1. Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
2. Department of Chemistry, Cape Breton University, Sydney, Nova Scotia B1P 6L2, Canada
3. Department of Biology, Cape Breton University, Sydney, Nova Scotia B1P 6L2, Canada
4. Department of Medical Physics, Grand River Regional Cancer Centre, Kitchener, Ontario N2G 1G3, Canada