FACULTY

RESEARCH

My research interests include: the genetic structure of natural bacterial populations; the evolution of pathogenic forms of bacteria; molecular epidemiology; and invasive bacterial pathogens. This includes investigating the roles of selection, mutation, and recombination in the emergence/reemergence of pathogenic forms, and how large genomic insertions or deletions impact phenotypic virulence characteristics.

I am interested in morphology, ecology, behavior, and evolution. My research focus is Vertebrate Biology, with special emphasis on amphibians and reptiles. With the use of comparative approaches, I examine morphological, ecological, and behavioral specializations that explain the current demographic status of species and communities. Given the present biodiversity crisis, it is important to take a proactive stand, and generate models that predict the fate of species under pressure from human disturbance. My goal is to establish a long term and comparative study to address demographics and conservation of Pennsylvania's Herpetofauna. In my research strategy, I combine traditional herpetological and field ecology techniques, as well as, remote sensing (GPI), and molecular biology. Currently, I am developing permanent lines of professional interaction with research institutions in Florida (USA), Andalucia (Spain), and Murcia (Spain).

I am involved in a number of collaborative research projects with SU faculty and the United States Army Medical Research Institute of Infectious Diseases (USAMRIID) at Ft. Detrick. One project is focused on elucidating the role the ubiquitous enzyme, calpain, on invasion and migration of brain tumors. The hope is that by studying one mechanism involved in regulating tumor invasion in the brain, new treatment paradigms can be generated that will prolong the life of patients suffering from glioblastomas. In addition, I am involved in an ongoing collaborative effort with Drs. Lehman, Patrie and Stewart to determine the prevalence of the causative agents of Lyme disease, human granulocytic ehrlichiosis (HGE), human monocytic ehrlichiosis (HME) and tick borne viral encephalitis in ticks and blood collected from hunter killed deer in South Central Pennsylvania. Finally, I am collaborating with Dr. Robert Ulrich at USAMRIID investigating the role of autophagy in the immune response to S. pyogenes. My studies involve the use of cellular, molecular and immunodiagnostic techniques and will give students the opportunity to gain expertise in techniques commonly used in biotechnology and biomedical research.

Dr. Todd Hurd
Associate Professor of Biology
(Ecosystems Ecology)
B.S. SUNY, Environmental and Forest Biology
Ph.D. SUNY, Environmental and Forest Biology

My research interests are mostly in ecosystem and plant community ecology, and include
1) rates and ecological effects of biological nitrogen fixation; 2) sources and ecological effects of nutrient additions to spring creeks;
3) effects of nutrient additions to forest and wetland ecosystems; and 4) hydrological interactions with chemistry and communities of wetland and aquatic ecosystems. Current projects include: estimating ecosystem inputs of nitrogen from nitrogen-fixing black locust (Robinia psuedoacacia); use of aquatic plants and stable isotopes to indicate nutrient enrichment and sources of organic matter to local spring creeks; hydrological studies of local spring creeks, and isotopic tracing of heron predation on stocked trout.

My main area of current research is to describe the vegetation of seasonal ponds in Pennsylvania. This project has involved the participation of several undergraduate and graduate students. In addition, I have been working with a colleague to analyze the Pennsylvania populations of shooting stars (Dodecatheon, Primulaceae) in order to elucidate their relationship to the two species that are reported to occur in this state. Also, I have had many contracts for summer field work with the Pennsylvania Natural Heritage Program and several environmental consulting firms to describe populations of rare plant species and plant communities in various parts of Pennsylvania. Finally, I am the principal curator of the University Greenhouse and Herbarium and encourage student participation in maintaining and developing these facilities.

My research interests are in the areas of aquatic ecology and conservation biology. Some of my specific interests include: invasion dynamics and the effects of invaders on aquatic communities; the effects of human and natural disturbance on stream communities; conservation ecology of freshwater invertebrates, particularly crayfishes; and the structure and dynamics of aquatic food webs. I am also open to student interests in any area of aquatic ecology.

Current research centers on histochemical and EM studies on cellular/tissue effects of environmental toxins and cellular adaptation to sublethal toxication involving the cytochrome P450 system. Interests also include studying the effects of nutrition or aging at the cellular/tissue level. Undergraduate participation or independent projects are encouraged as well as graduate research.

My primary research interests are at the interface of ecology and evolutionary biology as I strive to understand adaptive evolution in plants, the forces driving plant population differentiation, and variation in plant-insect interactions across populations. To address these questions I use a combination of field studies, greenhouse experiments, and molecular techniques. Studies in my lab include: 1) Examining plant adaptations by measuring natural selection on plant traits by various selective agents such as pollinators, herbivores, and different environmental conditions, 2) Studying the reproductive biology of plant species and factors limiting reproduction in rare and threatened plant species, 3) Examining how plants and pollinators are interacting at the community level and how these plant-pollinator interactions change across habitats, and 4) Measuring gene flow, genetic drift, genetic diversity, and population differentiation of both widespread and rare plant species using population genetics. I welcome students interested in doing research on any of the projects listed above or on other topics related to plant ecology and evolution.