Digital Commons Network^™

Physical And Biological Constraints On The Abundance Of Cyanobacteria In The James River Estuary, Brendan C. Trache

Theses and Dissertations

The tidal-fresh James River experiences recurring blooms of toxin-producing cyanobacteria, including Microcystis aeruginosa. However, cyanobacteria cell densities in the James are relatively low. Our purpose was to identify key factors suppressing cyanobacteria growth in the face of eutrophication. A mesocosm experiment was designed to test the effects of light, mixing and grazing on cyanobacteria abundance, with nutrients held constant. We predicted that toxic cyanobacteria would be most abundant under stagnant conditions, with enhanced light, with no bivalve grazers present. Abundances of indicator gene copies and phytoplankton counts supported this hypothesis. However, chlorophyll-a, phycocyanin, and the toxin microcystin were all …

Prothonotary Warbler Nestling Diet And Growth In Response To Variation In Aquatic And Terrestrial Food Availability, Jenna C. Dodson

Theses and Dissertations

Food supply has been suggested as the main determinant of reproductive success in birds. Riparian species can take advantage of seasonal pulses of both terrestrial and aquatic prey, though aquatic resources are often overlooked in studies of diet and reproductive ecology. This study investigates the flux of both aquatic (mayfly) and terrestrial (caterpillar) prey resources and nestling diet of the Prothonotary Warbler throughout the breeding season in two eastern Virginia sites. One site had significantly higher aquatic prey (mayfly) availability. Nestling diet was generally reflective of prey availability, and nestlings grew faster at the site with high aquatic prey availability. …

The Sensory Environments Of Civil War Prisons, Evan A. Kutzler

Theses and Dissertations

The dissertation explores the experiences of four hundred thousand Union and Confederate prisoners during the American Civil War. While much has been written on the overlapping experiences of soldiers, civilians, and slaves, less attention has been paid to those behind masonry walls or wooden stockades. The premise of the dissertation, borrowed from the theory and methodology of sensory history, is that while human sensory physiology changes slowly over time, perception is fluid and varies by time, place, and culture. Drawing from nearly two hundred unpublished manuscripts as well as newspapers, government records, and postwar narratives, this dissertation explores the experiences …

Effects Of The Algal Toxin Microcystin On Fishes In The James River, Virginia, Maxwell D. Haase

Theses and Dissertations

With the global rise in frequency of harmful algal blooms in estuarine environments comes an increase in prevalence of toxic metabolites, such as microcystin (MC), that some of the cyanobacteria involved will produce. At high concentrations, MC may accumulate in consumer tissues and have deleterious effects on organisms; however impacts of the toxin on aquatic living resources at ecologically relevant concentrations have not been widely documented. We analyzed the effects of MC on juveniles of five fish species from the James River, Virginia to determine if MC has the potential to impede growth. Using three separate experimental approaches, it was …

Soundscape Evaluation On Mississippi State University Campus, Yalcin Yildirim

Theses and Dissertations

The term soundscape, used for the first time at the end of 1970s, refers to the sum of the sounds that can be heard and perceived by people in a specific environment. The concept of soundscape has recently received attention in planning and design disciplines. Recent studies on soundscape have shown that the acoustic environment plays an important role for the comfort of site users. Hence, this research investigates how objective measurement of soundscape might be different from subjective perceptions of users in the Mississippi State University Campus as a public open space due to demographic and climatic variations. The …

An Investigation Of Geochemical Evidence For Three Paleo-Environments, John Paul Jones

Theses and Dissertations

Three paleo-environments were studied. The first project concerned the Manson Impact and the effect of the Black Hills on the resulting fall-out from this asteroid strike. Samples of the Crow Creek Member were taken east of the Black Hills in Nebraska and South Dakota and samples from the Red Bird Member were taken from the west, in Wyoming. These samples were examined for chemical weathering, soot, shocked quartz, and fossils. The Crow Creek samples had shocked quartz (indicative of an impact), severe chemical weathering, soot, and evidence of tsunamis. There were few calcareous fossils. The Red Bird showed no signs …

Identifying Adopters Of Best Management Practices Within Mississippi Beef Producers And The Reasons For Non-Adoption, M Scott Cagle

Theses and Dissertations

The goal of the Mississippi State University Extension Service (MSU-ES) is to improve the quality of life for all Mississippians. One specific group that agricultural change agents work with at the county level is beef producers. Grazing lands have received much attention over the last few years regarding environmental concerns and Best Management Practices (BMPs) for beef cattle operations. The adoption of these practices was voluntary during the time this study was conducted, however; adoption was highly encouraged by the MSU-ES and the Natural Resources Conservation Service (NRCS). By knowing the level of adoption of BMPs that Mississippi beef producers …

Forest Net Primary Production Resistance Across A Gradient Of Moderate Disturbance, Ellen Goodrich-Stuart

Theses and Dissertations

The global carbon (C) balance is vulnerable to disturbances that alter terrestrial C uptake and loss. Moderate disturbances that kill or defoliate only a subset of canopy trees such as insect defoliation, drought, and age-related senescence are increasing in extent and frequency; yet, little is known about the effect of moderate disturbance on forest production and the mechanisms sustaining or supporting the recovery of the C cycle across a range of moderate disturbance severities. We used a broad plot-scale gradient of upper canopy tree mortality within a large manipulation of forest disturbance to: 1) quantify how aboveground wood net primary …

Integrating Gis And Hydrology For Flood Risk Analysis, Anas B. Rabie

Theses and Dissertations

Spatial analysis using GIS was evaluated for its ability to predict the potential hazard of a flood event in the Illinois River region in the State of Illinois. The data employed in the analysis are available to the public from trusted organizations such as Illinois State Geological Survey (ISGS), and the US Geological Survey (USGS). The purposes of this study are to 1) examine the applicability of GIS spatial analysis to determine flood inundation risk, and 2) to determine how to do so with the least amount of data possible, while still producing an accurate flood inundation risk map. This …

The Occurrence And Consequences Of Conspecific Brood Parasitism In The Prothonotary Warbler (Protonotaria Citrea), Anna Tucker

Theses and Dissertations

Brood parasites avoid costs associated with raising young by adding eggs to another individual’s clutch and providing no parental care. When conspecific brood parasitism occurs in species with high parental investment, we expect hosts to suffer costs for raising an enlarged brood. Here I describe conspecific brood parasitism (CBP) in the prothonotary warbler using maternal exclusion analyses of 333 family groups. I found that 23.4% of clutches contained at least one offspring that was not matched to the social mother and determined that parasitism seems to be an opportunistic tactic. Hosts had lower average annual reproductive success than non-hosts, but …

A Maoli-Based Art Education: Ku'u Mau Kuamo'o 'Ōlelo, Raquel Malia Andrus

Theses and Dissertations

Leaders in K-12 education in Hawai'i are increasingly advocating for and utilizing the culture and knowledge of the kānaka Maoli, the native people of these islands, as a context for learning in a variety of curricular disciplines and approaches (Benham & Heck, 1998; Kani'iaupuni, Ledward & Jensen, 2010; Kana'iaupuni & Malone, 2006; Kahakalau, 2004; Meyer, 2004). To expand upon this trend, this thesis uses a combination of autoethnographic and critical indigenous methodologies to present a personal narrative that looks specifically at approaching art education from a Maoli perspective. Through extensive participant/observer reflections, two place-based and culture-based art education experiences are …

Characterizing Wetland Hydrology, Chemistry, And Soils For An Endemic Crayfish, The Piedmont Blue Burrower, Jess H. Gilmer Ii

Theses and Dissertations

Anthropogenic alteration of Earth's ecosystems has pushed global biodiversity into a state of crisis. Freshwater species have been particularly vulnerable, with crayfish ranking as the second most imperiled taxonomic group in North America. Primary burrowers represent only 15% of crayfish species in North America; however, they constitute 32% of imperiled crayfish. Despite their conservation importance, little is known about the ecology of burrowing crayfish. To advance our knowledge about the habitat characteristics of burrowing crayfish, groundwater hydrology, water chemistry, and soil properties were assessed to determine their importance for the state-listed endangered, primary burrower Cambarns harti. Groundwater hydrology and …

Evaluation Of Cmip5 Simulated Clouds And Toa Radiation Budgets Using Nasa Satellite Observations, Erica Kay Dolinar

Theses and Dissertations

A large degree of uncertainty in global climate models (GCMs) can be attributed to the representation of clouds and how they interact with incoming solar and outgoing longwave (Earth emitted) radiation. In this study, the simulated total cloud fraction (CF), cloud water path (CWP), top-of-atmosphere (TOA) radiation budgets and cloud radiative forcings (CRFs) from 28 CMIP5 AMIP models are evaluated and compared to multiple satellite observations from CERES, MODIS, ISCCP, CloudSat, and CALIPSO. The multimodel ensemble mean CF (58.6 %) is, on global average, under estimated by nearly 7 % compared to CERES-MODIS (CM) and ISCCP results, with an even …

Historical Tidal Forest Composition And Contemporary Woody Recruitment Following Dam Removal From A Mid-Atlantic Coastal Plain Tidal Freshwater Wetland, Richard E. Ward Jr.

Theses and Dissertations

Tidal freshwater forest restoration after dam removal has been unexplored to date. This study elucidated pre-dam forest composition, as well as post-dam edaphic and microtopographical attributes and woody species recruiting along a narrow ecotone of a 29.3-ha tidal freshwater wetland. The ≈65-year-old historical forest (15 species, 200 stems ha-1) and ≈7-year-old contemporary forest (40 species and 11,009 stems ha-) community dominants were dissimilar (Fraxinus spp. vs. Liquidambar styraciflua, respectively). Pre-dam environmental conditions were unknown. Post-dam edaphic water content, organic matter, redox potential and microtopography differed significantly across tidal sites but were less variable in non-tidal sites. Shifts in the contemporary …

"Mining" For A Reference Condition In Southern West Virginia Streams, Matthew Rouch

Theses and Dissertations

Quarterly samples were used to estimate assemblage-level (all species combined) fish production within three minimally-impacted, southern West Virginia streams. The total annual fish production estimate was highest in Slaunch Fork (37.52 kg∙ha^-1∙y^-1), a tributary of the Tug Fork River, and lowest in Cabin Creek (10.59 kg∙ha^-1∙y^-1), a Guyandotte River tributary. Creek Chub Semotilus atromaculatus, Mottled Sculpin Cottus bairdii and Blacknose Dace Rhinicthys atratulus were the most abundant species among sites, accounting for >90% of all sampled individuals. Reference condition criteria were also selected and metrics calculated for each of the three …

Global Assessment Of Radiocarbon Isotopic Analysis For Particulate And Dissolved Organic Carbon In Riverine Systems, Ashley Tucker

Theses and Dissertations

Rivers are a significant source of particulate and dissolved organic carbon (POC, DOC) into inland waters and coastal systems and provide a fundamental linkage between the terrestrial, oceanic, and atmospheric carbon reservoirs. Recent studies have examined the relationship between the quantity and form (POC vs. DOC) of carbon delivered to the aquatic system; however, little is known about the age of POC and DOC exported and how the radiocarbon age may vary with latitude, topographic gradient, vegetation, and land use. I provide the first global synthesis of published radiocarbon values of POC and DOC (∆14C). Inclusion of DOC and POC …

Development Of Mathematical Model For Abiotic Stresses And Cotton Fiber Quality, Suresh Bajirao Lokhande

Theses and Dissertations

Abiotic stresses cause extensive losses to agriculture production worldwide. Cotton (Gossypium hirsutum L.) is an important fiber crop grown widely in subtropical region where temperature, water and nutrients are the common factors limiting crop production. Such losses could be more severe in the future climate as intensity and frequency of those stresses are projected to increase. The overall goal of this study was to evaluate effects of abiotic stresses on cotton reproductive performance and develop functional algorithms for fiber properties in response to different stress factors. Three experiments were conducted to evaluate the effects of temperature, water, and nitrogen in …

Importance Of Placement Depth In Evaluating Soil Nitrogen, Phosphorus, And Sulfur Using Ion Exchange Resin Capsules In Semi-Arid, Low Fertility Soils, Rachel Lynn Buck

Theses and Dissertations

Ion exchange resin capsules provide a possible alternative to conventional soil testing procedures. Previous studies with semi-arid, low fertility soils observed poor relationships with poorly mobile nutrients such as phosphorus (P). We propose that placement depth may improve those relationships. Our objective was to (1) determine if placement depth could improve resin capsule estimation of the bioavailability of nitrogen (N), P, and sulfur (S) and (2) to determine if resin capsules can effectively estimate S availability in semi-arid, low fertility soils. Field sites were established in Rush and Skull Valleys, Utah on loam and sandy loam soils, respectively. Fertilizer was …

Physiological Mechanisms Of Shrub Encroachment: Linking Enhanced Hydraulic Capacity To Efficient Light Capture And Processing, Sheri Shiflett

Theses and Dissertations

Woody plant expansion has been documented for decades in many different ecosystems, often due to anthropogenic disturbances to the environment and yielding vast changes in ecosystem functioning. While causes and consequences of woody expansion have been well documented, few studies have investigated functional traits of woody species that promote rapid expansion in range. My objective was to determine if hydraulic efficiency confers enhanced photosynthetic efficiency so that functional traits representing light and water use may be possible mechanisms facilitating woody encroachment into grasslands and forest understories. I quantified leaf-level light environment, photosynthetic activity, and hydraulic characteristics of three sympatric broadleaf …

Communication: The Lost Art, Mary Zenyuk

Theses and Dissertations

The purpose of this study was to determine if technology, specifically text messaging, has an affect on young adult's face-to-face communication. Technology is improving on a daily basis. This continuous evolution and advancement in technology has paved the way for numerous methods of communication such as texting and social media. Not only has the methods of communication increased, so has the access to these methods become unlimited. This study is important to analyze how individuals are adapting their communication habits to conform with changing technology. A survey was developed and consisted of questions such as the student's age, major, preferred …

Reproduction And Functional Response Of Cornus Florida Across An Urban Landscape Gradient, Angela Redwine

Theses and Dissertations

Urbanization greatly alters plant and pollinator communities and can affect pollinator movement and subsequent gene flow. Plants persisting in urban areas must adjust to local environmental conditions often different from those in which they naturally evolved, and cultivation techniques for landscaping species have developed traits suitable for existence in urban habitats. Cultivated varieties and native conspecifics often exist in geographic proximity, and if pollinator movement is not blocked by urban structural components, functional differences may negatively impact spatially proximate native populations. I used spatial analysis of successful pollination of Cornus florida to estimate how pollinator movement is affected by urban …

Reforestation Of Red Spruce (Picea Rubens) On The Cheat Mountain Range, West Virginia, Justin Madron

Theses and Dissertations

The (Plethodon nettingi) Cheat Mountain Salamander is a rare and endangered species that relies heavily on (Picea rubens) Red Spruce for habitat. P. rubens communities on the Cheat Mountain range in West Virginia have been disturbed by fires and logging, and regeneration of P. rubens stands are central to the survival of the P. netting. A supervised and unsupervised landscape classification of three Landsat images over the past 26 years was conducted to analyze change in P. rubens communities on Cheat Mountain Range. Change detection results revealed that from 1986-2012 a 52% growth increase of P. rubens stands, 18% loss, …

Estimation Of Aerosolized Antibiotic Resistant Bacteria Concentrations From Wastewater Treatment Facilities Using Spatially-Based Dispersion Modeling, Renee Nichole Dickman

Theses and Dissertations

Pathogenic bacteria can develop resistance to antibiotics to which they were previously sensitive, resulting in increased morbidity and mortality worldwide [1]. The increase in drug resistance in bacteria is an emerging public health concern. The activated sludge tanks of wastewater treatment plants are known sources of antibiotic resistant bacteria. These resistant bacteria can become aerosolized and disperse downwind. Using previously sampled aerosol concentrations and meteorological data, a Gaussian dispersion model was developed to estimate the concentration downwind from a selected wastewater treatment facility. The emission rate was calculated to be 7,941 CFU/m²/sec ± 2,149 CFU/m²/sec. This value was used in …

Climate Change Effects On Vibrio Bacteria In The Winyah Bay Estuary And The Projected Spread Of Vibrio Under Future Climatic Scenarios., Reem Deeb

Theses and Dissertations

While there are several studies on the distribution ofVibrio vulnificusandVibrio parahaemolyticusin estuarine waters around the world, there is little information on the distribution of both organisms in South Carolina waters. Monthly sampling of surface and bottom water from 9 sites in Winyah Bay was conducted over the period April-October 2012. Both organisms were enumerated on CHROMagarVibriomedia. TheVibriocounts obtained were mainly less than 20 Colony Forming Units (CFU)/ml which is typical for what was found elsewhere along the coast of the Carolinas. TheVibrio vulnificuscounts were the highest when salinity ranged between 5 ppt and 20 ppt.Vibrio parahaemolyticusdid not show a clear …

A Geographic Modeling Framework For Assessing Critical Infrastructure Vulnerability: Energy Infrastructure Case Study, Leanne Sulewski

Theses and Dissertations

Vulnerability of critical infrastructure systems is of the utmost importance to a nation's national security interests, especially the electric grid. Despite the importance of these systems, disruptions continue to occur at an alarming rate, thus indicating that there is a fundamental flaw in the way critical infrastructure systems are analyzed for vulnerability.

Critical infrastructure systems are typically analyzed using mathematical approaches such as graph theory, which strip systems of their important geographic information, and only look at their connections to each other. While these relationships and metrics provide useful information, they cannot provide the entire picture. As such, this research …

Environmental Footprints Of Violent Conflict, Swapna Pathak

Theses and Dissertations

The effects of militarized conflict pervade countless aspects of society, yet scholars have focussed very little attention on the consequences of conflict. My dissertation assesses the cost of war by examining the relationship between violent conflict and the environment. I argue that the effect of conflict on the environment is an im- portant consequence of war that is often overlooked in favor of other repercussions such as economy and health that are more politically expedient . I study this effect in the light of components of national environmental capacity and hypothesize that conflicts result in short-term and long-term impact on …

The Atlantic Bluefin Tuna: A Public Policy Approach To Saving An Iconic Species, Timothy Patrick O'Brien

Theses and Dissertations

The Atlantic Bluefin Tuna (Thunnus thynnus) is perhaps the most magnificent and most marvelous nomadic wild animal living in the world. It lives in the deep blue waters of the Atlantic Ocean and is one of the largest of the world’s fin fish and the largest of the 48 other species of tuna (Kuhn, 1996). It is a species that seems to have been designed and sculpted by an artist—sleek, smooth, and beautiful—instead of having been a product of an evolutionary process. Today, the existence and future of the Atlantic Bluefin Tuna is in question because of the constant overexploitation …

Life History Analysis Of James River Atlantic Sturgeon (Acipenser Oxyrinchus Oxyrinchus) With Implications For Management And Recovery Of The Species, Matthew Balazik

Theses and Dissertations

Sturgeon species (family Acipenseridae) are threatened globally due to habitat destruction, pollution, and overfishing. The Atlantic sturgeon Acipenser oxyrinchus oxyrinchus was listed as a federally endangered species in 2012. Atlantic sturgeon have a complex life history that utilizes a wide range of habitats. Timing of life history varies in different areas requiring each population to be studied. Very little work has been published on Atlantic sturgeon reproduction in the James River, Virginia. To aid the recovery of James River Atlantic sturgeon, aspects of life history need to be addressed. To increase understanding of Atlantic sturgeon life history a length at …

The Effects Of River Sediment, Endosulfan, And Moderate Hypoxia On Blue Crabs (Callinectes Sapidus) From The Tidal, Freshwater James River, Laura Williams

Theses and Dissertations

Juvenile male blue crabs move into the tidal, freshwater James River during warmer months to feed and grow by undergoing molting. In crustaceans, growth and molting are hormonally controlled. The physiological effects of a multiple-stressor environment are determined by comparing the blue crab’s oxygen uptake after exposure to pure sand, James River sediment, or endosulfan-spiked sand. The effect of multiple stressors on molting is measured by the activity level of N-acetyl-ß-glucosaminidase (NAG), an enzyme in epidermal tissue important to molting. The oxygen uptake was decreased by exposure to James River sediment but not for exposure to endosulfan for seven days. …

In-Text And Out-Of-Text Engagement: Interactional Features In Students' Academic Writing And Academic Engagement, Florette Press

Theses and Dissertations

While student engagement theory recognizes writing as an engaging activity, there have been few studies that explore the levels of engagement within college students' academic writing. Analyses of in-text interactions between writers and their imagined reader(s) can uncover writers' attitudes about themselves as writers and as participants in the academic community. This study looked specifically at students' in-text interaction in the context of overall student engagement. Making a connection between interactional features in writing and overall student engagement provided a new perspective by which professors and administrators can evaluate students' academic integration. This study combined text analysis and interviews with …