1. Guelph Molecular Supercentre, Laboratory Services Division, University of Guelph, Guelph, Ontario, Canada N1H 8J71;
2. Biotronics Technologies Corp., Lowell, Massachusetts 018512;
3. Health of Animals Laboratory, Health Canada, Guelph, Ontario, Canada N1G 3W43; and
4. Office of Research, University of Guelph, Guelph, Ontario, Canada N1G 2W14