Digital Commons Network^™

Conservation Of The Intracellular Bacterial Community Pathogenic Pathway In Urinary Tract Infection, David Rosen

All Theses and Dissertations (ETDs)

Urinary tract infections: UTIs) affect 13 million women annually in the United States. Uropathogenic Escherichia coli: UPEC) is the predominant etiologic agent of UTI; however, several other uropathogens, including Klebsiella pneumoniae, are also significant causative agents. In a murine cystitis model, UPEC utilize a multistep pathogenic pathway in which they invade and form intracellular bacterial communities: IBCs) within bladder facet cells. Type 1 pili, adhesive fimbriae, are necessary for UPEC binding and invasion of urothelial cells and formation of IBCs. UPEC ultimately disperse from the IBC, many with filamentous morphology, and proceed to infect other host urothelial cells. This work …

The Mechanisms And Roles Of Neural Feedback Loops For Visual Processing, Debajit Saha

All Theses and Dissertations (ETDs)

Feedback pathways are widely present in various sensory systems transmitting time-delayed and partly-processed information from higher to lower visual centers. Although feedback loops are abundant in visual systems, investigations focusing on the mechanisms and roles of feedback in terms of micro-circuitry and system dynamics have been largely ignored. Here, we investigate the cellular, synaptic and circuit level properties of a cholinergic isthmic neuron: Ipc) to understand the role of isthmotectal feedback loop in visual processing of red-ear turtles, Trachemys scripta elegans. Turtle isthmotectal complex contains two distinct nuclei, Ipc and Imc, which interact exclusively with the optic tectum, but are …

Structural And Functional Studies On Bk(Ca) Channels, Akansha Saxena

All Theses and Dissertations (ETDs)

The long term goal of this research is to study the structure and function of the BK_Ca channels, by focusing on the effect of a single residue mutation, the epilepsy mutation. BK_Ca channels are potassium channels, activated by voltage, Ca2+ and Mg2+ ions. These factors control the opening and closing of the channel pore and thus regulate the large K+ current passing through them. Recently, a mutation D434G in humans, was found to make the channel hyperactive and more sensitive to the Ca2+ ions. The single residue mutation, resulting from a substitution of an Asp to Gly, was …

Response Mapping In Evaluative Priming, Laura Scherer

All Theses and Dissertations (ETDs)

Recently, Scherer and Lambert: 2009) proposed a new model of priming, which they called the Response Mapping: RM) Model. That model assumes that under some circumstances, priming effects are the result of an unintentional tendency for participants to impose the target categorization task onto the primes: which they are supposed to ignore). In the present dissertation, the RM model is reviewed, and the implications and boundary conditions of the model are explored. In Experiments 1 and 2, it was predicted and found that response mapping processes can result in evaluative conditioning effects. That is, priming tasks do not always simply …

An Archaeological Model Of The Construction Of Monks Mound And Implications For The Development Of The Cahokian Society (800 - 1400 A.D.), Timothy Schilling

All Theses and Dissertations (ETDs)

This dissertation presents a model for the development of Cahokian society through the lens of monumental construction. Previous models of Cahokian society have emphasized the accumulation of individual power and domination of the many by a few. Using analogies from the ethnography and ethnohistory of Dhegian Siouan speakers, I argue the Cahokian system likely contained both achieved and ascribed statuses mediated through a worldview that emphasized balance and integration of the whole. In the face of a growing population, this kind of structural organization may have precluded the development of class conflict and, at the same time, permitted the development …

Implementation Of Hypertension Treatment Recommendations, Veronica Shead

All Theses and Dissertations (ETDs)

There are currently lifestyle modifications and medications that are highly successful in controlling hypertension. Nevertheless, many hypertensive individuals do not implement lifestyle changes and fail to adhere to medication regimens. The current study sought to understand both sociodemographic and intrinsic factors associated with the implementation of recommended lifestyle modifications for treatment of hypertension. The study represents the first step in the application of the Information-Motivation-Behavioral Skills: IMB) model of health behavior and health promotion to hypertension. The primary goal was to provide a profile of the variables relevant for adherence to the multifaceted treatment recommendations for the hypertensive population. 151 …

Adaptive Ofdm Radar For Target Detection And Tracking, Satyabrata Sen

All Theses and Dissertations (ETDs)

We develop algorithms to detect and track targets by employing a wideband orthogonal frequency division multiplexing: OFDM) radar signal. The frequency diversity of the OFDM signal improves the sensing performance since the scattering centers of a target resonate variably at different frequencies. In addition, being a wideband signal, OFDM improves the range resolution and provides spectral efficiency. We first design the spectrum of the OFDM signal to improve the radar's wideband ambiguity function. Our designed waveform enhances the range resolution and motivates us to use adaptive OFDM waveform in specific problems, such as the detection and tracking of targets. We …

The Ethics Of Forcible Democratization, David Speetzen

All Theses and Dissertations (ETDs)

Recent wars have led many to believe that the promotion of democracy cannot justify foreign intervention, but this is rash. A government's right to non-intervention should hinge on whether it adequately: 1) protects its subjects' human rights and: 2) represents their collective political will. I argue that when and where the international legal system's ability to enforce human rights matures and the social conditions for better representation emerge, the standards for adequate protection and representation should rise. Since democracy significantly augments both functions of government, eventually the right to non-intervention should depend on maintaining democratic institutions. Failure to do so …

Implicit And Explicit Racial Attitudes: Moderation Of Racial Typicality Evaluations, Elena Stepanova

All Theses and Dissertations (ETDs)

Previous research has shown that racial images representing more typical Afrocentric phenotypic characteristics result in more negative evaluations, whether assessed by explicit or implicit attitudes measures. However, the factors that define and moderate the perception of racial typicality have not been sufficiently explored. The current research investigated additive and interactive influences of skin tone and facial physiognomy on racial typicality evaluations, as well as the degree to which those effects were moderated by explicit and implicit racial attitudes, ethnicity of participants, and availability of cognitive resources. Using a 6-point scale ranging from very African American to very Caucasian, participants: N …

Examination Of Molecular Recognition In Protein-Ligand Interactions, Yat Tang

All Theses and Dissertations (ETDs)

This dissertation is a compilation of two main projects that were investigated during my thesis research. The first project was a prospective study which identified and characterized drug-like inhibitors of a prototype of bacterial two-component signal transduction response regulator using computational and experimental methods. The second project was the development and validation of a scoring function, PHOENIX, derived using high-resolution structures and calorimetry measurements to predict binding affinities of protein-ligand interactions. Collectively, my thesis research aimed to better understand the underlying driving forces and principles which govern molecular recognition and molecular design. A prospective study coupled computational predictions with experimental …

High-Speed Photoacoustic Microscopy In Vivo, Liang Song

All Theses and Dissertations (ETDs)

The overarching goal of this research is to develop a novel photoacoustic microscopy: PAM) technology capable of high-speed, high-resolution 3D imaging in vivo. PAM combines the advantages of optical absorption contrast and ultrasonic resolution for deep imaging beyond the quasi-ballistic regime. Its high sensitivity to optical absorption enables the imaging of important physiological parameters, such as hemoglobin concentration and oxygen saturation, which closely correlate with angiogenesis and hypermetabolism--two hallmarks of cancer. To translate PAM to the clinic, both high imaging speed and high spatial resolution are desired. With high spatial resolution, PAM can detect small structural and functional changes early; …

Role Of Fibroblast Growth Factor Signaling In Epicardial Development And Function, Mónica Vega-Hernández

All Theses and Dissertations (ETDs)

In this thesis I examined the function of Fibroblast Growth Factor: FGF) signaling in epicardial cells. Epicardial cells serve as the outer layer of the heart and as a signaling center for the growing myocardium. In addition, during development, epicardial cells differentiate into vascular smooth muscle cells: vsmc) and interstitial fibroblasts. Epicardial cells undergo an epicardial to mesenchymal transition: EMT) to give rise to these various cell types, which are termed epicardial derived cells: EPDCs). Epicardial-derived vsmc are an essential component of the arterial network in the myocardium, and the interstitial fibroblasts become part of the fibrous skeleton of the …

Accounting For Mysteries: Narratives Of Intuition And Empiricism In The Victorian Novel, Brooke Taylor

All Theses and Dissertations (ETDs)

This dissertation explores the tensions between an empirical epistemology and an intuitive method of knowing the world as depicted in popular Victorian novels. These narratives attempt to assimilate alternate modes of understanding; however, the uneasiness of the relationship between empiricism and intuition speaks to larger cultural tensions about the possibility of reconciling fact and feeling in the mid- to late-nineteenth century. I argue that intuitive and imaginative modes of cognition are continually privileged in novels that explicitly claim to adhere to empirical forms of knowledge. As I examine the work of Charles Dickens, Mary Elizabeth Braddon, Wilkie Collins, and George …

Proteomics Assisted Discovery Of Novel Proteins In Assembly And Regulation Of Photosystem Ii, Kimberly Wegener

All Theses and Dissertations (ETDs)

Cyanobacteria, the only prokaryotes capable of oxygenic photosynthesis, are present in diverse ecological niches and play crucial roles in global carbon and nitrogen cycles. To proliferate in nature, cyanobacteria utilize a host of stress responses to maintain photosynthesis under periodic changes in environmental conditions. Recent advances in proteomic study have enabled a systems-level analysis of cellular functions in many systems. Because proteins are directly responsible for cellular functions, measurements of protein abundances provide significant clues to the modulation of cellular functions during different environmental perturbations. A detailed knowledge of the composition of, as well as the dynamic changes in, the …

Pacemaker Heterogeneity In The Suprachiasmatic Nucleus: Origins And Network Implications, Alexis Webb

All Theses and Dissertations (ETDs)

In mammals, the suprachiasmatic nuclei: SCN) in the ventral hypothalamus function as a circadian pacemaker, controlling daily rhythms in behavior and physiology. Together the SCN contain approximately 20,000 neurons that maintain rhythms in firing rate and gene expression. Previous studies led to the assumption that single SCN neurons are capable of self-sustained circadian rhythms. Whether and which SCN neurons can maintain cell-autonomous daily oscillations has not been extensively tested. We measured PERIOD2::LUCIFERASE expression in isolated SCN neurons over multiple days to determine if all SCN neurons were circadian. We then examined neuropeptide content of the recorded neurons. We found that …

The Small Animals Of Maasai Settlements: Ethnoarchaeological Investigations Of The Commensalism Model, Lior Weissbrod

All Theses and Dissertations (ETDs)

This research was designed to test Tchernov's model of commensalism and the idea that remains of commensal species that today coexist with humans in settlement environments could be used to detect early sedentism in the archaeological record. The validity of the model has been questioned due to the lack of empirical knowledge on commensalism in a wide range of settlement environments including sedentary and more mobile ones. This study examined the commensalism model by focusing on seasonally occupied settlements of Maasai pastoralists in East Africa. Methods from ecology, ethnography, and archaeology were used to document the impact of Maasai settlements …

Abstractions And Algorithms For Control Of Extensible And Heterogeneous Virtualized Network Infrastructures, Charles Wiseman

All Theses and Dissertations (ETDs)

Virtualized network infrastructures are currently deployed in both research and commercial contexts. The complexity of the virtualization layer varies greatly in different deployments, ranging from cloud computing environments, to carrier Ethernet applications using stacked VLANs, to networking testbeds. In all of these cases, many users are sharing the resources of one provider and each user expects their resources to be isolated from all other users. There are many challenges associated with the control and management of these systems, including resource allocation and sharing, resource isolation, system security, and usability. Among the different types of virtualized infrastructures, network testbeds are of …

Structure And Function Of The Fmo Protein From The Photosynthetic Green Sulfur Bacteria, Jianzhong Wen

All Theses and Dissertations (ETDs)

The Fenna-Matthews-Olson: FMO) bacteriochlorophyll a protein has served as a model antenna system for understanding pigment-protein interaction and the energy transfer mechanism. The FMO protein has been extensively studied by a wide range of spectroscopic and theoretical techniques due to its stability, spectral resolution of pigments, water-soluble nature and availability of high-resolution structural information. A new 1.3 ├à FMO structure: PDB: 3EOJ) revealed an 8th pigment at the monomer connection region with partial occupancy. To understand the nature and stoichiometry of this new pigment, the molecular weight of the whole FMO complex was measured by the recently developed mass spectrometry: …

Frustrated Magnetism In Distorted Triangular Lattice Materials; & Extraordinary Electroconductance In Iii-V Metal Semiconductor Hybrid Structures, Jian Wu

All Theses and Dissertations (ETDs)

PART I: We have synthesized a series of spin S = 1/2 distorted triangular lattice materials Cu_2(1-x)Zn_2x(OH)₃NO₃and their long chain alkyl carboxylic group intercalated derivatives, Cu_2(1-x)Zn_2x(OH)₃(C₇H₁₅COO).mH₂O). Their structural properties, magnetic properties and specific heat have been carefully studied in this thesis. We found that antiferromagnetic-type long-range order develops in all the nitrate group compounds below the Neel temperatures T_N, which decreases with increasing Zn content. For the organic long chain intercalated samples, the temperature dependence of magnetic susceptibility …

Transient-State Kinetic Studies Of The Mechanisms Of Dna Unwinding And Translocation Of The E. Coli Recbc And Recbcd Helicases, Colin Wu

All Theses and Dissertations (ETDs)

This thesis presents mechanistic studies of the E. coli RecBC and RecBCD helicases using transient-state kinetic approaches to understand the relationship between DNA unwinding and ssDNA translocation. RecBC initiates unwinding from duplex DNA ends with pre-existing 5'-(dT)6 and 3'-(dT)6 ssDNA tails using a series of repeated rate-limiting steps with a rate of 345 ┬▒ 8 bp/sec and an average kinetic step-size of ~4 bp: 20 mM Mops-KOH, pH 7.0 at 25°C, 30 mM NaCl, 10 mM MgCl2, 5% glycerol, 1 mM 2-mercaptoethanol) while RecBCD unwinds these same DNA substrates with a rate of 745 ┬▒ 18 bp/sec using a more …

Organizational Processes Contribute To The Testing Effect In Free Recall, Franklin Zaromb

All Theses and Dissertations (ETDs)

In educational contexts, tests not only assess what students know, they can also directly improve long-term retention of subject matter relative to restudying it. More importantly, the memorial advantage of testing is not limited to select information that was tested earlier. Research has shown that testing can serve as a versatile learning tool by enhancing the long-term retention of non-tested information that is conceptually related to previously tested information; stimulating the subsequent learning of new information; and permitting better transfer of learning to new knowledge domains. We further investigated the potential benefits of testing on learning by asking whether testing …

A Free-Breathing Lung Motion Model, Tianyu Zhao

All Theses and Dissertations (ETDs)

Lung cancer has been the leading cause of cancer deaths for decades in the United States. Although radiotherapy is one of the most effective treatments, side effects from error in delivery of radiation due to organ motion during breathing remain a significant issue. To compensate the breathing motion during the treatment, a free breathing lung motion model, x= x0+αv+βf, was developed and discussed, where x is the position of a piece of tissue located at reference position x0. α is a parameter which characterizes the motion due to local air filling: motion as a function of tidal volume) and β …

Essays In Corporate Finance, Kangzhen Xie

All Theses and Dissertations (ETDs)

This dissertation studies the effects of information asymmetry, financial constraints and stock market valuation on the behavior of firms. The first essay explores the role of deal initiation and bidder asymmetry in determining the use of auction and target premia in merges and acquisitions. The second essay examines the behavior of the segments of conglomerates and single segment firms in the distressed industries. The third essay investigates the incentive of takeover arising from the temporary disparity of stock valuation. While half of all acquisition targets are sold in negotiated deals with only one buyer rather than by auction, the wealth …

Fcs Analysis Of Pore Formation By The Human Protein Bax In Lipid Membranes, Olena Ivashyna

All Theses and Dissertations (ETDs)

Bax is a pro-apoptotic member of the BCL-2 protein family and its paramount function during apoptosis is to form pores in the mitochondrial outer membrane: MOM). In a simplified apoptosis model, upon apoptotic stimulation, Bax is activated via an unresolved mechanism, translocates to the MOM, where it changes conformation, inserts into the membrane as a monomer, and finally undergoes in-membrane oligomerization to form a pore. Once the Bax pore is formed, cytochrome c and other mitochondria-resident proteins escape into the cytoplasm where they activate the cascade of caspases, which dismantle the cell. To date, the structure of the inactive cytoplasmic …

Whose Identity Is It Anyway? A Study Of The Media's Representation Of Iraq Citizens And Their Culture, Joyce L'Heureux

Open Access Master's Theses

What happens to our perceptions when provided with an invitation by news media, specifically print media, to accept what is presented as reality? Does what we read in the news media constrict our thinking and create an acceptance of the words as they are written, a type of cultural blindness to the qualities, the humanness and individuality of other cultures? Or, do we read the words on the paper and open our lens to create a greater understanding of individuals who differ from us in values, attitudes and beliefs? The truth is the same stories which provide us with an …

Relationship Between Psychosocial And Interpersonal Factors And Implicit Sex-Submission Associations In Hispanic/Latina And White Women, Myriel Rodríguez Boissén

Open Access Dissertations

The purpose of this study was to investigate implicit sex-submission associations for Hispanic /Latina and White women. Furthermore, this study examined how childhood sexual abuse, anticipated negative partner reaction-refusal, psychosexual functioning, sexual assertiveness-refusal and communication, and hyperfemininity are associated with women's implicit sex-submission associations. These interpersonal and psychosocial factors were analyzed for Hispanic/Latina and White women to help us determine if these associations are found for two different groups of women.

Previous research has demonstrated that individuals associate sex with power and aggression at an unconscious level (Bargh et al., 1995; Mussweiler & Forster, 2000; Zurbriggen, 2000). For men, implicit …

Studies Toward The Synthesis Of Lomaiviticins A And B And Englerin A, Srinivas Achanta

All Theses and Dissertations (ETDs)

Part I: Studies toward the central core of lomaiviticins A and B Lomaiviticins A and B are novel C2-symmetric dimeric molecules with profound cytotoxic activity. The most challenging feature of these molecules is the densely functionalized central core. Despite the effort by several research groups, the total synthesis of lomaiviticins has not been reported so far. We envisioned the synthesis of the lomaiviticin core by an unprecedented Diels-Alder dimerization of ortho-quinols and masked ortho-benzoquinones, followed by the fragmentation of the extra carbon-carbon bond. This chapter describes the stereoselective elaboration of the ortho-quinol and masked ortho-benzoquinone dimers to the fragmentation precursors …

Essays On Macro-Finance Relationships, Azamat Abdymomunov

All Theses and Dissertations (ETDs)

In my dissertation, I study relationships between macroeconomics and financial markets. In particular, I empirically investigate the links between key macroeconomic indicators, such as output, inflation, and the business cycle, and the pricing of financial assets. The dissertation comprises three essays. The first essay investigates how the entire term structure of interest rates is influenced by regime-shifts in monetary policy. To do so, we develop and estimate an arbitrage-free dynamic term-structure model which accounts for regime shifts in monetary policy, volatility, and the price of risk. Our results for U.S. data from 1985-2008 indicate that: i) the Fed's reaction to …

Physics Of Ultrasonic Wave Propagation In Bone And Heart Characterized Using Bayesian Parameter Estimation, Christian Anderson

All Theses and Dissertations (ETDs)

This Dissertation explores the physics underlying the propagation of ultrasonic waves in bone and in heart tissue through the use of Bayesian probability theory. Quantitative ultrasound is a noninvasive modality used for clinical detection, characterization, and evaluation of bone quality and cardiovascular disease. Approaches that extend the state of knowledge of the physics underpinning the interaction of ultrasound with inherently inhomogeneous and isotropic tissue have the potential to enhance its clinical utility. Simulations of fast and slow compressional wave propagation in cancellous bone were carried out to demonstrate the plausibility of a proposed explanation for the widely reported anomalous negative …

A Geometric Approach For Deciphering Protein Structure From Cryo-Em Volumes, Sasakthi Abeysinghe

All Theses and Dissertations (ETDs)

Electron Cryo-Microscopy or cryo-EM is an area that has received much attention in the recent past. Compared to the traditional methods of X-Ray Crystallography and NMR Spectroscopy, cryo-EM can be used to image much larger complexes, in many different conformations, and under a wide range of biochemical conditions. This is because it does not require the complex to be crystallisable. However, cryo-EM reconstructions are limited to intermediate resolutions, with the state-of-the-art being 3.6A, where secondary structure elements can be visually identified but not individual amino acid residues. This lack of atomic level resolution creates new computational challenges for protein structure …