Digital Commons Network^™

Trend Analysis Of Water Quality In Northwest Arkansas Streams Reflects Changes In The Watershed, Zachary Paul Simpson

Graduate Theses and Dissertations

Watershed export of nutrients, sediments, and chemicals impacts receiving waters. Changes within the watershed (e.g., anthropogenic or climatic) can alter the transport of constituents in streams. Stream monitoring is crucial for understanding these effects. This study developed a potential improvement to flow-adjusting constituent concentrations in streams, an important step of analyzing monitoring data in lotic systems for trends. The method incorporates a K-fold cross-validation procedure to optimize a model explaining the relationship between the concentration and streamflow, thus providing a valuable tool to researchers in water quality. Additionally, two case studies were conducted on watersheds located in northwest Arkansas using …

Biocentrism In Environmental Ethics: Questions Of Inherent Worth, Etiology, And Teleofunctional Interests, David Lewis Rice Iii

Graduate Theses and Dissertations

Some biocentrists argue that all living things have "inherent worth". Anything that has inherent worth has interests that provide a reason for why all moral agents should care about it in and of itself. There are, however, some difficulties for biocentric individualist arguments which claim that all living things have inherent worth.

Some biocentrists maintain that all living things have inherent worth and that artificial living things do not because the former, but not the latter, have interests by recourse to their natural selection etiology. Some also argue that synthetic forms of life do not have moral standing because they …

Assessment Of The Level Of Protection Against Coccidiosis In Broiler Breeders Conferred By A Live Anticoccidial Vaccine, And Its Influence On Early Growth And Development., Muhammed Shameer Abdul Rasheed

Graduate Theses and Dissertations

Coccidiosis continues to be a great challenge to the poultry industry all over the world and in broiler breeders vaccination with live oocysts of Eimeria has been widely adopted as a control measure. Broiler breeders are usually subjected to feed restriction during their early growth however no studies have been undertaken on the effects of vaccination in birds whose feed has been restricted in this manner. The objective of this study was to assess the level of protection acquired by broiler breeder chickens when immunized at day-old with live eimerian oocysts and given a restricted diet. Effects upon growth and …

Effect Of Hydration Status On Thermoregulatory Responses In Non-Obese And Obese Males, Matthew Tucker

Graduate Theses and Dissertations

During heat stress the human body thermoregulates via cutaneous vasodilation and sweating. Hypohydration can impair thermoregulatory responses that stem from the central nervous system (CNS), but it is unknown if impairments also occur post-synaptically in the microcirculation. Moreover, obese individuals may have impaired thermoregulation, possibly due to microvascular dysfunction. Purpose: The purpose of these studies was two-fold: 1) to determine if obese (OB) individuals exhibit impairments in thermoregulatory responses during exercise heat-stress (centrally-mediated) and intradermal infusion of vasoactive substances (peripherally-mediated) versus non-obese (N-OB), and 2) to determine if hypohydration subsequently affects these thermoregulatory responses differently between groups. Methods: Twenty-one healthy, …

An Investigation Of Short-Term Plasticity In Human Motor Cortex, Matthew Alan Gannon

Graduate Theses and Dissertations

Transcranial magnetic stimulation (TMS) produces a transient magnetic field that activates underlying cortical tissue by eliciting an electrical discharge of the neurons in the targeted area. Repetitive TMS (rTMS) uses patterns of repetitive TMS pulses and has been reliably shown to produce changes in the state of cortical excitability outlasting the time of stimulation. One such protocol that has demonstrated states of increased excitability is intermittent theta burst stimulation (iTBS). This method applies high-frequency bursts (50Hz) of pulses every 200 ms in trains of ten bursts. The effects of and differences between rTMS protocols have been investigated since gaining popularity …

Design And Analysis Of An Asynchronous Microcontroller, Michael Hinds

Graduate Theses and Dissertations

This dissertation presents the design of the most complex MTNCL circuit to date. A fully functional MTNCL MSP430 microcontroller is designed and benchmarked against an open source synchronous MSP430. The designs are compared in terms of area, active energy, and leakage energy. Techniques to reduce MTNCL pipeline activity and improve MTNCL register file area and power consumption are introduced. The results show the MTNCL design to have superior leakage power characteristics. The area and active energy comparisons highlight the need for better MTNCL logic synthesis techniques.

Asynchronous Data Processing Platforms For Energy Efficiency, Performance, And Scalability, Liang Men

Graduate Theses and Dissertations

The global technology revolution is changing the integrated circuit industry from the one driven by performance to the one driven by energy, scalability and more-balanced design goals. Without clock-related issues, asynchronous circuits enable further design tradeoffs and in operation adaptive adjustments for energy efficiency. This dissertation work presents the design methodology of the asynchronous circuit using NULL Convention Logic (NCL) and multi-threshold CMOS techniques for energy efficiency and throughput optimization in digital signal processing circuits. Parallel homogeneous and heterogeneous platforms implementing adaptive dynamic voltage scaling (DVS) based on the observation of system fullness and workload prediction are developed for balanced …

Audit-Related Services And Audit Quality: Evidence From Benefit Plan Audits, Jaclyn Prentice

Graduate Theses and Dissertations

The following study examines a material but less understood component of the public audit marketplace, namely the provision of “audit-related” services to financial statement audit clients. I use the benefit plan audit service setting to examine the company and benefit plan characteristics associated with auditor selection and the impact of audit-related services on financial statement audit quality. I provide market evidence of distinct shifts in the use of the same audit firm for the financial statement audit and other audit-related services over time as well as characteristics of the choice of auditors. I then test whether having the same audit …

Two-Electron Quenching Of Dinuclear Ruthenium(Ii) Polypyridyl Complexes, Yinling Zhang

Graduate Theses and Dissertations

A bridging ligand 5,5’-Bi- 1,10-phenanthroline, diphen, was prepared using dichlorobis(triphenylphosphine)Ni(II), Ni(PPh3)2Cl2 as catalyst with a yield of 40%. Yellow cubic crystals were able to obtain from the good purity product for single crystal analysis. The torsion angle between the planes of the subunit phenanthrolines is about 66 degrees.

A dinuclear ruthenium (II) polypyridyl complex, (phen)2Ru(diphen)Ru(phen)24+, was synthesized by using polymeric ruthenium carbonyl compound as the entry point, diphen as the bridging ligand and 1,10-phenanthroline, phen, as the terminal legand. Brown needlelike crystals were precipitated from acetonitrile that were not suitable for single crystal diffraction.

The photochemistry of the dimer was …

Evaluating A Measure-Calculate Method For Determining Sediment Oxygen Demand In Lakes, Adrian Beirise

Graduate Theses and Dissertations

A steady-state mass diffusion model used with simple measurable and calculable inputs for determining sediment oxygen demand (SOD) is compared to an intact core incubation (ICI) SOD method using samples from three lakes. The mass diffusion model coupled with inputs is known as the measure-calculate method (M-C) and is a potential alternative to existing methods for measuring SOD which are more complex, time-consuming, and costly. The M-C method requires inputs for volumetric sediment oxygen uptake (Ṅsed), sediment density and porosity, and water properties. Ṅsed was determined by suspending sediment in oxygen-saturated water with a DO probe and determining the steady …

The Influence Of Strength-Training Exercises On The Functional Fitness In Older Adults, Susie Engle

Graduate Theses and Dissertations

The purpose of this study was to examine the influence of strength-training exercises on the functional fitness in older adults. The original convenience sample consisted of 658 participants who attended group strength-training classes offered through the Cooperative Extension Service. The Senior Fitness Test was used to assess baseline fitness levels at the beginning and end of the 12-week strength-training program. Data was collected from 2008 to 2015. Of the 658 participants, 110 were aged 60 to 94 and presented posttest scores occurring approximately 12 weeks after pretest dates. Of the 110 subjects, 99 were female and 11 were male. The …

Study Of Plasmonic Properties Of The Gold Nanorods In The Visible To Near Infrared Light Regime, Pijush Kanti Ghosh

Graduate Theses and Dissertations

Nanostructures of noble metals show unique plasmonic behavior in the visible to near-infrared light range. Gold nanostructures exhibit a particularly strong plasmonic response for these wavelengths of light. In this study we have investigated optical enhancement and absorption of gold nanorods with different thickness using finite element method simulations. This study reports on the resonance wavelength of the sharp-corner and round-corner rectangles of constant length 100 nm and width 60 nm. The result shows that resonance wavelength depends on the polarization of the incident light; there also exists a strong dependence of the optical enhancement and absorption on the thickness …

Culinary Competence: Skills And Knowledge Assessment For Dietetic Students, Nancy Harris Buckley

Graduate Theses and Dissertations

Graduates of didactic programs in dietetics are entering internships with little cooking experience. The Food and Culinary Professionals’ Dietetic Practice Group (FCP DPG) has identified 11 core competencies that were developed as a recommendation to dietetic educators to include more culinary knowledge into existing programs. The purpose of this study was to determine if developing and incorporating experiential learning targeted to the competencies would increase dietetic students’ culinary skills and knowledge at a southern land-grant university. Food and Culinary Professionals’ DGP core competencies were used to guide the development of curriculum, experiential learning, and assessment in the Principles of Foods …

Conformally Invariant Operators In Higher Spin Spaces, Chao Ding

Graduate Theses and Dissertations

In this dissertation, we complete the work of constructing arbitrary order conformally invariant operators in higher spin spaces, where functions take values in irreducible representations of Spin groups. We provide explicit formulas for them.

We first construct the Dirac operator and Rarita-Schwinger operator as Stein Weiss type operators. This motivates us to consider representation theory in higher spin spaces. We provide corrections to the proof of conformal invariance of the Rarita-Schwinger operator in [15]. With the techniques used in the second order case [7, 18], we construct conformally invariant differential operators of arbitrary order with the target space being degree-1 …

The Juvenile Addiction Risk Rating For Use In Vocational Rehabilitation, Paul Tyler Hickerson

Graduate Theses and Dissertations

The prevalence of substance use among adolescents warrants considerable concern since it often has detrimental effects on an individual’s physical and mental health, and correlates with worsened Social, physical, and employment outcomes. Research shows that adolescents with disabilities are especially susceptible to the development of substance use disorders. To address this concern and to ensure accurate rehabilitation service planning, effective screening for substance use risk is necessary. Unfortunately, the most common screening instruments for adolescent substance use rely on information obtained solely from self-report. This type of data, although useful, is also susceptible to inaccuracies due to such factors as …

Investigation Of The Interaction Of Dimeric Ruthenium Complexes With Cytochrome B5, Christopher Dain Rupar

Graduate Theses and Dissertations

Photoreactive complexes to study the kinetics of electron transfer of proteins have been in use for a long time. It has always been speculated that complexes bind near the heme or the electron transfer reaction would not occur. But it is unkown exactly how the complex interacts with the protein. The structural, thermodynamic, and kinetic properties of rat liver microsomal cytochrome b5 were investigated when bound to ruthenium dimer complexes. Heteronuclear Single Quantum Coherence studies support a dynamic binding model of a dimer Ru complex bound near the protein’s heme involving residues H39, E44, G42, V61, G62, and H63. The …

The Cytotoxic And Antimicrobial Properties Of Pine Essential Oils: A Characterization And Comparison, Richard Sakul

Graduate Theses and Dissertations

In the forestry industry, the pine tree species are important because of their durable timber and fast growth. In Arkansas, trees such as the loblolly pine compose almost a third of the timberland, seven million acres. In addition to the lignocellulosic biomass, pine bark and needles potentially have industrial importance as a waste stream from which high value (e.g., pharmaceutical, cosmetics) chemicals could be extracted, which could potentially increase the profit margin of forestry operations. In this research, the possibility that pine needles harvested from industry processed pine tree residues could be used as an antibacterial or cytotoxic chemical agent …

Studies In The Asymmetric Synthesis Of The C21-C34 Fragment Of The Natural Product, Antascomicin B, Brian Lee Walker

Graduate Theses and Dissertations

This dissertation describes studies in the asymmetric synthesis of the C21 – C34 fragment of the natural product, antascomicin B. Antascomicin B is structurally related to FK506, binds strongly to FKBP12, yet does not shown immunosuppressive activity. Small ligand FKBP12 binding complexes were shown to have potent neuroprotective and neuroregenerative properties in mouse models of Parkinson’s disease. The highlighted chemical reactions include an asymmetric transfer hydrogenation (ATH), Ireland-Claisen rearrangement (ICR), directed hydrogenation and allylic diazene rearrangement.

Effects Of Amino Acid Supplementation Of Reduced Crude Protein (Rcp) Diets On The Performance And Carcass Quality Of Growing-Finishing Swine, Ashley Nicole Young

Graduate Theses and Dissertations

Barrows and gilts (215/gender) were used to test the effects of synthetic AA supplementation of reduced CP diets on the growth performance and quality characteristics of the LM and the fatty acid composition of the LM and s.c. jowl fat from growing-finishing swine. Pigs were blocked by BW within gender, and allocated randomly to pens (6 pigs/pen) which were then assigned randomly within each block and gender to either corn-SBM diets 1) that were devoid of synthetic lysine (Ctrl); 2) with reduced CP diets where lysine was added to all diets (RCP1); 3) with reduced CP where lysine, threonine, and …

Children’S Peer Relationship Quality And Changes In Peer Victimization: The Search For Viable Intervention Targets, James Thomas Craig

Graduate Theses and Dissertations

Stable peer victimization during childhood and adolescence has been linked to both concurrent and future Social and psychological maladjustment (e.g., Hawker & Boulton, 2000; Juvonen, Graham, & Schuster, 2003; Kaltiala-Heino, Rimpela, Rantanen, & Rimpela, 2000; Reijntjes, Kamphuis, Prinzie, & Telch, 2010). Currently, there is evidence to suggest the quality of children’s peer relationships is associated with the level and course of their victimization experiences (e.g., Fox & Boulton, 2006; Schwartz, McFayden-Ketchum, Dodge, Petit, & Bates, 1999; Wolke, Woods, & Samara, 2009). Although the link between peer relationship quality and victimization has been well-documented in the literature; lacking is a thorough …

Revisiting Social Isolation In America: An Egocentric Analysis Of "Feel Close To" Networks, Chao Liu

Graduate Theses and Dissertations

Evidences from interpersonal networks in which Americans discuss “important matters” (core discussion networks) suggest that Americans have become increasingly isolated. Using the national representative Science of Generosity Survey 2010, this paper revisits the issue of Social isolation. The survey asked respondents to name the people they felt close to in the last six months. On average, respondents mentioned 3.87 people they felt close to, a significant increase from the 1985 (2.94) and 2004 (2.08) core discussion networks. Education, income, and gender are significant explanatory variables for the “feel close to” networks. People with high education, those with high income, and …

Modeling And Simulation Of 1700 V 8 A Genesic Superjunction Transistor, Staci E. Brooks

Graduate Theses and Dissertations

The first-ever 1.7kV 8A SiC physics-based compact SPICE model is developed for behavior prediction, modeling and simulation of the GeneSiC “Super” Junction Transistor. The model implements Gummel-Poon based equations and adds a quasi-saturation collector series resistance representation from a 1.2 kV, 6 A SiC bipolar junction transistor model developed in Hangzhou, China. The model has been validated with the GA08JT17-247 device data representing both static and dynamic characteristics from GeneSiC. Parameter extraction was performed in IC-CAP and results include plots showing output characteristics, capacitance versus voltage (C-V), and switching characteristics for 25 °C, 125 °C, and 175 °C temperatures.

Cross Validation Of The Caregiving Helplessness Questionnaire: Associations With Maternal History Of Maltreatment And Intimate Partner Violence, Maegan Calvert

Graduate Theses and Dissertations

Disorganized caregiving has been associated with both maternal childhood history and current experiences of trauma. However, the methods by which disorganized caregiving has been studied have been time intensive and costly. The current study aimed to extend previous research with the Caregiving Helplessness Questionnaire (CHQ; George & Solomon, 2011), which is a self-report measure designed to assess aspects of disorganized caregiving such as caregiving helplessness, role reversal, and frightened/frightening caregiving experiences. Participants (N = 156) were a community sample of mothers of children ages 5 to 10 who were primarily white and who reported a range of traumatic experiences. It …

Stream Microbial Communities As Potential Indicators Of River And Landscape Disturbance In North-Central Arkansas, Wilson Howard Johnson

Graduate Theses and Dissertations

In the past decade, 29 shale basins have been actively developed across 20 states for extraction of natural gas (NG) via horizontal drilling/hydraulic fracturing (=fracking). This includes ~5000 wells within the Fayetteville shale of north-central Arkansas. Development often impacts both river- and landscapes, and management requires catchment-level evaluations over time, with organismal presence/absence as indicators. For this study next-generation sequencing was used to identify/characterize microbial communities within biofilm of eight Arkansas River tributaries, so as to gauge potential catchment influences. Streams spanned a gradient of landscape features and hydrological flows, with four serving as ‘potentially impacted catchment zones’ (PICZ) and …

A Gentleman's Burden: Difference And The Development Of British Education At Home And In The Empire During The Nineteenth And Early-Twentieth Centuries, Jeffrey Willis Grooms

Graduate Theses and Dissertations

A Gentleman's Burden is a comparative analysis of state-funded primary education in Britain, Ireland, West Africa, and India during the nineteenth and early-twentieth centuries. Starting with early-nineteenth century theories on primary education, this dissertation traces the evolution of state-funded educational ideology alongside Britain's domestic and imperial development. Key innovations in educational ideology are considered alongside the core moments of educational change during this period, specifically the major policies and reforms that shaped British state-funded education at home and abroad. Through this lens, education is shown to be a central component in how British officials and educationists perceived, categorized, and ruled …

Lidar-Assisted Extraction Of Old Growth Baldcypress Stands Along The Black River Of North Carolina, Weston Pierce Murch

Graduate Theses and Dissertations

The remnants of ancient baldcypress forests continue to grow across the Southeastern United States. These long lived trees are invaluable for biodiversity along riverine ecosystems, provide habitat to a myriad of animal species, and augment the proxy climate record for North America. While extensive logging of the areas along the Black River in North Carolina has mostly decimated ancient forests of many species including the baldcypress, conservation efforts from The Nature Conservancy and other partners are under way. In order to more efficiently find and study these enduring stands of baldcypress, some of which are estimated to be more than …

Recognition Training For Faces Across Age Gaps, William Blake Erickson

Graduate Theses and Dissertations

Face recognition is a problem that has theoretical and applied value. However, the fact of facial aging is rarely addressed in research and unmentioned in the major theories of face recognition. Facial aging also has ramifications for missing persons and fugitive cases, confounding attempts by law enforcement to recover these people whose last known images are years or decades out of date. This dissertation reports three studies aimed at measuring baseline age-gap recognition ability and testing various training regimens designed to increase accuracy rates for this unique kind of recognition task.

Algal Wastewater Treatment And Biofuel Production: An Assessment Of Measurement Methods, And Impact Of Nutrient Availability And Species Composition, John F. Chamberlin

Graduate Theses and Dissertations

In order to move towards a more sustainable future, human civilization will need to decrease its impacts on air and water quality and minimize consumption of fossil fuels. Using algae for wastewater treatment and biofuel production offers one approach to progress towards these goals simultaneously. Algae are capable of removing nutrients from wastewater and carbon dioxide from the air, and the biomass formed in that process can be used to generate a wide-range of products including fertilizer or fuels that could power combustion engines, power plants, or zero-emission fuel cell vehicles. Using wastewater for biofuel production has the potential to …

Genetic Determinism Of Xanthomonas Arboricola Pv. Pruni (Xap) Resistance, Fruit Quality, And Phenological Traits In Peach And Incorporation Of Marker-Assisted Selection (Mas) In The University Of Arkansas Peach And Nectarine Breeding Program, Terrence James Frett

Graduate Theses and Dissertations

For over two decades the incorporation of marker-assisted selection (MAS) has been discussed as an innovative approach to increase peach breeding efficiency. Although hundreds of quantitative trait loci (QTLs) have been identified, only a few have been converted into usable MAS tools. This highlights a disconnect between genomic discoveries and practical application in breeding programs, which has delayed use of MAS.

In this dissertation, three sequential steps were performed with the objective to bridge this gap and develop breeding-relevant DNA tests for MAS of fruit bacterial spot resistance (Xap1 and Xap6), fruit quality [blush (Rf), acidity (D), and acidity and …

Structural Identification Of An Elevated Water Tower, James Thomas Norris

Graduate Theses and Dissertations

Elevated water tanks are generally located at higher elevations within a particular geographic area. The location and height of these structures often makes them desirable for installing wireless and cellular communications antennas. The impact of this practice on the long-term serviceability performance of the primary structure is not clear and could be an important consideration deserving further analysis. This paper presents a case study of an elevated water tank that was motivated by this particular consideration. The structure had been retrofitted with cellular antennas during its service and later experienced fatigue cracking at the fill pipe-tank interface. The owner wished …