Yale University Professor James Rothman, 62, the co-awardee of the 2013 Nobel Prize for Medicine, gives a lecture to students at Yale in New Haven, Connecticut on October 7, 2013. Students encircled Rothman's podium with trophies ahead of his arrival in celebration of the award. 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 James Rothman, 62, 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. Medicine is the first of the Nobel prizes awarded each year. REUTERS/Michelle McLoughlin (UNITED STATES - Tags: HEALTH SCIENCE TECHNOLOGY)