Chapter 16. None

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By Mitch Leslie If you need to lose a lot of weight, surgeons have a drastic option: They can reroute and sometimes remove parts of your stomach, making it smaller. But instead of limiting the amount of food you can eat, the surgery may work by triggering long-term changes in the types of microbes that inhabit your intestines, a new study suggests. If so, altering the kinds of microbes that live in your gut may be a simpler—and safer—route to weight loss. The research provides “some of the best evidence in humans so far” that bariatric surgery works “in part by changing the bacteria in your gut,” says David Cummings, an endocrinologist at the University of Washington, Seattle, who was not involved with the work. Weight loss isn’t the only benefit of so-called bariatric surgery. If a patient has diabetes, for instance, it will usually disappear. The surgery alters metabolism and digestive system functions in several ways, and researchers are still trying to pin down why it’s effective. “This is not about making your stomach small,” says Randy Seeley, an obesity and diabetes researcher at the University of Michigan, Ann Arbor, who wasn’t connected to the study. One way that bariatric surgery might trigger its effects is through its influence on the microbiota, the swarms of microbes that dwell in our intestines and help us digest food. Studies have found that bariatric surgery dramatically alters the microbiota’s makeup in mice and humans. Two years ago, scientists put mice through a Roux-en-Y gastric bypass—a type of bariatric surgery that involves reducing the stomach to a small pouch and stitching it to the middle part of the small intestine—and then transplanted microbes from the slimmed down animals into mice that lacked intestinal bacteria. The recipient rodents lost 5% of their body weight in 2 weeks. But these studies only checked for short-term changes. © 2015 American Association for the Advancement of Science

Keyword: Obesity
Link ID: 21269 - Posted: 08.05.2015

By Julie Scelfo This week, I wrote about the pressures college students face and the related risk for depression and suicide. The article, “Suicide on Campus and the Pressure for Perfection,” generated numerous comments, and readers also raised important questions about other aspects of mental health. Q.Your story seemed to focus on women. Do boys and men experience the same kinds of pressure? A.Yes, male college students experience the same kind of pressure and commit suicide at significantly higher rates than their female counterparts. The rate of suicide among 15 to 24-year-old males in the United States was 17.3 per 100,000 in 2013, compared with 4.5 among females of the same age, according to the Centers for Disease Control and Prevention. In fact, men of all ages are far more likely to commit suicide than women. Q.If men are more likely to commit suicide, why did the story focus on a female student? A. There is still tremendous stigma surrounding mental illness, and not everyone who experiences depression is willing to talk about it. The young woman I profiled, Kathryn DeWitt, offered a rare opportunity to hear from someone who had gone all the way down to the depths of despair but — thankfully — was still alive to talk about it (and could do so articulately). Male depression is a significant concern, and a topic I have written about in the past. More information and resources are available from The National Alliance on Mental Illness. Q.Why didn’t you talk about high rates of suicide among Asian-American students? A.While suicide among Asian-American students is a significant concern, data from the C.D.C. shows the racial/ethnic group with the highest suicide rate is actually American-Indian/Alaskan Native. According to the C.D.C, the rate of suicide in that group for 15 to 24-year-olds is 9.4 for females and a staggering 29.1 for males. Q.Are parents to blame for suicide? A. The cause of any individual suicide is complex, and it would be a mistake to assume parents are to blame if a child attempts suicide. Gregory Eels, the director of Counseling and Psychological Services at Cornell, who has worked in higher education for 20 years and says he has seen “too many” student deaths, describes it this way: “The causes of a completed suicide are never a single thing. It’s a combination of thousands of things.” © 2015 The New York Times Company

Keyword: Depression
Link ID: 21266 - Posted: 08.05.2015

// by Richard Farrell Bonobos have a capacity to do something human infants have been shown to do: use a single sound whose meaning varies based on context, a form of "flexible" communication previously thought specific to humans. The finding was made by researchers from the University of Birmingham and the University of Neuchatel, in a paper just published in the journal Peer J. The newly identified bonobo call is a short, high-pitched "peep," made with a closed mouth. The scientists studied the call's acoustic structure and observed that it did not change between what they termed "neutral" and "positive" circumstances (for example, between activities such as feeding or resting), suggesting that other bonobos receiving the call would need to weigh contextual information to discern its meaning. Human babies do something similarly flexible, using sounds called protophones -- different from highly specific sounds such as crying or laughter -- that are made independent of how they are feeling emotionally. The appearance of this capability in the first year of life is "a critical step in the development of vocal language and may have been a critical step in the evolution of human language," an earlier study on infant vocalization noted. The find challenges the idea that calls from primates such as bonobos -- which, along with chimpanzees, are our closest relatives -- are strictly matched with specific contexts and emotions, whether those sounds are territorial barks or shrieks of alarm. © 2015 Discovery Communications, LLC.

Keyword: Language; Evolution
Link ID: 21265 - Posted: 08.05.2015

By Michael Balter Have you ever wondered why you say “The boy is playing Frisbee with his dog” instead of “The boy dog his is Frisbee playing with”? You may be trying to give your brain a break, according to a new study. An analysis of 37 widely varying tongues finds that, despite the apparent great differences among them, they share what might be a universal feature of human language: All of them have evolved to make communication as efficient as possible. Earth is a veritable Tower of Babel: Up to 7000 languages are still spoken across the globe, belonging to roughly 150 language families. And they vary widely in the way they put sentences together. For example, the three major building blocks of a sentence, subject (S), verb (V), and object (O), can come in three different orders. English and French are SVO languages, whereas German and Japanese are SOV languages; a much smaller number, such as Arabic and Hebrew, use the VSO order. (No well-documented languages start sentences or clauses with the object, although some linguists have jokingly suggested that Klingon might do so.) Yet despite these different ways of structuring sentences, previous studies of a limited number of languages have shown that they tend to limit the distance between words that depend on each other for their meaning. Such “dependency” is key if sentences are to make sense. For example, in the sentence “Jane threw out the trash,” the word “Jane” is dependent on “threw”—it modifies the verb by telling us who was doing the throwing, just as we need “trash” to know what was thrown, and “out” to know where the trash went. Although “threw” and “trash” are three words away from each other, we can still understand the sentence easily. © 2015 American Association for the Advancement of Science.

Keyword: Language; Evolution
Link ID: 21263 - Posted: 08.04.2015

By Roni Caryn Rabin For years experts have urged physicians to screen infants and toddlers for autism in order to begin treatment as early as possible. But now an influential panel of experts has concluded there is not enough evidence to recommend universal autism screening of young children. The findings, from a draft proposal by the U.S. Preventive Services Task Force published Monday, are already causing consternation among specialists who work with autistic children. “I was in a meeting when I read this, and I started feeling like I’d have chest pain,” said Dr. Susan E. Levy, a pediatrician who helped write the American Academy of Pediatrics guidelines urging universal screening of all babies, with standardized screening tools at both 18 and 24 months. “I would hate to see people stop screening.” Dr. David Grossman, a pediatrician and vice chairman of the U.S. Preventive Services Task Force, emphasized that the panel’s draft proposal was a call for more research and not intended to change practices. About half of all pediatricians routinely screen toddlers for autism. “This doesn’t mean ‘don’t screen.’ ” Dr. Grossman said. “It means there is not enough evidence to make a recommendation.” Dr. Grossman also noted that the panel’s conclusion applied only to routine screening of healthy children without symptoms. A child displaying symptoms associated with autism should always be evaluated, he said. “If a parent comes in and says, ‘My child isn’t looking at me,’ that’s not a screening,” Dr. Grossman said. “You hear that as a doctor and you say, ‘That needs to be looked at,’ and you embark on a series of tests.” Despite those reassurances, autism experts worry that the panel’s lack of support for early autism screening could undermine efforts to identify and treat children as early as possible. The task force is an independent panel of experts in prevention and primary care appointed by the federal Department of Health and Human Services. The task force wields enormous influence in the medical community. In 2009, the panel issued controversial screening guidelines for breast cancer, stating that routine mammograms should start at 50 rather than 40. © 2015 The New York Times Company

Keyword: Autism
Link ID: 21262 - Posted: 08.04.2015

By Andrea Alfano Forget the insult “fathead.” We may actually owe our extraordinary smarts to the fat in our brain. A study published in Neuron in February revealed that the variety of fat molecules found in the human neocortex, the brain region responsible for advanced cognitive functions such as language, evolved at an exceptionally fast rate after the human-ape split. The researchers analyzed the concentrations of 5,713 different lipids, or fat molecules and their derivatives, present in samples of brain, kidney and muscle tissues taken from humans, chimpanzees, macaques and mice. Lipids have a variety of critical functions in all cells, including their role as the primary component of a cell's membrane. They are particularly important in the brain because they enable electrical signal transmission among neurons. Yet until this study, it was unknown whether the lipids in the human brain differed significantly from lipids in other mammals. The team discovered that the levels of various lipids found in human brain samples, especially from the neocortex, stood out. Humans and chimps diverged from their common ancestor around the same time, according to much evolutionary evidence. Because the two species have had about the same amount of time to rack up changes to their lipid profiles, the investigators expected them to have roughly the same number of species-specific lipid concentrations, explains computational biologist and study leader Kasia Bozek of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Indeed, lipid changes in the cerebellum, a primitive part of the brain similar in all vertebrates, were comparable between humans and chimps. But the human neocortex has accumulated about three times more lipid changes than the chimpanzee cortex has since we split from our common ancestor. © 2015 Scientific American

Keyword: Evolution
Link ID: 21260 - Posted: 08.04.2015

A protein previously linked to acute symptoms following a traumatic brain injury (TBI), may also be responsible for long-term complications that can result from TBI, according to research from the National Institute of Nursing Research (NINR), a component of the National Institutes of Health. Using an ultra-sensitive technology, researchers — led by NIH Lasker Clinical Research Scholar and Chief of NINR’s Brain Injury Unit, Tissue Injury Branch Jessica Gill, Ph.D., R.N., — were able to measure levels of the protein, tau, in the blood months and years after individuals (in this case, military personnel) had experienced TBI. They found that these elevated levels of tau — a protein known to have a role in the development of Alzheimer’s disease and Parkinson’s disease — are associated with chronic neurological symptoms, including post-concussive disorder (PCD), during which an individual has symptoms such as headache and dizziness in the weeks and months after injury. These chronic neurological symptoms have been linked to chronic traumatic encephalopathy (CTE) — progressive brain degeneration that leads to dementia following repetitive TBIs — independent of other factors such as depression and post-traumatic stress disorder (PTSD). The study and an accompanying editorial appear in the August 3 issue of JAMA Neurology. “Our study was limited to identifying the effects of tau accumulation in military personnel who experienced long-term neurological symptoms after a TBI. With further study, our findings may provide a framework for identifying patients who are most at risk for experiencing chronic symptoms related to TBI. Identifying those at risk early in the progression of the disease provides the best opportunity for therapies that can lessen the cognitive declines that may result from these long-term effects,” said Dr. Gill, the study’s lead author.

Keyword: Brain Injury/Concussion
Link ID: 21259 - Posted: 08.04.2015

Cerebral palsy, the most common cause of physical disability in children, has long been thought to result from brain injury in the fetus. But new Canadian research is challenging that notion, finding that at least one in 10 cases likely has an underlying genetic cause. So ingrained has medical dogma been around the root causes of cerebral palsy that "when I showed the results to our clinical geneticists, initially they didn't believe it," he said. About two in every 1,000 babies born are affected by cerebral palsy. An estimated 50,000 Canadian children and adults have the condition, which leads to varying degrees of motor impairment, including muscle spasticity and involuntary movements. Symptoms can include epilepsy as well as learning, speech, hearing and visual impairments. Some with the disorder are mildly affected, while others can't walk or communicate. Traditionally, cerebral palsy was believed to be caused by a stroke or infection of the brain in the developing fetus, or by birth asphyxia — a lack of oxygen to the infant during delivery. But genetic testing of a group of affected children from across Canada found that in 10 per cent of cases, structural changes to the DNA appear to have given rise to the condition. The research team, which includes physicians at the McGill University Health Centre in Montreal, performed genome sequencing tests on 115 children with cerebral palsy and their parents. ©2015 CBC/Radio-Canada.

Keyword: Development of the Brain; Genes & Behavior
Link ID: 21257 - Posted: 08.04.2015

By Nancy Szokan “This is a story of a family who made mistakes.” Thus Janet Sternburg begins her memoir of a close-knit Jewish family living in Boston. Her grandfather, Philip, was a cold, angry man who abandoned his wife and six children not long after the only son in the family, Bennie, was diagnosed as schizophrenic. As Bennie became increasingly violent and untreatable, the family — advised by a Harvard professor of psychiatry — agreed to submit him to a prefrontal lobotomy. More than a decade later, one of Bennie’s sisters, Francie, sank into a debilitating depression — relentlessly weeping, attempting suicide — and again, the solution was seen to be a lobotomy. While she was growing up, Sternburg accepted the lobotomies as her family’s normalcy. It was decades later, when she was an adult living in California, that it occurred to her to question why such terrible measures had been taken. “The years came back to me when my aunt and uncle were driven to our house” for a regular visit, she writes. As the grandmother cooked and the aunts and uncles talked and played cards, the two lobotomized siblings “sat blankly on the couch — Bennie at one end, virtually unmoving, my aunt crumpled into the far corner. . . . With the sharp return of memories came the realization that even as a child I had a slight awareness . . . that something wrong had been done.” But she also knew her relatives as good and generous people. So she set out to learn what happened, and why. “White Matter: A Memoir of Family and Medicine” is Sternburg’s tale of what she discovered, put in the context of her family’s history.

Keyword: Schizophrenia; Depression
Link ID: 21256 - Posted: 08.04.2015

Joe Palca The sea snail Conus magus looks harmless enough, but it packs a venomous punch that lets it paralyze and eat fish. A peptide modeled on the venom is a powerful painkiller, though sneaking it past the blood-brain barrier has proved hard. The sea snail Conus magus looks harmless enough, but it packs a venomous punch that lets it paralyze and eat fish. A peptide modeled on the venom is a powerful painkiller, though sneaking it past the blood-brain barrier has proved hard. Courtesy of Jeanette Johnson and Scott Johnson Researchers are increasingly turning to nature for inspiration for new drugs. One example is Prialt. It's an incredibly powerful painkiller that people sometimes use when morphine no longer works. Prialt is based on a component in the venom of a marine snail. Prialt hasn't become a widely used drug because it's hard to administer. Mandë Holford is hoping to change that. She and colleagues explain how in their study published online Monday in the journal Scientific Reports. Holford is an associate professor of chemical biology at Hunter College in New York and on the scientific staff of the American Museum of Natural History. As is so often the case in science, her path to working on Prialt wasn't exactly a direct one. She's a chemist, and her first passion was peptides — short strings of amino acids that do things inside cells. "I started out with this love for peptides," Holford says, then laughs. "Love! Sounds weird to say you love peptides out loud." © 2015 NPR

Keyword: Pain & Touch
Link ID: 21255 - Posted: 08.04.2015

By LISA FELDMAN BARRETT OUR senses appear to show us the world the way it truly is, but they are easily deceived. For example, if you listen to a recorded symphony through stereo speakers that are placed exactly right, the orchestra will sound like it’s inside your head. Obviously that isn’t the case. But suppose you completely trusted your senses. You might find yourself asking well-meaning but preposterous scientific questions like “Where in the brain is the woodwinds section located?” A more reasonable approach is not to ask a where question but a how question: How does the brain construct this experience of hearing the orchestra in your head? I have just set the stage to dispel a major misconception about emotions. Most people, including many scientists, believe that emotions are distinct, locatable entities inside us — but they’re not. Searching for emotions in this form is as misguided as looking for cerebral clarinets and oboes. Of course, we experience anger, happiness, surprise and other emotions as clear and identifiable states of being. This seems to imply that each emotion has an underlying property or “essence” in the brain or body. Perhaps an annoying co-worker triggers your “anger neurons,” so your blood pressure rises; you scowl, yell and feel the heat of fury. Or the loss of a loved one triggers your “sadness neurons,” so your stomach aches; you pout, feel despair and cry. Or an alarming news story triggers your “fear neurons,” so your heart races; you freeze and feel a flash of dread. Such characteristics are thought to be the unique biological “fingerprints” of each emotion. Scientists and technology companies spend enormous amounts of time and money trying to locate these fingerprints. They hope someday to identify your emotions from your facial muscle movements, your body changes and your brain’s electrical signals. © 2015 The New York Times Company

Keyword: Emotions
Link ID: 21254 - Posted: 08.02.2015

Teresa Shipley Feldhausen Move over, umami. Fat is the newest member of the pantheon of basic tastes, joining salty, sweet, sour, bitter and savory, or umami. Researchers at Purdue University in West Lafayette, Ind., conducted taste tests pitting a variety of fats against flavors in the other taste categories, such as monosodium glutamate for umami. The result: People recognize some fats as separate from the other five taste categories, even with plugged noses. The researchers dub this sixth sense oleogustus. For instance, nearly two-thirds of tasters identified one type of fat — linoleic acid, found in vegetable and nut oils — as a distinct flavor. Texture wasn’t a factor; the researchers whipped up tasting samples that gave the same mouthfeel. Pure oleogustus doesn’t invoke notes of olive oil or fresh butter. It’s unpleasant, the researchers report online July 3 in Chemical Senses. Mix oleogustus with some of the other five flavors, however, and you could end up with doughnuts or potato chips. Citations C.A. Running, B.A. Craig and R.D. Mattes. Oleogustus: The unique taste of fat. Chemical Senses. Published online July 3, 2015. doi: 10.1093/chemse/bjv036. © Society for Science & the Public 2000 - 2015.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 21252 - Posted: 08.02.2015

By Gary Stix A decline in hearing acuity is not only an occurrence that happens in the aged. An article in the August Scientific American by M. Charles Liberman, a professor of otology and laryngology at Harvard Medical School and director of the Eaton-Peabody Laboratories at Massachusetts Eye and Ear, focuses on relatively recent discoveries that show the din of a concert or high-decibel machine noise is enough to cause some level of hearing damage. After reading the article check out this video by medical illustrator Brandon Pletsch and its narrated animation explaining how the sensory system that detects sound functions. © 2015 Scientific American

Keyword: Hearing
Link ID: 21250 - Posted: 08.02.2015

Alison Abbott Six years might seem like a long time to spend piecing together the structure of a scrap of tissue vastly smaller than a bead of sweat. But that is how long it has taken a team led by cell biologist Jeff Lichtman from Harvard University in Cambridge, Massachusetts, to digitally reconstruct a tiny cube of mouse brain tissue. The resulting three-dimensional map1 is the first complete reconstruction of a piece of tissue in the mammalian neocortex, the most recently evolved region of the brain. Covering just 1,500 cubic microns, it is still a far cry from reconstructing all 100 billion or so cells that make up the entire human brain. But Christof Koch, president of the Allen Institute for Brain Science in Seattle, Washington, notes that the various technologies involved will speed up “tremendously” over the next decade: “I would call this a very exciting promissory note,” he says. Lichtman’s team already has its eyes on a much bigger challenge: reconstructing a cubic millimetre of rodent neocortex — a piece of tissue around 600,000 times larger than the present achievement. The researchers will be doing this as part of a consortium that earlier this month received preliminary approval for major funding by the US government agency IARPA (Intelligence Advanced Research Projects Activity), which promotes high-risk, high pay-off research. The goal of the consortium, based at Harvard and at the Massachusetts Institute of Technology (MIT) in Cambridge, is to map the function as well as the anatomy of this tiny brain volume, while also working out how it computes information as an animal learns. © 2015 Nature Publishing Group,

Keyword: Brain imaging
Link ID: 21249 - Posted: 08.01.2015

Kill, Fido! Docile ants become aggressive guard dogs after a secret signal from their caterpillar overlord. The idea turns on its head the assumption that the two species exchange favours in an even-handed relationship. The caterpillars of the Japanese oakblue butterfly (Narathura japonica) grow up wrapped inside leaves on oak trees. To protect themselves against predators like spiders and wasps, they attract ant bodyguards, Pristomyrmex punctatus, with an offering of sugar droplets. The relationships was thought to be a fair exchange of services in which both parties benefit. But Masaru Hojo from Kobe University in Japan noticed something peculiar: the caterpillars were always attended by the same ant individuals. “It also seemed that the ants never moved away or returned to their nests,” he says. They seemed to abandon searching for food, and were just standing around guarding the caterpillar. Intrigued, Hojo and his colleagues conducted lab experiments in which they allowed some ants to interact with the caterpillars and feed on the secretions, and kept others separate. Ants that ate the caterpillar’s secretions remained close to the caterpillar. They didn’t return to their nest. And whenever the caterpillar everted its tentacles – flipped them so they turned inside out – the ants moved around rapidly, acting aggressively. © Copyright Reed Business Information Ltd.

Keyword: Evolution; Drug Abuse
Link ID: 21244 - Posted: 08.01.2015

Five men with complete motor paralysis were able to voluntarily generate step-like movements thanks to a new strategy that non-invasively delivers electrical stimulation to their spinal cords, according to a new study funded in part by the National Institutes of Health. The strategy, called transcutaneous stimulation, delivers electrical current to the spinal cord by way of electrodes strategically placed on the skin of the lower back. This expands to nine the number of completely paralyzed individuals who have achieved voluntary movement while receiving spinal stimulation, though this is the first time the stimulation was delivered non-invasively. Previously it was delivered via an electrical stimulation device surgically implanted on the spinal cord. In the study, the men’s movements occurred while their legs were suspended in braces that hung from the ceiling, allowing them to move freely without resistance from gravity. Movement in this environment is not comparable to walking; nevertheless, the results signal significant progress towards the eventual goal of developing a therapy for a wide range of individuals with spinal cord injury. “These encouraging results provide continued evidence that spinal cord injury may no longer mean a life-long sentence of paralysis and support the need for more research,” said Roderic Pettigrew, Ph.D., M.D., director of the National Institute of Biomedical Imaging and Bioengineering at NIH. “The potential to offer a life-changing therapy to patients without requiring surgery would be a major advance; it could greatly expand the number of individuals who might benefit from spinal stimulation. It’s a wonderful example of the power that comes from combining advances in basic biological research with technological innovation.”

Keyword: Robotics
Link ID: 21242 - Posted: 08.01.2015

By JESSE McKINLEY ALBANY — In a case watched by animal rights activists and courtroom curiosity seekers, a State Supreme Court judge in Manhattan on Thursday denied a request to free a pair of chimpanzees, Hercules and Leo, being held at a state university on Long Island. The unorthodox petition — which sought a writ of habeas corpus, an age-old method of challenging unlawful imprisonment — was the latest attempt by the nonprofit Nonhuman Rights Project to establish that apes are “legal persons.” The group argues that chimps are self-aware and autonomous, a contention it has supported by submitting affidavits attesting to the animals’ intelligence, language skills and personalities, among other traits, in several cases filed in New York on behalf of various imprisoned primates. In what the group hoped was a positive sign, Justice Barbara Jaffe of State Supreme Court in April ordered a hearing on whether Hercules and Leo, 8-year-old apes living as research subjects at the State University of New York at Stony Brook, could be released and transferred to an animal sanctuary in Florida. Arguments were heard in late May. But while Justice Jaffe took the case seriously — her 33-page decision cited the long history of habeas corpus and included references to discrimination against women and African-American slaves — she could not quite see Hercules and Leo as people in the eyes of the law. “For the purpose of establishing rights, the law presently categorizes entities in a simple, binary, ‘all or nothing,’ fashion,” the justice wrote, noting: “Persons have rights, duties, and obligations. Things do not.” “Animals, including chimpanzees and other highly intelligent mammals, are considered property under the law,” she continued. “They are accorded no legal rights,” beyond being free from mistreatment or abuse. © 2015 The New York Times Company

Keyword: Animal Rights
Link ID: 21241 - Posted: 07.31.2015

Ewen Callaway Our ancestors were not a picky bunch. Overwhelming genetic evidence shows that Homo sapiens had sex with Neander­thals, Denisovans and other archaic relatives. Now researchers are using large genomics studies to unravel the decidedly mixed contributions that these ancient romps made to human biology — from the ability of H. sapiens to cope with environments outside Africa, to the tendency of modern humans to get asthma, skin diseases and maybe even depression. The proportion of the human genome that comes from archaic relatives is small. The genomes of most Europeans and Asians are 2–4% Neanderthal1, with Denisovan DNA making up about 5% of the genomes of Mela­nesians2 and Aboriginal Australians3. DNA slivers from other distant relatives probably pepper a variety of human genomes4. But these sequences may have had an outsize effect on human biology. In some cases, they are very different from the corresponding H. sapiens DNA, notes population geneticist David Reich of Harvard Medical School in Boston, Massachusetts — which makes it more likely that they could introduce useful traits. “Even though it’s only a couple or a few per cent of ancestry, that ancestry was sufficiently distant that it punched above its weight,” he says. Last year, Reich co-led one of two teams that catalogued the Neanderthal DNA living on in modern-day humans5, 6. The studies hinted that Neanderthal versions of some genes may have helped Eurasians to reduce heat loss or grow thicker hair. But the evidence that these genes were beneficial was fairly weak. To get a better handle on how Neanderthal DNA shapes human biology, Corinne Simonti and Tony Capra, evolutionary geneticists at Vanderbilt University in Nashville, Tennessee, turned to genome-wide association studies (GWAS) that had already compared thousands of DNA variants in people with and without a certain disease or condition. © 2015 Nature Publishing Group,

Keyword: Evolution
Link ID: 21240 - Posted: 07.30.2015

By Katie Free Shouting during a nightmare. Struggling to balance a checkbook. A weakened sense of smell. Hallucinations. Chronic constipation. This bizarre mix of symptoms often stumps doctors, but they are some of the telltale signs of Lewy body dementia—the second most common type (after Alzheimer's disease), affecting an estimated 1.4 million Americans. Lewy bodies are protein clumps that kill neurons. Depending on where they cluster in the brain, they can cause either Parkinson's disease or Lewy body dementia, although the two conditions tend to overlap as they progress. Lewy body dementia is more difficult to diagnose and treat, in part because the earliest warning signs have remained unknown. Now a new study finds that certain sensory and motor symptoms can help predict who will acquire the disease, paving the way for targeted studies. Researchers at the Center for Advanced Research in Sleep Medicine (which is associated with the University of Montreal) and at McGill University followed 89 patients with a history of acting out their dreams—not sleepwalking but moving or vocalizing in bed during rapid eye movement (REM) sleep. The failure to suppress such nighttime activity can be an early sign that something is going wrong in the brain; past studies have shown that up to 80 percent of patients who act out their dreams will eventually develop some form of neurodegeneration. Over 10 years the McGill researchers carefully tracked the patients' other potential symptoms of neural disease, such as mild cognitive impairment, depression and movement problems. They found a cluster of symptoms—abnormal color vision, loss of smell and motor dysfunction—that doubled the chance that a person with the REM sleep disorder would develop Parkinson's or Lewy body dementia within three years, according to the study published in February in Neurology. © 2015 Scientific American

Keyword: Alzheimers
Link ID: 21237 - Posted: 07.30.2015

By Sophia Kercher As Kathleen Emmets was undergoing cancer treatment in New York over the past few years, her weight began to drop. Even though she was often nauseated and paralyzed by chemotherapy-induced neuropathy, she joked that thinness was the “bonus of cancer,” and found herself looking in the mirror and admiring her deep and hollow collarbone. Ms. Emmets, now 39, filled her closet with extra-small size clothes. At night she pressed her fingers against her protruding bones, saying to herself, “I’m finally skinny.” But it was only when her cancer treatment changed that it became clear that the body-image issues she had been grappling with since her early 20s — when she would eat next to nothing and walk for six hours a day to deal with stress — had begun to resurface. When the new treatment didn’t make her sick, her appetite returned, and she began to gain weight. But instead of celebrating this sign of improving health, Ms. Emmets says she missed her size 2 jeans and was appalled by her round belly and full breasts. Her husband watched with concern as her body appeared stronger but she began imposing her own food restrictions and started shrinking again. “During your cancer treatment, you have no control over your body — you give up your body to your doctor,” said Ms. Emmets, who wrote about her experiences on the website The Manifest-Station. “You are willing to do it because you want to live. Food restriction is the one thing that you can do to have some sense of control when everything is chaotic.” While it isn’t known how often cancer triggers or reawakens an eating disorder, doctors and nutrition experts who work with cancer patients share anecdotal reports of patients who emerge from a difficult round of cancer treatment and weight loss only to begin struggling with a serious eating disorder that threatens their postcancer health. © 2015 The New York Times Company

Keyword: Anorexia & Bulimia
Link ID: 21236 - Posted: 07.30.2015