Physical Sciences and Mathematics Commons^™

On The Quantification Of Complexity And Diversity From Phenotypes To Ecosystems, Zachary Harrison Marion

Doctoral Dissertations

A cornerstone of ecology and evolution is comparing and explaining the complexity of natural systems, be they genomes, phenotypes, communities, or entire ecosystems. These comparisons and explanations then beget questions about how complexity should be quantified in theory and estimated in practice. Here I embrace diversity partitioning using Hill or effective numbers to move the empirical side of the field regarding the quantification of biological complexity.

First, at the level of phenotypes, I show that traditional multivariate analyses ignore individual complexity and provide relatively abstract representations of variation among individuals. I then suggest using well-known diversity indices from community ecology …

Understanding Stakeholder Attitudes And Involvement In Habitat Conservation Plans And The Endangered Species Act, Kyle Andrew Rodgers

Masters Theses

The Endangered Species Act (ESA), established in 1973, was a landmark piece of environmental legislation and remains the standard for endangered species conservation. Implementation of the ESA has often been framed as pitting economic development against species conservation, inciting passions for and against endangered species conservation. The strength of opposing public opinions is highlighted by high-profile controversies such as those around the snail darter, northern spotted owl and the greater sage grouse. In an attempt to reduce conflict, the US Fish and Wildlife Service (USFWS) increasingly seeks to utilize collaborative, stakeholder-based processes that address stakeholder interests, attitudes, and values.

In …

Metabolomics Approaches To Decipher The Antibacterial Mechanisms Of Yerba Mate (Ilex Paraguariensis) Against Staphylococcus Aureus And Salmonella Enterica Serovar Typhimurium, Caroline Sue Rempe

Doctoral Dissertations

The increasing prevalence of drug-resistant pathogens is an urgent problem that requires novel methods of bacterial control. Plant extracts inhibit bacterial pathogens and could contain antibacterial compounds with novel mechanisms of action. Yerba mate, a common South American beverage made from Ilex paraguariensis, has antibiotic activity against a broad range of bacterial pathogens. In this work, an attempt was first made to characterize the antibacterial source of an aqueous yerba mate extract by generating a series of extract fractions, collecting GC-MS and antibacterial activity profiles, and then ranking the hundreds of compounds by their presence in fractions with high antibacterial …

Regional Dynamic Price Relationships Of Distillers Dried Grains In U.S. Feed Markets, Matthew Fulton Johnson

Masters Theses

Distillers dried grains with solubles (DDGS) is now a mainstream substitute in U.S. animal feed rations. DDGS is rich in fat and protein content and serves as a competitive feed source in livestock markets. The objective of this study is to identify dynamic price relationships among DDGS, corn, soybean meal, and livestock outputs in context of specific livestock sectors and their geographic location. Four locations associated with a predominant livestock sector are selected for analysis by measuring density and relative proportion of a livestock sector’s grain consumption at the county level. A vector error correction model is applied to post-mandate …

Testing The Temporal Stability Of The Climate Response Of Tree Species At Norris Dam State Park, Tennessee, U.S.A., Allison Elizabeth Ingram

Masters Theses

Temporal stability of the climate-tree growth relationship means that over time, tree species were responding to a specific climate variable and continue to respond to that variable into the present. The stability of this response is important to test prior to attempting to reconstruct past climate. In this study, I sampled oaks (white oak = Quercus alba L. and chestnut oak = Quercus montana Willd.) and pines (Virginia pine = Pinus virginiana Mill. and shortleaf pine = Pinus echinata Mill.) growing in Norris Dam State Park in eastern Tennessee and tested the temporal stability of these species and their potential …

Microbial Extracellular Enzymes In Marine Sediments: Methods Development And Potential Activities In The Baltic Sea Deep Biosphere, Jenna Marie Schmidt

Masters Theses

The deep biosphere is defined as the subsurface ecosystem in which little energy is available to microorganisms and microorganisms can live for thousands of years. Heterotrophic microbes survive in the deep biosphere even though organic matter is limited and highly recalcitrant in nature. Measuring microbial extracellular enzyme activity provides a potential means to evaluate the rate at which microorganisms are performing carbon remineralization in the energy limited sediment beneath the seafloor. Extracellular enzymes breakdown organic compounds so that the nutrients can move inside the cell and be used for energy. This study explored the role extracellular enzymes play in the …

Anthrax Models Involving Immunology, Epidemiology And Controls, Buddhi Raj Pantha

Doctoral Dissertations

This dissertation is divided in two parts. Chapters 2 and 3 consider the use of optimal control theory in an anthrax epidemiological model. Models consisting system of ordinary differential equations (ODEs) and partial differential differential equations (PDEs) are considered to describe the dynamics of infection spread. Two controls, vaccination and disposal of infected carcasses, are considered and their optimal management strategies are investigated. Chapter 4 consists modeling early host pathogen interaction in an inhalational anthrax infection which consists a system of ODEs that describes early dynamics of bacteria-phagocytic cell interaction associated to an inhalational anthrax infection.

First we consider a …

Biophysical Studies Of Cell Division Protein Localization Mechanisms In Escherichia Coli, Matthew Wayne Bailey

Doctoral Dissertations

How nanometer-scale proteins position accurately within micron-scale bacteria has intrigued both biologists and physicists alike. A critical process requiring precise protein localization is cell division. In most bacteria, cell division starts with the self-assembly of the FtsZ proteins into filaments that form a ring-like structure encircling the cell at its middle, the Z-ring. The Z-ring is a scaffold for additional proteins that synthesize the lateral cell wall which separates the two daughter cells. If division planes are misplaced relative to bacterial chromosomes, also called nucleoids, daughter cells with incomplete genetic material can be produced. In Escherichia coli, research carried out …

Opportunities In Sustainability: Maize Seeders For The Developing World And Alternative Fertilizers In The United States, Rebecca Mattingly Harman

Masters Theses

Sustainable agricultural systems are needed for both large and small-scale farmers the world over. Central to the sustainability of these systems is the availability of cheap and effective seeders for smallholder farmers and effective utilization of less energy intensive nitrogen sources. In the first two chapters, this thesis considers maize seeders for smallholder use in a Conservation Agriculture system. To sustain the smallholder sector, soil fertility and soil erosion must be addressed and a Conservation Agriculture model seeks to improve soil conditions in agriculture. The technologies available to smallholder farmers, though, need to be tested in a no-till system before …

Impacts Of Biofumigation And Anaerobic Soil Disinfestation On Strawberry Production, Jennifer Renee’ Wheeler

Masters Theses

Due to the phase-out of methyl bromide, there is a need for alternative, nonchemical fumigation treatments in strawberry production. Anaerobic soil disinfestation and biofumigation are two non-chemical methods for controlling soilborne plant pathogens of strawberry. This study was designed to observe strawberry fruit nutrition and soil volatiles of a strawberry field being treated with biofumigation treatments, anaerobic soil disinfestation treatments, and a combination of the two alternative methods. A trial was conducted with 11 pre-plant soil-incorporated treatments arranged in a randomized complete block design with 6 rows (blocks). Biofumigation treatments consisted of deactivated mustard meal, deoiled mustard meal, mustard pellets, …

Modeling Feral Hogs In Great Smoky Mountains National Park, Benjamin Anthony Levy

Doctoral Dissertations

Feral Hogs (Sus scrofa) are an invasive species that have occupied the Great Smoky Mountains National Park since the early 1900s. Recent studies have revitalized interest in the pest and have produced useful data. The Park has kept detailed records on mast abundance as well as every removal since 1980 including geographic location and disease sampling. Data obtained via Lidar includes both overstory as well as understory vegetation information. In this dissertation, three models were created and analyzed using the detailed data on vegetation, mast, and harvest history. The first model is discrete in time and space and …