Παρασκευή 21 Σεπτεμβρίου 2012

ScienceDaily: Top Science News

ScienceDaily: Top Science News


Dawn Sees Hydrated Minerals on Giant Asteroid

Posted: 20 Sep 2012 05:20 PM PDT

NASA's Dawn spacecraft has revealed that the giant asteroid Vesta has its own version of ring around the collar. Two new papers based on observations from the low-altitude mapping orbit of the Dawn mission show that volatile, or easily evaporated materials, have colored Vesta's surface in a broad swath around its equator. Pothole-like features mark some of the asteroid's surface where the volatiles, likely water, released from hydrated minerals boiled off. While Dawn did not find actual water ice at Vesta, there are signs of hydrated minerals delivered by meteorites and dust evident in the giant asteroid's chemistry and geology.

How bumblebees find efficient routes without a GPS: Bees use trial and error to select optimal route

Posted: 20 Sep 2012 04:46 PM PDT

Scientists have tracked bumblebees for the first time to see how they select the optimal route to collect nectar from multiple flowers and return to their nest.

Moving targets: Biologists gain new insight into migrating cells

Posted: 20 Sep 2012 12:33 PM PDT

At any given moment, millions of cells are on the move in the human body, typically on their way to provide a benefit to the structures around them. When the migration process goes wrong, however, the results can include tumor formation and metastatic cancer. Little has been known about how cell migration actually works, but now, researchers have gained new insight into this highly complex task.

Fear can be erased from the brain, research shows

Posted: 20 Sep 2012 11:11 AM PDT

Newly formed emotional memories can be erased from the human brain, according to new research. The findings may represent a breakthrough in research on memory and fear.

How the sub-Saharan cheetah got its stripes: Californian feral cats help unlock biological secret

Posted: 20 Sep 2012 11:11 AM PDT

Feral cats in Northern California have enabled researchers to unlock the biological secret behind a rare, striped cheetah found only in sub-Saharan Africa, according to researchers. The study is the first to identify a molecular basis of coat patterning in mammals.

Unusual symbiosis in marine microorganisms fertilizes ocean by fixing nitrogen

Posted: 20 Sep 2012 11:11 AM PDT

Scientists have discovered an unusual symbiosis between tiny single-celled algae and highly specialized bacteria. Their partnership plays an important role in marine ecosystems, fertilizing the oceans by taking nitrogen from the atmosphere and "fixing" it into a form that other organisms can use.

Khoe-San peoples diverged before 'out-of-Africa' migration of modern humans

Posted: 20 Sep 2012 11:11 AM PDT

The largest genomic study ever conducted among Khoe and San groups reveals that these groups from southern Africa are descendants of the earliest diversification event in the history of all humans -- some 100,000 years ago, well before the 'out-of-Africa' migration of modern humans.

Epigenetics: Mother's nutrition -- before pregnancy -- may alter function of her children's genes

Posted: 20 Sep 2012 11:01 AM PDT

A pregnant mom's diet affects her child's health. Now, new research in mice suggests that what mom ate before pregnancy is also important. The diets of female mice before pregnancy chemically altered their DNA, with these changes passed to their offspring. These alterations affected the pups' metabolism of many essential fatty acids. These results may profoundly impact future research for diabetes, obesity, cancer, and immune disorders.

Scientists uncover mechanism by which plants inherit epigenetic modifications

Posted: 20 Sep 2012 11:01 AM PDT

Scientists have discovered that epigenetic modifications can be inherited in pollen and that this process is guided by small RNA. By this mechanism, acquired traits can be inherited over many hundreds of generations. This discovery will influence the ways people think about cross-breeding to select for desirable traits in crops such as those that have important agricultural and economic implications.

Brain study reveals the roots of chocolate temptations

Posted: 20 Sep 2012 10:56 AM PDT

Researchers have new evidence in rats to explain how it is that chocolate candies can be so completely irresistible. The urge to overeat such deliciously sweet and fatty treats traces to an unexpected part of the brain and its production of a natural, opium-like chemical, according to a new report.

Study shows ancient relations between language families

Posted: 20 Sep 2012 10:53 AM PDT

How do language families evolve over many thousands of years? How stable over time are structural features of languages? Researchers introduced a new method using Bayesian phylogenetic approaches to analyse the evolution of structural features in more than 50 language families.

'Psychopaths' have an impaired sense of smell, study suggests

Posted: 20 Sep 2012 08:57 AM PDT

A new study suggests that a poor sense of smell may be a marker for psychopathic traits.

Humans were already recycling 13,000 years ago, burnt artifacts show

Posted: 20 Sep 2012 05:25 AM PDT

A new study reveals that humans from the Upper Palaeolithic Age recycled their stone artefacts to be put to other uses. The study is based on burnt artifacts found in Tarragona, Spain.

First giant salamander was a hot hunter

Posted: 20 Sep 2012 05:25 AM PDT

Modern giant salamanders live only in water – but their ancestors ventured out on land, say geoscientists at the University of Tübingen.

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