Physical Sciences and Mathematics Commons^™

Analytical Considerations And Methods For Comprehensive Analysis Of Bacterial Phospholipidomics Using Hilic-Ms/Ms, David Thomas Reeves

Doctoral Dissertations

Omics technologies have rapidly evolved over the last half century through vast improvements in efficient extraction methodologies, advances in instrumentation for data collection, and a wide assortment of informatics tools to help deconvolute sample data sets. However, there are still untapped pools of molecules that warrant further analytical attention. As the frontline defense of the cell against exterior influences, the phospholipid membrane is key in structure, defense, and signaling, but current omics studies are only just now catching up to the potential hidden within cellular lipid profiles. Examination of shifts in phospholipid speciation and character could provide researchers with a …

Influence Of Physical Variability Of Highly Weathered Sedimentary Rock On Nitrate In Area 3 Of The Enigma Field Research Site At Y-12, Erin Kelly

Masters Theses

Uranium processing and waste storage in unlined waste ponds leached contaminants into the groundwater at Y-12, Oak Ridge, Tennessee, from the 1950s to 1980s. Groundwater wells near the S-3 ponds have had the highest nitrate concentrations of groundwater anywhere in the world (>10,000 mg/L). For reference, the maximum contaminant level for nitrate in drinking water set by the U.S. Environmental Protection Agency is 10 mg/L. Since 2012, the ENIGMA (Ecosystems and Networks Integrated with Genes and Molecular Assemblies) group has been characterizing, monitoring, and conducting field experiments to understand the interactions between contaminants, microbes, and the subsurface. The goals …

Birds And Bioenergy: A Modeling Framework For Managed Landscapes At Multiple Spatial Scales, Jasmine Asha Kreig

Doctoral Dissertations

This dissertation examines the design and management of bioenergy landscapes at multiple spatial scales given numerous objectives. Objectives include biodiversity outcomes, biomass feedstock yields, and economic value.

Our study examined biodiversity metrics for 25 avian species in Iowa, including subsets of these species related to ecosystem services. We used our species distribution model (SDM) framework to determine the importance of predictors related to switchgrass production on species richness. We found that distance to water, mean diurnal temperature range, and herbicide application rate were the three most important predictors of biodiversity overall. We found that 76% of species responded positively to …

Investigation Of Interactions Between 1,3 Dialkyl Imidazolium Ionic Liquids And Lignocellulosic Polymers, Aparna Annamraju

Doctoral Dissertations

Lignocellulosic biomass is a potential energy source for fuels, chemicals and materials production in a sustainable manner. A network of covalent and non-covalent bonds between the three main polymers of biomass, i.e., cellulose, hemicellulose and lignin, results in a compact structure that is resistant to chemical and biological attacks and therefore challenging for the efficient utilization of lignocellulosic biomass. Ionic liquids (ILs) have been reported to disrupt the bonds between these polymers and dissolve biomass at temperatures below 100 ˚C. Research through the years has shown that biomass pretreatment with IL brings out the selective dissolution of biomass polymers and …

Synthetic Heterosynaptic Plasticity Enhances The Versatility Of Memristive Systems Emulating Bio-Synapse Structure And Function, William T. Mcclintic

Doctoral Dissertations

Memristive systems occur in nature and are hallmarked via pinched hysteresis, the difference in the forward and reverse pathways for a given phenomenon. For example, neurons of the human brain are composed of synapses which apply the properties of memristance for neuronal communication, learning, and memory consolidation. Modern technology has much to gain from the characteristics of memristive systems, including lower power operation, on-chip memory, and bio-inspired computing. What is more, a relationship between memristive systems and synaptic plasticity exists and can be investigated focusing on homosynaptic and heterosynaptic plasticity. Where homosynaptic plasticity applies to interactions between neurons at a …

Association Between Stream Impairment By Mercury And Superfund Sites In The Conterminous Usa, Karessa L. Manning

Masters Theses

Mercury is a natural element that can cause harm to the brain, heart, kidneys, lungs, and immune system, especially to fetuses developing in the womb. Many natural and anthropogenic factors contribute to mercury in the environment, such as geologic deposits, landfills, gold and silver mining operations, cement production, and atmospheric deposition. Mercury has been identified as a contaminant of concern at many National Priority List (NPL) sites, however, studies on contamination at NPL sites are often only conducted on a local level. This study was to analyze the potential connection between mercury-contaminated NPL sites and the presence of mercury impaired …

Data Driven Models Of Hemlock Woolly Adelgid Impacts And Biological Control, Hannah M. Thompson

Doctoral Dissertations

We present two models of the Adelges tsugae, the hemlock woolly adelgid, an invasive insect pest of Tsuga canadensis, eastern hemlock, in the eastern United States. An A. tsugae infestation often results in the death of T. canadensis within years, and has caused significant changes to hemlock forests. We construct two models composed of systems of ordinary differential equations with time dependent parameters to represent seasonality. The first model captures the coupled cycles in T. canadensis health and A. tsugae density. We use field data from Virginia to develop the model and to perform parameter estimation. The mechanisms …