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Science

Scientists Want To Fix Tooth Decay With Stem Cells (economist.com) 39

Once tooth decay has set in, all a dentist can do is fill the gap with an artificial plug -- a filling. But in a paper published in Cell, Hannele Ruohola-Baker, a stem-cell biologist at the University of Washington, and her colleagues offer a possible alternative. Economist: Stem cells are those that have the capacity to turn themselves into any other type of cell in the body. It may soon be possible, the researchers argue, to use those protean cells to regrow a tooth's enamel naturally. The first step was to work out exactly how enamel is produced. That is tricky, because enamel-making cells, known as ameloblasts, disappear soon after a person's adult teeth have finished growing. To get round that problem, the researchers turned to samples of tissue from human foetuses that had been aborted, either medically or naturally. Such tissues contain plenty of functioning ameloblasts. The researchers then checked to see which genes were especially active in the enamel-producing cells. Tooth enamel is made mostly of calcium phosphate, and genes that code for proteins designed to bind to calcium were particularly busy. They also assessed another type of cell called odontoblasts. These express genes that produce dentine, another type of hard tissue that lies beneath the outer enamel. Armed with that information, Dr Ruohola-Baker and her colleagues next checked to see whether the stem cells could be persuaded to transform into ameloblasts.

The team devised a cocktail of drugs designed to activate the genes that they knew were expressed in functioning ameloblasts. That did the trick, with the engineered ameloblasts turning out the same proteins as the natural sort. A different cocktail pushed the stem cells to become odontoblasts instead. Culturing the cells together produced what researchers call an organoid -- a glob of tissue in a petri dish which mimics a biological organ. The organoids happily churned out the chemical components of enamel. Having both cell types seemed to be crucial: when odontoblasts were present alongside ameloblasts, genes coding for enamel proteins were more strongly expressed than with ameloblasts alone. For now, the work is more a proof of concept than a prototype of an imminent medical treatment. The next step, says Dr Ruohola-Baker, is to try to boost enamel production even further, with a view to eventually beginning clinical trials. The hope is that, one day, medical versions of the team's organoids could be used as biological implants, to regenerate a patient's decayed teeth.

Space

SpaceX's Bandwagon Program Is a Big Deal (techcrunch.com) 21

Under a new initiative, named Bandwagon, SpaceX is expanding its rideshare program to cater to the demand for launches to mid-inclination orbits. TechCrunch reports: Orbital inclination refers to what part of the Earth is visible to a satellite as it rotates around the planet. A satellite in an equatorial orbit is at 0 degrees inclination; a satellite in a sun-synchronous orbit (SSO) is slightly higher than 90 degrees; and a mid-inclination orbit is around 45 degrees. Currently, SpaceX offers rideshare services on the Falcon 9 rocket to SSO through the Transporter program, which is in notoriously high demand. But mid-inclination orbits (MIOs) are appealing to a growing number of customers, especially to remote sensing companies that want to strengthen their coverage over areas like parts of Asia and the Middle East. Right now, companies must often purchase a dedicated launch from Rocket Lab if they want to position a satellite in MIO.

With the new rideshare program, called Bandwagon, SpaceX is going after this slice of the market. According to SpaceX's website, it currently has two Bandwagon missions booked for 2024 and two for 2025. If they become even close to the popularity of the Rideshare program, they could be a major threat to all other small launch providers: According to Jarrod McLachlan, director of rideshare sales at SpaceX, who spoke at the industry conference, SpaceX has delivered 682 spacecraft to orbit to date via rideshare missions.

AI

Use of AI Is Seeping Into Academic Journals - and It's Proving Difficult To Detect 40

The rapid rise of generative AI has stoked anxieties across disciplines. High school teachers and college professors are worried about the potential for cheating. News organizations have been caught with shoddy articles penned by AI. And now, peer-reviewed academic journals are grappling with submissions in which the authors may have used generative AI to write outlines, drafts, or even entire papers, but failed to make the AI use clear. Wired: Journals are taking a patchwork approach to the problem. The JAMA Network, which includes titles published by the American Medical Association, prohibits listing artificial intelligence generators as authors and requires disclosure of their use. The family of journals produced by Science does not allow text, figures, images, or data generated by AI to be used without editors' permission. PLOS ONE requires anyone who uses AI to detail what tool they used, how they used it, and ways they evaluated the validity of the generated information. Nature has banned images and videos that are generated by AI, and it requires the use of language models to be disclosed. Many journals' policies make authors responsible for the validity of any information generated by AI.

Experts say there's a balance to strike in the academic world when using generative AI -- it could make the writing process more efficient and help researchers more clearly convey their findings. But the tech -- when used in many kinds of writing -- has also dropped fake references into its responses, made things up, and reiterated sexist and racist content from the internet, all of which would be problematic if included in published scientific writing. If researchers use these generated responses in their work without strict vetting or disclosure, they raise major credibility issues. Not disclosing use of AI would mean authors are passing off generative AI content as their own, which could be considered plagiarism. They could also potentially be spreading AI's hallucinations, or its uncanny ability to make things up and state them as fact.
Moon

For the First Time, China's Lunar Rover Maps 1,000 Feet Below the Moon's Dark Side (livescience.com) 32

LiveScience brings an update on China's Chang'e-4 — the first spacecraft to ever land on the far side of the moon.

Its Lunar Penetrating Radar has now mapped the lunar subsurface "in finer detail than ever before" by bouncing radio signals deep underground: Their results, which were published Aug. 7 in the Journal of Geophysical Research: Planets, reveal billions of years of previously hidden lunar history. These new data suggest the top 130 feet of the lunar surface are made up of multiple layers of dust, soil, and broken rocks, said lead study author Jianqing Feng, an astrogeological researcher at the Planetary Science Institute in Tucson, Arizona... Farther down, the scientists discovered five distinct layers of lunar lava that seeped across the landscape billions of years ago.

Scientists think our moon formed 4.51 billion years ago, not long after the solar system itself, when a Mars-size object slammed into Earth and broke off a chunk of our planet The moon then continued to be bombarded by objects from space for roughly 200 million years. Some impacts cracked the moon's surface. Like Earth, the moon's mantle at that time contained pockets of molten material called magma, which seeped out through the newly formed cracks in a series of volcanic eruptions, Feng said.

The new data from Chang'e-4 shows that process slowing down over time: Feng and his colleagues found that the layers of volcanic rock grew thinner the closer they were to the moon's surface. This suggests that less lava flowed in later eruptions compared with earlier ones. "[The moon] was slowly cooling down and running out of steam in its later volcanic stage," Feng said. "Its energy became weak over time...."

However, there could still be magma deep underneath the lunar surface, Feng said.

Moon

Russia's First Lunar Mission in Decades Crashes Into the Moon (cnn.com) 179

"Russia's first lunar mission in decades has ended in failure with its Luna 25 spacecraft crashing into the moon's surface," reports CNN: The incident, a blow to Russia's space ambitions, happened after communication with the robotic spacecraft was interrupted, a blow to Russia's space ambitions. Russia's space agency, Roscosmos, said it lost touch with Luna 25 on Saturday around 2:57 p.m. Moscow time... According to a "preliminary analysis," Luna-25 "switched to an off-design orbit" before the collision, Roscosmos said. It was not immediately clear what caused the crash... The news comes a day after the spacecraft reported an "emergency situation" as it was trying to enter a pre-landing orbit, according to Roscosmos...

The spacecraft was meant to complete Russia's first lunar landing mission in 47 years. The country's last lunar lander, Luna 24, landed on the surface of the moon on August 18, 1976... Luna 25 was seen as a proving ground for future robotic lunar exploration missions by Roscosmos. Several future Luna spacecraft were slated to make use of the same design. If it had been successful, Luna 25 would have marked a huge stride for the country's civil space program — which some experts say has faced issues for decades — and demonstrate that it could still perform in high-profile, high-stakes missions. "They were having a lot of problems with quality control, corruption, with funding," said Victoria Samson, the Washington office director for Secure World Foundation, a nonprofit that promotes the peaceful exploration of outer space, during an interview Friday.

News that Russia experienced issues with its spacecraft elicited sympathy that reverberated throughout the space community. Thomas Zurbuchen, NASA's former head of science, said in a social media post that no one in the industry "wishes bad onto other explorers... We are reminded that landing on any celestial object is anything but easy & straightforward," he said,

Thanks to long-time Slashdot reader Baron_Yam and TheNameOfNick for sharing the news.
Medicine

WHO Aspartame Safety Panel Linked To Alleged Coca-Cola Front Group (theguardian.com) 71

An anonymous reader quotes a report from The Guardian: In May, the World Health Organization issued an alarming report that declared widely used non-sugar sweeteners like aspartame are likely ineffective for weight loss, and long term consumption may increase the risk of diabetes, cardiovascular diseases and mortality in adults. A few months later, WHO declared aspartame, a key ingredient in Diet Coke, to be a "possible carcinogen," then quickly issued a third report that seemed to contradict its previous findings -- people could continue consuming the product at levels determined to be safe decades ago, before new science cited by WHO raised health concerns. That contradiction stems from beverage industry corruption of the review process by consultants tied to an alleged Coca-Cola front group, the public health advocacy group US Right-To-Know said in a recent report.

It uncovered eight WHO panelists involved with assessing safe levels of aspartame consumption who are beverage industry consultants who currently or previously worked with the alleged Coke front group, International Life Sciences Institute (Ilsi). Their involvement in developing intake guidelines represents "an obvious conflict of interest", said Gary Ruskin, US Right-To-Know's executive director. "Because of this conflict of interest, [the daily intake] conclusions about aspartame are not credible, and the public should not rely on them," he added. [...] Ilsi describes itself as a nonprofit that conducts "science for the public good", but it was founded in 1978 by a Coca-Cola executive who simultaneously worked for the company through 2021, US Right-To-Know found. Other Coca-Cola executives have worked with the group, and US Right-To-Know detailed tax returns that show millions in donations from Coca-Cola and other beverage industry players. Coke ended its official membership with the group in 2021.

Over the years, Ilsi representatives have sought to shape food policy worldwide, and Ruskin, who has written multiple peer-reviewed papers on the group, characterized the aspartame controversy as a "masterpiece in how Ilsi worms its way into these regulatory processes." US Right To Know identified six out of 13 Jefca panel members with ties to the industry group. After it released its report, the WHO acknowledged two more of its members with industry ties. In a statement to the Guardian, a WHO spokesperson defended the industry consultants' inclusion in the review process. "For the meeting on aspartame, Jefca selected the experts likely to make the best contributions to the debate," said spokesperson Fadela Chaib. She said WHO's guidelines only require disclosure of conflicts of interest within the last four years. "To our knowledge, the experts you listed by name have not participated in any Ilsi activities for at least 10 years," she said. But that partially contradicts a statement made by WHO just weeks before to the news outlet Le Parisien in which it acknowledged two people currently working with Ilsi were involved in the process. The Guardian had also asked about those two people identified in the Parisien story but were not listed "by name" in its email.
The WHO told Le Parisien: "We regret that this interest was not declared by these two experts either in the written statement or orally at the opening of the meeting."
Medicine

Blue-Blocking Glasses Might Not Do Much of Anything, Says New Review 36

According to a new study of studies, researchers have concluded that blue light-filtering eyeglasses might not deliver on claims made by advertisers or optometrist offices. NewAtlas reports: To reach their conclusion, researchers at the University of Melbourne with colleagues from Monash University, and City, University of London looked at 17 published studies from six different countries relating to the use of eyeglasses that block blue light. The randomized control studies ranged in size from five to 156 participants and each took place over a time period of just less than one day to five weeks. They found that based on the current research, nothing conclusive could be said about the benefits of blue-light-blocking glasses on overall eye health, sleep quality, or visual performance. This is despite the facts that there are a range of advertising claims regarding these very benefits, and that such lenses are often prescribed for patients based on their alleged efficacy.

Downie and her team are quick to point out that even with such a comprehensive review of the current research on blue-blocking glasses, it would take a much larger study to reach truly valuable data about the use of such specs. One of the issues they point out is that none of the studies reviewed had long enough follow-up periods for the researchers to make conclusions about the long-term use of the glasses. Singh also points out that even without larger, longer, and more rigorous studies, the efficacy of blue-light-blocking glasses remains dubious. "The amount of blue light our eyes receive from artificial sources, such as computer screens, is about a thousandth of what we get from natural daylight," he said. "It's also worth bearing in mind that blue-light filtering lenses typically filter out about 10-25% of blue light, depending on the specific product. Filtering out higher levels of blue light would require the lenses to have an obvious amber tint, which would have a substantial effect on color perception."
The new study has been published in the Cochrane Database of Systematic Reviews.
Science

Genetics Makes Some People More Likely To Participate In Genetic Studies (arstechnica.com) 47

An anonymous reader quotes a report from Ars Technica: Stefania Benonisdottir and Augustine Kong at Oxford's Big Data Institute have just demonstrated that we can determine if genetic studies are biased using nothing but the genes of the participants. You may wonder how this was done -- quite reasonably, since we can't very well compare the genes of participants to those of non-participants. The analysis done by Kong and his student relies on the key idea that a genetic sequence that occurs more frequently in participants than in nonparticipants will also occur more frequently in the genetic regions that are shared by two related participants. Put differently, a bit of DNA that is common in the population will show up frequently in the study. But it will still only have a 50/50 chance of showing up in the child of someone who carried a copy. If a bit of DNA makes people more likely to enroll in genetic studies, it will be more common both in the overall data and among closely related family members.

So they checked the genetic sequences shared between first-degree relatives -- either parents and children or siblings (but not twins) -- in the UK Biobank. [...] This analysis used genetic data from about 500,000 people collected between 2006 and 2010. It examined roughly 500,000 genetic regions from around 20,000 pairs of first-degree relatives. They didn't find (or look for) "a gene" that correlates with participation in a study. Rather, they compared all of the shared and not-shared genetic sequences among the pairs of first-degree relatives enrolled in the study and analyzed their relative frequencies according to the above three principles. This analysis allowed them to calculate a polygenic score, a summary of how all of the genetic sequences in aggregate contribute to a trait. They deduced that genetics is positively associated with education level, with being invited to participate in further studies, and with accepting that invitation. Genetics was also associated with low BMI. Education level and BMI are both covariates that are often controlled for when using UK Biobank data. But now, no external information is needed; the ascertainment bias can be determined not from looking at other things about the participants' lives, but from their genes.

Benonisdottir, the first author of the work, explained in an email: "It has previously been reported by others that the UK Biobank is not representative with regard to many traits, including BMI and educational attainment. Thus, the fact that these traits are associated with the participation polygenic score, which does not use any information about EA and BMI but is constructed with weights from analysis using our new method of comparing shared and not-shared alleles of participating first-degree relatives, validates that our method is capturing real information about participation." This validation is essential, since their method is so new. The authors of this study propose that their methodology could be used to look for ascertainment bias using only genetic data and that taking participation data into account could help study outcomes become more accurate. They conclude by noting that "participation" is not thus just a result of someone's characteristics and traits; rather, the propensity to participate is a trait in its own right, and one with a genetic component. Being a joiner is hereditary.

Science

LK-99 Isn't a Superconductor - How Science Sleuths Solved the Mystery (nature.com) 94

Researchers seem to have solved the puzzle of LK-99. Scientific detective work has unearthed evidence that the material is not a superconductor, and clarified its actual properties. Nature: The conclusion dashes hopes that LK-99 -- a compound of copper, lead, phosphorus and oxygen -- marked the discovery of the first superconductor that works at room temperature and ambient pressure. Instead, studies have shown that impurities in the material -- in particular, copper sulfide -- were responsible for the sharp drops in electrical resistivity and partial levitation over a magnet, which looked similar to properties exhibited by superconductors. "I think things are pretty decisively settled at this point," says Inna Vishik, a condensed-matter experimentalist at the University of California, Davis.

The LK-99 saga began in late July, when a team led by Sukbae Lee and Ji-Hoon Kim at the Quantum Energy Research Centre, a start-up firm in Seoul, published preprints claiming that LK-99 is a superconductor at normal pressure and temperatures up to at least 127C (400 kelvin). All previously confirmed superconductors function only at extreme temperatures and pressures. The extraordinary claim quickly grabbed the attention of the science-interested public and researchers, some of whom tried to replicate LK-99. Initial attempts did not see signs of room-temperature superconductivity, but were not conclusive. Now, after dozens of replication efforts, many experts are confidently saying that the evidence shows LK-99 is not a room-temperature superconductor. The South Korean team based its claim on two of LK-99's properties: levitation above a magnet and abrupt drops in resistivity. But separate teams in Beijing, at Peking University and the Chinese Academy of Sciences (CAS), found mundane explanations for these phenomena.

Another study, by US and European researchers, combined experimental and theoretical evidence to demonstrate how LK-99's structure made superconductivity infeasible. And other experimenters synthesized and studied pure samples of LK-99, erasing doubts about the material's structure and confirming that it is not a superconductor, but an insulator. The only further confirmation would come from the Korean team sharing their samples, says Michael Fuhrer, a physicist at Monash University in Melbourne, Australia. "The burden's on them to convince everybody else," he says. Perhaps the most striking evidence for LK-99's superconductivity was a video taken by the Korean team that showed a coin-shaped sample of silvery material wobbling over a magnet. The team said the sample was levitating because of the Meissner effect -- a hallmark of superconductivity in which a material expels magnetic fields. Multiple unverified videos of LK-99 levitating subsequently circulated on social media, but none of the researchers who initially tried to replicate the findings observed any levitation.

Space

US Space Force Creates First Unit Dedicated To Targeting Adversary Satellites (space.com) 57

The United States Space Force has activated its first and only unit dedicated to targeting other nations' satellites and the ground stations that support them. Space.com reports: The 75th Intelligence, Surveillance and Reconnaissance Squadron (ISRS) was activated on Aug. 11 at Peterson Space Force Base in Colorado. This unit is part of Space Delta 7, an element of the U.S. Space Force tasked with providing intelligence on adversary space capabilities. It'll do things like analyze the capabilities of potential targets, locate and track these targets as well as participate in "target engagement," which presumably refers to destroying or disrupting adversary satellites, the ground stations that support them and transmissions sent between the two.

Master Sgt. Desiree Cabrera, 75th ISRS operations superintendent, said the new unit will revolutionize the targeting capabilities of not just the Space Force, but also the entire U.S. military: "Not only are we standing up the sole targeting squadron in the U.S. Space Force, we are changing the way targeting is done across the joint community when it comes to space and electromagnetic warfare." The 75th ISRS will also analyze adversary space capabilities including "counterspace force threats," according to the Space Force's statement. Counterspace forces refer to adversary systems aimed at preventing the U.S. from using its own satellites during a conflict.

Science

Scientists Recreate Pink Floyd Song By Reading Brain Signals of Listeners (nytimes.com) 28

An anonymous reader quotes a report from the New York Times: Scientists have trained a computer to analyze the brain activity of someone listening to music and, based only on those neuronal patterns, recreate the song. The research, published on Tuesday, produced a recognizable, if muffled version of Pink Floyd's 1979 song, "Another Brick in the Wall (Part 1)." [...] To collect the data for the study, the researchers recorded from the brains of 29 epilepsy patients at Albany Medical Center in New York State from 2009 to 2015. As part of their epilepsy treatment, the patients had a net of nail-like electrodes implanted in their brains. This created a rare opportunity for the neuroscientists to record from their brain activity while they listened to music. The team chose the Pink Floyd song partly because older patients liked it. "If they said, 'I can't listen to this garbage,'" then the data would have been terrible, Dr. Schalk said. Plus, the song features 41 seconds of lyrics and two-and-a-half minutes of moody instrumentals, a combination that was useful for teasing out how the brain processes words versus melody.

Robert Knight, a neuroscientist at the University of California, Berkeley, and the leader of the team, asked one of his postdoctoral fellows, Ludovic Bellier, to try to use the data set to reconstruct the music "because he was in a band," Dr. Knight said. The lab had already done similar work reconstructing words. By analyzing data from every patient, Dr. Bellier identified what parts of the brain lit up during the song and what frequencies these areas were reacting to. Much like how the resolution of an image depends on its number of pixels, the quality of an audio recording depends on the number of frequencies it can represent. To legibly reconstruct "Another Brick in the Wall," the researchers used 128 frequency bands. That meant training 128 computer models, which collectively brought the song into focus. The researchers then ran the output from four individual brains through the model. The resulting recreations were all recognizably the Pink Floyd song but had noticeable differences. Patient electrode placement probably explains most of the variance, the researchers said, but personal characteristics, like whether a person was a musician, also matter.

The data captured fine-grained patterns from individual clusters of brain cells. But the approach was also limited: Scientists could see brain activity only where doctors had placed electrodes to search for seizures. That's part of why the recreated songs sound like they are being played underwater. [...] The researchers also found a spot in the brain's temporal lobe that reacted when volunteers heard the 16th notes of the song's guitar groove. They proposed that this particular area might be involved in our perception of rhythm. The findings offer a first step toward creating more expressive devices to assist people who can't speak. Over the past few years, scientists have made major breakthroughs in extracting words from the electrical signals produced by the brains of people with muscle paralysis when they attempt to speak.

Medicine

NYU Surgeons Claim Advance In Transplant of Pig Kidney To a Human 88

A genetically altered pig kidney transplanted into a brain-dead man has continued to function for 32 days, an advance toward the possible use of animal organs in humans, surgeons at NYU Langone Health said Wednesday. The Washington Post reports: The kidney was not rejected in the minutes after it was transplanted -- a problem in xenotransplantation, the use of organs from a different species. It began producing urine and took over the functions of a human kidney such as filtering toxins, the physicians said at a news conference. Also Wednesday, researchers at the University of Alabama at Birmingham Heersink School of Medicine published a similar case study, of a brain-dead patient who received two pig kidneys that underwent 10 gene alterations earlier this year. The kidneys were not rejected and continued to function for seven days. The results were peer-reviewed and published in the journal JAMA Surgery.

In the NYU Langone transplant, the specially bred pig from which the kidney was procured required just one genetic alteration, to remove a protein that human immune systems attack shortly after surgery. Surgeons also implanted the pig's thymus gland, which helps train the immune system, by sewing it under the outer layer of the kidney, and used immunosuppressive drugs to prevent rejection later on. Managing the condition of the brain-dead man, who on Wednesday still had a heart beat and was breathing with the aid of a ventilator, for an extended period of time also requires extensive efforts by critical care personnel. But the work has revealed information about longer-term use of animal organs, the doctors said. The researchers expect to follow the patient for another month.

With the results released Wednesday, both Montgomery and Locke said they can envision moving toward the early stage of clinical trials to identify the safety of transplanting pig kidneys into live humans. [...] The genetic alteration in the NYU Langone study knocked out a carbohydrate molecule known as Alpha-gal, for short. Humans do not produce the substance and create high levels of antibodies against it, which has in the past proven a formidable obstacle to xenotransplantation. "Now that it can be completely removed from the pig, that allows us to move forward," Montgomery said. Still, the team said, pigs have 1,000 proteins that humans don't, and it can take 10 to 14 days to see how a person's immune system reacts to them. Getting beyond that stage with this patient at NYU Langone is a first sign that long-term viability of the organ and patient is possible, they said.
United States

The US Is Turning Away From Its Biggest Scientific Partner at a Precarious Time (wsj.com) 131

One of the most productive scientific collaborations of the 21st century is pulling apart, as deteriorating relations between the U.S. and China lead researchers to sever ties. From a report: The decoupling, which began in recent years with investigations into Chinese researchers in the U.S., has accelerated as tensions have risen between the superpowers. Now some U.S. lawmakers are pushing to let a landmark agreement to cooperate on science and technology, signed in 1979 and renewed routinely since, expire this month. China has built itself into a powerful engine of scientific discovery in recent decades, partly with American help, and many in Washington fear that China could gain a security and military advantage unless the U.S. takes decisive steps to cut off cooperation in scientific research.

Many scientists warn, however, that Washington would be severing ties as China is making its greatest contributions to scientific advancements, and cutting it off risks slowing American progress in critical areas such as biotechnology, clean energy and telecommunications. While the U.S. remains the world's pre-eminent science power, fundamental scientific research has grown borderless in the era of globalization, much as business has. More than 40% of America's scientific production -- measured by the number of high-quality papers that U.S.-based scientists produce -- involves cooperation with researchers abroad, according to Clarivate, a London-based data firm that tracks global scientific research. China and the U.S. are each other's No. 1 partner in producing scientific research, with collaborative research between the two consistently among the most-cited papers across fields, according to an analysis of Clarivate's data by Caroline Wagner, a professor of public policy at Ohio State University.

Communications

China Launches First Geosynchronous Orbit Radar Satellite (spacenews.com) 38

China launched what is thought to be the world's first geosynchronous orbit synthetic aperture radar satellite on Saturday. SpaceNews reports: A Long March 3B rocket lifted off from Xichang Satellite Launch Center in southwest China at 1:36 p.m. Eastern (1736 UTC) Aug. 12. The Land Exploration-4 01 (Ludi Tance-4 (01)) satellite successfully entered geosynchronous transfer orbit, the China Aerospace Science and Technology Corp., (CASC) announced within an hour of liftoff. Few details of the satellite were provided by CASC. However the group's "blue book" outlining plans for 2023 released in January noted the launch of a "high-orbit 20-meter [resolution] SAR satellite."

The L-band synthetic aperture radar (SAR) satellite will provide all-day, all-weather observation of China and surrounding areas, boosting the country's disaster prevention, reduction, and relief capabilities. The land observation satellite series and "high-orbit SAR technology" are listed in the country's Medium and Long Term Development Plan for Civilian Space Infrastructure (2015-2025). The plan includes establishing high and medium resolution optical and synthetic aperture radar constellations for a range of land, marine and atmospheric monitoring. The series is separate from the China High-resolution Earth Observation System (CHEOS), which consists of Gaofen ("high resolution") satellites. China's Gaofen-4 satellite is a GEO optical satellite. SAR at GEO, while providing much lower resolution than satellites in low Earth orbit, can provide constant coverage and imagery despite cloud cover.

It is not yet known what orbital scheme the Land Exploration-4 (01) satellite will enter. An inclined GEO orbit would produce a "figure eight" ground track over the area of intended coverage. Chinese academics from the Beijing Institute of Technology have produced a study of various schemes, while others have published research into modified signal models for GEO SAR. The (01) designation suggests China could launch other SAR satellites into geosynchronous orbits. The satellite was developed by the China Academy of Spacecraft Technology (CAST.)

Medicine

Amazon Pharmacy Automates Discounts To Help Insulin Patients Get Pledged Prices (reuters.com) 41

Amazon said on Tuesday its online pharmacy will automatically apply manufacturer-sponsored coupons to more than 15 insulin and diabetes medicines to help patients access discounts pledged by the drug industry. From a report: With the new program, patients using Amazon Pharmacy will no longer have to search for and manually enter coupons from the three largest insulin makers, Novo Nordisk, Eli Lilly, and Sanofi, to lower the cost of their insulin to as little as $35 for a month's supply, the company said.

Novo, Lilly and Sanofi announced in March that they would slash their insulin prices by at least 70% by or in 2024, but a report from Senator Elizabeth Warren released last month said some patients were finding it difficult to get already discounted generic insulin from pharmacies at the promised lower price. Despite Lilly lowering the list price of its Insulin Lispro to $25 per vial in May, patients were still being quoted as much as $330 for the medicine, were not being told about cheaper options when they went to pharmacies, and were finding it difficult to use Lilly's savings program, Warren's report found. Vin Gupta, Amazon Pharmacy's Chief Medical Officer, said the report highlighted the need to make it easier for patients to get their insulin at the lowest possible prices.

Space

Could Supermassive Black Holes Explain Our Universe's Gravitational-Wave 'Hum'? (space.com) 19

"Earlier this year, after 15 years of searching, scientists finally heard the background hum of low-frequency gravitational waves that fill our universe," writes Space.com.

"Now, the hard work of searching for the source of these ripples in spacetime can begin." Currently, the primary suspects in this case are pairings of supermassive black holes with masses millions, or even billions, of times that of the sun. However, that doesn't mean that there isn't room for a few unusual suspects, which could potentially point us toward new physics....

[G]ravitational waves detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) express wavelengths that are thousands of miles (or km) in length and hold frequencies of milliseconds to seconds. The new gravitational waves detected by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), by contrast, have wavelengths on a scale of trillions of miles (or km). This is similar to the distance between the sun and its neighboring star, Proxima Centauri, a staggering 20 light-years in length. Plus, NANOGrav gravitational wavelengths have frequencies on scales of years instead of mere seconds. Practically, what this means is scientists need to build over 15 years of NANOGrav data to confirm a low-frequency gravitational wave detection.

But, when it happens, it's worth the wait. That's because these results have the capacity to point us toward new information about our universe... "The detection of low-frequency gravitational waves means they're from very different sources to the LIGO and Virgo sources, which are stellar mass black holes and neutron star mergers," Scott Ransom, a National Radio Astronomy Observatory astronomer and former chair of NANOGrav, told Space.com... Ransom is part of a collaboration of researchers that believe low-frequency gravitational waves, including those detected by NANOGrav, may originate from a pretty incredible source. They could come from, the team argues, hundreds of thousands of supermassive black hole pairings that, over the 13.8-billion-year course of cosmic history, came close enough together that they've merged...

"For many decades, theorists have hypothesized that supermassive black hole binaries should produce a signal with characteristics just like what NANOGrav and other pulsar timing arrays are seeing," Luke Zoltan Kelly, a Northwestern University theoretical astrophysicist and NANOGrav researcher, told Space.com. "For most of the community, supermassive black hole binaries are a natural best guess for what's producing the gravitational wave background...." Zoltan Kelley pointed out to Space.com that besides binaries, there are a number of new models in cosmology and in particle physics that, under the right circumstances, could also produce a similar gravitational wave background to that detected by NANOGrav. For example, axion or 'fuzzy' dark matter, cosmic strings, inflationary phase transitions, and many others," the Northwestern astrophysicist said.

"What's really exciting about these possibilities is that each of these models is an attempt to explain some of the biggest current mysteries of our universe."

Science

Why Was Silicon Valley So Obsessed with LK-99 Superconductor Claims? (msn.com) 78

What to make of the news that early research appears unable to duplicate the much-ballyhooed claims for the LK99 superconductor?

"The episode revealed the intense appetite in Silicon Valley for finding the next big thing," argues the Washington Post, "after years of hand-wringing that the tech world has lost its ability to come up with big, world-changing innovations, instead channeling all its money and energy into building new variations of social media apps and business software..." [M]any tech leaders are nervous that the current focus on consumer and business software has led to stagnation. A decade ago, investors prophesied that self-driving cars would take over the roads by the mid-2020s — but they are still firmly in the testing phase, despite billions of dollars of investment. Cryptocurrencies and blockchain technology have had multiple hype cycles of their own, but have yet to fundamentally change any industry, besides crime and money laundering. Tech meant to help mitigate climate change, like carbon capture and storage, has lagged without major advances in years. Meanwhile, Big Tech companies used their huge cash hoards to snap up smaller competitors, with antitrust regulators only recently beginning to clamp down on consolidation. Over the last year, as higher interest rates have cut into the amount of venture capital and slowing growth has caused companies to pull back spending, a massive wave of layoffs has swept the industry, and companies such as Google that previously said they'd invest some of their profits in big, risky ideas have turned away from such "moonshots..."

Room-temperature superconductors would be especially relevant to the tech industry right now, which is busy burning billions of dollars on new computer chips and the energy costs to run them to train the AI models behind tools like ChatGPT and Google's Bard. For years, computer chips have gotten smaller and more efficient, but that progress has run up against the limits of the physical world as transistors get so small some are now just one atom thick.

Science

Common Alzheimer's Disease Gene May Have Helped Our Ancestors Have More Kids (science.org) 40

Science magazine reports: Roughly one in five people are born with at least one copy of a gene variant called APOE4 that makes them more prone to heart disease and Alzheimer's disease in old age. That the variant is so common poses an evolutionary mystery: If it decreases our fitness, why hasn't APOE4 been purged from the human population over time?

Now, a study of nearly 800 women in a traditional society in the Amazon finds that those with the disease-promoting variant had slightly more children. Such a fertility benefit may have allowed the gene to persist during human evolution despite its harmful effects for older people today...

The Tsimané data also allowed the team to home in on how APOE4 may boost fertility: Women carrying it were slightly heavier that those without it, started bearing children about 1 year earlier, and had their next child a few months sooner. That fits with being more resistant to parasites, says siological anthropologist Benjamin Trumble . "Being in a better immune state means that you can then devote more calories towards growing faster, and then you're able to reproduce faster."

Thanks to Slashdot reader sciencehabit for sharing the article.
Space

How to Turn an Asteroid into a Space Habitat (Using Self-Replicating Spider Robots) (sciencealert.com) 65

A retired Technical Fellow from Rockwell Collins "released a 65-page paper that details an easy-to-understand, relatively inexpensive, and feasible plan to turn an asteroid into a space habitat," reports Universe Today (in an article republished at Science Alert): Dr. David W. Jensen breaks the discussion into three main categories — asteroid selection, habitat style selection, and mission strategy to get there (i.e., what robots to use)... He eventually settled on a torus as the ideal habitat type and then dives into calculations about the overall station mass, how to support the inner wall with massive columns, and how to allocate floor space.

All important, but how exactly would we build such a massive behemoth? Self-replicating robots are Dr. Jensen's answer. The report's third section details a plan to utilize spider robots and a base station that can replicate themselves. He stresses the importance of only sending the most advanced technical components from Earth and using materials on the asteroid itself to build everything else, from rock grinders to solar panels...

With admittedly "back-of-the-envelope" calculations, Dr. Jensen estimates that the program would cost only $4.1 billion. That is far less than the $93 billion NASA plans to spend on the Apollo program. And the result would be a space habitat that provides 1 billion square meters of land that didn't exist before. That's a total cost of $4.10 per square meter to build land — in space. Possibly even more impressive is the timeline — Dr. Jensen estimates that the entire construction project could be done in as little as 12 years. However, it will still take longer to fill the habitat with air and water and start regulating its temperature.

Medicine

New Nanophotonic Sample-Testing Chip Could Detect Multiple Viruses or Cancers In Minutes (science.org) 8

Science magazine reports: Researchers have shown how to conduct thousands of rapid molecular screenings simultaneously, using light to identify target molecules snared on top of an array of tiny silicon blocks. In theory, the tool could be used to spot 160,000 different molecules in a single square centimeter of space. Developed to spot gene fragments from the SARS-CoV-2 virus and other infectious organisms, the technology should also be able to identify protein markers of cancer and small molecules flagging toxic threats in the environment...

"[P]revious sensors have not been able to detect a wide range of target molecules," from very low to very high abundance, says Jennifer Dionne, an applied physicist at Stanford University. In hopes of getting around these problems, Dionne and her colleagues turned to an optical detection approach that relies on metasurfaces, arrays of tiny silicon boxes — each roughly 500 nanometers high, 600 nanometers long, and 160 nanometers wide — that focus near-infrared light on their top surface. This focusing makes it easy for a simple optical microscope to detect the shift in the wavelength of light coming from each silicon block, which varies depending on what molecules sit on top...

[T]he technique could allow doctors to detect viral infections without first having to amplify the genetic material from a patient, Dionne says. Perhaps as important, she notes, an array can be designed to reveal how much target DNA has bound, making it possible to detect in minutes not just whether a particular virus is present, but how intense the infection is. Such information could help doctors tailor their treatments. Current tests can also do this, but they normally take several hours to amplify the genetic material and quantify the results.

Dionne and her colleagues have formed a company called Pumpkinseed Bio to commercialize their new detectors, specifically aimed at detecting minute levels of proteins and other molecules that can't readily be amplified to make them easier to detect. And because only a small number of silicon blocks would be needed to spot individual target molecules, researchers should be able to craft arrays to track a multitude of disease biomarkers simultaneously. "We hope to look at many disease states at the same time," says Jack Hu, a former graduate student in Dionne's lab and head of the new startup. "That's the vision."

Thanks to Slashdot reader sciencehabit for sharing the article.

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