الخميس، 24 نوفمبر 2011

ScienceDaily: Latest Science News

ScienceDaily: Latest Science News


They call it 'guppy love': Biologists solve an evolution mystery

Posted: 23 Nov 2011 04:04 PM PST

Guppies in the wild have evolved over at least half-a-million years -- long enough for the males' coloration to change dramatically. Yet an orange patch on the male has remained remarkably stable. Why has it remained the same hue of orange over such a long period of time? Because that is the color female guppies prefer.

Nanoparticle electrode for batteries could make grid-scale power storage feasible

Posted: 23 Nov 2011 12:19 PM PST

Researchers have used nanoparticles of a copper compound to develop a high-power battery electrode that is so inexpensive to make, so efficient and so durable that it could be used to build batteries big enough for economical large-scale energy storage on the electrical grid -- something researchers have sought for years.

Physicists set strongest limit on mass of dark matter

Posted: 23 Nov 2011 10:36 AM PST

Physicists have set the strongest limit for the mass of dark matter, the mysterious particles believed to make up nearly a quarter of the universe. The researchers report that dark matter must have a mass greater than 40 giga-electron volts. The distinction is important because it casts doubt on recent results from underground experiments that have reported detecting dark matter.

Key to aging? Key molecular switch for telomere extension by telomerase identified

Posted: 23 Nov 2011 10:35 AM PST

Researchers have described for the first time a key target of DNA damage checkpoint enzymes that must be chemically modified to enable stable maintenance of chromosome ends by telomerase, an enzyme thought to play a key role in cancer and aging.

Studying bat skulls, evolutionary biologists discover how species evolve

Posted: 23 Nov 2011 10:35 AM PST

A new study involving bat skulls, bite force measurements and scat samples collected by an international team of evolutionary biologists is helping to solve a nagging question of evolution: Why some groups of animals develop scores of different species over time while others evolve only a few.

Tiny levers, big moves in piezoelectric sensors

Posted: 23 Nov 2011 10:35 AM PST

Scientists have succeeded in integrating a new, highly efficient piezoelectric material into a silicon microelectromechanical system. This development could lead to significant advances in sensing, imaging, and energy harvesting.

New magnetic-field-sensitive alloy could find use in novel micromechanical devices

Posted: 23 Nov 2011 10:35 AM PST

A multi-institution team of researchers has combined modern materials research and an age-old metallurgy technique to produce an alloy that could be the basis for a new class of sensors and micromechanical devices controlled by magnetism.

Insect cyborgs may become first responders: Search and monitor hazardous places

Posted: 23 Nov 2011 10:35 AM PST

New developments may lead to insects monitoring hazardous situations before humans are sent in. The principal idea is to harvest the insect's biological energy from either its body heat or movements. The device converts the kinetic energy from wing movements of the insect into electricity, thus prolonging the battery life. The battery can be used to power small sensors implanted on the insect (such as a small camera, a microphone or a gas sensor) in order to gather vital information from hazardous environments.

Dreaming takes the sting out of painful memories

Posted: 23 Nov 2011 10:33 AM PST

They say time heals all wounds, and new research indicates that time spent in dream sleep can help. Researchers have found that during the dream phase of sleep, also known as REM sleep, our stress chemistry shuts down and the brain processes emotional experiences and takes the painful edge off difficult memories.

Earth's core deprived of oxygen

Posted: 23 Nov 2011 10:31 AM PST

Scientists know that the Earth's liquid outer core consists mainly of iron, but it is believed that small amounts of some other elements are also present. Oxygen is the most abundant element in the planet, so it is not unreasonable to expect oxygen might be one of the dominant "light elements" in the core. But new research proves otherwise. This has major implications for our understanding of the period when the Earth formed.

Monarch butterfly genome sequenced

Posted: 23 Nov 2011 10:31 AM PST

Each fall, millions of monarch butterflies from across the Eastern United States use a time-compensated sun compass to direct their navigation south, traveling up to 2,000 miles to an overwintering site in a specific grove of fir trees in central Mexico. Scientists have long been fascinated by the biological mechanisms that allow successive generations of these delicate creatures to travel such long distances to a small region roughly 300 square miles in size. To unlock the genetic and regulatory elements important for this remarkable journey neurobiologists have now sequenced and analyzed the monarch butterfly genome.

Caribbean fisheries highly vulnerable to climate change, need to adapt

Posted: 23 Nov 2011 10:30 AM PST

A new study predicts severe negative impacts, including loss and alteration of habitats, smaller and less-diverse fish stocks, and coral bleaching, and urges prompt action to help fisheries prepare.

First dogs came from East Asia, genetic study confirms

Posted: 23 Nov 2011 10:29 AM PST

Researchers say they have found further proof that the wolf ancestors of today's domesticated dogs can be traced to southern East Asia -- findings that run counter to theories placing the cradle of the canine line in the Middle East.

DNA system developed to identify and authenticate plant species

Posted: 23 Nov 2011 10:29 AM PST

Biologists have developed a method which can detect the use of illegal or counterfeit plants in medicine and could also be used to boost conservation by identifying and monitoring the exploitation of endangered plant species.

Discovery of a new muscle repair gene

Posted: 23 Nov 2011 10:28 AM PST

Scientists have presented new findings regarding the function of muscle stem cells. Researchers investigated several families with children suffering from a progressive muscle disease. Using a genetic analysis technique known as "next generation sequencing" the scientists identified a defective gene called MEGF10 responsible for the muscle weakness.

Psychopaths' brains show differences in structure and function

Posted: 22 Nov 2011 08:09 PM PST

Images of prisoners' brains show important differences between those who are diagnosed as psychopaths and those who aren't, according to a new study.

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