An anonymous reader quotes a report from the Guardian: High-profile studies reporting the presence of microplastics throughout the human body have been thrown into doubt by scientists who say the discoveries are probably the result of contamination and false positives. One chemist called the concerns "a bombshell." Studies claiming to have revealed micro and nanoplastics in the brain, testes, placentas, arteries and elsewhere were reported by media across the world, including the Guardian. There is no doubt that plastic pollution of the natural world is ubiquitous, and present in the food and drink we consume and the air we breathe. But the health damage potentially caused by microplastics and the chemicals they contain is unclear, and an explosion of research has taken off in this area in recent years. However, micro- and nanoplastic particles are tiny and at the limit of today's analytical techniques, especially in human tissue. There is no suggestion of malpractice, but researchers told the Guardian of their concern that the race to publish results, in some cases by groups with limited analytical expertise, has led to rushed results and routine scientific checks sometimes being overlooked. The Guardian has identified seven studies that have been challenged by researchers publishing criticism in the respective journals, while a recent analysis listed 18 studies that it said had not considered that some human tissue can produce measurements easily confused with the signal given by common plastics. There is an increasing international focus on the need to control plastic pollution but faulty evidence on the level of microplastics in humans could lead to misguided regulations and policies, which is dangerous, researchers say. It could also help lobbyists for the plastics industry to dismiss real concerns by claiming they are unfounded. While researchers say analytical techniques are improving rapidly, the doubts over recent high-profile studies also raise the questions of what is really known today and how concerned people should be about microplastics in their bodies.

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A major new review by the Cochrane collaboration -- an independent network of researchers -- evaluated 73 randomized controlled trials involving about 5,000 people with depression and found that exercise matched the effectiveness of both pharmacological treatments and psychological therapies. The biological mechanisms overlap considerably with antidepressants. "Exercise can help improve neurotransmitter function, like serotonin as well as dopamine and endorphins," said Dr. Stephen Mateka, medical director of psychiatry at Inspira Health. Dr. Nicholas Fabiano of the University of Ottawa added that exercise triggers the release of brain-derived neurotrophic factor, or BDNF, which he calls "Miracle-Gro for the brain." Exercise has been adopted as a first-line treatment in depression guidelines globally, though Fabiano noted it remains underutilized. The meta-analysis found that combining aerobic exercise and resistance training appeared more effective than aerobic exercise alone, and that 13 to 36 workouts led to improvements in depressive symptoms. Light to moderate exercise proved as beneficial as vigorous workouts, at least initially.

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An R&D lab under America's Energy Department annnounced this week that "Neuromorphic computers, inspired by the architecture of the human brain, are proving surprisingly adept at solving complex mathematical problems that underpin scientific and engineering challenges." Phys.org publishes the announcement from Sandia National Lab: In a paper published in Nature Machine Intelligence, Sandia National Laboratories computational neuroscientists Brad Theilman and Brad Aimone describe a novel algorithm that enables neuromorphic hardware to tackle partial differential equations, or PDEs — the mathematical foundation for modeling phenomena such as fluid dynamics, electromagnetic fields and structural mechanics. The findings show that neuromorphic computing can not only handle these equations, but do so with remarkable efficiency. The work could pave the way for the world's first neuromorphic supercomputer, potentially revolutionizing energy-efficient computing for national security applications and beyond... "We're just starting to have computational systems that can exhibit intelligent-like behavior. But they look nothing like the brain, and the amount of resources that they require is ridiculous, frankly," Theilman said.For decades, experts have believed that neuromorphic computers were best suited for tasks like recognizing patterns or accelerating artificial neural networks. These systems weren't expected to excel at solving rigorous mathematical problems like PDEs, which are typically tackled by traditional supercomputers. But for Aimone and Theilman, the results weren't surprising. The researchers believe the brain itself performs complex computations constantly, even if we don't consciously realize it. "Pick any sort of motor control task — like hitting a tennis ball or swinging a bat at a baseball," Aimone said. "These are very sophisticated computations. They are exascale-level problems that our brains are capable of doing very cheaply..." Their research also raises intriguing questions about the nature of intelligence and computation. The algorithm developed by Theilman and Aimone retains strong similarities to the structure and dynamics of cortical networks in the brain. "We based our circuit on a relatively well-known model in the computational neuroscience world," Theilman said. "We've shown the model has a natural but non-obvious link to PDEs, and that link hasn't been made until now — 12 years after the model was introduced." The researchers believe that neuromorphic computing could help bridge the gap between neuroscience and applied mathematics, offering new insights into how the brain processes information. "Diseases of the brain could be diseases of computation," Aimone said. "But we don't have a solid grasp on how the brain performs computations yet." If their hunch is correct, neuromorphic computing could offer clues to better understand and treat neurological conditions like Alzheimer's and Parkinson's.

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Scientists are putting Einstein's claim that the speed of light is constant to the test. While researchers found no evidence that light's speed changes with energy, this null result dramatically tightens the constraints on quantum-gravity theories that predict even the tiniest violations. ScienceDaily reports: Special relativity rests on the principle that the laws of physics remain the same for all observers, regardless of how they are moving relative to one another. This idea is known as Lorentz invariance. Over time, Lorentz invariance became a foundational assumption in modern physics, especially within quantum theory. [...] One prediction shared by several Lorentz-invariance-violating quantum gravity models is that the speed of light may depend slightly on a photon's energy. Any such effect would have to be tiny to match existing experimental limits. However, it could become detectable at the highest photon energies, specifically in very-high-energy gamma rays. A research team led by former UAB student Merce Guerrero and current IEEC PhD student at the UAB Anna Campoy-Ordaz set out to test this idea using astrophysical observations. The team also included Robertus Potting from the University of Algarve and Markus Gaug, a lecturer in the Department of Physics at the UAB who is also affiliated with the IEEC. Their approach relies on the vast distances light travels across the universe. If photons of different energies are emitted at the same time from a distant source, even minuscule differences in their speeds could build up into measurable delays by the time they reach Earth. Using a new statistical technique, the researchers combined existing measurements of very-high-energy gamma rays to examine several Lorentz-invariance-violating parameters favored by theorists within the Standard Model Extension (SME). The goal was ambitious. They hoped to find evidence that Einstein's assumptions might break down under extreme conditions. Once again, Einstein's predictions held firm. The study did not detect any violation of Lorentz invariance. Even so, the results are significant. The new analysis improves previous limits by an order of magnitude, sharply narrowing where new physics could be hiding.

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alternative_right shares a report from ScienceAlert: At the Experimental Advanced Superconducting Tokamak (EAST), physicists successfully exceeded what is known as the Greenwald limit, a practical density boundary beyond which plasmas tend to violently destabilize, often damaging reactor components. For a long time, the Greenwald limit was accepted as a given and incorporated into fusion reactor engineering. The new work shows that precise control over how the plasma is created and interacts with the reactor walls can push it beyond this limit into what physicists call a 'density-free' regime. [...] A team led by physicists Ping Zhu of Huazhong University of Science and Technology and Ning Yan of the Chinese Academy of Sciences designed an experiment to take this theory further, based on a simple premise: that the density limit is strongly influenced by the initial plasma-wall interactions as the reactor starts up. In their experiment, the researchers wanted to see if they could deliberately steer the outcome of this interaction. They carefully controlled the pressure of the fuel gas during tokamak startup and added a burst of heating called electron cyclotron resonance heating. These changes altered how the plasma interacts with the tokamak walls through a cooler plasma boundary, which dramatically reduced the degree to which wall impurities entered the plasma. Under this regime, the researchers were able to reach densities up to about 65 percent higher than the tokamak's Greenwald limit. This doesn't mean that magnetically confined plasmas can now operate with no density limits whatsoever. However, it does show that the Greenwald limit is not a fundamental barrier and that tweaking operational processes could lead to more effective fusion reactors. The findings have been published in Science Advances.

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Researchers at Stanford University have created a programmable synthetic "skin" that can independently change color and texture, "a feat previously only available within the animal kingdom," reports the Register. From the report: The technique employs electron beams to write patterns and add optical layers that create color effects. When exposed to water, the film swells to reveal texture and colors independently, depending on which side of the material is exposed, according to a paper published in the scientific journal Nature this week. In an accompanying article, University of Stuttgart's Benjamin Renz and Na Liu said the researchers' "most striking achievement was a photonic skin in which color and texture could be independently controlled, mirroring the separate regulation... in octopuses." The research team used the polymer PEDOT:PSS, which can swell in water, as the basis for their material. Its reaction to water can be controlled by irradiating it with electrons, creating textures and patterns in the film. By adding thin layers of gold, the researchers turned surface texture into tunable optical effects. A single layer could be used to scatter light, giving the shiny metal a matte, textured appearance. To control color, a polymer film was sandwiched between two layers of gold, forming an optical cavity, which selectively reflects light.

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An anonymous reader quotes a report from NPR: [I]t turns out that some genius dogs can learn a brand new word, like the name of an unfamiliar toy, by just overhearing brief interactions between two people. What's more, these "gifted" dogs can learn the name of a new toy even if they first hear this word when the toy is out of sight -- as long as their favorite human is looking at the spot where the toy is hidden. That's according to a new study in the journal Science. "What we found in this study is that the dogs are using social communication. They're using these social cues to understand what the owners are talking about," says cognitive scientist Shany Dror of Eotvos Lorand University and the University of Veterinary Medicine, Vienna. "This tells us that the ability to use social information is actually something that humans probably had before they had language," she says, "and language was kind of hitchhiking on these social abilities." [...] "There's only a very small group of dogs that are able to learn this differentiation and then can learn that certain labels refer to specific objects," she says. "It's quite hard to train this and some dogs seem to just be able to do it." [...] To explore the various ways that these dogs are capable of learning new words, Dror and some colleagues conducted a study that involved two people interacting while their dog sat nearby and watched. One person would show the other a brand new toy and talk about it, with the toy's name embedded into sentences, such as "This is your armadillo. It has armadillo ears, little armadillo feet. It has a tail, like an armadillo tail." Even though none of this language was directed at the dogs, it turns out the super-learners registered the new toy's name and were later able to pick it out of a pile, at the owner's request. To do this, the dogs had to go into a separate room where the pile was located, so the humans couldn't give them any hints. Dror says that as she watched the dogs on camera from the other room, she was "honestly surprised" because they seemed to have so much confidence. "Sometimes they just immediately went to the new toy, knowing what they're supposed to do," she says. "Their performance was really, really high." She and her colleagues wondered if what mattered was the dog being able to see the toy while its name was said aloud, even if the words weren't explicitly directed at the dog. So they did another experiment that created a delay between the dog seeing a new toy and hearing its name. The dogs got to see the unfamiliar toy and then the owner dropped the toy in a bucket, so it was out of sight. Then the owner would talk to the dog, and mention the toy's name, while glancing down at the bucket. While this was more difficult for dogs, overall they still could use this information to learn the name of the toy and later retrieve it when asked. "This shows us how flexible they are able to learn," says Dror. "They can use different mechanisms and learn under different conditions."

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Every human body contains a small population of cells that are not genetically its own -- cells that crossed the placenta during pregnancy and that persist for decades after birth. These "microchimeric" cells, named after the lion-goat-serpent hybrid of Greek mythology, have been found in every organ studied so far, though they are exceedingly rare: one such cell exists for every 10,000 to 1 million of a person's own cells. The cells were first noticed in the late 1800s when pathologist Georg Schmorl described placenta-like "giant cells" in the lungs of people who had died from eclampsia. In 1969, researchers detected Y-chromosome-containing white blood cells in people who would later give birth to boys. For more than two decades, scientists presumed these cells were temporary. That changed in 1993 when geneticist Diana Bianchi found Y-chromosome cells in women who had given birth to sons up to 27 years earlier. The cells appear to have regenerative properties, transforming into blood vessels or skin cells to promote wound healing. They also challenge a central assumption of immunology -- that the immune system classifies cells as either "self" or "non-self" and rejects foreign material. Microchimeric cells should trigger rejection but do not. Higher-than-typical concentrations have been found in people with autoimmune conditions including diabetes, lupus, and scleroderma.

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Mark Thomson, a professor of experimental particle physics at the University of Cambridge, takes over as CERN's director general this week, and one of his first major decisions during his five-year tenure will be shutting down the Large Hadron Collider for an extended upgrade. The shutdown starts in June to make way for the high-luminosity LHC -- a major overhaul involving powerful new superconducting magnets that will squeeze the collider's proton beams and increase their brightness. The upgrade will raise collisions tenfold and strengthen the detectors to better capture subtle signs of new physics. The machine won't restart until Thomson's term is nearly over. Thomson is far from disconsolate about the downtime. "The machine is running brilliantly and we're recording huge amounts of data," he told The Guardian. "There's going to be plenty to analyse over the period." Beyond the upgrade, Thomson must shepherd CERN's plans for the Future Circular Collider, a proposed 91km machine more than three times the size of the current collider. Member states vote on the project in 2028; the first phase carries an estimated price tag of 15 billion Swiss francs (nearly $19 billion).

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A large-scale study tracking more than 27,500 middle-aged and elderly people over roughly nine years has found that poor sleep quality is associated with accelerated brain aging, and chronic inflammation appears to be one of the key mechanisms driving this effect. Researchers at Sweden's Karolinska Institute assessed participants' sleep across five dimensions -- chronotype, duration, insomnia, snoring and daytime sleepiness -- and later scanned their brains using MRI to estimate biological brain age through machine learning models. The results? For every point decrease in healthy sleep score, the gap between brain age and chronological age widened by approximately six months. Those in the poorest sleep category had brains that appeared roughly one year older than their actual age. Night-owl tendencies, sleep duration outside the 7-8 hour sweet spot and snoring were particularly strongly linked to brain aging. The researchers measured low-grade inflammation using biomarkers including C-reactive protein levels and white blood cell counts. Inflammation accounted for more than 10% of the association between poor sleep patterns and brain aging. The glymphatic system, which clears waste from the brain primarily during sleep, may also play a role, the research added.

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Colossal Biosciences, the Texas-based startup now valued at more than $10 billion that has attracted investments from Paris Hilton, Peter Jackson and Tom Brady, claimed earlier this year to have resurrected the dire wolf -- an animal that disappeared at the end of the last ice age -- but a group of leading canid experts concluded the company had done no such thing. The scientists found that Colossal had made 20 edits to the DNA of grey wolves and the resulting animals did not substantially differ from wolves currently roaming North America. Beth Shapiro, Colossal's own chief scientist, acknowledged to New Scientist: "It's not possible to bring something back that is identical to a species that used to be alive. Our animals are grey wolves with 20 edits that are cloned." Nic Rawlence, director of the palaeogenetics laboratory at the University of Otago in New Zealand, added: "Rather than true de-extinction, Colossal's attempts are genetically engineered poor copies at best, passed off as the real deal." The company has nevertheless pressed forward. It has launched projects to revive the Tasmanian tiger, the dodo, and the moa and plans to unveil its interpretation of the woolly mammoth -- a genetically modified Asian elephant adapted to survive at -40C -- in the coming years. The Trump administration cited the dire wolf announcement while making efforts to cut the US endangered species list, calling de-extinction technology a potential "bedrock for modern species conservation."

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The World Health Organization's latest annual malaria report paints a grim picture that's about to get grimmer, as the United States -- which has supplied 37% of global malaria funding since 2010 -- pulls back its international health commitments under President Donald Trump. Malaria cases have been climbing since 2015, when progress against the mosquito-borne disease stalled due to insecticide resistance and chronic underfunding. In 2024, the world recorded 282 million cases and 610,000 deaths, and African countries accounted for 95% of both figures. Children under 5 made up 75% of malaria-related deaths in Africa. Global spending on malaria reached $3.9 billion last year. Trump's decision to slash international public health funding and gut the US Agency for International Development has caused what the WHO calls "widespread disruption to health operations around the world." The burden of these setbacks, the organization adds, is expected to fall disproportionately on children. Seventeen countries now offer malaria vaccines to younger populations, up from three countries the year before, but funding constraints mean many countries still can't provide the shots.

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An astrophysicist at the University of Rochester writes that "many" of his colleagues in physics "have come to believe that a mystery is unfolding in every microbe, animal, and human." And it's a mystery that: - "Challenges basic assumptions physicists have held for centuries" - "May even help redefine the field for the next generation" - "Could answer essential questions about AI." In short, while physicists have favored a "reductionist" philosophy about the fundamental laws controlling the universe (energy, mattery, space, and time), "long-promised 'theories of everything' such as string theory, have not borne significant fruit: There are, however, ways other than reductionism to think about what's fundamental in the universe. Beginning in the 1980s, physicists (along with researchers in other fields) began developing new mathematical tools to study what's called "complexity" — systems in which the whole is far more than the sum of its parts. The end goal of reductionism was to explain everything in the universe as the result of particles and their interactions. Complexity, by contrast, recognizes that once lots of particles come together to produce macroscopic things — such as organisms — knowing everything about particles isn't enough to understand reality... Physicists have always been good at capturing the essential aspects of a system and casting those essentials in the language of mathematics... Now those skills must be brought to bear on an age-old question that is only just getting its proper due: What is life? Using these skills, physicists — working together with representatives of all the other disciplines that make up complexity science — may crack open the question of how life formed on Earth billions of years ago and how it might have formed on the distant alien worlds we can now explore with cutting-edge telescopes. Just as important, understanding why life, as an organized system, is different at a fundamental level from all the other stuff in the universe may help astronomers design new strategies for finding it in places bearing little resemblance to Earth. Analyzing life — no matter how alien — as a self-organizing information-driven system may provide the key to detecting biosignatures on planets hundreds of light-years away. Closer to home, studying the nature of life is likely essential to fully understanding intelligence — and building artificial versions. Throughout the current AI boom, researchers and philosophers have debated whether and when large language models might achieve general intelligence or even become conscious — or whether, in fact, some already have. The only way to properly assess such claims is to study, by any means possible, the sole agreed-upon source of general intelligence: life. Bringing the new physics of life to problems of AI may not only help researchers predict what software engineers can build; it may also reveal the limits of trying to capture life's essential character in silicon.

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Tony Isaac shares a report from NPR: The U.S. government calculates the country's official time using more than a dozen atomic clocks at a federal facility northwest of Denver. But when a destructive windstorm knocked out power to the National Institute of Standards and Technology (NIST) laboratory in Boulder on Wednesday and a backup generator subsequently failed, time ever so slightly slowed down. The lapse "resulted in NIST UTC [universal coordinated time] being 4.8 microseconds slower than it should have been," NIST spokesperson Rebecca Jacobson said in an email. [...] Since 2007, the official time of the U.S. has been determined by the commerce secretary, who oversees NIST, along with the U.S. Navy. The national time standard is known as NIST UTC. (Somewhat confusingly, UTC itself is a separate, global time standard to which the U.S. and other countries contribute measurements.) NIST currently calculates the standard using a weighted average of the readings of 16 atomic clocks situated across the Boulder campus. Atomic clocks, including hydrogen masers and cesium beam clocks, rely on the natural resonant frequencies of atoms to tell time with extremely high accuracy. All of the atomic clocks continued ticking through the power outage last week thanks to their battery backup systems, according to NIST supervisory research physicist Jeff Sherman. What failed was the connection between some of the clocks and NIST's measurement and distribution systems, he said. Some critical operations staff who were still on site following the severe weather were able to restore backup power by activating a diesel generator the team had kept in reserve, Sherman said.

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L’article Dernières nouvelles de l’au-delà est apparu en premier sur Les Électrons Libres.

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More carbon dioxide in the environment is making food more calorific but less nutritious -- and also potentially more toxic, a study has found. From a report: Sterre ter Haar, a lecturer at Leiden University in the Netherlands, and other researchers at the institution created a method to compare multiple studies on plants' responses to increased CO2 levels. The results, she said, were a shock: although crop yields increase, they become less nutrient-dense. While zinc levels in particular drop, lead levels increase. "Seeing how dramatic some of the nutritional changes were, and how this differed across plants, was a big surprise," she told the Guardian. "We aren't seeing a simple dilution effect but rather a complete shift in the composition of our foods... This also raises the question of whether we should adjust our diets in some way, or how we grow or produce our food." While scientists have been looking at the effects of more CO2 in the atmosphere on plants for a decade, their work has been difficult to compare. The new research established a baseline measurement derived from the observation that the gas appears to have a linear effect on growth, meaning that if the CO2 level doubles, so does the effect on nutrients. This made it possible to compare almost 60,000 measurements across 32 nutrients and 43 crops, including rice, potatoes, tomatoes and wheat.

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alternative_right shares a report from ScienceAlert: A new study adds to the growing body of evidence that swearing can help us unleash our inner strength, improving physical performance, it seems, by helping people break through certain psychological barriers. [...] [Psychology researcher Richard Stephens of Keele University in the UK] and his colleagues at Keele and the University of Alabama wanted to test whether swearing could not only improve physical performance, as they had done in previous research, but also see whether it does so by changing a person's psychology in the moment, especially when it comes to letting go of inhibitions. Eighty-eight participants, aged 18 to 65, all in good enough shape to exert themselves physically, were recruited at a university campus to participate in the first experiment. They each selected a pair of words based on the following prompts: a swear word you might utter after bumping your head, and a neutral word you might use to describe a table. Then, they undertook a chair push-up, which involves sitting in a chair and, holding each side of the seat, using your arms to lift your entire body weight (bottom off the chair, feet off the floor). [...] Both experiments suggested that swearing offers an advantage in physical performance, with participants achieving longer chair push-up hold times as they repeated their foul-mouthed mantras. Scores for positive emotion, humor, distraction, and novelty were also elevated in the swearing tests, which suggests invoking their favorite four-letter word might enable people to transition into more action-oriented states, and perhaps actually enjoy their workout more. The research is published in American Psychologist.

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A comprehensive database built by scientists in Switzerland and Norway has catalogued 16,000 chemicals linked to plastic materials, and the findings paint a troubling picture of what Americans are actually eating when they prepare food in their kitchens. Of those 16,000 chemicals, more than 5,400 are considered hazardous to human health by government and industry standards, while just 161 are classified as not hazardous. The remaining 10,700-plus chemicals simply don't have enough data to determine their safety. The chemicals enter food through multiple pathways. Black plastic utensils and trays often contain brominated flame retardants because they're made from recycled electronic waste. Nonstick pans and compostable plates frequently contain PFAS. One California study found phthalates in three-quarters of tested foods, and a Consumer Reports analysis last year detected BPA or similar chemicals in 79% of foods tested. According to CDC data, more than 90% of Americans have measurable levels of these chemicals in their bodies. A 10-fold increase in maternal levels of brominated flame retardants is associated with a 3.7-point IQ drop in children.

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For decades, Parkinson's disease research has overwhelmingly focused on genetics -- more than half of all research dollars in the past two decades flowed toward genomic studies -- but a growing body of evidence now points to something far more mundane as a primary culprit: contaminated drinking water. A landmark study by epidemiologist Sam Goldman compared Marines stationed at Camp Lejeune in North Carolina, where trichloroethylene (TCE) had contaminated the water supply for approximately 35 years, against those at Camp Pendleton in California, which has clean water. Marines exposed to TCE at Lejeune were 70% more likely to develop Parkinson's. The latest research suggests only 10 to 15 percent of Parkinson's cases can be fully explained by genetics. Parkinson's rates in the US have doubled in the past 30 years -- a pattern inconsistent with an inherited genetic disease. The EPA moved to ban TCE in December 2024. The Trump administration moved to undo the ban in January.

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« L'un des avantages de cette technologie est sa flexibilité. Plutôt que de dépendre d'antigènes spécifiques pour chaque cancer, qui nécessitent des analyses génomiques approfondies, les chercheurs ont testé une version utilisant des lysats tumoraux. Cette approche a donné des taux de rejet élevés: 88 % pour le cancer du pancréas, 75 % pour le cancer du sein et 69 % pour le mélanome. »
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