Gluons are the quantum 'Gorilla Glue' involved in binding quarks together, ScienceAlert reminds us. But for nearly 50 years, physicists have hunted for "glueballs", exotic particles predicted by this theory of the strong interaction — the only type of particle in nature composed entirely of force mediators: Now, a collaboration working at a collider in Beijing says it has the clearest evidence yet that a known particle called X(2370) is dominated by one of these elusive states... Physicists sifted through the wreckage of high-energy particle collisions to find strong evidence of this glueball, made predominantly of gluons — massless force carriers of the strong interaction between quarks... The new evidence for this exotic, unstable glueball's ephemeral existence comes from a recent preprint on arXiv, presented at the International Conference on High Energy Physics in Brazil... This collaboration uses the Beijing Electron Positron Collider II, a particle accelerator and collider that smashes electrons into their antimatter counterparts, called positrons, to probe perplexing particle physics. The resultant glueball is an "unprecedented form of matter," says Jin Shan, a particle physicist at Nanjing University and one of the research team's leaders. "It not only enables the theory describing strong interactions to pass its most rigorous test, but also vastly expands the boundaries of our understanding of the physical world," he told Fan Chen at South China Morning Post... Previously, in a study published in the journal Physical Review Letters in 2024, the researchers analyzed 10 billion meson decay events. They measured the X(2370) particle's mass and spin parity — a property that dictates its interactions and almost-instantaneous decay — for the first time, finding complete agreement between their experimental values and predictions. Now, they've identified its additional decay modes and determined its flavor-singlet nature, "the most important characteristic of a glueball...." The authors describe their work as the clearest experimental result to emerge from nearly 50 years of glueball searches, supporting the long-standing theoretical prediction that gluons can bind together into a new form of matter. The discovery ""highlights advances in technology and analytical techniques that have recently revealed another decades-in-the-making physics mystery," the article points out. "More experiments are needed to further confirm and constrain the prototypes of the highly esoteric glueball; in other words, more particle smashing."

Read more of this story at Slashdot.

Phys.org reports: Future fusion power plants aim to recreate the heart of a star here on Earth to power our future energy needs. While the core fusion plasma will burn at hundreds of millions of degrees, the surrounding structural components must handle sudden, punishing heat loads that rival the extreme temperatures faced by spacecraft upon reentry into Earth's atmosphere. Copper and its alloys are primary candidates for handling these intense heat fluctuations, making it vital to understand exactly how the metal behaves when pushed to its melting point. Now, researchers at the Department of Energy's SLAC National Accelerator Laboratory and collaborators have captured a detailed, step-by-step look at copper atoms as they underwent extreme heating. Published in Nature Communications, the results revealed a key parameter that allowed copper's crystal lattice to melt steadily rather than collapse instantaneously, as earlier simulations predicted. "These results greatly improve the simulations we use to predict which materials have the best shot at surviving the extreme conditions of future fusion reaction chambers," said Mianzhen Mo, a SLAC staff scientist who led the research. "They also demonstrate the incredible, atomic-scale resolution imaging we can achieve at SLAC's electron camera...." Researchers use computer simulations, aided by AI and machine learning, to sift through innumerable combinations of elements and identify promising candidate materials for real-world testing. "Whether the copper melts slowly or suddenly collapses, by the time the researchers look, the sample resembles nothing more than a metallic brown puddle," the article points out. But SLAC's powerful electron camera captures atomic and molecular movements down to the femtosecond — a millionth of a billionth of a second — and revealed that at around 1,424 degreesC (2,595 degreesF) there was still gradual melting as the temperature rose beyond the superheating limit, with real-world conditions showing the atoms shifted and retained some order. "It's a straightforward solution," said Mianzhen Mo, a SLAC staff scientist who led the research. "But molecular dynamics simulations had been overlooking it for years. When you have complex simulations attempting to capture every aspect of reality, down to individual atoms, it takes real-world data to show you what's missing from the calculations."

Read more of this story at Slashdot.

sciencehabit shares a report from Science Magazine: For more than half a century, physicists have searched for one of the strangest particles predicted by modern theory. It would be made almost entirely of gluons, the elusive subatomic particles that carry the strong nuclear force. Now, using a particle collider in Beijing, researchers say they have effectively proved the existence of such a "glueball." In a preprint posted last month on arXiv and in a presentation last week at the International Conference on High Energy Physics (ICHEP), the researchers argue that a particle called X(2370), which they produced by smashing electrons into positrons at high energies, has the properties expected of a glueball. "It's an experimental triumph," says Colin Morningstar, a particle physicist at Carnegie Mellon University who was not involved in the finding. "It's the strongest evidence yet that particles dominated by a glueball component can exist in nature."

Read more of this story at Slashdot.

Researchers in China have developed a living mycelium textile that can self-clean, renew its surface, and partially repair holes when treated with a nutrient solution and fresh fungus. The material can also gain added properties such as blue pigmentation or UV resistance by co-culturing it with yeast or other fungi. Dezeen reports: The breakthrough from the researchers at the Shenzhen Institutes of Advanced Technology is a type of engineered living material (ELM) -- a material built off living organisms that stay active even after they're fabricated into their final form. [...] By working with living but dormant cordyceps militaris fungus instead, the researchers have been able to take advantage of its biological functions. The result is a material that is self-renewing and responsive to its environment, in ways that could one day transform architecture and clothing -- as seen in a prototype dress created together with material innovation company Peelshere. It can also be adapted by mixing in other fungi or yeast, lead researcher Ke Li and her team detail in a paper in the peer-reviewed journal Science Advances. In it, they describe a "programmable fungal platform" where mycelium is treated like a modular system, with the sheet material forming a base structure and extra biological abilities, such as colour and UV resistance, becoming "plug-and-play" add-ons via other organisms. This gets their textile closer to the self-repair, environmental responsiveness and controllable functionality that is the promise of engineered living materials, they argue. The ELM's self-renewing and semi-repairing functionality comes from the mycelium base structure. Following drying at 45 degrees, the material is not quite living and not quite dead, but instead in a "low-metabolic, dormant-like state", Li told Dezeen, meaning it is not actively growing. However, new growth can be triggered by applying a nutrient solution of potato water, leading the dormant mycelium to germinate, send out new fungal filaments and renew the material's surface. When this nutrient solution is applied over a hole, along with a small patch of fresh fungus, it triggers the living cells to grow across the gap, seamlessly repairing the surface without any adhesives or stitching. The material is also naturally self-cleaning, as it is hydrophobic. "Its distinctive surface texture, biological colouring, controlled repair and biodegradability may be particularly useful in applications where visual expression and a defined product lifetime are important," said Li. "Further improvements in durability, moisture resistance, safety and manufacturing consistency would be needed before it could be considered for routine clothing or permanent architectural use."

Read more of this story at Slashdot.

"A major scientific review is challenging the idea that more protein is always better," reports ABC News: The review, led by pathologist and biomedical researcher Dudley Lamming and published in the journal Cell Press Blue, examined more than 350 studies involving humans, mice, insects, yeast, and other organisms. The review found that eating less protein, or less of certain amino acids that make up protein, may turn on body processes linked to healthier aging, as well as metabolism, the process by which the body turns food and drinks into energy... For adults who already get enough, eating more protein may offer little benefit, while some research suggests that eating less protein could support healthier aging... Lamming reviewed the effect of reducing protein in many body processes. One of the processes involves a hormone called FGF21. "There's an increase in a hormone called FGF21 that promotes energy expenditure [when protein intake is reduced]," Lamming said. "It essentially increases thermogenesis in your adipose tissue, so you don't just store fat, but actually burn it as fuel." This may help explain why some studies connect lower-protein diets with less body fat, better blood sugar control and a healthier metabolism. Eating less protein may also affect signals that tell cells when to grow, repair damage or recycle old cell parts. These jobs may play a role in aging. However, protein restriction is not the same as protein deficiency. The goal is not to deprive the body of an essential nutrient. Instead, the research raises the possibility that avoiding unnecessary excess could benefit some people who already consume enough... Before reaching for another high-protein product, a better question may be: How much protein does my body actually need?

Read more of this story at Slashdot.

alternative_right shares a report from ScienceAlert: A study published in PLOS One in 2021 by researchers from Durham University in the UK showed that with 10 weeks of training, both blind and sighted people could learn to echolocate using verbal clicks. While the technique is already used by a number of people with impaired vision -- sometimes using the taps of a cane instead of clicks made by their mouth -- those findings suggest that many of us can learn the necessary techniques. Some of the same researchers who made that discovery are part of the team behind a follow-up study published in Cerebral Cortex, looking at how the 10 weeks of training that the 26 participants went through actually changed the physical structure of their brains. Specifically, the team analyzed brain scans of the V1 (the primary visual cortex, processing visuals), and the A1 (the primary auditory cortex, processing sounds). Strikingly, the scans showed that the V1s of both blind and sighted people had developed sensitivity to sound echoes during echolocation training.

Read more of this story at Slashdot.

An anonymous reader quotes a report from CBC News: It's rare that cancerous tumors can spread from one individual to another. But a genetic study suggests that's what's happening with melanoma tumors among catfish in Quebec and the northeastern U.S. The discovery represents the first known transmissible cancer in fish and one of very few transmissible cancers ever found, reported the study published in the journal Nature on Wednesday. Julie Dragon, co-leader of the new study, noted that only three other transmissible cancers have ever been identified so far -- in Tasmanian devils, dogs and shellfish. "These conditions are incredibly rare in nature," she said. "So something has to be happening to allow this to happen." Anglers in Lake Memphremagog, which spans the border between Quebec and Vermont, first reported catching brown bullhead catfish with strange black spots and lumps in 2012. They turned out to be melanoma skin cancer tumors. (Humans can also get this kind of cancer.) Now, about a third of the brown bullheads living in the lake have them. It's not clear how sick the fish become. In some cases, the cancer spreads to other organs, such as the brain or liver. But many fish with lesions seem relatively healthy and some older fish even have them, suggesting they can live with the disease for a time. Because of the sudden appearance of the black lesions in Lake Memphremagog the year after a huge flood caused by post-tropical storm Irene, locals worried they were caused by carcinogens washed into the lake by floodwaters. Tests for carcinogens haven't been conclusive, although a study published in May found higher concentrations of seven metals, including zinc and the carcinogen arsenic, in the skin of fish with the tumors. Researchers suspect the tumors may spread among adult fish during spawning, when crowded fish rub against one another and may be punctured by their spines. "They... swim all over each other and we think it's possible that they poke each other and cells can get into other fish that way," Dragon said, though transmission has not yet been demonstrated.

Read more of this story at Slashdot.

A new study by researchers at the University of California at San Francisco "adds to growing research linking increased social media use to detrimental effects on attention, memory and cognition," reports the Washington Post: The study followed more than 11,000 U.S. adolescents over a period of five years, with participants first asked about their own social media use at the average age of 12, and surveyed annually through the average age of 16. Researchers found that increases in addictive social media use were followed by rising ADHD one year later — particularly among boys who reported rising addictive social media use at ages 14 and 15. This association was not found consistently in reverse, meaning that ADHD symptoms did not appear to precede higher levels of addictive social media use... "When an individual adolescent's addictive social media use score increased from one year to the next, that same adolescent tended to show an increase in ADHD symptoms in the following year...." [said Jason Nagata, lead author of the study and an associate professor of pediatrics at the University of California at San Francisco]. He urged parents to consider: "Can their kids stop if they want to? Is social media interfering with their schoolwork? Is it impairing their social relationships? Are there addiction-like symptoms, like withdrawal and relapse?" Approximately 7 million American children between the ages of 3 and 17 have received an ADHD diagnosis, according to the Centers for Disease Control and Prevention, and boys are diagnosed with ADHD at about twice the rate of girls. The study did not find a clear link between addictive social media use and ADHD among girls, Nagata said. "Some studies do suggest that teenage boys in particular may be more sensitive to immediate reward and sensation-seeking in adolescence," he said. And social media platforms are designed to provide exactly that: "It encourages frequent task-switching, and there's this constant stream of stimulation that might make it harder for adolescents to maintain and sustain attention that is needed for schoolwork and daily life," he said. "The design features of social media offer the constant reinforcement of impulsivity — it offers immediate gratification and novelty and it encourages multitasking, which can then override working memory and executive control." Experts have long noted that this kind of digital exposure is particularly significant during critical stages of mental, social-emotional and cognitive development... [I]t's especially important for parents themselves to demonstrate a healthier relationship with screens and social media. "One of our previous findings was that parental screen use is a very strong predictor of kids' screen use," Nagata said.

Read more of this story at Slashdot.

Le Japon a développé une méthode pour récupérer 90% du lithium dans les batteries des véhicules électriques.
(Permalink)

Voilà ce qui se passe quand on ne croit pas en la science...
(Permalink)