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Bruce Bower NEW ORLEANS — A relatively small brain can pack a big evolutionary punch. Consider Homo naledi, a famously puzzling fossil species in the human genus. Despite having a brain only slightly larger than a chimpanzee’s, H. naledi displays key humanlike neural features, two anthropologists reported April 20 at the annual meeting of the American Association of Physical Anthropologists. Those brain characteristics include a region corresponding to Broca’s area, which spans parts of the right and left sides of the brain in present-day people. The left side is typically involved in speech and language. “It looks like Homo naledi’s brain evolved a huge amount of shape change that supported social emotions and advanced communication of some type,” said Shawn Hurst of Indiana University Bloomington, who presented the new findings. “We can’t say for sure whether that included language.” Frontal brain locations near Broca’s area contribute to social emotions such as empathy, pride and shame. As interactions within groups became more complex in ancient Homo species, neural capacities for experiencing social emotions and communicating verbally blossomed, Hurst suspects. Scientists don’t know how long ago H. naledi inhabited Africa’s southern tip. If H. naledi lived 2 million or even 900,000 years ago, as some researchers have suggested (SN: 8/6/16, p. 12), humanlike brains with a language-related area would be shocking. A capacity for language is thought to have emerged in Homo over the last few hundred thousand years at most. |© Society for Science & the Public 2000 - 2017.
Link ID: 23541 - Posted: 04.26.2017
By Debra W. Soh The reasons behind why people are gay, straight, or bisexual have long been a source of public fascination. Indeed, research on the topic of sexual orientation offers a powerful window into understanding human sexuality. The Archives of Sexual Behavior recently published a special edition devoted to research in this area, titled “The Puzzle of Sexual Orientation.” One study, conducted by scientists at the University of Lethbridge in Alberta, Canada, offers compelling, cross-cultural evidence that common genetic factors underlie same-sex, sexual preference in men. In southern Mexico, individuals who are biologically male and sexually attracted to men are known as muxes. They are recognized as a third gender: Muxe nguiiu tend to be masculine in their appearance and behavior, while muxe gunaa are feminine. In Western cultures, they would be considered gay men and transgender women, respectively. Several correlates of male androphilia — biological males who are sexually attracted to men — have been shown across different cultures, which is suggestive of a common biological foundation among them. For example, the fraternal birth order effect—the phenomenon whereby male androphilia is predicted by having a higher number of biological older brothers—is evident in both Western and Samoan cultures. Interestingly, in Western society, homosexual men, compared with heterosexual men, tend to recall higher levels of separation anxiety — the distress resulting from being separated from major attachment figures, like one’s primary caregiver or close family members. Research in Samoa has similarly demonstrated that third-gender fa’afafine—individuals who are feminine in appearance, biologically male, and attracted to men—also recall greater childhood separation anxiety when compared with heterosexual Samoan men. Thus, if a similar pattern regarding separation anxiety were to be found in a third, disparate culture—in the case, the Istmo region of Oaxaca, Mexico—it would add to the evidence that male androphilia has biological underpinnings. © 2017 Scientific American
By CATHERINE SAINT LOUIS In her 30s, Sophie Marat, now 42, used to record herself reading poetry aloud, then play it back to hear if she sounded like a woman. Ms. Marat, who is transgender, had spent years trying to remake her voice in private by speaking in a higher pitch but ultimately felt that her efforts were hopeless. “I was feeling like changing my voice to match my gender identity was almost impossible,” she said. “It was terrible.” Ms. Marat’s transition from male to female has been a gradual evolution. She had come out to friends and family back home in Mexico, then began to wear skirts to work as a software engineer in Manhattan. Still, her confidence would falter with everyday tasks like ordering takeout. “It was really painful to speak on the phone,” she said, “because they would reply, ‘O.K., sir.’” That was before she started her weekly sessions with a voice therapist at New York University’s speech-language-hearing clinic, one of a growing number of programs that cater to transgender clients seeking to retrain their voices. Just as some transgender women and men choose to take hormones or have surgery, or choose neither, some seek to feminize or masculinize their voices. Many say they want a voice that matches their appearance or that the change allows them to escape unwanted attention. There’s also a growing recognition among health professionals who have transgender patients that altering one’s voice can improve quality of life and reduce distress. After eight months, she had raised her pitch, worked on moving her resonance forward and finishing phrases with an open ending, rather than bluntly. “This isn’t just a sidebar,” said Sandy Hirsch, a Seattle-based speech language pathologist who was a co-author of the pioneering textbook on transgender voice and communication therapy. “It’s an integral part of care for transgender people as they transition.” © 2017 The New York Times Company
By Knvul Sheikh Scientists have known for decades that what we eat can change the balance of microbes in our digestive tracts. Choosing between a BLT sandwich or a yogurt parfait for lunch can increase the populations of some types of bacteria and diminish others—and as their relative numbers change they secrete different substances, activate different genes and absorb different nutrients. And those food choices are probably a two-way street. Gut microbes have also been shown to influence diet and behavior as well as anxiety, depression, hypertension and a variety of other conditions. But exactly how these trillions of tiny guests—collectively called the microbiome—influence our decisions on which foods to stuff into our mouths has been a mystery. Now neuroscientists have found specific types of gut flora help a host animal detect which nutrients are missing in food, and then finely titrate how much of those nutrients the host really needs to eat. “What the bacteria do for appetite is kind of like optimizing how long a car can run without needing to add more petrol to the tank,” says senior author Carlos Ribeiro, who studies the eating behaviors of Drosophila melanogaster, a type of fruit fly, at Champalimaud Center for the Unknown in Lisbon. In a paper published Tuesday in PLoS Biology Ribeiro and his team demonstrated how the microbiome influences drosophila’s nutritional decisions. First, they fed one group of flies a sucrose solution containing all the necessary amino acids. Another group got a mix that had some of the amino acids needed to make protein but lacked essential amino acids that the host cannot synthesize by itself. For a third group of flies, the scientists removed essential amino acids from the food one by one to determine which was being detected by the microbiome. © 2017 Scientific American,
Link ID: 23538 - Posted: 04.26.2017
By Thomas MacMillan “Time” is the most common noun in the English language, Dean Buonomano tells us on the first page of his new book, Your Brain Is a Time Machine: The Neuroscience and Physics of Time. But our despite fixation with time, and its obvious centrality in our lives, we still struggle to fully understand it. From a psychology perspective, for instance, time seems to flow by, sometimes slowly — like when we’re stuck in line at the DMV — and sometimes quickly — like when we’re lost in an engrossing novel. But from a physics perspective, time may be simply another dimension in the universe, like length, height, or width. Buonomano, a professor of neuroscience at UCLA, lays out the latest, best theories about how we understand time, illuminating a fundamental aspect of being human. The human brain, he writes, is a time machine that allows us to mentally travel backward and forward, to plan for the future and agonizingly regret that past like no other animal. And, he argues, our brains are time machines like clocks are time machines: constantly tracking the passage of time, whether it’s circadian rhythms that tell us when to go to sleep, or microsecond calculations that allow us to the hear the difference between “They gave her cat-food” and “They gave her cat food.” In an interview with Science of Us, Buonomano spoke about planning for the future as a basic human activity, the limits of be-here-now mindfulness, and the inherent incompatibility between physicists’ and neuroscientists’ understanding of the nature of time. I finished reading your book late last night and went to bed sort of planning our interview today, and then woke up at about 3:30 a.m. ready to do the interview, with my head full of insistent thoughts about questions that I should ask you. So was that my brain being a — maybe malfunctioning — time machine? I think this is consistent with the notion that the brain is an organ that’s future-oriented. As far as survival goes, the evolutionary value of the brain is to act in the present to ensure survival in the future, whether survival is figuring out a good place to get food, or doing an interview, I suppose. ! © Invalid Date, New York Media LLC
By Daniel Barron Earlier this month, JAMA Psychiatry published a land-breaking editorial. A group of psychiatrists led by David Ross described how and why post-traumatic stress disorder (PTSD) should be clinically evaluated from a neuroscience framework. The fact that this editorial was published in one of psychiatry’s leading journals is no small feat. Psychiatry houses a large and powerful contingency that argues neuroscience has little clinical relevance. The relevance of neuroscience to psychiatry was the subject of a recent Op-Ed debate in the New York Times: “There’s Such a Thing as Too Much Neuroscience” was rebutted with “More Neuroscience, Not Less.” This specific debate—and the dense politics as a whole—exists because competing frameworks are vying for competing funding, a conflict that pre-dates Freud’s departure from neurology. That the relevance of neuroscience to psychiatry is still questioned is blatantly outlandish: what organ do psychiatrists treat if not the brain? And what framework could possibly be more relevant than neuroscience to understanding brain dysfunction? In his editorial, Ross tactfully presented his case for neuroscience, describing the obvious choice for a clinical framework as one “perspective,” making a delicate intellectual curtsey while supporting his case with data. Ross discussed five “key neuroscience themes” (read: lines of evidence from burgeoning sub-fields) relevant to understanding and treating PTSD: fear conditioning, dysregulated circuits, memory reconsolidation, and epigenetic and genetic considerations. Each theme accounts for the diverse biological, psychological and social factors involved in PTSD—which is to say, these factors all have some affect on the brain mechanisms. Most importantly, Ross describes how a mechanistic approach allows clinicians to trace the specific causes of PTSD to specific treatments that can target those causes. © 2017 Scientific American,
By NICHOLAS BAKALAR Drinking sugary beverages is associated with markers of accelerated aging and early signs of Alzheimer’s disease, a new study reports. Researchers used data on more than 4,000 people over 30, examining their brains with M.R.I. and measuring memory with psychological tests. All completed well-validated food frequency questionnaires. Sugary beverage intake is an indirect measure of how much sugar we get in our diets, which is difficult to measure precisely. The authors defined “sugary beverage” to include sodas as well as fruit juices, which may contain added sugars. The study, in Alzheimer’s & Dementia, found that on average, the more sugary drinks consumed, the lower the total brain volume and the lower the scores on memory tests. Brain shrinkage is tied to an increased risk of Alzheimer’s disease. Compared with those who drank no sugary drinks, those who drank one or two a day had a reduced brain volume equivalent to 1.6 years of normal aging, and lower memory scores equivalent to 5.8 years of aging. Those who drank more than two had decreased brain volume equivalent to two years of normal aging and lower memory scores by the equivalent of 11 years. The researchers controlled for diabetes, blood pressure, cholesterol, smoking and many other health and behavioral characteristics. “Although we can’t prove cause and effect, these data suggest that we should be cautious about drinking sugary beverages,” said the lead author, Matthew P. Pase, a senior research fellow at Boston University. “They’re empty calories that contribute to weight gain and metabolic disease.” © 2017 The New York Times Company
By Virginia Morell Humpback whales are known for their operatic songs that carry across the seas. Their calves, however, whisper, uttering soft squeaks and grunts to their mothers (which you can hear above). Now, a new study suggests that loud calf voices can also attract some unwanted visitors: male humpbacks, who might separate the pair by trying to mate with the mother, and killer whales, who dine on young humpbacks. To record their sounds, scientists placed temporary tagging devices on eight humpback whale mothers and calves in the Exmouth Gulf off Western Australia, where the young whales spend months suckling to gain enough weight for their annual migrations to the Antarctic or Arctic. After listening to the recordings, scientists say the calves’ careful whispers are not cries for food, as previously thought. Instead, they may help them stay in close contact with their mothers when swimming. And, say researchers, writing today in Functional Ecology, the low decibel sounds help keep would-be predators away from the “nursery.” © 2017 American Association for the Advancement of Science
Keyword: Animal Communication
Link ID: 23534 - Posted: 04.26.2017
By NICK WINGFIELD SEATTLE — Zoran Popović knows a thing or two about video games. A computer science professor at the University of Washington, Dr. Popović has worked on software algorithms that make computer-controlled characters move realistically in games like the science-fiction shooter “Destiny.” But while those games are entertainment designed to grab players by their adrenal glands, Dr. Popović’s latest creation asks players to trace lines over fuzzy images with a computer mouse. It has a slow pace with dreamy music that sounds like the ambient soundtrack inside a New Age bookstore. The point? To advance neuroscience. Since November, thousands of people have played the game, “Mozak,” which uses common tricks of the medium — points, leveling up and leader boards that publicly rank the performance of players — to crowdsource the creation of three-dimensional models of neurons. The Center for Game Science, a group at the University of Washington that Dr. Popović oversees, developed the game in collaboration with the Allen Institute for Brain Science, a nonprofit research organization founded by Paul Allen, the billionaire co-founder of Microsoft, that is seeking a better understanding of the brain. Dr. Popović had previously received wide attention in the scientific community for a puzzle game called “Foldit,” released nearly a decade ago, that harnesses the skills of players to solve riddles about the structure of proteins. The Allen Institute’s goal of cataloging the structure of neurons, the cells that transmit information throughout the nervous system, could one day help researchers understand the roots of neurodegenerative diseases like Alzheimer’s and Parkinson’s and their treatment. Neurons come in devilishly complex shapes and staggering quantities — about 100 million and 87 billion in mouse and human brains, both of which players can work on in Mozak. © 2017 The New York Times Company
Keyword: Brain imaging
Link ID: 23533 - Posted: 04.25.2017
Doing moderate exercise several times a week is the best way to keep the mind sharp if you're over 50, research suggests. Thinking and memory skills were most improved when people exercised the heart and muscles on a regular basis, a review of 39 studies found. This remained true in those who already showed signs of cognitive decline. Taking up exercise at any age was worthwhile for the mind and body, the Australian researchers said. Exercises such as T'ai Chi were recommended for people over the age of 50 who couldn't manage other more challenging forms of exercise, the study in the British Journal of Sports Medicine said. Physical activity has long been known to reduce the risk of a number of diseases, including type-2 diabetes and some cancers, and it is thought to play a role in warding off the brain's natural decline as we enter middle age. The theory is that through exercise the brain receives a greater supply of blood, oxygen and nutrients that boost its health as well as a growth hormone that helps the formation of new neurons and connections. In this analysis of previous studies, researchers from the University of Canberra looked at the effects of at least four weeks of structured physical exercise on the brain function of adults. In a variety of brain tests, they found evidence of aerobic exercise improving cognitive abilities, such as thinking, reading, learning and reasoning, while muscle training - for example, using weights - had a significant effect on memory and the brain's ability to plan and organise, the so-called executive functions. Joe Northey, study author and researcher from the Research Institute for Sport and Exercise at Canberra, said the findings were convincing enough to enable both types of exercise to be prescribed to improve brain health in the over-50s. © 2017 BBC.
Link ID: 23532 - Posted: 04.25.2017
By Lauren Gravitz, Connor was diagnosed with autism early — when he was just 18 months old. His condition was already obvious by then. “He was lining things up, switching lights on and off, on and off,” says his mother, Melissa. He was bright, but he didn’t speak much until age 3, and he was easily frustrated. Once he started school, he couldn’t sit still in class, called out answers without raising his hand and got visibly upset when he couldn’t master a math concept or a handwriting task quickly enough. “One time, he rolled himself up into the carpet like a burrito and wouldn’t come out until I got there,” Melissa recalls. (All families in this story are identified by first name only, to protect their privacy.) Connor was prescribed his first psychiatric drug, methylphenidate (Ritalin), at age 6. That didn’t last long, but when he was 7, his parents tried again. A psychiatrist suggested a low dose of amphetamine and dextroamphetamine (Adderall), a stimulant commonly used to treat attention deficit hyperactivity disorder (ADHD). The drug seemed to improve his time at school: He was able to sit still for longer periods of time and focus on what his teachers were saying. His chicken-scratch handwriting became legible. Then, it became neat. Then perfect. And then it became something Connor began to obsess over. “We were told that these are the gives and takes; if it’s helping him enough to get through school, you have to decide if it’s worth it,” Melissa says. It was worth it — for a while. © 2017 Scientific American
Link ID: 23531 - Posted: 04.25.2017
By Clare Wilson Could fasting boost your brainpower? A stomach hormone that stimulates appetite seems to promote the growth of new brain cells and protect them from the effects of ageing – and may explain why some people say that fasting makes them feel mentally sharper. When ghrelin was first discovered, it became known as the hunger hormone. It is made by the stomach when it gets empty, and whenever we go a few hours without food its levels rise in our blood. But there is also evidence that ghrelin can enhance cognition. Animals that have reduced-calorie diets have better mental abilities, and ghrelin might be part of the reason why. Injecting the hormone into mice improves their performance in learning and memory tests, and seems to boost the number of neuron connections in their brains. Now Jeffrey Davies at Swansea University, UK, and his team have found further evidence that ghrelin can stimulate brain cells to divide and multiply, a process called neurogenesis. When they added the hormone to mouse brain cells grown in a dish, it switched on a gene known to trigger neurogenesis, called fibroblast growth factor. If the same effect happens in animals, this could be how ghrelin exerts its effects on memory, says Davies, whose work was presented at the British Neuroscience Association conference this month. © Copyright Reed Business Information Ltd.
Beau Lotto When you open your eyes, do you see the world as it really is? Do we see reality? Humans have been asking themselves this question for thousands of years. From the shadows on the wall of Plato’s cave in “The Republic” to Morpheus offering Neo the red pill or the blue bill in “The Matrix,” the notion that what we see might not be what is truly there has troubled and tantalized us. In the eighteenth century, the philosopher Immanuel Kant argued that we can never have access to the Ding an sich, the unfiltered “thing-in-itself ” of objective reality. Great minds of history have taken up this perplexing question again and again. They all had theories, but now neuroscience has an answer. The answer is that we don’t see reality. The world exists. It’s just that we don’t see it. We do not experience the world as it is because our brain didn’t evolve to do so. It’s a paradox of sorts: Your brain gives you the impression that your perceptions are objectively real, yet the sensory processes that make perception possible actually separate you from ever accessing that reality directly. Our five senses are like a keyboard to a computer — they provide the means for information from the world to get in, but they have very little to do with what is then experienced in perception. They are in essence just mechanical media, and so play only a limited role in what we perceive. In fact, in terms of the sheer number of neural connections, just 10 percent of the information our brains use to see comes from our eyes. The rest comes from other parts of our brains, and this other 90 percent is in large part what this book is about. Perception derives not just from our five senses but from our brain’s seemingly infinitely sophisticated network that makes sense of all the incoming information. © 2017 The Associated Press.
Link ID: 23529 - Posted: 04.25.2017
By Diana Kwon Most of us will laugh at a good joke, but we also laugh when we are not actually amused. Fake chuckles are common in social situations—such as during an important interview or a promising first date. “Laughter is really interesting because we observe it across all human cultures and in other species,” says Carolyn McGettigan, a cognitive neuroscientist at Royal Holloway, University of London. “It's an incredibly important social signal.” In a 2013 study, McGettigan, then a postdoctoral researcher at University College London, and her colleagues scanned the brains of 21 participants while they passively listened to clips of laughter elicited by funny YouTube videos or produced on command (with instructions to sound as natural as possible). Subjects whose medial prefrontal cortex “lit up” more when hearing the posed laughter were better at detecting whether laughs were genuine or not in a subsequent test. (This brain region is involved in understanding the viewpoint of others.) “If you hear a laugh that seems ambiguous in terms of what the person means,” McGettigan explains, “it makes sense that you're going to try to work out why this person sounds like this.” In a follow-up study in 2016, McGettigan and her colleagues recruited a fresh set of participants to rate the laugh tracks on various qualities, such as authenticity and positivity. They compared these findings with the original brain data and found that the activity in the medial prefrontal cortex was negatively correlated with the genuineness of the laughs. Their analyses also revealed that both types of laughter engaged the auditory cortices, although activity in these brain regions increased as the laughs became happier, more energetic and more authentic. © 2017 Scientific American,
Link ID: 23528 - Posted: 04.24.2017
Austin Frakt The burden of substance abuse disorders can fall heavily on the families and friends of those who battle addictions. But society also pays a great deal through increased crime. Treatment programs can reduce those costs. For at least two decades, we’ve known substance use and crime go hand in hand. More than half of violent offenders and one-third of property offenders say they committed crimes while under the influence of alcohol or drugs. Researchers with the Centers for Disease Control and Prevention recently estimated that prescription opioid abuse, dependence and overdoses cost the public sector $23 billion a year, with a third of that attributable to crime. An additional $55 billion per year reflects private-sector costs attributable to productivity losses and health care expenses. About 80,000 Americans are incarcerated for opioid-related crimes alone. The total annual economic burden of all substance use disorders — not just those involving opioids — is in the hundreds of billions of dollars. In an editorial accompanying the C.D.C. researchers’ study, Harold Pollack, co-director of the University of Chicago Crime Lab, wrote that opioid-associated crime, like all crime, extracts an even larger toll when you consider its impact on families and communities. “The most important reason to support treatment is to improve the well-being and social function of people with addiction disorders,” Mr. Pollack said. But there are other social benefits. When the criminally active get help for this, “the economic value of crime reduction largely or totally offsets the costs of treatment,” he added. Relative to the costs of crime alone, treatment for substance use disorders is a good deal. Even though a typical burglary may result in a few thousand dollars of tangible losses, researchers have estimated that people are willing to pay 10 times that amount to avoid that loss and 100 times more to avoid armed robbery. This reflects the fact that crime exacts a large psychological toll — the threat or climate of it is far more costly than the crimes themselves. © 2017 The New York Times Company
Keyword: Drug Abuse
Link ID: 23527 - Posted: 04.24.2017
Jonathan Rée Beau Lotto is a gung-ho neuroscientist. “[The] great minds of history,” he says, “had theories, but now neuroscience has an answer.” The latest research has, it seems, established that everything you experience “takes place in the brain” and that “you never, ever see reality!” (Lotto loves his italics and exclamation marks.) Your brain may be beautiful, but “what makes it beautiful is that it is delusional” and you should therefore get shot of your inhibitions and summon the courage to “deviate!” Perhaps we should back up a little. Early in the book, Lotto mentions a French scientist called Michel Chevreul who started working at the Gobelins textile factory in Paris in the 1820s. Chevreul had to deal with complaints about coloured yarns that seemed to fade after being woven into tapestries, and his patient chemical analyses did not get him anywhere. But then he shifted his attention from the science of dyestuffs to the psychology of perception, and he was on the way to a solution: colours, he discovered, change their appearance when looked at side by side. I needed respite from Lotto’s exclamation marks so I spent an afternoon in the British Library looking through a gorgeous old volume in which Chevreul expounded his “law of the simultaneous contrast of colours”. Chevreul began by showing how a black line has drastic effects on the appearance of adjacent colours, and how a red patch makes its surroundings look green. He then discussed the difference between colours in an object and colours in a painting, and offered suggestions about the design of picture frames and the use of colour in theatre; and he finished with wonderful planting plans for beds of multicoloured crocuses and dahlias. The book is itself an exuberant work of art, with tinted pages and fold-out arrays of coloured dots looking like prototypes of the spot paintings of Damien Hirst.
Link ID: 23526 - Posted: 04.24.2017
By Cormac McCarthy I call it the Kekulé Problem because among the myriad instances of scientific problems solved in the sleep of the inquirer Kekulé’s is probably the best known. He was trying to arrive at the configuration of the benzene molecule and not making much progress when he fell asleep in front of the fire and had his famous dream of a snake coiled in a hoop with its tail in its mouth—the ouroboros of mythology—and woke exclaiming to himself: “It’s a ring. The molecule is in the form of a ring.” Well. The problem of course—not Kekulé’s but ours—is that since the unconscious understands language perfectly well or it would not understand the problem in the first place, why doesnt it simply answer Kekulé’s question with something like: “Kekulé, it’s a bloody ring.” To which our scientist might respond: “Okay. Got it. Thanks.” Why the snake? That is, why is the unconscious so loathe to speak to us? Why the images, metaphors, pictures? Why the dreams, for that matter. A logical place to begin would be to define what the unconscious is in the first place. To do this we have to set aside the jargon of modern psychology and get back to biology. The unconscious is a biological system before it is anything else. To put it as pithily as possibly—and as accurately—the unconscious is a machine for operating an animal. All animals have an unconscious. If they didnt they would be plants. We may sometimes credit ours with duties it doesnt actually perform. Systems at a certain level of necessity may require their own mechanics of governance. Breathing, for instance, is not controlled by the unconscious but by the pons and the medulla oblongata, two systems located in the brainstem. Except of course in the case of cetaceans, who have to breathe when they come up for air. An autonomous system wouldnt work here. The first dolphin anesthetized on an operating table simply died. (How do they sleep? With half of their brain alternately.) But the duties of the unconscious are beyond counting. Everything from scratching an itch to solving math problems. © 2017 NautilusThink Inc,
By Chris Baraniuk Bat-detecting drones could help us find out what the animals get up to when flying. Ultrasonic detectors on drones in the air and on the water are listening in on bat calls, in the hope of discovering more about the mammals’ lives beyond the reach of ground-based monitoring devices. Drone-builder Tom Moore and bat enthusiast Tom August have developed three different drones to listen for bat calls while patrolling a pre-planned route. Since launching the scheme, known as Project Erebus, in 2014, they have experimented with two flying drones and one motorised boat, all equipped with ultrasonic detectors. The pair’s latest tests have demonstrated the detection capabilities of the two airborne drone models: a quadcopter and a fixed-wing drone. Last month, the quadcopter successfully followed a predetermined course and picked up simulated bat calls produced by an ultrasonic transmitter. The bat signal Moore says one of the major hurdles is detecting the call of bats over the noise of the drones’ propellers, which emit loud ultrasonic frequencies. They overcame this with the quadcopter by dangling the detector underneath the body and rotors of the drone. This is not such a problem for the water-based drone. Last year, Moore and August tested a remote-controlled boat in Oxfordshire, UK, and picked up bat calls thought to belong to common pipistrelle and Daubenton’s bats. The different species often emit different ultrasonic frequencies. © Copyright Reed Business Information Ltd.
By Meredith Knight A complex cascade of biochemical signals determines what we eat, when we eat and how much we eat. Our digestive tracts and fat cells are known to secrete hormones that drive our hunger levels and our sense of satisfaction after eating. Now a new player has come to the table, our bones. A paper published this March in Nature shows bone cells secrete a hormone called lipocalin 2—and it has a surprising effect in mouse experiments of reducing appetite and stabilizing blood sugar independently of other hormones Stavroula Kousteni, a physiologist at Columbia University College of Physicians and Surgeons, and her colleagues showed 90 percent of the hormone lipocalin 2 was produced by osteoblasts, bone cells that create the chemicals necessary to build new bone. Because of its chemical structure scientists previously thought fat cells made the hormone. Lipocalin 2 is released after eating and reaches peak levels about an hour after a meal. When researchers genetically designed mice with defective lipocalin 2 genes in bone, the mice had 20 percent more body fat than mice that had the defective gene inserted into fatty tissue. The animals also ate 16 percent more chow. When mice with the broken gene were injected with lipocalin 2, their feeding behavior returned to normal. Injections of the hormone even reduced eating and improved blood sugar and insulin regulation in healthy mice. “In general, we found we could improve their metabolic phenotype,” Kousteni says. © 2017 Scientific American
Link ID: 23523 - Posted: 04.22.2017
Paula Span “During the past four weeks, have you been tired? Been exhausted? Had difficulty getting motivated to do anything at all?” These questions — which a substantial chunk of the population probably could answer in the affirmative — appeared on a questionnaire used in a major European study published recently in The New England Journal of Medicine. The authors were researching the effectiveness of a drug that is widely, if controversially, used to treat older adults with subclinical hypothyroidism, better known as a slightly underactive thyroid. So many Americans take that medication — levothyroxine (brand name Synthroid) — that it topped the list of prescription drugs dispensed in the United States in 2015, according to the research firm QuintilesIMS Institute. With 121 million prescriptions annually, levothyroxine outpaced statins, blood pressure meds — and everything else. A Johns Hopkins survey published last year found that more than 15 percent of older Americans were taking it. So you’d think these study results would come as shocking news: The European team reported that in older people with mild hypothyroidism, the drug had no significant effect on symptoms. At all. Instead, the results bolstered what a number of geriatricians and endocrinologists have suspected for years. “It’s a strong signal that this is an overused medication,” said Dr. Juan Brito, an endocrinologist at the Mayo Clinic. “Some people really need this medicine, but not the vast majority of people who are taking it.” © 2017 The New York Times Company
Keyword: Hormones & Behavior
Link ID: 23522 - Posted: 04.22.2017