By Elizabeth Pennisi Males resort to all sorts of desperate measures when fertile females are scarce, including banding together to guard a potential mate. Now, researchers have discovered that such bands of bottlenose dolphins may coordinate their actions with unique “popping” calls—the first evidence that animals other than humans can synchronize themselves using vocal signals. Humans often use vocal signals to coordinate actions, like marching and dancing, that reinforce unity and intimidate outside groups. The synchronized displays of other animals—like fireflies that light up at the same time—are thought to be competitive, showing off which male is the sexiest, rather than cooperative. In Shark Bay, off the coast Western Australia 800 kilometers north of Perth, groups of up to 14 male dolphins form lifelong alliances. Together, subsets of three keep close tabs on potential female mates, swimming, turning, and surfacing in unison to guard and herd them—one female at a time. Scientists watching this behavior noticed these males often emit a unique “popping” call, making series of two to 49 very short sounds, 10 per second, over and over. e dolphins popping The scientists dragged four underwater microphones behind a motorboat and recorded 172 instances in which multiple males were “popping” together (above). When the males pop alone, their timing and tempo varies. But when they pop together, they do it at the same time and at the same rate, suggesting they are using the sounds to enhance their cooperation, the team reports today in the Proceedings of the Royal Society B. This synchronized popping may be a threat, as it tends to make the female dolphin move closer to her male guards. But more importantly, the researchers say, it may help reinforce that the males need to act—and talk—as one to ensure they get their gal. © 2020 American Association for the Advancement of Science

Keyword: Sexual Behavior; Aggression
Link ID: 27156 - Posted: 04.01.2020

Nicola Davis Reading minds has just come a step closer to reality: scientists have developed artificial intelligence that can turn brain activity into text. While the system currently works on neural patterns detected while someone is speaking aloud, experts say it could eventually aid communication for patients who are unable to speak or type, such as those with locked in syndrome. “We are not there yet but we think this could be the basis of a speech prosthesis,” said Dr Joseph Makin, co-author of the research from the University of California, San Francisco. Writing in the journal Nature Neuroscience, Makin and colleagues reveal how they developed their system by recruiting four participants who had electrode arrays implanted in their brain to monitor epileptic seizures. These participants were asked to read aloud from 50 set sentences multiple times, including “Tina Turner is a pop singer”, and “Those thieves stole 30 jewels”. The team tracked their neural activity while they were speaking. This data was then fed into a machine-learning algorithm, a type of artificial intelligence system that converted the brain activity data for each spoken sentence into a string of numbers. To make sure the numbers related only to aspects of speech, the system compared sounds predicted from small chunks of the brain activity data with actual recorded audio. The string of numbers was then fed into a second part of the system which converted it into a sequence of words. © 2020 Guardian News & Media Limited

Keyword: Language; Brain imaging
Link ID: 27155 - Posted: 03.31.2020

By Stephen Casper. The poet Emily Dickinson rendered the brain wider than the sky, deeper than the sea, and about the weight of God. Scientists facing the daunting task of describing this organ conventionally conjure up different kinds of metaphor — of governance; of maps, infrastructure networks and telecommunications; of machines, robots, computers and the Internet. The comparisons have been practical and abundant. Yet, perhaps because of their ubiquity, the metaphors we use to understand the brain often go unnoticed. We forget that they are descriptors, and see them instead as natural properties. Such hidden dangers are central to biologist and historian Matthew Cobb’s The Idea of the Brain. This ambitious intellectual history follows the changing understanding of the brain from antiquity to the present, mainly in Western thought. Cobb outlines a growing challenge to the usefulness of metaphor in directing and explaining neuroscience research. With refreshing humility, he contends that science is nowhere near working out what brains do and how — or even if anything is like them at all. Cobb shows how ideas about the brain have always been forged from the moral, philosophical and technological frameworks to hand for those crafting the dominant narratives of the time. In the seventeenth century, the French philosopher René Descartes imagined an animal brain acting through hydraulic mechanisms, while maintaining a view of the divine nature of a mind separate from matter. Later authorities, such as the eighteenth-century physician and philosopher Julien Offray de Le Mettrie, secularized the image and compared the human to a machine. The Italian physicist Alessandro Volta rejected the idea of ‘animal electricity’, proposed by his rival Luigi Galvani as a vital force that animates organic matter. Volta was driven at least partly by his aversion to the mechanistic view. © 2020 Springer Nature Limited

Keyword: Brain imaging
Link ID: 27154 - Posted: 03.31.2020

By Sheila Kaplan, Andrew Jacobs and Choe Sang-Hun In January 2019, the chairman of Altria, Howard A. Willard III, flew to Silicon Valley to speak to senior executives of Juul Labs, fresh off signing a deal for the tobacco giant to pay nearly $13 billion for a 35 percent stake in the popular e-cigarette company. With public fury growing over Juul’s contribution to the epidemic of teenage vaping, he laid out his vision for the company to continue to thrive. “I believe that in five years, 50 percent of Juul’s revenue will be international,” Mr. Willard told the 200 executives gathered at the Four Seasons in East Palo Alto. Kevin Burns, Juul’s chief executive at the time, interrupted: “I told the team to accomplish that in one year!” Many people in audience chuckled, but a year later, nobody is laughing. When the big American tobacco companies started feeling pressure decades ago, they found new markets and friendlier regulation abroad. Juul’s efforts to follow the same playbook have been stunningly unsuccessful. The company has been met with ferocious anti-vaping sentiment and a barrage of newly enacted e-cigarette restrictions, or outright bans, in country after country. As a result, its ambitious overseas plans have collapsed. Juul was kicked off the market in China last fall after just four days. The company has had to abandon plans for India after the government there banned all electronic cigarettes. Thailand, Singapore, Cambodia and Laos have also closed the door to e-cigarettes. In the Philippines, President Rodrigo Duterte ordered the arrest of anyone caught vaping outside designated smoking areas. Juul has postponed its launch in the Netherlands and has pulled out of Israel. In South Korea, the number of Juul customers has plummeted after the government issued dire health warnings about e-cigarettes, and the company has scaled back its distribution there. © 2020 The New York Times Company

Keyword: Drug Abuse
Link ID: 27153 - Posted: 03.31.2020

A first-of-its-kind trial has demonstrated that a receptor involved in the brain’s reward system may be a viable target for treating anhedonia (or lack of pleasure), a key symptom of several mood and anxiety disorders. This innovative fast-fail trial was funded by the National Institute of Mental Health (NIMH), part of the National Institutes of Health, and the results of the trial are published in Nature Medicine. Mood and anxiety disorders are some of the most commonly diagnosed mental disorders, affecting millions of people each year. Despite this, available medications are not always effective in treating these disorders. The need for new treatments is clear, but developing psychiatric medications is often a resource-intensive process with a low success rate. To address this, NIMH established the Fast-Fail Trials program with the goal of enhancing the early phases of drug development. “The fast-fail approach aims to help researchers determine — quickly and efficiently — whether targeting a specific neurobiological mechanism has the hypothesized effect and is a potential candidate for further clinical trials,” explained Joshua A. Gordon, M.D., Ph.D., director of NIMH. “Positive results suggest that targeting a neurobiological mechanism affects brain function as expected, while negative results allow researchers to eliminate that target from further consideration. We hope this approach will pave the way towards the development of new and better treatments for individuals with mental illnesses.” In this study, researcher Andrew D. Krystal, M.D., who began the research while at the Duke University School of Medicine, Durham, North Carolina, and is now at the University of California, San Francisco, and colleagues report the first comprehensive application of this fast-fail approach. The researchers examined the kappa opioid receptor (KOR) as a possible neurobiological target for the treatment of anhedonia. Previous findings suggest that drugs that block the KOR, known as KOR antagonists, can affect reward-related brain circuits in ways that could improve reward processing and reverse anhedonia and associated symptoms.

Keyword: Depression
Link ID: 27152 - Posted: 03.31.2020

by Laura Dattaro / Mice missing an autism gene called SHANK3 respond to much lighter touches than typical mice do, according to a new study1. And this hypersensitivity seems to result from the underactivity of neurons that normally dampen sensory responses. The study is the first to examine sensory sensitivity in mice missing SHANK3. Mice with mutations in other genes tied to autism, including MECP2 and GABRB3, have also been shown to be hypersensitive to puffs of air blown onto their backs. Up to 90 percent of autistic people have sensory problems, including hypersensitivity to sensations such as sound or touch. These disruptions may underlie many of the difficulties autistic people face in navigating the world, says lead investigator Guoping Feng, professor of neuroscience at the Massachusetts Institute of Technology. “Sensory overload is one of the reasons that autistic people cover their ears, [hide] in corners, want to be quiet,” Feng says. “It’s important to understand mechanisms.” Up to 2 percent of people with autism have a mutation in SHANK3, which encodes a protein needed for neurons to communicate with one another2. Autism is also common in people with Phelan-McDermid syndrome, a condition caused by deletions of the chromosomal region in which SHANK3 is located. Other experts also say the study underscores the importance of studying sensory problems in autistic people. “Hyperreactivity to sensory input might be connected with autism in a really deep way,” says Sam Wang, professor of neuroscience at Princeton University, who was not involved in the work. “If sensory experience in the first few years of life is necessary for setting up a model of the world, an understanding of the world, then sensory processing would be a gateway to all kinds of other difficulties.” © 2020 Simons Foundation

Keyword: Autism; Attention
Link ID: 27151 - Posted: 03.30.2020

By Erika Mailman In summer 2014, when he was 54, Sacramento artist David Wetzl was exhibiting the behaviors of an elderly man with Alzheimer’s. “I have a bad brain,” he told everyone repeatedly, using a simple phrase to explain his diagnosis to the world. Two years before that, his wife, Diana Daniels, had asked for an MRI because she was suspicious that things weren’t right and fearful when he couldn’t remember the word “shoelaces.” The scan showed with horrific clarity how sections of his brain had shriveled. “The devastation began on his left temporal lobe, working its greatest damage,” says Diana. “By the time of diagnosis, his right temporal lobe also had significant atrophy.” David was diagnosed with frontotemporal dementia, or FTD, part of a group of disorders caused by nerve cell damage to the brain. The disease comes with a dispiriting prognosis. There is no cure (although symptoms can be treated), and patients usually die within seven to 13 years from the onset of symptoms. As FTD progresses, behavior can become strange and antisocial, says Matt Ozga, communications manager at the Association for Frontotemporal Degeneration in King of Prussia, Pa. Patients lose their filter and can make embarrassing remarks. For the spouses who are caught off guard, thinking their mate’s worst setback for the next few decades will be graying hair and a paunch, it’s a shock. The couple may find themselves confronted  by different challenges than those who encounter dementia later in life.

Keyword: Alzheimers
Link ID: 27150 - Posted: 03.30.2020

Stephanie Preston The media is replete with COVID-19 stories about people clearing supermarket shelves – and the backlash against them. Have people gone mad? How can one individual be overfilling his own cart, while shaming others who are doing the same? As a behavioral neuroscientist who has studied hoarding behavior for 25 years, I can tell you that this is all normal and expected. People are acting the way evolution has wired them. The word “hoarding” might bring to mind relatives or neighbors whose houses are overfilled with junk. A small percentage of people do suffer from what psychologists call “hoarding disorder,” keeping excessive goods to the point of distress and impairment. But hoarding is actually a totally normal and adaptive behavior that kicks in any time there is an uneven supply of resources. Everyone hoards, even during the best of times, without even thinking about it. People like to have beans in the pantry, money in savings and chocolates hidden from the children. These are all hoards. Most Americans have had so much, for so long. People forget that, not so long ago, survival often depended on working tirelessly all year to fill root cellars so a family could last through a long, cold winter – and still many died. Similarly, squirrels work all fall to hide nuts to eat for the rest of the year. Kangaroo rats in the desert hide seeds the few times it rains and then remember where they put them to dig them back up later. A Clark’s nutcracker can hoard over 10,000 pine seeds per fall – and even remember where it put them. © 2010–2020, The Conversation US, Inc.

Keyword: Obesity; Attention
Link ID: 27149 - Posted: 03.30.2020

Researchers at the National Institutes of Health have discovered in mice what they believe is the first known genetic mutation to improve cognitive flexibility—the ability to adapt to changing situations. The gene, KCND2, codes for a protein that regulates potassium channels, which control electrical signals that travel along neurons. The electrical signals stimulate chemical messengers that jump from neuron to neuron. The researchers were led by Dax Hoffman, Ph.D., chief of the Section on Neurophysiology at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). It appears in Nature Communications. The KCND2 protein, when modified by an enzyme, slows the generation of electrical impulses in neurons. The researchers found that altering a single base pair in the KCND2 gene enhanced the ability of the protein to dampen nerve impulses. Mice with this mutation performed better than mice without the mutation in a cognitive task. The task involved finding and swimming to a slightly submerged platform that had been moved to a new location. Mice with the mutation found the relocated platform much faster than their counterparts without the mutation. The researchers plan to investigate whether the mutation will affect neural networks in the animals’ brains. They added that studying the gene and its protein may ultimately lead to insights on the nature of cognitive flexibility in people. It also may help improve understanding of epilepsy, schizophrenia, Fragile X syndrome, and autism spectrum disorder, which all have been associated with other mutations in KCND2.

Keyword: Learning & Memory; Genes & Behavior
Link ID: 27148 - Posted: 03.30.2020

By Nicholas Bakalar There is good evidence that a daily baby aspirin reduces the risk for heart disease and stroke, and some have thought its inflammation-lowering effect might also help in delaying cognitive decline. But taking a daily low-dose aspirin did not appear to be effective in lowering the risk of Alzheimer’s disease or other forms of dementia, a new study reports. For the study, in Neurology, researchers set up a controlled trial with 19,114 men and women older than 70 who were free of cardiovascular disease and dementia at the start. Half were randomly assigned to take a daily 100-milligram aspirin, while the other half took a placebo. After an average follow-up of almost five years with annual examinations, the researchers found no difference between the groups in diagnoses of Alzheimer’s disease or mild cognitive impairment. They did find declining cognitive function over time, but the speed and degree of that decline was the same in both groups. The researchers found no effect in various subgroups either — people with hypertension or diabetes, smokers or people with high cholesterol, or those who were overweight or obese. A limitation of the study was that patients were followed for less than five years. “If you’re 70 or older and healthy, without evidence of cardiovascular disease, it’s very difficult to improve on your success. The relatively low risk of dementia in this study was not further lowered with aspirin,” said a co-author, Dr. Anne B. Newman, a professor of epidemiology at the University of Pittsburgh. © 2020 The New York Times Company

Keyword: Alzheimers
Link ID: 27147 - Posted: 03.30.2020

By Julie Halpert As the coronavirus advances, it is taking a particularly harsh toll on the many who are caring for a loved one with dementia or Alzheimer’s, the most common form of dementia. According to a report by the Alzheimer’s Association, more than 16 million Americans are providing unpaid care for those with Alzheimer’s or other types of dementia. For them the virus is “really a double whammy,” said Lynn Friss Feinberg, a senior strategic policy adviser at AARP’s Public Policy Institute. “You’re worrying about your own health and that of your family member.” While the disease itself does not necessarily place patients at high risk for contracting the virus, they and their caregivers face a range of special challenges. Dementia patients are typically very sensitive to changes in routine and often require a great deal of hands-on care, both factors that are hard to manage now. Family members who usually rely on day care programs or visiting caregivers may be finding themselves with full-time responsibilities, while others whose loved ones are in facilities are unable to visit them now. Among the greatest challenges is how to minimize disruption in care that is intensely personal. “Care for dementia patients is ‘high touch,’” said Peter Lichtenberg, a professor of psychology and director of the Institute of Gerontology at Wayne State University. He recommends that caregivers take measures to avoid their own exposures by having provisions delivered, disinfecting surfaces and employing proper hand-washing techniques. K.C. Mehta has been caring for his wife, Sumi, since 2013, when she was given a diagnosis of Alzheimer’s at the age of 59. A former engineering executive at Chrysler, Mr. Mehta, who is 72 and lives in Rochester Hills, Mich., spends each day focused on maintaining his wife’s routine. Twice during the night, he changes her diaper. When she awakes, he bathes and dresses her. © 2020 The New York Times Company

Keyword: Alzheimers
Link ID: 27146 - Posted: 03.27.2020

By Douglas Starr When Jennifer Eberhardt appeared on The Daily Show with Trevor Noah in April 2019, she had a hard time keeping a straight face. But some of the laughs were painful. Discussing unconscious racial bias, which she has studied for years, the Stanford University psychologist mentioned the “other-race effect,” in which people have trouble recognizing faces of other racial groups. Criminals have learned to exploit the effect, she told Noah. In Oakland, California, a gang of black teenagers caused a mini–crime wave of purse snatchings among middle-aged women in Chinatown. When police asked the teens why they targeted that neighborhood, they said the Asian women, when faced with a lineup, “couldn’t tell the brothers apart.” “That is one of the most horrible, fantastic stories ever!” said Noah, a black South African. But it was true. Eberhardt has written that the phrase “they all look alike,” long the province of the bigot, “is actually a function of biology and exposure.” There’s no doubt plenty of overt bigotry exists, Eberhardt says; but she has found that most of us also harbor bias without knowing it. It stems from our brain’s tendency to categorize things—a useful function in a world of infinite stimuli, but one that can lead to discrimination, baseless assumptions, and worse, particularly in times of hurry or stress. Over the decades, Eberhardt and her Stanford team have explored the roots and ramifications of unconscious bias, from the level of the neuron to that of society. In cleverly designed experiments, she has shown how social conditions can interact with the workings of our brain to determine our responses to other people, especially in the context of race. Eberhardt’s studies are “strong methodologically and also super real-world relevant,” says Dolly Chugh of New York University’s Stern School of Business, a psychologist who studies decision-making. © 2020 American Association for the Advancement of Science.

Keyword: Attention; Emotions
Link ID: 27145 - Posted: 03.27.2020

By Adam Popescu Many people spend their nights now tossing and turning, struggling to unglue from the constant scroll of coronavirus news updates. But, while there is no body or life hack to make you impervious to the touch of disease, we do know that sleep is key to helping our bodies stay healthy. “Sleep is an essential part of protection from and response to any infection,” said Douglas B. Kirsch, a neurologist and former president of the American Academy of Sleep Medicine. But still, he hears you: “Sleep is hard when anxiety levels are high, such as in the case of a pandemic.” There are some answers as to what you can do now. You may not like them. Create and maintain a very consistent sleep practice and schedule that works for you. The more consistent your wake-up time, the more consistent your body functions. The National Sleep Foundation recommends sticking to a sleep schedule, and here’s a simple way to do it: Set a regular bedtime. Pair it with a set time to wake. (As many people aren’t currently commuting, this might be easier than normal.) Set yourself up for success by doing the little things: use blackout curtains if you’re sleeping while it’s bright, ditto to earplugs or a sleep mask (Wirecutter, a company owned by The New York Times that judges products, recommends this sleep mask, but even a light pillow or T-shirt works in a pinch). No matter what you do, make your bedroom very comfortable and very dark. Are you easily awakened? Use a fan or a repeated track on Spotify for white noise. Still, if you’re tired, get sleep while you can. “If you’re tired during the day, get your rest then,” said Janet Mullington, a professor in the department of neurology at Harvard Medical School. © 2020 The New York Times Company

Keyword: Sleep
Link ID: 27144 - Posted: 03.27.2020

Richard Masland The eye is something like a camera, but there is a whole lot more to vision than that. One profound difference is that our vision, like the rest of our senses, is malleable and modifiable by experience. Take the commonplace observation that people deprived of one sense may have a compensatory increase in others — for example, that blind people have heightened senses of hearing and touch. A skeptic could say that this was just a matter of attention, concentration and practice at the task, rather than a true sensory improvement. Indeed, experiments show that a person’s sensory acuity can achieve major improvement with practice. Yet with modern methodologies, neuroscientists have conclusively proved that the circuits of the brain neurons do physically change. Our senses are malleable because the sensory centers of the brain rewire themselves to strike a useful balance between the capacities of the available neural resources and the demands put on them by incoming sensory impressions. Studies of this phenomenon are revealing that some sensory areas have innate tendencies toward certain functions, but they show just as powerfully the plasticity of the developing brain. Take a rat that has been deprived of vision since birth — let’s say because of damage to both retinas. When the rat grows up, you train that rat to run a maze. Then you damage the visual cortex slightly. You ask the rat to run the maze again and compare its time before the operation and after. In principle, damaging the visual cortex should not do anything to the maze-running ability of that blind rat. But the classic experimental finding made decades ago by Karl Lashley of Yerkes Laboratories of Primate Biology and others is that the rat’s performance gets worse, suggesting that the visual cortex in the blind rat was contributing something, although we do not know what it was.­­ All Rights Reserved © 2020

Keyword: Vision; Development of the Brain
Link ID: 27143 - Posted: 03.25.2020

Eric Haseltine A recent bulletin from physicians in the UK described the loss of smell and taste in COVID-19 patients, suggesting that the virus might affect parts of the central nervous system, in addition to its well-known affinity for the respiratory system. Indeed, in an earlier outbreak of coronavirus in China, Hong Kong researcher Dr. K.K. Lau and co-workers found that some patients exhibited convulsions, delirium and restlessness, while Dr. Jun Xu, of the Guangzhou Institute of Respiratory Diseases estimated that 4-5% of all SARS coronavirus patients displayed central nervous system symptoms. Some SARS coronavirus patients have even exhibited marked brain damage on CAT scans. In the latest outbreak of coronavirus, evidence of central nervous system involvement is accumulating, such as a March 21st report by Dr. Asia Filatov of Charles E. Schmidt College of Medicine, that a COVID-19 patient exhibited encephalopathy (brain disease). And recent data from Wuhan, described in the March 12 edition of Neurology Today, indicate that neurological symptoms, such as "altered consciousness," occur in up to one third of COVID-19 cases. But could central nervous system action of COVID-19 directly contribute to the acute respiratory distress associated with the disease? The answer might be “yes” according to recent collaborative research from Drs. Y.C. LI and W.Z. Bai Dr. T. and Hashikawa in Japan. Writing in the Feb 27 edition of the Journal of Medical Virology, Li and colleagues, cite research on coronavirus showing that sometimes SARS-Cov infects brainstem centers that control respiration, making it difficult for infected patients to breathe spontaneously. © 2020 Sussex Publishers, LLC

Keyword: Miscellaneous
Link ID: 27142 - Posted: 03.25.2020

By Erin Garcia de Jesus Myriad microbes dwell on human tongues — and scientists have now gotten a glimpse at the neighborhoods that bacteria build for themselves. Bacteria grow in thick films, with different types of microbes clustered in patches around individual cells on the tongue’s surface, researchers report online March 24 in Cell Reports. This pattern suggests individual bacterial cells first attach to the tongue cell’s surface and then grow in layers as they form larger clusters — creating miniature environments the different species need to thrive. “It’s amazing, the complexity of the community that they build right there on your tongue,” says Jessica Mark Welch, a microbiologist at the Marine Biological Laboratory in Woods Hole, Mass. Methods to identify microbial communities typically hunt for genetic fingerprints from various types of bacteria (SN: 11/05/09). The techniques can reveal what lives on the tongue, but not how the bacterial community is organized in space, Mark Welch says. So she and her colleagues had people scrape the top of their tongues with plastic scrapers. Then the team tagged various types of bacteria in the tongue gunk with differently colored fluorescent markers to see how the microbial community was structured. Bacterial cells, largely grouped by type in a thick, densely packed biofilm, covered each tongue surface cell. While the overall patchwork appearance of the microbial community was consistent among cells from different samples and people, the specific composition of bacteria varied, Mark Welch says. © Society for Science & the Public 2000–2020.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 27141 - Posted: 03.25.2020

By Joshua Sokol The city of Minamata, Japan, is dotted with monuments commemorating victims of an industrial mass poisoning decades ago. High in the hills, a small stone memorial honors other deaths—of cats sacrificed in secret to science. Now, after restudying the remains of one of those cats, a team of scientists is arguing, controversially, that the long-standing explanation for the tragedy is wrong. No one questions the root cause of the disaster, which at minimum poisoned more than 2000 people: mercury in a chemical factory’s wastewater that was dumped into Minamata Bay and taken up by seafood eaten by fishermen and their families. At first, the chemical form of the mercury, which ultimately killed many of its victims and left many babies with severe neurological disorders, was unknown. But in 1968, the Japanese government blamed methylmercury, a common byproduct of mercury pollution. Many studies supported that conclusion, finding methylmercury spikes in shellfish, bay sludge, and even hundreds of umbilical cords from babies delivered during the time. But methylmercury is not the culprit, says Ingrid Pickering, an x-ray spectroscopist at the University of Saskatchewan. “Our work is indicating that it’s something else”: an unusual mercury compound that may say little about the broader threat of mercury pollution. Minamata has long been a vivid case study of mercury’s dangers. The metal is toxic on its own, but it becomes far more dangerous when bacteria in natural environments convert it into methylmercury, an organic compound, readily absorbed by living tissues, that can be concentrated and passed up food chains. Since the 1990s, scientists have argued that the Chisso chemical factory in Minamata produced methylmercury and dumped it directly into the bay. © 2020 American Association for the Advancement of Science.

Keyword: Neurotoxins
Link ID: 27140 - Posted: 03.25.2020

Jordana Cepelewicz In the 1990s, an army of clones invaded Germany. Within a decade, they had spread to Italy, Croatia, Slovakia, Hungary, Sweden, France, Japan and Madagascar — wreaking havoc in rivers and lakes, rice paddies and swamps; in waters warm and cold, acidic and basic. The culprits: six-inch-long, lobster-like creatures called marbled crayfish. Scientists suspect that sometime around 1995, a genetic mutation allowed a pet crayfish to reproduce asexually, giving rise to a new, all-female species that could make clones of itself from its unfertilized eggs. Deliberately or accidentally, some of these mutants were released from aquariums into the wild, where they rapidly multiplied into the millions, threatening native waterways species and ecosystems. But their success is strange. “All marbled crayfish which exist today derive from a single animal,” said Günter Vogt, a biologist at Heidelberg University. “They are all genetically identical.” Ordinarily, the absence of genetic diversity makes a population exceedingly vulnerable to the vagaries of its environment. Yet the marbled crayfish have managed to thrive around the globe. A closer look reveals that the crayfishes’ uniformity is only genome-deep. According to studies conducted by Vogt and others in the mid-2000s, these aquatic clones actually vary quite a bit in their color, size, behavior and longevity. Which means that something other than their genes is inspiring that diversity. Common sense tells us that if it’s not nature, it’s nurture: environmental influences that interact with an animal’s genome to generate different outcomes for various traits. But that’s not the whole story. New research on crayfish and scores of other organisms is revealing an important role for a third, often-overlooked source of variation and diversity — a surprising foundation for what makes us unique that begins in the first days of an embryo’s development: random, intrinsic noise. All Rights Reserved © 2020

Keyword: Development of the Brain; Genes & Behavior
Link ID: 27139 - Posted: 03.24.2020

By Eva Frederick They’re the undertakers of the bee world: a class of workers that scours hives for dead comrades, finding them in the dark in as little as 30 minutes, despite the fact that the deceased haven’t begun to give off the typical odors of decay. A new study may reveal how they do it. “The task of undertaking is fascinating” and the new work is “pretty cool,” says Jenny Jandt, a behavioral ecologist at the University of Otago, Dunedin, who was not involved with the study. Wen Ping, an ecologist at the Chinese Academy of Sciences’s Xishuangbanna Tropical Botanical Garden, wondered whether a specific type of scent molecule might help undertaker bees find their fallen hive mates. Ants, bees, and other insects are covered in compounds called cuticular hydrocarbons (CHCs), which compose part of the waxy coating on their cuticles (the shiny parts of their exoskeletons) and help prevent them from drying out. While the insects are alive, these molecules are continually released into the air and are used to recognize fellow hive members. Wen speculated that less of the pheromones were being released into the air after a bee died and its body temperature decreased. When he used chemical methods of detecting gases to test this hypothesis, he confirmed that cooled dead bees were indeed emitting fewer volatile CHCs than living bees. © 2020 American Association for the Advancement of Science.

Keyword: Chemical Senses (Smell & Taste); Animal Communication
Link ID: 27138 - Posted: 03.24.2020

By Matt McGrath Environment correspondent A new study that looks at lifespan in wild mammals shows that females live substantially longer than males. The research finds that, on average, females live 18.6% longer than males from the same species. This is much larger than the well-studied difference between men and women, which is around 8%. The scientists say the differences in these other mammals are due to a combination of sex-specific traits and local environmental factors. In every human population, women live longer than men, so much so that nine out of 10 people who live to be 110 years old are female. This pattern, researchers say, has been consistent since the first accurate birth records became available in the 18th Century. While the same assumption has been held about animal species, large-scale data on mammals in the wild has been lacking, Now, an international team of researchers has examined age-specific mortality estimates for a widely diverse group of 101 species. In 60% of the analysed populations, the scientists found that females outlived the males - on average, they had a lifespan that's 18.6% longer than males. "The magnitude of lifespan and ageing across species is probably an interaction between environmental conditions and sex-specific genetic variations," said lead author Dr Jean-Francois Lemaître, from the University of Lyon, France. He gives the example of bighorn sheep for which the researchers had access to good data on different populations. Where natural resources were consistently available there was little difference in lifespan. However, in one location where winters were particularly severe, the males lived much shorter lives. © 2020 BBC.

Keyword: Sexual Behavior; Evolution
Link ID: 27137 - Posted: 03.24.2020