Digital Commons Network^™

Presence Of Haemosporidia And Flaviviruses In Breeding Prothonotary Warblers (Protonotaria Citrea): An Analysis Of Spatial And Temporal Trends In Infection Prevalence And Associations With Reproductive Success, Elena Grillo

Theses and Dissertations

As Neotropical migratory birds, Prothonotary Warblers are exposed to parasites in both tropical and temperate regions and may act as dispersal agents between geographic areas. This study identifies the prevalence of Haemosporidia, West Nile Virus (WNV), and St. Louis Encephalitis virus (SLEV) in this species. A total of 71.6% of captured Prothonotary Warblers were infected with Haemosporidia during the 2008 breeding season, and infection prevalence increased throughout the season. This temporal change in prevalence is likely due to infection relapse and transmission of new infections. No correlations between reproductive effort and infection status were observed, nor were any associations between …

The Walter And Inger Rice Center For Environmental Through Time: A Study In Environmental Change, Human Land Use And Its Effects Along The Lower James River, Chris Egghart

Theses and Dissertations

Historic cartographic sources, historical accounts, and ethnographic and archaeological data are used help reconstruct past settlement patterns and land uses that together acted to shape the changing cultural landscape of the Virginia Commonwealth University Walter and Inger Rice for Environmental Studies (Rice Center). The Rice Center is located in Charles City County along the north bank of the James River between Richmond and Williamsburg. Presented is a baseline description of the present day condition of the Rice Center property. This is followed by a detailed account of the physiographic and ecological changes that occurred along the Lower James River since …

An Environmental And Economic Assessment Of Future Municipal Solid Waste Disposal: A Case Study Of Select High Growth Regions Of Virginia., Joseph Krouse

Theses and Dissertations

This research analyzed environmental and economic factors associated with municipal solid waste (MSW) management of select high growth Planning District Commissions (PDCs) of Virginia. Current MSW management scenarios were compared to future hypothetical scenarios utilizing a regional landfill or waste-to-energy (WTE) combustion facility. Life-cycle inventory and full cost accounting methods of the Municipal Solid Waste Decision Support Tool, developed by the Environmental Protection Agency (EPA), were utilized to estimate annualized environmental emissions and economic costs. Model results and analysis indicate that a regional landfill would be the least cost intensive MSW management strategy in comparison to current management methods; however …

Commonwealth Times 2009-04-23

Commonwealth Times, 1969-

No abstract provided.

Hyperspectral Reflectance For Rapid Viability Assessment Of Bacillus Endospores, Jarrod Edwards

Theses and Dissertations

A study was conducted to optically determine the viability of the Gram +, endospore-forming bacterial genera Bacillus using a hyperspectral reflectance spectrometer. Endospores are a dormant, differentiated cellular capsule form taken by select bacteria to ensure survival when environmental conditions become unfavorable. Two species of Bacillus were used for this study, Bacillus megaterium and Bacillus subtilis. These endospores were killed using a chemical treatment of sodium hypochlorite or a physical treatment of heat and pressure in an autoclave. The treated samples along with viable samples were lyophilized to form a powder. A reflectance spectrometer measuring 350 nm to 2500 nm …

Elemental Composition And Nutrient Effect On The Uptake And Metabolism Of Dissolved Organic Carbon By Bacteria From A Temperate Region River, Anne Stuart

Theses and Dissertations

Rivers are arteries that connect land and sea, and provide a conduit and reactor for allochthonous and autochthonous organic carbon sources (OC) delivered to the coastal ocean. In comparison to marine waters, inland waters quantitatively represent only a fraction of the marine system; however, their importance to global C cycling maybe disproportional to its actual size. Inland systems are subject to multiple sources of OC (autochthonous and allochthonous) that vary individually in space and time with respect to their concentration and potential bacterial bioavailability. This study investigates the impact of high and ambient inorganic nutrient concentrations on the bacterial bioavailability …

The Responses Of Blue Crabs (Callinectes Sapidus) To Hypoxia/Hypercapnia In Freshwater, James Martin

Theses and Dissertations

The present research examined respiratory responses of blue crabs to long term (4, 13, and 21 days) hypercapnic hypoxia in freshwater at 23 C. Hypoxic conditions (50-60 & 75-85 mmHg O2) were induced by allowing the crabs to consume their oxygen supply, resulting in a hypercapnic induced decrease in pH that remained through the exposure. Postbranchial hemolymph responses to hypoxia/hypercapnia in freshwater demonstrate decreases in PO2, increases in PCO2, and decreases in pH. Lactate levels decreased over time, but hemocyanin concentration was highly variable with no trends. PH, lactate, and hemocyanin observations also demonstrated high variability and a variety of …

Role Of Bcl-2 Family Members To Promote Glucocorticoid –Induced Apoptosis By Mek Inhibitors In Leukemic Cells, Anila Rambal

Theses and Dissertations

Glucocorticoids (GC) are common components of many chemotherapeutic regimens for lymphoid malignancies. GC-induced apoptosis involves an intrinsic BCL-2 family-regulated pathway. It has been shown that BIM (BCL-2 interacting mediator of cell death), a BH3-only pro-apoptotic protein, is up-regulated by dexamethasone (Dex) treatment in acute lymphoblastic leukemia (ALL) cells. Furthermore, BIM is inactivated by extracellular signal-regulated kinase (ERK)-mediated phosphorylation. We therefore hypothesized co-treatment with Dex and MEK/ERK inhibitors would promote apoptosis in ALL cells through BIM up-regulation and activation. We show here that a MEK inhibitor, PD184352 synergistically enhances Dex lethality in CCRF-CEM (T-ALL) cells. Co-treatment with Dex and PD184352 results …

Factors Affecting Dissolved Oxygen Metabolism In Coastal Plain Streams Of Virginia, Julie Frank

Theses and Dissertations

I investigated seasonal and inter-site variation in factors influencing diel dissolved oxygen (DO) metabolism at four streams in the Virginia Coastal Plain. Data were collected monthly from January to August 2008 to characterize DO metabolism (diel DO amplitude, production, respiration), incident solar radiation (PAR), dissolved nutrients, fine benthic materials (mass, C:N, Chlα) and hydrology (discharge, water transit time, transient storage). Reach-scale metabolism estimates were determined using the one-station diurnal DO technique and transit time and transient storage were determined by conservative tracer additions. Incident solar radiation was the primary determinant of DO metabolism as streams experiencing higher light levels (Herring …

Patterns Of Abundance Across An Urban-Rural Gradient For Commonly Found Indigenous Arthropods, David Jones

Theses and Dissertations

Abstract Proof of concept for a continuous environmental sampling methodology that employs common terrestrial arthropods as environmental samplers was tested by analyzing pitfall, malaise and black light captures over a six month period over a replicated urban-suburban-rural gradient in Central Virginia. All arthropods captured at the nine sites were identified and assigned to aquatic, vegetation, or soil groups based on their association with these microhabitats. To offset variability in arthropod life history patterns and species abundance within habitat types, arthropod categories based on presence/absence data over the six month period were constructed to provide for sampling reliability within each microhabitat …

Coupling Of Autotrophic And Heterotrophic Plankton Food Web Components In The Tidal-Freshwater James River, Usa, Matthew Beckwith

Theses and Dissertations

Empirical studies have shown that algal- and detrital-based food web components are coupled in many pelagic systems as algal carbon enhances bacterioplankton production and growth efficiencies. Such phyto-bacterioplankton coupling impacts carbon flow through plankton food webs, yet the extent of coupling is poorly understood in systems receiving large amounts of allochthonous carbon. To investigate this issue, bacterioplankton abundance (BA) and community composition were compared to chlorophyll a concentrations and phytoplankton production in the tidal-freshwater James River (VA). BA averaged 107 cells mL-1 and was significantly related to chlorophyll a, phytoplankton production, and DOC concentrations. Analysis of DOC quality using fluorescence …

Commonwealth Times 2009-03-23

Commonwealth Times, 1969-

No abstract provided.

Commonwealth Times 2009-03-19

Commonwealth Times, 1969-

No abstract provided.

Hydrothermal Preparation Of Gd+3 -Doped Titanate Nanotubes: Magnetic Properties And Photovoltaic Performance, Hoda S. Hafez, M Saif, James T. Mcleskey Jr., M.S.A. Abdel-Mottaleb, I S. Yahia, T Story, W Knoff

Mechanical and Nuclear Engineering Publications

Pure and Gd+3 -doped titanate nanotubes (TNTs) materials were synthesized by a hydrothermal method. Their morphology, optical properties, thermal stability, and magnetic properties were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), UV-Vis spectroscopy, thermal analysis, and magnetic measurements. It was found that doping renders Gd+3-TNT visible light active and results in smaller crystallite size and larger surface area as well as higher thermal stability compared to pure titanate nanotubes. The estimated magnetic moments point to presence of weak antiferromagnetic interaction. Application of the prepared Gd+3-TNT for modifying conventional photoanodes in polymer solar cells was attempted. Preliminary results show …

Virginia Commonwealth University Commencement Program [2009], Virginia Commonwealth University

VCU Commencement Programs

No abstract provided.

Virginia Commonwealth University Fall Commencement Program [2009], Virginia Commonwealth University

VCU Commencement Programs

No abstract provided.

Invertebrate Colonization And Plant Architecture: The Influence Of Two Non-Native Milfoil Species, Elizabeth W. Rielly

Theses and Dissertations

The purpose of this study was to determine if the complexity and surface area of a macrophyte’s

structure has an influence on invertebrate colonization, and to determine the influence of two non-native species on invertebrate colonization. Three plant architectures were compared. Floating leaved plants were represented by the following species: Nuphar lutea, Nymphaea odorata, and Brasenia schreberi. Moderately dissected leaved plants were represented by Potamogeton natans, and highly dissected leaved plants were represented by two non-native species, Myriophyllum spicatum and Myriophyllum heterophyllum. The number of invertebrates/g dry biomass and the number of individuals/m², diversity, evenness, and richness were calculated for …

Commonwealth Times 2008-11-10

Commonwealth Times, 1969-

No abstract provided.

Commonwealth Times 2008-10-30

Commonwealth Times, 1969-

No abstract provided.

Commonwealth Times 2008-09-25

Commonwealth Times, 1969-

No abstract provided.

Commonwealth Times 2008-09-18

Commonwealth Times, 1969-

No abstract provided.

Commonwealth Times 2008-09-15

Commonwealth Times, 1969-

No abstract provided.

Plumage Ornamentation As An Indicator Of Female Age And An Influence In Male Mate Choice In Protonotaria Citrea, The Prothonotary Warbler In Virginia., Terry Smith

Theses and Dissertations

Flamboyant plumage and ornamentation is common and well-known in male birds; it serves as a sexual display to attract potential mates. While flamboyant plumage is less common and usually more subtle in female birds, it does occur in some species such as Dark-Eyed Juncos (Junco hyemalis) and Prothonotary Warblers (Protonotaria citrea). Prothonotary Warblers display relatively subtle sexual dimorphism. This study examines variations in tail spot patterns in Prothonotary Warblers and relates those variations to age in females. Females with fewer than six spots tend to be two years old or younger; females with six spots or more tend to be …

Making Time, Christine Coffey

Theses and Dissertations

We are living in an age where the quantity of information has exceeded its quality. No doubt the digital and information revolutions have provided the world with countless positive improvements, but they have also increased the speed at which we live and work to the detriment of the heath of our world. This project explores ways in which designers can aid in an effort to slow down in order to reinvigorate a more sustainable graphic design product.

Commonwealth Times 2008-04-21

Commonwealth Times, 1969-

No abstract provided.

Virginia Commonwealth University Fall Commencement Program [2008], Virginia Commonwealth University

VCU Commencement Programs

No abstract provided.

Virginia Commonwealth University Commencement Program [2008], Virginia Commonwealth University

VCU Commencement Programs

No abstract provided.

Virginia Commonwealth University Fall Commencement Program [Corrected Copy] [2008], Virginia Commonwealth University

VCU Commencement Programs

No abstract provided.

Beyond The Early Adopters: Examining The Potential For Car-Sharing In Richmond, Virginia, Steven P. Spears

Theses and Dissertations

Car-sharing is a membership-based mobility service that offers short-term vehicle rentals. Studies have shown that car-sharing can increase transportation sustainability by encouraging the use of public transit and reducing vehicle miles traveled. This thesis examines the potential for car-sharing in Richmond, Virginia through an attitude-based qualitative pilot study. Using the theory of planned behavior as a framework, urban and suburban residents were asked questions that measured car-sharing intention strength, mode choice habit, and life change effects. The study found that even among those with positive attitudes toward car-sharing, existing habits, lack of adequate commuting alternatives and the needs of non-driving …

Commonwealth Times 2007-11-19

Commonwealth Times, 1969-

No abstract provided.