Electronic Theses and Dissertations (ETDs) are digital representations of student master's theses and doctoral dissertations.


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Recent Submissions

  • An Iterative Procedure to Select and Estimate Wavelet-Based Functional Linear Mixed-Effects Regression Models

    Lundeen, Jordan Sarah; Biostatistics (Augusta University, 2019-12)
    Actigraphy is the continuous long-term measurement of activity-induced acceleration by means of a portable device that often resembles a watch and is typically worn on the wrist. Actigraphy is increasingly being used in clinical research to measure sleep and activity rhythms that might not otherwise be available using traditional techniques such as polysomnography. Actigraphy has been shown to be of value when assessing circadian rhythm disorders and sleep disorders and when evaluating treatment outcomes. It can provide more objective information on sleep habits in the patient's natural sleep environment than using the patient's recollection of their activity or a written sleep diary. We propose a wavelet-based functional linear mixed model to investigate the impact of functional predictors on a scalar response when repeated measurements are available on multiple subjects. The advantage of the proposed model is that each subject has both individual scalar covariate effects and individual functional effects over time, while also sharing common population scalar covariate effects and common population slope functions. An iterative procedure is used to estimate and select the fixed and random effects by utilizing the partial consistency property of the random effect coefficients and selecting groups of random effects simultaneously via the smoothly clipped absolute deviation (SCAD) penalty function. In the first study of its kind, we compare multiple functional regression methods through a large number of simulation parameter combinations. The proposed model is applied to actigraphy data to investigate the effect of daily activity on Hamilton Rating of Depression Scale (HRSD), Insomnia Severity Index (ISI) and Reduced Morningness- Eveningness Questionnare (RMEQ) scores.
  • Acquiring Situation Awareness through Hand-Off in a Critical Care Environment

    Holden, Tina; Nursing (Augusta University, 2019-12)
    Hand-off communication is associated with 80% of hospital errors. Situation awareness (SA) has been targeted as a strategy to reduce errors and enhance patient safety when providing hand-off communication. Few studies have focused on the influence of SA in hand-off communication in the intensive care unit where the risk of errors is high. The purpose of this study was to develop a substantive theory of critical care nursing hand-off. The study was guided by Endsley’s SA framework. A qualitative study design using Straussian grounded theory methods was used to develop a substantive theory related to critical care nursing hand-off. Data collection strategies included observation of 20 critical care nursing hand-offs followed by 34 semi-structured interviews and took place from 2017 to 2019 in a medical and surgical ICU at two academic tertiary care facilities. Data analysis was conducted using constant comparative analysis and was guided by Endsley’s model of SA. Results revealed that hand-off is a basic social process with a core category of handing-off awareness. The process contained four phases: interactive, reflective, maintenance, and preparatory. The interactive phase was characterized by communication between the giver and receiver of hand-off. During that phase, the 10 critical elements of hand-off were passed on to the receiver. These critical elements included the code status, past medical history, story, systems assessment, trends, changes, rationale, level of organ support, and anticipation. Handing off these elements in a way that flows with logical order affects awareness. Nursing behaviors of the giver associated with handing off awareness are linked to the critical elements. For the receiver, these behaviors include arriving prepared, reporting the critical elements, controlling flow, and making connections between the critical elements. Behaviors for the receiver include being an active listener, validating information, and asking questions within the flow of information. In the reflective phase, the resilient nurse bridges gaps in awareness. The maintenance phase is characterized by nursing actions that support hand-off information recall. In the maintenance phase, SA is maintained through artifacts. Artifacts are tools used by nurses to aid in the cognitive function of hand-off. The preparatory phase is characterized by information synthesis and organization. The four phases of hand-off are re-occurring and are influenced by individual and organizational factors. Individual factors include a nurse’s personal process, experience, socialization, and emotional intelligence. Organizational factors include unit policies, unit artifacts, and safety culture. Theory and research implications include the need for future research to further expand the framework of SA in hand-off, the use of qualitative methods to provide insight into complex areas of healthcare, and the need for educational interventions on SA hand-off. Practice implications include evaluation of current hand-off practices in the ICU and evaluation of organizational influences on hand-off. The study concludes that the theory of handing-off awareness in the ICU is a continuous process that occurs over four phases in a repetitive cycle that starts again with each shift change. The critical elements, flow, nursing behaviors, time, and external factors influence the ability of the nurse to achieve optimal SA.
  • Evaluating the Impact of High Fidelity Patient Simulation on Clinical Reasoning in Undergraduate Nursing Students

    Gee, Rebecca Mathews; Nursing (Augusta University, 2019-12)
    Introduction: Graduate nurses must enter nursing with clinical reasoning skills that will allow them to appropriately care for patients. With limited clinical sites, nurse educators are challenged to graduate clinically-competent nurses who possess clinical reasoning skills that will allow them to appropriately care for patients. The use of high fidelity patient simulation (HFPS) as an adjunct to clinical experiences may be a solution, but previous studies have shown limited evidence that HFPS improves clinical reasoning in nursing students. A variety of tools have been used to measure clinical reasoning (or one of its components). However, most of them were not specific to nursing. Without a consistent, nursing-specific tool, exploration of HFPS effects on clinical reasoning skills is challenging. The Nursing Specific Script Concordance Test (NSSCT), a validated nursing-specific tool measuring clinical reasoning, was used for this study. The purpose of this study was to examine the impact of HFPS on the clinical reasoning skills of first-semester, pre-licensure, Bachelor of Science in Nursing (BSN) students. Two specific aims were explored: 1) determine whether teaching with HFPS scenarios improved the clinical reasoning skills of pre-licensure, first semester BSN students, and 2) determine whether the NSSCT detected a significant difference in NSSCT mean scores before and after HFPS scenarios. Methods: This study used a two-group, randomized crossover design with 14 first-semester, pre-licensure, BSN students (n = 8; n = 6). Each participant took a baseline NSSCT, followed by the experimental group participating three simulation scenarios and the control group participating in the standard curriculum only. Then a second NSSCT was administered to each participant. Then, the control group participated in the three simulation scenarios while the experimental group participated in the standard curriculum only. Then, a third NSSCT was administered. NSSCT mean scores were compared between and within the groups after each administration. Results: There were no statistical differences (p = 0.494) in mean NSSCT scores in pre-licensure, first-semester, BSN, students after participating in HFPS scenarios, inferring that in this sample, HFPS did not significantly increase clinical reasoning. There were no statistical differences in mean NSSCT scores (p = 0.064) between the control group and experimental group after the second NSSCT administration, suggesting that the clinical reasoning skills were not different between students who completed the three simulation scenarios versus students who participated in the standard curriculum alone. Finally, there were no statistical differences (p = 0.596) between the control group and experimental group after all participants completed the three simulation experiences. Conclusions: The results from this study did not conclude that HFPS improved clinical reasoning in first-semester, pre-licensure, BSN students. However, due to the limitations of this study (small sample size [n = 14], test/retest reliability, and history) a replication study with modifications should be considered to fully examine the effect of HFPS on clinical reasoning in pre-licensure, BSN students.
  • Study of the effects of vitamin A deficiency in albino rats

    Hazlett, James Cummins; Department of Anatomy (1968-06)
  • Effects of the maternal administration of isoproterenol on fetal hamster chromosomes

    Hansen, Kathryn Lousie; Department of Endocrinology (1971-06)
  • Segmental responses of the dog paw vasculature

    Hammond, Mary Corinne; Department of Physiology (1968-06)
  • Subcellular localization of collagen prolyl and lysyl hydroxylation

    Guzman, Noberto A.; Department of Cell and Molecular Biology (1975-08)

    Naughton, Sean X; Biomedical Sciences (Augusta University, 2019-12)
    Organophosphates (OPs) are a broad class of chemicals with a variety of uses that include pesticides, chemical warfare agents, fuel additives, and plasticizers. Due to their sheer number of applications and known toxicological profile, OPs represent a persistent concern to human health worldwide. Furthermore, the effects of OPs that occur independently of their well-known mechanism of acute toxicity (AChE inhibition) have not been well studied. The presented research seeks to expand upon our understanding of AChE-independent mechanisms of OP toxicity as well as to identify potential therapies for treating these negative effects. In Manuscript 1 we demonstrate that the OP diisopropylfluorophosphate (DFP) induced axonal transport deficits occur in vivo at exposure levels that were not associated with cholinergic toxicity. Additionally, we observed deficits in white matter integrity following sub-acute DFP exposure. In Manuscript 2 we present a series of experiments, which were conducted to identify potential therapeutic compounds for the treatment of OP induced deficits in axonal transport. Here, we utilized a phenotypic drug-screening assay in order to identify compounds that could be protective against DFP. In Manuscript 3 we present data which demonstrates that the carbamate physostigmine does not impair axonal transport, as has been previously demonstrated with OPs. These experiments were critical to demonstrating the AChE independence of OP-induced axonal transport deficits and further elucidate the unique nature of OP toxicity in comparison to other AChE inhibitors. Collectively, these studies contribute to a better understanding of the full spectrum of toxicological effects of OPs and provide insightful findings into potential therapeutics for the treatment of OP related toxicity.
  • Primary Tumor-Induced Immunity Is Suppressed By Surgery-Induced Inflammation In The Presence Of Residual Tumor Cells

    Piranlioglu, Raziye; Biomedical Sciences (Augusta University, 2019-12)
    It is widely thought that tumor cells disseminate from a primary site into the circulation during the early stages of tumor development. However, the fate of these early disseminated tumor cells (DTCs) has been elusive. By utilizing the murine mammary tumors, 4T1 and EMT6, in a syngeneic mouse model, we show that both tumors disseminate into secondary organs but only 4T1 tumors are able to generate metastasis. In contrast, EMT6 primary tumors induce an anti-tumor response that leads to elimination of DTCs. This anti-tumor immunity is CD8+ T cell-dependent and provides long-term immunity. Furthermore, the mice are free of DTCs within a couple of days when primary tumors are completely resected and they reject subsequently injected tumors, whereas mice with residual tumors following surgery show enhanced local recurrence and outgrowth of DTCs at metastatic sites; this effect may be explained by elevated levels of granulocyte colony-stimulating factor (G-CSF). This increase is accompanied by an accumulation of immature myeloid-derived suppressor cells (MDSCs) in the spleen and lungs, the main target organ for metastasis. Moreover, the infiltration of a granulocytic subset of MDSCs (gMDSCs) leads to a decrease in a subset of T cells that have a role in long-term immunity. Our goal for this study is to elucidate how immune components of distant organs affect the fate of DTCs and the role of surgery induced-inflammation in generating a pre-metastatic niche. Our studies may also provide a molecular explanation of improved overall survival in breast cancer patients following complete resection of primary tumors with negative margins.
  • Gonadotrophin secretion by the isolated pituitary

    Greeley, George Horace; Department of Endocrinology (1974-09)
  • Mechanism of Action of Ristocetin

    Grastie, Miriam Kay; Department of Cell and Molecular Biology (1970-06)
  • Renal tubular transport of lactate in the dog

    George, Don; Department of Physiology (1975-06)
  • Physiological and biochemical changes from traumatic shock

    Galvin, Michael John; Department of Physiology (1975-06)
  • Influence of methopyrapone (metapirone) on the excretion of urinary steroids

    Freedman, Murray Allen; Department of Endocrinology (1964-06)

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