Culture of South Africa originated in South Africa. The first human-to-human heart transplant was performed by cardiac surgeon Christiaan Barnard at Groote Schuur Hospital in December 1967. Max Theiler developed a vaccine against Yellow Fever, Allan McLeod Cormack pioneered x-ray Computed tomography, and Aaron Klug developed crystallographic electron microscopy techniques. These advancements were all (with the exception of that of Barnard) recognised with Nobel Prizes. Sydney Brenner won most recently, in 2002, for his pioneering work in molecular biology. Mark Shuttleworth founded an early Internet security company Thawte, that was subsequently bought out by world-leader VeriSign. South Africa has cultivated a burgeoning astronomy community.
Nobel Prize controversies Erwin Hahn for his contribution to the principles of spin echoes. The 2000 prize went to Arvid Carlsson, Paul Greengard, and Eric R. Kandel, "for their discoveries concerning signal transduction in the nervous system". The award caused many neuroscientists to protest that Oleh Hornykiewicz, who helped pioneer the dopamine replacement treatment for Parkinson's disease, was left out, and that Hornykiewicz's research provided a foundation for the honorees' success. The Nobel Prize for Physiology or Medicine was awarded in 1998 to Robert Furchgott, Louis Ignarro and Ferid Murad "for their discoveries concerning nitric oxide as a signalling molecule in the cardiovascular