Παρασκευή, 2 Μαΐου 2014

ScienceDaily: Latest Science News

ScienceDaily: Latest Science News


Stimulated mutual annihilation: How to make a gamma-ray laser with positronium

Posted: 01 May 2014 01:56 PM PDT

Theorists expect that positronium, a sort of 'atom' consisting of an electron and an anti-electron, can be used to make a powerful gamma-ray laser. Scientists now report detailed calculations of the dynamics of a positronium BEC. This work is the first to account for effects of collisions between different positronium species. These collisions put important constraints on gamma-ray laser operation.

Missing piece of biogeochemical puzzle in aquifers discovered

Posted: 01 May 2014 01:56 PM PDT

New research may dramatically shift our understanding of the complex dance of microbes and minerals that takes place in aquifers deep underground. This dance affects groundwater quality, the fate of contaminants in the ground and the emerging science of carbon sequestration.

Excessive regulations turning scientists into bureaucrats

Posted: 01 May 2014 01:56 PM PDT

Excessive regulations are consuming scientists' time and wasting taxpayer dollars, says a new report. Thousands of federally funded scientists responded to a request to identify requirements they believe unnecessarily increase their administrative workload.

Undersea warfare: Viruses hijack deep-sea bacteria at hydrothermal vents

Posted: 01 May 2014 12:10 PM PDT

More than a mile beneath the ocean's surface, as dark clouds of mineral-rich water billow from seafloor hot springs called hydrothermal vents, unseen armies of viruses and bacteria wage war.

Nanoelectronics: Edgy look at 2-D molybdenum disulfide

Posted: 01 May 2014 12:10 PM PDT

Researchers have recorded the first observations of a strong nonlinear optical resonance along the edges of single layers of molybdenum disulfide that could be key to the use of this and similar 2-D semiconductors in future nanoelectronic devices.

Age, general health, antidepressant use linked to eye disorders

Posted: 01 May 2014 12:10 PM PDT

Abnormal binocular vision, which involves the way eyes work together as a team, increases dramatically as we age, according to research. The study also found a correlation between this condition, general health and antidepressant use. As many as 27 per cent of adults in their sixties have an actual binocular vision or eye movement disorder. That number rises to 38 per cent for those over age 80. About 20 per cent of the general population suffers from a binocular vision disorder, which affects depth perception and therefore may increase the risk of falls.

Whales hear us more than we realize: Sonar signal 'leaks' likely audible to some marine mammals

Posted: 01 May 2014 12:09 PM PDT

Killer whales and other marine mammals likely hear sonar signals more than we've known. That's because commercially available sonar systems, which are designed to create signals beyond the range of hearing of such animals, also emit signals known to be within their hearing range, scientists have discovered.

Spinal cord neurons that control skilled limb movement identified

Posted: 01 May 2014 11:22 AM PDT

Two types of neurons that enable the spinal cord to control skilled forelimb movement have been found by researchers. The first is a group of excitatory interneurons that are needed to make accurate and precise movements; the second is a group of inhibitory interneurons necessary for achieving smooth movement of the limbs. The findings are important steps toward understanding normal human motor function and potentially treating movement disorders that arise from injury or disease.

Increased drought portends lower future Midwestern U.S. crop yields

Posted: 01 May 2014 11:22 AM PDT

Increasingly harsh drought conditions in the US Midwest's Corn Belt may take a serious toll on corn and soybean yields over the next half-century, according to new research. Corn yields could drop by 15 to 30 percent, according to the paper's estimates.

Delving deep into the brain: MRI sensor allows neuroscientists to map neural activity with molecular precision

Posted: 01 May 2014 11:22 AM PDT

An MRI sensor now allows neuroscientists to map neural activity with molecular precision. This is the first time anyone has been able to map neural signals with high precision over large brain regions in living animals, offering a new window on brain function, says the lead researcher. The new work focused on the study of the neurotransmitter dopamine in a region called the ventral striatum, which is involved in motivation, reward, and reinforcement of behavior.

Climate change study reveals unappreciated impacts on biodiversity

Posted: 01 May 2014 11:22 AM PDT

The tropics ill be highly affected by local changes in temperature and precipitation, leading to novel climates with no current analogues in the planet. These results expose the complexities of climate change effects on biodiversity and the challenges in predicting and preserving natural ecosystems in a changing Earth.

Breaking up water: Controlling molecular vibrations to produce hydrogen

Posted: 01 May 2014 11:22 AM PDT

Converting methane into hydrogen is crucial for clean energy and agriculture. This reaction requires water and a catalyst. Scientists have now used a novel laser approach to control specific vibrations of a water molecule, which can affect the efficiency of the reaction.

Decoding the chemical vocabulary of plants

Posted: 01 May 2014 11:22 AM PDT

Plants spend their entire lifetime rooted to one spot. When faced with a bad situation, such as a swarm of hungry herbivores or a viral outbreak, they have no option to flee but instead must fight to survive. What is the key to their defense? Chemistry. Understanding how plants evolved this prodigious chemical vocabulary has been a longstanding goal in plant biology.

'Remodelling' damaged nuclei: Discovery could lead to new treatments for accelerated aging disease

Posted: 01 May 2014 11:22 AM PDT

Scientists have identified a key chemical that can repair the damage to cells which causes a rare but devastating disease involving accelerated aging. As well as offering a promising new way of treating the condition, known as Hutchinson-Gilford Progeria Syndrome, the discovery could help in the development of drugs against cancer and other genetic diseases and might also suggest ways to alleviate diseases that we associate with normal aging.

Jupiter's moon Ganymede may harbor 'club sandwich' of oceans and ice

Posted: 01 May 2014 11:07 AM PDT

The largest moon in our solar system, a companion to Jupiter named Ganymede, might have ice and oceans stacked up in several layers like a club sandwich, according to new NASA-funded research that models the moon's makeup.

For some, money will not buy happiness: Neither life experiences nor material items make materialistic shoppers happier

Posted: 01 May 2014 10:26 AM PDT

Many shoppers, regardless of whether they buy life experiences or material items, are no happier following the purchase than they were before, a new study finds. These shoppers -- about a third of the population -- appear to be an exception to previous research that has found buying experiences will make an individual happier. Researchers found the happiness boost from experiences is often negated for material buyers because the purchase doesn't reflect their personality.

Compounds that control hemorrhagic viruses identified

Posted: 01 May 2014 10:26 AM PDT

Compounds that could reduce the ability of viruses that cause diseases such as Ebola, rabies, HIV and Lassa fever to spread infection have been identified and developed by veterinarian scientists. People fear diseases such as Ebola, Marburg, Lassa fever, rabies and HIV for good reason; they have high mortality rates and few, if any, possible treatments. As many as 90 percent of people who contract Ebola, for instance, die of the disease. These new prototypic compounds have the potential to one day serve as broad-spectrum anti-viral drugs.

Noncombat injury top reason for pediatric care by military surgeons in Afghanistan, Iraq

Posted: 01 May 2014 10:26 AM PDT

Noncombat-related injury -- caused by regular car accidents, falls and burns -- is the most common reason for pediatric admissions to US military combat hospitals in both Iraq and Afghanistan reveals new study findings. The primary role of a combat military hospital is to care for all sick and wounded soldiers during wartime. However, the Geneva Convention specifies that an occupying force must ensure, to the greatest extent possible, the public health of the civilian population.

Real difference between how men, women choose partners

Posted: 01 May 2014 10:26 AM PDT

A hamburger that's 90 percent fat-free sounds a lot better than one with 10 percent fat. And even when the choices are the same, humans are hard-wired to prefer the more positive option. This is because of what's known as the 'framing effect,' a principle that new research has proved, applies to mate selection, too.

Nearby galaxy is a 'fossil' from the early universe

Posted: 01 May 2014 10:26 AM PDT

Scientists analyzed the chemical elements in the faintest known galaxy, called Segue 1, and determined that it is effectively a fossil galaxy left over from the early universe. Stars form from gas clouds and their composition mirrors the chemical composition of the galactic gas from which they were born.

Small changes could save structures, lives during tornadoes: Safe rooms, quality garage doors critical

Posted: 01 May 2014 10:25 AM PDT

Surviving a tornado in a wood-frame residential home is enhanced by an intact roof and standing walls, but light-weight garage doors can be the weak link to allowing high winds and pressure changes into a home that can lead to the removal of the roof and collapsed walls, according to a study of damage left behind by a powerful tornado in Moore, Oklahoma, in 2013.

Alcohol use before pregnancy linked to intestinal birth defect

Posted: 01 May 2014 10:25 AM PDT

Women should refrain from drinking alcohol before they try to become pregnant, according to maternal-fetal medicine specialists. Alcohol is associated with an increased risk for mental delays, cardiac anomalies and facial clefting in babies. In a recent study, researchers also found that alcohol is linked to gastroschisis, a birth defect of the baby's abdominal wall. "Preconception programs focused on alcohol abstinence may help to reverse the increasing incidence of this birth defect worldwide," said one researcher.

First ever gravitationally lensed Type Ia supernovae discovered

Posted: 01 May 2014 10:25 AM PDT

Astronomers have discovered three distant exploding stars that have been magnified by the immense gravity of foreground galaxy clusters, which act like 'cosmic lenses.' These supernovae are the first of their type ever to be observed magnified in this way and they offer astronomers a powerful tool to check the prescription of these massive lenses.

Standard assessments miss early signs of cardiovascular disease in firefighters

Posted: 01 May 2014 09:52 AM PDT

Traditional first-line checks of such heart disease risk factors as cholesterol, blood pressure and smoking habits aren't nearly good enough to identify cardiovascular disease in otherwise healthy, young firefighters, according to results of a small study. Previous studies have found that cardiovascular disease accounts for 45 percent of deaths of on-duty firefighters nationwide, in contrast to 15 percent of deaths among those with conventional occupations, with heart attack being the number one cause of death.

Hyperfractionated radiation therapy improves local-regional control for patients with head, neck cancer

Posted: 01 May 2014 09:52 AM PDT

Patients with locally advanced squamous cell carcinoma of the head and neck treated with hyperfractionated radiation therapy experienced improved local-regional control and, with patients censored at five years, improved overall survival with no increase in late toxicity, according to a study.

Stem cells from some infertile men form germ cells when transplanted into mice

Posted: 01 May 2014 09:34 AM PDT

Stem cells made from the skin of adult, infertile men yield primordial germ cells -- cells that normally become sperm -- when transplanted into the reproductive system of mice, according to new research.

Humans have a nose for gender: Chemical cues influence perceptions of movement as more masculine or feminine

Posted: 01 May 2014 09:34 AM PDT

The human body produces chemical cues that communicate gender to members of the opposite sex, according to new research. Whiffs of the active steroid ingredients (androstadienone in males and estratetraenol in females) influence our perceptions of movement as being either more masculine or more feminine. The effect, which occurs completely without awareness, depends on both our biological sex and our sexual orientations.

Malnutrition during pregnancy may affect the health of future generations

Posted: 01 May 2014 09:34 AM PDT

New research reveals how environmental factors in the womb can predispose not only the mother's own offspring but also the grand-offspring to metabolic disorders like liver disease. Researchers found for pregnant mice that are malnourished that their offspring are at first growth restricted and have low birth weight but then go on to become obese and diabetic as they age. Strikingly, the offspring of the growth-restricted males are predisposed to metabolic abnormalities.

Landscape architect designs toolkit to make cities inclusive of adults with autism

Posted: 01 May 2014 09:34 AM PDT

An urban toolkit that help designers and planners make cities more inclusive for adults with autism has been developed by a landscape architect. The National Institutes of Health has identified six needs for adults with autism: vocational training, life skills, mental and physical health support, employment, public transportation and affordable housing. This urban toolkit addresses these needs because many cities do not have adequate services for adults with autism.

Staying power of HIV-fighting enzyme figured out

Posted: 01 May 2014 09:34 AM PDT

Biochemists have figured out what is needed to activate and sustain the virus-fighting activity of an enzyme found in CD4+ T cells, the human immune cells infected by HIV. The discovery could launch a more effective strategy for preventing the spread of HIV.

New combination therapy developed for multiple myeloma

Posted: 01 May 2014 08:23 AM PDT

Each year, more than 25,000 Americans are diagnosed with multiple myeloma, a form of blood cancer that often develops resistance to therapies. However, researchers are reporting promising results from laboratory experiments testing a new combination therapy that could potentially overcome the resistance hurdle.

Experimental drug prolongs life span in mice

Posted: 01 May 2014 08:23 AM PDT

Scientists newly identified a protein's key role in cell and physiological aging and have developed an experimental drug that inhibits the protein's effect and quadrupled the lifespan in a mouse model of accelerated aging. Their lungs and vascular system were protected from rapid aging. The experimental drug could potentially be used to treat human diseases that cause accelerated aging such as chronic kidney disease, diabetes and HIV infection and even extend someone's healthy life.

Risk of weight gain deters some smokers from seeking treatment to quit

Posted: 01 May 2014 08:23 AM PDT

Smokers may avoid treatment to quit smoking if they previously gained weight while trying to quit, according to researchers. Weight gain is a predictable occurrence for smokers who have recently quit. Within the first year after quitting, they gain an average of eight to 14 pounds, and some smokers report that they keep smoking simply because they do not want to gain weight from quitting.

Unlocking mystery of thalidomide's malformation of limbs

Posted: 01 May 2014 08:17 AM PDT

Shortly after thalidomide was released to market in the 1950s, a reported 10,000 infants were born with an extreme form of a rare congenital syndrome -- phocomelia -- which caused death in 50 percent of cases. Now, half a century later, new research has identified a regulator responsible for the malformation of limbs in phocomelia, pinpointing a specific target for possible future intervention.

Accelerator for molecular machines discovered

Posted: 01 May 2014 08:17 AM PDT

How hard can it be to make a wheel rotate in a machine? Very hard actually, when the wheel sits in one of those nano-small molecular machines that are predicted to be running our future machines. But before the molecular machines become part of our daily lives, researchers must be able to control them. Scientists have now solved part of this problem.

Antimicrobial edible films inhibit pathogens in meat

Posted: 01 May 2014 08:17 AM PDT

Antimicrobial agents incorporated into edible films applied to foods to seal in flavor, freshness and color can improve the microbiological safety of meats, according to new research.

Individual brain activity predicts tendency to succumb to daily temptations

Posted: 01 May 2014 08:17 AM PDT

Activity in areas of the brain related to reward and self-control may offer neural markers that predict whether people are likely to resist or give in to temptations, like food, in daily life, according to new research.

Rules of thumb: Three simple ideas for overcoming childhood obesity

Posted: 01 May 2014 08:17 AM PDT

A new approach to overcome the complex problem of childhood obesity and related mental disorders has been published by one expert. Using heuristics, or mental shortcuts, the approach can be used for both treatment and prevention. His "rules," meant to facilitate healthy choices, are straightforward and practical.

Killing Kindlin-3 to cure breast cancer: 'Blood' protein implicated

Posted: 01 May 2014 08:17 AM PDT

A protein believed to be limited to the hematopoietic system, called Kindlin-3, has been identified as a major player in both the formation and spread of breast cancer to other organs. This discovery could open the door to an entirely new class of breast cancer drugs that targets this protein's newly found activity.

New molecule links asthma, cancer; could aid in developing new treatments

Posted: 01 May 2014 08:17 AM PDT

A newly discovered molecule provides a new drug target for controlling both asthma-induced muscle thickening and cancerous tumor growth. This molecule, called "microRNA-10a," normally helps genes produce proteins or make copies of themselves, also play an important role in the growth or overgrowth of human airway smooth muscle cells and some forms of cancer.

Human rights report card released

Posted: 01 May 2014 07:12 AM PDT

Real freedom, gender-based violence, terrorism laws, and asylum seekers' rights are all considered in a report released today on vital human rights issues in Australia and around the world. Specific to Australia, a key finding of the report is that freedom in Australia is being undermined.

When it comes to classes, small is better

Posted: 01 May 2014 07:12 AM PDT

Small classes, especially in the first four years of school, can have an important and lasting impact on student achievement, a new report shows. In a review of over 100 papers from 1979-2014, an education expert looked at whether the conclusions reached on the effect of smaller class sizes still hold true today. "Smaller classes in the early years can lift a child's academic performance right through to Year 12 and even into tertiary study and employment," he concluded.

Climate change to intensify important African weather systems

Posted: 01 May 2014 07:12 AM PDT

Climate change could strengthen African easterly waves, which could in turn have consequences for rainfall in the Sahel region of northern Africa, formation of Atlantic hurricanes and dust transport across the Atlantic Ocean.

Playing outside could make kids more spiritual

Posted: 01 May 2014 07:11 AM PDT

Children who spend significant time outdoors could have a stronger sense of self-fulfillment and purpose than those who don't, according to new research linking children's experiences in nature with how they define spirituality. "These values are incredibly important to human development and well-being," said a co-author. "We were surprised by the results. Before we did the study, we asked, 'Is it just a myth that children have this deep connection with nature?' But we found it to be true in pretty profound ways."

China study improves understanding of disease spread

Posted: 01 May 2014 07:11 AM PDT

The travel and socialization patterns of people in Southern China can give greater insight into how new diseases such as bird flu may spread between populations. "The next flu pandemic may well come from Asia so the more we know now about how flu and other infections may spread in this region, the better prepared we are to limit them and save lives," authors concluded at the end of their study

Australian tsunami database reveals threat to continent

Posted: 01 May 2014 07:11 AM PDT

Australia's coastline has been struck by up to 145 possible tsunamis since prehistoric times, triple the previously estimated number, a new study reveals. The largest recorded inundation event in Australia was caused by an earthquake off Java in 2006. The continent was also the site of the oldest known tsunami in the world -- an asteroid impact 3.47 billion years ago. Details of the 145 modern day and prehistoric events are outlined in a revised tsunami database.

New rapid synthesis developed for bilayer graphene and high-performance transistors

Posted: 01 May 2014 07:11 AM PDT

A research team has demonstrated a rapid synthesis technique for large-area Bernal -- or AB -- stacked bilayer graphene films that can open up new pathways for digital electronics and transparent conductor applications.

Tree rings reveal nightmare droughts in Western U.S.

Posted: 01 May 2014 07:11 AM PDT

Scientists extended Utah's climate record back to 1429 using tree rings. They found Utah's climate has seen extreme droughts, including one that lasted 16 years. If history is repeated in the rapidly growing Western states, the water supply would run out based on current consumption.

Low-fat diet helps fatigue in people with MS, study shows

Posted: 01 May 2014 07:11 AM PDT

People with multiple sclerosis who for one year followed a plant-based diet very low in saturated fat had much less MS-related fatigue at the end of that year -- and significantly less fatigue than a control group of people with MS who didn't follow the diet, according to a study. "Fatigue can be a debilitating problem for many people living with relapsing-remitting MS," said one researcher. "So this study's results -- showing some notable improvement in fatigue for people who follow this diet -- are a hopeful hint of something that could help many people with MS."

Pioneering forensics research into body fluids in sexual assaults

Posted: 01 May 2014 07:10 AM PDT

New techniques for identifying body fluids -- especially important in cases of alleged sexual assault -- have been pioneered by a PhD candiate, who has focused her studies on the topic. "If a male doesn't produce sperm, he doesn't produce DNA, so I am trying to differentiate between seminal fluid and semen so that I can strongly support the hypothesis that sexual intercourse did occur even if the DNA isn't present," she explains, adding that the ability to identify accurately the presence or absence of fluids at a crime scene could be vital to prove the innocence of an alleged offender -- in cases of false accusation -- as well as being an important prosecution tool.

Battle against drug smuggling: Physicist's new research lends a hand

Posted: 01 May 2014 07:10 AM PDT

Global security and the fight against crimes such as drug smuggling and weapons trafficking would be massively aided by an improved method of scanning cargoes for concealed items, suggests a researcher. A technology for this, based on the use of neutron beams, exists but is beset by problems.

Looks really can kill you: Protect yourself against skin cancer

Posted: 01 May 2014 07:09 AM PDT

It only takes a few bad sunburns or trips to the tanning bed to put someone at risk for melanoma. Skin cancer is the most common type of cancer in the United States and when left untreated, melanoma is the most dangerous and aggressive form. It accounts for more than 9,000 of the 12,000-plus skin cancer deaths each year. In observance of May's Melanoma and Skin Cancer Awareness Month, focus is turned to helping teens keep their skin safe this spring.

Amphibians in a vice: Climate change robs frogs, salamanders of refuge

Posted: 01 May 2014 07:09 AM PDT

Amphibians in the West's high-mountain areas find themselves caught between climate-induced habitat loss and predation from introduced fish. A novel combination of tools could help weigh where amphibians are in the most need of help.

'Til sickness do us part: How illness affects the risk of divorce

Posted: 01 May 2014 04:59 AM PDT

In the classic marriage vow, couples promise to stay together in sickness and in health. But a new study finds that the risk of divorce among older married couples rises when the wife -- but not the husband -- becomes seriously ill. "We found that women are doubly vulnerable to marital dissolution in the face of illness," researchers said. "They are more likely to be widowed, and if they are the ones who become ill, they are more likely to get divorced."

Network for tracking earthquakes exposes glacier activity: Accidental find offers big potential for research on Alaska's glaciers

Posted: 01 May 2014 04:59 AM PDT

Alaska's seismic network records thousands of quakes produced by glaciers, capturing valuable data that scientists could use to better understand their behavior, but instead their seismic signals are set aside as oddities. The current earthquake monitoring system could be 'tweaked' to target the dynamic movement of the state's glaciers.

New tool to aid in dolphin strandings

Posted: 01 May 2014 04:50 AM PDT

The cause of dolphin strandings has long been a mystery but a new study shows that clues about survival rates after release may be found in the sea mammal's blood. The study analyzed blood work and body condition values from stranded common dolphins and compared them with survival rates after release. Responders in the field are now using the blood and health data to make better release decisions and predict survival outcomes. "The establishment of these blood values provides a window into the overall health of the dolphin," said the paper's lead author. "Now we have a way to predict which stranded dolphins have a better chance of survival after release and this can help triage care."

Research could improve pharmaceuticals testing

Posted: 30 Apr 2014 04:28 PM PDT

An effort to develop a new technique for measuring moisture in pharmaceuticals is underway, which could be 100 times more sensitive than a popular current method. "The analysis for water in many consumer products, including drugs, is one of the most required tests done in the world," said the lead investigator. "Current methods have many shortcomings, including poor sensitivity and reproducibility; they cannot be used for all products and they can be time consuming. I believe our new 'ionic liquid' method offers improvements in all these areas."

Novel regulator of key gene expression in cancer identified

Posted: 30 Apr 2014 04:27 PM PDT

A key genetic switch linked to the development, progression and outcome of cancer has been discovered by scientists, a finding that may lead to new targets for cancer therapies. The switch, a string of nucleotides dubbed a long non-coding RNA (lncRNA), does not code for proteins like regular RNA. Instead, the scientists found, this particular lncRNA acts as an on/off switch for a key gene whose excessive activity is tied to inflammation and cancer, COX-2.

Cutting cancer to pieces: New research on bleomycin

Posted: 30 Apr 2014 04:27 PM PDT

Bleomycin's ability to cut through double-stranded DNA in cancerous cells, like a pair of scissors, has been described in a new article. Such DNA cleavage often leads to cell death in particular types of cancer cells. Bleomycin is part of a family of structurally related antibiotics produced by the bacterium, Streptomyces verticillus. Three potent versions of the drug, labeled A2 , A5 and B2 are the primary forms in clinical use against cancer.

Playing pool with carbon atoms: How to change the crystal structure of graphene

Posted: 30 Apr 2014 04:27 PM PDT

A discovery brings graphene -- thin layers of pencil 'lead' -- one step closer to replacing silicon in future technologies such as faster and smaller microprocessors. Graphene consists of extremely thin sheets of graphite: when writing with a pencil, graphene sheets slough off the pencil's graphite core and stick to the page. If placed under a high-powered electron microscope, graphene reveals its sheet-like structure of cross-linked carbon atoms, resembling chicken wire.

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