Using geographic information systems for exposure assessment in environmental epidemiology studies The Web site also includes links to curriculum projects, guides to getting started with GIS, and information on software (ESRI's ArcVoyager Special Edition is free) used to bring GIS to schools. High-tech maps: how to get here from there.
John Chrysostom. John Chrysostom (347 - 407) was a notable Christian bishop and preacher from the 4th and 5th centuries in Syria and Constantinople. He is famous for eloquence in public speaking and his denunciation of abuse of authority in the Church and in the Roman Empire of the time.
John Snow was an English physician and a leader in the adoption of anaesthesia and medical hygiene. He is considered one of the fathers of modern epidemiology, in part because of his work in tracing the source of a cholera outbreak in Soho, London, in 1854. His findings inspired fundamental changes in the water and waste systems of London, which led to similar changes in other cities, and a significant improvement in general public health around the world.