1. Department of Chemical and Biological Sciences, Youngstown State University, 4042 Ward Beecher Hall, 100 Lincoln Avenue, Youngstown, OH 44555, USA
2. Department of Biological Sciences, University of Pittsburgh, A234 Langley Hall, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA
3. USDA Forest Service, Northern Research Station, Forestry Sciences Lab, P.O. Box 267, Irvine, PA 16329, USA