That Covid-19 reinfection in Hong Kong was followed by similar reports in Belgium and the Netherlands. It was announced today that a 27-year-old woman in Karnataka, India also tested positive for the disease a second time (though the government is still seeking confirmation), and now researchers in Nevada are also reporting a "likely" case of reinfection.

The health-news site Stat reports: What caught experts' attention about the case of the 25-year-old Reno man was not that he appears to have contracted SARS-CoV-2 (the name of the virus that causes Covid-19) a second time. Rather, it's that his second bout was more serious than his first. Immunologists had expected that if the immune response generated after an initial infection could not prevent a second case, then it should at least stave off more severe illness. That's what occurred with the first known reinfection case, in a 33-year-old Hong Kong man.

Still, despite what happened to the man in Nevada, researchers are stressing this is not a sky-is-falling situation or one that should result in firm conclusions. They always presumed people would become vulnerable to Covid-19 again some time after recovering from an initial case, based on how our immune systems respond to other respiratory viruses, including other coronaviruses. It's possible that these early cases of reinfection are outliers and have features that won't apply to the tens of millions of other people who have already shaken off Covid-19. "There are millions and millions of cases," said Michael Mina, an epidemiologist at Harvard's T.H. Chan School of Public Health. The real question that should get the most focus, Mina said, is, "What happens to most people...?"

Researchers are finding that, generally, people who get Covid-19 develop a healthy immune response replete with both antibodies (molecules that can block pathogens from infecting cells) and T cells (which help wipe out the virus). This is what happens after other viral infections.

"But is that such a bad thing?" asks Popular Mechanics: Earlier this week, Elon Musk said there's a "good chance" settlers in the first Mars missions will die. And while that's easy to imagine, he and others are working hard to plan and minimize the risk of death by hardship or accident. In fact, the goal is to have people comfortably die on Mars after a long life of work and play that, we hope, looks at least a little like life on Earth...

[T]he trip itself will take a year based on current estimates, and applicants to settlement programs are told to expect this trip to be one way. It follows, statistically, that there's an almost certain "chance" these settlers will die on Mars, because their lives will continue there until they naturally end. Musk is referring to accidental death in tough conditions, but people are likely to stay on Mars for the duration either way.

When Mars One opened applications in 2013, people flocked to audition to die on Mars after a one-way trip and a lifetime of settlement. As chemist and applicant Taylor Rose Nations said in a 2014 podcast episode: "If I can go to Mars and be a human guinea pig, I'm willing to sort of donate my body to science...."
Musks exact words: "I want to emphasize that this is a very hard and dangerous, difficult thing, not for the faint of heart. Good chance you'll die, it's going to be tough going, but it will be pretty glorious if it works out."

sciencehabit quotes Science magazine: About 3000 years ago, thousands of warriors fought on the banks of the Tollense river in northern Germany. They wielded weapons of wood, stone, and bronze to deadly effect: Over the past decade, archaeologists have unearthed the skeletal remains of hundreds of people buried in marshy soil. It's one of the largest prehistoric conflicts ever discovered. Now, genetic testing of the skeletons reveals the homelands of the warriors—and unearths a shocker about early European diets: These soldiers couldn't digest fresh milk...

The results leave scientists more puzzled than ever about exactly when and why Europeans began to drink milk. "Natural genetic drift can't explain it, and there's no evidence that it was population turnover either," says Christina Warinner, a geneticist at Harvard University and the Max Planck Institute for the Science of Human History who was not involved with the study. "It's almost embarrassing that this is the strongest example of selection we have and we can't really explain it."

Perhaps something about fresh milk helped people ward off disease in the increasingly crowded and pathogen-ridden European towns and villages of the Iron Age and Roman period, says the study's co-author. But he admits he's baffled too. "We have to find a reason why you need this drink."

NCamero (Slashdot reader #35,481) brings some news from the world of 12-sided dodecahedrons: Quanta magazine reports that a trio of mathematicians has resolved one of the most basic questions about the dodecahedron. The cube, tetrahedron, octahedron and icosahedron cannot have a straight path you could take [starting from a corner] that would eventually return you to your starting point without passing through any of the other corners. The dodecahedron can.
Mathematicians studied dodecahedrons for over 2,000 years without solving the problem, reports Quanta magazine. But now... Jayadev Athreya, David Aulicino and Patrick Hooper have shown that an infinite number of such paths do in fact exist on the dodecahedron. Their paper, published in May in Experimental Mathematics, shows that these paths can be divided into 31 natural families. The solution required modern techniques and computer algorithms.

"Twenty years ago, [this question] was absolutely out of reach; 10 years ago it would require an enormous effort of writing all necessary software, so only now all the factors came together," wrote Anton Zorich, of the Institute of Mathematics of Jussieu in Paris, in an email.

Science Alert reports: People who eat a lot of industrially processed junk food are more likely to exhibit a change in their chromosomes linked to aging, according to research presented Tuesday at an online medical conference. Three or more servings of so-called "ultra-processed food" per day doubled the odds that strands of DNA and proteins called telomeres, found on the end of chromosomes, would be shorter compared to people who rarely consumed such foods, scientists reported at the European and International Conference on Obesity.

Short telomeres are a marker of biological aging at the cellular level, and the study suggests that diet is a factor in driving the cells to age faster. While the correlation is strong, however, the causal relationship between eating highly processed foods and diminished telomeres remains speculative, the authors cautioned.

"SpaceX took another step forward Thursday in developing its next-generation Starship rocket, conducting the second short flight test of a prototype in the past month," reports CNBC: Starship prototype Serial Number 6, or SN6, took off from the launchpad at SpaceX's facility in Boca Chica, Texas. It gradually rose to about 500 feet above the ground before it returned back to land, touching down on a concrete area near the launchpad. The flight test appeared to be identical to the test SpaceX conducted of prototype SN5 on Aug. 5...

The company is developing Starship with the goal of launching cargo and as many as a 100 people at a time on missions to the Moon and Mars.

SpaceX has been steadily building multiple prototypes at a time at the company's growing facility in Boca Chica. While SpaceX's fleet of Falcon 9 and Falcon Heavy rockets are partially reusable, Musk's goal is to make Starship fully reusable — envisioning a rocket that is more akin to a commercial airplane, with short turnaround times between flights where the only major cost is fuel. After SpaceX in May launched a pair of NASA astronauts in its first crewed mission, Musk pivoted the company's attention, declaring that the top SpaceX priority is now development of Starship. Musk said in an email obtained by CNBC that Starship's program must accelerate "dramatically and immediately..."

He expects Starship's first flight tests to orbit won't come until 2021, saying that SpaceX is in "uncharted territory."
Commenting on the test launch of the bulky spacecraft, Elon Musk tweeted "Turns out you can make anything fly haha."

schwit1 shares a report from NASASpaceFlight: China launched a new experimental reusable space vehicle on Thursday from the Jiuquan Satellite Launch Center using a Long March-2F/T -- Chang Zheng-2F/T -- launch vehicle. Launch from the LC43/91 launch complex, under a veil of secrecy with no official launch photos or even a launch time disclosed. Chinese media emitted a laconic report referring, that "the test spacecraft will be in orbit for a period of time before returning to the domestic scheduled landing site. During this period, it will carry out reusable technology verification as planned to provide technical support for the peaceful use of space."

An anonymous reader quotes a report from The Verge: Today, the Trump administration released its fifth Space Policy Directive, this one designed to come up with a list of best practices for the space industry on how to protect their spacecraft from cyber threats. The goal is to encourage the government and space industry to create their space vehicles with cybersecurity plans in place, incorporating tools like encryption software and other protections when designing, building, and operating their vehicles. [...] To combat these threats, Space Policy Directive 5 lays out guidelines that companies should try to adhere to as they launch satellites and other vehicles to space. The administration is recommending operators use various types of software to ensure that the data they receive from their spacecraft is encrypted. The directive also encourages companies to use trusted supply chains and oversee the safety of their ground systems -- the facilities they use to send signals and retrieve data from their spacecraft. The report also recommends protecting against jamming and spoofing of satellites. "Sometimes the jamming can be fairly crude; other cases, some of the spoofing can be fairly sophisticated if somebody's trying to get on board," one official said. "So there's a whole range of things that you need to look at kind of end-to-end."

Ultimately, the directive says that government agencies should work with commercial companies to further refine what these best cybersecurity practices should be, especially since many in the space industry already implement these strategies when building and launching vehicles. [...] SPD-5 is the latest policy directive from the Trump administration designed to shape the U.S. space agenda. Trump's first directive instructed NASA to send humans back to the Moon, while other directives have focused on coming up with a way to oversee space traffic and streamlining regulations for space licenses.

Russia's "Sputnik-V" COVID-19 vaccine produced an antibody response in all participants in early-stage trials, according to results published on Friday by The Lancet medical journal that were hailed by Moscow as an answer to its critics. Reuters reports: The results of the two trials, conducted in June-July this year and involving 76 participants, showed 100% of participants developing antibodies to the new coronavirus and no serious side effects, The Lancet said. Russia licensed the two-shot jab for domestic use in August, the first country to do so and before any data had been published or a large-scale trial begun. "The two 42-day trials -- including 38 healthy adults each -- did not find any serious adverse effects among participants, and confirmed that the vaccine candidates elicit an antibody response," The Lancet said. "Large, long-term trials including a placebo comparison, and further monitoring are needed to establish the long-term safety and effectiveness of the vaccine for preventing COVID-19 infection," it said.

The vaccine is named Sputnik-V in homage to the world's first satellite, launched by the Soviet Union. Some Western experts have warned against its use until all internationally approved testing and regulatory steps have been taken. But with the results now published for the first time in an international peer-reviewed journal, and with a 40,000-strong later-stage trial launched last week, a senior Russian official said Moscow had faced down its critics abroad. "With this (publication) we answer all of the questions of the West that were diligently asked over the past three weeks, frankly with the clear goal of tarnishing the Russian vaccine," said Kirill Dmitriev, the head of the Russian Direct Investment Fund (RDIF), Russia's sovereign wealth fund, which has backed the vaccine. "All of the boxes are checked," he told Reuters. "Now... we will start asking questions of some of the Western vaccines."

Antibodies that people make to fight the new coronavirus last for at least four months after diagnosis and do not fade quickly as some earlier reports suggested, scientists have found. From a report: Tuesday's report, from tests on more than 30,000 people in Iceland, is the most extensive work yet on the immune system's response to the virus over time, and is good news for efforts to develop vaccines. If a vaccine can spur production of long-lasting antibodies as natural infection seems to do, it gives hope that "immunity to this unpredictable and highly contagious virus may not be fleeting," scientists from Harvard University and the U.S. National Institutes of Health wrote in a commentary published with the study in the New England Journal of Medicine. One of the big mysteries of the pandemic is whether having had the coronavirus helps protect against future infection, and for how long. Some smaller studies previously suggested that antibodies may disappear quickly and that some people with few or no symptoms may not make many at all. The new study was done by Reykjavik-based deCODE Genetics, a subsidiary of the U.S. biotech company Amgen, with several hospitals, universities and health officials in Iceland. The country tested 15% of its population since late February, when its first COVID-19 cases were detected, giving a solid base for comparisons.

New submitter fx4m writes: Historic Lick Observatory in California survived the current massive wildfires, but the nearby, much smaller Hidden Hill Observatory, run my the Tri-Valley Stargazers Astronomy Club, was not so lucky. The building, large amateur-built telescope, accessories, and electronics were all completely destroyed. Much of the assets of the science public outreach and education based non-profit organization went up in smoke. A description of the observatory, its history, and sad pictures of the destruction can be found at the link, with more information at their GoFundMe page.

sciencehabit writes: Every year, mining and industrial activity generates billions of tons of slurries, gravel, and other wastes that have a high pH. These alkaline wastes, which sit either behind fragile dams or heaped in massive piles, present a threat to people and ecosystems. But alkaline wastes could also help the world avert climate disaster. Reacting these wastes with carbon dioxide (CO2) from the air converts gaseous carbon into minerals and neutralizes the wastes' alkalinity. Carrying this out on a global scale could trap between 310 million to 4 billion tons of CO2 annually, according to recent surveys. That could provide the world with a much needed means of lowering atmospheric CO2. But there are major hurdles. Governments will need to offer incentives for mineralization on the massive scale needed to make a dent in atmospheric carbon. And engineers will need to figure out how to harness the wastes while preventing the release of heavy metals and radioactivity locked in the material.

The Trump administration will decline to pay tens of millions of dollars owed to the World Health Organization (WHO) in annual dues as part of the U.S.'s withdrawal from the global body, which is scheduled for next year. The Hill reports: The Associated Press reported that the U.S. will not pay just over $60 million owed in 2020 dues to the organization, and Reuters reported that the decision also will affect about $19 million still owed in 2019 dues. A decision to forgo the payments comes as the Trump administration has hammered the WHO for months over supposedly bowing to China's wishes and essentially acting as a PR shop for China's government during the early stages of the pandemic while Chinese officials allegedly stymied international health experts from learning about the virus.

In a statement, a WHO spokesperson said the agency would review its options and encourage the U.S. to reverse course. "We refer you to our previous statements of regret regarding the U.S. decision to withdraw. We await further details, which we will consider carefully," the spokesperson told Reuters.

Rust requires oxygen, water, and the right conditions, all of which the Moon lacks. So where did a newly discovered iron oxide come from? Earth is one possibility. From a report: Contrary to what was thought to be a scientific impossibility, scientists detected rust -- a product that requires oxygen, water, and oxidative conditions -- on the surface of the Moon, a famously oxygen-poor, liquid water-less, and reducing environment that prohibits oxidation. The scientists speculated that the oxygen needed for the reaction that forms rust had been carried to the poles of the Moon by wind from the Earth, and a paper detailing the discovery was published on Wednesday in the journal Science Advances. Rust is the reddish-brown material left behind when iron atoms react with oxygen and water in what is known as an oxidizing, or electron-losing, reaction. The Moon's very thin atmosphere does not trap much oxygen, and solar winds constantly blast the surface of the Moon with charged hydrogen, causing it to have highly reducing, or electron-gaining, conditions.

So while rust is common on Earth, its discovery on the Moon caught researchers by surprise. "I don't think anyone expected this on the Moon's surface," said Shaui Li, the first author of the paper and a researcher at the University of Hawai'i at Manoa. "This is basic chemistry -- we all know that the lunar surface is highly reducing, so there is no reason you would be able to see a high-valence iron like hematite." By comparing reflectance data collected by the Indian Chandrayaan-1 mission to pure samples of rust, Li's group identified material at latitudes above 60 degrees on the Moon's surface as hematite, or iron (III) oxide. Li said that the comparison was fairly straightforward, and he is very confident that the reflectance spectra were of hematite.

An anonymous reader shares a report: The smell of summer in Los Angeles, or any major city, is often tinged with asphalt. A freshly paved road or a new tar roof doesn't just wrinkle your nose, however: A new study suggests fresh asphalt is a significant, yet overlooked, source of air pollution. In fact, the material's contribution to one kind of particulate air pollution could rival or even exceed that of cars and trucks. "It's a super cool paper," says Allen Robinson, an environmental engineer at Carnegie Mellon University who was not involved with the research. "Asphalt could be a big, important contributor" to air pollution, he says. Air quality has improved over the past several decades in California and many other parts of the United States, largely because of cleaner exhaust from vehicles and power plants. Despite that, air pollution still contributes to many health problems -- ranging from asthma to heart attacks. And many sources of air pollution continue to be a problem, from livestock emissions to volatile organic compounds from paints, cleaning products, and personal care products (especially those that contain fragrances, such as shampoo).

Yet, when scientists looked at all the known sources of air pollution in Los Angeles and the surrounding areas, they didn't add up. Some sources had not yet been identified. "Asphalt was something that jumped out to us," says Drew Gentner, an environmental engineer at Yale University who led the new study. The material, made from crude oil or similar substances, contains the kinds of semivolatile organic compounds that lead to some types of air pollution. There's also a lot of it. Gentner and colleagues gathered two types of fresh road asphalt and heated them in a laboratory furnace. They also tested new asphalt shingles and liquid asphalts used for roofing. They reasoned that new material should release more chemicals than older material, and they wanted to see how the emission rate changes as the fresh asphalt ages.

On Thursday morning a Falcon 9 rocket lifted off from Kennedy Space Center, carrying SpaceX's 12th batch of Starlink Internet satellites. The mission went nominally, with the first stage making a safe landing several minutes after the launch, and the full stack of satellites deploying shortly thereafter. From a report: Prior to launch, webcast commentator Kate Tice, a senior program reliability engineer at SpaceX, offered several details about development of the space-based Starlink Internet service. "We are well into our first phase of testing of our private beta program, with plans to roll out a public beta later this year," Tice said. For several months, SpaceX has been collecting names and addresses for people interested in participating in the public beta here. Tice also revealed the first official public information about internal tests, saying that SpaceX employees have been using Starlink terminals, collecting latency statistics, and performing standard speed tests of the system. "Initial results have been good," she said. These tests reveal "super-low latency," and download speeds greater than 100 megabits per second. This, she noted, would provide enough bandwidth to play the fastest online games and stream multiple HD movies at once.

On Wednesday afternoon in Northern Utah, Northrop Grumman successfully fired up a full-scale test version of the boosters it is building for NASA's Space Launch System rocket. "Two of these large boosters, each with a mass of 1.6 million pounds, account for 75 percent of the SLS rocket's thrust during the first two minutes of flight," reports Ars Technica. "They are composed of five segments of a powderized, solid fuel that is ignited upon launch. Northrop has already built 26 of the 30 segments NASA needs for the first three launches of the SLS rocket." From the report: The primary reason for Wednesday's test was that Northrop's supplier of aluminum-based fuel could no longer deliver the product. Therefore, Northrop needed to ensure that a new vendor could provide the solid rocket fuel needed for future launches of the SLS rocket beyond the first three. NASA also used the test to assess some changes to the nozzle design, said Bruce Tiller, manager of the SLS boosters office at NASA's Marshall Space Flight Center. With this test, Tiller said NASA remains on track to potentially launch the SLS rocket in late 2021. The boosters for this flight are already being stacked in Florida. The main question is whether the rocket's large core stage, which is set to undergo a critical test firing in Mississippi this fall, will be ready to go. These solid rocket boosters are a holdover from the space shuttle era, when they powered that vehicle. However, the new boosters have been modernized with improved avionics and made more powerful with the addition of a fifth segment.

schwit1 shares a report from the New York Post: As governments around the world scramble to approve a vaccine against the deadly coronavirus, an increasing number of scientists have started administering DIY vaccines to themselves and even their friends and family members. The methods, results, and claims have varied widely among the dozens of scientists around the world who have taken this unconventional route.

One such effort is by scientist Johnny Stine, who runs North Coast Biologics, a biotech company in Seattle. In June, Washington attorney general slapped Stine with a lawsuit for administering his DIY vaccine to San Juan Island Mayor Farhad Ghatan and around 30 people, charging them $400, the New York Times reported. Another vaccine effort going outside FDA approval is the Rapid Deployment Vaccine Collaborative, or RaDVaC, which has among its 23 collaborators Harvard geneticist George Church. Proponents have welcomed the idea of going outside the normal regulatory process, given the extraordinary circumstances of the pandemic. But critics say these DIY vaccines are not being put to the test of placebo-controlled studies and could have unforeseen negative consequences.

An anonymous reader quotes a report from Gizmodo: Engineers at Purdue University have created a printing process by which you can coat paper or cardboard with "highly fluorinated molecules." This then makes the coated paper dust, oil, and water-repellent, meaning you can then print multiple circuit layers onto the paper without smudging the ink. According to a paper the engineers published in Nano Energy, these "triboelectric areas" are then capable of "self-powered Bluetooth wireless communication." That's science-speak to say that paper printed and coated in this way doesn't require external batteries as it generates electricity from contact with a user's finger.

You can see a demonstration of how the tech works in these two videos. In the first video, Purdue engineers have a paper keypad that's been treated with the aforementioned "omniphobic" coating. The paper keypad is then doused in some neon-green solution. In the second video, you can then see a person use the paper keypad to actually type on a laptop with a disabled keyboard. In a third video, Purdue's team printed a forward, back, mute, and volume bar on the back of a piece of paper. In it, you can see someone controlling audio playback by dragging their finger along the volume bar, as well as skipping forward and back in the music queue. While the tech itself is pretty cool, another neat aspect is that because it works on paper and cardboard, it would be relatively inexpensive, flexible, and quick to make. That makes it a good candidate for things like smart packaging.

Thelasko shares a report from Medium: Earlier this summer, the Summit supercomputer at Oak Ridge National Lab in Tennessee set about crunching data on more than 40,000 genes from 17,000 genetic samples in an effort to better understand Covid-19. Summit is the second-fastest computer in the world, but the process -- which involved analyzing 2.5 billion genetic combinations -- still took more than a week. When Summit was done, researchers analyzed the results. It was, in the words of Dr. Daniel Jacobson, lead researcher and chief scientist for computational systems biology at Oak Ridge, a 'eureka moment.' The computer had revealed a new theory about how Covid-19 impacts the body: the bradykinin hypothesis. The hypothesis provides a model that explains many aspects of Covid-19, including some of its most bizarre symptoms. It also suggests 10-plus potential treatments, many of which are already FDA approved. Jacobson's group published their results in a paper in the journal eLife in early July.

According to the team's findings, a Covid-19 infection generally begins when the virus enters the body through ACE2 receptors in the nose, (The receptors, which the virus is known to target, are abundant there.) The virus then proceeds through the body, entering cells in other places where ACE2 is also present: the intestines, kidneys, and heart. This likely accounts for at least some of the disease's cardiac and GI symptoms. But once Covid-19 has established itself in the body, things start to get really interesting. According to Jacobson's group, the data Summit analyzed shows that Covid-19 isn't content to simply infect cells that already express lots of ACE2 receptors. Instead, it actively hijacks the body's own systems, tricking it into upregulating ACE2 receptors in places where they're usually expressed at low or medium levels, including the lungs.

The renin-angiotensin system (RAS) controls many aspects of the circulatory system, including the body's levels of a chemical called bradykinin, which normally helps to regulate blood pressure. According to the team's analysis, when the virus tweaks the RAS, it causes the body's mechanisms for regulating bradykinin to go haywire. Bradykinin receptors are resensitized, and the body also stops effectively breaking down bradykinin. (ACE normally degrades bradykinin, but when the virus downregulates it, it can't do this as effectively.) The end result, the researchers say, is to release a bradykinin storm -- a massive, runaway buildup of bradykinin in the body. According to the bradykinin hypothesis, it's this storm that is ultimately responsible for many of Covid-19's deadly effects. Several drugs target aspects of the RAS and are already FDA approved, including danazol, stanozolol, and ecallantide, which reduce bradykinin production and could potentially stop a deadly bradykinin storm.

Interestingly, the researchers suggest vitamin D as a potentially useful Covid-19 drug. "The vitamin is involved in the RAS system and could prove helpful by reducing levels of another compound, known as REN," the report says. "Again, this could stop potentially deadly bradykinin storms from forming." Other compounds could treat symptoms associated with bradykinin storms, such as Hymecromone and timbetasin.