Chapter 16. None
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By SABRINA TAVERNISE WASHINGTON — The global diabetes rate has risen by nearly half over the past two decades, according to a new study, as obesity and the health problems it spawns have taken hold across the developing world. The prevalence of diabetes has been rising in rich countries for several decades, largely driven by increases in the rate of obesity. More recently, poorer countries have begun to follow the trend, with major increases in countries like China, Mexico and India. The study, published Monday in the British medical journal The Lancet, reported a 45 percent rise in the prevalence of diabetes worldwide from 1990 to 2013. Nearly all the rise was in Type 2, which is usually related to obesity and is the most common form of the disease. A major shift is underway in the developing world, in which deaths from communicable diseases like malaria and tuberculosis have declined sharply, and chronic diseases like cancer and diabetes are on the rise. The pattern is linked to economic improvement and more people living longer, but it has left governments in developing countries scrambling to deal with new and often more expensive ways to treat illnesses. The study, led by the Institute for Health Metrics and Evaluation, a research group, was funded by the Bill and Melinda Gates Foundation. It is the largest analysis of global disability data to date, drawing on more than 35,000 data sources in 188 countries. © 2015 The New York Times Company
Link ID: 21026 - Posted: 06.08.2015
Steve Connor Scientists have linked the condition with variations in the DNA of genes known to be involved in stimulating or inhibiting the passing of chemical messages across the tiny gaps or “synapses” between nerve cells in the brain. They said the findings are part of a wider body of evidence pointing to the genetic causes of schizophrenia which is known to have a strong inherited component as well as being influenced by a person’s environment and upbringing. “We’re finally starting to understand what goes wrong in schizophrenia. Our study marks a significant step towards understanding the biology underpinning schizophrenia, which is an incredible complex condition and has up until very recently kept scientists largely mystified as to is origins,” said Andrew Pocklington of Cardiff University. “We now have what we hope is a pretty sizeable piece of the jigsaw puzzle that will help us to develop a coherent model of the disease, while helping us to rule out some of the alternatives,” said Dr Pocklington, the lead author of the study published in the journal Neuron. “A reliable model of disease is urgently needed to direct future efforts in developing new treatments, which haven’t really improved a great deal since the 1970s,” he said. © independent.co.uk
by Clare Wilson The first drug for treating low sexual desire in women looks set to go on sale in the US next year Flibanserin, sometimes called the female Viagra, was approved by 18 votes to 6 by a US Food and Drug Administration advisory panel yesterday, although some of the committee members had doubts about the drug's risks and benefits. They required that certain "risk-management options" be put in place, on top of the usual list of side effects listed in the medicine's patient information leaflet. We have yet to hear what this means, but options include doctors having to verbally warn women not to drink alcohol or use various other medicines when taking the drug. The FDA's final say is due by August, but it usually follows the decision of its advisory panel. Assuming it gets the go-ahead, manufacturer Sprout Pharmaceuticals of Raleigh, North Carolina, plans to give the drug the brand-name Addyi, and has promised not to advertise the product directly to patients – which is normally allowed in the US – for the first 18 months it goes on sale. Addyi is no Viagra though – women would have to take it every day, whether or not they want sex. And, while the famous little blue pill works by increasing blood flow to the genitals, this new drug instead alters brain chemistry, affecting receptors for various signalling chemicals including serotonin and dopamine. © Copyright Reed Business Information Ltd.
Keyword: Sexual Behavior
Link ID: 21020 - Posted: 06.06.2015
Anthony Kulkamp Dias, a 33-year old Brazilian bank worker, performed a Beatles classic for the team of surgeons operating on his brain tumour. The video shot by one of the medical team shows Dias horizontal, strumming on a guitar and singing the Beatles’ iconic song ‘ Yesterday’. The lyrics, “yesterday, all my troubles seemed so far away…” had added pertinence considering the unique situation Dias found himself in. There was a medical explanation behind the impromptu singsong with doctors keeping Dias awake in order to conduct ‘cerebral monitoring’, which a spokesperson reportedly said is “important to prevent injuries that occur in the sensory, motor and speech areas of the brain.” Through his performance, Dias was able to provide real-time feedback about how the surgery was affecting his brain. © independent.co.uk
Link ID: 21019 - Posted: 06.06.2015
By Rachael Rettner and LiveScience Mathematician John Nash, who died May 23 in a car accident, was known for his decades-long battle with schizophrenia—a struggle famously depicted in the 2001 Oscar-winning film "A Beautiful Mind." Nash had apparently recovered from the disease later in life, which he said was done without medication. But how often do people recover from schizophrenia, and how does such a destructive disease disappear? Nash developed symptoms of schizophrenia in the late 1950s, when he was around age 30, after he made groundbreaking contributions to the field of mathematics, including the extension of game theory, or the math of decision making. He began to exhibit bizarre behavior and experience paranoia and delusions, according to The New York Times. Over the next several decades, he was hospitalized several times, and was on and off anti-psychotic medications. But in the 1980s, when Nash was in his 50s, his condition began to improve. In an email to a colleague in the mid-1990s, Nash said, "I emerged from irrational thinking, ultimately, without medicine other than the natural hormonal changes of aging," according to The New York Times. Nash and his wife Alicia died, at ages 86 and 82, respectively, in a crash on the New Jersey Turnpike while en route home from a trip on which Nash had received a prestigious award for his work. © 2015 Scientific American
Link ID: 21018 - Posted: 06.06.2015
How echolocation really works By Dwayne Godwin and Jorge Cham © 2015 Scientific American
Link ID: 21017 - Posted: 06.06.2015
James Gorman Chimpanzees have the cognitive ability to cook, according to new research, if only someone would give them ovens. It’s not that the animals are ready to go head-to-head with Gordon Ramsay, but scientists from Harvard and Yale found that chimps have the patience and foresight to resist eating raw food and to place it in a device meant to appear, at least to the chimps, to cook it. That is no small achievement. In a line that could easily apply to human beings, the researchers write, “Many primate species, including chimpanzees, have difficulty giving up food already in their possession and show limitations in their self-control when faced with food.” But they found that chimps would give up a raw slice of sweet potato in the hand for the prospect of a cooked slice of sweet potato a bit later. That kind of foresight and self-control is something any cook who has eaten too much raw cookie dough can admire. The research grew out of the idea that cooking itself may have driven changes in human evolution, a hypothesis put forth by Richard Wrangham, an anthropologist at Harvard and several colleagues about 15 years ago in an article in Current Anthropology, and more recently in his book, “Catching Fire: How Cooking Made Us Human.” He argued that cooking may have begun something like two million years ago, even though hard evidence only dates back about one million years. For that to be true, some early ancestors, perhaps not much more advanced than chimps, had to grasp the whole concept of transforming the raw into the cooked. © 2015 The New York Times Company
Link ID: 21016 - Posted: 06.03.2015
By Elahe Izadi Researchers classified two new species of Dusky Antechinus, mouse-like creatures that engage in suicidal reproduction, and published their findings last week in the peer-reviewed journal Memoirs of the Queensland Museum -- Nature. The Mainland Dusky Antechinus, found in southeastern Australia, has been elevated from sub-species to a distinct species. And the newly discovered Tasman Peninsula Dusky Antechinus, found in southeastern Tasmania, already faces the threat of extinction due in part to loss of habitat and feral pests, researchers said. Their proclivity for ferocious, suicidal sex frenzies aren't helping them any. "The breeding period is basically two to three weeks of speed-mating, with testosterone-fueled males coupling with as many females as possible, for up to 14 hours at a time," lead author Andrew Baker of the Queensland University of Technology said in a release. All of that testosterone "triggers a malfunction in the stress hormone shut-off switch" for the males, Baker said. The males then get so stressed out that their immune systems fail, and they die before the females actually give birth. Suicidal reproduction -- or semelparity-- is rare in mammals, and has so far just been documented in these kinds of marsupials.
David Shariatmadari Maybe we should ask the duck-billed platypus. Back in the 1950s, scientists working on humans identified a state marked by increased brain activation, accelerated breathing and heart rate, and muscular paralysis. But perhaps the most remarkable feature was a flickering of the eyes beneath closed eyelids – because all these physiological changes took place while the subjects were fast asleep. What the researchers had discovered became known as the “rapid eye movement” (REM) phase. Under normal circumstances, it recurs every 90 minutes or so, and takes up around 25% of our total time spent sleeping. It quickly became clear that people woken during REM had much better recall of their dreams; in fact, they would often say they’d just that moment been dreaming. As a result, the scientific community began to think of REM as the outward manifestation of the dream state. For the first time in human history, the most extraordinary and fantastical part of our lives had been subject to experimental observation. Not only that, but animals were found to experience REM as well – some of them more often and for longer than humans. We now know that the REM-iest mammal of them all is, bizarrely enough, Ornithorhynchus anatinus, known to you and me as the duck-billed platypus. Perhaps we shouldn’t be surprised, since, as Nature notes, “an account from as long ago as 1860, before REM sleep was discovered, reported that young platypus showed ‘swimming’ movements of their forepaws while asleep”. © 2015 Guardian News and Media Limited
By Fiona Kumfor, Sicong Tu and The Conversation The brain is truly a marvel. A seemingly endless library, whose shelves house our most precious memories as well as our lifetime’s knowledge. But is there a point where it reaches capacity? In other words, can the brain be “full”? The answer is a resounding no, because, well, brains are more sophisticated than that. A study published in Nature Neuroscience earlier this year shows that instead of just crowding in, old information is sometimes pushed out of the brain for new memories to form. Previous behavioural studies have shown that learning new information can lead to forgetting. But in this study, researchers used new neuroimaging techniques to demonstrate for the first time how this effect occurs in the brain. The experiment The paper’s authors set out to investigate what happens in the brain when we try to remember information that’s very similar to what we already know. This is important because similar information is more likely to interfere with existing knowledge, and it’s the stuff that crowds without being useful. To do this, they examined how brain activity changes when we try to remember a “target” memory, that is, when we try to recall something very specific, at the same time as trying to remember something similar (a “competing” memory). Participants were taught to associate a single word (say, the word sand) with two different images—such as one of Marilyn Monroe and the other of a hat. © 2015 Scientific American
Keyword: Learning & Memory
Link ID: 21013 - Posted: 06.03.2015
By Emily DeMarco For owners of picky cats, that disdainful sniff—signaling the refusal of yet another Friskies flavor—can be soul-crushing. Some cats are notoriously finicky eaters, but the reasons behind such fussy behavior remain fuzzy. Previous research has shown that cats can’t taste sweet flavors, but little is known about how they perceive bitter tastes. Now, researchers in the pet food industry have identified two bitter taste receptors in domestic cats, which could help explain why some felines are so choosy when it comes to their chow. In the study, published today in BMC Neuroscience, the scientists used cell-based experiments to see how the two cat taste receptors, known as Tas2r38 and Tas2r43, responded to bitter compounds such as phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP)—which have molecular structures similar to ones in Brussels sprouts and broccoli—as well as aloin (from the aloe plant) and denatonium (used to prevent inadvertent ingestion of some chemicals). When compared with the human versions of these receptors, the researchers found that the cat bitter receptor Tas2r38 was less sensitive to PTC and did not respond to PROP, whereas Tas2r43 was less sensitive to aloin but more sensitive to denatonium, leading the researchers to conclude that cats taste different, and perhaps more narrow, ranges of bitter flavors than humans. The research could help pharmaceutical and pet food manufacturers create compounds that block or inhibit these bitter taste receptors, the team says, potentially leading to more appetizing medicines (if such a thing exists) and foods for our feline companions. © 2015 American Association for the Advancement of Science
Allie Wilkinson For many species, reproduction is a duet between male and female. Now, for the first time, scientists report evidence of 'virgin birth' in a wild vertebrate, the smalltooth sawfish. The fish (Pristis pectinata) normally reproduces sexually, requiring contributions from both sexes. But the latest analysis estimates that nearly 4% of sawfish in a Florida estuary were born without any genetic contribution from a male, in a phenomenon known as parthenogenesis. This asexual reproduction is rare in vertebrates, and had previously been observed only in a handful of species in captivity, including snakes collected from the wild1 and Komodo dragons2. The latest findings appear in the 1 June issue of Current Biology3. Smalltooth sawfish are one of five large ray species that have chainsaw-like appendages protruding from their faces, and are in the same subclass as sharks. The smalltooth sawfish was once abundant along the US eastern and southern coastlines from North Carolina to Texas, but overfishing and coastal development have drastically reduced its numbers. The critically endangered fish are now found only off the coast of southwest Florida. Researchers discovered evidence of 'virgin births' among the sawfish while conducting a routine genetic analysis to determine whether they were inbreeding. Some of the 190 sawfish sampled in a Florida estuary showed unusually high levels of relatedness to other fish in the same population. © 2015 Nature Publishing Group
By Arlene Karidis Health-care professionals, educators and patient advocates debate endlessly over attention deficit disorder. Some argue about the cause of the condition, which is associated with inattentiveness and, often, hyperactivity. Many disagree on treatment and parenting techniques. A dwindling group disputes whether it actually exists. Even its name — to be formal, it’s attention-deficit/hyperactivity disorder — has been a source of debate. The label ADHD trivializes the disorder, asserts Russell Barkley, a neuropsychiatrist and professor of psychiatry and pediatrics at the Medical University of South Carolina who has published more than 300 peer-reviewed articles on the condition. “ADHD is not simply about not being able to pay attention. Describing it as such is like calling autism a ‘not looking at people’ problem,” he said, and there is much more to ADHD. Some practitioners and researchers say drugs are by far the most effective treatment. Others argue that long-term drug use addresses symptoms only and does not provide important tools to help people manage their inattentiveness. They say it’s more helpful to focus on behavioral interventions, nutrition, exercise and special accommodations at school. The American Psychiatric Association says there is no doubt that ADHD exists — and it estimates that 5 percent of U.S. children have the condition.
Link ID: 21008 - Posted: 06.02.2015
By Sarah C. P. Williams Bonobos, endangered great apes considered—along with chimpanzees—the closest living relative to humans, spend most of each day climbing through trees, collecting fruit and leaves. Compare that with the lives of early humans who traversed hot, barren landscapes and it begins to make sense why we’re the fattier, less muscular primate. Over the past 3 decades, two researchers analyzed the hard-to-come-by bodies of 13 bonobos that had died in captivity and compared them with already collected data on 49 human bodies donated by means of autopsy to help understand how evolution drove this change. Although some captive bonobos have become obese, the researchers found that, on average, the apes’ body mass—which is thought to resemble that of the closest common ancestor we share with them—is composed of 10% to 13% skin, whereas humans have only 6% skin. This thinner skin, the team hypothesizes, probably arose around the same time that Homo sapiens gained the ability to sweat, allowing more time spent in hot, open areas. The scientists also found that we pack on more fat than our ape relatives: Female and male humans average 36% and 20% body fat, whereas female and male bonobos average 4% and close to 0% body fat, respectively. Increased fat, the researchers hypothesize, allowed our species to survive—and reproduce—during times of low food availability. As for muscle, the team reports online today in the Proceedings of the National Academy of Sciences, bonobos come out on top, especially when it comes to upper body muscles needed for tree climbing and swinging, which became unnecessary when humans went strictly bipedal. The new findings, the researchers say, help illustrate the forces of natural selection that may have affected H. sapiens’s soft tissues even before our brains started expanding in size and tool use shaped the species. © 2015 American Association for the Advancement of Science.
Lauren Silverman Jiya Bavishi was born deaf. For five years, she couldn't hear and she couldn't speak at all. But when I first meet her, all she wants to do is say hello. The 6-year-old is bouncing around the room at her speech therapy session in Dallas. She's wearing a bright pink top; her tiny gold earrings flash as she waves her arms. "Hi," she says, and then uses sign language to ask who I am and talk about the ice cream her father bought for her. Jiya is taking part in a clinical trial testing a new hearing technology. At 12 months, she was given a cochlear implant. These surgically implanted devices send signals directly to the nerves used to hear. But cochlear implants don't work for everyone, and they didn't work for Jiya. A schoolboy with a cochlear implant listens to his teacher during lessons at a school for the hearing impaired in Germany. The implants have dramatically changed the way deaf children learn and transition out of schools for the deaf and into classrooms with non-disabled students. "The physician was able to get all of the electrodes into her cochlea," says Linda Daniel, a certified auditory-verbal therapist and rehabilitative audiologist with HEAR, a rehabilitation clinic in Dallas. Daniel has been working with Jiya since she was a baby. "However, you have to have a sufficient or healthy auditory nerve to connect the cochlea and the electrodes up to the brainstem." But Jiya's connection between the cochlea and the brainstem was too thin. There was no way for sounds to make that final leg of the journey and reach her brain. © 2015 NPR
By ANDREW POLLACK Is sexual desire a human right? And are women entitled to a little pink pill to help them feel it? Those questions are being raised in a campaign that is pressing the Food and Drug Administration to approve a pill aimed at restoring lost libido in women. The campaign, backed by the drug’s developer and some women’s groups, accuses the F.D.A. of gender bias for approving Viagra and 25 other drugs to help men have sex, but none for women. “Women have waited long enough,” the effort, known as Even the Score, says in an online petition that has gathered more than 40,000 signatures. “In 2015, gender equality should be the standard when it comes to access to treatments for sexual dysfunction.” The drug, flibanserin, has been rejected twice by the F.D.A. on the grounds that its very modest effectiveness was outweighed by side effects like sleepiness, dizziness and nausea. The first rejection, in 2010, followed a decision by a committee of outside advisers to the agency who unanimously opposed approval. On Thursday, F.D.A. advisers will once again consider whether flibanserin should be approved. Sprout Pharmaceuticals, which now owns the drug, has submitted new data, including a study to demonstrate that the pill does not impair driving. Still, approval might hinge on whether the F.D.A. agrees to interpret the old data in a new way and whether the politics of such drugs has changed. © 2015 The New York Times Company
Keyword: Sexual Behavior
Link ID: 21002 - Posted: 06.01.2015
by Jessica Hamzelou Memories that seem to be lost forever may be lurking in the brain after all, ready to be reawakened. The finding, based on experiments in mice, could eventually give us a way to revive memories in people with Alzheimer's or amnesia. When we learn something, sets of neurons in the brain strengthen their mutual connections to lay down lasting memories. Or at least that's the theory. Susumu Tonegawa and his colleagues at the Massachusetts Institute of Technology decided to put it to the test. The team first developed a clever technique to selectively label the neurons representing what is known as a memory engram – in other words, the brain cells involved in forming a specific memory. They did this by genetically engineering mice so they had extra genes in all their neurons. As a result, when neurons fire as a memory is formed, they produce red proteins visible under a microscope, allowing the researchers to tell which cells were part of the engram. They also inserted a gene that made the neurons fire when illuminated by blue light. To mimic memory loss, some of the mice were given a drug that blocks the strengthening of connections between neurons. This made the animals forget their fear of the cage. But the telltale red proteins allowed Tonegawa's team to work out which neurons had been involved in storing the fear memory. They then attempted to reactivate just these neurons using blue light. Sure enough, after the engram had been reactivated, the mice again acted as if they were afraid of the cage. © Copyright Reed Business Information Ltd.
Keyword: Learning & Memory
Link ID: 21001 - Posted: 05.30.2015
Jon Hamilton Antidepressant drugs that work in hours instead of weeks could be on the market within three years, researchers say. "We're getting closer and closer to having really, truly next-generation treatments that are better and quicker than existing ones," says Dr. Carlos Zarate, a researcher at the National Institute of Mental Health. The new drugs are based on the anesthetic ketamine, which is also a popular club drug known as Special K. Unlike current antidepressants, which can take weeks to work, ketamine-like drugs have an immediate effect. They also have helped people with depression who didn't respond to other medications. The drug that is furthest along is esketamine, a chemical variant of ketamine that has been designated a potential breakthrough by the Food and Drug Administration. Esketamine is poised to begin Phase 3 trials, and the drug's maker, Johnson & Johnson, plans to seek FDA approval in 2018. Ketamine, used as a tranquilizer for animals and as an anesthetic in humans, is also being tested as a treatment for depression. Another ketamine-like drug on the horizon is rapastinel. It has completed Phase 2 studies, which showed "rapid, substantial, and sustained reductions in depressive symptoms," according to the drug's maker, Naurex. "I think it's highly probable that we'll see some version of one of these treatments being approved in the relatively near future," says Dr. Gerard Sanacora, director of the Yale Depression Research Program. "In my mind it is the most exciting development in mood disorder treatment in the last 50 years." © 2015 NPR
Link ID: 20999 - Posted: 05.30.2015
A patient tormented by suicidal thoughts gives his psychiatrist a few strands of his hair. She derives stem cells from them to grow budding brain tissue harboring the secrets of his unique illness in a petri dish. She uses the information to genetically engineer a personalized treatment to correct his brain circuit functioning. Just Sci-fi? Yes, but... An evolving “disease-in-a-dish” technology, funded by the National Institutes of Health (NIH), is bringing closer the day when such a seemingly futuristic personalized medicine scenario might not seem so far-fetched. Scientists have perfected mini cultured 3-D structures that grow and function much like the outer mantle – the key working tissue, or cortex — of the brain of the person from whom they were derived. Strikingly, these “organoids” buzz with neuronal network activity. Cells talk with each other in circuits, much as they do in our brains. Sergiu Pasca, M.D. External Web Site Policy, of Stanford University, Palo Alto, CA, and colleagues, debut what they call “human cortical spheroids,” May 25, 2015 online in the journal Nature Methods. Prior to the new study, scientists had developed a way to study neurons differentiated from stem cells derived from patients’ skin cells — using a technology called induced pluripotent stem cells (iPSCs). They had even produced primitive organoids by coaxing neurons and support cells to organize themselves, mimicking the brain’s own architecture. But these lacked the complex circuitry required to even begin to mimic the workings of our brains.
Keyword: Development of the Brain
Link ID: 20998 - Posted: 05.30.2015
by Penny Sarchet The common pet budgerigar (or parakeet) is loved for its ability to mimic its owners. But it has another special trick – it can catch yawns from other budgies, suggesting it has some kind of empathy. "Practically all vertebrates yawn," says Ramiro Joly-Mascheroni of City University, London. In 2008, he showed that dogs can catch yawns from humans. The only other species shown to yawn contagiously are humans, chimpanzees and a type of rodent called the high-yawning Sprague-Dawley rat. But Andrew Gallup of the State University of New York and his colleagues have now shown for the first time that the same happens for a species of non-mammals. To see whether budgies, a sociable parrot species, can make each other yawn, his team designed two experiments. In the first, budgies were placed in adjacent cages, either with a barrier between them, or with nothing obstructing their view of each other. They found that, when budgies could see each other, they were around three times as likely to yawn within five minutes of a yawn from their neighbour. In their second experiment, budgies were shown a video – either one that showed clips of budgies yawning, or one that had no yawning at all. Every bird that watched the yawning video also yawned, while fewer than half of the birds shown the other video yawned. "Thus far, yawning has been demonstrated to be contagious in a few highly social species," said Gallup. "To date, this is the first experimental evidence of contagious yawning in a non-mammalian species." © Copyright Reed Business Information Ltd
Link ID: 20997 - Posted: 05.30.2015