Archive for March, 2009

Scientists See the Foreshadowing of Depression in Brain Anatomy

By Eliza Strickland | March 25, 2009 3:25 pm

depressed brainPeople with a family history of depression have an altered brain anatomy, a new study says, even if they themselves have never experienced clinical depression. Brain scans showed a 28-percent thinning in the right cortex — the outer layer of the brain — in people who had a family history of depression compared with people who did not. “The difference was so great that at first we almost didn’t believe it. But we checked and re-checked all of our data, and we looked for all possible alternative explanations, and still the difference was there” [Reuters], said study coauthor Bradley Peterson.

Researchers scanned the brains of 131 individuals ranging in age from 6 to 54, about half of whom came from families with a history of depression. The team was looking specifically for abnormalities in the brain that could signal a predisposition to depression, rather than changes that may be caused by the disease [Reuters]. The cortical thinning seems to fit the definition as a warning flag. Says Peterson: “That’s what is so extraordinary. You’re seeing it two generations later, and you’re seeing it in both children and adults…. And it’s present even if those offspring themselves have not yet become ill” [The New York Times].

The cerebral cortex is largely responsible for reasoning, planning, and mood, and researchers suggest that its thinning may interfere with a person’s ability to interpret social and emotional cues from others. Interestingly, not all of the subjects with depressed family members showed thinning on both sides of their cortices; it was primarily those with thinning in the left hemisphere who had actually developed depression.

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CATEGORIZED UNDER: Health & Medicine, Mind & Brain

Scientist Smackdown: Is Chernobyl Animal Dead Zone or Post-Apocalyptic Eden?

By Eliza Strickland | March 25, 2009 11:50 am

ChernobylThe blast that shook the Chernobyl nuclear power plant more than 20 years ago, sending a highly radioactive plume of fallout into the air, still affects local populations of butterflies and bees and other insects, according to a new study. The study appears to argue against the idea put forward by previous researchers that the region around the power plant, contaminated by radiation and off limits to most humans, has become a sort of post-apocalyptic Eden [The New York Times], in which animals can live unmolested. However, the new results are stirring up controversy.

A pair of researchers conducted standard surveys in forests around Chernobyl over three springs from 2006 to 2008, noting the numbers of bumblebees, butterflies, grasshoppers, dragonflies and spider webs at points with radiation levels that varied over four orders of magnitude [The New York Times]. They found that the number of bugs declined as the radiation increased, and that even relatively low levels of radiation impacted insect populations. The researchers say insects may be particularly vulnerable because radiation is usually found in the top layer of soil, where many invertebrates spend time during either their egg, larvae, or adult phases.

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CATEGORIZED UNDER: Environment, Living World

Brain Scan Can Predict When You're Going to Screw Up

By Eliza Strickland | March 25, 2009 8:42 am

MEGBrain scans can pick up the distinct pattern of brain waves that occur when a person’s attention lapses, and can therefore predict when the person is about to make a mistake, according to a small new study.

Using magnetoencephalography (MEG), researchers monitored the oscillations in brain activity for 14 test subjects. Each student was asked to take part in monotonous test in which a random number from one to nine flashed on a screen every two seconds, and they were asked to tap a button as soon as any number except five appeared. The test was so boring that even when a five showed up, the subjects spontaneously hit the button an average of 40% of the time [BBC News].

About a second before they committed the error, brain waves in two regions spiked: alpha wave activity in the occipital region was about 25 percent greater than usual, and in the sensorimotor cortex  there was a corresponding increase in the brain’s mu wave activity.

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20 Years After Valdez Spill, Eagles Are Healthy; 7 Other Species Still Hurting

By Rachel Cernansky | March 24, 2009 6:07 pm

oiled_bird_3.jpgTwenty years have passed, and oil from the Exxon Valdez spill still taints Alaska’s shores and waters: roughly 21,000 of the original 11 million gallons remain, and have spread up to 450 miles from the spill site in Prince William Sound.

A report by the Exxon Valdez Oil Spill Trustee Council—a state and federal partnership formed to oversee ecosystem recovery efforts—lists nine species, including the bald eagle, as fully recovered, but many of the area’s fish populations remain low. Sea otters and harlequin ducks continue to die because they dig for food in the sand and release buried oil, pockets of which remain buried in small portions of the intertidal zone hard hit by the spill. Seven distinct species, including sea otters, killer whales and clams, still are considered to be “recovering” from the initial effects of the oil [Seattle Times].

The initial death toll was estimated to include 250,000 seabirds, 4,000 sea otters, 250 bald eagles, and more than 20 orca whales [National Geographic News], according to the World Wildlife Fund. The herring population, upon which many of the area’s fishermen depended, has not yet recovered. And mysteriously, the resident killer whale pod in Prince William Sound has shown signs of “unusual social breakdown.” First, several females disappeared, leading to a loss of about half the pod’s newborn calves, and [this was followed by] the highly unusual defection of one matrilineal group to a different pod, never before seen among orcas in the North Pacific. The region’s transient killer whales, meanwhile, “show no signs of recovery and continue to decline” [Los Angeles Times], according to the Trustee Council’s report.

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CATEGORIZED UNDER: Environment, Living World

Iron-Dumping Experiment Is a Bust: It Feeds Crustaceans, Doesn't Trap Carbon

By Eliza Strickland | March 24, 2009 5:09 pm

iron fertilization boatA controversial geoengineering experiment that Greenpeace campaigned against (to little avail) has concluded, and researchers say their findings deal a major blow to the geoengineering technique known as ocean fertilization. As 80beats explained in January, the researchers dumped 20 tons of iron sulfate in the ocean near Antarctica in an effort to spur enormous blooms of phytoplankton, a type of algae; researchers theorized that when that plant life died and sank to the seabed it would lock away the carbon dioxide it had absorbed while growing. They hoped that widespread use of this technique could slow global warming.

While the iron did prove an algae bloom, researchers involved in the Lohafex project found that little biomass sunk down to the sea floor. Their results, announced in a press release, suggest that iron fertilisation could not have a major impact, at least in that region of the oceans. “There’s been hope that one could remove some of the excess carbon dioxide – put it back where it came from, in a sense, because the petroleum we’re burning was originally made by the algae,” said [researcher] Victor Smetacek…. “But our results show this is going to be a small amount, almost negligible” [BBC News]. Researchers also announced the surprising reason for that result: The plankton bloom wasn’t a carbon sequestration hot spot, instead it was an all-you-can-eat marine buffet.

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UK Aims to Create "Unlimited" Supply of Synthetic Blood from Stem Cells

By Eliza Strickland | March 24, 2009 4:34 pm

blood bagA high-powered consortium in the United Kingdom has declared a push to create synthetic blood from embryonic stem cells over the next decade. “In principle, we could provide an unlimited supply of blood in this way” [BBC News], says researcher Marc Turner. Synthetic blood would be guaranteed to be free of viruses like HIV, and could also prevent shortages at blood banks, emergency rooms, and battlefield operations.

While the American biotech company Advanced Cell Technology (ACT) announced last August that they had developed a technique of creating blood from embryonic stem cells, the new UK effort has more significant institutional backing. The multimillion-pound deal involving NHS [National Health Service] Blood and Transplant, the Scottish National Blood Transfusion Service and the Wellcome Trust, the world’s biggest medical research charity, means Britain will take centre stage in the global race to develop blood made from embryonic stem cells [The Independent].

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CATEGORIZED UNDER: Health & Medicine

A Tentative New Hope for Discredited Cold Fusion

By Eliza Strickland | March 24, 2009 11:45 am

cold fusion TimeCold fusion is the dream that won’t die for some nuclear physicists. If they could replicate the nuclear reaction that powers our sun under room temperature conditions, the thinking goes, humanity would gain a clean source of nearly limitless energy. Work on cold fusion has been relegated to the margins of science since a much-hyped experiment 20 years ago was discredited, but now a new team of researchers says they’ve conducted experiments that should reinstate the field. “We have compelling evidence that fusion reactions are occurring” at room temperature [EE Times], said lead researcher Pamela Mosier-Boss, of the Space and Naval Warfare Systems Center in San Diego.

On March 23, 1989, physicists Stanley Pons and Martin Fleischmann claimed to have created fusion reactions in a tabletop experiment, at room temperature. [Watch a video of the annoucement here.] Their claims of producing small amounts of excess heat — energy — in their experiments were at first met with excitement, then skepticism and finally derision as other scientists were unable to reproduce the results [Houston Chronicle]. Most physicists eventually concluded that the extra energy was either a fluke or the product of an experimental error.

Mosier-Boss announced her team’s new findings at a meeting of the American Chemical Society yesterday, twenty years to the day since the earlier declaration. She has also published the work in the journal Naturwissenschaft.

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Seriously: Frank Sinatra Songs Restored Eyesight to Stroke Patients

By Eliza Strickland | March 24, 2009 8:48 am

headphonesWhile that headline may overstate the case slightly for comic effect, researchers say the gist of it is true: Stroke patients with impaired vision who listened to their favorite music showed vastly improved visual processing. Says lead researcher David Soto: “One of the patients chose Kenny Rogers, another Frank Sinatra and the third a country rock band. It’s not a particular kind of music that’s important, as long as the patient enjoys it” [Daily Mail].

Participants in Soto’s study had suffered lesions to their brains’ parietal cortex, a region central to visual and spatial processing. This left them with a condition called visual neglect, in which people lose half their spatial awareness. Victims will sometimes eat food from only one side of their plate, shave one side of their faces, or — as tested in the study — fail to perceive visual prompts on one side of a computer screen [Wired].  

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CATEGORIZED UNDER: Health & Medicine, Mind & Brain

In Terms of Enjoyment, Other People Know You Better Than You Do

By Rachel Cernansky | March 23, 2009 6:41 pm

thought.jpgTo figure out whether you’ll like the restaurant around the corner or that new guy in accounting or a vacation in Madrid, or just about anything else you’ve never personally experienced, try asking a stranger who has [Time]. That stranger is likely to predict, better than you can yourself, how much enjoyment you’ll get from that new experience (or the guy in accounting).

Previous research has shown that people tend to overestimate how disappointed or unhappy they will be after a perceived negative event, such as being denied a promotion, as well as how happy they will feel after positive events, like winning a prize. Building on that knowledge, psychology professor Daniel Gilbert conducted experiments in which he asked people to predict how much they’d enjoy a future event that they knew nothing about—except how much a total stranger had enjoyed it. Those people, it turns out, made extremely accurate predictions [WebMD].

In one experiment, women were asked to partake in “speed dating.” Subjects given reviews by women who had already “dated” participating men were able to gauge how well a date would go better than those who were only shown a picture and profile, and asked to come to their own conclusions.

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Bizarre Lobster-Sized Creature Was the Monster Predator of the Cambrian

By Eliza Strickland | March 23, 2009 5:35 pm

Cambrian predatorIn the Cambrian Period, one of the mightiest predators cruising the primeval oceans was a critter about the size of a lobster, researchers say, and it wouldn’t win any beauty contests: “The animal is very strange looking” [New Scientist], says Allison Daley, coauthor of a new study. But even though it measured only about one and a half feet in length, it had enough natural weaponry to dominate the marine food chain about 505 million years ago. “This mouth is kind of nasty. I always use the analogy of a pencil sharpener,” said [study coauthor] Jean-Bernard Caron…. “You put anything into this and you get the prey completely cut and broken into pieces” [Toronto Star].

It took researchers several years of combing through fossils to piece together the bizarre jigsaw puzzle that is Hurdia victoria – an ancestor of arthropods such as insects, spiders and crustaceans…. The first fossilised scraps of Hurdia were discovered in 1912. These were followed by further body parts that were so varied and unusual that they were incorrectly classified as either jellyfish, sea cucumbers or shrimp-like crustaceans [The Independent]. The breakthrough came when paleontologists rediscovered a nearly complete fossil that had been found in the Canadian Rockies almost one hundred years ago, and realized the earlier fragments were all parts of the same species.

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