Life Sciences Commons^™

Short Term Memory Of Magnetic Resonance Imaging Technologists, Samuel Maldonado

Walden Dissertations and Doctoral Studies

This study examined the short term memory (STM) difference of magnetic resonance imaging (MRI) technologists versus non-MRI technologists. Human and animal studies have indicated that residual magnetic fields have caused changes within the cerebral structure. Research on residual magnetic fields and their effect on STM is still at its infancy. A quasi-experimental design was used to determine if any significant difference existed between the STM of MRI technologists (n = x) and a control population sample (n = x). The STM of both groups was assessed with the use of the Rivermead Behavioural Memory Test-Third Edition. Solicitation of the participants …

Risk Factors Associated With Severe Acute Respiratory Infections Cases, Ryan Gatdula Ortiguerra

Walden Dissertations and Doctoral Studies

The close proximity of the United States to the Mexican border poses a concern for communicable diseases because of the high flow of population movement. The purpose of this retrospective, quantitative study was to identify risks associated with respiratory diseases using an analysis of archived data from the Severe Acute Respiratory Illness (SARI) surveillance program. Based on the epidemiologic triangle theory, demographic and etiologic factors were analyzed to examine any associations with SARI in this population. Between 2010 and 2012, 798 subjects enrolled in this program, with 336 (42.1%) testing positive for respiratory pathogens. Chi square analysis determined that age …

Influence Of Overweight, Obesity, Social Support, And Self-Efficacy On Breastfeeding Outcomes Among African-American Women, Elizabeth Hoo

Walden Dissertations and Doctoral Studies

Breastfeeding reduces morbidity and mortality among mothers and children, yet African-American women breastfeed at lower rates than women of other racial and ethnic groups do. Higher rates of overweight, obesity, and low socioeconomic status may be contributing factors in this population; however, limited research exists regarding the roles of maternal overweight and obesity on breastfeeding outcomes. The purpose of this study was to examine whether social support and self-efficacy positively influence breastfeeding outcomes among overweight and obese African American women. Self-efficacy and social support theories provided the theoretical framework for the study. Research questions examined whether (a) maternal overweight and …

Evaluating The Impact Of Policies On Production Efficiency Of Nigeria's Rice Economy, Samuel Chukwueyem Rapu

Walden Dissertations and Doctoral Studies

Nigeria, like all other rice consuming nations, has experienced a surge in domestic demand for rice since 1970. However, local rice production has not been sufficient to meet local demand, leading to this demand continually being filled by imports. The Federal Government of Nigeria has initiated subsidies programs intended to improve Nigerian rice farmers' technical and cost efficiency levels. This quantitative study evaluated the impact of these policies on the technical and cost efficiency levels of paddy rice farm households in Nigeria. Farrell's (1957) efficiency theory and production theory served as the theoretical frameworks. Data were collected from a cross-section …

Transcriptome Analysis Of Vaccine Responses To Francisella Tularensis Or Venezuelan Equine Encephalitis Virus, Rebecca Ann Erwin-Cohen

Walden Dissertations and Doctoral Studies

The lack of vaccines for emerging and re-emerging diseases highlights technical gaps and indicates a need for innovative approaches to produce new vaccines. Vaccines may be improved by knowledge of host responses to vaccination, disease pathogenesis, and the effect of age and genetics on vaccine outcome. This study's purpose was to quantitatively assess the molecular epidemiology of Francisella tularensis (Ft) and Venezuelan Equine Encephalitis Virus (VEEV). Study results support the Epidemiology Nexus model which holds that association of changes in gene expression to vaccination facilitate understanding the mechanisms of immune development and link public health and disease epidemiology. My research …

Diabetes Mellitus Type 2: A Quality Improvement And Patient Safety Initiative, Remeliza Navarrete Tukay

Walden Dissertations and Doctoral Studies

The purpose of the quality improvement (QI) project was to examine the relationship between amended nursing education concerning diabetes mellitus (DM) Type 2 self-care management incorporating Tune in, Explore, Assist, Communicate, and Honor (TEACH) and Motivational Interviewing (MI) strategies and techniques and the Glycosylated hemoglobin (HgbA1C) of veteran patients with uncontrolled diabetes. The target sample included the 2 licensed practical nurses and 2 registered nurses assigned to 2 primary care teams, and the 10 purposively sampled patients with uncontrolled DM Type 2 from each team. The nurses' competencies were measured through descriptive comparison before and after nursing education implementation using …

Sustainability Strategies For Value-Added Agricultural Producers In California's San Joaquin Valley, Sharon L. Starcher

Walden Dissertations and Doctoral Studies

Economic and climate changes, combined with changing government regulations, are altering the strategic business model for small farm operators and necessitating their reliance on multiple income sources to maintain financial viability. The purpose of this multiple case study was to explore the strategies of 3 small farming businesses in California's San Joaquin Valley that successfully implemented value-added products which contributed to their financial sustainability. Data from semistructured interviews and relevant documents were analyzed through the lens of system theory, utilizing in vivo coding to identify patterns and themes. Three high-level themes emerged: knowledge, marketing, and networking. The theme of knowledge …

Regulation Of Obesity And Metabolic Complications By Gamma And Delta Tocotrienols, Lu Zhao, Xiefan Fang, Maurice R. Marshall, Soonkyu Chung

Department of Nutrition and Health Sciences: Faculty Publications

Tocotrienols (T3s) are a subclass of unsaturated vitamin E that have been extensively studied for their anti-proliferative, anti-oxidative and anti-inflammatory properties in numerous cancer studies. Recently, T3s have received increasing attention due to their previously unrecognized property to attenuate obesity and its associated metabolic complications. In this review, we comprehensively evaluated the recent published scientific literature about the influence of T3s on obesity, with a particular emphasis on the signaling pathways involved. T3s have been demonstrated in animal models or human subjects to reduce fat mass, body weight, plasma concentrations of free fatty acid, triglycerides and cholesterol, as well as …

Four Weeks Of High- Versus Low-Load Resistance Training To Failure On The Rate Of Torque Development, Electromechanical Delay, And Contractile Twitch Properties, N.D.M. Jenkins, Terry J. Housh, S.L. Buckner, H.C. Bergstrom, C. M. Smith, Kristen C. Cochrane, E.C. Hill, Amelia A. Miramonti, Richard J. Schmidt, G. O. Johnson, Joel T. Cramer

Department of Nutrition and Health Sciences: Faculty Publications

The purpose of this study was to investigate the effects of 4-weeks of high- versus low-load resistance training to failure on rate of torque development (RTD), electromechanical delay (EMD), and contractile twitch characteristics. Fifteen men (mean±SD; age=21.7±2.4 yrs) were randomly assigned to either a high- (80% 1RM; n=7) or low-load (30% 1RM; n=8) training group and completed elbow flexion resistance training to failure 3 times per week for 4 weeks. The participants were tested at baseline, 2-, and 4-weeks of training. Peak RTD (pRTDV) and RTD at 0-30 (RTD30V), 0-50 (RTD50V), 0-100 (RTD100V), and 0-200 (RTD200V) ms, integrated EMG amplitude …

Low Energy Availability In Exercising Men Is Associated With Reduced Leptin And Insulin But Not With Changes In Other Metabolic Hormones, Karsten Koehler, Neele R. Hoerner, Jenna C. Gibbs, Christoph Zinner, Hans Braun, Mary Jane De Souza, Wilhelm Schaenzer

Department of Nutrition and Health Sciences: Faculty Publications

Low energy availability, defined as low caloric intake relative to exercise energy expenditure, has been linked to endocrine alterations frequently observed in chronically energy-deficient exercising women. Our goal was to determine the endocrine effects of low energy availability in exercising men. Six exercising men (V_O2peak : 49.3 ± 2.4 ml · kg⁻¹ · min⁻¹) underwent two conditions of low energy availability (15 kcal · kg⁻¹ fat-free mass [FFM] · day⁻¹) and two energy-balanced conditions (40 kcal · kg⁻¹ FFM · day⁻¹) in randomized order. During one low energy availability and …

Carbohydrate Intake In Form Of Gel Is Associated With Increased Gastrointestinal Distress But Not With Performance Differences Compared With Liquid Carbohydrate Ingestion During Simulated Long-Distance Triathlon, Mahdi Sareban, David Zügel, Karsten Koehler, Paul Hartveg, Martina Zügel, Uwe Schumann, Jürgen Michael Steinacker, Gunnar Treff

Department of Nutrition and Health Sciences: Faculty Publications

The ingestion of exogenous carbohydrates (CHO) during prolonged endurance exercise, such as long-distance triathlon, is considered beneficial with regard to performance. However, little is known about whether this performance benefit differs among different forms of CHO administration. To this end, the purpose of our study was to determine the impact of CHO ingestion from a semisolid source (GEL) on measures of performance and gastrointestinal (GI) comfort compared with CHO ingestion from a liquid source (LIQ). Nine well-trained triathletes participated in this randomized crossover study. Each participant completed a 60-min swim, 180-min bike exercise, and a 60-min all-out run in a …

Suppression Of Nlrp3 Inflammasome By Γ-Tocotrienol Ameliorates Type 2 Diabetes, Yongeun Kim, Wei Wang, Meshail Okla, Inhae Kang, Regis Moreau, Soonkyu Chung

Department of Nutrition and Health Sciences: Faculty Publications

The Nod-like receptor 3 (NLRP3) inflammasome is an intracellular sensor that sets off the innate immune system in response to microbial-derived and endogenous metabolic danger signals. We previously reported that γ-tocotrienol (γT3) attenuated adipose tissue inflammation and insulin resistance in diet-induced obesity, but the underlying mechanism remained elusive. Here, we investigated the effects of γT3 on NLRP3 inflammasome activation and attendant consequences on type 2 diabetes. γT3 repressed inflammasome activation, caspase-1 cleavage, and interleukin (IL) 1β secretion in murine macrophages, implicating the inhibition of NLRP3 inflammasome in the anti-inflammatory and antipyroptotic properties of γT3. Furthermore, supplementation of leptin-receptor KO mice …

Soft Drinks Consumption And Child Behaviour Problems: The Role Of Food Insecurity And Sleep Patterns, Christian King

Department of Nutrition and Health Sciences: Faculty Publications

Objective: To examine whether the association between soft drinks consumption and child behaviour problems differs by food security status and sleep patterns in young children.

Design: Cross-sectional observational data from the Fragile Families and Child Wellbeing Study (FFCWS), which collected information on food insecurity, soft drinks consumption, sleep patterns and child behaviour problems. Bivariate and multivariate ordinary least-squares regression analyses predicting child behaviour problems and accounting for socio-economic factors and household characteristics were performed.

Setting: Twenty urban cities in the USA with a population of 200 000 or more.

Subjects: Parental interviews of 2829 children who were about 5 years …

The Role Of Microrna In Cardioprotection: Ischemic Preconditioning And Mesenchymal Stem Cell Paracrine Effects, Kristin Luther

Dissertations

Changes in gene expression and protein levels are an important aspect of cardioprotection in which short non-coding RNA known as miRNA may play a key regulatory role. We investigated the functions of several miRNAs in the context of two cardioprotective stimuli, ischemic preconditioning (IPC) and mesenchymal stem cell (MSC) paracrine effects. We hypothesized that downregulation of a set of miRNAs (miR-148a/b, miR-30b, and let-7a*) augments expression of protective heat shock proteins during IPC, and that MSC exosomes transfer miR-21 to cardiomyocytes, resulting in downregulation of pro-apoptotic genes and reduction of infarct size.

IPC increased the level of Hsp70, Hsp90, and …

The Amino Terminal Region Of Cardiac Myosin Binding Protein-C Is Necessary For Cardiac Function, Thomas Lawrence Lynch

Dissertations

Cardiac myosin binding protein-C (cMyBP-C) is a thick filament-associated protein that has been suggested to regulate cardiac contraction via its amino terminal (N’) region. Following ischemic injury to the heart, cMyBP-C is cleaved into a predominant N’ fragment consisting of domains C0 through C1 and the first 17 residues of the M-domain that is referred to as C0-C1f. However, the necessity of the N’-C0-C1f region of cMyBP-C in regulating cardiac function in vivo has not been elucidated. I hypothesized that the N’-C0-C1f region of cMyBP-C is critical for normal cardiac function in vivo. To test this hypothesis, transgenic (TG) mice …

Regulation Of The Subunits Of Hypoxia Inducible Factors By Sprouty2 And Its Impact On Different Biological Processes, Kristin Caroline Hicks

Dissertations

The hypoxia inducible factors (HIF1α, HIF2α, HIF1β) promote transcription of genes that regulate glycolysis and cell survival and growth. Sprouty2 (Spry2) is a modulator of receptor tyrosine kinase signaling and inhibits cell proliferation via different mechanisms. Because of the seemingly opposite actions of the HIF and Spry2 on cellular processes, we hypothesized that Spry2 decreases the protein levels of HIF1α, HIF2α and HIF1β by enhancing the proximity of the HIF subunit to an ubiquitin ligase capable of degrading the subunit. Focusing on HIF1α as a prototypical alpha subunit, in a variety of tumor derived cell lines, Spry2 decreases the protein …

Studies Into The Allosteric Regulation Of Adp-Glucose Pyrophosphorylases, Benjamin Luke Hill

Dissertations

The synthesis of glycogen in bacteria and starch in plants is allosterically controlled by the production of ADP-glucose by ADP-glucose pyrophosphorylase. Using computational studies, site directed mutagenesis, and kinetic characterization, and protein crystallography we found a critical region for transmitting the allosteric signal in the Escherichia coli and A. tumefaciens ADP-glucose pyrophosphorylase. Molecular dynamics simulations and structural comparisons with other ADP-glucose pyrophosphorylases provided information to hypothesize communication pathways that link allosteric and active sites, and this was tested by site-directed mutagenesis and kinetic characterization of the mutant enzymes. In addition, the application of x-ray crystallography enabled the pinpointing of the …

Heart And Sole: The Functional Role Of Fast-Skeletal Myosin Binding Protein-C In Cardiac And Skeletal Muscle, Brian Leei Lin

Dissertations

The goal of my dissertation was to compare and contrast the function of all three major isoforms of Myosin Binding Protein-C (MyBP-C): slow-skeletal, fast-skeletal, and cardiac (ssMyBP-C, fsMyBP-C, and cMyBP-C, respectively), with a focus on the least characterized isoform, fsMyBP-C. Using a variety of ex vivo, in vitro, and in silico methods, my research demonstrated that the N-terminal region of all MyBP-C isoforms bind to actin and shift tropomyosin, thus activating the thin filament during contraction. Furthermore, each isoform differentially activated the thin filament over isoform-specific ranges of Ca2+: slow-skeletal activates at low Ca2+, fast-skeletal activates at higher Ca2+, and …

The Impact Of Altered T Cell Receptor—Peptide-Major Histocompatibility Complex Interactions On Antigen Recognition And T Cell Function, Timothy T. Spear

Dissertations

Adoptive cell transfer (ACT) using T cell receptor (TCR) gene-modified T cells is an exciting and rapidly evolving field. Numerous basic science and clinical studies have demonstrated various levels of feasibility, safety, and efficacy using TCR-engineered T cells to treat cancer and viral infections. Genomic instability of targeted diseases, however, requires effective and safe TCRs to cross-recognize mutated antigens while minimizing on- or off-target toxicities. Thus, improvements to T cell-based therapeutics mandate a broader understanding of the principles governing antigen recognition. This dissertation addresses critical biologic questions evaluating which parameters are most important in facilitating antigen recognition, and how alterations …

Inhibition Of B Lymphopoiesis By Adipocytes And Myeloid-Derived Suppressor Cells, Domenick Kennedy

Dissertations

B lymphopoiesis declines with age in humans, mice, and rabbits. Impaired B lymphopoiesis correlates with increased fat in the bone marrow (BM), suggesting that adipocytes negatively regulate this process. In fact, adipocyte factors were found to inhibit B cell development in BM cultures.

Our goal was to understand the mechanism by which adipocytes inhibit B cell development. Through culturing mouse BM cells on OP9 stromal cells in the presence of adipocyte-conditioned medium (ACM), we found that adipocytes promote the accumulation of CD11b+Gr1+ myeloid-derived suppressor cells (MDSCs). These cells were not simply bystanders, as we report for the first time that …

Adventist Affiliation And Type 2 Diabetes Pre- And Post-Complete Health Improvement Program (Chip), Janie Unruh

Walden Dissertations and Doctoral Studies

Adventists following a plant-based diet have half the prevalence and incidence of type 2 diabetes than nonvegetarian Adventists. This study used a quantitative, correlational study design to assess if there was a significant difference in type 2 diabetes prevalence rate between Adventists and non-Adventists preprogram, and if there were significant differences in biometrics between Adventists and non-Adventists with diabetes pre- and post-Complete Health Improvement Program (CHIP). This study incorporated the social ecological model for its conceptual framework and examined pre- and postprogram changes among Adventists (n=210; 20.1%) and non-Adventists (n=836; 79.9%) with type 2 diabetes. It used secondary data from …

Promoting Diabetes Self-Managment Eduaction And Training In Out-Patient Clinics, Inemesit Godwin Udo

Walden Dissertations and Doctoral Studies

Abstract

Type 2 diabetes mellitus (T2DM) is a long term metabolic disorder characterized by high blood sugar, insulin resistance, and relative lack of insulin. T2DM is a leading cause of cardiovascular disease, blindness, kidney failure, lower-limb amputation, and other complications that are costly to patients and the U.S. health care system. Lack of knowledge and underdeveloped skills for self-management of diabetes continues to be the biggest problem for patients with T2DM. Using a team approach and Rosswurm and Larrabee's (1999) conceptual model as a framework, the purpose of this doctorate of nursing practice quality improvement project was to develop an …

Exploring Factors Influencing Information Technology Portfolio Selection Process In Government-Funded Bioinformatics Projects, Braulio J. Cabral

Walden Dissertations and Doctoral Studies

In 2012, the National Cancer Institute's (NCI) Board of Scientific Advisors (BSA) conducted a review of the Center for Biomedical Informatics and Information Technology's (CBIIT) bioinformatics program. The BSA suggested that the lack of a formal project selection process made it difficult to determine the alignment of projects with the mission of the organization. The problem addressed by this study was that CBIIT did not have an in-depth understanding of the project selection process and the factors influencing the process. The purpose of this study was to understand the project selection process at CBIIT. The research methodology was an exploratory …

Influences Of Nutritional Food Label Understanding In African-American Women With Obesity, Cynthia Jean Hickman

Walden Dissertations and Doctoral Studies

Nutritional food label understanding (NFLU) in African American Women (AAW) is a philosophy that addresses obesity. Public health efforts have implemented nutritional and caloric information to packaged and restaurant foods to improve nutrient and calorie literacy. Research suggest NFLU might have a minimal effect on reducing obesity. However, it is not known how obese AAW born during the baby-boom era (51 to 64 years of age) perceive NFLU in relation to their dietary behaviors. The purpose of this phenomenological study was to understand the lived experience of obese AAW regarding NFLU from a cognitive and behavioral perspective. Twelve, AAW answered …

Equine Facilitated Psychotherapy For Veteran Survivors With Full Or Partial Ptsd, Mark Aaron Mayfield

Walden Dissertations and Doctoral Studies

Symptom severity among veteran survivors with partial or full posttraumatic stress disorder (PTSD) continues to increase, with approximately 40% of U.S. veterans reporting significant symptomology 10 years after initial onset of the condition. Veteran survivors often struggle to find therapeutic interventions that meet their specific needs and have a difficult time maintaining a therapy that is both equitable and evidenced based. Grounded in the Rogerian, client-centered theory, the purpose of this qualitative collective exploratory case study was to explore the effects of equine-facilitated psychotherapy with 3 veteran survivors with partial or full PTSD. A 4-stage process was used to collect …

Performance Measures Of Road Crossing Structures From Relative Movement Rates Of Large Mammals, Adam Andis

Graduate Student Theses, Dissertations, & Professional Papers

In recent decades, there has been an increase of engineering projects that seek to mitigate the barrier effect roads impose on wildlife by installing wildlife crossing structures that promote permeability of the road corridor. The 41 fish and wildlife crossing structures installed along a 90km stretch of US Highway 93 on the Flathead Indian Reservation in western Montana, represent one of the most extensive of such projects in North America. As mitigation efforts are increasingly considered and implemented in road construction projects, the need to assess these structures’ effectiveness grows. This study is the first to compare observations of animal …

Baseline Study Of Recovering Headwater Streams In The Sapphire Mountains, Western Montana, Morgan Vinyard

Graduate Student Theses, Dissertations, & Professional Papers

Many riparian areas in the western United States have been degraded by grazing and logging. In the year 2000, the Montana Department of Environmental Quality (DEQ) re-initiated an effort to identify and characterize reference streams, or least impacted streams in each region of the state. In Montana’s Bitterroot Valley, most streams have been impacted by grazing, irrigation, and timber production. The Montana DEQ has not been able to identify reference streams in the Sapphire Mountains on the east side of this valley. MPG Ranch, located on the west-facing slopes of the Sapphire Mountains and purchased in 2009 by a conservation-minded …

Spatio-Temporal Analysis Of Ungulate Browsing On Willow (Salix Spp.) Communities Within The Northern Range Of Yellowstone, Donald L. Belile Jr.

Graduate Student Theses, Dissertations, & Professional Papers

Variation in ungulate browsing intensity on willow (Salix spp.) communities across Yellowstone’s northern range has been attributed to various biophysical factors including climate, topography, and predators. These studies were conducted without a long-term browsing dataset; they lacked a spatially extensive sampling design, and did not include dynamic snow characteristics known to affect ungulate mobility, habitat selection, and foraging strategies. We therefore focused on snow, an extreme landscape level disturbance that places nutritional stress on ungulates during the winter when most browsing on shrubs occurs. We applied a non-destructive sampling method by consecutively recording whether stem leaders were browsed between …

Conservation Genetics On The Frontline, Kenneth W. Rand

Graduate Student Theses, Dissertations, & Professional Papers

Conservation genetics stands out as an effective tool for discovering and monitoring rare, endangered or invasive populations of plants and animals. Particularly when compared to traditional search and capture methods, it provides more holistic studies to preserve the disappearing biodiversity of the American West and the world.

Three stories highlight the work done to preserve biodiversity through the use of conservation genetics:

1. Trout Rescue: A new hope for westslope cutthroat in Montana How to save a disappearing westslope cutthroat trout through genetic rescue by adding genetic diversity to ensuring future survival in increasingly warming waters more harm than good. …

Impacts Of Recreational Aviation On Wildlife: The Physiological Stress Response In White-Tailed Deer (Odocoileus Virginianus) And Associated User Perceptions, Devin W. Landry

Graduate Student Theses, Dissertations, & Professional Papers

Recreational aviation on public lands may negatively impact wildlife. However, land-use decisions need to balance user need with wildlife impact. We know very little about 1) how back country airstrip use affects local wildlife, or 2) attitudes and perceptions of recreational pilots toward possible management actions. For my Master’s research, I investigated how aircraft activity influenced physiological measures of stress in white-tailed deer, while also modeling how psychometrics such as wildlife attitudes and place attachment predict the willingness of recreational pilots engage in impact-mitigating behaviors. I measured physiological stress through non-invasive sampling of stress hormones in fecal samples (fecal glucocorticoid …