Dissertation - Michael Becker

For saving my life, I thank Dr. Deborah Smith. Her powers of healing far exceededthose of the medications she administered. I am forever indebted to Kathryn Flack andMatt Wolf, who were there for me when I needed them most. They are true friends. Iam grateful to John McCarthy and Lisa Selkirk for their support in difficult times, and forhelping minimize the impact of my illness on my graduate career.I thank my parents Yigal and Ada Becker, for believing that with constant love andunconditional support I could parallel their level of education. Thanks also to my brothers,my aunts, my uncles, my cousins, and to Nir, Yoav, and Vered. I thank my grandmotherRivka Shershevsky for her love and above all for her patience.Lastly, I thank Tom, for his love and companionship, in sickness and in health, and forgiving me Tulip.vii