Παρασκευή 31 Αυγούστου 2012

ScienceDaily: Latest Science News

ScienceDaily: Latest Science News


NASA's Jupiter-bound Juno changes its orbit

Posted: 30 Aug 2012 05:28 PM PDT

Earlier today, navigators and mission controllers for NASA's Juno mission to Jupiter watched their computer screens as their spacecraft successfully performed its first deep-space maneuver. This first firing of Juno's main engine is one of two planned to refine the spacecraft's trajectory, setting the stage for a gravity assist from a flyby of Earth on Oct 9, 2013. Juno will arrive at Jupiter on July 4, 2016.

Healthy living into old age can add up to six years to your life: Keeping physically active shows strongest association with survival

Posted: 30 Aug 2012 04:10 PM PDT

Living a healthy lifestyle into old age can add five years to women's lives and six years to men's, finds a new study.

Domestic coal use linked to substantial lifetime risk of lung cancer in Xuanwei, China

Posted: 30 Aug 2012 04:10 PM PDT

The use of "smoky coal" for household cooking and heating is associated with a substantial increase in the lifetime risk of developing lung cancer, finds a study from China.

Shading Earth: Delivering solar geoengineering materials to combat global warming may be feasible and affordable

Posted: 30 Aug 2012 04:10 PM PDT

A cost analysis of the technologies needed to transport materials into the stratosphere to reduce the amount of sunlight hitting Earth and therefore reduce the effects of global climate change has shown that they are both feasible and affordable. The study has shown that the basic technology currently exists and could be assembled and implemented in a number of different forms for less than USD $5 billion a year.

Mystery of operon evolution probed

Posted: 30 Aug 2012 02:35 PM PDT

New research suggests a possible explanation for the organization of operons, jointly controlled clusters of genes that evolved in bacterial chromosomes. Operons, which are found in the chromosomes of bacteria but not in more advanced organisms, have puzzled biologists since their discovery in the 1960s. The new study suggests operons evolved as a means of reducing "noise" in biochemical signal processing.

Biophysicists unravel secrets of genetic switch

Posted: 30 Aug 2012 02:33 PM PDT

Biophysicists have experimentally demonstrated, for the first time, how the nonspecific binding of a protein known as the lambda repressor, or C1 protein, bends DNA and helps it close a loop that switches off virulence. Findings are the first direct and quantitative determination of non-specific binding and compaction of DNA, relevant for the understanding of DNA physiology, and the dynamic characteristics of an on-off switch for the expression of genes.

'Nanoresonators' might improve cell phone performance

Posted: 30 Aug 2012 02:33 PM PDT

Researchers have learned how to mass produce tiny mechanical devices that could help cell phone users avoid the nuisance of dropped calls and slow downloads. The devices are designed to ease congestion over the airwaves to improve the performance of cell phones and other portable devices.

Photonic interactions measured at atomic level

Posted: 30 Aug 2012 02:33 PM PDT

By measuring the unique properties of light on the scale of a single atom, researchers believe that they have characterized the limits of metal's ability in devices that enhance light.

Surviving drought: Discovery may help protect crops from stressors

Posted: 30 Aug 2012 02:31 PM PDT

New findings of a key genetic mechanism in plant hormone signaling may help save crops from stress and help address human hunger.

Antibody prevents hepatitis C infection in animal model

Posted: 30 Aug 2012 02:31 PM PDT

A monoclonal antibody tested in an animal model prevents infection by the hepatitis C virus (HCV).

Urinary protein excretion -- even in the normal range -- raises diabetics' heart risks, study finds

Posted: 30 Aug 2012 02:31 PM PDT

For patients with type 2 diabetes, any degree of measurable urinary protein excretion —- even in what is considered the normal range —- increases their risk of experiencing heart problems, according to a new study. More than 300 million people worldwide have type 2 diabetes.

Microbes help hyenas communicate via scent

Posted: 30 Aug 2012 12:23 PM PDT

Bacteria in hyenas' scent glands may be the key controllers of communication. New research shows a clear relationship between the diversity of hyena clans and the distinct microbial communities that reside in their scent glands.

'Promiscuous' enzymes still prevalent in metabolism: Challenges fundamental notion of enzyme specificity and efficiency

Posted: 30 Aug 2012 12:23 PM PDT

Open an undergraduate biochemistry textbook and you will learn that enzymes are highly efficient and specific in catalyzing chemical reactions in living organisms, and that they evolved to this state from their "sloppy" and "promiscuous" ancestors to allow cells to grow more efficiently. This fundamental paradigm is being challenged in a new study by bioengineers who reported in the journal Science what a few enzymologists have suspected for years: many enzymes are still pretty sloppy and promiscuous, catalyzing multiple chemical reactions in living cells, for reasons that were previously not well understood.

Moving toward regeneration

Posted: 30 Aug 2012 12:23 PM PDT

Scientists have shown how pluripotent stem cells mobilize in wounded planarian worms, to better understand stem cell behavior in regeneration and disease.

NASA's Dawn spacecraft prepares for trek toward dwarf planet

Posted: 30 Aug 2012 11:18 AM PDT

NASA's Dawn spacecraft is on track to become the first probe to orbit and study two distant solar system destinations, to help scientists answer questions about the formation of our solar system. The spacecraft is scheduled to leave the giant asteroid Vesta on Sept. 4 PDT (Sept. 5 EDT) to start its two-and-a-half-year journey to the dwarf planet Ceres.

Monogamy and the immune system: Differences in sexual behavior impact bacteria hosted and genes that control immunity

Posted: 30 Aug 2012 11:14 AM PDT

Researchers examined the differences between two species of mice -- one monogamous and one promiscuous -- on a microscopic and molecular level. They discovered that the lifestyles of the two mice had a direct impact on the bacterial communities that reside within the female reproductive tract. These differences correlate with enhanced diversifying selection on genes related to immunity against bacterial diseases.

Plants' fungi allies may not help store climate change's extra carbon

Posted: 30 Aug 2012 11:13 AM PDT

Fungi found in plants may not be the answer to mitigating climate change by storing additional carbon in soils as some previously thought, according to plant biologists.

Human and soil bacteria swap antibiotic-resistance genes

Posted: 30 Aug 2012 11:13 AM PDT

Soil bacteria and bacteria that cause human diseases have recently swapped at least seven antibiotic-resistance genes, researchers at Washington University School of Medicine in St. Louis report Aug. 31 in Science.

'Weird chemistry' by microbe is prime source of ocean methane

Posted: 30 Aug 2012 11:13 AM PDT

Up to four percent of the methane on Earth comes from the ocean's oxygen-rich waters, but scientists have been unable to identify the source of this potent greenhouse gas. Now researchers report that they have found the culprit: A bit of "weird chemistry" practiced by the most abundant microbes on the planet.

Heating by black carbon aerosol: Soot particles absorb significantly less sunlight than predicted by models

Posted: 30 Aug 2012 11:13 AM PDT

Black carbon, in the form of soot particles, has been ranked just behind carbon dioxide for its role in warming regional and global climates. But a new study finds airborne black carbon absorbs significantly less sunlight than scientists had predicted, leading an international team of researchers to reconsider the impact of soot on atmospheric warming.

Cancer gene family member functions key to cell adhesion and migration

Posted: 30 Aug 2012 11:13 AM PDT

Scientists have used sophisticated technologies to identify and describe the protein interactions that distinguish each member of the WTX family. They found that unlike WTX and FAM123C, FAM123A interacts with a specific set of proteins that regulates cell adhesion and migration, processes essential to normal cell functioning and which, when mutated, contribute to human diseases such as cancer or Alzheimer's.

Evolution of mustards' spice: Plants developed chemical defense against bugs, specific to where they live

Posted: 30 Aug 2012 11:13 AM PDT

The tangy taste a mustard plant develops to discourage insect predators can be the difference between life and death for the plants. A new study has used this trait and its regional variations to conquer the difficult task of measuring the evolution of complex traits in a natural environment.

Ancient Denisovan genome: Relationships between Denisovans and present-day humans revealed

Posted: 30 Aug 2012 11:12 AM PDT

Researchers have described the Denisovan genome, illuminating the relationships between Denisovans and present-day humans.

Uncoiling the cucumber's enigma: Biological mechanism for coiling, and unusual type of spring discovered

Posted: 30 Aug 2012 11:12 AM PDT

In the creeping plant's tendrils, researchers discover a biological mechanism for coiling and stumble upon an unusual type of spring.

Leaders' emotional cues may predict acts of terror or political aggression

Posted: 30 Aug 2012 10:53 AM PDT

Leaders often use rousing speeches to evoke powerful emotions, and those emotions may predict when a group will commit an act of violence or terrorism, according to new research. Analysis of speeches delivered by government, activist and terrorist leaders found that leaders' expressions of anger, contempt and disgust spiked immediately before their group committed an act of violence.

Chemical exposure in the womb from household items may contribute to obesity

Posted: 30 Aug 2012 10:53 AM PDT

Pregnant women who are highly exposed to common environmental chemicals -- polyfluoroalkyl compounds (PFCs) -- have babies that are smaller at birth and larger at 20 months of age, according to a new study. PFCs are used in the production of fluoropolymers and are found widely in protective coatings of packaging products, clothes, furniture and non-stick cookware. They are persistent compounds found abundantly in the environment and human exposure is common. PFCs have been detected in human sera, breast milk and cord blood.

Overwhelmed by instant access to news and information? Most Americans like it

Posted: 30 Aug 2012 10:53 AM PDT

"Information overload" may be an exaggerated way to describe today's always-on media environment. Actually, very few Americans seem to feel bogged down or overwhelmed by the volume of news and information at their fingertips and on their screens, according to a new study.

People merge supernatural and scientific beliefs when reasoning with the unknown, study shows

Posted: 30 Aug 2012 10:53 AM PDT

A new psychology study finds adults are more likely than children to find supernatural explanations for existential questions.

Lyme retreatment guidance may be flawed

Posted: 30 Aug 2012 10:53 AM PDT

A new statistical review calls into question studies that have been taken as proof that antibiotic retreatment for chronic Lyme disease is futile. That misunderstanding has led to medical guidance that discourages retreatment and insurance coverage for it. Instead, the authors of the review suggest, the proper reading of the studies and their data is that they prove nothing.

Studying everyday eye movements could aid in diagnosis of neurological disorders

Posted: 30 Aug 2012 10:53 AM PDT

Researchers have devised a method for detecting certain neurological disorders through the study of eye movements.

Early activation of immune response could lead to better vaccines

Posted: 30 Aug 2012 10:51 AM PDT

Researchers have discovered a new "first response" mechanism that the immune system uses to respond to infection. The findings challenge the current understanding of immunity and could lead to new strategies for boosting effectiveness of all vaccines.

Potential new approach for improving quality of life for amyotrophic lateral sclerosis patients

Posted: 30 Aug 2012 10:51 AM PDT

Amyotrophic lateral sclerosis, also known as Lou Gehrig's disease or ALS, is a devastating, rapidly advancing disease of the nerve cells in the brain and spinal cord that control voluntary muscle movement. But researchers have identified a new target for slowing the deterioration of physical function for which the disease is so well known.

Potential treatment for cognitive effects of stress-related disorders, including PTSD

Posted: 30 Aug 2012 10:51 AM PDT

Researchers have identified a potential medical treatment for the cognitive effects of stress-related disorders, including post-traumatic stress disorder (PTSD). The study, conducted in a PTSD mouse model, shows that an experimental drug called S107, one of a new class of small-molecule compounds called Rycals, prevented learning and memory deficits associated with stress-related disorders.

Radiation belt storm probes: Spacecraft pair to explore mysterious region where other satellites fear to tread

Posted: 30 Aug 2012 10:05 AM PDT

Spacecraft pair will explore the mysterious region where other satellites fear to tread.

Surprisingly bright superbubble in nearby nebula

Posted: 30 Aug 2012 10:04 AM PDT

A new composite image shows a superbubble in the Large Magellanic Cloud (LMC), a small satellite galaxy of the Milky Way, located about 160,000 light years from Earth. Many new stars, some of them very massive, are forming in the star cluster NGC 1929, which is embedded in the nebula N44.

Diverse metabolic roles for PML tumor suppressor gene

Posted: 30 Aug 2012 10:04 AM PDT

Two articles shed new light on the genetic mechanisms underlying cellular energy and metabolism and, at the same time, highlight both the challenges and opportunities of genetic approaches to cancer treatment.

New flexible electronics technology may lead to new medical uses

Posted: 30 Aug 2012 10:04 AM PDT

Researchers have developed technology that opens new possibilities for health care and medical applications of electronic devices.

Growing strong muscles without working out? 'Hulk' protein, Grb10, controls muscle growth

Posted: 30 Aug 2012 10:04 AM PDT

Scientists may soon help people grow strong muscles without needing to hit the weight room. Researchers discovered that by blocking the function of the protein Grb10 in mice in the womb, they developed as more muscular than their normal counterparts. This presents important implications for a range of conditions that are worsened by, or cause muscle wasting, such as injury, muscular dystrophy, and Type 2 diabetes.

No-till farming helps capture snow and soil water

Posted: 30 Aug 2012 10:04 AM PDT

A smooth blanket of snow in the winter can help boost dryland crop productivity in the summer, and no-till management is one way to ensure that blanket coverage, according to new research.

Viruses could be the key to healthy corals

Posted: 30 Aug 2012 10:04 AM PDT

Scientists have developed a treatment for the white plague disease that infects coral based on a medication developed to treat bacterial infections in humans. The therapy ceased the progression of infection in diseased corals and prevented the infection from spreading to surrounding healthy corals as well.

Does wisdom really come with age? It depends on the culture

Posted: 30 Aug 2012 10:04 AM PDT

It's certainly comforting to think that aging benefits the mind, if not the body. But do we really get wiser with age? Research suggests that having wisdom means includes being good at resolving conflict, but conflict is not handled the same way across cultures. A new study examines how the resolution of conflict and, by extension, wisdom differ between Japanese and American cultures.

Increased sediment and nutrients delivered to bay as Susquehanna reservoirs near sediment capacity

Posted: 30 Aug 2012 10:00 AM PDT

Reservoirs near the mouth of the Susquehanna River just above Chesapeake Bay, Maryland, U.S. are nearly at capacity in their ability to trap sediment. As a result, large storms are already delivering increasingly more suspended sediment and nutrients to the Bay, which may negatively impact restoration efforts.

Shedding new light on one of diabetes' most dangerous complications

Posted: 30 Aug 2012 10:00 AM PDT

For many diabetics, monitoring their condition involves much more than adhering to a routine of glucose sensing and insulin injections. It also entails carefully monitoring the ongoing toll this disease takes on their body. An innovative new optical diagnostic tool may soon make it easier to diagnose and monitor one of the most serious complications of diabetes, peripheral arterial disease (PAD).

Bitter tastes quickly turn milk chocolate fans sour

Posted: 30 Aug 2012 10:00 AM PDT

Dark chocolate lovers can handle a wider range of bitter tastes before rejection compared to milk chocolate fans, according to food scientists.

Millipede family added to Australian fauna

Posted: 30 Aug 2012 10:00 AM PDT

An entire group of millipedes previously unknown in Australia has been discovered by a specialist – on museum shelves. Hundreds of tiny specimens of the widespread tropical family Pyrgodesmidae have been found among bulk samples in two museums, showing that native pyrgodesmids are not only widespread in Australia's tropical and subtropical forests, but are also abundant and diverse. The study has been published in the open access journal ZooKeys.

Coral scientists use new model to find where corals are most likely to survive climate change

Posted: 30 Aug 2012 07:54 AM PDT

Marine conservationists have identified heat-tolerant coral species living in locations with continuous background temperature variability as those having the best chance of surviving climate change, according to a new simplified method for measuring coral reef resilience.

Malaria: Protein impedes microcirculation of malaria-infected red blood cells

Posted: 30 Aug 2012 07:54 AM PDT

A certain protein significantly reduces the malaria-infected cells' ability to squeeze through tiny channels compared to healthy cells.

Early menopause: A genetic mouse model of human primary ovarian insufficiency

Posted: 30 Aug 2012 07:54 AM PDT

Scientists have established a genetic mouse model for primary ovarian insufficiency (POI), a human condition in which women experience irregular menstrual cycles and reduced fertility, and early exposure to estrogen deficiency. POI affects approximately one in a hundred women. In most cases of primary ovarian insufficiency, the cause is mysterious, although genetics is known to play a causative role.

New DNA method tracks fish and whales in seawater

Posted: 30 Aug 2012 07:54 AM PDT

Future monitoring of marine biodiversity and resources may use DNA traces in seawater samples to keep track of fish and whales in the oceans. A half liter of seawater can contain evidence of local fish and whale faunas and combat traditional fishing methods.

Five new species of cuckoo bees from the Cape Verde Islands

Posted: 30 Aug 2012 07:54 AM PDT

Researchers have documented a remarkable diversity of cuckoo bees in the Cape Verde Islands. All five discovered species are entirely new to science and highlight the unique biota of this isolated archipelago.

Carbon release from collapsing coastal permafrost in Arctic Siberia

Posted: 30 Aug 2012 07:53 AM PDT

A new study shows that an ancient and large carbon pool held in a less-studied form of permafrost ("Yedoma") is thaw-released along the approximately 7000-kilometer desolate coast of northernmost Siberian Arctic. 

Factors other than pain affect long-term use of strong pain medications after surgery

Posted: 30 Aug 2012 07:52 AM PDT

Non-pain-related factors—including previous use of pain medications, high perceived risk of addiction, and symptoms of depression—increase the risk of continuing to use strong pain-relieving drugs several months after surgery, according to a new study.

Anesthesia for hand or face transplants -- initial guidelines

Posted: 30 Aug 2012 07:52 AM PDT

Hand and facial transplants are still rare, but experience so far has produced some suggested guidelines for anesthetic management in patients undergoing these complex "composite" transplant procedures, according to a pair of articles.

Keep your distance: Why cells and organelles don't get stuck

Posted: 30 Aug 2012 07:28 AM PDT

Biomembranes enclose biological cells like a skin. They also surround organelles that carry out important functions in metabolism and cell division. Scientists have long known in principle how biomembranes are built up, and also that water molecules play a role in maintaining the optimal distance between neighboring membranes -- otherwise they could not fulfill their vital functions. Now, with the help of computer simulations, scientists have discovered two different mechanisms that prevent neighboring membrane surfaces from sticking together.

Gender bias in leading scientific journals

Posted: 30 Aug 2012 07:28 AM PDT

Fewer women than men are asked to write in the leading scientific journals, new research shows.

Water pipe smoking has the same respiratory effects as smoking cigarettes

Posted: 30 Aug 2012 07:28 AM PDT

Water pipe smoking, such as hookah or bong smoking, affects lung function and respiratory symptoms as much as cigarette smoking, new research shows.

What babies eat after birth likely determines lifetime risk of metabolic mischief and obesity, rat studies suggest

Posted: 30 Aug 2012 07:27 AM PDT

Rats born to mothers fed high-fat diets but who get normal levels of fat in their diets right after birth avoid obesity and its related disorders as adults, according to new research. Meanwhile, rat babies exposed to a normal-fat diet in the womb but nursed by rat mothers on high-fat diets become obese by the time they are weaned.

Calorie Restriction Does Not Affect Survival: Study Of Monkeys Also Suggests Some Health Benefits

Posted: 30 Aug 2012 05:51 AM PDT

Scientists have found that calorie restriction -- a diet composed of approximately 30 percent fewer calories but with the same nutrients of a standard diet -- does not extend years of life or reduce age-related deaths in a 23-year study of rhesus monkeys. However, calorie restriction did extend certain aspects of health.

Conservation scientists call policy-makers to be scale-aware

Posted: 30 Aug 2012 05:33 AM PDT

Conservation is concerned with the preservation of biological diversity at all levels, from genes to species, communities and ecosystems.  Yet conserving this biological richness is made difficult because it varies in complex ways at different scales of space and time. The problem of scale emerges as a critical new theme in conservation practice.

NASA launches radiation belt storm probes mission

Posted: 30 Aug 2012 04:50 AM PDT

NASA's Radiation Belt Storm Probes (RBSP), the first twin-spacecraft mission designed to explore our planet's radiation belts, launched into the predawn skies at 4:05 a.m. EDT Thursday from Cape Canaveral Air Force Station, Fla. The two satellites, each weighing just less than 1,500 pounds, comprise the first dual-spacecraft mission specifically created to investigate this hazardous regions of near-Earth space, known as the radiation belts. These two belts, named for their discoverer, James Van Allen, encircle the planet and are filled with highly charged particles. The belts are affected by solar storms and coronal mass ejections and sometimes swell dramatically. When this occurs, they can pose dangers to communications, GPS satellites and human spaceflight.

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