If you live in an area where solar power is close to viable, you probably also do not get a lot of rain. Over time, dust and dirt build up on solar panels, leading to a loss of efficiency.

But not enough to warrant washing them, according to an analysis by the University of California, San Diego. 

A longstanding puzzle has been solved.

How do northern flying squirrels (Glaucomys sabrinus) locate truffles (Gautieria monticola) – bearing in mind that the truffles are a subterranean and ephemeral but primary food source?

Sanjay Pyare (Assistant Professor of GIS and Landscape Ecology, at the University of Alaska Southeast, ) and colleague William S Longland (at the Agricultural Research Service, Reno, NV) investigated this question back in 2001, and published the results of their observations in the Canadian Journal of Zoology, 2001, 79:1007-1015.

In the beginning, there are embryonic stem cells, which divide and increasingly differentiate as they do so. The ensuing tissue cells remain in a stable state, a skin cell does not spontaneously change into a nerve cell or heart muscle cell.

The applications for embryonic stem cells
are many: When nerve tissue becomes diseased, for example, then doctors could take healthy cells from the patient's own skin. They could then reprogram these to develop into nerve cells. These healthy nerve cells would then be implanted into the diseased tissue or even replace it entirely. This would treat, and ideally heal, diseases such as Parkinson's disease. 

Up to 20 percent of infertile couples in America have unknown reasons for their infertility but researchers led by Catherine Racowsky, PhD, director of the Assisted Reproductive Technologies Laboratory at Brigham and Women's Hospital, wants to fill in that blank, and hints that it could be exposure to Bisphenol-A (BPA). 

Oxytocin, called the 'love hormone' in popular accounts, affects men and women differently in social contexts, say a group of psychologists. In men it improves the ability to identify competitive relationships whereas in women it facilitates the ability to identify kinship.

Oxytocin is released in our bodies in various social situations. Our bodies release it at highwe levels during positive social interactions such as falling in love, experiencing an orgasm or giving birth and breastfeeding and in previous papers, 
Prof. Simone Shamay-Tsoory from the Dept. of Psychology at the University of Haifa

Raising fish in tanks  doesn't help them all that much when they are released into the wild - but there may be an easy fix: put in hiding places and obstacles. It makes fish smarter and improves their chances of survival in nature, according to a new paper.

Why does that matter? Because conservation fish hatcheries raise cod, salmon, trout and other types of fish and release them in places where their species may be threatened, or where their populations are declining.  

Astronomers have found a new way of measuring the spin in supermassive black holes. By viewing optical, ultra-violet and soft x-rays generated by heat as the black hole fed, they were able to measure how far the disc was from the black hole. 

Researchers have devised a way to measure the internal properties of stars, a method that offers more accurate assessments of their orbiting planets. 

The astronomers examined HD 52265, a star  nearly 20 percent more massive than our Sun
 that is approximately 92 light years away. More than a decade ago, scientists identified an exopanet in the star's orbit. HD 52265 became an ideal model for both measuring stars' properties and how such properties can shed light on planetary systems.

Previously, scientists inferred stars' properties, such as radius, mass, and age, by considering observations of their brightness and color. Often these stars' properties were not known to sufficient accuracy to further characterize the nearby planets.

Time to reconsider the relationship between science and the supernatural. A number of colleagues in both science and philosophy argue that the supernatural is nothing special, that god-related hypotheses can be tested by ordinary scientific methods, and that — given the repeated failure of such tests — the only rational conclusion is that science has pretty much shown that there is no such thing as the supernatural.

A statistical model based on risk factors says it can predict the probability (absolute risk) of a woman developing breast, ovarian, and endometrial (womb) cancer using easily obtainable information on known risk factors for these cancers.