HOUSTON - (June 14, 2016) - In 1988, scientists in Switzerland looked through a microscope and saw something they didn't expect: two sections of an X-shaped chromosome spiraling in opposite directions. Now scientists at Rice University have confirmed that such anomalies are indeed possible.

Peter Wolynes, a theoretical biological physicist, and Bin Zhang, a postdoctoral associate, saw the same phenomenon in their sophisticated computer models of DNA, a finding they said should encourage deeper investigation of a basic biological process. Understanding such processes is important as researchers seek new ways to fight cancer and other diseases.

Their work is described today in Physical Review Letters.

Shells of California mussels collected from the Pacific Ocean off the coast of Washington in the 1970s are on average 32 percent thicker than modern specimens, according to a new study published by University of Chicago biologists.

Shells collected by Native Americans 1,000 to 1,300 years ago were also 27 percent thicker than modern shells, on average. The decreasing thickness over time, in particular the last few decades, is likely due to ocean acidification as a result of increased carbon in the atmosphere.

Chiral molecules, compounds that come in otherwise identical mirror image variations, like a pair of human hands--are crucial to life as we know it. Living things are selective about which "handedness" of a molecule they use or produce. For example, all living things exclusively use the right-handed form of the sugar ribose (the backbone of DNA), and grapes exclusively synthesize the left-handed form of the molecule tartaric acid. While homochirality--the use of only one handedness of any given molecule--is evolutionarily advantageous, it is unknown how life chose the molecular handedness seen across the biosphere.

The risk of people developing Type 2 diabetes is lower for people who consume more whole grains, fruits, vegetables, nuts, and legumes, notes a study in PLOS Medicine.

A new study reports the first detection of chiral molecules in space, paving the way to understanding why chirality is "biased" on Earth. Our planet is home to a puzzle involving chiral molecules, those that, despite being mirror images of each other, don't exactly match; imagine a left-handed and right-handled glove, for example. They aren't interchangeable. Life on Earth is made of groups of such molecules that overwhelmingly share just one type of handedness, a phenomenon known as homochirality. The amino acids that make up the proteins in our bodies, for example, are all left-handed.

Six mating positions (amplexus modes) are known among the almost 7,000 species of frogs and toads found worldwide. However, the Bombay night frog (Nyctibatrachus humayuni), which is endemic to the Western Ghats Biodiversity hotspot of India, mates differently. In a new study, scientists have described a new (seventh) mode of amplexus -- now named as dorsal straddle.