sentences:  He has appeared as an expert on the CBS Evening News with Dan Rather, CNN, CNN International, MSNBC, and network news shows throughout the U.S. and the world.He has been profiled on National Public Radio's "All Things Considered" and has been quoted in "The New York Times", "The Washington Post", "The Boston Globe", "The Times", "Le Monde", "Pravda", "People's Daily" and other publications throughout the U.S. and the world.Siegel gives frequent lectures on stem cells and public policy, speaking before the United Nations, international and U.S.-based biotechnology groups, and at numerous colleges and universities.