الخميس، 15 ديسمبر 2011

ScienceDaily: Latest Science News

ScienceDaily: Latest Science News


Dinosaurs with killer claws yield new theory about evolution of flight

Posted: 14 Dec 2011 02:15 PM PST

New research has revealed how dinosaurs like Velociraptor and Deinonychus used their famous killer claws, leading to a new hypothesis on the evolution of flight in birds.

Alzheimer's drug candidate may be first to prevent disease progression, mouse study suggests

Posted: 14 Dec 2011 01:21 PM PST

A new drug candidate may be the first capable of halting the devastating mental decline of Alzheimer's disease, based on the findings of a new study.

Brain's failure to appreciate others may permit human atrocities

Posted: 14 Dec 2011 01:21 PM PST

It may be that a person can become callous enough to commit human atrocities because of a failure in the part of the brain that's critical for social interaction. A new study suggests this function may disengage when people encounter others they consider disgusting.

Magnetic stimulation of brain may help some stroke patients recover

Posted: 14 Dec 2011 01:20 PM PST

Imagine waking up and being unable to see or recognize anything on the left side of your body. This condition, called hemispatial neglect, is common after a stroke that occurs on the right side of the brain. The current treatment of attention and concentration training using computer and pencil-and-paper tasks is inadequate.

Early research on cellphone conversations likely overestimated crash risk, study suggests

Posted: 14 Dec 2011 12:11 PM PST

A new study suggests that two influential early studies of cellphone use and crash risk may have overestimated the relative risk of conversation on cellphones while driving.

'Green routing' can cut car emissions without significantly slowing travel time

Posted: 14 Dec 2011 11:47 AM PST

The path of least emissions may not always be the fastest way to drive somewhere. But according to new research, it's possible for drivers to cut their tailpipe emissions without significantly slowing travel time.

Artichokes grow big in Texas

Posted: 14 Dec 2011 11:47 AM PST

Marketable yield, yield components, quality, and phenolic compounds of artichoke heads were investigated in response to three irrigation regimes and four nitrogen rates under subsurface drip irrigation. Results showed that irrigation was more effective than N management for optimizing artichoke yield. Time of harvest had the largest effect on artichoke nutritional quality, followed by deficit irrigation. The study will help introduce artichoke cultural practices into commercial production in water-limited regions of the southern United States.

Growstones ideal alternative to perlite, parboiled rice hulls

Posted: 14 Dec 2011 11:47 AM PST

A study determined the properties of an aggregate produced from ground waste glass and compared the component with perlite and parboiled rice hulls. Experiments determined how Growstones affected root substrate properties and evaluated plant growth in different substrates. Results showed that Growstones had an air-filled pore space higher than that of both peat and perlite, and that Growstones added to peat at a concentration of at least 15 percent increased AFP of the peat-based substrate.

Brain-heart link may explain sudden death in Rett syndrome

Posted: 14 Dec 2011 11:47 AM PST

Poets might scoff at the notion that heart and brain are closely related, but scientists say a genetic defect that affects the brain can stop a heart. In a new study, researchers found that heart problems that occur in nearly 20 percent of children with Rett syndrome, a neurological disorder, originate because the Rett gene is lost in nerve cells -- not in heart muscle cells.

How granular materials become solid: Discovery may be boon to engineers, manufacturers

Posted: 14 Dec 2011 10:58 AM PST

What is it is that makes granular materials change from a flowing loose state to a "jammed," or solid, state? Researchers can now explain how granular materials are transformed when force is applied at a particular angle, a process known as shearing.

New eco-friendly foliar spray provides natural anti-freeze

Posted: 14 Dec 2011 10:58 AM PST

A new, biodegradable foliar/floral spray that increases plant resistance to both cold damage and cold mortality has been introduced to the commercial market. The spray improved cold tolerance by approximately 2°F to 9°F, depending on the variety of plant and the duration/ intensity of frost or freeze. Use of the non-toxic spray could add the equivalent of approximately 0.25 to almost 1.0 USDA Plant Hardiness Zone to the cold hardiness rating of plants.

Landscape architecture survey: Is plant knowledge passé?

Posted: 14 Dec 2011 10:58 AM PST

A study evaluated attitudes and perceptions of practicing landscape architects in the southeastern United States with regards to the importance of horticultural knowledge. While seasoned practitioners in the residential design market said they had a favorable opinion of their own plant knowledge, they felt that recent graduates in landscape architecture have insufficient knowledge of plants. The authors say the study shows a continued need for both formal and informal extended education classes for the profession.

How exposure to irregular light affects plant circadian rhythms

Posted: 14 Dec 2011 10:58 AM PST

A study of chrysanthemum investigated plants' circadian responses to interruptions in light cycles. Plants were exposed to irregular supplemental light breaks during the night; results showed a correlation between circadian-regulated processes and plant growth. Leaves and stems grew faster in plants grown in short days with irregular light breaks during the night compared with plants grown in a climate with a consecutive long light period. The findings could contribute to energy savings in production greenhouses.

New findings about the 'supernova of a generation'

Posted: 14 Dec 2011 10:57 AM PST

Astrophysicists have discovered that a supernova that exploded in August -- dubbed the supernova of a generation -- was a "white dwarf" star, and that its companion star could not have been a "red giant," as previously suspected.

'Supernova of a generation' shows its stuff: Astronomers determine how brightest and closest stellar explosion in 25 years happened

Posted: 14 Dec 2011 10:57 AM PST

It was the brightest and closest stellar explosion seen from Earth in 25 years, dazzling professional and backyard astronomers alike. Now, thanks to this rare discovery -- which some have called the "supernova of a generation" -- astronomers have the most detailed picture yet of how this kind of explosion happens.

Stress causes clogs in coffee and coal

Posted: 14 Dec 2011 10:57 AM PST

Scientists still aren't sure what causes clogs in flowing macroscopic particles, like corn, coffee beans and coal chunks. But new experiments suggest that when particles undergo a force called shear strain, they jam sooner than expected.

Solving a supernova mystery

Posted: 14 Dec 2011 10:57 AM PST

A team of scientists has observed the early stages of a Type Ia supernova that is only 21 million light years away from Earth -- the closest of its kind discovered in 25 years. The team's detection of a supernova less than half a day after it exploded will refine and challenge our understanding of these stellar phenomena.

Disaster looms for gas cloud falling into Milky Way's central black hole

Posted: 14 Dec 2011 10:57 AM PST

Astronomers have observed a cloud of gas several times the mass of Earth approaching the 4.3 million solar-mass black hole at the center of the Milky Way, and calculate that it will not survive the encounter. Astronomers calculate that by 2013, the cloud will be shredded and heated, emitting X-rays. The violent event provides a unique opportunity to record a black hole disruption until now only theorized.

Supernova caught in the act

Posted: 14 Dec 2011 10:57 AM PST

The earliest detection ever of a Type Ia supernova has led to unparalleled observations of the initial stages of the supernova and characterization of the stars that formed it. Early detection and close proximity of the stars set the stage for unprecedented observation of the initial stages of a Type Ia supernova.

Closest Type Ia supernova in decades solves a cosmic mystery

Posted: 14 Dec 2011 10:57 AM PST

Even as the "supernova of a generation" came into view in backyards across the northern hemisphere last August, physicists and astronomers who had caught its earliest moments were developing a surprising and much clearer picture of what happens during a titanic Type Ia explosion. Now they have announced the closest, most detailed look ever at one of the universe's brightest "standard candles," the celestial mileposts that led to the discovery of dark energy.

A black hole's dinner is fast approaching

Posted: 14 Dec 2011 10:56 AM PST

Astronomers using ESO's Very Large Telescope have discovered a gas cloud with several times the mass of Earth accelerating fast towards the black hole at the center of the Milky Way. This is the first time ever that the approach of such a doomed cloud to a supermassive black hole has been observed.

Heart drug may be effective for managing certain cancers, study suggests

Posted: 14 Dec 2011 10:00 AM PST

Researchers have identified a new mechanism that could potentially explain why the body's immune system sometimes fails to eliminate cancer. The new findings shed light on the possible cause of immune resistance in cancer cells, and indicate that nitroglycerin, a relatively safe and low-cost drug used for more than a century to treat angina, may be effective for managing certain cancers.

Cigarette and alcohol use at historic low among teens

Posted: 14 Dec 2011 09:59 AM PST

Cigarette and alcohol use by eighth, 10th and 12th-graders are at their lowest point since the Monitoring the Future survey began polling teenagers in 1975, according to this year's survey results. However, this positive news is tempered by a slowing rate of decline in teen smoking as well as continued high rates of abuse of other tobacco products (e.g., hookahs, small cigars, smokeless tobacco), marijuana and prescription drugs.

Ability to love takes root in earliest infancy

Posted: 14 Dec 2011 09:59 AM PST

The ability to trust, love, and resolve conflict with loved ones starts in childhood -- way earlier than you may think. New research suggests that your relationship with your mother during the first 12 to 18 months of life predict your behavior in romantic relationships 20 years later.

New method for enhancing thermal conductivity could cool computer chips, lasers and other devices

Posted: 14 Dec 2011 09:59 AM PST

Engineers have discovered a surprising new way to increase a material's thermal conductivity that provides a new tool for managing thermal effects in computers, lasers and a number of other powered devices.

Ramping up wind energy research

Posted: 14 Dec 2011 09:58 AM PST

As the percentage of wind energy contributing to the power grid continues to increase, the variable nature of wind can make it difficult to keep the generation and the load balanced. But recent work may help this balance through a project that alerts control room operators of wind conditions and energy forecasts so they can make well-informed scheduling decisions. This is especially important during extreme events, such as ramps, when there is a sharp increase or decrease in the wind speed over a short period of time, which leads to a large rise or fall in the amount of power generated.

Human proteins that may fuel HIV/AIDS transmission identified

Posted: 14 Dec 2011 09:58 AM PST

Scientists have discovered new protein fragments in semen that enhance the ability of HIV, the virus that causes AIDS, to infect new cells -- a discovery that one day could help curb the global spread of this deadly pathogen.

Cascade lasers become three times more powerful

Posted: 14 Dec 2011 09:58 AM PST

Cascade lasers are the newest generation of semiconductor lasers, currently only on the brink of commercialization. Scientists have developed technology to produce mid-infrared GaAs based cascade lasers with a three times stronger pulse than previous lasers. The new devices pave the way for promising industrial and medical applications.

Sharpening the lines: Advance could lead to smaller features in the quest for more compact, faster microchips

Posted: 14 Dec 2011 07:56 AM PST

The microchip revolution has seen a steady shrinking of features on silicon chips, packing in more transistors and wires to boost chips' speed and data capacity. But in recent years, the technologies behind these chips have begun to bump up against fundamental limits, such as the wavelengths of light used for critical steps in chip manufacturing. Now, a new technique offers a way to break through one of these limits, possibly enabling further leaps in the computational power packed into a tiny sliver of silicon.

Glow of recognition: New detectors could provide easy visual identification of toxins or pathogens

Posted: 14 Dec 2011 07:29 AM PST

Researchers have developed a new way of revealing the presence of specific chemicals -- whether toxins, disease markers, pathogens or explosives. The system visually signals the presence of a target chemical by emitting a fluorescent glow.

Society may get stuck with the bill for expensive higher education

Posted: 14 Dec 2011 07:29 AM PST

The rising cost of a college education and limited access to financial aid may create a less productive workforce and steeper wealth inequity, according to a study by North American economists.

Mercury releases into the atmosphere from ancient to modern times

Posted: 14 Dec 2011 07:28 AM PST

In pursuit of riches and energy over the last 5,000 years, humans have released into the environment 385,000 tons of mercury, the source of numerous health concerns, according to a new study that challenges the idea that releases of the metal are on the decline.

Cotton fabric cleans itself when exposed to ordinary sunlight

Posted: 14 Dec 2011 07:28 AM PST

Imagine jeans, sweats or socks that clean and deodorize themselves when hung on a clothesline in the sun or draped on a balcony railing. Scientists are reporting development of a new cotton fabric that does clean itself of stains and bacteria when exposed to ordinary sunlight.

Pythons and people take turns as predators and prey

Posted: 14 Dec 2011 07:28 AM PST

People and giant snakes not only target each other for food -- they also compete for the same prey, according to a new study.

Twisting molecules by brute force: A top-down approach

Posted: 14 Dec 2011 07:28 AM PST

Researchers have found they can use a macroscopic brute force to impose and induce a twist in an otherwise non-chiral molecule.

New test could help track down and prosecute terrorists who use nerve gas and other agents

Posted: 14 Dec 2011 07:28 AM PST

Scientists are reporting development of a first-of-its-kind technology that could help law enforcement officials trace the residues from terrorist attacks involving nerve gas and other chemical agents back to the companies or other sources where the perpetrators obtained ingredients for the agent. The technique could eventually help track down perpetrators of chemical attacks.

Follow your nose: Compared to Neanderthals, modern humans have a better sense of smell

Posted: 14 Dec 2011 07:18 AM PST

High-tech medical imaging techniques were recently used to access internal structures of fossil human skulls. Researchers used sophisticated 3-D methods to quantify the shape of the basal brain as reflected in the morphology of the skeletal cranial base. Their findings reveal that the human temporal lobes, involved in language, memory and social functions as well as the olfactory bulbs are relatively larger in Homo sapiens than in Neanderthals.

Antioxidant has potential in the Alzheimer's fight

Posted: 14 Dec 2011 06:48 AM PST

A new study has shown that an antioxidant can delay the onset of all the indicators of Alzheimer's disease, including cognitive decline. The researchers administered an antioxidant compound called MitoQ to mice genetically engineered to develop Alzheimer's.

Complex sex life of goats could have implications for wildlife management

Posted: 14 Dec 2011 06:48 AM PST

A new study of the mating habits of mountain goats reveals the vastly different strategies of males in different populations and could shed light on the unseen impacts of hunting.

Simple test to help diagnose bowel and pancreatic cancer could save thousands of lives

Posted: 14 Dec 2011 06:48 AM PST

A simple online calculator could offer family GPs a powerful new tool in tackling two of the most deadly forms of cancer, say researchers.

Increasing atmospheric concentrations of new flame retardants found

Posted: 14 Dec 2011 06:48 AM PST

Compounds used in new flame-retardant products are showing up in the environment at increasing concentrations, according to a recent study.

Is attention in females different?

Posted: 14 Dec 2011 06:46 AM PST

Is attention in women different from attention in men? Researchers investigated the effects of the hormone estrogen on spontaneous attention. They were hoping in this way to explain differences between the sexes. Women turned out to only be different from men when they had a high level of estrogen during their menstrual cycle.

Melting glaciers reveal future alpine world

Posted: 14 Dec 2011 06:46 AM PST

In a hundred years trees may be growing where there are now glaciers. The warm climate of the last few years has caused dramatic melting of glaciers in the Swedish mountains. Remains of trees that have been hidden for thousands of years have been uncovered. They indicate that 13,000 years ago there were trees where there are now glaciers. The climate may have been as much as 3.5 degrees warmer than now. In other words, this can happen again, according to a new study.

Microbial contamination found in orange juice squeezed in bars and restaurants, Spanish study suggests

Posted: 14 Dec 2011 06:46 AM PST

Scientists have analyzed fresh orange juice squeezed by machines in catering establishments. They have confirmed that 43% of samples exceeded the acceptable enterobacteriaceae levels laid down by legislation. The researchers recommend that oranges are handled correctly, that juicers are washed properly and that the orange juice is served immediately rather than being stored in metal jugs.

Caffeine study shows sport performance increase

Posted: 14 Dec 2011 06:45 AM PST

Caffeine combined with carbohydrate could be used to help athletes perform better on the field, according to new research.

Life on Kosterhavet's seabed analyzed

Posted: 14 Dec 2011 06:45 AM PST

Kosterhavet National Park was created to provide a haven for both protected species and nature lovers. Now researchers have analyzed species living on the seabed (benthic species) in the marine national park to determine which marine areas require special protection.

Why buttercups reflect yellow on chins: Research sheds light on children’s game and provides insight into pollination

Posted: 13 Dec 2011 05:33 PM PST

Scientists have found that the distinctive glossiness of the buttercup flower, which children like to shine under the chin to test whether their friends like butter, is related to its unique anatomical structure.

Endangered orangutans offer a new evolutionary model for early humans

Posted: 13 Dec 2011 05:33 PM PST

Studying how the orangutans cope with a harsh environment may offer a glimpse into what early human ancestors faced, new research suggests.

'Pep talk' can revive immune cells exhausted by chronic viral infection

Posted: 13 Dec 2011 04:02 PM PST

Chronic infections by viruses such as HIV or hepatitis C eventually take hold because they wear the immune system out, a phenomenon immunologists describe as exhaustion. Yet exhausted immune cells can be revived after the introduction of fresh cells that act like coaches giving a pep talk, researchers have found.

Potential explanation for mechanisms of associative memory

Posted: 13 Dec 2011 04:00 PM PST

Researchers have discovered that a chemical compound in the brain can weaken the synaptic connections between neurons in a region of the brain important for the formation of long-term memories. The findings may also provide a potential explanation for the loss of memory associated with Alzheimer's.

ليست هناك تعليقات:

إرسال تعليق