Joe Palca Most of us have been tempted at one time or another by the lure of sugar. Think of all the cakes and cookies you consume between Thanksgiving and Christmastime! But why are some people unable to resist that second cupcake or slice of pie? That's the question driving the research of Monica Dus, a molecular biologist at the University of Michigan. She wants to understand how excess sugar leads to obesity by understanding the effect of sugar on the brain. Dus's interest in how animals control the amount they eat started with a curious incident involving her two Bichon Frise dogs. One day, Cupcake and Sprinkles got into a bag of dog treats when Dus wasn't around. The dogs overdid it. "I couldn't believe that these two tiny, 15-pound animals had huge bellies for three days and they couldn't stop themselves from eating," she recalls. Dus was already an expert in fruit fly genetics, so she decided to study flies to see if she could unravel the puzzle of how the brain controls eating behavior. Her lab has a working hypothesis. Dus believes a diet high in sugar actually changes the brain, so it no longer does a good job of knowing how many calories the body is taking in. She thinks there are persistent molecular changes in the brain over time – changes that pave the way for excessive eating and eventually, obesity. Monica Dus is a researcher at the University of Michigan. She just won a $1.5 million Young Innovator grant from the National Institutes of Health to study how a high-sugar diet may lead to obesity by changing brain chemistry. © 2016 npr

Keyword: Obesity
Link ID: 22725 - Posted: 10.05.2016

Urine could potentially be used for a quick and simple way to test for CJD or "human mad cow disease", say scientists in the journal JAMA Neurology. The Medical Research Council team say their prototype test still needs honing before it could be used routinely. Currently there is no easy test available for this rare but fatal brain condition. Instead, doctors have to take a sample of spinal fluid or brain tissue, or wait for a post-mortem after death. What they look for is tell-tale deposits of abnormal proteins called prions, which cause the brain damage. Building on earlier US work, Dr Graham Jackson and colleagues, from University College London, have now found it is also possible to detect prions in urine. This might offer a way to diagnose CJD rapidly and earlier, they say, although there is no cure. Creutzfeldt-Jakob disease (CJD): CJD is a rare, but fatal degenerative brain disorder caused by abnormal proteins called prions that damage brain cells. There are several forms of the disease: sporadic, which occurs naturally in the human population, and accounts for 85% of all CJD cases variant CJD, linked to eating beef infected by bovine spongiform encephalopathy (BSE) iatrogenic infection, caused by contamination during medical or surgical treatment In the 1990s it became clear that a brain disease could be passed from cows to humans. The British government introduced a ban on beef on the bone. Since then, officials have kept a close check on how many people have become sick or died from CJD. © 2016 BBC

Keyword: Prions
Link ID: 22724 - Posted: 10.05.2016

By Emily Underwood When you let forth a big, embarrassing yawn during a boring lecture or concert, you succumb to a reflex so universal among animals that Charles Darwin mentioned it in his field notes. “Seeing a dog & horse & man yawn, makes me feel how much all animals are built on one structure,” he wrote in 1838. Scientists, however, still don’t agree on why we yawn or where it came from. So in a new study, researchers watched YouTube videos of 29 different yawning mammals, including mice, kittens, foxes, hedgehogs, walruses, elephants, and humans. (Here is a particularly cute montage used in the study.) They discovered a pattern: Small-brained animals with fewer neurons in the wrinkly outer layer of the brain, called the cortex, had shorter yawns than large-brained animals with more cortical neurons, the scientists report today in Biology Letters. Primates tended to yawn longer than nonprimates, and humans, with about 12,000 million cortical neurons, had the longest average yawn, lasting a little more than 6 seconds. African elephants, whose brains are close to the same weight as humans’ and have a similar number of cortical neurons, lasted about 6 seconds. The yawns of tiny-brained mice, in contrast, were less than 1.5 seconds in duration. The study lends support to a long-held hypothesis that yawning has an important physiological effect, such as increasing blood flood to the brain and cooling it down, the scientists say. © 2016 American Association for the Advancement of Science.

Keyword: Evolution; Emotions
Link ID: 22723 - Posted: 10.05.2016

By GINA KOLATA It is not easy to be fat in America, even though more than a third of adults are obese. Donald J. Trump brought the issue of fat shaming to the fore during and after last week’s debate, when he disparaged a former Miss Universe winner who gained weight and when he said the hacking of the Democratic National Committee’s emails might have been done by “somebody sitting on their bed that weighs 400 pounds.” But there also is a body of evidence showing that the effects of fat shaming and stigmatizing go far beyond such remarks, beyond the stares fat people get on the street, the cutting comments strangers make about their weight and the “funny” greeting cards featuring overweight people. It turns out that fat prejudice differs from other forms in ways that make it especially difficult to overcome. The problems with fat shaming start early. Rebecca Puhl, the deputy director of the University of Connecticut’s Rudd Center for Food Policy and Obesity, and her colleagues find that weight is the most common reason children are bullied in school. In one study, nearly 85 percent of adolescents reported seeing overweight classmates teased in gym class. Dr. Puhl and her colleagues asked fat kids who was doing the bullying. It turned out that it was not just friends and classmates but also teachers and — for more than a third of the bullied — parents. “If these kids are not safe at school or at home, where are they going to be supported?” Dr. Puhl asked. The bullying problem is not limited to the United States. Dr. Puhl and her colleagues found the same situation in Canada, Australia and Iceland. Women face harsher judgment than men, Dr. Puhl reports. The cutting remarks can begin when a woman’s body mass index is in the overweight range, while for men the shaming tends to start when they are obese. And women who are obese report more than three times as much shaming and discrimination as men of equal obesity. © 2016 The New York Times Company

Keyword: Obesity; Emotions
Link ID: 22722 - Posted: 10.02.2016

By Rebecca Robbins, In the months before his death, Robin Williams was besieged by paranoia and so confused he couldn’t remember his lines while filming a movie, as his brain was ambushed by what doctors later identified as an unusually severe case of Lewy body dementia. “Robin was losing his mind and he was aware of it. Can you imagine the pain he felt as he experienced himself disintegrating?” the actor’s widow, Susan Schneider Williams, wrote in a wrenching editorial published this week in the journal Neurology. The title of her piece: “The terrorist inside my husband’s brain.” Susan Williams addressed the editorial to neurologists, writing that she hoped husband’s story would “help you understand your patients along with their spouses and caregivers a little more.” Susan Williams has previously blamed Lewy body dementia for her husband’s death by suicide in 2014. About 1.3 million Americans have the disease, which is caused by protein deposits in the brain. Williams was diagnosed with Parkinson’s disease a few months before he died; the telltale signs of Lewy body dementia in his brain were not discovered until an autopsy. The editorial chronicles Williams’s desperation as he sought to understand a bewildering array of symptoms that started with insomnia, constipation, and an impaired sense of smell and soon spiraled into extreme anxiety, tremors, and difficulty reasoning. © 2016 Scientific American,

Keyword: Alzheimers
Link ID: 22721 - Posted: 10.02.2016

By Carl Luepker For the past 35 years, a relentless neurological disorder has taken over my body, causing often painful muscle spasms that make it hard for me to walk and write and that cause my speech to be garbled enough that people often can’t understand me I can live with my bad luck in getting this condition, which showed up when I was 10; what’s harder to accept is that I have passed on this disorder, carried in my genes, to my 11-year-old son, Liam. As a parent, you hope that your child’s life will follow an upward trend, one of emotional and physical growth toward an adulthood of wide-open possibilities where they can explore the world, challenge themselves emotionally and physically, and perhaps play on a sports team. And you hope that you can pass down to your child at least some of what was passed down to you. Yet my generalized dystonia, as my progressive condition is called, was one thing I had hoped would end with me. Liam poses for a photograph just months before his diagnosis with dystonia. He “has just moved into middle school,” his father writes, where “he will have to both advocate for himself and educate his new teachers and peers about this genetic disorder.” When my wife and I started thinking of having kids, the statistics were fairly reassuring: There was a 1-in-2 chance that our child would inherit the gene that causes the disorder, but most people who have the gene don’t go on to manifest dystonia. We wanted a family and rolled the dice — twice. Our daughter does not have the gene. © 1996-2016 The Washington Post

Keyword: Movement Disorders; Genes & Behavior
Link ID: 22720 - Posted: 10.02.2016

Ben Allen Louis Casanova is playing cards with a friend on the back deck of a recovery house in Philadelphia's northern suburbs. He's warm and open as he talks about his past few years. The guy everyone calls Louie started using drugs like Xanax and Valium during his freshman year of high school. At age 18, Casanova turned to heroin. About two years later, the rehab shuffle began. "I relapsed and then I was just getting high. And then I went to treatment again in February of 2015," he says. "Then I relapsed again and went back to treatment." He's 23 now. He's hurt people close to him and his criminal record, fueled by his drug addiction, is long. By Louie's count, he has been through eight inpatient rehabs. Louis says his stays have ranged from about 18 to 45 days. "I did 30 days, and after that I came here," he concludes, talking about his latest visit. A month's stay can be pretty typical among people who go to an inpatient facility. But why? "As far as I know, there's nothing magical about 28 days," says Kimberly Johnson, director of the Center for Substance Abuse Treatment at SAMHSA, the federal agency that studies treatment services. Anne Fletcher, author of the book Inside Rehab, agrees. "It certainly is not scientifically based," she says. "I live in Minnesota where the model was developed and a lot of treatment across the country really stemmed from that." She says the late Daniel Anderson was one of the primary architects of the "Minnesota model," which became the prevailing treatment protocol for addiction specialists. At a state hospital in Minnesota in the 1950s, Anderson saw alcoholics living in locked wards, leaving only to be put to work on a farm. © 2016 npr

Keyword: Drug Abuse
Link ID: 22719 - Posted: 10.02.2016

By NICHOLAS BAKALAR Hormonal contraceptives are associated with an increased risk for depression, a large study has found. Danish researchers studied more than a million women ages 15 to 34, tracking their contraceptive and antidepressant use from 2000 to 2013. The study excluded women who before 2000 had used antidepressants or had another psychiatric diagnosis. Over all, compared with nonusers, users of hormonal contraception had an 80 percent increased risk of depression. Some types of contraceptives carried even greater risk. Women who used progestin-only pills more than doubled their risk, for example, while those who used those who used the levonorgestrel IUD (brand name Mirena) tripled their risk. The risk persisted after adjusting for age, age of first intercourse, educational level and other factors. The study, in JAMA Psychiatry, also found that the risk was greater in adolescent girls, but this may be because adolescent girls are especially susceptible to depression. “Even though the risk of depression increases substantially with these drugs — an 80 percent increase is not trivial — most women who use them will not get depressed,” said the senior author, Dr. Oejvind Lidegaard, a clinical professor of obstetrics and gynecology at the University of Copenhagen. “Still, it is important that we tell women that there is this possibility. And there are effective nonhormonal methods of birth control.” © 2016 The New York Times Company

Keyword: Depression; Hormones & Behavior
Link ID: 22718 - Posted: 10.02.2016

Susan Milius ORLANDO, Fla. — When sex chromosomes among common pill bugs go bad from disuse, borrowed bacterial DNA comes to the rescue. Certain pill bugs grow up female because of sex chromosomes cobbled together with genes that jumped from the bacteria. Genetic analysis traces this female-maker DNA to Wolbachia bacteria, Richard Cordaux, based at the University of Poitiers with France’s scientific research center CNRS, announced September 29 at the International Congress of Entomology. Various kinds of Wolbachia infect many arthropods, spreading from mother to offspring and often biasing their hosts’ sex ratios toward females (and thus creating even more female offspring). In the common pill bug (Armadillidium vulgare), Wolbachia can favor female development two ways. Just by bacterial infection without any gene transfer, bacteria passed down to eggs can make genetic males develop into functional females. Generations of Wolbachia infections determining sex let these pill bugs’ now-obsolete female-making genes degenerate. Which makes it very strange that certain populations of pill bugs with no current Wolbachia infection still produce abundant females. That’s where Cordaux and Poitier colleague Clément Gilbert have demonstrated a second way that Wolbachia makes lady pill bugs — by donating DNA directly to the pill bug genes. The researchers, who share an interest in sex determination, have built a case that Wolbachia inserted feminizing genes into pill bug chromosomes. The bacterial genes thus created a new sex chromosome. 5|© Society for Science & the Public 2000 - 2016

Keyword: Sexual Behavior
Link ID: 22717 - Posted: 10.02.2016

Mia Persson Dogs may look to humans for help in solving impossible tasks thanks to some genes previously linked to social disorders in people. Beagles with particular variants in a gene associated with autism were more likely to sidle up to and make physical contact with a human stranger, researchers report September 29 in Scientific Reports. That gene, SEZ6L, is one of five genes in a particular stretch of beagle DNA associated with sociability in the dogs, animal behaviorist Per Jensen and colleagues at Linköping University in Sweden say. Versions of four of those five genes have been linked to human social disorders such as autism, schizophrenia and aggression. “What we figure has been going on here is that there are genetic variants that tend to make dogs more sociable and these variants have been selected during domestication,” Jensen says. But other researchers say the results are preliminary and need to be confirmed by looking at other dog breeds. Previous genetic studies of dog domestication have not implicated these genes. But, says evolutionary geneticist Bridgett vonHoldt of Princeton University, genes that influence sociability are “not an unlikely target for domestication — as humans, we would be most interested in a protodog that was interested in spending time with humans.” |© Society for Science & the Public 2000 - 2016.

Keyword: Autism; Genes & Behavior
Link ID: 22716 - Posted: 09.30.2016

By MAIA SZALAVITZ Drug education is the only part of the middle school curriculum I remember — perhaps because it backfired so spectacularly. Before reaching today’s legal drinking age, I was shooting cocaine and heroin. I’ve since recovered from my addiction, and researchers now are trying to develop innovative prevention programs to help children at risk take a different road than I did. Developing a public antidrug program that really works has not been easy. Many of us grew up with antidrug programs like D.A.R.E. or the Nancy Reagan-inspired antidrug campaign “Just Say No.” But research shows those programs and others like them that depend on education and scare tactics were largely ineffective and did little to curb drug use by children at highest risk. But now a new antidrug program tested in Europe, Australia and Canada is showing promise. Called Preventure, the program, developed by Patricia Conrod, a professor of psychiatry at the University of Montreal, recognizes how a child’s temperament drives his or her risk for drug use — and that different traits create different pathways to addiction. Early trials show that personality testing can identify 90 percent of the highest risk children, targeting risky traits before they cause problems. Recognizing that most teenagers who try alcohol, cocaine, opioids or methamphetamine do not become addicted, they focus on what’s different about the minority who do. © 2016 The New York Times Company

Keyword: Drug Abuse
Link ID: 22715 - Posted: 09.30.2016

By Jessica Boddy Activity trackers like Fitbits and Jawbones help fitness enthusiasts log the calories they burn, their heart rates, and even how many flights of stairs they climb in a day. Biologist Cory Williams of Northern Arizona University in Flagstaff is using similar technology to track the energy consumption of arctic ground squirrels in Alaska—insight that may reveal how the animals efficiently forage for food while avoiding being picked off by golden eagles. This week, Williams published a study in Royal Society Open Science that compared the activity levels of male and female squirrels. He found that although males spend a lot more time outside of their burrows, they’re pretty lazy, and sometimes just bask in the sun during warmer months. Females, on the other hand, have limited time to spare when caring for their young, and use it to run around and forage for themselves and their babies. In addition to previous work on arctic ground squirrel hibernation and seasonal differences in behavior, the finding is helping his team figure out why males tend to be more susceptible to being eaten. Williams sat down with Science to talk about creating a squirrel Fitbit, catching the animals in the wild, and how technology is improving ecological research. This interview has been edited for brevity and clarity. Q: What got you interested in studying arctic ground squirrels? A: It’s one of the only arctic animals that keeps a rigid schedule even when there’s no light/dark cycle for 6 week—meaning, they emerge from and return to their burrows the same time every day and they eat the same time each day, even though the sun stays in the sky for weeks and weeks. So I started to deploy the energy tracking technologies to better understand how the squirrels use energy through the seasons. © 2016 American Association for the Advancement of Science

Keyword: Sexual Behavior
Link ID: 22714 - Posted: 09.30.2016

By Deborah R. Glasofer, Joanna Steinglass Every day on the dot of noon, Jane* would eat her 150-calorie lunch: nonfat yogurt and a handful of berries. To eat earlier, she felt, would be “gluttonous.” To eat later would disrupt the dinner ritual. Jane's eating initially became more restrictive in adolescence, when she worried about the changes her body was undergoing in the natural course of puberty. When she first settled on her lunchtime foods and routine—using a child-size spoon to “make the yogurt last” and sipping water between each bite—she felt accomplished. Jane enjoyed her friends' compliments about her “incredible willpower.” In behavioral science terms, her actions were goal-directed, motivated by achieving a particular outcome. In relatively short order, she got the result she really wanted: weight loss. Years later Jane, now in her 30s and a newspaper reporter, continued to eat the same lunch in the same way. Huddled over her desk in the newsroom, she tried to avoid unwanted attention and feared anything that might interfere with the routine. She no longer felt proud of her behavior. Her friends stopped complimenting her “self-control” years ago, when her weight plummeted perilously low. So low that she has had to be hospitalized on more than one occasion. The longed-for weight loss did not make her feel better about herself or her appearance. Jane's curly hair, once shiny and thick, dulled and thinned; her skin and eyes lost their brightness. There were other costs as well—to her relationships, to her career. Instead of dreaming about a great romance, Jane would dream of the cupcakes she could not let herself have at her niece's birthday party. Instead of thinking about the best lead for her next story, she obsessed over calories and exercise. © 2016 Scientific American

Keyword: Anorexia & Bulimia; Attention
Link ID: 22713 - Posted: 09.30.2016

Emily Underwood To human observers, bumblebees sipping nectar from flowers appear cheerful. It turns out that the insects may actually enjoy their work. A new study suggests that bees experience a “happy” buzz after receiving a sugary snack, although it’s probably not the same joy that humans experience chomping on a candy bar. Scientists can’t ask bees or other animals how they feel. Instead, researchers must look for signs of positive or negative emotions in an animal’s decision making or behavior, says Clint Perry, a neuroethologist at Queen Mary University of London. In one such study, for example, scientists shook bees vigorously in a machine for 60 seconds — hard enough to annoy, but not hard enough to cause injury — and found that stressed bees made more pessimistic decisions while foraging for food. The new study, published in the Sept. 30 Science, is the first to look for signs of positive bias in bee decision making, Perry says. His team trained 35 bees to navigate a small arena connected to a plastic tunnel. When the tunnel was marked with a blue flower, the bees learned that a tasty vial of sugar water awaited them at its end. When a green flower was present, there was no reward. Once the bees learned the difference, the scientists threw the bees a curveball: Rather than being blue or green, the flower had a confusing blue-green hue. Faced with the ambiguous blossom, the bees appeared to dither, meandering around for roughly 100 seconds before deciding whether to enter the tunnel. Some didn’t enter at all. But when the scientists gave half the bees a treat — a drop of concentrated sugar water — that group spent just 50 seconds circling the entrance before deciding to check it out. Overall, the two groups flew roughly the same distances at the same speeds, suggesting that the group that had gotten a treat first had not simply experienced a boost in energy from the sugar, but were in a more positive, optimistic state, Perry says. |© Society for Science & the Public 2000 - 2016.

Keyword: Emotions; Evolution
Link ID: 22712 - Posted: 09.30.2016

Jon Hamilton What rats can remember may help people who forget. Researchers are reporting evidence that rats possess "episodic memories," the kind of memories that allow us to go back in time and recall specific events. These memories are among the first to disappear in people who develop Alzheimer's disease. The finding, which appears Thursday in Current Biology, suggests that rats could offer a better way to test potential drugs for Alzheimer's. Right now, most of these drugs are tested in mice. "We need to have a way to study the exact type of memory that we think is impaired in Alzheimer's disease," says Bruce Lamb, a professor of medical and molecular genetics at Indiana University in Indianapolis. He was not involved in the study. The lack of an adequate animal model of Alzheimer's disease may be one reason drugs that seemed to work in mice have failed when given to people, Lamb says. Loss of episodic memories, especially recent ones, is a key sign of Alzheimer's, says Jonathon Crystal, an author of the study and director of the neuroscience program at Indiana University in Bloomington. "So if you visit your grandmother who has Alzheimer's, [she] isn't going to remember that you were visiting a couple of weeks ago and what you described about things that are going on in your life," he says. Crystal and a team of researchers thought rats might have some form of episodic memory. So they began doing studies that relied on the animals' remarkable ability to recognize a wide range of odors, like basil and banana and strawberry. © 2016 npr

Keyword: Alzheimers
Link ID: 22711 - Posted: 09.30.2016

By Carl Hart In early August the Drug Enforcement Administration declined to reclassify marijuana under the federal Controlled Substances Act. The drug is currently listed on Schedule I, meaning that it is viewed as having “no currently accepted medical use in treatment” and is therefore technically banned by federal law. The proposed change would have moved it to Schedule II, where it would join morphine, opium and codeine. That would make marijuana potentially available by prescription nationwide. Such a change would have been good for patients and scientists, and it would have represented a big step toward resolving the hypocritical mess that characterizes current law. Despite many people's assumptions to the contrary, the existing law does not ban scientific investigation into the harms and benefits of the drug. It's true that scientists studying marijuana must jump through multiple bureaucratic and regulatory hoops, and one of these just became a bit easier to navigate. Currently researchers who want to study the drug must get it from the University of Mississippi, which is the only university now permitted to grow marijuana plants for research purposes. When the DEA announced in August that it would not reschedule marijuana, it did say that it would let other institutions apply for permission to start growing the plants as well. That was a step in the right direction—but it's not enough. Despite the regulatory barriers, dozens of scientists—myself included—have been engaged in research on the harms and benefits of marijuana for decades, and the evidence shows that the drug has many helpful therapeutic uses. For example, it stimulates appetite in HIV-positive patients, which could be a lifesaver for someone suffering from AIDS wasting syndrome. It is also useful in the treatment of neuropathic pain, chronic pain, and spasticity caused by multiple sclerosis. © 2016 Scientific American

Keyword: Drug Abuse
Link ID: 22710 - Posted: 09.30.2016

By CATHERINE SAINT LOUIS Increasing numbers of children have high blood pressure, largely as a consequence of their obesity. A growing body of evidence suggests that high blood pressure may impair children’s cognitive skills, reducing their ability to remember, pay attention and organize facts. In the most comprehensive study to date, published on Thursday in The Journal of Pediatrics, 75 children ages 10 to 18 with untreated high blood pressure performed worse on several tests of cognitive function, compared with 75 peers who had normal blood pressure. The differences were subtle, and the new research does not prove that high blood pressure diminishes cognitive skills in children. Still, the findings set off alarm bells among some experts. “This study really shows there are some differences,” said Dr. David B. Kershaw, the director of pediatric nephrology at C. S. Mott Children’s Hospital at the University of Michigan, who was not involved with the research. “This was not just random chance.” Dr. Marc B. Lande, a professor of pediatric nephrology at the University of Rochester Medical Center, and his colleagues had children tested at four sites in three states, matching those with and without high blood pressure by age, maternal education, race, obesity levels and other factors. The researchers excluded children with learning disabilities and sleep problems, which can affect cognitive skills. Children with elevated blood pressure performed worse than their peers on tests of memory, processing speed and verbal skills, the researchers found. But all the scores were still in the normal range. Because of increased obesity, elevated blood pressure, also called hypertension, is no longer rare in children, though it is underdiagnosed. In a recent survey, about 3.5 percent of 14,187 children ages 3 to 18 had hypertension. © 2016 The New York Times Company

Keyword: ADHD; Obesity
Link ID: 22709 - Posted: 09.29.2016

Hannah Devlin Science correspondent Scientists have found the most definitive evidence yet that some people are destined to age quicker and die younger than others - regardless of their lifestyle. The findings could explain the seemingly random and unfair way that death is sometimes dealt out, and raise the intriguing future possibility of being able to extend the natural human lifespan. “You get people who are vegan, sleep 10 hours a day, have a low-stress job, and still end up dying young,” said Steve Horvath, a biostatistician who led the research at the University of California, Los Angeles. “We’ve shown some people have a faster innate ageing rate.” A higher biological age, regardless of actual age, was consistently linked to an earlier death, the study found. For the 5% of the population who age fastest, this translated to a roughly 50% greater than average risk of death at any age. Intriguingly, the biological changes linked to ageing are potentially reversible, raising the prospect of future treatments that could arrest the ageing process and extend the human lifespan. “The great hope is that we find anti-ageing interventions that would slow your innate ageing rate,” said Horvath. “This is an important milestone to realising this dream.” Horvath’s ageing “clock” relies on measuring subtle chemical changes, in which methyl compounds attach or detach from the genome without altering the underlying code of our DNA. © 2016 Guardian News and Media Limited

Keyword: Development of the Brain; Epigenetics
Link ID: 22708 - Posted: 09.29.2016

Rebecca Hersher A new study of violent behavior in more than 1,000 mammal species found the meerkat is the mammal most likely to be murdered by one of its own kind. The study, led by José María Gómez of the University of Grenada in Spain and published Wednesday in the journal Nature, analyzed more than 4 million deaths among 1,024 mammal species and compared them with findings in 600 studies of violence among humans from ancient times until today. The findings tell us two things: Some amount of violence between humans is attributable to our place on the evolutionary tree. Meerkats are surprisingly murderous. To be clear, the study's authors did not set out to prove (or disprove) a theory of meerkat violence; they were investigating what mammalian data might tell us about humans. But Ed Yong at The Atlantic organized the study's exhaustive list of mammals to make this helpful chart ranking animals by their murderousness. Some of the animals with reputations for docility are actually more dangerous to each other than creatures known for their aggression. Chinchillas kill each other more often than brown bears turn on their own kind. New Zealand sea lions are more murderous than actual lions. And, as you can see, about 20 percent of meerkat deaths are murders. Their violence has been documented; a 2006 study described in National Geographic documented meerkat mothers killing the offspring of other females to maintain dominance. © 2016 npr

Keyword: Aggression
Link ID: 22707 - Posted: 09.29.2016

By Clare Wilson IT HAS been blamed for brain shrinkage, impotence, divorce and paedophilia – and in April this year, Utah declared it a public health hazard. Warnings about pornography come not just from religious or conservative groups – former Playboy model and actor Pamela Anderson also recently cautioned against its “corrosive effects”. Yet survey after survey shows porn use is common among men and not exactly rare in women, so can it really be so dangerous? Or could it even have benefits? While there is research into the effects of porn, a great deal of it is contradictory. Even the same studies are interpreted differently by those on opposite sides of the debate. Some feel it is a menace to society, while others think that attitude belongs with 1980s hysteria over video nasties. Anti-porn campaigners chiefly argue that it is addictive and hijacks the brain’s normal reward pathways. Like heroin addicts who crave more of their drug to get the same high, users find they are no longer aroused by real sex and resort to increasingly harder-core material, or so the theory goes. Of course, there are other concerns over pornography, such as its depictions of violence, exploitation and sexual consent. But male addiction is an increasing focus of anti-porn campaigns. Campaigners say that an excess of porn prompts users to spurn their partners and seek out images of bestiality, rape scenes, and child abuse. Some schools in Scotland now warn that viewing adult images leads to impotence, coercion and abuse. “This kind of escalation is described over and over again,” says Gary Wilson, a retired biology lecturer and author of website and book Your Brain on Porn. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior
Link ID: 22706 - Posted: 09.29.2016