What is Prana? Yoga Talk and Demonstration, 6:30 p.m., Humphrey Memorial Chapel. P.J. Heffernan, authorized Ashtanga yoga instructor and owner of PJ’s Yoga Shala in Waukesha, will discuss the energetic power of Ashtanga yoga. Several of his students will demonstrate the various aspects of this ancient tradition. Questions and conversation will follow. Students who attend will earn a convocation point.