Professor

Joined the faculty: 1978

Affiliations:

Teaching: MS1 PBL, CCMD 730, BIOC 493/531, BIOC 705

Room: 3103-A
Phone: (304) 293-7758
Fax: (304) 293-6846
Email: mwimmer@hsc.wvu.edu

The laboratory research of my first 20 years at West Virginia University involved primarily two main areas, the first being enzyme mechanisms, and the second, the analysis and environmental fate of pesticides.  The enzyme research focused on the mechanism by which plant chloroplasts convert light energy into the chemical energy of ATP.  The approach involved the use of oxygen-18-labeled phosphate compounds and water to study oxygen exchange reactions used in characterizing the chemical steps carried out by the light-dependent chloroplast ATP synthase.  The effects of light intensity and inhibitors of the process were studied.  Results added support to Boyer’s “binding change” mechanism of energy coupling.  The WVU Mass Spectrometry Center, formerly in the Department of Biochemistry, was established to conduct the sample analyses.  [Research, including a shared instrumentation award to set up the mass spec, was funded by NIH.]

Our main pesticide research project involved diflubenzuron (trade name Dimilin) used in Appalachian forests for control of the gypsy moth, a forest defoliator.  My laboratory developed a unique method for analyzing this pesticide, enabling rapid and sensitive analyses to be done.  The approach takes advantage of the thermal breakdown of diflubenzuron in the heat of the gas chromatograph.  Using deuterated diflubenzuron as an internal standard, and mass spectrometry to detect specific ions, analyses could be done without purification of leaf extracts, and with only partial purification of more complex extracts from ground litter.  We found diflubenzuron to be persistent in the forest ecosystem.  An average of 40% of the original amount after spray is still found on leaves at leaf fall, and the pesticide is detected in ground litter for over 17 months post spray, with much added at the time of leaf fall from that remaining on the overlying foliage.  The residue analyses were part of a comprehensive study of the non-target impacts of Dimilin on the Appalachian forest ecosystem.  Impacts were consistent with its environmental persistence.  The research has lead to increased use of alternate pesticides.  [Research funded by USDA Forest Service, with Mass Spectrometry Center upgrade funded by a shared instrumentation award from NSF.]

In 1998, I closed my research laboratory to focus on teaching and educational scholarship, taking on more lecturing and assuming directorship for several courses: Problem-Based Learning (PBL) for our 1^st-year medical students; Biochemistry 493/531, General Biochemistry for 1^st-year Pharmacy students and other health professional undergraduates; and Biochemistry 705, General Biochemistry for 1^st-year Dental students.  Scholarly activities have included development of Concept Mapping exercises in PBL, as well as new cases and methods of case, student, and facilitator evaluations; curriculum design in the dental and pharmacy courses, including addition of clinical correlations; development of Friday Sessions  in Bioc 705 on dental-related biochemistry and nutrition; and basic science curriculum revision in the School of Dentistry.

  References:

• “Using Problem-based Learning Evaluations to Improve Facilitator Performance and Student Learning.” Scott Cottrell, Mary Wimmer, Barry Linger, James Shumway. Journal of the International Association of Medical Science Educators, Journal of the International Association of Medical Science Educators, 14:2, 58‑63 (2005).
   
• “Innovation in Teaching Dental Biochemistry at West Virginia University.” Abstract/Poster.  American Dental Education Association (ADEA) Annual Meeting, San Antonio, Tx (2003).
   
• Part D: “Residue levels and persistence,” Chapter 16: Terrestrial environment. Mary J. Wimmer. In Effects of Diflubenzuron on Non-target Organisms in Broadleaf Forested Watersheds in the Northeast. USDA Forest Service Technical Transfer publication FHM-NC-05-95 (1995).
   
• "Persistence of Diflubenzuron on Appalachian Forest Leaves after Aerial Application of Dimilin." Mary J. Wimmer, Robert R. Smith , Deborah L. Wellings, Steven R. Toney, David C. Faber, Jerry E. Miracle, Jason T. Carnes, and A. Ben Rutherford, J. Agric. Food Chem. 41, 2184-2190 (1993).
   
• "Analysis of Diflubenzuron by Gas Chromatography/Mass Spectrometry using Deuterated Diflubenzuron as Internal Standard." Mary J. Wimmer, Robert R. Smith and Jeffrey P. Jones, J.Agric. Food Chem. 39, 280-286 (1991).
   
• Two Types of Kinetic Regulation of the Activated ATPase in the Chloroplast Photophosphorylation System. Paula A. Sherman and Mary J. Wimmer, J. Biol. Chem. 257, 7012-7017 (1982).