Chemists George Whitesides, of Harvard University in Cambridge, Massachusetts, and Richard Zare, of Stanford University in California, have been announced as winners of this year?s King Faisal International Prize for Science. James Thomson, of the University of Wisconsin, and Shinya Yamanaka, of the University of California, San Francisco, and Kyoto University, Japan, took the prize for medicine for their work on stem cells. Winners receive a medal and share US$200,000 in each category.