Digital Commons Network^™

Processing And Characterization Of Innovative Magnesium Alloys For Biodegradable Orthopaedic Implants, Christopher E. Smith

Dissertations

There is a need for innovation in medical implant devices through novel biomaterials that will improve the quality of life. The first step in the creation of a foundation of knowledge and technology to improve these implant devices is through the creation of new alloys with the capabilities of biodegradation and bioabsorption without a toxic effect that will pass through FDA regulatory procedures. In this study, unique heat treatment processing techniques coupled with innovation in elemental alloying produced distinctive magnesium (Mg) based alloy systems. The MgZnCa system was used as the underpinning system where four groups of novel alloys were …

Utilizing Canines In A Public School Setting: A Case Study, Krista J. Tate

Dissertations

Children and adolescents arrive at schools with more than just academic needs. Unfortunately, accountability is paramount in the minds of legislators, thus making test scores top priority for most public educators. For decades, pet therapy and pet assisted activities have been quite successful in mental health institutions, hospitals, and nursing homes. However, the body of work concerning pet therapy and pet assisted activities in public education is limited. The purpose of this case study was to determine if pet therapy is successful in a southwest Missouri school district and to examine how teachers and administrators employ their pet therapy dog. …

Gdnf Content And Nmj Plasticity In Slow And Fast Twitch Myofibers Follows Recruitment In Exercise, Amy Morrison Gyorkos

Dissertations

Glial cell-line derived neurotrophic factor (GDNF) supports and maintains the neuromuscular system during development and through adulthood by promoting neuroplasticity. GDNF may play a role in delaying the onset of aging and help compress morbidity by preventing motor unit degeneration. Exercise has been shown to alter GDNF expression differently in slow and fast twitch myofibers. The aim of this dissertation project is to determine if different intensities of exercise can promote changes in GDNF expression and neuromuscular junction (NMJ) morphology in slow and fast twitch muscle fibers. Skeletal muscle fibers were analyzed from adult Sprague Dawley rats aged 4 weeks …

Synthesis, Characterization And Potential Applications Of Palladium And Ruthenium Nanostructures, Clara Patrice Adams

Dissertations

Controlling the size and shape of metal nanostructures is important for tuning the intrinsic chemical and physical properties of materials, and consequently their potential technological applications. Modulating the morphology of metal nanostructures is essential to understanding the structure-function relationship (for example, optical, magnetic, catalytic, and electronic properties) under various environmental conditions. Our work describes the development of new procedures for the synthesis of well-defined isotropic and anisotropic nanoparticles consisting of palladium (Pd) and ruthenium (Ru). Characterization of the nanostructures was carried out using transmission electron microscopy (TEM), high resolution-TEM (HRTEM), powder x-ray diffraction (XRD), selected area electron diffraction (SAED) and …

Impulsive Choice In Unmedicated And Medicated Children Diagnosed With Adhd: Examining The Variables Of Reward Type And Adhd Subtype, Nicole Henriksen

Dissertations

Developmentally inappropriate and impairing impulsive behaviors are often seen in attention-deficit/hyperactivity disorder (ADHD). One method for objectively assessing impulsivity is the Choice-Delay Task (C-DT) which presents repeated opportunities to choose between a smaller, sooner (SS) or larger, later (LL) reward. A preference for the SS reward that results in less total reward is considered impulsive. Many studies have found that participants diagnosed with ADHD choose the SS reward more than typical controls. However, less is known about the effects of different types of rewards, or the comparative performance of certain subgroups, such as children diagnosed with ADHD Predominantly Inattentive Type …

Does Participation In A Multi-Modal Activity-Based Program Impacts On Functional Recovery, And Quality Of Life In Adults With Spinal Cord Injury?, Carolyn S. Gerber Phd, Msn, Rn

Dissertations

The purpose of this study was to explore the relationships between relevant personal factors, participation in a multi-modal activity-based training program, and the program's impact on an individual's level of functional recovery, and overall quality of life in adults with Spinal Cord Injury (SCI). A descriptive, correlational design was performed on a secondary analysis dataset to conduct this study. Inferential statistics were performed with mixed ANOVA's on measures of ASIA UEM and LEM scores, EuroQol, and SWLS to compare their means. The study proposed that participation in a multi-modal activity-based training program would be associated with greater functional recovery, less …

Rate Alterable Traumatic Brain Injury Device For Rodent Models, Radia Abdul Wahab

Dissertations

Traumatic Brain Injury (TBI) is a physical impact to the head resulting in functional deficits in memory and motor systems. TBI is a prevalent problem occurring in 1.7 million people annually in the United States (Faul et al. 2010). TBIs can differ greatly in terms of the biomechanics of the impact such as magnitude, direction and rate. Indeed, it is likely that the wide range of TBI outcomes may be due to the physical characteristics of the trauma. Studies to date on impact have used injury devices with limited alterable parameters. Therefore, the existing impact studies have considered the effect …

Analyses Of Groundwater Contribution To A Riverine Wetland, Farzad Mahmoodinobar

Dissertations

Rainfall, runoff, overbank flow and groundwater, all contribute water to wetlands. Each transport element is associated with unique modeling approaches and uncertainties. Transpiration is perhaps the hardest to quantify as it is subject to all the variability of plant growth. Transpiration causes land area to lose moisture and the loss amount depends on precipitation incidence, the temperature and type and extent of vegetation. Plants can intercept virtually all recharge during the growing season and almost none from late fall to early spring in northeastern United States. Thus, an improvement in the transpiration element can contribute considerably to an improved groundwater …

Green Vs. Sustainable: Analyzing And Expanding Leed (Leadership In Energy And Environmental Design), Sonay Aykan

Dissertations

This dissertation investigates the possibility of including new socio-economic indicators in green building rating systems in order to promote innovative practices in the building planning, design, construction and operations by introducing a broader definition of sustainability in the building industry. It provides a comparative analysis of the frameworks, indicators and measurement methods of Leadership in Energy and Environmental Design (LEED), which is a voluntary green building rating system, and the reporting guidelines of Global Reporting Initiative (GRI) by examining several selected socio-economic indicators from GRI and questioning the possibility of introducing similar indicators (credits) in LEED. By doing so, it …

Is The Public Invited? Design, Management And Use Of Privately Owned Public Spaces In New York City, Te-Sheng Huang

Dissertations

Researchers in urban planning, urban design, landscape architecture and sociology often criticize the increasing privatization of public space in the US for limiting the diversity of uses and users. Privately owned public spaces in New York City have received this critique. However, careful empirical research, with onsite observations of specific spaces and interviews with building managers, architects and city officials, is still largely lacking. Nor have researchers systematically investigated the full range of design features and management regulations and practices that do, or do not, serve to exclude certain kinds of activities and occupants. This study does precisely that as …

A Modeling Study Of The History-Dependence Of Conduction Delay In Unmyelinated Axons, Yang Zhang

Dissertations

Conduction delay in an axon is the time required for an action potential to propagate between two positions. It is a function of the axon’s passive membrane properties, voltage-gated ion channels and the Na+/K+ pump, and can be substantially affected by neuromodulators. The conduction delay of action potential, generated by the pyloric dilator (PD) neuron unmyel i nated motor axon in the stomatogastric nervous system, shows significant variability with ongoing bursting or Poisson stimulation. When the axon is stimulated, the mean value (Dmean) and coefficient variation of conduction delay (CV-D) slowly increase with time (slow timescale effect), and the relationship …

Performance Analysis And Scheduling Strategies For Ambulatory Surgical Facilities, Xuanqi Zhang

Dissertations

Ambulatory surgery is a procedure that does not require an overnight hospital stay and is cost effective and efficient. The goal of this research is to develop an ASF operational model which allows management to make key decisions. This research develops and utilizes the simulation software ARENA based model to accommodate: (a) Time related uncertainties – Three system uncertainties characterize the problem (ii) Surgery time variance (ii) Physician arrival delay and (iii) Patient arrival delay; (b) Resource Capture Complexities – Patient flows vary significantly and capture/utilize both staffing and/or physical resources at different points and varying levels; and (c) Processing …

Computational Optimization Methods For Modeling The Effect Of Muscle Forces On Bone Strength Adaptation, Catherine Siena Florio

Dissertations

An improved understanding of the mechanical influences that alter the strength of a bone can aid in the refinement of the wide array of currently available techniques to counteract the losses of bone strength that occur due to age or disuse both on Earth and in Space. To address this need, computational modeling methods to quantitatively analyze and compare the effects of mechanical factors on the strength of a targeted bone within a multibone, multimuscle system are developed and implemented in this work. Through a more detailed representation of the system in which the bone acts and the creation of …

In Vitro Modeling And Analysis Of Axon Stretch Growth For The Sustained Growth Of Long Nerve Fibers, Joseph Rocco Loverde

Dissertations

The integration of long nerve fibers throughout the body is distinctive among somatic tissues. Single, individual motor neurons grow to a meter in length or more as they maintain connectivity with sacral areas of the spinal cord from the brain. Similarly, homologous growth also occurs via spinal ganglion neurons within the peripheral nervous system. The most widely studied aspect of nerve development has been the migration and extension of growth cones towards synaptic targets during early development. However, following growth cone extension, axonal fibers continue to grow in synchrony with the expansion of limbs and mit otic tissues throughout childhood …

A Distributed Model Of Oilseed Biorefining, Via Integrated Industrial Ecology Exchanges, Jeremy C. Ferrell

Dissertations

As the demand for direct petroleum substitutes increases, biorefineries are poised to become centers for conversion of biomass into fuels, energy, and biomaterials. A distributed model offers reduced transportation, tailored process technology to available feedstock, and increased local resilience. Oilseeds are capable of producing a wide variety of useful products additive to food, feed, and fuel needs. Biodiesel manufacturing technology lends itself to smaller-scale distributed facilities able to process diverse feedstocks and meet demand of critical diesel fuel for basic municipal services, safety, sanitation, infrastructure repair, and food production. Integrating biodiesel refining facilities as tenants of eco-industrial parks presents a …

Producing A Past: Cyrus Mccormick's Reaper From Heritage To History, Daniel Peter Ott

Dissertations

"Producing a Past" explores how the false "fact" of Cyrus McCormick's 1831 invention of the reaper came to be incorporated into the American historical cannon. From 1884 to 1932, the McCormick Harvester family and their various affiliated businesses created a useable past about their departed patriarch, Cyrus McCormick, and his role in producing civilization through advertising and the emerging historical profession. The McCormick narrative of the past which was peddled in advertising and supported in scholarship justified the family's elite position in American society and its monopolistic control of the harvester industry in the face of political and popular antagonism. …

The Hierarchical Piecewise Linear Approximation Of Time Series Data, Vineetha Bettaiah

Dissertations

The primary contribution of this dissertation is the development of a new time series representation technique called the Hierarchical Piecewise Linear Ap- proximation (HPLA), which facilitates the development of an efficient and effective approach for time series matching. In the HPLA representation, a time series is partitioned into segments between identifiable perceptually important points called primary breakpoints, and each segment is represented independently at several levels of accuracy by placing additional secondary breakpoints between adjacent primary breakpoints. For a given compression ratio, the HPLA representation achieves higher reconstruction accuracy and retains local evolution trends better than the existing time series …

Carnosic Acid Enriched Rosemary Extract Prevents Obesity And Metabolic Syndrome In High-Fat Diet-Fed Mice, Rashin Sedighi

Dissertations

The objective of this study was to investigate the preventive effects of rosemary leaf extract (RE) and its active components on prevention of weight gain and associated metabolic disorders in high-fat-fed mice; determine the effective doses of the chief compound in RE to reduce weight gain and hyperglycemia; and try to understand the underlying anti-obesity mechanism. For this purpose, commercial RE with 45% carnosic acid (CA) was enriched with CA to 80%. Animals were given low-fat diet (LFD), high-fat diet (HFD), high fat with 0.50% RE (enriched with 45% CA, RE#1), high fat with 0.28% w/w RE (enriched with 80% …

Design And Implementation Of An X-Band Passive Rfid Tag, Praharshin Melaka Senadeera

Dissertations

This research presents a novel fully integrated energy harvester, matching network, multi-stage RF-DC rectifier, mode selector, RC oscillator, LC oscillator, and X-band power amplifier implemented in IBM 0.18-µm RF CMOS technology. We investigated different matching schemes, antennas, and rectifiers with focus on the interaction between building blocks. Currently the power amplifier gives the maximum output power of 5.23 dBm at 9.1GHz. The entire RFID tag circuit was designed to operate in low power consumption. Voltage sensor circuit which generates the enable signal was designed to operate in very low current. All the test blocks of the RFID tag were tested. …

Impact Of Selected Rodenticides On The Acidic And Enzymatic Coagulation Properties Of Milk, Madhavi H. Hathurusinghe

Dissertations

The early detection of chemical contaminants in milk at the farm level is essential to prevent them entering into the food chain. The overall objective of this study was to determine the effect of selected rodenticides on the acidic and enzymatic coagulation properties of milk by using selected strains of lactic acid bacteria (LAB) and to evaluate the suitability of lactic acid bacteria as a biomarker for early detection of toxins in milk. Specific objectives of this study were (a) to determine the optimum growth temperature for lactic acid bacteria in MRS broth for early detection of rodenticides; (b) to …

Modeling And Applying Biomimetic Metaheuristics To Product Life Cycle Engineering, Patrick Tchapdiã© Wanko

Dissertations

Due to its potential for significant impact, interest continues to grow in the assessment of products from a life cycle perspective. As the nature of products shifts from mechanized and Newtonian to more adaptive and complex, the behavior of products more closely resembles biological organisms in community. The change in product nature is increasingly mirrored at the component level. The work presented in this dissertation is twofold. First, the research proposes a general, systematic and holistic classification of life cycle data to transform the design problem into an optimization problem. Second, the research proposes two new metaheuristics (bio-inspired and socio-inspired) …

Reduction Of Enteric Methane Production: A Nutritional Approach, A'Ja V. Duncan

Dissertations

This study investigated the effects of feed particle size and nitrate or fumarate alone or in combination on in vitro fermentation, abundances of methanogens, and methane production. Rumen fluid was collected from a Holstein-Friesian dry cow and a steer (experiment 1) and a dry cow and two steers (experiment 2) averaging 625.4 kg in body weight (BW). The cattle were offered 11.4 kg/d per animal of concentrate diet containing equal amounts of soybean meal, whole cottonseed, and ground corn once a day with grass hay at ad libitum (experiment 1) and 15.9 kg/d per animal of total mixed ration (TMR) …

An Exemplar Woman Leader Of Malawi, Africa: A Narrative Account Of The Honorable Anne Mary Fletcher, Toni Pettiford Bradsher

Dissertations

The purpose of this study was to examine the life experiences, spirituality and a sense of community, and cultural values that undergird the leadership praxis of a woman leader from Malawi, Africa. By accounting for the culturally-situated understandings of leadership and leadership practices of an exemplar woman leader of Malawi, Africa, narrative inquiry methodology (Chase, 2011 &, Clandinin & Connelly, 2000) was employed to create an interpretive framework with which to analyze interviews, stories, and field notes through the lens of an endarkened transnational feminist paradigm (Dillard & Okpalaoka, 2011). An endarkened transnational paradigm includes a sacred responsibility to bring …

Use Of Funds In A Nonprofit Organization As Predictor Of Organizational Effectiveness And Efficiency, Throstur B. Thordarson

Dissertations

Purpose. The purpose of this study is to explore predictive relationships between how funds are used in a religious not-for-profit organization (NPO) and member recruitment. Financial data, from Seventh-day Adventist conferences at the organizational level, were correlated with data on membership recruitment from these same conferences.

Method. This study used a linear time-series analysis where relationships between variables and past values were explored over a 12-year period. Financial data were collected from year-end audited statements and financial activity statements. Published statistical records were used to collect data on membership and member donations.

Findings. This study concludes that Seventh-day Adventist …

Impact Of Gums On The Growth, Viability, And Enzyme Activity Of Lactobacillus Species, Bernice D. Karlton-Senaye

Dissertations

This study investigated the impact of ten selected gums (carrageenan, carrageenan-maltodextrin, guar, locust bean, pectin, pectin- dextrose, pectin-carrageenan, guar-locust bean-carrageenan, inulin, and xanthan) on the growth of eight Lactobacillus strains in laboratory media. The bacterial population for eight Lactobacillus strains was determined in modified basal media at different concentration (0%, 0.25% and 0.5% w/v) of gums stored up to 12 hours at 37 °C. Findings show significant differences (p < 0.05) between the treated and control sample. Guar was found to be the best gum to enhance growth of L. rhamnosus GG B101, L. rhamnosus GG B101, L. delbrueckii subsp. bulgaricus SD35, L. delbrueckii subsp. bulgaricus SD33, L. acidophilus SD 16, L. acidophilus EF7, L. reuteri DSM20016, L. reuteri CF2-2F during 12 hours of storage at 37 C in laboratory media. The population of L. rhamnosus GGB101 in the samples containing gums were significantly (p < 0.05) higher than the control without gums. Samples containing 0.5% gums showed slightly higher bacterial population than those with 0.25% of gum. A minimum of 12 hour of incubation period was shown to be adequate to reach a bacterial population of 6 log CFU/mL in the presence of gums. Addition of guar (0.5%) led to the highest (1.31 log CFU/mL) increase in population of the treated L. rhamnosus GGB101 over the control. There was no marked (p < 0.05) change in pH and titratable acidity. Four different gums (carrageenan, carrageenan-maltodextrin, pectin-carrageenan, guar-locust bean-carrageenan) were selected to determine the effect on the growth, viability and betagalactosidase activity of four selected Lactobacillus strains (L. rhamnosus GG B101, L. rhamnosus GG B101, L. reuteri DSM20016, L. reuteri CF2-2F). Effect of the four selected gums on thegrowth L. rhamnosus GG B101, L. rhamnosus GG B101, L. reuteri DSM20016 in milk were compared to those in modified basal media. Results showed that xanthan induced highest growth of L. rhamnosus GG B103, L. rhamnosus GG B101 in milk whereas carrageenanmaltodextrin led to highest growth of L. reuteri DSM 20016 in the media. Marked differences (p < 0.05) in viability were observed between milk samples containing gums and the control. The presence of carrageenan-maltodextrin led to the highest viable counts (8.76 ± 0.03 log CFU/mL) of L. rhamnosus GGB103 during storage. The average population of L. rhamnosus GGB101 and Lactobacillus rhamnosus GGB103 was 8 log CFU/mL, whereas that of Lactobacillus reuteri DSM20016 and Lactobacillus reuteri SD2112 decreased slightly ( 0.15-0.64 log CFU/mL) to 7 log CFU/mL during the storage period. Viable counts were retained at 7-8 log CFU with no significant difference in the control versus treated strains except in the presence of carrageenanmaltodex. Guar-locust bean-carrageenan led to significant (p < 0.05) highest levels of β-gal activity of L. rhamnosus GGB103 (1287 ± 4.24 Miller units/ mL) compared to the control (78 ± 2.83 Miller units/ mL). L. rhamnosus GG B101and L. rhamnosus GG B103 were the best strains to attain enhanced levels of β-galactosidase activity. This shows that the inclusion of carrageenan-maltodextrin and guar-locust bean-carrageenan in milk could improve growth, viability and achieve an enhanced level of β-galactosidase activity in L. rhamnosus GG B101 and L. rhamnosus GG B103. The information gleaned from this study could be used in the food industry to improve the quality of probiotic functional foods and thereby contribute to the alleviation of lactose malabsorption.

Perception Analytics Of An In-Depth Observational Analysis Of 6th Grade African American Male Students' Personal Agency, Devetta Holman Nash

Dissertations

Existing scholarship on self-concept and its relevance to personal agency in the classroom does not incorporate the lived experiences of African American middle school boys. Today, in the United States, only 10% of 8th grade African American boys can read proficiently (Holzman, 2011). This research study investigates the perceptions of seventeen middle school African American males' classroom experiences to determine factors that contribute to their classroom engagement and personal agency. The study also illustrates that there is a significant need for greater self-identity and self-concept within the learning environment, which allows African American male students to self–actualize their sense of …

The Rate And Process Of Mangrove Forest Expansion On Above- And Belowground Carbon Relations In Coastal Louisiana, Hai Thanh Pham

Dissertations

Global climate change is a major environmental threat to natural and cultural resources in low-lying coastal zones and deltas worldwide. It is expected to have a significant effect on the development of coastal wetlands by changing species range expansion. In fact, recent studies have shown that there has been an increasing mangrove encroachment poleward in the Southern and Northern Hemispheres into temperate saltmarsh zones due to the lack of freeze events. This phenomenon could have a critical impact on the structure and function of tidal wetlands at critical latitudes, especially in carbon sequestration, since mangroves are thought to sequester more …

Teacher Perceptions On Teacher Leadership And Shared Vision In Nc Schools: A Correlational Study Using The Nc Teacher Working Conditions Survey, Mary M. Hemphill

Dissertations

As the landscape of public education continues to evolve, so does the leadership and vision required to meet the needs of this ever-changing academic platform. No longer is academic research focusing solely on school leadership required to lead 21st century students and educators toward success, but rather it is focused on the plethora of factors that inform the development of thriving learning communities across our nation. While much of the educational discourse on leadership and vision speaks to the development of strategies, pedagogies, and leadership preparation for school leaders, there are deficiencies in the literature on teacher leadership and shared …

Direct Writing Of Polymeric Coatings For Corrosion Control And Tunable Release Of Bioactive Materials, Eben Adarkwa

Dissertations

The interface between a medical device and its surrounding tissue can be critical to biocompatibility, performance and therapeutic effectiveness. Careful choice and application of materials at this interface is therefore a key to the success of any medical device. This research employed a novel direct-write inkjet printing technique for polymeric surface modification of bioresorbable AZ31 Mg alloy towards corrosion control and tunable release of bioactive agents. In the first phase of this research, the direct-write inkjet printing technique was successfully used to fabricate thin films of different blends of poly (ester-urethane) urea embedded with taxol coatings on mechanically polished AZ31 …

Cellular Processes Regulating Cytoskeletal Signaling, Insulin Resistance And Calcium Signaling Are Commonly Misregulated In Type 1 And Type 2 Myotonic Dystrophy Patients, Nripesh Prasad

Dissertations

Myotonic dystrophy (DM) is a mutisystemic neurological disorder with an autosomal dominant inheritance involving skeletal and cardiac muscles. There are two different types of DM identified; type1 myotonic dystrophy (DM1) and type2 myotonic dystrophy (DM2). In this study I undertook an intense unbiased investigative approach by profiling the global mRNA, miRNA and protein expression landscape in skeletal muscle biopsies from DM1 and DM2 patients. I also compared the mRNA expression of three transgenic mouse models (DM2-KI, HSA-CTG and HSA-CCTG) with human DM patient muscle biopsy samples. My novel integrated comparative analysis strategy revealed widespread mRNA and miRNA misregulation in DM …