of the International Monetary Fund (Rodrigo Rato, MBA); executive director of UNICEF (Ann Veneman, MPP); member of the European Parliament (Bruno Megret, MS); and judge of the World Court (Joan Donoghue, JD). Alumni have made important contributions to science. Some have concentrated their studies on the very small universe of atoms and molecules. Nobel laureate William F. Giauque (BS 1920, PhD 1922) investigated chemical thermodynamics, Nobel laureate Willard Libby (BS 1931, PhD 1933) pioneered radiocarbon dating, Nobel laureate Willis Lamb (BS 1934, PhD 1938) examined the hydrogen spectrum, Nobel laureate Hamilton O. Smith (BA 1952) applied restriction enzymes to molecular genetics, Nobel laureate Robert Laughlin (BA math 1972) explored the fractional quantum Hall effect, and Nobel laureate Andrew Fire (BA math 1978) helped to discover RNA interference-gene silencing by double-stranded RNA. Nobel laureate Glenn T. Seaborg (PhD 1937) collaborated with Albert Ghiorso (BS 1913) to discover 12 chemical elements, such as americium, berkelium, and californium. David Bohm (PhD 1943) discovered Bohm diffusion. Nobel laureate Yuan T. Lee (PhD 1965) developed the crossed molecular beam technique for studying chemical reactions. Carol Greider (PhD 1987), professor of molecular biology and genetics at Johns Hopkins University School of Medicine, was awarded the 2009 Nobel Prize in medicine for discovering a key mechanism in the genetic operations of cells, an insight that has inspired new lines of research into cancer. Harvey Itano (BS 1942) conducted breakthrough work on sickle cell anemia that marked the first time a disease was linked to a molecular origin. While he was valedictorian of Berkeley's class of 1942, he was unable to attend commencement exercises due to internment. Narendra Karmarkar (PhD 1983) is known for the interior point method, a polynomial algorithm for linear programming known as Karmarkar's algorithm. National Medal of Science laureate Chien-Shiung Wu (PhD 1940), often known as the "Chinese Madame Curie", disproved the Law of Conservation of Parity for which she was awarded the inaugural Wolf Prize in Physics. Kary Mullis (PhD 1973) was awarded the 1993 Nobel Prize in Chemistry for his role in developing the polymerase chain reaction, a method for amplifying DNA sequences. Daniel Kahneman was awarded the 2002 Nobel Memorial Prize in Economics for his work in Prospect theory. Richard O. Buckius, engineer, Bachelor's in Mechanical Engineering '72, Masters '73, PhD '75, currently Chief Operating Officer of the National Science Foundation. Edward P. Tryon (PhD 1967) is the physicist who first