Dr. Allan Ropper speaks with residents and fellows as they do rounds at the neuroscience intensive care unit at Brigham and Women's Hospital in Boston. M. Scott Brauer for NPR hide caption

itoggle caption M. Scott Brauer for NPR

Proton beam therapy can precisely target tumors to avoid harming surrounding tissue, advocates say. Blythe Bernhard/St. Louis Post-Dispatch/MCT/Landov hide caption

itoggle caption Blythe Bernhard/St. Louis Post-Dispatch/MCT/Landov

Low water levels, like at this reservoir near Gustine, Calif., bring birds and mosquitoes together and help transmit West Nile virus to humans. Rich Pedroncelli/AP hide caption

itoggle caption Rich Pedroncelli/AP

Psychologists say spanking and other forms of corporal punishment don't get children to change their behavior for the better. Science Photo Library/Corbis hide caption

itoggle caption Science Photo Library/Corbis