| • | Chairman, Biology Department, NM Tech, 1998-2004. |
| • | Professor of Biology NM Tech 1984-present. |
| • | Sabbatical leave with Dr John Dedman, Department of Cell Biology, University of Texas health Science Center, Houston TX, July 1986-August 1987. |
| • | Dean of Graduate Studies, New Mexico Tech, Socorro, NM June 1986. Resumed after sabbatical leave, August 1987-1997. |
| • | Chairman, Biology Department, NM Tech, Socorro, NM July 1981-August 1986. |
| • | Adjunct research Associate Professor, Department of Medicine, University of New Mexico, Albuquerque 1978-present. |
| • | Sabbatical leave with Dr S. S. Solomon, Endocrine and Metabolism Section, VA Medical Center, Memphis TN, July 1979-July 1980. |
| • | Associate Professor of Biology, NM Tech, Socorro, NM. August 1973-May 1984. |
| • | Assistant Professor of Biology, NM Tech, Socorro, NM. August 1973-My 1978 |
| • | Postdoctoral Fellow with Dr w Y Chueng, St Jude's Research Hospital, Memphis TN. April 1972. |
| • | Research Physiologist (Capt US Army) Physiology Laboratory, US Army Reserach Institute of Environmental Medicine, Natlick MA. June 1969-April 1972. |