Researchers have measured the highest level of ultraviolet radiation ever recorded on the Earth's surface.

These extraordinary UV fluxes, observed in the Bolivian Andes only 1,500 miles from the equator, are far above those normally considered to be harmful to both terrestrial and aquatic life, though that has to be calibrated. A beach in Brazil also has radiation levels far above safe levels, yet people visit it for that reason. And plane flights provide even more radiation than that. 

Adults with extreme obesity have increased risks of dying at from cancer, heart disease, stroke, diabetes, and kidney and liver diseases, according to results of an analysis of data pooled from 20 large studies of people from three countries.

The analysis led by researchers from the National Cancer Institute (NCI) found that people with class III (or extreme) obesity had a dramatic reduction in life expectancy compared with people of normal weight.

There is nothing more natural than sexes. Throughout evolution, living things have repeatedly developed physically distinct genders but how this happens has been a puzzle.

A discovery in the multicellular green alga Volvox carteri may be the revelation of the genetic origin of male and female sexes, showing how they evolved from a more primitive mating system in a single-celled relative.

California leads the country in creating science policy by opposition; if Republicans are against it, California will pass it. Taxpayers are swimming in debt and wondering why they wasted $3 billion paying a bureaucrat $500,000 a year to redistribute money on human embryonic stem cell research, with nothing to show for it, and their landmark cap-and-trade system for regulating greenhouse gases  has led to 50 percent higher utility rates for consumers but has done nothing for climate change - all of America's drop in CO2 was caused by natural gas uptake in the rest of the nation.

Combining the smoking cessation medication varenicline with nicotine replacement therapy was more effective than varenicline alone at achieving tobacco abstinence at 6 months, according to a study in the July 9 issue of JAMA.

The combination of behavioral approaches and pharmacotherapy are of proven benefit in assisting smokers to quit. Combining nicotine replacement therapy (NRT) with varenicline has been a suggested treatment to improve smoking abstinence, but its effectiveness is uncertain, according to background information in the article.

Planet Mercury's metal-rich composition is a puzzle in planetary science. According to a new simulation, Mercury and other unusually metal-rich objects in the solar system may be relics left behind by collisions in the early solar system that built the other planets.

The migration of tropical fish poses a serious threat to the areas they invade, because they overgraze on kelp forests and seagrass meadows. The harmful impact of tropical fish is already evident in southern Japanese waters and the eastern Mediterranean, where there have been dramatic declines in kelps.

There is also emerging evidence in Australia and the US that the spread of tropical fish towards the poles is causing damage in the areas they enter.

The authors blame the increased fish on warming oceans due to climate change that have led to hotspots in regions where the currents that transport warm tropical waters towards the poles are strengthening.

If you are having fun rather than doing exercise because you are worried about your health, you'll eat less, according to a new paper which delves into how to market to your brain.

Some people really like to run, or they look forward to exercise. They are probably already thinking about food consumption because they recognize that they did the work. Other people have painted themselves into a psychological corner - they think of exercise and workouts and calories and then eat more afterward. It's well known that most people tend to undercount calories ingested and overcount those in a workout.

DURHAM, N.C. – The changing dynamic of health studies driven by "big data" research projects will empower patients to become active participants who provide real-time information such as symptoms, side effects and clinical outcomes, according to researchers at Duke Medicine.

The analysis, published in the July 2014 issue of Health Affairs, lays out a new paradigm for health research, particularly comparative effectiveness studies that are designed to assess which therapies work best in routine clinical practice.

One of the first predators on land, a 410-million-year-old arachnid, has been virtually brought back to life. Paleontologists used exceptionally preserved fossils from the Natural History Museum in London to create the video showing the most likely walking gait of the animal.

The scientists used the fossils - thin slices of rock showing the animal's cross-section - to deduce the range of motion in the limbs of this ancient, extinct early relative of the spiders. From this, and comparisons to living arachnids, the researchers used the open source computer graphic program  Blender to create a video showing the animals walking.