Physical Sciences and Mathematics Commons^™

Investigation Of 89zr-Siderophores As Molecular Imaging Agents For Positron Emission Tomography Imaging Of Bacterial Infections, Nora C. M. Goscinski

Arts & Sciences Electronic Theses and Dissertations

Siderophores are small molecules synthesized by bacteria to harvest Fe³⁺ from their environment. In infection scenarios, their production can increase infection virulence by increasing the ability of bacteria to obtain Fe³⁺ and therefore grow more rapidly. The selective uptake of siderophores in vivo in multi-bacteria environments indicates that this class of molecules has a potential use as selective imaging agents. In this work, DFO-NCS and a library of trihydroxamate siderophores were evaluated as vehicles to deliver ⁸⁹Zr selectively to bacteria for Positron Emission Tomography (PET) imaging of bacterial infections.

Productive work with radiometals involves thorough knowledge of …

Investigating The Complexity Of Impact Crater Ejecta, Michael Raymond Zanetti

Arts & Sciences Electronic Theses and Dissertations

The formation of an impact crater ejecta blanket can be viewed as a form of organized chaos. Material that is ejected from a crater is heavily brecciated, but falls back to the surface along ballistic trajectories, generally preserving an inverted sense of the original stratigraphy. As the ejecta re-impacts the area surrounding the crater it forms a thick blanket of ejected material and reworked target surface that gradually thins away from the crater rim. Within the crater, crater modification processes, such as wall terrace formation and impact melt drainage, transform the crater in expectable ways.

The approach adopted in this …

Manipulating Electron Transfer Reactions From Micro- To Preparative Scale, Matthew Duane Graaf

Arts & Sciences Electronic Theses and Dissertations

The utilization of electron transfer reactions has allowed the transformation of a variety of substrates from polymer surfaces to highly functionalized organic molecules. The intricacies of these electron transfer reactions have been utilized to develop a new platform for building and studying addressable molecular libraries as they interact with biological targets. As a low cost, reusable alternative to other methods of these studying binding interactions, microelectrode arrays are beginning to gain traction with the scientific community as we continually push the limits of their potential. Additionally, the electron transfer techniques used to build the molecular libraries can be expanded to …

Solid-State Nmr Studies Of Carbon Capture And Carbon Mineralization Reactions, Jeremy Moore

Arts & Sciences Electronic Theses and Dissertations

This dissertation presents research on the chemistry of carbon dioxide capture and mineralization which has been accomplished with a variety of solid-state nuclear magnetic resonance (NMR) spectroscopy techniques. Materials used for carbon capture interact with CO2 through different adsorption mechanisms, physisorption and chemisorption. The physisorption systems studied have shown that adsorbed CO2 undergoes a hopping mechanism within the material. The studies of chemisorption systems indicate a mixture of adsorption products forms during the adsorption interaction. Carbon mineralization reactions have been studied to better understand the reactions that can occur at underground carbon sequestrations sites that are used for storing CO2. …

Structural And Functional Analysis Of The Reaction Center Complexes From The Photosynthetic Green Sulfur Bacteria, Guannan He

Arts & Sciences Electronic Theses and Dissertations

The reaction center (RC) complex of the green sulfur bacterium Chlorobaculum tepidum is composed of the Fenna-Matthews-Olson (FMO) antenna protein and the reaction center core (RCC) complex. The RCC complex has four subunits: PscA, PscB, PscC, and PscD. The structure of the intact and functional FMO-RCC complex was studied by chemically cross-linking the purified sample followed by biochemical and spectroscopic analysis. The interaction sites of the cross-linked complex were also studied using LC-MS/MS. A structural model is proposed based on those results. In addition, the RCC complexes were purified, both the PscA-PscC complex from the Chlorobaculum tepidum and the PscA-PscB …

A Molecular Dynamics Study Of The Structure-Dynamics Relationships Of Supercooled Liquids And Glasses, Ryan Joseph Soklaski

Arts & Sciences Electronic Theses and Dissertations

Central to the field of condensed matter physics is a decades old outstanding problem in the study of glasses – namely explaining the extreme slowing of dynamics in a liquid as it is supercooled towards the so-called glass transition. Efforts to universally describe the stretched relaxation processes and heterogeneous dynamics that characteristically develop in supercooled liquids remain divided in both their approaches and successes. Towards this end, a consensus on the role that atomic and molecular structures play in the liquid is even more tenuous. However, mounting material science research efforts have culminated to reveal that the vast diversity of …

Topics In Lattice Gauge Theory And Theoretical Physics, Javad Komijani

Arts & Sciences Electronic Theses and Dissertations

This dissertation contains two completely independent parts.

In Part 1,

I investigate effective field theories and their applications in lattice gauge theory.

Quantum chromodynamics (QCD) as a part of the standard model (SM) describes the physics of quarks and gluons.

There are several numerical and analytical methods to tackle the QCD problems.

Lattice QCD is the dominant numerical method.

Effective field theories,

on the other hand, provide analytic methods to describe the low-energy dynamics of QCD.

To use the effective theories in lattice QCD,

I develop chiral perturbation theory for heavy-light mesons with staggered

quarks---an implementation of fermions on lattice. …

Enhanced Magnetism In Dy And Tb At Extreme Pressure, Jinhyuk Lim

Arts & Sciences Electronic Theses and Dissertations

At ambient pressure all lanthanide metals order magnetically at temperatures at or below ambient. The magnetic ordering is known to result from the indirect exchange interaction between localized 4f magnetic moments mediated by the surrounding conduction electrons, the so-called Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. With the RKKY interaction the magnetic ordering temperature To is expected to be proportional to the de Gennes factor which is a function of the Landé g factor gJ and the total angular momentum J. For example, Gd has the highest value of To, 292 K, at ambient pressure as it has the largest de Gennes factor of …

Structure And Function Of Cytochrome Containing Electron Transport Chain Proteins From Anoxygenic Photosynthetic Bacteria, Erica Lois-Wunderlich Majumder

Arts & Sciences Electronic Theses and Dissertations

This dissertation examines the structure and function of photosynthetic proteins that contain c-type heme cofactors that function in the electron transport chains of anaerobic phototrophic bacteria. The diversity and range of these cytochromes proteins was explored. Then, individual proteins were studied in detail. The diheme cytochrome c from Heliobacteria modesticaldum was studied using hydrogen deuterium exchange mass spectrometry and homology modeling. A structural model of the protein and a mechanism for the cytochrome bc complex was proposed. Next, the monoheme cytochrome c subunit from the Alternative Complex III from the Filamentous Anoxygenic Phototrophs was studied using biochemistry and found to …

Thermophysical Properties And Structural Evolution Of Supercooled Metallic Liquids, Matthew Blodgett

Arts & Sciences Electronic Theses and Dissertations

Metallic glasses (and glasses in general) offer unique material properties compared to their crystalline counterparts. Yet the physics of the glass transition remain poorly understood. By examining the evolution of properties in the liquid as it is cooled toward the glass transition we hope to discern how they relate to glass formation.

Of particular interest is the concept of kinetic fragility, first defined in terms of the viscosity behavior near the glass transition, and what it means for a high temperature liquid to be “fragile” or “strong.” This dissertation presents several studies of metallic liquids using the electrostatic levitation technique. …

Incompatibility Of Diophantine Equations Arising From The Strong Factorial Conjecture, Brady Jacob Rocks

Arts & Sciences Electronic Theses and Dissertations

The Strong Factorial conjecture was recently formulated by Arno van den Essen and Eric Edo. The problem is motivated by several outstanding problems including the Jacobian, Image, and Vanishing conjectures. In this defense, we discuss how the conjecture can be reformulated in terms of systems of integer polynomials and we present several special cases in which the conjecture holds.

Mass Spectrometry-Based Strategies For Biomolecular Structure Analysis: Steroid Metabolites Structures And Protein-Protein Interactions, Yuetian Yan

Arts & Sciences Electronic Theses and Dissertations

Mass spectrometry is an important method for studying the structure of both small molecules and large biomolecules (e.g., proteins). The majority of the applications prior to 1970 were focused on small molecules, owing to the limited ionization methods which posed difficulties in producing gas-phase ions for large biomolecules then. Beginning in the 1980's, with the introduction of new ionization methods (ESI and MALDI), the applications have gradually switched to biological science measuring large bioorganic molecules. Today, with the developing interest in metabolomics and proteomics, and ongoing improvement in MS-based techniques, mass spectrometry is extensively applied in the study of both …

Light-Harvesting, Redox Control, And Biomimicry Of The Photosynthetic Antennas Of Green Sulfur Bacteria, Gregory Scott Orf

Arts & Sciences Electronic Theses and Dissertations

The green sulfur bacteria (class Chlorobea) are obligately anaerobic photoautotrophic prokaryotes. Members of this bacterial class are found in anoxic, sulfur- or iron-rich environments such as hydrothermal vents and hot springs. These bacteria are champions of lowlight adaptation, with some species being able to thrive photosynthetically on less than eight photons hr-1 per pigment. We have studied the two photosynthetic antenna complexes from these organisms that are responsible for light capture: the chlorosome and the Fenna-Matthews-Olson (FMO) protein.

In regards to the chlorosome, we studied, using steady-state and time-resolved spectroscopic methods, the effect of incorporation of an expected, but as-yet-undiscovered-in-nature, …

Development And Application Of Mass Spectrometry-Based Biophysical Approaches, Ying Zhang

Arts & Sciences Electronic Theses and Dissertations

Mass spectrometry (MS)-based biophysical approaches are new "tools" for protein characterization owing to its capability to analyze proteins and protein complexes that range in molecular weight from kDa to MDa. Protein characterization requires more than identifying the primary structure. More importantly, protein high order structures (i.e., secondary, tertiary and quaternary structures) are needed for biological studies. MS has become the major tool in studies of protein primary structure and post translational modifications (PTMs) over the past two decades. Because MS has high sensitivity and fast turnaround, more and more biophysical approaches rely on MS to generate information for protein higher …

Correlated Nanosims, Tem, And Xanes Studies Of Presolar Grains, Evan Edward Groopman

Arts & Sciences Electronic Theses and Dissertations

The objective of this thesis is to describe the correlated study of individual presolar grains via Nano-scale Secondary Ion Mass Spectrometry (NanoSIMS), Transmission Electron Microscopy (TEM), and Scanning Transmission X-ray Microscopy (STXM) utilizing X-ray Absorption Near Edge Structure (XANES), with a focus on connecting these correlated laboratory studies to astrophysical phenomena. The correlated isotopic, chemical, and microstructural studies of individual presolar grains provide the most detailed description of their formation environments, and help to inform astrophysical models and observations of stellar objects.

As a part of this thesis I have developed and improved upon laboratory techniques for micromanipulating presolar grains …

Ion Interactions At The Mineral-Water Interface During Biogeochemical Iron And Manganese Cycling, Margaret A. G. Hinkle

Arts & Sciences Electronic Theses and Dissertations

The biogeochemical cycling of iron and manganese involves the reductive dissolution and oxidative precipitation of Fe(III) and Mn(IV/III) oxides. Biogenic Fe(III) and Mn(IV/III) oxides are often characterized by high surface areas and therefore high sorptive capacities. As a result, these minerals can substantially alter the chemistry of natural waters and the availability of micronutrients in soils and sediments by scavenging trace metals. Recent research indicates that the adsorption of aqueous Fe(II) onto Fe(III) oxides involves oxidative adsorption, electron transfer, and subsequent reductive dissolution at another surface site [a process collectively referred to as `electron transfer-atom exchange' (ET-AE)]. Aqueous Mn(II) adsorption …

Regularity Of The Bergman Projection On Variants Of The Hartogs Triangle, Liwei Chen

Arts & Sciences Electronic Theses and Dissertations

The Bergman projection is the orthogonal projection from the space of square integrable functions onto the space of square integrable holomorphic functions on a domain. Initially, the projection is defined on the L2 space, but its behavior on other function spaces, e.g. Lp, Sobolev and Holder spaces, is of considerable interest.

In this dissertation, we focus on the Hartogs triangle which is a classical source of counterexamples in several complex variables, and generalize it to higher dimensions. We investigate the Lp mapping properties of the weighted Bergman projections on these Hartogs domains. As applications, we obtain the Lp regularity of …

Neural Processing In The Three Layer Turtle Visual Cortex, Jeffrey Steven Pobst

Arts & Sciences Electronic Theses and Dissertations

In this thesis we investigate neural processing in turtle visual cortex. To this end, we characterize the nature of both spontaneous, ongoing neural activity as well as activity evoked by visual stimulation. Data are collected from whole brain eye-attached preparations, recording with extracellular and intracellular electrodes. We investigate the activity of action potentials as well as the slower local field potential activity.

To investigate response properties, we explore spatial properties of receptive fields, temporal properties of spontaneous and evoked activity, response adaptation, and correlations between different types of activity as well as between activity recorded in different regions.

To study …

Synthesis, Structure, Spectroscopy, And Reactivity Of Azapentadienyl-Ruthenium-Phosphine Complexes, Meghan Leigh Stouffer

Arts & Sciences Electronic Theses and Dissertations

This dissertation focuses on the systematic synthesis of ¬bis-azapentadienyl-ruthenium-phosphine complexes. The synthetic approach involves the treatment of Cl2Ru(PPh3)3 with potassium tert-butylazapentadienide reagent. The reactivity of this parent compound with other 2e- donor ligands is investigated. These resultant complexes' reactivity with triflic acid is also studied.

Treatment of Cl2Ru(PPh3)3 with potassium tert-butylazapentadienide produces [(1,2,3-η3)-5-tert-butylazapentadienyl]2Ru(PPh3)2 (1). Compound 1 undergoes single substitution of one of the triphenylphosphines when treated with PMe3, dmpe, P(OMe)3, CNCMe3, CO, and PEt3 at room temperature, resulting in [(1,2,3-η3)-5-tert-butylazapentadienyl]2Ru(PPh3)(L) (2, L = PMe3; 3, L= dmpe; 4, L = P(OMe)3; 5, L = CNCMe3; 6, L = CO; 7, …

Application Of Machine Learning To Mapping And Simulating Gene Regulatory Networks, Hien-Haw Liow

Arts & Sciences Electronic Theses and Dissertations

This dissertation explores, proposes, and examines methods of applying modernmachine learning and Bayesian statistics in the quantitative and qualitative modeling of gene regulatory networks using high-throughput gene expression data. A semi-parametric Bayesian model based on random forest is developed to infer quantitative aspects of gene regulation relations; a parametric model is developed to predict geneexpression levels solely from genotype information. Simulation of network behavior is shown to complement regression analysis greatly in capturing the dynamics of gene regulatory networks. Finally, as an application and extension of novel approaches in gene expression analysis, new methods of discovering topological structure of gene …

Kinematic Modeling Of The Determinants Of Diastolic Function, Leonid Shmuylovich

Arts & Sciences Electronic Theses and Dissertations

Multiple modalities are routinely used in clinical cardiology to determine cardiovascular function, and many of the indexes derived from these modalities are causally interconnected. A correlative approach to cardiovascular function however, where indexes are correlated to disease presence and progression, fails to fully capitalize on the information content of the indexes.

Causal quantitative modeling of cardiovascular physiology on the other hand offers a predictive rather than accommodative approach to cardiovascular function determination. In this work we apply a kinematic modeling approach to understanding diastolic function. We discuss novel insights related to the physiological determinants of diastolic function, and define novel …

Nonparametric Bayesian Quantile Regression Via Dirichlet Process Mixture Models, Chao Chang

Arts & Sciences Electronic Theses and Dissertations

We propose new nonparametric Bayesian approaches to quantile regression using

Dirichlet process mixture (DPM) models. All the existing quantile regression methods

based on DPMs require the kernel density to satisfy the quantile constraint, hence the

kernel densities are themselves usually in the form of mixtures. One innovation of our

approaches is that we impose no constraint on the kernel, thus a wide range of densities

can be chosen as the kernels of the DPM model. The quantile constraint is satisfied by a

post-processing of the DPM by a suitable location shift. As a result, our proposed models

use simpler kernels …

Photometric Investigations Of Lunar Landing Sites And Silicic Regions Using Lro Narrow Angle Camera Images, Ryan Nicole Watkins

Arts & Sciences Electronic Theses and Dissertations

The reflectance properties of a planetary surface are related to the physical and compositional properties of that body. Photometry is a powerful method for determining differences in composition and regolith structure, and photometric data from orbital images coupled with soil sample data can greatly enhance our understanding of the regolith properties of our nearest neighbor, the Moon. At the time of writing, the United States has no operating missions on the Moon and no future plans to send robots or humans to study our nearest neighbor, so we must rely on remote sensing data to provide us with information about …

Wavelet Factorization And Related Polynomials, David Meyer

Arts & Sciences Electronic Theses and Dissertations

Our goal is exploring and better understanding factorizations of polyphase matrices for finite impulse response (FIR) filters. In particular, we focus on nearest neighbor factorizations discussed by Wickerhauser and Zhu that allow for efficient implementation of the discrete wavelet transform (DWT) for the algorithms of Daubechies and Sweldens and Mallat. Nearest neighbor lifting is a specific form of the general lifting scheme that improves the lifting algorithm by optimizing the number of efficient memory accesses. Nearest neighbor lifting factorizations are typically generated by implementing the Euclidean algorithm for Laurent polynomials, which introduces multiple choices of factorizations of a polyphase matrix …