Longtime Slashdot reader fahrbot-bot shares a report from ScienceAlert: Scientists have now demonstrated one of the weirdest forms of ice yet -- under preposterous pressures up to 2.3 million atmospheres, and tremendous temperatures up to 2,630 kelvins (2,357 degrees Celsius, or 4,274 degrees Fahrenheit). [...] In their new experiments, a team led by physicist Alexis Forestier of the French Alternative Energies and Atomic Energy Commission subjected tiny samples of water to the sorts of extreme conditions expected in the interiors of ice giant planets. They squeezed the samples between the tips of diamonds to pressures as high as 230 gigapascals, while using lasers to heat them to thousands of degrees. That's 2.3 million times Earth's atmospheric pressure at sea level â" the pressure at the center of Earth, for context, is around 360 gigapascals. Then, using an extremely narrow beam of synchrotron X-rays, they probed for changes in the crystal structure of the ice. What emerged was a configuration predicted theoretically but never unambiguously observed in experiments: hexagonal close-packed, or hcp, ice. As the hcp crystal was heated, its expansion also showed a signature of superionic behavior, suggesting it entered the superionic state at around 1,700 kelvins. [Superionic ice is thought to exist deep inside Uranus and Neptune, where its unusual properties may play a role in generating the planets' equally unusual magnetic fields.] The findings have been published in Physical Review Letters.

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On entend beaucoup parler de cartes ces derniers temps (j'y reviendrai), mais voici une carte du monde vue par un topologiste, et je trouve ça très intéressant. Elle rend plus visibles les frontières communes entre les pays.
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Un mouvement ésotérique influence-t-il la lutte contre les pesticides ? Façonnée par plusieurs penseurs religieux, l'écologie politique partage avec lui une même défiance envers la technologie. Une convergence qui ouvre bien des portes, jusque dans la recherche publique...L’article La chimie, le grand Satan est apparu en premier sur Les Électrons Libres.

A team of researchers at Southern Illinois University Carbondale engineered yeast to create cookies that were 3D printed out of plastic waste, reports Futurism: The yeast breaks down the components of plastic compounds and agricultural byproducts like discarded plant stalks into proteins, fats, acids, and flavorings that we can eat. When these are combined together, the mixture is fed into a 3D printer that spits out cookies of any desired shape. The researchers chose to print their cookies as the Greek letter Â, creating what they call "ÂBites" — or micro bites. They haven't actually eaten one of their ÂBites yet, as they wait for university approval... "I think it has a pleasant, appealing aroma," Lahiru Jayakody, a microbiologist at SIU who led the research, told NewScientist. "And it will taste good, too. We've not tasted it, but it smells good — that's for sure — like a real cookie...." The researchers used CRISPR gene-editing technology to reprogram yeast strains to eat polyethylene terephthalate (PET), a widely used form of plastic commonly found in disposable water bottles, food packaging, and clothes, which is rich with carbon. Before the yeast can start feasting, the PET plastics are subjected to a process called oxidative hydrothermal dissolution to break them down into smaller bits that the microbes can digest. The purported advantage of this approach is that it's environmentally friendly, using only heat, water, and oxygen. The yeast feasts on these stripped-down plastic bits, turning them into a slurry of proteins, fats, and acids that're combined with fiber, starch, and sweetener to make them more palatable. One of the yeast strains in particular was able to turn plant biomass into tasty vanilla flavorings... [R]ight now, it's an expensive process, costing around $60 to produce a kilogram of cookies, The Guardian reported. And some experts say it's wishful thinking to believe we can 3D-print, and then eat, ourselves out of these global problems with 3D-printed, delectable treats. "We produce 400 million tons a year of plastic waste. You're not going to turn it all into cookies," Jason Hallett at Imperial College London told New Scientist. "So it's not a solution to the plastic-waste crisis. There's no way you could do this commercially. We're not gonna be eating plastic cookies." Thanks to Slashdot reader fjo3 for sharing the article.

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Superviseur de la méta-analyse de 2014, Carlo Leifert a une spécialité : trouver des vertus au bio là où les autres n'en voient pas. De son premier coup d'éclat en 2007 à son récent virage épidémiologique, plongée dans un parcours jalonné de vives controverses.L’article Carlo Leifert, une carrière à science unique sous le signe du bio est apparu en premier sur Les Électrons Libres.

Haha c'est génial ! 😂

Contexte : Dans le traitement d'images, surtout dans la littérature scientifique, on utilise des images de référence afin de comparer les algorithmes.
Or il y a une image de référence que TOUT LE MONDE utilise depuis plus de 30 ans, c'est Lena. Parce que cette image a des caractéristiques intéressantes : hautes et basses fréquence, aplats de couleur, etc.
Mais cette fameuse Lena... c'est un scan d'une photo de Playboy, donc pas très reluisant.
https://interestingengineering.com/culture/bye-lenna-iconic-playboy-pic-banned-from-research-papers

Ce photographe a donc proposé une re-création de Lena librement réutilisable et moins tendancieuse (du moment que vous indiquez la source).
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fahrbot-bot shares a report from Smithsonian Magazine: The brain is one of the first organs to begin decomposing after death. Yet archaeologists have discovered more than 4,400 preserved human brains around the world, some of which have remained intact for the last 12,000 years. In hundreds of cases, the brain was the only soft tissue left among otherwise skeletal remains. But how and why do brains sometimes persist for millennia while all other types of soft tissue disappear? This preservation paradox has stumped scientists for years. Now, however, a team of researchers say they may have solved the mystery. If a brain ends up in a wet, oxygen-starved environment, the processes that usually cause decay can have the opposite effect, researchers report in a study published in the August 7 issue of the Journal of Proteome Research. "Under the right conditions, preservation actually arises from decay itself: The same reactions that degrade tissue can also weld the breakdown products together into something far tougher," study co-author Alexandra Seviour, a paleobiologist at the University of Oxford in England, tells Live Science's Victoria Atkinson. Following experiments on 72 mouse carcasses (described in the article) the scientists think they know why. When oxygen is abundant, it triggers a cascading, chemical chain reaction that causes brain proteins to break down rapidly. This sequence hinges on free radicals, highly reactive, unstable molecules that "steal" electrons from nearby atoms and molecules. The process happens in the brains of living people too, and if left unchecked, can cause health problems. In low-oxygen environments, however, this chemical sequence appears to play out differently. The researchers' analyses hint that free radicals instead react and bond with nearby proteins, making the overall tissue tougher and more resistant to decomposition, Seviour tells Chemical and Engineering News' Anirban Mukhopadhyay. The findings show that "decay is not the opposite of preservation but, under specific chemical constraints, one of its mechanisms," the researchers write in the paper.

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An anonymous reader quotes a report from Ars Technica: Antibodies play a central role in your body's immune defense. But they're also nearly ubiquitous in biological research, being essential for several widely used lab techniques. While some researchers need to go through the process of producing their own antibodies, antibodies to many key proteins are commercially available and can be ordered for overnight delivery. In May, however, Reese Richardson, a post-doc at Northwestern University, discovered that some of the images used to demonstrate how these antibodies performed in lab experiments had been subject to image manipulation -- the sorts of changes that would get a paper retracted if they had appeared in the academic literature. The manipulations ranged from removing background noise to copying and pasting data to fabricate results. Now, he has done a more exhaustive search and found problematic manipulations in images used to market over 17,000 commercial antibodies. [...] The consequences of this discovery are pretty significant. If you buy an antibody believing it will generate clean, clear data and find it doesn't, many researchers will assume the problem is them. That often leads them to spend time troubleshooting the procedure and trying slightly different conditions to get useful data. If the antibody can't produce those results, all the troubleshooting will have been a waste of time and money. Nature's coverage of the new findings includes quotes from several companies that sell these antibodies that, paraphrased, range from "we'll look into it" to "we don't think it's a problem." Researchers who have spent time frustrated while failing to get an antibody-based experiment to work may think otherwise.

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Les prévisions annoncent qu’avec des températures des eaux du Pacifique excédant de 3 °C les températures habituelles d’après les estimations, le phénomène El Niño en cours devrait être exceptionnel. Se formant dans le Pacifique équatorial, El Niño peut avoir des répercussions climatiques, météorologiques et environnementales majeures à l’échelle planétaire. Explications.

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."

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