Σάββατο 8 Φεβρουαρίου 2014

ScienceDaily: Latest Science News

ScienceDaily: Latest Science News


Social or stinky? New study reveals how animal defenses evolve

Posted: 07 Feb 2014 12:13 PM PST

Some animals are "eww" while others are "aww." Why do some animals use stinking secretions for defense, while others are social? In a new study, researchers found that noxious spraying was favored by animals that were nocturnal and mostly at risk from other animals, while sociality was favored by animals that were active during the day and potentially vulnerable to birds of prey.

Europe's oldest footprints uncovered on English coast

Posted: 07 Feb 2014 10:45 AM PST

The earliest human footprints outside of Africa have been uncovered, on the English coast, by a team of scientists. Their discovery offers researchers an insight into the migration of pre-historic people hundreds of thousands of years ago when Britain was linked by land to continental Europe.

New application of physics tools used in biology

Posted: 07 Feb 2014 10:30 AM PST

A physicist and his colleagues have found a new application for the tools and mathematics typically used in physics to help solve problems in biology.

Delist gray wolf from threatened and endangered list? Panel issues report on science

Posted: 07 Feb 2014 10:30 AM PST

As the Endangered Species Act celebrated its 40th anniversary at the end of 2013, its administrative agency, the US Fish and Wildlife Service, was mired in controversy. At issue was a proposal to remove the gray wolf (Canis lupus) from the List of Endangered and Threatened Wildlife and add the Mexican gray wolf (Canis lupus baileyi).

Computer models help decode cells that sense light without seeing

Posted: 07 Feb 2014 10:30 AM PST

Researchers have found that the melanopsin pigment in the retina is potentially more sensitive to light than its more famous counterpart, rhodopsin, the pigment that allows for night vision. Scientists have leveraged supercomputers to study melanopsin, a retina pigment capable of sensing environmental light changes, informing the nervous system and synchronizing it with the day/night rhythm.

Bottom-up insight into crowd dynamics: Preparing for stampedes, mass evacuations

Posted: 07 Feb 2014 08:41 AM PST

Stampedes unfortunately occur on too regular a basis. Previously, physicists developed numerous models of crowd evacuation dynamics. Now, a new study outlines a procedure for quantitatively comparing different crowd models, which also helps to compare these models with real-world data. In a new paper, researchers have demonstrated that these crowd evacuation dynamics models are a viable decision-making tool in safety preparation and planning concerning real-world human crowds.

Ranking disease-causal mutations within whole genome sequences

Posted: 07 Feb 2014 08:41 AM PST

Researchers have developed a new method for organizing and prioritizing genetic data. The Combined Annotation–Dependent Depletion method will assist scientists in their search for disease-causing mutation events in human genomes.

Protein to repair damaged brain tissue in MS identified

Posted: 07 Feb 2014 08:41 AM PST

Researchers have found a "potentially novel therapeutic target" to reduce the rate of deterioration and to promote growth of brain cells damaged by multiple sclerosis. Current therapies can be effective in patients with relapsing multiple sclerosis but have little impact in promoting tissue growth.

New plant species a microcosm of biodiversity

Posted: 07 Feb 2014 08:41 AM PST

Biologists working in the Andes mountains of Ecuador have described a new plant species, a wild relative of black pepper, that is the sole home of an estimated 40-50 insect species, most of which are entirely dependent on this plant species for survival. This discovery is part of a larger project which focuses on the influence of plant-produced chemical compounds on biodiversity.

Beta blockers and perioperative care: EHJ editorial addresses controversy

Posted: 07 Feb 2014 07:26 AM PST

Whether beta blockers in perioperative care are protective, safe or harmful continues to be a subject of debate. The new ESC Guidelines will try to clarify some of the controversial issues. In the meantime, the current position is that "the initiation of beta blockers in patients who will undergo non-cardiac surgery should not be considered routine, but should be considered carefully by each patient's treating physician on a case-by-case basis."

Majority of Americans have their heart health facts wrong

Posted: 07 Feb 2014 07:23 AM PST

Despite the fact that heart disease is the leading cause of death for both men and women in the U.S., about three-quarters (74 percent) of Americans do not fear dying from it, according to a recent survey.

Gender influences symptoms of genetic disorder NF1

Posted: 07 Feb 2014 06:40 AM PST

Researchers have identified a patient's gender as a clear and simple guidepost to help health-care providers anticipate some of the complex effects of NF1, a genetic disorder.

Finding could explain age-related decline in motor function

Posted: 07 Feb 2014 06:40 AM PST

A team of researchers has found a clue as to why muscles weaken with age. The team observed a change in homeostatic set points in neuromuscular junction synapses of aged fruit flies.

Avian flu variant stalks Egypt

Posted: 07 Feb 2014 06:40 AM PST

A new study tracks the spread of an H5N1 variant in Egypt -- a country recently identified as a major epicenter for the virus. In results researchers track the spread of H5N1 cases using a technique known as phylogeography.

Social media, self-esteem and suicide: Nations with more corruption demonstrate more social media, less suicide

Posted: 07 Feb 2014 06:40 AM PST

In nations where corruption is rife, it seems that citizens these days find an escape from the everyday problems that trickle down to their lives by using online social media more than those elsewhere. Research also suggests that these two factors -- more corruption, more social networking -- also correlate with lower suicide rates.

Efficiently harnessing low frequency vibrations as infinite power source for miniature electronic devices

Posted: 07 Feb 2014 06:40 AM PST

Researchers have conceptualized a novel strategy to efficiently harness low frequency vibrations as infinite power source for miniature electronic devices.

Shadowing in Sensor Images: NASA study points to 'infrared-herring' in apparent Amazon green-up

Posted: 07 Feb 2014 05:39 AM PST

A new NASA study shows that the appearance of canopy greening is not caused by a biophysical change in Amazon forests, but instead by a combination of shadowing within the canopy and the way that satellite sensors observe the Amazon during the dry season.

Cholesterol plays a critical role in hantavirus infection

Posted: 07 Feb 2014 05:39 AM PST

Viruses mutate fast, which means they can quickly become resistant to anti-viral drugs. But viruses also depend on proteins and nutrients provided by their hosts, and therefore one strategy to identify new anti-viral drugs is to identify and target such host-cell components. Proteins involved in the regulation of cholesterol are essential for hantavirus entry into human host cells, new research shows.

'Steak-knife' teeth reveal ecology of oldest land predators

Posted: 07 Feb 2014 05:39 AM PST

The first top predators to walk on land were not afraid to bite off more than they could chew, a study has found. Researchers suggest that Dimetrodon, a carnivore that walked on land between 298 million and 272 million years ago, was the first terrestrial vertebrate to develop serrated ziphodont teeth.

Opening 'the X-files' helped researchers to understand why women and men differ in height

Posted: 07 Feb 2014 05:38 AM PST

Given its unique nature, the X chromosome has often been neglected when performing large-scale genetic studies. Because women have two copies of this chromosome and men only one, identifying genetic associations with X chromosomal genes can be particularly valuable in helping us to understand why some characteristics differ between sexes. Researchers have now identified novel X-chromosomal genetic variants that influence human height.

Fish biomass in the ocean may be 10 times higher than estimated: Stock of mesopelagic fish changes from 1,000 to 10,000 million tons

Posted: 07 Feb 2014 05:38 AM PST

With a stock estimated at 1,000 million tons so far, mesopelagic fish dominate the total biomass of fish in the ocean. However, scientists have found that their abundance could be at least 10 times higher. The results are based on the acoustic observations conducted during the circumnavigation of the Malaspina Expedition.

Click chemistry could provide total chemical DNA synthesis, study shows

Posted: 07 Feb 2014 05:38 AM PST

An interdisciplinary study has shown for the first time that 'click chemistry' can be used to assemble DNA that is functional in human cells, which paves the way for a purely chemical method for gene synthesis. Human cells can still read through strands of DNA correctly despite being stitched together using a linker not found in nature.

Large thermoelectric power from a combination of magnets and superconductors

Posted: 07 Feb 2014 05:37 AM PST

Thermoelectric devices can cool materials by passing currents, or convert temperature differences into electric power. However, especially metallic structures have a very poor thermoelectric performance, and therefore most thermoelectrics are made of semiconductors. Now researchers have shown how a proper combination of magnetic metals and superconductors could allow reaching very strong thermoelectric conversion efficiency.

Dating refined for Atapuerca site where Homo antecessor appeared

Posted: 07 Feb 2014 05:37 AM PST

One of the issues of the Atapuerca sites that generates the most scientific debate is the dating of the strata where the fossils are found. A study has clarified that the sediment of Gran Dolina, where the first remains of Homo antecessor were discovered in 1994, is 900,000 years old. The findings at the Lower Palaeolithic cave site of Gran Dolina, in the Sierra de Atapuerca mountain range (Burgos), have led to major advancements in our knowledge of human evolution and occupation of Eurasia.

Protein structure: Peering into the transit pore

Posted: 07 Feb 2014 05:37 AM PST

The lipid-rich membranes of cells are largely impermeable to proteins, but evolution has provided a way through -- in the form of transmembrane tunnels. A new study shows in unmatched detail what happens as proteins pass through such a pore.

Synthesized sponge chemical shows promise for cancer

Posted: 07 Feb 2014 05:37 AM PST

A promising compound for cancer treatment has been synthesized in a laboratory by a PhD student.

First stroke guidelines for women created

Posted: 07 Feb 2014 05:36 AM PST

Despite strokes being on the decline in the U.S., more women are dying from them than are men. Now medical scientists have released guidance on prevention specifically for women.

Toxin in seafood causes kidney damage in mice at levels considered safe for consumption

Posted: 07 Feb 2014 05:36 AM PST

Domoic acid accumulates in seafood and is toxic to the brain. Research indicates that the toxin damages kidneys at concentrations that are 100 times lower than what causes neurological effects.

Substance in photosynthesis was in play in ancient, methane-producing microbes

Posted: 07 Feb 2014 05:36 AM PST

A process that turns on photosynthesis in plants likely developed on Earth in ancient microbes 2.5 billion years ago, long before oxygen became available, according to new research.

Prickly protein helps stop staph bacteria

Posted: 06 Feb 2014 01:45 PM PST

A genetic mechanism that controls the production of a large spike-like protein on the surface of Staphylococcus aureus (staph) bacteria alters the ability of the bacteria to form clumps and to cause disease, according to a new study.

United States lead in science and technology shrinking

Posted: 06 Feb 2014 01:45 PM PST

The United States' predominance in science and technology eroded further during the last decade, as several Asian nations -- particularly China and South Korea -- rapidly increased their innovation capacities.

Nanoparticle pinpoints blood vessel plaques

Posted: 06 Feb 2014 01:45 PM PST

A team of researchers has developed a multifunctional nanoparticle that enables magnetic resonance imaging to pinpoint blood vessel plaques caused by atherosclerosis. The technology is a step toward creating a non-invasive method of identifying plaques vulnerable to rupture -- the cause of heart attack and stroke -- in time for treatment.

Brain: Loose coupling between calcium channels and sensors

Posted: 06 Feb 2014 01:45 PM PST

Neuroscientists have uncovered the existence of loose coupling between calcium channels and release sensors of exocytosis at a mature central synapse in the rodent brain. The researchers show that loose coupling provides a framework for presynaptic plasticity, a hallmark of synaptic signaling in hippocampal microcircuits.

Scholars offer scientific solution to 'persistent bias' in academia

Posted: 06 Feb 2014 01:45 PM PST

To address what they call persistent gender, racial, and ethnic bias in academia, scholars have recommended specific, rigorous interventions that lead to positive outcomes.

Regular aspirin use may reduce ovarian cancer risk: Study

Posted: 06 Feb 2014 01:44 PM PST

Women who take aspirin daily may reduce their risk of ovarian cancer by 20 percent, according to a study. However, further research is needed before clinical recommendations can be made.

Toxin from brain cells triggers neuron loss in human ALS model

Posted: 06 Feb 2014 12:52 PM PST

In most cases of amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, a toxin released by cells that normally nurture neurons in the brain and spinal cord can trigger loss of the nerve cells affected in the disease, researchers report.

Best weather forecasting models evaluated: Which one best predicted September 2013 Colorado floods?

Posted: 06 Feb 2014 12:52 PM PST

Researchers recently tested the ability of the world's most advanced weather forecasting models to predict the Sept. 9-16, 2013 extreme rainfall that caused severe flooding in Boulder, Colo.

What falling in love does to your heart and brain

Posted: 06 Feb 2014 12:52 PM PST

Getting struck by Cupid's arrow may very well take your breath away and make your heart go pitter-patter this Valentine's Day, reports sexual wellness specialists.

Source of chlamydia reinfections may be GI tract

Posted: 06 Feb 2014 11:21 AM PST

The current standard of care treatment for chlamydia sometimes fails to eradicate the disease, according to a review, and the culprit may be in the gut.

Excrement collected worldwide shows co-evolution of herbivores, their gut microbes

Posted: 06 Feb 2014 11:20 AM PST

An extensive study on excrement and rumen fluids in plant-eating mammals from all over the whole world shows that the ciliates in their guts have evolved in parallel with them. This is the result of a five-year research project performed by evolution biologists, microbiologists and computer scientists.

Fitness study pairs dogs with seniors

Posted: 06 Feb 2014 11:18 AM PST

Researchers have designed an exercise study to see if exercising with dogs yields better health outcomes.

Immune system 'overdrive' in pregnant women puts male offspring at special risk for adult brain disorders, mouse study suggests

Posted: 06 Feb 2014 11:18 AM PST

Researchers report that fetal mice — especially males — show signs of brain damage that lasts into their adulthood when they are exposed in the womb to a maternal immune system kicked into high gear by a serious infection or other malady. The findings suggest that some neurologic diseases in humans could be similarly rooted in prenatal exposure to inflammatory immune responses.

Decoding dengue, West Nile: Steps taken toward control of growing public health problems

Posted: 06 Feb 2014 11:18 AM PST

Dengue fever and West Nile fever are mosquito-borne diseases that affect hundreds of millions of people worldwide each year, but there is no vaccine against either of the related viruses.

The ultimate decoy: Protein helps bacteria misdirect immune system

Posted: 06 Feb 2014 11:18 AM PST

Scientists have discovered an unusual bacterial protein that attaches to virtually any antibody and prevents it from binding to its target.

Scientists use 'voting' and 'penalties' to overcome errors in quantum optimization

Posted: 06 Feb 2014 10:39 AM PST

Seeking a solution to decoherence -- the "noise" that prevents quantum processors from functioning properly -- scientists have developed a strategy of linking quantum bits together into voting blocks, a strategy that significantly boosts their accuracy. In a new study, the team found that their method results in at least a five-fold increase in the probability of reaching the correct answer when the processor solves the largest problems tested by the researcher, involving hundreds of qubits.

New investigational drug holds promise for combatting deadly mucormycosis infections

Posted: 06 Feb 2014 10:38 AM PST

With very few treatment options available to fight deadly mucormycosis infections, a new study holds hope for adding to the arsenal of therapies physicians have to combat an increasingly common infection afflicting people with weakened immune systems.

Brain asymmetry improves processing of sensory information, study shows

Posted: 06 Feb 2014 10:36 AM PST

Fish that have symmetric brains show defects in processing information about sights and smells, according to the results of a new study into how asymmetry in the brain affects processing of sensory information.

New disease gene discovery sheds light on cause of bone marrow failure

Posted: 06 Feb 2014 10:36 AM PST

New research has identified a novel genetic defect among patients with bone marrow failure, which could reveal its underlying cause.

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