This is the first story in a new occasional article series we're calling Slashback. We'll be covering a topic that may not be breaking news, but is interesting to us. Today's Slashback story features an article from Scientific American highlighting the profound effect of severe social isolation on the brain. From the report: The feeling of "wanting" something has repeatedly been shown to increase dopamine transmission in the brain reward circuit (see here and here). This circuit consists of the dopamingeric midbrain and the striatum. These areas are particularly active in response to images of food when hungry, to drug-related images for those who are addicted, and people with Internet Gaming Disorder who are deprived of gaming (see here, here, and here). What about social interactions? For social animals, it would make sense that social interactions would be a primary reward. However, so far such research has primarily been conducted on mice. In 2016, Gillian Matthews and colleagues published a paper showing that after 24 hours of social isolation, dopamine neurons in the midbrain were activated when mice sought social interaction. These dopamine neurons showed similar activation patterns to other cravings. It appears that the acute social isolation in these mice led to an aversive "loneliness-like" state that increased motivation for social engagement. Nevertheless, researchers have questioned whether these findings would apply to humans, especially since it's not possible to assess whether a mouse subjectively feels lonely.

Livia Tomova, a postdoctoral fellow in the Saxelab at MIT, was inspired by this earlier research on mice and pitched to Rebecca Saxe the idea of trying to replicate the findings in humans. [...] What did the researchers find? After only ten hours of social isolation-- and even despite people knowing exactly when their deprivation would end-- people reported substantially more social craving, loneliness, discomfort, dislike of isolation, and decreased happiness than they did at baseline. Similarly, the same findings were seen after ten hours of food fasting. Critically, the researchers found similar midbrain activity in response to food cues after fasting and social cues after isolation. The response was variable across participants, and those who reported more social craving after the social isolation period showed a larger brain response to the social stimuli. Interestingly, the variability across participants was also partially explained by the variability in pre-existing chronic levels of loneliness. Participants with higher levels of chronic loneliness at baseline reported less craving for social contact after 10 hours of isolation in response to the social stimuli, and showed a muted response in their midbrain in response to the social cues after social isolation (they also showed reduced midbrain responses to food cues after fasting). This finding is consistent with prior research showing that chronic loneliness is associated with reduced motivation to engage socially with others.

These results are exciting because they are consistent with the results from earlier research on mice and the "social homeostasis" hypothesis developed based on animal models. According to this hypothesis, since social connection is an innate need, animals evolved neural system to regulate "social homeostasis." The current findings suggest that there is a similar mechanism underlying social craving in humans, and that people who are forced to be isolated crave social interactions in a similar way as a hungry person craves food. As the researchers note, these findings are also encouraging for translating mouse models of mental health disorders that affect social motivation, such as autism spectrum disorder, social anxiety disorder, or depression. While the article makes little to no mention of the coronavirus, it does make one ponder how the mandated period of isolation associated with it will affect us, especially as local governments around the country begin to lift restrictions and reopen.

What happens when a person starved of food is suddenly presented with the ability to eat? They gorge themselves. What about when a person who has been socially isolated for weeks suddenly gets to socialize? Perhaps they'll jump on the chance to surround themselves with others. We're already starting to see more people booking local holidays...

With dozens of digital contact tracing apps already rolled out worldwide, and many more on the way, how many people need to use them for the system to work? One number has come up over and over again: 60%. From a report: That's the percentage of the population that many public health authorities documented by MIT Technology Review's Covid Tracing Tracker say they are targeting as they attempt to protect their communities from covid-19. The number is taken from an Oxford University study released in April. But since no nation has reached such levels, many have criticized "exposure notification" technologies as essentially worthless. But the researchers who produced the original study say their work has been profoundly misunderstood, and that in fact much lower levels of app adoption could still be vitally important for tackling covid-19.

"There's been a lot of misreporting around efficacy and uptake ... suggesting that the app only works at 60% -- which is not the case," says Andrea Stewart, a spokeswoman for the Oxford team. In fact, she says, "it starts to have a protective effect" at "much lower levels." The Oxford models found that "the app has an effect at all levels of uptake" as illustrated by this graph which shows every level of adoption slowing to pandemic to some extent. Because of the way such digital contacting tracing and exposure notification apps work -- by notifying users if their phone has been in proximity to the phone of somebody who later gets a diagnosis of covid-19 -- blanket coverage is preferable. The greater the number of users, the higher the likelihood that it will help at-risk people to self-quarantine before they can infect others.

The search habits of thousands of South Korean senior citizens "are being monitored through virtual-assistant smart speaker technology," writes Slashdot reader shirappu. The AP reports that around 3,200 people across the country, "mostly older than 70 and living alone, have so far allowed the SK Telecom speakers to listen to them 24 hours a day since the service launched in April 2019."

It's part of a larger look at whether technology has become too invasive, in a country where health authorities have also "aggressively used credit-card records, surveillance videos and cellphone data to find and isolate potential virus carriers." Locations where patients went before they were diagnosed are published on websites and released through cellphone alerts. Smartphone tracking apps are used to monitor around 30,000 individuals quarantined at home... [E]ntertainment venues in Seoul, Incheon and Daejeon will be required to register customers with smartphone QR codes so they can be easily located if needed. The requirement expands nationwide on June 10. But there's a dark side. People here have often managed to trace back the online information to the unnamed virus carriers, exposing embarrassing personal details and making them targets of public contempt...

President Moon Jae-in's administration has said data-driven industries will be critical in boosting a pandemic-hit economy. Officials are preparing regulations for revised data laws that lawmakers passed in January after months of wrangling. They aim to allow businesses greater freedom in collecting and analyzing anonymous personal data without seeking individual consent. If they work as intended, optimists say the laws would allow artificial intelligence to truly take off and pave the way for highly customized financial and health care services after they start in August.

But activist Oh Byoung-il said the changes could bring excessive privacy infringements unless robust safeguards are installed. "Companies will always have an endless thirst for data, but you can't give it to them all," he said.

Long-time Slashdot reader heretic108 writes: Following its "go early and go hard" lockdown regime, New Zealand's active COVID-19 case count has now reached zero. Stringent border quarantine rules remain in place, however, and New Zealand is just now starting to count the economic cost.
New Zealand has now marked 17 days in a row without a new case, according to the article. Throughout a population of 4.8 million, to date there have been just 1,504 "confirmed and probable cases," and the death toll remains at 22.

"Laboratories across the country have completed 294,848 tests."

Writing for Quanta magazine, an adjunct professor of neuroscience at the University of Maryland described an intriguing study led by MIT neuroscientist Li-Huei Tsai: Incredible as it may sound, the researchers improved the brains of animals with Alzheimer's simply by using LED lights that flashed 40 times a second. Even sound played at this charmed frequency, 40 hertz, had a similar effect.... Exposing the mice to both stimuli, a light show synchronized with pulsating sound, had an even more powerful effect, reducing amyloid plaques [a hallmark of Alzheimer's disease] in regions throughout the cerebral cortex, including the prefrontal region, which carries out higher-level executive functions that are impaired in Alzheimer's.

I was amazed, so just to make sure I wasn't getting unduly excited about the possibility of using flashing lights and sounds to treat humans, I talked to Hiroaki Wake, a neuroscientist at Kobe University in Japan who was not involved with the work. "It would be fantastic!" he said. "The treatment may also be effective for a number of neurodegenerative disorders like Parkinson's disease and ALS," where microglia also play a role... Tsai's team has just begun assessing their strobe-light method on patients, and they're sure to be joined by others as more researchers learn of this promising work.
According to the article, another study at the Georgia Institute of Technology is investigating a specific mechanism with which doctors "could potentially treat different diseases just by varying the light and sound rhythms they use.

"The different stimuli would rock the neurons into producing appropriate brain wave frequencies, causing nearby microglia to release specific types of cytokines, which tell microglia in general how to go to work repairing the brain."

A reader quotes MIT's Technology Review: Three thousand light-years from Earth sits Kepler 160, a sun-like star that's already thought to have three planets in its system. Now researchers think they've found a fourth. Planet KOI-456.04, as it's called, appears similar to Earth in size and orbit, raising new hopes we've found perhaps the best candidate yet for a habitable exoplanet that resembles our home world. The new findings bolster the case for devoting more time to looking for planets orbiting stars like Kepler-160 and our sun, where there's a better chance a planet can receive the kind of illumination that's amenable to life.

Most exoplanet discoveries so far have been made around red dwarf stars. This isn't totally unexpected; red dwarfs are the most common type of star out there. And our main method for finding exoplanets involves looking for stellar transits — periodic dips in a star's brightness as an orbiting object passes in front of it. This is much easier to do for dimmer stars like red dwarfs, which are smaller than our sun and emit more of their energy as infrared radiation. The highest-profile discovery of this type is near our closest neighboring star, Proxima Centauri — a red dwarf with a potentially habitable planet called Proxima b (whose existence was, incidentally, confirmed in a new study published this week).

Data on the new exoplanet orbiting Kepler 160, published in Astronomy and Astrophysics on Thursday, points to a different situation entirely. From what researchers can tell, KOI 456.04 looks to be less than twice the size of Earth and is apparently orbiting Kepler-160 at about the same distance from Earth to the sun (one complete orbit is 378 days). Perhaps most important, it receives about 93% as much light as Earth gets from the sun.

sciencehabit quotes Science magazine: In a famous Siberian experiment carried out the 1950s, scientists turned foxes into tame, doglike canines by breeding only the least aggressive ones generation after generation. The creatures developed stubby snouts, floppy ears, and even began to bark.

Now, it appears that some rural red foxes in the United Kingdom are doing this on their own. When the animals moved from the forest to city habitats, they began to evolve doglike traits, new research reveals, potentially setting themselves on the path to domestication...

Most significantly, the urban foxes, like those in the Russian experiment, had noticeably shorter and wider muzzles, and smaller brains, than their rural fellows. And males and females had very similar skull shapes. All of these changes are typical of what Charles Darwin labeled domestication syndrome. Overall, urban foxes' skulls seemed to be designed for a stronger bite than were those of rural foxes, which are shaped for speed.

Perhaps that's because in the city, a fox can simply stand at a human trash pile and feed on the food we've tossed out, where they may encounter more bones that can only be crushed with stronger jaws, Parsons speculates. Still, he emphasizes that the urban red foxes are not domesticated. But the study does show how exposure to human activity can set an animal down this path, says Melinda Zeder, an emeritus archaeologist at the Smithsonian Institution's National Museum of Natural History.

"SpaceX may be best known for revolutionizing rocket launches with its reusable rockets..." writes Digital Trends, but now, "Europe wants to get in on the action." The European Space Agency (ESA) has announced it is developing its own reusable rocket engine...with the aim of making rocket launches considerably cheaper. The ESA described its planned engine as "the precursor of ultra-low-cost rocket propulsion that is flexible enough to fit a fleet of new launch vehicles for any mission and will be potentially reusable."

The French space agency CNES, along with the aerospace company Ariane Group, unveiled its plans for a reusable rocket last year. The ESA has now chosen to fully fund the Prometheus engine design to create a usable version that it hopes can be produced considerably cheaper — down to a tenth of the cost — than current options... The ESA will soon begin testing the hardware components of the Prometheus engine at the German Space Agency facilities in Lampoldshausen, Germany. It says it already has manufactured components including the turbo pump's turbine, pump inlet, and gas generator valves, and it is currently manufacturing main subsystems.

The aim is to finish the first combustion chamber model this month, then deliver the real version of this combustion chamber by the end of the year, before assembling a full demonstration version of the engine for testing by 2021.

Iceland is the most sparsely-populated country in Europe, with a population of 364,134 spread across 40,000 square miles (103,000 square kilometers). But the New Yorker notes Iceland has "virtually eliminated" Covid-19 cases -- and tries to explore how they did it.

By February 28th, Iceland had already implemented a contact-tracing team. "And then, two hours later, we got the call," remembers a detective with the Reykjavík police department. A man who'd recently been skiing in the Dolomites had become the country's first known coronavirus patient... Anyone who'd spent more than fifteen minutes near the man in the days before he'd experienced his first symptoms was considered potentially infected. ("Near" was defined as within a radius of two metres, or just over six feet.) The team came up with a list of fifty-six names. By midnight, all fifty-six contacts had been located and ordered to quarantine themselves for fourteen days.

The first case was followed by three more cases, then by six, and then by an onslaught. By mid-March, confirmed COVID cases in Iceland were increasing at a rate of sixty, seventy, even a hundred a day. As a proportion of the country's population, this was far faster than the rate at which cases in the United States were growing. The number of people the tracing team was tracking down, meanwhile, was rising even more quickly. An infected person might have been near five other people, or fifty-six, or more. One young woman was so active before she tested positive — going to classes, rehearsing a play, attending choir practice — that her contacts numbered close to two hundred. All were sent into quarantine.

The tracing team, too, kept growing, until it had fifty-two members. They worked in shifts out of conference rooms in a Reykjavík hotel that had closed for lack of tourists. To find people who had been exposed, team members scanned airplane manifests and security-camera footage. They tried to pinpoint who was sitting next to whom on buses and in lecture halls. One man who fell ill had recently attended a concert. The only person he remembered having had contact with while there was his wife. But the tracing team did some sleuthing and found that after the concert there had been a reception. "In this gathering, people were hugging, and eating from the same trays," Pálmason told me. "So the decision was made — all of them go into quarantine." If you were returning to Iceland from overseas, you also got a call: put yourself in quarantine. At the same time, the country was aggressively testing for the virus — on a per-capita basis, at the highest rate in the world...

[B]y mid-May, when I went to talk to Pálmason, the tracing team had almost no one left to track. During the previous week, in all of Iceland, only two new coronavirus cases had been confirmed. The country hadn't just managed to flatten the curve; it had, it seemed, virtually eliminated it.
A biotech firm called deCODE Genetics (owned by the American multinational biopharmaceutical company Amgen) also offered its own facilities for screening tests, which "picked up many cases that otherwise would have been missed," according to the article. "These cases, too, were referred to the tracing team. By May 17th, Iceland had tested 15.5 per cent of its population for the virus." Meanwhile, deCODE was also sequencing the virus from every Icelander whose test had come back positive. As the virus is passed from person to person, it picks up random mutations. By analyzing these, geneticists can map the disease's spread...

[R]esearchers at deCODE found that, while attention had been focussed on Italy, the virus had been quietly slipping into the country from several other nations, including Britain. Travellers from the West Coast of the U.S. had brought in one strain, and travellers from the East Coast another. The East Coast strain had been imported to America from Italy or Austria, then exported back to Europe.

Long-time Slashdot reader mrflash818 ("Linux geek since 1999") shared a ZDNet article pointing out that SpaceX's Falcon 9 rocket has an onboard operating system that's "a stripped-down Linux running on three ordinary dual-core x86 processors. The flight software itself runs separately on each processor and is written in C/C++."

Interestingly, back in 2018 a Slashdot headline asked whether C++ was "a really terrible language," and Elon Musk replied on Twitter with his single-word answer. "Yes."

ZDNet points out that "ordinary" processors are often needed because of the multi-year development time for the spacecraft they power. Their article notes that the International Space Station actually runs on 1988-vintage 20 MHz Intel 80386SX CPUs: Of course, while those ancient chips work for the station's command and control multiplexer/demultiplexer, they're not much good for anything else. For ordinary day-in and day-out work, astronauts use HP ZBook 15s running Debian Linux, Scientific Linux, and Windows 10. The Linux systems act as remote terminals to the control multiplexer/demultiplexer, while the Windows systems are used for email, the web, and fun.

Usually, though, chips that go into space aren't ordinary chips. CPUs that stay in space must be radiation-hardened. Otherwise, they tend to fail due to the effects of ionizing radiation and cosmic rays. These customized processors undergo years of design work and then more years of testing before they are certified for spaceflight. For instance, NASA expects its next-generation, general-purpose processor, an ARM A53 variant you may know from the Raspberry Pi 3, to be ready to run in 2021...

The Dragon spacecraft's touchscreen interface is rendered using Chromium and JavaScript. If something were to go wrong with the interface, the astronauts have physical buttons to control the spacecraft.
Today the SpaceX software team answered questions on Reddit, revealing they use Chromium with a reactive library developed in-house, and that "All of our on-board computers either run Linux (with the PREEMPT_RT patch) or are microcontrollers that run bare-metal code...." Later they emphasized that for the Falcon 9 and Dragon software, "All of the application-level autonomous software is written in C++. We generally use object oriented programming techniques from C++, although we like to keep things as simple as possible.

"We do use open source libraries, primarily the standard C++ library, plus some others. However, we limit our use of open source libraries to only extremely high quality ones, and often will opt to develop our own libraries when it is feasible so that we can control the code quality ourselves."

An anonymous reader writes: When talking about the nine year gap since America last flew astronauts with their own spacecraft, it's often said that NASA didn't have a plan in place when they retired the Space Shuttle. But the reality is a lot more complicated than that. NASA was working on a new spacecraft and rocket, and even made a successful test flight two years before the last Shuttle flight, but the program ended up getting canceled when the White House Administration changed. A review concluded that completing the program "would cost at least $150 billion dollars, and even then, a return to the Moon or a mission to Mars in the foreseeable future was unlikely," according to the article. Money was instead allocated to private alternatives like Sierra Nevada's Dream Chaser spaceplane as well as Boeing's CST-100 Starliner -- though in the end it was SpaceX's Crew Dragon which would launch the next American rocket carrying American astronauts into space. "The dark horse soundly beat the entrenched giants," the article concludes, "and the democratization of space has never been closer.

"It's hard to predict what the next decade of human spaceflight will look like, but there's no question it's going to be a lot more exciting than the previous one."

sciencehabit quotes Science magazine: The classic eye exam may be about to get an upgrade. Researchers have developed an online vision test — fueled by artificial intelligence (AI) — that produces much more accurate diagnoses than the sheet of capital letters we've been staring at since the 19th century. If perfected, the test could also help patients with eye diseases track their vision at home...

[W]hen the researchers ran their "Stanford acuity test" (StAT) through 1000 computer simulations mimicking real patients, the diagnostic reduced error by 74% compared with the classic eye test, the team reports this month in the Proceedings of the AAAI Conference on Artificial Intelligence. The simulations work by starting with a known acuity score and factors in the types of mistakes a human might make. It then virtually "takes" the different eye tests in order to compare how accurate they are. The team used this instead of actual patients because it starts with the "true" acuity — something unknown in a human.

You can take StAT yourself at myeyes.ai, although the team cautions that the test isn't meant to replace doctor visits just yet.

An anonymous reader quotes Reuters: British scientists halted a major drug trial on Friday after it found that the anti-malarial hydroxychloroquine, touted by U.S. President Donald Trump as a potential "game changer" in the pandemic, was "useless" at treating COVID-19 patients. "This is not a treatment for COVID-19. It doesn't work," Martin Landray, an Oxford University professor who is co-leading the RECOVERY trial, told reporters.

"This result should change medical practice worldwide. We can now stop using a drug that is useless..."

Landray, a professor of medicine and epidemiology at Oxford University, noted the "huge speculation" about the drug as a treatment for COVID-19 but said there had been until now "an absence of reliable information from large randomised trials". He said the preliminary results from RECOVERY, which was a randomised trial, were now quite clear: hydroxychloroquine does not reduce the risk of death among hospitalised patients with COVID-19.

"If you're admitted to hospital, don't take hydroxychloroquine," he said.
The trial involved over 11,000 patients in a randomized trial begun in March.

The article ends by quoting Parastou Donyai, director of Pharmacy Practice at the University of Reading in England, who describes the announcement as "welcome relief to thousands of scientists, doctors and academics who have been crying out for proper proof of whether hydroxychloroquine works in COVID-19 or not" -- and calling the conclusion that it does not work "definitive."

Carbon dioxide levels in the atmosphere have risen strongly to a new peak this year, despite the impact of the global effects of the coronavirus crisis. The Guardian reports: The concentration of CO2 in the atmosphere reached 417.2 parts per million in May, 2.4ppm higher than the peak of 414.8ppm in 2019, according to readings from the Mauna Loa observatory in the US. Without worldwide lockdowns intended to slow the spread of Covid-19, the rise might have reached 2.8ppm, according to Ralph Keeling, a professor at the Scripps Institution of Oceanography. He said it was likely they had played a small role, but that the difference was too small to show up against other factors causing year-to-year fluctuations.

Daily emissions of carbon dioxide fell by an average of about 17% around the world in early April, according to the a comprehensive study last month. As lockdowns are eased, however, the fall in emissions for the year as a whole is only likely to be only between 4% and 7% compared with 2019. That will make no appreciable difference to the world's ability to meet the goals of the Paris agreement, and keep global heating below the threshold of 2C that scientists say is necessary to stave off catastrophic effects. If emissions reductions of 20% to 30% were sustained for six to 12 months, then the rate of increase of CO2 measured at Mauna Loa would slow, according to the Scripps scientists.

People want to help each other, even when it costs them something, and even when the motivations to help don't always align, a new study suggests. Phys.Org reports: In research published today in the journal Science Advances, sociologists found that people overwhelmingly chose to be generous to others -- even to strangers, and even when it seems one motivation to help might crowd out another. It is the first study to examine how all the established motivations to be generous interact with one another.

The study involved more than 700 people, and was designed to help researchers understand prosocial behavior. For this study, which was done online, participants had to decide how much of a 10-point endowment to give to other people. The points had monetary value to the participants; giving cost them something. Then the researchers created different scenarios that combined one or all four of the potential motivators for giving. One: The recipient of a kindness is inclined to do something nice for the giver in return. Two: A person is motivated to do something nice to someone that she saw be generous to a third person. Three: A person is likely to do good in the presence of people in their network who might reward their generosity. And four: A person is likely to "pay it forward" to someone else if someone has done something nice for her.

[David Melamed, lead author of the study and an associate professor of sociology at The Ohio State University] said that prior to the experiment, he thought the motivations for kindness might crowd one another out. "People have a self-bias," he said. "If you do something nice for me, I may weigh that more than if I see you do something nice for someone else. But we found that all the motivators still show up as predictors of how much a person is willing to give to someone else, regardless of how the differing motivators are combined." This research helps us understand the remarkable quantity and diversity of prosocial behavior we see in humans, Melamed said. "From an evolutionary perspective, it's kind of perplexing that it even exists, because you're decreasing your own fitness on behalf of others," Melamed said. "And yet, we see it in bees and ants, and humans and throughout all of nature."

Researchers at the University of Bayreuth have created a form of nitrogen that's never been seen before. Nicknamed "black nitrogen," the new substance is crystalline, occurs in two-dimensional sheets, and could one day be useful in advanced electronics. From a report: Strangely enough, the idea that black nitrogen didn't exist has long been considered a mystery. The periodic table is arranged in recurring "periods" where each column is made up of elements with similar properties. Those at the top have the fewest protons and the lowest weight, and each successive element in the group gains protons and weight. Under high pressure, elements on the top of a column usually take on structures similar to elements further down the group. These different forms are known as allotropes. Ozone is an allotrope of oxygen, for example, while graphite and diamond are both allotropes of carbon. But nitrogen only has one allotrope -- dinitrogen -- and doesn't have any that resemble heavier elements in its group. This was always considered a bit weird, but now a new study has found a previously-unknown allotrope that shows that nitrogen isn't an exception to the rule, as has long been believed.

The Apple Watch's Fall Detection feature is being credited as helping save an unresponsive man in Chandler, Arizona. AppleInsider reports: Fall Detection, introduced on the Apple Watch Series 4, can detect if a user takes a hard fall and will alert local emergency services if they don't respond within 60 seconds. The potentially life-saving capabilities of that feature were on display on April 23, when police dispatchers in Chandler received a 911 call from an automated voice, according to local media outlet KTAR. The auto-generated message indicated that an Apple Watch wearer had fallen and was not responding, and also provided authorities with the exact latitude and longitude of the man's location. When officers and the Chandler Fire Department showed up, they found that the man had fainted and collapsed.

schwit1 shares a report from UPI: Visits to hospital U.S. emergency rooms have dropped by more than 40 percent so far in 2020, compared to the same period last year, according to figures released Wednesday by the U.S. Centers for Disease Control and Prevention. The CDC researchers compared total visits so far this year to the same five-month period in 2019. The number of ER visits declined from a mean of roughly 2.1 million per week between March 31, 2019, and April 27, 2019, to a mean of 1.22 million per week during the "early pandemic" period of March 29 to April 25 of this year, according to the CDC. ER visits declined for every age group, with the largest proportional declines in children 10 years old and younger at 72 percent and children 11 to 14 years old at 71 percent, the agency said. Researchers found the largest declines in ER visits occurred in the New England states at 49 percent, as well as in the mid-Atlantic region at 48 percent. That region includes New York and New Jersey, which has been the epicenter of the U.S. COVID-19 outbreak.

ER visits related to abdominal pain and other digestive problems fell by more than 66,000 per week from year to year, while those among patients reporting musculoskeletal pain -- excluding low-back pain -- dropped by more than 52,000 per week, according to the CDC report. Visits for "sprains and strains" declined by nearly 34,000 per week, and those related to "superficial injuries" fell by nearly 31,000 per week, the researchers said. Conversely, ER visits for "exposure, encounters, screening or contact with infectious disease" increased by nearly 19,000 per week from 2019 to 2020, the analysis found. Specifically, some 18,000 ER visits occurred per week across the country for COVID-19 symptoms through the end of May, the researchers said. The researchers say more research is needed to determine whether the decline in ER visits could be attributed to "actual reductions in injuries or illness [due] to changing activity patterns during the pandemic" lockdown, or if Americans simply delayed or declined emergency care.

sciencehabit writes: Type Ia supernovae, a bright and long-lasting brand of stellar explosion, play a vital role in cosmic chemical manufacturing, forging in their fireballs most of the iron and other metals that pervade the universe. The explosions also serve as "standard candles," assumed to shine with a predictable brightness. Their brightness as seen from Earth provides a cosmic yardstick, used among other things to discover "dark energy," the unknown force that is accelerating the expansion of the universe. Astronomers have long thought that the blasts come from white dwarfs, burnt out stars once like our Sun, reignited after stealing material from a companion red giant. But evidence is mounting that other mechanisms may be causing white dwarfs to explode, making their standard candle status a puzzle.

The malaria drug hydroxychloroquine did not help prevent people who had been exposed to others with Covid-19 from developing the disease, according to the results of an eagerly awaited study that was published Wednesday in the New England Journal of Medicine. From a report: Despite a lack of evidence, many people began taking the medicine to try to prevent infection early in the Covid-19 pandemic, following anecdotal reports it could be effective and claims by President Trump and conservative commentators. Trump, too, said he took hydroxychloroquine to prevent infection. But the new study, the first double-blind randomized, placebo-controlled trial of hydroxychloroquine, found otherwise. "I think in the setting of post-exposure prophylaxis, it doesn't seem to work," said Sarah Lofgren, an assistant professor at the University of Minnesota who is a co-author of the study. Other studies of hydroxychloroquine are ongoing. Also Wednesday, the World Health Organization said it is resuming a clinical trial testing hydroxychloroquine as a treatment after pausing it over safety concerns.