for boosting research on the nature of human movement and social interactions spanning the spectrum of typical urban locations .
Cities must therefore commit resources for collecting such human mobility data and to establish legal and technical structures for such data to be shared in the interest of societally beneficial research .
Our battle with COVID-19 has necessitated the deployment of varied strategies , some of which have proven more effective than others .
As we @ @ @ @ @ @ @ containment tactics and their trade-offs , blanket lockdowns seem to have yielded mixed results .
Rather , distilling and blending insights from big data and epidemiology to anticipate superspreading locales can help governments avoid imposing brutal , wholesale lockdowns .
Granular , targeted and focused containment measures that are empirically based and supercharged by big data are a viable alternative .
With such an approach , solutions for tackling COVID-19 need not appear arbitrary , grounded in conjecture or requiring a leap of faith .
This essay is based on an article that @ @ @ @ @ @ @ 2020 .

As cities around the world—including Auckland, Jakarta, Melbourne and Tel Aviv—have entered seemingly endless cycles of lockdowns and viral resurgences, there is a pressing need to reassess this lockdown strategy given the economic, social and psychological damage it wreaks. Blanket lockdowns may be effective, but they are blunt and brutal tools. As this pandemic wears on, possibly for months or even years to come, we need a sustainable alternative that involves more targeted measures that are evidence-based and data-driven.
This pandemic has repeatedly proven that amid crisis comes opportunity. Being the first pandemic to break out in an intensely digitalizing and hyperconnected world, COVID-19 and its spread can be dissected using the big data that grow more voluminous by the day. Such data, aggregated from multiple sources, are game-changing in helping us identify “superspreader locales,” so that instead of locking down entire cities, we can take the more sustainable approach of shutting down or reconfiguring specific locations with high potential to trigger outbreaks.
Principally, certain locations, like people, can be spatial superspreaders, and big data are vital for identifying these weak spatial links. Because cities constantly hum with activity, where people transit, meet, mingle and disperse, they are centers of convergence for human interaction and disease propagation. Mapping the interplay between patterns of human mobility in and through cities with the contours of human co-presence activity is thus critical for managing all disease outbreaks, big or small.
Encouragingly, we have various illuminating sources of human mobility data at our disposal to identify vulnerable locations beset by the dangerous confluence of high human traffic, intense social interaction, and epidemiological conditions favorable to disease spread. These include urban analytics data capturing ground transportation trips. In cities such as Hong Kong, Paris and Singapore, such transportation data are systematically analyzed for improved urban and mobility planning. Newer data streams from ride-sharing services, Internet of Things–connected devices including smart lampposts and smartphones running traffic apps, and social media posts with geolocation data, can also help to map where human mobility patterns, human co-presence activity and epidemic spread intersect.
Such valuable data on human activity can then be processed on the basis of the latest available epidemiological evidence of COVID-19 spread. Although this disease has been marked by numerous confounding factors, some facts are now well-established, such as that brief encounters outdoors are less risky than extensive interactions in closed quarters. Furthermore, there is now a wide expert consensus about the effectiveness of pervasive mask-wearing and social distancing measures.
Nonetheless, our fragmentary understanding of the interplay between COVID-19 transmissions and human social interaction in various settings is the principal challenge to developing a detailed map of all infection pathways across a range of social groups and activities. To devise targeted containment strategies in urban settings, it is imperative to advance our knowledge about this complex interplay.
New evidence is being rapidly gathered, thereby creating a useful knowledge base for local governments and health departments to adapt, refine and sharpen their prevention and containment strategies. By integrating epidemiological findings with data on human mobility and physical interaction, superspreader locales can be effectively identified and contained, while vulnerable populations can be better supported and managed.
With safe and effective vaccines still far on horizon, we need to marshal the resources we currently possess to tackle this disease, and big data constitute potent ammunition. Healthier funding is imperative for boosting research on the nature of human movement and social interactions spanning the spectrum of typical urban locations. Cities must therefore commit resources for collecting such human mobility data and to establish legal and technical structures for such data to be shared in the interest of societally beneficial research.
Our battle with COVID-19 has necessitated the deployment of varied strategies, some of which have proven more effective than others. As we take a hard look at the different containment tactics and their trade-offs, blanket lockdowns seem to have yielded mixed results. Rather, distilling and blending insights from big data and epidemiology to anticipate superspreading locales can help governments avoid imposing brutal, wholesale lockdowns. Granular, targeted and focused containment measures that are empirically based and supercharged by big data are a viable alternative. With such an approach, solutions for tackling COVID-19 need not appear arbitrary, grounded in conjecture or requiring a leap of faith.
This essay is based on an article that appeared in Nature on July 10, 2020.


scientificamerican--2020-10-22--Can a Moon Base be Safe for Astronauts?

Can a Moon Base be Safe for Astronauts?

On August 4 , 1972 , the sun unleashed an incandescent whip of energy from its surface and flung it toward the planets .
It was accompanied by a seething cloud of plasma called a coronal mass ejection , which traversed the nearly 150 million kilometers between sun and Earth in just more than half a day—still the fastest-known arrival time for such outbursts—to briefly bathe our planet in cosmic fire .
Earth ’ s shielding magnetosphere crumpled and shrunk by two thirds , sending powerful geomagnetic currents rippling through the planet .
Dazzling displays of “ northern lights ” @ @ @ @ @ @ @ power lines strained as far south as Texas .
Off the southern coast of Haiphong , North Vietnam , the seas churned as the celestial disturbance prematurely detonated some two dozen U.S. Navy sea mines .
The geomagnetic storm is one of the most violent solar events in recorded history , certainly the most violent of the space age .
The astronauts of Apollo 16 had been home about three months from their lunar foray , and those of Apollo 17 were still preparing for their December launch .
The fact that the @ @ @ @ @ @ @ final crewed moon missions was simply a matter of chance .
If the members of either crew had been in space during the solar storm , especially if they had been traversing the portion of the “ cislunar ” region between Earth and the moon that lies outside the magnetosphere , they would have been exposed to a potentially deadly dose of radiation .
We got lucky in 1972 .
And in terms of space-based hazards , that luck has largely held throughout humanity ’ s off-world excursions .
To date , the @ @ @ @ @ @ @ were the three cosmonauts of Soyuz 11 , who asphyxiated because of faulty hardware as their spacecraft began its descent to Earth .
Yet despite what most estimates would seem to consider a near-sterling safety record , today the prospect of venturing back beyond low-Earth orbit somehow seems more daunting—more dangerous—than it did when the Apollo program ended .
Equipped with more knowledge than ever about the environs beyond our home , we now seem more reluctant to leave it .
Maybe we know too much .
Politics , money and uneven federal @ @ @ @ @ @ @ since Richard Nixon has sent humans back to the moon .
Some lunar exploration advocates also sense more philosophical reasons , however .
We understand , better than at any point in the space age , what can happen to us out there .
Is making the journey worth it ?
We watch our own planet burn , and we witness almost unimaginable beauty recorded by the sensors of our solar-system-touring robots , and we wonder whether human lives should be on the line in the name of exploring beyond Earth .
Space @ @ @ @ @ @ @ to venture past our world ’ s upper atmosphere will die painfully without a life-support system .
Even with adequate life support , the sun could still kill spacefarers if it lets loose at just the wrong instant while they are beyond the magnetosphere ’ s protective bubble .
Deep space could kill us , too— even from afar : particles and radiation emanating from exploding stars and active galaxies become , when they arrive in our vicinity , harmful cosmic rays that can rend DNA at the seams to spark cancer and @ @ @ @ @ @ @ latter threat is only now becoming clear .
On September 25 an international team of scientists working with China ’ s Chang ’ e 4 lander and Yutu 2 rover announced the moon is constantly bombarded by showers of dangerous cosmic rays .
“ A New Problem for Astronauts , ” read part of a headline at the Web site ExtremeTech .
“ Radiation Levels on the Moon Are Alarmingly High , ” said a site called Interesting Engineering .
“ New Measurements Show Moon Has Hazardous Radiation Levels , ” the Associated @ @ @ @ @ @ @ lunar scientist and space-exploration advocate at the University of Notre Dame , has hoped to see more people on the moon since the Apollo 17 astronauts departed 48 years ago .
Making that happen , he suspects , might require acknowledging that failure is not only an option—it is inevitable .
“ As we ’ ve seen in testing rockets , failure is where you learn a lot , ” he says .
“ Despite everything you do , you ’ re not going to get rid of all the risks .
That @ @ @ @ @ @ @ , Americans strapped to an American rocket launched from American soil for the first time in nearly a decade .
Could a return to the moon be far off ?
Under the Trump administration ’ s Artemis plan , NASA is angling to send the first woman and the next man to the moon ’ s resource-rich south pole by 2024 .
It is a long shot : The space agency and the contractors it relies on for much of its flight hardware must hasten to finish the arduous task of building massive @ @ @ @ @ @ @ believe Congress has to dramatically increase funding for this to be possible , to say nothing of the uncertainty that would stem from a November 3 victory by Democrats Joe Biden and Kamala Harris in the U.S. presidential election .
NASA administrator Jim Bridenstine says he is optimistic , however .
And a growing community of lunar scientists and private companies are operating as though Artemis will happen , even as the true scopes of the myriad challenges the project faces becomes clear .
“ Everyone has wanted to make progress in their @ @ @ @ @ @ @ Now that there seems to be a real solid direction and a goal , everybody is motivated and working together , ” says Dana Hurley , a space physicist at the Johns Hopkins University Applied Physics Laboratory ( APL ) .
People are working together to allow humans to live and work “ off-planet , ” as Neal likes to put it .
Protecting them from radiation has to be a primary goal .
But just how that would work , and what level of protection is actually necessary , will be a @ @ @ @ @ @ @ .
“ Anybody who is on the NASA side of the aisle is going to say , ‘ First and foremost , we have to preserve the safety of the people engaged , the astronauts , and everything else is secondary.
’ And it should be , ” says Roger Launius , a longtime NASA historian .
“ Nobody disagrees with that .
The question is ‘ What is necessary to ensure that safety ?
’ That ’ s always a hard thing.
” Astronauts on the surface of the moon would face @ @ @ @ @ @ @ than we experience on Earth , says Robert F. Wimmer-Schweingruber of Kiel University in Germany , who co-led the new Chang ’ e 4 study .
That is about two and a half times the radiation level on the International Space Station ( ISS ) .
Earth ’ s thick atmosphere and powerful magnetic field protect us .
The moon is airless , however , and its magnetic field is extremely weak , so it has no shielding .
The cosmic rays are mostly in the form of neutrons , which are large @ @ @ @ @ @ @ particles go ) .
And they can produce secondary particles that do their own damage , much like a cue ball scattering racked billiard balls .
Ironically , the sun protects from this a bit , says George Ho , a heliophysicist at APL .
When our star is undergoing the active phase of its 11-year cycle , it unleashes more radiation , like it did in that nasty 1972 storm .
These harmful emanations can , to some degree , safeguard Earth and the other planets by deflecting a portion of the @ @ @ @ @ @ @ performed by the Chang ’ e 4 mission occurred during an extraordinarily quiescent solar phase , Ho adds .
“ We ’ ve done so much better since the Apollo days .
We look at the sun continuously now , ” Ho says .
“ We can forecast and say , ‘ Hey , the next seven days will be bad for people doing EVAs [ extravehicular activities ] .
’ And for solar particle events , a few millimeters of aluminum can shield from those.
” Because they can penetrate such thin @ @ @ @ @ @ @ dangerous than run-of-the-mill solar particles .
Radiation-blocking material such as lead offers little help because it still produces secondary particles that are also dangerous .
Many scientists expect that visitors to the moon , especially the first few crews , will stay for only a few days or , at most , a couple of weeks .
The cumulative radiation dose for such short stays would be manageable .
Longer-term outposts , such as moon bases and lunar-orbiting space stations envisaged by multiple space programs , will need a plan , however .
@ @ @ @ @ @ @ yet advocates such as Neal say they will only come to fruition if countries work together , not in competition .
The most obvious solution to high levels of radiation at the lunar surface is to avoid dwelling there .
Wimmer-Schweingruber says underground habitats could protect moon dwellers from many harmful particles .
Lunar visitors should plan to build habitats at least 80 centimeters ( about two and a half feet ) beneath the surface , he says .
To do so , they will want to bring bulldozers—or at least beefy rovers @ @ @ @ @ @ @ , a physicist at the Planetary Science Institute , imagines people living inside lava tubes , which are hollow deposits left behind by ancient magma flows .
“ It ’ s kind of a double whammy , because it ’ s not only going to protect you from radiation but also protect you from micrometeoroid impacts , ” she says .
Sungwoo Lim , a physicist at the Open University , based in England , has published research describing how to use microwaves to sinter lunar regolith .
This work raises the distinct @ @ @ @ @ @ @ building material the ancient Sumerian way : by baking dirt into bricks .
At the Massachusetts Institute of Technology , aeronautics researcher Dava Newman and her graduate student Cody Paige are working on future space suits built from new advanced materials .
Polyethylene—basic plastic—turns out to be a great radiation shield because it is so full of hydrogen , which absorbs the heavy neutrons in cosmic rays , Paige says .
Future space suits could further boost their protective capacity by also incorporating aerogels , carbon nanotubes , boron nanotubes and boron shielding @ @ @ @ @ @ @ helpful : because of how neutrons are arrayed inside its atomic nuclei , the substance ’ s cosmic-ray-stopping power is some four orders of magnitude greater than that of hydrogen .
Future space suits have to be lightweight , easy to move in , and better at protecting astronauts from hazards such as micrometeorites and radiation , Newman says .
The current basic space suit weighs about 300 pounds ( 136 kilograms ) , and she wants to bring that down to 90 pounds ( 41 kilograms ) .
“ You ’ re @ @ @ @ @ @ @ you ’ re in a gas-pressurized , bulky shell , ” Newman says .
The next space suit might look and fit more like a wet suit .
Astronauts could don multiple layers like a spring skier and don a radiation-shielding overcoat when the conditions call for it .
Space suits could also add shielding where it is most necessary , covering essential organs but leaving the extremities more exposed .
Astronauts will face three main sources of danger on the moon : radiation , reduced gravity and regolith .
Radiation is the @ @ @ @ @ @ @ is a well-known health hazard , too .
Even when offset by rigorous exercise , astronauts still lose muscle mass and bone density during extended stays in the microgravity environs of the ISS .
The moon ’ s gravity is heftier—about one sixth of Earth ’ s—but long-duration visitors will still experience some of low gravity ’ s deleterious effects .
Se-Jin Lee , a geneticist at the University of Connecticut , is trying to address some of those problems .
After more than 10 years of efforts , he was able to @ @ @ @ @ @ @ ISS last December .
Some of the animals were modified to lack a gene that suppresses muscle growth , some were treated with an experimental drug that works in a similar fashion , and others served as unmodified controls .
The modified and treated mice not only maintained their muscle mass in space but even bulked up and had better bone density , compared with the untreated ones , Lee found .
Although a drug based on this research remains far off for humans , the work suggests that astronauts might someday be @ @ @ @ @ @ @ the worst health effects of reduced gravity .
The gene that suppresses muscle growth produces a protein called myostatin , which usually works to balance muscle mass with fat .
A molecule that keeps the two in equilibrium would benefit animals trying to maintain enough muscle to hunt or run away while also preventing them from accumulating it in excess , which is more costly to maintain .
“ For humans , I think this is an evolutionary vestige , ” Lee says of the molecule .
“ We don ’ t really @ @ @ @ @ @ @ We all have refrigerators ; we live in homes with electricity ; we don ’ t have to escape from predators .
That ’ s why I argue that this particular system is so attractive for drugs.
” Even if astronauts can avoid radiation exposure and muscle degeneration , the moon ’ s surficial soil—called regolith—itself poses another tricky problem .
Composed of jagged , microscopic shards of rock , moon dust is like a more abrasive and irritating talcum powder : it gets into everything , from astronaut lungs to tiny machine @ @ @ @ @ @ @ flies around when a spacecraft lands or launches , turning landing zones into a buckshot-blasted scouring pad , Watkins notes .
“ The bigger concern becomes when you start to land multiple spacecraft in the same area .
You really have to worry about how far away you land because of that dust , ” she says .
“ Imagine it flying at one kilometer per second .
It ’ s going to do some damage , so figuring out ways to mitigate that is a big area of concern right now.
” @ @ @ @ @ @ @ Stronger Like many enthusiastic lunar scientists , M.I.T.
’ s Newman notes that the next wave of space exploration is a form of soft diplomacy .
“ This is about the potential of the world working together , ” she says .
Launius , like many others , views the moon as akin to Antarctica , which contains multiple international scientific stations .
It is difficult and dangerous to access , but people do it all the time , cycling in and out in small crews .
“ We can do camping trips @ @ @ @ @ @ @ .
“ We can go up and spend a few days ; take everything you need with you .
There ’ s not any reason to think we don ’ t have the capability to put a lunar base up and stay there for some period of time .
But here ’ s the problem : Fundamentally , going into space with humans is about becoming a multiplanetary species .
If that ’ s not the reason , then why are we doing it ?
Once you do that , we ’ re @ @ @ @ @ @ @ station.
” It is hard to talk in practical terms about such grand ideas , Launius says .
And right now , when multiple countries are planning moon bases and space stations , practicality is rearing its head .
Space travel is more possible than ever , and we know more about it than ever , so the danger is more clear and present than it was in the past .
What is more , Launius believes the U.S. is more averse to risk now than it was during the Apollo age .
@ @ @ @ @ @ @ , ” he says .
“ If I ’ m standing on the corner waiting to cross , and I see a car 100 yards [ 91 meters ] away , I may decide I can make that .
But the person next to me may not .
That ’ s an understandable problem , and it ’ s different from person to person .
NASA is cautious because they ’ ve had some really close calls , and they ’ ve had some accidents in which they ’ ve lost astronauts .
@ @ @ @ @ @ @ little more risk-averse now , as a society.
” The space agency is also a huge ship , powered by taxpayers and steered by politics .
Exploration advocates have seen moon-return programs announced , hyped , planned and then canceled several times since the 1970s .
Decades of uncertainty are one reason some scientists are so eager to work with the private sector—and vice versa .
Watkins serves on a science advisory panel for Amazon founder Jeff Bezos ’ s space exploration company Blue Origin , and she says the company is keen @ @ @ @ @ @ @ to land and which kinds of experimental equipment to bring .
Private corporations , beholden to stockholders or a few owners , might have a different tolerance for risk than a government agency that answers to the many .
While some exploration advocates argue that NASA needs to dream bigger or cut red tape out of the way , many scientists say simply realizing that space can kill us is not the problem .
What does not kill us could make us stronger .
“ It ’ s not that people aren ’ @ @ @ @ @ @ @ to the lunar south pole is big , ” Watkins says of NASA ’ s planned Artemis mission to land humans on the moon .
“ We just have more knowledge , which isn ’ t a bad thing at all .
We know more , and that means we can also prepare better .
”

On August 4, 1972, the sun unleashed an incandescent whip of energy from its surface and flung it toward the planets. It was accompanied by a seething cloud of plasma called a coronal mass ejection, which traversed the nearly 150 million kilometers between sun and Earth in just more than half a day—still the fastest-known arrival time for such outbursts—to briefly bathe our planet in cosmic fire.
Earth’s shielding magnetosphere crumpled and shrunk by two thirds, sending powerful geomagnetic currents rippling through the planet. Dazzling displays of “northern lights” stretched down to Spain, and overloaded power lines strained as far south as Texas. Off the southern coast of Haiphong, North Vietnam, the seas churned as the celestial disturbance prematurely detonated some two dozen U.S. Navy sea mines. The geomagnetic storm is one of the most violent solar events in recorded history, certainly the most violent of the space age.
The astronauts of Apollo 16 had been home about three months from their lunar foray, and those of Apollo 17 were still preparing for their December launch. The fact that the solar outburst happened between the penultimate and final crewed moon missions was simply a matter of chance. If the members of either crew had been in space during the solar storm, especially if they had been traversing the portion of the “cislunar” region between Earth and the moon that lies outside the magnetosphere, they would have been exposed to a potentially deadly dose of radiation.
We got lucky in 1972. And in terms of space-based hazards, that luck has largely held throughout humanity’s off-world excursions. To date, the only humans to actually die in space were the three cosmonauts of Soyuz 11, who asphyxiated because of faulty hardware as their spacecraft began its descent to Earth. Yet despite what most estimates would seem to consider a near-sterling safety record, today the prospect of venturing back beyond low-Earth orbit somehow seems more daunting—more dangerous—than it did when the Apollo program ended. Equipped with more knowledge than ever about the environs beyond our home, we now seem more reluctant to leave it. Maybe we know too much.
Failure Is an Option
Politics, money and uneven federal directives can all explain why no president since Richard Nixon has sent humans back to the moon. Some lunar exploration advocates also sense more philosophical reasons, however. We understand, better than at any point in the space age, what can happen to us out there. Is making the journey worth it? We watch our own planet burn, and we witness almost unimaginable beauty recorded by the sensors of our solar-system-touring robots, and we wonder whether human lives should be on the line in the name of exploring beyond Earth. Space can kill us. Anyone who dares to venture past our world’s upper atmosphere will die painfully without a life-support system. Even with adequate life support, the sun could still kill spacefarers if it lets loose at just the wrong instant while they are beyond the magnetosphere’s protective bubble. Deep space could kill us, too— even from afar: particles and radiation emanating from exploding stars and active galaxies become, when they arrive in our vicinity, harmful cosmic rays that can rend DNA at the seams to spark cancer and other maladies.
The severity of this latter threat is only now becoming clear. On September 25 an international team of scientists working with China’s Chang’e 4 lander and Yutu 2 rover announced the moon is constantly bombarded by showers of dangerous cosmic rays. “A New Problem for Astronauts,” read part of a headline at the Web site ExtremeTech. “Radiation Levels on the Moon Are Alarmingly High,”said a site called Interesting Engineering. “New Measurements Show Moon Has Hazardous Radiation Levels,” the Associated Press wrote.
Clive Neal, a lunar scientist and space-exploration advocate at the University of Notre Dame, has hoped to see more people on the moon since the Apollo 17 astronauts departed 48 years ago. Making that happen, he suspects, might require acknowledging that failure is not only an option—it is inevitable. “As we’ve seen in testing rockets, failure is where you learn a lot,” he says. “Despite everything you do, you’re not going to get rid of all the risks. That is a fact.”
Earlier this year, Americans strapped to an American rocket launched from American soil for the first time in nearly a decade. Could a return to the moon be far off? Under the Trump administration’s Artemis plan, NASA is angling to send the first woman and the next man to the moon’s resource-rich south pole by 2024. It is a long shot: The space agency and the contractors it relies on for much of its flight hardware must hasten to finish the arduous task of building massive new rockets and landers. Most experts believe Congress has to dramatically increase funding for this to be possible, to say nothing of the uncertainty that would stem from a November 3 victory by Democrats Joe Biden and Kamala Harris in the U.S. presidential election. NASA administrator Jim Bridenstine says he is optimistic, however. And a growing community of lunar scientists and private companies are operating as though Artemis will happen, even as the true scopes of the myriad challenges the project faces becomes clear.
“Everyone has wanted to make progress in their individual area for a long time. Now that there seems to be a real solid direction and a goal, everybody is motivated and working together,” says Dana Hurley, a space physicist at the Johns Hopkins University Applied Physics Laboratory (APL).
People are working together to allow humans to live and work “off-planet,” as Neal likes to put it. Protecting them from radiation has to be a primary goal. But just how that would work, and what level of protection is actually necessary, will be a question for space agencies—and the astronauts themselves.
“Anybody who is on the NASA side of the aisle is going to say, ‘First and foremost, we have to preserve the safety of the people engaged, the astronauts, and everything else is secondary.’ And it should be,” says Roger Launius, a longtime NASA historian. “Nobody disagrees with that. The question is ‘What is necessary to ensure that safety?’ That’s always a hard thing.”
The Radioactive Moon
Astronauts on the surface of the moon would face between 200 and 1,000 times more radiation than we experience on Earth, says Robert F. Wimmer-Schweingruber of Kiel University in Germany, who co-led the new Chang’e 4 study. That is about two and a half times the radiation level on the International Space Station (ISS). Earth’s thick atmosphere and powerful magnetic field protect us. The moon is airless, however, and its magnetic field is extremely weak, so it has no shielding. The cosmic rays are mostly in the form of neutrons, which are large and heavy (as far as subatomic particles go). And they can produce secondary particles that do their own damage, much like a cue ball scattering racked billiard balls.
Ironically, the sun protects from this a bit, says George Ho, a heliophysicist at APL. When our star is undergoing the active phase of its 11-year cycle, it unleashes more radiation, like it did in that nasty 1972 storm. These harmful emanations can, to some degree, safeguard Earth and the other planets by deflecting a portion of the incoming cosmic rays. The recent measurements performed by the Chang’e 4 mission occurred during an extraordinarily quiescent solar phase, Ho adds.
“We’ve done so much better since the Apollo days. We look at the sun continuously now,” Ho says. “We can forecast and say, ‘Hey, the next seven days will be bad for people doing EVAs [extravehicular activities].’ And for solar particle events, a few millimeters of aluminum can shield from those.”
Because they can penetrate such thin shielding, galactic cosmic rays are more dangerous than run-of-the-mill solar particles. Radiation-blocking material such as lead offers little help because it still produces secondary particles that are also dangerous.
Many scientists expect that visitors to the moon, especially the first few crews, will stay for only a few days or, at most, a couple of weeks. The cumulative radiation dose for such short stays would be manageable. Longer-term outposts, such as moon bases and lunar-orbiting space stations envisaged by multiple space programs, will need a plan, however. Lunar scientists have plenty of ideas, yet advocates such as Neal say they will only come to fruition if countries work together, not in competition.
Subsurface Shelters and ‘Spring Skier’ Space Suits
The most obvious solution to high levels of radiation at the lunar surface is to avoid dwelling there. Wimmer-Schweingruber says underground habitats could protect moon dwellers from many harmful particles. Lunar visitors should plan to build habitats at least 80 centimeters (about two and a half feet) beneath the surface, he says. To do so, they will want to bring bulldozers—or at least beefy rovers with front-end loading attachments.
Ryan Watkins, a physicist at the Planetary Science Institute, imagines people living inside lava tubes, which are hollow deposits left behind by ancient magma flows. “It’s kind of a double whammy, because it’s not only going to protect you from radiation but also protect you from micrometeoroid impacts,” she says.
Sungwoo Lim, a physicist at the Open University, based in England, has published research describing how to use microwaves to sinter lunar regolith. This work raises the distinct possibility that future moon residents could produce building material the ancient Sumerian way: by baking dirt into bricks.
At the Massachusetts Institute of Technology, aeronautics researcher Dava Newman and her graduate student Cody Paige are working on future space suits built from new advanced materials. Polyethylene—basic plastic—turns out to be a great radiation shield because it is so full of hydrogen, which absorbs the heavy neutrons in cosmic rays, Paige says. Future space suits could further boost their protective capacity by also incorporating aerogels, carbon nanotubes, boron nanotubes and boron shielding, she adds. Boron-10 is especially helpful: because of how neutrons are arrayed inside its atomic nuclei, the substance’s cosmic-ray-stopping power is some four orders of magnitude greater than that of hydrogen.
Future space suits have to be lightweight, easy to move in, and better at protecting astronauts from hazards such as micrometeorites and radiation, Newman says. The current basic space suit weighs about 300 pounds (136 kilograms), and she wants to bring that down to 90 pounds (41 kilograms).
“You’re wasting the majority of your energy if you’re in a gas-pressurized, bulky shell,” Newman says. The next space suit might look and fit more like a wet suit. Astronauts could don multiple layers like a spring skier and don a radiation-shielding overcoat when the conditions call for it. Space suits could also add shielding where it is most necessary, covering essential organs but leaving the extremities more exposed.
Bulked-Up Mice and Buckshot Regolith
Astronauts will face three main sources of danger on the moon: radiation, reduced gravity and regolith. Radiation is the most recent concern, yet reduced gravity is a well-known health hazard, too. Even when offset by rigorous exercise, astronauts still lose muscle mass and bone density during extended stays in the microgravity environs of the ISS. The moon’s gravity is heftier—about one sixth of Earth’s—but long-duration visitors will still experience some of low gravity’s deleterious effects.
Se-Jin Lee, a geneticist at the University of Connecticut, is trying to address some of those problems. After more than 10 years of efforts, he was able to send a team of mice to the ISS last December. Some of the animals were modified to lack a gene that suppresses muscle growth, some were treated with an experimental drug that works in a similar fashion, and others served as unmodified controls. The modified and treated mice not only maintained their muscle mass in space but even bulked up and had better bone density, compared with the untreated ones, Lee found.
Although a drug based on this research remains far off for humans, the work suggests that astronauts might someday be able to take a pill to prevent the worst health effects of reduced gravity.
The gene that suppresses muscle growth produces a protein called myostatin, which usually works to balance muscle mass with fat. A molecule that keeps the two in equilibrium would benefit animals trying to maintain enough muscle to hunt or run away while also preventing them from accumulating it in excess, which is more costly to maintain.
“For humans, I think this is an evolutionary vestige,” Lee says of the molecule. “We don’t really need to deal with this anymore. We all have refrigerators; we live in homes with electricity; we don’t have to escape from predators. That’s why I argue that this particular system is so attractive for drugs.”
Even if astronauts can avoid radiation exposure and muscle degeneration, the moon’s surficial soil—called regolith—itself poses another tricky problem. Composed of jagged, microscopic shards of rock, moon dust is like a more abrasive and irritating talcum powder: it gets into everything, from astronaut lungs to tiny machine parts and structural crevices. It also flies around when a spacecraft lands or launches, turning landing zones into a buckshot-blasted scouring pad, Watkins notes.
“The bigger concern becomes when you start to land multiple spacecraft in the same area. You really have to worry about how far away you land because of that dust,” she says. “Imagine it flying at one kilometer per second. It’s going to do some damage, so figuring out ways to mitigate that is a big area of concern right now.”
What Does Not Kill You Makes You Stronger
Like many enthusiastic lunar scientists, M.I.T.’s Newman notes that the next wave of space exploration is a form of soft diplomacy. “This is about the potential of the world working together,” she says.
Launius, like many others, views the moon as akin to Antarctica, which contains multiple international scientific stations. It is difficult and dangerous to access, but people do it all the time, cycling in and out in small crews. “We can do camping trips to the moon,” he says. “We can go up and spend a few days; take everything you need with you. There’s not any reason to think we don’t have the capability to put a lunar base up and stay there for some period of time. But here’s the problem: Fundamentally, going into space with humans is about becoming a multiplanetary species. If that’s not the reason, then why are we doing it? Once you do that, we’re talking not just about a lunar research station.”
It is hard to talk in practical terms about such grand ideas, Launius says. And right now, when multiple countries are planning moon bases and space stations, practicality is rearing its head. Space travel is more possible than ever, and we know more about it than ever, so the danger is more clear and present than it was in the past. What is more, Launius believes the U.S. is more averse to risk now than it was during the Apollo age.
“We all do this risk calculation,” he says. “If I’m standing on the corner waiting to cross, and I see a car 100 yards [91 meters] away, I may decide I can make that. But the person next to me may not. That’s an understandable problem, and it’s different from person to person. NASA is cautious because they’ve had some really close calls, and they’ve had some accidents in which they’ve lost astronauts. But I think we may be a little more risk-averse now, as a society.”
The space agency is also a huge ship, powered by taxpayers and steered by politics. Exploration advocates have seen moon-return programs announced, hyped, planned and then canceled several times since the 1970s. Decades of uncertainty are one reason some scientists are so eager to work with the private sector—and vice versa. Watkins serves on a science advisory panel for Amazon founder Jeff Bezos’s space exploration company Blue Origin, and she says the company is keen to work with scientists to decide where to land and which kinds of experimental equipment to bring. Private corporations, beholden to stockholders or a few owners, might have a different tolerance for risk than a government agency that answers to the many.
While some exploration advocates argue that NASA needs to dream bigger or cut red tape out of the way, many scientists say simply realizing that space can kill us is not the problem. What does not kill us could make us stronger.
“It’s not that people aren’t dreaming big. Sending a crew to the lunar south pole is big,” Watkins says of NASA’s planned Artemis mission to land humans on the moon. “We just have more knowledge, which isn’t a bad thing at all. We know more, and that means we can also prepare better.”