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.

The mass of the top quark is a very important parameter of the standard model: using its value together with other no less fundamental ones (the W boson mass, the Higgs mass, and many parameters describing the properties of Z bosons) it is possible to study in great detail the predictions of the theory. In particular, due to the way heavy particles influence the Higgs field, one may verify the consistence of the standard model by looking at a graph where the top quark mass is in the x axis and the W boson on the y axis: different hypotheses for the Higgs boson mass then lie on different parallel curves. One example of such a graph is shown below. It is too complex to discuss it in detail here, but if you are curious I can supply more information in the comments thread.

Enjoy Greek yogurt?

Maybe, if you hate nature.

Because it is now a $2 billion a year industry, activists have turned on it, a fate that the $29 billion organic food industry has so far escaped.

One Green Planet says the greek yogurt manufacturing process is "creating an ecological nightmare beyond all comprehension" which tells you that no one at One Green Planet can do simple math. And they are prone to hyperbole. It is entirely in my ability to comprehend what a cup of yogurt can do.

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.

Memory loss is a debilitating consequence of dementia such as Alzheimer’s disease (AD), an incurable condition contributing to a progressive loss of cognitive function. But what is the cause of memory loss in AD?

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.

MADISON – For Simon Gilroy, sometimes seeing is believing. In this case, it was seeing the wave of calcium sweep root-to-shoot in the plants the University of Wisconsin-Madison professor of botany is studying that made him a believer.

Gilroy and colleagues, in a March 24, 2014 paper in the Proceedings of the National Academy of Sciences, showed what long had been suspected but long had eluded scientists: that calcium is involved in rapid plant cell communication.

It's a finding that has implications for those interested in how plants adapt to and thrive in changing environments. For instance, it may help agricultural scientists understand how to make more salt- or drought-tolerant plants.