Life Sciences Commons^™

Demographic Assessment Of The Blue Crab (Callinectes Sapidus) In Chesapeake Bay Using Extractable Lipofuscins As Age Markers, Se-Jong Ju, David H. Secor, H. Rodger Harvey

OES Faculty Publications

The blue crab (Callinectes sapidus) plays an important economic and ecological role in estuaries and coastal habitats from the Gulf of Mexico to the east coast of North America, but demographic assessments are limited by length-based methods. We applied an alternative aging method using biochemical measures of metabolic byproducts (lipofuscins) sequestered in the neural tissue of eyestalks to examine population age structure. From Chesapeake Bay, subsamples of animals collected from the 1998-99 (n-769) and 1999-2000 (n=367) winter dredge surveys were collected and lipofuscin was measured. Modal analysis of the lipofuscin index provided separation into three modes, whereas carapace-width …

Extracellular Enzyme Activity And Uptake Of Carbon And Nitrogen Along An Estuarine Salinity And Nutrient Gradient, Margaret R. Mulholland, Cindy Lee, Patricia M. Gilbert

OES Faculty Publications

Amino acid oxidation (AAO) and peptide hydrolysis (PH) are processes affecting the recycling of organic material and nutrients. We compared extracellular AAO and PH rates to C and N uptake rates along estuarine gradients of salinity, nutrients and productivity in the Pocomoke River, a subestuary of the Chesapeake Bay. This estuary is seasonally depleted in inorganic N, and rich in dissolved organic material (DOM) throughout the year. AAO, PH, and N uptake rates measured in 1999 and 2000 were not limited to particular size fractions measured, or to auto- or heterotrophic groups of organisms. At a station near the turbidity …

The Role Of Physical, Chemical, And Microbial Heterogeneity On The Field-Scale Transport And Attachment Of Bacteria, Brian J. Mailloux, Mark E. Fuller, Tullis C. Onstott, James Hall, Hailiang Dong, Mary F. Deflaun, Sheryl H. Streger, Randi K. Rothmel, Maria Green, Donald J. P. Swift, Jon Radke

OES Faculty Publications

A field-scale bacterial transport experiment was conducted at the Narrow Channel Focus Area of the South Oyster field site located in Oyster, Virginia. The goal of the field experiment was to determine the relative influence of subsurface heterogeneity and microbial population parameters on flow direction, velocity, and attachment of bacteria at the field scale. The field results were compared with results from laboratory-scale column experiments to develop a method for predicting field-scale bacterial transport. The field site is a shallow, sandy, unconfined, aerobic aquifer that has been characterized by geophysical, sedimentological, and hydrogeological methods. Comamonas sp. strain DA001 and a …

Experimental Investigation Of Elemental Incorporation In The Otoliths Of Larval And Juvenile Fish: Implications For Use As Environmental Recorders, Gretchen Bath Martin

Biological Sciences Theses & Dissertations

Innovative techniques for discerning fish stocks, identifying nursery habitats, locating spawning sites, tracing larval transport pathways, and quantifying the degree of population connectivity are required to meet the goals of sustainable management of marine capture fisheries. One of the most promising techniques is the use of elemental signatures in fish otoliths (ear stones), which record valuable life history data and serve as the link between fish and their environment. To validate the assumption that otolith elemental composition is a function of water elemental concentrations, and to address the possible effects of external variables such as temperature and salinity, the composition …

Increase In Biomass And Soldier Production For Coptotermes Formosanus (Shiraki) Workers Maintained In The Laboratory For Up To Nine Months, Deborah Waller

Biological Sciences Faculty Publications

The factors that influence rates of soldier production in subterranean termites are poorly understood. In the present study, foraging groups of Coptotermes formosanus Shiraki were collected from baldcypress trees in Lake Charles, Lousiana, in November 1985, and February, April/May and August 1986. Termites were maintained in the laboratory for nine months, seven months, four/five months and zero months, respectively, and then examined for survivorship, termite biomass and soldier production after incubation for an additional five weeks at 30° C. Within collection periods, there was no association between survivorship and soldier production or between mean dry biomass and soldier production. However, …

Multiple Transporters Associated With Malaria Parasite Responses To Chloroquine And Quinine, Jianbing Mu, Michael T. Ferdig, Xiaorong Feng, Deirdre A. Joy, Junhui Duan, Tetsuya Furuya, G. Subramanian, L. Aravind, Roland A. Cooper, John C. Wootton, Momia Xiong, Xin-Zhuan Su

Biological Sciences Faculty Publications

Mutations and/or overexpression of various transporters are known to confer drug resistance in a variety of organisms. In the malaria parasite Plasmodium falciparum, a homologue of P-glycoprotein, PfMDR1, has been implicated in responses to chloroquine (CO), quinine (ON) and other drugs, and a putative transporter, PfCRT, was recently demonstrated to be the key molecule in CO resistance. However, other unknown molecules are probably involved, as different parasite clones carrying the same pfcrt and pfmdr1 alleles show a wide range of quantitative responses to CO and ON. Such molecules may contribute to increasing incidences of ON treatment failure, the molecular basis …

Recognizing Toxic Species In Aquatic Habitats: A Potential Concern In Lake Management, Mikolaj Kokocinski, Harold G. Marshall

Biological Sciences Faculty Publications

The importance of distinguishing toxic and non-toxic algal species is becoming a more common problem for management decisions associated with various freshwater and estuarine habitats. An example is given where two dinoflagellates, originally unidentified as closely resembling the toxin producing Pfiesteria spp., have been compared to these species. In order to clarify any relationship to Pfiesteria spp., scanning electron microscopy was used to determine the plate tabulation patterns of these dinoflagellates and make comparisons to the tabulation present in Pfiesteria spp. The results indicated significant differences in the plate tabulations of these taxa to distinguish them from Pfiesteria …

Algal Composition And Abundance In The Neuston Surface Micro Layer From A Lake And Pond In Virginia (U.S.A.), Lubomira Burchardt, Harold G. Marshall

Biological Sciences Faculty Publications

A comparative study was conducted that characterized the algae within the neuston, ca 2 mm below the surface, and the algae in the water column from two freshwater habitats. There were significant differences in total algal abundance and the abundance of diatoms, cyanoprokaryotes, and chlorophytes between the neuston and water column algae of these two regions during each season and at both sites. The pond neuston was dominated by chlorophytes, with total algal abundance ranging seasonally from 0.6 to 59.6 x 10^-3 cells ml^-1 compared to water column algal concentrations of 4.1 to 40.4 x 10-3 cells ml-1. …

Embryo And Gamete Development Upon Exposure To Cca Components: Cro3, Cuo, And As2o5, Nerbana Talaat-Elsebaei Mahmoud

Theses and Dissertations in Biomedical Sciences

Production of functional gametes and healthy embryos is essential for proliferation of all vertebrates, especially humans. Many compounds have toxic effects on developing gametes and embryos among which are chromium trioxide (CrO₃), cupric oxide (CuO) and arsenic pentaoxide (As₂O₅) as a mixture (CCA) or individually. Controversy surrounding the safety of CCA-treated wood centers primarily on the toxicity of its components and the potential for these metals to be released from the wood.

The aim of this research is to test the hypothesis that CCA components have deleterious effects on embryo development, oocyte maturation and …

Electric Field Enhanced Plasmid Delivery To Liver Hepatocellular Carcinomas, Richard Gilbert, Mark J. Jaroszeski, Loree Heller, Richard Heller

Bioelectrics Publications

Electric field enhanced molecular delivery for cancer research and treatment is a new technology that has demonstrated its effectiveness in clinical trials using bleomycin or cisplatin (Heller, R., Gilbert, R., Jaroszeski, M. J. Clinical applications of electrochemotherapy, Advanced Drug Delivery Reviews 35,119-129, 1999), as chemotherapeutic agents. The technology is being investigated in research applications for applicability as a method to enhance gene expression in a target tumor. Success is predicated on an appropriate effective electric field mediated delivery protocol that triggers significant appropriate gene expression duration and levels. An electric field mediated delivery protocol includes a set of conditions …

Identifying Sources Of Fecal Pollution In The Roanoke River, Roanoke County, Virginia, J. Brooks Crozier, Brian Clark, Holly Weber

Virginia Journal of Science

Antibiotic Resistance Patterns (ARPs) of Enterococcus spp. were used as a phenotypic fingerprint to compare and categorize unknown-source isolates in an impaired segment of the Roanoke River, Roanoke County, Virginia. Antibiotic resistance analysis (ARA) of enterococci has been effectively used to differentiate among sources of fecal contamination in many geographic regions in the United States. Enterococcus spp. were used as a fecal indicator in a library consisting of 1,562 known-source isolates. Two-way analysis indicated that approximately 95% of the unknown-source isolates collected were of animal origin. A 3-way analysis indicated that 61% of the unknowns were of livestock origin while …

Longevity Record For A Wild Allegheny Woodrat (Neotama Magister) In West Virginia, Michael T. Mengak, Steven B. Castleberry, W. Mark Ford, Nikki L. Castleberry, Jane L. Rodrigue

Virginia Journal of Science

The Allegheny woodrat (Neotoma magister) is found throughout much of the central and southern Appalachians and adjacent portions of the Interior Highlands. Allegheny woodrats have declined in the northern portions of their range and are state-listed as threatened, endangered or sensitive species of concern in every state where they occur. Until recently, biologists have had to rely on biological data collected from the closely related eastern woodrat (N. floridana) because of limited research on the Allegheny woodrat. We have been studying the ecology and natural history of woodrats in Virginia and West Virginia since 1990. On …

Benthic Biological Monitoring Program Of The Elizabeth River Watershed (2001) With A Study Of Paradise Creek, Daniel M. Dauer

Elizabeth River Reports

Executive Summary

A study of the macrobenthic communities of the Elizabeth River watershed was initiated in summer 1999. This report presents the data from the third year of sampling in 2001. The three objectives of the Benthic Biological Monitoring Program of the Elizabeth River watershed are: (1) To characterize the health of the tidal waters of the Elizabeth River watershed as indicated by the structure of the benthic communities. ( 2) To conduct trend analyses on long-term data at 14 fixed-point stations to relate temporal trends in the benthic communities to changes in water and/or sediment quality. Trend analyses will …

Histological Evaluation Of Cryopreserved Ovaries In Autologous Abdominal Transplant To NaïVe, Outbred, Cd1, Mice, Wentia Elissa Ford

Biological Sciences Theses & Dissertations

This study showed that fresh and frozen-thawed mouse ovaries would maintain viable primordial or primary follicles post-autologous transplantation. Furthermore, with appropriate hormonal stimulation, these early-stage follicles were shown to develop into Graafian follicles containing a metaphase II antral ovum. Partially sliced ovaries were transplanted into the abdominal cavity of naive, outbred, CD1, white mice. Hormonal stimulation with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) one week after the autologous transplantation stimulated variable degrees of follicle and ovum maturation within the ovarian tissue. There were no major morphological differences observed between the four groups, three treatment and one …

Recruitment Variability Of Atlantic Croaker, Micropogonia Undulatus, With Observations On Environmental Factors, Sumalee Hoskin

Biological Sciences Theses & Dissertations

I examined entrance patterns of Atlantic croaker, Micropogonias undulatus by comparing the abundance, length, age and growth rates, of larvae as they entered Oregon and Ocracoke Inlets, NC. These biological factors were then compared against environmental factors to assess the influence the physical environment has on recruitment variability. Entrance abundance into Oregon Inlet was an order of magnitude higher than abundance into Ocracoke Inlet. However, the difference was influenced by three peak events in Oregon Inlet and non-parametric tests found no difference in median abundance between the two inlets. Mean standard length was smaller at Oregon Inlet than Ocracoke Inlet …

The Effect Of A Predator Gradient On Female Oviposition Site Selection And Larval Performance, Josef F. Rieger

Biological Sciences Theses & Dissertations

Patterns of larval amphibian distribution and abundance have historically been ascribed to direct predation. However, adult oviposition site selection is an alternative mechanism that can produce identical patterns and significantly influence community assembly. Although such behavioral habitat selection has been documented in several amphibian species whose larvae lack particular anti-predator defenses, the sensitivity of adult amphibians in detecting predator cues and avoiding these habitats has not yet been determined. If larval survivorship is greatly reduced in sites containing predatory fish, selection to detect and avoid habitats with low fish densities should be strong. I conducted three experiments which, (1) evaluated …

Electrically Mediated Delivery Of Vector Plasmid Dna Elicits An Antitumor Effect, L. Heller, D. Coppola

Bioelectrics Publications

In vivo electroporation is an efficient means of increasing plasmid DNA delivery to normal tissues, such as skin and muscle, as well as directly to tumors. In the experiments described here, plasmid DNA was delivered by in vivo electroporation to B16 mouse melanomas using two very different pulsing protocols. Reporter expression increased 21- or 42-fold, respectively with electroporation over injection alone. The growth of experimental melanomas with an approximate diameter of 4 mm on the day of treatment was monitored after electroporation delivery of reporter plasmid DNA. Remarkably, short-term complete regressions using one of these pulsing protocols occurred in up …

Fine Root Vitality And Its Application In A Minirhizotron Study Of A Co2 Enrichment In A Florida Scrub Oak Ecosystem, Brandon Todd Herbert

Biological Sciences Theses & Dissertations

Minirhizotron images are assigned color codes to approximate the age of individual roots in situ. Triphenyl-tetrazolium chloride (TTC) has been used to measure the vitality of plant tissue by detecting dehydrogenase activity. TTC was used to assess the vitality of root tissue by color in a scrub oak ecosystem at Kennedy Space Center in central Florida. Roots were excavated, sorted into four color classes and stained with TTC. The product of the reduction of TTC by dehydrogenase enzyme, formazan, was extracted and its absorbance recorded using a spectrophotometer. A significant difference (p2 enrichment being conducted on a scrub oak …

Long Term Residual Effects Of A Nutrient Addition On A Barrier Island Dune Ecosystem, Susan M. Heyel

Biological Sciences Theses & Dissertations

In 1991, 150 m² were fertilized with nitrogen on three dunes on Hog Island, part of the Virginia Coast Reserve Long Term Ecological Research site, to examine plant community response to nitrogen addition. In 2000, the fertilized plots continued to exhibit a positive growth response. This study sampled the aboveground biomass, belowground biomass, and nutrient content of the experimental plots to examine the long- term patterns of nitrogen retention in a nitrogen limited system. Aboveground and belowground biomass was significantly greater in the fertilized plots than in the control plots. Aboveground biomass exhibited was significantly greater in control and …

The Effects Of A 10-Week Exercise Program On Physiological Variables And Quality Of Life In Type 2 Diabetes, David Robb Holton

Human Movement Studies & Special Education Theses & Dissertations

The purpose of this study was to determine the interaction between psychological and physiological parameters before and after a 10-week, aerobic training study of sedentary diabetic individuals and sedentary controls. Tests measuring physiological parameters (interstitial NO, blood flow, lactate threshold, VO₂ peak and glycosylated hemoglobin) and a quality of life survey were completed before and after training. Nine previously sedentary diabetic (DE, diabetic exerciser) and 10 control sedentary subjects (CE, control exerciser) engaged in 10 weeks of supervised aerobic exercise. A non-training diabetic group (DS, diabetic sedentary, n=12) and a non-training control group (CS, control sedentary, n=I0) were also …

Involvement Of Platelet-Derived Growth Factor, Pdgf Receptor Signaling, Focal Adhesion Kinase And Src In Pressure-Induced Vascular Smooth Muscle Hypertrophy, Darian Clark Rice

Theses and Dissertations in Biomedical Sciences

Elevated blood pressure is associated with varying degrees of arterial remodeling. The mechanisms by which extracellular mechanical stress is converted into intracellular alterations in signal transduction and gene expression have yet to be fully elucidated. Our goal was to investigate the early events in the vascular smooth muscle response to acute hypertension and to identify mediators involved in long-term hypertensive remodeling.

In the acute phase of hypertension we targeted cell surface integrin and growth factor receptors thought to be mechanically sensitive. The signaling molecules FAK, Src and ERK-MAPK are known to be triggered by integrin engagement and growth factor receptor …

Effect Of Electrically Mediated Intratumor And Intramuscular Delivery Of A Plasmid Encoding Ifn Α On Visible B16 Mouse Melanomas, Loree C. Heller, Stephanie F. Ingram, M. Lee Lucas, Richard A. Gilbert, Richard Heller

Bioelectrics Publications

Interferon α may be used as a single agent therapy for metastatic malignant melanoma or as an adjuvant to chemotherapy. Delivery of interferon α by gene therapy offers an alternative to recombinant protein therapy. Electrically mediated delivery enhances plasmid expression in a number of tissues, for instance skin, liver, muscle and tumors including melanomas. Here we compare the effect of delivery of a plasmid encoding mouse interferon α on growth of visible B16 mouse melanomas following electrically mediated delivery to muscle or directly to the tumor. Intratumoral delivery of interferon α plasmid not only slows melanoma growth, but induces complete, …

Reproduction Of Black Drum, Pogonias Cromis, From The Chesapeake Bay Region, Brian K. Wells, Cynthia M. Jones

Virginia Journal of Science

Ovaries of black drum, Pogonias cromis, collected from the Chesapeake Bay region in 1992, were used to describe reproductive strategy and fecundity. Histological examination showed that black drum spawn in the Chesapeake Bay region from April through early June. Distributions of oocyte diameter showed distinct oocyte-developmental groups indicating that Chesapeake Bay black drum are group-synchronous batch spawners. Female black drum are extremely fecund ranging from 414,000 to 3,736,000 hydrated oocytes (mean = 1,389,000) per batch with a spawning periodicity of 3.8 days. Estimates of spawning strategy, spawning periodicity, and batch fecundity for black drum from the Chesapeake Bay region …

Autotrophic Picoplankton: Their Presence And Significance In Marine And Freshwater Ecosystems, Harold G. Marshall

Virginia Journal of Science

Invited lecture: Autotrophic Picoplankton Workshop, 52nd Congress of the Polish Botanical Society, Adam Mickiewicz University, Poznan, Poland, September 2001 .

Reproductive Differences Among Delmarva Grass Shrimp (Palaemonetes Pugio And P. Vulgaris) Populations, Holly H. Ganz, Robert E. Knowlton

Virginia Journal of Science

Populations of female grass shrimps (Palaemonetes pugio and P. vulgaris) were sampled from five coastal embayments in Delaware, Maryland, and Virginia (Delmarva) and compared with respect to reproductive and life history attributes. We observed interspecific differences in timing of reproduction, carapace length, ratio of carapace length to total body length, body weight, clutch weight, clutch size, and egg volume. Onset of reproduction in P. vulgaris lagged behind P. pugio. Although there was no difference in the relationship between clutch size and carapace length for the two species, carapace length/total body length in P. pugio was greater than …

Development Of Diagnostic Approaches To Determine Sources Of Anthropogenic Stress Affecting Benthic Community Conditions In The Chesapeake Bay, Daniel M. Dauer, Michael F. Lane, Roberto J. Llansó

Benthic Applications

Benthic macrofauna are an important component of estuarine ecosystems. These organisms are a food source for higher trophic levels including fishes and crabs (Virnstein 1977, 1979; Holland et al. 1980; Dauer et al. 1982) and birds (Botton 1984; Quammen 1984). Benthic macrofauna affect both the physical and chemical properties of the sediment and the overlying water column (e.g., Rhoads and Young 1970; Rhoads 1973; Aller 1978, 1980), influence nutrient cycling (Rowe et al 1975; Zeiteschel 1980; Flint and Kamykowski 1984), and are capable of directly controlling phytoplankton biomass in the water column (Cleorn 1982; Officer et al 1982; Cohen et …

A Study Of Radiofrequency Effects On Gene Expression, Elizabeth A. Coln

Electrical & Computer Engineering Theses & Dissertations

Numerous studies have been completed over the past several years to look at the non-thermal effects of low-level radiofrequency exposure on biological systems. These studies were done to determine if exposure to radiofrequency fields are safe, or if they may lead to health problems or changes to any of the biological processes continually occurring within the human body. Responses measured include stress responses (I), gene expression (2), cell proliferation (3), cell morphology (4), and changes in DNA (5).

Dispersion is the most common model for explaining the electric behavior of biomaterials. It refers to the corresponding frequency domain concept of …

Vertical Distributions Of Zooplankton At The Mouth Of Chesapeake Bay And Calibration Of Backscatter From An Acoustic Doppler Current Profiler, Arthur Keith Jenkins

Biological Sciences Theses & Dissertations

This study investigated the physical factors influencing the vertical distribution of zooplankton at the mouth of the Chesapeake Bay and attempted to derive biological data from acoustic Doppler current profiler (ADCP) backscatter. A single site was occupied in the North Channel at the mouth of Chesapeake Bay (37° 04' N, 75° 58' W) from 17.0–19.7 November 1999. Temperature, salinity, fluorescence, light transmission, current velocity and backscatter were measured throughout the sampling period. Plankton samples were collected every hour from 3.5, 7.5, and 11.5 m.

We found little association between ADCP backscatter and plankton concentrations, but stronger correlations between backscatter and …

Anting Behavior In Birds: Ant Selection And Effect Of Ant Chemistry On Feather Ectoparasites, Hannah Carrington Revis

Biological Sciences Theses & Dissertations

Active anting behavior occurs when songbirds apply ants to their feathers. During anting displays, a bird draws its wings forward in front of the head and swings its tail around to the far right or left. Both wing and tail feathers are then rubbed with ants held in the bird's beak. The potential associations among ants, feather ectoparasites and birds make anting behavior an important community-level interaction. Although this behavior is cosmopolitan in distribution and occurs in a wide variety of passerine birds, it remains poorly understood. This dissertation tested hypotheses about anting behavior through controlled experiments with captive songbirds …

Summer Vertical Phytoplankton Distribution In The Lower Chesapeake Bay, Mollie Jill Weinstein

Biological Sciences Theses & Dissertations

Autotrophic picoplankton and phytoplankton composite samples were collected from the surface, pycnocline, and bottom water layers at three stations in the lower Chesapeake Bay between June and September 1993. Using light microscopy a total of 170 phytoplankton taxa were identified. Utilizing epifluorescent microscopy, the picoplankton taxa were distinguished by size, representing species with cells less than 2 microns. Diatoms were the dominant taxa during this period, with lesser representation by the other phytoplankton components. Within the picoplankton category, cyanobacteria were dominant. Statistical analyses of the data indicated the vertical composition and abundance of the phytoplankton was not significantly different over …