A piece of the brain's hypothalamus is key to animals' fear of territorial rivals and predators, according to a new study. Without it, animals lose all sense of caution.

Researchers have identified a key to eye development -- a protein that regulates how the light-sensing nerve cells in the retina form. While still far from the clinic, the latest results could help scientists better understand how nerve cells develop.

Researchers have found that carbon nanotubes can significantly improve the performance of electrical contacts that are common in millions of motors used in a variety of electrical applications. New research concludes that "brush contacts" made of carbon nanotubes had 10 times less resistance than did the carbon-copper composite brushes commonly used today.

Freezing kidney tumors -- using a safe minimally invasive interventional radiology treatment that kills the cancer 100 percent effectively without surgery -- should be the gold standard or first treatment option for all individuals with tumors that are 4 cm in size or smaller. And, this treatment -- interventional cryoablation -- is a viable option for people with larger tumors, according to two studies.

For the first time, researchers have measured the ability of a single, very long molecular wire to carry electric current. Until now, there were only statistical measurements on a collection of wires a few nanometers long. Now, thanks to an ingenious experiment using a scanning tunneling microscope, the researchers have characterized individual polymer chains of known length, up to 20 nanometers long. They confirm what is predicted by theory: the ability to conduct electric current decreases exponentially with the length of the wire.

When we are faced with a decision, and we're not sure what to do, usually we'll just go with the majority opinion. When do we begin adopting this strategy of "following the crowd"? A new report in Psychological Science suggests that this tendency starts very early on, around preschool age.