By Johann Hari Ever since I was a teenager, I have dreamed of shedding a lot of weight. So when I shrank from 203 pounds to 161 in a year, I was baffled by my feelings. I was taking Ozempic, and I was haunted by the sense that I was cheating and doing something immoral. I’m not the only one. In the United States (where I now split my time), over 70 percent of people are overweight or obese, and according to one poll, 47 percent of respondents said they were willing to pay to take the new weight-loss drugs. It’s not hard to see why. They cause users to lose an average of 10 to 20 percent of their body weight, and clinical trials suggest that the next generation of drugs (probably available soon) leads to a 24 percent loss, on average. Yet as more and more people take drugs like Ozempic, Wegovy and Mounjaro, we get more confused as a culture, bombarding anyone in the public eye who takes them with brutal shaming. This is happening because we are trapped in a set of old stories about what obesity is and the morally acceptable ways to overcome it. But the fact that so many of us are turning to the new weight-loss drugs can be an opportunity to find a way out of that trap of shame and stigma — and to a more truthful story. In my lifetime, obesity has exploded, from being rare to almost being the norm. I was born in 1979, and by the time I was 21, obesity rates in the United States had more than doubled. They have skyrocketed since. The obvious question is, why? And how do these new weight-loss drugs work? The answer to both lies in one word: satiety. It’s a concept that we don’t use much in everyday life but that we’ve all experienced at some point. It describes the sensation of having had enough and not wanting any more. The primary reason we have gained weight at a pace unprecedented in human history is that our diets have radically changed in ways that have deeply undermined our ability to feel sated. My father grew up in a village in the Swiss mountains, where he ate fresh, whole foods that had been cooked from scratch and prepared on the day they were eaten. But in the 30 years between his childhood and mine, in the suburbs of London, the nature of food transformed across the Western world. He was horrified to see that almost everything I ate was reheated and heavily processed. The evidence is clear that the kind of food my father grew up eating quickly makes you feel full. But the kind of food I grew up eating, much of which is made in factories, often with artificial chemicals, left me feeling empty and as if I had a hole in my stomach. In a recent study of what American children eat, ultraprocessed food was found to make up 67 percent of their daily diet. This kind of food makes you want to eat more and more. Satiety comes late, if at all. © 2024 The New York Times Company

Keyword: Obesity
Link ID: 29296 - Posted: 05.07.2024

By Gillian Dohrn “Puppy-dog eyes didn’t just evolve for us, in domestic dogs,” says comparative anatomist Heather Smith. Her team’s work has thrown a 2019 finding1 that the muscles in dogs’ eyebrows evolved to communicate with humans in the doghouse by showing that African wild dogs also have the muscles to make the infamous pleading expression. The study was published on 10 April in The Anatomical Record2. Now, one of the researchers who described the evolution of puppy-dog eyebrow muscles is considering what the African dog discovery means for canine evolution. “It opens a door to thinking about where dogs come from, and what they are,” says Anne Burrows, a biological anthropologist at the Duquesne University in Pittsburgh, Pennsylvania, and author of the earlier paper. The 2019 study garnered headlines around the world when it found that the two muscles responsible for creating the sad–sweet puppy-dog stare are pronounced in several domestic breeds (Canis familiaris), but almost absent in wolves (Canis lupus). If the social dynamic between humans and dogs drove eyebrow evolution, Smith wondered whether the highly social African wild dog might also have expressive brows. African wild dogs (Lycaon pictus) are native to sub-Saharan Africa. Between 1997 and 2012, their numbers dropped by half in some areas. With only 8,000 or so remaining in the wild, studying them is difficult but crucial for conservation efforts. Smith, who is based at Midwestern University in Glendale, Arizona, and her colleagues dissected a recently deceased African wild dog from Phoenix Zoo. They found that both the levator anguli oculi medalis (LAOM) and the retractor anguli oculi lateralis (RAOL) muscles, credited with creating the puppy-dog expression, were similar in size to those of domestic dog breeds.

Keyword: Emotions; Sexual Behavior
Link ID: 29295 - Posted: 05.07.2024

By Dan Falk Some years ago, when he was still living in southern California, neuroscientist Christof Koch drank a bottle of Barolo wine while watching The Highlander, and then, at midnight, ran up to the summit of Mount Wilson, the 5,710-foot peak that looms over Los Angeles. After an hour of “stumbling around with my headlamp and becoming nauseated,” as he later described the incident, he realized the nighttime adventure was probably not a smart idea, and climbed back down, though not before shouting into the darkness the last line of William Ernest Henley’s 1875 poem “Invictus”: “I am the master of my fate / I am the captain of my soul.” Koch, who first rose to prominence for his collaborative work with the late Nobel Laureate Francis Crick, is hardly the only scientist to ponder the nature of the self—but he is perhaps the most adventurous, both in body and mind. He sees consciousness as the central mystery of our universe, and is willing to explore any reasonable idea in the search for an explanation. Over the years, Koch has toyed with a wide array of ideas, some of them distinctly speculative—like the idea that the Internet might become conscious, for example, or that with sufficient technology, multiple brains could be fused together, linking their accompanying minds along the way. (And yet, he does have his limits: He’s deeply skeptical both of the idea that we can “upload” our minds and of the “simulation hypothesis.”) In his new book, Then I Am Myself The World, Koch, currently the chief scientist at the Allen Institute for Brain Science in Seattle, ventures through the challenging landscape of integrated information theory (IIT), a framework that attempts to compute the amount of consciousness in a system based on the degree to which information is networked. Along the way, he struggles with what may be the most difficult question of all: How do our thoughts—seemingly ethereal and without mass or any other physical properties—have real-world consequences? © 2024 NautilusNext Inc.,

Keyword: Consciousness
Link ID: 29294 - Posted: 05.07.2024

By Gina Kolata At 7 p.m. on May 7, 1824, Ludwig van Beethoven, then 53, strode onto the stage of the magnificent Theater am Kärntnertor in Vienna to help conduct the world premiere of his Ninth Symphony, the last he would ever complete. That performance, whose 200th anniversary is on Tuesday, was unforgettable in many ways. But it was marked by an incident at the start of the second movement that revealed to the audience of about 1,800 people how deaf the revered composer had become. Ted Albrecht, a professor emeritus of musicology at Kent State University in Ohio and author of a recent book on the Ninth Symphony, described the scene. The movement began with loud kettledrums, and the crowd cheered wildly. But Beethoven was oblivious to the applause and his music. He stood with his back to the audience, beating time. At that moment, a soloist grasped his sleeve and turned him around to see the raucous adulation he could not hear. It was one more humiliation for a composer who had been mortified by his deafness since he had begun to lose his hearing in his twenties. But why had he gone deaf? And why was he plagued by unrelenting abdominal cramps, flatulence and diarrhea? A cottage industry of fans and experts has debated various theories. Was it Paget’s disease of bone, which in the skull can affect hearing? Did irritable bowel syndrome cause his gastrointestinal problems? Or might he have had syphilis, pancreatitis, diabetes or renal papillary necrosis, a kidney disease? After 200 years, a discovery of toxic substances in locks of the composer’s hair may finally solve the mystery. © 2024 The New York Times Company

Keyword: Hearing; Neurotoxins
Link ID: 29293 - Posted: 05.07.2024

Nicola Davis Science correspondent Having two copies of a gene variant known to predispose people to Alzheimer’s could in fact represent a distinct genetic form of the disease, researchers have said. The variant, known as ApoE4, has long been known to increase the risk of developing Alzheimer’s, with two copies conferring greater risk than one. Now research has revealed almost everyone with two copies of the variant goes on to develop Alzheimer’s disease (AD), suggesting it is not only a risk factor but a cause. “Over 95% of the individuals [with two copies of ApoE4], have AD pathology either in the brain or in the biomarkers that we analysed,” said Dr Juan Fortea, the co-author of the research from the Sant Pau hospital in Barcelona. The video player is currently playing an ad. His team said the predicability of the age at which symptoms began was similar to other genetic forms of the disease such as autosomal-dominant Alzheimer’s disease (ADAD) and Alzheimer’s disease in Down syndrome (DSAD). Dr Victor Montal, a co-author from Barcelona Supercomputing Center, said the research had catalysed a paradigm shift in the understanding of the disease. “Whereas previously, the etiology of dementia was known in less than 1% of cases, our work has now enabled the identification of causative factors in over 15% of instances,” he said. However, the study did not shed light on the risk of developing dementia itself for people with two copies of ApoE4. © 2024 Guardian News & Media Limited

Keyword: Alzheimers; Genes & Behavior
Link ID: 29292 - Posted: 05.07.2024

By Elizabeth Anne Brown The beluga whale wears its heart on its sleeve — or rather, its forehead. Researchers have created a visual encyclopedia of the different expressions that belugas (Delphinapterus leucas) in captivity seem to make with their highly mobile “melon,” a squishy deposit of fat on the forehead that helps direct sound waves for echolocation. Using muscles and connective tissue, belugas can extend the melon forward until it juts over their lips like the bill of a cap; mush it down until it’s flattened against their skull; lift it vertically to create an impressive fleshy top hat; and shake it with such force that it jiggles like Jell-O. “If that doesn’t scream ‘pay attention to me,’ I don’t know what does,” says animal behaviorist Justin Richard of the University of Rhode Island in Kingston. “It’s like watching a peacock spread their feathers.” Before Richard became a scientist, he spent a decade as a beluga trainer at the Mystic Aquarium in Connecticut, working closely with the enigmatic animals. “Even as a trainer, I knew the shapes meant something,” Richard says. “But nobody had been able to put together enough observations to make sense of it.” Over the course of a year, from 2014 to 2015, Richard and colleagues recorded interactions between four belugas at the Mystic Aquarium. Analyzing the footage revealed that the belugas make five distinct melon shapes the scientists dubbed flat, lift, press, push and shake. The belugas sported an average of nearly two shapes per minute during social interaction, the team reports March 2 in Animal Cognition. © Society for Science & the Public 2000–2024

Keyword: Animal Communication; Evolution
Link ID: 29291 - Posted: 05.03.2024

By Gayathri Vaidyanathan An orangutan in Sumatra surprised scientists when he was seen treating an open wound on his cheek with a poultice made from a medicinal plant. It’s the first scientific record of a wild animal healing a wound using a plant with known medicinal properties. The findings were published this week in Scientific Reports1. “It shows that orangutans and humans share knowledge. Since they live in the same habitat, I would say that’s quite obvious, but still intriguing to realize,” says Caroline Schuppli, a primatologist at the Max Planck Institute of Animal Behavior in Konstanz, Germany, and a co-author of the study. In 2009, Schuppli’s team was observing Sumatran orangutans (Pongo abelii) in the Gunung Leuser National Park in South Aceh, Indonesia, when a young male moved into the forest. He did not have a mature male’s big cheek pads, called flanges, and was probably around 20 years old, Schuppli says. He was named Rakus, or ‘greedy’ in Indonesian, after he ate all the flowers off a gardenia bush in one sitting. In 2021, Rakus underwent a growth spurt and became a mature flanged male. The researchers observed Rakus fighting with other flanged males to establish dominance and, in June 2022, a field assistant noted an open wound on his face, possibly made by the canines of another male, Schuppli says. Days later, Rakus was observed eating the stems and leaves of the creeper akar kuning (Fibraurea tinctoria), which local people use to treat diabetes, dysentery and malaria, among other conditions. Orangutans in the area rarely eat this plant. In addition to eating the leaves, Rakus chewed them without swallowing and used his fingers to smear the juice on his facial wound over seven minutes. Some flies settled on the wound, whereupon Rakus spread a poultice of leaf-mash on the wound. He ate the plant again the next day. Eight days after his injury, his wound was fully closed. © 2024 Springer Nature Limited

Keyword: Learning & Memory; Evolution
Link ID: 29290 - Posted: 05.03.2024

By Steve Paulson These days, we’re inundated with speculation about the future of artificial intelligence—and specifically how AI might take away our jobs, or steal the creative work of writers and artists, or even destroy the human species. The American writer Meghan O’Gieblyn also wonders about these things, and her essays offer pointed inquiries into the philosophical and spiritual underpinnings of this technology. She’s steeped in the latest AI developments but is also well-versed in debates about linguistics and the nature of consciousness. O’Gieblyn also writes about her own struggle to find deeper meaning in her life, which has led her down some unexpected rabbit holes. A former Christian fundamentalist, she later stumbled into transhumanism and, ultimately, plunged into the exploding world of AI. (She currently also writes an advice column for Wired magazine about tech and society.) When I visited her at her home in Madison, Wisconsin, I was curious if I might see any traces of this unlikely personal odyssey. I hadn’t expected her to pull out a stash of old notebooks filled with her automatic writing, composed while working with a hypnotist. I asked O’Gieblyn if she would read from one of her notebooks, and she picked this passage: “In all the times we came to bed, there was never any sleep. Dawn bells and doorbells and daffodils and the side of the road glaring with their faces undone …” And so it went—strange, lyrical, and nonsensical—tapping into some part of herself that she didn’t know was there. That led us into a wide-ranging conversation about the unconscious, creativity, the quest for transcendence, and the differences between machine intelligence and the human mind. © 2024 NautilusNext Inc.,

Keyword: Consciousness; Robotics
Link ID: 29289 - Posted: 05.03.2024

By Michael S. Rosenwald Prairie voles are stocky rodents and Olympian tunnellers that surface in grassy areas to feast on grass, roots and seeds with their chisel-shaped teeth, sprouting migraines in farmers and gardeners. But to Larry Young, they were the secret to understanding romance and love. Professor Young, a neuroscientist at Emory University in Atlanta, used prairie voles in a series of experiments that revealed the chemical process for the pirouette of heart-fluttering emotions that poets have tried to put into words for centuries. He died on March 21 in Tsukuba, Japan, where he was helping to organize a scientific conference. He was 56. The cause was a heart attack, his wife, Anne Murphy, said. With their beady eyes, thick tails and sharp claws, prairie voles are not exactly cuddly. But among rodents, they are uniquely domestic: They are monogamous, and the males and females form a family unit to raise their offspring together. “Prairie voles, if you take away their partner, they show behavior similar to depression,” Professor Young told The Atlanta-Journal Constitution in 2009. “It’s almost as if there’s withdrawal from their partner.” That made them ideal for laboratory studies examining the chemistry of love. In a study published in 1999, Professor Young and his colleagues exploited the gene in prairie voles associated with the signaling of vasopressin, a hormone that modulates social behavior. They boosted vasopressin signaling in mice, which are highly promiscuous. Headline writers were amused. “Gene Swap Turns Lecherous Mice Into Devoted Mates,” The Ottawa Citizen declared. The Fort Worth Star-Telegram: “Genetic Science Makes Mice More Romantic.” The Independent in London: “‘Perfect Husband’ Gene Discovered.” © 2024 The New York Times Company

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 29288 - Posted: 05.03.2024

By Joshua Cohen In the U.S., 23 states have passed legislation to ban medicalized care for minors with gender dysphoria, or the experience of distress that can occur when a person’s gender identity does not match the sex they were assigned at birth. On the other hand, 12 state legislatures have introduced laws to protect access to youth transgender care. Such care can include puberty blockers, which are medications that suppress the body’s production of sex hormones, and cross-sex hormones like testosterone or estrogen that alter secondary sex characteristics. It also may include sexual reassignment surgery in rare instances. U.S. policies on both ends of the spectrum are not science-driven but rather emanate from polar-opposite ideologies. Unlike in Europe, there doesn’t appear to be room for a non-ideological process for determining what the best care is that weighs the emerging clinical evidence and adjusts policies accordingly. As reported in Axios, state efforts to restrict various forms of transgender medicine are being fueled by religious groups that aim to shape policy based on their strongly held beliefs around the immutability of gender and family. Faith-based objections to transgender care come from a worldview in which God created humans as male or female. Here, the role of parents’ rights features prominently, as well as a conviction that adolescents are insufficiently mature to decide on trans alterations to their bodies. Moreover, lawmakers point out that some young people later regret having had irreversible body-altering treatment. The bans on care can be driven by extreme religious views. In one example, The Associated Press reported last year that Oklahoma state Sen. David Bullard introduced what he called the “Millstone Act” — a bill that would make the act of providing gender transition procedures to anyone under the age of 26 a felony — by citing a Bible passage that suggests those who cause children to sin should be drowned. The age limit was later lowered to 18.

Keyword: Sexual Behavior
Link ID: 29287 - Posted: 05.03.2024

By Giorgia Guglielmi A population of neurons in the brain stem, the stalk-like structure that connects the bulk of the brain to the spinal cord, acts as the master dial for the immune system.Credit: Voisin/Phanie/Science Photo Library Scientists have long known that the brain plays a part in the immune system — but how it does so has been a mystery. Now, scientists have identified cells in the brainstem that sense immune cues from the periphery of the body and act as master regulators of the body’s inflammatory response. The results, published on 1 May in Nature1, suggest that the brain maintains a delicate balance between the molecular signals that promote inflammation and those that dampen it — a finding that could lead to treatments for autoimmune diseases and other conditions caused by an excessive immune response. The discovery is akin to a black-swan event — unexpected but making perfect sense once revealed, says Ruslan Medzhitov, an immunologist at Yale University in New Haven, Connecticut. Scientists have known that the brainstem has many functions, such as controlling basic processes such as breathing. However, he adds, the study “shows that there is whole layer of biology that we haven’t even anticipated”. The brain is watching After sensing an intruder, the immune system unleashes a flood of immune cells and compounds that promote inflammation. This inflammatory response must be controlled with exquisite precision: if it’s too weak, the body is at greater risk of becoming infected; if it’s too strong, it can damage the body’s own tissues and organs. Previous work has shown that the vagus nerve, a large network of nerve fibres that links the body with the brain, influences immune responses. However, the specific brain neurons that are activated by immune stimuli remained elusive, says Hao Jin, a neuroimmunologist at the US National Institute of Allergy and Infectious Diseases in Bethesda, Maryland, who led the work. © 2024 Springer Nature Limited

Keyword: Neuroimmunology
Link ID: 29286 - Posted: 05.02.2024

By Dan Falk Daniel Dennett, who died in April at the age of 82, was a towering figure in the philosophy of mind. Known for his staunch physicalist stance, he argued that minds, like bodies, are the product of evolution. He believed that we are, in a sense, machines—but astoundingly complex ones, the result of millions of years of natural selection. Dennett wrote more than a dozen books, some of them aimed at a scholarly audience but many of them directed squarely at the inquisitive non-specialist—including bestsellers like Consciousness Explained, Breaking the Spell, and Darwin’s Dangerous Idea. Reading his works, one gets the impression of a mind jammed to the rafters with ideas. As Richard Dawkins put it in a blurb for Dennett’s last book, a memoir titled I’ve Been Thinking: “How unfair for one man to be blessed with such a torrent of stimulating thoughts.” Dennett spent decades puzzling over the existence of minds. How does non-thinking matter arrange itself into matter that can think, and even ponder its own existence? A long-time academic nemesis of Dennett’s, the philosopher David Chalmers, dubbed this the “Hard Problem” of consciousness. But Dennett felt this label needlessly turned a series of potentially-solvable problems into one giant unsolvable one: He was sure the so-called hard problem would evaporate once the various lesser (but still difficult) problems of understanding the brain’s mechanics were figured out. Because he viewed brains as miracle-free mechanisms, he saw no barrier to machine consciousness, at least in principle. Yet he had no fear of Terminator-style AI doomsday scenarios, either. (“The whole singularity stuff, that’s preposterous,” he once told an interviewer for The Guardian. “It distracts us from much more pressing problems.”) © 2024 NautilusNext Inc.,

Keyword: Consciousness; Attention
Link ID: 29285 - Posted: 05.02.2024

By J. David Creswell Let’s start thinking differently about exercise. Decades of exercise science research show that when people or animals are given a new exercise routine, they get healthier. But when thinking about the benefits of exercise, most people hold a strong body bias; they focus on how regular exercise builds more lean body mass, helps increase their strength and balance, or improves heart health. Exercise matters even more for our brains, it turns out, in ways that are often overlooked. Here’s how we know. Animal exercise studies typically run rats for weeks on running wheels. The animals gleefully run every night, sprinting several miles over the course of an evening. There are wonderful health benefits in these studies of voluntary running—improved muscle tone and cardiovascular health, and many brain benefits too. But in some studies, there’s an additional experimental condition where some rats exercise with one crucial difference: it’s no longer voluntary exercise. Instead of a freestanding running wheel, rats run on a mechanized wheel that spins, forcing the animals to cover the same distance as the voluntary runners. What happens? When the rats are forced to exercise on a daily basis for several weeks, their bodies become more physically fit, but their brains suffer. Animals regularly forced to exercise have the equivalent of an anxiety disorder, behaving on new tasks in highly anxious and avoidant ways. These animals are more anxious not only compared to the voluntary runners, but also to animals that are not given an opportunity to exercise at all. Yes, forced exercise might be worse than no exercise at all. This work suggests something important about the health benefits of exercise: it is not just about making our muscles work, but what exercise does to our brains. When exercise gives us a sense of control, mastery and joy, our brains become less anxious. If we take that away, by forcing exercise, we can shift it from helpful to harmful. © 2024 SCIENTIFIC AMERICAN,

Keyword: Stress; Depression
Link ID: 29284 - Posted: 05.02.2024

By Eileen Sullivan, Glenn Thrush and Zolan Kanno-Youngs The Justice Department said on Tuesday that it had recommended easing restrictions on marijuana in what could amount to a major change in federal policy. Even though the move, which kicks off a lengthy rule-making process, does not end the criminalization of the drug, it is a significant shift in how the government views the safety and use of marijuana for medical purposes. It also reflects the Biden administration’s effort to liberalize marijuana policy in a way that puts it more in line with the public as increasingly more Americans favor legalizing the drug. The decision comes at an opportune time for President Biden, who is trailing the presumptive Republican nominee, former President Donald J. Trump, as they approach the November election, according to a recent CNN poll. It could also lead to the softening of other laws and regulations that account for the use or possession of cannabis, including sentencing guidelines, banking and access to public housing. People familiar with the recommendation, speaking on the condition of anonymity, said Attorney General Merrick B. Garland planned to tell the White House Office of Management and Budget that the government should change the drug’s categorization. After the office assesses the recommendation, it will still face a long road before taking effect, including being subject to public comment. The Associated Press earlier reported the Justice Department decision. For more than half a century, marijuana has been considered a Schedule I drug, classified on the same level as highly addictive substances like heroin that the Drug Enforcement Administration describes as having no currently accepted medical use. Moving marijuana to Schedule III, as the Department of Health and Human Services recommended in August, would put it alongside less addictive substances like Tylenol with codeine, ketamine and testosterone, meaning that it would be subject to fewer restrictions on production and research, and that eventually it could be prescribed by a doctor. © 2024 The New York Times Company

Keyword: Drug Abuse
Link ID: 29283 - Posted: 05.02.2024

By Sabrina Malhi The phrase “anger kills” might have a more literal meaning: New research suggests a possible reason frequent anger has been linked to an increased risk of cardiovascular disease. The study, published Wednesday in the Journal of the American Heart Association, emphasizes the potential health risks associated with intense anger and illuminates the influence of negative emotions on our overall well-being. Funded by the National Institutes of Health, the study involved 280 healthy adults who were randomly assigned to a different eight-minute task, each designed to elicit feelings of anger, anxiety, sadness or neutrality. Before and after these emotional tasks, researchers assessed the participants’ endothelial health. Endothelial cells, which line the insides of blood vessels, are essential for maintaining vessel integrity and are vital for proper circulation and cardiovascular health. The findings revealed that anger had a significant negative impact on endothelial function, limiting the blood vessels’ ability to dilate. The response was not as pronounced with anxiety or sadness. According to Daichi Shimbo, a cardiologist and professor of medicine at Columbia University Irving Medical Center and the lead study author, this research marks a step toward understanding how different negative emotions particularly affect physical health. “It's fascinating that anxiety and sadness did not have the same effect as anger, suggesting that the ways in which negative emotions contribute to heart disease differ,” Shimbo said.

Keyword: Emotions; Stress
Link ID: 29282 - Posted: 05.02.2024

In 2023, students protested against a new policy in Texas, where parents would be notified if their child asks to be identified as transgender.Credit: Brett Coomer/Houston Chronicle/Getty This week, Nature is launching a collection of opinion articles on sex and gender in research. Further articles will be published in the coming months. The series will highlight the necessity and challenges of studying a topic that is both hugely under-researched and, increasingly, the focus of arguments worldwide — many of which are neither healthy nor constructive. Some scientists have been warned off studying sex differences by colleagues. Others, who are already working on sex or gender-related topics, are hesitant to publish their views. Such a climate of fear and reticence serves no one. To find a way forward we need more knowledge, not less. Nearly 20 researchers from diverse fields, including neuroscience, psychology, immunology and cancer, have contributed to the series, which provides a snapshot of where scholars studying sex and gender are aligned — and where they are not. In time, we hope this collection will help to shape research, and provide a reference point for moderating often-intemperate debates. In practice, people use sex and gender to mean different things. But researchers studying animals typically use sex to refer to male and female individuals, as defined by various anatomical and other biological features. In studies involving humans, participants are generally asked to identify their own sex and/or gender category. Here, gender usually encompasses social and environmental factors, including gender roles, expectations and identity. © 2024 Springer Nature Limited

Keyword: Sexual Behavior
Link ID: 29281 - Posted: 05.02.2024

By Dana G. Smith When it comes to aging, we tend to assume that cognition gets worse as we get older. Our thoughts may slow down or become confused, or we may start to forget things, like the name of our high school English teacher or what we meant to buy at the grocery store. But that’s not the case for everyone. For a little over a decade, scientists have been studying a subset of people they call “super-agers.” These individuals are age 80 and up, but they have the memory ability of a person 20 to 30 years younger. Most research on aging and memory focuses on the other side of the equation — people who develop dementia in their later years. But, “if we’re constantly talking about what’s going wrong in aging, it’s not capturing the full spectrum of what’s happening in the older adult population,” said Emily Rogalski, a professor of neurology at the University of Chicago, who published one of the first studies on super-agers in 2012. A paper published Monday in the Journal of Neuroscience helps shed light on what’s so special about the brains of super-agers. The biggest takeaway, in combination with a companion study that came out last year on the same group of individuals, is that their brains have less atrophy than their peers’ do. The research was conducted on 119 octogenarians from Spain: 64 super-agers and 55 older adults with normal memory abilities for their age. The participants completed multiple tests assessing their memory, motor and verbal skills; underwent brain scans and blood draws; and answered questions about their lifestyle and behaviors. The scientists found that the super-agers had more volume in areas of the brain important for memory, most notably the hippocampus and entorhinal cortex. They also had better preserved connectivity between regions in the front of the brain that are involved in cognition. Both the super-agers and the control group showed minimal signs of Alzheimer’s disease in their brains. © 2024 The New York Times Company

Keyword: Learning & Memory; Development of the Brain
Link ID: 29280 - Posted: 04.30.2024

By Tim Vernimmen Most amphibians aren’t exactly doting parents — they just find a partner and release as many eggs or sperm as possible, in hopes that viable larvae will hatch from at least some fertilized eggs, and at least some of those larvae will survive to adulthood. Yet in as many as one in five amphibian species, one or both parents stick around to care for their offspring, using a staggering variety of strategies. The most well-known amphibian parents are the brightly colored poison frogs, a group of around 200 species that will repeatedly be leaping into view in this article. Yet their parenting skills may not be as exceptional as once thought, says biologist Jennifer Stynoski of the University of Costa Rica, who decided to study this group when she spotted them on a field trip as a student years ago. “I think they’ve just received a lot of attention because they’re so beautiful. They’re very cute to study.” So — what makes an exemplary amphibian parent? Much remains to be discovered, but some common principles have emerged. Stay away from the water Unlike reptiles and the birds that evolved from them, the ancestors of today’s amphibians never developed eggs with tough, watertight shells. This means their eggs need water to survive, as do the gilled larvae that usually come wriggling out. Yet the ponds in which many amphibians deposit their eggs are full of other animals, many eager to supplement their diet by slurping up a mouthful of eggs. “This must be one reason why so many species have evolved ways to lay their eggs away from the water,” says behavioral ecologist Eva Ringler of the University of Bern in Switzerland. © 2024 Annual Reviews

Keyword: Sexual Behavior; Evolution
Link ID: 29279 - Posted: 04.30.2024

By Kristen French Combat in nature is often a matter of tooth and claw, fang and talon. But some creatures have devised devious and dramatic ways to weaponize their bodily fluids, expelling them in powerful streams for the purposes of attack or self-defense. Researcher Elio Challita became fascinated by fluid ejections in nature when he began studying an insect called the sharpshooter, which pees one droplet at a time using a method called superpropulsion. These insects consume 300 times their own body weight per day in xylem sap, a watery solution of minerals and other nutrients found in the roots, stems, and leaves of plants. To efficiently expel the resulting waste, they use a kind of internal catapult that helps overcome the surface tension in the droplets. Challita and a team of researchers from the Bhamla Lab at Georgia Tech decided to survey the biomechanics and fluid dynamics that govern fluid ejections across the animal kingdom to see what commonalities they could find. Among others, they identified a number of creatures that use bodily fluids as powerful weapons in the fight for survival. These fluid ejections defy gravity and rebel against traditional notions of predator-prey tactics. The team’s review, “Fluid Ejections in Nature,” is forthcoming in the Annual Review of Chemical and Biological Engineering. 1. Ringnecked Spitting Cobra Cobras of the Naja genus defend against threats by spitting venom with extreme precision toward the eyes of an enemy, up to 6.5 feet away. These snakes release the venom through hollow microscopic fangs and can adjust the distribution of their spit with rapid movements. Spitting cobras have a venom discharge orifice that is more circular in shape than non-spitting species, which gives the venom more forward force. Contraction in the venom gland also helps. A 90-degree bend near the lip of the orifice gives the snake more precise control over venom flow. Naja pallida cobras can spit venom at average speeds of 1.27 milliliters per second. © 2024 NautilusNext Inc.,

Keyword: Neurotoxins; Evolution
Link ID: 29278 - Posted: 04.30.2024

Jon Hamilton Scientists have found a way to restore brain cells impaired by a rare and life-threatening genetic disorder called Timothy syndrome. A type of drug known as an antisense oligonucleotide allowed clusters of human neurons to develop normally even though they carried the mutation responsible for Timothy syndrome, a team reports in the journal Nature. The approach may help researchers develop treatments for other genetic conditions, including some that cause schizophrenia, epilepsy, ADHD, and autism spectrum disorder. "It's immensely exciting because we now have the tools," says Dr. Sergiu Pasca, a professor of psychiatry and behavioral sciences at Stanford University and the study's senior author. "It's the beginning of a new era for many of these diseases that we first thought were untreatable," says Dr. Huda Zoghbi, a professor at Baylor College of Medicine who was not involved in the research. But most of these conditions involve multiple genes, not just one — and scientists don't yet know enough about these multiple gene disorders to effectively treat them with antisense oligonucleotides, Zoghbi says. Timothy Syndrome has been diagnosed in fewer than 100 people worldwide. Children born with it often have heart problems, autism, epilepsy, developmental delay, and intellectual disability. But because Timothy syndrome is caused by a mutation in a single gene, it offers scientists a way to study changes that affect brain development. "Rare syndromes that are very clearly defined genetically are sort of like windows, or Rosetta Stones, into understanding other, more common conditions," Pasca says. © 2024 npr

Keyword: Autism; Genes & Behavior
Link ID: 29277 - Posted: 04.30.2024