Schools in Colorado are trying to find effective ways to teach the health effects of marijuana use. "When it's legal for your parents to smoke it or grow it," says one educator, "that changes the conversation."
The size of the brain of a chimpanzee (right) is considerably smaller than that of a human brain. Probably multiple stretches of DNA help determine that, geneticists say.
Science Photo Library/Corbis
People who practice free-range parenting say it makes kids more independent, but others see it as neglect. State and local laws don't specify what children are allowed to do on their own.
The ParaGuard IUD, which releases copper into the uterine cavity, can last up to 10 years. In clinical studies, the pregnancy rate among women using the device was less than 1 pregnancy per 100 women annually.
Mark Harmel/Science Source