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Why Does the Brain Need So Much Power?

Wed, 07 May 2008 11:06:21 GMT

clipped by: wildcat

It is well established that the brain uses more energy than any other human organ, accounting for up to 20 percent of the body's total haul. Until now, most scientists believed that it used the bulk of that energy to fuel electrical impulses that neurons employ to communicate with one another. Turns out, though, that is only part of the story.

A new study in Proceedings of the National Academy of Sciences USA indicates that two thirds of the brain's energy budget is used to help neurons or nerve cells "fire'' or send signals. The remaining third, however, is used for what study co-author Wei Chen, a radiologist at the University of Minnesota Medical School, refers to as "housekeeping," or cell-health maintenance.

Their goal: to determine whether ATP production is linked to brain activity by measuring the energy expended during different levels of consciousness.

Sure enough, ATP levels appeared to vary with brain activity

Tags: brain, power, energy, atp, consciousness

Lots of Animals Learn, but Smarter Isn’t Better

Wed, 07 May 2008 09:59:18 GMT

clipped by: wildcat

Clip Source: www.nytimes.com

“Why are humans so smart?” is a question that fascinates scientists. Tadeusz Kawecki, an evolutionary biologist at the University of Fribourg, likes to turn around the question.

“If it’s so great to be smart,” Dr. Kawecki asks, “why have most animals remained dumb?”

Dr. Kawecki and like-minded scientists are trying to figure out why animals learn and why some have evolved to be better at learning than others. One reason for the difference, their research finds, is that being smart can be bad for an animal’s health.

Learning is remarkably widespread in the animal kingdom. Even the microscopic vinegar worm, Caenorhabditis elegans, can learn, despite having just 302 neurons. It feeds on bacteria. But if it eats a disease-causing strain, it can become sick.

The worms are not born with an innate aversion to the dangerous bacteria. They need time to learn to tell the difference and avoid becoming sick.

“People thought insects were little robots doing everything by instinct,”

Tags: smarts, learning, evolution

Not all fat created equal

Wed, 07 May 2008 09:25:24 GMT

clipped by: wildcat

Clip Source: physorg.com

It has long been known that type 2 diabetes is linked to obesity, particularly fat inside the belly. Now, researchers at the Joslin Diabetes Center have found that fat from other areas of the body can actually reduce insulin resistance and improve insulin sensitivity.

In a study published in the May issue of Cell Metabolism, a team lead by C. Ronald Kahn, M.D. found that subcutaneous fat -- fat found below the skin, usually in the hips and thighs -- is associated with reduced insulin levels and improved insulin sensitivity.

“This points to a new opportunity to find substances made by subcutaneous fat that may actually be good for glucose metabolism,’’ said Dr. Kahn, Head of the Joslin Research Section on Obesity and Hormone Action and the Mary K. Iacocca Professor of Medicine at Harvard Medical School. “If we can identify how subcutaneous fat does this, we will have a big clue as to where to look for these substances.”

Tags: fat, diabetes, glucose metabolism

Is quantum Internet search on the way?

Wed, 07 May 2008 09:19:52 GMT

clipped by: wildcat

Clip Source: physorg.com

In classical computing, random access memory (RAM) is needed to make things “work.” But it is subject to a certain level of energy loss. But what if you could create low-energy quantum access memory (QRAM) that would not only work in terms of quantum computing, but that could also be applied to classical computing?

Seth Lloyd, a researcher at MIT, believes that a new architecture for QRAM could be used to not only reduce the energy wasted by RAM, but also be used for completely anonymous Internet search. “My colleagues and I were interested in protocols for quantum Internet search,” he tells PhysOrg.com. “And we were also interested in what we could do with even a rudimentary quantum Internet. But first you have to develop this quantum RAM.”

Lloyd worked with Vittorio Giovannetti at the NEST-CNR-INFM in Pisa, Italy, and with Lorenzo Maccone at the University of Pavia, in Pavia, Italy, to put together a system that would work as QRAM

Tags: seth lloyd, quantum, ram

The Science of Cyclones

Wed, 07 May 2008 08:46:14 GMT

clipped by: wildcat

Clip Source: cosmiclog.msnbc.msn.com

The catastrophic cyclone that hit Myanmar hints at the shape of things to come in a warming world — but probably not for the reason you think. Chris Mooney, the author of "Storm World," argues that the tragedy says more about the sad state of infrastructure in the developing world than it does about the raw impact of climate change. However, shifts in climate will likely accentuate that global rich-vs.-poor split.

Mooney has been focusing on the intersection of science and politics for years - in his Weblog, aptly titled "The Intersection," as well as in his first book, "The Republican War on Science."

"Storm World: Hurricanes, Politics and the Battle Over Global Warming" traces more than a century of often-sharp disputes over climate science. Mooney, who grew up in New Orleans, was moved to delve deeply into the subject by Hurricane Katrina, one of the most politically charged storms in U.S. history.

Tags: cyclones, storms, infrastructure, rich, poor