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Fake Scientific Papers Are Alarmingly Common

著者: msmash
2023年5月13日 02:22
From a Science magazine report, shared by schwit1: When neuropsychologist Bernhard Sabel put his new fake-paper detector to work, he was "shocked" by what it found. After screening some 5000 papers, he estimates up to 34% of neuroscience papers published in 2020 were likely made up or plagiarized; in medicine, the figure was 24%. Both numbers, which he and colleagues report in a medRxiv preprint posted on 8 May, are well above levels they calculated for 2010 -- and far larger than the 2% baseline estimated in a 2022 publishers' group report. "It is just too hard to believe" at first, says Sabel of Otto von Guericke University Magdeburg and editor-in-chief of Restorative Neurology and Neuroscience. It's as if "somebody tells you 30% of what you eat is toxic." His findings underscore what was widely suspected: Journals are awash in a rising tide of scientific manuscripts from paper mills -- secretive businesses that allow researchers to pad their publication records by paying for fake papers or undeserved authorship. "Paper mills have made a fortune by basically attacking a system that has had no idea how to cope with this stuff," says Dorothy Bishop, a University of Oxford psychologist who studies fraudulent publishing practices. A 2 May announcement from the publisher Hindawi underlined the threat: It shut down four of its journals it found were "heavily compromised" by articles from paper mills. Sabel's tool relies on just two indicators -- authors who use private, noninstitutional email addresses, and those who list an affiliation with a hospital. It isn't a perfect solution, because of a high false-positive rate. Other developers of fake-paper detectors, who often reveal little about how their tools work, contend with similar issues. Still, the detectors raise hopes for gaining the advantage over paper mills, which churn out bogus manuscripts containing text, data, and images partly or wholly plagiarized or fabricated, often massaged by ghost writers. Some papers are endorsed by unrigorous reviewers solicited by the authors. Such manuscripts threaten to corrupt the scientific literature, misleading readers and potentially distorting systematic reviews. The recent advent of artificial intelligence tools such as ChatGPT has amplified the concern. To fight back, the International Association of Scientific, Technical, and Medical Publishers (STM), representing 120 publishers, is leading an effort called the Integrity Hub to develop new tools. STM is not revealing much about the detection methods, to avoid tipping off paper mills. "There is a bit of an arms race," says Joris van Rossum, the Integrity Hub's product director. He did say one reliable sign of a fake is referencing many retracted papers; another involves manuscripts and reviews emailed from internet addresses crafted to look like those of legitimate institutions. Twenty publishers -- including the largest, such as Elsevier, Springer Nature, and Wiley -- are helping develop the Integrity Hub tools, and 10 of the publishers are expected to use a paper mill detector the group unveiled in April.

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New Genome Map Tries To Capture All Human Genetic Variation

著者: BeauHD
2023年5月11日 12:30
An anonymous reader shares an excerpt from MIT Technology Review: Today, researchers announced yet another version of the human genome map, which they say combines the complete DNA of 47 diverse individuals -- Africans, Native Americans, and Asians, among other groups -- into one giant genetic atlas that they say better captures the surprising genetic diversity of our species. The new map, called a "pangenome," has been a decade in the making, and researchers say it will only get bigger, creating an expanding view of the genome as they add DNA from another 300 people from around the globe. It was published in the journal Nature today. People's genomes are largely alike, but it's the hundreds of thousands of differences, often just single DNA letters, that explain why each of us is unique. The new pangenome, researchers say, should make it possible to observe this diversity in more detail than ever before, highlighting so-called evolutionary hot spots as well as thousands of surprisingly large differences, like deleted, inverted, or duplicated genes, that aren't observable in conventional studies. The pangenome relies on a mathematical concept called a graph, which you can imagine as a massive version of connect-the-dots. Each dot is a segment of DNA. To draw a particular person's genome, you start connecting the numbered dots. Each person's DNA can take a slightly different path, skipping some numbers and adding others. One payoff of the new pangenome could be better ways to diagnose rare diseases, although practical applications aren't easy to name. Instead, scientists say it's mainly giving them insight into some of the "dark matter" of the genome that's previously been hard to see, including strange regions of chromosomes that seem to share and exchange genes. For now, most biologists and doctors will stick to the existing "reference genome," the one first produced in draft form in 2001 and gradually improved. It answers most questions researchers are interested in, and all their computer tools work with it. The reason a reference genome is important is that when a new person's genome is sequenced, that sequence is projected onto the reference in order to organize and read the new data. Yet since the current reference is just one possible genome, missing bits that some people have, some information can't be analyzed and is usually ignored. Researchers call this effect "reference bias" or, more simply, the streetlamp problem. You don't see where you don't look. Officials with NIH said they hoped the new update to the genome map would make gene research more "equitable." That's because the more different your genome is from the current reference, the more information about you could be missed. The existing reference is largely the DNA of one African-American man, although it includes segments from several other people as well. "If the genome you want to analyze has sequences that are not in that reference, they will be missed in the analysis," says Deanna Church, a consultant with the business incubator General Inception, who previously held a key role at NIH managing the reference genome. "In reality, the notion that there is a 'human genome' is really the problem," she says. "The current version is the simplest model you can make. It made sense when we started ... But now we need better models."

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'Sleep Language' Could Enable Communication During Lucid Dreams

著者: BeauHD
2023年5月10日 16:00
Researchers have developed a "language" called Remmyo, which relies on specific facial muscle movements that can occur during rapid eye movement (REM) sleep. People who are capable of lucid dreaming can learn this language during their waking hours and potentially communicate while they are asleep. Ars Technica reports: "You can transfer all important information from lucid dreams using no more than three letters in a word," [sleep expert Michael Raduga], who founded Phase Research Center in 2007 to study sleep, told Ars. "This level of optimization took a lot of time and intellectual resources." Remmyo consists of six sets of facial movements that can be detected by electromyography (EMG) sensors on the face. Slight electrical impulses that reach facial muscles make them capable of movement during sleep paralysis, and these are picked up by sensors and transferred to software that can type, vocalize, and translate Remmyo. Translation depends on which Remmyo letters are used by the sleeper and picked up by the software, which already has information from multiple dictionaries stored in its virtual brain. It can translate Remmyo into another language as it is being "spoken" by the sleeper. "We can digitally vocalize Remmyo or its translation in real time, which helps us to hear speech from lucid dreams," Raduga said. For his initial experiment, Raduga used the sleep laboratory of the Neurological Clinic of Frankfurt University in Germany. His subjects had already learned Remmyo and were also trained to enter a state of lucid dreaming and signal that they were in that lucid state during REM sleep. While they were immersed in lucid dreams, EMG sensors on their faces sent information from electrical impulses to the translation software. The results were uncertain. Based on attempts to translate planned phrases, Remmyo turned out to be anywhere from 13 to 81 percent effective, and in the interview, Raduga said he faced skepticism about the effectiveness of the translation software during the peer review process of his study, which is now published in the journal Psychology of Consciousness: Theory, Research and Practice. He still looks forward to making results more consistent by leveling up translation methods in the future. "The main problem is that it is hard to use only one muscle on your face to say something in Remmyo," said Raduga. "Unintentionally, people strain more than one muscle, and EMG sensors detect it all. Now we use only handwritten algorithms to overcome the problem, but we're going to use machine learning and AI to improve Remmyo decoding."

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Scientists Find Link Between Photosynthesis and 'Fifth State of Matter'

著者: BeauHD
2023年5月9日 19:00
Louise Lerner writes via Phys.Org: Inside a lab, scientists marvel at a strange state that forms when they cool down atoms to nearly absolute zero. Outside their window, trees gather sunlight and turn them into new leaves. The two seem unrelated -- but a new study from the University of Chicago suggests that these processes aren't so different as they might appear on the surface. The study, published in PRX Energy on April 28, found links at the atomic level between photosynthesis and exciton condensates -- a strange state of physics that allows energy to flow frictionlessly through a material. The finding is scientifically intriguing and may suggest new ways to think about designing electronics, the authors said. When a photon from the sun strikes a leaf, it sparks a change in a specially designed molecule. The energy knocks loose an electron. The electron, and the "hole" where it once was, can now travel around the leaf, carrying the energy of the sun to another area where it triggers a chemical reaction to make sugars for the plant. Together, that traveling electron-and-hole-pair is referred to as an "exciton." When the team took a birds-eye view and modeled how multiple excitons move around, they noticed something odd. They saw patterns in the paths of the excitons that looked remarkably familiar. In fact, it looked very much like the behavior in a material that is known as a Bose-Einstein condensate, sometimes known as "the fifth state of matter." In this material, excitons can link up into the same quantum state -- kind of like a set of bells all ringing perfectly in tune. This allows energy to move around the material with zero friction. (These sorts of strange behaviors intrigue scientists because they can be the seeds for remarkable technology -- for example, a similar state called superconductivity is the basis for MRI machines). According to the models [...], the excitons in a leaf can sometimes link up in ways similar to exciton condensate behavior. This was a huge surprise. Exciton condensates have only been seen when the material is cooled down significantly below room temperature. It'd be kind of like seeing ice cubes forming in a cup of hot coffee. "Photosynthetic light harvesting is taking place in a system that is at room temperature and what's more, its structure is disordered -- very unlike the pristine crystallized materials and cold temperatures that you use to make exciton condensates," explained [study co-author Anna Schouten]. This effect isn't total -- it's more akin to "islands" of condensates forming, the scientists said. "But that's still enough to enhance energy transfer in the system," said Sager-Smith. In fact, their models suggest it can as much as double the efficiency. The findings open up some new possibilities for generating synthetic materials for future technology, said study co-author Prof. David Mazziotti. "A perfect ideal exciton condensate is sensitive and requires a lot of special conditions, but for realistic applications, it's exciting to see something that boosts efficiency but can happen in ambient conditions."

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Gene Editing Makes Bacteria-killing Viruses Even More Deadly

著者: msmash
2023年5月9日 04:20
An anonymous reader shares a report: Broad-spectrum antibiotics are akin to nuclear bombs, obliterating every prokaryote they meet. They're effective at eliminating pathogens, sure, but they're not so great for maintaining a healthy microbiome. Ideally, we need precision antimicrobials that can target only the harmful bacteria while ignoring the other species we need in our bodies, leaving them to thrive. Enter SNIPR BIOME, a Danish company founded to do just that. Its first drug -- SNIPR001 -- is currently in clinical trials. The drug is designed for people with cancers involving blood cells. The chemotherapy these patients need can cause immunosuppression along with increased intestinal permeability, so they can't fight off any infections they may get from bacteria that escape from their guts into their bloodstream. The mortality rate from such infections in these patients is around 15-20 percent. Many of the infections are caused by E. coli, and much of this E. coli is already resistant to fluoroquinolones, the antibiotics commonly used to treat these types of infections. The team at SNIPR BIOME engineers bacteriophages, viruses that target bacteria, to make them hyper-selective. They started by screening 162 phages to find those that would infect a broad range of E. coli strains taken from people with bloodstream or urinary tract infections, as well as from the guts of healthy people. They settled on a set of eight different phages. They then engineered these phages to carry the genes that encode the CRISPR DNA-editing system, along with the RNAs needed to target editing to a number of essential genes in the E. coli genome. This approach has been shown to prevent the evolution of resistance. After testing the ability of these eight engineered phages to kill the E. coli panel alone and in combination, they decided that a group of four of them was the most effective, naming the mixture SNIPR001. But four engineered phages do not make a drug; the team confirmed that SNIPR001 remains stable for five months in storage and that it does not affect any other gut bacteria.

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Cosmic-Ray Muons Used to Detect Underground Tombs In Naples

著者: EditorDavid
2023年5月8日 02:34
Slashdot reader Bruce66423 shared this report from LiveScience: Cosmic rays and lasers have revealed that deep underneath the city streets of Naples, Italy, lie the remains of the Greeks who originally settled the area, as well as the catacombs of Christians who lived there during the Roman era nearly two millennia ago, a new study finds... The layers of contemporary buildings make it difficult to access ancient sewers, cisterns and tombs 33 feet (10 meters) underneath the streets, so a group of Italian and Japanese researchers hypothesized that they could identify previously unknown burial hypogea from the Hellenistic period using 21st-century techniques. Their study, published April 3 in the journal Scientific Reports, details how they used muography to detect underground voids that were unknown to archaeologists... In 1936, scientists discovered that muons are produced by cosmic rays in Earth's atmosphere, and that these tiny particles can easily penetrate walls and rocks, scattering in open spaces. In this study, the muons' tracks were recorded using nuclear emulsion technology, in which extremely sensitive photographic film is used to capture and visualize the paths of the charged particles. By measuring muon flux — how many muons arrive in a particular area over time — and direction using a particle detector, researchers can peer into volcanoes, underground cavities and even the Egyptian pyramids through muography... Valeri Tioukov, a physicist at Italy's National Institute for Nuclear Physics, and his colleagues placed the muon tracking devices 59 feet (18 m) underground, in a 19th-century cellar that was used for aging ham, where they recorded the muon flux for 28 days, capturing about 10 million muons... 3D laser scans of the accessible structures can then be compared with the measured muon flux. Anomalies in the muon flux images that are not visible in the 3D model can be confidently assumed to be hidden or unknown cavities. Muography revealed an excess of muons in the data that can be explained only by the presence of a new burial chamber. The chamber's area measures roughly 6.5 by 11.5 feet (2 by 3.5 m), according to the study, and its rectangular shape indicates it is human-made rather than natural.

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Brazilian Frog Might Be the First Pollinating Amphibian Known To Science

著者: BeauHD
2023年5月6日 12:30
An anonymous reader quotes a report from Science Magazine: The creamy fruit and nectar-rich flowers of the milk fruit tree are irresistible to Xenohyla truncata, a tree frog native to Brazil. On warm nights, the dusky-colored frogs take to the trees en masse, jostling one another for a chance to nibble the fruit and slurp the nectar. In the process, the frogs become covered in sticky pollen grains -- and might inadvertently pollinate the plants, too. It's the first time a frog -- or any amphibian -- has been observed pollinating a plant, researchers reported last month in Food Webs. Scientists long thought only insects and birds served as pollinators, but research has revealed that some reptiles and mammals are more than up to the task. Now, scientists must consider whether amphibians are also capable of getting the job done. It's likely that the nectar-loving frogs, also known as Izecksohn's Brazilian tree frogs, are transferring pollen as they move from flower to flower, the authors say. But more research is needed, they add, to confirm that frogs have joined the planet's pantheon of pollinators.

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Fungal Attacks Threaten Global Food Supply, Say Experts

著者: BeauHD
2023年5月4日 12:30
An anonymous reader quotes a report from The Guardian: Fast-rising fungal attacks on the world's most important crops threaten the planet's future food supply, scientists have said, warning that failing to tackle fungal pathogens could lead to a "global health catastrophe." Fungi are already by far the biggest destroyer of crops. They are highly resilient, travel long distances on the wind and can feast on large fields of a single crop. They are also extremely adaptable and many have developed resistance to common fungicides. The impact of fungal disease is expected to worsen, the researchers say, as the climate crisis results in temperatures rising and fungal infections moving steadily polewards. Since the 1990s, fungal pathogens have been moving to higher latitudes at a rate of about 7km a year. Wheat stem rust infections, normally found in the tropics, have already been reported in England and Ireland. Higher temperatures also drive the emergence of new variants of the fungal pathogens, while more extreme storms can spread their spores further afield, the scientists say. The scientists said there was also a risk that global heating would increase the heat tolerance of fungi, raising the possibility of them hopping hosts to infect warm-blooded animals and humans. The warning, issued in an article in the scientific journal Nature, said growers already lost between 10% and 23% of their crops to fungal disease. Across the five most important crops -- rice, wheat, maize, soya beans and potatoes -- infections cause annual losses that could feed hundreds of millions of people. Fungi made up the top six in a recent list of pests and pathogens with the biggest impact. Fungi are incredibly resilient, the researchers say, remaining viable in soil for up to 40 years, and their airborne spores can travel between continents. Fungicides are widely used but the pathogens are well equipped to rapidly evolve resistance to treatments that target only a single cellular process. Existing fungicides and conventional breeding for disease resistance are no longer enough, the researchers say. One solution is planting seed mixtures that carry a range of genes that are resistant to fungal infection, rather than monocultures of a single strain. In 2022, about a quarter of wheat in Denmark was grown in this way. Technology may also help, the scientists say, with drones and artificial intelligence allowing earlier detection and control of outbreaks. New pesticides are being developed, with a team at the University of Exeter recently discovering compounds that could lead to chemicals that target several biological processes within the fungi, making resistance much harder to develop. The approach has already been shown to be useful against fungi infecting wheat, rice, corn and bananas. "While that storyline is science fiction, we are warning that we could see a global health catastrophe caused by the rapid global spread of fungal infections," said Sarah Gurr, professor at the University of Exeter and co-author of the report. "The imminent threat here is not about zombies, but about global starvation."

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Scientists in India Protest Move To Drop Darwinian Evolution From Textbooks

著者: msmash
2023年5月3日 02:20
Scientists in India are protesting a decision to remove discussion of Charles Darwin's theory of evolution from textbooks used by millions of students in ninth and 10th grades. More than 4000 researchers and others have so far signed an open letter asking officials to restore the material. From a report: The removal makes "a travesty of the notion of a well-rounded secondary education," says evolutionary biologist Amitabh Joshi of the Jawaharlal Nehru Centre for Advanced Scientific Research. Other researchers fear it signals a growing embrace of pseudoscience by Indian officials. The Breakthrough Science Society, a nonprofit group, launched the open letter on 20 April after learning that the National Council of Educational Research and Training (NCERT), an autonomous government organization that sets curricula and publishes textbooks for India's 256 million primary and secondary students, had made the move as part of a "content rationalization" process. NCERT first removed discussion of Darwinian evolution from the textbooks at the height of the COVID-19 pandemic in order to streamline online classes, the society says. (Last year, NCERT issued a document that said it wanted to avoid content that was "irrelevant" in the "present context.") NCERT officials declined to answer questions about the decision to make the removal permanent. They referred ScienceInsider to India's Ministry of Education, which had not provided comment as this story went to press.

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'Game Changer' Method Lets Scientists Peer Into -- and Fly Through -- Mouse Bodies

著者: BeauHD
2023年4月27日 16:00
sciencehabit shares a report from Science Magazine: A research team has turned the bodies of dead mice into vivid 3D maps of anatomy, with tissues, nerves, and vessels highlighted in color. The technique, which renders the corpses transparent and then exposes them to fluorescent antibodies that label distinct cell types, could help everything from drug development to understanding the spread of cancer, its creators and other scientists say. The developers, at the Helmholtz Munich research institute, call their technique wildDISCO -- wild because it can work on any "wild type," or normal, mice, and DISCO for 3D imaging of solvent-cleared organs. Building on their previous success at making mouse bodies transparent, the new technique removes cholesterol from the bodies so that a vast array of existing antibodies can penetrate deep into the animals. "wildDISCO is a game changer -- it allows us to see the hidden highways and byways in the body," says Muzlifah Haniffa, a dermatologist and immunologist at the Wellcome Sanger Institute and Newcastle University's Biosciences Institute who was not involved in the research. The method should let scientists map a mouse at the cellular level and explore previously hidden links between tissues, like neural connections between organs, says neuroscientist Ali Erturk, director of Helmholtz Munich, who led the work, posted recently as a preprint. His group in Germany has already posted eye-catching videos of "flying" through the 3D anatomy of a mouse with different tissues labeled.

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Moths Are More Efficient Pollinators Than Bees, Shows New Research

著者: BeauHD
2023年4月25日 11:02
According to new research published last month in PLOS ONE, moths are more efficient pollinators at night than day-flying pollinators such as bees. Phys.Org reports: Studying 10 sites in the South East of England throughout July 2021, [researchers from the University of Sussex] found that 83% of insect visits to bramble flowers were made during the day. While the moths made fewer visits during the shorter summer nights, notching up only 15% of the visits, they were able to pollinate the flowers more quickly. As a result, the researchers concluded that moths are more efficient pollinators than day-flying insects such as bees, which are traditionally thought of as "hard-working." While day-flying insects have more time available to transfer pollen, moths were making an important contribution during the short hours of darkness. Professor Fiona Mathews, Professor of Environmental Biology at the University of Sussex and co-author this latest research, says, "Bees are undoubtedly important, but our work has shown that moths pollinate flowers at a faster rate than day-flying insects. Sadly, many moths are in serious decline in Britain, affecting not just pollination but also food supplies for many other species ranging from bats to birds. Our work shows that simple steps, such as allowing patches of bramble to flower, can provide important food sources for moths, and we will be rewarded with a crop of blackberries. Everyone's a winner!"

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Scientists Identify Mind-Body Nexus In Human Brain

著者: BeauHD
2023年4月20日 12:30
An anonymous reader quotes a report from Reuters: Researchers said on Wednesday they have discovered that parts of the brain region called the motor cortex that govern body movement are connected with a network involved in thinking, planning, mental arousal, pain, and control of internal organs, as well as functions such as blood pressure and heart rate. They identified a previously unknown system within the motor cortex manifested in multiple nodes that are located in between areas of the brain already known to be responsible for movement of specific body parts -- hands, feet and face -- and are engaged when many different body movements are performed together. The researchers called this system the somato-cognitive action network, or SCAN, and documented its connections to brain regions known to help set goals and plan actions. This network also was found to correspond with brain regions that, as shown in studies involving monkeys, are connected to internal organs including the stomach and adrenal glands, allowing these organs to change activity levels in anticipation of performing a certain action. That may explain physical responses like sweating or increased heart rate caused by merely pondering a difficult future task, they said. "Basically, we now have shown that the human motor system is not unitary. Instead, we believe there are two separate systems that control movement," said radiology professor Evan Gordon of the Washington University School of Medicine in St. Louis, lead author of the study. "One is for isolated movement of your hands, feet and face. This system is important, for example, for writing or speaking -movements that need to involve only the one body part. A second system, the SCAN, is more important for integrated, whole body movements, and is more connected to high-level planning regions of your brain," Gordon said. "Modern neuroscience does not include any kind of mind-body dualism. It's not compatible with being a serious neuroscientist nowadays. I'm not a philosopher, but one succinct statement I like is saying, 'The mind is what the brain does.' The sum of the bio-computational functions of the brain makes up 'the mind,'" said study senior author Nico Dosenbach, a neurology professor at Washington University School of Medicine. "Since this system, the SCAN, seems to integrate abstract plans-thoughts-motivations with actual movements and physiology, it provides additional neuroanatomical explanation for why 'the body' and 'the mind' aren't separate or separable." The findings have been published in the journal Nature.

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The Fascinating and Evolving Story of Bacteria and Cancer

著者: msmash
2023年4月19日 03:25
Dr Eric Topol, a cardiologist and director of the Scripps Translational Science Institute, writing over the weekend: It was medical dogma: cancer tissue is sterile. That's what we had learned and taught in medical school for decades even though bacteria were detected in tumors more than 100 years ago. When studies were reported asserting that bacteria were present in tumor tissue, they were consistently debunked as representing contaminants. Then came new tools that include single-cell sequencing and sophisticated spatial profiling providing high-resolution portraits of tumors. The new dogma is that bacteria have a pervasive (yet variable) presence within and across solid tumors -- the "presence of intratumoral bacteria being designated a hallmark of cancer." Furthermore, where bacteria are more apt to be found within tumor regions, T cell recruitment and function is suppressed. These regions of tumor are micro-niches exhibiting immune evasion. Just as that has been determined, there was a new twist this week: engineering bacteria to induce a potent T cell immune response to kill the tumor. This can be viewed as the polar opposite. Instead of bacteria improving a tumor's ability to duck our immune response and spread, this represents clever ways to genetically manipulate bacteria (aka "designer bugs" with the schematic in the linked post) to make it considerably more antigenic, a new route to immunotherapy.

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Scientists Discover 1st 'Neutron-Rich' Isotope of Uranium Since 1979

著者: BeauHD
2023年4月18日 22:00
An anonymous reader quotes a report from Live Science: Scientists have discovered and synthesized an entirely new isotope of the highly radioactive element uranium. But it might last only 40 minutes before decaying into other elements. The new isotope, uranium-241, has 92 protons (as all uranium isotopes do) and 149 neutrons, making it the first new neutron-rich isotope of uranium discovered since 1979. While atoms of a given element always have the same number of protons, different isotopes, or versions, of those elements may hold different numbers of neutrons in their nuclei. To be considered neutron-rich, an isotope must contain more neutrons than is common to that element. "We measured the masses of 19 different actinide isotopes with a high precision of one part per million level, including the discovery and identification of the new uranium isotope," Toshitaka Niwase(opens in new tab), a researcher at the High-energy Accelerator Research Organization (KEK) Wako Nuclear Science Center (WNSC) in Japan, told Live Science in an email. "This is the first new discovery of a uranium isotope on the neutron-rich side in over 40 years." Niwase is the lead author of a study on the new uranium isotope, which was published March 31 in the journal Physical Review Letters. Niwase and colleagues created the uranium-241 by firing a sample of uranium-238 at platinum-198 nuclei at Japan's RIKEN accelerator. The two isotopes then swapped neutrons and protons — a phenomenon called "multinucleon transfer." The team then measured the mass of the created isotopes by observing the time it took the resulting nuclei to travel a certain distance through a medium. The experiment also generated 18 new isotopes, all of which contained between 143 and 150 neutrons.

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Scientists Create Eco-Friendly Paint That Keeps the Surface Beneath Cool

著者: BeauHD
2023年4月14日 11:02
A team of researchers in Florida have created a way to mimic nature's ability to reflect light and create beautifully vivid color without absorbing any heat like traditional pigments do. Debashis Chanda, a nanoscience researcher with the University of Central Florida, and his team published their findings in the journal Science Advances. NPR reports: Beyond just the beautiful arrays of color that structure can create, Chanda also found that unlike pigments, structural paint does not absorb any infrared light. Infrared light is the reason black cars get hot on sunny days and asphalt is hot to the touch in summer. Infrared light is absorbed as heat energy into these surfaces -- the darker the color, the more the surface colored with it can absorb. That's why people are advised to wear lighter colors in hotter climates and why many buildings are painted bright whites and beiges. Chanda found that structural color paint does not absorb any heat. It reflects all infrared light back out. This means that in a rapidly warming climate, this paint could help communities keep cool. Chanda and his team tested the impact this paint had on the temperature of buildings covered in structural paint versus commercial paints and they found that structural paint kept surfaces 20 to 30 degrees cooler. This, Chanda said, is a massive new tool that could be used to fight rising temperatures caused by global warming while still allowing us to have a bright and colorful world. Unlike white and black cars, structural paint's ability to reflect heat isn't determined by how dark the color is. Blue, black or purple structural paints reflect just as much heat as bright whites or beige. This opens the door for more colorful, cooler architecture and design without having to worry about the heat. It's not just cleaner, Chanda said. Structural paint weighs much less than pigmented paint and doesn't fade over time like traditional pigments. "A raisin's worth of structural paint is enough to cover the front and back of a door," he said. Unlike pigments which rely on layers of pigment to achieve depth of color, structural paint only requires one thin layer of particles to fully cover a surface in color. This means that structural paint could be a boon for aerospace engineers who rely on the lowest weight possible to achieve higher fuel efficiency. The possibilities for structural paint are endless and Chanda hopes that cans of structural paint will soon be available in hardware stores.

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Physicists Extend Qubit Lifespan In Pivotal Validation of Quantum Computing

著者: BeauHD
2023年4月11日 12:30
An anonymous reader quotes a report from ScienceAlert: Keeping enough qubits in their ideal state long enough for computations has so far proved a challenge. In a new experiment, scientists were able to keep a qubit in that state for twice as long as normal. Along the way, they demonstrated the practicality of quantum error correction (QEC), a process that keeps quantum information intact for longer by introducing room for redundancy and error removal. The idea of QEC has been around since the mid-90s, but it's now been shown to work in real time. Part of the reason for the experiment's success was the introduction of machine learning AI algorithms to tweak the error correction routine. "For the first time, we have shown that making the system more redundant and actively detecting and correcting quantum errors provided a gain in the resilience of quantum information," says physicist Michel Devoret, from Yale University in Connecticut. [...] Like many quantum physics experiments, this one was run at ultra-cold temperatures -- a hundred times colder than outer space, in this case. The setup has to be carefully controlled in order to protect the qubit as much as possible. The error-corrected qubit lasted for 1.8 milliseconds -- only a blink as we might experience it, but an impressive span for a qubit operating on the quantum level. Now the research team will be able to refine the process further. "Our experiment shows that quantum error correction is a real practical tool," says Devoret. "It's more than just a proof-of-principle demonstration." In this case the breakthrough was down to several different factors, rather than one change. The QEC code was actually one from 2001, but improvements to it as well as upgrades to the quantum circuit fabrication process made a difference. "Our experiment validates a cornerstone assumption of quantum computing, and this makes me very excited about the future of this field," says Volodymyr Sivak, a research scientist at Google and formerly at Yale University. The research has been published in Nature.

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False Memories Can Form Within Seconds, Study Finds

著者: BeauHD
2023年4月6日 10:25
In a new study, scientists found that it's possible for people to form false memories of an event within seconds of it occurring. This almost-immediate misremembering seems to be shaped by our expectations of what should happen, the team says. Gizmodo reports: "This study is unique in two ways, in our opinion. First, it explores memory for events that basically just happened, between 0.3 and 3 seconds ago. Intuitively, we would think that these memories are pretty reliable," lead author Marte Otten, a neuroscientist at the University of Amsterdam, told Gizmodo in an email. "As a second unique feature, we explicitly asked people whether they thought their memories are reliable -- so how confident are they about their response?" To do this, they recruited hundreds of volunteers over a series of four experiments to complete a task: They would look at certain letters and then be asked to recall one highlighted letter right after. However, the scientists used letters that were sometimes reversed in orientation, so the volunteers had to remember whether their selection was mirrored or not. They also focused on the volunteers who were highly confident about their choices during the task. Overall, the participants regularly misremembered the letters, but in a specific way. People were generally good at remembering when a typical letter was shown, with their inaccuracy rates hovering around 10%. But they were substantially worse at remembering a mirrored letter, with inaccuracy rates up to 40% in some experiments. And, interestingly enough, their memory got worse the longer they had to wait before recalling it. When they were asked to recall what they saw a half second later, for instance, they were wrong less than 20% of the time, but when they were asked three seconds later, the rate rose as high as 30%. According to Otten, the findings -- published Wednesday in PLOS One -- indicate that our memory starts being shaped almost immediately by our preconceptions. People expect to see a regular letter, and don't get easily fooled into misremembering a mirrored letter. But when the unexpected happens, we might often still default to our missed prediction. This bias doesn't seem to kick in instantaneously, though, since people's short-term memory was better when they had to be especially quick on their feet. "It is only when memory becomes less reliable through the passage of a tiny bit of time, or the addition of extra visual information, that internal expectations about the world start playing a role," Otten said.

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Physicists Created 'Slits In Time' and Discovered 'Unexpected Physics'

著者: BeauHD
2023年4月4日 12:30
An anonymous reader quotes a report from Motherboard: Scientists have discovered "unexpected physics" by opening up "slits" in time, a new study reports, achieving a longstanding dream that can help to probe the behavior of light and pioneer advanced optical technologies. The mind-boggling approach is a time-based variation on the famous double-slit experiment, first performed by Thomas Young in 1801, which opened a window into the weird probabilistic world of quantum mechanics by revealing the dual nature of light as both a particle and a wave. The new temporal version of this test offered a glimpse of the mysterious physics that occur at ultrafast timescales, which may inform the development of quantum computing systems, among other next-generation applications. In the original version of the double-slit experiment, light passes through two slits that are spatially separated on an opaque screen. A detector on the other side of the screen records the pattern of the light waves that emerges from the slits. These experiments show that the light waves change direction and interfere with each other after going through the slits, demonstrating that light behaves as both a wave and particle. This insight is one of the most important milestones in our ongoing journey into the quantum world, and it has since been repeated with other entities, such as electrons, exposing the trippy phenomena that occurs at the small scales of atoms. Now, scientists led by Romain Tirole, a PhD student studying nanophotonics at Imperial College London, have created a "temporal analogue of Young's slit experiment" by firing a beam of light at a special metamaterial called Indium Tin Oxide, according to a study published on Monday in Nature Physics. Metamaterials are artificial creations endowed with superpowers that are not found in nature. For instance, the Indium Tin Oxide used in the new study can change its properties in mere femtoseconds, a unit equal to a millionth of a billionth of a second. This incredible variability allows light waves to interact with the metamaterial at key moments in ultrafast succession, called "time slits," which produces a time-based diffraction pattern that is analogous to the results returned in the spatial version of the experiment. [...] In other words, the super-speedy changeability of Indium Tin Oxide finally made a time slit experiment possible, after many years of eluding scientists. To bring this vision to reality, Tirole and his colleagues used lasers to switch the reflectance of the material on and off at high speeds.

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Could a Photosynthesis 'Hack' Lead to New Ways of Generating Renewable Energy?

著者: EditorDavid
2023年4月3日 05:09
"Researchers have 'hacked' the earliest stages of photosynthesis," according to a new announcement from the University of Cambridge. CNET reports: Scientists have studied photosynthesis in plants for centuries, but an international team believes they've unlocked new secrets in nature's great machine that could revolutionize sustainable fuels and fight climate change. The team says they've determined it's possible to extract an electrical charge at the best possible point in photosynthesis. This means harvesting the maximum amount of electrons from the process for potential use in power grids and some types of batteries. It could also improve the development of biofuels. While it's still early days, the findings, reported in the journal Nature, could reduce greenhouse gasses in the atmosphere and provide insights to improve photovoltaic solar panels. The key breakthrough came when researchers observed the process of photosynthesis at ultrafast timescales. "We can take photos at different times which allow us to watch changes in the sample really, really quickly — a million billion times faster than your iPhone," Dr. Tomi Baikie, from the University of Cambridge's Cavendish Laboratory, told CNET.... Previous demonstrations connected cyanobacteria, algae and other plants to electrodes to create so-called bio-photoelectrochemical cells that tap into the photosynthetic process to generate electricity. Baikie said they were surprised to discover a previously unknown pathway of energy flow at the beginning of the process that could enable extracting the charge in a more efficient way.

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Stressed Plants Emit Sounds That Can Be Detected More Than a Meter Away

著者: BeauHD
2023年3月31日 12:30
An anonymous reader quotes a report from Phys.Org: What does a stressed plant sound like? A bit like bubble-wrap being popped. Researchers in Israel report in the journal Cell on March 30 that tomato and tobacco plants that are stressed -- from dehydration or having their stems severed -- emit sounds that are comparable in volume to normal human conversation. The frequency of these noises is too high for our ears to detect, but they can probably be heard by insects, other mammals, and possibly other plants. "Even in a quiet field, there are actually sounds that we don't hear, and those sounds carry information," says senior author Lilach Hadany, an evolutionary biologist and theoretician at Tel Aviv University. "There are animals that can hear these sounds, so there is the possibility that a lot of acoustic interaction is occurring." The researchers used microphones to record healthy and stressed tomato and tobacco plants, first in a soundproofed acoustic chamber and then in a noisier greenhouse environment. They stressed the plants via two methods: by not watering them for several days and by cutting their stems. After recording the plants, the researchers trained a machine-learning algorithm to differentiate between unstressed plants, thirsty plants, and cut plants. The team found that stressed plants emit more sounds than unstressed plants. The plant sounds resemble pops or clicks, and a single stressed plant emits around 30-50 of these clicks per hour at seemingly random intervals, but unstressed plants emit far fewer sounds. "When tomatoes are not stressed at all, they are very quiet," says Hadany. Water-stressed plants began emitting noises before they were visibly dehydrated, and the frequency of sounds peaked after five days with no water before decreasing again as the plants dried up completely. The types of sound emitted differed with the cause of stress. The machine-learning algorithm was able to accurately differentiate between dehydration and stress from cutting and could also discern whether the sounds came from a tomato or tobacco plant. Although the study focused on tomato and tobacco plants because of their ease to grow and standardize in the laboratory, the research team also recorded a variety of other plant species. "We found that many plants -- corn, wheat, grape, and cactus plants, for example -- emit sounds when they are stressed," says Hadany. The researchers suggest that these noises "might be due to the formation and bursting of air bubbles in the plant's vascular system, a process called cavitation," reports Phys.Org. It's unclear if the plants are producing these sounds in order to communicate with other organisms.

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