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By Helen Thomson High levels of inflammation as a child may predict a higher risk of manic behaviour in later life, a finding that could lead to new ways of treating conditions like bipolar disorder. Hypomania involves spells of hyperactivity and is often a symptom of mood disorders, including bipolar disorder, seasonal affective disorder and some kinds of psychosis. People experiencing hypomania may take more risks, feel more confident and become impatient with others. After spells like this, they may “crash”, needing to sleep for long periods and sometimes remembering little about the previous few days. Earlier studies suggested a link between inflammation and mood disorders, prompting Joseph Hayes at University College London and his team to see if inflammation as a child might lead to mental health problems later. Analysing data from more than 1700 people, his team identified a significant link between high levels of a chemical involved in inflammation at age 9, and experiencing aspects of hypomania at age 22. The chemical, called IL-6, is normally secreted by white blood cells to stimulate an inflammatory immune response to infection or trauma. Hayes’s team says it is unclear how inflammation in childhood could induce symptoms of hypomania but IL-6 is known to affect the brain. A study that used injections to increase IL-6 in the blood of healthy volunteers found that this caused symptoms of anxiety, and reduced performance in memory tests. © Copyright Reed Business Information Ltd.
Link ID: 22636 - Posted: 09.07.2016
Hannah Devlin Science correspondent Babies born by caesarean section are more likely to be obese as adults, according to a study that suggests the way we are born could have a lasting impact on health. Birth by caesarean was linked to a 15% higher risk of obesity in children compared with vaginal birth. The scientists involved believe that babies born by caesarean miss out on exposure to bacteria in the birth canal that colonise the baby’s gut and may ultimately change the body’s metabolic rate - and even how hungry we feel. Audrey Gaskins, an epidemiologist at Harvard University and co-author of the new study, said: “Children born via C-section harbour less diverse gut bacteria and these patterns of less diversity have been linked to increased capacity for energy harvest by the gut microbiota. You can think of it as a slower metabolism.” Previous studies have found the same link, but were less able to rule out other factors, such as the mother’s weight or health. The latest research, which included 22,068 children born to 15,271 women, suggests that the link is not simply explained by overweight women or those with pregnancy complications such as high blood pressure being more likely to deliver by caesarean. The link remained after maternal weight was taken into account, and was more striking when siblings who had different types of births were compared. Within families, children born by caesarean were 64% more likely to be obese than their siblings born by vaginal delivery. “With siblings, they have the same mother and home environment so the genetics, the feeding environment, are all controlled for,” said Dr Gaskins. © 2016 Guardian News and Media Limited
By JANE E. BRODY As a woman of a certain age who consumes a well-balanced diet of all the usual food groups, including reasonable amounts of animal protein, I tend to dismiss advice to take a multivitamin supplement. I’ve been told repeatedly by nutrition experts that the overuse of dietary supplements for “nutritional insurance” has given Americans the most expensive urine in the world. I do take a daily supplement of vitamin D, based on considerable evidence of its multiple health benefits, especially for older people. However, based on advice from the National Academy of Medicine and an examination of accumulating research, I’m prompted to consider also taking a vitamin B12 supplement in hopes of protecting my aging brain. Animal protein foods — meat, fish, milk, cheese and eggs — are the only reliable natural dietary sources of B12, and I do get ample amounts of several in my regular diet. But now at age 75, I wonder whether I’m still able to reap the full benefit of what I ingest. You see, the ability to absorb B12 naturally present in foods depends on the presence of adequate stomach acid, the enzyme pepsin and a gastric protein called intrinsic factor to release the vitamin from the food protein it is attached to. Only then can the vitamin be absorbed by the small intestine. As people age, acid-producing cells in the stomach may gradually cease to function, a condition called atrophic gastritis. A century ago, researchers discovered that some people — most likely including Mary Todd Lincoln — had a condition called pernicious anemia, a deficiency of red blood cells ultimately identified as an autoimmune disease that causes a loss of stomach cells needed for B12 absorption. Mrs. Lincoln was known to behave erratically and was ultimately committed to a mental hospital. © 2016 The New York Times Company
Keyword: Development of the Brain
Link ID: 22634 - Posted: 09.06.2016
Chris Chambers One of the most compelling impressions in everyday life is that wherever we look, we “see” everything that is happening in front of us – much like a camera. But this impression is deceiving. In reality our senses are bombarded by continual waves of stimuli, triggering an avalanche of sensations that far exceed the brain’s capacity. To make sense of the world, the brain needs to determine which sensations are the most important for our current goals, focusing resources on the ones that matter and throwing away the rest. These computations are astonishingly complex, and what makes attention even more remarkable is just how effortless it is. The mammalian attention system is perhaps the most efficient and precisely tuned junk filter we know of, refined through millions of years of annoying siblings (and some evolution). Attention is amazing but no system is ever perfect. Our brain’s computational reserves are large but not infinite, and under the right conditions we can “break it” and peek behind the curtain. This isn’t just a fun trick – understanding these limits can yield important insights into psychology and neurobiology, helping us to diagnose and treat impairments that follow brain injury and disease. Thanks to over a hundred years of psychology research, it’s relatively easy to reveal attention in action. One way is through the phenomenon of change blindness. Try it yourself by following the instructions in the short video below (no sound). When we think of the term “blindness” we tend to assume a loss of vision caused by damage to the eye or optic nerves. But as you saw in the video, change blindness is completely normal and is caused by maxing out your attentional capacity. © 2016 Guardian News and Media Limited
By Clare Wilson Traffic fumes go to your head. Tiny specks of metal in exhaust gases seem to fly up our noses and travel into our brains, where they may contribute to Alzheimer’s disease. Iron nanoparticles were already known to be present in the brain – but they were thought to come from the iron naturally found in our bodies, derived from food. Now a closer look at their structure suggests the particles mostly come from air pollution sources, like traffic fumes and coal burning. The findings are a smoking gun, says Barbara Maher of Lancaster University in the UK. Iron is present harmlessly in our bodies in different forms, as it is part of many biological molecules. But the form known as magnetite, or iron oxide, which is highly reactive and magnetic, has been implicated in Alzheimer’s disease. Maher’s team looked at the brains of 37 people who had lived either in Manchester in the UK or Mexico City. All contained millions of magnetite particles per gram of brain tissue, detected by measuring how magnetic the brain tissue was. The surprise came when the team used electron microscopes to take a close look at particles in the front part of the brains of six people. Round particles of magnetite outnumbered angular magnetite crystals by about one hundred to one. Crystal forms are more likely to have a natural source – such as iron that has come out of the body’s cells. But round particles normally come from melting iron at high temperatures, which happens when fuel is burned. © Copyright Reed Business Information Ltd.
Link ID: 22632 - Posted: 09.06.2016
Susan Milius Contrary to many adorable children’s stories, hibernation is so not sleeping. And most animals can’t do both at the same time. So what’s with Madagascar’s dwarf lemurs? The fat-tailed dwarf lemur slows its metabolism into true hibernation, and stays there even when brain monitoring shows it’s also sleeping. But two lemur cousins, scientists have just learned, don’t multitask. Like other animals, they have to rev their metabolisms out of hibernation if they want a nap. Hibernating animals, in the strictest sense, stop regulating body temperature, says Peter Klopfer, cofounder of the Duke Lemur Center in Durham, N.C. “They become totally cold-blooded, like snakes.” By this definition, bears don’t hibernate; they downregulate, dropping their body temperatures only modestly, even when winter den temperatures sink lower. And real hibernation lasts months, disqualifying short-termers such as subtropical hummingbirds. The darting fliers cease temperature regulation and go truly torpid at night. “You can pick them out of the trees,” Klopfer says. The fat-tailed dwarf lemur, Cheirogaleus medius, was the first primate hibernator discovered, snuggling deep into the softly rotting wood of dead trees. “You’d think they’d suffocate,” he says. But their oxygen demands plunge to somewhere around 1 percent of usual. As trees warm during the day and cool at night, so do these lemurs. When both a tree and its inner lemur heat up, the lemur’s brain activity reflects mammalian REM sleep. |© Society for Science & the Public 2000 - 2016
By Andy Coghlan Antidepressants may be bad for your bones. People who take some selective serotonin reuptake inhibitors (SSRI) have been found to have a higher risk of fractures, but it wasn’t clear whether this was due to the drug or their depression. “It’s a puzzling question,” says Patricia Ducy at Columbia University, New York. But her team have now found that giving mice fluoxetine – the active ingredient in Prozac – for six weeks causes them to lose bone mass. The team identified a two-stage process by measuring bones, blood and gene activity. During the first three weeks, bones grew stronger as the fluoxetine impaired osteoclasts, cells that usually deplete bone tissue. But by six weeks, the higher levels of serotonin prompted by the drug disrupted the ability of the hypothalamus region of the brain to promote bone growth. “We see bone gain, but it’s not long-lasting, and is rapidly overwhelmed by the negative effects,” says Ducy. She says this two-phase pattern is also seen in people. In the short term, those who take fluoxetine are less likely to break a bone, but the risk of bone depletion and fractures rises when they have been taking the drug for a year or more. © Copyright Reed Business Information Ltd.
Link ID: 22630 - Posted: 09.06.2016
By The Scientist Staff Growing up, we learn that there are five senses: sight, smell, touch, taste, and hearing. For the past five years, The Scientist has taken deep dives into each of those senses, explorations that revealed diverse mechanisms of perception and the impressive range of these senses in humans and diverse other animals. But as any biologist knows, there are more than just five senses, and it’s difficult to put a number on how many others there are. Humans’ vestibular sense, for example, detects gravity and balance through special organs in the bony labyrinth of the inner ear. Receptors in our muscles and joints inform our sense of body position. (See “Proprioception: The Sense Within.”) And around the animal kingdom, numerous other sense organs aid the perception of their worlds. The comb jelly’s single statocyst sits at the animal’s uppermost tip, under a transparent dome of fused cilia. A mass of cells called lithocytes, each containing a large, membrane-bound concretion of minerals, forms a statolith, which sits atop four columns called balancers, each made up of 150–200 sensory cilia. As the organism tilts, the statolith falls towards the Earth’s core, bending the balancers. Each balancer is linked to two rows of the ctenophore’s eight comb plates, from which extend hundreds of thousands of cilia that beat together as a unit to propel the animal. As the balancers bend, they adjust the frequency of ciliary beating in their associated comb plates. “They’re the pacemakers for the beating of the locomotor cilia,” says Sidney Tamm, a researcher at the Marine Biological Laboratory in Woods Hole, Massachusetts, who has detailed the structure and function of the ctenophore statocyst (Biol Bull, 227:7-18, 2014; Biol Bull, 229:173-84, 2015). © 1986-2016 The Scientist
By Jesse Singal Back in 2014, a bigoted African leader put J. Michael Bailey, a psychologist at Northwestern, in a strange position. Yoweri Museveni, the president of Uganda, had been issuing a series of anti-gay tirades, and — partially fueled by anti-gay religious figures from the U.S. — was considering toughening Uganda’s anti-gay laws. The rhetoric was getting out of control: “The commercialisation of homosexuality is unacceptable,” said Simon Lokodo, Uganda’s ethics minister. “If they were doing it in their own rooms we wouldn’t mind, but when they go for children, that’s not fair. They are beasts of the forest.” Eventually, Museveni said he would table the idea of new legislation until he better understood the science of homosexuality, and agreed to lay off Uganda’s LGBT population if someone could prove to him homosexuality was innate. That’s where Bailey comes in: He’s a leading sex researcher who has published at length on the question of where sexual orientation comes from. LGBT advocates began reaching out to him to explain the science of homosexuality and, presumably, denounce Museveni for his hateful rhetoric. But “I had issues with rushing out a scientific statement that homosexuality is innate,” he said in an email, because he’s not sure that’s quite accurate. While he did write articles, such as an editorial in New Scientist, explaining why he thought Museveni’s position didn’t make sense, he stopped short of calling homosexuality innate. He also realized that in light of some recent advances in the science of sexual orientation, it was time to publish an article summing up the current state of the field — gathering together all that was broadly agreed-upon about the nature and potential origins of sexual orientation. (In the meantime, Museveni did end up signing the anti-gay legislation, justifying his decision by reasoning that homosexuality “was learned and could be unlearned.”) © 2016, New York Media LLC.
A new study by investigators at Brigham and Women's Hospital in collaboration with researchers at the University of York and Leeds in the UK and MD Andersen Cancer Center in Texas puts to the test anecdotes about experienced radiologists' ability to sense when a mammogram is abnormal. In a paper published August 29 in the Proceedings of the National Academy of Sciences, visual attention researchers showed radiologists mammograms for half a second and found that they could identify abnormal mammograms at better than chance levels. They further tested this ability through a series of experiments to explore what signal may alert radiologists to the presence of a possible abnormality, in the hopes of using these insights to improve breast cancer screening and early detection. "Radiologists can have 'hunches' after a first look at a mammogram. We found that these hunches are based on something real in the images. It's really striking that in the blink of an eye, an expert can pick up on something about that mammogram that indicates abnormality," said Jeremy Wolfe, PhD, senior author of the study and director of the Visual Attention Laboratory at BWH. "Not only that, but they can detect something abnormal in the other breast, the breast that does not contain a lesion." In the clinic, radiologists carefully evaluate mammograms and may use computer automated systems to help screen the images. Although they would never assess an image in half a second in the clinic, the ability of experts to extract the "gist" of an image quickly suggests that there may be a detectable signs of breast cancer that radiologists are rapidly picking up. Copyright 2016 ScienceDaily
By Alison F. Takemura A stationary Carolina sphinx moth (Manduca sexta) is the Cinderella of the animal kingdom. The hummingbird-size insect has dull, dark wings that are mottled like charred wood, and a plump body reminiscent of a small breakfast sausage. Casual observers of M. sexta often see little else. “They say, ‘Oh, it doesn’t look so nice. It’s just grey.’ But as soon as [the moths] start flying, they’re completely impressed,” says Danny Kessler, a pollination ecologist at the Max Planck Institute of Chemical Ecology in Germany. “They change their minds completely.” Hawkmoths, the group to which M. sexta belongs, whir their wings like hummingbirds as they flit between flowers, hovering to drink nectar. M. sexta’s proboscis, longer than its 2-inch body, stays unfurled, a straw ready to sip. Kessler studies the interaction between the Carolina sphinx moth, whose larvae are known as tobacco hornworms, and its preferred food source, the coyote tobacco plant (Nicotiana attenuata), to better understand how insect behavior affects a plant’s reproductive success. M. sexta adults drink nectar from tobacco’s skinny, white, trumpet-shape flowers, foraging from them at night and pollinating them in the process. Scientists have known for decades that the moth uses its antennae to detect the flowers’ scent—even from several miles away, Kessler says. © 1986-2016 The Scientist
Keyword: Chemical Senses (Smell & Taste)
Link ID: 22626 - Posted: 09.05.2016
ByAnna Vlasits The next revolution in medicine just might come from a new lab technique that makes neurons sensitive to light. The technique, called optogenetics, is one of the biggest breakthroughs in neuroscience in decades. It has the potential to cure blindness, treat Parkinson’s disease, and relieve chronic pain. Moreover, it’s become widely used to probe the workings of animals’ brains in the lab, leading to breakthroughs in scientists’ understanding of things like sleep, addiction, and sensation. So it’s not surprising that the two Americans hailed as inventors of optogenetics are rock stars in the science world. Karl Deisseroth at Stanford University and Ed Boyden at the Massachusetts Institute of Technology have collected tens of millions in grants and won millions in prize money in recent years. They’ve stocked their labs with the best equipment and the brightest minds. They’ve been lauded in the media and celebrated at conferences around the world. They’re considered all but certain to win a Nobel Prize. There’s only one problem with this story: It just may be that Zhuo-Hua Pan invented optogenetics first. Even many neuroscientists have never heard of Pan. Pan, 60, is a vision scientist at Wayne State University in Detroit who began his research career in his home country of China. He moved to the United States in the 1980s to pursue his PhD and never left. He wears wire-rimmed glasses over a broad nose framed by smile-lines in his cheeks. His colleagues describe him as a pure scientist: modest, dedicated, careful.
Keyword: Brain imaging
Link ID: 22625 - Posted: 09.03.2016
By LISA SANDERS, M.D. On Thursday, we challenged Well readers to take on the complicated case of a 50-year-old woman who felt feverish and couldn’t stop vomiting and who ended up losing a lot of weight. Like the doctors who saw her as she searched for a diagnosis, many of you focused on her recent journey to Kenya as the source of her symptoms. It was a completely reasonable approach, and one that was extensively explored by the doctors who cared for her. But ultimately it was incorrect. This was a really tough case. Indeed, only three of you got it right. The correct diagnosis was: Hyperthyroidism Thyroid hormone controls metabolism. The more of this hormone flowing in the body, the harder the body works. Because this hormone plays such an important role in how we function, the body tightly regulates how much of it is released and when. But just like every other system in the body, that regulatory mechanism can mess up, releasing either too little hormone (hypothyroidism) or, as in this case, too much. The usual symptoms of hyperthyroidism are pretty apparent: The heart races; patients are sweaty, shaky, itchy and sometimes feverish. The appetite increases, but because the entire body is revved up, there is often weight loss. Bowel movements become more frequent and sleep harder to come by. Frequent and uncontrolled vomiting is less common but has been reported. This patient had all of these symptoms. The most common cause of hyperthyroidism is an autoimmune disorder known as Graves’ disease, named after Dr. Robert Graves, a 19th-century Irish physician who wrote about the phenomenon of rapid and violent palpitations associated with an enlarged thyroid gland. In the 20th century it was discovered that the symptoms result when antibodies, the foot soldiers of the immune system, cause excess stimulation of the thyroid gland, resulting in the uncontrolled production and release of thyroid hormone. © 2016 The New York Times Company
Keyword: Hormones & Behavior
Link ID: 22624 - Posted: 09.03.2016
By Christof Koch Flies, birds, mice, dogs, monkeys and people all need to sleep. That is, they show daily periods of relative immobility and lack of response to external stimuli, such as light, sound or touch. This reduced sensitivity to external events distinguishes sleep from quiet resting, whereas the capacity to awaken from slumber distinguishes sleep from coma. Why sleep should be such a prominent feature of daily life across the animal kingdom, despite the fact that it leaves the sleeper unable to confront potential threats, remains mysterious. Still, much progress in characterizing the physiology and capabilities of the sleeping brain has occurred over the past century, driven by the ability to record electrical activity of the brain (via electroencephalography, or EEG, on the surface of the skull), of the eyes (via electrooculography, or EOG), and of facial or other muscles (via electromyography, or EMG). For scientists, it is this triad of simultaneous measurements that operationally defines the state of sleep, leading to both surprising and counterintuitive insights. Even without these tools, there are some basic things we do know about sleep. It is essential for our brain to function properly. Most of us have pulled all-nighters or have wanted to sleep but could not, unable to switch off our mind. The next day we are irritable, have trouble keeping our eyes open, and are terrible at tasks that demand sustained attention. Indeed, sleep deprivation causes many traffic accidents—the reason countries have laws that mandate a minimum rest period and maximum working hours for truck drivers. © 2016 Scientific American,
By JOHN P. GLUCK Albuquerque, N.M. — Five years ago, the National Institutes of Health all but ended biomedical and behavioral research on chimpanzees, concluding that, as the closest human relative, they deserved “special consideration and respect.” But chimpanzees were far from the only nonhuman primates used in research then, or now. About 70,000 other primates are still living their lives as research subjects in labs across the United States. On Wednesday, the N.I.H. will hold a workshop on “continued responsible research” with these animals. This sounds like a positive development. But as someone who spent decades working almost daily with macaque monkeys in primate research laboratories, I know firsthand that “responsible” research is not enough. What we really need to examine is the very moral ground of animal research itself. Like many researchers, I once believed that intermittent scientific gains justified methods that almost always did harm. As a graduate student in the late 1960s, I came to see that my natural recoil from intentionally harming animals was a hindrance to how I understood scientific progress. I told myself that we were being responsible by providing good nutrition, safe cages, skilled and caring caretakers and veterinarians for the animals — and, crucially, that what we stood to learn outweighed any momentary or prolonged anguish these animals might experience. The potential for a medical breakthrough, the excitement of research and discovering whether my hypotheses were correct — and let’s not leave out smoldering ambition — made my transition to a more “rigorous” stance easier than I could have imagined. One of my areas of study focused on the effects of early social deprivation on the intellectual abilities of rhesus monkeys. We kept young, intelligent monkeys separated from their families and others of their kind for many months in soundproof cages that remained lit 24 hours a day, then measured how their potential for complex social and intellectual lives unraveled. All the while, I comforted myself with the idea that these monkeys were my research partners, and that by creating developmental disorders in monkeys born in a lab, we could better understand these disorders in humans. © 2016 The New York Times Company
Keyword: Animal Migration
Link ID: 22622 - Posted: 09.03.2016
Laura Sanders An experimental drug swept sticky plaques from the brains of a small number of people with Alzheimer’s disease over the course of a year. And preliminary results hint that this cleanup may have staved off mental decline. News about the new drug, an antibody called aducanumab, led to excitement as it trickled out of recent scientific meetings. A paper published online August 31 in Nature offers a more comprehensive look at the drug’s effects. “Overall, this is the best news that we’ve had in my 25 years doing Alzheimer’s clinical research,” study coauthor Stephen Salloway of Brown University said August 30 at a news briefing. “It brings new hope for patients and families most affected by the disease.” The results are the most convincing evidence yet that an antibody can reduce amyloid in the brain, says Alzheimer’s researcherRachelle Doody of Baylor College of Medicine in Houston, who was not involved in the study. Still, experts caution that the results come from 165 people, a relatively small number. The seemingly beneficial effects could disappear in larger clinical trials, which are under way. “These new data are tantalizing, but they are not yet definitive,” says neuroscientist John Hardy of University College London. Like some other drug candidates for Alzheimer’s, aducanumab is an antibody that targets amyloid-beta, a sticky protein that accumulates in the brains of people with the disease. Delivered by intravenous injection, aducanumab appeared to get inside the brains of people with mild Alzheimer’s (average age about 73) and destroy A-beta plaques, the results suggest. After a year of exposure to the drug, A-beta levels had dropped. This reduction depended on the dose — the more drug, the bigger the decline in A-beta. In fact, people on the highest dose of the drug had almost no A-beta plaques in their brains after a year. |© Society for Science & the Public 2000 - 2016.
Link ID: 22621 - Posted: 09.01.2016
By Laurie McGinley The Food and Drug Administration, alarmed that increasing numbers of Americans are combining opioid painkillers and benzodiazepines, said Wednesday that it will require tough new warnings on the product labels that spell out the serious dangers of mixing the drugs. The agency said it will require “boxed warnings” — its strongest category — on 389 separate products and will mandate the warning on opioid-containing cough medications. The new language will list the hazards of using the medications in tandem, which include extreme sleepiness, respiratory depression, coma and even death. The agency noted that the misuse of opioids, powerful pain medications such as prescription oxycodone, hydrocodone and morphine, has “increased significantly” in the United States over the past two decades. Benzodiazepines are used to treat anxiety, insomnia and seizure disorders. Both classes of drugs depress the central nervous system and together can raise the risk of adverse outcomes. FDA officials said the number of patients prescribed both an opioid and a benzodiazepine increased by 41 percent — about 2.5 million people — between 2002 and 2014. From 2004 to 2011, the rate of emergency-department visits involving the non-medical use of both drug classes increased significantly and overdose deaths nearly tripled, the FDA said.
Merrit Kennedy More than 1,000 residents of a public housing complex in East Chicago, Ind., are now forced to relocate because of dangerously high lead levels in the area's soil. The West Calumet Housing Complex, which houses primarily low-income families, lies on the site of a former lead smelting company, as member station WBEZ reported. In July, the Environmental Protection Agency reported high lead levels in the soil in parts of the complex and notified the residents. The EPA advised parents to stop their kids from playing in the dirt, "to wash their children's toys regularly and to wash children's hands after they play outside." As WBEZ reported, the samples showed lead levels "three times higher than the federal safety standards and in some places even higher, much higher." After that, East Chicago Mayor Anthony Copeland "ordered the removal of 1,200 residents from the West Calumet housing project for safety concerns," according to the member station. The residents have now been informed that the 346-unit complex is set to be demolished. "Residents have been provided vouchers for temporary hotel living until their homes are done being cleaned. The residents will return to their homes for a few more months until vouchers for permanent housing are made available by the U.S. Department of Housing and Urban Development." © 2016 npr
By CATHERINE SAINT LOUIS In seven countries that recently experienced Zika outbreaks, there were also sharp increases in the numbers of people suffering from a form of temporary paralysis, researchers reported Wednesday. The analysis, published online in The New England Journal of Medicine, adds to substantial evidence that Zika infections — even asymptomatic ones — may bring on a paralysis called Guillain-Barré syndrome. The syndrome can be caused by a number of other factors, including infection with other viruses. Researchers studying the Zika epidemic in French Polynesia had estimated that roughly 1 in 4,000 people infected with the virus could develop the syndrome. The Centers for Disease Control and Prevention has said that the Zika virus is “strongly associated” with Guillain-Barré, but has stopped short of declaring it a cause of the condition. The new data suggest a telling pattern: Each country in the study saw unusual increases in Guillain-Barré that coincided with peaks in Zika infections, the researchers concluded. “It’s pretty obvious that in all seven sites there is a clear relationship,” said Dr. Marcos A. Espinal, the study’s lead author and the director of communicable diseases at the Pan American Health Organization, which collected data on confirmed and suspected cases of Zika infection and on the incidence of Guillain-Barré. “Something is going on.” In Venezuela, officials expected roughly 70 cases of Guillain-Barré from December 2015 to the end of March 2016, as mosquitoes were spreading the virus. Instead, there were 684 cases. Similarly, during five months in which the Zika virus was circulating in Colombia, officials recorded 320 cases of Guillain-Barré when there should have been about 100. From September 2015 to March 2016, while Zika infections peaked in El Salvador, cases of Guillain-Barré doubled to 184 from 92. © 2016 The New York Times Company
Keyword: Movement Disorders
Link ID: 22618 - Posted: 09.01.2016
By JAMES GORMAN Who’s a good dog? Well, that depends on whom you’re asking, of course. But new research suggests that the next time you look at your pup, whether Maltese or mastiff, you might want to choose your words carefully. “Both what we say and how we say it matters to dogs,” said Attila Andics, a research fellow at Eotvos Lorand University in Budapest. Dr. Andics, who studies language and behavior in dogs and humans, along with Adam Miklosi and several other colleagues, reported in a paper to be published in this week’s issue of the journal Science that different parts of dogs’ brains respond to the meaning of a word, and to how the word is said, much as human brains do. Photo A dog waiting for its brain activity to be measured in a magnetic resonance imaging machine for research reported in the journal Science. Credit Enik Kubinyi As with people’s brains, parts of dogs’ left hemisphere react to meaning and parts of the right hemisphere to intonation — the emotional content of a sound. And, perhaps most interesting to dog owners, only a word of praise said in a positive tone really made the reward system of a dog’s brain light up. The experiment itself was something of an achievement. Dr. Andics and his colleagues trained dogs to enter a magnetic resonance imaging machine and lie in a harness while the machine recorded their brain activity. A trainer spoke words in Hungarian — common words of praise used by dog owners like “good boy,” “super” and “well done.” The trainer also tried neutral words like “however” and “nevertheless.” Both the praise words and neutral words were offered in positive and neutral tones. The positive words spoken in a positive tone prompted strong activity in the brain’s reward centers. All the other conditions resulted in significantly less action, and all at the same level. © 2016 The New York Times Company