Complex sentence: Dr. Mackie is a Fellow of the American Association of Physicists in Medicine and a member at large of that organization's Science Council and is the Vice-Chair of the University of Wisconsin-Madison Calibration Laboratory.
Split into simpler sentences: Dr. Mackie is a Fellow of the American Association of Physicists in Medicine and a member at large of that organization's Science Council. He is also the Vice-Chair of the University of Wisconsin-Madison Calibration Laboratory.