1. US Environmental Protection Agency, Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Exposure , Duluth, Minnesota 55804, USA
2. Oak Ridge Institute for Science and Education , Oak Ridge, Tennessee 37830, USA
3. Integrated Biological Sciences Program, University of Minnesota-Duluth , Duluth, Minnesota 55804, USA
4. Spec-Pro Professional Services , Duluth, Minnesota 55804, USA