Παρασκευή 18 Απριλίου 2014

ScienceDaily: Top News

ScienceDaily: Top News


More, bigger wildfires burning western US over last 30 years

Posted: 17 Apr 2014 12:12 PM PDT

Wildfires across the western United States have been getting bigger and more frequent over the last 30 years. The total area these fires burned increased at a rate of nearly 90,000 acres a year -- an area the size of Las Vegas, according to the study. Individually, the largest wildfires grew at a rate of 350 acres a year, the new research says.

Fish consumption advisories for expecting mothers fail to cover all types of contaminants

Posted: 17 Apr 2014 11:19 AM PDT

Fish consumption advisories for expecting mothers are ineffective in reducing infant exposure to contaminants like persistent organic pollutants. The researchers' model estimates that women who stop eating fish shortly before or during their pregnancy may only lower their child's exposure to POPs by 10 to 15 per cent.

First potentially habitable Earth-sized planet confirmed by Gemini and Keck observatories

Posted: 17 Apr 2014 11:19 AM PDT

The first Earth-sized exoplanet orbiting within the habitable zone of another star has been confirmed by observations with both the W. M. Keck Observatory and the Gemini Observatory. The initial discovery, made by NASA's Kepler Space Telescope, is one of a handful of smaller planets found by Kepler and verified using large ground-based telescopes. It also confirms that Earth-sized planets do exist in the habitable zone of other stars.

Thinnest membrane feasible has been produced

Posted: 17 Apr 2014 11:19 AM PDT

A new nano-membrane made out of the 'super material' graphene is extremely light and breathable. Not only can this open the door to a new generation of functional waterproof clothing, but also to ultra-rapid filtration. The new membrane just produced is as thin as is technologically possible.

Connecting sleep deficits among young fruit flies to disruption in mating later in life

Posted: 17 Apr 2014 11:19 AM PDT

Mom always said you need your sleep, and it turns out, she was right. According to a new study, the lack of sleep in young fruit flies profoundly diminishes their ability to do one thing they do really, really well -- make more flies. To address whether sleep loss in young flies affects development of courtship circuits, the team investigated a group of neurons implicated in courtship. One particular subset of those neurons was smaller in sleep-deprived animals than normal flies, suggesting a possible mechanism for how sleep deprivation can lead to altered courting behavior.

Boosting Depression-Causing Mechanisms in Brain Increases Resilience, Surprisingly

Posted: 17 Apr 2014 11:18 AM PDT

New research uncovers a conceptually novel approach to treating depression. Instead of dampening neuron firing found with stress-induced depression, researchers demonstrated for the first time that further activating these neurons opens a new avenue to mimic and promote natural resilience.

New cause of brain bleeding immediately after stroke identified

Posted: 17 Apr 2014 09:47 AM PDT

By discovering a new mechanism that allows blood to enter the brain immediately after a stroke, researchers have opened the door to new therapies that may limit or prevent stroke-induced brain damage. A complex and devastating neurological condition, stroke is the fourth-leading cause of death and primary reason for disability in the U.S. The blood-brain barrier is severely damaged in a stroke and lets blood-borne material into the brain, causing the permanent deficits in movement and cognition seen in stroke patients.

Proper stem cell function requires hydrogen sulfide

Posted: 17 Apr 2014 09:47 AM PDT

Stem cells in bone marrow need to produce hydrogen sulfide in order to properly multiply and form bone tissue, according to a new study. Researchers demonstrated that mice's osteoporosis-like condition could be rescued by administering small molecules that release hydrogen sulfide inside the body. The results indicate that a similar treatment may have potential to help human patients.

Surprising material could play huge role in saving energy: Tin selenide is best at converting waste heat to electricity

Posted: 17 Apr 2014 09:45 AM PDT

One strategy for addressing the world's energy crisis is to stop wasting so much energy when producing and using it, such as in coal-fired power plants or transportation. Nearly two-thirds of energy input is lost as waste heat. Now scientists have discovered a surprising material that is the best in the world at converting waste heat to useful electricity. This outstanding property could be exploited in solid-state thermoelectric devices, with potentially enormous energy savings.

Fear of the cuckoo mafia: In fear of retaliation, birds accept and raise brood parasites' young

Posted: 17 Apr 2014 09:45 AM PDT

If a restaurant owner fails to pay the 'protection money' demanded of him by the mob, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to make restaurant owners pay up. Similarly, mafia-like behavior is observed in parasitic birds, which lay their eggs in other birds' nests. If the host birds throw the cuckoo's egg out, the brood parasites take their revenge by destroying the entire nest. Consequently, it is beneficial for hosts to be capable of learning and to cooperate. Previously seen only in field observations, scientists have now modeled this behavior mathematically to confirm it as an effective strategy.

A cross-section of the universe

Posted: 17 Apr 2014 09:44 AM PDT

An image of a galaxy cluster gives a remarkable cross-section of the universe, showing objects at different distances and stages in cosmic history. They range from cosmic near neighbors to objects seen in the early years of the universe. The 14-hour exposure shows objects around a billion times fainter than can be seen with the naked eye.

Discovery could lead to novel therapies for Fragile X syndrome

Posted: 17 Apr 2014 09:43 AM PDT

Scientists studying the most common form of inherited mental disability -- a genetic disease called 'Fragile X syndrome' -- have uncovered new details about the cellular processes responsible for the condition that could lead to the development of therapies to restore some of the capabilities lost in affected individuals.

For resetting circadian rhythms, neural cooperation is key

Posted: 17 Apr 2014 09:43 AM PDT

Fruit flies are pretty predictable when it comes to scheduling their days, with peaks of activity at dawn and dusk and rest times in between. Now, researchers have found that the clusters of brain cells responsible for each of those activity peaks -- known as the morning and evening oscillators, respectively -- don't work alone. For flies' internal clocks to follow the sun, cooperation is key.

Fighting malaria drug resistance: Scientists find new way

Posted: 17 Apr 2014 07:15 AM PDT

An anti-malarial treatment that lost its status as the leading weapon against the deadly disease could be given a new lease of life, with new research indicating it simply needs to be administered differently. The findings could revive the use of the cheap anti-malarial drug chloroquine in treating and preventing the mosquito-bourne disease, which claims the lives of more than half a million people each year around the world.

Some immune cells defend only one organ

Posted: 17 Apr 2014 07:14 AM PDT

Some organs have the immunological equivalent of 'neighborhood police' -- specialized squads of defenders that patrol only one area, a single organ, instead of an entire city, the body, scientists have discovered. The liver, skin and uterus each has dedicated immune cells, which the researchers call tissue-resident natural killer cells. Other organs may have similar arrangements.

Biologists help solve fungal mysteries, inform studies on climate change

Posted: 17 Apr 2014 07:14 AM PDT

A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate change. Huge populations of fungi are churning away in the soil in pine forests, decomposing organic matter and releasing carbon into the atmosphere.

Radiation therapy for cervical cancer increases risk for colorectal cancer

Posted: 17 Apr 2014 07:14 AM PDT

Young women treated with radiation for cervical cancer should begin colorectal cancer screening earlier than traditionally recommended, researchers are recommending for the first time. After finding a high incidence of secondary colorectal cancers among cervical cancer survivors treated with radiation, these researchers off new recommendations that the younger women in this group begin colorectal cancer screening about eight years after their initial cervical cancer diagnosis.

Methane climate change risk suggested by proof of redox cycling of humic substances

Posted: 17 Apr 2014 07:11 AM PDT

Disruption of natural methane-binding process may worsen climate change, scientists have suggested, painting a stark warning on the possible effects of gases such as methane -- which has a greenhouse effect 32 times that of carbon dioxide. Researchers have shown that humic substances act as fully regenerable electron acceptors which helps explain why large amount of methane are held in wetlands instead of being released to the atmosphere.

In sex-reversed cave insects, females have the penises

Posted: 17 Apr 2014 07:11 AM PDT

Little-known cave insects with rather novel sex lives have been discovered by researchers. The Brazilian insects, which represent four distinct but related species in the genus Neotrogla, are the first example of an animal with sex-reversed genitalia.

'I spy' used to show spoken language helps direct children's eyes

Posted: 17 Apr 2014 06:08 AM PDT

Children spot objects more quickly when prompted by words than if they are only prompted by images, cognitive scientists have demonstrated. Spoken language taps into children's cognitive system, enhancing their ability to learn and to navigate cluttered environments. As such the study opens up new avenues for research into the way language might shape the course of developmental disabilities such as ADHD, difficulties with school, and other attention-related problems.

Rapid, accurate mRNA detection in plant tissues

Posted: 17 Apr 2014 06:08 AM PDT

Messenger RNA (mRNA) plays an important role in gene expression, and examining the types and amounts of mRNA present in an organism allows researchers to answer key questions about gene expression and regulation. A recent study shows that RNAScope ISH (developed for studies in animal -- particularly human -- tissues) is faster and more sensitive than traditional ISH in detecting and quantifying mRNA in plants.

New technique detects microscopic diabetes-related eye damage

Posted: 17 Apr 2014 06:08 AM PDT

New early-warning signs of the potential loss of sight associated with diabetes have been detected by researchers. This discovery could have far-reaching implications for the diagnosis and treatment of diabetic retinopathy, potentially impacting the care of over 25 million Americans. These important early-warning signs were invisible to existing diagnostic techniques, requiring new technology based on adaptive optics.

Study shows lasting effects of drought in rainy Eastern U.S.

Posted: 17 Apr 2014 06:08 AM PDT

This spring, more than 40 percent of the western U.S. is in a drought that the USDA deems "severe" or "exceptional." The same was true in 2013. In 2012, drought even spread to the humid east. But new research shows how short-lived but severe climatic events can trigger cascades of ecosystem change that last for centuries.

Study finds adverse respiratory outcomes for older people with COPD taking benzodiazepines

Posted: 17 Apr 2014 06:08 AM PDT

A group of drugs commonly prescribed for insomnia, anxiety and breathing issues 'significantly increase the risk' that older people with chronic obstructive pulmonary disease, or COPD, need to visit a doctor or emergency department for respiratory reasons, new research has found. Benzodiazepines, such as Ativan or Xanax, may actually contribute to respiratory problems, such as depressing breathing ability and pneumonia, in these patients.

The story of animal domestication retold: Scientists now think wild animals interbred with domesticated ones until quite recently

Posted: 17 Apr 2014 06:08 AM PDT

A review of recent research on the domestication of large herbivores suggests that neither intentional breeding nor genetic isolation were as significant as traditionally thought. "Our findings show little control of breeding, particularly of domestic females, and indicate long-term gene flow, or interbreeding, between managed and wild animal populations," a co-author said.

Genetic study tackles mystery of slow plant domestications

Posted: 17 Apr 2014 06:08 AM PDT

Did domesticating a plant typically take a few hundred or many thousands of years? Genetic studies often indicate that domestication traits have a fairly simple genetic basis, which should facilitate their rapid evolution under selection. On the other hand, recent archeological studies of crop domestication have suggested a relatively slow spread and fixation of domestication traits. A new article tries to resolve the discrepancy.

Key milestone for brown fat research with ground-breaking MRI scan

Posted: 17 Apr 2014 06:08 AM PDT

The first MRI scan to show 'brown fat' in a living adult could prove to be an essential step towards a new wave of therapies to aid the fight against diabetes and obesity. Brown fat has become a hot topic for scientists due its ability to use energy and burn calories, helping to keep weight in check. Understanding the brown fat tissue and how it can be used to such ends is of growing interest in the search to help people suffering from obesity or at a high risk of developing diabetes.

HIV and schistosomiasis coinfection in African children: More research needed

Posted: 17 Apr 2014 06:07 AM PDT

More research is needed on HIV and schistosomiasis coinfection in children in sub-Saharan Africa, experts say. They looked at previous research into the joint burden of HIV/AIDS and schistosomiasis of children, and found that while disease-specific control interventions are continuing, potential synergies in the control efforts for the two diseases have not been investigated. The team focused on children with schistosomiasis and assessed the risk of increased HIV transmission and progression and impaired response to drugs when given alongside HIV interventions.

'Brain training' overcomes tics in Tourette syndrome, study finds

Posted: 17 Apr 2014 06:05 AM PDT

Children with Tourette Syndrome (TS) may unconsciously train their brain to more effectively control their tics. Teenagers diagnosed with Tourette Syndrome (TS) were slower than their typically developing peers when asked to perform a task that involved them simply moving their eyes to look at targets. However, they significantly outperformed their peers when the task was more demanding and required them to choose between looking at or away from targets. In this task they were as fast as their peers but made fewer eye movements in the wrong direction.

Chiral breathing: Electrically controlled polymer changes its optical properties

Posted: 17 Apr 2014 06:05 AM PDT

Electrically controlled glasses with continuously adjustable transparency, new polarization filters, and even chemosensors capable of detecting single molecules of specific chemicals could be fabricated thanks to a new polymer unprecedentedly combining optical and electrical properties.

New city wall discovered at ancient Roman port

Posted: 17 Apr 2014 06:05 AM PDT

Researchers have discovered a new section of the boundary wall of the ancient Roman port of Ostia, proving the city was much larger than previously estimated.

New MRSA superbug emerges in Brazil

Posted: 17 Apr 2014 05:55 AM PDT

A new superbug that caused a bloodstream infection in a Brazilian patient has been identified by an international research team. The new superbug is part of a class of highly-resistant bacteria known as methicillin-resistant Staphylococcus aureus or MRSA, which is a major cause of hospital and community-associated infections. The superbug has also acquired high levels of resistance to vancomycin, the most common and least expensive antibiotic used to treat severe MRSA infections worldwide.

Simplicity is key to co-operative robots

Posted: 16 Apr 2014 07:53 PM PDT

A way of making hundreds -- or even thousands -- of tiny robots cluster to carry out tasks without using any memory or processing power has been developed. Engineers have programmed extremely simple robots that are able to form a dense cluster without the need for complex computation, in a similar way to how a swarm of bees or a flock of birds is able to carry out tasks collectively.

Chess robots to cause Judgment Day?

Posted: 16 Apr 2014 07:53 PM PDT

Next time you play a computer at chess, think about the implications if you beat it. It could be a very sore loser! A new study reflects upon the growing need for autonomous technology, and suggests that humans should be very careful to prevent future systems from developing anti-social and potentially harmful behavior.

Changing where a baby is held immediately after birth could lead to improved uptake of procedure that reduces infant iron deficiency

Posted: 16 Apr 2014 04:09 PM PDT

Changing where a newborn baby is held before its umbilical cord is clamped could lead to improved uptake in hospitals of delayed cord clamping, leading to a decreased risk of iron deficiency in infancy, according to new results from a study. Delaying clamping of the umbilical cord until around two minutes after birth allows for blood to pass from the mother's placenta to the baby, and has previously been shown to reduce the risk of iron deficiency in infancy.

At least one in 20 adult outpatients misdiagnosed in U.S. every year

Posted: 16 Apr 2014 04:09 PM PDT

At least one in 20 adults is misdiagnosed in outpatient clinics in the U.S. every year, amounting to 12 million people nationwide, and posing a 'substantial patient safety risk,' finds research. Half of these errors could be potentially harmful, say the authors, who add that their findings should prompt renewed efforts to monitor and curb the numbers of misdiagnoses.

Bacteria survive longer in contact lens cleaning solution than previously thought, study shows

Posted: 16 Apr 2014 04:09 PM PDT

Each year in the UK, bacterial infections cause around 6,000 cases of a severe eye condition known as microbial keratitis – an inflammation and ulceration of the cornea that can lead to loss of vision. The use of contact lenses has been identified as a particular risk factor for microbial keratitis. New research shows that a bacterial strain associated with more severe infections shows enhanced resistance to a common contact lens disinfectant solution.

Declining catch rates in Caribbean Nicaragua green turtle fishery may be result of overfishing

Posted: 16 Apr 2014 04:09 PM PDT

A 20-year assessment of Nicaragua's legal, artisanal green sea turtle fishery has uncovered a stark reality: greatly reduced overall catch rates of turtles in what may have become an unsustainable take, according to conservation scientists. Growing up to 400 pounds in weight, the green turtle is the second largest sea turtle species next to the leatherback turtle. In addition to the threat from overfishing, the green turtle is at risk from bycatch in various fisheries, poaching of eggs at nesting beaches, habitat deterioration and loss due to coastal development and climate change effects, and pollution.

Atypical brain connectivity associated with autism spectrum disorder

Posted: 16 Apr 2014 02:23 PM PDT

Autism spectrum disorder in adolescents appears to be associated with atypical connectivity in the brain involving the systems that help people infer what others are thinking and understand the meaning of others' actions and emotions. The ability to navigate and thrive in complex social systems is commonly impaired in ASD, a neurodevelopmental disorder affecting as many as 1 in 88 children.

Family ties in the language jungle: Amazon language relationships revealed

Posted: 16 Apr 2014 02:22 PM PDT

Relationships between rare languages in the Colombian Amazon have been revealed by researchers. The only linguistic data available for Carabayo, a language spoken by an indigenous group that lives in voluntary isolation, is a set of about 50 words. This list was compiled in 1969 during a brief encounter with one Carabayo family. Researchers have now analyzed this historical data set and compared it with various languages (once) spoken in the region. The analysis showed that Carabayo shares a number of similarities with the extinct language Yurí and with Tikuna, a language still spoken in the region nowadays.

Surprising consequences of banning chocolate milk

Posted: 16 Apr 2014 02:22 PM PDT

Eliminating chocolate milk from elementary schools decreased total milk sales by 10 percent, and increased milk waste by 29 percent, a study has shown. Additionally, the ban may have been a factor in a 7 percent decrease in Lunch Program participation. Nutritionally, after the milk substitution, students on average consumed less sugar and fewer calories, but also consumed less protein and calcium.

Chimpanzees prefer firm, stable beds

Posted: 16 Apr 2014 02:22 PM PDT

Chimpanzees may select a certain type of wood, Ugandan ironwood, over other options for its firm, stable, and resilient properties to make their bed. Chimpanzees use tree branches to build beds or nests in trees. They select certain tree species to sleep in more frequently than others, but the reason for selecting a particular tree was unclear.

Beating the clock for ischemic stroke sufferers

Posted: 16 Apr 2014 02:20 PM PDT

Researchers have developed a new computer tool to ensure faster care and treatment for stroke patients. The CAD stroke technology is capable of detecting signs of stroke from computed tomography (CT) scans. A CT scan uses X-rays to take pictures of the brain in slices. When blood flow to the brain is blocked, an area of the brain turns softer or decreases in density due to insufficient blood flow, pointing to an ischemic stroke.

Residing in high altitude military facilities protects service members from obesity

Posted: 16 Apr 2014 02:19 PM PDT

Overweight U.S. service members are 41 percent less likely to transition to clinical obesity when stationed at military facilities located at high altitude, according to a new study. The quasi-experimental, retrospective study assessed the health records and migration patterns of nearly 100,000 enlisted service members in the active component of the U.S. Army and Air Force with at least two years in the services from records in the Defense Medical Surveillance System.

Immune system research may help predict who gets long-term complications from Lyme Disease

Posted: 16 Apr 2014 02:19 PM PDT

The groundwork has been laid for understanding how variations in immune responses to Lyme disease can contribute to the many different outcomes of this bacterial infection seen in individual patients. "Physicians have recognized for many years that Lyme disease is not a uniform disease process and can vary in outcomes," says the senior author of the report. "Our experiments have linked such differences to specific immune pathways controlled by elements of the immune system, which in turn might help us understand both the good immune processes that clear up the infection and the bad ones that cause injury and prolong symptoms. This could be a big step forward in managing this disease."

In old age, lack of emotion, interest may signal brain is shrinking

Posted: 16 Apr 2014 01:24 PM PDT

Older people who have apathy but not depression may have smaller brain volumes than those without apathy, according to a new study. Apathy is a lack of interest or emotion.

How intestinal cells build nutrient-absorbing surface

Posted: 16 Apr 2014 11:33 AM PDT

The 'brush border' -- a densely packed array of finger-like projections called microvilli -- covers the surfaces of the cells that line our intestines. Researchers have now discovered how intestinal cells build this specialized structure, which is critical for absorbing nutrients and defending against pathogens. The findings reveal a role for adhesion molecules in brush border assembly and increase our understanding of intestinal pathologies associated with inherited and infectious diseases.

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