Παρασκευή 28 Φεβρουαρίου 2014

ScienceDaily: Top Environment News

ScienceDaily: Top Environment News


'Shark's eye' view: Witnessing the life of a top predator

Posted: 27 Feb 2014 11:26 AM PST

Instruments strapped onto and ingested by sharks are revealing novel insights into how one of the most feared and least understood ocean predators swims, eats and lives.

10,000 years on the Bering Land Bridge: Ancestors of Native Americans paused en route from Asia

Posted: 27 Feb 2014 11:18 AM PST

Genetic and environmental evidence indicates that after the ancestors of Native Americans left Asia, they spent 10,000 years on a land bridge that once linked Siberia and Alaska. Archaeological evidence is lacking because it drowned when sea levels rose.

Bisphenol A (BPA) at very low levels can adversely affect developing organs in primates

Posted: 27 Feb 2014 10:48 AM PST

Bisphenol A is a chemical that is used in a wide variety of consumer products and exhibits hormone-like properties. Fetuses, infants, children or adults exposed to the chemical have been shown to exhibit numerous abnormalities, including cancer, as well as reproductive, immune and brain-behavior problems. Now, researchers have determined that daily exposure to very low concentrations of Bisphenol A by pregnant females also can cause fetal abnormalities in primates.

Link found between pollutants, certain complications of obesity

Posted: 27 Feb 2014 09:55 AM PST

A link has been found between a type of pollutant and certain metabolic complications of obesity. The breakthrough could eventually help improve the prevention, diagnosis, and treatment of cardiometabolic risk associated with obesity, such as diabetes, hypertension and cardiovascular disease. Persistent organic pollutants (POPs) are human-made chemicals used in agricultural, industrial and manufacturing processes. Due to their toxicity, POPs have been strictly and internationally regulated to ensure public health. However, because they have the ability to resist environmental degradation, POPs can still be found all around the world, even in areas where they have never been used, and remain omnipresent in our environment and food products. Thus, virtually all humans are exposed to POPs daily. In this new research, POPs have been found to accelerate the development of prediabetes and obesity in mice, thereby mimicking the unfavourable cardiometabolic profile characteristic of certain obese individuals.

Faster anthrax detection could speed bioterror response

Posted: 27 Feb 2014 09:55 AM PST

Shortly following the 9/11 terror attack in 2001, letters containing anthrax spores were mailed around the country killing five people and infecting 17 others. At the time, no testing system was in place to screen the letters. Currently, first responders have tests that can provide results in about 24-48 hours. Now, researchers have tested a new method for anthrax detection that can identify anthrax in only a few hours.

Math anxiety factors into understanding genetically modified food messages

Posted: 27 Feb 2014 09:55 AM PST

People who feel intimidated by math may be less able to understand messages about genetically modified foods and other health-related information, according to researchers.

'Oddball science' has proven worth, biologists say

Posted: 27 Feb 2014 09:55 AM PST

Scoffing at or cutting funds for basic biological research on unusual animal adaptations from Gila monster venom to snail sex, though politically appealing to some, is short-sighted and only makes it more likely that important economic and social benefits will be missed in the long run, say a group of evolutionary biologists.

Ancient 'great leap forward' for life in the open ocean: Cyanobacteria sheds light on how complex life evolved on earth

Posted: 27 Feb 2014 09:55 AM PST

Plankton in the Earth's oceans received a huge boost when microorganisms capable of creating soluble nitrogen 'fertilizer' directly from the atmosphere diversified and spread throughout the open ocean. This event occurred at around 800 million years ago and it changed forever how carbon was cycled in the ocean.

Supplement added to standard diet improves health, prolongs life in mice

Posted: 27 Feb 2014 09:52 AM PST

Activating a protein called Sirtuin 1 (SIRT1) extends lifespan, delays the onset of age-related metabolic diseases, and improves general health in mice. The findings point to a potentially promising strategy for improving health and longevity. SIRT1 is known to play an important role in maintaining metabolic balance in multiple tissues, and studies in various organisms have shown that activating the protein can lead to many health benefits. Also, drugs that increase SIRT1 activity have been found to slow the onset of aging and delay age-associated diseases in several animal models.

Big thaw projected for Antarctic sea ice: Ross Sea will reverse current trend, be largely ice free in summer by 2100

Posted: 27 Feb 2014 08:55 AM PST

A new modeling study suggests that a recent observed increase in summer sea-ice cover in Antarctica's Ross Sea is likely short-lived, with the area projected to lose more than half its summer sea ice by 2050 and more than three quarters by 2100. These changes will significantly impact marine life in what is one of the world's most productive and unspoiled marine ecosystems.

Researchers X-ray living cancer cells

Posted: 27 Feb 2014 08:55 AM PST

Scientists have carried out the first studies of living biological cells using high-energy X-rays. "The new method for the first time enables us to investigate the internal structures of living cells in their natural environment using hard X-rays,' emphasizes the leader of the working group. "Thanks to the ever-greater resolution of the various investigative techniques, it is increasingly important to know whether the internal structure of the sample changes during sample preparation." In future, the new technique will make it possible to study unchanged living cells at high resolution.

Why dark chocolate is good for your heart

Posted: 27 Feb 2014 06:21 AM PST

It might seem too good to be true, but dark chocolate is good for you and scientists now know why. Dark chocolate helps restore flexibility to arteries while also preventing white blood cells from sticking to the walls of blood vessels. Both arterial stiffness and white blood cell adhesion are known factors that play a significant role in atherosclerosis. What's more, the scientists also found that increasing the flavanol content of dark chocolate did not change this effect.

Ecological impacts of invasive species can be readily predicted from features of their behavior

Posted: 27 Feb 2014 06:20 AM PST

Ecologists have studied the behavior of some of the "world's worst" invasive species, including the large-mouth bass, an invasive fish which typically devastates invertebrate and other fish communities wherever it is introduced. They have revealed that the ecological impacts of invasive species might be readily predicted from features of their behavior.

Altruistic suicide in organisms helps relatives by providing nutrients to kin

Posted: 27 Feb 2014 06:14 AM PST

The question of why an individual would actively kill itself has been an evolutionary mystery. Death could hardly provide a fitness advantage to the dying individual. However, a new study has found that in single-celled algae, suicide benefits the organism's relatives. Researchers have known that when an organism commits suicide by digesting up its own body, it releases nutrients into the environment that can be used by other organisms. Now they've proven that these nutrients can only be used by relatives. In fact, the nutrients inhibit the growth of non-relatives, so not only does suicide benefit relatives, it can also harm competitors.

Digital ears in the rainforest: Estimating dynamics of animal populations by using sound recordings and computing

Posted: 27 Feb 2014 06:14 AM PST

A Finnish-Brazilian project is constructing a system that could estimate the dynamics of animal populations by using sound recordings, statistics and scientific computing. The canopy in a Brazilian rainforest is bustling with life, but nothing is visible from the ground level. The digital recorders attached to the trees, however, are picking up the noises of birds.

Secondhand smoke exposure linked to adverse pregnancy outcomes

Posted: 26 Feb 2014 06:12 PM PST

Secondhand smoking is linked with pregnancy loss, including miscarriage, stillbirth and tubal ectopic pregnancy, according to new research. The study findings mark a significant step toward clarifying the risks of secondhand smoke exposure.

Harvested rainwater harbors pathogens

Posted: 26 Feb 2014 01:53 PM PST

South Africa has been financing domestic rainwater harvesting tanks in informal low-income settlements and rural areas in five of that nation's nine provinces. But pathogens inhabit such harvested rainwater, potentially posing a public health hazard, especially for children and immunocompromised individuals, according to a research team. Many of the pathogens are normal fresh water inhabitants, but Salmonella (6% of samples) indicates human fecal contamination, while Yersinia are markers of fecal contamination by wild and domestic animals, according to the report.

New mechanism of gene regulation, enzyme use in cells discovered

Posted: 26 Feb 2014 12:56 PM PST

In the cells of humans and other organisms, only a subset of genes are active at any given time, depending largely on the stage of life and the particular duties of the cell. Cells use different molecular mechanisms to orchestrate the activation and deactivation of genes as needed. One central mechanism is an intricate DNA packaging system that either shields genes from activation or exposes them for use. New research now provides additional insight into how cancer cells use the PARP1 enzyme in this process to resist current therapies, and may point to the next generation of cancer drugs.

Research maze puts images on floor, where rodents look

Posted: 26 Feb 2014 12:56 PM PST

Visual acuity is sharpest for rats and mice when the animals are looking down. Researchers have found that rodents can learn tasks in a fourth to a sixth of the usual number of repetitions when visual stimuli are projected onto the floor of the maze rather than onto the walls. The maze in this study is part real and part virtual. There are actual walls -- often in the shape of a giant piece of farfalle -- but researchers can project any imagery they want onto the floor from below. The use of digital projections makes the maze versatile, but using the floor for projections makes it particularly well-designed for rodent subjects.

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