Workshop RO and related concepts: methods and illustration. 29-30-31st October 2008, Paris, France. INRA, CIRAD - on behalf of EDEN - and other colleagues organise a workshop on R_0. The workshop will focus on one of the most important concepts in epidemiology, population dynamics and ecology provided by the mathematical thinking, the basic reproductive number, R, and its associated parameters. This meeting offers the opportunity to learn more about this concept and related ones, the mathematical methods they involve and their practical implications.