By Darryl Fears Flushed down toilets, poured down sinks and excreted in urine, a chemical component in the pill wafts into sewage systems and ends up in various waterways where it collects in fairly heavy doses. That's where fish soak it up. A recent survey by the U.S. Geological Survey found that fish exposed to a synthetic hormone called 17a-ethinylestradiol, or EE2, produced offspring that struggled to fertilize eggs. The grandchildren of the originally exposed fish suffered a 30 percent decrease in their fertilization rate. The authors mulled the impact of what they discovered and decided it wasn't good. "If those trends continued, the potential for declines in overall population numbers might be expected in future generations," said Ramji Bhandari, a University of Missouri assistant research professor and a visiting scientist at USGS. "These adverse outcomes, if shown in natural populations, could have negative impacts on fish inhabiting contaminated aquatic environments." The study, with Bhandari as lead author, also determined that the chemical BPA, used widely in plastics, had a similar effect on the small Japanese medaka fish used for the research. The medaka was chosen because it reproduces quickly so that scientists can see results of subsequent generations faster than slow reproducing species such as smallmouth bass.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 21760 - Posted: 01.08.2016

By Emily Underwood Lumos Labs, the company that produces the popular “brain-training” program Lumosity, yesterday agreed to pay a $2 million settlement to the Federal Trade Commission (FTC) for running deceptive advertisements. Lumos had claimed that its online games can help users perform better at work and in school and stave off cognitive deficits associated with serious diseases such as Alzheimer’s, traumatic brain injury, and post-traumatic stress. The $2 million settlement will be used to compensate Lumosity consumers who were misled by false advertising, says Michelle Rusk, a spokesperson with FTC in Washington, D.C. The company will also be required to provide an easy way to cancel autorenewal billing for the service, which includes online and mobile app subscriptions, with payments ranging from $14.95 monthly to lifetime memberships for $299.95. Before consumers can access the games, a pop-up screen will alert them to FTC’s order and allow them to avoid future billing, Rusk says. The action is part of a larger crackdown on companies selling products that purportedly enhance memory or provide some other cognitive benefit, Rusk says. For some time now, FTC has been “concerned about some of the claims we’re seeing out there,” particularly those from companies like Lumos that suggest their games can reduce the effects of conditions such as dementia, she says. After evaluating the literature on Lumos's products, and the broader research on the benefits of brain-training games, “our assessment was they didn’t have adequate science for the claims that they’re making,” she says. © 2016 American Association for the Advancement of Science

Keyword: Learning & Memory; Intelligence
Link ID: 21759 - Posted: 01.07.2016

By Stephani Sutherland A technique called optogenetics has transformed neuroscience during the past 10 years by allowing researchers to turn specific neurons on and off in experimental animals. By flipping these neural switches, it has provided clues about which brain pathways are involved in diseases like depression and obsessive-compulsive disorder. “Optogenetics is not just a flash in the pan,” says neuroscientist Robert Gereau of Washington University in Saint Louis. “It allows us to do experiments that were not doable before. This is a true game changer like few other techniques in science.” Since the first papers were published on optogenetics in the mid-aughts some researchers have mused about one day using optogenetics in patients, imagining the possibility of an off-switch for depression, for instance. The technique, however, would require that a patient submit to a set of highly invasive medical procedures: genetic engineering of neurons to insert molecular switches to activate or switch off cells, along with threading of an optical fiber into the brain to flip those switches. Spurred on by a set of technical advances, optogenetics pioneer Karl Deisseroth, together with other Stanford University researchers, has formed a company to pursue optogenetics trials in patients within the next several years—one of several start-ups that are now contemplating clinical trials of the technique. Circuit Therapeutics, founded in 2010, is moving forward with specific plans to treat neurological diseases. (It also partners with pharmaceutical companies to help them use optogenetics in animal research to develop novel drug targets for human diseases.) © 2016 Scientific America

Keyword: Pain & Touch
Link ID: 21758 - Posted: 01.07.2016

By Anahad O'Connor David Ludwig often uses an analogy when he talks about weight loss: Human beings are not toaster ovens. If we were, then the types of calories we consumed would not matter, and calorie counting would be the most effective way to lose weight. Dr. Ludwig, an obesity expert and professor of nutrition at the Harvard T.H. Chan School of Public Health, argues that weight gain begins when people eat the wrong types of food, which throws their hormones out of whack and sets off a cycle of cravings, hunger and bingeing. In his new book, “Always Hungry?,” he argues that the primary driver of obesity today is not an excess of calories per se, but an excess of high glycemic foods like sugar, refined grains and other processed carbohydrates. Recently, we caught up with Dr. Ludwig to talk about which foods act as “fertilizer for fat cells,” why he thinks the conventional wisdom on weight loss is all wrong, and long-term strategies for weight loss. Here are edited excerpts from our conversation. What is the basic message of your book? The basic premise is that overeating doesn’t make you fat. The process of getting fat makes you overeat. It may sound radical, but there’s literally a century of science to support this point. Simply cutting back on calories as we’ve been told actually makes the situation worse. When we cut back on calories, our body responds by increasing hunger and slowing metabolism. It responds in an effort to save calories. And that makes weight loss progressively more and more difficult on a standard low calorie diet. It creates a battle between mind and metabolism that we’re doomed to lose. But we’ve all been told that obesity is caused by eating too much. Is that not the case? We think of obesity as a state of excess, but it’s really more akin to a state of starvation. If the fat cells are storing too many calories, the brain doesn’t have access to enough to make sure that metabolism runs properly. So the brain makes us hungry in an attempt to solve that problem, and we overeat and feel better temporarily. © 2016 The New York Times Company

Keyword: Obesity
Link ID: 21757 - Posted: 01.07.2016

Katherine Hobson Pregnant women worry about all kinds of things. Can I drink alcohol? (No.) Can I take antidepressants? (Maybe.) Can I do the downward dog? (Yes.) Now there's one less thing to fret about: harm to the baby when the mother takes birth control pill right before conceiving, or during the first few months of pregnancy. According to a study covering more than 880,000 births in Denmark, the overall rate of birth defects was consistent for women who had never taken the pill at all, for those who had used it before getting pregnant and for those who continued on the pill in early pregnancy. (There were about 25 birth defects per 1,000 births for all groups.) The study is important because so many women take the pill – about 16 percent of women of childbearing age in the U.S. When used perfectly, the failure rate of the pill is less than 1 percent, but that jumps to 9 percent under typical use because of missed pills, drug interactions or illness. That means a lot of embryos are exposed to the hormones used in the pill, which can linger for a few months after a woman stops taking it. "Our findings are really reassuring," says Brittany Charlton, an author of the study and a researcher in the Harvard T.H. Chan School of Public Health's epidemiology department. The results also confirm most of the previous research, which has pointed to no overall increase in major birth defects, she says. This study, published in the medical journal BMJ, used national birth, patient and prescription registry data to track contraceptive prescriptions among women who gave birth, then looked at whether birth defects were associated with pill use. © 2016 npr

Keyword: Development of the Brain; Sexual Behavior
Link ID: 21756 - Posted: 01.07.2016

Children conceived via infertility treatments are no more likely to have a developmental delay than children conceived without such treatments, according to a study by researchers at the National Institutes of Health, the New York State Department of Health and other institutions. The findings, published online in JAMA Pediatrics, may help to allay longstanding concerns that conception after infertility treatment could affect the embryo at a sensitive stage and result in lifelong disability. The authors found no differences in developmental assessment scores of more than 1,800 children born to women who became pregnant after receiving infertility treatment and those of more than 4,000 children born to women who did not undergo such treatment. “When we began our study, there was little research on the potential effects of conception via fertility treatments on U.S. children,” said Edwina Yeung, Ph.D., an investigator in the Division of Intramural Population Health Research at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). “Our results provide reassurance to the thousands of couples who have relied on these treatments to establish their families.” Also taking part in the study were researchers from the University at Albany, New York; the New York State Department of Health, also in Albany; and CapitalCare Pediatrics in Troy, New York. The Upstate KIDS study enrolled infants born to women in New York State (except for New York City) from 2008 to 2010. Parents of infants whose birth certificates indicated infertility treatment were invited to enroll their children in the study, as were all parents of twins and other multiples. The researchers also recruited roughly three times as many singletons not conceived via infertility treatment. Four months after giving birth, the mothers indicated on a questionnaire the type of infertility treatment they received:

Keyword: Development of the Brain
Link ID: 21755 - Posted: 01.07.2016

Laura Sanders It didn’t take a lot of brainpower to come up with the name for a nerve cell that looks like a bushy, round tangle of fibers perched atop a nucleus. Meet the shrub cell. This botanically named cell, discovered in the brains of adult mice, made its formal debut in the Nov. 27 Science. The newly described cell lives in a particular nervy neighborhood — an area called layer 5 in the part of the brain that handles incoming visual information. Xiaolong Jiang of Baylor College of Medicine in Houston and colleagues defined shrub cells and other newcomers by their distinct shapes, their particular connections to other nerve cells or their similarities to nerve cells found elsewhere. Joining shrub cells are the freshly named horizontally elongated cells, deep-projecting cells, L5 basket cells and L5 neurogliaform cells. Each is an interneuron, a middleman that connects nerve cells to each other. The finding highlights the stunning variety of shapes and wiring patterns of cells in the brain. Citations X. Jiang et al. Principles of connectivity among morphologically defined cell types in adult neocortex. Science. Vol. 350, November 27, 2015. doi: 10.1126/science.aac9462 © Society for Science & the Public 2000 - 2015.

Keyword: Development of the Brain
Link ID: 21754 - Posted: 01.07.2016

by Helen Thompson Earth’s magnetic field guides shark movement in the open ocean, but scientists had always suspected that sharks might also get their directions from an array of other factors, including smell. To sniff out smell’s role, biologists clogged the noses of leopard sharks (Triakis semifasciata), a Pacific coastal species that makes foraging trips out to deeper waters. Researchers released the sharks out at sea and tracked their path back to the California coast over four hours. Sharks with an impaired sense of smell only made it 37.2 percent of the way back to shore, while unimpaired sharks made it 62.6 percent of the way back to shore. The study provides the first experimental evidence that smell influences a shark’s sense of direction, the team writes January 6 in PLOS ONE. The animals may be picking up on chemical gradients produced by food sources that live on the coast. © Society for Science & the Public 2000 - 2015.

Keyword: Chemical Senses (Smell & Taste); Animal Migration
Link ID: 21753 - Posted: 01.07.2016

By Debra W. Soh What should parents do if their little boy professes an intense desire to be a girl? Or if their daughter comes home from kindergarten and says she wants to be a boy? In recent years the dominant thinking has changed dramatically regarding children’s gender dysphoria. Previously, parents might hope that it would be a passing phase, as it usually is. But now they are under pressure from gender-identity politics, which asserts that children as young as 5 should be supported in wanting to live as the opposite sex. Any attempts to challenge this approach are deemed intolerant and oppressive. I myself was a gender-dysphoric child who preferred trucks and Meccano sets to Easy-Bake Ovens. I detested being female and all of its trappings. Yet when I was growing up in the 1980s, the concept of helping children transition to another sex was completely unheard of. My parents allowed me to wear boys’ clothing and shave my head, to live as a girl who otherwise looked and behaved like a boy. I outgrew my dysphoria by my late teens. Looking back, I am grateful for my parents’ support, which helped me work things out. Since then, research has established best-treatment practices for adolescents and adults with gender dysphoria: full transitioning, which includes treatment with hormones to suppress puberty and help the individual develop breasts or facial hair, as well as gender-reassignment surgery. But prepubescent children who identify with the opposite sex are another matter entirely. How best to deal with them has become so politicized that sexologists, who presumably would be able to determine the healthiest approach, are extremely reluctant to get involved. They have seen what happens when they deviate from orthodoxy. ©2016 Dow Jones & Company, Inc

Keyword: Sexual Behavior; Development of the Brain
Link ID: 21752 - Posted: 01.05.2016

Patricia Neighmond Losing your ability to think and remember is pretty scary. We know the risk of dementia increases with age. But if you have memory lapses, you probably needn't worry. There are pretty clear differences between signs of dementia and age-related memory loss. After age 50, it's quite common to have trouble remembering the names of people, places and things quickly, says Dr. Kirk Daffner, chief of the division of cognitive and behavioral neurology at Brigham and Women's Hospital in Boston. The brain ages just like the rest of the body. Certain parts shrink, especially areas in the brain that are important to learning, memory and planning. Changes in brain cells can affect communication between different regions of the brain. And blood flow can be reduced as arteries narrow. Simply put, this exquisitely complex organ just isn't functioning like it used to. Forgetting the name of an actor in a favorite movie, for example, is nothing to worry about. But if you forget the plot of the movie or don't remember even seeing it, that's far more concerning, Daffner says. When you forget entire experiences, he says, that's "a red flag that something more serious may be involved." Forgetting how to operate a familiar object like a microwave oven or forgetting how to drive to the house of a friend you've visited many times before can also be signs something is wrong. © 2016 npr

Keyword: Learning & Memory; Development of the Brain
Link ID: 21751 - Posted: 01.05.2016

A 25-year-old former college football player showed signs of a type of brain degeneration from repeated trauma, say researchers who described the autopsy-confirmed case. Chronic traumatic encephalopathy (CTE) is a neurodegenerative disorder associated with repetitive head impacts. Symptoms may include memory loss, impaired judgment, depression and progressive dementia. CTE can only be diagnosed after death by examining the brain. Monday's issue of JAMA Neurology includes a letter describing CTE in a 25-year-old man born with a heart valve disorder. He died of cardiac arrest secondary to a heart infection after playing football for 16 years and experiencing an estimated more than 10 concussions while playing. Dr. Ann McKee and Dr. Jesse Mez of Boston University School of Medicine ran neuropsychological tests on the man when he showed symptoms a year before his death, and then conducted an autopsy, reviewed his medical records and interviewed family members. "Focal lesions of CTE have been found in athletes as young as 17 years; however, widespread CTE pathology, as found in this case, is unusual in such a young football player," they wrote. To their knowledge, it's the first such case to include neuropsychological testing to document the type of cognitive issues with CTE. In this case, the athlete started playing football when he was six, including three years of college football as a defensive linebacker. His first concussion occurred at age eight. ©2015 CBC/Radio-Canada.

Keyword: Brain Injury/Concussion
Link ID: 21750 - Posted: 01.05.2016

By Melissa Healy A new study finds that policies on defining brain death vary from hospital to hospital and could result in serious errors. Since 2010, neurologists have had a clear set of standards and procedures to distinguish a brain-dead patient from one who might emerge from an apparent coma. But when profoundly unresponsive patients are rushed to hospitals around the nation, the physicians who make the crucial call are not always steeped in the diagnostic fine points of brain death and the means of identifying it with complete confidence. State laws governing the diagnosis of brain death vary widely. Some states allow any physician to make the diagnosis, while others dictate the level of specialty a physician making the call must have. Some require that a second physician confirm the diagnosis or that a given period of time elapse. Others make no such demands. Given these situations, hospital policies can be invaluable guides for physicians, hospital administrators and patients’ families. In the absence of consistent physician expertise or legal requirements, hospital protocols can translate a scientific consensus into a step-by-step checklist. That would help ensure that no one who is not brain-dead is denied further care or considered a potential organ donor and that the deceased and their families would have every opportunity to donate organs.

Keyword: Consciousness
Link ID: 21749 - Posted: 01.05.2016

Jon Hamilton There's growing evidence that a lack of sleep can leave the brain vulnerable to Alzheimer's disease. "Changes in sleep habits may actually be setting the stage" for dementia, says Jeffrey Iliff, a brain scientist at Oregon Health & Science University in Portland. The brain appears to clear out toxins linked to Alzheimer's during sleep, Iliff explains. And, at least among research animals that don't get enough solid shut-eye, those toxins can build up and damage the brain. Iliff and other scientists at OHSU are about to launch a study of people that should clarify the link between sleep problems and Alzheimer's disease in humans. It has been clear for decades that there is some sort of link. Sleep disorders are very common among people with Alzheimer's disease. For a long time, researchers thought this was simply because the disease was "taking out the centers of the brain that are responsible for regulating sleep," Iliff says. But two recent discoveries have suggested the relationship may be more complicated. The first finding emerged in 2009, when researchers at Washington University in St. Louis showed that the sticky amyloid plaques associated with Alzheimer's develop more quickly in the brains of sleep-deprived mice. Then, in 2013, Iliff was a member of a team that discovered how a lack of sleep could be speeding the development of those Alzheimer's plaques: A remarkable cleansing process takes place in the brain during deep sleep, at least in animals. What happens, Iliff says, is "the fluid that's normally on the outside of the brain — cerebrospinal fluid, it's a clean, clear fluid — it actually begins to recirculate back into and through the brain along the outsides of blood vessels." This process, via what's known as the glymphatic system, allows the brain to clear out toxins, including the toxins that form Alzheimer's plaques, Iliff says. © 2016 npr

Keyword: Sleep; Alzheimers
Link ID: 21748 - Posted: 01.04.2016

By ALAN SCHWARZ DELRAY BEACH, Fla. — Three shaky months into recovery from heroin addiction, Dariya Pankova found something to ease her withdrawal. A local nonalcoholic bar sold a brewed beverage that soothed her brain and body much as narcotics had. A perfect solution — before it backfired. Ms. Pankova grew addicted to the beverage itself. She drank more and more, awakened her cravings for the stronger high of heroin, and relapsed. Only during another stay in rehab did Ms. Pankova learn that the drink’s primary ingredient, a Southeast Asian leaf called kratom, affects the brain like an opiate and can be addictive, too. “It’s preying on the weak and the broken,” said Ms. Pankova, 23, a Brooklyn native who received treatment in Delray Beach. “It’s a mind-altering substance, so people like me who are addicts and alcoholics, they think just because it’s legal, it’s fine. It’s a huge epidemic down here, and it’s causing a lot of relapses.” Some users embrace kratom as a natural painkiller and benign substitute for more dangerous substances that, in most states, is legal. But its growing popularity and easy availability are raising concerns among substance abuse experts and government officials who say it is being furtively marketed as a way out of addiction, even though it is itself addictive. Worse, some of those experts say, kratom can lead some addicts back to heroin, which is cheaper and stronger. “It’s a fascinating drug, but we need to know a lot more about it,” said Dr. Edward W. Boyer, a professor of emergency medicine at the University of Massachusetts Medical School and a co-author of several scientific articles on kratom. “Recreationally or to self-treat opioid dependence, beware — potentially you’re at just as much risk” as with an opiate. Concern is particularly high in South Florida, where a rising concentration of drug-treatment providers has coincided with the sprouting of kratom bars. But kratom is now available around the country. © 2016 The New York Times Company

Keyword: Drug Abuse
Link ID: 21747 - Posted: 01.04.2016

By Melinda Wenner Moyer There's a reason your mother told you to look people in the eye when you talk to them: eye contact conveys important social cues. Yet when someone holds your gaze for more than a few seconds, the experience can take on a different tenor. New work elucidates the factors that affect whether we like or loathe locking eyes for a lengthy period. Researchers have long known that eye contact is an important social signal. Our recognition of its import may even be hardwired. One study found that five-day-old babies prefer looking at faces that make direct eye contact compared with faces that have an averted gaze. “Eye contact provides some of the strongest information during a social interaction,” explains James Wirth, a social psychologist now at Ohio State University at Newark, because it conveys details about emotions and intentions. (Lack of eye contact is one of the early signs of autism in infants and toddlers.) The power of eye contact is so great that, according to a 2010 study co-authored by Wirth, if someone avoids your gaze for even a short period, you may feel ostracized. But what determines how we feel about prolonged eye contact? One recent study explored this question. In research presented in May 2015 at the Vision Sciences Society conference, psychologist Alan Johnston and his colleagues at University College London collected information from more than 400 volunteers about their personalities. Then the subjects indicated their comfort level while watching video clips of actors who appeared to be looking directly at them for varying lengths of time. © 2016 Scientific American

Keyword: Autism; Emotions
Link ID: 21746 - Posted: 01.04.2016

By NICHOLAS WADE After decades of disappointingly slow progress, researchers have taken a substantial step toward a possible treatment for Duchenne muscular dystrophy with the help of a powerful new gene-editing technique. Duchenne muscular dystrophy is a progressive muscle-wasting disease that affects boys, putting them in wheelchairs by age 10, followed by an early death from heart failure or breathing difficulties. The disease is caused by defects in a gene that encodes a protein called dystrophin, which is essential for proper muscle function. Because the disease is devastating and incurable, and common for a hereditary illness, it has long been a target for gene therapy, though without success. An alternative treatment, drugs based on chemicals known as antisense oligonucleotides, is in clinical trials. But gene therapy — the idea of curing a genetic disease by inserting the correct gene into damaged cells — is making a comeback. A new technique, known as Crispr-Cas9, lets researchers cut the DNA of chromosomes at selected sites to remove or insert segments. Three research groups, working independently of one another, reported in the journal Science on Thursday that they had used the Crispr-Cas9 technique to treat mice with a defective dystrophin gene. Each group loaded the DNA-cutting system onto a virus that infected the mice’s muscle cells, and excised from the gene a defective stretch of DNA known as an exon. Without the defective exon, the muscle cells made a shortened dystrophin protein that was nonetheless functional, giving all of the mice more strength. The teams were led by Charles A. Gersbach of Duke University, Eric N. Olson of the University of Texas Southwestern Medical Center and Amy J. Wagers of Harvard University. © 2016 The New York Times Company

Keyword: Movement Disorders; Muscles
Link ID: 21745 - Posted: 01.02.2016

By Elizabeth Pennisi Whether foraging for food, caring for young, or defending the nest, the worker castes of carpenter ants toil selflessly for their queen and colony. Now, biologists have figured out how to make some of those worker ants labor even harder, or change their very jobs in ant society, all by making small chemical modifications to their DNA. The finding calls attention to a new source of behavioral flexibility, and drives home the idea that so-called epigenetic modifications can connect genes to the environment, linking nature to nurture. The work is “a pioneering study establishing a causal link between epigenetics and complex social behavior,” says Ehab Abouheif, an evolutionary developmental biologist at McGill University, Montreal, in Canada. “These mechanisms may extend far beyond ants to other organisms with social behavior.” Insect biologists have long debated whether the division of labor in these sophisticated species with castes is driven by colony needs or is innate. Evidence in honey bees had pointed toward a genetic difference between queens and workers. In the past several years, however, work in both honey bees and ants had indicated that epigenetic modifications—changes to DNA other than to its sequence of bases (or DNA “letters”)—influence caste choices, indicating environmental factors can be pivotal. But subsequent research about one type of change, methylation, led to contradictory conclusions. © 2016 American Association for the Advancement of Science.

Keyword: Epigenetics
Link ID: 21744 - Posted: 01.02.2016

By R. Douglas Fields We all heard the warning as kids: “That TV will rot your brain!” You may even find yourself repeating the threat when you see young eyes glued to the tube instead of exploring the real world. The parental scolding dates back to the black-and-white days of I Love Lucy, and today concern is growing amid a flood of video streaming on portable devices. But are young minds really being harmed? With brain imaging, the effects of regular TV viewing on a child's neural circuits are plain to see. Studies suggest watching television for prolonged periods changes the anatomical structure of a child's brain and lowers verbal abilities. Behaviorally, even more detrimental effects may exist: although a cause-and-effect relation is hard to prove, higher rates of antisocial behavior, obesity and mental health problems correlate with hours in front of the set. Now a new study hits the pause button on this line of thinking. The researchers conclude that the entire body of research up to now has overlooked an important confounding variable, heredity, that could call into question the conventional wisdom that TV is bad for the brain. Further study will be needed to evaluate this claim, but the combined evidence suggests we need a more nuanced attitude toward our viewing habits. To understand the argument against television, we should rewind to 2013, when a team ofresearchers at Tohoku University in Japan, led by neuroscientist Hikaru Takeuchi, first published findings from a study in which the brains of 290 children between the ages of five and 18 were imaged. The kids' TV viewing habits, ranging from zero to four hours each day, were also taken into account. © 2016 Scientific American

Keyword: Intelligence; Learning & Memory
Link ID: 21743 - Posted: 01.02.2016

By Ana Swanson Earlier this year, the famous blue-and-black (or white-and-gold) dress captivated the Internet, serving as a reminder that color is truly in the eye of the beholder. The dress was also a lesson in the power of social media, the science of shifting colors, and the fun of optical illusions. Here we present a visual story from February 27 that rounded up some of the best-known optical illusions on the Web. The Internet erupted in an energetic debate yesterday about whether an ugly dress was blue and black or white and gold, with celebrities from Anna Kendrick (white) to Taylor Swift (black) weighing in. (For the record, I’m with Taylor – never a bad camp to be in.) It sounds inane, but the dress question was actually tricky: Some declared themselves firmly in the blue and black camp, only to have the dress appear white and gold when they looked back a few hours later. Wired had the best explanation of the science behind the dress’s shifting colors. When your brain tries to figure out what color something is, it essentially subtracts the lighting and background colors around it, or as the neuroscientist interviewed by Wired says, tries to “discount the chromatic bias of the daylight axis.” This is why you can identify an apple as red whether you see it at noon or at dusk. The dress is on some kind of perceptual boundary, with a pretty even mix of blue, red and green. (Frankly, it’s just a terrible, washed out photo.) So for those who see it as white, your eyes may be subtracting the wrong background and lighting.

Keyword: Vision
Link ID: 21742 - Posted: 01.02.2016

By Mitch Leslie Male mice bequeath an unexpected legacy to their progeny. Two studies published online this week in Science reveal that sperm from the rodents carry pieces of RNAs that alter the metabolism of their offspring. The RNAs spotlighted by the studies normally help synthesize proteins, so the findings point to an unconventional form of inheritance. The results are “exciting and surprising, but not impossible,” says geneticist Joseph Nadeau of the Pacific Northwest Diabetes Research Institute in Seattle, Washington. “Impossible” is exactly how biologists once described so-called epigenetic inheritance, in which something other than a DNA sequence passes a trait between generations. In recent years, however, researchers have found many examples. A male mouse’s diet and stress level, for instance, can tweak offspring metabolism. Researchers are still trying to determine how offspring inherit a father’s metabolic attributes and physiological condition. Some evidence implicates chemical modification of DNA. Other work by neuroscientist Tracy Bale of the University of Pennsylvania Perelman School of Medicine in Philadelphia and colleagues has found that mammalian sperm pack gene-regulating molecules called microRNAs. The new work highlights a different class of RNAs, transfer RNAs (tRNAs). In one study, genomicist Oliver Rando of the University of Massachusetts Medical School in Worcester and colleagues delved into a case of epigenetic inheritance in which the progeny of mice fed a low-protein diet show elevated activity of genes involved in cholesterol and lipid metabolism. When Rando’s group analyzed sperm from the protein-deprived males, they uncovered an increased abundance of fragments from several kinds of tRNAs. The researchers concluded the sperm acquired most of these fragments while passing through the epididymis, a duct from the testicle where the cells mature. © 2016 American Association for the Advancement of Science

Keyword: Epigenetics
Link ID: 21741 - Posted: 01.02.2016