Australian nobel laureate J. Robin Warren holds the joint 2005 Nobel Prize for Medicine at the Concert Hall in Stockholm December 10, 2005. The Nobel Assembly at the Karolinska Institute awarded the Nobel Prize in Physiology or Medicine jointly to Australians Barry J. Marshall and J. Robin Warren for their discovery of "the bacterium Helicobacter pylori and its role in gastritis and peptic ulcer disease". REUTERS/Pawel Kopczynski