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Octopus and Human Brains Share the Same 'Jumping Genes'

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著者: BeauHD
An anonymous reader quotes a report from SciTechDaily: An exceptional organism with an extremely complex brain and cognitive abilities makes the octopus very unique among invertebrates. So much so that it resembles vertebrates more than invertebrates in several aspects. The neural and cognitive complexity of these animals could originate from a molecular analogy with the human brain, as discovered by a research paper that was recently published in BMC Biology and coordinated by Remo Sanges from Scuola Internazionale Superiore di Studi Avanzati (SISSA) of Trieste and by Graziano Fiorito from Stazione Zoologica Anton Dohrn of Naples. This research shows that the same 'jumping genes' are active both in the human brain and in the brain of two species, Octopus vulgaris, the common octopus, and Octopus bimaculoides, the Californian octopus. A discovery that could help us understand the secret of the intelligence of these remarkable organisms. Sequencing the human genome revealed as early as 2001 that over 45% of it is composed of sequences called transposons, so-called 'jumping genes' that, through molecular copy-and-paste or cut-and-paste mechanisms, can 'move' from one point to another of an individual's genome, shuffling or duplicating. In most cases, these mobile elements remain silent: they have no visible effects and have lost their ability to move. Some are inactive because they have, over generations, accumulated mutations; others are intact, but blocked by cellular defense mechanisms. From an evolutionary point of view even these fragments and broken copies of transposons can still be useful, as 'raw matter' that evolution can sculpt. Among these mobile elements, the most relevant are those belonging to the so-called LINE (Long Interspersed Nuclear Elements) family, found in a hundred copies in the human genome and still potentially active. It has been traditionally though that LINEs' activity was just a vestige of the past, a remnant of the evolutionary processes that involved these mobile elements, but in recent years new evidence emerged showing that their activity is finely regulated in the brain. There are many scientists who believe that LINE transposons are associated with cognitive abilities such as learning and memory: they are particularly active in the hippocampus, the most important structure of our brain for the neural control of learning processes. The octopus' genome, like ours, is rich in 'jumping genes', most of which are inactive. Focusing on the transposons still capable of copy-and-paste, the researchers identified an element of the LINE family in parts of the brain crucial for the cognitive abilities of these animals. The discovery, the result of the collaboration between Scuola Internazionale Superiore di Studi Avanzati, Stazione Zoologica Anton Dohrn and Istituto Italiano di Tecnologia, was made possible thanks to next-generation sequencing techniques, which were used to analyze the molecular composition of the genes active in the nervous system of the octopus.

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Modern City Dwellers Have Lost About Half Their Gut Microbes

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著者: msmash
Comparing genomes of intestinal bacteria in various primates and human populations begins to pinpoint the possibly helpful microbes that have gone missing from our guts. From a report: Deep in the human gut, myriad "good" bacteria and other microbes help us digest our food, as well as keep us healthy by affecting our immune, metabolic, and nervous systems. Some of these humble microbial assistants have been in our guts since before humans became human -- certain gut microbes are found in almost all primates, suggesting they first colonized a common ancestor. But humans have also lost many of these helpers found in other primates and may be losing even more as people around the world continue to flock to cities, a researcher reported last week at a microbiology meeting in Washington, D.C. Those absent gut microbes could affect human health, he says. "This work helps us develop a new understanding of the course of human biological and cultural development," says Lev Tsypin, a microbiology graduate student at the California Institute of Technology who was not involved in the new study. The microbiome comprises all the bacteria, fungi, viruses, and other microscopic life that inhabit an individual, be it a person, a plant, or a planaria. For humans and many other species, the best characterized microbiome centers on the bacteria in the gut. The more microbiologists study these gut microbes, the more they link the bacteria to functions of their hosts. In humans, for example, gut bacteria influence how the immune system responds to pathogens and allergens, or interact with the brain, affecting mood. Andrew Moeller, an evolutionary biologist at Cornell University, was one of the first to show that gut bacteria and humans have built these relationships over a very long time. Six years ago, he and colleagues reported the work showing human gut microbes are very similar to those in other primates, suggesting their intestinal presence predates the evolution of humans. But his follow-up studies, and work by others, also indicate the human gut microbiome has, in a general sense, become less diverse than the gut microbes in our current primate cousins. One study found 85 microbial genera, such as Bacteroides and Bifidobacterium, in the guts of wild apes, but just 55 in people in U.S. cities. Splitting the difference, people in less developed parts of the world have between 60 and 65 of those bacterial groups, an observation that ties the decrease in microbial diversity to urbanization.

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Viruses Survive in Fresh Water by 'Hitchhiking' on Plastic, Study Finds

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著者: msmash
Dangerous viruses can remain infectious for up to three days in fresh water by hitchhiking on plastic, researchers have found. From a report: Enteric viruses that cause diarrhoea and stomach upsets, such as rotavirus, were found to survive in water by attaching to microplastics, tiny particles less than 5mm long. They remain infectious, University of Stirling researchers found, posing a potential health risk. Prof Richard Quilliam, lead researcher on the project at Stirling University, said: "We found that viruses can attach to microplastics and that allows them to survive in the water for three days, possibly longer." While previous research had been carried out in sterile settings, this is the first research into how viruses behave in the environment, Quilliam said. However, he used standard laboratory methods to determine whether viruses found on microplastics in water were infectious. "We weren't sure how well viruses could survive by 'hitchhiking' on plastic in the environment, but they do survive and they do remain infectious," he said. The findings, part of a $2.27m project funded by the Natural Environment Research Council looking at how plastics transport bacteria and viruses, concluded that microplastics enabled pathogen transfer in the environment. The paper is published in the journal Environmental Pollution. "Being infectious in the environment for three days, that's long enough to get from the wastewater treatment works to the public beach," Quilliam said. Wastewater treatment plants were unable to capture microplastics, he said. "Even if a wastewater treatment plant is doing everything it can to clean sewage waste, the water discharged still has microplastics in it, which are then transported down the river, into the estuary and wind up on the beach."

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Is Dyslexia an Evolutionary Advantage Rather Than a 'Disorder'?

LinkedIn recently added 'dyslexic thinking' as an official skill. And now the U.K. national newspaper the Telegraph reports on scientists arguing that dyslexia is not a "disorder" — but an evolutionarily beneficial willingness to explore: The experts suggested that dyslexia, which causes difficulty reading, writing and spelling, is a useful specialisation and not a "neurocognitive condition".... About one in five people have dyslexia, and their tendency to push the envelope would have been balanced out by other members of a prehistoric society, leading to a well-rounded group with equally useful skill sets. However, Dr Helen Taylor, from the University of Strathclyde, and Dr Martin Vestergaard, from the University of Cambridge, said that dyslexia was now seen as a problem because modern education systems focused on the things sufferers struggled with and neglected what they excelled at. They reassessed past studies on dyslexic individuals and disagreed with the prevailing theory that it was a cognitive deficit.... [S]ince the invention of written language, dyslexia has been seen as a problem, not a talent. "Schools, academic institutes and workplaces are not designed to make the most of explorative learning," said Dr Taylor. "We urgently need to start nurturing this way of thinking to allow humanity to continue to adapt and solve key challenges." They posit that dyslexic people are naturally more skilled "in realms like discovery, invention and creativity" and that this specialisation stems from millennia of human evolution.... Without the streak of curiosity and willingness to investigate that is commonplace in dyslexic brains, groups of people would likely struggle to survive, they said. "The deficit-centred view of dyslexia isn't telling the whole story," said Dr Taylor. "We believe that the areas of difficulty experienced by people with dyslexia result from a cognitive trade-off between exploration of new information and exploitation of existing knowledge, with the upside being an explorative bias that could explain enhanced abilities observed in certain realms like discovery, invention and creativity. The researchers argue this "explorative specialization in people with dyslexia could help explain why they have difficulties with tasks related to exploitation, such as reading and writing. "It could also explain why people with dyslexia appear to gravitate towards certain professions that require exploration-related abilities, such as arts, architecture, engineering and entrepreneurship." Thanks to Slashdot reader Bruce66423 for sharing the story

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Engineers Demonstrate Quantum Integrated Circuit Made Up of Just a Few Atoms

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著者: BeauHD
Engineers in Sydney have demonstrated a quantum integrated circuit made up of just a few atoms. By precisely controlling the quantum states of the atoms, the new processor can simulate the structure and properties of molecules in a way that could unlock new materials and catalysts. New Atlas reports: The new quantum circuit comes from researchers at the University of New South Wales (UNSW) and a start-up company called Silicon Quantum Computing (SQC). It's essentially made up of 10 carbon-based quantum dots embedded in silicon, with six metallic gates that control the flow of electrons through the circuit. It sounds simple enough, but the key lies in the arrangement of these carbon atoms down to the sub-nanometer scale. Relative to each other, they're precisely positioned to mimic the atomic structure of a particular molecule, allowing scientists to simulate and study the structure and energy states of that molecule more accurately than ever before. In this case, they arranged the carbon atoms into the shape of the organic compound polyacetylene, which is made up of a repeating chain of carbon and hydrogen atoms with an alternating pattern of single and double carbon bonds between them. To simulate those bonds, the team placed the carbon atoms at different distances apart. Next, the researchers ran an electrical current through the circuit to check whether it would match the signature of a natural polyacetylene molecule -- and sure enough, it did. In other tests, the team created two different versions of the chain by cutting bonds at different places, and the resulting currents matched theoretical predictions perfectly. The significance of this new quantum circuit, the team says, is that it could be used to study more complicated molecules, which could eventually yield new materials, pharmaceuticals, or catalysts. This 10-atom version is right on the limit of what classical computers can simulate, so the team's plans for a 20-atom quantum circuit would allow for simulation of more complex molecules for the first time. The research has been published in the journal Nature.

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The Sleep Debt Collector Is Here

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著者: msmash
Recent studies in humans and mice have shown that late nights and early mornings may cause long lasting damage to your brain. From a report: The sleep debt collectors are coming. They want you to know that there is no such thing as forgiveness, only a shifting expectation of how and when you're going to pay them back. You think of them as you lie in bed at night. How much will they ask for? Are you solvent? You fall asleep, then wake up in a cold sweat an hour later. You fall asleep, then wake up, drifting in and out of consciousness until morning. As most every human has discovered, a couple nights of bad sleep is often followed by grogginess, difficulty concentrating, irritability, mood swings and sleepiness. For years, it was thought that these effects, accompanied by cognitive impairments like lousy performances on short-term memory tests, could be primarily attributed to a chemical called adenosine, a neurotransmitter that inhibits electrical impulses in the brain. Spikes of adenosine had been consistently observed in sleep-deprived rats and humans. Adenosine levels can be quickly righted after a few nights of good sleep, however. This gave rise to a scientific consensus that sleep debt could be forgiven with a couple of quality snoozes -- as reflected in casual statements like "I'll catch up on sleep" or "I'll be more awake tomorrow." But a review article published recently in the journal Trends in Neurosciences contends that the folk concept of sleep as something that can be saved up and paid off is bunk. The review, which canvassed the last couple of decades of research on long term neural effects of sleep deprivation in both animals and humans, points to mounting evidence that getting too little sleep most likely leads to long-lasting brain damage and increased risk of neurodegenerative disorders like Alzheimer's disease. "This is really, really important in setting the stage for what needs to be done in sleep health and sleep science," said Mary Ellen Wells, a sleep scientist at the University of North Carolina, who did not contribute to the review.

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Female Scientists Less Likely To Be Given Authorship Credits, Analysis Finds

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著者: msmash
Female scientists are less likely to receive authorship credit or to be named on patents related to the work they do compared with their male counterparts -- including in fields such as healthcare, where women dominate -- data suggests. From a report: This gender gap may help to explain well-documented disparities in the apparent contributions of male and female scientists -- such as that of Rosalind Franklin, whose pivotal contribution to the discovery of the structure of DNA initially went unrecognised because she was not cited on the core Nature article by James Watson and Francis Crick. "We have known for a long time that women publish and patent at a lower rate than men. But, because previous data never showed who participated in research, no one knew why," said Prof Julia Lane at New York University in the US, who led the new research. Lane and her colleagues analysed administrative data on research projects conducted at 52 US colleges and universities between 2013 and 2016. They matched information about 128,859 scientists to 39,426 journal articles and 7,675 patents, looking at which people who worked on individual projects received credit and which did not.

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Government Scientists Discover Biggest Bacteria Ever, Visible To Naked Eye

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著者: BeauHD
An anonymous reader quotes a report from Motherboard: Scientists have discovered a bacteria with cells that measure a full centimeter in length, an astonishing size that makes it by far the largest bacterial species ever found and even "challenges our concept of a bacterial cell," reports a new study. Bacteria are an extraordinarily diverse group of organisms that have inhabited Earth for billions of years and have evolved to occupy a dizzying variety of niches. Still, almost all of these microbes are composed of simple cells that measure about two microns in diameter, which is about 40 times smaller than a strand of human hair. Thiomargarita magnifica, a bacteria discovered on sunken red mangrove leaves in Guadeloupe, Lesser Antilles, has blown this standard scale out of the water. The species has evolved filamentary cells that are "larger than all other known giant bacteria by ~50-fold," making them "visible to the naked eye," according to a study published on Thursday in Science. Scientists led by Jean-Marie Volland, a marine biologist who holds joint appointments at the Laboratory for Research in Complex Systems and the Joint Genome Institute (JGI), a U.S. Department of Energy office at Lawrence Berkeley National Laboratory, suspect that this record-breaking adaptation is partly due to the astonishing number of duplicated genes wielded by T. magnifica, an ability that is known as polyploidy. [...] The results revealed that these bacteria contain DNA clusters in their cells, which are located in compartments bordered by membranes that the team called "pepins." These organized pepins provide a stark contrast to the free-floating DNA seen in the cells of most bacteria. In addition, the team's genetic sequencing revealed that T. magnifica contains hundreds of thousands of genome copies that are dispersed across the cell, adding up to about three times the number of genes in most bacteria, which is an extreme example of polyploidy. "These cellular features likely allow the organism to grow to an unusually large size and circumvent some of the biophysical and bioenergetic limitations on growth," Volland and his colleagues said.

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Scientists Hacked a Locust's Brain To Sniff Out Human Cancer

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著者: msmash
Cyborg locust brains can help spot the telltale signs of human cancer in the lab, a new study has shown. The team behind the work hopes it could one day lead to an insect-based breath test that could be used in cancer screening, or inspire an artificial version that works in much the same way. From a report: Other animals have been taught to spot signs that humans are sick. For example, dogs can be trained to detect when their owners' blood sugar levels start to drop, or if they develop cancer, tuberculosis, or even covid. In all cases, the animals are thought to be sensing chemicals that people emit through body odor or breath. The mix of chemicals can vary depending on a person's metabolism, which is thought to change when we get sick. But dogs are expensive to train and look after. And making a device that mimics a dog's nose has proved extremely difficult to do, says Debajit Saha, one of the scientists behind the latest work, which has not yet been peer-reviewed. "These changes are almost in parts per trillion," says Saha, a neural engineer at Michigan State University. This makes them hard to pick up even with state-of-the-art technologies, he adds. But animals have evolved to interpret such subtle changes in scents. So he and his colleagues decided to "hijack" an animal brain instead.

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Physicists Say They've Built an Atom Laser That Can Run 'Forever'

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著者: BeauHD
A new breakthrough has allowed physicists to create a beam of atoms that behaves the same way as a laser, and that can theoretically stay on "forever." ScienceAlert reports: At the root of the atom laser is a state of matter called a Bose-Einstein condensate, or BEC. A BEC is created by cooling a cloud of bosons to just a fraction above absolute zero. At such low temperatures, the atoms sink to their lowest possible energy state without stopping completely. When they reach these low energies, the particles' quantum properties can no longer interfere with each other; they move close enough to each other to sort of overlap, resulting in a high-density cloud of atoms that behaves like one 'super atom' or matter wave. However, BECs are something of a paradox. They're very fragile; even light can destroy a BEC. Given that the atoms in a BEC are cooled using optical lasers, this usually means that a BEC's existence is fleeting. Atom lasers that scientists have managed to achieve to date have been of the pulsed, rather than continuous variety; and involve firing off just one pulse before a new BEC needs to be generated. In order to create a continuous BEC, a team of researchers at the University of Amsterdam in the Netherlands realized something needed to change. "In previous experiments, the gradual cooling of atoms was all done in one place. In our setup, we decided to spread the cooling steps not over time, but in space: we make the atoms move while they progress through consecutive cooling steps," explained physicist Florian Schreck. "In the end, ultracold atoms arrive at the heart of the experiment, where they can be used to form coherent matter waves in a BEC. But while these atoms are being used, new atoms are already on their way to replenish the BEC. In this way, we can keep the process going -- essentially forever." The research has been published in the journal Nature.

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Ancient DNA Solves Mystery Over Origin of Medieval Black Death

Long-time Slashdot reader schwit1 writes: Ancient DNA from bubonic plague victims buried in cemeteries on the old Silk Road trade route in Central Asia has helped solve an enduring mystery, pinpointing an area in northern Kyrgyzstan as the launching point for the Black Death that killed tens of millions of people in the mid-14th century. The Black Death was the deadliest pandemic on record. It may have killed 50% to 60% of the population in parts of Western Europe and 50% in the Middle East, combining for about 50-60 million deaths, Slavin said. An "unaccountable number" of people also died in the Caucasus, Iran and Central Asia, Slavin added. Researchers said on Wednesday they retrieved ancient DNA traces of the Yersinia pestis plague bacterium from the teeth of three women buried in a medieval Nestorian Christian community in the Chu Valley near Lake Issyk Kul in the foothills of the Tian Shan mountains who perished in 1338-1339. The earliest deaths documented elsewhere in the pandemic were in 1346. Reconstructing the pathogen's genome showed that this strain not only gave rise to the one that caused the Black Death that mauled Europe, Asia, the Middle East and North Africa but also to most plague strains existing today. "Our finding that the Black Death originated in Central Asia in the 1330s puts centuries-old debates to rest," said historian Philip Slavin of the University of Stirling in Scotland, co-author of the study published in the journal Nature.

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Physicists Link Two Time Crystals In Seemingly Impossible Experiment

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著者: BeauHD
An anonymous reader quotes a report from Live Science: Physicists have created a system of two connected time crystals, which are strange quantum systems that are stuck in an endless loop to which the normal laws of thermodynamics do not apply. By connecting two time crystals together, the physicists hope to use the technology to eventually build a new kind of quantum computer. "It is a rare privilege to explore a completely novel phase of matter," Samuli Autti, the lead scientist on the project from Lancaster University in the United Kingdom, told Live Science in an email. [...] In the new study, Autti and his team used "magnons" to build their time crystal. Magnons are "quasiparticles," which emerge in the collective state of a group of atoms. In this case, the team of physicists took helium-3 -- a helium atom with two protons but only one neutron -- and cooled it to within a ten-thousandth of a degree above absolute zero. At that temperature, the helium-3 transformed into a Bose-Einstein condensate, where all the atoms share a common quantum state and work in concert with each other. In that condensate, all the spins of the electrons in the helium-3 linked up and worked together, generating waves of magnetic energy, the magnons. These waves sloshed back and forth forever, making them a time crystal. Autti's team took two groups of magnons, each one operating as its own time crystal, and brought them close enough to influence each other. The combined system of magnons acted as one time crystal with two different states. Autti's team hopes that their experiments can clarify the relationship between quantum and classical physics. Their goal is to build time crystals that interact with their environments without the quantum states disintegrating, allowing the time crystal to keep running while it is used for something else. It wouldn't mean free energy -- the motion associated with a time crystal doesn't have kinetic energy in the usual sense, but it could be used for quantum computing. Having two states is important, because that is the basis for computation. In classical computer systems, the basic unit of information is a bit, which can take either a 0 or 1 state, while in quantum computing, each "qubit" can be in more than one place at the same time, allowing for much more computing power. The research has been published in the journal Nature Communications.

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Greenery and Bright Colours in Cities Can Boost Morale, Study Says

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著者: msmash
Having bright colours and greenery in our cities can make people happier and calmer, according to an unusual experiment involving virtual reality headsets. From a report: A team of researchers at the University of Lille, in France, used VR to test how volunteers reacted to variations of a minimalist concrete, glass and metal urban landscape. The 36 participants walked on the spot in a laboratory wearing a VR headset with eye trackers, and researchers tweaked their surroundings, adding combinations of vegetation, as well as bright yellow and pink colours, and contrasting, angular patterns on the path. By tracking their blink rate, the researchers learned about what the volunteers were most interested in. The participants then filled out a questionnaire about their experience. The researchers found that the volunteers walked more slowly and their heart rate increased when they saw green vegetation in their urban setting. They also kept their heads higher, looking forward and around, instead of towards the ground. While adding and taking away colour didn't make quite as much of a difference for the participants, they were more curious and alert when colourful patterns were added to the ground they were virtually stepping on, according to the study. According to Yvonne Delevoye-Turrell, a professor of cognitive psychology at the university and the lead author on this study, the results demonstrated that the urban experience had been made more pleasurable.

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Why Chemists Can't Quit Palladium

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著者: msmash
A retracted paper highlights chemistry's history of trying to avoid the expensive, toxic -- but necessary -- catalyst. From a report: It's hard to find a place on Earth untouched by palladium. The silvery-white metal is a key part of catalytic converters in the world's 1.4 billion cars, which spew specks of palladium into the atmosphere. Mining and other sources add to this pollution. As a result, traces of palladium show up in some of the most remote spots on Earth, from Antarctica to the top of the Greenland ice sheet. Palladium is also practically indispensable for making drugs. That's because catalysts with palladium atoms at their core have an unmatched ability to help stitch together carbon --carbon bonds. This kind of chemical reaction is key to building organic molecules, especially those used in medications. "Every pharmaceutical we produce at some point or another has a palladium-catalysed step in it," says Per-Ola Norrby, a pharmaceutical researcher at drug giant AstraZeneca in Gothenburg, Sweden. Palladium-catalysed reactions are so valuable that, in 2010, their discoverers shared a Nobel prize. But despite its versatility, chemists are trying to move away from palladium. The metal is more expensive than gold, and molecules that contain palladium can also be extremely toxic to humans and wildlife. Chemical manufacturers have to separate out all traces of palladium from their products and carefully dispose of the hazardous waste, which adds extra expense. Thomas Fuchb, a medicinal chemist at the life-sciences company Merck in Darmstadt, Germany, gives the example of a reaction to make 3 kilograms of a drug molecule for which the ingredients cost US$250,000. The palladium catalyst alone adds $100,000; purifying it out of the product another $30,000. Finding less-toxic alternatives to the metal could help to reduce environmental harm from palladium waste and move the chemicals industry towards 'greener' reactions, says Tianning Diao, an organometallic chemist at New York University. Researchers hope to swap palladium for more common metals, such as iron and nickel, or invent metal-free catalysts that sidestep the issue altogether. Several times in the past two decades, researchers have reported finding palladium-free catalysts. But in what has become a recurring pattern for the field, each heralded discovery turned out to be a mistake.

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Signs Are Not Enough To Save Beachgoers from Deadly Currents

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著者: msmash
Keeping people out of rip currents is more about reading human behavior than reading warning signs. From a report: Worldwide, rips cause hundreds of drownings and necessitate tens of thousands of rescues every year. In Australia, where 85 percent of the population lives within an hour's drive of the coast, rips cause more fatalities than floods, cyclones, and shark attacks combined. In 1938, one of the country's most popular beaches, Sydney's Bondi Beach, was the site of an infamous rip-current tragedy: within minutes, roughly 200 swimmers were swept away by a rip, leaving 35 people unconscious and five dead. More often, however, rips take one life at a time, garnering little media attention. For many casual beach visitors, the toll of rip currents goes unnoticed. [...] Although almost three-quarters of beach users said they knew what a rip current is, only 54 percent could correctly define it. In addition, only half of the people she surveyed remembered seeing either the warning signs or the colored flags denoting surf conditions that were posted on or near the main access point to each beach. An even smaller percentage could recall what color the flags had been -- green for calm, yellow for moderate, or red for dangerous conditions. "I was genuinely shocked," Locknick says. [...] Part of the challenge of preventing rip-related drownings stems from the lack of a simple method to escape them. Rip currents form when waves pile water near the shoreline. The water then gushes back out to sea, taking the path of least resistance. It might flow along channels carved in between sandbars or next to solid structures, such as jetties or rocky headlands. These types of rips can stick around year after year. Others are more erratic, creating fleeting bursts of seaward-flowing water on smooth, open beaches. People often mislabel rip currents as undertows or rip tides. Rip currents are not caused by tides, however, and undertows are a different, weaker current, formed when water pushed onto the beach moves back offshore along the seabed. Some telltale signs of a rip include a streak of churned-up, sandy water or a dark, flat gap between breaking waves. It's not surprising that rip currents are often misunderstood by the public because, for decades, beach-safety experts also had an oversimplified perception of their mechanics. In some of the earliest research on rips in the mid-20th century, American scientists watched sticks, pieces of kelp, and volleyballs float out to sea and described lanes of flowing water extending more than 300 meters offshore. This work formed the basis for the popular view of rip currents as jets flowing perpendicular to the beach, shooting out past the surf. To escape the river of current, experts recommended that bathers swim parallel to the beach -- a message once broadcast through education campaigns and warning signs in the United States and Australia. As it turns out, that approach may not always work.

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Ten Years After the Higgs, Physicists Face the Nightmare of Finding Nothing Else

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著者: msmash
A decade ago, particle physicists thrilled the world. On 4 July 2012, 6000 researchers working with the world's biggest atom smasher, the Large Hadron Collider (LHC) at the European particle physics laboratory, CERN, announced they had discovered the Higgs boson, a massive, fleeting particle key to their abstruse explanation of how other fundamental particles get their mass. The discovery fulfilled a 45-year-old prediction, completed a theory called the standard model, and thrust physicists into the spotlight. Then came a long hangover. From a report: Before the 27-kilometer-long ring-shaped LHC started to take data in 2010, physicists fretted that it might produce the Higgs and nothing else, leaving no clue to what lies beyond the standard model. So far, that nightmare scenario is coming true. "It's a bit disappointing," allows Barry Barish, a physicist at the California Institute of Technology. "I thought we would discover supersymmetry," the leading extension of the standard model. It's too early to despair, many physicists say. After 3 years of upgrades, the LHC is now powering up for the third of five planned runs, and some new particle could emerge in the billions of proton-proton collisions it will produce every second. In fact, the LHC should run for another 16 years, and with further upgrades should collect 16 times as much data as it already has. All those data could reveal subtle signs of novel particles and phenomena. Still, some researchers say the writing is on the wall for collider physics. "If they don't find anything, this field is dead," says Juan Collar, a physicist at the University of Chicago who hunts dark matter in smaller experiments. John Ellis, a theorist at King's College London, says hopes of a sudden breakthrough have given way to the prospect of a long, uncertain grind toward discovery. "It's going to be like pulling teeth, not like teeth falling out."

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As the Large Hadron Collider Revs Up, Physicists' Hopes Soar

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著者: msmash
The particle collider at CERN will soon restart. From a report: In April, scientists at the European Center for Nuclear Research, or CERN, outside Geneva, once again fired up their cosmic gun, the Large Hadron Collider. After a three-year shutdown for repairs and upgrades, the collider has resumed shooting protons -- the naked guts of hydrogen atoms -- around its 17-mile electromagnetic underground racetrack. In early July, the collider will begin crashing these particles together to create sparks of primordial energy. And so the great game of hunting for the secret of the universe is about to be on again, amid new developments and the refreshed hopes of particle physicists. Even before its renovation, the collider had been producing hints that nature could be hiding something spectacular. Mitesh Patel, a particle physicist at Imperial College London who conducts an experiment at CERN, described data from his previous runs as "the most exciting set of results I've seen in my professional lifetime." A decade ago, CERN physicists made global headlines with the discovery of the Higgs boson, a long-sought particle, which imparts mass to all the other particles in the universe. What is left to find? Almost everything, optimistic physicists say. When the CERN collider was first turned on in 2010, the universe was up for grabs. The machine, the biggest and most powerful ever built, was designed to find the Higgs boson. That particle is the keystone of the Standard Model, a set of equations that explains everything scientists have been able to measure about the subatomic world. But there are deeper questions about the universe that the Standard Model does not explain: Where did the universe come from? Why is it made of matter rather than antimatter? What is the "dark matter" that suffuses the cosmos? How does the Higgs particle itself have mass? Physicists hoped that some answers would materialize in 2010 when the large collider was first turned on. Nothing showed up except the Higgs -- in particular, no new particle that might explain the nature of dark matter. Frustratingly, the Standard Model remained unshaken.

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Short-Sightedness Was Rare. In Asia, It Is Becoming Ubiquitous

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著者: msmash
Researchers have found that being outside drastically reduces the risk of developing short-sightedness. From a report: In the early 1980s Taiwan's army realised it had a problem. More and more of its conscripts seemed to be short-sighted, meaning they needed glasses to focus on distant objects. "They were worried that if the worst happened [ie, an attack by China] their troops would be fighting at a disadvantage," says Ian Morgan, who studies myopia at Australian National University, in Canberra. An island-wide study in 1983 confirmed that around 70% of Taiwanese school leavers needed glasses or contact lenses to see properly. These days, that number is above 80%. But happily for Taiwan's generals, the military disparity has disappeared. Over the past few decades myopia rates have soared across East Asia (see chart 1 in the linked story). In the 1960s around 20-30% of Chinese school-leavers were short-sighted. These days they are just as myopic as their cousins across the straits, with rates in some parts of China running at over 80%. Elsewhere on the continent things are even worse. One study of male high-school leavers in Seoul found 97% were short-sighted. Hong Kong and Singapore are not far behind. And although the problem is worst in East Asia, it is not unique to it. Reliable numbers for America and Europe are harder to come by. But one review article, published in 2015, claimed a European rate of between 20% and 40% -- an order of magnitude higher than that which people working in the field think is the "natural," background rate. For most of those affected, myopia is a lifelong, expensive nuisance. But severe myopia can lead to untreatable vision loss, says Annegret Dahlmann-Noor, a consultant ophthalmologist at Moorfields Eye Hospital, in London. A paper published in 2019 concluded that each one-dioptre worsening in myopia was associated with a 67% increase in prevalence of myopic maculopathy, an untreatable condition that causes blindness. (A dioptre is a measure of a lens's focusing power.) In some parts of East Asia, 20% of young people have severe myopia, defined as -6 dioptres or worse (see chart 2 in linked story). "This is storing up a big problem for the coming decades," says Kathryn Rose, head of orthoptics at the University of Technology, Sydney.

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Physicists Discover Never-Before Seen Particle Sitting On a Tabletop

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著者: BeauHD
Researchers have discovered a new particle that is a magnetic relative of the Higgs boson. Whereas the discovery of the Higgs boson required the tremendous particle-accelerating power of the Large Hadron Collider (LHC), this never-before-seen particle -- dubbed the axial Higgs boson -- was found using an experiment that would fit on a small kitchen countertop. Live Science reports: As well as being a first in its own right, this magnetic cousin of the Higgs boson -- the particle responsible for granting other particles their mass -- could be a candidate for dark matter, which accounts for 85%t of the total mass of the universe but only reveals itself through gravity. The axial Higgs boson differs from the Higgs boson, which was first detected by the ATLAS and CMS detectors at the LHC a decade ago in 2012, because it has a magnetic moment, a magnetic strength or orientation that creates a magnetic field. As such, it requires a more complex theory to describe it than its non-magnetic mass-granting cousin. [...] "When my student showed me the data I thought she must be wrong," Kenneth Burch, a professor of physics at Boston College and lead researcher of the team that made the discovery, told Live Science. "It's not every day you find a new particle sitting on your tabletop." [...] "We found the axial Higgs boson using a tabletop optics experiment which sits on a table measuring about 1 x 1 meters by focusing on a material with a unique combination of properties," Burch continued. "Specifically we used rare-earth Tritelluride (RTe3) [a quantum material with a highly 2D crystal structure]. The electrons in RTe3 self-organize into a wave where the density of the charge is periodically enhanced or reduced." The size of these charge density waves, which emerge above room temperature, can be modulated over time, producing the axial Higgs mode. In the new study, the team created the axial Higgs mode by sending laser light of one color into the RTe3 crystal. The light scattered and changed to a color of lower frequency in a process known as Raman scattering, and the energy lost during the color change created the axial Higgs mode. The team then rotated the crystal and found that the axial Higgs mode also controls the angular momentum of the electrons, or the rate at which they move in a circle, in the material meaning this mode must also be magnetic. "Originally we were simply investigating the light scattering properties of this material. When carefully examining the symmetry of the response -- how it differed as we rotated the sample -- we discovered anomalous changes that were the initial hints of something new," Burch explained. "As such, it is the first such magnetic Higgs to be discovered and indicates the collective behavior of the electrons in RTe3 is unlike any state previously seen in nature." The report notes that this is also the first time scientists have observed a state with multiple broken symmetries. "Symmetry breaking occurs when a symmetric system that appears the same in all directions becomes asymmetric," reports Live Science. "Oregon University suggests thinking of this as being like a spinning coin that has two possible states. The coin eventually falls onto its head or tail face thus releasing energy and becoming asymmetrical." The findings have been published in the journal Nature.

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NYC Cancer Trial Delivers 'Unheard-of' Result: Complete Remission for Everyone

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著者: msmash
A small NYC-led cancer trial has achieved a result reportedly never before seen - the total remission of cancer in all of its patients. From a report: To be sure, the trial -- led by doctors at Memorial Sloan Kettering and backed by drug maker GlaxoSmithKline -- has only completed treatment of 12 patients, with a specific cancer in its early stages and with a rare mutation as well. But the results, reported Sunday in the New England Journal of Medicine and the New York Times, were still striking enough to prompt multiple physicians to tell the paper they were believed to be unprecedented. One cancer specialist told the Times it was an "unheard-of" result. According to the NEJM paper and the Times report, all 12 patients had rectal cancer that had not spread beyond the local area, and their tumors all exhibited a mutation affecting the ability of cells to repair damage to DNA.

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