Yale University Professor James Rothman, 62, the co-awardee of the 2013 Nobel Prize for Medicine, speaks at a news conference at Yale University in New Haven, Connecticut October 7, 2013. Three U.S.-based scientists won the Nobel medicine prize on Monday for plotting how vital materials such as hormones and brain chemicals are transported within cells and secreted to act on the body, giving insight into diseases such as diabetes and Alzheimer's. Americans Rothman, Randy Schekman, 64, and German-born Thomas Suedhof, 57, separately mapped out one of the body's critical networks that uses tiny bubbles known as vesicles to ferry chemicals such as insulin within cells. REUTERS/Adrees Latif (UNITED STATES - Tags: HEALTH SCIENCE TECHNOLOGY)