Digital Commons Network^™

Cytotoxicity And Mutagenicity Of Disinfection Byproduct Mixtures Formulated Using Free Chlorine And Monochloramine, Yonas Ghebremedhin

Graduate Theses and Dissertations

Bioassays have been used extensively to assess various toxicity endpoints of drinking water disinfection byproducts (DBPs), but an emphasis on single compounds prevails. In this research, DBP mixtures were assessed using a cytotoxicity test with Chinese Hamster Ovary (CHO) cells and an Ames fluctuation test with Salmonella typhimurium TA-98 and TA-100 with and without S9 rat liver homogenate. Seven whole mixture DBP concentrates were formulated using reconstituted natural organic matter (NOM) extracts from the Upper Mississippi River using scaled disinfectant dosing protocols with free chlorine and monochloramine in the presence and absence of added bromide. DBPs were identified by gas …

Weigh-In-Motion Auto-Calibration Using Automatic Vehicle Identification, Fu Ren Zhang Zhang Durandal

Graduate Theses and Dissertations

Weigh-in-Motion (WIM) sensors are installed on mainline lanes at highway locations to record vehicle weights, axle spacing, vehicle class, travel speed, vehicle length, and traffic volume. These data elements support effective transportation planning, infrastructure design, and policy development. Therefore, it is important that WIM sensors supply accurate data. After initial installation and calibration, WIM systems may experience measurement drifts in weight and axle detection. Recalibration takes two general forms: (a) On-site calibration involving running trucks of known weight over WIM scales and (b) Auto-calibration methods involving comparisons to assumed reference weights. Auto-calibration can be more cost and time effective than …

Extracting Social Network From Literary Prose, Tarana Tasmin Bipasha

Graduate Theses and Dissertations

This thesis develops an approach to extract social networks from literary prose, namely, Jane Austen’s published novels from eighteenth- and nineteenth- century. Dialogue interaction plays a key role while we derive the networks, thus our technique relies upon our ability to determine when two characters are in conversation. Our process involves encoding plain literary text into the Text Encoding Initiative’s (TEI) XML format, character name identification, conversation and co-occurrence detection, and social network construction. Previous work in social network construction for literature have focused on drama, specifically manually TEI-encoded Shakespearean plays in which character interactions are much easier to track …

Turn That Frown Upside-Down! The Effectiveness Of Opposite Action In Changing Emotion, Kaitlyn Diane Chamberlain

Graduate Theses and Dissertations

While research demonstrates that opposite action (OA) impacts emotion (Rizvi & Linehan, 2005), we lack an understanding of the mechanisms by which it produces opposite emotions. The current study dismantled emotion regulation skill components by comparing tasks with different combinations of cognitive, emotive and behavioral components. I predicted that the OA condition would be the most effective in altering negative emotion. University students (n = 194) completed a sadness induction and were randomly assigned to either a (1) control, (2) low arousal positive imagery (3) high arousal positive imagery, or (4) OA plus high arousal positive imagery condition. The control …

Characterizing Hydrothermal System Groundwater Dynamics Using Conservative And Non-Conservative Tracers: Insights And Implications Drawn From Study At The Taupo Volcanic Zone (New Zealand) And Valles Caldera (Usa), Joshua Michael Blackstock

Graduate Theses and Dissertations

Hydrothermal systems constitute an important component of heat and mass transport within Earth’s crust having direct and indirect impacts to society. Investigating contemporary hydrochemical differences and change are critical to evaluating and deconvolving factors that influence geothermal systems through time. In this dissertation, groundwater mixing approaches were used to study hydrochemical differences in two globally significant hydrothermal areas, which included fabrication of a low-cost dissolved CO2 monitoring for dissolved inorganic carbon (DIC). In the Taupo Volcanic Zone (New Zealand), empirical spatial relations were used to derive low-temperature groundwater end-members of Cl and Cl/Br for end-member mixing analysis (EMMA). Using EMMA, …

The Feedback-Related Negativity Is A Time-Dependent Brain Mechanism That Facilitates Aversive Learning: Implications For The Reinforcement Learning Frn Hypothesis, Eric Rawls

Graduate Theses and Dissertations

Organisms encode rewarding and aversive experiences through reinforcement learning, capitalizing on prediction errors (PEs), which adapt action strategies over time. Computational theories are explicit that PE signals should update action weights continuously over the course of a behavioral task, an important time-dependent variation that is eschewed in traditional neuroscience studies that average over large numbers of trials. I examined variation in reaction times and feedback-locked cortical activity over time as a function of PE to critically examine theories indicating that PE signals drive time-dependent learning. We recorded EEG while participants completed a novel reinforcement task that varied prediction error on …

Interfacial Contact With Noble Metal - Noble Metal And Noble Metal - 2d Semiconductor Nanostructures Enhance Optical Activity, Ricardo Raphael Lopez Romo

Graduate Theses and Dissertations

Noble metal nanoparticles and two-dimensional (2D) transition metal dichalcogenide (TMD) crystals offer unique optical and electronic properties that include strong exciton binding, spin-orbital coupling, and localized surface plasmon resonance. Controlling these properties at high spatiotemporal resolution can support emerging optoelectronic coupling and enhanced optical features. Excitation dynamics of these optical properties on physicochemically bonded mono- and few-layer TMD crystals with metal nanocrystals and two overlapping spherical metal nanocrystals were examined by concurrently (i) DDA simulations and (ii) far-field optical transmission UV-vis spectroscopic measurements. Initially, a novel and scalable method to unsettle van der Waals bonds in bulk TMDs to prepare …

Exploring Convergence Of Snake Skin-Inspired Texture Designs And Additive Manufacturing For Mechanical Traction, Catherine Sue Tiner

Graduate Theses and Dissertations

This research focuses on the understanding, development, and additive manufacture of a 3D printed snake skin-inspired texture pattern. The design functionalities of snake skin were determined through the study of the snake species Python Regius otherwise known as the ball python. Each scale of a snake has hierarchical texture with hexagonal macro-patterns aligned on the ventral surface of the skin with overriding anisotropic micro textured patterns such as denticulations and fibrils. Using a laser-powder bed fusion (L-PBF) process, 420 stainless steel samples were 3D printed which closely resemble the above described directional texture of natural snake skin. This printed surface …

Observable Persistent Effects Of Habitat Management Efforts In The Ozark Highlands After 10 Years, Maxwell Carnes-Mason

Graduate Theses and Dissertations

I investigated the lasting impacts of a management plan designed to improve oak regeneration and benefit wildlife in the Ozark Highlands in Madison, Co., AR. To assess the efficacy of the management plan, I used variables relevant to the success and establishment of oak trees. Controlled burns and selective logging were used to thin the canopy, increase ground level productivity, and increase the abundance of small mammals. I used measurements of overstory and understory densities, light availability, and the density of mice in the genus Peromyscus across time to look at the lasting impacts of management. Different treatment plots were …

Influence Of Single And Multiple Histidine Residues And Their Ionization Properties On Transmembrane Helix Dynamics, Orientations And Fraying, Fahmida Afrose

Graduate Theses and Dissertations

Since aromatic and charged residues are often present in various locations of transmembrane helices of integral membrane proteins, their impacts on the molecular properties of transmembrane proteins and their interactions with lipids are of particular interest in many studies. In this work, I used solid-state deuterium NMR spectroscopy in designed model peptide GWALP23 [GGALW(LA)6LWLAGA] with selective deuterium labels to addresses the pH dependence and influence of single and multiple “guest” histidine residues in the orientation and dynamic behaviors of transmembrane proteins. The mutations include Gly to His (G2/22 to H2/22), Trp to His (W5/19 to H5/19) and Leu to His …

Investigating Egg Storage Conditions, Hatch Characteristics, And Feeding Methods Of Commercially Produced Poultry, Joshua R. Deines

Graduate Theses and Dissertations

Advancements in poultry research continue to add knowledge and understanding to an already technical industry. Such information has led to new developments in early feeding strategies which provide nutrients to broiler chicks while in the egg or during transport. This wealth of knowledge in poultry research extends beyond chickens and is utilized for other species, such as quail and pheasants, including how fertile eggs are stored and incubated. However, methods of early feeding broilers have not been investigated in industry relevant approaches to understand its effects, including how timing of feed access interacts with the hatch window. As well, quail …

Single Molecule Fluorescence Studies Of Protein Structure And Dynamics Underlying The Chloroplast Signal Recognition Particle Targeting Pathway, Dustin R. Baucom

Graduate Theses and Dissertations

The work presented in this dissertation explores the structural dynamics in the chloroplast signal recognition particle pathway. Findings include cpSRP shows scanning functionality similar to that in the cytosolic SRP with the ribosome. The intrinsically disordered C-terminal tail of the Albino3 protein has some transient secondary structure. Upon binding to cpSRP43 in solution, separate secondary structure formation was identified in the C-terminal tail of Albino3. Finally, to increase efficiency of analyzing fluorescence time traces for this work, a modular software was produced.

Evaluation And Analysis Of Null Convention Logic Circuits, John Davis Brady

Graduate Theses and Dissertations

Integrated circuit (IC) designers face many challenges in utilizing state-of-the-art technology nodes, such as the increased effects of process variation on timing analysis and heterogeneous multi-die architectures that span across multiple technologies while simultaneously increasing performance and decreasing power consumption. These challenges provide opportunity for utilization of asynchronous design paradigms due to their inherent flexibility and robustness.

While NULL Convention Logic (NCL) has been implemented in a variety of applications, current literature does not fully encompass the intricacies of NCL power performance across a variety of applications, technology nodes, circuit scale, and voltage scaling, thereby preventing further adoption and utilization …

The Rise Of Anti-Immigration Populist Radical Right Parties: The Effect Of The Syrian Conflict On Refugee Resettlement And Migration Policies In Germany And Austria, Sara Kouchehbagh

Graduate Theses and Dissertations

The effects of Syrian migration in Europe have revolutionized refugee resettlement globally. Most immigration and refugee problems have historically been settled similarly post WWII, however, Syria is the largest refugee crisis since WWII. It is important to learn how to respond to future conflicts with displacement and resettlement affecting Western countries that are unprepared to respond to a conflict of such magnitude. This thesis will compare previous conflicts and the Syrian conflict, while highlighting the resilient political momentum of reactionary new political groups in European states, particularly Germany and Austria.

The research and results from this study will include data …

Estimation Of Genetic Components Related To Infectious Bovine Keratoconjunctivitis Susceptibility In Angus And Angus Derived Cattle Produced In The Southern United States, Eric Oxford

Graduate Theses and Dissertations

The economic impact of infectious bovine keratoconjunctivitis (IBK) has been documented in many parts of the world. Many researchers have observed that prevention of this disease is very difficult given current methodologies. This is primarily due to the multifactorial nature of this disease. The objective of this dissertation was to determine the impact of IBK on calf performance and estimate genetic parameters, heritability and estimated breeding values for IBK susceptibility. Data were analyzed using PROC GLIMMIX of SAS; while genetic parameters were estimated using a linear animal model for both single- and two-traits through MTDFREML. Additional evaluations calculated heritability using …

A Geospatial Analysis Of Safety And Risk Perception In The Buffalo National River, Julie Nicole Terhune

Graduate Theses and Dissertations

In 1972, the Buffalo River in Arkansas became America’s First National River. Since then, the Buffalo National River has become a beloved recreational retreat for locals and visitors alike. The Buffalo National River is home to incredibly scenic views and host to many outdoor activities, among them, hiking and floating. As with any confluence of nature and humans, there is great risk involved in all aspects of the park. Between 2011 and 2017, a total of 140 search and rescue missions were carried out. Some were resolved easily, but more serious accidents were not unheard of.

Risk perception studies are …

Suitability Assessment For Integrated Urban Development In Makkah City Of Saudi Arabia, Mislat Alotaibi

Graduate Theses and Dissertations

Makkah – the third most populated city in Saudi Arabia with a population of 1,684,408 according to the 2010 demographic survey conducted by the Saudi General Authority for Statistics – is experiencing urban sprawl, which can be defined as an unplanned urban expansion that might degrade the environment and diminish the aesthetic view. This is a persisting problem in Makkah driven by multitude of processes involving the random expansion in its undeveloped land and the removal of its historic mountains surrounding Al-Masjid Al-Haram (the Holy Mosque) in an attempt to push the city limit of urban capacity within its administrative …

Retaining Special Education Teachers In A Rural Arkansas School District, Eric Ryan Gotte

Graduate Theses and Dissertations

According to published research, rural school districts across the United States are challenged with obstacles in recruiting and retaining special education teachers. This study presents findings based on special education teachers’ experiences teaching within one rural Arkansas school district. This instrumental single case study investigates the factors that encourage special education teachers to remain in their current position within a rural Arkansas school district. Qualitative data is analyzed from 11 participants, 9 current special educators, 1 special education director, and 1 retired special education teacher. All of the participants are from one rural Arkansas school district in order to gain …

Quantitative Study Of The Antimicrobial Effects Of Silver On The Motility Of Escherichia Coli, Benjamin Russell

Graduate Theses and Dissertations

In recent decades, the number of antibiotic-resistant bacterial infections has grown to become a serious global threat. This rise can be attributed to the widespread misuse of antibiotics and the lack of newly developed drugs to fight resistant organisms. Novel bactericidal substances have, therefore, garnered significant research interest. Silver, due to its powerful antimicrobial effects, is one such substance. Silver is typically most effective in cationic form; however, advancements in nanotechnology have paved the way for the controlled fabrication of nano-silver. Silver nanoparticles have been shown to have increased antibacterial potency for a variety of reasons, including the release of …

The Van Hiele Analysis Of Curricular Materials: A Comparative Study, Vinay Kumar Kalyankar

Graduate Theses and Dissertations

The goal of this study is to investigate K-8 geometry curriculum standards and textbooks for their effectiveness in preparing students for high school geometry. The basis for the study is van Hiele theory pioneered by the Dutch educators and researchers of geometric understanding in adolescents, Dina van Hiele Geldof and Pierre van Hiele. Another driving force for this dissertation is research into mathematics textbooks and curriculum standards of school mathematics as seen in CCSSM and state specific standards documents, both of which influence the mathematics students have the opportunity to learn.

The K-8 geometry curriculum standards and textbook instructional segments …

Strategies To Improve Forage Utilization By Sheep Offered Forage Mixtures, Valens Niyigena

Graduate Theses and Dissertations

In the first experiment, alfalfa and novel endophyte-infected tall fescue (NE+) forages were harvested after a killing frost, then mixed to formulate 4 different treatments; alfalfa alone, 67% alfalfa +33% fescue, 33% alfalfa + 67% fescue, or 100% fescue. After 3 months of storage as silage, Dorper ewe lambs (n = 20; mean BW = 34.7 ± 6.65 kg) were fed silage for ad libitum consumption, using 5 animals per treatment. Increasing the proportion of NE+ tall fescue improved (P < 0.05) silage total acids and lactic acid concentrations and decreased silage ammonia concentration. Digestible dry matter and organic matter intake and nitrogen utilization parameters decreased with increasing inclusion of NE+ in diet. In the second experiment, 16 Dorper ewe lambs (41.8 ± 4.61 kg BW) were assigned to 4 different treatments; alfalfa silage alone (0 g/kg; CONT) or alfalfa silage mixed with chopped sericea lespedeza (SL) hay to provide 90 (LOW), 180 (MED), or 270 g/kg SL (HIGH) on a dry matter basis in a randomized complete block design experiment with 2 period to provide 4 observations per treatment for each experimental period. Increasing the proportion of sericea lespedeza in the diet decreased dry matter and organic matter digestibility but did not affect feed intake. Fecal nitrogen (g/kg N intake) increased linearly (P < 0.01) while urinary N (g/ day and g/ kg of N intake) tended to decreased linearly and quadratically (P ≤ 0.1) with increasing the proportion of SL in diet. In the third experiments, 16 gestating Dorper ewe lambs (49.1 ± 4.61 kg BW) were allocated to 4 treatments; alfalfa silage alone (0% g/kg; CONT) or alfalfa silage mixed with lablab purpureus(LP) hay to provide 90 (LOW), 180 (MED), or 270 g/kg LP (HIGH) on a dry matter (DM) basis, in a randomized complete block design experiment with a total 8 replication per treatment. Supplementation of LP in diet increased quadratically (P ≤ 0.04) forage dry matter, organic matter intake, digestible dry matter and digestible organic matter intake (P < 0.05). Nitrogen apparently absorbed and urinary N both decreased linearly (P < 0.01) with adding more LP hay in diet. Harvesting and mixing alfalfa and fescue after a killing frost improved silage fermentation characteristics and supplementation of tannins from SL and polyphenol from LP altered N excretion.

Key words: lablab, sericea lespedeza, alfalfa silage, nitrogen, sheep.

Contrasting Geometric Variations Of Mathematical Models Of Self-Assembling Systems, Michael Sharp

Graduate Theses and Dissertations

Self-assembly is the process by which complex systems are formed and behave due to the interactions of relatively simple units. In this thesis, we explore multiple augmentations of well known models of self-assembly to gain a better understanding of the roles that geometry and space play in their dynamics. We begin in the abstract Tile Assembly Model (aTAM) with some examples and a brief survey of previous results to provide a foundation. We then introduce the Geometric Thermodynamic Binding Network model, a model that focuses on the thermodynamic stability of its systems while utilizing geometrically rigid components (dissimilar to other …

Changes In Cortical Processing Following Unilateral Visual Cortex Deafferentation, Matthew Gannon

Graduate Theses and Dissertations

After the loss of inputs, cells in visual cortex adapt and begin representing space beyond their classical receptive fields. This ability for functional reorganization is a phenomenon known as neuroplasticity. Homonymous hemianopia is a unique case of this scenario that results from hemispheric deafferentation, or when all visual inputs in to one hemisphere of the brain are lost. This condition occurs due to unilateral damage of the post-chiasmatic geniculo-striate pathway, the network that carries visual information from one side of visual space to the visual cortex for processing. Damage to this pathway causes perceptual blindness in the side of space …

In Vivo Metabolic And Vascular Response To Hypoxia In Twist Knockdown Murine Breast Cancer, Brandon Sturgill

Graduate Theses and Dissertations

Twist transcription factor is often overexpressed in aggressive tumors. Although needed in early embryonic development for organogenesis, Twist is known to induce an epithelial to mesenchymal transition in cells. In cancer, epithelial to mesenchymal transitions can lead to increased motility and invasiveness. It has also been linked to metabolic reprogramming and increased metastatic risk. Furthermore, metabolic preferences can increase proliferation, enhance metastatic potential, and influence the site of metastasis. We hypothesize that Twist directly affects the metabolism of cancer cells. We expect to see in vivo what we have seen in vitro; Twist overexpression should promote a shift away from …

An Evaluative Framework For The Improvement Of Religious Practice In The Context Of Pluralism, Benjamin Ford Dardas

Graduate Theses and Dissertations

Pluralism presents a troubling epistemic problem in that the inability to determine whether or not significant portions of a given religion’s cosmological and metaphysical belief set actually correspond to reality. Within this standstill there seems to be no way to prove yet alone maximize the epistemic rationality of continued religious practice, as each religion will claim to have a unique source of knowledge the others do not. However, if we set aside these unverifiable disputes, there remains an often underemphasized common thread: religions each have a conception of how this world ought to be. These conceptions involve how members of …

A Case Study On The Differences In Scores Of Undergraduate Students In Traditional, Online, And Hybrid Classes, Patricia Ruth Kuhn

Graduate Theses and Dissertations

The primary purpose of this research was to ascertain whether there are variances in academic performance between students taking an educational technology course in traditional, online, and hybrid learning environments. As a secondary goal, the study assessed the differences in academic performance of male and female students in these classes.

All students in this study held an undergraduate status of junior or above. They had earned a minimum of 45 hours and had a minimum 2.75 overall GPA. These students also passed the certification test for state educators and had been accepted as teacher candidates of the College of Education …

Adaptive Boundary Control Using The Natural Switching Surfaces For Flyback Converters, Luciano Andres Garcia Rodriguez

Graduate Theses and Dissertations

The derivation and implementation of the natural switching surfaces (NSS) considering certain parametric uncertainties for a flyback converter operating in the boundary conduction mode (BCM) is the main focus of this paper. The NSS with nominal parameters presents many benefits for the control of nonlinear systems; for example, fast transient response under load-changing conditions. However, the performance worsens considerably when the converter actual parameters are different from the ones used in the design process. Therefore, a novel control strategy for NSS considering the effects of parameter uncertainties is proposed. This control law can estimate and adapt the control trajectories in …

Countering Cybersecurity Vulnerabilities In The Power System, Fengli Zhang

Graduate Theses and Dissertations

Security vulnerabilities in software pose an important threat to power grid security, which can be exploited by attackers if not properly addressed. Every month, many vulnerabilities are discovered and all the vulnerabilities must be remediated in a timely manner to reduce the chance of being exploited by attackers. In current practice, security operators have to manually analyze each vulnerability present in their assets and determine the remediation actions in a short time period, which involves a tremendous amount of human resources for electric utilities. To solve this problem, we propose a machine learning-based automation framework to automate vulnerability analysis and …

Functional Importance Of Lipin Phosphorylation, Stephanie Elizabeth Hood

Graduate Theses and Dissertations

Highly conserved throughout evolution, lipins are dual functioning proteins found from yeast to humans. Functioning in the cytoplasm as phosphatidate phosphatase enzymes (PAP), lipins produce diacylglycerol that serves as a precursor for neutral fats and membrane phospholipids. Alternatively, nuclear lipins are responsible for the regulation of metabolic genes. Interestingly, both the mammalian lipin 1 paralog and the single Drosophila Lipin ortholog are highly phosphorylated proteins. Target of rapamycin (TOR) has previously been identified as one of the kinases that controls the subcellular localization of both lipin 1 and Drosophila Lipin. However, other serine and threonine kinases are predicted to be …

Toward Understanding The Mechanism Of Protein Targeting In The Chloroplast Signal Recognition Particle Pathway, Mercede Furr

Graduate Theses and Dissertations

Protein targeting is a vital cellular function. The signal recognition particle (SRP) pathway is a universally conserved targeting system present in the cytosol and used to co-translationally target many proteins to the inner membrane of prokaryotes and the endoplasmic reticulum of eukaryotes. The chloroplast has a homologous SRP system which post-translationally targets light harvesting chlorophyll binding proteins (LHCPs) to the thylakoid membrane for integration. The chloroplast SRP (cpSRP) is a heterodimer with a 54 kDa subunit equivalent to SRP54 in the canonical pathway. In addition, cpSRP contains a novel 43 kDa subunit which is a unique and irreplaceable component. cpSRP43 …