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Non-Adjacent Anti Cyclobutane Pyrimidine Dimers As Intrinsic Probes Of Non-B Form Secondary Structures Of Dna, Natalia Eugenia Gutierrez Bayona

Arts & Sciences Electronic Theses and Dissertations

G-quadruplexes are four-stranded structures of DNA composed of G-quartets that have been proposed to play an extremely important role in replication, transcription, and translation. It has, however, been extremely difficult to unequivocally demonstrate that G-quadruplexes form in living cells due to the lack of probes that would allow for their unambiguous detection and location without disrupting the DNA or the cellular environment. To circumvent these problems, it was proposed that DNA itself could be used as an intrinsic photoprobe for certain classes of G-quadruplex structures and other non-B DNA conformations in vivo. Recently, we discovered that UVB irradiation of human …

A Torsion Balance Search For Long-Range Interactions Coupling To Baryons And Leptons And Cosmic Ray Transport For Spatially And Temporally Continuous And Discrete Sources, Dawson Huth

Arts & Sciences Electronic Theses and Dissertations

Part I: The expectation of new physics motivates more stringent tests of our current best understanding of gravitation, General Relativity (GR). Many theories proposing new physics predict the violation of Einstein’s equivalence principle, a set of criteria which must hold for GR to be valid. A torsion balance instrument was designed and operated to detect any violation of the equivalence principle. The motivations for performing such an experi- ment, instrument design, operational principles, data collected and subsequent analysis are described in detail in this thesis. After 51 days of continuous data collection experimental upper bounds on the violation of the …

New Methods Of Selectivity Using Electrochemistry, Qiwei Jing

Arts & Sciences Electronic Theses and Dissertations

This project has been working on introducing new type of method to induce chemoselectivity into electrochemical reactions by modifying the surface of an electrode and then confining chemical reactions to the region of the reaction close to that surface. The goal is to translate the extremely high levels of site-selectivity seen in chemical reactions on a microelectrode array into a tool for preparative synthetic reactions.As a proof-of-principle experiment, Pt-anode was coated with a diblock copolymer that is known to have an affinity for pyrene groups. The electrode is then used in the oxidation of two alcohol substrates: one having the …

Spike-Timing-Dependent Plasticity Alters Sensory Network Connectivity, Adalee Lube

Arts & Sciences Electronic Theses and Dissertations

A fundamental question in neuroscience is: how does a sensory system optimize detection of behaviorally relevant stimuli, when those stimuli and the sensory environment are constantly changing? Spike-timing-dependent plasticity (STDP), in which synapse strength changes based on the relative timing of pre- and post-synaptic spiking, has been implicated in changes in neuronal connectivity thought to underlie learning and memory. Synaptic strength changes caused by STDP have been shown in optic tectum, visual cortex, hippocampus, and other brain regions in vitro across many organisms like fish, frogs, and mice. Although it is possible that STDP mechanisms underlie changes in sensory neuron …

The Monumentalization Of The Past: German Humanist Patriotism And Source Use, 1488–1582, Justin Meyer

Arts & Sciences Electronic Theses and Dissertations

The development of a patriotic discourse among German Renaissance humanists emerged from a humanist desire to memorialize the past by gathering information from the sources of German history and geography. Prevailing scholarly arguments explain the emergence of this discourse as a result of cultural conflict with Italian humanists who reproached the Germans for their barbarity. This explanation, which I call the Conflict Model, is inadequate as a means to explain the phenomenon of this patriotism because it relies on too few sources. This dissertation rests on a far more expansive source base in which cultural conflict is a limited but …

Musical And Spiritual Meaning In The Franciscan Works Of Franz Liszt, Jorge Luis Modolell

Arts & Sciences Electronic Theses and Dissertations

Liszt’s relationship to St. Francis of Assisi was an integral part of the composer’s identity. His devotion to the saint, cultivated from an early age, served as a constant source of spiritual guidance that only grew stronger over time. Texts by St. Francis and anecdotes from the saint’s life provided the artistic incentive for a number of important works, which form the core of the present study. By examining several of these works together, with full analyses and within a broader cultural framework, this dissertation aims to arrive at a true understanding of the messages Liszt took from this figure …

Essays In International Reserves And Sovereign Risk, Rocio E. Suarez

Arts & Sciences Electronic Theses and Dissertations

Since the 1990s, international reserves accumulation has particularly surged in emerging economies. What are the rationals behind this rise and the implications of international reserves accumulation for emerging economies? Chapter 1 of the dissertation, titled The Effects of Reserves Accumulation on Sovereign Default Under Terms of Trade Shocks, studies what is the value of holding international reserves in emerging economies when they experience fluctuations in their terms of trade and the sovereign debt is denominated in foreign currency. Firstly, I document stylized facts regarding a sample of emerging economies over the period 1997-2019 and find that there is a negative …

Discrimination And Health Disparities: Sense Of Purpose As A Mitigating Factor, Megan Elizabeth Wilson

Arts & Sciences Electronic Theses and Dissertations

Racial health disparities exist in the United States, and exist in part due to negative effects of experiencing discrimination on health. Thus, the current work uses subjective and objective health outcomes to document the ill effects of discrimination on aspects of physical and mental health. In addition, as sense of purpose in life has been shown to have a positive impact on one’s health, the current work examines the effect of sense of purpose on the same health outcomes, and assesses the extent to which sense of purpose may help to mitigate some of the harmful effects of discrimination on …

Improving Neoantigen Prioritization Methods For Personalized Cancer Vaccines, Huiming Xia

Arts & Sciences Electronic Theses and Dissertations

Neoantigens are novel peptide sequences resulting from sources such as somatic mutations in tumors. Upon loading onto major histocompatibility complex (MHC) molecules, they can trigger recognition by T cells. Neoantigen targeting therapies including personalized vaccines have shown promise in the treatment of cancers, particularly when used in combination with checkpoint blockade therapy. Thus, accurate identification and prioritization of neoantigens is critical for conducting neoantigen-based clinical trials, predicting treatment response, and understanding mechanisms of resistance. With the advent of whole exome and RNA sequencing technologies, researchers and clinicians are now able to computationally predict neoantigens based on patient-specific mutation information. However, …

Essays On Market Reallocation And Economic Growth, Lei Ye

Arts & Sciences Electronic Theses and Dissertations

The purpose of this dissertation is to study the causal factors that contribute to the reallocation of economic activity in the product, financial and labor market, and to analyze the implications of these phenomena on the aggregate economic performance.

The dissertation consists of three chapters. The first chapter, "Bank Concentration, Product Market Competition and Firm Dynamics", investigates the concentration trend in the U.S. banking industry since the implementation of the Riegle-Neal Act in 1994 and its impact on product market competition, firm dynamics and aggregate economic performance. Empirically, I document that bank concentration is associated with less competition in product …

Essays On Firms, Debt Contracts And Equity Market, Rusi Yan

Arts & Sciences Electronic Theses and Dissertations

Debt Contracts, Outside Equity and Financial Development: How important are different financial contracts for economic development? Using cross-country firm-level data, I document the extensive usage of alternative debt contracts and ownership structure patterns for public firms. At the aggregate level, development in each segment of the financial system is significantly linked to GDP per capita and wealth inequality. To quantify the aggregate consequences, I develop a heterogeneous agent model of entrepreneurs who face asset-based or cash flow-based debt and outside equity frictions. The model is calibrated to a large set of countries in vastly different stages of financial development. Quantitatively, …

Essays On Statistical Inference, Nonconvex Optimization And Machine Learning, Yanjie Zhong

Arts & Sciences Electronic Theses and Dissertations

Over the past decades, numerous optimization and machine learning (ML) algorithms have been proposed, many of which have demonstrated success in real-world applications and significantly impacted people's lives. Researchers have devoted considerable effort to understanding the theoretical underpinnings of these methods and to improving their performance, as well as designing algorithms compatible with demanding real-world constraints. This dissertation focuses on investigating the statistical properties of several mainstream optimization and ML algorithms, enabling us to make decisions with statistical guarantees.

First, we examine the classical stochastic gradient descent algorithm (SGD) in a general nonconvex context. Utilizing the multiplier bootstrap technique, we …

Investigating Disease Progression And Therapeutic Targets In Multiple Myeloma Using Single-Cell Technologies, Lijun Yao

Arts & Sciences Electronic Theses and Dissertations

Multiple Myeloma (MM) is a highly heterogeneous disease characterized by uncontrolled clonal expansion of plasma cells. Single-cell techniques are advantageous in providing a more granular understanding of inter- and intratumoral genomics and surrounding microenvironments. The high relapse rate and intrinsic complexity of MM make the application of single-cell technologies particularly beneficial. Understanding the concordance of the measurements across single cell techniques in MM is of great interest. In this dissertation, we first integrated three single-cell technologies, namely scRNA-seq, CyTOF, and CITE-seq, to characterize MM immune microenvironment and assess their concordances of measurement. Overall, cell type abundances were relatively consistent, while …

Abundances Of Ultra-Heavy Cosmic Ray Nuclei With Calet, Wolfgang Vaughn Zober

Arts & Sciences Electronic Theses and Dissertations

This work describes the determination of the relative abundances of the Galactic Cosmic-Ray (GCR) nuclei from Z=9 through Z=40, with preliminary measurements up to Z=44, using the Calorimetric Electron Telescope (CALET) on board the International Space Station (ISS). This analysis will compare results with the top-of-atmosphere abundances from the balloon-borne SuperTIGER and top-of-instrument abundances from the space missions, ACE-CRIS and HEAO-3. This analysis also provides insight into the potential opportunities and challenges for a future SuperTIGER-like mission on the ISS.

Our analysis looks at work on two separate but complementary aspects of the Ultra-Heavy (UH) analysis in CALET. CALET has …

Mechanisms Of Transcription Regulation By Card In Mycobacterium, Dennis Xiaoqian Zhu

Arts & Sciences Electronic Theses and Dissertations

Mycobacterium tuberculosis (Mtb) is an important human pathogen that is responsible for over 1 million deaths each year. As a bacterial pathogen, Mtb is highly adapted to survival within the host environment, which imposes numerous environmental stresses on the bacteria. To survive these challenges, Mtb utilizes a network of transcription factors to adapt its gene expression and physiology. CarD is an essential transcription factor in mycobacteria that binds directly to RNA polymerase (RNAP) rather than DNA sequence motifs on the chromosome. Prior mechanistic studies of CarD’s function in mycobacteria have been limited to studies of CarD’s effects on individual kinetic …

Trpm5'S Role In Vascular Development, Megan Goeckel

Arts & Sciences Electronic Theses and Dissertations

Blood vessels are composed of two main cell types, endothelial cells (ECs) and mural cells (MCs). Endothelial cells comprise of the inner-most layer of the vessel and sense changes in blood flow to recruit mural cells. The mechanism for how endothelial cells sense these hemodynamic changes is not well understood and deciphering this mechanism is the focus of this thesis. We hypothesize that transient receptor potential melastatin 5 (TRPM5), a transmembrane channel protein, is involved in this process. Here, using cultured human endothelial cells and the zebrafish model, we show that inhibition of TRPM5 decreases vessel formation and increases EC-MC …

Identification And Characterization Of Targets Of Metastasis In High-Grade Serous Ovarian Cancer, Emilee Nicole Kotnik

Arts & Sciences Electronic Theses and Dissertations

High-Grade Serous Ovarian Cancer (HGSC) is a highly metastatic cancer with the majority of patients presenting in advanced stages. Currently there are limited targeted treatment options for patients, especially for women with high metastatic tumor burdens. In order to improve patient outcomes, we have aimed to identify and characterize novel targets of metastasis utilizing sequencing from patient tumors and a functional genomic screen. First, we identified genetic alterations of metastasis and short survival by characterizing the genomic and transcriptomic alterations of primary and metastatic tumors in HGSC patients from 23 short-term survivors (overall survival (OS)5 years). We compared somatic mutations, …

The “Dread Sex Cases:” Community, Citizenship, And The Regulation Of Adult Theaters In The 1970s, Erin Barry

Arts & Sciences Electronic Theses and Dissertations

Through an innovative examination of scale (local, state, and national regulatory structures), space (the location of theaters, the spatial arrangements inside them) and place (the cities and suburbs in which these battles took place), my dissertation on the regulation of adult theaters in the 1970s raises compelling questions about sexuality, space and the various levels at which citizenship is enacted and policed. I utilize three Supreme Court cases, Paris Adult Theater v. Slaton, which dealt with consent and the application of community standards, Erznoznik v. Jacksonville, which addressed bans on nudity and pornography at drive-in theaters, and Young v. American …

Maternal-Fetal Circadian Communication During Pregnancy, Keenan Bates

Arts & Sciences Electronic Theses and Dissertations

Circadian rhythms in gene expression and hormones are ubiquitous across species and across cell types. Circadian rhythms depend on a transcription-translation negative feedback loop that drives many daily rhythms in behavior and physiological processes. Circadian rhythms regulate many aspects of reproduction, such as fetal development and birth timing. Mammalian pregnancy presents a unique situation with circadian rhythms in the mom and, eventually, in the fetus. Prior studies showed that circadian rhythms develop in utero and that maternal signals, such as glucocorticoids, may act to entrain or drive daily rhythms in the fetus. However, there remains considerable debate about when and …

Mechanisms And Consequences Of Microtubule-Based Symmetry Breaking In Plant Roots, Natasha Anriel Bilkey

Arts & Sciences Electronic Theses and Dissertations

Directional growth in plants is primarily determined by the axis of cell expansion, which is specified by the net orientation of cortical microtubules. Microtubules guide the deposition of cellulose and other cell wall materials. In rapidly elongating cells, transversely oriented microtubules create material anisotropy in the cell wall that prevents radial cell expansion, channeling cell expansion in the longitudinal direction. Mutations perturbing microtubule organization frequently lead to aberrant cell growth in land plants, with some mutations leading to helical growth patterns (called ‘twisted mutants’), often in roots. This phenotype manifests as right-handed or left-handed twisting of cell files along the …

Identifying The Molecular Fate Logic Underlying Direct Neuronal Conversion, Kitra Cates

Arts & Sciences Electronic Theses and Dissertations

The development of techniques to model adult-onset neurodegeneration are increasingly important as the global aging population rises. Neurodegenerative disease modeling using cellular reprogramming requires the generation of neurons that recapitulate molecular signatures of neuronal cell identity, maturity, and pathogenesis. Ectopic expression of microRNAs-9/9* and microRNA-124 (miR-9/9*-124) directly convert human adult dermal fibroblasts (hDF) into microRNA-induced neurons (miN). This direct conversion provides a platform to study adult-onset neurodegeneration, as it bypasses pluripotency and maintains molecular age-associated properties of patient-derived cells. In coordination with transcription factors, miR-9/9*-124 reprogramming can generate subtype-specific neurons, which can be used for the study of genetic processes …

Wide-Field Optical Imaging Of Neurological Disorders And Sleep In Mice, Lindsey M. Brier

Arts & Sciences Electronic Theses and Dissertations

Neuroimaging has revolutionized the way in which we understand the hierarchical organization of the amazingly complex, interconnected human brain. Neuroimaging techniques, like functional magnetic resonance imaging (fMRI), have provided high quality structural and functional data, providing multiple in-depth analyses and biomarkers of disease processes. In animal models, mechanistic studies can uncover root pathologies that aren’t explorable in humans. In mice, brain functional connectivity (FC) can be measured via Optical Intrinsic Signal (OIS) imaging – a modality that measures vascular reactivity as a surrogate for neural activity via quantification of fluctuations in oxygenated-hemoglobin (similar to the blood oxygen level dependent (BOLD) …

Assessment Of Cross-Protective Responses To Emerging Variant Viruses, Rita Elaine Chen

Arts & Sciences Electronic Theses and Dissertations

Viruses pose a great threat to human health. Outbreaks and pandemics due to different viruses occur in all areas of the world. Two viruses, which emerged globally in the 1980s and in 2020, that are still causing ongoing pandemics in 2021 are dengue virus (DENV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), respectively. These viruses circulate widely and currently infect hundreds of millions of people. Immunity from a previous infection may confer protection against subsequent infection of a related virus. Thus, understanding the degree of cross-protection can help define correlates of protection that are necessary to determine which people …

Mapping Brain Development And Decoding Brain Activity With Diffuse Optical Tomography, Kalyan Tripathy

Arts & Sciences Electronic Theses and Dissertations

Functional neuroimaging has been used to map brain function as well as decode information from brain activity. However, applications like studying early brain development or enabling augmentative communication in patients with severe motor disabilities have been constrained by extant imaging modalities, which can be challenging to use in young children and entail major tradeoffs between logistics and image quality. Diffuse optical tomography (DOT) is an emerging method combining logistical advantages of optical imaging with enhanced image quality. Here, we developed one of the world’s largest DOT systems for high-performance optical brain imaging in children. From visual cortex activity in adults, …

Immunity To Emerging Rna Viruses, Emma Winkler

Arts & Sciences Electronic Theses and Dissertations

In the past decade, newly emerged and re-emerged pathogenic RNA viruses such as Ebola, H1N1, and Zika virus have become substantial threats to global health. Two notable examples include the explosive re-appearance of chikungunya virus in the 2000s in Asia and the Western Hemisphere and, more recently, the global COVID-19 pandemic. Therefore, an improved understanding of immunity to emerging RNA viruses is critical for defining host susceptibility and restriction factors to viral infection as well as appropriate vaccine and antiviral therapeutic design. Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that is maintained in an urban epidemic transmission cycle. While most …

Using In Situ Single-Particle Imaging To Understand The Role Of Structural Distortions During Anion Exchange In Cesium Lead Halide Perovskite Nanocrystals, Dongyan Zhang

Arts & Sciences Electronic Theses and Dissertations

Colloidal cesium lead halide (CsPbX3, X = Cl, Br, I) perovskite nanocrystals are being investigated as promising materials for light-emitting devices and fluorescence probes due to their strong absorption and emission (1.55 eV – 3.05 eV) of visible light. Anion exchange is a facile, post-synthetic method to tune the bandgap emission of CsPbX3 nanocrystals, covering most of the spectrum of visible light. However, structural heterogeneities in nanocrystals formed during anion exchange will lead to lower photoluminescence quantum yield and a broader range of emission wavelengths. A single batch of nanocrystals will contain a distribution of sizes, shapes, surface structures, and …

Influence Of Environmental Gradients On Genomic Variation In Pediatric Commensals And Pathogens, Sanjam Sawhney

Arts & Sciences Electronic Theses and Dissertations

Microbes interact with humans in a myriad of ways. They come together in the human gut to form complex communities that collectively transform and individually evolve in response to changing environmental conditions. Individual microbes can also cause human infection and escape antibiotic clearance through acquisition and development of novel resistance mechanisms. In this thesis, I chronicle the relationships between microbes and humans across two axes: from complex communities to single isolates, and from targeted studies of pediatric populations vulnerable to microbiome perturbations and pathogen challenge, to broader human and animal cohorts spanning colonizing and diagnostic environments.

In Chapter 2, I …

Solo Dance In Greek And Roman Comedy, Marleigh Anderson

Arts & Sciences Electronic Theses and Dissertations

In the first full-length study focusing exclusively on comic solo dance, I argue for the presence and significance of solo dance in both Greek and Roman comedy. My dissertation aims to answer two driving questions: where does solo dance (broadly defined as dance by actors) occur in extant Greek and Roman comedy, and how does such dancing contribute to the plays? The introduction lays out my methodology for approaching these questions. My study then moves from what can be known with certainty (definite solo dance scenes and references to dance) to what requires more speculation (likely dance scenes). Chapter one, …

Restoring The Mechanoresponsiveness Of Aged Bone To Mechanical Loading, Christopher John Chermside-Scabbo

Arts & Sciences Electronic Theses and Dissertations

Osteoporosis—a disease of low bone mass and a predisposition to fracture—remains a pressing public health burden. Osteoporotic fractures occur in 1 in 3 women and 1 in 5 men over the age of 50, at a cost of more than $22 billion annually in the US. To prevent osteoporotic fractures, we need additional strategies to increase bone formation and reverse the disease. A potent strategy to increase bone formation is mechanical loading. However, with aging, bone becomes less responsive to the same stimulus. Because we do not fully understand the age-related decrease in bone mechanoresponsiveness, we have been unable to …

Wild Plant–Pathogen Interactions Across Gradients Of Urbanization And Latitude, Quinn N. Fox

Arts & Sciences Electronic Theses and Dissertations

In light of large-scale urbanization and rising global temperatures, it is essential to understand how environmental and climatic changes impact the ecology and evolution of species interactions. This thesis investigates interactions between wild plants and their pathogens across gradients in land use and latitude, and specifically tests the effects of multiple scales of climate variation on such interactions. In this work, I focused on a system of common herbaceous plants in the genus Plantago and their fungal powdery mildew pathogens. I studied their interactions across an urbanization gradient transecting the metropolitan area of St. Louis, Missouri and along a latitudinal …