الخميس، 8 مايو 2014

ScienceDaily: Top News

ScienceDaily: Top News


Astronomers create first realistic virtual universe

Posted: 07 May 2014 11:28 AM PDT

Move over, Matrix - astronomers have done you one better. They have created the first realistic virtual universe using a computer simulation called 'Illustris.' Illustris can recreate 13 billion years of cosmic evolution in a cube 350 million light-years on a side with unprecedented resolution.

As carbon dioxide levels rise, some crop nutrients will fall, researchers find

Posted: 07 May 2014 10:26 AM PDT

Researchers have some bad news for future farmers and eaters: As carbon dioxide levels rise this century, some grains and legumes will become significantly less nutritious than they are today.

Greenland melting due equally to global warming, natural variations

Posted: 07 May 2014 10:26 AM PDT

Up to half of the recent warming in Greenland and neighboring parts of the Canadian Arctic may be due to climate variations that originate in the tropical Pacific and are not connected with the overall warming of the planet. The other portion is likely due to global warming.

Living fossils in the Indo-Pacific Warm Pool: A refuge for thermophilic dinoflagellates during glaciations

Posted: 07 May 2014 10:23 AM PDT

Scientists have reported the unique discovery of the marine dinoflagellate Dapsilidinium pastielsii from Southeast Asia, notably the Indo-Pacific Warm Pool (IPWP). This unicellular species, with planktonic and benthic stages, was previously thought to have become extinct within the early Pleistocene. It evolved more than 50 million years ago and is the last survivor of a major early Cenozoic lineage.

Semi-synthetic organism: Scientists create first living organism that transmits added letters in DNA 'alphabet'

Posted: 07 May 2014 10:21 AM PDT

Scientists have engineered a bacterium whose genetic material includes an added pair of DNA "letters," or bases, not found in nature; the bacterium's cells can replicate the unnatural DNA bases more or less normally, as long as the molecular building blocks are supplied.

Yellowstone geyser eruptions influenced more by internal processes

Posted: 07 May 2014 08:48 AM PDT

The intervals between geyser eruptions depend on a delicate balance of underground factors, such as heat and water supply, and interactions with surrounding geysers. Some geysers are highly predictable, with intervals between eruptions varying only slightly. The predictability of these geysers offer earth scientists a unique opportunity to investigate what may influence their eruptive activity, and to apply that information to rare and unpredictable types of eruptions, such as those from volcanoes.

A hydrogel that knows when to go

Posted: 07 May 2014 08:47 AM PDT

Bioengineers have created a hydrogel that instantly turns from liquid to semisolid at close to body temperature -- and then degrades at precisely the right time. The gel shows potential as a bioscaffold to support the regrowth of bone and other three-dimensional tissues in a patient's body using the patient's own cells to seed the process.

A stellar explosion on the outer reaches of the Universe provides clues about black hole formation

Posted: 07 May 2014 08:47 AM PDT

On 24 October 2012 observatories across the world were alerted about a huge stellar explosion, the GRB121024A, which had been located just hours before in the Eridanus constellation. The data obtained on that explosion, which took place about 11,000 million years ago, have made it possible to reconstruct how a black hole is formed.

Mapping the spider genome: Surprising similarities to humans

Posted: 07 May 2014 07:50 AM PDT

For the first time ever, a group of researchers has sequenced the genome of the spider. This knowledge provides a much more qualified basis for studying features of the spider. It also shows that humans share certain genomic similarities with spiders. However, the sequencing has far greater significance for our future understanding of the spider's special properties. The researchers worked with two types of spiders, representing two of the three main groups in the spider family. One of these is a small velvet spider and the other is a tarantula.

Ancient crater points to massive meteorite strike

Posted: 07 May 2014 07:50 AM PDT

An eight-kilometer-wide crater suggests a meteorite strike devastated southern Alberta within the last 70 million years, experts theorize. Time and glaciers have buried and eroded much of the evidence, making it impossible at this point to say with full certainty the ring-like structure was caused by a meteorite impact, but that's what seismic and geological evidence strongly suggests.

Ability to isolate, grow breast tissue stem cells could speed cancer research

Posted: 07 May 2014 07:04 AM PDT

By carefully controlling the levels of two proteins, researchers have discovered how to keep mammary stem cells -- those that can form breast tissue -- alive and functioning in the lab. The new ability to propagate mammary stem cells is allowing them to study both breast development and the formation of breast cancers.

Melting an entire iceberg with a hot poker: Spotting phase changes triggered by impurities

Posted: 07 May 2014 07:04 AM PDT

"What a curious feeling," says Alice in Lewis Carroll's tale, as she shrinks to a fraction of her size, and everything around her suddenly looks totally unfamiliar. Scientists too have to get used to these curious feelings when they examine matter on tiny scales and at low temperatures: all the behavior we are used to seeing around us is turned on its head.

Sprites form at plasma irregularities in the lower ionosphere

Posted: 07 May 2014 07:04 AM PDT

Atmospheric sprites have been known for nearly a century, but their origins were a mystery. Now, a team of researchers has evidence that sprites form at plasma irregularities and may be useful in remote sensing of the lower ionosphere.

Newly found dinosaur is long-nosed cousin of Tyrannosaurus rex

Posted: 07 May 2014 07:04 AM PDT

Scientists have discovered a new species of long-snouted tyrannosaur, nicknamed Pinocchio rex, which stalked the Earth more than 66 million years ago. Researchers say the animal, which belonged to the same dinosaur family as Tyrannosaurus rex, was a fearsome carnivore that lived in Asia during the late Cretaceous period. The newly found ancient predator looked very different from most other tyrannosaurs.

Arctic study sheds light on tree-ring divergence problem: Changes in light intensity may impact density of tree rings

Posted: 07 May 2014 07:04 AM PDT

New research has found that changes in tree-ring density in the Arctic may be evidence of changes in light intensity during the trees' growth. The finding has direct implications for the tree-ring 'divergence problem,' in which the density of tree rings in recent decades has not kept pace with increases in temperature, as expected.

Psilocybin inhibits the processing of negative emotions in the brain

Posted: 07 May 2014 06:57 AM PDT

Emotions like fear, anger, sadness, and joy enable people to adjust to their environment and react flexibly to stress and strain and are vital for cognitive processes, physiological reactions, and social behavior. The processing of emotions is closely linked to structures  in the brain, i.e. to what is known as the limbic system. Within this system the amygdala  plays a central role – above all it processes negative emotions like anxiety and fear. If the activity of the amygdala becomes unbalanced, depression and anxiety disorders may develop.

Repeated preschool wheeze may set stage for long-term damage in lung function

Posted: 07 May 2014 06:53 AM PDT

Children who wheeze are at risk of developing damage that will affect their lung function by the age of 6 years, according to researchers. These appear to be persistent, even if asthma symptoms seem to disappear at least temporarily by school age in several cases. Children with recurrent symptoms that are severe enough to warrant a visit to the emergency department are particularly at risk of seeing their lung function affected.

Using DNA to build tool that may literally shine light on cancer

Posted: 07 May 2014 06:53 AM PDT

DNA has been used by researchers to develop a tool that detects and reacts to chemical changes caused by cancer cells and that may one day be used to deliver drugs to tumor cells. The researchers' nanosensor measures pH variations at the nanoscale -- how acidic or alkaline it is. Many biomolecules, such as enzymes and proteins, are strongly regulated by small pH changes. These changes affect in turn biological activities such as enzyme catalysis, protein assembly, membrane function and cell death. There is also a strong relation between cancer and pH.

Nearest bright 'hypervelocity star' found: Speeding at 1 million mph, it probes black hole and dark matter

Posted: 07 May 2014 06:30 AM PDT

Astronomers have discovered a "hypervelocity star" that is the closest, second-brightest and among the largest of 20 found so far. Speeding at more than 1 million mph, the star may provide clues about the supermassive black hole at the center of our Milky Way and the halo of mysterious "dark matter" surrounding the galaxy, astronomers say.

All teeth and claws? New study sheds light on dinosaur claw function

Posted: 06 May 2014 05:41 PM PDT

How claw form and function changed during the evolution from dinosaurs to birds is explored in a new study into the claws of a group of theropod dinosaurs known as therizinosaurs. Theropod dinosaurs, a group which includes such famous species as Tyrannosaurus rex and Velociraptor, are often regarded as carnivorous and predatory animals, using their sharp teeth and claws to capture and dispatch prey. However, a detailed look at the claws on their forelimbs revealed that the form and shape of theropod claws are highly variable and might also have been used for other tasks.

Anger motivates volunteers as much as sympathy

Posted: 06 May 2014 05:40 PM PDT

Anger can be just as effective at motivating people to volunteer as sympathy. "Although there are many reasons why individuals help, empathy is prominent. Empathy occurs when an individual has a similar response to a suffering person and this is usually sadness. Empathic sadness motivates a person to help in order to alleviate the other person's suffering and to alleviate one's own discomfort," one of the authors said.

Preparing for parenthood: Pregnant women show increased activity in right side of brain

Posted: 06 May 2014 05:40 PM PDT

Pregnant women show increased activity in the area of the brain related to emotional skills as they prepare to bond with their babies, according to a new study.

Shrinking helped dinosaurs and birds to keep evolving

Posted: 06 May 2014 04:07 PM PDT

Although most dinosaurs went extinct 65 million years ago, one dinosaur lineage survived and lives on today as a major evolutionary success story -- the birds. A study that has 'weighed' hundreds of dinosaurs suggests that shrinking their bodies may have helped the group that became birds to continue exploiting new ecological niches throughout their evolution, and become hugely successful today.

Revealing the healing of 'dino-sores': Examining broken bones in 150-million-year-old predatory dinosaur

Posted: 06 May 2014 04:06 PM PDT

Scientists have used state-of-the-art imaging techniques to examine the cracks, fractures and breaks in the bones of a 150-million-year-old predatory dinosaur. The research sheds new light, literally, on the healing process that took place when these magnificent animals were still alive.

Study validates air sampling techniques to fight bioterrorism

Posted: 06 May 2014 04:05 PM PDT

Air and surface sampling techniques currently used by the US government are effective in fighting bioterrorism and potentially saving lives, a researcher finds. In 2005 and 2009, the Pentagon Force Protection Agency (PFPA) in order to simulate a deliberate attack, staged the release of a harmless bacteria that is biological similar to Bacillus anthracis, the bacteria that causes the disease anthrax. They then evaluated the local response procedures to such an attack.

Surgeons 'light up' GI tract to safely remove gall bladder

Posted: 06 May 2014 04:05 PM PDT

A green fluorescent dye is helping surgeons perform robotic gall bladder surgery more safely. The surgeons in a recently published study used near-infrared light to make the indocyanine green dye light up, allowing them to better see the biliary tract. Injury to the bile duct is rare -- only 0.3 percent of the nearly 600,000 cholecystectomies performed in the U.S. annually -- but it can cause severe complications to patients. Surgeons are increasingly performing the gall bladder surgery robotically -- for better ergonomics, visualization and placement of surgical instruments.

Perceived age, weight discrimination worse for health than perceived racism, sexism

Posted: 06 May 2014 04:05 PM PDT

Perceived age and weight discrimination, more than perceived race and sex discrimination, are linked to worse health in older adults, according to new research. "Our previous research showed that perceived discrimination based on body weight was associated with risk of obesity. We wanted to see whether this association extended to other health indicators and types of discrimination," said lead author of the study.

Impulsivity is risk factor for food addiction

Posted: 06 May 2014 11:21 AM PDT

Have you ever said to yourself that you would only have a handful of potato chips from the bag then, minutes later, realized you ate the whole thing? A recent study shows that this type of impulsive behavior might not be easily controlled -- and could be a risk factor in the development of food addiction and eating disorders as a result of cellular activities in the part of the brain involved with reward.

How heart stem cells orchestrate regeneration

Posted: 06 May 2014 10:01 AM PDT

Investigators – whose previous research showed that cardiac stem cell therapy reduces scarring and regenerates healthy tissue after a heart attack in humans – have identified components of those stem cells responsible for the beneficial effects. In a series of laboratory and lab animal studies, researchers found that exosomes, tiny membrane-enclosed "bubbles" involved in cell-to-cell communication, convey messages that reduce cell death, promote growth of new heart muscle cells and encourage the development of healthy blood vessels.

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