Πέμπτη, 27 Μαρτίου 2014

ScienceDaily: Top Science News

ScienceDaily: Top Science News


Canal between ears helps alligators pinpoint sound

Posted: 26 Mar 2014 03:22 PM PDT

Alligators can accurately pinpoint the source of sounds. But it wasn't clear exactly how they did it because they lack external auditory structures. A new study shows that the alligator's ear is strongly directional because of large, air-filled channels connecting the two middle ears. This configuration is similar in birds, which have an interaural canal that increases directionality.

No correlation between medical marijuana legalization, crime increase: Legalization may reduce homicide, assault rates

Posted: 26 Mar 2014 03:20 PM PDT

A professor of criminology found that legalization of medical marijuana is not an indicator of increased crime. It actually may be related to reductions in certain types of violent crime. The study tracked crime rates across all 50 states between 1990 and 2006, when 11 states legalized marijuana for medical use: Alaska, California, Colorado, Hawaii, Maine, Montana, Nevada, Oregon, Rhode Island, Vermont and Washington. Since the time period the study covered, 20 states and Washington, D.C., have legalized marijuana for medical use.

Crows understand water displacement at the level of a small child: Show causal understanding of a 5- to 7-year-old child

Posted: 26 Mar 2014 03:20 PM PDT

New Caledonian crows may understand how to displace water to receive a reward, with the causal understanding level of a 5- to 7-year-old child. Understanding causal relationships between actions is a key feature of human cognition. However, the extent to which non-human animals are capable of understanding causal relationships is not well understood. Scientists used the Aesop's fable riddle -- in which subjects drop stones into water to raise the water level and obtain an out-of reach-reward -- to assess New Caledonian crows' causal understanding of water displacement.

Cuvier's beaked whales set new breath-hold diving records: Whales dive to nearly two miles depth, for over two hours

Posted: 26 Mar 2014 03:20 PM PDT

Scientists monitored Cuvier's beaked whales' record-breaking dives to depths of nearly two miles below the ocean surface and some dives lasted for over two hours.

Autism begins in pregnancy, according to study: Cortical layers disrupted during brain development in autism

Posted: 26 Mar 2014 03:19 PM PDT

Researchers have published a study that gives clear and direct new evidence that autism begins during pregnancy. The researchers analyzed 25 genes in post-mortem brain tissue of children with and without autism. These included genes that serve as biomarkers for brain cell types in different layers of the cortex, genes implicated in autism and several control genes.

The search for seeds of black holes

Posted: 26 Mar 2014 02:03 PM PDT

How do you grow a supermassive black hole that is a million to a billion times the mass of our sun? Astronomers do not know the answer, but a new study using data from NASA's Wide-field Infrared Survey Explorer, or WISE, has turned up what might be the cosmic seeds from which a black hole will sprout. The results are helping scientists piece together the evolution of supermassive black holes -- powerful objects that dominate the hearts of all galaxies.

Engineered bacteria produce biofuel alternative for high-energy rocket fuel

Posted: 26 Mar 2014 01:09 PM PDT

Researchers have engineered a bacterium to synthesize pinene, a hydrocarbon produced by trees that could potentially replace high-energy fuels, such as JP-10, in missiles and other aerospace applications. By inserting enzymes from trees into the bacterium scientists have boosted pinene production six-fold over earlier bioengineering efforts.

Major increase in West Antarctic glacial loss

Posted: 26 Mar 2014 12:37 PM PDT

Six massive glaciers in West Antarctica are moving faster than they did 40 years ago, causing more ice to discharge into the ocean and global sea level to rise, according to new research.

Solar system has a new most-distant member

Posted: 26 Mar 2014 12:37 PM PDT

The Solar System has a new most-distant member, bringing its outer frontier into focus. New work reports the discovery of a distant dwarf planet, called 2012 VP113, which was found beyond the known edge of the Solar System. This is likely one of thousands of distant objects that are thought to form the so-called inner Oort cloud. The work indicates the potential presence of an enormous planet, not yet seen, but possibly influencing the orbit of inner Oort cloud objects.

Ancient sea creatures filtered food like modern whales

Posted: 26 Mar 2014 11:22 AM PDT

Ancient, giant marine animals used bizarre facial appendages to filter food from the ocean, according to new fossils discovered in northern Greenland. The new study describes how the strange species, called Tamisiocaris, used these huge, specialized appendages to filter plankton, similar to the way modern blue whales feed today.

First ring system around asteroid: Chariklo found to have two rings

Posted: 26 Mar 2014 11:18 AM PDT

Astronomers have made the surprise discovery that the remote asteroid Chariklo is surrounded by two dense and narrow rings. This is the smallest object by far found to have rings and only the fifth body in the Solar System — after the much larger planets Jupiter, Saturn, Uranus and Neptune — to have this feature. The origin of these rings remains a mystery, but they may be the result of a collision that created a disc of debris.

First comprehensive atlas of human gene activity

Posted: 26 Mar 2014 11:16 AM PDT

Researchers have produced the first comprehensive, detailed map of the way genes work across the major cells and tissues of the human body. The findings describe the complex networks that govern gene activity, and the new information could play a crucial role in identifying the genes involved with disease.

Significant progress toward creating 'benchtop human' reported

Posted: 26 Mar 2014 10:53 AM PDT

Scientists are reporting significant progress toward creating "homo minutus" -- a benchtop human. Researchers have successfully developed and analyzed a liver human organ construct that responds to exposure to a toxic chemical much like a real liver.

Dark energy hides behind phantom fields

Posted: 26 Mar 2014 08:45 AM PDT

Quintessence and phantom fields, two hypotheses formulated using data from satellites are among the many theories that try to explain the nature of dark energy. Now researchers suggest that both possibilities are only a mirage in the observations and it is the quantum vacuum which could be behind this energy that moves our universe. Cosmologists believe that some three quarters of the universe are made up of a mysterious dark energy which would explain its accelerated expansion. The truth is that they do not know what it could be, therefore they put forward possible solutions.

Last drinks: Brain's mechanism knows when to stop

Posted: 26 Mar 2014 07:27 AM PDT

Our brains are hardwired to stop us drinking more water than is healthy, according to a new brain imaging study. The study found a 'stop mechanism' that determined brain signals telling the individual to stop drinking water when no longer thirsty, and the brain effects of drinking more water than required.

Altruistic side of aggressive greed

Posted: 26 Mar 2014 06:26 AM PDT

In many group-living species, high-rank individuals bully their group-mates to get what they want, but their contribution is key to success in conflict with other groups, according to a study that sheds new light on the evolutionary roots of cooperation and group conflict. In a series of mathematical models, researchers uncovered a mechanism for explaining how between-group conflict influences within-group cooperation and how genes for this behavior might be maintained in the population by natural selection.

Contaminated white dwarfs: Scientists solve riddle of celestial archaeology

Posted: 26 Mar 2014 06:22 AM PDT

A decades old space mystery has been solved by an international team of astronomers. The team put forward a new theory for how collapsed stars become polluted -- that points to the ominous fate that awaits planet Earth. Scientists investigated hot, young, white dwarfs -- the super-dense remains of Sun-like stars that ran out of fuel and collapsed to about the size of the Earth.

Fundamentals of facial recognition: Specialized brain mechanisms for recognizing faces?

Posted: 24 Mar 2014 12:40 PM PDT

Scientists showed that participants suffering from face blindness performed as well as the average person in training measuring their ability to learn a set of computer-generated objects called greebles. The findings undermine the leading alternative to the idea that prosopagnosia is the result of damage to brain mechanisms specifically devoted to processing faces, and thus indicate that people recognize faces using face-specific brain mechanisms.

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