Παρασκευή 24 Φεβρουαρίου 2012

ScienceDaily: Latest Science News

ScienceDaily: Latest Science News


Metal nanoparticles shine with customizable color

Posted: 23 Feb 2012 07:19 PM PST

Engineers have demonstrated a new kind of tunable color filter that uses optical nanoantennas to obtain precise control of color output.

Blood mystery solved: Two new blood types identified

Posted: 23 Feb 2012 03:38 PM PST

You probably know your blood type: A, B, AB or O. You may even know if you're Rhesus positive or negative. But how about the Langereis blood type? Or the Junior blood type? Positive or negative? Most people have never even heard of these. Yet this knowledge could be "a matter of life and death." While blood transfusion problems due to Langereis and Junior blood types are rare worldwide, several ethnic populations are at risk.

A rainbow for the palm of your hand

Posted: 23 Feb 2012 03:38 PM PST

Engineers have developed a one-step, low-cost method to fabricate a polymer that is rainbow-colored, reflecting many different wavelengths of light when viewed from a single perspective. The colors won't fade with time because they are produced by surface geometry, and not pigment -- the same principle that gives color to the wings of butterflies and feather of peacocks.

Replacing electricity with light: First physical 'metatronic' circuit created

Posted: 23 Feb 2012 03:38 PM PST

The technological world of the 21st century owes a tremendous amount to advances in electrical engineering, specifically, the ability to finely control the flow of electrical charges using increasingly small and complicated circuits. And while those electrical advances continue to race ahead, researchers are pushing circuitry forward in a different way, by replacing electricity with light.

More powerful electric cars: Mechanism behind capacitor's high-speed energy storage discovered

Posted: 23 Feb 2012 03:26 PM PST

Researchers have discovered the means by which a polymer known as PVDF enables capacitors to store and release large amounts of energy quickly. Their findings could lead to much more powerful and efficient electric cars.

MRIs on a nanoscale?

Posted: 23 Feb 2012 03:26 PM PST

Magnetic resonance imaging (MRI) on the nanoscale and the ever-elusive quantum computer are among the advancements edging closer toward the realm of possibility, and a new study may give both an extra nudge.

Eating citrus fruit may lower women's stroke risk

Posted: 23 Feb 2012 03:26 PM PST

Eating higher amounts of a compound in citrus fruits, especially oranges and grapefruit, may lower ischemic stroke risk. Women who ate high amounts of the compound had a 19 percent lower risk of ischemic stroke than women who consumed the least amount.

Neurotoxins in shark fins: A human health concern

Posted: 23 Feb 2012 03:25 PM PST

Sharks are among the most threatened of marine species worldwide due to unsustainable overfishing. They are primarily killed for their fins to fuel the growing demand for shark fin soup, which is an Asia delicacy. A new study has discovered high concentrations of BMAA in shark fins, a neurotoxin linked to neurodegenerative diseases in humans including Alzheimer's and Lou Gehrig Disease (ALS). The study suggests that consumption of shark fin soup and cartilage pills may pose a significant health risk for degenerative brain diseases.

Heart attacks: Naked mole-rats bear lifesaving clues

Posted: 23 Feb 2012 03:25 PM PST

A biologist thinks the subterranean lifestyle of the naked mole-rat may hold clues to keeping brain cells alive and functioning when oxygen is scarce, as during a heart attack. The key may lie in how brain cells regulate their intake of calcium, he says.

Climate change, increasing temperatures alter bird migration patterns

Posted: 23 Feb 2012 11:26 AM PST

Birds in eastern North America are picking up the pace along their yearly migratory paths. The reason, according to researchers, is rising temperatures due to climate change.

Breakthrough in designing cheaper, more efficient catalysts for fuel cells

Posted: 23 Feb 2012 11:26 AM PST

Chemists are redesigning catalysts in ways that could have a profound impact on the chemical industry as well as on the growing market for hydrogen fuel cell vehicles. Since all catalysts, such as platinum, speed chemical reactions only at edges and defects, the chemists synthesized these edge sites and set them on a molecular platform to create a catalyst that is all edge.

Key to growth differences between species

Posted: 23 Feb 2012 11:26 AM PST

The tiny, little-noticed jewel wasp may provide some answers as to how different species differ in size and shape. And that could lead to a better understanding of cell growth regulation, as well as the underlying causes of some diseases.

Earliest horses show past global warming affected body size of mammals

Posted: 23 Feb 2012 11:26 AM PST

As scientists continue developing climate change projection models, paleontologists studying an extreme short-term global warming event have discovered direct evidence about how mammals respond to rising temperatures. Researchers have now found a correlation between temperature and body size in mammals by following the evolution of the earliest horses about 56 million years ago: As temperatures increased, their body size decreased.

Evolution of earliest horses driven by climate change

Posted: 23 Feb 2012 11:26 AM PST

Some 56 million years ago, rising temps and concentrations of carbon dioxide caused mammals, including tiny Sifrhippus, to shrink. New research offers new evidence of why and how it happened and provides clues to what might happen to animals in the future from global warming.

Classic Maya Civilization collapse related to modest rainfall reductions, research suggests

Posted: 23 Feb 2012 11:24 AM PST

The disintegration of the Maya Civilization may have been related to relatively modest reductions in rainfall, according to new research. Rather modest rainfall reductions between times when the Classic Maya Civilization flourished and its collapse - between AD 800-950, seems to have caused the collapse. These reductions amount to only 25 to 40 per cent in annual rainfall, but they were large enough for evaporation to become dominant over rainfall, and open water availability was rapidly reduced, researchers say.

Illegal orangutan trader prosecuted

Posted: 23 Feb 2012 11:24 AM PST

Sumatra has made its first ever successful sentence of an illegal orangutan owner and trader in Medan, North Sumatra, Indonesia.

Aircraft of the future could capture and re-use some of their own power

Posted: 23 Feb 2012 10:33 AM PST

Tomorrow's aircraft could contribute to their power needs by harnessing energy from the wheel rotation of their landing gear to generate electricity. They could use this to power their taxiing to and from airport buildings, reducing the need to use their jet engines. This would save on aviation fuel, cut emissions and reduce noise pollution at airports.

Less is more: Study of tiny droplets could have big impact on industrial applications

Posted: 23 Feb 2012 10:32 AM PST

Researchers have discovered rules that govern how liquid spreads along flexible fibers and have found that when it comes to the size of liquid droplets, sometimes less is more.

Girls' verbal skills make them better at arithmetic, study finds

Posted: 23 Feb 2012 10:30 AM PST

While boys generally do better than girls in science and math, some studies have found that girls do better in arithmetic. A new study finds that the advantage comes from girls' superior verbal skills.

Chemical clues on formation of planetary systems: Earth 'siblings' can be different

Posted: 23 Feb 2012 10:29 AM PST

Astronomers have discovered that the chemical structure of Earth-like planets can be very different from the bulk composition of Earth. This may have a dramatic effect on the existence and formation of the biospheres and life on Earth-like planets.

Impulsive kids play more video games, and kids who play more video games may become more impulsive

Posted: 23 Feb 2012 07:41 AM PST

Impulsive children with attention problems tend to play more video games, while kids in general who spend lots of time video gaming may also develop impulsiveness and attention difficulties, according to new research.

Making droplets drop faster: New nanopatterned surfaces could improve the efficiency of powerplants and desalination systems

Posted: 23 Feb 2012 07:41 AM PST

New research offers important new insights into how water droplets form, and ways to pattern the collecting surfaces at the nanoscale to encourage droplets to form more rapidly. These insights could enable a new generation of significantly more efficient power plants and desalination plants, the researchers say.

U.S. urban forests losing ground

Posted: 23 Feb 2012 07:40 AM PST

National results indicate that tree cover in urban areas of the United States is declining at a rate of about 4 million trees per year.

Bisphenol A exposure linked to increased risk of future onset of heart disease

Posted: 23 Feb 2012 07:40 AM PST

Bisphenol A (BPA) is a controversial chemical widely used in the plastics industry. A new study followed people over a 10-year time period and shows that healthy people with higher urine concentrations of BPA were more likely to later develop heart disease.

How vitamin D inhibits inflammation

Posted: 23 Feb 2012 07:39 AM PST

Researchers have discovered specific molecular and signaling events by which vitamin D inhibits inflammation. Low levels of vitamin D failed to inhibit the inflammatory cascade, while levels considered adequate did inhibit inflammatory signaling.

Opinion: H5N1 flu is just as dangerous as feared, now requires action

Posted: 23 Feb 2012 07:39 AM PST

The debate about the potential severity of an outbreak of airborne H5N1 influenza in humans needs to move on from speculation and focus instead on how we can safely continue H5N1 research and share the results among researchers, according to experts.

A unique on-off switch for hormone production

Posted: 23 Feb 2012 07:39 AM PST

Scientists have revealed a new kind of on-off switch in the brain for regulating the production of a main biochemical signal from the brain that stimulates cortisol release in the body.

How cells brace themselves for starvation

Posted: 23 Feb 2012 07:39 AM PST

Cells that repress their "bad time" pumps when a nutrient is abundant were much more efficient at preparing for starvation and at recovering afterward than the cells that had been genetically engineered to avoid this repression.

Spectacularly bright object in Andromeda caused by 'normal' black hole

Posted: 23 Feb 2012 07:38 AM PST

A spectacularly bright object recently spotted in one of the Milky Way's neighbouring galaxies is the result of a "normal" stellar black hole, astronomers have found.

First ultraluminous source in Andromeda galaxy unmasked as 'normal' stellar mass black hole

Posted: 23 Feb 2012 07:36 AM PST

Detailed observations show that the first ultraluminous X-ray source detected in our neighboring Andromeda galaxy is due to a stellar mass black hole swallowing material at very high rates. The emission of the ultraluminous source probably originates from a system similar to X-ray binaries in our galaxy with matter accreting onto a black hole, which is at least 13 times more massive than our Sun. Unlike X-ray binaries in our own Milky Way, however, this source is much less obscured by interstellar gas and dust, allowing detailed investigations also at low X-ray energies.

OPERA experiment reports anomaly in flight time of neutrinos from CERN to Gran Sasso

Posted: 23 Feb 2012 05:12 AM PST

The OPERA collaboration has informed its funding agencies and host laboratories that it has identified two possible effects that could have an influence on its neutrino timing measurement. These both require further tests with a short pulsed beam. If confirmed, one would increase the size of the measured effect, the other would diminish it.

Surprising diversity at a synapse hints at complex diversity of neural circuitry

Posted: 22 Feb 2012 05:42 PM PST

A new study reveals a dazzling degree of biological diversity in an unexpected place – a single neural connection in the body wall of flies.

Memo to pediatricians: Screen all kids for vitamin D deficiency, test those at high risk

Posted: 22 Feb 2012 05:42 PM PST

As study after study shows the fundamental role vitamin D plays in disease and health, vitamin D deficiency — which often develops insidiously in childhood — should be on every parent's and pediatrician's radar, say physicians.

Newly approved drug for metastatic melanoma nearly doubles median survival

Posted: 22 Feb 2012 05:42 PM PST

A newly approved drug for patients with metastatic melanoma nearly doubles median survival times, a finding that will change the way this deadly form of skin cancer is treated.

Scientists discover likely new trigger for epidemic of metabolic syndrome

Posted: 22 Feb 2012 12:46 PM PST

Scientists have uncovered a key suspect in the destructive inflammation that underlies heart disease and diabetes.

Even in winter, life persists in Arctic Seas

Posted: 22 Feb 2012 12:46 PM PST

Despite brutal cold and lingering darkness, life in the frigid waters off Alaska does not grind to a halt in the winter as scientists previously suspected. Microscopic creatures at the base of the Arctic food chain are not dormant as expected, according to new findings.

Controlling protein function with nanotechnology

Posted: 22 Feb 2012 12:46 PM PST

A new study is providing important details on how proteins in our bodies interact with nanomaterials. Researchers have developed a new tool to determine the orientation of proteins on different nanostructures. The discovery is a key step in the effort to control the orientation, structure, and function of proteins in the body using nanomaterials.

Predator-prey relationships make possible the rich biodiversity of complex ecosystems

Posted: 22 Feb 2012 12:46 PM PST

As scientists warn that the Earth is on the brink of a period of mass extinctions, they are struggling to identify ecosystem responses to environmental change. But to truly understand these responses, more information is needed about how the Earth's staggering diversity of species originated.

Theory of the 'rotting' Y chromosome dealt a fatal blow

Posted: 22 Feb 2012 12:43 PM PST

If you were to discover that a fundamental component of human biology has survived virtually intact for the past 25 million years, you'd be quite confident in saying that it is here to stay. Such is the case for a team of scientists, whose latest research on the evolution of the human Y chromosome confirms that the Y -— despite arguments to the contrary —- has a long, healthy future ahead of it.

Disappearing and reappearing superconductivity surprises scientists

Posted: 22 Feb 2012 10:26 AM PST

Superconductivity is a rare physical state in which matter is able to conduct electricity -- maintain a flow of electrons -- without any resistance. This phenomenon can only be found in certain materials at low temperatures, or can be induced under chemical and high external pressure conditions. Research to create superconductors at higher temperatures has been ongoing for two decades with the promise of significant impact on electrical transmission. New work demonstrates unexpected superconductivity in a type of compounds called iron selenium chalcogenides.

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