AMHERST, Mass. - Barbara Osborne, of the University of Massachusetts Amherst veterinary and animal sciences department, will give a Distinguished Faculty Lecture, "The Short Life and Timely Death of the White Blood Cell," at 4 p.m., on Wed. April 2, in the Massachusetts Room at the Mullins Center. Her talk is the fourth and final event in this academic year''s Distinguished Faculty Lecture series. The talk is free and the public is welcome. A reception will follow. All faculty members in the series receive a Chancellor''s Medal following their lectures. The Chancellor''s Medal is the highest honor bestowed on individuals for exemplary and extraordinary service to the University.