Physical Sciences and Mathematics Commons^™

Thermochemistry Of Amino Acids And Constrained Diamines, Erica Jane Tullo

Dissertations, Theses, and Masters Projects

The gas-phase proton affinities of several highly basic amino acids and diamines were determined using the extended kinetic method in an ESI-quadrupole ion trap instrument. The non-protein amino acid L-canavanine is structurally related to L-arginine with an oxygen substituted for the terminal methylene group of L-arginine and is highly toxic to humans. The proton affinity of L-arginine, a protein amino acid, was determined to be 1036 kJ mol -1, whereas the proton affinity of L-canavanine was determined to be 1005 kJ mol-1. Thus, substitution of an oxyguanidino group for the guanidine group in L-arginine results in a large decrease in …

Luminescent Nitrogen And Sulfure Adducts Of Cui Disubstituted Piperazine Complexes, Jason P. Safko

Dissertations, Theses, and Masters Projects

No abstract provided.

Distribution And Feeding Ecology Of Bathylagus Euryops (Teleostei: Microstomatidae) Along The Northern Mid-Atlantic Ridge From Iceland To The Azores, Christopher J. Sweetman

Dissertations, Theses, and Masters Projects

The northern Mid-Atlantic Ridge, from Iceland to the Azores (MAR), ranges in depth from 800 – 4500 m and extends over an area of 3.7 million km2. Recent evidence from MAR-ECO, a Census of Marine Life field project, reported increased abundance and biomass of deep-pelagic fishes below 1000 m on the MAR. Among the fishes sampled, Bathylagus euryops was found to be the biomass-dominant species and ranked third in total abundance. In this thesis, we characterize the distribution and feeding ecology of B. euryops as a function of physical, biological, and life history parameters along a mid-ocean ridge system. Multiple …

Movements, Growth, And Mortality Of Chesapeake Bay Summer Flounder Based On Multiple Tagging Technologies, Mark J. Henderson

Dissertations, Theses, and Masters Projects

The research projects presented in this dissertation used multiple tagging technologies to examine the movements, growth, and mortality rates of summer flounder tagged and released in Chesapeake Bay. In the first two chapters, I used acoustic, archival, and conventional tags to examine the behavior of summer flounder on different spatial scales. Investigating the movement behavior of individuals on different scales is an important step towards understanding how large-scale distributions of a population are established. Based on the observed behaviors of summer flounder, I hypothesize that the movements of these fish are primarily related to foraging behavior while they are resident …

Developing An Unstructured Grid, Coupled Storm Surge, Wind Wave And Inundation Model For Super-Regional Applications, Yi-Cheng Teng

Dissertations, Theses, and Masters Projects

During extreme weather conditions such as hurricanes and nor'easters, both the currents and wind waves generated by the atmospheric forces are important. Although they may act and dominate on different temporal and spatial scales, their interactions and combined effects are without doubt significant. In this dissertation, a major effort has been made to couple an unstructured grid circulation model SELFE (semi-implicit, Eulerian-Lagrangian finite element model) and the WWM II (Wind Wave model II). Moreover, this new coupled model system can be executed in a parallel computational environment. After the coupled model was successfully built, the model was verified with ideal …

Measurement Of Single And Double Spin Asymmetries In P(E, E' Pi(+/-,0))X Semi-Inclusive Deep-Inelastic Scattering, Sucheta Shrikant Jawalkar

Dissertations, Theses, and Masters Projects

Measurements in the late 1980s at CERN revealed that quark spins account for a small fraction of the proton's spin. This so-called spin crisis spurred a number of new experiments to identify the proton's silent spin contributors, namely, the spin of the gluons, which hold the quarks together, and the orbital angular momentum of both quarks and gluons. One such experiment was eg1-dvcs at the Thomas Jefferson National Accelerator Facility in Newport News, Va., which ran in 2009 and collected approximately 19 billion electron triggers for hydrogen. I will present new measurements of the single and double-spin asymmetries ALU, AUL …

Dark Matter In The Heavens And At Colliders: Models And Constraints, Reinard Primulando

Dissertations, Theses, and Masters Projects

In this dissertation, we investigate various aspects of dark matter detection and model building. Motivated by the cosmic ray positron excess observed by PAMELA, we construct models of decaying dark matter to explain the excess. Specifically we present an explicit, TeV-scale model of decaying dark matter in which the approximate stability of the dark matter candidate is a consequence of a global symmetry that is broken only by instanton-induced operators generated by a non-Abelian dark gauge group. Alternatively, the decaying operator can arise as a Planck suppressed correction in a model with an Abelian discrete symmetry and vector-like states at …

Towards Confident Body Sensor Networking, Zhen Ren

Dissertations, Theses, and Masters Projects

With the recent technology advances of wireless communication and lightweight low-power sensors, Body Sensor Network (BSN) is made possible. More and more researchers are interested in developing numerous novel BSN applications, such as remote health/fitness monitoring, military and sport training, interactive gaming, personal information sharing, and secure authentication. Despite the unstable wireless communication, various confidence requirements are placed on the BSN networking service. This thesis aims to provide Quality of Service (QoS) solutions for BSN communication, in order to achieve the required confidence goals.;We develop communication quality solutions to satisfy confidence requirements from both the communication and application levels, in …

Seed Burial In The Seagrass Zostera Marina: The Role Of Infauna, Natalia J. Blackburn

Dissertations, Theses, and Masters Projects

In terrestrial systems, seed burial is widely recognized as a vital process that influences small- and large-scale plant population patterns. Despite its demonstrated importance in terrestrial literature, very little is known about seed burial in seagrasses. Zostera marina is a perennial seagrass found in northern temperate oceans worldwide, and is the dominant seagrass found in the Chesapeake Bay. In terrestrial systems, seed burial is frequently mediated by soil-dwelling invertebrates. The goal of this work was to determine the role that benthic infauna play in the burial of Z. marina seeds by addressing the following questions: 1. Are seeds on sediments …

Unprecedented Restoration Of A Native Oyster Metapopulation, David M. Schulte

Dissertations, Theses, and Masters Projects

No abstract provided.

A Community-Based Participatory Assessment Of Fish Consumption And Dietary Mercury Exposure Along The Lower James River, Virginia Usa, Erica Lynnette Holloman

Dissertations, Theses, and Masters Projects

The use of community-based participatory research (CBPR) methods to conduct environmental exposure assessments provides valuable insight about disparities in fish consumption and contaminant exposure. Ninety-five community-specific fish consumption surveys were administered to low-income African American women (ages 16--49) residing in the Southeast community of Newport News, Virginia, USA, in 2008. The mean fish consumption rate for the women surveyed was 147.8 g/day (95% CI: 117.6-185.8), a rate substantially higher than the mean fish consumption rate reported for U.S. women (1.8 g/day 95% CI: 1.51-2.04). Through collaborative partnerships established between current researchers and The Moton Community House (a local community center), …

Quantifying Watershed Loads To A Low Relief, Coastal Plain Estuary, The New River Estuary, N.C, Brittani J. Koroknay

Dissertations, Theses, and Masters Projects

Watershed modeling is an important tool for quantifying the inputs of fresh water, sediments, and nutrients into receiving estuaries and potential changes in those loads under scenarios including changes in land use and climate. There are a variety of existing watershed loading models available, from simple to complex, but a spectrum of these models have yet to be applied and compared in a low relief, coastal plain setting. This project has been conducted as part of the Defense Coastal/Estuarine Research Program (DCERP), which has focused on the impact of Marine Corp Base Camp Lejeune (MCBCL) and activities in the surrounding …

Interannual And Regional Differences In Krill And Fish Prey Quality Along The Western Antarctic Peninsula, Kate E. Ruck

Dissertations, Theses, and Masters Projects

Polar zooplankton and fish safeguard against the seasonality of food availability by using the summer months to build large reserves of lipids, which in turn are utilized to meet the metabolic demands of apex predators such as penguins, seals, and whales. A warming trend in the northern part of the western Antarctic Peninsula (WAP) has led to a decrease in perennial and summer sea ice, an increase in heat content over the shelf, and lower phytoplankton biomass, which could affect prey quality. We compared prey quality, including elemental (C, N) content and ratios, total, neutral, and polar lipid content, and …

Shedding Light On The Estuarine Coastal Filter: The Relative Importance Of Benthic Macroalgae In Shallow Photic Systems, Johnathan Daniel Maxey

Dissertations, Theses, and Masters Projects

No abstract provided.

Habitat Utilization And Trophic Interactions By Fauna In A Shallow Estuary: Comparisons Between Clam Aquaculture And Natural Sites, Lara Gates Kling

Dissertations, Theses, and Masters Projects

Aquaculture of the hard clam, Mercenaria mercenaria, has steadily increased in the United States over the past 25 years. In some areas, including along Virginia’s coast, this industry has grown to such a scale that aquaculture systems now exist as agroecosystems within coastal waters. Several features of these aquaculture systems, such as high clam densities and protective mesh netting, may modify the availability of habitat, food, and nutrients and may be expected to affect benthic and nektonic community structure. Few studies, however, have evaluated these effects. We conducted seasonal (May – September) sampling in a tidal tributary of Chesapeake Bay …

Evaluating Persistent Organic Pollutants (Pops) And Mercury In The West Antarctic Peninsula (Wap) Food Web, With A Focus On Antarctic Fur Seals (Arctocephalus Gazella), Emily K. Brault

Dissertations, Theses, and Masters Projects

No abstract provided.

Patterns Of Population Structure And Historical Dispersal In Squaloid Sharks: A Species-Level Approach Using Molecular Markers, Ana Christina Pimenta Verissimo

Dissertations, Theses, and Masters Projects

Squaloids (Order Squaliformes) are a highle diverse group of mostly deepwater habitats (> 200 m). Many species are regularly caught in commercial fisheries worldwide but their low productivity and correspondingly low intrinsic rebound potentials make them particularly vulnerable to population depletion and overexploitation. of special concern to fisheries management and conservation efforts are the spiny dogfish Squalus acanthias, the leafscale gulper shark Centrophorus squamosus and the Portuguese dogfish Centroscymnus coelolepis. These taxa have recently been declared overfished in several parts of each species' distribution but management efforts have been made to recover the "stocks" without a good understanding of the …

Life History And Ecology Of The Freshwater Amphipods Gammarus Pseudolimnaeus And Gammarus Fasciatus In Southeastern Virginia, Lindsey L. Postaski

Dissertations, Theses, and Masters Projects

No abstract provided.

Effects Of Nucleophile Strength On Selectivity In Bibr3 Catalyzed Cyclic Ether Construction, Ajara A. Rahman

Dissertations, Theses, and Masters Projects

No abstract provided.

The Role Of Small Carboxylic Acids During Poly(Amide) 11 Hydrolysis, John-Andrew Samuel Hocker

Dissertations, Theses, and Masters Projects

No abstract provided.

The Role Of Benthic Nitrogen Fixation As A Source Of New Nitrogen To The New River Estuary, Nc, Meaghan L. Whitehead

Dissertations, Theses, and Masters Projects

Nitrogen (N) has been shown to limit primary production in many estuarine systems, including the New River Estuary (NRE), NC, a moderately eutrophied system with large areas of photic sediment. The NRE receives major inputs of allochthonous nutrients from agriculture and confined animal feeding operations as well as other sources. Autochthonous sources of N in the NRE include both remineralization and Nfixation. Whereas allochthonous sources are usually most important in winter/spring and during periods of high fresh water discharge, autochthonous sources are likely to become more important in summer. N-fixation, which can be performed by both autotrophic cyanobacteria and heterotrophic …

Poverty Shelf, New Zealand From The Holocene To Present: Stratigraphic Development And Event Layer Preservation In Response To Sediment Supply, Tectonics And Climate, Lila Eve Rose Pierce

Dissertations, Theses, and Masters Projects

The small, high sediment yield Waipaoa River is located on the tectonically active, mountainous Poverty Margin on the east coast of the North Island, New Zealand. In contrast to sedimentary sequences on passive margin shelves, active margins, such as the Poverty Margin, can preserve continuous records of changing geological and environmental conditions at the land-sea interface during rapid sea-level rise. Two subsiding mid-shelf basins on the Poverty Shelf contain thick transgressive sequences which provide a record of evolving river, climate, landscape, and oceanographic conditions since the Last Glacial Maximum (LGM). This dissertation investigates the stratigraphic development of Poverty Shelf, including …

A Case Study In The Effectiveness Of Marine Protected Areas (Mpas): The Islands Of Bonaire And Curacao, Dutch Caribbean, Noelle J. Relles

Dissertations, Theses, and Masters Projects

The islands of Bonaire and Curacao, Dutch Caribbean, were both mapped along their leeward coasts for dominant coral community and other benthic cover in the early 1980s. This mapping effort offers a unique baseline for comparing changes in the benthic community of the two islands since that time, particularly given the marked differences between the two islands. Bonaire is well-protected and completely surrounded by a marine protected area (MPA), which includes two no-diving marine reserves; additionally, Bonaire's population is only around 15,000. In contrast, the island of Curacao is home to 140,000 inhabitants and marine protection is limited, with a …

A Study Of Vertical Patterns And Mechanisms Of Along-Channel Estuarine Circulation, Qubin. Qin

Dissertations, Theses, and Masters Projects

The classical theory of estuarine dynamics has been challenged by a number of recent studies regarding the important contributions of tidal, lateral, and Coriolis effects to the subtidal dynamics at leading order. Although the classical theory excluded these processes, Hansen and Rattray’ ( R65) b subtidal circulation. However, the success of the predictive skill is not well understood. In this thesis, a perturbation approach is introduced to derive a “ ” (GS) of subtidal along-channel velocity profile for estuarine circulation incorporating the effects of tidal and lateral processes, which allows us to evaluate the possible circulation patterns, the underlying mechanisms, …

The Consequences Of Shoreline Development For Near-Shore Communities In Chesapeake Bay, Usa: A Before-After Control-Impact Study, Theresa M. Davenport

Dissertations, Theses, and Masters Projects

Hardened shorelines and their construction introduce stressors to a system by altering near-shore habitats. They can reduce biodiversity and abundance of benthic infauna and marsh-edge nekton and epifauna. In this study, I investigated the impacts of shoreline development on near-shore communities using a temporal and spatial approach, by use of a before-after control-impact (BACI) study design at four sub-estuaries within Chesapeake Bay that represent three different types of shoreline change. The BACI study was used to examine infaunal density, biomass, and diversity for two size classes of infauna (3-mm: larger species and adults, 500-!m: smaller species and juveniles), as well …

Myctophid Feeding Ecology And Carbon Transport Along The Northern Mid-Atlantic Ridge, Jeanna M. Hudson

Dissertations, Theses, and Masters Projects

The Mid-Atlantic Ridge (MAR) is the largest topographic feature in the Atlantic Ocean, yet little is known about the food web structure and trophic ecology of fishes inhabiting mesopelagic waters along the MAR. To better understand the food web structure and to compare the feeding ecology of abundant MAR fishes to those in offridge areas, MAR-ECO, a Mid-Atlantic Ridge ecosystem field project of the Census of Marine Life, sampled the pelagic fauna of the northern MAR (Iceland to the Azores) during June-July, 2004. Samples were collected with two midwater trawls outfitted with multiple opening and closing cod ends to sample …

Relationships Among Fine Sediment Settling And Suspension, Bed Erodibility, And Particle Type In The York River Estuary, Virginia, Kelsey A. Fall

Dissertations, Theses, and Masters Projects

In order to understand the processes controlling the temporal variability in settling velocity (Ws) and bed erodibility (ε), in the middle reaches of the York River estuary, VA, the relationships between the hydrodynamics and particle types were investigated with a near-­‐bed Acoustic Doppler Velocimeter (ADV) and the York River 3-­‐D Hydrodynamic Cohesive Bed Model.

ADV observations of the flow characteristics that occurred over a strong temporal transition period indicated that Ws and ε were characterized by two distinct regimes with contrasting sediment and water column characteristics: (i) a physically-­‐dominated regime (Regime 1) which was a period dominated by flocculated muds …

Transport And Fate Of Sediment On The Waipaoa River Continental Shelf: Implications For The Formation And Reworking Of Flood Deposits, Julia M. Moriarty

Dissertations, Theses, and Masters Projects

As part of a large interdisciplinary study, particulate fluxes in the Waipaoa River sedimentary system in New Zealand have been studied from the terrestrial headlands of the catchment to the oceanic basin over timescales spanning storm events, seasons, and the Holocene. Here, we complement prior efforts by evaluating the formation and reworking of riverine deposits during episodic flood and wave events, and considering their role in accumulation patterns created over longer timescales on the Waipaoa shelf. Using a numerical hydrodynamic and sediment transport model, sediment fluxes and deposition were analyzed from January 2010 through February 2011.

A version of the …

Microzooplankton Community Structure And Grazing Impact Along The Western Antarctic Peninsula, Lori M. Price

Dissertations, Theses, and Masters Projects

Microzooplankton (zooplankton 20 – 200 μm) are an integral part of aquatic food webs as they can be significant grazers of phytoplankton and bacteria, remineralizers of nutrients, and prey for higher trophic levels. The importance of microzooplankton in many pelagic ecosystems has been established, yet compared to larger zooplankton, microzooplankton are understudied in the Southern Ocean. I quantified microzooplankton community composition and grazing rates along the Western Antarctic Peninsula (WAP) as part of the Palmer Antarctica Long-Term Ecological Research project (PAL LTER). This region is experiencing rapid warming, causing declines in sea ice and changes in the marine food web. …

Evaluating The Impact Of Stock Structure Uncertainty In Stock Assessments Of Sailfish In The Atlantic Ocean, Catarina Wor Lima

Dissertations, Theses, and Masters Projects

No abstract provided.