1. Department of Zoophysiology, Aarhus University, 8000 Aarhus C, Denmark
2. School of Biomedical Sciences, University of Leeds, Leeds, UK
3. Department of Zoology, and Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC 45, Canada
4. Department of Biological Sciences, Ohio University, Athens, Ohio, USA
5. Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, USA
6. Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden