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. Jessica Clark
My lab is interested in the structural and molecular changes of the peripheral nerve in hyperglycemic zebrafish. Diabetes is a growing epidemic with an estimated affliction rate of 1 in 9 Americans. Chronic hyperglycemia leads to a number of complications including vascular disease, nephropathy, retinopathy, and the most common complication, diabetic peripheral neuropathy. Axonal degradation of the peripheral nerve is responsible for the associated symptoms. However, there is a great deal of debate on why the axon is degrading. Morphological changes in the protective blood-nerve barrier, the perineurium, have been implicated in mammals and humans. Following the onset of diabetes, perineurial cells die and permeability is increased allowing toxins to infiltrate the nerve. Using a hyperglycemic induction model in zebrafish, we have interesting preliminary data; in response to hyperglycemia, perineurial cells wrap fewer motor nerves, the sensory neurons of the dorsal root ganglion tend to migrate away and lastly, motor axons and sensory axons appear defasciculated. We are currently pursuing these lines of research in my lab.
Dr. Jeremy Corfield
My previous research has shown that variations in sensory ecology between bird species leads to large differences in brain anatomy, particularly in the size of specific brain regions. I am interested in determining how these differences emerge during development. To do this we are comparing the brain development of two sensory specialists, ducks and owls, with that of an unspecialized bird, the chicken. Ducks have an amazing sense of smell and a very sensitive beak, whereas owls have an amazing visual and auditory system, leading to each having very distinctive brain anatomy. We expect that differences will come about either through timing of neural growth or by prolonging neural growth.
Dr. Elizabeth Emmert
My research focuses on Bdellovibrio bacteriovorus, a predatory bacterium that grows inside prey bacteria. As it multiplies, Bdellovibrio lyses its prey cells. Current projects in the lab investigate the use of Bdellovibrio to control bacterial pathogens that cause soft rot diseases. I am also more broadly interested in the effect of Bdellovibrio on microbial communities. Another interest of mine is soil microbiology and the effect of human activity on soil microbial activity and community composition. One current project in the lab is determining how soil microbial activity varies across campus depending on the dominant vegetation and management practices. I usually have several students working in my lab each semester. If you are interested in microbiology research, please contact me about research opportunities in my lab.
Dr. Les Erickson
Molecular signaling pathways regulate cellular processes and gene expression in response to developmental and environmental cues such as light quality, water availability, nutrient levels, pathogen attack, etc. My lab utilizes two genetic model organisms, the small plant Arabidopsis thaliana and the yeast Saccharomyces cerevisiae, to study genes, proteins, and mechanisms involved in signal transduction pathways. Our specific focus involves the ubiquitin/proteosome system. Ubiquitination, the attachment of the small protein ubiquitin to substrate proteins, plays a major regulatory role in signaling pathways. The covalent attachment of one or more ubiquitin molecules to a protein promotes its degradation via the proteasome or directly regulates its function or cellular location. Ubiquitination is a dynamic and reversible process, achieved via the balance between ubiquitination and deubiquitination, the removal of ubiquitin molecules from substrates. Ubiquitin ligases attach ubiquitin molecules to substrate proteins, while deubiquitinases (DUBs) remove ubiquitin to reverse its effects. How specific ubiquitin ligases and DUBs are regulated and how substrate targets are selected is poorly understood, although it is clear that accessory proteins are involved. We have identified a mutant yeast strain and an arabidopsis plant line that lacks one of these accessory proteins. We are currently analyzing how these mutants organisms function without this protein to understand the role it has in regulating DUB activity.
Dr. Patti Erickson
I work with the molecular genetic model organisms Arabidopsis thaliana and Caenorhabditis elegans, investigating responses, including epigenetic changes, to oxidative stress. Our C. elegansprojects involve RNA interference (RNAi) to knock down target genes and assay for altered oxidative stress responses using green fluorescent protein (GFP) promoter fusions. The Arabidopsis plant research involves characterizing the function of genes involved in ubiquitination regulation.
Dr. Mark Frana
Environmental waters in recreational and shellfish growing areas are routinely monitored for the presence of fecal bacteria. When high levels of such bacteria are detected we know that there is an increased health risk to individuals who come in contact with or who consume food products harvested from these waters. Our lab conducts studies designed to monitor the level of fecal bacteria in environmental waters and then determine the origin of those bacteria utilizing Microbial Source Tracking (MST) techniques. Possible sources of fecal organisms include failing septic systems, overflows from sewage treatment plants (human) or runoff after rain events from areas that contain livestock, pets and/or wildlife.
There are several different methods that have been successfully used in MST studies. Our lab’s current method of choice involves analyzing water samples for the presence of specific genetic markers or sequences of DNA that are uniquely associated with intestinal bacteria from a given host source (e.g. human, cattle, gull, poultry, etc.). The amount or number of copies of the specific marker DNA in a water sample can then be determined by amplifying the target DNA using real-time or quantitative Polymerase Chain Reaction (qPCR). The identification of the specific sources of fecal bacteria often found in water is aimed at guiding regulatory agencies in their attempts to control this type of contamination.
Dr. Steve Gehnrich
I currently have a research project looking at mitochondrial metabolism in honeybee flight muscle. These muscles have an extremely high rate of aerobic metabolism fueled exclusively by carbohydrate, and includes both glycolysis in the cytoplasm (resulting in the formation of pyruvate), followed by the oxidation of pyruvate via the Krebs cycle in the mitochondrial matrix. We are studying a mitochondrial pyruvate carrier (MPC), which is a protein of the inner mitochondrial membrane that transports pyruvate from the cytoplasm into the mitochondrial matrix. We hypothesize that the MPC plays a key role in helping to sustain the very high rates of Krebs cycle activity in the muscle during flight. To investigate the role of the MPC we are measuring rates of oxygen utilization by isolated mitochondria, as well as using PCR to detect the expression of the MPC gene.
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. 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.
Dr. Kimberly 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. Eric Liebgold
My students and I ask ecological and evolutionary questions relating to the interplay between animal movements and genetic structure. We are very hands-on in our lab, working in the field and handling a variety of birds, reptiles, and amphibians. We use various techniques in our research from mark-recapture field studies and playback surveys to genetic analyses with microsatellite DNA in our research. Our current research in involves several projects. We are estimating population size and genetic connectivity of endangered tiger salamander populations. We are also collaborating with Dr. Tami Ransom in the Environmental Studies Department, analyzing data from our three-year study on nest success and predation in ground-nesting warblers and studying another species of conservation concern, the spotted turtle, using turtle trapping, mark-recapture methodology, and habitat assessments to investigate the status of populations on the Eastern Shore as well as assess dispersal and other movements.
Dr. Jennifer Nyland
My laboratory has had two research focus areas, both related to the immunotoxic effects of metals exposures. In one area, we utilize epidemiological (human) studies to examine the effects of mercury on biomarkers of immune modulation and in vitro studies to probe the mechanisms of these effects. In the second area, we have utilized in vivo mouse models of disease (autoimmune myocarditis, type-2 diabetes, and obesity) to explore the impacts of mercury and arsenic exposure on mechanisms of disease progression and severity.
At Salisbury University I plan to expand on this body of research to investigate the epigenetic effects of metals exposure. We will start with in vitro effects by examining immune cell lines, such as macrophages, and then move into primary cell cultures (human peripheral blood mononuclear cells).
Dr. Dana Price
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 involves wetland biogeochemistry, specifically plant and sediment responses to changing salinity within brackish and tidal freshwater marshes. I am interested in the consequences of sea level rise for tidal freshwater marsh plant communities, and I am currently investigating the changing plant community within a marsh subjected to unusual salinity intrusion over several years.
I also advise the student volunteers for the Wicomico Creekwatchers, a monitoring program that collects and analyses water samples along the extent of the Wicomico River from March to November to assess changes in nutrient and phytoplankton levels and water clarity. Each year, one undergraduate student coordinates the analytical team and is responsible for all lab set-up and maintenance, data entry and analysis, and an independent research project related to the monitoring work.
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
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.