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A Scanning Electron Microscopy Comparison Of The Effects Of The Arkansas Stone And The Ida-Hone Ceramic Stone On Curet Sharpness And Root Smoothness, Marian Gayle Rubino

Dental Hygiene Theses & Dissertations

Purpose: The purpose of this study was to determine if there are statistically significant differences between the Arkansas sharpening stone and the Ida-Hone ceramic sharpening stone in producing a sharper cutting edge on dental curets, and to determine if there is a statistically significant difference between the degree of root smoothness achieved by the sharpened curet cutting edges on extracted human teeth.

Methods: A two-group, randomized subject (n=39), double blind, post-test only design was employed using 39 factory new Hu-Friedy 11/12 gracey curets. Curets in group one were sharpened using the Ida-Hone ceramic stone, curets in group two were sharpened …

Trichodesmium Spp.: Numerical Studies Of Resource Competition, Carbohydrate Ballasting, And Remote-Sensing Reflectance, Tonya Denise Clayton

OES Theses and Dissertations

In recent years, a new appreciation for the role of diazotrophy in the oceans has emerged. This dissertation reports on three modeling studies designed to investigate ecological processes associated with Trichodesmium spp., the most conspicuous marine diazotroph: (1) characterization of a generalized model Trichodesmium and issues of macronutrient resource competition; (2) carbohydrate ballasting by Trchodesmium and implications for the formation of surface accumulations; and (3) the vertical distribution of Trichodesmium and implications for detection from space.

The first study focuses on issues of nitrogen and phosphorus competition and ecosystem structure. It utilizes a simple ecosystem model that includes dissolved nitrogen …

The Rhetoric And Reality Of Famine In Early Modern Europe, Karen Russell Adams

History Theses & Dissertations

Famine in early modern Europe was a reoccurring phenomenon that caused stress on individuals and their societies. In most historical accounts of famine, authors have placed emphasis on either the physical aspects of starvation, including studies of famine victims, both live and post mortem, or the disastrous effects of such crises on demographics. On occasion, a researcher has instead probed the accounts of famine left behind by its victims. This essay is an attempt to correlate famine narratives with the biological aspects of starvation.

In order to blend the physical and social aspects of famine, this researcher has investigated three …

The Effect Of Multiple Pulses On Bacteria, Ramy El-Sayed Aly

Electrical & Computer Engineering Theses & Dissertations

Pulsed electric fields are widely used for bacterial decontamination of water and liquid food [I]. Depending on pulse amplitude and duration, a certain percentage of the bacteria suffer irreversible damage and, consequently, cell death. We have explored the effect of microsecond pulses of 13 kV/cm and 15 kV/cm electric field amplitude on the viability of Escherlchia coli. The pulse duration was varied from 4 μs to 32 μs, and the pulse number of 4 μs pulses from one to eight, Finally, the effect of separation between pulses was studied. The pulses were generated by means of a generator where …

Benthic Biological Monitoring Program Of The Elizabeth River Watershed (2000), 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 second year of sampling in 2000. 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 …

A Longitudinal Study Examining The Stability Of Occupational Stressors Identified By Nursing Home Administrators, Gay Lynne Andrucci-Armstrong

Health Services Research Dissertations

As a result of the ever changing and expanding role of the nursing home administrator in conjunction with the stricter legislation governing nursing facilities over the past decade and the graying of America, a study specific to this population was warranted. The purpose of this study is to determine the relative change in the self-reported occupational stressors of nursing home administrators over a five year period (December 1994 to June 1999) secondary to the increased regulatory climate of the nursing home industry.

This study was carried out in three phases and included all practicing nursing home administrators in Virginia. Phase …

Interactions Among Murine Cytomegalovirus Us22 Family Gene Products That Influence Viral Pathogenesis, Zaruhi Karabekian

Theses and Dissertations in Biomedical Sciences

Cytomegalovirus (CMV) is a complex, ubiquitous herpesvirus that is characterized by acute, chronic, and latent infections. Monocytes-macrophages are the key target cell type involved in pathogenesis, which is most effectively studied using the murine model of CMV infection. Previously three murine CMV (MCMV) genes (M139, M140, and M141) were identified to regulate viral expression in cultured macrophages and in mice. These genes are members of the US22 gene family with respect to HCMV homology. There is no function assigned to the proteins encoded by these genes. However, deletion of M139, M140, and M141 significantly curtails growth of MCMV in macrophages …

Isoetes Mattaponica (Isoetaceae), A New Diploid Quillwort From Freshwater Tidal Marshes Of Virginia, Lytton John Musselman, W. Carl Taylor, Rebecca D. Bray

Biological Sciences Faculty Publications

Isoetes mattaponica is a rare quillwort of freshwater tidal rivers of eastern Virginia with a somatic chromosome number of 2n = 22. Megaspores have low rugulate muri on both the proximal and distal surfaces; the girdle is broad. Microspores are echinate-spinose with ornamented spines. Isoetes mattaponica may be one of the parents of several polyploids in the Southeastern United States.

An Examinaton Of The Enhanced Primary Care Model For The Organization Of Team Care In Managing Type 2 Diabetes Mellitus In The Elderly Population, Carolyn Morcom Rutledge

Health Services Research Dissertations

The healthcare system is faced with overwhelming demands as a result of the growing elderly population, especially those with chronic illnesses. One disease that significantly impacts the morbidity and mortality of the elderly population, especially the minority and poor population, is type 2 diabetes. This population often lacks access to resources and quality healthcare that may be due to inadequate knowledge by the patients and their healthcare providers regarding available services. Current models of healthcare have not been effective in meeting the healthcare demands of this population. The purpose of this study was to evaluate the effectiveness of the Enhanced …

Dynamical Sedimentary Models Of Shallow Marine Environments, Yong Zhang

OES Theses and Dissertations

This treatise represents a contribution of quantitative, dynamical sedimentary modeling to the analytical understanding of sedimentary processes in shallow marine environments. The dynamical sedimentary models in this treatise numerically simulate the sedimentary processes from an event time scale, based on the fundamental physics of sediment dynamics in coastal and shelf depositional environments, to a longer, facies time scale. The simulated geologic processes serve to the illustrate shoreface equilibrium profile, shelf storm bed generation, and the shelf sedimentary facies system.

This treatise presents a nearshore profile evolution model for the abandoned Huanghe Delta, a two-dimensional storm deposition model, and a sedimentary …

Systematics Of The Subterranean Amphipod Genus Stygobromus (Crangonyctidae) In Western North America, With Emphasis On Species Of The Hubbsi Group, Daqing Wang

Biological Sciences Theses & Dissertations

This dissertation presents a study of the systematics of the subterranean amphipod genus Stygobromus of family Crangonyctidae in western North America. A total of 53 species of Stygobromus from western North America (including one species from Wisconsin) are recognized, 28 of which are new to science. All species are described and illustrated using external morphological features. A key to the western North America species of Stygobromus is given, as well as a summary of habitats of the species.

Cladistic analyses are conducted using 32 external morphological characters and two categories of outgroup choices: “all-zero” theoretical ancestor and three non-Stygobromus …

Estrogen Regulation Of The Pregnant Baboon Placental 11Β-Hydroxysteroid Dehydrogenase (11Β-Hsd)-Catalyzed Metabolism Of Cortisol And Cortisone And Its Effect On The Development Of The Fetal Hypothalamic-Pituitary-Adrenal Axis, William Adair Davies

Theses and Dissertations in Biomedical Sciences

Pepe and Albrecht previously demonstrated that the estrogen-regulated change in transuteroplacental metabolism of cortisol (F) and cortisone (E) from preferential reduction (E to F) at midgestation to oxidation (F to E) near term results in a decline of bioactive cortisol crossing the placenta and reaching the fetus culminating in activation of the hypothalamic-pituitary adrenal axis of the baboon and the ontogenesis of rate-limiting steroidogenic enzymes culminating in de novo F secretion. Protein kinase A (PK-A) activity in the baboon fetal adrenal gland cytosolic fraction was increased 2-fold both at term [day 165 of gestation (term = 184 days)] and following …

Circulation, Vol. 8, No. 1, Center For Coastal Physical Oceanography, Old Dominion University, Ann E. Gargett

CCPO Circulation

Spring 2001 issue of CCPO Circulation featuring article "Remarks from a New Arrival: Dr. Ann Gargett"

Psychophysiological Measures And Performance Effects In An Adaptive Sustained Attention Task, Gerald Alan Hadley

Psychology Theses & Dissertations

This experiment examined the effect of a biocybernetic system that had been successfully used to control an adaptive automation compensatory tracking task (Freeman, Mikulka, Prinzel, & Scerbo, 1999; Pope, Bogart, & Bartolome, 1995). The present study applied this adaptive automation system to a vigilance task. Recordings of EEG activity were used to derive an index of task engagement, beta/(alpha+ theta). A training session was used to establish a baseline level of this index. Index levels above baseline reflected an increase in arousal, while levels below baseline indicated decreased arousal. Three groups (production, reception, and control) performed the task which presented …

Beneath The Black And Blue: The Child Abuse-Delinquency Connection, Heather M. Baltodano

Sociology & Criminal Justice Theses & Dissertations

The purpose of this research is to examine the child abuse-delinquency relationship, as well as mediating variables that may influence that relationship, such as parental attachment, witnessing family violence, and negative life events. Much of the research on this topic utilizes official government statistics and substantiated child abuse cases, which research has shown to be an undercount of the actual incidents of child abuse. This analysis utilizes the data resulting from the 1992 National Youth Victimization Prevention Survey (NYVPS) in which 2000 children between the ages of 10 and 16 were interviewed by telephone. This research examines the impact of …

Investigations Into The Innate Resistance Of The Tick, Dermacentor Variabilis, When Challenged With The Bacterium, Escherichia Coli, Shane Michael Ceraul

Biological Sciences Theses & Dissertations

In addition to the soluble response, many invertebrates control bacterial infections by means of phagocytosis or melanotic encapsulation. In some insects, Escherichia coli growth is reported to be inhibited by aggregation/encapsulation. Soluble and phagocytic responses to bacterial challenge have been reported in ticks, but evidence of an aggregation/encapsulation response was reported only for inanimate (araldite) implants. This study was done to determine how ticks control infection by E. coli. Ticks were challenged by direct inoculation of bacteria into the hemocoel cavity. Using plate counts, no viable E. coli were detected I hour post-inoculation. A direct fluorescence assay (DF A) …

Seasonal Phytoplankton Assemblages Of Five Ephemeral Ponds In York County, Virginia, Michelle R. Kokolis

Biological Sciences Theses & Dissertations

Five ephemeral ponds were identified in and around the Grafton Ponds Natural Area Preserve, approximately 56 km north of the City of Norfolk, Virginia. These ponds, which are filled seasonally by precipitation and groundwater discharge, range from 0.1 ha to 2 ha in size and from 4 cm to 3 meters in depth. Ponds for the study were chosen based on variations in their size, depth, basin cover material, canopy openness, and historical inundation period. The purpose of this study is to relate differences in the phytoplankton assemblages to the physical and chemical characteristics of the ponds. All five ponds …

Effects Of Human Disturbances On The Behavior Of Dabbling Ducks, Melissa Lynn Pease

Biological Sciences Theses & Dissertations

Disturbance of wintering and migrating birds by human activities can cause birds to expend energy in avoidance of humans and reduces the time available for resting and feeding at a time in the annual cycle when fat deposition and energy conservation are important. Also, human disturbances can effectively cause habitat loss by displacing birds from feeding or resting habitat. Managers of natural resources are increasingly faced with decisions about the types and amounts of public use that should be allowed without lowering the value of the resource for wildlife. In order for managers to make decisions about how to minimize …

A Comparison Of Phytoplankton Communities In Lake Prince And The Western Branch Reservoir, Suffolk, Virginia, Cara Marie Muscio

Biological Sciences Theses & Dissertations

Lake Prince and the Western Branch Reservoir are two eutrophic bodies of water located in Suffolk, Virginia. Lake Prince and its two small tributaries join the Western branch via a constructed spillway. This lake system is a source of water for the surrounding municipalities, and a recreational area for community citizens. In the past, these bodies of water had repeated incidents of low oxygen and nuisance algal blooms, particularly cyanobacteria species. As a result aerators have been installed in the main body of both Lake Prince and the Western Branch Reservoir. In addition, a pipeline has been installed from North …

The Effect Of Nitrogen Fertilization On Short-Term Fine Root Dynamics In A Barrier Island Dune Community, John Walter Hutton

Biological Sciences Theses & Dissertations

Fine root dynamics are an important yet poorly understood component of terrestrial ecosystems. In recent years a number of researchers have focused on fine root dynamics; their work has looked at patterns across one or multiple growing seasons on a scale of monthly measures. The purpose of this study was to add to the overall understanding by looking at fine root dynamics on a shorter temporal scale. Minirhizotron observation tubes were used to assess the effect of nitrogen fertilization on short-term fine root dynamics in a nutrient limited, barrier island dune system. Root length elongation and mortality rates followed expected …

Ice Storm Damage To Virginia Coastal Plain Forests During The Christmas 1998 Ice Storm, Peter Elstner, Stewart Ware

Virginia Journal of Science

On December 23-25, 1998, a major ice storm struck southeastern Virginia. The storm-deposited glaze ice felled trees and limbs, causing a power outage and highway blockage. Between February and April, 1999, we recorded occurrence, severity, and type of damage to trees over 2.5 cm dbh in nine mostly gently sloping plots in Matoaka Woods at the College of William and Mary. Frequency and severity of damage varied with species and with size of trees. Canopy damage occurred in 75% of large Fagus grandifolia trees, but in only 6% of small Sassafras albidum stems. As a group, small (2.5 to 15 …

Comparison Of Spawning And Non-Spawning Substrates In Nests Of Species Of Exoglossum And Nocomis (Actinopterygii: Cyprinidae), Eugene G. Maurakis, Terre D. Green

Virginia Journal of Science

Percent composition of pebble size classes from spawning and non-spawning substrates of nests were used to test the hypothesis that distribution of pebble sizes is random in nests of Exoglossum laurae, Exoglossum maxillingua, Nocomis leptocephalus, Nocomis micropogon, Nocomis platyrhynchus, and Nocomis raneyi in Virginia. In nests of the two species of Exoglossum, spawning areas (i.e., upstream bases of nests) contain significantly greater amounts of the 6.0 mm size class, and significantly smaller amounts of the 2.5 mm size class of stones than do non-spawning areas. Spawning areas (i.e., pits) in nests of N. leptocephalus contain …

Environmental Effects On Yield And Agronomic Traits Of Common Bean (Phaseolus Vulgaris L.), Tadesse Mebrahtu, Teklu Andebrhan, Ali Mohamed

Virginia Journal of Science

Common bean (Phaseolus vulgaris L.) demand is increasing with an alarming rate around the world, especially in Latin America, Africa, and Asia. Therefore, increase bean yield per hectare is the best way to meet the world demand rather than expansion of area under cultivation. The objectives of this experiment were to determine the genotypic variations for green bean and dry seed yield and magnitude of genotype x environment interaction effects on yield and yield components of common bean. Thirteen genotypes were planted during the 1992, 1994, and 1995 growing seasons. Genotypes were evaluated for green pod and seed …

Isolation And Fusion Of Cotton Protoplasts, Michael H. Renfroe, Ronald C. Hartwig, Roberta H. Smith

Virginia Journal of Science

Protoplasts were isolated from five species of Gossypium. Protoplast yield and viability were affected by incubation conditions, osmolarity, purification procedures, and cell source. Using an optimized procedure, highly viable protoplasts were isolated from cell suspensions, callus cultures, and leaf tissue of G. hirsutum, G. arboreum, G. klotzschianum, G. harknessii, and G. herbaceum. Protoplasts of G. harknessii were enucleated and successfully fused with protoplasts of G. hirsutum.

Trachelomonas Spp. And Other Euglenophyceae Taxa In A Southeastern Virginia Lake, Harold G. Marshall

Virginia Journal of Science

Trachelomonas species from Lake Kilby, a reservoir lake in southeastern Virginia are described with supportive electron micrographs. The most abundant Trachelomonas species wereT. hispida and T. volvocina. Other members of the Euglenophyceae occurring in this lake are identified.

The Implications Of The Target-Area Hypothesis On The Population Dynamics Of The Spotted Spiny Lobster, Panulirus Guttatus, Denice N. Robertson

Biological Sciences Theses & Dissertations

The target-area hypothesis, based on the theory of island biogeography, predicts that larger islands are more effective at intercepting passive immigrants. Most marine invertebrates have meroplanktonic larvae and open population dynamics, so immigration to populations in isolated benthic habitats is primarily by pelagic larval recruits. Thus, recruitment to isolated habitat “islands” may be more continuous and predictable on large islands than on small ones. Consequently, populations on large islands should not only be larger than those on small islands, but should also have more evenly distributed size structures. These differences in size structure among populations in isolated habitats of differing …

Characterization Of Murine Cytomegalovirus M142 And M143 Essential Gene Products, Bridget Linette Dalton

Theses and Dissertations in Biomedical Sciences

Cytomegalovirus (CMV) is a species-specific virus belonging to the Herpesviridae family. This DNA virus causes severe disease or even death in newborns and immunosuppressed patients. Murine CMV (MCMV) provides an opportunity to study the role of various viral products in replication and pathology in the natural host. Successful replication of CMV in the host depends upon the expression of a cascade of viral genes: immediate early (IE), early (E), and late (L). To date only three MCMV IE proteins have been characterized (IE1, IE2 and IE3). Our laboratory recently identified a novel IE gene region within the Hind III I …

Urban Terrorism: Strategies For Mitigating Terrorist Attacks Against The Domestic Urban Environment, John J. Kiefer

Theses and Dissertations in Urban Services - Urban Management

This study identifies strategies to mitigate the impact of terrorist attacks against the domestic urban environment. It uses multiple qualitative research methods to identify patterns of attack used by terrorists against urban targets in the United States and suggest ways for policymakers to mitigate the effects of a terrorist attack through not only physical, but also organizational, political, legal, and social strategies. It uses case analysis, literature review, and interviews with experts in domestic terrorism preparedness to develop and suggest solutions.

Terrorism, as with other criminal acts, can best be met by implementing strategies to mitigate the impact of this …

Childhood Obesity And Its Relationship To Sedentary Behavior Patterns Vs. Other Independent Risk Factors Of Obesity Among Navy Dependent Adolescents, Shaye Lauren Arluk

Human Movement Studies & Special Education Theses & Dissertations

Background According to data gathered in the NHANES 1999 survey 14% of American children are now classified as obese, a 60% increase in prevalence from the NHANES II survey in 1976. Multiple research studies have looked at the role of dietary intake, heredity, and physical activity participation as independent risk factors of obesity with mixed results. However, sedentary behavior patterns, which have markedly increased in the past ten years, have not been extensively studied in relation to childhood obesity. The goal of this study was to focus on the relationship between various sedentary behaviors and childhood obesity.

Methods Two descriptive …

In Support Of A Rationally Managed Fishery: Age And Growth In Patagonian Toothfish (Dissostichus Eleginoides), Julian R. Ashford

Biological Sciences Theses & Dissertations

Patagonian toothfish (Dissostichus eleginoides) occur on the continental shelves and shelf breaks of southern South America and the Southern Ocean. Stock structure, critical to good fisheries management, can be inferred from growth differences between areas, but available growth data are compromised by inconsistencies in age estimation methods, sampling and sample sizes, and techniques used to derive estimates. I asked the scientific question: how is growth in Patagonian toothfish structured spatially within the Southern Ocean? I developed a multi-stage randomized design to sample fish caught by commercial longline, and an age estimation methodology. Because toothfish are difficult to age, …