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Comparing dredged and undredged sections of the Allegheny River, reduced populations of fish and less variety of aquatic life occurred in areas where gravel extraction took place, according to researchers in Penn State's College of Agricultural Sciences,.

The researchers investigated navigation pools 7 and 8 near Kittanning and Templeton and published their results in the journal Freshwater Biology.

Overprecision — excessive confidence in the accuracy of our beliefs — can have profound consequences, inflating investors' valuation of their investments, leading physicians to gravitate too quickly to a diagnosis, even making people intolerant of dissenting views. Now, new research confirms that overprecision is a common and robust form of overconfidence driven, at least in part, by excessive certainty in the accuracy of our judgments.

The mechanism responsible for generating part of the skeletal support for the membrane in animal cells is not yet clearly understood. Now, Jean-François Joanny from the Physico Chemistry Curie Unit at the Curie Institute in Paris and colleagues have found that a well-defined layer beneath the cell outer membrane forms beyond a certain critical level of stress generated by motor proteins within the cellular system. These findings, which offer a new understanding of the formation of this so-called cortical layer, have just been published in EPJ E.

DARIEN, IL – A new study suggests that frequent binge drinking is associated with insomnia symptoms in older adults.

Results show that overall, 26.2 percent of participants had two or less binge drinking days per week, on average, and 3.1 percent had more than two days per week, on average. After adjustment for demographic variables, medical conditions, and elevated depressive symptoms, participants who binged on an average of more than two days a week had an 84 percent greater odds of reporting an insomnia symptom compared to non-binge drinkers.

The microorganism Methanosarcina acetivorans lives off everything it can metabolize into methane. How it finds its sources of energy, is not yet clear. Scientists at the Ruhr-Universität Bochum together with colleagues from Dresden, Frankfurt, Muelheim and the USA have identified a protein that might act as a "food sensor". They characterized the molecule in detail and found both similarities and differences to the system that is responsible for the search for food in bacteria. The team reports in the Journal of Biological Chemistry.

Boston, Mass.— A new study shows that when a liver from a deceased adult or adolescent donor is split into two separate portions for transplantation—with the smaller portion going to a young child and the larger to an adult—the smaller portion used for the child will last just as long as if the child had received a whole organ from a donor close to his size.

Agri-environment schemes aimed to promote biodiversity on farmland have positive effects on wild bees, hoverflies and butterflies. Effects on diversity and abundance were strongest when agri-environment schemes prescribed sowing wild-flowers, the more flowering species the better. Organic farms, set-aside land or fields receiving reduced amounts of fertilizer and pesticides generally hosted more wild pollinators than conventionally farmed land.

Nanotechnologies require a detailed knowledge of the molecular state. For instance, it is useful to know when and how a generic polymer, a long chain of polymers (chain of beads), knots. The study of molecular entanglement is an important field of study as the presence of knots affects its physical properties, for instance the resistence to traction. Previous studies had mainly obtained "static" data on the knotting probability of such molecules. In other words, they focused on the likelihood that a polymer may knot.

PROVIDENCE, R.I. [Brown University] — In India most people who are HIV positive don't know it, yet testing and treatment are relatively cheap and available. It would therefore meet international standards of cost-effectiveness — and save millions of lives for decades — to test every person in the billion-plus population every five years according to a new study published in the journal PLoS One.

African medicinal plants contain chemicals that may be able to stop the spread of cancer cells. This is the conclusion of researchers following laboratory experiments conducted at Johannes Gutenberg University Mainz (JGU). The plant materials will now undergo further analysis in order to evaluate their therapeutic potential. "The active substances present in African medicinal plants may be capable of killing off tumor cells that are resistant to more than one drug.

Butterflies are extremely sensitive to changes in temperature and new research has revealed that when summer weather turns bad the silver-spotted skipper battles for survival. The butterfly, which previously faced extinction from habitat loss, is recovering following conservation efforts but the recent cool wet summers in England have almost stalled its progress.

TORONTO, ON – Many plants are self-fertilizing, meaning they act as both mother and father to their own seeds. This strategy – known as selfing – guarantees reproduction but, over time, leads to reduced diversity and the accumulation of harmful mutations. A new study published in the scientific journal Nature Genetics shows that these negative consequences are apparent across a selfing plant's genome, and can arise more rapidly than previously thought.

Canada's Mackenzie River basin -- among the world's most important major ecosystems -- is poorly studied, inadequately monitored, and at serious risk due to climate change and resource exploitation, a panel of international scientists warn today.

PISCATAWAY, NJ – They may volunteer to be the one to get their friends home safely, but "designated drivers" often drink—even to a level that impairs them behind the wheel, according to a report in the July issue of the Journal of Studies on Alcohol and Drugs.

The study, of more than 1,000 bar patrons, found that approximately 40 percent of designated drivers had downed alcohol. What's more, most of those drinkers had blood alcohol levels that could impair their driving.

A new study has found that women can be screened for colorectal cancer at least five to 10 years later than men when undergoing an initial "virtual colonoscopy." Published early online in CANCER, a peer-reviewed journal of the American Cancer Society, the findings may help establish guidelines for the use of this screening technique, which is less invasive than a traditional colonoscopy.