Chapter 16. None

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By JAMES GORMAN Bees find nectar and tell their hive-mates; flies evade the swatter; and cockroaches seem to do whatever they like wherever they like. But who would believe that insects are conscious, that they are aware of what’s going on, not just little biobots? Neuroscientists and philosophers apparently. As scientists lean increasingly toward recognizing that nonhuman animals are conscious in one way or another, the question becomes: Where does consciousness end? Andrew B. Barron, a cognitive scientist, and Colin Klein, a philosopher, at Macquarie University in Sydney, Australia, propose in Proceedings of the National Academy of Sciences that insects have the capacity for consciousness. This does not mean that a honeybee thinks, “Why am I not the queen?” or even, “Oh, I like that nectar.” But, Dr. Barron and Dr. Klein wrote in a scientific essay, the honeybee has the capacity to feel something. Their claim stops short of some others. Christof Koch, the president and chief scientific officer of the Allen Institute for Brain Science in Seattle, and Giulio Tononi, a neuroscientist and psychiatrist at the University of Wisconsin, have proposed that consciousness is nearly ubiquitous in different degrees, and can be present even in nonliving arrangements of matter, to varying degrees. They say that rather than wonder how consciousness arises, one should look at where we know it exists and go from there to where else it might exist. They conclude that it is an inherent property of physical systems in which information moves around in a certain way — and that could include some kinds of artificial intelligence and even naturally occurring nonliving matter. © 2016 The New York Times Company

Keyword: Consciousness
Link ID: 22118 - Posted: 04.19.2016

Rachel Becker A highly contagious and deadly animal brain disorder has been detected in Europe for the first time. Scientists are now warning that the single case found in a wild reindeer might represent an unrecognized, widespread infection. Chronic wasting disease (CWD) was thought to be restricted to deer, elk (Cervus canadensis) and moose (Alces alces) in North America and South Korea, but on 4 April researchers announced that the disease had been discovered in a free-ranging reindeer (Rangifer tarandus tarandus) in Norway. This is both the first time that CWD has been found in Europe and the first time that it has been found in this species in the wild anywhere in the world. “It’s worrying — of course, especially for animals. It’s a nasty disease,” says Sylvie Benestad, an animal-disease researcher at the Norwegian Veterinary Institute in Oslo who, along with colleague Turid Vikøren, diagnosed the diseased reindeer. A key question now is whether this is a rare — even unique — case, or if the disease is widespread but so far undetected in Europe. “If it’s similar to our prion disease in the United States and Canada, the disease is subtle and it would be easy to miss,” says Christina Sigurdson, a pathologist at the University of California, San Diego, who has shown that reindeer can contract CWD in a laboratory environment1. © 2016 Nature Publishing Group,

Keyword: Prions
Link ID: 22117 - Posted: 04.19.2016

Scientists believe injections of a natural protein may lessen the symptoms and progress of Alzheimer's dementia after promising early trials in mice. The treatment - IL 33 - appeared to improve memory and help clear and prevent brain deposits similar to those seen in people with Alzheimer's. Tentative human studies of the treatment will soon begin, but experts say it will take many years to know if it could help patients in real life. The work is published in PNAS journal. Interleukin 33, or IL 33 for short, is made by the body as part of its immune defence against infection and disease, particularly within the brain and spinal cord. And patients with Alzheimer's have been found to have lower amounts of IL 33 in their brains than healthy adults. The researchers from the University of Glasgow and the Hong Kong University of Science and Technology tested what effect a boost of IL 33 might have on mice bred to have brain changes akin to Alzheimer's. The rodents rapidly improved their memory and cognitive function to that of the age-matched normal mice within a week of having the injections. Prof Eddy Liew, who led the work at the University of Glasgow, is excited but cautious about his findings. "Exciting as it is, there is some distance between laboratory findings and clinical applications. There have been enough false 'breakthroughs' in the medical field to caution us not to hold our breath until rigorous clinical trials have been done." © 2016 BBC.

Keyword: Alzheimers
Link ID: 22115 - Posted: 04.19.2016

By Jillian Bell, CBC News New medical marijuana products produced by yeast could soon be on the market, the co-founder of a biotech company says. That could potentially lead to a wider range of cannabinoid-based drugs that proponents say could be more effective for treating certain medical conditions than medical marijuana itself. The appropriate use of medical marijuana has been a controversial topic, with many arguing that further research is needed to evaluate its efficacy as a treatment for a variety of ailments. In Canada, where the Liberal government has said it will legalize marijuana, medical marijuana is already used to treat a variety of conditions and symptoms, including lack of appetite in people with HIV/AIDS and nausea in those undergoing cancer treatment. The most well-known cannabinoid is tetrahydrolcannabinol, or THC, which is approved by the U.S. Food and Drug Administration to treat nausea and improve appetite. It's found in large amounts in marijuana plants, which is the reason why medical marijuana is often prescribed to treat nausea and increase appetite. But other cannabinoids, like cannabidiol (CBD) and cannabigerol (CBG) may have the potential to be potent treatments for other conditions as well. CBG also has its own medical properties. But it can also be easily chemically converted into other cannabinoids, including THC. ©2016 CBC/Radio-Canada.

Keyword: Drug Abuse
Link ID: 22111 - Posted: 04.18.2016

By David Shultz Mice supposedly don't speak, so they can't stutter. But by tinkering with a gene that appears to be involved in human speech, researchers have created transgenic mice whose pups produce altered vocalizations in a way that is similar to stuttering in humans. The mice could make a good model for understanding stuttering; they could also shed more light on how mutations in the gene, called Gnptab, cause the speech disorder. Stuttering is one of the most common speech disorders in the world, affecting nearly one out of 100 adults in the United States. But the cause of the stammering, fragmented speech patterns remains unclear. Several years ago, researchers discovered that stutterers often have mutations in a gene called Gnptab. Like a dispatcher directing garbage trucks, Gnptab encodes a protein that helps to direct enzymes into the lysosome—a compartment in animal cells that breaks down waste and recycles old cellular machinery. Mutations to other genes in this system are known to lead to the buildup of cellular waste products and often result in debilitating diseases, such as Tay-Sachs. How mutations in Gnptab causes stuttered speech remains a mystery, however. To get to the bottom of things, neuroscientist Terra Barnes and her team at Washington University in St. Louis in Missouri produced mice with mutation in the Gnptab gene and studied whether it affected the ultrasonic vocalizations that newly born mouse pups emit when separated from their mothers. Determining whether a mouse is stuttering is no easy task; as Barnes points out, it can even be difficult to tell whether people are stuttering if they’re speaking a foreign language. So the team designed a computer program that listens for stuttering vocalization patterns independent of language. © 2016 American Association for the Advancement of Science.

Keyword: Language
Link ID: 22110 - Posted: 04.16.2016

By Matthew Hutson Bad news for believers in clairvoyance. Our brains appear to rewrite history so that the choices we make after an event seem to precede it. In other words, we add loops to our mental timeline that let us feel we can predict things that in reality have already happened. Adam Bear and Paul Bloom at Yale University conducted some simple tests on volunteers. In one experiment, subjects looked at white circles and silently guessed which one would turn red. Once one circle had changed colour, they reported whether or not they had predicted correctly. Over many trials, their reported accuracy was significantly better than the 20 per cent expected by chance, indicating that the volunteers either had psychic abilities or had unwittingly played a mental trick on themselves. The researchers’ study design helped explain what was really going on. They placed different delays between the white circles’ appearance and one of the circles turning red, ranging from 50 milliseconds to one second. Participants’ reported accuracy was highest – surpassing 30 per cent – when the delays were shortest. That’s what you would expect if the appearance of the red circle was actually influencing decisions still in progress. This suggests it’s unlikely that the subjects were merely lying about their predictive abilities to impress the researchers. The mechanism behind this behaviour is still unclear. It’s possible, the researchers suggest, that we perceive the order of events correctly – one circle changes colour before we have actually made our prediction – but then we subconsciously swap the sequence in our memories so the prediction seems to come first. Such a switcheroo could be motivated by a desire to feel in control of our lives. © Copyright Reed Business Information Ltd.

Keyword: Consciousness
Link ID: 22109 - Posted: 04.16.2016

By Robin Wylie Bottlenose dolphins have been observed chattering while cooperating to solve a tricky puzzle – a feat that suggests they have a type of vocalisation dedicated to cooperating on problem solving. Holli Eskelinen of Dolphins Plus research institute in Florida and her colleagues at the University of Southern Mississippi presented a group of six captive dolphins with a locked canister filled with food. The canister could only be opened by simultaneously pulling on a rope at either end. The team conducted 24 canister trials, during which all six dolphins were present. Only two of the dolphins ever managed to crack the puzzle and get to the food. The successful pair was prolific, though: in 20 of the trials, the same two adult males worked together to open the food canister in a matter of few minutes. In the other four trials, one of the dolphins managed to solve the problem on its own, but this was much trickier and took longer to execute. But the real surprise came from recordings of the vocalisations the dolphins made during the experiment. The team found that when the dolphins worked together to open the canister, they made around three times more vocalisations than they did while opening the canister on their own or when there was either no canister present or no interaction with the canister in the pool. © Copyright Reed Business Information Ltd.

Keyword: Language; Evolution
Link ID: 22107 - Posted: 04.16.2016

By BENEDICT CAREY Five years ago, a college freshman named Ian Burkhart dived into a wave at a beach off the Outer Banks in North Carolina and, in a freakish accident, broke his neck on the sandy floor, permanently losing the feeling in his hands and legs. On Wednesday, doctors reported that Mr. Burkhart, 24, had regained control over his right hand and fingers, using technology that transmits his thoughts directly to his hand muscles and bypasses his spinal injury. The doctors’ study, published by the journal Nature, is the first account of limb reanimation, as it is known, in a person with quadriplegia. Doctors implanted a chip in Mr. Burkhart’s brain two years ago. Seated in a lab with the implant connected through a computer to a sleeve on his arm, he was able to learn by repetition and arduous practice to focus his thoughts to make his hand pour from a bottle, and to pick up a straw and stir. He was even able to play a guitar video game. “It’s crazy because I had lost sensation in my hands, and I had to watch my hand to know whether I was squeezing or extending the fingers,” Mr. Burkhart, a business student who lives in Dublin, Ohio, said in an interview. His injury had left him paralyzed from the chest down; he still has some movement in his shoulders and biceps. The new technology is not a cure for paralysis. Mr. Burkhart could use his hand only when connected to computers in the lab, and the researchers said there was much work to do before the system could provide significant mobile independence. But the field of neural engineering is advancing quickly. Using brain implants, scientists can decode brain signals and match them to specific movements. Previously, people have learned to guide a cursor on a screen with their thoughts, monkeys have learned to skillfully use a robotic arm through neural signals and scientists have taught monkeys who were partly paralyzed to use an arm with a bypass system. This new study demonstrates that the bypass approach can restore critical skills to limbs no longer directly connected to the brain. © 2016 The New York Times Company

Keyword: Robotics
Link ID: 22106 - Posted: 04.14.2016

By Amy Ellis Nutt I saw it all: The beginning of Time and the end of Time. Creation and annihilation. Somehow I’d slipped through a seam in the space-time continuum, and from my privileged mental perch I'd peered into the center of the universe. I was exhilarated and drew diagrams of my visions, trying to figure out what it all meant. But when I shared those visions with friends, they were confused and concerned. I was manic, they said, and making no sense. We were at an impasse. Was I sick – or simply in search of myself? Those questions from my own past hovered in the background while I watched two very different documentaries recently. Both explore bipolar illness -- a diagnosis I received more than 25 years ago and one that 5.5 million Americans share. But the films come from very different perspectives. The first, "Ride the Tiger: A Guide Through the Bipolar Brain," was produced by Detroit Public TV and airs on PBS Wednesday. It chronicles the latest in cutting-edge research into bipolar disorder and in doing so firmly plants its flag in the biological camp: The disorder is about misfiring brain circuits, genetic mutations, neurochemical disruptions and other neurological processes not yet delineated. The result is dramatic swings in mood and behavior that affect a person's ability to think clearly. "Ride the Tiger" features appearances by former congressman Patrick Kennedy and the late actress Patty Duke, both of whom talk about their own experiences. The second documentary, "Bipolarized: Re-Thinking Mental Illness," questions the very reality of the disorder -- at least for one former psychiatric patient.

Keyword: Schizophrenia
Link ID: 22104 - Posted: 04.14.2016

Eleanor Ainge Roy in Dunedin An octopus has made a brazen escape from the national aquarium in New Zealand by breaking out of its tank, slithering down a 50-metre drainpipe and disappearing into the sea. In scenes reminiscent of Finding Nemo, Inky – a common New Zealand octopus – made his dash for freedom after the lid of his tank was accidentally left slightly ajar. Staff believe that in the middle of the night, while the aquarium was deserted, Inky clambered to the top of his cage, down the side of the tank and travelled across the floor of the aquarium. Rob Yarrell, national manager of the National Aquarium of New Zealand in Napier, said: “Octopuses are famous escape artists. “But Inky really tested the waters here. I don’t think he was unhappy with us, or lonely, as octopus are solitary creatures. But he is such a curious boy. He would want to know what’s happening on the outside. That’s just his personality.” One theory is that Inky slid across the aquarium floor – a journey of three or four metres – and then, sensing freedom was at hand, into a drainpipe that lead directly to the sea. The drainpipe was 50 metres long, and opened on to the waters of Hawke’s Bay, on the east coast of New Zealand’s North Island. Another possible escape route could have involved Inky squeezing into an open pipe at the top of his tank, which led under the floor to the drain. © 2016 Guardian News and Media Limited

Keyword: Intelligence; Evolution
Link ID: 22103 - Posted: 04.14.2016

By Gareth Cook What are the most intelligent creatures on the planet? Humans come first. (Though there are days when we have to wonder.) After Homo sapiens, most people might answer chimpanzees, and then maybe dogs and dolphins. But what of birds? The science writer Jennifer Ackerman offers a lyrical testimony to the wonders of avian intelligence in her new book, “The Genius of Birds.” There have long been hints of bird smarts, but it’s become an active field of scientific inquiry, and Ackerman serves as tour guide. She answered questions from Mind Matters editor Gareth Cook. What drew you to birds? I’ve watched birds for most of my life. I admire all the usual things about them. Their plumage and song. Their intense way of living. Their flight. I also admire their resourcefulness and pluck. I’ve always been intrigued by their apparently smart behavior, whether learned or innate. I grew up in Washington, D.C. — the second youngest in a gaggle of five girls. My parents had precious little time for one-on-one. Especially my dad, who had a demanding government job. So when he asked me if I wanted to go birdwatching with him one spring morning when I was seven or eight, I jumped at the chance. It was magical, going out in the dark woods along the C&O canal and listening for bird song. My father had learned his calls and songs in Boy Scout camp from an expert, an elderly Greek man named Apollo, so he was pretty good at identifying birds, even the shy woodland species. Eventually he gave me my own copy of Peterson’s Field Guide, along with a small pair of binoculars. I’ve loved birds ever since. My first run in with a clever bird was on our dining room table. We had a pet parakeet, a budgerigar named Gre-Gre, who was allowed to fly around the dining room and perch on our head or shoulders. He had a kind of social genius. He made you love him. But at breakfast, it was impossible to eat your cereal without his constant harassment. He liked to perch on the edge of my bowl and peck at the cereal, flapping his wings frantically to keep his balance, splashing my milk. I’d build a barricade of boxes around my place setting, but he always found a way in, moving a box or popping over the top. He was a good problem-solver. © 2016 Scientific American

Keyword: Intelligence; Evolution
Link ID: 22101 - Posted: 04.13.2016

By Virginia Morell Moths have an almost fatal attraction to lights—so much so that we say people are drawn to bad ends “like moths to a flame.” But in this age of global light pollution, that saying has a new poignancy: Moths, which are typically nocturnal insects, are dying in droves at artificial lights. The high levels of mortality should have evolutionary consequences, leading to moths that avoid lights, biologists say. To find out, two scientists tested the flight-to-light behavior of 1048 adult ermine moths (Yponomeuta cagnagella, shown above) in Europe. The researchers collected the insects in 2007 as larvae that had just completed their first molt. Three hundred and twenty came from populations that lived where the skies were largely dark; 728 were gathered in light polluted areas. They were raised in a lab with 16 hours of daylight and 8 hours of darkness daily while they completed their life stages. Two to 3 days after emerging as moths, they were released in a flight cage with a fluorescent tube at one side. Moths from high light pollution areas were significantly less attracted to the light than those from the darker zones, the scientists report in today’s issue of Biology Letters. Overall, moths from the light-polluted populations had a 30% reduction in the flight-to-light behavior, indicating that this species is evolving, as predicted, to stay away from artificial lights. That change should increase these city moths’ reproductive success. But their success comes at a cost: To avoid the lights, the moths are likely flying less, say the scientists, so they aren’t pollinating as many flowers or feeding as many spiders and bats. © 2016 American Association for the Advancement of Science.

Keyword: Evolution
Link ID: 22100 - Posted: 04.13.2016

Sam Doernberg and Joe DiPietro It’s the first day of class, and we—a couple of instructors from Cornell—sit around a table with a few of our students as the rest trickle in. Anderson, one of the students seated across from us, smiles and says, “I’m going to get an A+ in your class.” “No,” VanAntwerp retorts, “I’m getting the A+.” You might think that this scene is typical of classes at a school like Cornell University, where driven students compete for top marks. But this didn’t happen on a college campus: It took place in a maximum-security prison. To the outside world, they are inmates, but in the classroom, they are students enrolled in the Cornell Prison Education Program, or “CPEP.” Per New York State Department of Corrections rules, we have permission to use the inmates’ last names only—which is also often how we know them best. Those who graduate from the program—taught by Cornell instructors—will receive an associate’s degree from Cayuga Community College. Before teaching neuroscience to prison inmates, we taught it to Cornell undergraduates as part of the teaching staff for Cornell’s Introduction to Neuroscience course. Most Cornell neuroscience students are high-achieving biology majors and premeds, who are well prepared to succeed in a demanding course. They generally have gone from one academic success to another, and it is no secret that they expect a similar level of success in a neuroscience class. © 2016 by The Atlantic Monthly Group

Keyword: Learning & Memory
Link ID: 22093 - Posted: 04.12.2016

By FRANS de WAAL TICKLING a juvenile chimpanzee is a lot like tickling a child. The ape has the same sensitive spots: under the armpits, on the side, in the belly. He opens his mouth wide, lips relaxed, panting audibly in the same “huh-huh-huh” rhythm of inhalation and exhalation as human laughter. The similarity makes it hard not to giggle yourself. The ape also shows the same ambivalence as a child. He pushes your tickling fingers away and tries to escape, but as soon as you stop he comes back for more, putting his belly right in front of you. At this point, you need only to point to a tickling spot, not even touching it, and he will throw another fit of laughter. Laughter? Now wait a minute! A real scientist should avoid any and all anthropomorphism, which is why hard-nosed colleagues often ask us to change our terminology. Why not call the ape’s reaction something neutral, like, say, vocalized panting? That way we avoid confusion between the human and the animal. The term anthropomorphism, which means “human form,” comes from the Greek philosopher Xenophanes, who protested in the fifth century B.C. against Homer’s poetry because it described the gods as though they looked human. Xenophanes mocked this assumption, reportedly saying that if horses had hands they would “draw their gods like horses.” Nowadays the term has a broader meaning. It is typically used to censure the attribution of humanlike traits and experiences to other species. Animals don’t have “sex,” but engage in breeding behavior. They don’t have “friends,” but favorite affiliation partners. Given how partial our species is to intellectual distinctions, we apply such linguistic castrations even more vigorously in the cognitive domain. By explaining the smartness of animals either as a product of instinct or simple learning, we have kept human cognition on its pedestal under the guise of being scientific. Everything boiled down to genes and reinforcement. To think otherwise opened you up to ridicule, which is what happened to Wolfgang Köhler, the German psychologist who, a century ago, was the first to demonstrate flashes of insight in chimpanzees. © 2016 The New York Times Company

Keyword: Evolution; Emotions
Link ID: 22091 - Posted: 04.11.2016

By Neuroskeptic Do you want to be more successful? Happier? More intelligent? Don’t despair. The answer, we’re told, is right in front of your nose—or rather, right behind it. It’s your own brain. Thanks to neuroscience, you can hack your gray matter. According to the sales pitch, almost anything is possible, if you can master your brain—and if you can afford to buy the products that promise to help you do that. But how many of these neuroproducts are neurobullshit? And what makes neuroscience so attractive to people with something to sell? I’m a neuroscientist who has been blogging about the brain for the past eight years. Over this time I’ve noticed a steady increase in the number of neuroscience-themed commercial products. There are brain pills to optimize your mental focus. There are futuristic-looking headbands that promise to measure or stimulate your neural activity in order to make you smarter, or help you sleep better, or even meditate better. There is no end of “brain training” apps and neuroscience-themed self-help books. These products tend to have names based around “Neuro” or “Brain.” And they will come advertised as being “created by neuroscientists,” “based on the latest brain research,” or at least endorsed by some leading brain expert. Once you look beyond the “neuro” gloss, however, you’ll see that many of these products aren’t new at all, but just old products in new packaging. A recent, and notorious, example of this was “Fifth Quarter Fresh,” a brand of chocolate milk.

Keyword: Miscellaneous
Link ID: 22090 - Posted: 04.11.2016

Carl Zimmer Five days a week, you can tune into “Paternity Court,” a television show featuring couples embroiled in disputes over fatherhood. It’s entertainment with a very old theme: Uncertainty over paternity goes back a long way in literature. Even Shakespeare and Chaucer cracked wise about cuckolds, who were often depicted wearing horns. But in a number of recent studies, researchers have found that our obsession with cuckolded fathers is seriously overblown. A number of recent genetic studies challenge the notion that mistaken paternity is commonplace. “It’s absolutely ridiculous,” said Maarten H.D. Larmuseau, a geneticist at the University of Leuven in Belgium who has led much of this new research. The term cuckold traditionally refers to the husband of an adulteress, but Dr. Larmuseau and other researchers focus on those cases that produce a child, which scientists politely call “extra-pair paternity.” Until the 20th century, it was difficult to prove that a particular man was the biological father of a particular child. In 1304 a British husband went to court to dispute the paternity of his wife’s child, born while he was abroad for three years. Despite the obvious logistical challenges, the court rejected the husband’s objection. “The privity between a man and his wife cannot be known,” the judge ruled. Modern biology lifted the veil from this mystery, albeit slowly. In the early 1900s, researchers discovered that people have distinct blood types inherited from their parents. In a 1943 lawsuit, Charlie Chaplin relied on blood-type testing to prove that he was not the father of the actress Joan Barry’s child. (The court refused to accept the evidence and forced Chaplin to pay child support anyway.) © 2016 The New York Times Company

Keyword: Sexual Behavior
Link ID: 22089 - Posted: 04.09.2016

Modern humans diverged from Neanderthals some 600,000 years ago – and a new study shows the Y chromosome might be what kept the two species separate. It seems we were genetically incompatible with our ancient relatives – and male fetuses conceived through sex with Neanderthal males would have miscarried. We knew that some cross-breeding between us and Neanderthals happened more recently – around 100,000 to 60,000 years ago. Neanderthal genes have been found in our genomes, on X chromosomes, and have been linked to traits such as skin colour, fertility and even depression and addiction. Now, an analysis of a Y chromosome from a 49,000-year-old male Neanderthal found in El Sidrón, Spain, suggests the chromosome has gone extinct seemingly without leaving any trace in modern humans. This could simply be because it drifted out of the human gene pool or, as the new study suggests, it could be because genetic differences meant that hybrid offspring who had this chromosome were infertile – a genetic dead end. Fernando Mendez of Stanford University, and his colleagues compared the Neanderthal Y chromosome with that of chimps, and ancient and modern humans. They found mutations in four genes that could have prevented the passage of Y chromosome down the paternal line to the hybrid children. “Some of these mutations could have played a role in the loss of Neanderthal Y chromosomes in human populations,” says Mendez. © Copyright Reed Business Information Ltd.

Keyword: Evolution; Sexual Behavior
Link ID: 22088 - Posted: 04.09.2016

For decades, it was thought that scar-forming cells called astrocytes were responsible for blocking neuronal regrowth across the level of spinal cord injury, but recent findings challenge this idea. According to a new mouse study, astrocyte scars may actually be required for repair and regrowth following spinal cord injury. The research was funded by the National Institutes of Health, and published in Nature. “At first, we were completely surprised when our early studies revealed that blocking scar formation after injury resulted in worse outcomes. Once we began looking specifically at regrowth, though, we became convinced that scars may actually be beneficial,” said Michael V. Sofroniew, M.D., Ph.D., professor of neurobiology at the University of California, Los Angeles, and senior author of the study. “Our results suggest that scars may be a bridge and not a barrier towards developing better treatments for paralyzing spinal cord injuries.” Neurons communicate with one another by sending messages down long extensions called axons. When axons in the brain or spinal cord are severed, they do not grow back automatically. For example, damaged axons in the spinal cord can result in paralysis. When an injury occurs, astrocytes become activated and go to the injury site, along with cells from the immune system and form a scar. Scars have immediate benefits by decreasing inflammation at the injury site and preventing spread of tissue damage. However, long-term effects of the scars were thought to interfere with axon regrowth.

Keyword: Regeneration; Glia
Link ID: 22086 - Posted: 04.09.2016

By Catherine Matacic How does sign language develop? A new study shows that it takes less than five generations for people to go from simple, unconventional pantomimes—essentially telling a story with your hands—to stable signs. Researchers asked a group of volunteers to invent their own signs for a set of 24 words in four separate categories: people, locations, objects, and actions. Examples included “photographer,” “darkroom,” and “camera.” After an initial group made up the signs—pretending to shoot a picture with an old-fashioned camera for “photographer,” for example—they taught the signs to a new generation of learners. That generation then played a game where they tried to guess what sign another player in their group was making. When they got the answer right, they taught that sign to a new generation of volunteers. After a few generations, the volunteers stopped acting out the words with inconsistent gestures and started making them in ways that were more systematic and efficient. What’s more, they added markers for the four categories—pointing to themselves if the category were “person” or making the outline of a house if the category were “location,” for example—and they stopped repeating gestures, the researchers reported last month at the Evolution of Language conference in New Orleans, Louisiana. So in the video above, the first version of “photographer” is unpredictable and long, compared with the final version, which uses the person marker and takes just half the time. The researchers say their finding supports the work of researchers in the field, who have found similar patterns of development in newly emerging sign languages. The results also suggest that learning and social interaction are crucial to this development. © 2016 American Association for the Advancement of Science

Keyword: Language
Link ID: 22084 - Posted: 04.09.2016

JUST say no. That’s supposed to be our reaction to recreational drugs. The trouble is, lots of people say yes please. As a result, the world’s governments have been waging a war on drugs for more than a century. Since 1961, the battle has been orchestrated via international treaties targeting all parts of the supply chain, from the producers to the smugglers, the sellers to the buyers. Yet this supposedly united front has developed some conspicuous cracks. Now those countries backing a different approach have called a UN meeting later this month to make the case for change. The question is whether the UN is ready to soften its stance or whether it will plough on despite mountains of evidence suggesting its zero-tolerance approach has failed. As the reformers collate this to present at the meeting, New Scientist looks at how the approaches taken by different countries stack up (see “Drugs around the world”, below), and asks what can happen next. Some nations are already taking change into their own hands. Portugal allows personal use of any drug – including cocaine and heroin – and several South and Central American countries are moving in the same direction. As for cannabis, the number of places where its open sale has been decriminalised in some form grows ever larger. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse
Link ID: 22082 - Posted: 04.07.2016