His team presented its findings at the 1996 American Chemical Society meeting. In vitro tests show the compound inhibits fertility in rats by 98 percent with no affect on hormones, Hall reported in the April issue of Biology of Reproduction . Fertilization was inhibited by 90 percent in in vivo tests. The compound appears to have a short onset of action, negligible effects on the libido and no residual effect after use is ended. It works by blocking one of two variant forms of an enzyme that gives sperm cells the ability to recognize and penetrate eggs.
More research is needed to learn if it is safe and effective for humans.
A bug-like alien named Herman could one day teach at your child's school. He takes a child to four planets and explains the different ecologies on each. Then he asks the child to create a plant suited to each environment. By analyzing their responses to questions, Herman's artificial intelligence sizes up its human pupils and adjusts the complexity of the program to their level of understanding. In field tests at Martin Middle School in Raleigh, the program, which is the first of a new generation of smart educational software being developed at NC State, drew rave reviews.