Παρασκευή, 23 Μαΐου 2014

ScienceDaily: Latest Science News

ScienceDaily: Latest Science News


Biofilm defense: Mechanisms and actions of a new class of broad-spectrum antimicrobials

Posted: 22 May 2014 02:57 PM PDT

Last month WHO issued a report that warned of an increase of antimicrobial-resistance and the renewed threat of bacterial infections world-wide and called for a concerted effort to develop new and better antimicrobial drugs. A new study reveals how a new type of antimicrobial substance interferes with biofilms formed by several dangerous bacteria.

NASA Mars weathercam helps find big new crater

Posted: 22 May 2014 01:29 PM PDT

Researchers have discovered on the Red Planet the largest fresh meteor-impact crater ever firmly documented with before-and-after images. The images were captured by NASA's Mars Reconnaissance Orbiter. The crater spans half the length of a football field and first appeared in March 2012. The impact that created it likely was preceded by an explosion in the Martian sky caused by intense friction between an incoming asteroid and the planet's atmosphere.

NASA's WISE findings poke hole in black hole 'doughnut' theory

Posted: 22 May 2014 01:23 PM PDT

A survey of more than 170,000 supermassive black holes, using NASA's Wide-field Infrared Survey Explorer (WISE), has astronomers reexamining a decades-old theory about the varying appearances of these interstellar objects. The unified theory of active, supermassive black holes, first developed in the late 1970s, was created to explain why black holes, though similar in nature, can look completely different. Some appear to be shrouded in dust, while others are exposed and easy to see.

New 'T-ray' tech converts light to sound for weapons detection, medical imaging

Posted: 22 May 2014 12:05 PM PDT

A device that essentially listens for light waves could help open up the last frontier of the electromagnetic spectrum -- the terahertz range. So-called T-rays, which are light waves too long for human eyes to see, could help airport security guards find chemical and other weapons. They might let doctors image body tissues with less damage to healthy areas. And they could give astronomers new tools to study planets in other solar systems. Those are just a few possible applications.

Delegating dirty work is key to evolution: Working cells allow organisms to evolve

Posted: 22 May 2014 11:14 AM PDT

We have hundreds of types of cells in our bodies -- everything from red blood cells to hair follicles to neurons. But why can't most of them create offspring for us? New research suggests that separating germ cells -- sperm and eggs -- from somatic cells -- all other cells -- preserves the genetic building blocks while allowing organisms to flourish in a somewhat hazardous environment.

Deep Earth recycling of the oceanic floor: New insight into the temperature of deep Earth

Posted: 22 May 2014 11:14 AM PDT

Scientists have recreated the extreme conditions 600 to 2900 km below the Earth's surface to investigate the melting of basalt in the oceanic tectonic plates. They exposed microscopic pieces of rock to these extreme pressures and temperatures while simultaneously studying their structure. The results show basalt produced on the ocean floor has a melting temperature lower than the peridotite which forms the Earth's mantle.

Not all diamonds are forever: Researchers see nanodiamonds created in coal fade away in seconds

Posted: 22 May 2014 11:14 AM PDT

Scientists show that some diamonds are not forever. Through the creation of nanodiamonds in treated coal scientists also show that some microscopic diamonds only last seconds before fading back into less-structured forms of carbon under the impact of an electron beam.

Earth's lower mantle may be significantly different than previously thought

Posted: 22 May 2014 11:14 AM PDT

Breaking research news reveals that the composition of the Earth's lower mantle may be significantly different than previously thought. The lower mantle comprises 55 percent of the planet by volume and extends from 670 and 2900 kilometers in depth, as defined by the so-called transition zone (top) and the core-mantle boundary (below). Pressures in the lower mantle start at 237,000 times atmospheric pressure (24 gigapascals) and reach 1.3 million times atmospheric pressure (136 gigapascals) at the core-mantle boundary.

Fruit flies show mark of intelligence in thinking before they act, study suggests

Posted: 22 May 2014 11:14 AM PDT

Fruit flies 'think' before they act, a study suggests. Neuroscientists showed that fruit flies take longer to make more difficult decisions. In experiments asking fruit flies to distinguish between ever closer concentrations of an odor, the researchers found that the flies don't act instinctively or impulsively. Instead they appear to accumulate information before committing to a choice.

A glimpse into nature's looking glass -- to find the genetic code is reassigned: Stop codon varies widely

Posted: 22 May 2014 11:14 AM PDT

It has long been assumed that there is only one 'canonical' genetic code, so each word means the same thing to every organism. Now, this paradigm has been challenged by the discovery of large numbers of exceptions from the canonical genetic code.

Ancient DNA ends Australia's claim to kiwi origins

Posted: 22 May 2014 11:13 AM PDT

Australia can no longer lay claim to the origins of the iconic New Zealand kiwi following new research showing the kiwi's closest relative is not the emu as was previously thought. Instead, the diminutive kiwi is most closely related to the extinct Madagascan elephant bird -- a 2-3 meter tall, 275 kg giant. And surprisingly, the study concluded, both of these flightless birds once flew.

Collecting biological specimens essential to science and conservation, experts argue

Posted: 22 May 2014 11:13 AM PDT

Collecting plant and animal specimens is essential for scientific studies and conservation and does not, as some critics of the practice have suggested, play a significant role in species extinctions. Those are the conclusions of more than 100 biologists and biodiversity researchers.

Growing inequalities make science more of a 'winner takes all' field

Posted: 22 May 2014 11:13 AM PDT

As new research documents growing inequalities in health and wealth, the gap between "haves" and "have-nots" is growing in the field of scientific research itself, says a sociologist.

Near-normal or below-normal 2014 Atlantic hurricane season predicted

Posted: 22 May 2014 10:28 AM PDT

In its 2014 Atlantic hurricane season outlook issued today NOAA's Climate Prediction Center is forecasting a near-normal or below-normal season. The main driver of this year's outlook is the anticipated development of El Niño this summer. El Niño causes stronger wind shear, which reduces the number and intensity of tropical storms and hurricanes. El Niño can also strengthen the trade winds and increase the atmospheric stability across the tropical Atlantic, making it more difficult for cloud systems coming off of Africa to intensify into tropical storms.

Near-normal or above-normal Eastern Pacific hurricane season predicted

Posted: 22 May 2014 10:25 AM PDT

NOAA's Climate Prediction Center has announced that a near-normal or above-normal hurricane season is likely for the Eastern Pacific this year. The outlook calls for a 50 percent chance of an above-normal season, a 40 percent chance of a near-normal season, and a 10 percent chance of a below normal season.

Near-normal or above-normal Central Pacific hurricane season predicted

Posted: 22 May 2014 10:21 AM PDT

NOAA's Central Pacific Hurricane Center announced that climate conditions point to a near-normal or above-normal season in the Central Pacific Basin this year. For 2014, the outlook calls for a 40 percent chance of a near-normal season, a 40 percent chance of an above-normal season, and a 20 percent chance of a below-normal season.

'I can' mentality goes long way after childbirth

Posted: 22 May 2014 09:35 AM PDT

The way a woman feels about tackling everyday physical activities, including exercise, may be a predictor of how much weight she'll retain years after childbirth says a professor. A study followed 56 women during pregnancy and measured their physical activity levels, along with barriers to exercise and the ability to overcome them. Six years later, the research team followed up with more than half of the participants and found that the women who considered themselves less able to take on these barriers had retained more of their pregnancy weight. Top barriers identified in the study included time, motivation and childcare issues.

Blocking pain receptors extends lifespan, boosts metabolism in mice

Posted: 22 May 2014 09:35 AM PDT

Chronic pain is known to shorten lifespan, and pain tends to increase with age. But is there a relationship between pain and longevity? Researchers have found that mice lacking the capsaicin pain receptor live around 14 percent longer than other mice, and they retain a more youthful metabolism as well. Receptor blockers could not only relieve pain, but increase lifespan, improve metabolic health and help diabetics and the obese.

Computer models helping unravel the science of life? How cells of the fruit fly react to changes in the environment

Posted: 22 May 2014 09:35 AM PDT

Scientists have developed a sophisticated computer modelling simulation to explore how cells of the fruit fly react to changes in the environment. The model shows how cells of the fruit fly communicate with each other during its development.

Gene behind unhealthy adipose tissue identified

Posted: 22 May 2014 09:35 AM PDT

A gene driving the development of pernicious adipose tissue in humans has been identified by researchers for the first time. The findings imply that the gene may constitute a risk factor promoting the development of insulin resistance and type 2 diabetes. "Our findings represent an important step forward in the understanding of how adipose tissue links to the development of metabolic disease," comments one of the principal investigators.

Safe alternatives to BPA: New technology may help identify

Posted: 22 May 2014 09:34 AM PDT

Numerous studies have linked exposure to bisphenol A (BPA) in plastic, receipt paper, toys, and other products with various health problems from poor growth to cancer, and the FDA has been supporting efforts to find and use alternatives. But are these alternatives safer? Researchers have developed new tests that can classify such compounds' activity with great detail and speed. The advance could offer a fast and cost-effective way to identify safe replacements for BPA.

Wondering about state of the environment? Just eavesdrop on bees

Posted: 22 May 2014 09:34 AM PDT

Want a simple way to monitor wide swaths of the landscape without breaking a sweat? Listen in on the 'conversations' honeybees have with each other, researchers suggest. The scientists' analyses of honeybee waggle dances suggest that costly measures to set aside agricultural lands and let the wildflowers grow can be very beneficial to bees.

HIV-positive children more likely to develop drug resistance

Posted: 22 May 2014 09:33 AM PDT

74 percent of HIV-positive children in a study developed resistance to at least one form of drug treatment. The researchers followed almost 450 children enrolled in the Pediatric HIV/AIDS Cohort Study, one of the largest studies of HIV-positive children in the United States. "The problem with drug resistance is that once you develop it, it never goes away," said the principal investigator. "Some patients with very resistant virus have no effective treatment options. Resistant virus is the major reason for death among youth with perinatal HIV."

Some pancreatic cancer treatments may be going after wrong targets

Posted: 22 May 2014 09:33 AM PDT

New research represents a significant change in the understanding of how pancreatic cancer grows – and how it might be defeated. Unlike other types of cancer, pancreatic cancer produces a lot of scar tissue and inflammation. For years, researchers believed that this scar tissue, called desmoplasia, helped the tumor grow, and they've designed treatments to attack this. But new research finds that when you eliminate desmoplasia, tumors grow even more quickly and aggressively. In the study, mice in which the desmoplasia was eliminated developed tumors earlier and died sooner.

Putting a number on opinion dynamics in a population

Posted: 22 May 2014 08:58 AM PDT

Opinion formation in a large population is influenced by both endogenous factors, such as interaction with one's peers, as well as exogenous factors, such as the media. In a recent paper, authors use a mathematical model to study the process of information assimilation in a population resulting from such exogenous inputs.

Screening for autism: There's an app for that

Posted: 22 May 2014 08:57 AM PDT

Software to help interpret videotaped behaviors of infants during autism screening tests has been developed by researchers. The program's accuracy proved equal to autism experts and better than both non-expert medical clinicians and students in training. "The great benefit of the video and software is for general practitioners who do not have the trained eye to look for subtle early warning signs of autism," said one researcher involved in the study.

Drug-target database lets researchers match old drugs to new uses

Posted: 22 May 2014 07:51 AM PDT

There are thousands of drugs that silence many thousands of cancer-causing genetic abnormalities. Some of these drugs are in use now, but many of these drugs are sitting on shelves or could be used beyond the disease for which they were originally approved. Repurposing these drugs depends on matching drugs to targets. A study recently published describes a new database and pattern-matching algorithm that allows researchers to evaluate rational drugs and drug combinations, and also recommends a new drug combination to treat drug-resistant non-small cell lung cancer.

Medical students may benefit from social media guidance

Posted: 22 May 2014 07:51 AM PDT

Medical students use social media extensively, but medical schools may need to offer more guidance in potential pitfalls, according researchers. "We assessed how medical students engage with social media platforms like Facebook and found that they have a pretty sophisticated understanding of its risks and benefits," said one researcher. Two reports outline findings from a survey of 2,109 medical students.

Pathology of Sanfilippo A syndrome: Research provides more insight

Posted: 22 May 2014 07:51 AM PDT

Sanfilippo A syndrome is a rare genetic lysosomal storage disease inherited from the parents of the patient. Lysosomes are the body's vehicle for breaking down many of its by-products such as proteins, nucleic acids, carbohydrates, lipids and cellular debris. New research advances the knowledge of the structural features of sulfamidase in the context of this illness, and will greatly facilitate the discovery of suitable compounds and drugs to assist in managing the disease and its debilitating effects.

Fossil avatars are transforming palaeontology

Posted: 22 May 2014 07:51 AM PDT

New techniques for visualizing fossils are transforming our understanding of evolutionary history. Palaeontology has traditionally proceeded slowly, with individual scientists labouring for years or even decades over the interpretation of single fossils. The introduction of X-ray tomography has revolutionized the way that fossils are studied, allowing them to be virtually extracted from the rock in a fraction of the time necessary to prepare specimens by hand and without the risk of damaging the fossil.

Bipolar disease in children, adolescents: Discharge rates much higher in the US compared to UK

Posted: 22 May 2014 07:50 AM PDT

A significantly higher discharge rate for pediatric bipolar in children and adolescents aged 1-19 years has been found in the US compared to England. "The finding that the disparity between US and English discharge rates for PBD is markedly greater than the disparity for child psychiatric discharge rates overall, and for adult rates for bipolar disorder, is potentially important. However, the study design does not allow us to answer the question whether US clinicians are too liberal in assigning the diagnosis of bipolar disorder to youth or, alternatively, whether English clinicians fail to recognize or diagnose these illnesses. It is clear that the reasons for the disparity in the case of PBD warrant further study," the lead author says.

Alcoholism treatment: Kappa opioid receptors a new target

Posted: 22 May 2014 07:50 AM PDT

The list of brain receptor targets for opiates reads like a fraternity: Mu Delta Kappa. The mu opioid receptor is the primary target for morphine and endogenous opioids like endorphin, whereas the delta opioid receptor shows the highest affinity for endogenous enkephalins. The kappa opioid receptor is very interesting, but the least understood of the opiate receptor family.

European farmers: Importance of adapting to climate change

Posted: 22 May 2014 07:49 AM PDT

Farmers in Europe will see crop yields affected as global temperatures rise, but that adaptation can help slow the decline for some crops. Research reveals that farmers in Europe will see crop yields affected as global temperatures rise, but that adaptation can help slow the decline for some crops. For corn, the anticipated loss is roughly 10 percent, the research shows. Farmers of these crops have already seen yield growth slow down since 1980 as temperatures have risen, though other policy and economic factors have also played a role.

First broadband wireless connection ... to the moon: Record-shattering Earth-to-Moon uplink

Posted: 22 May 2014 07:49 AM PDT

Scientists have prepared new details and the first comprehensive overview of the on-orbit performance of their record-shattering laser-based communication uplink between the moon and Earth, which beat the previous record transmission speed last fall by a factor of 4,800.

There is still hope for the climate: Regional cures for planetary fever

Posted: 22 May 2014 07:48 AM PDT

There is still hope for the climate, even if a world-wide climate accord proves to be unattainable. A new report shows that regional measures can hold the global rise in temperature within the two-degree limit.

Devastating human impact on the Amazon rainforest revealed

Posted: 22 May 2014 07:48 AM PDT

The human impact on the Amazon rainforest has been grossly underestimated according to an international team of researchers. They found that selective logging and surface wildfires can result in an annual loss of 54 billion tons of carbon from the Brazilian Amazon, increasing greenhouse gas emissions. This is equivalent to 40% of the yearly carbon loss from deforestation -- when entire forests are chopped down.

Stem-cell research: A new genetic switching element

Posted: 22 May 2014 07:48 AM PDT

Every cell contains stored hereditary information, encoded in the sequence of nucleobases that make up its DNA. However, in any given cell type, only a fraction of this information is actually used. Which genes are activated and which are turned off is in part determined by a second tier of information which is superimposed on the nucleotide sequences that provide the blueprints for protein synthesis. This so-called epigenetic level of control is based on the localized, and in principle reversible, attachment of simple chemical tags to specific nucleotides in the genome. Slight modifications in genome sequences play a crucial role in the conversion of pluripotent stem cells into various differentiated cell types.

Marriage of convenience with a fungus: Equal for all plants, or just some?

Posted: 22 May 2014 07:48 AM PDT

Thanks to a fungus, the medicinal plant ribwort plantain gains a higher concentration of the defensive compound catalpol. The increase in catalpol gives the plant better protection against pests. In the study, the research team worked with arbuscular mycorrhizal fungi. These are known to colonize the roots of land plants. The plants benefit from this because the fungus provides them with nutrients and minerals. However, are the impacts of this marriage of convenience with the fungus on plant chemistry equal for all plants? That is what the researchers wanted to find out.

Inexpensive food a key factor in rising obesity

Posted: 22 May 2014 04:47 AM PDT

An important factor fueling the obesity epidemic has been identified by a new review: Americans now have the cheapest food available in history. Today, two in three Americans are overweight or obese, with rates climbing steadily over the past several decades. Many factors have been suggested as causes: snack food, automobiles, television, fast food, computer use, vending machines, suburban housing developments, and portion size. But after examining available evidence, the authors say widespread availability of inexpensive food appears to have the strongest link to obesity.

Could cannabis active substance curb seizures? Experts weed through evidence

Posted: 22 May 2014 04:47 AM PDT

The therapeutic potential of medical marijuana and pure cannabidiol (CBD), an active substance in the cannabis plant, for neurologic conditions is highly debated. A series of articles examine the potential use of medical marijuana and CBD in treating severe forms of epilepsy such as Dravet syndrome.

New insights into premature ejaculation could lead to better diagnosis, treatment

Posted: 22 May 2014 04:47 AM PDT

There are many misconceptions and unknowns about premature ejaculation in the medical community and the general population. Two new papers provide much-needed answers that could lead to improved diagnosis and treatment for affected men. Premature ejaculation can cause significant personal and interpersonal distress to a man and his partner. While it has been recognized as a syndrome for well over 100 years, the clinical definition of premature ejaculation has been vague, ambiguous, and lacking in objective and quantitative criteria.

Atomic-level protection for drivers

Posted: 22 May 2014 04:44 AM PDT

A new window on the world of atoms will make future vehicles safer in collisions. Scientists have set out on an unusual journey – into the interior of certain materials. They are about to build a mathematical model of tiny but vital zones in aluminum vehicle bumper systems. The research group will use this virtual "mini-laboratory" to study the chaos we create when we crash a car.

Bending helps to control nanomaterials

Posted: 22 May 2014 04:44 AM PDT

A new remedy has been found to tackle the difficulty of controlling layered nanomaterials. Control can be improved by simply bending the material. Bending decreases interaction between layers, making the material merely a stack of independent atomic layers.

Liquid crystal as lubricant

Posted: 22 May 2014 04:44 AM PDT

Thanks to a new lubricant, small gears can run with virtually no friction. Made from liquid crystalline fluid, these lubricants drastically reduce friction and wear.

New way to combat drug resistance in skin cancer found

Posted: 22 May 2014 04:42 AM PDT

Rapid resistance to vemurafenib – a treatment for a type of advanced melanoma, the deadliest form of skin cancer – could be prevented by blocking a druggable family of proteins, according to research. Scientists have revealed the MLK family of four enzymes 'undoes' the tumour-shrinking effects of vemurafenib.

Top ten new species for 2014

Posted: 22 May 2014 04:33 AM PDT

An international committee selected the top 10 from among the approximately 18,000 new species named during the previous year. The list includes a quartet of tiny newcomers to science: a miniscule skeleton shrimp from Santa Catalina Island in California, a single-celled protist that does a credible imitation of a sponge, a clean room microbe that could be a hazard during space travel and a teensy fringed fairyfly named Tinkerbell.

More male bugs in a warmer world? Temperature influences gender of offspring in bugs

Posted: 22 May 2014 04:33 AM PDT

Whether an insect will have a male or female offspring depends on the weather, according to a new study. As in bees, wasps, and ants, the gender determination of Trichogramma parasitoids is called "haplodiploid," that is, fertilized eggs produce female offspring, while unfertilized eggs produce male offspring. The study found that when it was hot, females deliberately produced more males than at medium temperature -- at 34°C, the number of males produced increased by 80%.

Dryland ecosystems emerge as driver in global carbon cycle

Posted: 21 May 2014 03:00 PM PDT

Dryland ecosystems, which include deserts to dry-shrublands, play a more important role in the global carbon cycle than previously thought. In fact, they have emerged as one of its drivers. Surprised by the discovery, researchers urged global ecologists to include the emerging role of dryland ecosystems in their research.

Protective proteins reduce damage to blood vessels

Posted: 21 May 2014 03:00 PM PDT

Proteins found in our blood can reduce damage caused to blood vessels as we age, and in conditions such as atherosclerosis and arthritis, new research finds. Calcification is a major risk factor for heart attack and stroke. Blood vessels can harden as calcium phosphate (CaP) crystals, normally found in bones and teeth, build up in soft tissue as we age or as a result of illness. This can lead to complications in patients with atherosclerosis, a major cause of death whereby arteries thicken and are at risk of becoming blocked.

Ape ancestors' teeth provide glimpse into their diets and environments: Helped apes move to Eurasia, may have led to extinction

Posted: 21 May 2014 03:00 PM PDT

Newly analyzed tooth samples from the great apes of the Miocene indicate that the same dietary specialization that allowed the apes to move from Africa to Eurasia may have led to their extinction. Apes expanded into Eurasia from Africa during the Miocene (14 to 7 million years ago) and evolved to survive in new habitat. Their diet closely relates to the environment in which they live and each type of diet wears the teeth differently.

Peripheral artery disease: Home-based walking program eases clogged leg arteries

Posted: 21 May 2014 03:00 PM PDT

A home-based exercise program helped people with clogged leg arteries walk farther and faster. Supervised exercise for peripheral artery disease is not usually covered by insurance and is inaccessible for many people with this painful condition. Physicians should recommend walking even if their patients don't have access to a supervised exercise program.

Misguided DNA-repair proteins caught in the act

Posted: 21 May 2014 02:59 PM PDT

Accumulation of DNA damage can cause aggressive forms of cancer and accelerated aging, so the body's DNA repair mechanisms are normally key to good health. However, in some diseases the DNA repair machinery can become harmful. Scientists have discovered some of the key proteins involved in one type of DNA repair gone awry.

Disruption of circadian rhythms may contribute to inflammatory disease

Posted: 21 May 2014 02:59 PM PDT

A disruption of circadian rhythms, when combined with a high-fat, high-sugar diet, may contribute to inflammatory bowel disease and other harmful conditions, according to a recent study. "Circadian rhythms, which impose a 24-hour cycle on our bodies, are different from sleep patterns," the first author of the study explained. "Sleep is a consequence of circadian rhythms." While circadian rhythm disruption may be common among some, the research suggests that it may be contributing to a host of diseases.

New neural pathway found in eyes that aids in vision

Posted: 21 May 2014 01:27 PM PDT

A less-well-known type of retina cell plays a more critical role in vision than previously understood. Working with mice, the scientists found that the ipRGCs -- an atypical type of photoreceptor in the retina -- help detect contrast between light and dark, a crucial element in the formation of visual images. The key to the discovery is the fact that the cells express melanopsin, a type of photopigment that undergoes a chemical change when it absorbs light.

Oil, gas development homogenizing core-forest bird communities

Posted: 21 May 2014 11:24 AM PDT

Conventional oil and gas development in northern Pennsylvania altered bird communities, and the current massive build-out of shale-gas infrastructure may accelerate these changes, according to researchers. The commonwealth's Northern Tier -- one of the largest blocks of Eastern deciduous forest in the entire Appalachian region -- is an important breeding area for neotropical migrant songbirds. These diminutive, insect-eating creatures, which breed in Pennsylvania and winter in Central and South America, contribute greatly to the health of forests.

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