Digital Commons Network^™

Light-Harvesting And The Primary Photochemistry Of Roseiflexus Castenholzii, Aaron Collins

All Theses and Dissertations (ETDs)

Photosynthetic organisms have evolved diverse antennas to harvest light of various qualities and intensities. Anoxygenic phototrophs can have bacteriochlorophyll Q_y antenna absorption bands ranging from about 700-1100 nm. This broad range of usable wavelengths has allowed many organisms to thrive in unique environments. Roseiflexus castenholzii is a niche-adapted, filamentous anoxygenic phototroph: FAP) that lacks chlorosomes, the dominant antenna found in all green bacteria. Light-harvesting is realized only in the membrane with BChl a and a variety of carotenoids. Through biochemical and spectroscopic methods, a model for the size and organization of the photosynthetic antenna is presented. Despite the wide …

The Staggered Chiral Perturbation Theory In The Two-Flavor Case And Su(2) Chiral Analysis Of The Milc Data, Xining Du

All Theses and Dissertations (ETDs)

As a part of the Standard Model: SM), Quantum Chromodynamics: QCD) is a widely accepted theory to describe the physics of quarks and gluons. Formulating QCD on finite discrete lattices in Euclidean space-time not only enables one to study the theory non-perturbatively, but also provides a framework analogous to statistical systems, in which numerical methods can be applied. In this work, we concentrate on one specific fermion formalism, staggered fermions. To interpret the data obtained from numerical simulations with staggered fermions, a particular version of chiral perturbation theory: χPT), rooted staggered χPT: rSχPT), is needed to incorporate the discretization effects, …

Development Of Atomistic Potentials For Silicate Materials And Coarse-Grained Simulation Of Self-Assembly At Surfaces, Brian Barnes

All Theses and Dissertations (ETDs)

This thesis is composed of two parts. The first is a study of evolutionary strategies for parametrization of empirical potentials, and their application in development of a charge-transfer potential for silica. An evolutionary strategy was meta-optimized for use in empirical potential parametrization, and a new charge-transfer empirical model was developed for use with isobaric-isothermal ensemble molecular dynamics simulations. The second is a study of thermodynamics and self-assembly in a particular class of athermal two-dimensional lattice models. The effects of shape on self-assembly and thermodynamics for polyominoes and tetrominoes were examined. Many interesting results were observed, including complex clustering, non-ideal mixing, …

Leveraged Buyouts, Long Term Relationship And Financial Contracting, Lei Gao

All Theses and Dissertations (ETDs)

In the first chapter of my dissertation, I study private equity sponsored leveraged buyouts. In this study, I identify and estimate two components of the created value: benefits of debt and influence of private equity. In the second chapter of my dissertation, I study repeated games with private monitoring in continuous time. I apply stochastic filtering theory to characterize the evolution of players' beliefs, which is difficult to do in discrete time. In the third chapter of my dissertation, I study the connection between financial contracting and staged financing in venture capital.

The Pursuit Of Accreditation In Children's Mental Health Care: Motivations, Experiences, And Perceptions, Madeline Lee

All Theses and Dissertations (ETDs)

Accreditation is a growing, worldwide phenomenon and thousands of mental health organizations spend considerable amounts of money and resources towards achieving and maintaining accreditation. Despite its widespread use, the empirical and theoretical literature on accreditation is sparse. This study is the first step towards examining accreditation's potential as an organizational intervention to improve the quality of mental health services. Using a mixed methods multiple case study design, this exploratory study aimed to 1) understand agencies' motivations to pursue accreditation, 2) explore agencies' experiences with the accreditation process, 3) identify mental health care workers' perceptions of how the accreditation process may …

Bodies Of Parchment: Representing The Passion And Reading Manuscripts In Late Medieval England, Sarah Noonan

All Theses and Dissertations (ETDs)

In a diverse range of late-fourteenth- and fifteenth-century devotional literature, Christ's body is metaphorically related to a book or a document at the moment of his crucifixion. His skin transforms into parchment, whips and scourges become pens, and a steady flow of blood, of ink, covers his body and the written page. And each word written onto his parchment body welcomes sustained study, acting as a potential meditative focal point for the devout reader. Through this metaphor and the accompanying materiality of the texts that include it, medieval authors and audiences could imagine intimately interacting with Christ's body during the …

Reducing False Hearing In The Elderly: Variability Training In Meta-Audition, Chad Rogers

All Theses and Dissertations (ETDs)

A large body of work supports the conclusion that older adults derive more benefit than young adults from the addition of contextual information in speech perception: Hutchinson, 1989; Pichora-Fuller, Schneider, & Daneman, 1995; Pichora-Fuller, 2008). More recent work by Rogers, Jacoby, and Sommers: in prep) showed that when contextual information and sensory information favored competing responses, older adults were more likely to falsely "hear" the word favored by context. The current research describes two experiments that attempt to mitigate this age-related increase on contextual reliance. Experiment 1 assessed whether the effects of context in Rogers, Jacoby, & Sommers: in prep) …

Thomas Hoccleve And The Poetics Of Reading, Elon Lang

All Theses and Dissertations (ETDs)

Thomas Hoccleve, the early fifteenth-century London poet who first promoted the notion that Chaucer was the father of English literature, demonstrates an acute awareness that readers would change the form of his own texts over time. Although many scholars consider Hoccleve's style to be derivative of his English predecessors, I argue that his awareness of readers contributed to an innovative style that casts writing and reading as mutually dependent acts of performance. Thus, in depictions of manuscript production and circulation processes, Hoccleve treats his audiences as his creative collaborators. The rich surviving manuscript history for Hoccleve reveals how his texts …

Exploring Tissue Microstructure In Healthy And Diseased Lung Tissue, Michelle Milne

All Theses and Dissertations (ETDs)

This thesis is divided into two parts. The first part examines diffusion in a number of human lung samples, while the second deals with diffusion in the more simplified environment of a single capillary tube. In the lung study we examine various types of lung samples: healthy and diseased) at a variety of diffusion lengths. Diffusion Magnetic Resonance Imaging: MRI) has been a very useful tool in the study of lungs and lung disease, particularly diffusion MRI using hyperpolarized gases, such as helium or xenon. However, since the polarized gas is difficult to prepare and, once prepared, suffers decay of …

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 …

Orientation-Specific Control Of Attention, Feng Du

All Theses and Dissertations (ETDs)

Previous studies have shown that an irrelevant distractor matched to a sought-for color captures attention involuntarily, thus violating either temporal or spatial control of attention. However, whether an irrelevant distractor that matches a sought-for orientation can capture attention is still unknown. A task of rapid serial visual presentation: RSVP) was developed to examine whether an irrelevant distractor oriented in the same way as the target can capture attention. Participants were presented with a sequence of letters at fixation and were required to search for the target letter with a specific orientation. In all five experiments, six peripheral bars flanked the …

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 …

Teaching News Literacy In The Age Of New Media: Why Secondary School Students Should Be Taught To Judge The Credibility Of The News They Consume, Elia Powers

All Theses and Dissertations (ETDs)

This paper involves two of the oldest institutions in America -- schools and the press -- and the preparation of informed citizens in the age of new media. I examine the manner and ways in which news literacy, the use of critical thinking skills to judge the reliability of news reports and news sources, is taught to secondary school students in the United States. It is axiomatic that a vigorous and independent press is critical to our democracy. Yet news literacy has not historically been included in the public school curriculum and continues to be widely absent, despite states vowing …

An Environment For Stroke Therapy Game Authoring, Simon Tam

All Theses and Dissertations (ETDs)

Stroke is the leading cause of disability in the industrialized world. The disabilities caused by stroke can significantly impact the quality of daily life for stroke survivors. Studies show that a high number of daily body movement repetitions can help recover lost motor functionality. However, many stroke patients do not perform the home exercises needed to reach this high number of repetitions. Games for rehabilitation have been shown to provide motivation to perform home exercises. However, because stroke can leave survivors with different levels of disability, custom games are required. Creating custom games, though, is time consuming and requires advanced …

A Study Of The Adjunct Faculty Experiences In The Creation Of A Teacher Work Sample, Anna L. Conway

Dissertations and Theses @ UNI

Part-time and adjunct faculty members have been present in institutions of higher learning since the founding of this country. These groups of faculty provide a variety of unique professional experiences to their students; they offer financial savings and scheduling flexibility for their colleges and on many levels, adjuncts offer a range of other valuable contributions to their institutions. The purpose of this study was to examine the experiences that community college adjunct faculty had with college teaching and implementation of the Teacher Work Sample. Another objective was to see how the completion of Teacher Work Sample contributed to the adjuncts' …

The Wisdom Of Crowds? Groupthink And Nonprofit Governance, Melanie B. Leslie

Articles

Scandals involving nonprofit boards and conflicts of interest continue to receive considerable public attention. Earlier this year, for example, musician Wyclef Jean's Yele Haiti charity became the target of intense criticism after the charity disclosed that it had regularly transacted business with Jean and entities controlled by Jean and other directors. Although scandals caused by self-dealing undermine public confidence in the charitable sector, they continue to erupt. Why do charitable boards sanction transactions with insiders?

This Article argues that much of the blame lies with the law itself. Because fiduciary duty law is currently structured as a set of fuzzy …

An Airloads Theory For Morphing Airfoils In Dynamic Stall With Experimental Correlation, Loren Ahaus

All Theses and Dissertations (ETDs)

Helicopter rotor blades frequently encounter dynamic stall during normal flight conditions, limiting the applicability of classical thin-airfoil theory at large angles of attack. Also, it is evident that because of the largely different conditions on the advancing and retreating sides of the rotor, future rotorcraft may incorporate dynamically morphing airfoils: trailing-edge flaps, dynamic camber, dynamic droop, etc.). Reduced-order aerodynamic models are needed for preliminary design and flight simulation. A unified model for predicting the airloads on a morphing airfoil in dynamic stall is presented, consisting of three components. First, a linear airloads theory allows for arbitrary airfoil deformations consistent with …

Envisioning Morality In Times Of Dynastic Change, Huan Jin

All Theses and Dissertations (ETDs)

The emphasis placed on morality became increasingly remarkable during late imperial China, especially at the junctures of dynastic change. This thesis explores the problem of the construction of morality, and I focus on two plays in which the idea of morality is presented in complicated ways: the late Yuan play Pipa ji τÉ╡τÉ╢Φ«░: The Lute) which primarily circulated during Ming and Qing Dynasties, and the early Qing play Taohua shan µíâΦè▒µëç: The Peach Blossom Fan) which deals with the late Ming period. In this thesis, I primarily treat these two plays as texts, and I try to answer how ideas …

Bayesian Multilevel Analysis Of Binary Time-Series Cross-Sectional Data In Political Economy, Xun Pang

All Theses and Dissertations (ETDs)

In this dissertation project, I propose a Bayesian generalized linear multilevel model with pth order autoregressive errors: GLMM-AR(p)) for modeling inter-temporal dependence, con-temporary correlation, and heterogeneity of unbalanced binary Time- Series Cross-Sectional data. The model includes two unnested sources of clustering in the unit- and time-dimensions for analyzing heterogeneities and contemporal corre- lation which are salient in the era of globalization. Group-level variations are further explained with unit- and time-specific characteristics. For handling dynamics in pol- itics and political economy, I apply the autoregressive error specification to analyze serial correlation which may not be fully captured by the selected covariates. …

Assessing Effects Of Symmetry On Motif Finding, Lala Motlhabi

All Theses and Dissertations (ETDs)

Identifying protein DNA binding sites like transcription factor binding sites is a key component of gene regulatory networks. The challenging task of predicting and identifying DNA binding sites both experimentally, and computationally suffers from high false positive due to various contributing factors, including misinterpretation of DNA binding site sequence symmetry. Our study seeks to model and compare the ability of three methods of a motif-finding program, consensus, taking into account orientation to accurately predict variable symmetric/asymmetric true binding site models. The three consensus methods included the c0 method which ignores the complement of a sequence. In this particular experiment it …

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 …

Determing The Properties Of Dense Matter: Superconductivity, Bulk Viscosity, And Light Reflection In Compact Stars, Gerald Good

All Theses and Dissertations (ETDs)

In this dissertation, we investigate the properties of matter, denser than nuclei, that exists inside compact stars. First, we examine a mixed superfluid/superconductor system, which likely occurs in neutron star cores. We derive an effective theory of Cooper pair quasiparticles from a microscopic theory of nucleons, and calculate the coupling strengths between quasiparticles. We then calculate the structure of magnetic flux tubes, taking into consideration interactions between neutron and proton Cooper pairs. We find that interactions between the condensates can lead to interesting phenomena and new phases at the border between type-I and type-II behavior. Next, we examine the response …

Brain Insulin Action Regulates Hypothalamic Glucose Sensing And The Counterregulatory Response To Hypoglycemia, Kelly Diggs-Andrews

All Theses and Dissertations (ETDs)

The brain is the primary organ that senses blood glucose levels and initiates a stress response when blood glucose levels are too low: hypoglycemia). Insulin-dependent people with Type 1 diabetes: T1DM) have an impaired ability to sense hypoglycemia and an impaired ability to activate this counterregulatory response: CRR) to hypoglycemia. As a result, T1DM are at a greater risk of experiencing insulin induced severe hypoglycemic episodes, which can result in seizures, brain damage, or even death. Since hypoglycemia is a major barrier that limits intensive blood glucose control, important research initiatives are needed to prevent or reduce the burden of …

Front End Specifications And The Propagation Of Construction Claims, Sidney Hymes

All Theses and Dissertations (ETDs)

Front End Specifications represent the administrative, organizational, performance and payment requirements for construction projects. The vast majority of construction contracts use Front End Specifications, either from an independent source or prepared in-house. In spite of the crucial role of Front End Specifications, little is known regarding whether Front End Specifications increase or decrease claims in construction. Further, no published reports to date have investigated whether construction claims are systematically related to Front End Specification complexity, partnering, business size or document authorship. In the present quantitative study, participants: n = 150) from the construction industry, including contractors, subcontractors, designers and owners, …

Mechanisms Of Copper Deficiency In The Zebrafish Embryo, Erik Madsen

All Theses and Dissertations (ETDs)

Proper maternal nutrition is critical for early embryonic development. Despite overwhelming epidemiologic data indicating the benefits nutrient supplementation for the developing organism we do not fully understand the genetics of predisposition to abnormal developmental phenotypes when faced with suboptimal nutrient levels. Copper is an essential nutrient required for critical biochemical processes. Severe defects in copper homeostasis lead to significant disease typified by the X-linked recessive disorder Menkes disease. Patients with Menkes disease have cutis laxa, bone deformities, hypopigmentation, arterial malformation, and neurodegeneration due to copper deficiency caused by loss-of-function mutations in ATP7A, a copper transport protein. Despite the critical requirement …

Dual-Modality Thermoacoustic And Photoacoustic Imaging, Manojit Pramanik

All Theses and Dissertations (ETDs)

Diagnosis of early breast cancer is the key to survival. The combined contrasts from thermoacoustic and photoacoustic tomography: TAT and PAT) can potentially predict early stage breast cancer. We have designed and engineered a breast imaging system integrating both thermoacoustic and photoacoustic imaging techniques to achieve dual-contrast: microwave and light absorption), non-ionizing, low-cost, high-resolution, three-dimensional breast imaging. We have also developed a novel concept of using a negative acoustic lens to increase the acceptance angle of an unfocused large-area ultrasonic transducer: detector), leading to more than twofold improvement of the tangential resolution in both TAT and PAT when the object …

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 …

Discovery And Identification Of New Dna Photoproducts And Investigation Of The Redox Mechanism Of Human Apurinic/Apyrimidinic Endonuclease 1 (Hape1) Protein, Dian Su

All Theses and Dissertations (ETDs)

Exposure of cells to ultraviolet light results in the formation of DNA photoproducts, many of which have been linked to skin cancer. The majority of these photoproducts arise from a photoreaction between two pyrimidines. Irradiation of double stranded B form DNA under physiological conditions mainly produces adjacent dimers. Nonadjacent photodimers of both intrastrand and interstrand types are much rarer. Intrastrand-type nonadjacent dimers form when one or more nucleotides between two pyrimidines become extrahelical owing to the formation of single strand DNA or a slipped structure. This allows the two pyrimidines to photodimerize in a colinear arrangement, as if the intervening …

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 …

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 …