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Molecular Mechanisms of Mental Illness: Quantum Dot-based Single Molecule Investigation of the Dopamine Transporter and Its Protein Partners
No full textThe human dopamine transporter (DAT) is a presynaptic transmembrane protein that facilitates the reuptake of synaptically released dopamine. Several lines of evidence indicate that DAT dysfunction is linked to neuropsychiatric disorders, such as autism spectrum disorder (ASD), bipolar disorder (BD), and attention deficit hyperactivity disorder. The lateral membrane diffusion and clustering propensity of DAT are emergent properties of functional dopamine signaling. This thesis work will be focused on interrogating DAT membrane diffusion dynamics utilizing a suite of independent labeling strategies. Using fluorescence microscopy, single particle tracking (SPT) of ASD/BD-associated DAT missense mutant A559V will be carried out by labeling them with antagonist-conjugated quantum dots (Qdots). The effects of the D2 dopamine receptor (D2R) modulation on aberrant DAT A559V diffusion will be investigated, including functional D2R antagonism and simultaneous tracking of both DAT and D2R. In addition, the propensity and extent of DAT and DAT A559V colocalization with D2R into membrane microdomains will be evaluated using a multiplexed Qdot-SPT strategy. While heterologous expression systems prove to be valid platforms in neuroscience, translating SPT studies to a native 3D neuronal architecture will be necessary for application in diagnosis and therapy for mental disease. To assess the degree to which DAT and its variants diffuse and cluster in vivo, our group has developed a novel antagonist-conjugated Qdot-SPT strategy that capitalizes on a Qdot design that yields exceptional photophysical properties and access to sterically hindered spaces in deep tissue to track native DAT in physiologically relevant environments such as brain tissue slices. This thesis work will be focused on probe optimization to reduce non-specific binding to maximize DAT membrane tracking confidence
Factors Correlating With Initial Implementation of Tangible Symbols for Students With Visual Impairments
No full textTangible symbols are an augmentative and alternative communication (AAC) option that can be used to facilitate the communication of students who have visual impairments (VI) and complex communication needs. Sixty-three professionals completed this survey who worked in the role of teacher of students with visual impairments (TVI), speech-language pathologist (SLP), or severe disabilities special education teacher and had recently participated in the selection of tangible symbols for a student with VI and complex communication needs. Participants were asked about demographic information, the tangible symbol selection process, and the extent of planned initial implementation of the tangible symbols within the first month after selection. Pearson correlations were calculated between several student and professional variables and the initial implementation variables. Statistically significant positive correlations were found between the initial implementation of tangible symbols and collaboration, student communication levels, and student grade level. A statistically significant negative correlation was found between initial implementation and participant reports of being the primary team member to determine a student’s need for tangible symbols. Qualitative data from participants’ write-in responses highlighted aspects of collaboration that participants deemed important to the tangible symbol selection process, and demonstrated that there was much participants wished they had known earlier in their careers about making decisions regarding tangible symbols for their students
Large Scale Semantic Trajectory Analysis and Applications
No full textThe rapid growth of mobile devices and location-based services has led to an explosion of semantic trajectory data, creating significant challenges in efficient analysis and practical applications. Traditional methods often face limitations in computation, scalability, and privacy, especially when handling large datasets of semantic trajectories.
This dissertation addresses these issues with three major contributions. First, it introduces AnotherMe, a distributed algorithm that uses Sequence-Sensitive Hashing (SSH) for efficient semantic grouping and similarity calculation, achieving significant improvements in processing speed and scalability. Second, it proposes GRU-KSS, a two-branch deep learning model that delivers real-time, accurate social community recommendations by analyzing semantic trajectories. Third, it develops a privacy preserving framework that utilizes semantic trajectories for travel buddy recommendations, combining a multi-server design with a privacy-preserving index tree to protect user data.
Comprehensive experiments confirm the effectiveness of these methods, demonstrating superior scalability, accuracy, and privacy compared to existing approaches. These contributions highlight the potential of semantic trajectory analysis to drive advancements in intelligent, privacy-focused recommendation systems
"But We Have this Treasure in Clay Jars:" Interpreting the Pauline Paradox in the Postcolonial Context of Corinth
No full textScholarly research on 2 Corinthians 4 emphasizes the abiding faith, hope, strength, and courage to be found in the text, as Paul describes his attitude towards the salvific divine power of God in the face of struggles and afflictions. This project argues that by reading Corinth as a postcolonial context the text shows the debilitating presence of imperial power over the subjects and objects within it.
Just as colonial power remains both visible and invisible in the formation and the maintenance of the Nigerian state, so does the Roman imperial power remain a present and shadowed entity in the reading of 2 Corinthians 4. Therefore, my project asks, “How do different groups in Corinth, and in contemporary postcolonial contexts navigate agency, belonging, subjectivity, and hierarchical relationships within complex systems of collective resource distribution and identity formation?”
I discuss how Paul's encouragement and inspiration for faith and practice among the Corinthians is divided between sustaining hope and reapplying existing imperial methods of organization which allow for the survival of those within the empire. The paradoxes these ambivalent reactions construct are at once liberating and revitalizing as well as constricting and exclusive. For the many within the context of Corinth and in contemporary times, it becomes apparent that sustaining life is dependent on substantial contributions towards obtaining power, authority, and legitimacy.
I employ African biblical hermeneutics, postcolonial feminism, rhetorical and materialist criticism as intersecting methods of interpretation. These emphasize the imperial and textual context of the reading of 2 Corinthians 4, in addition to the socioeconomic experiences of those within the text and those within the Nigerian context.
I conclude that this project has insightful implications for future studies as it may help to inform the ethical stance of interpreters against socioeconomic and political policies which sustain, displace, and deny the full humanity of the disowned, the poor, the displaced, and the exploited
Advanced Research on Fiber and Powder Electrodes for Fuel Cells and Redox Flow Batteries
No full textWhen fuel cell electrodes are prepared by coating or spraying a mixture of catalyst particles and polymer binder, there is little or no control of the multi-scale electrode morphology. Electrode structural features such as particle and binder interconnectivity, macro-porosity, and micro-porosity are difficult to control but are critically important when high-performance nanocatalysts are used. Nanofiber electrospinning is an electrode fabrication technique that can address these issues for next-generation high-performance fuel cells. Conventional powder catalyst fuel cell electrodes also suffer from poor durability (carbon corrosion and metal dissolution) which limits their operational lifetime. The use of chemical additives has shown some promise, but an improvement in electrode lifetime was usually accompanied by a loss in fuel cell power output. The use of fluoropolymer binders in fuel cells is also problematic, given the recent healthcare concerns regarding fluorinated “forever compounds.”
This dissertation seeks to address deficiencies in nanofiber electrodes and sprayed powder electrodes for H2/air proton exchange membrane fuel cells, and H2/Br2 redox flow batteries. For sprayed powder electrodes, a hydrophobic additive was found that stopped carbon corrosion of a Pt/C catalyst cathode without sacrificing fuel cell power output, and a new hydrocarbon electrode binder was investigated which worked very well in a fuel cell cathode when mixed with a water-soluble pore former. To improve the compatibility of nanofiber electrospinning with commercial roll-to-roll fuel cell electrode manufacturing lines, a new fabrication method was developed where electrodes were prepared by spraying inks containing pre-formed electrospun fibers. Fiber electrodes were also used for the hydrogen electrode in a H2/Br2 redox flow battery, where a hydrophobic coating on the fibers prevented Pt dissolution by bromine species.
In this talk, for each electrode system, the method for preparing the electrodes will be presented, experiments to evaluate the electrodes will be described, and experimental results will be discussed
Introduction to Clinical Psychology Textbooks: What’s Missing?
No full textTextbooks are fundamental to higher education. Scholars have previously evaluated texts from a wide range of disciplines. However, similar analyses have yet to assess Introduction to Clinical Psychology (ICP) textbooks. This study examined 15 ICP textbooks, scanning for content on Intellectual and Developmental Disabilities (IDDs), with a secondary focus on the Eugenics movement. A 0-5 scale, with labels of “no rating, scant, brief, adequate, substantial, and extensive” was employed to code results. The results indicate that the mode values for general coverage of Developmental Disabilities, the Eugenics movement, as well as Intellectual Disabilities for children and adults were zero, or “no rating.” The mean ratings for each general category fell between “no rating” and “scant.” Frequency counts of specific IDDs were also investigated, with Autism Spectrum Disorder (ASD) being, on average, the most prevalent. This study could be a catalyst for further analyses of ICP textbooks, and reflection about the content that psychological pedagogy prioritizes going forward.
Keywords: Intellectual and Developmental Disabilities, EugenicsThesis completed in partial fulfillment of the requirements of the Honors Program in Psychological Science
The Politics of Military Deployments
No full textHow do domestic politics shape decisions to deploy U.S. service members worldwide? This dissertation seeks to explain where America's sons and daughters go, and why. It endeavors to understand the relative influence of domestic political factors--both behavioral and institutional--that drive military presence abroad. How group identity, the public, and elites shape deployment decisions has implications for the conduct of U.S. leadership in world affairs--and the peace or war that follows. Chapter 2 describes three primary gaps in American deployment attitudes. Its key finding is that White House officials and members of Congress and their staffers are considerably more interventionist than the people they represent. Chapter 3 focuses on group identity and its shaping of deployment attitudes. Using Chicago Council on Global Affairs public opinion data on long-term basing overseas, it offers an explanation for a proximal military community effect that favors U.S. primacy for closer survey respondents, even if they do not serve or are related to someone who does. Chapter 4 explores the link between public attitudes and foreign policy decisions. It predicts and finds a null relationship between mass opinion on deployments to countries and the adjoining troop levels in those countries. Finally, Chapter 5 evaluates the political conditions under which commanders-in-chief intervene in military policymaking on deployments. An analysis of troops deployed or stationed abroad by country from 1952 to 2022 shows that divided government changes party preferences for deployments and weighs on a president's willingness to accept or ignore Department of Defense advice. A ruling party, its power across government, and its stake in defense policy ownership influence precise troop levels--with notable implications for the consistency and predictability of American foreign policy
Enhancing Recruitment for the Baton Rouge Police Department
No full textLeadership and Learning in Organizations capstone projectThe Baton Rouge Police Department (BRPD), like most police departments across the United States, is struggling to recruit new officers. This study examines the ongoing challenges within the BRPD as it develops strategies to transform recruitment, focusing on the department’s difficulties in attracting, recruiting, and retaining recruits. These challenges stem from a shrinking applicant pool, a lengthy onboarding process, and shifting public perceptions of law enforcement. Using a mixed-methods approach, we distributed a climate study, reviewed existing institutional data, conducted qualitative interviews, and administered questionnaires to answer the project’s central question: What internal strategies can the BRPD leverage to effectively transform recruitment? Based on our findings, we recommend enhancing community engagement, empowering current officers as recruiters, streamlining early recruitment stages, and integrating civilian roles to build a more sustainable and resilient recruitment strategy
Intra- and Inter-cellular Signals Regulate Human Islet Cell Function in Health and Diabetes
No full textPancreatic islet dysfunction is central to all forms of diabetes; however, the mechanisms of pancreatic islet dysfunction in diabetes are not well understood. Hormone secretion from endocrine cells within the islet is tightly regulated by gene regulatory networks that maintain cell identity and function. Additionally, endocrine cells integrate multiple extrinsic signals from other cells within the islet to tune hormone secretion. The primary goal of this Dissertation was to advance our understanding of how adult human islet cell function is regulated and how alterations in these regulatory mechanisms contribute to islet dysfunction. To accomplish this, I took a multi-pronged approach that included a statistical analysis of hormone secretion by normal human islets, manipulation of human islet cell gene expression, and alteration of islet composition to understand how β and α cell-intrinsic and cell-extrinsic signals regulate cell function. In the first study, we found that insulin and glucagon secretion by human islets isolated from 299 organ donors without diabetes was highly heterogeneous and predicted by multiple donor traits, most notably islet cell composition, which was associated with donor sex, genetic ancestry, and genetic risk for type 2 diabetes. In our second study, we explored regulation at the intracellular level, where we investigated the role of the islet-enriched transcription factor NKX2.2, which is known to have both repressor and activator functions. We found that, distinct from findings in mice, NKX2.2 is expressed in all three major endocrine cell types in human, including δ cells; further, NKX2.2 was highly co-expressed with other important islet-enriched transcription factors throughout the human lifespan, suggesting an important role in coordinating gene regulatory networks. Surprisingly, reduced expression of NKX2.2 in human islet cells leads to increased hormone secretion by β cells but not α cells, indicating a cell type-specific function. Finally, we investigated the role of altered regulation in the α cell dysfunction seen in type 1 diabetes. We found that, in the absence of β cells, α cells have greater glucagon secretion, while repeated exposure to low glucose leads to impaired glucagon secretion. Overall, the studies presented in this Dissertation highlight the complex nature of coordinated human islet function and have implications for diabetes pathophysiology and treatment
Simplified and Low-Cost CT Scanner for Medical Imaging Education
No full textCollege of Arts and ScienceDepartment of Physics and Astronom