4:18 p.m., April 9, 2008--University of Delaware researchers, in collaboration with U.S. and international colleagues, have found a new type of molecule--a kind of “micro-switch”--that can turn off genes in rice, which is the primary source of food for more than half the world’s population. The discovery is reported in the March 25 issue of the Proceedings of the National Academy of Sciences of the United States of America.