Παρασκευή 21 Σεπτεμβρίου 2012

ScienceDaily: Top News

ScienceDaily: Top 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.

Sleep apnea in obese pregnancy women linked to poor maternal and neonatal outcomes

Posted: 20 Sep 2012 04:46 PM PDT

A new study reports that newborns of obese pregnant women suffering from obstructive sleep apnea are more likely to be admitted to the neonatal intensive care unit than those born to obese mothers without the sleep-disordered breathing. The sleep disorder was also associated with higher rates of preeclampsia in the severely overweight pregnant women.

Physicists reveal striking similarities in sporting performance

Posted: 20 Sep 2012 04:46 PM PDT

Finding the similarities between volleyball and snooker may seem quite tricky. However, a group of physicists have found that the spread of scores, otherwise known as distribution, across their ranking systems are almost identical.

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.

'Half-match' bone marrow transplants wipe out sickle cell disease in selected patients

Posted: 20 Sep 2012 01:46 PM PDT

In a preliminary clinical trial, investigators have shown that even partially-matched bone marrow transplants can eliminate sickle cell disease in some patients, ridding them of painful and debilitating symptoms, and the need for a lifetime of pain medications and blood transfusions. The researchers say the use of such marrow could potentially help make bone marrow transplants accessible to a majority of sickle cell patients who need them.

NASA's solar fleet peers into coronal cavities

Posted: 20 Sep 2012 01:46 PM PDT

The sun's atmosphere dances. Giant columns of solar material -- made of gas so hot that many of the electrons have been scorched off the atoms, turning it into a form of magnetized matter we call plasma -- leap off the sun's surface, jumping and twisting. Sometimes these prominences of solar material shoot off, escaping completely into space; other times they fall back down under their own weight. The prominences are sometimes also the inner structure of a larger formation, appearing from the side almost as the filament inside a large light bulb. The bright structure around and above that light bulb is called a streamer, and the inside "empty" area is called a coronal prominence cavity. Scientists have published new research on the temperatures of the sun's coronal cavities. By understanding aspects of these cavities -- that is the shape, density and temperature -- scientists can better understand the space weather that can disrupt technologies near Earth.

New uses for old tools could boost biodiesel output

Posted: 20 Sep 2012 01:46 PM PDT

Tried-and-true techniques could help optimize oilseed yield for biodiesel production, according to recent studies.

Global economic pressures trickle down to local landscape change, altering disease risk

Posted: 20 Sep 2012 01:46 PM PDT

The pressures of global trade may heighten disease incidence by dictating changes in land use. A boom in disease-carrying ticks and chiggers has followed the abandonment of rice cultivation in Taiwanese paddies, say ecologists, demonstrating the potential for global commodities pricing to drive the spread of infections.

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.

Taming physical forces that block cancer treatment

Posted: 20 Sep 2012 12:33 PM PDT

A research team has identified factors that contribute to solid stress within tumors, suggesting possible ways to alleviate it, and has developed a simple way to measure such pressures.

Environmental exposures unlikely to alter thyroid function of pregnant women, fetuses

Posted: 20 Sep 2012 12:31 PM PDT

Exposures to perchlorate (ClO4), a compound found at low levels in the environment, and thiocyanate (SCN), a compound found in cigarette smoke and some foods, is unlikely to alter thyroid function in pregnant women and fetuses, according to new data.

The original 'Twitter'? Tiny electronic tags monitor birds' social networks

Posted: 20 Sep 2012 12:31 PM PDT

A tiny, digital tag provides a first peek at the social lives of small animals. Using the tags to track New Caledonian crows revealed a surprising amount of interaction among the tool-using birds.

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.

Many proteins exist in a state of 'disorder' and yet are functional

Posted: 20 Sep 2012 11:11 AM PDT

For 100 years, the dogma has been that amino acid sequence determines protein folding and that the folded structure determines function. But researchers explain in a new study, a large class of proteins doesn't adhere to the structure-function paradigm. Called intrinsically disordered proteins, these proteins fail fold either in whole or in part and yet they are functional.

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.

Pesticides not yet proven guilty of causing honeybee declines, experts say

Posted: 20 Sep 2012 11:11 AM PDT

The impact of crop pesticides on honeybee colonies is unlikely to cause colony collapse, according to a new article. More research is now needed to predict the impact of widely-used agricultural insecticides, called neonicotinoids, on honeybee populations. Scientists have pointed out flaws in previous research that predicted that neonicotinoids could cause honeybee colony collapse. Neonicotinoids are among the most widely-used agricultural insecticides and honeybees ingest residues of the pesticides as they gather nectar and pollen from treated plants.

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.

Walking to the beat could help patients with Parkinson's disease

Posted: 20 Sep 2012 11:02 AM PDT

Walking to a beat could be useful for patients needing rehabilitation, according to a new study. The findings demonstrate that researchers should further investigate the potential of auditory, visual, and tactile cues in the rehabilitation of patients suffering from illnesses like Parkinson's disease -- a brain disorder leading to shaking (tremors) and difficulty walking.

Research uncovers path to defect-free thin films

Posted: 20 Sep 2012 11:02 AM PDT

Scientists have discovered a strain relaxation phenomenon in cobaltites that has eluded researchers for decades and may lead to advances in fuel cells, magnetic sensors and a host of energy-related materials.

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.

Nutrient in eggs and meat may influence gene expression from infancy to adulthood

Posted: 20 Sep 2012 11:01 AM PDT

Consuming greater amounts of choline -- a nutrient found in eggs and meat -- during pregnancy may lower an infant's vulnerability to stress-related illnesses, such as mental health disturbances, and chronic conditions, like hypertension, later in life.

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.

Playground peers can predict adult personalities

Posted: 20 Sep 2012 11:01 AM PDT

Even on the playground, our friends know us better than we know ourselves. New research has revealed that your childhood peers from grade school may be able to best predict your success as an adult.

Manipulating hormone receptors may help in the fight against obesity

Posted: 20 Sep 2012 10:56 AM PDT

In the body's ongoing effort to maintain a healthy weight, an arsenal of cellular proteins called androgen receptors is critical for blocking fat accumulation. Now researchers have discovered that naturally occurring steroids called glucocorticoids can thwart the receptors' activity, ultimately encouraging fat buildup.

Cause of diabetes may be linked to iron transport

Posted: 20 Sep 2012 10:56 AM PDT

Scientists have been trying to explain the causes of diabetes for many years. Researchers have now shown that the increased activity of one particular iron-transport protein destroys insulin-producing beta cells. In addition, the new research shows that mice without this iron transporter are protected against developing diabetes.

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.

Battles between steroid receptors to regulate fat accumulation

Posted: 20 Sep 2012 10:56 AM PDT

The androgen receptor in human cells inhibits fat accumulation, but its activity can be sabotaged by glucocorticoids, steroids that regulate fat deposition and are known drivers of obesity and insulin resistance.

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.

Genome-invading retroviruses have a nasty surprise for koalas: Serious pathological impact for centuries

Posted: 20 Sep 2012 10:53 AM PDT

By integrating themselves into the germ line of their host, retroviruses change the genetic code of their host. The only known case where this process can be currently observed is in Koalas. As scientists just found out, this process may take longer than expected, with the virus continuing to have a serious pathological impact on the host which may go on for centuries.

DNA analysis aids in classifying single-celled algae

Posted: 20 Sep 2012 09:05 AM PDT

For nearly 260 years -- since Carl Linnaeus developed his system of naming plants and animals -- researchers classified species based on visual attributes like color, shape and size. In the past few decades, researchers found that sequencing DNA can more accurately identify species. A group of single-celled algae -- Symbiodinum -- that live inside corals and are critical to their survival -- are only now being separated into species using DNA analysis, according to biologists.

In obesity, a micro-RNA causes metabolic problems

Posted: 20 Sep 2012 09:05 AM PDT

Scientists have identified a key molecular player in a chain of events in the body that can lead to fatty liver disease, Type II diabetes and other metabolic abnormalities associated with obesity. By blocking this molecule, the researchers were able to reverse some of the pathology it caused in obese mice.

Astrochemistry enters a bold new era with ALMA

Posted: 20 Sep 2012 09:05 AM PDT

New technology for both laboratory and telescope improves and speeds the process of identifying the "fingerprints" of chemicals in the cosmos, enabling previously-impracticable research.

Two bionic ears are better than the sum of their parts

Posted: 20 Sep 2012 09:04 AM PDT

Researchers have discovered that children who had lost their hearing at a young age and were later provided with bilateral cochlear implants exhibited hearing similar to that of their normal hearing peers. The study adds important information to the body of research on how brain function is impacted by both deafness and rehabilitation.

In heterosexuals, transmitted HIV strains often resemble original infecting virus

Posted: 20 Sep 2012 09:04 AM PDT

A new study has found that even though HIV diversifies widely within infected individuals over time, the virus strains that ultimately are passed on through heterosexual transmission often resemble the strain of virus that originally infected the transmitting partner. Learning the characteristics of these preferentially transmitted HIV strains may help advance HIV prevention efforts, particularly with regard to an HIV vaccine, according to the scientists who conducted the study.

'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.

Landing pads being designed for extraterrestrial missions

Posted: 20 Sep 2012 07:10 AM PDT

When the Mars Science Laboratory's Curiosity rover landed on Aug. 6, it was another step forward in the effort to eventually send humans to the Red Planet. Using the lessons of the Apollo era and robotic missions to Mars, NASA scientists and engineers are studying the challenges and hazards involved in any extraterrestrial landing.

Adolescent male chimps in large community strive to be alphas

Posted: 20 Sep 2012 06:53 AM PDT

An anthropologist reports the first observation of dominance relationships among adolescent male chimpanzees, which he attributes to the composition of their community.

Sudden cardiac death is associated with a thin placenta at birth, researchers find

Posted: 20 Sep 2012 05:27 AM PDT

Researchers studying the origins of sudden cardiac death have found that in both men and women a thin placenta at birth was associated with sudden cardiac death. A thin placenta may result in a reduced flow of nutrients from the mother to the fetus. The authors suggest that sudden cardiac death may be initiated by impaired development of the autonomic nervous system in the womb, as a result of fetal malnutrition.

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.

Antibiotic use aids MRSA spread in hospital and infection control measures do little to prevent it, says hospital study

Posted: 20 Sep 2012 05:25 AM PDT

The use of a commonly prescribed antibiotic is a major contributor to the spread of infection in hospitals by the 'superbug' MRSA, according to new research. The study also found that increasing measures to prevent infection – such as improved hygiene and hand washing – appeared to have only a small effect on reducing MRSA infection rates during the period studied.

Invisible plastic particles in seawater damaging to sea animals

Posted: 20 Sep 2012 05:25 AM PDT

The presence of 'plastic soup' in the oceans is regarded as a big problem. Tiny plastic particles enter the sea when plastic debris decomposes. Such particles are probably also released from cosmetics and from clothes in the wash, subsequently entering the sewage system and surface waters and eventually reaching the sea.

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.

Obese children have less sensitive taste-buds than those of normal weight

Posted: 19 Sep 2012 04:09 PM PDT

Obese kids have less sensitive taste-buds than kids of normal weight, new research indicates.

Invasive 'Rasberry Crazy Ant' in Texas now identified species

Posted: 19 Sep 2012 04:09 PM PDT

The Rasberry Crazy Ant is an invasive ant that was first noticed infesting areas around Houston, Texas ten years ago, but its species identity has remained undetermined until now.

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