Life Sciences Commons^™

Population Variation In The Mitochondrial-Dna Of Two Marine Organisms: The Hard Shell Clam Mercenaria Spp. And The Killifish, Fundulus Heteroclitus, Bonnie Lynn Brown

OES Theses and Dissertations

The two major topics are covered in this dissertation: the integration of molecular genetic tools with applied aquacultural research and short-term evolutionary dynamics. The first study investigated the extent of geographic differentiation of native clam stocks along the U.S. east and Gulf coasts. Clam mitochondrial DNA (mtDNA) demonstrated size polymorphism (16.5-19.0 kb) and restriction site heteroplasmy. Size heteroplasmic individuals occurred at a frequencies of 0-89% in clam populations. Restriction site heteroplasmy occurred in 12% of the 317 individuals assayed. Results of the study indicated that although harbouring a wealth of genetic variation, clams from northern regions were similar and lacked …

Platelet Function And Energy Metabolism During Storage In A Well-Defined Experimental Medium, Thais Edwina Ahrendt Keegan

Theses and Dissertations in Biomedical Sciences

The most significant problem in maintaining platelet viability during storage is the decrease in pH resulting from accumulation of lactic acid formed by platelet anaerobic glycolysis. This study investigates nutrient alternatives to glucose for maintenance of morphology and functional integrity during platelet storage in a well-defined synthetic medium and correlates this data with purine nucleotide levels determined by high-performance liquid chromatography (HPLC) and other in vitro measures of platelet quality. Platelets prepared from pooled ABO- and Rh- identical platelet-rich plasma were stored as concentrates in the synthetic medium without added nutrients (control) and with added substrates.

The HPLC procedure developed …

Evidence For The Role Of Ecdysteroids In The Genital Sex Pheromone Of Two Species Of Hard Ticks, Dermacentor Variabilis (Say) And Dermacentor Andersoni Stiles, Demar Taylor

Biological Sciences Theses & Dissertations

Neutering of part-fed females virtually eliminated copulatory behavior in Dermacentor variabilis and D. andersoni males. Extracts from the anterior reproductive tracts (ART) of part-fed (7 days) females restored the male copulatory behavior in conspecific neutered females, suggesting the presence of a genital sex pheromone (GSP). Similar extracts from unfed females did not restore the behavior, suggesting that the pheromone was produced during feeding. Perception of the GSP by sensillae on the male cheliceral digits was confirmed by electrophysiological techniques.

Ecdysteroids, specifically ecdysone and 20-OH-ecdysone were shown to be present in the anterior reproductive tracts in excess of amounts that could …

A Flow Cytometric Approach To Assessing The Environmental And Physiological Status Of Phytoplankton, Serge Demers, Kimberly Davis, Terry L. Cucci

CCPO Publications

No abstract provided.

Phytoplankton Composition In A Borrow Pit Lake In Virginia, Seba B. Sheavly, Harold G. Marshall

Biological Sciences Faculty Publications

The phytoplankton assemblages in Lake Trashmore, Virginia, a borrow pit, were dominated by centric diatoms and cyanobacteria, with seasonal pulses of cryptomonads, euglenoids, and chlorophyceans. Ninety species were identified and their abundance levels noted for a 12-month period.

Community Responses To Variable Predation: Field Studies With Sunfish And Freshwater Macroinvertebrates, Mark J. Butler Iv

Biological Sciences Faculty Publications

The impact of variable predation by bluegill sunfish on macroinvertebrate prey in a North Florida lake is examined. Variable predation may occur in many systems and may contribute substantially to the spatial heterogeneity, temporal inconstancy and species composition of prey communities.

Patchy, temporally variable predation characterized middepth and deep lake habitats, whereas in the shallow zone predation was relatively constant and homogeneous. Predation varied significantly every 2-4 wk in the mid-depth zone, but varied little between consecutive weeks or days. Caging experiments revealed that variable predation altered prey community composition and increased the mean size and size range of some …

Are Artificial "Witham" Surface Collectors Adequate Indicators Of Caribbean Spiny Lobster, Panulirus Argus, Recruitment?, Mark J. Butler Iv, William F. Herrnkind

Biological Sciences Faculty Publications

Understanding the local dynamics of Caribbean spiny lobster (Panulirus argus) postlarval influx, settlement, and recruitment may be essential for the responsible management of this important and heavily exploited resource. Most lobster recruitment research programs in the Caribbean employ derivations of the "Witham"-type surface collector to monitor postlarval (puerulus) lobster influx. However, the relevance of data obtained from surface collectors with respect to the estimation of actual puerulus influx, settlement, or recruitment to subsequent benthic juvenile stages remains untested. We investigated that relevance on regional (i.e., tens of kilometers) and local (i.e., tens of meters) scales by examining the …

Survival And Reproduction Of The Freshwater Grass Shrimp Palaemonetes Paludosus (Gibbes 1850) (Decapoda:Palaemonidae), In Saline Water, Brian Thomas Lowe

OES Theses and Dissertations

To determine the effects of salinity on adult and larval survival, egg deposition, egg hatching and metamorphosis, shrimp were held in the laboratory and exposed to treatment salinities ranging from O to 35 ppt. Tests on adult survival indicate a 96 hour LC-50 between 30 and 35 ppt. Longer term tests on adult survival showed high mortality in salinities greater than 15 ppt. Shrimp became ovigerous in salinities of O - 20 ppt with egg hatching and metamorphosis limited to O - 5 ppt. Starved- larvae hatched from field captured ovigerous females in O ppt were able to metamorphose in …

Interactions Between Aquatic Chromogenic Bacteria And Pathogenic Vibrio Spp., John Louis Harris

Biological Sciences Theses & Dissertations

Interactions between populations inhabiting an ecosys­tem are responsible, in large part, for determining which species coexist in that ecosystem. In this study, interac­tions between selected Vibrio species, V. alginolyticus and V. anguillarum, and marine heterotrophic, chromogenic bac­teria in aquatic microcosms were investigated. The ultimate goal of this project was to evaluate the feasibility of ex­ ploiting competitive interactions as a means to biologically control growth of the pathogenic marine bacteria, V. alginolyticus and V. anguillarum. In the majority of ex­periments (14/16), if chromogenic species were allowed to develop stable populations before a Vibrio spp. was intro­duced into a …

A Method For The Large Scale Purification Of Hcg (Human Chorionic Gonadotropin) From The Urine Of Pregnant Women, Chun-Shyan Kuo

Chemistry & Biochemistry Theses & Dissertations

A large scale preparation of human chorionic gonadotropin (HCG) from the urine of pregnant women was accomplished by using kaolin adsorption, NH₄OH extraction and DEAE-cellulose ion exchange. A recovery about 81% of HCG and a specific activity in the 2,000-3,000 IU/mg range was achieved using this purification method.

Two HCG activity fractions, HCG I & HCG II, were isolated from DEAE-cellulose chromatography by a stepwise sodium chloride gradient elution. HCG I was eluted at 0.01-0.02 M NaCl while HCG II was eluted at 0.12-0.02 M NaCl.

The differences between HCG I and HCG II have been studied. The …

Vertical Distribution Of Phytoplankton Populations Along The Northeastern Continental Shelf Margin Of The United States, Bruce Burwell Wagoner

Biological Sciences Theses & Dissertations

A study of phytoplankton vertical distribution at six stations along the northeast continental shelf of the United States was conducted in April 1984.

A total of 168 taxa were identified from nine phylogenetic groups collected at depths up to 150 m. Highest cell concentrations and cell volumes were in the upper 30 m. Greatest cell concentrations were produced by diatoms and a pico-nanoplankton component, with cell volumes mainly the product of diatoms and dinoflagellates. A high degree of variability was observed between phylogenetic groups within each station, but less variability was noted for phylogenetic categories at different stations.

Little difference …

The Synthesis And Evaluation Of 5-Phenyloxazolidines As Potential Cardiovascular Drugs, Tammy C. Wang

Chemistry & Biochemistry Theses & Dissertations

Drugs such as adrenoceptor antagonists and certain centrally acting agents are known to lower blood pressure and thus serve as clinically useful antihypertensive agents. Norepinephrine 4, a natural ∝-adrenoceptor agonist, is the major agent associated with increased blood pressure in the periphery. Based on a careful structure-activity comparison, a series of substituted oxazolidines, 20, 21, 22 and 23, have been designed as possible antihypertensive candidates. Specifically, 22 and 23 have been synthesized to serve as potential norepinephrine antagonists.

Preliminary evaluation of these compounds indicated that they were not antihypertensive in nature. The more active compound, 23, …

The Development And Comparative Morphology Of The Mandibular Symphysis In Salamanders, Jennifer Lorenz Elwood

Biological Sciences Theses & Dissertations

Despite the extensive literature on salamander cranial morphology, few authors mention the structure or development of the mandibular symphysis. Adult specimens representing eight caudate families and larval Ambystoma opacum, representing nine developmental stages, were evaluated histologically to determine the structure and development of the mandibular symphysis.

From this analysis it was determined that early in the ontogeny of the mandibular symphysis Meckel's cartilages are separated by a band of undifferentiated cartilage. As development progresses, this band of undifferentiated cartilage gradually transforms into a wedge of fibrocartilage which fuses to Meckel's cartilages.

Symphyseal morphologies of the adult caudates could be broken …

A Review Of The Pacific Members Of The Gobiid Fish Genus Bollmannia Jordan, Robin L. Bedenbaugh

Biological Sciences Theses & Dissertations

The Pacific members of the genus Bollmannia Jordan 1890 comprise seven species of gobies distributed from Baja California to Peru and west to the Galapagos Archipelago.

Previous authors recognized nine nominal species, all known only from their brief original accounts. Those accounts do not allow for proper discrimination of the species. All nominal species were re­ examined using meristic, morphometric, and pigment-pattern characteristics. Three of the nine nominal species are herein considered synonymous with previously described forms. The six valid nominal species are redescribed, a new species is described, and a key and illustrations are provided for the seven valid …

The Characterization Of Ribosomal Rna Gene Chromatin From Physarum Polycephalum, Sally A. Amero, Vicky L. Montoya, Wendy L. Murdoch, Roy C. Ogle, John L. Keating, Robert M. Grainger

School of Medical Diagnostics & Translational Sciences Publications

We have isolated ribosomal RNA gene (rDNA) chromatin from Physarum polycephalum using a nucleolar isolation procedure that minimizes protein loss from chromatin and, subsequently, either agarose gel electrophoresis or metrizamide gradient centrifugation to purify this chromatin fraction (Amero, S. A., Ogle, R. C., Keating, J. L., Montoya, V. L., Murdoch, W. L., and Grainger, R. M. (1988) J. Biol. Chem. 263, 10725-10733). Metrizamide-purified rDNA chromatin obtained from nucleoli isolated according to the new procedure has a core histone/DNA ratio of 0.77:1. The major core histone classes comigrate electrophoretically with their nuclear counterparts on Triton-acid-urea/sodium dodecyl sulfate two-dimensional gels, although they …

Comparative Analysis Of The Effects Of Visual And Auditory Stimuli On Avian Mobbing Behavior, C. Ray Chandler, Robert K. Rose

Biological Sciences Faculty Publications

Both visual and auditory stimuli elicit avian mobbing behavior, but there is little comparative information on their isolated and additive effects. Using three combinations of two experimental stimuli (mount and tape of an Eastern Screech-Owl, Otus asio) we tested the effects of stimuli on the frequency, intensity, and duration of avian mobbing behavior. Of 169 mount-only trials, only 11 (6.5%) were successful in attracting birds. Tape-only (n = 169) and mount-and-tape (n = 170) were equally successful in attracting birds (approximately 85% of all trials), but mount-and-tape trials were more likely to initiate mobbing behavior. Birds responding …

Modulation Of Queuine Uptake In Cultured Human Fibroblasts By Phorbol Esters And Interferons, Debra L. Crane

Chemistry & Biochemistry Theses & Dissertations

Queuosine, a nucleoside found exclusively in the first position of the anticodon of transfer RNA (tRNA), is generated post-transcriptionally in an exchange of guanine for queuine by the modifying enzyme tRNA-guanine ribosyltransferase. Phorbol ester tumor promoters were shown to induce queuine hypomodified tRNA, and that phorbol ester action was due, in part, to inhibition of queuine transport across the cell membrane. An unidentified protein designated conditioned medium factor (CMF) that potentiated a phorbol-induced inhibition of queuine uptake was also documented. We suggest here that phorbol ester-induced inhibition of queuine uptake is not a significant factor in inducing queuine-deficient tRNA although …

The Application Of The Peabody Developmental Motor Scales Administered To 20 Developmentally Delayed Children, Jan H. Henderson

Community & Environmental Health Theses & Dissertations

The purpose of this research was to provide physical and occupational therapists with empirical data and clinical information that will enable them to better understand and utilize the Peabody Developmental Motor Scales (PDMS) in the assessment of children who potentially may need physical and/or occupational therapy. The PDMS was administered to 20 developmentally delayed children between the ages of 24 and 83 months, who were receiving both physical and occupational therapy in the Chesapeake Public School System. The PDMS was also administered to 20 normal subjects between the ages of 24 and 77 months that were volunteers from the PTA …

A Light And Electron Microscopic Study Of The Rat Olfactory Tubercle: Normal Morphology And Acetylcholinesterase Localization, James Curtis Woodley

Biological Sciences Theses & Dissertations

A cytoarchitectural analysis of the rat olfactory tubercle using Nissl-stained coronal sections revealed that the dense cell layer (DCL) consisted of medium sized striatal cells in the cortical regions and small sized "granule" cells in the cap regions. Also delineated from this experiment was a rim of neuropil, nearly devoid of neurons as well as neuronal processes, outlining the islands of Calleja. Acetylcholinesterase (AChE) localization utilizing light microscopy revealed that the olfactory tubercles (OT) contained AChE-positive fibers that were orientated dorsoventrally in the molecular and multiform layers. The DCL consisted of only fibers en passant and putative terminals. Diisopropylfluorophosphate (DFP) …

Seasonal Phytoplankton Assemblages In The Nansemond River, Virginia, Cindy Eleanor Shomers

Biological Sciences Theses & Dissertations

A monthly phytoplankton study was conducted on the Nansemond River from November 1984 to October 1985. Light microscopy was utilized to characterize the resident populations, their cell concentrations and to provide a general comparison to other regional studies of river systems considered more polluted. The results divided the flora into two major categories. The first group was a pico-nanoplankton component composed of Cyanobacteria and Chlorophycean cells 1-10 um in diameter. The second group was a microplankton assemblage of Bacillariophyceae, Dinophyceae, Cryptophyceae, Chlorophyceae, Cyanobacteria and Euglenophyceae. The pico-nanoplankton had a unimodal abundance pattern with peak concentrations occurring in spring. The microplankton …

Effects Of Ammonia, Salinity And Oxygen On The Growth And Energetics Of The Grass Shrimp, Palaemonetes Pugio, Ahmad Mohammed Altayaran

Biological Sciences Theses & Dissertations

The growth and energy budget of juvenile grass shrimp, Palaemonetes pugio, were examined under various combinations of ammonia, salinity and dissolved oxygen. Experiments were performed to determine the effects of multiple stresses on the growth and physiological processes of the shrimp. The experimental design also allowed an evaluation of the effectiveness of several techniques for determining the productivity potential of aquatic animals exposed to stress.

A flow-through system was used to produce combinations of ammonia concentrations (0, 3, 6 and 12 mg/l) and salinities (20, 25, 30 and 35 ppt) for 21-day tests. The tests were conducted at high …

Molecular Study Of The B19 (Human) Pathogenic Parvovirus, Jamshed Ayub

Theses and Dissertations in Biomedical Sciences

The B19 (human) parvovirus is a small single stranded DNA virus of 5.4 kilobases. B19 is specific for erythroid progenitor cells and has been propagated in vitro only with human erythroid bone marrow. Replication of viral DNA and the viral protein products of B19 appear similar to those of other animal parvoviruses. However, B19 differs from other parvoviruses in some important aspects, which include the initiation of all transcripts at a strong left side promoter (p6) and the absence of a functional internal promoter. B19 has an unusual transcription map which is described in this study.

The transcription map of …

Callianassa Trilobata (Crustacea: Thalassinidea) Influences Abundance Of Meiofauna And Biomass, Composition, And Physiologic State Of Microbial Communities Within Its Burrow, Fred C. Dobbs, James B. Guckert

OES Faculty Publications

Biochemical and traditional methods were used to determine the influence of Callianassa trilobata on microbiological and meiofaunal communities within its large, highly consolidated burrow. Sediment was collected from the lining of the shrimp's burrow, the burrow matrix, and ambient, subsurface sediment. The lining and matrix were composed of poorly sorted, fine-grained material compared to sandy ambient sediment. Meiofauna, predominantly nematodes, were most abundant in ambient sediment, not in the burrow as has been found for other species of macrofauna. Concentrations of chlorophyll a were very high in the lining, consistent with the suggestion that C. trilobata lines its burrow walls …

Microbial Food Resources Of The Macrofaunal-Deposit Feeder Ptychodera Bahamensis (Hemichordata: Enteropneusta), Fred C. Dobbs, James B. Guckert

OES Faculty Publications

Biochemical and traditional analyses were used to characterize the microbial food resources and digestive efficiency of Ptychodera bahamensis, an enteropneust hemichordate. Sediment was collected from freshly extruded fecal casts and adjacent feeding depressions. There were no significant differences between casts and depressions in median grain size, percent silt-clay, density of total meiofauna and of nematodes, and concentrations of chlorophyll a and phaeophytin. Nematodes in casts had a median diameter greater than those in depressions. Measures of total, viable microbial biomass were 30% (total phospholipid, ester-linked fatty acids) and 49% (extractible phospholipid phosphate) lower in casts. Concentrations of 33 fatty …

The Relationship Between Multiple Health Factors, Demographics, And Body Weight, Glenda J. Potter

Community & Environmental Health Theses & Dissertations

The purpose of this study was to test the relationship between regular aerobic exercise and body weight. It was the intent of this study to determine if a person who regularly exercises at either high or moderate levels can maintain their body weight at desired levels as specified by the Body Mass Index (BMI). The participants in this study were selected from hospital employees, class members of aerobic classes and/or adult walkers/joggers. There were 38 participants-- 13 males and 25 females.

A self administered questionnaire and a 3-day, 24-hour dietary log were identified to comprise the instrument as well as …

Reactions Of Aqueous Chlorine In The Gastric Fluid Of The Rat, Michael Gary Nickelsen

Chemistry & Biochemistry Theses & Dissertations

Gastric fluid was recovered from Sprague-Dawley rats that had been fasted for 24 hr or 48 hr and administered 4 mL deionized water. The protein, carbohydrate and chloride ion content of the gastric fluid was determined.

When gastric fluid is chlorinated with radiolabeled chlorine to concentrations between 323 and 375 mg/L, analyzed by high performance chromatography followed by liquid scintillation counting, as much as 59% of the radiolabeled chlorine was associated with organic components of the gastric fluid.

Model studies with the aromatic amino acids and the protein pepsin showed the formation of chlorinated analogs. Two chlorinated amino acid derivatives …

Age And Growth Of The Tautog, Tautoga Onitis (Pisces: Labridae), From Lower Chesapeake Bay And Coastal Waters Of Virginia, E. Brian Hostetter

Biological Sciences Theses & Dissertations

The tautog, Tautoga onitis (Pisces: Labridae), is rapidly gaining popularity in Virginia by anglers, spearfishermen and specialized commercial interests. In Virginia, tautog are seasonally abundant on hard bottom substrates in nearshore (ca. 2-10 m) habitats and inhabit offshore wrecks and reef areas (ca. 10-30 m) year round. Habitat restriction and slow growth of the species coupled with recent technological advances in marine electronics which simplify locating tautog populations by user groups may contribute to overexploitation of tautog within the region.

Tautog were collected over a two year period from the lower Chesapeake Bay and nearshore waters of the Atlantic Ocean …

Effects Of Ethanol And Caffeine Administered Maternally On Neonatal Adrenocortical Function, Rhonda L. Mullins Rohlfing

Biological Sciences Theses & Dissertations

Two investigations were conducted to determine the effects of maternally administered ethanol and caffeine on neonatal adrenocortical function. In the ethanol study, pregnant female rats were fed a liquid diet in which 35% of the sucrose calories were removed and replaced with ethanol. Dams in the caffeine study were injected with 25 mg/kg/day caffeine in saline solution. Within 24 hours of parturition, neonatal rats in both studies were sacrificed. The adrenal glands were incubated in vitro for one hour and media were analyzed for corticosterone content. Significant adrenal weight differences were found in both studies. The ethanol group pups were …

Use Of 52Cr For The Quantitative Determination Of Red Cell Volume, Claude Michael Hanbury

Chemistry & Biochemistry Theses & Dissertations

Chromium-52 has recently been suggested for use as a new agent to label red cells for the in vivo quantitation of red cell volume (1). In this paper, the development and validation of a routine ⁵²cr labeling procedure is described.

The accuracy, precision, and detection limits of chromium analysis by Zeeman effect atomic absorption spectroscopy was evaluated in the concentration range of 1 - 10 ug Cr/L.

Red cell chromium uptake was evaluated as a function of time, temperature, and concentration. Red cells labeled with a 2.5 mg/L chromium solution for 30 minutes at room temperature exhibited optimal label …

Decomposition Of Roots In The Great Dismal Swamp, Edward G. Tupacz

Biological Sciences Theses & Dissertations

The decomposition rates of roots to a depth of 40 cm were estimated by two methods in four plant communities in the periodically flooded Great Dismal Swamp. Modified litter bags and a core method were simultaneously employed on three flooded sites and an unflooded mixed hardwood site. Reciprocal samples (litter from each of the other sites) were placed on each site to examine the effects of litter composition.

For the litter bags, the cedar and maple - gum sites displayed the lowest mean decay rate. However, reciprocal samples showed that roots from the cedar and mixed hardwood sites decayed the …