Imagine if a naturally occurring chemical in your body could help make you feel more calm and relaxed – but it would only work during the long days of summer.

The same chemical would, instead, make you aggressive and nasty when you were exposed to less daylight during the winter.

That's exactly what occurs for a specific species of mouse, according to a new study at Ohio State University.

A patch of Martian soil analyzed by NASA's rover Spirit is so rich in silica that it may provide some of the strongest evidence yet that ancient Mars was much wetter than it is now. The processes that could have produced such a concentrated deposit of silica require the presence of water.

Members of the rover science team heard from a colleague during a recent teleconference that the alpha particle X-ray spectrometer, a chemical analyzer at the end of Spirit's arm, had measured a composition of about 90 percent pure silica for this soil.

A new study in this month’s Journal of Personality and Social Psychology explains why NPR listeners always think they are right. When it comes to financial decisions or even concerns about terrorism, people are likely to be influenced by what others think but repeated exposure to one viewpoint can have almost as much influence as exposure to shared opinions from multiple people.

Hearing an opinion multiple times increases the recipient’s sense of familiarity and in some cases gives a listener a false sense that an opinion is more widespread then it actually is.

The use of targeted nanoparticles offers promising techniques for cancer treatment. Researchers in the laboratory of Mark E. Davis at the California Institute of Technology have been using small interfering RNA (siRNA), sometimes known as silencing RNA, to "silence" specific genes that are implicated in certain malignancies.

One of the primary challenges associated with this type of therapy is delivering the therapeutic agent into the body and then to the tumor in a safe and effective manner. By using targeted nanoparticles, researchers have demonstrated that systemically delivered siRNA can slow the growth of tumors in mice without eliciting the toxicities often associated with cancer therapies.

Approximately ten million American adults have problems controlling their bladders. Bladder disease affects both men and women and can include incontinence or interstitial cystitis, a chronic inflammatory condition that causes frequent, urgent and painful urination and pelvic discomfort.

Herbal agents could be used to treat inflammatory bladder diseases, according to a preliminary study that looked at the ability of green tea to protect bladder cells from inflammation. The University of Pittsburgh School of Medicine study, found that components of green tea protected bladder cells from damage in culture.

The ability to regenerate nerve cells in the body could reduce the effects of trauma and disease in a dramatic way. In two presentations at the NSTI Nanotech 2007 Conference, researchers describe the use of nanotechnology to enhance the regeneration of nerve cells. In the first method, developed at the University of Miami, researchers show how magnetic nanoparticles (MNPs) may be used to create mechanical tension that stimulates the growth and elongation of axons of the central nervous system neurons. The second method from the University of California, Berkeley uses aligned nanofibers containing one or more growth factors to provide a bioactive matrix where nerve cells can regrow.