1. Department of Civil and Environmental Engineering, University of Virginia, PO Box 400742, 351 McCormick Road, Thornton Hall, Rm. B228, Charlottesville, VA 22908, USA
2. Department of Civil Engineering, University of Rhode Island, Bliss Hall 213, Kingston, RI 02881, USA
3. Department of Public Health Sciences, Public Health Sciences Hospital West, University of Virginia, PO Box 800717, 3181, Charlottesville, VA, USA
4. Department of Microbiology, University of Venda, Department of Chemistry, University of Venda, Private Bag X5050, Thohoyandou 0950, Limpopo Province, South Africa
5. Department of Medicine, University of Virginia, PO Box 801379, Charlottesville, VA, USA