Biological Sciences
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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 (lab page)
Signal transduction pathways that involve second-messenger molecules like inositol triphosphate (IP3) regulate specific genes in response to environmental changes involving light, water, nutrient levels, etc. We seek to better understand the mechanisms involved in IP3-mediated signaling in plants. Both animal and plant cells contain numerous IP3 phosphatases, enzymes that regulate IP3 signal transduction by degrading IP3. In humans, defects in genes encoding inositol phosphatases are observed in diseases such as Lowe syndrome, cancer, and myotubular myopathy, and certain IP3 phosphatases are targets of lithium, the primary treatment for Bipolar Disorder. In our research using the model plant Arabidopsis thaliana, we have identified proteins that physically interact with an IP3 phosphatase. In collaboration with
Glenda Gillaspy's laboratory at Virginia Tech, we have shown that IP3 signaling pathways "cross talk" with other signaling pathways involving nutrient availability and stress pathways regulated by the hormone abscisic acid. We are currently working toward better understanding the mechanisms involved in this signaling pathway cross-talk.

Dr. Mark Frana
Working together 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  (CV)
My current research centers on transcribing and studying the letters of Henry Callister, a colonial resident of the Eastern Shore of Maryland, who had a strong interest in natural history. In one letter Callister describes a number of local species including fishing hawk (osprey), summer duck (wood duck), hummingbird, opossum, flying squirrel and tumbleturd (dung beetle) and lists additional species he observed in Maryland. His “Swallow dissertation” includes his thoughts on bird migration and on the ability of non-human species to adapt to their particular environment (an idea advanced for that time). He also recognized that wild animals (such as turkeys) were able to breed with their domestic counterparts and that the offspring exhibited a mix of characteristics of the two parents. He even suggested that in certain situations, some individuals could give rise to new species. We are continuing to transcribe additional Callister letters and trying to determine sources that may have influenced him. We are also looking for other naturalists active in Maryland during the colonial period although there appears to be relatively few compared to other mid-Atlantic colonies.
 

Dr. Eric Liebgold  (CV, Lab page)

My students and I ask ecological and evolutionary questions relating to the interplay between animal movements and genetic structure. We use mark-recapture field studies, field experiments, and genetic analyses with microsatellite DNA in our research. My students and I are currently working on a variety of projects involving the red-backed salamander, Plethodon cinereus, with a focus on sex-biased dispersal and maintenance of color polymorphism. We are also working on a project investigating the ecology of ground-nesting birds with Dr. Tami Ransom in the Environmental Studies Department. Our focus is on foraging and nesting success in different habitats as well as the influence of species- and site-specific factors on genetic structure.

Dr. Dana Price  (CV, Lab Page)
My current research is focused on conducting a bioinventory of Maryland Scarabaeoidea in all 23 counties with an emphasis on the Eastern Shore.  Collections began in Wicomico and Worcester Counties in 2009 and we have since expended our collections throughout Maryland.  Current collection materials will be further supplemented with museum collections (National Museum of Natural History and Nebraska Museum of Insects), USDA holdings, and personal collections from Maryland and surrounding states.  Ultimately the data accumulated from this project will be used to create a Taxonomic Guide to the Scarabaeoidea of Maryland.  The guide will include keys to the families and genera.  We will use current collections, and historical data to map all species distributions.  Species description, and natural history data will be provided when possible.  There are many projects that are contributing to this work - please see my students projects for further interest.

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. Eugene Williams (CV)
Research in my lab centers on the acclimation, acclimatization and adaptation of fish to changes in temperature. We are interested in the biochemical, molecular and cellular attributes that allow some fish, but not others, to thrive at a wide variety of environmental temperatures. We are particularly interested in how cell membranes contribute to overall cell function during temperate acclimation. The fish we use include Icelandic Arctic charr (a trout relative), Icelandic three-spined stickleback, and Chinook salmon, rainbow trout and zebra fish cells in culture. We use the charr and stickleback to test the hypothesis that fish living for thousands of generations in an environment free of thermal variability (e.g., in cold lakes in Iceland) have lost the ability to respond to temperature change by altering their metabolism and restructuring their cell membranes. The cell culture systems allow us to pursue similar questions in a controlled laboratory environment. We also have a keen interest in understanding the relationship between fish oil and cancer. In this area we focus on the curious properties of certain membrane-associated fatty acids, the omega-3 fatty acids, which are abundant in fish oil. These fatty acids are intricately linked to cold-acclimation in fish cells but, surprisingly, they induce apoptosis, or programmed cell death, in many types of cancer cells including melanomas and leukemias. The basis of this dramatic difference in the action of the omega-3s is unclear and under examination. Most semesters we have openings for students wishing to join our effort in these areas.