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Space

'Life May Have Everything It Needs to Exist on Saturn's Moon Enceladus' (nasa.gov) 27

An anonymous reader shared this report from CNN: Scientists have long viewed Saturn's moon Enceladus, which harbors an ocean beneath its thick, icy shell, as one of the best places to search for life beyond Earth. Now, a new analysis of data collected by NASA's Cassini mission, which orbited Saturn and its moons between 2004 and 2017, has uncovered intriguing evidence that further supports the idea of Enceladus as a habitable ocean world.

Enceladus initially captured the attention of scientists in 2005 because plumes of ice grains and water vapor were observed rising through cracks in the moon's ice shell and releasing into space. The spacecraft flew through the plumes and "sampled" them, with data suggesting the presence of organic compounds within the plumes, some of which are key for life. The latest data analysis of Cassini's flybys of Enceladus revealed the detection of a molecule called hydrogen cyanide that's toxic to humans but crucial to processes driving the origin of life. What's more, the team also found evidence to support that Enceladus' ocean has organic compounds that provide a source of chemical energy that could potentially be used as powerful fuel for any form of life...

The combination of these elements together suggested a process called methanogenesis, or the metabolic creation of methane, may be at play on Enceladus. Scientists suspect methanogenesis may have also played out on early Earth, contributing to the origin of life. But the new research indicates more varied and powerful chemical energy sources are occurring within Enceladus' ocean... Now, the study authors want to investigate how diluted the organic compounds are within the subsurface ocean because the dilution of these compounds could determine whether Enceladus could support life. In the future, astronomers hope to send a dedicated mission to investigate Enceladus, which could provide a definitive answer as to whether life exists in the ocean world.

"Our work provides further evidence that Enceladus is host to some of the most important molecules for both creating the building blocks of life and for sustaining that life through metabolic reactions," accoding to one of the study's lead authors.

"Not only does Enceladus seem to meet the basic requirements for habitability, we now have an idea about how complex biomolecules could form there, and what sort of chemical pathways might be involved."
Medicine

Seeking 'Superbug' Antibiotics, Scientists Use AI to Synthesize Molecules from Neanderthals (cnn.com) 12

An anonymous reader shared this report from CNN: The quest for new antibiotics is going back to the Stone Age. The urgency to identify possible candidates has never been greater as the global population faces nearly 5 million deaths every year that are associated with microbial resistance, according to the World Health Organization. A research team led by bioengineering pioneer César de la Fuente is using artificial intelligence-based computational methods to mine genetic information from extinct human relatives such as Neanderthals and long-gone ice age creatures such as the woolly mammoth and giant sloth. The scientists say some of these small protein, or peptide, molecules they have identified have bacteria-fighting powers that may inspire new drugs to fight infections in humans. The innovative work also opens up a completely new way to think about drug discovery.

"It has enabled us to uncover new sequences, new types of molecules that we have not previously found in living organisms, expanding the way we think about molecular diversity," said de la Fuente, Presidential Assistant Professor at the University of Pennsylvania, where he heads the machine biology group. "Bacteria from today have never faced those molecules so they may give us a better opportunity at targeting the pathogens that are problematic today...." The idea to look at extinct molecules came up during a lab brainstorm when the blockbuster movie "Jurassic Park" was mentioned. "The notion (in the film) was to bring back entire organisms, and obviously, they had a lot of issues," De la Fuente said. His team started thinking about a more feasible idea: "Why not bring back molecules from the past?" Advances in the recovery of ancient DNA from fossils mean that detailed libraries of genetic information about extinct human relatives and long-lost animals are now publicly available...

In research expected to publish next year, de la Fuente and his colleagues have developed a new deep-learning model to explore what he describes as the "extinctome" — the protein sequences of 208 extinct organisms for which detailed genetic information is available. The team found more than 11,000 previously unknown potential antimicrobial peptides unique to extinct organisms and synthesized promising candidates... He said that the peptides they discovered displayed "excellent anti-infective activity" in mice.

"Molecular de-extinction offers a unique opportunity to combat antibiotic resistance by resurrecting and tapping into the power of molecules from the past," he said.

NASA

Asteroid Pieces Brought to Earth May Offer a Clue to Life's Origin (msn.com) 26

In 2020 a NASA spacecraft visited the asteroid Bennu. In October it returned to earth with a sample. Monday scientists got their first data about it at a meeting of the American Geophysical Union — which is a truly big deal.

"Before Earth had biology, it had chemistry," writes the Washington Post. "How the one followed from the other — how a bunch of boring molecules transformed themselves into this special thing we call life — is arguably the greatest unknown in science." The mission's top scientist, Dante Lauretta... showed slides with a long list of intriguing molecules, including carbon-based organics, in the grains and pebbles retrieved from Bennu. They will shine light on the molecular building blocks of the solar system and "maybe — still early phase — maybe insights into the origin of life." This analysis has only just started. The team has not yet released a formal scientific paper. In his lecture, Lauretta cited one interesting triangular, light-colored stone, which he said contained something he'd never seen before in a meteorite. "It's a head-scratcher right now. What is this material?" he said.

In an interview after the lecture, Lauretta said almost 5 percent of the sample is carbon. "That is a very carbon-rich sample — the richest we have in all our extraterrestrial material. ... We're still unraveling the complex organic chemistry, but it looks promising to really understand: Did these carbon-rich asteroids deliver fundamental molecules that may have gone on to contribute to the origin of life...?"

This space dirt has astrobiological import, though. By looking at prebiotic chemistry on Bennu, scientists will have a better idea what they are looking at if and when they find suspicious molecules elsewhere in the solar system, such as on Mars, Jupiter's moon Europa or Saturn's moon Enceladus. "This is almost the perfect laboratory control from non-biological chemistry," Glavin said. "This better prepares us for our search for life on Mars, or Europa or Enceladus — places that might have had life at one point."

Space.com quotes Lauretta as saying "We definitely have hydrated, organic-rich remnants from the early solar system, which is exactly what we were hoping when we first conceived this mission almost 20 years ago."
Science

The Biggest Problem With Lab-Grown Chicken Is Growing the Chicken (bloomberg.com) 74

Ten years ago, a Dutch scientist unveiled a $330,000 lab-grown hamburger made from cow cells grown in petri dishes. It took six weeks to culture the patty. A chef cooked it onstage as journalists watched. Reactions ranged from "unpleasant" to "beeflike." The scientist expected supermarket sales in a decade. His company and others have since raised over $2 billion but have little to show, only recently making one pound of chicken monthly. Despite bold promises of mass production, low emissions, and better nutrition, commercial viability remains elusive. Bloomberg Business: The company [Upside Foods], in a letter from its attorney to Bloomberg Businessweek, says plans for scaling up have been an evolution saddled with "realities and complexities of doing something that has never been done before. Innovation rarely happens in a straight and continuous line."

The dream is moist, meaty flesh self-multiplying ad infinitum in high-tech, stainless steel cell-growing chambers. But according to internal company documentation and eight former employees, most of whom requested anonymity because they don't have permission to discuss confidential information, Upside at the moment is actually growing just minuscule numbers of chicken skin-type cells in small plastic bottles, then scraping them out gram by gram to compress and mold them into a single forkful of flesh. This labor-intensive chicken has higher levels of cholesterol and lead than the real thing, publicly available company documentation shows. Even if that sounds remotely desirable, some scientists say the whole energy-intensive endeavor may actually be worse for the environment, especially with chicken, which has the smallest carbon footprint of anything at the local butcher. All of which points to this question: Why exactly are we chasing lab-grown chicken?[...]

Earth

Stop Planting Trees, Says Guy Who Inspired World to Plant a Trillion Trees (wired.com) 155

In a cavernous theater lit up with the green shapes of camels and palms at COP28 in Dubai, ecologist Thomas Crowther, former chief scientific adviser for the United Nations' Trillion Trees Campaign, was doing something he never would have expected a few years ago: begging environmental ministers to stop planting so many trees. From a report: Mass plantations are not the environmental solution they're purported to be, Crowther argued when he took the floor on December 9 for one of the summit's "Nature Day" events. The potential of newly created forests to draw down carbon is often overstated. They can be harmful to biodiversity. Above all, they are really damaging when used, as they often are, as avoidance offsets-- "as an excuse to avoid cutting emissions," Crowther said.

The popularity of planting new trees is a problem -- at least partly -- of Crowther's own making. In 2019, his lab at ETH Zurich found that the Earth had room for an additional 1.2 trillion trees, which, the lab's research suggested, could suck down as much as two-thirds of the carbon that humans have historically emitted into the atmosphere. "This highlights global tree restoration as our most effective climate change solution to date," the study said. Crowther subsequently gave dozens of interviews to that effect. This seemingly easy climate solution sparked a tree-planting craze by companies and leaders eager to burnish their green credentials without actually cutting their emissions, from Shell to Donald Trump. It also provoked a squall of criticism from scientists, who argued that the Crowther study had vastly overestimated the land suitable for forest restoration and the amount of carbon it could draw down. (The study authors later corrected the paper to say tree restoration was only "one of the most effective" solutions, and could suck down at most one-third of the atmospheric carbon, with large uncertainties.)

Crowther, who says his message was misinterpreted, put out a more nuanced paper last month, which shows that preserving existing forests can have a greater climate impact than planting trees. He then brought the results to COP28 to "kill greenwashing" of the kind that his previous study seemed to encourage -- that is, using unreliable evidence on the benefits of planting trees as an excuse to keep on emitting carbon. "Killing greenwashing doesn't mean stop investing in nature," he says. "It means doing it right. It means distributing wealth to the Indigenous populations and farmers and communities who are living with biodiversity."

Space

Jeff Bezos Says Blue Origin Needs To Be 'Much Faster' 127

In an interview with Lex Fridman, Jeff Bezos candidly acknowledged Blue Origin's slow progress (compared to SpaceX). From a report: "Blue Origin needs to be much faster, and it's one of the reasons that I left my role as the CEO of Amazon a couple of years ago," he said. "I wanted to come in, and Blue Origin needs me right now. Adding some energy, some sense of urgency. We need to move much faster. And we're going to."

How is Blue Origin going to speed up?

"We're going to become the world's most decisive company across any industry," he said. "We're going to get really good at taking appropriate technology risks, making those decisions quickly. You know, being bold on those things. And having the right culture that supports that. You need people to be ambitious, technically ambitious. If there are five ways to do something, we'll study them, but let's go through them very quickly and make a decision. We can always change our mind."
Medicine

Scientists Pinpoint Cause of Morning Sickness To Hormone Made By Fetus 145

Scientists have pinpointed the cause of nausea and vomiting in pregnancy, "finding that the severity of illness is influenced by how much of a hormone called GDF15 the growing fetus makes," reports Science Magazine. The findings have been published in the journal Nature. From the report: GDF15 is present in the blood of nonpregnant people and is known to be associated with nausea; it's also been tested as a weight loss aid because of its tendency to suppress appetite. Levels of the hormone rise sharply in early pregnancy and increase throughout gestation. Pregnant people with higher GDF15 concentrations have been documented as having a higher risk of vomiting and nausea. Some researchers suggest the hormone-caused aversion to some smells and tastes might encourage an expectant parent to avoid foods potentially dangerous to the fetus.

To find out more about GDF15 changes during pregnancy, University of Cambridge physician-scientist Stephen O'Rahilly and colleagues studied half a dozen pregnant people who were known from previous genetic screening to produce a slightly different version of the GDF15 protein from their fetuses. Researchers could take advantage of that difference to trace whether GDF15 in the parent's blood originated in the parental or fetal genome: Almost all of it came from the fetus, O'Rahilly says. The team also took a closer look at the link between GDF15 levels and pregnancy sickness. Consistent with previous research, questionnaires from more than 300 participants showed that people who reported vomiting and nausea had significantly higher levels of circulating GDF15 on average than people without these symptoms. The researchers also found elevated levels of GDF15 in an analysis of more than 50 women hospitalized with hyperemesis gravidarum.

Still, hormone levels alone couldn't explain the difference in sickness severity. "There was a big overlap" in GDF15 levels between the groups, O'Rahilly says. He and co-author Marlena Fejzo, a researcher at the University of Southern California, suspected that people's sensitivity to GDF15 might also play a role. (Fejzo began to study the condition after her own pregnancy loss following hyperemesis gravidarum.) To test the idea, the researchers studied 10 nonpregnant people with a rare genetic variant known to carry a heightened risk of hyperemesis gravidarum. These people had reduced GDF15 levels in their blood, hinting that naturally low levels of the hormone might predispose someone to sickness during pregnancy. The researchers found the opposite when they asked 20 pregnant people with beta thalassemia, a blood disorder associated with high GDF15 levels, about their pregnancy symptoms: Just 5% of this group reported nausea or vomiting. O'Rahilly's lab found a similar pattern in animal experiments.
Communications

NASA's Voyager 1 Probe In Interstellar Space Can't Phone Home (space.com) 34

NASA's Voyager 1 spacecraft is, once again, having trouble transmitting any scientific or systems data back to Earth. "The 46-year-old spacecraft is capable of receiving commands, but a problem seems to have arisen with the probe's computers," reports Space.com. Slashdot readers quonset and ArchieBunker shared the news. From the report: Voyager 1's flight data system (FDS), which collects onboard engineering information and data from the spacecraft's scientific instruments, is no longer communicating as expected with the probe's telecommunications unit (TMU), according to a NASA blog post on Dec. 12. When functioning properly, the FDS compiles the spacecraft's info into a data package, which is then transmitted back to Earth using the TMU. Lately, that data package has been "stuck," the blog post said, "transmitting a repeating pattern of ones and zeros." Voyager's engineering team traced the problem back to the FDS, but it could be weeks before a solution is found. In May 2022, Voyager 1 experienced transmitting issues for several months before a workaround was found. Meanwhile, Voyager 2 experienced an unplanned "communications pause" earlier this year after a routine sequence of commands triggered a 2-degree change in the spacecraft's antenna orientation. This prevented it from receiving commands or transmitting data back to Earth until NASA fixed the issue a week later.
AI

Google DeepMind Uses LLM To Solve Unsolvable Math Problem (technologyreview.com) 48

An anonymous reader quotes a report from MIT Technology Review: In a paper published in Nature today, the researchers say it is the first time a large language model has been used to discover a solution to a long-standing scientific puzzle -- producing verifiable and valuable new information that did not previously exist. "It's not in the training data -- it wasn't even known," says coauthor Pushmeet Kohli, vice president of research at Google DeepMind. Large language models have a reputation for making things up, not for providing new facts. Google DeepMind's new tool, called FunSearch, could change that. It shows that they can indeed make discoveries -- if they are coaxed just so, and if you throw out the majority of what they come up with.

FunSearch (so called because it searches for mathematical functions, not because it's fun) continues a streak of discoveries in fundamental math and computer science that DeepMind has made using AI. First Alpha Tensor found a way to speed up a calculation at the heart of many different kinds of code, beating a 50-year record. Then AlphaDev found ways to make key algorithms used trillions of times a day run faster. Yet those tools did not use large language models. Built on top of DeepMind's game-playing AI AlphaZero, both solved math problems by treating them as if they were puzzles in Go or chess. The trouble is that they are stuck in their lanes, says Bernardino Romera-Paredes, a researcher at the company who worked on both AlphaTensor and FunSearch: "AlphaTensor is great at matrix multiplication, but basically nothing else." FunSearch takes a different tack. It combines a large language model called Codey, a version of Google's PaLM 2 that isfine-tuned on computer code, with other systems that reject incorrect or nonsensical answers and plug good ones back in.

The researchers started by sketching out the problem they wanted to solve in Python, a popular programming language. But they left out the lines in the program that would specify how to solve it. That is where FunSearch comes in. It gets Codey to fill in the blanks -- in effect, to suggest code that will solve the problem. A second algorithm then checks and scores what Codey comes up with. The best suggestions -- even if not yet correct -- are saved and given back to Codey, which tries to complete the program again. After a couple of million suggestions and a few dozen repetitions of the overall process -- which took a few days -- FunSearch was able to come up with code that produced a correct and previously unknown solution to the cap set problem, which involves finding the largest size of a certain type of set. Imagine plotting dots on graph paper. [...] To test its versatility, the researchers used FunSearch to approach another hard problem in math: the bin packing problem, which involves trying to pack items into as few bins as possible. This is important for a range of applications in computer science, from data center management to e-commerce. FunSearch came up with a way to solve it that's faster than human-devised ones.

Music

The Excitement of 70,000 Swifties Can Shake the Earth (economist.com) 46

The Economist reports: "Shake, shake, shake, shake," Taylor Swift sings from the stage of Lumen Field in Seattle at 10.35 in the evening on July 22nd. The fans respond, enthusiastically; the stadium duly shakes; a nearby seismometer takes note. To pop aficionados "Shake it off" is an empowering up-tempo anthem played at 160 beats per minute. To the Pacific Northwest Seismic Network, which is designed to monitor earthquakes, it is a 2.6 hertz signal in which the amplitude of the acceleration was as large as one centimetre per second, per second.

The well-situated seismometer first came to public attention in January 2011, when it recorded the response of fans of the Seattle Seahawks, an American football team, to a magnificent touchdown by Marshawn Lynch, a running back known as "Beast Mode." The "Beast Quake" went down in local sporting history. When Ms Swift came to town for two nights of her Eras tour, Jacqueline Caplan-Auerbach, a geology professor at Western Washington University, used the opportunity to learn more about how events in the stadium shake its surroundings. On December 11th she presented some of her conclusions at the American Geophysical Union's autumn meeting in San Francisco.

[...] Dr Caplan-Auerbach wanted to see whether such resonant amplification might also be at play elsewhere, and to distinguish between the effect of the music itself and the audience's response. Her concert-night data showed two distinct sets of signals, one in higher frequencies (30-80hz), one in lower frequencies (1-8hz). The higher-frequency signals were present during the sound check, when the band were on stage but the stadium empty, and absent during the concerts' "surprise songs," played without the band by Ms Swift alone. The lower frequencies were absent when the audience had yet to arrive. Clearly those higher frequencies were from the music itself.

Space

Are Tiny Black Holes Hiding Within Giant Stars? (science.org) 43

sciencehabit shares a report from Science Magazine: Grunge music: a source of validation for a generation of disaffected youth. And a surprising source of scientific inspiration for Earl Bellinger of the Max Planck Institute for Astrophysics. While listening to Soundgarden's 1994 hit Black Hole Sun 2 years ago, he contemplated a curious question: Might itty-bitty black holes from the dawn of time be lurking in the hearts of giant stars? A new study by Bellinger and colleagues suggests the idea is not so far-fetched. Astronomers could detect these trapped black holes by the vibrations they cause on the star's surface. And if there's enough of them out there, they could function as the mysterious dark matter that holds the universe together.

The researchers found that the black holes would sink to the star's core where hydrogen atoms undergo fusion to produce heat and light. At first, very little would happen. Even a dense stellar core is mostly empty space. The most microscopic of the black holes would have a hard time finding matter to consume and its growth would be extremely slow, Bellinger says. "It could take longer than the lifetime of the universe to eat the star." But larger ones, roughly as massive as the asteroid Ceres or the dwarf planet Pluto, would get bigger on timescales of only a few hundred million years. Material would spiral onto the black hole, forming a disk that would heat up through friction and emit radiation. Once the black hole was about as massive as Earth, it would produce significant amounts of radiation, shining brightly and churning up the star's core like pot of boiling water. "It will become a black hole -- powered object rather than fusion-powered object," says study co-author Matt Caplan, a theoretical physicist at Illinois State University. He and his colleagues have dubbed these entities "Hawking stars."

The European Space Agency's Gaia satellite has spotted about 500 such anomalously cool giant stars, known as red stragglers, Bellinger says. To figure out whether these might actually be hiding a black hole, he says, astronomers could tune in to the particular frequencies at which the stars vibrate. Because a Hawking star would churn throughout its interior, rather than just in the topmost layers like an ordinary red giant, it would be expected to thrum with a particular combination of frequencies. Such waves can be detected in the way the star's light pulses and throbs. Bellinger is applying for funding to study the known red stragglers and see whether any display the characteristic vibrations of a black hole.
The study has been published in The Astrophysical Journal.
Science

Human Brain Cells Hooked Up To a Chip Can Do Speech Recognition (technologyreview.com) 56

An anonymous reader quotes a report from MIT Technology Review: Brain organoids, clumps of human brain cells grown in a dish, can be hooked up to an electronic chip and carry out simple computational tasks, a new study shows. Feng Guo and his team at Indiana University Bloomington generated a brain organoid from stem cells, attached it to a computer chip, and connected their setup, known as Brainoware, to an AI tool. They found that this hybrid system could process, learn, and remember information. It was even able to carry out some rudimentary speech recognition. The work, published today in Nature Electronics, could one day lead to new kinds of bio-computers that are more efficient than conventional computers.

"This is a first demonstration of using brain organoids [for computing]," says Guo. "It's exciting to see the possibilities of organoids for biocomputing in the future." With Brainoware, Guo aimed to use actual brain cells to send and receive information. When the researchers applied electrical stimulation to the hybrid system they'd built, Brainoware responded to those signals, and changes occurred in its neural networks. According to the researchers, this result suggests that the hybrid system did process information, and could perhaps even perform computing tasks without supervision. Guo and his colleagues then attempted to see if Brainoware could perform any useful tasks. In one test, they used Brainoware to try to solve mathematical equations. They also gave it a benchmark test for speech recognition, using 240 audio clips of eight people pronouncing Japanese vowels. The clips were converted into electrical signals and applied to the Brainoware system. This generated signals in the neural networks of the brain organoid, which were then fed into an AI tool for decoding.

The researchers found that the brain organoid -- AI system could decode the signals from the audio recordings, which is a form of speech recognition, says Guo. "But the accuracy was low," he says. Although the system improved with training, reaching an accuracy of about 78%, it was still less accurate than artificial neural networks, according to the study. Lena Smirnova, an assistant professor of public health at Johns Hopkins University, points out that brain organoids do not have the ability to truly hear speech but simply exhibit "a reaction" to pulses of electrical stimulation from the audio clips. And the study did not demonstrate whether Brainoware can process and store information over the long term or learn multiple tasks. Generating brain cell cultures in a lab and maintaining them long enough to perform computations is also a huge undertaking. Still, she adds, "it's a really good demonstration that shows the capabilities of brain organoids."

Medicine

Every Homeopathic Eye Drop Should Be Pulled Off the Market, FDA Says 177

An anonymous reader shares a report: This year has been marked by many terrifying things, but perhaps the most surprising of the 2023 horrors was ... eye drops. The seemingly innocuous teeny squeeze bottle made for alarming headlines numerous times during our current revolution around the sun, with lengthy lists of recalls, startling factory inspections, and ghastly reports of people developing near-untreatable bacterial infections, losing their eyes and vision, and dying.

Recapping this unexpected threat to health, the Food and Drug Administration on Tuesday released an advisory titled "What You Should Know about Eye Drops" in hopes of keeping the dangers of this year from leaking into the next. Among the notable points from the regulator was this stark pronouncement: No one should ever use any homeopathic ophthalmic products, and every single such product should be pulled off the market. The point is unexpected, given that none of the high-profile infections and recalls this year involved homeopathic products. But, it should be welcomed by any advocates of evidence-based medicine.
Space

Scientists Discover Nuclear Fission Amongst the Stars (space.com) 31

For the first time, scientists have discovered nuclear fission occurring amongst the stars, supporting the idea that neutron stars create "superheavy" elements when they collide, which then break down via nuclear fission to birth rare elements. Space.com reports: Nuclear fission is basically the opposite of nuclear fusion. While nuclear fusion refers to the smashing of lighter elements to create heavier elements, nuclear fission is a process that sees energy released when heavy elements split apart to create lighter elements. Nuclear fission is pretty well known, too. It's actually the basis of energy-generating nuclear power plants here on Earth -- however, it had not been seen occurring amongst the stars before now.

The team of researchers led by North Carolina State University scientist Ian Roederer searched data concerning a wide range of elements in stars to discover the first evidence that nuclear fission could therefore be acting when neutron stars merge. These findings could help solve the mystery of where the universe's heavy elements come from. Scientists know that nuclear fusion is not just the primary source of energy for stars, but also the force that forges a variety of elements, the "heaviest" being iron.

The evidence of nuclear fission discovered by [Matthew Mumpower, research co-author and a scientist at Los Alamos National Laboratory] and the team comes in the form of a correlation between "light precision metals," like silver, and "rare earth nuclei," like europium, showing in some stars. When one of these groups of elements goes up, the corresponding elements in the other group also increases, the scientists saw. The team's research also indicates that elements with atomic masses -- counts of protons and neutrons in an atomic nucleus -- greater than 260 may exist around neutron star smashes, even if this existence is brief. This is much heavier than many of the elements at the "heavy end" of the periodic table.
"The only plausible way this can arise among different stars is if there is a consistent process operating during the formation of the heavy elements," Mumpower said. "This is incredibly profound and is the first evidence of fission operating in the cosmos, confirming a theory we proposed several years ago."

"As we've acquired more observations, the cosmos is saying, 'hey, there's a signature here, and it can only come from fission.'"

The research was published in the journal Science.
AI

AI As Good As Doctors At Checking X-Rays 83

A new study from the University of Warwick found that artificial intelligence can analyze X-rays and diagnose medical issues better than doctors. The BBC reports: Software was trained using chest X-rays from more than 1.5m patients, and scanned for 37 possible conditions. It was just as accurate or more accurate than doctors' analysis at the time the image was taken for 35 out of 37 conditions, the University of Warwick said. The AI could reduce doctors' workload and delays in diagnosis, and offer radiologists the "ultimate second opinion," researchers added. The software understood that some abnormalities for which it scanned were more serious than others, and could flag the most urgent to medics, the university said.

To check the results were accurate, more than 1,400 X-rays analysed by the software were cross-examined by senior radiologists. They then compared the diagnoses made by the AI with those made by radiologists at the time. The software, called X-Raydar, removed human error and bias, said lead author, Dr Giovanni Montana, Professor of Data Science at Warwick University. "If a patient is referred for an X-ray with a heart problem, doctors will inevitably focus on the heart over the lungs," he said. "This is totally understandable but runs the risk of undetected problems in other areas".
Cellphones

Transparent Wood Could Soon Find Uses In Smartphone Screens, Insulated Windows (arstechnica.com) 33

An anonymous reader quotes a report from Ars Technica: Thirty years ago, a botanist in Germany had a simple wish: to see the inner workings of woody plants without dissecting them. By bleaching away the pigments in plant cells, Siegfried Fink managed to create transparent wood, and he published his technique in a niche wood technology journal. The 1992 paper remained the last word on see-through wood for more than a decade, until a researcher named Lars Berglund stumbled across it. Berglund was inspired by Fink's discovery, but not for botanical reasons. The materials scientist, who works at KTH Royal Institute of Technology in Sweden, specializes in polymer composites and was interested in creating a more robust alternative to transparent plastic. And he wasn't the only one interested in wood's virtues. Across the ocean, researchers at the University of Maryland were busy on a related goal: harnessing the strength of wood for nontraditional purposes.

Now, after years of experiments, the research of these groups is starting to bear fruit. Transparent wood could soon find uses in super-strong screens for smartphones; in soft, glowing light fixtures; and even as structural features, such as color-changing windows. "I truly believe this material has a promising future," says Qiliang Fu, a wood nanotechnologist at Nanjing Forestry University in China who worked in Berglund's lab as a graduate student. Wood is made up of countless little vertical channels, like a tight bundle of straws bound together with glue. These tube-shaped cells transport water and nutrients throughout a tree, and when the tree is harvested and the moisture evaporates, pockets of air are left behind. To create see-through wood, scientists first need to modify or get rid of the glue, called lignin, that holds the cell bundles together and provides trunks and branches with most of their earthy brown hues. After bleaching lignin's color away or otherwise removing it, a milky-white skeleton of hollow cells remains. This skeleton is still opaque, because the cell walls bend light to a different degree than the air in the cell pockets does -- a value called a refractive index. Filling the air pockets with a substance like epoxy resin that bends light to a similar degree to the cell walls renders the wood transparent.

The material the scientists worked with is thin -- typically less than a millimeter to around a centimeter thick. But the cells create a sturdy honeycomb structure, and the tiny wood fibers are stronger than the best carbon fibers, says materials scientist Liangbing Hu, who leads the research group working on transparent wood at the University of Maryland in College Park. And with the resin added, transparent wood outperforms plastic and glass: In tests measuring how easily materials fracture or break under pressure, transparent wood came out around three times stronger than transparent plastics like Plexiglass and about 10 times tougher than glass. "The results are amazing, that a piece of wood can be as strong as glass," says Hu, who highlighted the features of transparent wood in the 2023 Annual Review of Materials Research.

Space

Betelgeuse Will Briefly Disappear In Once-in-a-Lifetime Coincidence (scientificamerican.com) 33

Meghan Bartels reports via Scientific American: Some sky watchers this month will witness Betelgeuse, one of the brightest and best-known stars in the sky, nearly disappear. Mere seconds later -- despite astronomers' hopes that the star will meet its explosive end someday soon -- it will return, shining just as brightly as ever. Betelgeuse's brief blip of obscurity will mark a cosmic coincidence: an asteroid will block the star from view over a thin strip of Earth's surface. Scientists are hailing this celestial alignment as a once-in-a-lifetime occasion that, they hope, will permit them to glimpse Betelgeuse's ever changing surface of hot and cold patches in the best resolution to date. The opportunity comes courtesy of a sizable asteroid called Leona, which astronomers first spotted in 1891. On its own, Leona is just another space rock cluttering up the asteroid belt between Mars and Jupiter. But at 8:17 P.M. ET on December 11 Leona will slip directly between Earth and Betelgeuse, a red supergiant star that, unlike the asteroid, has been recognized by countless generations of humans around the world. [...]

To understand how special the event is, consider the total solar eclipse that will occur in April 2024. During the climax of the eclipse, viewers across a narrow strip of Earth's surface will see the moon pass directly in front of the sun. Because the two bodies appear as the same size in our sky, the moon will entirely block the visible disk of the sun and expose the faint, wispy halo called the corona, a layer of our home star's atmosphere that scientists otherwise cannot see from Earth. Similarly, the roughly 40-mile-wide Leona appears in the sky as about the same size as the enormous but very distant Betelgeuse. This will allow the asteroid to block all or most of the star's light when the two bodies perfectly align. But whereas Earth experiences a total solar eclipse every 18 months or so, occultations of bright stars such as Betelgeuse are extremely rare, occurring less than once a century [...].

Earth

Hidden Impacts of Ferocious Volcanic Eruption Finally Revealed (sciencealert.com) 20

Long-time Slashdot reader schwit1 shared an interesting article from ScienceAlert: Undersea volcanic eruptions account for more than three-quarters of all volcanism on Earth, but rarely do we see the impacts. The Hunga Tonga-Hunga Ha'apai eruption of 2022 was a dramatic exception. Its furious explosion from shallow waters broke the ocean surface and punched through the stratosphere, generating supercharged lighting and an atmospheric shock wave that circled the globe several times.

But there was far more to the fallout than satellite images could possibly capture or observers could report. We know the human toll this explosion took, but now a new study investigating the underwater impacts of the Hunga-Tonga eruption has detailed just how ferociously the explosion tore open the seafloor, ripped up undersea cables, and smothered marine life... The team also compiled a trove of data from ship-based sonar, sediment cores, geochemical analyses, water column samples, and video footage to chart the devastatingly powerful upheaval...

Their analyses show at least 6 cubic kilometers (km3) of seafloor was lost from within the caldera — 20 times the eruptive volume of the 1980 Mount St. Helens eruption — and an additional 3.5 km3 of material was blasted out of the Hunga volcano's submerged flanks... That leaves roughly four-fifths of the ejected material in the ocean; material that was funneled into fast-moving density flows that scoured out tracks 30 meters deep in the seafloor and accumulated 22 meters (72 feet) thick in some places.

Space

SpaceX Will Help US Space Force Launch Its Secretive X-37B Space Plane (nbcnews.com) 36

"The United States military is preparing to launch its secretive X-37B space plane on a seventh mission in orbit," reports NBC News.

Shaped like a small space shuttle, "It's an itty-bitty spaceplane, not quite 30 feet long and under 10 feet tall," writes the Washington Post, "with a pair of stubby wings and a rounded, bulldog-like nose." Space.com says the launch window for the uncrewed vehicle opens Monday at 8:14 p.m. EST.

From NBC News: For the first time, the X-37B will ride into orbit atop a SpaceX Falcon Heavy rocket. Since its debut more than a decade ago, the X-37B has been a source of intrigue within the space community, mostly owing to the mysterious nature of its activities in low Earth orbit. Despite not knowing its true purpose or location, skywatchers have occasionally spotted and photographed the space plane in the night sky using telescopes... The military is tight-lipped about such operations, but the Space Force said the X-37B missions "are key to ensuring safe and responsible operations in space for all users of the space domain..."
The "U.S. Space Force says that launching on SpaceX's Falcon Heavy rocket will allow testing "in new orbital regimes, experimenting with space domain awareness technologies and investigating the radiation effects to NASA materials."

The Washington Post notes that "The reference about 'space domain awareness' could mean that it will be keeping an eye on other satellites, potentially watching for threats": At least one part of the mission is known. The vehicle will "expose plant seeds to the harsh radiation environment of long-duration spaceflight" in an experiment for NASA. In the past, the Pentagon has also used the X-37B to test some of its cutting edge technologies, including a small solar panel designed to transform solar energy into microwaves, a technology that one day could allow energy harnessed in space to be beamed back to Earth...

If Sunday's X-37B mission is like previous ones, the spaceplane could be in space for a while. Its first flight, which launched in 2010, lasted 224 days.

Government

US Diet Committee Debates Whether Potatoes are Vegetables or 'Starchy Grain' (msn.com) 129

Every five years America's federal Department of Health updates its dietary guidelines with the latest nutrition science, affecting federal nutrition programs and various other government health initiatives.

Now an anonymous reader shared this report from the Wall Street Journal: Botanists count potatoes as a vegetable. But should Americans? The U.S. Dietary Guidelines Advisory Committee has sparked the question... White potatoes, which come in various colors, are classified as "starchy vegetables." But the committee could uproot potatoes from the vegetable bin and toss them in with a broader category of rice, other grains and carbohydrates as the Departments of Agriculture and Health and Human Services weigh updates to national diet guidelines for 2025.

The scientific debate isn't easy to follow. But it sounds like a half-baked idea to Kam Quarles, chief executive of the National Potato Council, a potato-industry group. The dietary guidelines shape nutrition advice to Americans, as well as what foods are served in school cafeterias. Potatoes, according to Quarles, should be respected as a gateway vegetable. "Kids are far more likely to eat" dishes with other vegetables if potatoes are involved, he said.

Not all parents swallow that a trail of tubers leads to leafy greens. Some complained about a Peppa Pig animated cartoon that featured a potato preaching the nutritional value of vegetables. "By the power of vegetables, I am here," Super Potato said, soaring through the sky, singing, "Fruit and vegetables keep us alive. Always remember to eat your five." The U.K.'s National Health Service, for one, doesn't count spuds toward the U.K.'s recommended five portions of fruits and vegetables a day. "It's a giant spud singing it. You're, like, 'Really? A potato's one of your five a day?'" said Dan Greef, the owner of Deliciously Guilt Free, a sugar-free bakery in Cambridge, U.K. He spent years persuading his two children to eat vegetables. Then, he said, "a drawing of a potato tells you it's fine, and you don't listen to your dad...."

Nutrition researchers say the potato contains helpful nutrients, including potassium and vitamin C, but its health benefits are diminished when it is fried. Nearly half of all U.S. potatoes eaten as food go into frozen products, mostly french fries, the USDA found.

For comparison, the article points out that under U.S. dietary guidelines, "corn on the cob is a starchy vegetable, while cornmeal is a grain."

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