The 2011 Ig Nobel winners,

awarded Thursday at Harvard University by the Annals of Improbable Research magazine:

PHYSIOLOGY: Anna Wilkinson, Natalie Sebanz, Isabella Mandl and Ludwig Huber for their study "No Evidence of Contagious Yawning in the Red-Footed Tortoise."

CHEMISTRY: Makoto Imai, Naoki Urushihata, Hideki Tanemura, Yukinobu Tajima, Hideaki Goto, Koichiro Mizoguchi and Junichi Murakami for their wasabi fire alarm.

MEDICINE: Matthew Lewis, Peter Snyder, Robert Feldman, Robert Pietrzak, David Darby, Paul Maruff along with Mirjam Tuk, Debra Trampe and Luk Warlop for studying the effects of holding in urine.

PSYCHOLOGY: Karl Halvor Teigen for trying to understand why people sigh.

LITERATURE: John Perry for his theory of procrastination: To be a high achiever, always work on something important, using it as a way to avoid doing something that's even more important.

BIOLOGY: Daryll Gwynne and David Rentz for discovering that certain kinds of beetles try to mate with certain kinds of Australian beer bottles.

PHYSICS: Philippe Perrin, Cyril Perrot, Dominique Deviterne, Bruno Ragaru and Herman Kingma for trying to determine why discus throwers become dizzy, and why hammer throwers don't.

MATHEMATICS: Assorted doomsday predictors throughout history for teaching the world to be careful when making mathematical assumptions and calculations.

PEACE: Arturas Zuokas for solving the problem of illegally parked cars by crushing them with an armored vehicle.

PUBLIC SAFETY: John Senders for his experiments in which a driver on a major highway repeatedly has a visor flapped down over his face.