Jean F. Letessier has been CNRS researcher at the University of Paris since 1978. Prior to that he worked at the Institut de Physique Nucleaire, Orsay where he obtained his thesis on Hyperon-Nucleon Interaction in 1970, under the direction of Prof. R. Vinh Mau, and was a teaching assistant at the University of Bordeaux. Since 1972 he has made numerous contributions to the research area of thermal particle production and applied mathematics. Johann Rafelski obtained his Ph.D. in 1973 and has been Professor of Physics at the University of Arizona since 1987. He teaches theoretical subatomic physics at both undergraduate and graduate level. Prior to this, he held a Chair at Theoretical Physics at University of Cape Town, and has been associate Professor of Theoretical Physics at University Frankfurt. He worked at the CERN laboratory in Geneva in various functions since 1977, and has been instrumental in the development of the relativistic heavy ion experimental program.