Life Sciences Commons^™

High Performance Liquid Chromatographic Separation Of Different Types Of Collagen, Yongjoo Chung

Chemistry & Biochemistry Theses & Dissertations

The objective of this research was to develop a method for the separation of different types of collagen using a large pore size (100 nm) reversed-phase C-8 column. Three different types of collagen (type I, III, and V) were sufficiently separated on the column using a mobile phase containing water-acetonitrile-trifluoroacetic acid. Collagens found in each HPLC peak were identified using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to assay the column effluents.

Trifluoroacetic acid (TFA) was used as an ion pair reagent. This compound improved the chromatographic profile for these proteins on a reversed-phase column. It was observed that with …

The Role Of Gaba In Reproductive Neuroendocrine Systems, Robert Carter Mcree

Theses and Dissertations in Biomedical Sciences

Local gamma-amino butyric acid (GABA) neurons in the hypothalamus can modulate the luteinizing hormone releasing hormone (LHRH) pulse generating system.

Two animal models (intact and ovariectomized rats) were used to determine the nature of modulation of LHRH release by GABA. The experiment determined the release of LHRH, serotonin (5-HT), and 5-hydroxyindole acetic acid (5-HIAA) during two hormonal states with each model. In the intact rat the proestrus and estrus states were examined, and in the ovariectomized rat in-vitro release was determined with (OVX₂) and without (OVX) estradiol treatment.

In-vivo experiments studied the effect of stimulation of GABA receptors …

Community Structure Of The Macrobenthos In Back Bay, Virginia, Michael F. Lane

Biological Sciences Theses & Dissertations

A study of the subtidal macrobenthos in Back Bay, Virginia was conducted to examine community structure in relation to sedimentary and water quality characteristics. Samples were collected in August and November of 1987 and February and May of 1988 at ten stations.

Three site groups and three temporal groups were identified by cluster analyses of species abundance. Species composition between site groups was relatively homogeneous and eight species accounted for most of the variation between site groups. A comparison of plots of the biological and physical data in discriminant space suggested that variations in the biological data between site groups …

Population Dynamics Of Feral House Mice And Meadow Voles On A Dredge Disposal Site, Georgia E. Kratimenos

Biological Sciences Theses & Dissertations

The population dynamics of two species was studied for one year on Craney Island in Portsmouth, Virginia. This dredge disposal site provided good habitat for the house mouse, Mus musculus, whose opportunistic behaviors can withstand the sudden changes in a dynamic environment. Although the site was not optimal habitat, a population of Microtus pennsylvanicus, the meadow vole, was sustained there. Of the seven species of small mammals captured, 65% were house mice and 28% were meadow voles. Meadow voles were more successful at establishing short periods of residency than were house mice; on average, each meadow vole was …

Osteoinductivity Of Demineralized Bone: A Quantitative In Vitro Assessment, Yihong Zheng

Biological Sciences Theses & Dissertations

Acid demineralized bone (DMB) implanted in extraosseous sites induces bone formation. In vivo studies have shown that DMB stimulates the differentiation of mesenchymal cells into osteogenic cells. In this study an in vitro system was developed to demonstrate the osteoinductivity of DMB quantitatively. This in vitro working system was used to assess the osteoinductivity of variously processed DMB products as a means to evaluate their processing protocols. A human dermal fibroblastic (HDF) cell line was initiated from tissue explants as a working model, along with a human periosteal (HPO) cell line as a control. Ground DMB processed by LifeNet Transplant …

Computer Simulation Techniques To Assess Bias And Precision In The Roving Creel Survey Estimator, David L. Wade

Biological Sciences Theses & Dissertations

Fisheries scientists use roving creel survey methods to estimate total catch and total effort of recreational fisheries. Bias in the roving creel estimators had been known to the scientific community, but it had not been quantified. I developed a roving-creel-survey computer simulation model to investigate the bias and precision of roving creel estimators, and estimated parameters for the model based on field observations from the blue crab (Callinectes sapidus) fishery of the Chesapeake Bay. The computer model was used to identify bias in roving-creel effort and catch estimators and to demonstrate survey methods that will reduce this bias. …

Purification And Characterization Of The Prostate Cancer-Associated Antigen: 7e11-C5, Qi Feng

Theses and Dissertations in Biomedical Sciences

A murine monoclonal antibody (MAb), 7E11-C5, recognizes a prostate organ-specific antigen. Under reducing conditions, the 7E11-C5 antigen exhibited major 100-Kd and minor 70-Kd bands, suggesting that the antigen comprises two peptide chains. The antigen was detected in pooled normal human seminal plasma, xenograft tissue extract of a prostate adenocarcinoma cell line, LNCaP, and tissue extracts of benign prostatic hyperplasia (BPH) and prostate carcinomas, but was not identified in any of the non-prostate tissue extracts tested. Antibodies of the three major prostate-associated antigens (prostatic acid phosphatase (PAP), prostate specific antigen (PSA) and prostate secretory protein (PSP)) were unable to block the …

Nitrogen Dynamics Of The Acacia Senegal Agroforestry System In The Sudan, Zakaria Abdalla Mohammed Saad

Biological Sciences Theses & Dissertations

The savanna is characterized by low rainfall, poor soil and vegetation types dominated by the Genus Acacia. Agroforestry systems evolved, the most notable of which is Acacia senegal agroforestry system (ASAS). It yields gum acacia, fuel and fodder and improved soil N, P, and pH and stability against erosion.

This study investigated the climatic, edaphic and biotic interactions of the ASAS that govern the nutrient dynamics, mainly N, and biomass. The effects of limited resources of soil, space and photoperiod on biomass, nodulation and rate of N fixation were investigated. Genetic differences among populations were studied. Progenies of selected …

Age Growth And Reproduction Of Black Drum, Pogonias Cromis, In Virginia, Stephen J. Bobko

Biological Sciences Theses & Dissertations

The black drum, Pogonias cromis, is of great economic importance to the communities of the lower Eastern Shore of Virginia. Fish are sought both commercially and recreationally during their yearly spring spawning run. Although the number of fish caught each year does not rival other exploited species, it is a directed fishery that partially supports many local fishermen, seafood distributors, marinas, motel owners, and restauranteurs.

Black drum were collected during the fall of 1989 and the spring of 1990 to investigate the population dynamics of fish found in Virginia's Chesapeake Bay and surrounding coastal waters. A total of 235 fish …

Vitellogenesis In Hyalomma Dromedarii (Acari: Ixodidae): A Model For Analysis Of Endocrine Regulation In Ixodid Ticks, Martin E. Schriefer

Theses and Dissertations in Biomedical Sciences

The egg yolk proteins, vitellins, and their hemolymph precursors, vitellogenins, were characterized in the ixodid tick Hyalomma dromedarii. Three vitellins were identified. The high molecular weight vitellins, VN A and VN B, were composed of seven homologous molecular weight subunit polypeptides, VN 1-7. VN A appears to be a dimeric form of VN B. VN C was composed of single polypeptide. Low levels of vitellogenin, were identified in western immunoblots utilizing antibody raised against purified vitellin. Adult protein and polypeptide profiles, including vitellin and vitellogenin, were characterized as a function of sex, tissue and reproductive development. Quantitative assessment of the …

The Role Of Queuine Deficient Trna In Translational Control, Kathryn Lenore Hart

Theses and Dissertations in Biomedical Sciences

The purpose of this research was to study the effect of the level of tRNA modification with respect to queuine on translational efficiency. Transfer RNA from neoplastic cells is generally deficient with regard to certain hypermodified nucleosides found in normal cells. The hypothesis that was examined is whether or not the altered efficiency of translation can be correlated to the presence of queuine hypomodified tRNA. The loss of queuine in the anticodon may change the interaction of the tRNA's anticodon with its codon. Therefore, the translational complex may stall looking for a rare tRNA, or the stability of the complex …

A Biochemical Study Of Gossypol And Lactate Dehydrogenase X Binary Interactions, Patricia Brown Ravenell

Theses and Dissertations in Biomedical Sciences

The goal of this project was to study the mechanism of action of gossypol through its (a) binary interaction with native and trypsin digested lactate dehydrogenase-X (LD-X), a sperm-specific isozyme, and (b) its binding in vitro in primary cultures of spermatogenic cells. Mouse LD-X was cleaved with trypsin before and after treatment with gossypol. This was followed by high performance chromatography (HPLC) separation of the LD-X tryptic peptide fragments to observed alterations in separation patterns as indicators of intramolecular disturbance in the enzyme molecule. Definite alterations in peptide fragment peaks were observed in the presence of gossypol and suggest conformational …

Development And Characterization Of Monoclonal Antisperm Antibodies: Potential For Contraception, Dilrowshan H. Haque

Theses and Dissertations in Biomedical Sciences

There is an expressed need to develop a greater variety of safe contraceptive methods which would find acceptance worldwide, particularly in developing countries. Immunization against spermatozoa might be such a method as judged by the accumulated evidence from studies on human females and in a number of female animal species.

Two extraction techniques were used for sperm membrane antigen isolation. The first technique involved NP-40 detergent for antigen extraction from human motile sperm and the second technique employed homogenized human testis for antigen extraction. Using these immunogens, sperm membrane-specific monoclonal antibodies (MAbs) were developed. When these antisperm MAbs were subjected …

Fertilization And Mouse Embryo Development In The Presence Of Midazolam, Maria Leavitt

Biological Sciences Theses & Dissertations

The development of mouse embryos in vitro has provided a unique opportunity for the study of cellular differentiation and the influence of various agents on differentiation. Midazolam is administered for conscious sedation in the recovery of human ova. In the Norfolk IVF Program, midazolam is found in varying concentrations in follicular fluid. Mouse embryo formation and development has been used to test midazolam's effect on fertilization and early development as a model of human in vitro fertilization and development. Midazolam' s effects were studied using varying doses of midazolam on (1) in vivo fertilization and subsequent cell division, and (2) …

The Study Of Natural Product(S) From Opsanus Tau (Linnaeus), The Oyster Toadfish, Miki Taira

Chemistry & Biochemistry Theses & Dissertations

Opsanus tau (Linnaeus), the Oyster toadfish, commonly inhabits the Chesapeake Bay. The Oyster toadfish has been categorized as a venomous and/or ichthyotoxic fish; however, chemical studies to substantiate these claims have not been forthcoming.

The oyster toadfish has dorsal and opercular spines which are believed to secrete a venom(s). Based on our findings, the oyster toadfish does not secrete venom(s) from these spines.

The oyster toadfish secretes large amounts of a mucus when it is irritated. 3-Octanone was believed to be the major ichthyotoxic component of the mucus from the oyster toadfish. Based on our investigation, 3-octanone is present only …

Assessment Of Organic And Metal Contaminants In Lower Back Bay And Upper Currituck Sound, Kate Benkert

V. Poster Abstracts

Studies were conducted at Mackay Island National Wildlife Refuge in 1988 and 1989 to provide baseline data for an assessment of organic chemicals and metal contaminants in the aquatic ecosystem. Longnose gar, gizzard shad, snapping turtles, common rangia clams and sediments were collected from sites in lower Back Bay and upper Currituck Sound for contaminant analyses.

Composite sediment samples were analyzed for the presence of metals, organochlorine pesticides and polycyclic aromatic hydrocarbons (PAHs). Organochlorine pesticides were not detected in the sediments. Various PAH compounds were detected in the sediments, although at trace concentrations which just exceeded the analytical detection limit …

Environmental Education: A Chance For The Future, Ben Mathias

V. Poster Abstracts

The U.S. Fish and Wildlife Service is committed to providing environmental education opportunities for the Nation's student body. Local, regional and national educators are invited to investigate and utilize the resources of Back Bay National Wildlife Refuge with their colleagues and students. Teacher workshops at the Refuge provide orientation to Refuge lands, outdoor classroom sites, trails, interpretive facilities and equipment, and potential field activities. Refuge staff members are available to assist with: • Preliminary planning • Group scheduling • Library research • Workshop registration • Trip logistics and • On-site group orientation. Most classroom sites, associated trails/boardwalks, and Visitor Contact …

Feeding By Reticulitermes Spp., Deborah A. Waller

Biological Sciences Faculty Publications

No abstract provided.

History And Analysis Of Food Guides In The United States, Barbara B. Carlson

Health Services Research Dissertations

This work elucidates the development of nutrient-based dietary standards in the United States from the original energy and protein-based standards proposed by Atwater in 1894 to the micronutrient-based Recommended Dietary Allowances revised by the National Research Council in 1989. This qualitative historical research chronicles the development and subsequent revisions of nutrient-based food guides and food guidance models issued in the United States between 1916 and 1991. A literature search of historical food guides, research, and review papers from the fields of nutrition science and education, dietetics, and health science provided primary sources of information for the history. A literature search …

Seasonal Phytoplankton Assemblages Associated With The Chesapeake Bay Plume, Harold G. Marshall

Biological Sciences Faculty Publications

Waters associated with the Chesapeake Bay plume were highly variable, unstable, and subject to the influence of flow patterns into and out of the Bay. Seasonal phytoplankton assemblages were identified for this region, with the phytoplankton development similar to the seasonal spring-fall growth maxima over the shelf, yet influenced by the multi-pulsed patterns often noted in the lower Bay. Major dominants included species common to both the shelf and lower Chesapeake Bay.

Cell Surface-Binding Sites For Progesterone Mediate Calcium Uptake In Human Sperm, Peter F. Blackmore, Joseph Neulan, Frank Lattanzio, Stephen J. Beebe

Bioelectrics Publications

Recent studies (e.g. Blackmore, P. F., Beebe, S. J., Danforth, D. R., and Alexander, N.) (1990) J. Biol. Chem. 265, 1376-1380) have shown that in human sperm, progesterone produces a rapid increase in intracellular free calcium ([Ca2+]i) and an induction of the acrosome reaction (e.g. Osman, R. A., Andria, M. L., Jones, A. D., and Meizel, S. (1989) Biochem. Biophys. Res. Commun. 160, 828-833). In this study, the location of progesterone receptors on the cell surface of human sperm was identified using progesterone immobilized on bovine serum albumin (BSA) (progesterone 3-(O-carboxymethyl)oxime:BSA) as well as progesterone and its 3-O-carboxymethyloxime derivative. Using …

Rx For Success At Back Bay National Wildlife Refuge: Take Two Committed Partners-Add Water, Janet Taylor, Julia Herrick, Ben Mathias

V. Poster Abstracts

As part of a major effort to improve habitats for waterfowl and other wetland-dependent wildlife, Ducks Unlimited, Inc. is contributing $187,500 in matching funds to help the U.S. Fish and Wildlife Service rehabilitate wetland impoundments at Back Bay NWR.

The three-year project will increase Refuge management capabilities on existing wetland areas, create 300 acres of new marsh habitat and increase water management flexibility throughout the impoundment system. Components of the project include:

• Raising and re-sloping 8 miles of existing dikes
• Installing 13 new water control structures
• Constructing 6,000 feet of new dikes
• Creating two storage pools totalling 53 acres and …

U.S. Fish And Wildlife Service Back Bay Initiative: Goals And Objectives, David A. Stilwell

V. Poster Abstracts

Back Bay has historically been noted for its abundant wildlife and fisheries. A testimony to this fact has been the establishment of two U.S. Fish and Wildlife Service National Wildlife Refuges (Back Bay and Mackey Island National Wildlife Refuges), three Virginia Department of Game and Inland Fisheries Waterfowl Management Areas (Pocahontas, Barbours's Hill, and Trojan Waterfowl Management Areas) and a State park (False Cape State Park). Back Bay has been a major stopover point for waterfowl in the North Atlantic flyway, it had prodigious submerged aquatic vegetation (SAV) beds and an outstanding fisheries. Since the l 920's these resources have …

Refuge Land Acquisition: Helping Preserve Back Bay's Wildlife Heritage, Julia Herrick, Ben Mathias, Janet Taylor

V. Poster Abstracts

The once-renowned waterfowl populations and bass fishery of Back Bay, Virginia have declined dramatically in recent years. Lands surrounding Back Bay are increasingly threatened by on-going and potential land development. These lands serve as an important filter for pollutant and sediment-laden runoff from adjacent areas. The boundary of the Back Bay National Wildlife Refuge was expanded in 1989 to include an additional 6,340 acres of brackish marsh, forested swamp, and "critical edge" upland habitat, important to a variety of wildlife species and for its natural filtering effect. Within the U.S. Fish and Wildlife Service's policy of working with willing sellers, …

Activator-Inhibitor Control Of Tissue Growth, John A. Adam

Mathematics & Statistics Faculty Publications

This note develops a simple model for the competition between activator and inhibitor control mechanisms in one-dimensional tissue growth. The pedagogic usefulness of such a model is that it is easily accessible to undergraduate applied mathematicians and is suggestive of behavior known to occur in more realistic biological systems (e.g., some types of cancer). The limitations of the model are obvious and can provide a basis for discussion of the applicability of complementary levels of description in mathematical modeling.

Sediment Denitrification Potential In The Elizabeth River, Virginia, Surena Fazeli-Matin, Andrew S. Gordon, Harold G. Marshall

Biological Sciences Faculty Publications

Sediment denitrification potential from two sites in the Elizabeth River estuary was studied over a nine-month period using the acetylene blockage method. Rates of microbial processes in this environment are of interest because of the high concentration of toxics present in some parts of the system. Highest rates were found in the highly polluted Southern Branch of the Elizabeth River with nitrate amended sediment ranging from 2-262 nmol N₂0/h per 20ml of sediment and exhibiting maximal rates during spring and fall. Rates in the Main Stem of the Elizabeth River were lower, with less than 1-85 nmol N …

Observations Of The Phytoplankton Standing Crop At The Shelf Margin Of The Mid Atlantic Bight, Bruce B. Wagoner, Harold G. Marshall

Biological Sciences Faculty Publications

A comparison of the total percentage cell abundance and cell biovolume relationships of major phytoplankton categories was made between two station sets across the shelf margin. Diatom values for abundance and biovolume were greater at oceanic stations compared to the outer shelf stations, with dinoflagellates having the reverse pattern. The composite contributions to biovolume and abundance in the standing crop from other phytoplankton categories were greater over the outer shelf than beyond the shelf margin. The major source of biovolume (biomass) from the outer shelf and these oceanic stations came from the diatoms and dinoflagellates, with an average mean of …

Development And Evaluation Of Tracer Particles For Use In Microzooplankton Herbivory Studies, Mary Putt

OES Faculty Publications

Two methods of preparing algae for use as tracer particles in single species measurements of microzooplankton herbivory were evaluated. Algae were either heat-killed and labelled with 5-(4,6-dichlorotriazin-2-yl amino fluorescein) (DTAF) (Rublee & Gallegos 1989; Mar, Ecol. Prog. Ser. 51: 221-227) or stained with hydroethidine (HYD). Both DTAF and HYD-stained algae were readily visible within the digestive vacuoles of most microzooplankton collected in estuarine and coastal waters of Massachusetts (USA) and preserved with Lugol's iodine. However, DTAF was ineffective at staining several chromophytic algae and the heat-kill process reduced cell volume by ≥ 50% in several of the algae which were …