In recent years, a complicated discussion over which direction solar cells should face -- south or west -- has likely left customers uncertain about the best way to orient their panels. Now researchers are attempting to resolve this issue by developing solar cells that can harvest light from almost any angle, and the panels self-clean to boot. Their report appears in the journal ACS Nano.

Commercial solar panels work best when sunlight hits them at a certain angle. Initially, experts had suggested that solar panels face south to collect the most energy from the sun. But an influential 2013 report by Pecan Street, an energy-research organization, advised that systems tilt westward to maximize efficiency.

Essen, Germany, December 16, 2015 - In a large population-based study of randomly selected participants in Germany, researchers found that participants with anemia, defined as haemoglobin <13 g/dl in men and <12 g/dl in women, showed lower performances in verbal memory and executive functions. Furthermore, mild cognitive impairment (MCI) occurred almost twice more often in participants diagnosed with anemia. This study is published in the Journal of Alzheimer's Disease.

Climate researchers have published direct observations of the reduction and melting of the Greenland Ice Sheet during the latest 110 years, a step up from flawed numerical estimates used for all previous claims. In a recent paper, the researchers claim they can pinpoint where the ice sheet is particularly sensitive and what controls the loss of glacier ice in Greenland - and they close a gap in IPCC's estimate of global sea level budget. 

The discovery of hydrothermal fields at ocean floor opens a new chapter for marine sciences. Fluids in hydrothermal fields are hot and acidic, where at least 400 different biological organisms have been detected, including shrimp, crab and bacteria. Such biological organisms are resistant to high temperature, acidic fluids, and high pressure, and they are dependent on energy and materials (hydrogen gas, methane, ethane and propane, and organic acids) provided by the interaction between basement rocks and seawater (i.e. serpentinization). Hydrothermal fields resemble the early history of Earth. Therefore, serpentinization potentially contributes to the origin and evolution of life.

Many animals change sex at some point in their lives, often after reaching a certain size. Snails called slipper limpets begin life as males, and become female as they grow. A new Smithsonian study shows that when two males are kept together and can touch one another, the larger one changes to female sooner, and the smaller one later. Contact, rather than chemicals released into the water, is necessary for the effect.

"I was blown away by this result," said co-author Rachel Collin, staff scientist at the Smithsonian Tropical Research Institute (STRI). "I fully expected that the snails would use waterborne cues to see their world."

When it comes to accurately identifying a criminal suspect, it makes a difference how sure an eyewitness is, finds a study led by a memory expert at the University of California, San Diego. The American justice system should take note of eyewitness confidence, but only at the time of the initial identification and not at a later date in court. Working with victims and bystanders of actual robberies, the study also finds in favor of the traditional lineup procedure that presents suspects at the same time as known innocents, instead of individually.

The brains of children who suffer clinical depression as preschoolers develop abnormally, compared with the brains of preschoolers unaffected by the disorder, according to new research at Washington University School of Medicine in St. Louis.

Their gray matter -- tissue that connects brain cells and carries signals between those cells and is involved in seeing, hearing, memory, decision-making and emotion -- is lower in volume and thinner in the cortex, a part of the brain important in the processing of emotions.

The new study is published Dec. 16 in JAMA Psychiatry.

It may be your liver (and not your better judgement) that keeps you away from excess sweets this holiday season. Two independent research groups have found the first evidence of a liver-derived hormone that specifically regulates intake of sugars and alcohol in mice. One of the studies also found that the same hormone suppresses the consumption of sweets in primates.

"A lot of work has examined the central mechanisms regulating sugar-seeking behavior, but the post-ingestive mechanisms regulating sugar appetite are poorly understood," says Matthew Potthoff of the University of Iowa, a senior author on one of the papers.