Electronic Thesis or Dissertation

The study of cranial modifications is valuable to the fields of bioarcheology, and other areas of anthropology. This thesis focuses on analyzing cranial modification in Santander, Colombia. Research focuses on a variety of crania in museums of this region. There is not much known about the crania and there are just a few academic works about them from the social/cultural perspective. Some records do mention that a specific group called “Guane” inhabited the region where the crania were discovered. This investigation from the perspective of bioarcheology is particularly important for better understanding and documenting of these specimens. This research will also help the different museums and collections in documenting the crania they have and provide data to others that may also be interested in these collections.
A general aspect of the methodology that was used to achieve the conclusions were photos, measurements and the determination of the sex and age. It was determined that there is no association between the cranial modifications and the sex. Also, the different modifications, including the form, variety and degree was determined for each cranium.

Navigation of unmanned underwater vehicles in coastal zones, tight spaces and close to structures such as ports, ship hulls and pipelines remains a difficult challenge. Currently Autonomous Underwater Vehicles (AUVs) use a variety of techniques for motion control, including single thrusters with diving planes or hydrofoils, robotic wrists, or a moving mass. However, these techniques provide limited maneuverability. The objective of this work was to understand the mechanics of elongated fin propulsion for swimming and motion control of underwater vehicles. This bio-inspired propulsion is used by several fishes that swim by undulating a thin and elongated median fin that allow them to perform forward and directional maneuvers. In the first chapter we present the literature review as well as the mathematical formulation using thrust vectoring approach to achieve forward and turning maneuvers. In the second chapter, we used a robotic vessel with elongated fin propulsion to determine the thrust scaling and efficiency. Using precise force and swimming kinematics measurements with the robotic vessel, the thrust generated by the undulating fin was found to scale with the square of the relative velocity between the free streaming flow and the wave speed. In addition, a hydrodynamic efficiency is presented based on propulsive force measurements and a model on the power required to oscillate the fin laterally.

On average, the American university president is a white man in his early 60s. Progress has been slow for women in this role. This study examined the university presidency with a focus on the woman president experience. The hypothesis was that based on factors such as the glass ceiling and glass cliff, gender affects the experiences of women university presidents. The purpose of this study was to understand the personal and professional meaning-making of breaking through the glass ceiling for women who have held or currently hold the position of president in higher education. The research methodology selected for this study was qualitative with a phenomenological design. There were two guiding research questions, which serve to understand the essence of the experiences of women who serve or have served in the role of president in higher education. The research questions are (a) how do women perceive the impact of the glass ceiling and/or the glass cliff on negotiating the role of university president from ascension to attainment? and (b) how do women university presidents perceive the price they have paid, personally and professionally, for breaking through the glass ceiling? The study sample size consisted of seven current or former women university presidents. The data collection method was semi-structured interviews. This study served to provide insight that may help identify support systems for women in the workplace, changes in perceptions of women in leadership, and how gender roles unfold in both the personal and professional lives of women university presidents

This study intended to examine factors potentially contributing to teacher retention and attrition at the local (district) level and the costs associated with this teacher movement. A secondary data set from a large urban school district in the southern United States served as the unit of analysis for this study. Demographic data on 25,724 teachers, from 2010-2019 were used in the analysis. A correlation, multiple regression, chi-square, and a demographic frequency distribution were run for each of the three criterion variables: teacher job attrition, teacher school attrition, and teacher retention. The predictor variables used in the analysis were gender, certification, total number of years teaching, and race/ethnicity. Student demographic data from the district were used as a comparison to teacher data from the same school district. Results indicated trends particular in teacher movement, whether job or school, impact the number of years a teacher stays in teaching. Special education certified teachers appear to be the most vulnerable to teacher movement. Teacher retention (leaving) averages over 17% each year over 10 years, costing $36 million dollars annually or over $367 million dollars over 10 years. At that rate, this district could experience a complete turnover of staff in only 5.7 years. Latino teachers are underrepresented in this teacher population and are out of proportion with the majority Latino student population. Black teachers change jobs and schools at statistically significantly higher rates than their White or Latino peers. National data are not longitudinal, and do not track teacher job movement, only teacher school movement. Current local data are critical for educational agencies, administrators, and decision makers to combat the teacher shortage. Findings from this study may inform the field about factors, trends, or patterns that contribute to teacher retention and attrition.

With the rapid development of networking platforms and data intensive applications, networks (or graphs) are becoming convenient and fundamental tools to model the complex inter-dependence among big scale data. As a result, networks (or graphs) are being widely used in many applications, including citation networks [40], social media networks [71], and so on. However, the high complexity (containing many important information) as well as the dynamic nature of the network makes the graph learning task more difficult. To have better graph representations (capture both node content and graph structure), many research efforts have been made to develop reliable and efficient algorithms. Therefore, the good graph representation learning is the key factor in performing well on downstream tasks. The dissertation mainly focuses on the graph representation learning, which aims to embed both structure and node content information of graphs into a compact and low dimensional space for a new representation learning. More specifically, in order to achieve an efficient and robust graph representation, the following four problems will be studied from different perspectives: 1) We study the problem of positive unlabeled graph learning for network node classification, and present a new deep learning model as a solution; 2) We formulate a new open-world learning problem for graph data, and propose an uncertain node representation learning approach and sampling strategy to solve the problem; 3) For cross-domain graph learning, we present a novel unsupervised graph domain adaptation problem, and propose an effective graph convolutional network algorithm to solve it; 4) We consider a dynamic graph as a network with changing nodes and edges in temporal order and propose a temporal adaptive aggregation network (TAAN) for dynamic graph learning. Finally, the proposed models are verified and evaluated on various real-world datasets.

Enemy relationships play an important role in shaping identity, adjustment, and group cohesion. However, little is known about the causes of enemy relationships. The current study identified the role of individual and dyadic attributes in the formation of new mutual antipathies in primary and middle school children (N=372). Participants completed identical surveys at three time points during a single school year. Self-reports described children’s conduct problems and emotional problems. Peer nominations measured children’s popularity, academic achievement, athleticism, and acceptance. The results indicated that enemy formation was driven by undesirable traits at both the individual and dyadic levels. At the individual level, lower academic achievement and higher conduct problems increased the odds of enemy formation. At the dyadic level, similarities between peers on conduct problems and emotional problems increased the odds of enemy formation. The findings, together with previous studies on the consequences of participation in enemy relationships, suggest that problems from enemy relationships contribute to the formation of new enemy relationships.

The structure and transparency of the eye lens are vital for focusing light onto the retina for vision. Lens fiber cells undergo a cellular remodeling program that removes mitochondria (MT), endoplasmic reticulum (ER), and Golgi apparatus (GA) to form mature transparent lens fiber cells. Previous studies established a requirement for the mitochondrial outer membrane protein BNIP3L for the elimination of these non-nuclear organelles in the lens; however, the precise molecular pathways for BNIP3L function remain to be elucidated. BNIP3L contains multiple functional domains whose analysis may illuminate its lens mechanisms including the LIR, BH3, and TM domains. These domains each play an important role in regulation of autophagosome formation and initiation of autophagy. To test each domain’s functionality for BNIP3L-dependent organelle elimination, we designed site-directed mutagenesis studies to delete each domain and test the resulting mutants in initiating the degradation of organelles in ex vivo cultured embryonic chick lenses.

Chapter 1: Background: The search for effective electric stimulation protocols for peripheral nerve regeneration, specifically in dorsal root ganglion (DRG), is an ongoing area of interest. Multiple stimulation parameters using direct current, alternating current and pulsed magnetic electric fields have proven to increase neurite regeneration. In the past, there has been limited exploration of the impact of action potential-like electrical stimulation on DRG regeneration. New method: A novel action potential-like electrical stimuli output from a custom-built action potential generator board was used to assess multiple stimulation parameters on DRG regeneration. Finite-element modeling was used to determine electrolyte potential across a non-uniform electric field to test the effects of electric field strength from action potential-like stimuli on DRG regeneration. Total neurite length and neurite branching per DRG were examined for each applied field strength and frequency to determine the effects of action potential-like stimulation on DRG structural regeneration. Results: Action potential-like stimulation showed inhomogeneous distribution of neurite regeneration and branching with higher regeneration and branching seen in areas away from the electrodes compared to the nearly homogenous distribution seen from the controls. Whole well analysis showed significant increases in total neurite regeneration and branching across all stimulation conditions with electric field strength, particularly 40 V/m, having the strongest effect on DRG structural regeneration. Comparison with existing methods: This study provides preliminary evidence supporting the hypothesis that action potential-like electric fields can improve DRG regeneration. Conclusions: This system and method may have applications for clinical interventions aimed at rehabilitating damaged peripheral nerve pathways.

This interdisciplinary dissertation examines Latinx political self-representation across a variety of narrative forms including fiction, nonfiction, film, and social media. Beginning with identifying points of political intersection and divergence within the imagined Latinx voting bloc incorrectly homogenized in mainstream discourse, the dissertation looks at how narrative empathy and political concerns for a singular issue– the child migrant crisis–play out differently across fiction and nonfiction written narratives. The dissertation then takes a turn towards exploring the lack of prominent Latinx political figures in the cultural imaginary, especially Latinas, by looking back to Latin America for exemplary models, and presenting community organizing as seen in recent filmic representation as an alternative form of political engagement. Finally, it focuses on two Latinx political figures–Oscar Zeta Acosta and Alexandria Ocasio-Cortez–who rose to notoriety half a century apart, yet took similar community insider/political outsider approaches to their historic runs for office. Overall, the dissertation stresses the importance of self-representation as a means of creating and controlling narrative empathy, as well as countering a mainstream narrative of a monolithic Latinx bloc that is both politically unengaged and threatening.

When practiced over long periods of time (>16 weeks), mindfulness positively impacts inhibitory processing, in that as mindfulness exposure and experience increases, inhibitory processing is enhanced. Similarly, long-term mindfulness practice diminishes the impact of emotionally-valanced scenes. However recently, more work is underway on how brief mindfulness inductions impact these same outcomes. Across two online pilot studies (behavioral outcomes only) and one in-person experiment (behavioral and neuronal outcomes), how a brief focused-breathing induction impacts response inhibition and the perception of affective words was explored. Findings demonstrate that a 30-minute mindfulness induction produced a diminished Simon Effect, as well as faster processing of neutral and positive words (faster LPP latencies) and less-effortful processing of negative words (reduced LPP amplitudes). How brief mindfulness inductions may impact resting frontal alpha asymmetry were also explored.