First Author:   Robert Sproule Bishop's University ra_sproule@shaw.ca   2600 College Street Sherbrooke, J1M 0C8, Canada   819-822-9600(Phone) 819-822-9600(Fax) http://www.ubishops.ca/faculty/sproule/ Second Author: Ambrose Leung Bishop's University aleung@ubishops.ca   2600 College Street Sherbrooke, J1M 0C8, Canada   819-822-9600(Phone) 819-822-9661(Fax)