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Multidimensional Spectroscopy Of Mixed-Cation Perovskite Thin Films, Geoffrey Michael Diederich

Electronic Theses and Dissertations

Metal halide perovskite (MHP) thin films are currently undergoing an intense re- search thrust due to the excellent performance of MHP based photovoltaic (PV) devices, which have the potential to revolutionize the worlds energy production via a unique combination of low-cost fabrication and high power conversion efficiency (PCE). However, the vast majority of research is currently aimed at incremental improvements in device PCE, resulting in a body of work without the foundational understanding of the charge-carrier dynamics of the system upon photoexcitation.

This thesis begins with the development of a phase-modulated multidimensional coherent spectroscopy (PM-MDCS) experiment. PM-MDCS is an ultrafast …

Photoassisted Synthesis Of Complex Polyheterocycles Via Esipt-Driven Dearomative Intramolecular Cycloadditions, Dmitry Kuznetsov

Electronic Theses and Dissertations

This research is focused on the development of novel photoassisted synthetic methodologies that provide straightforward access to complex and diverse libraries of polyheterocycles from modularly assembled precursors. All methods are based on the dearomative cycloadditions between two components: (i) o-azaxylylenes, generated by the excited-state intramolecular proton transfer, and (ii) tethered arene groups.

We have demonstrated the synthetic utility of four new photoinduced processes that yield complex products amenable for post-photochemical modifications:

• [4+4] Cycloaddition of o-azaxylylenes to 1,3,4-oxadiazoles with subsequent dinitrogen extrusion. This reaction furnishes compounds outfitted with epoxide fragments, which undergo ring-openings with various nucleophiles; furthermore, the oxidized products …

Lewis Base Promoted Annulations Of Allenoates With 1,4-Naphthoquinones, Nicole Marie Shoup

Electronic Theses and Dissertations

Lewis base promoted cyclization of allenoates with electron deficient olefins open up the possibility to generate more complex organic structures. By generating more complex molecules, we are able to produce new compounds for biomedical and material applications. Both phosphine and amine Lewis bases offer interesting annulations with allenoates resulting in Lu or Morita–Baylis–Hillman type reactions. Once the Lewis base engages with the allenoate there can be several modes of nucleophilic reactivity that allows for the allenic ester to act as a two or three carbon synthon. The allenoate can then react with varying electron deficient olefins generating more complex molecules …

Barrier Graphs And Extremal Questions On Line, Ray, Segment, And Hyperplane Sensor Networks, Kirk Anthony Boyer

Electronic Theses and Dissertations

A sensor network is typically modeled as a collection of spatially distributed objects with the same shape, generally for the purpose of surveilling or protecting areas and locations. In this dissertation we address several questions relating to sensors with linear shapes: line, line segment, and rays in the plane, and hyperplanes in higher dimensions.

First we explore ray sensor networks in the plane, whose resilience is the number of sensors that must be crossed by an agent traveling between two known locations. The coverage of such a network is described by a particular tripartite graph, the barrier graph of the …

Characterization Of Vps41 And Its Role In The Regulated Secretory Pathway, Christian Henry Burns

Electronic Theses and Dissertations

Insulin secretory granules (SGs) mediate the regulated secretion of insulin, which is essential for glucose homeostasis. The basic machinery responsible for this regulated exocytosis consists of specific membrane proteins present both at the plasma membrane and on insulin SGs. The protein composition of insulin SGs thus dictates their release properties, yet the mechanisms controlling insulin SG formation, which determines this molecular composition, remain poorly understood. VPS41, a component of the endolysosomal tethering HOPS complex, was recently identified as a cytosolic factor involved in the formation of neuroendocrine/neuronal granules. We now find that a stable pool of VPS41 exists outside of …

Translation Of Partially Decayed Messenger Rnas In Yeast, Ana Luisa Franklin

Electronic Theses and Dissertations

Flaviviruses are positive-strand single-stranded RNA viruses that are known to form pseudo-knot RNA structures that halt the progression of 5’→3’ exonuclease Xrn1. We show that these viral Xrn1-resistant structures (xrRNAs) can be used to protect specific homologously-expressed messenger RNAs from 5’→3’ degradation. We investigated the effects of addition of xrRNAs, artificially-installed into the intergenic region of bicistronic mRNA reporters, in the observed levels of protein expression in yeast. The reporters also contain an internal ribosome entry site from the cricket paralysis virus (CrPV IRES) to allow for cap-independent translation of the decay-protected gene, LacZ, encoding the enzyme β-galactosidase. Through …

Development Of A Hek293 Cell Line To Show Inhibition Of Tau Aggregation, Justin Ray Shady

Electronic Theses and Dissertations

Intracellular deposition of aggregated tau is the hallmark of several different tauopathies, the most widespread of these being Alzheimer's disease. Tau is a highly soluble, intrinsically disordered, microtubule associated protein. Tau's native function is to stabilize microtubule formation in the axons of neurons. Post translational modification such as hyperphosphorylation as well as several familial mutations allow tau to nucleate and form fibrils. These fibrils can recruit healthy monomers onto their ends in a fashion described as template-assisted growth. Tau has 6 isoforms that vary by the inclusion or exclusion of two N-terminal repeats and the inclusion or exclusion of the …

Decidability For Residuated Lattices And Substructural Logics, Gavin St. John

Electronic Theses and Dissertations

We present a number of results related to the decidability and undecidability of various varieties of residuated lattices and their corresponding substructural logics. The context of this analysis is the extension of residuated lattices by various simple equations, dually, the extension of substructural logics by simple structural rules, with the aim of classifying simple equations by the decidability properties shared by their extensions. We also prove a number of relationships among simple extensions by showing the equational theory of their idempotent semiring reducts coincides with simple extensions of idempotent semirings. On the decidability front, we develop both semantical and syntactical …

Corporate-Community Mining Conflicts In Guatemala: Unsettling Hegemonic Power Relations In Environmental Struggles, Anna Guðbjört Sveinsdóttir

Electronic Theses and Dissertations

This dissertation analyzes corporate-community conflicts around extractive industries in Guatemala with the purpose of better understanding how environmental struggles emerge and take shape. The study uses environmental governance as a framework to analyze the processes, institutions, actors and discourses that shape the conditions of possibility of political action and mobilization in environmental struggles. The dissertation argues that to understand the conditions of possibility of political action and mobilization in environmental struggles we must study the interplay between political actions 'from above' and 'from below', which are seen as dialectically interrelated, with dynamic and contested interactions between actors within and between …

Characterization Of A Phosphomimetic Mutant Of The Als Associated Protein Tdp-43, Nicole Toro

Electronic Theses and Dissertations

Trans-activation response (TAR) DNA-binding protein 43 (TDP-43) is a natively dimeric 414-residue protein that is encoded by the human TARDBP gene that has important implications in the pathogenesis of the neurodegenerative disorders ALS, FTD, and CTE. TDP-43 has been found hyperphosphorylated and ubiquitinated in the aggregates of the affected neurons of these diseases. The discovery of the presence of TDP-43 positive inclusions in brain matter of patients with CTE has made repetitive brain injury a possible environmental stimulus for aggregation in TDP-43 proteinopathies. We expand upon the hypothesis that TDP-43 readily aggregates under agitation conditions and that the addition of …

Development And Characterization Of An Inexpensive Single-Particle Fluorescence Spectrometer For Detection And Classification Of Pollen And Other Bioaerosols, Benjamin E. Swanson

Electronic Theses and Dissertations

Atmospheric aerosols are ubiquitous throughout the Earth’s atmosphere and can be important with respect to environmental systems and human health. Pollen particles are a class of primary biological aerosol particles (PBAPs) that cost the United States billions of dollars a year in loss of productivity and healthcare costs due to allergy and respiratory effects. Traditional methods of pollen detection rely on collection and subsequent identification by visual microscopy, yet few measurement stations exist in the United States. As such, current pollen forecasting models have relatively high prediction uncertainty, especially in regions without sampling stations. Recently, laser-induced fluorescence instrumentation has been …

The Changing Role Of Public-Private Partnerships In Urban Transportation: A Case Study Of The Rise Of P3s In Denver, Co, Sylvia Arriaga Brady

Electronic Theses and Dissertations

This research examines the expanding role of public-private partnerships (PPPs or P3s) in Denver metro transportation projects in three areas: (1) innovative funding and financing of transit infrastructure projects, (2) the partnerships between freight and passenger rail services, and (3) emerging collaborations of local governments, transit agencies, and transportation network companies (TNCs).

The purpose of the first study was to examine the recent use of P3s in the Denver Regional Transportation District's (RTD) FasTracks program, a 2004 voter-approved $4.7 billion transit expansion program. After a shortfall in funding, RTD partnered with several private consortia to enable the FasTracks program to …