Doctoral Dissertations
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ItemBarriers and Facilitators Influencing Infant Feeding Practices of Black Mothers: A Scoping Review of the Literature and a Quantitative Study(Middle Tennessee State University, 2021)Breastfeeding has been shown to provide health benefits to an infant as well as the mother. Although existing literature demonstrates the benefits of breastfeeding, Black mothers continue to have lower breastfeeding initiation and duration rates compared to other racial and ethnic groups. Prior studies have examined various factors such as breastfeeding knowledge, the availability of social support, and social determinants to examine the lower rates of breastfeeding within the Black community. Information on barriers and facilitators that significantly influence breastfeeding practices among Black women can be used to develop programs and initiatives. Therefore, the current study adds to the growing body of literature examining impactful breastfeeding variables. Article one is a scoping review of the literature which focuses on Black mothers utilizing breastfeeding social media groups as a form of social support. The scoping study explores the various forms of social support provided through social media and emerging themes within the literature. Additionally, the study highlights the importance of breastfeeding spaces specifically for Black mothers. Within the scoping review, few included articles discuss the wants and importance of a supportive Black breastfeeding community. Supportive communities were described as places where women of shared cultural experiences can bond and feel seen. Lastly, the study explored potential social media strategies to increase breastfeeding rates among Black women. Article two is a quantitative study based on the social ecological model. Although numerous studies on the breastfeeding behaviors of Black women exist within the literature, to our knowledge, this is the first study focusing on Black women in Tennessee. The purpose of the study is to determine barriers and facilitators within the levels of the social ecological framework which influence breastfeeding initiation and duration among Black women residing in Tennessee. Quantitative survey data were analyzed to determine which multi-level predictive variables impacted breastfeeding initiation within one hour of birth and breastfeeding duration rates. Study findings indicate that prenatal self-efficacy, assistance from a birth worker, and social support were significant determinants of breastfeeding within one hour of birth and breastfeeding durations.
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ItemThe Impact of Family Involvement on Academic Success in College: A Comparison of Black Students(Middle Tennessee State University, 2021)This study examined the impact of family involvement on academic achievement of Black students. The Family Involvement and Academic Success questionnaire was divided into three sections that included the Family Involvement Scale, demographic information, and student grade point average. Participants included 93 Black students from a four-year public university in middle Tennessee. The research found there was a difference in family involvement between Black first- and second-generation students and a relationship to specific behaviors that family participated in, such as freshmen orientation.
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ItemSELECTIVE SYNTHESIS OF AMINES, IMINES AND NITRILES BY A WELL-DEFINED COBALT CATALYST(Middle Tennessee State University, 2021)The chemistry of amine, imine and nitrile-containing compounds plays a central role in synthesizing high-value products, e.g., drugs, fertilizer, and fine chemicals. The unquestionable benefits from these products to our society have prompted pharmaceutical and agricultural industries to develop better protocols for their synthesis. The traditional synthetic methods for these chemicals depend on toxic and mutagenic reagents and release huge waste. Hence, it is desirable to find an alternative way that circumvents these issues. Catalytic dehydrogenative coupling of alcohols provides an appealing approach since only water, or hydrogen gas are the possible byproducts, and alcohols are environmentally benign. So far, this research field has been predominated by catalysts containing noble metals, e.g., Pd, Ir, Rh, and Ru. These metals are rare, expensive, and toxic. So, it is highly desirable to search for more sustainable metal alternatives. In recent years, there have been a few breakthroughs on non-precious metal (Fe, Co, Mn, and Ni) based catalysts. However, the pincer ligand-supported catalyst dominates this field, and chemoselectivity control strategies are missing in most studies. Recently, our group developed an air and moisture-stable cobalt molecular catalyst stabilized by a tripodal mixed P/N donor ligand. The cobalt metal is earth-abundant, cheap, and less toxic. This cobalt catalyst showed excellent activities for the dehydrogenation of secondary alcohol into ketone, dehydrogenative homocoupling of primary alcohol into ester, and coupling of a secondary alcohol and primary alcohol into corresponding alcohol and ketone products. In my projects, I further explore the catalytic activities into a dehydrogenative hetero couple of primary alcohol and amine to secondary imine and amine. Also, the hetero couple of primary alcohol and nitrile into α-olefinic and α-alkylated nitrile product with water and/or hydrogen as byproducts. It is discovered that the product's selectivity strongly depends on the amount of base used in the reaction. A catalytic amount of base leads to an imine and α-olefinic nitrile product, while an excess base loading results in an amine and α-alkylated nitrile product. We expect that this study could provide helpful insight into selective organic synthesis and catalyst design.
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ItemAURONE: DERIVATIZATION, REACTION METHODOLOGY DEVELOPMENT, AND ITS UTILIZATION AS A FLUOROPHORE FOR DEVELOPING A FLUOROGENIC PROBE FOR SENSING HYDROGEN SULFIDE(Middle Tennessee State University, 2021)Aurones, a sub-class of the flavonoids with proven therapeutic importance, also exist in variously glycosylated forms. Although a large number of glycosylated aurone derivatives have been isolated from plant sources, no syntheses have been reported yet. Inspired from this gap, here we report the first synthesis of peracetylated glycosyl derivatives of synthetic aurones. The direct O-glycosylation was achieved by reacting 6-hydroxy aurones with 2, 3, 4, 6-tetra-O-acetyl-α-D glucopyranosyl bromide in the presence of a phase transfer catalyst tetrabutylammonium bromide (TBAB). The successful synthesis of aurone glycosides (33 examples) in 60-92% yield will benefit the synthesis of combinatorial libraries of glycosylated aurones for their biological study and comparison with non-glycosylated aurones. Similarly, in an attempt to prepare azido-substituted aurones via a copper-catalyzed azidation, the reaction failed to afford the desired product but instead resulted in an unusual triazole formation reaction. Further efforts noted that copper was not required for this reaction but simply thermal treatment with sodium azide in a polar aprotic solvent. A wide range of substitution patterns was tolerated in this reaction to afford the interesting salicyl-substituted triazoles in modest to excellent yield. While the mechanism is not yet clear, a simple elimination/cyclization pathway seems unlikely given the failure of the reaction on the corresponding thioaurones, which feature an even better thiol leaving group. Regardless, the potential utility of these easily accessible, multifunctional compounds should engender further interest and applications. Besides derivatizing aurone scaffolds for combinatorial library synthesis and developing a reaction protocol for the synthesis of a unique and unexplored salicyl-substituted triazoles scaffold, we utilized the aurone scaffold to develop a fluorescent probe for hydrogen sulfide detection in biological as well as environmental situations. While many methods are currently available, the most sensitive and biologically applicable ones are fluorescent-based. In general, these fluorescent probes are based upon large, high-molecular-weight, and well-characterized fluorescent scaffolds that are synthetically demanding to prepare and difficult to tune and modify. We have developed a new system based upon a synthetically simple aurone scaffold that features good sensitivity, selectivity for hydrogen sulfide, and has potential for application in a variety of contexts.
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ItemOn fitting the morphology of simulations of interacting galaxies to synthetic data(Middle Tennessee State University, 2021)Gravitational interactions between galaxies represent a fundamental cosmological process. These interactions are responsible for numerous aspects of the formation and evolution of galaxies, such as enhanced and suppressed star formation rates, the development of tidal features, and the feeding active galactic nuclei. Given observational data from systems of interacting galaxies, we seek to determine the values of various dynamical parameters through the optimization of numerical models via genetic algorithms. However, fitting these models can be quite difficult. The core challenges include 1) developing an objective fitness function for quantifying the similarity between model and target images, 2) understanding the inherent symmetries of the dynamical system which promote morphological degeneracies and impede optimization, 3) determining the optimal genetic algorithm operators for the problem. In this dissertation, we show how naive implementations of fitness functions can yield unintuitive results. We then propose a novel fitness function which was developed by utilizing data from the \textit{Galaxy Zoo: Mergers} project (GZM). The human-scored models obtained from GZM were used to validate our fitness function and led to the adoption of a tidal distortion term which dramatically improved results. We also give a characterization of various geometric and dynamical symmetries inherent within the system and show how the knowledge of these symmetries can be used to reduce the volume of the parameter search space when performing optimization. Lastly, we implement a real-coded genetic algorithm with features designed to address these symmetries. Using simulated target systems with known parameters as a surrogate for observational data, we test our fitness function and genetic algorithm for robustness, accuracy, and convergence. We discuss the link between the degree of tidal distortion present in a target image and the constraints on the dynamical parameters using three different target systems with varying morphology. As an offshoot of our development of our work on the galaxy optimization problem, we also present a kernel mixing strategy which can be applied in both stochastic optimization and adaptive Markov chain Monte Carlo contexts. The method is flexible and robust enough to handle parameter spaces that are highly multimodal. We provide results from several benchmark problems, incorporating the method into simulated annealing, real-coded genetic algorithm, and adaptive Markov chain Monte Carlo contexts. Results show a significant increase in performance in variants of these methods which incorporate the mixing strategy over those which do not.