First Author:   Robert Sproule Bishop's University ra_sproule@shaw.ca   2600 College Street Sherbrooke, J1M 1Z7, Canada   819-822-9600(Phone) 819-822-9600(Fax) http://www.ubishops.ca/faculty/sproule/ Second Author: Calin Valsan Bishop's University cvalsan@ubishops.ca   Sherbrooke, J1M 1Z7, Canada   819-822-9600(Phone) 819-822-9661(Fax) http://