This award will support U.S. participation in a week long workshop in theoretical high energy physics, co-organized by Dr. William McGlinn, University of Notre Dame, and Prof. L. O'Raifeartaigh, Dublin Institute for Advanced Studies, Dublin, Ireland. The workshop will take place in Dublin in May 1989. Theoretical high energy physics is a rapidly moving field with major contributors in both the U.S. and Europe. This seminar will provide an opportunity for leading researchers to become familiar with each other's work. Specifically the discussions will focus on new results and future trends in the theory of fundamental interactions (electromagnetism, gravitation and nuclear forces) with emphasis on the unification of these interactions, in particular in view of the developments in string theory.