jueves, 21 de agosto de 2014

ScienceDaily: Top News

ScienceDaily: Top News


Seals and sea lions likely spread tuberculosis to humans

Posted: 20 Aug 2014 11:00 AM PDT

Scientists who study tuberculosis have long debated its origins. New research shows that tuberculosis likely spread from humans in Africa to seals and sea lions that brought the disease to South America and transmitted it to Native people there before Europeans landed on the continent.

Life can persist in cold, dark world: Life under Antarctic ice explored

Posted: 20 Aug 2014 11:00 AM PDT

The first breakthrough article to come out of a massive U.S. expedition to one of Earth's final frontiers shows that there's life and an active ecosystem one-half mile below the surface of the West Antarctic Ice Sheet, specifically in a lake that hasn't seen sunlight or felt a breath of wind for millions of years. The life is in the form of microorganisms that live beneath the enormous Antarctic ice sheet and convert ammonium and methane into the energy required for growth.

Jurassic mammals were picky eaters, new study finds

Posted: 20 Aug 2014 10:59 AM PDT

New analyses of tiny fossil mammals from Glamorgan, South Wales are shedding light on the function and diets of our earliest ancestors, a team reports. Mammals and their immediate ancestors from the Jurassic period (201-145 million years ago) developed new characteristics - such as better hearing and teeth capable of precise chewing.

Experts denounce clinical trials of unscientific, 'alternative' medicines

Posted: 20 Aug 2014 09:32 AM PDT

Experts call for an end to clinical trials of 'highly implausible treatments' such as homeopathy and reiki. Over the last two decades, such complementary and alternative medicine treatments have been embraced in medical academia despite budget constraints and the fact that they rest on dubious science, they say.

Scientists learn more about rare skin cancer that killed Bob Marley

Posted: 20 Aug 2014 09:32 AM PDT

Acral melanomas, the rare type of skin cancer that caused musician Bob Marley's death, are genetically distinct from other types of skin cancer. Acral melanoma most often affects the palms of the hands, soles of the feet, nail-beds and other hairless parts of the skin. Unlike other more common types of melanoma, it's not caused by UV damage from the sun.

Teen sleeplessness piles on risk for obesity

Posted: 20 Aug 2014 08:19 AM PDT

Teenagers who don't get enough sleep may wake up to worse consequences than nodding off during chemistry class. According to new research, risk of being obese by age 21 was 20 percent higher among 16-year-olds who got less than six hours of sleep a night, compared with their peers who slumbered more than eight hours.

Severe infections with hospitalization after prostate biopsy rising in Sweden

Posted: 20 Aug 2014 08:17 AM PDT

Transrectal ultrasound guided biopsy is the gold standard for detecting prostate cancer, but international reports have suggested that the number of risks associated with the procedure is increasing. In a new nationwide population-based study, Swedish researchers found that six percent of men filled a prescription for antibiotics for a urinary tract infection within 30 days after having a prostate biopsy, with a twofold increase in hospital admissions over five years.

Sleepy college students stressed by jobs

Posted: 20 Aug 2014 08:17 AM PDT

College students are typically more sleep deprived than the rest of us and often ignore the health benefits of adequate slumber, said a researcher who studies the topic. "Sleep is extremely important to overall health," one researcher said. "Poor sleep has short-term consequences on mood, concentration, higher learning and can lead to the dangers involved in drowsy driving. "It also has long-term ramifications on our overall health. Research has found links between poor sleep and diabetes, cardiovascular disease and obesity."

Novel gene predicts both breast cancer relapse, response to chemotherapy

Posted: 20 Aug 2014 08:06 AM PDT

Scientists have made it easier to predict both breast cancer relapses and responses to chemotherapy, through the identification of a unique gene. The newly found marker could help doctors classify each breast cancer patient and customize a treatment regimen that is more effective.

Gene therapy protects mice from lethal heart condition, researchers find

Posted: 20 Aug 2014 08:06 AM PDT

A new gene therapy has been shown to protect mice from a life-threatening heart condition caused by muscular dystrophy. About one in 3,500 children, mostly boys, are born with Duchenne muscular dystrophy (DMD). They experience a progressive wasting away of muscles, starting in the legs and pelvis. Children with DMD have difficulty walking, and most need wheelchairs by age 12.

The power of salt: Power generation from where river water and seawater meet

Posted: 20 Aug 2014 08:05 AM PDT

Where the river meets the sea, there is the potential to harness a significant amount of renewable energy, according to a team of mechanical engineers. The researchers evaluated an emerging method of power generation called pressure retarded osmosis (PRO), in which two streams of different salinity are mixed to produce energy. In principle, a PRO system would take in river water and seawater on either side of a semi-permeable membrane. Through osmosis, water from the less-salty stream would cross the membrane to a pre-pressurized saltier side, creating a flow that can be sent through a turbine to recover power.

Turning waste from rice, parsley and other foods into biodegradable plastic

Posted: 20 Aug 2014 08:05 AM PDT

Your chairs, synthetic rugs and plastic bags could one day be made out of cocoa, rice and vegetable waste rather than petroleum, scientists are now reporting. The novel process they developed and their results could help the world deal with its agricultural and plastic waste problems.

Coronary arteries hold heart-regenerating cells

Posted: 20 Aug 2014 08:05 AM PDT

Endothelial cells residing in the coronary arteries can function as cardiac stem cells to produce new heart muscle tissue, investigators have discovered. The heart has long been considered to be an organ without regenerative potential, said one expert. Recent findings, however, have demonstrated that new heart muscle cells are generated at a low rate, suggesting the presence of cardiac stem cells. The source of these cells was unknown.

Treating pain by blocking the 'chili-pepper receptor'

Posted: 20 Aug 2014 08:05 AM PDT

Biting into a chili pepper causes a burning spiciness that is irresistible to some, but intolerable to others. Scientists exploring the chili pepper's effect are using their findings to develop a new drug candidate for many kinds of pain, which can be caused by inflammation or other problems. They have now reported their progress on the compound, which is being tested in clinical trials.

Sunblock poses potential hazard to sea life

Posted: 20 Aug 2014 08:05 AM PDT

The sweet and salty aroma of sunscreen and seawater signals a relaxing trip to the shore. But scientists are now reporting that the idyllic beach vacation comes with an environmental hitch. When certain sunblock ingredients wash off skin and into the sea, they can become toxic to some of the ocean's tiniest inhabitants, which are the main course for many other marine animals.

Record decline of ice sheets: Scientists map elevation changes of Greenlandic and Antarctic glaciers

Posted: 20 Aug 2014 08:05 AM PDT

Researchers have for the first time extensively mapped Greenland's and Antarctica's ice sheets with the help of the ESA satellite CryoSat-2 and have thus been able to prove that the ice crusts of both regions momentarily decline at an unprecedented rate. In total the ice sheets are losing around 500 cubic kilometers of ice per year.

Seeing a molecule breathe through scattering of light pulses

Posted: 20 Aug 2014 08:04 AM PDT

For the first time, chemists have succeeded in measuring vibrational motion of a single molecule with a femtosecond time resolution. The study reveals how vibration of a single molecule differs from the behavior of larger molecular groups. Seeing a single organic bipyridylethylene (BPE) molecule vibrate as a function of time was possible through the scattering of the light pulses. The method is known as time-resolved coherent anti-Stokes Raman scattering (tr-CARS).

Paving the way for cyborg moth 'biobots'

Posted: 20 Aug 2014 06:17 AM PDT

Researchers have developed methods for electronically manipulating the flight muscles of moths and for monitoring the electrical signals moths use to control those muscles. The work opens the door to the development of remotely-controlled moths, or 'biobots,' for use in emergency response.

Is China's 50 percent cesarean section delivery rate too high?

Posted: 20 Aug 2014 06:16 AM PDT

Efforts must be made to decrease China's increasing cesarean section rate, suggests a new article. China has one of the highest caesarean delivery rates in the world. Of 16 million babies born in 2010, approximately half were by caesarean. Although the exact rate is not known, the current Chinese language literature on caesarean rates in China reports total caesarean rates ranging from 36% to 58%. However, before the 1980s, the caesarean rate was below 5% and it did not rise above 10% until after 1990.

Worker bees ‘know’ when to invest in their reproductive future

Posted: 20 Aug 2014 06:16 AM PDT

When a colony of honeybees grows to about 4,000 members, it triggers an important first stage in its reproductive cycle: the building of a special type of comb used for rearing male reproductive, called drones.

A semi-artificial leaf faster than 'natural' photosynthesis

Posted: 20 Aug 2014 06:16 AM PDT

Cooperation between chemists and biologists has resulted in a new method for the very efficient integration of photosynthetic proteins in photovoltaics. Their research offers a new immobilization strategy that yields electron transfer rates exceeding for the first time rates observed in natural photosynthesis. This discovery opens the possibility for the construction of semi-artificial leaves functioning as photovoltaic devices with drastically increased performance.

Type-1, type-2 diabetes caused by same underlying mechanism? Toxic clumps of hormone amylin may be to blame

Posted: 20 Aug 2014 06:16 AM PDT

New findings provide compelling evidence that juvenile-onset or type-1 diabetes and type-2 diabetes are both caused by the formation of toxic clumps of a hormone called amylin. The results suggest that type-1 and type-2 diabetes could both be slowed down and potentially reversed by medicines that stop amylin forming these toxic clumps.

Progress in the fight against harmful fungi

Posted: 20 Aug 2014 06:13 AM PDT

One of the world's largest gene libraries for the Candida glabrata yeast, which is harmful to humans, has been developed by researchers. Molecular analysis of the Candida glabrata fungus mutations led to the discovery of 28 new genes that are partly responsible for the yeast's tolerance of common drugs. Infectious diseases caused by fungi, viruses, bacteria and parasites represent the world's number one cause of death. A few dozen types of harmful fungi claim more than 1.5 million human lives every year.

Zipper action triggers bacterial invasion: Scientists discover new strategy germs use to invade cells

Posted: 20 Aug 2014 06:12 AM PDT

The hospital germ Pseudomonas aeruginosa wraps itself into the membrane of human cells. Now researchers have identified a novel mechanism of bacterial invasion, outlining how Pseudomonas aeruginosa uses lipids in the cell membrane to make its way into host cells.

First LOFAR observations of 'Whirlpool Galaxy'

Posted: 20 Aug 2014 06:12 AM PDT

Using a radio telescope with frequencies just above those of commercial FM radio stations, a European team of astronomers has obtained the most sensitive image of a galaxy below 1 GHz.

A spectacular landscape of star formation

Posted: 20 Aug 2014 06:12 AM PDT

A new image shows two dramatic star formation regions in the southern Milky Way. The first is of these, on the left, is dominated by the star cluster NGC 3603, located 20,000 light-years away, in the Carina–Sagittarius spiral arm of the Milky Way galaxy. The second object, on the right, is a collection of glowing gas clouds known as NGC 3576 that lies only about half as far from Earth.

Why elderly are prone to sleep problems

Posted: 20 Aug 2014 06:10 AM PDT

A group of inhibitory neurons, whose loss leads to sleep disruption in experimental animals, are substantially diminished among the elderly and individuals with Alzheimer's disease, researchers have found. The authors examined the brains of 45 study subjects (median age at death, 89.2), identifying ventrolateral preoptic neurons by staining the brains for the neurotransmitter galanin. They then correlated the actigraphic rest-activity behavior of the 45 individuals in the year prior to their deaths with the number of remaining ventrolateral preoptic neurons at autopsy.

Targeted brain training may help you multitask better

Posted: 20 Aug 2014 06:10 AM PDT

The area of the brain involved in multitasking and ways to train it have been identified by a research team. The research includes a model to better predict the effectiveness of this training.

Growing up poor affects adults' sense of control, impulsiveness when faced with economic uncertainty

Posted: 20 Aug 2014 06:10 AM PDT

Growing up poor can influence people's sense of control and in turn may lead them to more impulsive decision-making and quickly give up on challenging tasks in uncertain situations, according to new research.

Solar energy that doesn't block the view

Posted: 19 Aug 2014 05:02 PM PDT

Researchers have developed a new type of solar concentrator that when placed over a window creates solar energy while allowing people to actually see through the window. It is called a transparent luminescent solar concentrator and can be used on buildings, cell phones and any other device that has a flat, clear surface.

Nuclear magnetic resonance experiments using Earth's magnetic field

Posted: 19 Aug 2014 05:02 PM PDT

Earth's magnetic field, a familiar directional indicator over long distances, is routinely probed in applications ranging from geology to archaeology. Now it has provided the basis for a technique which might, one day, be used to characterize the chemical composition of fluid mixtures in their native environments. Researchers have carried out nuclear magnetic resonance experiments using an ultra-low magnetic field comparable to Earth's magnetic field.

'Tickling' your ear could be good for your heart

Posted: 19 Aug 2014 05:02 PM PDT

Stimulating nerves in your ear could improve the health of your heart, researchers have discovered. Scientists used a standard TENS machine like those designed to relieve labour pains to apply electrical pulses to the tragus, the small raised flap at the front of the ear immediately in front of the ear canal.

Dyslexia: Balanced view needed on expensive lenses to improve reading

Posted: 19 Aug 2014 05:01 PM PDT

Dyslexia charities should give a more balanced account of the evidence for colored overlays and lenses in dyslexia, say experts. An accumulation of evidence supports the view that dyslexia is a verbal (not visual) disorder, and shows that reading difficulties are best addressed by interventions that target underlying weaknesses in phonological language skills and letter knowledge.

Engineering bone growth: Coated tissue scaffolds help body grow new bone to repair injuries or congenital defects

Posted: 19 Aug 2014 12:53 PM PDT

Chemical engineers have devised a new implantable tissue scaffold coated with bone growth factors that are released slowly over a few weeks. When applied to bone injuries or defects, this coated scaffold induces the body to rapidly form new bone that looks and behaves just like the original tissue. This type of coated scaffold could offer a dramatic improvement over the current standard for treating bone injuries, which involves transplanting bone from another part of the patient's body -- a painful process that does not always supply enough bone.

Seafood substitutions can expose consumers to unexpectedly high mercury

Posted: 19 Aug 2014 12:53 PM PDT

New measurements from fish purchased at retail seafood counters in 10 different states show the extent to which mislabeling can expose consumers to unexpectedly high levels of mercury, a harmful pollutant. Fishery stock 'substitutions' -- which falsely present a fish of the same species, but from a different geographic origin -- are the most dangerous mislabeling offense, according to new research.

Philippine tarsier: Genetic proof of a new variety

Posted: 19 Aug 2014 12:53 PM PDT

The tarsier is the 'flagship' iconic species for promoting environmental stewardship and ecotourism in the Philippines, a nation suffering from large-scale destruction of natural habitat.

Blood glucose levels measured in hospitalized patients can predict risk of type 2 diabetes

Posted: 19 Aug 2014 12:53 PM PDT

Blood glucose levels measured in hospitalized adults during acute illness can be used to predict risk of developing type 2 diabetes over the following three years, according to a new study.

Bubbling down: Discovery suggests surprising uses for common bubbles

Posted: 19 Aug 2014 09:59 AM PDT

In a finding with scientific and industrial applications, researchers find that bursting bubbles can push tiny particles down into a liquid as well as up into the air.

Major step toward optical computing: Non-metallic metamaterial used to 'compress' and contain light

Posted: 19 Aug 2014 09:59 AM PDT

Engineering researchers are designing nano-optical cables small enough to replace the copper wiring on computer chips. The advance could result in radical increases in computing speeds and reduced energy use by electronic devices.

Сalculations with nanoscale smart particles: Important step towards creating medical nanorobots

Posted: 19 Aug 2014 08:32 AM PDT

Researchers in Russia have made an important step towards creating medical nanorobots, discovering a way of enabling them to produce logical calculations using a variety of biochemical reactions.

Neither too hot nor too cold: Evolution of marine crocodilians constrained by ocean temperatures

Posted: 19 Aug 2014 08:31 AM PDT

The ancestors of today's crocodiles colonized the seas during warm phases and became extinct during cold phases, according to a new Anglo-French study which establishes a link between marine crocodilian diversity and the evolution of sea temperature over a period of more than 140 million years.

How worms crawl: mathematical model challenges traditional view

Posted: 19 Aug 2014 08:30 AM PDT

A new mathematical model for earthworms and insect larvae challenges the traditional view of how these soft bodied animals get around. Researchers say that there is a far greater role for the body's mechanical properties and the local nerves which react to the surface that the animal is traveling across.

First indirect evidence of so-far undetected strange baryons

Posted: 19 Aug 2014 08:30 AM PDT

New supercomputing calculations provide the first evidence that particles predicted by the theory of quark-gluon interactions but never before observed are being produced in heavy-ion collisions at the Relativistic Heavy Ion Collider.

How steroid hormones enable plants to grow

Posted: 19 Aug 2014 08:30 AM PDT

Plants can adapt extremely quickly to changes in their environment. Hormones, chemical messengers that are activated in direct response to light and temperature stimuli help them achieve this. Plant steroid hormones similar to human sex hormones play a key role here. In a new article, scientists describe a new signaling mode for the brassinosteroid class of hormones.

Exporting U.S. coal to Asia could drop emissions 21 percent

Posted: 19 Aug 2014 08:30 AM PDT

Under the right scenario, exporting U.S. coal to power plants in South Korea could lead to a 21 percent drop in greenhouse gas emissions compared to burning it at less energy-efficient U.S. plants. Other emissions, including sulfur dioxide, nitrogen oxide and particulate matter, could also drop. But this success, researchers say, depends on which fuel source the coal replaces in South Korea, and which fuel is used to replace it in the U.S.

Zebrafish help unravel Alzheimer's disease

Posted: 19 Aug 2014 08:30 AM PDT

New fundamental knowledge about the regulation of stem cells in the nerve tissue of zebrafish embryos results in surprising insights into neurodegenerative disease processes in the human brain. A new study identifies the molecules responsible for this process.

Why global warming is taking a break

Posted: 19 Aug 2014 08:30 AM PDT

The average temperature on Earth has barely risen over the past 16 years. Researchers in Switzerland have now found out why. And they believe that global warming is likely to continue again soon.

Organic photovoltaic cells of the future: Using charge formation efficiency to screen materials for future devices

Posted: 19 Aug 2014 08:29 AM PDT

Organic photovoltaic cells -- a type of solar cell that uses polymeric materials to capture sunlight -- show tremendous promise as energy conversion devices, thanks to key attributes such as flexibility and low-cost production, but have complex power conversion processes. To maneuver around this problem, researchers have developed a method to determine the absolute value of the charge formation efficiency. The secret of their method is the combination of two types of spectroscopy.

Martian meteorite: Implications of a newly discovered mineral-rich structure

Posted: 19 Aug 2014 08:29 AM PDT

A new ovoid structure discovered in the Nakhla Martian meteorite is made of nanocrystalline iron-rich clay, contains a variety of minerals, and shows evidence of undergoing a past shock event from impact, with resulting melting of the permafrost and mixing of surface and subsurface fluids.

What are stars made of? Determining stellar compositions made easier with new catalog

Posted: 19 Aug 2014 06:41 AM PDT

An astronomer has devised the largest catalog ever produced for stellar compositions. The work is critical to understanding the properties of stars, how they form, and possible connections with orbiting planets. And what she found from her work is that the compositions of nearby stars aren't as uniform as once thought.

Study at Deepwater Horizon spill site finds key to tracking pollutants

Posted: 19 Aug 2014 06:41 AM PDT

A new study of the ocean circulation patterns at the site of the Deepwater Horizon oil spill reveals the significant role small-scale ocean currents play in the spread of pollutants. The findings provide new information to help predict the movements of oil and other pollutants in the ocean.

Hand gestures improve learning in both signers, speakers

Posted: 19 Aug 2014 06:40 AM PDT

Spontaneous gesture can help children learn, whether they use a spoken language or sign language, according to a new report. "Children who can hear use gesture along with speech to communicate as they acquire spoken language," a researcher said. "Those gesture-plus-word combinations precede and predict the acquisition of word combinations that convey the same notions. The findings make it clear that children have an understanding of these notions before they are able to express them in speech."

Studies promoting use of antidepressants for postoperative pain may be premature, review finds

Posted: 19 Aug 2014 06:40 AM PDT

Antidepressants are known to provide effective pain relief for various chronic pain conditions; however, the jury is still out on their use in treating the millions of patients who suffer from acute or chronic pain following surgery. A first-of-its-kind literature review suggests although a majority of studies report positive outcomes, there is currently insufficient evidence to support the clinical use of antidepressants for the treatment of postoperative pain.

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