Τετάρτη 2 Απριλίου 2014

ScienceDaily: Top News

ScienceDaily: Top News


Deforestation of sandy soils a greater climate threat

Posted: 01 Apr 2014 01:22 PM PDT

A new study finds that tree removal has far greater consequences for climate change in some soils than in others, a finding that could provide key insights into which ecosystems should be managed with extra care. In a comprehensive analysis of soil collected from 11 distinct U.S. regions, from Hawaii to northern Alaska, researchers found that the extent to which deforestation disturbs underground microbial communities that regulate the loss of carbon into the atmosphere depends almost exclusively on the texture of the soil.

Overuse of blood transfusions increases infection risk

Posted: 01 Apr 2014 01:21 PM PDT

The fewer the red blood cell transfusions, the less likely patients were to develop infections like pneumonia, a new study has illustrated. Elderly patients undergoing hip or knee surgeries were most susceptible, with a 30 percent lower risk of infection when fewer transfusions were used. Overall, for every 38 hospitalized patients considered for a red blood cell transfusion (RBC), one patient would be spared a serious infection if fewer transfusions were used.

Epilepsy drug target implications for sleep disruption in brain disorders

Posted: 01 Apr 2014 11:21 AM PDT

A study using the mutant fruitfly sleepless confirmed that the enzyme GABA transaminase, a target of some epilepsy drugs, contributes to sleep loss. The findings shed light on mechanisms that may be shared between sleep disruption and some neurological disorders. A better understanding of this connection could enable treatments that target both types of symptoms and perhaps provide better therapeutic efficacy.

Twenty Years Later: How Breast Cancer Risk Genes are Changing Patient Care

Posted: 01 Apr 2014 11:21 AM PDT

In the mid-1990s, scientists for the first time were able to isolate and clone the BRCA1 and BRCA2 genes, mutations in which were thought to increase susceptibility to early onset breast and ovarian cancers. A article takes a look back at the last twenty years to show how the identification of these genes set in motion a firestorm of research aimed at exploring how genetic information can be used to create both standards of care and strategies for all patients at a high-risk of developing cancer.

Misleading mineral may have resulted in overestimate of water in moon

Posted: 01 Apr 2014 10:11 AM PDT

The amount of water present in the moon may have been overestimated by scientists studying the mineral apatite, researchers have discovered. For decades, scientists believed the moon was almost entirely devoid of water. However, the discovery of hydrogen-rich apatite within lunar rocks in 2010 seemed to hint at a more watery past. Scientists originally assumed that information obtained from a small sample of apatite could predict the original water content of a large body of magma, or even the entire moon, but a new study indicates that apatite may, in fact, be deceptive.

Good vibrations: Using light-heated water to deliver drugs

Posted: 01 Apr 2014 10:10 AM PDT

A new mechanism for using light to activate drug-delivering nanoparticles and other targeted therapeutic substances inside the body has been developed by a collaboration of materials scientists, engineers and neurobiologists. This discovery represents a major innovation. Up to now, only a handful of strategies using light-triggered release from nanoparticles have been reported.

Factor present in gestational, type 2 diabetes could provide new treatment options

Posted: 01 Apr 2014 09:23 AM PDT

Both pregnant women with diabetes and with type 2 diabetics have high levels of a fat metabolite that impairs pancreatic cells from secreting insulin. These findings suggest that blocking the effects of this fat metabolite may help prevent and treat diabetes.

'Sewing machine' idea gives insight into origins of Alzheimer's

Posted: 01 Apr 2014 09:23 AM PDT

A new imaging tool inspired by the humble sewing machine has been invented, providing fresh insight into the origins of Alzheimer's and Parkinson's disease. These diseases are caused by tiny toxic proteins too small to be studied with traditional optical microscopy.

Enhanced autopilot system could help prevent accidents like 2009 Air France 447 crash

Posted: 01 Apr 2014 09:23 AM PDT

Thirty lines of computer code might have saved Air France flight 447, and 228 passengers and crew aboard, from plunging into the Atlantic Ocean on June 1, 2009, according to new research. Scientists have now developed a computer system that detects and corrects faulty airspeed readings, such as those that contributed to the AF447 crash. Their approach to detecting errors could be applicable in many systems that rely on sensor readings.

Common molecular defect offers treatment hope for group of rare disorders

Posted: 01 Apr 2014 09:23 AM PDT

Researchers studying tiny, antennae-like structures called cilia have found a potential way to ease some of the physical damage of numerous genetic disorders that result when these essential cellular components are defective. Different genetic defects cause dysfunction of the cilia, which often act as sensory organs that receive signals from other cells. Individually, disorders involving cilia are rare, but collectively the more than 100 diseases in the category known as ciliopathies affect as many as one in 1,000 people.

Overcoming structural uncertainty in computer models

Posted: 01 Apr 2014 08:21 AM PDT

A computer model is a representation of the functional relationship between one set of parameters, which forms the model input, and a corresponding set of target parameters, which forms the model output. A true model for a particular problem can rarely be defined with certainty. The most we can do to mitigate error is to quantify the uncertainty in the model. Scientists have now offered a method to incorporate judgments into a model about structural uncertainty that results from building an 'incorrect' model.

Breast milk and diet up to two years old: A means of preventing the risk of child obesity

Posted: 01 Apr 2014 08:21 AM PDT

Scientists have shown that breast-feeding has a protective effect on the risk of obesity at 20 years of age. Researchers also emphasize that nutritional intake at the age of 2 years are critical in providing this beneficial effect.

Human 'hairless' gene identified: One form of baldness explained

Posted: 01 Apr 2014 08:21 AM PDT

It's not a hair-brained idea: A new research report explains why people with a rare balding condition called 'atrichia with papular lesions' lose their hair, and it identifies a strategy for reversing this hair loss. "Identification of hairless as a histone demethylase may shed new insights into its mechanism of action in regulating skin and hair disorders," said the lead author.

Scientists solve the riddle of zebras' stripes: Those pesky bugs

Posted: 01 Apr 2014 08:21 AM PDT

Why zebras have black and white stripes is a question that has intrigued scientists and spectators for centuries. Scientists now examined this riddle systematically.

Humans and saber-toothed tiger met in Germany 300,000 years ago

Posted: 01 Apr 2014 08:20 AM PDT

Scientists excavating at the Schöningen open-cast coal mine in north-central Germany have discovered the remains of a saber-toothed cat preserved in a layer some 300,000 years old -- the same stratum in which wooden spears were found, indicating that early humans also inhabited the area, which at that time was the bank of a shallow lake.

Wind energy: New insight into best arrangement of wind turbines on large installations

Posted: 01 Apr 2014 08:19 AM PDT

Researchers have developed a new way to study wake effects that includes the airflow both within and around a wind farm and challenges the conventional belief that turbines arrayed in checker board patterns produce the highest power output. Their study provides insight into factors that determine the most favorable positioning.

Monkey caloric restriction study shows big benefit; contradicts earlier study

Posted: 01 Apr 2014 08:19 AM PDT

The latest results from a 25-year study of diet and aging in monkeys shows a significant reduction in mortality and in age-associated diseases among those with calorie-restricted diets. The study, begun in 1989, is one of two ongoing, long-term U.S. efforts to examine the effects of a reduced-calorie diet on nonhuman primates.

Jamaican iguana: Sobering update on Jamaica's largest vertebrate

Posted: 01 Apr 2014 07:30 AM PDT

The Jamaican iguana continues to be critically endangered, with only a single location left for the recovering population in the Portland Bight Protected Area. A recent proposal by Jamaican government officials to allow extensive development in this area is causing concern among conservationists who have been working to save this species and the wealth of biodiversity in the area.

Clinical trial results inconsistently reported among journals, government website, study suggests

Posted: 01 Apr 2014 07:30 AM PDT

Medical researchers often presented the findings of their clinical trials in a different way on a federal government website than they did in the medical journals where their studies were ultimately published, according to a recent analysis.

Better way to grow motor neurons from stem cells

Posted: 01 Apr 2014 07:29 AM PDT

Researchers report they can generate human motor neurons from stem cells much more quickly and efficiently than previous methods allowed. The finding will aid efforts to model human motor neuron development, and to understand and treat spinal cord injuries and motor neuron diseases such as amyotrophic lateral sclerosis.

Carbon nanotubes grow in combustion flames

Posted: 01 Apr 2014 07:29 AM PDT

Quantum chemical simulations reveal an unprecedented relationship between the mechanism of carbon nanotube growth and hydrocarbon combustion processes. Results of these simulations illustrate the importance in the role of carbon chemical bonding and molecular transformations in CNT growth.

New yeast species travelled the globe with a little help from the beetles

Posted: 01 Apr 2014 07:27 AM PDT

A new globe-trotting yeast species that lives on tree-associated beetles has been discovered by scientists. This new species demonstrates the importance of preserving biodiversity, as yeasts like this may help efforts to develop renewable fuel sources in the future. "This new species is a real globetrotter," said an author. "It's possible the yeast originated in Asia, and was subsequently brought to the USA by these insects."

Lose the paunch, halt the hair loss?

Posted: 01 Apr 2014 07:27 AM PDT

A new discovery showing how hair growth activated fat tissue growth in the skin below the hair follicle could lead to the development of a cream to dissolve fat. The world first research confirmed that changes in the hair growth cycle led to fluctuations in the thickness of the underlying fat layer of the skin -- essentially meaning that the skin can regulate fat production.

Knowledge transfer between computers: Computers teach each other Pac-Man

Posted: 01 Apr 2014 07:27 AM PDT

Researchers have developed a method to allow a computer to give advice and teach skills to another computer in a way that mimics how a real teacher and student might interact. Researchers had the agents -- as the virtual robots are called -- act like true student and teacher pairs: student agents struggled to learn Pac-Man and a version of the StarCraft video game. The researchers were able to show that the student agent learned the games and, in fact, surpassed the teacher.

Need to regulate antimicrobial ingredients in consumer products, scientific evidence shows

Posted: 01 Apr 2014 07:25 AM PDT

Does the widespread and still proliferating use of antimicrobial household products cause more harm than good to consumers and the environment? Evidence compiled shows that decades of widespread use of antimicrobials has left consumers with no measurable benefits. Worse yet, lax regulation has caused widespread contamination of the environment, wildlife and human populations with compounds that appear more toxic than safe, according to recent scientific research.

Electrical transmission at atomic level: New approach to building signal processing components from individual atoms

Posted: 01 Apr 2014 07:23 AM PDT

In a study on the transport of atoms in ultracold gases, a team of physicists has developed a new approach to how signals might be transmitted at the atomic level. This could be especially important for realizing logic structures with strictly defined functions on the basis of individual atoms, which in turn could find application in transistors or diodes.

Attention changes in the course of a dog's life mirror those of humans

Posted: 01 Apr 2014 07:22 AM PDT

Dogs are known to be 'Man's best friend'. No other pet has adjusted to human lifestyles as well as this four-legged animal. Scientists have been the first to investigate the evolution of dogs' attentiveness in the course of their lives and to what extent they resemble humans in this regard. The outcome: dogs' attentional and sensorimotor control developmental trajectories are very similar to those found in humans.

Switching brain cells with less light

Posted: 01 Apr 2014 07:22 AM PDT

Networked nerve cells are the control center of organisms. In a nematode, 300 nerve cells are sufficient to initiate complex behavior. To understand the properties of the networks, researchers switch cells on and off with light and observe the resulting behavior of the organism. Scientists now present a protein that facilitates the control of nerve cells by light. It might be used as a basis of studies of diseases of the nervous system.

Universal syllables: Some innate preferences shape the sound of words from birth

Posted: 01 Apr 2014 07:21 AM PDT

Languages are learned, it's true, but are there also innate bases in the structure of language that precede experience? Linguists have noticed that, despite the huge variability of human languages, there are some preferences in the sound of words that can be found across languages.  So they wonder whether this reflects the existence of a universal, innate biological basis of language. A new study provides evidence to support to this hypothesis, demonstrating that certain preferences in the sound of words are already active in newborn infants.

Higher risk of death from skin cancer among men living alone

Posted: 01 Apr 2014 07:21 AM PDT

There are differences in prognosis in cutaneous malignant melanoma depending on cohabitation status and gender, according to a new study. Single men of all ages are more likely to die of their disease. According to the researchers, one possible explanation could relate to insufficient access to skin examinations.

Corals don’t lie: Centuries of rising sea levels and temperature data revealed

Posted: 01 Apr 2014 07:21 AM PDT

Scientists have analyzed coral cores from the eastern Indian Ocean to understand how the unique coral reefs of Western Australia are affected by changing ocean currents and water temperatures. The findings give new insights into how La Niña, a climate swing in the tropical Pacific, affects the Leeuwin current and how our oceans are changing.

Genes identified that could lead to tough, disease-resistant varieties of rice

Posted: 01 Apr 2014 07:14 AM PDT

A meta-data analysis has uncovered more than 1,000 genes in rice that may be key targets for developing new strains of super rice. In an era of climate change, pollution, a growing population and the global spread of pathogens, new grains must be able to handle stress. Now, researchers have identified a set of genes that could be key to the development of the next generation of super rice.

Why vitamin D deficiency diagnoses surged

Posted: 01 Apr 2014 07:14 AM PDT

Physicians are ordering vitamin D deficiency screening tests for preventive care purposes rather than after patients develop conditions caused by decreased bone density, a study has concluded. For older patients, having a low vitamin D level is a condition that can cause weakening of bones, which can lead to fractures, and in children the deficiency can lead to rickets.

Want spring allergy relief? Avoid stress

Posted: 01 Apr 2014 07:14 AM PDT

Stress doesn't cause allergies, but easing your mind might mean less allergy flare-ups this spring. According to a study, allergy sufferers with persistent stress experience more allergy flares. "Stress can cause several negative effects on the body, including causing more symptoms for allergy sufferers," said an allergist.

Eating seven or more portions of fruit and vegetables a day reduces your risk of death by 42 percent

Posted: 31 Mar 2014 04:40 PM PDT

Eating seven or more portions of fruit and vegetables a day reduces your risk of death at any point in time by 42 percent compared to eating less than one portion, reports a new study. This is the first study to link fruit and vegetable consumption with all-cause, cancer and heart disease deaths in a nationally-representative population, the first to quantify health benefits per-portion, and the first to identify the types of fruit and vegetable with the most benefit.

Arctic melt season lengthening, ocean rapidly warming

Posted: 31 Mar 2014 03:06 PM PDT

The length of the melt season for Arctic sea ice is growing by several days each decade, and an earlier start to the melt season is allowing the Arctic Ocean to absorb enough additional solar radiation in some places to melt as much as four feet of the Arctic ice cap's thickness, according to a new study.

Gratitude, not 'gimme,' makes for more satisfaction, study finds

Posted: 31 Mar 2014 03:06 PM PDT

People who are materialistic are more likely to be depressed and unsatisfied, in part because they find it harder to be grateful for what they have, according to a study. "Gratitude is a positive mood. It's about other people," said the study's lead author. "Previous research finds that people are motivated to help people that help them." But materialism tends to be "me-centered." A material outlook focuses on what one does not have, impairing the ability to be grateful for what one already has, researchers said.

Using more wood for construction can slash global reliance on fossil fuels

Posted: 31 Mar 2014 02:06 PM PDT

Increasing the wood harvest to the equivalent of 34 percent or more of annual wood growth to meet construction demands worldwide could drastically reduce the global reliance on fossil fuels while protecting biodiversity and carbon storage capacity, according to a new study.

Poor sleep quality linked to cognitive decline in older men

Posted: 31 Mar 2014 02:05 PM PDT

A link between poor sleep quality and the development of cognitive decline over three to four years was found in a new study of older men. Results show that higher levels of fragmented sleep and lower sleep efficiency were associated with a 40 to 50 percent increase in the odds of clinically significant decline in executive function, which was similar in magnitude to the effect of a five-year increase in age. In contrast, sleep duration was not related to subsequent cognitive decline.

Heart health as young adult linked to mental function in mid-life

Posted: 31 Mar 2014 02:05 PM PDT

Having blood pressure, blood sugar and cholesterol levels slightly higher than the recommended guidelines in early adulthood is associated with lower cognitive function in mid-life. "Our study is hopeful, because it tells us we could maybe make a dent in the risks of Alzheimer's and other forms of dementia by emphasizing the importance of controlling risk factors among younger people," researchers state.

Limiting screen time improves sleep, academics, behavior, study finds

Posted: 31 Mar 2014 02:04 PM PDT

Parents may not always see it, but efforts to limit their children's screen time can make a difference. A new study found children get more sleep, do better in school and see other health benefits when parents monitor screen time. The effect is not immediate and that makes it difficult for parents to recognize. As a result, parents may think it is not worth the effort to monitor and limit their children's media use. But researchers say they have more power than they realize.

First phononic crystal that can be altered in real time

Posted: 31 Mar 2014 12:36 PM PDT

Using an acoustic metadevice that can influence the acoustic space and can control any of the ways in which waves travel, engineers have demonstrated, for the first time, that it is possible to dynamically alter the geometry of a three-dimensional colloidal crystal in real time. The colloidal crystals designed in the study, called metamaterials, are artificially structured materials that extend the properties of existing naturally occurring materials and compounds.

Ancient whodunit may be solved: Methane-producing microbes did it!

Posted: 31 Mar 2014 12:36 PM PDT

Methane-producing microbes may be responsible for the largest mass extinction in Earth's history. Fossil remains show that sometime around 252 million years ago, about 90 percent of all species on Earth were suddenly wiped out -- by far the largest of this planet's five known mass extinctions. It turns out that Methanosarcina had acquired a particularly fast means of making methane, and the team's detailed mapping of the organism's history now shows that this transfer happened at about the time of the end-Permian extinction.

Self-healing engineered muscle grown in the laboratory

Posted: 31 Mar 2014 12:36 PM PDT

Living skeletal muscle that contracts powerfully and rapidly, integrates quickly into mice, and for the first time, demonstrates the ability to heal itself both inside the laboratory and inside an animal has been grown in the lab by biomedical engineers. "The muscle we have made represents an important advance for the field," an author said. "It's the first time engineered muscle has been created that contracts as strongly as native neonatal skeletal muscle."

Experimental cancer drug reverses schizophrenia in adolescent mice

Posted: 31 Mar 2014 12:35 PM PDT

An experimental anticancer compound appears to have reversed behaviors associated with schizophrenia and restored some lost brain cell function in adolescent mice with a rodent version of the devastating mental illness. The drug is one of a class of compounds known as PAK inhibitors, which have been shown in animal experiments to confer some protection from brain damage due to Fragile X syndrome, an inherited disease in humans marked by mental retardation.

Computer maps 21 distinct emotional expressions -- even 'happily disgusted'

Posted: 31 Mar 2014 12:35 PM PDT

Researchers have found a way for computers to recognize 21 distinct facial expressions -- even expressions for complex or seemingly contradictory emotions such as "happily disgusted" or "sadly angry." The study more than triples the number of documented facial expressions that researchers can now use for cognitive analysis.

Cheap, better-performing lithium-ion batteries created

Posted: 31 Mar 2014 11:41 AM PDT

Researchers have developed a cheap, high-performing silicon anode and sulfur-based cathode for lithium-ion batteries. Lithium-ion batteries are a popular type of rechargeable battery commonly found in portable electronics and electric or hybrid cars. Scientists have developed a cost-effective (and therefore commercially viable) silicon anode nearly three times more powerful and longer lasting than a typical commercial anode.

Satellite shows high productivity from U.S. corn belt

Posted: 31 Mar 2014 10:10 AM PDT

Data from satellite sensors show that during the Northern Hemisphere's growing season, the Midwest region of the United States boasts more photosynthetic activity than any other spot on Earth, according to scientists. Healthy plants convert light to energy via photosynthesis, but chlorophyll also emits a fraction of absorbed light as fluorescent glow that is invisible to the naked eye. The magnitude of the glow is an excellent indicator of the amount of photosynthesis, or gross productivity, of plants in a given region.

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