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New Study Links Teen Boys' ADHD Symptoms To Addictive Social Media Use

19 juillet 2026 à 07:34
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.

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Comment l’Europe a dompté l’antimatière

11 juillet 2026 à 17:18

De l’énigme cosmique du Big Bang aux expéditions d’antimatière en camion sur les routes de Genève, le CERN a transformé ce qui relevait de la science-fiction en une réalité d’ingénierie. Retour sur trois décennies de recherches, où les physiciens européens ont apprivoisé la substance la plus insaisissable de l’Univers !

Imaginez un instant que vous possédiez un double parfait. Un jumeau aux traits rigoureusement identiques, mais dont la simple poignée de main déclencherait une explosion, vous vaporisant instantanément tous les deux. À l’échelle des lois fondamentales de la physique, ce jumeau porte un nom : l’antimatière ! Née en 1928 dans les équations mathématiques du physicien Paul Dirac, l’antimatière est le reflet inversé de notre réalité. Chaque particule qui nous compose, et qui compose l’Univers, possède son « antiparticule », dotée de la même masse, mais d’une charge électrique opposée.

Si l’idée fascine les auteurs de science-fiction, elle pose surtout à la cosmologie moderne son énigme la plus vertigineuse. Selon les modèles standards, le Big Bang, cette fournaise primordiale, aurait dû forger des quantités parfaitement égales de matière et d’antimatière. Dès lors, le cosmos aurait dû s’autodétruire instantanément : toute la matière et l’antimatière s’annihilant mutuellement dans un « flash » de pure énergie. Et pourtant, regardez autour de vous : nous sommes bien là ! Les étoiles brillent, les planètes tournent…

Comme tout ce qui compose l’Univers, nous sommes donc les survivants d’une anomalie cosmique ! D’une manière ou d’une autre, une infime fraction de la matière (un atome sur 1 voire sur 10 milliards) a mystérieusement survécu à ce grand carnage des origines, ayant eu lieu il y a des milliards d’années. Si l’humanité veut comprendre un jour cette « asymétrie baryonique », il n’y a qu’une solution : il faut traquer l’antimatière, l’isoler et l’interroger.

Le problème ? L’antimatière terrestre n’existe pas à l’état naturel. Il faut la fabriquer de toutes pièces. Et c’est ici, à la frontière franco-suisse, que l’Organisation européenne pour la recherche nucléaire (le CERN) s’est imposée comme l’épicentre mondial d’une recherche de pointe, qui fait honneur à notre continent, capable de relever ce défi titanesque…

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What Is a Quantum Computer Good For? Absolutely Nothing - Yet

4 juillet 2026 à 14:34
The Verge argues that researchers "have made genuine progress in quantum computing — it's just been largely incremental and too esoteric to immediately capture the public's imagination." And there are predictions that quantum computers will finally do something useful as soon as 2028: The drama can overshadow the real progress in quantum computing... Researchers have improved the qubits themselves, so they hold onto information longer. When they hold onto information longer, you can fit in more operations and do more complicated algorithms. Last November, Andrew Houck of Princeton University and his colleagues reported that they'd made a superconducting qubit that can hold onto information three times longer than the previous record holder... And in the last two years, researchers have made substantial strides in what's known as quantum error correction... In addition, researchers have developed algorithms to correct errors while the quantum computer operates... Microsoft claimed, which experts dispute, that it made an object made of electrons known as a Majorana particle [which should make fewer errors and be easier to scale up]... "We 100 percent stand behind our results. We stand by our roadmap," Microsoft's quantum lead, Chetan Nayak, responded in an interview with The Verge. In an email statement, he added that Microsoft's "papers do show that we are creating and controlling Majorana [particles]... Microsoft's supporting evidence is unconvincing [according to [Henry Legg, a physicist from the University of St. Andrews and a longtime Microsoft critic]Rnqyq. What it claimed as evidence of a Majorana particle, he says, could actually be due to quantum dots forming in its device. Quantum dots are electron-containing objects that are not useful for Microsoft's quantum computer. It also bases its claim on data from a single device, says Legg. He wants to see Microsoft replicate the results in multiple chips. "If you repeatedly try and find Jesus in your toast, eventually you'll find Jesus in your toast," he says. "But that one piece of toast doesn't mean you had some kind of epiphany." "While we appreciate the religious fervor, our data maintains the strength and consistency of our roadmap, as we have for the past several years across previous milestones. We look forward to delivering the world's first quantum machine and sharing the energy of our achievements with the world," wrote Nayak in response. Past spurious work from Microsoft-affiliated researchers adds to the doubt. In 2021, the journal Nature retracted an article from Microsoft-affiliated researchers in which they'd claimed strong experimental evidence that they'd created a Majorana particle. "Even hopeful experts have varying opinions about when a quantum computer will demonstrate something useful," the article acknowledges. But quantum computing lecturer Eleanor Crane of King's College London predicts researchers will have demonstrated a useful scientific simulation on a quantum computer by 2028. Thanks to Slashdot reader joshuark for sharing the article.

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Claude Science is Here, Antibiotics Designed by Text Prompt Among Applications

Par : BeauHD
30 juin 2026 à 19:00
Anthropic has launched Claude Science, an AI workbench that connects more than 60 scientific databases and tools through a single interface. Through the platform, Basecamp Research is making its EDEN models available for tasks such as designing antibiotic peptides and predicting vaccine targets from simple text prompts, though the results still require laboratory testing before clinical use. Genetic Engineering and Biotechnology News reports: In a Claude Science demo, Oliver Vince, PhD, co-founder at Basecamp, uploaded a sample patient microbiology report. When given a simple natural language prompt, the platform designed peptides, predicted their efficacy, and provided a shortlist of candidates most likely to succeed in experiments in minutes. While generating human-ready antibiotics at the click of a button is still a step away, Vince said democratizing these tools is a powerful first step, particularly for researchers in regions where accelerated computing infrastructure is not readily accessible. "Most models require you to be a computational scientist," Vince told GEN Edge. "Now, potentially any clinician in the world can chat with Claude and design an antibiotic that may work."

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Max Planck Slapped With Two Paper Retractions By Suspected Rogue Algorithm

27 juin 2026 à 20:43
Max Planck won 1918's Nobel Prize for physics. Yet two of his papers were retracted — a move now being criticized by Yves Gingras, a historian of physics at the University of Quebec and Mahdi Khelfaoui, a fellow historian of science at UQ Trois-Rivières. Science reports: The papers, both quietly retracted in 2011, originally appeared in the early 1940s in Naturwissenschaften, a German journal now owned by publishing giant Springer Nature. After some sleuthing, Khelfaoui determined one of the Planck pieces, a philosophical essay from 1942 titled "Sinn und Grenzen der exakten Wissenschaft" ("Meaning and Limits of Exact Science"), about how to achieve certainty in scientific knowledge, had also appeared in two other journals and been reprinted twice in books. Repackaging the same work multiple times is considered "self-plagiarism" and frowned upon today — the practice produces copyright conflicts and inflates scholars' publication records. The Naturwissenschaften site gives "copyright violation" as the reason for the retraction. Yet publishing identical material in multiple journals was widespread before the internet. "Science was more fragmented" then, Khelfaoui says. "You wanted different audiences ... to have access to your work." The practice was especially common for luminaries like Planck. Albert Einstein did the same (but escaped retractions). Springer Nature's "anachronistic" application of modern standards to a 1942 paper "distort[s] the historical record," Gingras and Khelfaoui argue in a preprint posted last month on arXiv. Any concerns about copyright violations are largely moot anyway: Because Planck died in 1947, his works are in the public domain in most countries. Gingras was especially incensed that Springer Nature deviated from the normal practice of merely slapping the word RETRACTED across the digital version of the paper while still allowing scholars to read the text. Instead, the publisher posted a blank white page with the cryptic phrase, "This article has been withdrawn due to article violation." Springer Nature is nevertheless still selling the empty PDF for $39.95. Suzanne Scarlata, a chemist and biochemist at the Worcester Polytechnic Institute and editor-in-chief of The Science of Nature, as Naturwissenschaften is now known, had not heard about the retractions before being contacted for this story... Scarlata suspects Springer Nature's internal policing software removed the paper and posted the retraction notice unilaterally, without human supervision: "I think it just happened with their algorithm," she says. "It's a mistake they should probably rectify." A second Planck paper was apparently removed because its response to a 1940 paper had used an identical title. Thanks to our long-time Slashdot reader He Who Has No Name for sharing the article.

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Mushroom Behind 'Tiny Human' Visions Lacks Genes For Known Psychedelics

Par : BeauHD
24 juin 2026 à 11:00
alternative_right shares a report from ScienceAlert: If you consumed a wild mushroom and suddenly started seeing tiny people around you, you might reasonably assume it contained a familiar psychedelic. But that does not appear to be the case with Lanmaoa asiatica, known locally as jian shou qing, a mushroom species sold in markets in Yunnan, southwestern China. When eaten undercooked, the mushroom can produce vivid visions of miniature people -- not unlike Gulliver on his travels to Lilliput. To try and find out the root cause, University of Utah mycologists Colin Domnauer and Bryn Dentinger sequenced the genomes of 53 mushroom samples from across the wider Lanmaoa genus. And despite the reported hallucinations, they found no close matches to genes associated with psilocybin or ibotenic acid, two well-known mushroom hallucinogens whose biosynthetic pathways were specifically examined in the study. "Biosynthetic gene mining of the L. asiatica genome found no close hits with any genes known in the production of mushroom psychoactive compounds," write the researchers in their published paper. "This supports our hypothesis of the presence of a novel unidentified metabolite responsible for the unique hallucinogenic properties of L. asiatica." [...] Whatever chemical pathways are causing these effects in the brain, the responsible compound appears to be something scientists have not yet identified. [...] By identifying 1,515 corresponding genes across the selected specimens, the researchers obtained a clearer answer to the question of what defines a mushroom species as part of the genus Lanmaoa. There are now 17 recognized species in the genus, including four that haven't been identified before, two of which the researchers specifically named here: Lanmaoa fallax and Lanmaoa carbonilivor. The researchers say the Lanmaoa family and evolutionary tree can now be more fully mapped out, and some existing specimens may need to be reclassified.

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Humans Prefer To Walk Anticlockwise, Scientists Find

Par : BeauHD
11 juin 2026 à 07:00
fjo3 shares a report from The Guardian: Tests reveal that when people are ambling about, they have a natural tendency to turn to the left and walk in an anticlockwise direction. "If you simply ask someone to start walking, whether they are wandering around a museum, a supermarket, or even an empty room, it is surprisingly likely that they will drift counterclockwise," said Dr Inaki Echeverria Huarte at University of Navarra in Spain. As with many critical discoveries in science, the revelation owes a debt to serendipity. During the pandemic, the researchers ran experiments to see how many people could share a space while keeping a safe distance. On reviewing the video, they noticed that crowds overwhelmingly walked in an anticlockwise direction. The surprise set in motion an entire research project. The scientists conducted a series of experiments in which individual pedestrians or small crowds roamed around enclosed spaces. Time and again, the researchers observed the tendency to walk in an anticlockwise direction. Suspecting that cultural norms might play a role, the team joined forces with Dr Claudio Feliciani at the University of Tokyo. He found the same results in Japan. The finding held when the researchers accounted for people being right-handed, right-footed and right-eye dominant, and was seen in both male and female walkers. The only difference they spotted was a more pronounced bias in children. "Each of us carries a small personal bias to turn slightly to one side, and when many people share a space, those tiny biases add up into a net counterclockwise rotation," said Echeverria Huarte. Researchers think the tendency may be tied to biomechanics: people are not perfectly symmetrical, and the way the brain processes sensory information and coordinates muscles may gently tip walkers toward one side. Right-side dominance may also play a role, especially in running, where anticlockwise movement puts more internal force on the right side of the body and may feel more natural to right-leg-dominant athletes. "We have tested several ideas and the bias stubbornly keeps showing up, so the exact mechanism is still an open question," said Echeverria Huarte. The findings have been published in Nature Communications.

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After Empty Promises, Will String Theory Find New Uses?

7 juin 2026 à 15:34
Science magazine reports: For decades, string theory promised a "theory of everything" that described all particles and forces as tiny vibrating strings. Physicists hoped it could also solve one of the field's deepest problems: reconciling quantum mechanics with gravity. But as string theory grew increasingly elaborate — and experimentally unreachable — many physicists lost hope. Now, some researchers are revisiting the theory from first principles. In a paper in press at Physical Review Letters, Clifford Cheung, a physicist at the California Institute of Technology, and colleagues lay out a small set of assumptions about the universe and show that they inevitably give rise to string theory.... Cheung's study, along with another one posted to arXiv in January, starts with two reasonably conservative assumptions: that the probabilities of all possible outcomes of an event add up to 100%, and that the laws of physics are consistent for observers moving at different speeds. Each group then posits additional assumptions that have not been borne out by observations. Cheung's analysis invokes "ultrasoftness," the idea that the probability of certain particle interactions drops off at a particular rate at high energies. The second study, led by University of Michigan physicist Henriette Elvang, instead assumes "supersymmetry," a maximal coupling between matter and forces. Both groups conclude the only theory that can satisfy their assumptions is one that looks like string theory... Cheung and Elvang stress that their aim is not to prove the inevitability of string theory. "I don't have a dog in the fight; I just work here," Cheung says. Rather, the goal is to explore the space of possible theories under rigid constraints — regardless of whether they reflect reality... The one thing the researchers all agree on is that the field would benefit from more alternative models to string theory. Cheung sees the agnostic, bottom-up exploration as a step in that direction. "You can either give up on the problem because it's too culturally toxic, or you can ask: If you want to find an alternative, what do you need?" he says. "Now, we know exactly what to do." Thanks to Slashdot reader sciencehabit for sharing the article.

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New Desalination System Turns Seawater Into Drinking Water and Useful Salts - Including Lithium

1 juin 2026 à 03:54
"Scientists have developed a solar desalination system that turns seawater into drinking water without creating environmentally damaging brine," reports ScienceDaily. "Special laser-textured metal panels use sunlight to evaporate water while automatically moving salt deposits away from the working surface, preventing clogging. The process was successfully tested with water from three oceans and can recover nearly all salts as solids. Those leftover materials could even become a source of valuable lithium for batteries." (The research team was led by University of Rochest professor Chunlei Guo and published their results in the journal Light: Science & Applications.) The University of Rochester has made an announcement: The technology uses solar panels made of black metal etched with femtosecond lasers to make the surface super light-absorbing and superwicking — or extremely attractive to water. The panels have a laser-treated active region that pulls a thin layer of water across the surface, absorbs nearly all solar radiation, distills the water, and deposits the leftover salts and minerals into the panel's untreated sides or "passive" region so that the salt does not clog the active region and disrupt continuous desalination... Guo's team precisely etched the black metal's grooves so the various salts and minerals in ocean water would simply slough off... [I]t extracts nearly 100 percent of the salts in solid form. This could not only produce an abundant supply of table salt, but it could also be used to extract more precious minerals, including lithium, which is used in the lithium-ion batteries that power electric vehicles and other electronics. In a related paper in the Journal of Materials Chemistry A, Guo and his colleagues show how they can use the same superwicking solar panels to separate lithium from the rest of other salts in desalination. Embedding nanoparticles made of hydrogen titanate in the tiny grooves of the black metal surface isolates the lithium from other salts and minerals...Using water samples from Great Salt Lake, the researchers extracted about 50 percent of the lithium from the salts left behind by the desalination process. Guo says now that the superwicking desalination technology has been demonstrated in proofs of concept on small-scale devices, he sees the technology inherently scalable, capable of improving global access to drinking water and building more sustainable supply chains for precious minerals. "The National Science Foundation, the Bill & Melinda Gates Foundation, and Worldwide Universities Network supported this research."

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