الثلاثاء، 5 مارس 2013

ScienceDaily: Top News

ScienceDaily: Top News


How the brain loses and regains consciousness: Brain patterns produced by general anesthesia revealed

Posted: 04 Mar 2013 06:15 PM PST

Researchers have identified distinctive brain patterns associated with different stages of general anesthesia.

Artificial leaf: Solar-to-fuel roadmap developed for crystalline silicon

Posted: 04 Mar 2013 06:15 PM PST

A new analysis points the way to optimizing efficiency of an integrated system for harvesting sunlight to make storable fuel.

'True grit' erodes assumptions about evolution

Posted: 04 Mar 2013 06:15 PM PST

New work in Argentina where scientists had previously thought Earth's first grasslands emerged 38 million years ago, shows the area at the time covered with tropical forests rich with palms, bamboos and gingers. Grit and volcanic ash in those forests could have caused the evolution of teeth in horse-like animals that scientists mistakenly thought were adaptations in response to emerging grasslands.

Extinction looms for forest elephants: 60 percent of Africa's forest elephants killed for their ivory over past decade

Posted: 04 Mar 2013 06:12 PM PST

Across their range in central Africa, a staggering 62 percent of all forest elephants have been killed for their ivory over the past decade, new research shows.

Daily-use HIV prevention approaches prove ineffective among women, study suggests

Posted: 04 Mar 2013 12:18 PM PST

Three antiretroviral-based strategies intended to prevent HIV infection among women did not prove effective in a major clinical trial in Africa. For reasons that are unclear, a majority of study participants -- particularly young, single women -- were unable to use their assigned approaches daily as directed, according to new findings.

Functional electrical stimulation cycling promotes recovery in chronic spinal cord injury

Posted: 04 Mar 2013 12:18 PM PST

A new study finds that long-term lower extremity functional electrical stimulation cycling, as part of a rehabilitation regimen, is associated with substantial improvements in individuals with chronic spinal cord injury. Improvements include neurological and functional gains, as well as enhanced physical health demonstrated by decreased fat, increased muscle mass and improved lipid profile.

Quantum realm: Forging new pathways to quantum devices

Posted: 04 Mar 2013 12:18 PM PST

Physicists are manipulating light on superconducting chips, and forging new pathways to building the quantum devices of the future -- including super-fast and powerful quantum computers.

Discovery of 'executioner' protein opens door to new options for stroke ALS, spinal cord injury

Posted: 04 Mar 2013 12:18 PM PST

Oxidative stress turns a protein that normally protects healthy cells into their executioner, according to a new study.

Brain adds cells in puberty to navigate adult world

Posted: 04 Mar 2013 12:18 PM PST

The brain adds new cells during puberty to help navigate the complex social world of adulthood, neuroscientists report.

Mom's placenta reflects her exposure to stress and impacts offsprings' brains

Posted: 04 Mar 2013 12:18 PM PST

The mammalian placenta is more than just a filter through which nutrition and oxygen are passed from a mother to her unborn child. According to a new study, if a mother is exposed to stress during pregnancy, her placenta translates that experience to her fetus by altering levels of a protein that affects the developing brains of male and female offspring differently.

Parkinson's disease brain rhythms detected: Finding suggests better way to monitor, treat disease with deep brain stimulation

Posted: 04 Mar 2013 12:18 PM PST

Scientists have discovered how to detect abnormal brain rhythms associated with Parkinson's by implanting electrodes within the brains of people with the disease.

Is baby still breathing? Is mom's obsession normal?

Posted: 04 Mar 2013 12:18 PM PST

A new mother may constantly worry and check to see if her baby is breathing. Or she may obsess about germs. A new study found postpartum moms have a much higher rate of obsessive-compulsive symptoms than the general population. This is the first large-scale study of obsessive-compulsive symptoms in new moms. The symptoms could result from hormonal changes or be adaptive, but may indicate a psychological disorder if they interfere with a mother's functioning.

Why your brain tires when exercising

Posted: 04 Mar 2013 12:18 PM PST

For the first time ever, a research team is able to explain why our brains feel tired when we exercise. By mapping the mechanism behind so-called central fatigue, the researchers are hoping, among other things, to learn more about how to identify doping use.

Global warming will open unexpected new shipping routes in Arctic, researchers find

Posted: 04 Mar 2013 12:18 PM PST

Shipping lanes through the Arctic Ocean won't put the Suez and Panama canals out of business anytime soon, but global warming will make these frigid routes much more accessible than ever imagined by melting an unprecedented amount of sea ice during the late summer, new research shows.

One law to rule them all: Sizes within a species appear to follow a universal distribution

Posted: 04 Mar 2013 12:16 PM PST

Biologists have discovered what might be a universal property of size distributions in living systems. If valid throughout the animal kingdom, it could have profound implications on how we understand population dynamics of large ecosystems.

Vortex loops could untie knotty physics problems

Posted: 04 Mar 2013 10:08 AM PST

Physicists have succeeding in creating a vortex knot -- a feat akin to tying a smoke ring into a knot. Linked and knotted vortex loops have existed in theory for more than a century, but creating them in the laboratory had previously eluded scientists.

Working at the extreme edge of cosmic ice

Posted: 04 Mar 2013 09:58 AM PST

Behind locked doors, in a lab built like a bomb shelter, Perry Gerakines makes something ordinary yet truly alien: ice. This isn't the ice of snowflakes or ice cubes. No, this ice needs such intense cold and low pressure to form that the right conditions rarely, if ever, occur naturally on Earth. And when Gerakines makes the ice, he must keep the layer so microscopically thin it is dwarfed by a grain of pollen. These ultrathin layers turn out to be perfect for recreating some of the key chemistry that takes place in space.

Cassini spies bright Venus from Saturn orbit

Posted: 04 Mar 2013 09:53 AM PST

A distant world gleaming in sunlight, Earth's twin planet, Venus, shines like a bright beacon in images taken by NASA's Cassini spacecraft in orbit around Saturn.

Exercise key to good sleep

Posted: 04 Mar 2013 09:35 AM PST

Exercise can affect your sleep. The results of the National Sleep Foundation's 2013 Sleep in America® poll show a compelling association between exercise and better sleep.

Unhealthy drinking widespread around the world

Posted: 04 Mar 2013 09:35 AM PST

A new study shows that alcohol is now the third leading cause of the global burden of disease and injury, despite the fact most adults worldwide abstain from drinking.

What predicts distress after episodes of sleep paralysis?

Posted: 04 Mar 2013 09:35 AM PST

Ever find yourself briefly paralyzed as you're falling asleep or just waking up? It's a phenomenon called sleep paralysis, and it's often accompanied by vivid sensory or perceptual experiences, including complex and disturbing hallucinations and intense fear. For some, sleep paralysis is a once-in-a-lifetime experience; for others, it can be a nightly phenomenon.

In Greenland and Antarctic tests, Yeti helps conquer some 'abominable' polar hazards

Posted: 04 Mar 2013 09:34 AM PST

A century after Western explorers first crossed the dangerous landscapes of the Arctic and Antarctic, researchers have successfully deployed a self-guided robot that uses ground-penetrating radar to map deadly crevasses hidden in ice-covered terrains.

Contraception in women over 40

Posted: 04 Mar 2013 09:34 AM PST

Despite declining fertility, women over age 40 still require effective contraception if they wish to avoid pregnancy. A review article outlines the risks and benefits of various contraceptive options for these women. The article is aimed at helping physicians find the best methods for their patients.

Scores that evaluate newborn intensive care units are inconsistent

Posted: 04 Mar 2013 09:32 AM PST

Future tools should build on success of current scores to improve care for vulnerable infants, according to new research.

Studies advance knowledge of HIV impact on hepatitis C infection and genes that may thwart hepatitis C infection

Posted: 04 Mar 2013 09:32 AM PST

Infectious disease experts have found that among people infected with the hepatitis C virus (HCV), co-infection with HIV, speeds damage and scarring of liver tissue by almost a decade.

Potential of large studies for building genetic risk prediction models

Posted: 04 Mar 2013 09:32 AM PST

Scientists have developed a new paradigm to assess hereditary risk prediction in common diseases, such as prostate cancer.

'OK' contact lenses work by flattening front of cornea, not the entire cornea

Posted: 04 Mar 2013 09:31 AM PST

A contact lens technique called overnight orthokeratology (OK) brings rapid improvement in vision for nearsighted patients. Now a new study shows that OK treatment works mainly by flattening the front of the cornea, reports a recent study.

Gene discovery reveals importance of eating your greens

Posted: 04 Mar 2013 07:56 AM PST

Eating your greens may be even more important that previously thought, with the discovery that an immune cell population essential for intestinal health could be controlled by leafy greens in your diet. The immune cells, named innate lymphoid cells, are found in the lining of the digestive system and protect the body from 'bad' bacteria in the intestine. They are also believed to play an important role in controlling food allergies, inflammatory diseases and obesity, and may even prevent the development of bowel cancers.

Researchers describe first 'functional HIV cure' in an infant

Posted: 04 Mar 2013 07:56 AM PST

A team of researchers describe the first case of a so-called "functional cure" in an HIV-infected infant. The finding, the investigators say, may help pave the way to eliminating HIV infection in children.

Fermat's Last Theorem and more can be proved more simply

Posted: 04 Mar 2013 07:56 AM PST

Mathematicians have shown Fermat's Last Theorem can be proved using only a small portion of Grothendieck's work. Specifically, the theorem can be justified using "finite order arithmetic."

Maternal diet important predictor of severity for infant respiratory syncytial virus (RSV)

Posted: 04 Mar 2013 07:56 AM PST

An important predictor of the severity of respiratory syncytial virus (RSV) in infants may be what their mothers ate during pregnancy, according to a new study.

Researchers identify queens, mysterious disease syndrome as key factors in bee colony deaths

Posted: 04 Mar 2013 07:56 AM PST

A new long-term study of honey bee health has found that a little-understood disease study authors are calling "idiopathic brood disease syndrome," which kills off bee larvae, is the largest risk factor for predicting the death of a bee colony.

First evidence that obesity gene is risk factor for melanoma

Posted: 04 Mar 2013 07:55 AM PST

The gene most strongly linked to obesity and over eating may also increase the risk of malignant melanoma -- the most deadly skin cancer, according to scientists.

Don't be fooled: Flowers mislead traditional taxonomy

Posted: 04 Mar 2013 07:55 AM PST

For hundreds of years, plant taxonomists have worked to understand how species are related. Until relatively recently, their only reliable source of information about these relationships was the plants' morphology--traits that could be observed, measured, counted, categorized, and described visually. And paramount among these morphological traits were aspects of flower shape and arrangement. However researchers have now found that floral morphologies may be less reliable than other traits in determining the relationships of papilionoid species and genera.

Grandmother's cigarette habit could be the cause of grandchild's asthma

Posted: 04 Mar 2013 07:55 AM PST

Studies finding that grandmother's smoking habit may cause her grandchild to have asthma suggest environmental factors experienced today can affect families' health for generations to come.

Beating heart cells in a lab dish: Creating new tissue instead of transplanting hearts

Posted: 04 Mar 2013 07:51 AM PST

Embryonic stem cells can develop into any kind of tissue. Adult stem cells can still turn into different kinds of cells, but their differentiation potential is significantly reduced. New substances have now been developed which allow the creation of fully functional heart cells.

Speech emerges in children on the autism spectrum with severe language delay at greater rate than previously thought

Posted: 04 Mar 2013 07:49 AM PST

Study could reveals key predictors of speech gains. New findings reveal that 70 percent of children with autism spectrum disorders (ASD) who have a history of severe language delay, achieved phrase or fluent speech by age eight.

ADHD takes a toll well into adulthood

Posted: 04 Mar 2013 07:47 AM PST

The first large, population-based study to follow children with attention-deficit hyperactivity disorder into adulthood shows that ADHD often doesn't go away and that children with ADHD are more likely to have other psychiatric disorders as adults. They also appear more likely to commit suicide and to be incarcerated as adults.

'Shelf life' of blood? Shorter than we think

Posted: 04 Mar 2013 07:47 AM PST

A small study adds to the growing body of evidence that red blood cells stored longer than three weeks begin to lose the capacity to deliver oxygen-rich cells where they may be most needed.

Losing weight sooner rather than later gives best chance of reversing heart damage from obesity, according to mouse study

Posted: 04 Mar 2013 07:47 AM PST

In a study of the impact of weight loss on reversing heart damage from obesity, researchers found that poor heart function in young obese mice can be reversed when the animals lose weight from a low-calorie diet. However, older mice, who had been obese longer, did not regain better heart function after they were on the same low-calorie diet.

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