A team led by the University of Colorado at Boulder and the University of Milan has discovered some unexpected forms of liquid crystals of ultrashort DNA molecules immersed in water, providing a new scenario for a key step in the emergence of life on Earth.

CU-Boulder physics Professor Noel Clark said the team found that surprisingly short segments of DNA, life's molecular carrier of genetic information, could assemble into several distinct liquid crystal phases that "self-orient" parallel to one another and stack into columns when placed in a water solution. Life is widely believed to have emerged as segments of DNA- or RNA-like molecules in a prebiotic "soup" solution of ancient organic molecules.

Direct-to-consumer advertising for commercial genetic testing is on the rise and may be problematic, according to a Massachusetts General Hospital physician. In the December issue of Obstetrics & Gynecology, Erin Tracy, MD, MPH, warns that such testing is poorly regulated and may present potential pitfalls for patients and physicians.

“Some of the tests that are being offered have no proven clinical validity whatsoever and are quite costly,” says Tracy. “So patients spend money trying to identify a particular gene to figure out if their child is prone to addictive behavior, for example.

Water chemistry and mineralogy are scientific fields that have been around long enough to develop extensive knowledge and technologies. The boundary of water and rock, however, is not a thin wet line but the huge new field of nanoparticle science.

Scientists are discovering that aquatic nanoparticles, from 1 to 100 nanometers, influence natural and engineered water chemistry and systems differently than similar materials of a larger size. “Nanoparticles are in an awkward intermediate state, between elements dissolved in water and minerals that you can hold in your hand,” said Michael Hochella Jr., University Distinguished Professor of geosciences at Virginia Tech. “The nanoscale represents a transition zone.

Even after more than a year of maintaining a normalized body weight, young women who recovered from anorexia nervosa show vastly different patterns of brain activity compared to similar women without the eating disorder, Walter H. Kaye, M.D., professor of psychiatry, University of Pittsburgh School of Medicine, and colleagues report in the December issue of the American Journal of Psychiatry.

Studying these differences in brain function could lead to a better understanding of why some young women, who are typically worriers and perfectionists in childhood, are at greater risk of developing the disorder. Evidence also shows that such patterns of temperament persist even after recovery.

Messier 74, also called NGC 628, is a stunning example of a 'grand-design' spiral galaxy that is viewed by Earth observers nearly face-on. Its perfectly symmetrical spiral arms emanate from the central nucleus and are dotted with clusters of young blue stars.

In the new Hubble image we can also see a smattering of bright pink regions decorating the spiral arms. These are huge, relatively short-lived, clouds of hydrogen gas which glow due to the strong radiation from hot, young stars embedded within them; glowing pink regions of ionized hydrogen (hydrogen that has lost its electrons).

Right in time for the festive season, ESA's XMM-Newton X-ray observatory has discovered a huge cloud of high-temperature gas resting in a spectacular nearby star-forming region, shaped somewhat like the silhouette of Santa Claus.

An early present for astronomers, the cloud suggests that hot gas from many star-forming regions leaks into the interstellar medium.

The Orion nebula is the nearest dense star-forming region to Earth that contains stars much more massive than the Sun. XMM-Newton’s newly-discovered gas cloud is composed of winds blowing from these high-mass stars that are heated to millions of degrees as they slam into the surrounding gas.