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Barbara J. King Last Friday in the Washington Post, Charles Krauthammer asked which contemporary practices will be deemed "abominable" in the future, in the way that we today think of human enslavement. He then offered his own opinion: "I've long thought it will be our treatment of animals. I'm convinced that our great-grandchildren will find it difficult to believe that we actually raised, herded and slaughtered them on an industrial scale — for the eating." Krauthammer goes on to predict that meat-eating will become "a kind of exotic indulgence," because "science will find dietary substitutes that can be produced at infinitely less cost and effort." I don't often agree with Krauthammer's views, and his animal column is no exception. His breezy attitude on animal biomedical testing does animals no favors. (It's perhaps only fair to note that I have similar concerns about Alva's conclusions on animal testing from his 13.7 post published that same day.) But, still, Krauthammer does a terrific job of awakening people to many issues related to animals' suffering. And he's not alone. On April 17, I joined other scientists and activists on the radio show To the Point hosted by Warren Olney, to discuss this question: Is Animal Liberation Going Mainstream? In the 34-minute segment, we discussed the public outcry against SeaWorld's treatment of orcas, Ringling Bros.' plan to retire elephants from the circus in three years, and the rightness or wrongness of keeping animals in zoos — all issues brought up by Krauthammer in his column. © 2015 NPR
Keyword: Animal Rights
Link ID: 20935 - Posted: 05.16.2015
By Virginia Morell Hyenas long ago mastered one of the keys to Facebook success: becoming the friend of a friend. The most common large carnivore in Africa, spotted hyenas (Crocuta crocuta), are known for their socially sophisticated behaviors. They live in large, stable clans (as pictured above), which can include as many as 100 individuals. They can tell clan members apart, discriminating among their maternal and paternal kin. They’re also choosy about their pals and form tight bonds only with specific members—the friends of their friends, researchers report in the current issue of Ecology Letters. And it’s this ability to form lasting friendships—or “cohesive clusters,” as the scientists describe a triad of friends—that is most important in maintaining the animals’ social structure. To reach this conclusion, the scientists analyzed more than 50,000 observations of social interactions among spotted hyenas in Kenya’s Maasai Mara National Reserve over 20 years. They found that individual traits, including the hyena’s sex and social rank, as well as environmental factors such as the amount of rainfall and prey abundance, all play a role in the animals’ social dynamics. But the most consistently influential factor was the ability of individual hyenas to form and maintain those tight friendships. The study used a new modeling method, which the researchers say can help other scientists better understand the sociality of other species. And that includes the human animal, who, the scientists note, are also prone to “cohesive clusters,” whether living as hunter-gatherers or as users of social media. © 2015 American Association for the Advancement of Science.
Link ID: 20934 - Posted: 05.16.2015
By Jonathan Webb Science reporter, BBC News A cluster of cells in the brain of a fly can track the animal's orientation like a compass, a study has revealed. Fixed in place on top of a spherical treadmill, a fruit fly walked on the spot while neuroscientists peered into its brain using a microscope. Watching the neurons fire inside a donut-shaped brain region, they saw activity sweep around the ring to match the direction the animal was headed. Mammals have similar "head direction cells" but this is a first for flies. The findings are reported in the journal Nature. Crucially, the compass-like activity took place not only when the animal was negotiating a virtual-reality environment, in which screens gave the illusion of movement, but also when it was left in the dark. "The fly is using a sense of its own motion to pick up which direction it's pointed," said senior author Dr Vivek Jayaraman, from the Howard Hughes Medical Institute's Janelia Research Campus. In some other insects, such as monarch butterflies and locusts, brain cells have been observed firing in a way that reflects the animal's orientation to the pattern of polarised light in the sky - a "sun compass". But the newly discovered compass in the fly brain works more like the "head directions cells" seen in mammals, which rapidly set up a directional system for the animal based on landmarks in the surrounding scene. "A key thing was incorporating the fly's own movement," Dr Jayaraman told the BBC. "To see that its own motion was relevant to the functioning of this compass - that was something we could only see if we did it in a behaving animal." © 2015 BBC
Keyword: Learning & Memory
Link ID: 20933 - Posted: 05.14.2015
Thomas R. Clandinin & Lisa M. Giocomo An analysis reveals that fruit-fly neurons orient flies relative to cues in the insects' environment, providing evidence that the fly's brain contains a key component for drawing a cognitive map of the insect's surroundings. See Article p.186 Animals need accurate navigational skills as they go about their everyday lives. Many species, from ants to rodents, navigate on the basis of visual landmarks, and this is complemented by path integration, in which neuronal cues about the animal's own motion are used to track its location relative to a starting point. In mammals, these different types of navigation are integrated by neurons called head-direction cells1. In this issue, Seelig and Jayaraman2 (page 186) provide the first evidence that certain neurons in fruit flies have similar properties to head-direction cells, encoding information that orients the insects relative to local landmarks. Head-direction cells act as a neuronal compass that generates a cognitive map of an animal's environment. The activity of each head-direction cell increases as the animal faces a particular direction, with different cells preferentially responding to different directions1, 3. Rather than certain cells always responding to north, south and so on, the direction in which the cells fire is set up arbitrarily when the animal encounters new visual landmarks. The signals are then updated by self-motion cues as the animal navigates. Studying head-direction cells in mammals is challenging because of the complexity of the mammalian brain. By contrast, the small fly brain is a good model for studying neuronal activity. © 2015 Macmillan Publishers Limited.
Keyword: Learning & Memory
Link ID: 20932 - Posted: 05.14.2015
Anya Kamenetz Are you a pen-clicker? A hair-twirler? A knee-bouncer? Did you ever get in trouble for fidgeting in class? Don't hang your head in shame. All that movement may be helping you think. A new study suggests that for children with attention disorders, hyperactive movements meant better performance on a task that requires concentration. The researchers gave a small group of boys, ages 8 to 12, a sequence of random letters and numbers. Their job: Repeat back the numbers in order, plus the last letter in the bunch. All the while, the kids were sitting in a swiveling chair. For the subjects with ADHD, moving and spinning in the chair were correlated with better performance. For typically developing kids, however, it was the opposite: the more they moved, the worse they did on the task. Dustin Sarver at the University of Mississippi Medical Center is the lead author of this study. ADHD is his field, and he has a theory as to why fidgeting helps these kids. "We think that part of the reason is that when they're moving more they're increasing their alertness." That's right — increasing. The prevailing scientific theory on attention disorders holds that they are caused by chronic underarousal of the brain. That's why stimulants are prescribed as treatment. Sarver believes that slight physical movements "wake up" the nervous system in much the same way that Ritalin does, thus improving cognitive performance. © 2015 NPR
Link ID: 20931 - Posted: 05.14.2015
by Jessica Hamzelou Painful needle heading your way? A sharp intake of breath might be all that is needed to make that injection a little more bearable. When you are stressed, your blood pressure rises to fuel your brain or limbs should you need to fight or flee. But your body has a natural response for calming back down. Pressure sensors on blood vessels in your lungs can tell your brain to bring the pressure back down, and the signals from these sensors also make the brain dampen the nervous system, leaving you less sensitive to pain. This dampening mechanism might be why people with higher blood pressures appear to have higher pain thresholds. Gustavo Reyes del Paso at the University of Jaén in Spain wondered whether holding your breath – a stress-free way of raising blood pressure and triggering the pressure sensors – might also raise a person's pain threshold. To find out, he squashed the fingernails of 38 people for 5 seconds while they held their breath. Then he repeated the test while the volunteers breathed slowly. Both techniques were distracting, but the volunteers reported less pain when breath-holding than when slow breathing. Reyes del Paso thinks holding your breath might be a natural response to the expectation of pain. "Several of our volunteers told us they already do this when they are in pain," he says. But he doesn't think the trick will work for a stubbed toe or unexpected injury. You have to start before the pain kicks in, he says, for example, in anticipation of an injection. © Copyright Reed Business Information Ltd
Keyword: Pain & Touch
Link ID: 20930 - Posted: 05.14.2015
Robinson Meyer Brett Redding felt like he was out of options. “It started with little things—having trouble making eye contact,” he told me. Soon it got worse. Redding, a 28-year-old salesman in Seattle, found himself freaking out during normal, everyday conversations. He worried any time his boss wanted to talk. He would dread his regular sales calls, and the city’s booming housing market—he works in construction—seemed to make his ever-increasing meetings all the more crushing. He was suffering social anxiety, a common but debilitating mental illness. “I was afraid of losing my job because I couldn’t do it,” he says. His meetings with a therapist weren’t working, and he didn’t “want to mess with antidepressants.” “I’ve always been so social—I’ve never had issues with looking people in the eye and talking with people,” he says. That’s when Redding’s girlfriend saw an ad on Craigslist that promised an online program could help treat Redding’s social anxiety through methods proven by science. “I had nothing to lose,” he says—so he signed up. That service is now called Joyable. I first saw Joyable when an ad for it appeared in Facebook on my phone. “90 percent of our clients see their anxiety decline,” said the ad, next to a sun-glinted, bokeh-heavy photo of a blonde woman. I clicked on. Joyable’s website, full of affable sans serifs and cheery salmon rectangles, looks Pinterest-esque, at least in its design. Except its text didn’t discuss eye glasses or home decor but “evidence-based” methods shown to reduce social anxiety. I knew those phrases: “Evidence-based” is the watchword of cognitive behavioral therapy, or CBT, the treatment now considered most effective for certain anxiety disorders. Joyable dresses a psychologists’s pitch in a Bay Area startup’s clothes. © 2015 by The Atlantic Monthly Group.
Link ID: 20929 - Posted: 05.14.2015
Haroon Siddique Long-term depression in people over 50 could more than double their risk of suffering a stroke, with the risk remaining significantly higher even after the depression allays, research suggests. The US study of more than 16,000 people, which documented 1,192 strokes, found that onset of recent depression was not associated with higher stroke risk, suggesting the damage is done by depressive symptoms accumulating over time. The study’s lead author, Paola Gilsanz, from Harvard University’s TH Chan School of Public Health, said: “Our findings suggest that depression may increase stroke risk over the long term. Looking at how changes in depressive symptoms over time may be associated with strokes allowed us to see if the risk of stroke increases after elevated depressive symptoms start or if risk goes away when depressive symptoms do. We were surprised that changes in depressive symptoms seem to take more than two years to protect against or elevate stroke risk.” The research, published on Wednesday in the Journal of the American Heart Association, used data from between 1998 and 2010 from the Health and Retirement Study, which interviews a panel of representative Americans aged over 50 every two years, on their depressive symptoms, history of stroke, and stroke risk factors. Gilsanz, with colleagues from universities in Washington, California and Minnesota, and Bronx Partners for Healthy Communities, found that people with high depressive symptoms at two consecutive interviews had a 114% higher risk of suffering a first stroke, compared with people without depression at either interview. Those who had depressive symptoms at one interview but not at the next had a 66% higher risk. © 2015 Guardian News and Media Limited
Jon Hamilton When the brain needs to remember a phone number or learn a new dance step, it creates a circuit by connecting different types of neurons. But scientists still don't know how many types of neurons there are or exactly what each type does. "How are we supposed to understand the brain and help doctors figure out what schizophrenia is or what paranoia is when we don't even know the different components," says Christof Koch, president and chief scientific officer of the Allen Institute for Brain Science, a nonprofit research center in Seattle. So the institute is creating a freely available online database that will eventually include thousands of nerve cells. For now, the Allen Cell Types Database has detailed information on 240 mouse cells, including their distinctive shapes. More than 100 years ago, Golgi staining on nerve cells opened the gates to modern neuroscience. Scientists recently developed the Technicolor version of Golgi staining, Brainbow, allowing more detailed reconstructions of brain circuits. "They look like different trees," Koch says. "Some fan out at the top. Some are like a Christmas tree; they fan out at the bottom. Others are like three-dimensional fuzz balls." The database also describes each cell by the electrical pattern it generates. And eventually it will include information about which genes are expressed. Once researchers have a complete inventory of details about the brain's building blocks, they'll need to know which combinations of blocks can be connected, Koch says. After all, he says, it is these connections that make us who we are. © 2015 NPR
Keyword: Brain imaging
Link ID: 20927 - Posted: 05.14.2015
Alexandra Sifferlin Autism, already a mysterious disorder, is even more puzzling when it comes to gender differences. For every girl diagnosed with autism, four boys are diagnosed, a disparity researchers don’t yet fully understand. In a new study published in the journal Molecular Autism, researchers from the UC Davis MIND Institute tried to figure out a reason why. They looked at 112 boys and 27 girls with autism between ages 3 and 5 years old, as well as a control sample of 53 boys and 29 girls without autism. Using a process called diffusion-tensor imaging, the researchers looked at the corpus callosum — the largest neural fiber bundle in the brain — in the young kids. Prior research has shown differences in that area of the brain among people with autism. They found that the organization of these fibers was different in boys compared with girls, especially in the frontal lobes, which play a role in executive functions. “The sample size is still limited, but this work adds to growing body of work suggesting boys and girls with autism have different underlying neuroanatomical differences,” said study author Christine Wu Nordahl, an assistant professor in the UC Davis Department of Psychiatry and Behavioral Sciences, in an email. In other preliminary research presented at the International Meeting for Autism Research, or IMFAR, in Salt Lake City, the study authors showed that when girls and boys with autism are compared with typically developing boys and girls, the behavioral differences between girls with autism and the female controls are greater than the differences among the boys. Nordahl says this suggests that girls can be more severely affected than boys.
By SABRINA TAVERNISE WASHINGTON — What would make a smoker more likely to quit, a big reward for succeeding or a little penalty for failing? That is what researchers wanted to know when they assigned a large group of CVS employees, their relatives and friends to different smoking cessation programs. The answer offered a surprising insight into human behavior. Many more people agreed to sign up for the reward program, but once they were in it, only a small share actually quit smoking. A far smaller number agreed to risk the penalty, but those who did were twice as likely to quit. The trial, which was described in The New England Journal of Medicine on Wednesday, was the largest yet to test whether offering people financial incentives could lead to better health. It used theories about human decision making that have been developed in psychology and economics departments over several decades and put them into practice with more than 2,500 people who either worked at CVS Caremark, the country’s largest drugstore chain by sales, or were friends or relatives of those employees. Researchers found that offering incentives was far more effective in getting people to stop smoking than the traditional approach of giving free smoking cessation help, such as counseling or nicotine replacement therapy like gum, medication or patches. But they also found that requiring a $150 deposit that would be lost if the person failed to stay off cigarettes for six months nearly doubled the chances of success. “Adding a bit of a stick was much better than a pure carrot,” said Dr. Scott Halpern, deputy director of the Center for Health Incentives and Behavioral Economics at the University of Pennsylvania School of Medicine, who led the study. © 2015 The New York Times Company
Keyword: Drug Abuse
Link ID: 20925 - Posted: 05.14.2015
Alison Abbott It is only when you read the words that Andreas Vesalius wrote as an angry young man in the 1540s that you get a feeling for what drove him to document every scrap of human anatomy his eye could see. His anger was directed at Galen, the second-century physician whose anatomical teachings had been held as gospel for more than a millennium. Roman Empire law had barred Galen from dissecting humans, so he had extrapolated as best he could from animal dissections — often wrongly. Human dissections were also banned in most of sixteenth-century Europe, so Vesalius travelled to wherever they were allowed. He saw Galen's errors and dared to report them, most explicitly in his seven-volume De Humani Corporis Fabrica (On the Fabric of the Human Body), which he began aged 24, working with some of the best art professionals of the time. His mission to learn through direct and systematic observation marked the start of a new way of doing science. In Brain Renaissance, neuroscientists Marco Catani and Stefano Sandrone present a translation from the Latin of the Fabrica's last volume, which focuses on the brain. Through it we can appreciate Vesalius's extraordinary attention to detail, and his willingness to believe his eyes, even when what he saw contradicted established knowledge. We learn his anatomical vocabulary. For example, he called the rounded surface protuberances near the brain stem “buttocks” and “testes”; these are now known as the inferior and superior colliculi, or 'little hills', which process sound and vision. © 2015 Macmillan Publishers Limited.
Keyword: Brain imaging
Link ID: 20924 - Posted: 05.14.2015
By Emily Underwood We’ve all heard how rats will abandon a sinking ship. But will the rodents attempt to save their companions in the process? A new study shows that rats will, indeed, rescue their distressed pals from the drink—even when they’re offered chocolate instead. They’re also more likely to help when they’ve had an unpleasant swimming experience of their own, adding to growing evidence that the rodents feel empathy. Previous studies have shown that rats will lend distressed companions a helping paw, says Peggy Mason, a neurobiologist at the University of Chicago in Illinois who was not involved in the work. In a 2011 study, for example, Mason and colleagues showed that if a rat is trapped in a narrow plastic tube, its unrestrained cagemate will work on the latch until it figures out how to spring the trap. Skeptics, however, have suggested that the rodents help because they crave companionship—not because their fellow rodents were suffering. The new study, by researchers at the Kwansei Gakuin University in Japan, puts those doubts to rest, Mason says. For their test of altruistic behavior, the team devised an experimental box with two compartments divided by a transparent partition. On one side of the box, a rat was forced to swim in a pool of water, which it strongly disliked. Although not at risk of drowning—the animal could cling to a ledge—it did have to tread water for up to 5 minutes. The only way the rodent could escape its watery predicament was if a second rat—sitting safe and dry on a platform—pushed open a small round door separating the two sides, letting it climb onto dry land. © 2015 American Association for the Advancement of Science
Rob Stein The seasons appear to influence when certain genes are active, with those associated with inflammation being more active in the winter, according to new research released Tuesday. A study involving more than 16,000 people found that the activity of about 4,000 of those genes appears to be affected by the season, researchers reported in the journal Nature Communications. The findings could help explain why certain diseases are more likely than others to strike for the first time during certain seasons, the researchers say. "Certain chronic diseases are very seasonal — like seasonal affective disorder or cardiovascular disease or Type 1 diabetes or multiple sclerosis or rheumatoid arthritis," says John Todd, a geneticist at the University of Cambridge who led the research. "But people have been wondering for decades what the explanation for that is." Todd and his colleagues decided to try to find out. They analyzed the genes in cells from more than 16,000 people in five countries, including the United States and European countries in the Northern Hemisphere, and Australia in the Southern Hemisphere. And they spotted the same trend — in both hemispheres, and among men as well as women. "It's one of those observations where ... the first time you see it, you go, 'Wow, somebody must have seen this before,' " Todd says. Not all young girls avoid dirt. Hannah Rose Akerley, 7, plays in a gigantic lake of mud at the annual Mud Day event in Westland, Mich., last July. © 2015 NPR
By ANDREW POLLACK A study of an obesity drug has ended after the manufacturer released early and ultimately misleading data, researchers said on Tuesday. The company, Orexigen Therapeutics, disclosed in March that early results from a clinical trial of its drug Contrave had shown a 41 percent reduction in the risk of heart attacks, strokes and death from cardiovascular causes. Orexigen’s stock shot up, and the information no doubt helped lift sales of Contrave. But the academic researchers who oversaw the study said on Tuesday that Orexigen had violated an agreement that the early results were not going to be shared widely, even within the company. Moreover, as participants in the trial were followed for a longer period of time, the benefit of the drug in reducing cardiovascular risks vanished. The researchers, in a news release issued by the Cleveland Clinic, said they took the unusual step of terminating the study and releasing the more updated results. “We felt it was unacceptable to allow misleading interim data to be in the public domain and be acted upon by patients and providers,” Dr. Steven Nissen, chairman of cardiovascular medicine at the Cleveland Clinic and head of the trial’s steering committee, said in an interview. He said Orexigen had “acted improperly and unethically in violating the data access agreement” and the premature release of data had made it difficult to continue the study. It’s unlikley that patients would want to stay in the trial and risk getting a placebo if they thought the drug, which is already available on the market, could reduce their risk of heart attacks. © 2015 The New York Times Company
Link ID: 20921 - Posted: 05.13.2015
By Melissa Mancini, Many veterans are turning to marijuana to ease symptoms of post traumatic stress disorder, despite concerns from the medical community about how effective pot is at treating the condition. There are a "tremendous" number of testimonials from patients with post traumatic stress disorder who say dried cannabis helps them, but there is a lack of randomized, controlled trials, said Dr. Stewart Cameron, a family physician and professor at Dalhousie University's faculty of medicine. In September 2014, the College of Family Physicians of Canada released a document to help doctors decide how to use cannabis in their practices. "They strongly recommended that it not be used for PTSD," said Cameron. "They suggested it should be reserved as a third or fourth line agent in people who suffer certain types of pain." Veterans Affairs paid out $5.2 million for medical marijuana to veterans across Canada last year. Of that, $3.4 million went to veterans in Atlantic Canada. The department could not say which ailments the veterans are treating with marijuana, because Veterans Affairs doesn't track cannabis reimbursement by condition. Medical marijuana advocate Fabian Henry says most of the 500 veterans who visited his company last year were looking for authorization to use marijuana to help with post traumatic stress disorder. Henry's company, Marijuana for Trauma, connects veterans with physicians willing to authorize medical cannabis. The organization has helped hundreds of veterans fill out forms for medical pot reimbursement from Veterans Affairs Canada. Marijuana for Trauma calls cannabis "a natural choice medicine" and says it's "proven to be effective in 85 per cent of those who suffer with PTSD." But Canadian medical authorities are far from assigning such a high efficacy rate to the drug. ©2015 CBC/Radio-Canada.
Sarah Boseley Health editor Psychiatric drugs do more harm than good and the use of most antidepressants and dementia drugs could be virtually stopped without causing harm, an expert on clinical trials argues in a leading medical journal. The views expressed in a British Medical Journal debate by Peter Gøtzsche, professor and director of the Nordic Cochrane Centre in Denmark, are strongly opposed by many experts in mental health. However, others say the debate around the use of psychiatric drugs is important and acknowledge that there has been overuse of antipsychotics to quieten aggressive patients with dementia. Gøtzsche says more than half a million people over the age of 65 die as a result of the use of psychiatric drugs every year in the western world. “Their benefits would need to be colossal to justify this, but they are minimal,” he writes. He claims that trials carried out with funding from drug companies into the efficacy of psychiatric drugs have almost all been biased, because the patients involved have usually been on other medication first. They stop their drugs and often experience a withdrawal phase prior to starting the trial drug, which then appears to have a big benefit. He also claims that deaths from suicide in clinical trials are under-reported. In trials of the modern antidepressants fluoxetine and venlafaxine, says Gøtzsche, it takes only a few extra days for depression in the placebo group – given dummy pills – to lift as much as in the group given the drugs. He argues that there is spontaneous remission of the disease over time. © 2015 Guardian News and Media Limited
By Gareth Cook Much has been written on the wonders of human memory: the astounding feats of recall, the way memories shape our identity and are shaped by them, memory as a literary theme and a historical one. But what of forgetting? This is the topic of a new book by Douwe Draaisma, author of The Nostalgia Factory and a professor of the history of psychology at the University of Groningen. In Forgetting, Draaisma considers dreaming, amnesia, dementia and all of the ways that our minds — and lives — are shaped by memory’s opposite. He answered questions from Mind Matters editor Gareth Cook. What is your earliest memory and why, do you suppose, have you not forgotten it? Quite a few early memories in the Netherlands involve bicycles, and mine is no exception. I was two-and-a-half years old when my aunts walked my mother to the train station. They had taken a bike along to transport her bags. I was sitting on the back of the bike. Suddenly the whole procession came to a halt when my foot got caught between the spokes. I’m pretty sure this memory is accurate, since I had to see a doctor and there is a dated medical record. It’s a brief, snapshot-like memory, black-and-white. I don’t remember any pain, but I do remember the consternation among my mom and her sisters. Looking back on this memory from a professional perspective, I would say that it has the flash-like character typical for first memories from before age 3; ‘later’ first memories are usually a bit longer and more elaborate. It also fits the pattern of being about pain and danger. Roughly three in four first memories are associated with negative emotions. This may have an evolutionary origin: I never again had my foot between the spokes. And neither have any of my children. © 2015 Scientific American
Keyword: Learning & Memory
Link ID: 20918 - Posted: 05.13.2015
Jessica Hamzelou Don't be too hard on them. Amoebas that weasel their way into our brains and chow down on our grey matter aren't welcome, but it's how our immune system reacts that's really lethal. Setting the story straight could help us deal with them better. Brain-eating amoebas (Naegleria fowleri) are found in warm freshwater pools around the world, feeding on bacteria. If someone swims in one of these pools and gets water up their nose, the amoeba heads for the brain in search of a meal. Once there, it starts to destroy tissue by ingesting cells and releasing proteins that make other cells disintegrate. The immune system launches a counter-attack by flooding the brain with immune cells, causing inflammation and swelling. It seldom works: of the 132 people known to have been infected in the US since 1962, only three survived. Brain-eating amoeba infections are more common elsewhere. "In Pakistan, we have something like 20 deaths per year," says Abdul Mannan Baig at the Aga Khan University in Karachi. There is no standard treatment. Doctors in the US have recently started trying to kill the amoebas with miltefosine, a drug known to work on the leishmaniasis parasite. Mannan thinks they should take a different approach, because the immune response may be more damaging than the amoeba itself. The problem is that enzymes released by the immune cells can also end up destroying brain tissue. And the swelling triggered by the immune system eventually squashes the brainstem, fatally shutting off communication between the body and the brain. © Copyright Reed Business Information Ltd
Link ID: 20917 - Posted: 05.13.2015
By C. CLAIBORNE RAY Q. I heard that people can’t look at a color in one room and then pick it out of a set of similar colors in the next room. But there are people with perfect pitch, so are there people with “perfect hue”? A. “The short answer is no,” said Mark D. Fairchild, director of the program of color science at the Munsell Color Science Laboratory of Rochester Institute of Technology. “Color is almost always judged relative to other colors,” Dr. Fairchild said, and the human ability to remember colors over any period of time, or even from room to room, is extremely poor. “Based on memory alone, we can probably reliably identify tens of colors, with some people perhaps able to study hard and get up to a hundred or so,” he said. “If we were to learn a systematic way to scale colors, we might be able to get up to several hundred.” If colors are compared side by side, however, “then we can easily distinguish several thousand colors, and some estimate more than a million,” Dr. Fairchild said. Such ability is somewhat analogous to differentiating tones in hearing, he said. Almost everyone can distinguish tones when they are compared in close succession, he said, but only a very small percentage of people have what is called perfect pitch or absolute pitch: the ability to recall and identify tones after a considerable period of time, without a reference tone for comparison. “Unfortunately, color appearance seems to be even more difficult to remember,” Dr. Fairchild said, “to the point that we don’t speak of anyone as having perfect hue.” © 2015 The New York Times Company
Link ID: 20916 - Posted: 05.13.2015