Kamis, 24 April 2014

ScienceDaily: Top Science News

ScienceDaily: Top Science News


Drought may take toll on Congo rainforest, NASA satellites show

Posted: 23 Apr 2014 02:09 PM PDT

A new analysis of NASA satellite data shows Africa's Congo rainforest, the second-largest tropical rainforest in the world, has undergone a large-scale decline in greenness over the past decade. Scientists use the satellite-derived "greenness" of forest regions as one indicator of a forest's health. While this study looks specifically at the impact of a persistent drought in the Congo region since 2000, researchers say that a continued drying trend might alter the composition and structure of the Congo rainforest, affecting its biodiversity and carbon storage.

Rural microbes could boost city dwellers' health, study finds

Posted: 23 Apr 2014 02:09 PM PDT

The greater prevalence of asthma, allergies and other chronic inflammatory disorders among people of lower socioeconomic status might be due in part to their reduced exposure to the microbes that thrive in rural environments, according to a new scientific paper.

Male or female? First sex-determining genes appeared in mammals some 180 million years ago

Posted: 23 Apr 2014 12:10 PM PDT

The Y chromosome, which distinguishes males from females at the genetic level, appeared some 180 million years ago. It originated twice independently in all mammals. Scientists have managed to date these events that are crucial for both mammalian evolution and our lives, because the Y chromosome determines whether we are born as a boy or girl.

Superconducting qubit array points the way to quantum computers

Posted: 23 Apr 2014 12:10 PM PDT

A fully functional quantum computer is one of the holy grails of physics. Physicists have moved one step closer to making a quantum computer a reality by demonstrating a new level of reliability in a five-qubit array. Quantum computing is anything but simple. It relies on aspects of quantum mechanics such as superposition. This notion holds that any physical object, such as an atom or electron -- what quantum computers use to store information -- can exist in all of its theoretical states simultaneously. This could take parallel computing to new heights.

Hearing quality restored with bionic ear technology used for gene therapy: Re-growing auditory nerves

Posted: 23 Apr 2014 11:30 AM PDT

Researchers have for the first time used electrical pulses delivered from a cochlear implant to deliver gene therapy, thereby successfully regrowing auditory nerves. The research also heralds a possible new way of treating a range of neurological disorders, including Parkinson's disease, and psychiatric conditions such as depression through this novel way of delivering gene therapy.

Scientists identify source of mysterious sound in the Southern Ocean

Posted: 23 Apr 2014 10:26 AM PDT

Scientists have conclusive evidence that the source of a unique rhythmic sound, recorded for decades in the Southern Ocean and called the 'bio-duck,' is the Antarctic minke whale (Balaenoptera bonaerensis). First described and named by submarine personnel in the 1960s who thought it sounded like a duck, the bio-duck sound has been recorded at various locations in the Southern Ocean, but its source has remained a mystery, until now.

Odds of storm waters overflowing Manhattan seawall up 20-fold

Posted: 23 Apr 2014 10:26 AM PDT

Maximum water levels in New York harbor during major storms have risen by nearly two and a half feet since the mid-1800s, making the chances of water overtopping the Manhattan seawall now at least 20 times greater than they were 170 years ago, according to a new study.

Hundreds of genetic mutations found in healthy blood of a supercentenarian

Posted: 23 Apr 2014 10:26 AM PDT

Genetic mutations are commonly studied because of links to diseases such as cancer; however, little is known about mutations occurring in healthy individuals. Researchers have now detected over 400 mutations in healthy blood cells of a 115-year-old woman, suggesting that lesions at these sites are largely harmless over the course of a lifetime.

From liability to viability: Genes on the Y chromosome prove essential for male survival

Posted: 23 Apr 2014 10:24 AM PDT

The human Y chromosome has, over the course of millions of years of evolution, preserved a small set of genes that has ensured not only its own survival but also the survival of men. Moreover, the vast majority of these tenacious genes appear to have little if any role in sex determination or sperm production. Taken together, these remarkable findings suggest that because these Y-linked genes are active across the body, they may actually be contributing to differences in disease susceptibility and severity observed between men and women.

Surface area of the digestive tract much smaller than previously thought

Posted: 23 Apr 2014 08:15 AM PDT

The internal surface area of the gastro-intestinal tract has long been considered to be between 180 and 300 square meters. Scientists have used refined microscopic techniques that indicate a much smaller area. "Actually, the inner surface of the gastro-intestinal tract is only as large as a normal studio apartment," says one scientist.

Political ravens? Ravens notice the relationships among others, study shows

Posted: 23 Apr 2014 07:19 AM PDT

Cognitive biologists have revealed that ravens do understand and keep track of the rank relations between other ravens. Such an ability has been known only from primates. Like many social mammals, ravens form different types of social relationships -- they may be friends, kin, or partners and they also form strict dominance relations. From a cognitive perspective, understanding one's own relationships to others is a key ability in daily social life ("knowing who is nice or not"). Yet, also understanding the relationships group members have with each other sets the stage for "political" maneuvers ("knowing who might support whom").

Liquid spacetime: What if spacetime were a kind of fluid?

Posted: 23 Apr 2014 06:52 AM PDT

What if spacetime were a kind of fluid? This is the question tackled by theoretical physicists working on quantum gravity by creating models attempting to reconcile gravity and quantum mechanics. Some of these models predict that spacetime at the Planck scale is no longer continuous – as held by classical physics – but discrete in nature. Just like the solids or fluids we come into contact with every day, which can be seen as made up of atoms and molecules when observed at sufficient resolution. A structure of this kind generally implies, at very high energies, violations of Einstein's special relativity (a integral part of general relativity).

Brain circuits involved in emotion discovered by neuroscientists

Posted: 22 Apr 2014 05:23 PM PDT

A brain pathway that underlies the emotional behaviors critical for survival have been discovered by neuroscientists. The team has identified a chain of neural connections which links central survival circuits to the spinal cord, causing the body to freeze when experiencing fear. Understanding how these central neural pathways work is a fundamental step towards developing effective treatments for emotional disorders such as anxiety, panic attacks and phobias.

Cougars’ diverse diet helped them survive the mass extinction that wiped out the saber-tooth cat, American lion

Posted: 22 Apr 2014 05:20 PM PDT

Cougars may have survived the mass extinction that took place about 12,000 years ago because they were not particular about what they ate, unlike their more finicky cousins the saber-tooth cat and American lion who perished, according a new analysis of the microscopic wear marks on the teeth of fossil cougars, saber-tooth cats and American lions.

New electric fish genus, species discovered in Brazil's Rio Negro

Posted: 22 Apr 2014 09:12 AM PDT

Discovery of a new species of electric knife fish in the Amazon Basin in Brazil is leading to a new interpretation of classifications and interrelationships among closely related groups. As the diversity of electric fishes becomes more thoroughly documented, researchers will be able to explore possible causes of this group's adaptive radiation over evolutionary time.

Cow manure harbors diverse new antibiotic resistance genes

Posted: 22 Apr 2014 05:49 AM PDT

Manure from dairy cows, which is commonly used as a farm soil fertilizer, contains a surprising number of newly identified antibiotic resistance genes from the cows' gut bacteria. The findings hints that cow manure is a potential source of new types of antibiotic resistance genes that transfer to bacteria in the soils where food is grown. "Is this a route for movement of these genes from the barn to the table?" asks the senior study author.
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Rabu, 23 April 2014

ScienceDaily: Top Science News

ScienceDaily: Top Science News


Mantis shrimp stronger than airplanes: Composite material inspired by shrimp stronger than standard used in airplane frames

Posted: 22 Apr 2014 10:09 AM PDT

Inspired by the fist-like club of a mantis shrimp, researchers have developed a design structure for composite materials that is more impact resistant and tougher than the standard used in airplanes. The peacock mantis shrimp, or stomatopod, is a 4- to 6-inch-long rainbow-colored crustacean with a fist-like club that accelerates underwater faster than a 22-calibur bullet.

Fat metabolism in animals altered to prevent most common type of heart disease

Posted: 22 Apr 2014 09:10 AM PDT

Working with mice and rabbits, scientists have found a way to block abnormal cholesterol production, transport and breakdown, successfully preventing the development of atherosclerosis, the main cause of heart attacks and strokes and the number-one cause of death among humans. The condition develops when fat builds inside blood vessels over time and renders them stiff, narrowed and hardened, greatly reducing their ability to feed oxygen-rich blood to the heart muscle and the brain.

Male health linked to testosterone exposure in womb, study finds

Posted: 22 Apr 2014 08:34 AM PDT

Men's susceptibility to serious health conditions may be influenced by low exposure to testosterone in the womb, new research suggests. Understanding why some men have less of the hormone than others is important because testosterone is crucial for life-long health. Low levels of the hormone have been linked to obesity, diabetes and heart disease.

Brain size matters when it comes to animal self-control

Posted: 22 Apr 2014 08:34 AM PDT

Chimpanzees may throw tantrums like toddlers, but their total brain size suggests they have more self-control than, say, a gerbil or fox squirrel, according to a new study of 36 species of mammals and birds ranging from orangutans to zebra finches.

Life stressors trigger neurological disorders, researchers find

Posted: 22 Apr 2014 08:34 AM PDT

When mothers are exposed to trauma, illness, alcohol or other drug abuse, these stressors may activate a single molecular trigger in brain cells that can go awry and activate conditions such as schizophrenia, post-traumatic stress disorder and some forms of autism. Until now, it has been unclear how much these stressors have impacted the cells of a developing brain. Past studies have shown that when an expectant mother exposes herself to alcohol or drug abuse or she experiences some trauma or illness, her baby may later develop a psychiatric disorder later in life. But the new findings identify a molecular mechanism in the prenatal brain that may help explain how cells go awry when exposed to certain environmental conditions.

Speed-reading apps may impair reading comprehension by limiting ability to backtrack

Posted: 22 Apr 2014 08:34 AM PDT

To address the fact that many of us are on the go and pressed for time, app developers have devised speed-reading software that eliminates the time we supposedly waste by moving our eyes as we read. But don't throw away your books, papers, and e-readers just yet -- research suggests that the eye movements we make during reading actually play a critical role in our ability to understand what we've just read.

People pay more attention to upper half of field of vision, study shows

Posted: 22 Apr 2014 08:33 AM PDT

People pay more attention to the upper half of their field of vision, a study shows, a finding that could have ramifications for traffic signs to software interface design. "It doesn't mean people don't pay attention to the lower field of vision, but they were demonstrably better at paying attention to the upper field," the lead researcher says.

Researchers identify a new variant of Ebola virus in Guinea

Posted: 22 Apr 2014 08:33 AM PDT

In a new article, researchers have published their initial findings on the characteristics of the Ebola virus discovered in Guinea. Initial virological investigations enabled them to identify Zaire ebolavirus as the pathogen responsible for this epidemic.

International team sequences rainbow trout genome

Posted: 22 Apr 2014 08:33 AM PDT

An international team of researchers has mapped the genetic profile of the rainbow trout, a versatile salmonid whose relatively recent genetic history opens a window into how vertebrates evolve. The investigators focused on the rate at which genes have evolved since a rare genome doubling event occurred in the rainbow trout approximately 100 million years ago.

Cloaked DNA nanodevices survive pilot mission

Posted: 22 Apr 2014 07:00 AM PDT

By mimicking a viral strategy, scientists have created the first cloaked DNA nanodevice that survives the body's immune defenses. Their success opens the door to smart DNA nanorobots that use logic to spot cancerous tissue and manufacture drugs on the spot to cripple it, as well as artificial microscopic containers called protocells that detect pathogens in food or toxic chemicals in drinking water.

How are we different and what gave us the advantage over extinct types of humans like the Neanderthals?

Posted: 22 Apr 2014 05:47 AM PDT

In parallel with modern man (Homo sapiens), there were other, extinct types of humans with whom we lived side by side, such as Neanderthals and the recently discovered  Denisovans of Siberia. Yet only Homo sapiens survived. What was it in our genetic makeup that gave us the advantage?

Tarantulas' personality determines whether they copulate with males or cannibalize them

Posted: 22 Apr 2014 05:47 AM PDT

Sexual cannibalism in spiders – the attack and consumption of males by females before or after copulation – is very widespread. A new investigation analyses the reason behind such extreme behavior, at times even before the females have ensured the sperm's fertilization of their eggs.

Red stars and big bulges: How black holes shape galaxies

Posted: 22 Apr 2014 05:46 AM PDT

The universe we can see is made up of thousands of millions of galaxies, each containing anywhere from hundreds of thousands to hundreds of billions of stars. Large numbers of galaxies are elliptical in shape, red and mostly made up of old stars. Another (more familiar) type is the spiral, where arms wind out in a blue thin disk from a central red bulge. On average stars in spiral galaxies tend to be much younger than those in ellipticals. Now a group of astronomers has found a (relatively) simple relationship between the color of a galaxy and the size of its bulge: the more massive the bulge, the redder the galaxy.

Solved: Mysteries of a nearby planetary system

Posted: 22 Apr 2014 05:46 AM PDT

Mysteries of one of the most fascinating nearby planetary systems now have been solved. A new study presents the first viable model for the planetary system orbiting one the first stars discovered to have planets - the star named 55 Cancri. Numerous studies since 2002 had failed to determine a plausible model for the masses and orbits of two giant planets located closer to 55 Cancri than Mercury is to our Sun. Astronomers had struggled to understand how these massive planets orbiting so close to their star could avoid a catastrophe such as one planet being flung into the star, or the two planets colliding with each other.

Sleep behavior disorder linked to brain disease

Posted: 22 Apr 2014 05:45 AM PDT

A sleep disorder that causes people to act out their dreams is the best current predictor of brain diseases like Parkinson's and Alzheimer's, research suggests. In this disorder, the disturbance occurs during the rapid-eye-movement (REM) stage of sleep and causes people to act out their dreams, often resulting in injury to themselves and/or bed partner. In healthy brains, muscles are temporarily paralyzed during sleep to prevent this from happening.

'Upside-down planet' reveals new method for studying binary star systems

Posted: 21 Apr 2014 06:13 PM PDT

What looked at first like a sort of upside-down planet has instead revealed a new method for studying binary star systems. Astronomers confirmed the first "self-lensing" binary star system -- one in which the mass of the closer star can be measured by how powerfully it magnifies light from its more distant companion star. Though our sun stands alone, about 40 percent of similar stars are in binary (two-star) or multi-star systems, orbiting their companions in a gravitational dance.

Sleeping away infection: Researchers find link between sleep, immune function in fruitflies

Posted: 21 Apr 2014 06:13 PM PDT

When we get sick it feels natural to try to hasten our recovery by getting some extra shuteye. Researchers found that this response has a definite purpose, in fruitflies: enhancing immune system response and recovery to infection. "These studies provide new evidence of the direct and functional effects of sleep on immune response and of the underlying mechanisms at work. The take-home message from these papers is that when you get sick, you should sleep as much as you can -- we now have the data that supports this idea," researchers conclude.

Today's Antarctic region once as hot as California, Florida

Posted: 21 Apr 2014 01:43 PM PDT

Parts of ancient Antarctica were as warm as today's California coast, and polar regions of the southern Pacific Ocean registered 21st-century Florida heat, according to scientists using a new way to measure past temperatures.

First Eurasians left Africa up to 130,000 years ago

Posted: 21 Apr 2014 01:42 PM PDT

Scientists have shown that anatomically modern humans spread from Africa to Asia and Europe in several migratory movements. The first ancestors of today's non-African peoples probably took a southern route through the Arabian Peninsula as early as 130,000 years ago, the researchers found.

Krypton used to accurately date ancient Antarctic ice

Posted: 21 Apr 2014 12:19 PM PDT

Scientists have successfully identified the age of 120,000-year-old Antarctic ice using radiometric krypton dating -- a new technique that may allow them to locate and date ice that is more than a million years old. This will allow them to reconstruct the climate much farther back into Earth's history and potentially understand the mechanisms that have triggered the planet to shift into and out of ice ages.
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Selasa, 22 April 2014

ScienceDaily: Top Science News

ScienceDaily: Top Science News


Birthplace of the domesticated chili pepper identified in Mexico

Posted: 21 Apr 2014 06:39 AM PDT

Combining historical language and ecological information, as well as genetic and archaeological data, scientists have identified Central-east Mexico as the likely birthplace of the domesticated chili pepper.

More questions than answers as mystery of domestication deepens

Posted: 21 Apr 2014 06:37 AM PDT

New research on domestication raises more questions than it has answered. Scientists have outlined some of the key questions that have been raised about this pivotal event in human history.

Climate benefit of biofuels from corn residue: Researchers cast doubt

Posted: 20 Apr 2014 10:18 AM PDT

Biofuels made from corn stover -- stalks, leaves and cobs that remain after harvest -- appear to emit more carbon dioxide over their life cycle than federal standards allow, according to new research. The findings cast doubt on whether corn residue can be used to meet federal mandates to ramp up ethanol production and reduce greenhouse gas emissions.

Ancient DNA: Barnyard chickens living just a few hundred years ago looked far different from today's chickens

Posted: 18 Apr 2014 11:11 AM PDT

Ancient DNA adds a twist to the story of how barnyard chickens came to be. Analyzing DNA from the bones of chickens that lived 200-2,300 years ago in Europe, researchers report that some of the traits we associate with modern domestic chickens -- such as their yellowish skin -- only became widespread in the last 500 years, much more recently than previously thought.

From quark soup to atoms and stars

Posted: 18 Apr 2014 11:07 AM PDT

Scientists using the atom smasher at the U.S. Department of Energy's Brookhaven National Laboratory have observed a phase transition different than the smooth transition of the early universe from the hot "soup" of subatomic particles to the atoms, made up of neutrons, protons and electrons that are the building blocks of matter.
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Senin, 21 April 2014

ScienceDaily: Top Science News

ScienceDaily: Top Science News


Researchers rethink 'natural' habitat for wildlife

Posted: 18 Apr 2014 01:14 PM PDT

Protecting wildlife while feeding a world population predicted to reach nine billion by 2050 will require a holistic approach to conservation that considers human-altered landscapes such as farmland, according to researchers. A new study finds that a long-accepted theory used to estimate extinction rates, predict ecological risk and make conservation policy recommendations is overly pessimistic. The researchers point to an alternative framework that promises a more effective way of accounting for human-altered landscapes and assessing ecological risks.

Finding turns neuroanatomy on its head: Researchers present new view of myelin

Posted: 18 Apr 2014 01:14 PM PDT

Neuroscientists have made a discovery that turns 160 years of neuroanatomy on its head. Myelin, the electrical insulating material long known to be essential for the fast transmission of impulses along the axons of nerve cells, is not as ubiquitous as thought, according to a new work. "The fact that it is the most evolved neurons, the ones that have expanded dramatically in humans, suggests that what we're seeing might be the "future." As neuronal diversity increases and the brain needs to process more and more complex information, neurons change the way they use myelin to "achieve" more," says the main researcher.

Wireless power transfer achieved at 5-meter distance

Posted: 17 Apr 2014 09:45 AM PDT

A great improvement has been demonstrated in the distance that electric power can travel wirelessly. Researchers developed the 'Dipole Coil Resonant System' for an extended range of inductive power transfer, up to 5 meters between transmitter and receiver coils. "Our technology proved the possibility of a new remote power delivery mechanism that has never been tried at such a long distance. Although the long-range wireless power transfer is still in an early stage of commercialization and quite costly to implement, we believe that this is the right direction for electric power to be supplied in the future. Just like we see Wi-Fi zones everywhere today, we will eventually have many Wi-Power zones at such places as restaurants and streets that provide electric power wirelessly to electronic devices," they say.
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