Las Vegas - A study published recently in PLOS ONE authored by Dr. Henry Sun and his postdoctoral student Dr. Gaosen Zhang of Nevada based research institute DRI provides new evidence that Earth bacteria can do something that is quite unusual. Despite the fact that these bacteria are made of left-handed (L) amino acids, they are able to grow on right-handed (D) amino acids. This DRI study, funded by the NASA Astrobiology Institute and the NASA Exobiology Program, takes a closer look at what these implications mean for studying organisms on Earth and beyond.

In a new paper, researchers writing in Current Biology show how lactase persistence variants tell the story about the ancestry of the Khoe people in southern Africa and that their pastoralist practices were probably brought to southern Africa by a small group of migrants from eastern Africa.

In 2005, NASA's Cassini spacecraft sent pictures back to Earth depicting an icy Saturnian moon spewing water vapor and ice from fractures, known as "tiger stripes," in its frozen surface. It was big news that tiny Enceladus—a mere 500 kilometers in diameter—was such an active place. Since then, scientists have hypothesized that a large reservoir of water lies beneath that icy surface, possibly fueling the plumes. Now, using gravity measurements collected by Cassini, scientists have confirmed that Enceladus does in fact harbor a large subsurface ocean near its south pole, beneath those tiger stripes.

Enceladus—one of Saturn's smaller satellites—has joined the ranks of Titan and Europa as a moon that appears to have liquid water splashing around inside of it, researchers say. New gravity data from the Cassini spacecraft, which has been exploring the planet's moons for 10 years, reveal that Enceladus harbors an ocean of water beneath 18 to 24 miles (30 to 40 kilometers) of ice at its surface.

A team of Italian and American scientists led by Luciano Iess at Sapienza Università di Roma in Rome, Italy investigated the moon's gravity field and the notable asymmetry it exhibits between northern and southern hemispheres to reach these conclusions. Their results appear in the 4 April issue of Science.

Cigarette smoking among obese women appears to interfere with their ability to taste fats and sweets, a new study shows. Despite craving high-fat, sugary foods, these women were less likely than others to perceive these tastes, which may drive them to consume more calories.

Spit-powered, micro-sized microbial fuel cells produce enough energy to run on-chip applications, according to a paper in
Asia Materials.

Microbial fuel cells create energy when bacteria break down organic material producing a charge that is transferred to the anode. Bruce Logan, Professor Environmental Engineering at Penn State, has studied microbial fuel cells for more than ten years and usually looks to wastewater as a source for both the organic material and the bacteria to create either electricity or hydrogen, but says these tiny machines are a bit different.