A good night's sleep is essential for good health, but many Latinos in the U.S. just don't get enough of it. To shed light on possible reasons why, researchers are studying the sleep habits of those living near the U.S.-Mexico border. "I honestly don't think we have a very good understanding of what the rates of (sleep problems) are in the Latino community," said John Ruiz, a psychology professor at the University of Arizona in Tucson.