Diver Down: ESA astronaut Thomas Pesquet EVA Training

With lights blazing dramatically from his chest, ESA astronaut Thomas Pesquet descends underwater during spacewalk training at NASA's Neutral Buoyancy Lab in Houston, TX. 

Training and support divers stand by, monitoring his movements. 

Astronauts use underwater training on a life-size mockup of the space station as one way to prepare for their mission. 

Floating underwater represents one of the best ways to train on Earth for weightlessness. 

Credit: ESA/NASA

Standby: Electric Fish Turn Down Charge for Energy Efficiency

Fish that use electric fields to sense their environments dim their signals to save energy during the day when they are resting.

Sternopygus macrurus, a South American river fish, is a natural practitioner of energy efficiency. It can reshape the charged-molecule channels in its electricity-producing cells to tone down its electrical signature within a matter of minutes.

“This is a really expensive signal to produce. The fish is using up a lot of its energy budget,” said neurobiologist Michael Markham at the University of Texas at Austin, lead author of a paper in PLoS Biology on the fish. “These animals are saving energy by reducing the strength of the signal when they are not active.”

Thousands of fish and other oceanic creatures use electrical fields to help them perceive their environments. The most famous is the electric eel, which a colleague of Markham’s termed “a frog with a cattle prod attached,” but most animals use the electrical signals in more subtle ways.

The fish’s standard electrical signal runs at 100 hertz; if you turn the electrical signal into sound, it sounds like a hum high whine. In laboratory experiments, the fish can detect tiny bugs half a centimeter wide and easily navigate obstacles by detecting the changes the objects cause in the electrical field.

Heart Attacks Down 17% After Smoking Ban

Smoking bans have an immediate and dramatic effect on reducing heart attacks, according to two new analyses of laws in the USA, Canada and Europe.

Two separate analyses released Monday each found that heart attack rates fall 17% within a year after smoking bans take effect.

One analysis, which included 13 studies, appears in Circulation: Journal of the American Heart Association. A second analysis, which considered 11 studies, appears in the Journal of the American College of Cardiology.

Cigarette smoke can trigger a heart attack in people with underlying heart disease by causing clots or spasms in the blood vessels, says David Goff, a spokesman for the American Heart Association who wasn't involved in either study.

Given that there are about 920,000 heart attacks every year, the studies suggests that public smoking bans could prevent more than 150,000 of these, according to the Cardiology paper.

Taken together, the findings provide strong, consistent evidence that the country should enact more smoke-free laws, Goff says.

"This is a huge, huge effect for a very, very low cost," says Stanton Glantz of the University of California-San Francisco, co-author of the Circulation study.