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"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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fjo3 shares a report from Phys.org: Ever felt like mosquitoes bite you while ignoring everyone else? Scientists are now making progress in deciphering the complex chemical cocktail that makes particular people more enticing to these disease-spreading bloodsuckers. "It's not a misconception -- mosquitoes are attracted to some people more than others," Frederic Simard of France's Institute of Research for Development told AFP. "But we are not all magnets all the time," the medical entomologist added. A range of sensory cues can cause mosquitoes to pick one human over another -- mainly the smell and heat our bodies give off, and the carbon dioxide we exhale. Female mosquitoes -- which are the only ones that bite -- detect these signals with finely tuned receptors, then choose their target accordingly. "We have known for over 100 years that mosquitoes are attracted by the carbon dioxide that we exhale -- this is the first signal that triggers their behavior" when they are dozens of meters away, Swedish scientist Rickard Ignell told AFP. Within around 10 meters, "mosquitoes will start detecting our odor, and in combination with carbon dioxide," this attracts them even more, said the senior author of a recent study on the subject. As they get closer, body temperature and humidity make particular humans even more enticing. [...] For Ignell's recent study, the researchers released Aedes aegypti mosquitoes -- known for spreading yellow fever and dengue -- on 42 women in a lab, to see which ones they preferred. "We have shown that mosquitoes use a blend of odorous compounds (we identified 27 that the mosquitoes will detect, out of the possible 1,000) for their attraction to us," Ignell said. The woman the mosquitoes most liked to bite -- which included pregnant women in their second trimester -- produced a large amount of a particular compound made by a breakdown of the skin oil sebum. That even a small increase of this compound -- called "1-octen-3-ol", or mushroom alcohol -- made a difference came as a surprise, Ignell emphasized.

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"Plant seeds can sense the vibrations generated by falling raindrops," reports ScienceAlert, "and respond by waking from their state of dormancy to welcome the water, new research shows.... to germinate in 'anticipation' of the coming deluge." The finding, discovered by MIT mechanical engineers Nicholas Makris and Cadine Navarro, offers the first direct evidence that seeds and seedlings can sense and respond to sounds in nature... "The energy of the rain sound is enough to accelerate a seed's growth," [explains Markis]. Plants don't have the same aural equipment we do to actually hear sounds, of course. But the study suggests that seeds respond to the same vibrations that can produce a sound experience in our human ears. Across a series of experiments, the researchers submerged nearly 8,000 rice seeds in shallow tubs of water, at a depth of around 3 centimeters (1 inch), and exposed some of them to falling water drops over periods of six days... A hydrophone recorded the acoustic vibrations produced by the drops, confirming that the experiment mimicked the vibrations produced by actual raindrops falling in nature — such as the driving downpours that can sometimes pelt Massachusetts' puddles, ponds, and wetlands... In their study, the researchers observed that seeds exposed to the falling drops germinated up to around 37% faster, compared with seeds that did not receive the simulated rainstorm treatment but were housed in otherwise identical conditions. More information in Scientific American and Scientific Reports.

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An anonymous reader quotes a report from Ars Technica: In a makeshift demonstration kitchen in Concord, California, cooking oil splatters in and around a frying pan, which catches fire on an unattended gas stove. Within moments, a smoke detector wails. But in this demonstration, something less common happens: An AI-driven sensor activates and wall emitters blast infrasound waves toward the source of the fire in an attempt to put it out. The science of acoustic fire suppression, which has long been known and documented in scientific literature and the press, works by vibrating oxygen molecules away from a fuel source, depriving the fire of a critical component needed for combustion. Indeed, after just a few seconds of infrasound, the tiny kitchen blaze goes out. "We were able to not just point-and-shoot like a fire extinguisher; we figured out how to run it through ducting and distribute it like a sprinkler system," said Geoff Bruder, co-founder and CEO of Sonic Fire Tech, during the presentation. The company's goal is to replace sprinklers, which are effective at stopping fires but can also do significant water damage to a property. Sonic Fire Tech appears to be the first company trying to commercialize the science of acoustic fire suppression. Its executives have already been touring Southern California; Wednesday's event was the first in the northern half of the state. The company aims to make this infrasound technique mainstream in both commercial (for instance, a data center, where sprinklers would damage electronics) and in-home installations, given that sprinklers are already required in all new California homes built in 2011 and later. Sonic Fire Tech also hopes to produce a backpack-based system that could be worn by wildland firefighters headed out into the field. "We are making meaningful technological improvements on a monthly basis," Stefan Pollack, a company spokesperson, emailed Ars after the event. But two experts who spoke with Ars raised serious questions about the potential for this technology to supplant traditional sprinklers in a home. They are even more skeptical as to whether the technique can be effective in an uncontrolled wildfire situation, where flames can grow very quickly. Experts are concerned that infrasound may knock down small flames but does not cool hot surfaces or wet fuel like sprinklers do, which raises the risk of re-ignition, smoldering fires, hidden fires, or blocked fires. Sonic Fire Tech has claimed third-party validation and possible NFPA 13D equivalency, but it has not publicly released full testing details. Fire officials and outside observers also want more information about reliability, maintenance, calibration, and how system failures would be detected and communicated.

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A new meta-analysis found nutrients in food decreased over the last 40 years, reports the Washington Post. "Many of humanity's most important crops — including wheat, potatoes, beans — contain fewer vitamins and minerals than they did a generation ago." "The invisible culprit behind this damaging phenomenon? Carbon dioxide pollution." Surging concentrations of carbon in the atmosphere, caused largely by burning fossil fuels, have produced potent changes in the way plants grow — from increasing their sugar content to depleting essential nutrients like zinc... "The diets we eat today have less nutritional density than what our grandparents ate, even if we eat exactly the same thing," said Kristie Ebi, a professor at the University of Washington's Center for Health and the Global Environment. People in wealthy countries with strong health care systems will have many tools to cope with the change, experts said. But for the world's poorest and most vulnerable, the consequences could be devastating. One study concluded that by the middle of the century the phenomenon could put more than a billion additional women and children at risk of iron-deficiency anemia — a condition that can cause pregnancy complications, developmental problems and even death. Meanwhile, some 2 billion people across the globe who already suffer from some form of nutrient shortage could see their health problems grow even worse. "The scale of the problem is huge," Ebi said. Plants depend on carbon dioxide to perform photosynthesis — but that doesn't mean they grow better when there's more carbon in the air, scientists say. A sweeping survey of changes among 32 compounds in 43 crops found that nearly every plant that humans eat is harmed by rising CO2 levels... On average, they found, nutrients have already decreased by an average 3.2 percent across all plants since the late 1980s, when the concentration of carbon dioxide in the atmosphere was about 350 parts per million. Thanks to long-time Slashdot reader GameboyRMH for sharing the news.

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"Scientists have created a miraculous new way to stop fires from spreading through neighborhoods using nothing but sound," reports the New York Post: Former NASA engineers with California-based Sonic Fire Tech found that using sound waves can snuff out blazes and potentially be used to stop another Pacific Palisades inferno... The technology works by targeting oxygen molecules using low-frequency sound waves that vibrate them, stopping the fire from growing. "Sound waves vibrate the oxygen faster than the fuel can use it, and break the chemical reaction of the flame," Remington Hotchkis, Chief Commercialization Officer at Sonic Fire Tech told The Post. The San Bernardino County Fire Department recently tested out the equipment using a backpack version and the results were incredible. Video shows firefighters fighting small blazes on a shrub and a stove top fire with the technology putting it out... In the home application, the system would be alerted/activated if there was a fire, sending the sound waves through a home duct system, essentially snuffing out the blaze. The sound waves can reach as far as 30ft from a home, the report noted. The sound is also harmless to pets and humans. The article includes this quote that an executive at the company gave local news station KMPH. "Our former NASA engineers are rocket scientists, and they say it seems like magic, but it's just physics."

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Researchers say infrasound -- low-frequency vibrations from things like pipes, HVAC systems, and traffic that humans can't consciously hear -- may help explain why some old buildings feel unsettling or "haunted." Rodney Schmaltz, senior author and professor at MacEwan, says: "Consider visiting a supposedly haunted building. Your mood shifts, you feel agitated, but you can't see or hear anything unusual. In an old building, there is a good chance that infrasound is present, particularly in basements where aging pipes and ventilation systems produce low-frequency vibrations. If you were told the building was haunted, you might attribute that agitation to something supernatural. In reality, you may simply have been exposed to infrasound." ScienceBlog.com reports: Infrasound sits below roughly 20 Hz, the lower limit of what the human ear can ordinarily detect. It's generated by storms, by volcanic activity, by tectonic rumblings deep in the Earth's crust, and (this is the part that matters) by the mundane mechanical heartbeat of cities: ageing pipes, HVAC systems, traffic, industrial machinery. "Infrasound is pervasive in everyday environments, appearing near ventilation systems, traffic, and industrial machinery," says Schmaltz. Most of the time, we walk through it without a second thought. The question the team wanted to answer was whether walking through it was actually doing something to us, whether the frequency was registered somewhere below consciousness, somewhere we couldn't readily name. The experimental setup was deliberately ordinary. Thirty-six undergraduate students filed one at a time into isolated testing rooms and sat alone with a piece of music, either a calming instrumental or a horror-themed ambient track designed to provoke discomfort. Hidden subwoofers, including a 12-inch unit positioned in an adjacent hallway and a 16-inch speaker oriented toward the ceiling in a neighboring room, pumped infrasound at approximately 18 Hz into half those spaces. The participants had no idea. That last point turned out to be rather important. When the team ran the numbers, they found that participants couldn't reliably identify whether infrasound had been present. Their guesses were, statistically speaking, no better than chance. And according to Schmaltz, participants' beliefs about whether the infrasound was on had no detectable effect on their cortisol or mood. The physiological response didn't care what the participants thought was happening. It just happened anyway. What happened, specifically, was this: those exposed to infrasound reported higher irritability, lower interest in the music, and a tendency to rate the music as sadder, irrespective of whether it was the calming or the horror track. Cortisol levels, measured before and about 20 minutes after exposure, were also elevated. Kale Scatterty, the PhD student who led the work, notes that irritability and cortisol do tend to move together under ordinary stress, but adds that "infrasound exposure had effects on both outcomes that went beyond that natural relationship." That distinction matters more than it might seem. Previous theories about infrasound and paranormal experience have often leaned on anxiety as the explanatory mechanism, the idea that low-frequency sound triggers a kind of free-floating dread that the mind then reaches for supernatural explanations to account for. The new data don't really support that picture. Measures of anxiety didn't budge significantly. What went up was irritability and disinterest, a kind of sour, low-grade aversion rather than fear. That's perhaps a more honest description of how a lot of ghost stories actually feel in the telling: not screaming terror, but wrong atmosphere, a sense of unease that never quite crystallizes into something you can point at. The study has been published this week in Frontiers in Behavioral Neuroscience.

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Physicists have proposed a new kind of atomic clock based on a revived superradiant laser concept that could produce an extraordinarily stable signal with a linewidth around 100 microhertz, potentially the narrowest ever for an optical laser. "The implications of this result could stretch well beyond timekeeping," reports Phys.org. "A laser immune to environmental frequency shifts would be a powerful tool in optical interferometry -- using interference patterns in light to make ultra-precise measurements." From the report: In a conventional laser, a mirrored cavity bounces light back and forth between atoms, building up a bright, coherent beam. A superradiant laser works differently: rather than relying on the cavity to maintain coherence, the atoms themselves act as single coordinated emitters, collectively synchronizing their light emission. Following early theoretical ideas emerged in the 1990s, the concept didn't gain concrete traction until 2008, when researchers at the University of Colorado proposed that superradiant lasers could serve as a new kind of atomic clock. Atomic clocks work by using laser light to probe a very precise transition in an atom, causing electrons to transition between energy levels at an extraordinarily stable frequency. Because a superradiant laser stores its coherence in the atoms rather than the cavity, its output frequency is far less vulnerable to environmental disturbances like vibrations or temperature fluctuations. Yet although this concept was first demonstrated experimentally in 2012 in a pulsed regime, the influence of heating has so far held superradiant lasers back from their full potential. To keep the laser running continuously as an atomic clock requires, atoms must be constantly replenished with energy. Doing this atom-by-atom delivers random kicks that heat the atomic sample and disrupt the lasing process, confining it to brief pulses rather than a steady beam. In their study, Reilly's team considered whether a modification to earlier theoretical concepts could make a continuous laser suitable for an atomic clock. In almost all previous studies, atoms were treated as simple two-level systems: an electron sitting in a ground state, occasionally jumping up to an excited state and back again. The team proposed that the heating problem could be solved by adding one extra ground state to the picture. In a two-level system, if both the pumping (re-energizing) and decay processes happen collectively through the cavity, the mathematics constrains the system in a way that prevents stable, continuous lasing. But with three levels available, pumping and decay can operate on entirely separate transitions, breaking that constraint and allowing the collective approach to work. The findings have been published in the journal Physical Review Letters.

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Slashdot reader smazsyr writes: A new review says we've had fructose wrong for decades. The nine authors, led by Richard Johnson at the University of Colorado Anschutz, argue that fructose "is not just another calorie." It is a signal. It tells the liver to make fat and brace for a famine that never comes. That made sense for a bear fattening up on autumn berries. It makes less sense for a person drinking soda in March. The review reframes the WHO's sugar guideline, argues ScienceBlog.com, as "less a recommendation about calories and more a warning about a signalling molecule we have been dosing ourselves with, several times a day, for most of a century."

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An anonymous reader quotes a report from the Guardian: The critical Atlantic current system appears significantly more likely to collapse than previously thought after new research found that climate models predicting the biggest slowdown are the most realistic. Scientists called the new finding "very concerning" as a collapse would have catastrophic consequences for Europe, Africa and the Americas. The Atlantic meridional overturning circulation (Amoc) is a major part of the global climate system and was already known to be at its weakest for 1,600 years as a result of the climate crisis. Scientists spotted warning signs of a tipping point in 2021 and know that the Amoc has collapsed in the Earth's past. Climate scientists use dozens of different computer models to assess the future climate. However, for the complex Amoc system, these produce widely varying results, ranging from some that indicate no further slowdown by 2100 to those suggesting a huge deceleration of about 65%, even when carbon emissions from fossil fuel burning are gradually cut to net zero. The research combined real-world ocean observations with the models to determine the most reliable, and this hugely reduced the spread of uncertainty. They found an estimated slowdown of 42% to 58% in 2100, a level almost certain to end in collapse. The Amoc is a major part of the global climate system and brings sun-warmed tropical water to Europe and the Arctic, where it cools and sinks to form a deep return current. A collapse would shift the tropical rainfall belt on which many millions of people rely to grow their food, plunge western Europe into extreme cold winters and summer droughts, and add 50-100cm to already rising sea levels around the Atlantic. The slowdown has to do with the Arctic's rapidly rising temperatures from global warming. "Warmer water is less dense and therefore sinks into the depths more slowly," explains the Guardian. "This slowing allows more rainfall to accumulate in the salty surface waters, also making it less dense, and further slowing the sinking and forming an Amoc feedback loop." The new research has been published in the journal Science Advances.

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An anonymous reader quotes a report from the Guardian: We may appear to have little in common with sperm whales – enormous, ocean-dwelling animals that last shared a common ancestor with humans more than 90 million years ago. But the whales' vocalized communications are remarkably similar to our own, researchers have discovered. Not only do sperm whale have a form of "alphabet" and form vowels within their vocalizations but the structure of these vowels behaves in the same way as human speech, the new study has found. Sperm whales communicate in a series of short clicks called codas. Analysis of these clicks shows that the whales can differentiate vowels through the short or elongated clicks or through rising or falling tones, using patterns similar to languages such as Mandarin, Latin and Slovenian. The structure of the whales' communication has "close parallels in the phonetics and phonology of human languages, suggesting independent evolution," the paper, published in the Proceedings B journal, states. Sperm whale coda vocalizations are "highly complex and represent one of the closest parallels to human phonology of any analyzed animal communication system," it added. [...] The new study shows that "sperm whale communication isn't just about patterns of clicks -- it involves multiple interacting layers of structure," said Mauricio Cantor, a behavioral ecologist at the Marine Mammal Institute who was not involved in the research. "With this study, we're starting to see that these signals are organized in ways we didn't fully appreciate before." The latest discovery around sperm whale speech has inched forward the possibility of someday fully understanding the creatures and even communicating with them. Project CETI has set a goal of being able to comprehend 20 different vocalized expressions, relating to actions such as diving and sleeping, within the next five years. A future where we're able to fully understand what the whales are saying and be able to have a conversation with them is "totally within our grasp," said David Gruber, founder and president of Project CETI. "We've already got a lot further than I thought we could. But it will take time, and funding. At the moment we are like a two-year-old, just saying a few words. In a few years' time, maybe we will be more like a five-year-old."

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An anonymous reader quotes a report from The Guardian: They say you catch more flies with honey than vinegar. But when it comes to tackling a tricky task, researchers have found that getting angry can also be a powerful motivator. The experiments suggest people who are angry perform better on a set of challenging tasks than those who are emotionally neutral. "These findings demonstrate that anger increases effort toward attaining a desired goal, frequently resulting in greater success," said Dr Heather Lench, the first author of the study. The study, published in the Journal of Personality and Social Psychology (PDF), details how researchers at Texas A&M University conducted experiments involving more than 1,000 people, and analyzed survey data from more than 1,400 people, to explore the possible impact of anger on people in various circumstances. In one experiment, students were shown images previously found to elicit anger, desire, amusement, sadness or no particular emotion at all. Participants were subsequently asked to solve a series of anagrams. The results reveal that for a challenging set of anagrams, those who were angry did better than those in the other possible emotional states -- although no difference was seen for easy anagrams. The researchers say one explanation could be down to a link between anger and greater persistence, with the team finding those who were angry spent more time on the difficult set of anagrams. In another experiment, participants who were angry did better at dodging flags in a skiing video game than those who were neutral or sad, and were on a par with those who felt amusement or desire. "This pattern could indicate that general physical arousal had a benefit for game scores, as this would be greater in anger, amused, and desire conditions compared to the sad and neutral conditions," the researchers write. However, no such differences in performance was found when it came to an easier video game.

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