Παρασκευή 21 Ιουνίου 2013

ScienceDaily: Latest Science News

ScienceDaily: Latest Science News


Men who can't produce sperm face increased cancer risk

Posted: 20 Jun 2013 06:40 PM PDT

Men who are diagnosed as azoospermic -- infertile because of an absence of sperm in their ejaculate -- are more prone to developing cancer than the general population, urologists have found. And a diagnosis of azoospermia before age 30 carries an eight-fold cancer risk, the study says.

Women's facial features can determine length of relationship

Posted: 20 Jun 2013 06:40 PM PDT

Men in relationships prefer women with more feminine faces for a fling.

Hong Kong skyscrapers appear to fall in real-world illusion

Posted: 20 Jun 2013 01:28 PM PDT

No matter how we jump, roll, sit, or lie down, our brain manages to maintain a visual representation of the world that stays upright relative to the pull of gravity. But a new study of rider experiences on the Hong Kong Peak Tram, a popular tourist attraction, shows that specific features of the environment can dominate our perception of verticality, making skyscrapers appear to fall.

Light and nanoprobes detect early signs of infection

Posted: 20 Jun 2013 01:28 PM PDT

Biomedical engineers and genome researchers have developed a proof-of-principle approach using light to detect infections before patients show symptoms.

Student engagement more complex, changeable than thought

Posted: 20 Jun 2013 01:28 PM PDT

A student who shows up on time for school and listens respectfully in class might appear fully engaged to outside observers, including teachers. But other measures of student engagement, including the student's emotional and cognitive involvement with the course material, may tell a different story -- one that could help teachers recognize students who are becoming less invested in their studies, according to a new study.

Factors that influence spinach contamination pre-harvest determined

Posted: 20 Jun 2013 01:28 PM PDT

Scientists have identified a variety of factors that influence the likelihood of E. coli contamination of spinach on farms prior to harvest.

How did a third radiation belt appear in the Earth's upper atmosphere?

Posted: 20 Jun 2013 01:28 PM PDT

How did a third radiation belt appear in the Earth's upper atmosphere, and then almost completely disappear?

Solar splashdown provide new insights into how young stars grow by sucking up nearby gas

Posted: 20 Jun 2013 01:28 PM PDT

On June 7, 2011, our sun erupted, blasting tons of hot plasma into space. Some of that plasma splashed back down onto the sun's surface, sparking bright flashes of ultraviolet light. This dramatic event may provide new insights into how young stars grow by sucking up nearby gas.

Sleep deprivation in teens linked to poor dietary choices

Posted: 20 Jun 2013 01:27 PM PDT

Well-rested teenagers tend to make more healthful food choices than their sleep-deprived peers, according to a new study. The finding may be key to understanding the link between sleep and obesity.

Study of insect bacteria reveals genetic secrets of symbiosis

Posted: 20 Jun 2013 11:29 AM PDT

Microbiologists recently delved deeper into the genes involved in the "tripartite nested mealybug symbiosis." The researchers discovered the already complex three-way symbiosis actually depends on genes from six different organisms -- three more than the number of species that currently exist in the symbiosis.

New method for achieving nonlinear optical effects: Method could be a step toward quantum computing

Posted: 20 Jun 2013 11:29 AM PDT

In a step forward for quantum computing, researchers have theorized a new method for making photons interact.

Study on fragile newborns challenges current practices

Posted: 20 Jun 2013 11:29 AM PDT

One of the largest clinical trials done in infants with congenital heart diseases shows that the increasingly common practice of using the drug clopidogrel (Plavix) to reduce shunt-related blood flow issues is not effective in the dose studied.

The Red Queen was right: Life must continually evolve to avoid extinction

Posted: 20 Jun 2013 11:29 AM PDT

Biologists quote Lewis Carroll when arguing that survival is a constant struggle to adapt and evolve. Is that true, or do groups die out because they experience a run of bad luck? Biologists tested these hypotheses using mammals that arose and died out (or are now dying out) in the past 66 million years, and found that it's not luck but failure to adapt to a deteriorating environment.

Uncovering quantum secret in photosynthesis

Posted: 20 Jun 2013 11:29 AM PDT

Scientists have observed the quantum character of light transport through the molecular machines at work in natural photosynthesis. By studying a single machine at a time, they found that this quantum transport is very persistent and robust regardless of environmental changes. These results could pave the way for the construction of solar energy devices with an efficiency surpassing anything we have seen to date.

Bigbrain: An ultra-high resolution 3-D roadmap of the human brain

Posted: 20 Jun 2013 11:29 AM PDT

A landmark three-dimensional digital reconstruction of a complete human brain, called the BigBrain, now for the first time shows the brain anatomy in microscopic detail -- at a spatial resolution of 20 microns, smaller than the size of one fine strand of hair -- exceeding that of existing reference brains presently in the public domain.

Cities are a new kind of complex system: Part social reactor, part network

Posted: 20 Jun 2013 11:29 AM PDT

Scientists have derived a series of mathematical formulas that describe how cities' properties vary in relation to their population size, and then posits a novel unified, quantitative framework for understanding how cities function and grow. The resulting theoretical framework predicts very closely dozens of statistical relationships observed in thousands of real cities around the world for which reliable data are available.

How a mutated protein outwits evolution and fuels leukemia

Posted: 20 Jun 2013 11:28 AM PDT

Scientists have discovered the survival secret to a genetic mutation that stokes leukemia cells, solving an evolutionary riddle and paving the way to a highly targeted therapy for leukemia. A new article describe how a mutated protein, called Fbxw7, behaves differently when expressed in cancer cells versus healthy cells.

Thirdhand smoke causes DNA damage

Posted: 20 Jun 2013 10:24 AM PDT

A new study has found for the first time that thirdhand smoke -- the noxious residue that clings to virtually all surfaces long after the secondhand smoke from a cigarette has cleared out -- causes significant genetic damage in human cells.

Changing ocean temperatures, circulation patterns affecting young Atlantic cod food supply

Posted: 20 Jun 2013 10:24 AM PDT

Changing ocean water temperatures and circulation patterns have profoundly affected key Northeast U.S. Continental Shelf zooplankton species in recent decades, and may be influencing the recovery of Atlantic cod and other fish stocks in the region. Researchers have found that zooplankton species critical for the survival of Atlantic cod larvae have declined in abundance in the same areas where Atlantic cod stocks have struggled to rebuild after an extended period of overfishing.

Particle accelerator that can fit on a tabletop opens new chapter for science research

Posted: 20 Jun 2013 10:24 AM PDT

The laser plasma accelerator has accelerated about half a billion electrons to 2 gigaelectronvolts over a distance of about 1 inch. It's a downsizing of a factor of approximately 10,000, and marks a major milestone in the advance toward the day when multi-gigaelectronvolt laser plasma accelerators are standard equipment in research laboratories around the world.

Total amount of exercise important, not frequency, research shows

Posted: 20 Jun 2013 10:24 AM PDT

Getting at least 150 minutes of exercise per week is paramount for health but choosing how to schedule the exercise is not.

Does your salad know what time it is? Managing vegetables' 'internal clocks' postharvest could have health benefits

Posted: 20 Jun 2013 10:23 AM PDT

Biologists have found there may be potential health benefits to storing fresh produce under day-night cycles of light. In a new study researchers used lighting to alter the circadian rhythms of cabbage, lettuce, spinach, zucchini, carrots, sweet potatoes and blueberries. The scientists showed how manipulation of circadian rhythms caused cabbage to produce more phytochemicals, including antioxidants.

The link between circadian rhythms and aging: Gene associated with longevity also regulates the body's circadian clock

Posted: 20 Jun 2013 10:23 AM PDT

Human sleeping and waking patterns are largely governed by an internal circadian clock that corresponds closely with the 24-hour cycle of light and darkness. This circadian clock also controls other body functions, such as metabolism and temperature regulation. A new study finds that a gene associated with longevity also regulates the body's circadian clock.

Two-week treatment found to prevent epilepsy in mice gives hope for drug development

Posted: 20 Jun 2013 10:23 AM PDT

Temporal lobe epilepsy is characterized by recurrent seizures throughout life and often behavioral abnormalities, with devastating impacts on patients and their families. Unfortunately, the condition is often not responsive to anticonvulsants. Now scientists report that targeting a particular signaling pathway in mice can prevent the development of temporal lobe epilepsy with two weeks of treatment, offering hope that researchers will be able to develop effective drugs to mitigate recurrent seizures and the development of epilepsy.

Flowers: Pistil leads pollen in life-and-death dance

Posted: 20 Jun 2013 10:23 AM PDT

Pollination, essential to much of life on earth, requires the explosive death of the male pollen tube in the female ovule. In new research, scientists describe the genetic and regulatory factors that compel the male's role in the process. Finding a way to tweak that performance could expand crop cross-breeding possibilities.

Hubble spots galaxies in close encounter: Colliding galaxy pair takes flight

Posted: 20 Jun 2013 10:22 AM PDT

The NASA/ESA Hubble Space Telescope has produced this vivid image of a pair of interacting galaxies known as Arp 142. When two galaxies stray too close to each other they begin to interact, causing spectacular changes in both objects. In some cases the two can merge — but in others, they are ripped apart.

Chlamydia promotes gene mutations

Posted: 20 Jun 2013 10:22 AM PDT

Chlamydia trachomatis is a human pathogen that is the leading cause of bacterial sexually transmitted disease worldwide with more than 90 million new cases of genital infections occurring each year. About 70 percent of women infected with Chlamydiaremain asymptomatic and these bacteria can establish chronic infections for months, or even years. Even when it causes no symptoms, Chlamydia can damage a woman's reproductive organs.

Herding cancer cells to their death

Posted: 20 Jun 2013 10:21 AM PDT

Scientists have developed a therapeutic strategy that manipulates a mechanism driving cellular heterogeneity to treat advanced melanoma.

Key player in the genesis of human intestinal immunity identified

Posted: 20 Jun 2013 10:21 AM PDT

Better treatments for people suffering from compromised intestinal immunity may emerge from a small-animal model of human intestinal immune development.

Key signaling pathway that makes young neurons connect

Posted: 20 Jun 2013 10:21 AM PDT

Neuroscientists have filled in a significant gap in the scientific understanding of how neurons mature, pointing to a better understanding of some developmental brain disorders.

Pluripotent stem cells made from pancreatic cancer cells are first human model of the cancer's progression

Posted: 20 Jun 2013 10:21 AM PDT

Pancreatic cancer carries a dismal prognosis. Researchers and clinicians don't have a non-invasive way to even detect early cells that portent later disease. Scientists have created a research cell line from a patient with advanced pancreatic cancer. This first-of-its-kind human-cell model of pancreatic cancer progression is the first example using induced pluripotent stem cells to model cancer progression directly from a solid tumor and to model pancreatic cancer from early to invasive stages.

Animal study shows promising path to prevent epilepsy

Posted: 20 Jun 2013 10:21 AM PDT

Researchers have identified a receptor in the nervous system that may be key to preventing epilepsy following a prolonged period of seizures. Their findings from studies in mice provide a molecular target for developing drugs to prevent the onset of epilepsy, not just manage the disease's symptoms.

Hospital reduces incidence of hospital-associated C. difficile by 70 percent

Posted: 20 Jun 2013 08:12 AM PDT

Rhode Island Hospital has reduced the incidence of hospital-associated Clostridium difficile (C. difficile) infections by 70 percent and reduced annual associated mortality in patients with hospital-associated C. difficile by 64 percent through successive implementation of five rigorous interventions. A major cause of morbidity and mortality in the US, C. difficile can cause life-threatening infections that occur most frequently in patients who have received antibiotic therapy.

'Forrest Gump' mice show too much of a good thing, can be bad

Posted: 20 Jun 2013 08:12 AM PDT

A line of genetically modified mice that scientists call "Forrest Gump" because, like the movie character, they can run far but they aren't smart, is furthering the understanding of a key neurotransmitter called acetylcholine. Scientists say the mice show what happens when too much of this neurotransmitter becomes available in the brain.

Too green to be true? Highly effective method for converting CO2 into methanol

Posted: 20 Jun 2013 08:12 AM PDT

Researchers have developed a highly effective method for converting CO2 into methanol, which can be used as a low-emissions fuel for vehicles.

Making a beeline for the nectar: How patterns on flowers help bees spot their first nectar-rich flower

Posted: 20 Jun 2013 08:12 AM PDT

Bumblebees searching for nectar go for signposts on flowers rather than the bull's eye. A new study shows that the markings at the center of a flower are not as important as the markings that will direct the bees to the center.

Autophaser improves sample analysis in areas such as cancer, Alzheimer's and oil spills

Posted: 20 Jun 2013 08:12 AM PDT

A new software package allows researchers to vastly improve the performance of one of the key tools used to analyse medical and environmental samples.

Potential drug compound attacks Parkinson's on two fronts

Posted: 20 Jun 2013 08:11 AM PDT

Scientists have found a compound that could counter Parkinson's disease in two ways at once. Scientists now describe a "dual inhibitor" that attacks a pair of proteins closely associated with development of Parkinson's disease.

App to protect private data on iOS devices finds almost half of other apps access private data

Posted: 20 Jun 2013 07:12 AM PDT

Almost half of the mobile apps running on Apple's iOS operating system access the unique identifier of the devices where they're downloaded, computer scientists have found. In addition, more than 13 percent access the devices' location and more than 6 percent the address book. The researchers developed a new app that detects what data the other apps running on an iOS device are trying to access.

54% of pregnant women use insecticides that are harmful to the fetus, Spanish study shows

Posted: 20 Jun 2013 07:08 AM PDT

Pregnancy and infancy are the periods of greatest vulnerability to the use of household insecticides. This is one of the findings of the first study of its kind to be carried out in Spain, which concludes that more than half of expectant mothers routinely use these chemical compounds. Spanish researchers have described the use of domestic pesticides during pregnancy and the first year of life in nearly 2,500 women and children.

Lab reproduction of a marine compound with antibiotic properties

Posted: 20 Jun 2013 07:08 AM PDT

Chemists have synthesized baringolin, a substance isolated from the depths of the sea. At very small doses this compound inhibits the growth of antibiotic-resistant bacteria.

Archaeologists make significant find of early 1800s artifacts on university campus

Posted: 20 Jun 2013 07:07 AM PDT

Archaeologists have uncovered a significant site on a university campus that has yielded thousands of artifacts from the early 1800s and is offering a glimpse into the lives of students of the era.

Virus combination effective against deadly brain tumor

Posted: 20 Jun 2013 07:07 AM PDT

A combination of the myxoma virus and the immune suppressant rapamycin can kill glioblastoma multiforme, the most common and deadliest malignant brain tumor, according to new research. Researchers says the combination has been shown to infect and kill both brain cancer stem cells and differentiated compartments of glioblastoma multiforme.

Snail trail reveals ancient human migration

Posted: 20 Jun 2013 05:46 AM PDT

Geneticists have used snails to uncover evidence of an ancient human migration from the Pyrenean region of France to Ireland.

Transistor made from just one molecular monolayer made to work on computer chip

Posted: 20 Jun 2013 04:15 AM PDT

Electronic components built from single molecules using chemical synthesis could pave the way for smaller, faster and more green and sustainable electronic devices. Now for the first time, a transistor made from just one molecular monolayer has been made to work where it really counts. On a computer chip.

Protected areas provide African birds with stepping stones to survival

Posted: 20 Jun 2013 04:15 AM PDT

The protected area network in Tanzania is playing a vital role in the survival of savannah bird species as they move west in response to climate and environmental changes, according to new research.

Realistic 3-d tumor created through tissue engineering using silk scaffolds

Posted: 20 Jun 2013 04:14 AM PDT

Medical researchers have developed a highly realistic three-dimensional (3-D) tumor model. As it replicates the conditions in the body, it is able to track the effectiveness and progress of drug therapy. Their model has the potential to be a more effective method for studying tumors than in-vitro and even in-vivo methods.

New regulator discovered for information transfer in the brain

Posted: 20 Jun 2013 04:14 AM PDT

The protein mSYD1 has a key function in transmitting information between neurons.

Dusty surprise around giant black hole

Posted: 20 Jun 2013 04:14 AM PDT

ESO's Very Large Telescope Interferometer has gathered the most detailed observations ever of the dust around the huge black hole at the centre of an active galaxy. Rather than finding all of the glowing dust in a doughnut-shaped torus around the black hole, as expected, the astronomers find that much of it is located above and below the torus. These observations show that dust is being pushed away from the black hole as a cool wind — a surprising finding that challenges current theories and tells us how supermassive black holes evolve and interact with their surroundings.

Flu shot likely prevented 13 million illnesses, 110,000 hospitalizations from 2005-2011

Posted: 19 Jun 2013 04:51 PM PDT

Approximately 13 million illnesses and over 110,00 hospitalizations may have been averted by the flu vaccine over the last 6 years in the US, according to new calculations.

Snail genetic tracks reveal ancient human migration: Mesolithic humans may have carried snail species from France to Ireland

Posted: 19 Jun 2013 04:51 PM PDT

Some snails in Ireland and the Pyrenees are genetically almost identical, perhaps because they were carried across the Atlantic during an 8000-year-old human migration. The snail genetics tie in with studies of human genetics and the colonization of Ireland, according to new research.

One in four stroke patients suffer PTSD

Posted: 19 Jun 2013 04:49 PM PDT

One in four people who survive a stroke or transient ischemic attack (TIA) suffer from symptoms of PTSD within the 1st year post-event, and one in nine experience chronic PTSD more than a year later. The data suggest that each year nearly 300,000 stroke/TIA survivors will develop PTSD symptoms as a result of their health scare.

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