Henson School of Science and Technology

Department of Biological Sciences

Faculty Research Summaries

Dr. Ann Barse I study parasites of estuarine and marine fishes, and a few invertebrates as well, from an ecological/evolutionary perspective. Examples of projects are: · Parasites of the American eel, Anguilla rostrata, in Chesapeake Bay and coastal bays in Maryland. Students are looking at an exotic nematode parasite that lives in the swim bladder, as well as intestinal parasite communities. · Monogenea (ectoparasitic flatworms) of large oceanic game fishes (marlins and tunas). We look for new host and geographic records of parasite-host associations. · Trematode (endoparasitic flatworms) communities of the mud snail. We investigate species richness, and seasonal and spatial patterns in parasite distributions. · Turbellarian (commensal flatworms) communities of horseshoe crabs in Delaware Bay.

Dr. Chris Briand My main research focuses on historical ecology. The natural environment of the Coastal Plain of the Mid-Atlantic region has undergone dramatic changes over the past ca 350 yrs due to deforestation and intensive agriculture. In collaboration with Mike Folkoff (Geography) I am investigating the composition of pre-settlement forests of the Eastern Shore of Maryland using witness tree data present in the original 17th century metes and bounds surveys. Witness trees were also used as markers in metes and bounds surveys on some Caribbean islands such as the Bahamas and St. Vincent. In January 2006 I plan on a preliminary visit to Nassau to assess the extent of their survey records. I am also interested in how human disturbance has affected the chemical and physical characteristics of soils in the Mid-Atlantic. Cemeteries in farm fields on the Eastern Shore provide potentially valuable markers for measuring anthropomorphic induced changes, as farmers have left them relatively undisturbed by agricultural practices. In collaboration with Sam Geleta (Biology), Mike Folkoff and Brent Zaprowski (Geography) I am investigating the influence of farming on regional soils. Another of my interests in economic botany, and I have recently (2005) published a paper in Huntia entitled “The Common Persimmon (Diospyros virginiana L.): The History of an Underutilized Fruit-Tree (16th - 19th Centuries).”

Dr. Elizabeth Emmert My research focuses on Bdellovibrio bacteriovorus, which is a bacterium that can only grow and divide inside other prey bacteria. One current project is examining the predation preferences of B. bacteriovorus when given the choice among prey bacteria and determining the basis for differential predation. I am also interested in investigating why B. bacteriovorus is dependent on prey bacteria for growth. Other interests include the effects of B. bacteriovorus on microbial communities and the potential use of B. bacteriovorus to control bacterial pathogens. If this sounds interesting to you, please feel free to contact me about research opportunities in my lab.

Dr. Les Erickson My lab studies gene function. We are mainly focusing on better understanding plant genes involved in stress signaling. This is a collaborative effort with Dr. Glenda Gillaspy's lab at Virginia Tech.  This project involves numerous molecular and biochemical techniques such as gene cloning, PCR, RT-PCR, DNA microarray analysis, and protein purification.

Dr. Mark Frana Working together with Dr. Venso and in conjunction with the Maryland Department of the Environment (MDE), our laboratory is involved with Bacterial Source Tracking (BST). The area of study known as BST is designed to identify the specific sources of fecal bacteria found in environmental water samples, e.g. drinking, recreational and/or shellfish harvesting waters. Increased levels of fecal bacteria are associated with increased health risks. Possible sources of fecal contamination in environmental waters include failing septic systems or overflow from sewage treatment plants (human) or runoff after rainfall (livestock, wildlife and/or pets). Identification of the specific sources of fecal bacteria in these waters will help guide regulatory agencies as they attempt to control this contamination. Our laboratory is using several different methods in BST analysis including, gel electrophoresis, antibiotic resistance profiling and carbon source utilization. Data is collected and analyzed statistically to determine the probable sources of fecal bacteria found in water samples. The field samples for our projects are collected by MDE staff and delivered to our SU lab. Students from Biology, Environmental Health, and Mathematics have all participated in various aspects of the lab analysis. Most recently, we’ve begun a collaborative project with Dr. Williams in an attempt to determine if bacterial membrane lipid composition comparisons can be used as another viable BST method.

Dr. Steve Gehnrich My current research centers around the enzyme carbonic anhydrase, which catalyzes the formation of bicarbonate from carbon dioxide and water. We have been using techniques of molecular biology to investigate the role of carbonic anhydrase in the mineralization of crustacean shells after molting. We are particularly interested in studying alterations in the expression of carbonic anhydrase, and of its specific isoforms, throughout the molt cycle. The role of carbonic anhydrase in mineralization has been debated for many years, and I think a molecular approach will offer valuable insights into its cellular location and function. I am also involved in collaborative research projects with investigators from other universities on the function of carbonic anhydrase in fish kidney and crab gill. I am also interested in mitochondrial physiology, particularly the significance of mitochondrial dysfunction in stroke, Parkinson's, and other neurodegenerative diseases.

Dr. Samuel Geleta My research involves: soil fertility and plant nutrient management; soil-plant-water relations; and soil and crop management impact on regional environmental quality (soil and water quality). Depending on the area of their interest, students will have the opportunity to work in wide area of environmental issues related to plants, soil, and water. Currently we have an ongoing research project titled "Phosphorus Management in Major Vegetable Crops Grown on High Phosphorus Soils of the Maryland Eastern Shore". This project is funded for three years by the Maryland Department of the Environment.

Dr. Paul Grecay I am currently involved in research which deals broadly with the trophic or feeding ecology of juvenile marine and estuarine fishes. I am currently investigating the effects of a variety of dissolved oxygen regimes on the activity and growth of juvenile estuarine fishes. In addition, I am studying the interaction of turbidity and light level on feeding and growth of southern flounder (Paralichthys lethostigma) and summer flounder, (Paralichthys dentatus). As a visiting scientist at the University of Kyoto's Fisheries Research Laboratory in Maizuru, Japan, in Spring of 1999, I began investigating the interaction of temperature and salinity in growth of juvenile Japanese flounder and the relationship of these effects to populations collected from several locations along coastal Japan. Further experiments are planned for comparison with a more northerly population (Hokkaido). Lastly, I am developing a project with the assistance of SU students to investigate the influence of body size and search field on feeding ability in winter flounder (Pseudopleuronectes americanus) under turbid conditions.

Dr. Aaron Hogue  Broadly speaking, I am interested in mammalogy, conservation biology, ecomorphology, and vertebrate evolution. Previous topics I have explored include the evolution of marsupial dental and jaw form in relation to diet, and the evolution of high crowned (hypsodont) teeth in response to dietary abrasives. Recently I have shifted my focus away from evolutionary and ecomorphological research to more of an emphasis on conservation (though I am still interested in supervising motivated students wishing to do research in these other areas). In particular, my primary focus at present is on the conservation of endangered and threatened mammals worldwide, and the effects of habitat fragmentation, logging regimes, and biological corridors on mammal community structure and overall biodiversity in forested habitats. Work in my lab currently focuses on the conservation of the endangered Delmarva Fox Squirrel (DFS). Specifically, we are working with Mike Scott (in Geography) and the U.S. Fish and Wildlife Service on a project attempting to identify potential DFS habitat on the lower eastern shore of Maryland. We are using aerial LiDAR (Light Detection And Ranging) data collected by the state of Maryland to locate and map all tall, mature forests on the lower shore. We are then visiting select sites to measure key characteristics of forest structure to assess its potential as DFS habitat. These data can then be used by the USFWS, Maryland DNR, and other interested parties to establish corridors connecting isolated DFS populations, as well as identify sites for future DFS reintroductions.

Dr. Mark Holland My lab is studying the relationship between a common phylloplane bacterium, Methylobacterium, and its plant hosts. Over the past several years, we have demonstrated that these bacteria enhance seed germination, stimulate root and plant growth, and can be used to boost yield in some crop plants. All of these effects seem to be due to production of a plant growth regulator (plant hormone) by the bacteria. We have also demonstrated that the bacteria participate in plant metabolism by consuming plant waste products and producing metabolites useful to the plant. Several students are usually involved in this work every semester, and students are encouraged to stop by my office or lab to discuss opportunities.

Drs. Kimberly and Richard Hunter  The main focus of our lab is investigating why polyploidy confers an advantage to plants. Our approaches to the question are molecular and physiological. Some of the polyploid plants that we have students investigating are Larrea (plant in the southwest and South America), Phragmites australis (wetland polyploid), and alfalfa (common crop plant). We also investigate the population genetics of different plant species. We are working on two native orchids of this area (Tipularia and Cypripedium), and now we are starting work on a threatened barrier island plant, Seabeach Amaranth. The characteristic we are looking for in a research student is the willingness to do whatever is needed. This will include literature searches, writing reprint request cards, measuring guard cells, doing PCRs, extracting DNA, watering plants in the greenhouse, painting the lab, cleaning the lab or anything we can think of. If this sort of thing sounds interesting to you come and see us. Research is Fun.

Dr. Ellen Lawler In a collaborative project with Dr. Folkoff, we are using computer mapping (GIS) techniques to study the temporal and spatial patterns of waterfowl wintering in the Chesapeake Bay. We are working with data that's been collected by the DNR (via aerial surveys) since the early 1950's. In the past we have had one Bio student and one Geog student working together, which is ideal. The students work on one or two species for their specific segment of the project. I'd like for students to combine a semester of readings with GEOG 200 and then take 415 the following semester.

Dr. Joan Maloof I study the reproductive biology of plants. Determining the mating system, the pollinators, and the nectar production levels are just a few components of my research. I am particularly interested in rare plants. I currently have a project available for a student interested in plant identification. I would prefer a sophomore who has dependable transportation and a basic familiarity with common plant species.

Dr. Judith Stribling My research interests center around sediment biogeochemistry in wetlands, including investigating nutrient dynamics and plant-sediment interactions. I am especially interested in how plants modify their environments in the stressful sediments of wetlands. I also am involved in wetland restoration, specifically monitoring a project within a relict, drained cypress swamp that is being re-flooded.  I have also participated in evaluation of Maryland’s wetland management in the Coastal Bays, including Assateague Island.

Dr. Ryan Taylor My research takes an integrative approach to animal behavior.  I am especially interested in the role of multimodal signal assessment in sexual selection.  It is becoming increasingly clear that females evaluate potential mates using information transmitted across multiple sensory modalities (e.g. vocalizations plus visual courtship displays).  How females evaluate these multiple pieces of information, however, remains poorly understood.  My research incorporates studies of behavior, neurobiology, and morphology to understand how female brains process multimodal signals and how this processing is translated into mate choice.  By examining how multiple signals affect mate choice, I hope to gain a better understanding of the process by which female choice drives the evolution of male traits. For the past several years my research has focused on frogs.  I am currently spending a portion of my summers working at the Smithsonian Tropical Research Institute in Panama where I study the túngara frog.  In addition, I am conducting experiments with North American Hylid frogs such as the squirrel treefrog and the green treefrog.  I am also broadly interested in ecology, conservation biology, functional morphology, and philosophy of science. Opportunities for students in my lab include, but are not limited to:  investigating mate choice behavior in a tropical frog (research conducted in Panama) investigating mate choice behavior in treefrogs (research conducted in Maryland) investigating strategies of male-male competition for mates (research conducted in Panama or Maryland) the study of visual capabilities of treefrogs (research conducted in Maryland) the study the neurobiology of signal processing (Panama and Maryland) recording and analyzing treefrog vocalizations (Maryland) conducting field monitoring studies on Maryland amphibians

Dr. Elichia Venso  My research focus is on 1) the determination the occurrence of environmental radioactivity, specifically uranium, radium and radon in ground and surface waters; 2) air pollution, particularly ground level ozone and radon in residential air; 3) DNA fingerprinting of E. coli bacteria in natural waters. 4) I also have an interest in air pollution in the work place.

Dr. Eugene Williams Research in my lab centers on the biology, biochemistry, and biophysics of the membranes of animal cells, especially as they relate to the progression of cancer and to the survival of animals in extreme environments. We are particularly interested in how individual membrane lipids contribute to overall cell and membrane function. Current work concentrates on the curious properties of certain membrane-associated fatty acids, the omega-3 fatty acids. These fatty acids inhibit the growth of tumor cells in mammals and are also involved in allowing non-mammalian cells (and therefore animals) to acclimate to cold. A major focus is determining the mechanisms underlying the ability of DHA (one of the omega-3 fatty acids) to induce apoptosis, or programmed cell death, in leukemia cells. Other projects include an examination of how these fatty acids affect the metastatic capacity of melanoma cells and changes in the expression of genes for enzymes of phospholipid metabolism fish cells cultured in the cold.