Παρασκευή, 28 Μαρτίου 2014

ScienceDaily: Top News

ScienceDaily: Top News

Consistent blood pressure control may cut rate of second stroke in half

Posted: 27 Mar 2014 02:00 PM PDT

Stroke survivors who consistently control their blood pressure may reduce the likelihood of a second stroke by more than 50 percent. Less than a third of stroke survivors maintained consistent blood pressure control more than 75 percent of the time. Researchers determined results after controlling for age, sex and prior history of stroke, heart disease and other factors. Blood pressure was considered "controlled" at 140 mmHg over 90 mmHg or lower.

First genome methylation mapping in fruit fly

Posted: 27 Mar 2014 11:24 AM PDT

The first mapping of genome methylation in the fruit-fly Drosophila melanogaster has been released by a team of scientists. This paper represents a major advance in the study of DNA methylation in insects. No previous study has succeeded in pinpointing the location of DNA methylation in the fly genome.

New way to filter light: May provide first directional selectivity for light waves

Posted: 27 Mar 2014 11:24 AM PDT

Light waves can be defined by three fundamental characteristics: their color (or wavelength), polarization, and direction. While it has long been possible to selectively filter light according to its color or polarization, selectivity based on the direction of propagation has remained elusive. But now, for the first time, researchers have produced a system that allows light of any color to pass through only if it is coming from one specific angle; the technique reflects all light coming from other directions.

Antidepressants during pregnancy linked to preterm birth

Posted: 27 Mar 2014 11:01 AM PDT

Antidepressant medications taken by pregnant women are associated with increased rates of preterm birth, research shows. This finding reinforces the notion that antidepressants should not be used by pregnant women in the absence of a clear need that cannot be met through alternative approaches, say researchers.

Cancer researchers find key protein link

Posted: 27 Mar 2014 11:00 AM PDT

A new understanding of proteins at the nexus of a cell's decision to survive or die has implications for researchers who study cancer and age-related diseases. Experiments and computer analysis of two key proteins revealed a previously unknown binding interface that could be addressed by medication.

Adult cancer drugs show promise against an aggressive childhood brain tumor

Posted: 27 Mar 2014 10:57 AM PDT

The quest to improve survival of children with a high-risk brain tumor has investigators to two drugs already used to treat adults with breast, pancreatic, lung and other cancers. Researchers demonstrated that the drugs pemetrexed and gemcitabine killed cells from mouse and human brain tumors, called group 3 medulloblastoma, growing in the laboratory. Medulloblastoma is diagnosed in about 400 children annually in the U.S., making it the most common pediatric brain tumor.

Biomarkers predict effectiveness of radiation treatments for cancer

Posted: 27 Mar 2014 09:37 AM PDT

The effectiveness of radiation treatments for patients with squamous cell cancer of the head and neck has been reviewed by an international team of researchers. They identified two biomarkers that were good at predicting a patient's resistance to radiation therapy. "While our findings are encouraging, and a step toward personalized medicine, we hope to do more of this research with a larger, randomized trial," the authors conclude.

Chronic stress in early life causes anxiety, aggression in adulthood, neurobiologists find

Posted: 27 Mar 2014 09:36 AM PDT

In experiments to assess the impacts of social stress upon adolescent mice, both at the time they are experienced and during adulthood, a laboratory team conducted many different kinds of stress tests and means of measuring their impacts. The research indicates that a 'hostile environment in adolescence disturbs psychoemotional state and social behaviors of animals in adult life,' the team says.

New guidance system could improve minimally invasive surgery

Posted: 27 Mar 2014 09:36 AM PDT

A computerized process that could make minimally invasive surgery more accurate and streamlined using equipment already common in the operating room has been developed by researchers.

Seasonal Arctic summer ice extent still hard to forecast, study says

Posted: 27 Mar 2014 09:36 AM PDT

Scientists analyzed 300 summer Arctic sea ice forecasts from 2008 to 2013 and found that forecasts are quite accurate when sea ice conditions are close to the downward trend that has been observed in Arctic sea ice for the last 30 years. However, forecasts are not so accurate when sea ice conditions are unusually higher or lower compared to this trend.

Controlling electron spins by light

Posted: 27 Mar 2014 09:35 AM PDT

Topological insulators are considered a very promising material class for the development of future electronic devices. A research team has discovered, how light can be used to alter the physical properties of the electrons in these materials.

Four in 10 infants lack strong parental attachments

Posted: 27 Mar 2014 09:35 AM PDT

In a study of 14,000 US children, 40 percent lack strong emotional bonds -- what psychologists call 'secure attachment' -- with their parents that are crucial to success later in life, according to a new report. The researchers found that these children are more likely to face educational and behavioral problems.

Foraging bats can warn each other away from their dinners

Posted: 27 Mar 2014 09:35 AM PDT

A new call that some bats use to tell other foraging bats to 'back off' from bugs they've claimed for themselves has been identified by scientists. This sound, called a 'frequency-modulated bout,' warns other bats away from prey. The researchers are first to report this ultrasonic social call produced exclusively by flying, foraging male big brown bats, in a new article.

Inspiration linked to bipolar disorder risk

Posted: 27 Mar 2014 09:33 AM PDT

Inspiration has been linked with people at risk of developing bipolar disorder for the first time in a study. For generations, artists, musicians, poets and writers have described personal experiences of mania and depression, highlighting the unique association between creativity and bipolar disorder -- experiences which are backed up by recent research. But, until now, the specific links between inspiration -- the generation of ideas that form the basis of creative work -- and bipolar disorder has received little attention.

To grow or not to grow: A step forward in adult vertebrate tissue regeneration

Posted: 27 Mar 2014 09:33 AM PDT

The reason why some animals can regenerate tissues after severe organ loss or amputation while others, such as humans, cannot renew some structures has always intrigued scientists. In a study, a research group provided new clues to solve this central question by investigating regeneration in an adult vertebrate model: the zebrafish.

A tale of two species: How woodrats keep to two species

Posted: 27 Mar 2014 09:31 AM PDT

A pair of new studies look at the surprising variety of factors that prevent two closely related species of woodrats from becoming a single hybrid species despite the existence of hybrid individuals where the two species come into contact. After finding that two closely related species could interbreed and produce hybrid offspring, scientists set out to determine why only 14 percent of the population in a "contact zone" had genetic signatures from both species.

'Mini heart' invented to help return venous blood

Posted: 27 Mar 2014 09:31 AM PDT

A new organ has been invented to help return blood flow from veins lacking functional valves. A rhythmically contracting cuff made of cardiac muscle cells surrounds the vein acting as a 'mini heart' to aid blood flow through venous segments. The cuff can be made of a patient's own adult stem cells, eliminating the chance of implant rejection.

Potential target for treating mitochondrial disorders

Posted: 27 Mar 2014 09:31 AM PDT

Mitochondria are essential for proper cellular functions. Mitochondrial defects are often observed in a variety of diseases, including cancer, Alzheimer's disease, and Parkinson's disease, and are the hallmarks of a number of untreatable genetic mitochondrial disorders whose manifestations range from muscle weakness to organ failure. Scientists have identified a protein whose inhibition could hold the key to alleviating suffering caused by such disorders.

New function for important player in immune response uncovered

Posted: 27 Mar 2014 08:17 AM PDT

A new function of AID, a crucial enzyme for the immune response has been uncovered by researchers. The discovery helps explain a rare genetic disorder that causes an immunodeficiency syndrome. AID initiates a mechanism whereby a break occurs in the DNA, within the antibody genes, and a segment is removed. The free ends on either side of the removed fragment must be rejoined to repair the DNA strand and, thus, produce a new class of antibody.

Dynamics behind Arctic ecosystems revealed

Posted: 27 Mar 2014 08:17 AM PDT

Species such as the musk ox, Arctic fox and lemming live in the harsh, cold and deserted tundra environment. However, they have often been in the spotlight when researchers have studied the impact of a warmer climate on the countryside in the north. Until now, the focus has been concentrated on individual species, but an international team of biologists has now published an important study of entire food-web dynamics.

A more potent greenhouse gas than carbon dioxide, methane emissions will leap as Earth warms

Posted: 27 Mar 2014 08:17 AM PDT

New research indicates that for each degree that the Earth's temperature rises, the amount of methane entering the atmosphere from microorganisms dwelling in lake sediment and freshwater wetlands -- the primary sources of the gas -- will increase several times.

The first insects were not yet able to smell well: Odorant receptors evolved long after insects migrated from water to land

Posted: 27 Mar 2014 08:16 AM PDT

An insect's sense of smell is vital to its survival. Only if it can trace even tiny amounts of odor molecules is it is able to find food sources or avoid enemies. According to scientists, many proteins involved in the highly sensitive odor perception of insects emerged rather late in the evolutionary process.

Scientists watch nanoparticles grow: Analysis allows tailoring materials for switchable windows and solar cells

Posted: 27 Mar 2014 08:16 AM PDT

With DESY's X-ray light source PETRA III, scientists have observed the growth of nanoparticles live. The study shows how tungsten oxide nanoparticles are forming from solution. These particles are used for example for smart windows, which become opaque at the flick of a switch, and they are also used in particular solar cells.

Students on field course bag new spider species

Posted: 27 Mar 2014 08:16 AM PDT

As a spin-off of their Tropical Biodiversity course in Malaysian Borneo, a team of biology students discover a new spider species, build a makeshift taxonomy lab, write a joint publication and send it off to a major taxonomic journal. The new species Crassignatha danaugirangensis was named after the field center's idyllic setting at the Danau Girang oxbow lake.

Hubble sees Mars-bound comet sprout multiple jets

Posted: 27 Mar 2014 08:15 AM PDT

A new image of a comet at 353 million miles from Earth shows two jets of dust coming off the comet's nucleus in opposite directions.

Dying cells in fruit fly alert neighboring cells to protect themselves: As a result, neighbors become harder to kill

Posted: 27 Mar 2014 08:12 AM PDT

Cells usually self-destruct when irreparable glitches occur in their DNA. Programmed cell death, or apoptosis, helps insure that cells with damaged DNA do not grow and replicate to produce more mutated cells. Apoptosis thereby helps protect and insure the survival of the organism. Scientists now report that a dying Drosophila melanogaster larvae cell alerts neighboring cells that they are in danger of suffering a similar fate.

Natural plant compounds may assist chemotherapy

Posted: 27 Mar 2014 07:15 AM PDT

Plant compounds present in carrots and parsley may one day support more effective delivery of chemotherapy treatments, new research has found. Specific plant compounds are able to inhibit transport mechanisms in the body that select what compounds are absorbed into the body, and eventually into cells. These same transport mechanisms are known to interfere with cancer chemotherapy treatment.

Immunotherapy approach to Alzheimer's studied in fly models

Posted: 27 Mar 2014 07:15 AM PDT

The results of using fly models to investigate passive immunotherapy to block amyloid-²42 peptides of amyloid plaques that damage the brain cells of patients with Alzheimer's disease (AD) are now presented by researchers. The scientists are investigating passive immunotherapy, one of the most promising approaches to blocking the amyloid-β42 (Aβ42) peptide, the main component of the amyloid plaques that damage the brain cells of patients with AD.

Caffeinated fruit flies help identify potential genes affecting insecticide resistance

Posted: 27 Mar 2014 07:14 AM PDT

To understand genetic mechanisms underlying insecticide resistance, scientists employed fruit flies and caffeine, a stimulant surrogate for xenobiotics in lab studies on resistance. Crop pests are capable of outwitting the chemical compounds known as xenobiotics that are devised to kill them. This development of resistance to insecticides is a serious problem because it threatens crop production and thereby can influence the availability and costs of many foods as well as the economy.

Inherited muscle diseases: 'Sunday driver' gene headed the wrong way

Posted: 27 Mar 2014 07:14 AM PDT

Skeletal muscle cells with unevenly spaced nuclei, or nuclei in the wrong location, are telltale signs of inherited muscle diseases. Scientists now report on findings from research to determine what goes wrong during myogenesis, the formation and maintenance of muscle tissue, to produce these inherited muscle diseases.

DNA provides information on origins of yeast, helps evolutionaly biologists

Posted: 27 Mar 2014 07:14 AM PDT

A problem in evolutionary biology has been turned into a new tool to better understand phylogeny in closely related species. Resequencing ribosomal DNA in closely related yeast species has given them new information about the origins of modern yeast strains and a useful tool for evolutionary biologists.

Smoke-free air policies seem to protect the heart

Posted: 27 Mar 2014 07:08 AM PDT

Policies prohibiting tobacco smoking in workplaces and other public spaces may substantially improve public health by reducing heart disease and death, according to a new study on the impact of Michigan's statewide smoking ban. In their study, researchers found a statistically significant reduction in cardiovascular disease and death with related hospitalizations decreasing by 2.03 percent from 65,329 to 64,002.

Drug strengthens analgesic effect of opioids without increasing constipation

Posted: 27 Mar 2014 07:06 AM PDT

Scientists have developed a new drug that multiplies the analgesic effect of opioids (drugs for treating intense pain), without increasing constipation, one of the most common side-effects of these drugs, among which is morphine.

Ultra-thin light detectors: Metamaterials and quantum cascade structures combined for first time

Posted: 27 Mar 2014 07:06 AM PDT

A new, extremely thin kind of light detectors has been developed. Two very different technologies were combined for the first time: metamaterials and quantum cascade structures. Subtle interactions of electrons and light make them so valuable for technology: ultra-thin systems of semiconductor layers can turn electrical voltage into light. But they can also be used the other way around and serve as light detectors.

Data mining disaster: Computer technology can mine data from social media during disasters

Posted: 27 Mar 2014 07:06 AM PDT

Computer technology that can mine data from social media during times of natural or other disaster could provide invaluable insights for rescue workers and decision makers, according to scientists.

Record quantum entanglement of multiple dimensions: Two Schrödinger cats which could be alive, dead, or in 101 other states simultaneously

Posted: 27 Mar 2014 07:06 AM PDT

Scienitists have managed to create an entanglement of 103 dimensions with only two photons. The record had been established at 11 dimensions. The discovery could represent a great advance toward the construction of quantum computers with much higher processing speeds than current ones, and toward a better encryption of information.

Computing with slime: Logical circuits built using living slime molds

Posted: 27 Mar 2014 07:03 AM PDT

A future computer might be a lot slimier than the solid silicon devices we have today. Researchers have revealed details of logic units built using living slime molds, which might act as the building blocks for computing devices and sensors.

One gene, many tissues

Posted: 27 Mar 2014 07:03 AM PDT

Genes are the "code" for building the biological elements that form an organism. The DNA that makes up genes contains the instructions to synthesize proteins, but it's wrong to think that, for a given gene, these instructions are always the same for all parts of the organisms. In actual fact, the gene varies depending on the tissue where it is located (cerebral cortex, cerebellum, olfactory epithelium, etc.); in particular, what varies is the point in the "string" of code at which protein synthesis starts.

In mapping feat, scientists pinpoint neurons where select memories grow

Posted: 27 Mar 2014 07:01 AM PDT

Memories are difficult to produce, often fragile, and dependent on any number of factors -- including changes to various types of nerves. In the common fruit fly -- a scientific doppelganger used to study human memory formation—these changes take place in multiple parts of the insect brain. Scientists have now been able to pinpoint a handful of neurons where certain types of memory formation occur.

Gen X obesity a major problem for healthcare, workforce

Posted: 27 Mar 2014 06:59 AM PDT

If current trends continue, Australia's Generation X will overtake Baby Boomers for poor health, including rates of obesity and diabetes, which could have huge implications for healthcare and the workforce. Researchers compared the health status of Baby Boomers (born from 1946-1965) and Generation X (1966-1980) at the same age range of 25-44 years and found that Generation X had significantly poorer levels of self-rated health, and higher levels of obesity and diabetes compared with Boomers, with no real difference in physical activity between the two groups.

Mass participation experiment reveals how to create the perfect dream

Posted: 26 Mar 2014 06:27 PM PDT

Psychologists have announced the results of a two-year study into dream control. The experiment shows that it is now possible for people to create their perfect dream, and so wake up feeling especially happy and refreshed. Researchers also discovered that people's dreams were especially bizarre around the time of a full moon.

Targeting enforcement where needed most in Africa's heart of biodiversity

Posted: 26 Mar 2014 03:22 PM PDT

Scientists seeking a more efficient way of protecting the heart of Africa's wildlife -- the Greater Virunga Landscape -- have developed a method to make the most of limited enforcement resources, according to a new study.

Indian rhinoceroses: Reproductive tract tumors reduce female fertility in early stages

Posted: 26 Mar 2014 03:19 PM PDT

Reproduction of the Indian rhinoceros faces greater difficulties than was previously recognized. Researchers discovered that benign vaginal and cervical tumors cause infertility even in young females. This substantially affects breeding success in zoological gardens.

Some breast cancer tumors hijack patient epigenetic machinery to evade drug therapy

Posted: 26 Mar 2014 12:37 PM PDT

A breast cancer therapy that blocks estrogen synthesis to activate cancer-killing genes sometimes loses its effectiveness because the cancer takes over epigenetic mechanisms, including permanent DNA modifications in the patient's tumor, once again allowing tumor growth, according to an international team of scientists.

Natural history must reclaim its place, experts say

Posted: 26 Mar 2014 11:23 AM PDT

Scientists argue that the study of natural history has waned in recent decades in developed countries. Declining course requirements and support for herbaria are among the documented evidence. Yet costly mistakes in policy relating to natural resources, agriculture, and health might have been avoided by paying attention to organisms' natural history, and future policies will be improved if natural history knowledge is used and expanded. New technologies offer ways to increase natural history research partnerships.

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