A rigorous analysis of more than 20,000 medical records concludes that erectile dysfunction drugs, such as Viagra, are not a cause of melanoma, an often deadly form of skin cancer, despite the higher risk for the disease among users of these drugs. 

The analysis, led by researchers at NYU Langone Medical Center and its Laura and Isaac Perlmutter Cancer Center, of medical records for some 20,235 mostly white men suggests instead that the likely source of the observed uptick in malignant melanoma risk among users of erectile dysfunction drugs is socioeconomic and lifestyle based.

Renewable energy targets mandates and subsidies now in place in 164 countries powered the growth of solar, wind and other green technologies to record-breaking energy generation capacity in 2014. So to advocates that means CO2 emissions and growth do not have to go hand-in-hand. To critics, the fact that these alternative energy schemes only work when there are mandates and subsidies means fossil fuels should be cleaner, not eliminated.

According to REN21's latest Renewables Global Status Report, policymakers continued to focus on adapting existing policies to keep pace with rapidly changing costs and circumstances.

Men with an elevated, genetically inherited risk for prostate cancer could be routinely identified with a simple blood or urine test, scientists at UC San Francisco and Kaiser Permanente Northern California have concluded, potentially paving the way to better or earlier diagnosis.

The study, which compared 7,783 men with prostate cancer to 38,595 men without the disease, is available online and will be published in an upcoming issue of the journal Cancer Discovery.

An international team of scientists has found some of the best evidence yet that Venus, Earth's nearest neighbor, is volcanically active.

In combing through data from the European Space Agency's Venus Express mission, the scientists found transient spikes in temperature at several spots on the planet's surface. The hotspots, which were found to flash and fade over the course of just a few days, appear to be generated by active flows of lava on the surface.

"We were able to show strong evidence that Venus is volcanically, and thus internally, active today," said James W. Head, a geologist at Brown University and co-author of a paper describing the new research. "This is a major finding that helps us understand the evolution of planets like our own."

High in the sky where the cirrus ice crystal clouds form, jet contrails draw their crisscross patterns. Now researchers have found that these elevated ice cloud trails can influence temperatures on the ground and affect local climate.  

For contrails to form, the atmosphere at the level the jet is flying must be cold enough that the moisture from the jet exhaust freezes into ice crystals. There also must be enough moisture in the air that the clouds that form remain in the sky for at least a few hours as persisting contrails.

Neanderhals became extinct about 40,000 years ago but contributed on average one to three percent to the genomes of present-day Eurasians. Researchers have now analyzed DNA from a 37,000 to 42,000-year-old human mandible from Oase Cave in Romania and have found that six to nine percent of this person's genome came from Neanderthals, more than any other human sequenced to date. 

Because large segments of this individual's chromosomes are of Neanderthal origin, a Neanderthal was among his ancestors as recently as four to six generations back in his family tree. This shows that some of the first modern humans that came to Europe mixed with the local Neanderthals.