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By Mitch Leslie If papers published in the past 6 months are right, a single number is enough to show whether people are likely to suffer a premature heart attack, land first authorship on published papers, become dependent on alcohol, or put on fat around the middle. That magic number is the ratio between the lengths of the second and fourth fingers, known as the 2D:4D ratio. It tends to be lower in men—meaning their fourth fingers tend to be longer than their second—than in women. Researchers who believe in its predictive power say it reflects a fetus's exposure to testosterone and other hormones that guide development, including that of the brain. The idea that the lengths of human fingers reveal so much stems from the work of evolutionary biologist John Manning, now at Swansea University in the United Kingdom. But the field he inspired has ballooned beyond what he could have imagined. More than 1400 papers in just over 20 years have linked the finger ratio to attributes such as personality, cognitive abilities, and sexual orientation as well as to risk of illnesses such as cardiovascular disease, cancer, and amyotrophic lateral sclerosis. Researchers have even tried to use ratios gleaned from stenciled handprints on cave walls to determine whether the artists behind ancient paintings were men or women. But the notion has also riled plenty of critics, who argue that researchers who rely on the 2D:4D comparison have been seduced by a simplistic, faulty measure. Some doubters contend that the difference in ratios between the sexes is an illusion resulting from men's larger hands or that the measure itself is statistically problematic. "I'm skeptical about every single finding involving that ratio," says physiologist and biostatistician Douglas Curran-Everett of National Jewish Health in Denver. © 2019 American Association for the Advancement of Science

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 26311 - Posted: 06.07.2019

By Aiyana Bailin To my dismay, Simon Baron-Cohen’s recent article “The Concept of Neurodiversity is Dividing the Autism Community” perpetuates a common misunderstanding of the neurodiversity movement: that it views autism as a difference but not a disability. Baron-Cohen presents the issue as one of opposing sides: the medical model, which sees autism as a set of symptoms and deficits to be cured or treated, and the neurodiversity model, which he believes ignores any disabling aspects of autism. Unfortunately, this confuses the neurodiversity movement with the social model of disability, and it is an incomplete understanding of the social model at that. Before I go into details, let me summarize what the neurodiversity movement does believe: Autism and other neurological variations (learning disabilities, ADHD, etc.) may be disabilities, but they are not flaws. People with neurological differences are not broken or incomplete versions of normal people. Disability, no matter how profound, does not diminish personhood. People with atypical brains are fully human, with inalienable human rights, just like everyone else. People with disabilities can live rich, meaningful lives. Neurological variations are a vital part of humanity, as much as variations in size, shape, skin color and personality. None of us has the right (or the wisdom) to try and improve upon our species by deciding which characteristics to keep and which to discard. Every person is valuable. Disability is a complicated thing. Often, it’s defined more by society’s expectations than by individual conditions. Not always, but often. © 2019 Scientific American

Keyword: Autism
Link ID: 26310 - Posted: 06.07.2019

Ian Sample Science editor If the dead-end job, the pokey flat and the endless failings of the neighbours are getting on your wick, then spare a thought for the dog. In research that confirms what many owners will have worked out for themselves, scientists have found that the household pets are not oblivious to their owners’ anxieties, but mirror the amount of stress they feel. The finding comes from a study of cortisol, a stress hormone, which circulates in the blood and leaves its mark in strands of hair. Over time, as the hormone is bound into the growing hair, each shaft becomes a biological record of the stress an individual experiences. After engaging the willing services of 25 border collies, 33 Shetland sheepdogs, and the animals’ female owners, researchers in Sweden found that higher cortisol in human hair was matched by more of the hormone in the dog hair. All of the dogs lived indoors with their owners. “This is the first time we’ve seen a long-term synchronisation in stress levels between members of two different species,” said Lina Roth, an ethologist who led the work at Linköping University in Sweden. “We haven’t seen this between humans and dogs before.” Roth’s team measured concentrations of cortisol in short strands of hair cut close to the skin in the winter and summer of 2017 and 2018. The link between human and dog cortisol held through the seasons, but was higher in dogs in the winter. © 2019 Guardian News & Media Limited

Keyword: Stress
Link ID: 26309 - Posted: 06.07.2019

By Lindsey Bever Doctors had broken the disheartening news to Rachel Palma, explaining that the lesion on her brain was suspected to be a tumor, and her scans suggested that it was cancerous. Palma, a newlywed entering a new chapter in her life, said she was in shock, unwilling to believe it was true. In September, scrubbed-up surgeons in an operating room at Mount Sinai Hospital in New York City opened Palma’s cranium and steeled themselves for a malignant brain tumor, said Jonathan Rasouli, chief neurosurgery resident at the Icahn School of Medicine at Mount Sinai. But instead, Rasouli said, they saw an encapsulated mass resembling a quail egg. “We were all saying, ‘What is this?’ ” Rasouli recalled Thursday in a phone interview with The Washington Post. “It was very shocking. We were scratching our heads, surprised at what it looked like.” The surgeons removed it from Palma’s brain and placed it under a microscope to get a closer look. Then they sliced into it — and found a baby tapeworm. Palma, from Middletown, N.Y., said she had mixed emotions about it. “Of course I was grossed out,” the 42-year-old said Thursday, explaining that no one wants to think there’s a tapeworm growing inside an egg in his or her brain. “But of course, I was also relieved. It meant that no further treatment was necessary.” A scan showing the tapeworm in Rachel Palma's brain. (Mount Sinai Health System) © 1996-2019 The Washington Post

Keyword: Miscellaneous
Link ID: 26308 - Posted: 06.07.2019

By Christopher Rowland A team of researchers inside Pfizer made a startling find in 2015: The company’s blockbuster rheumatoid arthritis therapy Enbrel, a powerful anti-inflammatory drug, appeared to reduce the risk of Alzheimer’s disease by 64 percent. The results were from an analysis of hundreds of thousands of insurance claims. Verifying that the drug would actually have that effect in people would require a costly clinical trial — and after several years of internal discussion, Pfizer opted against further investigation and chose not to make the data public, the company confirmed. Researchers in the company’s division of inflammation and immunology urged Pfizer to conduct a clinical trial on thousands of patients, which they estimated would cost $80 million, to see if the signal contained in the data was real, according to an internal company document obtained by The Washington Post. “Enbrel could potentially safely prevent, treat and slow progression of Alzheimer’s disease,’’ said the document, a PowerPoint slide show that was prepared for review by an internal Pfizer committee in February 2018. The company told The Post that it decided during its three years of internal reviews that Enbrel did not show promise for Alzheimer’s prevention because the drug does not directly reach brain tissue. It deemed the likelihood of a successful clinical trial to be low. A synopsis of its statistical findings prepared for outside publication, it says, did not meet its “rigorous scientific standards.’’ The surprising reasons why drug prices in the U.S. are higher than in the rest of the world © 1996-2019 The Washington Post

Keyword: Alzheimers
Link ID: 26307 - Posted: 06.06.2019

By: Karen Moxon, Ph.D., Ignacio Saez, Ph.D., and Jochen Ditterich, Ph.D. Technology that is sparking an entirely new field of neuroscience will soon let us simply think about something we want our computers to do and watch it instantaneously happen. In fact, some patients with severe neurological injury or disease are already reaping the benefits of initial advances by using their thoughts to signal and control robotic limbs. This brain-computer interface (BCI) idea is spawning a new area of neuroscience called cognitive neuroengineering that holds the promise of improving the quality of life for everyone on the planet in unimaginable ways. But the technology is not yet ready for prime time. There are three basic aspects of BCIs—recording, decoding, and operation, and progress will require refining all three. BCI works because brain activity generates a signal—typically an electrical field—that can be recorded through a dedicated device, which feeds it to a computer whose analysis software (i.e., a decoding algorithm) “translates” the signal to a simple command. This command signal operates a computer or other machine. The resulting operation can be as simple as moving a cursor on a screen, for which the command need contain just X and Y coordinates, or as complex as controlling a robotic arm, which requires information about position, orientation, speed, rotation, and more. Recent work from University of Pittsburgh has shown that subjects with amyotrophic lateral sclerosis (ALS) can control a complex robot arm—having it pick up a pitcher and pour water into a glass—just by thinking about it. The downside is that it is necessary to surgically implant recording microelectrodes intothe brain and that, most importantly, such electrodes are not reliable for more than a few years. © 2019 The Dana Foundation.

Keyword: Robotics; ALS-Lou Gehrig's Disease
Link ID: 26306 - Posted: 06.06.2019

By Neuroskeptic If you delve into the wildest depths of the scientific literature, you will find a trilogy of papers so weird, that they have become legendary. In these articles, spanning a 12 year period, author Jarl Flensmark says that heeled shoes cause mental illness, while flat footwear promotes brain health: Is there an association between the use of heeled footwear and schizophrenia? (2004) Physical activity, eccentric contractions of plantar flexors, and neurogenesis: therapeutic potential of flat shoes in psychiatric and neurological disorders (2009) Flat shoes increase neurogenesis (2016) The abstract of the first paper gives a good sense of Flensmark’s ideas: A selective literature review and synthesis is used to present a hypothesis that finds support in all facts and is contradicted by none. Heeled footwear began to be used more than a 1000 years ago, and led to the occurrence of the first cases of schizophrenia. Industrialization of shoe production increased schizophrenia prevalence. The neurobiological mechanism for this shoe-induced psychosis is said to be that: During walking synchronised stimuli from mechanoreceptors in the lower extremities increase activity in cerebello-thalamo-cortico-cerebellar loops through their action on NMDA-receptors. Using heeled shoes leads to weaker stimulation of the loops. Reduced cortical activity changes dopaminergic function which involves the basal ganglia-thalamo-cortical-nigro-basal ganglia loops. And so it goes on.

Keyword: Schizophrenia
Link ID: 26305 - Posted: 06.06.2019

By Marisa Iati A bill in Alabama awaiting the governor’s signature would require people convicted of certain sex offenses to undergo “chemical castration” as a condition of parole — a requirement meant to keep perpetrators from committing similar crimes. The proposed law, passed by the state legislature, says a judge must order anyone convicted of a sex offense involving a child under the age of 13 to start receiving testosterone-inhibiting medication a month before their release from prison. Most offenders would have to pay for their treatment, which would be administered by the Department of Public Health, until a judge decides the medication is no longer necessary. Under the proposed law, a judge — and not a doctor — would tell the offender about the effects of the treatment. An offender could choose to stop getting the medication and return to prison to serve the remainder of their term. Anyone who stopped receiving the castration treatment without approval would be considered guilty of a Class C felony, punishable under Alabama law by up to 10 years in prison and a fine of up to $15,000. “Chemical castration” is a misnomer, as the process leaves the testes intact, can be reversed and does not prevent a man from reproducing. It does not guarantee a man’s sexual urge will be eliminated. (There’s no consensus on whether chemical castration would be effective for women.) © 1996-2019 The Washington Post

Keyword: Sexual Behavior; Aggression
Link ID: 26304 - Posted: 06.06.2019

Children can keep full visual perception — the ability to process and understand visual information — after brain surgery for severe epilepsy, according to a study funded by the National Eye Institute (NEI), part of the National Institutes of Health. While brain surgery can halt seizures, it carries significant risks, including an impairment in visual perception. However, a new report by Carnegie Mellon University, Pittsburgh, researchers from a study of children who had undergone epilepsy surgery suggests that the lasting effects on visual perception can be minimal, even among children who lost tissue in the brain’s visual centers. Normal visual function requires not just information sent from the eye (sight), but also processing in the brain that allows us to understand and act on that information (perception). Signals from the eye are first processed in the early visual cortex, a region at the back of the brain that is necessary for sight. They then travel through other parts of the cerebral cortex, enabling recognition of patterns, faces, objects, scenes, and written words. In adults, even if their sight is still present, injury or removal of even a small area of the brain’s vision processing centers can lead to dramatic, permanent loss of perception, making them unable to recognize faces, locations, or to read, for example. But in children, who are still developing, this part of the brain appears able to rewire itself, a process known as plasticity. “Although there are studies of the memory and language function of children who have parts of the brain removed surgically for the treatment of epilepsy, there have been rather few studies that examine the impact of the surgery on the visual system of the brain and the resulting perceptual behavior,” said Marlene Behrmann, Ph.D., senior author of the study. “We aimed to close this gap.”

Keyword: Development of the Brain; Vision
Link ID: 26303 - Posted: 06.05.2019

Mara Gordon Kids with obesity face a host of health problems related to their weight, like high blood pressure, diabetes, and joint problems. Research points to another way heavier children and teens are at risk: their own doctors' bias. This prejudice has real health consequences for kids, making families less likely to show up for appointments or get recommended vaccines. I am a family physician at a community health center in Washington, D.C., and many of my young patients have obesity. It's no surprise. Obesity is the most common chronic disease that affects children and teens in the U.S. One third of American kids are overweight or obese. But I often feel totally unprepared to talk about it in a way that puts kids at ease. We have to cram in a physical exam, shots, and parent questions into a 15-minute appointment, and a discussion about a healthy lifestyle sometimes feels like an afterthought. I remember one recent visit with a teenage girl and her mom, tripping over the words I chose. "Let's talk about your weight," I said, offering a reassuring smile. It didn't seem to work. I still think about the look of shame on my patient's mom's face, as if her daughter's obesity were a personal failing. © 2019 npr

Keyword: Obesity
Link ID: 26302 - Posted: 06.05.2019

By Jon Morgenstern The nation’s growing addiction crisis has amplified the urgent and long-standing need for integrating research into substance abuse treatment and recovery process. While there has been an increase in research activity focused on addiction issues, the challenge is that it often takes a decade or more before important clinical findings can be implemented into real-world care delivery. How can the industry address this problem and make continuous quality improvement a cornerstone of substance abuse treatment? I believe we need to create addiction treatment learning laboratories that are embedded into, and coexist with, treatment and recovery centers. The goal of this approach is to accelerate the translation of basic science discoveries into actionable treatment methodologies that can be shared with and help advance the work of addiction professionals nationwide. While research has generated evidence of treatment efficacy in highly controlled settings, there is limited understanding of how to apply this knowledge in ongoing care regimens. For example, most programs offer a variety of different treatments, but there is no research on the impact of these multicomponent programs or how to tailor care to the unique problems of individual patients. © 2019 Scientific American

Keyword: Drug Abuse
Link ID: 26301 - Posted: 06.05.2019

Nicole Karlis There is no way Leonardo da Vinci could have predicted that the Mona Lisa would remain one of the most widely-debated works of art in modern day — thanks in no small part to her intriguing expression. Indeed, as one of the most famous paintings in the world, Mona Lisa's facial expression continues to beguile both commoners and academics. A 2017 study published in the journal Scientific Reports (part of the network of Nature's journals) proclaimed that Mona Lisa’s smile did indeed depict genuine happiness, according to the study's subjects who compared it with subtly manipulated facial expressions. Now, a new study published in the neuroscience journal Cortex says that her smile is non-genuine. In other words, she's faking it. The three neuroscience and cognition researchers who penned the article fixated on the asymmetry of Mona Lisa’s smile. Some historical theories suggest the facial asymmetry is due to the loss of the subject's anterior teeth, while others have speculated it could have been related to Bell’s Palsy. The Cortex article's authors note that as the upper part of her face does not appear to be active, it is possible to interpret her smile as “non-genuine.” This would relate to theories of emotion neuropsychology, which is the characterization of the behavioral modifications that follow a neurological condition. © 2018 Salon Media Group, Inc

Keyword: Emotions; Vision
Link ID: 26300 - Posted: 06.05.2019

By Frances Cronin Health reporter Alison Cameron, from Dorset, was 17 when she had appendicitis and went into hospital. "I had my appendix out and I remember I came round out of the anaesthetic screaming, the pain was something else." It was the start of a "horrendous" three years of investigation before "they came to the conclusion through a process of elimination, it was nerve damage". Over the next 30 years, Alison had more than 50 injections, known as cryoblocks, to freeze the site of her abdominal pain, but none of them stopped the pain for more than six months. This left her needing high doses of painkillers which left her unable to eat or drink - and she ended up on a feeding tube which led to her losing weight, and her health deteriorating. But she says she always tried to stay positive, which was instilled in her by her mum. "No matter how bad things have been, I've always been able to find a positive at the end of the day. That isn't saying that I didn't have some very, very low moments. "I miscarried seven times - six of which were definitely down to the pain. So not only have I paid the price - but also those potential lives." She managed to have two children in the gaps between treatment, and now has three grandchildren. The eldest burst into tears the first time she saw Alison without an eating tube, "as that, for her, wasn't normal granny". Five years ago, a cryoblock caused a collapsed lung, and Alison was referred to consultant neurosurgeon Girish Vajramani at the University Hospital Southampton. "Alison is one of the most challenging patients I have ever known," he says. "She had undergone 50 cryoblocks over 30 years, which is unprecedented, and resulted in her referral to me when this proved too dangerous." © 2019 BBC

Keyword: Pain & Touch
Link ID: 26299 - Posted: 06.05.2019

Laura Sanders In a nighttime experiment called the Dream Catcher, people’s dreams slipped right through the net. Looking at only the brain wave activity of sleeping people, scientists weren’t able to reliably spot a dreaming brain. The details of that leaky net, described May 27 at bioRxiv.org, haven’t yet been reviewed by other scientists. And the results are bound to be heavily scrutinized, as they run counter to earlier work that described signs of dreams in neural data. The experimental design matters, because scientists suspect that dreams hold clues about the deepest mystery of the mind — consciousness itself. The brain can create rich tapestries of awareness even in the complete absence of incoming information. Studying these instances of brain-created consciousness, which include dreaming, mind-wandering and daydreaming, “is a powerful way to understand the relationship between the brain and the mind,” says study coauthor Naotsugu Tsuchiya of Monash University in Clayton, a town near Melbourne, Australia. Tsuchiya and his colleagues analyzed data generated from nine people who slept overnight in a laboratory while wearing an electrode cap that measured brain waves. The researchers focused on a stage of sleep called non-REM sleep. (Dreams are so abundant during REM sleep that researchers would have been hard-pressed to find enough instances of nondream sleep to use as a comparison.) To identify dreams, researchers employed an irritating method: They would wake up a person once he or she had entered non-REM sleep, and ask whether the person had been dreaming. To keep the experiment free from unintentional biases, the project relied on two teams of researchers: data collectors and data analyzers. Once the collectors had gathered brain wave data on both dreams and nondreams, the data was handed over to Tsuchiya and other data analyzers without any clues about the subjects, including whether they were dreaming. |© Society for Science & the Public 2000 - 2019.

Keyword: Sleep
Link ID: 26298 - Posted: 06.04.2019

By Amitha Kalaichandran, M.D. It was 11 p.m. and my 5-year-old patient was sleeping peacefully in her hospital bed, snuggled up with her mother and several stuffed animals. Her breathing was quiet and soft. Her bedside heart rate monitor, which glowed a faint yellow in the dark hospital room, was turned to “silent.” “Sorry, I have to take a listen to her heart,” I whispered to her mother, tapping her shoulder lightly. Her mother and I had a good relationship: I had served as an advocate for her daughter several times during her seven-week stay in the ward. She had a rare disease that had been a medical mystery for many months, but she would be transferred to a more specialized center soon. I hated to wake her, but recently, when I had offered to wait to examine a child until after a nap, my attending physician had scolded: “You can’t care about that. If you do, you’ll never examine them. They have to get used to it — they’re in the hospital, after all.” But the poor girl was tired. She was poked three times a day for blood and taken to the M.R.I. or CT scanner at various times. I completed my exam: her vital signs, her heart, perfusion (how well her heart was pumping blood to her body), and palpated her abdomen to check her liver and spleen (which were enlarged, but no more than they had been). She seemed stable. I backed out slowly. The next morning, the girl’s mother mentioned that it had taken another hour for her to fall asleep again. Was there anything that we could do to allow her to sleep through the night? Wouldn’t a good night’s sleep help with her condition? She had a point. © 2019 The New York Times Company

Keyword: Sleep
Link ID: 26297 - Posted: 06.04.2019

By Larissa Zimberoff At the urging of doctor friends and a few popular books, I embarked on a diet plan earlier this year called intermittent fasting. The basics are that I could eat the foods I enjoyed and most of my regular meals, but it had to be within a short time frame of eight to 10 hours. Outside of that, I would stick to water, tea and black coffee. Proponents of the plan, also known as time-restricted eating, say that intermittent fasting could help me lose weight, always a worthwhile goal. It would also give my gut a much-needed break from processing food, improve focus and lessen daily inflammation. In the long-term, it might even help me live longer. I’ll admit, the words “intermittent fasting” sounded a little daunting. But Dr. Jason Fung, author of “The Obesity Code,” assured me that it could easily be incorporated into my daily routine. “Anytime you’re not eating is a fast — anything above four hours is fasting,” he said. “A lot of times people eat because they have to, versus really enjoying what they are eating. If you don’t want the sandwich, skip it. Your body knows what to do, it will take your body fat. That’s why you carry it around with you.” In other words, by voluntarily submitting to an absence of food for long periods during the day, my body would transition from burning sugar for fuel to burning fat. Two things made me think I might be able to stick with an intermittent fasting plan. First, I have Type 1 diabetes, which means eating requires thinking. For most of my life, I have spent my days making in-air computations about what I might or might not consume: weighing pros and cons about specific foods while factoring in things like carbs, fat and fiber. Protein too, if I’m super diligent. The more I eat, the more I have to think. © 2019 The New York Times Company

Keyword: Obesity
Link ID: 26296 - Posted: 06.04.2019

Nell Greenfieldboyce At the Marine Biological Laboratory in Woods Hole, Mass., there's a room filled with burbling aquariums. A lot of them have lids weighed down with big rocks. "Octopuses are notorious for being able to, kind of, escape out of their enclosures," says Bret Grasse, whose official title at MBL is "manager of cephalopod operations" — cephalopods being squid, cuttlefish and octopuses. He's part of a team that's trying to figure out the best ways to raise these sea creatures in captivity, so that scientists can investigate their genes and learn the secrets of their strange, almost alien ways. For decades, much of the basic research in biology has focused on just a few, well-studied model organisms like mice, fruit flies, worms and zebrafish. That's because these critters are easy to keep in the laboratory, and scientists have worked out how to routinely alter their genes, leading to all kinds of insights into behavior, diseases and possible treatments. "With these organisms, you could understand what genes did by manipulating them," says Josh Rosenthal, another biologist at MBL. "And that really became an indispensable part of biology." But it's also meant that basic biology has ignored much of the animal kingdom, especially its more exotic denizens. "We're really missing out on, I would say, the diversity of biology's solutions to problems," Rosenthal notes. © 2019 npr

Keyword: Learning & Memory; Evolution
Link ID: 26295 - Posted: 06.04.2019

By Robert D. McFadden Dr. James S. Ketchum, an Army psychiatrist who in the 1960s conducted experiments with LSD and other powerful hallucinogens using volunteer soldiers as test subjects in secret research on chemical agents that might incapacitate the minds of battlefield adversaries, died on May 27 at his home in Peoria, Ariz. He was 87. His wife, Judy Ketchum, confirmed the death on Monday, adding that the cause had not been determined. Decades before a convention eventually signed by more than 190 nations outlawed chemical weapons, Dr. Ketchum argued that recreational drugs favored by the counterculture could be used humanely to befuddle small units of enemy troops, and that a psychedelic “cloud of confusion” could stupefy whole battlefield regiments more ethically than the lethal explosions and flying steel of conventional weapons. For nearly a decade he spearheaded these studies at Edgewood Arsenal, a secluded Army chemical weapons center on Chesapeake Bay near Baltimore, where thousands of soldiers were drugged. Some could be found mumbling as they pondered nonexistent objects, or picking obsessively at bedclothes, or walking about in dreamlike deliriums. Asked to perform reasoning tests, some subjects could not stop laughing. It sometimes took days for the effects to wear off, and even then, Dr. Ketchum wrote in a self-published memoir, many displayed irrational aggressions and fears. He built padded rooms to minimize injuries, but occasionally one would escape. Some soldiers smashed furniture or menaced others, imagining they were running from hordes of rats or killers. “The idea of chemical weapons is still preferable to me, depending on how they are used, as a way of neutralizing an enemy,” Dr. Ketchum told The New York Times in an interview for this obituary in 2016, a half-century after his groundbreaking experiments. “They are still more humane than conventional weapons currently being used, if the public can ever get over its psychological block of being afraid of chemical weapons.” © 2019 The New York Times Company

Keyword: Drug Abuse
Link ID: 26294 - Posted: 06.04.2019

By Virginia Morell Most of us can look at two meal plates and easily tell which one has more food on it. But if someone turns out the lights, we’re out of luck. Not so for Asian elephants. A new study reveals that the pachyderms can judge food quantity merely by using their sense of smell, the first time an animal has been shown to do this. To conduct the research, scientists presented six Asian elephants (Elephas maximus) at an educational sanctuary in Thailand with two opaque, locked buckets containing 11 different ratios of sunflower seeds, a favorite treat. The elephants could not see how many seeds each bucket contained, but they could smell the contents through small holes in the lids. The animals chose the bucket with the greater quantity of food 59% to 82% of the time, the team reports today in the Proceedings of the National Academy of Sciences. (Even dogs, with their famed sense of smell, fail this test, other research has shown.) The discovery makes sense, the scientists say, because elephants are known to have the highest number of genes associated with olfactory reception of any species (about 2000 versus dogs’ 811). They can distinguish between the scent of Maasai pastoralists and Kamba farmers, and rely on their sense of smell to navigate long distances to find food and water (up to 19.2 kilometers). The researchers hope their findings could help mitigate human-elephant conflicts in Asia and Africa, because wandering herds use odors to decide where to travel; enticing scents might help lure them away from agricultural fields, for instance. © 2019 American Association for the Advancement of Science

Keyword: Chemical Senses (Smell & Taste)
Link ID: 26293 - Posted: 06.04.2019

By Jane E. Brody When a child is born with a rare disorder that few doctors recognize or know how to manage, it can pay big dividends for parents to be proactive, learn everything they can about the condition, and with expert medical guidance, come up with the best way to treat it. That is the approach Lara C. Pullen of Chicago adopted when her son, Kian Tan, was born 15 years ago last month at 7½ pounds, seemingly well-formed and healthy. But within 24 hours, Dr. Pullen, who already had two daughters, said Kian had stopped moving, wouldn’t nurse and felt as floppy as a rag doll. Two and a half weeks later, a genetic test showed that Kian had Prader-Willi syndrome, a genetic disorder that occurs once in every 15,000 to 25,000 live births. While at first it is a struggle to get enough food into these babies because they’re too weak to suck, within two or three years their main symptom is an insatiable appetite that results in extreme obesity unless the child, who is driven by constant hunger, is kept from sneaking and stealing food. Prader-Willi syndrome is caused by the failed expression of several genes on chromosome 15 derived from the child’s father. The genes are either missing or inactivated by a mistake that occurs during sperm development or, in some cases, the father’s entire chromosome 15 is not inherited by the fetus. The disorder is only rarely inherited, but when a father has Prader-Willi syndrome caused by a deletion in chromosome 15, there’s a 50 percent chance each child he fathers will inherit the defective chromosome. In addition to an excessive appetite, its range of symptoms includes short stature, sleep apnea, extreme daytime sleepiness, visual defects, underdeveloped genital organs, poor coordination, mild to moderate intellectual disability, speech problems, a high tolerance for pain, temper tantrums, obsessive behaviors and blood sugar irregularities. © 2019 The New York Times Company

Keyword: Obesity; Genes & Behavior
Link ID: 26292 - Posted: 06.03.2019