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For primary school children in China, spending an extra 45 minutes per day outside in a school activity class may reduce the risk of nearsightedness, or "myopia," according to a new study. In some parts of China, 90 per cent of high school graduates have nearsightedness, and rates are lower but increasing in Europe and the Middle East, the authors write. "There were some studies suggesting the protective effect of outdoor time in the development of myopia, but most of this evidence is from cross-sectional studies [survey] data that suggest 'association' instead of causality," said lead author Dr. Mingguang He of Sun Yat-sen University in Guangzhou. "Our study, as a randomized trial, is able to prove causality and also provide the high level of evidence to inform public policy." Intense levels of schooling and little time spent outdoors may have contributed to the epidemic rise of nearsightedness in China, he told Reuters Health by email. The researchers divided 12 primary schools in China into two groups: six schools continued their existing class schedule, while six were assigned to include an additional 40 minutes of outdoor activity at the end of each school day. Parents of children in the second group were also encouraged to engage their children in outdoor activities on the weekends. In total, almost 2,000 first-graders, with an average age of almost seven years old, were included. After three years, 30 per cent of the outdoor activity group had developed nearsightedness, compared to almost 40 per cent of kids in the control group, according to the results in JAMA. ©2015 CBC/Radio-Canada.

Keyword: Vision
Link ID: 21413 - Posted: 09.16.2015

By Emily DeMarco When it comes to finding a mate in the animal kingdom, females tend to gravitate toward males who appear strong and healthy. But a new study in zebra finches reveals that the small, gray-striped birds prefer mates with similar interests, such as a penchant for exploring the world. The drive for this compatibility is so strong that when scientists forced the females to mate up with males not of their choosing, the birds were more likely to cheat and shirk their parental duties, leading to more deaths among their chicks. The research “suggests that having a mate you’re behaviorally compatible with is very important from an evolutionary perspective for zebra finches,” says behavioral ecologist Sasha Dall of the University of Exeter, Cornwall, in the United Kingdom, who wasn’t involved in the study. Scientists have long been puzzled by female zebra finches. As opposed to females of other bird species, which tend to prefer males with brighter plumage or longer tails (traits that suggest that the males have good, healthy genes), female zebra finches seem to choose mates for some mysterious reason known only to each lady bird. Sometimes one will go for the guy with the bright red beak, sometimes the male with the thrilling song, sometimes neither. So what’s really driving this mate choice? In the past, scientists have speculated that a desire for compatibility might be the answer. But they have disagreed over whether the birds are on the lookout for males with the right genes (genetic compatibility between the partners might help lower the high rates of embryonic mortality seen in the species) or the right behaviors. © 2015 American Association for the Advancement of Science

Keyword: Sexual Behavior
Link ID: 21412 - Posted: 09.15.2015

By Larry Greenemeier Advanced prosthetics have for the past few years begun tapping into brain signals to provide amputees with impressive new levels of control. Patients think, and a limb moves. But getting a robotic arm or hand to sense what it’s touching, and send that feeling back to the brain, has been a harder task. The U.S. Defense Department’s research division last week claimed a breakthrough in this area, issuing a press release touting a 28-year-old paralyzed person’s ability to “feel” physical sensations through a prosthetic hand. Researchers have directly connected the artificial appendage to his brain, giving him the ability to even identify which mechanical finger is being gently touched, according to the Defense Advanced Research Projects Agency (DARPA). In 2013, other scientists at Case Western Reserve University also gave touch to amputees, giving patients precise-enough feeling of pressure in their fingertips to allow them to twist the stems off cherries. The government isn’t providing much detail at this time about its achievement other than to say that researchers ran wires from arrays connected to the volunteer’s sensory and motor cortices—which identify tactile sensations and control body movements, respectively—to a mechanical hand developed by the Applied Physics Laboratory (APL) at Johns Hopkins University. The APL hand’s torque sensors can convert pressure applied to any of its fingers into electrical signals routed back to the volunteer’s brain. © 2015 Scientific American

Keyword: Pain & Touch; Robotics
Link ID: 21411 - Posted: 09.15.2015

A choir of Canadians with Parkinson's disease is helping researchers test how well the performers regain facial movement to express emotions. Tremors and difficulty walking are often the most noticeable symptoms of Parkinson's disease, which affects about one in 500 people in Canada. Those with the disease may also have limited facial movement, which hampers the ability to express themselves. For people with Parkinson's who have "masked face syndrome," it can be difficult for others to decipher how they're feeling. That's because we unknowingly mimic or mirror each other during interaction to connect. "Within a hundred milliseconds of seeing someone else smile or frown, we are smiling or frowning," said Frank Russo, a psychology professor at Ryerson University in Toronto. "We're mirroring what the other person is doing. And that's one of the things that is absent in Parkinson's. It's the absence of mirroring that is leading to some of the deficit in understanding other people's emotions." Having a static face can leave people with Parkinson's seem cold and aloof as they also show deficits in understanding other people's emotions. The patient can then become emotionally disconnected from others. Studying the 28 members of the Parkinson's choir has bolstered Russo's thinking that singing, facial expressions and social communications are interconnected. So far Russo has found that mirroring effect or mimicry was restored among choir participants who sang for 13 weeks. ©2015 CBC/Radio-Canada.

Keyword: Parkinsons; Emotions
Link ID: 21410 - Posted: 09.15.2015

By Barbara S. Moffet It’s 1 in the morning and I’ve been in bed for a few hours now. Maybe it’s the few drops of caffeine I mistakenly drank earlier in the day. Or perhaps it’s the 26 wires that are attached to my scalp, face, finger and legs and the strap pulled taut around my waist. All I know is I’m not doing what you’re supposed to do in a sleep lab, and if I don’t fall asleep soon, it’ll be time to take off my pajamas and go home. I’m here because my doctor thought it was time to find out what was causing a cluster of possibly sleep-related health issues: snoring, frequent middle-of-the-night waking and some problems with concentrating that I’ve had most of my 63 years. I also have a genetic condition, Ehler-Danlos syndrome, that can cause airways to partially close during sleep. I’ve landed at Sleep Centers of Northern Virginia in Alexandria, one of at least two dozen sleep labs in the area. According to the National Institutes of Health, some 70 million Americans are “poor sleepers,” and the ramifications of inadequate shut-eye can range from grumpiness and lack of focus to heart disease, diabetes, high blood pressure and even a diminished life expectancy. Research published this year in the journal Neurology concluded that people with sleep apnea — a disorder that causes a person to repeatedly stop breathing during the night, rousing them from sleep — developed problems with cognition about 10 years earlier than other people.

Keyword: Sleep
Link ID: 21409 - Posted: 09.15.2015

John Peever, and Brian J. Murray, The function of sleep has mystified scientists for thousands of years, but modern research is providing new clues about what it does for both the mind and body. Sleep serves to reenergize the body's cells, clear waste from the brain, and support learning and memory. It even plays vital roles in regulating mood, appetite and libido. Sleeping is an integral part of our life, and as research shows, it is incredibly complex. The brain generates two distinct types of sleep—slow-wave sleep (SWS), known as deep sleep, and rapid eye movement (REM), also called dreaming sleep. Most of the sleeping we do is of the SWS variety, characterized by large, slow brain waves, relaxed muscles and slow, deep breathing, which may help the brain and body to recuperate after a long day. When we fall asleep, the brain does not merely go offline, as implied by the common phrase “out like a light.” Instead a series of highly orchestrated events puts the brain to sleep in stages. Technically sleep starts in the brain areas that produce SWS. Scientists now have concrete evidence that two groups of cells—the ventrolateral preoptic nucleus in the hypothalamus and the parafacial zone in the brain stem—are involved in prompting SWS. When these cells switch on, it triggers a loss of consciousness. After SWS, REM sleep begins. This mode is bizarre: a dreamer's brain becomes highly active while the body's muscles are paralyzed, and breathing and heart rate become erratic. The purpose of REM sleep remains a biological mystery, despite our growing understanding of its biochemistry and neurobiology. © 2015 Scientific American

Keyword: Sleep
Link ID: 21408 - Posted: 09.15.2015

By AMY HARMON Some neuroscientists believe it may be possible, within a century or so, for our minds to continue to function after death — in a computer or some other kind of simulation. Others say it’s theoretically impossible, or impossibly far off in the future. A lot of pieces have to fall into place before we can even begin to start thinking about testing the idea. But new high-tech efforts to understand the brain are also generating methods that make those pieces seem, if not exactly imminent, then at least a bit more plausible. Here’s a look at how close, and far, we are to some requirements for this version of “mind uploading.” The hope of mind uploading rests on the premise that much of the key information about who we are is stored in the unique pattern of connections between our neurons, the cells that carry electrical and chemical signals through living brains. You wouldn't know it from the outside, but there are more of those connections — individually called synapses, collectively known as the connectome — in a cubic centimeter of the human brain than there are stars in the Milky Way galaxy. The basic blueprint is dictated by our genes, but everything we do and experience alters it, creating a physical record of all the things that make us US — our habits, tastes, memories, and so on. It is exceedingly tricky to transition that pattern of connections, known as the connectome, into a state where it is both safe from decay and can be verified as intact. But in recent months, two sets of scientists said they had devised separate ways to do that for the brains of smaller mammals. If either is scaled up to work for human brains — still a big if — then theoretically your brain could sit on a shelf or in a freezer for centuries while scientists work on the rest of these steps. © 2015 The New York Times Company

Keyword: Learning & Memory; Consciousness
Link ID: 21407 - Posted: 09.14.2015

Patricia Neighmond Are you getting enough sleep, or not enough? If your answer to either of these questions is "yes," you may be at risk of heart disease. Just the right amount of good-quality sleep is key to good heart health, according to researchers at the Center for Cohort Studies at Kangbuk Samsung Hospital and Sungkyunkwan University School of Medicine in Seoul, South Korea. Poor sleep habits may put you at higher risk for early signs of heart disease, even at a relatively young age. The researchers studied more than 47,000 young and middle-aged men and women, average age around 41, who answered questions about how long and how well they slept. Then they had tests to measure their cardiovascular health. Early coronary lesions were detected by measuring the amount of calcium in the arteries of the heart. Stiffness of arteries was measured by the speed of blood coursing through the arteries in the upper arm and ankle. Calcium buildup and arterial stiffness are two important warning signs of oncoming heart disease. Findings showed that adults who slept less than five hours a night had 50 percent more calcium in their coronary arteries than those who slept seven hours. Those who slept nine hours or more a night had even worse outcomes, with 70 percent more coronary calcium compared to those who slept seven hours. © 2015 NPR

Keyword: Sleep
Link ID: 21406 - Posted: 09.14.2015

By CLYDE HABERMAN Perhaps no crime staggers the mind, or turns the stomach, more than the murder of a baby, and so it is not a surprise when law enforcement comes down hard on the presumed killers. Often enough, these are men and women accused of having succumbed to sudden rage or simmering frustration and literally shaken the life out of a helpless infant who would not stop crying or would not fall asleep. Shaken baby syndrome has been a recognized diagnosis for several decades, though many medical professionals now prefer the term abusive head trauma. It is defined by a constellation of symptoms known as the triad: brain swelling, bleeding on the surface of the brain and bleeding behind the eyes. For years, those three symptoms by themselves were uniformly accepted as evidence that a crime had been committed, even in the absence of bruises, broken bones or other signs of abuse. While many doctors, maybe most, still swear by the diagnosis, a growing number have lost faith. Not that they doubt that some babies have been abused. But these skeptics assert that factors other than shaking, and having nothing to do with criminal behavior, may sometimes explain the triad. Has the syndrome been diagnosed too liberally? Are some innocent parents and other caretakers being wrongly sent to prison? Those questions, at the complex intersection of medicine and the law, can stir strong emotions among doctors, parents and prosecutors. They shape this first installment in a new series of Retro Report, video documentaries that explore major news stories of the past and their enduring consequences. The video’s starting point is a Massachusetts criminal case that introduced the concept of shaken baby syndrome to many Americans: the 1997 murder trial of Louise Woodward, an 18-year-old British au pair accused of having shaken an 8-month-old boy, Matthew Eappen, so aggressively that he died. Matthew also had injuries that may have predated Ms. Woodward’s joining the Eappen family in Newton, outside Boston. The focus, however, was on the triad of symptoms. To prosecution witnesses, they proved that the baby had been shaken violently, his head hitting some hard surface. © 2015 The New York Times Company

Keyword: Brain Injury/Concussion; Development of the Brain
Link ID: 21405 - Posted: 09.14.2015

A study suggests that a chemical in dark chocolate and red wine can slow the progression of Alzheimer’s disease. But how conclusive is the data, and does this mean we should all drink more wine? New Scientist looks at the evidence. What is resveratrol? Found in grapes, red wine and dark chocolate, many claims have been made about resveratrol. It has been touted as a potential panacea for a range of age-related disorders, including cancer, diabetes and neurological problems, but so far most of the data supporting these claims has come from lab studies and work in animals. There have been only a few, small studies in humans. How might resveratrol protect us from age-related illness? Extremely calorie-restricted diets greatly reduce age-related diseases in lab animals. This is thought to happen through the activation of a group of enzymes called sirtuins, which seem to affect gene expression and protect against the effects of stress, including a poor diet. The hope is that resveratrol activates sirtuins to get the same benefits – like preventing the onset of age-related diseases, including Alzheimer’s – without having to stick to such a low-energy diet. But some experiments have suggested slowed ageing from caloric restriction may not be down to sirtuins after all. What does the latest study show? To see if resveratrol could delay the progression of Alzheimer’s disease in people , Scott Turner at Georgetown University Medical Centre in Washington DC and his team gave 119 people with mild to moderate symptoms of the disease either a gram of synthesised resveratrol twice a day in pills for a year, or a placebo. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers
Link ID: 21404 - Posted: 09.14.2015

James Gorman If spiders had nightmares, the larvae of ichneumonid wasps would have to star in them. The wasp lays an egg on the back of an orb weaver spider, where it grows fat and bossy, and occupies itself with turning the spider into a zombie. As Keizo Takasuka and his colleagues point out in The Journal of Experimental Biology, this is a classic case of “host manipulation.” Using more colorful language, he described the larva turning the spider into a “drugged navvy.” The larva forces the spider to turn its efforts away from maintaining a sticky, spiral web to catch prey, and to devote itself to building a safe and sturdy web to serve as a home for the larva’s cocoon, in which it will transform itself into a wasp. This process was well known, but Dr. Takasuka and Kaoru Maeto at Kobe University, working with other Japanese researchers, wanted to explore how the wasp overlords controlled their spiders. They suspected that the larvae were co-opting a natural behavior of the spiders. Turning on a behavior already in the spiders’ repertoire would be much easier than controlling every step of modifying a sticky web. So they compared the cocoon web to one that the spiders themselves build to rest in when they are molting. It’s called a resting web. The similarities were striking. In both the resting and cocoon webs, the sticky, spiraling threads that make the webs of orb weavers so appealing were gone. Instead, the spokes of the web remained, decorated with fibrous spider silk that the researchers found reflected ultraviolet light. That would be a highly useful quality to warn away birds and some large insects from flying into the web because those creatures can see in the ultraviolet spectrum. The strength of the two silk webs was also similar. © 2015 The New York Times Company

Keyword: Miscellaneous; Evolution
Link ID: 21403 - Posted: 09.14.2015

By Elizabeth Landau Ask a physician what the hormone vasopressin is good for, and she will explain that it regulates the volume of water in your body and also affects blood pressure. But since the 1990s, vasopressin has been a hot topic in a very different field: social behavior. And recently it has emerged as a possible target for treating autism spectrum disorders (ASD), which are characterized by social, behavioral and communication impairments. The research is still in early stages, however, and has yielded more questions than answers. Given that one out of 68 children in the U.S. has an autism spectrum disorder, researchers are scrambling to figure out what in the brain might be related to the symptoms, and how they might design an effective treatment. Vasopressin may be a key player in the disorder. But scientists do not yet know whether too much or too little of the hormone—or perhaps some combination of both—is tied to autism. New clinical trials may yield insights. “I think that the work is exciting and important” says Suma Jacob, who leads an autism research laboratory at the University of Minnesota. “I also think we still have a lot more work to do in this field as a whole.” Previous research has shown that vasopressin, like the hormone oxytocin, is associated with parenting behavior and social bonding, including falling in love. In fact, the two hormones are structurally very similar, and there are receptors in the brain that interact with both of them. But high levels of vasopressin are also associated with anxiety and aggression. Intriguingly, some animal studies have found that higher levels of vasopressin increased aggression specifically in males. © 2015 Scientific American

Keyword: Autism; Hormones & Behavior
Link ID: 21402 - Posted: 09.12.2015

Mo Costandi At some point back in deep time, a group of fish were washed into a limestone cave somewhere in northeastern Mexico. With no way out and little more than bat droppings to eat, the fish began to adapt to their new troglodytic lifestyle. Unable to see other members of their group in the dark, they lost their colourful pigmentation. Then they lost their eyesight, their eyes gradually got smaller, and then disappeared altogether. This was accompanied by a dramatic reduction in the size of the brain’s visual system. Yet, the question of why the blind cave fish lost its eyes and a large part of its brain remains unresolved. Now, biologists in Sweden believe they have found the answer. In new research published today, they report that loss of the visual system saves the fish a substantial amount of energy, and was probably key to their stranded ancestors’ survival. The blind cave fish Astyanax mexicanus is adapted to its subterranean environment in other ways. As its vision regressed, it became more reliant on smell and taste, and its taste buds grew larger and more numerous. They also developed an enhanced ability to detect changes in mechanical pressure, which made them more sensitive to water movements. Last year, Damian Moran of Lund University and his colleagues reported that blind cave fish eliminated the circadian rhythm in their metabolism during their course of evolution, and that this leads to a massive 27% reduction in their energy expenditure. This new study was designed test whether or not they lost their visual system for the same reason. © 2015 Guardian News and Media Limited

Keyword: Evolution; Vision
Link ID: 21401 - Posted: 09.12.2015

Eating two and a half times more than you should will leave you overweight and prone to type 2 diabetes, although no one is entirely sure why. Now a team that fed volunteers a whopping 6000 calories a day have found some clues. Obesity is only one problem caused by eating too much. An overly large food intake can also increase a person’s risk of diabetes, heart disease and some cancers, but no one is sure why this should be the case. Resistance to the hormone insulin seems to play a role. When a healthy person eats a meal, their blood glucose levels rise, and the body responds by making insulin. This hormone prompts the body to store un-needed glucose, but people who develop insulin resistance are not able to absorb excess glucose in the same way. This means that, after eating, their blood glucose levels remain high, and over time, this can damage the kidneys, nervous system and heart, for example. Guenther Boden and Salim Merali at Temple University, Philadelphia, and their team set out to investigate how overeating might lead to insulin resistance. They fed six healthy male volunteers 6000 calories’ worth of food every day for a week – around two and a half times what they should have been eating. “It was a regular, American diet, composed of pizzas, hamburgers and that sort of thing,” says Merali. Each volunteer stayed at a hospital for the duration of the experiment, where they were bed-bound, carefully monitored and prevented from doing any sort of exercise. © Copyright Reed Business Information Ltd.

Keyword: Obesity
Link ID: 21400 - Posted: 09.12.2015

By Sarah Schwartz Darkness and light may help prevent multiple sclerosis or fend off its symptoms. People who genetically produce less vitamin D, a compound normally boosted by sun exposure, have a greater risk of multiple sclerosis, researchers find. But the hormone melatonin, which the body produces in response to darkness, may reduce flare-ups for people who have the disease, another team of scientists reports. The studies may help researchers better understand and treat multiple sclerosis, a disease of the nervous system. It causes symptoms including muscle weakness, pain and vision loss in over 2 million people worldwide. Previous studies linked lower vitamin D levels to higher multiple sclerosis risk, but it was unclear whether this relationship was a coincidence. In work appearing August 25 in PLOS Medicine, scientists examined genetic data from thousands of Europeans and found that three genetic changes known to reduce vitamin D levels were associated with increased multiple sclerosis risk. These findings suggest that individuals with a higher risk of developing the disease, such as immediate family members of multiple sclerosis patients, should take steps to ensure they have sufficient levels of vitamin D, says study coauthor Brent Richards, a genetic epidemiologist at McGill University in Montreal. People can raise vitamin D levels to normal by taking an oral supplement. © Society for Science & the Public 2000 - 2015.

Keyword: Multiple Sclerosis; Biological Rhythms
Link ID: 21399 - Posted: 09.11.2015

Ever waited for a bus rather than take the short walk to work? Headed for the escalator instead of the stairs? Humans clearly harbour a deep love of lethargy – and now we know how far people will go to expend less energy. We will change our walking style on the fly when our normal gait becomes even a little more difficult. The finding could have implications for the rehabilitation offered to people with spinal injuries. Jessica Selinger and her colleagues at Simon Fraser University in Burnaby, British Columbia, Canada, strapped volunteers into a lightweight robotic exoskeleton and put them on a treadmill. Initially, the team let the volunteers find their preferred walking rhythm – which turned out to be 1.8 steps per second, on average. Then the researchers switched on the exoskeleton, programming it to make it more difficult for the volunteers to walk at their preferred pace by preventing the knee from bending – and leg swinging – as freely. The exoskeleton didn’t interfere with the human guinea pigs’ ability to walk faster or slower than they preferred. Within minutes the volunteers had found a walking style that the exoskeleton would allow without offering resistance. Remarkably, though, they did so despite the fact that the exoskeleton only ever offered minimal resistance. By using breathing masks to analyse the volunteers’ metabolic activity, Selinger’s team found that subjects would shift to an awkward new gait even if the energy saving was only 5 per cent. “People are able to adapt and fine-tune in order to move in the most energetically optimal way,” says Selinger. “People will change really fundamental characteristics of their gait.” © Copyright Reed Business Information Ltd.

Keyword: Movement Disorders
Link ID: 21398 - Posted: 09.11.2015

Neel V. Patel The concept of the insanity defense dates back to ancient Greece and the Roman Empire. The idea has always been the same: Protect individuals from being held accountable for behavior they couldn’t control. Yet there have been more than a few historical and recent instances of a judge or jury issuing a controversial “by reason of…” verdict. What was intended as a human rights effort has become a last-ditch way to save killers (though it didn’t work for James Holmes). The question that hangs in the air at these sort of proceedings has always been the same: Is there a way to make determinations more scientific and less traditionally judicial? Adam Shniderman, a criminal justice researcher at Texas Christian University, has been studying the role of neuroscience in the court system for several years now. He explains that neurological data and explanations don’t easily translate into the world of lawyers and legal text. Inverse spoke with Shniderman to learn more about how neuroscience is used in today’s insanity defenses, and whether this is likely to change as the technology used to observe the brain gets better and better. Can you give me a quick overview of how the role of neuroscience in the courts, has changed over the years? Especially in the last few decades with new advances in technology. Obviously, [neuroscientific evidence] has become more widely used as brain-scanning technology has gotten better. Some of the scanning technology we use now, like functional MRI that measures blood oxygenation as a proxy for neurological activity, is relatively new within the last 20 years or so. The nature of brain scanning has changed, but the knowledge that the brain influences someone’s actions is not new.

Keyword: Consciousness; Schizophrenia
Link ID: 21397 - Posted: 09.11.2015

By JOHN NOBLE WILFORD Acting on a tip from spelunkers two years ago, scientists in South Africa discovered what the cavers had only dimly glimpsed through a crack in a limestone wall deep in the Rising Star Cave: lots and lots of old bones. The remains covered the earthen floor beyond the narrow opening. This was, the scientists concluded, a large, dark chamber for the dead of a previously unidentified species of the early human lineage — Homo naledi. The new hominin species was announced on Thursday by an international team of more than 60 scientists led by Lee R. Berger, an American paleoanthropologist who is a professor of human evolution studies at the University of the Witwatersrand in Johannesburg. The species name, H. naledi, refers to the cave where the bones lay undisturbed for so long; “naledi” means “star” in the local Sesotho language. In two papers published this week in the open-access journal eLife, the researchers said that the more than 1,550 fossil elements documenting the discovery constituted the largest sample for any hominin species in a single African site, and one of the largest anywhere in the world. Further, the scientists said, that sample is probably a small fraction of the fossils yet to be recovered from the chamber. So far the team has recovered parts of at least 15 individuals. “With almost every bone in the body represented multiple times, Homo naledi is already practically the best-known fossil member of our lineage,” Dr. Berger said. The finding, like so many others in science, was the result of pure luck followed by considerable effort. Two local cavers, Rick Hunter and Steven Tucker, found the narrow entrance to the chamber, measuring no more than seven and a half inches wide. They were skinny enough to squeeze through, and in the light of their headlamps they saw the bones all around them. When they showed the fossil pictures to Pedro Boshoff, a caver who is also a geologist, he alerted Dr. Berger, who organized an investigation. © 2015 The New York Times Company

Keyword: Evolution
Link ID: 21396 - Posted: 09.11.2015

Alison Abbott Only a decade ago, the idea that Alzheimer’s disease might be transmissible between people would have been laughed off the stage. But scientists have since shown that tissues can transmit symptoms of the disease between animals — and new results imply that humans, at least in one unusual circumstance, may not be an exception. The findings, published in this issue of Nature, emerged during autopsy studies of the brains of eight people who had died of the rare but deadly Creutzfeldt–Jakob disease (CJD; Z. Jaunmuktane et al. Nature 525, 247–250; 2015). They contracted it decades after treatment with contaminated batches of growth hormone that had been extracted from the pituitary glands of human cadavers. Six of the brains, in addition to the damage caused by CJD, harboured the tell-tale amyloid pathology that is associated with Alzheimer’s disease. “This is the first evidence of real-world transmission of amyloid pathology,” says molecular neuroscientist John Hardy of University College London (UCL). “It is potentially concerning.” If confirmed, the findings raise the spectre that tens of thousands of other people treated with the human growth-hormone (hGH) extracts might be at risk of Alzheimer’s. And although there is no suggestion that Alzheimer’s could be contracted through normal contact with patients, some scientists worry that the findings may have broader implications: that Alzheimer’s could be passed on by other routes through which CJD can be transmitted, such as blood transfusions or contaminated surgical instruments. © 2015 Nature Publishing Group

Keyword: Alzheimers; Prions
Link ID: 21395 - Posted: 09.10.2015

Bill McQuay and Christopher Joyce Acoustic biologists who have learned to tune their ears to the sounds of life know there's a lot more to animal communication than just, "Hey, here I am!" or "I need a mate." From insects to elephants to people, we animals all use sound to function and converse in social groups — especially when the environment is dark, or underwater or heavily forested. "We think that we really know what's going on out there," says Dartmouth College biologist Laurel Symes, who studies crickets. But there's a cacophony all around us, she says, that's full of information still to be deciphered. "We're getting this tiny slice of all of the sound in the world." Recently scientists have pushed the field of bioacoustics even further, to record whole environments, not just the animals that live there. Some call this "acoustic ecology" — listening to the rain, streams, wind through the trees. A deciduous forest sounds different from a pine forest, for example, and that soundscape changes seasonally. Neuroscientist Seth Horowitz, author of the book The Universal Sense: How Hearing Shapes the Mind, is especially interested in the ways all these sounds, which are essentially vibrations, have shaped the evolution of the human brain. "Vibration sensitivity is found in even the most primitive life forms," Horowitz says — even bacteria. "It's so critical to your environment, knowing that something else is moving near you, whether it's a predator or it's food. Everywhere you go there is vibration and it tells you something." © 2015 NPR

Keyword: Hearing; Evolution
Link ID: 21394 - Posted: 09.10.2015