jueves, 19 de junio de 2014

ScienceDaily: Top News

ScienceDaily: Top News


Evolution depends on rare chance events, 'molecular time travel' experiments show

Posted: 18 Jun 2014 07:05 PM PDT

Historians can only speculate on what might have been, but a team of evolutionary biologists studying ancient proteins has turned speculation into experiment. They resurrected an ancient ancestor of an important human protein as it existed hundreds of millions of years ago and then used biochemical methods to generate and characterize a huge number of alternative histories that could have ensued from that ancient starting point.

Quest for education creating graying ghost towns at top of the world

Posted: 18 Jun 2014 03:46 PM PDT

Ethnic Tibetan communities in Nepal's highlands are rapidly shrinking as more parents send their children away for a better education and modern careers, a trend that threatens to create a region of graying ghost towns at the top of the world, according to a new study.

New manufacturing methods for 'soft' machines, robots

Posted: 18 Jun 2014 03:46 PM PDT

Researchers have developed a technique that might be used to produce 'soft machines' made of elastic materials and liquid metals for potential applications in robotics, medical devices and consumer electronics. Such an elastic technology could make possible robots that have sensory skin and stretchable garments that people might wear to interact with computers or for therapeutic purposes.

Fish-eating spiders discovered in all parts of the world

Posted: 18 Jun 2014 03:46 PM PDT

Spiders are traditionally viewed as predators of insects. Zoologists from Switzerland and Australia have now published a study that shows: spiders all over the world also prey on fish.

Making smartphones smarter with see-through sensors: Pack more apps into new real estate, the display glass itself

Posted: 18 Jun 2014 01:51 PM PDT

Researchers have developed a new laser-writing technique that embeds smartphone display glass with layer-upon-layer of see-through sensors -- enabling applications like temperature sensors and biomedical monitors to be manufactured directly into the display. The work is the first laser-based light-guided system that is efficient enough for commercial use.

Crucial security problem in Google Play: Thousands of secret keys found in android apps

Posted: 18 Jun 2014 01:39 PM PDT

Researchers have discovered a crucial security problem in Google Play, the official Android app store. The study is the first to make a large-scale measurement of the huge marketplace, using PlayDrone, a tool they developed to circumvent Google security to successfully download Google Play apps and recover their sources.

Counterterrorism, ethics, and global health

Posted: 18 Jun 2014 12:38 PM PDT

The surge in murders of polio vaccination workers in Pakistan has made headlines this year, but little attention has been devoted to the ethical issues surrounding the global health impact of current counterterrorism policy and practice. A new essay reviews the range of harms to population health traceable to counterterrorism operations.

Placental marker of prenatal stress linked to brain mitochondrial dysfunction

Posted: 18 Jun 2014 11:26 AM PDT

An enzyme found in the placenta is likely playing an important role in translating stress experienced by a mother early in pregnancy into a reprogramming of her developing baby's brain, research suggests. "People think that the placenta only serves to promote blood flow between a mom and her baby, but that's really not all it's doing," the lead investigator said. "It's a very dynamic endocrine tissue and it's sex-specific, and we've shown that tampering with it can dramatically affect a baby's developing brain."

New blood test identifies heart-transplant rejection earlier than biopsy can

Posted: 18 Jun 2014 11:26 AM PDT

A noninvasive way to detect heart-transplant rejection weeks or months earlier than previously possible has been devised by researchers. The test, which relies on the detection of increasing amounts of the donor's DNA in the blood of the recipient, does not require the removal of any heart tissue.

Maybe birds can have it all: Dazzling colors and pretty songs

Posted: 18 Jun 2014 11:26 AM PDT

A study of one of the world's largest and most colorful bird families has dispelled a long-held notion, first proposed by Charles Darwin, that animals are limited in their options to evolve showiness. "Animals have limited resources, and they have to spend those in order to develop showy plumage or precision singing that help them attract mates and defend territories," said the paper's lead author. "So it seems to make sense that you can't have both. But our study took a more detailed look and suggests that actually, some species can."

False negative results found in prognostic testing for breast cancer

Posted: 18 Jun 2014 11:26 AM PDT

Researchers retested tumor samples from a large group of women and found that 22 out of 530 women had their tumor type incorrectly classified, which precluded them from effective treatment options. The repercussions of incorrectly identifying a cancer's subtype are considerable. "While it is comforting that only four percent of these women were misclassified initially, this is an enormous issue for those who fall into this group," said one researcher.

Breathalyzer test may detect deadliest cancer

Posted: 18 Jun 2014 11:00 AM PDT

Lung cancer causes more deaths in the US than the next three most common cancers combined. Now a new breathalyzer test, embedded with a 'NaNose' nanotech chip to literally 'sniff out' cancer tumors, has been developed by a team of international researchers. It may turn the tide by both accurately detecting lung cancer and identifying its stage of progression.

Familiar yet strange: Water's 'split personality' revealed by computer model

Posted: 18 Jun 2014 11:00 AM PDT

Using computer models, researchers found that as water freezes it takes on a sort of split personality wherein, at very cold temperatures and above a certain pressure, it may spontaneously split into two liquid forms. Finding this dual nature could lead to a better understanding of how water behaves in high-altitude clouds, which could improve the predictive ability of current weather and climate models.

Genetic code for diabetes in Greenland broken by scientists

Posted: 18 Jun 2014 11:00 AM PDT

New ground-breaking genetics research explains the high incidence of type 2 diabetes in the Greenlandic population, based on blood samples from 5,000 people or approximately 10% of the population. "Several epidemiological studies have looked at the health implications of the transition from life as sealers and hunters in small isolated communities to a modern lifestyle with appreciable dietary changes. Perhaps the gene variant which has been identified can be interpreted as a sign of natural selection as the traditional Greenlandic diet consisted primarily of protein and fat from sea animals," one researcher said.

Achilles' heel in antibiotic-resistant bacteria discovered

Posted: 18 Jun 2014 11:00 AM PDT

A breakthrough in the race to solve antibiotic resistance has been made by scientists. New research reveals an Achilles' heel in the defensive barrier that surrounds drug-resistant bacterial cells. The findings pave the way for a new wave of drugs that kill superbugs by bringing down their defensive walls rather than attacking the bacteria itself. It means that in future, bacteria may not develop drug-resistance at all.

Scientists take first dip into water's mysterious 'no-man's land'

Posted: 18 Jun 2014 11:00 AM PDT

Scientists have made the first structural observations of liquid water at temperatures down to minus 51 degrees Fahrenheit, within an elusive 'no-man's land' where water's strange properties are super-amplified.

How brain 'reboots' itself to consciousness after anesthesia

Posted: 18 Jun 2014 10:58 AM PDT

One of the great mysteries of anesthesia is how patients can be temporarily rendered completely unresponsive during surgery and then wake up again, with their memories and skills intact. "Recovery from anesthesia is not simply the result of the anesthetic 'wearing off,' but also of the brain finding its way back through a maze of possible activity states to those that allow conscious experience," one researcher said. "Put simply, the brain reboots itself."

Molecular 'Yin-Yang' of Blood Vessel Growth revealed

Posted: 18 Jun 2014 10:58 AM PDT

A crucial process that regulates development of blood vessels has been discovered by scientists. SerRS (seryl tRNA synthetase) belongs to a family of enzymes that have fundamental, evolutionarily ancient roles in the protein-making machinery of cells. But researchers have been finding in recent years, some of these protein-maker enzymes seem to have evolved extra functions. The finding may lead to treatments for disorders involving abnormal blood vessel growth, including diabetic retinopathy and cancer.

When it comes to numbers, culture counts

Posted: 18 Jun 2014 10:20 AM PDT

A new study finds that in a Bolivian rainforest society, children learn to count just like in the US, but on a delayed timetable.

Self-repairing mechanism can help to preserve brain function in neurodegenerative diseases

Posted: 18 Jun 2014 10:20 AM PDT

Neurogenesis, the self-repairing mechanism of the adult brain, can help to preserve brain function in neurodegenerative diseases such as Alzheimer's, Prion or Parkinson's, research shows. The brain has some self-repairing potential that accounts for the renewal of certain neuronal populations living in the dentate gyrus, a simple cortical region that is part of the larger functional brain system controlling learning and memory, the hippocampus. This process is known as neurogenesis.

Modeling how neurons work together may help design robotic limbs

Posted: 18 Jun 2014 10:20 AM PDT

A highly accurate model of how neurons behave when performing complex movements could aid in the design of robotic limbs which behave more realistically. While an action such as reaching for a cup of coffee may seem straightforward, the millions of neurons in the brain's motor cortex must work together to prepare and execute the movement before the coffee ever reaches our lips. These signals are transmitted across synapses -- the junctions between neurons.

Groundbreaking model explains how the brain learns to ignore familiar stimuli

Posted: 18 Jun 2014 10:19 AM PDT

A neuroscientist has proposed a new, ground-breaking explanation for the process of 'habituation,' which allows the brain to filter out significant environmental stimuli from the insignificant, and which is altered in Austim Spectrum Disorders.

Blocking brain's 'internal marijuana' may trigger early Alzheimer's deficits, study shows

Posted: 18 Jun 2014 10:19 AM PDT

A new study has implicated the blocking of endocannabinoids -- signaling substances that are the brain's internal versions of the psychoactive chemicals in marijuana and hashish -- in the early pathology of Alzheimer's disease.

Evolutionary biology: Why cattle, pigs only have two toes

Posted: 18 Jun 2014 10:19 AM PDT

During evolutionary diversification of vertebrate limbs, the number of toes in even-toed ungulates such as cattle and pigs was reduced and transformed into paired hooves. Scientists have identified a gene regulatory switch that was key to evolutionary adaption of limbs in ungulates. The study provides insights into the molecular history of evolution.

How genetic mutation causes early brain damage

Posted: 18 Jun 2014 10:19 AM PDT

Scientists have shed light on how a specific kind of genetic mutation can cause damage during early brain development that results in lifelong learning and behavioral disabilities. The study focuses on the role of a gene known as Syngap1. In humans, mutations in Syngap1 are known to cause devastating forms of intellectual disability and epilepsy.

Nature's chem lab: How microorganisms manufacture drugs

Posted: 18 Jun 2014 10:19 AM PDT

The first three-dimensional snapshots of the "assembly line" within microorganisms that naturally produces antibiotics and other drugs have been captured by researchers. Understanding the complete structure and movement within the molecular factory gives investigators a solid blueprint for redesigning the microbial assembly line to produce novel drugs of high medicinal value.

Molecule vital for creating water exists in dying sun-like stars

Posted: 18 Jun 2014 09:38 AM PDT

Using ESA's Herschel space observatory, astronomers have discovered that a molecule vital for creating water exists in the burning embers of dying Sun-like stars.

Titan flybys test the talents of NASA's Cassini team

Posted: 18 Jun 2014 09:36 AM PDT

As NASA's Cassini spacecraft zooms toward Saturn's smoggy moon Titan for a targeted flyby on June 18, mission scientists are excitedly hoping to repeat a scientific tour de force that will provide valuable new insights into the nature of the moon's surface and atmosphere.

Nanoparticles from dietary supplement drinks likely to reach environment: Potentially harmful substances

Posted: 18 Jun 2014 09:23 AM PDT

Nanoparticles are becoming ubiquitous in food packaging, personal care products and are even being added to food directly. But the health and environmental effects of these tiny additives have remained largely unknown. A new study now suggests that nanomaterials in food and drinks could interfere with digestive cells and lead to the release of the potentially harmful substances to the environment.

New method to identify inks could help preserve historical documents

Posted: 18 Jun 2014 09:22 AM PDT

The inks on historical documents can hold many secrets. Its ingredients can help trace trade routes and help understand a work's historical significance. And knowing how the ink breaks down can help cultural heritage scientists preserve valuable treasures. Researchers report the development of a new, non-destructive method that can identify many types of inks on various papers and other surfaces.

Ban on pavement sealant lowered levels of potentially harmful compounds in lake

Posted: 18 Jun 2014 09:22 AM PDT

In 2006, Austin, Texas, became the first city in the country to ban a commonly used pavement sealant over concerns that it was a major source of cancer-causing compounds in the environment. Eight years later, the city's action seems to have made a big dent in the targeted compounds' levels -- researchers now report that the concentrations have dropped significantly.

Collecting light with artificial moth eyes: Producing hydrogen with sunlight

Posted: 18 Jun 2014 09:21 AM PDT

All over the world researchers are investigating solar cells which imitate plant photosynthesis, using sunlight and water to create synthetic fuels such as hydrogen. Researchers have developed such a photoelectrochemical cell, recreating a moth's eye to drastically increase its light collecting efficiency. The cell is made of cheap raw materials – iron and tungsten oxide.

Cost-effectiveness of smoking cessation counseling during hospitalization shown in study

Posted: 18 Jun 2014 08:18 AM PDT

The cost-effectiveness of the Ottawa Model for Smoking Cessation, an intervention that includes in-hospital counseling, pharmacotherapy and post-hospital follow-up, has been demonstrated compared to usual care among smokers hospitalized with acute myocardial infarction, unstable angina, heart failure, and chronic obstructive pulmonary disease.

Trap-jaw ants spreading in southeastern United States

Posted: 18 Jun 2014 08:18 AM PDT

Trap-jaw ant species are active hunters with venomous stings and jaws powerful enough to fling themselves through the air. According to new research, they are also spreading into new territory in the southeastern United States. A new paper is designed to help scientists identify which species of trap-jaw ants they're dealing with. While the paper draws on previously published research, it also includes new findings.

New horned dinosaur reveals unique wing-shaped headgear

Posted: 18 Jun 2014 08:18 AM PDT

A new species of horned dinosaur has been named Mercuriceratops gemini: Mercuriceratops (Mercuri + ceratops) means "Mercury horned-face," referring to the wing-like ornamentation on its head that resembles the wings on the helmet of the Roman god, Mercury. The name "gemini" refers to the almost identical twin specimens found in north central Montana and the Dinosaur Provincial Park, in Alberta, Canada. The dinosaur had a parrot-like beak and probably had two long brow horns above its eyes. It was a plant-eating dinosaur.

Suicidal behaviour not increased by ADHD drugs, research concludes

Posted: 18 Jun 2014 08:17 AM PDT

Drug therapy for ADHD does not entail an increased risk of suicide attempts or suicide, as was previously feared, a new register-based study from Sweden shows. Earlier research has indicated that ADHD drug treatment would increase the occurrence of suicidal thoughts. One strong point of the study now being published is that all the individuals were compared to themselves, as this allowed the researchers to take into account the differences between those taking the drugs and those who do not.

Identifying opposite patterns of climate change: Hydrologic seesaw over the past 550,000 years

Posted: 18 Jun 2014 07:06 AM PDT

New research overturns common ideas about the different types of climate changes between the middle latitude areas of the Northern and Southern Hemispheres.

A call to better protect Antarctica: Human activity threatening continent

Posted: 18 Jun 2014 07:06 AM PDT

With visitor numbers surging, Antarctica's ice-free land needs better protection from human activities, leading environmental scientists say. The new study found that all 55 areas designated for protection lie close to sites of human activity. Antarctica has over 40,000 visitors a year, and more and more research facilities are being built in the continent's tiny ice-free area. Most of the Antarctic wildlife and plants live in the ice-free areas -- and this is also where people most visit.

Satellite data provides picture of underground water

Posted: 18 Jun 2014 07:06 AM PDT

Scientists demonstrate that satellite-collected data can accurately measure aquifer levels, a finding with potentially huge implications for management of precious global water sources.

Electrical switch during labor could be faulty in overweight women

Posted: 18 Jun 2014 07:06 AM PDT

Researchers have identified an electrical switch in the muscle of the uterus that plays a key role in the progression into labor. Crucially, the discovery shows that women who are overweight have a faulty switch. The finding may explain why overweight women have a higher likelihood of irregular contractions and are more likely to require a caesarean section than other women.

The noisy world of mud crabs: Predatory fish sounds can alter crab behavior

Posted: 18 Jun 2014 07:06 AM PDT

Marine crabs are capable of hearing, researchers show for the first time, and their auditory ability plays an important role in their response to fish predators. In a new paper, they show that sound plays at least as much of a role in mud crabs' reaction to fish behavior as other widely studied cues -- and possibly more.

Race a factor in mortality in heart attack patients on anti-clotting drug

Posted: 18 Jun 2014 07:06 AM PDT

The first genetic variations linked to race have been identified that begin to explain a higher risk of death among some African American and Caucasian patients taking the anti-clotting drug clopidogrel after a heart attack. In particular, the team found that two DNA variants common in African Americans were associated with an increased risk of both bleeding and death. In Caucasians, a different variant was linked to additional heart attacks and a higher risk of death.

Hippocampal activity during music listening exposes the memory-boosting power of music

Posted: 18 Jun 2014 07:05 AM PDT

For the first time the hippocampus —- a brain structure crucial for creating long-lasting memories —- has been observed to be active in response to recurring musical phrases while listening to music. Thus, the hippocampal involvement in long-term memory may be less specific than previously thought, indicating that short and long-term memory processes may depend on each other after all.

Horizontal levitation: The ultimate solution to particle separation

Posted: 18 Jun 2014 07:05 AM PDT

Separating particles from the liquid they are in can now be done with a new concept. Magnetic separators exploit the difference in magnetic properties between minerals, for example when separating magnetite from quartz. But this exercise becomes considerably more complex when the particles are not magnetic. In the wake of previous particle levitation experiments under high-power magnetic fields, a new study reveals that particles are deflected away from the magnet's round-shaped bore center in a horizontal direction.

New quantum mechanism to trigger the emission of tunable light at terahertz frequencies

Posted: 18 Jun 2014 07:05 AM PDT

Scientists have found that two-dimensional (2-D) nanostructures with asymmetric design enable a new quantum mechanism, triggering the emission of tunable light at terahertz frequencies-with unprecedented efficiency. The researchers found that quantum wells, 2-D nanostructures formed of several layers of semi-conductor alloys placed on top of each other like a sandwich, can enhance light emission in a technological challenging spectral range.

Punishment plays important role in forgiveness

Posted: 18 Jun 2014 07:05 AM PDT

It's easier for people to forgive someone for doing wrong against them if some form of punishment is involved, according to psychology researchers. "Justice and forgiveness are often considered to be opposites, but we've found that victims who punish their offender are more able to forgive and move on," one researcher says.

Exposure to TV violence related to irregular attention and brain structure

Posted: 18 Jun 2014 07:05 AM PDT

Young adult men who watched more violence on television showed indications of less mature brain development and poorer executive functioning, according to new results. Executive functioning abilities can be important for controlling impulsive behaviors, including aggression.

No evidence that soy food protects against endometrial cancer, study finds

Posted: 18 Jun 2014 04:20 AM PDT

No evidence of a protective association between soy food and endometrial cancer risk has been found, concludes a new study. Soy foods are an almost exclusive dietary source of isoflavones, a plant-derived estrogen. Some studies have highlighted their potential cancer protective properties, however, research looking at the link to endometrial cancer has been inconsistent.

Animals conceal sickness symptoms in certain social situations

Posted: 18 Jun 2014 04:19 AM PDT

Animals have the ability to conceal their sickness in certain social situations. According to a new review, when given the opportunity to mate or in the presence of their young, sick animals will behave as though they were healthy. The research has implications for our understanding of the spread of infectious diseases.

Spanish slug: Busting an invasion myth

Posted: 18 Jun 2014 04:19 AM PDT

Spanish slugs (Arion lusitanicus) are one of the most common slug species in Central Europe. The animals sometimes nicknamed "killer slugs" are known to do their fair share of damage in fields and gardens. The slug was thought to have originated in Southern Europe. However researchers have now found out that the prime example of an invasive species is originally from Central Europe and thus no "immigrant" after all.

Gender 'rebalancing' in China: An uncertain future

Posted: 18 Jun 2014 04:17 AM PDT

China is the most gender imbalanced country in the world, with an official sex ratio at birth (SRB) of 117.78 (boys for every one hundred girls) in 2011. Over the past two decades the rise in China's SRB has had a wide range of economic and social consequences. Researchers investigate the future impact of this rise using demographic and economic projections. Their results suggest that even if the Chinese government takes action to rebalance the sex ratio, the long-term picture is uncertain.

World’s first light technology to control proteins in living cells

Posted: 18 Jun 2014 04:17 AM PDT

The world's first technology to control specific protein functions in living cells by using lights has been developed, which may be useful in future cancer cell research. The research group has found that this technology allows scientists to inactivate critical biological phenomena, including cell migration and cell division, by using only lights, and without the assistance of chemical drug treatments or genetic modification.

Birds evolve 'signature' patterns to distinguish cuckoo eggs from their own

Posted: 18 Jun 2014 04:17 AM PDT

For some birds, recognizing their own eggs can be a matter of life or death. In a new study, scientists have shown that many birds affected by the parasitic Common Cuckoo -- which lays its lethal offspring in other birds' nests -- have evolved distinctive patterns on their eggs in order to distinguish them from those laid by a cuckoo cheat.

Vaccine 'reprograms' pancreatic cancers to respond to immunotherapy

Posted: 18 Jun 2014 04:15 AM PDT

A vaccine that triggered the growth of immune cell nodules within pancreatic tumors, essentially reprogramming these intractable cancers and potentially making them vulnerable to immune-based therapies, has developed and tested by researchers. The reprogramming is designed to make the tumors more vulnerable to other immune-modulating drugs that have been useful in fighting other cancers, researchers explain.

Brain imaging shows enhanced executive brain function in people with musical training

Posted: 17 Jun 2014 06:10 PM PDT

A controlled study using functional MRI brain imaging reveals a possible biological link between early musical training and improved executive functioning in both children and adults, report researchers. The study uses functional MRI of brain areas associated with executive function, adjusting for socioeconomic factors.

Shipping needs radical rethink warn climate experts

Posted: 17 Jun 2014 06:03 PM PDT

Avoiding dangerous levels of climate change requires a radical rethink of the shipping system, according to a new report. If global shipping is to make its fair contribution to avoiding the 2°C of warming associated with dangerous climate change, CO2 emissions need to be cut within the next decade and fall by at least 80% by 2050 compared to 1990 levels, say experts.

Human sweat can reduce anti-bacterial properties of brass objects in hospitals and schools

Posted: 17 Jun 2014 06:03 PM PDT

Researchers discover sweat can cause corrosion of protective qualities of door knobs and taps within an hour of contact. Sweaty hands can reduce the effectiveness of bacteria-fighting brass objects in hospitals and schools after just an hour of coming into contact with them.

Stress hormone linked to short-term memory loss as we age, animal study suggests

Posted: 17 Jun 2014 06:01 PM PDT

A new study reports a potential link between stress hormones and short-term memory loss in older adults. The study reveals that having high levels of cortisol—a natural hormone in our body whose levels surge when we are stressed—can lead to memory lapses as we age.

Limited motor skills in early infancy may be trait of autism

Posted: 17 Jun 2014 02:08 PM PDT

Researchers have announced findings that provide evidence for reduced grasping and fine motor activity among six-month-old infants with an increased familial risk for autism spectrum disorders.

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