UTSA Runner Research Press (Univ. of Texas at San Antonio)
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Analysis of the Skin and Brain Transcriptome of Normally Pigmented and Pseudo-Albino Southern Flounder (Paralichthys lethostigma) Juveniles to Study the Molecular Mechanisms of Hypopigmentation and Its Implications for Species Survival in the Natural Environment
No full textSouthern flounder skin pigmentation is a critical phenotypic characteristic for this species’ survival in the natural environment. Normal pigmentation allows rapid changes of color for concealment to capture prey and UV light protection. In contrast, highly visible hypopigmented pseudo-albinos exhibit a compromised immune system and are vulnerable to predation, sensitive to UV exposure, and likely have poor survival in the wild. Skin and brain tissue samples from normally pigmented and hypopigmented individuals were analyzed with next-generation RNA sequencing. A total of 1,589,613 transcripts were used to identify 952,825 genes to assemble a de novo transcriptome, with 99.43% of genes mapped to the assembly. Differential gene expression and gene enrichment analysis of contrasting tissues and phenotypes revealed that pseudo-albino individuals appeared more susceptible to environmental stress, UV light exposure, hypoxia, and osmotic stress. The pseudo-albinos’ restricted immune response showed upregulated genes linked to cancer development, signaling and response, skin tissue formation, regeneration, and healing. The data indicate that a modified skin collagen structure likely affects melanocyte differentiation and distribution, generating the pseudo-albino phenotype. In addition, the comparison of the brain transcriptome revealed changes in myelination and melanocyte stem cell activity, which may indicate modified brain function, reduced melanocyte migration, and impaired vision.Genomic Core Facilit
Adventures in Catalysis: Development of Transition Metal-Catalyzed Reactions for C-X Bond Formations and High-Resolution Mass Spectrometry Tools for Probing Catalytic Reaction Mechanisms
No full textThe dissertation contained herein will chronical the development of new Pd- and Ni-catalyzed C-X bond forming reactions and the initial development of a new direct-injection high-resolution mass spectrometry (DI-HRMS) tool for detecting organometallic complexes in cross-coupling reactions at synthetically relevant concentrations.
Chapter 2 focuses on the development of a Pd-catalyzed, chemoselective O-selective benzylation of 2-quinolinones and 2-pyridones. These classes of N,O-heterocycles are deemed ambident nucleophiles, i.e. they have 2 nucleophilic sites on the same molecule. Though N-alkylation is well established, selective O-alkylation has been largely dependent on the use of stoichiometric Ag salts. In collaboration with the Chemical Process Development team at Bristol Myers Squibb (BMS), we have developed a novel Pd-catalyzed system capable of selectively alkylating the oxygen atom of 2-quinolinone using benzyl bromides as the electrophilic partner. Mechanistic experiments identified a surprising Xantphos mono-oxide Pd(II) η<sup>1</sup>-benzyl complex as the resting state of our catalyst and responsible for such high chemoselectivity. Expansion of this chemistry to 2-pyridone, a related heterocycle, has proven a much larger task than initially thought. Through optimization, new biphasic reaction conditions have been identified as a promising alternative to achieve a similar chemoselectivity as was observed with 2-quinolinones. Further mechanistic experiments have begun to probe the C-O bond forming step.
Chapter 3 stemmed from a curiosity from the work in Chapter 1. The Xantphos mono-oxide Pd(II) η<sup>1</sup>-benzyl complex was first identified through DI-HRMS. Without this piece of data, the discovery of this intermediate would have been greatly hindered. Given the capabilities of high-resolution mass spectrometers to detect compounds even at low concentrations, we set out to explore other canonical Pd-catalyzed cross-coupling reactions in a similar manner. So far we have explored both Sonogashira reactions and C-O coupling reactions. We have successfully detected multiple on-cycle complexes as well as some surprising off-cycle species. Current works are focused on exploring several protocols for Heck reactions and Buchwald-Hartwig aminations so explore the effects of different conditions on the detectable species.
Chapter 4 follows a second collaboration with the Chemical Process Development team at Bristol Myers Squibb. Though Ni-catalyzed C-N coupling has been studied for decades, their applicability to a broad range of substrate classes and large scale reactions has left much to be desired. Using the power of HTE at BMS, we set out to establish a Ni catalyst to unify the reactivity and substrate scopes of previous incarnations while making dramatic improvements to functional group tolerability and scalability. Herein, we have demonstrated a Ni-catalyzed system capable of the C-N coupling of aryl chlorides with anilines and aliphatic amines under markedly milder conditions to those previously reported. We have demonstrated the unique reactivity of our Ni-catalyzed system and are currently pursuing expanding the electrophile scope.Chemistr
Perceived Competency in Animal-Assisted Therapy in Counseling: An Instrument Validation Study
No full textThis study aimed to validate a tool for assessing self-perceived competence in animal-assisted therapy in counseling (AAC) among counselors. A literature review uncovered a gap in understanding counselors competencies in AAC. While various training programs exist, they often lack counseling-specific knowledge. The American Counseling Association (ACA) offers competency guidelines for AAC but does not mandate formal training (Stewart et al., 2016). This absence of standardized training raises concerns about potential misuse and harm. Using a Delphi research design, the researcher surveyed experts to identify essential knowledge, skills, attitudes, and beliefs for competency in AAC. Experts emphasized the significance of counselors possessing a comprehensive understanding of animal behavior, ethical considerations in AAC practice, and the role of the human-animal bond in therapeutic interventions. Additionally, key skills such as effective communication with therapy animals, risk management strategies, and the ability to adapt interventions based on client needs emerged as fundamental competencies. Furthermore, experts highlighted the importance of cultivating attitudes of empathy, flexibility, and cultural sensitivity to effectively navigate diverse client populations in AAC settings. These findings underscore the need for counselor training programs to integrate AAC competencies into their curricula and for ongoing professional development opportunities to support counselors in enhancing their AAC practice. Findings have implications for counselor education, clinical practice, and future research. Recommendations include integrating AAC competencies into curricula and establishing guidelines for ethical and safe implementation. Continued professional development is essential to ensure counselor competence in AAC.Counselin
Exploring the Economic Value of Decentralization on Tokenized Digital Platforms
No full textTokenized digital platforms are emerging as a burgeoning field, driven by their transformative potential towards decentralization across various market sectors. However, the market impact of decentralization remains obscure. This dissertation investigates how the economic value of decentralization unfolds through the interplays of decentralized financing, governance, and token incentives. Drawing on mechanism design theory and institutional analysis and development framework, this study identifies a value chain of decentralization through decision-making (DM) power distribution, participation in DM processes, and DM network structures. My empirical findings show that a greater DM power decentralization leads to more equitable user participation in voting and contribution, shifting user focus towards participation versus trading. This shift mitigates the dual-value dilemma associated with tokenization on these platforms. Moreover, well-aligned participation contributes to overlapping and cohesive network structures, boosting contribution volume but at the cost of variety. While the overlapping structure induced by users’ role spanning behaviors promotes user growth, an optimally cohesive network is crucial for maximizing this growth. Additional analyses also reveal a minimum threshold for decentralized governance to garner positive influence in this value chain. These findings illustrate how decentralized governance incentivizes user participation, which leads to effective DM network structures that benefit platform growth under tokenized financing structure. By mapping the value chain of decentralization on tokenized platforms, this dissertation fills both the theoretical and empirical gaps in tokenized platform literature and lays the groundwork for future research into tokenomics that steers us towards a globalized digital economy.Information Systems and Cyber Securit
SSL4EO-L: Datasets and Foundation Models for Landsat Imagery
No full textLandsat: Science, Petabytes, and SSL:
[Figure]
• Landsat's scientific significance and extended coverage
• Petabytes of accessible Landsat imagery
• Challenge: diverse sensors, varied wavelengths, and the lack of pre-trained models
• Problem: scarcity of large labeled datasets
• Solution: self-supervised learning (SSL)Electrical and Computer Engineerin
Empowering Tomorrow through Student Engagement in Generative AI
No full textSlide deck for in-person presentation at the 2024 GenerationAI Summit at the University of Texas at San Antonio.Academic Innovatio
Modeling Emission of Jet/Accretion Flow/Black Hole (JAB) Systems in GRMHD
No full textIntroduction:
• Modeling emission in jet/accretion flow/black hole (JAB) systems is a crucial part of understanding the dynamics behind active galactic nuclei.
• An established emission model emulating turbulent heating, the R-β Model, expresses the ion-to-electron temperature R as a function of plasma beta.
• Our alternative Critical β Model has an exponential transition from preferential electron to proton heating as a function of β; Our inclusion of magnetic-to-particle energy reconnection based emission in jet regions for both turbulent heating models are key advances in JAB emission model accuracy.
• We look at two distinct flow states for the accreting plasma: standard and normal evolution (SANE) and magnetically arrested disk (MAD).
• We model two large, well-studied Event Horizon Telescope (EHT) targets (M87 and Sgr A*), to create a pattern of emission properties and compare with observational evidence.Physics and Astronom
Demystifying the Privacy-Realism Dilemma in the Metaverse
No full textOpen-source software (OSS) often needs to be built by roles who are not contributors. Despite the prevalence of build issues experienced by non-contributors, there is a lack of studies on this topic. This paper presents a study aimed at understanding the symptoms and causes of build issues experienced by non-contributors. The findings highlight certain build issues that are challenging to resolve and underscore the importance of understanding non-contributors' behavior. This work lays the foundation for further research aimed at enhancing the non-contributors' experience in dealing with build issues.Computer Scienc
The Logic of Horror
Get PDFThis thesis explores the philosophical and metaphysical nature of fictional objects, particularly in the context of horror fiction. Examining the intersection of existence, essentialism, and fiction. Drawing on and critiquing the works of Bertrand Russell, Alexius Meinong, and W.V.O. Quine, the thesis argues for a refined version of Modal Meinongianism (MM) as the most coherent framework for understanding fictional entities. It posits that fictional objects have being in all possible worlds and exist in some, rejecting the unrestricted comprehension principle (UCP) in favor of a qualified comprehension principle (QCP) to exclude impossible objects. The thesis examines how fictional entities are discovered rather than created, emphasizing their preexistence in alternate possible worlds. By analyzing transformations in fiction, such as Gregor Samsa in The Metamorphosis or Pennywise in IT, the work challenges rigid modal logics like S5, advocating for weaker systems like K?? that allow for the gain, loss, and exchange of essential properties. It also explores relative and absolute possibility, demonstrating how fictional objects inhabit isolated subspaces of possible worlds and acquire varying properties across different realities. Through an interdisciplinary approach combining modal logic, metaphysics, and literary analysis, this thesis defends the ontological significance of fictional objects and their profound impact on human thought, emotion, and culture. Ultimately, it contends that fictional entities play a critical role in our philosophical understanding of existence and possibility, bridging the gap between imagination and metaphysical reality.Philosoph