Archive for July, 2008

Searching For Shut Eye: Possible ‘Sleep Gene’ Identified

While scientists and physicians know what happens if you don’t get six to eight hours of shut-eye a night, investigators have long been puzzled about what controls the actual need for sleep. Researchers at the University of Pennsylvania School of Medicine might have an answer, at least in fruit flies. In a recent study of fruit flies, they identified a gene that controls sleep.

“We spend — or should spend — a third of our lives sleeping,” says Amita Sehgal, PhD, Professor of Neuroscience and an Investigator with the Howard Hughes Medical Institute (HHMI). “The idea that so much time is spent in sleep is intriguing. Also, sleep deprivation has serious health consequences and impairs cognitive function.”

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Stellar Danger Zones, Planets Not Welcome

Astronomers have determined how far away from its hot stellar neighbors a star must be if a swirling disk of dust around it is to stand a chance of forming planets.

Using NASA’s Spitzer Space Telescope, scientists created the first maps of so-called planetary “danger-zones,” areas where winds and radiation from super-hot stars can strip younger, cooler stars like our Sun of their planet-forming materials.

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Quiet Explosion: Object Intermediate Between Normal Supernovae And Gamma-ray Bursts Found

A European-led team of astronomers are providing hints that a recent supernova may not be as normal as initially thought. Instead, the star that exploded is now understood to have collapsed into a black hole, producing a weak jet, typical of much more violent events, the so-called gamma-ray bursts.

The object, SN 2008D, is thus probably among the weakest explosions that produce very fast moving jets. This discovery represents a crucial milestone in the understanding of the most violent phenomena observed in the Universe.

These striking results, partly based on observations with ESO’s Very Large Telescope, will appear tomorrow in Science Express, the online version of Science.

Stars that were at birth more massive than about 8 times the mass of our Sun end their relatively short life in a cosmic, cataclysmic firework lighting up the Universe. The outcome is the formation of the densest objects that exist, neutron stars and black holes. When exploding, some of the most massive stars emit a short cry of agony, in the form of a burst of very energetic light, X- or gamma-rays.

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Cow Power Could Generate Electricity For Millions

Converting livestock manure into a domestic renewable fuel source could generate enough electricity to meet up to three per cent of North America’s entire consumption needs and lead to a significant reduction in greenhouse gas emissions (GHGs), according to new research.

The research has implications for all countries with livestock as it is the first attempt to outline a procedure for quantifying the national amount of renewable energy that herds of cattle and other livestock can generate and the concomitant GHG emission reductions.

Livestock manure, left to decompose naturally, emits two particularly potent GHGs — nitrous oxide and methane. According to the Intergovernmental Panel on Climate Change, nitrous oxide warms the atmosphere 310 times more than carbon dioxide, methane does so 21 times more.

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Largest Sample Of Very Distant Galaxies Ever Seen Provide New Insights Into Early Universe

New Hubble Space Telescope observations of six spectacular galaxy clusters acting as gravitational lenses have given significant insights into the early stages of the Universe. Scientists have found the largest sample of very distant galaxies seen to date: ten promising candidates thought to lie at a distance of 13 billion light-years (~redshift 7.5).

By using the gravitational magnification from six massive lensing galaxy clusters, the NASA/ESA Hubble Space Telescope has provided scientists with the largest sample of very distant galaxies seen to date. Some of the newly found magnified objects are dimmer than the faintest ones seen in the legendary Hubble Ultra Deep Field, which is usually considered the deepest image of the Universe.

By combining both visible and near-infrared observations from Hubble’s Advanced Camera for Surveys (ACS) and Near Infrared Camera and Multi-Object Spectrometer (NICMOS), scientists searched for galaxies that are only visible in near-infrared light. They uncovered 10 candidates believed to lie about 13 billion light-years away (a redshift of approximately 7.5), which means that the light gathered was emitted by the stars when the Universe was still very young — a mere 700 million years old.

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