Sgt. Joshua P. Ott, 24, a martial arts instructor trainer based out of Quantico, Va., answers a question for Alexandra T. Leach, 22, a biology-major from Gurnee, Ill., during a self defense class at the Martial Arts Center of Education, University of Chicago May 14. The class consisted of 15 techniques and was given to three sororities from the university. - Sgt. Joshua P. Ott, 24, a martial arts instructor trainer based out of Quantico, Va., answers a question for Alexandra T. Leach, 22, a biology-major from Gurnee, Ill., during a self defense class at the Martial Arts Center of Education, University of Chicago May 14. The class consisted of 15 techniques and was given to three sororities from the university.