Παρασκευή 18 Απριλίου 2014

ScienceDaily: Top Science News

ScienceDaily: Top Science News


More, bigger wildfires burning western US over last 30 years

Posted: 17 Apr 2014 12:12 PM PDT

Wildfires across the western United States have been getting bigger and more frequent over the last 30 years. The total area these fires burned increased at a rate of nearly 90,000 acres a year -- an area the size of Las Vegas, according to the study. Individually, the largest wildfires grew at a rate of 350 acres a year, the new research says.

First potentially habitable Earth-sized planet confirmed by Gemini and Keck observatories

Posted: 17 Apr 2014 11:19 AM PDT

The first Earth-sized exoplanet orbiting within the habitable zone of another star has been confirmed by observations with both the W. M. Keck Observatory and the Gemini Observatory. The initial discovery, made by NASA's Kepler Space Telescope, is one of a handful of smaller planets found by Kepler and verified using large ground-based telescopes. It also confirms that Earth-sized planets do exist in the habitable zone of other stars.

Thinnest membrane feasible has been produced

Posted: 17 Apr 2014 11:19 AM PDT

A new nano-membrane made out of the 'super material' graphene is extremely light and breathable. Not only can this open the door to a new generation of functional waterproof clothing, but also to ultra-rapid filtration. The new membrane just produced is as thin as is technologically possible.

Alternative identification methods for threatened species urged

Posted: 17 Apr 2014 11:19 AM PDT

With global climate change and rapidly disappearing habitat critical to the survival of endangered species, there is a sense of urgency to confirm the return of animals thought to be extinct, or to confirm the presence of newly discovered species. Researchers want to change how biologists think about collecting 'voucher' specimens for species identification, suggesting current specimen collection practices pose a risk to vulnerable animal populations nearing extinction.

Connecting sleep deficits among young fruit flies to disruption in mating later in life

Posted: 17 Apr 2014 11:19 AM PDT

Mom always said you need your sleep, and it turns out, she was right. According to a new study, the lack of sleep in young fruit flies profoundly diminishes their ability to do one thing they do really, really well -- make more flies. To address whether sleep loss in young flies affects development of courtship circuits, the team investigated a group of neurons implicated in courtship. One particular subset of those neurons was smaller in sleep-deprived animals than normal flies, suggesting a possible mechanism for how sleep deprivation can lead to altered courting behavior.

Boosting depression-causing mechanisms in brain increases resilience, surprisingly

Posted: 17 Apr 2014 11:18 AM PDT

New research uncovers a conceptually novel approach to treating depression. Instead of dampening neuron firing found with stress-induced depression, researchers demonstrated for the first time that further activating these neurons opens a new avenue to mimic and promote natural resilience.

There's something ancient in the icebox: Three-million-year-old landscape beneath Greenland Ice Sheet

Posted: 17 Apr 2014 11:18 AM PDT

Scientists were greatly surprised to discover an ancient tundra landscape preserved under the Greenland Ice Sheet, below two miles of ice. This finding provides strong evidence that the ice sheet has persisted much longer than previously known, enduring through many past periods of global warming.

Surprising material could play huge role in saving energy: Tin selenide is best at converting waste heat to electricity

Posted: 17 Apr 2014 09:45 AM PDT

One strategy for addressing the world's energy crisis is to stop wasting so much energy when producing and using it, such as in coal-fired power plants or transportation. Nearly two-thirds of energy input is lost as waste heat. Now scientists have discovered a surprising material that is the best in the world at converting waste heat to useful electricity. This outstanding property could be exploited in solid-state thermoelectric devices, with potentially enormous energy savings.

Fear of the cuckoo mafia: In fear of retaliation, birds accept and raise brood parasites' young

Posted: 17 Apr 2014 09:45 AM PDT

If a restaurant owner fails to pay the 'protection money' demanded of him by the mob, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to make restaurant owners pay up. Similarly, mafia-like behavior is observed in parasitic birds, which lay their eggs in other birds' nests. If the host birds throw the cuckoo's egg out, the brood parasites take their revenge by destroying the entire nest. Consequently, it is beneficial for hosts to be capable of learning and to cooperate. Previously seen only in field observations, scientists have now modeled this behavior mathematically to confirm it as an effective strategy.

A cross-section of the universe

Posted: 17 Apr 2014 09:44 AM PDT

An image of a galaxy cluster gives a remarkable cross-section of the universe, showing objects at different distances and stages in cosmic history. They range from cosmic near neighbors to objects seen in the early years of the universe. The 14-hour exposure shows objects around a billion times fainter than can be seen with the naked eye.

Biologists help solve fungal mysteries, inform studies on climate change

Posted: 17 Apr 2014 07:14 AM PDT

A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate change. Huge populations of fungi are churning away in the soil in pine forests, decomposing organic matter and releasing carbon into the atmosphere.

In sex-reversed cave insects, females have the penises

Posted: 17 Apr 2014 07:11 AM PDT

Little-known cave insects with rather novel sex lives have been discovered by researchers. The Brazilian insects, which represent four distinct but related species in the genus Neotrogla, are the first example of an animal with sex-reversed genitalia.

Study shows lasting effects of drought in rainy Eastern U.S.

Posted: 17 Apr 2014 06:08 AM PDT

This spring, more than 40 percent of the western U.S. is in a drought that the USDA deems "severe" or "exceptional." The same was true in 2013. In 2012, drought even spread to the humid east. But new research shows how short-lived but severe climatic events can trigger cascades of ecosystem change that last for centuries.

The story of animal domestication retold: Scientists now think wild animals interbred with domesticated ones until quite recently

Posted: 17 Apr 2014 06:08 AM PDT

A review of recent research on the domestication of large herbivores suggests that neither intentional breeding nor genetic isolation were as significant as traditionally thought. "Our findings show little control of breeding, particularly of domestic females, and indicate long-term gene flow, or interbreeding, between managed and wild animal populations," a co-author said.

Genetic study tackles mystery of slow plant domestications

Posted: 17 Apr 2014 06:08 AM PDT

Did domesticating a plant typically take a few hundred or many thousands of years? Genetic studies often indicate that domestication traits have a fairly simple genetic basis, which should facilitate their rapid evolution under selection. On the other hand, recent archeological studies of crop domestication have suggested a relatively slow spread and fixation of domestication traits. A new article tries to resolve the discrepancy.

New MRSA superbug emerges in Brazil

Posted: 17 Apr 2014 05:55 AM PDT

A new superbug that caused a bloodstream infection in a Brazilian patient has been identified by an international research team. The new superbug is part of a class of highly-resistant bacteria known as methicillin-resistant Staphylococcus aureus or MRSA, which is a major cause of hospital and community-associated infections. The superbug has also acquired high levels of resistance to vancomycin, the most common and least expensive antibiotic used to treat severe MRSA infections worldwide.

Earliest ancestor of land herbivores discovered: 300-million-year-old predator showed way to modern terrestrial ecosystem

Posted: 16 Apr 2014 02:22 PM PDT

New research demonstrates how carnivores transitioned into herbivores for the first time on land. Previously unknown, the 300-million-year old fossilized juvenile skeleton of Eocasea martini is less than 20 cm long. Found in Kansas, it consists of a partial skull, most of the vertebral column, the pelvis and a hind limb. By comparing the skeletal anatomy of related animals, scientists discovered that Eocasea martini belonged to the caseid branch of the group Synapsid. This group, which includes early terrestrial herbivores and large top predators, ultimately evolved into modern living mammals. Eocasea lived nearly 80 million years before the age of dinosaurs.

For cells, internal stress leads to unique shapes

Posted: 16 Apr 2014 01:26 PM PDT

A cell's unique shape results from an internal tug-of-war: the cell needs to maintain structural integrity while also dynamically responding to the pushes and pulls of mechanical stress, researchers have discovered. The researchers studied the supportive microtubule arrangement in the tissue of pavement cells from the first leaves -- or cotyledons -- of a young Arabidopsis thaliana plant.

Mars: Meteorites yield clues to Red Planet's early atmosphere

Posted: 16 Apr 2014 11:33 AM PDT

Geologists analyzed 40 meteorites that fell to Earth from Mars to understand the history of the Martian atmosphere. Their new article shows the atmospheres of Mars and Earth diverged in important ways early in the solar system's 4.6 billion year evolution.

Eavesdropping on brain cell chatter

Posted: 16 Apr 2014 11:33 AM PDT

Everything we do -- all of our movements, thoughts and feelings -- are the result of neurons talking with one another, and recent studies have suggested that some of the conversations might not be all that private. Brain cells known as astrocytes may be listening in on, or even participating in, some of those discussions. But a new mouse study suggests that astrocytes might only be tuning in part of the time -- specifically, when the neurons get really excited about something.

Crucial new information about how the ice ages came about

Posted: 16 Apr 2014 10:33 AM PDT

Scientists have discovered new relationships between deep-sea temperature and ice-volume changes to provide crucial new information about how the ice ages came about. The researchers found, for the first time, that the long-term trends in cooling and continental ice-volume cycles over the past 5.3 million years were not the same. In fact, for temperature the major step toward the ice ages that have characterized the past two to three million years was a cooling event at 2.7 million years ago, but for ice-volume the crucial step was the development of the first intense ice age at around 2.15 million years ago. Before these results, these were thought to have occurred together at about 2.5 million years ago.

At the origin of cell division: The features of living matter emerge from inanimate matter in simulation

Posted: 16 Apr 2014 06:04 AM PDT

Droplets of filamentous material enclosed in a lipid membrane: these are the models of a "simplified" cell used by physicists who simulated the spontaneous emergence of cell motility and division - that is, features of living material - in inanimate "objects".

People of color live in neighborhoods with more air pollution than whites, groundbreaking U.S. study shows

Posted: 15 Apr 2014 03:13 PM PDT

A first-of-its-kind study has found that on average in the U.S., people of color are exposed to 38 percent higher levels of nitrogen dioxide outdoor air pollution compared to white people. The health impacts from the difference in levels between whites and nonwhites found in the study are substantial. For example, researchers estimate that if nonwhites breathed the lower NO2 levels experienced by whites, it would prevent 7,000 deaths from heart disease alone among nonwhites each year.

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